WorldWideScience

Sample records for comparing field investigations

  1. COMPARATIVE FIELD EXPERIMENTAL INVESTIGATIONS OF DIFFERENT FLAT PLATE SOLAR COLLECTORS

    Directory of Open Access Journals (Sweden)

    Guangming Chen

    2015-12-01

    Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

  2. Comparative investigation of ELM control based on toroidal modelling of plasma response to RMP fields

    Science.gov (United States)

    Liu, Yueqiang

    2016-10-01

    The type-I edge localized mode (ELM), bursting at low frequency and with large amplitude, can channel a substantial amount of the plasma thermal energy into the surrounding plasma-facing components in tokamak devices operating at the high-confinement mode, potentially causing severe material damages. Learning effective ways of controlling this instability is thus an urgent issue in fusion research, in particular in view of the next generation large devices such as ITER and DEMO. Among other means, externally applied, three-dimensional resonant magnetic perturbation (RMP) fields have been experimentally demonstrated to be successful in mitigating or suppressing the type-I ELM, in multiple existing devices. In this work, we shall report results of a comparative study of ELM control using RMPs. Comparison is made between the modelled plasma response to the 3D external fields and the observed change of the ELM behaviour on multiple devices, including MAST, ASDEX Upgrade, EAST, DIII-D, JET, and KSTAR. We show that toroidal modelling of the plasma response, based on linear and quasi-linear magnetohydrodynamic (MHD) models, provides essential insights that are useful in interpreting and guiding the ELM control experiments. In particular, linear toroidal modelling results, using the MARS-F code, reveal the crucial role of the edge localized peeling-tearing mode response during ELM mitigation/suppression on all these devices. Such response often leads to strong peaking of the plasma surface displacement near the region of weak equilibrium poloidal field (e.g. the X-point), and this provides an alternative practical criterion for ELM control, as opposed to the vacuum field based Chirikov criteria. Quasi-linear modelling using MARS-Q provides quantitative interpretation of the side effects due to the ELM control coils, on the plasma toroidal momentum and particle confinements. The particular role of the momentum and particle fluxes, associated with the neoclassical toroidal

  3. The Juno Magnetic Field Investigation

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Benn, Mathias; Bjarnø, Jonas Bækby

    2017-01-01

    The Juno Magnetic Field investigation (MAG) characterizes Jupiter’s planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor ...

  4. The Juno Magnetic Field Investigation

    Science.gov (United States)

    Connerney, J. E. P.; Benn, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.; Murphy, S.; Odom, J.; Oliversen, R.; Schnurr, R.; Sheppard, D.; Smith, E. J.

    2017-02-01

    The Juno Magnetic Field investigation (MAG) characterizes Jupiter's planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to ˜20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 × 106 nT per axis) with a resolution of ˜0.05 nT in the most sensitive dynamic range (±1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through the imager field of

  5. The Juno Magnetic Field Investigation

    Science.gov (United States)

    Connerney, J. E. P.; Benna, M.; Bjarno, J. B.; Denver, T.; Espley, J.; Jorgensen, J. L.; Jorgensen, P. S.; Lawton, P.; Malinnikova, A.; Merayo, J. M.; hide

    2017-01-01

    The Juno Magnetic Field investigation (MAG) characterizes Jupiter's planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to approx. 20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 x 10(exp. 6) nT per axis) with a resolution of approx. 0.05 nT in the most sensitive dynamic range (+/-1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through

  6. The MAVEN Magnetic Field Investigation

    Science.gov (United States)

    Connerney, J. E. P.; Espley, J.; Lawton, P.; Murphy, S.; Odom, J.; Oliversen, R.; Sheppard, D.

    2014-01-01

    The MAVEN magnetic field investigation is part of a comprehensive particles and fields subsystem that will measure the magnetic and electric fields and plasma environment of Mars and its interaction with the solar wind. The magnetic field instrumentation consists of two independent tri-axial fluxgate magnetometer sensors, remotely mounted at the outer extremity of the two solar arrays on small extensions ("boomlets"). The sensors are controlled by independent and functionally identical electronics assemblies that are integrated within the particles and fields subsystem and draw their power from redundant power supplies within that system. Each magnetometer measures the ambient vector magnetic field over a wide dynamic range (to 65,536 nT per axis) with a quantization uncertainty of 0.008 nT in the most sensitive dynamic range and an accuracy of better than 0.05%. Both magnetometers sample the ambient magnetic field at an intrinsic sample rate of 32 vector samples per second. Telemetry is transferred from each magnetometer to the particles and fields package once per second and subsequently passed to the spacecraft after some reformatting. The magnetic field data volume may be reduced by averaging and decimation, when necessary to meet telemetry allocations, and application of data compression, utilizing a lossless 8-bit differencing scheme. The MAVEN magnetic field experiment may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors and the MAVEN mission plan provides for occasional spacecraft maneuvers - multiple rotations about the spacecraft x and z axes - to characterize spacecraft fields and/or instrument offsets in flight.

  7. Comparative investigation of various cellulase assay procedures

    Energy Technology Data Exchange (ETDEWEB)

    Canevascini, G.; Gattlen, C.

    1981-07-01

    The cellulolytic activity of crude enzyme preparations from different cellulolytic fungi (namely Trichoderma viride, Trichoderma koningii, Fusarium solani, Sporotrichum pulverulentum, Sporotrichum thermophile) was assayed comparatively with several common analytical procedures described in the literature. The investigation was carried out with the objective of evaluating, with raw culture filtrates, the different cellulase tests in relation to their specificity for endo- and exo-cellulase action as well as to allow comparisons to be made between results from different research groups using different methods. 1) Cellulase activity was tested viscometrically as well as chemically (determination of reducing end groups) with different carboxymethylcelluloses as substrates. Essentially constant ratios between both kinds of activities were obtained, indicating that they are directly related. By estimating cellulase activity with insoluble cellulosic substrates no direct relationship could be established with the above-described activities except in the case where the cellulose was amorphous. The ratio profile between activities thus obtained and endo-cellulase activities determined viscometrically shows that some enzyme preparations (such as those from both Trichoderma sp.) are clearly more active than others against crystalline cellulose reflecting quantitative differences in enzyme composition. Nevertheless, for a biological understanding of cellulolysis, analytical procedures using crystalline celluloses are not adequate for specifically monitoring exo-cellulase activity in crude enzyme solutions for essentially two reasons: a) they are not sufficiently sensitive to detect small changes in enzyme activity during the early phase of growth, and b) exo-cellulase activity in crude enzyme solutions also depends on the endo-cellulase activity present. (Refs. 39).

  8. Some results of Moon's gravitational field investigations

    Science.gov (United States)

    Haigel, Y. I.; Zazulyak, P. M.

    2016-10-01

    The task of studying the gravitational field of the moon is important for long-term planning of its research using manned and robotic spacecrafts. Determination of harmonic expansion coefficients of selenopotential may not be reliable because of their construction based on different data and different methods of mathematical processing. With mutual comparative assessment of selenopotential models we can get some information about the reliability determination harmonic coefficients.

  9. Progress with field investigations at Stripa

    Energy Technology Data Exchange (ETDEWEB)

    Witherspoon, P.A.; Cook, N.G.W.; Gale, J.E.

    1980-02-01

    It is generally agreed that the most practicable method of isolating nuclear wastes from the biosphere is by deep burial in suitable geologic formations. Such burial achieves a high degree of physical isolation but raises questions concerning the rate at which some of these wastes may return to the biosphere through transport by groundwater. Any suitable repository site will be disturbed first by the excavation of the repository and second by the thermal pulse caused by the radioactive decay of the wastes. To assess the effectiveness of geologic isolation it is necessary to develop the capability of predicting the response of a rock mass to such a thermal pulse. Ultimately, this requires field measurements at depths below surface and in media representative of those likely to be encountered at an actual repository. Access to a granitic rock mass adjacent to a defunct iron ore mine at Stripa in Sweden at a depth of about 350 m below surface has provided a unique opportunity to conduct a comprehensive suite of hydrological and thermo-mechanical experiments under such conditions virtually without delay. The results of these field tests have shown the importance of geologic structure and the functional dependence of the thermo-mechanical properties on temperature in developing a valid predictive model. The results have also demonstrated the vital importance of being able to carry out large scale investigations in a field test facility.

  10. Hurricane Ike: Field Investigation Survey (Invited)

    Science.gov (United States)

    Ewing, L.

    2009-12-01

    Hurricane Ike made landfall at 2:10 a.m. on September 13, 2008, as a Category 2 hurricane. The eye of the hurricane crossed over the eastern end of Galveston Island and a large region of the Texas and Louisiana coast experienced extreme winds, waves and water levels, resulting in large impacts from overtopping, overwash, wind and wave forces and flooding. Major damage stretched from Freeport to the southwest and to Port Arthur to the northeast. The effects of the hurricane force winds were felt well inland in Texas and Louisiana and the storm continued to the interior of the US, causing more damage and loss of life. Through the support of the Coasts, Oceans, Ports and Rivers Institute (COPRI) of the American Society of Civil Engineers (ASCE) a team of 14 coastal scientists and engineers inspected the upper Texas coast in early October 2008. The COPRI team surveyed Hurricane Ike’s effects on coastal landforms, structures, marinas, shore protection systems, and other infrastructure. Damages ranges from very minor to complete destruction, depending upon location and elevation. Bolivar Peninsula, to the right of the hurricane path, experienced severe damage and three peninsula communities were completely destroyed. Significant flood and wave damage also was observed in Galveston Island and Brazoria County that were both on the left side of the hurricane path. Beach erosion and prominent overwash fans were observed throughout much of the field investigation area. The post-storm damage survey served to confirm expected performance under extreme conditions, as well as to evaluate recent development trends and conditions unique to each storm. Hurricane Ike confirmed many previously reported observations. One of the main conclusions from the inspection of buildings was that elevation was a key determinant for survival. Elevation is also a major factor in the stability and effectiveness of shore protection. The Galveston Seawall was high enough to provide protection from

  11. Federal Bureau of Investigation (FBI) Field Office Jurisdiction/Divisions

    Data.gov (United States)

    Department of Homeland Security — This dataset represents the FBI (Federal Bureau of Investigations) national field office jurisdiction/divisional boundary locations. The field offices are centrally...

  12. Investigation of an angular spectrum approach for pulsed ultrasound fields

    DEFF Research Database (Denmark)

    Du, Yigang; Jensen, Henrik; Jensen, Jørgen Arendt

    2013-01-01

    sources are compared to the Field II simulated and hydroph one measure dpulses, respectively. The total relative root mean squar e(RMS)errors of the pulsed ASA are investigated by using different time-point, zero-padding factors, spatial sampling interval and temporal sampling frequency in the sim ulation....... Optim al parameters for the ASA are found in the simulation .The RMS error of the ASA simulation is reduced from 10.9% to 2.4% for the optimal parameters when comparing to Field II simulation s. The comparison between the ASA calculated and measured pulses are illustrated and the corresponding RMS error......An Angular Spectrum Approach (ASA)is formulated and employed to simulate linear pulsed ultra sound fields for high bandwidth signals. Ageometrically focused piston transducer is used as the acoustic source. Signals are cross-correlated to findthe true sound speed during the measurement to make...

  13. Manus Water Isotope Investigation Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Jessica L [University of Illinois, Urbana-Champaign; Cobb, Kim M [Georgia Institute of Technology; Noone, David [University of Colorado, Boulder

    2016-03-01

    The objective of this field campaign was to investigate climatic controls on the stable isotopic composition of water vapor, precipitation, and seawater in the western tropical Pacific. Simultaneous measurements of the stable isotopic composition of vapor and precipitation from April 28 to May 8, 2013, at the Manus Tropical Western Pacific Atmospheric Radiation Measurement site, provided several key insights into the nature of the climate signal archived in precipitation and vapor isotope ratios. We observed a large shift from lower to higher isotopic values in vapor and precipitation because of the passage of a mesoscale convective system west of the site and a transition from a regional stormy period into a more quiescent period. During the quiescent period, the stable isotopic composition of vapor and precipitation indicated the predominance of oceanic evaporation in determining the isotopic composition of boundary-layer vapor and local precipitation. There was not a consistent relationship between intra-event precipitation amount at the site and the stable isotopic composition of precipitation, thus challenging simplified assumptions about the isotopic “amount effect” in the tropics on the time scale of individual storms. However, some storms did show an amount effect, and deuterium excess values in precipitation had a significant relationship with several meteorological variables, including precipitation, temperature, relative humidity, and cloud base height across all measured storms. The direction of these relationships points to condensation controls on precipitation deuterium excess values on intra-event time scales. The relationship between simultaneous measurements of vapor and precipitation isotope ratios during precipitation events indicates the ratio of precipitation-to-vapor isotope ratios can diagnose precipitation originating from a vapor source unique from boundary-layer vapor and rain re-evaporation.

  14. Field investigation of the drift shadow

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-08

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

  15. Investigations of field instability of ferrofluid in hypergravity and microgravity

    Directory of Open Access Journals (Sweden)

    Theng Yee Chong

    2012-03-01

    Full Text Available The field instability of the free surface of ferrofluid was investigated under microgravity and hypergravity environments conducted by parabolic flight. It is observed that the perturbation was suppressed under hypergravity, whereas at the microgravity condition, it appeared to have only slight increase in the amplitude of the perturbation peaks compared to the case of ground condition. Besides, an observation of peak-trough distance showed that not only the peak, but the trough was also very much dependent on the applied magnetic field. The difference of magnetic pole (north and south had shown to be a factor to the perturbation as well.

  16. Barchan dune corridors: Field characterization and investigation of control parameters

    Science.gov (United States)

    Elbelrhiti, H.; Andreotti, B.; Claudin, P.

    2008-06-01

    The structure of the barchan field located between Tarfaya and Laayoune (Atlantic Sahara, Morocco) is quantitatively investigated and compared to that in La Pampa de la Joya (Arequipa, Peru). On the basis of field measurements, we show how the volume, the velocity, and the output sand flux of a dune can be computed from the value of its body and horn widths. The dune size distribution is obtained from the analysis of aerial photographs. It shows that these fields are in a statistically homogeneous state along the wind direction and present a "corridor" structure in the transverse direction, in which the dunes have a rather well selected size. Investigating the possible external parameters controlling these corridors, we demonstrate that none among topography, granulometry, wind, and sand flux is relevant. We finally discuss the dynamical processes at work in these fields (collisions and wind fluctuations) and investigate the way they could regulate the size of the dunes. Furthermore, we show that the overall sand flux transported by a dune field is smaller than the maximum transport that could be reached in the absence of dunes, i.e., in saltation over the solid ground.

  17. Experimental investigation of strong field trident production

    CERN Document Server

    Esberg, J; Knudsen, H; Thomsen, H D; Uggerhøj, E; Uggerhøj1, U I; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Dalton, M M; Ballestrero, S; Connell, S H

    2010-01-01

    We show by experiment that an electron impinging on an electric field that is of critical magnitude in its rest frame, may produce an electron-positron pair. Our measurements address higher-order QED, using the strong electric fields obtainable along particular crystallographic directions in single crystals. For the amorphous material our data are in good agreement with theory, whereas a discrepancy with theory on the magnitude of the trident enhancement is found in the precisely aligned case where the strong electric field acts.

  18. Book Review: Comparative Education: The Construction of a Field

    Directory of Open Access Journals (Sweden)

    Keith Watson

    2013-04-01

    Full Text Available Comparative Education: The Construction of a Field. By Maria Manzon (2011, 395pp. ISBN: 978-988-1785-26-8, Hong Kong: Springer and the Comparative Education Research Centre, The University of Hong Kong

  19. Comparative studies on the pathogenicity and tissue distribution of three virulence variants of classical swine fever virus, two field isolates and one vaccine strain, with special regard to immunohistochemical investigations

    Directory of Open Access Journals (Sweden)

    Vanderhallen Hans

    2008-09-01

    Full Text Available Abstract Background The aim of this study was to compare the tissue distribution and pathogenicity of three virulence variants of classical swine fever virus (CSFV and to investigate the applicability of various conventional diagnostic procedures. Methods 64 pigs were divided into three groups and infected with the highly virulent isolate ISS/60, the moderately virulent isolate Wingene'93 and the live attenuated vaccine strain Riems, respectively. Clinical signs, gross and histopathological changes were compared in relation to time elapsed post infection. Virus spread in various organs was followed by virus isolation, by immunohistochemistry, applying monoclonal antibodies in a two-step method and by in situ hybridisation using a digoxigenin-labelled riboprobe. Results The tissue distribution data are discussed in details, analyzing the results of the various diagnostic approaches. The comparative studies revealed remarkable differences in the onset of clinical signs as well as in the development of the macro- and microscopical changes, and in the tissue distribution of CSFV in the three experimental groups. Conclusion The present study demonstrates that in the case of highly and moderately virulent virus variants the virulence does not affect the pattern of the viral spread, however, it influences the outcome, the duration and the intensity of the disease. Immunohistochemistry has the advantage to allow the rapid detection and localisation of the virus, especially in cases of early infection, when clinical signs are still absent. Compared to virus isolation, the advantage of this method is that no cell culture facilities are required. Thus, immunohistochemistry provides simple and sensitive tools for the prompt detection of newly emerging variants of CSFV, including the viruses of very mild virulence.

  20. Comparative studies on the pathogenicity and tissue distribution of three virulence variants of classical swine fever virus, two field isolates and one vaccine strain, with special regard to immunohistochemical investigations

    Science.gov (United States)

    Belák, Katinka; Koenen, Frank; Vanderhallen, Hans; Mittelholzer, Christian; Feliziani, Francesco; De Mia, Gian Mario; Belák, Sándor

    2008-01-01

    Background The aim of this study was to compare the tissue distribution and pathogenicity of three virulence variants of classical swine fever virus (CSFV) and to investigate the applicability of various conventional diagnostic procedures. Methods 64 pigs were divided into three groups and infected with the highly virulent isolate ISS/60, the moderately virulent isolate Wingene'93 and the live attenuated vaccine strain Riems, respectively. Clinical signs, gross and histopathological changes were compared in relation to time elapsed post infection. Virus spread in various organs was followed by virus isolation, by immunohistochemistry, applying monoclonal antibodies in a two-step method and by in situ hybridisation using a digoxigenin-labelled riboprobe. Results The tissue distribution data are discussed in details, analyzing the results of the various diagnostic approaches. The comparative studies revealed remarkable differences in the onset of clinical signs as well as in the development of the macro- and microscopical changes, and in the tissue distribution of CSFV in the three experimental groups. Conclusion The present study demonstrates that in the case of highly and moderately virulent virus variants the virulence does not affect the pattern of the viral spread, however, it influences the outcome, the duration and the intensity of the disease. Immunohistochemistry has the advantage to allow the rapid detection and localisation of the virus, especially in cases of early infection, when clinical signs are still absent. Compared to virus isolation, the advantage of this method is that no cell culture facilities are required. Thus, immunohistochemistry provides simple and sensitive tools for the prompt detection of newly emerging variants of CSFV, including the viruses of very mild virulence. PMID:18775072

  1. Comparative Investigation of Shared Filesystems for the LHCb Online Cluster

    Science.gov (United States)

    Vijay Kartik, S.; Neufeld, Niko

    2012-12-01

    This paper describes the investigative study undertaken to evaluate shared filesystem performance and suitability in the LHCb Online environment. Particular focus is given to the measurements and field tests designed and performed on an in-house OpenAFS setup; related comparisons with NFSv4 and GPFS (a clustered filesystem from IBM) are presented. The motivation for the investigation and the test setup arises from the need to serve common user-space like home directories, experiment software and control areas, and clustered log areas. Since the operational requirements on such user-space are stringent in terms of read-write operations (in frequency and access speed) and unobtrusive data relocation, test results are presented with emphasis on file-level performance, stability and “high-availability” of the shared filesystems. Use cases specific to the experiment operation in LHCb, including the specific handling of shared filesystems served to a cluster of 1500 diskless nodes, are described. Issues of prematurely expiring authenticated sessions are explicitly addressed, keeping in mind long-running analysis jobs on the Online cluster. In addition, quantitative test results are also presented with alternatives including NFSv4. Comparative measurements of filesystem performance benchmarks are presented, which are seen to be used as reference for decisions on potential migration of the current storage solution deployed in the LHCb online cluster.

  2. Investigations In Higher Derivative Field Theories

    CERN Document Server

    Paul, Biswajit

    2015-01-01

    Canonical analysis leading to formal quantisation of the higher derivative theories are considered. The first order formalism is adopted where all the configuration space variables along with their higher time derivatives are considered to be independent fields. A systematic algorithm of abstracting the independent gauge symmetries is developed which is an extension of the method developed by Banerjee et al. for the usual first order theories. For the massive relativistic particle model with curvature, we solve the mismatch in the no of independent gauge parameters and no of independent primary fist class constarints. In addition, we show a direct connection between the gauge symmetry and the $W_3$-algebra for the rigid relativistic particle. Also, BRST symmetries for both the massive and massless particle models have been considered and its connection to $W_3$-algebras is demonstrated. The exact mapping of this gauge symmetry is shown with the reparametrisation invariance. Different models from field theory,...

  3. Investigating High Field Gravity using Astrophysical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Elliott D.; /SLAC

    2008-02-01

    The purpose of these lectures is to introduce particle physicists to astrophysical techniques. These techniques can help us understand certain phenomena important to particle physics that are currently impossible to address using standard particle physics experimental techniques. As the subject matter is vast, compromises are necessary in order to convey the central ideas to the reader. Many general references are included for those who want to learn more. The paragraphs below elaborate on the structure of these lectures. I hope this discussion will clarify my motivation and make the lectures easier to follow. The lectures begin with a brief review of more theoretical ideas. First, elements of general relativity are reviewed, concentrating on those aspects that are needed to understand compact stellar objects (white dwarf stars, neutron stars, and black holes). I then review the equations of state of these objects, concentrating on the simplest standard models from astrophysics. After these mathematical preliminaries, Sec. 2(c) discusses 'The End State of Stars'. Most of this section also uses the simplest standard models. However, as these lectures are for particle physicists, I also discuss some of the more recent approaches to the equation of state of very dense compact objects. These particle-physics-motivated equations of state can dramatically change how we view the formation of black holes. Section 3 focuses on the properties of the objects that we want to characterize and measure. X-ray binary systems and Active Galactic Nuclei (AGN) are stressed because the lectures center on understanding very dense stellar objects, black hole candidates (BHCs), and their accompanying high gravitational fields. The use of x-ray timing and gamma-ray experiments is also introduced in this section. Sections 4 and 5 review information from x-ray and gamma-ray experiments. These sections also discuss the current state of the art in x-ray and gamma-ray satellite

  4. Local field enhancement: comparing self-similar and dimer nanoantennas

    CERN Document Server

    Pellegrini, Giovanni; Finazzi, Marco; Biagioni, Paolo

    2016-01-01

    We study the local field enhancement properties of self-similar nanolenses and compare the obtained results with the performance of standard dimer nanoantennas. We report that, despite the additional structural complexity, self-similar nanolenses are unable to provide significant improvements over the field enhancement performance of standard plasmonic dimers.

  5. Comparing sensitivity of ecotoxicological effect endpoints between laboratory and field

    DEFF Research Database (Denmark)

    Selck, H.; Riemann, B.; Christoffersen, K.

    2002-01-01

    multispecies field tests using tributyltin (TBT) and linear alkylbenzene sulfonates (LAS) were compared with published laboratory single-species test results and measured in situ concentrations. Extrapolation methods were evaluated by comparing predicted no-effect concentrations (PNECs), calculated by AF...

  6. Comparative analysis between Payen and Daedalia Planum lava fields

    Science.gov (United States)

    Giacomini, Lorenza; Massironi, Matteo; Pasquarè, Giorgio; Carli, Cristian; Martellato, Elena; Frigeri, Alessandro; Cremonese, Gabriele; Bistacchi, Andrea; Federico, Costanzo

    The Payen volcanic complex is a large Quaternary fissural structure belonging to the back-arc extensional area of the Andes in the Mendoza Province (Argentina). From the eastern portion of this volcanic structure huge pahoehoe lava flows were emitted, extending more than 180 km from the feeding vents. These huge flows propagated over the nearly flat surface of the Pampean foreland (ca 0.3° slope). The very low viscosity of the olivine basalt lavas, coupled with the inflation process are the most probable explanation for their considerable length. In an inflation process a thin viscoelastic crust, produced at an early stage, is later inflated by the underlying fluid core, which remains hot and fluid thanks to the thermal-shield effect of the crust. The inflation shows some typical morphological fingerprints like tumuli, lava lobes, lava rises and lava ridges. In order to compare the morphology of the Argentinean Payen flows with lava flows on Mars, MOLA, THEMIS, MOC, MRO/HIRISE, and MEX/OMEGA data have been analysed, providing a multi-scale characterisation of Martian flows. Mars Global Surveyor/MOLA data were used to investigate the topographic environment over which flows propagated on Mars in order to detect very low angle slopes where possibly inflation processes could have developed. Then Mars Odyssey/THEMIS and Mars Global Surveyor's MOC data were used to detect Martian lava flows with inflation "fingerprints", whereas OMEGA data were used to obtain some inferences about their composition. Finally the MRO/HIRISE images recently acquired, can provide further details and constraints on surface morphologies and lava fronts. All these data were used to analyze Daedalia Planum lava field, at about 300 km southwest of Arsia Mons, and clear morphological similarities with the longest flows of the Payen lava fields were found. These striking morphological analogies suggest that inflation process is quite common also for the Daedalia field. This is also supported by

  7. Comparing investigation of pattern formation in glow and streamer DBD

    Science.gov (United States)

    Li, Ben; Ouyang, Jiting

    2016-11-01

    In this paper, we investigate the behaviors of patterns in dielectric barrier discharge (DBD) in glow and streamer regimes under different operating conditions (driving frequency and voltage) and external electric/magnetic field to explore the similarity and difference of pattern formation. It is found that patterns in both glow and streamer DBDs can be homogenized by decreasing the driving frequency to a low level. But filamentary streamers can still appear at low frequency when the voltage is much higher. With an additional lateral electric field, patterns in both regimes can be homogenized. However, an axial magnetic field makes the glow DBD homogeneous, while the streamer DBD decreases in filamentary size. In both regimes, dynamics and distribution of the space charges, rather than the surface charges, play the predominant role in the formation of DBD patterns. But the surface charges may also play an important role in pattern formation, especially in streamer DBD.

  8. Visual fields of four batoid fishes: a comparative study.

    Science.gov (United States)

    McComb, D Michelle; Kajiura, Stephen M

    2008-02-01

    The visual fields of elasmobranch fishes are not well characterized even though this is a fundamental element of the visual system. The batoid fishes (skates, rays) form a monophyletic clade within the subclass Elasmobranchii and exhibit a broad range of morphologies and corresponding ecologies. We hypothesized that their visual field characteristics would reflect their diverse morphology and ecology. This was tested by quantifying the monocular, binocular and cyclopean horizontal and vertical visual fields of four batoid species (Raja eglanteria, Urobatis jamaicensis, Dasyatis sabina and Rhinoptera bonasus) that encompassed a range from a basal skate to a more derived ray. The horizontal and vertical visual fields differed significantly among species; however, all species possessed horizontal anterior and dorsal binocular overlaps. Urobatis jamaicensis, a small reef-associated stingray, demonstrated a 360 degrees panoramic visual field in the horizontal plane, and R. bonasus, a schooling benthopelagic ray, a 360 degrees panoramic view in the vertical plane. Large anterior binocular overlaps were measured in D. sabina (72 degrees ) and R. bonasus (46 degrees ) but came at the expense of large posterior blind areas. The anterior binocular overlaps in R. eglanteria (28 degrees ) and U. jamaicensis (34 degrees ) were smaller but were coupled with large monocular fields that provided expansive peripheral views. The most phylogenetically basal species, the clearnose skate (Raja eglanteria), had the most reduced visual field in contrast to the more derived ray species. To our knowledge, this study represents the first comparative assessment of visual fields in basal vertebrates.

  9. Experimental Investigation of Integrated Optical Intensive Impulse Electric Field Sensors

    Institute of Scientific and Technical Information of China (English)

    SUN Bao; CHEN Fu-Shen

    2009-01-01

    We design and fabricate an integrated optical electric field sensor with segmented electrode for intensive im-pulse electric field measurement. The integrated optical sensor is based on a Mach-Zehnder interferometer with segmented electrodes. The output/input character of the sensing system is analysed and measured. The max-imal detectable electric field range (-75 kV/m to 245 kV/m) is obtained by analysing the results. As a result, the integrated optics electric field sensing system is suitable for transient intensive electric field measurement investigation.

  10. Different injury pattern in goalkeepers compared to field players

    DEFF Research Database (Denmark)

    Eirale, Cristiano; Tol, Johannes L; Whiteley, Rod

    2014-01-01

    Goalkeepers have a specific physiological and biomechanical profile including hip loading with increased frontal plane kinetics and explosive side jumps. The aim of this study is to analyze the injury incidence in professional goalkeepers and to compare this with field players....

  11. Geologic and field investigations Dorris Dam Modoc National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report presents the results of a. geologic and field investigation of Dorris Dam performed to evaluate embankment and foundation conditions. The work included...

  12. Investigation of Magnetic Field in the Subway Station

    Directory of Open Access Journals (Sweden)

    Ctibor Henzl

    2006-01-01

    Full Text Available Paper deals with computing of magnetic field in the rails surroundings of subway (underground. The calculation of field is made by using of an analytical method in Excel VBA. There is also used commercial FEM software ANSYS and finite element method. Output results of the both methods are finally compared.

  13. Comparing Coronal and Heliospheric Magnetic Fields over Several Solar Cycles

    Science.gov (United States)

    Koskela, J. S.; Virtanen, I. I.; Mursula, K.

    2017-01-01

    Here we use the PFSS model and photospheric data from Wilcox Solar Observatory, SOHO/MDI, SDO/HMI, and SOLIS to compare the coronal field with heliospheric magnetic field measured at 1 au, compiled in the NASA/NSSDC OMNI 2 data set. We calculate their mutual polarity match and the power of the radial decay, p, of the radial field using different source surface distances and different number of harmonic multipoles. We find the average polarity match of 82% for the declining phase, 78%–79% for maxima, 76%–78% for the ascending phase, and 74%–76% for minima. On an average, the source surface of 3.25 RS gives the best polarity match. We also find strong evidence for solar cycle variation of the optimal source surface distance, with highest values (3.3 RS) during solar minima and lowest values (2.6 RS–2.7 RS) during the other three solar cycle phases. Raising the number of harmonic terms beyond 2 rarely improves the polarity match, showing that the structure of the HMF at 1 au is most of the time rather simple. All four data sets yield fairly similar polarity matches. Thus, polarity comparison is not affected by photospheric field scaling, unlike comparisons of the field intensity.

  14. Communication linguistique: Etude comparative faite sur le terrain (Linguistic Communication: A Comparative Field Study).

    Science.gov (United States)

    Piron, Claude

    2002-01-01

    Compares the four international systems of linguistic communication used in the field (systems used in the United Nations, multinationals, the European Union, and Esperanto organizations) on select criteria (e.g., previous government investment). Discusses research that shows unilingual systems (English used alone, Esperanto) are those that…

  15. Rapid core field variations during the satellite era: Investigations using stochastic process based field models

    DEFF Research Database (Denmark)

    Finlay, Chris; Olsen, Nils; Gillet, Nicolas

    We present a new ensemble of time-dependent magnetic field models constructed from satellite and observatory data spanning 1997-2013 that are compatible with prior information concerning the temporal spectrum of core field variations. These models allow sharper field changes compared to traditional....... We report spherical harmonic spectra, comparisons to observatory monthly means, and maps of the radial field at the core-mantle boundary, from the resulting ensemble of core field models. We find that inter-annual fluctuations in the external field (for example related to high solar-driven activity...

  16. Field Investigation of High Performance Pavements in Virginia

    OpenAIRE

    2005-01-01

    This study evaluated 18 pavement sections located in high-traffic highways in Virginia to find a premium pavement design with a life span of 40 years or more using current and past field experience. The selected pavement sections were thought to perform well. Eight flexible pavements, six composite pavements, two continuously reinforced concrete pavements, and two jointed plain concrete pavements were investigated. Field testing consisted of (1) falling weight deflectometer (FWD) testing to a...

  17. Comparative review of the investigation and confiscation of criminal assets

    Directory of Open Access Journals (Sweden)

    Lajić Oliver

    2012-01-01

    Full Text Available In introduction author points to the necessity of adopting the institute of confiscation of criminal assets, supported by international experience, primarily due to the weakness of previously known institute confiscation of the proceeds of crime (for which the offender is being tried, showed in front of the phenomenon of organized crime. In doing so, he analyzes the modalities of confiscation of criminal origin present in modern legal systems and emphasizes the required standard of proof, as one of the key factors of their particularity. The following is a comparative review of the system for investigating and confiscation of criminal assets in Italy, Great Britain, Ireland, the Netherlands, Germany, France and the United States. There are emphasized the normative elements which affect to scope of application of this institute, especially in light of its connection to the criminal proceedings, as well as jurisdiction to realization of the investigation process and procedure of confiscation. In the final part, the author concludes that appropriate social and institutional responses are very important for the effective fight against crime, every time if there is a suspicion about illegally acquired wealth. In doing so, particular attention arouses organized crime, particularly in the light of contemporary global trends, which, unfortunately, significantly affect the possibility of the development of organized crime, and development and/or covering up its financial component. In this sense, the author emphasizes that the basic characteristics of the system for investigation and confiscation of criminal assets connected to the criminal proceedings, which are used in developed European countries and the United States: (1 changed the rules of evidence, which means less convenient role of suspects, (2 the application of this mechanism to a limited number of crimes, which often includes drug trafficking and other serious crimes or organized crime, and

  18. Comparative anthelmintic activity investigation of selected ethno-medicinal weeds

    Science.gov (United States)

    Pueblos, Kirstin Rhys S.; Bajalla, Mark; Pacheco, Dixie; Ganot, Sheila; Paig, Daisy; Tapales, Radyn; Lagare, Jeanne; Quimque, Mark Tristan J.

    2017-01-01

    Helminth infections are one of the seriously neglected potent diseases in many parts of the world. The problems of parasitic helminthes becoming resistant to currently available anthelmintic drugs pose a challenge for the search - relying on natural products - for new and better anthelmintics. In this paper, four abundant Philippine weeds: Chrysopogon aciculatus Trin. Cyperus brevifolius Rottb., Ruellia tuberosa Linn. and Saccharum spontaneum Linn. were investigated for their anthelmintic activities to establish basis of their folkloric claim. The hexane-soluble and chloroform-soluble extracts were obtained through sequential solvent partitioning of the crude ethanolic extract of the air-dried aerial part of each plant sample. Meanwhile, the decoction was obtained from fresh aerial part of the plant samples. All extracts were then subjected to in vitro anthelmintic screening at different concentration as per method of Ghosh, et al. against African nightcrawler earthworms (Eudrillus euginiae) in which the activity of the extracts was determined by correlation with time. The anthelmintic bioassay results revealed a dose-dependent toxicity relationship. It indicated relatively low anthelmintic activities of the decoction of the four plant samples as compared to their corresponding crude ethanol extracts. Among the crude ethanol extracts, C. brevifolius (CBE) gave fastest time to bring about paralysis and death to the test organisms at all concentrations tested. For the hexane extracts, R. tuberosa (RTH) gave better activity among other plant samples. Lastly, among the chloroform-soluble extracts, both that of C. brevifolius (CBC) and R. tuberosa (RTC) comparably showed strongest anthelmintic activities at all tested concentrations, thus, exhibited best anthelmintic activity that is remarkably comparable to the positive control, Mebendazole at the highest concentration tested. In fact, CBC and RTC showed highest anthelmintic potential compared to all extracts tested in

  19. Comparative Geometrical Investigations of Hand-Held Scanning Systems

    Science.gov (United States)

    Kersten, T. P.; Przybilla, H.-J.; Lindstaedt, M.; Tschirschwitz, F.; Misgaiski-Hass, M.

    2016-06-01

    An increasing number of hand-held scanning systems by different manufacturers are becoming available on the market. However, their geometrical performance is little-known to many users. Therefore the Laboratory for Photogrammetry & Laser Scanning of the HafenCity University Hamburg has carried out geometrical accuracy tests with the following systems in co-operation with the Bochum University of Applied Sciences (Laboratory for Photogrammetry) as well as the Humboldt University in Berlin (Institute for Computer Science): DOTProduct DPI-7, Artec Spider, Mantis Vision F5 SR, Kinect v1 + v2, Structure Sensor and Google's Project Tango. In the framework of these comparative investigations geometrically stable reference bodies were used. The appropriate reference data were acquired by measurement with two structured light projection systems (AICON smartSCAN and GOM ATOS I 2M). The comprehensive test results of the different test scenarios are presented and critically discussed in this contribution.

  20. Experiments to investigate particulate materials in reduced gravity fields

    Science.gov (United States)

    Bowden, M.; Eden, H. F.; Felsenthal, P.; Glaser, P. E.; Wechsler, A. E.

    1967-01-01

    Study investigates agglomeration and macroscopic behavior in reduced gravity fields of particles of known properties by measuring and correlating thermal and acoustical properties of particulate materials. Experiment evaluations provide a basis for a particle behavior theory and measure bulk properties of particulate materials in reduced gravity.

  1. Asteroseismic Investigation of Known Planet Hosts in the Kepler Field

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jørgen; Kjeldsen, Hans; Brown, T. M.

    2010-01-01

    Asteroseismic Investigation of Known Planet Hosts in the Kepler Field .a{background-color: #ffff88}.h{background-color: #ffff00}.b{background-color: #ccccff}.i{background-color: #3333ff}.c{background-color: #ffcccc}.j{background-color: #ff3333}.d{background-color: #bbffff}.k{background-color: #00...

  2. Comparative investigation on HVOF sprayed carbide-based coatings

    Science.gov (United States)

    Xie, Mingxiang; Zhang, Shihong; Li, Mingxi

    2013-05-01

    In this work, WC-17Co, WC-10Co-4Cr, WC-12Co and Cr3C2-25NiCr coatings were deposited on stainless steel using WOKAStar-640 HVOF spraying system. Three WC-based coatings were studied and compared with a chromium carbide-based coating. The microstructure, porosity, micro-hardness, indentation fracture toughness and adhesion strength of the coatings were investigated. The wear test was done by using silica grits as abrasive medium using a load of 20 N. The result shows that HVOF sprayed carbide-based coating possesses low porosity, high micro-hardness and high adhesion strength. Three WC-based coatings have higher micro-hardness and indentation fracture toughness compared to the Cr3C2-25NiCr coating. HVOF sprayed carbide coating has good wear resistance under 500 °C. The decarburization of WC-based coating has great effect on coating wear resistance. In addition, WC-17Co coating has best wear resistance.

  3. Radiological field exercises for forensic investigators. Technical memorandum

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, C.L. [Defence R and D Canada (DRDC), Ottawa, Ontario (Canada); Clement, C.; Estan, D. [Canadian Nuclear Safety Commission, Ottawa, Ontario (Canada); McDiarmid, C.; Tessier, M. [Royal Canadian Mounted Police (RCMP), Ottawa, Ontario (Canada)

    2006-06-15

    A series of tabletop and field exercises were designed and executed to test traditional forensic investigation procedures in a crime scene with radioactive material present. This allowed for specific training needs of forensic identification specialists to be identified and revised procedures to be drafted. Two scenarios were exercised, first as tabletop discussions with the Royal Canadian Mounted Police (RCMP), the Canadian Nuclear Safety Commission (CNSC), and DRDC Ottawa, and then as field exercises with the participation of the RCMP and Ottawa Police Services (OPS) forensic investigators. These exercises produced a number of lessons learned with regard to protocols for forensic investigators and led to the development of a one-page fact sheet on performing forensic identification tasks in a radiation environment. (author)

  4. Experimental and field investigations on uprooting of riparian vegetation

    Science.gov (United States)

    Calvani, Giulio; Francalanci, Simona; Solari, Luca; Gumiero, Bruna

    2017-04-01

    The morphology of a river reach is the result of many processes involving the motion of sediment (erosion, transport and deposition), the hydrological regime and the development and growth of vegetation. River evolution in the presence of vegetation depends on establishment of pioneer woody riparian seedlings on bars, and consequently on either their survival or death. Flooding events can cause young vegetation mortality by uprooting (Corenblit et al., 2007). These processes, despite their important implications on river morphodynamics, have been poorly investigated in the past. Most of previous research focused on the mechanism of root breakage and on measuring the vegetation resistance to uprooting in the vertical direction, while few works considered the effect of flow direction on the uprooting process (Bywater-Reyes et al., 2015). In this work, we focused on vegetation uprooting due to flow and to bed erosion. We considered two different types of vegetation: Avena Sativa, grown from seeds in external boxes, was used to investigate instantaneous uprooting, and Salix Purpurea, collected in the field, for delayed uprooting (namely type I and type II mechanisms, according to Edmaier et al., 2011). The experiments were carried out in a 5 m long flume in the Hydraulic Laboratory in Florence. A 2 m long mobile bed was build inside the flume, and vegetation was arranged according to several configurations on it. Both types of vegetation were subject to constant discharges to investigate the effects of a general bed degradation in modifying the occurrence of uprooting. We also performed some experiments with Avena Sativa located in a fixed bed and subjected to an increasing flow discharge in order to simulate instantaneous uprooting due to the action of hydrodynamic forces. We measured flow velocity, flow discharge and water depth and characterized vegetation by stem and root diameter, height and root length. The experimental results have been interpreted in terms of a

  5. Effects of persistent insecticides on beneficial soil arthropod in conventional fields compared to organic fields, puducherry.

    Science.gov (United States)

    Anbarashan, Padmavathy; Gopalswamy, Poyyamoli

    2013-07-15

    The usage of synthetic fertilizers/insecticides in conventional farming has dramatically increased over the past decades. The aim of the study was to compare the effects of bio-pesticides and insecticides/pesticides on selected beneficial non targeted arthropods. Orders Collembola, Arachinida/Opiliones, Oribatida and Coleoptera were the main groups of arthropods found in the organic fields and Coleoptera, Oribatida, Gamasida and Collembola in conventional fields. Pesticides/insecticides had a significant effect on non-targeted arthropods order- Collembola, Arachinida/Opiliones, Hymenoptera and Thysonoptera were suppressed after pesticides/insecticides spraying. Bio-insecticides in organic fields had a non-significant effect on non targeted species and they started to increase in abundance after 7 days of spraying, whereas insecticide treatment in conventional fields had a significant long-term effect on non targeted arthropods and short term effect on pests/insects, it started to increase after 21 days of the spraying. These results indicate that insecticide treatment kept non targeted arthropods at low abundance. In conclusion, organic farming does not significantly affected the beneficial-non targeted arthropods biodiversity, whereas preventive insecticide application in conventional fields had significant negative effects on beneficial non targeted arthropods. Therefore, conventional farmers should restrict insecticide applications, unless pest densities reach the thresholds and more desirably can switch to organic farming practices.

  6. Field investigation to assess nutrient emission from paddy field to surface water in river catchment

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2015-04-01

    In order to maintain good river environment, it is remarkably important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. Our former research dealing with nutrient emission analysis in the Tone River basin area in Japan, in addition to urban and industrial waste water, nutrient emission from agricultural activity is dominant pollution source into the river system. Japanese style agriculture produces large amount of rice and paddy field occupies large areas in Japanese river basin areas. While paddy field can deteriorate river water quality by outflow of fertilizer, it is also suggested that paddy field has water purification function. As we carried out investigation in the Tone River Basin area, data were obtained which dissolved nitrogen concentration is lower in discharging water from paddy field than inflowing water into the field. Regarding to nutrient emission impact from paddy field, sufficient data are required to discuss quantitatively seasonal change of material behavior including flooding season and dry season, difference of climate condition, soil type, and rice species, to evaluate year round comprehensive impact from paddy field to the river system. In this research, field survey in paddy field and data collection relating rice production were carried out as a preliminary investigation to assess how Japanese style paddy field contributes year round on surface water quality. Study sites are three paddy fields located in upper reach of the Tone River basin area. The fields are flooded from June to September. In 2014, field investigations were carried out three times in flooding period and twice in dry period. To understand characteristics of each paddy field and seasonal tendency accompanying weather of agricultural event, short term investigations were conducted and we prepare for further long term investigation. Each study site has irrigation water inflow and outflow. Two sites have tile drainage system under the field and

  7. Investigations of deep resistivity structures at the Wairakei geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Bibby, Hugh M.; Risk, George F.; Grant Caldwell, T.; Heise, Wiebke [GNS Science, P.O. Box 30368, Lower Hutt (New Zealand)

    2009-03-15

    the 21st century is magnetotellurics (MT), which determines the resistivity of the ground from the currents induced in the earth by natural variations of the earth's magnetic field. While MT has not yet been applied within the Wairakei field, the method has been used to investigate the setting of the geothermal systems of the Taupo Volcanic Zone. These data reveal key elements of the deep source of heat, including the presence of a small fraction of connected molten rock at a depth of about 10 km and the possible pooling of magma at about 15 km. (author)

  8. Investigation of field temperature in moulds of foamed plaster

    Directory of Open Access Journals (Sweden)

    M. Pawlak

    2007-12-01

    Full Text Available Plaster moulds used in precision foundry are characterized by a very low permeability which, in the case of classic plaster moulds, equals to about 0,01÷0,02 m2/(MPa·s. One of the most effective methods for increasing the permeability is a foaming treatment. Another characteristic feature of plaster is its very good insulating power which has influence on the process of solidification and cooling of a cast and also on a knock-out property. This insulating power is a function of thermophysical properties of plaster which, in turn, depend mainly on the mineralogical composition of the mould material, its bulk density as well as on the temperature of the pouring alloy. In the case of a foamed plaster mould an increase of the degree of foaming increases its porosity which causes a change in its thermophysical properties, thereby increasing susceptibility of the mass to overheating. The susceptibility of the plaster layer surrounding the cast to overheating is favorable because it makes it easier to knock-out of the cast by immersing the hot mould in cold water. Thermal and phase tensions that are created during this process cause fast destruction of plaster. This paper describes our investigations aimed at the determination of the dependence of the mould temperature field on the time of the cast stay in the mould, as recorded in a process of an unsteady heat flow. The determined data were planned to be used for estimation of the technological properties of the plaster mould. The tests were carried out using the plaster α-Supraduro and Alkanol XC (foaming agent. The test mould had a diameter of Ø 120 mm with centrally situated mould cavity of Ø 30 mm. Plaster moulds with a degree of foaming 20; 32,5 and 45% and comparatively from non-foaming plaster were tested and their temperatures were measured at the distance x=2; 9; 21; 25;27; 30 mm from the mould cavity within 25 min. Analysis of the results leads to the conclusion, that the highest

  9. Comparative Administrative Law: Outlining a Field of Study

    Directory of Open Access Journals (Sweden)

    Susan Rose-Ackerman

    2010-10-01

    Full Text Available Comparative administrative law is emerging as a distinct field of inquiry after a period of neglect. To demonstrate this claim, the authors summarize their edited volume on the topic – a collection that aims to stimulate research across legal systems and scholarly disciplines. After a set of historical reflections, the authors consider key topics at the intersection of administrative and constitutional law, including the contested issue of administrative independence. Two further sections highlight tensions between expertise and accountability, drawing insights from economics and political science. The essay then considers the changing boundaries of the administrative state – both the public–private distinction and the links between domestic and transnational regulatory bodies, such as the European Union. The essay concludes with reflections on a core concern of administrative law: the way individuals and organizations across different systems test and challenge the legitimacy of public authority. Le droit administratif comparé est en train de se manifester comme domaine d’étude distinct suite à une période pendant laquelle il a été négligé. Pour démontrer cette affirmation, les auteurs présentent un sommaire du volume à ce sujet dont ils dirigent la publication – une collection qui vise à stimuler la recherche au sein de divers systèmes juridiques et diverses disciplines d’érudition. Après une série de réflexions historiques, les auteurs traitent de questions–clés qui relèvent en même temps du droit administratif et du droit constitutionnel, y compris la question controversée de l’indépendance administrative. Deux autres sections mettent en lumière des tensions entre l’expertise et l’obligation de rendre compte, puisant dans les sciences économique et politique. L’article traite ensuite des limites changeantes de l’état administratif – d’une part, quant à la distinction public–privé et d

  10. Shemya AFB, Alaska 1992 IRP field investigation report

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-01

    The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force's Installation Restoration Program (IRP). Field investigations were performed in 1992 to obtain the information needed to assess what future actions will need to be carried out at each site. The island's drinking water supply was also investigated. Activities completed at 10 selected sites included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. Geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal to be avoided during drilling activities. This report, appendices B, C, and D contains information on the following: geophysical contour maps and profile plots; human health risk assessment; and ecological risk assessment.

  11. Shemya AFB, Alaska 1992 IRP field investigation report

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-01

    The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force's Installation Restoration Program (IRP). Field investigations were performed in 1992 to obtain the information needed to assess what future actions will need to be carried out at each site. The island's drinking water supply was also investigated. Activities completed at 10 selected sites included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. In addition, geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal, to be avoided during drilling activities. This report contains appendices E and F with information on the following: soil boring logs, and data validation of samples analyzed.

  12. FINESSE: Field Investigations to Enable Solar System Science and Exploration

    Science.gov (United States)

    Heldmann, Jennifer; Lim, Darlene; Colaprete, Anthony

    2015-01-01

    The FINESSE (Field Investigations to Enable Solar System Science and Exploration) team is focused on a science and exploration field-based research program aimed at generating strategic knowledge in preparation for the human and robotic exploration of the Moon, near-Earth asteroids (NEAs) and Phobos and Deimos. We follow the philosophy that "science enables exploration and exploration enables science." 1) FINESSE Science: Understand the effects of volcanism and impacts as dominant planetary processes on the Moon, NEAs, and Phobos & Deimos. 2) FINESSE Exploration: Understand which exploration concepts of operations (ConOps) and capabilities enable and enhance scientific return. To accomplish these objectives, we are conducting an integrated research program focused on scientifically-driven field exploration at Craters of the Moon National Monument and Preserve in Idaho and at the West Clearwater Lake Impact Structure in northern Canada. Field deployments aimed at reconnaissance geology and data acquisition were conducted in 2014 at Craters of the Moon National Monument and Preserve. Targets for data acquisition included selected sites at Kings Bowl eruptive fissure, lava field and blowout crater, Inferno Chasm vent and outflow channel, North Crater lava flow and Highway lava flow. Field investigation included (1) differential GPS (dGPS) measurements of lava flows, channels (and ejecta block at Kings Bowl); (2) LiDAR imaging of lava flow margins, surfaces and other selected features; (3) digital photographic documentation; (4) sampling for geochemical and petrographic analysis; (5) UAV aerial imagery of Kings Bowl and Inferno Chasm features; and (6) geologic assessment of targets and potential new targets. Over the course of the 5-week field FINESSE campaign to the West Clearwater Impact Structure (WCIS) in 2014, the team focused on several WCIS research topics, including impactites, central uplift formation, the impact-generated hydrothermal system, multichronometer

  13. Systematic comparative evaluation of methods for investigating the TCRβ repertoire

    DEFF Research Database (Denmark)

    Liu, Xiao; Zhang, Wei; Zeng, Xiaojing;

    2016-01-01

    advantages and disadvantages; however, a systematic evaluation and direct comparison of them would benefit researchers in the selection of the most suitable method. In this study, we used both pooled control plasmids and spiked-in cells to benchmark the MPCR bias. RNA from three healthy donors...... was subsequently processed with the two methods to perform a comparative evaluation of the TCR β chain sequences. Both approaches demonstrated high reproducibility (R2 = 0.9958 and 0.9878, respectively). No differences in gene usage were identified for most V/J genes (>60%), and an average of 52.03% of the CDR3...... variability was smaller compared with the biological variability. Through direct comparison, these findings provide novel insights into the two experimental methods, which will prove to be valuable in immune repertoire research and its interpretation....

  14. Systematic Comparative Evaluation of Methods for Investigating the TCRβ Repertoire.

    Science.gov (United States)

    Liu, Xiao; Zhang, Wei; Zeng, Xiaojing; Zhang, Ruifang; Du, Yuanping; Hong, Xueyu; Cao, Hongzhi; Su, Zheng; Wang, Changxi; Wu, Jinghua; Nie, Chao; Xu, Xun; Kristiansen, Karsten

    2016-01-01

    High-throughput sequencing has recently been applied to profile the high diversity of antibodyome/B cell receptors (BCRs) and T cell receptors (TCRs) among immune cells. To date, Multiplex PCR (MPCR) and 5'RACE are predominately used to enrich rearranged BCRs and TCRs. Both approaches have advantages and disadvantages; however, a systematic evaluation and direct comparison of them would benefit researchers in the selection of the most suitable method. In this study, we used both pooled control plasmids and spiked-in cells to benchmark the MPCR bias. RNA from three healthy donors was subsequently processed with the two methods to perform a comparative evaluation of the TCR β chain sequences. Both approaches demonstrated high reproducibility (R2 = 0.9958 and 0.9878, respectively). No differences in gene usage were identified for most V/J genes (>60%), and an average of 52.03% of the CDR3 amino acid sequences overlapped. MPCR exhibited a certain degree of bias, in which the usage of several genes deviated from 5'RACE, and some V-J pairings were lost. In contrast, there was a smaller rate of effective data from 5'RACE (11.25% less compared with MPCR). Nevertheless, the methodological variability was smaller compared with the biological variability. Through direct comparison, these findings provide novel insights into the two experimental methods, which will prove to be valuable in immune repertoire research and its interpretation.

  15. Systematic Comparative Evaluation of Methods for Investigating the TCRβ Repertoire.

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    Full Text Available High-throughput sequencing has recently been applied to profile the high diversity of antibodyome/B cell receptors (BCRs and T cell receptors (TCRs among immune cells. To date, Multiplex PCR (MPCR and 5'RACE are predominately used to enrich rearranged BCRs and TCRs. Both approaches have advantages and disadvantages; however, a systematic evaluation and direct comparison of them would benefit researchers in the selection of the most suitable method. In this study, we used both pooled control plasmids and spiked-in cells to benchmark the MPCR bias. RNA from three healthy donors was subsequently processed with the two methods to perform a comparative evaluation of the TCR β chain sequences. Both approaches demonstrated high reproducibility (R2 = 0.9958 and 0.9878, respectively. No differences in gene usage were identified for most V/J genes (>60%, and an average of 52.03% of the CDR3 amino acid sequences overlapped. MPCR exhibited a certain degree of bias, in which the usage of several genes deviated from 5'RACE, and some V-J pairings were lost. In contrast, there was a smaller rate of effective data from 5'RACE (11.25% less compared with MPCR. Nevertheless, the methodological variability was smaller compared with the biological variability. Through direct comparison, these findings provide novel insights into the two experimental methods, which will prove to be valuable in immune repertoire research and its interpretation.

  16. Systematic comparative evaluation of methods for investigating the TCRβ repertoire

    DEFF Research Database (Denmark)

    Liu, Xiao; Zhang, Wei; Zeng, Xiaojing

    2016-01-01

    advantages and disadvantages; however, a systematic evaluation and direct comparison of them would benefit researchers in the selection of the most suitable method. In this study, we used both pooled control plasmids and spiked-in cells to benchmark the MPCR bias. RNA from three healthy donors...... was subsequently processed with the two methods to perform a comparative evaluation of the TCR β chain sequences. Both approaches demonstrated high reproducibility (R2 = 0.9958 and 0.9878, respectively). No differences in gene usage were identified for most V/J genes (>60%), and an average of 52.03% of the CDR3...

  17. Comparative investigations of the desensitising efficacy of a new dentifrice.

    Science.gov (United States)

    Sowinski, J; Ayad, F; Petrone, M; DeVizio, W; Volpe, A; Ellwood, R; Davies, R

    2001-11-01

    In two clinical trials of 8 weeks duration, the ability of a new dentifrice, containing potassium nitrate, stannous fluoride and sodium fluoride to reduce dentine hypersensitivity was compared with either a non-desensitising fluoride dentifrice or a commercially available desensitising dentifrice (Sensodyne F) to reduce dentine hypersensitivity. In both studies, the participants had to have at least two sensitive root surfaces. Subjects were stratified by baseline tactile and air blast sensitivity scores and the number of sensitive teeth and randomly allocated to 2 balanced groups. In the first study (N=81) the new dentifrice was compared with a fluoride dentifrice and in the second study (N=105) with Sensodyne F. Participants were requested to brush with their assigned dentifrice twice a day for one minute. At 4 and 8 weeks the sensitive teeth were again examined and their tactile and air blast sensitivity scores recorded. In study 1, the group using the new dentifrice tolerated greater pressure after 4 (34.9 g) and 8 weeks (38.4 g) than the group using the fluoride dentifrice (22.9 g and 19.0 g, respectively). These differences were statistically significant (pSensodyne F (27.8 g and 33.2 g, respectively). These differences were statistically significant (pSensodyne F (1.90 and 1.57) (pSensodyne F).

  18. Experimental Investigation of Pool Boiling Heat Transfer Enhancement in Microgravity in the Presence of Electric Fields

    Science.gov (United States)

    Herman, C.

    2000-01-01

    The research carried out in the Heat Transfer Laboratory of the Johns Hopkins University was motivated by previous studies indicating that in terrestrial applications nucleate boiling heat transfer can be increased by a factor of 50 when compared to values obtained for the same system without electric fields. Imposing an external electric field holds the promise to improve pool boiling heat transfer in low gravity, since a phase separation force other than gravity is introduced. The influence of electric fields on bubble formation has been investigated both experimentally and theoretically.

  19. Continuous field investigation assessing nitrogen and phosphorus emission from irrigated paddy field

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2016-04-01

    In order to maintain good river environment, it is very important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. Other than urban and industrial waste water, nutrient emission from agricultural activity is dominant pollution source into the river system. Rice is one of the staple products of Asia and paddy field occupies large areas in Asian countries. Rice is also widely cultivated in Japan. Paddy field occupies large areas in Japanese river basin areas. While paddy field can deteriorate river water quality by discharging fertilizer, it is also suggested that paddy field has water purification function. Regarding to nutrient emission from paddy field, existing monitored data are insufficient so as to discuss quantitatively seasonal change of material behavior including flooding season and dry season and to evaluate year round comprehensive impact from paddy field to the river system. These are not sufficient data for discussion of material flow and emission impact quantitatively as well as qualitatively. We have carried out field investigation in paddy fields in middle reach of the Tone River Basin. The aim of the survey is understanding of water and nutrient balance in paddy field. In order to understand emission impact from paddy field to river system, all input and output flow are measured to calculate nutrient balance in paddy field. Therefore we observed quantity of water flow into/from paddy field, water quality change of inflow and outflow during flooding season. We set focus on a monitoring paddy field IM, and monitored continuously water and nutrient behavior. By measuring water quality and flow rate of inflow, outflow, infiltrating water, ground water and depth of flooding water, we tried to quantitatively understand N and P cycle around paddy field including seasonal tendency, change accompanying with rainy events and occurred according to agricultural events like fertilization. At the beginning of flooding season, we

  20. A comparative investigation of seven indirect attitude measures.

    Science.gov (United States)

    Bar-Anan, Yoav; Nosek, Brian A

    2014-09-01

    We compared the psychometric qualities of seven indirect attitude measures across three attitude domains (race, politics, and self-esteem) with a large sample (N = 23,413). We compared the measures on internal consistency, sensitivity to known effects, relationships with indirect and direct measures of the same topic, the reliability and validity of single-category attitude measurement, their ability to detect meaningful variance among people with nonextreme attitudes, and their robustness to the exclusion of misbehaving or well-behaving participants. All seven indirect measures correlated with each other and with direct measures of the same topic. These relations were always weak for self-esteem, moderate for race, and strong for politics. This pattern suggests that some of the sources of variation in the reliability and predictive validity of the indirect measures is a function of the concepts rather than the methods. The Implicit Association Test (IAT) and Brief IAT (BIAT) showed the best overall psychometric quality, followed by the Go–No-Go association task, Single-Target IAT (ST-IAT), Affective Misattribution Procedure (AMP), Sorting Paired Features task, and Evaluative Priming. The AMP showed a steep decline in its psychometric qualities when people with extreme attitude scores were removed. Single-category attitude scores computed for the IAT and BIAT showed good relationships with other attitude measures but no evidence of discriminant validity between paired categories. The other measures, especially the AMP and ST-IAT, showed better evidence for discriminant validity. These results inform us on the validity of the measures as attitude assessments, but do not speak to the implicitness of the measured constructs.

  1. Field investigation on Salixpsammophila plant morphology and airflow structure

    Institute of Scientific and Technical Information of China (English)

    Wang Lei; Wang Zhi; Liu Lianyou; Hasi Eerdon; Sun Bingyan; Tang Yan

    2006-01-01

    The field investigation was undertaken to determin the characteristics of Salix psammophila plant morphdogy and airflow structure of single-line S.psammophila on the southern edge of the Mu Su sandland.The results showed that artificially cultivated single-line S.psammophila could accumulate sand because the plant decreased the windward and leeward wind velocity.There was a significant correlation (R = 0.696) between accumulated sand volume (V2) and plant volume (V1).The wind velocity was 6 m/s at a 4 m height of single-line S.psammophilahedge row.The wind velocity decreased at 3 H windward and increased at 2 H to windward.The wind velocity then steeply decreased to leeward and reached its lowest value at 1 H to leeward and gradually recovered to the open field velocity.The protection distance of the single-line S.psammophila was about 17 H' and the effective protection distance was aboui 13 H'.Single-line S.psammophila had few effects on the wind velocity when the wind was above the plant height.

  2. Far-field and near-field investigation of plasmonic-photonic hybrid laser mode

    CERN Document Server

    Zhang, Taiping; Callard, Ségolène; jamois, Cecile; Letartre, Xavier; Chevalier, Celine; Rojo-Romeo, Pedro; Devif, Brice; Viktorovitch, Pierre

    2014-01-01

    We report an approach to achieve this goal via build a plasmonic-dielectric photonic hybrid system. We induce a defect mode based photonic crystal (PC) cavity to work as a intermedium storage as well as a near-field light source to excite a plasmonic nanoantenna (NA). In this way, a plasmonic-photonic nano-laser source is created in present experiment. The coupling condition between the two elements is investigated in far-field and near-field level. We found that the NA reduces the Q-factor of the PC-cavity. Meanwhile, the NA concentrates and enhances the laser emission of the PC-cavity. This novel hybrid dielectric-plasmonic structure may open a new avenue in the generation of nano-light sources, which can be applied in areas such as optical information storage, non-linear optics, optical trapping and detection, integrated optics, etc.

  3. The Value in Comparing Organizational Fields and Forms

    DEFF Research Database (Denmark)

    2016-01-01

    specific types of organizational forms – hospitals and universities. In so doing, we take a broader perspective encompassing various conceptual and theoretical points of departure emanating from, mostly, the institutional literature in the social sciences (and its various perspectives), but also from...... public policy and administration literatures – of relevance to scholars and the communities of practice working within either field. In this introductory paper to the volume, we provide a brief overview of developments across the two organizational fields and illuminate on the most important scholarly...

  4. Comparative study between toroidal coordinates and the magnetic dipole field

    CERN Document Server

    Chávez-Alarcón, Esteban

    2012-01-01

    There is a similar behaviour between the toroidal coordinates and the dipole magnetic field produced by a circular loop. In this work we evaluate up to what extent the former can be used as a representation of the latter. While the tori in the toroidal coordinates have circular cross sections, those of the circular loop magnetic field are nearly elliptical ovoids, but they are very similar for large aspect ratios.The centres of the latter displace from the axis faster than the former. By making a comparison between tori of similar aspect ratios, we find quantitative criteria to evaluate the accuracy of the approximation.

  5. Investigation of male infertility using quantitative comparative proteomics.

    Science.gov (United States)

    Légaré, Christine; Droit, Arnaud; Fournier, Frédéric; Bourassa, Sylvie; Force, André; Cloutier, Francine; Tremblay, Roland; Sullivan, Robert

    2014-12-05

    Male factors account for 40% of infertility cases. The identification of differentially expressed proteins on spermatozoa from fertile and infertile men can help in the elucidation of the molecular basis of male infertility. The aim of this study was to compare sperm proteomes from 3 different groups: fertile men, normozoospermic men consulting for infertility, and normozoospermic men with an impaired capacity for fertilization (IVF-failure). We used differential proteomics with isobaric tags for relative and absolute quantitation (iTRAQ) labeling, and LC-MS analysis to identify proteins that are differentially expressed. A total of 348 unique proteins were identified and quantified. The analysis identified 33 proteins that were differentially expressed in the IVF-failure group vs the fertile group. Comparison of the infertile and fertile groups revealed that 18 proteins appeared to be differentially expressed. Four proteins were similarly altered in the IVF-failure and infertile groups: semenogelin 1 (SEMG1), prolactin-induced protein (PIP), glyceraldehyde-3-phosphate dehydrogenase (GAPDHS), and phosphoglycerate kinase 2 (PGK2). These protein markers were selected for validation using multiple reactions monitoring mass spectrometry (MRM-MS) and further confirmed by Western blot analysis. Overall, these results suggest that a panel of proteins may be used as biomarkers for future studies of infertility.

  6. COMPARING FIELD PERFORMANCES OF DENUDER TECHNIQUES IN THE HIGH ARCTIC

    Science.gov (United States)

    A field evaluation between two annular denuder system configurations was conducted during the spring of 2003 in the marine Arctic (Ny-Ålesund, Svalbard). The IIA annular denuder system (ADS) employs a series of five single channel annular denuders, a cyclone and a filter pack to ...

  7. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Remedial investigation results

    Energy Technology Data Exchange (ETDEWEB)

    Yuen, C. R.; Martino, L. E.; Biang, R. P.; Chang, Y. S.; Dolak, D.; Van Lonkhuyzen, R. A.; Patton, T. L.; Prasad, S.; Quinn, J.; Rosenblatt, D. H.; Vercellone, J.; Wang, Y. Y.

    2000-03-14

    This report presents the results of the remedial investigation (RI) conducted at J-Field in the Edgewood Area of Aberdeen Proving Ground (APG), a U.S. Army installation located in Harford County, Maryland. Since 1917, activities in the Edgewood Area have included the development, manufacture, and testing of chemical agents and munitions and the subsequent destruction of these materials at J-Field by open burning and open detonation. These activities have raised concerns about environmental contamination at J-Field. This RI was conducted by the Environmental Conservation and Restoration Division, Directorate of Safety, Health and Environmental Division of APG, pursuant to requirements outlined under the Comprehensive Environmental Response, Compensation, and Liability Act, as amended (CERCLA). The RI was accomplished according to the procedures developed by the U.S. Environmental Protection Agency (EPA 1988). The RI provides a comprehensive evaluation of the site conditions, nature of contaminants present, extent of contamination, potential release mechanisms and migration pathways, affected populations, and risks to human health and the environment. This information will be used as the basis for the design and implementation of remedial actions to be performed during the remedial action phase, which will follow the feasibility study (FS) for J-Field.

  8. A field investigation and numerical simulation of coastal fog

    Science.gov (United States)

    Mack, E. J.; Eadie, W. J.; Rogers, C. W.; Kocmond, W. C.; Pilie, R. J.

    1973-01-01

    A field investigation of the microphysical and micrometeorological features of fogs occurring near Los Angeles and Vandenberg, California was conducted. Observations of wind speed and direction, temperature, dew point, vertical wind velocity, dew deposition, drop-size distribution, liquid water content, and haze and cloud nucleus concentration were obtained. These observations were initiated in late evening prior to fog formation and continued until the time of dissipation in both advection and radiation fogs. Data were also acquired in one valley fog and several dense haze situations. The behavior of these parameters prior to and during fog are discussed in detail. A two-dimensional numerical model was developed to investigate the formation and dissipation of advection fogs under the influence of horizontal variations in surface temperature. The model predicts the evolution of potential temperature, water vapor content, and liquid water content in a vertical plane as determined by vertical turbulent transfer and horizontal advection. Results are discussed from preliminary numerical experiments on the formation of warm-air advection fog and dissipation by natural and artificial heating from the surface.

  9. Experimental investigation of barium spectra in crossed electric and magnetic fields

    Institute of Scientific and Technical Information of China (English)

    Quan Wei; Liu Hong-Ping; Shen Li; Zhan Ming-Sheng

    2007-01-01

    This paper has studied the barium spectra in external magnetic and electric fields on the recently-built system based on a super-conducting solenoid with high stability of better than 1 Gauss. Firstly, we compared the spectra in a high pure magnetic field of B = 4.00000T for different polarized laser, σ+ and σ-. We prove that after a proper shift,the σ+ and σ- spectra are completely identical. We also investigated the dependence of the spectral feature in the high magnetic field on an additionally applied crossing electric field. Along with the increase of the electric field, there is an energy shift for every spectral line. Based on a transformative Hamiltonian, we explained this energy shift well.

  10. Investigation on acoustic holography reconstruction of scattering field of target

    Institute of Scientific and Technical Information of China (English)

    BAO Xuemei; HE Zuoyong

    2000-01-01

    The BEM-based (Boundary EIement Method) scattering near field acoustic holography technique, which can be used to reconstruct the scattering sound field on the surface of a target and predict the whole scattering field from measured scattering near field, is described.First, the fundamental equations of this method and the related separation method for scattering field are brought forward. Then the problems such as the affect of different hologram to reconstructed result, the availability of singular value filter method and the applicability of separation method for scattering field are analyzed by means of numerical simulation.

  11. Field site investigation: Effect of mine seismicity on groundwater hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Ofoegbu, G.I.; Hsiung, S.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses; Philip, J. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-04-01

    The results of a field investigation on the groundwater-hydrologic effect of mining-induced earthquakes are presented in this report. The investigation was conducted at the Lucky Friday Mine, a silver-lead-zinc mine in the Coeur d`Alene Mining District of Idaho. The groundwater pressure in sections of three fracture zones beneath the water table was monitored over a 24-mo period. The fracture zones were accessed through a 360-m-long inclined borehole, drilled from the 5,700 level station of the mine. The magnitude, source location, and associated ground motions of mining-induced seismic events were also monitored during the same period, using an existing seismic instrumentation network for the mine, augmented with additional instruments installed specifically for the project by the center for Nuclear Waste Regulatory Analyses (CNWRA). More than 50 seismic events of Richter magnitude 1.0 or larger occurred during the monitoring period. Several of these events caused the groundwater pressure to increase, whereas a few caused it to decrease. Generally, the groundwater pressure increased as the magnitude of seismic event increased; for an event of a given magnitude, the groundwater pressure increased by a smaller amount as the distance of the observation point from the source of the event increased. The data was examined using regression analysis. Based on these results, it is suggested that the effect of earthquakes on groundwater flow may be better understood through mechanistic modeling. The mechanical processes and material behavior that would need to be incorporated in such a model are examined. They include a description of the effect of stress change on the permeability and water storage capacity of a fracture rock mass; transient fluid flow; and the generation and transmission of seismic waves through the rock mass.

  12. Investigating the Density of Isolated Field Elliptical Galaxies

    Science.gov (United States)

    Ulgen, E. Kaan

    2016-02-01

    In this thesis, 215.590 elliptical galaxies with M(r) ≤ -21 in the CFHTLS-W1 field which is covering 72 sq. deg on the sky are examined . Criterion given by Smith et al. (2004) has been used to determine isolated elliptical galaxies. 118 isolated elliptical galaxies have been determined in total. By using g, r and i photometric bands, the true-colour images of candidates are produced and visually inspected. In order to have a clean list of IfEs some candidates are excluded from the final sample after visual inspection. The final sample consists of 60 IfEs which corresponds to the 0.027 per cent of the whole sample. In other words, IfE density in the W1 is 0.8 IfE / sq.deg. Since the formation of the ellipticals in the isolated regions is not known clearly, it is crucial to determine IfEs and compare their photometric and morphological properties to the normal or cluster ellipticals. When the (g-i) distributions of three different elliptical galaxy class are compared, it is found that they have almost the same colours. When the redshift distributions of the galaxies are considered, it can be seen that IfEs formed later than the cluster and normal ellipticals. The average redshift of IfEs is determined as zphot=0.284, while for normal and cluster ellipticals, it is, respectively, 0.410 and 0.732. In addition, when the effective radii of the three elliptical systems are considered, it is found that the IfEs are bigger than the other two elliptical classes.

  13. Results of investigations at the Ahuachapan geothermal field, El Salvador

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, B.; Goff, F.; Van Eeckhout, E.; Hanold, B. (comps.)

    1990-04-01

    Well logging operations were performed in eight of the geothermal wells at Ahuachapan. High-temperature downhole instruments, including a temperature/rabbit, caliper, fluid velocity spinner/temperature/pressure (STP), and fluid sampler, were deployed in each well. The caliper tool was used primarily to determine if chemical deposits were present in well casings or liners and to investigate a suspected break in the casing in one well. STP logs were obtained from six of the eight wells at various flow rates ranging from 30 to 80 kg/s. A static STP log was also run with the wells shut-in to provide data to be used in the thermodynamic analysis of several production wells. The geochemical data obtained show a system configuration like that proposed by C. Laky and associates in 1989. Our data indicate recharge to the system from the volcanic highlands south of the field. Additionally, our data indicate encroachment of dilute fluids into deeper production zones because of overproduction. 17 refs., 50 figs., 10 tabs.

  14. ECOLOGICAL INVESTIGATION OF APPLICATION OF PESTICIDES IN RICE FIELDS

    Directory of Open Access Journals (Sweden)

    J. Nouri

    2000-12-01

    Full Text Available Among several pests of rice as one of the main agricultural products in Iran, rice borer, Chilo suppressalis is one of the most important pests of this crop. Use of pesticides coincided with the occurrence of this pest in the northern region of Iran in 1972. At present in order to control this pest, more than 12000 tones of pesticides granules are used annually. Ecological effects of pesticides application and the use of Trichograma sp. as a natural enemy, for assessing the impacts of pesticides in environments, especially on different living organisms on the plant, in irrigation water, and in 5 cm depth of surface soil, were investigated in two regions of Amol, named Osk. Mahalleh and Capik Field of Tashbandan. Results indicated that the two treatments were not different on croploss. One the contrary, in the pesticide treatment, there was a considerable decrease in the population of living organisms, particularly, no organism was observed in 5 cm depth of surface soil. It is recommended that in order to maintain the balance of environment, the use of chemicals for controlling rice borer must be with extreme care, only in the inevitable was with the use of principles of Integrated Pest Management.

  15. Marine ARM GPCI Investigation of Clouds (MAGIC) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Ernie R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-01

    The Marine ARM GPCI Investigation of Clouds (MAGIC) field campaign, which deployed the second ARM Mobile Facility (AMF2) aboard the Horizon Lines cargo container ship Spirit as it ran its regular route between Los Angeles, California and Honolulu, Hawaii, measured properties of clouds and precipitation, aerosols, radiation, and atmospheric, meteorological, and oceanic conditions with the goal of obtaining statistics of these properties to achieve better understanding of the transition between stratocumulus and cumulus cloud regimes that occur in that region. This Sc-Cu transition is poorly represented in models, and a major reason for this is the lack of high-quality and comprehensive data that can be used to constrain, validate, and improve model representation of the transition. MAGIC consisted of 20 round trips between Los Angeles and Honolulu, and thus over three dozen transects through the transition, totaling nearly 200 days at sea between September, 2012 and October, 2013. During this time MAGIC collected a unique and unprecedented data set, including more than 550 successful radiosonde launches. An Intensive Observational Period (IOP) occurred in July, 2013 during which more detailed measurements of the atmospheric structure were made. MAGIC was very successful in its operations and overcame numerous logistical and technological challenges, clearly demonstrating the feasibility of a marine AMF2 deployment and the ability to make accurate measurements of clouds and precipitation, aerosols, and radiation while at sea.

  16. Forsmark site investigation. Investigation of marine and lacustrine sediment in lakes. Field data 2003

    Energy Technology Data Exchange (ETDEWEB)

    Hedenstroem, Anna [SGU, Uppsala (Sweden)

    2003-04-01

    The aim of this activity is to describe the aerial and stratigraphical distribution of marine and lacustrine sediment i.e. sediment overlaying the glacial till and/or bedrock surface, in lakes in the Forsmark area. The investigation is carried out within areas where mapping of unconsolidated Quaternary deposits is presently carried out. Since small and shallow lakes cover a large part of the region, this work will give important information on the distribution and stratigraphy of sedimentary deposits not included in the regular mapping of unconsolidated Quaternary deposits within the site investigation programme. Samples were also collected for laboratory analyses of grain size distribution, mineralogical composition as well as the total content of C, N and S and calcium carbonate. The analyses will be carried out on selected samples of representative sedimentary units in order to characterise the chemical and physical properties of the unconsolidated deposits. The analytical data will be useful for the hydrogeological modelling and for models of the Quaternary evolution of the area. The mineralogical analyses of clay may provide information on the origin of the clay particles. One stratigraphic sequence from Lake Eckarfjaerden will be stored for later analyses, e.g. pollen analysis. This report includes field data from spring 2003. Together, the field data and the forthcoming results from the laboratory analyses will form the basis for construction of stratigraphical profiles to be presented in a following report in the fall 2003.

  17. MO-G-BRF-09: Investigating Magnetic Field Dose Effects in Mice: A Monte Carlo Study

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, A; Guindani, M; Followill, D; Melancon, A; Hazle, J; Court, L [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Purpose: In MRI-linac treatments, radiation dose distributions are affected by magnetic fields, especially at high-density/low-density interfaces. Radiobiological consequences of magnetic field dose effects are presently unknown; therefore, preclinical studies are needed to ensure the safe clinical use of MRI-linacs. This study investigates the optimal combination of beam energy and magnetic field strength needed for preclinical murine studies. Methods: The Monte Carlo code MCNP6 was used to simulate the effects of a magnetic field when irradiating a mouse-sized lung phantom with a 1.0cmx1.0cm photon beam. Magnetic field effects were examined using various beam energies (225kVp, 662keV[Cs-137], and 1.25MeV[Co-60]) and magnetic field strengths (0.75T, 1.5T, and 3T). The resulting dose distributions were compared to Monte Carlo results for humans with various field sizes and patient geometries using a 6MV/1.5T MRI-linac. Results: In human simulations, the addition of a 1.5T magnetic field caused an average dose increase of 49% (range:36%–60%) to lung at the soft tissue-to-lung interface and an average dose decrease of 30% (range:25%–36%) at the lung-to-soft tissue interface. In mouse simulations, the magnetic fields had no effect on the 225kVp dose distribution. The dose increases for the Cs-137 beam were 12%, 33%, and 49% for 0.75T, 1.5T, and 3.0T magnetic fields, respectively while the dose decreases were 7%, 23%, and 33%. For the Co-60 beam, the dose increases were 14%, 45%, and 41%, and the dose decreases were 18%, 35%, and 35%. Conclusion: The magnetic field dose effects observed in mouse phantoms using a Co-60 beam with 1.5T or 3T fields and a Cs-137 beam with a 3T field compare well with those seen in simulated human treatments with an MRI-linac. These irradiator/magnet combinations are suitable for preclinical studies investigating potential biological effects of delivering radiation therapy in the presence of a magnetic field. Partially funded by Elekta.

  18. Investigating DNA Migration in Pulsed Fields Using a Miniaturized Field Inversion Gel Electrophoresis System

    Science.gov (United States)

    Chen, Xiaojia; Ugaz, Victor M.

    2010-01-01

    Pulsed field gel electrophoresis (PFGE) is a well-established technique for fractionation of DNA fragments ranging from kilobases to megabases in length. But many of these separations require an undesirable combination of long experiment times (often approaching tens of hours) and application of high voltages (often approaching tens of kV). Here we present a simple miniaturized field inversion gel electrophoresis (FIGE) apparatus capable of separating DNA fragments up to 32.5 kb in length within 3 hours using a modest applied potential of 20 V. The device is small enough to be imaged under a fluorescence microscope, permitting the migrating DNA bands to be observed during the course of the separation run. We use this capability to investigate how separation performance is affected by parameters including the ratio of forward and backward voltage, pulse time, and temperature. We also characterize the dependence of DNA mobility on fragment size N, and observe a scaling in the vicinity of N−0.5 over the size range investigated. The high speed, low power consumption, and simple design of this system may help enable future studies of DNA migration in PFGE to be performed quickly and inexpensively. PMID:19053074

  19. Comparing Outcomes from Field and Classroom Based Settings for Undergraduate Geoscience Courses

    Science.gov (United States)

    Skinner, M. R.; Harris, R. A.; Flores, J.

    2011-12-01

    Field based learning can be found in nearly every course offered in Geology at Brigham Young University. For example, in our Structural Geology course field studies substitute for labs. Students collect data their own data from several different structural settings of the Wasatch Range. Our curriculum also includes a two-week, sophomore-level field course that introduces students to interpreting field relations themselves and sets the stage for much of what they learn in their upper-division courses. Our senior-level six-week field geology course includes classical field mapping with exercises in petroleum and mineral exploration, environmental geology and geological hazards. Experiments with substituting field-based general education courses for those in traditional classroom settings indicate that student cognition, course enjoyment and recruiting of majors significantly increase in a field-based course. We offer a field-based introductory geology course (Geo 102) that is taught in seven, six-hour field trips during which students travel to localities of geologic interest to investigate a variety of fundamental geological problems. We compare the outcomes of Geo 102 with a traditional classroom-based geology course (Geo 101). For the comparison both courses are taught by the same instructor, use the same text and supplementary materials and take the same exams. The results of 7 years of reporting indicate that test scores and final grades are one-half grade point higher for Geo 102 students versus those in traditional introductory courses. Student evaluations of the course are also 0.8-1.4 points higher on a scale of 1-8, and are consistently the highest in the Department and College. Other observations include increased attendance, attention and curiosity. The later two are measured by the number of students asking questions of other students as well as the instructors, and the total number of questions asked during class time in the field versus the classroom

  20. Urban and marine corrosion: Comparative behaviour between field and laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Iribarren Laco, J.I.; Liesa Mestres, F.; Bilurbina Alter, L. [Departament d' Enginyeria Quimica E.T.S.E.I.B. Universitat Politecnica de Catalunya, Barcelona (Spain); Cadena Villota, F. [Departamento de Materiales, Escuela Politecnica Nacional, Quito (Ecuador)

    2004-09-01

    A detailed study of the corrosion phenomena of carbon steel has been investigated in this work by means of the comparison of field and laboratory tests. Two areas of the metropolitan area of Barcelona (Spain) were selected to carry out the field tests, whereas two different solutions of sodium chloride and sodium hydrogen sulfite were used to simulate the field conditions by means of cyclic laboratory tests. The corrosion rate has been evaluated from the weight loss of the specimens and the morphology surface has been visualized by optical and scanning electron microscopy. Corrosion products and contaminants have been analyzed by X-ray diffraction and energy-dispersive X-ray spectroscopy, respectively. The penetration results can be adjusted to the Passano equation and the corrosivity degree can be assigned in accordance with ISO standards. A correlation between field and laboratory tests has been found, by comparing the specimens with the same degree of corrosion, showing the validity of the accelerated laboratory tests in order to simulate the field conditions. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  1. Policy forum: studying eyewitness investigations in the field.

    Science.gov (United States)

    Schacter, Daniel L; Dawes, Robyn; Jacoby, Larry L; Kahneman, Daniel; Lempert, Richard; Roediger, Henry L; Rosenthal, Robert

    2008-02-01

    This article considers methodological issues arising from recent efforts to provide field tests of eyewitness identification procedures. We focus in particular on a field study (Mecklenburg 2006) that examined the "double blind, sequential" technique, and consider the implications of an acknowledged methodological confound in the study. We explain why the confound has severe consequences for assessing the real-world implications of this study.

  2. COMPARATIVE STUDY ON MAIN SOLVENCY ASSESSMENT MODELS FOR INSURANCE FIELD

    Directory of Open Access Journals (Sweden)

    Daniela Nicoleta SAHLIAN

    2015-07-01

    Full Text Available During the recent financial crisis of insurance domain, there were imposed new aspects that have to be taken into account concerning the risks management and surveillance activity. The insurance societies could develop internal models in order to determine the minimum capital requirement imposed by the new regulations that are to be adopted on 1 January 2016. In this respect, the purpose of this research paper is to offer a real presentation and comparing with the main solvency regulation systems used worldwide, the accent being on their common characteristics and current tendencies. Thereby, we would like to offer a better understanding of the similarities and differences between the existent solvency regimes in order to develop the best regime of solvency for Romania within the Solvency II project. The study will show that there are clear differences between the existent Solvency I regime and the new approaches based on risk and will also point out the fact that even the key principles supporting the new solvency regimes are convergent, there are a lot of approaches for the application of these principles. In this context, the question we would try to find the answer is "how could the global solvency models be useful for the financial surveillance authority of Romania for the implementation of general model and for the development of internal solvency models according to the requirements of Solvency II" and "which would be the requirements for the implementation of this type of approach?". This thing makes the analysis of solvency models an interesting exercise.

  3. Comparing and Reconciling Traditional Field and Photogeologic Mapping Techniques: Lessons from the San Francisco Volcanic Field, Arizona

    Science.gov (United States)

    Skinner, J. A., Jr.; Eppler, D. B.; Bleacher, J. E.; Evans, C. A.; Feng, W.; Gruener, J.; Hurwitz, D. M.; Janoiko, B.; Whitson, P.

    2014-01-01

    Cartographic products and - specifically - geologic maps provide critical assistance for establishing physical and temporal frameworks of planetary surfaces. The technical methods that result in the creation of geologic maps vary depending on how observations are made as well as the overall intent of the final products [1-3]. These methods tend to follow a common linear work flow, including the identification and delineation of spatially and temporally discrete materials (units), the documentation of their primary (emplacement) and secondary (erosional) characteristics, analysis of the relative and absolute age relationships between these materials, and the collation of observations and interpretations into an objective map product. The "objectivity" of a map is critical cross comparison with overlapping maps and topical studies as well as its relevance to scientific posterity. However, the "accuracy" and "correctness" of a geologic map is very subject to debate. This can be evidenced by comparison of existing geologic maps at various scales, particularly those compiled through field- and remote-based mapped efforts. Our study focuses on comparing the fidelity of (1) "Apollo-style" geologic investigations, where typically non-geologist crew members follow static traverse routes established through pre-mission planning, and (2) "traditional" field-based investigations, where geologists are given free rein to observe without preplanned routes. This abstract summarizes the regional geology wherein our study was conducted, presents the geologic map created from traditional field mapping techniques, and offers basic insights into how geologic maps created from different tactics can be reconciled in support of exploratory missions. Additional abstracts [4-6] from this study discuss various exploration and science results of these efforts.

  4. Apparatus for ground water chemistry investigations in field caissons

    Energy Technology Data Exchange (ETDEWEB)

    Cokal, E.J.; Stallings, E.; Walker, R.; Nyhan, J.W.; Polzer, W.L.; Essington, E.H.

    1985-01-01

    Los Alamos is currently in its second season of ground water chemistry and hydrology experimentation in a field facility that incorporates clusters of six, 3-meter-diameter by 6-meter-deep, soil-filled caissons and required ancillaries. Initial experience gained during the 1983 field season indicated the need for further development of the technology of this type of experimentation supporting hydrologic waste management research. Uniform field application of water/matrix solutions to the caisson, matrix and tracer solution blending/storage, and devices for ground water sampling are discussed.

  5. Extending methods: using Bourdieu's field analysis to further investigate taste

    Science.gov (United States)

    Schindel Dimick, Alexandra

    2015-06-01

    In this commentary on Per Anderhag, Per-Olof Wickman and Karim Hamza's article Signs of taste for science, I consider how their study is situated within the concern for the role of science education in the social and cultural production of inequality. Their article provides a finely detailed methodology for analyzing the constitution of taste within science education classrooms. Nevertheless, because the authors' socially situated methodology draws upon Bourdieu's theories, it seems equally important to extend these methods to consider how and why students make particular distinctions within a relational context—a key aspect of Bourdieu's theory of cultural production. By situating the constitution of taste within Bourdieu's field analysis, researchers can explore the ways in which students' tastes and social positionings are established and transformed through time, space, place, and their ability to navigate the field. I describe the process of field analysis in relation to the authors' paper and suggest that combining the authors' methods with a field analysis can provide a strong methodological and analytical framework in which theory and methods combine to create a detailed understanding of students' interest in relation to their context.

  6. Improved normal tissue protection by proton and X-ray microchannels compared to homogeneous field irradiation.

    Science.gov (United States)

    Girst, S; Marx, C; Bräuer-Krisch, E; Bravin, A; Bartzsch, S; Oelfke, U; Greubel, C; Reindl, J; Siebenwirth, C; Zlobinskaya, O; Multhoff, G; Dollinger, G; Schmid, T E; Wilkens, J J

    2015-09-01

    The risk of developing normal tissue injuries often limits the radiation dose that can be applied to the tumour in radiation therapy. Microbeam Radiation Therapy (MRT), a spatially fractionated photon radiotherapy is currently tested at the European Synchrotron Radiation Facility (ESRF) to improve normal tissue protection. MRT utilizes an array of microscopically thin and nearly parallel X-ray beams that are generated by a synchrotron. At the ion microprobe SNAKE in Munich focused proton microbeams ("proton microchannels") are studied to improve normal tissue protection. Here, we comparatively investigate microbeam/microchannel irradiations with sub-millimetre X-ray versus proton beams to minimize the risk of normal tissue damage in a human skin model, in vitro. Skin tissues were irradiated with a mean dose of 2 Gy over the irradiated area either with parallel synchrotron-generated X-ray beams at the ESRF or with 20 MeV protons at SNAKE using four different irradiation modes: homogeneous field, parallel lines and microchannel applications using two different channel sizes. Normal tissue viability as determined in an MTT test was significantly higher after proton or X-ray microchannel irradiation compared to a homogeneous field irradiation. In line with these findings genetic damage, as determined by the measurement of micronuclei in keratinocytes, was significantly reduced after proton or X-ray microchannel compared to a homogeneous field irradiation. Our data show that skin irradiation using either X-ray or proton microchannels maintain a higher cell viability and DNA integrity compared to a homogeneous irradiation, and thus might improve normal tissue protection after radiation therapy.

  7. Structural investigations of Great Basin geothermal fields: Applications and implications

    Energy Technology Data Exchange (ETDEWEB)

    Faulds, James E [Nevada Bureau of Mines and Geology, Univ. of Nevada, Reno, NV (United States); Hinz, Nicholas H. [Nevada Bureau of Mines and Geology, Univ. of Nevada, Reno, NV (United States); Coolbaugh, Mark F [Great Basin Center for Geothermal Energy, Univ. of Nevada, Reno, NV (United States)

    2010-11-01

    Because fractures and faults are commonly the primary pathway for deeply circulating hydrothermal fluids, structural studies are critical to assessing geothermal systems and selecting drilling targets for geothermal wells. Important tools for structural analysis include detailed geologic mapping, kinematic analysis of faults, and estimations of stress orientations. Structural assessments are especially useful for evaluating geothermal fields in the Great Basin of the western USA, where regional extension and transtension combine with high heat flow to generate abundant geothermal activity in regions having little recent volcanic activity. The northwestern Great Basin is one of the most geothermally active areas in the USA. The prolific geothermal activity is probably due to enhanced dilation on N- to NNE-striking normal faults induced by a transfer of NW-directed dextral shear from the Walker Lane to NW-directed extension. Analysis of several geothermal fields suggests that most systems occupy discrete steps in normal fault zones or lie in belts of intersecting, overlapping, and/or terminating faults. Most fields are associated with steeply dipping faults and, in many cases, with Quaternary faults. The structural settings favoring geothermal activity are characterized by subvertical conduits of highly fractured rock along fault zones oriented approximately perpendicular to the WNW-trending least principal stress. Features indicative of these settings that may be helpful in guiding exploration for geothermal resources include major steps in normal faults, interbasinal highs, groups of relatively low discontinuous ridges, and lateral jogs or terminations of mountain ranges.

  8. GRACE gravity field modeling with an investigation on correlation between nuisance parameters and gravity field coefficients

    Science.gov (United States)

    Zhao, Qile; Guo, Jing; Hu, Zhigang; Shi, Chuang; Liu, Jingnan; Cai, Hua; Liu, Xianglin

    2011-05-01

    The GRACE (Gravity Recovery And Climate Experiment) monthly gravity models have been independently produced and published by several research institutions, such as Center for Space Research (CSR), GeoForschungsZentrum (GFZ), Jet Propulsion Laboratory (JPL), Centre National d’Etudes Spatiales (CNES) and Delft Institute of Earth Observation and Space Systems (DEOS). According to their processing standards, above institutions use the traditional variational approach except that the DEOS exploits the acceleration approach. The background force models employed are rather similar. The produced gravity field models generally agree with one another in the spatial pattern. However, there are some discrepancies in the gravity signal amplitude between solutions produced by different institutions. In particular, 10%-30% signal amplitude differences in some river basins can be observed. In this paper, we implemented a variant of the traditional variational approach and computed two sets of monthly gravity field solutions using the data from January 2005 to December 2006. The input data are K-band range-rates (KBRR) and kinematic orbits of GRACE satellites. The main difference in the production of our two types of models is how to deal with nuisance parameters. This type of parameters is necessary to absorb low-frequency errors in the data, which are mainly the aliasing and instrument errors. One way is to remove the nuisance parameters before estimating the geopotential coefficients, called NPARB approach in the paper. The other way is to estimate the nuisance parameters and geopotential coefficients simultaneously, called NPESS approach. These two types of solutions mainly differ in geopotential coefficients from degree 2 to 5. This can be explained by the fact that the nuisance parameters and the gravity field coefficients are highly correlated, particularly at low degrees. We compare these solutions with the official and published ones by means of spectral analysis. It is

  9. Rapid core field variations during the satellite era: Investigations using stochastic process based field models

    DEFF Research Database (Denmark)

    Finlay, Chris; Olsen, Nils; Gillet, Nicolas

    . We report spherical harmonic spectra, comparisons to observatory monthly means, and maps of the radial field at the core-mantle boundary, from the resulting ensemble of core field models. We find that inter-annual fluctuations in the external field (for example related to high solar-driven activity...

  10. Comparative investigation of creep behavior of ceramic fiber-reinforced alumina and silica aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoguang; Wei, Jing [School of Energy and Power Engineering, Beihang University, P.O. Box 405, Beijing 100191 (China); Shi, Duoqi, E-mail: shdq@buaa.edu.cn [School of Energy and Power Engineering, Beihang University, P.O. Box 405, Beijing 100191 (China); Sun, Yantao; Lv, Shuangqi [School of Energy and Power Engineering, Beihang University, P.O. Box 405, Beijing 100191 (China); Feng, Jian; Jiang, Yonggang [National Key Laboratory of Science and Technology on Advanced Ceramic Fibers and Composites, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-07-15

    Ambient and high temperature creep experiments at constant stresses of 0.05 MPa and 0.2 MPa were conducted on a ceramic fiber-reinforced alumina aerogel. Experimental results show that at low temperature (below 300 °C), there is no significant creep phenomenon at low stress level (0.05 MPa), but time-dependent creep deformation is found at high stress level (0.2 MPa) for the material. Scanning Electron Microscope (SEM) analysis was also conducted to understand the micro mechanism of the creep behavior. Crack initiation and propagation in matrix are the key factors that change the creep property. Comparative investigation of creep properties was also carried out between ceramic fiber-reinforced alumina and silica aerogel. Finally the application prospect of the two composites was discussed. The result shows that alumina aerogel has excellent creep resistance, thermal stability and heat insulation properties at high temperature (above 800 °C), and it has a good application prospect in high temperature insulation fields, while the ceramic fiber-reinforced silica aerogel, limited by the sintering and poor creep resistance under high temperature, is more suitable for low temperature (below 600 °C) insulation field.

  11. Investigation of nanogap localized field enhancement in gold plasmonic structures

    Science.gov (United States)

    Debu, Desalegn Tadesse; Bauman, Stephen; Saylor, Cameron; Novak, Eric; French, David; Herzog, Joseph

    2015-03-01

    Nanogaps between plasmonic structures allow confining the localized electric field with moreenhancements. Based on previously implemented two-step lithography process, we introducea nano-masking technique to fabricate nanostructrues and nanogaps for various geometrical patterns. This new method can fabricate gold nanostructures as well as nanogaps that are less than 10nm, below the limiting scale of lithography. Simulation from finite element method (FEM) shows strong gap dependence of optical properties and peak enhancement of these devices. The fabricated plasmonic nanostructure provides wide range of potential future application including highly sensitive optical antenna, surface enhanced Raman spectroscopy and biosensing.

  12. Magnetic Field Configuration at the Galactic Center Investigated by Wide Field Near-Infrared Polarimetry

    CERN Document Server

    Nishiyama, Shogo; Hatano, Hirofumi; Kanai, Saori; Kurita, Mikio; Sato, Shuji; Matsunaga, Noriyuki; Nagata, Tetsuya; Nagayama, Takahiro; Kandori, Ryo; Nakajima, Yasushi; Kusakabe, Nobuhiko; Sato, Yaeko; Hough, James H; Sugitani, Koji; Okuda, Haruyuki

    2008-01-01

    We present a polarimetric map of a 20'x20' area toward the Galactic center. The polarization of point sources has been measured in the J, H, and Ks bands using the near-infrared polarimetric camera SIRPOL on the 1.4 m telescope IRSF. One percent or better accuracy of polarization degree is achieved for sources with J<14.5, H<13.5, and Ks<12.0. Comparing the Stokes parameters between high extinction stars and relatively low extinction ones, we have obtained a polarization originating from magnetically aligned dust grains at the central region of our Galaxy of at most 1-2 kpc. The distribution of the position angles shows a peak at about 20 deg, nearly parallel to the Galactic plane, suggesting a toroidal magnetic configuration. The derived direction of the magnetic field is in good agreement with that obtained from far-infrared/submillimeter observations, which detect polarized thermal emission from dust in the molecular clouds at the Galactic center. Our results show that by subtracting foreground co...

  13. Fuzzy Scalar Field Theories: Numerical and Analytical Investigations

    CERN Document Server

    Medina, Julieta

    2006-01-01

    This thesis is devoted to the study of Quantum Field Theories (QFT) on fuzzy spaces. Fuzzy spaces are approximations to the algebra of functions of a continuous space by a finite matrix algebra. In the limit of infinitely large matrices the formulation is exact. An attractive feature of this approach is that it transparently shows how the geometrical properties of the continuous space are preserved. In the study of the non-perturbative regime of QFT, fuzzy spaces provide a possible alternative to the lattice as a regularisation method. The thesis is divided into two parts. We perform Monte Carlo simulations of a $\\lambda \\phi^4$ theory on a 3-dimensional Euclidean space. We identify the phase diagram of this model. In addition to the usual disordered and uniform ordered phases we find a third phase of non-uniform ordering. This indicates the existence of the phenomenon called UV-IR mixing in the strong coupling regime. Second we present a geometrical analysis of the scalar field theory on a 4-dimensional fuzz...

  14. Investigation of the three-dimensional flow field within a transonic fan rotor: Experiment and analysis

    Science.gov (United States)

    Pierzga, M. J.; Wood, J. R.

    1984-01-01

    An experimental investigation of the three dimensional flow field through a low aspect ratio, transonic, axial flow fan rotor has been conducted using an advanced laser anemometer (LA) system. Laser velocimeter measurements of the rotor flow field at the design operating speed and over a range of through flow conditions are compared to analytical solutions. The numerical technique used herein yields the solution to the full, three dimensional, unsteady Euler equations using an explicit time marching, finite volume approach. The numerical analysis, when coupled with a simplified boundary layer calculation, generally yields good agreement with the experimental data. The test rotor has an aspect ratio of 1.56, a design total pressure ratio of 1.629 and a tip relative Mach number of 1.38. The high spatial resolution of the LA data matrix (9 radial by 30 axial by 50 blade to blade) permits details of the transonic flow field such as shock location, turning distribution and blade loading levels to be investigated and compared to analytical results.

  15. Investigation of the three-dimensional flow field within a transonic fan rotor - Experiment and analysis

    Science.gov (United States)

    Pierzga, M. J.; Wood, J. R.

    1984-01-01

    An experimental investigation of the three-dimensional flow field through a low aspect ratio, transonic, axial flow fan rotor has been conducted, using an advanced laser anemometer (LA) system. Laser velocimeter measurements of the rotor flow field at the design operating speed and over a range of throughflow conditions are compared to analytical solutions. The numerical technique used herein yields the solution to the full, three-dimensional, unsteady Euler equations using an explicit time-marching, finite volume approach. The numerical analysis, when coupled with a simplified boundary layer calculation, generally yields good agreement with the experimental data. The test rotor has an aspect ratio of 1.56, a design total pressure ratio of 1.629 and a tip relative Mach number of 1.38. The high spatial resolution of the LA data matrix (9 radial x 30 axial x 50 blade-to-blade) permits details of the transonic flow field such as shock location, turning distribution, and blade loading levels to be investigated and compared to analytical results.

  16. Investigation of RF Emissions from Electric Field Dominated Plasmas

    Science.gov (United States)

    1989-03-31

    recently been investigated in more detail by Merlino and Cartier of Iowa, who also observed this nonlinear mode transition in a Penning discharge...Stair, acting dean of the College Samuel Mountain Hung, 9537 Gulf Partgccm and Polymer engineering; Patsy G. Ham- of Engineering; Dr. Carl W. Asp

  17. Integrating Field and Laboratory Investigations of Televised Violence and Aggression.

    Science.gov (United States)

    Eron, Leonard D.; Huesmann, L. Rowell

    Longitudinal and intervention laboratory studies were conducted to investigate the effects of viewing televised violence on the aggressive behavior of elementary school children. In the longitudinal study 505 children were studied over a 3-year period. The measures used included peer nominated aggression, aggression anxiety and popularity,…

  18. Field Investigation of Steamside Oxidation for TP347H

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Larsen, Ole Hede; Jensen, Søren Aakjær

    2004-01-01

    (machined on the inner side) to give a constant metal thickness so more precise wall thickness measurements could be undertaken. Machined and non-machined areas were investigated using light optical microscopy, and scanning electron microscopy with EDS analysis. The oxide on the fine-grained specimen...

  19. Durability of marine concrete structures - field investigations and modelling

    NARCIS (Netherlands)

    Polder, R.B.; Rooij, M.R. de

    2006-01-01

    This article presents a series of investigations on six concrete structures along the North Sea coast in The Netherlands. They had ages between 18 and 41 years and most of them were made using Blast Furnace Slag cement. Visual inspections showed corrosion damage in only one structure, related to rel

  20. Durability of marine concrete structures - field investigations and modelling

    NARCIS (Netherlands)

    Polder, R.B.; Rooij, M.R. de

    2005-01-01

    This article presents a series of investigations on six concrete structures along the North Sea coast in The Netherlands. They had ages between 18 and 41 years and most of them were made using Blast Furnace Slag cement. Visual inspections showed corrosion damage in only one structure, related to rel

  1. Experimental investigations of hard photon emission from strong crystalline fields

    Science.gov (United States)

    Medenwaldt, R.; Møller, S. P.; Jensen, B. N.; Strakhovenko, V. M.; Uggerhøj, E.; Worm, T.; Elsener, K.; Sona, P.; Connell, S. H.; Sellschop, J. P. F.; Avakian, R. O.; Avetisian, A. E.; Taroian, S. P.

    1992-05-01

    For the first time very pronounced high-energy photon peaks have been measured in the radiation emission from 70, 150 and 240 GeV electrons incident at 0.1-1.0 mrad to the axis in diamond and Si crystals. The energy of the photons in the peaks is 0.7-0.8 times the particle energy with yields of 50 times the Bethe-Heitler one (in diamond). The peaks consist of single photons and are caused by the influence of strong crystalline fields on emission of coherent bremsstrahlung, emitted when the ultrarelativistic electrons cross the rows of atoms in a crystal plane. The effect should be envisaged as a source for nearly monoenergetic photons in the multihundred GeV-region.

  2. Experimental investigations of hard photon emission from strong crystalline fields

    Energy Technology Data Exchange (ETDEWEB)

    Medenwaldt, R.; Moeller, S.P.; Jensen, B.N.; Strakhovenko, V.M.; Uggerhoej, E.; Worm, T. (ISA, Aarhus Univ. (Denmark)); Elsener, K. (CERN, Geneva (Switzerland)); Sona, P. (Dipt. di Fisica, Univ. Florence (Italy) Ist. Nazionale di Fisica Nucleare, Florence (Italy)); Connell, S.H.; Sellschop, J.P.F. (Schonland Research Centre for Nuclear Sciences, Univ. of Witwatersrand, Johannesburg (South Africa)); Avakian, R.O.; Avetisian, A.E.; Taroian, S.P. (Yerevan Physics Inst. (Armenia))

    1992-05-07

    For the first time very pronounced high-energy photon peaks have been measured in the radiation emission from 70, 150 and 240 GeV electrons incident at 0.1-1.0 mrad to the axis in diamond and Si crystals. The energy of the photons in the peaks is 0.7-0.8 times the particle energy with yields of 50 times the Bethe-Heitler one (in diamond). The peaks consist of single photons and are caused by the influence of strong crystalline fields on emission of coherent bremsstrahlung, emitted when the ultrarelativistic electrons cross the rows of atoms in a crystal plane. The effect should be envisaged as a source for nearly monoenergetic photons in the multihundred GeV-region. (orig.).

  3. First Investigation on the Radiation Field of the Spherical Hohlraum

    Science.gov (United States)

    Huo, Wen Yi; Li, Zhichao; Chen, Yao-Hua; Xie, Xuefei; Lan, Ke; Liu, Jie; Ren, Guoli; Li, Yongsheng; Liu, Yonggang; Jiang, Xiaohua; Yang, Dong; Li, Sanwei; Guo, Liang; Zhang, Huan; Hou, Lifei; Du, Huabing; Peng, Xiaoshi; Xu, Tao; Li, Chaoguang; Zhan, Xiayu; Yuan, Guanghui; Zhang, Haijun; Jiang, Baibin; Huang, Lizhen; Du, Kai; Zhao, Runchang; Li, Ping; Wang, Wei; Su, Jingqin; Ding, Yongkun; He, Xian-Tu; Zhang, Weiyan

    2016-07-01

    The first spherical hohlraum energetics experiment is accomplished on the SGIII-prototype laser facility. In the experiment, the radiation temperature is measured by using an array of flat-response x-ray detectors (FXRDs) through a laser entrance hole at four different angles. The radiation temperature and M -band fraction inside the hohlraum are determined by the shock wave technique. The experimental observations indicate that the radiation temperatures measured by the FXRDs depend on the observation angles and are related to the view field. According to the experimental results, the conversion efficiency of the vacuum spherical hohlraum is in the range from 60% to 80%. Although this conversion efficiency is less than the conversion efficiency of the near vacuum hohlraum on the National Ignition Facility, it is consistent with that of the cylindrical hohlraums used on the NOVA and the SGIII-prototype at the same energy scale.

  4. Comparing different stimulus configurations for population receptive field mapping in human fMRI

    Directory of Open Access Journals (Sweden)

    Ivan eAlvarez

    2015-02-01

    Full Text Available Population receptive field (pRF mapping is a widely used approach to measuring aggregate human visual receptive field properties by recording non-invasive signals using functional MRI. Despite growing interest, no study to date has systematically investigated the effects of different stimulus configurations on pRF estimates from human visual cortex. Here we compared the effects of three different stimulus configurations on a model-based approach to pRF estimation: size-invariant bars and eccentricity-scaled bars defined in Cartesian coordinates and traveling along the cardinal axes, and a novel simultaneous ‘wedge and ring’ stimulus defined in polar coordinates, systematically covering polar and eccentricity axes. We found that the presence or absence of eccentricity scaling had a significant effect on goodness of fit and pRF size estimates. Further, variability in pRF size estimates was directly influenced by stimulus configuration, particularly for higher visual areas including V5/MT+. Finally, we compared eccentricity estimation between phase-encoded and model-based pRF approaches. We observed a tendency for more peripheral eccentricity estimates using phase-encoded methods, independent of stimulus size. We conclude that both eccentricity scaling and polar rather than Cartesian stimulus configuration are important considerations for optimal experimental design in pRF mapping. While all stimulus configurations produce adequate estimates, simultaneous wedge and ring stimulation produced higher fit reliability, with a significant advantage in reduced acquisition time.

  5. Field Dependence/Independence Cognitive Style and Problem Posing: An Investigation with Sixth Grade Students

    Science.gov (United States)

    Nicolaou, Aristoklis Andreas; Xistouri, Xenia

    2011-01-01

    Field dependence/independence cognitive style was found to relate to general academic achievement and specific areas of mathematics; in the majority of studies, field-independent students were found to be superior to field-dependent students. The present study investigated the relationship between field dependence/independence cognitive style and…

  6. Investigating Call Drops with Field Measurements on Commercial Mobile Phones

    DEFF Research Database (Denmark)

    Messina, Alessandro; Caragea, Gabriel; Compta, Pol Torres

    2013-01-01

    can be done per day. In this paper we present a new methodology to investigate call drops by using mobile phones to do the measurements following the concept of citizen sensing. Therefore, a mobile application for Android is made that collects all necessary data and dumps the measurement results......One of the biggest problems nowadays for network operators are occurring call drops. This problem has been increasing in the last years specially since the advent of 3G. The investigation in the operator's network is very time intensive and due to the highly priced hardware only a few measurements...... in a centralized database where the measurements are evaluated and represented on Google Maps. With a post analysis of the measurements, a classification of the call drops results is made. The collected data is also used to show some statistics related to the battery level and the received signal strength between...

  7. Decreased functional diversity and biological pest control in conventional compared to organic crop fields.

    Science.gov (United States)

    Krauss, Jochen; Gallenberger, Iris; Steffan-Dewenter, Ingolf

    2011-01-01

    Organic farming is one of the most successful agri-environmental schemes, as humans benefit from high quality food, farmers from higher prices for their products and it often successfully protects biodiversity. However there is little knowledge if organic farming also increases ecosystem services like pest control. We assessed 30 triticale fields (15 organic vs. 15 conventional) and recorded vascular plants, pollinators, aphids and their predators. Further, five conventional fields which were treated with insecticides were compared with 10 non-treated conventional fields. Organic fields had five times higher plant species richness and about twenty times higher pollinator species richness compared to conventional fields. Abundance of pollinators was even more than one-hundred times higher on organic fields. In contrast, the abundance of cereal aphids was five times lower in organic fields, while predator abundances were three times higher and predator-prey ratios twenty times higher in organic fields, indicating a significantly higher potential for biological pest control in organic fields. Insecticide treatment in conventional fields had only a short-term effect on aphid densities while later in the season aphid abundances were even higher and predator abundances lower in treated compared to untreated conventional fields. Our data indicate that insecticide treatment kept aphid predators at low abundances throughout the season, thereby significantly reducing top-down control of aphid populations. Plant and pollinator species richness as well as predator abundances and predator-prey ratios were higher at field edges compared to field centres, highlighting the importance of field edges for ecosystem services. In conclusion organic farming increases biodiversity, including important functional groups like plants, pollinators and predators which enhance natural pest control. Preventative insecticide application in conventional fields has only short-term effects on aphid

  8. Metabolic Investigation in Gluconacetobacter xylinus and Its Bacterial Cellulose Production under a Direct Current Electric Field.

    Science.gov (United States)

    Liu, Miao; Zhong, Cheng; Zhang, Yu Ming; Xu, Ze Ming; Qiao, Chang Sheng; Jia, Shi Ru

    2016-01-01

    The effects of a direct current (DC) electric field on the growth and metabolism of Gluconacetobacter xylinus were investigated in static culture. When a DC electric field at 10 mA was applied using platinum electrodes to the culture broth, bacterial cellulose (BC) production was promoted in 12 h but was inhibited in the last 12 h as compared to the control (without DC electric field). At the cathode, the presence of the hydrogen generated a strong reductive environment that is beneficial to cell growth. As compared to the control, the activities of glycolysis and tricarboxylic acid cycle, as well as BC productivity were observed to be slightly higher in the first 12 h. However, due to the absence of sufficient oxygen, lactic acid was accumulated from pyruvic acid at 18 h, which was not in favor of BC production. At the anode, DC inhibited cell growth in 6 h when compared to the control. The metabolic activity in G. xylinus was inhibited through the suppression of the tricarboxylic acid cycle and glycolysis. At 18-24 h, cell density was observed to decrease, which might be due to the electrolysis of water that significantly dropped the pH of cultural broth far beyond the optimal range. Meanwhile, metabolites for self-protection were accumulated, for instance proline, glutamic acid, gluconic acid, and fatty acids. Notably, the accumulation of gluconic acid and lactic acid made it a really tough acid stress to cells at the anode and finally led to depression of cell growth.

  9. Field Investigation of Steamside Oxidation for TP347H

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Larsen, Ole Hede; Jensen, Søren Aakjær;

    2004-01-01

    was also investigated with grazing incidence X-ray diffraction. Results from coarse-grained and fine-grained specimens (machined and non-machined) show that grain size influenced oxide thickness and morphology. The oxides from non-machined specimens has an outer iron rich oxide and an inner iron chromium...... oxide. However a thinner oxide had grown on the fine-grained steel. The machining of fine-grained and coarse-grained specimens resulted in a thin chromium rich oxide layer. The presence of surface deformation of the inner metal surface was evident on the coarse-grained specimen but not on the fine...

  10. Effective field theory investigations of the XYZ puzzle

    Science.gov (United States)

    Segovia, Jorge

    2016-08-01

    Quantum Chromodynamics, the theory of strong interactions, predicts several types of bound states. Among them are conventional mesons (qq̅) and baryons (qqq), which have been the only states observed in experiments for years. However, in the last decade, many states that do not fit this picture have been observed at B-factories (BaBar, Belle and CLEO), at τ-charm facilities (CLEO-c, BESIII) and also at proton-proton colliders (CDF, D0, LHCb, ATLAS, CMS). There is growing evidence that at least some of the new charmonium- and bottomonium-like states, the so-called XYZ mesons, are new forms of matter such as quark-gluon hybrids, mesonic molecules or different arrangements of tetraquarks, pentaquarks... Effective Field Theories (EFTs) have been constructed for heavy-quark-antiquark bound states, but a general study of the XYZ mesons within the same framework has not yet been done. The scope of this conference proceedings is to discuss the possibilities we have in developing novel EFTs that, characterizing the conventional quarkonium states, facilitate also the systematic and model-independent description of the new exotic matter, in particular, the hybrid mesons.

  11. Investigations And Techniques In Nonperturbative Quantum Field Theory

    CERN Document Server

    Sprague, K B

    1999-01-01

    In Part I, the contributions of the dimension-3 fermion- antifermion and dimension-4 gluon vacuum-condensates to the electromagnetic (em) vertex of a condensing fermion are investigated. These nonperturbative contributions to the em vertex are modeled after perturbative calculations involving the exchange of a single virtual photon between incoming and outgoing fermions. Perturbative contributions to the anomalous magnetic moment of a QED fermion are calculated in terms of vertex correction structure functions evaluated at zero-momentum transfer. The QCD fermion-antifermion and gluon condensate contributions to the em vertex are found analogously using fermion, photon, and gluon propagators, thereby determining the corresponding contributions to the anomalous magnetic moment of a fermion in a vacuum that allows such condensation to occur. Such a correspondence is drawn through the adaptation of techniques used in QCD sum-rule applications. In Part II we exp...

  12. Investigation of the Stage Performance and Flow Fields in a Centrifugal Compressor with a Vaneless Diffuser

    Directory of Open Access Journals (Sweden)

    Ahti Jaatinen-Värri

    2014-01-01

    Full Text Available The effect of the width of the vaneless diffuser on the stage performance and flow fields of a centrifugal compressor is studied numerically and experimentally. The diffuser width is varied by reducing the diffuser flow area from the shroud side (i.e., pinching the diffuser. Seven different diffuser widths are studied with numerical simulation. In the modeling, the diffuser width b/b2 is varied within the range 1.00 to 0.50. The numerical results are compared with results obtained in previous studies. In addition, two of the diffusers are further investigated with experimental measurement. The main finding of the work is that the pinch reduces losses in the impeller associated with the tip-clearance flow. Furthermore, it is shown that a too large width reduction causes the flow to accelerate excessively, resulting in a highly nonuniform flow field and flow separation near the shroud.

  13. Marine ARM GPCI Investigation of Clouds Psychrometer Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, R Michael [Remote Measurements & Research Company, Seattle, WA (United States); Lewis, Ernie [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-09-01

    One of the most critical measurements in the suite of meteorological measurements used for the calculation of evaporation and latent heat flux is the relative humidity (RH). In order to achieve an overall net flux uncertainty < 10 W/m2 (Bradley and Fairall, 2006), the RH must be accurate to < 2 %RH. Anyone experienced in shipboard meteorological measurements will recognize that this is a tough specification. During the U.S. Department of Energy (DOE) Marine Atmospheric Radiation Measurement (ARM) Climate Research Facility Global Energy and Water Experiment (GEWEX) Cloud System Study (GCSS) Pacific Cross-Section Intercomparison (GPCI) Investigation of Clouds (MAGIC) experiment, the meteorological package used three different RH sensors. We found approximately 3-4 % differences between units. To arbitrate the differences and to track calibration drift over the months of exposure, we used a precision psychrometer. The Assmann Psychrometer, Model 430101 is a classic, mercury-in-glass instrument that gives a precise measure of the wet and dry bulb temperatures from which atmospheric humidity and RH are computed. On a regular basis, typically after each balloon launch, a technician took the psychrometer to an exposed location on the bridge roof. That was just below the instruments on the mast and high enough into the mixed layer that the difference is negligible.

  14. Stud arc welding in a magnetic field - Investigation of the influences on the arc motion

    Science.gov (United States)

    Hartz-Behrend, K.; Marqués, J. L.; Forster, G.; Jenicek, A.; Müller, M.; Cramer, H.; Jilg, A.; Soyer, H.; Schein, J.

    2014-11-01

    Stud arc welding is widely used in the construction industry. For welding of studs with a diameter larger than 14 mm a ceramic ferrule is usually necessary in order to protect the weld pool. Disadvantages of using such a ferrule are that more metal is molten than necessary for a high quality welded joint and that the ferrule is a consumable generally thrown away after the welding operation. Investigations show that the ferrule can be omitted when the welding is carried out in a radially symmetric magnetic field within a shielding gas atmosphere. Due to the Lorentz force the arc is laterally shifted so that a very uniform and controlled melting of the stud contact surface as well as of the work piece can be achieved. In this paper a simplified physical model is presented describing how the parameters welding current, flux density of the magnetic field, radius of the arc and mass density of the shielding gas influence the velocity of the arc motion. The resulting equation is subsequently verified by comparing it to optical measurements of the arc motion. The proposed model can be used to optimize the required field distribution for the magnetic field stud welding process.

  15. Spinal posture in different DanceSport dance styles compared with track and field athletes

    Directory of Open Access Journals (Sweden)

    Helena Kruusamäe

    2015-11-01

    Conclusions: The results of the present study suggest that smaller S-shaped vertebral curvatures of DanceSport athletes compared with track and field athletes are permanent changes rather than habitual.

  16. The SERMON project: 48 new field Blazhko stars and an investigation of modulation-period distribution

    CERN Document Server

    Skarka, Marek; Auer, Reinhold F; Prudil, Zdeněk; Juráňová, Anna; Sódor, Ádam

    2016-01-01

    We investigated 1234 fundamental mode RR Lyrae stars observed by the All Sky Automated Survey (ASAS) to identify the Blazhko (BL) effect. A sample of 1547 BL stars from the literature was collected to compare the modulation-period distribution with stars newly identified in our sample. A classical frequency spectra analysis was performed using Period04 software. Data points from each star from the ASAS database were analysed individually to avoid confusion with artificial peaks and aliases. Statistical methods were used in the investigation of the modulation-period distribution. Altogether we identified 87 BL stars (48 new detections), 7 candidate stars, and 22 stars showing long-term period variations. The distribution of modulation periods of newly identified BL stars corresponds well to the distribution of modulation periods of stars located in the Galactic field, Galactic bulge, Large Magellanic Cloud, and globular cluster M5 collected from the literature. As a very important by-product of this comparison...

  17. Analytical tools for investigating strong-field QED processes in tightly focused laser fields

    CERN Document Server

    Di Piazza, A

    2015-01-01

    The present paper is the natural continuation of the letter [Phys. Rev. Lett. \\textbf{113}, 040402 (2014)], where the electron wave functions in the presence of a background electromagnetic field of general space-time structure have been constructed analytically, assuming that the initial energy of the electron is the largest dynamical energy scale in the problem and having in mind the case of a background tightly focused laser beam. Here, we determine the scalar and the spinor propagators under the same approximations, which are useful tools for calculating, e.g., total probabilities of processes occurring in such complex electromagnetic fields. In addition, we also present a simpler and more general expression of the electron wave functions found in [Phys. Rev. Lett. \\textbf{113}, 040402 (2014)] and we indicate a substitution rule to obtain them starting from the well-known Volkov wave functions in a plane-wave field.

  18. A Web-Based Comparative Genomics Tutorial for Investigating Microbial Genomes

    Directory of Open Access Journals (Sweden)

    Michael Strong

    2009-12-01

    Full Text Available As the number of completely sequenced microbial genomes continues to rise at an impressive rate, it is important to prepare students with the skills necessary to investigate microorganisms at the genomic level. As a part of the core curriculum for first-year graduate students in the biological sciences, we have implemented a web-based tutorial to introduce students to the fields of comparative and functional genomics. The tutorial focuses on recent computational methods for identifying functionally linked genes and proteins on a genome-wide scale and was used to introduce students to the Rosetta Stone, Phylogenetic Profile, conserved Gene Neighbor, and Operon computational methods. Students learned to use a number of publicly available web servers and databases to identify functionally linked genes in the Escherichia coli genome, with emphasis on genome organization and operon structure. The overall effectiveness of the tutorial was assessed based on student evaluations and homework assignments. The tutorial is available to other educators at http://www.doe-mbi.ucla.edu/~strong/m253.php.

  19. Comparative Investigation of Mechanical–Physical Characteristics of Biodegradable and Non-Degradable Yarns

    Directory of Open Access Journals (Sweden)

    Krikštanavičienė Kira

    2014-06-01

    Full Text Available This article presents the results from investigations of tensile tests, absorbency test and degradation test of biodegradable and non- or partly biodegradable yarns produced from pure poly hydroxybutyrate-co-valerate (PHBV, poly (lactide acid (PLA, isotactic polypropylene (iPP polymers and their blends. The results indicate that mechanical-physical properties of PHBV are improved by adding PLA and iPP to PHBV. The main results indicate that the PHBV/PLA and PHBV/iPP (70/30 blends had better mechanical properties than pure PHBV, as well as improved immiscibility and the same or lower degradation in sodium chloride solution, respectively. The PHBV/PLA and PHBV/iPP blends showed a tendency for lower crystallinity and stiffness of the yarns, rendering them less stiff and fragile. The absorption tests showed that absorption dynamic process depends on the structure and raw materials of the yarns. The disinfectant in all samples is absorbed faster than blood. Research results showed that pure PHBV yarns have good hydrophobic properties, compared with pure PLA and iPP yarns. The use of additional PLA and iPP polymers changed the wetting behaviour of yarns. Absorption time of blended yarns in disinfectant liquid decreases and absorption time in the case of blood significantly increases in comparison with PLA and iPP yarns and decreases compared with PHBV yarns. The degradation tests (within 90 days in a solution of sodium chloride showed that pure PHBV and PHBV/PLA blends degraded at different rates but with the loss of the same weight, while pure PHBV and PHBV/iPP blends degraded at the same rate, but PHBV/iPP blends had worse destruction results. Such improvements are expected to be important for the practical application of PHBV in some fields

  20. Visual field examination method using virtual reality glasses compared with the Humphrey perimeter.

    Science.gov (United States)

    Tsapakis, Stylianos; Papaconstantinou, Dimitrios; Diagourtas, Andreas; Droutsas, Konstantinos; Andreanos, Konstantinos; Moschos, Marilita M; Brouzas, Dimitrios

    2017-01-01

    To present a visual field examination method using virtual reality glasses and evaluate the reliability of the method by comparing the results with those of the Humphrey perimeter. Virtual reality glasses, a smartphone with a 6 inch display, and software that implements a fast-threshold 3 dB step staircase algorithm for the central 24° of visual field (52 points) were used to test 20 eyes of 10 patients, who were tested in a random and consecutive order as they appeared in our glaucoma department. The results were compared with those obtained from the same patients using the Humphrey perimeter. High correlation coefficient (r=0.808, Pvirtual reality visual field test and the Humphrey perimeter visual field. Visual field examination results using virtual reality glasses have a high correlation with the Humphrey perimeter allowing the method to be suitable for probable clinical use.

  1. Investigation of Interaction between Deferoxamine and Low Frequency Electromagnetic Field on Angiogenesis in Chick Embryo

    Directory of Open Access Journals (Sweden)

    Atena Dashtizadeh

    2015-02-01

    Full Text Available Background: Deferoxamine (DFO is an iron chelator. In the present research, the synergic effects of deferoxamine and electromagnetic field (with 50 H frequency and 100 Gauss intensity on angiogenesis of chick chorioallantoic membrane were investigated. Materials and Methods: In this experimental study 80 fertilized egg used and randomly divided 8 group: control group, laboratory control groups of 1 and 2, experimental group 1 (treatment with electromagnetic field, 2 and 3 (treatment with deferoxamine 10, 100 µmol, respectively, 4 and 5 (treatment both deferoxamine 10 and 100 µmol respectively and electromagnetic field. On 8th day of incubation, 2 and 4 groups were incubated with 10 µL deferoxamine and for 3 and 5 groups were incubated with 10 µL deferoxamine 100 µmol. On 10th day, 1, 4 and 5 groups were put in electromagnetic field. On 12th day, the number and length of vessels in all samples was measured by Image J software. Data were analyzed by SPSS-19, ANOVA and t-test. Results: The mean number and length of vessels in the control and experimental cases did not show any significant differences. Comparison between mean number of vessels in the control and group 2, 3, 4, 5 showed a significant decrease (p<0.05 and groups 2 and 4 was showed a significant decrease in the mean length of vessels compared with the controls (p<0.05. Conclusion: Using deferoxamine with low frequency electromagnetic field (50 Hz and 100 G cause inhibition of angiogenesis in chick embryo chorioallantoic membrane.

  2. The energy budget of stellar magnetic fields: comparing non-potential simulations and observations

    CERN Document Server

    Lehmann, L T; Vidotto, A A; Mackay, D H; See, V; Donati, J -F; Folsom, C P; Jeffers, S V; Marsden, S C; Morin, J; Petit, P

    2016-01-01

    The magnetic geometry of the surface magnetic fields of more than 55 cool stars have now been mapped using spectropolarimetry. In order to better understand these observations, we compare the magnetic field topology at different surface scale sizes of observed and simulated cool stars. For ease of comparison between the high-resolution non-potential magnetofrictional simulations and the relatively low-resolution observations, we filter out the small-scale field in the simulations using a spherical harmonics decomposition. We show that the large-scale field topologies of the solar-based simulations produce values of poloidal/toroidal fields and fractions of energy in axisymmetric modes that are similar to the observations. These global non-potential evolution model simulations capture key magnetic features of the observed solar-like stars through the processes of surface flux transport and magnetic flux emergence. They do not, however, reproduce the magnetic field of M-dwarfs or stars with dominantly toroidal ...

  3. Fifty Years of "Comparative Education Review" Bibliographies: Reflections on the Field

    Science.gov (United States)

    Raby, Rosalind Latiner

    2007-01-01

    For the past three years, the "Comparative Education Review" ("CER") has published annual bibliographic essays reflecting the changes in the field over the previous year. This year, to mark the 50th anniversary of the Comparative and International Education Society (CIES), the author analyzed "CER" bibliographies since 1959, in addition to…

  4. Metabolic investigation in Gluconacetobacter xylinus and its bacterial cellulose production under a direct current electric field

    Directory of Open Access Journals (Sweden)

    Miao eLiu

    2016-03-01

    Full Text Available The effects of a direct current (DC electric field on the growth and metabolism of Gluconacetobacter xylinus were investigated in static culture. When a DC electric field at 10 mA was applied using platinum electrodes to the culture broth, bacterial cellulose (BC production was promoted in 12 hours (h but was inhibited in the last 12 h as compared to the control (without DC electric field. At the cathode, the presence of the hydrogen generated a strong reductive environment that is beneficial to cell growth. As compared to the control, the activities of glycolysis and tricarboxylic acid cycle, as well as BC productivity were observed to be slightly higher in the first 12 h. However, due to the absence of sufficient oxygen, lactic acid was accumulated from pyruvic acid at 18 h, which was not in favor of BC production. At the anode, DC inhibited cell growth in 6 h when compared to the control. The metabolic activity in G. xylinus was inhibited through the suppression of the tricarboxylic acid cycle and glycolysis. At 18-24 h, cell density was observed to decrease, which might be due to the electrolysis of water that significantly dropped the pH of cultural broth far beyond the optimal range. Meanwhile, metabolites for self-protection were accumulated, for instance proline, glutamic acid, gluconic acid and fatty acids. Notably, the accumulation of gluconic acid and lactic acid made it a really tough acid stress to cells at the anode and finally led to depression of cell growth.

  5. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

  6. Field Investigation of an Air-Source Cold Climate Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

    2017-01-01

    In the U.S., there are approximately 2.6 million dwellings that use electricity for heating in cold and very cold regions with an annual energy consumption of 0.16 quads (0.17 EJ). A high performance cold climate heat pump (CCHP) would result in significant savings over current technologies (greater than 60% compared to electric resistance heating). We developed an air-source cold climate heat pump, which uses tandem compressors, with a single compressor rated for the building design cooling load, and running two compressors to provide, at -13 F (-25 C), 75% of rated heating capacity. The tandem compressors were optimized for heating operation and are able to tolerate discharge temperatures up to 280 F (138 C). A field investigation was conducted in the winter of 2015, in an occupied home in Ohio, USA. During the heating season, the seasonal COP was measured at 3.16, and the heat pump was able to operate down to -13 F (-25 C) and eliminate resistance heat use. The heat pump maintained an acceptable comfort level throughout the heating season. In comparison to a previous single-speed heat pump in the home, the CCHP demonstrated more than 40% energy savings in the peak heating load month. This paper illustrates the measured field performance, including compressor run time, frost/defrosting operations, distributions of building heating load and capacity delivery, comfort level, field measured COPs, etc.

  7. Investigation of the behavior of protection elements against field radiated line coupled UWB-pulses

    Directory of Open Access Journals (Sweden)

    R. Krzikalla

    2006-01-01

    Full Text Available To protect electronic systems against electromagnetic interferences in general nonlinear protection circuits are used. These protection circuits are optimized mostly against special transient interferences such as lightning electromagnetic pulses (LEMP or electromagnetic pulses caused by nuclear explosions (NEMP. Previous investigations have shown that these protection elements could be undermined by so-called ultra wideband (UWB pulses. Thereby a direct charge of the UWB-pulse to the elements has been assumed. This assumption was a worst case approximation because in practice UWB-pulses only get into systems by coupling effects. In this investigation the behavior of typical nonlinear protection elements has been tested with field radiated line coupled UWB-pulses. For that line coupled UWB-pulses have been defined depending on the coupling behavior of typical electronic systems and a possibility of generation of this kind of pulses is presented. After it typical nonlinear protection elements such as spark gaps, varistors and protection diodes have been tested with the previously defined test pulses. Finally the measured behavior of the elements has been compared with the behavior by direct charged UWB-pulses and the protection effect of the elements against field radiated line coupled UWB-pulses is re-evaluated.

  8. An investigation of the statistical power of neutrality tests based on comparative and population genetic data

    DEFF Research Database (Denmark)

    Zhai, Weiwei; Nielsen, Rasmus; Slatkin, Montgomery

    2009-01-01

    In this report, we investigate the statistical power of several tests of selective neutrality based on patterns of genetic diversity within and between species. The goal is to compare tests based solely on population genetic data with tests using comparative data or a combination of comparative...... selection. The Hudson-Kreitman-Aguadé test is the most powerful test for detecting positive selection among the population genetic tests investigated, whereas McDonald-Kreitman test typically has more power to detect negative selection. We discuss our findings in the light of the discordant results obtained...

  9. Free radical scavenging activity and comparative metabolic profiling of in vitro cultured and field grown Withania somnifera roots.

    Directory of Open Access Journals (Sweden)

    Kalaiselvi Senthil

    Full Text Available Free radical scavenging activity (FRSA, total phenolic content (TPC, and total flavonoid content (TFC of in vitro cultured and field grown Withania somnifera (Ashwagandha roots were investigated. Withanolides analysis and comprehensive metabolic profiling between 100% methanol extracts of in vitro and field grown root tissues was performed using high performance thin layer chromatography (HPTLC and gas chromatography-mass spectrometry (GC-MS, respectively. Significantly higher levels of FRSA, TPC, and TFC were observed in in-vitro cultured roots compared with field grown samples. In addition, 30 day-cultured in vitro root samples (1 MIR exhibited a significantly higher FRSA (IC50 81.01 μg/mL, TPC (118.91 mg GAE/g, and TFC (32.68 mg CE/g compared with those in 45 day-cultured samples (1.5 MIR. Total of 29 metabolites were identified in in vitro cultured and field grown roots by GC-MS analysis. The metabolites included alcohols, organic acids, purine, pyrimidine, sugars, and putrescine. Vanillic acid was only observed in the in vitro cultured root samples, and higher level of the vanillic acid was observed in 1 MIR when compared to 1.5 MIR. Therefore, it is suggested that 1 MIR might serve as an alternative to field grown roots for the development of medicinal and functional food products.

  10. Free radical scavenging activity and comparative metabolic profiling of in vitro cultured and field grown Withania somnifera roots.

    Science.gov (United States)

    Senthil, Kalaiselvi; Thirugnanasambantham, Pankajavalli; Oh, Taek Joo; Kim, So Hyun; Choi, Hyung Kyoon

    2015-01-01

    Free radical scavenging activity (FRSA), total phenolic content (TPC), and total flavonoid content (TFC) of in vitro cultured and field grown Withania somnifera (Ashwagandha) roots were investigated. Withanolides analysis and comprehensive metabolic profiling between 100% methanol extracts of in vitro and field grown root tissues was performed using high performance thin layer chromatography (HPTLC) and gas chromatography-mass spectrometry (GC-MS), respectively. Significantly higher levels of FRSA, TPC, and TFC were observed in in-vitro cultured roots compared with field grown samples. In addition, 30 day-cultured in vitro root samples (1 MIR) exhibited a significantly higher FRSA (IC50 81.01 μg/mL), TPC (118.91 mg GAE/g), and TFC (32.68 mg CE/g) compared with those in 45 day-cultured samples (1.5 MIR). Total of 29 metabolites were identified in in vitro cultured and field grown roots by GC-MS analysis. The metabolites included alcohols, organic acids, purine, pyrimidine, sugars, and putrescine. Vanillic acid was only observed in the in vitro cultured root samples, and higher level of the vanillic acid was observed in 1 MIR when compared to 1.5 MIR. Therefore, it is suggested that 1 MIR might serve as an alternative to field grown roots for the development of medicinal and functional food products.

  11. Numerical Investigation of Viscous Flow Velocity Field around a Marine Cavitating Propeller

    Directory of Open Access Journals (Sweden)

    Zhifeng Zhu

    2014-11-01

    Full Text Available Velocity field around a ship cavitating propeller is investigated based on the viscous multiphase flow theory. Using a hybrid grid, the unsteady Navier-stokes (N-S and the bubble dynamics equations are solved in this paper to predict the velocity in a propeller wake and the vapor volume fraction on the back side of propeller blade for a uniform inflow. Compared with experimental results, the numerical predictions of cavitation and axial velocity coincide with the measured data. The evolution of tip vortex is shown, and the interaction between the tip vortex of the current blade and the wake of the next one occurs in the far propeller wake. The frequency of velocity signals changes from shaft rate to blade rate. The phenomena reflect the instability of propeller wake.

  12. Comparative High Field Magneto-transport Of Rare Earth Oxypnictides With Maximum Transition Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Balakirev, Fedor F [Los Alamos National Laboratory; Migliori, A [MPA-NHMFL; Riggs, S [NHMFL-FSU; Hunte, F [NHMFL-FSU; Gurevich, A [NHMFL-FSU; Larbalestier, D [NHMFL-FSU; Boebinger, G [NHMFL-FSU; Jaroszynski, J [NHMFL-FSU; Ren, Z [CHINA; Lu, W [CHINA; Yang, J [CHINA; Shen, X [CHINA; Dong, X [CHINA; Zhao, Z [CHINA; Jin, R [ORNL; Sefat, A [ORNL; Mcguire, M [ORNL; Sales, B [ORNL; Christen, D [ORNL; Mandrus, D [ORNL

    2008-01-01

    We compare magnetotransport of the three iron-arsenide-based compounds ReFeAsO (Re=La, Sm, Nd) in very high DC and pulsed magnetic fields up to 45 and 54 T, respectively. Each sample studied exhibits a superconducting transition temperature near the maximum reported to date for that particular compound. While high magnetic fields do not suppress the superconducting state appreciably, the resistivity, Hall coefficient, and critical magnetic fields, taken together, suggest that the phenomenology and superconducting parameters of the oxypnictide superconductors bridges the gap between MgB{sub 2} and YBCO.

  13. Laboratory and Field Investigations of Dynamic Effects in Soil Water Retention Curve

    Science.gov (United States)

    Chiu, Yung-Chia; Tseng, Yen-Huiang; Ye, Jiun-Yan

    2015-04-01

    The unsaturated soil is a multi-phase system and the embedded physical mechanisms and chemical reactions are very complicated. The characteristics of groundwater flow and mechanisms of mass transport are still ambiguous so far. In order to fully understand the flow and transport in the unsaturated zone, the soil water retention curve plays an important role in description of water flow. However, the measurements and calculations of soil water retention curve are usually obtained under the static condition or steady state (equilibrium), in which the dynamic effects (non-equilibrium) are not considered, and the obtained relationship between capillary pressure and saturation is skeptical. Therefore, the sandbox experiments and field tests will be conducted to discuss the dynamic effects in the soil water retention curve and hysteresis effect in this study. In the laboratory, the relations between capillary pressure, saturation, the rate of change of water content, and dynamic constant are evaluated through different setting of boundary conditions and different sizes of particles. In the field, the tests are conducted to describe the soil water retention curve through the rain simulator and artificial evaporation. Besides, the dynamic dewpoint potentiameter is used to analyze the hysteresis effect of soil samples, and its results are compared with the results obtained from sandbox and field experiments. Finally, through a series of experiments, the relationship between capillary pressure and saturation under the dynamic effects is established, and the associated theories and mechanisms are discussed. The works developed in this study can provide as reference tools for the hydrogeological investigation and contaminated site remediation in the future. Keywords: capillary pressure, saturation, soil water retention curve, hysteresis, sandbox experiment, field test

  14. Investigation on the Field Performance of Four Weeding Methods for Peanut

    Directory of Open Access Journals (Sweden)

    S Firouzi

    2011-09-01

    Full Text Available In this research, field performance of four weeding methods for peanut crop was investigated in Kiashahr located at Guilan province. The weeding methods were included weeding by two types of motorized weeders (power tiller operated cultivator and power tiller operated rotovator at three forward speeds of 1.0, 1.5 and 2.0 km/h, weeding by hand-driven wheeled cultivator and hand weeding by trench hoe. A randomized complete block design with three replications was used for the experiment. Weeding index, crop yield, field capacity, energy consumption and the economical index of benefit-cost ratio were measured and determined. Results showed that the highest weeding efficiencies of 98.61 and 97.37% were obtained in hand weeding for the first and second weeding stages, respectively. In all the mechanical treatments, the weeding efficiency of the second stage was greater than that of the first stage. The highest value of field capacity in the first stage (0.1263 km/h and second stage (0.1287 ha/h was recorded for power tiller operated rotovator at travel speed of 2.0 km/h. with amount of field efficiency was achieved in weeding with tiller rotovator at forward speed of 2 km/h (0.1263 and 0.1287 ha/h for first and second stages of weeding operation respectively. Among the methods, the lowest value of energy consumption with the average of 307.8 Mj/ha was registered for hand-driven wheeled cultivator. Results also indicated that power tiller operated rotovator at forward speed of 1.0 km/h had the highest benefit-cost ratio of 2.06 compared to other treatments. Thus, weeding by power tiller operated rotovator at forward speed of 1.0 km/h is advisable for peanut cultivation in the region.

  15. A comparative study of energy minimization methods for Markov random fields with smoothness-based priors.

    Science.gov (United States)

    Szeliski, Richard; Zabih, Ramin; Scharstein, Daniel; Veksler, Olga; Kolmogorov, Vladimir; Agarwala, Aseem; Tappen, Marshall; Rother, Carsten

    2008-06-01

    Among the most exciting advances in early vision has been the development of efficient energy minimization algorithms for pixel-labeling tasks such as depth or texture computation. It has been known for decades that such problems can be elegantly expressed as Markov random fields, yet the resulting energy minimization problems have been widely viewed as intractable. Recently, algorithms such as graph cuts and loopy belief propagation (LBP) have proven to be very powerful: for example, such methods form the basis for almost all the top-performing stereo methods. However, the tradeoffs among different energy minimization algorithms are still not well understood. In this paper we describe a set of energy minimization benchmarks and use them to compare the solution quality and running time of several common energy minimization algorithms. We investigate three promising recent methods graph cuts, LBP, and tree-reweighted message passing in addition to the well-known older iterated conditional modes (ICM) algorithm. Our benchmark problems are drawn from published energy functions used for stereo, image stitching, interactive segmentation, and denoising. We also provide a general-purpose software interface that allows vision researchers to easily switch between optimization methods. Benchmarks, code, images, and results are available at http://vision.middlebury.edu/MRF/.

  16. Investigation of fault structures from microseismicity in the Wairakei geothermal field, New Zealand

    Science.gov (United States)

    Kim, Jongchan; Boese, Carolin; Andrews, Jennifer; Sepulveda, Favian; Archer, Rosalind; Malin, Peter

    2014-05-01

    The Wairakei geothermal field is located in the centre of a NNE-trending rifting arc, called the Taupo Volcanic Zone (TVZ), New Zealand. In 1958, commercial production of electricity started at the Wairakei field, which currently holds the largest installed capacity of the TVZ (~375 MWe). For some operational reasons, large scale infield re-injection started in the mid 1990's (Otupu area; east of Wairakei) and further extended to the south (Karapiti area) in August 2011. Small scale re-injection trials have been also being conducted since 2012 (West of Wairakei). In total, 13 borehole seismometers have been installed in the Wairakei geothermal field since 2009 to support reservoir management and drilling strategies, and observe the reservoir response to production and injection. The range of installation depths is 65 m to 1,200 m. About 97% of the 7049 events recorded have magnitude ≤2, in the so-called micro-earthquake range, and locate above 6 km depth. The micro-seismicity distribution tends to be diffuse. Although some correlation with geological units and faults can be made, identification of distinct fractures is challenging. In this study, we investigate active fault structures from micro-seismic events occurring in the geothermal field between March 2009 and June 2013 using focal mechanism, clustering and double-difference relocation methods. We firstly calculate double-couple focal mechanism solutions from the micro-seismic data set using HASH. To reduce uncertainty of focal mechanism parameters, P-wave first motion polarities from 12 GeoNet stations installed in the vicinity of the Wairakei were combined with those of 13 Wairakei stations within the field. In total, 21 focal mechanisms with more than eight P-wave polarities have been computed. Most focal mechanisms are consistent in showing a NNE-trending nodal plane, and have normal or strike-slip mechanisms, coinciding well with the overall extensional tectonic regime and mapped active faults in the

  17. Comparison of field-scale herbicide runoff and volatilization losses: an eight-year field investigation.

    Science.gov (United States)

    Gish, Timothy J; Prueger, John H; Daughtry, Craig S T; Kustas, William P; McKee, Lynn G; Russ, Andrew L; Hatfield, Jerry L

    2011-01-01

    An 8-yr study was conducted to better understand factors influencing year-to-year variability in field-scale herbicide volatilization and surface runoff losses. The 21-ha research site is located at the USDA-ARS Beltsville Agricultural Research Center in Beltsville, MD. Site location, herbicide formulations, and agricultural management practices remained unchanged throughout the duration of the study. Metolachlor [2-chloro--(2-ethyl-6-methylphenyl)--(2-methoxy-1-methylethyl) acetamide] and atrazine [6-chloro--ethyl--(1-methylethyl)-1,3,5-triazine-2,4-diamine] were coapplied as a surface broadcast spray. Herbicide runoff was monitored from a month before application through harvest. A flux gradient technique was used to compute volatilization fluxes for the first 5 d after application using herbicide concentration profiles and turbulent fluxes of heat and water vapor as determined from eddy covariance measurements. Results demonstrated that volatilization losses for these two herbicides were significantly greater than runoff losses ( < 0.007), even though both have relatively low vapor pressures. The largest annual runoff loss for metolachlor never exceeded 2.5%, whereas atrazine runoff never exceeded 3% of that applied. On the other hand, herbicide cumulative volatilization losses after 5 d ranged from about 5 to 63% of that applied for metolachlor and about 2 to 12% of that applied for atrazine. Additionally, daytime herbicide volatilization losses were significantly greater than nighttime vapor losses ( < 0.05). This research confirmed that vapor losses for some commonly used herbicides frequently exceeds runoff losses and herbicide vapor losses on the same site and with the same management practices can vary significantly year to year depending on local environmental conditions.

  18. Far Field Extrapolation from Near Field Interactions and Shielding Influence Investigations Based on a FE-PEEC Coupling Method

    Directory of Open Access Journals (Sweden)

    Gérard Meunier

    2013-03-01

    Full Text Available Regarding standards, it is well established that common mode currents are the main source of far field emitted by variable frequency drive (VFD-cable-motor associations. These currents are generated by the combination of floating potentials with stray capacitances between these floating potential tracks and the mechanical parts connected to the earth (the heatsink or cables are usual examples. Nowadays, due to frequency and power increases, the systematic compliance to EMC (ElectroMagnetic Compatibility becomes increasingly difficult and costly for industrials. As a consequence, there is a well-identified need to investigate practical and low cost solutions to reduce the radiated fields of VFD-cable-motor associations. A well-adapted solution is the shielding of wound components well known as the major source of near magnetic field. However, this solution is not convenient, it is expensive and may not be efficient regarding far field reduction. Optimizing the components placement could be a better and cheaper solution. As a consequence, dedicated tools have to be developed to efficiently investigate not easy comprehendible phenomena and finally to control EMC disturbances using component placement, layout geometry, shielding design if needed. However, none of the modeling methods usually used in industry complies with large frequency range and far field models including magnetic materials, multilayer PCBs, and shielding. The contribution of this paper is to show that alternatives regarding modeling solutions exist and can be used to get in-deep analysis of such complex structures. It is shown in this paper that near field investigations can give information on far field behavior. It is illustrated by an investigation of near field interactions and shielding influence using a FE-PEEC hybrid method. The test case combining a common mode filter with the floating potentials tracks of an inverter is based on an industrial and commercialized VFD. The

  19. Investigation on stresses of superconductors under pulsed magnetic fields based on multiphysics model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaobin, E-mail: yangxb@lzu.edu.cn; Li, Xiuhong; He, Yafeng; Wang, Xiaojun; Xu, Bo

    2017-04-15

    Highlights: • The differential equation including temperature and magnetic field was derived for a long cylindrical superconductor. • Thermal stress and electromagnetic stress were studied at the same time under pulse field magnetizing. • The distributions of the magnetic field, the temperature and stresses are studied and compared for two pulse fields of the different duration. • The Role thermal stress and electromagnetic stress play in the process of pulse field magnetizing is discussed. - Abstract: A multiphysics model for the numerical computation of stresses, trapped field and temperature distribution of a infinite long superconducting cylinder is proposed, based on which the stresses, including the thermal stresses and mechanical stresses due to Lorentz force, and trapped fields in the superconductor subjected to pulsed magnetic fields are analyzed. By comparing the results under pulsed magnetic fields with different pulse durations, it is found that the both the mechanical stress due to the electromagnetic force and the thermal stress due to temperature gradient contribute to the total stress level in the superconductor. For pulsed magnetic field with short durations, the thermal stress is the dominant contribution to the total stress, because the heat generated by AC-loss builds up significant temperature gradient in such short durations. However, for a pulsed field with a long duration the gradient of temperature and flux, as well as the maximal tensile stress, are much smaller. And the results of this paper is meaningful for the design and manufacture of superconducting permanent magnets.

  20. Fluorescence amplified fragment length polymorphism compared to pulsed field gel electrophoresis for Listeria monocytogenes subtyping

    Directory of Open Access Journals (Sweden)

    Roussel Sophie

    2013-01-01

    Full Text Available Abstract Background Listeriosis is a severe infection which mainly affects pregnant women, neonates and immuno-compromised adults. ANSES’s Laboratory for Food safety has been the European Union Reference Laboratory (EURL for L. monocytogenes in the food chain since 2006. Pulsed Field Gel Electrophoresis (PFGE is routinely used in the EURL for the surveillance of L. monocytogenes isolated from foods, animals and the environment. One of the main EURL activities is to evaluate alternative molecular subtyping methods to PFGE, and integrate their use within the National Reference Laboratories (NRL network. Since 2008, the United Kingdom (UK-NRL for L. monocytogenes at the Health Protection Agency (HPA, London, has used fluorescent Amplified Fragment Length Polymorphism (fAFLP for the routine surveillance of L. monocytogenes isolated from human clinical cases, food and food processing environments in the UK. This study compares fAFLP with PFGE for subtyping L. monocytogenes. Results A panel of 109 L. monocytogenes isolates from either human cases of listeriosis, foods, food processing environments and animals were used for the comparative evaluation. Among these, 2 strains were tested from duplicate culture by both methods. The panel also included field isolates, isolates associated with outbreaks or sporadic cases and reference strains. The two strains tested in duplicate displayed the same fAFLP and PFGE types. Strains known to be epidemiologically associated with one another were found to have unique PFGE and fAFLP types. FAFLP and PFGE divided the strains into 76 and 82 distinct profiles, or types, respectively. The discriminatory index calculated was 0.993 and 0.996 for fAFLP and PFGE, respectively. Conclusions The discriminatory ability of fAFLP was similar to that of PFGE for the subtyping of L. monocytogenes isolates. As a less labour intensive technique fAFLP may be a better method to use than PFGE in investigating outbreaks of human

  1. Numerical Simulation and Experimental Investigation of 3-D Separated Flow Field around a Blunt Body

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    @@Motivated by re-designing a fuselage in engineering application, the numerical and experimental investigation of the separated flow field around a special blunt body is described in this thesis. The aerodynamic response of the blunt body is successively studied. The thesis consists of four parts: the numerical simulation of the flow field around a two-dimensional blunt body; the numerical simulation of the flow field around a three-dimensional blunt body; the flow

  2. Zero-field birefringence of biocompatible magnetic fluids: A concentration dependence investigation

    Energy Technology Data Exchange (ETDEWEB)

    Eloi, Marcos T.A. [Universidade de Brasilia, Instituto de Fisica, Nucleo de Fisica Aplicada, 70919-970, Brasilia - DF (Brazil); Azevedo, Ricardo B. [Departamento de Genetica e Morfologia, Universidade de Brasilia, Instituto de Ciencias Biologicas, 70910-900, Brasilia - DF (Brazil); Lima, Emilia C.D. [Universidade Federal de Goias, Instituto de Quimica, 74001-970, Goiania - GO (Brazil); Pimenta, Angela C.M. [Universidade Federal de Goias, Instituto de Quimica, 74001-970, Goiania - GO (Brazil); Morais, Paulo C. [Universidade de Brasilia, Instituto de Fisica, Nucleo de Fisica Aplicada, 70919-970, Brasilia - DF (Brazil)]. E-mail: pcmor@unb.br

    2005-05-15

    Zero-field birefringence was used to investigate maghemite-based biocompatible magnetic fluids surface-coated with citrate. The model used to analyze the birefringence signal considers the dipolar magnetic interaction among dimers and the onset of a nematic phase near the sample holder surface. The data show that zero-field birefringence grows with sample dilution.

  3. Investigation of Field-Collected Data Using Diffuse and Specular, Forward and Reverse Radiative Transfer Models

    Science.gov (United States)

    2015-03-26

    protection in the United States. AFIT-ENP-MS-15-M-100 INVESTIGATION OF FIELD-COLLECTED DATA USING DIFFUSE AND SPECULAR , FORWARD AND REVERSE...RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENP-MS-15-M-100 INVESTIGATION OF FIELD-COLLECTED DATA USING DIFFUSE AND SPECULAR , FORWARD AND REVERSE... specular and diffuse properties of a set of eight materials on diffuse-only and diffuse- specular radiative transfer models in the wavelength range of

  4. Investigation of acoustic field near to elastic thin plate using integral method

    Directory of Open Access Journals (Sweden)

    В.І. Токарев

    2004-01-01

    Full Text Available  Investigation of acoustic field near to elastic thin plate using  integral method The influence of boundary conditions on sound wave propagation, radiation and transmission through thin elastic plate is investigated. Necessary for that numerical model was found using the Helmholtz equation and equation of oscilated plate by means of integral formulation of the solution for acoustic fields near to elastic thin plate and for bending waves of small amplitudes.

  5. Investigation of co-genotoxic effects of radiofrequency electromagnetic fields in vivo.

    Science.gov (United States)

    Verschaeve, L; Heikkinen, P; Verheyen, G; Van Gorp, U; Boonen, F; Vander Plaetse, F; Maes, A; Kumlin, T; Mäki-Paakkanen, J; Puranen, L; Juutilainen, J

    2006-05-01

    We investigated the possible combined genotoxic effects of radiofrequency (RF) electromagnetic fields (900 MHz, amplitude modulated at 217 Hz, mobile phone signal) with the drinking water mutagen and carcinogen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX). Female rats were exposed to RF fields for a period of 2 years for 2 h per day, 5 days per week at average whole-body specific absorption rates of 0.3 or 0.9 W/kg. MX was given in the drinking water at a concentration of 19 microg/ml. Blood samples were taken at 3, 6 and 24 months of exposure and brain and liver samples were taken at the end of the study (24 months). DNA damage was assessed in all samples using the alkaline comet assay, and micronuclei were determined in erythrocytes. We did not find significant genotoxic activity of MX in blood and liver cells. However, MX induced DNA damage in rat brain. Co-exposures to MX and RF radiation did not significantly increase the response of blood, liver and brain cells compared to MX exposure only. In conclusion, this 2-year animal study involving long-term exposures to RF radiation and MX did not provide any evidence for enhanced genotoxicity in rats exposed to RF radiation.

  6. Accessibility of shared space for visually impaired persons : A comparative field study

    NARCIS (Netherlands)

    Havik, Else; Steyvers, Franciscus J.J.M.; Kooijman, Aart; Melis, Bart

    2015-01-01

    Shared Space is a concept that comprises the design and planning process of a public space. There are concerns about the accessibility of Shared Spaces for people who are visually impaired. In a comparative field study, the wayfinding performance of 25 visually impaired persons (VIPs) was observed w

  7. Comparative and Mixture Effect of Cynodon Dactylon, ElectroMagnetic Field and Insulin on Diabetic Mouse

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Asghari

    2012-12-01

    Full Text Available Objective: New investigations are in progress to find some alternative treatments for diabetes mellitus. Herbs are some of the interesting medications in this regard. Cynodon dactylon (C.d is a potential plant to be considered as a new medication. On the other hand, the effect of the Electromagnetic Field (EMF on bio organisms is becoming clearer. In this study, the effect of C.d, EMF and insulin have been investigated on the diabetic mouse. Material and Methods: Diabetes was induced by a combination of ketamine (60 mg/Kg and xylazine (10 mg/Kg which induces a sustained hyperglycemia. Mice were divided into 12 groups: 1 control, 2 normal saline, 3 and 4 50mg/Kg C.d, 5 and 6 100 mg/Kg C.d, 7 insulin, 8 insulin and C.d, 9 EMF (110 KHz, 700±20 mG, 10 insulin and EMF, 11 EMF plus C.d and 12 insulin plus C.d and EMF. Blood glucose level was measured after 5 and 60 minutes in C.d administrated groups, and 5 minutes in the other groups by a glucometer set. The data were analyzed by ANOVA and different means were compared by Tukey and Bonferroni tests (p<0.05. Results: According to results, both dosages of C.d had significant lowering effect on blood glucose level. The first dose was more effective than the second, and its impact was just like insulin. The 6th, 9th and 10th groups were significant, also . However, they did not show a higher effect than insulin or C.d. The application of EMF had a significant effect compared to the second group, but it did not reduce the glucose level to the normal range. The effect of the 8th group was very impressive and the mean glucose levels in this group were lower than the control group. Conclusion: Considering the data, C.d is a good alternative medication for diabetes mellitus.

  8. Perceptions of Students in Primary Education Department Related to Children's Rights: A Comparative Investigation

    Science.gov (United States)

    Hareket, Erdem; Gülhan, Meryem

    2017-01-01

    This research was performed with the purpose of comparative investigation of perceptions which are related to child rights of the prospective primary school teachers' and pre-school teachers'. The research was designed properly to qualitative research approach. This research was performed with 80 the prospective primary school teachers and…

  9. A Comparative Structural Equation Modeling Investigation of the Relationships among Teaching, Cognitive and Social Presence

    Science.gov (United States)

    Kozan, Kadir

    2016-01-01

    The present study investigated the relationships among teaching, cognitive, and social presence through several structural equation models to see which model would better fit the data. To this end, the present study employed and compared several different structural equation models because different models could fit the data equally well. Among…

  10. Investigating the Development of Professional Learning Communities: Compare Schools in Shanghai and Southwest China

    Science.gov (United States)

    Zhang, Jia; Pang, Nicholas Sun-Keung

    2016-01-01

    This quantitative study investigated and compared the development of professional learning communities in schools located in two Chinese cities, namely, Shanghai and Mianyang. The two cities have significant differences in terms of educational, economic, social, and cultural development. While Shanghai is a directly controlled municipality in East…

  11. Comparing Child Protective Investigation Performance between Law Enforcement Agencies and Child Welfare Agencies

    Science.gov (United States)

    Jordan, Neil; Yampolskaya, Svetlana; Gustafson, Mara; Armstrong, Mary; McNeish, Roxann; Vargo, Amy

    2011-01-01

    This study examines the comparative effectiveness of using law enforcement agencies for child protective investigation (CPI), in contrast with the traditional approach of CPI conducted by the public child welfare agency. The analysis uses 2006-2007 data from a natural experiment conducted in Florida to show modest differences in performance and…

  12. Coupled cluster investigation of Sternheimer shieldings and electric field gradient polarizabilities

    Science.gov (United States)

    Coriani, Sonia; Halkier, Asger; Jørgensen, Poul; Gauss, Jürgen; Christiansen, Ove; Rizzo, Antonio

    2000-08-01

    A coupled cluster (CC) investigation is presented for the (generalized) Sternheimer shieldings and the electric field gradient (EFG) polarizabilities which describe the effect of external electric fields and field gradients on the electric field gradient at the nuclei. Calculations are performed for the linear molecules N2, CO, HF, C2H2, HCl, HCN, and HNC. Correlation effects are monitored by employing a hierarchy of CC models consisting of CCS, CC2, CCSD, and CC3. The effect of tight basis functions and core correlation is investigated by carrying out CCSD calculations with core-valence basis sets. Accurate theoretical estimates for EFGs, Sternheimer shieldings, and EFG polarizabilities are given and the effects of vibrational corrections are discussed. Our final estimates for the considered EFG properties can be used, for example, in simulations of electric field effects on the EFG at the nuclei in interacting molecules.

  13. Investigation of the Velocity Field and Flow Regime of David Glacier and Drygalski Ice Tongue, Antarctica

    Science.gov (United States)

    Wuite, J.; Jezek, K. C.

    2005-12-01

    Recent observations of outlet glaciers in both Greenland and Antarctica show surprising and unexpectedly rapid changes in flow velocities. Outlet glaciers drain the majority of the polar ice sheets and consequently these changes threaten their stability and can lead to rising sea levels. It is therefore important to investigate their flow governing processes and document changes. We measured surface velocity over large portions of David Glacier and its floating seaward extension Drygalski Ice Tongue. This is the largest outlet glacier on the Scott Coast draining a section of the East Antarctic Ice Sheet into the Ross Sea. Giant iceberg B15-A recently collided with the ice tongue and broke off a significant section. To obtain velocities we used combinations of intensity feature tracking, interferometric speckle tracking and phase interferometry using RADARSAT-1 images acquired during the AMM-1 and MAMM missions. We compare short term velocities, 3-year averaged velocities and earlier studies to analyze spatial and temporal variability of the surface velocity field. We use obtained velocities, in combination with isostatically derived ice thickness from ICESat data, to estimate basal melting along the glacier. Also we investigate the role of lateral drag through force-budget theory and determine the equilibrium profile of the ice tongue. Unlike for example the West Antarctic Ice Streams and Jakobshavn Isbrae, our data suggests that the David Glacier velocity field has remained relatively constant from about 1991 - 2000 and likely much longer. The pattern of melting and freezing along the base of the glacier is consistent with an ice pump mechanism. In the fjord lateral drag opposes approximately 90% of the driving stress; this gradually drops to the point where most resistance comes from longitudinal stress gradients. We find the modeled and ICESat derived profile agree favorably suggesting steady state conditions

  14. Investigation of the dimensionality of charge transport in organic field effect transistors

    Science.gov (United States)

    Abdalla, Hassan; Fabiano, Simone; Kemerink, Martijn

    2017-02-01

    Ever since the first experimental investigations of organic field effect transistors (OFETs) the dimensionality of charge transport has alternately been described as two dimensional (2D) and three dimensional (3D). More recently, researchers have turned to an analytical analysis of the temperature-dependent transfer characteristics to classify the dimensionality as either 2D or 3D as well as to determine the disorder of the system, thereby greatly simplifying dimensionality investigations. We applied said analytical analysis to the experimental results of our OFETs comprising molecularly well-defined polymeric layers as the active material as well as to results obtained from kinetic Monte Carlo simulations and found that it was not able to correctly distinguish between 2D and 3D transports or give meaningful values for the disorder and should only be used for quasiquantitative and comparative analysis. We conclude to show that the dimensionality of charge transport in OFETs is a function of the interplay between transistor physics and morphology of the organic material.

  15. Field investigations of the interaction between debris flows and forest vegetation in two Alpine fans

    Science.gov (United States)

    Michelini, Tamara; Bettella, Francesco; D'Agostino, Vincenzo

    2017-02-01

    A key objective in debris-flow hazard mitigation is the reduction of the potential depositional area in the fan. From this point of view, forested areas are able to provide a protective function hindering the flow motion and promoting the surge deposition. Despite extensive research on Alpine forests and their protective functions, relatively few studies in the literature have quantitatively focused on the relationship between debris-flow depositional features and vegetation. In light of the above, our research investigates how vegetation characteristics in the fan area interact with debris-flow deposition. Field investigations were carried out in two Alpine fans where debris-flow events occurred in the summer of 2012. By recording the characteristics of 1567 involved trees and the associated deposit thicknesses, this paper provides a data set that contributes to the improvement of the knowledge of these interaction processes. The integration of literature findings and the analysis of the collected dataset adds insights into the relationships between tree characteristics and the dynamics of debris flow during the runout path. The main results prove the capacity of the forest of uniformly promoting flow-energy dissipation, presence of high species diversity in debris-flow deposits when comparing disturbed and undisturbed forest stands, tree mortality largely affecting small diameters management of protection forests in alluvial fans are suggested.

  16. Comparing Hall Effect and Field Effect Measurements on the Same Single Nanowire.

    Science.gov (United States)

    Hultin, Olof; Otnes, Gaute; Borgström, Magnus T; Björk, Mikael; Samuelson, Lars; Storm, Kristian

    2016-01-13

    We compare and discuss the two most commonly used electrical characterization techniques for nanowires (NWs). In a novel single-NW device, we combine Hall effect and back-gated and top-gated field effect measurements and quantify the carrier concentrations in a series of sulfur-doped InP NWs. The carrier concentrations from Hall effect and field effect measurements are found to correlate well when using the analysis methods described in this work. This shows that NWs can be accurately characterized with available electrical methods, an important result toward better understanding of semiconductor NW doping.

  17. Comparative study of resonant and sequential features in electron field emission from composite surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Filip, Valeriu, E-mail: vfilip@gmail.com [Faculty of Physics, University of Bucharest, 405 Atomistilor Str., Magurele 077125, P.O. Box MG-11 (Romania); Institute of Microelectronics and Photonics, Zhejiang University, 38 Zheda Road, Hangzhou 310027 (China); Wong, Hei, E-mail: xiwang@zju.edu.cn [Institute of Microelectronics and Photonics, Zhejiang University, 38 Zheda Road, Hangzhou 310027 (China)

    2016-06-01

    A simple model of a layered hetero-structure was developed and used to simultaneously compute and compare resonant and sequential electron field emission currents. It was found that, while various slope changes appear in both current-field characteristics, for the sequential tunneling type of emission, such features are merely interference effects. They occur in parts of the structure, prior to the electrons' lingering in the quasi-bound states from which field emission proceeds. These purely quantum effects further combine with the flow effects resulting from the steady current requirement and give corresponding field variations of the electron population of the quasi-bound states, which further react on the resonant part of the current. A spectral approach of the two types of field emission is also considered by computing the total energy distribution of electrons in each case. The differences between these possible spectra are pointed out and discussed. - Highlights: • The relationship between resonant and sequential field emission is studied. • Sequential current–voltage characteristics show barrier-controlled undulations. • Resonant characteristics depend mainly on the width/shape of the topmost well. • The resonant and sequential total energy distributions differ widely.

  18. Investigation of electric field distribution on FAC-IR-300 ionization chamber

    Science.gov (United States)

    Mohammadi, S. M.; Tavakoli-Anbaran, H.; Zeinali, H. Z.

    2016-07-01

    One of the important parameters for establishing charge particle equilibrium (CPE) conditions of free-air ionization chamber is an electric field distribution. In this paper, electric field distribution inside the ionization chamber was investigated by finite element method. For this purpose, the effects of adding guard plate and guard strips on the electric field distribution in the ionization chamber were studied. it is necessary to apply a lead box around the ionization chamber body to avoid of scattered radiation effects on the ionization chamber operation, but the lead box changes the electric field distribution. In the following, the effect of lead box on the electric field distribution was studied. Finally, electric field distribution factor (kfield) was calculated by the simulation. The results of the simulation showed that presence of the guard plate and guard strips, and applying a suitable potential to lead box, a convergence of kfield to 1 was achieved.

  19. A Comparative Field Based Study of Katz and Barthel Indices in North Indian City of Dehradun

    Directory of Open Access Journals (Sweden)

    Megha Luthra

    2016-03-01

    Full Text Available Background: Elderly persons are one of the most vulnerable groups of society and have more chances of disease and disabilities (restriction or lack of ability to perform an activity in the manner or within the range considered normal for a human being. It reflects how well an individual is able to function in general areas of life. Magnitude of disability has become an important indicator in measuring disease burden along with morbidity and mortality rates. Katz and Barthel Indices have been largely used to assess disability in activities of daily living among elderly people.Aim & objectives: This community-based cross-sectional study was conducted among persons aged 60 years and above in urban field practice area of SGRRIM&HS, Dehradun, Uttarakhand with the aim of comparing these two indices in community setting. The specific objectives were to find ADL dependence by both the indices, find the factors which significantly affect ADL dependence and to find the degree of agreement which is not by chance between Katz and Barthel Indices.Material methods: An interview schedule was developed and administered to participants in Hindi, by trained investigators. Information on age, marital status, living status education, occupation and economic dependence was recorded. House-to-house visits were conducted in the selected area to collect the data. All elderly persons residing in the selected area were included in the study.Results: Prevalence of ADL dependence was 8.23% as per Katz Index and 28.45% as per Barthel Index, taking a score of less than 20 for BI and less than 6 for KI as criterion for ADL dependence. That there is a moderate degree of agreement between Katz and Barthel Scores which is not by chance was estimated by Kappa Statistic.Conclusion: Katz Index is better suited for ADL estimation in a community setting.

  20. Investigations About the Recording of the Palaeomagnetic Field in the Mono Basin, CA, in Siltstone from a Granitic Provenance

    Science.gov (United States)

    Liddicoat, Joseph; Coe, Robert

    2014-05-01

    For more than three decades, Reidar Lovlie did innovative laboratory and field experiments that advanced our understanding about how sediments acquire a remanent magnetization (Lovlie, 1979, and his subsequent publications about that research). The investigations we and our students have done with lacustrine sediments deposited during the late Pleistocene in the Mono Basin, CA, have benefited from those experiments. One of Lovlie's laboratory experiments that was especially useful in our investigation of the role of relative field intensity (RFI) during a rapidly changing field, the Mono Lake Excursion (MLE; Coe and Liddicoat, 1994), was his study of suspended magnetic grains in slowly curing epoxy resin as the field strength was varied (Lovlie, 1993). More recently we did comparative field and laboratory experiments with sediments from different depositional environments in the Mono Basin that help to explain the recording of the palaeomagnetic field in unweathered siltstone derived from a granitic provenance in the California Sierra Nevada. Our investigations are possible because inclination, declination, and RFI using alternating field and thermal demagnetization and intensity normalizing experiments of magnetic susceptibility (k), saturation isothermal remanent magnetization (SIRM), and anhysteretic remanent magnetization (ARM)(Lund et al., 2005) can be measured with precision for localities separated by as much as 15 kilometres using volcanic ash beds as marker horizons. In addition to making the comparison between localities in the Mono Basin that record the MLE, we have done that for a time interval following the MLE also in the Mono Basin where the palaeomagnetic directions are anomalous compared to secular variation (waveform Delta in Lund et al., 1988; Liddicoat and Coe, 2013). In that interval the RFI is nearly double the RFI during the MLE (Zimmerman et al., 2006), which again allows us to study RFI as a factor in the palaeomagnetic recording process in

  1. Numerical Investigation of Near-Field Plasma Flows in Magnetic Nozzles

    Science.gov (United States)

    Sankaran, Kamesh; Polzin, Kurt A.

    2009-01-01

    The development and application of a multidimensional numerical simulation code for investigating near-field plasma processes in magnetic nozzles are presented. The code calculates the time-dependent evolution of all three spatial components of both the magnetic field and velocity in a plasma flow, and includes physical models of relevant transport phenomena. It has been applied to an investigation of the behavior of plasma flows found in high-power thrusters, employing a realistic magnetic nozzle configuration. Simulation of a channel-flow case where the flow was super-Alfvenic has demonstrated that such a flow produces adequate back-emf to significantly alter the shape of the total magnetic field, preventing the flow from curving back to the magnetic field coil in the near-field region. Results from this simulation can be insightful in predicting far-field behavior and can be used as a set of self-consistent boundary conditions for far-field simulations. Future investigations will focus on cases where the inlet flow is sub-Alfvenic and where the flow is allowed to freely expand in the radial direction once it is downstream of the coil.

  2. Experimental Investigation of Pool Boiling Heat Transfer Enhancement in Microgravity in the Presence of Electric Fields

    Science.gov (United States)

    Herman, Cila

    1999-01-01

    In boiling high heat fluxes are possible driven by relatively small temperature differences, which make its use increasingly attractive in aerospace applications. The objective of the research is to develop ways to overcome specific problems associated with boiling in the low gravity environment by substituting the buoyancy force with the electric force to enhance bubble removal from the heated surface. Previous studies indicate that in terrestrial applications nucleate boiling heat transfer can be increased by a factor of 50, as compared to values obtained for the same system without electric fields. The goal of our research is to experimentally explore the mechanisms responsible for EHD heat transfer enhancement in boiling in low gravity conditions, by visualizing the temperature distributions in the vicinity of the heated surface and around the bubble during boiling using real-time holographic interferometry (HI) combined with high-speed cinematography. In the first phase of the project the influence of the electric field on a single bubble is investigated. Pool boiling is simulated by injecting a single bubble through a nozzle into the subcooled liquid or into the thermal boundary layer developed along the flat heater surface. Since the exact location of bubble formation is known, the optical equipment can be aligned and focused accurately, which is an essential requirement for precision measurements of bubble shape, size and deformation, as well as the visualization of temperature fields by HI. The size of the bubble and the frequency of bubble departure can be controlled by suitable selection of nozzle diameter and mass flow rate of vapor. In this approach effects due to the presence of the electric field can be separated from effects caused by the temperature gradients in the thermal boundary layer. The influence of the thermal boundary layer can be investigated after activating the heater at a later stage of the research. For the visualization experiments a

  3. Forcing a unitary transformation by an external field comparing two approaches based on optimal control theory

    CERN Document Server

    Palao, J P; Palao, Jose P.; Kosloff, Ronnie

    2002-01-01

    A quantum gate is realized by specific unitary transformations operating on states representing qubits. Considering a quantum system employed as an element in a quantum computing scheme, the task is therefore to enforce the pre-specified unitary transformation. This task is carried out by an external time dependent field. Optimal control theory has been suggested as a method to compute the external field which alters the evolution of the system such that it performs the desire unitary transformation. This study compares two recent implementations of optimal control theory to find the field that induces a quantum gate. The first approach is based on the equation of motion of the unitary transformation. The second approach generalizes the state to state formulation of optimal control theory. This work highlight the formal relation between the two approaches.

  4. 3D-QSAR studies on glycogen phosphorylase inhibitors by flexible comparative molecular field analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Canceling grids accommodating probes in comparative molecular field analysis (CoMFA), the idea of flexibleness is introduced into the CoMFA, and in combination with swarm intelligent algorithm which attempts to optimize distributions of diverse probes around drug molecules, a new 3D-QSAR method is proposed in this context as flexible comparative molecular field analysis (FCoMFA). In preliminary at-tempts to performing QSAR studies on 47 glycogen phosphorylase inhibitors, FCoMFA is employed and confirmed to be potent to exploring ligand-receptor interaction manners at active positions and thus to generating stable and predictable models. Simultaneously by an intuitive graphics regarding probe distribution patterns, impacts of different substituted groups on activities is also given an insight into.

  5. 3D-QSAR studies on glycogen phosphorylase inhibitors by flexible comparative molecular field analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Peng; LI ZhiLiang

    2007-01-01

    Canceling grids accommodating probes in comparative molecular field analysis (CoMFA), the idea of flexibleness is introduced into the CoMFA, and in combination with swarm intelligent algorithm which attempts to optimize distributions of diverse probes around drug molecules, a new 3D-QSAR method is proposed in this context as flexible comparative molecular field analysis (FCoMFA). In preliminary attempts to performing QSAR studies on 47 glycogen phosphorylase inhibitors, FCoMFA is employed and confirmed to be potent to exploring ligand-receptor interaction manners at active positions and thus to generating stable and predictable models. Simultaneously by an intuitive graphics regarding probe distribution patterns, impacts of different substituted groups on activities is also given an insight into.

  6. Geologic guide to the island of Hawaii: A field guide for comparative planetary geology

    Science.gov (United States)

    Greeley, R. (Editor)

    1974-01-01

    With geological data available for all inner planets except Venus, we are entering an era of true comparative planetary geology, when knowledge of the differences and similarities for classes of structures (e.g., shield volcanoes) will lead to a better understanding of general geological processes, regardless of planet. Thus, it is imperative that planetologists, particularly those involved in geological mapping and surface feature analysis for terrestrial planets, be familiar with volcanic terrain in terms of its origin, structure, and morphology. One means of gaining this experience is through field trips in volcanic terrains - hence, the Planetology Conference in Hawaii. In addition, discussions with volcanologists at the conference provide an important basis for establishing communications between the two fields that will facilitate comparative studies as more data become available.

  7. Comparative investigation on the removal of cyanide from aqueous solution using two different bioadsorbents

    OpenAIRE

    Naveen Dwivedi; Chandrajit Balomajumder; Prasenjit Mondal

    2016-01-01

    In the present study, comparative investigation for the bioremoval of cyanide from synthetic aqueous solution by Prunus amygdalus (Almond) shell (PAS) and Tectona grandis (Sagwan) leaves (TGL) powder have been performed as a function of solution pH, bioadsorbent dose, contact time and initial cyanide concentration. The cyanide uptake by PAS and TGL powder has been quantitatively estimated using sorption isotherms. The equilibrium data are best fitted to Freundlich and Langmuir isotherm model ...

  8. Experimental Investigation of Effectiveness of Magnetic Field on Food Freezing Process

    Science.gov (United States)

    Suzuki, Toru; Takeuchi, Yuri; Masuda, Kazunori; Watanabe, Manabu; Shirakashi, Ryo; Fukuda, Yutaka; Tsuruta, Takaharu; Yamamoto, Kazutaka; Koga, Nobumitsu; Hiruma, Naoya; Ichioka, Jun; Takai, Kiyoshi

    Recently, several food refrigeration equipments that utilize magnetic field have attracted much attention from food production companies, consumers and mass media. However, the effectiveness of the freezers is not scientifically examined. Therefore, the effectiveness should be clarified by experiments or theoretical considerations. In this study, the effect of weak magnetic field (about 0.0005 T) on freezing process of several kinds of foods was investigated by using a specially designed freezer facilitated with magnetic field generator. The investigation included the comparison of freezing curves, drip amount, physicochemical evaluations on color and texture, observation of microstructure, and sensory evaluation. From the results of the control experiments, it can be concluded that weak magnetic field around 0.0005 T provided no significant difference on temperature history during freezing and on the qualities of frozen foods, within our experimental conditions.

  9. Experimental investigation of the influence of electric field on frost layer growth under natural convection condition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The influence of direct current (DC) electric field on the thickness and mass of frost on a cold vertical plate was investigated. The photos of frost layer growth were taken with and without the presence of electric field, and results showed that the electric field has a strong influence on the frost thickness. The influences of cold plate temperature and ambient temperature on frost thickness and frost mass were also investigated under the natural convection condition with electric field. Experimental results demonstrated that the cold plate temperature has very strong effect on the frost layer thickness, but its influence on frost mass is minor; the influence of ambient temperature on the frost mass is more obvious than that on the frost thickness.

  10. A PILOT STUDY COMPARING TWO FIELD TESTS WITH THE TREADMILL RUN TEST IN SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Abdul Rashid Aziz

    2005-06-01

    Full Text Available This study compares the performances obtained during soccer-specific field tests of the 20 m multistage shuttle run test (MST and the Yo-Yo intermittent endurance test (YIET, with the measured maximal oxygen uptake (VO2max obtained in both field tests as well as that obtained in the traditional test of running to exhaustion on a treadmill (TRT, in young trained soccer players. Twenty-one National-level youth players performed, in random order, the MST and YIET to determine the relationship between the two field tests. From these, eight randomly chosen players performed their field tests as well as a TRT, equipped with an ambulatory gas exchange measurement device. Pearson correlation coefficient analysis showed that the players' performance (i.e. distance covered in the MST and YIET was correlated (r = 0.65, p 0.05. In contrast, significant correlations were observed between the players' performance in the MST with the measured VO2max obtained in the same MST and in the YIET (both p < 0.05; and attained almost statistical significance with the measured VO2max in the TRT (p = 0.06. The lack of association between distances covered in the YIET with all the measured VO2max values suggest that measured VO2max per se may not be suitable to characterize soccer players' intermittent endurance performance. In comparison with the MST, the YIET may be a more favourable field-based assessment of soccer player's endurance performance

  11. Electric field measurements on Cluster: comparing the double-probe and electron drift techniques

    Directory of Open Access Journals (Sweden)

    A. I. Eriksson

    2006-03-01

    Full Text Available The four Cluster satellites each carry two instruments designed for measuring the electric field: a double-probe instrument (EFW and an electron drift instrument (EDI. We compare data from the two instruments in a representative sample of plasma regions. The complementary merits and weaknesses of the two techniques are illustrated. EDI operations are confined to regions of magnetic fields above 30 nT and where wave activity and keV electron fluxes are not too high, while EFW can provide data everywhere, and can go far higher in sampling frequency than EDI. On the other hand, the EDI technique is immune to variations in the low energy plasma, while EFW sometimes detects significant nongeophysical electric fields, particularly in regions with drifting plasma, with ion energy (in eV below the spacecraft potential (in volts. We show that the polar cap is a particularly intricate region for the double-probe technique, where large nongeophysical fields regularly contaminate EFW measurments of the DC electric field. We present a model explaining this in terms of enhanced cold plasma wake effects appearing when the ion flow energy is higher than the thermal energy but below the spacecraft potential multiplied by the ion charge. We suggest that these conditions, which are typical of the polar wind and occur sporadically in other regions containing a significant low energy ion population, cause a large cold plasma wake behind the spacecraft, resulting in spurious electric fields in EFW data. This interpretation is supported by an analysis of the direction of the spurious electric field, and by showing that use of active potential control alleviates the situation.

  12. Magnetic investigation of zero-field-cooled dextran-coated magnetite-based magnetic fluid

    Energy Technology Data Exchange (ETDEWEB)

    Morais, P.C. [Universidade de Brasilia, Instituto de Fisica, Fisica Aplicada, C.P. 004455, Campus Universitario, Brasilia-DF 70919 970 (Brazil)]. E-mail: pcmor@unb.br; Santos, J.G. [Universidade de Brasilia, Instituto de Fisica, Fisica Aplicada, C.P. 004455, Campus Universitario, Brasilia-DF 70919 970 (Brazil); Silveira, L.B. [Universidade de Brasilia, Instituto de Fisica, Fisica Aplicada, C.P. 004455, Campus Universitario, Brasilia-DF 70919 970 (Brazil); Nunes, W.C. [Universidade Federal doRio de Janeiro, Instituto de Fisica, 21945-970, Rio de Janeiro-RJ (Brazil); Sinnecker, J.P. [Universidade Federal doRio de Janeiro, Instituto de Fisica, 21945-970, Rio de Janeiro-RJ (Brazil); Novak, M.A. [Universidade Federal doRio de Janeiro, Instituto de Fisica, 21945-970, Rio de Janeiro-RJ (Brazil)

    2005-03-15

    In this study, we investigate the temperature dependence of the zero-field-cooled magnetization of a quasi-monodisperse dextran-coated magnetite-based magnetic fluid. The well-defined maximum in the magnetization versus temperature curve and its downshift with the applied external field is explained by a simple model considering thermally activated dynamics of the nanoparticles magnetic moment and the temperature dependence of the saturation magnetization.

  13. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 3: Ecological risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hlohowskyj, I.; Hayse, J.; Kuperman, R.; Van Lonkhuyzen, R.

    2000-02-25

    The Environmental Management Division of the U.S. Army Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation (RI) and feasibility study (FS) of the J-Field area at APG, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of that activity, Argonne National Laboratory (ANL) conducted an ecological risk assessment (ERA) of the J-Field site. This report presents the results of that assessment.

  14. Experimental investigation of local properties and statistics of optical vortices in random wave fields

    DEFF Research Database (Denmark)

    Wang, W.; Hanson, Steen Grüner; Miyamoto, Y.;

    2005-01-01

    We present the first direct experimental evidence of the local properties of optical vortices in a random laser speckle field. We have observed the Berry anisotropy ellipse describing the anisotropic squeezing of phase lines close to vortex cores and quantitatively verified the Dennis angular...... momentum rule for its phase. Some statistics associated with vortices, such as density, anisotropy ellipse eccentricity, and its relation to zero crossings of real and imaginary parts of the random field, are also investigated by experiments....

  15. Investigation of the Decelerating Field of an Electron Multiplier under Negative Ion Impact

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Kjeldgaard, K.

    1973-01-01

    The effect of the decelerating field of an electron multiplier towards negative ions was investigated under standard mass spectrometric conditions. Diminishing of this decelerating field by changing of the potential of the electron multiplier increased the overall sensitivity to negative ions...... by a factor of 100. The secondary electron emission coefficient for the negative halogen ions relative to I− were measured on CuBe at the kinetic energies 1.0 and 1.5 keV....

  16. Investigations of scattering and field enhancement effects in retardation-based plasmonic nanoantennas

    DEFF Research Database (Denmark)

    Nielsen, M. G.; Pors, A.; Nielsen, Rasmus Bundgaard;

    2010-01-01

    Modifications in scattering strength of and local field enhancement by retardation-based plasmonic nanoantennas when being transformed from straight nanorods to split-rings are investigated. The scattering properties are monitored by linear reflection and extinction spectroscopy whereas local field......, a feature that we attribute to the decrease in the nanoantenna electric-dipole response in tact with its bending. The experimental observations are corroborated with numerical simulations using the finite-element method....

  17. Comparative meta-analysis of tuberculosis contact investigation interventions in eleven high burden countries.

    Science.gov (United States)

    Blok, Lucie; Sahu, Suvanand; Creswell, Jacob; Alba, Sandra; Stevens, Robert; Bakker, Mirjam I

    2015-01-01

    Screening of household contacts of tuberculosis (TB) patients is a recommended strategy to improve early case detection. While it has been widely implemented in low prevalence countries, the most optimal protocols for contact investigation in high prevalence, low resource settings is yet to be determined. This study evaluated contact investigation interventions in eleven lower and middle income countries and reviewed the association between context or program-related factors and the yield of cases among contacts. We reviewed data from nineteen first wave TB REACH funded projects piloting innovations to improve case detection. These nineteen had fulfilled the eligibility criteria: contact investigation implementation and complete data reporting. We performed a cross-sectional analysis of the percentage yield and case notifications for each project. Implementation strategies were delineated and the association between independent variables and yield was analyzed by fitting a random effects logistic regression. Overall, the nineteen interventions screened 139,052 household contacts, showing great heterogeneity in the percentage yield of microscopy confirmed cases (SS+), ranging from 0.1% to 6.2%). Compared to the most restrictive testing criteria (at least two weeks of cough) the aOR's for lesser (any TB related symptom) and least (all contacts) restrictive testing criteria were 1.71 (95%CI 0.94-3.13) and 6.90 (95% CI 3.42-13.93) respectively. The aOR for inclusion of SS- and extra-pulmonary TB was 0.31 (95% CI 0.15-0.62) compared to restricting index cases to SS+ TB. Contact investigation contributed between <1% and 14% to all SS+ cases diagnosed in the intervention areas. This study confirms that high numbers of active TB cases can be identified through contact investigation in a variety of contexts. However, design and program implementation factors appear to influence the yield of contact investigation and its concomitant contribution to TB case detection.

  18. Comparative meta-analysis of tuberculosis contact investigation interventions in eleven high burden countries.

    Directory of Open Access Journals (Sweden)

    Lucie Blok

    Full Text Available Screening of household contacts of tuberculosis (TB patients is a recommended strategy to improve early case detection. While it has been widely implemented in low prevalence countries, the most optimal protocols for contact investigation in high prevalence, low resource settings is yet to be determined. This study evaluated contact investigation interventions in eleven lower and middle income countries and reviewed the association between context or program-related factors and the yield of cases among contacts.We reviewed data from nineteen first wave TB REACH funded projects piloting innovations to improve case detection. These nineteen had fulfilled the eligibility criteria: contact investigation implementation and complete data reporting. We performed a cross-sectional analysis of the percentage yield and case notifications for each project. Implementation strategies were delineated and the association between independent variables and yield was analyzed by fitting a random effects logistic regression.Overall, the nineteen interventions screened 139,052 household contacts, showing great heterogeneity in the percentage yield of microscopy confirmed cases (SS+, ranging from 0.1% to 6.2%. Compared to the most restrictive testing criteria (at least two weeks of cough the aOR's for lesser (any TB related symptom and least (all contacts restrictive testing criteria were 1.71 (95%CI 0.94-3.13 and 6.90 (95% CI 3.42-13.93 respectively. The aOR for inclusion of SS- and extra-pulmonary TB was 0.31 (95% CI 0.15-0.62 compared to restricting index cases to SS+ TB. Contact investigation contributed between <1% and 14% to all SS+ cases diagnosed in the intervention areas.This study confirms that high numbers of active TB cases can be identified through contact investigation in a variety of contexts. However, design and program implementation factors appear to influence the yield of contact investigation and its concomitant contribution to TB case detection.

  19. Investigation on magnetic field dependent modulus of epoxidized natural rubber based magnetorheological elastomer

    Science.gov (United States)

    Yunus, N. A.; Mazlan, S. A.; Ubaidillah; Aziz, S. A. A.; Khairi, M. H. Ahmad; Wahab, N. A. A.; Shilan, S. T.

    2016-11-01

    This paper presents an investigation on the use of epoxidized natural rubber (ENR) as a matrix of magnetorheological elastomers (MREs). Isotropic ENR-based MRE samples were synthesized by homogeneously mixed the ENR compound with carbonyl iron particles (CIPs). The microstructure of the sample was observed, and the magnetic field-dependent moduli were analyzed using rheometer. The influences of excitation frequency, CIPs content and magnetic field on the field-dependent moduli of ENR-based MREs were evaluated through dynamic shear test. The microstructure of MRE samples demonstrated the dispersed CIPs in the ENR matrix. The remarkable increment of storage and loss moduli of the ENR-based MREs has exhibited the magnetically controllable storage and loss moduli of the samples when exposed to the magnetic field. Consequently, the CIPs content, frequency and magnetic field were significantly influenced the dynamic moduli of the ENR-based MREs.

  20. Green's function formalism in semi-infinite composites: an investigation of local field distribution

    Science.gov (United States)

    Li, Chen; Gu, Ying; Dai, Bing; Gong, Qi-Huang

    2004-11-01

    In the resonant composites, the formerly developed Green's function formalism (GFF) can be used to compute the local field distribution near resonance. In this paper, we extend the GFF in the infinite network to the semi-infinite networks by the method of image. Using the formalism, we investigate the local field distribution near resonance for the impurity clusters with admittance epsilon0 embedded in one semi-infinite network with epsilon1. With varying the admittance epsilon2 of another semi-infinite network, we find that the local fields in the boundary experience great changes, especially at epsilon2 = -epsilon1. The existence of the boundary enhances the localization of the fields within and around the metallic clusters. Therefore, the intensity of local field is influenced by the arrangement of impurity metallic bonds and its distance from the boundary.

  1. Green's function formalism in semi-infinite composites:an investigation of local field distribution

    Institute of Scientific and Technical Information of China (English)

    Li Chen; Gu Ying; Dai Bing; Gong Qi-Huang

    2004-01-01

    In the resonant composites, the formerly developed Green's function formalism (GFF) can be used to compute the local field distribution near resonance. In this paper, we extend the GFF in the infinite network to the semi-infinite networks by the method of image. Using the formalism, we investigate the local field distribution near resonance for the impurity clusters with admittance ∈0 embedded in one semi-infinite network with ∈1. With varying the admittance ∈2 of another semi-infinite network, we find that the local fields in the boundary experience great changes, especially at ∈2= -∈1. The existence of the boundary enhances the localization of the fields within and around the metallic clusters.Therefore, the intensity of local field is influenced by the arrangement of impurity metallic bonds and its distance from the boundary.

  2. Investigation of spatial distribution of radiocesium in a paddy field as a potential sink.

    Directory of Open Access Journals (Sweden)

    Kazuya Tanaka

    Full Text Available Surface soils, under various land uses, were contaminated by radionuclides that were released by the Fukushima Daiichi Nuclear Power Plant accident. Because paddy fields are one of the main land uses in Japan, we investigated the spatial distribution of radiocesium and the influence of irrigation water in a paddy field during cultivation. Soil core samples collected at a paddy field in Fukushima showed that plowing had disturbed the original depth distribution of radiocesium. The horizontal distribution of radiocesium did not show any evidence for significant influence of radiocesium from irrigation water, and its accumulation within the paddy field, since the original amount of radiocesium was much larger than was added into the paddy field by irrigation water. However, it is possible that rainfall significantly increases the loading of radiocesium.

  3. The Investigation of Field Plate Design in 500 V High Voltage NLDMOS

    Directory of Open Access Journals (Sweden)

    Donghua Liu

    2015-01-01

    Full Text Available This paper presents a 500 V high voltage NLDMOS with breakdown voltage (VBD improved by field plate technology. Effect of metal field plate (MFP and polysilicon field plate (PFP on breakdown voltage improvement of high voltage NLDMOS is studied. The coeffect of MFP and PFP on drain side has also been investigated. A 500 V NLDMOS is demonstrated with a 37 μm drift length and optimized MFP and PFP design. Finally the breakdown voltage 590 V and excellent on-resistance performance (Rsp = 7.88 ohm * mm2 are achieved.

  4. Optical investigation of effective permeability of dilute magnetic dielectrics with magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Ananya, E-mail: banerjee.ananya2008@gmail.com; Sarkar, A. [Dept. of Physics, Bijoy Krishna Girls’ College, 5/3 M.G. Road, Howrah 711101, W.B. (India)

    2016-05-06

    The prime objective of this paper is to investigate the magnetic nature of dilute magnetic dielectrics (DMD) under variation of external magnetic field. The said variation is studied over developed nano-sized Gadolinium Oxide as a DMD system. The observed experimental field variation of the effective magnetic permeability is analyzed results of optical experiment. The experiment records the variation of Brewster angle of incident polarized LASER beam from the surface of developed DMD specimen with applied out of plane external magnetic field. The effective refractive index and hence relative magnetic permeability were estimated following electro-magnetic theory. The overall results obtained and agreement between theory and experiment are good.

  5. Investigation of different magnetic field configurations using an electrical, modular Zeeman slower

    Energy Technology Data Exchange (ETDEWEB)

    Ohayon, Ben; Ron, Guy, E-mail: gron@racah.phys.huji.ac.il [Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

    2015-10-15

    We present a method of constructing an automatically reconfigurable, modular, electronic Zeeman slower, which is remotely controlled. This setup is used to investigate the ability of different magnetic field profiles to slow thermal atoms to the capture velocity of a magneto-optical-trap. We show that a simple numerical optimization process yields better results than the commonly used approach for deciding on the appropriate field and comes close to the optimum field, found by utilizing a fast feedback loop which uses a genetic algorithm. Our new numerical method is easily adaptable to a variety of existing slower designs and may be beneficial where feedback is unavailable.

  6. Sources of the Geomagnetic Field and theModern Data That Enable Their Investigation

    DEFF Research Database (Denmark)

    Olsen, Nils; Hulot, Gauthier; Sabaka, Terence J.

    2010-01-01

    Abstract The geomagnetic field one canmeasure at the Earth’s surface or on board satellites is the sumof contributions frommany different sources.These sources have different physical origins and can be found both below (in the form of electrical currents and magnetized material) and above (only...... sets are available and analyzed in an adequate way, to produce the so-called geomagnetic field models.Here a general overview of the various sources that contribute to the observed geomagnetic field, and of the modern data that enable their investigation via such procedures is provided....

  7. Field emission properties of capped carbon nanotubes doped by alkali metals:a theoretical investigation

    Institute of Scientific and Technical Information of China (English)

    Jin Lei; Fu Hong-Gang; Xie Ying; Yu Hai-Tao

    2012-01-01

    The electronic structures and field emission properties of capped CNT55 systems with or without alkali metal atom adsorption were systematically investigated by density functional theory calculation.The results indicate that the adsorption of alkali metal on the center site of a CNT tip is energetically favorable.In addition,the adsorption energies increase with the introduction of the electric field.The excessive negative charges on CNT tips make electron emittance much easier and result in a decrease in work function.Furthermore,the inducing effect by positively charged alkali metal atoms can be reasonably considered as the dominant reason for the improvement in field emission properties.

  8. Theoretical investigation of boundary contours of ground-state atoms in uniform electric fields

    Science.gov (United States)

    Shi, Hua; Zhao, Dong-Xia; Yang, Zhong-Zhi

    2015-12-01

    The boundary contours were investigated for first 54 ground-state atoms of the periodic table when they are in uniform electric fields of strengths 106, 107 and 108 V/m. The atomic characteristic boundary model in combination with an ab-initio method was employed. Some regularities of the deformation of atoms, ΔR, in above electric fields are revealed. Furthermore, atomic polarisabilities of the first 54 elements of the periodic table are shown to correlate strongly with the mean variation rate of atomic radial size divided by the strength of the electric field F, ?, which provides a predictive method of calculating atomic polarisabilities of 54 atoms.

  9. Investigation of a direct effect of nanosecond pulse electric fields on mitochondria

    Science.gov (United States)

    Estlack, Larry E.; Roth, Caleb C.; Cerna, Cesario Z.; Wilmink, Gerald J.; Ibey, Bennett L.

    2014-03-01

    The unique cellular response to nanosecond pulsed electric field (nsPEF) exposure, as compared to longer pulse exposure, has been theorized to be due to permeabilization of intracellular organelles including the mitochondria. In this investigation, we utilized a high-throughput oxygen and pH sensing system (Seahorse® XF24 extracellular flux analyzer) to assess the mitochondrial activity of Jurkat and U937 cells after nsPEF. The XF Analyzer uses a transient micro-chamber of only a few μL in specialized cell culture micro-plates to enable oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) to be monitored in real-time. We found that for nsPEF exposures of 10 pulses at 10-ns pulse width and at 50 kV/cm e-field, we were able to cause an increase in OCR in both U937 and Jurkat cells. We also found that high pulse numbers (>100) caused a significant decrease in OCR. Higher amplitude 150 kV/cm exposures had no effect on U937 cells and yet they had a deleterious effect on Jurkat cells, matching previously published 24 hour survival data. These results suggest that the exposures were modulating metabolic activity in cells possibly due to direct effects on the mitochondria themselves. To validate this hypothesis, we isolated mitochondria from U937 cells and exposed them similarly and found no significant change in metabolic activity for any pulse number. In a final experiment, we removed calcium from the buffer solution that the cells were exposed in and found that no significant enhancement in metabolic activity was observed. These results suggest that direct permeabilization of the mitochondria is unlikely a primary effect of nsPEF exposure and calcium-mediated intracellular pathway activation is likely responsible for observed pulse-induced mitochondrial effects.

  10. Investigation of the isoplanatic patch and wavefront aberration along the pupillary axis compared to the line of sight in the eye

    OpenAIRE

    Nowakowski, Maciej; Sheehan, Matthew; Neal, Daniel; Goncharov, Alexander V.

    2012-01-01

    Conventional optical systems usually provide best image quality on axis, while showing unavoidable gradual decrease in image quality towards the periphery of the field. The optical system of the human eye is not an exception. Within a limiting boundary the image quality can be considered invariant with field angle, and this region is known as the isoplanatic patch. We investigate the isoplanatic patch of eight healthy eyes and measure the wavefront aberration along the pupillary axis compared...

  11. Dynamic behavior of a direct expansion evaporator under frosting condition. Part II. Field investigation on a shipping container

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.P. [Multimedia University, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore 634798 (Singapore). School of Mechanical and Aerospace Engineering

    2006-06-15

    A field investigation is performed on the frost formation at an evaporator of a commercial full-scale refrigerated container that uses R-12 as the working refrigerant. Results when compared with those from a numerical model presented earlier show that the model is capable of predicting the dynamic behavior of a direct expansion evaporator under both non-frosting and frosting conditions. The air outlet and energy transferred compare well between experiment and model, and within 20% for the air pressure drop. The frost occurrence and propagation agree well generally, with the frost formation first occurring at the first row where the refrigerant enters the evaporator. (author)

  12. Quartz luminescence response to a mixed alpha-beta field: Investigations on Romanian loess

    DEFF Research Database (Denmark)

    Constantin, Daniela; Jain, Mayank; Murray, Andrew S.

    2015-01-01

    Previous SAR-OSL dating studies using quartz extracted from Romanian and Serbian loess samples report SAR-OSL dose-response curves on fine grained (4-11μm) quartz that grow to much higher doses compared to those of coarse-grained (63-90, 90-125, 125-180μm) quartz. Furthermore, quartz SAR......-OSL laboratory dose response curves do not reflect the growth of the OSL signal in nature. A main difference in coarse- and fine-grained quartz dating lies in the alpha irradiation history, but the effect of mixed alpha-beta fields has so far received little attention. In the present study we investigate whether...... radiation follow the same recombination path. We also show that a mixed alpha-beta dose response reproduces the beta dose response only up to about 800Gy. Assuming an a-value of 0.04 we have shown that laboratory alpha and beta dose response curves overlap up to effective alpha doses of ~50Gy. Based...

  13. Ligula intestinalis (Cestoda: Diphyllobothriidae) in Kenya: a field investigation into host specificity and behavioural alterations.

    Science.gov (United States)

    Britton, J R; Jackson, M C; Harper, D M

    2009-09-01

    Within the distribution of Ligula intestinalis, a tapeworm affecting freshwater fishes, there are genetically distinct and well-separated phylogenetic clusters. East Africa is represented by a single monophyletic clade which is understudied compared with Euro-Mediterranean clades. The present field investigation in the Lake Baringo and Naivasha catchments, Kenya, revealed that this L. intestinalis clade was highly host-specific, present in only 2 of 12 fishes examined; Barbus paludinosus in Naivasha and Barbus lineomaculatus in Baringo. In infected fish, cestodes comprised up to 20% of body weight. Only 1 parasite was recorded per fish, a contrast to infected fishes in Europe where mixed infections are commonplace. In B. lineomaculatus in Baringo, only fish of greater than 64 mm in length were parasitized. The highest parasite prevalence was recorded in fish of 70-77 mm in length, and reduced for lengths of 78-84 mm. Parasitized fish were significantly associated with a particular type of habitat, occurring most frequently in shallow littoral areas, and being absent from open water and rocky shore habitats. Uninfected fish were present in all habitats. This relationship between spatial occupancy and parasite prevalence is suggested to arise from behavioural alterations induced by the parasite that promotes completion of the parasite life cycle.

  14. Comparative molecular field analysis of quinoline derivatives as selective and noncompetitive mGluR1 antagonists.

    Science.gov (United States)

    Sekhar, Y Nataraja; Nayana, M Ravi Shashi; Ravikumar, Muttineni; Mahmood, S K

    2007-12-01

    A 3D- QSAR model os Comparative Molecular Field Analysib (CoMFA) of 45 quinoline derivatives as metaborropic glutamate receptor subtype 1 (mGluR1) inhibitors wew investigated. The CoMFA analysis provided a model with q(2) value of 0.827 and r(2) value of 0.990, in which q(2) value of 0.827 and an r(2) value of 0.990, in which the good correlation between the inhibitory activities and the steric and electrostatic molecular field around the analoques was observed. The predictive ability of the models was validated using the set of 12 compounds that were not included in the training set of 33 compounds. These results provided further understanding of the relationship between the structural features of quinolone derivatives and its activities, which should be applicable to design and find new potential mGluR1 inhibitors.

  15. Properties of the vacuum in models for QCD. Holography vs. resummed field theory. A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Zayakin, Andrey V.

    2011-01-17

    This Thesis is dedicated to a comparison of the two means of studying the electromagnetic properties of the QCD vacuum - holography and resummed field theory. I compare two classes of distinct models for the dynamics of the condensates. The first class consists of the so-called holographic models of QCD. Based upon the Maldacena conjecture, it tries to establish the properties of QCD correlation functions from the behavior of classical solutions of field equations in a higher-dimensional theory. Yet in many aspects the holographic approach has been found to be in an excellent agreement with data. These successes are the prediction of the very small viscosity-to-entropy ratio and the predictions of meson spectra up to 5% accuracy in several models. On the other hand, the resummation methods in field theory have not been discarded so far. Both classes of methods have access to condensates. Thus a comprehensive study of condensates becomes possible, in which I compare my calculations in holography and resummed field theory with each other, as well as with lattice results, field theory and experiment. I prove that the low-energy theorems of QCD keep their validity in holographic models with a gluon condensate in a non-trivial way. I also show that the so-called decoupling relation holds in holography models with chiral and gluon condensates, whereas this relation fails in the Dyson-Schwinger approach. On the contrary, my results on the chiral magnetic effect in holography disagree with the weak-field prediction; the chiral magnetic effect (that is, the electric current generation in a magnetic field) is three times less than the current in the weakly-coupled QCD. The chiral condensate behavior is found to be quadratic in external field both in the Dyson-Schwinger approach and in holography, yet we know that in the exact limit the condensate must be linear, thus both classes of models are concluded to be deficient for establishing the correct condensate behaviour in the

  16. Comparative Transcriptomic Approach To Investigate Differences in Wine Yeast Physiology and Metabolism during Fermentation▿ †

    Science.gov (United States)

    Rossouw, Debra; Olivares-Hernandes, Roberto; Nielsen, Jens; Bauer, Florian F.

    2009-01-01

    Commercial wine yeast strains of the species Saccharomyces cerevisiae have been selected to satisfy many different, and sometimes highly specific, oenological requirements. As a consequence, more than 200 different strains with significantly diverging phenotypic traits are produced globally. This genetic resource has been rather neglected by the scientific community because industrial strains are less easily manipulated than the limited number of laboratory strains that have been successfully employed to investigate fundamental aspects of cellular biology. However, laboratory strains are unsuitable for the study of many phenotypes that are of significant scientific and industrial interest. Here, we investigate whether a comparative transcriptomics and phenomics approach, based on the analysis of five phenotypically diverging industrial wine yeast strains, can provide insights into the molecular networks that are responsible for the expression of such phenotypes. For this purpose, some oenologically relevant phenotypes, including resistance to various stresses, cell wall properties, and metabolite production of these strains were evaluated and aligned with transcriptomic data collected during alcoholic fermentation. The data reveal significant differences in gene regulation between the five strains. While the genetic complexity underlying the various successive stress responses in a dynamic system such as wine fermentation reveals the limits of the approach, many of the relevant differences in gene expression can be linked to specific phenotypic differences between the strains. This is, in particular, the case for many aspects of metabolic regulation. The comparative approach therefore opens new possibilities to investigate complex phenotypic traits on a molecular level. PMID:19700545

  17. Comparative sessile drop and dip pen nanolithography investigation for various hydrophilic ink/surface systems.

    Science.gov (United States)

    Yadav, Pradeep K; Lemoine, Patrick

    2012-01-01

    We present a dip pen nanolithography study of various hydrophilic ink/surface systems with application in the field of biosensors and novel nano-materials. The inking process was investigated by studying a number of inks, such as Deoxyribonucleic acid (DNA), Bovine serum albumin (BSA), Streptavidin, 16-mercaptohexadecanoic acid (MHA) and a 20 nm nanosphere (NS) polystyrene solution onto a range of substrates, namely glass, silicon, gold and tetrahedral amorphous carbon (taC). In the majority of cases, this resulted in patterns with sub-100 nm line widths and dot diameters. Importantly, contact angle measurements in the microl range showed a decrease of contact angle with drop volume, interpreted as a line tension effect. The significance of this to the nanoscale wetting behaviour is discussed. The effect of dwell time and writing speed indicates that the inking process is not solely defined by surface diffusion but also influenced by the ink dissolution rate from the tip.

  18. Investigations of diffuse sound fields using systematic changes in surface scattering

    Science.gov (United States)

    Herder, John

    Systematically varying the surface scattering in an enclosure provides insight towards the impact of field diffusion on acoustic phenomena. Two independent studies are presented, each utilizing three distinct cases of field diffusion created through the introduction of boundary irregularities. First, dodecaspherical loudspeakers used in acoustic measurement exhibit non-uniform radiation. Also, the interaction of the source sound with room boundaries impacts the degree of energy interference and decay over time. As such, the amount of variation in sound pressure level and clarity over a grid of receivers is investigated with respect to stand-alone cases as well as the promotion of field diffusion. By sequentially expanding the extent of energy mixing in a volume, it is expected that variations in the acoustic parameters over an area will be reduced. Developing a consistent aural experience over a listening area is an important topic in room acoustics, so exploring the physical impact of field diffusion on sound field variance advances this aim. The second experiment reinforces a method for understanding the time arrival of diffuse sound fields in a volume. By systematically promoting greater diffusion, it is expected that the corresponding diffuse sound field will arrive earlier. The turning point property of experimental double sloped energy decays is investigated against a diffusion equation model, relating the valid range of the numerical model to the time onset of the diffuse sound field. In this way, the time arrival of the diffuse sound field is calculated in terms of the change in mean free time between cases. The effect of overall absorption is also discussed, reinforcing the validity of the outcome.

  19. Field Investigation of a New Recharge Approach for ASR Projects in Near-Surface Aquifers.

    Science.gov (United States)

    Liu, Gaisheng; Knobbe, Steven; Reboulet, Edward C; Whittemore, Donald O; Händel, Falk; Butler, James J

    2016-05-01

    Aquifer storage and recovery (ASR) is the artificial recharge and temporary storage of water in an aquifer when water is abundant, and recovery of all or a portion of that water when it is needed. One key limiting factor that still hinders the effectiveness of ASR is the high costs of constructing, maintaining, and operating the artificial recharge systems. Here we investigate a new recharge method for ASR in near-surface unconsolidated aquifers that uses small-diameter, low-cost wells installed with direct-push (DP) technology. The effectiveness of a DP well for ASR recharge is compared with that of a surface infiltration basin at a field site in north-central Kansas. The performance of the surface basin was poor at the site due to the presence of a shallow continuous clay layer, identified with DP profiling methods, that constrained the downward movement of infiltrated water and significantly reduced the basin recharge capacity. The DP well penetrated through this clay layer and was able to recharge water by gravity alone at a much higher rate. Most importantly, the costs of the DP well, including both the construction and land costs, were only a small fraction of those for the infiltration basin. This low-cost approach could significantly expand the applicability of ASR as a water resources management tool to entities with limited fiscal resources, such as many small municipalities and rural communities. The results of this investigation demonstrate the great potential of DP wells as a new recharge option for ASR projects in near-surface unconsolidated aquifers.

  20. The SERMON project: 48 new field Blazhko stars and an investigation of modulation-period distribution

    Science.gov (United States)

    Skarka, M.; Liška, J.; Auer, R. F.; Prudil, Z.; Juráňová, A.; Sódor, Á.

    2016-08-01

    Aims: We investigated 1234 fundamental mode RR Lyrae stars observed by the All Sky Automated Survey (ASAS) to identify the Blazhko (BL) effect. A sample of 1547 BL stars from the literature was collected to compare the modulation-period distribution with stars newly identified in our sample. Methods: A classical frequency spectra analysis was performed using Period04 software. Data points from each star from the ASAS database were analysed individually to avoid confusion with artificial peaks and aliases. Statistical methods were used in the investigation of the modulation-period distribution. Results: Altogether we identified 87 BL stars (48 new detections), 7 candidate stars, and 22 stars showing long-term period variations. The distribution of modulation periods of newly identified BL stars corresponds well to the distribution of modulation periods of stars located in the Galactic field, Galactic bulge, Large Magellanic Cloud, and globular cluster M5 collected from the literature. As a very important by-product of this comparison, we found that pulsation periods of BL stars follow Gaussian distribution with the mean period of 0.54 ± 0.07 d, while the modulation periods show log-normal distribution with centre at log (Pm [d]) = 1.78 ± 0.30 dex. This means that 99.7% of all known modulated stars have BL periods between 7.6 and 478 days. We discuss the identification of long modulation periods and show, that a significant percentage of stars showing long-term period variations could be classified as BL stars.

  1. Second-order spatial correlation in the far-field: Comparing entangled and classical light sources

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Erfeng, E-mail: efzhang@163.com; Liu, Weitao; Lin, Huizu; Chen, Pingxing

    2016-02-15

    Highlights: • Second-order spatial correlation with entangled and classical light in the far-field is investigated. • The role of photon statistics and detection mode in the second-order spatial correlation are discussed. • The difference of second-order spatial correlation with entangled and classical light sources is deduced. - Abstract: We consider second-order spatial correlation with entangled and classical light in the far-field. The quantum theory of second-order spatial correlation is analyzed, and the role of photon statistics and detection mode in the second-order spatial correlation are discussed. Meanwhile, the difference of second-order spatial correlation with entangled and classical light sources is deduced.

  2. Investigating and improving introductory physics students’ understanding of the electric field and superposition principle

    Science.gov (United States)

    Li, Jing; Singh, Chandralekha

    2017-09-01

    We discuss an investigation of the difficulties that students in a university introductory physics course have with the electric field and superposition principle and how that research was used as a guide in the development and evaluation of a research-validated tutorial on these topics to help students learn these concepts better. The tutorial uses a guided enquiry-based approach to learning and involved an iterative process of development and evaluation. During its development, we obtained feedback both from physics instructors who regularly teach introductory physics in which these concepts are taught and from students for whom the tutorial is intended. The iterative process continued and the feedback was incorporated in the later versions of the tutorial until the researchers were satisfied with the performance of a diverse group of introductory physics students on the post-test after they worked on the tutorial in an individual one-on-one interview situation. Then the final version of the tutorial was administered in several sections of the university physics course after traditional instruction in relevant concepts. We discuss the performance of students in individual interviews and on the pre-test administered before the tutorial (but after traditional lecture-based instruction) and on the post-test administered after the tutorial. We also compare student performance in sections of the class in which students worked on the tutorial with other similar sections of the class in which students only learned via traditional instruction. We find that students performed significantly better in the sections of the class in which the tutorial was used compared to when students learned the material via only lecture-based instruction.

  3. Comparative Investigation of Protective Effects of Metyrosine and Metoprolol Against Ketamine Cardiotoxicity in Rats.

    Science.gov (United States)

    Ahiskalioglu, Ali; Ince, Ilker; Aksoy, Mehmet; Ahiskalioglu, Elif Oral; Comez, Mehmet; Dostbil, Aysenur; Celik, Mine; Alp, Hamit Hakan; Coskun, Resit; Taghizadehghalehjoughi, Ali; Suleyman, Bahadir

    2015-10-01

    This study investigated the effect of metyrosine against ketamine-induced cardiotoxicity in rats and compared the results with the effect of metoprolol. In this study, rats were divided into groups A, B and C. In group A, we investigated the effects of a single dose of metyrosine (150 mg/kg) and metoprolol (20 mg/kg) on single dose ketamine (60 mg/kg)-induced cardiotoxicity. In group B, we investigated the effect of metyrosine and metoprolol, which were given together with ketamine for 30 days. In group C, we investigated the effect of metyrosine and metoprolol given 15 days before ketamine and 30 days together with ketamine on ketamine cardiotoxicity. By the end of this process, we evaluated the effects of the levels of oxidant-antioxidant parameters such as MDA, MPO, 8-OHGua, tGSH, and SOD in addition to CK-MB and TP I on cardiotoxicity in rat heart tissue. The experimental results show that metyrosine prevented ketamine cardiotoxicity in groups A, B and C and metoprolol prevented it in only group C.

  4. Biodegradation of phenol: a comparative study with and without applying magnetic fields.

    Science.gov (United States)

    Jung, J; Sanji, B; Godbole, S; Sofer, S

    1993-01-01

    The objective of this work was to study the effect of magnetic fields on the rate of phenol biodegradation using immobilized activated sludge. A recirculation flow bioreactor employing immobilized bacterial beads was used with phenol as the substrate to study the biodegradation process. This study was conducted by applying separately the north pole and the south pole magnetic fields to the bioreactor. Rate of dissolved oxygen consumption, phenol concentration and extracellular protein concentration were the parameters monitored during the process. It was observed that by applying a magnetic south pole to the process, biodegradation in the form of biological oxidation was enhanced. A 30% increase in biodegradation rate was obtained by applying a magnetic south pole of strength of 0.45 Tesla to the bioreactor with immobilized microbial beads as compared to the control. Magnetic north pole irradiation inhibited this type of biooxidation. This process has potential for biological treatment of organic wastes.

  5. Cytisine derivatives as high affinity nAChR ligands: synthesis and comparative molecular field analysis.

    Science.gov (United States)

    Nicolotti, O; Canu Boido, C; Sparatore, F; Carotti, A

    2002-06-01

    A number of new N-substituted cytisine derivatives were prepared and tested, along with similar compounds already described by us and others, as high affinity neuronal acetylcholine receptor ligands. Structure-affinity relationships were discussed in the light of our recently proposed pharmacophore model for nicotinic receptor agonists. The most significant physicochemical interactions modulating the receptor-ligand binding were detected at the three dimensional (3D) level by means of comparative molecular field analysis (CoMFA). The best predictive PLS model was a single-field steric model showing good statistical figures: n = 17, Q2 = 0.717, s(ev) = 0.566, r2 = 0.942, s = 0.275.

  6. Comparative Visualization of Vector Field Ensembles Based on Longest Common Subsequence

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Richen; Guo, Hanqi; Zhang, Jiang; Yuan, Xiaoru

    2016-04-19

    We propose a longest common subsequence (LCS) based approach to compute the distance among vector field ensembles. By measuring how many common blocks the ensemble pathlines passing through, the LCS distance defines the similarity among vector field ensembles by counting the number of sharing domain data blocks. Compared to the traditional methods (e.g. point-wise Euclidean distance or dynamic time warping distance), the proposed approach is robust to outlier, data missing, and sampling rate of pathline timestep. Taking the advantages of smaller and reusable intermediate output, visualization based on the proposed LCS approach revealing temporal trends in the data at low storage cost, and avoiding tracing pathlines repeatedly. Finally, we evaluate our method on both synthetic data and simulation data, which demonstrate the robustness of the proposed approach.

  7. A Study and Comparative Analysis of Conditional Random Fields for Intrusion Detection

    Directory of Open Access Journals (Sweden)

    Deepa Guleria

    2012-07-01

    Full Text Available Intrusion detection systems are an important component of defensive measures protecting computer systems and networks from abuse. Intrusion detection plays one of the key roles in computer security techniques and is one of the prime areas of research. Due to complex and dynamic nature of computer networks and hacking techniques, detecting malicious activities remains a challenging task for security experts, that is, currently available defense systems suffer from low detection capability and high number of false alarms. An intrusion detection system must reliably detect malicious activities in a network and must perform efficiently to cope with the large amount of network traffic. In this paper we study the Machine Learning and data mining techniques to solve Intrusion Detection problems within computer networks and compare the various approaches with conditional random fields and address these two issues of Accuracy and Efficiency using Conditional Random Fields and Layered Approach.

  8. Speaking Errors of Persian and Azeri Turkish Learners in EFL Classrooms: A Comparative Investigation

    Directory of Open Access Journals (Sweden)

    Saber Atash Nazarloo

    2016-12-01

    Full Text Available The purpose of this study was to investigate and compare the frequency and types of the phonological and syntactic errors made by Persian and Azeri Turkish learners while speaking in EFL classes. To this end, two conversation classes, consisting of EFL students having different native languages (Persian and Azeri Turkish, were selected. During the term, students’ authentic conversations and presentations in English language were recorded. The corpus collected from the two classes was then transcribed and analyzed to determine the frequency of phonological and syntactic errors made by the two groups. The results indicated that Azeri Turkish EFL learners made less phonological errors compared with the Persian learners. However, not a noticeable difference in the frequency of errors in the grammatical structures was observed between the two groups. The results were discussed and the implications were made.

  9. Comparative Investigation on Brazing Behavior, Compressive Strength, and Wear Properties of Multicrystalline CBN Abrasive Grains

    Directory of Open Access Journals (Sweden)

    Wen-Feng Ding

    2014-05-01

    Full Text Available In order to fabricate the abrasive wheels with good grain self-sharpening capacity, two types of multicrystalline CBN grains, that is, polycrystalline CBN (PCBN and binderless CBN (BCBN, were brazed using Cu-Sn-Ti alloy, respectively. Comparative investigation on the brazing interface, compressive strength, and wear properties of the different grains was carried out. Results obtained show that the PCBN grains have more intricate reaction, more complicated resultants, and thicker reaction layer than the BCBN counterparts under the identical brazing conditions. Though the average compressive strength of the PCBN grains is similar to that of BCBN ones, stronger self-sharpening action by virtue of the microfracture behavior takes place with BCBN grains during grinding. As a consequence, compared to the brazed PCBN wheels and the conventional monocrystalline CBN (MCBN ones, longer service life is obtained for the brazed BCBN wheels.

  10. Comparative Investigation of the Efficiency of Absorption of Solar Energy by Carbon Composite Materials

    Science.gov (United States)

    Prikhod‧ko, N. G.; Smagulova, G. T.; Rakhymzhan, N. B.; Kim, S.; Lesbaev, B. T.; Nazhipkyzy, M.; Mansurov, Z. A.

    2017-01-01

    This paper presents the results of research on the efficiency of absorption of solar energy by various carbon materials (soot, carbonized apricot pits and rice husks, and carbon nanotubes in the form of a ″forest″), as well as by composites based on them with inclusions of metal oxide nanoparticles. An analysis of the efficiency of absorption of solar energy by various carbon materials has demonstrated the advantage of the carbon material from carbonized apricot pits. The results of the comparative investigation of the absorptivity of apricot pits with that of the coating of a production prototype of solar collector are presented.

  11. Distinguishing among Declarative, Descriptive and Causal Questions to Guide Field Investigations and Student Assessment

    Science.gov (United States)

    Odom, Arthur Louis; Bell, Clare V.

    2011-01-01

    Teachers as well as students often have difficulty formulating good research questions because not all questions lend themselves to scientific investigation. The following is a guide for high-school and college life-science teachers to help students define question types central to biological field studies. The mayfly nymph was selected as the…

  12. Investigation of the Periodic Magnetic Field Modulation in LHC Superconducting Dipoles

    CERN Document Server

    Pugnat, P; Siemko, A

    2002-01-01

    The windings of high-field accelerator magnets are usually made of Rutherford-type superconducting cables. The magnetic field distribution along the axis of such magnets exhibits a periodic modulation with a wavelength equal to the twist pitch length of the cable used in the winding. This effect, resulting from quasi-persistent currents, was investigated with a Hall probes array inserted inside the aperture of the LHC superconducting dipoles, both in short models and full-scale prototypes. The amplitude and the time dependence of this periodic field oscillation have been studied as a function of the magnet current history. The origin and the impact on the LHC dipoles stability of the non-uniform current redistribution producing such a field modulation are discussed.

  13. Laserspectroscopic investigations of the lithium- D-lines in magnetic fields

    Science.gov (United States)

    Windholz, L.; Jäger, H.; Musso, M.; Zerza, G.

    1990-03-01

    Laser-atomic-beam investigations of the lithium D 1- and D 2-line in magnetic fields were performed using cw-laser excitation and fluorescence detection. For both isotopes6Li and7Li, the hyperfine splittings of the ground level 22 S 1/2 and the upper level of the D 1-line, 22 P 1/2, as well as the isotopic shifts of the D 1- and the D 2-line were determined from the registrations without field. In magnetic fields, Zeeman- and Paschen-Back-effects of the lines were studied. Using the Zeeman pattern of the D 1-line for a calibration of the field strength, values for the hyperfine constants A and B of the 22 P 3/2-level of7Li could be derived from the Zeeman pattern of the D 2-line.

  14. Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Chandan; Raustad, Richard

    2013-07-01

    Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

  15. Action of combined magnetic fields on aqueous solution of glutamic acid: the further development of investigations.

    Science.gov (United States)

    Giuliani, Livio; Grimaldi, Settimio; Lisi, Antonella; D'Emilia, Enrico; Bobkova, Natalia; Zhadin, Mikhail

    2008-01-25

    In the present work the results of the known investigation of the influence of combined static (40 microT) and alternating (amplitude of 40 nT) parallel magnetic fields on the current through the aqueous solution of glutamic acid, were successfully replicated. Fourteen experiments were carried out by the application of the combined magnetic fields to the solution placed into a Plexiglas reaction vessel at application of static voltage to golden electrodes placed into the solution. Six experiments were carried out by the application of the combined magnetic fields to the solution placed in a Plexiglas reaction vessel, without electrodes, within an electric field, generated by means of a capacitor at the voltage of 27 mV. The frequency of the alternating field was scanned within the bounds of 1.0 Hz including the cyclotron frequency corresponding to a glutamic acid ion and to the applied static magnetic field. In this study the prominent peaks with half-width of approximately 0.5 Hz and with different heights (till 80 nA) were registered at the alternating magnetic field frequency equal to the cyclotron frequency (4.2 Hz). The general reproducibility of the investigated effects was 70% among the all solutions studied by us and they arose usually after 40-60 min. after preparation of the solution. In some made-up solutions the appearance of instability in the registered current was noted in 30-45 min after the solution preparation. This instability endured for 20-40 min. At the end of such instability period the effects of combined fields action appeared practically every time. The possible mechanisms of revealed effects were discussed on the basis of modern quantum electrodynamics.

  16. An investigation of methods for free-field comparison calibration of measurement microphones

    DEFF Research Database (Denmark)

    Barrera-Figueroa, Salvador; Moreno Pescador, Guillermo; Jacobsen, Finn

    2010-01-01

    method requires the sound field to have good temporal stability. The simultaneous method requires instead that the sound pressure is the same in the positions where the microphones are placed. In this paper the results of the application of the two methods are compared. A third combined method...

  17. EXPERIMENTAL INVESTIGATION FOR THE EFFECT OF ROTATION ON THREE-DIMENSIONAL FLOW FIELD IN FILM-COOLED TURBINE

    Institute of Scientific and Technical Information of China (English)

    YUAN Feng; ZHU Xiaocheng; DU Zhaohui

    2007-01-01

    An experimental investigation of three-dimensional flow field in a film-cooled turbine model is carried out by using particle image velocimeter (PIV) in a low-speed wind tunnel. The effects of different blowing ratios (M=1.5, 2) on the flow field are studied. The experimental results reveal the classical phenomena of the formation of kidney vortex pair and secondary flow in wake region behind the jet hole. And the changes of the kidney vortex pair and the wake at different locations away from the hole on the suction and pressure sides are also studied. Compared with the flow field in stationary cascade, there are centrifugal force and Coriolis force existing in the flow field of rotating turbine, and these forces bring the radial velocity in the jet flow. The effect of rotation on the flow field of the pressure side is more distinct than that on the suction side from the measured flow fields in Y-Z plane and radial velocity contours. The increase of blowing ratio makes the kidney vortex pair and the secondary flow in the wake region stronger and makes the range of the wake region enlarged.

  18. The field investigation on thermal comfort of tent in early autumn of Tianjin

    Directory of Open Access Journals (Sweden)

    Yang Hao

    2016-01-01

    Full Text Available In a university campus in Tianjin, four tents were set up to investigate the thermal environment and thermal comfort. Both the field investigation and questionnaires were adopted in this experiment. Two hundred people were investigated, and two hundred questionnaires were gotten. The results show that the thermal comfort zone of officers and soldiers is 24°C to 28°C in early fall, it is a wide range. There is a big error between the PMV index and the actual survey results, PMV calculation index is not accurate in tents environment. The results will have a significant effect on improving the thermal comfort of tents..

  19. Beware the black box: investigating the sensitivity of FEA simulations to modelling factors in comparative biomechanics.

    Science.gov (United States)

    Walmsley, Christopher W; McCurry, Matthew R; Clausen, Phillip D; McHenry, Colin R

    2013-01-01

    Finite element analysis (FEA) is a computational technique of growing popularity in the field of comparative biomechanics, and is an easily accessible platform for form-function analyses of biological structures. However, its rapid evolution in recent years from a novel approach to common practice demands some scrutiny in regards to the validity of results and the appropriateness of assumptions inherent in setting up simulations. Both validation and sensitivity analyses remain unexplored in many comparative analyses, and assumptions considered to be 'reasonable' are often assumed to have little influence on the results and their interpretation. HERE WE REPORT AN EXTENSIVE SENSITIVITY ANALYSIS WHERE HIGH RESOLUTION FINITE ELEMENT (FE) MODELS OF MANDIBLES FROM SEVEN SPECIES OF CROCODILE WERE ANALYSED UNDER LOADS TYPICAL FOR COMPARATIVE ANALYSIS: biting, shaking, and twisting. Simulations explored the effect on both the absolute response and the interspecies pattern of results to variations in commonly used input parameters. Our sensitivity analysis focuses on assumptions relating to the selection of material properties (heterogeneous or homogeneous), scaling (standardising volume, surface area, or length), tooth position (front, mid, or back tooth engagement), and linear load case (type of loading for each feeding type). Our findings show that in a comparative context, FE models are far less sensitive to the selection of material property values and scaling to either volume or surface area than they are to those assumptions relating to the functional aspects of the simulation, such as tooth position and linear load case. Results show a complex interaction between simulation assumptions, depending on the combination of assumptions and the overall shape of each specimen. Keeping assumptions consistent between models in an analysis does not ensure that results can be generalised beyond the specific set of assumptions used. Logically, different comparative datasets would

  20. Comparative analysis of field-isolate and monkey-adapted Plasmodium vivax genomes.

    Science.gov (United States)

    Chan, Ernest R; Barnwell, John W; Zimmerman, Peter A; Serre, David

    2015-03-01

    Significant insights into the biology of Plasmodium vivax have been gained from the ability to successfully adapt human infections to non-human primates. P. vivax strains grown in monkeys serve as a renewable source of parasites for in vitro and ex vivo experimental studies and functional assays, or for studying in vivo the relapse characteristics, mosquito species compatibilities, drug susceptibility profiles or immune responses towards potential vaccine candidates. Despite the importance of these studies, little is known as to how adaptation to a different host species may influence the genome of P. vivax. In addition, it is unclear whether these monkey-adapted strains consist of a single clonal population of parasites or if they retain the multiclonal complexity commonly observed in field isolates. Here we compare the genome sequences of seven P. vivax strains adapted to New World monkeys with those of six human clinical isolates collected directly in the field. We show that the adaptation of P. vivax parasites to monkey hosts, and their subsequent propagation, did not result in significant modifications of their genome sequence and that these monkey-adapted strains recapitulate the genomic diversity of field isolates. Our analyses also reveal that these strains are not always genetically homogeneous and should be analyzed cautiously. Overall, our study provides a framework to better leverage this important research material and fully utilize this resource for improving our understanding of P. vivax biology.

  1. A comparative molecular field analysis of cytotoxic beta-carboline analogs

    Institute of Scientific and Technical Information of China (English)

    Xue-rui HOU; Qi CHEN; Ri-hui CAO; Wen-lie PENG; An-long XU

    2004-01-01

    AIM: To derive a model that could be used in drug design. METHODS: Beta-carbolines are reported to have antitumor activities on cultured cancer cell lines. A comparative molecular field analysis (CoMFA) was undertaken to elucidate the correlation of cytotoxities and structural parameters of 16 beta-carboline analogs (1-16). The compound 12 was finally used as a template for the other compounds in the dataset because of its highest biological activity. RESULTS: The CoMFA applied to the final alignment resulted in a q2cv of 0.656 and it showed that the steric fields contributed 43.3 % of the model information while the electrostatic fields represented the other 56.7 %.CONCLUSION: Three designed compounds, which were predicted to have high, moderate and low activities respectively, were synthesized. The IC50 values of these compounds indicated the significance of the analysis in this study. The model derived from the current study could be further used in design for more active compounds.

  2. 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.)

  3. A NUMERICAL INVESTIGATION OF EFFECT OF MAGNETIC FIELD ON HEAT CONVECTION WITH VARIABLE PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Ziyaddin RECEBLİ

    2008-01-01

    Full Text Available In some studies, the effect of magnetic field on heat convection has been investigated given that physical properties are constant regardless of temperature. The effect of magnetic field on heat convection and fluids whose physical properties change by temperature has been investigated in this study as physical properties of fluids change by the effect of temperature. Momentum, continuity and energy equations including electromagnetic force affecting the fluid were used in the solution. Temperatures at axial and radial directions and Nusselt numbers were calculated depending on magnetic field intensity and other physical properties of fluid by solving the equation system written in cylindrical coordinates system by means of one of the numerical methods which is finite difference method. According to results, velocity and temperature of the cooled fluid decreased following an increase in the intensity of magnetic field placed vertically to flow direction. As determined in the previous one, this study also indicated that the increase in Reynolds number increases Nusselt number, and increasing the effect of magnetic field decreases Nusselt number. The theoretical results of the present study are in conformity with the results of our previous one.

  4. Visual field defects of optic neuritis in neuromyelitis optica compared with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Sugasawa Jun

    2010-06-01

    Full Text Available Abstract Background Neuromyelitis optica (NMO is an inflammatory demyelinating disease that predominantly affects the optic nerves and the spinal cord, and is possibly mediated by an immune mechanism distinct from that of multiple sclerosis (MS. Central scotoma is recognized as a characteristic visual field defect pattern of optic neuritis (ON, however, the differing pathogenic mechanisms of NMO and MS may result in different patterns of visual field defects for ON. Methods Medical records of 15 patients with NMO and 20 patients with MS having ON were retrospectively analyzed. A thorough systemic and neurological examination was performed for evaluating ON. The total number of relapses of ON and visual fields was investigated. Visual fields were obtained by Goldmann perimeter with each ON relapse. Results All MS patients experienced central scotoma, with 90% of them showing central scotoma with every ON relapse. However, 53% of NMO patients showed central scotoma with every ON relapse (p = 0.022, and the remaining 47% of patients experienced non-central scotoma (altitudinal, quadrant, three quadrant, hemianopia, and bitemporal hemianopia. Thirteen percent of NMO patients did not experience central scotoma during their disease course. Altitudinal hemianopia was the most frequent non-central scotoma pattern in NMO. Conclusions NMO patients showed higher incidence of non-central scotoma than MS, and altitudinal hemianopia may be characteristic of ON occurring in NMO. As altitudinal hemianopia is highly characteristic of ischemic optic neuropathy, we suggest that an ischemic mechanism mediated by anti-aquaporin-4 antibody may play a role in ON in NMO patients.

  5. Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

    Science.gov (United States)

    Li, Hui; Kayhanian, Masoud; Harvey, John T

    2013-03-30

    Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability.

  6. Determination of satellite valley position in GaN emitter from photoexcited field emission investigations

    Science.gov (United States)

    Semenenko, M.; Yilmazoglu, O.; Hartnagel, H. L.; Pavlidis, D.

    2011-01-01

    Argon plasma etched GaN field-emitter rods with nanometer-scale diameter were fabricated on GaN grown on an n+-GaN substrate. Their electron field emission properties were investigated both without and under illumination by using light sources with various wavelengths. The Fowler-Nordheim current-voltage characteristics of the cathodes show a change in slope for illuminated cathodes. The electron affinity difference ΔE between the different valleys in the conduction band has been ascertained and is in the range from 1.18 up to 1.21 eV.

  7. Simultaneous investigation of ultrafast structural dynamics and transient electric field by sub-picosecond electron pulses

    Energy Technology Data Exchange (ETDEWEB)

    Li, Run-Ze; Zhu, Pengfei; Chen, Long; Chen, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn; Sheng, Zheng-Ming; Zhang, Jie, E-mail: jiec@sjtu.edu.cn, E-mail: jzhang1@sjtu.edu.cn [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Cao, Jianming [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Physics Department and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

    2014-05-14

    The ultrafast structure dynamics and surface transient electric field, which are concurrently induced by laser excited electrons of an aluminum nanofilm, have been investigated simultaneously by the same transmission electron diffraction patterns. These two processes are found to be significantly different and distinguishable by tracing the time dependent changes of electron diffraction and deflection angles, respectively. This study also provides a practical means to evaluate simultaneously the effect of transient electric field during the study of structural dynamics under low pump fluence by transmission ultrafast electron diffraction.

  8. Investigation on stresses of superconductors under pulsed magnetic fields based on multiphysics model

    Science.gov (United States)

    Yang, Xiaobin; Li, Xiuhong; He, Yafeng; Wang, Xiaojun; Xu, Bo

    2017-04-01

    A multiphysics model for the numerical computation of stresses, trapped field and temperature distribution of a infinite long superconducting cylinder is proposed, based on which the stresses, including the thermal stresses and mechanical stresses due to Lorentz force, and trapped fields in the superconductor subjected to pulsed magnetic fields are analyzed. By comparing the results under pulsed magnetic fields with different pulse durations, it is found that the both the mechanical stress due to the electromagnetic force and the thermal stress due to temperature gradient contribute to the total stress level in the superconductor. For pulsed magnetic field with short durations, the thermal stress is the dominant contribution to the total stress, because the heat generated by AC-loss builds up significant temperature gradient in such short durations. However, for a pulsed field with a long duration the gradient of temperature and flux, as well as the maximal tensile stress, are much smaller. And the results of this paper is meaningful for the design and manufacture of superconducting permanent magnets.

  9. An Investigation of Perpendicular Gradients of Parallel Electric Field Associated with Magnetic Reconnection

    Science.gov (United States)

    Sturner, A. P.; Ergun, R.; Newman, D. L.; Lapenta, G.

    2014-12-01

    Many observations of particle heating and acceleration throughout the universe have been associated with magnetic reconnection. Generalized Ohm's Law describes how particles move under ideal and non-ideal conditions; however, it is insufficient for describing how the magnetic field itself changes. Initial studies have shown that a curl of a parallel electric field is necessary for reconnection to occur. These analytic studies have demonstrated that perpendicular gradients in the parallel electric field drive a counter-twisting of the magnetic field on either side of the localized parallel electric field. This results in the slippage of magnetic flux tubes and a break down of the 'frozen-in' condition. In this presentation, we analyze results from self-consistent implicit kinetic particle-in-cell simulations. The strongest gradients of parallel electric fields in the simulations are along the separator and not at the X-point. We will present where in the simulation domain the 'frozen-in' condition breaks down and compare it with the location of these gradients, and discuss the implications.

  10. Investigating membrane nanoporation induced by bipolar pulsed electric fields via second harmonic generation

    Science.gov (United States)

    Moen, E. K.; Ibey, B. L.; Beier, H. T.; Armani, A. M.

    2016-09-01

    Electric pulses have become an effective tool for transporting cargo (DNA, drugs, etc.) across cell membranes. This enhanced transport is believed to occur through temporary pores formed in the plasma membrane. Traditionally, millisecond duration, monopolar (MP) pulses are used for electroporation, but bipolar (BP) pulses have proven equally effective as MP pulses with the added advantage of less cytotoxicity. With the goal of further reducing cytotoxic effects and inducing non-thermal, intra-cellular effects, researchers began investigating reduced pulse durations, pushing into the nanosecond regime. Cells exposed to these MP, nanosecond pulsed electric fields (nsPEFs) have shown increased repairable membrane permeability and selective channel activation. However, attempts to improve this further by moving to the BP pulse regime has proven unsuccessful. In the present work, we use second harmonic generation imaging to explore the structural effects of bipolar nsPEFs on the plasma membrane. By varying the temporal spacing between the pulse phases over several orders of magnitude and comparing the response to a single MP case, we systematically examine the disparity in cellular response. Our circuit-based model predicts that, as the temporal spacing increases several orders of magnitude, nanoporation increases and eventually exceeds the MP case. On the whole, our experimental data agree with this assertion; however, a detailed analysis of the data sets demonstrates that biological processes may play a larger role in the observed response than previously thought, dominating the effect for temporal spacing up to 5 μs. These findings could ultimately lead to understanding the biophysical mechanism underlying all electroporation.

  11. Laboratory experiments investigating magnetic field production via the Weibel instability in interpenetrating plasma flows

    Science.gov (United States)

    Huntington, Channing; Fiuza, Frederico; Ross, James Steven; Zylstra, Alex; Pollock, Brad; Drake, R. Paul; Froula, Dustin; Gregori, Gianluca; Kugland, Nathan; Kuranz, Carolyn; Levy, Matthew; Li, Chikang; Meinecke, Jena; Petrasso, Richard; Remington, Bruce; Ryutov, Dmitri; Sakawa, Youichi; Spitkovsky, Anatoly; Takabe, Hideke; Turnbull, David; Park, Hye-Sook

    2015-08-01

    Astrophysical collisionless shocks are often associated with the presence of strong magnetic fields in a plasma flow. The magnetic fields required for shock formation may either be initially present, for example in supernova remnants or young galaxies, or they may be self-generated in systems such as gamma-ray bursts (GRBs). In the case of GRB outflows, the intense magnetic fields are greater than those seeded by the GRB progenitor or produced by misaligned density and temperature gradients in the plasma flow (the Biermann-battery effect). The Weibel instability is one candidate mechanism for the generation of sufficiently strong fields to create a collisionless shock. Despite their crucial role in astrophysical systems, observation of the magnetic fields produced by Weibel instabilities in experiments has been challenging. Using a proton probe to directly image electromagnetic fields, we present evidence of Weibel-generated magnetic fields that grow in opposing, initially unmagnetized plasma flows from laser-driven laboratory experiments. Three-dimensional particle-in-cell simulations reveal that the instability efficiently extracts energy from the plasma flows, and that the self-generated magnetic energy reaches a few percent of the total energy in the system. This result demonstrates an experimental platform suitable for the investigation of a wide range of astrophysical phenomena, including collisionless shock formation in supernova remnants, large-scale magnetic field amplification, and the radiation signature from gamma-ray bursts.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  12. Thermo-Kinetic Investigation of Comparative Ligand Effect on Cysteine Iron Redox Reaction

    Directory of Open Access Journals (Sweden)

    Masood Ahmad Rizvi

    2015-03-01

    Full Text Available Transition metal ions in their free state bring unwanted biological oxidations generating oxidative stress. The ligand modulated redox potential can be indispensable in prevention of such oxidative stress by blocking the redundant bio-redox reactions. In this study we investigated the comparative ligand effect on the thermo-kinetic aspects of biologically important cysteine iron (III redox reaction using spectrophotometric and potentiometric methods. The results were corroborated with the complexation effect on redox potential of iron(III-iron(II redox couple. The selected ligands were found to increase the rate of cysteine iron (III redox reaction in proportion to their stability of iron (II complex (EDTA < terpy < bipy < phen. A kinetic profile and the catalytic role of copper (II ions by means of redox shuttle mechanism for the cysteine iron (III redox reaction in presence of 1,10-phenanthroline (phen ligand is also reported.

  13. Comparative Investigation for Energy Consumption of Different Chipsets Based on Scheduling for Wireless Sensor Networks

    CERN Document Server

    Monica,; 10.5121/ijcnc.2010.2511

    2010-01-01

    Rapid progress in microelectromechanical system (MEMS) and radio frequency (RF) design has enabled the development of low-power, inexpensive, and network-enabled microsensors. These sensor nodes are capable of capturing various physical information, such as temperature, pressure, motion of an object, etc as well as mapping such physical characteristics of the environment to quantitative measurements. A typical wireless sensor network (WSN) consists of hundreds to thousands of such sensor nodes linked by a wireless medium. In this paper, we present a comparative investigation of energy consumption for few commercially available chipsets such as TR1001, CC1000 and CC1010 based on different scheduling methods for two types of deployment strategies. We conducted our experiment within the OMNeT++ simulator.

  14. Comparative investigation on the removal of cyanide from aqueous solution using two different bioadsorbents

    Directory of Open Access Journals (Sweden)

    Naveen Dwivedi

    2016-09-01

    Full Text Available In the present study, comparative investigation for the bioremoval of cyanide from synthetic aqueous solution by Prunus amygdalus (Almond shell (PAS and Tectona grandis (Sagwan leaves (TGL powder have been performed as a function of solution pH, bioadsorbent dose, contact time and initial cyanide concentration. The cyanide uptake by PAS and TGL powder has been quantitatively estimated using sorption isotherms. The equilibrium data are best fitted to Freundlich and Langmuir isotherm model for PAS and TGL powder respectively. The monolayer capacity of PAS and TGL powder for cyanide adsorption as calculated by Langmuir isotherm are 32.05 mg/g and 18.45 mg/g respectively. The kinetic data are found to follow closely the pseudo-second order kinetic model for both the bioadsorbents. The present study shows that such low cost materials could be used as efficient bioadsorbents for the removal of cyanide from aqueous solutions.

  15. An experiment-based comparative investigation of correlations for microtube gas flow

    Indian Academy of Sciences (India)

    K Tang; J L Huang; T Jin; M X Wu

    2015-04-01

    An experimental system was built to measure the gas (nitrogen and helium) flow characteristics in circular microchannels with diameters of 50, 20 and 5 m. The Reynolds number of the flow was controlled in the large range of 15 to 2550. The highest Mach number could reach a magnitude of 0.625 and the highest Knudsen number was over 0.021. Four available empirical correlations were comparatively studied, in terms of the influence from compressibility and rarefaction. The accuracy of each correlation was investigated, and qualitative explanations were given according to the essence of fluid dynamics. The compressibility is found to be the dominant parameter in the experiments carried out. The results obtained by gas flow in holey optical fibres are helpful for the design of micro-scale pulse tube cryocoolers.

  16. Neutron investigations of magnetic properties of crystal substances with use of a pulsed magnetic field

    CERN Document Server

    Nitts, V V

    2001-01-01

    Bases for neutron researches of magnetic properties of crystal substances with use of a pulsed magnetic field and analysis of possible application of various neutron sources in this area are submitted. The review of the most interesting physical results is presented. Main investigations on pulsed reactors of JINR are researches on kinetics of the first order reorientational phase transitions induced in single crystals, and also measurements of antiferromagnetic ordering induced by an external magnetic field. Magnetic phase transitions, induced by a field up to 160 kOe in several magnetic ordering substances, were studied in KEK (Japan). Experiment on observation of spin-flop transition in MnF sub 2 was carried out on TRIGA-reactor in a mode of single flashes of power

  17. Comparative investigation of pure and mixed rare gas atoms on coronene molecules.

    Science.gov (United States)

    Rodríguez-Cantano, Rocío; Bartolomei, Massimiliano; Hernández, Marta I; Campos-Martínez, José; González-Lezana, Tomás; Villarreal, Pablo; Pérez de Tudela, Ricardo; Pirani, Fernando; Hernández-Rojas, Javier; Bretón, José

    2017-01-21

    Clusters formed by the combination of rare gas (RG) atoms of He, Ne, Ar, and Kr on coronene have been investigated by means of a basin-hopping algorithm and path integral Monte Carlo calculations at T = 2 K. Energies and geometries have been obtained and the role played by the specific RG-RG and RG-coronene interactions on the final results is analysed in detail. Signatures of diffuse behavior of the He atoms on the surface of the coronene are in contrast with the localization of the heavier species, Ar and Kr. The observed coexistence of various geometries for Ne suggests the motion of the RG atoms on the multi-well potential energy surface landscape offered by the coronene. Therefore, the investigation of different clusters enables a comparative analysis of localized versus non-localized features. Mixed Ar-He-coronene clusters have also been considered and the competition of the RG atoms to occupy the docking sites on the molecule is discussed. All the obtained information is crucial to assess the behavior of coronene, a prototypical polycyclic aromatic hydrocarbon clustering with RG atoms at a temperature close to that of interstellar medium, which arises from the critical balance of the interactions involved.

  18. Initial Results from the Vector Electric Field Investigation on the C/NOFS Satellite

    Science.gov (United States)

    Pfaff, R.; Rowland, D.; Acuna, M.; Le, G.; Farrell, W.; Holzworth, R.; Wilson, G.; Burke, W.; Freudenreich, H.; Bromund, K.; hide

    2009-01-01

    Initial results are presented from the Vector Electric Field Investigation (VEFI) on the Air Force Communication/Navigation Outage Forecasting System (C/NOFS) satellite, a mission designed to understand, model, and forecast the presence of equatorial ionospheric irregularities. The VEFI instrument includes a vector DC electric field detector, a fixed-bias Langmuir probe operating in the ion saturation regime, a flux gate magnetometer, an optical lightning detector, and associated electronics including a burst memory. The DC electric field detector has revealed zonal and meridional electric fields that undergo a diurnal variation, typically displaying eastward and outward-directed fields during the day and westward and downward-directed fields at night. In general, the measured DC electric field amplitudes are in the 0.5-2 mV/m range, corresponding to I3 x B drifts of the order of 30-150 m/s. What is surprising is the high degree of large-scale (10's to 100's of km) structure in the DC electric field, particularly at night, regardless of whether well-defined spread-F plasma density depletions are present. The spread-F density depletions and corresponding electric fields that have been detected thus far have displayed a preponderance to appear between midnight and dawn. Associated with the narrow plasma depletions that are detected are broad spectra of electric field and plasma density irregularities for which a full vector set of measurements is available for detailed study. On some occasions, localized regions of low frequency (field broadband irregularities have been detected, suggestive of filamentary currents, although there is no one-to-one correspondence of these waves with the observed plasma density depletions, at least within the data examined thus far. Finally, the data set includes a wide range of ELF/VLF/HF waves corresponding to a variety of plasma waves, in particular banded ELF hiss, whistlers, and lower hybrid wave turbulence triggered by lightning

  19. Targeted Protein Degradation by Salmonella under Phagosome-Mimicking Culture Conditions Investigated Using Comparative Peptidomics

    Energy Technology Data Exchange (ETDEWEB)

    Manes, Nathan P.; Gustin, Jean K.; Rue, Joanne; Mottaz, Heather M.; Purvine, Samuel O.; Norbeck, Angela D.; Monroe, Matthew E.; Zimmer, Jennifer S.; Metz, Thomas O.; Adkins, Joshua N.; Smith, Richard D.; Heffron, Fred

    2007-04-01

    The pathogen Salmonella enterica is known to cause both food poisoning and typhoid fever. Due to the emergence of antibiotic-resistant isolates and the threat of bioterrorism (e.g., contamination of the food supply), there is a growing need to study this bacterium. In this investigation, comparative peptidomics was used to study Salmonella enterica serovar Typhimurium cultured in either a rich medium or in an acidic, low magnesium, and minimal nutrient medium designed to roughly mimic the macrophage phagosomal compartment (within which Salmonella are known to survive). Native peptides from cleared cell lysates were enriched by using isopropanol extraction and analyzed by using both LC-MS/MS and LC-FTICR-MS. We identified 5,163 distinct peptides originating from 682 proteins and the data clearly indicated that compared to cells cultured in the rich medium, Salmonella cultured in the phagosome-mimicking medium had dramatically higher abundances of a wide variety of protein degradation products, especially from ribosomal proteins. Salmonella from the same cultures were also analyzed by using bottom-up proteomics, and when the peptidomic and proteomic data were analyzed together, two clusters of proteins targeted for proteolysis were tentatively identified. Possible roles of targeted proteolysis by phagocytosed Salmonella are discussed.

  20. Investigation of Multiscale Non-equilibrium Flow Dynamics Under External Force Field

    CERN Document Server

    Xiao, Tianbai

    2016-01-01

    The multiple scale non-equilibrium gaseous flow behavior under external force field is investigated. Both theoretical analysis based on the kinetic model equation and numerical study are presented to demonstrate the dynamic effect of external force on the flow evolution, especially on the non-equilibrium heat flux. The current numerical experiment is based on the well-balanced unified gas-kinetic scheme (UGKS), which presents accurate solutions in the whole flow regime from the continuum Navier-Stokes solution to the transition and free molecular ones. The heat conduction in the non-equilibrium regime due to the external forcing term is quantitatively investigated. In the lid-driven cavity flow study, due to the external force field the density distribution inside cavity gets stratified and a multiscale non-equilibrium flow transport appears in a single gas dynamic system. With the increment of external forcing term, the flow topological structure changes dramatically, and the temperature gradient, shearing s...

  1. Biochemical (T2, T2* and magnetisation transfer ratio) MRI of knee cartilage: feasibility at ultra-high field (7T) compared with high field (3T) strength

    Energy Technology Data Exchange (ETDEWEB)

    Welsch, Goetz H. [Medical University of Vienna, MR Center, Department of Radiology, Vienna (Austria); University of Erlangen, Department of Trauma Surgery, Erlangen (Germany); Apprich, Sebastian; Zbyn, Stefan; Trattnig, Siegfried [Medical University of Vienna, MR Center, Department of Radiology, Vienna (Austria); Mamisch, Tallal C. [Medical University of Vienna, MR Center, Department of Radiology, Vienna (Austria); University of Berne, Department of Orthopedic Surgery, Berne (Switzerland); Mlynarik, Vladimir [Ecole Polytechnique Federale de Lausanne, Laboratory of Functional and Metabolic imaging, Lausanne (Switzerland); Scheffler, Klaus; Bieri, Oliver [University Hospital Basel, Division of Radiological Physics, Institute of Radiology, Basel (Switzerland)

    2011-06-15

    This study compares the performance and the reproducibility of quantitative T2, T2* and the magnetisation transfer ratio (MTR) of articular cartilage at 7T and 3T. Axial MRI of the patella was performed in 17 knees of healthy volunteers (25.8 {+-} 5.7 years) at 3T and 7T using a comparable surface coil and whole-body MR systems from the same vendor, side-by-side. Thirteen knee joints were assessed once, and four knee joints were measured three times to assess reproducibility. T2 relaxation was prepared by a multi-echo, spin-echo sequence and T2* relaxation by a multi-echo, gradient-echo sequence. MTR was based on a magnetisation transfer-sensitized, steady-state free precession approach. Statistical analysis-of-variance and coefficient-of-variation (CV) were prepared. For T2 and T2*, global values were significantly lower at 7T compared with 3T; the zonal evaluation revealed significantly less pronounced stratification at 7T (p<0.05). MTR provided higher values at 7T (p<0.05). CV, indicating reproducibility, showed slightly lower values at 7T, but only for T2 and T2*. Although lower T2 and T2* relaxation times were expected at 7T, the differences in stratification between the field strengths were reported for the first time. The assessment of MT is feasible at 7T, but requires further investigation. (orig.)

  2. Biochemical (T2, T2* and magnetisation transfer ratio) MRI of knee cartilage: feasibility at ultra-high field (7T) compared with high field (3T) strength.

    Science.gov (United States)

    Welsch, Goetz H; Apprich, Sebastian; Zbyn, Stefan; Mamisch, Tallal C; Mlynarik, Vladimir; Scheffler, Klaus; Bieri, Oliver; Trattnig, Siegfried

    2011-06-01

    This study compares the performance and the reproducibility of quantitative T2, T2* and the magnetisation transfer ratio (MTR) of articular cartilage at 7T and 3T. Axial MRI of the patella was performed in 17 knees of healthy volunteers (25.8 ± 5.7 years) at 3T and 7T using a comparable surface coil and whole-body MR systems from the same vendor, side-by-side. Thirteen knee joints were assessed once, and four knee joints were measured three times to assess reproducibility. T2 relaxation was prepared by a multi-echo, spin-echo sequence and T2* relaxation by a multi-echo, gradient-echo sequence. MTR was based on a magnetisation transfer-sensitized, steady-state free precession approach. Statistical analysis-of-variance and coefficient-of-variation (CV) were prepared. For T2 and T2*, global values were significantly lower at 7T compared with 3T; the zonal evaluation revealed significantly less pronounced stratification at 7T (p < 0.05). MTR provided higher values at 7T (p < 0.05). CV, indicating reproducibility, showed slightly lower values at 7T, but only for T2 and T2*. Although lower T2 and T2* relaxation times were expected at 7T, the differences in stratification between the field strengths were reported for the first time. The assessment of MT is feasible at 7T, but requires further investigation.

  3. Investigation of possible horizontal gene transfer from transgenic rice to soil microorganisms in paddy rice field.

    Science.gov (United States)

    Kim, Sung Eun; Moon, Jae Sun; Kim, Jung Kyu; Choi, Won Sik; Lee, Sang Han; Kim, Sung Uk

    2010-01-01

    In order to monitor the possibility of horizontal gene transfer between transgenic rice and microorganisms in paddy rice field, the gene flow from bifunctional fusion (TPSP) rice containing trehalose-6-phosphate synthase and phosphatase to microorganisms in soils was investigated. The soil samples collected every month from the paddy rice field during June, 2004 to March, 2006 were investigated by multiplex PCR, Southern hybridization, and amplified fragment length polymorphism (AFLP). The TPSP gene from soil genomics DNAs was not detected by PCR. Soil genomic DNAs were not shown its homologies on the Southern blotting data, indicating that gene-transfer did not occur during the last two years in paddy rice field. In addition, the AFLP band patterns produced by both soil genomic DNAs extracted from transgenic and non-transgenic rice field appeared similar to each other when analyzed by NTSYSpc program. Thus, these data suggest that transgenic rice does not give a significant impact on the communities of soil microorganisms although long-term observation may be needed.

  4. Investigation of Electromagnetic Field Threat to Fuel Tank Wiring of a Transport Aircraft

    Science.gov (United States)

    Ely, Jay J.; Nguyen, Truong X.; Dudley, Kenneth L.; Scearce, Stephen A.; Beck, Fred B.; Deshpande, Manohar D.; Cockrell, C. R.

    2000-01-01

    National Transportation Safety Board investigators have questioned whether an electrical discharge in the Fuel Quantity Indication System (FQIS) may have initiated the TWA-800 center wing tank explosion. Because the FQIS was designed to be incapable of producing such a discharge on its own, attention has been directed to mechanisms of outside electromagnetic influence. To support the investigation, the NASA Langley Research Center was tasked to study the potential for radiated electromagnetic fields from external radio frequency (RF) transmitters and passenger carried portable electronic devices (PEDs) to excite the FQIS enough to cause arcing, sparking or excessive heating within the fuel tank.

  5. Investigation of ginkgo biloba leave extracts as corrosion and Oil field microorganism inhibitors.

    Science.gov (United States)

    Chen, Gang; Zhang, Min; Zhao, Jingrui; Zhou, Rui; Meng, Zuchao; Zhang, Jie

    2013-05-07

    Ginkgo biloba (Ginkgoaceae), originating from China, now distributes all over the world. Wide application of Ginkgo biloba extracts is determined by the main active substances, flavonoids and terpenoids, which indicates its extracts suitable to be used as an effective corrosion inhibitor. The extracts of Ginkgo biloba leave have been investigated on the corrosion inhibition of Q235A steel with weight loss and potentiodynamic polarisation techniques. The inhibition efficiency of the extracts varies with extract concentration. The extracts inhibit corrosion mainly by adsorption mechanism. Potentiodynamic polarisation studies show that extracts are mixed type inhibitors. The antibacterial activity of the extracts against oil field microorganism (SRB, IB and TGB) was also investigated.

  6. Near-field investigation of a plasmonic-photonic hybrid nanolaser

    CERN Document Server

    Zhang, Taiping; Callard, Ségolène; jamois, Cecile; Letartre, Xavier; Chevalier, Celine; Rojo-Romeo, Pedro; Devif, Brice; Viktorovitch, Pierre

    2014-01-01

    We report an approach of realization and characterization of a novel plasmonic-photonic hybrid nanodevice. The device comprises a plasmonic nano-antenna (NA) and a defect mode based PC cavity, and were fabricated based on a multi-step electron-beam lithography. The laser emission of the devices was demonstrated and the coupling conditions between the NA and PC cavity were investigated in near-field level.

  7. Experimental investigation on the near flow field of dual stream nozzles

    Science.gov (United States)

    Sudhakar, S.; Karthikeyan, N.; Ashwin Kumar, S.

    2017-04-01

    An experimental investigation was carried out to investigate the effect of beveling of primary nozzle exit in the near field of a dual stream nozzle flow. Two exit geometry configurations of primary stream nozzle viz., (a) circular (b) bevel along with one exit geometry of the secondary stream-circular, were studied. Experiments were carried out at both subsonic and supersonic primary nozzle operating conditions Mp=0.96 and 1.2. The secondary nozzle exit Mach number was maintained at 0.65 and 0.85 respectively to maintain the velocity ratio of 0.7 between the primary and secondary jet. The by-pass ratio for this investigation is maintained at 2.0. Flow visualization using retro-reflective shadowgraph technique was used for the qualitative visualization of the near flow field at the Mach number of 1.2. The mean and turbulent quantities in near flow field were obtained using particle image Velocimetry (2D-PIV). The flow visualization and PIV investigations show significant change in mean and turbulent quantities brought about in the near field due to the beveling of the primary nozzle. PIV results show increase in the potential core length and reduction in turbulence levels in the potential core by the secondary flow regardless of the jet exit geometry. A differential trend is seen in the shear layer growth and the turbulence characteristics between the shorter and longer lips sides of the beveled nozzle. In the dual stream configurations, bevel nozzle shows lower Reynolds stress values than the circular one except in the shorter lip side at the larger downstream locations.

  8. Effect of synthesis parameters on morphology of polyaniline (PANI) and field emission investigation of PANI nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Bankar, Prashant K.; More, Mahendra A., E-mail: mam@physics.unipune.ac.in [Center for Advanced Studies in Materials Science and Condensed Matter Physics, Department of Physics, University of Pune, Pune-411007 (India); Patil, Sandip S. [Department of Physics, Modern College of Arts, Science and Commerce, Shivajinagar, Pune-411005. India (India)

    2015-06-24

    Polyaniline (PANI) nanostructures have been synthesized by simple chemical oxidation route at different monomer concentration along with variation in synthesis temperature. The effect of variation of synthesis parameters has been revealed using different characterization techniques. The structural and morphological characterization of the synthesized PANI nanostructures was carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), whereas Fourier Transform Infrared spectroscopy (FTIR) has been used to reveal the chemical properties. With the variation in the synthesis temperature and monomer concentration, various morphologies characterized by formation of PANI nanoparticles, nanofibres, nanotubes and nanospheres, are revealed from the SEM analysis. The FTIR analysis reveals the formation of conducting state of PANI under prevailing experimental conditions. The field emission investigation of the conducting PANI nanotubes was performed in all metal UHV system at base pressure of 1x10{sup −8} mbar. The turn on field required to draw emission of 1 nA current was observed to be ∼ 2.2 V/μm and threshold field (corresponding to emission current density of 1 µA/cm2) was found to be 3.2 V/μm. The emission current was observed to be stable for more than three hours at a preset value 1 µA. The simple synthesis route and good field emission characteristics indicate potential of PANI nanofibres as a promising emitter for field emission based micro/nano devices.

  9. Quantitative investigation of cellular growth in directional solidification by phase-field simulation.

    Science.gov (United States)

    Wang, Zhijun; Wang, Jincheng; Li, Junjie; Yang, Gencang; Zhou, Yaohe

    2011-10-01

    Using a quantitative phase-field model, a systematic investigation of cellular growth in directional solidification is carried out with emphasis on the selection of cellular tip undercooling, tip radius, and cellular spacing. Previous analytical models of cellular growth are evaluated according to the phase-field simulation results. The results show that cellular tip undercooling and tip radius not only depend on the pulling velocity and thermal gradient, but also depend on the cellular interaction related to the cellular spacing. The cellular interaction results in a finite stable range of cellular spacing. The lower limit is determined by the submerging mechanism while the upper limit comes from the tip splitting instability corresponding to the absence of the cellular growth solution, both of which can be obtained from phase-field simulation. Further discussions on the phase-field results also present an analytical method to predict the lower limit. Phase-field simulations on cell elimination between cells with equal spacing validate the finite range of cellular spacing and give deep insight into the cellular doublon and oscillatory instability between cell elimination and tip splitting.

  10. Investigation of air-assisted sprays submitted to high frequency transverse acoustic fields: Droplet clustering

    Science.gov (United States)

    Ficuciello, A.; Blaisot, J. B.; Richard, C.; Baillot, F.

    2017-06-01

    An experimental investigation of the effects of a high amplitude transverse acoustic field on coaxial jets is presented in this paper. Water and air are used as working fluids at ambient pressure. The coaxial injectors are placed on the top of a semi-open resonant cavity where the acoustic pressure fluctuations of the standing wave can reach a maximum peak-to-peak amplitude of 12 kPa at the forcing frequency of 1 kHz. Several test conditions are considered in order to quantify the influence of injection conditions, acoustic field amplitude, and injector position with respect to the standing wave acoustic field. A high speed back-light visualization technique is used to characterize the jet response. Image processing is used to obtain valuable information about the jet behavior. It is shown that the acoustic field drastically affects the atomization process for all atomization regimes. The position of the injector in the acoustic field determines the jet response, and a droplet-clustering phenomenon is highlighted in multi-point injection conditions and quantified by determining discrete droplet location distributions. A theoretical model based on nonlinear acoustics related to the spatial distribution of the radiation pressure exerted on an object explains the behavior observed.

  11. Results of investigations at the Zunil geothermal field, Guatemala: Well logging and brine geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Adams, A.; Dennis, B.; Van Eeckhout, E.; Goff, F.; Lawton, R.; Trujillo, P.E.; Counce, D.; Archuleta, J. (Los Alamos National Lab., NM (USA)); Medina, V. (Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico)

    1991-07-01

    The well logging team from Los Alamos and its counterpart from Central America were tasked to investigate the condition of four producing geothermal wells in the Zunil Geothermal Field. The information obtained would be used to help evaluate the Zunil geothermal reservoir in terms of possible additional drilling and future power plant design. The field activities focused on downhole measurements in four production wells (ZCQ-3, ZCQ-4, ZCQ-5, and ZCQ-6). The teams took measurements of the wells in both static (shut-in) and flowing conditions, using the high-temperature well logging tools developed at Los Alamos National Laboratory. Two well logging missions were conducted in the Zunil field. In October 1988 measurements were made in well ZCQ-3, ZCQ-5, and ZCQ-6. In December 1989 the second field operation logged ZCQ-4 and repeated logs in ZCQ-3. Both field operations included not only well logging but the collecting of numerous fluid samples from both thermal and nonthermal waters. 18 refs., 22 figs., 7 tabs.

  12. Comparative Metagenomics of Anode-Associated Microbiomes Developed in Rice Paddy-Field Microbial Fuel Cells

    Science.gov (United States)

    Kouzuma, Atsushi; Kasai, Takuya; Nakagawa, Gen; Yamamuro, Ayaka; Abe, Takashi; Watanabe, Kazuya

    2013-01-01

    In sediment-type microbial fuel cells (sMFCs) operating in rice paddy fields, rice-root exudates are converted to electricity by anode-associated rhizosphere microbes. Previous studies have shown that members of the family Geobacteraceae are enriched on the anodes of rhizosphere sMFCs. To deepen our understanding of rhizosphere microbes involved in electricity generation in sMFCs, here, we conducted comparative analyses of anode-associated microbiomes in three MFC systems: a rice paddy-field sMFC, and acetate- and glucose-fed MFCs in which pieces of graphite felt that had functioned as anodes in rice paddy-field sMFC were used as rhizosphere microbe-bearing anodes. After electric outputs became stable, microbiomes associated with the anodes of these MFC systems were analyzed by pyrotag sequencing of 16S rRNA gene amplicons and Illumina shotgun metagenomics. Pyrotag sequencing showed that Geobacteraceae bacteria were associated with the anodes of all three systems, but the dominant Geobacter species in each MFC were different. Specifically, species closely related to G. metallireducens comprised 90% of the anode Geobacteraceae in the acetate-fed MFC, but were only relatively minor components of the rhizosphere sMFC and glucose-fed MFC, whereas species closely related to G. psychrophilus were abundantly detected. This trend was confirmed by the phylogenetic assignments of predicted genes in shotgun metagenome sequences of the anode microbiomes. Our findings suggest that G. psychrophilus and its related species preferentially grow on the anodes of rhizosphere sMFCs and generate electricity through syntrophic interactions with organisms that excrete electron donors. PMID:24223712

  13. Comparative metagenomics of anode-associated microbiomes developed in rice paddy-field microbial fuel cells.

    Science.gov (United States)

    Kouzuma, Atsushi; Kasai, Takuya; Nakagawa, Gen; Yamamuro, Ayaka; Abe, Takashi; Watanabe, Kazuya

    2013-01-01

    In sediment-type microbial fuel cells (sMFCs) operating in rice paddy fields, rice-root exudates are converted to electricity by anode-associated rhizosphere microbes. Previous studies have shown that members of the family Geobacteraceae are enriched on the anodes of rhizosphere sMFCs. To deepen our understanding of rhizosphere microbes involved in electricity generation in sMFCs, here, we conducted comparative analyses of anode-associated microbiomes in three MFC systems: a rice paddy-field sMFC, and acetate- and glucose-fed MFCs in which pieces of graphite felt that had functioned as anodes in rice paddy-field sMFC were used as rhizosphere microbe-bearing anodes. After electric outputs became stable, microbiomes associated with the anodes of these MFC systems were analyzed by pyrotag sequencing of 16S rRNA gene amplicons and Illumina shotgun metagenomics. Pyrotag sequencing showed that Geobacteraceae bacteria were associated with the anodes of all three systems, but the dominant Geobacter species in each MFC were different. Specifically, species closely related to G. metallireducens comprised 90% of the anode Geobacteraceae in the acetate-fed MFC, but were only relatively minor components of the rhizosphere sMFC and glucose-fed MFC, whereas species closely related to G. psychrophilus were abundantly detected. This trend was confirmed by the phylogenetic assignments of predicted genes in shotgun metagenome sequences of the anode microbiomes. Our findings suggest that G. psychrophilus and its related species preferentially grow on the anodes of rhizosphere sMFCs and generate electricity through syntrophic interactions with organisms that excrete electron donors.

  14. Comparative metagenomics of anode-associated microbiomes developed in rice paddy-field microbial fuel cells.

    Directory of Open Access Journals (Sweden)

    Atsushi Kouzuma

    Full Text Available In sediment-type microbial fuel cells (sMFCs operating in rice paddy fields, rice-root exudates are converted to electricity by anode-associated rhizosphere microbes. Previous studies have shown that members of the family Geobacteraceae are enriched on the anodes of rhizosphere sMFCs. To deepen our understanding of rhizosphere microbes involved in electricity generation in sMFCs, here, we conducted comparative analyses of anode-associated microbiomes in three MFC systems: a rice paddy-field sMFC, and acetate- and glucose-fed MFCs in which pieces of graphite felt that had functioned as anodes in rice paddy-field sMFC were used as rhizosphere microbe-bearing anodes. After electric outputs became stable, microbiomes associated with the anodes of these MFC systems were analyzed by pyrotag sequencing of 16S rRNA gene amplicons and Illumina shotgun metagenomics. Pyrotag sequencing showed that Geobacteraceae bacteria were associated with the anodes of all three systems, but the dominant Geobacter species in each MFC were different. Specifically, species closely related to G. metallireducens comprised 90% of the anode Geobacteraceae in the acetate-fed MFC, but were only relatively minor components of the rhizosphere sMFC and glucose-fed MFC, whereas species closely related to G. psychrophilus were abundantly detected. This trend was confirmed by the phylogenetic assignments of predicted genes in shotgun metagenome sequences of the anode microbiomes. Our findings suggest that G. psychrophilus and its related species preferentially grow on the anodes of rhizosphere sMFCs and generate electricity through syntrophic interactions with organisms that excrete electron donors.

  15. Investigation of the response of a ferrofluid in a surface crack under an applied magnetic field

    OpenAIRE

    Musterni Girbau, Gerard

    2014-01-01

    Non-destructive testing (NDT) is of paramount importance in both the aerospace and general markets. Nowadays, several NDT techniques are available and widely recognised for inspection services. However, wide research is being done in the NDT field to achieve better, cheaper and more efficient techniques. In this research, an assessment of an innovative NDT tehcnique termed Magnetic Early Defect Detection (MEDD) is made using a commercial software package. The results are compared with experim...

  16. A comparative study of divergence cleaning methods of magnetic field in the solar coronal numerical simulation

    Directory of Open Access Journals (Sweden)

    Xueshang eFeng

    2016-03-01

    Full Text Available This paper presents a comparative study of divergence cleaning methods of magnetic field in the solar coronal three-dimensional numerical simulation. For such purpose, the diffusive method, projection method, generalized Lagrange multiplier method and constrained-transport method are used. All these methods are combined with a finite-volume scheme based on a six-component grid system in spherical coordinates. In order to see the performance between the four divergence cleaning methods, solar coronal numerical simulation for Carrington rotation 2056 has been studied. Numerical results show that the average relative divergence error is around $10^{-4.5}$ for the constrained-transport method, while about $10^{-3.1}- 10^{-3.6}$ for the other three methods. Although there exist some differences in the average relative divergence errors for the four employed methods, our tests show they can all produce basic structured solar wind.

  17. Comparative Studies on Preparation of Large Plant DNA Fragments by Pulse Field Gel Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Yang Jiliang(杨继良); Wang Qinghua(王庆华); Deng Daiyong; Yang Dianer; Jin Demin; Weng Manli; Zhang Juren; Wang Bin

    2004-01-01

    The preparation of large plant DNA fragments is extremely important to the construction of large insert DNA libraries (YAC, BAC, PAC and TAC). Although several techniques have been developed in each step of large plant DNA fragments preparation, the whole processing remains complicated and difficult. Based on authors research experience and the recent worldwide development in this field, the following aspects are discussed in this paper: techniques of plant high molecular weight (HMW) DNA purification by pre-electrophoresis, the optimal conditions for the partial digestion of the HMW DNA by HindIII, the isolation effects of of large plant DNA fragments (100~400 kb) with different parameters of pulse field gel electrophoresis (PFGE), and the recovery of large DNA fragments. Through comparative studies, the advantages and disadvantages of each technique are discussed and some recommendations are proposed for preparing high quality large plant DNA fragments. The suggested techniques have been used in preparing the large DNA fragments of maize, rice, moss, laver, sea tangle and peach,and similar results are obtained among all the materials. This paper only reports the results using maize as material.

  18. Numerical and experimental investigation of a beveled trailing-edge flow field and noise emission

    Science.gov (United States)

    van der Velden, W. C. P.; Pröbsting, S.; van Zuijlen, A. H.; de Jong, A. T.; Guan, Y.; Morris, S. C.

    2016-12-01

    Efficient tools and methodology for the prediction of trailing-edge noise experience substantial interest within the wind turbine industry. In recent years, the Lattice Boltzmann Method has received increased attention for providing such an efficient alternative for the numerical solution of complex flow problems. Based on the fully explicit, transient, compressible solution of the Lattice Boltzmann Equation in combination with a Ffowcs-Williams and Hawking aeroacoustic analogy, an estimation of the acoustic radiation in the far field is obtained. To validate this methodology for the prediction of trailing-edge noise, the flow around a flat plate with an asymmetric 25° beveled trailing edge and obtuse corner in a low Mach number flow is analyzed. Flow field dynamics are compared to data obtained experimentally from Particle Image Velocimetry and Hot Wire Anemometry, and compare favorably in terms of mean velocity field and turbulent fluctuations. Moreover, the characteristics of the unsteady surface pressure, which are closely related to the acoustic emission, show good agreement between simulation and experiment. Finally, the prediction of the radiated sound is compared to the results obtained from acoustic phased array measurements in combination with a beamforming methodology. Vortex shedding results in a strong narrowband component centered at a constant Strouhal number in the acoustic spectrum. At higher frequency, a good agreement between simulation and experiment for the broadband noise component is obtained and a typical cardioid-like directivity is recovered.

  19. Less gastrointestinal toxicity after adjuvant radiotherapy on a small pelvic field compared to a standard pelvic field in patients with endometrial carcinoma

    NARCIS (Netherlands)

    de Jong, Renske A.; Pras, Elisabeth; Boezen, H. Marike; van der Zee, Ate G. J.; Mourits, Marian J. E.; Arts, Henriette J. G.; Aalders, Jan G.; Slot, Annerie; Timmer, Paul R.; Hollema, Harry; Nijman, Hans W.

    2012-01-01

    Objective: Radiotherapy is associated with short-term and long-term morbidity. This study compared toxicity rates among patients with endometrial carcinoma (EC) treated with adjuvant external beam radiation therapy (EBRT) on a small pelvic field (SmPF) in comparison with a standard pelvic field (StP

  20. Integrating Field Measurements and Numerical Modeling to Investigate Gully Network Evolution

    Science.gov (United States)

    Rengers, F. K.; Tucker, G. E.

    2011-12-01

    With the advent of numerical modeling the exploration of landscape evolution has advanced from simple thought experiments to investigation of increasingly complex landforming processes. A common criticism of landscape evolution modeling, however, is the lack of model validation with actual field data. Here we present research that continues the advancement of landscape evolution theory by combining detailed field observations with numerical modeling. The focus of our investigation is gully networks on soft-rock strata, where rates of morphologic change are fast enough to measure on annual to decadal time scales. Our research focuses on a highly transient landscape on the high plains of eastern Colorado (40 miles east of Denver, CO) where convective thunderstorms drive ephemeral stream flow, resulting in incised gullies with vertical knickpoints. The site has yielded a comprehensive dataset of hydrology, topography, and geomorphic change. We are continuously monitoring several environmental parameters (including rainfall, overland flow, stream discharge, and soil moisture), and have explored the physical properties of the soil on the site through grain size analysis and infiltration measurements. In addition, time-lapse photography and repeat terrestrial lidar scanning make it possible to track knickpoint dynamics through time. The resulting dataset provides a case study for testing the ability of landscape evolution models to reproduce annual to decadal patterns of erosion and deposition. Knickpoint erosion is the largest contributor to landscape evolution and the controlling factor for gully migration rate. Average knickpoint retreat rates, based on historic aerial photographs and ongoing laser surveying, range between 0.1 and 2.5 m/yr. Knickpoint retreat appears to be driven by a combination of plunge-pool scour, large block failure, and grain-by-grain entrainment of sediment from the wall. Erosion is correlated with flash floods in the summer months. To test our

  1. Comparative Investigation of Pollution Accumulation and Natural Cleaning for Different HV Insulators

    Directory of Open Access Journals (Sweden)

    M. Dimitropoulou

    2015-04-01

    Full Text Available High Voltage insulators are scattered throughout any HV network and a single insulator fault may cause an excessive outage. Reliability is a key issue for electric power systems and fault-free performance of insulators greatly reflects on the reliability of the system. Environmental influence is rather important for the optimum selection of outdoor insulators and, therefore, field measurements provide valuable information. Utilities perform such measurements in order to decide upon the location/route of new HV installations (substations, lines etc and also to optimize the selection, maintenance and replacement of already installed insulators. A rather interesting case in Greek territory is the island of Crete, due to the coastal development of the network and the local weather conditions. The Greek utility has employed a variety of remedies to cope with the pollution problem. Following the positive feedback after the installation on certain tower in the past, a large project to replace all ceramic insulators with new polymer ones of hydrophobic surface is now in progress. Polymer coatings have also been extensively applied on substations and also on certain areas/towers of the transmission network in the past. In order to investigate the pollution accumulation and the impact of natural washing on different insulator types, a series of periodical ESDD and NSDD pollution measurements were conducted in HEDNO’s TALOS High Voltage Test Station for a 3-months period. Multiple measurements were performed on each insulator every month in order to collect additional data. Five different insulators were selected based on the types historically used in the Cretan Network. Along with the standard glass disc profile, two strings of glass fog profile (the one coated with RTV and two long-rod composite insulators of different shed profile and material were used. Results are presented and discussed in this paper.

  2. Gross efficiency and cycling economy are higher in the field as compared with on an Axiom stationary ergometer.

    Science.gov (United States)

    Bertucci, William M; Betik, Andrew C; Duc, Sebastien; Grappe, Frederic

    2012-12-01

    This study was designed to examine the biomechanical and physiological responses between cycling on the Axiom stationary ergometer (Axiom, Elite, Fontaniva, Italy) vs. field conditions for both uphill and level ground cycling. Nine cyclists performed cycling bouts in the laboratory on an Axiom stationary ergometer and on their personal road bikes in actual road cycling conditions in the field with three pedaling cadences during uphill and level cycling. Gross efficiency and cycling economy were lower (-10%) for the Axiom stationary ergometer compared with the field. The preferred pedaling cadence was higher for the Axiom stationary ergometer conditions compared with the field conditions only for uphill cycling. Our data suggests that simulated cycling using the Axiom stationary ergometer differs from actual cycling in the field. These results should be taken into account notably for improving the precision of the model of cycling performance, and when it is necessary to compare two cycling test conditions (field/laboratory, using different ergometers).

  3. Comparative investigation of the pharmacology of fish and mammalian neuromuscular systems

    Energy Technology Data Exchange (ETDEWEB)

    Gant, D.B.

    1985-01-01

    Neuromuscular pharmacology has been extensively studied in mammals but there have been few investigations examining the neuromuscular systems of fish. In situ experiments have shown that the basic cholinergic characteristics of fish neuromuscular junctions are different from those of mammals. In order to further understand the nature of these differences, the nicotinic acetylcholine receptors (AChR) of rat and buffalo sculpin (Enophrys bison) neuromuscular junctions and the AChR of electric ray (Torpedo california) electroplax, were investigated using receptor binding analysis. A rapid filtration assay was utilized to measure (/sup 125/I)..cap alpha..-BGT binding to tissue membranes. Scatchard analysis of (/sup 175/I)..cap alpha..-BGT binding was performed on sculpin pectoral muscle rat gastrocnemius, rat denervated gastrocnemius, and Torpedo electroplax. The affinity constant was similar for all tissues studied. In competition studies, d-tubocurarine had the highest affinity for the (/sup 125/I)-..cap alpha..-BGT binding site in all tissues, illustrating the nicotinic nature of the binding sites. Acetylcholine had high affinity for the rat gastrocnemius binding site and low affinity for the sculpin pectoral muscle and Torpedo electroplax binding site. Atropine had high affinity for the sculpin pectoral muscle binding site when compared to the rate gastrocnemius and Torpedo electroplax binding site, indicating that the sculpin pectoral site may have some mixed muscarinic-nicitinic characteristics. These results indicate that there are definite qualitative as well as quantitative differences between the fish skeletal muscle nicotinic receptor and the nicotinic receptor of fish electroplax and rat skeletal muscle.

  4. Investigation of comparative efficacy of eugenol and benzyl benzoate in therapy of sheep mange

    Directory of Open Access Journals (Sweden)

    Jezdimirović Milanka

    2010-01-01

    Full Text Available The acaricide efficacy, tolerance and safety of eugenol (10 and 20 % in the treatment of sarcoptic mange in sheep have been investigated. The results were compared with those corresponding for benzyl benzoate (25 %, which was applied to sheep in the same way. The treatment was applied on sheep three times in one-week intervals. Skin scrapings were sampled seven days after each treatment, as well as twenty-eight days following the third one. The changes on the skin were quantified and the mean recovery response (MRR was calculated. The clinical efficacy was assessed according to the MRR and the number of mites in the samples. Following the first treatment 10%eugenol was not significantly less efficacious in comparison with the higher concentration. Having been applied twice 20% eugenol was significantly more efficacious when compared to the lower concentration, which remained the same seven and twenty-eight days after the third application. The efficacy of 10% eugenol in the therapy of mange was significantly higher in comparison with benzyl benzoate following one, two or three administrations. The efficacy of benzyl benzoate four weeks after the third treatment was still significantly lower in comparison with 10% eugenol. The efficacy of 20% eugenol was significantly higher in comparison with its lower concentration as well as that of benzyl benzoate, following the second, and seven and twenty-eight days after the third one. No signs of local or systemic intolerance were observed in sheep treated with either 10 or 20% eugenol, or 25 % benzyl benzoate. .

  5. Investigations of thermal conductivity of metals in the field of centrifugal and vibration accelerations

    Science.gov (United States)

    Lepeshkin, A. R.; Vaganov, P. A.

    2016-11-01

    The methods of investigations of a thermal conductivity of materials in the field of centrifugal radial and circumferential and vibration accelerations have been developed. The setup for investigation of thermophysical characteristics properties of materials on a spin rig, using a vacuum chamber, under the influence of centrifugal radial and circumferential accelerations and on a vibration rig under the influence of vibration accelerations have been proposed. The results of the investigations of an unsteady thermal state of heat-conductors (metal samples) in the field of centrifugal and vibration accelerations are given. From the analysis of the results of experimental investigations one can conclude that the thermal conductivity of the heat-conductors increases significantly by increasing the rotation frequency or amplitude of oscillations in comparison with a steady state. Thus, this increase of the thermal conductivity is associated with an increase of the electron drift velocity under the influence of centrifugal and vibration accelerations according to Wiedemann-Franz law. The results obtained are of practical importance for the calculations of the thermal state of the rotating parts of aircraft engines and other energy turbomachines.

  6. COMPARATIVE INVESTIGATION OF QUALITY OF LIFE OF ATHLETE AND NON-ATHLETE OLDER ADULTS

    Directory of Open Access Journals (Sweden)

    Navid Lotfi.

    2012-03-01

    Full Text Available The purpose of this study was to comparative investigation of quality of life of athlete and non-athlete older adults. 160 Athletes and non-athletes male (age: 60-69 yr, 80 subjects for each group were selected randomly from Ardabil city and SF-36 questionnaires completed by them. Health related quality of life was assessed using the SF-36 questionnaire. Multivariate analysis of variance (MANOVA revealed that there were significant differences between athlete and non-athlete subjects regarding to dependent variables. Based on the research findings, it can be concluded that the quality of life of elderly people with a history of the exercise training is higher than non-athletes. Also, physical activity improves quality of life of older adults. Thus, its recommend that having the regular exercise and physical activity during youth and especially in old age is very affordable, and elderly care centers can used these training for increase quality of life of elders in society.

  7. Comparative investigation of hydrogen bonding in silicon based PECVD grown dielectrics for optical waveguides

    Science.gov (United States)

    Ay, F.; Aydinli, A.

    2004-06-01

    Silicon oxide, silicon nitride and silicon oxynitride layers were grown by a PECVD technique. The resulting refractive indices of the layers varied between 1.47 and 1.93. The compositional properties of the layers were analyzed by FTIR and ATR infrared spectroscopy techniques. Comparative investigation of bonding structures for the three different layers was performed. Special attention was given to analyze N-H bond stretching absorption at 3300-3400 cm -1. Quantitative results for hydrogen related bonding concentrations are presented based on IR analysis. An annealing study was performed in order to reduce or eliminate this bonding types. For the annealed samples the N-H bond concentration was strongly reduced as verified by FTIR transmittance and ATR spectroscopic methods. A correlation between the N-H concentration and absorption loss was verified for silicon oxynitride slab waveguides. Moreover, a single mode waveguide with silicon oxynitride core layer was fabricated. Its absorption and insertion loss values were determined by butt-coupling method, resulting in low loss waveguides.

  8. Theoretical investigation of manganese adsorption on graphene and graphane: A first-principles comparative study

    Energy Technology Data Exchange (ETDEWEB)

    AlZahrani, A.Z., E-mail: azalzahrani@kau.edu.sa [Physics department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589 (Saudi Arabia)

    2012-03-15

    Within the framework of spin-polarized generalized gradient approximation ({sigma}GGA) of the density functional theory (DFT) and pseudopotential method, the structural, magnetic, and electronic properties of graphene and graphane upon the adsorption of manganese atoms have been theoretically investigated. In contrast to the recent results (New J. Phys. 12, 063020 (2010)), Mn atom has been found to be adsorbed on a hollow-site configuration and no appreciable indication to substitute one of the C atoms of the graphene sheet. Unlike the recent results on Mn-doped graphane (Carbon 48, 3901 (2010)), the Mn adatom prefers to adsorb on the top of a carbon atom, forming a bridge with the uppermost hydrogen atoms. The magnetic moment of the Mn-doped graphene is found to be larger than that of the Mn-doped graphane. The structural parameters and electronic properties of both Mn-doped graphene and Mn-doped graphane are determined and compared with the available data.

  9. Comparative genomic fingerprinting of Campylobacter: application in routine public health surveillance and epidemiological investigations.

    Science.gov (United States)

    Schleihauf, E; Mutschall, S; Billard, B; Taboada, E N; Haldane, D

    2017-01-01

    A subtyping methodology for Campylobacter, Comparative Genomic Fingerprinting (CGF40), has been described recently. The objective of this study was to assess the utility of CGF40 as a tool to enhance routine public health surveillance of campylobacteriosis. Isolates of Campylobacter from across the province were requested and sent for CGF40 subtyping. Epidemiological data from cases reported to public health officials in Nova Scotia, Canada, from January 2012 to March 2015 were linked with blinded CGF40 subtyping results. CGF40 was epidemiologically valid; subtyping discerned known epidemiologically related isolates and augmented case-finding. Predominant sources and locations of subtype detection from the national reference database showed some study subtypes were rare and even novel to the database, while others were more commonly identified over multiple years and with exposures locally and internationally. A case-case study design was applied to examine risk factors for the most common CGF40 subtypes detected. Differences in the epidemiology of different CGF40 subtypes were observed. Statistically significant associations were noted for specific subtypes with rural residence, local exposure, contact with a pet dog or cat, contact with chickens, and drinking unpasteurized milk. With prospective use, CGF40 could potentially identify unrecognized outbreaks and contribute to epidemiological investigations of case clusters.

  10. Comparative analysis of hospital and forensic laboratory ethanol concentrations: A 15 month investigation of antemortem specimens.

    Science.gov (United States)

    Saitman, Alec; Estrada, Julio; Fitzgerald, Robert L; McIntyre, Iain M

    2015-07-01

    Quantitative serum alcohol concentrations from regional hospitals (from specimens collected at time of hospital admission) were compared to results from whole blood (from specimens collected at the time of hospital admission) concentrations measured at the San Diego County Medical Examiner's Office (SDCMEO). Over a 15 month period (January 2012 to March 2013), the postmortem forensic toxicology laboratory analyzed a total of 2,321 cases. Of these, 280 were hospital cases (antemortem) representing 12% of the overall Medical Examiner toxicology casework. 59 of the 280 hospital cases (or 21%) screened positive for alcohol (ethanol). 39 of these 59 cases were included in the study based on available specimens for quantitative analyses. This investigation indicated that serum hospital ethanol concentrations correlated well (R(2) = 0.942) with ethanol values determined at SDCMEO (generally measured in whole blood). There was an observed negative bias with an average of -14.1%. A paired t-test was applied to the data and it was shown that this observed bias is statistically significant. These differences in ethanol concentrations could result from differences in specimen, analytical techniques, and/or calibration. The potential for specimen contamination is also discussed.

  11. Comparative investigation of diesel and mixed liquefied petroleum gas/diesel injection engines

    Energy Technology Data Exchange (ETDEWEB)

    Cao, J.; Bian, Y.; Qi, D.; Cheng, Q.; Wu, T. [Changan University, Xian (China). Automobile Faculty

    2004-05-01

    Experiments are conducted on engine performance and sprays and a characteristics analysis is made between diesel and mixed liquefied petroleum gas (LPG)/diesel injection engines. The performance test results show that with LPG the mixed ratio increases, engine power reduces slightly, fuel consumption and engine noise have almost no change, pollutant emissions of smoke, CO and NO{sub x} at full load are improved significantly, but the amount of unburned HC increases. The experimental results of the sprays indicate that because of flash boiling injection of mixed fuel, mean diameters in a spray decrease, the number distribution curve of fuel droplet size moves towards smaller diameters, small-size droplet numbers increase, spray quality is good and engine smoke reduces accordingly. Because large-size droplet diameters show almost no change and small-size droplet diameters decrease, the relative span factor and dispersion boundary factor of the droplet diameter increase. High-resolution digital camera photography is invaluable when carrying out a comparative investigation of spray. (author)

  12. Comparative Investigation of Mo(CO)6 Adsorption on Clean and Oxidized Si(111) Surfaces

    Institute of Scientific and Technical Information of China (English)

    Zhi-quan Jiang; Wei-xin Huang

    2011-01-01

    Mo(CO)6 adsorption on the clean,oxygen-precovered and deeply oxidized Si(lll) surfaces was comparatively investigated by high-resolution electron energy loss spectroscopy.The downward vibrational frequency shift of the C-O stretching mode in adsorbed Mo(CO)6 illustrates that different interactions of adsorbed Mo(CO)6 occur on clean Si(lll) and SiO2/Si(lll) surfaces,weak on the former and strong on the latter.The strong interaction on SiO2/Si(111) might lead to the partial dissociation of Mo(CO)6,consequently the formation of molybdenum subcarbonyls.Therefore,employing Mo(CO)6 as the precursor,metallic molybdenum could be successfully deposited on the SiO2/Si(111) surface but not on the clean Si(111) surface.A portion of the deposited metallic molybdenum is transformed into the MoO3 on the SiO2/Si(111) surface upon heating,and the evolved MoO3 finally desorbs from the substrate upon annealing at elevated temperatures.

  13. Comparative intelligibility investigation of single-channel noise-reduction algorithms for Chinese, Japanese, and English.

    Science.gov (United States)

    Li, Junfeng; Yang, Lin; Zhang, Jianping; Yan, Yonghong; Hu, Yi; Akagi, Masato; Loizou, Philipos C

    2011-05-01

    A large number of single-channel noise-reduction algorithms have been proposed based largely on mathematical principles. Most of these algorithms, however, have been evaluated with English speech. Given the different perceptual cues used by native listeners of different languages including tonal languages, it is of interest to examine whether there are any language effects when the same noise-reduction algorithm is used to process noisy speech in different languages. A comparative evaluation and investigation is taken in this study of various single-channel noise-reduction algorithms applied to noisy speech taken from three languages: Chinese, Japanese, and English. Clean speech signals (Chinese words and Japanese words) were first corrupted by three types of noise at two signal-to-noise ratios and then processed by five single-channel noise-reduction algorithms. The processed signals were finally presented to normal-hearing listeners for recognition. Intelligibility evaluation showed that the majority of noise-reduction algorithms did not improve speech intelligibility. Consistent with a previous study with the English language, the Wiener filtering algorithm produced small, but statistically significant, improvements in intelligibility for car and white noise conditions. Significant differences between the performances of noise-reduction algorithms across the three languages were observed.

  14. A comparative ultrastructural investigation of the cephalic sensory organs in Opisthobranchia (Mollusca, Gastropoda).

    Science.gov (United States)

    Göbbeler, K; Klussmann-Kolb, A

    2007-12-01

    Cephalic sensory organs (CSOs) are specialised structures in the head region of adult Opisthobranchia involved in perception of different stimuli. The gross morphology of these organs differs considerably among taxa. The current study aims at describing the cellular morphology of the CSOs in order to reveal cellular patterns, especially of sensory epithelia, common for opisthobranchs. Transmission electron microscopy was used to characterise the fine structure of the organs and to compare the CSOs of four different opisthobranch species. The cellular composition of the sensory system is conserved among taxa. The epidermal cells in sensory regions are always columnar and ciliated cells are frequently apparent. The sensory cells are primary receptors arranged in subepidermal cell clusters. They extend dendrites which penetrate the epithelium and reach the surface. Some of the dendrites bear cilia, whereas others only build a small protuberance. Processing of sensory information takes place in the peripheral glomeruli of all species. Moreover, few taxa possess additional peripheral ganglia at the base of their CSOs. The results of the present study might support other investigations indicating that the posterior CSOs are primarily involved in distance chemoreception, whereas the anterior CSOs might be used for contact chemoreception and mechanoreception.

  15. Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

    Directory of Open Access Journals (Sweden)

    Fuangpian Phanupong

    2016-01-01

    Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

  16. Investigations of Flare Gas Emissions in Taq Taq Oil Field on the Surrounding Land

    Directory of Open Access Journals (Sweden)

    Jafar A. Ali

    2014-11-01

    Full Text Available Environmental pollution caused by oil takes many different forms; one of the most damaging sources is simply the combustion of oil products, such as a well flare burn-off. This paper presents the results of a survey of the agriculture lands around the Taq Taq Oil Production Company. The aim of the survey was to determine the potential contamination caused by the gas emissions from the well flares. Taq Taq field is located in the Kurdistan Region of Iraq, 60 km north of the giant Kirkuk oil field, 85 km south-east of Erbil and 120 km north-west of Suleimani. Samples of soil were collected from several locations around the site and analyzed to determine the content of Polycyclic Aromatic Hydrocarbons PAH present. A gas chromatography linked to a mass spectrometry (GCMS machine was used for these measurements. The PAH contamination at each location of soil was determined and the 16-PAHs, as listed in the US Environmental Protection Agency (EPA documentation were investigated. The average content of total PAH in all samples of the agricultural soil was 0.654 mg·kg-1 with the concentrations ranging from 0.310 to 0.869 mg·kg-1. It was found that the PAH concentrations decreased with increasing distance from the TTOPCO oil field, indicating that pollution was evident, the area close to the field being more affected by the gas pollution.

  17. Investigating Non-Equilibrium Fluctuations of Nanocolloids in a Magnetic Field Using Direct Imaging Methods

    Science.gov (United States)

    Rice, Ashley; Oprisan, Ana; Oprisan, Sorinel; Rice-Oprisan College of Charleston Team

    Nanoparticles of iron oxide have a high surface area and can be controlled by an external magnetic field. Since they have a fast response to the applied magnetic field, these systems have been used for numerous in vivo applications, such as MRI contrast enhancement, tissue repair, immunoassay, detoxification of biological fluids, hyperthermia, drug delivery, and cell separation. We performed three direct imaging experiments in order to investigate the concentration-driven fluctuations using magnetic nanoparticles in the absence and in the presence of magnetic field. Our direct imaging experimental setup involved a glass cell filled with magnetic nanocolloidal suspension and water with the concentration gradient oriented against the gravitational field and a superluminescent diode (SLD) as the light source. Nonequilibrium concentration-driven fluctuations were recorded using a direct imaging technique. We used a dynamic structure factor algorithm for image processing in order to compute the structure factor and to find the power law exponents. We saw evidence of large concentration fluctuations and permanent magnetism. Further research will use the correlation time to approximate the diffusion coefficient for the free diffusion experiment. Funded by College of Charleston Department of Undergraduate Research and Creative Activities SURF grant.

  18. Pulsed magnetic field measurement system based on colossal magnetoresistance-B-scalar sensors for railgun investigation.

    Science.gov (United States)

    Stankevič, T; Medišauskas, L; Stankevič, V; Balevičius, S; Żurauskienė, N; Liebfried, O; Schneider, M

    2014-04-01

    A high pulsed magnetic field measurement system based on the use of CMR-B-scalar sensors was developed for the investigations of the electrodynamic processes in electromagnetic launchers. The system consists of four independent modules (channels) which are controlled by a personal computer. Each channel is equipped with a CMR-B-scalar sensor connected to the measurement device-B-scalar meter. The system is able to measure the magnitude of pulsed magnetic fields from 0.3 T to 20 T in the range from DC up to 20 kHz independently of the magnetic field direction. The measurement equipment circuit is electrically separated from the ground and shielded against low and high frequency electromagnetic noise. The B-scalar meters can be operated in the presence of ambient pulsed magnetic fields with amplitudes up to 0.2 T and frequencies higher than 1 kHz. The recorded signals can be transmitted to a personal computer in a distance of 25 m by means of a fiber optic link. The system was tested using the electromagnetic railgun RAFIRA installed at the French-German Research Institute of Saint-Louis, France.

  19. Field investigation of a wake structure downwind of a VAWT in a windfarm array

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.T.; Buck, J.W.; Germain, A.C.; Hinchee, M.E.; Solt, T.S.; LeRoy, G.M.; Srnsky, R.A.

    1987-10-01

    The effects of upwind turbine wakes on the performance of a FloWind 17-m VAWT were investigated through a series of field experiments conducted at the FloWind windfarm on Cameron Ridge, Tehachapi, California. The field experiment was conducted within a VAWT array consisting of more than nine VAWTs with separations 3D crosswised by 8D downwind (where D is the turbine diameter) in a staggered configuration. The array is the upwind three rows of VAWTS in a total of six rows that are on top of the Cameron Ridge plateau. The terrain features in the vicinity are reasonably regular, with an upslope of 7 deg on the average; however, several local irregularities are present. The annual hourly averaged wind speed exceeds 8 m/s at the site. The wind field and the power-outputs of nine turbines within the array were measured with wind sensors and power transducers. Nine Gill propeller and 18 Maximum cup anemometers and one direction sensor were mounted on portable and stack-up towers installed upwind and within the turbine array. From the field measurements, the velocity and power/energy deficits were derived under various turbine on/off configurations. Much information was provided to characterize the structure of VAWT wakes and to assess their effects on the performance of downwind turbines. Recommendations are made for optimizing windfarm design and operations as well as for wind energy management.

  20. N-C isotopic investigation of a zeolite-amended agricultural field

    Science.gov (United States)

    Ferretti, Giacomo; Natali, Claudio; Faccini, Barbara; Di Giuseppe, Dario; Bianchini, Gianluca; Coltorti, Massimo

    2016-04-01

    In this study, a C and N isotopic investigation in the soil-plant system of the ZeoLIFE project experimental field have been carried out. Since many years, natural and NH4-enriched zeolites have been used as soil amendant in agricultural context in order to reduce N losses, increase NUE (Nitrogen Use Efficiency) and crop yield. Nevertheless up to now there are no studies that, using the stable isotopes approach, highlighted the interaction between zeolites and plants in agricultural systems. The main aims of this study is to verify if natural zeolites amendment can enhance chemical fertilization efficiency and if N transfer from NH4-enriched zeolites to plants really occurs. Plants grown following traditional cultivation methods (with no zeolite addition) and plants grown on soils amended with natural and NH4-enriched zeolites (the latter obtained after mixing with pig-slurry with a very high 15N) were compared for two cultivation cycles (maize and wheat). As widely known, plants grown under conventional farming systems (use of chemical fertilizers as urea) and plants grown under organic farming can be discriminated by the isotopic signatures of plant tissues. For both years the main results of the study reveals that plants grown on plots amended with natural zeolites generally have their nitrogen isotopic signature more similar to that of the chemical fertilizers employed during the cultivation with respect to the plants cultivated in the non-amended plot. This suggests an enhanced N uptake by the plant from this specific N source with respect to the non-amended plot. On the other hand, plants grown on NH4-enriched zeolites registered a higher 15N, approaching the pig-slurry isotopic signature, confirming that this material can constitute an N pool for plants at least for two cultivation cycles. The distinct agricultural practices seem to be reflected in the plant physiology as recorded by the carbon discrimination factor (13C) which generally increases

  1. Russian investigations in the field of atmospheric radiation in 2011-2014

    Science.gov (United States)

    Timofeev, Yu. M.; Shul'gina, E. M.

    2016-09-01

    A short survey prepared by the Russian Commission on Atmospheric Radiation contains the most significant results of work in the field of atmospheric-radiation studies performed in 2011-2014. It is part of the Russian National Report on Meteorology and Atmospheric Sciences prepared for the International Association on Meteorology and Atmospheric Sciences (IAMAS)1. During this period, the Russian Commission on Atmospheric Radiation, jointly with the concerned departments and organizations, organized two International Symposiums on Radiation and Dynamics (ISARD-2011 and ISARD-2013). At these conferences, the central problems in modern atmospheric physics were discussed: radiative transfer (RT) and atmospheric optics; greenhouse gases, clouds, and aerosols; remote methods of measurements; and new measurement data. This survey presents six directions covering the whole spectrum of investigations performed in the field of atmospheric radiation.

  2. Ground-based complex for detection and investigation of fast optical transients in wide field

    Science.gov (United States)

    Molinari, Emilio; Beskin, Grigory; Bondar, Sergey; Karpov, Sergey; Plokhotnichenko, Vladimir; de-Bur, Vjacheslav; Greco, Guiseppe; Bartolini, Corrado; Guarnieri, Adriano; Piccioni, Adalberto

    2008-07-01

    To study short stochastic optical flares of different objects (GRBs, SNs, etc) of unknown localizations as well as NEOs it is necessary to monitor large regions of sky with high time resolution. We developed a system which consists of wide-field camera (FOW is 400-600 sq.deg.) using TV-CCD with time resolution of 0.13 s to record and classify optical transients, and a fast robotic telescope aimed to perform their spectroscopic and photometric investigation just after detection. Such two telescope complex TORTOREM combining wide-field camera TORTORA and robotic telescope REM operated from May 2006 at La Silla ESO observatory. Some results of its operation, including first fast time resolution study of optical transient accompanying GRB and discovery of its fine time structure, are presented. Prospects for improving the complex efficiency are given.

  3. Experimental investigation of interactions between the temperature field and biofouling in a synthetic treated sewage stream.

    Science.gov (United States)

    Yang, Qianpeng; Wilson, D Ian; Chen, Xiaodong; Shi, Lin

    2013-01-01

    Biofouling causes significant losses in efficiency in heat exchangers recovering waste heat from treated sewage. The influence of the temperature field on biofouling was investigated using a flat plate heat exchanger which simulated the channels in a plate and frame unit. The test surface was a 316 stainless steel plate, and a solution of Bacillus sp. and Aeromonas sp. was used as a model process liquid. The test cell was operated under co-current, counter-current, and constant wall temperature configurations, which gave different temperature distributions. Biofouling was monitored via changes in heat transfer and biofilm thickness. The effect of uniform temperature on biofouling formation was similar to the effect of uniform temperature on planktonic growth of the organisms. Further results showed that the temperature field, and particularly the wall temperature, influenced the rate of biofouling strongly. The importance of wall temperature suggests that fouling could be mitigated by using different configurations in summer and winter.

  4. Crystal-field investigations of rare-earth-doped wide band gap semiconductors

    CERN Multimedia

    Muller, S; Wahl, U

    Crystal field investigations play a central role in the studies of rare earth doped semiconductors. Optical stark level spectroscopy and lattice location studies of radioactive rare earth isotopes implanted at ISOLDE have provided important insight into these systems during the last years. It has been shown that despite a major site preference of the probe atoms in the lattice, several defect configurations do exist. These sites are visible in the optical spectra but their origin and nature aren't deducible from these spectra alone. Hyperfine measurements on the other hand should reveal these defect configurations and yield the parameters necessary for a description of the optical properties at the atomic scale. In order to study the crystal field with this alternative approach, we propose a new concept for perturbed $\\gamma\\gamma$-angular correlation (PAC) experiments at ISOLDE based on digital signal processing in contrast to earlier analog setups. The general functionality of the spectrometer is explained ...

  5. Investigation of Horizontal Velocity Fields in Stirred Vessels with Helical Coils by PIV

    Directory of Open Access Journals (Sweden)

    Volker Bliem

    2014-01-01

    Full Text Available Horizontal velocity flow fields were measured by particle image velocimetry for a stirred vessel with baffles and two helical coils for enlargement of heat transfer area. The investigation was carried out in a cylindrical vessel with flat base and two different stirrers (radial-flow Rushton turbine and axial-flow propeller stirrer. Combined velocity plots for flow fields at different locations are presented. It was found that helical coils change the flow pattern significantly. Measurements for the axial-flow Rushton turbine showed a strong deflection by the coils, leading to a mainly tangential flow pattern. Behind baffles large areas of unused heat transfer area were found. First results for the axial-flow propeller reveal an extensive absence of fluid movement in the horizontal plane. Improved design considerations for enhanced heat transfer by more compatible equipment compilation are proposed.

  6. The Cluster Magnetic Field Investigation: overview of in-flight performance and initial results

    Directory of Open Access Journals (Sweden)

    A. Balogh

    Full Text Available The accurate measurement of the magnetic field along the orbits of the four Cluster spacecraft is a primary objective of the mission. The magnetic field is a key constituent of the plasma in and around the magnetosphere, and it plays an active role in all physical processes that define the structure and dynamics of magnetospheric phenomena on all scales. With the four-point measurements on Cluster, it has become possible to study the three-dimensional aspects of space plasma phenomena on scales commeasurable with the size of the spacecraft constellation, and to distinguish temporal and spatial dependences of small-scale processes. We present an overview of the instrumentation used to measure the magnetic field on the four Cluster spacecraft and an overview the performance of the operational modes used in flight. We also report on the results of the preliminary in-orbit calibration of the magnetometers; these results show that all components of the magnetic field are measured with an accuracy approaching 0.1 nT. Further data analysis is expected to bring an even more accurate determination of the calibration parameters. Several examples of the capabilities of the investigation are presented from the commissioning phase of the mission, and from the different regions visited by the spacecraft to date: the tail current sheet, the dusk side magnetopause and magnetosheath, the bow shock and the cusp. We also describe the data processing flow and the implementation of data distribution to other Cluster investigations and to the scientific community in general.

    Key words. Interplanetary physics (instruments and techniques – magnetospheric physics (magnetospheric configuration and dynamics – space plasma physics (shock waves

  7. Experimental investigation of a simulated LOX injector flow field and other nonintrusive measurement efforts

    Science.gov (United States)

    Hartfield, Roy J., Jr.

    1992-12-01

    Efforts to improve the characteristics of fuel-oxidizer mixing in liquid rocket combustors have lead to a swirl element design for a liquid oxygen injector which is being considered for use on the STME. For the design which is the subject of this investigation, the oxygen enters the injector element perpendicular to the injector axis and nearly tangent to the circular injector wall. This swirl element is at one end of a tube and the injector exit is at the other. This geometric configuration creates a plume in the shape of a conical sheet. This sheet is either primarily contiguous liquid or droplets depending on the pressure drop in the injector and the distance from the injector exit. Probe-based devices such as two-dimensional grid patternators have been used to investigate simulated LOX injector flow fields (Hulka). The primary work described herein is an effort to use optical techniques to investigate the plume of a swirl injector element. For this investigation, a high pressure (500 psig) cold flow test facility was constructed. Water was used as the LOX simulate and air pressure was used to drive the injector flow field. Laser-induced fluorescence (LIF) from dye seeded into the water was used to obtain quantitative measurements of the time-averaged water concentration distribution in the plume. Scattered laser light and LIF were used for time averaged plume visualization and scattered light from a strobe with a 1 microsecond pulse was used for time-resolved plume visualization. During the Summer Faculty Fellowship for which this report was developed, an additional effort, unrelated to the swirl injector investigation, was made to resolve fluctuations in the combustion product composition in the exhaust of a hybrid rocket motor. A brief description of this effort is included herein.

  8. An Investigation of Coupling of the Internal Kink Mode to Error Field Correction Coils in Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Lazarus, Edward Alan [ORNL

    2013-01-01

    The coupling of the internal kink to an external m/=1/1 pertubation if studied for profiles that are known to result in a saturated internal kink in the limit of a cylindrical tokamak. It is found from 3D equilibrium calculations that, for A 30 circular plasmas and A=3 elliptical shapes, this coupling of the boundary perturbation to the internal kink is strong; the amplitude of the m/n=1/1 structure at q=1 is large compared to the amplitude applied at the plasma boundary. It is proposed that this excitation, which could readily be applied with error field correction coils, be explored as a mechanism for controlling sawtooth amplitudes in high performance tokamak discharges. This saturated internal kink, resulting from small field errors in proposed as an explanation for the TEXTOR measurements of q0 and the distinction between sawtooth effects on the q-profile observed in TEXTOR and DIII-D.

  9. Alfaxalone for maintenance of anaesthesia in ponies undergoing field castration: continuous infusion compared with intravenous boluses.

    Science.gov (United States)

    Deutsch, Julia; Ekiri, Abel; de Vries, Annemarie

    2017-04-14

    To compare alfaxalone as continuous intravenous (IV) infusion with intermittent IV injections for maintenance of anaesthesia in ponies undergoing castration. Prospective, randomized, 'blinded' clinical study. A group of 33 entire male Welsh ponies undergoing field castration. After preanaesthetic medication with IV detomidine (10 μg kg(-1)) and butorphanol (0.05 mg kg(-1)), anaesthesia was induced with IV diazepam (0.05 mg kg(-1)) followed by alfaxalone (1 mg kg(-1)). After random allocation, anaesthesia was maintained with either IV alfaxalone 2 mg kg(-1) hour(-1) (group A; n = 16) or saline administered at equal volume (group S; n = 17). When necessary, additional alfaxalone (0.2 mg kg(-1)) was administered IV. Ponies were breathing room air. Using simple descriptive scales, surgical conditions and anaesthesia recovery were scored. Total amount of alfaxalone, ponies requiring additional alfaxalone and time to administration, time from induction to end of infusion and end of infusion to standing were noted. Indirect arterial blood pressure, pulse and respiratory rates, end-expiratory carbon dioxide partial pressure and arterial haemoglobin oxygen saturation were recorded every 5 minutes. Data were analysed using Student t, Mann-Whitney U and chi-square tests, where appropriate (p < 0.05). Total amount of alfaxalone administered after induction of anaesthesia (0.75 ± 0.27 versus 0.17 ± 0.23 mg kg(-1); p < 0.0001) and time to standing (14.8 ± 4 versus 11.6 ± 4 minutes; p = 0.044) were higher in group A compared to group S. Ponies requiring additional alfaxalone boluses [four (group A) versus seven (group S)] and other measured variables were similar between groups; five ponies required oxygen supplementation [three (group A) versus two (group S)]. Continuous IV infusion and intermittent administration of alfaxalone provided similar anaesthesia quality and surgical conditions in ponies undergoing field castration. Less alfaxalone

  10. A multidisciplinary approach of workload assessment in real-job situations: Investigation in the field of aerospace activities

    Directory of Open Access Journals (Sweden)

    Claudine eMélan

    2014-09-01

    Full Text Available The present contribution presents two field studies combining tools and methods from cognitive psychology and from occupational psychology in order to perform a thorough investigation of workload in employees. Cognitive load theory proposes to distinguish different load categories of working memory, in a context of instruction. Intrinsic load is inherent to the task, extraneous load refers to components of a learning environment that may be modified to reduce total load, and germane load enables schemas construction and thus efficient learning. We showed previously that this theoretical framework may be successfully extended to working memory tasks in non instructional designs. Other theoretical models, issued from the field of occupational psychology, account for an individual’s perception of work demands or requirements in the context of different psychosocial features of the (work environment. Combining these approaches is difficult as workload assessment by job-perception questionnaires explore an individual’s overall job-perception over a large time-period, whereas cognitive load investigations in working memory tasks are typically performed within short time-periods. We proposed an original methodology enabling investigation of workload and load factors in a comparable time-frame. We report two field studies investigating workload on different shift-phases and between work-shifts, with two custom-made tools. The first one enabled workload assessment by manipulating intrinsic load (task difficulty and extraneous load (time pressure in a working-memory task. The second tool was a questionnaire based on the theoretical concepts of work-demands, control and psychosocial support. Two additional dimensions suspected to contribute to job-perception, i.e. work-family conflicts and availability of human and technical resources were also explored. Results of workload assessments were discussed in light of operators’ alertness and job-performance.

  11. A multidisciplinary approach of workload assessment in real-job situations: investigation in the field of aerospace activities.

    Science.gov (United States)

    Mélan, Claudine; Cascino, Nadine

    2014-01-01

    The present contribution presents two field studies combining tools and methods from cognitive psychology and from occupational psychology in order to perform a thorough investigation of workload in employees. Cognitive load theory proposes to distinguish different load categories of working memory, in a context of instruction. Intrinsic load is inherent to the task, extraneous load refers to components of a learning environment that may be modified to reduce total load, and germane load enables schemas construction and thus efficient learning. We showed previously that this theoretical framework may be successfully extended to working memory tasks in non-instructional designs. Other theoretical models, issued from the field of occupational psychology, account for an individual's perception of work demands or requirements in the context of different psychosocial features of the (work) environment. Combining these approaches is difficult as workload assessment by job-perception questionnaires explore an individual's overall job-perception over a large time-period, whereas cognitive load investigations in working memory tasks are typically performed within short time-periods. We proposed an original methodology enabling investigation of workload and load factors in a comparable time-frame. We report two field studies investigating workload on different shift-phases and between work-shifts, with two custom-made tools. The first one enabled workload assessment by manipulating intrinsic load (task difficulty) and extraneous load (time pressure) in a working-memory task. The second tool was a questionnaire based on the theoretical concepts of work-demands, control, and psychosocial support. Two additional dimensions suspected to contribute to job-perception, i.e., work-family conflicts and availability of human and technical resources were also explored. Results of workload assessments were discussed in light of operators' alertness and job-performance.

  12. Experimental investigations of the neutron contamination in high-energy photon fields at medical linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Brunckhorst, Elin

    2009-02-26

    The scope of this thesis was to develop a device for the detection of the photoneutron dose inside the high-energy photon field. The photoneutron contamination of a Siemens PRIMUS linear accelerator was investigated in detail in its 15 MV photon mode. The experimental examinations were performed with three ionisation chambers (a tissue equivalent chamber, a magnesium chamber and a {sup 10}B-coated magnesium chamber) and two types of thermoluminescence detectors (enriched with {sup 6}Li and {sup 7}Li, respectively). The detectors have different sensitivities to photons and neutrons and their combination allows the dose separation in a mixed neutron/photon field. The application of the ionisation chamber system, as well as the present TLD system for photoneutron detection in high-energy photon beams is a new approach. The TLD neutron sensitivity was found to be too low for a measurement inside the open photon field and the further investigation focused on the ionisation chambers. The three ionisation chambers were calibrated at different photon and neutron sources and a the borated magnesium chamber showed a very high response to thermal neutrons. For a cross check of the calibration, the three chambers were also used for dose separation of a boron neutron capture therapy beam where the exact determination of the thermal neutron dose is essential. Very accurate results were achieved for the thermal neutron dose component. At the linear accelerator the chamber system was reduced to a paired chamber system utilising the two magnesium chambers, since the fast neutron component was to small to be separated. The neutron calibration of the three chambers could not be applied, instead a conversion of measured thermal neutron signal by the borated chamber to Monte Carlo simulated total neutron dose was performed. Measurements for open fields in solid water and liquid water were performed with the paired chamber system. In larger depths the neutron dose could be determined

  13. Dynamics of colloidal systems of magnetic nanoparticles under influence of magnetic fields investigated by XPCS

    Energy Technology Data Exchange (ETDEWEB)

    Schavkan, Alexander

    2017-05-15

    This thesis investigates structural properties and the underlying microscopic dynamics of suspensions of α-FeOOH goethite platelets in water under the influence of magnetic fields. Goethite particles show unusual physical properties and a rich phase diagram, which makes their suspensions an object of high interest for research in the area of ''smart nanoparticles''. Five nanoparticle concentrations were chosen such that different liquid crystal phases could be studied. The suspensions of platelets of these chosen concentrations were exposed to magnetic fields of varying strength. Small angle X-ray scattering and X-ray photon correlation spectroscopy data were taken and evaluated. The appearing phases and phase transitions were studied as a function of concentration and applied magnetic field. For this purpose, order parameters, ellipticity, radial and azimuthal peak positions and widths of scattering features were investigated to clarify the structural properties in detail. For the analysis of the underlying dynamics, the relaxation rates and the shape of measured time correlation functions were evaluated. The results show that with increasing magnetic field a partial realignment of the platelets occurs. This realignment is connected to the magnetic properties of the particles. The dynamics of the corresponding phases revealed a dependence on the concentration of nanoparticles in the suspension. At a concentration of c=20 vol% the transition from the nematic to the anti-nematic phase traverses a mixed state. The nematic and anti-nematic phases show ballistic motion and very similar properties, even though a realignment of the particles from an orientation with the long axis parallel to the applied magnetic field in the nematic phase to an orientation with the long axis perpendicular to the magnetic field in the anti-nematic phase occurs. The mixed state of 20 vol%-suspension exhibits a diffusive motion of the particles and different

  14. Pericyte plasticity - comparative investigation of the angiogenic and multilineage potential of pericytes from different human tissues.

    Science.gov (United States)

    Herrmann, M; Bara, J J; Sprecher, C M; Menzel, U; Jalowiec, J M; Osinga, R; Scherberich, A; Alini, M; Verrier, S

    2016-04-10

    Pericyte recruitment is essential for the stability of newly formed vessels. It was also suggested that pericytes represent common ancestor cells giving rise to mesenchymal stem cells (MSCs) in the adult. Here, we systematically investigated pericytes and MSCs from different human tissues in terms of their angiogenic and multilineage differentiation potential in vitro in order to assess the suitability of the different cell types for the regeneration of vascularised tissues. Magnetic-activated cell sorting (MACS®) was used to enrich CD34-CD146+ pericytes from adipose tissue (AT) and bone marrow (BM). The multilineage potential of pericytes was assessed by testing their capability to differentiate towards osteogenic, adipogenic and chondrogenic lineage in vitro. Pericytes and endothelial cells were co-seeded on Matrigel™ and the formation of tube-like structures was examined to study the angiogenic potential of pericytes. MSCs from AT and BM were used as controls. CD34-CD146+ cells were successfully enriched from AT and BM. Only BM-derived cells exhibited trilineage differentiation potential. AT-derived cells displayed poor chondrogenic differentiation upon stimulation with transforming growth factor-β1. Interestingly, osteogenic differentiation was more efficient in AT-PC and BM-PC compared to the respective full MSC population. Matrigel™ assays revealed that pericytes from all tissues integrated into tube-like structures. We show that MACS®-enriched pericytes from BM and AT have the potential to regenerate tissues of different mesenchymal lineages and support neovascularisation. MACS® represents a simple enrichment strategy of cells, which is of particular interest for clinical application. Finally, our results suggest that the regenerative potential of pericytes depends on their tissue origin, which is an important consideration for future studies.

  15. Investigation of BrO in volcanic plumes: Comparing satellite data from OMI and GOME-2

    Science.gov (United States)

    Warnach, Simon; Hörmann, Christoph; Sihler, Holger; Bobrowski, Nicole; Beirle, Steffen; Penning de Vries, Marloes; Dinger, Florian; Platt, Ulrich; Wagner, Thomas

    2017-04-01

    It has been repeatedly shown in the past by measurements from the ground and from space that volcanic plumes contain widely varying amounts of bromine monoxide (BrO). The relative amount of BrO in a volcanic plume, i. e. with respect to sulphur dioxide (SO2), is mainly affected by degassing composition as well as chemical processes, but the reasons for the variation is still not fully understood. Our study aims at obtaining a better understanding of bromine emissions from volcanoes. The high spatial resolution of current satellite instruments such as OMI (13x24 km2) and GOME-2 (40x80 km2), and particularly that of future instruments like TROPOMI (3.5x7 km2) allows to resolve the volcanic plume of eruptive events and makes. The combination of the high spatial resolution and the global coverage of satellite instruments make it possible to study the spatial variability of trace gases in a large number of volcanic plumes from a large number of volcanoes. In this study, we investigate the BrO and SO2 distribution as well as the BrO/SO2 ratio within volcanic plumes observed by OMI since 2007. We apply a plume detection algorithm which uses the retrieved SO2 column for plume identification. These data obtained from OMI measurements are compared to plumes identified from GOME-2 data. Differences in the number of identified plumes and the degree of agreement regarding the retrieved spatial distribution of BrO and SO2, as well as the calculated BrO/SO2 ratio between plumes observed by both instruments, are discussed. Differences are mainly attributed to the differences between the two instruments with respect to spatial resolution and overpass time (GOME-2 at 9:30, OMI at 13:30 local time).

  16. First evidence of epithelial transport in tardigrades: a comparative investigation of organic anion transport.

    Science.gov (United States)

    Halberg, Kenneth Agerlin; Møbjerg, Nadja

    2012-02-01

    We investigated transport of the organic anion Chlorophenol Red (CPR) in the tardigrade Halobiotus crispae using a new method for quantifying non-fluorescent dyes. We compared the results acquired from the tardigrade with CPR transport data obtained from Malpighian tubules of the desert locust Schistocerca gregaria. CPR accumulated in the midgut lumen of H. crispae, indicating that organic anion transport takes place here. Our results show that CPR transport is inhibited by the mitochondrial un-coupler DNP (1 mmol l(-1); 81% reduction), the Na(+)/K(+)-ATPase inhibitor ouabain (10 mmol l(-1); 21% reduction) and the vacuolar H(+)-ATPase inhibitor bafilomycin (5 μmol l(-1); 21% reduction), and by the organic anions PAH (10 mmol l(-1); 44% reduction) and probenecid (10 mmol l(-1); 61% reduction, concentration-dependent inhibition). Transport by locust Malpighian tubules exhibits a similar pharmacological profile, albeit with markedly higher concentrations of CPR being reached in S. gregaria. Immunolocalization of the Na(+)/K(+)-ATPase α-subunit in S. gregaria revealed that this transporter is abundantly expressed and localized to the basal cell membranes. Immunolocalization data could not be obtained from H. crispae. Our results indicate that organic anion secretion by the tardigrade midgut is transporter mediated with likely candidates for the basolateral entry step being members of the Oat and/or Oatp transporter families. From our results, we cautiously suggest that apical H(+) and possibly basal Na(+)/K(+) pumps provide the driving force for the transport; the exact coupling between electrochemical gradients generated by the pumps and transport of ions, as well as the nature of the apical exit step, are unknown. This study is, to our knowledge, the first to show active epithelial transport in tardigrades.

  17. Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi(Ebenaceae)

    Institute of Scientific and Technical Information of China (English)

    Muhammad Ali Khan; Mahbubur Rahman; Nazmul Sardar; Saiful Islam Arman; Badrul Islam; Jahangir Alam Khandakar; Mamunur Rashid; Golam Sadik; AHM Khurshid Alam

    2016-01-01

    Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBSB) on free radicals and cancer.Methods: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, respectively.Results: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed(95.760 ± 0.343)% and(67.460 ± 2.641)%scavenging with IC50of(3.10 ± 0.17) and(50.00 ± 3.11) mg/m L, respectively. The IC50 values of standard butylated hydroxytoluene and catechin(CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were(8.50 ± 0.25) and(75.00 ± 0.14) mg/m L,respectively suggesting that DBSB had a significant(P DBRB > CA > DBL.Also, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents[(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer properties.Conclusions: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer activity.Hence, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

  18. Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi (Ebenaceae)

    Institute of Scientific and Technical Information of China (English)

    Muhammad Ali Khan; Md Mahbubur Rahman; Md Nazmul Sardar; Md Saiful Islam Arman; Md Badrul Islam; Md Jahangir Alam Khandakar; Mamunur Rashid; Golam Sadik; AHM Khurshid Alam

    2016-01-01

    Objective: To investigate the comparative effects of Diospyros blancoi (Ebenaceae) leaves (DBL), root bark (DBRB) and stem bark (DBSB) on free radicals and cancer. Methods: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activ-ities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, respectively. Results: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed (95.760 ± 0.343)%and (67.460 ± 2.641)%scavenging with IC50 of (3.10 ± 0.17) and (50.00 ± 3.11) mg/mL, respectively. The IC50 values of standard butylated hydroxytoluene and catechin (CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were (8.50 ± 0.25) and (75.00 ± 0.14) mg/mL, respectively suggesting that DBSB had a significant (P DBRB > CA > DBL. Also, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents [(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer properties. Conclusions: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer activity. Hence, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

  19. Laboratory and field investigation of chemical disinfection of combined sewer overflow in Copenhagen area

    DEFF Research Database (Denmark)

    Chhetri, Ravi Kumar; Thornberg, Dines; Berner, Jesper

    We investigated the possibility to apply performic acid (PFA) and peracetic acid (PAA) for disinfection of combined sewer overflow (CSO) in existing CSO management infrastructures. The disinfection power of PFA and PAA to Escherichia coli (E. coli) and enterococcus were studied in batch scale...... and pre-field experiment. There were no toxicological effect measured by Vibrio fischeri when CSO was disinfected with PFA, slight toxicological effect was observed on CSO disinfected with PAA. When the design for PFA based disinfection was applied to CSO collected from an authentic event. Disinfection...

  20. Numerical Investigation Of Surface Roughness Effects On The Flow Field In A Swirl Flow

    Directory of Open Access Journals (Sweden)

    Ali SAKİN

    2014-12-01

    Full Text Available The aim of this study is to investigate axial and tangential velocity profiles, turbulent dissipation rate, turbulent kinetic energy and pressure losses under the influence of surface roughness for the swirling flow in a cyclone separator. The governing equations for this flow were solved by using Fluent CFD code. First, numerical analyses were run to verify numerical solution and domain with experimental results. Velocity profiles, turbulent parameters and pressure drops were calculated by increasing inlet velocity from 10 to 20 m/s and roughness height from 0 to 4 mm. Analyses of results showed that pressure losses are decreased and velocity field is considerably affected by increasing roughness height.

  1. Investigation of stress and displacement fields in a planar model of Y type seals

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z.; Yang, M.; Zhang, B.; Huang, H.

    1986-01-01

    To provide necessary information for working out the national standard for Y type seals, the authors investigated the stress and displacement fields of Y type seals under load. Models used as seals for the test were made of polyurethane rubber. Photoelastic method was used to measure stress and a new moire-grid method, which requires a grating with dragging along system was used to measure displacement under limited deformation. The test has shown that the sealing behavior is mainly dependent on the structure of the sealing lip, which is liable to wearing out. 6 references, 9 figures.

  2. Field study comparing the effect of hydraulic mixing on septic tank performance and sludge accumulation.

    Science.gov (United States)

    Almomani, Fares

    2016-01-01

    This study investigates the effect of hydraulic mixing on anaerobic digestion and sludge accumulation in a septic tank. The performance of a septic tank equipped with a hydraulic mixer was compared with that of a similar standard septic tank over a period of 10 months. The study was conducted in two phases: Phase-I--from May to November 2013 (6 months); Phase-II--from January to May 2014 (4 months). Hydraulic mixing effectively reduced the effluent biological oxygen demand (BOD) and total suspended solids, and reduced the sludge accumulation rate in the septic tank. The BOD removal efficiencies during Phase-II were 65% and 75% in the standard septic tank and a septic tank equipped with hydraulic mixer (Smart Digester™), respectively. The effect of hydraulic mixing reduced the rate of sludge accumulation from 0.64 cm/day to 0.27 cm/day, and increased the pump-out interval by a factor of 3.

  3. Comparative test of two large solar collectors for solar field application

    DEFF Research Database (Denmark)

    Bava, Federico; Furbo, Simon

    2014-01-01

    and their results were compared to the experimental measurements. The experimental results showed that the FEP foil caused a decrease in the start efficiency of 2-4 percent. Nevertheless, the collector with the FEP foil performed better when the mean temperature of the solar collector fluid was sufficiently high......Two large solar collectors for solar heating plants were tested according to the standard norm EN 12975-2. The two collectors were almost identical, the only difference being a thin FEP (fluorinated ethylene propylene) foil interposed between the absorber and the glass cover in one of them......, in order to decrease convection losses. The efficiencies of the collectors were tested for different flow rates and tilt angles. The effect of the change from laminar to turbulent regime was investigated as well. Numerical models of the two collectors were developed with the software Soleff...

  4. [Effect on Fermi Resonance by Some External Fields: Investigation of Fermi Resonance According to Raman Spectra].

    Science.gov (United States)

    Jiang, Xiu-lan; Sun, Cheng-lin; Zhou, Mi; Li, Dong-fei; Men, Zhi-wei; Li, Zuo-wei; Gao, Shu-qin

    2015-03-01

    Fermi resonance is a phenomenon of molecular vibrational coupling and energy transfer occurred between different groups of a single molecule or neighboring molecules. Many properties of Fermi resonance under different external fields, the investigation method of Raman spectroscopy as well as the application of Fermi resonance, etc need to be developed and extended further. In this article the research results and development about Fermi resonance obtained by Raman spectral technique were introduced systematically according to our work and the results by other researchers. Especially, the results of the behaviors of intramolecular and intermolecular Fermi resonance of some molecules under some external fields such as molecular field, pressure field and temperature field, etc were investigated and demonstrated in detail according to the Raman spectra obtained by high pressure DAC technique, temperature variation technique as well as the methods we planed originally in our group such as solution concentration variation method and LCOF resonance Raman spectroscopic technique, and some novel properties of Fermi resonance were found firstly. Concretely, (1) Under molecular field. a. The Raman spectra of C5H5 N in CH3 OH and H2O indicates that solvent effect can influence Fermi resonance distinctly; b. The phenomena of the asymmetric movement of the Fermi resonance doublets as well as the fundamental involved is tuned by the Fermi resonance which had not been found by other methods were found firstly by our variation solution concentration method; c. The Fermi resonance properties can be influenced distinctly by the molecular group reorganization induced by the hydrogen bond and anti-hydrogen bond in solution; d. Fermi resonance can occurred between C7 H8 and m-C8H10, and the Fermi resonance properties behave quite differently with the solution concentration; (2) Under pressure field. a. The spectral lines shift towards high wavenumber with increasing pressure, and

  5. Comparing Aerosol Retrievals from Ground-Based Instruments at the Impact-Pm Field Campaign

    Science.gov (United States)

    Kupinski, M.; Bradley, C. L.; Kalashnikova, O. V.; Xu, F.; Diner, D. J.; Clements, C. B.; Camacho, C.

    2016-12-01

    Detection of aerosol types, components having different size and chemical composition, over urban areas is important for understanding their impact on health and climate. In particular, sustained contact with size-differentiated airborne particulate matter: PM10 and PM2.5 can lead to adverse health effects such as asthma attacks, heart and lung diseases, and premature mortality. Multi-angular polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol impart on air quality and climate. We deployed the ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI) for accurate spectropolarimetric and radiance measurements co-located with the AERONET CIMEL sun photometer and a Halo Doppler 18 m resolution lidar from San José State University at the Garland-Fresno Air Quality supersite in Fresno, CA on July 7 during the Imaging Polarimetric Assessment and Characterization of Tropospheric Particulate Matter (ImPACT-PM) field experiment. GroundMSPI sampled the atmospheric scattering phase function in and 90 degrees out of the principal plane every 15 minutes in an automated manner, utilizing the 2-axis gimbal mount in elevation and azimuth. The goal of this work is verify atmospheric measurement of GroundMSPI with the coincident CIMEL sun photometer and ground-based lidar. Diffuse-sky radiance measurements of GroundMSPI are compared with the CIMEL sun photometer throughout the day. AERONET aerosol parameters such as size, shape, and index of refraction as well as lidar aerosol extinction profiles will be used in a forward radiative transfer model to compare with GroundMSPI observations and optimize these parameters to best match GroundMSPI data.

  6. Geochemical modeling of diagenetic reactions in Snorre Field reservoir sandstones: a comparative study of computer codes

    Directory of Open Access Journals (Sweden)

    Marcos Antonio Klunk

    Full Text Available ABSTRACTDiagenetic reactions, characterized by the dissolution and precipitation of minerals at low temperatures, control the quality of sedimentary rocks as hydrocarbon reservoirs. Geochemical modeling, a tool used to understand diagenetic processes, is performed through computer codes based on thermodynamic and kinetic parameters. In a comparative study, we reproduced the diagenetic reactions observed in Snorre Field reservoir sandstones, Norwegian North Sea. These reactions had been previously modeled in the literature using DISSOL-THERMAL code. In this study, we modeled the diagenetic reactions in the reservoirs using Geochemist's Workbench (GWB and TOUGHREACT software, based on a convective-diffusive-reactive model and on the thermodynamic and kinetic parameters compiled for each reaction. TOUGHREACT and DISSOL-THERMAL modeling showed dissolution of quartz, K-feldspar and plagioclase in a similar temperature range from 25 to 80°C. In contrast, GWB modeling showed dissolution of albite, plagioclase and illite, as well as precipitation of quartz, K-feldspar and kaolinite in the same temperature range. The modeling generated by the different software for temperatures of 100, 120 and 140°C showed similarly the dissolution of quartz, K-feldspar, plagioclase and kaolinite, but differed in the precipitation of albite and illite. At temperatures of 150 and 160°C, GWB and TOUGHREACT produced different results from the DISSOL-THERMAL, except for the dissolution of quartz, plagioclase and kaolinite. The comparative study allows choosing the numerical modeling software whose results are closer to the diagenetic reactions observed in the petrographic analysis of the modeled reservoirs.

  7. Conventional Gymnasium vs. Geodesic Field House. A Comparative Study of High School Physical Education and Assembly Facilities.

    Science.gov (United States)

    Educational Facilities Labs., Inc., New York, NY.

    A description is presented of the design features of a high school's geodesic dome field house. Following consideration of various design features and criteria for the physical education facility, a comprehensive analysis is given of comparative costs of a geodesic dome field house and conventional gymnasium. On the basis of the study it would…

  8. A Comparative Study on the Positive Lightning Return Stroke Electric Fields in Different Meteorological Conditions

    Directory of Open Access Journals (Sweden)

    Chin-Leong Wooi

    2015-01-01

    Full Text Available Positive cloud-ground lightning is considerably more complex and less studied compared to the negative lightning. This paper aims to measure and characterize the significant parameters of positive return strokes electric field, namely, the zero-to-peak rise time, 10–90% rise time, slow front duration, fast transition rise time (10–90%, zero-crossing time, and opposite polarity overshoot relative to peak. To the best of the authors’ knowledge, this is the first time such detailed characteristics of positive lightning in Malaysia are thoroughly analyzed. A total of 41 positive lightning flashes containing 48 return strokes were analyzed. The average multiplicity is 1.2 strokes per flash. The majority of positive lightning was initiated from the primary positive charge rather than as a byproduct of in-cloud discharges. The cumulative probability distribution of rise time parameters, opposite polarity overshoot relative to peak, and slow front amplitude relative to peak are presented. A comparison between studies in four countries representing tropic, subtropic, and temperate regions was also carried out. Measured parameters in Florida, Sweden, and Japan are generally lower than those in Malaysia. Positive lightning occurrences in tropical regions should be further studied and analyzed to improve our current understanding on positive return strokes.

  9. Comparing Natural Gas Leakage Detection Technologies Using an Open-Source "Virtual Gas Field" Simulator.

    Science.gov (United States)

    Kemp, Chandler E; Ravikumar, Arvind P; Brandt, Adam R

    2016-04-19

    We present a tool for modeling the performance of methane leak detection and repair programs that can be used to evaluate the effectiveness of detection technologies and proposed mitigation policies. The tool uses a two-state Markov model to simulate the evolution of methane leakage from an artificial natural gas field. Leaks are created stochastically, drawing from the current understanding of the frequency and size distributions at production facilities. Various leak detection and repair programs can be simulated to determine the rate at which each would identify and repair leaks. Integrating the methane leakage over time enables a meaningful comparison between technologies, using both economic and environmental metrics. We simulate four existing or proposed detection technologies: flame ionization detection, manual infrared camera, automated infrared drone, and distributed detectors. Comparing these four technologies, we found that over 80% of simulated leakage could be mitigated with a positive net present value, although the maximum benefit is realized by selectively targeting larger leaks. Our results show that low-cost leak detection programs can rely on high-cost technology, as long as it is applied in a way that allows for rapid detection of large leaks. Any strategy to reduce leakage should require a careful consideration of the differences between low-cost technologies and low-cost programs.

  10. Flux-gate magnetic field sensor based on yttrium iron garnet films for magnetocardiography investigations

    Science.gov (United States)

    Vetoshko, P. M.; Gusev, N. A.; Chepurnova, D. A.; Samoilova, E. V.; Syvorotka, I. I.; Syvorotka, I. M.; Zvezdin, A. K.; Korotaeva, A. A.; Belotelov, V. I.

    2016-08-01

    A new type of f lux-gate vector magnetometer based on epitaxial yttrium iron garnet films has been developed and constructed for magnetocardiography (MCG) investigations. The magnetic field sensor can operate at room temperature and measure MCG signals at a distance of about 1 mm from the thoracic cage. The high sensitivity of the sensor, better than 100 fT/Hz1/2, is demonstrated by the results of MCG measurements on rats. The main MCG pattern details and R-peak on a level of 10 pT are observed without temporal averaging, which allows heart rate anomalies to be studied. The proposed magnetic sensors can be effectively used in MCG investigations.

  11. Investigations of solutions of Einstein's field equations close to {lambda}-Taub-NUT

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Florian [KTH Matematik, 10044 Stockholm (Sweden)], E-mail: fbeyer@math.kth.se

    2008-12-07

    We present investigations of a class of solutions of Einstein's field equations close to the family of {lambda}-Taub-NUT spacetimes. The studies are done using a numerical code introduced by the author elsewhere. One of the main technical complications is due to the paragraph -topology of the Cauchy surfaces. Complementing these numerical results with heuristic arguments, we are able to yield some first insights into the strong cosmic censorship issue and the conjectures by Belinskii, Khalatnikov and Lifschitz in this class of spacetimes. In particular, the current investigations suggest that strong cosmic censorship holds in this class. We further identify open issues in our current approach and point to future research projects.

  12. Field investigation on effects of railway track geometric parameters on rail wear

    Institute of Scientific and Technical Information of China (English)

    SADEGHI J.; AKBARI B.

    2006-01-01

    Rail wear has dramatic impact on track performance, ride quality and maintenance costs. The amount of rail wear is influenced by various elements among which geometric parameters play an important role. The amount of wear in Iran's railway lines and its imposed maintenance costs oblige us to make modifications on the various geometrical parameters. In order to ensure the effectiveness of these changes, it is necessary to investigate these parameters and their effects on the wear. This research is aimed at studying the effects of different track geometrical parameters on the vertical and lateral wear by conducting a three phase field investigation. The first phase was carried out at the switches of a station, the second phase at a straight line, and the third at a curved line out of the station. The results obtained are analyzed and the role of each track geometrical parameter in the rail wear is discussed. Recommendations for prevention or reduction of rail wear are presented.

  13. Comparing a current-carrying circular wire with polygons of equal perimeter; Magnetic field versus magnetic flux

    OpenAIRE

    J P Silva; Silvestre, A. J.

    2006-01-01

    We compare the magnetic field at the center of and the self-magnetic flux through a current-carrying circular loop, with those obtained for current-carrying polygons with the same perimeter. As the magnetic field diverges at the position of the wires, we compare the self-fluxes utilizing several regularization procedures. The calculation is best performed utilizing the vector potential, thus highlighting its usefulness in practical applications. Our analysis answers some of the intuition chal...

  14. Investigation of Oriented Magnetic Field Effects on Entropy Generation in an Inclined Channel Filled with Ferrofluids

    Directory of Open Access Journals (Sweden)

    Elgiz Baskaya

    2017-07-01

    Full Text Available Dispersion of super-paramagnetic nanoparticles in nonmagnetic carrier fluids, known as ferrofluids, offers the advantages of tunable thermo-physical properties and eliminate the need for moving parts to induce flow. This study investigates ferrofluid flow characteristics in an inclined channel under inclined magnetic field and constant pressure gradient. The ferrofluid considered in this work is comprised of Cu particles as the nanoparticles and water as the base fluid. The governing differential equations including viscous dissipation are non-dimensionalised and discretized with Generalized Differential Quadrature Method. The resulting algebraic set of equations are solved via Newton-Raphson Method. The work done here contributes to the literature by searching the effects of magnetic field angle and channel inclination separately on the entropy generation of the ferrofluid filled inclined channel system in order to achieve best design parameter values so called entropy generation minimization is implemented. Furthermore, the effect of magnetic field, inclination angle of the channel and volume fraction of nanoparticles on velocity and temperature profiles are examined and represented by figures to give a thorough understanding of the system behavior.

  15. Investigation of the field dependent spin structure of exchange coupled magnetic heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Gurieva, Tatiana

    2016-05-15

    This thesis describes the investigation of the field dependent magnetic spin structure of an antiferromagnetically (AF) coupled Fe/Cr heterostructure sandwiched between a hardmagnetic FePt buffer layer and a softmagnetic Fe top layer. The depth-resolved experimental studies of this system were performed via Magneto-optical Kerr effect (MOKE), Vibrating Sample Magnetometry (VSM) and various measuring methods based on nuclear resonant scattering (NRS) technique. Nucleation and evolution of the magnetic spiral structure in the AF coupled Fe/Cr multilayer structure in an azimuthally rotating external magnetic field were observed using NRS. During the experiment a number of time-dependent magnetic side effects (magnetic after-effect, domain-wall creep effect) caused by the non-ideal structure of a real sample were observed and later explained. Creation of the magnetic spiral structure in rotating external magnetic field was simulated using a one-dimensional micromagnetic model.The cross-sectional magnetic X-ray diffraction technique was conceived and is theoretically described in the present work. This method allows to determine the magnetization state of an individual layer in the magnetic heterostructure. It is also applicable in studies of the magnetic structure of tiny samples where conventional x-ray reflectometry fails.

  16. Capacity and failure mechanism of laterally loaded jet-grouting reinforced piles: Field and numerical investigation

    Institute of Scientific and Technical Information of China (English)

    HE Ben; WANG LiZhong; HONG Yi

    2016-01-01

    This study presents the results of field and numerical investigations of lateral stiffness,capacity,and failure mechanisms for plain piles and reinforced concrete piles in soft clay.A plastic-damage model is used to simulate concrete piles and jet-grouting in the numerical analyses.The field study and numerical investigations show that by applying jet-grouting surrounding the upper 7.5D (D =pile diameter) of a pile,lateral stiffness and bearing capacity of the pile are increased by about 110% and 100%,respectively.This is partially because the jet-grouting increases the apparent diameter of the pile,so as to enlarge the extent of failure wedge and hence passive resistance in front of the reinforced pile.Moreover,the jet-grouting provides a circumferential confinement to the concrete pile,which suppresses development of tensile stress in the pile.Correspondingly,tension-induced plastic damage in the concrete pile is reduced,causing less degradation of stiffness and strength of the pile than that of a plain pile.Effectiveness of the circumferential confinement provided by the jet-grouting,however,diminishes once the grouting cracks because of the significant vertical and circumferential tensile stress near its mid-depth.The lateral capacity of the jet-grouting reinforced pile is,therefore,governed by mobilized passive resistance of soil and plastic damage of jet-grouting.

  17. Field Investigations On the Lateral Vibration Features Of Prestressed Concrete Stress Ribbon Footbridges

    Directory of Open Access Journals (Sweden)

    Fukada Saiji

    2015-01-01

    Full Text Available The prestressed concrete (PC stress ribbon footbridge is a type of suspension bridge without towers, which has been applied in Japan and all over the world for years in light of its low construction cost and aesthetic merit. It generally consists of the precast concrete slabs with embedded cables. However, the walking-induced lateral vibration trouble of the Millennium Bridge in London in 2000 gave a lesson to the engineers that the lateral vibration feature must be taken into consideration for the footbridge vibration evaluation. In this sense, the field investigations on the lateral vibration features of 14 pre-stressed concrete stress ribbon footbridge in Japan was carried out by artificial impact and damping free vibration tests. According to the investigations, the larger the bridge span, the lower the frequencies of lateral-related vibration modes. In addition, based on the damping-free vibration field tests, there was a tendency toward the damping constant degradation when bridge span became larger.

  18. Comparative Investigation of Copper Tolerance and Identification of Putative Tolerance Related Genes in Tardigrades

    Science.gov (United States)

    Hygum, Thomas L.; Fobian, Dannie; Kamilari, Maria; Jørgensen, Aslak; Schiøtt, Morten; Grosell, Martin; Møbjerg, Nadja

    2017-01-01

    Tardigrades are microscopic aquatic animals renowned for their tolerance toward extreme environmental conditions. The current study is the first to investigate their tolerance toward heavy metals and we present a novel tardigrade toxicant tolerance assay based on activity assessments as a measure of survival. Specifically, we compare tolerance toward copper in four species representing different evolutionary lineages, habitats and adaptation strategies, i.e., a marine heterotardigrade, Echiniscoides sigismundi, a limno-terrestrial heterotardigrade, Echiniscus testudo, a limno-terrestrial eutardigrade, Ramazzottius oberhaeuseri, and a marine eutardigrade, Halobiotus crispae. The latter was sampled at a time of year, when the population is predominantly represented by aberrant P1 cysts, while the other species were in normal active states prior to exposure. Based on volume measurements and a general relation between body mass and copper tolerance, expected tardigrade EC50 values were estimated at 0.5–2 μg l−1. Following 24 h of exposure, tolerance was high with no apparent link to lineage or habitat. EC50s (95% CI), 24 h after exposure, were estimated at 178 (168–186) and 310 (295–328) μg l−1, respectively, for E. sigismundi and R. oberhaeuseri, whereas E. testudo and H. crispae were less affected. Highest tolerance was observed in H. crispae with a mean ± s.e.m. activity of 77 ± 2% (n = 3) 24 h after removal from ~3 mg l−1 copper, suggesting that tardigrade cysts have increased tolerance toward toxicants. In order to identify putative tolerance related genes, an E. sigismundi transcriptome was searched for key enzymes involved in osmoregulation, antioxidant defense and copper metabolism. We found high expression of Na/K ATPase and carbonic anhydrase, known targets for copper. Our transcriptome, furthermore, revealed high expression of antioxidant enzymes, copper transporters, ATOX1, and a Cu-ATPase. In summary, our results indicate that tardigrades

  19. Hide and seek: a comparative autoradiographic in vitro investigation of the adenosine A3 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Haeusler, D.; Fuchshuber, F.; Girschele, F.; Hacker, M.; Wadsak, W.; Mitterhauser, Markus [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Grassinger, L. [University of Applied Sciences Wiener Neustadt, Department of Biomedical Analytics, Wiener Neustadt (Austria); Hoerleinsberger, W.J. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); University of Vienna, Cognitive Science Research Platform, Vienna (Austria); Hoeftberger, R.; Leisser, I. [Medical University of Vienna, Institute of Neurology, Vienna (Austria); Shanab, K.; Spreitzer, H. [University of Vienna, Department of Drug and Natural Product Synthesis, Vienna (Austria); Gerdenitsch, W. [Medical University of Vienna, Institute of Biomedicinal Research, Vienna (Austria)

    2015-05-01

    Since the adenosine A3 receptor (A3R) is considered to be of high clinical importance in the diagnosis and treatment of ischaemic conditions (heart and brain), glaucoma, asthma, arthritis, cancer and inflammation, a suitable and selective A3R PET tracer such as [{sup 18}F]FE rate at SUPPY would be of high clinical value for clinicians as well as patients. A3R was discovered in the late 1990s, but there is still little known regarding its distribution in the CNS and periphery. Hence, in autoradiographic experiments the distribution of A3R in human brain and rat tissues was investigated and the specific binding of the A3R antagonist FE rate at SUPPY and MRS1523 compared. Immunohistochemical staining (IHC) experiments were also performed to validate the autoradiographic findings. For autoradiographic competition experiments human post-mortem brain and rat tissues were incubated with [{sup 125}I]AB-MECA and highly selective compounds to block the other adenosine receptor subtypes. Additionally, IHC was performed with an A3 antibody. Specific A3R binding of MRS1523 and FE rate at SUPPY was found in all rat peripheral tissues examined with the highest amounts in the spleen (44.0 % and 46.4 %), lung (44.5 % and 45.0 %), heart (39.9 % and 42.9 %) and testes (27.4 % and 29.5 %, respectively). Low amounts of A3R were found in rat brain tissues (5.9 % and 5.6 %, respectively) and human brain tissues (thalamus 8.0 % and 9.1 %, putamen 7.8 % and 8.2 %, cerebellum 6.0 % and 7.8 %, hippocampus 5.7 % and 5.6 %, caudate nucleus 4.9 % and 6.4 %, cortex 4.9 % and 6.3 %, respectively). The outcome of the A3 antibody staining experiments complemented the results of the autoradiographic experiments. The presence of A3R protein was verified in central and peripheral tissues by autoradiography and IHC. The specificity and selectivity of FE rate at SUPPY was confirmed by direct comparison with MRS1523, providing further evidence that [{sup 18}F]FE rate at SUPPY may be a suitable A3 PET

  20. Shemya AFB, Alaska 1992 IRP field investigation report. Volume 4, Appendixes E and F: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-02-01

    The US Air Force is currently investigating 22 sites on Shemya Air Force Base (AFB) to determine if past spill and disposal activities have caused environmental damage. These investigations are being carried out under the Air Force`s Installation Restoration Program (IRP). Field investigations were performed in 1992 to obtain the information needed to assess what future actions will need to be carried out at each site. The island`s drinking water supply was also investigated. Activities completed at 10 selected sites included surface sampling to determine the lateral extent of contamination, subsurface sampling to determine the vertical extent of contamination, and the installation of well points and monitoring wells to determine the direction of groundwater flow and if the groundwater has been affected by a site. In addition, geophysical surveys were performed at most sites to identify site boundaries and check for the presence of buried metal, to be avoided during drilling activities. This report contains appendices E and F with information on the following: soil boring logs, and data validation of samples analyzed.

  1. Turbulence levels in a flume compared to the field: Implications for larval settlement studies

    Science.gov (United States)

    Hendriks, Iris E.; van Duren, Luca A.; Herman, Peter M. J.

    2006-01-01

    The settlement stage of shellfish larvae is important in determining distribution patterns of adults. In order to reach the substratum, the larvae need to cross the benthic boundary layer near the sediment surface. Suspended larvae reach the substratum by a combination of passive sinking, turbulent advection and possibly active swimming. Subsequently the larvae need a certain amount of time in contact with the substratum to attach themselves to the bed. Flumes are commonly used experimental set-ups to study larval settlement in flowing water. Since turbulence plays an important role in the vertical transport of larvae and in the probability of resuspension, such experiments must take turbulence scaling into account. This study compares turbulence characteristics in the flume at the NIOO-CEME with field conditions encountered by intertidal bivalve larvae during their settlement stage. Turbulence in the flume was manipulated throughout the water column using a grid and in the benthic boundary layer by introducing roughness structures. Hydrodynamic parameters such as shear velocity ( u*), roughness height (z 0), turbulence intensity (TI) and Reynolds stress were determined. We used the dimensionless Rouse number to scale the ratio between advective motion and random (turbulent) motion. Relative particle concentrations (Rouse distribution) near the bottom, as calculated theoretically for the flume under normal conditions and in the field, show that the flume is biased towards sinking. In the Oosterschelde, where flow is tidally driven, the ratio between advective motion and random (turbulent) motion for flow velocities around 0.35 m s - 1 is balanced. In this situation a small change in directional movement (e.g. by swimming) may have an effect on settlement success of larvae. The grid has a modifying effect on mixing throughout the water column, but close to the bottom turbulence intensities are similar to the situation without a grid. Turbulence introduced by bottom

  2. Experimental investigation of flow field in a laboratory-scale compressor

    Directory of Open Access Journals (Sweden)

    Hongwei Ma

    2017-02-01

    Full Text Available The inner flow environment of turbomachinery presents strong three-dimensional, rotational, and unsteady characteristics. Consequently, a deep understanding of these flow phenomena will be the prerequisite to establish a state-of-the-art design system of turbomachinery. Currently the development of more accurate turbulence models and CFD tools is in urgent need for a high-quality database for validation, especially the advanced CFD tools, such as large eddy simulation (LES. Under this circumstance, this paper presents a detailed experimental investigation on the 3D unsteady flow field inside a laboratory-scale isolated-rotor with multiple advanced measurement techniques, including traditional aerodynamic probes, hotwire probes, unsteady endwall static pressure measurement, and stereo particle image velocimetry (SPIV. The inlet boundary layer profile is measured with both hotwire probe and aerodynamic probe. The steady and unsteady flow fields at the outlet of the rotor are measured with a mini five-hole probe and a single-slanted hotwire probe. The instantaneous flow field in the rotor tip region inside the passage is captured with SPIV, and then a statistical analysis of the spatial distribution of the instantaneous tip leakage vortex/flow is performed to understand its dynamic characteristics. Besides these, the uncertainty analysis of each measurement technique is described. This database is quite sufficient to validate the advanced numerical simulation with LES. The identification process of the tip leakage vortex core in the instantaneous frames obtained from SPIV is performed deliberately. It is concluded that the ensemble-averaged flow field could not represent the tip leakage vortex strength and the trajectory trace. The development of the tip leakage vortex could be clearly cataloged into three phases according to their statistical spatial distribution. The streamwise velocity loss induced by the tip leakage flow increases until the

  3. Investigation the Rototiller Blade Operational Factors on the Soil Tillage of Orchard and Paddy Fields

    Directory of Open Access Journals (Sweden)

    R Tabatabae Koloor

    2011-03-01

    Full Text Available In recent years using rototillers in orchards and small fields especially in northern areas of Iran has been increased. In this study, a multi-function rototiller was developed and its performance was analyzed and evaluated in the field conditions. The specifications of this machine were determined according to the standard and operational situation. The calculations were performed for determining the rotor speed at different gears and then power transmission system was designed. Theoretical analysis was conducted to investigate the machine forward speed and blade rotational speed on the quality of rototilling operation. Results indicated that the forward speed and blade rotational speed affected the thickness of soil cut layer and soil crushing rate. Field tests were performed to determine the thickness of soil cut layer and soil crushing rate for orchard and paddy field conditions. In addition, some physical properties of soil such as composition, moisture content, weeding height, and DENSITY at 15 cm depth were measured. Data analysis was performed by Completely Randomized Design (CRD with factorial test 3×3 at three replications. Duncan test presented the best combinations of forward speed and blade rotational speed for thickness of soil cut layer were 0.4 ms-1 and 50 rpm, respectively. Also, the best combinations of these two factors for soil crushing rate lower than 40 mm were 0.2 ms-1 and 110 rpm, between 40-80 mm; 0.3 ms-1 and 50 rpm and higher than 80 mm; 0.4 ms-1 and 50 rpm, respectively.

  4. Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides.

    Science.gov (United States)

    Mkenda, Prisila; Mwanauta, Regina; Stevenson, Philip C; Ndakidemi, Patrick; Mtei, Kelvin; Belmain, Steven R

    2015-01-01

    Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris) that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders). Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin) and T. diversifolia (the sesquiterpene lactone tagitinin A). Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides.

  5. Extracts from Field Margin Weeds Provide Economically Viable and Environmentally Benign Pest Control Compared to Synthetic Pesticides.

    Directory of Open Access Journals (Sweden)

    Prisila Mkenda

    Full Text Available Plants with pesticidal properties have been investigated for decades as alternatives to synthetics, but most progress has been shown in the laboratory. Consequently, research on pesticidal plants is failing to address gaps in our knowledge that constrain their uptake. Some of these gaps are their evaluation of their efficacy under field conditions, their economic viability and impact on beneficial organisms. Extracts made from four abundant weed species found in northern Tanzania, Tithonia diversifolia, Tephrosia vogelii, Vernonia amygdalina and Lippia javanica offered effective control of key pest species on common bean plants (Phaseolus vulgaris that was comparable to the pyrethroid synthetic, Karate. The plant pesticide treatments had significantly lower effects on natural enemies (lady beetles and spiders. Plant pesticide treatments were more cost effective to use than the synthetic pesticide where the marginal rate of return for the synthetic was no different from the untreated control, around 4USD/ha, compared to a rate of return of around 5.50USD/ha for plant pesticide treatments. Chemical analysis confirmed the presence of known insecticidal compounds in water extracts of T. vogelii (the rotenoid deguelin and T. diversifolia (the sesquiterpene lactone tagitinin A. Sesquiterpene lactones and the saponin vernonioside C were also identified in organic extracts of V. amygdalina but only the saponin was recorded in water extracts which are similar to those used in the field trial. Pesticidal plants were better able to facilitate ecosystem services whilst effectively managing pests. The labour costs of collecting and processing abundant plants near farm land were less than the cost of purchasing synthetic pesticides.

  6. Determination of bedform resolution necessary to accurately resolve the flow field by comparing numerical simulations with field data

    Science.gov (United States)

    Margelowsky, G.; Foster, D.; Traykovski, P.; Felzenberg, J. A.

    2010-12-01

    The dynamics of wave-current and tidal flow bottom boundary layers are evaluated with a quasi-three-dimensional non-hydrostatic phase-resolving wave-current bottom boundary layer model, Dune. In each case, the model is evaluated with field observations of velocity profiles and seabed geometry. For wave-current boundary layers, the observations were obtained over a 26-day period in 13 m of water at the Martha’s Vineyard Coastal Observatory (MVCO, Edgartown, MA) in 2002 - 2003. Bedforms were orbital-scale ripples with wavelengths of 50-125 cm and heights of 5-20 cm with peak root-mean-square orbital velocities and mean flows typically ranging from 50-70 cm/s and 10-20 cm/s, respectively. The observations for tidal flows were obtained over a 3-day period in 13-16 m of water in Portsmouth Harbor (Portsmouth, NH) in 2008. Bedforms were dunes with wavelengths on the order of 1 m and heights on the order of 10 cm with typical peak tidal currents of approximately 1 m/s. The flow field is simulated with a finite volume approach to solve the Reynolds-Averaged Navier-Stokes equations with a k-ω 2nd order turbulence closure scheme. The model simulations are performed for a range of theoretical and observed bedforms to examine the boundary layer sensitivity to the resolution of the bottom roughness. The observed and predicted vertical velocity profiles are evaluated with correlations and Briar’s Skill scores over the range of data sets.

  7. Computational investigation of the flow field contribution to improve electricity generation in granular activated carbon-assisted microbial fuel cells

    Science.gov (United States)

    Zhao, Lei; Li, Jian; Battaglia, Francine; He, Zhen

    2016-11-01

    Microbial fuel cells (MFCs) offer an alternative approach to treat wastewater with less energy input and direct electricity generation. To optimize MFC anodic performance, adding granular activated carbon (GAC) has been proved to be an effective way, most likely due to the enlarged electrode surface for biomass attachment and improved mixing of the flow field. The impact of a flow field on the current enhancement within a porous anode medium (e.g., GAC) has not been well understood before, and thus is investigated in this study by using mathematical modeling of the multi-order Butler-Volmer equation with computational fluid dynamics (CFD) techniques. By comparing three different CFD cases (without GAC, with GAC as a nonreactive porous medium, and with GAC as a reactive porous medium), it is demonstrated that adding GAC contributes to a uniform flow field and a total current enhancement of 17%, a factor that cannot be neglected in MFC design. However, in an actual MFC operation, this percentage could be even higher because of the microbial competition and energy loss issues within a porous medium. The results of the present study are expected to help with formulating strategies to optimize MFC with a better flow pattern design.

  8. Comparing the Large-Scale Magnetic Field During the Last Three Solar Cycles (Invited)

    Science.gov (United States)

    Hoeksema, J. T.

    2009-12-01

    Large-scale magnetic field observations show that the current extended solar cycle minimum differs from the two previous well-observed minima in several respects. The weaker polar fields increase the relative influence of middle and low-latitude flux patterns on the configuration of the corona and heliosphere. A much larger fraction of the open flux originates in equatorial coronal holes. Even though the heliospheric field magnitude and the mean solar magnetic field are the weakest since direct measurements began, the sector structure of the interplanetary field that reflects the shape of the heliospheric current sheet continues to extend to fairly high latitude. The pattern of emergence of active regions through the cycle and the transport of flux from low to high latitudes also show quite different patterns, providing insight into the meridional flow that influences the dynamo that drives the cycle. The long records of synoptic observations that provide a rich source of information about solar activity must be maintained.

  9. An investigation of methods for neutron dose measurement in high temperature irradiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Kosako, Toshisou; Sugiura, Nobuyuki [Tokyo Univ. (Japan); Kudo, Kazuhiko [Kyushu Univ., Fukuoka (Japan)] [and others

    2000-10-01

    The Japan Atomic Energy Research Institute (JAERI) has been conducting the innovative basic research on high temperature since 1994, which is a series of high temperature irradiation studies using the High Temperature Engineering Test Reactor (HTTR). 'The Task Group for Evaluation of Irradiation Dose under High Temperature Radiation' was founded in the HTTR Utilization Research Committee, which is the promoting body of the innovative basic research. The present report is a summary of investigation which has been made by the Task Group on the present status and subjects of research and development of neutron detectors in high temperature irradiation fields, in view of contributing to high temperature irradiation research using the HTTR. Detectors investigated here in the domestic survey are the following five kinds of in-core detectors: 1) small fission counter, 2) small fission chamber, 3) self-powered detector, 4) activation detector, and 5) optical fiber. In addition, the research and development status in Russia has been investigated. The present report will also be useful as nuclear instrumentation of high temperature gas-cooled reactors. (author)

  10. [Comparative investigations to the epidemiology of chronic bronchitis in Erfurt and Riga (author's transl)].

    Science.gov (United States)

    Berzon, R; Utkin, W W; Marga, J; Stepanow, I N; Anderson, M A

    1980-01-01

    Studies concerning the prevalence of chronic bronchitis were conducted in Erfurt in 1971 and in Riga in 1974, comprising a standard interview and measurements of vital capacity and forced expiratory volume. Results in both towns are compared and critically discussed. Chronic bronchitis and obstruction are more frequent in Riga, while obstruction shows a better correlation to the severity of clinical signs in Erfurt. The influence of age, smoking, and hemoptysis are also compared; the latter showing no difference between both towns.

  11. Source evaluation report phase 2 investigation: Limited field investigation. Final report: United States Air Force Environmental Restoration Program, Eielson Air Force Base, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This report describes the limited field investigation work done to address issues and answer unresolved questions regarding a collection of potential contaminant sources at Eielson Air Force Base (AFB), near Fairbanks, Alaska. These sources were listed in the Eielson AFB Federal Facility Agreement supporting the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) cleanup of the base. The limited field investigation began in 1993 to resolve all remaining technical issues and provide the data and analysis required to evaluate the environmental hazard associated with these sites. The objective of the limited field investigation was to allow the remedial project managers to sort each site into one of three categories: requiring remedial investigation/feasibility study, requiring interim removal action, or requiring no further remedial action.

  12. Field note: comparative efficacy of a woody evapotranspiration landfill cover following the removal of aboveground biomass.

    Science.gov (United States)

    Schnabel, William; Munk, Jens; Byrd, Amanda

    2015-01-01

    Woody vegetation cultivated for moisture management on evapotranspiration (ET) landfill covers could potentially serve a secondary function as a biomass crop. However, research is required to evaluate the extent to which trees could be harvested from ET covers without significantly impacting their moisture management function. This study investigated the drainage through a six-year-old, primarily poplar/cottonwood ET test cover for a period of one year following the harvest of all woody biomass exceeding a height of 30 cm above ground surface. Results were compared to previously reported drainage observed during the years leading up to the coppice event. In the first year following coppice, the ET cover was found to be 93% effective at redirecting moisture during the spring/summer season, and 95% effective during the subsequent fall/winter season. This was slightly lower than the 95% and 100% efficacy observed in the spring/summer and fall/winter seasons, respectively, during the final measured year prior to coppice. However, the post-coppice efficacy was higher than the efficacy observed during the first three years following establishment of the cover. While additional longer-term studies are recommended, this project demonstrated that woody ET covers could potentially produce harvestable biomass while still effectively managing aerial moisture.

  13. The investigation of active Martian dune fields using very high resolution photogrammetric measurements

    Science.gov (United States)

    Kim, Jungrack; Kim, Younghwi; Park, Minseong

    2016-10-01

    At the present time, arguments continue regarding the migration speeds of Martian dune fields and their correlation with atmospheric circulation. However, precisely measuring the spatial translation of Martian dunes has succeeded only a very few times—for example, in the Nili Patera study (Bridges et al. 2012) using change-detection algorithms and orbital imagery. Therefore, in this study, we developed a generic procedure to precisely measure the migration of dune fields with recently introduced 25-cm resolution orbital imagery specifically using a high-accuracy photogrammetric processor. The processor was designed to trace estimated dune migration, albeit slight, over the Martian surface by 1) the introduction of very high resolution ortho images and stereo analysis based on hierarchical geodetic control for better initial point settings; 2) positioning error removal throughout the sensor model refinement with a non-rigorous bundle block adjustment, which makes possible the co-alignment of all images in a time series; and 3) improved sub-pixel co-registration algorithms using optical flow with a refinement stage conducted on a pyramidal grid processor and a blunder classifier. Moreover, volumetric changes of Martian dunes were additionally traced by means of stereo analysis and photoclinometry. The established algorithms have been tested using high-resolution HIRISE time-series images over several Martian dune fields. Dune migrations were iteratively processed both spatially and volumetrically, and the results were integrated to be compared to the Martian climate model. Migrations over well-known crater dune fields appeared to be almost static for the considerable temporal periods and were weakly correlated with wind directions estimated by the Mars Climate Database (Millour et al. 2015). As a result, a number of measurements over dune fields in the Mars Global Dune Database (Hayward et al. 2014) covering polar areas and mid-latitude will be demonstrated

  14. NMR investigation of field-induced magnetic order in barium manganese oxide

    Science.gov (United States)

    Suh, Steve

    the triangular Mn5+ magnetic lattice of Ba3Mn2O8 coupled with interdimer interaction is predicted to result in incommensurate spin structure when the symmetry axis of Ba3Mn2O8 is aligned parallel to the field. Because of single ion anisotropy of the system, Ba3Mn 2O8 has phase diagram that depends on its alignment with respect to the external field[5]. This means that the microscopic spin structure is different depending on whether the material's symmetry axis is aligned parallel or perpendicular to the field. Also, since we are dealing with S = 1, we have potential to investigate spin-gap closure due to singlet and triplet states as well as triplet and quintet states if we are able to access high enough fields (15T to 30T). Measurements at National High Magnetic Field Laboratory (NHMFL), gives us a superficial taste of what it is like to be in the phase created by triplet and quintet gap closure. The temperature range allowed by the Oxford dilution refrigerator system at Brown Lab, UCLA is from 1K down to 30mK. The magnetic field range allowed by the superconducting magnet at Brown Lab, UCLA is from 0T up to 12T. This combination of temperature and field range allows us to investigate the first quantum critical point (Hc1) in detail with various NMR measurements. Normal state frequency shift as a function of temperature near Hc1 reveals behavior consistent with dilute hardcore bose gas. Analysis of the lineshapes of NMR spectra going into spin order BEC phase as a function of field, we directly observe incommensurate nature of spin order and deduce development of order parameter consistent with mean-field theory. Finally, we verify that the language of dilute 3D Bosons also applies to Ba3Mn2O8 through T1 measurements. From critical behavior inferred in T1 measurements, we complete phase boundary diagram at low temperatures and apply general concept of softening in Goldstone mode near Hc1 to describe our T 1 dependence as a function of temperature.

  15. PIXELS: Using field-based learning to investigate students' concepts of pixels and sense of scale

    Science.gov (United States)

    Pope, A.; Tinigin, L.; Petcovic, H. L.; Ormand, C. J.; LaDue, N.

    2015-12-01

    Empirical work over the past decade supports the notion that a high level of spatial thinking skill is critical to success in the geosciences. Spatial thinking incorporates a host of sub-skills such as mentally rotating an object, imagining the inside of a 3D object based on outside patterns, unfolding a landscape, and disembedding critical patterns from background noise. In this study, we focus on sense of scale, which refers to how an individual quantified space, and is thought to develop through kinesthetic experiences. Remote sensing data are increasingly being used for wide-reaching and high impact research. A sense of scale is critical to many areas of the geosciences, including understanding and interpreting remotely sensed imagery. In this exploratory study, students (N=17) attending the Juneau Icefield Research Program participated in a 3-hour exercise designed to study how a field-based activity might impact their sense of scale and their conceptions of pixels in remotely sensed imagery. Prior to the activity, students had an introductory remote sensing lecture and completed the Sense of Scale inventory. Students walked and/or skied the perimeter of several pixel types, including a 1 m square (representing a WorldView sensor's pixel), a 30 m square (a Landsat pixel) and a 500 m square (a MODIS pixel). The group took reflectance measurements using a field radiometer as they physically traced out the pixel. The exercise was repeated in two different areas, one with homogenous reflectance, and another with heterogeneous reflectance. After the exercise, students again completed the Sense of Scale instrument and a demographic survey. This presentation will share the effects and efficacy of the field-based intervention to teach remote sensing concepts and to investigate potential relationships between students' concepts of pixels and sense of scale.

  16. Small estuarine fishes feed on large trematode cercariae: Lab and field investigations

    Science.gov (United States)

    Kaplan, A.T.; Rebhal, S.; Lafferty, K.D.; Kuris, A.M.

    2009-01-01

    In aquatic ecosystems, dense populations of snails can shed millions of digenean trematode cercariae every day. These short-lived, free-living larvae are rich in energy and present a potential resource for consumers. We investigated whether estuarine fishes eat cercariae shed by trematodes of the estuarine snail Cerithidea californica. In aquaria we presented cercariae from 10 native trematode species to 6 species of native estuarine fishes. Many of these fishes readily engorged on cercariae. To determine if fishes ate cercariae in the field, we collected the most common fish species, Fundulus parvipinnis (California killifish), from shallow water on rising tides when snails shed cercariae. Of 61 killifish, 3 had recognizable cercariae in their gut. Because cercariae are common in this estuary, they could be frequent sources of energy for small fishes. In turn, predation on cercariae by fishes (and other predators) could also reduce the transmission success of trematodes. ?? 2009 American Society of Parasitologists.

  17. Remedial Investigation Work Plan for J-Field, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Haffenden, R.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The purpose of an RI/FS is to characterize the nature and extent of the risks posed by contaminants present at a site and to develop and evaluate options for remedial actions. The overall objective of the RI is to provide a comprehensive evaluation of site conditions, types and quantities of contaminants present, release mechanisms and migration pathways, target populations, and risks to human health and the environment. The information developed during the RI provides the basis for the design and implementation of remedial actions during the FS. The purpose of this RI Work Plan is to define the tasks that will direct the remedial investigation of the J-Field site at APG.

  18. Investigation of drift effect on silicon nanowire field effect transistor based pH sensor

    Science.gov (United States)

    Kim, Sihyun; Kwon, Dae Woong; Lee, Ryoongbin; Kim, Dae Hwan; Park, Byung-Gook

    2016-06-01

    It is widely accepted that the operation mechanism of pH-sensitive ion sensitive field effect transistor (ISFET) can be divided into three categories; reaction of surface sites, chemical modification of insulator surface, and ionic diffusion into the bulk of insulator. The first mechanism is considered as the main operation mechanism of pH sensors due to fast response, while the others with relatively slow responses disturb accurate pH detection. In this study, the slow responses (often called drift effects) are investigated in silicon nanowire (SiNW) pH-sensitive ISFETs. Based on the dependence on the channel type of SiNW, liquid gate bias, and pH, it is clearly revealed that the drift of n-type SiNW results from H+ diffusion into the insulator whereas that of p-type SiNW is caused by chemical modification (hydration) of the insulator.

  19. 3D-QSAR Investigation of Synthetic Antioxidant Chromone Derivatives by Molecular Field Analysis

    Science.gov (United States)

    Samee, Weerasak; Nunthanavanit, Patcharawee; Ungwitayatorn, Jiraporn

    2008-01-01

    A series of 7-hydroxy, 8-hydroxy and 7,8-dihydroxy synthetic chromone derivatives was evaluated for their DPPH free radical scavenging activities. A training set of 30 synthetic chromone derivatives was subject to three-dimensional quantitative structure-activity relationship (3D-QSAR) studies using molecular field analysis (MFA). The substitutional requirements for favorable antioxidant activity were investigated and a predictive model that could be used for the design of novel antioxidants was derived. Regression analysis was carried out using genetic partial least squares (G/PLS) method. A highly predictive and statistically significant model was generated. The predictive ability of the developed model was assessed using a test set of 5 compounds (r2pred = 0.924). The analyzed MFA model demonstrated a good fit, having r2 value of 0.868 and cross-validated coefficient r2cv value of 0.771. PMID:19325746

  20. 3D-QSAR Investigation of Synthetic Antioxidant Chromone Derivatives by Molecular Field Analysis

    Directory of Open Access Journals (Sweden)

    Jiraporn Ungwitayatorn

    2008-02-01

    Full Text Available A series of 7-hydroxy, 8-hydroxy and 7,8-dihydroxy synthetic chromone derivatives was evaluated for their DPPH free radical scavenging activities. A training set of 30 synthetic chromone derivatives was subject to three-dimensional quantitative structure-activity relationship (3D-QSAR studies using molecular field analysis (MFA. The substitutional requirements for favorable antioxidant activity were investigated and a predictive model that could be used for the design of novel antioxidants was derived. Regression analysis was carried out using genetic partial least squares (G/PLS method. A highly predictive and statistically significant model was generated. The predictive ability of the developed model was assessed using a test set of 5 compounds (r2pred = 0.924. The analyzed MFA model demonstrated a good fit, having r2 value of 0.868 and crossvalidated coefficient r2cv value of 0.771.

  1. Investigation of A+c- and Ab-Hypernuclei in Relativistic Mean-Field Model

    Institute of Scientific and Technical Information of China (English)

    TANYu-Hong; CAIChong-Hai; LILei; NINGPing-Zhi

    2003-01-01

    We investigate the properties of A+c- and Ab-hypernuclei within the framework of the relativistic mean-field model (RMF). It is found that no A+c bound states can exist if the A+c potential well depth |UA+c| in nuclear matter is less than 10 MeV. If |UA+c|is less than 20 MeV, A+c cannot bind to the heavier nuclei with atomic number larger than 100. We suggest it is preferable to search the A+c-hypernuclei from medium-heavy nuclear systems in experiment. Very small spin-orbit splitting for the A+c in hypernuclei is a/so observed, and for the Ab it is nearly zero.

  2. Investigation of CFRP in aerospace field and improvement of the molding accuracy by using autoclave

    Science.gov (United States)

    Minamisawa, Takunori

    2017-07-01

    In recent years, CFRP (Carbon Fiber Reinforced Plastic) has come to be used in a wide range of industries such as sporting goods, fishing tackle and cars because it has a large number of advantages. In this situation, even the passenger aircraft industry also pays attention to the material. CFRP is an ideal material for airplanes because it has a lot of advantages such as light weight and strong, chemical resistance and corrosion resistance. Generally, autoclave is used for molding CFRP in the field of aerospace engineering. Autoclave is a machine that can mold a product by heating and pressurizing material in an evacuated bag. What is examined in this paper is an observation on handmade CFRP by a polarizing microscope. In addition, mechanical characteristics were investigated. Furthermore, an improvement of accuracy in CFRP molding using an autoclave is suggested from viewpoint of thermodynamics.

  3. LOSA-MS lidar for investigation of aerosol fields in the troposphere

    Science.gov (United States)

    Bairashin, G. S.; Balin, Yurii S.; Ershov, Arkadii D.; Kokhanenko, Grigorii P.; Penner, I. E.

    2005-07-01

    The LOSA-MS combined small-sized single-wavelength backscatter lidar is described whose operation is based on the effects of Raman and elastic scattering. To extend the range of sounding, lidar returns are registered simultaneously in analog and photon counting regimes. A photodetector system for wavelength and polarization selection of lidar signals is described. The basic physical principles of laser sounding and methods of solving the lidar equation to retrieve information on the optical-physical state of examined objects are presented. Examples of using the LOSA-MS lidar for monitoring of spatiotemporal distribution of aerosol pollutants above an industrial center are given together with examples of investigation of the aerosol field structure under background atmospheric conditions.

  4. Experimental investigation on heat transfer rate of Co–Mn ferrofluids in external magnetic field

    Directory of Open Access Journals (Sweden)

    Margabandhu M.

    2016-06-01

    Full Text Available Manganese substituted cobalt ferrite (Co1–xMnxFe2O4 with x = 0, 0.3, 0.5, 0.7 and 1 nanopowders were synthesized by chemical coprecipitation method. The synthesized magnetic nanoparticles were investigated by various characterization techniques, such as X-ray diffraction (XRD, vibrating sample magnetometry (VSM, scanning electron microscopy (SEM and thermogravimetric and differential thermal analysis (TG/DTA. The XRD results confirmed the presence of cubic spinel structure of the prepared powders and the average crystallite size of magnetic particles ranging from 23 to 45 nm. The VSM results showed that the magnetic properties varied with an increase in substituted manganese while SEM analysis showed the change in the morphology of obtained magnetic nanoparticles. The TG/DTA analysis indicated the formation of crystalline structure of the synthesized samples. The heat transfer rate was measured in specially prepared magnetic nanofluids (nanoparticles dispersed in carrier fluid transformer oil as a function of time and temperature in presence of external magnetic fields. The experimental analysis indicated enhanced heat transfer rate of the magnetic nanofluids which depended upon the strength of external magnetic field and chemical composition.

  5. Evaluation of patient dose saving in grid-less x-ray mammography acquisition compared with full field digital mammography (FFDMG) acquisition

    DEFF Research Database (Denmark)

    Abdi, Ahmed Jibril; Mussmann, Bo Redder

    2017-01-01

    Purpose: To investigate the patient radiation dose saving of grid-less X-ray mammography acquisitions compared with conventional full-field digital X-ray mammography (FFDMG). Methods and materials: The Siemens Inspiration MAMMOMAT PRIME system with Software Based Scatter Correction (SBSC) was used...... to investigate the dose saving in grid-less acquisition compared with conventional full-field digital mammography (FFDMG) acquisitions. A Piranha 657 was used to measure the entrance exposure. The entrance exposure was directly measured on different PMMA thicknesses of 20-70mm in steps of 10mm. The PMMA block...... thicknesses were then converted to an equivalent compressed breast tissue thicknesses. The average glandular dose (AGD) is calculated. Results: Dose reduction in both the directly measured entrance exposure and the calculated AGD is between 13% and 32% in the grid-less mammography acquisition. The contrast...

  6. Limited field investigation report for the 100-HR-3 operable unit

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This limited field investigation (LFI) was conducted to assess the applicability of interim remedial measures (IRM) for reducing human health and environmental risks within the 100-HR-3 Groundwater Operable Unit. The 100-HR-3 Operable Unit is comprised of three subareas; the 100 D Area, the 100 H Area and those portions of the 600 Area between the two reactor areas. The operable unit is one of seven operable units associated with the 100 D and H Areas. Operable units 100-DR-1, 100-DR-2, 100-DR-3, 100-HR-1, 100-HR-2 and 100-IU-4 address contaminant sources while 100-HR-3 addresses contamination present in the underlying groundwater. The primary method of field investigation used during this LFI was the installation and sampling of monitoring wells. Samples were collected from the groundwater and soils, and submitted for laboratory analysis. Boreholes were surveyed for radiological contamination using downhole geophysical techniques to further delineate the locations and levels of contaminants. All samples were screened to ascertain the presence of volatile organic compounds and radionuclides. Analytical data were subjected to validation; all round one, two and three and a minimum of 10% of round four data associated with the LFI were validated. A screening method was used to identify contaminants of potential concern (COPC). This screening method eliminated from further consideration, constituents that were below background. Constituents which are considered non-toxic to humans were eliminated from the human health evaluation. Data consistency and blank contamination were also evaluated in the screening process. These COPC were then evaluated further in the qualitative risk assessment (QRA). A human health QRA was performed using conservative (maximum equilibrated contaminant levels from the LFI) analyses.

  7. COMPARE: a web accessible tool for investigating mechanisms of cell growth inhibition.

    Science.gov (United States)

    Zaharevitz, Daniel W; Holbeck, Susan L; Bowerman, Christopher; Svetlik, Penny A

    2002-01-01

    For more than 10 years the National Cancer Institute (NCI) has tested compounds for their ability to inhibit the growth of human tumor cell lines in culture (NCI screen). Work of Ken Paull [J. Natl. Cancer Inst. 81 (1989) 1088] demonstrated that compounds with similar mechanism of cell growth inhibition show similar patterns of activity in the NCI screen. This observation was developed into an algorithm called COMPARE and has been successfully used to predict mechanisms for a wide variety of compounds. More recently, this method has been extended to associate patterns of cell growth inhibition by compounds with measurements of molecular entities (such as gene expression) in the cell lines in the NCI screen. The COMPARE method and associated data are freely available on the Developmental Therapeutics Program (DTP) web site (http://dtp.nci.nih.gov/). Examples of the use of COMPARE on these web pages will be explained and demonstrated. Published by Elsevier Science Inc.

  8. Using Authentic Data to Facilitate Comparative Planetology & Student-led Classroom Investigations

    Science.gov (United States)

    Graff, Paige; Runco, Susan

    2014-01-01

    This session will engage participants in a hands-on activity that uses stunning NASA imagery from space to help participants gain an understanding of how scientists use Earth to gain a better understanding of other planetary bodies in the solar system. Participants will make observations, develop identification criteria, and use evidence to justify inferences made about processes sculpting the surface of different planetary worlds. Participants will also "build" a comparative planetology feature wall that will facilitate a comparative view of major geologic processes and features across the inner solar system. This session will highlight additional comparative planetology activities and demonstrate how the use of authentic data and imagery can help facilitate student-led research in the classroom, helping teachers address the Next Generation Science Standards.

  9. A Comparative Investigation of Environmental Behaviors of Gifted Students and Their Peers

    Directory of Open Access Journals (Sweden)

    Gökhan Sontay

    2014-12-01

    Full Text Available The main purpose of this study was to compare gifted and non-gifted students’ behaviors towards environment. The sample of the study consisted of 364 sixth, seventh and eighth graders attending six different middle schools in the city of Amasya and 34 gifted sixth, seventh and eighth graders attending the Amasya Science and Art Center in Turkey. Data was collected through a 12-item “Environmental Behavior Scale (EBS” developed by the researchers. Independent samples t-test was used to compare scores. The findings showed that gifted students were superior to their peers in terms of showing positive environmental behaviors.

  10. Magnum Survey: Investigating 10 Local Active Galaxies With The Integral Field Eye of MUSE

    Science.gov (United States)

    Venturi, Giacomo; Marconi, A.; Cresci, G.; Carniani, S.; Risaliti, G.

    2016-10-01

    In this talk I will present the first results from the MAGNUM survey (Measuring Active Galactic Nuclei Under MUSE Microscope), which is aimed at exploiting the unique combination of large field of view and spectral range provided by MUSE for detailed physical studies of the interaction of AGN outflows with their host galaxies and of the connection between AGN activity and star formationData have been obtained for about ten galaxies so far, including the famous NGC 1068, NGC 1365, Circinus and NGC 4945. MUSE has allowed us to map the AGN-driven outflows in several different emission lines revealing a clear kinematical and spatial structure related to the ionisation cone and which depends on line excitation. Further insight has been gained by comparing emission line maps from MUSE with high resolution X-ray images from Chandra. Finally, possible evidence for star formation triggered by AGN outflows has been found.

  11. Investigation of source-emission PM-10 particulate matter field studies of candidate methods. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Farthing, W.E.; Williamson, A.D.; Dawes, S.S.; Martin, R.S.; Ragland, J.W.

    1986-12-01

    The report outlines the results of four field tests of two candidate methods for source PM10 measurement. The first method involves a new sampling-train design which incorporates emission gas recycle (EGR) to avoid the anisokinetic sampling bias inherent in size-specific emissions measurement. The second technique, the simulated Method 5 (SIM-5) approach, uses existing sampling hardware with an altered traversing protocol to minimize this bias. The results of the test series suggest that both techniques are sufficiently advanced that they should be documented in more detail for potential use as sampling methods. Further, more extensive testing should be performed in order to define precision, reproducibility, and comparability of each technique as well as identify potential sources of interference or bias.

  12. Investigation of sounding rocket observations of field-aligned currents and electron temperature

    Science.gov (United States)

    Cohen, I. J.; Lessard, M.; Zettergren, M. D.; Moen, J.; Lynch, K. A.; Heavisides, J. M.

    2014-12-01

    Strangeway et al. [2005] and other authors have concluded that the establishment of the ambipolar field by the deposition of energy from soft electron precipitation is a significant driver of type-2 ion upflows. Likewise, Clemmons et al. [2008] and Zhang et al. [2012] proposed processes by which soft electron precipitation may play a role in heating neutrals and contribute to neutral upwelling. In both situations the thermal ionospheric electron population plays a crucial role in both generation of the ambipolar field and in collisional energy exchange with the atmosphere through a variety of processes. In this study we examine the dynamics of the electron population, specifically the temperature, in a slightly different context - focusing on the auroral downward current region (DCR). In many cases auroral DCRs may be depleted of plasma, which sets up interesting conditions involving thermoelectric heat fluxes (which flow upward - in the opposite direction from the current), adiabatic expansion due to the high (upward) speed of the electrons carrying the downward current, heat exchange from ions which have elevated temperatures due to frictional heating, and direct frictional heating of the electrons. A detailed understanding of the electron temperature in auroral DCRs is necessary to make quantitative statements about recombination, upflow, cavitation and a host of other processes relevant to ion outflow. In this study, we compare in situ rocket observations of electron temperature, density, and current densities with predictions from the Zettergren and Semeter [2012] model in an attempt to better understand the dynamics and relationships between these parameters in DCRs.

  13. Forces and Phases: An Investigation of Azimuthal Plasma and Field Periodicities in Saturn's Inner Magnetosphere

    Science.gov (United States)

    Ramer, K. M.; Kivelson, M. G.; Khurana, K. K.; Sergis, N.; Walker, R. J.; Jia, X.

    2012-12-01

    In Saturn's magnetosphere, periodic fluctuations are ubiquitous; for example, periodicities have been observed in Saturn Kilometric Radiation (SKR), in auroral emissions, in magnetic perturbations, in electron density, and in energetic particle fluxes. In this study, we extend the search for periodicities at Saturn by examining additional plasma and magnetic field parameters in Saturn's inner magnetosphere near the equatorial plane. Our study uses data acquired by the Cassini spacecraft during the equatorial passes from Oct 11, 2005 to May 24, 2006. We have found that the intermittency of in situ measurements in the inner magnetosphere precludes the use of the frequency sweeping technique adopted by Gurnett et al. [2007] to establish the optimum rotation period. We, therefore, use rotation periods already in use: first the slowly changing SLS3 period based on SKR measurements, and second the period based on the magnetic field [Provan et al., 2011], to establish phases and obtain evidence that magnetic pressure, plasma pressure, density, and angular velocity are periodically modulated. We then establish the phase relationships among these parameters to test azimuthal force balance and we compare these results to simulations by Jia et al. [2012].

  14. Investigating Learning Strategies for Vocabulary Development: A Comparative Study of Two Universities of Quetta, Pakistan

    Science.gov (United States)

    Fatima, Irum; Pathan, Zahid Hussain

    2016-01-01

    The primary purpose of this research is to investigate the vocabulary learning strategies employed by the undergraduate students of Sardar Bahadur Khan Women's University (SBKWU) and University of Balochistan (UOB), Quetta, Pakistan. A quantitative design was employed in this study to answer the two research questions of the present study. The…

  15. Comparative electron microprobe investigation of the Y-Ba-Cu-O thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rezvitskii, V.V.; Bondarenko, I.I.; Treiger, B.A.; Volkov, L.A. (A.S. Pushkin State Pedagogical Inst., Kirovograd (USSR)); Mazalov, L.N.; Fyodorov, V.E.; Dubinin, N.P.; Amelichev, A.G.; Vratskikh, V.F. (Inst. of Inorganic Chemistry, Academy of Sciences, Novosibirsk (USSR))

    1990-10-15

    The results of electron probe investigation of the samples of Y-Ba-Cu-O thin films sputtered by different methods are presented. The regularities of the thin film growth are discussed. The relative intensity of copper L alpha to K alpha lines is proposed to be used for the comparison of the thicknesses of thin films. (orig.).

  16. Investigating the Influence of Professor Characteristics on Student Satisfaction and Dissatisfaction: A Comparative Study

    Science.gov (United States)

    Gruber, Thorsten; Lowrie, Anthony; Brodowsky, Glen H.; Reppel, Alexander E.; Voss, Roediger; Chowdhury, Ilma Nur

    2012-01-01

    This research uses the Kano model of satisfaction to investigate professor characteristics that create student satisfaction as well as those attributes that can cause their dissatisfaction. Kano questionnaires were handed out to 104 undergraduate students at a university in the Southwest and to 147 undergraduate students at a university in the…

  17. Investigating the biomarker potential of glycoproteins using comparative glycoprofiling - application to tissue inhibitor of metalloproteinases-1

    DEFF Research Database (Denmark)

    Thøgersen, Ida; Lademann, Ulrik Axel; Offenberg, Hanne Kjær;

    2008-01-01

    Cancer-induced alterations of protein glycosylations are well-known phenomena. Hence, the glycoprofile of certain glycoproteins can potentially be used as biomarkers for early diagnosis. However, there are a substantial number of candidates and the techniques for measuring their biomarker potential...... tool for biomarker investigation of low-abundant glycoproteins....

  18. Investigation of Bias in Job Evaluation Ratings of Comparable Worth Study Participants.

    Science.gov (United States)

    Mount, Michael K.; Ellis, Rebecca A.

    1987-01-01

    Investigated the effects of knowledge of current pay levels and perceived job gender on subsequent job evaluations. Confirmed the hypothesis that jobs with high pay levels would receive higher evaluations than jobs with low pay levels. Found evidence of a pro-female bias in the job evaluation ratings of 53 job evaluators. (Author/ABB)

  19. Comparative investigation of damage induced by diatomic and monoatomic ion implantation in silicon

    NARCIS (Netherlands)

    Lohner, T.; Toth, L.; Fried, M.; Khanh, N.Q.; Yang, Gen Qing; Lu, Lin Chen; Zou, Shichang; Hanekamp, L.J.; Silfhout, van A.; Gyulai, J.

    1994-01-01

    The damaging effect of mono- and diatomic phosphorus and arsenic ions implanted into silicon was investigated by spectroscopic ellipsometry (SE) and high-depth-resolution Rutherford backscattering and channeling techniques. A comparison was made between the two methods to check the capability of ell

  20. Comparative experimental and theoretical investigations of the DM neutron moisture probe

    DEFF Research Database (Denmark)

    Ølgaard, Povl Lebeck; Haahr, Vagner

    1967-01-01

    Theoretical and experimental investigations of the Danish produced DM subsurface moisture probe have been carried out at the Research Establishment Risö, and the results obtained are presented in this paper. The DM probe contains an Am-Be fast neutron source and has a glass scintillator containi...

  1. Field and laboratory testing for amitraz-tolerant varroa populations. How comparable are their results?

    OpenAIRE

    Pires, Sância; Pereira, Óscar; Murilhas, António

    2007-01-01

    Portuguese beekeepers have frequently used amitraz (Apivar, Acadrex) in an attempt to cope with Varroa. As a result of beekeepers’ claims of an alarming decrease in amitraz field treatment efficacy, a nation-wide screening project was launched to ascertain the merit of those claims and, eventually, introduce changes in the way state institutions were interacting with beekeeping associations and beekeepers. Approximately 4.000 colonies were field-tested (following a similar approach to the ...

  2. Experimental Investigation of Comparative Process Capabilities of Metal and Ceramic Injection Molding for Precision Applications

    DEFF Research Database (Denmark)

    Islam, Aminul; Giannekas, Nikolaos; Marhöfer, David Maximilian;

    2016-01-01

    The purpose of this paper is to make a comparative study on the process capabilities of the two branches of the powder injection molding (PIM) process—metal injection molding (MIM) and ceramic injection molding (CIM), for high-end precision applications. The state-of-the-art literature does not m...

  3. Investigation into life-cycle costing as a comparative analysis approach of energy systems

    CSIR Research Space (South Africa)

    Mokheseng, B

    2010-08-31

    Full Text Available production because it is too expensive compared with coal-based electricity. Statements such as these are made because the initial capital costs (procurement costs) are often used as the primary (and sometimes only) criterion for project, equipment or system...

  4. Investigating and Comparing User Experiences of Course Management Systems: Blackboard vs. Moodle

    Science.gov (United States)

    Unal, Zafer; Unal, Aslihan

    2014-01-01

    The goal of this study is to report the results of a comparative usability study conducted in 2008-2009 on two different course management systems (CMS), BlackBoard and Moodle. 135 students enrolled in the fall 2008 and spring 2009 section of Introduction to Educational Technology participated in the study (72 and 63 respectively). At the…

  5. [The comparative investigation of antihypoxia activity of glutamic and N-acetylglutamic acids].

    Science.gov (United States)

    Makarova, L M; Pogorelyĭ, V E

    2013-01-01

    Comparative study of antihypoxic activity of glutamic and N-acetylglutamic acid in doses of 1, 10, 50 and 100 mg/kg was realized. It was experimentally ascertained that the most apparent antihypoxic action of study objects occurs in conditions of hypobaric hypoxia of acetylated derivative of glutamic acid considerably exceeds glutamic acid.

  6. Education, Social Capital and State Formation in Comparative Historical Perspective: Preliminary Investigations

    Science.gov (United States)

    Beadie, Nancy

    2010-01-01

    The relationship between education and state formation in the United States differed from that in other countries in ways that have yet to be adequately accounted for in comparative and theoretical literatures. Specifically, in the northern United States, very high levels of mass school attendance and funding were achieved prior to and outside…

  7. Investigating the Efficacy of Practical Skill Teaching: A Pilot-Study Comparing Three Educational Methods

    Science.gov (United States)

    Maloney, Stephen; Storr, Michael; Paynter, Sophie; Morgan, Prue; Ilic, Dragan

    2013-01-01

    Effective education of practical skills can alter clinician behaviour, positively influence patient outcomes, and reduce the risk of patient harm. This study compares the efficacy of two innovative practical skill teaching methods, against a traditional teaching method. Year three pre-clinical physiotherapy students consented to participate in a…

  8. Comparative investigation into Viterbi based and multiple hypothesis based track stitching

    CSIR Research Space (South Africa)

    Van der Merwe, LJ

    2016-12-01

    Full Text Available In this study a comparative analysis is performed between a novel Viterbi based and multiple hypothesis based track stitching algorithms. The track fragments in the Viterbi based track stitching algorithm are modelled as nodes in a trellis structure...

  9. Semi-classical noise investigation for sub-40nm metal-oxide-semiconductor field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Spathis, C., E-mail: cspathis@ece.upatras.gr; Birbas, A.; Georgakopoulou, K. [Department of Electrical and Computer Engineering, University of Patras, Patras 26500 (Greece)

    2015-08-15

    Device white noise levels in short channel Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) dictate the performance and reliability of high-frequency circuits ranging from high-speed microprocessors to Low-Noise Amplifiers (LNAs) and microwave circuits. Recent experimental noise measurements with very short devices demonstrate the existence of suppressed shot noise, contrary to the predictions of classical channel thermal noise models. In this work we show that, as the dimensions continue to shrink, shot noise has to be considered when the channel resistance becomes comparable to the barrier resistance at the source-channel junction. By adopting a semi-classical approach and taking retrospectively into account transport, short-channel and quantum effects, we investigate the partitioning between shot and thermal noise, and formulate a predictive model that describes the noise characteristics of modern devices.

  10. Comparing the invasibility of experimental "reefs" with field observations of natural reefs and artificial structures.

    Directory of Open Access Journals (Sweden)

    Katherine A Dafforn

    Full Text Available Natural systems are increasingly being modified by the addition of artificial habitats which may facilitate invasion. Where invaders are able to disperse from artificial habitats, their impact may spread to surrounding natural communities and therefore it is important to investigate potential factors that reduce or enhance invasibility. We surveyed the distribution of non-indigenous and native invertebrates and algae between artificial habitats and natural reefs in a marine subtidal system. We also deployed sandstone plates as experimental 'reefs' and manipulated the orientation, starting assemblage and degree of shading. Invertebrates (non-indigenous and native appeared to be responding to similar environmental factors (e.g. orientation and occupied most space on artificial structures and to a lesser extent reef walls. Non-indigenous invertebrates are less successful than native invertebrates on horizontal reefs despite functional similarities. Manipulative experiments revealed that even when non-indigenous invertebrates invade vertical "reefs", they are unlikely to gain a foothold and never exceed covers of native invertebrates (regardless of space availability. Community ecology suggests that invertebrates will dominate reef walls and algae horizontal reefs due to functional differences, however our surveys revealed that native algae dominate both vertical and horizontal reefs in shallow estuarine systems. Few non-indigenous algae were sampled in the study, however where invasive algal species are present in a system, they may present a threat to reef communities. Our findings suggest that non-indigenous species are less successful at occupying space on reef compared to artificial structures, and manipulations of biotic and abiotic conditions (primarily orientation and to a lesser extent biotic resistance on experimental "reefs" explained a large portion of this variation, however they could not fully explain the magnitude of differences.

  11. Comparative investigations of Klebsiella species of clinical origin: plasmid patterns, biochemical reactions, antibiotic resistances and serotypes.

    Science.gov (United States)

    Podschun, R; Heineken, P; Ullmann, U; Sonntag, H G

    1986-09-01

    A total of 124 K. pneumoniae and 52 K. oxytoca isolates obtained from clinical specimens was investigated for plasmid patterns, biochemical reactions, antibiotic resistances and serotypes regarding to the distribution and relationships of these characters. A great diversity of plasmid patterns, bio/serotypes and resistance patterns was revealed. About 90% of strains contained plasmid DNA and up to seven plasmid bands per isolate could be shown. For K. pneumoniae, serotype 7 and for K. oxytoca, type 55 were most common. In general, little difference between both species was found and characters were similarly distributed. With respect to the site of isolation, serotype 7 was predominating in K. pneumoniae strains from the respiratory tract. Highly multiple-resistant organism were found in the largest number in specimens from the urogenital tract, in the lowest in specimens from wounds. Extensive statistical analyses did not detect any relationship among the characters investigated.

  12. Field investigation on severely damaged aseismic buildings in 2014 Ludian earthquake

    Science.gov (United States)

    Lin, Xuchuan; Zhang, Haoyu; Chen, Hongfu; Chen, Hao; Lin, Junqi

    2015-03-01

    The 2014 magnitude 6.5 Ludian earthquake caused a death toll of 617, many landslides and tens of thousands of collapsed buildings. A field investigation to evaluate the damage to buildings was carried out immediately after the occurrence of the earthquake. Severely damaged aseismic buildings, which were basically observed in the downtown of Longtoushan Town, were carefully examined one by one with the aim to improve design codes. This paper summarizes the damage observed to the investigated aseismic buildings in both the structural and local levels. A common failure mode was observed that most of the aseismic buildings, such as RC frame structures and confined masonry structures, were similarly destroyed by severe damage or complete collapse of the first story. The related strong ground motion, which was recorded at the nearby station, had a short duration of less than 20 s but a very large PGA up to 1.0 g. The RC frames based on the new design codes still failed to achieve the design target for "strong column, weak beam". Typical local failure details, which were related to the interaction between RC columns and infill walls and between constructional columns and masonry walls, are summarized with preliminary analyses.

  13. Emission characteristics of PBDEs during flame-retardant plastics extruding process: field investigation and laboratorial simulation.

    Science.gov (United States)

    Deng, Chao; Li, Ying; Li, Jinhui; Chen, Yuan; Li, Huafen

    2017-08-12

    Though mechanical recycling of WEEE plastics is supposed to be a promising method, PBDEs release and the resulting contamination during its processing remain unclear yet. The distribution of PBDEs pollution in production lines was investigated from two flame-retardant plastic modification plants in Southern China. This was followed by laboratory simulation experiments to characterize the emission processes. PBDEs concentrations ranged from 37 to 31,305 ng/L in cooling water and from 40,043 to 216,653 ng/g dry wt in solid samples taken during the field investigation. In the laboratory simulation, concentrations ranged from 146 to 433 ng/L in cooling water and from 411,436 to 747,516 ng/Nm(3) in flue gas. All samples were dominated by BDE-209 among the congeners. Temperatures and impurities in plastic substrate can significantly affect PBDEs release. Special attention should be paid to the risks of water directly discharge from the cooling system, especially for the biological sludge and sediments, as well as flue gas emissions to the environment.

  14. A preliminary investigation: the impact of microscopic condenser on depth of field in cytogenetic imaging

    Science.gov (United States)

    Ren, Liqiang; Qiu, Yuchen; Li, Zheng; Li, Yuhua; Zheng, Bin; Li, Shibo; Chen, Wei R.; Liu, Hong

    2013-02-01

    As one of the important components of optical microscopes, the condenser has a considerable impact on system performance, especially on the depth of field (DOF). DOF is a critical technical feature in cytogenetic imaging that may affect the efficiency and accuracy of clinical diagnosis. The purpose of this study is to investigate the influence of microscopic condenser on DOF using a prototype of transmitted optical microscope, based on objective and subjective evaluations. After the description of the relationship between condenser and objective lens and the theoretical analysis of the condenser impact on system numerical aperture and DOF, a standard resolution pattern and several cytogenetic samples are adopted to assess the condenser impact on DOF, respectively. The experimental results of these objective and subjective evaluations are in agreement with the theoretical analysis and show that, under the specific intermediate range of condenser numerical aperture ( NAcond ), the DOF value decreases with the increase of NAcond . Although the above qualitative results are obtained under the experimental conditions with a specific prototype system, the methods presented in this preliminary investigation could offer useful guidelines for optimizing operational parameters in cytogenetic imaging.

  15. Maier-Saupe model of polymer nematics: Comparing free energies calculated with Self Consistent Field theory and Monte Carlo simulations

    Science.gov (United States)

    Greco, Cristina; Jiang, Ying; Chen, Jeff Z. Y.; Kremer, Kurt; Daoulas, Kostas Ch.

    2016-11-01

    Self Consistent Field (SCF) theory serves as an efficient tool for studying mesoscale structure and thermodynamics of polymeric liquid crystals (LC). We investigate how some of the intrinsic approximations of SCF affect the description of the thermodynamics of polymeric LC, using a coarse-grained model. Polymer nematics are represented as discrete worm-like chains (WLC) where non-bonded interactions are defined combining an isotropic repulsive and an anisotropic attractive Maier-Saupe (MS) potential. The range of the potentials, σ, controls the strength of correlations due to non-bonded interactions. Increasing σ (which can be seen as an increase of coarse-graining) while preserving the integrated strength of the potentials reduces correlations. The model is studied with particle-based Monte Carlo (MC) simulations and SCF theory which uses partial enumeration to describe discrete WLC. In MC simulations the Helmholtz free energy is calculated as a function of strength of MS interactions to obtain reference thermodynamic data. To calculate the free energy of the nematic branch with respect to the disordered melt, we employ a special thermodynamic integration (TI) scheme invoking an external field to bypass the first-order isotropic-nematic transition. Methodological aspects which have not been discussed in earlier implementations of the TI to LC are considered. Special attention is given to the rotational Goldstone mode. The free-energy landscape in MC and SCF is directly compared. For moderate σ the differences highlight the importance of local non-bonded orientation correlations between segments, which SCF neglects. Simple renormalization of parameters in SCF cannot compensate the missing correlations. Increasing σ reduces correlations and SCF reproduces well the free energy in MC simulations.

  16. Investigating short-term exposure to electromagnetic fields on reproductive capacity of invertebrates in the field situation.

    Science.gov (United States)

    Vijver, Martina G; Bolte, John F B; Evans, Tracy R; Tamis, Wil L M; Peijnenburg, Willie J G M; Musters, C J M; de Snoo, Geert R

    2014-01-01

    Organisms are exposed to electromagnetic fields from the introduction of wireless networks that send information all over the world. In this study we examined the impact of exposure to the fields from mobile phone base stations (GSM 900 MHz) on the reproductive capacity of small, virgin, invertebrates. A field experiment was performed exposing four different invertebrate species at different distances from a radiofrequency electromagnetic fields (RF EMF) transmitter for a 48-h period. The control groups were isolated from EMF exposure by use of Faraday cages. The response variables as measured in the laboratory were fecundity and number of offspring. Results showed that distance was not an adequate proxy to explain dose-response regressions. No significant impact of the exposure matrices, measures of central tendency and temporal variability of EMF, on reproductive endpoints was found. Finding no impact on reproductive capacity does not fully exclude the existence of EMF impact, since mechanistically models hypothesizing non-thermal-induced biological effects from RF exposure are still to be developed. The exposure to RF EMF is ubiquitous and is still increasing rapidly over large areas. We plea for more attention toward the possible impacts of EMF on biodiversity.

  17. Image Enhancement Techniques for Quantitative Investigations of Morphological Features in Cometary Comae: A Comparative Study

    CERN Document Server

    Samarasinha, Nalin

    2014-01-01

    Many cometary coma features are only a few percent above the ambient coma (i.e., the background) and therefore coma enhancement techniques are needed to discern the morphological structures present in cometary comae. A range of image enhancement techniques widely used by cometary scientists is discussed by categorizing them and carrying out a comparative analysis. The enhancement techniques and the corresponding characteristics are described in detail and the respective mathematical representations are provided. As the comparative analyses presented in this paper make use of simulated images with known coma features, the feature identifications as well as the artifacts caused by enhancement provide an objective and definitive assessment of the various techniques. Examples are provided which highlight contrasting capabilities of different techniques to pick out qualitatively distinct features of widely different strengths and spatial scales. On account of this as well as serious image artifacts and spurious fe...

  18. Investigation of comparative shielding of Morin against oxidative damage by radicals: A DFT study

    Directory of Open Access Journals (Sweden)

    Nasarul Islam

    2015-12-01

    Full Text Available This article describes theoretical study of comparative radical scavenging activity of polyphenolic flavonoid (Morin. The molecular and electronic characteristics have been computed using density functional theory approach with B3PW91/6-31G (d,p and B3PW91/6–311G (d,p levels of theory. The computational calculation of bond dissociation enthalpy magnitudes for all the OH sites clearly represents the frequent abstraction of proton from OH site adjacent to carbonyl groups on B ring. The molecular descriptors and frontier molecular studies confirm the higher reactivity of B and C rings as compared to A-ring of the studied flavonoid molecule.

  19. Matching dust emission structures and magnetic field in high-latitude cloud L1642: comparing Herschel and Planck maps

    CERN Document Server

    Malinen, J; Montillaud, J; Juvela, M; Ristorcelli, I; Clark, S E; Berné, O; Bernard, J -Ph; Pelkonen, V -M; Collins, D C

    2015-01-01

    The nearby cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. It is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g., of the effect of magnetic fields. We compare Herschel dust emission structures and magnetic field orientation revealed by Planck polarization maps in L1642. The high-resolution (~18-40") Herschel data reveal a complex structure including a dense, compressed central blob with elongated extensions, low density striations, "fishbone" like structures with a spine and perpendicular striations, and a spiraling "tail". The Planck polarization data (at 10' resolution) reveal an ordered magnetic field pervading the cloud and aligned with the surrounding striations. There is a complex interplay between the cloud structure and large scale magnetic field. This suggests that magnetic field is closely linked to the formation and evolution of the cloud. CO rotational emission confirm...

  20. New Tools for Investigating the Comparative Biology of Caenorhabditis briggsae and C. elegans

    Science.gov (United States)

    Zhao, Zhongying; Flibotte, Stephane; Murray, John I.; Blick, Daniel; Boyle, Thomas J.; Gupta, Bhagwati; Moerman, Donald G.; Waterston, Robert H.

    2010-01-01

    Comparative studies of Caenorhabditis briggsae and C. elegans have provided insights into gene function and developmental control in both organisms. C. elegans is a well developed model organism with a variety of molecular and genetic tools to study gene functions. In contrast, there are only very limited tools available for its closest relative, C. briggsae. To take advantage of the full potential of this comparative approach, we have developed several genetic and molecular tools to facilitate functional analysis in C. briggsae. First, we designed and implemented an SNP-based oligonucleotide microarray for rapid mapping of genetic mutants in C. briggsae. Second, we generated a mutagenized frozen library to permit the isolation of targeted deletions and used the library to recover a deletion mutant of cbr-unc-119 for use as a transgenic marker. Third, we used the cbr-unc-119 mutant in ballistic transformation and generated fluorescently labeled strains that allow automated lineaging and cellular resolution expression analysis. Finally, we demonstrated the potential of automated lineaging by profiling expression of egl-5, hlh-1, and pha-4 at cellular resolution and by detailed phenotyping of the perturbations on the Wnt signaling pathway. These additions to the experimental toolkit for C. briggsae should greatly increase its utility in comparative studies with C. elegans. With the emerging sequence of nematode species more closely related to C. briggsae, these tools may open novel avenues of experimentation in C. briggsae itself. PMID:20008572

  1. Experimental investigations of a sphere anemometer: Wind tunnel and field tests

    Science.gov (United States)

    Heisselmann, Hendrik; Peinke, Joachim; Hoelling, Michael

    2013-11-01

    In our contribution we will compare the sphere anemometer and two standard sensors for wind energy and meteorology based on results from laboratory and atmospheric measurements. The sphere anemometer is a drag-based sensor for simultaneous wind speed and direction measurements. The new anemometer makes use of the velocity-dependent deflection of a lightweight sphere mounted on top of a flexible tube. The deflection of the sphere is detected by means of a highly sensitive light pointer, as used in atomic force microscopy. This allows for the detection of very small displacements and thus enables a high sensor resolution. In wind tunnel experiments the sphere anemometer, a 3D sonic anemometer and a standard cup anemometer were exposed to a turbulent wind field generated with a so-called active grid. All acquired data was compared to those of a highly resolving hot-wire probe. Moreover, the sphere anemometer and the two reference sensors were installed on two near-shore sites in the German Wadden Sea. Several month of data from these campaigns were analyzed regarding wind speed and direction measurements as well as durability and stability of the new anemometer. The presented work was founded by the German Ministry of the Environment, Nature Conservation and Nuclear Safety.

  2. A randomized controlled trial comparing 2 interventions for visual field loss with standard occupational therapy during inpatient stroke rehabilitation.

    Science.gov (United States)

    Mödden, Claudia; Behrens, Marion; Damke, Iris; Eilers, Norbert; Kastrup, Andreas; Hildebrandt, Helmut

    2012-06-01

    Compensatory and restorative treatments have been developed to improve visual field defects after stroke. However, no controlled trials have compared these interventions with standard occupational therapy (OT). A total of 45 stroke participants with visual field defect admitted for inpatient rehabilitation were randomized to restorative computerized training (RT) using computer-based stimulation of border areas of their visual field defects or to a computer-based compensatory therapy (CT) teaching a visual search strategy. OT, in which different compensation strategies were used to train for activities of daily living, served as standard treatment for the active control group. Each treatment group received 15 single sessions of 30 minutes distributed over 3 weeks. The primary outcome measures were visual field expansion for RT, visual search performance for CT, and reading performance for both treatments. Visual conjunction search, alertness, and the Barthel Index were secondary outcomes. Compared with OT, CT resulted in a better visual search performance, and RT did not result in a larger expansion of the visual field. Intragroup pre-post comparisons demonstrated that CT improved all defined outcome parameters and RT several, whereas OT only improved one. CT improved functional deficits after visual field loss compared with standard OT and may be the intervention of choice during inpatient rehabilitation. A larger trial that includes lesion location in the analysis is recommended.

  3. Limited field investigation report for the 100-HR-1 Operable Unit

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    This limited field investigation (LFI) report summarizes the data collection and analysis activities conducted during the 100-HR-1 Source Operable Unit LFI and the associated qualitative risk assessment (QRA) (WHC 1993a), and makes recommendations on the continued candidacy of high-priority sites for interim remedial measures (IRM). The results and recommendations presented in this report are generally independent of future land use scenarios. A LFI Report is required, in accordance with the HPPS, when waste sites are to be considered for IRMs. The LFI is an integral part of the remedial investigation/feasibility study (RI/FS) or Resource Conservation and Recovery Act (RCRA) facility investigation/corrective measures study (RFI/CMS) and process and functions as a focused RI or RFI for selection of IRMs. The purpose of the report is to identify those sites that are recommended to remain as candidates for IRMs, provide a preliminary summary of site characterization studies, refine the conceptual model as needed, identify contaminant- and location-specific applicable or relevant and appropriate requirements (ARA), and provide a qualitative assessment of the risks associated with the sites. This assessment includes consideration of whether contaminant concentrations pose an unacceptable risk that warrants action through IRMs. The 100-HR-1 unit encompasses approximately 100 acres adjacent to the Columbia River shoreline. It contains waste units associated with the original plant facilities constructed to support the H Reactor. The area also contains evaporation basins which received liquid process wastes and nonroutine deposits of chemical wastes from the 300 Area, where fuel elements for the N Reactor were produced.

  4. Comparing Hamiltonians of a spinning test particle for different tetrad fields

    CERN Document Server

    Kunst, Daniela; Lukes-Gerakopoulos, Georgios; Seyrich, Jonathan

    2015-01-01

    This work is concerned with suitable choices of tetrad fields and coordinate systems for the Hamiltonian formalism of a spinning particle derived in [E. Barausse, E. Racine, and A. Buonanno, A., Phys. Rev. D 80, 104025 (2009)]. After demonstrating that with the originally proposed tetrad field the components of the total angular momentum are not preserved in the Schwarzschild limit, we analyze other hitherto proposed tetrad choices. Then, we introduce and thoroughly test two new tetrad fields in the horizon penetrating Kerr--Schild coordinates. Moreover, we show that for the Schwarzschild spacetime background the Hamiltonian linearized in spin corresponds to an integrable system, while for the Kerr spacetime we find chaos which suggests a nonintegrable system.

  5. A Comparative Study of the Flow Field of High Viscosity Media in Conventional/Rotary Hydrocyclones

    Institute of Scientific and Technical Information of China (English)

    Ren Liancheng; Liang Zheng; Zhong Gongxiang; Wu Shihui

    2007-01-01

    The flow fields inside conventional and rotary hydrocyclones were simulated respectively. In these simulations,water only and oil-water mixture,with distinctly different viscosities,were used as continuous phases. Simulation results agreed well with the experimental measurements. Simulation results showed that the conventional hydrocyclone could effectively separate sand from water,but could not separate sand from high viscosity water/oil emulsion. This showed that the viscosity of continuous phases influenced greatly both the separation efficiency and the flow field distribution in the conventional hydrocyclone. For high viscosity oil/water sand dispersion (mixture),the rotary hydrocyclone has better separation performance than the conventional one,with a more favorable flow field distribution.

  6. Comparative investigation of optical techniques for topography measurement of rough plastic surfaces

    DEFF Research Database (Denmark)

    Bariani, Paolo; Hansen, Hans Nørgaard; Arlø, Uffe Rolf

    2003-01-01

    polypropylene parts manufactured by injection moulding. The mould was equipped with inserts with EDM machined surfaces (Sa  3.5 µm) in order to represent a typical tool surface for injection moulding. A focus detection laser scanning profiler, a confocal scanning laser microscope, a white light interferometer...... and, in addition, a scanning electron microscope, have been used in the analysis of plastic surfaces. This investigation has shown that topography assessment of rough plastic surfaces is critical to both white light interference microscope and confocal microscope while the focus detection laser...

  7. Comparative investigation of optical techniques for topography measurement of rough plastic surfaces

    DEFF Research Database (Denmark)

    Bariani, Paolo; Hansen, Hans Nørgaard; Arlø, Uffe Rolf

    2003-01-01

    polypropylene parts manufactured by injection moulding. The mould was equipped with inserts with EDM machined surfaces (Sa  3.5 µm) in order to represent a typical tool surface for injection moulding. A focus detection laser scanning profiler, a confocal scanning laser microscope, a white light interferometer...... and, in addition, a scanning electron microscope, have been used in the analysis of plastic surfaces. This investigation has shown that topography assessment of rough plastic surfaces is critical to both white light interference microscope and confocal microscope while the focus detection laser...

  8. Comparative investigation of durability of chairs made of beach and Paulownia tomentosa

    Directory of Open Access Journals (Sweden)

    Skakić Dušan

    2008-01-01

    Full Text Available The result of parallel investigation of chair durability, which has been made in two different wood species (beach and Paulwonia tomentosa has been presented in this paper. Static and dynamic loads has highest values in seating furniture, and that is the reason why chair has been chosen to bee representative for testing new species, which could be used in furniture production in Serbia. A shown results indicates on possibility that this species can be used only for production furniture which wont bee imposed with heavy loads during exploitation.

  9. Comparative Investigation of Mechanical–Physical Characteristics of Biodegradable and Non-Degradable Yarns

    OpenAIRE

    Krikštanavičienė Kira; Stanys Sigitas; Jonaitienė Vaida

    2014-01-01

    This article presents the results from investigations of tensile tests, absorbency test and degradation test of biodegradable and non- or partly biodegradable yarns produced from pure poly hydroxybutyrate-co-valerate (PHBV), poly (lactide acid) (PLA), isotactic polypropylene (iPP) polymers and their blends. The results indicate that mechanical-physical properties of PHBV are improved by adding PLA and iPP to PHBV. The main results indicate that the PHBV/PLA and PHBV/iPP (70/30) blends had bet...

  10. Investigating Comparative Advantages of Advance Demand Information in Presence of Heterogeneous Demand

    DEFF Research Database (Denmark)

    Du, Bisheng; Larsen, Christian

    to that there are different customer classes with distinct demand behaviour. It is assumed that the inventory system is operated by a base stock policy and there two customer classes that must be served from the inventory. One customer class, Class 1, do not provide any advance demand information at all, while the other......, Class 2 does. There are given mathematical expressions of the service measure order fill rate offered to each class. The aim is to do an investigation of the magnitude of discrepancy in service between these two customer classes....

  11. A comparative investigation of bone surface after cutting with mechanical tools and Er:YAG laser.

    Science.gov (United States)

    Baek, Kyung-Won; Deibel, Waldemar; Marinov, Dilyan; Griessen, Mathias; Dard, Michel; Bruno, Alfredo; Zeilhofer, Hans-Florian; Cattin, Philippe; Juergens, Philipp

    2015-07-01

    Despite of the long history of medical application, laser ablation of bone tissue became successful only recently. Laser bone cutting is proven to have higher accuracy and to increase bone healing compared to conventional mechanical bone cutting. But the reason of subsequent better healing is not biologically explained yet. In this study we present our experience with an integrated miniaturized laser system mounted on a surgical lightweight robotic arm. An Erbium-doped Yttrium Aluminium Garnet (Er:YAG) laser and a piezoelectric (PZE) osteotome were used for comparison. In six grown up female Göttingen minipigs, comparative surgical interventions were done on the edentulous mandibular ridge. Our laser system was used to create different shapes of bone defects on the left side of the mandible. On the contralateral side, similar bone defects were created by PZE osteotome. Small bone samples were harvested to compare the immediate post-operative cut surface. The analysis of the cut surface of the laser osteotomy and conventional mechanical osteotomy revealed an essential difference. The scanning electron microscopy (SEM) analysis showed biologically open cut surfaces from the laser osteotomy. The samples from PZE osteotomy showed a flattened tissue structure over the cut surface, resembling the "smear layer" from tooth preparation. We concluded that our new finding with the mechanical osteotomy suggests a biological explanation to the expected difference in subsequent bone healing. Our hypothesis is that the difference of surface characteristic yields to different bleeding pattern and subsequently results in different bone healing. The analyses of bone healing will support our hypothesis. © 2015 Wiley Periodicals, Inc.

  12. Electro-spun organic nanofibers elaboration process investigations using comparative analytical solutions.

    Science.gov (United States)

    Colantoni, A; Boubaker, K

    2014-01-30

    In this paper Enhanced Variational Iteration Method, EVIM is proposed, along with the BPES, for solving Bratu equation which appears in the particular elecotrospun nanofibers fabrication process framework. Elecotrospun organic nanofibers, with diameters less than 1/4 microns have been used in non-wovens and filtration industries for a broad range of filtration applications in the last decade. Electro-spinning process has been associated to Bratu equation through thermo-electro-hydrodynamics balance equations. Analytical solutions have been proposed, discussed and compared.

  13. Simulation and comparative study of tunneling field effect transistors with dopant-segregated Schottky source/drain

    Science.gov (United States)

    Zhang, Yi Bo; Sun, Lei; Xu, Hao; Han, Jing Wen

    2016-04-01

    Dopant-segregated Schottky source/drain tunneling field effect transistors (STFET) are investigated in this paper. The working mechanisms of STFET and the influence of device parameters are studied with Synopsys Sentaurus. Schottky source/drain MOSFETs possess several advantages over conventional MOSFETs, and dopant segregation can be feasibly achieved within current silicidation process. With dopant segregation, highly doped regions can be obtained after silicidation, which is necessary for band-to-band tunneling. With proper parameter setting, STFET can achieve comparable performance as TFET. High segregation doping for STFET is required to increase band-to-band tunneling probability and suppress bipolar behaviors. Increasing the electron barrier height at source side helps to provide larger drive current and higher on/off ratio. It is also found that STFET’s on-state performance is irrelevant to the segregation length when the segregation length is larger than a certain value. Furthermore, STFET is also insensitive to the Schottky barrier at drain side when the Schottky barrier at source side is fixed, which would relax the requirement for source/drain fabrication.

  14. Investigation of oxidative stress and dietary habits in Mongolian people, compared to Japanese people

    Directory of Open Access Journals (Sweden)

    Chimedregzen Ulziiburen

    2006-06-01

    Full Text Available Abstract Background The average life span of Mongolians is 62 years for males and 69 years for females. This life span is about 16 years shorter than that of Japanese. Mongolian people generally eat meat, fat and diary products but less vegetables or fruit. Thus, we investigated the state of oxidative stress and dietary habits of Mongolians. Methods The investigation was performed in Murun city in the northwest area of Mongolia. A total of 164 healthy subjects (24–66 y were enrolled. As a marker of reactive oxygen species, the levels of reactive oxygen metabolites (ROM were measured using the d-ROM test. Interviews about dietary habits were performed using the Food Frequency Questionnaire established by the Kagawa Nutrition University. Results ROM levels were 429.7 ± 95.2 Carr U for Murun subjects, whereas Japanese people (n = 220, 21–98 y showed 335.3 ± 59.8 (p Conclusion Murun subjects may be in high oxidative stress, which may have a relationship with early ageing and several diseases, ultimately resulting in their short life span. In order to increase antioxidant capacity and suppress overproduction of ROM, antioxidant food intake is recommended.

  15. [Environmental investigation of ground water contamination at Wright- Patterson Air Force Base, Ohio]. Volume 4, Health and Safety Plan (HSP); Phase 1, Task 4 Field Investigation report: Draft

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    This Health and Safety Plan (HSP) was developed for the Environmental Investigation of Ground-water Contamination Investigation at Wright-Patterson Air Force Base near Dayton, Ohio, based on the projected scope of work for the Phase 1, Task 4 Field Investigation. The HSP describes hazards that may be encountered during the investigation, assesses the hazards, and indicates what type of personal protective equipment is to be used for each task performed. The HSP also addresses the medical monitoring program, decontamination procedures, air monitoring, training, site control, accident prevention, and emergency response.

  16. Comparing a current-carrying circular wire with polygons of equal perimeter: magnetic field versus magnetic flux

    Science.gov (United States)

    Silva, J. P.; Silvestre, A. J.

    2005-09-01

    We compare the magnetic field at the centre and the self-magnetic flux through a current-carrying circular loop, with those obtained for current-carrying polygons with the same perimeter. As the magnetic field diverges at the position of the wires, we compare the self-fluxes utilizing several regularization procedures. The calculation is best performed utilizing the vector potential, thus highlighting its usefulness in practical applications. Our analysis answers some of the intuition challenges students face when they encounter a related simple textbook example. These results can be applied directly to the determination of mutual inductances in a variety of situations.

  17. Structural Controls on Groundwater Flow in Basement Terrains: Geophysical, Remote Sensing, and Field Investigations in Sinai

    KAUST Repository

    Mohamed, Lamees

    2015-07-09

    An integrated [very low frequency (VLF) electromagnetic, magnetic, remote sensing, field, and geographic information system (GIS)] study was conducted over the basement complex in southern Sinai (Feiran watershed) for a better understanding of the structural controls on the groundwater flow. The increase in satellite-based radar backscattering values following a large precipitation event (34 mm on 17–18 January 2010) was used to identify water-bearing features, here interpreted as preferred pathways for surface water infiltration. Findings include: (1) spatial analysis in a GIS environment revealed that the distribution of the water-bearing features (conductive features) corresponds to that of fractures, faults, shear zones, dike swarms, and wadi networks; (2) using VLF (43 profiles), magnetic (7 profiles) techniques, and field observations, the majority (85 %) of the investigated conductive features were determined to be preferred pathways for groundwater flow; (3) northwest–southeast- to north–south-trending conductive features that intersect the groundwater flow (southeast to northwest) at low angles capture groundwater flow, whereas northeast–southwest to east–west features that intersect the flow at high angles impound groundwater upstream and could provide potential productive well locations; and (4) similar findings are observed in central Sinai: east–west-trending dextral shear zones (Themed and Sinai Hinge Belt) impede south to north groundwater flow as evidenced by the significant drop in hydraulic head (from 467 to 248 m above mean sea level) across shear zones and by reorientation of regional flow (south–north to southwest–northeast). The adopted integrated methodologies could be readily applied to similar highly fractured basement arid terrains elsewhere. © 2015 Springer Science+Business Media Dordrecht

  18. A comparative investigation on strain induced crystallization for graphene and carbon nanotubes filled natural rubber composites

    Directory of Open Access Journals (Sweden)

    D. H. Fu

    2015-07-01

    Full Text Available Natural rubber containing graphene and carbon nanotubes (CNTs composites were prepared by ultrasonicallyassisted latex mixing. Natural rubber filled by both graphene and CNTs show significant enhanced tensile strength, while graphene exhibits a better reinforcing effect than CNTs. Strain-induced crystallization in natural rubber composites during stretching was determined by synchrotron wide-angle X-ray diffraction. With the addition of CNTs or graphene, the crystallization for natural rubber occurs at a lower strain compared to unfilled natural rubber, and the strain amplification effects were observed. The incorporation of graphene results in a faster strain-induced crystallization rate and a higher crystallinity compared to CNTs. The entanglement-bound rubber tube model was used to analyze the chain network structure and determine the network parameters of composites. The results show that the addition of graphene or CNTs has an influence on the molecular network structure and improves the contribution of entanglement to the conformational constraint, while graphene has a more marked effect than CNTs.

  19. Investigation of the light signal's amplification of the gas scintillator working in the electric field

    Energy Technology Data Exchange (ETDEWEB)

    Gorski, A.; Karpik-Piaskowska, K.; Malecki, H.; Stepinski, M. (Lodz Univ. (Poland). Inst. Fizyki)

    1980-01-01

    The apparature for the investigation of the properties of the gas scintillator is described. The gas scintillator is working in the electric field. We got the characteristics of the amplification's changes of the light signal of krypton in the function of the electric field's intensity for different values of the pressure of the used gas.

  20. Second-order spatial correlation in the far-field: Comparing entangled and classical light sources

    Science.gov (United States)

    Zhang, Erfeng; Liu, Weitao; Lin, Huizu; Chen, Pingxing

    2016-02-01

    We consider second-order spatial correlation with entangled and classical light in the far-field. The quantum theory of second-order spatial correlation is analyzed, and the role of photon statistics and detection mode in the second-order spatial correlation are discussed. Meanwhile, the difference of second-order spatial correlation with entangled and classical light sources is deduced.

  1. Use of wavelets to compare simulated yield patterns for precision agriculture at the field scale

    NARCIS (Netherlands)

    Verhagen, A.; Stein, A.; Epinat, V.

    2000-01-01

    In this paper spatial patterns of simulated water limited potato production for a farm field in the Netherlands are analyzed using wavelets. The simulated yield patterns are decomposed using wavelets into crystals with a varying resolution. These crystals are used to relate the simulated spatial

  2. Comparative evaluation of genetic assays to identify oral pre-cancerous fields

    NARCIS (Netherlands)

    Bremmer, J.F.; Braakhuis, B.J.; Brink, A.; Broeckaert, M.A.; Beliën, J.A.M.; Meijer, G.A.; Kuik, D.J.; Leemans, C.R.; Bloemena, E.; van der Waal, I.; Brakenhoff, R.H.

    2008-01-01

    Background: Oral squamous cell carcinomas often develop in a pre-cancerous field, defined as mucosal epithelium with cancer-related genetic alterations, and which may appear as a clinically visible lesion. The test characteristics of three genetic assays that were developed to detect pre-cancerous f

  3. Zeolite force fields and experimental siliceous frameworks in a comparative infrared study

    NARCIS (Netherlands)

    Bueno-Perez, R.; Calero, S.; Dubbeldam, D.; Ania, C.O.; Parra, J.B.; Zaderenko, A.P.; Merkling, P.J.

    2012-01-01

    Infrared spectra (IR) of a great variety of zeolite frameworks in the limit of pure silica composition are calculated by molecular dynamics and also recorded experimentally. This enables us to study and assess the effect of three flexible force fields from the literature developed for zeolites in

  4. Compound specific isotope analysis to investigate pesticide degradation in lysimeter experiments at field conditions

    Science.gov (United States)

    Ryabenko, Evgenia; Elsner, Martin; Bakkour, Rani; Hofstetter, Thomas; Torrento, Clara; Hunkeler, Daniel

    2015-04-01

    The frequent detection of organic micropollutants such as pesticides, consumer care products or pharmaceuticals in water is an increasing concern for human and ecosystem health. Degradation analysis of these compounds can be challenging in complex systems due to the fact that metabolites are not always found and mass balances frequently cannot be closed. Many abiotic and biotic degradation pathways cause, however, distinct isotope fractionation, where light isotopes are transferred preferentially from the reactant to the product pool (normal isotope fractionation). Compound-specific isotope analysis (CSIA) of multiple elements is a particularly powerful method to evaluate organic micropollutant transformation, because it can even give pathway-specific isotope fractionation (1,2). Available CSIA field studies, however, have focused almost exclusively on volatile petroleum and chlorinated hydrocarbons, which are present in high concentrations in the environment and can be extracted easily from water for GC-IRMS analysis. In the case of micropollutants, such as pesticides, CSIA in more challenging since it needs to be conducted at lower concentrations and requires pre-concentration, purification and high chromatographic performance (3). In this study we used lysimeters experiments to analyze transformation of atrazine, acetochlor, metolachlor and chloridazone by studying associated isotope fractionation. The project combines a) analytical method development for CSIA, b) identification of pathways of micropollutant degradation and c) quantification of transformation processes under field condition. The pesticides were applied both, at the soil surface and below the top soil under field-relevant concentrations in May 2014. After typical irrigation of the lysimeters, seepage water was collected in 50L bottles and stored for further SPE and CSIA. Here we present the very first result of a) analytical method development, b) improvement of SPE methods for complex pesticide

  5. Investigating the magnetic field-dependent conductivity in magnetite thin films by modelling the magnetorefractive effect.

    Science.gov (United States)

    Kelley, Chris S; Naughton, James; Benson, Emma; Bradley, Ruth C; Lazarov, Vlado K; Thompson, Sarah M; Matthew, Jim A D

    2014-01-22

    A model of the magnetorefractive effect is developed for metallic oxides which allows the MRE to be used to study the magnetic dependence of their transport and phononic properties. This model is successfully applied to Fe3O4 and compared to experiments on a series of magnetite thin films of varying thickness (10, 18, 37, 64 and 110 nm) deposited on MgO(111) substrates. Reflection spectra were modelled as a function of film thickness, calculated from the Fresnel equations using an Fe3O4 dielectric function consisting of Drude, hopping, phononic and d-s transition conductivity processes. The reflectivity spectra of the different thickness films are reasonably reproduced by the model and reveal that the Fe3O4 18.5 μm phonon peak is shifted to a shorter wavelength in the thin films, approaching the bulk value for t > 110 nm. The MRE spectra are modelled by introducing a magnetic field dependence to the hopping and phononic terms, where previous models have considered the magnetic dependence to be on the Drude term only. In addition, the position of the Fe3O4 18.5 μm phonon peak was also found to shift in energy in the applied magnetic field by 0.05 μm. These results demonstrate the potential for using the MRE technique for probing the underlying magnetoelectronic properties of thin film oxides in a quick and non-destructive way.

  6. Comparative Investigation of Normal Modes and Molecular Dynamics of Hepatitis C NS5B Protein

    Science.gov (United States)

    Asafi, M. S.; Yildirim, A.; Tekpinar, M.

    2016-04-01

    Understanding dynamics of proteins has many practical implications in terms of finding a cure for many protein related diseases. Normal mode analysis and molecular dynamics methods are widely used physics-based computational methods for investigating dynamics of proteins. In this work, we studied dynamics of Hepatitis C NS5B protein with molecular dynamics and normal mode analysis. Principal components obtained from a 100 nanoseconds molecular dynamics simulation show good overlaps with normal modes calculated with a coarse-grained elastic network model. Coarse-grained normal mode analysis takes at least an order of magnitude shorter time. Encouraged by this good overlaps and short computation times, we analyzed further low frequency normal modes of Hepatitis C NS5B. Motion directions and average spatial fluctuations have been analyzed in detail. Finally, biological implications of these motions in drug design efforts against Hepatitis C infections have been elaborated.

  7. A comparative investigation of three PM-less MW power range wind generator topologies

    DEFF Research Database (Denmark)

    Bratiloveanu, Catalin-Rauti; Traian Cosmin Anghelus, Dumitru; Boldea, I.

    2012-01-01

    heteropolar-rotor (standard) synchronous generators, especially for direct drives (very low speed) and multibrid (with single stage transmission (5/1-8/1 ratio)), new topologies have to be investigated to reduce initial costs and weights for high enough efficiency and energy annual yield. The present paper......, with sensitivity design inquires, the claw pole synchronous generator topology for a multibrid wind generator of 3 MW ,75rpm generator for a 15 rpm wind turbine with above 94 % efficiency for unity power factor (diode rectified output) for around 10 tons of copper and iron core materials. Though the case studies...... refer to large wind generators the same topologies are believed worth considering for powers less than 1 MW and even less than 100 kW. Similar topologies may be applied to micro-hydro generators. The results are promising but further in depth modeling, design and control studies of such novel PM...

  8. Comparative investigation of working fluids for an organic Rankine cycle with geothermal water

    Directory of Open Access Journals (Sweden)

    Liu Yan-Na

    2015-06-01

    Full Text Available In this paper, the thermodynamic investigation on the use of geothermal water (130 °C as maximum for power generation through a basic Rankine has been presented together with obtained main results. Six typical organic working fluids (i.e., R245fa, R141b, R290, R600, R152a, and 134a were studied with modifying the input pressure and temperature to the turbine. The results show that there are no significant changes taking place in the efficiency for these working fluids with overheating the inlet fluid to the turbine, i.e., efficiency is a weak function of temperature. However, with the increasing of pressure ratio in the turbine, the efficiency rises more sharply. The technical viability is shown of implementing this type of process for recovering low temperature heat resource.

  9. Comparative analysis of the genomes of two field isolates of the rice blast fungus Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Minfeng Xue

    Full Text Available Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice worldwide. The fungal pathogen is notorious for its ability to overcome host resistance. To better understand its genetic variation in nature, we sequenced the genomes of two field isolates, Y34 and P131. In comparison with the previously sequenced laboratory strain 70-15, both field isolates had a similar genome size but slightly more genes. Sequences from the field isolates were used to improve genome assembly and gene prediction of 70-15. Although the overall genome structure is similar, a number of gene families that are likely involved in plant-fungal interactions are expanded in the field isolates. Genome-wide analysis on asynonymous to synonymous nucleotide substitution rates revealed that many infection-related genes underwent diversifying selection. The field isolates also have hundreds of isolate-specific genes and a number of isolate-specific gene duplication events. Functional characterization of randomly selected isolate-specific genes revealed that they play diverse roles, some of which affect virulence. Furthermore, each genome contains thousands of loci of transposon-like elements, but less than 30% of them are conserved among different isolates, suggesting active transposition events in M. oryzae. A total of approximately 200 genes were disrupted in these three strains by transposable elements. Interestingly, transposon-like elements tend to be associated with isolate-specific or duplicated sequences. Overall, our results indicate that gain or loss of unique genes, DNA duplication, gene family expansion, and frequent translocation of transposon-like elements are important factors in genome variation of the rice blast fungus.

  10. Comparative Investigation on Thermal Insulation of Polyurethane Composites Filled with Silica Aerogel and Hollow Silica Microsphere.

    Science.gov (United States)

    Liu, Chunyuan; Kim, Jin Seuk; Kwon, Younghwan

    2016-02-01

    This paper presents a comparative study on thermal conductivity of PU composites containing open-cell nano-porous silica aerogel and closed-cell hollow silica microsphere, respectively. The thermal conductivity of PU composites is measured at 30 degrees C with transient hot bridge method. The insertion of polymer in pores of silica aerogel creates mixed interfaces, increasing the thermal conductivity of resulting composites. The measured thermal conductivity of PU composites filled with hollow silica microspheres is estimated using theoretical models, and is in good agreement with Felske model. It appears that the thermal conductivity of composites decreases with increasing the volume fraction (phi) when hollow silica microsphere (eta = 0.916) is used.

  11. Advanced Investigation and Comparative Study of Graphics Processing Unit-queries Countered

    Directory of Open Access Journals (Sweden)

    A. Baskar

    2014-10-01

    Full Text Available GPU, Graphics Processing Unit, is the buzz word ruling the market these days. What is that and how has it gained that much importance is what to be answered in this research work. The study has been constructed with full attention paid towards answering the following question. What is a GPU? How is it different from a CPU? How good/bad it is computationally when comparing to CPU? Can GPU replace CPU, or it is a day dream? How significant is arrival of APU (Accelerated Processing Unit in market? What tools are needed to make GPU work? What are the improvement/focus areas for GPU to stand in the market? All the above questions are discussed and answered well in this study with relevant explanations.

  12. Suicide Rates in Greece: Comparing Mortality Data with Police Reporting Statistics and Investigating Recent Trends

    Directory of Open Access Journals (Sweden)

    Alexandra Tragaki

    2017-04-01

    Full Text Available This paper analyzes recent suicide trends in Greece. It relies on two separate databases, vital statistics and police records, the latter never having been explored before. Those datasets present a different picture about the suicide rates and trends, confirming the crucial importance of data reliability and consistency in time trend analysis. Frequencies and ratios were calculated and compared using paired sample t-tests. Overtime trend changes were detected applying segment regression analysis on both data collections. Our findings suggest that there are important differences between vital and police statistics on suicides. At national level, over the period 1990–2013, vital statistics reported an average of 7 percent more suicides, annually. Differences were more pronounced among women and younger ages. Both datasets confirm a change in total suicide trends during recent recession, but police data analysis supports that increases are less impressive than vital statistics claim.

  13. Comparative study of the efficacy of pulsed electromagnetic field and low level laser therapy on mitogen-activated protein kinases

    Directory of Open Access Journals (Sweden)

    Ayman M. El-Makakey

    2017-03-01

    Full Text Available Mitogen-Activated Protein Kinases (MAPKs consist of three major signaling members: extracellular signal-regulated kinase (ERK, p38 and C-JUN N-terminal kinase (JNK. We investigated physiological effects of Pulsed Electromagnetic Field Therapy (PEMFT and Low Level Laser Therapy (LLLT on human body, adopting the expression level of mitogen-activated protein kinases as an indicator via assessment of the activation levels of three major families of MAPKS, ERK, p38 and JNK in the peripheral lymphocytes of patients before and after the therapies. Assessment for the expression levels of MAPKs families' were done, in the peripheral lymphocytes of patients recently have appendectomy, using flow cytometric analysis of multiple signaling pathways, pre and post LLLT and PEMFT application (twice daily for 6 successive days on the appendectomy wound. There were non-significant differences in the expression levels of MAPKs families' pre- therapies application. But there were significant increase in the ERK expression levels post application of LLLT compared to its pre application (p<0.01. Also, there was significant increase in the ERK, p38 and C-Jun N terminal expression level values post application of PEMFT compared to its pre application expression levels (p<0.01 for each. The present study demonstrates that PEMFT has a powerful healing effect more than LLLT as it increase the activation of ERK, P38 and C-Jun-N Terminal while LLLT only increase the activation of ERK. LLLT has more potent pain decreasing effect than PEMFT as it does not activate P38 pathway like PEMFT.

  14. Investigation on Indoor Air Pollution and Childhood Allergies in Households in Six Chinese Cities by Subjective Survey and Field Measurements.

    Science.gov (United States)

    Hu, Jinhua; Li, Nianping; Lv, Yang; Liu, Jing; Xie, Jingchao; Zhang, Huibo

    2017-08-29

    Greater attention is currently being paid to the relationship between indoor environment and childhood allergies, however, the lack of reliable data and the disparity among different areas hinders reliable assessment of the relationship. This study focuses on the effect of indoor pollution on Chinese schoolchildren and the relationship between specific household and health problems suffered. The epidemiological questionnaire survey and the field measurement of the indoor thermal environment and primary air pollutants including CO₂, fine particulate matter (PM2.5), chemical pollutants and fungi were performed in six Chinese cities. A total of 912 questionnaires were eligible for statistical analyses and sixty houses with schoolchildren aged 9-12 were selected for field investigation. Compared with Chinese national standards, inappropriate indoor relative humidity (70%), CO₂ concentration exceeding 1000 ppm and high PM2.5 levels were found in some monitored houses. Di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) were the most frequently detected semi-volatile organic compounds (SVOCs) in house dust. Cladosporium, Aspergillus and Penicillium were detected in both indoor air and house dust. This study indicates that a thermal environment with CO₂ exceeding 1000 ppm, DEHP and DBP exceeding 1000 μg/g, and high level of PM2.5, Cladosporium, Aspergillus and Penicillium increases the risk of children's allergies.

  15. Investigations on Temperature Fields during Laser Beam Melting by Means of Process Monitoring and Multiscale Process Modelling

    Directory of Open Access Journals (Sweden)

    J. Schilp

    2014-07-01

    Full Text Available Process monitoring and modelling can contribute to fostering the industrial relevance of additive manufacturing. Process related temperature gradients and thermal inhomogeneities cause residual stresses, and distortions and influence the microstructure. Variations in wall thickness can cause heat accumulations. These occur predominantly in filigree part areas and can be detected by utilizing off-axis thermographic monitoring during the manufacturing process. In addition, numerical simulation models on the scale of whole parts can enable an analysis of temperature fields upstream to the build process. In a microscale domain, modelling of several exposed single hatches allows temperature investigations at a high spatial and temporal resolution. Within this paper, FEM-based micro- and macroscale modelling approaches as well as an experimental setup for thermographic monitoring are introduced. By discussing and comparing experimental data with simulation results in terms of temperature distributions both the potential of numerical approaches and the complexity of determining suitable computation time efficient process models are demonstrated. This paper contributes to the vision of adjusting the transient temperature field during manufacturing in order to improve the resulting part's quality by simulation based process design upstream to the build process and the inline process monitoring.

  16. An X-Ray Investigation of the NGC346 Field in the SMC (3): XMM-Newton Data

    Science.gov (United States)

    Naze, Yael; Manfroid, Jean; Corcoran, Michael F.; Stevens, Ian R.

    2004-01-01

    We present new XMM-Newton results on the field around the NGC346 star cluster in the SMC. This continues and extends previously published work on Chandra observations of the same field. The two XMM-Newton observations were obtained, respectively, six months before and six months after the previously published Chandra data. Of the 51 X-ray sources detected with XMM-Newton, 29 were already detected with Chandru. Comparing the properties of these X-ray sources in each of our three datasets has enabled us to investigate their variability on times scales of a year. Changes in the flux levels and/or spectral properties were observed for 21 of these sources. In addition, we discovered long-term variations in the X-ray properties of the peculiar system HD5980, a luminous blue variable star, that is likely to be a colliding wind binary system, which displays the largest luminosity during the first XMM-Newton observation.

  17. Investigation on Indoor Air Pollution and Childhood Allergies in Households in Six Chinese Cities by Subjective Survey and Field Measurements

    Directory of Open Access Journals (Sweden)

    Jinhua Hu

    2017-08-01

    Full Text Available Greater attention is currently being paid to the relationship between indoor environment and childhood allergies, however, the lack of reliable data and the disparity among different areas hinders reliable assessment of the relationship. This study focuses on the effect of indoor pollution on Chinese schoolchildren and the relationship between specific household and health problems suffered. The epidemiological questionnaire survey and the field measurement of the indoor thermal environment and primary air pollutants including CO2, fine particulate matter (PM2.5, chemical pollutants and fungi were performed in six Chinese cities. A total of 912 questionnaires were eligible for statistical analyses and sixty houses with schoolchildren aged 9–12 were selected for field investigation. Compared with Chinese national standards, inappropriate indoor relative humidity (<30% or >70%, CO2 concentration exceeding 1000 ppm and high PM2.5 levels were found in some monitored houses. Di(2-ethylhexyl phthalate (DEHP and dibutyl phthalate (DBP were the most frequently detected semi-volatile organic compounds (SVOCs in house dust. Cladosporium, Aspergillus and Penicillium were detected in both indoor air and house dust. This study indicates that a thermal environment with CO2 exceeding 1000 ppm, DEHP and DBP exceeding 1000 μg/g, and high level of PM2.5, Cladosporium, Aspergillus and Penicillium increases the risk of children’s allergies.

  18. An investigation on the magneto-optic properties of terbium gallium garnet under high magnetic field

    Institute of Scientific and Technical Information of China (English)

    Yang Guo; Zhang Guo-Ying; Gao Jiao; Xue Liu-Ping; Xia Tian; Zhang Xue-Long

    2011-01-01

    The superexchange interaction on a magnetic ion may be represented by an effective field Hm = λM in some paramagnetic materials, here λ is the coefficient of effective field and M = XHe with X being the magnetic susceptibility and He being the applied field. The variation of the equivalent λX with the dynamic applied field is given and the crystal field-splitting levels of the excited configuration 4f75d1 of the Tbs+ ion are calculated in the Tb3Ga5O12. By means of the effective field Hm and the applied field He, the Faraday rotation of Tb3Ga5O12 at 6 K and 41 K, under the high magnetic field and at 0.63μm wavelength, are presented. Our calculated results are in agreement with the experimental data.

  19. Investigation of protein folding by coarse-grained molecular dynamics with the UNRES force field.

    Science.gov (United States)

    Maisuradze, Gia G; Senet, Patrick; Czaplewski, Cezary; Liwo, Adam; Scheraga, Harold A

    2010-04-08

    Coarse-grained molecular dynamics simulations offer a dramatic extension of the time-scale of simulations compared to all-atom approaches. In this article, we describe the use of the physics-based united-residue (UNRES) force field, developed in our laboratory, in protein-structure simulations. We demonstrate that this force field offers about a 4000-times extension of the simulation time scale; this feature arises both from averaging out the fast-moving degrees of freedom and reduction of the cost of energy and force calculations compared to all-atom approaches with explicit solvent. With massively parallel computers, microsecond folding simulation times of proteins containing about 1000 residues can be obtained in days. A straightforward application of canonical UNRES/MD simulations, demonstrated with the example of the N-terminal part of the B-domain of staphylococcal protein A (PDB code: 1BDD, a three-alpha-helix bundle), discerns the folding mechanism and determines kinetic parameters by parallel simulations of several hundred or more trajectories. Use of generalized-ensemble techniques, of which the multiplexed replica exchange method proved to be the most effective, enables us to compute thermodynamics of folding and carry out fully physics-based prediction of protein structure, in which the predicted structure is determined as a mean over the most populated ensemble below the folding-transition temperature. By using principal component analysis of the UNRES folding trajectories of the formin-binding protein WW domain (PDB code: 1E0L; a three-stranded antiparallel beta-sheet) and 1BDD, we identified representative structures along the folding pathways and demonstrated that only a few (low-indexed) principal components can capture the main structural features of a protein-folding trajectory; the potentials of mean force calculated along these essential modes exhibit multiple minima, as opposed to those along the remaining modes that are unimodal. In addition

  20. A detailed investigation of facial expression processing in congenital prosopagnosia as compared to acquired prosopagnosia.

    Science.gov (United States)

    Humphreys, Kate; Avidan, Galia; Behrmann, Marlene

    2007-01-01

    Whether the ability to recognize facial expression can be preserved in the absence of the recognition of facial identity remains controversial. The current study reports the results of a detailed investigation of facial expression recognition in three congenital prosopagnosic (CP) participants, in comparison with two patients with acquired prosopagnosia (AP) and a large group of 30 neurologically normal participants, including individually age- and gender-matched controls. Participants completed a fine-grained expression recognition paradigm requiring a six-alternative forced-choice response to continua of morphs of six different basic facial expressions (e.g. happiness and surprise). Accuracy, sensitivity and reaction times were measured. The performance of all three CP individuals was indistinguishable from that of controls, even for the most subtle expressions. In contrast, both individuals with AP displayed pronounced difficulties with the majority of expressions. The results from the CP participants attest to the dissociability of the processing of facial identity and of facial expression. Whether this remarkably good expression recognition is achieved through normal, or compensatory, mechanisms remains to be determined. Either way, this normal level of performance does not extend to include facial identity.

  1. Investigating GABA and its function in platelets as compared to neurons.

    Science.gov (United States)

    Kaneez, Fatima Shad; Saeed, Sheikh Arshad

    2009-08-01

    We have recently suggested that platelets could be used as a model for neuronal receptors. In this paper we have investigated gamma-aminobutyric acid (GABA) metabolism and GABA receptors in platelets and in cultured neurons to see whether platelets' GABA mimics neuronal GABA receptor activities. We used the ELISA technique for detecting the GABA concentration in platelet rich plasma and cultured neurons. The functional effects of GABA and its receptor ligands on platelets were determined using an aggregometer. We found that the GABA concentration is 30% lower in platelets than in neurons and in both preparations GABA was metabolized by GABA transaminase (GABA-T). GABA potentiated calcium dependent platelet aggregation with a higher value in washed platelets suspension (WPS) then in platelet rich plasma (PRP). This effect was inhibited by benzodiazepines, calcium channel blockers and the selective phosphoinositide 3-kinase antagonist Wortmannin. GABA neurotransmission is involved in most aspects of normal brain function and can be perturbed in many neuropathologic conditions. We concluded that platelets could be further developed to be used as a peripheral model to study neuronal GABAergic function and its abnormality in diseases such as epilepsy and schizophrenia. Furthermore our results indicated that PI3-kinase is involved in calcium dependent GABA induced platelet aggregation as this synergistic effect is inhibited by Wortmannin in dose dependent manner.

  2. Investigating Learning Strategies for Vocabulary Development: A Comparative Study of Two Universities of Quetta, Pakistan

    Directory of Open Access Journals (Sweden)

    Irum Fatima

    2016-04-01

    Full Text Available The primary purpose of this research is to investigate the vocabulary learning strategies employed by the undergraduate students of Sardar Bahadur Khan Women’s University (SBKWU and University of Balochistan (UOB, Quetta, Pakistan. A quantitative design was employed in this study to answer the two research questions of the present study. The quantitative data was obtained from the responses of 180 undergraduates in a questionnaire adapted from the study by Noor and Amir (2009 on vocabulary learning strategies proposed by Gu and Johnson (1996. The questionnaire comprised of 45 close-ended items on four broad vocabulary learning strategies, metacognitive regulation strategy, cognitive strategy, memory strategy, and activation strategy. Descriptive statistics was run in SPSS to obtain the results. The independent-samples t-test was run to test for statistically significant differences if any in the use of vocabulary learning strategies across the undergraduates of two universities. However, cognitive regulation strategy, and activation strategy emerged as the most influential source of learning new English words. The findings also revealed that there were no statistically significant differences found in practicing vocabulary learning strategies between undergraduates of SBKWU and UOB. The findings of the study have implications on enhancing teaching and learning by acquainting students with vocabulary learning strategies that can enhance their vocabulary in English language and can result to boost up their proficiency in this language. Keywords: Vocabulary development, learning strategies, gender difference

  3. Comparing Herschel dust emission structures, magnetic fields observed by Planck, and dynamics: high-latitude star forming cloud L1642

    Science.gov (United States)

    Malinen, Johanna

    2016-01-01

    The nearby high-latitude cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. This cloud is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g., of the effect of magnetic fields. We compare Herschel dust emission structures and magnetic field orientation revealed by Planck polarization maps in L1642, and also combine these with dynamic information from molecular line observations. The high-resolution Herschel data reveal a complex structure including a dense, compressed central blob with elongated extensions, low density striations, "fishbone" like structures with a spine and perpendicular striations, and a spiraling "tail". The Planck polarization data reveal an ordered magnetic field that pervades the cloud and is aligned with the surrounding low density striations. We show that there is a complex interplay between the cloud structure and large scale magnetic fields revealed by Planck polarization data at 10' resolution. This suggests that the magnetic field is closely linked to the formation and evolution of the cloud. We see a clear transition from aligned to perpendicular structures approximately at a column density of NH = 2x10^21 cm-2. We conclude that Planck polarization data revealing the large scale magnetic field orientation can be very useful even when comparing to the finest structures in higher resolution data, e.g. Herschel at ~18" resolution.

  4. [Testing the comparability of free-field and HDA200 headphone measurements for the Freiburg speech test].

    Science.gov (United States)

    Thiele, C; Wardenga, N; Lenarz, T; Büchner, A

    2014-02-01

    In clinical practice, the standardized Freiburg speech test is presented via headphones as well as via loudspeakers. To achieve comparable results with both presentation modes, the headphone measurements are equated to the free-field situation. The free-field correction is determined by subjective loudness balance measurements and realized by a free-field equalizer network and a broadband frequency correction value during headphone calibration. Using the Freiburg speech test, this study tested the comparability of free-field and HDA200 headphone measurements. In 15 normal hearing subjects, the Freiburg speech intelligibility test was performed using both loudspeakers and HDA200 headphones. The 50% speech reception threshold measured using HDA200 headphones was on average 5.1 dB lower than for loudspeakers and lay below the standardized reference values. The desired comparability to free-field measurements could not be shown for the HDA200 headphones. The improved intelligibility via HDA200 is probably caused by the fact that the calibration correction factor of 4 dB is too high. This should be checked by the PTB.

  5. Mental imagery of positive and neutral memories: A fMRI study comparing field perspective imagery to observer perspective imagery.

    Science.gov (United States)

    Grol, Maud; Vingerhoets, Guy; De Raedt, Rudi

    2017-02-01

    Imagery perspective can influence what information is recalled, processing style, and emotionality; however, the understanding of possible mechanisms mediating these observed differences is still limited. We aimed to examine differences between memory recall from a field perspective and observer perspective at the neurobiological level, in order to improve our understanding of what is underlying the observed differences at the behavioral level. We conducted a fMRI study in healthy individuals, comparing imagery perspectives during recall of neutral and positive autobiographical memories. Behavioral results revealed field perspective imagery of positive memories, as compared to observer perspective, to be associated with more positive feelings afterwards. At the neurobiological level, contrasting observer perspective to field perspective imagery was associated with greater activity, or less decrease relative to the control visual search task, in the right precuneus and in the right temporoparietal junction (TPJ). Greater activity in the right TPJ during an observer perspective as compared to field perspective could reflect performing a greater shift of perspective and mental state during observer perspective imagery than field perspective imagery. Differential activity in the precuneus may reflect that during observer perspective imagery individuals are more likely to engage in (self-) evaluative processing and visuospatial processing. Our findings contribute to a growing understanding of how imagery perspective can influence the type of information that is recalled and the intensity of the emotional response. Observer perspective imagery may not automatically reduce emotional intensity but this could depend on how the imagined situation is evaluated in relation to the self-concept.

  6. Comparative CFD Investigation on the Performance of a New Family of Super-Cavitating Hydrofoils

    Science.gov (United States)

    Brizzolara, S.; Bonfiglio, L.

    2015-12-01

    We present a CFD characterization of a new type of super-cavitating hydrofoil section designed to have optimal performance both in super-cavitating conditions and in sub-cavitating conditions (including transitional regime). The basic concepts of the new profile family are first introduced. Lift, drag and cavity shapes at different cavitation numbers are calculated for a new foil and compared with those of conventional sub-cavitating and super-cavitating profiles. Numerical calculations confirm the superior characteristics of the new hydrofoil family, which is able to attain high lift and efficiency both in sub-cavitating and super-cavitating conditions. Numerical calculations are based on a multi-phase fully turbulent URANSE solver with a bubble dynamic cavitation model to follow the generation and evaporation of the vapor phase. The new profile family, initially devised for ultra-high speed hydrofoil crafts, may result useful for diverse applications such as super-cavitating or surface-piercing propellers or high-speed sailing boats.

  7. Improved performance of linear coal cutting compared with rotary cutting. Report of investigations/1995

    Energy Technology Data Exchange (ETDEWEB)

    Roepke, W.W.; Hanson, B.D.; Olson, R.C.; Wingquist, C.F.; Myren, T.A.

    1995-07-01

    The linear cutting system, developed by the U.S. Bureau of Mines, uses geometric principles developed by Cardan to produce a nearly constant cut depth. The new system has been extensively tested in a synthetic material under laboratory conditions to verify mechanical capability and to identify operational characteristics. Comparisons between 15-rpm linear cutting and 50-rpm rotary cutting systems show significant improvement in respirable dust entrainment, product size distribution, and energy usage. Respirable dust is reduced by as much as 90 pct. Recovered product showed a 67-pct reduction in -0.32-cm (-1/8-in) material and a 200-pct increase in +5.08 cm (+2 in) material. Average power was reduced by 66 pct for the linear cutting. Because the bit cutting paths differ between linear and rotary cutting, it was necessary to compare the two at the same cut depths and bit types. These comparisons show that low revolution per minute rotary cutting entrains about the same amount of respirable dust as the linear cutting system, but the average shaft torque may be 55 to 130 pct greater for the rotary system.

  8. Using assessments to investigate and compare the nature of learning in undergraduate science courses.

    Science.gov (United States)

    Momsen, Jennifer; Offerdahl, Erika; Kryjevskaia, Mila; Montplaisir, Lisa; Anderson, Elizabeth; Grosz, Nate

    2013-06-01

    Assessments and student expectations can drive learning: students selectively study and learn the content and skills they believe critical to passing an exam in a given subject. Evaluating the nature of assessments in undergraduate science education can, therefore, provide substantial insight into student learning. We characterized and compared the cognitive skills routinely assessed by introductory biology and calculus-based physics sequences, using the cognitive domain of Bloom's taxonomy of educational objectives. Our results indicate that both introductory sequences overwhelmingly assess lower-order cognitive skills (e.g., knowledge recall, algorithmic problem solving), but the distribution of items across cognitive skill levels differs between introductory biology and physics, which reflects and may even reinforce student perceptions typical of those courses: biology is memorization, and physics is solving problems. We also probed the relationship between level of difficulty of exam questions, as measured by student performance and cognitive skill level as measured by Bloom's taxonomy. Our analyses of both disciplines do not indicate the presence of a strong relationship. Thus, regardless of discipline, more cognitively demanding tasks do not necessarily equate to increased difficulty. We recognize the limitations associated with this approach; however, we believe this research underscores the utility of evaluating the nature of our assessments.

  9. Comparative investigation of the binding characteristics of poly-L-lysine and chitosan on alginate hydrogel.

    Science.gov (United States)

    Ren, Ying; Xie, Hongguo; Liu, Xiaocen; Bao, Jie; Yu, Weiting; Ma, Xiaojun

    2016-03-01

    The binding properties of poly-L-lysine and chitosan to alginate have been evaluated quantitatively and compared. Poly-L-lysine bound to alginate hydrogel more rapidly than chitosan as poly-L-lysine has a smaller molar hydrodynamic volume. In addition, poly-L-lysine showed a much higher binding capacity (6.14:1) for alginate hydrogel beads than chitosan (2.71:1), and a little higher binding stoichiometry (0.58) to sodium alginate molecules in solution than chitosan (0.49). An exothermic heat of alginate-poly-L-lysine complexes formation of 2.02 kJ/mol was detected. For alginate-chitosan complexes, the binding enthalpy has been seen to be -3.49 kJ/mol. The stability of the polyelectrolyte complexes was related to their binding enthalpy. The alginate-poly-L-lysine complexes could be disintegrated and rebuilt. By contrast, chitosan was bound with alginate in a steady state. These results provide fundamental insights regarding the structure and property relationships of macromolecules, and will be helpful in designing and selecting appropriate polymers.

  10. Comparative investigations of genotoxic activity of five nitriles in the comet assay and the Ames test.

    Science.gov (United States)

    Wu, Jong-C; Hseu, You C; Chen, Chin-H; Wang, Shu-H; Chen, Ssu C

    2009-09-30

    Two short-term assays, the modified Ames test and the comet assay, were carried out to evaluate the genotoxicity of five nitriles (acetonitrile, propionitrile, methacrylonitrile, butyronitrile, and benzonitrile). With the comet assay, all the nitriles studied were found to induce the genotoxicity in human lymphocytes and Hep G2 cells. Except for butyronitrile, the genotoxic potency in lymphocytes was more pronounced than that in Hep G2 cells, and the rank order of genotoxicity induced by these five nitriles in lymphocytes was different from that in Hep G2 cells, indicating that the pathways leading to genotoxicity in both types of cells were different. In the modified Ames test, no tested nitriles showed mutagenic activity on Salmonella typhimurium strain TA 98 and TA 100 with and without metabolic activation. Comparing the results obtained from both tests in this study, the comet assay seems to be more sensitive than the modified Ames test. Thus, the comet assay can be used to detect the genotoxicity of all nitriles.

  11. Levirate marriage amongst the Hebrews and widow's inheritance amongst the Yoruba: A comparative investigation

    Directory of Open Access Journals (Sweden)

    Samson O. Olanisebe

    2014-01-01

    Full Text Available In ancient Israel, even though widowhood was not something people were praying for, when it came, the people involved were protected by the legal and customary structures already in place. One of those structures in the Old Testament is the institution of the levirate marriage where the right and the possession due to a widow without a son for her late husband could be protected and appropriated. A similar custom was also found amongst the pre-colonial Yoruba people through the widow�s inheritance which guarantees the welfare of the widow after the demise of her husband. However, these structures have been dismantled by Christianity, thereby exposing the majority of present-day widows to untold hardship. This article, therefore, through historical, descriptive and comparative methods, examines the customs of the levirate marriage and widow�s inheritance in the two cultures, ascertains how effective they were in addressing the welfare and protection of the rights and privileges of widows and recommends how the church can better see to the welfare of the widows in the society.

  12. A Comparative Investigation of Confidence Intervals for IndependentVariables in Linear Regression.

    Science.gov (United States)

    Dudgeon, Paul

    2016-01-01

    In linear regression, the most appropriate standardized effect size for individual independent variables having an arbitrary metric remains open to debate, despite researchers typically reporting a standardized regression coefficient. Alternative standardized measures include the semipartial correlation, the improvement in the squared multiple correlation, and the squared partial correlation. No arguments based on either theoretical or statistical grounds for preferring one of these standardized measures have been mounted in the literature. Using a Monte Carlo simulation, the performance of interval estimators for these effect-size measures was compared in a 5-way factorial design. Formal statistical design methods assessed both the accuracy and robustness of the four interval estimators. The coverage probability of a large-sample confidence interval for the semipartial correlation coefficient derived from Aloe and Becker was highly accurate and robust in 98% of instances. It was better in small samples than the Yuan-Chan large-sample confidence interval for a standardized regression coefficient. It was also consistently better than both a bootstrap confidence interval for the improvement in the squared multiple correlation and a noncentral interval for the squared partial correlation.

  13. Comparative phytochemical investigation of the sources of ayurvedic drug Patha: A chromatographic fingerprinting analysis

    Directory of Open Access Journals (Sweden)

    Hullatti K

    2010-01-01

    Full Text Available Standardization of herbal drugs based on their chemical and biological activity profile is an important prerequisite for acquiring the herbal market. The main problem encountered in standardization of Ayurvedic drugs is proper identification of the source plant. The present study was aimed to establish identification characters, quality control parameters, chemical and biological parameters for roots of three plants Cissampelos pareira, Cyclea peltata and Stephania japonica (Fam. Menispermaceae which are being used as source of Patha, in the market. All the three plant were subjected for evaluation of quality control parameters as per WHO guidelines and root extracts and total alkaloidal fractions were subjected for HPTLC and HPLC fingerprinting analysis using a marker compound Bebeerine isolated from roots of Cissampelos pareira. The parameters studied clearly indicated the significant differences among the three plant materials. The roots of Cissampelos pareira can be distinguished from other two plants by presence of high concentration of alkaloids especially the presence of high concentration of pharmacologically active alkaloid bebeerine, which was found to be present in very low concentration in Stephania japonica and absent in roots of Cyclea peltata. The roots of Cyclea peltata were found to contain high concentration of saponins and comparatively in low concentration in Cissampelos pareira where as it was found to be absent in roots of Stephania japonica.

  14. The impact of floc size on respiration inhibition by soluble toxicants--a comparative investigation.

    Science.gov (United States)

    Henriques, Inês D S; Holbrook, R David; Kelly, Richard T; Love, Nancy G

    2005-07-01

    Activated sludge facilities are susceptible to upset by shock loads of toxic compounds. We hypothesized that floc size plays an important role in determining the sensitivity of mixed liquor to shock by cadmium and 2,4-dinitrophenol (DNP). To test this hypothesis, heterotrophic respiration inhibition experiments were conducted using mixed liquor from a pilot-scale membrane bioreactor (MBR) and full-scale activated sludge (FSAS) facility with gravity settling secondary clarifiers that were operated under similar process conditions. MBR mixed liquor flocs were both 41% smaller and 2 and 1.25 times more sensitive to equivalent soluble cadmium and DNP concentrations, respectively, compared to FSAS mixed liquor flocs. Similarly, FSAS mixed liquor that had been sheared (resulting in a smaller average floc diameter) was 1.5 times more sensitive to soluble cadmium than non-sheared FSAS mixed liquor. These results suggest that activated sludge process conditions that create smaller floc particles, such as the use of membranes for liquid-solid separation, are more susceptible to upset events caused by shock loads of cadmium and DNP. The particle size distribution (PSD) and average floc diameter of a mixed liquor suspension should be measured and reported when stating the inhibition concentration of a specific toxicant.

  15. A comparative investigation of methods for longitudinal data with limits of detection through a case study.

    Science.gov (United States)

    Fu, P; Hughes, J; Zeng, G; Hanook, S; Orem, J; Mwanda, O W; Remick, S C

    2016-02-01

    The statistical analysis of continuous longitudinal data may be complicated since quantitative levels of bioassay cannot always be determined. Values beyond the limits of detection (LOD) in the assays may not be observed and thus censored, rendering complexity to the analysis of such data. This article examines how both left-censoring and right censoring of HIV-1 plasma RNA measurements, collected for the study on AIDS-related Non-Hodgkin's lymphoma (AR-NHL) in East Africa, affects the quantification of viral load and explores the natural history of viral load measurements over time in AR-NHL patients receiving anticancer chemotherapy. Data analyses using Monte Carlo EM algorithm (MCEM) are compared to analyses where the LOD or LOD/2 (left censoring) value is substituted for the censored observations, and also to other methods such as multiple imputation, and maximum likelihood estimation for censored data (generalized Tobit regression). Simulations are used to explore the sensitivity of the results to changes in the model parameters. In conclusion, the antiretroviral treatment was associated with a significant decrease in viral load after controlling the effects of other covariates. A simulation study with finite sample size shows MCEM is the least biased method and the estimates are least sensitive to the censoring mechanism.

  16. Comparative numerical investigation of a wood residues indirectly fired gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ngoma, G. [Quebec Univ., Abitibi-Temiscaminque, PQ (Canada). Dept. of Applied Sciences

    2005-07-01

    Two models of an indirectly fired gas turbine that used both wood residues and natural gas combustors were presented. A Brayton cycle concept was used for the modelling calculations. The first model used wood residues burned in a combustor, where the resulting flue gases were used to preheat the air from a regenerator. In the second model, flue gases were used to preheat the air from the compressor. A computer program was developed from separate thermodynamic models of the compressor, regenerator, wood combustor, natural gas combustor, and gas turbine. The program was then used to calculate the mass and energy balances for each component. Irreversibilities within the compressor and the turbine were accounted for by using isentropic efficiencies. Numerical simulations were then performed to predict the static behaviour of the combustors. Results showed the effects of regenerator effectiveness, mass flow rate, compressor pressure ratio and gas turbine inlet temperature on the overall thermal efficiency. The results of both models were then compared. It was concluded that the model that preheated air from the compressor was more efficient than the model that preheated air from the regenerator. 6 refs., 11 figs.

  17. Comparing Manned Aerial Surveys to Unmanned Aerial Surveys for Cetacean Monitoring in the Arctic: Field Report

    Science.gov (United States)

    2015-01-01

    miles north of Barrow, Alaska. Portable Arctic Oven tents were used to shelter the GCS, the UAS, and the survey team. The tents, along with the...equipment inside a hard-sided structure. For instance, the Point Barrow DEW line site has lodging, kitchens and workspaces that might have been...A: Approved for public release. 28 In addition, ONR provided a portable weather station to the team, which was used late in the field project

  18. Comparing the Evolution of the Galaxy Disk Sizes with CDM Models The Hubble Deep Field

    CERN Document Server

    Giallongo, E; Poli, F; D'Odorico, S; Fontana, A

    2000-01-01

    The intrinsic sizes of the field galaxies with I-19) galaxies is skewed with respect to the CDM predictions and an excess of small-size disks (R_d<2 kpc) is already present at z~ 0.5. The excess persists up to z~3 and involves brighter galaxies . Such an excess may be reduced if luminosity-dependent effects, like starburst activity in interacting galaxies, are included in the physical mechanisms governing the star formation history in CDM models.

  19. Numerical investigation of flow field configuration and contact resistance for PEM fuel cell performance

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Mohammad Hadi; Rismanchi, Behzad [Department of Mechanical Engineering, Shiraz University, Shiraz 71348-51154 (Iran)

    2008-08-15

    A steady-state three-dimensional non-isothermal computational fluid dynamics (CFD) model of a proton exchange membrane fuel cell is presented. Conservation of mass, momentum, species, energy, and charge, as well as electrochemical kinetics are considered. In this model, the effect of interfacial contact resistance is also included. The numerical solution is based on a finite-volume method. In this study the effects of flow channel dimensions on the cell performance are investigated. Simulation results indicate that increasing the channel width will improve the limiting current density. However, it is observed that an optimum shoulder size of the flow channels exists for which the cell performance is the highest. Polarization curves are obtained for different operating conditions which, in general, compare favorably with the corresponding experimental data. Such a CFD model can be used as a tool in the development and optimization of PEM fuel cells. (author)

  20. Numerical investigations on electric field characteristics with respect to capacitive detection of free-flying droplets.

    Science.gov (United States)

    Ernst, Andreas; Mutschler, Klaus; Tanguy, Laurent; Paust, Nils; Zengerle, Roland; Koltay, Peter

    2012-01-01

    In this paper a multi-disciplinary simulation of a capacitive droplet sensor based on an open plate capacitor as transducing element is presented. The numerical simulations are based on the finite volume method (FVM), including calculations of an electric field which changes according to the presence of a liquid droplet. The volume of fluid (VOF) method is applied for the simulation of the ejection process of a liquid droplet out of a dispenser nozzle. The simulations were realised using the computational fluid dynamic (CFD) software CFD ACE+. The investigated capacitive sensing principle enables to determine the volume of a micro droplet passing the sensor capacitor due to the induced change in capacity. It could be found that single droplets in the considered volume range of 5 nL < V(drop) < 100 nL lead to a linear change of the capacity up to ΔQ < 30 fC. The sensitivity of the focused capacitor geometry was evaluated to be S(i) = 0.3 fC/nL. The simulation results are validated by experiments which exhibit good agreement.

  1. Atmospheric Radiation Measurement Madden-Julian Oscillation Investigation Experiment Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Long, Chuck [National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States). Earth System Research Lab.

    2016-07-01

    Every 30–90 days during the Northern Hemisphere winter, the equatorial tropical atmosphere experiences pulses of extraordinarily strong deep convection and rainfall. This phenomenon is referred to as the Madden–Julian Oscillation, or MJO, named after the scientists who identified this cycle. The MJO significantly affects weather and rainfall patterns around the world (Zhang 2013). To improve predictions of the MJO—especially about how it forms and evolves throughout its lifecycle—an international group of scientists collected an unprecedented set of observations from the Indian Ocean and western Pacific region from October 2011 through March 2012 through several coordinated efforts. The coordinated field campaigns captured six distinct MJO cycles in the Indian Ocean. The rich set of observations capturing several MJO events from these efforts will be used for many years to study the physics of the MJO. Here we highlight early research results using data from the Atmospheric Radiation Measurement (ARM) Madden-Julian Oscillation Investigation Experiment (AMIE), sponsored by the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility.

  2. The Application of Intensive Longitudinal Methods to Investigate Change: Stimulating the Field of Applied Family Research.

    Science.gov (United States)

    Bamberger, Katharine T

    2016-03-01

    The use of intensive longitudinal methods (ILM)-rapid in situ assessment at micro timescales-can be overlaid on RCTs and other study designs in applied family research. Particularly, when done as part of a multiple timescale design-in bursts over macro timescales-ILM can advance the study of the mechanisms and effects of family interventions and processes of family change. ILM confers measurement benefits in accurately assessing momentary and variable experiences and captures fine-grained dynamic pictures of time-ordered processes. Thus, ILM allows opportunities to investigate new research questions about intervention effects on within-subject (i.e., within-person, within-family) variability (i.e., dynamic constructs) and about the time-ordered change process that interventions induce in families and family members beginning with the first intervention session. This paper discusses the need and rationale for applying ILM to family intervention evaluation, new research questions that can be addressed with ILM, example research using ILM in the related fields of basic family research and the evaluation of individual-based interventions. Finally, the paper touches on practical challenges and considerations associated with ILM and points readers to resources for the application of ILM.

  3. Formation mechanism of gas bubble superlattice in UMo metal fuels: Phase-field modeling investigation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Shenyang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Senor, David J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Setyawan, Wahyu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Zhijie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-07-08

    Nano-gas bubble superlattices are often observed in irradiated UMo nuclear fuels. However, the for- mation mechanism of gas bubble superlattices is not well understood. A number of physical processes may affect the gas bubble nucleation and growth; hence, the morphology of gas bubble microstructures including size and spatial distributions. In this work, a phase-field model integrating a first-passage Monte Carlo method to investigate the formation mechanism of gas bubble superlattices was devel- oped. Six physical processes are taken into account in the model: 1) heterogeneous generation of gas atoms, vacancies, and interstitials informed from atomistic simulations; 2) one-dimensional (1-D) migration of interstitials; 3) irradiation-induced dissolution of gas atoms; 4) recombination between vacancies and interstitials; 5) elastic interaction; and 6) heterogeneous nucleation of gas bubbles. We found that the elastic interaction doesn’t cause the gas bubble alignment, and fast 1-D migration of interstitials along $\\langle$110$\\rangle$ directions in the body-centered cubic U matrix causes the gas bubble alignment along $\\langle$110$\\rangle$ directions. It implies that 1-D interstitial migration along [110] direction should be the primary mechanism of a fcc gas bubble superlattice which is observed in bcc UMo alloys. Simulations also show that fission rates, saturated gas concentration, and elastic interaction all affect the morphology of gas bubble microstructures.

  4. Passenger thermal comfort and behavior: a field investigation in commercial aircraft cabins.

    Science.gov (United States)

    Cui, W; Wu, T; Ouyang, Q; Zhu, Y

    2017-01-01

    Passengers' behavioral adjustments warrant greater attention in thermal comfort research in aircraft cabins. Thus, a field investigation on 10 commercial aircrafts was conducted. Environment measurements were made and a questionnaire survey was performed. In the questionnaire, passengers were asked to evaluate their thermal comfort and record their adjustments regarding the usage of blankets and ventilation nozzles. The results indicate that behavioral adjustments in the cabin and the use of blankets or nozzle adjustments were employed by 2/3 of the passengers. However, the thermal comfort evaluations by these passengers were not as good as the evaluations by passengers who did not perform any adjustments. Possible causes such as differences in metabolic rate, clothing insulation and radiation asymmetry are discussed. The individual difference seems to be the most probable contributor, suggesting possibly that passengers who made adjustments had a narrower acceptance threshold or a higher expectancy regarding the cabin environment. Local thermal comfort was closely related to the adjustments and significantly influenced overall thermal comfort. Frequent flying was associated with lower ratings for the cabin environment.

  5. A field study investigating effects of landmarks on territory size and shape.

    Science.gov (United States)

    Suriyampola, Piyumika S; Eason, Perri K

    2014-01-01

    Few studies have examined how landmarks affect territories' fundamental characteristics. In this field study, we investigated effects of landmarks on territory size, shape and location in a cichlid fish (Amatitlania siquia). We provided cans as breeding sites and used plastic plants as landmarks. During 10 min trials, we recorded locations where residents chased intruders and used those locations to outline and measure the territory. In two experiments, we observed pairs without landmarks and with either a point landmark (one plant) or linear landmark (four plants) placed near the nest can. We alternated which trial occurred first and performed the second trial 24 h after the first. Territories were approximately round without landmarks or with a point landmark but were significantly more elongated when we added a linear landmark. Without landmarks, nests were centrally located; however, with any landmark, pairs set territory boundaries closer to the landmark and thus the nest. Territory size was significantly reduced in the presence of any landmark. This reduction suggests that a smaller territory with well-defined boundaries has greater benefits than a larger territory with less well-defined borders.

  6. Numerical Investigations on Electric Field Characteristics with Respect to Capacitive Detection of Free-Flying Droplets

    Directory of Open Access Journals (Sweden)

    Peter Koltay

    2012-08-01

    Full Text Available In this paper a multi-disciplinary simulation of a capacitive droplet sensor based on an open plate capacitor as transducing element is presented. The numerical simulations are based on the finite volume method (FVM, including calculations of an electric field which changes according to the presence of a liquid droplet. The volume of fluid (VOF method is applied for the simulation of the ejection process of a liquid droplet out of a dispenser nozzle. The simulations were realised using the computational fluid dynamic (CFD software CFD ACE+. The investigated capacitive sensing principle enables to determine the volume of a micro droplet passing the sensor capacitor due to the induced change in capacity. It could be found that single droplets in the considered volume range of 5 nL < Vdrop < 100 nL lead to a linear change of the capacity up to ΔQ < 30 fC. The sensitivity of the focused capacitor geometry was evaluated to be Si = 0.3 fC/nL. The simulation results are validated by experiments which exhibit good agreement.

  7. Investigation of Improved Methods in Power Transfer Efficiency for Radiating Near-Field Wireless Power Transfer

    Directory of Open Access Journals (Sweden)

    Hesheng Cheng

    2016-01-01

    Full Text Available A metamaterial-inspired efficient electrically small antenna is proposed, firstly. And then several improving power transfer efficiency (PTE methods for wireless power transfer (WPT systems composed of the proposed antenna in the radiating near-field region are investigated. Method one is using a proposed antenna as a power retriever. This WPT system consisted of three proposed antennas: a transmitter, a receiver, and a retriever. The system is fed by only one power source. At a fixed distance from receiver to transmitter, the distance between the transmitter and the retriever is turned to maximize power transfer from the transmitter to the receiver. Method two is using two proposed antennas as transmitters and one antenna as receiver. The receiver is placed between the two transmitters. In this system, two power sources are used to feed the two transmitters, respectively. By adjusting the phase difference between the two feeding sources, the maximum PTE can be obtained at the optimal phase difference. Using the same configuration as method two, method three, where the maximum PTE can be increased by regulating the voltage (or power ratio of the two feeding sources, is proposed. In addition, we combine the proposed methods to construct another two schemes, which improve the PTE at different extent than classical WPT system.

  8. Field investigations of high stress soft surrounding rocks and deformation control

    Directory of Open Access Journals (Sweden)

    Weijian Yu

    2015-08-01

    Full Text Available Field investigations of high stress soft rock deformations show that the high stress soft rock roadway can slide with large deformation. Severe extrusion and floor heave can also be subsequently observed. The supported roadway can be locally damaged or completely fail, where the floor has a large deformation and/or is seriously damaged. The factors inducing large deformation of surrounding rocks in deep roadway are rock strengths, structure face cutting types, stress states, stress release, support patterns, and construction methods. Based on the deformation characteristics of high stress soft rock roadway, a comprehensive support scheme is proposed. The overall support technology of “step-by-step and joint, hierarchical reinforcement” for roadway is presented, and the anchor cable and bolt parameters to check the design methods are also given. Finally, the proposed comprehensive support method “bolt + metal mesh + U-steel arch + shortcrete + grouting and cable” is used in the extension section of east main haulage roadway at −850 m level of Qujiang coal mine. The 173-day monitoring results show that the average convergence of sidewalls reaches 208 mm, and the average relative convergence of roof and floor reaches 448 mm, suggesting that this kind of support technology for controlling large deformation of high stress soft surrounding rock roadway is effective.

  9. Formation mechanism of gas bubble superlattice in UMo metal fuels: Phase-field modeling investigation

    Science.gov (United States)

    Hu, Shenyang; Burkes, Douglas E.; Lavender, Curt A.; Senor, David J.; Setyawan, Wahyu; Xu, Zhijie

    2016-10-01

    Nano-gas bubble superlattices are often observed in irradiated UMo nuclear fuels. However, the formation mechanism of gas bubble superlattices is not well understood. A number of physical processes may affect the gas bubble nucleation and growth; hence, the morphology of gas bubble microstructures including size and spatial distributions. In this work, a phase-field model integrating a first-passage Monte Carlo method to investigate the formation mechanism of gas bubble superlattices was developed. Six physical processes are taken into account in the model: 1) heterogeneous generation of gas atoms, vacancies, and interstitials informed from atomistic simulations; 2) one-dimensional (1-D) migration of interstitials; 3) irradiation-induced dissolution of gas atoms; 4) recombination between vacancies and interstitials; 5) elastic interaction; and 6) heterogeneous nucleation of gas bubbles. We found that the elastic interaction doesn't cause the gas bubble alignment, and fast 1-D migration of interstitials along directions in the body-centered cubic U matrix causes the gas bubble alignment along directions. It implies that 1-D interstitial migration along [110] direction should be the primary mechanism of a fcc gas bubble superlattice which is observed in bcc UMo alloys. Simulations also show that fission rates, saturated gas concentration, and elastic interaction all affect the morphology of gas bubble microstructures.

  10. Comparative investigation of the calcification of the cryopreserved aortic and pulmonary homografts after implantation

    Institute of Scientific and Technical Information of China (English)

    YANG Guang; WANG Zeng-wei; CAI Zhen-jie; LI Ying; LIN Shu-xin

    2001-01-01

    This experiment was performed to investigate the calcification of the cryopreserved aortic and pulmonary homografts quantitively after implantation. Methods: In operation the heterotopic implantation of homograft conduits into the abdominal aorta was adopted. The calcification of the homograft conduits was determined by SX micro electronic probe analysis 8 wk after implantation. Results: Before implantation the calcium content of aortic homografts [(0.24±0.05) μg/mg] was significantly higher than that of pulmonary homograft [(0.13 ±0.02) μg/mg,P<0.01]. After implantation the calcium content ofarotic homografts [(0.53±0.09) μg/mg] was significantly higher than that before implantation [(0.24±0.05) μg/mg], with an increase by (123.4±53.0)% (P<0.01), and so was that of pulmonary homografts from [(0.13±0.02) to (0.21±0.30) μg/mg], with an increase by (63.8±35.8)%(P<0.01). And the calcium content of aortic homograft [(0.53±0.09) μg/mg] was still significantly higher than that of pulmonary homograft [(0.21±0.03) μg/mg, P<0.01 ]. Conclusion: In homograft conduit implantation the aortic homografts are more easily calcified than pulmonary homografts. The Micro electronic probe technique has a great significance in element component analysis of biological preparation.

  11. Interactions between Antibiotics and Graphene-Based Materials in Water: A Comparative Experimental and Theoretical Investigation.

    Science.gov (United States)

    Zhang, Xuntong; Shen, Jiachun; Zhuo, Ning; Tian, Ziqi; Xu, Peiran; Yang, Zhen; Yang, Weiben

    2016-09-14

    Complex interactions between antibiotics and graphene-based materials determine both the adsorption performance of graphene-based materials and the transport behaviors of antibiotics in water. In this work, such interactions were investigated through adsorption experiments, instrumental analyses and theoretical DFT calculations. Three typical antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) and tetracycline (TC)) and different graphene-based materials (divided into two groups: graphene oxides-based ones (GOs) and reduced GOs (RGOs)) were employed. Optimal adsorption pHs for NOR, SDZ, and TC are 6.2, 4.0, and 4.0, respectively. At corresponding optimal pHs, NOR favored RGOs (adsorption capability: ∼50 mg/g) while SDZ preferred GOs (∼17 mg/g); All adsorbents exhibited similar uptake of TC (∼70 mg/g). Similar amounts of edge carboxyls of both GOs and RGOs wielded electrostatic attraction with NOR and TC, but not with SDZ. According to DFT-calculated most-stable-conformations of antibiotics-adsorbents complexes, the intrinsic distinction between GOs and RGOs was the different amounts of sp(2) and sp(3) hybridization regions: π-π electron donor-acceptor effect of antibiotic-sp(2)/sp(3) and H-bonds of antibiotic-sp(3) coexisted. Binding energy (BE) of the former was larger for NOR; the latter interaction was stronger for SDZ; two species of TC at the optimal pH, i.e., TC(+) and TC(0), possessed larger BE with sp(3) and sp(2) regions, respectively.

  12. Investigation of the Influence of Magnetospheric Sources of Field-Aligned Currents on the Equatorial Electric Fields

    Science.gov (United States)

    Beloushko, Konstantin; Knyazeva, Mariya

    The urgency of studying electrodynamic processes related to the influence of spatial and temporal heterogeneities of the electromagnetic field in the Earth's upper atmosphere to the functioning of modern technological systems , satellite navigation systems , radio propagation Fundamentally new is the use of various third-party electrodynamic models in the total open loop model of the atmosphere based on the Upper Atmosphere Model (UAM) [1,2]. Performing calculations on model UAM using different spatial and temporal distributions of field-aligned currents and brands Lukianova and Papitashvili. A comparison of model results with data Jicamarca Incoherent Scatter Radar (Peru). References begin{enumerate} Namgaladze A.A., Korenkov Yu.N., Klimenko V.V., Karpov I.V., Bessarab F.S., Surotkin V.A., Gluschenko T.A., Naumova N.M. Global model of the thermosphere-ionosphere-protonosphere system. Pure and Applied Geophysics. № 2/3, 127, 219-254, 1988. Namgaladze A.A., Martynenko O.V., Namgaladze A.N. Global model of the upper atmosphere with variable latitudinal steps of numerical integration, IUGG XXI General Assembly, Boulder, 1995, Abstracts, GAB41F-6, B150, 1995, and (in Russian) Geamagn. Aeron., 36, 89-95, 1996a.

  13. Ultrafine needle CO{sub 2} splenoportography: A comparative investigation with transarterial portography and MR portography

    Energy Technology Data Exchange (ETDEWEB)

    Teng Gaojun [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China)]. E-mail: gjteng@vip.sina.com; Deng Gang [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Liu Zhensheng [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Fang Wen [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Zhu Guangyu [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Li Guozhao [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Guo Jinhe [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); He Shicheng [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China); Dong Yonghua [Department of Radiology, Zhong-Da Hospital, Southeast University, 87 Dingjiaqiao Road, Nanjing 210009 (China)

    2006-09-15

    Purpose: To evaluate the safety and quality of CO{sub 2} splenoportography (CO{sub 2}-SP) by comparison to 3-dimensional dynamic contrast-enhanced magnetic resonance portography (3D-DCE-MRP) and transarterial portography (TAP). Materials and methods: CO{sub 2}-SP, 3D-DCE-MRP and TAP were performed within 3 days in 35 patients. CO{sub 2}-SP was conducted with a 26 G needle by puncture of spleen under fluoroscopy and/or ultrasound guidance. A fifty mm{sup 3} of CO{sub 2} was manually injected within 3 s. The safety and the side effects of CO{sub 2}-SP were assessed with a scoring system based on both the subjective feeling of patients questioned and the objective appearances of vital signs, electrocardiogram (ECG) and saturation of percutaneous blood oxygen (SpO{sub 2}). The quality of the imaging was compared among the three groups using different methods by a scoring criterion based on visualization of the portal branches. Results: Transient mild discomfortable reaction was present in 18 patients (51.4%). The scores measured for quality of portal vein branch visualization in the groups with CO{sub 2}-SP, 3D-DCE-MRP and TAP were 226, 196 and 167, respectively (P < 0.001, the higher of the scores, the better of the quality). The visibility of collateral veins was not significantly different amongst the three imaging techniques. Conclusion: Ultrafine needle CO{sub 2}-SP is safe and minimally invasive. The quality of CO{sub 2}-SP is better than that with 3D-DCE-MRP and TAP in terms of the visualizing portal vein branches.

  14. Field investigation of arsenic in ceramic pot filter-treated drinking water.

    Science.gov (United States)

    Archer, A R; Elmore, A C; Bell, E; Rozycki, C

    2011-01-01

    Ceramic pot filters (CPFs) is one of several household water treatment technologies that is used to treat drinking water in developing areas. The filters have the advantage of being able to be manufactured using primarily locally available materials and local labor. However, naturally-occurring arsenic present in the clay used to make the filters has the potential to contaminate the water in excess of the World Health Organization drinking water standard of 0.01 mg/L. A manufacturing facility in Guatemala routinely rinses filters to reduce arsenic concentrations prior to distribution to consumers. A systemic study was performed to evaluate the change in arsenic concentrations with increasing volumes of rinse water. Arsenic field kit results were compared to standard method laboratory results, and dissolved versus suspended arsenic concentrations in CPF-treated water were evaluated. The results of the study suggest that rinsing is an effective means of mitigating arsenic leached from the filters, and that even in the absence of a formal rinsing program, routine consumer use may result in the rapid decline of arsenic concentrations. More importantly, the results indicate that filter manufacturers should give strong consideration to implementing an arsenic testing program.

  15. Computational investigation of porous media phase field formulations: Microscopic, effective macroscopic, and Langevin equations

    Science.gov (United States)

    Ververis, Antonios; Schmuck, Markus

    2017-09-01

    We consider upscaled/homogenized Cahn-Hilliard/Ginzburg-Landau phase field equations as mesoscopic formulations for interfacial dynamics in strongly heterogeneous domains such as porous media. A recently derived effective macroscopic formulation, which takes systematically the pore geometry into account, is computationally validated. To this end, we compare numerical solutions obtained by fully resolving the microscopic pore-scale with solutions of the upscaled/homogenized porous media formulation. The theoretically derived convergence rate O (ɛ 1 / 4) is confirmed for circular pore-walls. An even better convergence of O (ɛ1) holds for square shaped pore-walls. We also compute the homogenization error over time for different pore geometries. We find that the quality of the time evolution shows a complex interplay between pore geometry and heterogeneity. Finally, we study the coarsening of interfaces in porous media with computations of the homogenized equation and the microscopic formulation fully resolving the pore space. We recover the experimentally validated and theoretically rigorously derived coarsening rate of O (t 1 / 3) in the periodic porous media setting. In the case of critical quenching and after adding thermal noise to the microscopic porous media formulation, we observe that the influence of thermal fluctuations on the coarsening rate shows after a short, expected phase of universal coarsening, a sharp transition towards a different regime.

  16. Interdependency between Risk Assessments for Self and Other in the Field of Comparative Optimism: The Contribution of Response Times

    Science.gov (United States)

    Spitzenstetter, Florence; Schimchowitsch, Sarah

    2012-01-01

    By introducing a response-time measure in the field of comparative optimism, this study was designed to explore how people estimate risk to self and others depending on the evaluation order (self/other or other/self). Our results show the interdependency between self and other answers. Indeed, while response time for risk assessment for the self…

  17. Investigating physical field effects on the size-dependent dynamic behavior of inhomogeneous nanoscale plates

    Science.gov (United States)

    Ebrahimi, Farzad; Reza Barati, Mohammad

    2017-02-01

    This article investigates the thermo-mechanical vibration frequencies of magneto-electro-thermo-elastic functionally graded (METE-FG) nanoplates in the framework of refined four-unknown shear deformation plate theory. The present nanoplate is subjected to various kinds of thermal loads with uniform, linear and nonlinear distributions. The nonlinear distribution is considered as heat conduction and sinusoidal temperature rise. The present refined theory captures the influences of shear deformations without the need for shear correction factors. Thermo-magneto-electro-elastic coefficients of the FG nanoplate vary gradually along the thickness according to the power-law form. The scale coefficient is taken into consideration implementing the nonlocal elasticity of Eringen. The governing equations are derived through Hamilton's principle and are solved analytically. The frequency response is compared with those of previously published data. The obtained results are presented for the thermo-mechanical vibrations of the FG nanobeams to investigate the effects of material graduation, nonlocal parameter, mode number, slenderness ratio and thermal loading in detail. The present study is associated to aerospace, mechanical and nuclear engineering structures which are under thermal loads.

  18. Colloid-Facilitated Transport of Low-Solubility Radionuclides: A Field, Experimental, and Modeling Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, A B; Reimus, P W; Abdel-Fattah, A; Allen, P G; Anghel, I; Benedict, F C; Esser, B K; Lu, N; Kung, K S; Nelson, J; Neu, M P; Reilly, S D; Smith, D K; Sylwester, E R; Wang, L; Ware, S D; Warren, RG; Williams, R W; Zavarin, M; Zhao, P

    2003-02-01

    rate of Pu transport. Currently, the role of colloids in facilitating the transport of low-solubility radionuclides is not understood well enough to effectively model contaminant transport. A fundamental understanding of the role that colloids may or may not play in the transport of low-solubility radionuclides is needed in order to predict contaminant transport, design remediation strategies and provide risk assessments. Ryan and Elimelech (1996) have argued that in order to evaluate the potential for colloids to transport radionuclides, several criteria must be met: (1) colloids must exist and be stable, (2) radionuclides must have a high sorption affinity for the colloids, and (3) colloids must be transported. Only then can we understand the conditions where colloids can and will facilitate transport of radionuclides. In this report we compile the results from a series of field, laboratory and modeling studies funded by the UGTA program in order to evaluate the potential for colloids to transport low-solubility radionuclides at the NTS. The studies presented in this report fall under three general areas of investigation: Characterization of natural colloids in groundwater at NTS, Pu sorption/desorption experiments on colloid minerals identified in NTS groundwater, and Transport of Pu-doped colloids through fractured rock core. Chapter 1 is a background review of our current understanding of colloids and their role in facilitating contaminant transport. Chapters 2, and 3 are field studies that focused on characterizing natural colloids at different hydrologic environments at the NTS and address Ryan and Elimelech's (1996) first criteria regarding the existence and stability of colloids. Chapters 4, 5 and 6 are laboratory experimental studies that investigate the sorption/desorption behavior of Pu and other low-solubility radionuclides on colloid minerals observed in NTS groundwater. These studies evaluate Ryan and Elimelech's (1996) second criteria that the

  19. SIGNAL : Water vapour flux variability and local wind field investigations within five differently managed agroforestry sites across Germany

    Science.gov (United States)

    Markwitz, Christian; Siebicke, Lukas; Knohl, Alexander

    2016-04-01

    Optimising soil water uptake and ground water consumption in mono-specific agricultural systems plays an important role for sustainable land management. By including tree alleys into the agricultural landscape, called agroforestry (AF), the wind flow is modified leading to a presumably favourable microclimate behind the tree alleys. We expect that this zone is characterized by increased air temperature and atmospheric water vapour content, compared to mono-specific fields. This would extend the growing season and increase the yield production behind the tree alleys. Within the SIGNAL (Sustainable Intensification of Agriculture through Agroforestry) project the evapotranspiration (ET) variability and the local wind field of agroforestry sites compared to mono-specific agricultural systems is investigated. Our study is based on the comparison of five differently managed agroforestry sites across Germany. All site feature one agroforestry plot and one reference plot, which represents a mono-specific cropped system. Each plot is equipped with an eddy-covariance tower, including a high frequency 3D SONIC anemometer and instruments gathering standard meteorological parameter as pressure, temperature, relative humidity, precipitation, ground heat flux, net- and global radiation. The Surface Energy Budget (SEB) method will be used to calculate evapotranspiration QE as QE = - QN - QH - QG - Res by measuring the sensible heat flux, QH, with the eddy covariance method, the radiation balance, QN and the ground heat flux, QG. QH and QN will be measured continuously long-term. We will quantify site specific energy balance non-closure, Res, by temporarily measuring QE, using eddy covariance and a roving tower and then solving the SEB equation for Res. The short term Res will be used to then continuously derive QE from the SEB method. We will compare measured evapotranspiration rates from the SEB method to modelled evapotranspiration of the agroforestry systems through upscaling

  20. Comparing the solar magnetic field in the corona and in the inner heliosphere during solar cycles 21-23

    Science.gov (United States)

    Virtanen, I. I.; Mursula, K.

    2009-04-01

    We compare the open solar magnetic field estimated by the PFSS model based on the WSO photospheric field observations, with the inner heliospheric magnetic field. We trace the observed radial HMF into the coronal PFSS boundary at 2.5 solar radii using the observed solar wind velocity, and determine the PFSS model field at the line-of-sight footpoint. Comparing the two field values, we calculate the power n of the apparent decrease of the radial field. According to expectations based on Maxwell's equations, also reproduced by Parker's HMF model, the radial HMF field should decrease with n=2. However, comparison gives considerably lower values of n, indicating the effect of HCS in the PFSS model and the possible superexpansion. The n values vary with solar cycle, being roughly 1.3-1.4 at minima and about 1.7 at maxima. Interestingly, the n values for the two HMF sectors show systematic differences in the late declining to minimum phase, with smaller n values for the HMF sector dominant in the northern hemisphere. This is in agreement with the smaller field value in the northern hemisphere and the southward shifted HCS, summarized by the concept of the bashful ballerina. We also find that the values of n during the recent years, in the late declining phase of solar cycle 23, are significantly larger than during the same phase of the previous cycles. This agrees with the exceptionally large tilt of the solar dipole at the end of cycle 23. We also find that the bashful ballerina appears even during SC 23 but the related hemispheric differences are smaller than during the previous cycles.

  1. Comparative DNA profiling, phytochemical investigation, and biological evaluation of two Ficus species growing in Egypt

    Directory of Open Access Journals (Sweden)

    El-Sayeda A El-Kashoury

    2013-01-01

    Full Text Available Aim and Background: A comparison between two Ficus species, cultivated in Egypt, was carried out in this study. Their DNA analysis revealed that they are not closely related. Materials and Methods: The pharmacopoeial constants of the leaves showed higher total ash and acid insoluble ash in F. lyrata than in F. platypoda. The other parameters were close in both species. Preliminary phytochemical screening revealed the presence of carbohydrate and/or glycosides, tannins, flavonoids, sterols, and triterpenes in their leaves and was detected in traces in their stems. Results: Saponification of n-hexane extract of the leaves yielded 46% and 74.8% for the unsaponifiable matters and 20% and 15% for the fatty acids for F. platypoda and F. lyrata, respectively. n-Docosane (21.69% and n-heptacosane (33.77% were the major hydrocarbons in F. platypoda and F. lyrata, respectively. b-Sitosterol was the main sterol, palmitic (22.07% and carboceric (35.72% acids were the major identified saturated fatty acids in both species, while linoleic acid was the main unsaturated fatty acid (18.66% and 16.7% in both species, respectively. The acute toxicity study revealed that the two species were safe up to 2 g/kg. The antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH assay and pyrogallol as the standard was more significant for F. platypoda (232.6 μg/ml than for F. lyrata, (790.9 μg/ml. The oral antihyperglycemic activity in diabetic rats using alloxan revealed that the 80% ethanolic extract of the leaves of F. platypoda was more active than that of the leaves of F. lyrata in decreasing the blood glucose level at 200 mg/kg/day (107.9 ± 5.817, 127.2 ± 4.359 and 400 mg/kg/day (64.11 ± 4.358, 127.7 ± 6.889, respectively, when compared with the diabetic control gliclazide (172.3 ± 2.089. Conclusion: The results of this study provide evidence that the two Ficus species have antioxidant and antihyperglycemic activity, in the order F. platypoda and then F

  2. Neutron diffraction investigations of zero-field and field-induced magnetic structures of DyNiSn single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Murogaki, K. [Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)]. E-mail: murogaki@fiberbit.net; Kawano, S. [Research Reactor Institute, Kyoto University, Osaka 590-0494 (Japan); Andoh, Y. [Faculty of Regional Sciences, Tottori University, Tottori 680-8551 (Japan); Takahashi, M. [Institute of Materials Science, University of Tsukuba, Ibaraki 305-8573 (Japan); Kurisu, M. [Japan Advanced Institute of Science and Technology, Ishikawa 923-1292 (Japan); Nakamoto, G. [Japan Advanced Institute of Science and Technology, Ishikawa 923-1292 (Japan); Anh, D.T. Kim [Japan Advanced Institute of Science and Technology, Ishikawa 923-1292 (Japan); Tsutaoka, T. [Graduate School of Education, Hiroshima University, Hiroshima 739-8524 (Japan)

    2006-02-09

    Single crystal neutron diffraction studies have been performed on the rare-earth ternary compound, DyNiSn. This crystal exhibits an incommensurate magnetic structure expressed by the propagation vector, Q = (0.662 0.352 0) with its third harmonics at low temperatures. In an external magnetic field applied along the c-axis DyNiSn shows incommensurate modulation with Q = (1 0.315 0) at 1.6 K, while along the easy magnetization direction of the b-axis a commensurate modulation with Q = (2/3 0 0) develops at 2 K. The results along the b-axis are fully consistent with the magnetization curve.

  3. Geotechnical Field and Laboratory Investigation Procedures Pertinent to the Development of Commercial On-Shore Wind Farms in Ireland

    Directory of Open Access Journals (Sweden)

    Michael E. Quille

    2014-10-01

    Full Text Available In the last decade, both the Irish landscape and construction industry has seen a dramatic increase in the number of commercial on-shore wind farm developments. Geotechnicalfield and laboratory based testing procedures play a critical role in the development, design and construction of wind farms. A comprehensive knowledge of the ground conditionsand soil parameters prevailing across the development footprint are necessary to facilitate a site specific infrastructure and turbine foundation design; therefore, reducing associated construction risks and ensuring that an economic construction programme can be premeditated. This paper presents some geotechnical field and laboratory basedprocedures pertinent to both the development and design of commercial on-shore wind farms in Ireland. The various procedures are compared in terms of suitability of the testprocedure for the soil type encountered and geotechnical design soil parameters derived. Although each geotechnical site investigation scheme is both an iterative and uniqueprocess, a phased approach relating to a rough peat moor land typically encountered across wind farm sites in Ireland is presented.Keywords: Renewable Energy, Geotechnical, Site Investigation.

  4. INVESTIGATION OF DISSOLVED SULPHATE IN VARIOUS GEOTHERMAL FIELDS OF SUMATRA USING OXYGEN AND SULPHUR ISOTOPES

    Directory of Open Access Journals (Sweden)

    E. Ristin Pujiindiyati

    2010-06-01

    Full Text Available There are at least 30 high temperature systems; eleven active volcanoes, five degassing volcanoes and one caldera volcano controlled by Sumatra Fault Zone over a length of 1700 km. To understand this geothermal field system, some information about geochemistry including isotope composition in its fluid is needed. Sulphur-34 and oxygen-18 isotopes in dissolved sulphate pair have been used to determine the origin of acidic fluid of sulphate and to evaluate the process involved. The fluids from eight hot springs, two fumaroles, four deep wells and crater have been collected in along Sumatra geothermal fields. Sulphur-34 (d 34S (SO4, 0/00 CDT and oxygen-18 (d 18O (SO4, 0/00 SMOW in sulphate is analyzed according to Robinson-Kusakabe and Rafter method, respectively. The d 34S (SO4 values from Sibayak wells are more enriched of 16.8 0/00 to 18.2 0/0 that may indicate the dissolution of anhydrite minerals or isotope partitioning in hydration of SO2. The d 34S (SO4 values from two fumaroles (Pusuk Bukit - North Sumatra and Rantau Dadap - South Sumatra are at depleted value of -0.150/00 and 1.80/00, those are close to d 34S from magmatic sulphur.  In general, the d 34S (SO4 of springs spread in a wide range of 5.250/00 to14.20/00 and show a mixing process between atmospheric sulphate and sulphate from deep wells. The d 18O (SO4 from wells exhibits depleted value around -3.60/00 suggesting that 87.5% of sulphate oxygen is derived from groundwater oxygen and 12.5% is derived from atmospheric molecular oxygen in sulphide oxidation reaction. In the other hand, hot springs (except Semurup, crater and fumaroles have enriched value of d 18O (SO4. These enriched values suggest that a higher percentage of atmospherically derived oxygen compared to those from the depth.   Keywords: isotope, geothermal, Sumatra

  5. Investigation of the Three-Dimensional Structure of a Rotating Magnetic Field Driven Field-Reversed Configuration using Internal Magnetic Field Measurements

    Science.gov (United States)

    Velas, Katherine M.

    The Translation, Confinement, Sustainment Upgrade device (TCSU) used a rotating magnetic field (RMF) to form and sustain plasma in a field-reversed configuration (FRC). The physics of RMF current drive can be modeled in terms of the torque acting on the FRC. A fully translatable three-axis internal magnetic probe was built and used to generate a full r-z map of the magnetic field in the FRC and open field line region. Probe measurements are used to calculate the torques acting on the FRC formed using even-parity and odd-parity RMF antenna configurations. Odd-parity current drive was found to be more efficient and yields a plasma with lower resistivity than in even-parity current drive. An extrapolation method was developed to generate 3D magnetic field line plots which show that unlike in even-parity, field lines in odd-parity sustained FRCs make multiple transits of the FRC. Analysis using the three-axis probe data has greatly expanded our understanding of the physics of RMF driven FRCs.

  6. An Evaluation of the Use of Student-Centred Investigations in Teaching Comparative Animal Physiology to Undergraduates.

    Science.gov (United States)

    Spicer, John I.; Bonsall, Marie

    1995-01-01

    Taught comparative animal physiology to undergraduates (n=31) using student-centered (open-ended) investigations in small groups. Questionnaires and discussion found that students appeared to value learning through their own experience as highly as they did being taught and valued the opportunity to establish and develop skills less easily…

  7. Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these

  8. Experimental investigation of the visual field dependency in the erect and supine positions

    Science.gov (United States)

    Lichtenstein, J. H.; Saucer, R. T.

    1972-01-01

    The increasing utilization of simulators in many fields, in addition to aeronautics and space, requires the efficient use of these devices. It seemed that personnel highly influenced by the visual scene would make desirable subjects, particularly for those simulators without sufficient motion cues. In order to evaluate this concept, some measure of the degree of influence of the visual field on the subject in necessary. As part of this undertaking, 37 male and female subjects, including eight test pilots, were tested for their visual field dependency or independency. A version of Witkin's rod and frame apparatus was used for the tests. The results showed that nearly all the test subjects exhibited some degree of field dependency, the degree varying from very high field dependency to nearly zero field dependency in a normal distribution. The results for the test pilots were scattered throughout a range similar to the results for the bulk of male subjects. The few female subjects exhibited a higher field dependency than the male subjects. The male subjects exhibited a greater field dependency in the supine position than in the erect position, whereas the field dependency of the female subjects changed only slightly.

  9. Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method is a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these

  10. Mathematical field models of brushless DC motors with permanent magnets and their comparative analysis

    Directory of Open Access Journals (Sweden)

    A.V. Matyuschenko

    2015-03-01

    Full Text Available By means of JMAG-Designer 12 the author performed a comparative analysis of the calculation of the EMF, cogging torque and electromagnetic torque of brushless motor with permanent magnets in two-dimensional and three-dimensional formulation of the problem.

  11. Field Investigation on the Prevalence of Avian Influenza Virus Infection in Some Localities in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abdullah N. Alkhalaf

    2010-07-01

    Full Text Available The objective of this study was to find out prevalence and types of avian influenza virus (AIV among broilers, native chickens, ducks and pigeons in Saudi Arabia. Field investigation was carried out in four localities including Al-Qassim, Hail, Al-Jouf and Northern Border regions. Serum sample, tracheal and cloacal swabs were collected from broilers (n=1561, layers (n=988, ducks (n=329 and pigeons (n=450 from these localities and tested for three different avian influenza viruses (H9, H5 and H3 using Enzyme linked immunosorbent (ELISA test, hamagglutination inhibition (HI test and polymerase chain reaction (PCR. All tested samples were negative for H5 and H3 viruses. In contrast, all positive results were found to be for H9 AI virus using PCR, ELISA and HI test. Chicken sera tested by ELISA for AIV revealed the highest positive samples in Northern Border regions (45.71%, followed by Al-Jouf (29.65%, Al-Qassim (23.98% and Hial (20.94% with non-significant difference (χ2=5.983; P=0.112. HI test carried out on duck sera revealed 35.90% prevalence of antibodies against AIV. PCR amplification resulted in 34.28 and 21.36% positive samples in ducks and chickens, respectively. The highest (45.71% PCR positive chicken samples were from Northern Border regions, followed by Al-Jouf (24.13%, Al-Qassim (19.30% and Hail (16.69% with significant difference (χ2=7.620; P=0.055. All tested pigeons samples were negative for the three virus serotypes included in the study.

  12. Field investigation on consumer behavior and hydraulic performance of a district heating system in Tianjin, China

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Baoping; Fu, Lin; Di, Hongfa [Department of Building Science, Tsinghua University, Beijing 100084 (China)

    2009-02-15

    With the implementation of heat reforms in China, the application of thermostatic radiator valves (TRVs) has been gaining popularity in the new-style district heating systems (DHSs). The objective of this study was to investigate consumer behavior (including regulation of TRVs and opening of windows) and its influences on the hydraulic performance and energy consumption of individuals and the whole system. The concurrence rate of individual behaviors and hydraulic interactions between individuals were analyzed. This study should be helpful to gain a comprehensive understanding of the new DHSs in China and consider a proper design/control strategy for these systems. Questionnaires and field observations of consumer behavior, tests of hydraulic performance, and surveys of energy consumption were carried out in a DHS in Tianjin, which was one of the heat metering and billing demonstration projects in China. The main results of the tests were as follows: water flow performance in apartment-level heating systems were diverse because consumers' behavior was varied and unpredictable, and the hydraulic interaction between consumers living along the line of a vertical pipe was obvious, and was stronger for terminal consumers with their TRVs set to higher values; however, flow variations in the whole DHS, which included 910 households, were relatively constant. A probability analysis was carried out to explain this phenomenon, and the conclusion was drawn that when there were more than 200 consumers, the stochastic consumer regulation behavior would bring less than 10% of total flow variations. Finally, the power consumption of the circulation pump, heat consumption and energy-saving potential of this type of DHS were discussed and some suggestions for TRV regulation and pump operation were made. (author)

  13. Investigating the host galaxies of luminous AGN in the local universe with integral field spectroscopy

    Science.gov (United States)

    McElroy, Rebecca; Croom, Scott; Husemann, Bernd; Close AGN Reference Survey; SAMI Galaxy Survey

    2017-01-01

    This thesis investigates how galaxies and their super massive black holes coevolve. We use integral field spectroscopy to search for evidence of AGN feedback and triggering. We demonstrate that outflows are ubiquitous among luminous local type 2 AGN using observations from the AAT's SPIRAL instrument. Using multiple component Gaussian emission line decomposition we are able to disentangle the kinematic and ionisation properties of these winds. This allows us to argue that the outflows from these AGN are directly impacting the surrounding ISM within the galaxies. We search for evidence of AGN triggering using data from The Close AGN Reference Survey (CARS). CARS aims to provide a detailed multi-wavelength view of 40 nearby (0.01 type not once, but twice. So called ‘changing look’ AGN are an uncommon phenomenon, but twice changed AGN are much rarer. This AGN first transitioned from a narrow line AGN (type 2) to a broad line AGN (type 1) in the 1980s. It was recently observed as part of CARS. Examination of the MUSE data for this particular source showed that it no longer had the spectral features typical of a type 1 AGN. The continuum emission from the accretion disk was no longer visible and the broad lines were dramatically diminished. In this talk we describe the possible reasons for this change, supported by analysis of multi-epoch optical photometry and spectroscopy, alongside data obtained through director’s discretionary time from Chandra, HST, and the VLA. We then conclude by discussing the implications of this discovery on our understanding of AGN timescales and the physics behind AGN spectral types.

  14. Flow field investigation in rotating rib-roughened channel by means of particle image velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Coletti, Filippo [Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); Stanford University, Mechanical Engineering Department, Stanford, CA (United States); Maurer, Thomas [Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); Stuttgart University, Institute of Aerospace Thermodynamics, Stuttgart (Germany); Arts, Tony [Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); Di Sante, Alberto [Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); General Electric, Florence (Italy)

    2012-04-15

    The turbulent velocity field over the rib-roughened wall of an orthogonally rotating channel is investigated by means of two-dimensional particle image velocimetry (PIV). The flow direction is outward, with a bulk Reynolds number of 1.5 x 10{sup 4} and a rotation number ranging from 0.3 to 0.38. The measurements are obtained along the wall-normal/streamwise plane at mid-span. The PIV system rotates with the channel, allowing to measure directly the relative flow velocity with high spatial resolution. Coriolis forces affect the stability of the boundary layer and free shear layer. Due to the different levels of shear layer entrainment, the reattachment point is moved downstream (upstream) under stabilizing (destabilizing) rotation, with respect to the stationary case. Further increase in rotation number pushes further the reattachment point in stabilizing rotation, but does not change the recirculation length in destabilizing rotation. Turbulent activity is inhibited along the leading wall, both in the boundary layer and in the separated shear layer; the opposite is true along the trailing wall. Coriolis forces affect indirectly the production of turbulent kinetic energy via the Reynolds shear stresses and the mean shear. Two-point correlation is used to characterize the coherent motion of the separated shear layer. Destabilizing rotation is found to promote large-scale coherent motions and accordingly leads to larger integral length scales; on the other hand, the spanwise vortices created in the separating shear layer downstream of the rib are less organized and tend to be disrupted by the three-dimensional turbulence promoted by the rotation. The latter observation is consistent with the distributions of span-wise vortices detected in instantaneous flow realizations. (orig.)

  15. Investigation of electron-atom/molecule scattering resonances: Two complex multiconfigurational self-consistent field approaches

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, Kousik [Department of Chemistry, Rice University, Houston, TX 77005 (United States); Yeager, Danny L. [Department of Chemistry, Texas A and M University, College Station, TX 77843 (United States)

    2015-01-22

    Resonances are temporarily bound states which lie in the continuum part of the Hamiltonian. If the electronic coordinates of the Hamiltonian are scaled (“dilated”) by a complex parameter, η = αe{sup iθ} (α, θ real), then its complex eigenvalues represent the scattering states (resonant and non-resonant) while the eigenvalues corresponding to the bound states and the ionization and the excitation thresholds remain real and unmodified. These make the study of these transient species amenable to the bound state methods. We developed a quadratically convergent multiconfigurational self-consistent field method (MCSCF), a well-established bound-state technique, combined with a dilated Hamiltonian to investigate resonances. This is made possible by the adoption of a second quantization algebra suitable for a set of “complex conjugate biorthonormal” spin orbitals and a modified step-length constraining algorithm to control the walk on the complex energy hypersurface while searching for the stationary point using a multidimensional Newton-Raphson scheme. We present our computational results for the {sup 2}PBe{sup −} shape resonances using two different computationally efficient methods that utilize complex scaled MCSCF (i.e., CMCSCF). These two methods are to straightforwardly use CMCSCF energy differences and to obtain energy differences using an approximation to the complex multiconfigurational electron propagator. It is found that, differing from previous computational studies by others, there are actually two {sup 2}PBe{sup −} shape resonances very close in energy. In addition, N{sub 2} resonances are examined using one of these methods.

  16. Fast and Simple Detection of Yersinia pestis Applicable to Field Investigation of Plague Foci

    Science.gov (United States)

    Simon, Stéphanie; Demeure, Christian; Lamourette, Patricia; Filali, Sofia; Plaisance, Marc; Créminon, Christophe; Volland, Hervé; Carniel, Elisabeth

    2013-01-01

    Yersinia pestis, the plague bacillus, has a rodent-flea-rodent life cycle but can also persist in the environment for various periods of time. There is now a convenient and effective test (F1-dipstick) for the rapid identification of Y. pestis from human patient or rodent samples, but this test cannot be applied to environmental or flea materials because the F1 capsule is mostly produced at 37°C. The plasminogen activator (PLA), a key virulence factor encoded by a Y. pestis-specific plasmid, is synthesized both at 20°C and 37°C, making it a good candidate antigen for environmental detection of Y. pestis by immunological methods. A recombinant PLA protein from Y. pestis synthesized by an Escherichia coli strain was used to produce monoclonal antibodies (mAbs). PLA-specific mAbs devoid of cross-reactions with other homologous proteins were further cloned. A pair of mAbs was selected based on its specificity, sensitivity, comprehensiveness, and ability to react with Y. pestis strains grown at different temperatures. These antibodies were used to develop a highly sensitive one-step PLA-enzyme immunoassay (PLA-EIA) and an immunostrip (PLA-dipstick), usable as a rapid test under field conditions. These two PLA-immunometric tests could be valuable, in addition to the F1-disptick, to confirm human plague diagnosis in non-endemic areas (WHO standard case definition). They have the supplementary advantage of allowing a rapid and easy detection of Y. pestis in environmental and flea samples, and would therefore be of great value for surveillance and epidemiological investigations of plague foci. Finally, they will be able to detect natural or genetically engineered F1-negative Y. pestis strains in human patients and environmental samples. PMID:23383008

  17. Big Data in the SHELA Field: Investigating Galaxy Quenching at High Redshifts

    Science.gov (United States)

    Stevans, Matthew L.; Finkelstein, Steven L.; Wold, Isak; Kawinwanichakij, Lalitwadee; Sherman, Sydney; Gebhardt, Karl; Jogee, Shardha; Papovich, Casey J.; Ciardullo, Robin; Gronwall, Caryl; Gawiser, Eric J.; Acquaviva, Viviana; Casey, Caitlin; Florez, Jonathan; HETDEX Team

    2017-06-01

    We present a measurement of the z ~ 4 Lyman break galaxy (LBG) rest-frame UV luminosity function to investigate the onset of quenching in the early universe. The bright-end of the galaxy luminosity function typically shows an exponential decline far steeper than that of the underlying halo mass function. This is typically attributed to negative feedback from past active galactic nuclei (AGN) activity as well as dust attenuation. Constraining the abundance of bright galaxies at early times (z > 3) can provide a key insight into the mechanisms regulating star formation in galaxies. However, existing studies suffer from low number statistics and/or the inability to robustly remove stellar and AGN contaminants. In this study we take advantage of the unprecedentedly large (24 deg^2) Spitzer/HETDEX Exploratory Large Area (SHELA) field and its deep multi-wavelength photometry, which includes DECam ugriz, NEWFIRM K-band, Spitzer/IRAC, Herschel/SPIRE, and X-ray from XMM-Newton and Chandra. With SHELA’s deep imaging over a large area we are uniquely positioned to study statistically significant samples of massive galaxies at high redshifts (z > 3) when the first massive galaxies began quenching. We select our sample using photometric redshifts from the EAZY software package (Brammer et al. 2008) based on the optical and far-infrared imaging. We directly identify and remove stellar contaminants and AGN with IRAC colors and X-ray detections, respectively. By pinning down the exact shape of the bright-end of the z ~ 4 LBG luminosity function, we provide the deepest probe yet into the baryonic physics dominating star formation and quenching in the early universe.

  18. Fast and simple detection of Yersinia pestis applicable to field investigation of plague foci.

    Directory of Open Access Journals (Sweden)

    Stéphanie Simon

    Full Text Available Yersinia pestis, the plague bacillus, has a rodent-flea-rodent life cycle but can also persist in the environment for various periods of time. There is now a convenient and effective test (F1-dipstick for the rapid identification of Y. pestis from human patient or rodent samples, but this test cannot be applied to environmental or flea materials because the F1 capsule is mostly produced at 37°C. The plasminogen activator (PLA, a key virulence factor encoded by a Y. pestis-specific plasmid, is synthesized both at 20°C and 37°C, making it a good candidate antigen for environmental detection of Y. pestis by immunological methods. A recombinant PLA protein from Y. pestis synthesized by an Escherichia coli strain was used to produce monoclonal antibodies (mAbs. PLA-specific mAbs devoid of cross-reactions with other homologous proteins were further cloned. A pair of mAbs was selected based on its specificity, sensitivity, comprehensiveness, and ability to react with Y. pestis strains grown at different temperatures. These antibodies were used to develop a highly sensitive one-step PLA-enzyme immunoassay (PLA-EIA and an immunostrip (PLA-dipstick, usable as a rapid test under field conditions. These two PLA-immunometric tests could be valuable, in addition to the F1-disptick, to confirm human plague diagnosis in non-endemic areas (WHO standard case definition. They have the supplementary advantage of allowing a rapid and easy detection of Y. pestis in environmental and flea samples, and would therefore be of great value for surveillance and epidemiological investigations of plague foci. Finally, they will be able to detect natural or genetically engineered F1-negative Y. pestis strains in human patients and environmental samples.

  19. Plant-soil feedbacks: a comparative study on the relative importance of soil feedbacks in the greenhouse versus the field.

    Science.gov (United States)

    Heinze, Johannes; Sitte, M; Schindhelm, A; Wright, J; Joshi, J

    2016-06-01

    Interactions between plants and soil microorganisms influence individual plant performance and thus plant-community composition. Most studies on such plant-soil feedbacks (PSFs) have been performed under controlled greenhouse conditions, whereas no study has directly compared PSFs under greenhouse and natural field conditions. We grew three grass species that differ in local abundance in grassland communities simultaneously in the greenhouse and field on field-collected soils either previously conditioned by these species or by the general grassland community. As soils in grasslands are typically conditioned by mixes of species through the patchy and heterogeneous plant species' distributions, we additionally compared the effects of species-specific versus non-specific species conditioning on PSFs in natural and greenhouse conditions. In almost all comparisons PSFs differed between the greenhouse and field. In the greenhouse, plant growth in species-specific and non-specific soils resulted in similar effects with neutral PSFs for the most abundant species and positive PSFs for the less abundant species. In contrast, in the field all grass species tested performed best in non-specific plots, whereas species-specific PSFs were neutral for the most abundant and varied for the less abundant species. This indicates a general beneficial effect of plant diversity on PSFs in the field. Controlled greenhouse conditions might provide valuable insights on the nominal effects of soils on plants. However, the PSFs observed in greenhouse conditions may not be the determining drivers in natural plant communities where their effects may be overwhelmed by the diversity of abiotic and biotic above- and belowground interactions in the field.

  20. A COMPARATIVE STUDY ON THE EFFECTS OF THE POLYMER PROSTHETIC BASE PRESSURE OVER THE PROSTHETIC FIELD

    Directory of Open Access Journals (Sweden)

    A.T. Cigu

    2016-04-01

    Full Text Available Partially mobile polymeric prostheses constitute absolutely necessary therapeutical means in all forms of partial edentations. As known, polymeric partial prostheses constitute temporary solutions for the treatment of edentaton states. Nowadays, this treatment includes traditional acrylic prostheses, as well as elastic prostheses made of different material systems. Such a system is Valplast, which uses a polyamide for the realization of the prosthetic base. Both the rigid and the elastic materials are nowadays under debate, different – positive or negative – opinions being uttered in relation with their utilization. The scope of the present study is to support the intensive application of the elastic materials. Extremely important is the identification of the intrinsic qualities of the materials influencing the behaviour in the oral cavity, especially the effects of pressure upon the biological structures of the prosthetic field.

  1. An Investigation of Emitters Clogging Under Magnetic Field and Water Quality

    Directory of Open Access Journals (Sweden)

    A. Kiani

    2016-02-01

    Full Text Available Introduction: Water scarcity is one of the major problems for crop production. Using drip irrigation as an effective method in the efficient use of water is expanding in arid and semi-arid regions. One of the problems in under pressure irrigation during use of saline, unconventional and waste is emitters clogging. There are several ways to prevent particle deposits in pipes and clogging of emitters. Generally, conventional methods are divided into two categories: physical and chemical methods. In physical method, suspended solids and inorganic materials are removed using particles sediment sand and disc filters. In the chemical method the pH drops by adding acid to water resulting in the dissolution of carbonate sediments. With chlorine handling, organisms (i.e. algae, fungi and bacteria that are the main causes of biological clogging are destroyed. However, the application of these methods is not successful in all cases. It has been observed that the emitters have gradually become obstructed. Magnetic water is obtained by passing water through permanent magnets or through the electromagnets installed in or on a feed pipeline. When a fluid passes through the magnetized field, its structure and some physical characteristic such as density, salt solution capacity, and deposition ratio of solid particles will be changed. An experimental study showed that a relatively weak magnetic influence increases the viscosity of water and consequently causes stronger hydrogen bonds under the magnetic field.There exist very few documented research projects related to the magnetization of water technology and its application to agricultural issues in general and emitter clogging in drip irrigation method, in particular. This technology is already used in some countries, especially in the Persian Gulf states. This research was designed and implemented aimed at increasing knowledge about the application of magnetic technology and its effects on emitters clogging

  2. Working with MRI: An investigation of occupational exposure to strong static magnetic fields and associated symptoms

    NARCIS (Netherlands)

    Schaap, K.

    2015-01-01

    Magnetic resonance imaging (MRI) makes use of electromagnetic fields in the non-ionizing radiation frequency ranges. One of them is a continuously present strong static magnetic field (SMF), which extends up to several meters around the scanner. Each time an MRI worker performs tasks near the scanne

  3. Magnetic fields as an investigation technique and manipulation tool for phthalocyanine molecular aggregates

    NARCIS (Netherlands)

    Boamfa, M.I.; Christianen, P.C.M.; Engelkamp, H.; Nolte, R.J.M.; Maan, J.C.

    2004-01-01

    A polarized absorption spectroscopy (PAS) study of molecular aggregate solutions of phthalocyanine molecules in high magnetic fields is presented. We show that a magnetic field can induce macroscopic ordering of molecular aggregates (MAs), in a clean, non-contact method, which is well suited for MA

  4. Experimental investigation of axial plasma injection into a magnetic dipole field

    DEFF Research Database (Denmark)

    Jensen, Vagn Orla

    1968-01-01

    A high-density helium plasma, accelerated from a conical pinch, is injected axially into a magnetic dipole field. Magnetic probe measurements show that, near the axis, a compression of the field is super-imposed on the standard diamagnetic depression. The compression starts downstream and moves...

  5. Migration from PVC cling films compared with their field of application

    DEFF Research Database (Denmark)

    Petersen, Jens Højslev; Lillemark, L.; Lund, L.

    1997-01-01

    . Results of the migration testing were compared with the recommended and/or actual use of the PVC film and the labelling discussed in relation to the relevant EEC directives on food contact plastics. The correct labelling of plasticized PVC film intended for use in retail packaging is important to avoid......Samples of PVC cling films were taken at importers, wholesalers and retail shops, and their overall migration to the alternative food simulant iso-octane was measured, after establishment of a correlation between overall migration to olive oil at 40 degrees C in 10 days and to iso-octane in 2 h...... the risk of significant consumer intakes of the plasticizer di-(2-ethylhexyl) adipate (DEHA) after the film has been used in contact with fatty foodstuffs. Sixty percent of the films declared for use in contact with fatty foods showed too high overall migration compared with the current interpretation...

  6. A comparative study of P450 gene expression in field and laboratory Musca domestica L. strains

    DEFF Research Database (Denmark)

    Højland, Dorte Heidi; Vagn Jensen, Karl-Martin; Kristensen, Michael

    2014-01-01

    BACKGROUND The housefly is a global pest that has developed resistance to most insecticides applied for its control. Resistance has been associated with cytochrome P450 monooxygenases (P450s). The authors compare the expression of six genes possibly associated with insecticide resistance in three...... in the multiresistant strain (P metabolic resistance. There is a strong indication...... that CYP6G4 is a major insecticide resistance gene involved in neonicotinoid resistance. © 2013 Society of Chemical Industry...

  7. Comparative epigenomics: an emerging field with breakthrough potential to understand evolution of epigenetic regulation

    Directory of Open Access Journals (Sweden)

    Janine E. Deakin

    2014-12-01

    Full Text Available Epigenetic mechanisms regulate gene expression, thereby mediating the interaction between environment, genotype and phenotype. Changes to epigenetic regulation of genes may be heritable, permitting rapid adaptation of a species to environmental cues. However, most of the current understanding of epigenetic gene regulation has been gained from studies of mice and humans, with only a limited understanding of the conservation of epigenetic mechanisms across divergent taxa. The relative ease at which genome sequence data is now obtained and the advancements made in epigenomics techniques for non-model species provides a basis for carrying out comparative epigenomic studies across a wider range of species, making it possible to start unraveling the evolution of epigenetic mechanisms. We review the current knowledge of epigenetic mechanisms obtained from studying model organisms, give an example of how comparative epigenomics using non-model species is helping to trace the evolutionary history of X chromosome inactivation in mammals and explore the opportunities to study comparative epigenomics in biological systems displaying adaptation between species, such as the immune system and sex determination.

  8. A comparative study of penalization and phase field methods for the solution of the diffusion equation in complex geometries

    Science.gov (United States)

    Tauriello, Gerardo; Koumoutsakos, Petros

    2015-02-01

    We present a comparative study of penalization and phase field methods for the solution of the diffusion equation in complex geometries embedded using simple Cartesian meshes. The two methods have been widely employed to solve partial differential equations in complex and moving geometries for applications ranging from solid and fluid mechanics to biology and geophysics. Their popularity is largely due to their discretization on Cartesian meshes thus avoiding the need to create body-fitted grids. At the same time, there are questions regarding their accuracy and it appears that the use of each one is confined by disciplinary boundaries. Here, we compare penalization and phase field methods to handle problems with Neumann and Robin boundary conditions. We discuss extensions for Dirichlet boundary conditions and in turn compare with methods that have been explicitly designed to handle Dirichlet boundary conditions. The accuracy of all methods is analyzed using one and two dimensional benchmark problems such as the flow induced by an oscillating wall and by a cylinder performing rotary oscillations. This comparative study provides information to decide which methods to consider for a given application and their incorporation in broader computational frameworks. We demonstrate that phase field methods are more accurate than penalization methods on problems with Neumann boundary conditions and we present an error analysis explaining this result.

  9. The DYNAMO Orbiter Project: High Resolution Mapping of Gravity/Magnetic Fields and In Situ Investigation of Mars Atmospheric Escape

    Science.gov (United States)

    Smrekar, S.; Chassefiere, E.; Forget, F.; Reme, H.; Mazelle, C.; Blelly, P. -L.; Acuna, M.; Connerney, J.; Purucker, M.; Lin, R.

    2000-01-01

    Dynamo is a small Mars orbiter planned to be launched in 2005 or 2007, in the frame of the NASA/CNES Mars exploration program. It is aimed at improving gravity and magnetic field resolution, in order to better understand the magnetic, geologic and thermal history of Mars, and at characterizing current atmospheric escape, which is still poorly constrained. These objectives are achieved by using a low periapsis orbit, similar to the one used by the Mars Global Surveyor spacecraft during its aerobraking phases. The proposed periapsis altitude for Dynamo of 120-130 km, coupled with the global distribution of periapses to be obtained during one Martian year of operation, through about 5000 low passes, will produce a magnetic/gravity field data set with approximately five times the spatial resolution of MGS. Low periapsis provides a unique opportunity to investigate the chemical and dynamical properties of the deep ionosphere, thermosphere, and the interaction between the atmosphere and the solar wind, therefore atmospheric escape, which may have played a crucial role in removing atmosphere, and water, from the planet. There is much room for debate on the importance of current atmosphere escape processes in the evolution of the Martian atmosphere, as early "exotic" processes including hydrodynamic escape and impact erosion are traditionally invoked to explain the apparent sparse inventory of present-day volatiles. Yet, the combination of low surface gravity and the absence of a substantial internally generated magnetic field have undeniable effects on what we observe today. In addition to the current losses in the forms of Jeans and photochemical escape of neutrals, there are solar wind interaction-related erosion mechanisms because the upper atmosphere is directly exposed to the solar wind. The solar wind related loss rates, while now comparable to those of a modest comet, nonetheless occur continuously, with the intriguing possibility of important cumulative and

  10. 1994 livestock field investigation of two ranches associated with a pipeline break

    Energy Technology Data Exchange (ETDEWEB)

    Mostrom, M.S.; Campbell, C.A.J.

    1998-11-01

    In January 1994, a pipeline in the Rocky Mountain foothill region of Alberta leaked sour gas and condensate, including volatile hydrocarbons, into the Red Deer River. Cattle on two ranches were within 4 km to less than 0.5 km from the leak site. Once the leak was discovered (about three days after the rupture) the well was shut in and the pipeline was purged of crude petroleum. The cows at both ranches were brought into confined areas for clinical observations. Calving started in mid-January at both ranches. Many of the calves and cows exhibited abnormal behaviour. An investigation into the possible toxicological effects of the leak emissions in cattle was conducted in order to assess the health and productivity of the cattle on the two ranches and to evaluate plausible etiologies for observed adverse effects in the cattle. Another objective was to obtain exposure analyses. Both ranches had a higher mortality in 1994 compared to previous years. Results showed evidence, by way of clinical signs and histopathologic lesions in the respiratory, nervous, and lymphoid tissues, of exposure to volatile hydrocarbons released at the time of the leak and during the subsequent cleanup operations. However, there were also other factors (BVD virus and Salmonella and corona virus infections, neonatal diarrhea, selenium and copper poisoning), that have contributed, although no consistent pattern of disease other than immune dysfunction could explain the high death losses observed among calves on the two ranches. 63 refs., 20 tabs., 12 figs., 5 appendices.

  11. Investigations of ultrafast ligand rebinding to heme and heme proteins using temperature and strong magnetic field perturbations

    Science.gov (United States)

    Zhang, Zhenyu

    This thesis is written to summarize investigations of the mechanisms that underlie the kinetics of diatomic ligand rebinding to the iron atom of the heme group, which is chelated inside heme proteins. The family of heme proteins is a major object of studies for several branches of scientific research activity. Understanding the ligand binding mechanisms and pathways is one of the major goals for biophysics. My interests mainly focus on the physics of this ligand binding process. Therefore, to investigate the problem, isolated from the influence of the protein matrix, Fe-protophorphyrin IX is chosen as the prototype system in my studies. Myoglobin, the most extensively and intensively studied protein, is another ideal system that allows coupling the protein polypeptide matrix into the investigation. A technique to synchro-lock two laser pulse trains electronically is applied to our pump-probe spectroscopic studies. Based on this technique, a two color, fs/ps pump-probe system is developed which extends the temporal window for our investigation to 13ns and fills a gap existing in previous pump-probe investigations. In order to apply this newly-developed pump-probe laser system to implement systematic studies on the kinetics of diatomic ligand (NO, CO, O2) rebinding to heme and heme proteins, several experimental setups are utilized. In Chapter 1, the essential background knowledge, which helps to understand the iron-ligand interaction, is briefly described. In Chapter 2, in addition to a description of the preparation protocols of protein samples and details of the method for data analysis, three home-made setups are described, which include: a picosecond laser regenerative amplifier, a pump-probe application along the bore (2-inch in diameter) of a superconducting magnet and a temperature-controllable cryostat for spinning sample cell. Chapter 3 presents high magnetic field studies of several heme-ligand or protein-ligand systems. Pump-probe spectroscopy is used to

  12. Investigation of scaling characteristics for defining design environments due to transient ground winds and near-field, nonlinear acoustic fields

    Science.gov (United States)

    Shih, C. C.

    1973-01-01

    In order to establish a foundation of scaling laws for the highly nonlinear waves associated with the launch vehicle, the basic knowledge of the relationships among the paramaters pertinent to the energy dissipation process associated with the propagation of nonlinear pressure waves in thermoviscous media is required. The problem of interest is to experimentally investigate the temporal and spacial velocity profiles of fluid flow in a 3-inch open-end pipe of various lengths, produced by the propagation of nonlinear pressure waves for various diaphragm burst pressures of a pressure wave generator. As a result, temporal and spacial characteristics of wave propagation for a parametric set of nonlinear pressure waves in the pipe containing air under atmospheric conditions were determined. Velocity measurements at five sections along the pipes of up to 210 ft. in length were made with hot-film anemometers for five pressure waves produced by a piston. The piston was derived with diaphragm burst pressures at 20, 40, 60, 80 and 100 psi in the driver chamber of the pressure wave generator.

  13. Damage and loss assessment on rubber trees caused by typhoon based on high-precision remote sensing data and field investigation

    Science.gov (United States)

    Li, Jian; Fang, Weihua; Tan, Chenyan

    2016-04-01

    Forest dynamics are highly relevant to land hydrology, climate, carbon budget and biodiversity. Damage and loss assessment of forest caused by typhoon is essential to the understanding of ecosystem variations. Combination of high-precision remote sensing data and field investigation is critical to the assessment of forest damage loss. In this study, high-precision remote sensing data prior to and after typhoon from IKONOS, QuickBird, unmanned aerial vehicle (UAV) are used for identifying rubber tree disturbance. The ground truth data of rubber tree damage collected through field investigation are used to verify and compare the results. Taken the forest damage induced by typhoon Rammasun (201409) in Hainan as an example, 5 damage types (overthrown, trunk snapped below 2m, trunk snapped above 2m, half-overthrown, and sheared) of rubber trees are clearly interpreted compared with field investigation results. High-precision remote sensing data is then applied to other areas to evaluate the forest damage severity. At last, rubber tree damage severity is investigated with other typhoon hazard factors such as wind, topography, soil and precipitation.

  14. Colloid-Facilitated Transport of Low-Solubility Radionuclides: A Field, Experimental, and Modeling Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, A B; Reimus, P W; Abdel-Fattah, A; Allen, P G; Anghel, I; Benedict, F C; Esser, B K; Lu, N; Kung, K S; Nelson, J; Neu, M P; Reilly, S D; Smith, D K; Sylwester, E R; Wang, L; Ware, S D; Warren, RG; Williams, R W; Zavarin, M; Zhao, P

    2003-02-01

    rate of Pu transport. Currently, the role of colloids in facilitating the transport of low-solubility radionuclides is not understood well enough to effectively model contaminant transport. A fundamental understanding of the role that colloids may or may not play in the transport of low-solubility radionuclides is needed in order to predict contaminant transport, design remediation strategies and provide risk assessments. Ryan and Elimelech (1996) have argued that in order to evaluate the potential for colloids to transport radionuclides, several criteria must be met: (1) colloids must exist and be stable, (2) radionuclides must have a high sorption affinity for the colloids, and (3) colloids must be transported. Only then can we understand the conditions where colloids can and will facilitate transport of radionuclides. In this report we compile the results from a series of field, laboratory and modeling studies funded by the UGTA program in order to evaluate the potential for colloids to transport low-solubility radionuclides at the NTS. The studies presented in this report fall under three general areas of investigation: Characterization of natural colloids in groundwater at NTS, Pu sorption/desorption experiments on colloid minerals identified in NTS groundwater, and Transport of Pu-doped colloids through fractured rock core. Chapter 1 is a background review of our current understanding of colloids and their role in facilitating contaminant transport. Chapters 2, and 3 are field studies that focused on characterizing natural colloids at different hydrologic environments at the NTS and address Ryan and Elimelech's (1996) first criteria regarding the existence and stability of colloids. Chapters 4, 5 and 6 are laboratory experimental studies that investigate the sorption/desorption behavior of Pu and other low-solubility radionuclides on colloid minerals observed in NTS groundwater. These studies evaluate Ryan and Elimelech's (1996) second criteria that the

  15. In situ FTIR Investigation of Magnetic Field Effect on Heterogeneous Photocatalytic Degradation of Benzene over Pt/TiO2

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In situ FTIR spectroscopy was utlized to investigate the magnetic field effect on the heterogeneous photocatalytic degradation of benzene over platinized titania (Pt/TiO2). The results revealed that the employment of magnetic field may not change the mechanism of photocatalytic degradation of benzene, however, it greatly facilitate the conversion of benzene to phenol and quinone, as well as the transformation from phenol to quinone, resulting in opening the benzene ring easily and promoting the production of CO2.

  16. Assessment of diabetic retinopathy using nonmydriatic ultra-widefield scanning laser ophthalmoscopy (Optomap) compared with ETDRS 7-field stereo photography.

    Science.gov (United States)

    Kernt, Marcus; Hadi, Indrawati; Pinter, Florian; Seidensticker, Florian; Hirneiss, Christoph; Haritoglou, Christos; Kampik, Anselm; Ulbig, Michael W; Neubauer, Aljoscha S

    2012-12-01

    To compare the diagnostic properties of a nonmydriatic 200° ultra-widefield scanning laser ophthalmoscope (SLO) versus mydriatic Early Treatment of Diabetic Retinopathy Study (ETDRS) 7-field photography for diabetic retinopathy (DR) screening. A consecutive series of 212 eyes of 141 patients with different levels of DR were examined. Grading of DR and clinically significant macular edema (CSME) from mydriatic ETDRS 7-field stereo photography was compared with grading obtained by Optomap Panoramic 200 SLO images. All SLO scans were performed through an undilated pupil, and no additional clinical information was used for evaluation of all images by the two independent, masked, expert graders. Twenty-two eyes from ETDRS 7-field photography and 12 eyes from Optomap were not gradable by at least one grader because of poor image quality. A total of 144 eyes were analyzed regarding DR level and 155 eyes regarding CSME. For ETDRS 7-field photography, 22 eyes (18 for grader 2) had no or mild DR (ETDRS levels ≤ 20) and 117 eyes (111 for grader 2) had no CSME. A highly substantial agreement between both Optomap DR and CSME grading and ETDRS 7-field photography existed with κ = 0.79 for DR and 0.73 for CSME for grader 1, and κ = 0.77 (DR) and 0.77 (CSME) for grader 2. Determination of CSME and grading of DR level from Optomap Panoramic 200 nonmydriatic images show a positive correlation with mydriatic ETDRS 7-field stereo photography. Both techniques are of sufficient quality to assess DR and CSME. Optomap Panoramic 200 images cover a larger retinal area and therefore may offer additional diagnostic properties.

  17. Physiological advantages of C4 grasses in the field: a comparative experiment demonstrating the importance of drought.

    Science.gov (United States)

    Taylor, Samuel H; Ripley, Brad S; Martin, Tarryn; De-Wet, Leigh-Ann; Woodward, F Ian; Osborne, Colin P

    2014-06-01

    Global climate change is expected to shift regional rainfall patterns, influencing species distributions where they depend on water availability. Comparative studies have demonstrated that C4 grasses inhabit drier habitats than C3 relatives, but that both C3 and C4 photosynthesis are susceptible to drought. However, C4 plants may show advantages in hydraulic performance in dry environments. We investigated the effects of seasonal variation in water availability on leaf physiology, using a common garden experiment in the Eastern Cape of South Africa to compare 12 locally occurring grass species from C4 and C3 sister lineages. Photosynthesis was always higher in the C4 than C3 grasses across every month, but the difference was not statistically significant during the wettest months. Surprisingly, stomatal conductance was typically lower in the C3 than C4 grasses, with the peak monthly average for C3 species being similar to that of C4 leaves. In water-limited, rain-fed plots, the photosynthesis of C4 leaves was between 2.0 and 7.4 μmol m(-2) s(-1) higher, stomatal conductance almost double, and transpiration 60% higher than for C3 plants. Although C4 average instantaneous water-use efficiencies were higher (2.4-8.1 mmol mol(-1)) than C3 averages (0.7-6.8 mmol mol(-1)), differences were not as great as we expected and were statistically significant only as drought became established. Photosynthesis declined earlier during drought among C3 than C4 species, coincident with decreases in stomatal conductance and transpiration. Eventual decreases in photosynthesis among C4 plants were linked with declining midday leaf water potentials. However, during the same phase of drought, C3 species showed significant decreases in hydrodynamic gradients that suggested hydraulic failure. Thus, our results indicate that stomatal and hydraulic behaviour during drought enhances the differences in photosynthesis between C4 and C3 species. We suggest that these drought responses are

  18. Physiological advantages of C4 grasses in the field: a comparative experiment demonstrating the importance of drought

    Science.gov (United States)

    Taylor, Samuel H; Ripley, Brad S; Martin, Tarryn; De-Wet, Leigh-Ann; Woodward, F Ian; Osborne, Colin P

    2014-01-01

    Global climate change is expected to shift regional rainfall patterns, influencing species distributions where they depend on water availability. Comparative studies have demonstrated that C4 grasses inhabit drier habitats than C3 relatives, but that both C3 and C4 photosynthesis are susceptible to drought. However, C4 plants may show advantages in hydraulic performance in dry environments. We investigated the effects of seasonal variation in water availability on leaf physiology, using a common garden experiment in the Eastern Cape of South Africa to compare 12 locally occurring grass species from C4 and C3 sister lineages. Photosynthesis was always higher in the C4 than C3 grasses across every month, but the difference was not statistically significant during the wettest months. Surprisingly, stomatal conductance was typically lower in the C3 than C4 grasses, with the peak monthly average for C3 species being similar to that of C4 leaves. In water-limited, rain-fed plots, the photosynthesis of C4 leaves was between 2.0 and 7.4 μmol m−2 s−1 higher, stomatal conductance almost double, and transpiration 60% higher than for C3 plants. Although C4 average instantaneous water-use efficiencies were higher (2.4–8.1 mmol mol−1) than C3 averages (0.7–6.8 mmol mol−1), differences were not as great as we expected and were statistically significant only as drought became established. Photosynthesis declined earlier during drought among C3 than C4 species, coincident with decreases in stomatal conductance and transpiration. Eventual decreases in photosynthesis among C4 plants were linked with declining midday leaf water potentials. However, during the same phase of drought, C3 species showed significant decreases in hydrodynamic gradients that suggested hydraulic failure. Thus, our results indicate that stomatal and hydraulic behaviour during drought enhances the differences in photosynthesis between C4 and C3 species. We suggest that these drought responses

  19. Mapping the field of medical sociology: a comparative analysis of journals.

    Science.gov (United States)

    Seale, Clive

    2008-07-01

    A comparative keyword analysis of the content of nine leading journals is used to suggest potential new directions for medical sociology. The major British and American journals in sociology and medical sociology tend to publish authors based in their own countries, contrasting with the internationalism of other social science disciplines relevant to health, although Sociology of Health and Illness is an exception to this. Medical sociology journals on both sides of the Atlantic focus on individual experience more than general sociology journals, which focus more on social systems levels of analysis. While journal contents reveal British medical sociology to be relatively atheoretical when compared with British general sociology journals, American medical sociology appears relatively apolitical on the same comparison with American general journals. American journals of sociology publish more quantitative studies than their British equivalents, more studies concerning race and other social divisions in American society, and less work drawing on social constructionist perspectives or that is engaged with social theory. Analysis of health and health care at societal and global levels and a deeper engagement with the political and public issues that concern non-sociologists represents a possible future for a medical sociology that is internationally relevant and outward looking.

  20. Investigating the origin of cyclical wind variability in hot, massive stars - I. On the dipolar magnetic field hypothesis

    CERN Document Server

    David-Uraz, A; Petit, V; ud-Doula, A; Sundqvist, J O; Grunhut, J; Shultz, M; Neiner, C; Alecian, E; Henrichs, H F; Bouret, J -C

    2014-01-01

    OB stars exhibit various types of spectral variability associated with wind structures, including the apparently ubiquitous discrete absorption components (DACs). These are proposed to be caused by either magnetic fields or non-radial pulsations (NRPs). In this paper, we evaluate the possible relation between large-scale, dipolar magnetic fields and the DAC phenomenon by investigating the magnetic properties of a sample of 13 OB stars exhibiting well-documented DAC behaviour. Using high-precision spectropolarimetric data acquired in part in the context of the Magnetism in Massive Stars (MiMeS) project, we find no evidence for surface dipolar magnetic fields in any of these stars. Using Bayesian inference, we compute upper limits on the strengths of the fields and use these limits to assess two potential mechanisms by which the field may influence wind outflow: magnetic wind confinement and local photospheric brightness enhancements. Within the limits we derive, both mechanisms fail to provide a systematic pro...