WorldWideScience

Sample records for flux density relationship

  1. Planck intermediate results - LII. Planet flux densities

    DEFF Research Database (Denmark)

    Akrami, Y.; Ashdown, M.; Aumont, J.

    2017-01-01

    Measurements of flux density are described for five planets, Mars, Jupiter, Saturn, Uranus, and Neptune, across the six Planck High Frequency Instrument frequency bands (100–857 GHz) and these are then compared with models and existing data. In our analysis, we have also included estimates of the...... experiments. In particular, we observe that the flux densities measured by Planck HFI and WMAP agree to within 2%. These results allow experiments operating in the mm-wavelength range to cross-calibrate against Planck and improve models of radiative transport used in planetary science....

  2. Sensors for Metering Heat Flux Area Density and Metrological Equipment for the Heat Flux Density Measurement

    Science.gov (United States)

    Doronin, D. O.

    2018-04-01

    The demand in measuring and studies of heat conduction of various media is very urgent now. This article considers the problem of heat conduction monitoring and measurement in various media and materials in any industries and branches of science as well as metrological support of the heat flux measurement equipment. The main study objects are both the sensors manufactured and facilities onto which these sensors will be installed: different cladding structures of the buildings, awnings, rocket fairings, boiler units, internal combustion engines. The Company develops and manufactures different types of heat flux sensors: thermocouple, thin-film, heterogeneous gradient as well as metrological equipment for the gauging calibration of the heat flux density measurement. The calibration shall be performed using both referencing method in the unit and by fixed setting of the heat flux in the unit. To manufacture heterogeneous heat flux gradient sensors (HHFGS) the Company developed and designed a number of units: diffusion welding unit, HHFGS cutting unit. Rather good quality HHFGS prototypes were obtained. At this stage the factory tests on the equipment for the heat flux density measurement equipment are planned. A high-sensitivity heat flux sensor was produced, now it is tested at the Construction Physics Research Institute (Moscow). It became possible to create thin-film heat flux sensors with the sensitivity not worse than that of the sensors manufactured by Captec Company (France). The Company has sufficient premises to supply the market with a wide range of sensors, to master new sensor manufacture technologies which will enable their application range.

  3. Manifestation of solar activity in solar wind particle flux density

    International Nuclear Information System (INIS)

    Kovalenko, V.A.

    1988-01-01

    An analysis has been made of the origin of long-term variations in flux density of solar wind particles (nv) for different velocity regimes. The study revealed a relationship of these variations to the area of the polar coronal holes (CH). It is shown that within the framework of the model under development, the main longterm variations of nv are a result of the latitude redistribution of the solar wind mass flux in the heliosphere and are due to changes in the large-scale geometry of the solar plasma flow in the corona. A study has been made of the variations of nv for high speed solar wind streams. It is found that nv in high speed streams which are formed in CH, decreases from minimum to maximum solar activity. The analysis indicates that this decrease is attributable to the magnetic field strength increase in coronal holes. It has been found that periods of rapid global changes of background magnetic fields on the Sun are accompanied by a reconfiguration of coronal magnetic fields, rapid changes in the length of quiescent filaments, and by an increase in the density of the particle flux of a high speed solar wind. It has been established that these periods precede the formation of CH, corresponding to the increase in solar wind velocity near the Earth and to enhancement of the level of geomagnetic disturbance. (author)

  4. Device for measuring neutron-flux distribution density

    International Nuclear Information System (INIS)

    Rozenbljum, N.D.; Mitelman, M.G.; Kononovich, A.A.; Kirsanov, V.S.; Zagadkin, V.A.

    1977-01-01

    An arrangement is described for measuring the distribution of neutron flux density over the height of a nuclear reactor core and which may be used for monitoring energy release or for detecting deviations of neutron flux from an optimal level so that subsequent balance can be achieved. It avoids mutual interference of detectors. Full constructional details are given. (UK)

  5. Evaluation of Density Corrections to Methane Fluxes Measured by Open-Path Eddy Covariance over Contrasting Landscapes

    Science.gov (United States)

    Chamberlain, Samuel D.; Verfaillie, Joseph; Eichelmann, Elke; Hemes, Kyle S.; Baldocchi, Dennis D.

    2017-11-01

    Corrections accounting for air density fluctuations due to heat and water vapour fluxes must be applied to the measurement of eddy-covariance fluxes when using open-path sensors. Experimental tests and ecosystem observations have demonstrated the important role density corrections play in accurately quantifying carbon dioxide (CO2) fluxes, but less attention has been paid to evaluating these corrections for methane (CH4) fluxes. We measured CH4 fluxes with open-path sensors over a suite of sites with contrasting CH4 emissions and energy partitioning, including a pavement airfield, two negligible-flux ecosystems (drained alfalfa and pasture), and two high-flux ecosystems (flooded wetland and rice). We found that density corrections successfully re-zeroed fluxes in negligible-flux sites; however, slight overcorrection was observed above pavement. The primary impact of density corrections varied over negligible- and high-flux ecosystems. For negligible-flux sites, corrections led to greater than 100% adjustment in daily budgets, while these adjustments were only 3-10% in high-flux ecosystems. The primary impact to high-flux ecosystems was a change in flux diel patterns, which may affect the evaluation of relationships between biophysical drivers and fluxes if correction bias exists. Additionally, accounting for density effects to high-frequency CH4 fluctuations led to large differences in observed CH4 flux cospectra above negligible-flux sites, demonstrating that similar adjustments should be made before interpreting CH4 cospectra for comparable ecosystems. These results give us confidence in CH4 fluxes measured by open-path sensors, and demonstrate that density corrections play an important role in adjusting flux budgets and diel patterns across a range of ecosystems.

  6. Magnetic flux density in the heliosphere through several solar cycles

    Energy Technology Data Exchange (ETDEWEB)

    Erdős, G. [Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Balogh, A., E-mail: erdos.geza@wigner.mta.hu [The Blackett Laboratory, Imperial College London, London SW7 2BZ (United Kingdom)

    2014-01-20

    We studied the magnetic flux density carried by solar wind to various locations in the heliosphere, covering a heliospheric distance range of 0.3-5.4 AU and a heliolatitudinal range from 80° south to 80° north. Distributions of the radial component of the magnetic field, B{sub R} , were determined over long intervals from the Helios, ACE, STEREO, and Ulysses missions, as well as from using the 1 AU OMNI data set. We show that at larger distances from the Sun, the fluctuations of the magnetic field around the average Parker field line distort the distribution of B{sub R} to such an extent that the determination of the unsigned, open solar magnetic flux density from the average (|B{sub R} |) is no longer justified. We analyze in detail two methods for reducing the effect of fluctuations. The two methods are tested using magnetic field and plasma velocity measurements in the OMNI database and in the Ulysses observations, normalized to 1 AU. It is shown that without such corrections for the fluctuations, the magnetic flux density measured by Ulysses around the aphelion phase of the orbit is significantly overestimated. However, the matching between the in-ecliptic magnetic flux density at 1 AU (OMNI data) and the off-ecliptic, more distant, normalized flux density by Ulysses is remarkably good if corrections are made for the fluctuations using either method. The main finding of the analysis is that the magnetic flux density in the heliosphere is fairly uniform, with no significant variations having been observed either in heliocentric distance or heliographic latitude.

  7. Correlation between the Flux Density and Polarization for Flat ...

    Indian Academy of Sciences (India)

    In this paper, using the preliminary database of the University of Michigan Radio Astronomy Observatory (UMRAO) at the radio frequencies, we calculated the weighted polarization at 8 GHz and investigated the correlation between the polarization and the flux density for 92 flat spectrum radio quasars (FSRQs). We found ...

  8. Correlation between the Flux Density and Polarization for Flat ...

    Indian Academy of Sciences (India)

    blazars, which show high and variable polarization, rapid variable flux density over different time scales (Fan 2005). Blazars consist of flat spectrum radio quasars. (FSRQs) and BL Lacertae objects (BLs). FSRQs are quite similar to BLs except for their emission line feature with FSRQs showing strong emission lines while.

  9. Correlation between the Flux Density and Polarization for Flat ...

    Indian Academy of Sciences (India)

    3Guangzhou Vocational College of Technology & Business, Guangzhou, China. 4Center for Astrophysics ... blazars, which show high and variable polarization, rapid variable flux density over different time scales (Fan ... emission lines while. BLs show very weak emission line feature or have only non-emission lines. The.

  10. Density variations of meteor flux along the Earth's orbit

    International Nuclear Information System (INIS)

    Svetashkova, N.T.

    1987-01-01

    No model of distribution of meteor substance is known to explain the observed diurnal and annual variations of meteor rates, if that distribution is assumed to be constant during the year. Differences between the results of observations and the prediction of diurnal variation rates leads to the conclusion that the density of the orbits of meteor bodies changes with the motion of the Earth along its orbit. The distributions of the flux density over the celestial sphere are obtained by the method described previously by Svetashkova, 1984. The results indicate that the known seasonal and latitudinal variations of atmospheric conditions does not appear to significantly affect the value of the mean flux density of meteor bodies and the matter influx onto the Earth

  11. Leaf conductance response of phaseolus vulgaris to ozone flux density

    Science.gov (United States)

    Amiro, B. D.; Gillespie, T. J.

    The effect of ozone flux density on leaf conductance to ozone in Phaseolus vulgaris was examined. The change in conductance was measured within the first two hours of fumigation for mature, fruiting 6-week-old plants of an ozone sensitive cultivar (Seafarer); for young, 14-day-old plants of the same cultivar; and for an ozone resistant cultivar (Gold Crop). Young Seafarer plants showed no change in conductance to ozone over a wide range of ozone flux densities. Gold Crop showed a decrease in conductance of -3.1 % /(mgO 3 m -2 h -1) whereas mature Seafarer plants exhibited a stronger decrease of -7.7% /(mgO 3 m -2 h -1). Diffusion porometer measurements taken on fruiting Seafarer plants in the field illustrated that a decrease in leaf diffusive conductance to water is related to visual ozone injury.

  12. A fast gauge for energy flux density measurement

    Science.gov (United States)

    Garcia, Jorge; Bana de Schor, Beatriz

    1990-01-01

    Herein, the design and characterization of a fast energy flux density gauge are described. The gauge is based on a thermoelectrical pair with the junction made of a thin layer of silver. High absorptivity is attained by an electrolytic deposit of platinum black on the silver coat. Dynamic calibration gives a response time below 100 microsec. Computer methods to obtain the energy flux density from temperature-time history were evaluated. The results of the tests performed with igniters of pelleted boron/potassium nitrate and black powder, used in solid propellant ignition, are shown. The gauge developed can be applied to fast processes which require small response time. The gauge does not need previous calibration, it is resistant to vibrations and accelerations, and, at the same time, it is small in size, economical, and easy to build.

  13. Internal wave energy flux from density perturbations in nonlinear stratifications

    Science.gov (United States)

    Lee, Frank M.; Allshouse, Michael R.; Swinney, Harry L.; Morrison, P. J.

    2017-11-01

    Tidal flow over the topography at the bottom of the ocean, whose density varies with depth, generates internal gravity waves that have a significant impact on the energy budget of the ocean. Thus, understanding the energy flux (J = p v) is important, but it is difficult to measure simultaneously the pressure and velocity perturbation fields, p and v . In a previous work, a Green's-function-based method was developed to calculate the instantaneous p, v , and thus J , given a density perturbation field for a constant buoyancy frequency N. Here we extend the previous analytic Green's function work to include nonuniform N profiles, namely the tanh-shaped and linear cases, because background density stratifications that occur in the ocean and some experiments are nonlinear. In addition, we present a finite-difference method for the general case where N has an arbitrary profile. Each method is validated against numerical simulations. The methods we present can be applied to measured density perturbation data by using our MATLAB graphical user interface EnergyFlux. PJM was supported by the U.S. Department of Energy Contract DE-FG05-80ET-53088. HLS and MRA were supported by ONR Grant No. N000141110701.

  14. Calibration corrections of solar tower flux density measurements

    International Nuclear Information System (INIS)

    Ulmer, Steffen; Luepfert, Eckhard; Pfaender, Markus; Buck, Reiner

    2004-01-01

    The PSA flux density measuring system PROHERMES measures the concentrated solar radiation in the entrance aperture of solar tower receivers with a white rotating bar as target and a CCD-camera taking images. The calibration is done with commercial flux gauges placed in the measurement plane. To improve the calibration of the system and to reveal systematic errors, measurements are performed with two different types of commercial flux gauges (Thermogage sensors with and without quartz window) and a large custom-made calorimeter used as reference. The comparison shows that the sensors without quartz window measure about 5-8% higher and the sensors with quartz window about 100% higher. This error is explained with the differences in the spectral composition of the radiation and different angles of incidence between the manufacturer calibration and the solar measurements and corrections are proposed. Spectral changes of the sunlight during the day and year can affect the measurements by more than 10%. By selecting a correction filter adapted to the camera sensitivity, this influence can be reduced to less than 2.5%. Due to the reflective properties of the target coating, changes in angle of incidence can affect the measurements. In standard solar field conditions, this error is less than 0.5%, but for special conditions a correction of the systematic error of up to 8% is proposed

  15. Electromagnetic potentials basis for energy density and power flux

    International Nuclear Information System (INIS)

    Puthoff, H E

    2016-01-01

    In rounding out the education of students in advanced courses in applied electromagnetics it is incumbent on us as mentors to raise issues that encourage appreciation of certain subtle aspects that are often overlooked during first exposure to the field. One of these has to do with the interplay between fields and potentials, with the latter often seen as just a convenient mathematical artifice useful in solving Maxwell’s equations. Nonetheless, to those practiced in application it is well understood that various alternatives in the use of fields and potentials are available within electromagnetic (EM) theory for the definitions of energy density, momentum transfer, EM stress–energy tensor, and so forth. Although the various options are all compatible with the basic equations of electrodynamics (e.g., Maxwell’s equations, Lorentz force law, gauge invariance), nonetheless certain alternative formulations lend themselves to being seen as preferable to others with regard to the transparency of their application to physical problems of interest. Here we argue for the transparency of an energy density/power flux option based on the EM potentials alone. (paper)

  16. Flux Loop Measurements of the Magnetic Flux Density in the CMS Magnet Yoke

    CERN Document Server

    Klyukhin, V I; Ball, A.; Curé, B.; Gaddi, A.; Gerwig, H.; Mulders, M.; Hervé, A.; Loveless, R.

    2016-01-01

    The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10,000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. To measure the field in and around the steel, a system of 22 flux loops and 82 3-D Hall sensors is installed on the return yoke blocks. A TOSCA 3-D model of the CMS magnet is developed to describe the magnetic field everywhere outside the tracking volume measured with the field-mapping machine. The first attempt is made to measure the magnetic flux density in the steel blocks of the CMS magnet yoke using the standard magnet discharge with the current ramp down speed of 1.5 A/...

  17. SINUPERM N: a new digital neutron flux density monitoring system

    International Nuclear Information System (INIS)

    Flick, H.A.

    1993-01-01

    The new SINUPERM N System is developed for Neutron Monitoring in nuclear power plants. The development was started in 1989 (with the design specification) and will be finished in 1993 (with the qualification). The first built will be the nuclear power plant in Borselle (Netherlands). The design is based on a microprocessor system with a digital signal processor for calculations and signal filtering. The separation between analogue-input signals and digital processing enables for each detector type special input modules and standard output interfaces e.g. field - bus. The wide range of the Neutron Flux Density from 10 -2 cm -2 s -1 up to 10 8 cm -2 s -1 for the out-of-pile instrumentation and up to 10 14 cm -2 s -1 for the in-core-instrumentation will be covered by the SINUPERM N system. The requirements to be met by the SINUPERM N system are the IEEE 323, IEC 987 and the German standard KTA-3503 for safety systems. Other standards for instrumentation and control systems like IEC 801, IEC 1131 and IEC 68 for EMV, climatic and seismic requirements are also included in the hardware type test. The software requirement depends on the IEC 880 standard. (author). 3 figs

  18. A new empirical model to estimate hourly diffuse photosynthetic photon flux density

    Science.gov (United States)

    Foyo-Moreno, I.; Alados, I.; Alados-Arboledas, L.

    2018-05-01

    Knowledge of the photosynthetic photon flux density (Qp) is critical in different applications dealing with climate change, plant physiology, biomass production, and natural illumination in greenhouses. This is particularly true regarding its diffuse component (Qpd), which can enhance canopy light-use efficiency and thereby boost carbon uptake. Therefore, diffuse photosynthetic photon flux density is a key driving factor of ecosystem-productivity models. In this work, we propose a model to estimate this component, using a previous model to calculate Qp and furthermore divide it into its components. We have used measurements in urban Granada (southern Spain), of global solar radiation (Rs) to study relationships between the ratio Qpd/Rs with different parameters accounting for solar position, water-vapour absorption and sky conditions. The model performance has been validated with experimental measurements from sites having varied climatic conditions. The model provides acceptable results, with the mean bias error and root mean square error varying between - 0.3 and - 8.8% and between 9.6 and 20.4%, respectively. Direct measurements of this flux are very scarce so that modelling simulations are needed, this is particularly true regarding its diffuse component. We propose a new parameterization to estimate this component using only measured data of solar global irradiance, which facilitates its use for the construction of long-term data series of PAR in regions where continuous measurements of PAR are not yet performed.

  19. Radon and thoron flux densities from some of NSW coal ash dams

    Energy Technology Data Exchange (ETDEWEB)

    Zahorowski, W.; Whittlestone, S. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Malfroy, H.; Davies, P. [Pacific Power Ltd., Sydney, NSW (Australia)

    1994-12-31

    The use of coal as an energy source can cause some potential environmental and human health hazards associated with radionuclides mobilized by the coal fuel cycle. The objective of this study was to assess environmental significance of radon and thoron emissions from New South Wales coal ash storage dams operated by Pacific Power. To achieve this objective radon and thoron flux densities were measured from selected ash dams and mine spoil areas. It was found that: (i) ash dams currently in operation exhibit significantly lower flux densities than average values for Australian soils, and (ii) ash dams under rehabilitation and mine spoils have flux densities comparable to Australian soil. 18 refs., 2 tabs.

  20. Calculated neutron dose rates and flux densities from implantable californium-252 point and line sources.

    Science.gov (United States)

    Shapiro, A; Schwartz, B; Windham, J P; Kereiakes, J G

    1976-01-01

    The results of neutron-transport flux-density and dose rate calculations for implantable Californium-252 point and line sources in essentially infinite tissue-equivalent material are presented. The point-source flux densities were obtained from a discrete ordinates calculation, and the point dose rates were established by multiplying the flux densities by their appropriate kerma factors. Line-source dose rates were evaluated by integrating the point dose rates over the length of the line source. Dose-rate data are given within a 20 X 20-cm region from the source center for source lengths of 1.5, 2, and 3 cm. The dose rates established by these calculations showed good agreement with an independent Monte Carlo calculation. Detailed point-source flux-density data as a function of energy and position are also given.

  1. Transport calculations of gamma ray flux density and dose rate about implantable californium-252 sources.

    Science.gov (United States)

    Shapiro, A; Lin, B I; Windham, J P; Kereiakes, J G

    1976-07-01

    Gamma flux density and dose rate distributions have been calculated about implantable californium-252 sources for an infinite tissue medium. Point source flux densities as a function of energy and position were obtained from a discrete-ordinates calculation, and the flux densities were multiplied by their corresponding kerma factors and added to obtain point source dose rates. The point dose rates were integrated over the line source to obtain line source dose rates. Container attenuation was accounted for by evaluating the point dose rate as a function of platinum thickness. Both primary and secondary flux densities and dose rates are presented. The agreement with an independent Monte Carlo calculation was excellent. The data presented should be useful for the design of new source configurations.

  2. Abnormal changes in the density of thermal neutron flux in biocenoses near the earth surface.

    Science.gov (United States)

    Plotnikova, N V; Smirnov, A N; Kolesnikov, M V; Semenov, D S; Frolov, V A; Lapshin, V B; Syroeshkin, A V

    2007-04-01

    We revealed an increase in the density of thermal neutron flux in forest biocenoses, which was not associated with astrogeophysical events. The maximum spike of this parameter in the biocenosis reached 10,000 n/(sec x m2). Diurnal pattern of the density of thermal neutron flux depended only on the type of biocenosis. The effects of biomodulation of corpuscular radiation for balneology are discussed.

  3. Flux-profile relationships over a fetch limited beech forest

    DEFF Research Database (Denmark)

    Dellwik, E.; Jensen, N.O.

    2005-01-01

    heat flux and momentum (phi(h) and phi(m)) and analysed as a function of atmospheric stability and fetch. For heat, the influences of the roughness sublayer and the internal boundary layer were in agreement with previous studies. For momentum, the strong vertical gradient of the flow just above...... surface. The different influence of the roughness sublayer on phi(h) and phi(m) is reflected in the aerodynamic resistance for the site. The aerodynamic resistance for sensible heat is considerably smaller than the corresponding value for momentum.......The influence of an internal boundary layer and a roughness sublayer on flux-profile relationships for momentum and sensible heat have been investigated for a closed beech forest canopy with limited fetch conditions. The influence was quantified by derivation of local scaling functions for sensible...

  4. Estimating the amount and distribution of radon flux density from the soil surface in China

    International Nuclear Information System (INIS)

    Zhuo Weihai; Guo Qiuju; Chen Bo; Cheng Guan

    2008-01-01

    Based on an idealized model, both the annual and the seasonal radon ( 222 Rn) flux densities from the soil surface at 1099 sites in China were estimated by linking a database of soil 226 Ra content and a global ecosystems database. Digital maps of the 222 Rn flux density in China were constructed in a spatial resolution of 25 km x 25 km by interpolation among the estimated data. An area-weighted annual average 222 Rn flux density from the soil surface across China was estimated to be 29.7 ± 9.4 mBq m -2 s -1 . Both regional and seasonal variations in the 222 Rn flux densities are significant in China. Annual average flux densities in the southeastern and northwestern China are generally higher than those in other regions of China, because of high soil 226 Ra content in the southeastern area and high soil aridity in the northwestern one. The seasonal average flux density is generally higher in summer/spring than winter, since relatively higher soil temperature and lower soil water saturation in summer/spring than other seasons are common in China

  5. Measuring the Magnetic Flux Density in the CMS Steel Yoke

    CERN Document Server

    Klyukhin, V I; Ball, A; Curé, B; Gaddi, A; Gerwig, H; Hervé, A; Mulders, M; Loveless, R

    2012-01-01

    The Compact Muon Solenoid (CMS) is a general purpose detector, designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6-m-diameter by 12.5-m-length free bore, enclosed inside a 10000-ton return yoke made of construction steel. The return yoke consists of five dodecagonal three-layered barrel wheels and four end-cap disks at each end comprised of steel blocks up to 620 mm thick, which serve as the absorber plates of the muon detection system. Accurate characterization of the magnetic field everywhere in the CMS detector is required. To measure the field in and around the steel, a system of 22 flux-loops and 82 3-D Hall sensors is installed on the return yoke blocks. Fast discharges of the solenoid (190 s time-constant) made during the CMS magnet surface commissioning test at the solenoid central fields of 2.64, 3.16, 3.68 and 4.01 T were used to induce voltages in the flux-loops. The voltages are measured on-line a...

  6. Modeling of Fluctuating Mass Flux in Variable Density Flows

    Science.gov (United States)

    So, R. M. C.; Mongia, H. C.; Nikjooy, M.

    1983-01-01

    The approach solves for both Reynolds and Favre averaged quantities and calculates the scalar pdf. Turbulent models used to close the governing equations are formulated to account for complex mixing and variable density effects. In addition, turbulent mass diffusivities are not assumed to be in constant proportion to turbulent momentum diffusivities. The governing equations are solved by a combination of finite-difference technique and Monte-Carlo simulation. Some preliminary results on simple variable density shear flows are presented. The differences between these results and those obtained using conventional models are discussed.

  7. Determination of neutron flux densities in WWR-S reactor core

    International Nuclear Information System (INIS)

    Tomasek, F.

    1989-04-01

    The method is described of determining neutron flux densities and neutron fluences using activation detectors. The basic definitions and relations for determining reaction rates, fluence and neutron flux as well as the characteristics of some reactions and of sitable activation detectors are reported. The flux densities were determined of thermal and fast neutrons and of gamma quanta in the WWR-S reactor core. The data measured in the period 1984-1987 are tabulated. Cross sections for the individual reactions were determined from spectra measurements processed using program SAND-II and cross section library ENDF-B IV. Neutron flux densities were also measured for the WWR-S reactor vertical channels. (E.J.). 10 figs., 8 tabs., 111 refs

  8. 3D density imaging with muons flux measurements from underground galleries

    Science.gov (United States)

    Lesparre, Nolwenn; Cabrera, Justo; Marteau, Jacques

    2016-04-01

    Atmospheric muons flux measurements provide information on sub-surface density distribution, giving insights on the medium structure. We measured the muons flux from the underground galleries of the Tournemire experimental platform to image the medium between the galleries and the surface. The experiment aimed at evaluating the capacity of the method to detect the presence of discontinuities produced either by secondary strike-slip faults that present small vertical displacements or by a karstic network may be present at the level of an upper aquifer. Measurements were performed from three different sites so the trajectories of detected muons paths intersect in the medium. Such a configuration provided complementary information on the density distribution, offering the possibility to seek density variations at different depths. A specific calibration method was applied in order to interpolate the data acquired at different times with the same muons sensor. Muons flux measurements variations were then processed through a non-linear inversion, producing a 3D image of the density together with an evaluation of the different distinguished targets reliability. The density distribution showed the presence of a very low density region at the level of the upper aquifer, suggesting the presence of a karstic network hosting locally cavities. The trace of secondary strike-slip faults did not appear clearly on the image as the density contrast they produce might be too low compared to the signal to noise ratio present in the muons flux data. We propose different strategies to improve the density image accuracy.

  9. Flux depression and the absolute measurement of the thermal neutron flux density

    International Nuclear Information System (INIS)

    Bensch, Friedrich.

    1977-01-01

    The thermal neutron flux depression in a diffusing medium by an absorbing foil has been treated in numerous papers. The results are re-examined in an attempt to find a uniform and physically meaningful representation of the 'activation correction'. This quantity can be split up into a combination of probabilities. Thus, it is possible to determine the activation correction for any moderator and foil material. Measurements confirm the utility of the concepts introduced

  10. 3-D density imaging with muon flux measurements from underground galleries

    Science.gov (United States)

    Lesparre, N.; Cabrera, J.; Marteau, J.

    2017-03-01

    Atmospheric muon flux measurements provide information on subsurface density distribution. In this study, muon flux was measured underground, in the Tournemire experimental platform (France). The objective was to image the medium between the galleries and the surface and evaluate the feasibility to detect the presence of discontinuities, for example, produced by secondary subvertical faults or by karstic networks. Measurements were performed from three different sites with a partial overlap of muon trajectories, offering the possibility to seek density variations at different depths. The conversion of the measured muon flux to average density values showed global variations further analysed through a 3-D nonlinear inversion procedure. Main results are the presence of a very low density region at the level of the upper aquifer, compatible with the presence of a karstic network hosting local cavities, and the absence of secondary faults. We discuss the validity of the present results and propose different strategies to improve the accuracy of such measurements and analysis.

  11. Expansion Of The Magnetic Flux Density Field In Toroidal Harmonics

    CERN Document Server

    Gambini, Laura; Bottura, Luca; Felcini, Enrico

    CERN (Conseil Européen pour la Recherche Nucléaire) is recognized worldwide as the main research laboratory in the field of particle physics. Inevitably, all this requires the use of the most advanced technologies, both from the point of view of the instruments and the analytical descriptive methods. One of the numerous potentials of the work carried out at CERN concerns the possibility of exploiting the aforementioned technologies even in contexts distant from the physics of particles, with the result of influencing the technological advancement of many areas. For example, one of the most widely employed theories at CERN, regarding the analytical description of the magnetic flux density inside solenoidal magnets (or approximable as such under suitable assumptions) for the acceleration of particles, is the so-called multipole expansion. This is a two-dimensional or three-dimensional analysis of the distribution of the magnetic flux density generated by the windings of a magnet. The magnet in question ca...

  12. Magnetic flux density reconstruction using interleaved partial Fourier acquisitions in MREIT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Myung [Department of Veterinary Internal Medicine, College of Veterinary Medicine, Konkuk University (Korea, Republic of); Nam, Hyun Soo; Kwon, Oh In, E-mail: oikwon@konkuk.ac.kr [Department of Mathematics, Konkuk University (Korea, Republic of)

    2011-04-07

    Magnetic resonance electrical impedance tomography (MREIT) has been introduced as a non-invasive modality to visualize the internal conductivity and/or current density of an electrically conductive object by the injection of current. In order to measure a magnetic flux density signal in MREIT, the phase difference approach in an interleaved encoding scheme cancels the systematic artifacts accumulated in phase signals and also reduces the random noise effect. However, it is important to reduce scan duration maintaining spatial resolution and sufficient contrast, in order to allow for practical in vivo implementation of MREIT. The purpose of this paper is to develop a coupled partial Fourier strategy in the interleaved sampling in order to reduce the total imaging time for an MREIT acquisition, whilst maintaining an SNR of the measured magnetic flux density comparable to what is achieved with complete k-space data. The proposed method uses two key steps: one is to update the magnetic flux density by updating the complex densities using the partially interleaved k-space data and the other is to fill in the missing k-space data iteratively using the updated background field inhomogeneity and magnetic flux density data. Results from numerical simulations and animal experiments demonstrate that the proposed method reduces considerably the scanning time and provides resolution of the recovered B{sub z} comparable to what is obtained from complete k-space data.

  13. Research and Evaluation of the Energy Flux Density of the Mobile Phone Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2012-12-01

    Full Text Available The article analyses variations in the energy flux density of the electromagnetic field of 10 mobile phones depending on distance. The studies have been conducted using three modes: sending a text message, receiving a text message and connecting a mobile phone to the Internet. When text messages are received or sent from a mobile phone, the values of the energy flux density of the mobile phone electromagnetic field exceed the safe allowable limit and make 10 μW / cm². A distance of 10, 20 and 30 cm from a mobile phone is effective protection against the energy flux density of the electromagnetic field when writing texts, receiving messages or connecting to the mobile Internet.Article in Lithuanian

  14. Minnealloy: a new magnetic material with high saturation flux density and low magnetic anisotropy

    Science.gov (United States)

    Mehedi, Md; Jiang, Yanfeng; Suri, Pranav Kumar; Flannigan, David J.; Wang, Jian-Ping

    2017-09-01

    We are reporting a new soft magnetic material with high saturation magnetic flux density, and low magnetic anisotropy. The new material is a compound of iron, nitrogen and carbon, α‧-Fe8(NC), which has saturation flux density of 2.8  ±  0.15 T and magnetic anisotropy of 46 kJ m-3. The saturation flux density is 27% higher than pure iron, a widely used soft magnetic material. Soft magnetic materials are very important building blocks of motors, generators, inductors, transformers, sensors and write heads of hard disk. The new material will help in the miniaturization and efficiency increment of the next generation of electronic devices.

  15. Evaluation of soil heat flux density as a function of soil management practices

    Science.gov (United States)

    Moratiel Yugueros, R.; García Moreno, R.

    2012-04-01

    Soil energy is an important parameter in order to understand the flux of energy between the plant and the soil. This parameter could determine the potential for future production of soil. Pattern of surface energy flux varies depending on several factors, mainly on coverage. Also, this behaviour is strongly conditioned by the physical condition of soil. In order to evaluate the trend and behaviour of soil energy depending on soil coverage the aim of the present study was to evaluate soil heat flux density (G) in three different soil conditions depending on seasonal weather temperatures. Therefore, the authors monitored soil energy every half hour from soil located on bare soil, on soil covered by crops at root level and in between crop rows. The selected crop was corn. Soil heat flux density was measured with a heat flux plate sensor buried at a depth of 0.05 m in experimental sites. The change in heat storage in the soil layer above the heat flux plates was measured by inserting temperature sensors at an angle from near the bottom to near the top of the soil layer (above the plate sensor). The results indicated that the soil energy flux depends mainly on radiation and soil conditions. Although net radiation (Rn) was the same for all the sites, the evolution for G is different. Greater G fluctuation is produced in bared soils and decreases as soil is covered by the crops, especially at root level.

  16. Forest canopy temperatures: dynamics, controls, and relationships with ecosystem fluxes

    Science.gov (United States)

    Still, C. J.; Griffith, D.; Kim, Y.; Law, B. E.; Hanson, C. V.; Kwon, H.; Schulze, M.; Detto, M.; Pau, S.

    2017-12-01

    Temperature strongly affects enzymatic reactions, ecosystem biogeochemistry, and species distributions. Although most focus is on air temperature, the radiative or skin temperature of plants is more relevant. Canopy skin temperature dynamics reflect biophysical, physiological, and anatomical characteristics and interactions with the environment, and can be used to examine forest responses to stresses like droughts and heat waves. Thermal infrared (TIR) imaging allows for extensive temporal and spatial sampling of canopy temperatures, particularly compared to spot measurements using thermocouples. We present results of TIR imaging of forest canopies at eddy covariance flux tower sites in the US Pacific Northwest and in Panama. These forests range from an old-growth temperate rainforest to a second growth semi-arid pine forest to a semi-deciduous tropical forest. Canopy temperature regimes at these sites are highly variable. Canopy temperatures at all forest sites displayed frequent departures from air temperature, particularly during clear sky conditions, with elevated canopy temperatures during the day and depressed canopy temperatures at night compared to air temperature. Comparison of canopy temperatures to fluxes of carbon dioxide, water vapor, and energy reveals stronger relationships than those found with air temperature. Daytime growing season net ecosystem exchange at the pine forest site is better explained by canopy temperature (r2 = 0.61) than air temperature (r2 = 0.52). At the semi-deciduous tropical forest, canopy photosynthesis is highly correlated with canopy temperature (r2 = 0.51), with a distinct optimum temperature for photosynthesis ( 31 °C) that agrees with leaf-level measurements. During the peak of one heat wave at an old-growth temperate rainforest, hourly averaged air temperature exceeded 35 °C, 10 °C above average. Peak hourly canopy temperature approached 40 °C, and leaf-to-air vapor pressure deficit exceeded 6 kPa. These extreme

  17. Surface flux density distribution characteristics of bulk high-T c superconductor in external magnetic field

    International Nuclear Information System (INIS)

    Nishikawa, H.; Torii, S.; Yuasa, K.

    2005-01-01

    This paper describes the measured results of the two-dimensional flux density distribution of a YBCO bulk under applied AC magnetic fields with various frequency. Melt-processed oxide superconductors have been developed in order to obtain strong pinning forces. Various electric mechanical systems or magnetic levitation systems use those superconductors. The major problem is that cracks occur because the bulk superconductors are brittle. The bulk may break in magnetizing process after cracks make superconducting state instable. The trapped flux density and the permanent current characteristics of bulk superconductors have been analyzed, so as to examine the magnetizing processes or superconducting states of the bulk. In those studies, the two-dimensional surface flux density distributions of the bulk in static fields are discussed. On the other hand, the distributions in dynamic fields are little discussed. We attempted to examine the states of the bulk in the dynamic fields, and made a unique experimental device which has movable sensors synchronized with AC applied fields. As a result, the two-dimensional distributions in the dynamic fields are acquired by recombining the one-dimensional distributions. The dynamic states of the flux of the bulk and the influences of directions of cracks are observed from the distributions. In addition, a new method for measuring two-dimensional flux density distribution under dynamic magnetic fields is suggested

  18. Investigating the impact of uneven magnetic flux density distribution on core loss estimation

    DEFF Research Database (Denmark)

    Niroumand, Farideh Javidi; Nymand, Morten; Wang, Yiren

    2017-01-01

    . The presented work in this paper has been carried out for two common excitation waveforms in power electronics applications, sinusoid and square-wave and for two different core shapes, toroid and E-cores. Results show that ±10% discrepancy should be expected in loss estimation of the core using effective...... is calculated according to an effective flux density value and the macroscopic dimensions of the cores. However, the flux distribution in the core can alter by core shapes and/or operating conditions due to nonlinear material properties. This paper studies the element-wise estimation of the loss in magnetic...... cores. FEM has been used to investigate the flux density distribution in the core and the loss has been estimated considering this distribution. Finally, comparative results are shown between the classical macroscopic core loss estimation using effective dimensions and the element-wise loss estimation...

  19. Estimation of electrical conductivity distribution within the human head from magnetic flux density measurement

    Science.gov (United States)

    Gao, Nuo; Zhu, S. A.; He, Bin

    2005-06-01

    We have developed a new algorithm for magnetic resonance electrical impedance tomography (MREIT), which uses only one component of the magnetic flux density to reconstruct the electrical conductivity distribution within the body. The radial basis function (RBF) network and simplex method are used in the present approach to estimate the conductivity distribution by minimizing the errors between the 'measured' and model-predicted magnetic flux densities. Computer simulations were conducted in a realistic-geometry head model to test the feasibility of the proposed approach. Single-variable and three-variable simulations were performed to estimate the brain-skull conductivity ratio and the conductivity values of the brain, skull and scalp layers. When SNR = 15 for magnetic flux density measurements with the target skull-to-brain conductivity ratio being 1/15, the relative error (RE) between the target and estimated conductivity was 0.0737 ± 0.0746 in the single-variable simulations. In the three-variable simulations, the RE was 0.1676 ± 0.0317. Effects of electrode position uncertainty were also assessed by computer simulations. The present promising results suggest the feasibility of estimating important conductivity values within the head from noninvasive magnetic flux density measurements.

  20. Black hole kinematics: The "in"-vacuum energy density and flux for different observers

    Science.gov (United States)

    Singh, Suprit; Chakraborty, Sumanta

    2014-07-01

    We have investigated the local invariant scalar observables—energy density and flux—which explicitly depend on the kinematics of the concerned observers in the thin null shell gravitational collapse geometry. The use of globally defined null coordinates allows for the definition of a unique in-vacuum for the scalar field propagating in this background. Computing the stress-energy tensor for this scalar field, we work out the energy density and flux for the static observers outside the horizon and then consider the radially in-falling observers who fall in from some specified initial radius all the way through the horizon and inside to the eventual singularity. Our results confirm the thermal Tolman-shifted energy density and fluxes for the static observers which diverge at the horizon. For the in-falling observer starting from far off, both the quantities—energy density and flux—at the horizon crossing are regular and finite. For example, the flux at the horizon for the in-falling observer from infinity is approximately 24 times the flux for the observer at infinity. Compared with the static observers in the near-horizon region, this is quite small. Both the quantities grow as the in-fall progresses inside the horizon and diverge at the singularity.

  1. Relic entropy generation, and relic gravitons as a consequence of energy density and energy flux density as derived from GR

    International Nuclear Information System (INIS)

    Beckwith, A W

    2008-01-01

    First of all, we outline a well known result. I.e. the formation of energy density and energy flux density for de Sitter space time, assuming close to mono chromatic close to plane wave generation of spin two gravitons. This is done in the context of an emergent vacuum energy field being introduced at the onset of the initial space time singularity. We reference entropy generation by multiple brane- anti brane combinations leading to an initial soliton-instanton formation. We close then with observations we think are pertinent to entropy increase and also the variation of statistical noise about the CMBR spectra. This ties in with possible new species of detectable 'neutrinos' in ways which lead to an extension of the standard model, and ties in with possible spin two graviton generation of both entropy and structure formation initially, in accordance with a starting point for our analysis of inflation being due to emergent field energy density from a prior universe.

  2. Practical difficulties in determining 222Rn flux density in underground uranium mines

    International Nuclear Information System (INIS)

    Bigu, J.

    1991-01-01

    Radon-222 flux density, J, has been determined in a number of locations in an underground U mine. Measurements were conducted using the Two-Point Measurement (2PM) method, consisting of measuring the 222Rn concentration at two different points a distance apart within a given section of the mine. Several mine models were used for determining J by the above method. The 2PM method is sensitive to sources and sinks of 222Rn other than mine walls, as well as mining operations and mining activities of a diverse nature, and to local variations in airflow conditions. Because of this, J obtained by the 2PM method represents an 'apparent' flux density. Significant differences were found in the flux density calculated according to different mine models. In addition, J measurements using the flux 'can' method were also carried out in mine walls and compared with the values obtained by the 2PM method. Wide discrepancies between the two methods were found. The practical and theoretical difficulties in determining J are discussed

  3. Relationships of a growing magnetic flux region to flares

    NARCIS (Netherlands)

    Schadee, A.; Martin, S.F.; Bentley, R.D.; Antalova, A.; Kucera, A.; Dezs, L.; Gesztelyi, L.; Harvey, K.L.; Jones, H.; Livi, S.H.B.; Wang, J.

    1984-01-01

    Some sites for solar flares are known to develop where new magnetic flux emerges and becomes abutted against opposite polarity pre-existing magnetic flux (review by Galzauskas/1/). We have identified and analyzed the evolution of such flare sites at the boundaries of a major new and growing magnetic

  4. Optimization of multiply acquired magnetic flux density Bz using ICNE-Multiecho train in MREIT

    Science.gov (United States)

    Nam, Hyun Soo; In Kwon, Oh

    2010-05-01

    The aim of magnetic resonance electrical impedance tomography (MREIT) is to visualize the electrical properties, conductivity or current density of an object by injection of current. Recently, the prolonged data acquisition time when using the injected current nonlinear encoding (ICNE) method has been advantageous for measurement of magnetic flux density data, Bz, for MREIT in the signal-to-noise ratio (SNR). However, the ICNE method results in undesirable side artifacts, such as blurring, chemical shift and phase artifacts, due to the long data acquisition under an inhomogeneous static field. In this paper, we apply the ICNE method to a gradient and spin echo (GRASE) multi-echo train pulse sequence in order to provide the multiple k-space lines during a single RF pulse period. We analyze the SNR of the measured multiple Bz data using the proposed ICNE-Multiecho MR pulse sequence. By determining a weighting factor for Bz data in each of the echoes, an optimized inversion formula for the magnetic flux density data is proposed for the ICNE-Multiecho MR sequence. Using the ICNE-Multiecho method, the quality of the measured magnetic flux density is considerably increased by the injection of a long current through the echo train length and by optimization of the voxel-by-voxel noise level of the Bz value. Agarose-gel phantom experiments have demonstrated fewer artifacts and a better SNR using the ICNE-Multiecho method. Experimenting with the brain of an anesthetized dog, we collected valuable echoes by taking into account the noise level of each of the echoes and determined Bz data by determining optimized weighting factors for the multiply acquired magnetic flux density data.

  5. Geometrical Relationship Between Interplanetary Flux Ropes and Their Solar Sources

    Science.gov (United States)

    Marubashi, K.; Akiyama, S.; Yashiro, S.; Gopalswamy, N.; Cho, K.-S.; Park, Y.-D.

    2015-05-01

    We investigated the physical connection between interplanetary flux ropes (IFRs) near Earth and coronal mass ejections (CMEs) by comparing the magnetic field structures of IFRs and CME source regions. The analysis is based on the list of 54 pairs of ICMEs (interplanetary coronal mass ejections) and CMEs that are taken to be the most probable solar source events. We first attempted to identify the flux rope structure in each of the 54 ICMEs by fitting models with a cylinder and torus magnetic field geometry, both with a force-free field structure. This analysis determined the possible geometries of the identified flux ropes. Then we compared the flux rope geometries with the magnetic field structure of the solar source regions. We obtained the following results: (1) Flux rope structures are seen in 51 ICMEs out of the 54. The result implies that all ICMEs have an intrinsic flux rope structure, if the three exceptional cases are attributed to unfavorable observation conditions. (2) It is possible to find flux rope geometries with the main axis orientation close to the orientation of the magnetic polarity inversion line (PIL) in the solar source regions, the differences being less than 25°. (3) The helicity sign of an IFR is strongly controlled by the location of the solar source: flux ropes with positive (negative) helicity are associated with sources in the southern (northern) hemisphere (six exceptions were found). (4) Over two-thirds of the sources in the northern hemisphere are concentrated along PILs with orientations of 45° ± 30° (measured clockwise from the east), and over two-thirds in the southern hemisphere along PILs with orientations of 135° ± 30°, both corresponding to the Hale boundaries. These results strongly support the idea that a flux rope with the main axis parallel to the PIL erupts in a CME and that the erupted flux rope propagates through the interplanetary space with its orientation maintained and is observed as an IFR.

  6. Relation between the ion flux and plasma density in an rf CCP discharge

    Science.gov (United States)

    Bogdanova, Maria; Lopaev, Dmitry; Zyryanov, Sergey; Voloshin, Dmitry; Rakhimova, Tatyana

    2018-02-01

    Ion flux and plasma density are some of the most essential parameters for plasma-assisted process control. There is also a simple and well-known relation between them based on the Bohm criterion. This relation allows the avoidance of directly measuring both the ion flux and the plasma density simultaneously, but the question is, how accurate this estimation would be. This work represents the study of the sensitivity of the relation to plasma conditions, such as gas pressure, type of gas and plasma density. The experiments are carried out in an asymmetric rf dual-frequency CCP discharge in noble gases—Ar and Xe—and in molecular gas—N2. The gas pressure is varied from 20 mTorr up to 200 mTorr and the plasma density range is 109 to 5.6 × 1010 cm‑3. Analysis of the experimental data is made by using the 2D PIC MCC model of the ion current collection by a planar electrode. The results show that there is some sensitivity of the relation to the type of gas and pressure, but the dependence of the relation on plasma density turns out to be slight. Therefore, the pressure parameterization of the relation for a certain gas can be used to establish plasma density by measuring ion current to an electrode and vice versa.

  7. Development of an Axial Flux MEMS BLDC Micromotor with Increased Efficiency and Power Density

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ding

    2015-06-01

    Full Text Available This paper presents a rigorous design and optimization of an axial flux microelectromechanical systems (MEMS brushless dc (BLDC micromotor with dual rotor improving both efficiency and power density with an external diameter of only around 10 mm. The stator is made of two layers of windings by MEMS technology. The rotor is developed by film permanent magnets assembled over the rotor yoke. The characteristics of the MEMS micromotor are analyzed and modeled through a 3-D magnetic equivalent circuit (MEC taking the leakage flux and fringing effect into account. Such a model yields a relatively accurate prediction of the flux in the air gap, back electromotive force (EMF and electromagnetic torque, whilst being computationally efficient. Based on 3-D MEC model the multi-objective firefly algorithm (MOFA is developed for the optimal design of this special machine. Both 3-D finite element (FE simulation and experiments are employed to validate the MEC model and MOFA optimization design.

  8. Aruscular mycorhizal fungi alter plant allometry and biomass - density relationships

    DEFF Research Database (Denmark)

    Zhang, Qian; Zhang, Lu; Weiner, Jacob

    2011-01-01

    Background and Aims Plant biomass–density relationships during self-thinning are determined mainly by allometry. Both allometry and biomass–density relationship have been shown to vary with abiotic conditions, but the effects of biotic interactions have not been investigated. Arbuscular mycorrhizal...... mycorrhizal levels were obtained by applying benomyl (low AMF) or not (high AMF). Experiment 1 investigated the effects of AMF on plant growth in the absence of competition. Experiment 2 was a factorial design with two mycorrhizal levels and two plant densities (6000 and 17 500 seeds m-2). Shoot biomass, root....... In self-thinning populations, the slope of the log (mean shoot biomass) vs. log density relationship was significantly steeper for the high AMF treatment (slope = –1·480) than for the low AMF treatment (–1·133). The canopy radius–biomass allometric exponents were not significantly affected by AMF level...

  9. Installation for the study of heat transfer with high flux density

    International Nuclear Information System (INIS)

    Robin, M.; Schwab, B.

    1957-01-01

    As a result of their very low vapor pressure, metals with a low fusion point (sodium, sodium-potassium alloys, etc.) can be used at high temperature, as heating fluids, in installations whose internal pressure is close to atmospheric pressure. Owing to the very high convection coefficients which can be reached with these fluids and to the large temperature differences utilizable, it is possible to produce through the exchange surfaces considerable heat flux densities, of the order of those which exist through the canning of fuel elements in nuclear reactors. The installation described allowed a flux density of more than 200 W/cm 2 to be obtained, the heating fluid being a Na-K alloy (containing 56 per cent by weight of potassium) brought to a temperature around 550 deg. C. (author) [fr

  10. Spatial and temporal variations in sap flux density in Japanese cedar (Cryptomeria japonica) trees, central Taiwan

    Science.gov (United States)

    Tseng, Han; Chiu, Chen-Wei; Wey, Tsong-Huei; Kume, Tomonori

    2013-04-01

    Sap flow measurement method is a technique widely used for measuring forest transpiration. However, variations in sap flow distribution can make accurately estimating individual tree-scale transpiration difficult. Significant spatial variations in sap flow across the sapwood within tree have been reported in many studies. In contrast, few studies have discussed azimuthal variations in sap flow, and even fewer have examined their seasonal change characteristics. This study was undertaken to clarify within-tree special and temporal variations in sap flow, and to propose an appropriate design for individual-tree scale transpiration estimates for Japanese cedar trees. The measurement was conducted in a Japanese cedar plantation located in Central Taiwan. Spatial distribution of sap flux density through the sapwood cross-section was measured using Granier's thermal dissipation technique. Sensors were installed at 1.3 m high on the east, west, north and south sides of the stem at 0-2 cm in 8 trees, and at 2-4 cm in the 6 larger trees. We found, in radial profile analysis, that sap flux densities measured at the depth of 2-4 cm were 50 % in average of those measured at depth of 0-2 cm. In azimuthal profile analysis, we found significant azimuthal variations in sap flux density. In one individual tree, the ratio of sap flux density on one aspect to another could be approximately 40-190 %, with no dependency on directions. Both radial and azimuthal profiles in most sample trees were fairly consistent throughout the measurement period. We concluded that radial and azimuthal variations in sap flow across sapwood might introduce significant errors in individual tree-scale transpiration estimations based on single point sap flow measurement, and seasonal change of within-tree spatial variations in sap flow could have insignificant impacts on accuracy of long-term individual tree-scale transpiration estimates. Keywords: transpiration, sap flow measurement, scaling up, sap flow

  11. Measurement of current density fluctuations and ambipolar particle flux due to magnetic fluctuations in MST

    International Nuclear Information System (INIS)

    Shen, Weimin.

    1992-08-01

    Studies of magnetic fluctuation induced particle transport on Reversed Field Pinch plasmas were done on the Madison Symmetric Torus. Plasma current density and current density fluctuations were measured using a multi-coil magnetic probes. The low frequency (f parallel B r >. The result of zero net charged particle loss was obtained, meaning the flux is ambipolar. The ambipolarity of low frequency global tearing modes is satisfied through the phase relations determined by tearing instabilities. The ambipolarity of high frequency localized modes could be partially explained by the simple model of Waltz based on the radial average of small scale turbulence

  12. Magnetic-field flux density and spectral characteristics of motor-driven personal appliances.

    Science.gov (United States)

    Wilson, B W; Hansen, N H; Davis, K C

    1994-01-01

    Flux density and spectral measurements were carried out on magnetic fields generated by several types of motor-driven personal appliances used near the body. Among the units tested were several for which the average flux densities, as determined at the surfaces of the appliance, exceeded 0.4 mT. Time-rates-of-change (dB/dt) for several units exceeded 1000 T/s, and several units exhibited high-frequency components in the low-MHz range. Use of such appliances, although normally of short duration, can represent exposure to magnetic fields of relatively high flux density, which may also have high-frequency components. Compared to other household and commercial sources of magnetic fields, those generated by certain motor-driven personal appliances may represent a significant contribution to time-weighted average exposure and may represent an important source of local induced currents in the body. Furthermore, high-frequency transients that represent only a minor contribution to time-weighted average exposure may generate significant instantaneous induced currents.

  13. Anomalous B-H behaviour of electrical steels at very low flux density

    Energy Technology Data Exchange (ETDEWEB)

    Zurek, Stan [Wolfson Centre for Magnetics, School of Engineering, Cardiff University, Cardiff CF24 3AA (United Kingdom)], E-mail: ZurekS@cardiff.ac.uk; Al-Naemi, Faris; Moses, Anthony J.; Marketos, Philip [Wolfson Centre for Magnetics, School of Engineering, Cardiff University, Cardiff CF24 3AA (United Kingdom)

    2008-10-15

    The behaviour of ferromagnetic materials under very low magnetic field was investigated more than a century ago by Lord Rayleigh. However, it has been shown since that the so-called Rayleigh law fails for very low magnetic fields, although the explanation for this phenomenon was not given. An anomalous B-H behaviour at very low alternating peak flux density in conventional grain-oriented (GO) and non-oriented (NO) electrical steels is reported. It has been found that the initial permeability is constant for all the measured frequencies (from 20 to 400 Hz) at peak flux density below 0.1 mT, and in this region the magnetisation is almost reversible (for both GO and NO). At higher flux density the B-H loops become visibly irreversible, with a relatively narrow (for GO) or very wide (for NO) transition region. For GO the B-H loop becomes visibly 'distorted' for all frequencies at around 2 mT. The eddy current loss calculated from the so-called 'classical' equation gives values higher than the measured total losses at lower frequencies. Both these measured results are difficult to explain.

  14. Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Greg J. Shott, Vefa Yucel, Lloyd Desotell

    2007-06-01

    Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When the Rn-222 effective diffusion coefficient was estimated using five different published predictive models, the radon flux density models were found to be most sensitive to the effective diffusion coefficient model selected, the emanation coefficient, and the radionuclide inventory. Using a site-specific measured effective diffusion coefficient significantly reduced the output uncertainty. When a site-specific effective-diffusion coefficient was used, the models were most sensitive to the emanation coefficient and the radionuclide inventory.

  15. Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

    International Nuclear Information System (INIS)

    Greg J. Shott, Vefa Yucel, Lloyd Desotell Non-Nstec Authors: G. Pyles and Jon Carilli

    2007-01-01

    Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When the Rn-222 effective diffusion coefficient was estimated using five different published predictive models, the radon flux density models were found to be most sensitive to the effective diffusion coefficient model selected, the emanation coefficient, and the radionuclide inventory. Using a site-specific measured effective diffusion coefficient significantly reduced the output uncertainty. When a site-specific effective-diffusion coefficient was used, the models were most sensitive to the emanation coefficient and the radionuclide inventory

  16. Anomalous B-H behaviour of electrical steels at very low flux density

    International Nuclear Information System (INIS)

    Zurek, Stan; Al-Naemi, Faris; Moses, Anthony J.; Marketos, Philip

    2008-01-01

    The behaviour of ferromagnetic materials under very low magnetic field was investigated more than a century ago by Lord Rayleigh. However, it has been shown since that the so-called Rayleigh law fails for very low magnetic fields, although the explanation for this phenomenon was not given. An anomalous B-H behaviour at very low alternating peak flux density in conventional grain-oriented (GO) and non-oriented (NO) electrical steels is reported. It has been found that the initial permeability is constant for all the measured frequencies (from 20 to 400 Hz) at peak flux density below 0.1 mT, and in this region the magnetisation is almost reversible (for both GO and NO). At higher flux density the B-H loops become visibly irreversible, with a relatively narrow (for GO) or very wide (for NO) transition region. For GO the B-H loop becomes visibly 'distorted' for all frequencies at around 2 mT. The eddy current loss calculated from the so-called 'classical' equation gives values higher than the measured total losses at lower frequencies. Both these measured results are difficult to explain

  17. Long-term Longitudinal Recurrences of the Open Magnetic Flux Density in the Heliosphere

    Energy Technology Data Exchange (ETDEWEB)

    Dósa, M.; Erdős, G., E-mail: dosa.melinda@wigner.mta.hu [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1121 Budapest, Konkoly-Thege Miklós st 29-33 (Hungary)

    2017-04-01

    Open magnetic flux in the heliosphere is determined from the radial component of the magnetic field vector measured onboard interplanetary space probes. Previous Ulysses research has shown remarkable independence of the flux density from heliographic latitude, explained by super-radial expansion of plasma. Here we are investigating whether any longitudinal variation exists in the 50 year long OMNI magnetic data set. The heliographic longitude of origin of the plasma package was determined by applying a correction according to the solar wind travel time. Significant recurrent enhancements of the magnetic flux density were observed throughout solar cycle 23, lasting for several years. Similar, long-lasting recurring features were observed in the solar wind velocity, temperature and the deviation angle of the solar wind velocity vector from the radial direction. Each of the recurrent features has a recurrence period slightly differing from the Carrington rotation rate, although they show a common trend in time. Examining the coronal temperature data of ACE leads to the possible explanation that these long-term structures are caused by slow–fast solar wind interaction regions. A comparison with MESSENGER data measured at 0.5 au shows that these longitudinal magnetic modulations do not exist closer to the Sun, but are the result of propagation.

  18. Relationship between sex hormone levels, bone mineral density ...

    African Journals Online (AJOL)

    Introduction: Gonadal steroid hormones play a crucial role during skeletal growth and maturation in both men and women. The aim of this study is to evaluate the relationship of sex hormone levels, bone mineral density and biochemical markers of bone turnover in healthy Moroccan men. Methods: 142 Moroccan men who ...

  19. Organic carbon organic matter and bulk density relationships in arid ...

    African Journals Online (AJOL)

    Soil organic matter (SOM) and soil organic carbon (SOC) constitute usually a small portion of soil, but they are one of the most important components of ecosystems. Bulk density (dB or BD) value is necessary to convert organic carbon (OC) content per unit area. Relationships between SOM, SOC and BD were established ...

  20. Derivation of ozone flux-yield relationships for lettuce: A key horticultural crop

    International Nuclear Information System (INIS)

    Goumenaki, Eleni; Fernandez, Ignacio Gonzalez; Papanikolaou, Antigoni; Papadopoulou, Despoina; Askianakis, Christos; Kouvarakis, George; Barnes, Jeremy

    2007-01-01

    Ozone flux-response relationships were derived for lettuce, employing a multiplicative approach to model the manner in which stomatal conductance is influenced by key environmental variables, using a dataset collected during field experimentation in Crete and yield-response relationships derived from parallel open-top chamber experiments. Regional agronomic practices were adopted throughout. Computed versus measured data revealed that the derived model explained 51% (P -2 s -1 . Regressions employing very low or zero flux thresholds resulted in the strongest yield-flux relationships (explaining ∼80% (P < 0.05) of the variation in the dataset). - Establishment of ozone flux-yield relationships for a commercially-important horticultural crop grown widely in the Mediterranean

  1. A reference system for the measurement of low-strength magnetic flux density

    International Nuclear Information System (INIS)

    Fiorillo, F.; Durin, G.F.; Rocchino, L.

    2006-01-01

    Magnetic flux density standards traceable to the SI units have been developed at IEN-INRIM, by which dissemination for general measurement and testing activities can be pursued. The reference system covers a range of values extending from μ 0 H∼1T to μ 0 H∼10μT and is centered on the use of NMR magnetometers, calibrated coils, and stable current sources. The relative measuring uncertainty of the system is shown to increases with decreasing the field strength value and it is estimated to range between a few 10 -6 and some 10 -3

  2. Effect of magnetic flux-densities of up to 0.1 Tesla on copper electrodeposition

    International Nuclear Information System (INIS)

    Cifuentes, L.; Artigas, M.; Riveros, G.; Warczok, A.

    2003-01-01

    The effect of magnetic flux densities (B) between 0.0 and 0.1 Tesla on cathode and anode over potentials, cell voltage and electro deposit quality was determined fro a lab-scale copper electrowinning cell which operates at industrial current, density values. Cell voltage decreases with increasing B. The cathodic overpotential decreases by 30% when B increases from 0.0 to 0.1 T. The anodic overpotential also decreases with increasing B, but this effect is six times less than the corresponding effect on the cathodic overpotential. Cathodic effects can be predicted by an expression derived from electrochemical kinetics and magnetohydrodynamic theory. Anodic effects cannot be predicted in the same way. The size of grains and intergranular voids decreases and the surface of the electro deposit becomes smoother as B increases, which means that, in the studied conditions, the quality of the produced copper deposits improves. (Author) 26 refs

  3. Electron temperature and density relationships in coronal mass ejections

    Science.gov (United States)

    Hammond, C. M.; Phillips, J. L.; Balogh, A.

    1995-01-01

    We examine 10 coronal mass ejections from the in-ecliptic portion of the Ulysses mission. Five of these CMEs are magnetic clouds. In each case we observe an inverse relationship between electron temperature and density. For protons this relationship is less clear. Earlier work has shown a similar inverse relationship for electrons inside magnetic clouds and interpreted it to mean that the polytropic index governing the expansion of electrons is less than unity. This requires electrons to be heated as the CME expands. We offer an alternative view that the inverse relationship between electron temperature and density is caused by more rapid cooling of the denser plasma through collisions. More rapid cooling of denser plasma has been shown for 1 AU measurements in the solar wind. As evidence for this hypothesis we show that the denser plasma inside the CMEs tends to be more isotropic indicating a different history of collisions for the dense plasma. Thus, although the electron temperature inside CMEs consistently shows an inverse correlation with the density, this is not an indication of the polytropic index of the plasma but instead supports the idea of collisional modification of the electrons during their transit from the sun.

  4. The 30 cm radio flux as a solar proxy for thermosphere density modelling

    Directory of Open Access Journals (Sweden)

    Dudok de Wit Thierry

    2017-01-01

    Full Text Available The 10.7 cm radio flux (F10.7 is widely used as a proxy for solar UV forcing of the upper atmosphere. However, radio emissions at other centimetric wavelengths have been routinely monitored since the 1950 s, thereby offering prospects for building proxies that may be better tailored to space weather needs. Here we advocate the 30 cm flux (F30 as a proxy that is more sensitive than F10.7 to longer wavelengths in the UV and show that it improves the response of the thermospheric density to solar forcing, as modelled with DTM (Drag Temperature Model. In particular, the model bias drops on average by 0–20% when replacing F10.7 by F30; it is also more stable (the standard deviation of the bias is 15–40% smaller and the density variation at the the solar rotation period is reproduced with a 35–50% smaller error. We compare F30 to other solar proxies and discuss its assets and limitations.

  5. Microsystem for remote sensing of high energy radiation with associated extremely low photon flux densities

    Science.gov (United States)

    Otten, A.; Jain, V. K.

    2015-08-01

    This paper presents a microsystem for remote sensing of high energy radiation in extremely low flux density conditions. With wide deployment in mind, potential applications range from nuclear non-proliferation, to hospital radiation-safety. The daunting challenge is the low level of photon flux densities - emerging from a Scintillation Crystal (SC) on to a ~1 mm-square detector, which are a factor of 10000 or so lower than those acceptable to recently reported photonic chips (including `single-photon detection' chips), due to a combination of low Lux, small detector size, and short duration SC output pulses - on the order of 1 μs. These challenges are attempted to be overcome by the design of an innovative `System on a Chip' type microchip, with high detector sensitivity, and effective coupling from the SC to the photodetector. The microchip houses a tiny n+ diff p-epi photodiode (PD) as well as the associated analog amplification and other related circuitry, all fabricated in 0.5micron, 3-metal 2-poly CMOS technology. The amplification, together with pulse-shaping of the photocurrent-induced voltage signal, is achieved through a tandem of two capacitively coupled, double-cascode amplifiers. Included in the paper are theoretical estimates and experimental results.

  6. The Pressure and Magnetic Flux Density Analysis of Helical-Type DC Electromagnetic Pump

    International Nuclear Information System (INIS)

    Lee, Geun Hyeong; Kim, Hee Reyoung

    2016-01-01

    The developed pressure was made by only electromagnetic force eliminating probability of impurities contact, therefore the high reactivity materials such as alkali were best match to electromagnetic pump. The heavy ion accelerator facility by Rare Isotope Science Project (RISP) in Korea is trying to construct accelerator using liquid lithium for high efficiency of acceleration by decreasing charge state. The helical-type DC electromagnetic pump was employed to make a charge stripper that decrease charge state of heavy ion. The specification of electromagnetic pump was developed pressure of 15 bar with flowrate of 6 cc/s in the condition of 200℃. The pressure of DC electromagnetic pump was analyzed in the aspects of current and number of duct turns. The developed pressure was almost proportional to input current because relatively low flowrate made negligible of the electromotive force and hydraulic pressure drop. The pressure and magnetic flux density of helical-type DC electromagnetic pump were analyzed. The pressure was proportion to input current and number of duct turns, and magnetic flux density was higher when ferromagnet was applied at electromagnetic pump. It seems that number of duct turns could be increase and ferromagnet could be applied in order to increase pressure of DC electromagnetic pump with constant input current

  7. Dietary niche variation and its relationship to lizard population density.

    Science.gov (United States)

    Novosolov, Maria; Rodda, Gordon H; Gainsbury, Alison M; Meiri, Shai

    2018-01-01

    Insular species are predicted to broaden their niches, in response to having fewer competitors. They can thus exploit a greater proportion of the resource spectrum. In turn, broader niches are hypothesized to facilitate (or be a consequence of) increased population densities. We tested whether insular lizards have broader dietary niches than mainland species, how it relates to competitor and predator richness, and the nature of the relationship between population density and dietary niche breadth. We collected population density and dietary niche breadth data for 36 insular and 59 mainland lizard species, and estimated competitor and predator richness at the localities where diet data were collected. We estimated dietary niche shift by comparing island species to their mainland relatives. We controlled for phylogenetic relatedness, body mass and the size of the plots over which densities were estimated. We found that island and mainland species had similar niche breadths. Dietary niche breadth was unrelated to competitor and predator richness, on both islands and the mainland. Population density was unrelated to dietary niche breadth across island and mainland populations. Our results indicate that dietary generalism is not an effective way of increasing population density nor is it result of lower competitive pressure. A lower variety of resources on islands may prevent insular animals from increasing their niche breadths even in the face of few competitors. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  8. New flux based dose–response relationships for ozone for European forest tree species

    International Nuclear Information System (INIS)

    Büker, P.; Feng, Z.; Uddling, J.; Briolat, A.; Alonso, R.; Braun, S.; Elvira, S.; Gerosa, G.; Karlsson, P.E.; Le Thiec, D.

    2015-01-01

    To derive O 3 dose–response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O 3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O 3 flux concept and represents a step forward in predicting O 3 damage to forests in a spatially and temporally varying climate. - Highlights: • We present new ozone flux based dose–response relationships for European trees. • The model-based study accounted for the soil water effect on stomatal flux. • Different statistically derived ozone flux thresholds were applied. • Climate region specific parameterisation often outperformed simplified parameterisation. • Findings could help redefining critical levels for ozone effects on trees. - New stomatal flux based ozone dose–response relationships for tree species are derived for the regional risk assessment of ozone effects on European forest ecosystems.

  9. Planetary cores, their energy flux relationship, and its implications

    Science.gov (United States)

    Johnson, Fred M.

    2018-02-01

    Integrated surface heat flux data from each planet in our solar system plus over 50 stars, including our Sun, was plotted against each object's known mass to generate a continuous exponential curve at an R-squared value of 0.99. The unexpected yet undeniable implication of this study is that all planets and celestial objects have a similar mode of energy production. It is widely accepted that proton-proton reactions require hydrogen gas at temperatures of about 15 million degrees, neither of which can plausibly exist inside a terrestrial planet. Hence, this paper proposes a nuclear fission mechanism for all luminous celestial objects, and uses this mechanism to further suggest a developmental narrative for all celestial bodies, including our Sun. This narrative was deduced from an exponential curve drawn adjacent to the first and passing through the Earth's solid core (as a known prototype). This trend line was used to predict the core masses for each planet as a function of its luminosity.

  10. A study of influence of material properties on magnetic flux density induced in magneto rheological damper through finite element analysis

    Directory of Open Access Journals (Sweden)

    Gurubasavaraju T. M.

    2018-01-01

    Full Text Available Magnetorheological fluids are smart materials, which are responsive to the external stimulus and changes their rheological properties. The damper performance (damping force is dependent on the magnetic flux density induced at the annular gap. Magnetic flux density developed at fluid flow gap of MR damper due to external applied current is also dependent on materials properties of components of MR damper (such as piston head, outer cylinder and piston rod. The present paper discus about the influence of different materials selected for components of the MR damper on magnetic effect using magnetostatic analysis. Different materials such as magnetic and low carbon steels are considered for piston head of the MR damper and magnetic flux density induced at fluid flow gap (filled with MR fluid is computed for different DC current applied to the electromagnetic coil. Developed magnetic flux is used for calculating the damper force using analytical method for each case. The low carbon steel has higher magnetic permeability hence maximum magnetic flux could pass through the piston head, which leads to higher value of magnetic effect induction at the annular gap. From the analysis results it is observed that the magnetic steel and low carbon steel piston head provided maximum magnetic flux density. Eventually the higher damping force can be observed for same case.

  11. Flux

    DEFF Research Database (Denmark)

    Ravn, Ib

    . FLUX betegner en flyden eller strømmen, dvs. dynamik. Forstår man livet som proces og udvikling i stedet for som ting og mekanik, får man et andet billede af det gode liv end det, som den velkendte vestlige mekanicisme lægger op til. Dynamisk forstået indebærer det gode liv den bedst mulige...... kanalisering af den flux eller energi, der strømmer igennem os og giver sig til kende i vore daglige aktiviteter. Skal vores tanker, handlinger, arbejde, samvær og politiske liv organiseres efter stramme og faste regelsæt, uden slinger i valsen? Eller skal de tværtimod forløbe ganske uhindret af regler og bånd...

  12. Design of PCB search coils for AC magnetic flux density measurement

    Science.gov (United States)

    Ulvr, Michal

    2018-04-01

    This paper presents single-layer, double-layer and ten-layer planar square search coils designed for AC magnetic flux density amplitude measurement up to 1 T in the low frequency range in a 10 mm air gap. The printed-circuit-board (PCB) method was used for producing the search coils. Special attention is given to a full characterization of the PCB search coils including a comparison between the detailed analytical design method and the finite integration technique method (FIT) on the one hand, and experimental results on the other. The results show very good agreement in the resistance, inductance and search coil constant values (the area turns) and also in the frequency dependence of the search coil constant.

  13. Frequency spectra from current vs. magnetic flux density measurements for mobile phones and other electrical appliances.

    Science.gov (United States)

    Straume, Aksel; Johnsson, Anders; Oftedal, Gunnhild; Wilén, Jonna

    2007-10-01

    The frequency spectra of electromagnetic fields have to be determined to evaluate human exposure in accordance to ICNIRP guidelines. In the literature, comparisons with magnetic field guidelines have been performed by using the frequency distribution of the current drawn from the battery. In the present study we compared the frequency spectrum in the range 217 Hz to 2.4 kHz of the magnetic flux density measured near the surface of a mobile phone with the frequency spectrum of the supply current. By using the multiple frequency rule, recommended in the ICNIRP guidelines, we estimated the magnetic field exposure in the two cases. Similar measurements and estimations were done for an electric drill, a hair dryer, and a fluorescent desk lamp. All the devices have a basic frequency of 50 Hz, and the frequency spectra were evaluated up to 550 Hz. We also mapped the magnetic field in 3D around three mobile phones. The frequency distributions obtained from the two measurement methods are not equal. The frequency content of the current leads to an overestimation of the magnetic field exposure by a factor up to 2.2 for the mobile phone. For the drill, the hair dryer, and the fluorescent lamp, the supply current signal underestimated the exposure by a factor up to 2.3. In conclusion, an accurate exposure evaluation requires the magnetic flux density spectrum of the device to be measured directly. There was no indication that the devices studied would exceed the reference levels at the working distances normally used.

  14. The Relationship Between Osteoporotic Risk Factors and Bone Mineral Density

    Directory of Open Access Journals (Sweden)

    Şule Şahin Onat

    2013-12-01

    Full Text Available Objective: Since osteoporosis is a preventable disease to some extent, risk factor determination and if possible modification is very important. The aim of this study is to identify the relationship between ostoporotic risk factors and bone mineral density results and emphasize the importance of risk factors. Materials and Methods: The study comprised 103 postmenopausal osteoporotic women. Demographic characteristics, osteoporortic risk factors, lumbar vertebrae and femur neck T scores were recorded. Relationships between lumbar vertebra and femur neck T scores and risk factors were statistically studied. Results: Advanced age, low physical activity status, inadequte dietary calcium intake and vertebral compression fractures were found to be associated with low bone mineral density results in postmenopausal osteoporotic women whereas marital status, occupation, education level and familial fracture history were not. Furthermore early menopause was found to be associated with low femoral T scores and smoking with low lumbar T scores. Tendency to fall and number of chronic diseases were irrelevant to bone mineral density. Conclusions: Risk factor assesment is still important for osteoporosis prevention. (Turkish Journal of Osteoporosis 2013;19:74-80

  15. Relationship between input power and power density of SMA spring

    Science.gov (United States)

    Park, Cheol Hoon; Ham, Sang Yong; Son, Young Su

    2016-04-01

    The important required characteristics of an artificial muscle for a human arm-like manipulator are high strain and high power density. From this viewpoint, an SMA (shape memory alloy) spring is a good candidate for the actuator of a robotic manipulator that utilizes an artificial muscle. In this study, the maximum power density of an SMA spring was evaluated with respect to the input power. The spring samples were fabricated from SMA wires of different diameters ranging between 0.1 and 0.3 mm. For each diameter, two types of wires with different transition temperatures were used. The relationship between the transition temperature and maximum power density was also evaluated. Each SMA spring was stretched downward by an attached weight and the temperature was increased through the application of an electric current. The displacement, velocity, and temperature of the SMA spring were measured by laser displacement sensors and a thermocouple. Based on the experimental data, it was determined that the maximum power densities of the different SMA springs ranged between 1,300 and 5,500 W/kg. This confirmed the applicability of an SMA spring to human arm-like robotic manipulators. The results of this study can be used as reference for design.

  16. Flux pinning and Critical current density in La2-xSrxCuO4+d

    Science.gov (United States)

    Mohottala, Hashini; Wells, B. O.; Budnick, J. I.; Hines, W. A.; Moodenbaugh, A. R.; Chou, F. C.

    2006-03-01

    We have studied the magnetic characteristics of the critical states in a series of samples of the type La2-xSrxCuO4+d that is doped with both Sr and excess O incorporated using electrochemistry. These samples spontaneously phase separate and show both a superconducting phase with TC near 40 K and a magnetic phase with TM near 40 K. Our previous studies established that the superconducting phase is similar to an optimally doped sample while the magnetic phase is consistent with the static spin density wave reported for x=1/8 Sr or Ba doped samples. Magnetization data at various temperatures showed large reversibility in all the samples. The critical current densities JC(0) values were at least an order of magnitude smaller than that of the reported values for YBa2Cu3O7-d and La2-xSrxCuO4. At higher fields JC(H) was smaller indicating the existence of weak flux pinning in the system. Based on our magnetization data we conclude that the vortex lattice pinning is different from non-phase separated cuprates. This work was partially supported by the US-DOE through contract DE-FG02-00ER45801 and the Cottrell Scholar Program of the Research Corporation.

  17. Relative turbulent transport efficiency and flux-variance relationships of temperature and water vapor

    Science.gov (United States)

    Hsieh, C. I.

    2016-12-01

    This study investigated the relative transport efficiency and flux-variance relationships of temperature and water vapor, and examined the performance of using this method for predicting sensible heat (H) and water vapor (LE) fluxes with eddy-covariance measured flux data at three different ecosystems: grassland, paddy rice field, and forest.The H and LE estimations were found to be in good agreement with the measurements over the three fields. The prediction accuracy of LE could be improved by around 15% if the predictions were obtained by the flux-variance method in conjunction with measured sensible heat fluxes. Moreover, the paddy rice field was found to be a special case where water vapor follows flux-variance relation better than heat does. The flux budget equations of heat and water vapor were applied to explain this phenomenon. Our results also showed that heat and water vapor were transported with the same efficiency above the grassland and rice paddy. For the forest, heat was transported 20% more efficiently than evapotranspiration.

  18. Relationships between brightness of nighttime lights and population density

    Science.gov (United States)

    Naizhuo, Z.

    2012-12-01

    Brightness of nighttime lights has been proven to be a good proxy for socioeconomic and demographic statistics. Moreover, the satellite nighttime lights data have been used to spatially disaggregate amounts of gross domestic product (GDP), fossil fuel carbon dioxide emission, and electric power consumption (Ghosh et al., 2010; Oda and Maksyutov, 2011; Zhao et al., 2012). Spatial disaggregations were performed in these previous studies based on assumed linear relationships between digital number (DN) value of pixels in the nighttime light images and socioeconomic data. However, reliability of the linear relationships was never tested due to lack of relative high-spatial-resolution (equal to or finer than 1 km × 1 km) statistical data. With the similar assumption that brightness linearly correlates to population, Bharti et al. (2011) used nighttime light data as a proxy for population density and then developed a model about seasonal fluctuations of measles in West Africa. The Oak Ridge National Laboratory used sub-national census population data and high spatial resolution remotely-sensed-images to produce LandScan population raster datasets. The LandScan population datasets have 1 km × 1 km spatial resolution which is consistent with the spatial resolution of the nighttime light images. Therefore, in this study I selected 2008 LandScan population data as baseline reference data and the contiguous United State as study area. Relationships between DN value of pixels in the 2008 Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) stable light image and population density were established. Results showed that an exponential function can more accurately reflect the relationship between luminosity and population density than a linear function. Additionally, a certain number of saturated pixels with DN value of 63 exist in urban core areas. If directly using the exponential function to estimate the population density for the whole brightly

  19. Effect of Magnetic Flux Density and Applied Current on Temperature, Velocity and Entropy Generation Distributions in MHD Pumps

    Directory of Open Access Journals (Sweden)

    M. Kiyasatfar

    2011-01-01

    Full Text Available In the present study, simulation of steady state, incompressible and fully developed laminar flow has been conducted in a magneto hydrodynamic (MHD pump. The governing equations are solved numerically by finite-difference method. The effect of the magnetic flux density and current on the flow and temperature distributions in a MHD pump is investigated. The obtained results showed that controlling the flow and the temperature is possible through the controlling of the applied current and the magnetic flux. Furthermore, the effects of the magnetic flux density and current on entropy generation in MHD pump are considered. Our presented numerical results are in good agreement with the experimental data showed in literature.

  20. A relationship between the weighted density approximation and the local-scaling transformation version of density functional theory

    International Nuclear Information System (INIS)

    Diez, Reinaldo Pis; Karasiev, Valentin V

    2003-01-01

    A relationship between the auxiliary density, ρ(r), defined within the framework of the weighted density approximation and the kinetic energy modulating factor, A N ([ρ(r)]; r), which appears in the local-scaling transformation version of density functional theory is presented. This relationship imposes the condition of positiveness on the kinetic energy modulating factor and this, in turn, leads to an important mathematical condition on any approximate kinetic energy density functional. It is shown that two well-known approximate kinetic energy density functionals do not satisfy the above relationship at distances very close to the nucleus. By forcing a given approximate kinetic energy density functional to obey the above condition, both the kinetic and exchange energies can be obtained within a framework similar to that of the weighted density approximation. Results on some closed-shell atomic systems provide support for those ideas

  1. A state-space modeling approach to estimating canopy conductance and associated uncertainties from sap flux density data

    Science.gov (United States)

    David M. Bell; Eric J. Ward; A. Christopher Oishi; Ram Oren; Paul G. Flikkema; James S. Clark; David Whitehead

    2015-01-01

    Uncertainties in ecophysiological responses to environment, such as the impact of atmospheric and soil moisture conditions on plant water regulation, limit our ability to estimate key inputs for ecosystem models. Advanced statistical frameworks provide coherent methodologies for relating observed data, such as stem sap flux density, to unobserved processes, such as...

  2. Flux density variability of 1741-038: Refractive scintillation and intrinsic variations

    Science.gov (United States)

    Qian, S. J.; Britzen, S.; Witzel, A.; Krichbaum, T. P.; Wegner, R.; Waltman, E.

    1995-03-01

    The structure functions D(tau) of the flux density variations at 2.7 GHz and 8.1 GHz in the compact radio source 1741-038 (z = 1.054) are compared with those at 1.5, 4.9, 15 and 22 GHz given by Hjellming & Narayan (1986) for a similar observing period. It is shown that for time lags 5 is less than or approximately tau is less than or approximately 30 days the structure functions at 2.7 GHz and 1.5 GHz are very similar and can be approximately represented by a power lae D(tau) varies as taup with index p approximately 1.7 - 1.8. The structure functions at 8.1, 15 and 22 GHz differ from those at the lower frequencies. A two-component model involving the extended Galactic interstellar medium and a thin screen with enhanced scattering strength is proposed. Using the refractive interstellar scintillation theory, the theoretical structure functions for the six observing frequencies are calculated. It is shown that the observed structure functions at 1.5 and 2.7 GHz can be well fitted by the model. The theoretical structure functions for the three higher frequencies (8.1, 15 and 22 GHz) are found to be much smaller than the observed structure functions. Thus the high frequency variations can not be fitted within the presently discussed RISS models and are probably intrinsic to the source.

  3. Heat flux of driven granular mixtures at low density: Stability analysis of the homogeneous steady state

    Science.gov (United States)

    Khalil, Nagi; Garzó, Vicente

    2018-02-01

    The Navier-Stokes order hydrodynamic equations for a low-density driven granular mixture obtained previously [Khalil and Garzó, Phys. Rev. E 88, 052201 (2013), 10.1103/PhysRevE.88.052201] from the Chapman-Enskog solution to the Boltzmann equation are considered further. The four transport coefficients associated with the heat flux are obtained in terms of the mass ratio, the size ratio, composition, coefficients of restitution, and the driven parameters of the model. Their quantitative variation on the control parameters of the system is demonstrated by considering the leading terms in a Sonine polynomial expansion to solve the exact integral equations. As an application of these results, the stability of the homogeneous steady state is studied. In contrast to the results obtained in undriven granular mixtures, the stability analysis of the linearized Navier-Stokes hydrodynamic equations shows that the transversal and longitudinal modes are (linearly) stable with respect to long enough wavelength excitations. This conclusion agrees with a previous analysis made for single granular gases.

  4. Comparing methods to estimate Reineke’s maximum size-density relationship species boundary line slope

    Science.gov (United States)

    Curtis L. VanderSchaaf; Harold E. Burkhart

    2010-01-01

    Maximum size-density relationships (MSDR) provide natural resource managers useful information about the relationship between tree density and average tree size. Obtaining a valid estimate of how maximum tree density changes as average tree size changes is necessary to accurately describe these relationships. This paper examines three methods to estimate the slope of...

  5. An assessment of spatio-temporal relationships between nocturnal bird migration traffic rates and diurnal bird stopover density.

    Science.gov (United States)

    Horton, Kyle G; Shriver, W Gregory; Buler, Jeffrey J

    2016-01-01

    Daily magnitudes and fluxes of landbird migration are often measured via nocturnal traffic rates aloft or diurnal densities within terrestrial habitats during stopover. However, these measures are not consistently correlated and at times reveal opposing trends. For this reason we sought to determine how comparison methods (daily magnitude or daily flux), nocturnal monitoring tools (weather surveillance radar, WSR; thermal imaging, TI), and temporal scale (preceding or following diurnal sampling) influenced correlation strength from stopover densities estimated by daily transect counts. We quantified nocturnal traffic rates at two temporal scales; averaged across the entire night and within individual decile periods of the night, and at two spatial scales; within 1 km of airspace surrounding the site via WSR and directly overhead within the narrow beam of a TI. Overall, the magnitude of daily bird density during stopover was positively related to the magnitude of broad-scale radar traffic rates of migrants on preceding and following nights during both the spring and fall. These relationships were strongest on the following night, and particularly from measures early in the night. Only during the spring on the following nights did we find positive correlations between the daily flux of transect counts and migration traffic rates (both WSR and TI). This indicates that our site likely had a more consistent daily turnover of migrants compared to the fall. The lack of general correlations between seasonal trends or daily flux in fine-scale TI traffic rates and stopover densities across or within nights was unexpected and likely due to poor sampling of traffic rates due to the camera's narrow beam. The order (preceding or following day) and metric of comparisons (magnitude or flux), as well as the tool (WSR or TI) used for monitoring nocturnal migration traffic can have dramatic impacts when compared with ground-based estimates of migrant density. WSR provided measures

  6. Modification of SOL profiles and fluctuations with line-average density and divertor flux expansion in TCV

    DEFF Research Database (Denmark)

    Vianello, N.; Tsui, C.; Theiler, C.

    2017-01-01

    A set of Ohmic density ramp experiments addressing the role of parallel connection length in modifying scrape off layer (SOL) properties has been performed on the TCV tokamak. The parallel connection length has been modified by varying the poloidal flux expansion fx. It will be shown that this mo......A set of Ohmic density ramp experiments addressing the role of parallel connection length in modifying scrape off layer (SOL) properties has been performed on the TCV tokamak. The parallel connection length has been modified by varying the poloidal flux expansion fx. It will be shown...... that this modification does not influence neither the detachment density threshold, nor the development of a flat SOL density profile which instead depends strongly on the increase of the core line average density. The modification of the SOL upstream profile, with the appearance of what is generally called a density...... shoulder, has been related to the properties of filamentary blobs. Blob size increases with density, without any dependence on the parallel connection length both in the near and far SOL. The increase of the density decay length, corresponding to a profile flattening, has been related to the variation...

  7. The relation between radio flux density and ionizing ultra-violet flux for HII regions and supernova remnants in the Large Magellanic cloud

    Directory of Open Access Journals (Sweden)

    Filipović M.D.

    2003-01-01

    Full Text Available We present a comparison between the Parkes radio surveys (Filipović et al 1995 and Vacuum Ultra-Violet (VUV surveys (Smith et al. 1987 of the Large Magellanic Clouds (LMC. We have found 72 sources in common in the LMC which are known HII regions (52 and supernova remnants (SNRs (19. Some of these radio sources are associated with two or more UV stellar associations. A comparison of the radio flux densities and ionizing UV flux for HII regions shows a very good correlation, as expected from theory. Many of the Magellanic Clouds (MCs SNRs are embedded in HII regions, so there is also a relation between radio and UV which we attribute to the surrounding HII regions.

  8. Phototactic number-density flux in the localized bioconvection of Euglena gracilis

    Science.gov (United States)

    Shoji, Erika; Suematsu, Nobuhiko; Nishimori, Hiraku; Awazu, Akinori; Izumi, Shunsuke; Iima, Makoto

    2014-11-01

    Euglena gracilis is a unicellular phototactic flagellate; it escapes from light sources if the light intensity is higher than 200 W/m2 (negative phototaxis). When the suspension of E. gracilis is illuminated from the bottom by strong light, bioconvection patterns are generated. In the case of E. gracilis, the patterns can be spatially localized. The localization mechanism has not been clarified. We report experimental results related to the localization mechanism. In particular, we experimentally measured the strength of the phototaxis in the lateral direction as well as vertical direction. We prepared a thin container in which the suspension is included, and gave the linearly-changing light intensity. We found the number density gets a peak at a particular light intensity, which never happens if the suspension has the vertical phototaxis only. Further, we succeeded in getting the function representing lateral phototaxis. The relationship between the measured functions and the localized convection cells will be also reported.

  9. A dynamo theory prediction for solar cycle 22: Sunspot number, radio flux, exospheric temperature, and total density at 400 km

    Science.gov (United States)

    Schatten, K. H.; Hedin, A. E.

    1986-01-01

    Using the dynamo theory method to predict solar activity, a value for the smoothed sunspot number of 109 + or - 20 is obtained for solar cycle 22. The predicted cycle is expected to peak near December, 1990 + or - 1 year. Concommitantly, F(10.7) radio flux is expected to reach a smoothed value of 158 + or - 18 flux units. Global mean exospheric temperature is expected to reach 1060 + or - 50 K and global total average total thermospheric density at 400 km is expected to reach 4.3 x 10 to the -15th gm/cu cm + or - 25 percent.

  10. A dynamo theory prediction for solar cycle 22 - Sunspot number, radio flux, exospheric temperature, and total density at 400 km

    Science.gov (United States)

    Schatten, K. H.; Hedin, A. E.

    1984-01-01

    Using the 'dynamo theory' method to predict solar activity, a value for the smoothed sunspot number of 109 + or - 20 is obtained for solar cycle 22. The predicted cycle is expected to peak near December, 1990 + or - 1 year. Concommitantly, F(10.7) radio flux is expected to reach a smoothed value of 158 + or - 18 flux units. Global mean exospheric temperature is expected to reach 1060 + or - 50 K and global total average total thermospheric density at 400 km is expected to reach 4.3 x 10 to the -15th gm/cu cm + or - 25 percent.

  11. Application of sensitive and supersensitive radon detectors for radon flux density and radon concentration in environmental monitoring

    International Nuclear Information System (INIS)

    Zahorowski, W.; Whittlestone, S.

    1997-01-01

    The paper presents a review of principles and operational parameters of the latest instrumental development in sensitive and high sensitive radon detectors at Australian Nuclear Science and Technology Organisation (ANSTO). The focus is on advances in measurement technology of radon concentration in air and radon flux density. Two areas in which ANSTO is actively involved are discussed. The first area concerns radon in air monitoring at Cape Grim Baseline Air Pollution Station. Results recorded at the Station with a supersensitive radon detector characterised by lower limit of detection down to few mBq m -3 with time resolution better than 90 minutes are presented to illustrate importance of the technique in global monitoring of airborne pollution. The second area concerns estimates of radon and thoron fluxes from large geographical areas. This is illustrated by results obtained during an Australia-wide survey of radon fluxes and from thoron flux measurements around the Mauna Loa Observatory in Hawaii. The radon flux estimates from Australia come from a coarse net of spot measurements combined with data from aerial gamma surveys. It is argued that as radon global flux and air concentration estimates improve, the data will provide progressively more stringent tests of global air transport models. (author)

  12. Industrialization of nanocrystalline Fe–Si–B–P–Cu alloys for high magnetic flux density cores

    International Nuclear Information System (INIS)

    Takenaka, Kana; Setyawan, Albertus D.; Sharma, Parmanand; Nishiyama, Nobuyuki; Makino, Akihiro

    2016-01-01

    Nanocrystalline Fe–Si–B–P–Cu alloys exhibit high saturation magnetic flux density (B s ) and extremely low magnetic core loss (W), simultaneously. Low amorphous-forming ability of these alloys hinders their application potential in power transformers and motors. Here we report a solution to this problem. Minor addition of C is found to be effective in increasing the amorphous-forming ability of Fe–Si–B–P–Cu alloys. It allows fabrication of 120 mm wide ribbons (which was limited to less than 40 mm) without noticeable degradation in magnetic properties. The nanocrystalline (Fe 85.7 Si 0.5 B 9.5 P 3.5 Cu 0.8 ) 99 C 1 ribbons exhibit low coercivity (H c )~4.5 A/m, high B s ~1.83 T and low W~0.27 W/kg (@ 1.5 T and 50 Hz). Success in fabrication of long (60–100 m) and wide (~120 mm) ribbons, which are made up of low cost elements is promising for mass production of energy efficient high power transformers and motors - Highlights: • Minor addition of C in FeSiBPCu alloy increases amorphous-forming ability. • The FeSiBPCuC alloy exhibits B s close to Si-steel and Core loss lower than it. • Excellent soft magnetic properties were obtained for 120 mm wide ribbons. • Nanocrystalline FeSiBPCuC alloy can be produced at industrial scale with low cost. • The alloy is suitable for making low energy loss power transformers and motors.

  13. Optimization of multiply acquired magnetic flux density B(z) using ICNE-Multiecho train in MREIT.

    Science.gov (United States)

    Nam, Hyun Soo; Kwon, Oh In

    2010-05-07

    The aim of magnetic resonance electrical impedance tomography (MREIT) is to visualize the electrical properties, conductivity or current density of an object by injection of current. Recently, the prolonged data acquisition time when using the injected current nonlinear encoding (ICNE) method has been advantageous for measurement of magnetic flux density data, Bz, for MREIT in the signal-to-noise ratio (SNR). However, the ICNE method results in undesirable side artifacts, such as blurring, chemical shift and phase artifacts, due to the long data acquisition under an inhomogeneous static field. In this paper, we apply the ICNE method to a gradient and spin echo (GRASE) multi-echo train pulse sequence in order to provide the multiple k-space lines during a single RF pulse period. We analyze the SNR of the measured multiple B(z) data using the proposed ICNE-Multiecho MR pulse sequence. By determining a weighting factor for B(z) data in each of the echoes, an optimized inversion formula for the magnetic flux density data is proposed for the ICNE-Multiecho MR sequence. Using the ICNE-Multiecho method, the quality of the measured magnetic flux density is considerably increased by the injection of a long current through the echo train length and by optimization of the voxel-by-voxel noise level of the B(z) value. Agarose-gel phantom experiments have demonstrated fewer artifacts and a better SNR using the ICNE-Multiecho method. Experimenting with the brain of an anesthetized dog, we collected valuable echoes by taking into account the noise level of each of the echoes and determined B(z) data by determining optimized weighting factors for the multiply acquired magnetic flux density data.

  14. Placed in a steady magnetic field, the flux density inside a permalloy-shielded volume decreases over hours and days

    Science.gov (United States)

    Feinberg, Benedict; Gould, Harvey

    2018-03-01

    Following the application of an external magnetic field to a thin-walled demagnetized Permalloy cylinder, the magnetic flux density at the center of the shielded volume decreases by roughly 20% over periods of hours to days. We measured this effect for applied magnetic fields from 0.48 A/m to 16 A/m, the latter being comparable to the Earths magnetic field at its weakest point. Delayed changes in magnetic flux density are also observed following alternating current demagnetization. We attribute these effects to delayed changes in magnetization, which have previously been observed in thin Permalloy films and small bulk samples of ferromagnetic materials. Phenomenological models of thermal activation are discussed. Some possible effects on experiments that rely on static shielding are noted.

  15. Measurement of the light flux density patterns from luminaires proposed as photon sources for photosynthesis during space travel

    Science.gov (United States)

    Walker, Paul N.

    1989-01-01

    Two luminaires were evaluated to determine the light flux density pattern on a horizontal plane surface. NASA supplied both luminaires; one was made by NASA and the other is commercially available. Tests were made for three combinations of luminaire height and luminaire lens material using the NASA luminaire; only one configuration of the commercial luminaire was tested. Measurements were made using four sensors with different wavelength range capabilities. The data are presented in graphical and tabular formats.

  16. Magnetic flux density distribution in superconducting cylinders of arbitrary cross section subjected to an axial magnetic field

    Science.gov (United States)

    Fournet, G.

    1982-07-01

    We show here how the application of the critical state model allows one to determine the magnetic flux density B⃗ in each point of a superconducting cylinder with an arbitrary cross section subjected to axial magnetic fields Hz; the B = 0 boundaries of the regions occupied by the vortices are so defined. We successively consider the cases where the critical current density Jc is either isotropic (constant or an arbitrary function of B) or tensorial, which means, for our problem, the use of two components Jcx and Jcy (either constant or depending on B but Jcx/Jcy remaining constant).

  17. Optimizing Power Density and Efficiency of a Double-Halbach Array Permanent-Magnet Ironless Axial-Flux Motor

    Science.gov (United States)

    Duffy, Kirsten P.

    2016-01-01

    NASA Glenn Research Center is investigating hybrid electric and turboelectric propulsion concepts for future aircraft to reduce fuel burn, emissions, and noise. Systems studies show that the weight and efficiency of the electric system components need to be improved for this concept to be feasible. This effort aims to identify design parameters that affect power density and efficiency for a double-Halbach array permanent-magnet ironless axial flux motor configuration. These parameters include both geometrical and higher-order parameters, including pole count, rotor speed, current density, and geometries of the magnets, windings, and air gap.

  18. On the Relationship Between High Speed Solar Wind Streams and Radiation Belt Electron Fluxes

    Science.gov (United States)

    Zheng, Yihua

    2011-01-01

    Both past and recent research results indicate that solar wind speed has a close connection to radiation belt electron fluxes [e.g., Paulikas and Blake, 1979; Reeves et aI., 2011]: a higher solar wind speed is often associated with a higher level of radiation electron fluxes. But the relationship can be very complex [Reeves et aI., 2011]. The study presented here provides further corroboration of this viewpoint by emphasizing the importance of a global perspective and time history. We find that all the events during years 2010 and 2011 where the >0.8 MeV integral electron flux exceeds 10(exp 5) particles/sq cm/sr/s (pfu) at GEO orbit are associated with the high speed streams (HSS) following the onset of the Stream Interaction Region (SIR), with most of them belonging to the long-lasting Corotating Interaction Region (CIR). Our preliminary results indicate that during HSS events, a maximum speed of 700 km/s and above is a sufficient but not necessary condition for the > 0.8 MeV electron flux to reach 10(exp 5) pfu. But in the exception cases of HSS events where the electron flux level exceeds the 10(exp 5) pfu value but the maximum solar wind speed is less than 700 km/s, a prior impact can be noted either from a CME or a transient SIR within 3-4 days before the arrival of the HSS - stressing the importance of time history. Through superposed epoch analysis and studies providing comparisons with the CME events and the HSS events where the flux level fails to reach the 10(exp 5) pfu, we will present the quantitative assessment of behaviors and relationships of various quantities, such as the time it takes to reach the flux threshold value from the stream interface and its dependence on different physical parameters (e.g., duration of the HSS event, its maximum or average of the solar wind speed, IMF Bz, Kp). The ultimate goal is to apply what is derived to space weather forecasting.

  19. Simulating the effect of high column density absorbers on the one-dimensional Lyman α forest flux power spectrum

    Science.gov (United States)

    Rogers, Keir K.; Bird, Simeon; Peiris, Hiranya V.; Pontzen, Andrew; Font-Ribera, Andreu; Leistedt, Boris

    2018-03-01

    We measure the effect of high column density absorbing systems of neutral hydrogen (H I) on the one-dimensional (1D) Lyman α forest flux power spectrum using cosmological hydrodynamical simulations from the Illustris project. High column density absorbers (which we define to be those with H I column densities N(H I) > 1.6 × 10^{17} atoms cm^{-2}) cause broadened absorption lines with characteristic damping wings. These damping wings bias the 1D Lyman α forest flux power spectrum by causing absorption in quasar spectra away from the location of the absorber itself. We investigate the effect of high column density absorbers on the Lyman α forest using hydrodynamical simulations for the first time. We provide templates as a function of column density and redshift, allowing the flexibility to accurately model residual contamination, i.e. if an analysis selectively clips out the largest damping wings. This flexibility will improve cosmological parameter estimation, for example, allowing more accurate measurement of the shape of the power spectrum, with implications for cosmological models containing massive neutrinos or a running of the spectral index. We provide fitting functions to reproduce these results so that they can be incorporated straightforwardly into a data analysis pipeline.

  20. A note on the effective evaluation height for flux-gradient relationships and its application to herbicide fluxes

    Science.gov (United States)

    Volatilization represents a significant loss pathway for many pesticides, herbicides and other agrochemicals. One common method for measuring the volatilization of agrochemicals is the flux-gradient method. Using this method, the chemical flux is estimated as the product of the vertical concentratio...

  1. Relationship of Quantum Entanglement to Density Functional Theory

    OpenAIRE

    Rajagopal, A. K.; Rendell, R. W.

    2005-01-01

    The maximum von Neumann entropy principle subject to given constraints of mean values of some physical observables determines the density matrix. Similarly the stationary action principle in the case of time-dependent (dissipative) situations under similar constraints yields the density matrix. The free energy and measures of entanglement are expressed in terms of such a density matrix and thus define respective functionals of the mean values. In the light of several model calculations, it is...

  2. Evidence that cell surface charge reduction modifes capillary red cell velocity-flux relationships in hamster cremaster muscle

    NARCIS (Netherlands)

    Vink, H.; Wieringa, P. A.; Spaan, J. A.

    1995-01-01

    1. From capillary red cell velocity (V)-flux (F) relationships of hamster cremaster muscle a yield velocity (VF = 0) can be derived at which red cell flux is zero. Red cell velocity becomes intermittent and/or red blood cells come to a complete standstill for velocities close to this yield velocity,

  3. Modification of SOL profiles and fluctuations with line-average density and divertor flux expansion in TCV

    Science.gov (United States)

    Vianello, N.; Tsui, C.; Theiler, C.; Allan, S.; Boedo, J.; Labit, B.; Reimerdes, H.; Verhaegh, K.; Vijvers, W. A. J.; Walkden, N.; Costea, S.; Kovacic, J.; Ionita, C.; Naulin, V.; Nielsen, A. H.; Rasmussen, J. Juul; Schneider, B.; Schrittwieser, R.; Spolaore, M.; Carralero, D.; Madsen, J.; Lipschultz, B.; Militello, F.; The TCV Team; The EUROfusion MST1 Team

    2017-11-01

    A set of Ohmic density ramp experiments addressing the role of parallel connection length in modifying scrape off layer (SOL) properties has been performed on the TCV tokamak. The parallel connection length has been modified by varying the poloidal flux expansion f x . It will be shown that this modification does not influence neither the detachment density threshold, nor the development of a flat SOL density profile which instead depends strongly on the increase of the core line average density. The modification of the SOL upstream profile, with the appearance of what is generally called a density shoulder, has been related to the properties of filamentary blobs. Blob size increases with density, without any dependence on the parallel connection length both in the near and far SOL. The increase of the density decay length, corresponding to a profile flattening, has been related to the variation of the divertor normalized collisionality Λ_div (Myra et al 2006 Phys. Plasmas 13 112502, Carralero et al, ASDEX Upgrade Team, JET Contributors and EUROfusion MST1 Team 2015 Phys. Rev. Let. 115 215002), showing that in TCV the increase of Λ_div is not sufficient to guarantee the SOL upstream profile flattening.

  4. Solar Modulation of Inner Trapped Belt Radiation Flux as a Function of Atmospheric Density

    Science.gov (United States)

    Lodhi, M. A. K.

    2005-01-01

    No simple algorithm seems to exist for calculating proton fluxes and lifetimes in the Earth's inner, trapped radiation belt throughout the solar cycle. Most models of the inner trapped belt in use depend upon AP8 which only describes the radiation environment at solar maximum and solar minimum in Cycle 20. One exception is NOAAPRO which incorporates flight data from the TIROS/NOAA polar orbiting spacecraft. The present study discloses yet another, simple formulation for approximating proton fluxes at any time in a given solar cycle, in particular between solar maximum and solar minimum. It is derived from AP8 using a regression algorithm technique from nuclear physics. From flux and its time integral fluence, one can then approximate dose rate and its time integral dose.

  5. Performance of a high resolution, high flux density SGM undulator beamline at the ALS

    International Nuclear Information System (INIS)

    Warwick, T.; Heimann, P.; Mossessian, D.; McKinney, W.; Padmore, H.

    1994-01-01

    The performance of ALS beamline 7.0 is described. This is an integrated system for delivering radiation from a 5cm period undulator to spectroscopy and microscopy experiments across the range of photon energies from 60eV to 1200eV. The beamline is engineered to deliver the highest possible flux, with negligible deformation of the optic surfaces due to heating. Two experiment stations are served with rapid interchangeability. We report on the measured operational parameters, the resolution and flux delivered, and the refocus of the light into a small spot at the experiment

  6. Estimation of transient heat flux density during the heat supply of a catalytic wall steam methane reformer

    Science.gov (United States)

    Settar, Abdelhakim; Abboudi, Saïd; Madani, Brahim; Nebbali, Rachid

    2018-02-01

    Due to the endothermic nature of the steam methane reforming reaction, the process is often limited by the heat transfer behavior in the reactors. Poor thermal behavior sometimes leads to slow reaction kinetics, which is characterized by the presence of cold spots in the catalytic zones. Within this framework, the present work consists on a numerical investigation, in conjunction with an experimental one, on the one-dimensional heat transfer phenomenon during the heat supply of a catalytic-wall reactor, which is designed for hydrogen production. The studied reactor is inserted in an electric furnace where the heat requirement of the endothermic reaction is supplied by electric heating system. During the heat supply, an unknown heat flux density, received by the reactive flow, is estimated using inverse methods. In the basis of the catalytic-wall reactor model, an experimental setup is engineered in situ to measure the temperature distribution. Then after, the measurements are injected in the numerical heat flux estimation procedure, which is based on the Function Specification Method (FSM). The measured and estimated temperatures are confronted and the heat flux density which crosses the reactor wall is determined.

  7. New flux based dose-response relationships for ozone for European forest tree species.

    Science.gov (United States)

    Büker, P; Feng, Z; Uddling, J; Briolat, A; Alonso, R; Braun, S; Elvira, S; Gerosa, G; Karlsson, P E; Le Thiec, D; Marzuoli, R; Mills, G; Oksanen, E; Wieser, G; Wilkinson, M; Emberson, L D

    2015-11-01

    To derive O3 dose-response relationships (DRR) for five European forest trees species and broadleaf deciduous and needleleaf tree plant functional types (PFTs), phytotoxic O3 doses (PODy) were related to biomass reductions. PODy was calculated using a stomatal flux model with a range of cut-off thresholds (y) indicative of varying detoxification capacities. Linear regression analysis showed that DRR for PFT and individual tree species differed in their robustness. A simplified parameterisation of the flux model was tested and showed that for most non-Mediterranean tree species, this simplified model led to similarly robust DRR as compared to a species- and climate region-specific parameterisation. Experimentally induced soil water stress was not found to substantially reduce PODy, mainly due to the short duration of soil water stress periods. This study validates the stomatal O3 flux concept and represents a step forward in predicting O3 damage to forests in a spatially and temporally varying climate. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  8. Momentum transport and nonlocality in heat-flux-driven magnetic reconnection in high-energy-density plasmas

    Science.gov (United States)

    Liu, Chang; Fox, William; Bhattacharjee, Amitava; Thomas, Alexander G. R.; Joglekar, Archis S.

    2017-10-01

    Recent theory has demonstrated a novel physics regime for magnetic reconnection in high-energy-density plasmas where the magnetic field is advected by heat flux via the Nernst effect. Here we elucidate the physics of the electron dissipation layer in this regime. Through fully kinetic simulation and a generalized Ohm's law derived from first principles, we show that momentum transport due to a nonlocal effect, the heat-flux-viscosity, provides the dissipation mechanism for magnetic reconnection. Scaling analysis, and simulations show that the reconnection process comprises a magnetic field compression stage and quasisteady reconnection stage, and the characteristic width of the current sheet in this regime is several electron mean-free paths. These results show the important interplay between nonlocal transport effects and generation of anisotropic components to the distribution function.

  9. Simulation study of geometric shape factor approach to estimating earth emitted flux densities from wide field-of-view radiation measurements

    Science.gov (United States)

    Weaver, W. L.; Green, R. N.

    1980-01-01

    A study was performed on the use of geometric shape factors to estimate earth-emitted flux densities from radiation measurements with wide field-of-view flat-plate radiometers on satellites. Sets of simulated irradiance measurements were computed for unrestricted and restricted field-of-view detectors. In these simulations, the earth radiation field was modeled using data from Nimbus 2 and 3. Geometric shape factors were derived and applied to these data to estimate flux densities on global and zonal scales. For measurements at a satellite altitude of 600 km, estimates of zonal flux density were in error 1.0 to 1.2%, and global flux density errors were less than 0.2%. Estimates with unrestricted field-of-view detectors were about the same for Lambertian and non-Lambertian radiation models, but were affected by satellite altitude. The opposite was found for the restricted field-of-view detectors.

  10. Thickness evaluation using a new relationship between film density and penetrated thickness in radiography

    International Nuclear Information System (INIS)

    Lee, Sung Sik; Kim, Young H.

    2005-01-01

    In order to improve the accuracies in the thickness evaluation using radiography, a new relationship between film density and penetrated thickness has been proposed, and experimental verification of the proposed relationship was carried out by using the X- and γ-ray radiographs of two carbon steel step wedges. A new parameter, the logarithmic gradient of film density, was defined in order to express the characteristics of the radiographic film for wider range of film density. A new relationship between the film density and the penetrated thickness were formulated using the logarithmic gradient of the film density. In experiment, the logarithmic gradient of the film density was independent on both the exposure and the film density and measured for the radiographic film used in the present work from the slope of the fitting lines for the same penetrated thickness. Experimental results verifies the accuracy of the proposed relationship between film density and the penetrated thickness for the range of film density from 1.0 to 3.5. The thickness can be more accurately determined by using the proposed relationship and the parameters determined by experiment. It is also found that the γ-ray having simple energy spectrum is more appropriate radiation source for the evaluation of the thickness from the film density of the radiograph

  11. A DETERMINATION OF THE FLUX DENSITY IN CORE OF DISTRIBUTION TRANSFORMERS, WHAT BUILT WITH THE COMMON USING OF GRAIN AND NON GRAIN ORIENTED MAGNETIC STEELS

    Directory of Open Access Journals (Sweden)

    I.V. Pentegov

    2015-12-01

    Full Text Available Purpose. The development of calculation method to determinate the flux densities in different parts of the magnetic cores of distribution transformers, what built from different types magnetic steel (mixed core. Methodology. The method is based on the scientific positions of Theoretical Electrical Engineering – the theory of the electromagnetic field in nonlinear mediums to determine the distribution of magnetic flux in mixed core of transformer, what are using different types of steel what have the different magnetic properties. Results. The developed method gives possible to make calculation of the flux density and influence of skin effect in different parts of the magnetic cores of distribution transformer, where are used mix of grain oriented (GO and non grain oriented (NGO steels. Was determinate the general basic conditions for the calculation of flux density in the laminations from grain and non grain oriented steels of the magnetic core: the strength of magnetic field for the laminations of particular part of mixed core is the same; the sum of the magnetic fluxes in GO and NGO steels in particular part of mixed core is equal with the designed magnetic flux in this part of mixed core. Discover, the magnetic flux in mixed core of the transformer has specific distribution between magnetic steels. The flux density is higher in laminations from GO steel and smaller in laminations from the NGO steel. That is happened because for magnetic flux is easier pass through laminations from GO steel, what has better magnetic conductance than laminations from NGO steel. Originality. The common using of different types of magnetic steels in cores for distribution transformers gives possibility to make design of transformer with low level of no load losses, high efficiency and with optimal cost. Practical value. The determination of the flux density in different parts of magnetic core with GO and NGO steels gives possibility make accurate calculation of

  12. Wind Effects on Flow Patterns and Net Fluxes in Density-Driven High-Latitude Channel Flow

    Science.gov (United States)

    Huntley, Helga S.; Ryan, Patricia

    2018-01-01

    A semianalytic two-dimensional model is used to analyze the interplay between the different forces acting on density-driven flow in high-latitude channels. In particular, the balance between wind stress, viscous forces, baroclinicity, and sea surface slope adjustments under specified flux conditions is examined. Weak winds are found not to change flow patterns appreciably, with minimal (change the flow significantly, especially at the surface, by either strengthening the dual-jet pattern, established without wind, by a factor of 2-3 or initiating return flow at the surface. A nonzero flux does not result in the addition of a uniform velocity throughout the channel cross section, but modifies both along-channel and cross-channel velocities to become more symmetric, dominated by a down-channel jet centered in the domain and counter-clockwise lateral flow. We also consider formulations of the model that allow adjustments of the net flux in response to the wind. Flow patterns change, beyond uniform intensification or weakening, only for strong winds and high Ekman number. Comparisons of the model results to observational data collected in Nares Strait in the Canadian Archipelago in the summer of 2007 show rough agreement, but the model misses the upstream surface jet on the east side of the strait and propagates bathymetric effects too strongly in the vertical for this moderately high eddy viscosity. Nonetheless, the broad strokes of the observed high-latitude flow are reproduced.

  13. The relationship between population density and cancer mortality in Taiwan.

    Science.gov (United States)

    Yang, C Y; Hsieh, Y L

    1998-04-01

    Many investigators have examined urbanization gradients in cancer rates. The purpose of this report was to identify urban-rural trends in cancer mortality rates (1982-1991) for municipalities in Taiwan. For this purpose, Taiwan's municipalities were classified as rural, suburban, urban, or metropolitan, using population density as an ordinal indicator of the degree of urbanization. Average annual age-adjusted, site-specific cancer mortality rates were calculated for both sexes within each population density group. Significant increasing trends with more urbanization were observed in mortality rates for cancers of the lung, pancreas, and kidney among both males and females, as well as male prostate cancer, and female breast and ovary cancer. In addition, this study revealed a significant rural excess for nonmelanoma skin cancer among both males and females, as well as male non-Hodgkin's lymphoma, and cancers of the female bone, and female connective tissue. Analytic studies for sites with consistent urban-rural trends may be fruitful in identifying the aspect of population density, or other unmeasured factors, that contribute to these trends.

  14. Responses of Sap Flux Density to Changing Atmospheric Humidity in Three Common Street Tree Species in Bangkok, Thailand

    Directory of Open Access Journals (Sweden)

    Pantana Tor-ngern

    2016-09-01

    Full Text Available Efficient water management in urban landscape is imperative under the projected increases in drought stress under future climate. Because different tree species have different stomatal regulations to prevent water loss under water limitation, comparative study of species-specific responses of water use to changing weather conditions will benefit selective planting of urban trees for sustainable urban greening management. Here, we performed a simple and short-term investigation of water use characteristics of three common street tree species in Bangkok, a major city in Southeast Asia. Species included Pterocarpus indicus (Pi, Swietenia macrophylla (Sm and Lagerstroemia speciosa (Ls. We used self-constructed heat dissipation probes to track water uptake rates, expressed as sap flux density (JS, in stems of potted trees and examined their diurnal variations with changing atmospheric humidity, represented by vapor pressure deficit (D. The results implied that two of the three species: Pi and Sm, may be selected for planting because their Js was less sensitive to changing D compared to Ls. The sap flux density of Ls increased more rapidly with rising D, implying higher sensitivity to drought in Ls, compared to the other two species. Nevertheless, further study on large trees and under longer period of investigation, covering both dry and wet seasons, is required to confirm this finding.

  15. Importance of 3-D radiant flux densities for outdoor human thermal comfort on clear-sky summer days in Freiburg, Southwest Germany

    OpenAIRE

    Hyunjung Lee; Helmut Mayer; Dirk Schindler

    2014-01-01

    This study concerns the role of short- and long-wave radiant flux densities from different directions in complex urban settings for human thermal comfort on clear-sky summer days. The aims of the investigation are to quantify the importance of the sky view factor as an urban design-dependent variable for the 3-D radiant flux densities absorbed by the standardized human-biometeorological reference person and to analyze the varying impact of the absorbed 3-D short- and long-wave radiant flux de...

  16. Far scrape-off layer particle and heat fluxes in high density

    DEFF Research Database (Denmark)

    Müller, H. W.; Bernert, M.; Carralero, D.

    2014-01-01

    The far scrape-off layer transport is studied in ASDEX Upgrade H-mode discharges with high divertor neutral density N0,div, high power across the separatrix Psep and nitrogen seeding to control the divertor temperature. Such conditions are expected for ITER but usually not investigated in terms...

  17. Comparison between measured and computed magnetic flux density distribution of simulated transformer core joints assembled from grain-oriented and non-oriented electrical steel

    Science.gov (United States)

    Shahrouzi, Hamid; Moses, Anthony J.; Anderson, Philip I.; Li, Guobao; Hu, Zhuochao

    2018-04-01

    The flux distribution in an overlapped linear joint constructed in the central region of an Epstein Square was studied experimentally and results compared with those obtained using a computational magnetic field solver. High permeability grain-oriented (GO) and low permeability non-oriented (NO) electrical steels were compared at a nominal core flux density of 1.60 T at 50 Hz. It was found that the experimental results only agreed well at flux densities at which the reluctance of different paths of the flux are similar. Also it was revealed that the flux becomes more uniform when the working point of the electrical steel is close to the knee point of the B-H curve of the steel.

  18. Initial density affects biomass – density and allometric relationships in self-thinning populations of Fagopyrum esculentum

    DEFF Research Database (Denmark)

    Li, Lei; Weiner, Jacob; Zhou, Daowei

    2013-01-01

    and the biomass–density trajectory, we grew Fagopyrum esculentum populations at three high densities and measured shoot biomass, density and the height and diameter of individual plants at six harvests. * Initial density did not affect the slope of the log biomass–log density relationship, but there was a clear...... by the biomass density: the relationship between mass and volume. Initial density could affect this by altering allometric growth in a way that influences architectural compactness. An alternative hypothesis is that competition at higher initial density is more size symmetric, which has been shown to reduce...

  19. Thin film magnetic head with improved flux concentration for high density recording/playback utilizing superconductors

    International Nuclear Information System (INIS)

    Pisharody, R.K.; Miller, S.D.; Gooch, B.R.; Petersen, D.A.

    1991-01-01

    This patent describes a thin film magnetic head for use with a magnetic medium. It comprises a core including a first and a second deposited layer of ferromagnetic material, each layer having a pole portion, each pole portion lying in a plane generally parallel to the other and generally perpendicular to a direction of motion of the recording medium, the pole portions being separated by a gap; a conductor, electromagnetically coupled to the core; a layer of superconductor material located between the pole portions in the gap for excluding magnetic flux from the gap; a first layer of superconductor shield material provided on a face of the pole portion of the first layer of ferromagnetic material opposite the gap; and a second layer of superconductor shield material provided on a face of the pole portion of the second layer of ferromagnetic material opposite the gap

  20. Relationships between carbon fluxes and environmental factors in a drip-irrigated, film-mulched cotton field in arid region

    OpenAIRE

    Li, Xiaoyu; Liu, Lijuan; Yang, Huijin; Li, Yan

    2018-01-01

    Environmental factors and human activities play important roles in carbon fixation and emissions generated from croplands. Eddy covariance measurements in a drip-irrigated, film-mulched cotton field were used to analyze the relationships between carbon fluxes and environmental factors in Wulanwusu, northern Xinjiang, an arid region of Northwest China. Our results showed that the cumulative net carbon flux (NEE) was -304.8 g C m-2 (a strong sink) over the whole cotton growing season in 2012, w...

  1. Influence of clouds on the spectral actinic flux density in the lower troposphere (INSPECTRO: overview of the field campaigns

    Directory of Open Access Journals (Sweden)

    C. Topaloglou

    2008-03-01

    Full Text Available Ultraviolet radiation is the key factor driving tropospheric photochemistry. It is strongly modulated by clouds and aerosols. A quantitative understanding of the radiation field and its effect on photochemistry is thus only possible with a detailed knowledge of the interaction between clouds and radiation. The overall objective of the project INSPECTRO was the characterization of the three-dimensional actinic radiation field under cloudy conditions. This was achieved during two measurement campaigns in Norfolk (East Anglia, UK and Lower Bavaria (Germany combining space-based, aircraft and ground-based measurements as well as simulations with the one-dimensional radiation transfer model UVSPEC and the three-dimensional radiation transfer model MYSTIC.

    During both campaigns the spectral actinic flux density was measured at several locations at ground level and in the air by up to four different aircraft. This allows the comparison of measured and simulated actinic radiation profiles. In addition satellite data were used to complete the information of the three dimensional input data set for the simulation. A three-dimensional simulation of actinic flux density data under cloudy sky conditions requires a realistic simulation of the cloud field to be used as an input for the 3-D radiation transfer model calculations. Two different approaches were applied, to derive high- and low-resolution data sets, with a grid resolution of about 100 m and 1 km, respectively.

    The results of the measured and simulated radiation profiles as well as the results of the ground based measurements are presented in terms of photolysis rate profiles for ozone and nitrogen dioxide. During both campaigns all spectroradiometer systems agreed within ±10% if mandatory corrections e.g. stray light correction were applied. Stability changes of the systems were below 5% over the 4 week campaign periods and negligible over a few days. The J(O1D data of

  2. Equine herpesviruses: antigenic relationships and deoxyribonucleic acid densities.

    Science.gov (United States)

    Plummer, G; Goodheart, C R; Studdert, M J

    1973-10-01

    Equine herpesviruses with a deoxyribonucleic acid density of 1.716 to 1.717 g/cm(3) were compared with one another by the plaque-reduction test and by the rate of development of cytopathic effect as indicated by plaque size in rabbit kidney cultures. Of the 19 isolates studied, the 9 which had already been tentatively labeled equine abortion viruses were serologically similar to one another; each of them grew more quickly than did any of the other 10 isolates although the mean plaque sizes formed a series of gradations with no clear hiatus which would permit the unequivocal delineation of the abortion viruses from the slowly growing strains. The 10 slowly growing isolates showed antigenic heterogeneity even though complement was present; the neutralizing capacity of an antiserum against the heterologous strains was, in most instances, markedly less than against the homologous strains, the range of the 50% endpoints being much greater than that observed among the equine abortion viruses, or among isolates of herpes simplex type 1. There was no cross neutralization between the equine abortion viruses and any of the 10 slowly growing isolates. An extra band of deoxyribonucleic acid, at 1.723 to 1.725 g/cm(3), was present in two of the slowly growing strains when originally grown in rabbit cells, but was no longer present after passage in cat cells. This band occupied the same position as one reported in the hamster-passaged strain of equine abortion virus, and had a density similar to that of the equine genital herpesvirus. Although the taxonomic demarcation of the equine abortion viruses and the slowly growing herpesviruses from one another is still open to question, they can be conveniently labeled equine herpesviruses 1 and 2, respectively; the genital virus would be termed equine herpesvirus 3.

  3. EFFECT OF BINDER ON THE RELATIONSHIP BETWEEN BULK-DENSITY AND COMPACTIBILITY OF LACTOSE GRANULATIONS

    NARCIS (Netherlands)

    ZUURMAN, K; BOLHUIS, GK; VROMANS, H

    1995-01-01

    The effect of a binder on the relationship between the bulk density and compactibility of lactose granulations was studied by comparing binderless granules with granules containing hydroxypropylcellulose. Granulations were prepared from different grades of alpha-lactose monohydrate and anhydrous

  4. Technical Note: Cortical thickness and density estimation from clinical CT using a prior thickness-density relationship

    Energy Technology Data Exchange (ETDEWEB)

    Humbert, Ludovic, E-mail: ludohumberto@gmail.com [Galgo Medical, Barcelona 08036 (Spain); Hazrati Marangalou, Javad; Rietbergen, Bert van [Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven 5600 MB (Netherlands); Río Barquero, Luis Miguel del [CETIR Centre Medic, Barcelona 08029 (Spain); Lenthe, G. Harry van [Biomechanics Section, KU Leuven–University of Leuven, Leuven 3001 (Belgium)

    2016-04-15

    Purpose: Cortical thickness and density are critical components in determining the strength of bony structures. Computed tomography (CT) is one possible modality for analyzing the cortex in 3D. In this paper, a model-based approach for measuring the cortical bone thickness and density from clinical CT images is proposed. Methods: Density variations across the cortex were modeled as a function of the cortical thickness and density, location of the cortex, density of surrounding tissues, and imaging blur. High resolution micro-CT data of cadaver proximal femurs were analyzed to determine a relationship between cortical thickness and density. This thickness-density relationship was used as prior information to be incorporated in the model to obtain accurate measurements of cortical thickness and density from clinical CT volumes. The method was validated using micro-CT scans of 23 cadaver proximal femurs. Simulated clinical CT images with different voxel sizes were generated from the micro-CT data. Cortical thickness and density were estimated from the simulated images using the proposed method and compared with measurements obtained using the micro-CT images to evaluate the effect of voxel size on the accuracy of the method. Then, 19 of the 23 specimens were imaged using a clinical CT scanner. Cortical thickness and density were estimated from the clinical CT images using the proposed method and compared with the micro-CT measurements. Finally, a case-control study including 20 patients with osteoporosis and 20 age-matched controls with normal bone density was performed to evaluate the proposed method in a clinical context. Results: Cortical thickness (density) estimation errors were 0.07 ± 0.19 mm (−18 ± 92 mg/cm{sup 3}) using the simulated clinical CT volumes with the smallest voxel size (0.33 × 0.33 × 0.5 mm{sup 3}), and 0.10 ± 0.24 mm (−10 ± 115 mg/cm{sup 3}) using the volumes with the largest voxel size (1.0 × 1.0 × 3.0 mm{sup 3}). A trend for the

  5. Importance of 3-D radiant flux densities for outdoor human thermal comfort on clear-sky summer days in Freiburg, Southwest Germany

    Directory of Open Access Journals (Sweden)

    Hyunjung Lee

    2014-09-01

    Full Text Available This study concerns the role of short- and long-wave radiant flux densities from different directions in complex urban settings for human thermal comfort on clear-sky summer days. The aims of the investigation are to quantify the importance of the sky view factor as an urban design-dependent variable for the 3-D radiant flux densities absorbed by the standardized human-biometeorological reference person and to analyze the varying impact of the absorbed 3-D short- and long-wave radiant flux densities on the mean radiant temperature (Tmrt$T_{\\text{mrt}}$, near-surface air temperature (Ta$T_{\\text{a}}$ and physiologically equivalent temperature (PET.The results obtained by measuring campaigns and numerical simulations point to the different importance of the absorbed 3-D radiant flux densities for human thermal comfort characterized by Ta$T_{\\text{a}}$, Tmrt$T_{\\text{mrt}}$ and PET. The magnitude of Tmrt$T_{\\text{mrt}}$ is mainly determined by the total of the absorbed 3-D long-wave radiant flux densities. However, the fluctuations of Tmrt$T_{\\text{mrt}}$ are mainly governed by the total of the absorbed 3-D short-wave radiant flux densities. Their variance can be well explained by the variance of the sky view factor related to the southern part of the upper half space. Taking account of the different impact of the 3-D radiant flux densities, Tmrt$T_{\\text{mrt}}$ can be quite well estimated by a multiple regression using the total of the absorbed 3-D short-wave radiant flux densities and the absorbed long-wave radiant flux density from the lower half space as independent variables. PET can be well estimated by a multiple regression showing Tmrt$T_{\\text{mrt}}$ and Ta$T_{\\text{a}}$ as independent variables. On a hot summer day, the increase of the albedo of vertical building walls within a simple E-W oriented street canyon leads to a decrease of the surface temperature of the S-facing wall, but to an increase of Tmrt$T_{\\text{mrt}}$ and PET

  6. Relationships between human population density and burned area at continental and global scales.

    Science.gov (United States)

    Bistinas, Ioannis; Oom, Duarte; Sá, Ana C L; Harrison, Sandy P; Prentice, I Colin; Pereira, José M C

    2013-01-01

    We explore the large spatial variation in the relationship between population density and burned area, using continental-scale Geographically Weighted Regression (GWR) based on 13 years of satellite-derived burned area maps from the global fire emissions database (GFED) and the human population density from the gridded population of the world (GPW 2005). Significant relationships are observed over 51.5% of the global land area, and the area affected varies from continent to continent: population density has a significant impact on fire over most of Asia and Africa but is important in explaining fire over population density is associated with both increased and decreased in fire. The nature of the relationship depends on land-use: increasing population density is associated with increased burned are in rangelands but with decreased burned area in croplands. Overall, the relationship between population density and burned area is non-monotonic: burned area initially increases with population density and then decreases when population density exceeds a threshold. These thresholds vary regionally. Our study contributes to improved understanding of how human activities relate to burned area, and should contribute to a better estimate of atmospheric emissions from biomass burning.

  7. Influence of the flux density on the radiation damage of bipolar silicon transistors by protons and electrons

    International Nuclear Information System (INIS)

    Bannikov, Y.; Gorin, B.; Kozhevnikov, V.; Mikhnovich, V.; Gusev, L.

    1981-01-01

    It was found experimentally that the radiation damage of bipolar n-p-n transistors increased by a factor of 8--12 when the proton flux density was reduced from 4.07 x 10 10 to 2.5 x 10 7 cm -2 sec -1 . In the case of p-n-p transistors the effect was opposite: there was a reduction in the radiation damage by a factor of 2--3 when the dose rate was lowered between the same limits. A similar effect was observed for electrons but at dose rates three orders of magnitude greater. The results were attributed to the dependences of the radiation defect-forming reactions on the charge state of defects which was influenced by the formation of disordered regions in the case of proton irradiation

  8. Rapid tuning CW laser technique for measurements of gas velocity, temperature, pressure, density, and mass flux using NO

    Science.gov (United States)

    Chang, Albert Y.; Dirosa, Michael D.; Davidson, David F.; Hanson, Ronald K.

    1991-01-01

    An intracavity-doubled rapid-tuning CW ring dye laser was used to acquire fully resolved absorption profiles of NO line pairs in the A-X band at 225 nm at a rate of 4 kHz. These profiles were utilized for simultaneous measurements of flow parameters in the high-speed 1D flows generated in a shock tube. Velocity was determined from the Doppler shift, measured using a pair of profiles simultaneously acquired at different angles with respect to the flow direction. Temperature was determined from the intensity ratio of the adjacent lines. Pressure and density were found both from the collisional broadening and the fractional absorption. From this information the mass flux was determined. The results compare well to 1D shock calculations.

  9. [Atorvastatin and oxidized low density lipoprotein antibody. Relationship to age].

    Science.gov (United States)

    Sánchez Muñoz-Torrero, Juan Francisco; Crespo, Leandro; Fernández Pereira, Luis; Pereira, Gema; Cámara, Carmen; Costo, Alberto

    2011-02-26

    In hypercholesterolemic patients, we studied the relationships of plasma levels of LDLoxab with cardiovascular variables and its changes after treatment with atorvastatin. We studied, in 48 patients, the levels of LDLoxab, as well as lipid, oxidative stress and inflammatory biomarkers, at baseline and 24 weeks after treatment with 20mg of atorvastatin. Baseline: a correlation was observed between LDLoxab and age (r= 0.41, P=.03), waist (r=0.38, P=.04) and C reactive protein (r= 0.46, P=.02), but not with other variables. Atorvastatin treatment did not decrease LDLoxab;(mU/mL, median [CI 95%]: baseline: 413 [187-1,196] and 24 weeks: 349 [101-1559]). The percentage change at week 24, was negatively correlated with age (r=-0.37, P=.03) but not with other variables. In hypercholesterolemic subjects plasma LDLoxab levels were positively corelated with age, waist and C reactive protein. There were no changes in plasma levels of LDLoxab after treatment with atorvastatin, but the variation was associated with age, suggesting that the immunomodulatory actions may depend of this. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  10. On the secular decrease of radio emission flux densities of the supernova remnants of Cassiopeia A and Taurus A at frequency 927 MHz

    International Nuclear Information System (INIS)

    Vinyajkin, E.N.; Razin, V.A.

    1979-01-01

    Relative measurements of the radio emission flux densities of the supernova remnants of Cassiopeia A and Taurus A were made at the frequency 927 MHz to investigate the secular decrease of their intensity. Experiments were fulfilled in October-December 1977 at the 10-meter radio telescope of the radioastronomical station Staraya Pustyn' (NIRFI). The radio galaxied of Cygnus A, Virgo A and Orion Nebula were taken as the comparison sources. The comparison of the data obtained with the results of absolute measurements carried out in October 1962 permits to state that during 15 years the radio emission flux density of Cassiopeia A decreased by (14.2+-0.6)% (the average annual decrease amounts to (0.95+-O.04)%) and the radio emission flux density of Taurus A decreased by (2.7+-0.1)% (the annual decrease is (0.18+-0.01)%)

  11. [Measurements of the flux densities of static magnetic fields generated by two types of dental magnetic attachments and their retentive forces].

    Science.gov (United States)

    Xu, Chun; Chao, Yong-lie; Du, Li; Yang, Ling

    2004-05-01

    To measure and analyze the flux densities of static magnetic fields generated by two types of commonly used dental magnetic attachments and their retentive forces, and to provide guidance for the clinical application of magnetic attachments. A digital Gaussmeter was used to measure the flux densities of static magnetic fields generated by two types of magnetic attachments, under four circumstances: open-field circuit; closed-field circuit; keeper and magnet slid laterally for a certain distance; and existence of air gap between keeper and magnet. The retentive forces of the magnetic attachments in standard closed-field circuit, with the keeper and magnet sliding laterally for a certain distance or with a certain air gap between keeper and magnet were measured by a tensile testing machine. There were flux leakages under both the open-field circuit and closed-field circuit of the two types of magnetic attachments. The flux densities on the surfaces of MAGNEDISC 800 (MD800) and MAGFIT EX600W (EX600) magnetic attachments under open-field circuit were 275.0 mT and 147.0 mT respectively. The flux leakages under closed-field circuit were smaller than those under open-field circuit. The respective flux densities on the surfaces of MD800 and EX600 magnetic attachments decreased to 11.4 mT and 4.5 mT under closed-field circuit. The flux density around the magnetic attachment decreased as the distance from the surface of the attachment increased. When keeper and magnet slid laterally for a certain distance or when air gap existed between keeper and magnet, the flux leakage increased in comparison with that under closed-field circuit. Under the standard closed-field circuit, the two types of magnetic attachments achieved the largest retentive forces. The retentive forces of MD800 and EX600 magnetic attachments under the standard closed-field circuit were 6.20 N and 4.80 N respectively. The retentive forces decreased with the sliding distance or with the increase of air gap

  12. Relationships between nutrient enrichment, pleurocerid snail density and trematode infection rate in streams

    Science.gov (United States)

    Ciparis, Serena; Iwanowicz, Deborah D.; Voshell, J. Reese

    2013-01-01

    Summary 1. Nutrient enrichment is a widespread environmental problem in freshwater ecosystems. Eutrophic conditions caused by nutrient enrichment may result in a higher prevalence of infection by trematode parasites in host populations, due to greater resource availability for the molluscan first intermediate hosts. 2. This study examined relationships among land use, environmental variables indicating eutrophication, population density of the pleurocerid snail, Leptoxis carinata, and trematode infections. Fifteen study sites were located in streams within the Shenandoah River catchment (Virginia, U.S.A.), where widespread nutrient enrichment has occurred. 3. Snail population density had a weak positive relationship with stream water nutrient concentration. Snail population density also increased as human activities within stream catchments increased, but density did not continue to increase in catchments where anthropogenic disturbance was greatest. 4. Cercariae from five families of trematodes were identified in L. carinata, and infection rate was generally low (snail population density, nutrients or land use. 5. There were statistically significant but weak relationships between the prevalence of infection by two trematode families and physical and biological variables. The prevalence of Notocotylidae was positively related to water depth, which may be related to habitat use by definitive hosts. Prevalence of Opecoelidae had a negative relationship with orthophosphate concentration and a polynomial relationship with chlorophyll a concentration. Transmission of Opecoelid trematodes between hosts may be inhibited by eutrophic conditions. 6. Leptoxis carinata appears to be a useful species for monitoring the biological effects of eutrophication and investigating trematode transmission dynamics in lotic systems.

  13. Constraining annual and seasonal radon-222 flux density from the Southern Ocean using radon-222 concentrations in the boundary layer at Cape Grim

    Directory of Open Access Journals (Sweden)

    W. Zahorowski

    2013-02-01

    Full Text Available Radon concentrations measured between 2001 and 2008 in marine air at Cape Grim, a baseline site in north-western Tasmania, are used to constrain the radon flux density from the Southern Ocean. A method is described for selecting hourly radon concentrations that are least perturbed by land emissions and dilution by the free troposphere. The distribution of subsequent radon flux density estimates is representative of a large area of the Southern Ocean, an important fetch region for Southern Hemisphere climate and air pollution studies. The annual mean flux density (0.27 mBq m−2 s−1 compares well with the mean of the limited number of spot measurements previously conducted in the Southern Ocean (0.24 mBq m−2 s−1, and to some spot measurements made in other oceanic regions. However, a number of spot measurements in other oceanic regions, as well as most oceanic radon flux density values assumed for modelling studies and intercomparisons, are considerably lower than the mean reported here. The reported radon flux varies with seasons and, in summer, with latitude. It also shows a quadratic dependence on wind speed and significant wave height, as postulated and measured by others, which seems to support our assumption that the selected least perturbed radon concentrations were in equilibrium with the oceanic radon source. By comparing the least perturbed radon observations in 2002–2003 with corresponding ‘TransCom’ model intercomparison results, the best agreement is found when assuming a normally distributed radon flux density with σ=0.075 mBq m−2 s−1.

  14. Wide Dynamic Range Multiband Infrared Radiometer for In-Fire Measurements of Wildland Fire Radiant Flux Density

    Science.gov (United States)

    Kremens, R.; Dickinson, M. B.; Hardy, C.; Skowronski, N.; Ellicott, E. A.; Schroeder, W.

    2016-12-01

    We have developed a wide dynamic range (24-bit) data acquisition system for collection of radiant flux density (FRFD) data from wildland fires. The data collection subsystem was designed as an Arduino `shield' and incorporates a 24-bit analog-to-digital converter, precision voltage reference, real time clock, microSD card interface, audible annuciator and interface for various digital communication interfaces (RS232, I2C, SPI, etc.). The complete radiometer system consists of our custom-designed `shield', a commercially available Arduino MEGA computer circuit board and a thermopile sensor -amplifier daughter board. Software design and development is greatly assisted by the availability of a library of public-domain, user-implemented software. The daughter board houses a 5-band radiometer using thermopiles designed for this experiment (Dexter Research Corp., Dexter, MI) to allow determination of the total FRFD from the fire (using a wide band thermopile with a KRS-5 window, 0.1 - 30 um), the FRFD as would be received by an orbital asset like MODIS (3.95 um center wavelength (CWL) and 10.95 CWL, corresponding to MODIS bands 21/22 and 31, respectively) and wider bandpass (0.1-5.5 um and 8-14 um) corresponding to the FRFD recorded by `MWIR' and `LWIR' imaging systems. We required a very wide dynamic range system in order to be able to record the flux density from `cold' ground before the fire, through the `hot' flaming combustion stage, to the `cool' phase after passage of the fire front. The recording dynamic range required (with reasonable resolution at the lowest temperatures) is on the order of 106, which is not currently available in commercial instrumentation at a price point, size or feature set that is suitable for wildland fire investigations. The entire unit, along with rechargeable battery power supply is housed in a fireproof aluminum chassis box, which is then mounted on a mast at a height of 5 - 7 m above the fireground floor. We will report initial

  15. The relationship between fission track length and track density in apatite

    International Nuclear Information System (INIS)

    Laslett, G.M.; Gleadow, A.J.W.; Duddy, I.R.

    1984-01-01

    Fission track dating is based upon an age equation derived from a random line segment model for fission tracks. This equation contains the implicit assumption of a proportional relationship between the true mean length of fission tracks and their track density in an isotropic medium. Previous experimental investigation of this relationship for both spontaneous and induced tracks in apatite during progressive annealment model in an obvious fashion. Corrected equations relating track length and density for apatite, an anisotropic mineral, show that the proportionality in this case is between track density and a length factor which is a generalization of the mean track length combining the actual length and crystallographic orientation of the track. This relationship has been experimentally confirmed for induced tracks in Durango apatite, taking into account bias in sampling of the track lengths, and the effect of the bulk etching velocity. (author)

  16. The relationship between panoramic radiomorphometric indices of the mandible and calcaneus bone mineral density.

    Science.gov (United States)

    Jagelaviciene, Egle; Kubilius, Ricardas; Krasauskiene, Aurelija

    2010-01-01

    The aim of the study was to determine the relationship between bone mineral density in the calcaneus measured using the dual x-ray and laser osteodensitometry technique and bone mineral density in the mandible calculated using the panoramic radiomorphometric indices obtained by applying linear measurements in panoramic radiograms of postmenopausal women. The participants of this study were postmenopausal women (n=129) aged 50 and more. The subjects underwent panoramic radiography of the mandibles, followed by the calculation of the panoramic radiomorphometric indices indicating bone mineral density of the mandible. The dual x-ray and laser osteodensitometer DXL Calscan were used for the measurements of bone mineral density in the calcaneus. Statistical analysis was preformed to find the relationship between bone mineral density measurements in the two anatomically different bones. Following the diagnostic criteria for osteoporosis recommended by the World Health Organization (1994), the subjects were distributed according to the calcaneus bone mineral density T-score into the normal bone mineral density (group 1), osteopenia (group 2), and osteoporosis (group 3) groups. Mean bone mineral density in the calcaneus in the general studied population was 0.38+/-0.07; the mean value of bone mineral density of the calcaneus in the group 1 (n=34) was 0.47+/-0.04 (g/cm(2)), in the group 2 (n=65) was 0.37+/-0.03 (g/cm(2)), and in the group 2 (n=30) was 0.29+/-0.03 (g/cm(2)). Differences in bone mineral density between the groups were determined using the analysis of variance (ANOVA) F=285.31; df=2; Ppanoramic mandibular index and bone mineral density in the calcaneus (r=0.397, Ppanoramic radiography reflect general changes in the mineralization of these bones, characteristic of the postmenopausal period.

  17. Neutron metrology in the L.F.R. Neutron flux density spectrum in the inner graphite reflector of the L.F.R

    International Nuclear Information System (INIS)

    Zsolnay, E.M.

    1979-01-01

    The neutron spectrum in the vertical central plug of the Low Flux Reactor has been determined experimentally. Sets of activation and fission detectors have been irradiated, and the neutron spectrum has been unfolded with aid of 3 special computer programs SAND-II, RFSP-JUEL and CRYSTAL BALL. Using these 3 programs calculations are made on the improvement ratio, which is defined as the ratio of the variance of the input flux density to that of the output flux density. A Monte Carlo error analysis is made to examine the quality of the 3 solution spectra. The results obtained with the different computer codes were compared, and showed a general agreement. The experiment confirmed that the shape of the spectrum in the intermediate energy region is near the 1/E pattern. (author)

  18. User's guide for SLWDN9, a code for calculating flux-surfaced-averaging of alpha densities, currents, and heating in non-circular tokamaks

    International Nuclear Information System (INIS)

    Hively, L.M.; Miley, G.M.

    1980-03-01

    The code calculates flux-surfaced-averaged values of alpha density, current, and electron/ion heating profiles in realistic, non-circular tokamak plasmas. The code is written in FORTRAN and execute on the CRAY-1 machine at the Magnetic Fusion Energy Computer Center

  19. The epoxy resin variation effect on microstructure and physical properties to improve bonded NdFeB flux magnetic density

    International Nuclear Information System (INIS)

    Rusnaeni, N.; Sarjono, Priyo; Muljadi; Noer, Nasrudin

    2016-01-01

    NdFeB magnets have been fabricated from a mixture of powder NdFeB (MPQ-B+) and epoxy resins (ER) with a variation of 0% wt, 2% wt, 4% wt and 6% wt. The pellets samples were made by pressing 4 tons of the mixture powder at room temperature before curing at 100°C for 1 hour. The SEM-EDX results showed the microstructure with ER were evenly smeared the NdFeB magnetic particles due to higher percent C and lower transition metals value. Sample with 2% wt epoxy resin was able to achieve the highest density of 5.35 g/cm 3 and the highest magnetic flux of 2121 Gauss. The magnetic properties characterization using the permagraph indicates that the sample pellets with 2% wt epoxy resin has a value of remanence (Br) = 4.92 kG, coercivity (Hc) = 7.76 kOe, and energy product (Bhmax) = 4.58 MGOe. Despite low remanence value in the pellet samples, the resistance to demagnetization value was still acceptable. (paper)

  20. The epoxy resin variation effect on microstructure and physical properties to improve bonded NdFeB flux magnetic density

    Science.gov (United States)

    Rusnaeni, N.; Sarjono, Priyo; Muljadi; Noer, Nasrudin

    2016-11-01

    NdFeB magnets have been fabricated from a mixture of powder NdFeB (MPQ-B+) and epoxy resins (ER) with a variation of 0% wt, 2% wt, 4% wt and 6% wt. The pellets samples were made by pressing 4 tons of the mixture powder at room temperature before curing at 100°C for 1 hour. The SEM-EDX results showed the microstructure with ER were evenly smeared the NdFeB magnetic particles due to higher percent C and lower transition metals value. Sample with 2% wt epoxy resin was able to achieve the highest density of 5.35 g/cm3 and the highest magnetic flux of 2121 Gauss. The magnetic properties characterization using the permagraph indicates that the sample pellets with 2% wt epoxy resin has a value of remanence (Br) = 4.92 kG, coercivity (Hc) = 7.76 kOe, and energy product (Bhmax) = 4.58 MGOe. Despite low remanence value in the pellet samples, the resistance to demagnetization value was still acceptable.

  1. Real-time visualization of magnetic flux densities for transcranial magnetic stimulation on commodity and fully immersive VR systems

    Science.gov (United States)

    Kalivarapu, Vijay K.; Serrate, Ciro; Hadimani, Ravi L.

    2017-05-01

    Transcranial Magnetic Stimulation (TMS) is a non-invasive procedure that uses time varying short pulses of magnetic fields to stimulate nerve cells in the brain. In this method, a magnetic field generator ("TMS coil") produces small electric fields in the region of the brain via electromagnetic induction. This technique can be used to excite or inhibit firing of neurons, which can then be used for treatment of various neurological disorders such as Parkinson's disease, stroke, migraine, and depression. It is however challenging to focus the induced electric field from TMS coils to smaller regions of the brain. Since electric and magnetic fields are governed by laws of electromagnetism, it is possible to numerically simulate and visualize these fields to accurately determine the site of maximum stimulation and also to develop TMS coils that can focus the fields on the targeted regions. However, current software to compute and visualize these fields are not real-time and can work for only one position/orientation of TMS coil, severely limiting their usage. This paper describes the development of an application that computes magnetic flux densities (h-fields) and visualizes their distribution for different TMS coil position/orientations in real-time using GPU shaders. The application is developed for desktop, commodity VR (HTC Vive), and fully immersive VR CAVETM systems, for use by researchers, scientists, and medical professionals to quickly and effectively view the distribution of h-fields from MRI brain scans.

  2. Alternating steady state free precession for estimation of current-induced magnetic flux density: A feasibility study.

    Science.gov (United States)

    Lee, Hyunyeol; Jeong, Woo Chul; Kim, Hyung Joong; Woo, Eung Je; Park, Jaeseok

    2016-05-01

    To develop a novel, current-controlled alternating steady-state free precession (SSFP)-based conductivity imaging method and corresponding MR signal models to estimate current-induced magnetic flux density (Bz ) and conductivity distribution. In the proposed method, an SSFP pulse sequence, which is in sync with alternating current pulses, produces dual oscillating steady states while yielding nonlinear relation between signal phase and Bz . A ratiometric signal model between the states was analytically derived using the Bloch equation, wherein Bz was estimated by solving a nonlinear inverse problem for conductivity estimation. A theoretical analysis on the signal-to-noise ratio of Bz was given. Numerical and experimental studies were performed using SSFP-FID and SSFP-ECHO with current pulses positioned either before or after signal encoding to investigate the feasibility of the proposed method in conductivity estimation. Given all SSFP variants herein, SSFP-FID with alternating current pulses applied before signal encoding exhibits the highest Bz signal-to-noise ratio and conductivity contrast. Additionally, compared with conventional conductivity imaging, the proposed method benefits from rapid SSFP acquisition without apparent loss of conductivity contrast. We successfully demonstrated the feasibility of the proposed method in estimating current-induced Bz and conductivity distribution. It can be a promising, rapid imaging strategy for quantitative conductivity imaging. © 2015 Wiley Periodicals, Inc.

  3. Simulation of Field Dependence of Critical Current Densities of Bulk High Tc Superconducting Materials regarding Thermally Activated Flux Motion

    Science.gov (United States)

    Santosh, M.; Naik, S. Pavan Kumar; Koblischka, M. R.

    2017-07-01

    In the upcoming generation, bulk high temperature superconductors (HTS) will play a crucial and a promising role in numerous industrial applications ranging from Maglev trains to magnetic resonance imaging, etc. Especially, the bulk HTS as permanent magnets are suitable due to the fact that they can trap magnetic fields being several orders of magnitude higher than those of the best hard ferromagnets. The bulk HTS LREBa2Cu3O7-δ (LREBCO or LRE-123, LRE: Y, Gd, etc.,) materials could obtain very powerful compact superconducting super-magnets, which can be operated at the cheaper liquid nitrogen temperature or below due to higher critical temperatures (i.e., ∼90 K). As a result, the new advanced technology can be utilized in a more attractive manner for a variety of technological and medical applications which have the capacity to revolutionize the field. An understanding of the magnetic field dependence of the critical current density (J c(H)) is important to develop better adapted materials. To achieve this goal, a variety of Jc (H) behaviours of bulk LREBCO samples were modelled regarding thermally activated flux motion. In essence, the Jc (H) curves follows a certain criterion where an exponential model is applied. However, to fit the complete Jc (H) curve of the LRE-123 samples an unique model is necessary to explain the behavior at low and high fields. The modelling of the various superconducting materials could be understood in terms of the pinning mechanisms.

  4. [Relationships among Cyrtotrachelus buqueti larval density and wormhole number and bamboo shoot damage degree].

    Science.gov (United States)

    Yang, Yao-Jun; Wang, Shu-Fang; Gong, Jia-Wen; Liu, Chao; Mu, Chi; Qin, Hong

    2009-08-01

    In August of 2007 and 2008, a field investigation was made to study the relationships among Cyrtotrachelus buqueti larval density and wormhole number and bamboo shoot damage degree in Sichuan Province. The three pairs of variables, i. e., C. buqueti larval density and wormhole number, C. buqueti larval density and bamboo shoot damage degree, and C. buqueti wormhole number and bamboo shoot damage degree, fitted cubic equations well, with the correlation coefficients at P = 0.001. Based on these mathematical models, the forecast tables for C. buqueti larval density and bamboo shoot damage degree were established, and the thresholds of C. buqueti larval density and wormhole number were 0.13 and 0.40 individual per bamboo, respectively.

  5. Plant lighting system with five wavelength-band light-emitting diodes providing photon flux density and mixing ratio control

    Directory of Open Access Journals (Sweden)

    Yano Akira

    2012-11-01

    Full Text Available Abstract Background Plant growth and development depend on the availability of light. Lighting systems therefore play crucial roles in plant studies. Recent advancements of light-emitting diode (LED technologies provide abundant opportunities to study various plant light responses. The LED merits include solidity, longevity, small element volume, radiant flux controllability, and monochromaticity. To apply these merits in plant light response studies, a lighting system must provide precisely controlled light spectra that are useful for inducing various plant responses. Results We have developed a plant lighting system that irradiated a 0.18 m2 area with a highly uniform distribution of photon flux density (PFD. The average photosynthetic PFD (PPFD in the irradiated area was 438 micro-mol m–2 s–1 (coefficient of variation 9.6%, which is appropriate for growing leafy vegetables. The irradiated light includes violet, blue, orange-red, red, and far-red wavelength bands created by LEDs of five types. The PFD and mixing ratio of the five wavelength-band lights are controllable using a computer and drive circuits. The phototropic response of oat coleoptiles was investigated to evaluate plant sensitivity to the light control quality of the lighting system. Oat coleoptiles irradiated for 23 h with a uniformly distributed spectral PFD (SPFD of 1 micro-mol m–2 s–1 nm–1 at every peak wavelength (405, 460, 630, 660, and 735 nm grew almost straight upwards. When they were irradiated with an SPFD gradient of blue light (460 nm peak wavelength, the coleoptiles showed a phototropic curvature in the direction of the greater SPFD of blue light. The greater SPFD gradient induced the greater curvature of coleoptiles. The relation between the phototropic curvature (deg and the blue-light SPFD gradient (micro-mol m–2 s–1 nm–1 m–1 was 2 deg per 1 micro-mol m–2 s–1 nm–1 m–1. Conclusions The plant lighting system, with a computer with a

  6. THE RELATIONSHIP BETWEEN BULK-DENSITY AND COMPACTIBILITY OF LACTOSE GRANULATIONS

    NARCIS (Netherlands)

    ZUURMAN, K; RIEPMA, KA; BOLHUIS, GK; VROMANS, H; LERK, CF

    1994-01-01

    The relationship between the bulk density and the compactibility of lactose granulations was studied. The granulations were prepared from different alpha-lactose monohydrate and roller dried beta-lactose powders by wet granulation, using different techniques with only water as a binder, or by

  7. Growth, temperature and density relationships of North Sea cod ( Gadus morhua )

    DEFF Research Database (Denmark)

    Rindorf, Anna; Jensen, Henrik; Schrum, Corinna

    2008-01-01

    This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related to temper...

  8. Productivity affects the density-body mass relationship of soil fauna communities

    NARCIS (Netherlands)

    Comor, V.N.R.; Thakur, M.P.; Berg, M.P.; Bie, de S.; Prins, H.H.T.; Langevelde, van F.

    2014-01-01

    The productivity of ecosystems and their disturbance regime affect the structure of animal communities. However, it is not clear which trophic levels benefit the most from higher productivity or are the most impacted by disturbance. The density-body mass (DBM) relationship has been shown to reflect

  9. Maximum size-density relationships for mixed-hardwood forest stands in New England

    Science.gov (United States)

    Dale S. Solomon; Lianjun Zhang

    2000-01-01

    Maximum size-density relationships were investigated for two mixed-hardwood ecological types (sugar maple-ash and beech-red maple) in New England. Plots meeting type criteria and undergoing self-thinning were selected for each habitat. Using reduced major axis regression, no differences were found between the two ecological types. Pure species plots (the species basal...

  10. Violence Victimization of Young Men in Heterosexual Relationships: Does Alcohol Outlet Density Influence Outcomes?

    Science.gov (United States)

    Waller, Martha W.; Iritani, Bonita J.; Flewelling, Robert L.; Christ, Sharon L.; Halpern, Carolyn Tucker; Moracco, Kathryn E.

    2012-01-01

    This study examined whether alcohol outlet density is associated with male physical and sexual victimization by a female partner. Data were from the National Longitudinal Study of Adolescent Health (Add Health). A total of 3,179 young adult men identified a current heterosexual relationship and had complete intimate partner violence (IPV) victimization data. Almost 16% of this sample reported being the victim of physical only IPV in their relationship over the previous 12 months; an additional 6.4% were victims of sexual only or sexual and physical IPV. Multivariate analyses indicated high alcohol outlet density was associated with greater odds of experiencing physical IPV only (odds ratio [OR] = 2.07). Heavy drinkers experienced increased odds of physical and sexual IPV victimization. Alcohol outlet density should be addressed in prevention efforts. PMID:22978073

  11. Density-body mass relationships: Inconsistent intercontinental patterns among termite feeding-groups

    Science.gov (United States)

    Dahlsjö, Cecilia A. L.; Parr, Catherine L.; Malhi, Yadvinder; Meir, Patrick; Rahman, Homathevi; Eggleton, Paul

    2015-02-01

    Allometric relationships are useful for estimating and understanding resource distribution in assemblages with species of different masses. Damuth's law states that body mass scales with population density as M-0.75, where M is body mass and -0.75 is the slope. In this study we used Damuth's law (M-0.75) as a null hypothesis to examine the relationship between body mass and population density for termite feeding-groups in three different countries and regions (Cameroon, West Africa; Peru South America; and Malaysia SE Asia). We found that none of the feeding-groups had a relationship where M-0.75 while the data suggested that population density-body mass relationships for true soil-feeding termites in Cameroon (M2.7) and wood-feeding termites in Peru (M1.5) were significantly different from the expected values given by Damuth's law. The dominance of large-bodied true soil-feeding termites in Cameroon and the absence of fungus-growing termites from Peru suggest that these allometric patterns are due to heterogeneities in termite biogeographical evolution. Additionally, as these feeding-groups have higher population density than expected by their body masses it may be suggested that they also have a higher energy throughput than expected. The results presented here may be used to gain further understanding of resource distribution among termite feeding-groups across regions and an insight into the importance of evolutionary history and biogeography on allometric patterns. Further understanding of population density-body mass relationships in termite feeding-groups may also improve understanding of the role these feeding-groups play in ecosystem processes in different regions.

  12. Assessing the thermal dissipation sap flux density method for monitoring cold season water transport in seasonally snow-covered forests.

    Science.gov (United States)

    Chan, Allison M; Bowling, David R

    2017-07-01

    Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activity during the cold season and the winter-spring and fall-winter transitions. Although sap flow techniques have been widely used, cold season results are generally not reported. Here we examine the feasibility of using the Granier thermal dissipation (TD) sap flux density method to monitor transpiration and dormancy of evergreen conifers during the cold season. We conducted a laboratory experiment which demonstrated that the TD method reliably detects xylem water transport (when it occurs) both at near freezing temperature and at low flow rate, and that the sensors can withstand repeated freeze-thaw events. However, the dependence between sensor output and water transport rate in these experiments differed from the established TD relation. In field experiments, sensors installed in two Abies forests lasted through two winters and a summer with low failure. The baseline (no-flow) sensor output varied considerably with temperature during the cold season, and a new baseline algorithm was developed to accommodate this variation. The Abies forests differed in elevation (2070 and 2620 m), and there was a clear difference in timing of initiation and cessation of transpiration between them. We conclude that the TD method can be reliably used to examine water transport during cold periods with associated low flow conditions. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Study and Simulation of the Density of the Incident Solar Flux on the Walls of a Building in Adrar, Algeria

    Directory of Open Access Journals (Sweden)

    A. Oudrane

    2017-10-01

    Full Text Available In this work, we studied the effect of external climatic conditions on the evolution of the daily solar flux incident on the walls of a building located at Adrar region in the South of Algeria. This building is designed for heating or air conditioning applications. Numerical simulations allowed to compare the variation of the incident solar flux over a full day on the south, east, north and west walls of the building to the values of the solar flux on a horizontal wall (the outer ceiling. The horizontal global solar flux is calculated using a Gaussian sinusoidal function. The simulations were carried out in the case of a building located in a desert zone. The results of the numerical simulation showed the effect of the orientation of the building on the evolution of the incident daily solar flux.

  14. Investigations on structure–property relationships of activated flux TIG weldments of super-duplex/austenitic stainless steels

    International Nuclear Information System (INIS)

    Devendranath Ramkumar, K.; Bajpai, Ankur; Raghuvanshi, Shubham; Singh, Anshuman; Chandrasekhar, Aditya; Arivarasu, M.; Arivazhagan, N.

    2015-01-01

    This research work articulated the effect of SiO 2 flux assisted tungsten inert gas (TIG) welding on the microstructure and mechanical properties of marine grade stainless steel weldments, such as super-duplex stainless steel (UNS S32750) and austenitic stainless steel (AISI 316L). The studies showed that the use of flux decreased the heat input required to obtain complete penetration. Microstructure studies revealed the presence of ferrite at the heat affected zone of AISI 316L and the fusion zone which obviated the hot cracking tendency. Tensile studies corroborated that the joint strength was sufficiently greater than that of the parent metals. Impact toughness slightly impoverished owing to the presence of large platelets of Widmanstätten austenite in the fusion zone. The study also explored the structure–property relationships of the flux assisted weldments using the combined techniques of optical and scanning electron microscopy analysis. Owing to the better metallurgical and mechanical properties, this study recommends the use of SiO 2 flux for joining the dissimilar metals involving austenitic and super-duplex stainless steels

  15. Investigations on structure–property relationships of activated flux TIG weldments of super-duplex/austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Devendranath Ramkumar, K., E-mail: ramdevendranath@gmail.com; Bajpai, Ankur; Raghuvanshi, Shubham; Singh, Anshuman; Chandrasekhar, Aditya; Arivarasu, M.; Arivazhagan, N.

    2015-06-25

    This research work articulated the effect of SiO{sub 2} flux assisted tungsten inert gas (TIG) welding on the microstructure and mechanical properties of marine grade stainless steel weldments, such as super-duplex stainless steel (UNS S32750) and austenitic stainless steel (AISI 316L). The studies showed that the use of flux decreased the heat input required to obtain complete penetration. Microstructure studies revealed the presence of ferrite at the heat affected zone of AISI 316L and the fusion zone which obviated the hot cracking tendency. Tensile studies corroborated that the joint strength was sufficiently greater than that of the parent metals. Impact toughness slightly impoverished owing to the presence of large platelets of Widmanstätten austenite in the fusion zone. The study also explored the structure–property relationships of the flux assisted weldments using the combined techniques of optical and scanning electron microscopy analysis. Owing to the better metallurgical and mechanical properties, this study recommends the use of SiO{sub 2} flux for joining the dissimilar metals involving austenitic and super-duplex stainless steels.

  16. Bone density relationship of mandible and cervical vertebrae in panoramic radiography

    International Nuclear Information System (INIS)

    Nah, Kyung Soo

    2000-01-01

    Upper cervical vertebrae are commonly imaged together with the jaw bones in panoramic radiography. There have been many studies investigating the possible role of mandible as an indicator of osteoporosis. But the result doesn't show unanimity. This study measured bone densities of mandible and second and third cervical vertebrae to find out any relationship between these two areas. These results may contribute in panorama being used as a screening method in detecting possible osteoporotic patient. Randomly selected 226 digitized panoramic images with cervical vertebrae shadows from 156 dental patients between 5 to 80 years of age were used. And the bone densities of second and third cervical vertebrae, apical areas of first and second mandibular molars and interdental areas were measured. The bone density measurements were restricted to the cancellous bone and the average and standard deviations and paired t-tests were done to each measurements. All the measurements were statistically significantly related. The best relationship was found between the third cervical vertebrae and first and second mandibular apical areas. The average and standard deviations of the measured bone density ratios of these areas were 1.20 ± 0.45 and 1.34 ± 0.48 each. Patients whose panoramic bone density of the third cervical vertebrae are much below those of mandibular first or second molar apical areas may have osteoporosis.

  17. The relationship between bone mineral density and adipose tissue of postmenopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Hwa [Dept. of Radiology, HwaMyeong Iisin christian Hospital, Busan (Korea, Republic of); Kim, Jung Hoon [Dept. of Radiological Science, Catholic University of Pusan, Busan (Korea, Republic of); Im, In Chul [Dept. of Radiological Science, Dong Eui University, Busan (Korea, Republic of)

    2017-06-15

    Postmenopausal women are at increased risk for osteoporosis and obesity due to changes in hormones. The relationship between osteoporosis and body weight is known, and its relation with body fat mass is discussed. The purpose of this study was to evaluate the bone mineral density(BMD) changes of epicardial adipose tissue(EAT) and abdominal subcutaneous fat. The subjects of this study were 160 postmenopausal women who underwent BMD and echocardiography. The thickness of the epicardial adipose tissue was measured in three sections and the BMD were meassured according to the diagnostic criteria. The results of this study that age increase the risk of osteoporosis increases, and as the weight and BMI decrease, the risk of osteoporosis increases(p<0.05). The relationship between changes in bone mineral density and adipose tissue in postmenopausal women, increased epicardial adipose tissue was negatively correlated with the bone mineral density(p<0.05). conversely, increased abdominal subcutaneous fat thickness was positively correlated with bone mineral density(p<0.05). In other words, the effect of bone mineral density on the location of adipose tissue was different. If Echocardiography is used to periodically examine changes in the thickness of the epicardial adipose tissue, it may be prevented before proceeding to osteoporosis.

  18. Individual-area relationship best explains goose species density in wetlands.

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    Full Text Available Explaining and predicting animal distributions is one of the fundamental objectives in ecology and conservation biology. Animal habitat selection can be regulated by top-down and bottom-up processes, and is mediated by species interactions. Species varying in body size respond differently to top-down and bottom-up determinants, and hence understanding these allometric responses to those determinants is important for conservation. In this study, using two differently sized goose species wintering in the Yangtze floodplain, we tested the predictions derived from three different hypotheses (individual-area relationship, food resource and disturbance hypothesis to explain the spatial and temporal variation in densities of two goose species. Using Generalized Linear Mixed Models with a Markov Chain Monte Carlo technique, we demonstrated that goose density was positive correlated with patch area size, suggesting that the individual area-relationship best predicts differences in goose densities. Moreover, the other predictions, related to food availability and disturbance, were not significant. Buffalo grazing probably facilitated greater white-fronted geese, as the number of buffalos was positively correlated to the density of this species. We concluded that patch area size is the most important factor determining the density of goose species in our study area. Patch area size is directly determined by water levels in the Yangtze floodplain, and hence modifying the hydrological regimes can enlarge the capacity of these wetlands for migratory birds.

  19. Accumulation of phosphorus in coastal marine sediments: relationship to benthic and diffusive fluxes

    Directory of Open Access Journals (Sweden)

    Rocio Ponce

    2010-11-01

    Full Text Available Sedimentary phosphorus was characterized in sediment cores from 3 coastal ecosystems of the Gulf of Cadiz. High spatial variability was observed in total phosphorus (from 445 to 20291 μg g.sed-1 and in the other phosphorus phases studied. This variability correlates with the proximity of the 10 sampling stations to sources of urban and/or industrial effluent in the zone. The benthic and diffusive fluxes were measured concurrently with sediment collection at these stations. The measured values of benthic fluxes range between –14 and 6 mmol m-2 d-1. Generally, stations that showed increased interstitial phosphate concentrations with increasing depth were characterized by positive values in phosphate benthic fluxes and by high percentages of reactive forms of sedimentary phosphorus. Negative benthic fluxes were associated with stations receiving more anthropogenic matter, which showed progressively decreasing phosphate concentrations in the interstitial water with depth. In these anthropogenic areas, the non-reactive forms of phosphorus (those associated with ferric oxyhydroxide and authigenic carbonate fluorapatite are abundant, and reach values exceeding 75% of total phosphorus in sediment.

  20. Small compression modulus of the flux line lattice and large density fluctuations at high fields may explain peak effect

    International Nuclear Information System (INIS)

    Brandt, E.H.

    1976-01-01

    The elastic properties of the flux line lattice in Type II superconductors as calculated from the Ginsburg-Landau theory are discussed. They are non-local on a length scale much larger than the flux line distance and divergent at Hsub(c2). The compression modulus may become much smaller than its long-wavelength limit, B 2 /4π, and if the deformation is not homogeneous, at Hsub(c2) the modulus vanishes as (Hsub(c2) - B) 2 . At arbitrary induction the compression modulus of strain waves with wavelengths of several flux line distances is of the order of the (small) shear modulus. (author)

  1. Temperature and density characteristics of the Helicity Injected Torus-II spherical tokamak indicating closed flux sustainment using coaxial helicity injection

    Science.gov (United States)

    Hamp, W. T.; Jarboe, T. R.; Nelson, B. A.; O'Neill, R. G.; Raman, R.; Redd, A. J.; Stewart, B. T.; Mueller, D.

    2008-08-01

    The electron temperature and density profiles of plasmas in the Helicity Injected Torus [HIT-II: T. R. Jarboe et al., Phys. Plasmas 5, 1807 (1998)] experiment are measured by multipoint Thomson scattering (MPTS). The HIT-II device is a small low-aspect-ratio tokamak (major radius 0.3m, minor radius 0.2m, toroidal field of up to 0.5T), capable of inductive ohmic (OH) current drive, Coaxial Helicity Injection (CHI) current drive, or combinations of both. The temperature and density characteristics have been characterized by a ruby laser MPTS diagnostic at up to six locations within the plasma for a single diagnostic time per discharge. Observed hollow temperature profiles of CHI discharges are inconsistent with open flux only predictions for CHI and indicate a closed flux region during CHI current drive.

  2. Critical current density, irreversibility line, and flux creep activation energy in silver-sheathed Bi2Sr2Ca2Cu3Ox superconducting tapes

    International Nuclear Information System (INIS)

    Shi, D.; Wang, Z.; Sengupta, S.; Smith, M.; Goodrich, L.F.; Dou, S.X.; Liu, H.K.; Guo, Y.C.

    1992-08-01

    Transport data, magnetic hysteresis and flux creep activation energy experimental results are presented for silver-sheathed high-T c Bi 2 Sr 2 Ca 2 Cu 3 O x superconducting tapes. The 110 K superconducting phase was formed by lead doping in a Bi-Sr-Ca-Cu-0 system. The transport critical current density was measured at 4.0 K to be 0.7 x 10 5 A/cm 2 (the corresponding critical current is 74 A) at zero field and 1.6 x 10 4 A/cm 2 at 12 T for H parallel ab. Excellent grain alignment in the a-b plane was achieved by a short-melting method, which considerably improved the critical current density and irreversibility line. Flux creep activation energy as a function of current is obtained based on the magnetic relaxation measurements

  3. Relationship between lunar tidal enhancements in the equatorial electrojet and tropospheric eddy heat flux during stratospheric sudden warmings

    Science.gov (United States)

    Siddiqui, T. A.; Yamazaki, Y.; Stolle, C.; Lühr, H.; Matzka, J.

    2017-12-01

    A number of studies in recent years have reported about the lunar tidal enhancements in the equatorial electrojet (EEJ) from ground- and space-based magnetometer measurements during stratospheric sudden warming (SSW) events. In this study, we make use of the ground magnetometer recordings at Huancayo observatory in Peru for the years 1978 - 2013 to derive a relationship between the lunar tidal enhancements in the EEJ and tropospheric eddy heat fluxes at 100 hPa during the SSW events. Tropospheric eddy heat fluxes are used to quantify the amount of wave activity entering the stratosphere. Anomalously large upward wave activity is known to precede the polar vortex breakdown during SSWs. We make use of the superposed epoch analysis method to determine the temporal relations between lunar tidal enhancements and eddy heat flux anomalies during SSWs, in order to demonstrate the causal relationship between these two phenomena. We also compare the lunar tidal enhancements and eddy heat flux anomalies for vortex split and for vortex displaced SSWs. It is found that larger lunar tidal enhancements are recorded for vortex split events, as compared to vortex displaced events. This confirms earlier observation; larger heat flux anomalies are recorded during vortex split SSW events than the heat flux anomalies during vortex displaced SSW events. Further, the temporal relations of lunar tidal enhancements in the EEJ have been compared separately for both the QBO phases and with the phases of the moon with respect to the central epoch of SSWs by means of the superposed epoch analysis approach. The EEJ lunar tidal enhancements in the east phase of QBO are found to be larger than the lunar tidal enhancements in the west phase of QBO. The phase of moon relative to the central SSW epoch also affects the lunar tidal enhancement in the EEJ. It is found that the lunar tidal enhancements are significantly larger when the day of new or full moon lies near the central SSW epoch, as compared

  4. Azimuthal and radial variations in sap flux density and effects on stand-scale transpiration estimates in a Japanese cedar forest.

    Science.gov (United States)

    Shinohara, Yoshinori; Tsuruta, Kenji; Ogura, Akira; Noto, Fumikazu; Komatsu, Hikaru; Otsuki, Kyoichi; Maruyama, Toshisuke

    2013-05-01

    Understanding radial and azimuthal variation, and tree-to-tree variation, in sap flux density (Fd) as sources of uncertainty is important for estimating transpiration using sap flow techniques. In a Japanese cedar (Cryptomeria japonica D. Don.) forest, Fd was measured at several depths and aspects for 18 trees, using heat dissipation (Granier-type) sensors. We observed considerable azimuthal variation in Fd. The coefficient of variation (CV) calculated from Fd at a depth of 0-20 mm (Fd1) and Fd at a depth of 20-40 mm (Fd2) ranged from 6.7 to 37.6% (mean = 28.3%) and from 19.6 to 62.5% (mean = 34.6%) for the -azimuthal directions. Fd at the north aspect averaged for nine trees, for which azimuthal measurements were made, was -obviously smaller than Fd at the other three aspects (i.e., west, south and east) averaged for the nine trees. Fd1 averaged for the nine trees was significantly larger than Fd2 averaged for the nine trees. The error for stand-scale transpiration (E) estimates caused by ignoring the azimuthal variation was larger than that caused by ignoring the radial variation. The error caused by ignoring tree-to-tree variation was larger than that caused by ignoring both radial and azimuthal variations. Thus, tree-to-tree variation in Fd would be more important than both radial and azimuthal variations in Fd for E estimation. However, Fd for each tree should not be measured at a consistent aspect but should be measured at various aspects to make accurate E estimates and to avoid a risk of error caused by the relationship of Fd to aspect.

  5. The relationship between liquor outlet density and injury and violence in New Mexico.

    Science.gov (United States)

    Escobedo, Luis G; Ortiz, Melchor

    2002-09-01

    This study used an ecologic design based on data from 1990 to 1994 gathered from forensic, vital statistic, census, law enforcement and liquor licensing agencies to assess the relationship between liquor outlet density and alcohol-related health outcomes in New Mexico. Linear regression models show that suicide, alcohol-related crash, and alcohol-related crash fatality (adjusted for age, sex, and minority status) are significantly associated with liquor outlet density. Data also show that, compared with the first tertile, suicide and alcohol-related crash rates increase about 50% and the alcohol-related crash fatality rate two-fold with the third tertile of liquor outlet density. Greater availability of liquor outlets is associated with higher rates of suicide, alcohol-related crash, and alcohol-related crash fatality.

  6. The relationship between personal net energy use and the urban density of solar buildings

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, W.; Athienitis, A. [Concordia Univ., Montreal, PQ (Canada). Dept. of Building, Civil and Environmental Engineering; Kennedy, C. [Toronto Univ., ON (Canada). Dept. of Civil Engineering; Kesik, T. [Toronto Univ., ON (Canada). Faculty of Architecture Landscape and Design

    2009-06-15

    In order to promote sustainable development, urban areas should be planned in a manner to minimize energy use and greenhouse gas (GHG) emissions. This paper looked at housing energy, building-integrated solar energy collection, and personal transportation energy in an effort to quantitatively compare different housing forms and densities. The 3 housing forms used to establish trends in energy use as a function of housing density in Toronto were low-density detached homes, medium-density townhouses and high-density high-rises. This multi-disciplinary study proved the importance of collaboration between building designers and urban planners. The objective of the study was to quantify the importance of balancing transportation energy and solar energy availability for buildings, in the context of net operational energy use. It focused on the dichotomous relationship between the density of solar housing and household energy use. The following 2 scenarios were studied: (1) the base case in which average new home performance, average vehicle fleet, and nominal solar collector efficiency were examined, and (2) the efficient case in which energy efficiency measures and ground source heat pumps (GSHP) were added to the homes. The vehicle fleet was upgraded to plug-in hybrids and the solar collector efficiency was doubled. The results show that only when all systems are made to be extremely efficient does the low-density development result in lower net energy use. Therefore, this study emphasized the need to consider new housing developments in the context of their surroundings. The amount of solar energy available per person decreases approximately linearly as density increases. The results suggest that urban form should not be driven by solar energy availability alone, but rather the consideration of all major energy sources and sinks. 34 refs., 12 tabs., 4 figs.

  7. Relationship Between Collateral Status, Contrast Transit, and Contrast Density in Acute Ischemic Stroke.

    Science.gov (United States)

    Kawano, Hiroyuki; Bivard, Andrew; Lin, Longting; Spratt, Neil J; Miteff, Ferdinand; Parsons, Mark W; Levi, Christopher R

    2016-03-01

    Collateral circulation is recognized to influence the life expectancy of the ischemic penumbra in acute ischemic stroke. The best method to quantify collateral status on acute imaging is uncertain. We aimed to determine the relationship between visual collateral status, quantitative collateral assessments, baseline computed tomographic perfusion measures, and tissue outcomes on follow-up imaging. Sixty-six consecutive patients with acute ischemic stroke clinically eligible for recanalization therapy and with M1 or M2 middle cerebral artery occlusion were evaluated. We compared the visual collateral scoring with measures of contrast peak time delay and contrast peak density. We also compared these measures for their ability to predict perfusion lesion and infarct core volumes, final infarct, and infarct growth. Shorter contrast peak time delay (P=0.041) and higher contrast peak density (P=0.002) were associated with good collateral status. Shorter contrast peak time delay correlated with higher contrast peak density (β=-4.413; P=0.037). In logistic regression analysis after adjustment for age, sex, onset-computed tomographic time, and occlusion site, higher contrast peak density was independently associated with good collateral status (P=0.009). Multiple regression analysis showed that higher contrast peak density was an independent predictor of smaller perfusion lesion volume (P=0.029), smaller ischemic core volume (P=0.044), smaller follow-up infarct volume (P=0.005), and smaller infarct growth volume (P=0.010). Visual collateral status, contrast peak density, and contrast peak time delay were inter-related, and good collateral status was strongly associated with contrast peak density. Contrast peak density in collateral vessel may be an important factor in tissue fate in acute ischemic stroke. © 2016 American Heart Association, Inc.

  8. Relationship between Lineament Density Extraction from Satellite Image and Earthquake Distribution of Taungtonelone Area, Myanmar

    OpenAIRE

    MYINT, Soe; WON-IN, KRIT; TAKASHIMA, lsao; CHARUSIRI, Punya

    2007-01-01

    [ABSTRACT] We studied relationship between lineament density extraction from satellite image and earthquake distribution using remote sensing applications. The result of this study aim to set up a complete earthquake hazard Map. The selected area is located in the Taungtonelone area,northern Mynmar. Myanmar is an earth-quake-prone country. It lies in a major earthquake zone of the world called Mediterranean -Himalayan belt. As the major urban areas in Myanmar lie in earthquake prone zones, ea...

  9. Effects of Quantum Flux Density on Photosynthesis and Chloroplast Ultrastructure in Tissue-Cultured Plantlets and Seedlings of Liquidambar styraciflua L. towards Improved Acclimatization and Field Survival 1

    Science.gov (United States)

    Lee, Ni; Wetzstein, Hazel Y.; Sommer, Harry E.

    1985-01-01

    Liquidambar styraciflua L. seedlings and tissue-cultured plantlets were grown under high, medium, or low (315, 155, or 50 microeinsteins per square meter per second photosynthetically active radiation) quantum flux densities. Net photosynthesis, chlorophyll content, and chloroplast ultrastructure of leaves differentiated from these conditions were investigated. Seedling photosynthetic rates at light saturation were positively related to light pretreatments, being 6.44, 4.73, and 2.75 milligrams CO2 per square decimeter per hour for high, medium, and low light, respectively. Cultured plantlets under all light conditions had appreciably higher photosynthetic rates than noncultured seedlings; corresponding rates were 12.14, 13.55, and 11.36 milligrams CO2 per square decimeter per hour. Chlorophyll in seedlings and plantlets was significantly higher in low light-treated plants. Seedling leaves had chloroplasts with abundant starch regardless of light pretreatment. In high light, starch granules were predominant and associated with disrupted granal structure. Low light seedling chloroplasts had smaller starch grains and well-formed grana. In contrast, tissue culture-differentiated leaves were devoid of starch; grana were well organized in higher quantum flux density treatments, but disorganized at low flux densities. Images Figs. 2 to 7 PMID:16664297

  10. Human sleep EEG under the influence of pulsed radio frequency electromagnetic fields. Results from polysomnographies using submaximal high power flux densities.

    Science.gov (United States)

    Wagner, P; Röschke, J; Mann, K; Fell, J; Hiller, W; Frank, C; Grözinger, M

    2000-01-01

    Former exploratory investigations of sleep alterations due to global system for mobile communications (GSM) signals have shown a hypnotic and REM-suppressive effect under field exposure. This effect was observed in a first study using a power flux density of 0.5 W/m(2), and the same trend occurred in a second study with a power flux density of 0.2 W/m(2). For the present study, we applied a submaximal power flux density of 50 W/m(2). To investigate putative effects of radio frequency electromagnetic fields (EMFs) of cellular GSM phones on human sleep EEG pattern, all-night polysomnographies of 20 healthy male subjects both with and without exposure to a circularly polarized EMF (900 MHz, pulsed with a frequency of 217 Hz, pulse duration 577 microseconds) were recorded. The results showed no significant effect of the field application either on conventional sleep parameters or on sleep EEG power spectra. Copyright 2000 S. Karger AG, Basel.

  11. Effect of texture and grain size on the magnetic flux density and core loss of cold-rolled high silicon steel sheets

    Science.gov (United States)

    Qin, Jing; Yang, Ping; Mao, Weimin; Ye, Feng

    2015-11-01

    The effects of texture and grain size on the magnetic flux density and core loss (50-20 kHz) of 0.23 mm-thick cold-rolled high silicon steel sheets are investigated by means of electron back-scattered diffraction (EBSD), loss separation, and anisotropy parameter (ε) calculation. A model of the hysteresis loss coefficient kh considering average grain size and ε is established. The magnetic flux density at 800 A/m (B8) is closely related to the volume fraction of η-fiber-oriented grains, while the magnetic flux density at 5000 A/m (B50) is closely related to the volume fractions of γ- and λ-fiber-oriented grains in high silicon steel. The hysteresis loss of high silicon steel can be greatly reduced by increasing the grain size and optimizing the texture of the sheets. Although increases in frequencies decrease the effect of texture on core loss, the effect cannot be ignored. As annealing temperature and time increase, the relative difference in core loss between the rolling direction (RD) and the transverse direction (TD) is maintained at higher frequencies because of increases in grain size, decreases in γ texture, and maintenance of a strong η texture. Texture and grain size jointly affect the high-frequency core loss of high silicon steel.

  12. Simulation study of a geometric shape factor technique for estimating earth-emitted radiant flux densities from wide-field-of-view radiation measurements

    Science.gov (United States)

    Weaver, W. L.; Green, R. N.

    1980-01-01

    Geometric shape factors were computed and applied to satellite simulated irradiance measurements to estimate Earth emitted flux densities for global and zonal scales and for areas smaller than the detector field of view (FOV). Wide field of view flat plate detectors were emphasized, but spherical detectors were also studied. The radiation field was modeled after data from the Nimbus 2 and 3 satellites. At a satellite altitude of 600 km, zonal estimates were in error 1.0 to 1.2 percent and global estimates were in error less than 0.2 percent. Estimates with unrestricted field of view (UFOV) detectors were about the same for Lambertian and limb darkening radiation models. The opposite was found for restricted field of view detectors. The UFOV detectors are found to be poor estimators of flux density from the total FOV and are shown to be much better as estimators of flux density from a circle centered at the FOV with an area significantly smaller than that for the total FOV.

  13. DOES ALCOHOL OUTLET DENSITY MODERATE THE RELATIONSHIP BETWEEN LEVELS OF ALCOHOL USE AND CHILD PHYSICAL ABUSE?

    Science.gov (United States)

    Freisthler, Bridget; Wolf, Jennifer Price

    2016-01-01

    Objectives Parental alcohol use and alcohol outlet density are both associated with child abuse. Guided by alcohol availability theory, this paper examines whether alcohol outlet density moderates the relationship between parental alcohol use and child physical abuse. Methods A general population telephone survey of 3,023 parents or legal guardians 18 years or older was conducted across 50 California cities, while densities of alcohol outlets were measured for by zip code. Data were analyzed via overdispersed multilevel Poisson models. Results Ex-drinkers, light drinkers, and heavy drinkers use physical abuse more often than lifetime abstainers. Moderate drinking was not related to child physical abuse. Proportion of bars was negatively related to frequency of physical abuse. Moderating relationships between alcohol outlet density and drinking categories were found for all drinking patterns. Conclusion Different types of alcohol outlets may be differentially related to drinking patterns, indicating that the interaction of drinking patterns and the drinking environment may place children at greater risk for being physically abused. PMID:27642071

  14. Insights into plant size-density relationships from models and agricultural crops.

    Science.gov (United States)

    Deng, Jianming; Zuo, Wenyun; Wang, Zhiqiang; Fan, Zhexuan; Ji, Mingfei; Wang, Genxuan; Ran, Jinzhi; Zhao, Changming; Liu, Jianquan; Niklas, Karl J; Hammond, Sean T; Brown, James H

    2012-05-29

    There is general agreement that competition for resources results in a tradeoff between plant mass, M, and density, but the mathematical form of the resulting thinning relationship and the mechanisms that generate it are debated. Here, we evaluate two complementary models, one based on the space-filling properties of canopy geometry and the other on the metabolic basis of resource use. For densely packed stands, both models predict that density scales as M(-3/4), energy use as M(0), and total biomass as M(1/4). Compilation and analysis of data from 183 populations of herbaceous crop species, 473 stands of managed tree plantations, and 13 populations of bamboo gave four major results: (i) At low initial planting densities, crops grew at similar rates, did not come into contact, and attained similar mature sizes; (ii) at higher initial densities, crops grew until neighboring plants came into contact, growth ceased as a result of competition for limited resources, and a tradeoff between density and size resulted in critical density scaling as M(-0.78), total resource use as M(-0.02), and total biomass as M(0.22); (iii) these scaling exponents are very close to the predicted values of M(-3/4), M(0), and M(1/4), respectively, and significantly different from the exponents suggested by some earlier studies; and (iv) our data extend previously documented scaling relationships for trees in natural forests to small herbaceous annual crops. These results provide a quantitative, predictive framework with important implications for the basic and applied plant sciences.

  15. Insights into plant size-density relationships from models and agricultural crops

    Science.gov (United States)

    Deng, Jianming; Zuo, Wenyun; Wang, Zhiqiang; Fan, Zhexuan; Ji, Mingfei; Wang, Genxuan; Ran, Jinzhi; Zhao, Changming; Liu, Jianquan; Niklas, Karl J.; Hammond, Sean T.; Brown, James H.

    2012-01-01

    There is general agreement that competition for resources results in a tradeoff between plant mass, M, and density, but the mathematical form of the resulting thinning relationship and the mechanisms that generate it are debated. Here, we evaluate two complementary models, one based on the space-filling properties of canopy geometry and the other on the metabolic basis of resource use. For densely packed stands, both models predict that density scales as M−3/4, energy use as M0, and total biomass as M1/4. Compilation and analysis of data from 183 populations of herbaceous crop species, 473 stands of managed tree plantations, and 13 populations of bamboo gave four major results: (i) At low initial planting densities, crops grew at similar rates, did not come into contact, and attained similar mature sizes; (ii) at higher initial densities, crops grew until neighboring plants came into contact, growth ceased as a result of competition for limited resources, and a tradeoff between density and size resulted in critical density scaling as M−0.78, total resource use as M−0.02, and total biomass as M0.22; (iii) these scaling exponents are very close to the predicted values of M−3/4, M0, and M1/4, respectively, and significantly different from the exponents suggested by some earlier studies; and (iv) our data extend previously documented scaling relationships for trees in natural forests to small herbaceous annual crops. These results provide a quantitative, predictive framework with important implications for the basic and applied plant sciences. PMID:22586097

  16. Relationship of cancer incidence to terrestrial radiation and population density in Connecticut, 1935-1974

    International Nuclear Information System (INIS)

    Walter, S.D.; Meigs, J.W.; Heston, J.F.

    1986-01-01

    The relationship of cancer incidence to terrestrial radiation and population density was investigated. Cancer incidence was obtained using 40 years of age-standardized data from the Connecticut Tumor Registry, and environmental radiation was estimated using data from an airborne gamma radiation survey of the entire state. These variables were examined ecologically, using the 169 towns of the state as the analytic units in a weighted regression analysis. The study design involves a large population base in a state having relatively high terrestrial radiation exposure levels overall and reasonable variation in exposure between towns. For all cancer combined, only one of the eight sex-specific analyses by decade yielded a significant radiation regression coefficient, and this was negative. In the sex- and site-specific analyses, almost all the coefficients for radiation were not significantly different from zero. In contrast, significant positive relationships of cancer incidence with population density were found for all cancer, for cancer of the lung for both sexes, for stomach, colonic, and prostatic cancer for males, and for lymphomas, thyroid, breast, and ovarian cancer for females. Both the radiation and population density relationships were adjusted for socioeconomic status. Socioeconomic status was significantly negatively associated with stomach and lung cancer in males and with cervical cancer in females; it was also positively associated with lymphomas and breast cancer in females. A power calculation revealed that, despite the relatively large size of this study, there was only a small probability of detecting a radiation effect of the strength anticipated from previous estimates

  17. Can live tree size-density relationships provide a mechanism for predicting down and dead tree resources?

    Science.gov (United States)

    Christopher Woodall; James Westfall

    2009-01-01

    Live tree size-density relationships in forests have long provided a framework for understanding stand dynamics. There has been little examination of the relationship between the size-density attributes of live and standing/down dead trees (e.g., number and mean tree size per unit area, such information could help in large-scale efforts to estimate dead wood resources...

  18. The flux-weighted gravity-luminosity relationship of blue supergiant stars as a constraint for stellar evolution

    Science.gov (United States)

    Meynet, Georges; Kudritzki, Rolf-Peter; Georgy, Cyril

    2015-09-01

    Context. The flux-weighted gravity-luminosity relationship (FGLR) of blue supergiant stars (BSG) links their absolute magnitude to the spectroscopically determined flux-weighted gravity log g/T_text{eff ^4}. BSG are the brightest stars in the universe at visual light and the application of the FGLR has become a powerful tool for determining extragalactic distances. Aims: Observationally, the FGLR is a tight relationship with only small scatter. It is, therefore, ideal for using as a constraint for stellar evolution models. The goal of this work is to investigate whether stellar evolution can reproduce the observed FGLR and to develop an improved foundation for the FGLR as an extragalactic distance indicator. Methods: We used different grids of stellar models for initial masses between 9 and 40 M⊙ and for metallicities between Z = 0.002 and 0.014, with and without rotation, which were computed with various mass loss rates during the red supergiant phase. For each of these models, we discuss the details of post-main sequence evolution and construct theoretical FGLRs by means of population synthesis models that we then compare with the observed FGLR. Results: In general, the stellar evolution model FGLRs agree reasonably well with the observed one. There are, however, differences between the models, in particular with regard to the shape and width (scatter) in the flux-weighted gravity-luminosity plane. The best agreement is obtained with models that include the effects of rotation and assume that the large majority, if not all, of the observed BSG evolve toward the red supergiant phase and that only a few are evolving back from this stage. The effects of metallicity on the shape and scatter of the FGLR are small. Conclusions: The shape, scatter, and metallicity dependence of the observed FGLR are explained well by stellar evolution models. This provides a solid theoretical foundation for using this relationship as a robust extragalactic distance indicator.

  19. The relationship between maternal and child bone density in Nigerian children with and without nutritional rickets.

    Science.gov (United States)

    Bommersbach, T J; Fischer, P R; Pettifor, J M; Thacher, T D

    2018-02-27

    We found a positive relationship between bone density in Nigerian children with and without rickets and that of their mothers. After treatment, children with rickets had greater bone density than children without rickets, indicating that children genetically programmed to have greater bone density may have a higher risk of rickets. To determine the relationship between bone density in children with and without rickets and that of their mothers METHODS: Using an unmatched case-control design, forearm areal bone mineral density (aBMD) was measured in 52 and 135 Nigerian children with and without rickets and their mothers, respectively. We performed multivariate linear regression analyses to assess the relationship between maternal and child aBMD Z-scores. Forearm aBMD Z-scores in children were associated with maternal aBMD Z-scores at metaphyseal (effect estimate 0.23; 95% CI 0.08 to 0.37) and diaphyseal (effect estimate 0.16; 0.01 to 0.30) sites, after adjustment for rickets in the child, child's age and sex, height-for-age Z-score, and weight-for-age Z-score. In the adjusted model, rickets was inversely associated with child's aBMD Z-score at the diaphyseal site only (- 0.45, - 0.65 to - 0.24). The positive relationship between maternal and child aBMD Z-scores was marginally greater in children with rickets (slope 0.56, r = 0.47) than without rickets (slope 0.19, r = 0.20) at the diaphyseal site only (P = 0.06 for interaction) but not at the metaphyseal site (slopes 0.35 and 0.30, respectively, P = 0.48). After treatment with calcium for 6 months, metaphyseal aBMD Z-scores were greater in children with treated rickets (effect estimate 0.26; 95% CI 0.02 to 0.49) than in those without rickets. In Nigerian children with and without rickets, forearm aBMD Z-scores were positively associated with maternal aBMD Z-scores. Active rickets in the child marginally modified the relationship at the diaphyseal site only. After treatment, children with

  20. Market Competition and Density in Liver Transplantation: Relationship to Volume and Outcomes.

    Science.gov (United States)

    Adler, Joel T; Yeh, Heidi; Markmann, James F; Nguyen, Louis L

    2015-08-01

    Liver transplantation centers are unevenly distributed within the Donor Service Areas (DSAs) of the United States. This study assessed how market competition and liver transplantation center density are associated with liver transplantation volume within individual DSAs. We conducted a retrospective cohort study of 53,156 adult liver transplants in 45 DSAs with 110 transplantation centers identified from the Scientific Registry of Transplant Recipients between 2003 and 2012. The following measures were derived annually for each DSA: market competition using the Herfindahl Hirschman Index, transplantation center density by the Average Nearest Neighbor method, liver quality by the Liver Donor Risk Index, and patient risk by the Model for End-Stage Liver Disease. A hierarchical mixed effects negative binomial regression model of the relationship between liver transplants and market factors was created annually. Patient and graft survival were investigated with a Cox proportional hazards model. Transplantation center density was associated with market competition (p market competition (IRR = 1.36; p = 0.02), increased listings (IRR = 1.14; p market variables were associated with increased mortality after transplantation. After controlling for demographic and market factors, a greater concentration of centers was associated with more liver transplants without impacting overall survival. These results warrant additional investigation into the relationship between geospatial factors and liver transplantation volume with consideration for the optimization of scarce resources. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Relationship Between Mammographic Density and Breast Cancer Death in the Breast Cancer Surveillance Consortium

    Science.gov (United States)

    2012-01-01

    Background Women with elevated mammographic density have an increased risk of developing breast cancer. However, among women diagnosed with breast cancer, it is unclear whether higher density portends reduced survival, independent of other factors. Methods We evaluated relationships between mammographic density and risk of death from breast cancer and all causes within the US Breast Cancer Surveillance Consortium. We studied 9232 women diagnosed with primary invasive breast carcinoma during 1996–2005, with a mean follow-up of 6.6 years. Mammographic density was assessed using the Breast Imaging Reporting and Data System (BI-RADS) density classification. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression; women with scattered fibroglandular densities (BI-RADS 2) were the referent group. All statistical tests were two-sided. Results A total of 1795 women died, of whom 889 died of breast cancer. In multivariable analyses (adjusted for site, age at and year of diagnosis, American Joint Committee on Cancer stage, body mass index, mode of detection, treatment, and income), high density (BI-RADS 4) was not related to risk of death from breast cancer (HR = 0.92, 95% CI = 0.71 to 1.19) or death from all causes (HR = 0.83, 95% CI = 0.68 to 1.02). Analyses stratified by stage and other prognostic factors yielded similar results, except for an increased risk of breast cancer death among women with low density (BI-RADS 1) who were either obese (HR = 2.02, 95% CI = 1.37 to 2.97) or had tumors of at least 2.0cm (HR = 1.55, 95% CI = 1.14 to 2.09). Conclusions High mammographic breast density was not associated with risk of death from breast cancer or death from any cause after accounting for other patient and tumor characteristics. Thus, risk factors for the development of breast cancer may not necessarily be the same as factors influencing the risk of death after breast cancer has developed. PMID:22911616

  2. Surface renewal: an advanced micrometeorological method for measuring and processing field-scale energy flux density data.

    Science.gov (United States)

    McElrone, Andrew J; Shapland, Thomas M; Calderon, Arturo; Fitzmaurice, Li; Paw U, Kyaw Tha; Snyder, Richard L

    2013-12-12

    Advanced micrometeorological methods have become increasingly important in soil, crop, and environmental sciences. For many scientists without formal training in atmospheric science, these techniques are relatively inaccessible. Surface renewal and other flux measurement methods require an understanding of boundary layer meteorology and extensive training in instrumentation and multiple data management programs. To improve accessibility of these techniques, we describe the underlying theory of surface renewal measurements, demonstrate how to set up a field station for surface renewal with eddy covariance calibration, and utilize our open-source turnkey data logger program to perform flux data acquisition and processing. The new turnkey program returns to the user a simple data table with the corrected fluxes and quality control parameters, and eliminates the need for researchers to shuttle between multiple processing programs to obtain the final flux data. An example of data generated from these measurements demonstrates how crop water use is measured with this technique. The output information is useful to growers for making irrigation decisions in a variety of agricultural ecosystems. These stations are currently deployed in numerous field experiments by researchers in our group and the California Department of Water Resources in the following crops: rice, wine and raisin grape vineyards, alfalfa, almond, walnut, peach, lemon, avocado, and corn.

  3. Relationship of implant stability and bone density derived from computerized tomography images.

    Science.gov (United States)

    Merheb, Joe; Vercruyssen, Marjolein; Coucke, Wim; Quirynen, Marc

    2018-02-01

    Implant stability is one of the most important factors influencing osseointegration. Using stereolithographical guides for maximizing precision, this study aimed at investigating the relationship between implant stability and bone density derived from computerized tomography analysis. One hundred ninety-five implants were placed in 48 patients using digitally designed stereolithographical surgical guides. Ninety-five implants were placed using a mucosa supported guide and 100 implants were placed using a bone supported guide. Implant stability was measured by means of resonance frequency analysis (RFA) and damping capacity assessment (Periotest, PTV). Bone density (Hounsfield units) was measured at different regions of interest (ROI) and cortex thickness was measured around each implant. Implant stability correlated significantly with the different ROI. The best correlation for RFA was obtained for the spongious bone ROI (r = .64) and PTV best correlated with the coronal cortex density (r = -.41). Shorter implants (9 mm) had a significantly lower primary stability than longer implants (11, 13, 15 mm). Primary stability was also significantly higher in 4 mm diameter implants than in 3.5 mm diameter implants. A formula for the prediction of primary stability based on the different variables investigated was developed. Bone density and cortex thickness have a significant influence on implant primary stability. Longer and wider implants reached higher primary stability than shorter and narrower implants. These correlations lose their significance after osseointegration has taken place. Implant stability can be predicted based on an preoperative analysis of bone characteristics. © 2017 Wiley Periodicals, Inc.

  4. Solvent effects in ionic liquids: empirical linear energy-density relationships.

    Science.gov (United States)

    Cerda-Monje, A; Aizman, A; Tapia, R A; Chiappe, C; Contreras, R

    2012-07-28

    Multiparameter linear energy-density relationships to model solvent effects in room temperature ionic liquids (RTILs) are introduced and tested. The model incorporates two solvent dependent and two specific solute-solvent parameters represented by a set of electronic indexes derived from the conceptual density functional theory. The specific solute-solvent interactions are described in terms of the electronic chemical potential for proton migration between the anion or cation and the transition state structure of a specific reaction. These indexes provide a quantitative estimation of the hydrogen bond (HB) acceptor basicity and the hydrogen bond donor acidity of the ionic solvent, respectively. A sound quantitative scale of HB strength is thereby obtained. The solvent dependent contributions are described by the global electrophilicity of the cation and nucleophilicity of the anion forming the ionic liquid. The model is illustrated for the kinetics of cycloaddition of cyclopentadiene towards acrolein. In general, cation HB acidity outweighs the remaining parameters for this reaction.

  5. Further studies on the relationship between platelet buoyant density and platelet age

    International Nuclear Information System (INIS)

    Boneu, B.; Vigoni, F.; Boneu, A.; Caranobe, C.; Sie, P.

    1982-01-01

    The relationship between platelet buoyant density and platelet age was investigated in eight human subjects submitted to an autologous chromium labeled platelet survival study. Platelets were isolated after isopycnic centrifugation using eight discontinuous isoosmotic stractan gradients (five subjects), or various continuous and linear isoosmolar gradients (three subjects). A paradoxical radioactivity enrichment of the dense platelets and a premature loss of radioactivity in the light platelets were observed. These results are explained by a shift of the radioactivity distribution curve toward higher densities during the 3-4 days after platelet injection, while the standard deviation of the distribution was conserved throughout the platelet life span. These results suggest that young platelets are heterogeneous and slightly less dense than the total platelet population

  6. The relationship between adipokines, body composition, and bone density in men with chronic obstructive pulmonary disease.

    Science.gov (United States)

    Vondracek, Sheryl F; Voelkel, Norbert F; McDermott, Michael T; Valdez, Connie

    2009-01-01

    Osteoporosis is common in patients with chronic obstructive pulmonary disease (COPD). Data regarding the relationship between adipokines and bone mineral density (BMD) in this population is lacking. The purpose of this pilot study was to determine associations between the adipokines tumor necrosis factor-alpha (TNF-alpha), leptin, adiponectin and resistin, body composition, and BMD in men with severe COPD. This was a cross-sectional study of men with severe COPD who visited the University of Colorado Hospital COPD Center. Bone density and parameters of body composition were measured by dual-energy X-ray absorptiometry. Twenty-three men were included (mean age = 66 years, mean percent predicted forced expiratory volume in one second = 32%). On bivariate analysis, there was no association between TNF-alpha and BMD. Parameters of body composition and serum concentrations of leptin and adiponectin were significantly associated with total hip and spine bone density. However, with partial correlation analysis, total body mass was the only independent predictor of total hip BMD, explaining approximately 50% of the variability. Overall, 18 out of 23 men enrolled (78%) had low bone density by T-score, and nine (39%) were classified as having osteoporosis. The men with osteoporosis had lower parameters of body composition, lower mean serum leptin concentrations, and a greater impairment in measures of lung function compared to the men without osteoporosis. We conclude that the effect of adipokines on BMD does not appear to be independent of body mass. However, larger studies are needed to further evaluate the relationship between adipokines, body weight, and BMD in patients with COPD.

  7. RELATIONSHIP BETWEEN TRAINING VOLUME AND BONE MINERAL DENSITY CHANGES IN ELDERLY WOMEN

    Directory of Open Access Journals (Sweden)

    Juan José Rábade Espinosa

    Full Text Available ABSTRACT Introduction: Several studies have analyzed the relationship between physical activity and bone density. However, the prescription of exercise is not entirely clear as to the type, quantity and intensity. Objective: The objective of this study was to determine if there is a relationship between the amount of exercise and changes in bone mineral density. Methods: Fifty-two women, members of the Municipal Program of Physical Activity for Seniors, voluntarily underwent two ultrasonographies of the calcaneus within a 6-month interval. During this period, all physical activity was recorded. Afterwards, a lineal correlation study was carried out between the amount of exercise and bone changes, expressed as T-Score variation, first in total number of participants and then in groups. Considering the average body weight obtained for all women, two groups were created ("light" 69 kg. Later, women who had participated in less than 72% of the targeted program were excluded from both groups, and the differences between the groups "light and trained" and "heavy and trained" were analyzed. To do so, the nonparametric Mann-Whitney U test was used. Results: A significant relationship of r= -0.59 was found between the total amount of exercise and the T-Score variation in the group of women above 69 kg. Significant differences were found between the "light and trained" group and the "heavy and trained" group with respect to the variation of T-Score. Conclusion: The effect of exercise on bone mineral density is determined, somehow, by body weight. This interaction is due, possibly, to mechanical demands difference.

  8. FLUXNET: A new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities

    DEFF Research Database (Denmark)

    Baldocchi, D.; Falge, E.; Gu, L.

    2001-01-01

    , it provides infrastructure for compiling, archiving, and distributing carbon, water, and energy flux measurement, and meteorological, plant, and soil data to the science community. (Data and site information are available online at the FLUXNET Web site, http://www-eosdis.oml.gov/FLUXNTET/.) Second....... The overarching goal is to provide information for validating computations of net primary productivity, evaporation, and energy absorption that are being generated by sensors mounted on the NASA Terra satellite. Data being compiled by FLUXNET are being used to quantify and compare magnitudes and dynamics...... of annual ecosystem carbon and water balances, to quantify the response of stand-scale carbon dioxide and water vapor flux densities to controlling biotic and abiotic factors, and to validate a hierarchy of soil-plant-atmosphere trace gas exchange models. Findings so far include 1) net CO2 exchange...

  9. Limb alignment, subluxation, and bone density relationship in the osteoarthritic varus knee.

    Science.gov (United States)

    Khamaisy, Saker; Nam, Denis; Thein, Ran; Rivkin, Gurion; Liebergall, Meir; Pearle, Andrew

    2015-06-01

    Lower limb alignment, tibiofemoral (TF) subluxation, and bone density changes around the knee are significant factors related to the development of knee osteoarthritis (OA) and have great impact on its severity. The relation of each factor to knee OA was evaluated separately in previous studies; however, few studies have attempted to integrate their respective effects. The purpose of this study was to determine if an identifiable interaction exists between coronal limb alignment, TF subluxation, and bone density in the development of knee OA. A total of 120 patients with symptomatic, varus knee OA, with preoperative standing anteroposterior (AP) hip-to-ankle radiographs and a computed tomographic scan of the knee, were included in this study. Overall mechanical lower extremity alignment, and TF subluxation were measured on the AP radiographs, while trabecular bone density (TBD) was measured in four regions of interest for both the tibial plateau and distal femur in all patients. The patients were stratified into the following four cohorts: (A) high subluxation, high angulation; (B) high subluxation, low angulation; (C) low subluxation, high angulation; and (D) low subluxation, low angulation. The mean TBD in group B was significantly higher than in groups C and D (p = 0.003 and 0.03, respectively). In addition, the mean TBD in group A was significantly higher than in group C. This study highlights the relationship between limb alignment, knee subluxation, and bone density in the osteoarthritic knee. These preliminary results present a proof-of-principle, that bone mineral density affects the degree of coronal alignment and TF subluxation in OA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  10. A DEFINITION FOR GIANT PLANETS BASED ON THE MASS–DENSITY RELATIONSHIP

    International Nuclear Information System (INIS)

    Hatzes, Artie P.; Rauer, Heike

    2015-01-01

    We present the mass–density relationship (log M − log ρ) for objects with masses ranging from planets (M ≈ 0.01 M Jup ) to stars (M > 0.08 M ⊙ ). This relationship shows three distinct regions separated by a change in slope in the log M − log ρ plane. In particular, objects with masses in the range 0.3 M Jup –60 M Jup follow a tight linear relationship with no distinguishing feature to separate the low-mass end (giant planets) from the high-mass end (brown dwarfs). We propose a new definition of giant planets simply based on changes in the slope of the log M versus log ρ relationship. By this criterion, objects with masses less than ≈0.3 M Jup are low-mass planets, either icy or rocky. Giant planets cover the mass range 0.3 M Jup –60 M Jup . Analogous to the stellar main sequence, objects on the upper end of the giant planet sequence (brown dwarfs) can simply be referred to as “high-mass giant planets,” while planets with masses near that of Jupiter can be called “low-mass giant planets.”

  11. Effect of texture and grain size on the magnetic flux density and core loss of cold-rolled high silicon steel sheets

    International Nuclear Information System (INIS)

    Qin, Jing; Yang, Ping; Mao, Weimin; Ye, Feng

    2015-01-01

    The effects of texture and grain size on the magnetic flux density and core loss (50–20 kHz) of 0.23 mm-thick cold-rolled high silicon steel sheets are investigated by means of electron back-scattered diffraction (EBSD), loss separation, and anisotropy parameter (ε) calculation. A model of the hysteresis loss coefficient k h considering average grain size and ε is established. The magnetic flux density at 800 A/m (B 8 ) is closely related to the volume fraction of η-fiber-oriented grains, while the magnetic flux density at 5000 A/m (B 50 ) is closely related to the volume fractions of γ- and λ-fiber-oriented grains in high silicon steel. The hysteresis loss of high silicon steel can be greatly reduced by increasing the grain size and optimizing the texture of the sheets. Although increases in frequencies decrease the effect of texture on core loss, the effect cannot be ignored. As annealing temperature and time increase, the relative difference in core loss between the rolling direction (RD) and the transverse direction (TD) is maintained at higher frequencies because of increases in grain size, decreases in γ texture, and maintenance of a strong η texture. Texture and grain size jointly affect the high-frequency core loss of high silicon steel. - Highlights: • A model of hysteresis loss coefficient considering anisotropy parameter is obtained. • Effect of texture on high-frequency core loss of high-silicon steel cannot be ignored. • Texture and grain size jointly affect high-frequency core loss of high-silicon steel

  12. Effect of texture and grain size on the magnetic flux density and core loss of cold-rolled high silicon steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Jing [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Yang, Ping, E-mail: yangp@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Mao, Weimin [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Ye, Feng [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-11-01

    The effects of texture and grain size on the magnetic flux density and core loss (50–20 kHz) of 0.23 mm-thick cold-rolled high silicon steel sheets are investigated by means of electron back-scattered diffraction (EBSD), loss separation, and anisotropy parameter (ε) calculation. A model of the hysteresis loss coefficient k{sub h} considering average grain size and ε is established. The magnetic flux density at 800 A/m (B{sub 8}) is closely related to the volume fraction of η-fiber-oriented grains, while the magnetic flux density at 5000 A/m (B{sub 50}) is closely related to the volume fractions of γ- and λ-fiber-oriented grains in high silicon steel. The hysteresis loss of high silicon steel can be greatly reduced by increasing the grain size and optimizing the texture of the sheets. Although increases in frequencies decrease the effect of texture on core loss, the effect cannot be ignored. As annealing temperature and time increase, the relative difference in core loss between the rolling direction (RD) and the transverse direction (TD) is maintained at higher frequencies because of increases in grain size, decreases in γ texture, and maintenance of a strong η texture. Texture and grain size jointly affect the high-frequency core loss of high silicon steel. - Highlights: • A model of hysteresis loss coefficient considering anisotropy parameter is obtained. • Effect of texture on high-frequency core loss of high-silicon steel cannot be ignored. • Texture and grain size jointly affect high-frequency core loss of high-silicon steel.

  13. Relationship between N2O Fluxes from an Almond Soil and Denitrifying Bacterial Populations Estimated by Quantitative PCR

    Science.gov (United States)

    Matiasek, M.; Suddick, E. C.; Smart, D. R.; Scow, K. M.

    2008-12-01

    Cultivated soils emit substantial quantities of nitrous oxide (N2O), a greenhouse gas with almost 300 times the radiative forcing potential of CO2. Agriculture-related activities generate from 6 to 35 Tg N2O-N per year, or about 60 to 70% of global production. The microbial processes of nitrification, denitrification and nitrifier denitrification are major biogenic sources of N2O to the atmosphere from soils. Denitrification is considered the major source of N2O especially when soils are wet. The microbial N transformations that produce N2O depend primarily on nitrogen (N) fertilizer, with water content, available carbon and soil temperature being secondary controllers. Despite the fact that microbial processes are responsible for N2O emissions, very little is known about the numbers or types of populations involved. The objective of this study was to relate changes in denitrifying population densities, using quantitative PCR (qPCR) of functional genes, to N2O emissions in a fertilized almond orchard. Quantitative PCR targeted three specific genes involved in denitrification: nirS, nirK and nosZ. Copy numbers of the genes were related back to population densities and the portion of organisms likely to produce nitrous oxide. The study site, a 21.7 acre almond orchard fitted with micro-sprinklers, was fertigated (irrigated and fertilized simultaneously) with 50 lbs/acre sodium nitrate in late March 2008, then irrigated weekly. Immediately after the initial fertigation, fluxes of N2O and CO2, moisture content, inorganic N and denitrification gene copy numbers were measured 6 times over 24 days. Despite the fact that N2O emissions increased following fertigation, there was no consistent increase in any of the targeted genes. The genes nirK and nirS ranged from 0.4-1.4 × 107 and 0.4-1.4 × 108, whereas nosZ ranged from 2-8 × 106 copy numbers per g soil, respectively. Considerable variation, compounded by the small sample sizes used for DNA analysis, made it difficult

  14. Carbon - Bulk Density Relationships for Highly Weathered Soils of the Americas

    Science.gov (United States)

    Nave, L. E.

    2014-12-01

    Soils are dynamic natural bodies composed of mineral and organic materials. As a result of this mixed composition, essential properties of soils such as their apparent density, organic and mineral contents are typically correlated. Negative relationships between bulk density (Db) and organic matter concentration provide well-known examples across a broad range of soils, and such quantitative relationships among soil properties are useful for a variety of applications. First, gap-filling or data interpolation often are necessary to develop large soil carbon (C) datasets; furthermore, limitations of access to analytical instruments may preclude C determinations for every soil sample. In such cases, equations to derive soil C concentrations from basic measures of soil mass, volume, and density offer significant potential for purposes of soil C stock estimation. To facilitate estimation of soil C stocks on highly weathered soils of the Americas, I used observations from the International Soil Carbon Network (ISCN) database to develop carbon - bulk density prediction equations for Oxisols and Ultisols. Within a small sample set of georeferenced Oxisols (n=89), 29% of the variation in A horizon C concentrations can be predicted from Db. Including the A-horizon sand content improves predictive capacity to 35%. B horizon C concentrations (n=285) were best predicted by Db and clay content, but were more variable than A-horizons (only 10% of variation explained by linear regression). Among Ultisols, a larger sample set allowed investigation of specific horizons of interest. For example, C concentrations of plowed A (Ap) horizons are predictable based on Db, sand and silt contents (n=804, r2=0.38); gleyed argillic (Btg) horizon concentrations are predictable from Db, sand and clay contents (n=190, r2=0.23). Because soil C stock estimates are more sensitive to variation in soil mass and volume determinations than to variation in C concentration, prediction equations such as

  15. The relationship between adipokines, body composition, and bone density in men with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Sheryl F Vondracek

    2009-07-01

    Full Text Available Sheryl F Vondracek1, Norbert F Voelkel2, Michael T McDermott3, Connie Valdez11Department of Clinical Pharmacy; 3Department of Medicine, University of Colorado Denver, Aurora, CO, USA; 2Department of Internal Medicine and Victoria Johnson Center for Emphysema Research, Virginia Commonwealth University, Richmond, VA, USAAbstract: Osteoporosis is common in patients with chronic obstructive pulmonary disease (COPD. Data regarding the relationship between adipokines and bone mineral density (BMD in this population is lacking. The purpose of this pilot study was to determine associations between the adipokines tumor necrosis factor-alpha (TNF-α, leptin, adiponectin and resistin, body composition, and BMD in men with severe COPD. This was a cross-sectional study of men with severe COPD who visited the University of Colorado Hospital COPD Center. Bone density and parameters of body composition were measured by dual-energy X-ray absorptiometry. Twenty-three men were included (mean age = 66 years, mean percent predicted forced expiratory volume in one second = 32%. On bivariate analysis, there was no association between TNF-α and BMD. Parameters of body composition and serum concentrations of leptin and adiponectin were significantly associated with total hip and spine bone density. However, with partial correlation analysis, total body mass was the only independent predictor of total hip BMD, explaining approximately 50% of the variability. Overall, 18 out of 23 men enrolled (78% had low bone density by T-score, and nine (39% were classified as having osteoporosis. The men with osteoporosis had lower parameters of body composition, lower mean serum leptin concentrations, and a greater impairment in measures of lung function compared to the men without osteoporosis. We conclude that the effect of adipokines on BMD does not appear to be independent of body mass. However, larger studies are needed to further evaluate the relationship between adipokines

  16. Relationships between carbon fluxes and environmental factors in a drip-irrigated, film-mulched cotton field in arid region

    Science.gov (United States)

    Li, Xiaoyu; Liu, Lijuan; Yang, Huijin; Li, Yan

    2018-01-01

    Environmental factors and human activities play important roles in carbon fixation and emissions generated from croplands. Eddy covariance measurements in a drip-irrigated, film-mulched cotton field were used to analyze the relationships between carbon fluxes and environmental factors in Wulanwusu, northern Xinjiang, an arid region of Northwest China. Our results showed that the cumulative net carbon flux (NEE) was -304.8 g C m-2 (a strong sink) over the whole cotton growing season in 2012, which was more than that in cotton cropland without plastic film mulching and drip-irrigation. Moreover, when time is scaled up from a half-hour to a month, the correlations of gross primary production (GPP) to air temperature (Tair), net solar radiation (Rn) and soil water content (SWC) gradually become stronger due to ecosystem resistance and resilience as well as the protection of plastic film mulching. The GPP is more strongly correlated with Rn than Tair at time scales from minutes to days, while it reverses at time scales from days to weeks. This outcome is largely determined by the biochemical characteristics of photosynthesis. SWC and vapor pressure deficit (VPD) at all time scales are weakly correlated with GPP because plastic film mulching and regularly drip-irrigation allow soil to maintain sufficient water. PMID:29415018

  17. Relationships between carbon fluxes and environmental factors in a drip-irrigated, film-mulched cotton field in arid region.

    Directory of Open Access Journals (Sweden)

    Xiaoyu Li

    Full Text Available Environmental factors and human activities play important roles in carbon fixation and emissions generated from croplands. Eddy covariance measurements in a drip-irrigated, film-mulched cotton field were used to analyze the relationships between carbon fluxes and environmental factors in Wulanwusu, northern Xinjiang, an arid region of Northwest China. Our results showed that the cumulative net carbon flux (NEE was -304.8 g C m-2 (a strong sink over the whole cotton growing season in 2012, which was more than that in cotton cropland without plastic film mulching and drip-irrigation. Moreover, when time is scaled up from a half-hour to a month, the correlations of gross primary production (GPP to air temperature (Tair, net solar radiation (Rn and soil water content (SWC gradually become stronger due to ecosystem resistance and resilience as well as the protection of plastic film mulching. The GPP is more strongly correlated with Rn than Tair at time scales from minutes to days, while it reverses at time scales from days to weeks. This outcome is largely determined by the biochemical characteristics of photosynthesis. SWC and vapor pressure deficit (VPD at all time scales are weakly correlated with GPP because plastic film mulching and regularly drip-irrigation allow soil to maintain sufficient water.

  18. Relationships between carbon fluxes and environmental factors in a drip-irrigated, film-mulched cotton field in arid region.

    Science.gov (United States)

    Li, Xiaoyu; Liu, Lijuan; Yang, Huijin; Li, Yan

    2018-01-01

    Environmental factors and human activities play important roles in carbon fixation and emissions generated from croplands. Eddy covariance measurements in a drip-irrigated, film-mulched cotton field were used to analyze the relationships between carbon fluxes and environmental factors in Wulanwusu, northern Xinjiang, an arid region of Northwest China. Our results showed that the cumulative net carbon flux (NEE) was -304.8 g C m-2 (a strong sink) over the whole cotton growing season in 2012, which was more than that in cotton cropland without plastic film mulching and drip-irrigation. Moreover, when time is scaled up from a half-hour to a month, the correlations of gross primary production (GPP) to air temperature (Tair), net solar radiation (Rn) and soil water content (SWC) gradually become stronger due to ecosystem resistance and resilience as well as the protection of plastic film mulching. The GPP is more strongly correlated with Rn than Tair at time scales from minutes to days, while it reverses at time scales from days to weeks. This outcome is largely determined by the biochemical characteristics of photosynthesis. SWC and vapor pressure deficit (VPD) at all time scales are weakly correlated with GPP because plastic film mulching and regularly drip-irrigation allow soil to maintain sufficient water.

  19. The Entropy Solutions for the Lighthill-Whitham-Richards Traffic Flow Model with a Discontinuous Flow-Density Relationship

    National Research Council Canada - National Science Library

    Lu, Yadong; Wong, S. C; Zhang, Mengping; Shu, Chi-Wang

    2007-01-01

    ...) traffic flow model with a flow-density relationship which is piecewise quadratic, concave, but not continuous at the junction points where two quadratic polynomials meet, and with piecewise linear...

  20. The relationship between Computed Tomography and DXA results: A potential bias in Bone Mineral Density assessment

    Directory of Open Access Journals (Sweden)

    Andrey Bokov

    2017-06-01

    Full Text Available Background It has been reported that the results of the lumbar spine bone mineral density assessment can be strongly biased by degenerative changes. However, the reported data remains controversial and a potential bias has not been assessed. Aims To evaluate the relationships between the results of DXA and CT with the assessment of potential bias related to the influence of different structures. Methods This is a cross-sectional study and 25 patients were enrolled. Using DXA scan, Bone Mineral density (BMD (g/cm2 was calculated from 100 vertebra from the lumbar spine. Out of all the CT measurements, a mean radiodensity in HU (Hounsfield Units for cancellous bone and total vertebra body, a mean square and radiodensity of vertebra pedicles and facet were calculated. Results Linear regression analysis demonstrated a strong correlation between BMD measured by DXA and CT data. Multiple correlation coefficient of model accounts for 0.8093, r2=0.6550, p<0.0001. Parameters that have significant relationships with the results of DXA were: a product of facet joints radiodensity and mean square on axial images (B= 0.000003379, p<0.0001 and total vertebral body radiodensity B=0.0016395253, p=0.0201. Beta coefficients for those variables accounted for 0.6729 and 0.3037 respectively. Conclusion The results of the bone mineral density assessment of the lumbar spine using DXA, can be strongly influenced by facet joints condition, especially in cases of degenerative changes. The results of BMD, provided by DXA, are partly relevant to vertebral body bone quality assessment and irrelevant to the characteristics of bone in pedicles. This means that the prognostic value of the DXA measurement results might be limited in relation to predicting low energy vertebra fracture and implant stability.

  1. Bone turnover in elderly men: relationships to change in bone mineral density

    Directory of Open Access Journals (Sweden)

    Center Jacqueline R

    2007-02-01

    Full Text Available Abstract Background It is not clear whether bone turnover markers can be used to make inference regarding changes in bone mineral density (BMD in untreated healthy elderly men. The present study was designed to address three specific questions: (i is there a relationship between bone turnover markers and femoral neck BMD within an individual; (ii is there a relationship between baseline measurements of bone turnover markers and subsequent change in BMD; and (iii is there a relationship between changes in bone turnover markers and changes in femoral neck BMD? Methods The present study was part of the on-going Dubbo Osteoporosis Epidemiology Study, which was designed as a prospective investigation. Men who had had at least 3 sequential visits with serum samples available during follow-up were selected from the study population. Serum C-terminal telopeptide of type I collagen (sICTP, N-terminal propeptide of type I collagen (sPINP and femoral neck BMD were measured by competitive radioimmunoassays. Femoral neck bone mineral density (BMD was measured by a densitometer (GE Lunar Corp, Madison, WI. Various mixed-effects models were used to assess the association between the markers and changes in BMD. Results One hundred and one men aged 70 ± 4.1 years (mean ± SD met the criteria of selection for analysis. On average, sPINP decreased by 0.7% per year (p = 0.026, sICTP increased by 1.7% per year (p = 0.0002, and femoral neck BMD decreased by 0.4% per year (p Conclusion These results suggest that in elderly men of Caucasian background, changes in sPINP were inversely related to changes in BMD within an individual. However, neither sPINP nor sICTP was sufficiently sensitive to predict the rate of change in BMD for a group of individuals or for an individual.

  2. Poloidal density variation of impurities in a rotating tokamak plasma - flux surface coordinates and effect on transport coefficients

    International Nuclear Information System (INIS)

    Romanelli, M.

    1999-09-01

    The poloidal variation of impurity densities over magnetic surfaces brings about an enhancement of neoclassical transport coefficients, as shown by Romanelli and Ottaviani for impurities in the Pfirsch Schlueter regime and by Helander for particles in the banana-plateau regime, both in a large aspect ratio tokamak. The same effect will occur in a finite aspect ratio tokamak and therefore it is considered to be relevant for inclusion in transport codes for comparison with the experimental measurements of impurity transport. Here an expression for the impurity-density poloidal-variation generated by the fast toroidal rotation of the plasma column is presented in general coordinates. (author)

  3. Modification of Human-Biometeorologically Significant Radiant Flux Densities by Shading as Local Method to Mitigate Heat Stress in Summer within Urban Street Canyons

    Directory of Open Access Journals (Sweden)

    Hyunjung Lee

    2013-01-01

    Full Text Available Increasing heat will be a significant problem for Central European cities in the future. Shading devices are discussed as a method to mitigate heat stress on citizens. To analyze the physical processes, which are characteristic of shading in terms of urban human-biometeorology, experimental investigations on the thermal effects of shading by a building and shading by tree canopies were conducted in Freiburg (Southwest Germany during typical Central European summer weather. Urban human-biometeorology stands for the variables air temperature Ta, mean radiant temperature Tmrt, and physiologically equivalent temperature PET, that is the human-biometeorological concept to assess the thermal environment which was applied. The measuring setup consists of specific human-biometeorological stations, which enable the direct or indirect determination of Ta, Tmrt, and PET. With respect to both shading devices, the Ta reduction did not exceed 2°C, while PET as a measure for human heat stress was lowered by two thermal sensation steps according to the ASHRAE scale. As Tmrt has the role of a key variable for outdoor thermal comfort during Central European summer weather, all radiant flux densities relevant to the determination of Tmrt were directly measured and analyzed in detail. The results show the crucial significance of the horizontal radiant flux densities for Tmrt and consequently PET.

  4. The influence of the number of activation detectors on the Seibersdorf - Milano intercomparison of neutron flux density spectra by WINDOWS code

    International Nuclear Information System (INIS)

    Ertek, C.

    1981-02-01

    This work is a continuation of the work performed within the IAEA programme on standardization of reactor radiation measurements, one of the important objectives of which is the assistance to laboratories in Member States to implement or intercompare the multiple foil activation techniques for different neutron field measurements. The importance of these techniques is well recognized. In CESNEF-FERMI Politecnico di Milano, Italy, they have installed near the core of a water boiler of 50kW, a neutron filter made of B 4 C in order to obtain a neutron flux density spectrum that could be of utility in intercalibration problems connected with irradiation in fast assemblies. Dr. V. Sangiust from CESNEF kindly sent the input guess neutron flux density spectrum and a series of measured reaction rates to be treated by the IAEA Seibersdorf laboratory using the SAND-II and the WINDOWS unfolding codes. The meaningful comparison using partly the same ENDF/B IV cross section data is performed. In the present work we extended the investiga tion using WINDOWS unfolding code for different numbers of activation fo ils or reaction rates

  5. Tracer kinetic studies of the low density lipoprotein metabolism in the fetal rat: An example for estimation of flux rates in the nonsteady state

    International Nuclear Information System (INIS)

    Plonne, D.; Schlag, B.; Winkler, L.; Dargel, R.

    1990-01-01

    To get insight into the low density lipoprotein (LDL)-apoB flux in the rat fetus near term and in the early postnatal period, homologous apoE-free 125I-labeled LDL was injected into the umbilical vein of the rat fetus immediately after Caesarean section. Since the serum LDL-apoB spontaneously declined after birth, a time-dependent two-pool model was used to calculate the flux rates in the neonate from the specific activities of LDL-apoB up to 15 h post partum. An approximate value of LDL-apoB flux in the fetus at birth was obtained by extrapolation of the kinetic data to the time of injection of the tracer. The data revealed that the turnover of LDL-apoB in the fetus (18.6 micrograms LDL-apoB/h per g body weight) exceeded that in the adult rat (0.4 microgram/h per g body weight) by at least one order of magnitude. Even 15 h after delivery, the LDL-apoB influx amounted to 2.5 micrograms/h per g body weight. The fractional catabolic rate of LDL-apoB in the fetus at term (0.39, h-1) slightly exceeded that in the adult animal (0.15, h-1) and reached the adult level within the first 3 h after birth and remained constant thereafter. In the rat fetus, LDL-apoB flux greatly exceeds that of VLDL-apoB. The data support the view of a direct synthesis and secretion of LDL, most probably by the fetal membranes

  6. The relationship between the local temperature and the local heat flux within a one-dimensional semi-infinite domain of heat wave propagation

    Directory of Open Access Journals (Sweden)

    Kulish Vladimir V.

    2003-01-01

    Full Text Available The relationship between the local temperature and the local heat flux has been established for the homogeneous hyperbolic heat equation. This relationship has been written in the form of a convolution integral involving the modified Bessel functions. The scale analysis of the hyperbolic energy equation has been performed and the dimensionless criterion for the mode of energy transport, similar to the Reynolds criterion for the flow regimes, has been proposed. Finally, the integral equation, relating the local temperature and the local heat flux, has been solved numerically for those processes of surface heating whose time scale is of the order of picoseconds.

  7. The relationship between educational level and bone mineral density in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Nas Kemal

    2004-09-01

    Full Text Available Abstract Background This study describes the influence of educational level on bone mineral density (BMD and investigating the relationship between educational level and bone mineral density in postmenopausal women. Methods A total of 569 postmenopausal women, from 45 to 86 years of age (mean age of 60.43 ± 7.19 years were included in this study. A standardized interview was used at the follow-up visit to obtain information on demographic, life-style, reproductive and menstrual histories such as age at menarche, age at menopause, number of pregnancies, number of abortions, duration of menopause, duration of fertility, and duration of lactation. Patients were separated into four groups according to the level of education, namely no education (Group 1 with 209 patients, elementary (Group 2 with 222 patients, high school (Group 3 with 79 patients, and university (Group 4 with 59 patients. Results The mean ages of groups were 59.75 ± 7.29, 61.42 ± 7.50, 60.23 ± 7.49, and 58.72 ± 7.46, respectively. Spine BMD was significant lower in Group 1 than that of other groups (p Conclusions The results of the study suggest that there is a significant correlation between educational level and BMD. Losses in BMD for women of lower educational level tend to be relatively high, and losses in spine and femur BMD showed a decrease with increasing educational level.

  8. The Relationship between the Triglyceride to High-Density Lipoprotein Cholesterol Ratio and Metabolic Syndrome.

    Science.gov (United States)

    Shin, Hyun-Gyu; Kim, Young-Kwang; Kim, Yong-Hwan; Jung, Yo-Han; Kang, Hee-Cheol

    2017-11-01

    Metabolic syndrome is associated with cardiovascular diseases and is characterized by insulin resistance. Recent studies suggest that the triglyceride/high-density lipoprotein cholesterol (TG/HDLC) ratio predicts insulin resistance better than individual lipid levels, including TG, total cholesterol, low-density lipoprotein cholesterol (LDLC), or HDLC. We aimed to elucidate the relationship between the TG/HDLC ratio and metabolic syndrome in the general Korean population. We evaluated the data of adults ≥20 years old who were enrolled in the Korean National Health and Nutrition Examination Survey in 2013 and 2014. Subjects with angina pectoris, myocardial infarction, stroke, or cancer were excluded. Metabolic syndrome was defined by the harmonized definition. We examined the odds ratios (ORs) of metabolic syndrome according to TG/HDLC ratio quartiles using logistic regression analysis (SAS ver. 9.4; SAS Institute Inc., Cary, NC, USA). Weighted complex sample analysis was also conducted. We found a significant association between the TG/HDLC ratio and metabolic syndrome. The cutoff value of the TG/HDLC ratio for the fourth quartile was ≥3.52. After adjustment, the OR for metabolic syndrome in the fourth quartile compared with that of the first quartile was 29.65 in men and 20.60 in women (Pmetabolic syndrome.

  9. A grouping method based on grid density and relationship for crowd evacuation simulation

    Science.gov (United States)

    Li, Yan; Liu, Hong; Liu, Guang-peng; Li, Liang; Moore, Philip; Hu, Bin

    2017-05-01

    Psychological factors affect the movement of people in the competitive or panic mode of evacuation, in which the density of pedestrians is relatively large and the distance among them is small. In this paper, a crowd is divided into groups according to their social relations to simulate the actual movement of crowd evacuation more realistically and increase the attractiveness of the group based on social force model. The force of group attraction is the synthesis of two forces; one is the attraction of the individuals generated by their social relations to gather, and the other is that of the group leader to the individuals within the group to ensure that the individuals follow the leader. The synthetic force determines the trajectory of individuals. The evacuation process is demonstrated using the improved social force model. In the improved social force model, the individuals with close social relations gradually present a closer and coordinated action while following the leader. In this paper, a grouping algorithm is proposed based on grid density and relationship via computer simulation to illustrate the features of the improved social force model. The definition of the parameters involved in the algorithm is given, and the effect of relational value on the grouping is tested. Reasonable numbers of grids and weights are selected. The effectiveness of the algorithm is shown through simulation experiments. A simulation platform is also established using the proposed grouping algorithm and the improved social force model for crowd evacuation simulation.

  10. Volume temperature relationship for iron at 330 GPa and the Earth's core density deficit

    Science.gov (United States)

    Shanker, J.; Singh, B. P.; Srivastava, S. K.

    2004-12-01

    Estimates of core density deficit (cdd) of the Earth's outer core recently reported by Anderson and Isaak [Another look at the core density deficit of Earth's outer core, Phys. Earth Planet Int. 131 (2002) 19-27] are questionable in view of the serious errors in the pressure-volume and bulk modulus data due to an inadequacy in the calibration process used by Mao et al. [Static compression of iron to 300 GPa and Fe0.8Ni0.2 alloy to 200 GPa: implications for the core, J. Geophys. Res. 94 (1990) 21737-21742]. The data used by Anderson and Isaak deviate significantly from the corresponding values derived from seismology. In the present study we have used the input data on density, isothermal bulk modulus and its pressure derivative from Stacey and Davis [High pressure equations of state with application to lower mantle and core, Phys. Earth Planet Int. 142 (2004) 137-184] which are consistent with the seismological data. Volumes of hexagonal close-packed iron have been calculated at different temperatures under isobaric conditions at P = 330 GPa, the inner core boundary (ICB) pressure using the relationship between thermal pressure and volume expansion based on the lattice potential theory originally due to Born and Huang [Dynamical Theory of Crystal Lattices, Oxford University Press, Oxford, 1954, p. 50]. The formulation for thermal pressure used by Anderson and Isaak has been modified by taking into account the variations of thermal expansivity α and isothermal bulk modulus KT with temperature. Values of cdd are then estimated corresponding to different temperatures ranging from 4000 to 8000 K. The results for cdd at different temperatures obtained in the present study are significantly higher than those estimated by Anderson and Isaak suggesting that the cdd for the Earth's outer core is nearly 10%. The effects of nickel when an Fe-Ni alloy replaces Fe are estimated and found to be insignificant.

  11. Regional vascular density-visual field sensitivity relationship in glaucoma according to disease severity.

    Science.gov (United States)

    Shin, Joong Won; Lee, Jiyun; Kwon, Junki; Choi, Jaewan; Kook, Michael S

    2017-12-01

    To study whether there are global and regional relationships between peripapillary vascular density (pVD) assessed by optical coherence tomography angiography (OCT-A) and visual field (VF) mean sensitivity at different glaucoma stages. Microvascular images and peripapillary retinal nerve fibre layer (pRNFL) thicknesses were obtained using a Cirrus OCT-A device in 91 glaucoma subjects. The pVD was measured at various spatial locations according to the Garway-Heath map, using a MATLAB software (The MathWorks, Natick, Massachusetts). VF mean sensitivity (VFMS) was recorded in the 1/L scale. Global and regional vasculature-function (pVD vs VFMS) relationships were assessed in separate patient groups at mild and moderate-to-advanced stages of glaucoma. The pVDs at superotemporal and inferotemporal regions were significantly associated with corresponding VFMS in mild glaucoma (pglaucoma, there were significant associations between pVD and VFMS, regardless of location. The association between global pVD and VFMS was significantly stronger than that between global pRNFL thickness and VFMS in moderate-to-advanced stage glaucoma (p glaucoma. OCT-A may be useful in monitoring glaucoma at various stages. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Being in a romantic relationship is associated with reduced gray matter density in striatum and increased subjective happiness

    Directory of Open Access Journals (Sweden)

    Hiroaki Kawamichi

    2016-11-01

    Full Text Available Romantic relationship, a widespread feature of human society, is one of the most influential factors in daily life. Although stimuli related to romantic love or being in a romantic relationship commonly result in enhancement of activation or functional connectivity of the reward system, including the striatum, the structure underlying romantic relationship-related regions remain unclear. Because individual experiences can alter gray matter within the adult human brain, we hypothesized that romantic relationship is associated with structural differences in the striatum related to the positive subjective experience of being in a romantic relationship. Because intimate romantic relationships contribute to perceived subjective happiness, this subjective enhancement of happiness might be accompanied by the experience of positive events related to being in a romantic relationship. To test this hypothesis and elucidate the structure involved, we compared subjective happiness, an indirect measure of the existence of positive experiences caused by being in a romantic relationship, of participants with or without romantic partners (N = 68. Furthermore, we also conducted a voxel-based morphometry (VBM study of the effects of being in a romantic relationship (N = 113. Being in a romantic relationship was associated with greater subjective happiness and reduced gray matter density within the right dorsal striatum. These results suggest that being in a romantic relationship enhances perceived subjective happiness via positive experiences. Furthermore, the observed reduction in gray matter density in the right dorsal striatum may reflect an increase in saliency of social reward within a romantic relationship. Thus, being in a romantic relationship is associated with positive experiences and a reduction of gray matter density in the right dorsal striatum, representing a modulation of social reward.

  13. Being in a Romantic Relationship Is Associated with Reduced Gray Matter Density in Striatum and Increased Subjective Happiness

    Science.gov (United States)

    Kawamichi, Hiroaki; Sugawara, Sho K.; Hamano, Yuki H.; Makita, Kai; Matsunaga, Masahiro; Tanabe, Hiroki C.; Ogino, Yuichi; Saito, Shigeru; Sadato, Norihiro

    2016-01-01

    Romantic relationship, a widespread feature of human society, is one of the most influential factors in daily life. Although stimuli related to romantic love or being in a romantic relationship commonly result in enhancement of activation or functional connectivity of the reward system, including the striatum, the structure underlying romantic relationship-related regions remain unclear. Because individual experiences can alter gray matter within the adult human brain, we hypothesized that romantic relationship is associated with structural differences in the striatum related to the positive subjective experience of being in a romantic relationship. Because intimate romantic relationships contribute to perceived subjective happiness, this subjective enhancement of happiness might be accompanied by the experience of positive events related to being in a romantic relationship. To test this hypothesis and elucidate the structure involved, we compared subjective happiness, an indirect measure of the existence of positive experiences caused by being in a romantic relationship, of participants with or without romantic partners (N = 68). Furthermore, we also conducted a voxel-based morphometry study of the effects of being in a romantic relationship (N = 113). Being in a romantic relationship was associated with greater subjective happiness and reduced gray matter density within the right dorsal striatum. These results suggest that being in a romantic relationship enhances perceived subjective happiness via positive experiences. Furthermore, the observed reduction in gray matter density in the right dorsal striatum may reflect an increase in saliency of social reward within a romantic relationship. Thus, being in a romantic relationship is associated with positive experiences and a reduction of gray matter density in the right dorsal striatum, representing a modulation of social reward. PMID:27895606

  14. Conductivity of ion dielectrics during the mean flux-density electron- and X-ray pulse radiation

    International Nuclear Information System (INIS)

    Vajsburd, D.I.; Mesyats, G.A.; Naminov, V.L.; Tavanov, Eh.G.

    1982-01-01

    Conductivity of ion dielectrics under electron and X-ray pulse radiation is investigated. Investigations have been conducted in the range of average beam densities in which extinction of low-energy conductivity takes place. Thin plates of alkali-halogen crystals have been used as samples. Small-dimensional accelerator with controlled beam parameters: 1-20 ns, 0.1-2000 A/cm 2 , 0.3-0.5 MeV has been used for radiation. Temperature dependence of conductivity current pulse is determined. Time resolution of 10 - 10 s is achieved. In the 70-300 K range it practically coincides with radiation pulse. An essential inertial constituent is observed below 300 K. It is shown that at average beam densities a comparable contribution into fast conductivity is made by intracentre conductivity independent of temperature and high-temperature conductivity which decreases with temperature with activation energy equal to the energy of short-wave background. That is why amplitude of fast constituent decreases with temperature slower than high-energy conductivity

  15. Comparison between nano-diamond and carbon nanotube doping effects on critical current density and flux pinning in MgB2

    International Nuclear Information System (INIS)

    Cheng, C H; Yang, Y; Munroe, P; Zhao, Y

    2007-01-01

    Doping effects of nano-diamond and carbon nanotubes (CNTs) on critical current density of bulk MgB 2 have been studied. CNTs are found prone to be doped into the MgB 2 lattice whereas nano-diamond tends to form second-phase inclusions in the MgB 2 matrix, leading to a more significant improvement of J c (H) by doping by nano-diamond than by CNTs in MgB 2 . TEM reveals tightly packed MgB 2 nanograins (50-100 nm) with a dense distribution of diamond nanoparticles (10-20 nm) inside MgB 2 grains in nano-diamond-doped samples. Such a unique microstructure leads to a flux pinning behaviour different from that in CNTs-doped MgB 2

  16. Relationship between local molecular field theory and density functional theory for non-uniform liquids.

    Science.gov (United States)

    Archer, A J; Evans, R

    2013-01-07

    The local molecular field theory (LMF) developed by Weeks and co-workers has proved successful for treating the structure and thermodynamics of a variety of non-uniform liquids. By reformulating LMF in terms of one-body direct correlation functions we recast the theory in the framework of classical density functional theory (DFT). We show that the general LMF equation for the effective reference potential φ(R)(r) follows directly from the standard mean-field DFT treatment of attractive interatomic forces. Using an accurate (fundamental measures) DFT for the non-uniform hard-sphere reference fluid we determine φ(R)(r) for a hard-core Yukawa liquid adsorbed at a planar hard wall. In the approach to bulk liquid-gas coexistence we find the effective potentials exhibit rich structure that can include damped oscillations at large distances from the wall as well as the repulsive hump near the wall required to generate the low density "gas" layer characteristic of complete drying. We argue that it would be difficult to obtain the same level of detail from other (non-DFT based) implementations of LMF. LMF emphasizes the importance of making an intelligent division of the interatomic pair potential of the full system into a reference part and a remainder that can be treated in mean-field approximation. We investigate different divisions for an exactly solvable one-dimensional model where the pair potential has a hard-core plus a linear attractive tail. Results for the structure factor and the equation of state of the uniform fluid show that including a significant portion of the attraction in the reference system can be much more accurate than treating the full attractive tail in mean-field approximation. We discuss further aspects of the relationship between LMF and DFT.

  17. Prevalence of the STK15 F31I polymorphism and its relationship with mammographic density

    Directory of Open Access Journals (Sweden)

    J. Giacomazzi

    2011-04-01

    Full Text Available Several studies have identified the single nucleotide polymorphism STK15 F31I as a low-penetrance risk allele for breast cancer, but its prevalence and risk association in the Brazilian population have not been determined. The goal of this study was to identify the frequency of this polymorphism in the Brazilian setting. Considering the high degree of admixture of our population, it is of fundamental importance to validate the results already reported in the literature and also to verify the relationship between this variant and breast cancer risk. A total of 750 women without breast cancer were genotyped using the TaqMan PCR assay for STK15 F31I polymorphism. Clinical information was obtained from review of the medical records and mammographic density from the images obtained using the BI-RADS System. The estimated risk of developing cancer was calculated according to the Gail model. The genotypic frequencies observed in this study were 4.5, 38.7, and 56.6%, respectively, for the STK15 F31I AA, AT and TT genotypes. The AT and AA genotypes were encountered significantly more often in premenopausal women with moderately dense, dense and heterogeneously dense breast tissue (P = 0.023. In addition, the presence of the TT genotype was significantly associated with age at menarche ≥12 years (P = 0.023. High mammographic density, associated with increased breast cancer risk, was encountered more frequently in premenopausal women with the risk genotypes STK15 F31I AA and AT. The genotypic frequencies observed in our Brazilian sample were similar to those described in other predominantly European populations.

  18. Study on the relationship between serum testosterone level and forearm distal bone density in post-menopausal women

    International Nuclear Information System (INIS)

    Li Wenqi; Zhou Zhengli; Li Xin; Zhou Jiwen

    2002-01-01

    Objective: To study the relationship between the androgen level and bone density in post-menopausal women. Methods: Serum testosterone (T) level and forearm distal bone density (BMD) were measured in 39 past-menopausal women who had never taken any estrogen or calcium preparation. Their serum estradiol (E 2 ) levels were about the same. According to their BMD, the 39 subjects were divided into normal (n = 22) and osteoporotic (n = 17) groups. Results: The mean serum testosterone (T) level in the normal group was significantly higher than that in the osteoporotic group (p 1 = 0.72, r 2 0.75; p 1 and r 2 was 0.14, suggesting similarity of the positive cor-relationship for both groups (p > 0.05). Conclusion: Serum testosterone level seems to bear close relationship with bone density and osteoporosis

  19. ON THE RELATIONSHIP BETWEEN A HOT-CHANNEL-LIKE SOLAR MAGNETIC FLUX ROPE AND ITS EMBEDDED PROMINENCE

    International Nuclear Information System (INIS)

    Cheng, X.; Ding, M. D.; Zhang, J.; Guo, Y.; Chen, P. F.; Sun, J. Q.; Srivastava, A. K.

    2014-01-01

    A magnetic flux rope (MFR) is a coherent and helical magnetic field structure that has recently been found likely to appear as an elongated hot channel prior to a solar eruption. In this Letter, we investigate the relationship between the hot channel and the associated prominence through analysis of a limb event on 2011 September 12. In the early rise phase, the hot channel was initially cospatial with the prominence. It then quickly expanded, resulting in a separation of the top of the hot channel from that of the prominence. Meanwhile, they both experienced an instantaneous morphology transformation from a Λ shape to a reversed-Y shape and the top of these two structures showed an exponential increase in height. These features are a good indication of the occurrence of kink instability. Moreover, the onset of kink instability is found to coincide in time with the impulsive enhancement of flare emission underneath the hot channel, suggesting that ideal kink instability likely also plays an important role in triggering fast flare reconnection besides initiating the impulsive acceleration of the hot channel and distorting its morphology. We conclude that the hot channel is most likely the MFR system and the prominence only corresponds to the cool materials that are collected in the bottom of the helical field lines of the MFR against gravity

  20. Relationship Between Bone Turnover and Bone Density in Perimenopausal and Early Postmenopausal Women - Original Investigation

    Directory of Open Access Journals (Sweden)

    Nurdan Paker

    2009-04-01

    Full Text Available Aim: The aim of this study was to investigate the relationship between the bone turnover and bone density in perimenopausal and postmenopausal women. Material and Methods: Forty-two healthy women, 16 perimenopausal and 26 early postmenopausal were included in the study. Bone density at the spine and proximal femur was measured by dual energy x-ray absorptiometry (DXA. Routine serum biochemical tests were performed. Serum alkaline phosphatase (ALP level was measured. Bone turnover markers including serum osteocalcin (OC and and type I collagen crosslinked C-terminal telopeptide (CTX levels were measured. Results: Mean age was 48±4 years, body mass index (BMI was 27.87±4.26 kg/m2. Mean age at menopause was 45±9 years, time after menopause was 3.23±1.9 years in early postmenopausal group. Serum OC and CTX levels were 19.23±7.52 mg/dl and 0.58±0.35 mg/dl, respectively. CTX level was high in 21.6% (9 women of the study subjects, whereas OC level was high in 36.3% (15 women of the group. Osteoporosis and osteopenia rates in the study subjects were 11.9% and 40.4%, respectively. BMD values at the spine and proximal femur did not show correlation with bone turnover markers. Serum ALP level showed statistically significant negative correlation with femoral neck BMD (p=0.003. BMI showed statistically significant correlation with BMD values at femoral neck and total femur (p=0.033, p=0.001. There were no statistically significant difference in terms of serum OC and CTX levels and BMD values at spine and hip between the perimenopausal and early postmenopausal groups (p>0.05. Conclusion: As our results there was no correlation between bone turnover markers and bone density at spine and hip in perimenauposal and early postmenauposal women. (From the World of Osteoporosis 2009;15:7-10

  1. Investigation of the Polytropic Relationship Between Density and Temperature Within Interplanetary Coronal Mass Ejections Using Numerical Simulations

    Science.gov (United States)

    Riley, Pete; Gosling, J. T.; Pizzo, V. J.

    2001-01-01

    Single-point spacecraft measurements within coronal mass ejections (CMEs) often exhibit a negative correlation between electron density and temperature. At least two opposing interpretations have been suggested for this relationship. If, on one hand, these single spacecraft observations provide direct measures of the polytropic properties of the plasma, then they imply that the polytropic index for the electrons gamma(sub e) is often density and temperature, suggesting that gamma(sub e) > 1. In this study we simulate the evolution of a variety of CME-like disturbances in the solar wind using a one-dimensional, single-fluid model, to address the interpretation of the relationship between electron density and temperature within CMEs at fixed locations in space. Although we strictly impose a polytropic relationship (with gamma = constant) throughout our simulations, we demonstrate that a variety of correlations can exist between density and temperature at fixed points. Furthermore, we demonstrate that the presence of only local uncorrelated random fluctuations in density and temperature can produce a negative correlation. Consequently, we conclude that these single-point observations of negative correlations between electron density and temperature cannot be used to infer the value of gamma(sub e). Instead, we suggest that entropy variations, together with the plasma's tendency to achieve pressure balance with its surroundings, are responsible for the observed profiles.

  2. Defining the Magnitude: Patterns, Regularities and Direct TOA-Surface Flux Relationships in the 15-Year Long CERES Satellite Data — Observations, Model and Theory

    Science.gov (United States)

    Zagoni, M.

    2017-12-01

    Over the past fifteen years, the NASA Clouds and the Earth's Radiant Energy System (CERES) satellite mission has provided the scientific community with the most reliable Earth radiation budget data. This presentation offers quantitative assessment of the published CERES Energy Balanced and Filled (EBAF) Edition 2.8 and Edition 4.0 data products, and reveals several internal patterns, ratios and regularities within the annual global mean flux components of the all-sky and clear-sky surface and atmospheric energy budgets. The found patterns, among others, include: (i) direct relationships between the top-of-atmosphere (TOA) radiative and surface radiative and non-radiative fluxes (contradicting the expectation that TOA and surface fluxes are physically decoupled); (ii) integer ratios and relationships between the absorbed and emitted surface and atmospheric energy flow elements; and (iii) definite connections among the clear-sky and the all-sky shortwave, longwave and non-radiative (turbulent) flux elements and the corresponding greenhouse effect. Comparison between the EBAF Ed2.8 and Ed4.0 SFC and TOA data products and trend analyses of the normalized clear-sky and all-sky greenhouse factors are presented. Longwave cloud radiative effect (LW CRE) proved to be playing a principal role in organizing the found numerical patterns in the surface and atmospheric energy flow components. All of the revealed structures are quantitatively valid within the one-sigma range of uncertainty of the involved individual flux elements. This presentation offers a conceptual framework to interpret the found relationships and shows how the observed CERES fluxes can be deduced from this proposed physical model. An important conclusion drawn from our analysis is that the internal atmospheric and surface energy flow system forms a definite structure and seems to be more constrained to the incoming solar energy than previously thought.

  3. [Relationship among anthropometric and gluco-metabolic parameters, bone mineral density and endometriosis].

    Science.gov (United States)

    Nava-González, Edna J; de la Garza-Casas, Yolanda E; Salazar-Montalvo, Raúl G; Gallegos-Cabriales, Esther C

    2013-01-01

    women with endometriosis may have a decreased bone mineral density (BMD). Several studies have shown that accumulation of adipose tissue profoundly affects BMD. It has also been documented that excess body fat is associated with risk of developing endometriosis. The aim was to analyze the relationship between BMD, fat mass, and the insulin-glucose axis in women with endometriosis. thirty women with a diagnosis of endometriosis established by surgery were enrolled to participate in an observational prospective study. Anthropometry was performed to determine body mass index, and a dual X-ray densitometry to collect data on body composition and BMD. Glucose and insulin determinations were performed. Women were divided in two groups: with normal weight (n = 18) or overweight (n = 12). For the analysis of the results, we used descriptive statistics and Pearson's test. normal weight/overweight: mean age 32.5/35.2 years; body mass index 21.5/30.2; adiposity index: 27.7 %/36.1 %; fat mass index: 35.4/45.8 %; overweight women showed a significant value with p < 0.05. overweight, high values of adiposity index and fat mass index were related to endometriosis. This could support the hypothesis about a common pathogenesis among endometriosis, osteoporosis, diabetes and obesity.

  4. Relationship between Helicobacter pylori infection (HP) and bone mineral density (BMD) in elderly people.

    Science.gov (United States)

    Fotouk-Kiai, Mahdiye; Hoseini, Seyed Reza; Meftah, Neda; Ghadimi, Reza; Bijani, Ali; Noreddini, Hajighorban; Nematollahi, Hamidreza; Shokri-Shirvani, Javad

    2015-01-01

    Low bone mass is a frequent complication of chronic inflammatory disease. The pathogenesis of osteoporosis in chronic inflammatory disease may be secondary to releases of cytokines such as TNF- and IL6. Chronic gastritis due to helicobacter pylori (HP) infection may lead to decreased bone mineral density (BMD) and predispose patients to osteoporosis. The objective of this study was to determine the BMD status in HP positive patients with gastritis versus HP negative cases. In this cross-sectional study, we enrolled 967 participants aged 60 years old and more from Amirkola Health Study Ageing Project. Seven-hundred and fifty eight HP positive and 209 HP negative patients were analyzed. BMD was measured by dual-energy x-ray absorptiometry (DXA) method in the spine and femoral neck in all participants. The mean age in HP+ and HP- negative patients was 68.3±6.8 and 69.3±7.4 years, respectively. BMD g/cm2 in the spine and femoral neck did not differ between the two groups (P=0.19 and 0.22 respectively). The prevalence of osteoporosis did not also differ across the two groups as well. There was no relationship between the level of antibodies against HP and BMD. According to the findings of this study, H. pylori infection is not associated with BMD changes in the elderly population.

  5. Relationship of internal macrobioeroder densities in living massive Porites to turbidity and chlorophyll on the Australian Great Barrier Reef

    Science.gov (United States)

    Le Grand, H. M.; Fabricius, K. E.

    2011-03-01

    This study investigates the relationship between the density of internal macrobioeroders in living massive Porites and nutrient status. The study was conducted along turbidity and chlorophyll gradients towards river mouths on 12 reefs in four regions of the inshore Great Barrier Reef. Mean internal macrobioeroder densities doubled from 2 to 8 m depth, and at the 8 m sites, densities increased 4- to 7-fold towards the river mouths in all regions. Densities also increased 1.6-fold for each additional 1 NTU turbidity and 650-fold per 1 μg L-1 additional chlorophyll a. The study shows that the density of macrobioeroder boreholes in living massive Porites is a simple bioindicator measure for changing turbidity and chlorophyll concentrations on the Great Barrier Reef for sites from which direct water quality measurements are unavailable.

  6. Bone turnover in passive smoking female rat: relationships to change in bone mineral density

    Directory of Open Access Journals (Sweden)

    Xu Wen-shuo

    2011-06-01

    Full Text Available Abstract Background Many studies have identified smoking as a risk factor for osteoporosis, but it is unclear whether passive smoking has an effect on bone mineral density and bone turnover and if such an effect could cause osteoporosis.The purpose of the study was to investigate the effect of passive smoking on bone mineral density (BMD and bone turnover and the relationship between BMD and bone turnover in female rat. Methods Forty-eight female Wistar rats were randomized into six groups: 2-month, 3-month,4-month smoke-exposed rats and their controls. A rat model of passive cigarette smoking was prepared by breeding female rats in a cigarette-smoking box for 2, 3 or 4 months. Serums were analyzed for levels of osteocalcin, bone-specific alkaline phosphatase (b-ALP and Tartrate-resistant acid phosphatase 5b (TRACP 5b. BMD was assessed at lumbar vertebrae and femur by dual energy X-ray absorptiometry in passive smoking rats and in control rats. Results BMD of lumbar spine and femur was lower in 4-month smoke-exposed female rats than that in controls. However, there was no significant difference in serum osteocalcin levels between smoke-exposed rats and controls. Significantly lower b-ALP and higher TRACP 5b were found in the 3-month or 4-month smoke-exposed rats compared to controls. Subsequent analysis showed that b-ALP positively correlated with BMD of the lumbar vertebrae(r = 0.764, P = 0.027 and femur(r = 0.899, P = 0.002 in 4-month smoke-exposed female rats. Furthermore, TRACP 5b levels negatively correlated with BMD of lumbar vertebrae (r = -0.871, P = 0.005 and femur (r = -0.715, P = 0.046 in 4-month smoke-exposed female rats. Conclusion Our data suggest that smoke exposure can inhibit bone formation and increase bone resorption. The hazardous effects of passive smoking on bone status are associated with increased bone turnover in female rat.

  7. Bone turnover in passive smoking female rat: relationships to change in bone mineral density.

    Science.gov (United States)

    Gao, Shu-guang; Li, Kang-hua; Xu, Mai; Jiang, Wei; Shen, Hong; Luo, Wei; Xu, Wen-shuo; Tian, Jian; Lei, Guang-hua

    2011-06-11

    Many studies have identified smoking as a risk factor for osteoporosis, but it is unclear whether passive smoking has an effect on bone mineral density and bone turnover and if such an effect could cause osteoporosis.The purpose of the study was to investigate the effect of passive smoking on bone mineral density (BMD) and bone turnover and the relationship between BMD and bone turnover in female rat. Forty-eight female Wistar rats were randomized into six groups: 2-month, 3-month,4-month smoke-exposed rats and their controls. A rat model of passive cigarette smoking was prepared by breeding female rats in a cigarette-smoking box for 2, 3 or 4 months. Serums were analyzed for levels of osteocalcin, bone-specific alkaline phosphatase (b-ALP) and Tartrate-resistant acid phosphatase 5b (TRACP 5b). BMD was assessed at lumbar vertebrae and femur by dual energy X-ray absorptiometry in passive smoking rats and in control rats. BMD of lumbar spine and femur was lower in 4-month smoke-exposed female rats than that in controls. However, there was no significant difference in serum osteocalcin levels between smoke-exposed rats and controls. Significantly lower b-ALP and higher TRACP 5b were found in the 3-month or 4-month smoke-exposed rats compared to controls. Subsequent analysis showed that b-ALP positively correlated with BMD of the lumbar vertebrae(r = 0.764, P = 0.027) and femur(r = 0.899, P = 0.002) in 4-month smoke-exposed female rats. Furthermore, TRACP 5b levels negatively correlated with BMD of lumbar vertebrae (r = -0.871, P = 0.005) and femur (r = -0.715, P = 0.046) in 4-month smoke-exposed female rats. Our data suggest that smoke exposure can inhibit bone formation and increase bone resorption. The hazardous effects of passive smoking on bone status are associated with increased bone turnover in female rat.

  8. The relationship of maternal bone density with nutritional rickets in Nigerian children.

    Science.gov (United States)

    Hsu, Jennifer; Fischer, Philip R; Pettifor, John M; Thacher, Tom D

    2017-04-01

    Factors that affect maternal bone mineral density may be related to the risk of nutritional rickets in their offspring. Our aim was to determine the relationship between maternal areal bone mineral density (aBMD) and rickets in Nigerian children. Using a case-control design, we measured forearm aBMD in 56 and 135 mothers of children with and without nutritional rickets, respectively. Active rickets was confirmed or excluded in all children radiographically. Using logistic regression, we assessed the association of maternal aBMD, adjusted for parity, pregnancy and lactation status, duration of most recent completed lactation, age of menarche, height, body mass index, and maternal age with nutritional rickets. The median (range) age of all mothers was 30years (17-47years), and parity was 4 (1-12). A total of 36 (19%) were pregnant and 55 (29%) were currently breast feeding. Mean (±SD) metaphyseal forearm aBMDs were 0.321±0.057 and 0.316±0.053g/cm 2 in mothers of children with and without rickets, respectively (P=0.60). Diaphyseal forearm aBMDs were 0.719±0.071 and 0.715±0.072g/cm 2 , respectively (P=0.69). In an adjusted analysis, maternal forearm aBMD, bone mineral content and bone area at metaphyseal and diaphyseal sites were not associated with rickets in the child. In the adjusted analysis, rickets was associated with shorter duration of most recently completed lactation (aOR 0.91 for each additional month; 95% CI 0.83-0.99), older maternal age (aOR 1.07 for each additional year; 1.00-1.14), and less frequent maternal use of lead-containing eye cosmetics (aOR 0.20; 95% CI 0.05-0.64), without any difference in maternal blood lead levels. Maternal age, parity, age of menarche, height, and body mass index were not associated with having had a child with rickets in multivariate analysis. Nutritional rickets in Nigerian children was not associated with maternal forearm aBMD. Other unidentified maternal characteristics and practices likely contribute to the risk

  9. Relationships among Alcohol Outlet Density, Alcohol Use, and Intimate Partner Violence Victimization among Young Women in the United States

    Science.gov (United States)

    Waller, Martha W.; Iritani, Bonita J.; Christ, Sharon L.; Clark, Heddy Kovach; Moracco, Kathryn E.; Halpern, Carolyn Tucker; Flewelling, Robert L.

    2012-01-01

    Greater access to alcohol has been widely found to be associated with many negative outcomes including violence perpetration. This study examines the relationship between alcohol outlet density, alcohol use, and intimate partner violence (IPV) victimization among young women in the United States. A direct association between alcohol outlet density…

  10. The relationships between blood pressure, blood glucose, and bone mineral density in postmenopausal Turkish women.

    Science.gov (United States)

    Cakmak, Huseyin Altug; Cakmak, Burcu Dincgez; Yumru, Ayse Ender; Aslan, Serkan; Enhos, Asim; Kalkan, Ali Kemal; Coskun, Ebru Inci; Acikgoz, Abdullah Serdar; Karatas, Suat

    2015-01-01

    Hypertension, diabetes mellitus, and osteoporosis are important comorbidities commonly seen in postmenopausal women. The aim of the present study was to investigate the relationships between blood pressure, blood glucose, and bone mineral density (BMD) in postmenopausal Turkish women. In this cross-sectional study, 270 consecutive patients who were admitted to an outpatient clinic with vasomotor symptoms and/or at least 1 year of amenorrhea were included. The patients were categorized into three groups according to their blood pressure and metabolic status as follows: normotensive, hypertensive nondiabetics, and hypertensive diabetics. The T- and z-scores of the proximal femur and lumbar vertebrae were measured with the dual-energy X-ray absorptiometry method to assess the BMD of the study groups. Lumbar vertebral T-scores (P<0.001), lumbar vertebral z-scores (P<0.003), and proximal femoral T-scores (P<0.001) were demonstrated to be significantly lower in the hypertensive diabetic group compared to the hypertensive nondiabetic and normotensive groups. Systolic blood pressure was significantly inversely correlated with lumbar vertebral T-scores (r=-0.382; P=0.001), lumbar vertebral z-scores (r=-0.290; P=0.001), and proximal femoral T-scores (r=-0.340; P=0.001). Moreover, diastolic blood pressure was significantly inversely correlated with lumbar vertebral T-scores (r=-0.318; P=0.001), lumbar vertebral z-scores (r=-0.340; P=0.001), and proximal femoral T-scores (r=-0.304; P=0.001). Hypertension (odds ratio [OR]: 2.541, 95% confidence interval [CI]: 1.46-3.48, P=0.003), diabetes mellitus (OR: 2.136, 95% CI: 1.254-3.678, P=0.006), and age (OR: 1.069, 95% CI: 1.007-1.163, P=0.022) were found to be significant independent predictors of osteopenia in a multivariate analysis, after adjusting for other risk parameters. The present study is the first to evaluate the relationships between blood pressure, blood glucose, and BMD in postmenopausal Turkish women. Moreover, both

  11. The relationships between blood pressure, blood glucose, and bone mineral density in postmenopausal Turkish women

    Directory of Open Access Journals (Sweden)

    Cakmak HA

    2015-10-01

    Full Text Available Huseyin Altug Cakmak,1 Burcu Dincgez Cakmak,2 Ayse Ender Yumru,3 Serkan Aslan,4 Asim Enhos,1 Ali Kemal Kalkan,4 Ebru Inci Coskun,5 Abdullah Serdar Acikgoz,6 Suat Karatas3 1Department of Cardiology, Mustafakemalpasa Government Hospital, Bursa, 2Department of Obstetric and Gynecology, Rize Kackar Government Hospital, Rize, 3Department of Obstetric and Gynecology, Sisli Hamidiye Etfal Training and Research Hospital, 4Department of Cardiology, Mehmet Akif Ersoy Thoracic and Cardiovascular Surgery Training and Research Hospital, Istanbul, 5Department of Obstetric and Gynecology, Inonu University, Malatya, 6Department of Obstetric and Gynecology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey Background: Hypertension, diabetes mellitus, and osteoporosis are important comorbidities commonly seen in postmenopausal women. The aim of the present study was to investigate the relationships between blood pressure, blood glucose, and bone mineral density (BMD in postmenopausal Turkish women.Methods: In this cross-sectional study, 270 consecutive patients who were admitted to an outpatient clinic with vasomotor symptoms and/or at least 1 year of amenorrhea were included. The patients were categorized into three groups according to their blood pressure and metabolic status as follows: normotensive, hypertensive nondiabetics, and hypertensive diabetics. The T- and z-scores of the proximal femur and lumbar vertebrae were measured with the dual-energy X-ray absorptiometry method to assess the BMD of the study groups.Results: Lumbar vertebral T-scores (P<0.001, lumbar vertebral z-scores (P<0.003, and proximal femoral T-scores (P<0.001 were demonstrated to be significantly lower in the hypertensive diabetic group compared to the hypertensive nondiabetic and normotensive groups. Systolic blood pressure was significantly inversely correlated with lumbar vertebral T-scores (r=-0.382; P=0.001, lumbar vertebral z-scores (r=-0.290; P=0.001, and

  12. Effects of dynamic heterogeneity and density scaling of molecular dynamics on the relationship among thermodynamic coefficients at the glass transition

    International Nuclear Information System (INIS)

    Koperwas, K.; Grzybowski, A.; Grzybowska, K.; Wojnarowska, Z.; Paluch, M.

    2015-01-01

    In this paper, we define and experimentally verify thermodynamic characteristics of the liquid-glass transition, taking into account a kinetic origin of the process. Using the density scaling law and the four-point measure of the dynamic heterogeneity of molecular dynamics of glass forming liquids, we investigate contributions of enthalpy, temperature, and density fluctuations to spatially heterogeneous molecular dynamics at the liquid-glass transition, finding an equation for the pressure coefficient of the glass transition temperature, dTg/dp. This equation combined with our previous formula for dTg/dp, derived solely from the density scaling criterion, implies a relationship among thermodynamic coefficients at Tg. Since this relationship and both the equations for dTg/dp are very well validated using experimental data at Tg, they are promising alternatives to the classical Prigogine-Defay ratio and both the Ehrenfest equations in case of the liquid-glass transition

  13. The Relationship of Age, Body Mass Index, and Individual Habit to Bone Mineral Density in Adults

    International Nuclear Information System (INIS)

    Park, Soung Ock; Lee, In Ja; Shin, Gwi Soon

    2008-01-01

    We studied the change of bone mineral density (BMD) by age, body mass index (BMI), coffee, carbonated drink, alcohol, smoking, and exercise in adults who checked in health center. The number of study subjects was total 268 persons (women of 136 persons and men of 132 persons). The BMD was determined in lumbar spine and femoral neck by dual energy x-ray absorptiometry. And we got some results as below : 1. In women, mean body height was , mean body weight was 155.8±6.0 cm, and mean BMI was 56.8±7.9 kg. In men, mean body height was 169.1±6.0 cm, mean body weight was 69.0±9.5 kg, and mean BMI was 24.1±2.7 kg/m 2 . 2. BMD decreased as age increased, and the age was the most determinant factor for BMD (p<0.01). Women's BMD decreased rapidly in the groups aged ≥50s, while men's BMD decreased gradually with age. In addition, for both sex, lower BMD was measured in lumbar spine than in femoral neck. 3. BMD increased in high BMI, and BMD with BMI increased distinctly in the group aged 50s. But their relationship was not significant. 4. In view of the distribution by three BMD categories, women's BMD was mostly normal in the groups aged ≥40s but the rate of osteopenia and osteoporosis was similar in the group aged 50s, and the rate of osteoporosis was the highest in the groups aged 60s and 70s. Men's BMD was mostly normal through all groups except the group aged 70s. 5. Coffee and carbonated drink were not influenced in BMD. But alcohol-drinking group showed higher BMD than non-drinking group, and alcohol was statistically significant determinant for BMD (p<0.05). Smoking and exercise were not statistically significant determinant of BMD.

  14. Preliminary analysis of the relationship between serum lutein and zeaxanthin levels and macular pigment optical density

    Directory of Open Access Journals (Sweden)

    Fujimura S

    2016-10-01

    Full Text Available Shigeto Fujimura,1,2 Kohei Ueda,1 Yoko Nomura,1 Yasuo Yanagi3,4 1Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, 2Department of Ophthalmology, Kanazawa University School of Medicine, Ishikawa, Japan; 3Singapore Eye Research Institute, 4Medical Retina Department, Singapore National Eye Centre, Singapore Purpose: To assess the relationship between combined serum lutein and zeaxanthin (L+Z concentration and macular pigment optical density (MPOD, and to investigate the effect of L+Z+docosahexaenoic acid (DHA dietary supplementation on the spatial distribution of MPOD.Methods: Twenty healthy fellow eyes with unilateral wet age-related macular degeneration or chronic central serous chorioretinopathy were included. All participants received a dietary supplement for 6 months that contained 20 mg L, 1 mg Z, and 200 mg DHA. The best-corrected visual acuity and contrast sensitivity (CS were measured at baseline and at 1, 3, and 6 months. Serum L+Z concentrations were measured at baseline and at 3 months. MPOD was calculated at each time point using fundus autofluorescent images.Results: Serum L+Z concentration was correlated with MPOD at 1°–2° eccentricity at baseline (r=0.63, P=0.003 and 3 months (r=0.53, P=0.015. Serum L+Z concentration increased by a factor of 2.3±1.0 (P<0.0001. At 6 months, MPOD was significantly higher compared to the baseline level at 0°–0.25° (P=0.034 and 0.25°–0.5° (P=0.032 eccentricity. CS improved after 3 or 6 months of L+Z+DHA supplementation (P<0.05.Conclusion: Juxtafoveal MPOD was associated with serum L+Z concentration. Foveal MPOD was increased by L+Z+DHA dietary supplementation. Keywords: fundus autofluorescence, supplement, spatial distribution

  15. The relationship between serum 25-hydroxy vitamin D, parathormone and bone mineral density in Indian population.

    Science.gov (United States)

    Garg, M K; Tandon, N; Marwaha, R K; Menon, A S; Mahalle, N

    2014-01-01

    Vitamin D deficiency (VDD) is a global problem. Not all patients with VDD have clinical manifestations or secondary hyperparathyroidism. We studied the interaction between serum 25-hydroxy vitamin D (25OHD), parathormone (PTH) and bone mineral density (BMD) in Indian adolescents and adults. Population survey. A total of 1829 adolescents and 1346 adults aged 50 years and above were analysed in this study. Serum biochemistry, 25OHD, PTH and BMD were estimated. Subjects were grouped according to quartiles of serum PTH. VDD was defined as severe (25OHD ≤ 5 ng/ml), moderate (25OHD ≤ 10 ng/ml) and mild (25OHD ≤ 20 ng/ml) and secondary hyperparathyroidism (SHPT) when serum PTH levels >65 pg/ml. Only 30-40% of subjects with moderate and severe VDD, respectively, had SHPT. BMD decreased from Quartile 1 to Quartile 4 of PTH at all sites among adolescents and adults, with only a marginal decline in serum 25OHD levels between these quartiles. Further, within each PTH quartile, there was no difference in BMD according to categories of VDD. Analysing BMD in the different PTH quartiles, the PTH cut-offs beyond which BMD showed a significant decline, was 35 pg/ml in adolescents and 53 pg/ml in adults. Less than half of the subjects with VDD have SHPT. BMD levels start to decline at PTH values currently considered to be normal. These data suggest the need to redefine SHPT in different age groups keeping in mind the relationship between PTH and BMD. This may also influence the decision to supplement subjects with VDD. © 2013 John Wiley & Sons Ltd.

  16. The relationship between periodontal disease, tooth loss and decreased skeletal bone mineral density in ageing women.

    Science.gov (United States)

    Savić Pavičin, Ivana; Dumančić, Jelena; Jukić, Tomislav; Badel, Tomislav

    2017-12-01

    Osteoporosis and periodontitis are both chronic diseases characterised by bone loss. Potential association is of great clinical importance because of multifactorial aetiology and common risk factors. The aim of this study was to determine relationship between bone mineral density (BMD), tooth loss and periodontal status taking into account age, number of years since onset of menopause and educational level. With increasing age, number of years since onset of menopause and lower educational level, decreased BMD, deteriorating periodontal status and greater tooth loss are expected. Cross-sectional study included 112 women aged 45-80 years (mean 58.3 years). BMD was determined for lumbar spine region and proximal femur by DEXA technology. Dental status and periodontal status were evaluated clinically and on panoramic radiographs. For the analysis of tooth loss frequency, participants were divided into four age groups. Significant inverse correlation was found between number of lost teeth and BMD at hip region (r = -.227; P = .028) but not at the lumbar spine (r = -.05; P = .669). Several indicators of the periodontal condition were significantly correlated with BMD, but not with postmenopausal period length. Important result is that participants missing one or more incisors or canines had significantly lower mean value of BMD comparing to those who had all the incisors and canines remained. Although osteoporosis is not the main cause of periodontitis, it may be a factor that leads to enhanced periodontal pocket depth and greater risk of tooth loss in ageing women. © 2017 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

  17. Analysis of the Relationship between Density and Mechanical Strength of Lightened Gypsums: Proposal for a Coefficient of Lightening

    Directory of Open Access Journals (Sweden)

    Jaime Santa Cruz Astorqui

    2017-01-01

    Full Text Available This article develops a relationship between the reduction of density in lightened gypsum and the addition of expanded and/or extruded polystyrene waste from the construction sector and their mechanical behavior. The equations determined in this study allow us to know the flexural and compressive strengths of a lightened gypsum/plaster compound once its density is known. The results show that there is an exponential relationship between the density of the compound and its strength. The methodology followed included a compilation of the results obtained in previous research works on lightweight gypsums, analyzing the relationship between density and mechanical strength and comparing them with the equations developed in this research. The results obtained by previous researchers have a good adjustment with the proposed models, and only perlite compounds present greater deviations in the compressive strength analysis. Also, a dimensionless lightening coefficient is defined which can help to determine the best application for a lightweight gypsum compound, comparing it with an ideal lightweight gypsum.

  18. Relationship between mechanical properties and bone mineral density of human femoral bone retrieved from patients with osteoarthritis.

    Science.gov (United States)

    Haba, Yvonne; Lindner, Tobias; Fritsche, Andreas; Schiebenhöfer, Ann-Kristin; Souffrant, Robert; Kluess, Daniel; Skripitz, Ralf; Mittelmeier, Wolfram; Bader, Rainer

    2012-01-01

    The objective of this study was to analyse retrieved human femoral bone samples using three different test methods, to elucidate the relationship between bone mineral density and mechanical properties. Human femoral heads were retrieved from 22 donors undergoing primary total hip replacement due to hip osteoarthritis and stored for a maximum of 24 hours postoperatively at + 6 °C to 8 °C.Analysis revealed an average structural modulus of 232±130 N/mm(2) and ultimate compression strength of 6.1±3.3 N/mm(2) with high standard deviations. Bone mineral densities of 385±133 mg/cm(2) and 353±172 mg/cm(3) were measured using thedual energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT), respectively. Ashing resulted in a bone mineral density of 323±97 mg/cm(3). In particular, significant linear correlations were found between DXA and ashing with r = 0.89 (p < 0.01, n = 22) and between structural modulus and ashing with r = 0.76 (p < 0.01, n = 22).Thus, we demonstrated a significant relationship between mechanical properties and bone density. The correlations found can help to determine the mechanical load capacity of individual patients undergoing surgical treatments by means of noninvasive bone density measurements.

  19. Functional relationships between wood structure and vulnerability to xylem cavitation in races of Eucalyptus globulus differing in wood density.

    Science.gov (United States)

    Barotto, Antonio José; Monteoliva, Silvia; Gyenge, Javier; Martinez-Meier, Alejandro; Fernandez, María Elena

    2018-02-01

    Wood density can be considered as a measure of the internal wood structure, and it is usually used as a proxy measure of other mechanical and functional traits. Eucalyptus is one of the most important commercial forestry genera worldwide, but the relationship between wood density and vulnerability to cavitation in this genus has been little studied. The analysis is hampered by, among other things, its anatomical complexity, so it becomes necessary to address more complex techniques and analyses to elucidate the way in which the different anatomical elements are functionally integrated. In this study, vulnerability to cavitation in two races of Eucalyptus globulus Labill. with different wood density was evaluated through Path analysis, a multivariate method that allows evaluation of descriptive models of causal relationship between variables. A model relating anatomical variables with wood properties and functional parameters was proposed and tested. We found significant differences in wood basic density and vulnerability to cavitation between races. The main exogenous variables predicting vulnerability to cavitation were vessel hydraulic diameter and fibre wall fraction. Fibre wall fraction showed a direct impact on wood basic density and the slope of vulnerability curve, and an indirect and negative effect over the pressure imposing 50% of conductivity loss (P50) through them. Hydraulic diameter showed a direct negative effect on P50, but an indirect and positive influence over this variable through wood density on one hand, and through maximum hydraulic conductivity (ks max) and slope on the other. Our results highlight the complexity of the relationship between xylem efficiency and safety in species with solitary vessels such as Eucalyptus spp., with no evident compromise at the intraspecific level. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Relationship between the gene polymorphism of osteoprotegerin and bone mineral density in hemodialysis patients.

    Science.gov (United States)

    Yin, L-L; Jing, N; Zhao, Z-Y; Liu, X-H; Du, J; Qin, L-L; Song, J-G; Xu, Y

    2017-01-01

    To investigate the relationship between the gene polymorphism of osteoprotegerin (OPG) and bone mineral density (BMD) in hemodialysis patients. A total of 147 patients with end-stage renal disease (ESRD) who were admitted to the Weifang People's Hospital for maintenance hemodialysis between January 2014 and December 2015 were enrolled. Peripheral blood was collected from the subjects for assay of the polymorphism of A163G and G1181C loci of OPG. The measurements of the levels of RANK, RANKL, TNF-α, IL-6, PINP, CTX-I, CTX-II and TRACP5 in the isolated serum were taken. For the polymorphism of A163G locus on the OPG gene, the BMDs of left femoral neck and lumbar poster anterior L1-L4 of the AA genotype were significantly higher than those of the AG and GG genotypes. There was no significant difference in comparison of BMDs at the forearm (distal 1/3) between the AA genotype and AG and GG genotypes. No significant differences were found in the comparison of BMDs at all sites between AG and GG genotypes. The serum level of RANKL of the AA genotype was significantly higher than levels of AG and GG genotypes, but the levels of RANK, TNF-α, IL-6, PINP, CTX-I, CTX-II and TRACP5 were prominently lower than those levels of AG and GG genotypes. For the polymorphism of G1181C locus on the OPG gene, the BMDs of left femoral neck and lumbar poster anterior L1-L4 of the CC genotype were significantly higher than the BMDs of GG and GC genotypes, There was no significant difference in the comparison of BMDs at the forearm (distal 1/3) between the CC genotype and GG and GC genotypes. No significant differences were found in the comparison of BMDs at all sites between GG and GC genotypes. The serum level of RANKL of the CC genotype was significantly higher than the level of GG and GC genotypes. However, the levels of RANK, TNF-α, IL-6, PINP, CTX-I, CTX-II and TRACP5 were prominently lower than those levels of GG and GC genotypes. The polymorphisms of A163G and G1181C loci on the

  1. The Relationship of Age, Body Mass Index, and Individual Habit to Bone Mineral Density in Adults

    Energy Technology Data Exchange (ETDEWEB)

    Park, Soung Ock; Lee, In Ja; Shin, Gwi Soon [Dept. of Radiologic Techology, Dongnam Health College, Suwon (Korea, Republic of)

    2008-12-15

    We studied the change of bone mineral density (BMD) by age, body mass index (BMI), coffee, carbonated drink, alcohol, smoking, and exercise in adults who checked in health center. The number of study subjects was total 268 persons (women of 136 persons and men of 132 persons). The BMD was determined in lumbar spine and femoral neck by dual energy x-ray absorptiometry. And we got some results as below : 1. In women, mean body height was , mean body weight was 155.8{+-}6.0 cm, and mean BMI was 56.8{+-}7.9 kg. In men, mean body height was 169.1{+-}6.0 cm, mean body weight was 69.0{+-}9.5 kg, and mean BMI was 24.1{+-}2.7 kg/m{sup 2}. 2. BMD decreased as age increased, and the age was the most determinant factor for BMD (p<0.01). Women's BMD decreased rapidly in the groups aged {>=}50s, while men's BMD decreased gradually with age. In addition, for both sex, lower BMD was measured in lumbar spine than in femoral neck. 3. BMD increased in high BMI, and BMD with BMI increased distinctly in the group aged 50s. But their relationship was not significant. 4. In view of the distribution by three BMD categories, women's BMD was mostly normal in the groups aged {>=}40s but the rate of osteopenia and osteoporosis was similar in the group aged 50s, and the rate of osteoporosis was the highest in the groups aged 60s and 70s. Men's BMD was mostly normal through all groups except the group aged 70s. 5. Coffee and carbonated drink were not influenced in BMD. But alcohol-drinking group showed higher BMD than non-drinking group, and alcohol was statistically significant determinant for BMD (p<0.05). Smoking and exercise were not statistically significant determinant of BMD.

  2. Effects of magnetic flux density and substrate bias voltage on Ni films prepared on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Koda, Tatsunori [Graduate School of Science and Technology, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan); Toyota, Hiroshi, E-mail: h.toyota.za@it-hiroshima.ac.jp [Department of Electronics and Computer Engineering, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan)

    2014-03-15

    The authors fabricated Ni films on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma. The effects of magnetic flux density B{sub C} and substrate DC bias voltage V{sub S} on the Ni film structures were investigated. For V{sub S} = −40 V, the average surface grain size D{sub G} measured by atomic force microscopy for B{sub C} = 0, 3, and 5 mT was 88.2, 95.4, and 104.4 nm, respectively. In addition, D{sub G} increased with V{sub S}. From x-ray diffraction measurements, the (111) and (200) peaks were clearly visible for the fabricated Ni films. The ratio of the integrated intensities of I(111)/I(200) increased with V{sub S}. For V{sub S} = −40 V and B{sub C} = 3 mT, a film resistivity ρ of 8.96 × 10{sup −6} Ω cm was observed, which is close to the Ni bulk value of 6.84 × 10{sup −6} Ω cm. From these results, the authors determined that the structure of the fabricated Ni films on the flexible substrate material was affected by the values of B{sub C} and V{sub S}.

  3. Optimizing LED lighting for space plant growth unit: Joint effects of photon flux density, red to white ratios and intermittent light pulses

    Science.gov (United States)

    Avercheva, O. V.; Berkovich, Yu. A.; Konovalova, I. O.; Radchenko, S. G.; Lapach, S. N.; Bassarskaya, E. M.; Kochetova, G. V.; Zhigalova, T. V.; Yakovleva, O. S.; Tarakanov, I. G.

    2016-11-01

    The aim of this work were to choose a quantitative optimality criterion for estimating the quality of plant LED lighting regimes inside space greenhouses and to construct regression models of crop productivity and the optimality criterion depending on the level of photosynthetic photon flux density (PPFD), the proportion of the red component in the light spectrum and the duration of the duty cycle (Chinese cabbage Brassica chinensis L. as an example). The properties of the obtained models were described in the context of predicting crop dry weight and the optimality criterion behavior when varying plant lighting parameters. Results of the fractional 3-factor experiment demonstrated the share of the PPFD level participation in the crop dry weight accumulation was 84.4% at almost any combination of other lighting parameters, but when PPFD value increased up to 500 μmol m-2 s-1 the pulse light and supplemental light from red LEDs could additionally increase crop productivity. Analysis of the optimality criterion response to variation of lighting parameters showed that the maximum coordinates were the following: PPFD = 500 μmol m-2 s-1, about 70%-proportion of the red component of the light spectrum (PPFDLEDred/PPFDLEDwhite = 1.5) and the duty cycle with a period of 501 μs. Thus, LED crop lighting with these parameters was optimal for achieving high crop productivity and for efficient use of energy in the given range of lighting parameter values.

  4. Generating an AC amplitude magnetic flux density value up to 150 μT at a frequency up to 100 kHz

    Science.gov (United States)

    Ulvr, Michal; Polonský, Jakub

    2017-05-01

    AC magnetic field analyzers with a triaxial coil probe are widely used by health and safety professionals, in manufacturing, and in service industries. For traceable calibration of these analyzers, it is important to be able to generate a stable, homogeneous reference AC magnetic flux density (MFD). In this paper, the generating of AC amplitude MFD value of 150 μT by single-layer Helmholtz type solenoid, described in previous work, was expanded up to a frequency of 100 kHz using the effect of serial resonance. A programmable capacitor array has been developed with a range of adjustable values from 50 pF to 51225 pF. In addition, the multi-layer search coil with a nominal area turns value of 1.3m2, used for adjusting AC MFD in the solenoid, has been modified by a transimpedance amplifier for use in a wider frequency range than up to 3 kHz. The possibility of using the programmable capacitor array up to 150 kHz has also been tested. An AC amplitude MFD value of 150 μT can be generated with expanded uncertainty better than 0.6% up to 100 kHz.

  5. The relationship between the density of alcohol outlets and parental supply of alcohol to adolescents.

    Science.gov (United States)

    Rowland, B; Toumbourou, J W; Satyen, L; Livingston, M; Williams, J

    2014-12-01

    This study investigated whether the number of alcohol outlets per 10,000 population in a given area (density) influenced parental supply of alcohol to adolescents; differences in Australian born and acculturating parents were also examined. A state-representative student survey in Victoria identified that the majority of adolescents (55%) reported that they had used alcohol in the past 12months; 34 % of those who had consumed alcohol reported that it had been supplied by their parents. Multilevel modelling identified that there were no overall effects of density, however there were different effects based on parent country of birth and type of license. Specifically, each unit increase in the density of takeaway liquor stores increased the likelihood by 2.03 that children with both Australian-born parents would be supplied alcohol. Adolescents with both migrant parents on the other hand, had a 1.36 increased risk of being supplied alcohol as the density of outlets requiring at-venue consumption increased. The findings of this study suggest that in Australia, alcohol outlet density is associated with parental supply of alcohol to children, with this effect moderated by the cultural background of the parent and type of outlet density. Future research should investigate the association between the density of alcohol outlets and public approval of parents supplying alcohol to adolescents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Experimental warming in a dryland community reduced plant photosynthesis and soil CO2 efflux although the relationship between the fluxes remained unchanged

    Science.gov (United States)

    Wertin, Timothy M.; Belnap, Jayne; Reed, Sasha C.

    2016-01-01

    1. Drylands represent our planet's largest terrestrial biome and, due to their extensive area, maintain large stocks of carbon (C). Accordingly, understanding how dryland C cycling will respond to climate change is imperative for accurately forecasting global C cycling and future climate. However, it remains difficult to predict how increased temperature will affect dryland C cycling, as substantial uncertainties surround the potential responses of the two main C fluxes: plant photosynthesis and soil CO2 efflux. In addition to a need for an improved understanding of climate effects on individual dryland C fluxes, there is also notable uncertainty regarding how climate change may influence the relationship between these fluxes.2. To address this important knowledge gap, we measured a growing season's in situphotosynthesis, plant biomass accumulation, and soil CO2 efflux of mature Achnatherum hymenoides (a common and ecologically important C3 bunchgrass growing throughout western North America) exposed to ambient or elevated temperature (+2°C above ambient, warmed via infrared lamps) for three years.3. The 2°C increase in temperature caused a significant reduction in photosynthesis, plant growth, and soil CO2 efflux. Of important note, photosynthesis and soil respiration appeared tightly coupled and the relationship between these fluxes was not altered by the elevated temperature treatment, suggesting C fixation's strong control of both above-ground and below-ground dryland C cycling. Leaf water use efficiency was substantially increased in the elevated temperature treatment compared to the control treatment.4. Taken together, our results suggest notable declines in photosynthesis with relatively subtle warming, reveal strong coupling between above- and below-ground C fluxes in this dryland, and highlight temperature's strong effect on fundamental components of dryland C and water cycles.

  7. Relationship between body mass index, bone mineral density, and oral hygiene with periodontal disease in a Mexican elderly group.

    OpenAIRE

    José Francisco Murrieta; Ricardo Gustavo García; Brenda Contreras; Remedios Guadalupe Valdez; María Lilia Juárez

    2016-01-01

    The aim of this study was to evaluate the relationship of body mass index (BMI), bone mineral density (BMD), and oral hygiene with periodontal disease (PD) in a group of elderly adults in Mexico City. Material and Methods: A cross-sectional study with a convenience sample of 151 elderly adults was conducted. Before applying the epidemiological survey, each subject was asked to sign an informed consent. Standardization for measuring Ramfjord’s Periodontal Disease Index (PDI), BMI, and Green an...

  8. The relationship between local density and bond-orientational order during crystallization of the Gaussian core model.

    Science.gov (United States)

    Li, Yan-Wei; Sun, Zhao-Yan

    2016-02-21

    Whether nucleation is triggered by density or by bond-orientational order is one of the most hotly debated issues in recent investigations of the crystallization process. Here, we present a numerical study of the relationship between them for soft particles within the isothermal-isobaric ensemble. We compress the system and thus obtain the fluid-solid transition. By investigating locally dense-packed particles and particles with a relatively high bond-orientational order in the compressing process, we find a sharp increase of the spatial correlations for both densely packed particles and highly bond-orientational ordered particles at the phase transition point, which provide new characterization methods for the liquid-crystal transition. We also find that it is the bond-orientational order rather than density that triggers the nucleation process. The relationship between the local density and the bond-orientational order parameter is strongly affected by the characterization methods used. The local bond order parameter (q6) shows clear correlation with the local density (ρ) in the fluid stage, while the coarse-grained form (q[combining macron]6) does not correlate with ρ at all, owing to the comparable spatial scales of q6 and ρ. Nevertheless, q[combining macron]6 shows an obvious advantage in distinguishing between solid and liquid particles in our work. These results may elevate our understanding of the mechanism of the crystallization process.

  9. ULF power fluctuations in the solar-wind parameters and their relationship with the relativistic electron flux at the geosynchronous orbit

    International Nuclear Information System (INIS)

    Regi, M.

    2016-01-01

    We focused the attention on the Pc5 geomagnetic pulsations in response to the solar wind forcing and their relationship with the relativistic electron flux at geostationary orbit. We present here the results of a correlation analysis between the Pc5 power in the magnetosphere and on the ground, at low and high latitude, and the solar-wind speed and fluctuation power of the interplanetary magnetic field and solar-wind dynamic pressure through the years 2006 to 2010, also showing the relative timing between pulsations and solar-wind parameters. The Pc5 power appears significantly correlated with simultaneous solar-wind pressure fluctuations and with the solar-wind speed lagged by several hours. The relative amplitude of the two correlation peaks depends on the solar cycle phase and on the latitude. We also show a strong relationship between the Pc5 power and the > 600 keV and > 2MeV electron flux at geosynchronous orbit. Clear evidence emerges that the electron flux follows the Pc5 power by about 2 days; the time delay is a bit longer for the higher-energy electrons.

  10. Relationships between electron density, height and sub-peak ionospheric thickness in the night equatorial ionosphere

    Science.gov (United States)

    Lynn, K. J. W.; Harris, T. J.; Sjarifudin, M.

    2006-07-01

    The development and decay of the southern equatorial anomaly night-time peak in electron density as seen at a number of ionosonde reflection points extending from New Guinea and Indonesia into northern Australia was examined in terms of the characteristic rise and fall in height associated with the sunset ionisation-drift vortex at the magnetic equator. The observations relate to measurements made in November 1997. Following sunset, the ionospheric profile was observed to narrow as the maximum electron density increased during a fall in height that took the peak of the layer at Vanimo and Sumedang down to some 240 km. The fall was followed by a strong rise in which the electron density sub-peak profile expanded from a slab width (as given by POLAN) of 20 km to over 100km with no corresponding change in peak electron density. The post-sunset equatorial fall in height and associated changes in profile density and thickness continued to be seen with diminishing amplitude and increasing local time delay in moving from the anomaly peak at Vanimo to the southernmost site of observation at Townsville. Secondary events on a lesser scale sometimes occurred later in the night and may provide evidence of the multiple vortices suggested by Kudeki and Bhattacharyya (1999). Doppler measurements of vertical velocity as seen at Sumedang in Java are compared with the observed changes in electron density profile in the post-sunset period. The normal post-sunset variation in ionospheric parameters was disrupted on the night of 7 November, the night before a negative ionospheric storm was observed.

  11. Relationship of changing social atmosphere, lifestyle and bone mineral density in college students

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Ja; Ko, Yo Han; Kim, Chung Kyung; Kim, Hee Sol; Park, Da Jeong; Yoon, Hyeo Min; Jeong, Yu Jin [Dept. of Radiological Technology, Dongnam Health college, Suwon (Korea, Republic of)

    2013-12-15

    The decrease of bone mineral density gives rise to the outbreak of osteopenia and makes the possibility of a bone fracture. It makes health problems in society. It's very important to prevent osteopenia in advance. Also it's critical to prevent and take care of it in adolescent because it's the most developing period comparing to middle ages because that bone mineral density decreases. There are genetic, physical and environmental factors that affect bone mineral density. Recently, a lifestyle and eating habits are also changing as the society atmosphere is gradually doing. This study have shown that 134 women and 75 men was chosen and responded to the survey of measuring bone mineral density and investigating a lifestyle. The measure of bone mineral density is to use Dual energy X-ray absorptiometry(DEXA) and check femoral neck and lumbar spine. Also questionaries was required to pre-made survey about their lifestyles. Analysis of data was done with SPSS program. Multiple regression analysis was used for the relation of bone mineral density, the heigths and BMI. The sample of Groups are checked for drinking, smoking or excercising about differences by t-test. The results of the experiments were; first, there is statistically significant differences in the comparisons between BMD and BMD. But there isn't any special correlation between drinking, smoking and BMD. Secondly, bone mineral density becomes low related to an intake of caffeine. Particularly, this is statically significant on women. Also there is statically significant correlation between femoral neck and quantity of motion for both men and women. Third, there is significant relation between eating habits and bone mineral density on women's lumbar spine. However, there is no significant relation between men's lumbar spine and women's one. Therefore, to prevent osteopenia, it's good to abstain from intaking caffeine within an hour after a meal. In addition, it

  12. Relationship of changing social atmosphere, lifestyle and bone mineral density in college students

    International Nuclear Information System (INIS)

    Lee, In Ja; Ko, Yo Han; Kim, Chung Kyung; Kim, Hee Sol; Park, Da Jeong; Yoon, Hyeo Min; Jeong, Yu Jin

    2013-01-01

    The decrease of bone mineral density gives rise to the outbreak of osteopenia and makes the possibility of a bone fracture. It makes health problems in society. It's very important to prevent osteopenia in advance. Also it's critical to prevent and take care of it in adolescent because it's the most developing period comparing to middle ages because that bone mineral density decreases. There are genetic, physical and environmental factors that affect bone mineral density. Recently, a lifestyle and eating habits are also changing as the society atmosphere is gradually doing. This study have shown that 134 women and 75 men was chosen and responded to the survey of measuring bone mineral density and investigating a lifestyle. The measure of bone mineral density is to use Dual energy X-ray absorptiometry(DEXA) and check femoral neck and lumbar spine. Also questionaries was required to pre-made survey about their lifestyles. Analysis of data was done with SPSS program. Multiple regression analysis was used for the relation of bone mineral density, the heigths and BMI. The sample of Groups are checked for drinking, smoking or excercising about differences by t-test. The results of the experiments were; first, there is statistically significant differences in the comparisons between BMD and BMD. But there isn't any special correlation between drinking, smoking and BMD. Secondly, bone mineral density becomes low related to an intake of caffeine. Particularly, this is statically significant on women. Also there is statically significant correlation between femoral neck and quantity of motion for both men and women. Third, there is significant relation between eating habits and bone mineral density on women's lumbar spine. However, there is no significant relation between men's lumbar spine and women's one. Therefore, to prevent osteopenia, it's good to abstain from intaking caffeine within an hour after a meal. In addition, it

  13. Relationship of anthropometric measures with bone mineral density in postmenopausal non-osteoporotic, osteopenic and osteoporotic women

    International Nuclear Information System (INIS)

    Tariq, S.; Lone, K.P.

    2017-01-01

    Body mass index (BMI) has been shown to be a more important predictor of bone mineral density (BMD). The objective of this study was to investigate the relationship of anthropometric measures including body mass index with bone mineral density in postmenopausal non-osteoporotic, osteopenic and osteoporotic women. Methods: In this cross sectional study postmenopausal females between 50-70 years of age were recruited and divided into three groups: non-osteoporotic (n=52), osteopenic (n=69) and osteoporotic females (n=47). Anthropometric measures and bone mineral density were assessed. ANOVA was applied to compare groups while Post hoc Tuckey's test was used for multiple comparisons between the groups. Spearman's rho correlation was used to establish correlations. Results: Body mass index (p = 0.034) and hip circumference (p = 0.013) were significantly higher in osteopenic as compared to osteoporotic females and waist to hip ratio was significantly higher (p = 0.005) in osteoporotic as compared to non-osteoporotic females. Significant positive correlation of body mass index was found with T-score (p = 0.022) and ultrasound bone profile index (p< 0.001) in postmenopausal females. Conclusion: High body mass index is associated with high bone mineral density and reduced fracture risk in postmenopausal females. Increasing age and high waist to hip ratio can also lead to reduced bone mineral density in postmenopausal females. (author)

  14. Relationship of anthropometric measures with bone mineral density in postmenopausal non-osteoporotic, osteopenic and osteoporotic women.

    Science.gov (United States)

    Tariq, Sundus; Tariq, Saba; Lone, Khalid Parvez

    2017-04-01

    Body mass index (BMI) has been shown to be a more important predictor of bone mineral density (BMD). The objective of this study was to investigate the relationship of anthropometric measures including body mass index with bone mineral density in postmenopausal non-osteoporotic, osteopenic and osteoporotic women. In this cross sectional study postmenopausal females between 50-70 years of age were recruited and divided into three groups: non-osteoporotic (n=52), osteopenic (n=69) and osteoporotic females (n=47). Anthropometric measures and bone mineral density were assessed. ANOVA was applied to compare groups while Post hoc Tuckey's test was used for multiple comparisons between the groups. Spearman's rho correlation was used to establish correlations. Body mass index (p = 0.034) and hip circumference (p = 0.013) were significantly higher in osteopenic as compared to osteoporotic females and waist to hip ratio was significantly higher (p = 0.005) in osteoporotic as compared to non-osteoporotic females. Significant positive correlation of body mass index was found with T-score (p = 0.022) and ultrasound bone profile index (p< 0.001) in postmenopausal females. High body mass index is associated with high bone mineral density and reduced fracture risk in postmenopausal females. Increasing age and high waist to hip ratio can also lead to reduced bone mineral density in postmenopausal females.

  15. Growth and Accumulation of Secondary Metabolites in Perilla as Affected by Photosynthetic Photon Flux Density and Electrical Conductivity of the Nutrient Solution

    Directory of Open Access Journals (Sweden)

    Na Lu

    2017-05-01

    Full Text Available The global demand for medicinal plants is increasing. The quality of plants grown outdoors, however, is difficult to control. Myriad environmental factors influence plant growth and directly impact biosynthetic pathways, thus affecting the secondary metabolism of bioactive compounds. Plant factories use artificial lighting to increase the quality of medicinal plants and stabilize production. Photosynthetic photon flux density (PPFD and electrical conductivity (EC of nutrient solutions are two important factors that substantially influence perilla (Perilla frutescens, Labiatae plant growth and quality. To identify suitable levels of PPFD and EC for perilla plants grown in a plant factory, the growth, photosynthesis, and accumulation of secondary metabolites in red and green perilla plants were measured at PPFD values of 100, 200, and 300 μmol m-2 s-1 in nutrient solutions with EC values of 1.0, 2.0, and 3.0 dS m-1. The results showed significant interactive effects between PPFD and EC for both the fresh and dry weights of green perilla, but not for red perilla. The fresh and dry weights of shoots and leafy areas were affected more by EC than by PPFD in green perilla, whereas they were affected more by PPFD than by EC in red perilla. Leaf net photosynthetic rates were increased as PPFD increased in both perilla varieties, regardless of EC. The perillaldehyde concentration (mg g-1 in red perilla was unaffected by the treatments, but accumulation in plants (mg per plant was significantly enhanced as the weight of dry leaves increased. Perillaldehyde concentrations in green perilla showed significant differences between combinations of the highest PPFD with the highest EC and the lowest PPFD with the lowest EC. Rosmarinic acid concentration (mg g-1 was increased in a combination of low EC and high PPFD conditions. Optimal cultivation conditions of red and green perilla in plant factory will be discussed in terms of plant growth and contents of

  16. Optimizing LED lighting for space plant growth unit: Joint effects of photon flux density, red to white ratios and intermittent light pulses.

    Science.gov (United States)

    Avercheva, O V; Berkovich, Yu A; Konovalova, I O; Radchenko, S G; Lapach, S N; Bassarskaya, E M; Kochetova, G V; Zhigalova, T V; Yakovleva, O S; Tarakanov, I G

    2016-11-01

    The aim of this work were to choose a quantitative optimality criterion for estimating the quality of plant LED lighting regimes inside space greenhouses and to construct regression models of crop productivity and the optimality criterion depending on the level of photosynthetic photon flux density (PPFD), the proportion of the red component in the light spectrum and the duration of the duty cycle (Chinese cabbage Brassica сhinensis L. as an example). The properties of the obtained models were described in the context of predicting crop dry weight and the optimality criterion behavior when varying plant lighting parameters. Results of the fractional 3-factor experiment demonstrated the share of the PPFD level participation in the crop dry weight accumulation was 84.4% at almost any combination of other lighting parameters, but when PPFD value increased up to 500µmol m -2 s -1 the pulse light and supplemental light from red LEDs could additionally increase crop productivity. Analysis of the optimality criterion response to variation of lighting parameters showed that the maximum coordinates were the following: PPFD = 500µmol m -2 s -1 , about 70%-proportion of the red component of the light spectrum (PPFD LEDred /PPFD LEDwhite = 1.5) and the duty cycle with a period of 501µs. Thus, LED crop lighting with these parameters was optimal for achieving high crop productivity and for efficient use of energy in the given range of lighting parameter values. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  17. Density and Habitat Relationships of the Endemic White Mountain Fritillary (Boloria chariclea montinus (Lepidoptera: Nymphalidae

    Directory of Open Access Journals (Sweden)

    Kent P. McFarland

    2017-06-01

    Full Text Available We conducted point counts in the alpine zone of the Presidential Range of the White Mountains, New Hampshire, USA, to estimate the distribution and density of the rare endemic White Mountain Fritillary (Boloria chariclea montinus. Incidence of occurrence and density of the endemic White Mountain Fritillary during surveys in 2012 and 2013 were greatest in the herbaceous-snowbank plant community. Densities at points in the heath-shrub-rush plant community were lower, but because this plant community is more widespread in the alpine zone, it likely supports the bulk of adult fritillaries. White Mountain Fritillary used cushion-tussock, the other alpine plant community suspected of providing habitat, only sparingly. Detectability of White Mountain Fritillaries varied as a consequence of weather conditions during the survey and among observers, suggesting that raw counts yield biased estimates of density and abundance. Point counts, commonly used to study and monitor populations of birds, were an effective means of sampling White Mountain Fritillary in the alpine environment where patches of habitat are small, irregularly shaped, and widely spaced, rendering line-transect methods inefficient and difficult to implement.

  18. Relationships between overstory composition and gypsy moth egg-mass density

    Science.gov (United States)

    Robert W. Campbell

    1974-01-01

    Most of the silvicultural recommendations for reducing the hazard of gypsy moth outbreaks have been based in part on the premise that gypsy moth density levels are related closely to the proportion of favored food trees in the overstory. This premise did not prove to be true for a series of plots observed in eastern New England between 1911 and 1931.

  19. Spatial relationship between human population density, land use intensity and biodiversity in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Vačkář, David; Chobot, K.; Orlitová, E.

    2012-01-01

    Roč. 27, č. 9 (2012), s. 1279-1290 ISSN 0921-2973 Institutional support: RVO:67179843 Keywords : species richness * landscape diversity * human population density * human appropriation of net primary production * Czech Republic Subject RIV: EH - Ecology, Behaviour Impact factor: 2.897, year: 2012

  20. A study of the characteristics of energy flux and its relationship with the summer monsoon over alpine wetlands in the source region of the Yellow River

    Science.gov (United States)

    Jia, Dongyu; Wen, Jun; Ma, Yaoming; Zhou, Juan; Chen, Jinlei; Liu, Rong; Wang, Xin; Zhang, Tangtang; Lai, Xin; Wang, ZuoLiang

    2017-11-01

    The variation trends of sensible heat (SH) and latent heat (LH) flux over the alpine wetlands in the source region of the Yellow River (SRYR) have been altered in the past 30 years. The variations in the surface heat source and its influence on the plateau summer monsoon have become attractive and important. The Community Land Model version 4.5 (CLM4.5), driven by the forcing data from CRUNCEP, was used to simulate the spatio-temporal variation characteristics of the SH and LH from 1980 to 2010 over the SRYR. The simulated SH and LH are compared to the situ measurements of the Maduo climatic monitoring station from the Northwest Institute of Eco-Environment and Resources. In addition, the relationships between the SH, LH and plateau summer monsoon have also been analysed. The results show that the seasonal mean SH reaches its maximum in spring and its minimum in winter. For the annual SH, there is an increasing trend in the early period and then a decreasing trend, while the variation trends of the LH are opposite to those of the SH flux. In addition, the LH transfer in summer reaches a maximum; the SH flux in the northern SRYR was higher in spring and summer. The SH of the two lakes, Lake Gyaring and Lake Ngoring, are significantly smaller than those of the surrounding areas. For the spatial distributions of the annual mean flux, the SH flux presented larger values over the central SRYR, while it presented smaller values in the southern areas. The LH shows an increasing trend from the northwest to the southeast of the SRYR. Meanwhile, the LH transport over the two lakes is notably higher than those of the surrounding areas. The time series of SH amplitude shows that it changes every 6-10 a. The SH amplitude is a mostly positive anomaly in the spatial distribution of the first pattern. EOF2 shows a high west of 101°E and a low centre east of 101°E; the relationship between the SH in spring and the different plateau summer monsoon indices are negatively correlated

  1. Do neighborhood attributes moderate the relationship between alcohol establishment density and crime?

    Science.gov (United States)

    Erickson, Darin J; Carlin, Bradley P; Lenk, Kathleen M; Quick, Harrison S; Harwood, Eileen M; Toomey, Traci L

    2015-02-01

    Although numerous studies have found a positive association between the density of alcohol establishments and various types of crime, few have examined how neighborhood attributes (e.g., schools, parks) could moderate this association. We used data from Minneapolis, MN with neighborhood as the unit of analysis (n = 83). We examined eight types of crime (assault, rape, robbery, vandalism, nuisance crime, public alcohol consumption, driving while intoxicated, underage alcohol possession/consumption) and measured density as the total number of establishments per roadway mile. Neighborhood attributes assessed as potential moderators included non-alcohol businesses, schools, parks, religious institutions, neighborhood activism, neighborhood quality, and number of condemned houses. Using Bayesian techniques, we created a model for each crime outcome (accounting for spatial auto-correlation and controlling for relevant demographics) with an interaction term (moderator × density) to test each potential moderating effect. Few interaction terms were statistically significant. The presence of at least one college was the only neighborhood attribute that consistently moderated the density-crime association, with the presence of a college attenuating the association between the density and three types of crime (assaults, nuisance crime, and public consumption). However, caution should be used when interpreting the moderating effect of college presence because of the small number of colleges in our sample. The lack of moderating effects of neighborhood attributes, except for presence of a college, suggests that the addition of alcohol establishments to any neighborhood, regardless of its other attributes, could result in an increase in a wide range of crime.

  2. Relationship between CT number and electron density, scatter angle and nuclear reaction for hadron-therapy treatment planning

    International Nuclear Information System (INIS)

    Matsufuji, N.; Tomura, H.; Futami, Y.; Yamashita, H.; Kanai, T.; Higashi, A.; Minohara, S.; Endo, M.

    1998-01-01

    The precise conversion of CT numbers to their electron densities is essential in treatment planning for hadron therapy. Although some conversion methods have already been proposed, it is hard to check the conversion accuracy during practical therapy. We have estimated the CT numbers of real tissues by a calculational method established by Mustafa and Jackson. The relationship between the CT numbers and the electron densities was investigated for various body tissues as well as some tissue-equivalent materials used for a conversion to check the accuracy of the current conversion methods. The result indicates a slight disagreement at the high-CT-number region. A precise estimation of the multiple scattering, nuclear reaction and range straggling of incident particles has been considered as being important to realize higher-level conformal therapy in the future. The relationship between these parameters and the CT numbers was also investigated for tissues and water. The result shows that it is sufficiently practical to replace these parameters for real tissues with those for water by adjusting the density. (author)

  3. Do galaxy global relationships emerge from local ones? The SDSS IV MaNGA surface mass density-metallicity relation

    Science.gov (United States)

    Barrera-Ballesteros, Jorge K.; Heckman, Timothy M.; Zhu, Guangtun B.; Zakamska, Nadia L.; Sánchez, Sebastian F.; Law, David; Wake, David; Green, Jenny E.; Bizyaev, Dmitry; Oravetz, Daniel; Simmons, Audrey; Malanushenko, Elena; Pan, Kaike; Roman Lopes, Alexandre; Lane, Richard R.

    2016-12-01

    We present the stellar surface mass density versus gas metallicity (Σ*-Z) relation for more than 500 000 spatially resolved star-forming resolution elements (spaxels) from a sample of 653 disc galaxies included in the SDSS IV MaNGA survey. We find a tight relation between these local properties, with higher metallicities as the surface density increases. This relation extends over three orders of magnitude in the surface mass density and a factor of 4 in metallicity. We show that this local relationship can simultaneously reproduce two well-known properties of disc galaxies: their global mass-metallicity relationship and their radial metallicity gradients. We also find that the Σ*-Z relation is largely independent of the galaxy's total stellar mass and specific star formation rate (sSFR), except at low stellar mass and high sSFR. These results suggest that in the present-day universe local properties play a key role in determining the gas-phase metallicity in typical disc galaxies.

  4. The Relationship of Gamma Immunoglobin (IgG) Density and Apgar ...

    African Journals Online (AJOL)

    The transfer of maternal IgG provides the neonate with humoral immunity during early life. The population of transferred IgG or IgG density (IgGρ) was estimated to find out if it has any relevance to the condition of an infant 1-5 minutes after birth or APGAR score which gives an insight into the state of health of the infant and ...

  5. Successional change in phosphorus stoichiometry explains the inverse relationship between herbivory and lupin density on Mount St. Helens.

    Directory of Open Access Journals (Sweden)

    Jennifer L Apple

    2009-11-01

    Full Text Available The average nitrogen-to-phosphorus ratio (NratioP of insect herbivores is less than that of leaves, suggesting that P may mediate plant-insect interactions more often than appreciated. We investigated whether succession-related heterogeneity in N and P stoichiometry influences herbivore performance on N-fixing lupin (Lupinus lepidus colonizing primary successional volcanic surfaces, where the abundances of several specialist lepidopteran herbivores are inversely related to lupin density and are known to alter lupin colonization dynamics. We examined larval performance in response to leaf nutritional characteristics using gelechiid and pyralid leaf-tiers, and a noctuid leaf-cutter.We conducted four studies. First, growth of larvae raised on wild-collected leaves responded positively to leaf %P and negatively to leaf carbon (%C, but there was no effect of %N or quinolizidine alkaloids (QAs. Noctuid survival was also positively related to %P. Second, we raised gelechiid larvae on greenhouse-grown lupins with factorial manipulation of competitors and soil N and P. In the presence of competition, larval mass was highest at intermediate leaf NratioP and high %P. Third, survival of gelechiid larvae placed on lupins in high-density patches was greater when plant competitors were removed than on controls. Fourth, surveys of field-collected leaves in 2000, 2002, and 2003 indicated that both %P and %N were generally greater in plants from low-density areas. QAs in plants from low-density areas were equal to or higher than QAs in high-density areas.Our results demonstrate that declines in lupin P content under competitive conditions are associated with decreased larval growth and survival sufficient to cause the observed negative relationship between herbivore abundance and host density. The results support the theoretical finding that declines in stoichiometric resource quality (caused here by succession have the potential to cause a decrease in consumer

  6. Observed relationships between wood density and solution uptake during pressure treatment

    Science.gov (United States)

    Steve Halverson; Stan Lebow

    2011-01-01

    A better understanding of the relationship between wood properties and solution uptake during pressure treatment could lead to improvements in treatment quality and more efficient use of preservatives. In this study several years of treatment data representing a range of wood species, charge conditions and preservative formulations were analyzed to evaluate the...

  7. Relationships between ecosystem metabolism, benthic macroinvertebrate densities, and environmental variables in a sub-arctic Alaskan river

    Science.gov (United States)

    Benson, Emily R.; Wipfli, Mark S.; Clapcott, Joanne E.; Hughes, Nicholas F.

    2013-01-01

    Relationships between environmental variables, ecosystem metabolism, and benthos are not well understood in sub-arctic ecosystems. The goal of this study was to investigate environmental drivers of river ecosystem metabolism and macroinvertebrate density in a sub-arctic river. We estimated primary production and respiration rates, sampled benthic macroinvertebrates, and monitored light intensity, discharge rate, and nutrient concentrations in the Chena River, interior Alaska, over two summers. We employed Random Forests models to identify predictor variables for metabolism rates and benthic macroinvertebrate density and biomass, and calculated Spearman correlations between in-stream nutrient levels and metabolism rates. Models indicated that discharge and length of time between high water events were the most important factors measured for predicting metabolism rates. Discharge was the most important variable for predicting benthic macroinvertebrate density and biomass. Primary production rate peaked at intermediate discharge, respiration rate was lowest at the greatest time since last high water event, and benthic macroinvertebrate density was lowest at high discharge rates. The ratio of dissolved inorganic nitrogen to soluble reactive phosphorus ranged from 27:1 to 172:1. We found that discharge plays a key role in regulating stream ecosystem metabolism, but that low phosphorous levels also likely limit primary production in this sub-arctic stream.

  8. The relationship between bone mineral density and serum PTH, BGP and CT levels in patients with hyperthyroidism

    International Nuclear Information System (INIS)

    Zhang Xuefeng; Cui Kai; Jiang Qiuju; Li Chunhui

    2008-01-01

    To explore the relationship between the bone mineral density (BMD) and serum PTH, BGP and CT levels in patients with hyperthyroidism. The serum levels of BGP, CT and PTH in 167 patients with hyperthyroidism and 58 normal controls were determined by RIA. The results showed that the serum CT levels and BMD in patients with hyperthyroidism were significantly lower than those in the control group (P<0.01). The serum levels of PTH and BGP in patients were significantly higher than those in the control group (P<0.01). The BMD in patients with hyperthyroidism was related to the serum levels of PTH, BGP and CT. (authors)

  9. MHD-IPS analysis of relationship among solar wind density, temperature, and flow speed

    Science.gov (United States)

    Hayashi, Keiji; Tokumaru, Munetoshi; Fujiki, Ken'ichi

    2016-08-01

    The solar wind properties near the Sun are a decisive factor of properties in the rest of heliosphere. As such, determining realistic plasma density and temperature near the Sun is very important in models for solar wind, specifically magnetohydrodynamics (MHD) models. We had developed a tomographic analysis to reconstruct three-dimensional solar wind structures that satisfy line-of-sight-integrated solar wind speed derived from the interplanetary scintillation (IPS) observation data and nonlinear MHD equations simultaneously. In this study, we report a new type of our IPS-MHD tomography that seeks three-dimensional MHD solution of solar wind, matching additionally near-Earth and/or Ulysses in situ measurement data for each Carrington rotation period. In this new method, parameterized relation functions of plasma density and temperature at 50 Rs are optimized through an iterative forward model minimizing discrepancy with the in situ measurements. Satisfying three constraints, the derived 50 Rs maps of plasma quantities provide realistic observation-based information on the state of solar wind near the Sun that cannot be well determined otherwise. The optimized plasma quantities exhibit long-term variations over the solar cycles 21 to 24. The differences in plasma quantities derived from the optimized and original IPS-MHD tomography exhibit correlations with the source-surface magnetic field strength, which can in future give new quantitative constrains and requirements to models of coronal heating and acceleration.

  10. The relationship between absorbency and density of bioplastic film made from hydrolyzed starch

    Science.gov (United States)

    Singan, Grace; Chiang, Liew Kang

    2017-12-01

    Water absorption in polymer blends such as starch-based bioplastic films is important to evaluate the stability characteristics of such films in water that will affect their long-term performance in final products. In this study, the absorbency of starch-based bioplastic films made from potato, cassava, and corn starches that have went through the hydrolysis process first to alter its characteristics and properties in terms of granular swelling and hydrophilicity behaviour. The final results showed that hydrolyzed cassava bioplastic film has the ability to absorb more water compared to hydrolyzed potato and corn bioplastic films. The reading of hydrolyzed cassava bioplastic film on the seventh day of immersion for all ratios were between 87.83 % to 131.29 %, while for hydrolyzed potato bioplastic films was 69.48 % to 92.41 % and hydrolyzed corn bioplastic films was 66.28 % to 74.18 %. Meanwhile, the density analysis was evaluated to determine its physical properties towards moisture condition. The results showed that the hydrolyzed cassava bioplastic films have higher density compared to the other two, which indicated that it is a more favourable raw material to produce biodegradable planting pot due to its ability to absorb more water. Hence, still manage to retain its shape with low brittle surface.

  11. A cross-sectional analysis of the relationship between tobacco and alcohol outlet density and neighbourhood deprivation.

    Science.gov (United States)

    Shortt, Niamh K; Tisch, Catherine; Pearce, Jamie; Mitchell, Richard; Richardson, Elizabeth A; Hill, Sarah; Collin, Jeff

    2015-10-05

    There is a strong socio-economic gradient in both tobacco-and alcohol-related harm. One possible factor contributing to this social gradient may be greater availability of tobacco and alcohol in more socially-deprived areas. A higher density of tobacco and alcohol outlets is not only likely to increase supply but also to raise awareness of tobacco/alcohol brands, create a competitive local market that reduces product costs, and influence local social norms relating to tobacco and alcohol consumption. This paper examines the association between the density of alcohol and tobacco outlets and neighbourhood-level income deprivation. Using a national tobacco retailer register and alcohol licensing data this paper calculates the density of alcohol and tobacco retail outlets per 10,000 population for small neighbourhoods across the whole of Scotland. Average outlet density was calculated for neighbourhoods grouped by their level of income deprivation. Associations between outlet density and deprivation were analysed using one way analysis of variance. There was a positive linear relationship between neighbourhood deprivation and outlets for both tobacco (p tobacco and both off-sales and on-sales alcohol outlets. The social gradient evident in alcohol and tobacco supply may be a contributing factor to the social gradient in alcohol- and tobacco-related disease. Policymakers should consider such gradients when creating tobacco and alcohol control policies. The potential contribution to public health, and health inequalities, of reducing the physical availability of both alcohol and tobacco products should be examined in developing broader supply-side interventions.

  12. Relationship between enhanced intensity of contrast enhanced ultrasound and microvessel density of aortic atherosclerostic plaque in rabbit model.

    Directory of Open Access Journals (Sweden)

    Xiangdong You

    Full Text Available The aim of this study was to evaluate the relationship between enhanced intensity of contrast enhanced ultrasound and microvessel density of aortic atherosclerotic plaque in rabbit model. The abdominal aortas of thirty-six male New Zealand rabbits were damaged by balloon expansion and the animals were then fed a high fat diet for 12 weeks. Twenty-seven plaques on the near aortic wall were detected using conventional ultrasound examination. The maximum thickness of each plaque was recorded. CEUS was performed on these 27 plaques and the time-intensity curves (TICs were analyzed offline. Using the quantitative ACQ software, features such as the arrival time (AT, time to peak (TTP, baseline intensity (BI, peak intensity (PI and enhanced intensity (EI (EI = PI-BI were assessed. Inter- and intra-observer agreement of EI were assessed using the Bland-Altman test. After CEUS examination, the rabbits were sacrificed for pathological examination and CD34 monoclonal antibody immunohistochemical detection. Microvessel density (MVD was counted under the microscope. The relationship between indexes of CEUS and the level of MVD was analyzed. There was a good positive linear correlation between EI and MVD (γ = 0. 854, P<0. 001, the intraclass correlations for inter- and intra-observer agreement for EI were 0.73 and 0.82 respectively, suggesting that EI may be act as a useful index for plaque risk stratification in animal models.

  13. The relationship between minimum alcohol prices, outlet densities and alcohol-attributable deaths in British Columbia, 2002-09.

    Science.gov (United States)

    Zhao, Jinhui; Stockwell, Tim; Martin, Gina; Macdonald, Scott; Vallance, Kate; Treno, Andrew; Ponicki, William R; Tu, Andrew; Buxton, Jane

    2013-06-01

    To investigate relationships between periodic increases in minimum alcohol prices, changing densities of liquor stores and alcohol-attributable (AA) deaths in British Columbia, Canada. Cross-section (16 geographic areas) versus time-series (32 annual quarters) panel analyses were conducted with AA deaths as dependent variables and price, outlet densities and socio-demographic characteristics as independent variables. Populations of 16 Health Service Delivery Areas in British Columbia, Canada. Age-sex-standardized rates of acute, chronic and wholly AA mortality; population densities of restaurants, bars, government and private liquor stores; minimum prices of alcohol in dollars per standard drink. A 10% increase in average minimum price for all alcoholic beverages was associated with a 31.72% [95% confidence interval (CI): ± 25.73%, P stores was associated with a 2.45% (95% CI: ± 2.39%, P stores were associated with increases in alcohol-attributable mortality. © 2013 The Authors, Addiction © 2013 Society for the Study of Addiction.

  14. Decoupling Substrate Stiffness, Spread Area, and Micropost Density: A Close Spatial Relationship between Traction Forces and Focal Adhesions

    Science.gov (United States)

    Han, Sangyoon J.; Bielawski, Kevin S.; Ting, Lucas H.; Rodriguez, Marita L.; Sniadecki, Nathan J.

    2012-01-01

    Mechanical cues can influence the manner in which cells generate traction forces and form focal adhesions. The stiffness of a cell’s substrate and the available area on which it can spread can influence its generation of traction forces, but to what extent these factors are intertwined is unclear. In this study, we used microcontact printing and micropost arrays to control cell spreading, substrate stiffness, and post density to assess their effect on traction forces and focal adhesions. We find that both the spread area and the substrate stiffness influence traction forces in an independent manner, but these factors have opposite effects: cells on stiffer substrates produce higher average forces, whereas cells with larger spread areas generate lower average forces. We show that post density influences the generation of traction forces in a manner that is more dominant than the effect of spread area. Additionally, we observe that focal adhesions respond to spread area, substrate stiffness, and post density in a manner that closely matches the trends seen for traction forces. This work supports the notion that traction forces and focal adhesions have a close relationship in their response to mechanical cues. PMID:22947925

  15. Investigation of the relationship between low environmental exposure to metals and bone mineral density, bone resorption and renal function.

    Science.gov (United States)

    Callan, A C; Devine, A; Qi, L; Ng, J C; Hinwood, A L

    2015-07-01

    Environmental exposure to metals has been linked to adverse health outcomes. Exposure to cadmium has been associated with decreased bone density, an increased risk of osteoporotic fracture and possible renal dysfunction. Older women are a group at risk of renal and bone density impacts and exposure to metals may be an important risk factor for these health outcomes. This study was a cross sectional study of 77 women aged 50 years and above examining the relationship between metals exposure and renal and bone health. Urinary and blood metals concentrations, plasma creatinine, iron, ferritin and transferrin were measured in these subjects. Bone biomarkers assessed included the pyridinium crosslinks, pyridinoline and deoxypyridinoline measured by ELISA. Renal function was assessed using eGFR and KIM-1. Whole body, hip and lumbar spine bone mineral density was assessed using DEXA. Blood and urinary metals concentrations were generally low in the subjects, with a median urinary cadmium concentration of 0.26 μg/g creatinine (range aluminium concentrations were positively correlated with bone resorption whilst blood zinc and mercury concentrations were negatively correlated. Urinary aluminium was positively correlated with KIM-1 concentrations, a marker of early kidney damage, however blood zinc concentrations were significantly negatively correlated with this biomarker. This study provides additional support for low cadmium exposure being of concern for the health of older women. Further investigation into the role of exposure to other metals on bone and renal health is warranted. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. Relationship between bone mineral density and alcohol intake: A nationwide health survey analysis of postmenopausal women.

    Directory of Open Access Journals (Sweden)

    Hae-Dong Jang

    Full Text Available Among a variety of relevant factors of osteoporosis, the association between alcohol intake and postmenopausal women's bone mineral density (BMD by using data from the Korean National Health and Nutrition Examination Survey was evaluated in this study.Among a total of 31,596 subjects, males, premenopausal women, participants without BMD data were excluded. Finally, a total number of subjects in the study was 3,312. The frequency and amount of alcohol intake were determined by self-reported questionnaires, and BMD was measured by dual-energy x-ray absorptiometry.Mean femoral BMD for light drinkers was statistically significantly greater than that for heavy drinkers and non-drinkers. We observed the characteristic trends for BMD by drinking frequency; the mean BMD gradually increased from non-drinkers to the participants who drank 2-3 times per week; these participants exhibited the highest BMD. Participants who drank alcohol greater than 4 times per week showed a lower BMD. In the risk factor analysis, the adjusted odds ratio for osteoporosis (at femoral neck was 1.68 in non-drinkers and 1.70 in heavy drinkers compared with light drinkers.Light alcohol intake (2-3 times per week and 1-2 or 5-6 glasses per occasion in South Korean postmenopausal women was related to high femoral BMD. Non-drinkers and heavy drinkers had approximately a 1.7-times greater risk for osteoporosis than light drinkers.

  17. Relationship between oxidized low-density lipoprotein antibodies and obesity in different glycemic situations

    Directory of Open Access Journals (Sweden)

    Babakr AT

    2014-10-01

    Full Text Available Abdullatif Taha Babakr,1 Osman Mohamed Elsheikh,2 Abdullah A Almarzouki,3 Adel Mohamed Assiri,1 Badr Eldin Elsonni Abdalla,4 Hani Yousif Zaki,5 Samir H Fatani,1 EssamEldin Mohamed NourEldin11Department of Medical Biochemistry, Faculty of Medicine, Umm Al-Qura University, Makkah, Kingdom of Saudi Arabia; 2Department of Biochemistry, Faculty of Medicine, International University of Africa, Khartoum, Sudan; 3Department of Internal Medicine, Faculty of Medicine, Umm Al-Qura University, Makkah, 4Department of Biochemistry, Sciences Faculty for Girls, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 5Department of Biochemistry and Nutrition, Faculty of Medicine, University of Gezira, Sudan Background: Autoantibodies to oxidized low-density lipoprotein (oxLDL are a heterogeneous group of antibodies that are controversially discussed to be either pathogenic or protective. Biochemical and anthropometric measurements correlated with increased levels of these antibodies are also controversial, especially in conditions of impaired glucose tolerance and type 2 diabetes mellitus. The present study was conducted to evaluate levels of oxLDL antibodies and their correlation with obesity in different glycemic situations. Methods: Two hundred and seventy-four adult males were classified into three subgroups: group 1 (n=125, comprising a control group of nondiabetic subjects; group 2 (n=77, comprising subjects with impaired glucose tolerance; and group 3 (n=72, comprising patients with type 2 diabetes mellitus. Body mass index was calculated, and measurement of oxLDL and oxLDL antibodies was performed. Results: Higher mean concentrations of oxLDL were found in the type 2 diabetes mellitus and impaired glucose tolerance groups (143.5±21.9 U/L and 108.7±23.7 U/L, respectively. The mean value for the control group was 73.5±27.5 U/L (P<0.001. Higher mean concentrations of anti-oxLDL antibodies were observed in the type 2 diabetes mellitus and impaired

  18. Lack of relationship between glycemic control and bone mineral density in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    D.M.S.L. Cutrim

    2007-02-01

    Full Text Available We assessed the effect of chronic hyperglycemia on bone mineral density (BMD and bone remodeling in patients with type 2 diabetes mellitus. We investigated 42 patients with type 2 diabetes under stable control for at least 1 year, 22 of them with good metabolic control (GMC: mean age = 48.8 ± 1.5 years, 11 females and 20 with poor metabolic control (PMC: mean age = 50.2 ± 1.2 years, 8 females, and 24 normal control individuals (CG: mean age = 46.5 ± 1.1 years, 14 females. We determined BMD in the femoral neck and at the L2-L4 level (DEXA and serum levels of glucose, total glycated hemoglobin (HbA1, total and ionic calcium, phosphorus, alkaline phosphatase, follicle-stimulating hormone, intact parathyroid hormone (iPTH, 25-hydroxyvitamin D (25-OH-D, insulin-like growth factor I (IGFI, osteocalcin, procollagen type I C propeptide, as well as urinary levels of deoxypyridinoline and creatinine. HbA1 levels were significantly higher in PMC patients (12.5 ± 0.6 vs 7.45 ± 0.2% for GMC and 6.3 ± 0.9% for CG; P < 0.05. There was no difference in 25-OH-D, iPTH or IGFI levels between the three groups. BMD values at L2-L4 (CG = 1.068 ± 0.02 vs GMC = 1.170 ± 0.03 vs PMC = 1.084 ± 0.02 g/cm² and in the femoral neck (CG = 0.898 ± 0.03 vs GMC = 0.929 ± 0.03 vs PMC = 0.914 ± 0.03 g/cm² were similar for all groups. PMC presented significantly lower osteocalcin levels than the other two groups, whereas no significant difference in urinary deoxypyridine was observed between groups. The present results demonstrate that hyperglycemia is not associated with increased bone resorption in type 2 diabetes mellitus and that BMD is not altered in type 2 diabetes mellitus.

  19. Relationship between Relativistic Electron Flux in the Inner Magnetosphere and ULF Pulsation on the Ground Associated with Long-term Variations of Solar Wind

    Science.gov (United States)

    Kitamura, K.; Nagatsuma, T.; Troshichev, O. A.; Obara, T.; Koshiishi, H.; Saita, S.; Yoshikawa, A.; Yumoto, K.

    2014-12-01

    In the present study the relativistic electron flux (0.59-1.18MeV) measured by Standard Dose Monitor (SDOM) onboard DRTS (KODAMA) satellite at the Geostationary Earth Orbit (GEO) is analyzed to investigate the long term (from 2002 to 2014) variations of the electron flux enhancement (REF) during the passage of Corotating Interaction Regions (CIRs) and/or Coronal Mass Ejection (CMEs). The long term variations of the REF clearly shows the 27-days period associated with the high speed solar wind velocity caused by the CIRs, whereas it is very few that the enhancement of REF lasts for several days after passage of CMEs. The 27-days period enhancement of REF represents the quite strong peak in 2003 when the high speed stream of the solar wind were quit active. We also conducted the same analysis for the Pc5 pulsations observed on the ground. The ground magnetic variations data globally observed by National Institute of Information and Communications Technology (NICT) and International Center for Space Weather Science and Education (ICSWSE) Kyushu University are used to investigate the long term variations of Pc5 power. The same signature in the REF variations is shown in the time variability of the Pc5 power on the ground. These results indicate that the solar wind condition strongly affects the acceleration process of the relativistic electron flux by the ULF wave. In particular the dependence of the REF and Pc5 variations on the sector structures and their seasonal variations strongly suggest that the relationship between Pc5 and REF variations could be controlled by the Russell-McPherron effect.

  20. Relationship between evapotranspiration and precipitation pulses in a semiarid rangeland estimated by moisture flux towers and MODIS vegetation indices

    Science.gov (United States)

    Nagler, P.L.; Glenn, E.P.; Kim, H.; Emmerich, W.; Scott, R.L.; Huxman, T. E.; Huete, A.R.

    2007-01-01

    We used moisture Bowen ratio flux tower data and the enhanced vegetation index (EVI) from the moderate resolution imaging spectrometer (MODIS) on the Terra satellite to measure and scale evapotranspiration (ET) over sparsely vegetated grassland and shrubland sites in a semiarid watershed in southeastern Arizona from 2000 to 2004. The grassland tower site had higher mean annual ET (336 mm yr-1) than the shrubland tower site (266 mm yr-1) (Pequation. The regression equation relating ET to EVI and P was used to scale ET over 25 km2 areas of grassland and shrubland around each tower site. Over the study, ratios of T to ET ranged from 0.75 to 1.0. Winter rains stimulated spring ET, and a large rain event in fall, 2000, stimulated ET above T through the following year, indicating that winter rain stored in the soil profile can be an important component of the plants' water budget during the warm season in this ecosystem. We conclude that remotely sensed vegetation indices can be used to scale ground measurements of ET over larger landscape units in semiarid ranglelands, and that the vegetation communities in this landscape effectively harvest the available precipitation over a period of years, even though precipitation patterns are variably seasonally and interannually. ?? 2007 Elsevier Ltd. All rights reserved.

  1. Influence of stability on the flux-profile relationships for wind speed, Φm, and temperature, Φh, for the stable atmospheric boundary layer

    Directory of Open Access Journals (Sweden)

    C. Yagüe

    2006-01-01

    Full Text Available Data from SABLES98 experimental campaign have been used in order to study the influence of stability (from weak to strong stratification on the flux-profile relationships for momentum, Φm, and heat, Φh. Measurements from 14 thermocouples and 3 sonic anemometers at three levels (5.8, 13.5 and 32 m for the period from 10 to 28 September 1998 were analysed using the framework of the local-scaling approach (Nieuwstadt, 1984a; 1984b, which can be interpreted as an extension of the Monin-Obukhov similarity theory (Obukhov, 1946. The results show increasing values of Φm and Φh with increasing stability parameter ζ=z/Λ, up to a value of ζ≈1–2, above which the values remain constant. As a consequence of this levelling off in Φm and Φh for strong stability, the turbulent mixing is underestimated when linear similarity functions (Businger et al., 1971 are used to calculate surface fluxes of momentum and heat. On the other hand when Φm and Φh are related to the gradient Richardson number, Ri, a different behaviour is found, which could indicate that the transfer of momentum is greater than that of heat for high Ri. The range of validity of these linear functions is discussed in terms of the physical aspects of turbulent intermittent mixing.

  2. Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values.

    Directory of Open Access Journals (Sweden)

    Gábor Holló

    Full Text Available To compare the relationship of Octopus perimeter cluster mean-defect (cluster MD values with the spatially corresponding optical coherence tomography (OCT sector peripapillary angioflow vessel-density (PAFD and sector retinal nerve fiber layer thickness (RNFLT values.High quality PAFD and RNFLT images acquired on the same day with the Angiovue/RTVue-XR Avanti OCT (Optovue Inc., Fremont, USA on 1 eye of 27 stable early-to-moderate glaucoma, 22 medically controlled ocular hypertensive and 13 healthy participants were analyzed. Octopus G2 normal visual field test was made within 3 months from the imaging.Total peripapillary PAFD and RNFLT showed similar strong positive correlation with global mean sensitivity (r-values: 0.6710 and 0.6088, P<0.0001, and similar (P = 0.9614 strong negative correlation (r-values: -0.4462 and -0.4412, P≤0.004 with global MD. Both inferotemporal and superotemporal sector PAFD were significantly (≤0.039 lower in glaucoma than in the other groups. No significant difference between the corresponding inferotemporal and superotemporal parameters was seen. The coefficient of determination (R2 calculated for the relationship between inferotemporal sector PAFD and superotemporal cluster MD (0.5141, P<0.0001 was significantly greater than that between inferotemporal sector RNFLT and superotemporal cluster MD (0.2546, P = 0.0001. The R2 values calculated for the relationships between superotemporal sector PAFD and RNFLT, and inferotemporal cluster MD were similar (0.3747 and 0.4037, respectively, P<0.0001.In the current population the relationship between inferotemporal sector PAFD and superotemporal cluster MD was strong. It was stronger than that between inferotemporal sector RNFLT and superotemporal cluster MD. Further investigations are necessary to clarify if our results are valid for other populations and can be usefully applied for glaucoma research.

  3. Relationships Between Tropical Deep Convection, Tropospheric Mean Temperature and Cloud-Induced Radiative Fluxes on Intraseasonal Time Scales

    Science.gov (United States)

    Ramey, Holly S.; Robertson, Franklin R.

    2010-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of variability in the organization of tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, we examine the projection of ISOs on the tropically-averaged temperature and energy budget. The area of interest is the global oceans between 20degN/S. Our analysis then focuses on these questions: (i) How is tropospheric temperature related to tropical deep convection and the associated ice cloud fractional amount (ICF) and ice water path (IWP)? (ii) What is the source of moisture sustaining the convection and what role does deep convection play in mediating the PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007) with some modifications and some additional diagnostics of both clouds and boundary layer thermodynamics. A composite ISO time series of cloud, precipitation and radiation quantities built from nearly 40 events during a six-year period is referenced to the atmospheric temperature signal. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. While there is a decrease in net TOA radiation that develops after the peak in deep convective rainfall, there seems little evidence that an "Infrared Iris"- like mechanism is dominant. Rather, the cloud-induced OLR increase seems largely produced by weakened convection with warmer cloud tops. Tropical ISO events offer an accessible target for studying ISOs not just in terms of propagation mechanisms, but on their global signals of heat, moisture and radiative flux feedback processes.

  4. The Entropy Solutions for the Lighthill-Whitham-Richards Traffic Flow Model with a Discontinuous Flow-Density Relationship

    National Research Council Canada - National Science Library

    Lu, Yadong; Wong, S. C; Zhang, Mengping; Shu, Chi-Wang

    2007-01-01

    ... initial condition and piecewise constant boundary conditions. The existence and uniqueness of entropy solutions for such conservation laws with discontinuous fluxes are not known mathematically...

  5. Evaluating the relationships between solar-induced chlorophyll fluorescence from Orbiting Carbon Observatory-2 and gross primary productivity from eddy covariance flux towers

    Science.gov (United States)

    Li, X.; Xiao, J.; He, B.

    2017-12-01

    Solar-induced chlorophyll fluorescence (SIF) opens a new perspective on the monitoring of vegetation photosynthesis from space, and has been recently used to estimate gross primary productivity (GPP). However, previous studies on SIF were mainly based on satellite observations from the Greenhouse Gases Observing Satellite (GOSAT) and Global Ozone Monitoring Experiment-2 (GOME-2), and the evaluation of these coarse-resolution SIF measurements using GPP derived from eddy covariance (EC) flux towers has been hindered by the scale mismatch between satellite and tower footprints. We use new far-red SIF observations from the Orbiting Carbon Observatory-2 (OCO-2) satellite with much finer spatial resolution and GPP data from EC flux towers from 2014 to 2016 to examine the relationship between GPP and SIF for temperate forests. The OCO-2 SIF tracked tower GPP fairly well, and had strong correlation with tower GPP at both retrieval bands (757nm and 771nm) and both instantaneous (mid-day) and daily timescales. Daily SIF at 757nm (SIF757) exhibited much stronger correlation with tower GPP compared to MODIS enhanced vegetation index (EVI) and normalized difference vegetation index (NDVI) derived from either Terra or Aqua and had a similarly strong relationship as EVI based on the bidirectional reflectance distribution function (BRDF) corrected reflectance product (Terra+Aqua). Absorbed photosynthetically active radiation (APAR) explained 85% of the variance in SIF757, while the product of APAR and two environmental scalars - fTmin and fVPD (representing minimum temperature stress and water stress) explained slightly higher variance (92%) in SIF757. This suggests that SIF mainly depends on APAR and also contains information on light use efficiency (LUE) reflecting environmental stresses and physiological or biochemical variations of vegetation. The hyperbolic model based on SIF757 estimated GPP well (R2=0.81, pforests and its potential in future ecosystem functioning and carbon

  6. Relationship Between Bone Minerals Density and Some Characteristics of Postmenopausal Women who Were Visiting Orthopedics Clinics - Original Investigation

    Directory of Open Access Journals (Sweden)

    Gülendam Karadağ

    2007-12-01

    Full Text Available Aim: Frequency of osteoporosis that depending different factors in postmenopausal women is increase. So our study was done to determine the relationship between some habits of the postmenopausal women and bone mineral density. Material and Methods: The study was done as descriptive a hospital in Gaziantep between the dates 3 July - 8 August, 2006. The comprehension of the study is all patients who applied to orthopedics clinics, and sampling consists of 70 patients who wanted to join study, and postmenopausal, hadn’t taken steroid and calcitonin treatment more than last one year. Before study, informed approwal was taken from patients and institution. Data of the study were collected using questionnaire form. Density of bone minerals was grouped according to the standarts of WHO as normal (t>-1.0, osteopenic (t0.05. Conclusion: It was seen that majority of patients didn’t make sports regularly, and the risk of having osteoporosis was higher who were getting older. For this reason, it can be suggested that to prevent osteoporosis especially in postmenopausal women necessary education should be given. (From the World of Osteoporosis 2007;13:75-9

  7. Experimental validation of plastic constitutive hardening relationship based upon the direction of the Net Burgers Density Vector

    Science.gov (United States)

    Sarac, Abdulhamit; Kysar, Jeffrey W.

    2018-02-01

    We present a new methodology for experimental validation of single crystal plasticity constitutive relationships based upon spatially resolved measurements of the direction of the Net Burgers Density Vector, which we refer to as the β-field. The β-variable contains information about the active slip systems as well as the ratios of the Geometrically Necessary Dislocation (GND) densities on the active slip systems. We demonstrate the methodology by comparing single crystal plasticity finite element simulations of plane strain wedge indentations into face-centered cubic nickel to detailed experimental measurements of the β-field. We employ the classical Peirce-Asaro-Needleman (PAN) hardening model in this study due to the straightforward physical interpretation of its constitutive parameters that include latent hardening ratio, initial hardening modulus and the saturation stress. The saturation stress and the initial hardening modulus have relatively large influence on the β-variable compared to the latent hardening ratio. A change in the initial hardening modulus leads to a shift in the boundaries of plastic slip sectors with the plastically deforming region. As the saturation strength varies, both the magnitude of the β-variable and the boundaries of the plastic slip sectors change. We thus demonstrate that the β-variable is sensitive to changes in the constitutive parameters making the variable suitable for validation purposes. We identify a set of constitutive parameters that are consistent with the β-field obtained from the experiment.

  8. Changes in tumor oxygen tension during radiotherapy of uterine cervical cancer: relationships to changes in vascular density, cell density, and frequency of mitosis and apoptosis

    International Nuclear Information System (INIS)

    Lyng, Heidi; Sundfoer, Kolbein; Rofstad, Einar K.

    2000-01-01

    Purpose: Changes in oxygen tension (pO 2 ) during the early phase of fractionated radiotherapy were studied in 22 patients with uterine cervical cancer. The aims were to investigate (a) whether possible changes in pO 2 differed among and within tumors and (b) whether the changes could be attributed to changes in vascular density, cell density, and frequency of mitosis and apoptosis. Methods and Materials: The pO 2 was measured polarographically in four regions of the tumors before treatment and after 2 weeks of radiotherapy. The vascular density, cell density, and frequency of mitosis and apoptosis were determined from biopsies taken from the tumor regions after each pO 2 measurement. Results: The changes in pO 2 during therapy differed among the tumors and were correlated to pO 2 before treatment (p 2 and vice versa. The tumors with increased pO 2 (n = 10) had a large decrease in cell density and a significant increase in apoptotic frequency. In contrast, the tumors with decreased pO 2 (n = 10) had a smaller decrease in cell density (p = 0.014) and no significant increase in apoptotic frequency. Vascular density and mitotic frequency showed no change during therapy; however, vascular damage other than decreased vascular density was observed. Conclusion: These results indicate that the oxygenation of cervix tumors generally changes during the early phase of radiotherapy. The change depends on the balance between the factor leading to an increase and that leading to a decrease in oxygenation; i.e., decreased cell density and vascular damage, respectively. Increased apoptotic frequency may contribute to a large decrease in cell density and hence increased oxygenation during therapy

  9. Relationship between intima-media thickness and bone mineral density in postmenopausal women: a cross-sectional study.

    Science.gov (United States)

    Mohammadi, Afshin; Shateri, Kamran; Behzadi, Farhad; Maleki-Miandoab, Tooraj; Lesha, Emal; Ghasemi-Rad, Mohammad; Rosta, Yousef

    2014-01-01

    Osteoporosis and atherosclerosis are two conditions that confer the major cause of mortality and morbidity in postmenopausal women. Several studies have suggested that these two conditions are negatively correlated by a common pathway. The aim of our study was to show a relationship between bone mineral density (BMD) and carotid intima media thickness (CIMT), as two factors that are directly related to osteoporosis and atherosclerosis respectively. The study group consisted of 136 postmenopausal women that presented at the Radiology Clinic of our hospital for BMD measurements. The CIMT was measured using High Resolution B mode Ultrasonography; BMD was measured at the lumbar spine and femoral neck using Dual-energy X-Ray Absorptiometry. The mean IMT value in osteoporotic women (0.7±0.1 mm) was significantly higher compared to non-osteoporotic women (0.6±0.1 mm, P media thickness are negatively correlated, thus showing a possible relationship between osteoporosis and atherosclerosis. However, more research is necessary to determine the pathway that connects these two conditions.

  10. Intraspecific relationships among wood density, leaf structural traits and environment in four co-occurring species of Nothofagus in New Zealand.

    Directory of Open Access Journals (Sweden)

    Sarah J Richardson

    Full Text Available Plant functional traits capture important variation in plant strategy and function. Recent literature has revealed that within-species variation in traits is greater than previously supposed. However, we still have a poor understanding of how intraspecific variation is coordinated among different traits, and how it is driven by environment. We quantified intraspecific variation in wood density and five leaf traits underpinning the leaf economics spectrum (leaf dry matter content, leaf mass per unit area, size, thickness and density within and among four widespread Nothofagus tree species in southern New Zealand. We tested whether intraspecific relationships between wood density and leaf traits followed widely reported interspecific relationships, and whether variation in these traits was coordinated through shared responses to environmental factors. Sample sites varied widely in environmental variables, including soil fertility (25-900 mg kg(-1 total P, precipitation (668-4875 mm yr(-1, temperature (5.2-12.4 °C mean annual temperature and latitude (41-46 °S. Leaf traits were strongly correlated with one another within species, but not with wood density. There was some evidence for a positive relationship between wood density and leaf tissue density and dry matter content, but no evidence that leaf mass or leaf size were correlated with wood density; this highlights that leaf mass per unit area cannot be used as a surrogate for component leaf traits such as tissue density. Trait variation was predicted by environmental factors, but not consistently among different traits; e.g., only leaf thickness and leaf density responded to the same environmental cues as wood density. We conclude that although intraspecific variation in wood density and leaf traits is strongly driven by environmental factors, these responses are not strongly coordinated among functional traits even across co-occurring, closely-related plant species.

  11. Relationship between bone mineral density and immune inflammatory parameters in women with osteoporosis concurrent with coronary heart diseases

    Directory of Open Access Journals (Sweden)

    S. Yu. Tsarenok

    2014-01-01

    Full Text Available Low bone mineral density (BMD is a risk factor of osteoporotic fractures. The RANKL–RANK–OPG system and some cytokines are known to play a role in the regulation of bone remodeling. Cytokines and osteoprotegerin (OPG are able to affect the cardiovascular system. It is highly relevant to study the relationship between BMD and cytokine levels in patients with a concurrence of osteoporosis (OP and coronary atherosclerosis.Objective: to estimate the relationship between BMD and the level of cytokines and OPG in women having OP comorbid with coronary heart disease (CHD.Subjects and methods. Sixty women (mean age 68.7±8.8 years with OP comorbid with CHD (Group 1 were examined; a control group consisted of 38 patients (mean age 69.4±8.1 years with isolated CHD (Group 2. BMD was measured in two regions: lumbar vertebrae (LI–IV and proximal femur, by employing a DEXA densitometer (CHALLENGER, France. The serum levels of OPG, interleukin (IL 1β, 4, 6, 8, 10, and tumor necrosis factor (TNF α were determined by enzyme-linked immunosorbent assay (ELISA.Results. The women with comorbidity were observed to have elevated IL6, 8, TNF-α, IL4, 10, and OPG levels. There was a negative correlation between IL1, TNF-α, and IL8 levels and vertebral BMD; OPG, IL4, 6, 8, and TNF-α concentrations were inversely related to femoral neck BMD. The independent factor of lower BMD was IL6 in the femoral neck and IL1 in the lumbar vertebrae. The findings suggest that there is a relationship between elevated cytokine levels and lower BMD in women having OP comorbid with CHD.

  12. Relationship between anode material, supporting electrolyte and current density during electrochemical degradation of organic compounds in water

    Energy Technology Data Exchange (ETDEWEB)

    Guzmán-Duque, Fernando L. [Grupo de diagnóstico y control de la contaminación, Facultad de ingeniería, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Palma-Goyes, Ricardo E. [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquía Udea, A.A. 1226, Medellín (Colombia); González, Ignacio [Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Química, Av. San Rafael Atlixco No 186, C.P 09340, México D.F (Mexico); Peñuela, Gustavo [Grupo de diagnóstico y control de la contaminación, Facultad de ingeniería, Universidad de Antioquia, A.A. 1226, Medellín (Colombia); Torres-Palma, Ricardo A., E-mail: rtorres@matematicas.udea.edu.co [Grupo de Investigación en Remediación Ambiental y Biocatálisis, Instituto de Química, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquía Udea, A.A. 1226, Medellín (Colombia)

    2014-08-15

    Highlights: • Pathway and efficiency are linked to the current-electrode–electrolyte interaction. • Unlike BDD, IrO{sub 2} route was independent of current but dependent on the electrolyte. • IrO{sub 2}/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} routes were via IrO{sub 3} and chlorine species, respectively. • BDD/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} systems were favored at low and high currents, respectively. - Abstract: Taking crystal violet (CV) dye as pollutant model, the electrode, electrolyte and current density (i) relationship for electro-degrading organic molecules is discussed. Boron-doped diamond (BDD) or Iridium dioxide (IrO{sub 2}) used as anode materials were tested with Na{sub 2}SO{sub 4} or NaCl as electrolytes. CV degradation and generated oxidants showed that degradation pathways and efficiency are strongly linked to the current density-electrode–electrolyte interaction. With BDD, the degradation pathway depends on i: If i < the limiting current density (i{sub lim}), CV is mainly degraded by ·OH radicals, whereas if i > i{sub lim}, generated oxidants play a major role in the CV elimination. When IrO{sub 2} was used, CV removal was not dependent on i, but on the electrolyte. Pollutant degradation in Na{sub 2}SO{sub 4} on IrO{sub 2} seems to occur via IrO{sub 3}; however, in the presence of NaCl, degradation was dependent on the chlorinated oxidative species generated. In terms of efficiency, the Na{sub 2}SO{sub 4} electrolyte showed better results than NaCl when BDD anodes were employed. On the contrary, NaCl was superior when combined with IrO{sub 2}. Thus, the IrO{sub 2}/Cl{sup −} and BDD/SO{sub 4}{sup 2−} systems were better at removing the pollutant, being the former the most effective. On the other hand, pollutant degradation with the BDD/SO{sub 4}{sup 2−} and IrO{sub 2}/Cl{sup −} systems is favored at low and high current densities, respectively.

  13. Analysis of the relationships between edentulism, periodontal health, body composition, and bone mineral density in elderly women

    Directory of Open Access Journals (Sweden)

    Ignasiak Z

    2016-03-01

    Full Text Available Zofia Ignasiak,1 Malgorzata Radwan-Oczko,2 Krystyna Rozek-Piechura,3 Marta Cholewa,4 Anna Skrzek,5 Tomasz Ignasiak,6 Teresa Slawinska1 1Department of Biostructure, University School of Physical Education, Wroclaw, Poland; 2Department of Periodontology, Wroclaw Medical University, Wroclaw, Poland; 3Department of Physiotherapy and Occupation Therapy in Internal Diseases, University School of Physical Education, Wroclaw, Poland; 4DENTARAMA Dentistry Center, Walbrzych, Poland; 5Department of Physiotherapy and Ocupation Therapy in Motor-System Dysfunction, University School of Physical Education, Wroclaw, Poland; 6Karkonosze State Higher School in Jelenia Gora, Jelenia Gora, Poland Objective: The relationship between bone mineral density (BMD and tooth loss in conjunction with periodontal disease is not clear. The suggested effects include alteration in bone remodeling rates as well as the multifaceted etiology of edentulism. There is also a question if other body-related variables besides BMD, such as body composition, may be associated with tooth number and general periodontal health. The aim of this study was to evaluate if tooth number and marginal periodontal status are associated with body composition and BMD in a sample of elderly women. Materials and methods: The study involved 91 postmenopausal women. Data included basic anthropometric characteristics, body composition via bioelectrical impedance analysis, and BMD analysis at the distal end of the radial bone of the nondominant arm via peripheral dual-energy X-ray absorptiometry. A dental examination was performed to assess tooth number, periodontal pocket depth (PD, and gingival bleeding. Results: In nonosteoporotic women, a significant positive correlation was found between BMD and lean body mass, total body water, and muscle mass. The indicators of bone metabolism correlated negatively with PD. Such relationships did not appear in osteoporotic women. In both groups, basic anthropometric

  14. Relationship between bone turnover and density with teriparatide, denosumab or both in women in the DATA study.

    Science.gov (United States)

    Tsai, J N; Burnett-Bowie, S M; Lee, H; Leder, B Z

    2017-02-01

    While changes in biochemical markers of bone turnover (BTM) have been reported to predict changes in bone mineral density (BMD), the relationship between changes in BMD and BTMs with combined antiresorptive/anabolic therapy is unknown. In the DATA study, 94 postmenopausal osteoporotic women (ages 51-91) received either teriparatide 20-mcg SC daily, denosumab 60-mg SC every 6months, or both for 2years. Pearson's correlation coefficients (R) were calculated to determine the relationship between baseline and early changes in BTMs (as well as serum sclerostin) and 2-year changes in BMD. In women receiving teriparatide, baseline BTMs did not correlate with 2-year BMD changes though 12-month increases in osteocalcin and P1NP were associated with 2-year increases in spine BMD. In women receiving denosumab, spine and hip BMD gains correlated with both baseline and changes in P1NP and C-telopeptide. In women receiving combined teriparatide/denosumab, while both baseline and decreases in P1NP were associated with spine BMD gains, distal radius increases were associated with less CTX suppression. Neither baseline nor changes in serum sclerostin correlated with BMD in any treatment group. In women treated with teriparatide or denosumab, early BTM changes (increases and decreases, respectively) predict 2-year BMD gains, especially at the spine. In women treated with combined teriparatide/denosumab therapy, BMD increases at the distal radius were associated with less suppression of bone turnover. These results suggest that efficacy of combination therapy at cortical sites such as the radius may depend on residual bone remodeling despite RANKL inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Neutron flux monitoring device

    International Nuclear Information System (INIS)

    Shimazu, Yoichiro.

    1995-01-01

    In a neutron flux monitoring device, there are disposed a neutron flux measuring means for outputting signals in accordance with the intensity of neutron fluxes, a calculation means for calculating a self power density spectrum at a frequency band suitable to an object to be measured based on the output of the neutron flux measuring means, an alarm set value generation means for outputting an alarm set value as a comparative reference, and an alarm judging means for comparing the alarm set value with the outputted value of the calculation means to judge requirement of generating an alarm and generate an alarm in accordance with the result of the judgement. Namely, the time-series of neutron flux signals is put to fourier transformation for a predetermined period of time by the calculation means, and from each of square sums for real number component and imaginary number component for each of the frequencies, a self power density spectrum in the frequency band suitable to the object to be measured is calculated. Then, when the set reference value is exceeded, an alarm is generated. This can reliably prevent generation of erroneous alarm due to neutron flux noises and can accurately generate an alarm at an appropriate time. (N.H.)

  16. The Relationship of Osteoporosis Risk Factors with Bone Mineral Density in Patients Admitted Our Outpatient Clinic in Trabzon

    Directory of Open Access Journals (Sweden)

    Münevver Serdaroğlu Beyazal

    2016-04-01

    Full Text Available Objective: Our aim was to identify the relationship of osteoporosis (OP risk factors with bone mineral density (BMD in patients admitted our outpatient clinic in Trabzon. Materials and Methods: Two hundred one patients with OP or osteopenia were included in this study. Sociodemographic characteristics of the patients were recorded and a standardized interview was employed by the researcher physician. BMD values were measured by dual energy X-ray absorptiometry at lumbar spine and femoral neck. Results: The mean age of the patients was 61.47±10.57 years (182 females/19 males. One hundred fifteen patients (57.2% were osteoporotic and 86 (42.8% were osteopenic. A significant negative correlation was found between age and femoral neck T scores. The number of pregnancies showed a significant negative correlation with lumbar T scores. Body mass index and daily tea consumption showed a negligible positive correlation with femoral neck T scores. No association was found between age at menarche, age at menopause, total lactation duration, daily calcium intake and T scores of lumbar spine and femoral neck. Conclusions: Identification of regional OP risk factors may be useful for the OP risk management of patients in clinical practice.

  17. Relationship between body mass index, bone mineral density, and oral hygiene with periodontal disease in a Mexican elderly group.

    Directory of Open Access Journals (Sweden)

    José Francisco Murrieta

    2016-05-01

    Full Text Available The aim of this study was to evaluate the relationship of body mass index (BMI, bone mineral density (BMD, and oral hygiene with periodontal disease (PD in a group of elderly adults in Mexico City. Material and Methods: A cross-sectional study with a convenience sample of 151 elderly adults was conducted. Before applying the epidemiological survey, each subject was asked to sign an informed consent. Standardization for measuring Ramfjord’s Periodontal Disease Index (PDI, BMI, and Green and Vermilion’s OHI-S was carried out. Descriptive statistics and linear regression models were performed. Results: The 93.4% of the group had PD, 33.8% showed severe gingivitis and 20.5% mild gingivitis. A 28.5% five percent of the group had osteopenia and 18.5% had osteoporosis, being more common in people over 69 years. The 38.4% percent of the group was underweight and 53.0% had poor oral hygiene. Oral hygiene accounted for 63.1% of the PD variance (p=0.0001, figure that did not increase considerably by adding BMD and BMI variables to the regression model. Conclusion: The frequency of PD in this group of elderly adults was high and significantly associated with BMD, BMI, and mainly oral hygiene.

  18. The relationship of total body composition with bone mineral density in postmenopausal women with type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Vadim Valer'evich Klimontov

    2015-03-01

    Full Text Available AimTo determine the relationship between bone mineral density (BMD and total body composition in postmenopausal women with type 2 diabetes.Materials and MethodsThe study included 78 women, from 50 to 70 years of age (median 63 years. Twenty women had normal body mass index (BMI, 29 ones were overweight and 29 had obesity. The body composition and BMD was studied by dual-energy X-ray absorptiometry.ResultsWomen with normal BMD had higher BMI, total and truncal fat mass, as well lean mass as compared to women with osteoporosis and osteopenia (all p <0.05. Patients with osteoporosis had a lower fat mass at the hips, compared with those with normal BMD. Total and truncal fat mass, as well as lean mass were positively correlated with BMD in the lumbar spine and proximal femur, femoral neck and radius. In multivariate regression analysis fat mass was an independent predictor for total BMD, after adjusting for age, BMI, duration of menopause, HbA1c, glomerular filtration rate and other total body composition parameters.ConclusionsIn postmenopausal type 2 diabetic women BMI and fat mass is associated positively with BMD.

  19. Relationship of total body fat mass to weight-bearing bone volumetric density, geometry, and strength in young girls.

    Science.gov (United States)

    Farr, Joshua N; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

    2010-04-01

    Understanding the influence of total body fat mass (TBFM) on bone during the peri-pubertal years is critical for the development of future interventions aimed at improving bone strength and reducing fracture risk. Thus, we evaluated the relationship of TBFM to volumetric bone mineral density (vBMD), geometry, and strength at metaphyseal and diaphyseal sites of the femur and tibia of young girls. Data from 396 girls aged 8-13 years from the "Jump-In: Building Better Bones" study were analyzed. Bone parameters were assessed using peripheral quantitative computed tomography (pQCT) at the 4% and 20% distal femur and 4% and 66% distal tibia of the non-dominant leg. Bone parameters at the 4% sites included trabecular vBMD, periosteal circumference, and bone strength index (BSI), while at the 20% femur and 66% tibia, parameters included cortical vBMD, periosteal circumference, and strength-strain index (SSI). Multiple linear regression analyses were used to assess associations between bone parameters and TBFM, controlling for muscle cross-sectional area (MCSA). Regression analyses were then repeated with maturity, bone length, physical activity, and ethnicity as additional covariates. Analysis of covariance (ANCOVA) was used to compare bone parameters among tertiles of TBFM. In regression models with TBFM and MCSA, associations between TBFM and bone parameters at all sites were not significant. TBFM explained very little variance in all bone parameters (0.2-2.3%). In contrast, MCSA was strongly related (p<0.001) to all bone parameters, except cortical vBMD. The addition of maturity, bone length, physical activity, and ethnicity did not alter the relationship between TBFM and bone parameters. With bone parameters expressed relative to total body mass, ANCOVA showed that all outcomes were significantly (p<0.001) greater in the lowest compared to the middle and highest tertiles of TBFM. Although TBFM is correlated with femur and tibia vBMD, periosteal circumference, and

  20. Effect of planting density on root lodging resistance and its relationship to nodal root growth characteristics in maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Liu, Shengqun; Song, Fengbin; Liu, Fulai

    2012-01-01

    Increase of planting density has been widely used to increase grain yield in maize. However, it may lead to higher risk of root lodging hence causing significant yield loss of the crop. The objective of this study was to investigate the effect of planting density on maize nodal root growth...... characteristics and to analyse their relationships to root lodging resistance. Field experiment was conducted in 2010 and 2011, using two maize varieties, Zhengdan 958 (ZD) and Xianyu 335 (XY), under three planting densities, viz., 4.50, 8.25 and 12.00 plants m-2. The results showed the root failure moment......, an indicator of root lodging resistance, was significantly affected by the planting density, the maize variety, as well as the crop developmental stages, and was decreased with increasing planting density. The number and the average diameter of the roots on the upper internodes (phytomer 5 to 8) were decreased...

  1. Relationships among wood anatomy, hydraulic conductivity, density and shear parallel to the grain in the wood of 24-year-old Handroanthus vellosoi (Bignoniaceae)

    OpenAIRE

    Longui, Eduardo Luiz; Oliveira, Ivanka Rosada de; Graebner, Ryan Combs; Freitas, Miguel Luiz Menezes; Florsheim, Sandra Monteiro Borges; Garcia, José Nivaldo

    2017-01-01

    Abstract We studied the relationships among wood anatomy, hydraulic conductivity, density and shear parallel to the grain in the stem of Handroanthus vellosoi trees with the goal to identify possible trade-offs between hydraulic conductivity and mechanical properties. For this study we felled 12 trees with 24-year-old and cut 10-cm-thick disks at three heights: base of the trunk, one meter in height, and two meters in height. We propose that the relationship between hydraulic conductivity and...

  2. Influence of heat and particle fluxes nonlocality on spatial distribution of plasma density in two-chamber inductively coupled plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Kudryavtsev, A. A.; Serditov, K. Yu. [Faculty of Physics, St. Petersburg State University, 198504 St. Petersburg (Russian Federation)

    2012-07-15

    This study presents 2D simulations of the two-chamber inductively coupled plasma source where power is supplied in the small discharge chamber and extends by electron thermal conductivity mechanism to the big diffusion chamber. Depending on pressure, two main scenarios of plasma density and its spatial distribution behavior were identified. One case is characterized by the localization of plasma in the small driver chamber where power is deposed. Another case describes when the diffusion chamber becomes the main source of plasma with maximum of the electron density. The differences in spatial distribution are caused by local or non-local behavior of electron energy transport in the discharge volume due to different characteristic scale of heat transfer with electronic conductivity.

  3. Conical electromagnetic radiation flux concentrator

    Science.gov (United States)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  4. The hole spectral function and the relationship between overlap functions, natural orbitals and the one-body density matrix in nuclei

    International Nuclear Information System (INIS)

    Antonov, A.N.; Stoitsov, M.V.; Gaidarov, M.K.; Dimitrova, S.S.; Hodgson, P.E.

    1995-01-01

    A method to calculate the hole spectral function in the discrete part of the spectrum is suggested within the natural orbital representation of the one-body density matrix of the A-nucleon system using its relationship with the overlap functions of the eigenstates in the (A-1)-nucleon system. (author)

  5. The relationship between the bone mineral density and urinary cadmium concentration of residents in an industrial complex

    International Nuclear Information System (INIS)

    Shin, Minah; Paek, Domyung; Yoon, Chungsik

    2011-01-01

    Background: An association between cadmium exposure and bone mineral density (BMD) has been demonstrated in elderly women, but has not been well studied in youths and men. Some studies report either no or a weak association between cadmium exposure and bone damage. Objectives: This study was designed to investigate the relationship between the urinary cadmium (U-Cd) levels and BMD of females and males of all ages. Methods: A total of 804 residents near an industrial complex were surveyed in 2007. U-Cd and BMD on the heel (non-dominant calcaneus) were analyzed with AAS-GTA and Dual-Energy X-ray absorptiometry, respectively. Demographic characteristics were collected by structured questionnaires. Osteoporosis and osteopenia were defined by BMD cut-off values and T-scores set by the WHO; T score>-1, normal; -2.5< T score <-1, osteopenia; and T score <-2.5, osteoporosis. Logistic and multiple linear regressions were applied to estimate the association between U-Cd levels and BMD. Results: The U-Cd levels in females (0.64 μg/g creatinine) were higher than those in males (0.48 μg/g creatinine) (p<0.001). With the logistic regression model, osteopenia was associated with high U-Cd levels (≥1.0 μg/g creatinine) in females (OR=2.92; 95% CI, 1.51-5.64) and in males (OR=3.37; 95% CI, 1.09-10.38). With the multiple linear regression model, the BMD of the adult group was negatively associated with U-Cd (<0.05), gender (female, p<0.001) and age (p<0.001). The BMD of participants who were ≤19 years of age was negatively associated with gender (female, p<0.01), whereas it was positively associated with age and BMI (p<0.001). BMD was not associated with exercise, smoking habits, alcohol consumption, job or parental education. Conclusion: Results suggested that U-Cd might be associated with osteopenia as well as osteoporosis in both male and female adults. Age and female gender were negatively associated with BMD in the adult group, whereas age was positively associated with

  6. "Single nucleotide polymorphisms of the OPG/RANKL system genes in primary hyperparathyroidism and their relationship with bone mineral density"

    Directory of Open Access Journals (Sweden)

    Piedra María

    2011-12-01

    Full Text Available Abstract Background Primary hyperparathyroidism (PHPT affects mainly cortical bone. It is thought that parathyroid hormone (PTH indirectly regulates the activity of osteoclasts by means of the osteoprotegerin/ligand of the receptor activator of nuclear factor-κβ (OPG/RANKL system. Several studies have confirmed that OPG (osteoprotegerin and RANKL (ligand of the receptor activator of nuclear factor-κβ loci are determinants of bone mineral density (BMD in the general population. The aim of this study is to analyze the relationship between fractures and BMD and the rs3102735 (163 A/G, rs3134070 (245 T/G and rs2073618 (1181 G/C SNPs of the OPG and the rs2277438 SNP of the RANKL, in patients with sporadic PHPT. Methods We enrolled 298 Caucasian patients with PHPT and 328 healthy volunteers in a cross-sectional study. We analyzed anthropometric data, history of fractures or renal lithiasis, biochemical determinants including markers for bone remodelling, BMD measurements in the lumbar spine, total hip, femoral neck and distal radius, and genotyping for the SNPs to be studied. Results Regarding the age of diagnosis, BMI, menopause status, frequency of fractures or renal lithiasis, we found no differences between genotypes in any of the SNPs studied in the PHPT group. Significant lower BMD in the distal radius with similar PTH levels was found in the minor allele homozygotes (GG compared to heterozygotes and major allele homozygotes in both OPG rs3102735 (163 A/G and OPG rs3134070 (245 T/G SNPs in those with PHPT compared to control subjects. We found no differences between genotypes of the OPG rs2073618 (1181 G/C SNP with regard to BMD in the PHPT subjects. In the evaluation of rs2277438 SNP of the RANKL in PHPT patients, we found a non significant trend towards lower BMD in the 1/3 distal radius and at total hip in the minor allele homocygotes (GG genotype group versus heterocygotes and major allele homocygotes (AA. Conclusions Our study provides

  7. "Single nucleotide polymorphisms of the OPG/RANKL system genes in primary hyperparathyroidism and their relationship with bone mineral density"

    Science.gov (United States)

    2011-01-01

    Background Primary hyperparathyroidism (PHPT) affects mainly cortical bone. It is thought that parathyroid hormone (PTH) indirectly regulates the activity of osteoclasts by means of the osteoprotegerin/ligand of the receptor activator of nuclear factor-κβ (OPG/RANKL) system. Several studies have confirmed that OPG (osteoprotegerin) and RANKL (ligand of the receptor activator of nuclear factor-κβ) loci are determinants of bone mineral density (BMD) in the general population. The aim of this study is to analyze the relationship between fractures and BMD and the rs3102735 (163 A/G), rs3134070 (245 T/G) and rs2073618 (1181 G/C) SNPs of the OPG and the rs2277438 SNP of the RANKL, in patients with sporadic PHPT. Methods We enrolled 298 Caucasian patients with PHPT and 328 healthy volunteers in a cross-sectional study. We analyzed anthropometric data, history of fractures or renal lithiasis, biochemical determinants including markers for bone remodelling, BMD measurements in the lumbar spine, total hip, femoral neck and distal radius, and genotyping for the SNPs to be studied. Results Regarding the age of diagnosis, BMI, menopause status, frequency of fractures or renal lithiasis, we found no differences between genotypes in any of the SNPs studied in the PHPT group. Significant lower BMD in the distal radius with similar PTH levels was found in the minor allele homozygotes (GG) compared to heterozygotes and major allele homozygotes in both OPG rs3102735 (163 A/G) and OPG rs3134070 (245 T/G) SNPs in those with PHPT compared to control subjects. We found no differences between genotypes of the OPG rs2073618 (1181 G/C) SNP with regard to BMD in the PHPT subjects. In the evaluation of rs2277438 SNP of the RANKL in PHPT patients, we found a non significant trend towards lower BMD in the 1/3 distal radius and at total hip in the minor allele homocygotes (GG) genotype group versus heterocygotes and major allele homocygotes (AA). Conclusions Our study provides the first

  8. The relationship between the bone mineral density and urinary cadmium concentration of residents in an industrial complex

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Minah; Paek, Domyung [Institute of Health and Environment, Department of Environmental Health, School of Public Health, Seoul National University, Gwanak-599, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Yoon, Chungsik, E-mail: csyoon@snu.ac.kr [Institute of Health and Environment, Department of Environmental Health, School of Public Health, Seoul National University, Gwanak-599, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

    2011-01-15

    Background: An association between cadmium exposure and bone mineral density (BMD) has been demonstrated in elderly women, but has not been well studied in youths and men. Some studies report either no or a weak association between cadmium exposure and bone damage. Objectives: This study was designed to investigate the relationship between the urinary cadmium (U-Cd) levels and BMD of females and males of all ages. Methods: A total of 804 residents near an industrial complex were surveyed in 2007. U-Cd and BMD on the heel (non-dominant calcaneus) were analyzed with AAS-GTA and Dual-Energy X-ray absorptiometry, respectively. Demographic characteristics were collected by structured questionnaires. Osteoporosis and osteopenia were defined by BMD cut-off values and T-scores set by the WHO; T score>-1, normal; -2.5=}1.0 {mu}g/g creatinine) in females (OR=2.92; 95% CI, 1.51-5.64) and in males (OR=3.37; 95% CI, 1.09-10.38). With the multiple linear regression model, the BMD of the adult group was negatively associated with U-Cd (<0.05), gender (female, p<0.001) and age (p<0.001). The BMD of participants who were {<=}19 years of age was negatively associated with gender (female, p<0.01), whereas it was positively associated with age and BMI (p<0.001). BMD was not associated with exercise, smoking habits, alcohol consumption, job or parental education. Conclusion: Results suggested that U-Cd might be associated with osteopenia as well as osteoporosis in both male and female adults. Age and female gender were negatively associated with BMD in the adult group, whereas age was positively

  9. Co-current Doping Effect of Nanoscale Carbon and Aluminum Nitride on Critical Current Density and Flux Pinning Properties of Bulk MgB2 Superconductors

    Science.gov (United States)

    Tripathi, D.; Dey, T. K.

    2018-01-01

    The effect of nanoscale aluminum nitride (n-AlN) and carbon (n-C) co-doping on superconducting properties of polycrystalline bulk MgB2 superconductor has been investigated. Polycrystalline pellets of MgB2 , MgB2 + 0.5 wt% AlN (nano), MgB_{1.99}C_{0.01} and MgB_{1.99}C_{0.01} + 0.5 wt% AlN (nano) have been synthesized by a solid reaction process under inert atmosphere. The transition temperature (TC) estimated from resistivity measurement indicates only a small decrease for C (nano) and co-doped MgB2 samples. The magnetic field response of investigated samples has been measured at 4, 10, and 20 K in the field range ± 6 T. MgB2 pellets co-doped with 0.5 wt% n-AlN and 1 wt% n-C display appreciable enhancement in critical current density (J_C ) of MgB2 in both low (≥ 3 times), as well as, high-field region (≥ 15 times). J_C versus H behavior of both pristine and doped MgB2 pellets is well explained in the light of the collective pinning model. Further, the normalized pinning force density f_p(= F_p/F_{pmax}) displays a fair correspondence with the scaling procedure proposed by Eisterer et al. Moreover, the scaled data of the pinning force density (i.e., f_p{-}h data) of the investigated pellets at different temperature are well interpreted by a modified Dew-Hughes expression reported by Sandu and Chee.

  10. From Structural Complexity to Structure-Property Relationships in Intermetallics: Development of Density Functional Theory-Chemical Pressure Analysis

    Science.gov (United States)

    Engelkemier, Joshua

    away from each other (negative CP). This technique is used in combination with the concept of structural plasticity (Berns, 2014) to demonstrate how complex intermetallic phases can be understood as a response of simpler structure types to the destabilizing buildup of CP. From this point of view, interfaces created in complex structures relieve the CP manifest in the more basic, parent structures. This is shown specifically for Ca36Sn23 relative to a hypothetical W5Si3-type Ca5Sn3 phase, LnMn xGa3 (Ln = Ho-Tm, x < 0.15) compared to unstuffed AuCu3-type LnGa3 structures, and structural derivatives of CaCu5- and HoCoGa5-type compounds. As a direct result of the technical developments necessitated by these analyses on structural complexity in intermetallics, a further connection is made in this thesis between the calculated CP schemes and the frequencies of vibrational modes in MgCu2-type CaPd2, the Cr 3Si-type superconductor Nb3Ge, and CaCu5-type CaPd5. Local chemical interactions revealed by DFT-CP analysis are used to identify structure-property relationships for the pseudogap in the phonon density of states (DOS) of CaPd2, the higher critical temperature of Nb3Ge vs. Nb3Sn, and the wide diversity of structures based on the CaCu5 type.

  11. Relationship between Body Mass Composition, Bone Mineral Density, Skin Fibrosis and 25(OH Vitamin D Serum Levels in Systemic Sclerosis.

    Directory of Open Access Journals (Sweden)

    Addolorata Corrado

    Full Text Available A reduced bone mineral density (BMD is observed in several rheumatic autoimmune diseases, including Systemic Sclerosis (SSc; nevertheless, data concerning the possible determinants of bone loss in this disease are not fully investigated. The aim of this study is to evaluate the relationship between BMD, body mass composition, skin sclerosis and serum Vitamin D levels in two subsets of SSc patients. 64 post-menopausal SSc patients, classified as limited cutaneous (lcSSc or diffuse cutaneous (dcSSc SSc, were studied. As control, 35 healthy post-menopausal women were recruited. Clinical parameters were evaluated, including the extent of skin involvement. BMD at lumbar spine, hip, femoral neck and body mass composition were determined by dual-energy X-ray absorptiometry. Serum calcium, phosphorus, alkaline phosphatase, urine pyridinium cross-links, intact parathyroid hormone and 25-hydroxyvitamin D (25OHD were measured. BMD at spine, femoral neck and total hip was significantly lower in SSc patients compared to controls. In dcSSc subset, BMD at spine, femoral neck and total hip was significantly lower compared to lcSSc. No differences in both fat and lean mass were found in the three study groups even if patients with dcSSc showed a slightly lower total body mass compared to healthy controls. Total mineral content was significantly reduced in dSSc compared to both healthy subjects and lcSSc group. Hypovitaminosis D was observed both in healthy post-menopausal women and in SSc patients, but 25OHD levels were significantly lower in dcSSc compared to lcSSc and inversely correlated with the extent of skin thickness. These results support the hypothesis that the extent of skin involvement in SSc patients could be an important factor in determining low circulating levels of 25OHD, which in turn could play a significant role in the reduction of BMD and total mineral content.

  12. THE RELATIONSHIP BETWEEN FOVEAL AVASCULAR ZONE AREA, VESSEL DENSITY, AND CYSTOID CHANGES IN DIABETIC RETINOPATHY, AN OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY STUDY.

    Science.gov (United States)

    Tarassoly, Kia; Miraftabi, Arezoo; Soltan Sanjari, Mostafa; Parvaresh, Mohammad Mehdi

    2017-06-29

    To measure the foveal avascular zone (FAZ) areas and vessel densities of patients with diabetic retinopathy and to study their relationship with diabetic cystoid changes and retinal thickness. Prospective case series of 51 eyes of 31 patients with diabetic retinopathy. The eyes were grouped based on the presence or absence of cystoid edema and evaluated using optical coherence tomography angiography. The FAZ areas and vessel density were compared. The FAZ area at the superficial capillary plexus level was equal between the eyes with and without cystoid edema. Vessel density did not differ as well. There was no correlation with retinal thickness. In eyes with cystoid changes, FAZ area changes at the deep capillary plexus level were difficult to interpret. The FAZ area and vessel density at the superficial capillary plexus level are reproducible and independent of the presence of cystoid edema.

  13. Quantification of Macular Vascular Density Using Optical Coherence Tomography Angiography and Its Relationship with Retinal Thickness in Myopic Eyes of Young Adults

    Directory of Open Access Journals (Sweden)

    Shiqi Yang

    2017-01-01

    Full Text Available Purpose. To quantify macular vascular density using optical coherence tomography angiography (OCTA and to investigate its relationship with retinal thickness in myopic eyes of young adults. Methods. In this cross-sectional study, 268 myopic eyes without pathological changes were recruited and divided into three groups: mild myopia (n=81, moderate myopia (n=117, and high myopia (n=70. Macular vascular density was quantified by OCTA and compared among three groups. Average retinal thickness, central subfield thickness, and macular ganglion cell complex (mGCC thickness were also evaluated and compared. Correlations among these variables were analyzed. Results. There was no statistical difference in superficial (62.3 ± 5.7% versus 62.7 ± 5.9% versus 63.8 ± 5.5% and deep macular vascular densities (58.3 ± 9.6% versus 59.2 ± 9.3% versus 60.9 ± 7.9% among mild-myopia, moderate-myopia, and high-myopia groups (both P>0.05. Superficial and deep macular vascular densities both had correlations with mean arterial pressure. Furthermore, superficial macular vascular density was significantly correlated with mGCC thickness. Conclusions. Varying degrees of myopia did not affect macular vascular density in young healthy adults. In addition, superficial macular vascular density, as an independent factor, was positively correlated with mGCC thickness.

  14. Commissioning and modification of the low temperature scanning polarization microscope (TTSPM) and imaging of the local magnetic flux density distribution in superconducting niobium samples

    International Nuclear Information System (INIS)

    Gruenzweig, Matthias Sebastian Peter

    2014-01-01

    possible to image the magnetization reversal process and thus the formation (or destruction) and the migration of an ''Interfacial Domain Wall'' (IDW) in such a Fe 1-x Tb x / vertical stroke Co/Pt vertical stroke n -heterostructure. Part II of the dissertation is about the magneto-optical imaging of superconducting Niobium coplanar microwave resonators as well as of a Niobium single crystal. By means of the magneto-optical images of the resonators, important findings about magnetic hysteresis effects in such coplanar microwave resonators could be achieved. It was also possible to confirm the results of transmission spectroscopy experiments on those coplanar resonators, which were performed in a previous dissertation of Daniel Bothner. Additionally, it was possible to show that initially inserted Abrikosov vortices can be almost completely removed from the coplanar resonators again by properly cycling the magnetic field. On the basis of magneto-optical images of a 2 mm thick Niobium single crystal, it was possible to observe dendritic avalanches in a superconducting bulk material for the first time. Here, the dendritic avalanches only appear in a very narrow temperature interval of about a tenth of a Kelvin below the critical temperature T c of the Niobium single crystal. Below this threshold temperature the magnetic flux penetrates nearly homogeneously into the single crystal. The observed dendritic avalanches in the bulk single crystal near T c have features which are identical to those seen in thin films at low temperatures caused by thermomagnetic instability. Therefore, one can conclude that the dendritic avalanches in the single crystal are formed in a thin superconducting layer at the surface of the single crystal, which can be formed under certain conditions near T c .

  15. Breast Tissue Composition and Immunophenotype and Its Relationship with Mammographic Density in Women at High Risk of Breast Cancer.

    Directory of Open Access Journals (Sweden)

    Jia-Min B Pang

    Full Text Available To investigate the cellular and immunophenotypic basis of mammographic density in women at high risk of breast cancer.Mammograms and targeted breast biopsies were accrued from 24 women at high risk of breast cancer. Mammographic density was classified into Wolfe categories and ranked by increasing density. The histological composition and immunophenotypic profile were quantified from digitized haematoxylin and eosin-stained and immunohistochemically-stained (ERα, ERβ, PgR, HER2, Ki-67, and CD31 slides and correlated to mammographic density.Increasing mammographic density was significantly correlated with increased fibrous stroma proportion (rs (22 = 0.5226, p = 0.0088 and significantly inversely associated with adipose tissue proportion (rs (22 = -0.5409, p = 0.0064. Contrary to previous reports, stromal expression of ERα was common (19/20 cases, 95%. There was significantly higher stromal PgR expression in mammographically-dense breasts (p=0.026.The proportion of stroma and fat underlies mammographic density in women at high risk of breast cancer. Increased expression of PgR in the stroma of mammographically dense breasts and frequent and unexpected presence of stromal ERα expression raises the possibility that hormone receptor expression in breast stroma may have a role in mediating the effects of exogenous hormonal therapy on mammographic density.

  16. Being in a romantic relationship is associated with reduced gray matter density in striatum and increased subjective happiness

    OpenAIRE

    Hiroaki Kawamichi; Hiroaki Kawamichi; Hiroaki Kawamichi; Sho K Sugawara; Yuki H Hamano; Yuki H Hamano; Kai Makita; Masahiro Matsunaga; Hiroki C Tanabe; Yuichi Ogino; Shigeru Saito; Norihiro Sadato; Norihiro Sadato

    2016-01-01

    Romantic relationship, a widespread feature of human society, is one of the most influential factors in daily life. Although stimuli related to romantic love or being in a romantic relationship commonly result in enhancement of activation or functional connectivity of the reward system, including the striatum, the structure underlying romantic relationship-related regions remain unclear. Because individual experiences can alter gray matter within the adult human brain, we hypothesized that ro...

  17. Being in a Romantic Relationship Is Associated with Reduced Gray Matter Density in Striatum and Increased Subjective Happiness

    OpenAIRE

    Kawamichi, Hiroaki; Sugawara, Sho K.; Hamano, Yuki H.; Makita, Kai; Matsunaga, Masahiro; Tanabe, Hiroki C.; Ogino, Yuichi; Saito, Shigeru; Sadato, Norihiro

    2016-01-01

    Romantic relationship, a widespread feature of human society, is one of the most influential factors in daily life. Although stimuli related to romantic love or being in a romantic relationship commonly result in enhancement of activation or functional connectivity of the reward system, including the striatum, the structure underlying romantic relationship-related regions remain unclear. Because individual experiences can alter gray matter within the adult human brain, we hypothesized that ro...

  18. Relationships between bone mineral density and new indices of body composition in young, sedentary men and women

    Directory of Open Access Journals (Sweden)

    Anna Kęska

    2018-03-01

    The use of IFM and ILM in the present study, allowed the observation that in young adults lean body mass was associated with BMD, regardless of gender, while fat mass is significant for bone mineral density only in women

  19. Determination of semi-empirical relationship between the manganese and hydrogen atoms ratio, physical density and concentration in an aqueous solution of manganese sulphate

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Bittencourt, Guilherme, E-mail: bittencourt@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil); Souza Patrao, Karla Cristina de, E-mail: karla@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil); Passos Leite, Sandro, E-mail: sandro@ird.gov.b [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Wagner Pereira, Walsan, E-mail: walsan@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil); Simoes da Fonseca, Evaldo, E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil)

    2010-12-15

    The Manganese sulphate solution has been used for neutron metrology through the method of Manganese Bath. This method uses physical parameters of manganese sulphate solution to obtain its corrections. This work established a functional relationship, using the gravimetric method, between those physical parameters: density, concentration and hydrogen to manganese ratio. Comparisons were done between manganese sulphate solution concentration from the Manganese Bath system of Laboratory of Metrology of Ionising Radiation and estimated values from the functional relationship obtained, showing percentage difference of less than 0.1%. This result demonstrates the usefulness in the correlation of the physical values of the solution to the MB.

  20. Relationship between Exercise Style and Bone Mineral Density in Male High School Students : From a viewpoint of Exercise History and Competence

    OpenAIRE

    Luo, Ping

    2007-01-01

    The bone quality values (OSI) of 119 male high school students were evaluated by acoustic osteo screener. The questionnaire survey on the exercise experience and competence was made from the term of elementary to high school. The relationship between exercise experience and bone mineral density was researched.Result showed that the students who made regular exercise had higher OSI values than that who had not exercise customs. The values of OSI produced higher value within the participants wh...

  1. Interpreting Flux from Broadband Photometry

    Science.gov (United States)

    Brown, Peter J.; Breeveld, Alice; Roming, Peter W. A.; Siegel, Michael

    2016-10-01

    We discuss the transformation of observed photometry into flux for the creation of spectral energy distributions (SED) and the computation of bolometric luminosities. We do this in the context of supernova studies, particularly as observed with the Swift spacecraft, but the concepts and techniques should be applicable to many other types of sources and wavelength regimes. Traditional methods of converting observed magnitudes to flux densities are not very accurate when applied to UV photometry. Common methods for extinction and the integration of pseudo-bolometric fluxes can also lead to inaccurate results. The sources of inaccuracy, though, also apply to other wavelengths. Because of the complicated nature of translating broadband photometry into monochromatic flux densities, comparison between observed photometry and a spectroscopic model is best done by forward modeling the spectrum into the count rates or magnitudes of the observations. We recommend that integrated flux measurements be made using a spectrum or SED which is consistent with the multi-band photometry rather than converting individual photometric measurements to flux densities, linearly interpolating between the points, and integrating. We also highlight some specific areas where the UV flux can be mischaracterized.

  2. The relationship between postmenopausal women's sclerostin levels and their bone density, age, body mass index, hormonal status, and smoking and consumption of coffee and dairy products.

    Science.gov (United States)

    Kalem, Muberra Namlı; Kalem, Ziya; Akgun, Nilufer; Bakırarar, Batuhan

    2017-03-01

    To investigate the relationship between postmenopausal women's sclerostin levels and bone density and the factors that may affect this relationship. 135 postmenopausal patients' ages, BMIs, hormonal statuses, BMD values, and smoking, and consumption of coffee and dairy products were compared with their sclerostin levels. No statistical relationship was found between sclerostin level and age in the group with osteoporosis (p = 0.204, r = -0.305). There was a positive, high-level relationship between sclerostin levels and BMI in the osteoporosis group and it was found to be statistically significant (p relationship was found between sclerostin level and age in the non-osteoporosis group with (p = 0.496, r = -0.88). There was a positive, moderate relationship between sclerostin levels and BMI in the non-osteoporosis group and it was found to be statistically significant (p relationship could be found between sclerostin levels and vitamin D (p = 0.723), PTH (p = 0.112), FSH (p = 0.795), E 2 (p = 0.627), TSH (p = 0.517), T 3 (p = 0.788), and T 4 (p = 0.664) blood levels. No significant difference was found among the groups formed by smoking, consumption of coffee and milk, and dairy products, either (p = 0.405; p = 0.626; p = 0.234, respectively). It was monitored that sclerostin's negative effect observed on BMD scores was independent from age; however, it had a positive correlation with BMI. As blood sclerostin levels increase, bone mineral density decreases. This negative effect of sclerostin on bone density increases as BMI increases, too. Effects of sclerostin levels on bone density are independent from age, and they are not affect by levels of vitamin D: PTH, FSH, E 2 and thyroid hormones, and daily activities, such as smoking and consumption of coffee and milk and dairy products, either.

  3. RELATIONSHIPS BETWEEN ANATOMICAL FEATURES AND INTRA-RING WOOD DENSITY PROFILES IN Gmelina arborea APPLYING X-RAY DENSITOMETRY

    Directory of Open Access Journals (Sweden)

    Mario Tomazelo-Filho

    2007-12-01

    Full Text Available Four annual tree-rings (2 of juvenile wood and 2 of mature wood were sampled from fast-growth plantations ofGmelina arborea in two climatic conditions (dry and wet tropical in Costa Rica. Each annual tree-ring was divided in equal parts ina radial direction. For each part, X-ray density as well as vessel percentage, length and width fiber, cell wall thickness and lumendiameter were measured. Wood density and profile patterns of cell dimension demonstrated inconsistency between juvenile andmature wood and climatic conditions. The Pearson correlation matrix showed that intra-ring wood density was positively correlatedwith the cell wall thickness and negatively correlated with vessel percentage, fiber length, lumen diameter and width. The forwardstepwise regressions determined that: (i intra-ring wood density variation could be predicted from 76 to 96% for anatomicalvariation; (ii cell wall thickness was the most important anatomical feature to produce intra-ring wood density variation and (iii thevessel percentage, fiber length, lumen diameter and width were the second most statically significant characteristics to intra-ring wooddensity, however, with low participation of the determination coefficient of stepwise regressions.

  4. Water vapour fluxes trends on different time scales and their relationship with weather and soil drivers: a case study from a dehesa site in South Spain

    Science.gov (United States)

    Polo, María José; Egüen, Marta; Andreu, Ana; Carpintero, Elisabet; Gómez-Giráldez, Pedro; Patrocinio González-Dugo, María

    2017-04-01

    Water vapour fluxes between the soil surface and the atmosphere constitute one of the most important components of the water cycle in the continental areas. Their regime directly affect the availability of water to plants, water storage in surface bodies, air humidity in the boundary layer, snow persistence… among others, and the list of indirectly affected processes comprises a large number of components. Water potential or wetness gradients are some of the main drivers of water vapour fluxes to the atmosphere; soil humidity is usually monitored as key variable in many hydrological and environmental studies, and its estimated series are used to calibrate and validate the modelling of certain hydrological processes. However, such results may differ when water fluxes are used instead of water state variables, such as humidity. This work shows the analysis of high resolution water vapour fluxes series from a dehesa area in South Spain where a complete energy and water fluxes/variables monitoring site has been operating for the last four years. The results include pasture and tree vegetated control points. The daily water budget calculation on both types of sites has been performed from weather and energy fluxes measurements, and soil moisture measurements, and the results have been aggregated on a weekly, monthly and seasonal basis. Comparison between observed trends of soil moisture and calculated trends of water vapour fluxes is included to show the differences arising in terms of the regime of the dominant weather variables in this type of ecosystems. The results identify significant thresholds for each weather variable driver and highlight the importance of the wind regime, which is the somehow forgotten variable in future climate impacts on hydrology. Further work is being carried out to assess water cycle potential trends under future climate conditions and their impacts on the vegetation in dehesa ecosystems.

  5. Relationship of Physical Performance with Body Composition and Bone Mineral Density in Individuals over 60 Years of Age: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Hyehyung Shin

    2011-01-01

    Full Text Available The purpose of this review was to examine the relationship between physical performance and body composition measurements, including fat/muscle mass and bone mineral density (BMD in individuals ≥60 years of age. Various measurements used to assess body composition, BMD, and physical performance (PP were discussed as well. Medline/PubMed, CINAHL, and SCIE were used to identify articles. After limiting the search for age and kind of physical performance measures, 33 articles were evaluated. Higher fat mass was associated with poorer physical performance while higher muscle mass was a predictor of better physical performance, especially in the lower extremities. Additionally, evidence showed that higher muscle fat infiltration was a determinant of poorer physical performance. BMD was shown to be a good predictor of physical performance although the relationship was stronger in women than in men. Developing standardized methods for PP measurements could help in further investigation and conclusions of its relationship with body composition.

  6. Relationships among foliar phenology, radial growth rate, and xylem density in a young Douglas-fir plantation

    Science.gov (United States)

    Warren D. Devine; Constance A. Harrington

    2009-01-01

    We related intraannual patterns in radial growth rate and xylem density to foliar phenology and second growth flushes in a young Douglas-fir plantation in western Washington. Three foliar maturity classes were defined: (1) shoots and needles elongating; (2) elongation complete, needles maturing; and (3) needles mature. Diameter growth rate had two peaks, one about the...

  7. Harmful Algae Bloom Occurrence in Urban Ponds: Relationship of Toxin Levels with Cell Density and Species Composition

    Science.gov (United States)

    Retention ponds constructed within urban watershed areas of high density populations are common as a result of green infrastructure applications. Several urban ponds in the Northern Kentucky area were monitored for algal community (algae and cyanobacteria) from October 2012 to Se...

  8. Oxygen tension in human tumours measured with polarographic needle electrodes and its relationship to vascular density, necrosis and hypoxia

    International Nuclear Information System (INIS)

    Lyng, Heidi; Sundfoer, Kolbein; Rofstad, Einar K.

    1997-01-01

    Background and purpose: The use of polarographic needle electrodes for measurement of oxygen tension (pO 2 ) in tumours requires documentation of the validity of the method. In the present work the pO 2 values measured polarographically with the Eppendorf pO 2 histograph in human tumours were compared with the histological appearance of the tumour tissue, i.e. vascular density, fraction of necrosis and fraction of hypoxic tissue, to investigate whether the measurements reflected the expected pO 2 . Materials and methods: The pO 2 was measured in cervix tumours in patients and in human melanoma xenografted tumours in athymic mice. Vascular density was determined in the cervix tumours by histological analysis of biopsies from the pO 2 measurement tracks. Fraction of necrosis and fraction of hypoxic tissue, i.e. tissue binding the hypoxia marker pimonidazole, were determined in the melanomas by analysis of histological sections from the tumour planes in which the pO 2 measurements were performed. Results: The pO 2 distributions showed large intratumour heterogeneity. In cervix tumours, tumour regions with vascular density (vascular length per unit tissue volume) in the range of 47-77 mm/mm 3 showed higher pO 2 than tumour regions with vascular density in the range of 20-47 mm/mm 3 , which in turn showed higher pO 2 than tumour regions with vascular density in the range of 0-20 mm/mm 3 . In melanomas, tumour regions in which necrosis and hypoxia constituted more than 50% of the tissue showed lower pO 2 than other tumour regions. Conclusions: The pO 2 measured in the tumours was consistent with the histological appearance of the tissue in which the measurements were performed, suggesting that reliable pO 2 distributions of tumours can be obtained with polarographic needle electrodes

  9. New Insight into Fat, Muscle and Bone Relationship in Women: Determining the Threshold at Which Body Fat Assumes Negative Relationship with Bone Mineral Density

    Directory of Open Access Journals (Sweden)

    Pei-Yang Liu

    2014-01-01

    Conclusions: Although LM has strong positive relationship with BMD, FM above 33% in overweight/obese women is negatively related to BMD of most skeletal sites. Therefore, overweight/obesity after certain amount of FM, may not be a protective factor against osteoporosis in females. For clinical practice in women, it is important to maintain LM and keep FM accrual below ~30% body fat to maintain good skeletal health.

  10. A Study of the Relationship between Average Transverse Momentum and Charged Pseudorapidity Density for Pions and Antiprotons at Tevatron Energies

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Philip Lawrence [Purdue U.

    1991-12-01

    The transverse momentum of $\\pi^{\\pm}$ and $\\overline{p}$ produced within the pseudorapidity range of $\\eta$ = -0.36 to +1.0 and azimuthal range of $\\phi$ = +2° to $\\phi$ = +18° has been measured in $\\overline{p}p$ collisions at $\\sqrt{s}$ = 546, 1000 and 1800 GeV. The charged multiplicity of each event was measured by either the 240 element cylindrical hodoscope covering the range -3.25 < $\\eta$ < +3.25 or the central drift chamber, which spans a pseudorapidity range of 3.2 units. The average transverse momentum as a function of the pseudorapidity density for mass-identified particles is presented. Pseudorapidity densities as high as 30 particles per unit pseudorapidity have been observed.

  11. Analyzing the Profile Effects of the Various Magnet Shapes in Axial Flux PM Motors by Means of 3D-FEA

    Directory of Open Access Journals (Sweden)

    Emrah Cetin

    2018-01-01

    Full Text Available Axial flux machines have positive sides on the power and torque density profile. However, the price of this profile is paid by the torque ripples and irregular magnetic flux density production. To gather higher efficiency, torque ripples should close to the zero and the stator side iron should be unsaturated. Torque ripples mainly occur due to the interaction between the rotor poles and the stator teeth. In this study, different rotor poles are investigated in contrast to stator magnetic flux density and the torque ripple effects. Since the components of the axial flux machines vary by the radius, analysis of the magnetic resources is more complicated. Thus, 3D-FEA (finite element analysis is used to simulate the effects. The infrastructure of the characteristics which are obtained from the 3D-FEA analysis is built by the magnetic equivalent circuit (MAGEC analysis to understand the relationships of the parameters. The principal goal of this research is a smoother distribution of the magnetic flux density and lower torque ripples. As the result, the implementations on the rotor poles have interesting influences on the torque ripple and flux density profiles. The MAGEC and 3D-FEA results validate each other. The torque ripple is reduced and the magnetic flux density is softened on AFPM irons. In conclusion, the proposed rotors have good impacts on the motor performance.

  12. The Relationship of Disordered Eating Attitudes with Stress Level, Bone Turnover Markers, and Bone Mineral Density in Obese Adolescents

    OpenAIRE

    Okbay G?ne?, Asl?; Alika?ifo?lu, M?jgan; ?en Demird??en, Ezgi; Ergin?z, Ethem; Demir, T?rkay; Kucur, Mine; Ercan, Oya

    2017-01-01

    Objective: To investigate the effect of stress caused by disordered eating attitudes on bone health in obese adolescents. Methods: A cross-sectional study comprising 80 obese adolescents was performed from November 2013 to September 2014. Twenty-four-hour urinary free cortisol levels were measured as a biological marker of stress. Bone turnover was evaluated using bone-specific alkaline phosphatase, serum osteocalcin, and urinary N-telopeptide concentrations. Bone mineral density was measured...

  13. Dew water isotopic ratios and their relationships to ecosystem water pools and fluxes in a cropland and a grassland in China.

    Science.gov (United States)

    Wen, Xue-Fa; Lee, Xuhui; Sun, Xiao-Min; Wang, Jian-Lin; Hu, Zhong-Min; Li, Sheng-Gong; Yu, Gui-Rui

    2012-02-01

    Dew formation has the potential to modulate the spatial and temporal variations of isotopic contents of atmospheric water vapor, oxygen and carbon dioxide. The goal of this paper is to improve our understanding of the isotopic interactions between dew water and ecosystem water pools and fluxes through two field experiments in a wheat/maize cropland and in a short steppe grassland in China. Measurements were made during 94 dew events of the D and (18)O compositions of dew, atmospheric vapor, leaf, xylem and soil water, and the whole ecosystem water flux. Our results demonstrate that the equilibrium fractionation played a dominant role over the kinetic fractionation in controlling the dew water isotopic compositions. A significant correlation between the isotopic compositions of leaf water and dew water suggests a large role of top-down exchange with atmospheric vapor controlling the leaf water turnover at night. According to the isotopic labeling, dew water consisted of a downward flux of water vapor from above the canopy (98%) and upward fluxes originated from soil evaporation and transpiration of the leaves in the lower canopy (2%).

  14. Relationship between femur neck bone mineral density and prevalent chronic obstructive pulmonary disease (COPD) or COPD mortality in older non-Hispanic white adults from NHANES III.

    Science.gov (United States)

    Looker, A C

    2014-03-01

    The relationship between femur neck bone mineral density (FNBMD), prevalent COPD, and COPD mortality was examined in older non-Hispanic white adults from NHANES III. FNBMD was significantly related to prevalent COPD and COPD mortality before and after adjusting for shared risk factors. Bone mineral density (BMD) has been linked to chronic obstructive pulmonary disease (COPD), but little is known about its relationship with COPD mortality. The present study examined the relationship between FNBMD, prevalent COPD, and COPD mortality in older non-Hispanic white adults from the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994). COPD status at baseline was defined by self-reported physician's diagnosis and by airway obstruction based on spirometry measurements in 3,275 non-Hispanic whites aged 50 years and older. COPD mortality cases were identified using linked mortality records obtained through 2006. FNBMD was measured by dual-energy x-ray absorptiometry. Multiple regression was used to examine the baseline relationship between COPD and FNBMD. Cox proportional hazards models were used to estimate the hazards ratio (HR) for COPD mortality by FNBMD. Twelve percent self-reported a physician's diagnosis of COPD, 23 % had mild or moderate airway obstruction, and 9 % had severe or very severe airway obstruction. There were 180 COPD mortality cases in the sample. FNBMD was significantly lower in those with self-reported COPD diagnosis or airway obstruction before and after adjusting for shared risk factors (p COPD mortality risk was significantly increased for each standard deviation decline in FNBMD before (by 68 %) and after (by 26-38 %) adjusting for shared risk factors. Low FNBMD was associated with both baseline COPD and future COPD mortality. Shared risk factors appeared to explain some, but not all, of these relationships.

  15. Analysis of the Relationship Between the Solar X-Ray Radiation Intensity and the D-Region Electron Density Using Satellite and Ground-Based Radio Data

    Science.gov (United States)

    Nina, Aleksandra; Čadež, Vladimir M.; Bajčetić, Jovan; Mitrović, Srdjan T.; Popović, Luka Č.

    2018-04-01

    Increases in the X-ray radiation that is emitted during a solar X-ray flare induce significant changes in the ionospheric D region. Because of the numerous complex processes in the ionosphere and the characteristics of the radiation and plasma, the causal-consequential relationship between the X-ray radiation and ionospheric parameters is not easily determined. In addition, modeling the ionospheric D-region plasma parameters is very difficult because of the lack of data for numerous time- and space-dependent physical quantities. In this article we first give a qualitative analysis of the relationship between the electron density and the recorded solar X-ray intensity. After this, we analyze the differences in the relationships between the D-region response and various X-ray radiation properties. The quantitative study is performed for data observed on 5 May 2010 in the time period between 11:40 UT - 12:40 UT when the GOES 14 satellite detected a considerable X-ray intensity increase. Modeling the electron density is based on characteristics of the 23.4 kHz signal emitted in Germany and recorded by the receiver in Serbia.

  16. The relationship between the optical density of cataract and its influence on retinal nerve fibre layer thickness measured with spectral domain optical coherence tomography.

    Science.gov (United States)

    Kok, Pauline H B; van den Berg, Thomas J T P; van Dijk, Hille W; Stehouwer, Marilette; van der Meulen, Ivanka J E; Mourits, Maarten P; Verbraak, Frank D

    2013-08-01

    The purpose of this study was to model the influence of cataract on Spectral Domain Optical Coherence Tomography (SDOCT) image quality and Retinal Nerve Fibre Layer (RNFL) thickness measurements. SDOCT images, made with two different devices (3DOCT-1000, Topcon and Cirrus HD-OCT), before and after cataract surgery were compared and judged against measurements from normal subjects using artificial filters simulating the effects of cataract. Optical density of the images was calculated based on a mathematical model described previously. In total, forty-eight eyes were included for pre- and postoperative cataract extraction measurements. OCT image quality significantly (p optical density and change in RNFL thickness (R = 0.941, p optical density of cataract and the cataract-induced underestimation was however limited, and mean difference ± SD between predicted and measured RNFL thickness were 1.68 ± 7.55 (3DOCT-1000) and 3.71 ± 2.97 (Cirrus HD-OCT) micron. A linear relationship exists between OCT-effective optical density of cataract and underestimation of RNFL thickness measured with OCT. This finding holds promise to correct for cataract-induced changes in RNFL measurements, but will differ for each type of OCT device. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  17. Relationships between yolk androgens and nest density, laying date, and laying order in Western Burrowing Owls (Athene cunicularia hypugaea)

    Science.gov (United States)

    Welty, J.L.; Belthoff, J.R.; Egbert, J.; Schwabl, H.

    2012-01-01

    Increases in yolk androgens within and among avian clutches have been correlated with decreased incubation time, increased aggression within a nest, increased begging behaviour, decreased immune response, and decreased life span. Although the mechanisms that lead to variability in yolk androgens within and between clutches are not completely known, yolk androgens can be a function of both social and environmental conditions. We were interested in if and how nesting density, laying date, and laying order influenced yolk androgens in Western Burrowing Owls (Athene cunicularia hypugaea (Bonaparte, 1825)) in which nest density varies considerably. In 2006 and 2007, we used radioimmunoassay to quantify the concentrations of testosterone, 5a-dihydrotestosterone, and androstenedione in the egg yolks from one early and one latelaid egg in 47 nests of Burrowing Owls located in the Morley Nelson Snake River Birds of Prey National Conservation Area in southern Idaho. Nesting density had no detectable effect on yolk androgens. Yolk androgens varied temporally and peaked in the middle of the laying season while being low before and after this time period. Within nests, late-laid eggs had higher testosterone and dihydrotestosterone than early-laid eggs; adrostendione exhibited a similar pattern in one but not both years of our study. It is possible that the seasonal pattern in yolk androgens that we observed is related to aspects of mate quality for females or declining chances of fledging success for later nesting females, whereas rises in egg androgens between early and late eggs within clutches could reflect a mechanism to assist nestlings from late-laid eggs that hatch one to several days after their siblings to better compete for resources within the nest or promote survival in the presence of larger siblings.

  18. Sleep-dependent consolidation of face recognition and its relationship to REM sleep duration, REM density and Stage 2 sleep spindles.

    Science.gov (United States)

    Solomonova, Elizaveta; Stenstrom, Philippe; Schon, Emilie; Duquette, Alexandra; Dubé, Simon; O'Reilly, Christian; Nielsen, Tore

    2017-06-01

    Face recognition is a highly specialized capability that has implicit and explicit memory components. Studies show that learning tasks with facial components are dependent on rapid eye movement and non-rapid eye movement sleep features, including rapid eye movement sleep density and fast sleep spindles. This study aimed to investigate the relationship between sleep-dependent consolidation of memory for faces and partial rapid eye movement sleep deprivation, rapid eye movement density, and fast and slow non-rapid eye movement sleep spindles. Fourteen healthy participants spent 1 night each in the laboratory. Prior to bed they completed a virtual reality task in which they interacted with computer-generated characters. Half of the participants (REMD group) underwent a partial rapid eye movement sleep deprivation protocol and half (CTL group) had a normal amount of rapid eye movement sleep. Upon awakening, they completed a face recognition task that contained a mixture of previously encountered faces from the task and new faces. Rapid eye movement density and fast and slow sleep spindles were detected using in-house software. The REMD group performed worse than the CTL group on the face recognition task; however, rapid eye movement duration and rapid eye movement density were not related to task performance. Fast and slow sleep spindles showed differential relationships to task performance, with fast spindles being positively and slow spindles negatively correlated with face recognition. The results support the notion that rapid eye movement and non-rapid eye movement sleep characteristics play complementary roles in face memory consolidation. This study also raises the possibility that fast and slow spindles contribute in opposite ways to sleep-dependent memory consolidation. © 2017 European Sleep Research Society.

  19. Relationship between snail population density and infection status of snails and fish with zoonotic trematodes in Vietnamese carp nurseries

    DEFF Research Database (Denmark)

    Clausen, Jesper Hedegaard; Madsen, Henry; Murrell, Kenneth Darwin

    2012-01-01

    ponds. Previous risk assessment on FZT transmission in the Red River Delta of Vietnam identified carp nursery ponds as major sites of transmission. In this study, we analyzed the association between snail population density and heterophyid trematode infection in snails with the rate of FZT transmission......Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm...

  20. Increased bronchial density of CD25+Foxp3+ regulatory T cells in occupational asthma: relationship to current smoking.

    Science.gov (United States)

    Sjåheim, T B; Bjørtuft, Ø; Drabløs, P A; Kongerud, J; Halstensen, T S

    2013-05-01

    To identify activated T cell subset in the asthmatic bronchia, we developed a triple-colour immunohistofluorescence labelling technique on cryo-section to discriminate activated CD4+CD25+ T cells, (effector T cells) from Foxp3+ regulatory T cells (Treg). Additional coexpression of activation and proliferation markers was also examined in situ. Bronchial biopsies were taken from 20 aluminium potroom workers (12 smokers) with asthma (>12% reversibility), 15 non-asthmatic potroom workers (7 smokers) and 10 non-smoking, non-exposed controls. Non-smoking asthmatics had significantly higher subepithelial density of both Tregs, effector T cells, activated (HLA-DR+) CD8+ and activated CD4+ T cells. Moreover, both Tregs, effector T cells and CD8+ T cells proliferated in the non-smoking asthmatics, only. Although smoking asthmatics had no asthma-associated increase in bronchial T cell, both had a significantly increase in effector T cell to Treg ratios. The significantly increased bronchial density of Tregs, effector T cells, proliferative T cells and activated CD8+ T cells in non-smoking asthmatics clearly showed that both the effector T cells and the inhibitory Treg system were activated in asthma. © 2013 The Authors. Scandinavian Journal of Immunology © 2013 Blackwell Publishing Ltd.

  1. Critical flux determination by flux-stepping

    DEFF Research Database (Denmark)

    Beier, Søren; Jonsson, Gunnar Eigil

    2010-01-01

    In membrane filtration related scientific literature, often step-by-step determined critical fluxes are reported. Using a dynamic microfiltration device, it is shown that critical fluxes determined from two different flux-stepping methods are dependent upon operational parameters such as step......, such values are more or less useless in itself as critical flux predictors, and constant flux verification experiments have to be conducted to check if the determined critical fluxes call predict sustainable flux regimes. However, it is shown that using the step-by-step predicted critical fluxes as start...

  2. Investigation of Structure and Reactivity Relationship in M-N-C Type Catalysts using Density Functional Tight Binding

    Energy Technology Data Exchange (ETDEWEB)

    Negre, Christian Francisco Andres [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gonzales, Ivana [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-20

    Catalysts inhibition studies were performed to indisputably confirm the role of various metal, carbon, and nitrogen moieties in the individual steps of oxygen reduction reaction (ORR) on M-N-C catalysts. ORR activity was studied at University of New Mexico by rotating ring disk electrode method in the acidic electrolyte with the addition of Tris (tris(hydroxymethyl)-aminomethane) as inhibiting agent. To understand the interaction of Tris with different defects that exist in Fe-N-C materials and provide the support for the experimental data, we used density functional theory (DFT) and modeled the interaction of protonated Tris (TrisH) with Fe containingcenters (Fe-N4 and Fe-N2C2), pyridinic nitrogen, graphitic nitrogen, and pyrrolic nitrogen both as in plane and edge defects.

  3. Morphology-Property relationship of high density Polyethylene/Hevea Brasiliensis Leaves/Imperata cylindrica hybrid composite: Impact strength

    Science.gov (United States)

    Rashidi, A. R.; Muhammad, A.; Roslan, A.

    2017-09-01

    This research studies about the Hevea Brasiliensis Leaves and Imperata Cylindrica that was used as filler in High Density Polyethylene (HDPE). The fillers content were varied in the composite by 5 wt%, 15 wt% and 25 wt% respectively. This polymer composite are being studied by using Impact Test and Scanning Electron Microscopy (SEM). The analysis show that the impact strength value increased when the percent of bio filler used is low. The result between pure HDPE and the composites shows an outcome of significant changes in impact energy values, while the values between different composite change slightly. A composite that contained 5 wt% of fillers is the better energy absorber than 15 wt% and 25 wt% according to impact testing. In addition, the morphology studies on the composite sample show that the bio-filler was successfully embedded. Overall, these finding suggest that HBL and IC can be an alternative filler to be incorporated in polymer matrix.

  4. Relationship between crystal structure and thermo-mechanical properties of kaolinite clay: beyond standard density functional theory.

    Science.gov (United States)

    Weck, Philippe F; Kim, Eunja; Jové-Colón, Carlos F

    2015-07-28

    The structural, mechanical and thermodynamic properties of 1 : 1 layered dioctahedral kaolinite clay, with ideal Al2Si2O5(OH)4 stoichiometry, were investigated using density functional theory corrected for dispersion interactions (DFT-D2). The bulk moduli of 56.2 and 56.0 GPa predicted at 298 K using the Vinet and Birch-Murnaghan equations of state, respectively, are in good agreement with the recent experimental value of 59.7 GPa reported for well-crystallized samples. The isobaric heat capacity computed for uniaxial deformation of kaolinite along the stacking direction reproduces calorimetric data within 0.7-3.0% from room temperature up to its thermal stability limit.

  5. From elementary flux modes to elementary flux vectors: Metabolic pathway analysis with arbitrary linear flux constraints

    Science.gov (United States)

    Klamt, Steffen; Gerstl, Matthias P.; Jungreuthmayer, Christian; Mahadevan, Radhakrishnan; Müller, Stefan

    2017-01-01

    Elementary flux modes (EFMs) emerged as a formal concept to describe metabolic pathways and have become an established tool for constraint-based modeling and metabolic network analysis. EFMs are characteristic (support-minimal) vectors of the flux cone that contains all feasible steady-state flux vectors of a given metabolic network. EFMs account for (homogeneous) linear constraints arising from reaction irreversibilities and the assumption of steady state; however, other (inhomogeneous) linear constraints, such as minimal and maximal reaction rates frequently used by other constraint-based techniques (such as flux balance analysis [FBA]), cannot be directly integrated. These additional constraints further restrict the space of feasible flux vectors and turn the flux cone into a general flux polyhedron in which the concept of EFMs is not directly applicable anymore. For this reason, there has been a conceptual gap between EFM-based (pathway) analysis methods and linear optimization (FBA) techniques, as they operate on different geometric objects. One approach to overcome these limitations was proposed ten years ago and is based on the concept of elementary flux vectors (EFVs). Only recently has the community started to recognize the potential of EFVs for metabolic network analysis. In fact, EFVs exactly represent the conceptual development required to generalize the idea of EFMs from flux cones to flux polyhedra. This work aims to present a concise theoretical and practical introduction to EFVs that is accessible to a broad audience. We highlight the close relationship between EFMs and EFVs and demonstrate that almost all applications of EFMs (in flux cones) are possible for EFVs (in flux polyhedra) as well. In fact, certain properties can only be studied with EFVs. Thus, we conclude that EFVs provide a powerful and unifying framework for constraint-based modeling of metabolic networks. PMID:28406903

  6. Relationships of Macular Pigment Optical Density With Plasma Lutein, Zeaxanthin, and Diet in an Elderly Population: The Montrachet Study.

    Science.gov (United States)

    Alassane, Seydou; Binquet, Christine; Cottet, Vanessa; Fleck, Olivier; Acar, Niyazi; Daniel, Sandrine; Delcourt, Cécile; Bretillon, Lionel; Bron, Alain M; Creuzot-Garcher, Catherine

    2016-03-01

    To investigate the association of macular pigment optical density (MPOD) with plasma lutein, zeaxanthin, and diet in an elderly population. We conducted a population-based study, the Montrachet (Maculopathy Optic Nerve, nuTRition neurovAsCular, and HEarT disease) study, in subjects older than 75 years. The MPOD was measured by means of the two-wavelength autofluorescence technique. Plasma lutein and zeaxanthin were measured in fasting blood samples using HPLC. Food frequency consumption was assessed with self-reported food frequency questionnaires. Overall, 433 healthy participants (62.1% females) were included. Mean age was 82.0 ± 3.6 years. Mean MPOD at 0.5° eccentricity was 0.57 ± 0.25 density units (DU) and was higher in women than in men (0.59 ± 0.25 vs. 0.53 ± 0.25, P = 0.017). The MPOD was lower in alcohol consumers than in non-alcohol consumers (0.55 ± 0.25 vs. 0.61 ± 0.25, P = 0.016). Median plasma lutein and zeaxanthin levels were 281.4 μg/L and 20.0 μg/L, respectively, and were higher in women (P = 0.010 and P = 0.003, respectively). The MPOD was positively correlated with plasma lutein and zeaxanthin (r = 0.10, P = 0.030 and r = 0.11, P = 0.027, respectively). A higher consumption of squash was associated with higher plasma lutein and zeaxanthin. Adjusting for confounders and diet revealed that MPOD was weakly associated with plasma lutein in nonsmokers (β = 0.11, P = 0.021). This study suggests that plasma lutein is associated with MPOD after taking into account potential confounding factors in an elderly population.

  7. Seismic velocities - density relationship for the Earth's crust: effects of chemical compositions, amount of water, and implications on gravity and topography

    Science.gov (United States)

    Guerri, Mattia; Cammarano, Fabio

    2014-05-01

    Seismic velocities - density relationship for the Earth's crust: effects of chemical compositions, amount of water, and implications on gravity and topography Mattia Guerri and Fabio Cammarano Department of Geosciences and Natural Resource Management, Section of Geology, University of Copenhagen, Denmark. A good knowledge of the Earth's crust is not only important to understand its formation and dynamics, but also essential to infer mantle seismic structure, dynamic topography and location of seismic events. Global and local crustal models available (Bassin et al., 2000; Nataf & Ricard, 1996; Molinari & Morelli, 2011) are based on VP-density empirical relationships that do not fully exploit our knowledge on mineral phases forming crustal rocks and their compositions. We assess the effects of various average crustal chemical compositions on the conversion from seismic velocities to density, also testing the influence of water. We consider mineralogies at thermodynamic equilibrium and reference mineral assemblages at given P-T conditions to account for metastability. Stable mineral phases at equilibrium have been computed with the revised Holland and Powell (2002) EOS and thermodynamic database implemented in PerpleX (Connolly 2005). We have computed models of physical properties for the crust following two approaches, i) calculation of seismic velocities and density by assuming the same layers structure of the model CRUST 2.0 (Bassin et al., 2000) and a 3-D thermal structure based on heat-flow measurements; ii) interpretation of the Vp model reported in CRUST 2.0 to obtain density and shear wave velocity for the crustal layers, using the Vp-density relations obtained with the thermodynamic modeling. The obtained density models and CRUST 2.0 one have been used to calculate isostatic topography and gravity field. Our main results consist in, i) phase transitions have a strong effect on the physical properties of crustal rocks, in particular on seismic velocities; ii

  8. Natural factors and antropics and their relationship with the density of colonies of Melipona beecheii in five vegetable formations of the valley San Andres

    Directory of Open Access Journals (Sweden)

    Katiuska Ravelo Pimentel

    2014-12-01

    Full Text Available It is evaluated the influence of natural factors and antropics on the density of colonies of Melipona beecheii in forest five vegetable formations of the solid one of the valley San Andrés, through surveys to residents and workers of the area, as well as the observations and samplings carried out in the studied vegetable formations. The following factors were studied: rocosity, vegetable covering, flourished plants, height of the entrance hole and the man's activity; being determined that the density of beehives has been affected fundamentally by factors antropics, having this its biggest incidence in the gallery forests, being this the most affected one. The pruning of trees, the naturalness of the forests and their access affect the population's conservation considerably under natural conditions, what demonstrates that this it is the main factor that locates in extirpation danger to the species in the study area. In turn the density of colonies keeps direct relationship with the other analyzed factors, since the same ones depend on the trees for the location of its nests, of the time in that the plants flourish for its feeding and of the holes found in the rocks, so much for the making of its colonies like it stops its establishment and reproduction.

  9. Effect of regular anti-osteoporosis treatment on bone mineral density and bone metabolism in patients with primary osteoporosis and its relationship with bone fractures

    Directory of Open Access Journals (Sweden)

    Xue-Feng Qian

    2016-12-01

    Full Text Available Objective: To analyze the effect of regular anti-osteoporosis treatment on bone mineral density and bone metabolism in patients with primary osteoporosis and its relationship with bone fractures. Methods: A total of 120 patients with primary osteoporosis were included in this study and randomly divided into observation group and control group (n=60. Control group received consistent treatment, observation group received individualized regular antiosteoporosis treatment, and then the differences in bone mineral density, bone metabolism, trace elements, oxidative stress, fracture incidence, and so on were compared between two groups of patients 1 year after treatment. Results: Absolute BMD value of observation group after treatment was higher than that of control group; serum bone formation indexes ALP, BGP, PⅠNP and PⅠCP content were higher than those of control group; serum bone resorption indexes β-CTX, sRANKL, TRACP, BAP and DPD content were lower than those of control group; serum trace elements iron and zinc content were higher than those of control group while calcium content was lower than that of control group; serum AOPP and MAOA content of observation group were significantly lower than those of control group while SOD and T-AOC content were significantly higher than those of control group;fracture incidence was significantly lower than that of control group during treatment. Conclusions: The regular antiosteoporosis treatment can increase bone mineral density, optimize the overall condition and reduce the incidence of long-term fracture in patients with primary osteoporosis.

  10. Intermixed terpyridine-functionalized monolayers on gold: nonlinear relationship between terpyridyl density and metal ion coordination properties.

    Science.gov (United States)

    Traulsen, Christoph H-H; Darlatt, Erik; Richter, Sebastian; Poppenberg, Johannes; Hoof, Santina; Unger, Wolfgang E S; Schalley, Christoph A

    2012-07-24

    Aiming at the functionalization of surfaces with terpyridine anchors for the coordinative deposition of additional layers, mixed self-assembled monolayers (SAMs) were prepared from binary solutions of 12-(2,2':6',2″-terpyridine-4'-yl)dodecane-1-thiol (TDT) and 1-decanethiol (DT). The SAMs and the order of the constituting molecules were analyzed by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS), and time-of-flight-secondary ion mass spectrometry (ToF-SIMS). The composition of the (TDT/DT)-SAMs and with it the surface density of terpyridyl groups correlates linearly with the relative concentrations of the two compounds in the solution used for depositing them. In marked contrast, the amount of terpyridine-coordinated Pd(II) ions significantly deviates from this trend with an optimum at a 1:3 ratio of TDT/DT. This indicates a major fraction of the terpyridines in TDT-rich SAMs not to be accessible for Pd(II) ion coordination. In agreement, NEXAFS spectroscopy reveals the alkyl backbones in TDT-rich SAMs not to be ordered, while they are preferentially upright oriented in the optimal 1:3-(TDT/DT)-SAMs. We interpret this in terms of terpyridine backfolding in TDT-rich SAMs, while they are located in accessible positions on top of the SAM in the 1:3-(TDT/DT)-SAM. While the alkyl backbones in the 1:3-(TDT/DT)-SAM are ordered, NEXAFS spectroscopy shows the terpyridyl groups not to have a preferential orientation in this SAM and thus retain enough flexibility to adjust to molecules that are deposited on top of the mixed SAM. In conclusion, the novel SAM does not undergo phase separation and consists predominantly of intermixed phases with adjustable surface density of quite flexible terpyridine anchor groups. The terpyridine-Pd(II) anchors are not only available for a future deposition of the next layer, but the metal ions also represent a sensitive probe for the accessibility of the terpyridyl groups.

  11. Relationship among panoramic radiography findings, biochemical markers of bone turnover and hip bone mineral density in the diagnosis of postmenopausal osteoporosis

    International Nuclear Information System (INIS)

    Johari Khatoonabad, M.; Aghamohammadzade, N.; Taghilu, H.; Esmaeili, F.; Jabbari Khamnei, H.

    2011-01-01

    Recent investigations have shown that panoramic radiography might be a useful tool in the early diagnosis of osteoporosis. In addition, bone turnover biochemical marker might be valuable in predicting osteoporosis and fracture risks in the elderly, especially in post-menopausal women. The aim of the present study was to evaluate the relationship among the radio morphometric indices of the mandible, biochemical markers of the bone turnover and hip bone mineral density in a group of post-menopausal women. Patients and Methods: Evaluations of mandibular cortical width, mandibular cortical index, panoramic index and alveolar crest resorption ration (M/M ration) were carried out on panoramic radiographs of 140 post-menopausal women with an age range of 44-82 years. Hip bone mineral density was measured by dual-energy X-ray absorptiometry method. Bone mineral density values were divided into three groups of normal (T score>-1.0), Osteopenic (T score, -2.5 to -1.0) and Osteoporotic (T score<-2.5). Serum alkaline phosphatase and 25(OH) D3 were measured. Results: A decrease in mandibular cortical width by 1 mm increases the likelihood of osteopenia or osteoporosis up to 40%, having taken into consideration the effect of menopause duration. A 1 mm decrease in mandibular cortical width increased the likelihood of moderate or severe erosion of the lower cortex of the mandible up to 28% by taking age into consideration. The results did not demonstrate a statistically significant relationship between bone turnover markers and mandibular radio morphometric indices. Conclusion: Panoramic radiography gives sufficient information to make an early diagnosis regarding osteoporosis in post-menopausal women. Panoramic radiographs may be valuable in the prevention of osteoporotic fractures in elderly women.

  12. Fluxes and concentrations of volatile organic compounds above central London, UK

    Directory of Open Access Journals (Sweden)

    B. Langford

    2010-01-01

    Full Text Available Concentrations and fluxes of eight volatile organic compounds (VOCs were measured during October 2006 from a high telecom tower above central London, as part of the CityFlux contribution to the REPARTEE I campaign. A continuous flow disjunct eddy covariance technique with analysis by proton transfer reaction mass spectrometry was used. Daily averaged VOC mixing ratios were within the range 1–19 ppb for the oxygenated compounds (methanol, acetaldehyde and acetone and 0.2–1.3 ppb for the aromatics (benzene, toluene and C2-benzenes. Typical VOC fluxes were in the range 0.1–1.0 mg m−2 h−1. There was a non-linear relationship between VOC fluxes and traffic density for most of the measured compounds. Traffic activity was estimated to account for approximately 70% of the aromatic compound fluxes, whereas non-traffic related sources were found to be more important for methanol and isoprene fluxes. The measured fluxes were comparable to the estimates of the UK national atmospheric emission inventory for the aromatic VOCs and CO. In contrast, fluxes of the oxygenated compounds were about three times larger than inventory estimates. For isoprene and acetonitrile this difference was many times larger. At temperatures over 25° C it is estimated that more than half the isoprene observed in central London is of biogenic origin.

  13. Altering Conventional to High Density Spinal Cord Stimulation: An Energy Dose-Response Relationship in Neuropathic Pain Therapy.

    Science.gov (United States)

    Wille, Frank; Breel, Jennifer S; Bakker, Eric W P; Hollmann, Markus W

    2017-01-01

    To examine whether converting from conventional Spinal Cord Stimulation (SCS) to High Density (HD) SCS reduces neuropathic pain over a period of 12 months in patients with failed SCS therapy. Retrospective, open label, single center, consecutive case series of 30 neuropathic pain patients (Failed Back Surgery Syndrome [FBSS], Complex Regional Pain Syndrome [CRPS], and polyneuropathy [NP]). Patients with an initial adequate response to conventional SCS, but in whom pain increased over time, were included (Numeric Rating Scales [NRS] >6). These patients were stimulated with HD-SCS parameters and followed-up for 12 months. We report pain intensity, measured with NRS, before SCS implantation, 1 and 3 months after starting SCS with conventional stimulation, and after 1, 6, and 12 months of HD SCS. Pain reduction with conventional stimulation was initially adequate (NRS mean 8.6 to 5.3 at three months postimplant) but increased over time to a mean NRS of 7.7 at the time of reprogramming. NRS scores decreased significantly to 4.3 (p = 0.015) after reprogramming from conventional SCS (30 Hz, 300 µsec, 3.0 V) to HD SCS (409 Hz, range 130-1000 Hz, 409 µsec, 2.4V) in the patients still using HD-SCS at 12 months. In the nonresponders (patients who stopped HD-SCS for any reason), 76% had a diagnosis of FBSS. Almost half of the patients aborting HD-SCS preferred to feel paresthesias despite better pain relief. There was a significant difference between nonresponders and responders regarding the amount of electrical energy delivered to the spinal cord. Neuropathic pain suppression is significantly enhanced after converting from failed conventional SCS to HD SCS in patients with FBSS, CRPS, and NP over a measured period of 12 months. There appears to be a dose-related response between the amount of energy delivered to the spinal cord and clinical effect. © 2016 International Neuromodulation Society.

  14. High density lipoprotein-3 in diabetic retinopathy patients: relationship to total antioxidant capacity and nitric oxide level

    Directory of Open Access Journals (Sweden)

    Ustundag Yasemin

    2017-12-01

    Full Text Available AIM: To examine the association between high density lipoprotein(HDL3 cholesterol, nitrite plus nitrate(NOxand total antioxidant status in diabetic retinopathy patients compared to controls.METHODS: This was a prospective, case-control study. One hundred and six participants were subdivided into three groups. Eighty-four type 2 diabetes patients with and without retinopathy and 22 healthy controls were included in this study. Serum HDL3 concentrations were assayed and serum NOx levels were determined in all patients. Total antioxidant capacity was measured using the ferric reducing power of plasma(FRAPassay.RESULTS: Among the subjects with diabetes mellitus(DM, fasting glucose, HbA1c and triglycerides were significantly higher than the healthy controls. HDL3 level was 14.4(12.0mg/dl in healthy subjects, 18.1(12.6mg/dl in the diabetic retinopathy group and 14.0(12.5mg/dl in diabetic patients without retinopathy, and was statistically similar between the groups(P=0.262. HDL level was similar between groups in our population. FRAP level was lower in patients with DM compared to healthy controls(P=0.003, but was not different between the DR and the non-DR groups(P=0.913.CONCLUSION: In our study, we demonstrated that HDL and HDL3 subgroup levels didn't significantly differ between DM2 patients with DR and without DR and healthy controls. Determination of HDL3 cholesterol, in addition to total HDL cholesterol, may not predict the actual risk for diabetic retinopathy. Serum NOx was observed to be higher in diabetic participants and FRAP level was low.

  15. Heat Flux Inhibition by Whistlers: Experimental Confirmation

    International Nuclear Information System (INIS)

    Eichler, D.

    2002-01-01

    Heat flux in weakly magnetized collisionless plasma is, according to theoretical predictions, limited by whistler turbulence that is generated by heat flux instabilities near threshold. Observations of solar wind electrons by Gary and coworkers appear to confirm the limit on heat flux as being roughly the product of the magnetic energy density and the electron thermal velocity, in agreement with prediction (Pistinner and Eichler 1998)

  16. Relationship between chronological and bone ages and pubertal stage of breasts with bone biomarkers and bone mineral density in adolescents.

    Science.gov (United States)

    Fortes, Cristina Maria Teixeira; Goldberg, Tamara Beres Lederer; Kurokawa, Cilmery Suemi; Silva, Carla Cristiani; Moretto, Maria Regina; Biason, Talita Poli; Teixeira, Altamir Santos; Nunes, Hélio Rubens de Carvalho

    2014-01-01

    To study bone mineral density (BMD) in adolescent females according to five groups of chronological age (CA), bone age (BA), and breast development stage (B), and to correlate these parameters with plasma bone biomarkers (BB). This was a cross-sectional study performed in 101 healthy adolescent females between 10 and 20 years old. The study variables were: weight, height, body mass index (BMI), CA, B, BA, calcium intake, BMD, and BB. Osteocalcin (OC), bone alkaline phosphatase (BAP), and C-terminal telopeptide (S-CTx) were evaluated for BB. BMD was measured using dual energy X-ray absorptiometry (DXA). BMD in lumbar spine, proximal femur, and total body increased with age, and the respective observed averages were: in CA1 (10 years old), 0.631, 0.692, 0.798 g/cm(2); in CA2 (11 to 12 years old), 0.698, 0.763, 0.840 g/cm(2); in CA3 (13 to 14 years old), 0.865, 0.889, 0.972 g/cm(2); in CA4 (15 to 16 years old), 0.902, 0.922, 1.013 g/cm(2); and in CA5 (17 to 19 years old), 0.944, 0.929, 1.35 g/cm(2). These results showed significant differences between 13 and 14 years of age (CA3) or when girls reached the B3 stage (0.709, 0.832, 0.867 g/cm(2)). The highest median concentrations of BB were between 10 and 12 years of age when adolescents were in the B2-B3 (p<0.001). Median BB concentrations decreased in advanced BA and B. BB concentrations were positively correlated with the peak height velocity and negatively correlated with BMD in the study sites. Increased BMD and BB concentrations were observed in B3. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  17. Interrelationship between cloud cover and sensible heat flux over ...

    Indian Academy of Sciences (India)

    higher (lower) magnitudes of these fluxes in dry. (moist) convective sector. However, these fluxes when day-time averaged, were found to bear no sig- nificant relationship with evening cloud cover. Such negative relationship between sensible heat fluxes (SHF) and total cloud cover (TCC) appears to be contradictory to the ...

  18. [Spatiotempaoral distribution patterns of photosynthetic photon flux density, air temperature, and relative air humidity in forest gap of Pinus koraiensis-dominated broadleaved mixed forest in Xi-ao Xing' an Mountains].

    Science.gov (United States)

    Li, Meng; Duan, Wen-biao; Chen, Li-xin

    2009-12-01

    A continuous measurement of photosynthetic photon flux density (PPFD), air temperature, and relative air humidity was made in the forest gap in primary Pinus koraiensis-dominated broadleaved mixed forest in Xiao Xing' an Mountains to compare the spatiotemporal distribution patterns of the parameters. The diurnal maximum PPFD in the forest gap appeared between 11:00 and 13:00 on sunny and overcast days. On sunny days, the maximum PPFD during various time periods did not locate in fixed locations, the diurnal maximum PPFD occurred in the canopy edge of northern part of the gap; while on overcast days, it always occurred in the center of the gap. The mean monthly PPFD in the gap was the highest in June and the lowest in September, with the largest range observed in July. The maximum air temperature happened between 9:00 and 15:00 on sunny days, between 15:00 and 19:00 on overcast days, the locations were 8 m in the southern part of gap center both on sunny and overcast days. From 5:00 to 9:00, the air temperature at measured positions in the gap was higher on overcast days than on sunny days; but from 9:00 to 19:00, it was opposite. The mean monthly air temperature was the highest in June, and the lowest in September. The maximum relative humidity appeared between 5:00 and 9:00 on sunny and overcast days, and occurred in the canopy border of western part of the gap, with the relative air humidity on overcast days being always higher than that on sunny days. The mean monthly relative humidity was the highest in July, and the lowest in June. The heterogeneity of PPFD was higher on sunny days than on overcast days, but the heterogeneities of air temperature and relative humidity were not obvious. The maximum PPFD, air temperature, and relative humidity were not located in the same positions among different months during growing season. For mean monthly PPFD and air temperature, their variation gradient was higher in and around the center of gap; while for mean monthly

  19. The relationships between breast volume, breast dense volume and volumetric breast density with body mass index, body fat mass and ethnicity

    Science.gov (United States)

    Zakariyah, N.; Pathy, N. B.; Taib, N. A. M.; Rahmat, K.; Judy, C. W.; Fadzil, F.; Lau, S.; Ng, K. H.

    2016-03-01

    It has been shown that breast density and obesity are related to breast cancer risk. The aim of this study is to investigate the relationships of breast volume, breast dense volume and volumetric breast density (VBD) with body mass index (BMI) and body fat mass (BFM) for the three ethnic groups (Chinese, Malay and Indian) in Malaysia. We collected raw digital mammograms from 2450 women acquired on three digital mammography systems. The mammograms were analysed using Volpara software to obtain breast volume, breast dense volume and VBD. Body weight, BMI and BFM of the women were measured using a body composition analyser. Multivariable logistic regression was used to determine the independent predictors of increased overall breast volume, breast dense volume and VBD. Indians have highest breast volume and breast dense volume followed by Malays and Chinese. While Chinese are highest in VBD, followed by Malay and Indian. Multivariable analysis showed that increasing BMI and BFM were independent predictors of increased overall breast volume and dense volume. Moreover, BMI and BFM were independently and inversely related to VBD.

  20. Using modern plant trait relationships between observed and theoretical maximum stomatal conductance and vein density to examine patterns of plant macroevolution.

    Science.gov (United States)

    McElwain, Jennifer C; Yiotis, Charilaos; Lawson, Tracy

    2016-01-01

    Understanding the drivers of geological-scale patterns in plant macroevolution is limited by a hesitancy to use measurable traits of fossils to infer palaeoecophysiological function. Here, scaling relationships between morphological traits including maximum theoretical stomatal conductance (gmax ) and leaf vein density (Dv ) and physiological measurements including operational stomatal conductance (gop ), saturated (Asat ) and maximum (Amax ) assimilation rates were investigated for 18 extant taxa in order to improve understanding of angiosperm diversification in the Cretaceous. Our study demonstrated significant relationships between gop , gmax and Dv that together can be used to estimate gas exchange and the photosynthetic capacities of fossils. We showed that acquisition of high gmax in angiosperms conferred a competitive advantage over gymnosperms by increasing the dynamic range (plasticity) of their gas exchange and expanding their ecophysiological niche space. We suggest that species with a high gmax (> 1400 mmol m(-2) s(-1) ) would have been capable of maintaining a high Amax as the atmospheric CO2 declined through the Cretaceous, whereas gymnosperms with a low gmax would experience severe photosynthetic penalty. Expansion of the ecophysiological niche space in angiosperms, afforded by coordinated evolution of high gmax , Dv and increased plasticity in gop , adds further functional insights into the mechanisms driving angiosperm speciation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  1. Relationship between the line of density anomaly and the lines of melting, crystallization, cavitation, and liquid spinodal in coarse-grained water models

    Science.gov (United States)

    Lu, Jibao; Chakravarty, Charusita; Molinero, Valeria

    2016-06-01

    Liquid water has several anomalous properties, including a non-monotonous dependence of density with temperature and an increase of thermodynamic response functions upon supercooling. Four thermodynamic scenarios have been proposed to explain the anomalies of water, but it is not yet possible to decide between them from experiments because of the crystallization and cavitation of metastable liquid water. Molecular simulations provide a versatile tool to study the anomalies and phase behavior of water, assess their agreement with the phenomenology of water under conditions accessible to experiments, and provide insight into the behavior of water in regions that are challenging to probe in the laboratory. Here we investigate the behavior of the computationally efficient monatomic water models mW and mTIP4P/2005REM, with the aim of unraveling the relationships between the lines of density extrema in the p-T plane, and the lines of melting, liquid-vapor spinodal and non-equilibrium crystallization and cavitation. We focus particularly on the conditions for which the line of density maxima (LDM) in the liquid emerges and disappears as the pressure is increased. We find that these models present a retracing LDM, same as previously found for atomistic water models and models of other tetrahedral liquids. The low-pressure end of the LDM occurs near the pressure of maximum of the melting line, a feature that seems to be general to models that produce tetrahedrally coordinated crystals. We find that the mW water model qualitatively reproduces several key properties of real water: (i) the LDM is terminated by cavitation at low pressures and by crystallization of ice Ih at high pressures, (ii) the LDM meets the crystallization line close to the crossover in crystallization from ice Ih to a non-tetrahedral four-coordinated crystal, and (iii) the density of the liquid at the crossover in crystallization from ice Ih to a four-coordinated non-tetrahedral crystal coincides with the

  2. Outflow of traffic from the national capital Kuala Lumpur to the north, south and east coast highways using flow, speed and density relationships

    Directory of Open Access Journals (Sweden)

    Nik Hashim Nik Mustapha

    2016-12-01

    Full Text Available The functional relationships between flow (veh/km, density (veh/h and speed (km/h in traffic congestion have a long history of research. However, their findings and techniques persist to be relevant to this day. The analysis is pertinent, particularly in finding the best fit for the three major highways in Malaysia, namely the KL-Karak Highway, KL-Seremban Highway and KL-Ipoh Highway. The trans-logarithm function of density–speed model was compared to the classical models of Greenshields, Greenberg, Underwood and Drake et al. using data provided by the Transport Statistics Malaysia 2014. The results of regression analysis revealed that the Greenshields and Greenberg models were statistically significant. The trans-logarithm function was also tested and the results were nonetheless without exception. Its usefulness in addition to statistical significance related to the derived economic concepts of maximum speed and the related number of vehicles, flow and density and the limits of free speed were relevant in comparing the individual levels of traffic congestion between highways. For instance, KL-Karak Highway was least congested compared to KL-Seremban Highway and KL-Ipoh Highway. Their maximum speeds, based on three lanes carriage capacity of one direction, were 33.4 km/h for KL-Karak, 15.9 km/h for KL-Seremban, and 21.1 km/h for KL-Ipoh. Their corresponding flows were approximated at 1080.9 veh/h, 1555.4 veh/h, and 1436.6 veh/h.

  3. Correlation between dynamic tomato fruit-set and source-sink ratio: a common relationship for different plant densities and seasons?

    Science.gov (United States)

    Kang, MengZhen; Yang, LiLi; Zhang, BaoGui; de Reffye, Philippe

    2011-04-01

    It is widely accepted that fruit-set in plants is related to source-sink ratio. Despite its critical importance to yield, prediction of fruit-set remains an ongoing problem in crop models. Functional-structural plant models are potentially able to simulate organ-level plasticity of plants. To predict fruit-set, the quantitative link between source-sink ratio and fruit-set probability is analysed here via a functional-structural plant model, GreenLab. Two experiments, each with four plant densities, were carried out in a solar greenhouse during two growth seasons (started in spring and autumn). Dynamic fruit-set probability was estimated by frequent observation on inflorescences. Source and sink parameter values were obtained by fitting GreenLab outputs for the biomass of plant parts (lamina, petiole, internode, fruit), at both organ and plant level, to corresponding destructive measurements at six dates from real plants. The dynamic source-sink ratio was calculated as the ratio between biomass production and plant demand (sum of all organ sink strength) per growth cycle, both being outputs of the model. Most sink parameters were stable over multiple planting densities and seasons. From planting, source-sink ratio increased in the vegetative stage and reached a peak after fruit-set commenced, followed by a decrease of leaf appearance rate. Fruit-set probability was correlated with the source-sink ratio after the appearance of flower buds. The relationship between fruit-set probability and the most correlated source-sink ratio could be quantified by a single regression line for both experiments. The current work paves the way to predicting dynamic fruit-set using a functional structure model.

  4. Looking for high neutron fluxes

    International Nuclear Information System (INIS)

    Lengeler, Herbert

    1994-01-01

    The neutron is a powerful and versatile probe of both the structure and dynamics of condensed matter. However unlike other techniques such as X-ray, electron or light scattering, its interaction with matter is rather weak. Historically neutron scattering has always been intensity limited and scientists are always looking for more intense sources. These come in two kinds - fission reactors and spallation sources (in which neutrons are released from a target bombardment by beams). Unfortunately the power density of high flux reactors is approaching a technical limit and it will be difficult to achieve a large increase of neutron fluxes above typical present values as represented for example by the high flux reactor at ILL, Grenoble

  5. The measurements of thermal neutron flux distribution in a paraffin

    Indian Academy of Sciences (India)

    The term `thermal flux' implies a Maxwellian distribution of velocity and energy corresponding to the most probable velocity of 2200 ms-1 at 293.4 K. In order to measure the thermal neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of ...

  6. The measurements of thermal neutron flux distribution in a paraffin ...

    Indian Academy of Sciences (India)

    The term `thermal flux' implies a Maxwellian distribution of velocity and energy corresponding to the most probable velocity of 2200 ms-1 at 293.4 K. In order to measure the thermal neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of ...

  7. California's Future Carbon Flux

    Science.gov (United States)

    Xu, L.; Pyles, R. D.; Paw U, K.; Gertz, M.

    2008-12-01

    The diversity of the climate and vegetation systems in the state of California provides a unique opportunity to study carton dioxide exchange between the terrestrial biosphere and the atmosphere. In order to accurately calculate the carbon flux, this study couples the sophisticated analytical surface layer model ACASA (Advance Canopy-Atmosphere-Soil Algorithm, developed in the University of California, Davis) with the newest version of mesoscale model WRF (the Weather Research & Forecasting Model, developed by NCAR and several other agencies). As a multilayer, steady state model, ACASA incorporates higher-order representations of vertical temperature variations, CO2 concentration, radiation, wind speed, turbulent statistics, and plant physiology. The WRF-ACASA coupling is designed to identify how multiple environmental factors, in particularly climate variability, population density, and vegetation distribution, impact on future carbon cycle prediction across a wide geographical range such as in California.

  8. Relationship among house-dust mites, Der 1, Fel d 1, and Can f 1 on clothing and automobile seats with respect to densities in houses.

    Science.gov (United States)

    Neal, Jacqueline S; Arlian, Larry G; Morgan, Marjorie S

    2002-04-01

    Locations where there are no dust mites or pets present may contain allergens that pose a risk factor for sensitizing and inducing rhinitis and asthma. The purpose of this study was to investigate the relationship among the prevalence of mites and mite, dog, and cat allergens in homes, on clothing, and on automobile seats. Over a 2-year period (July 1998 to July 2000), dust mite and mite, dog, and cat allergen densities were determined in homes, associated automobiles, and on the clothing of the drivers. During this period 87 homes were sampled one to five times each. Low levels of live and dead mites were present in most dust samples obtained from automobile seats and in 16% from clothing. Seventy-two and 50% of the home samples had >2 microg and >10 microg Der l/g of dust, respectively, whereas 23% of automobiles seat samples had >2 microg Der l/g of dust with a mean of 1.3 microg/g. Mite and Der 1 densities were not different for homes with or without pets. However, homes with pets had significantly more Fel d 1 or Can f 1 allergen than homes without pets. Homes without cats and dogs had an average of 93 and 29 microg/g of Fel d 1 and Can f 1, respectively, which was well above threshold levels for sensitization and induction of allergic reactions. Although most clothing had detectable levels of pet allergen, the levels of these allergens were low. Der 1 densities in some automobiles were sufficiently high (>2 microg/g of dust) to be risk factors for sensitization and allergic reactions. However, most automobile seats had levels of dog and cat allergen that were well above the threshold levels considered to be risk factors for both sensitization and symptoms, regardless of the presence of a pet in the home. The presence of live and dead mites and mite, cat, and dog allergens in automobiles and on clothing suggests that both are vehicles in the dispersal of mites and mite and pet allergen.

  9. Relationship between body composition and age, menopause and its effects on bone mineral density at segmental regions in Central Southern Chinese postmenopausal elderly women with and without osteoporosis.

    Science.gov (United States)

    Liu, ShiPing; Li, JianWei; Sheng, ZhiFeng; Wu, XianPing; Liao, ErYuan

    2011-01-01

    We aimed at evaluating the relationship between lean mass and fat mass with age, menopausal age (MA) and years since menopause (YSM) and their effects on bone mineral density (BMD) at segmental regions in postmenopausal elderly women with and without osteoporosis. After using a dual-energy X-ray absorptiometry (DXA) methodology to measure body composition and BMD at posteroanterior spine and hip in 244 postmenopausal elderly non-osteoporotic (Non-OP) women (65.5 ± 4.3 years) and 298 postmenopausal elderly osteoporotic (OP) women (67.1 ± 4.4 years), we found that in postmenopausal elderly Non-OP women, there was no correlation between lean mass with age, MA, and YSM, as well as no correlation between fat mass with age (all, p > 0.05); leg fat (LF) mass (r = 0.187; p 0.05); Trunk lean (TRL) mass (r = -0.183; p related with MA; WF and WL mass were the most important body composition components influencing BMD at L1-4 and hip, respectively; in postmenopausal elderly OP women, body composition was not correlated with MA; lean mass (TRL, LL, and WL) was more age-related negatively; WF mass was the most significant factor affecting BMD at lumbar spine and hip. Crown Copyright © 2010. Published by Elsevier Ireland Ltd. All rights reserved.

  10. The relationship of physical activity to high-density lipoprotein cholesterol level in a sample of community-dwelling older adults from Amazonas, Brazil.

    Science.gov (United States)

    Gouveia, Élvio R; Ihle, Andreas; Kliegel, Matthias; Freitas, Duarte L; Jurema, Jefferson; Tinôco, Maria A; Odim, Angeany; Machado, Floramara T; Muniz, Bárbara R; Antunes, António A; Ornelas, Rui T; Gouveia, Bruna R

    2017-11-01

    (1) To study the relation of physical activity (PA) to high-density lipoprotein cholesterol (HDL-C) and (2) to investigate if the strength of these associations holds after adjustments for sex, age, and other key correlates. This study included 550 older adults from Amazonas. HDL-C was derived from fasting blood samples. PA at sport and leisure, smoking, alcohol consumption, and socioeconomic status (SES) were interviewed. Waist circumference (WACI) was assessed. HDL-C was positively related to PA sport, PA leisure, and SES (0.22≤r≤0.34; p≤0.001) and negatively related to smoking and WACI (r≤-0.10; p<0.05). Controlling for sex and age did not affect these relationships. Hierarchical multiple regression analyses showed that the relation of HDL-C to PA sport and leisure remained significant when controlling for all other investigated correlates (0.14≤β≤0.24; p≤0.001). In order to prevent low HDL-C in older adults, promoting PA seems to be an important additional component besides common recommendations concerning weight reduction. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The Se-H bond of benzeneselenols (ArSe-H): Relationship between bond dissociation enthalpy and spin density of radicals

    Science.gov (United States)

    Nam, Pham Cam; Nguyen, Minh Tho

    2013-03-01

    Bond dissociation enthalpies (BDE) of benzeneselenol (ArSe-H) and its para and meta-substituted derivatives are calculated using the (RO)B3LYP/6-311++G(2df,2p)//(U)B3LYP/6-311G(d,p) procedure. The computed BDE(Se-H) = 308 ± 8 kJ/mol for the parent PhSe-H is significantly smaller than the experimental value of 326.4 ± 16.7 kJ/mol [Kenttamaa and coworkers, J. Phys. Chem. 100 (1996) 6608] but larger than a previous value of 280.3 kJ/mol [Newcomb et al., J. Am. Chem. Soc. 113 (1991) 949]. The substituent effects on BDE's are analyzed in terms of a relationship between BDE(Se-H) and Mulliken atomic spin densities at the Se radical centers of ArSe (π radicals). Good correlations between Hammett's substituent constants with BDE(Se-H) are established. Proton affinity and ionization energy amount to PA(C6H5SeH) = 814 ± 4 kJ/mol and IE(C6H5SeH) = 8.0 ± 0.1 eV. IEs of the substituted benzeneselenols are also determined. Calculated results thus suggest that 4-amino-benzeneselenol derivatives emerge as efficient antioxidants.

  12. Relationship between breast-feeding and bone mineral density among Korean women in the 2010 Korea National Health and Nutrition Examination Survey.

    Science.gov (United States)

    Yeo, Ui Hyang; Choi, Chang Jin; Choi, Whan Seok; Kim, Kyung Soo

    2016-01-01

    Breast-feeding has the deleterious effect of hypoestrogenemia coupled with loss of calcium in the maternal bone mass. It is not clear whether changes in bone metabolism in lactating women lead to changes in maternal bone mineral density (BMD) over a longer period. The aim of the present study was to investigate the relationship between the duration of breast-feeding and BMD in healthy South Korean women. We analyzed data from the 2010 Korea National Health and Nutrition Examination Survey, a cross-sectional survey of Korean citizens. A total of 1342 women older than 19 years were selected for analysis. In postmenopausal women, the duration of breast-feeding per child was associated with low lumbar spine BMD after adjustment for age, body mass index, smoking, alcohol intake, physical activity, serum 25-hydroxyvitamin D level, and daily intake of calcium and calories (P women or in femur BMD. In conclusion, the duration of breast-feeding per child is negatively correlated with lumbar spine BMD in postmenopausal women, but not in premenopausal women. Although the cause of the different results between postmenopausal and premenopausal women is not clear, our findings suggest that proper protective strategies should be recommended during prolonged breast-feeding to maintain bone health later in life.

  13. [The relationship of nutritional status, body and mandibular bone mineral density, tooth loss and fracture risk (FRAX) in pre-and postmenopausal women with periodontitis].

    Science.gov (United States)

    Aguilera-Barreiro, de Los Angeles; Dávalos-Vázquez, Karla Fabiola; Jiménez-Méndez, Carolina; Jiménez-Mendoza, Daniel; Olivarez-Padrón, Luis Ángel; Rodríguez-García, Mario Enrique

    2014-06-01

    During menopause there is weight gain and a decrease in bone mineral density (BMD) that has been related with periodontal disease (incidence between 5-30%); therefore, it is essential to assess the risk factors related with anthropometry and BMD. To assess the relationship between body mass index (BMI), skeletal composition, waist circumference, tooth loss, fracture risk, BMD of the spine, hip, femur, and mandible in pre and post-menopausal women with periodontitis. We studied 60 women aged 35-60 years, divided in 4 groups (n = 15): premenopausal women without periodontitis; Experimental group 1: premenopausal women with periodontitis; Experimental group 2: postmenopausal women without periodontitis; and Experimental group 3: postmenopausal women with periodontitis. Periodontitis was diagnosed by means of a computerized digital periodontal probe; BMD of the mandible by means of digital radiograph with X ray conversion, the number of teeth by digital panoramic radiograph. We measured: BMI, skeletal composition, waist circumference, risk fracture by the FRAX questionnaire. The variables with a negative correlation with periodontitis were: weight, BMI, and BMD of the mandible with risk fracture (p fracture risk is associated with low weight and BMI and low BMD of the mandible. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  14. Dietary patterns in Canadian men and women ages 25 and older: relationship to demographics, body mass index, and bone mineral density

    Directory of Open Access Journals (Sweden)

    Towheed Tanveer

    2010-01-01

    Full Text Available Abstract Background Previous research has shown that underlying dietary patterns are related to the risk of many different adverse health outcomes, but the relationship of these underlying patterns to skeletal fragility is not well understood. The objective of the study was to determine whether dietary patterns in men (ages 25-49, 50+ and women (pre-menopause, post-menopause are related to femoral neck bone mineral density (BMD independently of other lifestyle variables, and whether this relationship is mediated by body mass index. Methods We performed an analysis of 1928 men and 4611 women participants in the Canadian Multicentre Osteoporosis Study, a randomly selected population-based longitudinal cohort. We determined dietary patterns based on the self-administered food frequency questionnaires in year 2 of the study (1997-99. Our primary outcome was BMD as measured by dual x-ray absorptiometry in year 5 of the study (2000-02. Results We identified two underlying dietary patterns using factor analysis and then derived factor scores. The first factor (nutrient dense was most strongly associated with intake of fruits, vegetables, and whole grains. The second factor (energy dense was most strongly associated with intake of soft drinks, potato chips and French fries, certain meats (hamburger, hot dog, lunch meat, bacon, and sausage, and certain desserts (doughnuts, chocolate, ice cream. The energy dense factor was associated with higher body mass index independent of other demographic and lifestyle factors, and body mass index was a strong independent predictor of BMD. Surprisingly, we did not find a similar positive association between diet and BMD. In fact, when adjusted for body mass index, each standard deviation increase in the energy dense score was associated with a BMD decrease of 0.009 (95% CI: 0.002, 0.016 g/cm2 for men 50+ years old and 0.004 (95% CI: 0.000, 0.008 g/cm2 for postmenopausal women. In contrast, for men 25-49 years old

  15. Radon flux measurement methodologies

    International Nuclear Information System (INIS)

    Nielson, K.K.; Rogers, V.C.

    1984-01-01

    Five methods for measuring radon fluxes are evaluated: the accumulator can, a small charcoal sampler, a large-area charcoal sampler, the ''Big Louie'' charcoal sampler, and the charcoal tent sampler. An experimental comparison of the five flux measurement techniques was also conducted. Excellent agreement was obtained between the measured radon fluxes and fluxes predicted from radium and emanation measurements

  16. Dependence of Core and Extended Flux on Core Dominance ...

    Indian Academy of Sciences (India)

    Abstract. Based on two extragalactic radio source samples, the core dominance parameter is calculated, and the correlations between the core/extended flux density and core dominance parameter are investi- gated. When the core dominance parameter is lower than unity, it is linearly correlated with the core flux density, ...

  17. Inferring CO2 Fluxes from OCO-2 for Assimilation into Land Surface Models to Calculate Net Ecosystem Exchange

    Science.gov (United States)

    Prouty, R.; Radov, A.; Halem, M.; Nearing, G. S.

    2016-12-01

    Investigations of mid to high latitude atmospheric CO2 show a growing seasonal amplitude. Land surface models poorly predict net ecosystem exchange (NEE) and are unable to substantiate these sporadic observations. An investigation of how the biosphere has reacted to changes in atmospheric CO2 is essential to our understanding of potential climate-vegetation feedbacks. A global, seasonal investigation of CO2-flux is then necessary in order to assimilate into land surface models for improving the prediction of annual NEE. The Atmospheric Radiation Measurement program (ARM) of DOE collects CO2-flux measurements (in addition to CO2 concentration and various other meteorological quantities) at several towers located around the globe at half hour temporal frequencies. CO2-fluxes are calculated via the eddy covariance technique, which utilizes CO2-densities and wind velocities to calculate CO2-fluxes. The global coverage of CO2 concentrations as provided by the Orbiting Carbon Observatory (OCO-2) provide satellite-derived CO2 concentrations all over the globe. A framework relating the satellite-inferred CO2 concentrations collocated with the ground-based ARM as well as Ameriflux stations would enable calculations of CO2-fluxes far from the station sites around the entire globe. Regression techniques utilizing deep-learning neural networks may provide such a framework. Additionally, meteorological reanalysis allows for the replacement of the ARM multivariable meteorological variables needed to infer the CO2-fluxes. We present the results of inferring CO2-fluxes from OCO-2 CO2 concentrations for a two year period, Sept. 2014- Sept. 2016 at the ARM station located near Oklahoma City. A feed-forward neural network (FFNN) is used to infer relationships between the following data sets: F([ARM CO2-density], [ARM Meteorological Data]) = [ARM CO2-Flux] F([OCO-2 CO2-density],[ARM Meteorological Data]) = [ARM CO2-Flux] F([ARM CO2-density],[Meteorological Reanalysis]) = [ARM CO2-Flux

  18. Relationship between Bone-Specific Physical Activity Scores and Measures for Body Composition and Bone Mineral Density in Healthy Young College Women.

    Directory of Open Access Journals (Sweden)

    SoJung Kim

    Full Text Available The purpose of this cross-sectional study was to investigate the relationship between bone-specific physical activity (BPAQ scores, body composition, and bone mineral density (BMD in healthy young college women.Seventy-three college women (21.7 ± 1.8 years; 162.1 ± 4.6 cm; 53.9 ± 5.8 kg between the ages of 19 and 26 years were recruited from the universities in Seoul and Gyeonggi province, South Korea. We used dual energy X-ray absorptiometry to measure the lumbar spine (L2-L4 and proximal femur BMD (left side; total hip, femoral neck. The BPAQ scores (past, pBPAQ; current, cBPAQ; total, tBPAQ were used to obtain a comprehensive account of lifetime physical activity related to bone health. We used X-scan plus II instrumentation to measure height (cm, weight (kg, fat free mass (FFM, kg, percent body fat (%, and body mass index (BMI. Participants were asked to record their 24-hour food intake in a questionnaire.There were positive correlations between BPAQ scores and total hip (pBPAQ r = 0.308, p = 0.008; tBPAQ, r = 0.286, p = 0.014 and FN BMD (pBPAQ r = 0.309, p = 0.008; tBPAQ, r = 0.311, p = 0.007, while no significant relationships were found in cBPAQ (p > 0.05. When FFM, Vitamin D intake, cBPAQ, pBPAQ, and tBPAQ were included in a stepwise multiple linear regression analysis, FFM and pBPAQ were predictors of total hip, accounting for 16% (p = 0.024, while FFM and tBPAQ predicted 14% of the variance in FN (p = 0.015. Only FFM predicted 15% of the variance in L2-L4 (p = 0.004. There was a positive correlation between Vitamin D intake and L2-L4 (p = 0.025, but other dietary intakes variables were not significant (p > 0.05.BPAQ-derived physical activity scores and FFM were positively associated with total hip and FN BMD in healthy young college women. Our study suggests that osteoporosis awareness and effective bone healthy behaviors for college women are required to prevent serious bone diseases later in life.

  19. Establishing Reference Intervals for Bone Turnover Markers in the Healthy Shanghai Population and the Relationship with Bone Mineral Density in Postmenopausal Women

    Directory of Open Access Journals (Sweden)

    Wei-Wei Hu

    2013-01-01

    Full Text Available The reference ranges of bone turnover markers (BTMs were important during the treatment of osteoporosis, and the associations with bone mineral density (BMD were controversial. The aim of this study was to establish the reference ranges of N-terminal procollagen of type l collagen (P1NP, osteocalcin (OC, and beta C-terminal cross-linked telopeptides of type I collagen (β-CTX in Shanghai area and to investigate the relationships between BTMs and BMD in postmenopausal women. 2,799 subjects recruited in Shanghai City were measured BTMs to establish the reference ranges. Additional 520 healthy postmenopausal women were also measured BTMs, these women measured BMD in addition. BTMs were measured using the Roche electrochemiluminescence system. We used the age range of 35 to 45-year-olds to calculate reference intervals. The reference range of OC was 4.91 to 13.90 ng/mL for women and 5.58 to 16.57 ng/mL for men, P1NP was 13.72 to 32.90 ng/mL for women and 16.89 to 42.43 ng/mL for men, and β-CTX was 0.112 to 0.210 ng/mL for women and 0.100 to 0.378 ng/mL for men. BTMs significantly negatively correlated with lumbar spine and femoral and total hip in postmenopausal women ( = −0.157 ~ −0.217, P < 0.001. We established the normal reference ranges of P1NP, OC, and β-CTX in the Shanghai area. This study also found that BTMs correlated with BMD and suggested that BTMs were the key determining factors of early BMD decreases.

  20. Evaluation of the relationship of mandibular cortical index and panoramic mandibular index with bone mineral density using panoramic radiography in postmenopausal women: A short study

    Directory of Open Access Journals (Sweden)

    Gargi Saran

    2015-01-01

    Full Text Available Introduction: The problems associated with age-related skeletal osteopenia have received attention since the human skeleton undergoes a continuous physiologic decrease in bone mass with advancing age. Bone status at various sites can be assessed using dual-energy X-ray absorptiometry (DXA or quantitative computed tomography. It would be useful to answer whether radiographic changes in the mandible indicate skeletal osteopenia. Aims and Objectives: The aim and objective of the study was to examine the mandibular cortical index (MCI and panoramic mandibular index (PMI on panoramic radiograph and to establish a relationship between the two indices (MCI and PMI with the bone mineral density (BMD in postmenopausal women. Materials and Methods: The study consisted of 15 postmenopausal women within the age group of 45-75 years. BMD was performed by DXA and measured at the lumbar spine and femoral neck and values were recorded. Panoramic radiographs of the same women were obtained for measuring MCI and PMI. There were two groups taken as C1 and C2 for determination of MCI and PMI. Results: The Pearson correlation analysis revealed a significant correlation between age and T-score (r = −0.59, P < 0.05, i.e., as age increased the T-score decreased. Comparing the T-score of two MCI groups, t-test revealed MCI was 69.1% lower in C2 as compared to C1. The value of P < 0.001 and t-test revealed significantly different and lowered (32.4% inferior cortex level in C2 as compared to C1 (t = 4.76, P < 0.001. Conclusion: Results suggest that in this study panoramic radiography could be a reliable tool in screening for BMD.

  1. Measurements of carbon dioxide and heat fluxes during monsoon ...

    Indian Academy of Sciences (India)

    Using these observations, we explored the diurnal variability of CO2 flux along with sensible and latent heat. The CO2 flux was positive during night-time and negative during daytime and in phase with convective instability. The CO2 flux relationships with the meteorological parameters such as wind speed, temperature and ...

  2. An alternative method for the measurement of neutron flux

    Indian Academy of Sciences (India)

    Abstract. A simple and easy method for measuring the neutron flux is presented. This paper deals with the experimental verification of neutron dose rate–flux relationship for a non-dissipative medium. Though the neutron flux cannot be obtained from the dose rate in a dissipative medium, experimental result shows that for ...

  3. An alternative method for the measurement of neutron flux

    Indian Academy of Sciences (India)

    A simple and easy method for measuring the neutron flux is presented. This paper deals with the experimental verification of neutron dose rate–flux relationship for a non-dissipative medium. Though the neutron flux cannot be obtained from the dose rate in a dissipative medium, experimental result shows that for ...

  4. A model for heliospheric flux-ropes

    Science.gov (United States)

    Nieves-Chinchilla, T.; Linton, M.; Vourlidas, A.; Hidalgo, M. A. U.

    2017-12-01

    This work is presents an analytical flux-rope model, which explores different levels of complexity starting from a circular-cylindrical geometry. The framework of this series of models was established by Nieves-Chinchilla et al. 2016 with the circular-cylindrical analytical flux rope model. The model attempts to describe the magnetic flux rope topology with distorted cross-section as a possible consequence of the interaction with the solar wind. In this model, the flux rope is completely described in a non-orthogonal geometry. The Maxwell equations are solved using tensor calculus consistent with the geometry chosen, invariance along the axial direction, and with the assumption of no radial current density. The model is generalized in terms of the radial and azimuthal dependence of the poloidal current density component and axial current density component. The misalignment between current density and magnetic field is studied in detail for several example profiles of the axial and poloidal current density components. This theoretical analysis provides a map of the force distribution inside of the flux-rope. For reconstruction of the heliospheric flux-ropes, the circular-cylindrical reconstruction technique has been adapted to the new geometry and applied to in situ ICMEs with a flux-rope entrained and tested with cases with clear in situ signatures of distortion. The model adds a piece in the puzzle of the physical-analytical representation of these magnetic structures that should be evaluated with the ultimate goal of reconciling in-situ reconstructions with imaging 3D remote sensing CME reconstructions. Other effects such as axial curvature and/or expansion could be incorporated in the future to fully understand the magnetic structure.

  5. Channel size influence on the heat flux density at zero net mass flow in the non-linear transport regime between 1.2 and 2.1 K

    Science.gov (United States)

    Frederking, T. H. K.; Yuan, S. W. K.; Lee, J. M.; Sun, G. S.

    1987-01-01

    Porous media and narrow ducts of simple shape at zero net mass flow (ZNMF) are used to investigate the influence of pore size on the entropy/heat convection rate at ZNMF. The study is relevant to the development of specific types of phase separators. Previous work on heat transport by convection is extended to porous media without mass loss. The experimental results show the influence of pore size on heat flux for permeabilities between 10 to the -8th and 10 to the -6th sq cm. ZNMF plug data are found to be similar to results obtained for vapor liquid phase separation.

  6. Eddy Correlation Flux Measurement System (ECOR) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, DR

    2011-01-31

    The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.

  7. Comparison of surface energy fluxes with satellite-derived surface energy flux estimates from a shrub-steppe

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, Randy R. [Univ. of Washington, Seattle, WA (United States)

    1993-12-01

    This thesis relates the components of the surface energy balance (i.e., net radiation, sensible and latent heat flux densities, soil heat flow) to remotely sensed data for native vegetation in a semi-arid environment. Thematic mapper data from Landsat 4 and 5 were used to estimate net radiation, sensible heat flux (H), and vegetation amount. Several sources of ground truth were employed. They included soil water balance using the neutron thermalization method and weighing lysimeters, and the measurement of energy fluxes with the Bowen ratio energy balance (BREB) technique. Sensible and latent heat flux were measured at four sites on the U.S. Department of Energy`s Hanford Site using a weighing lysimeter and/or BREB stations. The objective was to calibrate an aerodynamic transport equation that related H to radiant surface temperature. The transport equation was then used with Landsat thermal data to generate estimates of H and compare these estimates against H values obtained with BREB/lysimeters at the time of overflight. Landsat and surface meteorologic data were used to estimate the radiation budget terms at the surface. Landsat estimates of short-wave radiation reflected from the surface correlate well with reflected radiation measured using inverted Eppley pyranometers. Correlation of net radiation estimates determined from satellite data, pyranometer, air temperature, and vapor pressure compared to net radiometer values obtained at time of overflight were excellent for a single image, but decrease for multiple images. Soil heat flux, GT, is a major component of the energy balance in arid systems and G{sub T} generally decreases as vegetation cover increases. Normalized difference vegetation index (NDVI) values generated from Landsat thermatic mapper data were representative of field observations of the presence of green vegetation, but it was not possible to determine a single relationship between NDVI and GT for all sites.

  8. Comparison of surface energy fluxes with satellite-derived surface energy flux estimates from a shrub-steppe

    International Nuclear Information System (INIS)

    Kirkham, R.R.

    1993-12-01

    This thesis relates the components of the surface energy balance (i.e., net radiation, sensible and latent heat flux densities, soil heat flow) to remotely sensed data for native vegetation in a semi-arid environment. Thematic mapper data from Landsat 4 and 5 were used to estimate net radiation, sensible heat flux (H), and vegetation amount. Several sources of ground truth were employed. They included soil water balance using the neutron thermalization method and weighing lysimeters, and the measurement of energy fluxes with the Bowen ratio energy balance (BREB) technique. Sensible and latent heat flux were measured at four sites on the U.S. Department of Energy's Hanford Site using a weighing lysimeter and/or BREB stations. The objective was to calibrate an aerodynamic transport equation that related H to radiant surface temperature. The transport equation was then used with Landsat thermal data to generate estimates of H and compare these estimates against H values obtained with BREB/lysimeters at the time of overflight. Landsat and surface meteorologic data were used to estimate the radiation budget terms at the surface. Landsat estimates of short-wave radiation reflected from the surface correlate well with reflected radiation measured using inverted Eppley pyranometers. Correlation of net radiation estimates determined from satellite data, pyranometer, air temperature, and vapor pressure compared to net radiometer values obtained at time of overflight were excellent for a single image, but decrease for multiple images. Soil heat flux, G T , is a major component of the energy balance in arid systems and G T generally decreases as vegetation cover increases. Normalized difference vegetation index (NDVI) values generated from Landsat thermatic mapper data were representative of field observations of the presence of green vegetation, but it was not possible to determine a single relationship between NDVI and G T for all sites

  9. Clustering of Emerging Flux

    Science.gov (United States)

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  10. Population density, biomass and allometric relationship of shortneck clam Paphia malabarica (Chemnitz, 1782) from estuarine regions of Goa west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Nagvenkar, S.S.; Ansari, Z.A.; Jagtap, T.G.

    Studies on morphometry and length-weight relationship of Paphia malabarica were carried out in samples collected during March 2009 to March 2010 at two locations in Goa. Morphometric relationships between length-breadth and length-depth variables...

  11. Black branes in flux compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Torroba, Gonzalo; Wang, Huajia

    2013-10-01

    We construct charged black branes in type IIA flux compactifications that are dual to (2 + 1)-dimensional field theories at finite density. The internal space is a general Calabi-Yau manifold with fluxes, with internal dimensions much smaller than the AdS radius. Gauge fields descend from the 3-form RR potential evaluated on harmonic forms of the Calabi-Yau, and Kaluza-Klein modes decouple. Black branes are described by a four-dimensional effective field theory that includes only a few light fields and is valid over a parametrically large range of scales. This effective theory determines the low energy dynamics, stability and thermodynamic properties. Tools from flux compactifications are also used to construct holographic CFTs with no relevant scalar operators, that can lead to symmetric phases of condensed matter systems stable to very low temperatures. The general formalism is illustrated with simple examples such as toroidal compactifications and manifolds with a single size modulus. We initiate the classification of holographic phases of matter described by flux compactifications, which include generalized Reissner-Nordstrom branes, nonsupersymmetric AdS2×R2 and hyperscaling violating solutions.

  12. The relationship between local liquid density and force applied on a tip of atomic force microscope: a theoretical analysis for simple liquids.

    Science.gov (United States)

    Amano, Ken-ichi; Suzuki, Kazuhiro; Fukuma, Takeshi; Takahashi, Ohgi; Onishi, Hiroshi

    2013-12-14

    The density of a liquid is not uniform when placed on a solid. The structured liquid pushes or pulls a probe employed in atomic force microscopy, as demonstrated in a number of experimental studies. In the present study, the relation between the force on a probe and the local density of a liquid is derived based on the statistical mechanics of simple liquids. When the probe is identical to a solvent molecule, the strength of the force is shown to be proportional to the vertical gradient of ln(ρDS) with the local liquid's density on a solid surface being ρDS. The intrinsic liquid's density on a solid is numerically calculated and compared with the density reconstructed from the force on a probe that is identical or not identical to the solvent molecule.

  13. The relationship between local liquid density and force applied on a tip of atomic force microscope: A theoretical analysis for simple liquids

    International Nuclear Information System (INIS)

    Amano, Ken-ichi; Takahashi, Ohgi; Suzuki, Kazuhiro; Fukuma, Takeshi; Onishi, Hiroshi

    2013-01-01

    The density of a liquid is not uniform when placed on a solid. The structured liquid pushes or pulls a probe employed in atomic force microscopy, as demonstrated in a number of experimental studies. In the present study, the relation between the force on a probe and the local density of a liquid is derived based on the statistical mechanics of simple liquids. When the probe is identical to a solvent molecule, the strength of the force is shown to be proportional to the vertical gradient of ln(ρ DS ) with the local liquid's density on a solid surface being ρ DS . The intrinsic liquid's density on a solid is numerically calculated and compared with the density reconstructed from the force on a probe that is identical or not identical to the solvent molecule

  14. Investigating relationships between the air temperature urban heat island effect and land use characteristics in the Los Angeles basin using high density observations and mobile transects

    Science.gov (United States)

    Mohegh, M.; Taha, H.; Levinson, R.; Ban-Weiss, G. A.

    2017-12-01

    The urban heat island effect (UHI) is defined as urban areas having higher temperatures than their surrounding rural areas and is caused by variations in land-cover characteristics. Most past research on UHI attribution has focused on using satellite-sensor derived temperatures to detect and define the UHI. However, satellite sensors can detect only surface temperatures and not air temperatures, which requires high-resolution ground-based measurements. In this study, we investigate the contributions of land-cover characteristics on determining neighborhood-scale UHIs during day and night in two parts of the Los Angeles basin. The two regions of focus, the San Fernando Valley (SFV) and downtown Los Angeles (DLA), were selected due to their differing baseline climates and variations in land-cover properties. Two sources of air temperature measurements were used: high-density personal weather stations, and mobile transects. Land use characteristics including impervious fraction, building height, vegetation fraction, land-use type, and albedo, were spatially averaged in surrounding areas of each measurement location. Statistical approaches were then used to determine the influence of the aforementioned land-cover characteristics and the extent of spatial averaging on land-cover - temperature interactions. The results suggest that the driving mechanisms that dictate the neighborhood-scale urban heat islands differ between SFV and DLA. During the day, impervious fraction has positive correlation with air temperature in both regions, likely due to increases in heat capacity causing reductions in the diurnal temperature range (DTR). Increased building heights tended to increase temperatures in SFV but decrease temperatures in DLA. This is likely due to the competition between impacts of building height on shortwave radiative transfer (i.e. shading), longwave radiative transfer escaping the urban canopy, and surface roughness. During night, correlations between air

  15. Heat flux viscosity in collisional magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C., E-mail: cliu@pppl.gov [Princeton University, Princeton, New Jersey 08544 (United States); Fox, W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Bhattacharjee, A. [Princeton University, Princeton, New Jersey 08544 (United States); Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2015-05-15

    Momentum transport in collisional magnetized plasmas due to gradients in the heat flux, a “heat flux viscosity,” is demonstrated. Even though no net particle flux is associated with a heat flux, in a plasma there can still be momentum transport owing to the velocity dependence of the Coulomb collision frequency, analogous to the thermal force. This heat-flux viscosity may play an important role in numerous plasma environments, in particular, in strongly driven high-energy-density plasma, where strong heat flux can dominate over ordinary plasma flows. The heat flux viscosity can influence the dynamics of the magnetic field in plasmas through the generalized Ohm's law and may therefore play an important role as a dissipation mechanism allowing magnetic field line reconnection. The heat flux viscosity is calculated directly using the finite-difference method of Epperlein and Haines [Phys. Fluids 29, 1029 (1986)], which is shown to be more accurate than Braginskii's method [S. I. Braginskii, Rev. Plasma Phys. 1, 205 (1965)], and confirmed with one-dimensional collisional particle-in-cell simulations. The resulting transport coefficients are tabulated for ease of application.

  16. Enhanced Flux Pinning and Critical Current Density via Incorporation of Self-Assembled Rare-Earth Barium Tantalate Nanocolumns within YBa2Cu3O7-δ Films

    Energy Technology Data Exchange (ETDEWEB)

    Wee, Sung Hun [ORNL; Goyal, Amit [ORNL; Specht, Eliot D [ORNL; Cantoni, Claudia [ORNL; Zuev, Yuri L [ORNL; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York; Cook, Sylvester W [ORNL

    2010-01-01

    We report rare earth barium tantalates, Ba2RETaO6 (BRETO, RE = rare earth elements) as a new class of additives for superior flux-pinning in YBa2Cu3O7- (YBCO) films. BRETO compounds have excellent chemical inertness to and large lattice mismatch with YBCO. This results in phase separation and strain minimization driven self-assembly of BRETO nanocolumns within YBCO films. YBCO+4 vol% Ba2GdTaO6 films show similar Tc to that of an un-doped film of ~ 88.3 K, a higher self-field Jc of 3.8 MA/cm2 at 77 K, and significantly improved in-field Jc higher by a factor of 1.5-6 over entire magnetic field and angular ranges.

  17. Materials for efficient high-flux magnetic bearing actuators

    Science.gov (United States)

    Williams, M. E.; Trumper, D. L.

    1994-01-01

    Magnetic bearings have demonstrated the capability for achieving positioning accuracies at the nanometer level in precision motion control stages. This makes possible the positioning of a wafer in six degrees of freedom with the precision necessary for photolithography. To control the position of an object at the nanometer level, a model of the magnetic bearing actuator force-current-airgap relationship must be accurately obtained. Additionally, to reduce thermal effects the design of the actuator should be optimized to achieve maximum power efficiency and flux density. Optimization of the actuator is accomplished by proper pole face sizing and utilizing a magnetic core material which can be magnetized to the highest flux density with low magnetic loss properties. This paper describes the construction of a magnetic bearing calibration fixture designed for experimental measurement of the actuator force characteristics. The results of a material study that review the force properties of nickel-steel, silicon-steel, and cobalt-vanadium-iron, as they apply to magnetic bearing applications are also presented.

  18. Comparison between elementary flux modes analysis and 13C-metabolic fluxes measured in bacterial and plant cells.

    Science.gov (United States)

    Beurton-Aimar, Marie; Beauvoit, Bertrand; Monier, Antoine; Vallée, François; Dieuaide-Noubhani, Martine; Colombié, Sophie

    2011-06-20

    (13)C metabolic flux analysis is one of the pertinent ways to compare two or more physiological states. From a more theoretical standpoint, the structural properties of metabolic networks can be analysed to explore feasible metabolic behaviours and to define the boundaries of steady state flux distributions. Elementary flux mode analysis is one of the most efficient methods for performing this analysis. In this context, recent approaches have tended to compare experimental flux measurements with topological network analysis. Metabolic networks describing the main pathways of central carbon metabolism were set up for a bacteria species (Corynebacterium glutamicum) and a plant species (Brassica napus) for which experimental flux maps were available. The structural properties of each network were then studied using the concept of elementary flux modes. To do this, coefficients of flux efficiency were calculated for each reaction within the networks by using selected sets of elementary flux modes. Then the relative differences - reflecting the change of substrate i.e. a sugar source for C. glutamicum and a nitrogen source for B. napus - of both flux efficiency and flux measured experimentally were compared. For both organisms, there is a clear relationship between these parameters, thus indicating that the network structure described by the elementary flux modes had captured a significant part of the metabolic activity in both biological systems. In B. napus, the extension of the elementary flux mode analysis to an enlarged metabolic network still resulted in a clear relationship between the change in the coefficients and that of the measured fluxes. Nevertheless, the limitations of the method to fit some particular fluxes are discussed. This consistency between EFM analysis and experimental flux measurements, validated on two metabolic systems allows us to conclude that elementary flux mode analysis could be a useful tool to complement (13)C metabolic flux analysis

  19. Effect of planting density on root lodging resistance and its relationship to nodal root growth characteristics in maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Liu, Shengqun; Song, Fengbin; Liu, Fulai

    2012-01-01

    , an indicator of root lodging resistance, was significantly affected by the planting density, the maize variety, as well as the crop developmental stages, and was decreased with increasing planting density. The number and the average diameter of the roots on the upper internodes (phytomer 5 to 8) were decreased...... correlated with the total root number and the average root diameter on the upper internodes, indicating that a greater root number and a larger root diameter are important traits for enhancing root lodging resistance in maize plants.......Increase of planting density has been widely used to increase grain yield in maize. However, it may lead to higher risk of root lodging hence causing significant yield loss of the crop. The objective of this study was to investigate the effect of planting density on maize nodal root growth...

  20. Relationships between population density, fine-scale genetic structure, mating system and pollen dispersal in a timber tree from African rainforests.

    Science.gov (United States)

    Duminil, J; Daïnou, K; Kaviriri, D K; Gillet, P; Loo, J; Doucet, J-L; Hardy, O J

    2016-03-01

    Owing to the reduction of population density and/or the environmental changes it induces, selective logging could affect the demography, reproductive biology and evolutionary potential of forest trees. This is particularly relevant in tropical forests where natural population densities can be low and isolated trees may be subject to outcross pollen limitation and/or produce low-quality selfed seeds that exhibit inbreeding depression. Comparing reproductive biology processes and genetic diversity of populations at different densities can provide indirect evidence of the potential impacts of logging. Here, we analysed patterns of genetic diversity, mating system and gene flow in three Central African populations of the self-compatible legume timber species Erythrophleum suaveolens with contrasting densities (0.11, 0.68 and 1.72 adults per ha). The comparison of inbreeding levels among cohorts suggests that selfing is detrimental as inbred individuals are eliminated between seedling and adult stages. Levels of genetic diversity, selfing rates (∼16%) and patterns of spatial genetic structure (Sp ∼0.006) were similar in all three populations. However, the extent of gene dispersal differed markedly among populations: the average distance of pollen dispersal increased with decreasing density (from 200 m in the high-density population to 1000 m in the low-density one). Overall, our results suggest that the reproductive biology and genetic diversity of the species are not affected by current logging practices. However, further investigations need to be conducted in low-density populations to evaluate (1) whether pollen limitation may reduce seed production and (2) the regeneration potential of the species.

  1. The flux of radon and thoron from Australian soils

    International Nuclear Information System (INIS)

    Schery, S.D.; Whittlestone, S.; Hart, K.P.; Hill, S.E.

    1989-01-01

    The accumulator technique was used to measure radon and thoron flux density at a variety of locations throughout Australia. This is the first such systematic study of Australia and, in the case of thoron, one of few such studies of any large land mass. Seasonally adjusted arithmetic mean flux densities from Australian soils were estimated to be 22 mBq m -2 1.05 atom cm -2 s -1 s -1 for radon and 1.7 Bq m -2 s -1 (0.0135 atom cm -2 s -1 ) for thoron. Considerations of statistical sampling error, and systematic error with the accumulator method, leads to an error estimate of about ±20% for these numbers; projection of total flux to the atmosphere requires consideration of additional sources of error. Only modest correlations with variables easily measured in the field were observed. The strongest correlation was a positive one between flux density and gamma dose rate 1 m above ground. Weaker correlations were seen with soil temperature (positive) and soil mositure (negative at higher moistures). Radon and thoron flux density were strongly correlated, but only a weak correlation (negative) existed between them and vegetation. The amount of radon isotope released to the pore space seems particularly important for controlling the wide variation in observed flux densities, but it remains difficult to predict flux densities based on simple field measurements or information in conventional soil and geological maps. copyright American Geophysical Union 1989

  2. Doping dependence of the upper critical field, superconducting current density and thermally activated flux flow activation energy in polycrystalline CeFeAsO1-xFx superconductors

    Science.gov (United States)

    Chong, S. V.; Williams, G. V. M.; Sambale, S.; Kadowaki, K.

    2014-12-01

    We report the results from resistivity and magnetic measurements on polycrystalline Ce oxypnictide (CeFeAsO1-xFx) samples where x spans from 0.13 to 0.25. We find that the orbital limiting field is as high as 150 T and it systematically decreases with increasing doping. The Maki parameter is greater than one across the phase diagram and the large Maki parameter suggests that orbital and Pauli limiting effects contribute to the upper critical field. The broadening of the superconducting transition in the resistivity data was interpreted using the thermally activated flux flow (TAFF) model where we find that the TAFF activation energy, U0(B), is proportional to B-γ from 1 T to high fields, and γ does not significantly change with doping. However, U0 and the superconducting critical current, Jc, are peaked in the mid-doping region (x = 0.15-0.20), and not in the low (x 0.20) regions. Furthermore, U0 is correlated with Jc and follows the two fluid model for granular samples.

  3. Characterization of methane-hydrate formation inferred from insitu Vp-density relationship for hydrate-bearing sediment cores obtained off the eastern coast of India

    Science.gov (United States)

    Kinoshita, M.; Hamada, Y.; Hirose, T.; Yamada, Y.

    2017-12-01

    In 2015, the Indian National Gas Hydrate Program (NGHP) Drilling Expedition 02 was carried out off the eastern margin of the Indian Peninsula in order to investigate distribution and occurrence of gas hydrates. From 25 drill sites, downhole logging data, cored samples, and drilling performance data were collected. One of the target areas (area B) is located on the axial and flank of an anticline, where the BSR is identified 100 m beneath the summit of anticline. 3 sites were drilled in the crest. The lower potential hydrate zone II was suggested by downhole logging (LWD) at 270-290 m below seafloor across the top of anticline. Core samples from this interval is characterized by a higher natural gamma radiation, gamma-ray-based higher bulk density and lower porosity, and higher electrical resistivity. All these features are in good agreement with LWD results. During this expedition, numerous special core sampling operations (PCAT) were carried out, keeping its insitu pressure in a pressure-tight vessel. They enabled acquiring insitu P-wave velocity and gamma-ray attenuation density measurements. In-situ X-CT images exhibit very clear hydrate distribution as lower density patches. Hydrate-bearing sediments exhibit a Vp-density trend that is clearly different from the ordinary formation. Vp values are significantly higher than 2 km/s whereas the density remains constant at 2-2.2 g/cm3 in hydrate zones. At some hydrate-bearing sediments, we noticed that Vp is negatively correlated to the density in the deeper portion (235-285 mbsf). On the other hand, in the shallower portion they are positively correlated. From lithostratigraphy the shallower portion consists of sand, whereas deeper portion are silty-clay dominant. We infer that the sand-dominant, shallower hydrate is a pore-filling type, and Vp is correlated positively to density. On the other hand, the clay-dominant, deeper hydrate is filled in vertical veins, and Vp is negatively correlated to density. Negative

  4. Modelling drug flux through microporated skin.

    Science.gov (United States)

    Rzhevskiy, Alexey S; Guy, Richard H; Anissimov, Yuri G

    2016-11-10

    A simple mathematical equation has been developed to predict drug flux through microporated skin. The theoretical model is based on an approach applied previously to water evaporation through leaf stomata. Pore density, pore radius and drug molecular weight are key model parameters. The predictions of the model were compared with results derived from a simple, intuitive method using porated area alone to estimate the flux enhancement. It is shown that the new approach predicts significantly higher fluxes than the intuitive analysis, with transport being proportional to the total pore perimeter rather than area as intuitively anticipated. Predicted fluxes were in good general agreement with experimental data on drug delivery from the literature, and were quantitatively closer to the measured values than those derived from the intuitive, area-based approach. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Characterization of ion fluxes and heat fluxes for PMI relevant conditions on Proto-MPEX

    Science.gov (United States)

    Beers, Clyde; Shaw, Guinevere; Biewer, Theodore; Rapp, Juergen

    2016-10-01

    Plasma characterization, in particular, particle flux and electron and ion temperature distributions nearest to an exposed target, are critical to quantifying Plasma Surface Interaction (PSI). In the Proto-Material Plasma Exposure eXperiment (Proto-MPEX), the ion fluxes and heat fluxes are derived from double Langmuir Probes (DLP) and Thomson Scattering in front of the target assuming Bohm conditions at the sheath entrance. Power fluxes derived from ne and Te measurements are compared to heat fluxes measured with IR thermography. The comparison will allow conclusions on the sheath heat transmission coefficient to be made experimentally. Different experimental conditions (low and high density plasmas (0.5 - 6 x 1019 m-3) with different magnetic configuration are compared. This work was supported by the U.S. D.O.E. contract DE-AC05-00OR22725.

  6. Compact neutron flux monitor

    International Nuclear Information System (INIS)

    Madhavi, V.; Phatak, P.R.; Bahadur, C.; Bayala, A.K.; Jakati, R.K.; Sathian, V.

    2003-01-01

    Full text: A compact size neutron flux monitor has been developed incorporating standard boards developed for smart radiation monitors. The sensitivity of the monitors is 0.4cps/nV. It has been tested up to 2075 nV flux with standard neutron sources. It shows convincing results even in high flux areas like 6m away from the accelerator in RMC (Parel) for 106/107 nV. These monitors have a focal and remote display, alarm function with potential free contacts for centralized control and additional provision of connectivity via RS485/Ethernet. This paper describes the construction, working and results of the above flux monitor

  7. Crystal growth of emerald by flux method

    International Nuclear Information System (INIS)

    Inoue, Mikio; Narita, Eiichi; Okabe, Taijiro; Morishita, Toshihiko.

    1979-01-01

    Emerald crystals have been formed in two binary fluxes of Li 2 O-MoO 2 and Li 2 O-V 2 O 5 using the slow cooling method and the temperature gradient method under various conditions. In the flux of Li 2 O-MoO 3 carried out in the range of 2 -- 5 of molar ratios (MoO 3 /Li 2 O), emerald was crystallized in the temperature range from 750 to 950 0 C, and the suitable crystallization conditions were found to be the molar ratio of 3 -- 4 and the temperature about 900 0 C. In the flux of Li 2 O-V 2 O 5 carried out in the range of 1.7 -- 5 of molar ratios (V 2 O 5 /Li 2 O), emerald was crystallized in the temperature range from 900 to 1150 0 . The suitable crystals were obtained at the molar ratio of 3 and the temperature range of 1000 -- 1100 0 C. The crystallization temperature rised with an increase in the molar ratio of the both fluxes. The emeralds grown in two binary fluxes were transparent green, having the density of 2.68, the refractive index of 1.56, and the two distinct bands in the visible spectrum at 430 and 600nm. The emerald grown in Li 2 O-V 2 O 5 flux was more bluish green than that grown in Li 2 O-MoO 3 flux. The size of the spontaneously nucleated emerald grown in the former flux was larger than the latter, when crystallized by the slow cooling method. As for the solubility of beryl in the two fluxes, Li 2 O-V 2 O 5 flux was superior to Li 2 O-MoO 3 flux whose small solubility of SiO 2 caused an experimental problem to the temperature gradient method. The suitability of the two fluxes for the crystal growth of emerald by the flux method was discussed from the view point of various properties of above-mentioned two fluxes. (author)

  8. Curl flux, coherence, and population landscape of molecular systems: Nonequilibrium quantum steady state, energy (charge) transport, and thermodynamics

    International Nuclear Information System (INIS)

    Zhang, Z. D.; Wang, J.

    2014-01-01

    We established a theoretical framework in terms of the curl flux, population landscape, and coherence for non-equilibrium quantum systems at steady state, through exploring the energy and charge transport in molecular processes. The curl quantum flux plays the key role in determining transport properties and the system reaches equilibrium when flux vanishes. The novel curl quantum flux reflects the degree of non-equilibriumness and the time-irreversibility. We found an analytical expression for the quantum flux and its relationship to the environmental pumping (non-equilibriumness quantified by the voltage away from the equilibrium) and the quantum tunneling. Furthermore, we investigated another quantum signature, the coherence, quantitatively measured by the non-zero off diagonal element of the density matrix. Populations of states give the probabilities of individual states and therefore quantify the population landscape. Both curl flux and coherence depend on steady state population landscape. Besides the environment-assistance which can give dramatic enhancement of coherence and quantum flux with high voltage at a fixed tunneling strength, the quantum flux is promoted by the coherence in the regime of small tunneling while reduced by the coherence in the regime of large tunneling, due to the non-monotonic relationship between the coherence and tunneling. This is in contrast to the previously found linear relationship. For the systems coupled to bosonic (photonic and phononic) reservoirs the flux is significantly promoted at large voltage while for fermionic (electronic) reservoirs the flux reaches a saturation after a significant enhancement at large voltage due to the Pauli exclusion principle. In view of the system as a quantum heat engine, we studied the non-equilibrium thermodynamics and established the analytical connections of curl quantum flux to the transport quantities such as energy (charge) transfer efficiency, chemical reaction efficiency, energy

  9. Regional absolute conductivity reconstruction using projected current density in MREIT

    International Nuclear Information System (INIS)

    Sajib, Saurav Z K; Kim, Hyung Joong; Woo, Eung Je; Kwon, Oh In

    2012-01-01

    Magnetic resonance electrical impedance tomography (MREIT) is a non-invasive technique for imaging the internal conductivity distribution in tissue within an MRI scanner, utilizing the magnetic flux density, which is introduced when a current is injected into the tissue from external electrodes. This magnetic flux alters the MRI signal, so that appropriate reconstruction can provide a map of the additional z-component of the magnetic field (B z ) as well as the internal current density distribution that created it. To extract the internal electrical properties of the subject, including the conductivity and/or the current density distribution, MREIT techniques use the relationship between the external injection current and the z-component of the magnetic flux density B = (B x , B y , B z ). The tissue studied typically contains defective regions, regions with a low MRI signal and/or low MRI signal-to-noise-ratio, due to the low density of nuclear magnetic resonance spins, short T 2 or T* 2 relaxation times, as well as regions with very low electrical conductivity, through which very little current traverses. These defective regions provide noisy B z data, which can severely degrade the overall reconstructed conductivity distribution. Injecting two independent currents through surface electrodes, this paper proposes a new direct method to reconstruct a regional absolute isotropic conductivity distribution in a region of interest (ROI) while avoiding the defective regions. First, the proposed method reconstructs the contrast of conductivity using the transversal J-substitution algorithm, which blocks the propagation of severe accumulated noise from the defective region to the ROI. Second, the proposed method reconstructs the regional projected current density using the relationships between the internal current density, which stems from a current injection on the surface, and the measured B z data. Combining the contrast conductivity distribution in the entire imaging

  10. Relationships between seismic wave-Speed, density, and electrical conductivity beneath Australia from seismology, mineralogy, and laboratory-based conductivity profiles

    DEFF Research Database (Denmark)

    Khan, A.; Koch, S.; Shankland, T. J.

    2015-01-01

    We present maps of the three-dimensional density (ρ), electrical conductivity (σ), and shear-wave speed (VS) structure of the mantle beneath Australia and surrounding ocean in the depth range of 100–800 km. These maps derived from stochastic inversion of seismic surface-wave dispersion data, ther...

  11. Controlling for high-density lipoprotein cholesterol does not affect the magnitude of the relationship between alcohol and coronary heart disease.

    Science.gov (United States)

    Magnus, Per; Bakke, Eirin; Hoff, Dominic A; Høiseth, Gudrun; Graff-Iversen, Sidsel; Knudsen, Gun Peggy; Myhre, Ronny; Normann, Per Trygve; Næss, Øyvind; Tambs, Kristian; Thelle, Dag S; Mørland, Jørg

    2011-11-22

    This study tested the hypothesis that moderate alcohol intake exerts its cardioprotective effect mainly through an increase in the serum level of high-density lipoprotein cholesterol. In the Cohort of Norway (CONOR) study, 149 729 adult participants, recruited from 1994 to 2003, were followed by linkage to the Cause of Death Registry until 2006. At recruitment, questionnaire data on alcohol intake were collected, and the concentration of high-density lipoprotein cholesterol in serum was measured. Using Cox regression, we found that the adjusted hazard ratio for men for dying from coronary heart disease was 0.52 (95% confidence interval, 0.39-0.69) when consuming alcohol more than once a week compared with never or rarely. The ratio changed only slightly, to 0.55 (0.41-0.73), after the regression model included the serum level of high-density cholesterol. For women, the corresponding hazard ratios were 0.62 (0.32-1.23) and 0.68 (0.34-1.34), respectively. Alcohol intake is related to a reduced risk of death from coronary heart disease in the follow-up of a large, population-based Norwegian cohort study with extensive control for confounding factors. Our findings suggest that the serum level of high-density cholesterol is not an important intermediate variable in the possible causal pathway between moderate alcohol intake and coronary heart disease.

  12. An ecology of prestige in New York City: Examining the relationships among population density, socio-economic status, group identity, and residential canopy cover

    Science.gov (United States)

    J. Morgan Grove; Dexter H. Locke; Jarlath P.M. O' Neil-Dunne

    2014-01-01

    Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use...

  13. Road density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  14. Video Meteor Fluxes

    Science.gov (United States)

    Campbell-Brown, M. D.; Braid, D.

    2011-01-01

    The flux of meteoroids, or number of meteoroids per unit area per unit time, is critical for calibrating models of meteoroid stream formation and for estimating the hazard to spacecraft from shower and sporadic meteors. Although observations of meteors in the millimetre to centimetre size range are common, flux measurements (particularly for sporadic meteors, which make up the majority of meteoroid flux) are less so. It is necessary to know the collecting area and collection time for a given set of observations, and to correct for observing biases and the sensitivity of the system. Previous measurements of sporadic fluxes are summarized in Figure 1; the values are given as a total number of meteoroids striking the earth in one year to a given limiting mass. The Gr n et al. (1985) flux model is included in the figure for reference. Fluxes for sporadic meteoroids impacting the Earth have been calculated for objects in the centimeter size range using Super-Schmidt observations (Hawkins & Upton, 1958); this study used about 300 meteors, and used only the physical area of overlap of the cameras at 90 km to calculate the flux, corrected for angular speed of meteors, since a large angular speed reduces the maximum brightness of the meteor on the film, and radiant elevation, which takes into account the geometric reduction in flux when the meteors are not perpendicular to the horizontal. They bring up corrections for both partial trails (which tends to increase the collecting area) and incomplete overlap at heights other than 90 km (which tends to decrease it) as effects that will affect the flux, but estimated that the two effects cancelled one another. Halliday et al. (1984) calculated the flux of meteorite-dropping fireballs with fragment masses greater than 50 g, over the physical area of sky accessible to the MORP fireball cameras, counting only observations in clear weather. In the micron size range, LDEF measurements of small craters on spacecraft have been used to

  15. The measurements of thermal neutron flux distribution in a paraffin ...

    Indian Academy of Sciences (India)

    neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of indium foils with two different detectors (Geiger–. Muller counter and NaI(Tl)) was the aim of this project. The relative differences of the outcome of the experiments were between ...

  16. Dependence of Core and Extended Flux on Core Dominance ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Based on two extragalactic radio source samples, the core dominance parameter is calculated, and the correlations between the core/extended flux density and core dominance parameter are investigated. When the core dominance parameter is lower than unity, it is linearly correlated with the core flux ...

  17. Estimating daytime ecosystem respiration from eddy-flux data

    DEFF Research Database (Denmark)

    Bruhn, Dan; Mikkelsen, Teis Nørgaard; Herbst, Mathias

    2011-01-01

    based on whole ecosystem fluxes from a linear regression of photosynthetic photon flux density data vs. daytime net ecosystem exchange data at forest ecosystem level. This method is based on the principles of the Kok-method applied at leaf level for estimating daytime respiration. We demonstrate...

  18. The measurements of thermal neutron flux distribution in a paraffin ...

    Indian Academy of Sciences (India)

    at 293.4 K. In order to measure the thermal neutron flux density, the foil activation method was used. Thermal neutron flux determination in paraffin phantom by counting the emitted rays of indium foils with two different detectors (Geiger–. Muller counter and NaI(Tl)) was the aim of this project. The relative differences of the ...

  19. Direct relationship between cell density and FDG uptake in asymptomatic aortic aneurysm close to surgical threshold: an in vivo and in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Marini, Cecilia [CNR Institute of Bioimaging and Molecular Physiology, Milan, Genoa Section, Genoa (Italy); Oftalmologia e Genetica dell' Universita di Genova, Dipartimento di Neuroscienze, Genoa (Italy); Morbelli, Silvia; Armonino, Riccardo; Riondato, Mattia; Massollo, Michela; Augeri, Carla; Fiz, Francesco; Sambuceti, Gianmario [University of Genoa, Department Internal Medicine, Chair of Nuclear Medicine, Genoa (Italy); Spinella, Giovanni; Pane, Bianca; Palmieri, Daniela; Palombo, Domenico [San Martino University Hospital, University of Genoa, Division of Vascular and Endovascular Surgery, Genoa (Italy); Sarocchi, Francesca; Abete, Luca; Fulcheri, Ezio [University of Genoa, Department of Surgical and Diagnostic Sciences, Pathology, Genoa (Italy); Ghigliotti, Giorgio [University of Genoa, Department of Internal Medicine, Chair of Cardiology, Genoa (Italy); Cittadini, Giuseppe [Hospital San Martino, Department of Radiology, Genoa (Italy)

    2012-01-15

    Conflicting results have been reported about the clinical value of fluorodeoxyglucose (FDG) imaging in predicting the risk of rupture of abdominal aortic aneurysm (AAA). The present study tests the hypothesis that FDG uptake is low in asymptomatic noninflammatory AAA due to the low cell density in aneurysmal walls. Positron emission tomography (PET)/CT imaging was performed in 12 consecutive candidates for AAA surgical repair and in 12 age- and sex-matched controls. At intervention, aneurysmal walls were cut into three sequential blocks. Block A was frozen to cut three 5-{mu}m slices for incubation with 2-3 MBq of FDG for 5 min. Block C was first incubated with the same tracer solution for the same time and subsequently frozen to cut three 5-{mu}m slices. Autoradiographic images were coregistered with immunohistochemical pictures of cell density, type and DNA synthesis as assessed on block B. No visible uptake in abdominal aorta occurred in any patient or control subject. Immunohistochemistry documented a severe loss of wall structure, with low numbers of cells. Tracer retention directly correlated with overall cell density and with prevalence of cells synthesizing DNA. The metabolic nature of FDG uptake was confirmed by the selective effect of preliminary freezing that decreased tracer content by 90% in regions with high cell density and only by 34% in cold acellular areas. The loss of tissue structure and the marked decrease in cell density account for the low prevalence of positive findings at FDG PET imaging, at least in asymptomatic patients bearing AAAs whose diameter is close to surgical indication. (orig.)

  20. Direct relationship between cell density and FDG uptake in asymptomatic aortic aneurysm close to surgical threshold: an in vivo and in vitro study

    International Nuclear Information System (INIS)

    Marini, Cecilia; Morbelli, Silvia; Armonino, Riccardo; Riondato, Mattia; Massollo, Michela; Augeri, Carla; Fiz, Francesco; Sambuceti, Gianmario; Spinella, Giovanni; Pane, Bianca; Palmieri, Daniela; Palombo, Domenico; Sarocchi, Francesca; Abete, Luca; Fulcheri, Ezio; Ghigliotti, Giorgio; Cittadini, Giuseppe

    2012-01-01

    Conflicting results have been reported about the clinical value of fluorodeoxyglucose (FDG) imaging in predicting the risk of rupture of abdominal aortic aneurysm (AAA). The present study tests the hypothesis that FDG uptake is low in asymptomatic noninflammatory AAA due to the low cell density in aneurysmal walls. Positron emission tomography (PET)/CT imaging was performed in 12 consecutive candidates for AAA surgical repair and in 12 age- and sex-matched controls. At intervention, aneurysmal walls were cut into three sequential blocks. Block A was frozen to cut three 5-μm slices for incubation with 2-3 MBq of FDG for 5 min. Block C was first incubated with the same tracer solution for the same time and subsequently frozen to cut three 5-μm slices. Autoradiographic images were coregistered with immunohistochemical pictures of cell density, type and DNA synthesis as assessed on block B. No visible uptake in abdominal aorta occurred in any patient or control subject. Immunohistochemistry documented a severe loss of wall structure, with low numbers of cells. Tracer retention directly correlated with overall cell density and with prevalence of cells synthesizing DNA. The metabolic nature of FDG uptake was confirmed by the selective effect of preliminary freezing that decreased tracer content by 90% in regions with high cell density and only by 34% in cold acellular areas. The loss of tissue structure and the marked decrease in cell density account for the low prevalence of positive findings at FDG PET imaging, at least in asymptomatic patients bearing AAAs whose diameter is close to surgical indication. (orig.)

  1. Lung density

    DEFF Research Database (Denmark)

    Garnett, E S; Webber, C E; Coates, G

    1977-01-01

    The density of a defined volume of the human lung can be measured in vivo by a new noninvasive technique. A beam of gamma-rays is directed at the lung and, by measuring the scattered gamma-rays, lung density is calculated. The density in the lower lobe of the right lung in normal man during quiet...

  2. Solar Magnetic Flux Ropes

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fill the whole volume of a dark coronal cavity. The flux ropes can be in stable equilibrium in the coronal magnetic field for weeks and even months, but suddenly they lose their stability and erupt with ...

  3. Assessment of Vegetation Density and Soil Macrofauna Relationship in Riparian Forest of Karkhe River for the Determination of Rivers Buffer Zone

    Directory of Open Access Journals (Sweden)

    SH. Gholami

    2014-06-01

    Full Text Available The spatial distribution of soil organisms is influenced by the plant cover, thus resulting in a horizontal mosaic of areas subjected to gradients of nutrient availability and microclimatic conditions.This study was conducted to investigate the spatial variability of soil macrofauna in relation to vegetation density in the riparian forest landscape of Karkhe. The vegetation density was determined by calculating the NDVI index. Soil macrofauna were sampled using 200 sampling points along parallel transects (perpendicular to the river. The maximum distance between samples was 0.5 km. Soil macrofauna were extracted from 50 cm×50 cm×25 cm soil monolith by the hand-sorting procedure. Abundance, diversity (Shannon H’ index, richness (Menhinick index and evenness (Sheldon index were calculated. Soil macrofauna and NDVI data were analyzed using geostatistics (variogram in order to describe and quantify the spatial continuity. The variograms were spherical, revealing the presence of spatial autocorrelation. The range of influence was 1724 m for abundance, 1326 m for diversity, 1825 m for richness, 1450 for evenness and 1977 m for NDVI. The kriging maps showed that the NDVI Index and soil macrofauna had spatial variability. The spatial pattern of soil macrofauna abundance and biodiversity were similar to the spatial pattern of vegetation density as shown in the correlation.

  4. Automated flux chamber for investigating gas flux at water-air interfaces.

    Science.gov (United States)

    Duc, Nguyen Thanh; Silverstein, Samuel; Lundmark, Lars; Reyier, Henrik; Crill, Patrick; Bastviken, David

    2013-01-15

    Aquatic ecosystems are major sources of greenhouse gases (GHG). Representative measurements of GHG fluxes from aquatic ecosystems to the atmosphere are vital for quantitative understanding of relationships between biogeochemistry and climate. Fluxes occur at high temporal variability at diel or longer scales, which are not captured by traditional short-term deployments (often in the order of 30 min) of floating flux chambers. High temporal frequency measurements are necessary but also extremely labor intensive if manual flux chamber based methods are used. Therefore, we designed an inexpensive and easily mobile automated flux chamber (AFC) for extended deployments. The AFC was designed to measure in situ accumulation of gas in the chamber and also to collect gas samples in an array of sample bottles for subsequent analysis in the laboratory, providing two independent ways of CH(4) concentration measurements. We here present the AFC design and function together with data from initial laboratory tests and from a field deployment.

  5. Eddy Correlation Flux Measurement System Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D. R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration. The instruments used are: • a fast-response, three-dimensional (3D) wind sensor (sonic anemometer) to obtain the orthogonal wind components and the speed of sound (SOS) (used to derive the air temperature) • an open-path infrared gas analyzer (IRGA) to obtain the water vapor density and the CO2 concentration, and • an open-path infrared gas analyzer (IRGA) to obtain methane density and methane flux at one SGP EF and at the NSA CF. The ECOR systems are deployed at the locations where other methods for surface flux measurements (e.g., energy balance Bowen ratio [EBBR] systems) are difficult to employ, primarily at the north edge of a field of crops. A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system in SGP, NSA, Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes. The SEBS at one SGP and one NSA site also support upwelling and downwelling PAR measurements to qualify those two locations as Ameriflux sites.

  6. Role of bone mineral density in the inverse relationship between body size and aortic calcification: Results from the Baltimore Longitudinal Study of Aging

    NARCIS (Netherlands)

    Canepa, M.; Ameri, P.; AlGhatrif, M.; Pestelli, G.; Milaneschi, Y.; Strait, J.B.; Giallauria, F.; Ghigliotti, G.; Brunelli, C.; Lakatta, E.G.; Ferrucci, L.

    2014-01-01

    Objective: There is a J-shaped relationship between body mass index (BMI) and cardiovascular outcomes in elderly patients (obesity paradox). Whether low BMI correlates with aortic calcification (AC) and whether this association is accounted for by bone demineralization is uncertain. Methods:

  7. Flux pinning characteristics of YBCO coated conductor

    International Nuclear Information System (INIS)

    Matsushita, T.; Watanabe, T.; Fukumoto, Y.; Yamauchi, K.; Kiuchi, M.; Otabe, E.S.; Kiss, T.; Watanabe, T.; Miyata, S.; Ibi, A.; Muroga, T.; Yamada, Y.; Shiohara, Y.

    2005-01-01

    Flux pinning properties of PLD-processed YBCO coated conductors deposited on IBAD substrate are investigated. The thickness of YBCO layer is changed in the range of 0.27-1.0 μm. The thickness dependence of critical current density, n-value and irreversibility field are measured in a wide range of magnetic field. The results are compared with the theoretical flux creep-flow model. It is found that these pinning properties are strongly influenced by the thickness as well as the pinning strength. Optimum condition for high field application of this superconductor is discussed

  8. Directed flux motor

    Science.gov (United States)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  9. Early changes in biochemical markers of bone turnover and their relationship with bone mineral density changes after 24 months of treatment with teriparatide

    DEFF Research Database (Denmark)

    Blumsohn, A; Marin, F; Nickelsen, T

    2011-01-01

    with osteoporosis treated with teriparatide and determined: (1) whether the response is associated with prior osteoporosis therapy, (2) which marker shows the best performance for detecting a response to therapy, and (3) the correlations between early changes in bone markers and subsequent bone mineral density (BMD......) changes after 24 months of teriparatide. METHODS: We conducted a prospective, open-label, 24-month study at 95 centers in 10 countries in 758 postmenopausal women with established osteoporosis (n = 181 treatment-naïve) who had at least one post-baseline bone marker determination. Teriparatide (20 μg...

  10. Design Considerations of Permanent Magnet Transverse Flux Machines

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen

    2011-01-01

    Permanent magnet transverse flux machine (PMTFM) is well known for its high torque density and is interested in various direct-drive applications. Due to its complicated 3-D flux components, design and design optimization of a PMTFM is more difficult and time consuming than for radial flux...... electrical machines. This paper addresses two important design considerations for PMTFM—the influence of permanent magnet leakage flux, which plays an important role in the determination of machine output torque, and the leakage inductance. A new simple method to provide a quick estimation of the armature...

  11. Relationship Between Tobacco Retailers' Point-of-Sale Marketing and the Density of Same-Sex Couples, 97 U.S. Counties, 2012.

    Science.gov (United States)

    Lee, Joseph G L; Goldstein, Adam O; Pan, William K; Ribisl, Kurt M

    2015-07-28

    The reasons for higher rates of smoking among lesbian, gay, and bisexual (LGB) people than among heterosexual people are not well known. Research on internal migration and neighborhood selection suggests that LGB people are more likely to live in neighborhoods where the tobacco industry has historically targeted their marketing efforts (lower income, more racial/ethnic diversity). We used multi-level models to assess the relationship between the rate of same-sex couples per 1000 coupled households and 2012 marketing characteristics of tobacco retailers (n = 2231) in 1696 census tracts in 97 U.S. counties. We found no evidence of tobacco marketing at retailers differing by same-sex couple rates in census tracts with the exception of three findings in the opposite direction of our hypotheses: a small, significant positive relationship for the rate of same-sex male couples and the price of Newport Green (mentholated) cigarettes. For male and female same-sex couples, we also found a small negative relationship between tobacco advertisements and same-sex household rate. Tobacco retailers' tobacco marketing characteristics do not differ substantially by the rate of same-sex couples in their neighborhood in ways that would promote LGB health disparities. Further work is needed to determine if these patterns are similar for non-partnered LGB people.

  12. Relationship Between Tobacco Retailers’ Point-of-Sale Marketing and the Density of Same-Sex Couples, 97 U.S. Counties, 2012

    Science.gov (United States)

    Lee, Joseph G. L.; Goldstein, Adam O.; Pan, William K.; Ribisl, Kurt M.

    2015-01-01

    The reasons for higher rates of smoking among lesbian, gay, and bisexual (LGB) people than among heterosexual people are not well known. Research on internal migration and neighborhood selection suggests that LGB people are more likely to live in neighborhoods where the tobacco industry has historically targeted their marketing efforts (lower income, more racial/ethnic diversity). We used multi-level models to assess the relationship between the rate of same-sex couples per 1000 coupled households and 2012 marketing characteristics of tobacco retailers (n = 2231) in 1696 census tracts in 97 U.S. counties. We found no evidence of tobacco marketing at retailers differing by same-sex couple rates in census tracts with the exception of three findings in the opposite direction of our hypotheses: a small, significant positive relationship for the rate of same-sex male couples and the price of Newport Green (mentholated) cigarettes. For male and female same-sex couples, we also found a small negative relationship between tobacco advertisements and same-sex household rate. Tobacco retailers’ tobacco marketing characteristics do not differ substantially by the rate of same-sex couples in their neighborhood in ways that would promote LGB health disparities. Further work is needed to determine if these patterns are similar for non-partnered LGB people. PMID:26225987

  13. Relationship Between Tobacco Retailers’ Point-of-Sale Marketing and the Density of Same-Sex Couples, 97 U.S. Counties, 2012

    Directory of Open Access Journals (Sweden)

    Joseph G. L. Lee

    2015-07-01

    Full Text Available The reasons for higher rates of smoking among lesbian, gay, and bisexual (LGB people than among heterosexual people are not well known. Research on internal migration and neighborhood selection suggests that LGB people are more likely to live in neighborhoods where the tobacco industry has historically targeted their marketing efforts (lower income, more racial/ethnic diversity. We used multi-level models to assess the relationship between the rate of same-sex couples per 1000 coupled households and 2012 marketing characteristics of tobacco retailers (n = 2231 in 1696 census tracts in 97 U.S. counties. We found no evidence of tobacco marketing at retailers differing by same-sex couple rates in census tracts with the exception of three findings in the opposite direction of our hypotheses: a small, significant positive relationship for the rate of same-sex male couples and the price of Newport Green (mentholated cigarettes. For male and female same-sex couples, we also found a small negative relationship between tobacco advertisements and same-sex household rate. Tobacco retailers’ tobacco marketing characteristics do not differ substantially by the rate of same-sex couples in their neighborhood in ways that would promote LGB health disparities. Further work is needed to determine if these patterns are similar for non-partnered LGB people.

  14. Relationships of plasma estradiol, testosterone, and sex hormone-binding globulin with lipoproteins, apolipoproteins, and high density lipoprotein subfractions in men.

    Science.gov (United States)

    Stefanick, M L; Williams, P T; Krauss, R M; Terry, R B; Vranizan, K M; Wood, P D

    1987-04-01

    Plasma estradiol, testosterone, and sex hormone-binding globulin (SHBG) were studied in relation to plasma lipoproteins, high density lipoprotein (HDL) subfractions, and apolipoproteins in 73 healthy but sedentary middle-aged men. Among potentially confounding variables, a strong positive association was found between estradiol levels and cigarette use, while testosterone and SHBG correlated negatively with percent body fat and alcohol intake. After adjustment for smoking, percent body fat, and alcohol, plasma estradiol levels correlated negatively with total cholesterol and low density lipoprotein cholesterol, and testosterone levels correlated positively with apolipoprotein B, while SHBG levels correlated positively with HDL2 mass and apolipoprotein A-I. SHBG was also strongly associated with the waist to hip girth ratio (WHR). Adjustment for WHR eliminated the significant associations of SHBG with triglycerides, HDL2 mass, and apolipoprotein A-I. SHBG levels and WHR may reflect tissue sensitivity and the impact of exposure to fluctuating levels of sex hormones for a period of days, or longer. These variables may provide more insight into the role of sex hormones in lipoprotein metabolism than do single samples of circulating hormones. It is also suggested that long term effects of sex hormones on adipose tissue distribution may at least partially underlie sex-related differences in lipoprotein metabolism.

  15. Aeronet Solar Flux

    Data.gov (United States)

    National Aeronautics and Space Administration — SolRad-Net (Solar Radiation Network) is an established network of ground-based sensors providing high-frequency solar flux measurements in quasi-realtime to the...

  16. Flux in Tallinn

    Index Scriptorium Estoniae

    2004-01-01

    Rahvusvahelise elektroonilise kunsti sümpoosioni ISEA2004 klubiõhtu "Flux in Tallinn" klubis Bon Bon. Eestit esindasid Ropotator, Ars Intel Inc., Urmas Puhkan, Joel Tammik, Taavi Tulev (pseud. Wochtzchee). Klubiõhtu koordinaator Andres Lõo

  17. Determining Reactor Neutrino Flux

    OpenAIRE

    Cao, Jun

    2011-01-01

    Flux is an important source of uncertainties for a reactor neutrino experiment. It is determined from thermal power measurements, reactor core simulation, and knowledge of neutrino spectra of fuel isotopes. Past reactor neutrino experiments have determined the flux to (2-3)% precision. Precision measurements of mixing angle $\\theta_{13}$ by reactor neutrino experiments in the coming years will use near-far detector configurations. Most uncertainties from reactor will be canceled out. Understa...

  18. Theoretical magnetic flux emergence

    OpenAIRE

    MacTaggart, David

    2011-01-01

    Magnetic flux emergence is the subject of how magnetic fields from the solar interior can rise and expand into the atmosphere to produce active regions. It is the link that joins dynamics in the convection zone with dynamics in the atmosphere. In this thesis, we study many aspects of magnetic flux emergence through mathematical modelling and computer simulations. Our primary aim is to understand the key physical processes that lie behind emergence. The first chapter intro...

  19. Flux Emergence (Theory)

    Science.gov (United States)

    Cheung, Mark C. M.; Isobe, Hiroaki

    2014-07-01

    Magnetic flux emergence from the solar convection zone into the overlying atmosphere is the driver of a diverse range of phenomena associated with solar activity. In this article, we introduce theoretical concepts central to the study of flux emergence and discuss how the inclusion of different physical effects (e.g., magnetic buoyancy, magnetoconvection, reconnection, magnetic twist, interaction with ambient field) in models impact the evolution of the emerging field and plasma.

  20. The Relationship between Sap Flow Density and  Environmental Factors in the Yangtze River Delta  Region of China

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2017-03-01

    Full Text Available Canopy transpiration is an important component of evapotranspiration, integrating physical and biological processes within the water and energy cycles of forests. Quercus acutissima and Cunninghamia lanceolata are two important, fast‐growing and commercial tree species that have been extensively used for vegetation restoration, water conservation and building artificial forests in the Yangtze River Delta region of China. The primary objective of this study was to characterize sap flow densities of the two species by comparing daytime and nocturnal sap flow patterns and their relationships with environmental factors. Sap flow densities (Sd were measured between September 2012 and August 2013 using the commercially‐available thermal dissipation probes. Hourly meteorological data were measured in an open field, located 200 m away from the study site, including photosynthetically‐active radiation (Par, air temperature (Ta, relative air humidity (Rh, vapor pressure deficit (Vpd and precipitation (P. Soil water content (Swc data were logged hourly in different layers at Q. acutissima and C. lanceolata forests. Results indicated that the mean Sd in summer was higher than that in spring and autumn. Both the Sd of Q. acutissima and C. lanceolata showed distinct diurnal patterns. Nocturnal sap flow densities (Sdn were noticeable, and both species followed similar declining patterns during our study period. The daytime sap flow density (Sdd was more sensitive to environmental factors than Sdn. Sap flow density was significant linearly correlated with Par, Vpd and Ta, and Par and Vpd explained the greatest amount of variation in daytime sap flow of Q. acutissima and C. lanceolata, respectively. Our study will enrich knowledge of plantation forest physical and biological processes and provide valuable information for plantation forest management in the Yangtze River Delta region of China.

  1. Neutron flux monitor

    International Nuclear Information System (INIS)

    Oda, Naotaka.

    1993-01-01

    The device of the present invention greatly saves an analog processing section such as an analog filter and an analog processing circuit. That is, the device of the present invention comprises (1) a neutron flux detection means for detecting neutron fluxed in the reactor, (2) a digital filter means for dividing signals corresponding to the detected neutron fluxes into predetermined frequency band regions, (3) a calculation processing means for applying a calculation processing corresponding to the frequency band regions to the neutron flux detection signals divided by the digital filter means. With such a constitution, since the neutron detection signals are processed by the digital filter means, the accuracy is improved and the change for the property of the filter is facilitated. Further, when a neutron flux level is obtained, a calculation processing corresponding to the frequency band region can be conducted without the analog processing circuit. Accordingly, maintenance and accuracy are improved by greatly decreasing the number of parts. Further, since problems inherent to the analog circuit are solved, neutron fluxes are monitored at high reliability. (I.S.)

  2. Primary stability, insertion torque and bone density of cylindric implant ad modum Branemark: is there a relationship? An in vitro study.

    Science.gov (United States)

    Trisi, Paolo; De Benedittis, Simona; Perfetti, Giorgio; Berardi, Davide

    2011-05-01

    Protocols of immediate loading have been reported in several studies. It has also been demonstrated that the cause of failure of immediate loaded implants is due to the micromotion on the bone-implant interface induced by immediate loading. There should be a minimum gap between the implant and the peri-implant bone, without micromotions occurring above a definite threshold risk as they induce bone resorption and fibrosis around the implant. Measurement of the torque necessary to insert an implant in the bone is a parameter for measuring initial stability. The higher the implant insertion torque, the higher the initial stability attained. The aim of this study was to evaluate in vitro the correlation between the micromotion of cylindric screw implants ad modum Branemark and the insertion torque in bone of different densities. The test was carried out on 2 × 2 cm samples of fresh bovine bone of three different densities: hard (H), medium (M) and soft (S). One hundred and fifty hexa implants ad modum Branemark were used, 3.75 mm in diameter and 9 mm long. To screw in the implants, a customized manual key was used, controlled digitally to evaluate the peak insertion torques. Ten implants were prepared for each torque (20, 35, 45, 70 and 100 N/cm). The bone sample was then fixed on a loading device, which allowed evaluating the micromotion. On each sample, we applied a 25 N horizontal force. The results indicate that the peak insertion torque and the implant micromotion are statistically correlated, and statistically significant differences in H and M bone were found compared with S bone. In S bone, we noted a micromotion significantly higher than the risk threshold, and it was not possible to reach peak insertion torque above 35 N/cm. In H and M bone, the micromotion is below the threshold of all insertion torques. Increasing the peak insertion torque, we can reduce the extent of the micromotion between the implant and the bone when submitted to lateral forces in

  3. Energy and energy flux in axisymmetric slow and fast waves

    Science.gov (United States)

    Moreels, M. G.; Van Doorsselaere, T.; Grant, S. D. T.; Jess, D. B.; Goossens, M.

    2015-06-01

    Aims: We aim to calculate the kinetic, magnetic, thermal, and total energy densities and the flux of energy in axisymmetric sausage modes. The resulting equations should contain as few parameters as possible to facilitate applicability for different observations. Methods: The background equilibrium is a one-dimensional cylindrical flux tube model with a piecewise constant radial density profile. This enables us to use linearised magnetohydrodynamic equations to calculate the energy densities and the flux of energy for axisymmetric sausage modes. Results: The equations used to calculate the energy densities and the flux of energy in axisymmetric sausage modes depend on the radius of the flux tube, the equilibrium sound and Alfvén speeds, the density of the plasma, the period and phase speed of the wave, and the radial or longitudinal components of the Lagrangian displacement at the flux tube boundary. Approximate relations for limiting cases of propagating slow and fast sausage modes are also obtained. We also obtained the dispersive first-order correction term to the phase speed for both the fundamental slow body mode under coronal conditions and the slow surface mode under photospheric conditions. Appendix A is available in electronic form at http://www.aanda.org

  4. A note on vector flux models for radiation dose calculations

    International Nuclear Information System (INIS)

    Kern, J.W.

    1994-01-01

    This paper reviews and extends modelling of anisotropic fluxes for radiation belt protons to provide closed-form equations for vector proton fluxes and proton flux anisotropy in terms of standard omnidirectional flux models. These equations provide a flexible alternative to the date-based vector flux models currently available. At higher energies, anisotropy of trapped proton flux in the upper atmosphere depends strongly on the variation of atmospheric density with altitude. Calculations of proton flux anisotropies using present models require specification of the average atmospheric density along trapped particle trajectories and its variation with mirror point altitude. For an isothermal atmosphere, calculations show that in a dipole magnetic field, the scale height of this trajectory-averaged density closely approximates the scale height of the atmosphere at the mirror point of the trapped particle. However, for the earth's magnetic field, the altitudes of mirror points vary for protons drifting in longitude. This results in a small increase in longitude-averaged scale heights compared to the atmospheric scale heights at minimum mirror point altitudes. The trajectory-averaged scale heights are increased by about 10-20% over scale heights from standard atmosphere models for protons mirroring at altitudes less than 500 km in the South Atlantic Anomaly Atmospheric losses of protons in the geomagnetic field minimum in the South Atlantic Anomaly control proton flux anisotropies of interest for radiation studies in low earth orbit. Standard atmosphere models provide corrections for diurnal, seasonal and solar activity-driven variations. Thus, determination of an ''equilibrium'' model of trapped proton fluxes of a given energy requires using a scale height that is time-averaged over the lifetime of the protons. The trajectory-averaged atmospheric densities calculated here lead to estimates for trapped proton lifetimes. These lifetimes provide appropriate time

  5. Relationships between the distribution of O atoms on partially oxidized metal (Al, Ag, Cu, Ti, Zr, Hf) surfaces and the adsorption energy: A density-functional theory study

    Science.gov (United States)

    Houska, J.; Kozak, T.

    2017-06-01

    We investigate the oxidation of selected metal (Al, Ag, Cu, Ti, Zr, and Hf) surfaces by the density functional theory. We go through a wide range of (233 per metal) distributions of O atoms on a partially oxidized metal surface. First, we focus on the qualitative information whether the preferred distribution of O atoms is heterogeneous (stoichiometric oxide + metal) or homogeneous (substoichiometric oxide). We find that the former is energetically preferred, e.g., for Al, while the latter is energetically preferred, e.g., for Ti, Zr, and Hf. Second, we provide the quantitative values of adsorption energies corresponding to the energetically preferred O atom distributions for various partial coverages of various metals by O. Third, we discuss and show an example of implications of the aforementioned findings for the understanding and simulations of sputtering.

  6. Calorific value of Prosopis africana and Balanites aegyptiaca wood: Relationships with tree growth, wood density and rainfall gradients in the West African Sahel

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Carmen Sotelo; Weber, John C. [World Agroforestry Centre (ICRAF), Sahel Office, B.P. E 5118 Bamako (Mali); Silva, Dimas Agostinho da; Bolzon de Muniz, Graciela Ines [Universidade Federal do Parana (UFPR), Av. Lothario Meissner, 900, CEP.: 80270-170-Curitiba (Brazil); Garcia, Rosilei A. [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Instituto de Florestas, Departamento de Produtos Florestais, BR 465, km 07, 23890-000, Seropedica, Rio de Janeiro (Brazil)

    2011-01-15

    Prosopis africana and Balanites aegyptiaca are native tree species in the West African Sahel and provide wood for fuel, construction and other essential products. A provenance/progeny test of each species was established at one relatively dry site in Niger, and evaluated at 13 years. Gross calorific value of the wood was determined for a random sample of trees in each test: gross CV and CVm{sup 3} = gross calorific value in MJ kg{sup -1} and MJ m{sup -3}, respectively. The major objectives were to determine if gross CV was positively correlated with wood density and tree growth, and if gross CV and/or CVm{sup 3} varied with rainfall gradients in the sample region. Provenances were grouped into a drier and more humid zone, and correlations were computed among all trees and separately in each zone. Results indicated that gross CV was not significantly correlated with density in either species. Gross CV was positively correlated with growth of P. africana (but not B. aegyptiaca) only in the drier zone. Gross CVm{sup 3} was positively correlated with growth of both species, and the correlations were stronger in the drier zone. Multiple regressions with provenance latitude, longitude and elevation indicated that provenance means for gross CV increased, in general, from the drier to the more humid zones. Regressions with gross CVm{sup 3} were not significant. Results are compared with earlier research reports from the provenance/progeny tests and with other tropical hardwood species; and practical implications are presented for tree improvement and conservation programs in the region. (author)

  7. Osteonecrosis Diagnosed on MR Images of the Knee. Relationship to reduced bone mineral density determined by high resolution peripheral quantitative CT

    International Nuclear Information System (INIS)

    Zanetti, M.; Hodler, J.; Romero, J.; Dambacher, M.A.

    2003-01-01

    Purpose: To evaluate if osteonecrosis diagnosed on MR images of the knee relates to reduced bone mineral density (BMD) and may be caused by an insufficiency fracture. Material and Methods: Thirty-two consecutive patients (8 men, 24 women; age range 27-82 years, mean 62 years) with MR findings of osteonecrosis of the femoral or tibial condyle were prospectively included. Trabecular and cortical BMD were measured with high resolution peripheral quantitative CT in the non-dominant distal radius and the tibia of the involved extremity. One tibia was not measured due to posttraumatic deformity. Results: The mean trabecular BMD of the radius was 81% of the young-adult average peak BMD (range 19-160%). The mean cortical BMD in the radius was 86% (range 63-108%). The mean trabecular BMD in the tibia was 92% (range 28-160%). The mean cortical BMD in the tibia was 86% (range 49-132%). The values of the trabecular bone of the distal radius (tibia) were normal in 11 (15) patients, osteopenic in 12 (4), and osteoporotic in 9 (12), respectively. The cortical bone values of the distal radius (tibia) were normal in 12 (13) patients, osteopenic in 12 (12), and osteoporotic in 8 (6), respectively. Conclusion: Osteoporosis and osteopenia are commonly found in patients with osteonecrosis of the knee as diagnosed on MR images. This indicates that for some patients an insufficiency mechanism may be responsible for the MR findings. However, in the patients with normal bone density other reasons for osteonecrosis may be present

  8. Methane flux in cropland and adjacent riparian buffers with different vegetation covers.

    Science.gov (United States)

    Kim, Dong-Gill; Isenhart, Thomas M; Parkin, Timothy B; Schultz, Richard C; Loynachan, Thomas E

    2010-01-01

    While water quality functions of conservation buffers established adjacent to cropped fields have been widely documented, the relative contribution of these re-established perennial plant systems to greenhouse gases has not been completely documented. In the case of methane (CH(4)), these systems have the potential to serve as sinks of CH(4) or may provide favorable conditions for CH(4) production. This study quantifies CH(4) flux from soils of riparian buffer systems comprised of three vegetation types and compares these fluxes with those of adjacent crop fields. We measured soil properties and diel and seasonal variations of CH(4) flux in 7 to 17 yr-old re-established riparian forest buffers, warm-season and cool-season grass filters, and an adjacent crop field located in the Bear Creek watershed in central Iowa. Forest buffer and grass filter soils had significantly lower bulk density (P < 0.01); and higher pH (P < 0.01), total carbon (TC) (P < 0.01), and total nitrogen (TN) (P < 0.01) than crop field soils. There was no significant relationship between CH(4) flux and soil moisture or soil temperature among sites within the range of conditions observed. Cumulative CH(4) flux was -0.80 kg CH(4)-C ha(-1) yr(-1) in the cropped field, -0.46 kg CH(4)-C ha(-1) yr(-1) within the forest buffers, and 0.04 kg CH(4)-C ha(-1) yr(-1) within grass filters, but difference among vegetation covers was not significant. Results suggest that CH(4) flux was not changed after establishment of perennial vegetation on cropped soils, despite significant changes in soil properties.

  9. Color magnetic flux tubes in dense QCD

    International Nuclear Information System (INIS)

    Eto, Minoru; Nitta, Muneto

    2009-01-01

    QCD is expected to be in the color-flavor locking phase in high baryon density, which exhibits color superconductivity. The most fundamental topological objects in the color superconductor are non-Abelian vortices which are topologically stable color magnetic flux tubes. We present numerical solutions of the color magnetic flux tube for diverse choices of the coupling constants based on the Ginzburg-Landau Lagrangian. We also analytically study its asymptotic profiles and find that they are different from the case of usual superconductors. We propose the width of color magnetic fluxes and find that it is larger than naive expectation of the Compton wavelength of the massive gluon when the gluon mass is larger than the scalar mass.

  10. Hamiltonian boundary term and quasilocal energy flux

    International Nuclear Information System (INIS)

    Chen, C.-M.; Nester, James M.; Tung, R.-S.

    2005-01-01

    The Hamiltonian for a gravitating region includes a boundary term which determines not only the quasilocal values but also, via the boundary variation principle, the boundary conditions. Using our covariant Hamiltonian formalism, we found four particular quasilocal energy-momentum boundary term expressions; each corresponds to a physically distinct and geometrically clear boundary condition. Here, from a consideration of the asymptotics, we show how a fundamental Hamiltonian identity naturally leads to the associated quasilocal energy flux expressions. For electromagnetism one of the four is distinguished: the only one which is gauge invariant; it gives the familiar energy density and Poynting flux. For Einstein's general relativity two different boundary condition choices correspond to quasilocal expressions which asymptotically give the ADM energy, the Trautman-Bondi energy and, moreover, an associated energy flux (both outgoing and incoming). Again there is a distinguished expression: the one which is covariant

  11. Tokamak disruption heat flux simulator

    International Nuclear Information System (INIS)

    Langhoff, M.; Hess, G.; Gahl, J.; Ingram, R.

    1990-01-01

    A coaxial plasma gun system, operating in the deflagration mode, has been built and fired at the University of New Mexico. This system, powered by a 100 kJ capacitor bank, was designed to give a variable pulse length of approximately 50-100 us. The gun is intended to deliver to a target an energy deposition density of 1 kJ per cm 2 via impact with a deuterium plasma possessing a highly directed energy. This system should simulate on the target, over an area of approximately 10 cm 2 , the heat flux of a tokamak plasma disruption on plasma facing components. Current diagnostics for the system are rather rudimentary but sufficient for determination of plasma pulse characteristics and energy transfer to target. Electrical measurements include bank voltage measured via resistive voltage dividers, and bank current measured via Rogowski coil. The shape of the plasma, its position relative to the target area, and the final impact area, is determined via open-shutter photography and the use of witness plates. Total energy deposited onto targets will be determined through simple calorimetry and careful target mass measurements. Preliminary results describing the ablation of carbon targets exposed to disruption like heat fluxes will be presented as well as a description of the experimental apparatus

  12. The Open Flux Problem

    International Nuclear Information System (INIS)

    Linker, J. A.; Caplan, R. M.; Downs, C.; Riley, P.; Mikic, Z.; Lionello, R.; Henney, C. J.; Arge, C. N.; Liu, Y.; Derosa, M. L.; Yeates, A.; Owens, M. J.

    2017-01-01

    The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun’s photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full-disk magnetograms are commonly used as boundary conditions for coronal and solar wind models. Two primary observational constraints on the models are (1) the open field regions in the model should approximately correspond to coronal holes (CHs) observed in emission and (2) the magnitude of the open magnetic flux in the model should match that inferred from in situ spacecraft measurements. In this study, we calculate both magnetohydrodynamic and potential field source surface solutions using 14 different magnetic maps produced from five different types of observatory magnetograms, for the time period surrounding 2010 July. We have found that for all of the model/map combinations, models that have CH areas close to observations underestimate the interplanetary magnetic flux, or, conversely, for models to match the interplanetary flux, the modeled open field regions are larger than CHs observed in EUV emission. In an alternative approach, we estimate the open magnetic flux entirely from solar observations by combining automatically detected CHs for Carrington rotation 2098 with observatory synoptic magnetic maps. This approach also underestimates the interplanetary magnetic flux. Our results imply that either typical observatory maps underestimate the Sun’s magnetic flux, or a significant portion of the open magnetic flux is not rooted in regions that are obviously dark in EUV and X-ray emission.

  13. Current density imaging using directly measured harmonic Bz data in MREIT.

    Science.gov (United States)

    Park, Chunjae; Kwon, Oh In

    2013-01-01

    Magnetic resonance electrical impedance tomography (MREIT) measures magnetic flux density signals through the use of a magnetic resonance imaging (MRI) in order to visualize the internal conductivity and/or current density. Understanding the reconstruction procedure for the internal current density, we directly measure the second derivative of Bz data from the measured k-space data, from which we can avoid a tedious phase unwrapping to obtain the phase signal of Bz . We determine optimal weighting factors to combine the derivatives of magnetic flux density data, [Symbol: see text](2) Bz , measured using the multi-echo train. The proposed method reconstructs the internal current density using the relationships between the induced internal current and the measured [Symbol: see text](2) Bz data. Results from a phantom experiment demonstrate that the proposed method reduces the scanning time and provides the internal current density, while suppressing the background field inhomogeneity. To implement the real experiment, we use a phantom with a saline solution including a balloon, which excludes other artifacts by any concentration gradient in the phantom.

  14. Current Density Imaging Using Directly Measured Harmonic Bz Data in MREIT

    Directory of Open Access Journals (Sweden)

    Chunjae Park

    2013-01-01

    Full Text Available Magnetic resonance electrical impedance tomography (MREIT measures magnetic flux density signals through the use of a magnetic resonance imaging (MRI in order to visualize the internal conductivity and/or current density. Understanding the reconstruction procedure for the internal current density, we directly measure the second derivative of Bz data from the measured k-space data, from which we can avoid a tedious phase unwrapping to obtain the phase signal of Bz. We determine optimal weighting factors to combine the derivatives of magnetic flux density data, ∇2Bz, measured using the multi-echo train. The proposed method reconstructs the internal current density using the relationships between the induced internal current and the measured ∇2Bz data. Results from a phantom experiment demonstrate that the proposed method reduces the scanning time and provides the internal current density, while suppressing the background field inhomogeneity. To implement the real experiment, we use a phantom with a saline solution including a balloon, which excludes other artifacts by any concentration gradient in the phantom.

  15. Relationship Between Femur Bone Mineral Density, Body Mass Index and Dental Panoramic Mandibular Cortical Width in Diagnosis of Elderly Postmenopausal Women With Osteoporosis

    Science.gov (United States)

    Devi B.K., Yashoda; Rakesh, N.; Reddy, Sujatha S.; Santana, N.; Shetty, Naresh

    2014-01-01

    Objectives: To measure and determine mandibular cortical width (MCW) on the panoramic radiographs, to evaluate the usefulness of the method in identifying postmenopausal women with low femoral bone mineral densities (f- BMD) and to correlate the radiographic findings on panoramic radiographs with the f-BMD assessed by dual X-ray absorptiometry (DXA) to predict the efficacy of the radiographic method in diagnosing osteoporosis. Materials and Methods: One hundred and twenty postmenopausal women (60 normal and 60 osteoporotic) in the age group of 50-75 y with f-BMD assessed by DXA had undergone panoramic radiographic examination. The patients were classified as normal (T-score ≥ -1.0) and osteoporotic (T-score ≤ -2.5). MCW on panoramic radiographs was measured bilaterally at the mental foramen region with a caliper and their mean was used as the exposure measure in the analysis. Results: Student t-test showed that mean f-BMD, BMI and MCW was found be less in osteoporotic patients as compared to normal group with a statistically significant p-value fractures. Mandibular inferior cortical width at the mental foramen region could be used to identify postmenopausal women with low f- BMD. Hence, dental panoramic radiographs serve as a useful screening tool for early diagnosis of osteoporotic fractures. PMID:25302265

  16. Vertical profiles of specific surface area, thermal conductivity and density of mid-latitude, Arctic and Antarctic snow: relationships between snow physics and climat

    Science.gov (United States)

    Domine, F.; Arnaud, L.; Bock, J.; Carmagnola, C.; Champollion, N.; Gallet, J.; Lesaffre, B.; Morin, S.; Picard, G.

    2011-12-01

    We have measured vertical profiles of specific surface area (SSA), thermal conductivity (TC) and density in snow from 12 different climatic regions featuring seasonal snowpacks of maritime, Alpine, taiga and tundra types, on Arctic sea ice, and from ice caps in Greenland and Antarctica. We attempt to relate snow physical properties to climatic variables including precipitation, temperature and its yearly variation, wind speed and its short scale temporal variations. As expected, temperature is a key variable that determines snow properties, mostly by determining the metamorphic regime (temperature gradient or equi-temperature) in conjunction with precipitation. However, wind speed and wind speed distribution also seem to have an at least as important role. For example high wind speeds determine the formation of windpacks of high SSA and high TC instead of depth hoar with lower values of these variables. The distribution of wind speed also strongly affects properties, as for example frequent moderate winds result in frequent snow remobilization, producing snow with higher SSA and lower TC than regions with the same average wind speeds, but with less frequent and more intense wind episodes. These strong effects of climate on snow properties imply that climate change will greatly modify snow properties, which in turn will affect climate, as for example changes in snow SSA modify albedo and changes in TC affect permafrost and the release of greenhouse gases from thawing permafrost. Some of these climate-snow feedbacks will be discussed.

  17. An Ecology of Prestige in New York City: Examining the Relationships Among Population Density, Socio-economic Status, Group Identity, and Residential Canopy Cover

    Science.gov (United States)

    Grove, J. Morgan; Locke, Dexter H.; O'Neil-Dunne, Jarlath P. M.

    2014-09-01

    Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City's property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont's Spatial Analysis Lab (SAL). These data are analyzed using a multi-model inferential, spatial econometrics approach. We also examine the distribution of vegetation within distinct market categories using Claritas' Potential Rating Index for Zipcode Markets (PRIZM™) database. These categories can be disaggregated, corresponding to the four social theories. We compare the econometric and categorical results for validation. Models associated with ecology of prestige theory are more effective for predicting the distribution of vegetation. This suggests that private, residential patterns of vegetation, reflecting the consumption of environmentally relevant goods and services, are associated with different lifestyles and lifestages. Further, our spatial and temporal analyses suggest that there are significant spatial and temporal dependencies that have theoretical and methodological implications for understanding urban ecological systems. These findings may have policy implications. Decision makers may need to consider how to most effectively reach different social groups in terms of messages and messengers in order to advance land management practices and achieve urban sustainability.

  18. Relationship between Weight, Body Mass Index, and Bone Mineral Density in Men Referred for Dual-Energy X-Ray Absorptiometry Scan in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Salamat

    2013-01-01

    Full Text Available Objective. Although several studies have investigated the association between body mass index (BMI and bone mineral density (BMD, the results are inconsistent. The aim of this study was to further investigate the relation between BMI, weight and BMD in an Iranian men population. Methods. A total of 230 men 50-79 years old were examined. All men underwent a standard BMD scans of hip (total hip, femoral neck, trochanter, and femoral shaft and lumbar vertebrae (L2-L4 using a Dual-Energy X-ray Absorptiometry (DXA scan and examination of body size. Participants were categorised in two BMI group: normal weight <25.0 kg/m2 and overweight and obese, BMI ≥ 25 kg/m2. Results. Compared to men with BMI ≥ 25, the age-adjusted odds ratio of osteopenia was 2.2 (95% CI 0.85, 5.93 and for osteoporosis was 4.4 (1.51, 12.87 for men with BMI < 25. It was noted that BMI and weight was associated with a high BMD, compatible with a diagnosis of osteoporosis. Conclusions. These data indicate that both BMI and weight are associated with BMD of hip and vertebrae and overweight and obesity decreased the risk for osteoporosis. The results of this study highlight the need for osteoporosis prevention strategies in elderly men as well as postmenopausal women.

  19. The low energy neutral fluxes and their impurity production at the walls of ASDEX

    International Nuclear Information System (INIS)

    Verbeek, H.; Dose, V.; Fu, J.K.; Gehre, O.; Gernhardt, J.; Janeschitz, G.; Mueller, E.R.; Roehr, H.; Steuer, K.H.; Soeldner, F.X.

    1988-01-01

    With the Low Energy Neutral particle Analyser LENA at ASDEX the density dependence of the neutral flux, its mean energy and its impurity production at the walls has been investigated for ohmic hydrogen and deuterium discharges. For hydrogen a large increase of the neutral flux with increasing density was observed, while the mean energy of the neutrals decreases. This holds for hydrogen over the whole range of densities. At constant density the low energy neutral flux increases with the safety factor q. This is in contrast to the high energy flux as measured with the charge exchange analyser. The flux increase of the low energy neutrals can be correlated with the increased decay length of the electron density for higher q-values. For deuterium the same behaviour up to densities of n ≅ 3.5x10 13 cm -3 was observed. For higher densities the flux behaves different corresponding to the different confinement regimes. Only in the regime of saturated ohmic confinement, known so far, the flux increases further with increasing n. With the operational conditions of the new divertor configuration in ASDEX a further increase of τ E with n up to the density limit was observed (improved Ohmic confinement). In this regime the neutral flux saturates with increasing n. In spite of the reduced impurity production at the walls, Z eff increases in this case. (orig.)

  20. Divertor Heat Flux Mitigation in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soukhanovskii, V A; Maingi, R; Gates, D A; Menard, J E; Paul, S F; Raman, R; Roquemore, A L; Bell, M G; Bell, R E; Boedo, J A; Bush, C E; Kaita, R; Kugel, H W; LeBlanc, B P; Mueller, D

    2008-08-04

    Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly-shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m{sup -2} to 0.5-2 MW m{sup -2} in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.

  1. Assessment of anterior subcutaneous hypersignal on proton-density-weighted MR imaging of the knee and relationship with anterior knee pain.

    Science.gov (United States)

    Unlu, E N; Turhan, Y; Kos, D M; Safak, A A

    2017-04-01

    The purpose of this study was to evaluate the prevalence of anterior subcutaneous hypersignal indicating edema on proton-density (PD)-weighted MRI of the knee and to determine whether reporting anterior edema is clinically relevant. One hundred and ninety-one knee MRIs from 162 patients were reviewed for anterior subcutaneous edema. There were 92 men and 70 women with a mean age of 41.72years±13.92 (SD) (range, 15-80years) years and a mean body weight of 75.94kg±12.54 (SD) (range, 50-130kg). The MRI findings were compared with patient age, gender, body weight, history of repetitive microtrauma and clinical findings. Patellar and trochlear chondropathy, medial plica, joint effusion, synovitis, infrapatellar fat-pad signal intensity, suprapatellar fat-pad signal intensity with mass effect, quadriceps and patellar tendon abnormalities were also reviewed. An anterior hypersignal on PD-weighted MRI was detected in 158/191 MR examinations (82.7%) and 104 (84.6%) of these cases had histories of anterior knee pain. No correlation between anterior pain and anterior edema was found (P=0.42). Age (Panterior edema. Anterior edema may be a physiological phenomenon or degenerative change related to patient age, weight, and knee movement or mechanics. It should not be reported as a pathological finding on MRI unless clinical findings support regional infection or inflammation. Copyright © 2016 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  2. A finite element calculation of flux pumping

    Science.gov (United States)

    Campbell, A. M.

    2017-12-01

    A flux pump is not only a fascinating example of the power of Faraday’s concept of flux lines, but also an attractive way of powering superconducting magnets without large electronic power supplies. However it is not possible to do this in HTS by driving a part of the superconductor normal, it must be done by exceeding the local critical density. The picture of a magnet pulling flux lines through the material is attractive, but as there is no direct contact between flux lines in the magnet and vortices, unless the gap between them is comparable to the coherence length, the process must be explicable in terms of classical electromagnetism and a nonlinear V-I characteristic. In this paper a simple 2D model of a flux pump is used to determine the pumping behaviour from first principles and the geometry. It is analysed with finite element software using the A formulation and FlexPDE. A thin magnet is passed across one or more superconductors connected to a load, which is a large rectangular loop. This means that the self and mutual inductances can be calculated explicitly. A wide strip, a narrow strip and two conductors are considered. Also an analytic circuit model is analysed. In all cases the critical state model is used, so the flux flow resistivity and dynamic resistivity are not directly involved, although an effective resistivity appears when J c is exceeded. In most of the cases considered here is a large gap between the theory and the experiments. In particular the maximum flux transferred to the load area is always less than the flux of the magnet. Also once the threshold needed for pumping is exceeded the flux in the load saturates within a few cycles. However the analytic circuit model allows a simple modification to allow for the large reduction in I c when the magnet is over a conductor. This not only changes the direction of the pumped flux but leads to much more effective pumping.

  3. Efeito da densidade do fluxo e da presença de aditivos na soldagem ATIG de aço inoxidável austenítico Effect of flux density and addictive presence on ATIG welding of austenitic stainless steel

    Directory of Open Access Journals (Sweden)

    Paulo J. Modenesi

    2013-06-01

    explain the effect of flux. The most accepted ones consider the arc contraction by negative ions vaporized from the flux and liquid metal flow alterations in the weld pool caused by changes the surface tension values. This paper evaluates the effect of one component (Cr2O3 flux concentration and additions of KClO4 and Al2O3 on ATIG welding bead shape. Three sets of bead-on-plate weld tests were performed on 5 mm thick AISI 304 steel plates. Electric current and voltage were measured during each welding trial and the resulting bead geometry was evaluated in cross sections of the weld. Results indicated only minor variations in voltage during the transition from TIG to ATIG welding. Surface flux concentration affected weld bead penetration, and maximum penetration was obtained with flux densities between 15 and 60 g/m². On the other hand, the addition of KCLO4, despite this being a strong oxidizer, reduced weld penetration. A similar effect was linked to additions of Al2O3 to the flux.

  4. Relationships between soil organic status and microbial community density and genetic structure in two agricultural soils submitted to various types of organic management.

    Science.gov (United States)

    Lejon, David P H; Sebastia, Julien; Lamy, Isabelle; Chaussod, Rémi; Ranjard, Lionel

    2007-05-01

    The effects of soil organic management on indigenous microorganisms were studied by comparing mulching straw (S), conifer compost (CC), and conifer bark (CB) as well as grass landing with grass (G), clover (Cl), and fescue (F) in a silty-clay soil (Mâcon), and by incorporating vine shoot (VS) and single and double doses of farmyard manure (FM) and mushroom manure (MM) in a calcareous sandy soil (Chinon). Soil physicochemical and microbial characteristics were assessed at each site at two depths by sampling at 0-5 and 5-20 cm for the Mâcon site and 0-10 and 10-20 cm for the Chinon site. Changes in the quantity of soil organic matter (SOM), through an increase in C(org) and N(org) contents, and in its quality, through modifications in the C/N and humic acid/fulvic acid ratios, were essentially recorded at the surface layer of treated plots with differential magnitudes according to the inputs and soil type. Quantitative modifications in microbial communities were assessed by means of C-biomass measurements and resulted in an increase in microbial densities fitted with the increase of C(org) and N(org) contents. However, the deduced C incorporation in microbial biomass was negatively correlated with the C/N ratio, demonstrating a strong influence of the type of organic management on the rate of microbial processes. Qualitative modifications in microbial communities were evaluated by the characterization of the genetic structure of bacterial and fungal communities from DNA directly extracted from the soil, using bacterial and fungal automated ribosomal intergenic spacer analysis. Organic amendments led to changes in the bacterial and fungal communities of both sites. However, the magnitude and the specificity of these changes were different between sites, organic amendments, and microorganisms targeted, revealing that the impact of organic management is dependent on the soil and organic input types as well as on the particular ecology of microorganisms. A co

  5. Soluble organic nutrient fluxes

    Science.gov (United States)

    Robert G. Qualls; Bruce L. Haines; Wayne Swank

    2014-01-01

    Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

  6. Radiation flux measuring device

    International Nuclear Information System (INIS)

    Corte, E.; Maitra, P.

    1977-01-01

    A radiation flux measuring device is described which employs a differential pair of transistors, the output of which is maintained constant, connected to a radiation detector. Means connected to the differential pair produce a signal representing the log of the a-c component of the radiation detector, thereby providing a signal representing the true root mean square logarithmic output. 3 claims, 2 figures

  7. Muon and neutrino fluxes

    Science.gov (United States)

    Edwards, P. G.; Protheroe, R. J.

    1985-01-01

    The result of a new calculation of the atmospheric muon and neutrino fluxes and the energy spectrum of muon-neutrinos produced in individual extensive air showers (EAS) initiated by proton and gamma-ray primaries is reported. Also explained is the possibility of detecting atmospheric nu sub mu's due to gamma-rays from these sources.

  8. Flux scaling: Ultimate regime

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Flux scaling: Ultimate regime. With the Nusselt number and the mixing length scales, we get the Nusselt number and Reynolds number (w'd/ν) scalings: and or. and. scaling expected to occur at extremely high Ra Rayleigh-Benard convection. Get the ultimate regime ...

  9. Low Bone Density

    Science.gov (United States)

    ... Bone Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone ... to people with normal bone density. Detecting Low Bone Density A bone density test will determine whether ...

  10. Novel Transverse Flux Machine for Vehicle Traction Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Z.; Ahmed, A.; Husain, I.; Muljadi, E.

    2015-04-02

    A novel transverse flux machine topology for electric vehicle traction applications using ferrite magnets is presented in this paper. The proposed transverse flux topology utilizes novel magnet arrangements in the rotor that are similar to the Halbach array to boost flux linkage; on the stator side, cores are alternately arranged around a pair of ring windings in each phase to make use of the entire rotor flux that eliminates end windings. Analytical design considerations and finite-element methods are used for an optimized design of a scooter in-wheel motor. Simulation results from finite element analysis (FEA) show that the motor achieved comparable torque density to conventional rare-earth permanent magnet (PM) machines. This machine is a viable candidate for direct-drive applications with low cost and high torque density.

  11. Reactor G1 - Flux charts in the flat pile

    International Nuclear Information System (INIS)

    Genthon, J.P.

    1957-10-01

    Experimental flux charts are available for different pile conditions. Data in these charts are given as points. The flux density at each point is the result of the irradiation and counting of a detector, followed by plotting of this count. All these flux density measurements are relative. The different flux charts studied are always relative to the fiat pile, loading side; this will give us: - the flat pile full for the Laplacian measurement; - the flat pile full for the study of the variation of the cadmium ratio; - the flat pile, central canal empty; - the flat pile, central canal plugged with graphite; - the flat pile, central canal containing a cadmium rod; - the flat pile, central canal containing a thorium rod. (author) [fr

  12. Upland Forest Linkages to Seasonal Wetlands: Litter Flux, Processing, and Food Quality

    Science.gov (United States)

    Brian J. Palik; Darold P. Batzer; Christel Kern

    2005-01-01

    The flux of materials across ecosystem boundaries has significant effects on recipient systems. Because of edge effects, seasonal wetlands in upland forest are good systems to explore these linkages. The purpose of this study was to examine flux of coarse particulate organic matter as litter fall into seasonal wetlands in Minnesota, and the relationship of this flux to...

  13. ULY JUP COSPIN HIGH FLUX TELESCOPE HIGH RES. ION FLUX

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains ion flux data recorded by the COSPIN High Flux Telescope (HFT) during the Ulysses Jupiter encounter 1992-Jan-25 to 1992-Feb-18.

  14. Subsolidus phase relationships in the system ZnO-V{sub 2}O{sub 5}-WO{sub 3} research on suitable flux for ZnO crystal growth

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xianzhi [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, National Engineering Research Center for Optoelectronic Crystalline Materials, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Chen Dagui [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, National Engineering Research Center for Optoelectronic Crystalline Materials, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)], E-mail: chendg@fjirsm.ac.cn; Lv Peiwen; Yan Fengbo; Zhan Zhibing; Li Bin [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, National Engineering Research Center for Optoelectronic Crystalline Materials, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Huang Feng [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, National Engineering Research Center for Optoelectronic Crystalline Materials, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)], E-mail: fhuang@fjirsm.ac.cn; Liang Jingkui [Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, National Engineering Research Center for Optoelectronic Crystalline Materials, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China); Beijing National Laboratory for Condensed Matter Physics, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080 (China); International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016 (China)

    2009-05-12

    The subsolidus phase relations of the ternary system ZnO-V{sub 2}O{sub 5}-WO{sub 3} was investigated by means of X-ray diffraction (XRD) analysis. The phase relations had been constructed. Five binary compounds, five tie lines and six three-phase regions were determined in this system. The possible component regions for ZnO single crystal flux growth were discussed. The phase diagram of Zn{sub 4}V{sub 2}O{sub 9}-ZnWO{sub 4} pseudo-binary system from 740 deg. C to 1300 deg. C was also determined through XRD and differential thermal analysis (DTA) methods. DTA results indicated this system was a eutectic system, and the eutectic temperature was 880 deg. C and eutectic point component was 78 mol% Zn{sub 4}V{sub 2}O{sub 9} and 22 mol% ZnWO{sub 4}. The compounds composed of 78 mol% Zn{sub 4}V{sub 2}O{sub 9} and 22 mol% ZnWO{sub 4} might be suitable flux for ZnO crystal growth.

  15. Monthly Sea Surface Salinity and Freshwater Flux Monitoring

    Science.gov (United States)

    Ren, L.; Xie, P.; Wu, S.

    2017-12-01

    Taking advantages of the complementary nature of the Sea Surface Salinity (SSS) measurements from the in-situ (CTDs, shipboard, Argo floats, etc.) and satellite retrievals from Soil Moisture Ocean Salinity (SMOS) satellite of the European Space Agency (ESA), the Aquarius of a joint venture between US and Argentina, and the Soil Moisture Active Passive (SMAP) of national Aeronautics and Space Administration (NASA), a technique is developed at NOAA/NCEP/CPC to construct an analysis of monthly SSS, called the NOAA Blended Analysis of Sea-Surface Salinity (BASS). The algorithm is a two-steps approach, i.e. to remove the bias in the satellite data through Probability Density Function (PDF) matching against co-located in situ measurements; and then to combine the bias-corrected satellite data with the in situ measurements through the Optimal Interpolation (OI) method. The BASS SSS product is on a 1° by 1° grid over the global ocean for a 7-year period from 2010. Combined with the NOAA/NCEP/CPC CMORPH satellite precipitation (P) estimates and the Climate Forecast System Reanalysis (CFSR) evaporation (E) fields, a suite of monthly package of the SSS and oceanic freshwater flux (E and P) was developed to monitor the global oceanic water cycle and SSS on a monthly basis. The SSS in BASS product is a suite of long-term SSS and fresh water flux data sets with temporal homogeneity and inter-component consistency better suited for the examination of the long-term changes and monitoring. It presents complete spatial coverage and improved resolution and accuracy, which facilitates the diagnostic analysis of the relationship and co-variability among SSS, freshwater flux, mixed layer processes, oceanic circulation, and assimilation of SSS into global models. At the AGU meeting, we will provide more details on the CPC salinity and fresh water flux data package and its applications in the monitoring and analysis of SSS variations in association with the ENSO and other major climate

  16. Atmospheric lepton fluxes

    Directory of Open Access Journals (Sweden)

    Gaisser Thomas K.

    2015-01-01

    Full Text Available This review of atmospheric muons and neutrinos emphasizes the high energy range relevant for backgrounds to high-energy neutrinos of astrophysical origin. After a brief historical introduction, the main distinguishing features of atmospheric νμ and νe are discussed, along with the implications of the muon charge ratio for the νµ / ν̅µ ratio. Methods to account for effects of the knee in the primary cosmic-ray spectrum and the energy-dependence of hadronic interactions on the neutrino fluxes are discussed and illustrated in the context of recent results from IceCube. A simple numerical/analytic method is proposed for systematic investigation of uncertainties in neutrino fluxes arising from uncertainties in the primary cosmic-ray spectrum/composition and hadronic interactions.

  17. NEUTRON FLUX INTENSITY DETECTION

    Science.gov (United States)

    Russell, J.T.

    1964-04-21

    A method of measuring the instantaneous intensity of neutron flux in the core of a nuclear reactor is described. A target gas capable of being transmuted by neutron bombardment to a product having a resonance absorption line nt a particular microwave frequency is passed through the core of the reactor. Frequency-modulated microwave energy is passed through the target gas and the attenuation of the energy due to the formation of the transmuted product is measured. (AEC)

  18. Flux canceling in three-dimensional radiative magnetohydrodynamic simulations

    Science.gov (United States)

    Thaler, Irina; Spruit, H. C.

    2017-05-01

    We aim to study the processes involved in the disappearance of magnetic flux between regions of opposite polarity on the solar surface using realistic three-dimensional (3D) magnetohydrodynamic (MHD) simulations. "Retraction" below the surface driven by magnetic forces is found to be a very effective mechanism of flux canceling of opposite polarities. The speed at which flux disappears increases strongly with initial mean flux density. In agreement with existing inferences from observations we suggest that this is a key process of flux disappearance within active complexes. Intrinsic kG strength concentrations connect the surface to deeper layers by magnetic forces, and therefore the influence of deeper layers on the flux canceling process is studied. We do this by comparing simulations extending to different depths. For average flux densities of 50 G, and on length scales on the order of 3 Mm in the horizontal and 10 Mm in depth, deeper layers appear to have only a mild influence on the effective rate of diffusion.

  19. Flux-line-cutting losses in type-II superconductors

    International Nuclear Information System (INIS)

    Clem, J.R.

    1982-01-01

    Energy dissipation associated with flux-line cutting (intersection and cross-joining of adjacent nonparallel vortices) is considered theoretically. The flux-line-cutting contribution to the dissipation per unit volume, arising from mutual annihilation of transverse magnetic flux, is identified as J/sub parallel/xE/sub parallel/, where J/sub parallel/ and E/sub parallel/ are the components of the current density and the electric field parallel to the magnetic induction. The dynamical behavior of the magnetic structure at the flux-line-cutting threshold is shown to be governed by a special critical-state model similar to that proposed by previous authors. The resulting flux-line-cutting critical-state model, characterized in planar geometry by a parallel critical current density J/sub c/parallel or a critical angle gradient k/sub c/, is used to calculate predicted hysteretic ac flux-line-cutting losses in type-II superconductors in which the flux pinning is weak. The relation of the theory to previous experiments is discussed

  20. Analysis of trends between solar wind velocity and energetic electron fluxes at geostationary orbit using the reverse arrangement test

    Science.gov (United States)

    Aryan, Homayon; Boynton, Richard J.; Walker, Simon N.

    2013-02-01

    A correlation between solar wind velocity (VSW) and energetic electron fluxes (EEF) at the geosynchronous orbit was first identified more than 30 years ago. However, recent studies have shown that the relation between VSW and EEF is considerably more complex than was previously suggested. The application of process identification technique to the evolution of electron fluxes in the range 1.8 - 3.5 MeV has also revealed peculiarities in the relation between VSW and EEF at the geosynchronous orbit. It has been revealed that for a constant solar wind density, EEF increase with VSW until a saturation velocity is reached. Beyond the saturation velocity, an increase in VSW is statistically not accompanied with EEF enhancement. The present study is devoted to the investigation of saturation velocity and its dependency upon solar wind density using the reverse arrangement test. In general, the results indicate that saturation velocity increases as solar wind density decreases. This implies that solar wind density plays an important role in defining the relationship between VSW and EEF at the geosynchronous orbit.

  1. Physics of magnetic flux ropes

    Science.gov (United States)

    Russell, C. T.; Priest, E. R.; Lee, L. C.

    The present work encompasses papers on the structure, waves, and instabilities of magnetic flux ropes (MFRs), photospheric flux tubes (PFTs), the structure and heating of coronal loops, solar prominences, coronal mass ejections and magnetic clouds, flux ropes in planetary ionospheres, the magnetopause, magnetospheric field-aligned currents and flux tubes, and the magnetotail. Attention is given to the equilibrium of MFRs, resistive instability, magnetic reconnection and turbulence in current sheets, dynamical effects and energy transport in intense flux tubes, waves in solar PFTs, twisted flux ropes in the solar corona, an electrodynamical model of solar flares, filament cooling and condensation in a sheared magnetic field, the magnetopause, the generation of twisted MFRs during magnetic reconnection, ionospheric flux ropes above the South Pole, substorms and MFR structures, evidence for flux ropes in the earth magnetotail, and MFRs in 3D MHD simulations.

  2. Densitometric tomography using the measurement of muon flux

    Science.gov (United States)

    Hivert, F.; Busto, J.; Brunner, J.; Salin, P.; Gaffet, S.

    2013-12-01

    The knowledge of the subsurface properties is essentially obtained by geophysical methods, e.g. seismic imaging, electric prospection or gravimetry. The present work develops a recent method to investigate the in situ density of rocks using atmospheric the muon flux measurement , its attenuation depending on the rock density and thickness. This new geophysical technique have been mainly applied in volcanology (Lesparre N., 2011) using scintillator detectors. The present project (T2DM2) aims to realize underground muons flux measurements in order to characterizing the rock massif density variations above the LSBB underground research facility in Rustrel (France). The muon flux will be measure with a new Muon telescope instrumentation using Micromegas detectors in Time Projection Chambers (TPC) configuration. The first step of the work presented considers the muon flux simulation using the Gaisser model, for the interactions between muons and atmospheric particles, and the MUSIC code (Kudryavtsev V. A., 2008) for the muons/rock interactions. The results show that the muon flux attenuation caused by density variations are enough significant to be observed until around 500 m depth and for period of time in the order of one month. Such a duration scale and depth of investigation is compatible with the duration of the water transfer processes involved within the Karst unsaturated zone where LSBB is located. Our work now concentrates on the optimization of the spatial distribution of detectors that will be deployed in future.

  3. Enhancement of magnetic flux distribution in a DC superconducting electric motor

    International Nuclear Information System (INIS)

    Hamid, N A; Ewe, L S; Chin, K M

    2013-01-01

    Most motor designs require an air gap between the rotor and stator to enable the armature to rotate freely. The interaction of magnetic flux from rotor and stator within the air gap will provide the thrust for rotational motion. Thus, the understanding of magnetic flux in the vicinity of the air gap is very important to mathematically calculate the magnetic flux generated in the area. In this work, a finite element analysis was employed to study the behavior of the magnetic flux in view of designing a synchronous DC superconducting electric motor. The analysis provides an ideal magnetic flux distribution within the components of the motor. From the flux plot analysis, it indicates that flux losses are mainly in the forms of leakage and fringe effect. The analysis also shows that the flux density is high at the area around the air gap and the rotor. The high flux density will provide a high force area that enables the rotor to rotate. In contrast, the other parts of the motor body do not show high flux density indicating low distribution of flux. Consequently, a bench top model of a DC superconducting motor was developed where by motor with a 2-pole type winding was chosen. Each field coil was designed with a racetrack-shaped double pancake wound using DI-BSCCO Bi-2223 superconducting tapes. The performance and energy efficiency of the superconducting motor was superior when compared to the conventional motor with similar capacity.

  4. Flux Trapping Properties of Bulk HIGH-TC Superconductors in Static Field-Cooling Magnetization

    Science.gov (United States)

    Deng, Z.; Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M.

    2013-06-01

    The trapping process and saturation effect of trapped magnetic flux of bulk high-temperature superconductors by static field-cooling magnetization (FCM) are reported in the paper. With a cryogenic Bell Hall sensor attached on the center of the bulk surface, the synchronous magnetic signals were recorded during the whole magnetization process. It enables us to know the flux trapping behavior since the removal of the excitation field, as well as the subsequent flux relaxation phenomenon and the flux dissipation in the quench process of the bulk sample. With the help of flux mapping techniques, the relationship between the trapped flux and the applied field was further investigated; the saturation effect of trapped flux was discussed by comparing the peak trapped field and total magnetic flux of the bulk sample. These studies are useful to understand the basic flux trapping properties of bulk superconductors.

  5. Depicting CH4 fluxes and drivers dynamics

    Science.gov (United States)

    Dengel, S.; Billesbach, D. P.; Hughes, H.; Humphreys, E.; Lee, J.; Noormets, A.; Verfaillie, J. G.

    2016-12-01

    Since the advancement in CH4 eddy covariance flux measurements, monitoring of CH4 emissions is becoming more widespread. Since CH4 fluxes are not as predictable or as easily interpretable as CO2 fluxes, understanding their emission patterns often still challenging. As these are spatially (ecosystem and latitudinal) and temporal very divers and often event based, a better understanding or interpretation of results is required. An improvement in understanding does also increase the reliability of gap-filling methods as annual greenhouse gas budgets rely on high quality data. There are generalised additive models (Wood 2001) that can easily be applied to sites, models where a relationship between the response variable, in this case CH4 and explanatory variables (drivers) is established. Relevant for CH4flux dynamics are the smoothing function that is applied, where each predictor variable is separated into sections and a polynomial function fitted. On the one hand such models are rarely used as they are difficult to interpret since no parameter values are retuned. On the other hand, such models are very good for prediction and explanatory analysis in estimating the functional nature of a response. Applying such models to CH4 eddy flux data does improve our understanding of the dynamics of CH4 emissions and the respective meteorological drivers. Furthermore, such models combined with tree models (interactions between the explanatory variables), can visualise precise dynamics and easily applied to individual sites. These models are simple tools in understanding of these complex fluxes, as they can include a variety of drivers, and their relevance tested by the model. Model input variables should be as independent as possible (avoiding cross-correlation), avoiding redundant inputs, as models should follow the principle of parsimony of being simple but not too simple. Wood SN (2001). mgcv: GAMs and generalized ridge regression for R. R news.

  6. Design and analysis of a 3D-flux flux-switching permanent magnet machine with SMC cores and ferrite magnets

    OpenAIRE

    Chengcheng Liu; Youhua Wang; Gang Lei; Youguang Guo; Jianguo Zhu

    2017-01-01

    Since permanent magnets (PM) are stacked between the adjacent stator teeth and there are no windings or PMs on the rotor, flux-switching permanent magnet machine (FSPMM) owns the merits of good flux concentrating and robust rotor structure. Compared with the traditional PM machines, FSPMM can provide higher torque density and better thermal dissipation ability. Combined with the soft magnetic composite (SMC) material and ferrite magnets, this paper proposes a new 3D-flux FSPMM (3DFFSPMM). The...

  7. Determination of solar proton fluxes and energies at high solar latitudes by UV radiation measurements