WorldWideScience

Sample records for field experiment determinations

  1. Determination of Biology Department Students' Past Field Trip Experiences and Examination of Their Self-Efficacy Beliefs in Planning and Organising Educational Field Trips

    Science.gov (United States)

    Bozdogan, Aykut Emre

    2015-01-01

    The purpose of this study is to determine the past field trip experiences of pre-service teachers who are graduates of Faculty of Sciences, Department of Biology and who had pedagogical formation training certificate and to examine their self-efficacy beliefs in planning and organizing field trips with regard to different variables. The study was…

  2. Nuclide-migration field experiments

    International Nuclear Information System (INIS)

    Erdal, B.R.; Wolfsberg, K.; Johnstone, J.K.; Erickson, K.L.; Friedman, A.M.; Fried, S.; Hines, J.J.

    1981-03-01

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions

  3. Nuclide-migration field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Erdal, B.R.; Wolfsberg, K.; Johnstone, J.K.; Erickson, K.L.; Friedman, A.M.; Fried, S.; Hines, J.J.

    1981-03-01

    When considering groundwater flow and radionuclide retention in the complex flow systems that can occur in geologic formations, one has a serious problem in determining if laboratory studies are being performed under conditions appropriate to natural systems. This document is the project plan for a program designed to begin to address these problems. The project is being carried out jointly by the Los Alamos National Laboratory, Sandia National Laboratories, and Argonne National Laboratory. The work has three principal objectives: (1) to develop the experimental, instrumental, and safety techniques necessary to conduct controlled, small-scale radionuclide migration field experiments, including those involving actinides; (2) to use these techniques to define radionuclide migration through rock by performing generic, at-depth experiments under closely monitored conditions; and (3) to determine whether available lithologic, geochemical, and hydrologic properties together with existing or developing transport models are sufficient and appropriate to describe real field conditions.

  4. Females and STEM: Determining the K-12 Experiences that Influenced Women to Pursue STEM Fields

    Science.gov (United States)

    Petersen, Anne Marie

    In the United States, careers in the fields of Science, Technology, Engineering, and Mathematics (STEM) are increasing yet there are not enough trained personnel to meet this demand. In addition, of those that seek to pursue STEM fields in the United States, only 26% are female. In order to increase the number of women seeking STEM based bachelor's degrees, K-12 education must provide a foundation that prepares students for entry into these fields. The purpose of this phenomenological study was to determine the perceived K-12 experiences that influenced females to pursue a STEM field. Twelve college juniors or seniors seeking a degree in Biology, Mathematics, or Physics were interviewed concerning their K-12 experiences. These interviews were analyzed and six themes emerged. Teacher passion and classroom characteristics such as incorporating challenging activities played a significant role in the females' decisions to enter STEM fields. Extra-curricular activities such as volunteer and mentor opportunities and the females' need to benefit others also influenced females in their career choice. Both the formal (within the school) and informal (outside of the traditional classroom) pipeline opportunities that these students encountered helped develop a sense of self-efficacy in science and mathematics; this self-efficacy enabled them to persist in pursuing these career fields. Several participants cited barriers that they encountered in K-12 education, but these barriers were primarily internal as they struggled with overcoming self-imposed obstacles in learning and being competitive in the mathematics and science classrooms. The experiences from these female students can be used by K-12 educators to prepare and encourage current female students to enter STEM occupations.

  5. Grimsel Test Site: modelling radionuclide migration field experiments

    International Nuclear Information System (INIS)

    Heer, W.; Hadermann, J.

    1994-09-01

    In the migration field experiments at Nagra's Grimsel Test Site, the processes of nuclide transport through a well defined fractured shear-zone in crystalline rock are being investigated. For these experiments, model calculations have been performed to obtain indications on validity and limitation of the model applied and the data deduced under field conditions. The model consists of a hydrological part, where the dipole flow fields of the experiments are determined, and a nuclide transport part, where the flow field driven nuclide propagation through the shear-zone is calculated. In addition to the description of the model, analytical expressions are given to guide the interpretation of experimental results. From the analysis of experimental breakthrough curves for conservative uranine, weakly sorbing sodium and more stronger sorbing strontium tracers, the following main results can be derived: i) The model is able to represent the breakthrough curves of the migration field experiments to a high degree of accuracy, ii) The process of matrix diffusion is manifest through the tails of the breakthrough curves decreasing with time as t -3/2 and through the special shape of the tail ends, both confirmed by the experiments, iii) For nuclide sorbing rapidly, not too strongly, linearly, and exhibiting a reversible cation exchange process on fault gouge, the laboratory sorption coefficient can reasonably well be extrapolated to field conditions. Adequate care in selecting and preparing the rock samples is, of course, a necessary requirement. Using the parameters determined in the previous analysis, predictions are made for experiments in a smaller an faster flow field. For conservative uranine and weakly sorbing sodium, the agreement of predicted and measured breakthrough curves is good, for the more stronger sorbing strontium reasonable, confirming that the model describes the main nuclide transport processes adequately. (author) figs., tabs., 29 refs

  6. Viking satellite program - preliminary results from the APL Magnetic Field Experiment

    International Nuclear Information System (INIS)

    Potemra, T.A.; Zanetti, L.J.; Erlandson, R.E.; Gustafsson, G.; Acuna, M.H.; NASA, Goddard Space Flight Center, Greenbelt, MD)

    1986-01-01

    Sweden's Viking satellite, launched in February 1986, has been conducting plasma process observations in the earth magnetosphere and auroral regions; the U.S.-supplied APL Magnetic Field Experiment aboard Viking is used to determine field-aligned Birkeland current characteristics in previously unsampled regions of near-earth space. The Magnetic Field Experiment has an equivalent spatial resolution of 12 m in the auroral ionosphere when making measurements near apogee. The purposes of Viking's other instruments and their relationship to the Magnetic Field Experiment are discussed

  7. Influencing attitudes toward science through field experiences in biology

    Science.gov (United States)

    Carpenter, Deborah Mcintyre

    The purpose of this study was to determine how student attitudes toward science are influenced by field experiences in undergraduate biology courses. The study was conducted using two institutions of higher education including a 2-year lower-level and a 2-year upper-level institution. Data were collected through interviews with student participants, focus group discussions, students' journal entries, and field notes recorded by the researcher during the field activities. Photographs and video recordings were also used as documentation sources. Data were collected over a period of 34 weeks. Themes that emerged from the qualitative data included students' beliefs that field experiences (a) positively influence student motivation to learn, (b) increase student ability to learn the concepts being taught, and (c) provide opportunities for building relationships and for personal growth. The findings of the study reinforce the importance of offering field-study programs at the undergraduate level to allow undergraduate students the opportunity to experience science activities in a field setting. The research study was framed by the behavioral and developmental theories of attitude and experience including the Theory of Planned Behavior (Ajzen, 1991) and the Theory of Experiential Learning (Kolb, 1984).

  8. 1. Introduction. 2. Laboratory experiments. 3. Field experiments. 4. Integrated field-laboratory experiments. 5. Panel recommendations

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Some recommendations for the design of laboratory and field studies in marine radioecology are formulated. The difficulties concerning the comparability of various experimental methods used to measure the fluxes of radionuclides through marine organisms and ecosystems, and also the use of laboratory results to make predictions for the natural environment are discussed. Three working groups were established during the panel meeting, to consider laboratory experiments, field studies, and the design and execution of integrated laboratory and field studies respectively. A number of supporting papers dealing with marine radioecological experiments were presented

  9. Field-scale colloid migration experiments in a granite fracture

    International Nuclear Information System (INIS)

    Vilks, P.; Frost, L.H.; Bachinski, D.B.

    1997-01-01

    An understanding of particle migration in fractured rock, required to assess the potential for colloid-facilitated transport of radionuclides, can best be evaluated when the results of laboratory experiments are demonstrated in the field. Field-scale migration experiments with silica colloids were carried out at AECL's Underground Research Laboratory (URL), located in southern Manitoba, to develop the methodology for large-scale migration experiments and to determine whether colloid transport is possible over distances up to 17 m. In addition, these experiments were designed to evaluate the effects of flow rate and flow path geometry, and to determine whether colloid tracers could be used to provide additional information on subsurface transport to that provided by conservative tracers alone. The colloid migration studies were carried out as part of AECL's Transport Properties in Highly Fractured Rock Experiment, the objective of which was to develop and demonstrate methods for evaluating the solute transport characteristics of zones of highly fractured rock. The experiments were carried out within fracture zone 2 as two-well recirculating, two-well non-recirculating, and convergent flow tests, using injection rates of 5 and 101 min -1 . Silica colloids with a 20 nm size were used because they are potentially mobile due to their stability, small size and negative surface charge. The shapes of elution profiles for colloids and conservative tracers were similar, demonstrating that colloids can migrate over distances of 17 m. The local region of drawdown towards the URL shaft affected colloid migration and, to a lesser extent, conservative tracer migration within the flow field established by the two-well tracer tests. These results indicate that stable colloids, with sizes as small as 20 nm, have different migration properties from dissolved conservative tracers. (author)

  10. Crystalline Electric Field Levels in the Neodymium Monopnictides Determined by Neutron Spectroscopy

    DEFF Research Database (Denmark)

    Furrer, A.; Kjems, Jørgen; Vogt, O.

    1972-01-01

    Neutron inelastic scattering experiments have been carried out to determine the energies and widths of the crystalline electric field levels in the neodymium monopnictides NdP, NdAs, and NdSb. The energy level sequence is derived from the observed crystal field transition peak intensities, which...... are in good agreement with calculations based on elementary crystal field theory. The energy level widths are qualitatively discussed. It is found that the point-charge model cannot reproduce the crystal field levels satisfactorily....

  11. 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)

  12. Experiments for obtaining field influence mass particles.

    CERN Document Server

    Yahalomi, E

    2010-01-01

    Analyzing time dilation experiments the existence of a universal field interacting with moving mass particles is obtained. It is found that mass particle changes its properties depend on its velocity relative to this universal scalar field and not on its velocity relative to the laboratory. High energy proton momentum, energy and mass were calculated obtaining new results. Experiments in high energy accelerators are suggested as additional proofs for the existence of this universal field. This universal field may explain some results of other high energy experiments.

  13. Applicability of sorption data determined by laboratory experiments for evaluation of strontium-85 mobility in subsurface field

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Mukai, Masayuki

    2003-01-01

    Applicability of laboratory measurements to radionuclide transport in a natural environment was studied using the data from the field tests. The K d values obtained in the laboratory experiments were input into the instantaneous equilibrium sorption model, which simulates the migration of 85 Sr in the unsaturated loess. This simulation managed to reproduce results of the aforementioned field tests. To evaluate more accurately migration behavior of 85 Sr, based on the sorption data obtained by the laboratory experiments, the hybrid sorption model consisting of the equilibrium sorption process and the kinetic sorption process was proposed. When compared with predictions using the K d -based equilibrium sorption model, the results of the field migration tests of 85 Sr were more successfully reproduced by introducing the hybrid sorption model. (author)

  14. The National Airborne Field Experiment Data Sets

    DEFF Research Database (Denmark)

    Walker, J. P.; Balling, Jan E.; Bell, M.

    2007-01-01

    The National Airborne Field Experiment's (NAFE) were a series of intensive experiments recently conducted in different parts of Australia. These hydrologic-focused experiments have been designed to answer a range of questions which can only be resolved through carefully planned and executed field...

  15. Tandem mirror and field-reversed mirror experiments

    Energy Technology Data Exchange (ETDEWEB)

    Coensgen, F.H.; Simonen, T.C.; Turner, W.C.

    1979-08-21

    This paper is largely devoted to tandem mirror and field-reversed mirror experiments at the Lawrence Livermore Laboratory (LLL), and briefly summarizes results of experiments in which field-reversal has been achieved. In the tandem experiment, high-energy, high-density plasmas (nearly identical to 2XIIB plasmas) are located at each end of a solenoid where plasma ions are electrostatically confined by the high positive poentials arising in the end plug plasma. End plug ions are magnetically confined, and electrons are electrostatically confined by the overall positive potential of the system. The field-reversed mirror reactor consists of several small field-reversed mirror plasmas linked together for economic reasons. In the LLL Beta II experiment, generation of a field-reversed plasma ring will be investigated using a high-energy plasma gun with a transverse radial magnetic field. This plasma will be further heated and sustained by injection of intense, high-energy neutral beams.

  16. Field experiments in salt formations

    International Nuclear Information System (INIS)

    Kuehn, K.

    1986-01-01

    Field experiments in salt formations started as early as 1965 with Project Salt Vault in the Lyons Mine, Kansas, U.S.A., and with the purchase of the Asse salt mine by the German Federal Government. Underground tests concentrated on the heat dissipation around buried high-level radioactive wastes and the geomechanical consequences of their disposal. Near-field investigations cover the properties of water and gas release, radiolysis and corrosion. Further objectives of field experiments are the development and underground testing of a handling system for high-level wastes. The performance of an underground test disposal for such wastes is not only considered to be necessary for technical and scientific reasons but also for improving public acceptance of the concept of radioactive waste disposal. (author)

  17. A balloon-borne experiment to investigate the Martian magnetic field

    Science.gov (United States)

    Schwingenschuh, K.; Feldhofer, H.; Koren, W.; Jernej, I.; Stachel, M.; Riedler, W.; Slamanig, H.; Auster, H.-U.; Rustenbach, J.; Fornacon, H. K.; Schenk, H. J.; Hillenmaier, O.; Haerendel, G.; Yeroshenko, Ye.; Styashkin, V.; Zaroutzky, A.; Best, A.; Scholz, G.; Russell, C. T.; Means, J.; Pierce, D.; Luhmann, J. G.

    1996-03-01

    The Space Research Institute of the Austrian Academy, of Sciences (Graz, Austria) in cooperation with MPE (Berlin, Germany), GFZ Potsdam (Obs. Niemegk, Germany) IZMIRAN/IOFAN (Moscow, Russian) and IGPP/UCLA (Los Angeles, USA) is designing the magnetic field experiment MAGIBAL (MAGnetic field experiment aboard a martian BALloon) to investigate the magnetic field on the surface of Mars. The dual sensor fluxgate magnetometer is part of the MARS-98/MARS-TOGETHER balloon payload. During a ten days period the balloon will float over a distance of about 2000 km at altitudes between 0 and 4 km. Due to the limited power and telemetry allocation the magnetometer can transmit only one vector per ten seconds and spectral information in the frequency range from 2 - 25 Hz. The dynamic range is +/- 2000 nT. The main scientific objectives of the experiment are: • Determination of the magnetism of the Martian rocks • Investigation of the leakage of the solar wind induced magnetosphere using the correlation between orbiter and balloon observations • Measurement of the magnetic field profile between the orbiter and the surface of Mars during the descent phase of the balloon. Terrestrial test flights with a hot air balloon were performed in order to test the original MAGIBAL equipment under balloon flight conditions.

  18. Systematic optimization of exterior measurement locations for the determination of interior magnetic field vector components in inaccessible regions

    Energy Technology Data Exchange (ETDEWEB)

    Nouri, N.; Plaster, B.

    2014-12-11

    An experiment may face the challenge of real-time determination of the magnetic field vector components present within some interior region of the experimental apparatus over which it is impossible to directly measure the field components during the operation of the experiment. As a solution to this problem, we propose a general concept which provides for a unique determination of the field components within such an interior region solely from exterior measurements at fixed discrete locations. The method is general and does not require the field to possess any type of symmetry. We describe our systematic approach for optimizing the locations of these exterior measurements which maximizes their sensitivity to successive terms in a multipole expansion of the field.

  19. Estimating adhesive seed-dispersal distances : field experiments and correlated random walks

    NARCIS (Netherlands)

    Mouissie, AM; Lengkeek, W; van Diggelen, R

    1. In this study we aimed to estimate distance distributions of adhesively dispersed seeds and the factors that determine them. 2. Seed attachment and detachment were studied using field experiments with a real sheep, a sheep dummy and a cattle dummy. Seed-retention data were used in correlated

  20. Biocide leaching during field experiments on treated articles.

    Science.gov (United States)

    Schoknecht, Ute; Mathies, Helena; Wegner, Robby

    2016-01-01

    Biocidal products can be sources of active substances in surface waters caused by weathering of treated articles. Marketing and use of biocidal products can be limited according to the European Biocidal Products Regulation if unacceptable risks to the environment are expected. Leaching of active substances from treated articles was observed in field experiments to obtain information on leaching processes and investigate the suitability of a proposed test method. Leaching under weathering conditions proceeds discontinuously and tends to decrease with duration of exposure. It does not only mainly depend on the availability of water but is also controlled by transport processes within the materials and stability of the observed substances. Runoff amount proved to be a suitable basis to compare results from different experiments. Concentrations of substances are higher in runoff collected from vertical surfaces compared to horizontal ones, whereas the leached amounts per surface area are higher from horizontal surfaces. Gaps in mass balances indicate that additional processes such as degradation and evaporation may be relevant to the fate of active substances in treated articles. Leached amounts of substances were considerably higher when the materials were exposed to intermittent water contact under laboratory conditions as compared to weathering of vertically exposed surfaces. Experiences from the field experiments were used to define parameters of a procedure that is now provided to fulfil the requirements of the Biocidal Products Regulation. The experiments confirmed that the amount of water which is in contact with exposed surfaces is the crucial parameter determining leaching of substances.

  1. Proton and deuterium NMR experiments in zero field

    International Nuclear Information System (INIS)

    Millar, J.M.

    1986-02-01

    High field solid-state NMR lineshapes suffer from inhomogeneous broadening since resonance frequencies are a function of molecular orientation. Time domain zero field NMR is a two-dimensional field-cycling technique which removes this broadening by probing the evolution of the spin system under zero applied field. The simplest version, the sudden transition experiment, induces zero field evolution by the sudden removal of the applied magnetic field. Theory and experimental results of this experiment and several variations using pulsed dc magnetic fuelds to initiate zero field evolution are presented. In particular, the pulsed indirect detection method allows detection of the zero field spectrum of one nuclear spin species via another (usually protons) by utilizing the level crossings which occur upon adiabatic demagnetization to zero field. Experimental examples of proton/deuteron systems are presented which demonstrate the method results in enhanced sensitivity relative to that obtained in sudden transition experiments performed directly on deuterium. High resolution 2 H NQR spectra of a series of benzoic acid derivatives are obtained using the sudden transition and indirect detection methods. Librational oscillations in the water molecules of barium chlorate monohydrate are studied using proton and deuterium ZF experiments. 177 refs., 88 figs., 2 tabs

  2. Global field experiments for potato simulations

    DEFF Research Database (Denmark)

    Raymundo, Rubí; Asseng, Senthold; Prasad, Rishi

    2018-01-01

    A large field potato experimental dataset has been assembled for simulation modeling. The data are from temperate, subtropical, and tropical regions across the world and include 87 experiments with 204 treatments. Treatments include nitrogen fertilizer, irrigation, atmospheric CO2 levels, tempera......A large field potato experimental dataset has been assembled for simulation modeling. The data are from temperate, subtropical, and tropical regions across the world and include 87 experiments with 204 treatments. Treatments include nitrogen fertilizer, irrigation, atmospheric CO2 levels...

  3. Field services experiences

    International Nuclear Information System (INIS)

    Colflesh, J.A.; Kruse, P.W.; Merluzzi, R.A.

    1985-01-01

    Combustion Engineering (C-E) is a large diversified manufacturer of products and services for the energy field. At this time, C-E has supplied the nuclear steam supply systems for eleven operating nuclear power plants with two additional units currently undergoing start-up testing. The focus of C-E's commitment in the nuclear power plant services area is the Nuclear Services organization within the Nuclear Power Systems Division. The Nuclear Services organization provides services on a timely cost efficient basis; and dedicates resources to developing new products and services which are truly responsive to the needs of operating power plants world wide. In the paper, C-E's capabilities and experience in the field of nuclear services are described. Highlighted are our capabilities in the areas of transition management services, operating services and engineering services

  4. The Kolar Gold Field experiment

    International Nuclear Information System (INIS)

    Sreekantan, B.V.

    1982-01-01

    Meson theory was propounded to explain the nuclear force which holds neutrons and protons inside the nucleus. Subsequently, quark theory was put forward to bring some order into an enormously large number of fundamental particles discovered in the hadron family. These two theories are briefly explained. The gravitational force, the electromagnetic force, the weak nuclear force and the strong nuclear force are the basic forces which determine the behaviour of fundamental particles when they are in close proximity. If the last three of the above-mentioned four forces are one or just different aspects of a single force, quarks and leptons can be mingled in the same theoretical framework indicating the non-conservation of baryon number and the spontaneous decay of the proton into leptons. In order to test the last possibility i.e. proton decay, an experiment has been set up in the Kolar Gold Field at a depth of 2300 metres in India. 1650 gas proportional counters are sandwiched between iron plates. The total amount of iron in the form of iron plates and walls of the counters is 140 tons. In this experiment, nuclei of iron are serving as the source of protons and neutrons and the depth eliminates the background events which mimic proton decay. The amount of iron used in the experiment i.e. 140 tons is more than enough to obtain evidence of 10 proton decay events in a year, assuming that the lifetime of proton is 10 30 years or below. (M.G.B.)

  5. Dark matter effective field theory scattering in direct detection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schneck, K.; Cabrera, B.; Cerdeño, D. G.; Mandic, V.; Rogers, H. E.; Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Barker, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Brandt, D.; Brink, P. L.; Bunker, R.; Caldwell, D. O.; Calkins, R.; Chagani, H.; Chen, Y.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jardin, D. M.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Leder, A.; Loer, B.; Lopez Asamar, E.; Lukens, P.; Mahapatra, R.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Morales Mendoza, J. D.; Oser, S. M.; Page, K.; Page, W. A.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Roberts, A.; Saab, T.; Sadoulet, B.; Sander, J.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Toback, D.; Upadhyayula, S.; Villano, A. N.; Welliver, B.; Wilson, J. S.; Wright, D. H.; Yang, X.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2015-05-18

    We examine the consequences of the effective field theory (EFT) of dark matter–nucleon scattering for current and proposed direct detection experiments. Exclusion limits on EFT coupling constants computed using the optimum interval method are presented for SuperCDMS Soudan, CDMS II, and LUX, and the necessity of combining results from multiple experiments in order to determine dark matter parameters is discussed. We demonstrate that spectral differences between the standard dark matter model and a general EFT interaction can produce a bias when calculating exclusion limits and when developing signal models for likelihood and machine learning techniques. We also discuss the implications of the EFT for the next-generation (G2) direct detection experiments and point out regions of complementarity in the EFT parameter space.

  6. Magnetic field saturation in the Riga dynamo experiment.

    Science.gov (United States)

    Gailitis, A; Lielausis, O; Platacis, E; Dement'ev, S; Cifersons, A; Gerbeth, G; Gundrum, T; Stefani, F; Christen, M; Will, G

    2001-04-02

    After the dynamo experiment in November 1999 [A. Gailitis et al., Phys. Rev. Lett. 84, 4365 (2000)] had shown magnetic field self-excitation in a spiraling liquid metal flow, in a second series of experiments emphasis was placed on the magnetic field saturation regime as the next principal step in the dynamo process. The dependence of the strength of the magnetic field on the rotation rate is studied. Various features of the saturated magnetic field are outlined and possible saturation mechanisms are discussed.

  7. Why making an experiment susceptible of determining the velocity of the gravitational interaction is compulsory

    International Nuclear Information System (INIS)

    Cristea, G.

    1975-01-01

    In papers /1,2,3/, some proposals were made concerning the effecting of certain experiments apt to leading to the determination of the velocity of the gravitational interaction. This paper brings into relief the fact that this determination can only be achieved by measuring the delayed gravitational field and not by measuring the propagation velocity of the gravitational radiation that remains as yet a controversial problem, both theoretically and experimentally. The possibility is shown of the existence of a gravitational effect not unlike the Poynting-Robertson light effect; the importance is discussed of its determination both in the spatial and the astronomical fields. Certain of the proposed mechanisms for explaining the gravitational interaction are run over, their nonviability being objectively pointed out. Finally, conclusions are drawn from the presented material as to the necessity of effecting experiments for the determination of the velocity of the gravitational interaction

  8. Field experiments on airborne moisture transport

    NARCIS (Netherlands)

    Oldengarm, J.; Gids, W.F. de

    1990-01-01

    Within the framework of the Dutch participation in the IEA Annex XIV “Condensation” field experiments have been carried out to study airbome moisture transport in realistic circumstances. The experiments were done in an unoccupied 3-story dwelling in Leidschendam in the Netherlands. Some of the

  9. Multi-Disciplinary Research Experiences Integrated with Industry –Field Experiences

    Directory of Open Access Journals (Sweden)

    Suzanne Lunsford

    2015-10-01

    Full Text Available The purpose of this environmentally inquiry-based lab was to allow the students to engage into real-world concepts that integrate industry setting (Ohio Aggregate Industrial Mineral Association with the academia setting. Our students are engaged into a field trip where mining occurs to start the problem based learning of how the heavy metals leak in the mining process. These heavy metals such as lead and indium in the groundwater are a serious concern for the environment (Environmental Protection Agency from the mining process. The field experiences at the mining process assist in building our students interest in developing sensors to detect heavy metals of concern such as lead and indium simultaneously by a unique electrochemistry technique called Square Wave Anodic Stripping Voltammetry (SWASV. The field experience assists building the students interest in real –world application and what qualities do they want the electrochemical sensor to possess to be successful for real world usage. During the field trip the students are engaged into learning novel instrumentation such as an SEM (Scanning Electron Microscope to study the working electrode sensor developed to understand the sensor surface morphology properties better as well. The integration of industry setting with academia has been a positive experience for our students that has allowed their understanding of real-world science research needs to succeed in an industrial setting of research.

  10. Numerical determination of the magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Kuo-Petravic, G.; Boozer, A.H.

    1986-03-01

    The structure of a magnetic field is determined by a one-degree of freedom, time-dependent Hamiltonian. This Hamiltonian is evaluated for a given field in a perturbed action-angle form. The location and the size of magnetic islands in the given field are determined from Hamiltonian perturbation theory and from an ordinary Poincare plot of the field line trajectories

  11. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments

    OpenAIRE

    V?lez, Mar?a Alejandra; Trujillo, Carlos Andres; Moros, Lina; Forero, Clemente

    2016-01-01

    Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism posi...

  12. Crystal field parameters in UCl4: Experiment versus theory

    International Nuclear Information System (INIS)

    Zolnierek, Z.; Gajek, Z.; Khan Malek, C.

    1984-01-01

    Crystal field effect on U 4+ ion with the 3 H 4 ground term in tetragonal ligand field of UCl 4 has been studied in detail. Crystal field parameters determined experimentally from optical spectroscopy and magnetic susceptibility are in good agreement with CEP sets derived from the modified point charge model and the ab initio method. Theoretical calculations lead to overestimating the A 4 4 4 > and lowering the A 2 0 2 > values in comparison to those found in the experiments. The discrepancies are, however, within an accuracy of calculations. A large reduction of expectation values of the magnetic moment operator for the eigenvectors of lowest CF levels (17.8%), determined from magnetic susceptibility, cannot be attributed to the overlap and covalency effects only. The detailed calculations have shown that the latter effects provide about 4.6% reduction of respective matrix elements, and the applied J-J mixing procedure increases this factor up to 6.5%. Since similar, as in UCl 4 , reduction factor (proportional15%) has already been observed in a number of different uranium compounds, it seems to be likely that this feature is involved in the intrinsic properties of the U 4+ ion. We endeavor to explain this effect in terms of configuration interaction mechanisms. (orig.)

  13. Crystal field parameters in UCI 4: Experiment versus theory

    Science.gov (United States)

    Zolnierek, Z.; Gajek, Z.; Malek, Ch. Khan

    1984-08-01

    Crystal field effect on U 4+ ion with the 3H 4 ground term in tetragonal ligand field of UCl 4 has been studied in detail. Crystal field parameters determined experimentally from optical spectroscopy and magnetic susceptibility are in good agreement with CFP sets derived from the modified point charge model and the ab initio method. Theoretical calculations lead to overestimating the A44 and lowering the A02 values in comparison to those found in the experiments. The discrepancies are, however, within an accuracy of calculations. A large reduction of expectation values of the magnetic moment operator for the eigenvectors of lowest CF levels (17.8%), determined from magnetic susceptibility, cannot be attributed to the overlap and covalency effects only. The detailed calculations have shown that the latter effects provide about 4.6% reduction of respective matrix elements, and the applied J-J mixing procedure increases this factor up to 6.5%. Since similar, as in UCl 4, reduction factor(≈15%) has already been observed in a number of different uranium compounds, it seems likely that this feature is involved in the intrinsic properties of the U 4+ ion. We endeavor to explain this effect in terms of configuration interaction mechanisms.

  14. Field Experiments in Behavioral and Public Economics

    OpenAIRE

    Bhanot, Syon Pandya

    2015-01-01

    The three essays in this dissertation present field experiments exploring phenomena in behavioral and public economics in real-world settings. The first essay outlines a field experiment that uses mailers with peer rank information to motivate water conservation. The essay contributes some of the first pieces of evidence on how comparisons with specific peers might influence behavior. The main finding is that while competitive framing of peer information has positive impacts on efficient h...

  15. Preliminary experiments with a cusp-field ion source

    International Nuclear Information System (INIS)

    Bickes, R.W. Jr.; O'Hagan, J.B.

    1980-12-01

    Preliminary experiments with a cusp field ion source have been completed. Measurements were made of the total ion current and mass and energy distributions as a function of source operating conditions and cusp field geometry. These experiments have indicated that a cusp field source may be used in the Sandia Neutron Generator for Cancer Therapy and may permit the incorporation of a simplified unpumped accelerator design. Suggestions for future work are briefly outlined

  16. Further studies on the problems of geomagnetic field intensity determination from archaeological baked clay materials

    Science.gov (United States)

    Kostadinova-Avramova, M.; Kovacheva, M.

    2015-10-01

    Archaeological baked clay remains provide valuable information about the geomagnetic field in historical past, but determination of the geomagnetic field characteristics, especially intensity, is often a difficult task. This study was undertaken to elucidate the reasons for unsuccessful intensity determination experiments obtained from two different Bulgarian archaeological sites (Nessebar - Early Byzantine period and Malenovo - Early Iron Age). With this aim, artificial clay samples were formed in the laboratory and investigated. The clay used for the artificial samples preparation differs according to its initial state. Nessebar clay was baked in the antiquity, but Malenovo clay was raw, taken from the clay deposit near the site. The obtained artificial samples were repeatedly heated eight times in known magnetic field to 700 °C. X-ray diffraction analyses and rock-magnetic experiments were performed to obtain information about the mineralogical content and magnetic properties of the initial and laboratory heated clays. Two different protocols were applied for the intensity determination-Coe version of Thellier and Thellier method and multispecimen parallel differential pTRM protocol. Various combinations of laboratory fields and mutual positions of the directions of laboratory field and carried thermoremanence were used in the performed Coe experiment. The obtained results indicate that the failure of this experiment is probably related to unfavourable grain sizes of the prevailing magnetic carriers combined with the chosen experimental conditions. The multispecimen parallel differential pTRM protocol in its original form gives excellent results for the artificial samples, but failed for the real samples (samples coming from previously studied kilns of Nessebar and Malenovo sites). Obviously the strong dependence of this method on the homogeneity of the used subsamples hinders its implementation in its original form for archaeomaterials. The latter are often

  17. Technetium-99 behavior in the terrestrial environment. Field observations and radiotracer experiments

    International Nuclear Information System (INIS)

    Tagami, Keiko

    2003-01-01

    Obtaining data on 99 Tc in the rice paddy field environment is important because Tc is a redox sensitive element. The behavior of Tc is expected to be different under upland field and rice paddy field conditions since the redox conditions in the soil environment differ. However, most of the data on the nuclide behavior in soil were obtained under upland field conditions. To understand the global fallout 99 Tc distributions in soil samples collected in Japan, a simple and rapid separation method was developed in order to determine low-levels of 99 Tc in soil samples by an inductively coupled plasma mass spectrometry. Also, radiotracer experiments using soils under aerobic and anaerobic conditions were carried out to clarify the Tc behavior under paddy field conditions. The results of determination of global fallout 99 Tc in Japanese soils indicated that the radionuclide had been accumulating in rice paddy fields. The mechanisms can be explained by the immobilization of Tc in soil under anaerobic conditions. From the radiotracer experiments, it was clear that under waterlogged conditions, the highly mobile TcO 4 - in soil was readily changed to other immobilized forms, such as TcO 2 , TcS 2 and organically bound forms. To this immobilization, the microbial activity seemed to have an important role in Tc sorption reactions. When the soil, which was once kept in anaerobic conditions, was air-dried again and kept in aerobic conditions, the chemical forms of immobilized Tc did not change remarkably. Interestingly, the similar Tc behavior was observed in a real wet forest near the Chernobyl Reactor. (author)

  18. Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment.

    Directory of Open Access Journals (Sweden)

    Lucie Hemrová

    Full Text Available Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern.In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment.In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly correlated between the two

  19. Anomalous cross-field velocities in a CIV laboratory experiment

    International Nuclear Information System (INIS)

    Axnaes, I.

    1988-10-01

    The axial and radial ion velocities and the electron radial velocity are determined in coaxial plasma gun operated under critical velocity conditions. The particle celocities are determined from probe measurement together with He I 3889 AA absolute intensity measurements and the consideration of the total momentum balance of the current sheet. The ions are found move axially and the electrons radially much faster than predicted by the E/B drift in the macroscopic fields. These results agree with what can be expected from the instability processes, which has earlier been proposed to operate in these experiments. It is therefore a direct experimental demonstration that instability processes have to be invoked not only for the electron heating, but also to explain the macroscopic velocities and currents. (author)

  20. Junior physicians' workplace experiences in clinical fields in German-speaking Switzerland.

    Science.gov (United States)

    Buddeberg-Fischer, Barbara; Klaghofer, Richard; Abel, Thomas; Buddeberg, Claus

    2005-01-08

    To date, there have been several prospective cohort studies investigating the workplace experiences of junior physicians, but with limited focus on gender issues. The objective of the present study is to explore the workplace experiences of first-year residents according to gender, type of training hospital, and clinical field. Data reported are from the second assessment of the longitudinal Swiss physicians' career development study, begun in 2001. In 2003, 497 residents (54.7% females, 45.3% males) assessed their workplace conditions, social support at work, and effort-reward imbalance. There are few, but relevant, gender related differences in workplace experiences, with female physicians experiencing less mentoring and higher over-commitment, yet more positive social relationships at work. In a multivariate model, significant differences in some workplace variables with regard to type of training hospital and/or clinical field are found: workplace conditions are rated worse in type "A" hospitals (university and cantonal hospitals) than in type "B"/"C"/"D" hospitals (regional hospitals and highly specialised units), and in surgical fields than in internal medicine. In "A" hospitals mentoring is assessed as better, but positive social relationships as worse. Both scales are rated worse in surgical fields than in internal medicine. The effort-reward imbalance (ERI) is rated significantly higher (unfavourable) in "A" hospitals than in "B"/"C"/"D" hospitals, regardless of gender and clinical field. Significantly more subjects with an ERI quotient above 1 (which is unfavourable) work in "A" hospitals, and in surgical fields regardless of hospital type. Of the total sample, 81 subjects (16.3%), 41 males and 40 females, show an ERI quotient above 1. The greater the workload, the worse the rating of workplace conditions, effort-reward imbalance, and over-commitment. Institutional determinants are crucial factors for the workplace experiences and first career steps of

  1. Performance of a shallow-focus applied-magnetic-field diode for ion-beam-transport experiments

    Energy Technology Data Exchange (ETDEWEB)

    Young, F.C.; Neri, J.M.; Ottinger, P.F. [Naval Research Lab., Washington, DC (United States); Rose, D.V. [JAYCOR, Vienna (Vatican City State, Holy See); Jones, T.G.; Oliver, B.V.

    1997-12-31

    An applied-magnetic-field ion diode to study the transport of intense ion beams for light-ion inertial confinement fusion is being operated on the Gamble II generator at NRL. A Large-area (145-cm{sup 2}), shallow-focusing diode is used to provide the ion beam required for self-pinched transport (SPT) experiments. Experiments have demonstrated focusing at 70 cm for 1.2-MV, 40-kA protons. Beyond the focus, the beam hollows out consistent with 20--30 mrad microdivergence. The effect of the counter-pulse B-field on altering the ion-beam trajectories and improving the focus has been diagnosed with a multiple-pinhole-camera using radiachromic film. This diagnostic is also used to determine the radial and azimuthal uniformity of ion emission at the anode for different B-field conditions. Increasing the diode voltage to 1.5 MV and optimizing the ion current are planned before initiating SPT experiments. Experiments to measure the spatial beam profile at focus, i.e., the SPT channel entrance, are in progress. Results are presented.

  2. Soil treatment technologies: Comparison of field experiences

    International Nuclear Information System (INIS)

    Hodges, H.I.; Jackson, D.W.; Kline, K.

    1992-01-01

    A number of on-site soil treatment technologies are available for closure of oil-field waste pits, leaking underground storage tank (LUST) sites, and general hydrocarbon contamination. This paper will contrast Separation Systems Consultants, Inc.'s (SSCI's) field experiences with the following soil restoration techniques: (1) Land Treatment using indigenous microbes; (2) Land Farming using commercial microbes; (3) Low Temperature Thermal Treatment; (4) Solidification. The technologies will be contrasted in terms of regulatory constraints and requirements, key set-up and maintenance consideration, selection factors. Included in the regulatory contrast is the authors' perception of regulatory attitudes toward the techniques. Because this paper is based on actual field experience and projects, the practical aspects of making the technologies work is emphasized

  3. The magnetic field experiment onboard Equator-S and its scientific possibilities

    Directory of Open Access Journals (Sweden)

    K.-H. Fornacon

    1999-12-01

    Full Text Available The special feature of the ringcore fluxgate magnetometer on Equator-S is the high time and field resolution. The scientific aim of the experiment is the investigation of waves in the 10–100 picotesla range with a time resolution up to 64 Hz. The instrument characteristics and the influence of the spacecraft on the magnetic field measurement will be discussed. The work shows that the applied pre- and inflight calibration techniques are sufficient to suppress spacecraft interferences. The offset in spin axis direction was determined for the first time with an independent field measurement by the Equator-S Electron Drift Instrument. The data presented gives an impression of the accuracy of the measurement.Key words. Magnetospheric physics (instruments and techniques · Space plasma physics (instruments and techniques

  4. The magnetic field experiment onboard Equator-S and its scientific possibilities

    Directory of Open Access Journals (Sweden)

    K.-H. Fornacon

    Full Text Available The special feature of the ringcore fluxgate magnetometer on Equator-S is the high time and field resolution. The scientific aim of the experiment is the investigation of waves in the 10–100 picotesla range with a time resolution up to 64 Hz. The instrument characteristics and the influence of the spacecraft on the magnetic field measurement will be discussed. The work shows that the applied pre- and inflight calibration techniques are sufficient to suppress spacecraft interferences. The offset in spin axis direction was determined for the first time with an independent field measurement by the Equator-S Electron Drift Instrument. The data presented gives an impression of the accuracy of the measurement.

    Key words. Magnetospheric physics (instruments and techniques · Space plasma physics (instruments and techniques

  5. Entrepreneurship, teams and sustainability: A series of field experiments

    NARCIS (Netherlands)

    Rosendahl Huber, L.

    2015-01-01

    This dissertation reports the results from three field experiments that were conducted within the setting of one of the leading, internationally renowned entrepreneurship education programs for primary schools called BizWorld. The first field experiment evaluates the program’s effectiveness in terms

  6. A Field Experiment in Motivating Employee Ideas

    NARCIS (Netherlands)

    M. Gibbs (Michael); S. Neckermann (Susanne); C. Siemroth (Christoph)

    2014-01-01

    markdownabstract__Abstract__ We study the effects of a field experiment designed to motivate employee ideas, at a large technology company. Employees were encouraged to submit ideas on process and product improvements via an online system. In the experiment, the company randomized 19 account

  7. Field experiment with liquid manure and enhanced biochar

    Science.gov (United States)

    Dunst, Gerald

    2017-04-01

    Field experiments with low amounts of various liquid manure enhanced biochars. In 2016 a new machine was developed to inject liquid biochar based fertilizer directly into the crop root zone. A large-scale field experiment with corn and oil seed pumpkin was set-up on 42 hectares on 15 different fields in the south East of Austria. Three treatments were compared: (1) surface spreading of liquid manure as control (common practice), (2) 20 cm deep root zone injection with same amount of liquid manure, and (3) 20 cm deep root zone injection with same amount of liquid manure mixed with 1 to 2 tons of various nutrient enhanced biochars. The biochar were quenched with the liquid phase from a separated digestate from a biogas plant (feedstock: cow manure). From May to October nitrate and ammonium content was analyzed monthly from 0-30cm and 30-60cm soil horizons. At the end of the growing season the yield was determined. The root zone injection of the liquid manure reduced the nitrate content during the first two months at 13-16% compared to the control. When the liquid manure was blended with biochar, Nitrate soil content was lowest (reduction 40-47%). On average the root zone injection of manure-biochar increased the yield by 7% compared to the surface applied control and 3% compared to the root zone injected manure without biochar. The results shows, that biochar is able to reduce the Nitrate load in soils and increase the yield of corn at the same time. The nutrient efficiency of organic liquid fertilizers can be increased.

  8. Determination of the saturation magnetization, anisotropy field, mean field interaction, and switching field distribution for nanocrystalline hard magnets

    International Nuclear Information System (INIS)

    McCallum, R. William

    2005-01-01

    For a uniaxial nanocrystalline magnetic material, the determination of the saturation magnetization, M s , requires measurements of the magnetization at fields which exceed the anisotropy field. For a typical RE-Tm compound, where RE=rare earth and Tm=transition metal, this may require fields above 7 T if the approach to saturation law is used. However for an isotropic material composed of a random distribution of non-interacting uniaxial grains, both M s and the anisotropy filed, H a , may be determined by fitting the Stoner-Wohlfarth (SW) model (Philos. Trans. Roy. Soc. 240 (1948) 599) to the reversible part of the demagnetization curve in the first quadrant. Furthermore, using the mean field interaction model of Callen, Liu and Cullen [2], a quantitative measure of the interaction strength for interacting particles may be determined. In conjunction with an analytical fit to the first quadrant demagnetization curve of the SW model, this allows M s , H a and the mean field interaction constant of a nanocrystalline magnet to be determined from measurements below 5 T. Furthermore, comparison of the model solution for the reversible magnetization with experimental data in the 2nd and 3rd quadrants allows the accurate determination of the switching field distribution. In many cases the hysteresis loop may be accurately described by a normal distribution of switching fields

  9. Calculations of self-generated magnetic fields in parylene disc experiments

    International Nuclear Information System (INIS)

    Dahlbacka, G.H.; Mead, W.C.; Max, C.E.; Thomson, J.J.

    1975-01-01

    Experiments have been planned at Livermore to measure self-generated magnetic fields using the Faraday Rotation of frequency quadrupled 1.1 μm laser light. The LASNEX code was used during the planning of these experiments and has provided valuable information in establishing the conditions under which the thermoelectric fields expected can be measured. Suspected thermoelectric fields have been inferred from experiments that have been carried out at NRL

  10. Using Case Studies to Enrich Field Experience.

    Science.gov (United States)

    Florio-Ruane, Susan; Clark, Christopher M.

    1990-01-01

    This paper discusses the use of field experience in teacher education and how it can be augmented by phenomenological case studies. It summarizes a particular case study involving three teacher education classes, noting that reflective analysis of cases can prepare students to observe in the field. (SM)

  11. Wake field acceleration experiments

    International Nuclear Information System (INIS)

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics? I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs

  12. South American Field Experience: An Initiative in International Education. The Implementation Journal for the South American Field Experience.

    Science.gov (United States)

    Martin, William J.

    A description is provided of Williamsport Area Community College's (WACC's) South American Field Experience program, a travel/study program for faculty and staff designed to provide a variety of learning experiences through a three week trip to Peru, Chile, Argentina, and Brazil. Chapter I presents an overview of the development of the project,…

  13. Field experiments with subsurface releases of oil and and dyed water

    International Nuclear Information System (INIS)

    Rye, H.; Brandvik, P.J.; Strom, T.

    1998-01-01

    A field experiment with a subsurface release of oil and air was carried out in June 1996 close to the Frigg Field in the North Sea area. One of the purposes of this sea trial was to increase the knowledge concerning the behaviour of the oil and gas during a subsurface blowout. This was done by releasing oil and air at 106 meters depth with a realistic gas oil ratio (GOR=67) and release velocity of the oil. In addition to the oil release, several releases with dyed water and gas (GOR=7 - 65) were performed. Important and unique data were collected during these subsurface releases. In particular, the experiments with the dyed water releases combined with air turned out to be an efficient way of obtaining field data for the behaviour of subsurface plumes. The main conclusions from analysis for the data collected are: the field methodology used to study blowout releases in the field appears to be appropriate. The use of dyed water to determine the performance of the subsurface plume proved out to be an efficient way to obtain reliable and useful data. The behaviour of the subsurface plume is very sensitive to gas flow rates. For low gas flow rates, the plume did not reach the sea surface at all due to the presence of stratification in the ambient water. Some discrepancies were found between a numerical model for subsurface releases and field results. These discrepancies are pointed out, and recommendations for possible model improvements are given. (author)

  14. Determination of Coronal Magnetic Fields from Vector Magnetograms

    Science.gov (United States)

    Mikic, Zoran

    1997-01-01

    During the course of the present contract we developed an 'evolutionary technique' for the determination of force-free coronal magnetic fields from vector magnetograph observations. The method can successfully generate nonlinear force- free fields (with non-constant-a) that match vector magnetograms. We demonstrated that it is possible to determine coronal magnetic fields from photospheric measurements, and we applied it to vector magnetograms of active regions. We have also studied theoretical models of coronal fields that lead to disruptions. Specifically, we have demonstrated that the determination of force-free fields from exact boundary data is a well-posed mathematical problem, by verifying that the computed coronal field agrees with an analytic force-free field when boundary data for the analytic field are used; demonstrated that it is possible to determine active-region coronal magnetic fields from photospheric measurements, by computing the coronal field above active region 5747 on 20 October 1989, AR6919 on 15 November 1991, and AR7260 on 18 August 1992, from data taken with the Stokes Polarimeter at Mees Solar Observatory, University of Hawaii; started to analyze active region 7201 on 19 June 1992 using measurements made with the Advanced Stokes Polarimeter at NSO/Sac Peak; investigated the effects of imperfections in the photospheric data on the computed coronal magnetic field; documented the coronal field structure of AR5747 and compared it to the morphology of footpoint emission in a flare, showing that the 'high- pressure' H-alpha footpoints are connected by coronal field lines; shown that the variation of magnetic field strength along current-carrying field lines is significantly different from the variation in a potential field, and that the resulting near-constant area of elementary flux tubes is consistent with observations; begun to develop realistic models of coronal fields which can be used to study flare trigger mechanisms; demonstrated that

  15. Proposal for the ZT-40 reversed-field Z-pinch experiment

    International Nuclear Information System (INIS)

    Baker, D.A.; Machalek, M.D.

    1977-08-01

    A next-generation, toroidal, reversed-field Z-pinch experiment to be constructed at LASL is proposed. On the basis of encouraging ZT-I and ZT-S experimental results, a larger device with a 40-cm bore and a 114-cm major radius is proposed, to extend the confinement time by about an order of magnitude. The new experiment will explore the physics of programming reversed-field pinches in a size range unexplored by previous reversed-field pinch experiments. Model reversed-field pinch reactor calculations show that, if stability is assumed, small fusion reactors are possible if the pinch current density is high. A basic aim will be to delineate the plasma and current density ranges in which stable reversed-field pinches can be produced. Improved vacuum techniques will be used to overcome the radiation losses that probably kept electron temperatures low in the earlier, smaller experiments

  16. 160 Gb/s all-optical packet switching field experiment

    DEFF Research Database (Denmark)

    Dorren, H.J.S.; Herrera, J.; Raz, O.

    2007-01-01

    We discus an all-optical packet switching experiment over 110 km of field installed optical fiber. The switching node is controlled by solely photonic control circuits.......We discus an all-optical packet switching experiment over 110 km of field installed optical fiber. The switching node is controlled by solely photonic control circuits....

  17. Classroom and Field Experiments for Florida's Environmental Resources.

    Science.gov (United States)

    Lewis, Jim

    This booklet is intended to help teachers in Florida manage the growing interest in environmental education. Fourteen experiments are grouped into the environmental areas of the water cycle, groundwater, water pollution, waste and water treatment, air pollution, and field experiments. Experiments include demonstrations of the water cycle, the…

  18. Analysis of ARAC participation in the Idaho field experiment

    International Nuclear Information System (INIS)

    Rosen, L.C.; Hill, K.L.

    1986-02-01

    The 1981 Idaho Field Experiment to coordinate data sets and evaluate model and computer facilities is summarized herein. Participation of the Atmospheric Release Advisory Capability (ARAC) of the Lawrence Livermore National Laboratory in the field experiment is discussed. The computed ARAC results are compared with the observational data sets and analyzed. 12 refs., 44 figs., 3 tabs

  19. Global field experiments for potato simulations

    NARCIS (Netherlands)

    Raymundo, Rubi; Asseng, Senthold; Prasad, Rishi; Kleinwechter, Ulrich; Condori, Bruno; Bowen, Walter; Wolf, Joost; Olesen, Jørgen E.; Dong, Qiaoxue; Zotarelli, Lincoln; Gastelo, Manuel; Alva, Ashok; Travasso, Maria; Arora, Vijay

    2018-01-01

    A large field potato experimental data set has been assembled for simulation modeling. The data are from temperate, subtropical, and tropical regions across the world and include 87 experiments with 204 treatments. Treatments include nitrogen fertilizer, irrigation, atmospheric CO2 levels,

  20. Crystal field parameters in UCl/sub 4/: Experiment versus theory

    Energy Technology Data Exchange (ETDEWEB)

    Zolnierek, Z.; Gajek, Z. (Polska Akademia Nauk, Wroclaw. Inst. Niskich Temperatur i Badan Strukturalnych); Khan Malek, C. (Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire)

    1984-08-01

    Crystal field effect on U/sup 4 +/ ion with the /sup 3/H/sub 4/ ground term in tetragonal ligand field of UCl/sub 4/ has been studied in detail. Crystal field parameters determined experimentally from optical spectroscopy and magnetic susceptibility are in good agreement with CEP sets derived from the modified point charge model and the ab initio method. Theoretical calculations lead to overestimating the A/sub 4//sup 4/ and lowering the A/sub 2//sup 0/ values in comparison to those found in the experiments. The discrepancies are, however, within an accuracy of calculations. A large similar reduction of expectation values of the magnetic moment operator for the eigenvectors of lowest CF levels (17.8%), determined from magnetic susceptibility, cannot be attributed to the overlap and covalency effects only. The detailed calculations have shown that the latter effects provide about 4.6% reduction of respective matrix elements, and the applied J-J mixing procedure increases this factor up to 6.5%. Since similar reduction factor has already been observed in a number of different uranium compounds, as in UCl/sub 4/ it seems to be likely that this feature is involved in the intrinsic properties of the U/sup 4 +/ ion. The authors endeavor to explain this effect in terms of configuration interaction mechanisms.

  1. Design experiences for medical irradiation field at the musashi reactor

    International Nuclear Information System (INIS)

    Aizawa, Otohiko

    1994-01-01

    The design of the medical irradiation field at the Musashi reactor was carried out from 1974 to 1975, about 20 years ago. Various numerical analyses have been carried out recently, and it is astonishing to find out that the performance close to the optimum as a 100 kW reactor has been obtained. The reason for this is that the design was carried out by dividing into the stationary part and the moving part, and as for the moving part, the structure was determined by repeating trial and error and experiments. In this paper, the comparison of the analysis carried out later with the experimental data and the change of the absorbed dose at the time of medical irradiation accompanying the change of neutron energy spectra are reported. As the characteristics of the medical irradiation field at the Musashi reactor, the neutron energy spectra and the absorbed dose and mean medical irradiation time are shown. As the problems in boron neutron capture therapy, the neutron fluence required for the therapy, the way of thinking on background dose, and the problem of determining the irradiation time are discussed. The features of epithermal neutron beam are explained. (K.I.)

  2. Determining the field emitter temperature during laser irradiation in the pulsed laser atom probe

    International Nuclear Information System (INIS)

    Kellogg, G.L.

    1981-01-01

    Three methods are discussed for determining the field emitter temperature during laser irradiation in the recently developed Pulsed Laser Atom Probe. A procedure based on the reduction of the lattice evaporation field with increasing emitter temperature is found to be the most convenient and reliable method between 60 and 500 K. Calibration curves (plots of the evaporation field versus temperature) are presented for dc and pulsed field evaporation of W, Mo, and Rh. These results show directly the important influence of the evaporation rate on the temperature dependence of the evaporation field. The possibility of a temperature calibration based on the ionic charge state distribution of field evaporated lattice atoms is also discussed. The shift in the charge state distributions which occurs when the emitter temperature is increased and the applied field strength is decreased at a constant rate of evaporation is shown to be due to the changing field and not the changing temperature. Nevertheless, the emitter temperature can be deduced from the charge state distribution for a specified evaporation rate. Charge state distributions as a function of field strength and temperature are presented for the same three materials. Finally, a preliminary experiment is reported which shows that the emitter temperature can be determined from field ion microscope observations of single atom surface diffusion over low index crystal planes. This last calibration procedure is shown to be very useful at higher temperatures (>600 K) where the other two methods become unreliable

  3. Self-generated magnetic fields in direct-drive implosion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Igumenshchev, I. V.; Nilson, P. M.; Goncharov, V. N. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States); Zylstra, A. B.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-06-15

    Electric and self-generated magnetic fields in direct-drive implosion experiments on the OMEGA Laser Facility were investigated employing radiography with ∼10- to 60-MeV protons. The experiment used plastic-shell targets with imposed surface defects (glue spots, wires, and mount stalks), which enhance self-generated fields. The fields were measured during the 1-ns laser drive with an on-target intensity ∼10{sup 15} W/cm{sup 2}. Proton radiographs show multiple ring-like structures produced by electric fields ∼10{sup 7} V/cm and fine structures from surface defects, indicating self-generated fields up to ∼3 MG. These electric and magnetic fields show good agreement with two-dimensional magnetohydrodynamic simulations when the latter include the ∇T{sub e} × ∇n{sub e} source, Nernst convection, and anisotropic resistivity. The simulations predict that self-generated fields affect heat fluxes in the conduction zone and, through this, affect the growth of local perturbations.

  4. Critical bias fields for tilting stability in the BETA-II experiment

    International Nuclear Information System (INIS)

    Dalhed, H.E.

    1981-01-01

    The PEST equilibrium code and the GATO ideal MHD stability code have been modified to study stability properties of Spheromak configurations. Of particular interest is the effect on tilting modes of perfectly conducting walls which do not link the plasma. This paper makes use of equilibria and conducting walls specifically designed to model the BETA-II experiment at LLNL. Onset of the tilting mode is determined as a function of the bias magnetic field. Comparison with available experimental data shows promising agreement with the numerical results

  5. Field Trips as Valuable Learning Experiences in Geography Courses

    Science.gov (United States)

    Krakowka, Amy Richmond

    2012-01-01

    Field trips have been acknowledged as valuable learning experiences in geography. This article uses Kolb's (1984) experiential learning model to discuss how students learn and how field trips can help enhance learning. Using Kolb's experiential learning theory as a guide in the design of field trips helps ensure that field trips contribute to…

  6. Superparamagnetic beads in rotating magnetic fields: microfluidic experiments

    NARCIS (Netherlands)

    Den Toonder, J.M.J.; Bokdam, M.

    2008-01-01

    The effect of the Mason number, ratio of viscous and magnetic force, on suspended superparamagnetic micro sized beads was investigated experimentally. Microfluidic experiments were performed in a set-up that generates a rotating homogeneous magnetic field. In the presence of a magnetic field, the

  7. Sample cell for in-field X-ray diffraction experiments

    Directory of Open Access Journals (Sweden)

    Viktor Höglin

    2015-01-01

    Full Text Available A sample cell making it possible to perform synchrotron radiation X-ray powder diffraction experiments in a magnetic field of 0.35 T has been constructed. The device is an add-on to an existing sample cell and contains a strong permanent magnet of NdFeB-type. Experiments have shown that the setup is working satisfactory making it possible to perform in-field measurements.

  8. Calculations of transient fields in the Felix experiments at Argonne using null field integrated techniques

    International Nuclear Information System (INIS)

    Han, H.C.; Davey, K.R.; Turner, L.

    1985-08-01

    The transient eddy current problem is characteristically computationally intensive. The motivation for this research was to realize an efficient, accurate, solution technique involving small matrices via an eigenvalue approach. Such a technique is indeed realized and tested using the null field integral technique. Using smart (i.e., efficient, global) basis functions to represent unknowns in terms of a minimum number of unknowns, homogeneous eigenvectors and eigenvalues are first determined. The general excitatory response is then represented in terms of these eigenvalues/eigenvectors. Excellent results are obtained for the Argonne Felix cylinder experiments using a 4 x 4 matrix. Extension to the 3-D problem (short cylinder) is set up in terms of an 8 x 8 matrix

  9. Cockle Field Caging Experiment Data (2014)

    Data.gov (United States)

    U.S. Environmental Protection Agency — To determine whether differences in cockle density or qualitative burial depth observed during the 2014 field survey were affected by green macroalgal (GMA) mats, we...

  10. Theoretical considerations and preparatory experiments for poloidal field measurements in tokamaks by far-infrared polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, W; Dodel, G [Stuttgart Univ. (TH) (Germany, F.R.). Inst. fuer Plasmaforschung

    1978-12-01

    Numerical calculations give an optimum wavelength and show the precision requirements for determining poloidal field profiles in tokamaks on the basis of the Faraday effect. The required precision of the polarimetric measurements can be achieved in the far-infrared as is verified in a model experiment using a ferrite modulated HCN laser beam.

  11. The determination of high-resolution spatio-temporal glacier motion fields from time-lapse sequences

    Science.gov (United States)

    Schwalbe, Ellen; Maas, Hans-Gerd

    2017-12-01

    This paper presents a comprehensive method for the determination of glacier surface motion vector fields at high spatial and temporal resolution. These vector fields can be derived from monocular terrestrial camera image sequences and are a valuable data source for glaciological analysis of the motion behaviour of glaciers. The measurement concepts for the acquisition of image sequences are presented, and an automated monoscopic image sequence processing chain is developed. Motion vector fields can be derived with high precision by applying automatic subpixel-accuracy image matching techniques on grey value patterns in the image sequences. Well-established matching techniques have been adapted to the special characteristics of the glacier data in order to achieve high reliability in automatic image sequence processing, including the handling of moving shadows as well as motion effects induced by small instabilities in the camera set-up. Suitable geo-referencing techniques were developed to transform image measurements into a reference coordinate system.The result of monoscopic image sequence analysis is a dense raster of glacier surface point trajectories for each image sequence. Each translation vector component in these trajectories can be determined with an accuracy of a few centimetres for points at a distance of several kilometres from the camera. Extensive practical validation experiments have shown that motion vector and trajectory fields derived from monocular image sequences can be used for the determination of high-resolution velocity fields of glaciers, including the analysis of tidal effects on glacier movement, the investigation of a glacier's motion behaviour during calving events, the determination of the position and migration of the grounding line and the detection of subglacial channels during glacier lake outburst floods.

  12. Measurement and tricubic interpolation of the magnetic field for the OLYMPUS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bernauer, J.C. [Massachusetts Institute of Technology, Laboratory for Nuclear Science, Cambridge, MA (United States); Diefenbach, J. [Hampton University, Hampton, VA (United States); Elbakian, G. [Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan (Armenia); Gavrilov, G. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Goerrissen, N. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Hasell, D.K.; Henderson, B.S. [Massachusetts Institute of Technology, Laboratory for Nuclear Science, Cambridge, MA (United States); Holler, Y. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Karyan, G. [Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan (Armenia); Ludwig, J. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Marukyan, H. [Alikhanyan National Science Laboratory (Yerevan Physics Institute), Yerevan (Armenia); Naryshkin, Y. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); O' Connor, C.; Russell, R.L.; Schmidt, A. [Massachusetts Institute of Technology, Laboratory for Nuclear Science, Cambridge, MA (United States); Schneekloth, U. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Suvorov, K.; Veretennikov, D. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation)

    2016-07-01

    The OLYMPUS experiment used a 0.3 T toroidal magnetic spectrometer to measure the momenta of outgoing charged particles. In order to accurately determine particle trajectories, knowledge of the magnetic field was needed throughout the spectrometer volume. For that purpose, the magnetic field was measured at over 36,000 positions using a three-dimensional Hall probe actuated by a system of translation tables. We used these field data to fit a numerical magnetic field model, which could be employed to calculate the magnetic field at any point in the spectrometer volume. Calculations with this model were computationally intensive; for analysis applications where speed was crucial, we pre-computed the magnetic field and its derivatives on an evenly spaced grid so that the field could be interpolated between grid points. We developed a spline-based interpolation scheme suitable for SIMD implementations, with a memory layout chosen to minimize space and optimize the cache behavior to quickly calculate field values. This scheme requires only one-eighth of the memory needed to store necessary coefficients compared with a previous scheme (Lekien and Marsden, 2005 [1]). This method was accurate for the vast majority of the spectrometer volume, though special fits and representations were needed to improve the accuracy close to the magnet coils and along the toroidal axis.

  13. Chaos in reversed-field-pinch plasma simulation and experiment

    International Nuclear Information System (INIS)

    Watts, C.; Newman, D.E.; Sprott, J.C.

    1994-01-01

    We investigate the possibility that chaos and simple determinism are governing the dynamics of reversed-field-pinch (RFP) plasmas using data from both numerical simulations and experiment. A large repertoire of nonlinear-analysis techniques is used to identify low-dimensional chaos. These tools include phase portraits and Poincare sections, correlation dimension, the spectrum of Lyapunov exponents, and short-term predictability. In addition, nonlinear-noise-reduction techniques are applied to the experimental data in an attempt to extract any underlying deterministic dynamics. Two model systems are used to simulate the plasma dynamics. These are the DEBS computer code, which models global RFP dynamics, and the dissipative trapped-electron-mode model, which models drift-wave turbulence. Data from both simulations show strong indications of low-dimensional chaos and simple determinism. Experimental data were obtained from the Madison Symmetric Torus RFP and consist of a wide array of both global and local diagnostic signals. None of the signals shows any indication of low-dimensional chaos or other simple determinism. Moreover, most of the analysis tools indicate that the experimental system is very high dimensional with properties similar to noise. Nonlinear noise reduction is unsuccessful at extracting an underlying deterministic system

  14. An Experimenting Field Approach for the Numerical Solution of Multiphase Flow in Porous Media

    KAUST Repository

    Salama, Amgad; Sun, Shuyu; Bao, Kai

    2015-01-01

    In this work, we apply the experimenting pressure field technique to the problem of the flow of two or more immiscible phases in porous media. In this technique, a set of predefined pressure fields are introduced to the governing partial differential equations. This implies that the velocity vector field and the divergence at each cell of the solution mesh can be determined. However, since none of these fields is the true pressure field entailed by the boundary conditions and/or the source terms, the divergence at each cell will not be the correct one. Rather the residue which is the difference between the true divergence and the calculated one is obtained. These fields are designed such that these residuals are used to construct the matrix of coefficients of the pressure equation and the right-hand side. The experimenting pressure fields are generated in the solver routine and are fed to the different routines, which may be called physics routines, which return to the solver the elements of the matrix of coefficients. Therefore, this methodology separates the solver routines from the physics routines and therefore results in simpler, easy to construct, maintain, and update algorithms.

  15. An Experimenting Field Approach for the Numerical Solution of Multiphase Flow in Porous Media

    KAUST Repository

    Salama, Amgad

    2015-07-14

    In this work, we apply the experimenting pressure field technique to the problem of the flow of two or more immiscible phases in porous media. In this technique, a set of predefined pressure fields are introduced to the governing partial differential equations. This implies that the velocity vector field and the divergence at each cell of the solution mesh can be determined. However, since none of these fields is the true pressure field entailed by the boundary conditions and/or the source terms, the divergence at each cell will not be the correct one. Rather the residue which is the difference between the true divergence and the calculated one is obtained. These fields are designed such that these residuals are used to construct the matrix of coefficients of the pressure equation and the right-hand side. The experimenting pressure fields are generated in the solver routine and are fed to the different routines, which may be called physics routines, which return to the solver the elements of the matrix of coefficients. Therefore, this methodology separates the solver routines from the physics routines and therefore results in simpler, easy to construct, maintain, and update algorithms.

  16. Field Experience Study in a Traditional Setting.

    Science.gov (United States)

    Perenich, Theresa A.

    1978-01-01

    A field experience in fashion marketing for Kansas State University students is described. The functions and responsibilities of the coordinator, the student, and the departmental supervisor are outlined, along with the evaluation processes used. (Author/LBH)

  17. Feasibility of field portable near infrared (NIR) spectroscopy to determine cyanide concentrations in soil

    Science.gov (United States)

    Sut, Magdalena; Fischer, Thomas; Repmann, Frank; Raab, Thomas

    2013-04-01

    In Germany, at more than 1000 sites, soil is polluted with an anthropogenic contaminant in form of iron-cyanide complexes. These contaminations are caused by former Manufactured Gas Plants (MGPs), where electricity for lighting was produced in the process of coal gasification. The production of manufactured gas was restrained in 1950, which caused cessation of MGPs. Our study describes the application of Polychromix Handheld Field Portable Near-Infrared (NIR) Analyzer to predict the cyanide concentrations in soil. In recent times, when the soil remediation is of major importance, there is a need to develop rapid and non-destructive methods for contaminant determination in the field. In situ analysis enables determination of 'hot spots', is cheap and time saving in comparison to laboratory methods. This paper presents a novel usage of NIR spectroscopy, where a calibration model was developed, using multivariate calibration algorithms, in order to determine NIR spectral response to the cyanide concentration in soil samples. As a control, the contaminant concentration was determined using conventional Flow Injection Analysis (FIA). The experiments revealed that portable near-infrared spectrometers could be a reliable device for identification of contamination 'hot spots', where cyanide concentration are higher than 2400 mg kg-1 in the field and >1750 mg kg-1 after sample preparation in the laboratory, but cannot replace traditional laboratory analyses due to high limits of detection.

  18. A Field Experiment in Motivating Employee Ideas

    OpenAIRE

    Susanne Neckermann; Michael Gibbs; Christoph Siemroth

    2014-01-01

    markdownabstract__Abstract__ We study the effects of a field experiment designed to motivate employee ideas, at a large technology company. Employees were encouraged to submit ideas on process and product improvements via an online system. In the experiment, the company randomized 19 account teams into treatment and control groups. Employees in treatment teams received rewards if their ideas were approved. Nothing changed for employees in control teams. Our main finding is that rewards substa...

  19. Chemical magnetization when determining Thellier paleointensity experiments in oceanic basalts

    Science.gov (United States)

    Tselebrovskiy, Alexey; Maksimochkin, Valery

    2017-04-01

    The natural remanent magnetization (NRM) of oceanic basalts selected in the rift zones of the Mid-Atlantic Ridge (MAR) and the Red Sea has been explored. Laboratory simulation shows that the thermoremanent magnetization and chemical remanent magnetization (CRM) in oceanic basalts may be separated by using Tellier-Coe experiment. It was found that the rate of CRM destruction is about four times lower than the rate of the partial thermoremanent magnetization formation in Thellier cycles. The blocking temperatures spectrum of chemical component shifted toward higher temperatures in comparison with the spectrum of primary thermoremanent magnetization. It was revealed that the contribution of the chemical components in the NRM increases with the age of oceanic basalts determined with the analysis of the anomalous geomagnetic field (AGF) and spreading theory. CRM is less than 10% at the basalts aged 0.2 million years, less than 50% at basalts aged 0.35 million years, from 60 to 80% at basalts aged 1 million years [1]. Geomagnetic field paleointensity (Hpl) has been determined through the remanent magnetization of basalt samples of different ages related to Brunhes, Matuyama and Gauss periods of the geomagnetic field polarity. The value of the Hpl determined by basalts of the southern segment of MAR is ranged from 17.5 to 42.5 A/m, by the Reykjanes Ridge basalts — from 20.3 to 44 A/m, by the Bouvet Ridge basalts — from 21.7 to 34.1 A/m. VADM values calculated from these data are in good agreement with the international paleointensity database [2] and PISO-1500 model [3]. Literature 1. Maksimochkin V., Tselebrovskiy A., (2015) The influence of the chemical magnetization of oceanic basalts on determining the geomagnetic field paleointensity by the thellier method, moscow university physics bulletin, 70(6):566-576, 2. Perrin, M., E. Schnepp, and V. Shcherbakov (1998), Update of the paleointensity database, Eos Trans. AGU, 79, 198. 3. Channell JET, Xuan C, Hodell DA (2009

  20. Across the Arctic Teachers Experience Field Research

    Science.gov (United States)

    Warnick, W. K.; Warburton, J.; Wiggins, H. V.; Marshall, S. A.; Darby, D. A.

    2005-12-01

    From studying snow geese on the North Slope of Alaska to sediment coring aboard the U.S. Coast Guard Cutter Healy in the Arctic Ocean, K-12 teachers embark on scientific expeditions as part of a program that strives to make science in the Arctic a "virtual" reality. In the past two years, seventeen K-12 teachers have participated in Teachers and Researchers Exploring and Collaborating (TREC), a program that pairs teachers with researchers to improve science education through arctic field experiences. TREC builds on the scientific and cultural opportunities of the Arctic, linking research and education through topics that naturally engage students and the wider public. TREC includes expeditions as diverse as studying plants at Toolik Field Station, a research facility located 150 miles above the Arctic Circle; climate change studies in Norway's Svalbard archipelago; studying rivers in Siberia; or a trans-arctic expedition aboard the USCGC Healy collecting an integrated geophysical data set. Funded by the National Science Foundation Office of Polar Programs, TREC offers educators experiences in scientific inquiry while encouraging the public and students to become active participants in the scientific inquiry by engaging them virtually in arctic research. TREC uses online outreach elements to convey the research experience to a broad audience. While in remote field locations, teachers and researchers interact with students and the public through online seminars and live calls from the field, online journals with accompanying photos, and online bulletin boards. Since the program's inception in 2004, numerous visitors have posted questions or interacted with teachers, researchers, and students through the TREC website (http://www.arcus.org/trec). TREC teachers are required to transfer their experience of research and current science into their classroom through the development of relevant activities and resources. Teachers and researchers are encouraged to participate

  1. Micro-scale hydrological field experiments in Romania

    Directory of Open Access Journals (Sweden)

    Minea Gabriel

    2016-02-01

    Full Text Available The paper (communication presents an overview of hydrologic field experiments at micro-scale in Romania. In order to experimentally investigate micro (plot-scale hydrological impact of soil erosion, the National Institute of Hydrology and Water Management founded Voineşti Experimental Basin (VES in 1964 and the Aldeni Experimental Basins (AEB in 1984. AEB and VES are located in the Curvature Subcarpathians. Experimental plots are organized in a double systems and have an area of 80 m2 (runoff plots at AEB and 300 m2 (water balance plots at VES. Land use of plot: first plot ”grass-land” is covered with perennial grass and second plot (control consists in ”bare soil”. Over the latter one, the soil is hoeing, which results in a greater development of infiltration than in the first plot. Experimental investigations at micro-scale are aimed towards determining the parameters of the water balance equation, during natural and artificial rainfalls, researching of flows and soil erosion processes on experimental plots, extrapolating relations involving runoff coefficients from a small scale to medium scale. Nowadays, the latest evolutions in data acquisition and transmission equipment are represented by sensors (such as: sensors to determinate the soil moisture content. Exploitation and dissemination of hydrologic data is accomplished by research themes/projects, year-books of basic data and papers.

  2. Tools and setups for experiments with AC and rotating magnetic fields

    International Nuclear Information System (INIS)

    Ponikvar, D

    2010-01-01

    A rotating magnetic field is the basis for the transformation of electrical energy to mechanical energy. School experiments on the rotating magnetic field are rare since they require the use of specially prepared mechanical setups and/or relatively large, three-phase power supplies to achieve strong magnetic fields. This paper proposes several experiments and describes setups and tools which are easy to obtain and work with. Free software is offered to generate the required signals by a personal computer. The experiments can be implemented in introductory physics courses on electromagnetism for undergraduates or specialized courses at high schools.

  3. Fate of diuron and linuron in a field lysimeter experiment.

    Science.gov (United States)

    Guzzella, L; Capri, E; Di Corcia, A; Barra Caracciolo, A; Giuliano, G

    2006-01-01

    The environmental fate of herbicides can be studied at different levels: in the lab with disturbed or undisturbed soil columns or in the field with suction cup lysimeters or soil enclosure lysimeters. A field lysimeter experiment with 10 soil enclosures was performed to evaluate the mass balance in different environmental compartments of the phenylurea herbicides diuron [3-(3,4-diclorophenyl)-1,1-dimethyl-urea] and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea]. After application on the agricultural soil, the herbicides were searched for in soil, pore water, and air samples. Soil and water samples were collected at different depths of the soil profile and analyzed to determine residual concentrations of both the parent compounds and of their main transformation products, to verify their persistence and their leaching capacity. Air volatilization was calculated using the theoretical profile shape method. The herbicides were detected only in the surface layer (0-10 cm) of soil. In this layer, diuron was reduced to 50% of its initial concentration at the end of the experiment, while linuron was still 70% present after 245 d. The main metabolites detected were DCPMU [3-(3,4-dichlorophenyl)-1-methylurea] and DCA (3,4-dichloroaniline). In soil pore water, diuron and linuron were detected at depths of 20 and 40 cm, although in very low concentrations. Therefore the leaching of these herbicides was quite low in this experiment. Moreover, volatilization losses were inconsequential. The calculated total mass balance showed a high persistence of linuron and diuron in the soil, a low mobility in soil pore water (less than 0.5% in leachate water), and a negligible volatilization effect. The application of the Pesticide Leaching Model (PELMO) showed similar low mobility of the chemicals in soil and water, but overestimated their volatilization and their degradation to the metabolite DCPMU. In conclusion, the use of soil enclosure lysimeters proved to be a good

  4. Random Assignment: Practical Considerations from Field Experiments.

    Science.gov (United States)

    Dunford, Franklyn W.

    1990-01-01

    Seven qualitative issues associated with randomization that have the potential to weaken or destroy otherwise sound experimental designs are reviewed and illustrated via actual field experiments. Issue areas include ethics and legality, liability risks, manipulation of randomized outcomes, hidden bias, design intrusiveness, case flow, and…

  5. Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

    Directory of Open Access Journals (Sweden)

    Xuefeng Chu

    2015-01-01

    Full Text Available Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events.

  6. Effects of a PID Control System on Electromagnetic Fields in an nEDM Experiment

    Science.gov (United States)

    Molina, Daniel

    2017-09-01

    The Kellogg Radiation Laboratory is currently testing a prototype for an experiment that hopes to identify the electric dipole moment of the neutron. As part of this testing, we have developed a PID (proportional, integral, derivative) feedback system that uses large coils to fix the value of local external magnetic fields, up to linear gradients. PID algorithms compare the current value to a set-point and use the integral and derivative of the field with respect to the set-point to maintain constant fields. We have also developed a method for zeroing linear gradients within the experimental apparatus. In order to determine the performance of the PID algorithm, measurements of both the internal and external fields were obtained with and without the algorithm running, and these results were compared for noise and time stability. We have seen that the PID algorithm can reduce the effect of disturbance to the field by a factor of 10.

  7. Toroidal magnetic field system for a 2-MA reversed-field pinch experiment

    International Nuclear Information System (INIS)

    Melton, J.G.; Linton, T.W.

    1983-01-01

    The engineering design of the toroidal magnetic field (TF) system for a 2-MA Reversed-Field Pinch experiment (ZT-H) is described. ZT-H is designed with major radius 2.15 meters, minor radius 0.40 meters, and a peak toroidal magnetic field of 0.85 Tesla. The requirement for highly uniform fields, with spatial ripple <0.2% leads to a design with 72 equally spaced circular TF coils, located at minor radius 0.6 meters, carrying a maximum current of 9.0 MA. The coils are driven by a 12-MJ capacitor bank which is allowed to ring in order to aid the reversal of magnetic field. A stress analysis is presented, based upon calculated hoop tension, centering force, and overturning moment, treating these as a combination of static loads and considering that the periodic nature of the loading causes little amplification. The load transfer of forces and moments is considered as a stress distribution resisted by the coils, support structures, wedges, and the structural shell

  8. Communication, Community, and Disconnection: Pre-Service Teachers in Virtual School Field Experiences

    Science.gov (United States)

    Wilkens, Christian; Eckdahl, Kelli; Morone, Mike; Cook, Vicki; Giblin, Thomas; Coon, Joshua

    2014-01-01

    This study examined the experiences of 11 graduate-level pre-service teachers completing Virtual School Field Experiences (VSFEs) with cooperating teachers in fully online, asynchronous high school courses in New York State. The VSFEs included a 7-week online teacher training course, and a 7-week online field experience. Pre-service teachers…

  9. MHD control experiments in the Extrap T2R Reversed Field Pinch

    Science.gov (United States)

    Marrelli, L.; Bolzonella, T.; Brunsell, P.; Cecconello, M.; Drake, J.; Franz, P.; Gregoratto, D.; Manduchi, G.; Martin, P.; Ortolani, S.; Paccagnella, R.; Piovesan, P.; Spizzo, G.; Yadikin, D.; Zanca, P.

    2004-11-01

    We report here on MHD active control experiments performed in the Extrap T2R device, which has been recently equipped with a set of 32 feedback controlled saddle coils couples. Experiments aiming at selectively exciting a resonant resistive instability in order to actively induce Quasi Single Helicity states will be presented. Open loop experiments have in fact shown that a spectrum with one dominant mode can be excited in a high aspect ratio device like T2R. In addition, evidences of controlled braking of tearing modes, which spontaneously rotate in T2R, have been gathered, allowing the determination of a threshold for mode wall locking. Different feedback control schemes have been implemented. In particular, mode suppression schemes proved successful in delaying resistive wall modes growth and in increasing the discharge duration: this suggests a hybrid mode control scenario, in which RWM are suppressed and QSH is induced. Radiation imaging and internal magnetic field reconstructions performed with the ORBIT code will be presented.

  10. Employee Recognition and Performance: A Field Experiment

    NARCIS (Netherlands)

    C. Bradler (Christiane); A.J. Dur (Robert); S. Neckermann (Susanne); J.A. Non (Arjan)

    2013-01-01

    textabstractThis paper reports the results from a controlled field experiment designed to investigate the causal effect of public recognition on employee performance. We hired more than 300 employees to work on a three-hour data-entry task. In a random sample of work groups, workers unexpectedly

  11. Employee recognition and performance: A field experiment

    NARCIS (Netherlands)

    Bradler, C.; Dur, R.; Neckermann, S.; Non, J.A.

    2013-01-01

    This paper reports the results from a controlled field experiment designed to investigate the causal effect of public recognition on employee performance. We hired more than 300 employees to work on a three-hour data-entry task. In a random sample of work groups, workers unexpectedly received

  12. Rethermalization of a field-reversed configuration plasma in translation experiments

    International Nuclear Information System (INIS)

    Himura, H.; Okada, S.; Sugimoto, S.; Goto, S.

    1995-01-01

    A translation experiment of field-reversed configuration (FRC) plasma is performed on the FIX machine [Shiokawa and Goto, Phys. Fluids B 5, 534 (1993)]. The translated FRC bounces between magnetic mirror fields at both ends of a confinement region. The plasma loses some of its axial kinetic energy when it is reflected by the magnetic mirror field, and eventually settles down in the confinement region. In this reflection process, the plasma temperature rises significantly. Such plasma rethermalization has been observed in OCT-L1 experiments [Ito et al., Phys. Fluids 30, 168 (1987)], but rarely in FRX-C/T experiments [Rej et al., Phys. Fluids 29, 852 (1986)]. It is found that the rethermalization depends on the relation between the plasma temperature and the translation velocity. The rethermalization occurs only in the case where the translation velocity exceeds the sound velocity. This result implies the rethermalization is caused by a shock wave induced within the FRC when the plasma is reflected by the magnetic mirror field. copyright 1995 American Institute of Physics

  13. On transient electric fields observed in chemical release experiments by rockets

    International Nuclear Information System (INIS)

    Marklund, G.; Brenning, N.; Holmgren, G.; Haerendel, G.

    1986-06-01

    As a follow-up to the successful chemical release experiment Trigger in 1977, the TOR (Trigger Optimized Repetition) rocket was launched from Esrange on Oct. 24, 1984. Like in the Trigger experiment a large amplitude electric field pulse of 200 mV/m was detected shortly after the explosion. The central part of the pulse was found to be clearly correlated with an intense layer of swept up ambient particles behind a propagating shock-front. The field was directed towards the centre of the expanding ionized cloud, which is indicative of a polarisation electric field source. Expressions for this radial polarisation field and the much weaker azimuthal induced electric field are derived from a simple cylindrical model for the field and the expanding neutral cloud. Time profiles of the radial electric field are shown to be in good agreement with observations. (authors)

  14. Megagauss field generation for high-energy-density plasma science experiments

    International Nuclear Information System (INIS)

    Rovang, Dean Curtis; Struve, Kenneth William; Porter, John Larry Jr.

    2008-01-01

    There is a need to generate magnetic fields both above and below 1 megagauss (100 T) with compact generators for laser-plasma experiments in the Beamlet and Petawatt test chambers for focused research on fundamental properties of high energy density magnetic plasmas. Some of the important topics that could be addressed with such a capability are magnetic field diffusion, particle confinement, plasma instabilities, spectroscopic diagnostic development, material properties, flux compression, and alternate confinement schemes, all of which could directly support experiments on Z. This report summarizes a two-month study to develop preliminary designs of magnetic field generators for three design regimes. These are, (1) a design for a relatively low-field (10 to 50 T), compact generator for modest volumes (1 to 10 cm3), (2) a high-field (50 to 200 T) design for smaller volumes (10 to 100 mm3), and (3) an extreme field (greater than 600 T) design that uses flux compression. These designs rely on existing Sandia pulsed-power expertise and equipment, and address issues of magnetic field scaling with capacitor bank design and field inductance, vacuum interface, and trade-offs between inductance and coil designs

  15. Utilizing Urban Environments for Effective Field Experiences

    Science.gov (United States)

    MacAvoy, S. E.; Knee, K.

    2014-12-01

    Research surveys suggest that students are demanding more applied field experiences from their undergraduate environmental science programs. For geoscience educators at liberal arts colleges without field camps, university vehicles, or even geology departments, getting students into the field is especially rewarding - and especially challenging. Here, we present strategies that we have used in courses ranging from introductory environmental science for non-majors, to upper level environmental methods and geology classes. Urban locations provide an opportunity for a different type of local "field-work" than would otherwise be available. In the upper-level undergraduate Environmental Methods class, we relied on a National Park area located a 10-minute walk from campus for most field exercises. Activities included soil analysis, measuring stream flow and water quality parameters, dendrochronology, and aquatic microbe metabolism. In the non-majors class, we make use of our urban location to contrast water quality in parks and highly channelized urban streams. Here we share detailed lesson plans and budgets for field activities that can be completed during a class period of 2.5 hours with a $75 course fee, show how these activities help students gain quantitative competency, and provide student feedback about the classes and activities.

  16. Teachers' Perceptions of Their Mentoring Role in Three Different Clinical Settings: Student Teaching, Early Field Experiences, and Entry Year Teaching

    Science.gov (United States)

    Gut, Dianne M.; Beam, Pamela C.; Henning, John E.; Cochran, Deborah C.; Knight, Rhonda Talford

    2014-01-01

    The purpose of this study was to determine the differences in mentoring across three different clinical settings: student teaching, early field experiences, and entry year teachers. Eighteen teachers with mentoring experience in all three clinical settings were selected and interviewed. The teachers' expectations for teacher development,…

  17. From Perceptual Apparatus to Immersive Field of Experience

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2014-01-01

    Peter Sloterdijk ascribes to architecture the “the design of immersions” and hence the “production of embedding situations” or atmosphere (2011 (2006): 108-109), which as devised by Gernot Böhme becomes a fundamental concept of a new aesthetics (1993). Atmosphere implies affective immersion...... the immersive experiences relocate the vision within a “carnal density” (1992: 150), regaining all sensory modalities. Diverse perceptual apparatuses also defined a larger disciplinary expansion in the field of architecture and design. Conceived as sensorial activators, intensifiers of phenomena......, constitute a framework for a re-invention of perceptual worlds, providing a basis for tracing the conceptual contours of atmospheric perception, as well as for discerning the means of the production of space understood as an immersive field of experience. References: Böhme, G. (1993). "Atmosphere...

  18. First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, M. J., E-mail: mros@lle.rochester.edu; Li, C. K.; Séguin, F. H.; Frenje, J. A.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Fox, W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Igumenshchev, I.; Stoeckl, C.; Glebov, V. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Town, R. P. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-04-15

    Novel experiments to study the strongly-driven collision of parallel magnetic fields in β ∼ 10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell simulations predict a stronger flux compression and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.

  19. Severe Weather Field Experience: An Undergraduate Field Course on Career Enhancement and Severe Convective Storms

    Science.gov (United States)

    Godfrey, Christopher M.; Barrett, Bradford S.; Godfrey, Elaine S.

    2011-01-01

    Undergraduate students acquire a deeper understanding of scientific principles through first-hand experience. To enhance the learning environment for atmospheric science majors, the University of North Carolina at Asheville has developed the severe weather field experience. Participants travel to Tornado Alley in the Great Plains to forecast and…

  20. Analysis of near-field data from a Soviet decoupling experiment

    International Nuclear Information System (INIS)

    Saikia, C.K.; McLaren, J.P.; Helmberger, D.V.

    1993-01-01

    Recently Adushkin et al. (1992a) presented some results on a decoupling experiment performed in a salt dome in Azghir near the Caspian Sea. A large coupled shot (64 kT) was followed five years later by a decoupled shot (8 kT) fired in the cavity formed by the earlier event. Both events were recorded locally and this data has been provided by the Soviet scientists in a cooperative effort to better understand the seismic coupling problem. This data, in conjunction with WWSSN observations, is analyzed in an effort to determine the RDP's and an estimate of t. Our preliminary results suggest that RDP appropriate for the large event is quite similar to that of LONGSHOT (80 kT event). Their teleseismic observations are difficult to distinguish in waveshape. The M s for LONGSHOT is 3.9 while that for the coupled Russian event is 3.3. The m b for the LONGSHOT (5.8) is slightly smaller than for the Russian event (m b = 6.0, ISC). This comparison of m b :M s appears to be common to most Azghir events as compared to the US experience. The t* appropriate for Amchitka (t* = 0.9) was established by near-field and teleseismic modeling of waveform data similar to this study where we obtain a t* = 0.5 to 0.6. The RDP for the small event is less well resolved but appears to be only partially decoupled. Prior estimates of decoupling factors range from 30 (based on this data by Adushkin) to 70 (for the Sterling/Salmon experiment). Our analysis produces a decoupling factor of about 15 using near-field data which is similar to the teleseismic modeling result

  1. 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

  2. The FIELDS experiment for Solar Probe Plus

    Science.gov (United States)

    Bale, S.; Spp/Fields Team

    2010-12-01

    Many of our basic ideas on the plasma physics of acceleration, energy flow, and dissipation, and structure of the solar wind have never been rigorously confronted by direct experimental measurements in the region where these processes are actually occurring. Although Alfven waves, shocks, and magnetic reconnection are often invoked as heating mechanisms, there have never been any direct measurements of Alfvenic waves nor the associated Poynting flux nor any measurements of ion or electron kinetic energy flux in the region from 10 R_s to 30 R_s where the final stages of wind acceleration are believed to occur. The radial profiles of both slow and fast solar wind acceleration are based on remote-sensing measurements and have been obtained for only a few selected events. Thus, the spatial radial and perpendicular scales of the acceleration process have been averaged by line-of-sight effects and the possibility of intense localized acceleration cannot be ruled out. The Solar Probe Plus (SPP) mission calls for the high quality fields and particles measurements required to solve the coronal heating and wind acceleration problem. The SPP 'FIELDS' experiment measures the electric and magnetic fields fundamental to the plasma physics of the structured and turbulent solar wind, flux ropes, collisionless shocks, and magnetic reconnection. FIELDS will make the first-ever measurements of the DC/Low-Frequency electric field inside of 1 AU allowing for in situ, high cadence measurements of the Poynting vector, the Elsasser variables, and E/B diagnostics of the wave spectrum to fce in the solar wind. SPP/FIELDS measures the radio wave (type III and II) signatures of microflares, energized electrons, and CME propagation. SPP/ FIELDS measures the plasma electron density to ~2% accuracy and the core electron temperature to ~5-10% accuracy more than 90% of the time at perihelion. FIELDS will also measure the in situ density fluctuation spectrum and structures at a very high cadence (

  3. Field determination of bacterial disappearance in seawater

    DEFF Research Database (Denmark)

    Harremoës, Poul

    1970-01-01

    The article presents two approaches to field determination of disappearance of viable, fecal bacteria after discharge with sewage into a marine environment. The first approach is based on simultaneous sampling for bacterial counting and monitoring of dilution using a conservative tracer, which is...

  4. A ``Cyber Wind Facility'' for HPC Wind Turbine Field Experiments

    Science.gov (United States)

    Brasseur, James; Paterson, Eric; Schmitz, Sven; Campbell, Robert; Vijayakumar, Ganesh; Lavely, Adam; Jayaraman, Balaji; Nandi, Tarak; Jha, Pankaj; Dunbar, Alex; Motta-Mena, Javier; Craven, Brent; Haupt, Sue

    2013-03-01

    The Penn State ``Cyber Wind Facility'' (CWF) is a high-fidelity multi-scale high performance computing (HPC) environment in which ``cyber field experiments'' are designed and ``cyber data'' collected from wind turbines operating within the atmospheric boundary layer (ABL) environment. Conceptually the ``facility'' is akin to a high-tech wind tunnel with controlled physical environment, but unlike a wind tunnel it replicates commercial-scale wind turbines operating in the field and forced by true atmospheric turbulence with controlled stability state. The CWF is created from state-of-the-art high-accuracy technology geometry and grid design and numerical methods, and with high-resolution simulation strategies that blend unsteady RANS near the surface with high fidelity large-eddy simulation (LES) in separated boundary layer, blade and rotor wake regions, embedded within high-resolution LES of the ABL. CWF experiments complement physical field facility experiments that can capture wider ranges of meteorological events, but with minimal control over the environment and with very small numbers of sensors at low spatial resolution. I shall report on the first CWF experiments aimed at dynamical interactions between ABL turbulence and space-time wind turbine loadings. Supported by DOE and NSF.

  5. Incentives versus sorting in tournaments: evidence from a field experiment

    NARCIS (Netherlands)

    Leuven, E.; Oosterbeek, H.; Sonnemans, J.; van der Klaauw, B.

    2011-01-01

    Existing field evidence on rank-order tournaments typically does not allow disentangling incentive and sorting effects. We conduct a field experiment illustrating the confounding effect. Students in an introductory microeconomics course selected themselves into tournaments with low, medium, or high

  6. Magnetic field line reconnection experiments

    International Nuclear Information System (INIS)

    Gekelman, W.; Stenzel, R.L.; Wild, N.

    1982-01-01

    A laboratory experiment concerned with the basic physics of magnetic field line reconnection is discussed. Stimulated by important processes in space plasmas and anomalous transport in fusion plasmas the work addresses the following topics: Dynamic magnetic fields in a high beta plasma, magnetic turbulence, plasma dynamics and energy transport. First, the formation of magnetic neutral sheets, tearing and island coalescence are shown. Nonstationary magnetic fluctuations are statistically evaluated displaying the correlation tensor in the #betta#-k domain for mode identification. Then, the plasma properties are analyzed with particular emphasis on transport processes. Although the classical fluid flow across the separatrix can be observed, the fluctuation processes strongly modify the plasma dynamics. Direct measurements of the fluid force density and ion acceleration indicate the presence of an anomalous scattering process characterized by an effective scattering tensor. Turbulence also enhances the plasma resistivity by one to two orders of magnitude. Measurements of the three-dimensional electron distribution function using a novel energy analyzer exhibit the formation of runaway electrons in the current sheet. Associated micro-instabilities are observed. Finally, a macroscopic disruptive instability of the current sheet is observed. Excess magnetic field energy is converted at a double layer into particle kinetic energy and randomized through beam-plasma instabilities. These laboratory results are compared with related observations in space and fusion plasmas. (Auth.)

  7. Field and In-Lab Determination of Ca[superscript 2+] in Seawater

    Science.gov (United States)

    Stoodley, Robin; Nun~ez, Jose R. Rodriguez; Bartz, Tessa

    2014-01-01

    Portions of classic undergraduate quantitative analysis experiments in complexiometric titration and potentiometry are combined with a field-sampling experience to create a two period (2 × 3 h) comparison-based experiment for second-year students. A multifunctional chemical analysis device is used with calcium ion-selective electrode for field…

  8. Using Field Experiments to Evaluate the Impact of Financial Planning and Counseling Interventions

    Science.gov (United States)

    Collins, J. Michael

    2017-01-01

    Field experiments, which are a powerful research technique, are common in some fields, but they have not been widely used in studying the effect of financial and counseling planning interventions. Financial services can benefit from the expanded use of field experiments to explore potential causal mechanisms for the effects of financial planning…

  9. Field-reversal experiments in the mirror fusion test facility (MFTF)

    International Nuclear Information System (INIS)

    Shearer, J.W.; Condit, W.C.

    1977-01-01

    Detailed consideration of several aspects of a field-reversal experiment was begun in the Mirror Fusion Test Facility (MFTF): Model calculations have provided some plausible parameters for a field-reversed deuterium plasma in the MFTF, and a buildup calculation indicates that the MFTF neutral-beam system is marginally sufficient to achieve field reversal by neutral injection alone. However, the many uncertainties indicate the need for further research and development on alternate buildup methods. A discussion of experimental objectives is presented and important diagnostics are listed. The range of parameter space accessible with the MFTF magnet design is explored, and we find that with proper aiming of the neutral beams, meaningful experiments can be performed to advance toward these objectives. Finally, it is pointed out that if we achieve enhanced n tau confinement by means of field reversal, then quasi-steady-state operation of MFTF is conceivable

  10. Virtual navigation performance: the relationship to field of view and prior video gaming experience.

    Science.gov (United States)

    Richardson, Anthony E; Collaer, Marcia L

    2011-04-01

    Two experiments examined whether learning a virtual environment was influenced by field of view and how it related to prior video gaming experience. In the first experiment, participants (42 men, 39 women; M age = 19.5 yr., SD = 1.8) performed worse on a spatial orientation task displayed with a narrow field of view in comparison to medium and wide field-of-view displays. Counter to initial hypotheses, wide field-of-view displays did not improve performance over medium displays, and this was replicated in a second experiment (30 men, 30 women; M age = 20.4 yr., SD = 1.9) presenting a more complex learning environment. Self-reported video gaming experience correlated with several spatial tasks: virtual environment pointing and tests of Judgment of Line Angle and Position, mental rotation, and Useful Field of View (with correlations between .31 and .45). When prior video gaming experience was included as a covariate, sex differences in spatial tasks disappeared.

  11. A stochastic phase-field model determined from molecular dynamics

    KAUST Repository

    von Schwerin, Erik

    2010-03-17

    The dynamics of dendritic growth of a crystal in an undercooled melt is determined by macroscopic diffusion-convection of heat and by capillary forces acting on the nanometer scale of the solid-liquid interface width. Its modelling is useful for instance in processing techniques based on casting. The phase-field method is widely used to study evolution of such microstructural phase transformations on a continuum level; it couples the energy equation to a phenomenological Allen-Cahn/Ginzburg-Landau equation modelling the dynamics of an order parameter determining the solid and liquid phases, including also stochastic fluctuations to obtain the qualitatively correct result of dendritic side branching. This work presents a method to determine stochastic phase-field models from atomistic formulations by coarse-graining molecular dynamics. It has three steps: (1) a precise quantitative atomistic definition of the phase-field variable, based on the local potential energy; (2) derivation of its coarse-grained dynamics model, from microscopic Smoluchowski molecular dynamics (that is Brownian or over damped Langevin dynamics); and (3) numerical computation of the coarse-grained model functions. The coarse-grained model approximates Gibbs ensemble averages of the atomistic phase-field, by choosing coarse-grained drift and diffusion functions that minimize the approximation error of observables in this ensemble average. © EDP Sciences, SMAI, 2010.

  12. A stochastic phase-field model determined from molecular dynamics

    KAUST Repository

    von Schwerin, Erik; Szepessy, Anders

    2010-01-01

    The dynamics of dendritic growth of a crystal in an undercooled melt is determined by macroscopic diffusion-convection of heat and by capillary forces acting on the nanometer scale of the solid-liquid interface width. Its modelling is useful for instance in processing techniques based on casting. The phase-field method is widely used to study evolution of such microstructural phase transformations on a continuum level; it couples the energy equation to a phenomenological Allen-Cahn/Ginzburg-Landau equation modelling the dynamics of an order parameter determining the solid and liquid phases, including also stochastic fluctuations to obtain the qualitatively correct result of dendritic side branching. This work presents a method to determine stochastic phase-field models from atomistic formulations by coarse-graining molecular dynamics. It has three steps: (1) a precise quantitative atomistic definition of the phase-field variable, based on the local potential energy; (2) derivation of its coarse-grained dynamics model, from microscopic Smoluchowski molecular dynamics (that is Brownian or over damped Langevin dynamics); and (3) numerical computation of the coarse-grained model functions. The coarse-grained model approximates Gibbs ensemble averages of the atomistic phase-field, by choosing coarse-grained drift and diffusion functions that minimize the approximation error of observables in this ensemble average. © EDP Sciences, SMAI, 2010.

  13. An Experiment of GMPLS-Based Dispersion Compensation Control over In-Field Fibers

    Science.gov (United States)

    Seno, Shoichiro; Horiuchi, Eiichi; Yoshida, Sota; Sugihara, Takashi; Onohara, Kiyoshi; Kamei, Misato; Baba, Yoshimasa; Kubo, Kazuo; Mizuochi, Takashi

    As ROADMs (Reconfigurable Optical Add/Drop Multiplexers) are becoming widely used in metro/core networks, distributed control of wavelength paths by extended GMPLS (Generalized MultiProtocol Label Switching) protocols has attracted much attention. For the automatic establishment of an arbitrary wavelength path satisfying dynamic traffic demands over a ROADM or WXC (Wavelength Cross Connect)-based network, precise determination of chromatic dispersion over the path and optimized assignment of dispersion compensation capabilities at related nodes are essential. This paper reports an experiment over in-field fibers where GMPLS-based control was applied for the automatic discovery of chromatic dispersion, path computation, and wavelength path establishment with dynamic adjustment of variable dispersion compensation. The GMPLS-based control scheme, which the authors called GMPLS-Plus, extended GMPLS's distributed control architecture with attributes for automatic discovery, advertisement, and signaling of chromatic dispersion. In this experiment, wavelength paths with distances of 24km and 360km were successfully established and error-free data transmission was verified. The experiment also confirmed path restoration with dynamic compensation adjustment upon fiber failure.

  14. Vegetation Water Content Mapping in a Diverse Agricultural Landscape: National Airborne Field Experiment 2006

    Science.gov (United States)

    Cosh, Michael H.; Jing Tao; Jackson, Thomas J.; McKee, Lynn; O'Neill, Peggy

    2011-01-01

    Mapping land cover and vegetation characteristics on a regional scale is critical to soil moisture retrieval using microwave remote sensing. In aircraft-based experiments such as the National Airborne Field Experiment 2006 (NAFE 06), it is challenging to provide accurate high resolution vegetation information, especially on a daily basis. A technique proposed in previous studies was adapted here to the heterogenous conditions encountered in NAFE 06, which included a hydrologically complex landscape consisting of both irrigated and dryland agriculture. Using field vegetation sampling and ground-based reflectance measurements, the knowledge base for relating the Normalized Difference Water Index (NDWI) and the vegetation water content was extended to a greater diversity of agricultural crops, which included dryland and irrigated wheat, alfalfa, and canola. Critical to the generation of vegetation water content maps, the land cover for this region was determined from satellite visible/infrared imagery and ground surveys with an accuracy of 95.5% and a kappa coefficient of 0.95. The vegetation water content was estimated with a root mean square error of 0.33 kg/sq m. The results of this investigation contribute to a more robust database of global vegetation water content observations and demonstrate that the approach can be applied with high accuracy. Keywords: Vegetation, field experimentation, thematic mapper, NDWI, agriculture.

  15. Spacecraft attitude determination using the earth's magnetic field

    Science.gov (United States)

    Simpson, David G.

    1989-01-01

    A method is presented by which the attitude of a low-Earth orbiting spacecraft may be determined using a vector magnetometer, a digital Sun sensor, and a mathematical model of the Earth's magnetic field. The method is currently being implemented for the Solar Maximum Mission spacecraft (as a backup for the failing star trackers) as a way to determine roll gyro drift.

  16. Using Field Experiments to Change the Template of How We Teach Economics

    Science.gov (United States)

    List, John A.

    2014-01-01

    In this article, the author explains why field experiments can improve what we teach and how we teach economics. Economists no longer operate as passive observers of economic phenomena. Instead, they participate actively in the research process by collecting data from field experiments to investigate the economics of everyday life. This change can…

  17. Rocket to Creativity: A Field Experience in Problem-Based and Project-Based Learning

    Directory of Open Access Journals (Sweden)

    Sharon F. Dole

    2016-11-01

    Full Text Available The purpose of this article is to examine the impact of a field experience in problem-based (PBL and project-based learning (PjBL on pre-service and in-service teachers’ conceptions of experiential learning. In our study, participants had been enrolled in a hybrid class that included an online component in which they learned about PBL and PjBL and an experiential component in which they facilitated PBL and PjBL with children in grades 1-9 during a one-week field experience on a university campus. The goal of the field experience is for teachers to change their practice from didactic to inquiry and to promote critical and creative thinking in their students. We used a case study method that involved data derived from six different sources: online structured interviews, follow-up telephone interviews, discussion board posts, reflections, course feedback, and observations. The main theme that emerged from the data analysis was the critical role the field experience played in applying theory to practice. Sub-themes included understanding the process of implementing PBL and PjBL, mastering the logistics of PBL and PjBL, becoming facilitators, and collaborating with partners. Results showed that the field experience gave the teachers the “courage” to experiment with a student-centered methodology.

  18. Porous media experience applicable to field evaluation for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Gutknecht, P.J.

    1980-06-01

    A survey is presented of porous media field experience that may aid in the development of a compressed air energy storage field demonstration. Work done at PNL and experience of other groups and related industries is reviewed. An overall view of porous media experience in the underground storage of fluids is presented. CAES experience consists of site evaluation and selection processes used by groups in California, Kansas, and Indiana. Reservoir design and field evaluation of example sites are reported. The studies raised questions about compatibility with depleted oil and gas reservoirs, storage space rights, and compressed air regulations. Related experience embraces technologies of natural gas, thermal energy, and geothermal and hydrogen storage. Natural gas storage technology lends the most toward compressed air storage development, keeping in mind the respective differences between stored fluids, physical conditions, and cycling frequencies. Both fluids are injected under pressure into an aquifer to form a storage bubble confined between a suitable caprock structure and partially displaced ground water. State-of-the-art information is summarized as the necessary foundation material for field planning. Preliminary design criteria are given as recommendations for basic reservoir characteristics. These include geometric dimensions and storage matrix properties such as permeability. Suggested ranges are given for injection air temperature and reservoir pressure. The second step in developmental research is numerical modeling. Results have aided preliminary design by analyzing injection effects upon reservoir pressure, temperature and humidity profiles. Results are reported from laboratory experiments on candidate sandstones and caprocks. Conclusions are drawn, but further verification must be done in the field.

  19. Magnetic Field Monitoring in the SNS and LANL Neutron EDM Experiments

    Science.gov (United States)

    Aleksandrova, Alina; SNS nEDM Collaboration; LANL nEDM Collaboration

    2017-09-01

    The SNS neutron EDM experiment requires the ability to precisely control and monitor the magnetic field inside of the fiducial volume. However, it is not always practical (or even possible) to measure the field within the region of interest directly. To remedy this issue, we have designed a field monitoring system that will allow us to reconstruct the field inside of the fiducial volume using noninvasive measurements of the field components at discrete locations external to this volume. A prototype probe array (consisting of 12 single-axis fluxgate magnetometer sensors) was used to monitor the magnetic field within the fiducial volume of an in-house magnetic testing apparatus. In this talk, the design and results of this test will be presented, and the possible implementation of this field monitoring method may have in the room temperature LANL neutron EDM experiment will be discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-SC-0014622.

  20. Operational experience gained from the Central Brae subsea field

    International Nuclear Information System (INIS)

    Sapp, S.J.; Gomersall, S.D.

    1994-01-01

    The size of the field discoveries made in the North Sea in recent years has declined dramatically. With the low oil price many small fields are not viable stand alone developments. The North Sea has a large, well developed infrastructure of production facilities and pipelines. With many platforms now operating below optimum production rate, subsea tieback of these small fields utilizing the available processing capacity is the most economically attractive means of development. This paper presents a history of such a field development. The Central Brae field is located within the Brae complex of fields, 155 miles north east of Aberdeen, and has been developed by means of a subsea facility tied back to the Brae Alpha platform. A great deal of experience has been gained through the field development, not only in subsea operations but also in completion and template design and operating philosophy

  1. Field experiment determinations of distribution coefficients of actinide elements in alkaline lake environments

    International Nuclear Information System (INIS)

    Simpson, H.J.; Trier, R.M.; Li, Y.H.; Anderson, R.F.

    1984-01-01

    Radionuclide concentrations of a number of elements (Am, Pu, U, Pa, Th, Ac, Ra, Po, Pb, Cs, and Sr) have been measured in the water and sediments of a group of alkaline lakes in the western USA. These data demonstrate greatly enhanced soluble phase concentrations of elements with oxidation states of III, IV, V, and VI as the result of carbonate complexing. Dissolved concentrations of isotopes of U, Pa, and Th in a lake with pH = 10 and a total inorganic carbon concentration of 4 x 10 -1 moles/1 were greater than those in sea water (pH = 8, ΣCO 2 = 2 x 10 -3 moles/1) by order of magnitude for 233 U, 238 U (--10 2 ), 231 Pa, 228 Th, 230 Th (--10 3 ) and 22 Th (--10 5 ). Concentrations of fallout /sup 239,240/Pu in the more alkaline lakes were equivalent to effective distribution coefficients of --10 3 , about a factor of 10 2 lower than in most other natural lakes, rivers, estuaries and coastal marine waters. Measurements of radionuclides in natural systems are essential for assessment of the likely fate of radionuclides which may be released from high level waste repositories to ground water. Laboratory-scale experiments using tracer additions of radionuclides to mixtures of water and sediment yielded distribution coefficients which were significantly different from those derived from field measurements (10 1 -10 2 lower for Po and Pu). Order of magnitude calculations from thermodynamic data of expected maximum U and Th concentrations, limited by pure phase solubilities, suggest that carbonate complexing can enhance solubility by many orders of magnitude in natural waters, even at relatively low carbonate ion concentrations

  2. Predictable weathering of puparial hydrocarbons of necrophagous flies for determining the postmortem interval: a field experiment using Chrysomya rufifacies.

    Science.gov (United States)

    Zhu, Guang-Hui; Jia, Zheng-Jun; Yu, Xiao-Jun; Wu, Ku-Sheng; Chen, Lu-Shi; Lv, Jun-Yao; Eric Benbow, M

    2017-05-01

    Preadult development of necrophagous flies is commonly recognized as an accurate method for estimating the minimum postmortem interval (PMImin). However, once the PMImin exceeds the duration of preadult development, the method is less accurate. Recently, fly puparial hydrocarbons were found to significantly change with weathering time in the field, indicating their potential use for PMImin estimates. However, additional studies are required to demonstrate how the weathering varies among species. In this study, the puparia of Chrysomya rufifacies were placed in the field to experience natural weathering to characterize hydrocarbon composition change over time. We found that weathering of the puparial hydrocarbons was regular and highly predictable in the field. For most of the hydrocarbons, the abundance decreased significantly and could be modeled using a modified exponent function. In addition, the weathering rate was significantly correlated with the hydrocarbon classes. The weathering rate of 2-methyl alkanes was significantly lower than that of alkenes and internal methyl alkanes, and alkenes were higher than the other two classes. For mono-methyl alkanes, the rate was significantly and positively associated with carbon chain length and branch position. These results indicate that puparial hydrocarbon weathering is highly predictable and can be used for estimating long-term PMImin.

  3. Do non-monetary prices target the poor? Evidence from a field experiment in India

    OpenAIRE

    Hoffmann, Bridget

    2016-01-01

    This paper uses willingness to pay (WTP) data from a field experiment in Hyderabad, India in 2013 to determine whether non-monetary prices better target health products to the poor than monetary prices. Monetary WTP is increasing in income and non-monetary WTP is weakly decreasing in income. Household fixed effects in a pooled sample of monetary WTP and non-monetary WTP are used to compare the correlation of income and WTP across price types. It is found that non-monetary WTP falls relative t...

  4. EPIC Calibration/Validation Experiment Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Steven E [National Severe Storm Laboratory/NOAA; Chilson, Phillip [University of Oklahoma; Argrow, Brian [University of Colorado

    2017-03-15

    A field exercise involving several different kinds of Unmanned Aerial Systems (UAS) and supporting instrumentation systems provided by DOE/ARM and NOAA/NSSL was conducted at the ARM SGP site in Lamont, Oklahoma on 29-30 October 2016. This campaign was part of a larger National Oceanic and Atmospheric Administration (NOAA) UAS Program Office program awarded to the National Severe Storms Laboratory (NSSL). named Environmental Profiling and Initiation of Convection (EPIC). The EPIC Field Campaign (Test and Calibration/Validation) proposed to ARM was a test or “dry-run” for a follow-up campaign to be requested for spring/summer 2017. The EPIC project addresses NOAA’s objective to “evaluate options for UAS profiling of the lower atmosphere with applications for severe weather.” The project goal is to demonstrate that fixed-wing and rotary-wing small UAS have the combined potential to provide a unique observing system capable of providing detailed profiles of temperature, moisture, and winds within the atmospheric boundary layer (ABL) to help determine the potential for severe weather development. Specific project objectives are: 1) to develop small UAS capable of acquiring needed wind and thermodynamic profiles and transects of the ABL using one fixed-wing UAS operating in tandem with two different fixed rotary-wing UAS pairs; 2) adapt and test miniaturized, high-precision, and fast-response atmospheric sensors with high accuracy in strong winds characteristic of the pre-convective ABL in Oklahoma; 3) conduct targeted short-duration experiments at the ARM Southern Great Plains site in northern Oklahoma concurrently with a second site to be chosen in “real-time” from the Oklahoma Mesonet in coordination with the (National Weather Service (NWS)-Norman Forecast Office; and 4) gain valuable experience in pursuit of NOAA’s goals for determining the value of airborne, mobile observing systems for monitoring rapidly evolving high-impact severe weather

  5. Semi-empirical equivalent field method for dose determination in midline block fields for cobalt - 60 beam

    International Nuclear Information System (INIS)

    Tagoe, S.N.A.; Nani, E.K.; Yarney, J.; Edusa, C.; Quayson-Sackey, K.; Nyamadi, K.M.; Sasu, E.

    2012-01-01

    For teletherapy treatment time calculations, midline block fields are resolved into two fields, but neglecting scattering from other fields, the effective equivalent square field size of the midline block is assumed to the resultant field. Such approach is underestimation, and may be detrimental in achieving the recommended uncertainty of ± 5 % for patient's radiation dose delivery. By comparison, the deviations of effective equivalent square field sizes by calculations and experiments were within 13.2 % for cobalt 60 beams of GWGP80 cobalt 60 teletherapy. Therefore, a modified method incorporating the scatter contributions was adopted to estimate the effective equivalent square field size for midline block field. The measured outputs of radiation beams with the block were compared with outputs of square fields without the blocks (only the block tray) at depths of 5 and 10 cm for the teletherapy machine employing isocentric technique, and the accuracy was within ± 3 % for the cobalt 60 beams. (au)

  6. Local diffusion coefficient determination: Mediterranean Sea experiments

    International Nuclear Information System (INIS)

    Bacciola, D.; Borghini, M.; Cannarsa, S.

    1993-10-01

    The Mediterranean is a semi/enclosed basin characterized by the presence of channels and straits influencing the circulation, temperature and salinity fields. The tides generally have amplitudes of the order of 10 cm and velocities of few cm/s. Conversely, the wind forced circulation is very strong and can assume velocity values of 1 m/s at the sea surface. The temperature and salinity fields have a high temporal and spatial variability, because of many mixing processes existing in the sea. For example, the waters coming from the Provencal basin meet those waters coming from the Tyrrhenian Sea in the eastern Ligurian Sea, creating meanders and eddies. Local runoff influences significantly the coastal circulation. This paper describes diffusion experiments carried out in this complex environment. The experimental apparatus for the detection of the fluorescine released at sea was composed by two Turner mod. 450 fluorometres. During the experiments, temperature and salinity vertical profiles were measured by using a CTD; meteorological data were acquired on a dinghy. The positioning was obtained by means of a Motorola system, having a precision of about 1 meter. The experiments were carried out under different stratification and wind conditions. From data analysis it was found that the horizontal diffusion coefficient does not depend on time or boundary conditions. The role of stratification is important with regard to vertical displacement of the dye. However, its role with regard to vertical diffusion cannot be assessed with the actual experimental apparatus

  7. Conceptual design for an air core 2 meg-amp reversed field experiment

    International Nuclear Information System (INIS)

    Hammer, C.F.

    1983-01-01

    The Los Alamos CTR Division is involved in the conceptual design of a next phase Reversed Field Pinch experiment. The paper will discuss, in general, some of the physics questions that the experiment will address. Also in more detail it will discuss the engineering parameters and the possible hardware design solutions. The experiment is designed to produce a plasma current of about 2 MA which can be sustained for about 200 ms. The electrical energy for the system is provided by a large motor generator set. An inductive energy store is used to drive the magnetizing and poloidal field windings. A capacitor bank provides the energy for the toroidal field windings. The current in both circuits is maintained by using SCR controlled transformer rectifiers

  8. Conceptual design for an AIR CORE 2 MEG-AMP Reversed field experiment

    International Nuclear Information System (INIS)

    Hammer, C.F.

    1983-01-01

    The Los Alamos CTR Division is involved in the conceptual design of a next phase Reversed Field Pinch experiment. The paper will discuss, in general, some of the physics questions that the experiment will address. Also in more detail it will discuss the engineering parameters and the possible hardware design solutions. The experiment is designed to produce a plasma current of about 2 MA which can be sustained for about 200 ms. The electrical energy for the system is provided by a large motor generator set. An inductive energy store is used to drive the magnetizing and poloidal field windings. A capacitor bank provides the energy for the toroidal field windings. The current in both circuits is maintained by using SCR controlled transformer rectifiers

  9. Towards an improved determination of Earth’s lithospheric field from satellite observations

    DEFF Research Database (Denmark)

    Kotsiaros, Stavros; Olsen, Nils; Finlay, Chris

    Perhaps one of the biggest difficulties in modelling the Earth’s lithospheric magnetic field is the separation of contributions from sources of internal and external origin. In particular, the determination of smaller-scale lithospheric magnetic field features is problematic because the lithosphe......Perhaps one of the biggest difficulties in modelling the Earth’s lithospheric magnetic field is the separation of contributions from sources of internal and external origin. In particular, the determination of smaller-scale lithospheric magnetic field features is problematic because...

  10. Hessian matrix approach for determining error field sensitivity to coil deviations

    Science.gov (United States)

    Zhu, Caoxiang; Hudson, Stuart R.; Lazerson, Samuel A.; Song, Yuntao; Wan, Yuanxi

    2018-05-01

    The presence of error fields has been shown to degrade plasma confinement and drive instabilities. Error fields can arise from many sources, but are predominantly attributed to deviations in the coil geometry. In this paper, we introduce a Hessian matrix approach for determining error field sensitivity to coil deviations. A primary cost function used for designing stellarator coils, the surface integral of normalized normal field errors, was adopted to evaluate the deviation of the generated magnetic field from the desired magnetic field. The FOCUS code (Zhu et al 2018 Nucl. Fusion 58 016008) is utilized to provide fast and accurate calculations of the Hessian. The sensitivities of error fields to coil displacements are then determined by the eigenvalues of the Hessian matrix. A proof-of-principle example is given on a CNT-like configuration. We anticipate that this new method could provide information to avoid dominant coil misalignments and simplify coil designs for stellarators.

  11. Exploring International Multicultural Field Experiences in Educational Technology

    Science.gov (United States)

    Wilder, Hilary; Ferris, Sharmila Pixy; An, Heejung

    2010-01-01

    Purpose: The purpose of this paper is to explore an online field experience between technology facilitator candidates in the USA and K-12 teachers in Namibia, to improve candidates' understanding of diversity and equity issues in the successful incorporation of information and communication technologies (ICT) in teaching and learning.…

  12. Community-Based Field Experiences in Teacher Education: Possibilities for a Pedagogical Third Space

    Science.gov (United States)

    Hallman, Heidi L.

    2012-01-01

    The present article discusses the importance of community-based field experiences as a feature of teacher education programs. Through a qualitative case study, prospective teachers' work with homeless youth in an after-school initiative is presented. Framing community-based field experiences in teacher education through "third space" theory, the…

  13. An Integral, Multidisciplinary and Global Geophysical Field Experience for Undergraduates

    Science.gov (United States)

    Vázquez, O.; Carrillo, D. J.; Pérez-Campos, X.

    2007-05-01

    The udergraduate program of Geophysical Engineering at the School of Engineering, of the Univesidad Nacional Autónoma de México (UNAM), went through an update process that concluded in 2006. As part of the program, the student takes three geophysical prospecting courses (gravity and magnetics, electric, electromagnetics, and seismic methods). The older program required a three-week field experience for each course in order to gradute. The new program considers only one extended field experience. This work stresses the importance of international academic exchange, where undergraduate students could participate, such as the Summer of Applied Geophysical Experience (SAGE), and interaction with research programs, such as the MesoAmerican Subduction Experiment (MASE). Also, we propose a scheeme for this activity based on those examples; both of them have in common real geophysical problems, from which students could benefit. Our proposal covers academic and logistic aspects to be taken into account, enhancing the relevance of interaction between other academic institutions, industry, and UNAM, in order to obtain a broader view of geophysics.

  14. Influence of the mode of deformation on recrystallisation behaviour of titanium through experiments, mean field theory and phase field model

    Science.gov (United States)

    Athreya, C. N.; Mukilventhan, A.; Suwas, Satyam; Vedantam, Srikanth; Subramanya Sarma, V.

    2018-04-01

    The influence of the mode of deformation on recrystallisation behaviour of Ti was studied by experiments and modelling. Ti samples were deformed through torsion and rolling to the same equivalent strain of 0.5. The deformed samples were annealed at different temperatures for different time durations and the recrystallisation kinetics were compared. Recrystallisation is found to be faster in the rolled samples compared to the torsion deformed samples. This is attributed to the differences in stored energy and number of nuclei per unit area in the two modes of deformation. Considering decay in stored energy during recrystallisation, the grain boundary mobility was estimated through a mean field model. The activation energy for recrystallisation obtained from experiments matched with the activation energy for grain boundary migration obtained from mobility calculation. A multi-phase field model (with mobility estimated from the mean field model as a constitutive input) was used to simulate the kinetics, microstructure and texture evolution. The recrystallisation kinetics and grain size distributions obtained from experiments matched reasonably well with the phase field simulations. The recrystallisation texture predicted through phase field simulations compares well with experiments though few additional texture components are present in simulations. This is attributed to the anisotropy in grain boundary mobility, which is not accounted for in the present study.

  15. Overview of the Bushland Evapotranspiration and Agricultural Remote sensing EXperiment 2008 (BEAREX08): A field experiment evaluating methods for quantifying ET at multiple scales

    Science.gov (United States)

    Evett, Steven R.; Kustas, William P.; Gowda, Prasanna H.; Anderson, Martha C.; Prueger, John H.; Howell, Terry A.

    2012-12-01

    In 2008, scientists from seven federal and state institutions worked together to investigate temporal and spatial variations of evapotranspiration (ET) and surface energy balance in a semi-arid irrigated and dryland agricultural region of the Southern High Plains in the Texas Panhandle. This Bushland Evapotranspiration and Agricultural Remote sensing EXperiment 2008 (BEAREX08) involved determination of micrometeorological fluxes (surface energy balance) in four weighing lysimeter fields (each 4.7 ha) containing irrigated and dryland cotton and in nearby bare soil, wheat stubble and rangeland fields using nine eddy covariance stations, three large aperture scintillometers, and three Bowen ratio systems. In coordination with satellite overpasses, flux and remote sensing aircraft flew transects over the surrounding fields and region encompassing an area contributing fluxes from 10 to 30 km upwind of the USDA-ARS lysimeter site. Tethered balloon soundings were conducted over the irrigated fields to investigate the effect of advection on local boundary layer development. Local ET was measured using four large weighing lysimeters, while field scale estimates were made by soil water balance with a network of neutron probe profile water sites and from the stationary flux systems. Aircraft and satellite imagery were obtained at different spatial and temporal resolutions. Plot-scale experiments dealt with row orientation and crop height effects on spatial and temporal patterns of soil surface temperature, soil water content, soil heat flux, evaporation from soil in the interrow, plant transpiration and canopy and soil radiation fluxes. The BEAREX08 field experiment was unique in its assessment of ET fluxes over a broad range in spatial scales; comparing direct and indirect methods at local scales with remote sensing based methods and models using aircraft and satellite imagery at local to regional scales, and comparing mass balance-based ET ground truth with eddy covariance

  16. Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

    Science.gov (United States)

    Mykrä, Heikki; Sarremejane, Romain; Laamanen, Tiina; Karjalainen, Satu Maaria; Markkola, Annamari; Lehtinen, Sirkku; Lehosmaa, Kaisa; Muotka, Timo

    2018-04-16

    We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO 3 -N) and phosphate (PO 4 -P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate on average by 14%, but the effect was significant only in naturally acidic streams. Nutrient enrichment also decreased richness and increased compositional variability of fungal communities in naturally acidic streams. Algal biomass increased in both stream types, but algal growth was overall very low. Diatom richness increased in response to nutrient addition by, but only in circumneutral streams. Our results suggest that primary producers and decomposers are differentially affected by nutrient enrichment and that their responses to excess nutrients are context dependent, with a potentially stronger response of detrital processes and fungal communities in naturally acidic streams than in less selective environments.

  17. The electromagnetic bio-field: clinical experiments and interferences.

    Science.gov (United States)

    Burnei, G; Hodorogea, D; Georgescu, I; Gavriliu, Ş; Drăghici, I; Dan, D; Vlad, C; Drăghici, L

    2012-06-12

    One of the most important factors is the technical and scientifically rapid development that is continually modifying the world we live in and polluting it with electromagnetic radiations. A functional and structural influence of magnetic and electromagnetic field on living organisms is presented in the literature by many performed experiments. The notion of bio-field represents the electromagnetic field generated by the bio-structures, not only in their normal physiological activities but also in their pathological states. There is a tight interdependency between the bio-field and the bio-structure, which respects the primary notion of an electromagnetic field given by the Maxwell-Faraday laws, in which, the electromagnetic phenomena are simplified to the field variations. These variations can be expressed in a coherent differential equation system that bounds the field vectors to different space points at different time moments. The living organisms cannot contain electrostatic and magneto-static fields due to the intense activity of the bio-structures. The biochemical reactions that have high rhythms and speeds always impose the electrodynamics character of the biologic field that also corresponds to the stability of the protein molecule that can be explained only through a dynamic way. The existent energy is not considered an exciting agent, and it does not lead to any effects. The parameters of these elementary bio-fields cannot yet be fully known due to technical reasons. The biological structures are very complex ones and undergo continuous dynamical activity. That is why the calculus model should be related to the constant dynamics, nowadays being very difficult to express.

  18. Employee Recognition and Performance: A Field Experiment

    OpenAIRE

    Bradler, Christiane; Dur, Robert; Neckermann, Susanne; Non, Arjan

    2014-01-01

    This discussion paper led to a publication in 'Management Science' . This paper reports the results from a controlled field experiment designed to investigate the causal effect of unannounced, public recognition on employee performance. We hired more than 300 employees to work on a three-hour data-entry task. In a random sample of work groups, workers unexpectedly received recognition after two hours of work. We find that recognition increases subsequent performance substantially, and particu...

  19. Laboratory experiments on the magnetic field and neutral density limits on CIV interaction

    International Nuclear Information System (INIS)

    Axnaes, I.; Brenning, N.

    1990-03-01

    Laboratory experiments are reported which determine the magnetic field and neutral density limit for Critical Ionization Velocity (CIV) interaction in the impact configuration. A combination of microwave interferometry and spectroscopy has been used to measure how the electron energy distribution varies with the neutral density and the magnetic field strength. The efficiency of the CIV process is evaluated in terms of the efficiency factor η of energy transfer to the electron. This efficiency is studied as function of the ratio V A /V 0 between the Alfven velocity and the plasma stream velocity and the ratio ν i /ω gi between the ionization frequency and the ion gyro frequency. With other parameters kept constant, V A /V 0 is proportional to the square root of the magnetic field, while ν i /ω gi is proportional to the neutral density. We have found that these two dimensionless parameters are coupled in such a fashion that a stronger magnetic field can compensate for a lower neutral density. For our strongest magnetic field, corresponding to V A /V 0 = 4, CIV interaction is found to occur for a comparatively low value ν i /ω gi ∼ 0.1. For V A /V 0 = 1, we found a clear absence of CIV interaction even for ν i /ω gi approaching unity. (authors)

  20. Determination of the viscous acoustic field for liquid drop positioning/forcing in an acoustic levitation chamber in microgravity

    Science.gov (United States)

    Lyell, Margaret J.

    1992-01-01

    The development of acoustic levitation systems has provided a technology with which to undertake droplet studies as well as do containerless processing experiments in a microgravity environment. Acoustic levitation chambers utilize radiation pressure forces to position/manipulate the drop. Oscillations can be induced via frequency modulation of the acoustic wave, with the modulated acoustic radiation vector acting as the driving force. To account for tangential as well as radial forcing, it is necessary that the viscous effects be included in the acoustic field. The method of composite expansions is employed in the determination of the acoustic field with viscous effects.

  1. Studies of the Impact of Magnetic Field Uncertainties on Physics Parameters of the Mu2e Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bradascio, Federica [Pisa U.

    2016-01-01

    The Mu2e experiment at Fermilab will search for a signature of charged lepton flavor violation, an effect prohibitively too small to be observed within the Standard Model of particle physics. Therefore, its observation is a signal of new physics. The signature that Mu2e will search for is the ratio of the rate of neutrinoless coherent conversion of muons into electrons in the field of a nucleus, relative to the muon capture rate by the nucleus. The conversion process is an example of charged lepton flavor violation. This experiment aims at a sensitivity of four orders of magnitude higher than previous related experiments. The desired sensitivity implies highly demanding requirements of accuracy in the design and conduct of the experiment. It is therefore important to investigate the tolerance of the experiment to instrumental uncertainties and provide specifications that the design and construction must meet. This is the core of the work reported in this thesis. The design of the experiment is based on three superconducting solenoid magnets. The most important uncertainties in the magnetic field of the solenoids can arise from misalignments of the Transport Solenoid, which transfers the beam from the muon production area to the detector area and eliminates beam-originating backgrounds. In this thesis, the field uncertainties induced by possible misalignments and their impact on the physics parameters of the experiment are examined. The physics parameters include the muon and pion stopping rates and the scattering of beam electrons off the capture target, which determine the signal, intrinsic background and late-arriving background yields, respectively. Additionally, a possible test of the Transport Solenoid alignment with low momentum electrons is examined, as an alternative option to measure its field with conventional probes, which is technically difficult due to mechanical interference. Misalignments of the Transport Solenoid were simulated using standard

  2. Machine Vision System for Characterizing the Electric Field for the 225 Ra EDM Experiment

    Science.gov (United States)

    Sanchez, Andrew

    2017-09-01

    If an atom or fundamental particle possesses an electric dipole moment (EDM), that would imply time-reversal violation. At our current capability, if an EDM is detected in such a particle, that would suggest the discovery of beyond the standard model (BSM) physics. The unique structure of 225 Ra makes its atomic EDM favorable in the BSM search. An upgraded Ra-EDM apparatus will increase experimental sensitivity and the target electric field of 150 kV/cm will more than double the electric field used in previous experiments. To determine the electric field, the potential difference and electrode separation distance must be known. The optical method I have developed is a high-precision, non-invasive technique to measure electrode separation without making contact with the sensitive electrode surfaces. A digital camera utilizes a bi-telecentric lens to reduce parallax error and produce constant magnification throughout the optical system, regardless of object distance. A monochrome LED backlight enhances sharpness of the electrode profile, reducing uncertainty in edge determination and gap width. A program utilizing an edge detection algorithm allows precise, repeatable measurement of the gap width to within 1% and measurement of the relative angle of the electrodes. This work (SAM, Ra EDM) is supported by Michigan State University. This work (REU Program) is supported by U.S. National Science Foundation under Grant Number #1559866.

  3. Model Experiments for the Determination of Airflow in Large Spaces

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    Model experiments are one of the methods used for the determination of airflow in large spaces. This paper will discuss the formation of the governing dimensionless numbers. It is shown that experiments with a reduced scale often will necessitate a fully developed turbulence level of the flow....... Details of the flow from supply openings are very important for the determination of room air distribution. It is in some cases possible to make a simplified supply opening for the model experiment....

  4. Survey of Academic Field Experiences (SAFE): Trainees Report Harassment and Assault

    Science.gov (United States)

    Clancy, Kathryn B. H.; Nelson, Robin G.; Rutherford, Julienne N.; Hinde, Katie

    2014-01-01

    Little is known about the climate of the scientific fieldwork setting as it relates to gendered experiences, sexual harassment, and sexual assault. We conducted an internet-based survey of field scientists (N = 666) to characterize these experiences. Codes of conduct and sexual harassment policies were not regularly encountered by respondents, while harassment and assault were commonly experienced by respondents during trainee career stages. Women trainees were the primary targets; their perpetrators were predominantly senior to them professionally within the research team. Male trainees were more often targeted by their peers at the research site. Few respondents were aware of mechanisms to report incidents; most who did report were unsatisfied with the outcome. These findings suggest that policies emphasizing safety, inclusivity, and collegiality have the potential to improve field experiences of a diversity of researchers, especially during early career stages. These include better awareness of mechanisms for direct and oblique reporting of harassment and assault and, the implementation of productive response mechanisms when such behaviors are reported. Principal investigators are particularly well positioned to influence workplace culture at their field sites. PMID:25028932

  5. Survey of academic field experiences (SAFE: trainees report harassment and assault.

    Directory of Open Access Journals (Sweden)

    Kathryn B H Clancy

    Full Text Available Little is known about the climate of the scientific fieldwork setting as it relates to gendered experiences, sexual harassment, and sexual assault. We conducted an internet-based survey of field scientists (N = 666 to characterize these experiences. Codes of conduct and sexual harassment policies were not regularly encountered by respondents, while harassment and assault were commonly experienced by respondents during trainee career stages. Women trainees were the primary targets; their perpetrators were predominantly senior to them professionally within the research team. Male trainees were more often targeted by their peers at the research site. Few respondents were aware of mechanisms to report incidents; most who did report were unsatisfied with the outcome. These findings suggest that policies emphasizing safety, inclusivity, and collegiality have the potential to improve field experiences of a diversity of researchers, especially during early career stages. These include better awareness of mechanisms for direct and oblique reporting of harassment and assault and, the implementation of productive response mechanisms when such behaviors are reported. Principal investigators are particularly well positioned to influence workplace culture at their field sites.

  6. Survey of academic field experiences (SAFE): trainees report harassment and assault.

    Science.gov (United States)

    Clancy, Kathryn B H; Nelson, Robin G; Rutherford, Julienne N; Hinde, Katie

    2014-01-01

    Little is known about the climate of the scientific fieldwork setting as it relates to gendered experiences, sexual harassment, and sexual assault. We conducted an internet-based survey of field scientists (N = 666) to characterize these experiences. Codes of conduct and sexual harassment policies were not regularly encountered by respondents, while harassment and assault were commonly experienced by respondents during trainee career stages. Women trainees were the primary targets; their perpetrators were predominantly senior to them professionally within the research team. Male trainees were more often targeted by their peers at the research site. Few respondents were aware of mechanisms to report incidents; most who did report were unsatisfied with the outcome. These findings suggest that policies emphasizing safety, inclusivity, and collegiality have the potential to improve field experiences of a diversity of researchers, especially during early career stages. These include better awareness of mechanisms for direct and oblique reporting of harassment and assault and, the implementation of productive response mechanisms when such behaviors are reported. Principal investigators are particularly well positioned to influence workplace culture at their field sites.

  7. Experience-based Learning in Acadia National Park: a Successful, Long-running, Model Field Course

    Science.gov (United States)

    Connaughton, M.

    2015-12-01

    This two-week field course has been offered alternate summers since 2000 in Acadia National Park on Mount Desert Island, Maine and addresses the geological history, physical and biological oceanography and principles of community ecology applicable to terrestrial and/or marine communities of coastal Maine. The course is often transformative and deeply meaningful to the students, many of whom have limited travel experience. The essential components of experience-based learning are well represented in this class with multiple opportunities for abstract conceptualization, active experimentation, concrete hands-on experiences and reflective observation built into the course. Each day begins with a lecture introducing concepts, which are then made concrete though daily field trips (4-8 hours in duration) into the park that include rigorous hiking, some kayaking and one commercial nature cruise. Field trips include hands-on experience with lecture concepts, on-site lessons in field methods, and data collection for independent projects. Each field trip is tied to a specific independent project, which are generated by the instructor, but self-selected by the students. Every student is actively involved in data collection during each field trip, with one student in charge of the collection each day. Daily guided journaling in three parts (scientific, personal and creative) and evening discussions provide ample opportunity for the student to reflect on the scientific content of the course, examine their personal reactions to what they have experienced and to be creative, sharing prior experiences, prior learning and their personalities. The course includes two exams, each following a week of lecture and field experiences. Independent research projects include the production of a manuscript-formatted report complete with statistical analysis of the data and a literature-based discussion of the conclusions. The combination of experiential reinforcement of concepts, abundant

  8. Determination of Turbine Blade Life from Engine Field Data

    Science.gov (United States)

    Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

    2013-01-01

    It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal-mechanical fatigue (TMF) as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) TMF, (2) Oxidation/erosion (O/E), and (3) Other. From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L10 blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to O/E equaled that attributed to TMF. The category that contributed most to blade failure was Other. If there were no blade failures attributed to O/E and TMF, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

  9. Determination of reactor parameters by single rod experiments

    Energy Technology Data Exchange (ETDEWEB)

    Raisic, N; Zdravkovic, Z; Ivkovic, M [Department of Reactor Physics and Dynamics, Boris Kidric Institute of Nuclear Sciences, Vinca, Belgrade (Yugoslavia)

    1969-07-01

    A method is developed for the experimental determination of reactor parameters by using an isolated fuel element. The method is based on the consideration of the fuel element as the source and sink of neutrons when placed in a constant neutron field. By measuring the perturbation of the original field produced by insertion of the test fuel element it was possible to determine the fuel element parameters defined by the heterogeneous reactor theory of Feinberg and Galanin as thermal neutron absorption constant {gamma}, and neutron multiplication constant {eta}. Statistical error for one series of measurement amount to 2% in the values of {eta} and {gamma}. The developed method was intended for the analysis of the nuclear characteristics of the fuel element in the stage of its construction and development for a given reactor system. (author)

  10. The Current Situation of Field Experience in a Five-Year Science Teacher Education Program in Thailand

    Science.gov (United States)

    Faikhamta, Chatree; Jantarakantee, Ekgapoom; Roadrangka, Vantipa

    2011-01-01

    This research explored the current situation in managing the field experience of a five-year science teacher education program in one university in Thailand. A number of methods were used to assess field experience situation: (1) a questionnaire on the perceptions of pre-service science teachers of field experience management; (2) participant…

  11. The role of brand destination experience in determining revisit intention

    DEFF Research Database (Denmark)

    Mattsson, Jan; Barnes, Stuart; Sørensen, Flemming

    Destination branding has developed considerably as a topic area in the last decade with numerous conceptualizations focusing on different aspects of the brand. However, a unified view has not yet emerged. This paper examines destination branding via a new conceptualization, brand destination...... experience, which provides a more holistic and unified view of the brand destination. The research uses a logistic regression model to determine the role of satisfaction and brand experience in determining revisit intentions. The study also examines differences among subgroups and four brand experience sub...

  12. A large scale field experiment in the Amazon basin (LAMBADA/BATERISTA)

    NARCIS (Netherlands)

    Dolman, A.J.; Kabat, P.; Gash, J.H.C.; Noilhan, J.; Jochum, A.M.; Nobre, C.

    1995-01-01

    A description is given of a large-scale field experiment planned in the Amazon basin, aimed at assessing the large-scale balances of energy, water and carbon dioxide. The embedding of this experiment in global change programmes is described, viz. the Biospheric Aspects of the Hydrological Cycle

  13. Entering the Field: Beginning Teachers' Positioning Experiences of the Staffroom

    Science.gov (United States)

    Christensen, Erin; Rossi, Tony; lisahunter; Tinning, Richard

    2018-01-01

    Little is known about beginning teachers' political positioning experiences of the staffroom. This paper employs Bourdieu's conceptual tools of field, habitus and capital to explore beginning health and physical education teachers' positioning experiences and learning in staffrooms, the place in which teachers spend the majority of their…

  14. Experiments to determine the migration potential for water and contaminants in shallow land burial facilities design, emplacement, and preliminary results

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Abeele, W.V.; Burton, B.W.

    1982-01-01

    Leaching and transport of radionuclides by water has been a primary mode of radioactive contamination from low-level radioactive waste disposal facilities. Similarly, the infiltration of water into nonradioactive hazardous waste disposal facilities has resulted in the movement of contaminants out of these disposal facilities. Although there have been many laboratory studies on water movement and contaminant transport, there is a need for more large scale field experiments. Large scale field experiments are necessary to (1) measure hydraulic conductivities on a scale typical of actual shallow land burial facilities and hazardous waste disposal facilities, (2) allow comparisons to be made between full scale and laboratory measurements, (3) verify the applicability of calculational methods for determining unsaturated hydraulic conductivities from water retention curves, and (4) for model validation. Experiments that will provide the information to do this are described in this paper

  15. Infusing Outdoor Field Experiences into the Secondary Biology Curriculum.

    Science.gov (United States)

    Owens, Ginny

    1984-01-01

    To offer students biological field experiences, teachers should use their own basic skills, be enthusiastic motivators, participate in community programs/courses/workshops to acquire additional skills/knowledge for outdoor biological education, plan outdoor excursions with safety considerations in mind, and use available resources for classroom…

  16. Matching time and spatial scales of rapid solidification: dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

    Science.gov (United States)

    Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.; Fattebert, Jean-Luc; McKeown, Joseph T.

    2018-01-01

    A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu-Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid-liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu-Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying from ˜0.1 to ˜0.6 m s-1. After an ‘incubation’ time, the velocity of the planar solid-liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Finally, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid-liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).

  17. Minimizing Environmental Magnetic Field Sources for nEDM

    Science.gov (United States)

    Brinson, Alex; Filippone, Bradley; Slutsky, Simon; Osthelder, Charles

    2017-09-01

    Measurement of the neutron's Electric Dipole Moment (nEDM) could potentially explain the Baryon Asymmetry Problem, and would suggest plausible extensions to the Standard Model. We will attempt to detect the nEDM by measuring the electric-field-dependent neutron precession frequency, which is highly sensitive to magnetic field gradients. In order to produce fields with sufficiently low gradients for our experiment, we eliminate environmental effects by offsetting the ambient field with a Field Compensation System (FCS), then magnetically shielding the reduced field with a Mu-Metal cylinder. We discovered that the strongest environmental effect in our lab came from iron rebar embedded in the floor beneath the proposed experiment location. The large extent and strength of the floor's magnetization made the effect too large to offset with the FCS, forcing us to relocate our apparatus. The floor's magnetic field was mapped with a Hall probe in order to determine the most viable experiment locations. A 3-axis Fluxgate magnetometer was then used to determine the floor field's drop-off and shape at these locations, and a final apparatus position was determined which minimized the floor's effect such that it could be effectively offset and shielded by our experiment. Caltech SFP Office.

  18. Attention discrimination: theory and field experiments with monitoring information acquisition

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Vojtěch; Bauer, Michal; Chytilová, Julie; Matějka, Filip

    2016-01-01

    Roč. 106, č. 6 (2016), s. 1437-1475 ISSN 0002-8282 Institutional support: RVO:67985998 Keywords : inattention * discrimination * field experiment Subject RIV: AH - Economics Impact factor: 4.026, year: 2016

  19. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments

    Science.gov (United States)

    Vélez, María Alejandra; Trujillo, Carlos Andres; Moros, Lina; Forero, Clemente

    2016-01-01

    Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism positively. In Study 2, carried out three years after Study 1, we repeated the initial design with additional measures of victimization. Our goal was to relate subjective insecurity with actual victimization. The findings of Study 2 support the initial results, and are robust and consistent for cooperative behavior and trust when including victimization as a mediator. Different indicators of victimization are positively correlated with subjective insecurity and an aggregate index of victimization has a negative effect on cooperation but exerts a positive influence on trust. PMID:27472437

  20. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments.

    Directory of Open Access Journals (Sweden)

    María Alejandra Vélez

    Full Text Available Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism positively. In Study 2, carried out three years after Study 1, we repeated the initial design with additional measures of victimization. Our goal was to relate subjective insecurity with actual victimization. The findings of Study 2 support the initial results, and are robust and consistent for cooperative behavior and trust when including victimization as a mediator. Different indicators of victimization are positively correlated with subjective insecurity and an aggregate index of victimization has a negative effect on cooperation but exerts a positive influence on trust.

  1. Prosocial Behavior and Subjective Insecurity in Violent Contexts: Field Experiments.

    Science.gov (United States)

    Vélez, María Alejandra; Trujillo, Carlos Andres; Moros, Lina; Forero, Clemente

    2016-01-01

    Subjective insecurity is a key determinant of different forms of prosocial behavior. In Study 1, we used field experiments with farmers in Colombian villages exposed to different levels of violence to investigate how individual perceptions of insecurity affect cooperation, trust, reciprocity and altruism. To do so, we developed a cognitive-affective measure of subjective insecurity. We found that subjective insecurity has a negative effect on cooperation but influences trust and altruism positively. In Study 2, carried out three years after Study 1, we repeated the initial design with additional measures of victimization. Our goal was to relate subjective insecurity with actual victimization. The findings of Study 2 support the initial results, and are robust and consistent for cooperative behavior and trust when including victimization as a mediator. Different indicators of victimization are positively correlated with subjective insecurity and an aggregate index of victimization has a negative effect on cooperation but exerts a positive influence on trust.

  2. Subsampled Numerical Experiments as a Guide for Field Deployment of Thermistor Chains

    Science.gov (United States)

    Shaw, Justin; Stastna, Marek

    2017-11-01

    Thermistor chains are a standard tool for recording temperature profiles in geophysical flows. Density values can be inferred from readings and the resulting density field analyzed for the passage of internal waves, Kelvin-Helmholtz billows, and other dynamic events. The number and spacing of the thermistors, both on and between chains, determines which events can be identified in the dataset. We examine the effect of changing these variables by subsampling a set of numerical experiments to simulate thermistor chain locations. A pseudo spectral method was used to solve the incompressible Navier-Stokes equations under the Boussinesq approximation. The resulting flows are a set of high resolution seiches where the depth was held constant across experiments, and the length was varied. Sampling a known, commonly occurring flow with relatively simple geometry allows for a clear analysis of the effects of thermistor placement in the capture of dynamic events. We will discuss three dimensional deployment strategies, as well as EOF and DMD analyses if there is time. Funded by a Grant from the National Sciences and Engineering Research Council of Canada.

  3. Experiments to determine the migration potential for water and contaminants in shallow land-burial facilities: design, emplacement, and preliminary results

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Abeele, W.V.; Burton, B.W.

    1982-01-01

    Although there have been many laboratory studies on water movement and contaminant transport, there is a need for more large scale field experiments. Large scale field experiments are necessary to (1) measure hydraulic conductivities on a scale typical of actual shallow land burial facilities and hazardous waste disposal facilities, (2) allow comparisons to be made between full scale and laboratory measurements, (3) verify the applicability of calculational methods for determining unsaturated hydraulic conductivities from water retention curves, and (4) for model validation. Experiments that will provide the information to do this are described in this paper. The results of these experiments will have applications for both the shallow land burial of low level radioactive wastes and the disposal of hazardous chemical wastes. These experiments will provide results that can be used in model verification for system performance. This type of data on experiments done at this scale has not been available, and are necessary for validating unsaturated transport models and other models used to predict long term system performance. Even though these experiments are done on crushed Bandelier Tuff, most models use physical properties of the backfill material such as density, porosity, and water retention curves. For this reason, once the models are validated in these experiments, they can be applied with confidence to other materials as long as the material properties are well characterized. In addition, from known water movement rates, calculable from the results of these experiments, requirements for other parts of the system such as liners, water diversion systems, and system cap requirements can be determined. Lastly, the results of these experiments and their use in model verification will provide a sound scientific basis on which to base decisions on system requirements and system design

  4. A large scale field experiment in the Amazon Basin (Lambada/Bateristca)

    Energy Technology Data Exchange (ETDEWEB)

    Dolman, A.J.; Kabat, P.; Gash, J.H.C.; Noilhan, J.; Jochum, A.M.; Nobre, C. [Winand Staring Centre, Wageningen (Netherlands)

    1994-12-31

    A description is given of a large scale field experiment planned in the Amazon Basin, aiming to assess the large scale balances of energy, water and CO{sub 2}. The background for this experiment, the embedding in global change programmes of IGBP/BAHC and WCRP/GEWEX is described. A proposal by four European groups aimed at designing the experiment with the help of mesoscale models is described and a possible European input to this experiment is suggested. 24 refs., 1 app.

  5. Cs-137 soil to plant transfer factors derived from pot experiments and field studies

    International Nuclear Information System (INIS)

    Horak, O.; Gerzabek, M.H.; Mueck, K.

    1989-11-01

    Soil to plant transfer factors (TF) of 137 Cs for different crop plants were determined in pot experiments, in outdoor experiments with plastic containers of 50 l volume, and in field studies. In all cases the soil contamination with 137 Cs resulted from fallout after the Chernobyl reactor accident. Mean TF derived for outdoor plants on a fresh weight basis, ranged from 0,0017 (leaf vegetables) to 0,059 (rye straw) and showed characteristic differences depending on plant part and species. Generally, for fruits and potato tubers a lower TF was found than for vegetative plant parts. Moreover, the data were compared with those from former experiments, carried out before the Chernobyl accident. There is a good agreement for cereals (with exception of rye) fruit vegetables and fodder crops, while actual TF are substantially lower for potatoes, leaf and root vegetables, but higher for rye. A significant negative correlation was observed between the TF and the soil activity concentrations for 137 Cs. In container experiments the TF were found to be influenced mainly by the clay content of the soil. 11 refs., 2 figs., 2 tabs. (Authors)

  6. On the field determination of effective porosity

    International Nuclear Information System (INIS)

    Javandel, I.

    1989-03-01

    Effective porosity of geologic materials is a very important parameter for estimating groundwater travel time and modeling contaminant transport in hydrologic systems. Determination of a representative effective porosity for nonideal systems is a problem still challenging hydrogeologists. In this paper, some of the conventional field geophysical and hydrological methods for estimating effective porosity of geologic materials are reviewed. The limitations and uncertainties associated with each method are discussed. 30 refs., 8 figs

  7. A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Holley, A. T.; Pattie, R. W.; Young, A. R. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Broussard, L. J. [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Davis, J. L.; Ito, T. M.; Lyles, J. T. M.; Makela, M.; Morris, C. L.; Mortensen, R.; Saunders, A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hickerson, K.; Mendenhall, M. P. [W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125 (United States); Liu, C.-Y. [Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States); Mammei, R. R. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States); Rios, R. [Department of Physics, Idaho State University, Pocatello, Idaho 83209 (United States)

    2012-07-15

    The UCNA collaboration is making a precision measurement of the {beta} asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during the 2007 run cycle of the Los Alamos Neutron Science Center's 800 MeV proton accelerator is detailed. These studies determined the flipping efficiency of the device, averaged over the UCN spectrum present at the location of the spin flipper, to be {epsilon}=0.9985(4).

  8. Experiments on plasma turbulence induced by strong, steady electric fields

    International Nuclear Information System (INIS)

    Hamberger, S.M.

    1975-01-01

    The author discusses the effect of applying a strong electric field to collisionless plasma. In particular are compared what some ideas and prejudices lead one to expect to happen, what computer simulation experiments tell one ought to happen, and what actually does happen in two laboratory experiments which have been designed to allow the relevant instability and turbulent processes to occur unobstructed and which have been studied in sufficient detail. (Auth.)

  9. Self-Determination and Goal Orientation in Track and Field

    OpenAIRE

    Chin, Ngien-Siong; Khoo, Selina; Low, Wah-Yun

    2012-01-01

    This study investigated gender, age group and locality differences in adolescent athletes? self-determination motivation and goal orientations in track and field. It also examined the relationship between the self-determination theory and achievement goal theory. A total of 632 (349 boys, 283 girls) adolescent athletes (aged 13?18 years) completed the Sports Motivation Scale and Task and Ego Orientation in Sport Questionnaire. Results indicated significant differences between gender on intrin...

  10. Global Lunar Gravity Field Determination Using Historical and Recent Tracking Data in Preparation for SELENE

    Science.gov (United States)

    Goossens, S.; Matsumoto, K.; Namiki, N.; Hanada, H.; Iwata, T.; Tsuruta, S.; Kawano, N.; Sasaki, S.

    2006-12-01

    In the near future, a number of satellite missions are planned to be launched to the Moon. These missions include initiatives by China, India, the USA, as well as the Japanese SELENE mission. These missions will gather a wealth of lunar data which will improve the knowledge of the Moon. One of the main topics to be addressed will be the lunar gravity field. Especially SELENE will contribute to improving the knowledge of the gravity field, by applying 4-way Doppler tracking between the main satellite and a relay satellite, and by applying a separate differential VLBI experiment. These will improve the determination of the global gravity field, especially over the far side and at the lower degrees (mostly for degrees lower than 30), as is shown by extensive simulations of the SELENE mission. This work focuses on the determination of the global lunar gravity field from all available tracking data to this date. In preparation for the SELENE mission, analysis using Lunar Prospector tracking data, as well as Clementine data and historical data from the Apollo and Lunar Orbiter projects is being conducted at NAOJ. Some SMART-1 tracking data are also included. The goal is to combine the good-quality data from the existing lunar missions up to this date with the tracking data from SELENE in order to derive a new lunar gravity field model. The focus therefore currently lies on processing the available data and extracting lunar gravity field information from them. It is shown that the historical tracking data contribute especially to the lower degrees of the global lunar gravity field model. Due to the large gap in tracking data coverage over the far side for the historical data, the higher degrees are almost fully determined by the a priori information in the form of a Kaula rule. The combination with SELENE data is thus expected to improve the estimate for the lower degrees even further, including coverage of the far side. Since historical tracking data are from orbits with

  11. Nomad rover field experiment, Atacama Desert, Chile 1. Science results overview

    Science.gov (United States)

    Cabrol, N. A.; Thomas, G.; Witzke, B.

    2001-04-01

    Nomad was deployed for a 45 day traverse in the Atacama Desert, Chile, during the summer of 1997. During this traverse, 1 week was devoted to science experiments. The goal of the science experiments was to test different planetary surface exploration strategies that included (1) a Mars mission simulation, (2) a science on the fly experiment, where the rover was kept moving 75% of the operation time. (The goal of this operation was to determine whether or not successful interpretation of the environment is related to the time spent on a target. The role of mobility in helping the interpretation was also assessed.) (3) a meteorite search using visual and instrumental methods to remotely identify meteorites in extreme environments, and (4) a time-delay experiment with and without using the panospheric camera. The results were as follow: the remote science team positively identified the main characteristics of the test site geological environment. The science on the fly experiment showed that the selection of appropriate targets might be even more critical than the time spent on a study area to reconstruct the history of a site. During the same operation the science team members identified and sampled a rock from a Jurassic outcrop that they proposed to be a fossil. The presence of paleolife indicators in this rock was confirmed later by laboratory analysis. Both visual and instrumental modes demonstrated the feasibility, in at least some conditions, of carrying out a field search for meteorites by using remote-controlled vehicles. Finally, metrics collected from the observation of the science team operations, and the use team members made of mission data, provided critical information on what operation sequences could be automated on board rovers in future planetary surface explorations.

  12. Electronic ground support equipment for the Cluster Electric Field and Wave Experiment

    International Nuclear Information System (INIS)

    Sten, T.A.

    1992-10-01

    In a collaboration between ESA and NASA, ionosphere plasma structures will be studied by four indentical space probes to be launched in 1995 from French Guiana. The Electric Field and Wave (EFW) experiment will be designed to measure electric field and density fluctations by means of four sensors, each deployed on a 50 meter wire boom. In order to perform comprehensive tests and calibrations of the EFW experiment, computer controlled electronic ground support equipment has been developed. This report describes the hardware of the equipment, produced and assembled at the University of Oslo. 15 figs

  13. Fladis field experiments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, M.; Ott, S.

    1996-06-01

    The objective of the Fladis field experiments was to investigate dispersion of liquefied ammonia with equal attention to the near-source aerosol jet, the intermediate heavy gas dispersion phase, and the downstream transition to passive dispersion. The present report presents the sensor layout and gives an overview of the available experimental data. This is done for observations in a fixed frame of reference and relative to the instantaneous plume centre line. The moving frame statistics are expected to compare better with wind tunnel simulations and numerical models which do not include plume meandering. The plume mass flux is estimated from the observed plume profiles and compared to the release rate. Average surface concentrations are found with a special interpolation method, and this is used to study how the averaging period affects the plume footprint. The instantaneous plume is non-Gaussian, and this is demonstrated by Lidar measurements in the far field and thermocouple measurements in the near-source jet. Probability functions and a spatial correlation for the concentration are found. The heat budget of the plume shows signs of heat flux from the ground. The composition of the liquid aerosols was observed to change from almost pure ammonia to almost pure water. A new two-dimensional `shallow layer` type model SLAM is developed, and an existing `box` type model for heavy-gas dispersion on a uniform terrain is generalized. (au) 3 tabs., 19 ills., 29 refs.

  14. Parameter determination in a groundwater field polluted by radioactive pollutant

    International Nuclear Information System (INIS)

    Sidauruk, P.; Barokah A; Syafalni; Wibagiyo

    1998-01-01

    The determination of source location and the corresponding parameters in a contaminated groundwater is very important. To be able to predict the distribution of radioactive contaminant in a contaminated field, the knowledge about the source location and the corresponding parameters is a necessity. The model developed in this paper is based on the fact that the relation between the logarithm of the concentration of the radio active contaminant with the squared coordinate is linear. The contaminant transport parameters as well as the a straight line. In other words, the parameters and the source location are determined in a such way that the linear correlation coefficient between the logarithm of the concentration of the radio active contaminant with the squared coordinate is optimized. The developed model is tested with a synthetic data with a satisfactory results. The synthetic data is generated such that can represent the real field. The synthetic data are generated because the real field data is not available. (authors)

  15. British Isles Field Experience: An Initiative in International Education.

    Science.gov (United States)

    Martin, William J.

    The British Isles Field Experience (BIFE) program was initiated at Williamsport Area Community College (WACC) to provide a group of WACC faculty and staff members with individual and group activities of a personal, professional, and cultural nature in order to promote an international perspective that can be infused into student, collegiate, and…

  16. Real time determination of the laser ablated mass by means of electric field-perturbation measurement

    Science.gov (United States)

    Pacheco, P.; Álvarez, J.; Sarmiento, R.; Bredice, F.; Sánchez-Aké, C.; Villagrán-Muniz, M.; Palleschi, V.

    2018-04-01

    A Nd:YAG ns-pulsed laser was used to ablate Al, Cd and Zn targets, which were placed between the plates of a planar charged capacitor. The plasma generates a transient redistribution of the electrical charges on the plates that can be measured as a voltage drop across a resistor connected to the ground plate. This signal is proportional to the capacitor applied voltage, the distance between the plates and the total number of ions produced in the ablation process which in turn is related to the laser energy and the ablated mass. After a series of pulses, the targets were weighed on a thermogravimetric balance to measure the ablated mass. Our results show that the electrical signal measured on the resistor is univocally related to the ablated mass from the target. Therefore, after a proper calibration depending on the material and the experimental geometry, the electrical signal can be used for real time quantitative measurement of the ablated mass in pulsed laser generated plasma experiments. The experiments were repeated on an aluminum target, with and without the presence of the external electric field in order to determine the possible influence of the applied electric field on the ablated mass.

  17. Turbulent Dynamo Amplification of Magnetic Fields in Laser-Produced Plasmas: Simulations and Experiments

    Science.gov (United States)

    Tzeferacos, P.; Rigby, A.; Bott, A.; Bell, A.; Bingham, R.; Casner, A.; Cattaneo, F.; Churazov, E.; Forest, C.; Katz, J.; Koenig, M.; Li, C.-K.; Meinecke, J.; Petrasso, R.; Park, H.-S.; Remington, B.; Ross, J.; Ryutov, D.; Ryu, D.; Reville, B.; Miniati, F.; Schekochihin, A.; Froula, D.; Lamb, D.; Gregori, G.

    2017-10-01

    The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and neutron stars. The standard model for cosmological magnetic fields is the nonlinear amplification of seed fields via turbulent dynamo. We have conceived experiments to demonstrate and study the turbulent dynamo mechanism in the laboratory. Here, we describe the design of these experiments through large-scale 3D FLASH simulations on the Mira supercomputer at ANL, and the laser-driven experiments we conducted with the OMEGA laser at LLE. Our results indicate that turbulence is capable of rapidly amplifying seed fields to near equipartition with the turbulent fluid motions. This work was supported in part from the ERC (FP7/2007-2013, No. 256973 and 247039), and the U.S. DOE, Contract No. B591485 to LLNL, FWP 57789 to ANL, Grant No. DE-NA0002724 and DE-SC0016566 to the University of Chicago, and DE-AC02-06CH11357 to ANL.

  18. Field dose radiation determination by active learning with Gaussian Process for autonomous robot guiding

    International Nuclear Information System (INIS)

    Freitas Naiff, Danilo de; Silveira, Paulo R.; Pereira, Claudio M.N.A.

    2017-01-01

    This article proposes an approach for determination of radiation dose pro le in a radiation-susceptible environment, aiming to guide an autonomous robot in acting on those environments, reducing the human exposure to dangerous amount of dose. The approach consists of an active learning method based on information entropy reduction, using log-normally warped Gaussian Process (GP) as surrogate model, resulting in non-linear online regression with sequential measurements. Experiments with simulated radiation dose fields of varying complexity were made, and results showed that the approach was effective in reconstruct the eld with high accuracy, through relatively few measurements. The technique was also shown some robustness in presence measurement noise, present in real measurements, by assuming Gaussian noise. (author)

  19. Field dose radiation determination by active learning with Gaussian Process for autonomous robot guiding

    Energy Technology Data Exchange (ETDEWEB)

    Freitas Naiff, Danilo de; Silveira, Paulo R.; Pereira, Claudio M.N.A., E-mail: danilonai1992@poli.ufrj.br, E-mail: paulo@lmp.ufrj.br, E-mail: cmnap@ien.gov.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-11-01

    This article proposes an approach for determination of radiation dose pro le in a radiation-susceptible environment, aiming to guide an autonomous robot in acting on those environments, reducing the human exposure to dangerous amount of dose. The approach consists of an active learning method based on information entropy reduction, using log-normally warped Gaussian Process (GP) as surrogate model, resulting in non-linear online regression with sequential measurements. Experiments with simulated radiation dose fields of varying complexity were made, and results showed that the approach was effective in reconstruct the eld with high accuracy, through relatively few measurements. The technique was also shown some robustness in presence measurement noise, present in real measurements, by assuming Gaussian noise. (author)

  20. The Role of Laboratory Experiments in the Validation of Field Data

    DEFF Research Database (Denmark)

    Mouneyrac, Catherine; Lagarde, Fabienne; Chatel, Amelie

    2017-01-01

    The ubiquitous presence and persistency of microplastics (MPs) in aquatic environments are of particular concern, since they constitute a potential threat to marine organisms and ecosystems. However, evaluating this threat and the impacts of MP on aquatic organisms is challenging. MPs form a very...... and to what degree these complexities are addressed in the current literature, to: (1) evaluate how well laboratory studies, investigated so far, represent environmentally relevant processes and scenarios and (2) suggest directions for future research The Role of Laboratory Experiments in the Validation...... of Field Data | Request PDF. Available from: https://www.researchgate.net/publication/310360438_The_Role_of_Laboratory_Experiments_in_the_Validation_of_Field_Data [accessed Jan 15 2018]....

  1. Combinatorial Quantum Field Theory and Gluing Formula for Determinants

    NARCIS (Netherlands)

    Reshetikhin, N.; Vertman, B.

    2015-01-01

    We define the combinatorial Dirichlet-to-Neumann operator and establish a gluing formula for determinants of discrete Laplacians using a combinatorial Gaussian quantum field theory. In case of a diagonal inner product on cochains we provide an explicit local expression for the discrete

  2. Identifying Discrimination at Work: The Use of Field Experiments.

    Science.gov (United States)

    Pager, Devah; Western, Bruce

    2012-06-01

    Antidiscrimination law offers protection to workers who have been treated unfairly on the basis of their race, gender, religion, or national origin. In order for these protections to be invoked, however, potential plaintiffs must be aware of and able to document discriminatory treatment. Given the subtlety of contemporary forms of discrimination, it is often difficult to identify discrimination when it has taken place. The methodology of field experiments offers one approach to measuring and detecting hiring discrimination, providing direct observation of discrimination in real-world settings. In this article, we discuss the findings of two recent field experiments measuring racial discrimination in low wage labor markets. This research provides several relevant findings for researchers and those interested in civil rights enforcement: (1) it produces estimates of the rate of discrimination at the point of hire; (2) it yields evidence about the interactions associated with discrimination (many of which reveal the subtlety with which contemporary discrimination is practiced); and (3) it provides a vehicle for both research on and enforcement of antidiscrimination law.

  3. Determination of microturbulence enhanced electron collisionality in magnetized coaxial accelerator channels by direct magnetic field measurement

    International Nuclear Information System (INIS)

    Black, D.C.; Mayo, R.M.; Caress, R.W.

    1997-01-01

    A miniature magnetic probe array, consisting of 10 spatially separated coils, has been used to obtain profile information on the time varying magnetic field within the 2.54 cm wide flow channel of the coaxial plasma source experiment (CPS-1) [R. M. Mayo et al., Plasma Sources Sci. Technol. 4, 47 (1995)]. The magnetic field data have been used, together with a resistive, Hall magnetohydrodynamic (MHD) model of applied field distortion by the flowing plasma, to obtain estimates of the microturbulent enhancement to electron collisionality within the CPS-1 flow channel. These measurements provide direct experimental evidence of anomalous electron collisionality, a previously predicted effect in these devices. The anomaly parameter, a=ν an /ν cl , determined both from the distortion of contours of constant magnetic flux, and from local B θ and B z measurements scales with the classical electron magnetization parameter (Ω cl =ω ce /ν e cl ), indicating that collisionality plays a strong role in determining the level of anomalous transport in the plasma. When this anomaly parameter scaling is cast in terms of the ratio ν e cl /ω lh , it is found that the resistivity enhancement scales with ν e cl /ω lh , and becomes significant at ν e cl /ω lh ≤1, suggesting that a lower hybrid drift instability may be the responsible mechanism for enhanced transport. copyright 1997 American Institute of Physics

  4. Physical barriers formed from gelling liquids: 1. numerical design of laboratory and field experiments

    International Nuclear Information System (INIS)

    Finsterle, S.; Moridis, G.J.; Pruess, K.; Persoff, P.

    1994-01-01

    The emplacement of liquids under controlled viscosity conditions is investigated by means of numerical simulations. Design calculations are performed for a laboratory experiment on a decimeter scale, and a field experiment on a meter scale. The purpose of the laboratory experiment is to study the behavior of multiple gout plumes when injected in a porous medium. The calculations for the field trial aim at designing a grout injection test from a vertical well in order to create a grout plume of a significant extent in the subsurface

  5. A modified Stern-Gerlach experiment using a quantum two-state magnetic field

    Science.gov (United States)

    Daghigh, Ramin G.; Green, Michael D.; West, Christopher J.

    2018-06-01

    The Stern-Gerlach experiment has played an important role in our understanding of quantum behavior. We propose and analyze a modified version of this experiment where the magnetic field of the detector is in a quantum superposition, which may be experimentally realized using a superconducting flux qubit. We show that if incident spin-1/2 particles couple with the two-state magnetic field, a discrete target distribution results that resembles the distribution in the classical Stern-Gerlach experiment. As an application of the general result, we compute the distribution for a Gaussian waveform of the incident fermion. This analysis allows us to demonstrate theoretically: (1) the quantization of the intrinsic angular momentum of a spin-1/2 particle, and (2) a correlation between EPR pairs leading to nonlocality, without necessarily collapsing the particle's spin wavefunction.

  6. Electromagnetic Emissions During Rock-fracturing Experiments Inside Magnetic Field Free Space

    Science.gov (United States)

    Wang, H.; Zhou, J.; Zhu, T.; Jin, H.

    2012-12-01

    Abnormal electromagnetic emission (EME) signal is one type of the most important precursors before earthquake, which has been widely observed and recorded before large earthquake, but the physical mechanism underlying the phenomenon is unclear and under controversy. Monitoring the EME signals during rock-fracturing experiments in laboratory is an effective way to study the phenomena and their underlying mechanism. Electromagnetic noise is everywhere because industrial and civilian electrical equipments have been widely used, which make difficulties to the in-lab experiments and field monitoring. To avoid the interference from electromagnetic noise, electromagnetic experiments must be carried out inside shielded space. Magnetic Field Free Space (MFFS) was constructed by Institute of Geophysics, China Earthquake Administration in 1980s. MFFS is a near-spherical polyhedron 'space' with 26 faces and inside diameter about 2.3 m. It is enclosed by 8-layer permalloy 1J85 for shielding magnetic field and 2-layer purified aluminium for shielding electric field. MFFS mainly shields static magnetic field by a factor of 160-4000 for the magnetic signals with the frequencies ranging from 0.01 Hz to 10 Hz. The intensity of magnetic field inside the space is less than 20 nT and its fluctuation is less than 0.3 nT in 90 hours. MFFS can dramatically shield EME signals in the frequency range of EME antennas utilized in our experiments, (several to ~320) kHz, by at least 90%, based on observation. Rock specimens (granite, marble) were fractured by two ways inside MFFS. 1) Cuboid bulk specimens were drilled, filled with static cracking agent, and then dilated from inside until fracture. 2) Cylindrical rock specimens were stressed until fracture by using a non-magnetic rock testing machine with the maximum testing force 300kN. EME, acoustic emission (AE) and strain signals were collected synchronously by the same data acquisitor, Acoustic Emission Workstation made by Physical Acoustics

  7. Attention discrimination: theory and field experiments with monitoring information acquisition

    Czech Academy of Sciences Publication Activity Database

    Bartoš, Vojtěch; Bauer, M.; Chytilová, J.; Matějka, Filip

    2016-01-01

    Roč. 106, č. 6 (2016), s. 1437-1475 ISSN 0002-8282 R&D Projects: GA ČR(CZ) GA14-30724S Institutional support: PRVOUK-P23 Keywords : inattention * discrimination * field experiment Subject RIV: AH - Economics Impact factor: 4.026, year: 2016

  8. Determinants Of Job Satisfaction Of Field Extension Workers In ...

    African Journals Online (AJOL)

    Factor analysis was used to isolate the determinants of job satisfaction of field extension workers in Enugu State Agricultural Development Programme. Data was collected from 42 randomly selected respondents with the aid of structured questionnaire. Findings of the study showed that majority (about 58%) of the ...

  9. Life on the edge: squirrel-cage fringe fields and their effects in the MBE-4 combiner experiment

    International Nuclear Information System (INIS)

    Fawley, W.M.

    1996-02-01

    The MBE-4 combiner experiment employs an electrostatic combined-function focusing/bending element, the so-called ''squirrel-cage'' just before the actual merging region. There has been concern that non-linear fields, primarily in the fringe regions at the beginning and end of the cage, may be strong enough to lead to significant emittance degradation. This note present the results of numerical calculations which determined the anharmonic, non-linear components of the 3D fields in the cage and the resultant, orbit-integrated effects upon the MBE-4 beamlets. We find that while the anharmonic effects are small compared to the dipole deflection, the resultant transverse emittance growth is significant when compared to the expected value of the initial emittance of the individual beamlets

  10. Bacterial Transport in Heterogeneous Porous Media: Laboratory and Field Experiments

    Science.gov (United States)

    Fuller, M. E.

    2001-12-01

    A fully instrumented research site for examining field-scale bacterial transport has been established on the eastern shore of Virginia. Studies employing intact sediment cores from the South Oyster site have been performed to examine the effects of physical and chemical heterogeneity, to derive transport parameters, and to aid in the selection of bacterial strains for use in field experiments. A variety of innovative methods for tracking bacteria were developed and evaluated under both laboratory and field conditions, providing the tools to detect target cell concentrations in groundwater down to effects of physical and chemical heterogeneity on field-scale bacterial transport. The results of this research not only contribute to the development of more effective bioremediation strategies, but also have implications for a better understanding of bacterial movement in the subsurface as it relates to public health microbiology and general microbial ecology.

  11. Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

    International Nuclear Information System (INIS)

    Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

    1980-01-01

    Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

  12. Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

    International Nuclear Information System (INIS)

    Anderson, D.V.; Auerbach, S.P.; Berk, H.L.

    1980-01-01

    Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are dramatically improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented

  13. Controlling stray electric fields on an atom chip for experiments on Rydberg atoms

    Science.gov (United States)

    Davtyan, D.; Machluf, S.; Soudijn, M. L.; Naber, J. B.; van Druten, N. J.; van Linden van den Heuvell, H. B.; Spreeuw, R. J. C.

    2018-02-01

    Experiments handling Rydberg atoms near surfaces must necessarily deal with the high sensitivity of Rydberg atoms to (stray) electric fields that typically emanate from adsorbates on the surface. We demonstrate a method to modify and reduce the stray electric field by changing the adsorbate distribution. We use one of the Rydberg excitation lasers to locally affect the adsorbed dipole distribution. By adjusting the averaged exposure time we change the strength (with the minimal value less than 0.2 V /cm at 78 μ m from the chip) and even the sign of the perpendicular field component. This technique is a useful tool for experiments handling Rydberg atoms near surfaces, including atom chips.

  14. Determining the effect of turbulent shear on containment aerosol dynamics using microgravity experiments

    International Nuclear Information System (INIS)

    Scott, C.K.; Abdelbaky, M.

    1997-01-01

    Determining the characteristics of large aerosol aggregates 'clusters' under turbulent conditions is fundamental for predicting the behaviour of radioactive aerosols inside the reactor containment following a severe accident. Studying such rapidly settling clusters is extremely difficult in ground-based experiments due to the effect of the earth's gravity. In this study, the microgravity environment is exploited to investigate the effect of turbulent shear on the aggregation and breakage of clusters by examining their structure and measuring their strength parameters while suspended under weightlessness conditions. A parametric model is introduced to correlate the experimental results over into nuclear aerosol models. It was demonstrated that the cluster parameters depend mainly on the turbulent field intensity as well as initial powder conditions. (author)

  15. Evaluation of Fast-Time Wake Models Using Denver 2006 Field Experiment Data

    Science.gov (United States)

    Ahmad, Nash’at N.; Pruis, Matthew J.

    2015-01-01

    The National Aeronautics and Space Administration conducted a series of wake vortex field experiments at Denver in 2003, 2005, and 2006. This paper describes the lidar wake vortex measurements and associated meteorological data collected during the 2006 deployment, and includes results of recent reprocessing of the lidar data using a new wake vortex algorithm and estimates of the atmospheric turbulence using a new algorithm to estimate eddy dissipation rate from the lidar data. The configuration and set-up of the 2006 field experiment allowed out-of-ground effect vortices to be tracked in lateral transport further than any previous campaign and thereby provides an opportunity to study long-lived wake vortices in moderate to low crosswinds. An evaluation of NASA's fast-time wake vortex transport and decay models using the dataset shows similar performance as previous studies using other field data.

  16. Enabling Field Experiences in Introductory Geoscience Classes through the Use of Immersive Virtual Reality

    Science.gov (United States)

    Moysey, S. M.; Smith, E.; Sellers, V.; Wyant, P.; Boyer, D. M.; Mobley, C.; Brame, S.

    2015-12-01

    Although field experiences are an important aspect of geoscience education, the opportunity to provide physical world experiences to large groups of introductory students is often limited by access, logistical, and financial constraints. Our project (NSF IUSE 1504619) is investigating the use of immersive virtual reality (VR) technologies as a surrogate for real field experiences in introductory geosciences classes. We are developing a toolbox that leverages innovations in the field of VR, including the Oculus Rift and Google Cardboard, to enable every student in an introductory geology classroom the opportunity to have a first-person virtual field experience in the Grand Canyon. We have opted to structure our VR experience as an interactive game where students must explore the Canyon to accomplish a series of tasks designed to emphasize key aspects of geoscience learning. So far we have produced two demo products for the virtual field trip. The first is a standalone "Rock Box" app developed for the iPhone, which allows students to select different rock samples, examine them in 3D, and obtain basic information about the properties of each sample. The app can act as a supplement to the traditional rock box used in physical geology labs. The second product is a fully functioning VR environment for the Grand Canyon developed using satellite-based topographic and imagery data to retain real geologic features within the experience. Players can freely navigate to explore anywhere they desire within the Canyon, but are guided to points of interest where they are able to complete exercises that will be aligned with specific learning goals. To this point we have integrated elements of the "Rock Box" app within the VR environment, allowing players to examine 3D details of rock samples they encounter within the Grand Canyon. We plan to provide demos of both products and obtain user feedback during our presentation.

  17. Determination of near field excavation disturbance in crystalline rock

    International Nuclear Information System (INIS)

    Koopmans, R.; Hughes, R.W.

    1986-01-01

    The computerized dilatometer system has rapidly and economically provided deformation moduli of low and high modulus rock, determined the extent of excavation disturbance surrounding an underground opening and located open fracture within a rock mass. Results from both test sites indicate that the moduli obtained were influenced by the in situ tangential stress field. It has been shown that the near field excavation disturbance is kept to a minimum through the use of careful excavation techniques such as the tunnel boring machine. In turn, the in situ tangential stress levels and deformation moduli are maximized while the corresponding permeability is minimized

  18. Magnetic field experiment on the SUNSAT satellite

    Science.gov (United States)

    Kotzé, P. B.; Langenhoven, B.; Risbo, T.

    2002-03-01

    On Tuesday 23 February 1999, at 10:29 UTC, SUNSAT was launched into an 857×655 km, 96.47° polar orbit on a Boeing-Delta II rocket from Vandenberg Air Force Base in California, USA. Both SUNSAT and Ørsted were NASA-sponsored secondary payloads accompanying the USA Air Force Argos satellite. In the process it became South Africa's (and Africa's) first satellite in space. Although sponsored by several private industrial organisations, it is essentially a student project with more than 96 graduate students in the Department of Electronic and Electrical Engineering at the University of Stellenbosch providing the majority of SUNSAT's engineering development and operation since 1992. This paper reports on the magnetic field experiment on board the Sunsat satellite, consisting of two fluxgate magnetometers, called Orimag and Scimag, both built and calibrated by the Hermanus Magnetic Observatory. Orimag is mainly used for orientation control purposes on SUNSAT, while Scimag, mounted on a boom of 2.2 m is designed to perform geomagnetic field observations, employing standard navigation fluxgate technology.

  19. Dynamic Incentive Effects of Relative Performance Pay: A Field Experiment

    NARCIS (Netherlands)

    J. Delfgaauw (Josse); A.J. Dur (Robert); J.A. Non (Arjan); W.J.M.I. Verbeke (Willem)

    2010-01-01

    textabstractWe conduct a field experiment among 189 stores of a retail chain to study dynamic incentive effects of relative performance pay. Employees in the randomly selected treatment stores could win a bonus by outperforming three comparable stores from the control group over the course of four

  20. Overview of quasi single helicity experiments in reversed field pinches

    International Nuclear Information System (INIS)

    Martin, P.; Marrelli, L.; Spizzo, G.

    2003-01-01

    We report the results of an experimental and theoretical project dedicated to the study of Quasi Single Helicity Reversed Field Pinch plasmas. The project has involved several RFP devices and numerical codes. It appears that QSH spectra are a feature common to all the experiments. (author)

  1. A Laboratory Experiment for Rapid Determination of the Stability of Vitamin C

    Science.gov (United States)

    Adem, Seid M.; Lueng, Sam H.; Elles, Lisa M. Sharpe; Shaver, Lee Alan

    2016-01-01

    Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid,…

  2. Designing and Using Virtual Field Environments to Enhance and Extend Field Experience in Professional Development Programs in Geology for K-12 Teachers

    Science.gov (United States)

    Granshaw, Frank Douglas

    2011-12-01

    Virtual reality (VR) is increasingly used to acquaint geoscience novices with some of the observation, data gathering, and problem solving done in actual field situations by geoscientists. VR environments in a variety of forms are used to prepare students for doing geologic fieldwork, as well as to provide proxies for such experience when venturing into the field is not possible. However, despite increased use of VR for these purposes, there is little research on how students learn using these environments, how using them impacts student field experience, or what constitutes effective design in light of emerging theories of geocognition. To address these questions, I investigated the design and use of a virtual reality environment in a professional development program for middle school Earth science teachers called Teachers on the Leading Edge (TOTLE). This environment, called a virtual field environment, or VFE, was based largely on the field sites visited by the participants during summer workshops. It was designed as a tool to prepare the participants for workshop field activities and as a vehicle for taking elements of that experience back to their students. I assessed how effectively the VFE accomplished these goals using a quasi-experimental, mixed method study that involved a series of teaching experiments, interviews, participant surveys, and focus groups. The principle conclusions reached in this study are as follows: 1. In a field trip orientation experiment involving 35 middle school teachers, 90.6% of the participants stated a preference for VFE enhanced orientation over an alternative orientation that used photographs and static maps to complete a practice field activity. When asked about how the VFE prepared them for their field experience, the participants ranked it as most helpful for visualize the location and geography of the field sites. They ranked it lower for helping them visualize structural and geomorphic patterns, and ranked it as least

  3. Respirometric oxygen demand determinations of laboratory- and field-scale biofilters

    International Nuclear Information System (INIS)

    Rho, D.; Mercier, P.; Jette, J.F.

    1995-01-01

    A biofiltration experiment operated at three inlet concentrations (425, 830, and 1,450 mg m -3 ), showed that the specific oxygen consumption rate was highly correlated (R = 0.938, n = 23) with the toluene elimination capacity. A radiorespirometric test was found to be more sensitive and appropriate for the field-scale biofilter treating gasoline vapors

  4. Plot-scale field experiment of surface hydrologic processes with EOS implications

    Science.gov (United States)

    Laymon, Charles A.; Macari, Emir J.; Costes, Nicholas C.

    1992-01-01

    Plot-scale hydrologic field studies were initiated at NASA Marshall Space Flight Center to a) investigate the spatial and temporal variability of surface and subsurface hydrologic processes, particularly as affected by vegetation, and b) develop experimental techniques and associated instrumentation methodology to study hydrologic processes at increasingly large spatial scales. About 150 instruments, most of which are remotely operated, have been installed at the field site to monitor ground atmospheric conditions, precipitation, interception, soil-water status, and energy flux. This paper describes the nature of the field experiment, instrumentation and sampling rationale, and presents preliminary findings.

  5. Validation Study for an Atmospheric Dispersion Model, Using Effective Source Heights Determined from Wind Tunnel Experiments in Nuclear Safety Analysis

    Directory of Open Access Journals (Sweden)

    Masamichi Oura

    2018-03-01

    Full Text Available For more than fifty years, atmospheric dispersion predictions based on the joint use of a Gaussian plume model and wind tunnel experiments have been applied in both Japan and the U.K. for the evaluation of public radiation exposure in nuclear safety analysis. The effective source height used in the Gaussian model is determined from ground-level concentration data obtained by a wind tunnel experiment using a scaled terrain and site model. In the present paper, the concentrations calculated by this method are compared with data observed over complex terrain in the field, under a number of meteorological conditions. Good agreement was confirmed in near-neutral and unstable stabilities. However, it was found to be necessary to reduce the effective source height by 50% in order to achieve a conservative estimation of the field observations in a stable atmosphere.

  6. On the design and implementation of environmental conservation mechanisms : Evidence from field experiments

    NARCIS (Netherlands)

    Kitesa, Rahel

    2018-01-01

    This doctoral dissertation consists of three chapters on the design and implementation of environmental conservation mechanisms using economic experiments. The first chapter examines how variations in information and context affect the outcomes of valuation using field experiment. The chapter shows

  7. The co-creation experience from the customer perspective: its measurement and determinants

    OpenAIRE

    Verleye, Katrien

    2015-01-01

    Purpose - Companies increasingly opt for co-creation by engaging customers in new product and service development processes. The purpose of this paper is to provide insight into the customer experience in co-creation situations and its determinants. Design/methodology/approach - The conceptual framework addresses the customer experience in co-creation situations, and its individual and environmental determinants. To examine the degree to which these determinants affect the customer ex...

  8. Psychology as Field Experience: Impact on Attitudes Toward Social Interventions.

    Science.gov (United States)

    Snellman, Lynn A.; And Others

    An innovation in the teaching of undergraduate psychology courses is the implementation of a field experience that gives students the opportunity to apply newly learned skills and knowledge in a community setting. Changes in undergraduates' attitudes toward various delinquency interventions were examined as a result of participation in a…

  9. Field experiment on multicomponent ion exchange in a sandy aquifer

    International Nuclear Information System (INIS)

    Bjerg, P.L.; Christensen, T.H.

    1990-01-01

    A field experiment is performed in a sandy aquifer in order to study ion exchange processes and multicomponent solute transport modeling. An injection of groundwater spiked with sodium and potassium chloride was performed over a continuous period of 37 days. The plume is monitored by sampling 350 filters in a spatial grid. The sampling aims at establishing compound (calcium, magnesium, potassium, sodium, chloride) breakthrough curves at various filters 15 to 100 m from the point of injection and areal distribution maps at various cross sections from 0 to 200 m from the point of injection. A three-dimensional multicomponent solute transport model will be used to model the field experiments. The chemical model includes cation exchange, precipitation, dissolution, complexation, ionic strength and the carbonate system. Preliminary results from plume monitoring show that the plume migration is relatively well controlled considering the scale and conditions of the experiment. The transverse dispersion is small causing less dilution than expected. The ion exchange processes have an important influence on the plume composition. Retardation of the injected ions is substantial, especially for potassium. Calcium exhibits a substantial peak following chloride due to release from the ion exchange sites on the sediment. (Author) (8 refs., 5 figs., tab.)

  10. Science objectives of the magnetic field experiment onboard Aditya-L1 spacecraft

    Science.gov (United States)

    Yadav, Vipin K.; Srivastava, Nandita; Ghosh, S. S.; Srikar, P. T.; Subhalakshmi, Krishnamoorthy

    2018-01-01

    The Aditya-L1 is first Indian solar mission scheduled to be placed in a halo orbit around the first Lagrangian point (L1) of Sun-Earth system in the year 2018-19. The approved scientific payloads onboard Aditya-L1 spacecraft includes a Fluxgate Digital Magnetometer (FGM) to measure the local magnetic field which is necessary to supplement the outcome of other scientific experiments onboard. The in-situ vector magnetic field data at L1 is essential for better understanding of the data provided by the particle and plasma analysis experiments, onboard Aditya-L1 mission. Also, the dynamics of Coronal Mass Ejections (CMEs) can be better understood with the help of in-situ magnetic field data at the L1 point region. This data will also serve as crucial input for the short lead-time space weather forecasting models. The proposed FGM is a dual range magnetic sensor on a 6 m long boom mounted on the Sun viewing panel deck and configured to deploy along the negative roll direction of the spacecraft. Two sets of sensors (tri-axial each) are proposed to be mounted, one at the tip of boom (6 m from the spacecraft) and other, midway (3 m from the spacecraft). The main science objective of this experiment is to measure the magnitude and nature of the interplanetary magnetic field (IMF) locally and to study the disturbed magnetic conditions and extreme solar events by detecting the CME from Sun as a transient event. The proposed secondary science objectives are to study the impact of interplanetary structures and shock solar wind interaction on geo-space environment and to detect low frequency plasma waves emanating from the solar corona at L1 point. This will provide a better understanding on how the Sun affects interplanetary space. In this paper, we shall give the main scientific objectives of the magnetic field experiment and brief technical details of the FGM onboard Aditya-1 spacecraft.

  11. Determination of the time dependent magnetic field distribution in pulsed-power systems

    Energy Technology Data Exchange (ETDEWEB)

    Maron, Y; Arad, R; Davara, G; Gregorian, L; Krasik, Ya; Kroupp, E; Safarty, M; Shpitalik, R; Weingarten, A [Weizmann Institute of Science, Rehovot (Israel). Faculty of Physics

    1997-12-31

    Time-dependent measurements of the magnetic field distributions in diode, plasma opening switch, and Z-pinch plasmas, based on the observation of the Zeeman effect or of the ion acceleration, are reviewed. Relatively high spatial resolution is obtained by locally doping the plasma with the desired species. Besides information on the device properties the measurements allowed for determining the plasma conductivity and for investigating the field penetration mechanism. Determination of the current density allowed the electron drift velocity to be known. (author). 4 figs., 16 refs.

  12. Field measurement program to determine far field plume dilution parameters

    International Nuclear Information System (INIS)

    Orth, R.C.; Carter, H.H.; Miyasaki, M.T.

    1974-01-01

    A description of the techniques used to obtain measurements of temperature, salinity, tidal velocity and tracer concentration required to determine the far field dilution in a shallow estuary is presented. The study was done to characterize the physical hydrography of the Bush River, a tributary estuary of the Chesapeake Bay, which is a possible recipient of the thermal discharge from a proposed power plant consisting of two 850 MWe nuclear generating units. Measurements of temperature and salinity along the axis of the estuary during periods of high and low fresh water inflow were obtained for use in the development of a one-dimensional-segmented transient state model of the estuary. Computer concentrations from the model compared favorably with measured dye concentrations for the same periods of high and low freshwater inflow

  13. Molecular structure and motion in zero field magnetic resonance

    International Nuclear Information System (INIS)

    Jarvie, T.P.

    1989-10-01

    Zero field magnetic resonance is well suited for the determination of molecular structure and the study of motion in disordered materials. Experiments performed in zero applied magnetic field avoid the anisotropic broadening in high field nuclear magnetic resonance (NMR) experiments. As a result, molecular structure and subtle effects of motion are more readily observed

  14. Field mapping measurements to determine spatial and field dependence of critical current density in YBCO tapes

    International Nuclear Information System (INIS)

    Leclerc, J.; Berger, K.; Douine, B.; Lévêque, J.

    2013-01-01

    Highlights: • A method for characterizing superconducting tapes from field mapping is presented. • A new and efficient field mapping apparatus has been setup. • This method allows the spatial characterization of superconducting tapes. • The critical current density is obtained as a function of the flux density. • This method has been experimentally tested on an YBCO tape. -- Abstract: In this paper a measurement method that allows the determination of the critical current density of superconducting tape from field mapping measurements is presented. This contact-free method allows obtaining characteristics of the superconductor as a function of the position and of the applied flux density. With some modifications, this technique can be used for reel-to-reel measurements. The determination of the critical current density is based on an inverse calculation. This involves calculating the current distribution in the tape from magnetic measurements. An YBaCuO tape has been characterized at 77 K. A defect in this superconductor has been identified. Various tests were carried out to check the efficiency of the method. The inverse calculation was tested theoretically and experimentally. Comparison with a transport current measurement was also performed

  15. Full-field stress determination in photoelasticity with phase shifting technique

    Science.gov (United States)

    Guo, Enhai; Liu, Yonggang; Han, Yongsheng; Arola, Dwayne; Zhang, Dongsheng

    2018-04-01

    Photoelasticity is an effective method for evaluating the stress and its spatial variations within a stressed body. In the present study, a method to determine the stress distribution by means of phase shifting and a modified shear-difference is proposed. First, the orientation of the first principal stress and the retardation between the principal stresses are determined in the full-field through phase shifting. Then, through bicubic interpolation and derivation of a modified shear-difference method, the internal stress is calculated from the point with a free boundary along its normal direction. A method to reduce integration error in the shear difference scheme is proposed and compared to the existing methods; the integration error is reduced when using theoretical photoelastic parameters to calculate the stress component with the same points. Results show that when the value of Δx/Δy approaches one, the error is minimum, and although the interpolation error is inevitable, it has limited influence on the accuracy of the result. Finally, examples are presented for determining the stresses in a circular plate and ring subjected to diametric loading. Results show that the proposed approach provides a complete solution for determining the full-field stresses in photoelastic models.

  16. Evaluation of tetroon flights and turbulent diffusion under weak wind conditions during the field experiment SIESTA

    International Nuclear Information System (INIS)

    Hu Erbang; Vogt, S.

    1986-08-01

    During several days in November 1985 an international field experiment took place in the Swiss plateau region near the cities of Aarau, Olten. As indicated by the name of the project SIESTA (SF 6 International Experiments in Stagnant Air) its aim is to obtain knowledge of the general nature of turbulence advection and atmospheric dispersion processes in a cold pool with very low wind speed and undefined wind direction. An outline of the general concept of the project is followed by a more detailed description of a special research activity with Radar tracked tetroons. In the second part of the report it is shown how to determine the horizontal dispersion parameter from the trajectories of the tetroon flights. Two different methods are described and the results of the flights performed during SIESTA are presented. (orig.) [de

  17. Observed chlorine concentrations during Jack Rabbit I and Lyme Bay field experiments

    Science.gov (United States)

    Hanna, Steven; Chang, Joseph; Huq, Pablo

    2016-01-01

    As part of planning for a series of field experiments where large quantities (up to 20 tons) of pressurized liquefied chlorine will be released, observations from previous chlorine field experiments are analyzed to estimate the ranges of chlorine concentrations expected at various downwind distances. In five field experiment days during the summer 2010 Jack Rabbit I (JR I) field trials, up to two tons of chlorine were released and concentrations were observed at distances, x, from 25 to 500 m. In the 1927 Lyme Bay (LB) experiments, there were four days of trials, where 3-10 tons of chlorine were released in about 15 min from the back of a ship. Concentrations were sampled at LB from four ships sailing across the cloud path at downwind distances in the range from about 350 to 3000 m. Thus, the distances from which JR I concentrations were available slightly overlapped the LB distances. One-minute arc-maximum chlorine concentrations, C (g/m3), were analyzed from four JR I trials and two LB trials. Normalized concentrations (Cu/Q) were plotted versus x (m), where u (m/s) is measured wind speed at heights of 2-10 m and Q (g/s) is continuous mass release rate. It is found that the JR I and LB Cu/Q observations smoothly merge with each other and fall along a line with approximate slope of -2 at distances beyond about 200 m (i.e., Cu/Q is proportional to x-2). At x < 200 m, where dense gas effects are more important, the slope is less (about -1.5). Most of the data points are within a factor of two of the "best-fit" line.

  18. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1979-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x10 15 cm -3 . After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)

  19. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10 15 cm -3 . After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value

  20. Magnetic field-aligned plasma expansion in critical ionization velocity space experiments

    International Nuclear Information System (INIS)

    Singh, N.

    1989-01-01

    Motivated by the recent Critical Ionization Velocity (CIV) experiments in space, the temporal evolution of a plasma cloud released in an ambient plasma is studied. Time-dependent Vlasov equations for both electrons and ions, along with the Poisson equation for the self-consistent electric field parallel to the ambient magnetic field, are solved. The initial cloud is assumed to consist of cold, warm, and hot electrons with temperatures T/sub c/ ≅ 0.2 eV, T/sub w/ ≅ 2 eV, and T/sub h/ ≅ 10 eV, respectively. It is found that the minor hot electrons escape the cloud, and their velocity distribution function shows the typical time-of-flight dispersion feature - that is, the larger the distance from the cloud, the larger is the average drift velocity of the escaping electrons. The major warm electrons expand along the magnetic field line with the corresponding ion-acoustic speed. The combined effect of the escaping hot electrons and the expanding warm ones sets up an electric potential structure which accelerates the ambient electrons into the cloud. Thus, the energy loss due to the electron escape is partly replenished. The electric field distribution in the potential structure depends on the stage of the evolution; before the rarefaction waves propagating from the edges of the cloud reach its center, the electric fields point into the cloud. After this stage the cloud divides into two subclouds, with each having their own bipolar electric fields. Effects of collisions on the evolution of plasma clouds are also discussed. The relevance of the results seen from the calculations are discussed in the context of recent space experiments on CIV

  1. Preference effects on friendship choice: Evidence from an online field experiment.

    Science.gov (United States)

    Yu, Siyu; Xie, Yu

    2017-08-01

    Observed friendship choices are constrained by social structures and thus problematic indicators for underlying personal preferences. In this paper, we report on a study demonstrating the causal effects of preference in friendship choice based on an online field experiment. Specifically, we tested two important forces that govern friendship choices: preference for shared group identity (operationalized as the desire to befriend others sharing the same place-of-origin identity) and preference for high status (operationalized as the desire to befriend others from high-status institutions). Using an online field experiment in one of the largest social network service websites in China, we investigated the causal preference effects of these two forces free from structural constraints. The results of our study confirm the preference effects on friendship choice in both of the two dimensions we tested. Copyright © 2017. Published by Elsevier Inc.

  2. Interlaboratory determinations of isotopically enriched metals by field desorption mass spectroscopy

    International Nuclear Information System (INIS)

    Bahr, U.; Schulten, H.R.; Achenbach, C.; Ziskoven, R.

    1982-01-01

    The isotopic distribution of stable isotopes in six enriched metals (calcium, copper, barium, rubidium, strontium and thallium) has been determined by field desorption mass spectrometry. A first evaluation of the interlaboratory reproducibility of the application of this method for trace determination of metals was made using three different types of mass spectrometers in three different laboratories. The standard deviations for the most abundant isotopes of the metals investigated are between +-0.1 and +-0.5%. Within these standard deviations, the values obtained by the three mass spectrometry groups are the same. To support the accuracy of our quantification, thermal ionization mass spectrometry has been employed and confirms the results of the field desorption method. (orig.) [de

  3. When Field Experiments Yield Unexpected Results: Lessons Learned from Measuring Selection in White Sands Lizards

    Science.gov (United States)

    Hardwick, Kayla M.; Harmon, Luke J.; Hardwick, Scott D.; Rosenblum, Erica Bree

    2015-01-01

    Determining the adaptive significance of phenotypic traits is key for understanding evolution and diversification in natural populations. However, evolutionary biologists have an incomplete understanding of how specific traits affect fitness in most populations. The White Sands system provides an opportunity to study the adaptive significance of traits in an experimental context. Blanched color evolved recently in three species of lizards inhabiting the gypsum dunes of White Sands and is likely an adaptation to avoid predation. To determine whether there is a relationship between color and susceptibility to predation in White Sands lizards, we conducted enclosure experiments, quantifying survivorship of Holbrookia maculate exhibiting substrate-matched and substrate-mismatched phenotypes. Lizards in our study experienced strong predation. Color did not have a significant effect on survival, but we found several unexpected relationships including variation in predation over small spatial and temporal scales. In addition, we detected a marginally significant interaction between sex and color, suggesting selection for substrate matching may be stronger for males than females. We use our results as a case study to examine six major challenges frequently encountered in field-based studies of natural selection, and suggest that insight into the complexities of selection often results when experiments turn out differently than expected. PMID:25714838

  4. Rational Ignorance in Education: A Field Experiment in Student Plagiarism

    Science.gov (United States)

    Dee, Thomas S.; Jacob, Brian A.

    2012-01-01

    Plagiarism appears to be a common problem among college students, yet there is little evidence on the effectiveness of interventions designed to minimize plagiarism. This study presents the results of a field experiment that evaluated the effects of a web-based educational tutorial in reducing plagiarism. We found that assignment to the treatment…

  5. Targets with thin ferromagnetic layers for transient field experiments

    International Nuclear Information System (INIS)

    Gallant, J.L.; Dmytrenko, P.

    1982-01-01

    Multilayer targets containing a central layer sufficiently thin so that all recoil nuclei can traverse it and subsequently stop in a suitable cubic environment have been prepared. Such targets are required in experiments making use of a magnetic field acting on an ion moving through a ferromagnetic material. The preparation and annealing of the ferromagnetic foils (iron and gadolinium) and the fabrication of the multilayer targets are described. (orig.)

  6. Determination of Soil Moisture Content using Laboratory Experimental and Field Electrical Resistivity Values

    Science.gov (United States)

    Hazreek, Z. A. M.; Rosli, S.; Fauziah, A.; Wijeyesekera, D. C.; Ashraf, M. I. M.; Faizal, T. B. M.; Kamarudin, A. F.; Rais, Y.; Dan, M. F. Md; Azhar, A. T. S.; Hafiz, Z. M.

    2018-04-01

    The efficiency of civil engineering structure require comprehensive geotechnical data obtained from site investigation. In the past, conventional site investigation was heavily related to drilling techniques thus suffer from several limitations such as time consuming, expensive and limited data collection. Consequently, this study presents determination of soil moisture content using laboratory experimental and field electrical resistivity values (ERV). Field and laboratory electrical resistivity (ER) test were performed using ABEM SAS4000 and Nilsson400 soil resistance meter. Soil sample used for resistivity test was tested for characterization test specifically on particle size distribution and moisture content test according to BS1377 (1990). Field ER data was processed using RES2DINV software while laboratory ER data was analyzed using SPSS and Excel software. Correlation of ERV and moisture content shows some medium relationship due to its r = 0.506. Moreover, coefficient of determination, R2 analyzed has demonstrate that the statistical correlation obtain was very good due to its R2 value of 0.9382. In order to determine soil moisture content based on statistical correlation (w = 110.68ρ-0.347), correction factor, C was established through laboratory and field ERV given as 19.27. Finally, this study has shown that soil basic geotechnical properties with particular reference to water content was applicably determined using integration of laboratory and field ERV data analysis thus able to compliment conventional approach due to its economic, fast and wider data coverage.

  7. Overview of long-term field experiments in Germany - metadata visualization

    Science.gov (United States)

    Muqit Zoarder, Md Abdul; Heinrich, Uwe; Svoboda, Nikolai; Grosse, Meike; Hierold, Wilfried

    2017-04-01

    BonaRes ("soil as a sustainable resource for the bioeconomy") is conducting to collect data and metadata of agricultural long-term field experiments (LTFE) of Germany. It is funded by the German Federal Ministry of Education and Research (BMBF) under the umbrella of the National Research Strategy BioEconomy 2030. BonaRes consists of ten interdisciplinary research project consortia and the 'BonaRes - Centre for Soil Research'. BonaRes Data Centre is responsible for collecting all LTFE data and regarding metadata into an enterprise database upon higher level of security and visualization of the data and metadata through data portal. In the frame of the BonaRes project, we are compiling an overview of long-term field experiments in Germany that is based on a literature review, the results of the online survey and direct contacts with LTFE operators. Information about research topic, contact person, website, experiment setup and analyzed parameters are collected. Based on the collected LTFE data, an enterprise geodatabase is developed and a GIS-based web-information system about LTFE in Germany is also settled. Various aspects of the LTFE, like experiment type, land-use type, agricultural category and duration of experiment, are presented in thematic maps. This information system is dynamically linked to the database, which means changes in the data directly affect the presentation. An easy data searching option using LTFE name, -location or -operators and the dynamic layer selection ensure a user-friendly web application. Dispersion and visualization of the overlapping LTFE points on the overview map are also challenging and we make it automatized at very zoom level which is also a consistent part of this application. The application provides both, spatial location and meta-information of LTFEs, which is backed-up by an enterprise geodatabase, GIS server for hosting map services and Java script API for web application development.

  8. CRISP. D3.3. Final report on field experiments and tests

    International Nuclear Information System (INIS)

    Warmer, C.J.; Kamphuis, I.G.; Gustavsson, R.; Andrieu, C.

    2006-06-01

    This document describes the high level results of the three field experiments and tests performed within the CRISP project. The aims of the document are: To give an account of the lessons learned from the experiments as they have been performed; To give recommendations for strategic use of intelligent ICT in high-DG power networks (thinking forward from our experience in the experiments); and To compile 'industrial guidelines and recommendations' for the strategic use of intelligent ICT for various operational aspects of high-DG power networks. These strategic recommendations will not only cover technology issues, but also business, economic, and market considerations. The role of utilities and third parties in utilising this new technology in this changing scene forms an important issue to be dealt with

  9. Searching for Authentic Context in Designing PISA-like Mathematics Problem: From Indoor to Outdoor Field Experience

    Science.gov (United States)

    Siswono, T. Y. E.; Kohar, A. W.; Rosyidi, A. H.; Hartono, S.; Masriyah

    2018-01-01

    Designing problem like in PISA is known as a challenging activity for teachers particularly as the use of authentic context within that type of problem. This paper aims to describe the experiences of secondary mathematics teachers in designing PISA-like problems within an innovative training program focusing on building teachers’ understanding on the concept of mathematical literacy. The teachers were engaged in a set of problem-solving and problem-posing activities using PISA-based problem within indoor and outdoor field experiences. Within indoor field experience, the teachers worked collaboratively in groups on designing PISA-like problems with a given context through problem generation and reformulation techniques. Within outdoor field experience, they worked on designing PISA-like problems with self-chosen context from the place where the outdoor field experience took place. Our analysis indicates that there were improvements on the PISA-like problems designed by teachers based on its level use of context from indoor to outdoor experience. Also, the teachers were relatively successful with creating appropriate and motivating contexts by harnessing a variety of context consisting of personal, occupational, societal, and scientific contexts. However, they still experienced difficulties in turning these contexts into an appropriate problem satisfying PISA framework such as regarding authenticity of context use, language structure, and PISA task profile.

  10. Analysis of biostimulated microbial communities from two field experiments reveals temporal and spatial differences in proteome profiles

    Energy Technology Data Exchange (ETDEWEB)

    Callister, S.J.; Wilkins, M.J.; Nicora, C.D.; Williams, K.H.; Banfield, J.F.; VerBerkmoes, N.C.; Hettich, R.L.; NGuessan, A.L.; Mouser, P.J.; Elifantz, H.; Smith, R.D.; Lovley, D.R.; Lipton, M.S.; Long, P.E.

    2010-07-15

    Stimulated by an acetate-amendment field experiment conducted in 2007, anaerobic microbial populations in the aquifer at the Rifle Integrated Field Research Challenge site in Colorado reduced mobile U(VI) to insoluble U(IV). During this experiment, planktonic biomass was sampled at various time points to quantitatively evaluate proteomes. In 2008, an acetate-amended field experiment was again conducted in a similar manner to the 2007 experiment. As there was no comprehensive metagenome sequence available for use in proteomics analysis, we systematically evaluated 12 different organism genome sequences to generate sets of aggregate genomes, or “pseudo-metagenomes”, for supplying relative quantitative peptide and protein identifications. Proteomics results support previous observations of the dominance of Geobacteraceae during biostimulation using acetate as sole electron donor, and revealed a shift from an early stage of iron reduction to a late stage of iron reduction. Additionally, a shift from iron reduction to sulfate reduction was indicated by changes in the contribution of proteome information contributed by different organism genome sequences within the aggregate set. In addition, the comparison of proteome measurements made between the 2007 field experiment and 2008 field experiment revealed differences in proteome profiles. These differences may be the result of alterations in abundance and population structure within the planktonic biomass samples collected for analysis.

  11. Data from the Hot Serial Cereal Experiment for modeling wheat response to temperature: field experiments and AgMIP-Wheat multi-model simulations

    NARCIS (Netherlands)

    Martre, Pierre; Kimball, Bruce A.; Ottman, Michael J.; Wall, Gerard W.; White, Jeffrey W.; Asseng, Senthold; Ewert, Frank; Cammarano, Davide; Maiorano, Andrea; Aggarwal, Pramod K.; Supit, I.; Wolf, J.

    2018-01-01

    The dataset reported here includes the part of a Hot Serial Cereal Experiment (HSC) experiment recently used in the AgMIP-Wheat project to analyze the uncertainty of 30 wheat models and quantify their response to temperature. The HSC experiment was conducted in an open-field in a semiarid

  12. OVERCONFIDENCE, OMENS AND EMOTIONS: RESULTS FROM A FIELD EXPERIMENT

    OpenAIRE

    Maria De Paola; Francesca Gioia; Vincenzo Scoppa

    2013-01-01

    We analyze how overconfidence is affected by superstitious beliefs and emotions induced by positive and negative stimuli in a field experiment involving about 700 Italian students who were randomly assigned to numbered seats in their written examination sessions. According to widespread superstitions, some numbers are considered lucky, while others are considered unlucky. At the end of the examination, we asked students the grade they expected to get. We find that students tend to be systemat...

  13. Chernobyl Experience in the Field of Retrospective Dosimetry

    International Nuclear Information System (INIS)

    Chumak, V.; Bakhanova, E.

    2011-01-01

    Chernobyl accident, which occurred on April 26, 1986 at NPP located less than 150 km north of Kiev, is the largest nuclear accident ever. Unprecedented scale of the accident was determined not only by the amount of released activity, but also by a number of population and workers involved and, therefore, exposed to enhanced doses of ionizing radiation. Population of the 30-km exclusion zone numbering about 116,000 persons of all ages and both genders was evacuated within days and weeks after the accident, emergency workers called ''liquidators of the accident'' (males age 20-50) were involved into clean-up and recovery for 5 years and their number is estimated as 600,000, about 300,000 are Ukrainian citizens. Due to unexpected and excessively large scale accident, none of residents had personal dosimeters, personal dosimetry of liquidators was not total, dosimetry techniques and practices were far from the optimum. As a result, an acute need for retrospective dose assessment was dictated by radiation protection and research considerations. This need was responded by implementation of wide scale dose reconstruction efforts, which covered main exposed cohorts and encompassed broad variety of newly developed methods: analytical (time-and-motion), modeling, biological and physical (EPR spectroscopy of teeth, TL of quartz). The presentation summarizes vast experience accumulated by RCRM in the field of retrospective dosimetry of large cohorts of exposed population and professionals. These dose reconstruction projects were implemented, in particular, in the framework of epidemiological studies, designed to follow-up medical consequences of Chernobyl accident and study health effects of ionizing radiation, in particular, Ukrainian-American studies of cataracts and leukemia among liquidators. Over 25 years passed after Chernobyl accident a broad variety of retrospective dosimetry problems was addressed by the team of Research Center for Radiation Medicine AMS Ukraine. In

  14. Laboratory experiments on plasma jets in a magnetic field using high-power lasers

    Directory of Open Access Journals (Sweden)

    Nishio K.

    2013-11-01

    Full Text Available The experiments to simulate astrophysical jet generation are performed using Gekko XII (GXII HIPER laser system at the Institute of Laser Engineering. In the experiments a fast plasma flow generated by shooting a CH plane (10 μm thickness is observed at the rear side of the plane. By separating the focal spot of the main beams, a non-uniform plasma is generated. The non-uniform plasma flow in an external magnetic field (0.2∼0.3 T perpendicular to the plasma is more collimated than that without the external magnetic field. The plasma β, the ratio between the plasma and magnetic pressure, is ≫ 1, and the magnetic Reynolds number is ∼150 in the collimated plasma. It is considered that the magnetic field is distorted by the plasma flow and enhances the jet collimation.

  15. Sound Design in Virtual Reality Concert Experiences using a Wave Field Synthesis Approach

    DEFF Research Database (Denmark)

    Lind, Rasmus Bloustrød; Milesen, Victor; Smed, Dina Madsen

    2017-01-01

    In this paper we propose an experiment that evaluates the influence of audience noise on the feeling of presence and the perceived quality in a virtual reality concert experience delivered using Wave Field Synthesis. A 360 degree video of a live rock concert from a local band was recorded. Single...

  16. Field experiments on eyewitness identification: towards a better understanding of pitfalls and prospects.

    Science.gov (United States)

    Wells, Gary L

    2008-02-01

    The Illinois pilot program on lineup procedures has helped sharpen the focus on the types of controls that are needed in eyewitness field experiments and the limits that exist for interpreting outcome measures (rates of suspect and filler identifications). A widely-known limitation of field experiments is that, unlike simulated crime experiments, the guilt or innocence of the suspects is not easily known independently of the behavior of the eyewitnesses. Less well appreciated is that the rate of identification of lineup fillers, although clearly errors, can be a misleading measure if the filler identification rate is used to assess which of two or more lineup procedures is the better procedure. Several examples are used to illustrate that there are clearly improper procedures that would yield fewer identifications of fillers than would their proper counterparts. For example, biased lineup structure (e.g., using poorly matched fillers) as well as suggestive lineup procedures (that can result from non-blind administration of lineups) would reduce filler identification errors compared to unbiased and non-suggestive procedures. Hence, under many circumstances filler identification rates can be misleading indicators of preferred methods. Comparisons of lineup procedures in future field experiments will not be easily accepted in the absence of double-blind administration methods in all conditions plus true random assignment to conditions.

  17. Transport and confinement studies in the RFX-mod reversed-field pinch experiment

    International Nuclear Information System (INIS)

    Innocente, P.; Alfier, A.; Carraro, L.; Lorenzini, R.; Pasqualotto, R.; Terranova, D.

    2007-01-01

    In the modified RFX experiment (RFX-mod) external magnetic field coils and a close fitting thin conductive shell control radial magnetic fields. In the so-called virtual shell (VS) operation, radial field zeroing at the thin shell radius is stationary provided by the feedback-controlled coils. First experiments on RFX-mod proved the capability of the active scheme to steadily reduce the radial magnetic field. Furthermore it has been found that such edge magnetic field control extends its beneficial effects to the whole plasma. With respect to the old RFX, where magnetohydrodynamic modes amplitude was controlled by the use of a passive thick conductive shell, a stationary 2- to 3-fold reduction of the B r field amplitude in the core is obtained. The reduction of field fluctuations positively reflects on confinement. In fact, a strong reduction of the loop voltage is observed and correspondingly a 3-fold increase in pulse length is achieved by using the same poloidal flux swing. Temperature and particle measurements confirm the improved confinement properties of the VS operation. With a lower ohmic input power, higher electron temperature and lower particle influx are measured. Particle and heat transport have been studied by means of a 1D code. Local power balance was used to compute the heat conductivity profile: for the VS discharges a lower conductivity over a significant region of the plasma is found. The improved properties of RFX-mod VS operation provide a better confinement scaling in terms of plasma current. The results show that compared with the thick shell configuration, a significant confinement improvement can be obtained under stationary conditions by actively controlling the plasma magnetic boundary

  18. A Demonstration Experiment for the Forecast of Magnetic Field and Field Errors in the Large Hadron Collider

    CERN Document Server

    Sammut, N J; Bottura, L; Deferne, G; Lamont, M; Miles, J; Sanfilippo, S; Strzelczyk, M; Venturini-Delsolaro, W; Xydi, P

    2008-01-01

    In order to reduce the burden on the beam-based feedback, the Large Hadron Collider control system is equipped with the Field Description for the LHC (FiDeL) which provides a forecast of the magnetic field and the multipole field errors. FiDeL has recently been extensively tested at CERN to determine main field tracking, multipole forecasting and compensation accuracy. This paper describes the rationale behind the tests, the procedures employed to power the main magnets and their correctors, and finally, we present the results obtained. We also give an indication of the prediction accuracy that the system can deliver during the operation of the LHC and we discuss the implications that these will have on the machine performance.

  19. Developing the Precision Magnetic Field for the E989 Muon g{2 Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Matthias W. [Washington U., Seattle

    2017-01-01

    The experimental value of $(g\\hbox{--}2)_\\mu$ historically has been and contemporarily remains an important probe into the Standard Model and proposed extensions. Previous measurements of $(g\\hbox{--}2)_\\mu$ exhibit a persistent statistical tension with calculations using the Standard Model implying that the theory may be incomplete and constraining possible extensions. The Fermilab Muon g-2 experiment, E989, endeavors to increase the precision over previous experiments by a factor of four and probe more deeply into the tension with the Standard Model. The $(g\\hbox{--}2)_\\mu$ experimental implementation measures two spin precession frequencies defined by the magnetic field, proton precession and muon precession. The value of $(g\\hbox{--}2)_\\mu$ is derived from a relationship between the two frequencies. The precision of magnetic field measurements and the overall magnetic field uniformity achieved over the muon storage volume are then two undeniably important aspects of the e xperiment in minimizing uncertainty. The current thesis details the methods employed to achieve magnetic field goals and results of the effort.

  20. Simulating the volatilization of solvents in unsaturated soils during laboratory and field infiltration experiments

    Science.gov (United States)

    Cho, H. Jean; Jaffe, Peter R.; Smith, James A.

    1993-01-01

    This paper describes laboratory and field experiments which were conducted to study the dynamics of trichloroethylene (TCE) as it volatilized from contaminated groundwater and diffused in the presence of infiltrating water through the unsaturated soil zone to the land surface. The field experiments were conducted at the Picatinny Arsenal, which is part of the United States Geological Survey Toxic Substances Hydrology Program. In both laboratory and field settings the gas and water phase concentrations of TCE were not in equilibrium during infiltration. Gas-water mass transfer rate constants were calibrated to the experimental data using a model in which the water phase was treated as two phases: a mobile water phase and an immobile water phase. The mass transfer limitations of a volatile organic compound between the gas and liquid phases were described explicitly in the model. In the laboratory experiment the porous medium was nonsorbing, and water infiltration rates ranged from 0.076 to 0.28 cm h−1. In the field experiment the water infiltration rate was 0.34 cm h−1, and sorption onto the soil matrix was significant. The laboratory-calibrated gas-water mass transfer rate constant is 3.3×10−4 h−1 for an infiltration rate of 0.076 cm h−1 and 1.4×10−3 h−1 for an infiltration rate of 0.28 cm h−1. The overall mass transfer rate coefficients, incorporating the contribution of mass transfer between mobile and immobile water phases and the variation of interfacial area with moisture content, range from 3×10−4 h−1 to 1×10−2 h−1. A power law model relates the gas-water mass transfer rate constant to the infiltration rate and the fraction of the water phase which is mobile. It was found that the results from the laboratory experiments could not be extrapolated to the field. In order to simulate the field experiment the very slow desorption of TCE from the soil matrix was incorporated into the mathematical model. When desorption from the

  1. NOAA-9 Earth Radiation Budget Experiment (ERBE) scanner offsets determination

    Science.gov (United States)

    Avis, Lee M.; Paden, Jack; Lee, Robert B., III; Pandey, Dhirendra K.; Stassi, Joseph C.; Wilson, Robert S.; Tolson, Carol J.; Bolden, William C.

    1994-01-01

    The Earth Radiation Budget Experiment (ERBE) instruments are designed to measure the components of the radiative exchange between the Sun, Earth and space. ERBE is comprised of three spacecraft, each carrying a nearly identical set of radiometers: a three-channel narrow-field-of-view scanner, a two-channel wide-field-of-view (limb-to-limb) non-scanning radiometer, a two-channel medium field-of view (1000 km) non-scanning radiometer, and a solar monitor. Ground testing showed the scanners to be susceptible to self-generated and externally generated electromagnetic noise. This paper describes the pre-launch corrective measures taken and the post-launch corrections to the NOAA-9 scanner data. The NOAA-9 scanner has met the mission objectives in accuracy and precision, in part because of the pre-launch reductions of and post-launch data corrections for the electromagnetic noise.

  2. ADX: a high field, high power density, Advanced Divertor test eXperiment

    Science.gov (United States)

    Vieira, R.; Labombard, B.; Marmar, E.; Irby, J.; Shiraiwa, S.; Terry, J.; Wallace, G.; Whyte, D. G.; Wolfe, S.; Wukitch, S.; ADX Team

    2014-10-01

    The MIT PSFC and collaborators are proposing an advanced divertor experiment (ADX) - a tokamak specifically designed to address critical gaps in the world fusion research program on the pathway to FNSF/DEMO. This high field (6.5 tesla, 1.5 MA), high power density (P/S ~ 1.5 MW/m2) facility would utilize Alcator magnet technology to test innovative divertor concepts for next-step DT fusion devices (FNSF, DEMO) at reactor-level boundary plasma pressures and parallel heat flux densities while producing high performance core plasma conditions. The experimental platform would also test advanced lower hybrid current drive (LHCD) and ion-cyclotron range of frequency (ICRF) actuators and wave physics at the plasma densities and magnetic field strengths of a DEMO, with the unique ability to deploy launcher structures both on the low-magnetic-field side and the high-field side - a location where energetic plasma-material interactions can be controlled and wave physics is most favorable for efficient current drive, heating and flow drive. This innovative experiment would perform plasma science and technology R&D necessary to inform the conceptual development and accelerate the readiness-for-deployment of FNSF/DEMO - in a timely manner, on a cost-effective research platform. Supported by DE-FC02-99ER54512.

  3. EFEDA - European field experiment in a desertification-threatened area

    Science.gov (United States)

    Bolle, H.-J.; Andre, J.-C.; Arrue, J. L.; Barth, H. K.; Bessemoulin, P.; Brasa, A.; De Bruin, H. A. R.; Cruces, J.; Dugdale, G.; Engman, E. T.

    1993-01-01

    During June 1991 more than 30 scientific teams worked in Castilla-La Mancha, Spain, studying the energy and water transfer processes between soil, vegetation, and the atmosphere in semiarid conditions within the coordinated European research project EFEDA (European Field Experiment in Desertification-threatened Areas). Measurements were made from the microscale (e.g., measurements on single plants) up to a scale compatible with the grid size of global models. For this purpose three sites were selected 70 km apart and heavily instrumented at a scale in the order of 30 sq km. Aircraft missions, satellite data, and movable equipment were deployed to provide a bridge to the larger scale. This paper gives a description of the experimental design along with some of the preliminary results of this successful experiment.

  4. On Storks and Babies: Correlation, Causality and Field Experiments

    Directory of Open Access Journals (Sweden)

    Lambrecht Anja

    2016-11-01

    Full Text Available The explosion of available data has created much excitement among marketing practitioners about their ability to better understand the impact of marketing investments. Big data allows for detecting patterns and often it seems plausible to interpret them as causal. While it is quite obvious that storks do not bring babies, marketing relationships are usually less clear. Apparent “causalities” often fail to hold up under examination. If marketers want to be sure not to walk into a causality trap, they need to conduct field experiments to detect true causal relationships. In the present digital environment, experiments are easier than ever to execute. However, they need to be prepared and interpreted with great care in order to deliver meaningful and genuinely causal results that help improve marketing decisions.

  5. Urban Field Experiences for Undergraduate Liberal Arts Students: Using Compromised Environments as Living Laboratories

    Science.gov (United States)

    MacAvoy, S. E.; Knee, K.

    2015-12-01

    While urban environments may lack the beauty of relatively pristine field sites, they can be used to deliver an effective demonstration of actual environmental damage. Students demanding applied field experiences from their undergraduate environmental science programs can be well served in urban settings. Here, we present strategies for integrating degraded urban systems into the undergraduate field experience. Urban locations provide an opportunity for a different type of local "field-work" than would otherwise be available. In the upper-level undergraduate Environmental Methods class, we relied on a National Park area located a 10-minute walk from campus for most field exercises. Activities included soil analysis, measuring stream flow and water quality parameters, dendrochronology, and aquatic microbe metabolism. In the non-majors class, we make use of our urban location to contrast water quality in parks and highly channelized urban streams. Students spend labs immersed in streams and wetlands heavily impacted by the urban runoff their city generates. Here we share lesson plans and budgets for field activities that can be completed during a class period of 2.5 hours with a $75 course fee, show how these activities help students gain quantitative competency.

  6. Paleomagnetism in the Determination of the Emplacement Temperature of Cerro Colorado Tuff Cone, El Pinacate Volcanic Field, Sonora, Mexico.

    Science.gov (United States)

    Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Vidal Solano, J. R.; Garcia Amador, B.; Gonzalez-Rangel, J. A.

    2014-12-01

    Cerro Colorado Maar is located at the World Heritage Site, biosphere reserve El Pinacate and Gran Desierto del Altar, at the NNW region of Sonora, Mexico (in El Pinacate Volcanic Field). It is a tuff cone, about 1 km diameter, result of several phreatomagmatic episodes during the late Quaternary. We report paleomagnetic and rock magnetic properties from fusiform volcanic bombs obtained from the borders of Cerro Colorado. This study is based in the thermoremanent magnetization TRM normally acquired by volcanic rocks, which can be used to estimate the emplacement temperature range. We performed the experiments on 20 lithic fragments (10 cm to 20 cm approximately), taking 6-8 paleomagnetic cores from each. Rock magnetic experiments (magnetic susceptibility vs. temperature (k-T), hysteresis curves and FORC analysis, shows that the main magnetic mineral carriers of magnetization are titanomagnetite and titanohematite in different levels of intergrowth. The k-T curves suggest in many cases, only one magnetic phase, but also in other cases a second magnetic phase. Thermal demagnetization was used to demagnetize the specimens in detailed short steps and make a well-defined emplacement temperature determination ranges. We found that temperature emplacement determination range for these two magnetic phases is between 350-450 °C, and 550-580 °C, respectively. These results are consistent with those expected in an eruption of Surtsey type, showing a distinct volcanic activity compared to the other craters from El Pinacate volcanic field.

  7. Early Pottery Making in Northern Coastal Peru. Part II: Field Firing Experiments

    International Nuclear Information System (INIS)

    Shimada, I.; Goldstein, D.; Sosa, J.; Wagner, U.

    2003-01-01

    We present data from three seasons of experimental field work designed to recreate ancient Andean coastal ceramic firing techniques. Based on the recent discovery of two different archaeological ceramic production sites in the La Leche river valley of northern coastal Peru, the opportunity arose to apply Moessbauer spectroscopy and other analytical methods to reconstruct ancient firing procedures. Two sets of firings took place in 1993 and 1997 in Batan Grande using a partially restored Formative kiln from about 800 BC, local hardwood and cow dung as fuel. A third experiment followed in 2000 after the discovery of a Middle Sican ceramics workshop in use between ca. AD 950 and 1050 at Huaca Sialupe, where an exact replica of an ancient kiln was built from local clay, and fired with local wood and cow dung. Additionally, inverted urns found at Huaca Sialupe were tested for their potential use as furnaces for metal working. Moessbauer spectroscopy was used to compare the physical and chemical state of specimens produced in the field experiments with ancient ceramics and with specimens produced in controlled laboratory experiments.

  8. Developing Standards-Based Geography Curricular Materials from Overseas Field Experiences for K-12 Teachers

    Science.gov (United States)

    Oberle, Alex; Palacios, Fabian Araya

    2012-01-01

    Overseas experiences provide educators with exceptional opportunities to incorporate field study, firsthand experiences, and tangible artifacts into the classroom. Despite this potential, teachers must consider curricular standards that direct how such international endeavors can be integrated. Furthermore, geography curriculum development is more…

  9. Electric field determination in streamer discharges in air at atmospheric pressure

    International Nuclear Information System (INIS)

    Bonaventura, Z; Bourdon, A; Celestin, S; Pasko, V P

    2011-01-01

    The electric field in streamer discharges in air can be easily determined by the ratio of luminous intensities emitted by N 2 (C 3 Π u ) and N 2 + (B 2 Σ u + ) if the steady-state assumption of the emitting states is fully justified. At ground pressure, the steady-state condition is not fulfilled and it is demonstrated that its direct use to determine the local and instantaneous peak electric field in the streamer head may overestimate this field by a factor of 2. However, when spatial and time-integrated optical emissions (OEs) are considered, the reported results show that it is possible to formulate a correction factor in the framework of the steady-state approximation and to accurately determine the peak electric field in an air discharge at atmospheric pressure. A correction factor is defined as Γ = E s /E e , where E e is the estimated electric field and E s is the true peak electric field in the streamer head. It is shown that this correction stems from (i) the shift between the location of the peak electric field and the maximum excitation rate for N 2 (C 3 Π u ) and N 2 + (B 2 Σ u + ) as proposed by Naidis (2009 Phys. Rev. E 79 057401) and (ii) from the cylindrical geometry of the streamers as stated by Celestin and Pasko (2010 Geophys. Res. Lett. 37 L07804). For instantaneous OEs integrated over the whole radiating plasma volume, a correction factor of Γ ∼ 1.4 has to be used. For time-integrated OEs, the reported results show that the ratio of intensities can be used to derive the electric field in discharges if the time of integration is sufficiently long (i.e. at least longer than the longest characteristic lifetime of excited species) to have the time to collect all the light from the emitting zones of the streamer. For OEs recorded using slits (i.e. a window with a small width but a sufficiently large radial extension to contain the total radial extension of the discharge) the calculated correction factor is Γ ∼ 1.4. As for OEs observed

  10. Determination of dosimetric parameters of Asymmetric fields from those of Symmetric fields for equinox 100 Cobalt-60 teletherapy machine

    International Nuclear Information System (INIS)

    Mensah, K.

    2014-07-01

    The Theratron Equinox 100 Cobalt-60 therapy unit is equipped wtih x-ray collimators or jaws that can be moved independently or allow asymmetric fields with field centres positioned away from the true central axis of the beam. Although asymmetric collimation can be performed by beam splitters or secondary blocking on a shadow tray; an independent jaw feature reduces the set-up time and spares the therapist from handling heavy blocks. Clinical sites where asymmetric jaws are typically used include breast, head and neck, craniospinal and prostate. Knowledge of the dose distribution of asymmetric fields is required to help evaluate the dosimetry of this non-standard treatment delivery technique prior to clinical implementation. IBA StarTrack 2-D array was used to acquire beam profiles of symmetric and asymmetric beams of different field sizes and varying depth using the Theratron Equinox 100 Cobalt-60 teletherapy unit. The 2-D water phantom was then used to measure PDDs and output factors of both the symmetric and asymmetric beams at varying depths and field sizes. The off-axis ratio was also determined from the half beam profile of the largest field size of the treatment machine and then the output factor ratios were used to validate it. The treatment planning system was then used to model both the symmetric and asymmetic beams and the PDDs and output factors were also calculated. Beam profiles for asymmetry beams showed good agreement with symmetry beam profiles for smaller field sizes and the deviations among them steadily became more evident with increasing field sizes. This difference in the dose distribution for asymmetric fields compared to the dose distribution for symmetric fields was due to the tilt of the dose profiles towards the beam axis. This tilt in the dose profiles of the asymmetic beams was caused by the oblique incidence of the asymmetric beam at off-axis locations, causing less beam hardening compared to that along the central axis. In treatment

  11. Shallow lunar structure determined from the passive seismic experiment

    International Nuclear Information System (INIS)

    Nakamura, Y.; Dorman, J.; Duennebier, F.; Lammlein, D.; Latham, G.

    1975-01-01

    Data relevant to the shallow structure of the Moon obtained at the Apollo seismic stations are compared with previously published results of the active seismic experiments. It is concluded that the lunar surface is covered by a layer of low seismic velocity (Vsub(p) approximately equal to 100 ms -1 ), which appears to be equivalent to the lunar regolith defined previously by geological observations. This layer is underlain by a zone of distinctly higher seismic velocity at all of the Apollo landing sites. The regolith thicknesses at the Apollo 11, 12, and 15 sites are estimated from the shear-wave resonance to be 4.4, 3.7, and 4.4m, respectively. These thicknesses and those determined at the other Apollo sites by the active seismic experiments appear to be correlated with the age determinations and the abundances of extra-lunar components at the sites. (Auth.)

  12. A Classroom Experiment on Exchange Rate Determination with Purchasing Power Parity

    Science.gov (United States)

    Mitchell, David T.; Rebelein, Robert P.; Schneider, Patricia H.; Simpson, Nicole B.; Fisher, Eric

    2009-01-01

    The authors developed a classroom experiment on exchange rate determination appropriate for undergraduate courses in macroeconomics and international economics. In the experiment, students represent citizens from different countries and need to obtain currency to purchase goods. By participating in an auction to buy currency, students gain a…

  13. Field work in geography. Region with experience in socio-environmental conflicts

    Directory of Open Access Journals (Sweden)

    Beatriz Ensabella

    2016-07-01

    Full Text Available This article emphasizes the importance of the geographical field work in a region with socio-environmental conflict, such us the problem with water in Sierras Chicas, Cordoba. The main focus is a pedagogical experience, the Socio-Communal Practice (SCP, performed by professors, students and assistants of the subject Rural Geography, of the Bachelor’s in Geography course of studies of the Philosophy and Humanity School (PHS, in the city of La Granja, in Colón, Córdoba. The SCP is an experience that makes the students approach the social field of the territory conflicts. It is an activity that goes beyond the extension project, since it involves all the students doing the subject. And it is also a way to combine -in our case, from the geographic work- the teaching, investigation and extension functions typical of the university students. Through the SCP, we aim to make the Rural Geography students approach the field work, with local social organizations that deeply know the problems of their cities and that work together with our investigation group. In addition, this contact together with the individual thoughts, the group discussion and the debates between the university students, will broaden, in the whole society, the knowledge about the reality in which they live and with which they struggle. This article starts by defining what it is understood by SCP. Then, taking into account our practice, we develop what we consider to be the two logics that support the field work. One refers to the building of knowledge and to the different ways of learning and knowing. The other is related to the understanding of the socio-territory conflict in the area where the practice will be done: the Mesa del Agua and La Granja environment. We include a section about the description of the experience and its results, and we conclude with some reflections made taking into account the continuity of the practice

  14. Subcriticality determination in ADS: Valina-Booster experiments

    International Nuclear Information System (INIS)

    Persson, C. M.; Gudowski, W.; Fokau, A.; Bournos, V.; Fokov, Y.; Routkovskaia, C.; Serafimovich, I.; Kiyavitskaya, H.

    2007-01-01

    A major problem in operating a full-scale subcritical accelerator-driven system (ADS) is to ensure sufficient margin to criticality. Therefore, reliable techniques for subcriticality monitoring are required. In order to develop such techniques, a full understanding of existing reactivity determination methods is essential. In this work, reactivity determination methods, such as pulsed neutron source methods and noise methods, are studied experimentally in the subcritical facility YALINA-Booster. YALINA-Booster: The subcritical assembly YALINA-Booster: recently constructed at the Joint Institute for Power and Nuclear Research - Sosny, consists of a subcritical core driven by an external neutron source. The neutron source is a powerful neutron generator consisting of a deuteron accelerator and a target of deuterium or tritium embedded in titanium. Through (d, d) - or (d, t)-reactions neutrons are created with energy around 2.5 MeV and 14.1 MeV respectively. Neutrons are born in the centre of the core and multiply through a lead matrix fuelled with highly enriched uranium (90% and 36%). This zone is referred to as the booster zone and is surrounded by a thermal zone, moderated by polyethylene. In order to reach sufficient high effective multiplication factor, the thermal zone is fuelled by approximately one thousand rods of 10% enriched uranium dioxide in cylindrical geometry. To prevent thermal neutrons from diffusing into the fast booster zone, an interface, consisting of boron carbide and natural uranium rods, is located between the zones. YALINA-Booster has a radial graphite reflector of thickness 24 cm. Experiments: Experiments using the neutron source in pulsed mode will be presented, relying on methods such as the area method and the method of prompt neutron decay rate determination. Moreover, results from noise analysis using for instance the Feynman-α method will be presented

  15. Magnetic-field-dependent microwave absorption in HgSe in weak magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Veinger, A. I., E-mail: Anatoly.Veinger@mail.ioffe.ru; Tisnek, T. V.; Kochman, I. V. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation); Okulov, V. I. [Russian Academy of Sciences, Ural Branch, Mikheev Institute of Metal Physics (Russian Federation)

    2017-02-15

    The low-temperature magnetoresistive effect in the semiconductor HgSe:Fe in weak magnetic fields at microwave frequencies is examined. The negative and positive components of magnetoabsorption based on the magnetoresistive effect in the degenerate conduction band are analyzed. The special features of experiments carried out in the investigated frequency range are noted. The momentum and electron-energy relaxation times are determined from the experimental field and temperature dependences.

  16. Design of Field Experiments for Adaptive Sampling of the Ocean with Autonomous Vehicles

    Science.gov (United States)

    Zheng, H.; Ooi, B. H.; Cho, W.; Dao, M. H.; Tkalich, P.; Patrikalakis, N. M.

    2010-05-01

    Due to the highly non-linear and dynamical nature of oceanic phenomena, the predictive capability of various ocean models depends on the availability of operational data. A practical method to improve the accuracy of the ocean forecast is to use a data assimilation methodology to combine in-situ measured and remotely acquired data with numerical forecast models of the physical environment. Autonomous surface and underwater vehicles with various sensors are economic and efficient tools for exploring and sampling the ocean for data assimilation; however there is an energy limitation to such vehicles, and thus effective resource allocation for adaptive sampling is required to optimize the efficiency of exploration. In this paper, we use physical oceanography forecasts of the coastal zone of Singapore for the design of a set of field experiments to acquire useful data for model calibration and data assimilation. The design process of our experiments relied on the oceanography forecast including the current speed, its gradient, and vorticity in a given region of interest for which permits for field experiments could be obtained and for time intervals that correspond to strong tidal currents. Based on these maps, resources available to our experimental team, including Autonomous Surface Craft (ASC) are allocated so as to capture the oceanic features that result from jets and vortices behind bluff bodies (e.g., islands) in the tidal current. Results are summarized from this resource allocation process and field experiments conducted in January 2009.

  17. Self-determination and goal orientation in track and field.

    Science.gov (United States)

    Chin, Ngien-Siong; Khoo, Selina; Low, Wah-Yun

    2012-06-01

    This study investigated gender, age group and locality differences in adolescent athletes' self-determination motivation and goal orientations in track and field. It also examined the relationship between the self-determination theory and achievement goal theory. A total of 632 (349 boys, 283 girls) adolescent athletes (aged 13-18 years) completed the Sports Motivation Scale and Task and Ego Orientation in Sport Questionnaire. Results indicated significant differences between gender on intrinsic motivation, extrinsic motivation, amotivation (t(630) = 4.10, p amotivation and ego orientation. A significant difference was found between age groups on task orientation (t(630) = 1.94, p amotivation (r = 0.10, p amotivation accounted for 30.5% of the variances in task orientation.

  18. Development of a summer field-based hydrogeology research experience for undergraduates

    Science.gov (United States)

    Singha, K.

    2011-12-01

    A critical problem in motivating and training the next generation of environmental scientists is providing them with an integrated scientific experience that fosters a depth of understanding and helps them build a network of colleagues for their future. As the education part of an NSF-funded CAREER proposal, I have developed a three-week summer research experience for undergraduate students that links their classroom education with field campaigns aiming to make partial differential equations come "alive" in a practical, applied setting focused on hydrogeologic processes. This course has been offered to freshman- to junior-level undergraduate students from Penn State and also the three co-operating Historically Black Universities (HBUs)--Jackson State University, Fort Valley State University, and Elizabeth City State University-since 2009. Broad learning objectives include applying their knowledge of mathematics, science, and engineering to flow and transport processes in the field and communicating science effectively in poster and oral format. In conjunction with ongoing research about solute transport, students collected field data in the Shale Hills Critical Zone Observatory in Central Pennsylvania, including slug and pumping tests, ground-penetrating radar, electrical resistivity imaging, wireline logging, and optical televiewers, among other instruments. Students conducted tracer tests, where conservative solutes are introduced into a local stream and monitored. Students also constructed numerical models using COMSOL Multiphysics, a research-grade code that can be used to model any physical system; with COMSOL, students create models without needing to be trained in computer coding. With guidance, students built basic models of fluid flow and transport to visualize how heterogeneity of hydraulic and transport properties or variations in forcing functions impact their results. The development of numerical models promoted confidence in predicting flow and

  19. ASPI experiment: measurements of fields and waves on board the INTERBALL-1 spacecraft

    Directory of Open Access Journals (Sweden)

    S. Klimov

    1997-05-01

    Full Text Available The plasma-wave experiment ASPI (analysis of spectra of plasma waves and instabilities on board the INTERBALL spacecraft is a combined wave diagnostics experiment. It performs measurements of the DC and AC magnetic field vector by flux-gate and search-coil sensors, the DC and AC electric field vector by Langmuir double probes and the plasma current by Langmuir split probe. Preliminary data analysis shows the low noise levels of the sensors and the compatibility of new data with the results of previous missions. During several months of in-orbit operation a rich collection of data was acquired, examples of which at the magnetopause and plasma sheet are presented in second part of the paper.

  20. Distribution of Phytophthora spp. in Field Soils Determined by Immunoassay.

    Science.gov (United States)

    Miller, S A; Madden, L V; Schmitthenner, A F

    1997-01-01

    ABSTRACT Populations of Phytophthora spp. were determined by enzyme-linked immunosorbent assay (ELISA) in field soils used for pepper and soybean production in Ohio. Soybean fields were sampled extensively (64 fields, n = 6 samples per field over 2 years) and intensively (4 fields, n = 64 samples per field in 1 year) to assess heterogeneity of P. sojae populations. Four pepper fields (n = 64), three of which had a history of Phytophthora blight (caused by P. capsici), also were sampled intensively during a 6-month period. Mean (m), variance (v), and measures of aggregation (e.g., variance-to-mean ratio [v/m]) of immunoassay values, translated to Phytophthora antigen units (PAU), were related to the disease history in each of the pepper and soybean fields. Mean PAU values for fields in which Phytophthora root rot (soybean) or blight (pepper) had been moderate to severe were higher than in fields in which disease incidence had been low or not observed. A detection threshold value of 11.3 PAU was calculated with values for 64 samples from one pepper field, all of which tested negative for Phytophthora by bioassay and ELISA. Seven of the eight intensively sampled fields contained at least some detectable Phytophthora propagules, with the percentage of positive samples ranging from 1.6 to 73.4. Mean PAU values ranged from 1 to 84 (extensive soybean field sampling), 6 to 24 (intensive soybean field sampling), and 4 to 30 (intensive pepper field sampling); however, variances ranged from 0 to 7,774 (extensive sampling), 30 to 848 (intensive soybean field sampling), and 5 to 2,401 (intensive pepper field sampling). Heterogeneity of PAU was high in most individual soybean and pepper fields, with values of v/m greater than 1, and log(v) increasing with log(m), with a slope of about 2.0. Spatial autocorrelation coefficients were not significant, indicating there was no relationship of PAU values in neighboring sampling units (i.e., field locations) of the intensively sampled

  1. The importance of holdup in contracting: Evidence from a field experiment

    NARCIS (Netherlands)

    Iyer, R.; Schoar, A.

    2008-01-01

    This paper explores how the relationship specificity of the investment affects the ex-ante structure of contracts and the ex-post resolution of an ensuing holdup problem. We set up a field experiment in the wholesale market for pens in India where we sent entrepreneurs as auditors to procure large

  2. Cultural adaptation in translational research: field experiences.

    Science.gov (United States)

    Dévieux, Jessy G; Malow, Robert M; Rosenberg, Rhonda; Jean-Gilles, Michèle; Samuels, Deanne; Ergon-Pérez, Emma; Jacobs, Robin

    2005-06-01

    The increase in the incidence of HIV/AIDS among minorities in the United States and in certain developing nations has prompted new intervention priorities, stressing the adaptation of efficacious interventions for diverse and marginalized groups. The experiences of Florida International University's AIDS Prevention Program in translating HIV primary and secondary prevention interventions among these multicultural populations provide insight into the process of cultural adaptations and address the new scientific emphasis on ecological validity. An iterative process involving forward and backward translation, a cultural linguistic committee, focus group discussions, documentation of project procedures, and consultations with other researchers in the field was used to modify interventions. This article presents strategies used to ensure fidelity in implementing the efficacious core components of evidence-based interventions for reducing HIV transmission and drug use behaviors and the challenges posed by making cultural adaptation for participants with low literacy. This experience demonstrates the importance of integrating culturally relevant material in the translation process with intense focus on language and nuance. The process must ensure that the level of intervention is appropriate for the educational level of participants. Furthermore, the rights of participants must be protected during consenting procedures by instituting policies that recognize the socioeconomic, educational, and systemic pressures to participate in research.

  3. Constraining chameleon field theories using the GammeV afterglow experiments

    International Nuclear Information System (INIS)

    Upadhye, A.; Steffen, J.H.; Weltman, A.

    2009-01-01

    The GammeV experiment has constrained the couplings of chameleon scalar fields to matter and photons. Here we present a detailed calculation of the chameleon afterglow rate underlying these constraints. The dependence of GammeV constraints on various assumptions in the calculation is studied. We discuss GammeV-CHASE, a second-generation GammeV experiment, which will improve upon GammeV in several major ways. Using our calculation of the chameleon afterglow rate, we forecast model-independent constraints achievable by GammeV-CHASE. We then apply these constraints to a variety of chameleon models, including quartic chameleons and chameleon dark energy models. The new experiment will be able to probe a large region of parameter space that is beyond the reach of current tests, such as fifth force searches, constraints on the dimming of distant astrophysical objects, and bounds on the variation of the fine structure constant.

  4. Determination of the bending field integral of the LEP spectrometer dipole

    International Nuclear Information System (INIS)

    Chritin, R.; Cornuet, D.; Dehning, B.; Hidalgo, A.; Hildreth, M.; Kalbreier, W.; Leclere, P.; Mugnai, G.; Palacios, J.; Roncarolo, F.; Torrence, E.; Wilkinson, G.

    2005-01-01

    The LEP spectrometer performed calibrations of the beam energy in the 2000 LEP run, in order to provide a kinematical constraint for the W boson mass measurement. The beam was deflected in the spectrometer by a steel core dipole, and the bending angle was measured by Beam-Position Monitors on either side of the magnet. The energy determination relies on measuring the change in bending angle when ramping the beam from a reference point at 50GeV to an energy within the LEP W physics regime, typically 93GeV. The ratio of integrated bending fields at these settings (approximately 1.18Tm/0.64Tm) must be known with a precision of a few 10 -5 . The paper reports on the field mapping measurements which were conducted to determine the bending integral under a range of excitation currents and coil temperatures. These were made in the laboratory before and after spectrometer operation, using a test-bench equipped with a moving arm, carrying an NMR probe and Hall probes, and in the LEP tunnel itself, with a mapping trolley inside the vacuum chamber. The mapping data are related to local readings supplied by fixed NMR probes in the dipole, and a predictive model developed which shows good consistency for all datasets within the estimated uncertainty, which is 14x10 -5 for the moving arm, and 3x10 -5 for the mapping trolley. Measurements are also presented of the field gradient inside the dipole, and of the environmental magnetic fields in the LEP tunnel. When applied to the spectrometer energy calibrations, the bending field model calculates the ratio of integrated fields with an estimated uncertainty of 1.5x10 -5

  5. Too poor to be green consumers? A field experiment on revealed preferences for firewood in rural Guatemala

    International Nuclear Information System (INIS)

    Van Kempen, Luuk; Muradian, Roldan; Sandoval, Cesar; Castaneda, Juan-Pablo

    2009-01-01

    The paper reports on a field experiment that investigates whether households in Guatemala are willing to surrender a small material gain in order to buy legal rather than illegal firewood. Given the ineffectiveness of command-and-control policies to curb the problem of illegal logging in Guatemala, the experiment assesses the potential viability of market-oriented solutions. Local consumers in developing countries are generally believed to be too poor to pay a premium for green/ethical products. Therefore, little information has been gathered on willingness-to-pay (WTP) for such products and its determinants in non-affluent consumer markets. While our experiment on firewood consumption in central Guatemala only implies a weak and indirect test of WTP for green products, the results indicate that it is premature, if not unwarranted, to assume that the poor are not ready to make pro-ethical choices in the marketplace. Moreover, we find that information on the legal procedures for firewood extraction significantly affects consumer choice between legal and illegal firewood. (author)

  6. A field experiment on power line stabilization by SMES system

    International Nuclear Information System (INIS)

    Irie, F.; Takeo, M.; Sato, S.; Katahira, O.; Fukui, F.; Takamatsu, M.

    1992-01-01

    In this paper field experiments on stabilization of a hydro power plant by a SMES system are reported, where a generator having a rating of 60 kW at 3.3kV is connected to a 6.6kV power distribution line. The SMES system is composed of two 30kVA GTO convertors and a superconducting magnet system with an energy of 30kJ at 100A. Experiments of stabilization for the generator fluctuation caused by a sudden insertion of inductors in the line are successfully performed for some control modes. The value of the SMES system to compensate for a short period voltage dip is also confirmed

  7. Determination of polarization fields in group III-nitride heterostructures by capacitance-voltage-measurements

    Energy Technology Data Exchange (ETDEWEB)

    Rychetsky, Monir, E-mail: monir.rychetsky@physik.tu-berlin.de; Avinc, Baran; Wernicke, Tim; Bellmann, Konrad; Sulmoni, Luca [Institute of Solid State Physics, Technische Universität Berlin, Berlin (Germany); Koslow, Ingrid; Rass, Jens; Kneissl, Michael [Institute of Solid State Physics, Technische Universität Berlin, Berlin (Germany); Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Berlin (Germany); Hoffmann, Veit; Weyers, Markus [Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Berlin (Germany); Wild, Johannes; Zweck, Josef [Fakultät für Physik, University of Regensburg, Regensburg (Germany); Witzigmann, Bernd [Computational Electronics and Photonics Group and CINSaT, University of Kassel, Kassel (Germany)

    2016-03-07

    The polarization fields in wurtzite group III-nitrides strongly influence the optical properties of InAlGaN-based light emitters, e.g., the electron and hole wave function overlap in quantum wells. In this paper, we propose a new approach to determine these fields by capacitance-voltage measurements (CVM). Sheet charges generated by a change of the microscopic polarization at heterointerfaces influence the charge distribution in PIN junctions and therefore the depletion width and the capacitance. We show that it is possible to determine the strength and direction of the internal fields by comparing the depletion widths of two PIN junctions, one influenced by internal polarization fields and one without as a reference. For comparison, we conducted coupled Poisson/carrier transport simulations on the CVM of the polarization-influenced sample. We also demonstrate the feasibility and limits of the method by determining the fields in GaN/InGaN and GaN/AlGaN double heterostructures on (0001) c-plane grown by metal organic vapor phase epitaxy and compare both evaluation methods. The method yields (−0.50 ± 0.07) MV/cm for In{sub 0.08}Ga{sub 0.92}N/GaN, (0.90 ± 0.13) MV/cm for Al{sub 0.18}Ga{sub 0.82}N/GaN, and (2.0 ± 0.3) MV/cm for Al{sub 0.31}Ga{sub 0.69}N/GaN heterostructures.

  8. Nanojets, Electrospray, and Ion Field Evaporation: Molecular Dynamics Simulations and Laboratory Experiments

    National Research Council Canada - National Science Library

    Luedtke, W. D; Landman, Uzi; Chiu, Y. H; Levandier, D. J; Dressler, R. A; Sok, S; Gordon, M. S

    2008-01-01

    ... experiment and using molecular dynamics (MD) simulations. The electrospray source is operated in a Taylor cone-jet mode, with the nanojet that forms being characterized by high surface-normal electric field strengths in the vicinity of I V/nm...

  9. Incineration in the nuclear field. The SGN experience

    International Nuclear Information System (INIS)

    Carpentier, S.

    1993-01-01

    The operation of power reactors, like that of fuel fabrication and nuclear fuel reprocessing plants, generated substantial quantities of waste. A large share of this waste is low- and medium-level waste, which is also combustible. Similarly, a number of institutes, laboratories, and hospitals, in the course of their activities, generated waste which a portion is radioactive and combustible. The chief advantage of incineration is to minimize the volume of burnable waste treated, and to produce a residue termed 'ash'. SGN has built up 25 years of experience in this field. The incinerators have been designed and the incineration processes are specially studied by SGN

  10. Review of possible experiments in the eutectic growth and thermodiffusion fields

    International Nuclear Information System (INIS)

    Malmejac, Yves.

    1976-01-01

    The results now available from the SKYLAB and ASTP programmes give a clearer indication of the lines of the research to pursue in the years to come. The criteria necessary for the choice of experiments are analysed in the fields of eutectic solidification and diffusion along a temperature gradient in liquid alloys [fr

  11. The Preservice Teachers Are Watching: Framing and Reframing the Field Experience

    Science.gov (United States)

    Scherff, Lisa; Singer, Nancy Robb

    2012-01-01

    In this article we employ Sizers' (1999) school- and classroom-based lenses for observation and apply them to the events and interactions that teacher education students see during school-based field experiences. Our data include online reflections and discussions among 33 students enrolled in a teacher education program at a large, public…

  12. Magnetic Field Design for the LANL nEDM Experiment

    Science.gov (United States)

    Dadisman, Ryan

    2017-09-01

    A recent UCN source upgrade at LANSCE makes possible an order of magnitude advancement in the measurement of the neutron electric dipole moment by use of the familiar Ramsey method of separated oscillatory fields. A highly uniform B0 magnetic field is required to achieve sufficiently long spin-relaxation times and to suppress the false EDM caused by the geometric phase effect. We identified a multi-gap solenoid as an ideal candidate to simultaneously achieve the uniformity requirements, via optimization of the gap lengths between and current within different sections, and provide plentiful access to the fiducial region. Results from initial tests of the coil when installed in the magnetic shield house enclosing the experiment will be presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-SC-0014622.

  13. Magnetic resonance electrical impedance tomography for determining electric field distribution during electroporation

    International Nuclear Information System (INIS)

    Kranjc, Matej; Miklavcic, Damijan; Bajd, Franci; Serša, Igor

    2013-01-01

    Electroporation is a phenomenon caused by externally applied electric field to cells that results in an increase of cell membrane permeability to various molecules. Accurate coverage of the tissue with a sufficiently large electric field presents one of the most important conditions for successful membrane permeabilization. Applications based on electroporation would greatly benefit with a method for monitoring the electric field, especially if it could be done in situ. As the membrane electroporation is a consequence of an induced transmembrane potential, which is directly proportional to the local electric field, we have been investigating current density imaging and magnetic resonance electrical impedance tomography techniques to determine the electric field distribution during electroporation. In this paper, we present comparison of current density and electric field distribution in an agar phantom and in a liver tissue exposed to electroporation pulses. As expected, a region of increased electrical conductivity was observed in the liver tissue exposed to sufficiently high electric field but not in agar phantom.

  14. Success-Breeds-Success in Collective Political Behavior: Evidence from a Field Experiment

    NARCIS (Netherlands)

    Van De Rijt, Arnout; Akin, Idil; Willer, Robb; Feinberg, Matthew

    2016-01-01

    Scholars have proposed that the emergence of political movements is highly pathdependent, such that early mobilization successes may lead to disproportionately greater eventual success. This article replicates a unique field experiment testing for positive feedback in internet petition signing (van

  15. Reversed field pinch experiments

    International Nuclear Information System (INIS)

    Roberston, S.

    1991-05-01

    The Reversatron RFP is usually operated with toroidal field windings which are a continuous helix of 144 turns. These windings produce a poloidal current which is uniform around the torus. The distribution of current is fixed by the geometry so that the applied field has only an m = 0, n = 0 component. The windings cannot act to stabilize an m = 0 mode with |n| > 0 or any m = 1 mode because these modes will excite no current in the windings. It has recently been suggested that parallel connected field coils might act as a shell by forcing the flux within each winding to be the same. Coils connected in parallel must have the same voltage at their terminals and thus must enclose the same volt-seconds or flux. Data from ZT-40 show that the discharges are more quiescent when parallel or series-parallel connected windings are used

  16. Status of neutrino mass experiments

    International Nuclear Information System (INIS)

    Fackler, O.

    1985-01-01

    In 1980 two experiments ignited a fertile field of research - the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily the author discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. Section I begins with a discussion of astronomical and terrestrial observations which motivated these experiments. In Section II, the author quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other paper. The author continues by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations are reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks

  17. Field experiments for student learning – what I learnt in my first weeks in Sweden two decades ago

    Science.gov (United States)

    Seibert, Jan

    2015-04-01

    Field experiments can be extremely valuable for obtaining a good understanding of hydrological processes. In this poster I revisit a field course held by Allan Rodhe when I came to Sweden two decades ago, and ask myself, with a long-term perspective, what I learnt during this course. Some of the experiments are described in more detail such as the estimation of hydraulic conductivities based on groundwater salt dilution and an experiment to demonstrate the difference between flood-wave velocity and water particle velocity. Furthermore, some general thoughts on challenges to generate a good learning environment in the field are given based on my personal experiences as a student, an assistant and a teacher.

  18. Improvement of RFX performances by field and impurity control

    International Nuclear Information System (INIS)

    Buffa, A.; Gnesotto, F.

    1995-01-01

    The Reverse Field Pinch experiment RFX has been operated since 1992 with the principal objective of extending the knowledge of RFP confinement to larger dimensions and higher plasma currents. Experiments have been run between 500 and 900 kA; confinement parameters are mainly determined by magnetic field quality and plasma density behavior. Significant improvements were obtained by feedback controlling the poloidal field configuration and by reducing the impurities produced by plasma-wall interactions

  19. Supine Craniospinal Irradiation Using Intrafractional Junction Shifts and Field-in-Field Dose Shaping: Early Experience at Methodist Hospital

    International Nuclear Information System (INIS)

    South, Michael C.; Chiu, J. Kam; Teh, Bin S.; Bloch, Charles; Schroeder, Thomas M.; Paulino, Arnold C.

    2008-01-01

    Purpose: To describe our preliminary experience with supine craniospinal irradiation. The advantages of the supine position for craniospinal irradiation include patient comfort, easier access to maintain an airway for anesthesia, and reduced variability of the head tilt in the face mask. Methods and Materials: The cranial fields were treated with near lateral fields and a table angle to match their divergence to the superior edge of the spinal field. The collimator was rotated to match the divergence from the superior spinal field. The spinal fields were treated using a source to surface distance (SSD) technique with the couch top at 100 cm. When a second spinal field was required, the table and collimator were rotated 90 o to allow for the use of the multileaf collimator and so the gantry could be rotated to match the divergence of the superior spinal field. The multileaf collimator was used for daily dynamic featherings and field-in-field dose control. Results: With a median follow-up of 20.2 months, five documented failures and no cases of radiation myelitis occurred in 23 consecutive patients. No failures occurred in the junctions of the spine-spine or brain-spine fields. Two failures occurred in the primary site alone, two in the spinal axis alone, and one primary site failure plus distant metastasis. The median time to recurrence was 17 months. Conclusion: The results of our study have shown that supine approach for delivering craniospinal irradiation is not associated with increased relapses at the field junctions. To date, no cases of radiation myelitis have developed

  20. Spatial correlations and probability density function of the phase difference in a developed speckle-field: numerical and natural experiments

    International Nuclear Information System (INIS)

    Mysina, N Yu; Maksimova, L A; Ryabukho, V P; Gorbatenko, B B

    2015-01-01

    Investigated are statistical properties of the phase difference of oscillations in speckle-fields at two points in the far-field diffraction region, with different shapes of the scatterer aperture. Statistical and spatial nonuniformity of the probability density function of the field phase difference is established. Numerical experiments show that, for the speckle-fields with an oscillating alternating-sign transverse correlation function, a significant nonuniformity of the probability density function of the phase difference in the correlation region of the field complex amplitude, with the most probable values 0 and p, is observed. A natural statistical interference experiment using Young diagrams has confirmed the results of numerical experiments. (laser applications and other topics in quantum electronics)

  1. Pyranometer offsets triggered by ambient meteorology: insights from laboratory and field experiments

    Science.gov (United States)

    Oswald, Sandro M.; Pietsch, Helga; Baumgartner, Dietmar J.; Weihs, Philipp; Rieder, Harald E.

    2017-03-01

    This study investigates the effects of ambient meteorology on the accuracy of radiation (R) measurements performed with pyranometers contained in various heating and ventilation systems (HV-systems). It focuses particularly on instrument offsets observed following precipitation events. To quantify pyranometer responses to precipitation, a series of controlled laboratory experiments as well as two targeted field campaigns were performed in 2016. The results indicate that precipitation (as simulated by spray tests or observed under ambient conditions) significantly affects the thermal environment of the instruments and thus their stability. Statistical analyses of laboratory experiments showed that precipitation triggers zero offsets of -4 W m-2 or more, independent of the HV-system. Similar offsets were observed in field experiments under ambient environmental conditions, indicating a clear exceedance of BSRN (Baseline Surface Radiation Network) targets following precipitation events. All pyranometers required substantial time to return to their initial signal states after the simulated precipitation events. Therefore, for BSRN-class measurements, the recommendation would be to flag the radiation measurements during a natural precipitation event and 90 min after it in nighttime conditions. Further daytime experiments show pyranometer offsets of 50 W m-2 or more in comparison to the reference system. As they show a substantially faster recovery, the recommendation would be to flag the radiation measurements within a natural precipitation event and 10 min after it in daytime conditions.

  2. Early Pottery Making in Northern Coastal Peru. Part II: Field Firing Experiments

    Science.gov (United States)

    Shimada, I.; Goldstein, D.; Sosa, J.; Wagner, U.

    2003-09-01

    We present data from three seasons of experimental field work designed to recreate ancient Andean coastal ceramic firing techniques. Based on the recent discovery of two different archaeological ceramic production sites in the La Leche river valley of northern coastal Peru, the opportunity arose to apply Mössbauer spectroscopy and other analytical methods to reconstruct ancient firing procedures. Two sets of firings took place in 1993 and 1997 in Batán Grande using a partially restored Formative kiln from about 800 BC, local hardwood and cow dung as fuel. A third experiment followed in 2000 after the discovery of a Middle Sicán ceramics workshop in use between ca. AD 950 and 1050 at Huaca Sialupe, where an exact replica of an ancient kiln was built from local clay, and fired with local wood and cow dung. Additionally, inverted urns found at Huaca Sialupe were tested for their potential use as furnaces for metal working. Mössbauer spectroscopy was used to compare the physical and chemical state of specimens produced in the field experiments with ancient ceramics and with specimens produced in controlled laboratory experiments.

  3. Constraining chameleon field theories using the GammeV afterglow experiments

    International Nuclear Information System (INIS)

    Upadhye, A.; Steffen, J. H.; Weltman, A.

    2010-01-01

    The GammeV experiment has constrained the couplings of chameleon scalar fields to matter and photons. Here, we present a detailed calculation of the chameleon afterglow rate underlying these constraints. The dependence of GammeV constraints on various assumptions in the calculation is studied. We discuss the GammeV-CHameleon Afterglow SEarch, a second-generation GammeV experiment, which will improve upon GammeV in several major ways. Using our calculation of the chameleon afterglow rate, we forecast model-independent constraints achievable by GammeV-CHameleon Afterglow SEarch. We then apply these constraints to a variety of chameleon models, including quartic chameleons and chameleon dark energy models. The new experiment will be able to probe a large region of parameter space that is beyond the reach of current tests, such as fifth force searches, constraints on the dimming of distant astrophysical objects, and bounds on the variation of the fine structure constant.

  4. Two and Three Parameter Waveform Retracking of Cryosat-2 LRM Waveforms for Gravity Field Determination

    DEFF Research Database (Denmark)

    Jain, Maulik; Andersen, Ole Baltazar; Dall, Jørgen

    2013-01-01

    The project deals with sea surface height and gravity field determination in open ocean using Cryosat-2 LRM data. A three parameter model is being used to find the retracking offset for sea surface height determination. The estimates from the three parameter model are further improved upon by using...... a two parameter model. The sea surface heights thus obtained are used to develop sea surface height anomalies which are further processed to give gravity fields. Retracker performance evaluation is done using sea surface height anomaly and gravity field anomaly....

  5. Engineering and agronomy aspects of a long-term precision agriculture field experiment

    Science.gov (United States)

    Much research has been conducted on specific precision agriculture tools and implementation strategies, but little has been reported on long-term evaluation of integrated precision agriculture field experiments. In 2004 our research team developed and initiated a multi-faceted “precision agriculture...

  6. User experiences with editorial control in online newspaper comment fields

    DEFF Research Database (Denmark)

    Løvlie, Anders Sundnes; Ihlebæk, Karoline Andrea; Larsson, Anders Olof

    2017-01-01

    This article investigates user experiences with editorial control in online newspaper comment fields following the public backlash against online comments after the 2011 terror attacks in Norway. We analyze data from a survey of online news consumers focusing on experiences and attitudes towards...... editorial control set against a spectrum between “interventionist” and “noninterventionist” positions. Results indicate that interventionist respondents rate the quality of online comments as poor, whereas noninterventionist respondents have most often experienced being the target of editorial control...... measures and feel that editorial control has intensified after the terror attacks. We conclude that newspapers should pay attention to the different needs of participants when devising strategies for editorial control. Media professionals should also consider changes to increase the transparency...

  7. Paper 58714 - Exploring activated faults hydromechanical processes from semi-controled field injection experiments

    Science.gov (United States)

    Guglielmi, Y.; Cappa, F.; Nussbaum, C.

    2015-12-01

    The appreciation of the sensitivity of fractures and fault zones to fluid-induced-deformations in the subsurface is a key question in predicting the reservoir/caprock system integrity around fluid manipulations with applications to reservoir leakage and induced seismicity. It is also a question of interest in understanding earthquakes source, and recently the hydraulic behavior of clay faults under a potential reactivation around nuclear underground depository sites. Fault and fractures dynamics studies face two key problems (1) the up-scaling of laboratory determined properties and constitutive laws to the reservoir scale which is not straightforward when considering faults and fractures heterogeneities, (2) the difficulties to control both the induced seismicity and the stimulated zone geometry when a fault is reactivated. Using instruments dedicated to measuring coupled pore pressures and deformations downhole, we conducted field academic experiments to characterize fractures and fault zones hydromechanical properties as a function of their multi-scale architecture, and to monitor their dynamic behavior during the earthquake nucleation process. We show experiments on reservoir or cover rocks analogues in underground research laboratories where experimental conditions can be optimized. Key result of these experiments is to highlight how important the aseismic fault activation is compared to the induced seismicity. We show that about 80% of the fault kinematic moment is aseismic and discuss the complex associated fault friction coefficient variations. We identify that the slip stability and the slip velocity are mainly controlled by the rate of the permeability/porosity increase, and discuss the conditions for slip nucleation leading to seismic instability.

  8. Development of an SPME-GC-MS/MS method for the determination of pesticides in rainwater: Laboratory and field experiments

    International Nuclear Information System (INIS)

    Sauret-Szczepanski, Nathalie; Mirabel, Philippe; Wortham, Henri

    2006-01-01

    A solid-phase microextraction - coupled to a gas chromatography - ion trap tandem mass spectrometry (SPME-GC-MS/MS) method was developed for the quantitative determination in rainwater of 8 pesticides amongst the most used in France and 3 triazines metabolites. The main factors affecting the SPME process were studied. Using a 3 mL sample, the method developed showed good linearity for concentrations ranging from 0.05 to 50 μg L -1 with correlation coefficients between 0.997 and 0.9999 and relative standard deviations (% RSD) below 14%. The study of matrix effects showed that rainwater was too diluted to have any significant influence on the extraction efficiency. To validate the method, a field campaign was carried out on the rain events, which occurred in Strasbourg during a one-year period. The rain concentrations showed patterns of high pesticide concentrations during spring months, which were correlated to the spraying periods of most of these substances. - Solid-phase microextraction efficiency of pesticides in rainwater was optimized

  9. Search for Chameleon Scalar Fields with the Axion Dark Matter Experiment

    International Nuclear Information System (INIS)

    Rybka, G.; Hotz, M.; Rosenberg, L. J; Asztalos, S. J.; Carosi, G.; Hagmann, C.; Kinion, D.; van Bibber, K.; Hoskins, J.; Martin, C.; Sikivie, P.; Tanner, D. B.; Bradley, R.; Clarke, J.

    2010-01-01

    Scalar fields with a 'chameleon' property, in which the effective particle mass is a function of its local environment, are common to many theories beyond the standard model and could be responsible for dark energy. If these fields couple weakly to the photon, they could be detectable through the afterglow effect of photon-chameleon-photon transitions. The ADMX experiment was used in the first chameleon search with a microwave cavity to set a new limit on scalar chameleon-photon coupling β γ excluding values between 2x10 9 and 5x10 14 for effective chameleon masses between 1.9510 and 1.9525 μeV.

  10. Contributions of meaningful experiences gatherings to artistic education field

    Directory of Open Access Journals (Sweden)

    Bernardo Bustamante Cardona

    2012-06-01

    Full Text Available This article shows a theoretical approach to and a description of some contributions of a work of transformation of educational and sociocultural reality carried out by a group of people and institutions, among which are San Buenaventura University, Antioquia Museum, Ediarte Inc. and Antioquia University. Such intervention aims at contributing to the improvement of Artistic Education quality in Antioquia and the nation. In order to understand the significance of these Gatherings, a short historical framework is explained in which global and regional processes of academic activities having an impact on the structure of the Artistic Education field are pointed out. Likewise, some perspectives in the definition of artistic education are tackled and then a definition of Pierre Bourdieu´s concept of fieldis presented. Therefore, Meaningful Experiences Gatherings in Artistic Education (MEGAE are presented and the three first gatherings are described. Finally, it is shown the panorama of the contributions of the gatherings both in the theoretical formulation and relational structure of the field.

  11. Experimental determination of radiated internal wave power without pressure field data

    OpenAIRE

    Lee, Frank M.; Paoletti, M. S.; Swinney, Harry L.; Morrison, P. J.

    2014-01-01

    We present a method to determine, using only velocity field data, the time-averaged energy flux $\\left$ and total radiated power $P$ for two-dimensional internal gravity waves. Both $\\left$ and $P$ are determined from expressions involving only a scalar function, the stream function $\\psi$. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method...

  12. Heat tracer test in an alluvial aquifer: Field experiment and inverse modelling

    Science.gov (United States)

    Klepikova, Maria; Wildemeersch, Samuel; Hermans, Thomas; Jamin, Pierre; Orban, Philippe; Nguyen, Frédéric; Brouyère, Serge; Dassargues, Alain

    2016-09-01

    Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in an injection well and monitoring the evolution of groundwater temperature and tracer concentration in the pumping well and in measurement intervals. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells closely spaced along three transects were used. Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume is explained by the groundwater flow gradient on the site and heterogeneities in the hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with a pilot point approach for inversion of the hydraulic conductivity field, the main preferential flow paths were delineated. The successful application of a field heat tracer test at this site suggests that heat tracer tests is a promising approach to image hydraulic conductivity field. This methodology could be applied in aquifer thermal energy storage (ATES) projects for assessing future efficiency that is strongly linked to the hydraulic conductivity variability in the considered aquifer.

  13. Two-dimensional magnetic field evolution measurements and plasma flow speed estimates from the coaxial thruster experiment

    International Nuclear Information System (INIS)

    Black, D.C.; Mayo, R.M.; Gerwin, R.A.; Schoenberg, K.F.; Scheuer, J.T.; Hoyt, R.P.; Henins, I.

    1994-01-01

    Local, time-dependent magnetic field measurements have been made in the Los Alamos coaxial thruster experiment (CTX) [C. W. Barnes et al., Phys. Fluids B 2, 1871 (1990); J. C. Fernandez et al., Nucl. Fusion 28, 1555 (1988)] using a 24 coil magnetic probe array (eight spatial positions, three axis probes). The CTX is a magnetized, coaxial plasma gun presently being used to investigate the viability of high pulsed power plasma thrusters for advanced electric propulsion. Previous efforts on this device have indicated that high pulsed power plasma guns are attractive candidates for advanced propulsion that employ ideal magnetohydrodynamic (MHD) plasma stream flow through self-formed magnetic nozzles. Indirect evidence of magnetic nozzle formation was obtained from plasma gun performance and measurements of directed axial velocities up to v z ∼10 7 cm/s. The purpose of this work is to make direct measurement of the time evolving magnetic field topology. The intent is to both identify that applied magnetic field distortion by the highly conductive plasma is occurring, and to provide insight into the details of discharge evolution. Data from a magnetic fluctuation probe array have been used to investigate the details of applied magnetic field deformation through the reconstruction of time-dependent flux profiles. Experimentally observed magnetic field line distortion has been compared to that predicted by a simple one-dimensional (1-D) model of the discharge channel. Such a comparison is utilized to estimate the axial plasma velocity in the thruster. Velocities determined in this manner are in approximate agreement with the predicted self-field magnetosonic speed and those measured by a time-of-flight spectrometer

  14. Retrodictive determinism. [covariant and transformational behavior of tensor fields in hydrodynamics and thermodynamics

    Science.gov (United States)

    Kiehn, R. M.

    1976-01-01

    With respect to irreversible, non-homeomorphic maps, contravariant and covariant tensor fields have distinctly natural covariance and transformational behavior. For thermodynamic processes which are non-adiabatic, the fact that the process cannot be represented by a homeomorphic map emphasizes the logical arrow of time, an idea which encompasses a principle of retrodictive determinism for covariant tensor fields.

  15. NSF GK-12 Fellows as Mentors for K-12 Teachers Participating in Field Research Experiences

    Science.gov (United States)

    Ellins, K.; Perry, E.

    2005-12-01

    The University of Texas Institute for Geophysics (UTIG) recognizes the value of providing educational opportunities to K-12 teachers who play a critical role in shaping the minds of young people who are the future of our science. To that end, UTIG established the "Texas Teachers in the Field" program in 2000 to formalize the participation of K-12 teachers in field programs that included UTIG scientists. In 2002, "Texas Teachers in the Field" evolved through UTIG's involvement in a University of Texas at Austin GK-12 project led by the Environmental Sciences Institute, which enabled UTIG to partner a subset of GK-12 Fellows with teachers participating in geophysical field programs. During the three years of the GK-12 project, UTIG successfully partnered four GK-12 Fellows with five K-12 teachers. The Fellows served as mentors to the teachers, as liaisons between UTIG scientists leading field programs and teachers and their students, and as resources in science, mathematics, and technology instruction. Specifically, Fellows prepared teachers and their students for the field investigations, supervised the design of individual Teacher Research Experience (TRE) projects, and helped teachers to develop standards-aligned curriculum resources related to the field program for use in their own classrooms, as well as broader distribution. Although all but one TRE occurred during the school year, Texas school districts and principals were willing to release teachers to participate because the experience and destinations were so extraordinary (i.e., a land-based program in Tierra del Fuego, Argentina; and research cruises to the Southeast Caribbean Sea and Hess Deep in the Pacific Ocean) and carried opportunities to work with scientists from around the world. This exceptional collaboration of GK-12 Fellows, K-12 teachers and research scientists enriches K-12 student learning and promotes greater enthusiasm for science. The level of mentoring, preparation and follow-up provided

  16. Relative work function of clean molybdenum single-crystal planes determined by field emission microscopy

    International Nuclear Information System (INIS)

    Bergeret, G.; Abon, M.; Tardy, B.; Teichner, S.J.

    1974-01-01

    A probe-hole field emission microscope was used to determine the work function of clean molybdenum single crystal planes relative to the average work function of the field emitter, assumed to be 4.20 eV. Results are compared with other available data

  17. Status of neutrino mass experiments

    International Nuclear Information System (INIS)

    Fackler, O.

    1985-12-01

    In 1980 two experiments ignited a fertile field of research the determination of the neutrino masses. Subsequently, over 35 experiments using a variety of techniques have probed or are probing this question. Primarily I will discuss electron antineutrino (hereafter referred to as neutrino) mass experiments. However, let me begin in Section I to discuss astronomical and terrestrial observations which motivated these experiments. In Section II, I will quote limits from muon and tau mass determinations. These limits are more thoroughly discussed in other papers. I will continue by describing the four approaches used to measure the electron neutrino mass. In Section III, tritium beta decay mass determinations will be reviewed. This section includes a general summary of previous experimental results, and discussion of the major ongoing experiments. Section IV offers concluding remarks. 24 refs., 24 figs

  18. Subcriticality determination of low-enriched UO2 lattices in water by exponential experiment

    International Nuclear Information System (INIS)

    Suzaki, Takenori

    1991-01-01

    To determine the static k (effective neutron multiplication factor) ranging from the critical to an extremely subcritical states, the exponential experiments were performed using various sizes of light-water moderated and reflected low-enriched UO 2 lattice cores. For comparison, the pulsed neutron source experiments were also carried out. In the manner of the Gozani's bracketing method applied to the pulsed source experiment, a formula to obtain k from the measured spatial-decay constant was derived on the basis of diffusion theory. Parameters in the formulas needed to obtain k from the respective experiments were evaluated by 4-group neutron diffusion calculations. The results of the exponential experiments agreed well with those of the pulsed source experiments, the 4-group diffusion calculations and the 137-group Monte Carlo calculations. Therefore, the present data-processing method developed for the exponential experiment was demonstrated to be valid. Besides, through the examination on the parameters used in the data processing, it was found that the dependence of parameter value upon k is weak in the exponential experiment compared with that in the pulsed source experiment. This indicates the superiority of the exponential experiment over the pulsed source experiment for the subcriticality determination of a wide range. (author)

  19. Field Experiments on SAR Detection of Film Slicks

    Science.gov (United States)

    Ermakov, S.; da Silva, J. C. B.; Kapustin, I.; Sergievskaya, I.

    2013-03-01

    Field experiments on radar detection of film slicks using satellite synthetic aperture radar TerraSAR-X and X-band scatterometer on board a research vessel are described. The experiments were carried out with surfactant films with known physical parameters, the surface tension and the film elasticity, at low to moderate wind conditions and at different radar incidence angles. It is shown that the depression of radar backscatter (contrast) in films slicks for X-band SAR weakly depends on wind velocity/direction, film elasticity and incidence angles within the range of 200-400. Scatterometer contrasts obtained at incidence angles of about 600 are larger than SAR contrasts. Theoretical analysis of radar contrasts for low-to-moderate incidence angles has been carried out based on a hydrodynamic model of wind wave damping due to films and on a composite radar imaging model. The hydrodynamic model takes into account wave damping due to viscoelastic films, wind wave generation and a phenomenological term describing nonlinear limitation of the wind wave spectrum. The radar model takes into account Bragg scattering and specular scattering mechanisms, the latter is usually negligible compared to the Bragg mechanism at moderate incidence angles (larger than 30-35 degrees), but gives noticeable contribution to radar backscattering at smaller incidence angles particularly for slick areas when cm-scale ripples are strongly depressed by films. Calculated radar contrasts in slicks are compared with experiments and it is concluded that development of the model is needed to predict quantitatively observations.

  20. Ride Your Luck! A Field Experiment on Lottery-Based Incentives for Compliance

    NARCIS (Netherlands)

    M. Fabbri (Marco); P.N. Barbieri (Paolo); M. Bigoni (Maria)

    2016-01-01

    textabstractWe designed a natural-field experiment in the context of local public transportation to test whether rewards in the form of lottery prizes coupled with traditional sanctions efficiently reduce free-riding. We organized a lottery in a medium-size Italian city the participation in which is

  1. Dataset on information strategies for energy conservation: A field experiment in India.

    Science.gov (United States)

    Chen, Victor L; Delmas, Magali A; Locke, Stephen L; Singh, Amarjeet

    2018-02-01

    The data presented in this article are related to the research article entitled: "Information strategies for energy conservation: a field experiment in India" (Chen et al., 2017) [1]. The availability of high-resolution electricity data offers benefits to both utilities and consumers to understand the dynamics of energy consumption for example, between billing periods or times of peak demand. However, few public datasets with high-temporal resolution have been available to researchers on electricity use, especially at the appliance-level. This article describes data collected in a residential field experiment for 19 apartments at an Indian faculty housing complex during the period from August 1, 2013 to May 12, 2014. The dataset includes detailed information about electricity consumption. It also includes information on apartment characteristics and hourly weather variation to enable further studies of energy performance. These data can be used by researchers as training datasets to evaluate electricity usage consumption.

  2. Alkali Rydberg states in electromagnetic fields: computational physics meets experiment

    International Nuclear Information System (INIS)

    Krug, A.

    2001-11-01

    We study highly excited hydrogen and alkali atoms ('Rydberg states') under the influence of a strong microwave field. As the external frequency is comparable to the highly excited electron's classical Kepler frequency, the external field induces a strong coupling of many different quantum mechanical energy levels and finally leads to the ionization of the outer electron. While periodically driven atomic hydrogen can be seen as a paradigm of quantum chaotic motion in an open (decaying) quantum system, the presence of the non-hydrogenic atomic core - which unavoidably has to be treated quantum mechanically - entails some complications. Indeed, laboratory experiments show clear differences in the ionization dynamics of microwave driven hydrogen and non-hydrogenic Rydberg states. In the first part of this thesis, a machinery is developed that allows for numerical experiments on alkali and hydrogen atoms under precisely identical laboratory conditions. Due to the high density of states in the parameter regime typically explored in laboratory experiments, such simulations are only possible with the most advanced parallel computing facilities, in combination with an efficient parallel implementation of the numerical approach. The second part of the thesis is devoted to the results of the numerical experiment. We identify and describe significant differences and surprising similarities in the ionization dynamics of atomic hydrogen as compared to alkali atoms, and give account of the relevant frequency scales that distinguish hydrogenic from non-hydrogenic ionization behavior. Our results necessitate a reinterpretation of the experimental results so far available, and solve the puzzle of a distinct ionization behavior of periodically driven hydrogen and non-hydrogenic Rydberg atoms - an unresolved question for about one decade. Finally, microwave-driven Rydberg states will be considered as prototypes of open, complex quantum systems that exhibit a complicated temporal decay

  3. Determination of key parameters of vector multifractal vector fields

    Science.gov (United States)

    Schertzer, D. J. M.; Tchiguirinskaia, I.

    2017-12-01

    For too long time, multifractal analyses and simulations have been restricted to scalar-valued fields (Schertzer and Tchiguirinskaia, 2017a,b). For instance, the wind velocity multifractality has been mostly analysed in terms of scalar structure functions and with the scalar energy flux. This restriction has had the unfortunate consequences that multifractals were applicable to their full extent in geophysics, whereas it has inspired them. Indeed a key question in geophysics is the complexity of the interactions between various fields or they components. Nevertheless, sophisticated methods have been developed to determine the key parameters of scalar valued fields. In this communication, we first present the vector extensions of the universal multifractal analysis techniques to multifractals whose generator belong to a Levy-Clifford algebra (Schertzer and Tchiguirinskaia, 2015). We point out further extensions noting the increased complexity. For instance, the (scalar) index of multifractality becomes a matrice. Schertzer, D. and Tchiguirinskaia, I. (2015) `Multifractal vector fields and stochastic Clifford algebra', Chaos: An Interdisciplinary Journal of Nonlinear Science, 25(12), p. 123127. doi: 10.1063/1.4937364. Schertzer, D. and Tchiguirinskaia, I. (2017) `An Introduction to Multifractals and Scale Symmetry Groups', in Ghanbarian, B. and Hunt, A. (eds) Fractals: Concepts and Applications in Geosciences. CRC Press, p. (in press). Schertzer, D. and Tchiguirinskaia, I. (2017b) `Pandora Box of Multifractals: Barely Open ?', in Tsonis, A. A. (ed.) 30 Years of Nonlinear Dynamics in Geophysics. Berlin: Springer, p. (in press).

  4. Evidence of lead biomagnification in invertebrate predators from laboratory and field experiments

    International Nuclear Information System (INIS)

    Rubio-Franchini, Isidoro; Rico-Martinez, Roberto

    2011-01-01

    This report includes atomic absorption data from water column, elutriates and zooplankton that demonstrate that lead biomagnifies at El Niagara reservoir, Mexico. Results include field data (bioaccumulation factors) (BAFs) and laboratory data (bioconcentration factors) (BCFs). Two findings: high BAFs for invertebrate predator like Acanthocyclops robustus, Asplanchna brightwellii, Culex sp. larvae, and Hyalella azteca, compared to grazer species Moina micrura and Simocephalus vetulus; low BCF's found for some predators, suggested that lead biomagnifications were taking place. The presence of Moina micrura in the gut of Asplanchna allowed us to design experiments where A. brightwellii was fed lead-exposed M. micrura neonates. The BAF of Asplanchna was 123,684, BCF was 490. Asplanchna individuals fed exposed Moina had 13.31 times more lead than Asplanchna individuals just exposed 48-h to lead, confirming that lead biomagnification occurs. Results of two fish species showed no lead biomagnification, suggesting that lead biomagnification might be restricted to invertebrate predators. - Highlights: → Study shows lead biomagnification evidence in reservoirs where top predators are invertebrates. → Study discusses why in previous studies lead biomagnifications were not detected. → Evidence of biomagnification comes from field and laboratory studies. - This study shows evidence (from field and laboratory experiments) of lead biomagnification in a freshwater reservoir where the main predators are invertebrates.

  5. Determination of the maximum-depth to potential field sources by a maximum structural index method

    Science.gov (United States)

    Fedi, M.; Florio, G.

    2013-01-01

    A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

  6. Determination of the elementary charge and the quantum metrological triangle experiment

    Energy Technology Data Exchange (ETDEWEB)

    Feltin, N.; Piquemal, F. [Laboratoire National de Metrologie et d' Essais (LNE), 78 - Trappes (France)

    2009-06-15

    The elementary charge e is of fundamental importance in physics. The determination of its value, which is closely linked to progress of the measurement techniques, started in the beginning of the twentieth century and is still on-going. Today, in the frame of the CODATA adjustment, the evaluation of the fundamental constant, e, is derived from a complex calculation and is no more related to a single experiment. But the development of single electron tunneling (SET) devices, started in the early nineties, has opened the path towards modern metrological systems as quantum current sources. Thus a new direct determination of e is possible by implementing an electron pump and the set-up of the quantum metrological triangle (QMT) in combination with the experiments linking mechanical and electrical units. Furthermore, we show how the QMT experiment can contribute to the establishment of a new system of units based on fundamental constants of physics. (authors)

  7. Insights into organic carbon oxidation potential during fluvial transport from laboratory and field experiments

    Science.gov (United States)

    Scheingross, J. S.; Dellinger, M.; Eglinton, T. I.; Fuchs, M. C.; Golombek, N.; Hilton, R. G.; Hovius, N.; Lupker, M.; Repasch, M. N.; Sachse, D.; Turowski, J. M.; Vieth-Hillebrand, A.; Wittmann, H.

    2017-12-01

    Over geologic timescales, the exchange of organic carbon (OC) between the atmosphere, hydropshere, biosphere and geosphere can be a major control on atmospheric carbon dioxide concentrations. The carbon fluxes from the oxidation of rock-derived OC (a CO2 source) and erosion, transport, and burial of biospheric OC (a potential CO2 sink) during fluvial transit are approximately the same order of magnitude or larger than those from silicate weathering. Despite field data showing increasing oxidation of OC moving downstream in lowland rivers, it is unclear if losses occur primarily during active fluvial transport, where OC is in continual motion within an aerated river, or during periods of temporary storage in river floodplains which may be anoxic. The unknown location of OC oxidation (i.e., river vs. floodplain) limits our ability to mechanistically link geochemical and geomorphic processes which are required to develop models capable of predicting OC losses, constrain carbon budgets, and unravel links between climate, tectonics, and erosion. To fill this knowledge gap, we investigated OC oxidation in controlled laboratory experiments and a simplified field setting. We performed experiments in annular flumes that simulate fluvial transport without floodplain storage, allowing mixtures of OC-rich and siliciclastic sediment to be transported for distances of 1000 km. Preliminary experiments exploring both rock-derived and biospheric OC sources show minimal OC oxidation during active river transport, consistent with the idea that the majority of OC loss occurs during transient floodplain storage. These results are also consistent with new field data collected in the Rio Bermejo, Argentina, a lowland river traversing 800 km with no tributary inputs, where aged floodplain deposits have 3 to 10 times lower OC concentrations compared to modern river sediments. Together our field data and experiments support the hypothesis that oxidation of OC occurs primarily during

  8. Tuning the Mass of Chameleon Fields in Casimir Force Experiments

    CERN Document Server

    Brax, Ph; Davis, A C; Shaw, D J; Iannuzzi, D

    2010-01-01

    We have calculated the chameleon pressure between two parallel plates in the presence of an intervening medium that affects the mass of the chameleon field. As intuitively expected, the gas in the gap weakens the chameleon interaction mechanism with a screening effect that increases with the plate separation and with the density of the intervening medium. This phenomenon might open up new directions in the search of chameleon particles with future long range Casimir force experiments.

  9. Hydraulic conductivity determination of a dark red latosol by gamma attenuation and tensiometry

    International Nuclear Information System (INIS)

    Oliveira, Julio Cesar Martins de; Reichardt, Klaus; Costa, Antonio Carlos Saraiva da

    1995-01-01

    Results for the hydraulic conductivity of a dark red latosol (Oxisol) under laboratory and field conditions are presented. The laboratory experiments simulated field conditions through the measurement of the soil water content profiles as a function of time in soil columns. The data were obtained by the 241 Am gamma-ray transmission method, using standard gamma ray spectrometry equipment. Tensiometers at the depths of 10 and 25 cm were used to obtain the soil water content profiles as a function of time in the field experiments. The hydraulic conductivity functions were determined through internal soil drainage. The results showed higher values of the hydraulic conductivity measured in the field, compared with the laboratory values. The hydraulic conductivity determination methods presented distinct values for the field experiments as well as for the laboratory ones. (author)

  10. Innovating the Experience of Peer Learning and Earth Science Education in the Field

    Science.gov (United States)

    Scoates, J. S.; Hanano, D. W.; Weis, D.; Bilenker, L.; Sherman, S. B.; Gilley, B.

    2017-12-01

    The use of active learning and collaborative strategies is widely gaining momentum at the university level and is ideally suited to field instructional settings. Peer learning, when students learn with and from each other, is based on the principle that students learn in a more profound way by explaining their ideas to others and by participating in activities in which they can learn from their peers. The Multidisciplinary Applied Geochemistry Network (MAGNET), an NSERC Collaborative Research and Training Experience (CREATE) initiative in Canada, recently experimented with this approach during its fourth annual workshop in August 2016. With a group of 25 geochemistry graduate students from universities across Canada, three remarkable field sites in Montana and Wyoming were explored: the Stillwater Complex, the Beartooth Mountains, and Yellowstone National Park. Rather than developing a rigorous teaching curriculum led by faculty, groups of students were tasked with designing and delivering half-day teaching modules that included field activities at each of the locations. Over the course of two months and with feedback from mentors, the graduate students transformed their ideas into formal lesson plans, complete with learning goals, a schedule of teaching activities, equipment lists, and plans for safety and environmental mitigation. This shift, from teacher-centered to learner-centered education, requires students to take greater initiative and responsibility for their own learning and development. We highlight the goals, structure and implementation of the workshop, as well as some of the successes and challenges. We also present the results of participant feedback taken immediately after each lesson and both pre- and post-trip surveys. The outdoor classroom and hands-on activities accelerated learning of field techniques and enhanced understanding of complex geological systems and processes. The trainee-led format facilitated peer knowledge transfer and the

  11. Data management for interdisciplinary field experiments: OTTER project support

    Science.gov (United States)

    Angelici, Gary; Popovici, Lidia; Skiles, J. W.

    1993-01-01

    The ability of investigators of an interdisciplinary science project to properly manage the data that are collected during the experiment is critical to the effective conduct of science. When the project becomes large, possibly including several scenes of large-format remotely sensed imagery shared by many investigators requiring several services, the data management effort can involve extensive staff and computerized data inventories. The OTTER (Oregon Transect Ecosystem Research) project was supported by the PLDS (Pilot Land Data System) with several data management services, such as data inventory, certification, and publication. After a brief description of these services, experiences in providing them are compared with earlier data management efforts and some conclusions regarding data management in support of interdisciplinary science are discussed. In addition to providing these services, a major goal of this data management capability was to adopt characteristics of a pro-active attitude, such as flexibility and responsiveness, believed to be crucial for the effective conduct of active, interdisciplinary science. These are also itemized and compared with previous data management support activities. Identifying and improving these services and characteristics can lead to the design and implementation of optimal data management support capabilities, which can result in higher quality science and data products from future interdisciplinary field experiments.

  12. Fine-grained sediment deposition on mussel beds in the Oosterschelde (The Netherlands), determined from echosoundings, radio-isotopes and biodeposition field experiments

    International Nuclear Information System (INIS)

    Brinke, W.B.M. ten; Augustinus, P.G.E.F.

    1995-01-01

    Sedimentation rates of 5-20 cm year -1 were calculated from 137 Cs + 134 Cs activity profiles and echosoundings in a mussel cultivation area in the western part of the Oosterschelde. Sedimentation rates based on 210 Pb activity profiles are far too low, mainly due to the deposition of 'aged' sediment, i.e. sediment eroded elsewhere inside the basin and not fully enriched with 210 Pb at the moment of deposition. Also, specific adsorption to the finest sediment components, mixing, winnowing, and mobilization of the caesium have affected the lead and caesium profiles. Field experiments on mussel plots showed that mussels deposit 5-10 cm of fine-grained sediment during the summer. This biodeposition about equals the settling from flocculation in the water column. Micro-fabric microscope studies revealed that pellets do not dominate the sediments, indicating that some of the pellets are broken down or resuspended. (author)

  13. Short-term, informal, and low-stakes scientific laboratory and field experiences improve STEM student retention and academic success

    Science.gov (United States)

    Hintz, C.; Pride, C. J.; Cox, T.

    2017-12-01

    Formal internship experiences strongly improve student success in the STEM fields. Classical programs like NSF's Research Experiences for Undergraduates are highly successful for traditional and non-traditional students. Moreover when early undergraduate and at-risk (e.g., low income, academically-challenged) students engage in these experiences, their career paths are re-enforced or changed, academic progress and retention improves, and they are encouraged to continue into graduate school. Students build connections to their course-based learning and experience the life of a working scientist. However, NSF formal experiences are relatively expensive to provide (>5000 per student per experience) and are available to fewer than 5% of geoscience majors each year. Although other funded formal internship opportunities exist, they are likely available to no more than 10% of total enrolled geoscience students. These high-quality programs cannot impact enough early undergraduate students to encourage their remaining in science and improve the current overall retention and graduation rates in the US. Savannah State University faculty successfully completed multiple grants funding low-stakes undergraduate field-science experiences. These short-term (semester to year), part-time (5-10h/week) experiences provide similar classroom-to-real-world science connections, offer students direct laboratory and field experiences, build skill sets, and provide a small source of revenue assisting financially-challenged students to stay on campus rather than seeking off-campus employment. For a much lower investment in time and grant resources (500-1500 per student per experience), participant graduation rates exceeded 80%, well above the university 27-34% graduation rate during the same time period. Relatively small infusions of research dollars targeting undergraduate experiences in the field and laboratory could significantly impact long-term student outcomes in STEM disciplines. These

  14. Is there any consistency between the microplastics found in the field and those used in laboratory experiments?

    Science.gov (United States)

    Phuong, Nam Ngoc; Zalouk-Vergnoux, Aurore; Poirier, Laurence; Kamari, Abderrahmane; Châtel, Amélie; Mouneyrac, Catherine; Lagarde, Fabienne

    2016-04-01

    The ubiquitous presence and persistency of microplastics (MPs) in aquatic environments are of particular concern since they represent an increasing threat to marine organisms and ecosystems. Great differences of concentrations and/or quantities in field samples have been observed depending on geographical location around the world. The main types reported have been polyethylene, polypropylene, and polystyrene. The presence of MPs in marine wildlife has been shown in many studies focusing on ingestion and accumulation in different tissues, whereas studies of the biological effects of MPs in the field are scarce. If the nature and abundance/concentrations of MPs have not been systematically determined in field samples, this is due to the fact that the identification of MPs from environmental samples requires mastery and execution of several steps and techniques. For this reason and due to differences in sampling techniques and sample preparation, it remains difficult to compare the published studies. Most laboratory experiments have been performed with MP concentrations of a higher order of magnitude than those found in the field. Consequently, the ingestion and associated effects observed in exposed organisms have corresponded to great contaminant stress, which does not mimic the natural environment. Medium contaminations are produced with only one type of polymer of a precise sizes and homogenous shape whereas the MPs present in the field are known to be a mix of many types, sizes and shapes of plastic. Moreover, MPs originating in marine environments can be colonized by organisms and constitute the sorption support for many organic compounds present in environment that are not easily reproducible in laboratory. Determination of the mechanical and chemical effects of MPs on organisms is still a challenging area of research. Among the potential chemical effects it is necessary to differentiate those related to polymer properties from those due to the sorption

  15. Brine Migration in Heated Salt: Lessons Learned from Field Experiments

    Science.gov (United States)

    Kuhlman, K. L.; Matteo, E. N.; Mills, M.

    2017-12-01

    We summarize several interesting brine migration related phenomena hinted at in field experiments from field testing related to salt radioactive waste repositories in Germany and the US. Past heater tests in salt have shown 1) thermal-hydrological-mechanical coupling is quite strong during both heating and cooling; 2) chemical composition of brine evolves during heating, and comprises a mix of several water sources; and 3) acid gas (HCl) generation has been observed during past heater tests and may have multiple mechanisms for formation. We present a heated brine migration test design, formulated with these complexities in mind. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

  16. Field experiments on seed dispersal by wind in ten umbelliferous species (Apiaceae)

    NARCIS (Netherlands)

    Jongejans, E.; Telenius, A.

    2001-01-01

    This report presents data from experiments on seed dispersal by wind for ten species of the family Apiaceae. Seed shadows were obtained in the field under natural conditions, using wind speeds between four and ten m/s. The flight of individual seeds was followed by eye, and seed shadows were

  17. Dewey's Concept of Experience for Inquiry-Based Landscape Drawing during Field Studies

    Science.gov (United States)

    Tillmann, Alexander; Albrecht, Volker; Wunderlich, Jürgen

    2017-01-01

    The epistemological and educational philosophy of John Dewey is used as a theoretical basis to analyze processes of knowledge construction during geographical field studies. The experience of landscape drawing as a method of inquiry and a starting point for research-based learning is empirically evaluated. The basic drawing skills are acquired…

  18. Comparison of laboratory and field experience of PWSCC in Alloy 182 weld metal

    Energy Technology Data Exchange (ETDEWEB)

    Scott, P.; Meunier, M.-C.; Steltzlen, F. [AREVA NP, Tour AREVA, Paris La Defense (France); Calonne, O.; Foucault, M. [AREVA NP, Centre Technique, Le Creusot Cedex (France); Combrade, P. [ACXCOR, Saint Etienne (France); Amzallag, C. [EDF, SEPTEN, Villeurbanne (France)

    2007-07-01

    Laboratory studies of stress corrosion cracking of the nickel base weld metal, Alloy 182, in simulated PWR primary water suggest similar resistance to crack initiation and somewhat enhanced propagation rates relative to wrought Alloy 600. By contrast, field experience of cracking in the primary circuits of PWRs shows in general much better performance for Alloy 182 relative to Alloy 600 than would be anticipated from laboratory studies. This paper endeavours to resolve this apparent conundrum. It draws on the conclusions of recent research that has focussed on the role of surface finish, particularly cold work and residual stresses resulting from different fabrication processes, on the risk of initiating IGSCC in nickel base alloys in PWR primary water. It also draws on field experience of stress corrosion cracking that highlights the important role of surface finish for crack initiation. (author)

  19. Translation of field-reversed configurations in the FRX C/T experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.; Klingner, P.L.; Linford, R.K.; McKenna, K.F.; Milroy, R.D.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

    1984-01-01

    One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device.

  20. Translation of field-reversed configurations in the FRX C/T experiment

    International Nuclear Information System (INIS)

    Rej, D.J.; Armstrong, W.T.; Chrien, R.E.

    1984-01-01

    One of the unique features inherent to compact toroids is the potential ability to translate the plasma along its geometric axis. CT translation has proven useful in reactor design studies, and has been the focus of several experimental investigations. In this paper, we report on the initial results from translation experiments performed with the field-reversed configuration (FRC) plasmas generated in the FRX-C/T device

  1. Enhancing the Understanding of Marine Ecosystems through Teleducation and Field Experiences

    Science.gov (United States)

    Macko, S.

    2006-12-01

    This project is an outreach and education program with a partner in the K-12 schools at Accomack County on the Eastern Shore of Virginia. It endeavors to build a community more knowledgeable of the importance the ocean plays daily in our lives, and our own impact on the ocean. It is an program built in stages that: 1) Establish high speed teleducation linkages with Eastern Shore of Virginia High Schools, for live interactive, classes (teleducation) for earth science teachers enabling them to remotely participate in University of Virginia classes in Oceanography (designed on a faculty development basis or acquire NSTA certification in Earth Science Education, as well as participation by seniors in the Accomack Schools; 2) Establish field experiences for teachers and selected students that involve travel to both the Virginia Coast Reserve Long Term Ecological Research (VCR/LTER) Center, UVA and the NOAA Beaufort, NC Laboratory to observe first- hand the science programs at those locations and participate in cutting edge coastal marine research efforts. These experiences will not only improve student understanding of the ocean-atmosphere biogeophysical system, but also encourage students to explore the sciences as a field of study and possible vocation. Advanced high school students and science teachers from Accomack County Public Schools participated in an experience involving field and laboratory methods employed in a NSF-sponsored study of the coupled natural-human dynamics on the Eastern Shore of Virginia over the past 500 years (NSF-Biocomplexity). Students and teachers worked with researchers of the VCR facility in Oyster, VA, collected sediment cores from Chesapeake Bay tributaries, and traveled to the Organic Geochemistry Laboratory at UVA, in Charlottesville, VA to prepare and analyze samples for isotopic and palynological information. In a first of its kind connectivity, in June/July, 2006, using high speed internet connections, a summer class in

  2. Subsurface oil release field experiment - observations and modelling of subsurface plume behaviour

    International Nuclear Information System (INIS)

    Rye, H.; Brandvik, P.J.; Reed, M.

    1996-01-01

    An experiment was conducted at sea, in which oil was released from 107 metres depth, in order to study plume behaviour. The objective of the underwater release was to simulate a pipeline leakage without gas and high pressure and to study the behaviour of the rising plume. A numerical model for the underwater plume behaviour was used for comparison with field data. The expected path of the plume, the time expected for the plume to reach the sea surface and the width of the plume was modelled. Field data and the numerical model were in good agreement. 10 refs., 2 tabs., 9 figs

  3. Enviromental behavior of sulfentrazone and fipronil in a Brazilian clayey latosol: field experiment and simulation

    Directory of Open Access Journals (Sweden)

    Rômulo Penna Scorza Júnior

    2014-10-01

    Full Text Available There has been an urgent need to assess pesticide environmental behavior under Brazilian field conditions and to evaluate the risks associated to its use in agriculture. Besides a qualitative and quantitative interpretation of field experiments to acquire understanding about pesticide environmental behaviour, field experiments are important to test pesticide fate models. Environmental behaviour of fipronil and sulfentrazone in a sugarcane area in Dourados, MS, was evaluated until 257 days after application. Moreover, the PEARL model was tested to simulate the fate of these two pesticides in the field. Soil samples for pesticide residue quantification and water content were taken at 0-10, 10-30, 30-50, 50-70 and 70-100 cm depth. There was a fast dissipation of both pesticides at soil surface within 15 days after application and their leaching was not beyond 30 cm depth. Dissipation and leaching satisfactory simulations for both pesticides were achieved only after calibration of half-life values or using a reduced initial dose. This study shows that fast dissipation of pesticides in the field can be an important process to consider when assessing the environmental behavior of pesticides in Brazil.

  4. Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

    2009-11-30

    Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

  5. Broadband measurements of high-frequency electric field levels and exposure ratios determination

    Directory of Open Access Journals (Sweden)

    Vulević Branislav

    2017-01-01

    Full Text Available The exposure of people to high-frequency electromagnetic fields (over 100 kHz that emanate from modern wireless information transmission systems is inevitable in modern times. Due to the rapid development of new technologies, measuring devices and their connection to measuring systems, the first fifteen years of the 21st century are characterized by the appearance of different approaches to measurements. This prompts the need for the assessment of the exposure of people to these fields. The main purpose of this paper is to show how to determine the exposure ratios based on the results of broadband measurements of the high-frequency electric field in the range of 3 MHz to 18 GHz in the environment.

  6. Development of Virtual Field Experiences for undergraduate geoscience using 3D models from aerial drone imagery and other data

    Science.gov (United States)

    Karchewski, B.; Dolphin, G.; Dutchak, A.; Cooper, J.

    2017-12-01

    In geoscience one must develop important skills related to data collection, analysis and interpretation in the field. The quadrupling of student enrollment in geoscience at the University of Calgary in recent years presents a unique challenge in providing field experience. With introductory classes ranging from 300-500 students, field trips are logistical impossibilities and the impact on the quality of student learning and engagement is major and negative. Field experience is fundamental to geoscience education, but is presently lacking prior to the third year curriculum. To mitigate the absence of field experience in the introductory curricula, we are developing a set of Virtual Field Experiences (VFEs) that approximate field experiences via inquiry-based exploration of geoscientific principles. We incorporate a variety of data into the VFEs including gigapan photographs, geologic maps and high resolution 3D models constructed from aerial drone imagery. We link the data using a web-based platform to support lab exercises guided by a set of inquiry questions. An important feature that distinguishes a VFE is that students explore the data in a nonlinear fashion to construct and revise models that explain the nature of the field site. The aim is to approximate an actual field experience rather than provide a virtual guided tour where the explanation of the site comes pre-packaged. Thus far, our group has collected data at three sites in Southern Alberta: Mt. Yamnuska, Drumheller environs and the North Saskatchewan River valley near the toe of the Saskatchewan Glacier. The Mt. Yamnuska site focusses on a prominent thrust fault in the front ranges of the Western Cordillera. The Drumheller environs site demonstrates the siliciclastic sedimentation and stratigraphy typical of southeastern Alberta. The Saskatchewan Glacier site highlights periglacial geomorphology and glacial recession. All three sites were selected because they showcase a broad range of geoscientific

  7. Illness Experience, Self-Determination, and Recreational Activities in Pediatric Asthma.

    Science.gov (United States)

    Bingham, Peter M; Crane, Ian; Manning, Sarah Waterman

    2017-06-01

    Although asthma self-management depends on ongoing and accurate self-assessment by the patient, pediatric asthma patients have weak skills in the area of symptom perception. Before developing an asthma game targeted to improving asthma self-management and improved symptom awareness, we sought to identify gaps in existing games. To clarify the role of relatedness and autonomy in asthma health game design, we investigated symptom awareness, vocabulary, and self-determination through a series of semi-structured interviews with children suffering from asthma. Using self-determination theory as a framework, interviews were oriented to patients' illness experience and vocabulary related to symptomatology, as well as to recreational activities. Formative analysis of the interviews reveals attitudes, perceptions, and motivational factors arising in the context of childhood asthma, and it elucidates the images and vocabulary associated with both illness experience and recreational activities. Qualitative assessment of patient perspectives leads to specific recommendations for game design ideas that will support market entry of a spirometer-controlled game for children with asthma.

  8. High Performance Clocks and Gravity Field Determination

    Science.gov (United States)

    Müller, J.; Dirkx, D.; Kopeikin, S. M.; Lion, G.; Panet, I.; Petit, G.; Visser, P. N. A. M.

    2018-02-01

    Time measured by an ideal clock crucially depends on the gravitational potential and velocity of the clock according to general relativity. Technological advances in manufacturing high-precision atomic clocks have rapidly improved their accuracy and stability over the last decade that approached the level of 10^{-18}. This notable achievement along with the direct sensitivity of clocks to the strength of the gravitational field make them practically important for various geodetic applications that are addressed in the present paper. Based on a fully relativistic description of the background gravitational physics, we discuss the impact of those highly-precise clocks on the realization of reference frames and time scales used in geodesy. We discuss the current definitions of basic geodetic concepts and come to the conclusion that the advances in clocks and other metrological technologies will soon require the re-definition of time scales or, at least, clarification to ensure their continuity and consistent use in practice. The relative frequency shift between two clocks is directly related to the difference in the values of the gravity potential at the points of clock's localization. According to general relativity the relative accuracy of clocks in 10^{-18} is equivalent to measuring the gravitational red shift effect between two clocks with the height difference amounting to 1 cm. This makes the clocks an indispensable tool in high-precision geodesy in addition to laser ranging and space geodetic techniques. We show how clock measurements can provide geopotential numbers for the realization of gravity-field-related height systems and can resolve discrepancies in classically-determined height systems as well as between national height systems. Another application of clocks is the direct use of observed potential differences for the improved recovery of regional gravity field solutions. Finally, clock measurements for space-borne gravimetry are analyzed along with

  9. Review of WAG Field Experience

    DEFF Research Database (Denmark)

    Christensen, Jes Reimer; Stenby, Erling Halfdan; Skauge, A.

    2001-01-01

    well spacing is in the order of 1000 m. For the fields reviewed, a common trend for the successful injections is an increased oil recovery in the range of 5 to 10% of the oil initially in place (OIIP). Very few field trials have been reported as unsuccessful, but operational problems are often noted...

  10. New method for the exact determination of the effective conductivity and the local field in RLC networks

    International Nuclear Information System (INIS)

    Zekri, L.; Zekri, N.; Bouamrane, R.

    1999-10-01

    We present a new numerical method for determining exactly the effective conductivity and the local field for random RLC networks. This method is compared to a real space renormalization group method and the Frank and Lobb method. Although our method is slower than the Frank and Lobb method, it also computes exactly the local field for large size systems. We also show that the renormalization group method fails in determining the local field. (author)

  11. Spectroscopic determination of the magnetic field distribution in a gas-puff Z-pinch plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gregorian, L; Davara, G; Kroupp, E; Maron, Y [Weizmann Institute of Science, Rehovot (Israel). Dept. of Particle Physics

    1997-12-31

    The time dependent radial distribution of the magnetic field in a gas-puff Z-pinch plasma has been determined by observing the Zeeman effect on emission lines, allowed for by polarization spectroscopy and high accuracy line-profile measurements. A modeling scheme, based on a 1-D magnetic diffusion equation, is used to fit the experimental data. The plasma conductivity inferred from the field distribution was found to be consistent with the Spitzer conductivity. The current density distribution and the time dependent plasma region in which the entire circuit current flows were determined. (author). 3 figs., 6 refs.

  12. Investigation of material properties by NMR in low and high magnetic fields

    International Nuclear Information System (INIS)

    Rata, D.G.

    2006-01-01

    In this work the experiments have been performed at both low and high field. The experiments cover various domains from simple relaxation experiments in low field to diffusion and spin-diffusion in high field. The applications of low-field investigations are: - quality control of chemical products. - water content determination inside of the walls of buildings. - determination of multilayer polymer coatings on a concrete. In high-field NMR several alkane molecules swollen at equilibrium in cross-linked natural rubber samples have been investigated and analyzed based on the assumptions of the Vrentras theory. A small diffusion anisotropy of the order of 10% has been discovered because of a deformation of free volume under compression. The anisotropy increases with the cross-link density and the compression ratio. The results presented in this study show that the solvent size influences the anisotropy of the diffusion process through the size parameter. The spin-diffusion measurements have been performed on Stanyl samples with different aged samples, at controlled temperature conditions. (orig.)

  13. Investigation of material properties by NMR in low and high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Rata, D.G.

    2006-07-10

    In this work the experiments have been performed at both low and high field. The experiments cover various domains from simple relaxation experiments in low field to diffusion and spin-diffusion in high field. The applications of low-field investigations are: - quality control of chemical products. - water content determination inside of the walls of buildings. - determination of multilayer polymer coatings on a concrete. In high-field NMR several alkane molecules swollen at equilibrium in cross-linked natural rubber samples have been investigated and analyzed based on the assumptions of the Vrentras theory. A small diffusion anisotropy of the order of 10% has been discovered because of a deformation of free volume under compression. The anisotropy increases with the cross-link density and the compression ratio. The results presented in this study show that the solvent size influences the anisotropy of the diffusion process through the size parameter. The spin-diffusion measurements have been performed on Stanyl samples with different aged samples, at controlled temperature conditions. (orig.)

  14. 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

  15. Self-Determination and Goal Orientation in Track and Field

    Science.gov (United States)

    Chin, Ngien-Siong; Khoo, Selina; Low, Wah-Yun

    2012-01-01

    This study investigated gender, age group and locality differences in adolescent athletes’ self-determination motivation and goal orientations in track and field. It also examined the relationship between the self-determination theory and achievement goal theory. A total of 632 (349 boys, 283 girls) adolescent athletes (aged 13–18 years) completed the Sports Motivation Scale and Task and Ego Orientation in Sport Questionnaire. Results indicated significant differences between gender on intrinsic motivation, extrinsic motivation, amotivation (t(630) = 4.10, p motivation, extrinsic motivation, amotivation and ego orientation. A significant difference was found between age groups on task orientation (t(630) = 1.94, p motivation. Task orientation was related to intrinsic motivation (r = 0.55, p extrinsic motivation (r = 0.55, p motivation (r = 0.30, p extrinsic motivation (r = 0.36, p motivation, extrinsic motivation and amotivation accounted for 30.5% of the variances in task orientation. PMID:23486244

  16. French developments and experience in the field of inservice inspection

    International Nuclear Information System (INIS)

    Saglio, Robert; Destribats, M.-T.; Pigeon, Michel; Roule, Maurice; Touffait, A.-M.

    1979-01-01

    The French PWR nuclear plant program was at the origin of a large amount of R and D work in the field of inservice inspection. The actions which were undertaken may be split up into different levels: - the regulatory level, the R and D level, the design level, the flaw evaluation level. The first results of pre and inservice inspections are presented. The experience gained by French Atomic Energy Commission with new techniques like focussed ultrasonics transducers and multi frequencies Eddy current apparatus are discussed

  17. Increasing public debt collection with nudging: Results of two natural field experiments

    DEFF Research Database (Denmark)

    Jensen, Niels Holm; Nielsen, Lisbeth Fyhn; Rasmussen, Stephan

    2017-01-01

    Using two natural field experiments, we tested whether nudging could contribute as a cost-free instrument to increase voluntary public debt collection. We manipulated standard reminder notices sent to two samples (N = 396 and N = 549) with public debt in a municipality in Denmark, a country...... that nudging may contribute to public debt collection....

  18. The effects of payment instruments on charitable giving: Evidence from a field experiment

    NARCIS (Netherlands)

    Soetevent, A.R.

    2008-01-01

    This study reports on a door-to-door field experiment on the effects of introducing portable debit terminals for mobile payment authorization on the contributions to charity. About 4,500 households are approached, randomly divided in three experimental treatments, distinguished by the possibility

  19. Effects of supervision on tax compliance: Evidence from a field experiment in Austria

    Science.gov (United States)

    Gangl, Katharina; Torgler, Benno; Kirchler, Erich; Hofmann, Eva

    2014-01-01

    We conduct a field experiment on tax compliance, focusing on newly founded firms. As a novelty the effect of tax authorities’ supervision on timely tax payments is examined. Interestingly, results show no positive overall effect of close supervision on tax compliance. PMID:25843992

  20. Electrochemical methods for the inspection of reinforcement corrosion in concrete structures - field experience

    International Nuclear Information System (INIS)

    Elsener, B.; Boehni, H.

    1992-01-01

    Maintenance and planning of the restoration work on reinforced concrete structures need a rapid, non-destructive inspection technique that detects corrosion at an early stage. In this paper the field experience with electrochemical techniques are reported. The results of potential surveys on bridge decks of the Swiss highways, realized with a new computer controlled eight-wheel measurement system, clearly show that a fixed potential value (as proposed in ASTM C 876-87) for the identification and location of active corrosion of steel in concrete does not exist. A statistical elaboration of the potential data allows to identify the potential value for corroding and passive rebar for each structure individually. A rapid new technique using galvanostatic pulse measurements was tested successfully on site. It gives clear, unambiguous results on the corrosion state of the rebars when half-cell potentials are uncertain. In addition, the ohmic resistance and the apparent polarization resistance are determined from the evaluation of the transients. From these values the concrete resistivity and the actual corrosion rate of the rebars may be estimated

  1. Account of magnetic field effects of polarized proton target on charged particle trajectories in experiments with magnetic spectrometers

    International Nuclear Information System (INIS)

    Telegin, Yu.N.; Ranyuk, Yu.N.; Karnaukhov, I.M.; Lukhanin, A.A.; Sporov, E.A.

    1980-01-01

    Some effects of the influence of magnetic field of a polarized proton target (PPT) on trajectories of secondary particles in experiments using magnetic spectrometers are considered. It is shown that these effects can be eliminated by the target shift relatively to the spectrometer rotation axis and variation of the spectrometer installation angle. Numerical calculations of the correction values were performed for emitted particle momenta of 100-800 MeB/s and working intensity of the H 0 magnetic field H 0 =27 kG. The influence of the PPT magnetic field on the functions of angular and energy resolution in the γp→π + n experiment is investigated. The results obtained can be used in experiments with a polarized proton target

  2. Overview of BELGATOM's industrial experience in the field of radwaste bituminization, cementation and radwaste package storage

    International Nuclear Information System (INIS)

    Glibert, R.; Debieve, P.; Averbeke, J. van; Centner, B.

    1993-01-01

    Radioactive waste processing experience in Belgium is introduced. BELGATOM partners in Belgium have accumulated experience for over 25 years in the field of rad waste treatment and conditioning by bituminization and cementation and in the storage of the resulting rad waste packages

  3. Compatibility of the Chameleon-Field Model with Fifth-Force Experiments, Cosmology, and PVLAS and CAST Results

    International Nuclear Information System (INIS)

    Brax, Philippe; Bruck, Carsten van de; Davis, Anne-Christine

    2007-01-01

    We analyze the PVLAS results using a chameleon field whose properties depend on the environment. We find that, assuming a runaway bare potential V(φ) and a universal coupling to matter, the chameleon potential is such that the scalar field can act as dark energy. Moreover, the chameleon-field model is compatible with the CERN Axion Solar Telescope results, fifth-force experiments, and cosmology

  4. Experiences of ZAMG on mixing height determination

    Energy Technology Data Exchange (ETDEWEB)

    Piringer, M. [Zentralanstalt fuer Meteorologie und Geodynamik, ZAMG, Vienna (Austria)

    1997-10-01

    Temperature inversions in the boundary layer occur quite often, esp. in mountainous terrain by which Austria is covered to a large extent, and can lead to enhanced pollution at the surface because the air volume available for dilution is then vertically limited. The Department of Environmental Meteorology of ZAMG therefore set up several field programs in the past to study such conditions at a variety of sites in Austria, using tethersondes and Sodars. Early investigations aimed at comparing Sodar echo profiles to the tethersonde temperature profiles to derive mixing heights from the Sodar echo structure. More recently, evolving from KONGEX, the `convective boundary layer experiment`, mixing heights calculated for Vienna by the OML model were compared to those derived from radiosonde and tethersonde potential temperature profiles. Results of these investigations will be presented, focussing on the problems when using the different methods. New efforts to derive mixing heights from data were also undertaken and are discussed separately. (au)

  5. Interactions between Radial Electric Field, Transport and Structure in Helical Plasmas

    International Nuclear Information System (INIS)

    Ida, Katsumi and others

    2006-01-01

    Control of the radial electric field is considered to be important in helical plasmas, because the radial electric field and its shear are expected to reduce neoclassical and anomalous transport, respectively. Particle and heat transport, that determines the radial structure of density and electron profiles, sensitive to the structure of radial electric field. On the other hand, the radial electric field itself is determined by the plasma parameters. In general, the sign of the radial electric field is determined by the plasma collisionality, while the magnitude of the radial electric field is determined by the temperature and/or density gradients. Therefore the structure of radial electric field and temperature and density are strongly coupled through the particle and heat transport and formation mechanism of radial electric field. Interactions between radial electric field, transport and structure in helical plasmas is discussed based on the experiments on Large Helical Device

  6. The generation and amplification of intergalactic magnetic fields in analogue laboratory experiments with high power lasers

    Science.gov (United States)

    Gregori, G.; Reville, B.; Miniati, F.

    2015-11-01

    The advent of high-power laser facilities has, in the past two decades, opened a new field of research where astrophysical environments can be scaled down to laboratory dimensions, while preserving the essential physics. This is due to the invariance of the equations of magneto-hydrodynamics to a class of similarity transformations. Here we review the relevant scaling relations and their application in laboratory astrophysics experiments with a focus on the generation and amplification of magnetic fields in cosmic environment. The standard model for the origin of magnetic fields is a multi stage process whereby a vanishing magnetic seed is first generated by a rotational electric field and is then amplified by turbulent dynamo action to the characteristic values observed in astronomical bodies. We thus discuss the relevant seed generation mechanisms in cosmic environment including resistive mechanism, collision-less and fluid instabilities, as well as novel laboratory experiments using high power laser systems aimed at investigating the amplification of magnetic energy by magneto-hydrodynamic (MHD) turbulence. Future directions, including efforts to model in the laboratory the process of diffusive shock acceleration are also discussed, with an emphasis on the potential of laboratory experiments to further our understanding of plasma physics on cosmic scales.

  7. Determining Data Quality for the NOvA Experiment

    Science.gov (United States)

    Murphy, Ryan; NOvA Collaboration Collaboration

    2016-03-01

    NOvA is a long-baseline neutrino oscillation experiment with two liquid scintillator filled tracking calorimeter detectors separated by 809 km. The detectors are located 14.6 milliradians off-axis of Fermilab's NuMI beam. The NOvA experiment is designed to measure the rate of electron-neutrino appearance out of the almost-pure muon-neutrino NuMI beam, with the data measured at the Near Detector being used to accurately determine the expected rate of the Far Detector. It is therefore very important to have automated and accurate monitoring of the data recorded by the detectors so any hardware, DAQ or beam issues arising in the 0.3 million (20k) channels of the far (near) detector which could effect this extrapolation technique are identified and the affected data removed from the physics analysis data set. This poster will cover the techniques and efficiency of selecting good data, describing the selections placed on different data and hardware levels.

  8. Radio frequency wave experiments on the MST reversed field pinch

    International Nuclear Information System (INIS)

    Forest, C.B.; Chattopadhyay, P.K.; Nornberg, M.D.; Prager, S.C.; Thomas, M.A.; Harvey, R.W.; Ram, A.K.

    1999-04-01

    Experiments, simulations, and theory all indicate that the magnetic fluctuations responsible for the poor confinement in the reversed field pinch (RFP) can be controlled by altering the radial profile of the current density. The magnetic fluctuations in the RFP are due to resistive MHD instabilities caused by current profile peaking; thus confinement in the RFP is ultimately the result of a misalignment between inductively driven current profiles and the stable current profiles characteristic of the Taylor state. If a technique such as rf current drive can be developed to non-inductively sustain a Taylor state (a current profile linearly stable to all tearing modes), the confinement of the RFP and its potential as a reactor concept are likely to increase. Whether there is a self-consistent path from poor confinement to greatly improved confinement through current profile modification is an issue for future experiments to address if and only if near term experiments can demonstrate: (1) coupling to and the propagation of rf waves in RFP plasmas, (2) efficient current drive, and (3) control of the power deposition which will make it possible to control the current profile. In this paper, modeling results and experimental plans are presented for two rf experiments which have the potential of satisfying these three goals: high-n parallel lower hybrid (LH) waves and electron Bernstein waves (EBWs)

  9. Jet Grouting. Control of execution and result parameters. Test fields - Experience in Chile

    International Nuclear Information System (INIS)

    Ayarza, P. M.; Vukotic, G.

    2014-01-01

    This article emphasizes the importance of Test Fields in project that includes the Jet Grouting technique. In particular, the Chilean experience is analyzed, where the Jet Grouting was first introduced by Pilots Terratest S. A. in the year 2010, only, only in 2011 the first project using jet columns was constructed. The versatilely of this technique allows its use in a wide variety of projects, for example, soil capacity improvement, settlement control, reduction of soil permeability and other environmental applications. Currently, the most common applications are underpinning existing foundations, ground improvement, lateral support of excavations, hydraulic barriers, slope stabilization, liquefaction control, among others. The Jet Grouting is one of the most demanding soil improvement technique and requires excellence in designing and execution engineers and other involved specialist. It is therefore essential to ensure exhaustive control to the execution and final parameters, in order to check that the product- Jet Grouting element-have the design properties, and implement modifications if necessary. Many authors strongly advises that if there is no comparable experience and even if there is, a Test Field of Jet Grouting elements has to be executed in site. This field consists in a nearby area with similar geotechnical conditions of the project, where Jet Grouting test columns will be constructed. This Test Field will allow selecting the most effective execution parameters and verifying that the final product has he correct design properties. (Author)

  10. Interpretation of field experiments on the flow of water and tracers through crystalline rock

    International Nuclear Information System (INIS)

    Hodgkinson, D.P.; Lever, D.A.; Robinson, P.C.; Bourke, P.J.

    1983-01-01

    This paper reviews recent work at Harwell on the interpretation of field experiments on the flow of water and tracers through crystalline rock. First a model for the radial transport of tracers through an isolated fracture is outlined and used to analyse a recent Swedish experiment at Finnsjoen. Secondly, the theoretical and experimental approach that is being used to quantify flow and dispersion through networks of fractures is described

  11. Regional co-operation in the nuclear field: The Nordic experience

    International Nuclear Information System (INIS)

    Marcus, F.R.

    1983-01-01

    Experience from 25 years of co-operation in the nuclear field between the Nordic countries is described. A pragmatic approach with a minimum of formalism is used. The co-operation takes place mainly through ''horizontal'' channels between corresponding bodies in the different countries - safety authorities, research institutions, electricity producers, etc. In addition, a ''vertical'' co-ordination between these different circles is accomplished through a Nordic Liaison Committee. The experience shows that valuable results can be obtained, mainly through rationalization and improved use of resources. Difficulties, which are inherent in international co-operation, can be reduced, provided that there is a strong political will, an efficient system to promote contacts, and a flexible financing scheme. Apart from the benefits obtained in each of the countries - whether or not it has its own nuclear power - particular advantages accrue when a ''Nordic group'' can present co-ordinated viewpoints on the international scene. (author)

  12. Independence and Interdependence: An Analysis of Pre-Service Candidates' Use of Focused Assignments on an Electronic Discussion Forum during the Initial Field Experience

    Science.gov (United States)

    Fisch, Audrey A.; Bennett, Deborah J.

    2011-01-01

    This article describes a case study using an electronic learning platform for creating an interactive learning community through asynchronous discussion to enhance the initial field experience of secondary math and English teacher candidates enrolled in Field Experience. We identified three problems with the field experience course--lack of…

  13. Physical model experiment for wave field measurements by means of laser Doppler vibrometer. Measurement of three components; Laser Doppler shindokei ni yoru butsuri model jikken. Hado sanseibun no kenshutsu

    Energy Technology Data Exchange (ETDEWEB)

    Nishizawa, O; Sato, T [Geological Survey of Japan, Tsukuba (Japan); Lei, X [DIA Consultant Co. Ltd., Tokyo (Japan)

    1997-05-27

    In this experiment, a beam incident from an oblique direction is reflected by a spherical lens toward the direction of incidence. When the surface of a matter is vibrated by elastic waves, the spherical lens comes into a translation motion that accompanies the vibration. It follows accordingly that the vibration on the surface of the matter may be detected by sensing the spherical lens travelling speed. Three components of the vibration may be determined if beams are focused at one spot from three directions. Detection of the S-wave component by LDV (laser Doppler vibrometer) discloses the complicated wave field in a heterogeneous material, and this physical model experiment may be utilized in various fields of study. For instance, information about problems that may surface in the field work may be collected beforehand in a physical model experiment for developing an S-wave-aided probing method. For the study of seismic wave propagation in a complicated three-dimensional ground structure, a numerical model is not enough, and a physical model experiment will be an effective method to fulfill the purpose. In the monitoring of cracks in a rock, again, not only elastic wave velocity but also waveform information collected from a physical model experiment should be fully utilized. 6 refs., 6 figs.

  14. Contributing to Sustainability Education of East Asian University Students through a Field Trip Experience: A Social-Ecological Perspective

    Directory of Open Access Journals (Sweden)

    Tae Kyung Yoon

    2016-10-01

    Full Text Available This study reports the effects of a field trip environmental education program with a social-ecological perspective on the experience and learning of university students from China, Japan, South Korea and Vietnam. The students visited Jeju Island, the Saemangeum Sea Dike, the Demilitarized Zone and Seoul, South Korea. Their experiences and learning about social-ecological interactions were analyzed using the new environmental paradigm test, an evaluation questionnaire, group presentations and individual reports. Across demographic characteristics, the participants believed the program fairly presented the concept of social-ecological systems. Some developed new ideas of social-ecological systems through interpreting, transforming and contextualizing their field trip experience based on prior knowledge bases; others compared the sites to case studies. They preferred the sites where social-ecological issues were clearly presented by well-preserved landscapes, successful environmental management or environmental conflict. The results show the need for an advanced multi-dimensional methodology to evaluate students’ learning through constructive processes. The program design of this study from planning to field trip and evaluation, the field site design in which regional site resources were organized in a social-ecological context and the analysis of participants’ learning and experiences could contribute to attempts to couple the social-ecological perspective with the practice of sustainability and environmental education in field trip design.

  15. Direct measurement of macroscopic electric fields produced by collective effects in electron-impact experiments

    International Nuclear Information System (INIS)

    Velotta, R.; Avaldi, L.; Camilloni, R.; Giammanco, F.; Spinelli, N.; Stefani, G.

    1996-01-01

    The macroscopic electric field resulting from the space charge produced in electron-impact experiments has been characterized by using secondary electrons of well-defined energy (e.g., Auger or autoionizing electrons) as a probe. It is shown that the measurement of the kinetic-energy shifts suffered by secondary electrons is a suitable tool for the analysis of the self-generated electric field in a low-density plasma. copyright 1996 The American Physical Society

  16. Teaching Ethics to Marketing and Logistics Majors: A Transformative Learning Experiment

    Science.gov (United States)

    Aguirre, Grant; Hyman, Michael R.; Goudge, Darrell; Genchev, Stefan; Carrell, Amy; Hamilton, Corey

    2017-01-01

    Within the context of a transformative learning field experiment, the ethical ideologies of marketing majors, logistics majors, and nonbusiness majors were found to differ. Based on this finding, a field experiment was conducted to determine the effect (if any) that ethics instruction has on marketing and logistics majors versus nonbusiness…

  17. Field and laboratory determination of a poly(vinyl/vinylidene chloride) additive in brick mortar.

    Science.gov (United States)

    Law, S L; Newman, J H; Ptak, F L

    1990-02-01

    A polymerized vinyl/vinylidene chloride additive, used in brick mortar during the 60s and 70s, is detected at the building site by the field method, which employs a commercially available chloride test strip. The field test results can then be verified by the laboratory methods. In one method, total chlorine in the mortar is determined by an oxygen-bomb method and the additive chloride is determined by difference after water-soluble chlorides have been determined on a separate sample. In the second method, the polymerized additive is extracted directly from the mortar with tetrahydrofuran (THF). The difference in weight before and after extraction of the additive gives the weight of additive in the mortar. Evaporation of the THF from the extract leaves a thin film of the polymer, which gives an infrared "fingerprint" spectrum characteristic of the additive polymer.

  18. A Grounded Theory of Preservice Music Educators' Lesson Planning Processes within Field Experience Methods Courses

    Science.gov (United States)

    Parker, Elizabeth Cassidy; Bond, Vanessa L.; Powell, Sean R.

    2017-01-01

    The purpose of this grounded theory study was to understand the process of field experience lesson planning for preservice music educators enrolled in choral, general, and instrumental music education courses within three university contexts. Data sources included multiple interviews, written responses, and field texts from 42 participants. Four…

  19. From Formal Expertise to Co-expertise: Experience in the Field of Protection against Radiation

    International Nuclear Information System (INIS)

    Lochard, Jacques

    2002-01-01

    As a result of the growing difficulties confronting the heads of public and private high-risk activities, expertise practices have changed radically over the past years in the areas of risk assessment and management. In answer to the erosion of the credibility and legitimacy of traditional 'scientific' expertise, new forms of expertise based on citizen participation have emerged, particularly in fields involving public trust. The author's aim is to analyse the main changes in the field of radiological protection, on the basis of his 25 years of experience in the field. In conclusion, the author discusses the independence of expert assessment, an issue central to the present debate on the organization and practice of expertise in the field of high-risk activities

  20. Chromatic discrimination: differential contributions from two adapting fields

    Science.gov (United States)

    Cao, Dingcai; Lu, Yolanda H.

    2012-01-01

    To test whether a retinal or cortical mechanism sums contributions from two adapting fields to chromatic discrimination, L/M discrimination was measured with a test annulus surrounded by an inner circular field and an outer rectangular field. A retinal summation mechanism predicted that the discrimination pattern would not change with a change in the fixation location. Therefore, the fixation was set either in the inner or the outer field in two experiments. When one of the adapting fields was “red” and the other was “green,” the adapting field where the observer fixated always had a stronger influence on chromatic discrimination. However, when one adapting field was “white” and the other was red or green, the white field always weighted more heavily than the other adapting field in determining discrimination thresholds, whether the white field or the fixation was in the inner or outer adapting field. These results suggest that a cortical mechanism determines the relative contributions from different adapting fields. PMID:22330364

  1. U.S. Army RDECOM-ARDEC's results of the TG-53 experiment and field test

    Science.gov (United States)

    Desai, Sachi V.; Morcos, Amir

    2009-05-01

    Herein is described the U.S. Army RDECOM-ARDEC's purpose and series of activities conducted at the 2008 NATO SET-093 TG-53 experiment and field test. The overall purpose of the field test as stated by SET-093 panel was to provide a baseline test capable of providing relevant scenarios and data regarding a variety of impulsive generated acoustic events. As organized, the field experiment also allowed the room o study sensor interoperability across multiple platforms and multi-national users via the spider communication framework/reporting structure. This multinational network maintained by the host ETBS with a standardized messaging format with specific goals for each participating organization. ARDEC's role and purpose for the test was to provide situational awareness via the Spider and associated messaging format to the ETBS command center while continuing to gather unique acoustic data from various vantage points. ARDEC had several deliverables for the TG-53 field experiment derived from the mission and spirit of the field test. The most relevant deliverable was to demonstrate sensor interoperability via the Spider network and provide situational awareness by describing the said mortar/artillery events. The second purpose revolved around a relevant environment algorithm validation of the muzzle blast discrimination for future UGS transition in particular the UTAMS II. The algorithm validation information remained internal to the specific data acquisition system and not broadcasted out on the Spider network. The TG-53 field experiments provided the added opportunity to further test and refine the algorithm based on the discrete wavelet transform (DWT) and multiresolution analysis. These techniques are used to classify and reliably discriminates between launch and impact artillery and/or mortar events via acoustic signals produced during detonation. Distinct characteristics are found within the acoustic signatures since impact events emphasize concussive and

  2. Mapping and correcting respiration-induced field changes in the brain using fluorine field probes

    DEFF Research Database (Denmark)

    Andersen, Mads; Madsen, Kristoffer; Hanson, Lars G.

    2014-01-01

    strength values from signal phase by linear fitting. Ahead of imaging, the field probe positions were determined for each subject, by applying known gradients in all three dimensions while measuring with the field probes. Experiments: Measurements were performed in 4 male subjects instructed to hold...... software was updated with f0 and first order shim values, before the acquisition of every volume. Evaluation: To assess whether the dynamic field changes were captured by the field probe data, the field probe fitted fields were subtracted from the scanner B0 maps to model shimming. We then assessed whether......Purpose. Breathing induced dynamic B0 field perturbations in the head can lead to artefacts in ultra-high field MR by causing line broadening in spectroscopy and signal dropout, ghosting, displacement artifacts and blurring in imaging. It has recently been proposed to continuously stabilize...

  3. Survival and leaching of Tetracycline resistant bacteria and fecal indicators from manure in field scale experiments

    DEFF Research Database (Denmark)

    Bech, Tina; Amin, Mostofa; Lægdsmand, Mette

    The spreading of manure on agricultural land is an economic and practical solution for improving soil quality; however, animal manure frequently contains zoonotic pathogenic bacteria, such as certain Eschericia coli, Salmonella spp. and Campylobacter spp. The present experiment was conducted...... as a large multidisciplinary project. Pig manure with a natural content of Tetracycline resistant bacteria and fecal indicator organisms was followed in soil columns and a field scale experiment. In the field experiment pig manure was injected into agricultural soil. The distribution and survival of natural...... occurring indicator bacteria around a manure slurry slit in the soil was followed. During a period of two months, sections of soils with different distance to the manure string were assayed to obtain information on survival and spread of bacteriophage, faecal indicators (Enterococci, Bacterioides, E. coli...

  4. The behavior of a type-II superconductor Nb in a magnetic field as investigated in polarized-neutron transmission experiments

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Dokukin, E.B.; Kozhevnikov, S.V.; Nikitenko, Yu.V.; Petrenko, A.V.

    1995-01-01

    The type-II superconducting polycrystal Nb was investigated on the SPN-1 polarized-neutron spectrometer at the high-intensity pulsed reactor IBR-2 at Dubna. In polarized-neutron transmission experiments the magnetic-field dependence of the neutron beam polarization was measured. Experiments were performed over a wide magnetic-field range from 0 to H c2 at a temperature of 4.8 K. A quasiperiodic variation of the neutron depolarization as a function of magnetic-field strength was observed. (orig.)

  5. ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Leung, L Ruby [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Cloud-Aerosol-Precipitation Experiment (ACAPEX) field campaign contributes to CalWater 2015, a multi-agency field campaign that aims to improve understanding of atmospheric rivers and aerosol sources and transport that influence cloud and precipitation processes. The ultimate goal is to reduce uncertainties in weather predictions and climate projections of droughts and floods in California. With the DOE G-1 aircraft and ARM Mobile Facility 2 (AMF2) well equipped for making aerosol and cloud measurements, ACAPEX focuses specifically on understanding how aerosols from local pollution and long-range transport affect the amount and phase of precipitation associated with atmospheric rivers. ACAPEX took place between January 12, 2015 and March 8, 2015 as part of CalWater 2015, which included four aircraft (DOE G-1, National Oceanic and Atmospheric Administration [NOAA] G-IV and P-3, and National Aeronautics and Space Administration [NASA] ER-2), the NOAA research ship Ron Brown, carrying onboard the AMF2, National Science Foundation (NSF)-sponsored aerosol and precipitation measurements at Bodega Bay, and the California Department of Water Resources extreme precipitation network.

  6. Field-reversed experiments (FRX) on compact toroids

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-11-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10/sup 15/ cm/sup -3/ to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10/sup 15/ cm/sup -3/. Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 ..mu..sec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed.

  7. Field-reversed experiments (FRX) on compact toroids

    International Nuclear Information System (INIS)

    Armstrong, W.T.; Linford, R.K.; Lipson, J.; Platts, D.A.; Sherwood, E.G.

    1981-01-01

    Equilibrium, stability, and confinement properties of compact toroids produced in field-reversed theta-pinch experiments (FRX) are reported. Two experimental facilities, FRX-A and FRX-B, have been used to study highly elongated compact toroid plasmas confined in a purely poloidal field geometry. Spatial scans and fill pressure scaling of the equilibrium plasma parameters are presented. Plasma conditions range from T/sub e/approx.150 eV, T/sub i/approx.800 eV, n/sub m/approx.1 x 10 15 cm -3 to T/sub e/approx.100 eV, T/sub i/approx.150 eV, n/sub m/approx.4 x 10 15 cm -3 . Typical confined plasma dimensions are: major radius Rapprox.4 cm, minor radius aapprox.2 cm, and total length 35--50 cm. The plasma configuration remains in a stable equilibrium for up to 50 μsec followed by the destructive n = 2 rotational instability. The stable period prior to the onset of the rotational mode is up to one hundred times greater than characteristic Alfven transit times of the plasma. This stable period increases and the mode growth rate decreases with increased a/rho/sub i/ (where rho/sub i/ is the ion gyroradius). Agreement of experimental and theoretical mode frequencies for the instability is observed. Preferential particle loss has been proposed as a likely cause of rotation. The particle inventory at the onset of the instability is consistent with this hypothesis. The particle loss rate is also consistent with the predicted anomalous transport near the separatrix. Contributions to rotational instability from diffusion, end-shorting, equipartition, and compression are also discussed

  8. Determination of the Performance Parameters of a Spectrophotometer: An Advanced Experiment.

    Science.gov (United States)

    Cope, Virgil W.

    1978-01-01

    Describes an advanced analytical chemistry laboratory experiment developed for the determination of the performance parameters of a spectrophotometer. Among the parameters are the baseline linearity with wavelength, wavelength accuracy and respectability, stray light, noise level and pen response time. (HM)

  9. Extended-gate field-effect transistor (EG-FET) with molecularly imprinted polymer (MIP) film for selective inosine determination.

    Science.gov (United States)

    Iskierko, Zofia; Sosnowska, Marta; Sharma, Piyush Sindhu; Benincori, Tiziana; D'Souza, Francis; Kaminska, Izabela; Fronc, Krzysztof; Noworyta, Krzysztof

    2015-12-15

    A novel recognition unit of chemical sensor for selective determination of the inosine, renal disfunction biomarker, was devised and prepared. For that purpose, inosine-templated molecularly imprinted polymer (MIP) film was deposited on an extended-gate field-effect transistor (EG-FET) signal transducing unit. The MIP film was prepared by electrochemical polymerization of bis(bithiophene) derivatives bearing cytosine and boronic acid substituents, in the presence of the inosine template and a thiophene cross-linker. After MIP film deposition, the template was removed, and was confirmed by UV-visible spectroscopy. Subsequently, the film composition was characterized by spectroscopic techniques, and its morphology and thickness were determined by AFM. The finally MIP film-coated extended-gate field-effect transistor (EG-FET) was used for signal transduction. This combination is not widely studied in the literature, despite the fact that it allows for facile integration of electrodeposited MIP film with FET transducer. The linear dynamic concentration range of the chemosensor was 0.5-50 μM with inosine detectability of 0.62 μM. The obtained detectability compares well to the levels of the inosine in body fluids which are in the range 0-2.9 µM for patients with diagnosed diabetic nephropathy, gout or hyperuricemia, and can reach 25 µM in certain cases. The imprinting factor for inosine, determined from piezomicrogravimetric experiments with use of the MIP film-coated quartz crystal resonator, was found to be 5.5. Higher selectivity for inosine with respect to common interferents was also achieved with the present molecularly engineered sensing element. The obtained analytical parameters of the devised chemosensor allow for its use for practical sample measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Preliminary investigation on determination of radionuclide distribution in field tracing test site

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Mukai, Masayuki; Takebe, Shinichi; Guo Zede; Li Shushen; Kamiyama, Hideo.

    1993-12-01

    Field tracing tests for radionuclide migration have been conducted by using 3 H, 60 Co, 85 Sr and 134 Cs, in the natural unsaturated loess zone at field test site of China Institute for Radiation Protection. It is necessary to obtain confidable distribution data of the radionuclides in the test site, in order to evaluate exactly the migration behavior of the radionuclides in situ. An available method to determine the distribution was proposed on the basis of preliminary discussing results on sampling method of soils from the test site and analytical method of radioactivity in the soils. (author)

  11. A SOCIAL MEDIA CAMPAIGN APPLICATION IN A MARKETING FIELD EXPERIENCE COURSE

    OpenAIRE

    Mine Ucok Hughes

    2014-01-01

    Most university students today use social media daily, are knowledgeable about a myriad of applications, and can navigate numerous platforms, such as Facebook and Twitter. Despite their affinity for social media, however, it is not clear whether or not they understand how social media can be used to create effective marketing strategies. This paper describes a social media assignment that was incorporated into a marketing field experience course for undergraduate students. The aim of the pape...

  12. Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field.

    Science.gov (United States)

    Sladkov, Maksym; Bakker, M P; Chaubal, A U; Reuter, D; Wieck, A D; van der Wal, C H

    2011-04-01

    We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film. © 2011 American Institute of Physics

  13. Advanced Biasing Experiments on the C-2 Field-Reversed Configuration Device

    Science.gov (United States)

    Thompson, Matthew; Korepanov, Sergey; Garate, Eusebio; Yang, Xiaokang; Gota, Hiroshi; Douglass, Jon; Allfrey, Ian; Valentine, Travis; Uchizono, Nolan; TAE Team

    2014-10-01

    The C-2 experiment seeks to study the evolution, heating and sustainment effects of neutral beam injection on field-reversed configuration (FRC) plasmas. Recently, substantial improvements in plasma performance were achieved through the application of edge biasing with coaxial plasma guns located in the divertors. Edge biasing provides rotation control that reduces instabilities and E × B shear that improves confinement. Typically, the plasma gun arcs are run at ~ 10 MW for the entire shot duration (~ 5 ms), which will become unsustainable as the plasma duration increases. We have conducted several advanced biasing experiments with reduced-average-power plasma gun operating modes and alternative biasing cathodes in an effort to develop an effective biasing scenario applicable to steady state FRC plasmas. Early results show that several techniques can potentially provide effective, long-duration edge biasing.

  14. The use of single-crystal iron frames in transient field measurements

    International Nuclear Information System (INIS)

    Zalm, P.C.; Laan, J. van der; Middelkoop, G. van

    1979-01-01

    Single-crystal Fe frames have been investigated for use as a ferromagnetic backing in transient magnetic field experiments. For this purpose the surface magnetization as a function of applied magnetic field has been determined with the magneto-optical Kerr effect. The frames, which have two sides parallel to the crystal axis, can be fully magnetized at low external fields such that fringing fields are negligibly small. These single-crystal Fe backings have been used in several transient magnetic field experiments. Comparison of the measured precession angles with previous results, obtained in polycrystalline Fe foils at high external magnetic fields, shows that the single-crystal backings are satisfactory. After extended periods of heavy-ion bombardment the crystals exhibited no radiation damage effects. The absence of fringing fields leads to a reduction of a factor of four in the measuring time for transient field experiments. (Auth.)

  15. Randomized field experiments for program planning, development, and evaluation: an illustrative bibliography.

    Science.gov (United States)

    Boruch, R F; Mcsweeny, A J; Soderstrom, E J

    1978-11-01

    This bibliography lists references to over 300 field experiments undertaken in schools, hospitals, prisons, and other social settings, mainly in the U.S. The list is divided into 10 major categories corresponding to the type of program under examination. They include: criminal and civil justice programs, mental health, training and education, mass media, information collection, utilization, commerce and industry, welfare, health, and family planning. The main purpose of the bibliography is to provide evidence on feasibility and scope of randomized field tests, since despite their advantages, it is not always clear from managerial, political, and other constraints on research that they can be mounted. Dates of publications range from 1944 to 1978.

  16. An orbit determination algorithm for small satellites based on the magnitude of the earth magnetic field

    Science.gov (United States)

    Zagorski, P.; Gallina, A.; Rachucki, J.; Moczala, B.; Zietek, S.; Uhl, T.

    2018-06-01

    Autonomous attitude determination systems based on simple measurements of vector quantities such as magnetic field and the Sun direction are commonly used in very small satellites. However, those systems always require knowledge of the satellite position. This information can be either propagated from orbital elements periodically uplinked from the ground station or measured onboard by dedicated global positioning system (GPS) receiver. The former solution sacrifices satellite autonomy while the latter requires additional sensors which may represent a significant part of mass, volume, and power budget in case of pico- or nanosatellites. Hence, it is thought that a system for onboard satellite position determination without resorting to GPS receivers would be useful. In this paper, a novel algorithm for determining the satellite orbit semimajor-axis is presented. The methods exploit only the magnitude of the Earth magnetic field recorded onboard by magnetometers. This represents the first step toward an extended algorithm that can determine all orbital elements of the satellite. The method is validated by numerical analysis and real magnetic field measurements.

  17. Determination of the electric field strength of filamentary DBDs by CARS-based four-wave mixing

    Science.gov (United States)

    Böhm, P.; Kettlitz, M.; Brandenburg, R.; Höft, H.; Czarnetzki, U.

    2016-10-01

    It is demonstrated that a four-wave mixing technique based on coherent anti-Stokes Raman spectroscopy (CARS) can determine the electric field strength of a pulsed-driven filamentary dielectric barrier discharge (DBD) of 1 mm gap, using hydrogen as a tracer medium in nitrogen at atmospheric pressure. The measurements are presented for a hydrogen admixture of 10%, but even 5% H2 admixture delivers sufficient infrared signals. The lasers do not affect the discharge by photoionization or by other radiation-induced processes. The absolute values of the electric field strength can be determined by the calibration of the CARS setup with high voltage amplitudes below the ignition threshold of the arrangement. This procedure also enables the determination of the applied breakdown voltage. The alteration of the electric field is observed during the internal polarity reversal and the breakdown process. One advantage of the CARS technique over emission-based methods is that it can be used independently of emission, e.g. in the pre-phase and in between two consecutive discharges, where no emission occurs at all.

  18. NASA Cold Land Processes Experiment (CLPX 2002/03): Field measurements of snowpack properties and soil moisture

    Science.gov (United States)

    Kelly Elder; Don Cline; Glen E. Liston; Richard Armstrong

    2009-01-01

    A field measurement program was undertaken as part NASA's Cold Land Processes Experiment (CLPX). Extensive snowpack and soil measurements were taken at field sites in Colorado over four study periods during the two study years (2002 and 2003). Measurements included snow depth, density, temperature, grain type and size, surface wetness, surface roughness, and...

  19. Characteristics and parameters of bed-load movement for multi-bar near-shore zone on the base of tracer field experiments

    International Nuclear Information System (INIS)

    Wierzchnicki, R.

    1997-01-01

    The radiotracer method for field investigation of marine bed sediments in Baltic Sea near-shore zone has been elaborated and successfully used. The artificial sand made of special glass containing Ir-192 and quartz like density has been used as a tracer. The field experiments have been carried out at Coastal Station of the Institute of Hydroengineering in Lubiatowo. The tracer movement has been observed at different weather and wave conditions. On the base of obtained data the next characteristics and parameters of sand transport have been defined and discussed: critical velocities of sand grains; sediment velocities versus the long shore current; thickness of the layer transported; intensity of the transport. For the purpose of coastal engineering practice the global transport intensity in the multi bar-coastal zone conditions has been determined as a function of main parameters describing breaking waves (height and propagation angle)

  20. Evaluating the soil physical quality under long-term field experiments in Southern Italy

    Science.gov (United States)

    Castellini, Mirko; Stellacci, Anna Maria; Iovino, Massimo; Rinaldi, Michele; Ventrella, Domenico

    2017-04-01

    expected as both indicators depends on soil water contents at saturation and field capacity. Our results reinforce the suggestion that one of the two indicators can be neglected (Cullotta et al., 2016) even if further investigations are necessary to choose the most accurate and/or widely applicable indicator since different optimal ranges were suggested in literature. A positive significant correlation was also generally found between PMAC and AC. PCA analysis identified RFC and AC as the main indicators that explain most of the data variation. When the data collected at the different sampling dates were pooled together, in both experiments the first principal component explained the highest proportion of total variance (67.9% and 81.5%, respectively for residue management and tillage) and RFC showed the highest loadings, followed by AC and PMAC. SDA provided consistent results and RFC was selected as the main variable to assess the effects of tillage. Conversely, the residue management had no effect on SPQ as indicated by negligible differences between indicators. Finally, our results suggest that RFC always reached optimal and steady values between April and June. *The work was supported by the projects "STRATEGA, Sperimentazione e TRAsferimento di TEcniche innovative di aGricoltura conservativA", financed by Regione Puglia - Servizio Agricoltura, and "DESERT, Low-cost water desalination and sensor technology compact module" financed by ERANET-WATERWORKS 2014. References Castellini, M., M. Niedda, M. Pirastru, and D. Ventrella. 2014. Temporal changes of soil physical quality under two residue management systems. Soil Use Management. 30:423-434. doi:10.1111/sum.12137 Cullotta, S., V. Bagarello, G. Baiamonte, G. Gugliuzza, M. Iovino, D.S. La Mela Veca, F. Maetzke, V. Palmeri, and S. Sferlazza. 2016. Comparing Different Methods to Determine Soil Physical Quality in a Mediterranean Forest and Pasture Land. Soil Sci. Soc. Am. J. 80:1038-1056. doi:10.2136/sssaj2015.12.0447

  1. Application verification research of cloud computing technology in the field of real time aerospace experiment

    Science.gov (United States)

    Wan, Junwei; Chen, Hongyan; Zhao, Jing

    2017-08-01

    According to the requirements of real-time, reliability and safety for aerospace experiment, the single center cloud computing technology application verification platform is constructed. At the IAAS level, the feasibility of the cloud computing technology be applied to the field of aerospace experiment is tested and verified. Based on the analysis of the test results, a preliminary conclusion is obtained: Cloud computing platform can be applied to the aerospace experiment computing intensive business. For I/O intensive business, it is recommended to use the traditional physical machine.

  2. The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

    International Nuclear Information System (INIS)

    Podulka, W.J.; Greenly, J.B.; Anderson, D.E.; Glidden, S.C.; Hammer, D.A.; Omelchenko, Yu.A.; Sudan, R.N.

    1996-01-01

    The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10 17 protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs

  3. The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

    Energy Technology Data Exchange (ETDEWEB)

    Podulka, W J; Greenly, J B; Anderson, D E; Glidden, S C; Hammer, D A; Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

    1997-12-31

    The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10{sup 17} protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs.

  4. Pyranometer offsets triggered by ambient meteorology: insights from laboratory and field experiments

    OpenAIRE

    S. M. Oswald; H. Pietsch; D. J. Baumgartner; P. Weihs; H. E. Rieder

    2017-01-01

    This study investigates effects of ambient meteorology on the accuracy of radiation measurements performed with pyranometers contained in various heating/ventilation systems (HV-systems). It focuses particularly on instrument offsets observed following precipitation events. To quantify pyranometer responses to precipitation, a series of controlled laboratory experiments as well as two targeted field campaigns were performed in 2016. The results indicate that precipitation (as simulated by spr...

  5. Numerical Simulation of the Borehole Magnetic Field for Resolving the Possible Rotation of Tectonic Basins and Plates during ICDP and IODP Experiments

    Science.gov (United States)

    Lee, S. M.; Parq, J. H.

    2017-12-01

    An accurate measurement of magnetic field inside the borehole, together with a right set of paleomagnetic measurements on the recovered core samples, should allow one to resolve important elements such as the rotation of the basin or the plate on which the basin is located. The ability to resolve the rotation of the basin can be crucial during drilling experiments by International Continental Scientific Drilling Program (ICDP) and International Ocean Discovery Program (IODP). A good example where the rotation is a central question is the Philippine Sea Plate, which is thought to have rotated about 90° clockwise during the last 55 million years. Despite the significance, previous borehole magnetometers were not accurate enough to achieve such a goal because, among various technical issues, determining the orientation of the sensor inside the borehole to a very high level of accuracy was not easy. The next-generation (third-generation) borehole magnetometer (3GBM) was developed to overcome this difficulty and to bring paleomagnetic investigations to a new level. Even with the new development, however, there are still concerns whether the new instrument can really resolve the rotation because the magnetic field anomalies generated by the sediment is generally very low. In this paper, we present numerical simulations based on finite element method of the magnetic field inside the borehole that were conducted as part of a test to demonstrate that, despite low levels of magnetization, the magnetic fields can be resolved. The results also served as an important input on the design requirements of the borehole magnetometer. Various cases were considered, including the situation where the sedimentary layer is horizontal and inclined. We also explored the cases where volcanic sills were present within the sedimentary layer as they may provide a greater magnetic signature than having sediment alone, and thus improving our chances of determining the rotation. Simulations are

  6. Determination of two- and three-dimensional radiation fields for neutron radiotherapy planning

    International Nuclear Information System (INIS)

    Boehm, J.K.

    1986-01-01

    The thesis deals with the computerized investigations for fast neutron radiotherapy planning, explaining the calculation and modelling of local dose distributions in patients as a result of mixed neutron and gamma radiation fields. For a computed irradiation program (elaborated for instance by the COMRAD program system), dose distribution functions are required for the simulation of multi-field or moving beam irradiations, the functions being derived semi-empirically by non-linear regression. The necessary data on stationary field doses are derived by measurements or by computed simulation with specific transport programs from the nuclear engineering sector. Transport calculations show the effects of inhomogeneities in the patient's body on the dose distribution. The determined, strong inhomogneity effects (lungs, head) have to be taken into account as precisely as possible in order to achieve optimum irradiation planning. (orig./HP) [de

  7. Using Teleducation and Field Experiences to further the Understanding of Coastal Environments

    Science.gov (United States)

    Macko, S. A.; Szuba, T. A.; Shugart, H.

    2007-05-01

    This project is an outreach and education program with a partner in the K-12 schools at Accomack County on the Eastern Shore of Virginia. It endeavors to build a community knowledgeable of the importance the ocean plays daily in our lives, and our own impact on the ocean. It is an program built in stages that: 1) Establish high speed live interactive classes (teleducation) linkages with the Eastern Shore High Schools with earth science teachers enabling them to remotely participate in University of Virginia classes in Oceanography (designed on a faculty development basis or acquire NSTA certification in Earth Science Education, as well as participation by seniors in the Accomack Schools; 2) Establish field experiences for teachers and selected students that involve travel to both the Virginia Coast Reserve Long Term Ecological Research (VCR/LTER) Center, UVA to observe first- hand the science programs at those locations and participate in cutting edge coastal marine research efforts. These experiences improve student understanding of the ocean-atmosphere biogeophysical system and encourage students to explore the sciences as a field of study and possible vocation. Advanced high school students and science teachers from Accomack County Public Schools participated in an experience involving field and laboratory methods employed in a NSF-sponsored study of the coupled natural-human dynamics on the Eastern Shore of Virginia over the past 500 years (NSF-Biocomplexity). Students and teachers worked with researchers of the VCR facility in Oyster, VA, collected sediment cores from Chesapeake Bay tributaries, and traveled to the Organic Geochemistry Laboratory at UVA, in Charlottesville, VA to prepare and analyze samples for isotopic and palynological information. In a first of its kind connectivity, in June/July, 2006, using high speed internet connections, a summer class in Oceanography was live, interactively broadcast (teleducation) from UVA to Arcadia High School on

  8. Formation of toroidal pre-heat plasma without residual magnetic field for high-beta pinch experiments

    International Nuclear Information System (INIS)

    Ikeda, Nagayasu; Tamaru, Ken; Nagata, Akiyoshi.

    1979-01-01

    Formation of toroidal pre-heat plasma was studied. The pre-heat plasma without residual magnetic field was made by chopping the current for pre-heat, A small toroidal-pinch system was used for the experiment. The magnetic field was measured with a magnetic probe. One turn loop was used for the measurement of the toroidal one-turn electric field. A pair of Rogoski coil was used for the measurement of plasma current. The dependence of residual magnetic field on chopping time was measured. By fast chopping of the primary current in the pre-heating circuit, the poloidal magnetic field was reduced to several percent within 5 microsecond. After chopping, no instability was observed in the principal discharge plasma produced within several microsecond. As the conclusion, it can be said that the control of residual field can be made by current chopping. (Kato, T.)

  9. Load shift incentives for household demand response: A model to evaluate effects from a Danish field experiment

    DEFF Research Database (Denmark)

    Katz, Jonas; Møller Andersen, Frits; Morthorst, Poul Erik

    2015-01-01

    We use a long-term electricity market equilibrium model to assess the impact of variable price products for household electricity customers. The analysed product structures resemble a rebate provided to customers within a field experiment in Southern Denmark. The developed model provides a clearer...... picture of what to expect from household demand response under spot pricing schemes as compared and simplified product schemes; it also prepares for interpreting the field experiment results. Using preliminary assumptions we estimate both short-term and long-term welfare effects of a shift of customers...

  10. Determination of tin equilibrium isotope fractionation factors from synchrotron radiation experiments

    NARCIS (Netherlands)

    Polyakov, VB; Mineev, SD; Clayton, RN; Hu, G; Mineev, KS

    2005-01-01

    A method of determination of the reduced isotopic partition function ratio (beta-factor) from the partial density of state (PDOS) obtained by inelastic nuclear resonant X-ray scattering (INRXS) in synchrotron radiation experiments has been established. The method has been demonstrated by the example

  11. Simple-to-prepare multipoint field emitter

    Science.gov (United States)

    Sominskii, G. G.; Taradaev, E. P.; Tumareva, T. A.; Mishin, M. V.; Kornishin, S. Yu.

    2015-07-01

    We investigate multitip field emitters prepared by electroerosion treatment of the surface of molybdenum samples. Their characteristics are determined for operation with a protecting activated fullerene coating. Our experiments indicate that such cathodes are promising for high-voltage electron devices operating in technical vacuum.

  12. Colloid Facilitated Transport of Radioactive Cations in the Vadose Zone: Field Experiments Oak Ridge

    Energy Technology Data Exchange (ETDEWEB)

    James E. Saiers

    2012-09-20

    The overarching goal of this study was to improve understanding of colloid-facilitated transport of radioactive cations through unsaturated soils and sediments. We conducted a suite of laboratory experiments and field experiments on the vadose-zone transport of colloids, organic matter, and associated contaminants of interest to the U.S. Department of Energy (DOE). The laboratory and field experiments, together with transport modeling, were designed to accomplish the following detailed objectives: 1. Evaluation of the relative importance of inorganic colloids and organic matter to the facilitation of radioactive cation transport in the vadose zone; 2. Assessment of the role of adsorption and desorption kinetics in the facilitated transport of radioactive cations in the vadose zone; 3. Examination of the effects of rainfall and infiltration dynamics and in the facilitated transport of radioactive cations through the vadose zone; 4. Exploration of the role of soil heterogeneity and preferential flow paths (e.g., macropores) on the facilitated transport of radioactive cations in the vadose zone; 5. Development of a mathematical model of facilitated transport of contaminants in the vadose zone that accurately incorporates pore-scale and column-scale processes with the practicality of predicting transport with readily available parameters.

  13. Field experiment provides ground truth for surface nuclear magnetic resonance measurement

    Science.gov (United States)

    Knight, R.; Grunewald, E.; Irons, T.; Dlubac, K.; Song, Y.; Bachman, H.N.; Grau, B.; Walsh, D.; Abraham, J.D.; Cannia, J.

    2012-01-01

    The need for sustainable management of fresh water resources is one of the great challenges of the 21st century. Since most of the planet's liquid fresh water exists as groundwater, it is essential to develop non-invasive geophysical techniques to characterize groundwater aquifers. A field experiment was conducted in the High Plains Aquifer, central United States, to explore the mechanisms governing the non-invasive Surface NMR (SNMR) technology. We acquired both SNMR data and logging NMR data at a field site, along with lithology information from drill cuttings. This allowed us to directly compare the NMR relaxation parameter measured during logging,T2, to the relaxation parameter T2* measured using the SNMR method. The latter can be affected by inhomogeneity in the magnetic field, thus obscuring the link between the NMR relaxation parameter and the hydraulic conductivity of the geologic material. When the logging T2data were transformed to pseudo-T2* data, by accounting for inhomogeneity in the magnetic field and instrument dead time, we found good agreement with T2* obtained from the SNMR measurement. These results, combined with the additional information about lithology at the site, allowed us to delineate the physical mechanisms governing the SNMR measurement. Such understanding is a critical step in developing SNMR as a reliable geophysical method for the assessment of groundwater resources.

  14. The large-s field-reversed configuration experiment

    International Nuclear Information System (INIS)

    Hoffman, A.L.; Carey, L.N.; Crawford, E.A.; Harding, D.G.; DeHart, T.E.; McDonald, K.F.; McNeil, J.L.; Milroy, R.D.; Slough, J.T.; Maqueda, R.; Wurden, G.A.

    1993-01-01

    The Large-s Experiment (LSX) was built to study the formation and equilibrium properties of field-reversed configurations (FRCs) as the scale size increases. The dynamic, field-reversed theta-pinch method of FRC creation produces axial and azimuthal deformations and makes formation difficult, especially in large devices with large s (number of internal gyroradii) where it is difficult to achieve initial plasma uniformity. However, with the proper technique, these formation distortions can be minimized and are then observed to decay with time. This suggests that the basic stability and robustness of FRCs formed, and in some cases translated, in smaller devices may also characterize larger FRCs. Elaborate formation controls were included on LSX to provide the initial uniformity and symmetry necessary to minimize formation disturbances, and stable FRCs could be formed up to the design goal of s = 8. For x ≤ 4, the formation distortions decayed away completely, resulting in symmetric equilibrium FRCs with record confinement times up to 0.5 ms, agreeing with previous empirical scaling laws (τ∝sR). Above s = 4, reasonably long-lived (up to 0.3 ms) configurations could still be formed, but the initial formation distortions were so large that they never completely decayed away, and the equilibrium confinement was degraded from the empirical expectations. The LSX was only operational for 1 yr, and it is not known whether s = 4 represents a fundamental limit for good confinement in simple (no ion beam stabilization) FRCs or whether it simply reflects a limit of present formation technology. Ideally, s could be increased through flux buildup from neutral beams. Since the addition of kinetic or beam ions will probably be desirable for heating, sustainment, and further stabilization of magnetohydrodynamic modes at reactor-level s values, neutral beam injection is the next logical step in FRC development. 24 refs., 21 figs., 2 tabs

  15. Theory, Experimental Design, and Econometrics Are Complementary (And So Are Lab and Field Experiments)

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten; Rutström, E. Elisabet

    2015-01-01

    This book confronts and debates the issues faced by the growing field of experimental economics. For example, as experimental work attempts to test theory, it raises questions about the proper relationship between theory and experiments. As experimental results are used to inform policy...

  16. [Runoff Pollution Experiments of Paddy Fields Under Different Irrigation Patterns].

    Science.gov (United States)

    Zhou, Jing-wen; Su, Bao-lin; Huang, Ning-bo; Guan, Yu-tang; Zhao, Kun

    2016-03-15

    To study runoff and non-point source pollution of paddy fields and to provide a scientific basis for agricultural water management of paddy fields, paddy plots in the Jintan City and the Liyang City were chosen for experiments on non-point source pollution, and flood irrigation and intermittent irrigation patterns were adopted in this research. The surface water level and rainfall were observed during the growing season of paddies, and the runoff amount from paddy plots and loads of total nitrogen (TN) and total phosphorus (TP) were calculated by different methods. The results showed that only five rain events of totally 27 rainfalls and one artificially drainage formed non-point source pollution from flood irrigated paddy plot, which resulted in a TN export coefficient of 49.4 kg · hm⁻² and a TP export coefficient of 1.0 kg · hm⁻². No any runoff event occurred from the paddy plot with intermittent irrigation even in the case of maximum rainfall of 95.1 mm. Runoff from paddy fields was affected by water demands of paddies and irrigation or drainage management, which was directly correlated to surface water level, rainfall amount and the lowest ridge height of outlets. Compared with the flood irrigation, intermittent irrigation could significantly reduce non-point source pollution caused by rainfall or artificial drainage.

  17. Field experiment for determining lead accumulation in rice grains of different genotypes and correlation with iron oxides deposited on rhizosphere soil.

    Science.gov (United States)

    Lai, Yu-Cheng; Syu, Chien-Hui; Wang, Pin-Jie; Lee, Dar-Yuan; Fan, Chihhao; Juang, Kai-Wei

    2018-01-01

    Paddy rice (Oryza sativa L.) is a major staple crop in Asia. However, heavy metal accumulation in paddy soil poses a health risk for rice consumption. Although plant uptake of Pb is usually low, Pb concentrations in rice plants have been increasing with Pb contamination in paddy fields. It is known that iron oxide deposits in the rhizosphere influence the absorption of soil Pb by rice plants. In this study, 14 rice cultivars bred in Taiwan, including ten japonica cultivars (HL21, KH145, TC192, TK9, TK14, TK16, TN11, TNG71, TNG84, and TY3) and four indica cultivars (TCS10, TCS17, TCSW2, and TNGS22), were used in a field experiment. We investigated the genotypic variation in rice plant Pb in relation to iron oxides deposited in the rhizosphere, as seen in a suspiciously contaminated site in central Taiwan. The results showed that the cultivars TCSW2, TN11, TNG71, and TNG84 accumulated brown rice Pb exceeding the tolerable level of 0.2mgkg -1 . In contrast, the cultivars TNGS22, TK9, TK14, and TY3 accumulated much lower brown rice Pb (iron oxides deposited on the rhizosphere soil show stronger affinity to soil-available Pb than those on the root surface to form iron plaque. The relative tendency of Pb sequestration toward rhizosphere soil was negatively correlated with the Pb concentrations in brown rice. The iron oxides deposited on the rhizosphere soil but not on the root surface to form iron plaque dominate Pb sequestration in the rhizosphere. Therefore, the enhancement of iron oxide deposits on the rhizosphere soil could serve as a barrier preventing soil Pb on the root surface and result in reduced Pb accumulation in brown rice. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The BLLAST field experiment: Boundary-Layer Late Afternoon and Sunset Turbulence

    Science.gov (United States)

    Lothon, M.; Lohou, F.; Pino, D.; Couvreux, F.; Pardyjak, E. R.; Reuder, J.; Vilà-Guerau de Arellano, J.; Durand, P.; Hartogensis, O.; Legain, D.; Augustin, P.; Gioli, B.; Lenschow, D. H.; Faloona, I.; Yagüe, C.; Alexander, D. C.; Angevine, W. M.; Bargain, E.; Barrié, J.; Bazile, E.; Bezombes, Y.; Blay-Carreras, E.; van de Boer, A.; Boichard, J. L.; Bourdon, A.; Butet, A.; Campistron, B.; de Coster, O.; Cuxart, J.; Dabas, A.; Darbieu, C.; Deboudt, K.; Delbarre, H.; Derrien, S.; Flament, P.; Fourmentin, M.; Garai, A.; Gibert, F.; Graf, A.; Groebner, J.; Guichard, F.; Jiménez, M. A.; Jonassen, M.; van den Kroonenberg, A.; Magliulo, V.; Martin, S.; Martinez, D.; Mastrorillo, L.; Moene, A. F.; Molinos, F.; Moulin, E.; Pietersen, H. P.; Piguet, B.; Pique, E.; Román-Cascón, C.; Rufin-Soler, C.; Saïd, F.; Sastre-Marugán, M.; Seity, Y.; Steeneveld, G. J.; Toscano, P.; Traullé, O.; Tzanos, D.; Wacker, S.; Wildmann, N.; Zaldei, A.

    2014-10-01

    Due to the major role of the sun in heating the earth's surface, the atmospheric planetary boundary layer over land is inherently marked by a diurnal cycle. The afternoon transition, the period of the day that connects the daytime dry convective boundary layer to the night-time stable boundary layer, still has a number of unanswered scientific questions. This phase of the diurnal cycle is challenging from both modelling and observational perspectives: it is transitory, most of the forcings are small or null and the turbulence regime changes from fully convective, close to homogeneous and isotropic, toward a more heterogeneous and intermittent state. These issues motivated the BLLAST (Boundary-Layer Late Afternoon and Sunset Turbulence) field campaign that was conducted from 14 June to 8 July 2011 in southern France, in an area of complex and heterogeneous terrain. A wide range of instrumented platforms including full-size aircraft, remotely piloted aircraft systems, remote-sensing instruments, radiosoundings, tethered balloons, surface flux stations and various meteorological towers were deployed over different surface types. The boundary layer, from the earth's surface to the free troposphere, was probed during the entire day, with a focus and intense observation periods that were conducted from midday until sunset. The BLLAST field campaign also provided an opportunity to test innovative measurement systems, such as new miniaturized sensors, and a new technique for frequent radiosoundings of the low troposphere. Twelve fair weather days displaying various meteorological conditions were extensively documented during the field experiment. The boundary-layer growth varied from one day to another depending on many contributions including stability, advection, subsidence, the state of the previous day's residual layer, as well as local, meso- or synoptic scale conditions. Ground-based measurements combined with tethered-balloon and airborne observations captured the

  19. Experimental determination of radiated internal wave power without pressure field data

    Science.gov (United States)

    Lee, Frank M.; Paoletti, M. S.; Swinney, Harry L.; Morrison, P. J.

    2014-04-01

    We present a method to determine, using only velocity field data, the time-averaged energy flux left and total radiated power P for two-dimensional internal gravity waves. Both left and P are determined from expressions involving only a scalar function, the stream function ψ. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data.

  20. Experimental determination of radiated internal wave power without pressure field data

    International Nuclear Information System (INIS)

    Lee, Frank M.; Morrison, P. J.; Paoletti, M. S.; Swinney, Harry L.

    2014-01-01

    We present a method to determine, using only velocity field data, the time-averaged energy flux (J) and total radiated power P for two-dimensional internal gravity waves. Both (J) and P are determined from expressions involving only a scalar function, the stream function ψ. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data

  1. Hidden Benefits of Reward : A Field Experiment on Motivation and Monetary Incentives

    OpenAIRE

    Kvaløy, Ola; Nieken, Petra; Schöttner, Anja

    2013-01-01

    We conducted a field experiment in a controlled work environment to investigate the effect of motivational talk and its interaction with monetary incentives. We find that motivational talk significantly improves performance only when accompanied by performance pay. Moreover, performance pay slightly reduces performance unless it is accompanied by motivational talk. These effects also carry over to the quality of work. Performance pay alone leads to more mistakes. Adding motivational talk make...

  2. Ultrafast electron field emission from gold resonant antennas studied by two terahertz pulse experiments

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Zalkovskij, Maksim; Strikwerda, Andrew C.

    2015-01-01

    Summary form only given. Ultrafast electron field emission from gold resonant antennas induced by strong terahertz (THz) transient is investigated using two THz pulse experiments. It is shown that UV emission from nitrogen plasma generated by liberated electrons is a good indication of the local...

  3. The influence of ego depletion on sprint start performance in athletes without track and field experience.

    Science.gov (United States)

    Englert, Chris; Persaud, Brittany N; Oudejans, Raôul R D; Bertrams, Alex

    2015-01-01

    We tested the assumption that ego depletion would affect the sprint start in a sample of N = 38 athletes without track and field experience in an experiment by applying a mixed between- (depletion vs. non-depletion) within- (T1: before manipulation of ego depletion vs. T2: after manipulation of ego depletion) subjects design. We assumed that ego depletion would increase the possibility for a false start, as regulating the impulse to initiate the sprinting movement too soon before the starting signal requires self-control. In line with our assumption, we found a significant interaction as there was only a significant increase in the number of false starts from T1 to T2 for the depletion group while this was not the case for the non-depletion group. We conclude that ego depletion has a detrimental influence on the sprint start in athletes without track and field experience.

  4. About the Toroidal Magnetic Field of a Tokamak Burning Plasma Experiment with Superconducting Coils

    International Nuclear Information System (INIS)

    Mazzucato, E.

    2002-01-01

    In tokamaks, the strong dependence on the toroidal magnetic field of both plasma pressure and energy confinement is what makes possible the construction of small and relatively inexpensive burning plasma experiments using high-field resistive coils. On the other hand, the toroidal magnetic field of tokamaks using superconducting coils is limited by the critical field of superconductivity. In this article, we examine the relative merit of raising the magnetic field of a tokamak plasma by increasing its aspect ratio at a constant value of the peak field in the toroidal magnet. Taking ITER-FEAT as an example, we find that it is possible to reach thermonuclear ignition using an aspect ratio of approximately 4.5 and a toroidal magnetic field of 7.3 T. Under these conditions, fusion power density and neutron wall loading are the same as in ITER [International Thermonuclear Experimental Reactor], but the normalized plasma beta is substantially smaller. Furthermore, such a tokamak would be able to reach an energy gain of approximately 15 even with the deterioration in plasma confinement that is known to occur near the density limit where ITER is forced to operate

  5. Testing of Photomultiplier Tubes in a Magnetic Field

    Science.gov (United States)

    Waldron, Zachary; A1 Collaboration

    2016-09-01

    The A1 collaboration at MAMI in Mainz, Germany has designed a neutron detector that can be used in experiments to measure the electric form factor of the neutron. They will measure elastic scattering from the neutron, using the polarized electron beam from MAMI at A1's experimental hall. The detector will be composed of two walls of staggered scintillator bars which will be read out by photomultiplier tubes (PMT), connected to both ends of each scintillator via light guides. The experiment requires a magnetic field with strength of 1 Tesla, 2m away from the first scintillator wall. The resulting fringe field is sufficient to disrupt the PMTs, despite the addition of Mu Metal shielding. The effects of the fringe field on these PMTs was tested to optimize the amplification of the PMTs. A Helmholtz Coil was designed to generate a controlled magnetic field with equivalent strength to the field that the PMTs will encounter. The PMTs were read out using a multi-channel analyzer, were tested at various angles relative to the magnetic field in order to determine the optimal orientation to minimize signal disruption. Tests were also performed to determine: the neutron detector response to cosmic radiation; and the best method for measuring a magnetic field's strength in two dimensions. National Science Foundation Grant No. IIA-1358175.

  6. Determination of the Young modulus relaxation of high orders from dynamic experiments on crystals

    International Nuclear Information System (INIS)

    Topchyan, I.I.; Dokhner, R.D.

    1977-01-01

    A theoretical investigation into the inelastic behaviour of a crystal under the effect of a periodic load was carried out. Both the dimentional and module effects in the interaction of anisotropic point effects with the applied-stress fields and also the anharmonism of the interatomic interaction forces were taken into account. In this case the crystal deformation can be presented as a superposition of higher-order harmonics with a frequency multiple of that of the field applied. It is shown that the phase shift in the first harmonic determines the usually measured internal friction and depends exclusively on the dimentional effect in the interaction of defects with elastic-stress fields. The phase shift in the higher-order harmonics is due both to dimentional and module effects and it is possible, by measuring shift, to determine the ratios between the elastic modules of a defect

  7. Electric field strength determination in filamentary DBDs by CARS-based four-wave mixing

    Science.gov (United States)

    Boehm, Patrick; Kettlitz, Manfred; Brandenburg, Ronny; Hoeft, Hans; Czarnetzki, Uwe

    2016-09-01

    The electric field strength is a basic parameter of non-thermal plasmas. Therefore, a profound knowledge of the electric field distribution is crucial. In this contribution a four wave mixing technique based on Coherent Anti-Stokes Raman spectroscopy (CARS) is used to measure electric field strengths in filamentary dielectric barrier discharges (DBDs). The discharges are operated with a pulsed voltage in nitrogen at atmospheric pressure. Small amounts hydrogen (10 vol%) are admixed as tracer gas to evaluate the electric field strength in the 1 mm discharge gap. Absolute values of the electric field strength are determined by calibration of the CARS setup with high voltage amplitudes below the ignition threshold of the arrangement. Alteration of the electric field strength has been observed during the internal polarity reversal and the breakdown process. In this case the major advantage over emission based methods is that this technique can be used independently from emission, e.g. in the pre-phase and in between two consecutive, opposite discharge pulses where no emission occurs at all. This work was supported by the Deutsche Forschungsgemeinschaft, Forschergruppe FOR 1123 and Sonderforschungsbereich TRR 24 ``Fundamentals of complex plasmas''.

  8. Rocket to Creativity: A Field Experience in Problem-Based and Project-Based Learning

    Science.gov (United States)

    Dole, Sharon F.; Bloom, Lisa A.; Doss, Kristy Kowalske

    2016-01-01

    This article reports the impact of a field experience in problem-based (PBL) and project-based learning (PjBL) on in-service teachers' conceptions of experiential learning. Participants had been enrolled in a hybrid class that included an online component in which they learned about PBL and PjBL, and an experiential component in which they…

  9. Catheter visualisation in MR tomography: first animal experimental experiences with field inhomogeneity catheters

    International Nuclear Information System (INIS)

    Adam, G.; Glowinski, A.; Neuerburg, J.; Buecker, A.; Vaals, J.J. van; Hurtak, W.; Guenther, R.W.

    1997-01-01

    Purpose: To assess the feasibility of a new developed field inhomogeneity catheter for interventional MR imaging in vivo. Materials and methods: Three different prototypes of a field inhomogeneity catheter were investigated in 6 pigs. The catheters were introduced in Seldinger technique via the femoral vessels over a guide wire on an interventional MR system (Philips Gyroscan NT combined with a C-arm fluoroscopy unit [Philips BV 212[). Catheters were placed in veins and arteries. The catheter position was controlled by a fast gradient echo sequence (Turbo Field Echo [TEF[). Results: Catheters were introduced over a guide wire without complications in all cases. Using the field inhomogeneity concept, catheters were easily visualised in the inferior vena cava and the aorta by the fast gradient echo technique on MR in all cases. Although aortic branches were successfully cannulated, the catheters were not displayed by the TFE technique due to the complex and tortuous anatomy. All animals survived the experiments without complications. Conclusion: MR guided visualisation of a field inhomogeneity catheter is a simple concept which can be realised on each MR scanner and may allow intravascular MR guided interventions in future. (orig.) [de

  10. CREST-Snow Field Experiment: analysis of snowpack properties using multi-frequency microwave remote sensing data

    Directory of Open Access Journals (Sweden)

    T. Y. Lakhankar

    2013-02-01

    Full Text Available The CREST-Snow Analysis and Field Experiment (CREST-SAFE was carried out during January–March 2011 at the research site of the National Weather Service office, Caribou, ME, USA. In this experiment dual-polarized microwave (37 and 89 GHz observations were accompanied by detailed synchronous observations of meteorology and snowpack physical properties. The objective of this long-term field experiment was to improve understanding of the effect of changing snow characteristics (grain size, density, temperature under various meteorological conditions on the microwave emission of snow and hence to improve retrievals of snow cover properties from satellite observations. In this paper we present an overview of the field experiment and comparative preliminary analysis of the continuous microwave and snowpack observations and simulations. The observations revealed a large difference between the brightness temperature of fresh and aged snowpack even when the snow depth was the same. This is indicative of a substantial impact of evolution of snowpack properties such as snow grain size, density and wetness on microwave observations. In the early spring we frequently observed a large diurnal variation in the 37 and 89 GHz brightness temperature with small depolarization corresponding to daytime snowmelt and nighttime refreeze events. SNTHERM (SNow THERmal Model and the HUT (Helsinki University of Technology snow emission model were used to simulate snowpack properties and microwave brightness temperatures, respectively. Simulated snow depth and snowpack temperature using SNTHERM were compared to in situ observations. Similarly, simulated microwave brightness temperatures using the HUT model were compared with the observed brightness temperatures under different snow conditions to identify different states of the snowpack that developed during the winter season.

  11. Application of slope-intercept diagram to determine the parameters of the nanocomposite field emitters in-situ

    International Nuclear Information System (INIS)

    Smirnov, I U; Kolosko, A G; Filippov, S V; Yudkina, N A; Popov, E O

    2016-01-01

    The method of the field emission data online processing of materials, perspective for a nanoelectronics, is developed. The method is based on the slope-intercept diagram analysis of the current voltage characteristics registered during the experiment. It allows to build calibration grids of the microscopic emission parameters, such as work function, effective emission area and field enhancement factor, and and to estimate changes in the sample structure online. (paper)

  12. New indoor environment chambers and field experiment offices for research on human comfort, health and productivity

    DEFF Research Database (Denmark)

    Toftum, Jørn; Langkilde, Gunnar; Fanger, Povl Ole

    2004-01-01

    The article describes three new indoor environment chambers, a new laboratory for the study of air movement in spaces and five offices for controlled environment exposures of human subjects in field experiments at the International Centre for Indoor Environment and Energy, Technical University of...... of Denmark. Together with three older chambers, the Centre now has at its disposal 12 spaces for studying indoor environments and their impact on human comfort, health and productivity.......The article describes three new indoor environment chambers, a new laboratory for the study of air movement in spaces and five offices for controlled environment exposures of human subjects in field experiments at the International Centre for Indoor Environment and Energy, Technical University...

  13. Field experience with KWU SG chemical cleaning process

    International Nuclear Information System (INIS)

    Odar, S.

    1989-01-01

    The ingress of corrosion products into PWR steam generators (SG's) their deposition and the subsequent concentration of salt impurities can induce a variety of mechanisms for corrosion attack on SG tubing. Already, some plants have had to replace their steam generators due to severe corrosion damage and others are seriously considering the same costly action in the near future. One of the most effective ways to counteract corrosion mechanisms and thus to reduce the likelihood of SG replacement becoming necessary is to clean the SG's and to keep them clean. For many years, the industry has been involved in developing different types of cleaning techniques. Among these, chemical cleaning has been shown to be especially effective. In this article, the KWU chemical cleaning process, for which there is considerable application experience, is described. The results of field applications will be presented together with material compatibility data and information on cleaning effectiveness. (author)

  14. In pursuit of a science of agriculture: the role of statistics in field experiments.

    Science.gov (United States)

    Parolini, Giuditta

    2015-09-01

    Since the beginning of the twentieth century statistics has reshaped the experimental cultures of agricultural research taking part in the subtle dialectic between the epistemic and the material that is proper to experimental systems. This transformation has become especially relevant in field trials and the paper will examine the British agricultural institution, Rothamsted Experimental Station, where statistical methods nowadays popular in the planning and analysis of field experiments were developed in the 1920s. At Rothamsted statistics promoted randomisation over systematic arrangements, factorisation over one-question trials, and emphasised the importance of the experimental error in assessing field trials. These changes in methodology transformed also the material culture of agricultural science, and a new body, the Field Plots Committee, was created to manage the field research of the agricultural institution. Although successful, the vision of field experimentation proposed by the Rothamsted statisticians was not unproblematic. Experimental scientists closely linked to the farming community questioned it in favour of a field research that could be more easily understood by farmers. The clash between the two agendas reveals how the role attributed to statistics in field experimentation defined different pursuits of agricultural research, alternately conceived of as a scientists' science or as a farmers' science.

  15. Plasma parameters, fluctuations and kinetics in a magnetic field line reconnection experiment

    International Nuclear Information System (INIS)

    Wild, N.C. Jr.

    1983-01-01

    The processes associated with reconnecting magnetic field lines have been studied in a large experimental laboratory plasma. Detailed time- and space-resolved probe measurements of the plasma density, temperature, potential and electric and magnetic fields are discussed. Plasma currents are seen to modify the vacuum magnetic field topology. A flat neutral sheet develops along the separatrix where magnetic flux is transferred from regions of private to common flux. Forced tearing and magnetic island formation are also observed. Rapid electron heating, density and temperature nonuniformities and plasma potential gradients are all observed. The pressure is found to peak at the two edges of the neutral sheet. The dissipation E.J is determined and analyzed in terms of particle heating and fluid acceleration. A consistent, detailed picture of the energy flow via Poynting's theorem is also described. Significant temporal fluctuations in the magnetic fields and electron velocity distribution are measured and seen to give rise to anomalously high values for the plasma resistivity, the ion viscosity and the cross-field thermal conductivity. Electron temperature fluctuations, double layers associated with partial current disruptions, and whistler wave magnetic turbulence have all been identified and studied during the course of the reconnection event

  16. Variably Saturated Flow and Multicomponent Biogeochemical Reactive Transport Modeling of a Uranium Bioremediation Field Experiment

    International Nuclear Information System (INIS)

    Yabusaki, Steven B.; Fang, Yilin; Williams, Kenneth H.; Murray, Christopher J.; Ward, Anderson L.; Dayvault, Richard; Waichler, Scott R.; Newcomer, Darrell R.; Spane, Frank A.; Long, Philip E.

    2011-01-01

    Field experiments at a former uranium mill tailings site have identified the potential for stimulating indigenous bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. This effectively removes uranium from solution resulting in groundwater concentrations below actionable standards. Three-dimensional, coupled variably-saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport rates and biogeochemical reaction rates that determine the location and magnitude of key reaction products. A comprehensive reaction network, developed largely through previous 1-D modeling studies, was used to simulate the impacts on uranium behavior of pulsed acetate amendment, seasonal water table variation, spatially-variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. A principal challenge is the mechanistic representation of biologically-mediated terminal electron acceptor process (TEAP) reactions whose products significantly alter geochemical controls on uranium mobility through increases in pH, alkalinity, exchangeable cations, and highly reactive reduction products. In general, these simulations of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado confirmed previously identified behaviors including (1) initial dominance by iron reducing bacteria that concomitantly reduce aqueous U(VI), (2) sulfate reducing bacteria that become dominant after ∼30 days and outcompete iron reducers for the acetate electron donor, (3) continuing iron-reducer activity and U(VI) bioreduction during dominantly sulfate reducing conditions, and (4) lower apparent U(VI) removal from groundwater during dominantly sulfate reducing conditions. New knowledge on simultaneously active metal and sulfate reducers has been

  17. Poloidal magnetic field profile measurements on the microwave tokamak experiment using far-infrared polarimetry

    International Nuclear Information System (INIS)

    Rice, B.W.

    1992-09-01

    The measurement of plasma poloidal magnetic field (B) profiles in tokamaks with good temporal and spatial resolution has proven to be a difficult but important measurement. A large range of toroidal confinement phenomena is expected to depend sensitively on the radial variation of B including the tearing instability, sawtooth oscillations, disruptions, and transport. Experimental confirmation of theoretical models describing these phenomena has been hampered by the lack of detailed B measurements. A fifteen chord far-infrared (FIR) polarimeter has been developed to measure B in the Microwave Tokamak, Experiment (MTX). Polarimetry utilizes the well known Faraday rotation effect, which causes a rotation of the polarization of an FIR beam propagating in the poloidal plane. The rotation angle is proportional to the component of B parallel to the beam. A new technique for determining the Faraday rotation angle is introduced, based on phase measurements of a rotating polarization ellipse. This instrument has been used successfully to measure B profiles for a wide range of experiments on MTX. For ohmic discharges, measurements of the safety factor on axis give q 0 ∼ 0.75 during sawteeth and q 0 > 1 without sawteeth. Large perturbations to the polarimeter signals correlated with the sawtooth crash are observed during some discharges. Measurements in discharges with electron cyclotron heating (ECH) show a transition from a hollow to peaked J profile that is triggered by the ECH pulse. Current-ramp experiments were done to perturb the J profile from the nominal Spitzer conductivity profile. Profiles for initial current ramps and ramps starting from a stable equilibrium have been measured and are compared with a cylindrical diffusion model. Finally, the tearing mode stability equation is solved using measured J profiles. Stability predictions are in good agreement with the existence of oscillations observed on the magnetic loops

  18. Quantifying differences in responses of aquatic insects to trace metal exposure in field studies and short-term stream mesocosm experiments

    Science.gov (United States)

    Iwasaki, Yuichi; Schmidt, Travis S.; Clements, William H.

    2018-01-01

    Characterizing macroinvertebrate taxa as either sensitive or tolerant is of critical importance for investigating impacts of anthropogenic stressors in aquatic ecosystems and for inferring causality. However, our understanding of relative sensitivity of aquatic insects to metals in the field and under controlled conditions in the laboratory or mesocosm experiments is limited. In this study, we compared the response of 16 lotic macroinvertebrate families to metals in short-term (10-day) stream mesocosm experiments and in a spatially extensive field study of 154 Colorado streams. Comparisons of field and mesocosm-derived EC20 (effect concentration of 20%) values showed that aquatic insects were generally more sensitive to metals in the field. Although the ranked sensitivity to metals was similar for many families, we observed large differences between field and mesocosm responses for some groups (e.g., Baetidae and Heptageniidae). These differences most likely resulted from the inability of short-term experiments to account for factors such as dietary exposure to metals, rapid recolonization in the field, and effects of metals on sensitive life stages. Understanding mechanisms responsible for differences among field, mesocosm, and laboratory approaches would improve our ability to predict contaminant effects and establish ecologically meaningful water-quality criteria.

  19. Determination of the propellant combustion law under ballistic experiment conditions

    Science.gov (United States)

    Ishchenko, A. N.; Diachkovskii, A. S.; Zykova, A. I.; Kasimov, VZ; Samorokova, N. M.

    2017-11-01

    The main characteristics of ballistic experiment are the maximum pressure in the combustion chamber P max and the projectile velocity at the time of barrel leaving U M. During the work the burning law of the new high-energy fuel was determined in a ballistic experiment. This burning law was used for a parametric study of depending P max and U M from a powder charge mass and a traveling charge at initial temperature of + 20 °C was carried out. The optimal conditions for loading were obtained for improving the muzzle velocity by 14.9 %. Under optimal loading, there is defined the conditions, which is possible to get the greatest value muzzle velocity projectile at pressures up to 600 MPa.

  20. Determination of Watershed Infiltration and Erosion Parameters from Field Rainfall Simulation Analyses

    Directory of Open Access Journals (Sweden)

    Mark E. Grismer

    2016-06-01

    Full Text Available Realistic modeling of infiltration, runoff and erosion processes from watersheds requires estimation of the effective hydraulic conductivity (Km of the hillslope soils and how it varies with soil tilth, depth and cover conditions. Field rainfall simulation (RS plot studies provide an opportunity to assess the surface soil hydraulic and erodibility conditions, but a standardized interpretation and comparison of results of this kind from a wide variety of test conditions has been difficult. Here, we develop solutions to the combined set of time-to-ponding/runoff and Green– Ampt infiltration equations to determine Km values from RS test plot results and compare them to the simpler calculation of steady rain minus runoff rates. Relating soil detachment rates to stream power, we also examine the determination of “erodibility” as the ratio thereof. Using data from over 400 RS plot studies across the Lake Tahoe Basin area that employ a wide range of rain rates across a range of soil slopes and conditions, we find that the Km values can be determined from the combined infiltration equation for ~80% of the plot data and that the laminar flow form of stream power best described a constant “erodibility” across a range of volcanic skirun soil conditions. Moreover, definition of stream power based on laminar flows obviates the need for assumption of an arbitrary Mannings “n” value and the restriction to mild slopes (<10%. The infiltration equation based Km values, though more variable, were on average equivalent to that determined from the simpler calculation of steady rain minus steady runoff rates from the RS plots. However, these Km values were much smaller than those determined from other field test methods. Finally, we compare RS plot results from use of different rainfall simulators in the basin and demonstrate that despite the varying configurations and rain intensities, similar erodibilities were determined across a range of

  1. Utilizing an Artificial Outcrop to Scaffold Learning Between Laboratory and Field Experiences in a College-Level Introductory Geology Course

    Science.gov (United States)

    Wilson, Meredith

    Geologic field trips are among the most beneficial learning experiences for students as they engage the topic of geology, but they are also difficult environments to maximize learning. This action research study explored one facet of the problems associated with teaching geology in the field by attempting to improve the transition of undergraduate students from a traditional laboratory setting to an authentic field environment. Utilizing an artificial outcrop, called the GeoScene, during an introductory college-level non-majors geology course, the transition was studied. The GeoScene was utilized in this study as an intermediary between laboratory and authentic field based experiences, allowing students to apply traditional laboratory learning in an outdoor environment. The GeoScene represented a faux field environment; outside, more complex and tangible than a laboratory, but also simplified geologically and located safely within the confines of an educational setting. This exploratory study employed a mixed-methods action research design. The action research design allowed for systematic inquiry by the teacher/researcher into how the students learned. The mixed-methods approach garnered several types of qualitative and quantitative data to explore phenomena and support conclusions. Several types of data were collected and analyzed, including: visual recordings of the intervention, interviews, analytic memos, student reflections, field practical exams, and a pre/post knowledge and skills survey, to determine whether the intervention affected student comprehension and interpretation of geologic phenomena in an authentic field environment, and if so, how. Students enrolled in two different sections of the same laboratory course, sharing a common lecture, participated in laboratory exercises implementing experiential learning and constructivist pedagogies that focused on learning the basic geological skills necessary for work in a field environment. These laboratory

  2. 7 CFR 1755.3 - Field trials.

    Science.gov (United States)

    2010-01-01

    ...; (5) Responsibility for testing, test equipment and normal operation and maintenance during the trial... Telephone Systems of RUS Borrowers,” RUS Bulletin 344-2. When new items of materials or equipment are... modifications that its suitability cannot be determined based on laboratory data and/or field experience, a...

  3. Pollination Requirements of Almond (Prunus dulcis): Combining Laboratory and Field Experiments.

    Science.gov (United States)

    Henselek, Yuki; Eilers, Elisabeth J; Kremen, Claire; Hendrix, Stephen D; Klein, Alexandra-Maria

    2018-03-08

    Almond (Prunus dulcis (Mill.) D. A. Webb; Rosales: Rosaceae) is a cash crop with an estimated global value of over seven billion U.S. dollars annually and commercial varieties are highly dependent on insect pollination. Therefore, the understanding of basic pollination requirements of the main varieties including pollination efficiency of honey bees (Apis mellifera, Linnaeus, Hymenoptera: Apidae) and wild pollinators is essential for almond production. We first conducted two lab experiments to examine the threshold number of pollen grains needed for successful pollination and to determine if varietal identity or diversity promotes fruit set and weight. Further, we examined stigma and ovules of flowers visited by Apis and non-Apis pollinators in the field to study the proportion of almond to non-almond pollen grains deposited, visitation time per flower visit, and tube set. Results indicate that the threshold for successful fertilization is around 60 pollen grains, but pollen can be from any compatible variety as neither pollen varietal identity nor diversity enhanced fruit set or weight. Andrena cerasifolii Cockerell (Hymenoptera: Andrenidae) was a more effective pollinator on a per single visit basis than Apis and syrphid flies. Nevertheless, Apis was more efficient than A. cerasifolii and syrphid flies as they spent less time on a flower during a single visit. Hence, planting with two compatible varieties and managing for both Apis and non-Apis pollinators is likely to be an optimal strategy for farmers to secure high and stable pollination success.

  4. Do Wage Cuts Damage Work Morale? Evidence from a Natural Field Experiment

    OpenAIRE

    Kube, Sebastian; Maréchal, Michel; Puppe, Clemens

    2011-01-01

    Employment contracts are often incomplete, leaving many responsibilities subject to workers� discretion. High work morale is therefore essential for sustaining voluntary cooperation and high productivity in firms. We conducted a field experiment to test whether workers reciprocate wage cuts and raises with low or high work productivity. Wage cuts had a detrimental and persistent impact on productivity, reducing average output by more than 20 percent. An equivalent wage increase, however, di...

  5. Understanding the Role of Critical Incidents in Relation to Self-Efficacy during Course-Embedded Preservice Teacher Field Experiences: A Qualitative Study

    Science.gov (United States)

    Epperly, Anna C.

    2017-01-01

    This qualitative, collective case study documented the development of the self-efficacy beliefs of special education preservice candidates during one semester of a course-embedded field experience in a small, private, faith-based university in the Midwest. Interviews of candidates regarding critical incidents in field experiences as documented by…

  6. Feeble magnetic fields generated by thermal charge fluctuations in extended metallic conductors: Implications for electric-dipole moment experiments

    International Nuclear Information System (INIS)

    Lamoreaux, S.K.

    1999-01-01

    A simple formulation for calculating the magnetic field external to an extended nonpermeable conducting body due to thermal current fluctuations within the body is developed, and is applied to a recent experimental search for the atomic electric-dipole moment (EDM) of 199 Hg. It is shown that the thermal fluctuation field is only slightly smaller in magnitude than other noise sources in that experiment. The formulation is extended to permeable bodies, and the implications for general EDM experiments are discussed. copyright 1999 The American Physical Society

  7. Determination of dose rates in beta radiation fields using extrapolation chamber and GM counter

    International Nuclear Information System (INIS)

    Borg, J.; Christensen, P.

    1995-01-01

    The extrapolation chamber measurement method is the basic method for the determination of dose rates in beta radiation fields and the method has been used for the establishment of beta calibration fields. The paper describes important details of the method and presents results from the measurements of depth-dose profiles from different beta radiation fields with E max values down to 156 keV. Results are also presented from studies of GM counters for use as survey instruments for monitoring beta dose rates at the workplace. Advantages of GM counters are a simple measurement technique and high sensitivity. GM responses were measured from exposures in different beta radiation fields using different filters in front of the GM detector and the paper discusses the possibility of using the results from GM measurements with two different filters in an unknown beta radiation field to obtain a value of the dose rate. (Author)

  8. Determination of trapping parameters and the chemical diffusion coefficient from hydrogen permeation experiments

    International Nuclear Information System (INIS)

    Svoboda, J.; Mori, G.; Prethaler, A.; Fischer, F.D.

    2014-01-01

    Highlights: • A modeling study for diffusion of hydrogen with traps is presented. • Introduction of a new chemical diffusion coefficient. • Density of traps and average depth of traps can be determined. • Lattice diffusion and sub-surface concentration of atomic hydrogen can be determined. - Abstract: An improved diffusion theory accounting for trapping effects is applied to evaluation of hydrogen permeation experiments performed for pure iron and pearlitic and martensitic steels. The trapping parameters as molar volume and depth of traps are determined by fitting experiments by simulations based on the theory. The concentration-dependent chemical diffusion coefficient of hydrogen is extracted indicating that the trapping effect on diffusion in pure iron and pearlitic steel is negligible. However, it is significant for martensitic steel, for which the chemical diffusion coefficient cannot be considered as concentration-independent as it is established in current standards

  9. Experiment and modeling of an atmospheric pressure arc in an applied oscillating magnetic field

    International Nuclear Information System (INIS)

    Karasik, Max; Roquemore, A. L.; Zweben, S. J.

    2000-01-01

    A set of experiments are carried out to measure and understand the response of a free-burning atmospheric pressure carbon arc to applied transverse dc and ac magnetic fields. The arc is found to deflect parabolically for the dc field and assumes a growing sinusoidal structure for the ac field. A simple analytic two-parameter fluid model of the arc dynamics is derived, in which the arc response is governed by the arc jet originating at the cathode, with the applied JxB force balanced by inertia. Time variation of the applied field allows evaluation of the parameters individually. A fit of the model to the experimental data gives a value for the average jet speed an order of magnitude below Maecker's estimate of the maximum jet speed [H. Maecker, Z. Phys. 141, 198 (1955)]. An example industrial application of the model is considered. (c) 2000 American Institute of Physics

  10. Electric fields in plasmas under pulsed currents

    International Nuclear Information System (INIS)

    Tsigutkin, K.; Doron, R.; Stambulchik, E.; Bernshtam, V.; Maron, Y.; Fruchtman, A.; Commisso, R. J.

    2007-01-01

    Electric fields in a plasma that conducts a high-current pulse are measured as a function of time and space. The experiment is performed using a coaxial configuration, in which a current rising to 160 kA in 100 ns is conducted through a plasma that prefills the region between two coaxial electrodes. The electric field is determined using laser spectroscopy and line-shape analysis. Plasma doping allows for three-dimensional spatially resolved measurements. The measured peak magnitude and propagation velocity of the electric field is found to match those of the Hall electric field, inferred from the magnetic-field front propagation measured previously

  11. Determining Thunderstorm Electric Fields using Radio Emission from Cosmic-Ray Air Showers

    Science.gov (United States)

    Hare, B.; Scholten, O.; Trinh, G. T. N.; Ebert, U.; Rutjes, C.

    2017-12-01

    We report on a novel non-intrusive way to investigate electric fields in thunderclouds.Energetic cosmic rays penetrating the atmosphere create a particle avalanche called an extensive air shower. The front of the shower is a plasma cloud that contains 10^6 or more free electrons and positrons moving towards the Earth's surface at the speed of light. The electric fields that exists in thunderclouds induces electric currents in the plasma cloud that emit radio waves. The radio footprint for intensity, linear and circular polarization thus contains the finger print of the atmospheric electric fields along the path of the air shower.Here we report on the analysis of many cosmic-ray radio footprints as have been measured at LOFAR, a dense array of simple radio antennas (several thousands of dual-polarized antennas) primarily developed for radio-astronomy observations. We show that this method can be used to determine the charge structure in thunderclouds and discuss the accuracy of the method. We have observed seasonal dependencies.

  12. Determination of Intrinsic Magnetic Response from Local Measurements of Fringing Fields

    OpenAIRE

    Wen, Bo; Millis, Andrew J.; Pardo, Enric; Subedi, Pradeep; Kent, Andrew D.; Yeshurun, Yosi; Sarachik, Myriam P.

    2014-01-01

    Micron-sized Hall bars and micro-SQUIDs are now used routinely to measure the local static and dynamic magnetic response with micron-scale spatial resolution. While this provides a powerful new tool, determining the intrinsic magnetization presents new challenges, as it requires correcting for demagnetization fields that vary widely with position on a sample. In this paper we develop a method to correct for the demagnetization effect at local points of a rectangular prism shaped sample using ...

  13. Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak complex magnetic fields.

    Science.gov (United States)

    Granqvist, Pehr; Fredrikson, Mats; Unge, Patrik; Hagenfeldt, Andrea; Valind, Sven; Larhammar, Dan; Larsson, Marcus

    2005-04-29

    Transcranial magnetic stimulation (TMS) with weak (micro Tesla) complex waveform fields have been claimed to evoke the sensed presence of a sentient being in up to 80% in the general population. These findings have had a questionable neurophysiological foundation as the fields are approximately six orders of magnitude weaker than ordinary TMS fields. Also, no independent replication has been reported. To replicate and extend previous findings, we performed a double-blind experiment (N=89), with a sham-field control group. Personality characteristics indicating suggestibility (absorption, signs of abnormal temporal lobe activity, and a "new age"-lifestyle orientation) were used as predictors. Sensed presence, mystical, and other somatosensory experiences previously reported from the magnetic field stimulation were outcome measures. We found no evidence for any effects of the magnetic fields, neither in the entire group, nor in individuals high in suggestibility. Because the personality characteristics significantly predicted outcomes, suggestibility may account for previously reported effects. Our results strongly question the earlier claims of experiential effects of weak magnetic fields.

  14. Structural determination of organic compounds

    International Nuclear Information System (INIS)

    Kintzinger, J.P.

    1991-01-01

    This paper reports that the current methods available in high-field NMR spectroscopy are such that the tridimensional structure determination of any rigid molecule containing only carbon and hydrogen atoms may be achieved. The connectivities between carbon-carbon, carbon-hydrogen, and hydrogen-hydrogen atoms are determined by multipulse and two-dimensional (2D) experiments. These connectivity patterns or maps allow a step-by-step reconstruction of the molecular structures. From the carbon-carbon connectivity map, the carbon framework of the molecule is obtained, whereas the carbon-hydrogen pattern allows determination of the positions of the hydrogen atoms on their corresponding carbon atoms. High-field spectrometers are then necessary to remove fortuitous degeneracy and to reduce the proton spectra to a nearly first-order one, allowing an easy measurement of the chemical shifts and the coupling constants

  15. Experiences of using mobile technologies and virtual field tours in Physical Geography: implications for hydrology education

    Directory of Open Access Journals (Sweden)

    D. G. Kingston

    2012-05-01

    Full Text Available Education in hydrology is changing rapidly due to diversification of students, emergent major scientific and practical challenges that our discipline must engage with, shifting pedagogic ideas and higher education environments, the need for students to develop new discipline specific and transferrable skills, and the advent of innovative technologies for learning and teaching. This paper focuses on new technologies in the context of learning and teaching in Physical Geography and reflects on the implications of our experiences for education in hydrology. We evaluate the experience of designing and trialling novel mobile technology-based field exercises and a virtual field tour for a Year 1 undergraduate Physical Geography module at a UK university. The new exercises are based on using and obtaining spatial data, operation of meteorological equipment (explained using an interactive DVD, and include introductions to global positioning systems (GPS and geographical information systems (GIS. The technology and exercises were well received in a pilot study and subsequent rolling-out to the full student cohort (∼150 students. A statistically significant improvement in marks was observed following the redesign. Although the students enjoyed using mobile technology, the increased interactivity and opportunity for peer learning were considered to be the primary benefits by students. This is reinforced further by student preference for the new interactive virtual field tour over the previous "show-and-tell" field exercise. Despite the new exercises having many advantages, exercise development was not trivial due to the high start-up costs, the need for provision of sufficient technical support and the relative difficulty of making year-to-year changes (to the virtual field tour in particular. Our experiences are highly relevant to the implementation of novel learning and teaching technologies in hydrology education.

  16. Experiences of using mobile technologies and virtual field tours in Physical Geography: implications for hydrology education

    Science.gov (United States)

    Kingston, D. G.; Eastwood, W. J.; Jones, P. I.; Johnson, R.; Marshall, S.; Hannah, D. M.

    2012-05-01

    Education in hydrology is changing rapidly due to diversification of students, emergent major scientific and practical challenges that our discipline must engage with, shifting pedagogic ideas and higher education environments, the need for students to develop new discipline specific and transferrable skills, and the advent of innovative technologies for learning and teaching. This paper focuses on new technologies in the context of learning and teaching in Physical Geography and reflects on the implications of our experiences for education in hydrology. We evaluate the experience of designing and trialling novel mobile technology-based field exercises and a virtual field tour for a Year 1 undergraduate Physical Geography module at a UK university. The new exercises are based on using and obtaining spatial data, operation of meteorological equipment (explained using an interactive DVD), and include introductions to global positioning systems (GPS) and geographical information systems (GIS). The technology and exercises were well received in a pilot study and subsequent rolling-out to the full student cohort (∼150 students). A statistically significant improvement in marks was observed following the redesign. Although the students enjoyed using mobile technology, the increased interactivity and opportunity for peer learning were considered to be the primary benefits by students. This is reinforced further by student preference for the new interactive virtual field tour over the previous "show-and-tell" field exercise. Despite the new exercises having many advantages, exercise development was not trivial due to the high start-up costs, the need for provision of sufficient technical support and the relative difficulty of making year-to-year changes (to the virtual field tour in particular). Our experiences are highly relevant to the implementation of novel learning and teaching technologies in hydrology education.

  17. Neutron spectrum determination by activation method in fast neutron fields at the RB reactor

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.; Pesic, M.; Antic, D.

    1994-01-01

    The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (author)

  18. Determinants of caregiving experiences and mental health of partners of cancer patients

    NARCIS (Netherlands)

    Nijboer, C; Triemstra, M; Sanderman, R; van den Bos, GAM

    1999-01-01

    BACKGROUND. Research regarding informal caregiving showed considerable individual variation in responses to cancer caregiving. The current longitudinal study examined determinants of caregiver outcomes in terms of caregiver experiences at 3 months and caregiver's mental health at 6 months after

  19. Determinants of caregiving experiences and mental health of partners of cancer patients

    NARCIS (Netherlands)

    Nijboer, C.; Triemstra, M.; Tempelaar, R.; Sanderman, R.; van den Bos, G. A.

    1999-01-01

    Research regarding informal caregiving showed considerable individual variation in responses to cancer caregiving. The current longitudinal study examined determinants of caregiver outcomes in terms of caregiver experiences at 3 months and caregiver's mental health at 6 months after hospital

  20. Probing a quantum field in a photon box

    International Nuclear Information System (INIS)

    Raimond, J M; Meunier, T; Bertet, P; Gleyzes, S; Maioli, P; Auffeves, A; Nogues, G; Brune, M; Haroche, S

    2005-01-01

    Einstein often performed thought experiments with 'photon boxes', storing fields for unlimited times. This is yet but a dream. We can nevertheless store quantum microwave fields in superconducting cavities for billions of periods. Using circular Rydberg atoms, it is possible to probe in a very detailed way the quantum state of these trapped fields. Cavity quantum electrodynamics tools can be used for a direct determination of the Husimi Q and Wigner quasi-probability distributions. They provide a very direct insight into the classical or non-classical nature of the field

  1. Transport Task Force workshop: basic experiments highlights

    Energy Technology Data Exchange (ETDEWEB)

    Linford, R.K. (Los Alamos National Lab., NM (USA)); Luckhardt, S. (Massachusetts Inst. of Tech., Cambridge, MA (USA)); Lyon, J.F. (Oak Ridge National Lab., TN (USA)); Navratil, G.A. (Columbia Univ., New York, NY (USA)); Schoenberg, K.F. (Los Alamos National Lab., NM (USA))

    1990-01-01

    Selected topics are summarized from the Basic Experiments session of the Transport Task Force Workshop held August 21-24, 1989, in San Diego, California. This session included presentations on paradigm experiments, stellarators, reversed-field pinches, and advanced tokamaks. Recent advances in all of these areas illustrate the importance of these experiments in advancing our understanding of toroidal transport. Progress has been made in measuring the details of particle diffusion, isolating specific modes, measuring fluctuation variations with field geometry and beta, and comparing all these with theoretical predictions. The development of experimental tools for determining which fluctuations dominate transport are also reported. Continued significant advances are anticipated in a number of areas highlighted. (author).

  2. Transport Task Force workshop: basic experiments highlights

    International Nuclear Information System (INIS)

    Linford, R.K.; Luckhardt, S.; Lyon, J.F.; Navratil, G.A.; Schoenberg, K.F.

    1990-01-01

    Selected topics are summarized from the Basic Experiments session of the Transport Task Force Workshop held August 21-24, 1989, in San Diego, California. This session included presentations on paradigm experiments, stellarators, reversed-field pinches, and advanced tokamaks. Recent advances in all of these areas illustrate the importance of these experiments in advancing our understanding of toroidal transport. Progress has been made in measuring the details of particle diffusion, isolating specific modes, measuring fluctuation variations with field geometry and beta, and comparing all these with theoretical predictions. The development of experimental tools for determining which fluctuations dominate transport are also reported. Continued significant advances are anticipated in a number of areas highlighted. (author)

  3. PAC Experiments at ISOLDE

    CERN Multimedia

    2002-01-01

    The study of hyperfine interactions offers the possibility to use radioactive nuclei as probes in matter. The @g-@g perturbated angular correlation (PAC) technique following implantation has found widespread application in this field. At ISOLDE we have been investigating electric field gradients at impurities in non-cubic metals in an ongoing series of experiments. \\\\ \\\\ The small number of probe atoms necessary for these measurements make them also ideally suited for studies of surface problems like diffusion, structure and dynamics. Cd on a molybdenum O110? surface will be studied as first system. For this purpose 10|1|0~atoms of |1|1|1|mCd will be evaporated onto the clean surface and the electric field gradient for isolated adatoms on terrace sites will be determined by PAC. The UHV system constructed for such experiments at ISOLDE is shown in the schematic drawing. It is coupled to the beam line through differential pumping stations and contains standard surface treatment and analysis equipment.

  4. FLORIDA TOWER FOOTPRINT EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    WATSON,T.B.; DIETZ, R.N.; WILKE, R.; HENDREY, G.; LEWIN, K.; NAGY, J.; LECLERC, M.

    2007-01-01

    The Florida Footprint experiments were a series of field programs in which perfluorocarbon tracers were released in different configurations centered on a flux tower to generate a data set that can be used to test transport and dispersion models. These models are used to determine the sources of the CO{sub 2} that cause the fluxes measured at eddy covariance towers. Experiments were conducted in a managed slash pine forest, 10 km northeast of Gainesville, Florida, in 2002, 2004, and 2006 and in atmospheric conditions that ranged from well mixed, to very stable, including the transition period between convective conditions at midday to stable conditions after sun set. There were a total of 15 experiments. The characteristics of the PFTs, details of sampling and analysis methods, quality control measures, and analytical statistics including confidence limits are presented. Details of the field programs including tracer release rates, tracer source configurations, and configuration of the samplers are discussed. The result of this experiment is a high quality, well documented tracer and meteorological data set that can be used to improve and validate canopy dispersion models.

  5. Using Norm-Based Appeals to Increase Response Rates in Evaluation Research: A Field Experiment

    Science.gov (United States)

    Misra, Shalini; Stokols, Daniel; Marino, Anne Heberger

    2012-01-01

    A field experiment was conducted to test the effectiveness of norm-based persuasive messages for increasing response rates in online survey research. Participants in an interdisciplinary conference were asked to complete two successive postconference surveys and randomly assigned to one of two groups at each time point. The experimental group…

  6. The role of status and leadership style in sales contests: A natural field experiment

    NARCIS (Netherlands)

    Verbeke, W.; Bagozzi, R.P.; Belschak, F.D.

    2016-01-01

    This paper addresses the question whether status alone, as compared to a combined financial/status incentive, is strong enough to motivate team members taking part in a retail sales contest to sell more goods to customers. Using a two-phase natural field experiment, we studied the impact of a sales

  7. Earthworms influenced by reduced tillage, conventional tillage and energy forest in Swedish agricultural field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagerloef, Jan (SLU, Department of Ecology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), Email: Jan.Lagerlof@ekol.slu.se; Paalsson, Olof; Arvidsson, Johan (SLU, Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    2012-03-15

    We compared earthworm density, depth distribution and species composition in three soil cultivation experiments including the treatments ploughless tillage and mouldboard ploughing. Sampling was done in September 2005 and for one experiment also in 1994. By yearly sampling 1995-2005, earthworms in an energy forest of Salix viminalis were compared with those in an adjacent arable field. Sampling method was digging of soil blocks and hand sorting and formalin sampling in one cultivation experiment. Both methods were used in the energy forest and arable land comparison. In two soil cultivation experiments, highest abundances or biomass were found in ploughless tillage. Earthworm density was higher in the upper 10 cm, especially in the ploughless tillage. Earthworm density was significantly higher in the energy forest than in the arable field. Formalin sampling revealed c. 36% of the earthworm numbers found by digging in the energy forest and gave almost no earthworms in the arable field. In all treatments with soil cultivation, species living and feeding in the rhizosphere and soil dominated. One such species, Allolobophora chlorotica, was more abundant under mouldboard ploughing than ploughless tillage. Lumbricus terrestris, browsing on the surface and producing deep vertical burrows, was more common in the ploughless tillage. Species living and feeding close to the soil surface were almost only found in the energy forest, which had not been soil cultivated since 1984. The findings support earlier studies pointing out possibilities to encourage earthworms by reduced soil cultivation. This is one of the first published studies that followed earthworm populations in an energy forest plantation during several years. Explanation of earthworm reactions to management and environmental impacts should be done with consideration of the ecology of species or species groups. Earthworm sampling by formalin must always be interpreted with caution and calibrated by digging and

  8. Do Schools Discriminate Against Homosexual Parents? Evidence from an Internet Field Experiment

    OpenAIRE

    Diaz-Serrano, Luis; Meix-Llop, Enric

    2015-01-01

    The recognition of homosexual rights is a controversial issue in many countries. Spain was the third country in the world (after Netherlands and Belgium) to introduce a law recognizing homosexual marriage and adoption of children. In this paper, we examine for the first time whether schools are more hesitant to give feedback to homosexual parents during children's pre-registration period in Spain. In order to do that, we designed an internet field experiment to be conducted in ...

  9. DO SELF-THEORIES EXPLAIN OVERCONFIDENCE AND FINANCIAL RISK TAKING? A field experiment.

    OpenAIRE

    Bertrand Koebel; André Schmitt; Sandrine Spaeter

    2015-01-01

    How people develop beliefs about themselves (self-theories) plays an important role on motivation and achievement as shown by Carol Dweck’s life-long research. In this paper, we conduct a field experiment to investigate whether self-theories impact overconfidence and risk taking. Self-theories deal with how an individual perceives some of her attributes such as intelligence, personality or moral character. In this paper, we are interested by how people perceive their mindset (fixed or growth)...

  10. Earth Science Project Office (ESPO) Field Experiences During ORACLES, ATom, KORUS and POSIDON

    Science.gov (United States)

    Salazar, Vidal; Zavaleta, Jhony

    2017-01-01

    Very often, scientific field campaigns entail years of planning and incur substantial cost, especially if they involve the operation of large research aircraft in remote locations. Deploying and operating these aircrafts even for short periods of time poses challenges that, if not addressed properly, can have significant negative consequences and potentially jeopardize the success of a scientific campaign. Challenges vary from country to country and range from safety, health, and security risks to differences in cultural and social norms. Our presentation will focus on sharing experiences on the ESPO 2016 conducted field campaigns ORACLES, ATom, KORUS and POSIDON. We will focus on the best practices, lessons learned, international relations and coordination aspects of the country-specific experiences. This presentation will be part of the ICARE Conference (2nd International Conference on Airborne Research for the Environment (ICARE 2017) that will focus on "Developing the infrastructure to meet future scientific challenges". This unique conference and gathering of facility support experts will not only allow for dissemination and sharing of knowledge but also promote collaboration and networking among groups that support scientific research using airborne platforms around the globe.

  11. Materials science experiments in space

    Science.gov (United States)

    Gelles, S. H.; Giessen, B. C.; Glicksman, M. E.; Margrave, J. L.; Markovitz, H.; Nowick, A. S.; Verhoeven, J. D.; Witt, A. F.

    1978-01-01

    The criteria for the selection of the experimental areas and individual experiments were that the experiment or area must make a meaningful contribution to the field of material science and that the space environment was either an absolute requirement for the successful execution of the experiment or that the experiment can be more economically or more conveniently performed in space. A number of experimental areas and individual experiments were recommended for further consideration as space experiments. Areas not considered to be fruitful and others needing additional analysis in order to determine their suitability for conduct in space are also listed. Recommendations were made concerning the manner in which these materials science experiments are carried out and the related studies that should be pursued.

  12. Explosive performance on the non-proliferation experiment

    Energy Technology Data Exchange (ETDEWEB)

    McKown, T.O.

    1994-03-01

    The non-proliferation experiment, originally called the chemical kiloton experiment, was planned and executed by Lawrence Livermore National Laboratory to investigate the seismic yield relationship and distinguishing seismic signals between a nuclear event and a large mass conventional explosion. The Los Alamos National Laboratory planned and conducted experiments to further their studies of the source function for signals observed seismically. Since all investigations were contingent on the performance of the emplaced chemical explosive, an array of diagnostic measurements was fielded in the emplaced explosive. The CORRTEX system was used to investigate the explosive initiation and to determine the detonation velocities in multiple levels and in numerous directions. A description of the CORRTEX experiments fielded, a review of the data obtained and some interpretations of the data are reported.

  13. Designing and Using Virtual Field Environments to Enhance and Extend Field Experience in Professional Development Programs in Geology for K-12 Teachers

    Science.gov (United States)

    Granshaw, Frank Douglas

    2011-01-01

    Virtual reality (VR) is increasingly used to acquaint geoscience novices with some of the observation, data gathering, and problem solving done in actual field situations by geoscientists. VR environments in a variety of forms are used to prepare students for doing geologic fieldwork, as well as to provide proxies for such experience when…

  14. Experimental Characterization of Piezoelectric Radial Field Diaphragms for Fluidic Control

    Science.gov (United States)

    Bryant, R. G.; Kavli, S. E.; Thomas, R. A., Jr.; Darji, K. J.; Mossi, K. M.

    2004-01-01

    NASA has recently developed a new piezoelectric actuator, the Radial Field Diaphragm or RFD. This actuator uses a radially-directed electric field to generate concentric out-of-plane (Z-axis) motion that allows this packaged device to be used as a pump or valve diaphragm. In order to efficiently use this new active device, experimental determination of pressure, flow rate, mechanical work, power consumption and overall efficiency needs to be determined by actually building a pump. However, without an optimized pump design, it is difficult to assess the quality of the data, as these results are inherent to the actual pump. Hence, separate experiments must be conducted in order to generate independent results to help guide the design criteria and pump quality. This paper focuses on the experiments used to generate the RFD's operational parameters and then compares these results to the experimentally determined results of several types of ball pumps. Also discussed are how errors are inherently introduced into the experiments, the pump design, experimental hardware and their effects on the overall system efficiency.

  15. Awareness descriptions of three PTSD diagnosed patients’ inner experiences before, during and after Thought Field Therapy.

    OpenAIRE

    Martinussen, Anita

    2016-01-01

    SUMMARY Background Thought Field Therapy (TFT) is a psychotherapeutic modality often utilised for single-session trauma treatment. It applies sensory stimulation to desensitise painful feelings, and may thus be called a psycho-sensory therapy. Qualitative research on TFT is particularly scarce, and this processual study seeks to fill that void. Research question How do PTSD patients describe their inner experiences before, during and after Thought Field Therapy? Method Three patients diagnose...

  16. Determination of Quantum Chemistry Based Force Fields for Molecular Dynamics Simulations of Aromatic Polymers

    Science.gov (United States)

    Jaffe, Richard; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    Ab initio quantum chemistry calculations for model molecules can be used to parameterize force fields for molecular dynamics simulations of polymers. Emphasis in our research group is on using quantum chemistry-based force fields for molecular dynamics simulations of organic polymers in the melt and glassy states, but the methodology is applicable to simulations of small molecules, multicomponent systems and solutions. Special attention is paid to deriving reliable descriptions of the non-bonded and electrostatic interactions. Several procedures have been developed for deriving and calibrating these parameters. Our force fields for aromatic polyimide simulations will be described. In this application, the intermolecular interactions are the critical factor in determining many properties of the polymer (including its color).

  17. The AEGIS experiment at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Kellerbauer, A., E-mail: a.kellerbauer@cern.ch [Max Planck Institute for Nuclear Physics (Germany); Allkofer, Y.; Amsler, C. [University of Zurich, Physics Institute (Switzerland); Belov, A. S. [Institute for Nuclear Research of the Russian Academy of Sciences (Russian Federation); Bonomi, G. [University of Brescia, Department of Mechanical and Industrial Engineering (Italy); Braeunig, P. [University of Heidelberg, Kirchhoff Institute for Physics (Germany); Bremer, J. [European Organisation for Nuclear Research, Physics Department (Switzerland); Brusa, R. S. [University of Trento, Department of Physics (Italy); Burghart, G. [European Organisation for Nuclear Research, Physics Department (Switzerland); Cabaret, L. [Centre national de la recherche scientifique, Laboratoire Aime Cotton (France); Canali, C. [University of Zurich, Physics Institute (Switzerland); Castelli, F. [University of Milano, Department of Physics (Italy); Chlouba, K. [Czech Technical University in Prague, Department of Physics (Czech Republic); Cialdi, S. [University of Milano, Department of Physics (Italy); Comparat, D. [Centre national de la recherche scientifique, Laboratoire Aime Cotton (France); Consolati, G. [Politecnico di Milano, Department of Physics (Italy); Dassa, L. [University of Brescia, Department of Mechanical and Industrial Engineering (Italy); Noto, L. Di [University of Trento, Department of Physics (Italy); Donzella, A. [University of Brescia, Department of Mechanical and Industrial Engineering (Italy); Doser, M. [European Organisation for Nuclear Research, Physics Department (Switzerland); Collaboration: AEGIS Collaboration; and others

    2012-05-15

    After the first production of cold antihydrogen by the ATHENA and ATRAP experiments ten years ago, new second-generation experiments are aimed at measuring the fundamental properties of this anti-atom. The goal of AEGIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is to test the weak equivalence principle by studying the gravitational interaction between matter and antimatter with a pulsed, cold antihydrogen beam. The experiment is currently being assembled at CERN's Antiproton Decelerator. In AEGIS, antihydrogen will be produced by charge exchange of cold antiprotons with positronium excited to a high Rydberg state (n > 20). An antihydrogen beam will be produced by controlled acceleration in an electric-field gradient (Stark acceleration). The deflection of the horizontal beam due to its free fall in the gravitational field of the earth will be measured with a moire deflectometer. Initially, the gravitational acceleration will be determined to a precision of 1%, requiring the detection of about 10{sup 5} antihydrogen atoms. In this paper, after a general description, the present status of the experiment will be reviewed.

  18. Variability in Small Hive Beetle (Coleoptera: Nitidulidae) Reproduction in Laboratory and Field Experiments.

    Science.gov (United States)

    Meikle, William G; Holst, Niels; Cook, Steven C; Patt, Joseph M

    2015-06-01

    Experiments were conducted to examine how several key factors affect population growth of the small hive beetle, Aethina tumida Murray (Coleoptera: Nitidulidae). Laboratory experiments were conducted to examine effects of food quantity and temperature on reproduction of cohorts of young A. tumida adults (1:1 sex ratio) housed in experimental arenas. Daily numbers and total mass of larvae exiting arenas were highly variable within treatment. Either one or two cohorts of larvae were observed exiting the arenas. Food quantity, either 10 g or 20 g, did not significantly affect the number of larvae exiting arenas at 32°C, but did at 28°C; arenas provided 20 g food produced significantly more larvae than arenas provided 10 g. Temperature did not affect the total mass of larvae provided 10 g food, but did affect larval mass provided 20 g; beetles kept at 28°C produced more larval mass than at 32°C. Field experiments were conducted to examine A. tumida reproductive success in full strength bee colonies. Beetles were introduced into hives as egg-infested frames and as adults, and some bee colonies were artificially weakened through removal of sealed brood. Efforts were unsuccessful; no larvae were observed exiting from, or during the inspection of, any hives. Possible reasons for these results are discussed. The variability observed in A. tumida reproduction even in controlled laboratory conditions and the difficulty in causing beetle infestations in field experiments involving full colonies suggest that accurately forecasting the A. tumida severity in such colonies will be difficult. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

  19. Preparing beginning reading teachers: An experimental comparison of initial early literacy field experiences

    OpenAIRE

    Al Otaiba, Stephanie; Lake, Vickie E.; Greulich, Luana; Folsom, Jessica S.; Guidry, Lisa

    2012-01-01

    This randomized-control trial examined the learning of preservice teachers taking an initial Early Literacy course in an early childhood education program and of the kindergarten or first grade students they tutored in their field experience. Preservice teachers were randomly assigned to one of two tutoring programs: Book Buddies and Tutor Assisted Intensive Learning Strategies (TAILS), which provided identical meaning-focused instruction (shared book reading), but differed ...

  20. Investigation on wind turbine wakes: wind tunnel tests and field experiments with LIDARs

    Science.gov (United States)

    Iungo, Giacomo; Wu, Ting; Cöeffé, Juliette; Porté-Agel, Fernando; WIRE Team

    2011-11-01

    An investigation on the interaction between atmospheric boundary layer flow and wind turbines is carried out with wind tunnel and LIDAR measurements. The former were carried out using hot-wire anemometry and multi-hole pressure probes in the wake of a three-bladed miniature wind turbine. The wind turbine wake is characterized by a strong velocity defect in the proximity of the rotor, and its recovery is found to depend on the characteristics of the incoming atmospheric boundary layer (mean velocity and turbulence intensity profiles). Field experiments were performed using three wind LIDARs. Bi-dimensional scans are performed in order to analyse the wake wind field with different atmospheric boundary layer conditions. Furthermore, simultaneous measurements with two or three LIDARs allow the reconstruction of multi-component velocity fields. Both LIDAR and wind tunnel measurements highlight an increased turbulence level at the wake boundary for heights comparable to the top-tip of the blades; this flow feature can produce dangerous fatigue loads on following wind turbines.

  1. Preparing culturally and linguistically diverse preservice Early Childhood teachers for field experience

    Directory of Open Access Journals (Sweden)

    Melinda Miller

    2016-07-01

    Full Text Available This article reports on an action research project focussed on preparing culturally and linguistically diverse (CALD preservice early childhood teachers for field experience. A series of targeted workshops delivered over one semester was designed to support the students to develop intercultural competence in relation to knowledge, attitude, skills and behaviours that contribute to success on field placement. Findings indicate that short-term initiatives targeted specifically to students’ identified needs and strengths can help to build intercultural competence for both students and teacher educators. For the participants, access to communication strategies, opportunities for rehearsal of teaching practice, and peer and academic support contributed to shifts in attitude, and the development of skills and new knowledge. New learnings for the teacher educators included challenging assumptions about CALD students’ sense of community and belonging in the university context.

  2. Does the Unemployement Benefit Institution Affect the Productivity of Workers? Evidence from a Field Experiment

    NARCIS (Netherlands)

    Blanco, M.; Dalton, P.S.; Vargas, J.F.

    2013-01-01

    Abstract: We investigate whether and how the type of unemployment bene t institution affects productivity. We designed a field experiment to compare workers' productivity under a welfare system, where the unemployed receive an unconditional monetary transfer, with their productivity under a workfare

  3. Can pictorial warning labels on cigarette packages address smoking-related health disparities?: Field experiments in Mexico to assess warning label content

    Science.gov (United States)

    Thrasher, James F.; Arillo-Santillán, Edna; Villalobos, Victor; Pérez-Hernández, Rosaura; Hammond, David; Carter, Jarvis; Sebrié, Ernesto; Sansores, Raul; Regalado-Piñeda, Justino

    2012-01-01

    Objective This study aimed to determine the most effective content of pictorial health warning labels (HWLs) and whether educational attainment moderates these effects. Methods Field experiments were conducted with 529 adult smokers and 530 young adults (258 nonsmokers; 271 smokers), wherein participants reported responses to different HWLs printed on cigarette packages. One experiment involved manipulating textual form (testimonial narrative vs didactic) and the other involved manipulating imagery type (diseased organs vs human suffering). Results Tests of mean ratings and rankings indicated that HWLs with didactic textual forms had equivalent or significantly higher credibility, relevance, and impact than HWLs with testimonial forms. Results from mixed-effects models confirmed these results. However, responses differed by participant educational attainment: didactic forms were consistently rated higher than testimonials among participants with higher education, whereas the difference between didactic and testimonial narrative forms was weaker or not statistically significant among participants with lower education. In the second experiment, with textual content held constant, greater credibility, relevance and impact was found for graphic imagery of diseased organs than imagery of human suffering. Conclusions Pictorial HWLs with didactic textual forms appear to work better than with testimonial narratives. Future research should determine which pictorial HWL content has the greatest real-world impact among consumers from disadvantaged groups, including assessment of how HWL content should change to maintain its impact as tobacco control environments strengthen and consumer awareness of smoking-related risks increases. PMID:22350859

  4. Acoustic field modulation in regenerators

    Science.gov (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

    2016-12-01

    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  5. Neutron spectrum determination by activation method in fast neutron fields at the RB reactors

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.S.; Pesic, M.P.; Antic, D.P.

    1994-01-01

    The fast neutron fields of the RB reactor are presented in this paper. The activation method for spectrum determination is described and explained. The obtained results for intermediate and fast spectrum are given and discussed. (authors). 7 refs., 3 tabs

  6. Aura, Self, and Aesthetic Experience

    Directory of Open Access Journals (Sweden)

    Marshall Battani

    2011-01-01

    Full Text Available Aesthetic experiences are generated in encounters with cultural objects and such experiences are marked by the free play of cognitive and numinous experience unstructured by concepts. Kant’s famous three types of pleasure, made infamous in social theory by Pierre Bourdieu, are examined in relation to the critical theoretical concept of aura, the social psychology of “flow,” and cognitive explanations of perception to explain experience in aesthetic fields. Theories of aesthetic experience developed at the crossroad of critical social thought and cognitive science hold promise for a social analysis able to avoid the usual sociological pitfalls of either ignoring aesthetics or reducing it to structurally determined differences of taste.

  7. A high voltage pulse generator based on silicon-controlled rectifier for field-reversed configuration experiment.

    Science.gov (United States)

    Lin, Munan; Liu, Ming; Zhu, Guanghui; Wang, Yanpeng; Shi, Peiyun; Sun, Xuan

    2017-08-01

    A high voltage pulse generator based on a silicon-controlled rectifier has been designed and implemented for a field reversed configuration experiment. A critical damping circuit is used in the generator to produce the desired pulse waveform. Depending on the load, the rise time of the output trigger signal can be less than 1 μs, and the peak amplitudes of trigger voltage and current are up to 8 kV and 85 A in a single output. The output voltage can be easily adjusted by changing the voltage on a capacitor of the generator. In addition, the generator integrates an electrically floating heater circuit so it is capable of triggering either pseudosparks (TDI-type hydrogen thyratron) or ignitrons. Details of the circuits and their implementation are described in the paper. The trigger generator has successfully controlled the discharging sequence of the pulsed power supply for a field reversed configuration experiment.

  8. Determining Student Competency in Field Placements: An Emerging Theoretical Model

    Directory of Open Access Journals (Sweden)

    Twyla L. Salm

    2016-06-01

    Full Text Available This paper describes a qualitative case study that explores how twenty-three field advisors, representing three human service professions including education, nursing, and social work, experience the process of assessment with students who are struggling to meet minimum competencies in field placements. Five themes emerged from the analysis of qualitative interviews. The field advisors primary concern was the level of professional competency achieved by practicum students. Related to competency were themes concerned with the field advisor's role in being accountable and protecting the reputation of his/her profession as well as the reputation of the professional program affiliated with the practicum student's professional education. The final theme – teacher-student relationship –emerged from the data, both as a stand-alone and global or umbrella theme. As an umbrella theme, teacher-student relationship permeated each of the other themes as the participants interpreted their experiences of the process of assessment through the mentor relationships. A theoretical model was derived from these findings and the description of the model is presented. Cet article décrit une étude de cas qualitative qui explore comment vingt-trois conseillers de stages, représentant trois professions de services sociaux comprenant l’éducation, les soins infirmiers et le travail social, ont vécu l’expérience du processus d’évaluation avec des étudiants qui ont des difficultés à acquérir les compétences minimales durant les stages. Cinq thèmes ont été identifiés lors de l’analyse des entrevues qualitatives. La préoccupation principale des conseillers de stages était le niveau de compétence professionnelle acquis par les stagiaires. Les thèmes liés à la compétence étaient le rôle des conseillers de stages dans leur responsabilité pour protéger la réputation de leur profession ainsi que la réputation d’un programme professionnel

  9. A Simple Experiment to Determine the Characteristics of an NTC Thermistor for Low-Temperature Measurement Applications

    Science.gov (United States)

    Mawire, A.

    2012-01-01

    A simple low-cost experiment for undergraduate students to determine the characteristics of a negative temperature coefficient of resistance thermistor is presented. The experiment measures the resistance-temperature and voltage-temperature characteristics of the thermistor. Results of the resistance-temperature experiment are used to determine…

  10. Minimizing magnetic fields for precision experiments

    Energy Technology Data Exchange (ETDEWEB)

    Altarev, I.; Fierlinger, P.; Lins, T.; Marino, M. G.; Nießen, B.; Petzoldt, G.; Reisner, M.; Stuiber, S., E-mail: stefan.stuiber@ph.tum.de; Sturm, M.; Taggart Singh, J.; Taubenheim, B. [Physikdepartment, Technische Universität München, D-85748 Garching (Germany); Rohrer, H. K. [Rohrer GmbH, D-80667 München (Germany); Schläpfer, U. [IMEDCO AG, CH-4614 Hägendorf (Switzerland)

    2015-06-21

    An increasing number of measurements in fundamental and applied physics rely on magnetically shielded environments with sub nano-Tesla residual magnetic fields. State of the art magnetically shielded rooms (MSRs) consist of up to seven layers of high permeability materials in combination with highly conductive shields. Proper magnetic equilibration is crucial to obtain such low magnetic fields with small gradients in any MSR. Here, we report on a scheme to magnetically equilibrate MSRs with a 10 times reduced duration of the magnetic equilibration sequence and a significantly lower magnetic field with improved homogeneity. For the search of the neutron's electric dipole moment, our finding corresponds to a 40% improvement of the statistical reach of the measurement. However, this versatile procedure can improve the performance of any MSR for any application.

  11. Minimizing magnetic fields for precision experiments

    International Nuclear Information System (INIS)

    Altarev, I.; Fierlinger, P.; Lins, T.; Marino, M. G.; Nießen, B.; Petzoldt, G.; Reisner, M.; Stuiber, S.; Sturm, M.; Taggart Singh, J.; Taubenheim, B.; Rohrer, H. K.; Schläpfer, U.

    2015-01-01

    An increasing number of measurements in fundamental and applied physics rely on magnetically shielded environments with sub nano-Tesla residual magnetic fields. State of the art magnetically shielded rooms (MSRs) consist of up to seven layers of high permeability materials in combination with highly conductive shields. Proper magnetic equilibration is crucial to obtain such low magnetic fields with small gradients in any MSR. Here, we report on a scheme to magnetically equilibrate MSRs with a 10 times reduced duration of the magnetic equilibration sequence and a significantly lower magnetic field with improved homogeneity. For the search of the neutron's electric dipole moment, our finding corresponds to a 40% improvement of the statistical reach of the measurement. However, this versatile procedure can improve the performance of any MSR for any application

  12. Antimatter gravity experiment

    International Nuclear Information System (INIS)

    Brown, R.E.; Camp, J.B.; Darling, T.W.

    1990-01-01

    An experiment is being developed to measure the acceleration of the antiproton in the gravitational field of the earth. Antiprotons of a few MeV from the LEAR facility at CERN will be slowed, captured, cooled to a temperature of about 10 K, and subsequently launched a few at a time into a drift tube where the effect of gravity on their motion will be determined by a time-of-flight method. Development of the experiment is proceeding at Los Alamos using normal matter. The fabrication of a drift tube that will produce a region of space in which gravity is the dominant force on moving ions is of major difficulty. This involves a study of methods of minimizing the electric fields produced by spatially varying work functions on conducting surfaces. Progress in a number of areas is described, with stress on the drift-tube development

  13. Commentary on "Studying eyewitness investigations in the field": a look forward.

    Science.gov (United States)

    Steblay, Nancy Kay

    2008-02-01

    Schacter et al. (2007, this issue) address the controversy surrounding an Illinois pilot project that attempted to compare sequential versus simultaneous police lineup formats. The statement by these experts will guide the design and execution of future field lineup experiments. This commentary discusses three aspects of field studies that pose challenges as lineup experiments are interpreted: the imprecise meaning of the dependent measure (eyewitness decisions), the limitations of single studies, and the necessity to devise public policy from incomplete knowledge. A combination of laboratory and field information provides the means to determine best practices in eyewitness identification procedures.

  14. Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data: Implications for Models, Retrieval Schemes and Aerosol-Cloud-Radiation Interactions

    Energy Technology Data Exchange (ETDEWEB)

    McFarquhar, Greg [Univ. of Illinois, Urbana, IL (United States)

    2015-12-28

    We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol’s influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects.In this report we describe the accomplishments that we made on all 3 research objectives.

  15. Functional visual fields: a cross-sectional UK study to determine which visual field paradigms best reflect difficulty with mobility function.

    Science.gov (United States)

    Subhi, Hikmat; Latham, Keziah; Myint, Joy; Crossland, Michael

    2017-11-20

    To develop an appropriate method of assessing visual field (VF) loss which reflects its functional consequences, this study aims to determine which method(s) of assessing VF best reflect mobility difficulty. This cross-sectional observational study took place within a single primary care setting. Participants attended a single session at a University Eye Clinic, Cambridge, UK, with data collected by a single researcher (HS), a qualified optometrist. 50 adult participants with peripheral field impairment were recruited for this study. Individuals with conditions not primarily affecting peripheral visual function, such as macular degeneration, were excluded from the study. Participants undertook three custom and one standard binocular VF tests assessing VF to 60°, and also integrated monocular threshold 24-2 visual fields (IVF). Primary VF outcomes were average mean threshold, percentage of stimuli seen and VF area. VF outcomes were compared with self-reported mobility function assessed with the Independent Mobility Questionnaire, and time taken and patient acceptability were also considered. Receiver operating characteristic (ROC) curves determined which tests best predicted difficulty with mobility tasks. Greater VF loss was associated with greater self-reported mobility difficulty with all field paradigms (R 2 0.38-0.48, all Pmobility tasks in ROC analysis. Mean duration of the tests ranged from 1 min 26 s (±9 s) for kinetic assessment to 9 min 23 s (±24 s) for IVF. The binocular VF tests extending to 60° eccentricity all relate similarly to self-reported mobility function, and slightly better than integrated monocular VFs. A kinetic assessment of VF area is quicker than and as effective at predicting mobility function as static threshold assessment. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. Pulsed high-magnetic-field experiments: New insights into the magnetocaloric effect in Ni-Mn-In Heusler alloys

    International Nuclear Information System (INIS)

    Salazar Mejía, C.; Nayak, A. K.; Felser, C.; Nicklas, M.; Ghorbani Zavareh, M.; Wosnitza, J.; Skourski, Y.

    2015-01-01

    The present pulsed high-magnetic-field study on Ni 50 Mn 35 In 15 gives an extra insight into the thermodynamics of the martensitic transformation in Heusler shape-memory alloys. The transformation-entropy change, ΔS, was estimated from field-dependent magnetization experiments in pulsed high magnetic fields and by heat-capacity measurements in static fields. We found a decrease of ΔS with decreasing temperature. This behavior can be understood by considering the different signs of the lattice and magnetic contributions to the total entropy. Our results further imply that the magnetocaloric effect will decrease with decreasing temperature and, furthermore, the martensitic transition is not induced anymore by changing the temperature in high magnetic fields

  17. Experimental determination of temperature fields in sodium-cooled rod bundles with hexagonal rod arrangement and grid spacers

    International Nuclear Information System (INIS)

    Moeller, R.; Tschoeke, H.; Kolodziej, M.

    1977-01-01

    Three-dimensional temperature fields in the claddings of sodium cooled rods were determined experimentally under representative nominal operating conditions for a SNR typical 19-rod bundle model provided with spark-eroded spacers. These experiments are required to verify thermohydraulic computer programs which will provide the output data for strength calculations of the high loaded cladding tubes. In this work the essentials are reported of the measured circumferential distributions of wall temperatures of peripheral rods. In addition the sub-channel temperatures measured over the bundle cross section are indicated, they are required to sustain codes for the global thermohydraulic design of core elements. The most important results are: 1) The whole fuel element is located within the thermal entrance length. 2) High azimuthal temperature differences were measured in the claddings of peripheral rods, which are strongly influenced by the distance between the rod and the shroud, especially for the corner rod. 3) With decreasing Pe-number ( [de

  18. Experiences in Accreditation of Laboratories in the Field of Radiation Science

    International Nuclear Information System (INIS)

    Franic, Z.; Galjanic, S.; Krizanec, D.

    2011-01-01

    Efficient interaction of technical legislation, metrology, standardization and accreditation within the system of quality infrastructure is precondition for assurance of safety of goods and services as well as protection of humans and environment. In the paper importance of quality infrastructure on national and international levels is presented while special interest is paid to accreditation. Current situation regarding the accreditation of laboratories in the field of radiation science is presented. Regarding this field, in Croatia three laboratories are accredited by Croatian Accreditation Agency: 1. Laboratory for Radioecology, Rudjer Boskovic Institute (Scope: Measurement of radionuclide content in environmental samples and commodities - Including foodstuffs and drinking water) 2. EKOTEH Dozimetrija Ltd., Department for Radiation Protection (Scope: Testing in the scope of ionizing and nonionizing radiation) 3. Radiation Protection Unit, Institute for Medical Research and Occupational Health (Scope: Determination of radioactivity). (author)

  19. A variation of the Davis-Smith method for in-flight determination of spacecraft magnetic fields.

    Science.gov (United States)

    Belcher, J. W.

    1973-01-01

    A variation of a procedure developed by Davis and Smith (1968) is presented for the in-flight determination of spacecraft magnetic fields. Both methods take statistical advantage of the observation that fluctuations in the interplanetary magnetic field over short periods of time are primarily changes in direction rather than in magnitude. During typical solar wind conditions between 0.8 and 1.0 AU, a statistical analysis of 2-3 days of continuous interplanetary field measurements yields an estimate of a constant spacecraft field with an uncertainty of plus or minus 0.25 gamma in the direction radial to the sun and plus or minus 15 gammas in the directions transverse to the radial. The method is also of use in estimating variable spacecraft fields with gradients of the order of 0.1 gamma/day and less and in other special circumstances.

  20. [Effect of previous experience in reacting to a danger signal on "open field" behavior in the rat].

    Science.gov (United States)

    Poltyreva, T E; Petrov, E S

    1983-01-01

    Modification of rats behaviour in an "hopen field" test was investigated, induced by an acoustic stimulus, previously subjected to conditioning in a shuttle chamber in experiments with possibility and impossibility of avoidance from electrical shock. It has been established that presentation of a stimulus having the meaning of a danger signal, in a new situation, significantly suppresses investigating behaviour of rats, whereas the stimulus which had not been subjected to conditioning exerts no marked effect on behaviour. The greatest suppression was observed in rats with "learned helplessness". This fact suggests that the degree of suppression of the behaviour in an open field in response to a danger signal, depends on the animal's previous experience in reacting to this signal.

  1. Using Economic Incentives to Reduce Electricity Consumption: A field Experiment in Matsuyama, Japan

    OpenAIRE

    Kenichi Mizobuchi; Kenji Takeuchi

    2012-01-01

    This study examines the effectiveness of economic incentives in promoting electricity-conservation behavior among Japanese households. Fifty-three Japanese households participated in a field experiment and were offered monetary rewards depending on their rate of reduction in electricity consumption. To avoid bias in sample selection, which is typically present in previous studies, we adopted a request-based approach for recruiting participants. Results showed that only 34% of the participants...

  2. A methodology to determine boundary conditions from forced convection experiments using liquid crystal thermography

    Science.gov (United States)

    Jakkareddy, Pradeep S.; Balaji, C.

    2017-02-01

    This paper reports the results of an experimental study to estimate the heat flux and convective heat transfer coefficient using liquid crystal thermography and Bayesian inference in a heat generating sphere, enclosed in a cubical Teflon block. The geometry considered for the experiments comprises a heater inserted in a hollow hemispherical aluminium ball, resulting in a volumetric heat generation source that is placed at the center of the Teflon block. Calibrated thermochromic liquid crystal sheets are used to capture the temperature distribution at the front face of the Teflon block. The forward model is the three dimensional conduction equation which is solved within the Teflon block to obtain steady state temperatures, using COMSOL. Match up experiments are carried out for various velocities by minimizing the residual between TLC and simulated temperatures for every assumed loss coefficient, to obtain a correlation of average Nusselt number against Reynolds number. This is used for prescribing the boundary condition for the solution to the forward model. A surrogate model obtained by artificial neural network built upon the data from COMSOL simulations is used to drive a Markov Chain Monte Carlo based Metropolis Hastings algorithm to generate the samples. Bayesian inference is adopted to solve the inverse problem for determination of heat flux and heat transfer coefficient from the measured temperature field. Point estimates of the posterior like the mean, maximum a posteriori and standard deviation of the retrieved heat flux and convective heat transfer coefficient are reported. Additionally the effect of number of samples on the performance of the estimation process has been investigated.

  3. A three-year experiment confirms continuous immobilization of cadmium and lead in contaminated paddy field with biochar amendment

    International Nuclear Information System (INIS)

    Bian, Rongjun; Joseph, Stephen; Cui, Liqiang; Pan, Genxing; Li, Lianqing; Liu, Xiaoyu; Zhang, Afeng; Rutlidge, Helen; Wong, Singwei; Chia, Chee; Marjo, Chris; Gong, Bin; Munroe, Paul; Donne, Scott

    2014-01-01

    Highlights: • Biochar significantly increased soil pH, organic matter and immobilized soil Cd and Pb. • Biochar treatment consistently reduced rice Cd and Pb content in three years. • Contaminated biochar from the study field contained much higher heavy metals than fresh biochar. • Biochar caused metal immobilization primarily due to the precipitation and surface adsorption. - Abstract: Heavy metal contamination in croplands has been a serious concern because of its high health risk through soil-food chain transfer. A field experiment was conducted in 2010–2012 in a contaminated rice paddy in southern China to determine if bioavailability of soil Cd and Pb could be reduced while grain yield was sustained over 3 years after a single soil amendment of wheat straw biochar. Contaminated biochar particles were separated from the biochar amended soil and microscopically analyzed to help determine where, and how, metals were immobilized with biochar. Biochar soil amendment (BSA) consistently and significantly increased soil pH, total organic carbon and decreased soil extractable Cd and Pb over the 3 year period. While rice plant tissues’ Cd content was significantly reduced, depending on biochar application rate, reduction in plant Pb concentration was found only in root tissue. Analysis of the fresh and contaminated biochar particles indicated that Cd and Pb had probably been bonded with the mineral phases of Al, Fe and P on and around and inside the contaminated biochar particle. Immobilization of the Pb and Cd also occurred to cation exchange on the porous carbon structure

  4. A three-year experiment confirms continuous immobilization of cadmium and lead in contaminated paddy field with biochar amendment

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Rongjun [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Joseph, Stephen [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Discipline of Chemistry, University of Newcastle, Callaghan, NSW 2308 (Australia); Cui, Liqiang [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Pan, Genxing, E-mail: pangenxing@aliyun.com [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Li, Lianqing [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Liu, Xiaoyu; Zhang, Afeng [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Rutlidge, Helen [Solid State and Elemental Analysis Unit, Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW 2052 (Australia); Wong, Singwei [Electron Microscope Unit, University of Newcastle, Callaghan, NSW 2308 (Australia); Chia, Chee [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Marjo, Chris; Gong, Bin [Solid State and Elemental Analysis Unit, Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW 2052 (Australia); Munroe, Paul [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Donne, Scott [Discipline of Chemistry, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2014-05-01

    Highlights: • Biochar significantly increased soil pH, organic matter and immobilized soil Cd and Pb. • Biochar treatment consistently reduced rice Cd and Pb content in three years. • Contaminated biochar from the study field contained much higher heavy metals than fresh biochar. • Biochar caused metal immobilization primarily due to the precipitation and surface adsorption. - Abstract: Heavy metal contamination in croplands has been a serious concern because of its high health risk through soil-food chain transfer. A field experiment was conducted in 2010–2012 in a contaminated rice paddy in southern China to determine if bioavailability of soil Cd and Pb could be reduced while grain yield was sustained over 3 years after a single soil amendment of wheat straw biochar. Contaminated biochar particles were separated from the biochar amended soil and microscopically analyzed to help determine where, and how, metals were immobilized with biochar. Biochar soil amendment (BSA) consistently and significantly increased soil pH, total organic carbon and decreased soil extractable Cd and Pb over the 3 year period. While rice plant tissues’ Cd content was significantly reduced, depending on biochar application rate, reduction in plant Pb concentration was found only in root tissue. Analysis of the fresh and contaminated biochar particles indicated that Cd and Pb had probably been bonded with the mineral phases of Al, Fe and P on and around and inside the contaminated biochar particle. Immobilization of the Pb and Cd also occurred to cation exchange on the porous carbon structure.

  5. Experiments on a Toroidal Screw Pinch with Various Field Programming

    Energy Technology Data Exchange (ETDEWEB)

    Zwicker, H.; Wilhelm, R.; Krause, H. [Max-Planck-Institut Fuer Plasmaphysik, EURATOM-Association, Garching, Munich, Federal Republic of Germany (Germany)

    1971-10-15

    In the toroidal screw pinch ISAR-IV (large diameter 60 cm, aspect ratio 5, maximum storage, energy 140 kj) attempts were made to get an improved stability of the plasma by different kinds of field programming. The best results were obtained with positive trapped B{sub z}-fields and simultaneous switching of main B{sub z}-field and I{sub z}-current. In this case the dense plasma column (n{sub e} Almost-Equal-To 2-3 x 10{sup 16} , kT Almost-Equal-To 50-100 eV, {beta} Almost-Equal-To 15-20%) is surrounded by a force-free plasma ({beta} = 1%) with weak shear and it behaves stably for, at least, 25 {mu}s. The resulting containment time nr of near 10{sup 12} s cm{sup -3} remains a factor of 2-3 below the upper limit given by the classical diffusion. The following loss of the equilibrium position near the coil axis ({Delta} Almost-Equal-To 1-2 cm) is connected to a strong damping of the axial plasma current which starts near the end of the containment. It may be assumed that the increase of the effective plasma resistance mainly results from a contact of the force-free regions with the tube wall. Attempts were made to improve the containment by suitable programming of a plasma z-current. The results are presented. Experiments with one quartz limiter inside the torus improved the equilibrium but introduced instabilities at the new surface of the dilute plasma. To obtain more information about the outer region, the dilute plasma was produced without a dense core and separated from the tube walls by weak adiabatic compression. Under these Tokamak-like conditions the q-value was varied. In the region of q Almost-Equal-To 1 there appeared instabilities which seem to haver higher m-modes and rather short wavelengths. In a different kind of field programming the field distribution of the ''diffuse pinch'' was realized within an accuracy of 5-10% (kT Almost-Equal-To 100 eV, {beta} Almost-Equal-To 30%). In contrast to the predictions of MHD-theory, stability was observed only for

  6. AirSWOT flights and field campaigns for the 2017 Arctic-Boreal Vulnerability Experiment (ABoVE)

    Science.gov (United States)

    Smith, L. C.; Pavelsky, T.; Lettenmaier, D. P.; Gleason, C. J.; Pietroniro, A.; Applejohn, A.; Arvesen, J. C.; Bjella, K.; Carter, T.; Chao, R.; Cooley, S. W.; Cooper, M. G.; Cretaux, J. F.; Douglass, T.; Faria, D.; Fayne, J.; Fiset, J. M.; Goodman, S.; Hanna, B.; Harlan, M.; Langhorst, T.; Marsh, P.; Moreira, D. M.; Minear, J. T.; Onclin, C.; Overstreet, B. T.; Peters, D.; Pettit, J.; Pitcher, L. H.; Russell, M.; Spence, C.; Topp, S.; Turner, K. W.; Vimal, S.; Wilcox, E.; Woodward, J.; Yang, D.; Zaino, A.

    2017-12-01

    Some 50% of Canada and 80% of Alaska is thought to be underlain by permafrost, influencing the hydrology, ecology and carbon cycles of Arctic-Boreal landscapes. This influence includes enhanced presence of millions of lakes and wetlands, which release trace gases while supporting critical ecosystems and traditional subsistence economies. Permafrost is challenging to infer from remote sensing and difficult to sample in the field. A series of 2017 AirSWOT flights flown for the NASA Arctic-Boreal Vulnerability Experiment (ABoVE) will study whether small variations in water surface elevations (WSEs) of Arctic-Boreal lakes are sensitive to presence and/or disturbance of permafrost. AirSWOT is an experimental NASA airborne radar designed to map WSE and a precursor to SWOT, a forthcoming NASA/CNES/CSA satellite mission to map WSE globally with launch in 2021. The ABoVE AirSWOT flight experiments adopted long flight lines of the broader ABoVE effort to traverse broad spatial gradients of permafrost, climate, ecology, and geology. AirSWOT acquisitions consisted of long (1000s of kilometers) strips of Ka-band interferometric radar imagery, and high resolution visible/NIR imagery and DEMs from a digital Cirrus CIR camera. Intensive AirSWOT mapping and ground-based GPS field surveys were conducted at 11 field sites for eight study areas of Canada and Alaska: 1) Saint-Denis, Redberry Lake, North Saskatchewan River (Saskatchewan); 2) Peace-Athabasca Delta (Alberta); 3) Slave River Delta (N.W.T.); 4) Canadian Shield (Yellowknife area, Daring Lake, N.W.T.); 5) Mackenzie River (Inuvik-Tuktoyaktuk corridor, N.W.T.); 6) Old Crow Flats (Yukon Territory); 7) Sagavanirktok River (Alaska); 8) Yukon Flats (Alaska). Extensive ground campaigns were conducted by U.S. and Canadian collaborators to collect high quality surveys of lake WSE, river WSE and discharge, and shoreline locations. Field experiments included traditional and novel GPS surveying methods, including custom-built GPS buoys

  7. Integrating geoscience and Native American experiences through a multi-state geoscience field trip for high school students

    Science.gov (United States)

    Kelso, P. R.; Brown, L. M.; Spencer, M.; Sabatine, S.; Goetz, E. R.

    2012-12-01

    Lake Superior State University (LSSU) developed the GRANITE (Geological Reasoning And Natives Investigating The Earth) to engage high school students in the geosciences. The GRANITE program's target audience is Native American high school students and other populations underrepresented in the geosciences. Through the GRANITE program students undertake a variety of field and laboratory geosciences activities that culminates in a two week summer geoscience field experience during which they travel from Michigan to Wyoming. The sites students visit were selected because of their interesting and diverse geologic features and because in many cases they have special significance to Native American communities. Examples of the processes and localities studied by GRANITE students include igneous processes at Bear Butte, SD (Mato Paha) and Devil's Tower, WY (Mato Tipila); sedimentary processes in the Badlands, SD (Mako Sica) and Black Hills, SD (Paha Sapa); karst processes at Wind Cave, SD (Wasun Niye) and Vore Buffalo Jump; structural processes at Van Hise rock, WI and Dillon normal fault Badlands, SD; hydrologic and laucustrine processes along the Great Lakes and at the Fond du Lac Reservation, MN; fluvial processes along the Mississippi and Missouri rivers; geologic resources at the Homestake Mine, SD and Champion Mine, MI; and metamorphic processes at Pipestone, MN and Baraboo, WI. Through the GRANITE experience students develop an understanding of how geoscience is an important part of their lives, their communities and the world around them. The GRANITE program also promotes each student's growth and confidence to attend college and stresses the importance of taking challenging math and science courses in high school. Geoscience career opportunities are discussed at specific geologic localities and through general discussions. GRANITE students learn geosciences concepts and their application to Native communities and society in general through activities and

  8. Immission protection law aspects of the determination of limiting values for electromagnetic fields

    International Nuclear Information System (INIS)

    Rebentisch, M.

    1994-01-01

    The discussion on the effects of electromagnetic fields on human beings is mostly concentrated on the question of how low the binding limiting values for this should be set. This does not nearly cover the multi-layer legal problems which arise in determining the limiting value. The article tackles the width of the problems. (orig.) [de

  9. Re-examination of spheromak experiments and opportunities

    International Nuclear Information System (INIS)

    Hooper, B.E.; Hammer, J.H.; Barnes, C.W.; Fernandez, J.C.; Wysocki, F.J.

    1996-01-01

    The results of spheromak experiments are reexamined in light of the hypothesis that the core energy confinement is considerably better than the global confinement and that it extrapolates favorably with magnetic Reynolds number S. The data in decaying spheromaks are found to be consistent with the hypothesis and with magnetic fluctuations scaling as S -1/2 and determining the electron thermal conductivity. No conclusion is drawn from the data for sustained spheromaks, indicating the importance of a new experiment to determine core energy confinement while helicity is injected. The characteristics of such an experiment are discussed, including the importance of using modern vacuum and wall-conditioning techniques and of minimizing magnetic field errors. 44 refs., 7 figs., 1 tab

  10. Determination and analysis of uptake of gaseous hydrogen peroxide by red spruce seedlings, determined by CSTR-type chamber experiments

    International Nuclear Information System (INIS)

    Claiborn, C.S.; Aneja, V.P.; Carbonell, R.G.

    1991-01-01

    In order to better understand the pathways for damage, the fate of gaseous hydrogen peroxide in red spruce needles was examined. The uptake of gaseous hydrogen peroxide by red spruce trees was determined from controlled exposure chamber experiments in which the chamber behaved as a Continuous Stirred Tank Reactor (CSTR). The results from these experiments were analyzed using a detailed transport model developed from fundamental principles, in order to determine the fate of hydrogen peroxide in the needles and characterize the exposure. The chamber was specially designed to accommodate highly reactive gases. All inner surfaces were Teflon-coated to minimize wall losses. Fluxes of hydrogen peroxide, carbon dioxide, and water vapor were determined. Both daytime and nighttime conditions were examined. Although other investigators have reported that the flux of other, less water-soluble pollutants to red spruce decreases at night when the stomata closes, the hydrogen peroxide flux did not exhibit this behavior. The results of these studies suggest that, at the concentrations observed in the atmosphere, hydrogen peroxide does not reach the inner, mesophyll tissues, but is lost in water condensing in the cuticular wax residing in the stomatal antechamber, above the stomata. The implications of the condensation in the stomatal antechamber and subsequent reactions occurring in this water for forest damage are discussed

  11. Meta-analysis of field experiments shows no change in racial discrimination in hiring over time.

    Science.gov (United States)

    Quillian, Lincoln; Pager, Devah; Hexel, Ole; Midtbøen, Arnfinn H

    2017-10-10

    This study investigates change over time in the level of hiring discrimination in US labor markets. We perform a meta-analysis of every available field experiment of hiring discrimination against African Americans or Latinos ( n = 28). Together, these studies represent 55,842 applications submitted for 26,326 positions. We focus on trends since 1989 ( n = 24 studies), when field experiments became more common and improved methodologically. Since 1989, whites receive on average 36% more callbacks than African Americans, and 24% more callbacks than Latinos. We observe no change in the level of hiring discrimination against African Americans over the past 25 years, although we find modest evidence of a decline in discrimination against Latinos. Accounting for applicant education, applicant gender, study method, occupational groups, and local labor market conditions does little to alter this result. Contrary to claims of declining discrimination in American society, our estimates suggest that levels of discrimination remain largely unchanged, at least at the point of hire.

  12. An Overview of the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE)

    Science.gov (United States)

    Sellers, P. J.; Hall, F. G.; Asrar, G.; Strebel, D. E.; Murphy, R. E.

    1992-11-01

    In the summer of 1983 a group of scientists working in the fields of meteorology, biology, and remote sensing met to discuss methods for modeling and observing land-surface—atmosphere interactions on regional and global scales. They concluded, first, that the existing climate models contained poor representations of the processes controlling the exchanges of energy, water, heat, and carbon between the land surface and the atmosphere and, second, that satellite remote sensing had been underutilized as a means of specifying global fields of the governing biophysical parameters. Accordingly, a multiscale, multidisciplinary experiment, FIFE, was initiated to address these two issues. The objectives of FIFE were specified as follows: (1) Upscale integration of models: The experiment was designed to test the soil-plant-atmosphere models developed by biometeorologists for small-scale applications (millimeters to meters) and to develop methods to apply them at the larger scales (kilometers) appropriate to atmospheric models and satellite remote sensing. (2) Application of satellite remote sensing: Even if the first goal were achieved to yield a "perfect" model of vegetation-atmosphere exchanges, it would have very limited applications without a global observing system for initialization and validation. As a result, the experiment was tasked with exploring methods for using satellite data to quantify important biophysical states and rates for model input. The experiment was centered on a 15 × 15 km grassland site near Manhattan, Kansas. This area became the focus for an extended monitoring program of satellite, meteorological, biophysical, and hydrological data acquisition from early 1987 through October 1989 and a series of 12- to 20-day intensive field campaigns (IFCs), four in 1987 and one in 1989. During the IFCs the fluxes of heat, moisture, carbon dioxide, and radiation were measured with surface and airborne equipment in coordination with measurements of surface

  13. Integrating watershed hydrology and economics to establish a local market for water quality improvement: A field experiment.

    Science.gov (United States)

    Uchida, Emi; Swallow, Stephen K; Gold, Arthur; Opaluch, James; Kafle, Achyut; Merrill, Nathaniel; Michaud, Clayton; Gill, Carrie Anne

    2018-04-01

    Innovative market mechanisms are being increasingly recognized as effective decision-making institutions to incorporate the value of ecosystem services into the economy. We present a field experiment that integrates an economic auction and a biophysical water flux model to develop a local market process consisting of both the supply and demand sides. On the supply side, we operate an auction with small-scale livestock owners who bid for contracts to implement site-specific manure management practices that reduce phosphorus loadings to a major reservoir. On the demand side, we implement a real money, multi-unit public good auction for these contracts with residents who potentially benefit from reduced water quality risks. The experiments allow us to construct supply and demand curves to find an equilibrium price for water quality improvement. The field experiments provide a proof-of-concept for practical implementation of a local market for environmental improvements, even for the challenging context of nonpoint pollution.

  14. Marine Radioactivity Studies in the Suez Canal, Part II: Field Experiments and a Modelling Study of Dispersion

    Science.gov (United States)

    Abril, J. M.; Abdel-Aal, M. M.; Al-Gamal, S. A.; Abdel-Hay, F. A.; Zahar, H. M.

    2000-04-01

    In this paper we take advantage of the two field tracing experiments carried out under the IAEA project EGY/07/002, to develop a modelling study on the dispersion of radioactive pollution in the Suez Canal. The experiments were accomplished by using rhodamine B as a tracer, and water samples were measured by luminescence spectrometry. The presence of natural luminescent particles in the canal waters limited the use of some field data. During experiments, water levels, velocities, wind and other physical parameters were recorded to supply appropriate information for the modelling work. From this data set, the hydrodynamics of the studied area has been reasonably described. We apply a 1-D-Gaussian and 2-D modelling approaches to predict the position and the spatial shape of the plume. The use of different formulations for dispersion coefficients is studied. These dispersion coefficients are then applied in a 2-D-hydrodynamic and dispersion model for the Bitter Lake to investigate different scenarios of accidental discharges.

  15. Corrections for a constant radial magnetic field in the muon g - 2 and electric-dipole-moment experiments in storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Silenko, Alexander J. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation)

    2017-10-15

    We calculate the corrections for constant radial magnetic field in muon g - 2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of g - 2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab. (orig.)

  16. The identifiable victim effect in charitable giving: evidence from a natural field experiment

    DEFF Research Database (Denmark)

    Lesner, Tine; Rasmussen, O. D.

    2014-01-01

    or a statistical victim. Unlike much previous research, which has used only laboratory experiments, we find that the campaign letter focusing on one identifiable victim did not result in significantly larger donations than the campaign letter focusing on the statistical victim. In addition to the role......We design a natural field experiment to enhance our understanding of the role of the identifiable victim effect in charitable giving. Using direct mail solicitations to 25797 prior donors of a nonprofit charity, we tested the responsiveness of donors to make a contribution to either an identifiable...... campaigns. We find some evidence of crowding out, indicating that charitable giving could be a zero-sum game; however, the treatment letters did not have different effects on other payments....

  17. Lessons in collaboration and effective field research from the Appalachian Headwaters Research Experience for Undergraduates Program

    Science.gov (United States)

    Jones, A. L.; Fox, J.; Wilder, M. S.

    2009-12-01

    In the summer of 2009, the authors launched year one of a three-year National Science Foundation-funded Research Experience for Undergraduates entitled "Carbon Storage and Headwater Health in the Appalachian Headwaters." Eight undergraduates selected from a nationally competitive field of more than 60 applicants participated in the ten-week field- and laboratory-based program along with three middle- and high-school teachers. Each student developed and completed an independent research project related to coal mining’s impact on soil organic carbon and sediment transport processes. Specifically, they used isotope ratio mass spectrometry to measure the carbon and nitrogen stable isotopic signature of soils and sediments in the Appalachian headwater landscapes and first order streams of Kentucky's southeastern coalfields. Among the program's innovative features was its fundamentally collaborative nature--which was represented in several ways. First, the background of the three program leaders was very different: an environmental planner with an academic background in land use planning and administration (Jones); a civil engineer trained in biogeochemistry and watershed modeling (Fox); and an environmental educator experienced in both formal and nonformal educator training and certification (Wilder). The program was also a collaboration between a Carnegie 1 research-oriented institution and an undergraduate/ teaching -focused regional comprehensive university. Finally, the participants themselves represented a diversity of disciplines and institutional backgrounds--including biology, geology, chemistry, environmental science and civil engineering. The Research Experience for Teachers component was another innovative program element. The teachers participated in all field and laboratory research activities during the first six weeks, then developed a unit of study for their own classrooms to be implemented during the current school year. In addition to the six

  18. Foucault pendulum at the south pole: Proposal for an experiment to detect the earth's general relativistic gravitomagnetic field

    International Nuclear Information System (INIS)

    Braginsky, V.B.; Polnarev, A.G.; Thorne, K.S.

    1984-01-01

    An experiment is proposed for measuring the earth's gravitomagnetic field by monitoring its effect on the plane of swing of a Foucault pendulum at the south pole (''dragging of inertial frames by earth's rotation''). With great effort a 10% experiment in a measurement time of several months might be achieved

  19. Rapid characterization of superconducting wires and tapes in strong pulsed magnetic fields

    International Nuclear Information System (INIS)

    Bockstal, L. van; Keyser, A. de; Deschagt, J.; Hopkins, S.C.; Glowacki, B.A.

    2007-01-01

    A new measurement system for rapid characterization of superconducting wires and tapes is developed. The CryoPulse-BI is a system to provide a direct measurement of critical material parameters for superconducting materials when high long pulsed magnetic fields and strong currents are applied. In the experiments, synchronized magnetic fields up to 30 T and current pulses up to 5 kA are generated with adjustable timing. Varying the magnetic field strength, the current through the sample and the BI timing allows for a thorough characterization of the sample and the determination of critical currents. The rapid cycle time of the experiments yields a rapid and thorough determination of the critical parameters. The method has been tested on low T c as well as high T c materials with the field parallel or perpendicular to the current. The discussion covers the current state of the art including a comparison of our results to classical DC characterization measurements

  20. Impacts of distinct observations during the 2009 Prince William Sound field experiment: A data assimilation study

    Science.gov (United States)

    Li, Z.; Chao, Y.; Farrara, J.; McWilliams, J. C.

    2012-12-01

    A set of data assimilation experiments, known as Observing System Experiments (OSEs), are performed to assess the relative impacts of different types of observations acquired during the 2009 Prince William Sound Field Experiment. The observations assimilated consist primarily of three types: High Frequency (HF) radar surface velocities, vertical profiles of temperature/salinity (T/S) measured by ships, moorings, Autonomous Underwater Vehicles and gliders, and satellite sea surface temperatures (SSTs). The impact of all the observations, HF radar surface velocities, and T/S profiles is assessed. Without data assimilation, a frequently occurring cyclonic eddy in the central Sound is overly persistent and intense. The assimilation of the HF radar velocities effectively reduces these biases and improves the representation of the velocities as well as the T/S fields in the Sound. The assimilation of the T/S profiles improves the large scale representation of the temperature/salinity and also the velocity field in the central Sound. The combination of the HF radar surface velocities and sparse T/S profiles results in an observing system capable of representing the circulation in the Sound reliably and thus producing analyses and forecasts with useful skill. It is suggested that a potentially promising observing network could be based on satellite SSHs and SSTs along with sparse T/S profiles, and future satellite SSHs with wide swath coverage and higher resolution may offer excellent data that will be of great use for predicting the circulation in the Sound.