WorldWideScience

Sample records for bulk density analysis

  1. Bulk density estimation using a 3-dimensional image acquisition and analysis system

    Directory of Open Access Journals (Sweden)

    Heyduk Adam

    2016-01-01

    Full Text Available The paper presents a concept of dynamic bulk density estimation of a particulate matter stream using a 3-d image analysis system and a conveyor belt scale. A method of image acquisition should be adjusted to the type of scale. The paper presents some laboratory results of static bulk density measurements using the MS Kinect time-of-flight camera and OpenCV/Matlab software. Measurements were made for several different size classes.

  2. Non-destructive image analysis of soil surface porosity and bulk density dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Pires, L.F., E-mail: lfpires@uepg.b [Laboratory of Soil Physics and Environmental Sciences, State University of Ponta Grossa, UEPG, C.E.P. 84.030-900, Ponta Grossa, PR (Brazil); Cassaro, F.A.M. [Laboratory of Soil Physics and Environmental Sciences, State University of Ponta Grossa, UEPG, C.E.P. 84.030-900, Ponta Grossa, PR (Brazil); Bacchi, O.O.S.; Reichardt, K. [Laboratory of Soil Physics, Center for Nuclear Energy in Agriculture, USP/CENA, C.P. 96, C.E.P. 13.400-970, Piracicaba, SP (Brazil)

    2011-04-15

    A gamma-ray computed tomography (CT) scanner was used to evaluate changes in the structure of clayey soil samples with surface compaction submitted to wetting and drying (W-D) cycles. The obtained results indicate that W-D cycles promoted an increasing of about 10% in soil porosity with a decreasing of about 6% in soil bulk density of this compacted region. With the use of the CT it was also possible to define the thickness of the compacted region that in our case was of about 8.19 mm. This last information is very important, for instance, to estimate hydraulic parameters in infiltration models. Finally, CT analysis showed that the compacted region remained at the surface samples, even after the application of the W-D cycles. -- Research highlights: {yields} Gamma-ray tomography allowed non-destructive analysis of soil bulk density and porosity changes. {yields} Soil porosity increased about 10% with the wetting and drying cycles. {yields} Soil bulk density in the compacted region decreased about 6% with the wetting and drying cycles. {yields} Detailed bulk density and porosity analysis changes were obtained for layers of 1.17 mm.

  3. Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis

    CERN Document Server

    Kishne, Andrea Sz; Chang, Hung-Chih; Kish, Laszlo B

    2007-01-01

    Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified re...

  4. Effects of Y211 phase contents on the critical current density Jc and microstructural analysis in YBCO bulk superconductors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    YBCO bulk superconductors were prepared by the solid state reaction and top-seed-melt-textured growth (TSMTG) process. By using the AC susceptibility measurement, the critical transition temperature Tc of samples is 91.5 K for the highest value, and the transition width ?Tc is less than 1 K. The highest magnetization critical current densities Jc achieved 106 A/cm2 under 5 T at 10 K and 1.35?104 A/cm2 under 2 T at 70 K (H//c), respectively. The results combining the SEM observation indicate that doping of Y211 particles is more effective in improving the growth quality of melt-textured YBCO superconductor and in reducing the micro-cracks of specimens. Doping of Y2O3 powder forms the rod-shaped Y211 particles, but doping of Y211 particles directly to matrix materials forms the spherical Y211 particles mainly. Combining the microstructures with Jc measurements shows that the interfaces are most important on flux bundle pinning, in which the gradient of free energy is larger than that of other place between the Y211 particles and the Y123 matrix materials.

  5. Bulk density - RTD results and status of the standardisation

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, T.; Hartmann, H. [Technologie- und Foerderzentrum fuer Nachwachsende Rohstoffe - TFZ, Straubing (Germany); Daugbjerg Jensen, P. [Royal Veterinary and Agricultural University, Vejle (Denmark). Danish Centre for Forest, Landscape and Planning - DFLRI; Temmerman, M.; Rabier, F. [CRA, Gembloux (Belgium). Department Genie Rural; Jirjis, R.; Burvall, J. [Swedish University of Agricultural Sciences, Uppsala (Sweden). Department of Bioenergy; Hersener, J.L. [Ingenieurbuero HERSENER, Wiesendangen (Switzerland); Rathbauer, J. [Bundesanstalt fuer Landtechnik - BLT, Wieselburg (Austria)

    2004-07-01

    Bulk density is an important property for determining storage and transportation room demands and for volume based payment of biofuels. It is also used for calculation of the energy density. Furthermore, bulk density influences the readings from many physical principles for rapid moisture content determination (e. g. microwave reflection method, time domain reflectometric or capacitive sensors [6]). Although bulk density is mostly regarded as an easily determinable parameter, the applied national and international standard methods are highly inconsistent in practice [1, 4, 8]. The goal of the here presented research was therefore to provide a sound knowledge basis for bulk density determination, which shall be used in the ongoing process of European biofuel standardisation. In particular the research focus was to determine the - effect of container size and shape in respect of different biofuels, - effect of shock impact and the - effect of moisture content (as received) on measured bulk density (dry basis). (orig.)

  6. Phobos' Low Bulk Density: Evidence Against a Capture Origin?

    Science.gov (United States)

    Dalle Ore, C.; Pajola, M.; Lazzarin, M.; Roush, T. L.; Cruikshank, D. P.; Pendleton, Y. J.; Carli, C.; Bertini, I.; Magrin, S.; La Forgia, F.; Barbieri, C.

    2014-12-01

    Phobos' low density of 1.876 ± 0.02 g/cm3 (Andert et al., 2010, Witasse et al., 2013, Paetzold et al., 2013) supports its formation from a disk of debris (Peale 2007). The disk would either be a remnant of the formation of Mars (Safronov et al., 1986) or the result of a collision between Mars and a large body (Craddock 1994, 2011; Singer 2007). Within this scenario a large interior porosity would be responsible for the low density of the re-accreted material forming Phobos. Thermal emission spectra of Phobos suggest an ultramafic composition with the presence of phyllosilicates and feldspathoids in some regions (Giuranna et al., 2011), consistent with Phobos' in situ formation (Giuranna et al., 2011). However, the 0.3-4.0 μm surface spectra taken from multiple areas of the body in more than 43 years of observations (Duxbury et al., 2013), show physical characteristics similar to low-albedo asteroids such as C-type (Masursky et al., 1972, Pang et al., 1980) or D-type (Murchie 1999, Rivkin et al., 2002, Lynch et al., 2007, Pajola et al., 2012). They argue in favor of an asteroidal capture scenario that could be explained by binary asteroid dissociation (Landis 2009) or by collisional capture in the Martian orbital region (Pajola et al., 2012). Finally recent work by Schmedemann et al., (2014) indicates Phobos' surface to be ~ 4.3 - 3.7 Ga, dating back to a period where there was an intensification in the number of impactors in the inner Solar System (Gomes et al., 2005), and supporting both the in-situ and the capture scenario. Pajola et al. (2013) match the surface reflectance of Phobos from 0.4 to 4.0 μm with a mineralogical model composed of a mixture of Tagish Lake meteorite (TL) and Pyroxene Glass (PM80). Based on the published model, we adopted the weighted TL and PM80 densities to investigate if the low bulk density of Phobos could conform with these components reconciling both inner properties and surface spectra. While the TL density is available from

  7. Bulk Density of Comet 9P/Tempel 1 Based on Orbital and Rotational Nongravitational Effects

    Science.gov (United States)

    Samarasinha, Nalin H.; Belton, M.; Farnham, T.; Gutierrez, P.; Mueller, B.; Chesley, S.

    2009-09-01

    The accurate determination of bulk densities of cometary nuclei provides a strong indicator of their interior structure and will furnish insights into the conditions in the early solar system. The primary technique to determine cometary bulk densities is by correlating the secular orbital changes of the comet with the corresponding forces due to outgassing. However, significant uncertainties persist in these determinations as the accurate assessment of forces due to outgassing is difficult. Davidsson et al. (2007) derived a bulk density of 200-700 kg m-3 for comet 9P/Tempel 1 based on the orbital nongravitational forces. Richardson and colleagues (e.g,, Richardson et al. 2007) independently determined a density of 200-1000 kg m-3 for comet 9P/Tempel 1 based on the analysis of the ejecta fallback caused by the impactor of the Deep Impact mission. These density determinations based on widely different techniques yield consistent results; however, the allowed density range is relatively large. A simultaneous modeling of orbital and rotational changes in 9P/Tempel 1 is expected to yield more constraining results for the bulk density. Accurate determinations of the rotational changes (Belton et al. 2009) and the localized activity (cf. Farnham et al. 2007, Feaga et al. 2007, Schleicher 2006) of comet 9P/Tempel 1 allow us to simultaneously model the orbital and rotational changes caused by outgassing in a self-consistent manner. Initial results from this study will be presented at the meeting. We thank NASA Outer Planets Research Program. References: Belton, M.J.S. et al. 2009. Icarus, in preparation. Davidsson, B.J.R. et al. 2007, Icarus, 187, 306-320. Farnham, T.L. et al. 2007. Icarus, 187, 26-40. Feaga, L.M. et al. 2007. Icarus, 190, 345-356. Richardson, J.E. et al. 2007. Icarus, 190, 357-390. Schleicher D.G. 2006. Icarus, 181, 442-457.

  8. Bulk Density Adjustment of Resin-Based Equivalent Material for Geomechanical Model Test

    Directory of Open Access Journals (Sweden)

    Pengxian Fan

    2015-01-01

    Full Text Available An equivalent material is of significance to the simulation of prototype rock in geomechanical model test. Researchers attempt to ensure that the bulk density of equivalent material is equal to that of prototype rock. In this work, barite sand was used to increase the bulk density of a resin-based equivalent material. The variation law of the bulk density was revealed in the simulation of a prototype rock of a different bulk density. Over 300 specimens were made for uniaxial compression test. Test results indicated that the substitution of quartz sand by barite sand had no apparent influence on the uniaxial compressive strength and elastic modulus of the specimens but can increase the bulk density, according to the proportional coarse aggregate content. An ideal linearity was found in the relationship between the barite sand substitution ratio and the bulk density. The relationship between the bulk density and the usage of coarse aggregate and barite sand was also presented. The test results provided an insight into the bulk density adjustment of resin-based equivalent materials.

  9. Links between matrix bulk density, macropore characteristics and hydraulic behavior of soils

    DEFF Research Database (Denmark)

    Katuwal, Sheela; Møldrup, Per; Lamandé, Mathieu

    2013-01-01

    The relationship of soil bulk density with the hydraulic behavior of soil and the role of macropores in preferential flow and transport has been extensively studied in literatures. Yet, the influence of soil structural heterogeneity as simultaneous variation of bulk density and macropore characte...

  10. EFFECT OF MOISTURE CONTENT AND PARTICLE SIZE ON BULK DENSITY, POROSITY, PARTICLE DENSITY AND COEFFICIENT OF FRICTION OF COIR PITH

    Directory of Open Access Journals (Sweden)

    Dr.I.Neethi Manickam,

    2011-04-01

    Full Text Available Coir pith can be used as fuel in loose form or in briquettes. Bulk density, coefficient of friction, porosity and particle density affects densification and combustion of coir pith. The moisture content and particle size ranges were 10.1 to 60.2%w.b. and 0.098 to 0.925mm respectively. Porosity was varied from 0.623 to 0.862 and the particle density was varied from 0.939 to 0.605 gm/cc for the above ranges of moisture content and particle size. Bulk density was in the range of 0.097 to 0.341gm/cc. The coefficient of friction against mild steel was in the range of 0.5043 to 0.6332. Models were developed to find out bulk density, porosity, particle density and coefficient of friction for different moisture content and particle size.

  11. STUDY ON THE BULK DENSITY OF HIGH CONSISTENCY PULP AND ENGINEERING APPLICATION IN THE BLEACHING TOWER

    Directory of Open Access Journals (Sweden)

    Ke-Fu Chen

    2011-02-01

    Full Text Available From experimental simulation of the process of high consistency pulp moving in a bleaching tower, the aerated bulk density and packed bulk density were measured and studied by using a self-made experimental system. The scattered experimental data – pressure p, and bulk density difference, which was between packed bulk density and aerated bulk density (ρ-ρ0 – were fitted by using Matlab software, and some good-fitting regression curves and equations were obtained. The results showed there was a break point W in the regression curves; within the range of pressure between zero and W the relationship between (ρ-ρ0 and p was a linear function, while for pressure between W and 70000 the relationship was a power function. To effectively meet with the bleaching response for the different kinds and different consistencies of pulp in the tower, by using the fitting regression equations combined with the expressions of average bulk density and pressure in the tower caused by gravity-driven pulp, two equations for average packed density ρa were deduced with the aim of deciding the maximum volume value of the tower, in agreement with the sizes of the towers presently used by major companies.

  12. Constraining the Bulk Density of 10m-Class Near-Earth Asteroid 2012 LA

    Science.gov (United States)

    Mommert, Michael; Hora, Joseph; Farnocchia, Davide; Trilling, David; Chesley, Steve; Harris, Alan; Mueller, Migo; Smith, Howard

    2016-08-01

    The physical properties of near-Earth asteroids (NEAs) provide important hints on their origin, as well as their past physical and orbital evolution. Recent observations seem to indicate that small asteroids are different than expected: instead of being monolithic bodies, some of them instead resemble loose conglomerates of smaller rocks, so called 'rubble piles'. This is surprising, since self-gravitation is practically absent in these bodies. Hence, bulk density measurements of small asteroids, from which their internal structure can be estimated, provide unique constraints on asteroid physical models, as well as models for asteroid evolution. We propose Spitzer Space Telescope observations of 10 m-sized NEA 2012 LA, which will allow us to constrain the diameter, albedo, bulk density, macroporosity, and mass of this object. We require 30 hrs of Spitzer time to detect our target with a minimum SNR of 3 in CH2. In order to interpret our observational results, we will use the same analysis technique that we used in our successful observations and analyses of tiny asteroids 2011 MD and 2009 BD. Our science goal, which is the derivation of the target's bulk density and its internal structure, can only be met with Spitzer. Our observations will produce only the third comprehensive physical characterization of an asteroid in the 10m size range (all of which have been carried out by our team, using Spitzer). Knowledge of the physical properties of small NEAs, some of which pose an impact threat to the Earth, is of importance for understanding their evolution and estimating the potential of destruction in case of an impact, as well as for potential manned missions to NEAs for either research or potential commercial uses.

  13. Pedotransfer functions for Irish soils - estimation of bulk density (ρb) per horizon type

    Science.gov (United States)

    Reidy, B.; Simo, I.; Sills, P.; Creamer, R. E.

    2016-01-01

    Soil bulk density is a key property in defining soil characteristics. It describes the packing structure of the soil and is also essential for the measurement of soil carbon stock and nutrient assessment. In many older surveys this property was neglected and in many modern surveys this property is omitted due to cost both in laboratory and labour and in cases where the core method cannot be applied. To overcome these oversights pedotransfer functions are applied using other known soil properties to estimate bulk density. Pedotransfer functions have been derived from large international data sets across many studies, with their own inherent biases, many ignoring horizonation and depth variances. Initially pedotransfer functions from the literature were used to predict different horizon type bulk densities using local known bulk density data sets. Then the best performing of the pedotransfer functions were selected to recalibrate and then were validated again using the known data. The predicted co-efficient of determination was 0.5 or greater in 12 of the 17 horizon types studied. These new equations allowed gap filling where bulk density data were missing in part or whole soil profiles. This then allowed the development of an indicative soil bulk density map for Ireland at 0-30 and 30-50 cm horizon depths. In general the horizons with the largest known data sets had the best predictions, using the recalibrated and validated pedotransfer functions.

  14. Can Soil Penetration Resistance and Bulk Density Be Determined in a Single Undisturbed Sample?

    Directory of Open Access Journals (Sweden)

    Carolina Fernandes

    2015-06-01

    Full Text Available Soil quality indicators such as penetration resistance (PR and bulk density (BD are traditionally determined in a single undisturbed soil sample. The aim of this study was to assess the effect of PR measurements of undisturbed samples on the determination of BD in the same sample of two soils differing in clay contents. To this end, samples were collected from the 0.00-0.10 and 0.10-0.20 m layers of two soils of clayey and very clayey texture. Volumetric rings were used to collect a total of 120 undisturbed soil samples from each soil layer that were divided into two subsets containing 60 units each. One sample set, designated “perforated samples”, was used to determine PR and BD in the same undisturbed sample; the other, named “intact samples”, was used to determine BD only. Bulk density values for perforated and intact samples were compared by analysis of variance, using a completely randomized experimental design. Means were compared by the t-test at 5 %. The BD values for the clayey soil were similar in perforated and intact samples from the two layers. However, BD of the very clayey soil was lower in the perforated than in the intact samples at both depths. Therefore, PR and BD in clayey soils can be accurately determined in the same undisturbed sample whereas in very clayey soils, different samples are required for this purpose.

  15. PEDO-TRANSFER FUNCTIONS FOR ESTIMATING SOIL BULK DENSITY IN CENTRAL AMAZONIA

    Directory of Open Access Journals (Sweden)

    Henrique Seixas Barros

    2015-04-01

    Full Text Available Under field conditions in the Amazon forest, soil bulk density is difficult to measure. Rigorous methodological criteria must be applied to obtain reliable inventories of C stocks and soil nutrients, making this process expensive and sometimes unfeasible. This study aimed to generate models to estimate soil bulk density based on parameters that can be easily and reliably measured in the field and that are available in many soil-related inventories. Stepwise regression models to predict bulk density were developed using data on soil C content, clay content and pH in water from 140 permanent plots in terra firme (upland forests near Manaus, Amazonas State, Brazil. The model results were interpreted according to the coefficient of determination (R2 and Akaike information criterion (AIC and were validated with a dataset consisting of 125 plots different from those used to generate the models. The model with best performance in estimating soil bulk density under the conditions of this study included clay content and pH in water as independent variables and had R2 = 0.73 and AIC = -250.29. The performance of this model for predicting soil density was compared with that of models from the literature. The results showed that the locally calibrated equation was the most accurate for estimating soil bulk density for upland forests in the Manaus region.

  16. The effects of forward speed and depth of conservation tillage on soil bulk density

    Directory of Open Access Journals (Sweden)

    A Mahmoudi

    2015-09-01

    Full Text Available Introduction: In recent years, production techniques and equipment have been developed for conservation of tillage systems that have been adopted by many farmers. With proper management, overall yield averages for conventional and reduced tillage systems are nearly identical. Sometimes, field operations can be combined by connecting two or more implements. Combined operations reduce both fuel consumption, and time and labor requirements by eliminating at least one individual trip over the field. Light tillage, spraying, or fertilizing operations can be combined with either primary or secondary tillage or planting operations. Tillage helps seed growth and germination through providing appropriate conditions for soil to absorb sufficient temperature and humidity. Moreover, it helps easier development of root through reducing soil penetration resistance. Tillage is a time-consuming and expensive procedure. With the application of agricultural operations, we can save substantial amounts of fuel, time and energy consumption. Conservation tillage loosens the soil without turning, but by remaining the plant left overs, stems and roots. Bulk density reflects the soil’s ability to function for structural support, water and solute movement, and soil aeration. Bulk densities above thresholds indicate impaired function. Bulk density is also used to convert between weight and volume of soil. It is used to express soil physical, chemical and biological measurements on a volumetric basis for soil quality assessment and comparisons between management systems. This increases the validity of comparisons by removing the error associated with differences in soil density at the time of sampling. The aim of conservation tillage is to fix the soil structure. This investigation was carried out considering the advantages of conservation tillage and less scientific research works on imported conservation tillage devices and those which are made inside the country

  17. [Effects of tillage mode on black soil's penetration resistance and bulk density].

    Science.gov (United States)

    Chen, Xue-Wen; Zhang, Xiao-Ping; Liang, Ai-Zhen; Jia, Shu-Xia; Shi, Xiu-Huan; Fan, Ru-Qin; Wei, Shou-Cai

    2012-02-01

    Taking an eight-year field experiment site in Dehui County of Jilin Province, Northeast China as test object, this paper studied the effects of different tillage modes (no tillage and ploughing in autumn) on the penetration resistance and bulk density of black soil. No tillage increased the soil penetration resistance, especially at the soil depth of 2.5-17.5 cm. In the continuous cropping of maize and the rotation of maize-soybean, the maximum soil penetration resistance at planting zone under no tillage and ploughing in autumn was 2816 and 1931 kPa, and 2660 and 2051 kPa, respectively, which had no restriction on the crop growth. The curve of soil penetration resistance under ploughing in autumn changed with ridge shape, while that under no tillage changed less. Comparing with ploughing in autumn, no tillage increased the bulk density of 5-20 cm soil layer significantly. Under no tillage, the bulk density of 5-30 cm soil layer changed little, but under ploughing in autumn, soil bulk density increased gradually with increasing soil depth. There was no significant correlation between soil bulk density and soil penetration resistance.

  18. A Method for Determining Bulk Density, Material Density, and Porosity of Melter Feed During Nuclear Waste Vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Hilliard, Zachary J.; Hrma, Pavel R.

    2016-01-31

    Abstract Glass making efficiency largely depends on heat transfer to reacting glass batch (melter feed), which in turn is influenced by the bulk density (ρb) and porosity (Φ) as functions of temperature (T). Neither b(T) nor Φ(T) functions are readily accessible to direct measurement, but they can be determined based on monitoring the profile area of heated glass batch pellets and material density of batches quenched at various stages of conversion via pycnometry. For the determination of Φb, the bulk volume must be calculated as a function of temperature. This is done via a program constructed in MATLAB which takes an image of a pellet profile at a given temperature and calculates the volume of said pellet. The quenched density measured by pycnometry must be converted to the density at heat treatment temperature. This is done by taking into account the volume change due to thermal expansion/contraction.

  19. Comparing the density of states of binary Lennard-Jones glasses in bulk and film

    Science.gov (United States)

    Ghosh, Jayeeta; Faller, Roland

    2008-03-01

    We used Wang-Landau density of states Monte Carlo to study a binary Lennard-Jones glass-forming mixture in bulk and films between noninteracting walls. Thermodynamic properties are calculated using two different ensembles and film data are compared with the bulk. Bulk properties are in good agreement with previous simulations. We confirm the formation of a glass using various properties, e.g., energy, heat capacity, and pressure with temperature. We find a change in slope in the energy per particle and pressure as a function of temperature. We do not find any defined crystal structure. A higher glass transition temperature is found for the film.

  20. Specification of Density Functional Approximation by Radial Distribution Function of Bulk Fluid

    Institute of Scientific and Technical Information of China (English)

    ZHOUShi-Qi

    2002-01-01

    A systematic methodology is proposed to deal with the weighted density approximation version of classical density functional theory by employing the knowledge of radial distribution function of bulk fluid.The present methodology results from the concept of universality of the free energy density functional combined with the test particle method.It is shown that the new method is very accurate for the predictions of density distribution of a hard sphere fluid at different confining geometries.The physical foundation of the present methodology is also applied to the quantum density functional theory.

  1. Method for determining transport critical current densities and flux penetration depth in bulk superconductors

    Science.gov (United States)

    Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

    1992-01-01

    A contact-less method for determining transport critical current density and flux penetration depth in bulk superconductor material. A compressor having a hollow interior and a plunger for selectively reducing the free space area for distribution of the magnetic flux therein are formed of superconductor material. Analytical relationships, based upon the critical state model, Maxwell's equations and geometrical relationships define transport critical current density and flux penetration depth in terms of the initial trapped magnetic flux density and the ratio between initial and final magnetic flux densities whereby data may be reliably determined by means of the simple test apparatus for evaluating the current density and flux penetration depth.

  2. Bounds on the local energy density of holographic CFTs from bulk geometry

    Science.gov (United States)

    Fischetti, Sebastian; Hickling, Andrew; Wiseman, Toby

    2016-11-01

    The stress tensor is a basic local operator in any field theory; in the context of AdS/CFT, it is the operator which is dual to the bulk geometry itself. Here we exploit this feature by using the bulk geometry to place constraints on the local energy density in static states of holographic (2+1)-dimensional CFTs living on a closed (but otherwise generally curved) spatial geometry. We allow for the presence of a marginal scalar deformation, dual to a massless scalar field in the bulk. For certain vacuum states in which the bulk geometry is well-behaved at zero temperature, we find that the bulk equations of motion imply that the local energy density integrated over specific boundary domains is negative. In the absence of scalar deformations, we use the inverse mean curvature flow to show that if the CFT spatial geometry has spherical topology but non-constant curvature, the local energy density must be positive somewhere. This result extends to other topologies, but only for certain types of vacuum; in particular, for a generic toroidal boundary, the vacuum’s bulk dual must be the zero-temperature limit of a toroidal black hole.

  3. High critical current densities in bulk MgB{sub 2} fabricated using amorphous boron

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, Miryala; Kenta, Nozaki; Murakami, Masato [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, Tokyo 135-8548 (Japan); Koblischka, Michael R. [Institute of Experimental Physics, Saarland University, P.O. Box 151150, 66041 Saarbruecken (Germany)

    2015-10-15

    We prepared bulk MgB{sub 2} from high-purity commercial powders of Mg metal (99.9% purity) and amorphous B (99% purity) powders using a single-step solid state reaction at 775 C for varying sintering duration from 1 to 10 h in pure argon atmosphere. X-ray diffraction analysis showed that all the samples were single phase MgB{sub 2}. The magnetization measurements confirmed a sharp superconducting transition with T{sub c,onset} at around 38.2-38.8 K. The critical current density (J{sub c}) values for the MgB{sub 2} samples produced at 1 h sintering time is the highest one in all processed materials here. Scanning electron microscopy analyses indicated that the sintering time has a crucial influence on the grain size. As a result, the highest J{sub c} value of 270 kA cm{sup -2} at 20 K and self-field was achieved in the sample produced at 775 C for 1 h. Our results clearly demonstrate that the optimization of the sintering conditions is essential to improve the bulk MgB{sub 2} performance. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Specification of Density Functional Approximation by Radial Distribution Function of Bulk Fluid

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi

    2002-01-01

    A systematic methodology is proposed to deal with the weighted density approximation version of clas-sical density functional theory by employing the knowledge of radial distribution function of bulk fluid. The presentmethodology results from the concept of universality of the free energy density functional combined with the test particlemethod. It is shown that the new method is very accurate for the predictions of density distribution ofa hard sphere fluidat different confining geometries. The physical foundation of the present methodology is also applied to the quantumdensity functional theory.

  5. Bounds on the local energy density of holographic CFTs from bulk geometry

    CERN Document Server

    Fischetti, Sebastian; Wiseman, Toby

    2016-01-01

    The stress tensor is a basic local operator in any field theory; in the context of AdS/CFT, it is the operator which is dual to the bulk geometry itself. Here we exploit this feature by using the bulk geometry to place constraints on the local energy density in static states of holographic $(2+1)$-dimensional CFTs living on a closed (but otherwise generally curved) spatial geometry. We allow for the presence of a marginal scalar deformation, dual to a massless scalar field in the bulk. For certain vacuum states in which the bulk geometry is well-behaved at zero temperature, we find that the bulk equations of motion imply that the local energy density integrated over specific boundary domains is negative. In the absence of scalar deformations, we use the inverse mean curvature flow to show that if the CFT spatial geometry has spherical topology but non-constant curvature, the local energy density must be positive somewhere. This result extends to other topologies, but only for certain types of vacuum; in parti...

  6. Microwave Nondestructive Sensing of Moisture Content in Shelled Peanuts Independent of Bulk Density with Temperature Compensation

    Science.gov (United States)

    Dielectric methods for rapid and nondestructive sensing of moisture content in shelled peanuts from free-space measurement of attenuation and phase shift, and their corresponding dielectric properties at 10 GHz, are presented. These methods provide moisture content independent of bulk density and c...

  7. The Effect of Bulk Density on Emission Behavior of Soil at Microwave Frequencies

    Directory of Open Access Journals (Sweden)

    V. K. Gupta

    2011-01-01

    Full Text Available Dielectric constant and dielectric loss (ε′ and ε″ of different soil samples with bulk densities varying from 1.3 to 2.0 gm/cm3 are determined at a single microwave frequency 9.78 GHz and at temperature 37.0°C. Different bulk densities of same soil are achieved by filling the wave guide cell with an equal volume but a different mass of soil. Further, ε′ and ε″ of these soil samples are also estimated by semiempirical model and compared with the experimental results. The values of ε′ and ε″ increase as bulk density of the soil increases. In view of microwave remote sensing, the Fresnel reflectivity of soil is computed from the knowledge of the complex dielectric constant and the surface boundary condition. Using Kirchhoff’s reciprocity theorem the microwave emissivity is estimated from Fresnel reflectivity of the surface. It is observed that the microwave emission from the soil surface inhibits as bulk density of soil increases. Further, the roughness of soil surface has been taken into consideration in the emissivity computation and observed that the emissivity increases with increasing roughness of the soil surface.

  8. Microwave sensing of moisture content and bulk density in flowing grain

    Science.gov (United States)

    Moisture content and bulk density were determined from measurement of the dielectric properties of flowing wheat kernels at a single microwave frequency (5.8 GHz). The measuring system consisted of two high-gain microwave patch antennas mounted on opposite sides of rectangular chute and connected to...

  9. Laser ultrasonics for bulk-density distribution measurement on green ceramic tiles

    Science.gov (United States)

    Revel, G. M.; Cavuto, A.; Pandarese, G.

    2016-10-01

    In this paper a Laser Ultrasonics (LUT) system is developed and applied to measure bulk density distribution of green ceramic tiles, which are porous materials with low heat conductivity. Bulk density of green ceramic bodies is a fundamental parameter to be kept under control in the industrial production of ceramic tiles. The LUT system proposed is based on a Nd:YAG pulsed laser for excitation and an air-coupled electro-capacitive transducer for detection. The paper reports experimental apparent bulk-density measurements on white ceramic bodies after a calibration procedures. The performances observed are better than those previously achieved by authors using air-coupled ultrasonic probes for both emission and detection, allowing to reduce average uncertainty down to about ±6 kg/m3 (±0.3%), thanks to the increase in excitation efficiency and lateral resolution, while maintaining potential flexibility for on-line application. The laser ultrasonic procedure proposed is available for both on-line and off-line application. In this last case it is possible to obtain bulk density maps with high spatial resolution by a 2D scan without interrupting the production process.

  10. Soil resistivity over root area ratio, soil humidity, and bulk density: laboratory tests

    Science.gov (United States)

    Guastini, Enrico; Giambastiani, Yamuna; Preti, Federico

    2015-04-01

    Knowledge about root system distribution covers an important role in slope shallow stability stud-ies, as this factor grants an increase in soil geotechnical properties (soil cohesion and friction an-gle) and determines a different underground water circulation. Published studies (Amato et al., 2008 and 2011; Censini et al., 2014) about in situ application of ERT (Electrical Resistivity Tomo-graphy) analysis show how the root presence affects the measurable soil resistivity values, confirm-ing the suitability to investigate the application of such technique, aiming to estimate root density in soil with an indirect and non-invasive method. This study, laboratory-based and led on reconstructed samples in controlled condition, aim to find a correlation between the resistivity variations and the various factors that can affect them (humid-ity, bulk density, presence of foreign bodies, temperature). The tests involved a clay-loam soil (USDA classification) taken from Quaracchi (Florence, Italy), in an experimental fir-wood (Picea abies) owned by the Department of Agricultural, Food and For-estry System, Florence University, a previously chosen site for field ERT applications. The row ma-terial has been dried out in a lab stove, grounded and sieved at 2 mm, and then placed in a lexan box (30 x 20 x 20 cm) without compaction. Inside the sample have been inserted 3 series of 4 iron electrodes, insulated along the shaft and with the conductive end placed at three different depth: 2 cm from surface, in the middle of the sample and in contact with the bottom of the box; resistivity measures are conducted on the three levels using a Syscal R2 with electrodes connected in a dipole-dipole configuration. Root presence is simulated inserting bamboo spits (simple geometry, replicable "R.A.R.") in varying number from 0 to 16 in every area between two contiguous electrodes. The tests are repeated in time, monitoring the natural variations in humidity (evapotranspiration) and bulk

  11. Bulk viscosity of strange quark matter in density dependent quark mass model

    Indian Academy of Sciences (India)

    J D Anand; N Chandrika Devi; V K Gupta; S Singh

    2000-05-01

    We have studied the bulk viscosity of strange quark matter in the density dependent quark mass model (DDQM) and compared results with calculations done earlier in the MIT bag model where , masses were neglected and first order interactions were taken into account. We find that at low temperatures and high relative perturbations, the bulk viscosity is higher by 2 to 3 orders of magnitude while at low perturbations the enhancement is by 1–2 order of magnitude as compared to earlier results. Also the damping time is 2–3 orders of magnitude lower implying that the star reaches stability much earlier than in MIT bag model calculations.

  12. Bulk density and compaction behavior of knife mill chopped switchgrass, wheat straw, and corn stover.

    Science.gov (United States)

    Chevanan, Nehru; Womac, Alvin R; Bitra, Venkata S P; Igathinathane, C; Yang, Yuechuan T; Miu, Petre I; Sokhansanj, Shahab

    2010-01-01

    Bulk density of comminuted biomass significantly increased by vibration during handling and transportation, and by normal pressure during storage. Compaction characteristics affecting the bulk density of switchgrass, wheat straw, and corn stover chopped in a knife mill at different operating conditions and using four different classifying screens were studied. Mean loose-filled bulk densities were 67.5+/-18.4 kg/m(3) for switchgrass, 36.1+/-8.6 kg/m(3) for wheat straw, and 52.1+/-10.8 kg/m(3) for corn stover. Mean tapped bulk densities were 81.8+/-26.2 kg/m(3) for switchgrass, 42.8+/-11.7 kg/m(3) for wheat straw, and 58.9+/-13.4 kg/m(3) for corn stover. Percentage changes in compressibility due to variation in particle size obtained from a knife mill ranged from 64.3 to 173.6 for chopped switchgrass, 22.2-51.5 for chopped wheat straw and 42.1-117.7 for chopped corn stover within the tested consolidation pressure range of 5-120 kPa. Pressure and volume relationship of chopped biomass during compression with application of normal pressure can be characterized by the Walker model and Kawakita and Ludde model. Parameter of Walker model was correlated to the compressibility with Pearson correlation coefficient greater than 0.9. Relationship between volume reduction in chopped biomass with respect to number of tappings studied using Sone's model indicated that infinite compressibility was highest for chopped switchgrass followed by chopped wheat straw and corn stover. Degree of difficulty in packing measured using the parameters of Sone's model indicated that the chopped wheat straw particles compacted very rapidly by tapping compared to chopped switchgrass and corn stover. These results are very useful for solving obstacles in handling bulk biomass supply logistics issues for a biorefinery.

  13. Bulk Properties of Transition Metals: A Challenge for the Design of Universal Density Functionals.

    Science.gov (United States)

    Janthon, Patanachai; Luo, Sijie Andy; Kozlov, Sergey M; Viñes, Francesc; Limtrakul, Jumras; Truhlar, Donald G; Illas, Francesc

    2014-09-09

    Systematic evaluation of the accuracy of exchange-correlation functionals is essential to guide scientists in their choice of an optimal method for a given problem when using density functional theory. In this work, accuracy of one Generalized Gradient Approximation (GGA) functional, three meta-GGA functionals, one Nonseparable Gradient Approximation (NGA) functional, one meta-NGA, and three hybrid GGA functionals was evaluated for calculations of the closest interatomic distances, cohesive energies, and bulk moduli of all 3d, 4d, and 5d bulk transition metals that have face centered cubic (fcc), hexagonal closed packed (hcp), or body centered cubic (bcc) structures (a total of 27 cases). Our results show that including the extra elements of kinetic energy density and Hartree-Fock exchange energy density into gradient approximation density functionals does not usually improve them. Nevertheless, the accuracies of the Tao-Perdew-Staroverov-Scuseria (TPSS) and M06-L meta-GGAs and the MN12-L meta-NGA approach the accuracy of the Perdew-Burke-Ernzerhof (PBE) GGA, so usage of these functionals may be advisable for systems containing both solid-state transition metals and molecular species. The N12 NGA functional is also shown to be almost as accurate as PBE for bulk transition metals, and thus it could be a good choice for studies of catalysis given its proven good performance for molecular species.

  14. The influence of fibrous bed bulk density on the bed properties

    Directory of Open Access Journals (Sweden)

    Šećerov-Sokolović Radmila M.

    2003-01-01

    Full Text Available The mean properties of seven different fibrous materials and the properties of their different bed bulk densities were investigated. The morphology of the surface, size and geometry were measured by optical microscopy. The bed porosity was measured by the weighing method. The experimental bed permeability, in a high range of bulk density, was calculated from the values of the sanitary water pressure drop at a constant temperature of 15°C, since the data followed Darcy's law. The Reynolds number for a fibrous bed was calculated using a relation from the literature. The Reynolds number was less than 1 for all ranges of fluid velocity. Three empirical relations for fibrous bed permeability were used and compared with the experimental data. It was determined that the empirical data depended on the fiber diameter and fraction of solid in the bed. The relative error linearly increased with increasing fiber diameter.

  15. Bulk density of asteroid 243 Ida from the orbit of its satellite Dactyl

    Science.gov (United States)

    Belton, M.J.S.; Chapmant, C.R.; Thomas, P.C.; Davies, M.E.; Greenberg, R.; Klaasen, K.; Byrnes, D.; D'Amario, L.; Synnott, S.; Johnson, T.V.; McEwen, A.; Merline, W.J.; Davis, D.R.; Petit, J.-M.; Storrs, A.; Veverka, J.; Zellner, B.

    1995-01-01

    DURING its reconnaissance of the asteroid 243 Ida, the Galileo spacecraft returned images of a second object, 1993(243)1 Dactyl1 - the first confirmed satellite of an asteroid. Sufficient data were obtained on the motion of Dactyl to determine its orbit as a function of Ida's mass. Here we apply statistical and dynamical arguments to constrain the range of possible orbits, and hence the mass of Ida. Combined with the volume of Ida2, this yields a bulk density of 2.6??0.5 g cm-3. Allowing for the uncertainty in the porosity of Ida, this density range is consistent with a bulk chondritic composition, and argues against some (but not all) classes of meteoritic igneous rock types that have been suggested as compositionally representative of S-type asteroids like Ida.

  16. Kernel and bulk density changes due to moisture content, mechanical damage, and insect damage

    OpenAIRE

    Guo, Danping

    2015-01-01

    Corn (Zea Mays), is one of the major grain crops in the world and moisture content, mechanical damage and insect damage are three factors that affect its quality. The primary goal of this thesis was to investigate the effects of moisture content, mechanical damage and insect damage on kernel and bulk density of corn. The study was conducted using two corn hybrids, Pioneer 1352 and Pioneer 1221, that were grown on Purdue Agronomy Farm for Research and Education (ACRE), manually picked and shel...

  17. Estimating Leaf Bulk Density Distribution in a Tree Canopy Using Terrestrial LiDAR and a Straightforward Calibration Procedure

    Directory of Open Access Journals (Sweden)

    François Pimont

    2015-06-01

    Full Text Available Leaf biomass distribution is a key factor for modeling energy and carbon fluxes in forest canopies and for assessing fire behavior. We propose a new method to estimate 3D leaf bulk density distribution, based on a calibration of indices derived from T-LiDAR. We applied the method to four contrasted plots in a mature Quercus pubescens forest. Leaf bulk densities were measured inside 0.7 m-diameter spheres, referred to as Calibration Volumes. Indices were derived from LiDAR point clouds and calibrated over the Calibration Volume bulk densities. Several indices were proposed and tested to account for noise resulting from mixed pixels and other theoretical considerations. The best index and its calibration parameter were then used to estimate leaf bulk densities at the grid nodes of each plot. These LiDAR-derived bulk density distributions were used to estimate bulk density vertical profiles and loads and above four meters compared well with those assessed by the classical inventory-based approach. Below four meters, the LiDAR-based approach overestimated bulk densities since no distinction was made between wood and leaf returns. The results of our method are promising since they demonstrate the possibility to assess bulk density on small plots at a reasonable operational cost.

  18. Gamma-ray attenuation method as an efficient tool to investigate soil bulk density spatial variability

    Energy Technology Data Exchange (ETDEWEB)

    Pires, L.F., E-mail: lfpires@uepg.b [Laboratory of Soil Physics and Environmental Sciences, State University of Ponta Grossa, UEPG, C.E.P. 84.030-900 Ponta Grossa, PR (Brazil); Rosa, J.A. [Laboratory of Soil Physics, Agricultural Research Institute of Parana, IAPAR, C.E.P. 84.001-970 Ponta Grossa, PR (Brazil); Pereira, A.B. [Laboratory of Agrometeorology, State University of Ponta Grossa, UEPG, C.E.P. 84.030-900 Ponta Grossa, PR (Brazil); Arthur, R.C.J.; Bacchi, O.O.S. [Laboratory of Soil Physics, Center for Nuclear Energy in Agriculture, USP/CENA, C.E.P. 13.400-970 Piracicaba, SP (Brazil)

    2009-11-15

    The spatial variability of soil bulk density (rho{sub b}) was measured by using the volumetric ring method (VRM) and the gamma-ray attenuation method (GAM). Collimated radiation from 3.7 GBq of {sup 241}Am was used to evaluate the soil mass attenuation coefficient and its bulk density. Circular lead collimators were adjusted and aligned between source (D = 1, 2 and 3 mm) and detector (D = 4.5 mm). Results of GAM for average rho{sub b} provided good agreement with the corresponding values obtained gravimetrically. Variations in bulk density for different collimator dimensions can be attributed to multiple scattering after photons interaction with soil, mainly for 3 mm collimator size. The best result of rho{sub b} by the nuclear technique was obtained when rho{sub b} represents an average of the measurements for collimators of 1 and 2 mm. Another cause for the differences in rho{sub b} by GAM and VRM is the heterogeneity of soil when the collimated beam can interact with stones or large air-filled holes or channels present in the sample. Therefore, the pattern of spatial variability obtained by VRM was confirmed by GAM for all collimator sizes. This result is a good indication that GAM can be used with success to analyze soil spatial variability.

  19. Accurate bulk density determination of irregularly shaped translucent and opaque aerogels

    Science.gov (United States)

    Petkov, M. P.; Jones, S. M.

    2016-05-01

    We present a volumetric method for accurate determination of bulk density of aerogels, calculated from extrapolated weight of the dry pure solid and volume estimates based on the Archimedes' principle of volume displacement, using packed 100 μm-sized monodispersed glass spheres as a "quasi-fluid" media. Hard particle packing theory is invoked to demonstrate the reproducibility of the apparent density of the quasi-fluid. Accuracy rivaling that of the refractive index method is demonstrated for both translucent and opaque aerogels with different absorptive properties, as well as for aerogels with regular and irregular shapes.

  20. Effects of Soil Bulk Density on Gas Transport Parameters and Pore-Network Properties across a Sandy Field Site

    DEFF Research Database (Denmark)

    Masis Melendez, Federico; de Jonge, Lis Wollesen; Chamindu, T K K Deepagoda

    2015-01-01

    The gas diffusion coefficient, air permeability, and their interrelations with air-filled porosity are crucial for characterization of diffusive and convective transport of gases in soils. Variations in soil bulk density can affect water retention, air-filled pore space, pore tortuosity...... to quantify gas transport and water retention processes across the field. Results revealed significant negative correlations between all six parameters and soil bulk density. Areas with higher bulk density exhibited reduced air-filled porosity and lower diffusivity- and air permeability-based connectivity...... and connectivity, and hence control gas diffusion and air permeability. Considering 86 undisturbed core samples with variable bulk density that were extracted on a grid from the top layer of a sandy field, the effects of soil bulk density on gas transport parameters and the soil water characteristic were...

  1. Critical current densities in Ag-added bulk MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, M., E-mail: miryala1@shibaura-it.ac.jp [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Inoue, K. [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Koblischka, M.R. [Experimental Physics, Saarland University, Campus C 6 3, 66123 Saarbrücken (Germany); Murakami, M. [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan)

    2015-11-15

    Highlights: • Bulk MgB{sub 2} samples with Ag contents of 0–10 wt% were sintered at 775 °C for 3 h. • Magnetization measurements showed a sharp superconducting transition with T{sub c} (onset) around 38.5–38.7 K. • Atomic force microscopy indicated that Ag-based MgB{sub 2} particles are of nanometer size. • The sample with 4 wt% Ag addition exhibited the highest J{sub c} of 400 kA/cm{sup 2} at 10 K and self field. - Abstract: In previous studies, we found that bulk MgB{sub 2} contained numerous voids in various shapes and sizes. With the aim of improving the critical current density as well as the mechanical performance of the disk-shaped MgB{sub 2} bulk superconductors, we added Ag and optimized the processing conditions. The samples with varied Ag content from 0, 2, 4, 6, to 10 wt% were synthesized in pure Ar atmosphere. Microstructural observation by scanning electron microscopy confirmed that metallic Ag particles are embedded in the void regions. Furthermore, atomic force microscopy indicated that silver-based MgB{sub 2} particles are of nanometer size. As a result, the critical current density (J{sub c}) values were improved with Ag addition as compared to pure MgB{sub 2} bulk. The sample with 4 wt% Ag addition exhibited the highest J{sub c} of 293 kA/cm{sup 2} at 20 K and self field. The respective J{sub c} values at 10 K were 400 kA/cm{sup 2}, 300 kA/cm{sup 2}, and 100 kA/cm{sup 2} in self field, 1 T and 2 T. These values are the highest record values so far reported in bulk MgB{sub 2} materials.

  2. 3D-Laser-Scanning Technique Applied to Bulk Density Measurements of Apollo Lunar Samples

    Science.gov (United States)

    Macke, R. J.; Kent, J. J.; Kiefer, W. S.; Britt, D. T.

    2015-01-01

    In order to better interpret gravimetric data from orbiters such as GRAIL and LRO to understand the subsurface composition and structure of the lunar crust, it is import to have a reliable database of the density and porosity of lunar materials. To this end, we have been surveying these physical properties in both lunar meteorites and Apollo lunar samples. To measure porosity, both grain density and bulk density are required. For bulk density, our group has historically utilized sub-mm bead immersion techniques extensively, though several factors have made this technique problematic for our work with Apollo samples. Samples allocated for measurement are often smaller than optimal for the technique, leading to large error bars. Also, for some samples we were required to use pure alumina beads instead of our usual glass beads. The alumina beads were subject to undesirable static effects, producing unreliable results. Other investigators have tested the use of 3d laser scanners on meteorites for measuring bulk volumes. Early work, though promising, was plagued with difficulties including poor response on dark or reflective surfaces, difficulty reproducing sharp edges, and large processing time for producing shape models. Due to progress in technology, however, laser scanners have improved considerably in recent years. We tested this technique on 27 lunar samples in the Apollo collection using a scanner at NASA Johnson Space Center. We found it to be reliable and more precise than beads, with the added benefit that it involves no direct contact with the sample, enabling the study of particularly friable samples for which bead immersion is not possible

  3. Feasibility and limitations of bulk density assignment in MRI for head and neck IMRT treatment planning.

    Science.gov (United States)

    Chin, Alexander L; Lin, Alexander; Anamalayil, Shibu; Teo, Boon-Keng Kevin

    2014-01-01

    Head and neck cancers centered at the base of skull are better visualized on MRI than on CT. The purpose of this investigation was to investigate the accuracy of bulk density assignment in head and neck intensity-modulated radiation therapy (IMRT) treatment plan optimization. Our study investigates dose calculation differences between density-assigned MRI and CT, and identifies potential limitations related to dental implants and MRI geometrical distortion in the framework of MRI-only-based treatment planning. Bulk density assignment was performed and applied onto MRI to generate three MRI image sets with increasing levels of heterogeneity for seven patients: 1) MRIW: all water-equivalent; 2) MRIW+B: included bone with density of 1.53 g/cm3; and 3) MRIW+B+A: included bone and air. Using identical planning and optimization parameters, MRI-based IMRT plans were generated and compared to corresponding, forward-calculated, CT-based plans on the basis of target coverage, isodose distributions, and dose-volume histograms (DVHs). Phantom studies were performed to assess the magnitude and spatial dependence of MRI geometrical distortion. MRIW-based dose calculations overestimated target coverage by 16.1%. Segmentation of bone reduced differences to within 2% of the coverage area on the CT-based plan. Further segmentation of air improved conformity near air-tissue interfaces. Dental artifacts caused substantial target coverage overestimation even on MRIW+B+A. Geometrical distortion was less than 1 mm in an imaging volume 20 × 20 × 20 cm3 around scanner isocenter, but up to 4 mm at 17 cm lateral to isocenter. Bulk density assignment in the framework of MRI-only IMRT head and neck treatment planning is a feasible method with certain limitations. Bone and teeth account for the majority of density heterogeneity effects. While soft tissue is well visualized on MRI compared to CT, dental implants may not be visible on MRI and must be identified by other means and assigned

  4. Flute-Model Acoustic Metamaterials with Simultaneously Negative Bulk Modulus and Mass Density

    CERN Document Server

    Zeng, H C; Chen, H J; Zhai, S L; Zhao, X P

    2012-01-01

    We experimentally constructed a three-dimensional flute-model "molecular" structure acoustic metamaterial(AM)from a periodic array of perforated hollow steel tubes (PHSTs) and investigated its transmission and reflection behaviors in impedance tube system. The AM exhibited a transmission peak and an inverse phase, thus exhibiting the local resonance of the PHSTs. Based on the homogeneous media theory, the effective bulk modulus and mass density of the AM were calculated to be simultaneously negative; the refractive index was also negative. PHST AM slab focusing experiments showed that the medium with a resonant structure exhibited a distinct metamaterial property.

  5. Forest floor bulk density and depth at Savannah River - Draft Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Maier, Brian; Ottmar, Roger; Wright, Clint

    2004-12-28

    Knowing the amount of biomass across a landscape is becoming increasingly important to fire managers as new fuel and fire management decision support systems come on line. Fire managers rarely have the time or funding available to sample fuels operationally and often depend upon mean values for critical variables whose variation is often associated with simple stand characteristics such as age, forest type, time since last burn, stocking, or site, and other easily measured variables. This report outlines a study to collect and analyze litter and duff bulk density samples for developing a simple predictive tool to estimate forest floor fuel loading based on simple stand characteristics.

  6. Impact of twin boundaries on bulk elastic constants: Density-functional theory data for Young׳s modulus of Ag

    Directory of Open Access Journals (Sweden)

    Tobias Klöffel

    2015-06-01

    Here, we present data of density-functional theory calculations of elastic constants and Young׳s modulus for defect-free bulk Ag as well as for bulk Ag containing dense arrays of twin boundaries. It is shown that rigorous convergence tests are required in order to be able to deduce changes in the elastic properties due to bulk defects in a reliable way.

  7. Direct determination of defect density of states in organic bulk heterojunction solar cells

    Science.gov (United States)

    Verma, Upkar K.; Tripathi, Durgesh C.; Mohapatra, Y. N.

    2016-09-01

    The measurement of the occupied trap density of states (DOS) is important for optimization of organic bulk heterojunction solar cells. We demonstrate a direct method for obtaining it from the trap related peak in capacitance-voltage characteristics under different levels of illumination, and its correlation with the dark current density-voltage characteristics. We use the method to measure the parameters of DOS, occupied trap distribution, and its temperature dependence for poly(3-hexathiophene) (P3HT):phenyl-C61-butyric acid methyl ester (PCBM) based solar cells. The total occupied trap concentration is approximately 7 × 1015 cm-3 with a standard deviation for a truncated Gaussian distribution varying between 32 and 44 meV in the temperature range of 310-270 K within a total Gaussian DOS with a standard deviation of 92 meV.

  8. Determination of mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal.

    Science.gov (United States)

    Soluch, Waldemar; Brzozowski, Ernest; Lysakowska, Magdalena; Sadura, Jolanta

    2011-11-01

    Mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal were determined. Mass density was obtained from the measured ratio of mass to volume of a cuboid. The dielectric constants were determined from the measured capacitances of an interdigital transducer (IDT) deposited on a Z-cut plate and from a parallel plate capacitor fabricated from this plate. The elastic and piezoelectric constants were determined by comparing the measured and calculated SAW velocities and electromechanical coupling coefficients on the Z- and X-cut plates. The following new constants were obtained: mass density p = 5986 kg/m(3); relative dielectric constants (at constant strain S) ε(S)(11)/ε(0) = 8.6 and ε(S)(11)/ε(0) = 10.5, where ε(0) is a dielectric constant of free space; elastic constants (at constant electric field E) C(E)(11) = 349.7, C(E)(12) = 128.1, C(E)(13) = 129.4, C(E)(33) = 430.3, and C(E)(44) = 96.5 GPa; and piezoelectric constants e(33) = 0.84, e(31) = -0.47, and e(15) = -0.41 C/m(2).

  9. Integrated analysis software for bulk power system stability

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Nagao, T.; Takahashi, K. [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1994-12-31

    This paper presents Central Research Inst.of Electric Power Industry - CRIEPI`s - own developed three softwares for bulk power network analysis and the user support system which arranges tremendous data necessary for these softwares with easy and high reliability. (author) 3 refs., 7 figs., 2 tabs.

  10. EBSD analysis of MgB2 bulk superconductors

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Inoue, K.; Muralidhar, M.; Berger, K.; Noudem, J.

    2016-04-01

    The grain orientation, the texture and the grain boundary misorientations are important parameters for the understanding of the magnetic properties of the bulk MgB2 samples intended for super-magnet applications. Such data can be provided by electron backscatter diffraction (EBSD) analysis. However, as the grain size (GS) of the MgB2 bulks is preferably in the 100-200 nm range, the common EBSD technique working in reflection operates properly only on highly dense samples. In order to achieve a reasonably good Kikuchi pattern quality on all samples, we apply here the newly developed transmission EBSD (t-EBSD) technique to several bulk MgB2 samples. This method requires the preparation of TEM slices by means of focused ion-beam milling, which are then analyzed within the SEM, operating with a specific sample holder. We present several EBSD mappings of samples prepared with different techniques and at various reaction temperatures.

  11. Epiphyte Density and Diversity on Halimeda incrassata and the Affect on Bulk Isotopic Measurements

    Science.gov (United States)

    Drayer, C. L.; Katz, D. A.; Devlin, Q. B.; Swart, P. K.; Evans, S. L.

    2008-12-01

    Epiphytic density and diversity, organic and inorganic δ13C and organic δ15N were determined for the green calcifying benthic macroalgae, Halimeda incrassata, from Biscayne Bay, a subtropical coastal lagoon located off the southeastern coast of Florida. Cocconeis and Bacteriastrum were determined to be the two most dominant diatomaceous epiphytes living on the Halimeda tissue but an unidentified bacteria proved to be the overall most abundant epiphyte. Cocconeis and the bacteria reached maximum densities mid-strand while Bacteriastrum reached a bimodal peak density at the top and bottom of the strand. Organic δ13C are consistently lighter towards the top of the strand while inorganic δ13C shows the opposite pattern. These results indicate that photosynthetic rates are higher at the top of the strand where metabolic processes are able to preferentially uptake 12C . δ13C values can vary as much as 3 ‰ by algal segment and inorganic values tend to approach equilibrium with the surrounding seawater in the lower algal segments, which are the oldest parts of the thallus. Organic δ15N shows no definite independent trend but increases in δ15N appear to correlate with increased density of the Cocconeis diatom. Organic δ15N can vary as much 9 ‰ by algal segment. This work questions the validity of using bulk isotopic measurements of the algae as a proxy for the origin of nitrogen. Future work should address quantification of epiphytic and Halimeda sp. biomass, the possible presence of other bacteria within the algal tissue and skeletal structure, the relationship between the bacteria and algal host (symbiotic vs. parasitic), and determine how epiphytic communities vary over time (seasons) and space (location within the Bay).

  12. [Spatial variation characteristics of surface soil water content, bulk density and saturated hydraulic conductivity on Karst slopes].

    Science.gov (United States)

    Zhang, Chuan; Chen, Hong-Song; Zhang, Wei; Nie, Yun-Peng; Ye, Ying-Ying; Wang, Ke-Lin

    2014-06-01

    Surface soil water-physical properties play a decisive role in the dynamics of deep soil water. Knowledge of their spatial variation is helpful in understanding the processes of rainfall infiltration and runoff generation, which will contribute to the reasonable utilization of soil water resources in mountainous areas. Based on a grid sampling scheme (10 m x 10 m) and geostatistical methods, this paper aimed to study the spatial variability of surface (0-10 cm) soil water content, soil bulk density and saturated hydraulic conductivity on a typical shrub slope (90 m x 120 m, projected length) in Karst area of northwest Guangxi, southwest China. The results showed that the surface soil water content, bulk density and saturated hydraulic conductivity had different spatial dependence and spatial structure. Sample variogram of the soil water content was fitted well by Gaussian models with the nugget effect, while soil bulk density and saturated hydraulic conductivity were fitted well by exponential models with the nugget effect. Variability of soil water content showed strong spatial dependence, while the soil bulk density and saturated hydraulic conductivity showed moderate spatial dependence. The spatial ranges of the soil water content and saturated hydraulic conductivity were small, while that of the soil bulk density was much bigger. In general, the soil water content increased with the increase of altitude while it was opposite for the soil bulk densi- ty. However, the soil saturated hydraulic conductivity had a random distribution of large amounts of small patches, showing high spatial heterogeneity. Soil water content negatively (P conductivity, while there was no significant correlation between the soil bulk density and saturated hydraulic conductivity.

  13. Influence of critical current density on magnetic force of HTSC bulk above PMR with 3D-modeling numerical solutions

    Science.gov (United States)

    Lu, Yiyun; Qin, Yujie

    2015-09-01

    Numerical simulations of thermo-electromagnetic properties of a high temperature superconducting (HTS) bulk levitating over a permanent magnetic guideway (PMG) are performed by resorting to the quasistatic approximation of the H-method coupling with the classical description of the heat conduction equation. The numerical resolving codes are practiced with the help of the finite element program generation system (FEPG) platform using finite element method (FEM). The E-J power law is used to describe the electric current nonlinear characteristics of HTS bulk. The simulation results show that the heat conduction and the critical current density are tightly relative to the thermal effects of the HTS bulk over the PMG. The heat intensity which responds to the heat loss of the HTS bulk is mainly distributed at the two bottom-corners of the bulk sample.

  14. Comparative Study on Super Fine Mesophase Powder and MCMB Used to Manufacture High-Density Isotropic Carbon Bulks

    Institute of Scientific and Technical Information of China (English)

    LI Tong-qi; HU Zi-jun; WANG Jun-shan; GUO Yu-ming; WANG Cheng-yang

    2006-01-01

    Mesocarbon microbeads (MCMB) and super fine mesophase powder (SFMP) were prepared firstly from a coal tar pitch and then hot-condensed into high-density isotropic carbon (HDIC) bulks under 160 Mpa and finally sintered at 1 000 ℃. By analyzing the thermogravimetric behavior of the MCMB and SFMP powders, their volume shrinkage and weight loss during sintering and the bulk density and flexural strengths of their sintered bulks, it was found that the smaller sizes and the richer β-resin contents of SFMP have facilitated formation of sintered bulks with more compact isotropic structure and higher flexural strengths than MCMB. Because of the filling and bonding effects of SFMP on MCMB bulks, addition of SFMP, albeit a little, can greatly increase the flexural strengths of sintered bulks of MCMB. However, adding MCMB, even a slight amount, into SFMP can severely impair the flexural strength of sintered bulks. This might be attributed to both the crack initiation along the boundaries between MCMB and SFMP and the formation of layered texture of MCMB sphere.

  15. The Relations Between Soil Water Retention Characteristics, Particle Size Distributions, Bulk Densities and Calcium Carbonate Contents for Danish Soils

    DEFF Research Database (Denmark)

    Jensen, Niels H.; Balstrøm, Thomas; Breuning-Madsen, Henrik

    2005-01-01

    functions developed in HYPRES (Hydraulic Properties of European Soils). Introducing bulk density as a predictor improved the equation for pressure head –1 kPa but not for lower ones. The grouping of data sets in surface and subsurface horizons or in textural classes did not improve the equations. Based......A database containing about 800 soil profiles located in a 7-km grid covering Denmark has been used to develop a set of regression equations of soil water content at pressure heads –1, -10, -100 and –1500 kPa versus particle size distribution, organic matter, CaCO3 and bulk density. One purpose...... was to elaborate equations based of soil parameters available in the Danish Soil Classification's texture database on particle size distribution and organic matter. It was also tested if inclusion of bulk density or CaCO3 content (in CaCO3-containing samples) as predictors or grouping in surface and subsurface...

  16. Gas Transport Parameters for Landfill Final Cover Soil: Measurements and Model Modification by Dry Bulk Density

    Science.gov (United States)

    Wickramarachchi, P. N.; Kawamoto, K.; Hamamoto, S.; Nagamori, M.; Moldrup, P.; Komatsu, T.

    2011-12-01

    Landfill sites have been emerging in greenhouse warming scenarios as a significant source of atmospheric methane (CH4). Until recently, landfill management strategies have mainly addressed the problem of preventing groundwater contamination and reduction of leachate generation. Being one of the largest sources of anthropogenic CH4 emission, the final cover system should also be designed for minimizing the greenhouse gases migration into the atmosphere or the areas surrounding the landfill while securing the hydraulic performance. Compared to the intensive research efforts on hydraulic performances of landfill final cover soil, few studies about gas transport characteristics of landfill cover soils have been done. However, recent soil-gas studies implied that the effects of soil physical properties such as bulk density (i.e., compaction level), soil particle size are key parameters to understand landfill gaseous performance. The gas exchange through the final cover soils is controlled by advective and diffusive gas transport. Air permeability (ka) governs the advective gas transport while the soil-gas diffusion coefficient (Dp) governs diffusive gas transport. In this study, the effects of compaction level and particle size fraction effects on ka and Dp for landfill final cover soil was investigated. The disturbed soil samples were taken from landfill final cover in Japan. A compaction tests were performed for the soil samples with two different size fractions (content , the soil samples were repacked into soil cores (i.d. 15-cm, length 12-cm, 2120 cm3) at two different compaction levels [(MP):2700 kN/m2 and (SP):600 kN/m2]. After the compaction tests, ka and Dp were measured and then samples were saturated and subsequently drained at different soil-water matric potential of 0.98, 2.94, 9.81, 1235 kPa and with air-dried and oven-dried conditions. Results showed that measured Dp and ka values for the coarser (content. Further, compaction effort was much significant

  17. Superconductors, analysis and applications, with special reference to the utilisation of bulk (Re)BCO materials

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, T.A., E-mail: tac1000@cam.ac.u [University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2010-11-01

    The Electrical Power and Energy Conversion (EPEC) superconductivity group at Cambridge University has been working on the application of superconductivity to large scale devices. This work is taking place over a range of areas which cover FCLs, motors and generators, SMES, accelerator magnets and MRI. The research is underpinned by advanced modelling techniques using both pure Critical State models and E-J models to analyse the behaviour of the superconductors. As part of the device design we are concentrating on the analysis of AC losses in complicated geometries such as are found in motor windings and the magnetisation of bulk superconductors to enable their full potential to be realised. We are interested in the full range of high-temperature superconductors and have measured and predicted the performance of YBCO, MgB{sub 2} and BSCCO at a range of temperatures and in wire, tape and bulk forms. This paper concentrates on recent work which includes: modelling of coils using formulations based on H and A. A critical state model for the analysis of coils in SMES; crossed field effects in bulk superconductors; a magnetic model together with experimental results which explain and describe the method of flux pumping whereby a bulk superconductor can be magnetised to a high flux density using a repeatedly applied field of low flux density and finally a new configuration for MRI magnets

  18. Bulk segregant analysis using single nucleotide polymorphism microarrays.

    Directory of Open Access Journals (Sweden)

    Anthony Becker

    Full Text Available Bulk segregant analysis (BSA using microarrays, and extreme array mapping (XAM have recently been used to rapidly identify genomic regions associated with phenotypes in multiple species. These experiments, however, require the identification of single feature polymorphisms (SFP between the cross parents for each new combination of genotypes, which raises the cost of experiments. The availability of the genomic polymorphism data in Arabidopsis thaliana, coupled with the efficient designs of Single Nucleotide Polymorphism (SNP genotyping arrays removes the requirement for SFP detection and lowers the per array cost, thereby lowering the overall cost per experiment. To demonstrate that these approaches would be functional on SNP arrays and determine confidence intervals, we analyzed hybridizations of natural accessions to the Arabidopsis ATSNPTILE array and simulated BSA or XAM given a variety of gene models, populations, and bulk selection parameters. Our results show a striking degree of correlation between the genotyping output of both methods, which suggests that the benefit of SFP genotyping in context of BSA can be had with the cheaper, more efficient SNP arrays. As a final proof of concept, we hybridized the DNA from bulks of an F2 mapping population of a Sulfur and Selenium ionomics mutant to both the Arabidopsis ATTILE1R and ATSNPTILE arrays, which produced almost identical results. We have produced R scripts that prompt the user for the required parameters and perform the BSA analysis using the ATSNPTILE1 array and have provided them as supplemental data files.

  19. Gross-fragmentation of meteoroids and bulk density of Geminids from photographic fireball records

    Science.gov (United States)

    Ceplecha, Zdenek; Mccrosky, R. E.

    1992-01-01

    meteoroid by allowing for one or more points, where sudden gross fragmentation can occur. Using this generalized solution, the distances along the meteoroid trajectory can be computed for any choice of input parameters and compared with the observed distances flown by the meteoroid. For the most precise and long fireball trajectories, the least-squares solution can, thus, yield the initial velocities, the ablation coefficients, the dynamical masses, the positions of gross-fragmentation points, and the terminal mass. At a gross-fragmentation point, the ratio of the main mass to all the remaining fragments can be compared with the dynamic mass determined from our gross-fragmentation model and, thus, the meteoroid bulk density can be evaluated. We applied the gross-fragmentation model to sever PN fireballs showing time changes of residuals, and we recognized that, in all these cases, the new computed bulk densities of meteoroids resulted higher in comparison with the meteoroid densities determined with the non-gross-fragmentation model. Other aspects of the study are discussed.

  20. Investigating the dynamics of bulk snow density in dry and wet conditions using a one-dimensional model

    NARCIS (Netherlands)

    De Michele, C.; Avanzi, F.; Ghezzi, A.; Jommi, C.

    2013-01-01

    The snowpack is a complicated multiphase mixture with mechanical, hydraulic, and thermal properties highly variable during the year in response to climatic forcings. Bulk density is a macroscopic property of the snowpack used, together with snow depth, to quantify the water stored. In seasonal snowp

  1. Free-space reflection method for measuring moisture content and bulk density of particulate materials at microwave frequency

    Science.gov (United States)

    Li, Chenxiao; Han, Bing; Zhang, Tao

    2015-03-01

    A measurement system based on free-space reflection method is designed for simultaneous and independent determination of moisture content and bulk density of particulate materials. The proposed system consists of microwave cavity oscillator, horn antenna, slide rail, sample holder, mixer, and digital meter. Sand and rice with different moisture contents and bulk densities are chosen as samples. Calibration models for moisture content and bulk density are proposed according to the measurement of the position of the minimum of the traveling-standing wave and the ratio of the maximum-to-minimum field strength of the traveling-standing wave at different temperatures. The moisture constant, ranging from 0% to 24.6%, is obtained with a coefficient of determination (R2) greater than 0.982 and a standard error of prediction (SEP) value of less than 0.695%. The bulk density, ranging from 0.501 g/cm3 to 1.822 g/cm3, is determined with a R2 ≥ 0.961 and a SEP value ranging from 0.0144 g/cm3 to 0.0382 g/cm3 for different samples.

  2. Affine density in wavelet analysis

    CERN Document Server

    Kutyniok, Gitta

    2007-01-01

    In wavelet analysis, irregular wavelet frames have recently come to the forefront of current research due to questions concerning the robustness and stability of wavelet algorithms. A major difficulty in the study of these systems is the highly sensitive interplay between geometric properties of a sequence of time-scale indices and frame properties of the associated wavelet systems. This volume provides the first thorough and comprehensive treatment of irregular wavelet frames by introducing and employing a new notion of affine density as a highly effective tool for examining the geometry of sequences of time-scale indices. Many of the results are new and published for the first time. Topics include: qualitative and quantitative density conditions for existence of irregular wavelet frames, non-existence of irregular co-affine frames, the Nyquist phenomenon for wavelet systems, and approximation properties of irregular wavelet frames.

  3. Effects of Nb and Si on densities of valence electrons in bulk and defects of Fe3Al alloys

    Institute of Scientific and Technical Information of China (English)

    邓文; 钟夏平; 黄宇阳; 熊良钺; 王淑荷; 郭建亭; 龙期威

    1999-01-01

    Positron lifetime measurements have been performed in binary Fe3Al and Fe3Al doping with Nb or Si alloys. The densities of valence electrons of the bulk and microdefects in all tested samples have been calculated by using the positron lifetime parameters. Density of valence electron is low in the bulk of Fe3Al alloy. It indicates that, the 3d electrons in a Fe atom have strong-localized properties and tend to form covalent bonds with Al atoms, and the bonding nature in Fe3Al is a mixture of metallic and covalent bonds. The density of valence electron is very low in the defects of Fe3Al grain boundary, which makes the bonding cohesion in grain boundary quite weak. The addition of Si to Fe3Al gives rise to the decrease of the densities of valence electrons in the bulk and the grain boundary thus the metallic bonding cohesion. This makes the alloy more brittle. The addition of Nb to Fe3Al results in the decrease of the ordering energy of the alloy and increases the density of valence electron and th

  4. Fabrication of bulk nanostructured permanent magnets with high energy density: challenges and approaches.

    Science.gov (United States)

    Yue, Ming; Zhang, Xiangyi; Liu, J Ping

    2017-03-06

    Nanostructured permanent magnetic materials, including exchange-coupled nanocomposite permanent magnets, are considered as the next generation of high-strength magnets for future applications in energy-saving and renewable energy technologies. However, fabrication of bulk nanostructured magnets remains very challenging because conventional compaction and sintering techniques cannot be used for nanostructured bulk material processing. In this paper we review recent efforts at producing bulk nanostructured single-phase and composite magnetic materials with emphasis on grain size control, anisotropy generation and interface modification.

  5. Optimization of sintering conditions in bulk MgB{sub 2} material for improvement of critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, M., E-mail: miryala1@shibaura-it.ac.jp [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Nozaki, K.; Kobayashi, H. [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Zeng, X.L.; Koblischka-Veneva, A.; Koblischka, M.R. [Experimental Physics, Saarland University, P.O. Box 151150, 66041 Saarbrücken (Germany); Inoue, K.; Murakami, M. [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan)

    2015-11-15

    The present investigation focuses on methods to further improve the J{sub c} values of disk-shaped bulk MgB{sub 2} superconductors by optimizing the sintering conditions. We prepared two sets of bulk MgB{sub 2} material from commercial high-purity powders of Mg metal and amorphous B using a single-step solid-state reaction process. To optimize the sintering time, a set of samples was sintered at 775 °C with sintering duration ranging between 1 and 10 h (pure Ar atmosphere). A second set of samples was produced similarly at 775, 780, 785, 795, 800 and 805 °C (3 h, pure argon atmosphere). X-ray diffraction analysis showed that both sets of samples were single phase MgB{sub 2}. Magnetization measurements confirmed a sharp superconducting transition with T{sub c,onset} ≈ 38.2 K–38.8 K. The critical current density (J{sub c}) values for MgB{sub 2} samples produced for 1 h were the highest in all processed materials, i.e., the high J{sub c} value of 270,000 A/cm{sup 2} and 125,000 A/cm{sup 2} (20 K, self-field and 1 T) were achieved in the sample produced at 775 °C, without any additional doping. In contrast, the second series of samples clearly indicated that at 805 °C (3 h) the highest J{sub c} of 245,000 A/cm{sup 2} and 110,000 A/cm{sup 2} (20 K, self-field and 1 T) were achieved. AFM and EBSD observations indicated that largest amount of fine grains do exist in the sample sintered at 775 °C, but the narrowest distribution of grains does exist in the sample sintered at 800 °C. The present results clearly demonstrate a strong relation between the microstructure and the pinning performance. The optimization of the sintering conditions is crucial to improve the performance of bulk MgB{sub 2} samples. - Highlights: • We had successfully improved the performance of sintered, pure bulk MgB{sub 2} materials. • EBSD observations clarified that the grain sizes are in the 100–500 nm range. • The high J{sub c} value at 20 K, 0 T and 1 T are 2.70 × 10{sup 5} A

  6. Impact of twin boundaries on bulk elastic constants: Density-functional theory data for Young׳s modulus of Ag.

    Science.gov (United States)

    Klöffel, Tobias; Bitzek, Erik; Meyer, Bernd

    2015-06-01

    Experimental and theoretical studies on nanowires have reported a size-dependence of the Young׳s modulus in the axial direction, which has been attributed to the increasing influence of surface stresses with decreasing wire diameter. Internal interfaces and their associated interface stresses could lead to similar changes in the elastic properties. In Kobler et al. [1], however, we reported results from atomistic calculations which showed for Ag that twin boundaries have a negligible effect on the Young׳s modulus. Here, we present data of density-functional theory calculations of elastic constants and Young׳s modulus for defect-free bulk Ag as well as for bulk Ag containing dense arrays of twin boundaries. It is shown that rigorous convergence tests are required in order to be able to deduce changes in the elastic properties due to bulk defects in a reliable way.

  7. First principles study on the charge density and the bulk modulus of the transition metals and their carbides and nitrides

    Institute of Scientific and Technical Information of China (English)

    Li Cheng-Bin; Li Ming-Kai; Yin Dong; Liu Fu-Qing; Fan Xiang-Jun

    2005-01-01

    A first principles study of the electronic properties and bulk modulus (B0) of the fcc and bcc transition metals,transition metal carbides and nitrides is presented. The calculations were performed by plane-wave pseudopotential method in the framework of the density functional theory with local density approximation. The density of states and the valence charge densities of these solids are plotted. The results show that B0 does not vary monotonically when the number of the valence d electrons increases. B0 reaches a maximum and then decreases for each of the four sorts of solids. It is related to the occupation of the bonding and anti-bonding states in the solid. The value of the valence charge density at the midpoint between the two nearest metal atoms tends to be proportional to B0.

  8. New determination of the size and bulk density of the binary asteroid 22 Kalliope from observations of mutual eclipses

    CERN Document Server

    Descamps, P; Pollock, J; Berthier, J; Vachier, F; Birlan, M; Kaasalainen, M; Harris, A W; Wong, M; Romanishin, W; Cooper, E M; Kettner, K A; Wiggins, P; Kryszczynska, A; Polinska, M; Colliac, J -F; Devyatkin, A; Verestchagina, I; Gorshanov, D

    2007-01-01

    In 2007, the M-type asteroid 22 Kalliope reached one of its annual equinoxes. As a consequence, its small satellite Linus orbiting in the equatorial plane underwent a season of mutual eclipses. A dedicated international campaign of observations was organized in order to study several of these scarce events. In this paper we present a summary of the observations and a comprehensive analysis based on a global model of a binary system in mutual eclipse. One of the most significant results is the derivation of a size for Kalliope of 156 +/- 4km, 11% smaller than its IRAS size. As to the diameter of Linus, it is estimated to 28+/-2 km. This shortening of Kalliope is confirmed by the interpretation of earlier observations, such as adaptive optics imaging and those of the stellar occultation of 2006 November, 7. Kalliope appears now as a much more common object with a bulk density of 4.1+/-0.3g/cm3 and a macroscopic porosity of ~20-30% typical of that measured for well-known binary main belt systems. Furthermore, we...

  9. Difference between bulk and thin film densities of metal oxide and fluoride films studied by NRA depth profiling techniques

    CERN Document Server

    Coban, A; Durrani, S A

    2002-01-01

    Nuclear reaction analysis techniques have been used to study the difference between bulk and thin film densities of different dielectric (WO sub 3 , MgF sub 2 , NdF sub 3 , LaF sub 3 and ThF sub 4) thin films. Thicknesses of the films were measured by optical methods. The sup 1 sup 8 O(p,alpha) sup 1 sup 5 N reaction was used at 730 keV to profile WO sub 3 prepared with different thicknesses on a tantalum backing by thermal evaporation of natural WO sub 3. We have also successfully tested the sup 1 sup 8 O(p,alpha) sup 1 sup 5 N reaction at the 629 keV (GAMMA=2.1 keV) resonance for the same purpose. Excitation function measurement of the reaction was performed around the resonant energy at a detection angle of 150 deg. . In order to obtain the oxygen profiles of the thin films non-resonant part of the excitation function was deconvoluted using the known cross-section data of the reaction. Also, we studied different films of MgF sub 2 , NdF sub 3 , LaF sub 3 and ThF sub 4 using the 483.85 keV resonance in the ...

  10. Laboratory scale investigation to improve the productivity of stamp charge coke oven through optimisation of bulk density of coal cake

    Energy Technology Data Exchange (ETDEWEB)

    Dash, P.S.; Krishnan, S.H.; Sharma, R.; Banerjee, P.K.; Haldar, S.K. [Tata Steel, Jamshedpur (India)

    2005-07-01

    In the recent past, it was realised that the gross coke yield was going down as a result of lower oven throughput in the stamp charged batteries of Tata Steel. The basic reason for this being the net reduction in the ash content of the coal blend used due to the incorporation of higher percentage of low ash imported coals and reduction in the ash content of captive coals through washing. The coals having higher ash content improves the bulk density, as the specific gravity of ash is higher than that of pure coal. Moreover, the ash components have affinity for water and pure coal repels water, which in case of pure coal, works against the holding together of the blend. Hence, lower the ash content, less is the bulk density of cake under identical stamping energy and lower the bulk density, less is the oven throughput. In order to maximise the oven throughput and productivity, a study was conducted in the laboratory mainly to assess the effect of various blend constituents and their ash content on the bulk density of coal charge. The effect of ash content on the coal cake stability has also been dealt with. This study, in short, is a useful tool for selecting the right type of coals and designing the optimum blend for stamp charging to achieve maximum throughput and productivity. In addition, studies were also carried out to assess the effect of addition of various binders on coal cake stability at lower moisture level which would also help in achieving higher throughput and productivity.

  11. Standard Test Method for Water Absorption, Bulk Density, Apparent Porosity, and Apparent Specific Gravity of Fired Whiteware Products

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method covers procedures for determining water absorption, bulk density, apparent porosity, and apparent specific gravity of fired unglazed whiteware products. 1.2 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Estimation of critical current density and grain connectivity in superconducting MgB 2 bulk using Campbell’s method

    Science.gov (United States)

    Ni, B.; Morita, Y.; Liu, Z.; Liu, C.; Himeki, K.; Otabe, E. S.; Kiuchi, M.; Matsushita, T.

    2008-09-01

    Many recent reports on the critical current density ( Jc) in superconducting MgB 2 bulks indicated that improving the grain connectivity is important, since the obtained Jc values were generally much lower than those in other metallic superconductors and it was ascribed to the poor connectivity between grains in polycrystalline MgB 2. In this study, we focused on the estimation of the global critical current density, super-current path, grain connectivity and their relationships with the faults volume fraction in the MgB 2 bulks prepared by a modified PIT (powder in tube) method. Campbell’s method was applied for the purpose of obtaining the penetrating AC flux profile and the characteristic of AC magnetic field vs. penetration depth from the sample’s surface. A computer simulation on the penetrating AC flux profile in MgB 2 bulks with randomly distributed voids, oxidized grains and other faults was also carried out. Jc obtained by Campbell’s method turned out to be smaller than that obtained from the SQUID measurement, implying that the global super-current was reduced by the existence of various faults and the lack of the electrical connectivity. It was verified that the relationship between the global critical current characteristics and the faults contained in MgB 2 samples can be quantitatively clarified by comparing the simulated critical current densities and other factors with the experimental results.

  13. Critical current densities and irreversibility fields of MgB 2 bulks

    Science.gov (United States)

    Kumakura, H.; Takano, Y.; Fujii, H.; Togano, K.; Kito, H.; Ihara, H.

    2001-11-01

    We prepared two MgB 2 bulks by applying conventional sintering and high-pressure sintering methods, and compared the current carrying properties. Jc obtained by the resistive method was larger than that obtained by the magnetic method. Jc- B curves obtained by the resistive method showed no history effect. These results indicate that most of the superconducting currents flowing in the MgB 2 bulks were intergrain (transport) currents and intragrain currents were negligibly small. The high-pressure sintered sample with smaller grain size showed smaller field dependence of Jc and higher Birr than the conventionally sintered sample with larger grain size. This behavior can be explained by the grain boundary flux pinning.

  14. Impact of Molecular Orientation and Packing Density on Electronic Polarization in the Bulk and at Surfaces of Organic Semiconductors.

    Science.gov (United States)

    Ryno, Sean M; Risko, Chad; Brédas, Jean-Luc

    2016-06-08

    The polarizable environment surrounding charge carriers in organic semiconductors impacts the efficiency of the charge transport process. Here, we consider two representative organic semiconductors, tetracene and rubrene, and evaluate their polarization energies in the bulk and at the organic-vacuum interface using a polarizable force field that accounts for induced-dipole and quadrupole interactions. Though both oligoacenes pack in a herringbone motif, the tetraphenyl substituents on the tetracene backbone of rubrene alter greatly the nature of the packing. The resulting change in relative orientations of neighboring molecules is found to reduce the bulk polarization energy of holes in rubrene by some 0.3 eV when compared to tetracene. The consideration of model organic-vacuum interfaces highlights the significant variation in the electrostatic environment for a charge carrier at a surface although the net change in polarization energy is small; interestingly, the environment of a charge even just one layer removed from the surface can be viewed already as representative of the bulk. Overall, it is found that in these herringbone-type layered crystals the polarization energy has a much stronger dependence on the intralayer packing density than interlayer packing density.

  15. Impact of Molecular Orientation and Packing Density on Electronic Polarization in the Bulk and at Surfaces of Organic Semiconductors

    KAUST Repository

    Ryno, Sean M.

    2016-05-16

    The polarizable environment surrounding charge carriers in organic semiconductors impacts the efficiency of the charge transport process. Here, we consider two representative organic semiconductors, tetracene and rubrene, and evaluate their polarization energies in the bulk and at the organic-vacuum interface using a polarizable force field that accounts for induced-dipole and quadrupole interactions. Though both oligoacenes pack in a herringbone motif, the tetraphenyl substituents on the tetracene backbone of rubrene alter greatly the nature of the packing. The resulting change in relative orientations of neighboring molecules is found to reduce the bulk polarization energy of holes in rubrene by some 0.3 eV when compared to tetracene. The consideration of model organic-vacuum interfaces highlights the significant variation in the electrostatic environment for a charge carrier at a surface although the net change in polarization energy is small; interestingly, the environment of a charge even just one layer removed from the surface can be viewed already as representative of the bulk. Overall, it is found that in these herringbone-type layered crystals the polarization energy has a much stronger dependence on the intralayer packing density than interlayer packing density.

  16. Micro and bulk analysis of prostate tissues classified as hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatek, W.M. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Cracow (Poland)], E-mail: wojciech.kwiatek@ifj.edu.pl; Banas, A.; Banas, K. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Cracow (Poland); Cinque, G. [INFN- Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy); Dyduch, G. [Collegium Medicum, Jagiellonian University, Cracow (Poland); Falkenberg, G. [Hasylab, DESY Notkestraae 85, D-22603 Hamburg (Germany); Kisiel, A. [Institute of Physics, Jagiellonian University, ul.Reymonta 4, 30-059 Cracow (Poland); Marcelli, A. [INFN- Laboratori Nazionali di Frascati, Via E. Fermi 40, I-00044 Frascati (Italy); Podgorczyk, M. [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342 Cracow (Poland)

    2007-07-15

    BPH (Benign Prostatic Hyperplasia) is the most common benign neoplasm (non cancerous enlargement of the prostate gland), whose prevalence increases with age. The gland, when increased in size, exerts pressure on the urethra, causing obstruction to urine flow. The latter may result in severe urinary tract and kidney conditions. In this work prostate samples from patients diagnosed with BPH were analyzed using synchrotron radiation. Micro-analysis of the hyperplastic samples was carried out on the L-beam line at HASYLAB, DESY (Germany), while bulk analysis on selected samples was performed at the DRX2 beamline at LNF, Frascati (Italy). Microanalysis with a mono-energetic beam 15 {mu}m in diameter confirmed that concentrations of certain elements, such as S, Mn, Cu, Fe and Zn, are good indicators of pathological disorders in prostate tissue that may be considered effective tracers of developing compliant. The concentrations of Mn, Cu, Fe and Zn are higher in hyperplastic tissues, as compared to normal ones, while for sulphur the opposite is observed. Additionally, Fe and S K-edge XANES (X-ray Absorption Near Edge Structure) spectroscopy experiments were carried out in order to determine the chemical speciation of these elements in our samples.

  17. Micro and bulk analysis of prostate tissues classified as hyperplasia

    Science.gov (United States)

    Kwiatek, W. M.; Banaś, A.; Banaś, K.; Cinque, G.; Dyduch, G.; Falkenberg, G.; Kisiel, A.; Marcelli, A.; Podgórczyk, M.

    2007-07-01

    BPH (Benign Prostatic Hyperplasia) is the most common benign neoplasm (non cancerous enlargement of the prostate gland), whose prevalence increases with age. The gland, when increased in size, exerts pressure on the urethra, causing obstruction to urine flow. The latter may result in severe urinary tract and kidney conditions. In this work prostate samples from patients diagnosed with BPH were analyzed using synchrotron radiation. Micro-analysis of the hyperplastic samples was carried out on the L-beam line at HASYLAB, DESY (Germany), while bulk analysis on selected samples was performed at the DRX2 beamline at LNF, Frascati (Italy). Microanalysis with a mono-energetic beam 15 μm in diameter confirmed that concentrations of certain elements, such as S, Mn, Cu, Fe and Zn, are good indicators of pathological disorders in prostate tissue that may be considered effective tracers of developing compliant. The concentrations of Mn, Cu, Fe and Zn are higher in hyperplastic tissues, as compared to normal ones, while for sulphur the opposite is observed. Additionally, Fe and S K-edge XANES (X-ray Absorption Near Edge Structure) spectroscopy experiments were carried out in order to determine the chemical speciation of these elements in our samples.

  18. The influence of post-growth thermal treatments on the critical current density of TSMG YBCO bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Diko, P; Antal, V; Zmorayova, K; Sefcikova, M; Kovac, J [Institute of Experimental Physics SAS, Watsonova 47, 04001 Kosice (Slovakia); Chaud, X [CNRS/CRETA, 25, Avenue des Martyrs, 38042 Grenoble Cedex 9 (France); Yao, X [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Chen, I [Department of Materials Science and Engineering, National Cheng Kung University (NCKU) Tainan, Taiwan (China); Eisterer, M; Weber, H W [Vienna University of Technology, Atominstitut, Stadionallee 2, 1020 Vienna (Austria)

    2010-12-15

    Oxygenation and thermochemical post-growth treatments of top seeded melt-growth (TSMG) YBCO bulk superconductors can significantly influence critical current density. It is shown that, depending on oxygenation conditions and the size of 211 particles, different reductions of intrinsic critical current density values can be obtained due to the reduction in the sample cross-section caused by the presence of a/b-microcracks induced by 211 particles, and a/b- and a/c-cracks induced by oxygenation. The possibility of eliminating oxygenation cracks by high pressure oxygenation and consequently significantly increasing the macroscopic critical current density is demonstrated. An effective dopant concentration for chemical pinning is proposed and possible clustering of substitutions in the Y123 lattice by thermochemical treatments is shown.

  19. Optimization and Performance Analysis of Bulk-Driven Differential Amplifier

    Directory of Open Access Journals (Sweden)

    Antarpreet kaur

    2014-04-01

    Full Text Available In recent years, there has been an increasing demand for high-speed digital circuits at low power consumption. This paper presents a design of input stage of Operational Amplifier i.e cascode differential amplifier using a standard 65nm CMOS Technology.A comparison betweem gate-driven, bulk-driven and cascode bulk driven bulk-driven differential amplifier is described. The Results demonstrate that CMMR is 83.98 dB, 3-dB Bandwidth is 1.04 MHz. The circuit dissipate power of 28uWunder single supply of 1.0V.

  20. Optimisation of coal blend and bulk density for coke ovens by vibrocompacting technique non-recovery ovens

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.P.; Vinoo, D.S.; Yadav, U.S.; Ghosh, S.; Lal, J.P.N. [J.S.W. Steel Ltd, Bellary (India)

    2007-09-15

    The quality of coke produced in a coke oven depends on the coal blend characteristics and carbonisation conditions. Scarcity of good quality coking coal made it necessary to look for techniques capable of producing superior coke from inferior coals. Precarbonisation techniques improve the bulk density of the coal charge and produce good quality coke from inferior coals. The stamp charging technique, the most effective among them requires finer crushing of coal and higher moisture as binder, both requiring additional energy. JSW Steel has adopted vibrocompaction along with non-recovery ovens for its 1.2 Mtpa coke production. This is a highly ecofriendly coke making process producing excellent quality coke from inferior coals. It increases the bulk density of cake, similar to stamp charging, using compaction in place of stamping. A cake density of 1.10 t m{sup -3} has been achieved using the vibrocompacting technique with optimum moisture and crushing fineness. Coal blend containing up to 35% soft coal and coking coal, having 32% volatile matter have been successfully used to produce a coke with coke strength after reaction >65%, coke reactivity index <25% and M10 <6%. The paper discusses the experience of operating vibrocompaction non-recovery coke ovens.

  1. Universal bulk charge-density-wave (CDW) correlations in the cuprate superconductors

    Science.gov (United States)

    Tabis, Wojciech

    2014-03-01

    The recent observation of bulk CDW order in YBa2Cu3O8+δ(YBCO) in competition with superconductivity is a significant development. Using Cu L-edge resonant X-ray scattering, we also observe bulk CDW order in HgBa2CuO4+δ(Hg1201 Tc = 72K). The correlations appear below TCDW ~ 200K, well below the pseudogap temperature T* ~ 320K associated with unusual magnetism, but coincident with the onset of Fermi-liquid-like charge transport. In contrast to YBCO, we observe no decrease of the CDW amplitude below Tc, and the correlation length is short and temperature independent. CDW correlations therefore are a universal property of underdoped cuprates, enhanced by low structural symmetry and a magnetic field, but fundamentally not in significant competition with superconductivity. We also discuss the relationship between the CDW modulation wave vector and the Fermi surface area extracted from QO experiments. Work supported by DOE-BES. In collaboration with Y. Li, M. Le Tacon, L. Braicovich, A. Kreyssig, M. Minola, G. Dellea, E. Weschke, M. Veit, A. Goldman, T. Schmitt, G. Ghiringhelli, N. Barisic, M.K. Chan, C. Dorow, G. Yu, X. Zhao, B. Keimer, M. Greven.

  2. Assessment of some soil thermal conductivity models via variations in temperature and bulk density at low moisture range

    Science.gov (United States)

    Mahdavi, Seyed Mohamad; Neyshabouri, Mohammad Reza; Fujimaki, Haruyuki

    2016-08-01

    Simulation of heat transfer in soil under steady and unsteady situations requires reliable estimate of soil thermal conductivity (λ) at varying environmental conditions. In the current work several soil thermal conductivity predicting models including I) de Vries, II) Campbell, III) combined de Vries and Campbell and IV) de Vries-Nobre were evaluated for the four soils of coarse sand, sandy loam, loam and clay loam textured at varying in temperature and bulk density at low moisture range. Thermal conductivities measured by the cylindrical probe method served as the reference for models assessment. Results showed that approximately same thermal conductivities obtained by the five methods at low moisture range (θ ≤ 0.05 m3/m3). Also the de Vries and de Vries-Campbell models produced accurate than Campbell and de vries-Nobre models. The accuracy of the two models increased with soil compaction but decreased with temperature rise. Campbell model showed more reliability at higher (311.16 and 321.16 K) temperatures; but its accuracy declined with soil compaction in current work. It seems that assuming needle shape for the soil particles is far away from the reality whereas assuming spherical shapes may be more realistic and produced more satisfactory prediction of thermal conductivity. The compaction would alter particle arrangement and may increase the contact area of particles; and then make them behave more or less spherical shape.it seems thermal conductivity in solid particles increase via increasing in temperature. Since a modified mineral shape factor, g m , was developed as a combination between sphere and needle according to geometric mean particle diameter as well as bulk density and temperature as modifying factors. This factor increased the accuracy of de Vries-Nobre model up to 10.37%. Regarding nonlinear regression model, moisture content, bulk density, temperature and quartz content demonstrated significant effect on soil thermal conductivity in our

  3. Econometric Analysis of Bulk Shipping: implications for investment strategies and financial decision-making

    NARCIS (Netherlands)

    S. Tsolakis

    2005-01-01

    textabstractThis thesis provides an econometric analysis of the bulk shipping markets and the implications for shipping investment and financial decision making. Chapter 1 sets the scene by providing a historic analysis of bulk shipping markets over the last 55 years. From this analysis, four shipp

  4. Bulk Densities of Binary Asteroids from the Warm Spitzer NEO Survey

    NARCIS (Netherlands)

    Kistler, John; Trilling, D. E.; Mueller, M.; Hora, J. L.; Harris, A. W.; Bhattacharya, B.; Bottke, W. F.; Chesley, S.; Emery, J. P.; Fazo, G.; Mainzer, A.; Penprase, B.; Smith, H. A.; Spahr, T. B.; Stansberry, J. A.; Thomas, C. A.

    2010-01-01

    The Warm Spitzer NEO survey, ExploreNEOs, will observe approximately 700 Near Earth Asteroids. Several of these objects are known to be binary asteroid systems. Binary systems are interesting due to the unique opportunity they present for determining the masses and densities of their constituent bod

  5. Effects of density difference of constituent elements on glass formation in TiCu-based bulk metallic glasses

    Institute of Scientific and Technical Information of China (English)

    Zhongyan Zhang; Zengbao Jiao; Jie Zhou; Yuan Wu; Hui Wang; Xiongjun Liu; Zhaoping Lun

    2013-01-01

    Glass formation is generally favored by a large atomic size mismatch among constituent elements, which usually leads to large density differences among them as well. During melting, elemental segregation occurs due to Stokes’ law and then inevitably affects glass formation. In this paper, such effects on glass-forming ability in a TiCu-based alloy system have been demonstrated. In the bulk glass-forming composition Ti43Cu42Hf14Si1, macroscopic segregation of Si was observed in the as-melted ingots and silicon was completely depleted in the as-cast rods. In another Ti33Cu47Ni8Zr11Si1 alloy, nevertheless, the effects of density differences among the constituent elements were less severe. It was also confirmed that using proper pre-alloys could be an effective way in alleviating the side effects of the elemental segregation.

  6. Holographic fluid with bulk viscosity, perturbation of pressure and energy density at finite cutoff surface in the Einstein gravity

    CERN Document Server

    Hu, Ya-Peng; Wu, Xiao-Ning

    2014-01-01

    Using the gravity/fluid correspondence in our paper, we investigate the holographic fluid at finite cutoff surface in the Einstein gravity. After constructing the first order perturbative solution of the Schwarzschild-AdS black brane solution in the Einstein gravity, we focus on the stress-energy tensor of the dual fluid with transport coefficients at the finite cutoff surface. Besides the pressure and energy density of dual fluid are obtained, the shear viscosity is also obtained. The most important results are that we find that if we adopt different conditions to fix the undetermined parameters contained in the stress-energy tensor of the dual fluid, the pressure and energy density of the dual fluid can be perturbed. Particularly, the bulk viscosity of the dual fluid can also be given in this case.

  7. Diffusion of Chloride Ions in Soils: Ⅰ.Influences of Soil Moisture,Bulk Density and Temperature

    Institute of Scientific and Technical Information of China (English)

    XUMINGGANG; ZHANGYIPING; 等

    1997-01-01

    Diffusion coefficients of chlorde ions in four soils of different exture with varying effective moisture content and varying bulk density from 1.1 to 1.6 g cm3 under three different temperatures were determined by the diffusion-cell method using 36Cl-labelled CaCl2 solution.The result showed that activation energy decreased with water content,which indicated that the threshold fro diffusion was lower at a higher soil moisture rate .Therefor,the diffusion coefficient(D) of chloride ions in soil increased consistently with soil moisture,Although a near linear increase in the diffusion coefficient with increasing soil moisture or bulk density in all the soils was observed,the increase rate in different soils was not the same.The D value increased with teperature,and with temperature increased by 10℃ in the range from 5℃to 45℃ the D valve increased by 10%-30%,averaging about 20%.

  8. Prediction of soil organic carbon concentration and soil bulk density of mineral soils for soil organic carbon stock estimation

    Science.gov (United States)

    Putku, Elsa; Astover, Alar; Ritz, Christian

    2016-04-01

    Soil monitoring networks provide a powerful base for estimating and predicting nation's soil status in many aspects. The datasets of soil monitoring are often hierarchically structured demanding sophisticated data analyzing methods. The National Soil Monitoring of Estonia was based on a hierarchical data sampling scheme as each of the monitoring site was divided into four transects with 10 sampling points on each transect. We hypothesized that the hierarchical structure in Estonian Soil Monitoring network data requires a multi-level mixed model approach to achieve good prediction accuracy of soil properties. We used this database to predict soil bulk density and soil organic carbon concentration of mineral soils in arable land using different statistical methods: median approach, linear regression and mixed model; additionally, random forests for SOC concentration. We compared the prediction results and selected the model with the best prediction accuracy to estimate soil organic carbon stock. The mixed model approach achieved the best prediction accuracy in both soil organic carbon (RMSE 0.22%) and bulk density (RMSE 0.09 g cm-3) prediction. Other considered methods under- or overestimated higher and lower values of soil parameters. Thus, using these predictions we calculated the soil organic carbon stock of mineral arable soils and applied the model to a specific case of Tartu County in Estonia. Average estimated SOC stock of Tartu County is 54.8 t C ha-1 and total topsoil SOC stock 1.8 Tg in humus horizon.

  9. On valence electron density, energy dissipation and plasticity of bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Pang, J.J.; Tan, M.J. [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 639798 Singapore (Singapore); Liew, K.M., E-mail: kmliew@cityu.edu.hk [Department of Civil and Architectural Engineering, City University of Hong Kong, Kowloon (Hong Kong)

    2013-11-15

    Highlights: ► Relationship between valence electron density and plasticity of metallic glasses. ► Poisson's ratio increases as electron density decreases. ► Energy dissipation proposed to understand plasticity. ► Low electron density indicates small activation energy. -- Abstract: In conventional crystalline alloys, valence electron density (VED) is one of the most significant factors in determining their phase stability and mechanical properties. Extending the concept to metallic glasses (MGs), it is found, not totally surprisingly, that their mechanical properties are VED-dependent as in crystalline alloys. Interestingly, the whole VED region can be separated into two zones: Zone 1 consists of Mg-, Ca-, and RE-based (RE for rare earth) alloys; Zone 2 consists of the rest of MGs. In either zone, for each type of MGs, Poisson's ratio generally decreases as VED increases. From the energy dissipation viewpoint proposed recently, the amorphous plasticity is closely related to the activation energy for the operation of shear-transformation-zones (STZs). Smaller STZ activation energy suggests higher ductility because STZs with lower activation energy are able to convert deformation work more efficiently into configurational energy rather than heat, which yields mechanical softening and advances the growth of shear bands (SBs). Following this model, it is revealed that the activation energies for STZ operation and crystallization are certainly proportional to VED. Thus, it is understood that, in Zone 2, MGs have a smaller VED and hence lower activation energies which are favorable for ductility and Poisson's ratio. In Zone 1, MGs have the lowest VED but apparent brittleness because either of low glass transition temperature and poor resistance to oxidation or of a large fraction of covalent bonds.

  10. Analysis of physical demands during bulk bag closing and sealing.

    Science.gov (United States)

    Nasarwanji, Mahiyar F; Reardon, Leanna M; Heberger, John R; Dempsey, Patrick G

    2016-05-01

    Several tools are sold and recommended for closing and sealing flexible intermediate bulk containers (bulk bags) which are used to transport product that has been mined and processed. However, there is limited information on the risks, physical demands, or the benefits of using one tool over another. The purpose of this study was to evaluate the physical demands involved with two closing methods and several sealing tools in order to provide recommendations for selecting tools to reduce exposure to risk factors for work-related musculoskeletal disorders. In this study, twelve participants completed bag closing and sealing tasks using two different closing methods and eight sealing tools on two types of bulk bags. Physical demands and performance were evaluated using muscle activity, perceived exertion, subjective ratings of use, and time. Results indicate that using the "flowering" method to close bags required on average 32% less muscle activity, 30% less perceived exertion, 42% less time, and was preferred by participants compared to using the "snaking" method. For sealing, there was no single method significantly better across all measures; however, using a pneumatic cable tie gun consistently had the lowest muscle activity and perceived exertion ratings. The pneumatic cable tie gun did require approximately 33% more time to seal the bag compared to methods without a tool, but the amount of time to seal the bag was comparable to using other tools. Further, sealing a spout bulk bag required on average 13% less muscle activity, 18% less perceived exertion, 35% less time, and was preferred by participants compared to sealing a duffle bulk bag. The current results suggest that closing the spout bag using the flowering method and sealing the bag using the pneumatic cable tie gun that is installed with a tool balancer is ergonomically advantageous. Our findings can help organizations select methods and tools that pose the lowest physical demands when closing and

  11. Evaluating effect of surface state density at the interfaces in degraded bulk heterojunction organic solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Swati, E-mail: drswatia@yahoo.com [Department of Physics, Zakir Husain College, University of Delhi, Delhi 110002 (India); Singh, Vinamrita [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Arora, Manoj [Department of Physics, Ramjas College, University of Delhi, Delhi 110007 (India); Pal Tandon, Ram [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

    2012-08-01

    Degradation and short shelf life have been observed experimentally in poly(3-hexylthiophene) (P3HT): 6,6-phenyl C61-butyric acid methyl ester (PCBM) based blend solar cells. Both dark and illuminated current-voltage characteristics could be explained quantitatively with a proposed single model for a typical degraded organic solar cell-glass/ITO/PEDOT:PSS/P3HT:PCBM/Al. It has been found that surface state density, interface thickness, tunneling coefficient and occupation probabilities of the interface states becomes important with the passage of time. To look into the problem the activity at ITO/PEDOT:PSS and P3HT:PCBM/Al interfaces are studied using realistic values of the interfaces. The experimental J-V characteristics is well explained with the inclusion of tunneling current through these surface states and becomes the dominant current component for the degraded cell. It is also found that surface state density increases to 10{sup 12}-10{sup 13} cm{sup -2} eV{sup -1}, which has been verified with C-V measurements and also is in agreement with our proposed model for BHJ solar cell after 150 h of fabrication.

  12. The effect of fracture density and stress state on the static and dynamic bulk moduli of Westerly granite

    Science.gov (United States)

    Blake, O. O.; Faulkner, D. R.

    2016-04-01

    Elastic properties are key parameters during the deformation of rocks. They can be measured statically or dynamically, but the two measurements are often different. In this study, the static and dynamic bulk moduli (Kstatic and Kdynamic) were measured at varying effective stress for dry and fluid-saturated Westerly granite with controlled fracture densities under isotropic and differential stress states. Isotropic fracturing of different densities was induced in samples by thermal treatment to 250, 450, 650, and 850°C. Results show that fluid saturation does not greatly affect static moduli but increases dynamic moduli. Under isotropic loading, high fracture density and/or low effective pressure results in a low Kstatic/Kdynamic ratio. For dry conditions Kstatic/Kdynamic approaches 1 at low fracture densities when the effective pressure is high, consistent with previous studies. Stress-induced anisotropy exists under differential stress state that greatly affects Kstatic compared to Kdynamic. As a result, the Kstatic/Kdynamic ratio is higher than that for the isotropic stress state and approaches 1 with increasing axial loading. The effect of stress-induced anisotropy increases with increasing fracture density. A key omission in previous studies comparing static and dynamic properties is that anisotropy has not been considered. The standard methods for measuring static elastic properties, such as Poisson's ratio, Young's and shear modulus, involve subjecting the sample to a differential stress state that promotes anisotropy. Our results show that stress-induced anisotropy resulting from differential stress state is a major contributor to the difference between static and dynamic elasticity and is dominant with high fracture density.

  13. Solvation of ions in bulk and at interfaces: What can density functional theory teach us?

    Science.gov (United States)

    Mundy, Christopher

    2012-02-01

    Insights from molecular simulation have influenced both experiment and theory regarding the understanding of the specific ion effect. Although there seems to be a consensus that large polarizable anions exist at the air-water interface, the understanding of the precise molecular interactions that give rise to surface adsorption remain elusive. I will present our work on the adsorption of iodide at the air-water interface using density functional theory (DFT) based interaction potentials. I will discuss similarities and differences of the results obtained using different descriptions of molecular interaction. Last, we are able to reconcile the results obtained with molecular simulation using standard empirical potentials with the dielectric continuum theory of Levin and co-workers.[4pt] In collaboration with Marcel Baer, Pacific Northwest National Laboratory; Douglas Tobias, Abe Stern, University of California, Irvine, CA; and Yan Levin, Instituto de F'isica, UFRGS, Porto Alegre, RS, 91501-970, Brazil.

  14. Reduction of crack density in ammonothermal bulk GaN growth

    Science.gov (United States)

    Letts, Edward; Key, Daryl; Hashimoto, Tadao

    2016-12-01

    The growth of high quality GaN by the ammonothermal method is appealing due to the potential to scale and achieve very high crystal quality. Several applications could benefit from the supply of very high quality GaN such as high power light emitting diodes, laser diodes, and high power electronics. Despite steady advancement by the few groups developing ammonothermal growth technology, high quality ammonothermal GaN wafers have yet be manufactured in great quantities. This paper reviews the current progress of ammonothermal growth at SixPoint Materials. Growths were performed at TX-ray diffraction was carried out on an ammonothermally grown boule at 90 points along a 44 mm line providing a mean (002) and (201) full width half max (FWHM) reflection of 29 and 35″ respectively using a beam spot of 0.3 mm x 0.3 mm and an open detector. The radius of curvature is typically between 3 and 20 m across the sample. Dislocation densities are routinely low 105 cm-2 .

  15. Thermocline bulk shear analysis in the northern North Sea

    Science.gov (United States)

    Chen, Shengli; Polton, Jeff A.; Hu, Jianyu; Xing, Jiuxing

    2016-04-01

    Thermocline bulk shear is investigated in the northern North Sea using historical observations. The conventional bulk shear is modified to define a thermocline bulk shear (TBS), in order to better represent the shear across the thermocline. The TBS computed by observed currents is decomposed into components at different frequency bands. The near-inertial TBS is the largest component. Its dominance is significant during the period of high wind. It is formed by the wind-driven near-inertial current which has a distinct phase shift (˜180°) across the thermocline. A linear model is presented, which well simulates the observed near-inertial TBS, especially during the period of relatively strong wind. The semidiurnal TBS makes a secondary contribution to the total TBS. It is only slightly smaller than the near-inertial TBS when the wind is relatively weak. The large values of semidiurnal TBS are associated with semidiurnal currents which have a phase shift (˜30-40°) or a magnitude difference (˜5 cm/s) across the thermocline. The low-frequency (<0.7 cpd) TBS also makes an episodic contribution to the total. Its variation coincides with the Ekman transport during the period of relatively strong wind. The low-frequency TBS is mainly formed by an Ekman-like clockwise spiraling of velocity with depth or a distinct magnitude difference in velocities between upper and lower layers.

  16. Quantum information aspects on bulk and nano interacting Fermi system: A spin-space density matrix approach

    Science.gov (United States)

    Afzali, R.; Ebrahimian, N.; Eghbalifar, B.

    2016-10-01

    By approximating the energy gap, entering nano-size effect via gap fluctuation and calculating the Green's functions and the space-spin density matrix, the dependence of quantum correlation (entanglement, discord and tripartite entanglement) on the relative distance of two electron spins forming Cooper pairs, the energy gap and the length of bulk and nano interacting Fermi system (a nodal d-wave superconductor) is determined. In contrast to a s-wave superconductor, quantum correlation of the system is sensitive to the change of the gap magnitude and strongly depends on the length of the grain. Also, quantum discord oscillates. Furthermore, the entanglement length and the correlation length are investigated. Discord becomes zero at a characteristic length of the d-wave superconductor.

  17. Influence of optical interference and carrier lifetime on the short circuit current density of organic bulk heterojunction solar cells

    Institute of Scientific and Technical Information of China (English)

    You Hai-Long; Zhang Chun-Fu

    2009-01-01

    Based on simple analytical equations, short circuit current density (Jsc) of the organic bulk heterojunction solar cells has been calculated. It is found that the optical interference effect plays a very important role in the determination of JSC;and obvious oscillatory behaviour of Jsc was observed as a function of thickness. At the same time, the influence of JSC only increases the carrier lifetime on JSC also cannot be neglected. When the carrier lifetime is relatively short, at the initial stage and then decreases rapidly with the increase of active layer thickness. However, for a relatively long carrier lifetime, the exciton dissociation probability must be considered, and Jsc behaves wave-like with the increase of active layer thickness. The validity of this model is confirmed by the experimental results.

  18. Influence of Critical Current Density on Guidance Force Decay of HTS Bulk Exposed to AC Magnetic Field Perturbation in a Maglev Vehicle System

    Science.gov (United States)

    Longcai, Zhang; Jianguo, Kong

    2012-07-01

    Superconducting maglev vehicle is one of the most promising applications of HTS bulks. In such a system, the HTS bulks are always exposed to AC external magnetic field, which is generated by the inhomogeneous surface magnetic field of the NdFeB guideway. In our previous work, we studied the guidance force decay of the YBCO bulk over the NdFdB guideway used in the High-temperature superconducting maglev vehicle system with the application of the AC external magnetic field, and calculated the guidance force decay as a function of time based on an analytic model. In this paper, we investigated the influence of the critical current density on the guidance force decay of HTS bulk exposed to AC field perturbation in the maglev vehicle system and try to adopt a method to suppress the decay. From the results, it was found that the guidance force decay rate was higher for the bulk with lower critical current density. Therefore, we could suppress the guidance force decay of HTS bulk exposed to AC external magnetic field perturbation in the maglev vehicle system by improving critical current density of the bulk.

  19. A comparative study of the density of defect states in bulk samples and thin films of glassy Se$_{90}$Sb$_{10}$

    Indian Academy of Sciences (India)

    KUMAR ANJANI; DWIVEDI PRABHAT K; SHUKLA R K; KUMAR A

    2016-05-01

    The present paper reports the comparative study of density of defect states (DOS) between bulk samples and thin films of glassy Se$_{90}$Sb$_{10}$. These glasses have been prepared by the quenching technique. Thin films of these glasses have been prepared by vacuum evaporation technique. Space-charge-limited conduction (SCLC) has been measured at different temperatures.The density of localized states near Fermi level is calculated by fitting the data to the theory of SCLC for the case of uniform distribution of localized states for bulk as well as for thin films. A comparison has been made between the density of states calculated in these two cases.

  20. Econometric Analysis of Bulk Shipping: implications for investment strategies and financial decision-making

    OpenAIRE

    Tsolakis, S.

    2005-01-01

    textabstractThis thesis provides an econometric analysis of the bulk shipping markets and the implications for shipping investment and financial decision making. Chapter 1 sets the scene by providing a historic analysis of bulk shipping markets over the last 55 years. From this analysis, four shipping markets (freight, newbuilding, second-hand and demolition) are distinguished as well as a fifth one (ship finance) that acts as a facilitator to the other four. Also, with the help of correlatio...

  1. Developing a Penetrometer-Based Mapping System for Visualizing Silage Bulk Density from the Bunker Silo Face

    Science.gov (United States)

    Li, Menghua; Jungbluth, Kerstin H.; Sun, Yurui; Cheng, Qiang; Maack, Christian; Buescher, Wolfgang; Lin, Jianhui; Zhou, Haiyang; Wang, Zhongyi

    2016-01-01

    For silage production, high bulk density (BD) is critical to minimize aerobic deterioration facilitated by oxygen intrusion. To precisely assess packing quality for bunker silos, there is a desire to visualize the BD distribution within the silage. In this study, a penetrometer-based mapping system was developed. The data processing included filtering of the penetration friction component (PFC) out of the penetration resistance (PR), transfer of the corrected penetration resistance (PRc) to BD, incorporation of Kriged interpolation for data expansion and map generation. The experiment was conducted in a maize bunker silo (width: 8 m, middle height: 3 m). The BD distributions near the bunker silo face were represented using two map groups, one related to horizontal- and the other to vertical-density distribution patterns. We also presented a comparison between the map-based BD results and core sampling data. Agreement between the two measurement approaches (RMSE = 19.175 kg·m−3) demonstrates that the developed penetrometer mapping system may be beneficial for rapid assessment of aerobic deterioration potential in bunker silos. PMID:27399703

  2. Developing a Penetrometer-Based Mapping System for Visualizing Silage Bulk Density from the Bunker Silo Face

    Directory of Open Access Journals (Sweden)

    Menghua Li

    2016-07-01

    Full Text Available For silage production, high bulk density (BD is critical to minimize aerobic deterioration facilitated by oxygen intrusion. To precisely assess packing quality for bunker silos, there is a desire to visualize the BD distribution within the silage. In this study, a penetrometer-based mapping system was developed. The data processing included filtering of the penetration friction component (PFC out of the penetration resistance (PR, transfer of the corrected penetration resistance (PRc to BD, incorporation of Kriged interpolation for data expansion and map generation. The experiment was conducted in a maize bunker silo (width: 8 m, middle height: 3 m. The BD distributions near the bunker silo face were represented using two map groups, one related to horizontal- and the other to vertical-density distribution patterns. We also presented a comparison between the map-based BD results and core sampling data. Agreement between the two measurement approaches (RMSE = 19.175 kg·m−3 demonstrates that the developed penetrometer mapping system may be beneficial for rapid assessment of aerobic deterioration potential in bunker silos.

  3. Developing a Penetrometer-Based Mapping System for Visualizing Silage Bulk Density from the Bunker Silo Face.

    Science.gov (United States)

    Li, Menghua; Jungbluth, Kerstin H; Sun, Yurui; Cheng, Qiang; Maack, Christian; Buescher, Wolfgang; Lin, Jianhui; Zhou, Haiyang; Wang, Zhongyi

    2016-07-05

    For silage production, high bulk density (BD) is critical to minimize aerobic deterioration facilitated by oxygen intrusion. To precisely assess packing quality for bunker silos, there is a desire to visualize the BD distribution within the silage. In this study, a penetrometer-based mapping system was developed. The data processing included filtering of the penetration friction component (PFC) out of the penetration resistance (PR), transfer of the corrected penetration resistance (PRc) to BD, incorporation of Kriged interpolation for data expansion and map generation. The experiment was conducted in a maize bunker silo (width: 8 m, middle height: 3 m). The BD distributions near the bunker silo face were represented using two map groups, one related to horizontal- and the other to vertical-density distribution patterns. We also presented a comparison between the map-based BD results and core sampling data. Agreement between the two measurement approaches (RMSE = 19.175 kg·m(-3)) demonstrates that the developed penetrometer mapping system may be beneficial for rapid assessment of aerobic deterioration potential in bunker silos.

  4. Targets for bulk hydrogen analysis using thermal neutrons

    CERN Document Server

    Csikai, J; Buczko, C M

    2002-01-01

    The reflection property of substances can be characterized by the reflection cross-section of thermal neutrons, sigma subbeta. A combination of the targets with thin polyethylene foils allowed an estimation of the flux depression of thermal neutrons caused by a bulk sample containing highly absorbing elements or compounds. Some new and more accurate sigma subbeta values were determined by using the combined target arrangement. For the ratio, R of the reflection and the elastic scattering cross-sections of thermal neutrons, R=sigma subbeta/sigma sub E sub L a value of 0.60+-0.02 was found on the basis of the data obtained for a number of elements from H to Pb. Using this correlation factor, and the sigma sub E sub L values, the unknown sigma subbeta data can be deduced. The equivalent thicknesses, to polyethylene or hydrogen, of the different target materials were determined from the sigma subbeta values.

  5. FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, J.

    2010-06-02

    The Bulk Tritium Shipping Package was designed by Savannah River National Laboratory. This package will be used to transport tritium. As part of the requirements for certification, the package must be shown to meet the scenarios of the Hypothetical Accident Conditions (HAC) defined in Code of Federal Regulations Title 10 Part 71 (10CFR71). The conditions include a sequential 30-foot drop event, 30-foot dynamic crush event, and a 40-inch puncture event. Finite Element analyses were performed to support and expand upon prototype testing. Cases similar to the tests were evaluated. Additional temperatures and orientations were also examined to determine their impact on the results. The peak stress on the package was shown to be acceptable. In addition, the strain on the outer drum as well as the inner containment boundary was shown to be acceptable. In conjunction with the prototype tests, the package was shown to meet its confinement requirements.

  6. AB-INITIO STUDY OF BULK MODULUS AND CHARGE DENSITY OF CUBIC SrMO3 PEROVSKITES (M = Ti, Zr, Mo, Rh, Ru

    Directory of Open Access Journals (Sweden)

    AVINASH DAGA

    2012-03-01

    Full Text Available Bulk modulus & charge density of cubic SrMO3 perovskites (M = Ti, Zr, Mo, Rh & Ru have been investigated systematically using the first principle density functional calculations. Local density approximation (LDAmethod has been used to compute the two quantities for five perovskites. It is found that the calculated bulk modulus for all the transition metal oxides are in good agreement with the available experimental data and with other theoretical results previously reported in the literature. ABINIT computer code is used to carry out all the calculations. Charge density plots for all the five cubic SrMO3 perovskites have been drawn using MATLAB. The maximum and minimum values of charge density along with the corresponding reduced coordinates are reported for all the perovskites.

  7. Effects of "natural" water and "added" water on prediction of moisture content and bulk density of shelled corn from microwave dielectric properties.

    Science.gov (United States)

    Trabelsi, Samir; Nelson, Stuart O; Lewis, Micah A

    2010-01-01

    Dielectric properties of samples of shelled corn of "natural" water content and those prepared by adding water were measured in free space at microwave frequencies and 23 degrees C. Results of measurements of attenuation, phase shift and dielectric constant and loss factor at 9 GHz show no difference between the samples with "natural" water and those in which water was added artificially. Bulk densities and moisture contents predicted from calibration equations expressed in terms of dielectric properties of both natural and added water samples agreed closely, and standard errors were less than 1% for moisture content and relative error for bulk density was less than 5%.

  8. Tunnel geometry of the subterranean termite Reticulitermes grassei (Isoptera: Rhinotermitidae) in response to sand bulk density and the presence of food

    Institute of Scientific and Technical Information of China (English)

    T(A)NIA NOBRE; LINA NUNES; DAVID E. BIGNELL

    2007-01-01

    The cryptic habits of subterranean termites restricts detailed analysis of their foraging patterns in situ, but the process is evidently dominated by tunnel constructions connecting the nest with woody resources discovered within the territory of each colony.In this study, tunnel formation and orientation were studied experimentally in the termite taining fine sand as the substratum. The building of exploratory tunnels over a 10-day period and the geometry of the resulting network are described. Fractal analysis showed that tunnel geometry had a fractal dimension, regardless of the total length tunnelled whether foragers encountered the food source or not. The bulk density of the sand in the arenas affected the distances tunnelled, with higher density reducing construction, but did not affect tunnel geometry. Tunnels were not discernibly orientated with respect to the positioning of the food source, even in a situation where termites had failed to find the food source at a distance of less than 50 mm, suggesting that volatiles from wood are not attractants.

  9. Development of bulk density, total C distribution and OC saturation in fine mineral fractions during paddy soil evolution

    Science.gov (United States)

    Wissing, Livia; Kölbl, Angelika; Cao, Zhi-Hong; Kögel-Knabner, Ingrid

    2010-05-01

    Paddy soils are described as important accumulator for OM (Zhang and He, 2004). In southeast China, paddy soils have the second highest OM stocks (Zhao et al, 1997) and thus a large proportion of the terrestrial carbon is conserved in wetland rice soils. The paddy soil management is believed to be favorable for accumulation of organic matter, as its content in paddy soils is statistically higher than that of non-paddy soils (Cai, 1996). However, the mechanism of OM storage and the development of OM distribution during paddy soil evolution is largely unknown. The aim of the project is to identify the role of organo-mineral complexes for the stabilization of organic carbon during management-induced paddy soil formation in a chronosequence ranging from 50 to 2000 years of paddy soil use. The soil samples were analysed for bulk density, total organic carbon (TOC) and total inorganic carbon (TIC) concentrations of bulk soils and the concentration of organic carbon as well as the organic carbon stocks of physical soil fractions. First results indicate distinctly different depth distributions between paddy and non-paddy (control) sites. The paddy soils are characterized by relatively low bulk densities in the puddled layer (between 0.9 and 1.3 g cm-3) and high values in the plough pan (1.4 to 1.6 g cm-3) and the non-paddy soils by relatively homogeneous values throughout the profiles (1.3 to 1.4 g cm-3). In contrast to the carbonate-rich non-paddy sites, we found a significant loss of carbonates during paddy soil formation, resulting in decalcification of the upper 20 cm after 100 yr of paddy soil use, and decalcification of the total soil profile in 700, 1000 and 2000 yr old paddy soils. The calculation of the organic carbon stocks of each horizon indicate that paddy sites always have higher values in topsoils compared to non-paddy sites, and show increasing values with increasing soil age. The capacity of fine mineral fractions to preserve OC was calculated according to

  10. The enhancement of critical current density on the bulk of BPSCCO-system superconductor with silver additions

    Energy Technology Data Exchange (ETDEWEB)

    Engkir Sukirman; Wisnu Ari Adi; Puji Sulisworo dan W. Prasuad [Materials Science Research Center, BATAN, Serpong (Indonesia)

    1999-10-01

    The influence of silver additions on the critical current density (Jc) of BPSCCO-bulk superconductor was investigated, with the aim of getting an increase of its Jc and trying to find out a correlation of Jc and structures of BPSCCO-silver composites. The BPSCCO-system superconductors with nominal composition Bi{sub 1.84}Pb{sub 0.34}Sr{sub 2.00}Ca{sub 2.03}Cu{sub 3.06}O{sub x} (2223-phase) were synthesized by using solid state reaction method. The silver added was in the powder-AgO form varied from 0 to 30 wt % AgO. The critical current density, crystal structure, and micro-structure of BPSCCO-silver composites were characterized by means of four-point probe, x-ray diffractometer, and scanning electron microscope that is equipped with a link system energy dispersive spectrometer. It was found that silver additions to BPSCCO cause a reasonable improvement in Jc from 120 to 215 A/cm{sup 2}, and a slight increase in Tc from 92 to 108 K, and lattice parameters of the 2223-phase from a 3.811(3) to 3.820(2) A, and from c = 37.08(3) to 37.15(2) A, with the optimum value occurs at 20 wt % AgO. The AgO powders added to the BPSCCO specimens were converted to Ag{sub 2}O and metallic Ag during the annealing process at 827degC for 96 h in air. The addition of AgO to BPSCCO system does not necessarily lead to decomposition of the 2223-phase. The AgO reacts with and suppresses the 2201-phase. (author)

  11. Enhancement of glass-forming ability of Fe-based bulk metallic glasses with high saturation magnetic flux density

    Directory of Open Access Journals (Sweden)

    Mingxiao Zhang

    2012-06-01

    Full Text Available The effects of substituting Fe with Ni on thermal properties, glass-forming ability (GFA and magnetic properties of Fe76-xNixMo3.5P10C4B4Si2.5 (x = 0−30 at.% alloys were investigated in detail. The breadth of the supercooled liquid region was found to gradually increase from 42 to 55 K with increasing Ni content to 30 at.%. When x = 5 at.%, the alloy composition approached a eutectic point, resulting in an increase in GFA. As a result, FeNiMoPCBSi bulk metallic glasses with critical diameters up to 5.5 mm were successfully synthesized by copper mold casting. These glassy alloys exhibit a high saturation magnetic flux density of 0.75−1.21 T and excellent soft magnetic properties, i.e., low coercive force of 1.1−2.0 A/m, and high effective permeability of 14400−19700 at 1 kHz under a field of 1 A/m. The reasons for the high stability of the supercooled liquid, and the high GFA as well as excellent soft magnetic properties are discussed in this article.

  12. Complexity Analysis of Peat Soil Density Distribution

    Science.gov (United States)

    Sampurno, Joko; Diah Faryuni, Irfana; Dzar Eljabbar Latief, Fourier; Srigutomo, Wahyu

    2016-08-01

    The distributions of peat soil density have been identified using fractal analysis method. The study was conducted on 5 peat soil samples taken from a ground field in Pontianak, West Kalimantan, at the coordinates (0 ° 4 '2:27 "S, 109 ° 18' 48.59" E). In this study, we used micro computerized tomography (pCT Scanner) at 9.41 micro meter per pixel resolution under peat soil samples to provide 2-D high-resolution images L1-L5 (200 200 pixels) that were used to detect the distribution of peat soil density. The method for determining the fractal dimension and intercept was the 2-D Fourier analysis method. The method was used to obtain the log log-plot of magnitude with frequency. Fractal dimension was obtained from the straight regression line that interpolated the points in the interval with the largest coefficient determination. Intercept defined by the point of intersection on the -axis. The conclusion was that the distributions of peat soil density showing the fractal behaviour with the heterogeneity of the samples from the highest to the lowest were L5, L1, L4, L3 and L2. Meanwhile, the range of density values of the samples from the highest to the lowest was L3, L2, L4, L5 and L1. The study also concluded that the behaviour of the distribution of peat soil density was a weakly anisotropic.

  13. A Peak in Density Dependence of Electron Spin Relaxation Time in n-Type Bulk GaAs in the Metallic Regime

    Institute of Scientific and Technical Information of China (English)

    SHEN Ka

    2009-01-01

    We demonstrate that the peak in the density dependence of electron spin relaxation time in n-type bulk GaAs in the metallic regime predicted by Jiang and Wu[Phys.Rev.B 79 (2009) 125206]has been realized experimentally in the latest work[arXiv:0902.0270]by Krauβ et al.

  14. SWOT analysis for safer carriage of bulk liquid chemicals in tankers.

    Science.gov (United States)

    Arslan, Ozcan; Er, Ismail Deha

    2008-06-15

    The application of strengths, weaknesses, opportunities and threats (SWOT) analysis to formulation of strategy concerned with the safe carriage of bulk liquid chemicals in maritime tankers was examined in this study. A qualitative investigation using SWOT analysis has been implemented successfully for ships that are designed to carry liquid chemicals in bulk. The originality of this study lies in the use of SWOT analysis as a management tool to formulate strategic action plans for ship management companies, ship masters and officers for the carriage of dangerous goods in bulk. With this transportation-based SWOT analysis, efforts were made to explore the ways and means of converting possible threats into opportunities, and changing weaknesses into strengths; and strategic plans of action were developed for safer tanker operation.

  15. Gamma self-shielding correction factors calculation for aqueous bulk sample analysis by PGNAA technique

    Energy Technology Data Exchange (ETDEWEB)

    Nasrabadi, M.N. [Department of Nuclear Engineering, Faculty of Modern Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)], E-mail: mnnasrabadi@ast.ui.ac.ir; Mohammadi, A. [Department of Physics, Payame Noor University (PNU), Kohandej, Isfahan (Iran, Islamic Republic of); Jalali, M. [Isfahan Nuclear Science and Technology Research Institute (NSTRT), Reactor and Accelerators Research and Development School, Atomic Energy Organization of Iran (Iran, Islamic Republic of)

    2009-07-15

    In this paper bulk sample prompt gamma neutron activation analysis (BSPGNAA) was applied to aqueous sample analysis using a relative method. For elemental analysis of an unknown bulk sample, gamma self-shielding coefficient was required. Gamma self-shielding coefficient of unknown samples was estimated by an experimental method and also by MCNP code calculation. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the gamma self-shielding within the sample volume is required.

  16. Molecular markers of nuclear restoration gene Rf1 in sunflower using bulked segregant analysis-RAPD

    Institute of Scientific and Technical Information of China (English)

    季静; 王罡; E.Belhassen; H.Serieys; A.Berville

    1996-01-01

    Restoration of cytoplasmic male sterility (CMS) in sunflower was demonstrated to be controlled by polygenes by analysing 982 effective crosses among 109 self-crossed lines and 16 CMS lines. Two self-crossed lines and one CMS line with distinct genotypes were applied to creation of segregating populations for DNA bulks of the target gene Rfl. Bulked DNA was prepared in order to investigate single gene Rfl and its gene marker among polygenic characters at the same genetic background. Using 80 10-mer operon primers, 620 RAPD reactions were carried out between fertile and sterile DNA bulks. In about 800 loci, primary results showed that 8 were related to the restoration genes. Furthermore. 2 were confirmed as RAPD markers for gene Rfl by examining 9 maintenance and 7 restoration lines. This method is the improvement for bulked segregant analysis[1] with which markers of single gene of target can be identified rapidly among polygenic characters.

  17. Prompt Gamma Activation Analysis (PGAA): Technique of choice for nondestructive bulk analysis of returned comet samples

    Science.gov (United States)

    Lindstrom, David J.; Lindstrom, Richard M.

    1989-01-01

    Prompt gamma activation analysis (PGAA) is a well-developed analytical technique. The technique involves irradiation of samples in an external neutron beam from a nuclear reactor, with simultaneous counting of gamma rays produced in the sample by neutron capture. Capture of neutrons leads to excited nuclei which decay immediately with the emission of energetic gamma rays to the ground state. PGAA has several advantages over other techniques for the analysis of cometary materials: (1) It is nondestructive; (2) It can be used to determine abundances of a wide variety of elements, including most major and minor elements (Na, Mg, Al, Si, P, K, Ca, Ti, Cr, Mn, Fe, Co, Ni), volatiles (H, C, N, F, Cl, S), and some trace elements (those with high neutron capture cross sections, including B, Cd, Nd, Sm, and Gd); and (3) It is a true bulk analysis technique. Recent developments should improve the technique's sensitivity and accuracy considerably.

  18. Laboratory Performance of Five Selected Soil Moisture Sensors Applying Factory and Own Calibration Equations for Two Soil Media of Different Bulk Density and Salinity Levels.

    Science.gov (United States)

    Matula, Svatopluk; Báťková, Kamila; Legese, Wossenu Lemma

    2016-11-15

    Non-destructive soil water content determination is a fundamental component for many agricultural and environmental applications. The accuracy and costs of the sensors define the measurement scheme and the ability to fit the natural heterogeneous conditions. The aim of this study was to evaluate five commercially available and relatively cheap sensors usually grouped with impedance and FDR sensors. ThetaProbe ML2x (impedance) and ECH₂O EC-10, ECH₂O EC-20, ECH₂O EC-5, and ECH₂O TE (all FDR) were tested on silica sand and loess of defined characteristics under controlled laboratory conditions. The calibrations were carried out in nine consecutive soil water contents from dry to saturated conditions (pure water and saline water). The gravimetric method was used as a reference method for the statistical evaluation (ANOVA with significance level 0.05). Generally, the results showed that our own calibrations led to more accurate soil moisture estimates. Variance component analysis arranged the factors contributing to the total variation as follows: calibration (contributed 42%), sensor type (contributed 29%), material (contributed 18%), and dry bulk density (contributed 11%). All the tested sensors performed very well within the whole range of water content, especially the sensors ECH₂O EC-5 and ECH₂O TE, which also performed surprisingly well in saline conditions.

  19. Use of thermal neutron reflection method for chemical analysis of bulk samples

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A., E-mail: papppa@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI), 4001 Debrecen, Pf. 51 (Hungary); Csikai, J. [Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI), 4001 Debrecen, Pf. 51 (Hungary); Institute of Experimental Physics, University Debrecen (IEP), 4010 Debrecen-10, Pf. 105 (Hungary)

    2014-09-11

    Microscopic, σ{sub β}, and macroscopic, Σ{sub β}, reflection cross-sections of thermal neutrons averaged over bulk samples as a function of thickness (z) are given. The σ{sub β} values are additive even for bulk samples in the z=0.5–8 cm interval and so the σ{sub βmol}(z) function could be given for hydrogenous substances, including some illicit drugs, explosives and hiding materials of ∼1000 cm{sup 3} dimensions. The calculated excess counts agree with the measured R(z) values. For the identification of concealed objects and chemical analysis of bulky samples, different neutron methods need to be used simultaneously. - Highlights: • Check the proposed analytical expression for the description of the flux. • Determination of the reflection cross-sections averaged over bulk samples. • Data rendered to estimate the excess counts for various materials.

  20. Effect of Long-term Minimal and Zero Tillages on Rice and Wheat Yields,Soil Organic Matter and Bulk Density

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A long-term experiment of minimal and zero tillages was carried out on the sandy loam soil from 1985~1996. The results showed that the yields of minimal tillaged rice and wheat were similar to those by conventional tillage. Zero-tillaged wheat yield increased by 5.3% on average, while the zero-tillaged rice yield reduced by 2. 2%. The yields under long-term minimal and zero tillages showed no obvious temporal trend. After five years of the experiment, the soil organic matter contents were in steady state under different tillages, but its distributions in soil layers were different markedly and the richness in upper layer was observed under minimal and zero tillages, with the richness coefficients of 1. 1140 and 1. 1608, on 7-year average ,respectively. The bulk densities among different tillages were insignificantly different in soil layers of 0~7cm and 14~21cm. In the soil layer of 7~14cm,the bulk densities under conventional, minimal and zero tillages were 1.348,1.412 and 1. 410 g/cm3 respectively, minimal and zero tillages resulted in obvious increases in the bulk density.

  1. Analysis of bacterial community in bulking sludge using culture-dependent and -independent approaches

    Institute of Scientific and Technical Information of China (English)

    Decai Jin; Ping Wang; Zhihui Bai; Xinxin Wang; Hong Peng; Rong Qi; Zhisheng Yu; Guoqiang Zhuang

    2011-01-01

    The bacterial community of a bulking sludge from a municipal wastewater treatment plant with anoxic-anaerobic-oxic process was investigated by combination of cultivation and 16S rRNA gene clone library analysis for understanding the causes of bulking.A total of 28 species were obtained from 63 isolates collected from six culture media.The most cultivable species belonged to γ-Proteobacteria including Klebsiella sp.,Pseudomonas sp.,Aeromonas sp.and Acinetobacter sp.Further analysis of these strains by repetitive sequence based on polymerase chain reaction (rep-PCR) technology showed that rep-PCR yielded discriminatory banding patterns within the same genus using REP and BOX primer sets.While the culture-independent assessment revealed that β-Proteobacteria was the dominant group in the bulking sample.Sequence analysis revealed that the highest proportion (14.7%) of operational taxonomic units was 98% similar to Candidatus Accumulibacter phosphatis,which is used to remove phosphorous from wastewater.Our results indicated that combining different approaches can produce complementary information,thus generate a more accurate view of microbial community in bulking sludge.

  2. Determining the spatial variability of wetland soil bulk density, organic matter, and the conversion factor between organic matter and organic carbon across coastal Louisiana, U.S.A.

    Science.gov (United States)

    Wang, Hongqing; Piazza, Sarai C.; Sharp, Leigh A.; Stagg, Camille L.; Couvillion, Brady R.; Steyer, Gregory D.; McGinnis, Thomas E.

    2016-01-01

    Soil bulk density (BD), soil organic matter (SOM) content, and a conversion factor between SOM and soil organic carbon (SOC) are often used in estimating SOC sequestration and storage. Spatial variability in BD, SOM, and the SOM–SOC conversion factor affects the ability to accurately estimate SOC sequestration, storage, and the benefits (e.g., land building area and vertical accretion) associated with wetland restoration efforts, such as marsh creation and sediment diversions. There are, however, only a few studies that have examined large-scale spatial variability in BD, SOM, and SOM–SOC conversion factors in coastal wetlands. In this study, soil cores, distributed across the entire coastal Louisiana (approximately 14,667 km2) were used to examine the regional-scale spatial variability in BD, SOM, and the SOM–SOC conversion factor. Soil cores for BD and SOM analyses were collected during 2006–09 from 331 spatially well-distributed sites in the Coastwide Reference Monitoring System network. Soil cores for the SOM–SOC conversion factor analysis were collected from 15 sites across coastal Louisiana during 2006–07. Results of a split-plot analysis of variance with incomplete block design indicated that BD and SOM varied significantly at a landscape level, defined by both hydrologic basins and vegetation types. Vertically, BD and SOM varied significantly among different vegetation types. The SOM–SOC conversion factor also varied significantly at the landscape level. This study provides critical information for the assessment of the role of coastal wetlands in large regional carbon budgets and the estimation of carbon credits from coastal restoration.

  3. An experimental measurement of the coexistence curve and critical temperature, density and pressure of bulk nuclear matter

    CERN Document Server

    Elliott, J B; Moretto, L G; Phair, L

    2012-01-01

    Infinite, neutron-proton symmetric, neutral nuclear matter has a critical temperature of 17.9+-0.4 MeV, a critical density of 0.06+-0.01 nucleons per cubic fermi and a critical pressure of 0.31+-0.07 MeV per cubic fermi. These values have been obtained from our analysis of data from six different reactions studied in three different experiments: two "compound nuclear" reactions: 58Ni+12C-->70Se and 64Ni+12C-->76Se (both performed at the LBNL 88" Cyclotron) and four "multifragmentation" reactions: 1 GeV/c pi+197Au (performed by the ISiS collaboration), 1 AGeV 197Au+C, 1 AGeV 139La+12C and 1 AGeV 84Kr+12C (all performed by the EOS collaboration). The charge yields of all reactions as a function of excitation energy were fit with a version of Fisher's droplet model modified to account for the dual components of the fluid (i.e. protons and neutrons), Coulomb effects, finite size effects and angular momentum arising from the nuclear collisions.

  4. Superior critical current density obtained in MgB2 bulks via employing carbon-coated boron and minor Cu addition

    Science.gov (United States)

    Peng, Junming; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M.; Xin, Ying; Jin, Jianxun

    2016-09-01

    High performance Cu doped MgB2 bulks were prepared by an in-situ method with carbon-coated amorphous boron as precursor. It was found that the usage of carbon-coated boron in present work leads to the formation of uniformly refined MgB2 grains, as well as a high level of homogeneous carbon doping in the MgB2 samples, which significantly enhance the Jc in both Cu doped and undoped bulks compared to MgB2 bulks with normal amorphous boron precursor. Moreover, minor Cu can service as activator, and thus facilitates the growth of MgB2 grains and improves crystallinity and grain connectivity, which can bring about the excellent critical current density (Jc) at self fields and low fields (the best values are 7 × 105 A/cm2 at self fields, and 1 × 105 A/cm2 at 2 T, 20 K, respectively). Simultaneously, minor Cu addition can reduce the amount of MgO impurity significantly, also contributing to the improvement of Jc at low fields. Our work suggests that Cu-activated sintering combined with employment of carbon-coated amorphous boron as precursor could be a promising technique to produce practical MgB2 bulks or wires with excellent Jc on an industrial scale.

  5. Incidence densities in a competing events analysis.

    Science.gov (United States)

    Grambauer, Nadine; Schumacher, Martin; Dettenkofer, Markus; Beyersmann, Jan

    2010-11-01

    Epidemiologists often study the incidence density (ID; also known as incidence rate), which is the number of observed events divided by population-time at risk. Its computational simplicity makes it attractive in applications, but a common concern is that the ID is misleading if the underlying hazard is not constant in time. Another difficulty arises if competing events are present, which seems to have attracted less attention in the literature. However, there are situations in which the presence of competing events obscures the analysis more than nonconstant hazards do. The authors illustrate such a situation using data on infectious complications in patients receiving stem cell transplants, showing that a certain transplant type reduces the infection ID but eventually increases the cumulative infection probability because of its effect on the competing event. The authors investigate the extent to which IDs allow for a reasonable analysis of competing events. They suggest a simple multistate-type graphic based on IDs, which immediately displays the competing event situation. The authors also suggest a more formal summary analysis in terms of a best approximating effect on the cumulative event probability, considering another data example of US women infected with human immunodeficiency virus. Competing events and even more complex event patterns may be adequately addressed with the suggested methodology.

  6. Reliability of AlGaN/GaN high electron mobility transistors on low dislocation density bulk GaN substrate: Implications of surface step edges

    Energy Technology Data Exchange (ETDEWEB)

    Killat, N., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk; Montes Bajo, M.; Kuball, M., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk [Center for Device Thermography and Reliability (CDTR), H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Paskova, T. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Materials Science and Engineering Department, North Carolina State University, Raleigh, North Carolina 27695 (United States); Evans, K. R. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Leach, J. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Li, X.; Özgür, Ü.; Morkoç, H. [Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Chabak, K. D.; Crespo, A.; Gillespie, J. K.; Fitch, R.; Kossler, M.; Walker, D. E.; Trejo, M.; Via, G. D.; Blevins, J. D. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

    2013-11-04

    To enable gaining insight into degradation mechanisms of AlGaN/GaN high electron mobility transistors, devices grown on a low-dislocation-density bulk-GaN substrate were studied. Gate leakage current and electroluminescence (EL) monitoring revealed a progressive appearance of EL spots during off-state stress which signify the generation of gate current leakage paths. Atomic force microscopy evidenced the formation of semiconductor surface pits at the failure location, which corresponds to the interaction region of the gate contact edge and the edges of surface steps.

  7. Climatic features of the Mediterranean Sea detected by the analysis of the longwave radiative bulk formulae

    Directory of Open Access Journals (Sweden)

    M. E. Schiano

    Full Text Available Some important climatic features of the Mediterranean Sea stand out from an analysis of the systematic discrepancies between direct measurements of longwave radiation budget and predictions obtained by the most widely used bulk formulae. In particular, under clear-sky conditions the results show that the surface values of both air temperature and humidity over the Mediterranean Sea are larger than those expected over an open ocean with the same amount of net longwave radiation. Furthermore, the twofold climatic regime of the Mediterranean region strongly affects the downwelling clear-sky radiation. This study suggests that a single bulk formula with constant numerical coefficients is unable to reproduce the fluxes at the surface for all the seasons.

    Key words: Meteorology and Atmospheric dynamics (radiative processes – Oceanography: general (marginal and semienclosed seas; marine meteorology

  8. Glass Formation, Chemical Properties and Surface Analysis of Cu-Based Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Akihisa Inoue

    2011-04-01

    Full Text Available This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs. In order to obtain basic knowledge for application to the industry, corrosion resistance of the Cu–Hf–Ti–(Mo, Nb, Ta, Ni and Cu–Zr–Ag–Al–(Nb bulk glassy alloy systems in various solutions are reported in this work. Moreover, X-ray photoelectron spectroscopy (XPS analysis is performed to clarify the surface-related chemical characteristics of the alloy before and after immersion in the solutions; this has lead to a better understanding of the correlation between the surface composition and the corrosion resistance.

  9. Glass-forming ability analysis of selected Fe-based bulk amorphous alloys

    Directory of Open Access Journals (Sweden)

    R. Nowosielski

    2010-09-01

    Full Text Available Purpose: The paper mainly aims to present the structure and thermal stability of selected Fe-based bulk metallic glasses: Fe72B20Si4Nb4 and Fe43Co14Ni14B20Si5Nb4.Design/methodology/approach: The investigated samples were cast in form of the rods by the pressure die casting method. The structure analysis of the studied materials in as-cast state was carried out using XRD and TEM methods. The thermal stability associated with glass transition temperature (Tg, onset (Tx and peak (Tp crystallization temperature was examined by differential scanning calorimetry (DSC. Several parameters have been used to determine the glass-forming ability of studied alloys. The parameters of GFA included reduced glass transition temperature (Trg, supercooled liquid region (ΔTx, the stability (S and (Kgl parameter.Findings: The XRD and TEM investigations revealed that the studied as-cast metallic glasses were fully amorphous. Changes of the onset and peak crystallization temperature and the glass transition temperature as a function of glassy samples thickness were stated. The good glass-forming ability (GFA enabled casting of the Fe72B20Si4Nb4 and Fe43Co14Ni14B20Si5Nb4 glassy rods.Practical implications: The obtained examination results confirm the utility of applied investigation methods in the thermal stability analysis of examined bulk amorphous alloys. It is evident that parameters Trg, ΔTx, Kgl, S could be used to determine glass-forming ability of studied bulk metallic glasses.Originality/value: The success of fabrication of studied Fe-based bulk metallic glasses in form of rods with diameter up to 3 mm is important for the future progress in research of this group of materials.

  10. Microwave Dielectric Sensing of Moisture Content in Shelled Peanuts Independent of Bulk Density and with Temperature Compensation

    Science.gov (United States)

    A dielectric method for rapid and nondestructive sensing of moisture content in shelled peanuts from free space measurement of attenuation, phase shift, and their corresponding dielectric properties at microwave frequencies is presented. Results of moisture prediction with three density-independent...

  11. International Conference on Harmonisation; Guidance on Q4B Evaluation and Recommendation of Pharmacopoeial Texts for Use in the International Conference on Harmonisation Regions; Annex 13 on Bulk Density and Tapped Density of Powders General Chapter; availability. Notice.

    Science.gov (United States)

    2013-05-28

    The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled "Q4B Evaluation and Recommendation of Pharmacopoeial Texts for Use in the International Conference on Harmonisation Regions; Annex 13: Bulk Density and Tapped Density of Powders General Chapter.'' The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance provides the results of the ICH Q4B evaluation of the Bulk Density and Tapped Density of Powders General Chapter harmonized text from each of the three pharmacopoeias (United States, European, and Japanese) represented by the Pharmacopoeial Discussion Group (PDG). The guidance conveys recognition of the three pharmacopoeial methods by the three ICH regulatory regions and provides specific information regarding the recognition. The guidance is intended to recognize the interchangeability between the local regional pharmacopoeias, thus avoiding redundant testing in favor of a common testing strategy in each regulatory region. The guidance is in the form of an annex to the core guidance on the Q4B process entitled ``Q4B Evaluation and Recommendation of Pharmacopoeial Texts for Use in the ICH Regions (core ICH Q4B guidance).

  12. Reliability analysis of the bulk cargo loading system including dependent components

    Science.gov (United States)

    Blokus-Roszkowska, Agnieszka

    2016-06-01

    In the paper an innovative approach to the reliability analysis of multistate series-parallel systems assuming their components' dependency is presented. The reliability function of a multistate series system with components dependent according to the local load sharing rule is determined. Linking these results for series systems with results for parallel systems with independent components, we obtain the reliability function of a multistate series-parallel system assuming dependence of components' departures from the reliability states subsets in series subsystem and assuming independence between these subsystems. As a particular case, the reliability function of a multistate series-parallel system composed of dependent components having exponential reliability functions is fixed. Theoretical results are applied practically to the reliability evaluation of a bulk cargo transportation system, which main area is to load bulk cargo on board the ships. The reliability function and other reliability characteristics of the loading system are determined in case its components have exponential reliability functions with interdependent departures rates from the subsets of their reliability states. Finally, the obtained results are compared with results for the bulk cargo transportation system composed of independent components.

  13. Mechanical relaxation in a Zr-based bulk metallic glass: Analysis based on physical models

    Science.gov (United States)

    Qiao, J. C.; Pelletier, J. M.

    2012-08-01

    The mechanical relaxation behavior in a Zr55Cu30Ni5Al10 bulk metallic glass is investigated by dynamic mechanical analysis in both temperature and frequency domains. Master curves can be obtained for the storage modulus G' and for the loss modulus G'', confirming the validity of the time-temperature superposition principle. Different models are discussed to describe the main (α) relaxation, e.g., Debye model, Havriliak-Negami (HN) model, Kohlrausch-Williams-Watt (KWW) model, and quasi-point defects (QPDs) model. The main relaxation in bulk metallic glass cannot be described using a single relaxation time. The HN model, the KWW model, and the QPD theory can be used to fit the data of mechanical spectroscopy experiments. However, unlike the HN model and the KWW model, some physical parameters are introduced in QPD model, i.e., atomic mobility and correlation factor, giving, therefore, a new physical approach to understand the mechanical relaxation in bulk metallic glasses.

  14. Analysis of Temperature and Humidity Field in a New Bulk Tobacco Curing Barn Based on CFD

    Science.gov (United States)

    Bai, Zhipeng; Guo, Duoduo; Li, Shoucang; Hu, Yaohua

    2017-01-01

    A new structure bulk tobacco curing barn was presented. To study the temperature and humidity field in the new structure tobacco curing barn, a 3D transient computational fluid dynamics (CFD) model was developed using porous medium, species transport, κ-ε turbulence and discrete phase models. The CFD results demonstrated that (1) the temperature and relative humidity predictions were validated by the experimental results, and comparison of simulation results with experimental data showed a fairly close agreement; (2) the temperature of the bottom and inlet area was higher than the top and outlet area, and water vapor concentrated on the top and outlet area in the barn; (3) tobacco loading density and thickness of tobacco leaves had an explicit effect on the temperature distributions in the barn. PMID:28146128

  15. High-Resolution Sedimentation Rates at IODP Sites U1424 and U1427 since the late Pliocene from spectral-analyzing GRA Bulk Density and RGB Color Profiles

    Science.gov (United States)

    Gorgas, Thomas; Irino, Tomohisa; Tada, Ryuji

    2016-04-01

    Sedimentation Rates (SRs) for IODP Sites U1424 (lat/lon coordinates: 40o11.40'N, 138o13.90'E; water depth: 2808 mbsl) and U1427 (lat/lon coordinates: 35o57.92'N, 134o26.06'E; water depth: 330 mbsl) were calculated by performing spectral analysis in the depth domain on both RGB color and Gamma-Ray-Attenuation (GRA) bulk density data. Inversion and integration of SRs versus depth from spectral analysis yielded detailed SR profiles in both time and depth domains. Our results show a greater variability in calculated SRs and differed from those established through coarse-scaled biostratigraphy and paleo-magnetic data. Our data analyses produces pulses of distinct high SRs for certain depth/age intervals at both sites, with time lags for such features possibly due to variable oceanographic conditions near-shore for Site U1427 versus those at Site U1424 further offshore. Both GRA and RGB profiles reveal a distinct periodicity in the waveband of Milankovitch cycles and other prominent periodicities in the 10-to-1ky period range. This observation suggests climate variabilities and trends in SRs responding to insolation patterns during the past 1 Myr at both sites and extending to 4.5 Myr for Site U1424. With only few identified eccentricity (100ky) cycle segments throughout the entire normalized spectral amplitude profile, our high-resolution Age-Depth model was tuned to obliquity (41ky) and precessional (19-23ky) cycles to achieving a strong fit with corresponding low-resolution models based on biostratigraphy, paleo-magnetic and, at least for Site U1424, augmenting volcanostratigraphy data. According to our Age-Depth models, relatively low SRs occur when evolutive amplitude spectra are dominated by periods in the range of obliquity and eccentricity. In contrast, significant SR peaks at both sites often occur when strong precessional amplitudes coexist with all other cycles. Lower SRs at Site U1424 have been interpreted to reflect a decrease in diatom flux and relative

  16. Critical Analysis on the Structural and Magnetic Properties of Bulk and Nanocrystalline Cu-Fe-O

    Directory of Open Access Journals (Sweden)

    D. Paul Joseph

    2010-01-01

    Full Text Available Nanocrystalline and bulk samples of “Fe”-doped CuO were prepared by coprecipitation and ceramic methods. Structural and compositional analyses were performed using X-ray diffraction, SEM, and EDAX. Traces of secondary phases such as CuFe2O4, Fe3O4, and α-Fe2O3 having peaks very close to that of the host CuO were identified from the Rietveld profile analysis and the SAED pattern of bulk and nanocrystalline Cu0.98Fe0.02O samples. Vibrating Sample Magnetometer (VSM measurements show hysteresis at 300 K for all the samples. The ferrimagnetic Neel transition temperature ( was found to be around 465°C irrespective of the content of “Fe”, which is close to the value of cubic CuFe2O4. High-pressure X-Ray diffraction studies were performed on 2% “Fe”-doped bulk CuO using synchrotron radiation. From the absence of any strong new peaks at high pressure, it is evident that the secondary phases if present could be less than the level of detection. Cu2O, which is diamagnetic by nature, was also doped with 1% of “Fe” and was found to show paramagnetic behavior in contrast to the “Fe” doped CuO. Hence the possibility of intrinsic magnetization of “Fe”-doped CuO apart from the secondary phases is discussed based on the magnetization and charge state of “Fe” and the host into which it is substituted.

  17. Universal solvation model based on solute electron density and on a continuum model of the solvent defined by the bulk dielectric constant and atomic surface tensions.

    Science.gov (United States)

    Marenich, Aleksandr V; Cramer, Christopher J; Truhlar, Donald G

    2009-05-07

    We present a new continuum solvation model based on the quantum mechanical charge density of a solute molecule interacting with a continuum description of the solvent. The model is called SMD, where the "D" stands for "density" to denote that the full solute electron density is used without defining partial atomic charges. "Continuum" denotes that the solvent is not represented explicitly but rather as a dielectric medium with surface tension at the solute-solvent boundary. SMD is a universal solvation model, where "universal" denotes its applicability to any charged or uncharged solute in any solvent or liquid medium for which a few key descriptors are known (in particular, dielectric constant, refractive index, bulk surface tension, and acidity and basicity parameters). The model separates the observable solvation free energy into two main components. The first component is the bulk electrostatic contribution arising from a self-consistent reaction field treatment that involves the solution of the nonhomogeneous Poisson equation for electrostatics in terms of the integral-equation-formalism polarizable continuum model (IEF-PCM). The cavities for the bulk electrostatic calculation are defined by superpositions of nuclear-centered spheres. The second component is called the cavity-dispersion-solvent-structure term and is the contribution arising from short-range interactions between the solute and solvent molecules in the first solvation shell. This contribution is a sum of terms that are proportional (with geometry-dependent proportionality constants called atomic surface tensions) to the solvent-accessible surface areas of the individual atoms of the solute. The SMD model has been parametrized with a training set of 2821 solvation data including 112 aqueous ionic solvation free energies, 220 solvation free energies for 166 ions in acetonitrile, methanol, and dimethyl sulfoxide, 2346 solvation free energies for 318 neutral solutes in 91 solvents (90 nonaqueous

  18. Mapping QTLs for Salt Tolerance in Rice (Oryza sativa L.) by Bulked Segregant Analysis of Recombinant Inbred Lines Using 50K SNP Chip.

    Science.gov (United States)

    Tiwari, Sushma; Sl, Krishnamurthy; Kumar, Vinod; Singh, Balwant; Rao, A R; Mithra Sv, Amitha; Rai, Vandna; Singh, Ashok K; Singh, Nagendra K

    2016-01-01

    Soil salinity is a major constraint to rice production in large inland and coastal areas around the world. Modern high yielding rice varieties are particularly sensitive to high salt stress. There are salt tolerant landraces and traditional varieties of rice but with limited information on genomic regions (QTLs) and genes responsible for their tolerance. Here we describe a method for rapid identification of QTLs for reproductive stage salt tolerance in rice using bulked segregant analysis (BSA) of bi-parental recombinant inbred lines (RIL). The number of RILs required for the creation of two bulks with extreme phenotypes was optimized to be thirty each. The parents and bulks were genotyped using a 50K SNP chip to identify genomic regions showing homogeneity for contrasting alleles of polymorphic SNPs in the two bulks. The method was applied to 'CSR11/MI48' RILs segregating for reproductive stage salt tolerance. Genotyping of the parents and RIL bulks, made on the basis of salt sensitivity index for grain yield, revealed 6,068 polymorphic SNPs and 21 QTL regions showing homogeneity of contrasting alleles in the two bulks. The method was validated further with 'CSR27/MI48' RILs used earlier for mapping salt tolerance QTLs using low-density SSR markers. BSA with 50K SNP chip revealed 5,021 polymorphic loci and 34 QTL regions. This not only confirmed the location of previously mapped QTLs but also identified several new QTLs, and provided a rapid way to scan the whole genome for mapping QTLs for complex agronomic traits in rice.

  19. Mapping QTLs for Salt Tolerance in Rice (Oryza sativa L.) by Bulked Segregant Analysis of Recombinant Inbred Lines Using 50K SNP Chip

    Science.gov (United States)

    Kumar, Vinod; Singh, Balwant; Rao, AR; Mithra SV, Amitha; Singh, Ashok K.; Singh, Nagendra K.

    2016-01-01

    Soil salinity is a major constraint to rice production in large inland and coastal areas around the world. Modern high yielding rice varieties are particularly sensitive to high salt stress. There are salt tolerant landraces and traditional varieties of rice but with limited information on genomic regions (QTLs) and genes responsible for their tolerance. Here we describe a method for rapid identification of QTLs for reproductive stage salt tolerance in rice using bulked segregant analysis (BSA) of bi-parental recombinant inbred lines (RIL). The number of RILs required for the creation of two bulks with extreme phenotypes was optimized to be thirty each. The parents and bulks were genotyped using a 50K SNP chip to identify genomic regions showing homogeneity for contrasting alleles of polymorphic SNPs in the two bulks. The method was applied to ‘CSR11/MI48’ RILs segregating for reproductive stage salt tolerance. Genotyping of the parents and RIL bulks, made on the basis of salt sensitivity index for grain yield, revealed 6,068 polymorphic SNPs and 21 QTL regions showing homogeneity of contrasting alleles in the two bulks. The method was validated further with ‘CSR27/MI48’ RILs used earlier for mapping salt tolerance QTLs using low-density SSR markers. BSA with 50K SNP chip revealed 5,021 polymorphic loci and 34 QTL regions. This not only confirmed the location of previously mapped QTLs but also identified several new QTLs, and provided a rapid way to scan the whole genome for mapping QTLs for complex agronomic traits in rice. PMID:27077373

  20. Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis.

    Science.gov (United States)

    Wilde, Markus; Ohno, Satoshi; Ogura, Shohei; Fukutani, Katsuyuki; Matsuzaki, Hiroyuki

    2016-03-29

    Nuclear reaction analysis (NRA) via the resonant (1)H((15)N,αγ)(12)C reaction is a highly effective method of depth profiling that quantitatively and non-destructively reveals the hydrogen density distribution at surfaces, at interfaces, and in the volume of solid materials with high depth resolution. The technique applies a (15)N ion beam of 6.385 MeV provided by an electrostatic accelerator and specifically detects the (1)H isotope in depths up to about 2 μm from the target surface. Surface H coverages are measured with a sensitivity in the order of ~10(13) cm(-2) (~1% of a typical atomic monolayer density) and H volume concentrations with a detection limit of ~10(18) cm(-3) (~100 at. ppm). The near-surface depth resolution is 2-5 nm for surface-normal (15)N ion incidence onto the target and can be enhanced to values below 1 nm for very flat targets by adopting a surface-grazing incidence geometry. The method is versatile and readily applied to any high vacuum compatible homogeneous material with a smooth surface (no pores). Electrically conductive targets usually tolerate the ion beam irradiation with negligible degradation. Hydrogen quantitation and correct depth analysis require knowledge of the elementary composition (besides hydrogen) and mass density of the target material. Especially in combination with ultra-high vacuum methods for in-situ target preparation and characterization, (1)H((15)N,αγ)(12)C NRA is ideally suited for hydrogen analysis at atomically controlled surfaces and nanostructured interfaces. We exemplarily demonstrate here the application of (15)N NRA at the MALT Tandem accelerator facility of the University of Tokyo to (1) quantitatively measure the surface coverage and the bulk concentration of hydrogen in the near-surface region of a H2 exposed Pd(110) single crystal, and (2) to determine the depth location and layer density of hydrogen near the interfaces of thin SiO2 films on Si(100).

  1. Frequency domain analysis of lamb wave scattering and application to film bulk acoustic wave resonators.

    Science.gov (United States)

    Thalmayr, Florian; Hashimoto, Ken-Ya; Omori, Tatsuya; Yamaguchi, Masatsune

    2010-07-01

    This paper demonstrates a novel frequency domain analysis (FDA) to evaluate the scattering behavior of a waveguide mode at arbitrary scattering geometries by a time harmonic simulation based on the finite element method (FEM). To this end, we add an injection-damping mechanism (IDM) to avoid interference at the acoustic input port. The IDM can be easily constructed by a numerical operation. Our approach offers improved time consumption and calculation power necessary over the established method in the time domain. After checking the validity of the proposed method, we discuss the importance of considering wave scattering phenomena in film bulk acoustic wave resonator (FBAR) devices by applying the proposed method to two simplified models of an FBAR device.

  2. Dispersion-Corrected Density Functional Theory Investigations of Structural and Electronic Properties of Bulk MoS2: Effect of Uniaxial Strain.

    Science.gov (United States)

    Nguyen, Chuong V; Hieu, Nguyen N; Nguyen, Duong T

    2015-12-01

    Strain-dependent structural and electronic properties of MoS2 materials are investigated using first principles calculations. The structural and electronic band structures of the MoS2 with relaxed unit cells are optimized and calculated by the dispersion-corrected density functional theory (DFT-D2). Calculations within the local density approximation (LDA) and GGA using PAW potentials were also performed for specific cases for the purpose of comparison. The effect of strain on the band gap and the dependence of formation energy on strain of MoS2 are also studied and discussed using the DFT-D2 method. In bulk MoS2, the orbitals shift towards the higher/lower energy area when strain is applied along the z/x direction, respectively. The energy splitting of Mo4d states is in the range from 0 to 2 eV, which is due to the reduction of the electronic band gap of MoS2.

  3. Cluster analysis on the bulk elemental compositions of Antarctic stony meteorites

    Science.gov (United States)

    Miyamoto, Hideaki; Niihara, Takafumi; Kuritani, Takeshi; Hong, Peng K.; Dohm, James M.; Sugita, Seiji

    2016-05-01

    Remote sensing observations by recent successful missions to small bodies have revealed the difficulty in classifying the materials which cover their surfaces into a conventional classification of meteorites. Although reflectance spectroscopy is a powerful tool for this purpose, it is influenced by many factors, such as space weathering, lighting conditions, and surface physical conditions (e.g., particle size and style of mixing). Thus, complementary information, such as elemental compositions, which can be obtained by X-ray fluorescence (XRF) and gamma-ray spectrometers (GRS), have been considered very important. However, classifying planetary materials solely based on elemental compositions has not been investigated extensively. In this study, we perform principal component and cluster analyses on 12 major and minor elements of the bulk compositions of 500 meteorites reported in the National Institute of Polar Research (NIPR), Japan database. Our unique approach, which includes using hierarchical cluster analysis, indicates that meteorites can be classified into about 10 groups purely by their bulk elemental compositions. We suggest that Si, Fe, Mg, Ca, and Na are the optimal set of elements, as this set has been used successfully to classify meteorites of the NIPR database with more than 94% accuracy. Principal components analysis indicates that elemental compositions of meteorites form eight clusters in the three-dimensional space of the components. The three major principal components (PC1, PC2, and PC3) are interpreted as (1) degree of differentiations of the source body (i.e., primitive versus differentiated), (2) degree of thermal effects, and (3) degree of chemical fractionation, respectively.

  4. Elemental Analysis and Comparison of Bulk Soil Using LA-ICP-MS and LIBS methods

    Science.gov (United States)

    Almirall, J.

    2012-04-01

    Elemental analysis methods utilizing Laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) were developed and used in the characterization of soil samples from the US and Canada as part of a comprehensive forensic evaluation of soils. A LA-ICP-MS method was recently optimized for analysis and comparison between different soil samples in an environmental forensic application [1,2] and LIBS has recently attracted the interest of analytical chemists and forensic laboratories as a simpler, lower cost alternative to the more established analytical methods. In developing a LIBS method, there are many parameters to consider, including laser wavelength, spectral resolution, sensitivity, and matrix effects. The first LIBS method using a 266 nm laser for forensic soil analysis has also been recently reported by our group [3]. The results of an inter-laboratory comparison involving thirteen (13) laboratories conducting bulk elemental analysis by various methods are also reported. The aims of the inter-laboratory tests were: a) to evaluate the inter-laboratory performance of three methods (LA-ICP-MS, µXRF and LIBS) in terms of accuracy (bias), precision (relative standard deviation, RSD) and sensitivity using standard reference materials (SRMs); b) to evaluate the newly released NIST SRM 2710a, which supersedes 2710; and c) to evaluate the utility of LIBS as an alternative technique to LA-ICP-MS and µXRF for bulk analysis of soils. Each sample and standard was homogenized in a high-speed ball mill and pressed into pellets. Participants were instructed to measure the following elements: 7Li, 25Mg, 27Al, 42Ca, 45Sc, 47,49Ti, 51V, 55Mn, 88Sr, 137Ba, 206,207,208 Pb (LA-ICP-MS); Ti, Cr, Mn, Fe, Cu, Sr, Zr, Pb (µXRF); Ba, Cr, Cu, Fe, Li, Mg, Mn, Pb, Sr, Ti, Zr (LIBS). For both LIBS and µXRF, the choice of appropriate spectral lines was determined by the user, optimizing for linearity, sensitivity and precision

  5. Neutron Flux Density Measured by Analysis of Annealing Heat

    Institute of Scientific and Technical Information of China (English)

    WANG; Fan; SHI; Yong-qian; ZHU; Qing-fu; LU; Jin; LI; Lai-dong

    2015-01-01

    Neutron flux density measurement by thermal analysis is a new method different from the previous.This method is first put the sample to the neutron field.Second,measure the annealingheat of the sample.Find out the suitable mixture of crystal boron and apatite to measure the neutron flux density.Then put the sample to the neutron field in

  6. Density functional and neural network analysis

    DEFF Research Database (Denmark)

    Jalkanen, K. J.; Bohr, Henrik

    1997-01-01

    dichroism (VCD) intensities. The large changes due to hydration on the structures, relative stability of conformers, and in the VA and VCD spectra observed experimentally are reproduced by the DFT calculations. Furthermore a neural network was constructed for reproducing the inverse scattering data (infer...... the structural coordinates from spectroscopic data) that the DFT method could produce. Finally the neural network performances are used to monitor a sensitivity or dependence analysis of the importance of secondary structures....

  7. Genetic Mapping by Bulk Segregant Analysis in Drosophila: Experimental Design and Simulation-Based Inference.

    Science.gov (United States)

    Pool, John E

    2016-11-01

    Identifying the genomic regions that underlie complex phenotypic variation is a key challenge in modern biology. Many approaches to quantitative trait locus mapping in animal and plant species suffer from limited power and genomic resolution. Here, I investigate whether bulk segregant analysis (BSA), which has been successfully applied for yeast, may have utility in the genomic era for trait mapping in Drosophila (and other organisms that can be experimentally bred in similar numbers). I perform simulations to investigate the statistical signal of a quantitative trait locus (QTL) in a wide range of BSA and introgression mapping (IM) experiments. BSA consistently provides more accurate mapping signals than IM (in addition to allowing the mapping of multiple traits from the same experimental population). The performance of BSA and IM is maximized by having multiple independent crosses, more generations of interbreeding, larger numbers of breeding individuals, and greater genotyping effort, but is less affected by the proportion of individuals selected for phenotypic extreme pools. I also introduce a prototype analysis method for simulation-based inference for BSA mapping (SIBSAM). This method identifies significant QTL and estimates their genomic confidence intervals and relative effect sizes. Importantly, it also tests whether overlapping peaks should be considered as two distinct QTL. This approach will facilitate improved trait mapping in Drosophila and other species for which hundreds or thousands of offspring (but not millions) can be studied.

  8. Predicting available water of soil from particle-size distribution and bulk density in an oasis-desert transect in northwestern China

    Science.gov (United States)

    Li, Danfeng; Gao, Guangyao; Shao, Ming'an; Fu, Bojie

    2016-07-01

    A detailed understanding of soil hydraulic properties, particularly the available water content of soil, (AW, cm3 cm-3), is required for optimal water management. Direct measurement of soil hydraulic properties is impractical for large scale application, but routinely available soil particle-size distribution (PSD) and bulk density can be used as proxies to develop various prediction functions. In this study, we compared the performance of the Arya and Paris (AP) model, Mohammadi and Vanclooster (MV) model, Arya and Heitman (AH) model, and Rosetta program in predicting the soil water characteristic curve (SWCC) at 34 points with experimental SWCC data in an oasis-desert transect (20 × 5 km) in the middle reaches of the Heihe River basin, northwestern China. The idea of the three models emerges from the similarity of the shapes of the PSD and SWCC. The AP model, MV model, and Rosetta program performed better in predicting the SWCC than the AH model. The AW determined from the SWCCs predicted by the MV model agreed better with the experimental values than those derived from the AP model and Rosetta program. The fine-textured soils were characterized by higher AW values, while the sandy soils had lower AW values. The MV model has the advantages of having robust physical basis, being independent of database-related parameters, and involving subclasses of texture data. These features make it promising in predicting soil water retention at regional scales, serving for the application of hydrological models and the optimization of soil water management.

  9. Comet formation in collapsing pebble clouds. What cometary bulk density implies for the cloud mass and dust-to-ice ratio

    CERN Document Server

    Lorek, S; Lacerda, P; Blum, J

    2016-01-01

    Comets are remnants of the icy planetesimals that formed beyond the ice line in the Solar Nebula. Growing from micrometre-sized dust and ice particles to km-sized objects is, however, difficult because of growth barriers and time scale constraints. The gravitational collapse of pebble clouds that formed through the streaming instability may provide a suitable mechanism for comet formation. We study the collisional compression of cm-sized porous ice/dust-mixed pebbles in collapsing pebble clouds. For this, we developed a collision model for pebbles consisting of a mixture of ice and dust, characterised by their dust-to-ice mass ratio. Using the final compression of the pebbles, we constrain combinations of initial cloud mass, initial pepple porosity, and dust-to-ice ratio that lead to cometesimals which are consistent with observed bulk properties of cometary nuclei. We find that observed high porosity and low density of ~0.5 g/cc of comet nuclei can only be explained if comets formed in clouds with mass appro...

  10. Determination of Lubricant Bulk Modulus in Metal Forming by Means of a Simple Laboratory Test and Inverse FEM Analysis

    DEFF Research Database (Denmark)

    Hafis, S. M.; Christiansen, P.; Martins, P. A. F.

    2016-01-01

    The influence of workpiece surface topography on friction, lubrication and final surface equality in metal forming operations is well known and has been pointed out by many researchers.This is especially the case when liquid lubricants are applied in situations, where increased surface roughness...... a simple, practical test to determine the bulk modulus. Combination of the experimental upsetting of an axisymmetric metal workpiece containing a truncated conical surface pocket with an inverse finite element analysis of the test allows determining the lubricant bulk modulus. The finite element analysis...... couples lubricant flow with plastic deformation of the metal directly. Results show that the proposed procedure allows determining an approximate bulk modulus for the lubricant....

  11. Quantitative Trait Loci Mapping for Bacterial Blight Resistance in Rice Using Bulked Segregant Analysis

    Directory of Open Access Journals (Sweden)

    Xueying Han

    2014-07-01

    Full Text Available Oryza meyeriana is highly resistant to rice bacterial blight (BB and this resistance trait has been transferred to cultivated rice (O. sativa using asymmetric somatic hybridization. However, no resistance genes have yet been cloned. In the present study, a progeny of the somatic hybridization with high BB resistance was crossed with a rice cultivar with high BB susceptibility to develop an F2 population. Using bulked segregant analysis (BSA, 17 polymorphic markers that were linked to rice BB resistance were obtained through scanning a total of 186 simple sequence repeats (SSR and sequence-tagged site (STS markers, evenly distributed on 12 chromosomes. A genetic linkage map was then constructed based on the 17 linkage markers and the F2 segregating population, which was followed by mapping for quantitative trait loci (QTLs for BB resistance. Three QTLs were identified on chromosomes 1, 3 and 5, respectively, and the alleles of the resistant parent at any of the QTLs increased BB resistance. All of the three QTLs had a strong effect on resistance, explaining about 21.5%, 12.3% and 39.2% of the resistance variance, respectively. These QTLs were different from the loci of the BB resistance genes that have been identified in previous studies. The QTLs mapped in this work will facilitate the isolation of novel BB resistance genes and their utilization in rice resistance breeding.

  12. Assessment of Functional EST-SSR Markers (Sugarcane in Cross-Species Transferability, Genetic Diversity among Poaceae Plants, and Bulk Segregation Analysis

    Directory of Open Access Journals (Sweden)

    Shamshad Ul Haq

    2016-01-01

    Full Text Available Expressed sequence tags (ESTs are important resource for gene discovery, gene expression and its regulation, molecular marker development, and comparative genomics. We procured 10000 ESTs and analyzed 267 EST-SSRs markers through computational approach. The average density was one SSR/10.45 kb or 6.4% frequency, wherein trinucleotide repeats (66.74% were the most abundant followed by di- (26.10%, tetra- (4.67%, penta- (1.5%, and hexanucleotide (1.2% repeats. Functional annotations were done and after-effect newly developed 63 EST-SSRs were used for cross transferability, genetic diversity, and bulk segregation analysis (BSA. Out of 63 EST-SSRs, 42 markers were identified owing to their expansion genetics across 20 different plants which amplified 519 alleles at 180 loci with an average of 2.88 alleles/locus and the polymorphic information content (PIC ranged from 0.51 to 0.93 with an average of 0.83. The cross transferability ranged from 25% for wheat to 97.22% for Schlerostachya, with an average of 55.86%, and genetic relationships were established based on diversification among them. Moreover, 10 EST-SSRs were recognized as important markers between bulks of pooled DNA of sugarcane cultivars through BSA. This study highlights the employability of the markers in transferability, genetic diversity in grass species, and distinguished sugarcane bulks.

  13. Improved linkage analysis of Quantitative Trait Loci using bulk segregants unveils a novel determinant of high ethanol tolerance in yeast

    NARCIS (Netherlands)

    Duitama, Jorge; Sánchez-Rodríguez, Aminael; Goovaerts, Annelies; Pulido-Tamayo, Sergio; Hubmann, Georg; Foulquié-Moreno, María R.; Thevelein, Johan M.; Verstrepen, Kevin J.; Marchal, Kathleen

    2014-01-01

    Background: Bulk segregant analysis (BSA) coupled to high throughput sequencing is a powerful method to map genomic regions related with phenotypes of interest. It relies on crossing two parents, one inferior and one superior for a trait of interest. Segregants displaying the trait of the superior p

  14. Multiresolution analysis of density fluctuation in supersonic mixing layer

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Due to the difficulties in measuring supersonic density field, the multiresolution analysis of supersonic mixing layer based on experimental images is still a formidable challenge. By utilizing the recently developed nanoparticle based planar laser scattering method, the density field of a supersonic mixing layer was measured at high spatiotemporal resolution. According to the dynamic behavior of coherent structures, the multiresolution characteristics of density fluctuation signals and density field images were studied based on Taylor’s hypothesis of space-time conversion and wavelet analysis. The wavelet coefficients reflect the characteristics of density fluctuation signals at different scales, and the detailed coefficients reflect the differences of approximation at adjacent levels. The density fluctuation signals of supersonic mixing layer differ from the periodic sine signal and exhibit similarity to the fractal Koch signal. The similarity at different scales reveals the fractal characteristic of mixing layer flowfield. The two-dimensional wavelet decomposition and reconstruction of density field images extract the approximate and detailed signals at different scales, which effectively resolve the characteristic structures of the flowfield at different scales.

  15. Effects of Bulk Density on Root Growth of High Yield Maize and Their Regulation%土壤容重对高产玉米根系生长的影响及调控研究

    Institute of Scientific and Technical Information of China (English)

    郑存德; 依艳丽; 张大庚; 徐龙超

    2012-01-01

    不同土壤容重不同,其稳定性也不同.土壤容重的变化会引起土壤调节水、气、热能力的变化,提高土壤的自动调节能力可以使土壤肥力水平得以提高并满足植物对生长因子的持续需求.为研究土壤物理性质对玉米高产稳产的影响机理,以耕地棕壤为试验材料,采用盆栽方法,研究不同容重对玉米根系生长指标的影响,并进一步研究了施用不同有机肥量及模拟不同耕作深度对玉米根系生长的调控效果.结果表明:在设计容重范围内,容重增加,根系生长指标都表现为下降,容重大于1.2g/m3时,不同处理根系生长指标差异显著;当容重大于1.3g/cm3时,不同处理根系活力差异显著.施用有机肥对高容重土壤调控效果更好,有机质含量为4%与5%的处理差异减小,低容重土壤在所设计的有机质水平内调控效果也都较好.耕层厚度增加可以提高根系生长参数,但与对照相比,差异不显著.所以,对于紧实结构性较差的土壤,改善其调节能力应该通过增施有机肥的方法,紧实结构较好的土壤考虑使用耕翻的办法.%Soil bulk density is one of the important soil physical properties. Different soil with different soil bulk density and stability, at the same time , soil regulation ability of soil-water, soil-gas, soil-heat capacity changed with unstability of soil bulk density. It can improve soil fertility degree and the continuing demand factors of plant growth if the soil's automatically adaptational ability was enhanced, therefore, it is necessary to research how soil bulk density vary and how to regulate and control it. In order to study the mechanism of the impact of soil physical properties on high and stable yield of maize, this paper, with cultivated brown soil and pot experiment, studied the effect of soil bulk density on maize root growth parameters( root length,root area,root volume) ,furthermore,it studied the result of regulation by

  16. Cell wall elasticity: I. A critique of the bulk elastic modulus approach and an analysis using polymer elastic principles

    Science.gov (United States)

    Wu, H. I.; Spence, R. D.; Sharpe, P. J.; Goeschl, J. D.

    1985-01-01

    The traditional bulk elastic modulus approach to plant cell pressure-volume relations is inconsistent with its definition. The relationship between the bulk modulus and Young's modulus that forms the basis of their usual application to cell pressure-volume properties is demonstrated to be physically meaningless. The bulk modulus describes stress/strain relations of solid, homogeneous bodies undergoing small deformations, whereas the plant cell is best described as a thin-shelled, fluid-filled structure with a polymer base. Because cell walls possess a polymer structure, an alternative method of mechanical analysis is presented using polymer elasticity principles. This initial study presents the groundwork of polymer mechanics as would be applied to cell walls and discusses how the matrix and microfibrillar network induce nonlinear stress/strain relationships in the cell wall in response to turgor pressure. In subsequent studies, these concepts will be expanded to include anisotropic expansion as regulated by the microfibrillar network.

  17. Latent class analysis of bulk tank milk PCR and ELISA testing for herd level diagnosis of Mycoplasma bovis

    DEFF Research Database (Denmark)

    Nielsen, Per Kantsø; Petersen, Mette Bisgaard; Nielsen, Liza Rosenbaum

    2015-01-01

    of this study was to evaluate the herd-level diagnostic performance of an indirect ELISA test by comparison to a real-time PCR test when diagnosing M. bovis in cattle herds of bulk tank milk. Bulk tank milk samples from Danish dairy herds (N=3437) were analysed with both the antibody detecting BIO K 302 M...... density Coefficient). These changed to 43.5 [21.1-92.5 95% PCI] and 99.6 [98.8-100 95% PCI] if the cut-off was increased to 50 ODC%. In addition, herd-level diagnosis by ELISA would result in fewer false positives at a cut-off value of 50 ODC% compared to 37 ODC% without compromising the negative...

  18. Design & Performance Analysis of DG-MOSFET for Reduction of Short Channel Effect over Bulk MOSFET at 20nm

    Directory of Open Access Journals (Sweden)

    Ankita Wagadre

    2014-07-01

    Full Text Available An aggressive scaling of conventional MOSFETs channel length reduces below 100nm and gate oxide thickness below 3nm to improved performance and packaging density. Due to this scaling short channel effect (SCEs like threshold voltage, Subthreshold slope, ON current and OFF current plays a major role in determining the performance of scaled devices. The double gate (DG MOSFETS are electro-statically superior to a single gate (SG MOSFET and allows for additional gate length scaling. Simulation work on both devices has been carried out and presented in paper. The comparative study had been carried out for threshold voltage (VT, Subthreshold slope (Sub VT, ION and IOFF Current. It is observed that DG MOSFET provide good control on leakage current over conventional Bulk (Single Gate MOSFET. The VT (Threshold Voltage is 2.7 times greater than & ION of DG MOSFET is 2.2 times smaller than the conventional Bulk (Single Gate MOSFET.

  19. Effects of varying bulk densities of steam-flaked corn and dietary roughage concentration on in vitro fermentation, performance, carcass quality, and acid-base balance measurements in finishing steers.

    Science.gov (United States)

    Hales, K E; McMeniman, J P; Leibovich, J; Vasconcelos, J T; Quinn, M J; May, M L; DiLorenzo, N; Smith, D R; Galyean, M L

    2010-03-01

    Effects of varying bulk densities of steam-flaked corn (SFC) and level of inclusion of roughage in feedlot diets were evaluated in 3 experiments. In Exp. 1, a total of 128 beef steers were used in a 2 x 2 factorial arrangement to evaluate the effects of bulk density of SFC (335 or 386 g/L) and roughage concentration (6 or 10% ground alfalfa hay, DM basis) on performance and carcass characteristics. No interactions were observed between bulk density and roughage concentration for performance data. From d 0 to the end, cattle fed the 335 g/L SFC had greater overall G:F (P = 0.04) than those fed the 386 g/L SFC, with tendencies (P 0.20). In Exp. 2, the effects of bulk density of SFC (283, 335, or 386 g/L) and 6 or 10% ground alfalfa hay on IVDMD and in vitro pH were evaluated at 6, 12, 18, and 24 h of incubation. With a reduced-strength buffer in vitro fermentation system, pH increased (P system, there were no treatment differences (P > 0.23) for IVDMD. In Exp. 3, two diets that varied in bulk density of SFC and roughage concentration (335 g/L SFC with 6% alfalfa hay vs. 386 g/L SFC with 10% alfalfa hay) were compared for their effects on the pattern of feed intake and the acid-base balance in Holstein steers (12/treatment). No differences (P > 0.10) between treatments were noted for blood gases or urine pH; however, day effects (P acid-base balance.

  20. Analysis and Optimization of Bulk DNA Sampling with Binary Scoring for Germplasm Characterization

    Science.gov (United States)

    Reyes-Valdés, M. Humberto; Santacruz-Varela, Amalio; Martínez, Octavio; Simpson, June; Hayano-Kanashiro, Corina; Cortés-Romero, Celso

    2013-01-01

    The strategy of bulk DNA sampling has been a valuable method for studying large numbers of individuals through genetic markers. The application of this strategy for discrimination among germplasm sources was analyzed through information theory, considering the case of polymorphic alleles scored binarily for their presence or absence in DNA pools. We defined the informativeness of a set of marker loci in bulks as the mutual information between genotype and population identity, composed by two terms: diversity and noise. The first term is the entropy of bulk genotypes, whereas the noise term is measured through the conditional entropy of bulk genotypes given germplasm sources. Thus, optimizing marker information implies increasing diversity and reducing noise. Simple formulas were devised to estimate marker information per allele from a set of estimated allele frequencies across populations. As an example, they allowed optimization of bulk size for SSR genotyping in maize, from allele frequencies estimated in a sample of 56 maize populations. It was found that a sample of 30 plants from a random mating population is adequate for maize germplasm SSR characterization. We analyzed the use of divided bulks to overcome the allele dilution problem in DNA pools, and concluded that samples of 30 plants divided into three bulks of 10 plants are efficient to characterize maize germplasm sources through SSR with a good control of the dilution problem. We estimated the informativeness of 30 SSR loci from the estimated allele frequencies in maize populations, and found a wide variation of marker informativeness, which positively correlated with the number of alleles per locus. PMID:24260321

  1. Analysis and optimization of bulk DNA sampling with binary scoring for germplasm characterization.

    Directory of Open Access Journals (Sweden)

    M Humberto Reyes-Valdés

    Full Text Available The strategy of bulk DNA sampling has been a valuable method for studying large numbers of individuals through genetic markers. The application of this strategy for discrimination among germplasm sources was analyzed through information theory, considering the case of polymorphic alleles scored binarily for their presence or absence in DNA pools. We defined the informativeness of a set of marker loci in bulks as the mutual information between genotype and population identity, composed by two terms: diversity and noise. The first term is the entropy of bulk genotypes, whereas the noise term is measured through the conditional entropy of bulk genotypes given germplasm sources. Thus, optimizing marker information implies increasing diversity and reducing noise. Simple formulas were devised to estimate marker information per allele from a set of estimated allele frequencies across populations. As an example, they allowed optimization of bulk size for SSR genotyping in maize, from allele frequencies estimated in a sample of 56 maize populations. It was found that a sample of 30 plants from a random mating population is adequate for maize germplasm SSR characterization. We analyzed the use of divided bulks to overcome the allele dilution problem in DNA pools, and concluded that samples of 30 plants divided into three bulks of 10 plants are efficient to characterize maize germplasm sources through SSR with a good control of the dilution problem. We estimated the informativeness of 30 SSR loci from the estimated allele frequencies in maize populations, and found a wide variation of marker informativeness, which positively correlated with the number of alleles per locus.

  2. Bulk segregant analysis by high-throughput sequencing reveals a novel xylose utilization gene from Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Jared W Wenger

    2010-05-01

    Full Text Available Fermentation of xylose is a fundamental requirement for the efficient production of ethanol from lignocellulosic biomass sources. Although they aggressively ferment hexoses, it has long been thought that native Saccharomyces cerevisiae strains cannot grow fermentatively or non-fermentatively on xylose. Population surveys have uncovered a few naturally occurring strains that are weakly xylose-positive, and some S. cerevisiae have been genetically engineered to ferment xylose, but no strain, either natural or engineered, has yet been reported to ferment xylose as efficiently as glucose. Here, we used a medium-throughput screen to identify Saccharomyces strains that can increase in optical density when xylose is presented as the sole carbon source. We identified 38 strains that have this xylose utilization phenotype, including strains of S. cerevisiae, other sensu stricto members, and hybrids between them. All the S. cerevisiae xylose-utilizing strains we identified are wine yeasts, and for those that could produce meiotic progeny, the xylose phenotype segregates as a single gene trait. We mapped this gene by Bulk Segregant Analysis (BSA using tiling microarrays and high-throughput sequencing. The gene is a putative xylitol dehydrogenase, which we name XDH1, and is located in the subtelomeric region of the right end of chromosome XV in a region not present in the S288c reference genome. We further characterized the xylose phenotype by performing gene expression microarrays and by genetically dissecting the endogenous Saccharomyces xylose pathway. We have demonstrated that natural S. cerevisiae yeasts are capable of utilizing xylose as the sole carbon source, characterized the genetic basis for this trait as well as the endogenous xylose utilization pathway, and demonstrated the feasibility of BSA using high-throughput sequencing.

  3. On quantitative analysis of interband recombination dynamics: Theory and application to bulk ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Lettieri, S. [Institute for Superconductors, Oxides and Innovative Materials, National Research Council (CNR-SPIN), U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy); Capello, V.; Santamaria, L. [Physics Department, University of Naples “Federico II,” Via Cintia I-80126 Napoli (Italy); Maddalena, P. [Institute for Superconductors, Oxides and Innovative Materials, National Research Council (CNR-SPIN), U.O.S. Napoli, Via Cintia, I-80126 Napoli (Italy); Physics Department, University of Naples “Federico II,” Via Cintia I-80126 Napoli (Italy)

    2013-12-09

    The issue of the quantitative analysis of time-resolved photoluminescence experiments is addressed by developing and describing two approaches for determination of unimolecular lifetime, bimolecular recombination coefficient, and equilibrium free-carrier concentration, based on a quite general second-order expression of the electron-hole recombination rate. Application to the case of band-edge emission of ZnO single crystals is reported, evidencing the signature of sub-nanosecond second-order recombination dynamics for optical transitions close to the interband excitation edge. The resulting findings are in good agreement with the model prediction and further confirm the presence, formerly evidenced in literature by non-optical methods, of near-surface conductive layers in ZnO crystals with sheet charge densities of about 3–5×10{sup 13} cm{sup −2}.

  4. Utilização de cera de abelhas na determinação da densidade do solo Utilization of beeswax in procedures of soil bulk density determination

    Directory of Open Access Journals (Sweden)

    E. M. B. Silva

    2003-10-01

    soil bulk density, substituting the paraffin wax used in the clod method. The experimental design was completely randomized in a factorial arrangement of 6 x 2 x 2 (six soils, two coverings, and two clod sizes, in three replicates. The physical characteristics of beeswax were similar to paraffin wax, especially regarding to the fusion point, solidification time and specific density. The values of soil bulk density with either beeswax or paraffin did not differ significantly. Thus, beeswax can substitute paraffin wax completely to seal soil clods in the determination of soil bulk density, without altering the results.

  5. One-dimensional and spherical polarization analysis of artificially confined spin-density waves in Cr/Sn multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Masayasu [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)]. E-mail: takeda.masayasu@jaea.go.jp; Nakamura, Mitsutaka [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Kakurai, Kazuhisa [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Mibu, Ko [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555 (Japan); Lelievre-Berna, Eddy [Institut Laue-Langevin, 6 rue Jules Horowitz BP 156-38042 Grenoble Cedex 9 (France)

    2007-07-15

    In Cr/Sn(0 0 1) multilayers in which monatomic Sn nonmagnetic layers are periodically embedded, spin-density waves (SDWs) are formed below the Neel temperature like that in bulk Cr. They are, however, quite different to the SDW in bulk Cr. For instance the wavelength of the SDW is defined not simply by the nesting vector of Cr, but also by the artificial periodicity introduced by the Sn layers. We performed the spherical neutron-polarization analysis of these anomalous SDW structures by using CRYOPAD (CRYOgenic Polarization Analysis Device) as well as the one-dimensional polarization analysis in order to get more detailed magnetic structural information which could not be obtained with unpolarized neutron experiments.

  6. Flow injection analysis-isotope ratio mass spectrometry for bulk carbon stable isotope analysis of alcoholic beverages.

    Science.gov (United States)

    Jochmann, Maik A; Steinmann, Dirk; Stephan, Manuel; Schmidt, Torsten C

    2009-11-25

    A new method for bulk carbon isotope ratio determination of water-soluble samples is presented that is based on flow injection analysis-isotope ratio mass spectrometry (FIA-IRMS) using an LC IsoLink interface. Advantages of the method are that (i) only very small amounts of sample are required (2-5 microL of the sample for up to 200 possible injections), (ii) it avoids complex sample preparation procedures such as needed for EA-IRMS analysis (only sample dilution and injection,) and (iii) high throughput due to short analysis times is possible (approximately 15 min for five replicates). The method was first tested and evaluated as a fast screening method with industrially produced ethanol samples, and additionally the applicability was tested by the measurement of 81 alcoholic beverages, for example, whiskey, brandy, vodka, tequila, and others. The minimal sample concentration required for precise and reproducible measurements was around 50 microL L(-1) ethanol/water (1.71 mM carbon). The limit of repeatability was determined to be r=0.49%. FIA-IRMS represents a fast screening method for beverage authenticity control. Due to this, samples can be prescreened as a decisive criterion for more detailed investigations by HPLC-IRMS or multielement GC-IRMS measurements for a verification of adulteration.

  7. Influence of soft ferromagnetic sections on the magnetic flux density profile of a large grain, bulk Y-Ba-Cu-O superconductor

    OpenAIRE

    Philippe, Matthieu; Ainslie, Mark D.; Wera, Laurent; Fagnard, Jean-François; Dennis, Anthony; Shi, Yunhua; Cardwell, David A.; Vanderheyden, Benoît; Vanderbemden, Philippe

    2015-01-01

    Bulk, high temperature superconductors have significant potential for use as powerful permanent magnets in a variety of practical applications due to their ability to trap record magnetic fields. In this paper, soft ferromagnetic sections are combined with a bulk, large grain Y-Ba-Cu-O (YBCO) high temperature superconductor to form superconductor/ferromagnet (SC/FM) hybrid structures. We study how the ferromagnetic sections influence the shape of the profile of the trapped magnetic induction ...

  8. Analysis of optimum density of forest roads in rural properties

    Directory of Open Access Journals (Sweden)

    Flávio Cipriano de Assis do Carmo

    2013-09-01

    Full Text Available This study analyzed the density of roads in rural properties in the south of the Espírito Santo and compared it with the calculation of the optimal density in forestry companies in steep areas. The work was carried out in six small rural properties based on the costs of roads of forest use, wood extraction and the costs of loss of productive area. The technical analysis included time and movement study and productivity. The economic analysis included operational costs, production costs and returns for different scenarios of productivity (180m.ha-1, 220m.ha-1and 250 m.ha-1. According to the results, all the properties have densities of road well above the optimum, which reflects the lack of criteria in the planning of the forest stands, resulting in a inadequate use of plantation area. Property 1 had the highest density of roads (373.92 m.ha-1 and the property 5 presented the lowest density (111.56 m.ha-1.

  9. Simulation of radiation dose distribution and thermal analysis for the bulk shielding of an optimized molten salt reactor

    Institute of Scientific and Technical Information of China (English)

    张志宏; 夏晓彬; 蔡军; 王建华; 李长园; 葛良全; 张庆贤

    2015-01-01

    The Chinese Academy of Science has launched a thorium-based molten-salt reactor (TMSR) research project with a mission to research and develop a fission energy system of the fourth generation. The TMSR project intends to construct a liquid fuel molten-salt reactor (TMSR-LF), which uses fluoride salt as both the fuel and coolant, and a solid fuel molten-salt reactor (TMSR-SF), which uses fluoride salt as coolant and TRISO fuel. An optimized 2 MWth TMSR-LF has been designed to solve major technological challenges in the Th-U fuel cycle. Preliminary conceptual shielding design has also been performed to develop bulk shielding. In this study, the radiation dose and temperature distribution of the shielding bulk due to the core were simulated and analyzed by performing Monte Carlo simulations and computational fluid dynamics (CFD) analysis. The MCNP calculated dose rate and neutron and gamma spectra indicate that the total dose rate due to the core at the external surface of the concrete wall was 1.91 µSv/h in the radial direction, 1.16 µSv/h above and 1.33 µSv/h below the bulk shielding. All the radiation dose rates due to the core were below the design criteria. Thermal analysis results show that the temperature at the outermost surface of the bulk shielding was 333.86 K, which was below the required limit value. The results indicate that the designed bulk shielding satisfies the radiation shielding requirements for the 2 MWth TMSR-LF.

  10. Spectrum response and analysis of 77 GHz band collective Thomson scattering diagnostic for bulk and fast ions in LHD plasmas

    DEFF Research Database (Denmark)

    Nishiura, M.; Kubo, S.; Tanaka, K.

    2014-01-01

    V for electron densities of (1–2) × 1019 m−3 and electron temperatures of 2–4 keV. The measured CTS spectrum shows an asymmetric shape at the foot of the bulk-ion region during the injection of 180 keV fast ions. This shape is explained by the fast-ion distribution in the velocity space (v‖, v⊥) based on Monte...... cyclotron heating beam. To clarify the diagnostic applicability of the gyrotron in the 77 GHz frequency band, we investigated the dependence of the probe and receiver beam trajectories in plasmas with high electron densities of (4–5) × 1019 m−3 and low electron densities of (1–2) × 1019 m−3. At high density......, a stray radiation component was observed in the CTS spectrum whereas it was negligibly small at low density. The CTS spectrum was measured and analysed after the in situ beam alignment using a beam scan. Qualitatively, the CTS spectrogram shows consistent response to ion temperatures of 1–2 ke...

  11. Urinary density measurement and analysis methods in neonatal unit care

    Directory of Open Access Journals (Sweden)

    Maria Vera Lúcia Moreira Leitão Cardoso

    2013-09-01

    Full Text Available The objective was to assess urine collection methods through cotton in contact with genitalia and urinary collector to measure urinary density in newborns. This is a quantitative intervention study carried out in a neonatal unit of Fortaleza-CE, Brazil, in 2010. The sample consisted of 61 newborns randomly chosen to compose the study group. Most neonates were full term (31/50.8% males (33/54%. Data on urinary density measurement through the methods of cotton and collector presented statistically significant differences (p<0.05. The analysis of interquartile ranges between subgroups resulted in statistical differences between urinary collector/reagent strip (1005 and cotton/reagent strip (1010, however there was no difference between urinary collector/ refractometer (1008 and cotton/ refractometer. Therefore, further research should be conducted with larger sampling using methods investigated in this study and whenever possible, comparing urine density values to laboratory tests.

  12. Analysis of the stability and density waves for traffic flow

    Institute of Scientific and Technical Information of China (English)

    薛郁

    2002-01-01

    In this paper, the optimal velocity model of traffic is extended to take into account the relative velocity. Thestability and density waves for traffic flow are investigated analytically with the perturbation method. The stabilitycriterion is derived by the linear stability analysis. It is shown that the triangular shock wave, soliton wave and kinkwave appear respectively in our model for density waves in the three regions: stable, metastable and unstable regions.These correspond to the solutions of the Burgers equation, Kortewegg-de Vries equation and modified Korteweg-de Vriesequation.The analytical results are confirmed to be in good agreement with those of numerical simulation. All theresults indicate that the interaction of a car with relative velocity can affect the stability of the traffic flow and raisecritical density.

  13. Thermodynamic analysis of Thermophotovoltaic Efficiency and Power Density Tradeoffs

    Energy Technology Data Exchange (ETDEWEB)

    P.F. Baldasara; J.E. Reynolds; G.W. Charache; D.M. DePoy; C.T. Ballinger; T. Donovan; J.M. Borrego

    2000-02-22

    This report presents an assessment of the efficiency and power density limitations of thermophotovoltaic (TPV) energy conversion systems for both ideal (radiative-limited) and practical (defect-limited) systems. Thermodynamics is integrated into the unique process physics of TPV conversion, and used to define the intrinsic tradeoff between power density and efficiency. The results of the analysis reveal that the selection of diode bandgap sets a limit on achievable efficiency well below the traditional Carnot level. In addition it is shown that filter performance dominates diode performance in any practical TPV system and determines the optimum bandgap for a given radiator temperature. It is demonstrated that for a given radiator temperature, lower bandgap diodes enable both higher efficiency and power density when spectral control limitations are included. The goal of this work is to provide a better understanding of the basic system limitations that will enable successful long-term development of TPV energy conversion technology.

  14. Rapid Finite Element Analysis of Bulk Metal Forming Process Based on Deformation Theory

    Institute of Scientific and Technical Information of China (English)

    WANG Peng; DONG Xiang-huai; FU Li-jun

    2009-01-01

    The one-step finite element method (FEM), based on plastic deformation theory, has been widely used to simulate sheet metal forming processes, but its application in bulk metal forming simulation has been seldom investigated, because of the complexity involved. Thus, a bulk metal forming process was analyzed using a rapid FEM based on deformation theory. The material was assumed to be rigid-plastic and strain-hardened. The constitutive relationship between stress and total strain was adopted, whereas the incompressible condition was enforced by penalty function. The geometrical non-linearity in large plastic deformation was taken into consideration. Furthermore, the force boundary condition was treated by a simplified equivalent approach, considering the contact history. Based on constraint variational principle, the deformation FEM was proposed. The one-step forward simulation of axisymmetric upsetting process was performed using this method. The results were compared with those obtained by the traditional incremental FEM to verify the feasibility of the proposed method.

  15. Phase analysis of aluminium modified GeSbTe bulk prepared from XRD of samples

    Science.gov (United States)

    Sandhu, Sharanjit; Singh, D.; Kumar, S.; Thangaraj, R.

    2016-05-01

    Various compositions of Aluminium modified GST as Alx(Ge2Sb2Te5)1-x x= 0, 0.15, 0.20, 0.25, 0.30 are prepared to study as a phase change material. Bulk prepared is studied with XRD scans for various phases formed. Phases other than Ge2Sb2Te5 do come in but dominated one is Ge2Sb2Te5 hexagonal phase.

  16. Today's and tomorrow's bio-based bulk chemicals from white biotechnology: a techno-economic analysis.

    Science.gov (United States)

    Hermann, B G; Patel, M

    2007-03-01

    Little information is yet available on the economic viability of the production of bio-based bulk chemicals and intermediates from white biotechnology (WB). This paper details a methodology to systematically evaluate the techno-economic prospects of present and future production routes of bio-based bulk chemicals produced with WB. Current and future technology routes are evaluated for 15 products assuming prices of fermentable sugar between 70 euro/t and 400 euro/t and crude oil prices of US $25/barrel and US $50/barrel. The results are compared to current technology routes of petrochemical equivalents. For current state-of-the-art WB processes and a crude oil price of US $25/barrel, WB-based ethanol, 1,3-propanediol, polytrimethylene terephthalate and succinic acid are economically viable. Only three WB products are economically not viable for future technology: acetic acid, ethylene and PLA. Future-technology ethylene and PLA become economically viable for a higher crude oil price (US $50/barrel). Production costs plus profits of WB products decrease by 20-50% when changing from current to future technology for a crude oil price of US $25 per barrel and across all sugar prices. Technological progress in WB can thus contribute significantly to improved economic viability of WB products. A large-scale introduction of WB-based production of economically viable bulk chemicals would therefore be desirable if the environmental impacts are smaller than those of current petrochemical production routes.

  17. Telemedicine – a scientometric and density equalizing analysis

    OpenAIRE

    Groneberg, David A.; Rahimian, Shaghayegh; Bundschuh, Matthias; Schwarzer, Mario; Gerber, Alexander; Kloft, Beatrix

    2015-01-01

    Background As a result of the various telemedicine projects in the past years a large number of studies were recently published in this field. However, a precise bibliometric analysis of telemedicine publications does not exist so far. Methods The present study was conducted to establish a data base of the existing approaches. Density-equalizing algorithms were used and data was retrieved from the Thomson Reuters database Web of Science. Results During the period from 1900 to 2006 a number of...

  18. Analysis of bulk and inorganic degradation products of stones, mortars and wall paintings by portable Raman microprobe spectroscopy.

    Science.gov (United States)

    Pérez-Alonso, M; Castro, K; Martinez-Arkarazo, I; Angulo, M; Olazabal, M A; Madariaga, J M

    2004-05-01

    This work reports the use of a portable Raman microprobe spectrometer for the analysis of bulk and decaying compounds in carbonaceous materials such as stones, mortars and wall paintings. The analysed stones include limestone, dolomite and carbonaceous sandstone, gypsum and calcium oxalate, both mono- and dihydrated, being the main inorganic degradation products detected. Mortars include bulk phases with pure gypsum, calcite and mixtures of both or with sand, soluble salts being the most important degradation products. The pigments detected in several wall paintings include Prussian blue, iron oxide red, iron oxide yellow, vermilion, carbon black and lead white. Three different decaying processes have been characterised in the mortars of the wall paintings: (a) a massive absorption of nitrates that reacted with calcium carbonate and promoted the unbinding of pigment grains, (b) the formation of black crusts in the vault of the presbytery and (c) the thermodecomposition of pigments due to a fire.

  19. Analysis of pattern density on process proximity compensation

    Science.gov (United States)

    Jung, Sunwook; Lo, Fred; Yang, Tien-Chu; Yang, Ta-Hong; Chen, Kuang-Chao; Lu, Chih-Yuan

    2007-03-01

    The challenges of ever-smaller CD (Critical Dimension) budget for advanced memory product requires tight ACLV (Across-Chip Line-width Variation) control. In addition to the lithographic MOPC (Model-based Optical Proximity Correction) for DCD (photo CD) control, the process correction for etch proximity effect can no longer be ignored. To meet on our requirement on final CD accuracy for critical layer, a set of test pattern, that represents memory array in one of our critical layers, has been generated for both photo and etch process characterizations. Through the combination of different pattern-coverage areas in the test mask and wafer map design, various local (chip-level) pattern densities of 40%~70% and global (wafer-level) pattern densities of 35%~65% were achieved for optical and etch proximity study. The key contributors to the process proximity effect were identified and voluminous data has been extracted from the memory block like patterns for statistical analysis. The photo and etch proximity effects were hence modeled as function of memory block separation, local pattern density as well as global pattern density. Finally, the respective photo and etch proximity effects through model-based proximity correction and rule-based proximity correction were applied in a multi-step flow to products.

  20. Morphometric analysis of density subpopulations of normal human platelets.

    Science.gov (United States)

    Chamberlain, K G; Froebel, M; Macpherson, J; Penington, D G

    1988-08-30

    Platelets from seven normal subjects were fractionated on continuous Percoll density gradients and low density (LD), intermediate, and high density (HD) platelets were prepared for transmission electron microscopy followed by computerised morphometric analysis. Normal ultrastructural appearance and discoid shape were preserved by incubation of the platelets in nutrient medium at 37 degrees C immediately before fixation. HD platelet sections had a larger mean cross-sectional area but a lower ratio of the major to the minor axis compared to LD platelet sections. HD platelets contained more alpha granules, dense granules and mitochondria per square micron of section area than LD platelets. The percentage of section area occupied by open canalicular system was greater in the LD platelets while the percentage area occupied by glycogen fields was over ten-fold higher in the HD platelets. The mean cross-sectional areas of individual alpha granules and dense granules increased with density while the opposite trend was found for mitochondria. It is suggested that these ultrastructural differences mainly arise during thrombopoiesis and may indicate some functional specialization among platelets.

  1. DESIGN, FABRICATION, TESTING AND MECHANICAL ANALYSIS OF BULK-MICROMACHINED FLOWMETERS

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaobao; Qian Jin; Zhang Dacheng

    2004-01-01

    Micromachined piezoresistive flowmeters with four different types of sensing structures have been designed, fabricated and tested. Piezoresistors were defined at the end of the sensors through p-diffusion, and their values were about 3.5 kΩ. Wheatstone bridge was configured with the piezoresistors in order to measure the output response. The output voltage increases with increasing flow rate of air, obeying determined relationships. The testing results show that the sensors that are designed for measuring 10L/M in full operational range have desired sensitivities. The sensor chip is manufactured with bulk-micromachining technologies, requiring a set of seven masks.

  2. Background Defect Density Reduction Using Automated Defect Inspection And Analysis

    Science.gov (United States)

    Weirauch, Steven C.

    1988-01-01

    Yield maintenance and improvement is a major area of concern in any integrated circuit manufacturing operation. A major aspect of this concern is controlling and reducing defect density. Obviously, large defect excursions must be immediately addressed in order to maintain yield levels. However, to enhance yields, the subtle defect mechanisms must be reduced or eliminated as well. In-line process control inspections are effective for detecting large variations in the defect density on a real time basis. Examples of in-line inspection strategies include after develop or after etch inspections. They are usually effective for detecting when a particular process segment has gone out of control. However, when a process is running normally, there exists a background defect density that is generally not resolved by in-line process control inspections. The inspection strategies that are frequently used to monitor the background defect density are offline inspections. Offline inspections are used to identify the magnitude and characteristics of the background defect density. These inspections sample larger areas of product wafers than the in-line inspections to allow identification of the defect generating mechanisms that normally occur in the process. They are used to construct a database over a period of time so that trends may be studied. This information enables engineering efforts to be focused on the mechanisms that have the greatest impact on device yield. Once trouble spots in the process are identified, the data base supplies the information needed to isolate and solve them. The key aspect to the entire program is to utilize a reliable data gathering mechanism coupled with a flexible information processing system. This paper describes one method of reducing the background defect density using automated wafer inspection and analysis. The tools used in this evaluation were the KLA 2020 Wafer Inspector, KLA Utility Terminal (KLAUT), and a new software package developed

  3. Bulk MgB2 superconductor with high critical current density synthesized by self-propagating high-temperature synthesis method

    Institute of Scientific and Technical Information of China (English)

    Feng Wang-Jun; Xia Tian-Dong; Liu Tian-Zuo; Zhao Wen-Jun; Wei Zhi-Qiang

    2005-01-01

    Pure MgB2 bulk samples are successfully synthesized by self-propagating high-temperature synthesis (SHS)method. The experiments show that the best preheating temperature is 250℃, the highest Jc values of the prepared MgB2 reach 1.5×106A/cm2 (10K, 0.5T) and 1.7×106A/cm2 (20K, 0T), and the MgB2 particle sizes range from 2 to 5μm. The advantages of this method are that it is simple, economical and suitable for the manufacture of bulk MgB2 materials on industrial scale.

  4. Microstructural and magnetic analysis of a superconducting foam and comparison with IG-processed bulk samples

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Ide, N.; Inoue, K.; Muralidhar, M.; Hauet, T.; Murakami, M.

    2016-03-01

    YBa2Cu3Oy (YBCO) foam samples show an open, porous foam structure, which may have benefits for many applications of high-T c superconductors. As the basic material of these foams is a pseudo-single crystalline material with the directional growth initiated by a seed crystal similar to standard melt-textured samples, the achieved texture of the YBCO is a very important parameter. We analyzed the local texture and grain orientation of the individual struts forming the foam by means of atomic force microscopy and electron backscatter diffraction (EBSD). Furthermore, the magnetic properties of a foam strut are evaluated by means of SQUID measurements, from which the flux pinning forces were determined. A scaling of the pinning forces in the temperature range between 60 K and 85 K was performed. These data and the details of the microstructure are compared to IG-processed, bulk material.

  5. Advanced finite element analysis of die wear in sheet-bulk metal forming processes

    Science.gov (United States)

    Behrens, Bernd-Arno; Bouguecha, Anas; Vucetic, Milan; Chugreev, Alexander; Rosenbusch, Daniel

    2016-10-01

    The novel sheet-bulk metal forming (SBMF) technology allows the production of solid metal components with various functional design features out of flat sheet specimens. However, due to the high working pressures arising during the forming process the efficiency of SBMF is tightly related to the tool service life, which is mainly limited by die wear. In the forming processes involving high contact pressures (e.g. SBMF) the influence of contact normal stresses on the die wear can be overestimated. In order to provide a realistic estimation of the die wear, the shear friction stress must be considered. The presented paper introduces a die wear model that intends the tangential component of contact stress and its implementation in the commercial FE code.

  6. Effect of Disorder on Bulk Sound Wave Speed : A Multiscale Spectral Analysis.

    Science.gov (United States)

    Shrivastava, Rohit; Luding, Stefan

    2016-04-01

    Disorder in the form of size (polydispersity) and mass of discrete elements/particles in a disordered media (a granular matter like soil) have numerous effects on it's sound propagation characteristics [1,2]. The influence of disorder on the sound wave speed and it's frequency filtering characteristics is the subject of investigation. The study will assist in understanding the connection between particle-scale dynamics and system-scale behavior of wave propagation which can be further used for modeling during non-destructive testing, seismic exploration of buried objects (oil, mineral, etc.) or to study the internal structure of the Earth. Studying the wave propagation characteristics through Discrete Element Models with varying polydispersity and mass of discrete elements in real-time, frequency space as well as through dispersion curves (ω (frequency) v/s k (wavenumber)) can shed light on this aspect by providing better microscopic understanding. To isolate the P-wave from shear and rotational modes, a one-dimensional system of elements/particles is used to study the effect of mass disorder on bulk sound wave speed through ensemble averaging of signals. Increasing polydispersity/disorder decreases the sound wave speed because of decrease in the number of contacts between particles [2] but, in contrast, increasing mass disorder increases the sound wave speed (in 1 D chains). Thus we conclude that a competition exists between these two kinds of disorder for their influence on the bulk sound wave speed. References [1] Brian P. Lawney and Stefan Luding. Frequency filtering in disordered granular chains. Acta Mechanica, 225(8):2385-2407, 2014. [2] O. Mouraille and S. Luding. Sound wave propagation in weakly polydisperse granular materials. Ultrasonics, 48(6-7):498 - 505, 2008. Selected Papers from ICU 2007.

  7. Effective dielectric constants and spectral density analysis of plasmonic nanocomposites

    Science.gov (United States)

    Lu, Jin You; Raza, Aikifa; Fang, Nicholas X.; Chen, Gang; Zhang, TieJun

    2016-10-01

    Cermet or ceramic-metal composite coatings promise great potentials in light harvesting, but the complicated composite structure at the nanoscale induces a design challenge to predict their optical properties. We find that the effective dielectric constants of nanocomposites predicted by finite-difference-time-domain (FDTD) simulation results match those of different classical effective medium theories in their respective validity range. However, a precise prediction of the fabricated nanocomposite properties for different filling factors is very challenging. In this work, we extract the spectral density functions in the Bergman representation from the analytical models, numerical simulations, and experimental data of plasmonic nanocomposites. The spectral density functions, which only depend on geometry of the nanocomposite material, provide a unique measure on the contribution of individual and percolated particles inside the nanocomposite. According to the spectral density analysis of measured dielectric constants, the material properties of nanocomposites fabricated by the co-sputtering approach are dominated by electromagnetic interaction among individual metallic particles. While in the case of the nanocomposites fabricated by the multilayer thin film approach, the material properties are dominated by percolated metallic particles inside the dielectric host, as indicated by our FDTD simulation results. This understanding provides new physical insight into the interaction between light and plasmonic nanocomposites.

  8. Lidar point density analysis: implications for identifying water bodies

    Science.gov (United States)

    Worstell, Bruce B.; Poppenga, Sandra; Evans, Gayla A.; Prince, Sandra

    2014-01-01

    Most airborne topographic light detection and ranging (lidar) systems operate within the near-infrared spectrum. Laser pulses from these systems frequently are absorbed by water and therefore do not generate reflected returns on water bodies in the resulting void regions within the lidar point cloud. Thus, an analysis of lidar voids has implications for identifying water bodies. Data analysis techniques to detect reduced lidar return densities were evaluated for test sites in Blackhawk County, Iowa, and Beltrami County, Minnesota, to delineate contiguous areas that have few or no lidar returns. Results from this study indicated a 5-meter radius moving window with fewer than 23 returns (28 percent of the moving window) was sufficient for delineating void regions. Techniques to provide elevation values for void regions to flatten water features and to force channel flow in the downstream direction also are presented.

  9. Quantitative trait loci detection of Edwardsiella tarda resistance in Japanese flounder Paralichthys olivaceus using bulked segregant analysis

    Science.gov (United States)

    Wang, Xiaoxia; Xu, Wenteng; Liu, Yang; Wang, Lei; Sun, Hejun; Wang, Lei; Chen, Songlin

    2016-11-01

    In recent years, Edwardsiella tarda has become one of the most deadly pathogens of Japanese flounder ( Paralichthys olivaceus), causing serious annual losses in commercial production. In contrast to the rapid advances in the aquaculture of P. olivaceus, the study of E. tarda resistance-related markers has lagged behind, hindering the development of a disease-resistant strain. Thus, a marker-trait association analysis was initiated, combining bulked segregant analysis (BSA) and quantitative trait loci (QTL) mapping. Based on 180 microsatellite loci across all chromosomes, 106 individuals from the F1333 (♀: F0768 ×♂: F0915) (Nomenclature rule: F+year+family number) were used to detect simple sequence repeats (SSRs) and QTLs associated with E. tarda resistance. After a genomic scan, three markers (Scaffold 404-21589, Scaffold 404-21594 and Scaffold 270-13812) from the same linkage group (LG)-1 exhibited a significant difference between DNA, pooled/bulked from the resistant and susceptible groups (P CIM). These six QTLs, designated qE1-6, explained 16.0%-89.5% of the phenotypic variance. Two of the QTLs, qE-2 and qE-4, were located at the 66.7 cM region, which was considered a major candidate region for E. tarda resistance. This study will provide valuable data for further investigations of E. tarda resistance genes and facilitate the selective breeding of disease-resistant Japanese flounder in the future.

  10. High Performance Liquid Chromatographic Analysis of Almotriptan Malate in Bulk and Tablets

    Directory of Open Access Journals (Sweden)

    Chandra Bala Sekaran

    2013-02-01

    Full Text Available Purpose: A simple RP-HPLC method has been developed and validated for the determination of almotriptan malate (ATM in bulk and tablets. Methods: Chromatographic separation of ATM was achieved by using a Thermo Scientific C18 column. A Mobile phase containing a mixture of methanol, water and acetic acid (4:8:0.1 v/v was pumped at the flow rate of 1 mL/min. Detection was performed at 227 nm. According to ICH guidelines, the method was validated. Results: The calibration curve was linear in the concentration range 5–60 μg/mL for the ATM with regression coefficient 0.9999. The method was precise with RSD <1.2%. Excellent recoveries of 99.60 - 100.80% proved the accuracy of the method. The limits of detection and quantification were found to be 0.025 and 0.075 μg/mL, respectively. Conclusion: The method was successfully applied for the quantification of ATM in tablets with acceptable accuracy and precision.

  11. 天祝高寒草甸土壤容重与孔隙度时空变化研究%Study on spatial-temporal changes of soil bulk density and soil porosity of alpine meadow in Tianzhu

    Institute of Scientific and Technical Information of China (English)

    路远; 张万祥; 孙榕江; 常根柱

    2009-01-01

    The soil physical poperties of 4 types of alpine meadow (Kobresia capillifoli,sedge+grass,grass+forb,Polygonum viviparum) in Tianzhu was studied. The results showed that there was no fixed variation pattern in soil bulk density and soil porosity among different types,while the variation regulation of the soil spatial structure was clear. The soil bulk density increased and soil porosity decreased along with the soil depth. The soil bulk density of semi-artificial pasture was smaller than other three plots.%选取天祝高寒草甸线叶嵩草草地(Kobresia capillifolia pasture)、莎草-禾草草地(sedge-grass pasture)、禾草-杂类草草地(grass-forb semi-artificial pasture)及珠芽蓼草地(Polygonum viviparum pasture)4块样地的土壤为研究对象,通过对其土壤的物理性状取样分析,结果表明:土壤容重与孔隙度随时间无确定的变化规律;土壤空间结构变化规律明显,均表现出土壤容重随土层深度增加而逐渐增大,土壤孔隙度随土层深度增加而逐渐减小的规律.并且禾草-杂类草半人工草地的土壤容重小于其他3个样地,说明其表层土壤孔隙度增大,通气透水性好.

  12. Movimento e inativação do metribuzin em materiais de dois solos, sob diferentes densidades aparentes Movement and inactivation of metribuzin in two soil materials with different bulk densities

    Directory of Open Access Journals (Sweden)

    L.E.F. Fontes

    1980-06-01

    Full Text Available Numa série de ensaios em laboratório e casa-de-vegetação, estudou-se a mobilidade e a inativação do herbicida metribuzin em materiais de um Latossolo e de um Podzólico representativos de duas regiões do Estado de Minas Gerais, em função de diferentes densidades aparentes. Ensaios biológicos foram utilizados para medir a inativação e a mobilidade do metribuzin nos diferentes solos e densidades. A densidade aparente alterou de forma pronunciada a quantidade de herbicida lixiviado através das colunas dos materiais dos solos estudados. Quanto maior a densidade, menor a quantidade de herbicida lixiviado. A quantidade de herbicida que permaneceu biologicamente ativo ao longo da coluna foi diretamente relacionada com a densidade, em cada solo. A mobilidade do metribuzin no material do Latossolo foi maior que no de Podzólico, em consequência de maior atividade coloidal deste.The leaching and inactivation of metribuzin were studied with materials of two mineral soilsat different bulk densities. Plastic tubing of' 7.25 cm diameter and 10 cm height were filled up with different amounts of soil to get different bulk densities. One kg/ha of a.i. of metribuzin placed on the surface are a of the column was le ached through these soil colums using 250 ml of water. The cotyledon disk bioassay method was used to detect the metribuzin leachet. The biological active metribuzin in the soil colunn at different depths, and the inativation abil ity of the soils were determined using the assay with cucumber (Cucumis sativus L. as test-plant. The increase of bulk density reduced the leaching and enhanced the biologically active metribuzin in the soil column. Metribuzin was more mobil in the Red -yellow Lato ssol and more inactivated in the Red-yellow Podzolic soils.

  13. Investigation of microstructure of bulk Ni 2MnGa alloy by means of electron backscatter diffraction analysis

    Science.gov (United States)

    Koblischka-Veneva, A.; Gachot, C.; Leibenguth, P.; Mücklich, F.

    2007-09-01

    The microstructure of bulk samples of the shape memory alloy Ni 2MnGa is evaluated by means of electron backscatter diffraction (EBSD). The crystallographic orientation of individual grains can be determined with a high spatial resolution using an automated recording of Kikuchi patterns. The obtained data are presented in form of image quality (IQ) and orientation maps, pole figures and orientation distribution functions. Local EBSD maps and pole figures reveal details about the orientation of the twin structure. The twin structure is clearly resolved within the EBSD mappings; the matrix is oriented in [1 0 0] direction and there is a 90° misorientation to the neighboring twin. Furthermore, pole figures obtained by EBSD are compared to those determined by means of X-ray texture analysis. Therefore, the EBSD measurements give information not accessible to the X-ray pole figure analysis.

  14. Study of the feasibility and precision in dose calculation with the method of bulk density assignment%容积密度分配法剂量计算可行性研究

    Institute of Scientific and Technical Information of China (English)

    秦颂兵; 周菊英; 龚唯; 吴承骏; 郭建; 陈龙; 詹蔚

    2013-01-01

    Objective To study investigate the dose accuracy that can be achieved with the method of bulk density assignment.Methods Sixteen cases of nasopharyngeal cancer patients and nineteen cases of esophageal cancer patients who accept radiotherapy in our department were selected.The planning CT images with bulk density assignment to different classes of tissues were applied to calculate the dose distributions,and then the resulting dose volume histograms (DVH) of the tumor and organs of risk were compared with the original treatment plan.The paired t-test was taken for dose comparison between two plans.Results The DVH comparison based on the planning CT and the bulk density assignment CT showed good agreements.With nasopharyngeal cancer patients,differences between the two plans about target and normal tissue were less than 1%.With esophageal cancer patients,the dose differences were less than 2%.Conclusion Preliminary results confirm that the bulk density assignment method can be applied to calculate the dose distributions.%目的 评估采用容积密度分配法进行剂量计算的可行性.方法 选取本科放疗的16例鼻咽癌和19例食管癌患者,对定位CT计划进行容积密度分配法重新制作计划,根据靶区和危及器官受量及剂量体积直方图比较新计划与原计划的剂量分布差异.两种计划的剂量比较行配对t检验.结果 采用容积密度分配法后的计划与定位CT计划相比靶区及危及器官剂量差异鼻咽癌患者均<1%、食管癌患者均<2%.结论 初步结果证实采用容积密度分配法可以进行剂量计算.

  15. 中国主要土壤类型的土壤容重传递函数研究%Pedotransfer Functions for Prediction of Soil Bulk Density for Major Types of Soils in China

    Institute of Scientific and Technical Information of China (English)

    韩光中; 王德彩; 谢贤健

    2016-01-01

    由于我国大多数土壤数据库缺失或部分缺失土壤容重数据,利用土壤其他属性来预测土壤容重具有重要意义.我国土壤类型多样,已有的土壤容重传递函数在不同土壤类型中的适用性也值得进一步探讨.本文基于我国现有的土壤数据库,对已有的两种土壤容重传递函数在不同土壤类型(土纲)中的预测精度与适用性进行评估,最后通过SPSS 进行回归分析建立我国主要土壤类型最适宜的容重传递函数.研究结果表明,已有的两种土壤容重传递函数应用于部分土壤类型时预测精度不高,但基于土壤系统分类的数据分组后建立的容重传递函数能够明显提高预测精度.新建的容重传递函数对有机土、铁铝土、潜育土、均腐土、富铁土、淋溶土、雏形土、新成土和变性土土壤容重的预测精度较高,但人为土、盐成土和干旱土土壤容重传递函数的预测精度整体偏低,在应用时需要慎重.在利用土壤容重传递函数时一定要注意研究区及适用范围.%Soil bulk density,which can be measured through several labor-intensive procedures,is often missing from most soil databases. However,it is an essential parameter in calculation in many cases and models,and it is feasible to derive soil bulk density from some other attributes of the soil. As China has a huge variety of soil types,whether the existing pedotransfer functions(PTFs)are still applicable to the various soils calls for in-depth analysis. The soil data involved in this study were cited from the Second National Soil Survey of China,from the database for the Chinese Soil Taxonomy and from other publications, covering all the major types of soils in China. The data gathered during the Second National Soil Survey were converted into the Chinese Soil Taxonomy system by means of approximate reference between the two systems using a WebGIS-based inquiry system. After screening of the data in quality and

  16. Sensitivity analysis of effective fluid and rock bulk modulus due to changes in pore pressure, temperature and saturation

    Science.gov (United States)

    Bhakta, Tuhin; Avseth, Per; Landrø, Martin

    2016-12-01

    Fluid substitution plays a vital role in time-lapse seismic modeling and interpretation. It is, therefore, very important to quantify as exactly as possible the changes in fluid bulk modulus due to changes in reservoir parameters. In this paper, we analyze the sensitivities in effective fluid bulk modulus due to changes in reservoir parameters like saturation, pore-pressure and temperature. The sensitivities are analyzed for two extreme bounds, i.e. the Voigt average and the Reuss average, for various fluid combinations (i.e. oil-water, gas-water and gas-oil). We quantify that the effects of pore-pressure and saturation changes are highest in the case of gas-water combination, while the effect of temperature is highest for oil-gas combination. Our results show that sensitivities vary with the bounds, even for same amount of changes in any reservoir parameter. In 4D rock physics studies, we often neglect the effects of pore-pressure or temperature changes assuming that those effects are negligible compare to the effect due to saturation change. Our analysis shows that pore-pressure and temperature changes can be vital and sometimes higher than the effect of saturation change. We investigate these effects on saturated rock bulk modulus. We first compute frame bulk modulus using the Modified Hashin Shtrikman (MHS) model for carbonate rocks and then perform fluid substitution using the Gassmann equation. We consider upper bound of the MHS as elastic behavior for stiffer rocks and lower bound of the MHS as elastic behavior for softer rocks. We then investigate four various combinations: stiff rock with upper bound (the Voigt bound) as effective fluid modulus, stiff rock with lower bound (Reuss bound) as effective fluid modulus, soft rock with upper bound as effective fluid modulus and soft rock with lower bound as effective fluid modulus. Our results show that the effect of any reservoir parameter change is highest for soft rock and lower bound combination and lowest

  17. Q Fever Dairy Herd Status Determination Based on Serological and Molecular Analysis of Bulk Tank Milk.

    Science.gov (United States)

    Anastácio, S; Carolino, N; Sidi-Boumedine, K; da Silva, G J

    2016-04-01

    Ruminants are recognized as the main reservoirs of Coxiella burnetii. EFSA highlighted the lack of knowledge about Q fever prevalence in many European countries. A cross-sectional study was carried out in randomly selected dairy herds (n = 109) from central Portugal to screen for C. burnetii infection and to correlate it with herd factors. Bulk tank milk (BTM) samples from cattle (n = 45) and small ruminant (n = 64) herds were tested by ELISA and PCR. The apparent seroprevalence of Q fever was estimated in 45.9% (95% CI: 36.3-55.7) being higher in small ruminants (51.6; 95% CI: 39.6-63.4) than in cattle (37.8; 95% CI: 25.1-52.4). The shedding of C. burnetii in BTM was detected in 11.9% (95% CI: 7.1-19.4) of BTM, and it was higher in cattle (20%; 95% CI: 10.9-33.8) than in sheep and mixed herds (6.3%; 95% CI: 2.5-15). A high bacterial load (≥ 3 × 10(3) bacteria/ml) was observed in 85% of PCR-positive BTM. A significant correlation was found between the bacterial load and positive samples on ELISA (P abortion (P < 0.05), whereas the shedding of C. burnetii was significantly associated with the report of infertility (P < 0.05). The results highlight that serological and molecular methods in combination are a useful tool to screen for Q fever and to clarify the herd infection status. The shedding of C. burnetii through milk is important, especially in dairy cattle, and thus, the role of milk as a potential source of infection among dairy workers should not be neglected. To our knowledge, this is the first study reporting C. burnetii infection in dairy livestock in Portugal showing that Q fever is significant in dairy herds, leading to economic losses and being a risk for public health, which highlights the need of implementation of control measures.

  18. Effects of working pressure and annealing on bulk density and nanopore structures in amorphous In-Ga-Zn-O thin-film transistors

    Science.gov (United States)

    Ide, Keisuke; Kikuchi, Mitsuho; Ota, Masato; Sasase, Masato; Hiramatsu, Hidenori; Kumomi, Hideya; Hosono, Hideo; Kamiya, Toshio

    2017-03-01

    Microstructures of amorphous In-Ga-Zn-O (a-IGZO) thin films of different densities were analyzed. Device-quality a-IGZO films were deposited under optimum conditions, e.g., the total pressure P tot = 0.55 Pa produced high film densities of ˜6.1 g/cm3, while a very high P tot = 5.0 Pa produced low film densities of 5.5 g/cm3. Both films formed uniform high-density layers in the vicinity of the glass substrate, 10-20 nm in thickness depending on P tot, while their growth mode changed to a sparse columnar structure in thicker regions. X-ray reflectivity and in situ spectroscopic ellipsometry provided different results on densification by post deposition thermal annealing; i.e., the latter has a higher sensitivity. High-Z-contrast images obtained by high-angle annular dark-field scanning transmission electron microscopy were also useful for detecting nanometer-size non uniformity even in device-quality a-IGZO films.

  19. A mechanistic analysis of density dependence in algal population dynamics

    Directory of Open Access Journals (Sweden)

    Adrian eBorlestean

    2015-04-01

    Full Text Available Population density regulation is a fundamental principle in ecology, but the specific process underlying functional expression of density dependence remains to be fully elucidated. One view contends that patterns of density dependence are largely fixed across a species irrespective of environmental conditions, whereas another is that the strength and expression of density dependence are fundamentally variable depending on the nature of exogenous or endogenous constraints acting on the population. We conducted a study investigating the expression of density dependence in Chlamydomonas spp. grown under a gradient from low to high nutrient density. We predicted that the relationship between per capita growth rate (pgr and population density would vary from concave up to concave down as nutrient density became less limiting and populations experienced weaker density regulation. Contrary to prediction, we found that the relationship between pgr and density became increasingly concave-up as nutrient levels increased. We also found that variation in pgr increased, and pgr levels reached higher maxima in nutrient-limited environments. Most likely, these results are attributable to population growth suppression in environments with high intraspecific competition due to limited nutrient resources. Our results suggest that density regulation is strongly variable depending on exogenous and endogenous processes acting on the population, implying that expression of density dependence depends extensively on local conditions. Additional experimental work should reveal the mechanisms influencing how the expression of density dependence varies across populations through space and time.

  20. Continuous Flow - Cavity RingDown Spectroscopy Using a Novel Universal Interface for High-Precision Bulk 13C Analysis

    Science.gov (United States)

    Saad, Nabil; Richman, Bruce

    2010-05-01

    We have developed the world's first optical spectroscopy-based system for bulk stable isotope analysis of 13C. The system is based on a novel universal interface, named LIAISON, capable of coupling to almost any CO2-generating sample preparation front-end ranging from an elemental analyzer to any dissolved carbon analysis module, which are of significant use in geochemical, ecological and food authentication studies. In one specific application, we have coupled LIAISON to an elemental analyzer (EA) and to a cavity ring-down spectrometer (CRDS) for 13C isotopic analysis of adulterated honey samples. Another application was developed to analyze dissolved inorganic carbon in water samples. LIAISON is suited for handling a high-throughput sample analysis process by running three different gas handling operations in parallel: Admitting combustion gas from the EA into a first gas bellows, analyzing the previous sample collected into a second gas bellows with CRDS, and flushing and purging a third gas bellows in preparation for the upcoming sample collection operation. The sample-to-sample analysis time is 10 minutes and the operation is completely automated for the whole front-end auto-sampler tray capacity, requiring no operator intervention. The CRDS data are collected, tabulated and saved into an output text file. The memory effect between the USGS L-Glutamic acid standard at natural abundance and the moderately enriched USGS L-Glutamic acid standard is excluded by the selection of the adequate number and duration of flush and purge cycles of the gas sample bags. The system's proven accuracy was cross-checked with EA-IRMS and its achieved precision was typically less than 0.2 permil, including the 13C-enriched tested samples. The LIAISON-CRDS system presented here provides a fully automated solution for 13C bulk stable isotope analysis with unprecedented ease-of-use and possible field portability and application with the availability of a compact front-end. In

  1. Effect of wavelengths and excitation density on the optical properties of P3HT: SiNWs bulk heterojunction for photovoltaic applications

    Science.gov (United States)

    Hidouri, T.; Saidi, H.; Amri, C.; Saidi, F.; Bouazizi, A.

    2016-09-01

    In this work, hybrid nano-composite based on poly (3-hexylthiophène) P3HT and silicon nanowires (SiNWs) were prepared by Ag-assisted chemical etching method (MACE) on n-type (100) Si substrate. We study the influence of the power and wavelength excitation on photoluminescence (PL) properties. We note that charge transfer between poly (3-hexylthiophène) and SiNWs is more pronounced using an excitation of 488 nm than 514 nm. This result correlates with the penetration depth found. Luminescence keys as function of excitation density proves an explication of the charge behavior in hybrid structure. A red shift of the PL peak was noted with increasing the excitation density for 488 nm and 514 nm excitation due to the confinement effect.

  2. Analysis of Triplet Exciton Loss Pathways in PTB7:PC71BM Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Kraus, Hannes; Heiber, Michael C.; Väth, Stefan; Kern, Julia; Deibel, Carsten; Sperlich, Andreas; Dyakonov, Vladimir

    2016-07-01

    A strategy for increasing the conversion efficiency of organic photovoltaics has been to increase the VOC by tuning the energy levels of donor and acceptor components. However, this opens up a new loss pathway from an interfacial charge transfer state to a triplet exciton (TE) state called electron back transfer (EBT), which is detrimental to device performance. To test this hypothesis, we study triplet formation in the high performing PTB7:PC71BM blend system and determine the impact of the morphology-optimizing additive 1,8-diiodoctane (DIO). Using photoluminescence and spin-sensitive optically detected magnetic resonance (ODMR) measurements at low temperature, we find that TEs form on PC71BM via intersystem crossing from singlet excitons and on PTB7 via EBT mechanism. For DIO blends with smaller fullerene domains, an increased density of PTB7 TEs is observed. The EBT process is found to be significant only at very low temperature. At 300 K, no triplets are detected via ODMR, and electrically detected magnetic resonance on optimized solar cells indicates that TEs are only present on the fullerenes. We conclude that in PTB7:PC71BM devices, TE formation via EBT is impacted by fullerene domain size at low temperature, but at room temperature, EBT does not represent a dominant loss pathway.

  3. Investigations on neutron-induced prompt gamma ray analysis of bulk samples.

    Science.gov (United States)

    Dokhale, P A; Csikai, J; Oláh, L

    2001-06-01

    A systematic investigation was carried out for the improvement of the prompt gamma interrogation method used for contraband detection by the pulsed fast/thermal neutron analysis (PFTNA) technique. Optimizations of source detector shielding and geometry, role of the type and dimension of the gamma detector, attenuation of neutrons and gamma rays in bulky samples were also studied. Results obtained for both the shielding materials and elemental content of cocaine simulants have been compared with the values calculated by the MCNP-4A code.

  4. COMBINATION OF DENSITY AND ENERGY MODULATION IN MICROBUNCHING ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Cheng Ying [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    Microbunching instability (MBI) has been one of the most challenging issues in the transport of high-brightness electron beams for modern recirculating or energy recovery linac machines. Recently we have developed and implemented a Vlasov solver [1] to calculate the microbunching gain for an arbitrary beamline lattice, based on the extension of existing theoretical formulation [2-4] for the microbunching amplification from an initial density perturbation to the final density modulation. For more thorough analyses, in addition to the case of (initial) density to (final) density amplification, we extend in this paper the previous formulation to more general cases, including energy to density, density to energy and energy to energy amplifications for a recirculation machine. Such semi-analytical formulae are then incorporated into our Vlasov solver, and qualitative agreement is obtained when the semi-analytical Vlasov results are compared with particle tracking simulation using ELEGANT [5].

  5. Simple and sensitive spectrophotometric methods for the analysis of mesalamine in bulk and tablet dosage forms

    Directory of Open Access Journals (Sweden)

    Bala Sekaran Chandra

    2011-01-01

    Full Text Available Three simple, sensitive, economical and reproducible spectrophotometric methods (A, B and C are described for determination of mesalamine in pure drug as well as in tablet dosage forms. Method A is based on the reduction of tungstate and/or molybdate in Folin Ciocalteu's reagent; method B describes the reaction between the diazotized drug and α-naphthol and method C is based on the reaction of the drug with vanillin, in acidic medium. Under optimum conditions, mesalamine could be quantified in the concentration ranges, 1-30, 1-15 and 2-30 µg mL-1 by method A, B and C, respectively. All the methods have been applied to the determination of mesalamine in tablet dosage forms. Results of analysis are validated statistically.

  6. Density and Structure Analysis of Molten Ni-W Alloys

    Institute of Scientific and Technical Information of China (English)

    Feng XIAO; Liang FANG

    2004-01-01

    Density of molten Ni and Ni-W alloys was measured in the temperature range of 1773~1873 K with a sessile drop method.The density of molten Ni and Ni-W alloys trends to decrease with increasing temperature. The density and molar volume of the alloys trend to increase with increasing W concentration in the alloys. The calculation result shows an ideal mixing of Ni-W alloys.

  7. Pulmonary Hypertension: Scientometric Analysis and Density-Equalizing Mapping

    Science.gov (United States)

    Götting, Michael; Schwarzer, Mario; Gerber, Alexander; Groneberg, David A.

    2017-01-01

    Pulmonary hypertension (PH) is characterized by the increase of the mean pulmonary arterial pressure in the lung circulation. Despite the large number of experimental and clinical studies conducted on pulmonary hypertension, there is no comprehensive work that analyzed the global research activity on PH so far. We retrieved the bibliometric data of the publications on pulmonary hypertension for two periods from the Web of science database. Here, we set the first investigation period from 1900 to 2007 (t1) due to the cited half life of articles and the relating difficulties to interpret the citation parameters. The second evaluation period (t2) covers the time interval from 2008 onwards including the year 2015. The data were analyzed and processed to density-equalizing maps using the NewQIS platform. A total number of 18,986 publications were identified in t1 that come from 85 countries. The US published the highest number of publications (n = 7,290), followed by the UK, Germany, Japan and France. In t2 19,676 items could be found worked out by 130 countries. The raking started just the same with the USA as most publishing nation with 7,127 publications on PH, followed by the UK and Germany. Japan fell back on 6th place, whereas China came into view on the 5th position. Analyzing the average citation rate as a parameter for research quality, Mexico reached the highest value in t1 and Ireland in t2. While, the country specific h-index underlined the leading position of the US research in both evaluation periods again. The average number of international collaboration items was expanding from none in 1978 to 530 items in 2015 with the USA as the country with the highest number of collaboration articles. The present study is the first large scale density-equalizing mapping and scientometric analysis of global PH research activity. Our data draw a sketch of the global research architecture in this field, indicating a need for specific research programs in countries with

  8. Pulmonary Hypertension: Scientometric Analysis and Density-Equalizing Mapping.

    Science.gov (United States)

    Götting, Michael; Schwarzer, Mario; Gerber, Alexander; Klingelhöfer, Doris; Groneberg, David A

    2017-01-01

    Pulmonary hypertension (PH) is characterized by the increase of the mean pulmonary arterial pressure in the lung circulation. Despite the large number of experimental and clinical studies conducted on pulmonary hypertension, there is no comprehensive work that analyzed the global research activity on PH so far. We retrieved the bibliometric data of the publications on pulmonary hypertension for two periods from the Web of science database. Here, we set the first investigation period from 1900 to 2007 (t1) due to the cited half life of articles and the relating difficulties to interpret the citation parameters. The second evaluation period (t2) covers the time interval from 2008 onwards including the year 2015. The data were analyzed and processed to density-equalizing maps using the NewQIS platform. A total number of 18,986 publications were identified in t1 that come from 85 countries. The US published the highest number of publications (n = 7,290), followed by the UK, Germany, Japan and France. In t2 19,676 items could be found worked out by 130 countries. The raking started just the same with the USA as most publishing nation with 7,127 publications on PH, followed by the UK and Germany. Japan fell back on 6th place, whereas China came into view on the 5th position. Analyzing the average citation rate as a parameter for research quality, Mexico reached the highest value in t1 and Ireland in t2. While, the country specific h-index underlined the leading position of the US research in both evaluation periods again. The average number of international collaboration items was expanding from none in 1978 to 530 items in 2015 with the USA as the country with the highest number of collaboration articles. The present study is the first large scale density-equalizing mapping and scientometric analysis of global PH research activity. Our data draw a sketch of the global research architecture in this field, indicating a need for specific research programs in countries with

  9. Geospatial Analysis of Pediatric EMS Run Density and Endotracheal Intubation

    Directory of Open Access Journals (Sweden)

    Matthew Hansen

    2016-09-01

    Full Text Available Introduction: The association between geographic factors, including transport distance, and pediatric emergency medical services (EMS run clustering on out-of-hospital pediatric endotracheal intubation is unclear. The objective of this study was to determine if endotracheal intubation procedures are more likely to occur at greater distances from the hospital and near clusters of pediatric calls. Methods: This was a retrospective observational study including all EMS runs for patients less than 18 years of age from 2008 to 2014 in a geographically large and diverse Oregon county that includes densely populated urban areas near Portland and remote rural areas. We geocoded scene addresses using the automated address locator created in the cloud-based mapping platform ArcGIS, supplemented with manual address geocoding for remaining cases. We then use the Getis-Ord Gi spatial statistic feature in ArcGIS to map statistically significant spatial clusters (hot spots of pediatric EMS runs throughout the county. We then superimposed all intubation procedures performed during the study period on maps of pediatric EMS-run hot spots, pediatric population density, fire stations, and hospitals. We also performed multivariable logistic regression to determine if distance traveled to the hospital was associated with intubation after controlling for several confounding variables. Results: We identified a total of 7,797 pediatric EMS runs during the study period and 38 endotracheal intubations. In univariate analysis we found that patients who were intubated were similar to those who were not in gender and whether or not they were transported to a children’s hospital. Intubated patients tended to be transported shorter distances and were older than non-intubated patients. Increased distance from the hospital was associated with reduced odds of intubation after controlling for age, sex, scene location, and trauma system entry status in a multivariate logistic

  10. Use of portable X-ray fluorescence instrument for bulk alloy analysis on low corroded indoor bronzes

    Energy Technology Data Exchange (ETDEWEB)

    Šatović, D., E-mail: dsatovic@alu.hr [Department of Conservation and Restoration, Academy of Fine Arts, Ilica 85, 10000 Zagreb (Croatia); Desnica, V. [Department of Conservation and Restoration, Academy of Fine Arts, Ilica 85, 10000 Zagreb (Croatia); Fazinić, S. [Laboratory for Ion Beam Interactions, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb (Croatia)

    2013-11-01

    One of the most often used non-destructive methods for elemental analysis when performing field measurements on bronze sculptures is X-ray fluorescence (XRF) analysis based on portable instrumentation. However, when performing routine in-situ XRF analysis on corroded objects obtained results are sometimes considerably influenced by the corrosion surface products. In this work the suitability of portable XRF for bulk analysis of low corroded bronzes, which were initially precisely characterized using sophisticated and reliable laboratory methods, was investigated and some improvements in measuring technique and data processing were given. Artificially corroded bronze samples were analyzed by a portable XRF instrument using the same methodology and procedures as when performing in-situ analysis on real objects. The samples were first investigated using sophisticated complementary laboratory techniques: Scanning Electron Microscopy, Proton-Induced X-ray Emission Spectroscopy and Rutherford Backscattering Spectrometry, in order to gain precise information on the formation of the corrosion product layers and in-depth elemental profile of corrosion layers for different aging parameters. It has been shown that for corrosion layers of up to ca. 25 μm a portable XRF can yield very accurate quantification results. - Highlights: • XRF quantification is very accurate for bronze corrosion layers of up to ca. 25 μm. • Corrosion layer formation on bronze described in two phases. • Corrosion layers precisely characterized using PIXE, RBS and SEM. • Corrosion approximated as CuO for layer thickness calculations via X-ray attenuations • Increasingly lighter corrosion matrix may cause SnLα radiation intensity inversion.

  11. Determining mutation density using Restriction Enzyme Sequence Comparative Analysis (RESCAN)

    Science.gov (United States)

    The average mutation density of a mutant population is a major consideration when developing resources for the efficient, cost-effective implementation of reverse genetics methods such as Targeting of Induced Local Lesions in Genomes (TILLING). Reliable estimates of mutation density can be achieved ...

  12. Geostatistical analysis of GPS trajectory data: Space-time densities

    NARCIS (Netherlands)

    Hengl, T.; van Loon, E.E.; Shamoun-Baranes, J.; Bouten, W.; Zhang, J.; Goodchild, M.F.

    2008-01-01

    Creation of density maps and estimation of home range is problematic for observations of animal movement at irregular intervals. We propose a technique to estimate space-time densities by separately modeling animal movement paths and velocities, both as continuous fields. First the length of traject

  13. Sample dependent response of a LaCl{sub 3}:Ce detector in prompt gamma neutron activation analysis of bulk hydrocarbon samples

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A., E-mail: aanaqvi@kfupm.edu.sa [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Al-Matouq, Faris A.; Khiari, F.Z. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Isab, A.A. [Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia); Khateeb-ur-Rehman,; Raashid, M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2013-08-11

    The response of a LaCl{sub 3}:Ce detector has been found to depend upon the hydrogen content of bulk samples in prompt gamma analysis using 14 MeV neutron inelastic scattering. The moderation of 14 MeV neutrons from hydrogen in the bulk sample produces thermal neutrons around the sample which ultimately excite chlorine capture gamma rays in the LaCl{sub 3}:Ce detector material. Interference of 6.11 MeV chlorine gamma rays from the detector itself with 6.13 MeV oxygen gamma rays from the bulk samples makes the intensity of the 6.13 MeV oxygen gamma ray peak relatively insensitive to variations in oxygen concentration. The strong dependence of the 1.95 MeV doublet chlorine gamma ray yield on hydrogen content of the bulk samples confirms fast neutron moderation from hydrogen in the bulk samples as a major source of production of thermal neutrons and chlorine gamma rays in the LaCl{sub 3}:Ce detector material. Despite their poor oxygen detection capabilities, these detectors have nonetheless excellent detection capabilities for hydrogen and carbon in benzene, butyl alcohol, propanol, propanic acid, and formic acid bulk samples using 14 MeV neutron inelastic scattering.

  14. Design of a new sensor for determination of the effects of tractor field usage in southern Spain: soil sinkage and alterations in the cone index and dry bulk density.

    Science.gov (United States)

    Valera, Diego L; Gil, Jesús; Agüera, Juan

    2012-10-08

    Variations in sinkage and cone index are of crucial importance when planning fieldwork, and for determining the trafficability of farm machinery. Many studies have highlighted the link between higher values of these parameters and dramatic decreases in crop yield. Variations in the dry bulk density and cone index of clayey soil in Southern Spain were measured following each of five successive passes over the same land with the three types of tractor most widely used in the area (tracked, two-wheel drive and four-wheel drive). In addition, sinkage (rut depth) of the running gear was measured using a laser microrelief profile meter. This device, which integrates three sensors, was specifically designed for these experiments, as was an electrical penetrometer to determine the cone index, and both instruments proved reliable and accurate in the field. The main goal of this study was to design, manufacture and test these new devices. The first pass caused most soil alteration when compared to successive passes for all types of tractor tested and soil conditions prevailing during the tests. (Heavier) four-wheel drive tractors were found to cause greater soil damage (sinkage, cone index and dry bulk density) than two-wheel drive and track tractors. There was no statistically significant difference between the two latter types. The greatest alterations were recorded in the top 10 cm of the soil. The results show that soil compaction should be avoided as much as possible. This can be achieved by ensuring that tractors always travel along the same tracks, especially in the wet season. At present these aspects are not considered by farmers in this area.

  15. Design of a New Sensor for Determination of the Effects of Tractor Field Usage in Southern Spain: Soil Sinkage and Alterations in the Cone Index and Dry Bulk Density

    Directory of Open Access Journals (Sweden)

    Diego L. Valera

    2012-10-01

    Full Text Available Variations in sinkage and cone index are of crucial importance when planning fieldwork, and for determining the trafficability of farm machinery. Many studies have highlighted the link between higher values of these parameters and dramatic decreases in crop yield. Variations in the dry bulk density and cone index of clayey soil in Southern Spain were measured following each of five successive passes over the same land with the three types of tractor most widely used in the area (tracked, two-wheel drive and four-wheel drive. In addition, sinkage (rut depth of the running gear was measured using a laser microrelief profile meter. This device, which integrates three sensors, was specifically designed for these experiments, as was an electrical penetrometer to determine the cone index, and both instruments proved reliable and accurate in the field. The main goal of this study was to design, manufacture and test these new devices. The first pass caused most soil alteration when compared to successive passes for all types of tractor tested and soil conditions prevailing during the tests. (Heavier four-wheel drive tractors were found to cause greater soil damage (sinkage, cone index and dry bulk density than two-wheel drive and track tractors. There was no statistically significant difference between the two latter types. The greatest alterations were recorded in the top 10 cm of the soil. The results show that soil compaction should be avoided as much as possible. This can be achieved by ensuring that tractors always travel along the same tracks, especially in the wet season. At present these aspects are not considered by farmers in this area.

  16. Numerical analysis of wet separation of particles by density differences

    CERN Document Server

    Markauskas, Darius

    2016-01-01

    Wet particle separation is widely used in mineral processing and plastic recycling to separate mixtures of particulate materials into further usable fractions due to density differences. This work presents efforts aiming to numerically analyze the wet separation of particles with different densities. In the current study the discrete element method (DEM) is used for the solid phase while the smoothed particle hydrodynamics (SPH) is used for modeling of the liquid phase. The two phases are coupled by the use of a volume averaging technique. In the current study, simulations of spherical particle separation were performed. In these simulations, a set of generated particles with two different densities is dropped into a rectangular container filled with liquid. The results of simulations with two different mixtures of particles demonstrated how separation depends on the densities of particles.

  17. Soil Bulk Density and Porosity in Greenhouse Vegetables Field under the Optimized Fertilization Treatment%优化施肥处理下设施菜地土壤容重与孔隙度的变化

    Institute of Scientific and Technical Information of China (English)

    张宝峰; 曾路生; 李俊良; 陈清

    2013-01-01

    Soil bulk density and porosity influence the bioavailability of soil nutrient and crop growth, and are closely related to the cultivation, fertilization, irrigation and other agricultural management measures. In order to research soil environmental quality and explore the optimal fertilization mode under Greenhouse field conditions, soil bulk density, porosity and soil respiration intensity were studied under the optimized fertilization conditions, with the soil of no chemical fertilizer and manure for control in Shouguang Greenhouse vegetables field planting tomato, and the results showed that, compared with the control, the optimized fertilization treatments improved the soil bulk density and porosity conditions in a certain extent. Such measures reduced the soil bulk density by 3.73%to 14.93%and increased the soil total porosity by 4.18%to 15.79%. In the meantime, the average capillary porosity and the non capillary porosity increased by 8.07%and 8.94%, respectively. Soil respiration intensity enhanced by 23.4%to 34.6%in the root zone and by 9.6%to 106.9%in the non root zone compared with the control. Among them, the treatment with 8 t/hm2 of manure and 4 t/hm2 of straw blending broadcast, and topdressing 150 kg/hm2 of nitrogen in the growth period got the most obvious effect and should be recommended to apply in the production practice. The results also showed that the average soil respiration intensity in root zone was 62.91 mg/(kg·d) with about 1.8 times of 34.45 mg/(kg·d) in the non-root zone. Soil respiration intensity was parabolic relationship to soil bulk density and soil total porosity. When the soil bulk density was about 1.25 g/cm3 and total porosity was about 53%, the soil would have higher respiration intensity.%土壤容重与孔隙度影响土壤养分的有效性及作物生长,与耕作、施肥、灌溉等农业管理措施密切相关。为了研究设施农业条件下土壤环境质量的变化,探索较优施肥

  18. MICROSTRUCTURE DEPENDENCE OF DIRECT-CURRENT ELECTRODEPOSITED BULK Cu WITH PREFERENTIALLY ORIENTED NANOTWINS ON THE CURRENT DENSITIES%电流密度对直流电解沉积纳米孪晶Cu微观结构的影响

    Institute of Scientific and Technical Information of China (English)

    金帅; 潘庆松; 卢磊

    2013-01-01

    采用直流电解沉积技术,制备出具有高密度择优取向的纳米孪晶结构块体Cu样品.样品由微米级柱状晶粒构成,晶粒内有高密度的平行于生长基面的共格孪晶界面.研究发现,电流密度对于纳米孪晶Cu的晶粒尺寸有明显影响,但对其织构和孪晶片层厚度影响不大.当电流密度从10 mA/cm2增加到30 mA/cm2,纳米孪晶Cu的平均晶粒尺寸从10.1 μm减小到4.2 μm,孪晶片层厚度为30-50 nm.其原因是随电流密度的增加,阴极的过电位增大,从而使晶粒细化.%Bulk Cu with preferentially oriented nanoscale twins was synthesized by means of direct-current electrodepositon.The nanotwinned Cu sample is composed of columnar grains with high density nanoscale coherent twin boundaries,most of which are parallel to the growth plane.It was found that the current densities play an important role on the grain size of the nanotwinned Cu samples,however,a non-obvious effect was found on the twin lamellar thickness.With increasing the current densities from 10 mA/cm2 to 30 mA/cm2,the average grain size of the bulk nanotwinned Cu samples was decreased from about 10.1 μm to 4.2 μm.While the twin lamellar thickness was unchanged obviously and in the range of 30-50 nm.This is because that with the increase of current density,the overpotential of cathode increases and the grain refinement occurs.

  19. Ab-initio investigations of the electronic properties of bulk wurtzite Beryllia and its derived nanofilms

    KAUST Repository

    Goumri-Said, Souraya

    2010-08-01

    In this Letter we investigate the electronic properties of the bulk and the nanofilm BeO in wurtzite structure. We performed a first-principles pseudo-potential method within the generalized gradient approximation. We will give more importance to the changes in band structure and density of states between the bulk structure and its derived nanofilms. The bonding characterization will be investigated via the analysis Mulliken population and charge density contours. It is found that the nanofilm retains the same properties as its bulk structure with slight changes in electronic properties and band structure which may offer some unusual transport properties. © 2010 Elsevier B.V. All rights reserved.

  20. Analysis of the Influence of Element's Entropy on the Bulk Metallic Glass (BMG) Entropy, Complexity, and Strength

    Science.gov (United States)

    Namazi, Hamidreza; Akrami, Amin; Haghighi, Reza; Delaviz, Ali; Kulish, Vladimir V.

    2017-02-01

    Bulk metallic glasses (BMGs) are disordered compounds without a long-range crystalline order. In this paper, we study the effect of an element's standard entropy on the BMG's entropy and complexity for four elements. In order to do this, we simulate the BMG structures first. Then we compute the entropy and fractal dimension of the resulting structures as measures of disorder and complexity, respectively. We verify our predictions via experiments. In doing so, we substitute the elements in separate experiments and compute the fractal dimension of the obtained BMG pattern. The results of our investigations show that there is a relation between the variations of elements' entropies and the variations of BMGs' entropy and fractality. On the other hand, measurement of the compressive strength for the obtained BMGs from experiments shows that by increasing the entropy and fractal dimension, BMG's compressive strength increases. The adaptive capability observed in this method could potentially be harnessed for targeted BMG production, depending on the specific design goal. The method discussed here is not only useful for analysis of BMG structures, but it can be applied to other structures.

  1. Strategy for the mapping of interactive genes using bulked segregant analysis method and Mapmaker/Exp software

    Institute of Scientific and Technical Information of China (English)

    WU Weiren; HUANG Biguang

    2006-01-01

    A qualitative trait is usually controlled by a single gene, but it may be sometimes controlled by two or even more genes. This phenomenon is called gene interaction. Rapidly searching for linked molecular markers via bulked segregant analysis (BSA)and then constructing regional linkage map with Mapmaker/Exp has become a common approach to mapping single major genes. However, methods and computer programs developed for mapping single major genes cannot be simply applied to interactive genes because the genetic patterns of gene interactions are quite different from that of single-gene inheritance. Up to now, experimental methods for quickly screening molecular markers linked to interactive genes and statistical methods and corresponding computer softwares for simultaneously analyzing the linkage relationships of multiple molecular markers to an interactive gene have not been available. To solve this problem, in this paper, we propose a strategy for mapping interactive genes using BSA and Mapmaker/Exp. We demonstrate that Mapmaker/Exp' strategy using F2 generation (in a few cases, F3 generation is also needed). As BSA and Mapmaker/Exp have been broadly used in gene mapping studies and are well known by many researchers, the strategies proposed in this paper will be useful for practical researches.

  2. Effects of thermal treatment and depth profiling analysis of solution processed bulk-heterojunction organic photovoltaic cells.

    Science.gov (United States)

    Mbule, Pontsho S; Swart, Hendrik C; Ntwaeaborwa, Odireleng M

    2014-12-15

    We report the use of solution processed zinc oxide (ZnO) nanoparticles as a buffer layer inserted between the top metal electrode and the photo-active layer in bulk-heterojunction (BHJ) organic solar cell (OSC) devices. The photovoltaic properties were compared for devices annealed before (Device A) or after (Device B) the deposition of the Al top electrode. The post-annealing treatment was shown to improve the power conversion efficiency up to 2.93% and the fill factor (FF) up to 63% under AM1.5 (100mW/cm(2)) illumination. We performed the depth profile/interface analysis and elemental mapping using the time-of-flight secondary ion mass spectrometry (TOF-SIMS). Signals arising from (27)Al, (16)O, (12)C, (32)S, (64)Zn, (28)Si, (120)Sn and (115)In give an indication of successive deposition of Al, ZnO, P3HT:PCBM and PEDOT:PSS layers on ITO coated glass substrates. Furthermore, we discuss the surface imaging and visualize the chemical information on the surface of the devices.

  3. A combined surface and bulk TCAD damage model for the analysis of radiation detectors operating at HL-LHC fluences

    Science.gov (United States)

    Morozzi, A.; Passeri, D.; Moscatelli, F.; Dalla Betta, G.-F.; Bilei, G. M.

    2016-12-01

    In this work we present the development and the application of a new TCAD modelling scheme to simulate the effects of radiation damage on silicon radiation detectors at the very high fluence levels expected at High Luminosity LHC (up to 2 × 1016 1MeV n/cm2). In particular, we propose a combined approach for the analysis of the surface effects (oxide charge build-up and interface trap states introduction) as well as bulk effects (deep level traps and/or recombination centers introduction). Experimental measurements have been carried out aiming at: i) extraction from simple test structures of relevant parameters to be included within the TCAD model and ii) validation of the new modelling scheme through comparison with measurements of different test structures (e.g. different technologies) before and after irradiation. The good agreements between experimental measurements and simulation findings foster the suitability of the TCAD modelling approach as a predictive tool for investigating the radiation detector behavior at different fluences and operating conditions. This would allow the design and optimization of innovative 3D and planar silicon detectors for future HL-LHC High Energy Physics experiments.

  4. Effect of soil bulk density on root morphology and biomass of vetiver grass seedlings%土壤容重对野生香根草幼苗根系形态及其生物量的影响

    Institute of Scientific and Technical Information of China (English)

    刘晚苟; 李良贤; 谢海容; 何泳怡; 刘金祥

    2015-01-01

    香根草因其具有发达的根系而被许多国家用于水土保持,但紧实土壤影响根系的生长,而土壤容重与土壤紧实度密切相关。为了掌握粤西野生香根草对紧实土壤的适应状况,用人工土柱研究了容重分别为1.20 g/cm3(D1.20)、1.35 g/cm3(D1.35)和1.58 g/cm3(D1.58)的土壤对其根系形态和生物量的影响。结果表明:1)随容重增大,根系和地上部生物量下降,根冠比降低,植株的根表面积、根长密度和根体积密度减小,而平均根直径增大。2)容重影响根系的空间分布,D1.20和 D1.35处理的根系在上、下层分布较多,中间层分布少,表明粤西野生香根草具有深根型特性;高容重阻止根向下延伸,D1.58处理的根系主要分布0~6 cm 的土层内。3)D1.20和 D1.35土壤的平均根直径随土层加深减小,而 D1.58的则增加。本实验结果说明粤西野生香根草能耐较紧实(D1.35)的土壤,高紧实土壤(D1.58)虽然限制其生长,但对表土层根系的分布影响小。并就容重对粤西野生香根草固土护坡的影响进行了讨论。%Vetiver grass (Vetiveria zizanioides )has an extensive root system and is consequently used world-wide for water and soil conservation.However,soil compaction resulting in high soil bulk density negatively influences root growth.In order to understand the adaptation of vetiver grass to soil compaction,the effects of soil of different bulk density,1.20 g/cm3 (D1 .20 ),1.35 g/cm3 (D1 .35 )and 1.58 g/cm3 (D1 .58 ),on the root mor-phology and biomass of vetiver seedlings were investigated using soil columns.The results showed that shoot and root dry weight,root:shoot ratio,root surface area,root length density and root volume density decreased with increasing bulk density,but that average root diameter increased.High bulk density influenced the spatial distribution of roots;more roots grew in

  5. Thermal Analysis of Low Layer Density Multilayer Insulation Test Results

    Science.gov (United States)

    Johnson, Wesley L.

    2011-01-01

    Investigation of the thermal performance of low layer density multilayer insulations is important for designing long-duration space exploration missions involving the storage of cryogenic propellants. Theoretical calculations show an analytical optimal layer density, as widely reported in the literature. However, the appropriate test data by which to evaluate these calculations have been only recently obtained. As part of a recent research project, NASA procured several multilayer insulation test coupons for calorimeter testing. These coupons were configured to allow for the layer density to be varied from 0.5 to 2.6 layer/mm. The coupon testing was completed using the cylindrical Cryostat-l00 apparatus by the Cryogenics Test Laboratory at Kennedy Space Center. The results show the properties of the insulation as a function of layer density for multiple points. Overlaying these new results with data from the literature reveals a minimum layer density; however, the value is higher than predicted. Additionally, the data show that the transition region between high vacuum and no vacuum is dependent on the spacing of the reflective layers. Historically this spacing has not been taken into account as thermal performance was calculated as a function of pressure and temperature only; however the recent testing shows that the data is dependent on the Knudsen number which takes into account pressure, temperature, and layer spacing. These results aid in the understanding of the performance parameters of MLI and help to complete the body of literature on the topic.

  6. Comparative analysis of human and bovine teeth: radiographic density

    Directory of Open Access Journals (Sweden)

    Jefferson Luis Oshiro Tanaka

    2008-12-01

    Full Text Available Since bovine teeth have been used as substitutes for human teeth in in vitro dental studies, the aim of this study was to compare the radiographic density of bovine teeth with that of human teeth to evaluate their usability for radiographic studies. Thirty bovine and twenty human teeth were cut transversally in 1 millimeter-thick slices. The slices were X-rayed using a digital radiographic system and an intraoral X-ray machine at 65 kVp and 7 mA. The exposure time (0.08 s and the target-sensor distance (40 cm were standardized for all the radiographs. The radiographic densities of the enamel, coronal dentin and radicular dentin of each slice were obtained separately using the "histogram" tool of Adobe Photoshop 7.0 software. The mean radiographic densities of the enamel, coronal dentin and radicular dentin were calculated by the arithmetic mean of the slices of each tooth. One-way ANOVA demonstrated statistically significant differences for the densities of bovine and human enamel (p 0.05. Based on the results, the authors concluded that: a the radiographic density of bovine enamel is significantly higher than that of human enamel; b the radiodensity of bovine coronal dentin is statistically lower than the radiodensity of human coronal dentin; bovine radicular dentin is also less radiodense than human radicular dentin, although this difference was not statistically significant; c bovine teeth should be used with care in radiographic in vitro studies.

  7. Minimum Entropy Density Method for the Time Series Analysis

    CERN Document Server

    Lee, J W; Moon, H T; Park, J B; Yang, J S; Jo, Hang-Hyun; Lee, Jeong Won; Moon, Hie-Tae; Park, Joongwoo Brian; Yang, Jae-Suk

    2006-01-01

    The entropy density is an intuitive and powerful concept to study the complicated nonlinear processes derived from physical systems. We develop the minimum entropy density method (MEDM) to detect the most correlated time interval of a given time series and define the effective delay of information (EDI) as the correlation length that minimizes the entropy density in relation to the velocity of information flow. The MEDM is applied to the financial time series of Standard and Poor's 500 (S&P500) index from February 1983 to April 2006. It is found that EDI of S&P500 index has decreased for the last twenty years, which suggests that the efficiency of the U.S. market dynamics became close to the efficient market hypothesis.

  8. X-ray computerized tomography analysis and density estimation using a sediment core from the Challenger Mound area in the Porcupine Seabight, off Western Ireland

    Science.gov (United States)

    Tanaka, Akiko; Nakano, Tsukasa; Ikehara, Ken

    2011-02-01

    X-ray computerized tomography (CT) analysis was used to image a half-round core sample of 50 cm long recovered from near Challenger Mound in the Porcupine Seabight, off western Ireland during the Integrated Ocean Drilling Program Expedition 307. This allowed three-dimensional examination of complex shapes of pebbles and ice-rafted debris in sedimentary sequences. X-ray CT analysis was also used for the determination of physical properties; a comparison between bulk density by the mass-volume method and estimated density based on linear attenuation coefficients of X-ray CT images provides insight into a spatially detailed and precise map of density variation in samples through the distribution of CT numbers.

  9. Lee-Yang zeros analysis of finite density lattice QCD

    CERN Document Server

    Crompton, P

    2001-01-01

    coefficients from different ensembles (through the ratio of the normalisations) we are thus able to alleviate the bias in our sampling. We then further develop this method for SU(3) with static quarks by generating a range of canonical ensembles which we combine with our new re-weighting approach. From our SU(2) measurements we establish the existence of a diquark superfluid at high densities and low temperatures. We also determine the position and order of the associated symmetry breaking transitions in the mass - chemical potential plane. From our measurements of static SU(3) we establish that the finite density transition at intermediate coupling is a first order percolation transition. Having addressed the pathologies of the re-weighting method in two nonabelian gauge field theories which are simpler to evaluate numerically, in future work SU(3) QCD can be evaluated at finite density. Recent results from four-fermion interaction models have suggested that new exotic phases form at finite baryon density wh...

  10. Asymptotic Analysis of Invariant Density of Randomly Perturbed Dynamical Systems

    OpenAIRE

    Mikami, Toshio

    1990-01-01

    The invariant density of diffusion processes which are small random perturbations of dynamical systems can be expanded in W.K.B. type, as the random effect disappears, in the set in which the Freidlin-Wentzell quasipotential $V(\\cdot)$ is of $C^\\infty$-class and each coefficient which appears in the expansion is of $C^\\infty$-class.

  11. MEASUREMENTS FOR TRAPPED FLUX DENSITY OF HIGH TEMPERATURE SUPERCONDUCTOR BULKS%块状高温超导体俘获磁通密度实验测试方法

    Institute of Scientific and Technical Information of China (English)

    徐克西; 郑明辉; 刘宜平; 焦玉磊; 肖玲

    2015-01-01

    块状单畴高温超导体的重要特性参数之一“俘获磁通密度”决定了单畴超导体能够冻结住的最大磁通俘获场,实际用户在设计装置时必须了解这些参数.然而,这些数值强烈地依赖于测试方法.随着国内块状单畴超导体的研究、生产、应用的不断发展,市场规模的不断扩大以及国际贸易的开展,迫切需要建立一个与国际接轨的测试标准,统一材料提供方与用户之间对单畴块材性能的表征过程.经国家标准化管理委员会批准,2013年全国超导标准化技术委员会将IEC 61788-9国际标准《SUPERCONDUCTIVITY-Measurements for bulk high temperature superconductors-Trapped flux density of large grain bulk oxide superconductors》(《超导电性:块状高温超导体的测量—大晶粒氧化物超导体的俘获磁通密度》)转化为国家标准,本文主要介绍有关“标准”的转化实施过程.

  12. Failure Analysis of Wind Turbines by Probability Density Evolution Method

    DEFF Research Database (Denmark)

    Sichani, Mahdi Teimouri; Nielsen, Søren R.K.; Liu, W.F.

    2013-01-01

    The aim of this study is to present an efficient and accurate method for estimation of the failure probability of wind turbine structures which work under turbulent wind load. The classical method for this is to fit one of the extreme value probability distribution functions to the extracted maxima....... This is not practical due to its excessive computational load. This problem can alternatively be tackled if the evolution of the probability density function (PDF) of the response process can be realized. The evolutionary PDF can then be integrated on the boundaries of the problem. For this reason we propose to use...... the Probability Density Evolution Method (PDEM). PDEM can alternatively be used to obtain the distribution of the extreme values of the response process by simulation. This approach requires less computational effort than integrating the evolution of the PDF; but may be less accurate. In this paper we present...

  13. Courant-Snyder invariant density screening method for emittance analysis

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-Lei; TANG Jing-Yu; JING Han-Tao

    2011-01-01

    Emittance is an important characteristic of describing charged particle beams.In hadron accelerators,we often meet irregular beam distributions that are not appropriately described by a single rms emittance or 95% emittance or total emittance.In this paper,it is pointed out that in many cases a beam halo should be described with very different Courant-Snyder parameters from the ones used for the beam core.A new method - the Courant-Snyder invariant density screening method - is introduced for analyzing emittance data clearly and accurately.The method treats the emittance data from both measurements and numerical simulations.The method uses the statistical distribution of the beam around each particle in phase space to mark its local density parameter,and then uses the density distribution to calculate the beam parameters such as the Courant-Snyder parameters and emittance for different beam boundary definitions.The method has been used in the calculations for.beams from different sources,and shows its advantages over other methods.An application code based on the method including the graphic interface has also been designed.

  14. Crystallization of High Bulk Density Nitroguanidine

    Science.gov (United States)

    2011-06-01

    microscope after obtaining solid crystals , which were filtered and washed using acetone. For measuring dissolved NQ concentration in the RC-1, a Mettler...known volume of clear supernatant solution was dried on a hot plate at 100°C and the weight of solid crystals was measured from which the solubility

  15. Interdigitated Electrodes and Anisotropic Diffraction Analysis of Phase And/or Lossy Gratings for Bulk and Integrated Applications.

    Science.gov (United States)

    Glytsis, Elias Nikolaos

    1987-09-01

    Integrated optics is the primary area of application of the results of this thesis. Research and development of integrated optical circuits have been proceeding rapidly in recent years toward practical devices such acoustooptic spectrum analyzers, analog-to-digital converters, ultrafast logic gates, correlators, and multichannel data processors. These projects, however, have underscored the lack of fundamental knowledge regarding waveguide devices in anisotropic materials such as lithium niobate. Research into the basic physical modeling of these devices is the scope of this thesis. The main topics of this thesis are issues concerning the design and function of periodic interdigitated-electrode devices. At first, the electric field problem was solved taking into account the anisotropic properties of the substrate, the finite thickness of the electrodes, and the buffer layer between the electrodes and the substrate. The inclusion of the buffer layer is important for electrooptic applications since it is needed for the isolation of the optical field from the electrode metal. The bulk diffraction of plane waves by phase/amplitude anisotropic single or cascaded gratings with uniaxial anisotropic external regions has been analyzed. The various Bragg conditions have been classified and quantified. The diffraction of guided-waves by interdigitated-electrode induced phase gratings in uniaxial anisotropic waveguides has been treated. The electrostatic and grating diffraction analysis has been validated using available experimental data. The analysis is applicable to uniaxial anisotropic waveguides with the optic axis lying either in or perpendicular to the electrode surface. It applies to single-mode waveguides and to waveguides with negligible intermodal coupling. Finally, a new technique of designing antireflection coatings and gratings on lossy substrates has been developed in this thesis. The method employs high spatial-frequency surface-relief rectangular

  16. Analysis of maize ( Zea mays ) kernel density and volume using microcomputed tomography and single-kernel near-infrared spectroscopy.

    Science.gov (United States)

    Gustin, Jeffery L; Jackson, Sean; Williams, Chekeria; Patel, Anokhee; Armstrong, Paul; Peter, Gary F; Settles, A Mark

    2013-11-20

    Maize kernel density affects milling quality of the grain. Kernel density of bulk samples can be predicted by near-infrared reflectance (NIR) spectroscopy, but no accurate method to measure individual kernel density has been reported. This study demonstrates that individual kernel density and volume are accurately measured using X-ray microcomputed tomography (μCT). Kernel density was significantly correlated with kernel volume, air space within the kernel, and protein content. Embryo density and volume did not influence overall kernel density. Partial least-squares (PLS) regression of μCT traits with single-kernel NIR spectra gave stable predictive models for kernel density (R(2) = 0.78, SEP = 0.034 g/cm(3)) and volume (R(2) = 0.86, SEP = 2.88 cm(3)). Density and volume predictions were accurate for data collected over 10 months based on kernel weights calculated from predicted density and volume (R(2) = 0.83, SEP = 24.78 mg). Kernel density was significantly correlated with bulk test weight (r = 0.80), suggesting that selection of dense kernels can translate to improved agronomic performance.

  17. Multifractal analysis of high resolution solar wind proton density measurements

    Science.gov (United States)

    Sorriso-Valvo, Luca; Carbone, Francesco; Leonardis, Ersilia; Chen, Christopher H. K.; Šafránková, Jana; Němeček, Zdenek

    2017-03-01

    The solar wind is a highly turbulent medium, with a high level of field fluctuations throughout a broad range of scales. These include an inertial range where a turbulent cascade is assumed to be active. The solar wind cascade shows intermittency, which however may depend on the wind conditions. Recent observations have shown that ion-scale magnetic turbulence is almost self-similar, rather than intermittent. A similar result was observed for the high resolution measurements of proton density provided by the spacecraft Spektr-R. Intermittency may be interpreted as the result of the multifractal properties of the turbulent cascade. In this perspective, this paper is devoted to the description of the multifractal properties of the high resolution density measurements. In particular, we have used the standard coarse-graining technique to evaluate the generalized dimensions Dq , and from these the multifractal spectrum f (α) , in two ranges of scale. A fit with the p-model for intermittency provided a quantitative measure of multifractality. Such indicator was then compared with alternative measures: the width of the multifractal spectrum, the peak of the kurtosis, and its scaling exponent. The results indicate that the small-scale fluctuations are multifractal, and suggest that different measures of intermittency are required to fully understand the small scale cascade.

  18. Analysis of the Panamax bulk carrier charter market 1989-1994 in relation to the design characteristics

    NARCIS (Netherlands)

    Wijnolst, N.; Bartelds, M.

    1995-01-01

    Panamax bulk carriers form the largest homogeneous shiptype-group in the world fleet. The H. Clarkson database contained in 1994, 834 of these ships, in a dead-weight range of 50.000-76.000 tons. The dimensions of panamax vessels are restricted by the dimensions of the locks of the Panama Canal, esp

  19. Origin, Bulk Chemical Composition and Physical Structure of the Galilean Satellites of Jupiter: A Post-Galileo Analysis

    Science.gov (United States)

    Prentice, A. J. R.

    1999-01-01

    The origin of Jupiter and the Galilean satellite system is examined in the light of the new data that has been obtained by the NASA Galileo Project. In particular, special attention is given to a theory of satellite origin which was put forward at the start of the Galileo Mission and on the basis of which several predictions have now been proven successful. These predictions concern the chemical composition of Jupiter's atmosphere and the physical structure of the satellites. According to the proposed theory of satellite origin, each of the Galilean satellites formed by chemical condensation and gravitational accumulation of solid grains within a concentric family of orbiting gas rings. These rings were cast off equatorially by the rotating proto-Jovian cloud (PJC which contracted gravitationally to form Jupiter some 4 1/2 billion years ago. The PJC formed from the gas and grains left over from the gas ring that had been shed at Jupiter's orbit by the contracting proto-solar cloud (PSC Supersonic turbulent convection provides the means for shedding discrete gas rings. The temperatures T (sub n) of the system of gas rings shed by the PSC and PJC vary with their respective mean orbital radii R (sub n) (n = 0, 1,2,...) according as T (sub n) proportional to R (sub n) (exp -0.9). If the planet Mercury condenses at 1640 K, so accounting for the high density of that planet via a process of chemical fractionation between iron and silicates, then T (sub n) at Jupiter's orbit is 158 K. Only 35% of the water vapour condenses out. Thus fractionation between rock and ice, together with an enhancement in the abundance of solids relative to gas which takes place through gravitational sedimentation of solids onto the mean orbit of the gas ring, ensures nearly equal proportions of rock and ice in each of Ganymede and Callisto. Io and Europa condense above the H20 ice point and consist solely of hydrated rock (h-rock). The Ganymedan condensate consists of h-rock and H20 ice. For

  20. The Incredible Bulk

    CERN Document Server

    Fukushima, Keita; Kumar, Jason; Sandick, Pearl; Yamamoto, Takahiro

    2014-01-01

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have ...

  1. Crowd Analysis by Using Optical Flow and Density Based Clustering

    DEFF Research Database (Denmark)

    Santoro, Francesco; Pedro, Sergio; Tan, Zheng-Hua;

    2010-01-01

    , it is applied a crowd tracker in every frame, allowing us to detect and track the crowds. Our system gives the output as a graphic overlay, i.e it adds arrows and colors to the original frame sequence, in order to identify crowds and their movements. For the evaluation, we check when our system detect certains......In this paper, we present a system to detect and track crowds in a video sequence captured by a camera. In a first step, we compute optical flows by means of pyramidal Lucas-Kanade feature tracking. Afterwards, a density based clustering is used to group similar vectors. In the last step...... events on the crowds, such as merging, splitting and collision....

  2. Periodic Density Functional Theory Solver using Multiresolution Analysis with MADNESS

    Science.gov (United States)

    Harrison, Robert; Thornton, William

    2011-03-01

    We describe the first implementation of the all-electron Kohn-Sham density functional periodic solver (DFT) using multi-wavelets and fast integral equations using MADNESS (multiresolution adaptive numerical environment for scientific simulation; http://code.google.com/p/m-a-d-n-e-s-s). The multiresolution nature of a multi-wavelet basis allows for fast computation with guaranteed precision. By reformulating the Kohn-Sham eigenvalue equation into the Lippmann-Schwinger equation, we can avoid using the derivative operator which allows better control of overall precision for the all-electron problem. Other highlights include the development of periodic integral operators with low-rank separation, an adaptable model potential for nuclear potential, and an implementation for Hartree Fock exchange. This work was supported by NSF project OCI-0904972 and made use of resources at the Center for Computational Sciences at Oak Ridge National Laboratory under contract DE-AC05-00OR22725.

  3. Density Functional Theory using Multiresolution Analysis with MADNESS

    Science.gov (United States)

    Thornton, Scott; Harrison, Robert

    2012-02-01

    We describe the first implementation of the all-electron Kohn-Sham density functional periodic solver (DFT) using multi-wavelets and fast integral equations using MADNESS (multiresolution adaptive numerical environment for scientific simulation; http://code.google.com/p/m-a-d-n-e-s-s). The multiresolution nature of a multi-wavelet basis allows for fast computation with guaranteed precision. By reformulating the Kohn-Sham eigenvalue equation into the Lippmann-Schwinger equation, we can avoid using the derivative operator which allows better control of overall precision for the all-electron problem. Other highlights include the development of periodic integral operators with low-rank separation, an adaptable model potential for the nuclear potential, and an implementation for Hartree-Fock exchange.

  4. The impact of agriculture terraces on soil organic matter, aggregate stability, water repellency and bulk density. A study in abandoned and active farms in the Sierra de Enguera, Eastern Spain.

    Science.gov (United States)

    Cerdà, Artemi; Burguet, Maria; Keesstra, Saskia; Prosdocimi, Massimo; Di Prima, Simone; Brevik, Erik; Novara, Agata; Jordan, Antonio; Tarolli, Paolo

    2016-04-01

    Soil erosion, land degradation, lack of organic matter, erodible soils, rock outcrops… are a consequence of the human abuse and misuse of the soil resources. And this is a worldwide environmental issue (Novara et al., 2011; Vanlauwe et al., 2015; Musinguzi et al., 2015; Pereira et al., 2015; Mwagno et al., 2016). Agriculture terraces are a strategy to reduce the soil erosion, improve the soil fertility and allow the ploughing (Cerdà et al., 2010; Li et al., 2014). Although this idea is well accepted there are few scientific evidences that demonstrate that soils in the terraced areas are more stable, fertile and sustainable that the soil in non terraced areas. In fact, the ploughing in comparison to the abandoned or not ploughed land results in the soil degradation (Lieskovský and Kenderessy, 2014; Gao et al., 2015; Parras-Alcántara et al., 2014). This is mainly due to the lack of vegetation that increase the surface runoff (Cerdà et al., 1998; Keesstra et al., 2007). And why is necessary to develop also in terraced landscapes soil erosion control strategies (Mekonnen et al., 2015a; Mekonnen et al., 2015b; Prosdocimi et al., 2016). Our objective was to assess the soil organic matter content (Walkley and Black, 1934), the soil bulk density (ring method), the aggregate stabilility (drop impact) and the water repellency (Water Drop Penetration Time test) in four study sites in the Sierra de Enguera. Two sites were terraced: one abandoned 40 years before the measurements and the other still active with olive crops. And two control sites non-terraced. We used the paired plot strategy to compare the impact of terracing and abandonment. At each site we collected randomly 50 soil samples at 0-2 cm, 4-6 and 8-10 cm depth. At each sampling point 100 WDPT measurements where carried out, and one sample for the bulk density, and one for the organic matter, and one for the soil aggregate stability were collected. The soil surface samples shown the largest differences. The

  5. High-density polyethylene dosimetry by transvinylene FTIR analysis

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Silverman, J.; Al-Sheikhly, M.;

    1999-01-01

    spectrophotometric analysis. The measured product of linear molar extinction coefficient and radiation chemical yield for transvinylene formation in this case is 3.22 x 10(-6) m(2) J(-1), and G(-CH=CH-)= 0.116 mu mol J(-1) = 1.12 (100 eV)(-1). The estimated uncertainty for deriving these values by this method...

  6. Sensitivity analysis of crustal correction for calculation of lithospheric mantle density from gravity data

    DEFF Research Database (Denmark)

    Herceg, Matija; Artemieva, Irina; Thybo, Hans

    2016-01-01

    We investigate how uncertainties in seismic and density structure of the crust propagate to uncertainties in mantle density structure. The analysis is based on interpretation of residual upper-mantle gravity anomalies which are calculated by subtracting (stripping) the gravitational effect of the...

  7. Isotopic analysis of bulk, LMW, and HMW DON d15N indicates recycled nitrogen release from marine DON

    Science.gov (United States)

    Knapp, A. N.; Sigman, D. M.; Lipschultz, F.; Kustka, A.; Capone, D. G.

    2010-12-01

    Nitrogen (N) concentration and stable isotope ratio (d15N) measurements were made on bulk and size fractionated surface ocean dissolved organic nitrogen (DON) samples collected in the oligotrophic North Atlantic and Pacific Oceans. The bulk DON concentration in the upper 100 m is similar between the North Atlantic and North Pacific, between 4.5 and 5.0 uM, but the average d15N of bulk DON is significantly different, 3.9 per mil vs. air in the North Atlantic and 4.7 per mil in the North Pacific. The d15N of both bulk and HMW DON from the western tropical North Atlantic are similar to previous measurements, ~4.0 to 4.5 per mil. We report the first measurements of LMW DON d15N, which is consistently lower than HMW DON d15N. Neither the concentration nor d15N of bulk or size-fractionated DON varied with in situ N2 fixation rate, although significant variation in bulk and LMW DON d15N was observed between January and July of the same year in the western tropical North Atlantic. We propose a conceptual model to explain 1) the elevated d15N of bulk DON relative to other surface ocean N pools and fluxes, 2) the elevation of HMW DON d15N relative to LMW DON d15N, and 3) the inter-basin difference in the d15N of bulk DON. In this model, DON is produced from suspended particulate organic nitrogen (PON) without isotope fractionation because the conversion from PON to DON largely does not involve N-bearing bonds. In contrast, deamination and amide hydrolysis, with N isotope effects of 3 to 10 per mil, are major mechanisms by which DON is converted to ammonia and/or to other simple N compounds (e.g., amino acids). Thus these N-specific DON loss reactions result in an elevated d15N of residual DON relative to the parent DON and therefore also to the PON source. Moreover, the ammonium and simple organic N compounds released by microbial DON degradation are efficiently reassimilated back into the PON pool, as an integral part of the regenerated N cycle that further lowers the d15N

  8. Strontium speciation during reaction of kaolinite with simulated tank-waste leachate: bulk and microfocused EXAFS analysis.

    Science.gov (United States)

    Choi, Sunkyung; O'Day, Peggy A; Rivera, Nelson A; Mueller, Karl T; Vairavamurthy, Murthy A; Seraphin, Supapan; Chorover, Jon

    2006-04-15

    Radioactive strontium (90Sr) is an important constituent of the complex wastes from past nuclear weapons production and has been stored in underground tanks at U.S. DOE sites (e.g., Hanford, WA). Using bulk and microfocused EXAFS spectroscopy, we examined temporal changes in solid-phase Sr speciation in kaolinite samples reacted for 1-369 d with high-pH, high ionic strength synthetic tank-waste leachate containing Sr(2+) and Cs(+) at 10(-3) mol kg(-1). Analyses of bulk EXAFS spectra showed that Sr initially forms a precipitate by 7 d with a local structure similar to SrCO(3-) (s). At 33 d, microfocused EXAFS of individual particles in one sample revealed a mixture of hydrated and dehydrated Sr associated with neoformed sodalite-type phases. At aging times of 93 d and longer, bulk EXAFS spectra and supporting characterizations indicated nonexchangeable Sr with a local structure consistent with incorporation into increasingly crystalline aluminosilicate particles, particularly sodalite. These experimental studies suggest that irreversible trapping of radionuclides occurs if they are present during the formation and aging of feldspathoid alteration products of local Si-bearing sediment minerals. This may serve as an effective contaminant sequestration mechanism at sites such as Hanford.

  9. An empirical analysis of freight rate and vessel price volatility transmission in global dry bulk shipping market

    Directory of Open Access Journals (Sweden)

    Lei Dai

    2015-10-01

    Full Text Available Global dry bulk shipping market is an important element of global economy and trade. Since newbuilding and secondhand vessels are often traded as assets and the freight rate is the key determinant of vessel price, it is important for shipping market participants to understand the market dynamics and price transmission mechanism over time to make suitable strategic decisions. To address this issue, a multi-variate GARCH model was applied in this paper to explore the volatility spillover effects across the vessel markets (including newbuilding and secondhand vessel markets and freight market. Specifically, the BEKK parameterization of the multi-variate GARCH model (BEKK GARCH was proposed to capture the volatility transmission effect from the freight market, newbuilding and secondhand vessel markets in the global dry bulk shipping industry. Empirical results reveal that significant volatility transmission effects exist in each market sector, i.e. capesize, panamax, handymax and handysize. Besides, the market volatility transmission mechanism varies among different vessel types. Moreover, some bilateral effects are found in the dry bulk shipping market, showing that lagged variances could affect the current variance in a counterpart market, regardless of the volatility transmission. A simple ratio is proposed to guide investors optimizing their portfolio allocations. The findings in this paper could provide unique insights for investors to understand the market and hedge their portfolios well.

  10. Analysis of bulked segregants to identify molecular markers linked with cocoon weight and cocoon shell weight in the silkworm Bombyx mori L

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two silkworm strains viz, B20 A (high cocoon shell ratio) and C.Nichi (low cocoon shell ratio) were sib mated for 10 generations to determine the homozygosis. Both bulked segregant analysis(BSA) and near isogenic lines (NIL) studies were done to identify the RFLP markers closely linked to cocoon shell parameters. Three hundred and fifty-two random clones were identified as the low copy number sequence and used for identification of Restriction Fragment Length Polymorphic (RFLP) marker linked to cocoon weight and cocoon shell character. In the bulk segregant analysis, DNA from the parents (B20 A, C.Nichi), F1 and F2 progeny of high shell ratio (HSR) and low shell ratio (LSR) were screened for hybridization with the random clones. Polymorphic banding pattern achieved through southern hybridization with different probes indicated the probable correlation of polymorphism with high and low cocoon shell character which are possible landmarks in identifying the putative marker(s) for the cocoon shell character. Out of the 100 probes tried with parents, F1, F2 and their bulks, 10 probes were found to be closely linked to cocoon shell characters.

  11. Evaluation and Bulked Segregant Analysis of Major Yield QTL qtl12.1 Introgressed into Indigenous Elite Line for Low Water Availability under Water Stress

    Institute of Scientific and Technical Information of China (English)

    N.Manikanda BOOPATHI; Gat SWAPNASHRI; P.KAVITHA; S.SATHISH; R.NITHYA; Wickneswari RATNAM; Arvind KUMAR

    2013-01-01

    Near isogenic lines carrying large-effect QTL (qtl12.1),which has a consistent influence on grain yield under upland drought stress conditions in a wide range of environments,were evaluated under water stress in the fields.The line which gave higher yield under drought was crossed with a local elite line,PMK3,and forwarded to F2:3 generation.Significant variation was found among the F2:3 lines for agronomic traits under water stress in the fields.Low to high broad sense heritability (H) for investigated traits was also found.Water stress indicators such as leaf rolling and leaf drying were negatively correlated with plant height,biomass and grain yield under stress.Bulked segregant analysis (BSA) was performed with the markers in the vicinity of qtl12.1,and RM27933 was found to be segregated perfectly well in individual components of drought resistant and drought susceptible bulks which were bulked based on yield under water stress among F2:3 lines.Hence,this simple and breeder friendly marker,RM27933,may be useful as a potentially valuable candidate marker for the transfer of the QTL qtl12.1 in the regional breeding program.Bioinformatic analysis of the DNA sequence of the qtl12.1 region was also done to identify and analyze positional candidate genes associated with this QTL and to ascertain the putative molecular basis of qtl12.1.

  12. Towards risk-based management of critical infrastructures : enabling insights and analysis methodologies from a focused study of the bulk power grid.

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Bryan T.; LaViolette, Randall A.; Cook, Benjamin Koger

    2008-02-01

    This report summarizes research on a holistic analysis framework to assess and manage risks in complex infrastructures, with a specific focus on the bulk electric power grid (grid). A comprehensive model of the grid is described that can approximate the coupled dynamics of its physical, control, and market components. New realism is achieved in a power simulator extended to include relevant control features such as relays. The simulator was applied to understand failure mechanisms in the grid. Results suggest that the implementation of simple controls might significantly alter the distribution of cascade failures in power systems. The absence of cascade failures in our results raises questions about the underlying failure mechanisms responsible for widespread outages, and specifically whether these outages are due to a system effect or large-scale component degradation. Finally, a new agent-based market model for bilateral trades in the short-term bulk power market is presented and compared against industry observations.

  13. Statistical Analysis of the Spectral Density Estimate Obtained via Coifman Scaling Function

    OpenAIRE

    2007-01-01

    Spectral density built as Fourier transform of covariance sequence of stationary random process is determining the process characteristics and makes for analysis of it’s structure. Thus, one of the main problems in time series analysis is constructing consistent estimates of spectral density via successive, taken after equal periods of time observations of stationary random process. This article is devoted to investigation of problems dealing with application of wavelet anal...

  14. Densidade de um planossolo sob sistemas de cultivo avaliada por meio da tomografia computadorizada de raios gama Bulk density of an alfisol under cultivation systems in a long-term experiment evaluated with gamma ray computed tomography

    Directory of Open Access Journals (Sweden)

    Adilson Luís Bamberg

    2009-10-01

    lowland soils is based on the use of crop rotation and succession, which are essential for the control of red and black rice. The effects on the soil properties deserve studies, particularly on soil compaction. The objective of this study was to identify compacted layers in an Albaqualf under different cultivation and tillage systems, by evaluating the soil bulk density (Ds with Gamma Ray Computed Tomography (TC. The analysis was carried out in a long-term experiment, from 1985 to 2004, at an experimental station of Embrapa Clima Temperado, Capão do Leão, RS, Brazil, in a random block design with seven treatments, with four replications (T1 - one year rice with conventional tillage followed by two years fallow; T2 - continuous rice under conventional tillage; T4 - rice and soybean (Glycine Max L. rotation under conventional tillage; T5 - rice, soybean and corn (Zea maize L. rotation under conventional tillage; T6 - rice under no-tillage in the summer in succession to rye-grass (Lolium multiflorum L. in the winter; T7 - rice under no-tillage and soybean under conventional tillage rotation; T8 - control: uncultivated soil. The Gamma Ray Computed Tomography method did not identify compacted soil layers under no-tillage rice in succession to rye-grass; two fallow years in the irrigated rice production system did not prevent the formation of a compacted layer at the soil surface; and in the rice, soybean and corn rotation under conventional tillage two compacted layers were identified (0.0 to 1.5 cm and 11 to 14 cm, indicating that they may restrict the agricultural production in this cultivation system on Albaqualf soils.

  15. Soil bulk density and biomass partitioning of Brachiaria decumbens in a silvopastoral system Densidade do solo e partição de biomassa de Brachiaria decumbens em um sistema silvopastoril

    Directory of Open Access Journals (Sweden)

    Domingos Sávio Campos Paciullo

    2010-10-01

    Full Text Available Shade in silvopastoral systems improves the thermal comfort of animals, but it may also affect the pasture productivity and can contribute to soil compaction in the shaded areas due to the increase in the number of animals looking for comfort. The effect of grazing at various distances from tree rows (under the tree canopy, at 6 and at 12 m away from the trees on the soil bulk density and on the aerial and root biomass of Brachiaria decumbens was evaluated in both the dry and the rainy seasons. The study was carried out on an Orthic Ferralsol in a randomized block design with two replications. Tree rows were composed of Eucalyptus grandis and Acacia mangium species, and the paddocks were submitted to a rotational stocking management, using Holstein (Bos taurus × Zebu (Bos indicus heifers. The shade intensity in the pasture decreased with an increasing distance from the tree row. Soil bulk density did not vary with the distance from the tree row, but varied seasonally, being greater in the rainy season (1.47 g cm-3 than in the dry season (1.28 g cm-3. Green forage and root mass, expressed as dry matter, were lower under the tree canopy and were greater in the rainy season. There were decreases of 22.3 and 41.4% in the aerial and root biomasses, respectively, in the tree rows. The greatest shoot/root ratio for B. decumbens under moderate and intensive shading indicates a modification in the forage biomass allocation pattern that favours the aerial development in detriment of the root system.O sombreamento em sistemas silvipastoris concorre para o conforto térmico dos animais; no entanto pode afetar a produção do pasto e contribuir para a compactação do solo, pelo aumento da concentração de animais nas áreas sombreadas. Avaliou-se o efeito da distância do renque de árvores (sob a copa das árvores, 6 e 12 m de distancia das árvores na densidade do solo e na biomassa aérea e de raízes de Brachiaria decumbens, nas épocas seca e chuvosa

  16. Universal properties of bulk viscosity near the QCD phase transition

    CERN Document Server

    Karsch, F; Tuchin, K

    2008-01-01

    We extract the bulk viscosity of hot quark-gluon matter in the presence of light quarks from the recent lattice data on the QCD equation of state. For that purpose we extend the sum rule analysis by including the contribution of light quarks. We also discuss the universal properties of bulk viscosity in the vicinity of a second order phase transition, as it might occur in the chiral limit of QCD at fixed strange quark mass and most likely does occur in two-flavor QCD. We point out that a chiral transition in the O(4) universality class at zero baryon density as well as the transition at the chiral critical point which belongs to the Z(2) universality class both lead to the critical behavior of bulk viscosity. In particular, the latter universality class implies the divergence of the bulk viscosity, which may be used as a signature of the critical point. We discuss the physical picture behind the dramatic increase of bulk viscosity seen in our analysis, and devise possible experimental tests of related phenome...

  17. Amorphous LiCoO2sbnd Li2SO4 active materials: Potential positive electrodes for bulk-type all-oxide solid-state lithium batteries with high energy density

    Science.gov (United States)

    Nagao, Kenji; Hayashi, Akitoshi; Deguchi, Minako; Tsukasaki, Hirofumi; Mori, Shigeo; Tatsumisago, Masahiro

    2017-04-01

    Newly amorphous Li2-x/100Cox/100S1-x/100O4-x/50 (xLiCoO2·(100-x)Li2SO4 (mol%)) positive electrode active materials are synthesized using mechanochemical techniques. SEM observation indicates that average radii of the Li1.2Co0.8S0.2O2.4 (80LiCoO2·20Li2SO4 (mol%)) particles are about 3 μm. HR-TEM images indicate that the particles comprise nano-crystalline and amorphous phases. The crystalline phase is attributable to cubic LiCoO2 phase. These active materials exhibit a high electronic conductivity of around 10-5-10-1 S cm-1 and an ionic conductivity of around 10-7-10-6 S cm-1 at room temperature. Bulk-type all-oxide solid-state cells (Lisbnd In alloy/Li3BO3-based glass-ceramic electrolyte/amorphous Li2-x/100Cox/100S1-x/100O4-x/50) are fabricated by pressing at room temperature without high temperature sintering. Although the cell with the milled LiCoO2 shows no capacity, the cell using the Li1.2Co0.8S0.2O2.4 electrode with no conductive components (ca. 150 μm thickness) operates as a secondary battery at 100 °C, with an average discharge potential of 3.3 V (vs. Li+/Li) and discharge capacity of 163 mAh g-1. A positive electrode with large amounts of active materials is suitable for achieving high energy density in all-solid-state batteries. These newly synthesized amorphous Li2-x/100Cox/100S1-x/100O4-x/50 electrodes with ionic and electronic conductivities and good processability meet that demand.

  18. Calculation of thermal neutron self-shielding correction factors for aqueous bulk sample prompt gamma neutron activation analysis using the MCNP code

    Energy Technology Data Exchange (ETDEWEB)

    Nasrabadi, M.N. [Department of Physics, Faculty of Science, University of Kashan, Km. 6, Ravand Road, Kashan (Iran, Islamic Republic of)], E-mail: mnnasri@kashanu.ac.ir; Jalali, M. [Isfahan Nuclear Science and Technology Research Institute, Atomic Energy organization of Iran (Iran, Islamic Republic of); Mohammadi, A. [Department of Physics, Faculty of Science, University of Kashan, Km. 6, Ravand Road, Kashan (Iran, Islamic Republic of)

    2007-10-15

    In this work thermal neutron self-shielding in aqueous bulk samples containing neutron absorbing materials is studied using bulk sample prompt gamma neutron activation analysis (BSPGNAA) with the MCNP code. The code was used to perform three dimensional simulations of a neutron source, neutron detector and sample of various material compositions. The MCNP model was validated against experimental measurements of the neutron flux performed using a BF{sub 3} detector. Simulations were performed to predict thermal neutron self-shielding in aqueous bulk samples containing neutron absorbing solutes. In practice, the MCNP calculations are combined with experimental measurements of the relative thermal neutron flux over the sample's surface, with respect to a reference water sample, to derive the thermal neutron self-shielding within the sample. The proposed methodology can be used for the determination of the elemental concentration of unknown aqueous samples by BSPGNAA where knowledge of the average thermal neutron flux within the sample volume is required.

  19. Analysis of bulked segregants to identify molecular markers linked with cocoon weight and cocoon shell weight in the silkworm Bombyx mori L

    Institute of Scientific and Technical Information of China (English)

    SateeshKumar; 徐孟奎; 陈玉银; Ponnuvel,K.M; Datta,R.K

    2002-01-01

    Two silkworm strains viz, B20 A (high cocoon shell ratio) and C. Nichi (low cocoon shell ratio) were sib mated for 10 generations to determine the homozygoeis. Both bulked segregant analysis (BSA) and near isogenic lines (NIL) studies were done to identify the RFLP markers doaely linked to cocoon shell parameters. Three hundred and fifty-two random clones were identified as the low copy number 'sequeiace and used for identification of Restriction Fragment Length Polyrnorphic (RFLP) marker linked to cocoon weight and cocoon shell character. In the bulk aegregant analysia, DNA from the parents (B20 A, C.Nichi), Fl and F2 progeny of high shell ratio (HSR) and low shell ratio (LSR) were screened for hybridization with the random clones. Polymorphic banding pattern achieved through southern hybridization with different probes indicated the probable correlation of polymorphism with high and low cocoon shell character which are possible landmarks in identifying the putative marker(s) for the cocoon shell character. Out of the 100 probes tried with parents, Fl, F2 and their bulks 10 probes were found to be closely linked to cocoon shell characters.

  20. Short-term bulk energy storage system scheduling for load leveling in unit commitment: modeling, optimization, and sensitivity analysis.

    Science.gov (United States)

    Hemmati, Reza; Saboori, Hedayat

    2016-05-01

    Energy storage systems (ESSs) have experienced a very rapid growth in recent years and are expected to be a promising tool in order to improving power system reliability and being economically efficient. The ESSs possess many potential benefits in various areas in the electric power systems. One of the main benefits of an ESS, especially a bulk unit, relies on smoothing the load pattern by decreasing on-peak and increasing off-peak loads, known as load leveling. These devices require new methods and tools in order to model and optimize their effects in the power system studies. In this respect, this paper will model bulk ESSs based on the several technical characteristics, introduce the proposed model in the thermal unit commitment (UC) problem, and analyze it with respect to the various sensitive parameters. The technical limitations of the thermal units and transmission network constraints are also considered in the model. The proposed model is a Mixed Integer Linear Programming (MILP) which can be easily solved by strong commercial solvers (for instance CPLEX) and it is appropriate to be used in the practical large scale networks. The results of implementing the proposed model on a test system reveal that proper load leveling through optimum storage scheduling leads to considerable operation cost reduction with respect to the storage system characteristics.

  1. Invariant density analysis: modeling and analysis of the postural control system using Markov chains.

    Science.gov (United States)

    Hur, Pilwon; Shorter, K Alex; Mehta, Prashant G; Hsiao-Wecksler, Elizabeth T

    2012-04-01

    In this paper, a novel analysis technique, invariant density analysis (IDA), is introduced. IDA quantifies steady-state behavior of the postural control system using center of pressure (COP) data collected during quiet standing. IDA relies on the analysis of a reduced-order finite Markov model to characterize stochastic behavior observed during postural sway. Five IDA parameters characterize the model and offer physiological insight into the long-term dynamical behavior of the postural control system. Two studies were performed to demonstrate the efficacy of IDA. Study 1 showed that multiple short trials can be concatenated to create a dataset suitable for IDA. Study 2 demonstrated that IDA was effective at distinguishing age-related differences in postural control behavior between young, middle-aged, and older adults. These results suggest that the postural control system of young adults converges more quickly to their steady-state behavior while maintaining COP nearer an overall centroid than either the middle-aged or older adults. Additionally, larger entropy values for older adults indicate that their COP follows a more stochastic path, while smaller entropy values for young adults indicate a more deterministic path. These results illustrate the potential of IDA as a quantitative tool for the assessment of the quiet-standing postural control system.

  2. Cosmic bulk flows on 50 {h}^{-1}$Mpc scales: A Bayesian hyper-parameter method and multi-shells likelihood analysis

    CERN Document Server

    Ma, Yin-Zhe

    2012-01-01

    It has been argued recently that the galaxy peculiar velocity field provides evidence of excessive power on scales of $50\\hmpc$, which seems to be inconsistent with the standard $\\Lambda$CDM cosmological model. We discuss several assumptions and conventions used in studies of the large-scale bulk flow to check whether this claim is robust under a variety of conditions. Rather than using a composite catalogue we select samples from the SN, ENEAR, SFI++ and A1SN catalogues, and correct for Malmquist bias in each according to the IRAS PSCz density field. We also use slightly different assumptions about the small-scale velocity dispersion and the parameterisation of the matter power spectrum when calculating the variance of the bulk flow. By combining the likelihood of individual catalogues using a Bayesian hyper-parameter method, we find that the joint likelihood of the amplitude parameter gives $\\sigma_8=0.65^{+0.47}_{-0.35}(\\pm 1 \\sigma)$, which is entirely consistent with the $\\Lambda$CDM model. In addition, ...

  3. A perturbative analysis of Quasi-Radial density waves in galactic disks

    CERN Document Server

    Hernandez, X

    2011-01-01

    The theoretical understanding of density waves in disk galaxies starts from the classical WKB perturbative analysis of tight-winding perturbations, the key assumption being that the potential due to the density wave is approximately radial. The above has served as a valuable guide in aiding the understanding of both simulated and observed galaxies, in spite of a number of caveats being present. The observed spiral or bar patterns in real galaxies are frequently only marginally consistent with the tight-winding assumption, often in fact, outright inconsistent. Here we derive a complementary formulation to the problem, by treating quasi-radial density waves under simplified assumptions in the linear regime. We assume that the potential due to the density wave is approximately tangential, and derive the corresponding dispersion relation of the problem. We obtain an instability criterion for the onset of quasi-radial density waves, which allows a clear understanding of the increased stability of the higher order ...

  4. Comparison and statistical analysis of four write stability metrics in bulk CMOS static random access memory cells

    Science.gov (United States)

    Qiu, Hao; Mizutani, Tomoko; Saraya, Takuya; Hiramoto, Toshiro

    2015-04-01

    The commonly used four metrics for write stability were measured and compared based on the same set of 2048 (2k) six-transistor (6T) static random access memory (SRAM) cells by the 65 nm bulk technology. The preferred one should be effective for yield estimation and help predict edge of stability. Results have demonstrated that all metrics share the same worst SRAM cell. On the other hand, compared to butterfly curve with non-normality and write N-curve where no cell state flip happens, bit-line and word-line margins have good normality as well as almost perfect correlation. As a result, both bit line method and word line method prove themselves preferred write stability metrics.

  5. Analysis of Vertical Oscillations of a Permanent Magnet Freely Levitated above an YBCO Bulk in an AC External Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    Yong Zhang; Ya-Li Zhang; Cui-Hua Cheng; Yong Zhao

    2008-01-01

    The effect of the moving speed of perma- nent magnet (PM) on levitation force between PM and high temperature superconducting (HTS) bulk is analyzed and described in the PM-HTS levitation system. The PM vibration characteristic in the PM-HTS system is investigated. The PM may collide with the HTS in vibration if the amplitude and frequency of driving force satisfy the relationship Pmin = A f n. When the load of the system is below a threshold, the minimal collision amplitude of the driving force increases with the load increasing, however, it sharply drops to zero when the load exceeds the threshold. With the increase of the initial height of the PM, the threshold load increases, but the minimal driving force which causes a collision between PM and HTS decreases.

  6. Flow-through Bulk Optode for Spectrophotometric Determination of Thiocyanate and Its Application to Water and Saliva Analysis

    Directory of Open Access Journals (Sweden)

    José Fernández

    2006-10-01

    Full Text Available A flow-through spectrophotometric bulk optode for the flow-injectiondetermination of thiocyanate is described. As active constituents, the optode incorporatesthe lipophilized pH indicator 5-octadecanoyloxy-2-(4-nitrophenylazophenol andmethyltridodecyl ammonium chloride, dissolved in a plasticized poly(vinylchloridemembrane entrapped in a cellulose support. The optode is applied, in conjunction with theflow injection technique, to the determination of thiocyanate at pH 7.5 (TRIS/H2SO4. Thesensor is readily regenerated with a 10-2 M NaOH carrier solution. The analyticalcharacteristics of this optode with respect to thiocyanate response time, dynamicmeasurement range, reproducibility and selectivity are discussed. The proposed FI methodis applied to the determination of thiocyanate in waters from different sources and in humansaliva samples in order to distinguish between smokers and non-smokers.

  7. Herd-prevalence of Coxiella burnetii (Q fever) antibodies in dairy cattle farms based on bulk tank milk analysis

    Institute of Scientific and Technical Information of China (English)

    Mohammad Khalili; Ehsanollah Sakhaee; Mohammad Reza Aflatoonian; Naser Shahabi-Nejad

    2011-01-01

    Objective: To determine the prevalence of Coxiella burnetii (C. burnetii) antibody positive randomly selected dairy herds in southeast Iran (Kerman). Methods: Bulk tank milk samples were collected randomly from 44 sufficiently large commercial dairy herds, included near 12 000 dairy cattle, in Kerman (The largest province of Iran), southeast Iran. The samples were tested for antibodies against C. burnetii using the commercial CHEKIT® Q fever antibody ELISA Test Kit (Idexx, Liebefeld-Bern, Switzerland). Results: The prevalence of positive, negative and intermediate herds were 45.4%, 43.2% and 11.4%, respectively. Conclusions: The result supports the hypothesis of high prevalence and endemic pattern of Q fever in Iran. This investigation highlights the importance of further studies on Q fever in Iran.

  8. Electrical analysis of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors on flexible bulk mono-crystalline silicon

    KAUST Repository

    Ghoneim, Mohamed T.

    2015-06-01

    We report on the electrical study of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors (MOSCAPs) on a flexible ultra-thin (25 μm) silicon fabric which is peeled off using a CMOS compatible process from a standard bulk mono-crystalline silicon substrate. A lifetime projection is extracted using statistical analysis of the ramping voltage (Vramp) breakdown and time dependent dielectric breakdown data. The obtained flexible MOSCAPs operational voltages satisfying the 10 years lifetime benchmark are compared to those of the control MOSCAPs, which are not peeled off from the silicon wafer. © 2014 IEEE.

  9. Analysis of sources of bulk conductivity change in saturated silica sand after unbuffered TCE oxidation by permanganate.

    Science.gov (United States)

    Hort, Ryan D; Revil, André; Munakata-Marr, Junko

    2014-09-01

    Time lapse resistivity surveys could potentially improve monitoring of permanganate-based in situ chemical oxidation (ISCO) of organic contaminants such as trichloroethene (TCE) by tracking changes in subsurface conductivity that result from injection of permanganate and oxidation of the contaminant. Bulk conductivity and pore fluid conductivity changes during unbuffered TCE oxidation using permanganate are examined through laboratory measurements and conductivity modeling using PHREEQC in fluid samples and porous media samples containing silica sand. In fluid samples, oxidation of one TCE molecule produces three chloride ions and one proton, resulting in an increase in fluid electrical conductivity despite the loss of two permanganate ions in the reaction. However, in saturated sand samples in which up to 8mM TCE was oxidized, at least 94% of the fluid conductivity associated with the presence of protons was removed within 3h of sand contact, most likely through protonation of silanol groups found on the surface of the sand grains. Minor conductivity effects most likely associated with pH-dependent reductive dissolution of manganese dioxide were also observed but not accounted for in pore-fluid conductivity modeling. Unaccounted conductivity effects resulted in an under-calculation of post-reaction pore fluid conductivity of 2.1% to 5.5%. Although small increases in the porous media formation factor resulting from precipitation of manganese dioxide were detected (about 3%), these increases could not be confirmed to be statistically significant. Both injection of permanganate and oxidation of TCE cause increases in bulk conductivity that would be detectable through time-lapse resistivity surveys in field conditions.

  10. Creating bulk nanocrystalline metal.

    Energy Technology Data Exchange (ETDEWEB)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  11. The Visualization and Analysis of POI Features under Network Space Supported by Kernel Density Estimation

    Directory of Open Access Journals (Sweden)

    YU Wenhao

    2015-01-01

    Full Text Available The distribution pattern and the distribution density of urban facility POIs are of great significance in the fields of infrastructure planning and urban spatial analysis. The kernel density estimation, which has been usually utilized for expressing these spatial characteristics, is superior to other density estimation methods (such as Quadrat analysis, Voronoi-based method, for that the Kernel density estimation considers the regional impact based on the first law of geography. However, the traditional kernel density estimation is mainly based on the Euclidean space, ignoring the fact that the service function and interrelation of urban feasibilities is carried out on the network path distance, neither than conventional Euclidean distance. Hence, this research proposed a computational model of network kernel density estimation, and the extension type of model in the case of adding constraints. This work also discussed the impacts of distance attenuation threshold and height extreme to the representation of kernel density. The large-scale actual data experiment for analyzing the different POIs' distribution patterns (random type, sparse type, regional-intensive type, linear-intensive type discusses the POI infrastructure in the city on the spatial distribution of characteristics, influence factors, and service functions.

  12. The gluon density of the proton at low x from a QCD analysis of F$_{2}$

    CERN Document Server

    Aïd, S; Andrieu, B; Appuhn, R D; Arpagaus, M; Babaev, A; Ban, Y; Baranov, P S; Barrelet, E; Barschke, R; Bartel, Wulfrin; Barth, Monique; Bassler, U; Beck, H P; Behrend, H J; Belousov, A; Berger, C; Bernardi, G; Bernet, R; Bertrand-Coremans, G H; Besançon, M; Beyer, R; Biddulph, P; Bispham, P; Bizot, J C; Blobel, Volker; Borras, K; Botterweck, F; Boudry, V; Braemer, A; Brasse, F W; Braunschweig, W; Brisson, V; Bruncko, Dusan; Brune, C R; Buchholz, R; Buniatian, A Yu; Burke, S; Burton, M; Buschhorn, G W; Bán, J; Bähr, J; Büngener, L; Bürger, J; Büsser, F W; Campbell, A J; Carli, T; Charles, F; Charlet, M; Chernyshov, V; Clarke, D; Clegg, A B; Clerbaux, B; Colombo, M G; Contreras, J G; Cormack, C; Coughlan, J A; Courau, A; Coutures, C; Cozzika, G; Criegee, L; Cussans, D G; Cvach, J; Dagoret, S; Dainton, J B; Dau, W D; Daum, K; David, M; De Wolf, E A; Del Buono, L; Delcourt, B; Di Nezza, P; Dollfus, C; Dowell, John D; Dreis, H B; Droutskoi, A; Duboc, J; Duhm, H; Düllmann, D; Dünger, O; Ebert, J; Ebert, T R; Eckerlin, G; Efremenko, V; Egli, S; Eichenberger, S; Eichler, R; Eisele, Franz; Eisenhandler, Eric F; Ellison, R J; Elsen, E E; Erdmann, M; Erdmann, W; Erlichmann, H; Evrard, E; Favart, L; Fedotov, A; Feeken, D; Felst, R; Feltesse, Joel; Ferencei, J; Ferrarotto, F; Flamm, K; Fleischer, M; Flieser, M; Flügge, G; Fomenko, A; Fominykh, B A; Forbush, M; Formánek, J; Foster, J M; Franke, G; Fretwurst, E; Gabathuler, Erwin; Gabathuler, K; Garvey, J; Gayler, J; Gebauer, M; Gellrich, A; Genzel, H; Gerhards, R; Glazov, A; Goerlach, U; Gogitidze, N; Goldberg, M; Goldner, D; González-Pineiro, B; Gorelov, I V; Goritchev, P A; Grab, C; Greenshaw, T J; Grindhammer, G; Gruber, A; Gruber, C; Grässler, Herbert; Grässler, R; Görlich, L; Haack, J; Haidt, Dieter; Hajduk, L; Hamon, O; Hampel, M; Hapke, M; Haynes, W J; Heatherington, J; Heinzelmann, G; Henderson, R C W; Henschel, H; Herynek, I; Hess, M F; Hildesheim, W; Hill, P; Hiller, K H; Hilton, C D; Hladky, J; Hoeger, K C; Horisberger, R P; Hudgson, V L; Huet, Patrick; Hufnagel, H; Höppner, M; Hütte, M; Ibbotson, M; Itterbeck, H; Jabiol, M A; Jacholkowska, A; Jacobsson, C; Jaffré, M; Janoth, J; Jansen, T; Johnson, D P; Johnson, L; Jung, H; Jönsson, L B; Kalmus, Peter I P; Kant, D; Kaschowitz, R; Kasselmann, P; Kathage, U; Katzy, J M; Kaufmann, H H; Kazarian, S; Kenyon, Ian Richard; Kermiche, S; Keuker, C; Kiesling, C; Klein, M; Kleinwort, C; Knies, G; Ko, W; Kolanoski, H; Kole, F; Kolya, S D; Korbel, V; Korn, M; Kostka, P; Kotelnikov, S K; Krasny, M W; Krehbiel, H; Krämerkämper, T; Krücker, D; Krüger, U P; Krüner-Marquis, U; Kuhlen, M; Kurca, T; Kurzhöfer, J; Kuznik, B; Köhler, T; Köhne, J H; Küster, H; Lacour, D; Lamarche, F; Lander, R; Landon, M P J; Lange, W; Lanius, P; Laporte, J F; Lebedev, A; Lehner, F; Leverenz, C; Levonian, S; Ley, C; Lindström, G; Link, J; Linsel, F; Lipinski, J; List, B; Lobo, G; Loch, P; Lohmander, H; Lomas, J W; Lubimov, V; López, G C; Lüke, D; Magnussen, N; Malinovskii, E I; Mani, S; Maracek, R; Marage, P; Marks, J; Marshall, R; Martens, J; Martin, G; Martin, R D; Martyn, H U; Martyniak, J; Masson, S; Mavroidis, A; Maxfield, S J; McMahon, S J; Mehta, A; Meier, K; Mercer, D; Merz, T; Meyer, C A; Meyer, H; Meyer, J; Migliori, A; Mikocki, S; Milstead, D; Moreau, F; Morris, J V; Mroczko, E; Murín, P; Müller, G; Müller, K; Nagovitsin, V; Nahnhauer, R; Naroska, Beate; Naumann, T; Newman, P R; Newton, D; Neyret, D; Nguyen, H K; Nicholls, T C; Niebergall, F; Niebuhr, C B; Niedzballa, C; Nisius, R; Nowak, G; Noyes, G W; Nyberg-Werther, M; Oakden, M N; Oberlack, H; Obrock, U; Olsson, J E; Ozerov, D; Panaro, E; Panitch, A; Pascaud, C; Patel, G D; Peppel, E; Phillips, J P; Pichler, C; Pitzl, D; Pope, G; Prell, S; Prosi, R; Pérez, E; Rabbertz, K; Raupach, F; Reimer, P; Reinshagen, S; Ribarics, P; Rick, Hartmut; Riech, V; Riedlberger, J; Riess, S; Rietz, M; Rizvi, E; Robertson, S M; Robmann, P; Roloff, H E; Roosen, R; Rosenbauer, K; Rostovtsev, A A; Rouse, F; Royon, C; Rusakov, S V; Rybicki, K; Rylko, R; Rädel, G; Rüter, K; Sahlmann, N; Sankey, D P C; Schacht, P; Schiek, S; Schleif, S; Schleper, P; Schmidt, D; Schmidt, G; Schröder, V; Schuhmann, E; Schwab, B; Schöning, A; Sciacca, G F; Sefkow, F; Seidel, M; Sell, R; Semenov, A A; Shekelian, V I; Shevyakov, I; Shtarkov, L N; Siegmon, G; Siewert, U; Sirois, Y; Skillicorn, Ian O; Smirnov, P; Smith, J R; Solochenko, V; Soloviev, Yu V; Spiekermann, J; Spielman, S; Spitzer, H; Starosta, R; Steenbock, M; Steffen, P; Steinberg, R; Stella, B; Stephens, K; Stier, J; Stiewe, J; Stolze, K; Strachota, J; Straumann, U; Struczinski, W; Stösslein, U; Sutton, J P; Tapprogge, Stefan; Thiebaux, C; Thompson, G; Truöl, P; Turnau, J; Tutas, J; Uelkes, P; Usik, A; Valkár, S; Valkárová, A; Vallée, C; Van Esch, P; Van Mechelen, P; Van den Plas, D; Vartapetian, A H; Vazdik, Ya A; Verrecchia, P; Villet, G; Wacker, K; Wagener, A; Wagener, M; Walther, A; Weber, G; Weber, M; Wegener, D; Wegner, A; Wellisch, H P; West, L R; Willard, S; Winde, M; Winter, G G; Wittek, C; Wright, A E; Wulff, N; Wünsch, E; Yiou, T P; Zarbock, D; Zhang, Z; Zhokin, A S; Zimmer, M; Zimmermann, W; Zomer, F; Zuber, K; Zácek, J; de Roeck, A; von Schlippe, W

    1995-01-01

    We present a QCD analysis of the proton structure function F_2 measured by the H1 experiment at HERA, combined with data from previous fixed target experiments. The gluon density is extracted from the scaling violations of F_2 in the range 2\\cdot 10^{-4}density is found to rise steeply with decreasing x.

  13. Analysis of the segmented contraction of basis functions using density matrix theory.

    Science.gov (United States)

    Custodio, Rogério; Gomes, André Severo Pereira; Sensato, Fabrício Ronil; Trevas, Júlio Murilo Dos Santos

    2006-11-30

    A particular formulation based on density matrix (DM) theory at the Hartree-Fock level of theory and the description of the atomic orbitals as integral transforms is introduced. This formulation leads to a continuous representation of the density matrices as functions of a generator coordinate and to the possibility of plotting either the continuous or discrete density matrices as functions of the exponents of primitive Gaussian basis functions. The analysis of these diagrams provides useful information allowing: (a) the determination of the most important primitives for a given orbital, (b) the core-valence separation, and (c) support for the development of contracted basis sets by the segmented method.

  14. Tapped density optimisation for four agricultural wastes - Part II: Performance analysis and Taguchi-Pareto

    Directory of Open Access Journals (Sweden)

    Ajibade Oluwaseyi Ayodele

    2016-01-01

    Full Text Available In this attempt, which is a second part of discussions on tapped density optimisation for four agricultural wastes (particles of coconut, periwinkle, palm kernel and egg shells, performance analysis for comparative basis is made. This paper pioneers a study direction in which optimisation of process variables are pursued using Taguchi method integrated with the Pareto 80-20 rule. Negative percentage improvements resulted when the optimal tapped density was compared with the average tapped density. However, the performance analysis between optimal tapped density and the peak tapped density values yielded positive percentage improvements for the four filler particles. The performance analysis results validate the effectiveness of using the Taguchi method in improving the tapped density properties of the filler particles. The application of the Pareto 80-20 rule to the table of parameters and levels produced revised tables of parameters and levels which helped to identify the factor-levels position of each parameter that is economical to optimality. The Pareto 80-20 rule also produced revised S/N response tables which were used to know the relevant S/N ratios that are relevant to optimality.

  15. [Estimation of Hunan forest carbon density based on spectral mixture analysis of MODIS data].

    Science.gov (United States)

    Yan, En-ping; Lin, Hui; Wang, Guang-xing; Chen, Zhen-xiong

    2015-11-01

    With the fast development of remote sensing technology, combining forest inventory sample plot data and remotely sensed images has become a widely used method to map forest carbon density. However, the existence of mixed pixels often impedes the improvement of forest carbon density mapping, especially when low spatial resolution images such as MODIS are used. In this study, MODIS images and national forest inventory sample plot data were used to conduct the study of estimation for forest carbon density. Linear spectral mixture analysis with and without constraint, and nonlinear spectral mixture analysis were compared to derive the fractions of different land use and land cover (LULC) types. Then sequential Gaussian co-simulation algorithm with and without the fraction images from spectral mixture analyses were employed to estimate forest carbon density of Hunan Province. Results showed that 1) Linear spectral mixture analysis with constraint, leading to a mean RMSE of 0.002, more accurately estimated the fractions of LULC types than linear spectral and nonlinear spectral mixture analyses; 2) Integrating spectral mixture analysis model and sequential Gaussian co-simulation algorithm increased the estimation accuracy of forest carbon density to 81.5% from 74.1%, and decreased the RMSE to 5.18 from 7.26; and 3) The mean value of forest carbon density for the province was 30.06 t · hm(-2), ranging from 0.00 to 67.35 t · hm(-2). This implied that the spectral mixture analysis provided a great potential to increase the estimation accuracy of forest carbon density on regional and global level.

  16. Tagging of Brown Planthopper Resistance Genes in F2s of IR50 × Ptb33 of Rice by Using Bulked Segregant Analysis

    Institute of Scientific and Technical Information of China (English)

    Venkateswarlu YADAVALLI; Gajendra P. NARWANE; M. S. R. KRISHNA; Nagarajan POTHI; Bharathi MUTHUSAMY

    2012-01-01

    Brown planthopper (Nilaparvata lugens Stǎl) is one of the most damaging pests causing hopper burn in rice,and thereby reducing the productivity and also the quality of the product.The effective management strategy to control this pest is the identification and transfer of desirable genes to local rice cultivars.The most important approach for developing resistant cultivars is the identification of markers,which can help in marker-assisted selection of more durable resistant genotype.The susceptible parent IR50 and the resistant parent Ptb33,and their F2 populations were used in bulked segregant analysis for identification of resistant genes with random amplified polymorphic DNA marker (RAPD) primers.The primers OPC7 and OPAG14 showed both dominant and susceptible specific banding pattern so called co-dominant markers.Moreover,OPC7697 and OPAG14660 showed resistant specific bands and thus being in coupling phase,whereas OPC7846 and OPAG14650 showed susceptible specific genotypic bands in bulked segregant analysis.Therefore,the coupling phase markers,OPC7697 and OPAG14680.are considered to be more useful in marker-assisted selection of rice genotypes in crop improvement.

  17. Simultaneous Analysis of Losartan Potassium, Amlodipine Besylate, and Hydrochlorothiazide in Bulk and in Tablets by High-Performance Thin Layer Chromatography with UV-Absorption Densitometry

    Directory of Open Access Journals (Sweden)

    Karunanidhi Santhana Lakshmi

    2012-01-01

    Full Text Available A Simple high-performance thin layer chromatography (HPTLC method for separation and quantitative analysis of losartan potassium, amlodipine, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to silica gel plates and developed with chloroform : methanol : acetone : formic acid 7.5 : 1.3 : 0.5 : 0.03 (/// as mobile phase. Zones were scanned densitometrically at 254 nm. The values of amlodipine besylate, hydrochlorothiazide, and losartan potassium were 0.35, 0.57, and 0.74, respectively. Calibration plots were linear in the ranges 500–3000 ng per spot for losartan potassium, amlodipine and hydrochlorothiazide, the correlation coefficients, r, were 0.998, 0.998, and 0.999, respectively. The suitability of this method for quantitative determination of these compounds was by validation in accordance with the requirements of pharmaceutical regulatory standards. The method can be used for routine analysis of these drugs in bulk and in formulation.

  18. Tracing the Fingerprint of Chemical Bonds within the Electron Densities of Hydrocarbons: A Comparative Analysis of the Optimized and the Promolecule Densities.

    Science.gov (United States)

    Keyvani, Zahra Alimohammadi; Shahbazian, Shant; Zahedi, Mansour

    2016-10-18

    The equivalence of the molecular graphs emerging from the comparative analysis of the optimized and the promolecule electron densities in two hundred and twenty five unsubstituted hydrocarbons was recently demonstrated [Keyvani et al. Chem. Eur. J. 2016, 22, 5003]. Thus, the molecular graph of an optimized molecular electron density is not shaped by the formation of the C-H and C-C bonds. In the present study, to trace the fingerprint of the C-H and C-C bonds in the electron densities of the same set of hydrocarbons, the amount of electron density and its Laplacian at the (3, -1) critical points associated with these bonds are derived from both optimized and promolecule densities, and compared in a newly proposed comparative analysis. The analysis not only conforms to the qualitative picture of the electron density build up between two atoms upon formation of a bond in between, but also quantifies the resulting accumulation of the electron density at the (3, -1) critical points. The comparative analysis also reveals a unified mode of density accumulation in the case of 2318 studied C-H bonds, but various modes of density accumulation are observed in the case of 1509 studied C-C bonds and they are classified into four groups. The four emerging groups do not always conform to the traditional classification based on the bond orders. Furthermore, four C-C bonds described as exotic bonds in previous studies, for example the inverted C-C bond in 1,1,1-propellane, are naturally distinguished from the analysis.

  19. Analysis of Nabumetone in Bulk and Tablet Formulation by a New and Validated Reverse Phase High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Prafulla Kumar Sahu

    2009-01-01

    Full Text Available RP-HPLC analytical method for the estimation of nabumetone in pharmaceutical dosage forms was developed and validated. A Hypersil ODS C18, 4.6 mm x 250 mm, 5 μm column from Supelco (India, with mobile phase comprised of acetonitrile: triple distilled water (50:50 with a total run time of 18 min was used and the wavelength of the detector was set at 230 nm. Stavudin is used as internal standard. The retention times were 14.167 min and 1.967 min for nabumetone and stavudin (IS respectively. The extraction recovery of nabumetone from pharmaceutical dosage form (tablets was >101% and the calibration curve was linear (r2 = 0.995 over nabumetone concentrations ranging from 1 to 200 µg/mL. The method had an accuracy of >99% and LOD and LOQ of 0.17482 µg/mL and 0.5827 µg/mL respectively. The method reported is simple, reliable, precise and accurate and has the capability of being used for determination of nabumetone in bulk and pharmaceutical dosage forms.

  20. New fermions in the bulk

    CERN Document Server

    de Brito, K P S

    2016-01-01

    Spinor fields on 5-dimensional Lorentzian manifolds are classified, according to the geometric Fierz identities that involve their bilinear covariants. Based upon this classification that generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are, hence, found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density, through the truncated exterior bundle. In order to accomplish a realisation of these new spinors, a Killing vector field is constructed on the horizon of 5-dimensional Kerr black holes. This Killing vector field is shown to reach the time-like Killing vector field at the spatial infinity, through a current 1-form density, constructed with the derived new spinor fields. The current density is, moreover, expressed as the f\\"unfbein components, assuming a condensed for...

  1. New fermions in the bulk

    Science.gov (United States)

    de Brito, K. P. S.; da Rocha, Roldão

    2016-10-01

    The spinor fields on 5-dimensional Lorentzian manifolds are classified according to the geometric Fierz identities, which involve their bilinear covariants. Based upon this classification, which generalises the celebrated 4-dimensional Lounesto classification of spinor fields, new non-trivial classes of 5-dimensional spinor fields are hence found, with important potential applications regarding bulk fermions and their subsequent localisation on brane-worlds. In addition, quaternionic bilinear covariants are used to derive the quaternionic spin density through the truncated exterior bundle. In order to accomplish the realisation of these new spinors, a Killing vector field is constructed on the horizon of a 5-dimensional Kerr black hole. This Killing vector field is shown to reach the time-like Killing vector field at spatial infinity through a current 1-form density, constructed with the new derived spinor fields. The current density is, moreover, expressed as the fünfbein component, assuming a condensed form.

  2. A topological analysis of charge densities in diamond, silicon and germanium crystals

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, Yu.A. [National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan); Okamura, F.P. [National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan)

    1997-03-01

    The Hansen-Coppens multipole model of charge density has been fitted to highly accurate published experimental and theoretical structure factors for diamond, silicon and germanium crystals. Analysis of both model experimental and theoretical charge densities using the resulting model parameters was performed in terms of Bader`s topological theory. The general topology of the charge density appeared to be identical for all crystals, containing the four possible types of critical points of rank three, and no non-nuclear attractors between neighboring atoms were found within achieved accuracy. Theoretical and experimental values of charge density and its Laplacian show quantitative and semiquantitative agreement, respectively, at the critical points of model charge densities. For Ge crystals, such agreement is worse at the ring critical point. These results suggest the possibility of semiquantitative (within 10-30%) study of the topological characteristics of highly accurate X-ray charge densities of crystals displaying shared interatomic interactions. Comparative topological analysis of the chemical bond in this series of crystals is discussed in terms of the quantum topological theory. (orig.).

  3. Charge-density analysis of 1-nitroindoline: refinement quality using free R factors and restraints.

    Science.gov (United States)

    Zarychta, Bartosz; Zaleski, Jacek; Kyzioł, Janusz; Daszkiewicz, Zdzisław; Jelsch, Christian

    2011-06-01

    Nitramines and related N-nitro compounds have attracted significant attention owing to their use in rocket fuel and as explosives. The charge density of 1-nitroindoline was determined experimentally and from theoretical calculations. Electron-density refinements were performed using the multipolar atom formalism. In order to design the ideal restraint strategy for the charge-density parameters, R-free analyses were performed involving a series of comprehensive refinements. Different weights were applied to the charge-density restraints, namely the similarity between chemically equivalent atoms and local symmetry. Additionally, isotropic thermal motion and an anisotropic model calculated by rigid-body analysis were tested on H atoms. The restraint weights which resulted in the lowest values of the averaged R-free factors and the anisotropic H-atom model were considered to yield the best charge density and were used in the final refinement. The derived experimental charge density along with intra- and intermolecular interactions was analysed and compared with theoretical calculations, notably with respect to the symmetry of multipole parameters. A comparison of different refinements suggests that the appropriate weighting scheme applied to charge-density restraints can reduce the observed artefacts. The topological bond orders of the molecule were calculated.

  4. Numerical analysis of atomic density distribution in arc driven negative ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T., E-mail: t.yamamoto@ppl.appi.keio.ac.jp; Shibata, T.; Hatayama, A. [Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan); Kashiwagi, M.; Hanada, M. [Japan Atomic Energy Agency (JAEA), 801-1 Mukouyama, Naka 311-0193 (Japan); Sawada, K. [Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)

    2014-02-15

    The purpose of this study is to calculate atomic (H{sup 0}) density distribution in JAEA 10 ampere negative ion source. A collisional radiative model is developed for the calculation of the H{sup 0} density distribution. The non-equilibrium feature of the electron energy distribution function (EEDF), which mainly determines the H{sup 0} production rate, is included by substituting the EEDF calculated from 3D electron transport analysis. In this paper, the H{sup 0} production rate, the ionization rate, and the density distribution in the source chamber are calculated. In the region where high energy electrons exist, the H{sup 0} production and the ionization are enhanced. The calculated H{sup 0} density distribution without the effect of the H{sup 0} transport is relatively small in the upper region. In the next step, the effect should be taken into account to obtain more realistic H{sup 0} distribution.

  5. Analysis of average density difference effect in a new two-lane lattice model

    Science.gov (United States)

    Zhang, Geng; Sun, Di-Hua; Zhao, Min; Liu, Wei-Ning; Cheng, Sen-Lin

    2015-11-01

    A new lattice model is proposed by taking the average density difference effect into account for two-lane traffic system according to Transportation Cyber-physical Systems. The influence of average density difference effect on the stability of traffic flow is investigated through linear stability theory and nonlinear reductive perturbation method. The linear analysis results reveal that the unstable region would be reduced by considering the average density difference effect. The nonlinear kink-antikink soliton solution derived from the mKdV equation is analyzed to describe the properties of traffic jamming transition near the critical point. Numerical simulations confirm the analytical results showing that traffic jam can be suppressed efficiently by considering the average density difference effect for two-lane traffic system.

  6. Genetic analysis of male reproductive success in relation to density in the zebrafish, Danio rerio

    Directory of Open Access Journals (Sweden)

    Jordan William C

    2006-04-01

    Full Text Available Abstract Background We used behavioural and genetic data to investigate the effects of density on male reproductive success in the zebrafish, Danio rerio. Based on previous measurements of aggression and courtship behaviour by territorial males, we predicted that they would sire more offspring than non-territorial males. Results Microsatellite analysis of paternity showed that at low densities territorial males had higher reproductive success than non-territorial males. However, at high density territorial males were no more successful than non-territorials and the sex difference in the opportunity for sexual selection, based on the parameter Imates, was low. Conclusion Male zebrafish exhibit two distinct mating tactics; territoriality and active pursuit of females. Male reproductive success is density dependent and the opportunity for sexual selection appears to be weak in this species.

  7. Effects of subsoil bulk density on root growth and soil enzyme activities during the growth of corn (Zea mays L.)%不同土层容重对玉米根系生长及土壤酶活性的影响

    Institute of Scientific and Technical Information of China (English)

    王群; 赵亚丽; 张学林; 张永恩; 李潮海

    2012-01-01

    The two-year pool-culture and barrel-culture experiments were conducted to study the impacts of subsoil bulk/density on root lenght, root dry weight, soil enzyme activities and yield in corn field on a sandy loam soil at the Experimental Farm of Henan Agricultural University. The results showed that the dynamic changes of root length, root dry weight, soil catalase, invertase, protease, urease, alkaline phosphatase activities and yields were single curve during the growth of corn, and the maximum values of these parameters occurred at the corn silking stage. Root length, root dry weight, yield and its components decreased with increaseing soil bulk density. These enzyme activities decreased with the increasing of both soil bulk density and soil depth. The higher the soil bulk density was the less active the soil enzyme activities were all soil enzyme activities were significantly different among soil bulk densities in the same soil layer, and they were also affected by soil bulk density in the adjacent layers. The bigger the soil bulk density of adjacent layers was the more significant the decrease was. The effect of subsoil bulk density on soil enzyme was more apparant from jointing stage to maturity.%采用微区池栽和桶栽试验,研究了下层(20~40 cm,40 ~ 60 cm)土壤容重改变后,玉米根系生长、产量及生育期间土壤过氧化氢酶、转化酶、蛋白酶、脲酶和碱性磷酸酶活性动态变化规律及其与微生物活性的相关性.结果表明,在玉米生育期内,玉米单株根长度和根干重、土壤过氧化氢酶、转化酶、蛋白酶、脲酶和碱性磷酸酶活性呈单峰曲线,最高值均出现在吐丝期;且随着下层土壤容重增加呈递减趋势.各土层酶活性均随着土层的加深和本土层容重的增大而降低,同时也随着相邻土层容重的增大其降幅加剧;玉米穗粒数、粒重和产量也随着土壤容重的增加而降低.玉米生长期间,土壤酶活性变化受下层

  8. Topological analysis of electron density and the electrostatic properties of isoniazid: an experimental and theoretical study.

    Science.gov (United States)

    Rajalakshmi, Gnanasekaran; Hathwar, Venkatesha R; Kumaradhas, Poomani

    2014-04-01

    Isoniazid (isonicotinohydrazide) is an important first-line antitubercular drug that targets the InhA enzyme which synthesizes the critical component of the mycobacterial cell wall. An experimental charge-density analysis of isoniazid has been performed to understand its structural and electronic properties in the solid state. A high-resolution single-crystal X-ray intensity data has been collected at 90 K. An aspherical multipole refinement was carried out to explore the topological and electrostatic properties of the isoniazid molecule. The experimental results were compared with the theoretical charge-density calculations performed using CRYSTAL09 with the B3LYP/6-31G** method. A topological analysis of the electron density reveals that the Laplacian of electron density of the N-N bond is significantly less negative, which indicates that the charges at the b.c.p. (bond-critical point) of the bond are least accumulated, and so the bond is considered to be weak. As expected, a strong negative electrostatic potential region is present in the vicinity of the O1, N1 and N3 atoms, which are the reactive locations of the molecule. The C-H···N, C-H···O and N-H···N types of intermolecular hydrogen-bonding interactions stabilize the crystal structure. The topological analysis of the electron density on hydrogen bonding shows the strength of intermolecular interactions.

  9. Thermodynamic analysis of energy density in pressure retarded osmosis: The impact of solution volumes and costs

    Energy Technology Data Exchange (ETDEWEB)

    Reimund, Kevin K. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Chemical and Biomolecular Engineering; McCutcheon, Jeffrey R. [Univ. of Connecticut, Storrs, CT (United States). Dept. of Chemical and Biomolecular Engineering; Wilson, Aaron D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    A general method was developed for estimating the volumetric energy efficiency of pressure retarded osmosis via pressure-volume analysis of a membrane process. The resulting model requires only the osmotic pressure, π, and mass fraction, w, of water in the concentrated and dilute feed solutions to estimate the maximum achievable specific energy density, uu, as a function of operating pressure. The model is independent of any membrane or module properties. This method utilizes equilibrium analysis to specify the volumetric mixing fraction of concentrated and dilute solution as a function of operating pressure, and provides results for the total volumetric energy density of similar order to more complex models for the mixing of seawater and riverwater. Within the framework of this analysis, the total volumetric energy density is maximized, for an idealized case, when the operating pressure is π/(1+√w⁻¹), which is lower than the maximum power density operating pressure, Δπ/2, derived elsewhere, and is a function of the solute osmotic pressure at a given mass fraction. It was also found that a minimum 1.45 kmol of ideal solute is required to produce 1 kWh of energy while a system operating at “maximum power density operating pressure” requires at least 2.9 kmol. Utilizing this methodology, it is possible to examine the effects of volumetric solution cost, operation of a module at various pressure, and operation of a constant pressure module with various feed.

  10. Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

    Energy Technology Data Exchange (ETDEWEB)

    Word, J Q; Ward, J A; Woodruff, D L

    1990-09-01

    The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae to the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs.

  11. Optimum element density studies for finite-element thermal analysis of hypersonic aircraft structures

    Science.gov (United States)

    Ko, William L.; Olona, Timothy; Muramoto, Kyle M.

    1990-01-01

    Different finite element models previously set up for thermal analysis of the space shuttle orbiter structure are discussed and their shortcomings identified. Element density criteria are established for the finite element thermal modelings of space shuttle orbiter-type large, hypersonic aircraft structures. These criteria are based on rigorous studies on solution accuracies using different finite element models having different element densities set up for one cell of the orbiter wing. Also, a method for optimization of the transient thermal analysis computer central processing unit (CPU) time is discussed. Based on the newly established element density criteria, the orbiter wing midspan segment was modeled for the examination of thermal analysis solution accuracies and the extent of computation CPU time requirements. The results showed that the distributions of the structural temperatures and the thermal stresses obtained from this wing segment model were satisfactory and the computation CPU time was at the acceptable level. The studies offered the hope that modeling the large, hypersonic aircraft structures using high-density elements for transient thermal analysis is possible if a CPU optimization technique was used.

  12. High-density EEG coherence analysis using functional units applied to mental fatigue

    NARCIS (Netherlands)

    Caat, Michael ten; Lorist, Monicque M.; Bezdan, Eniko; Roerdink, Jos B.T.M.; Maurits, Natasha M.

    2008-01-01

    Electroencephalography (EEG) coherence provides a quantitative measure of functional brain connectivity which is calculated between pairs of signals as a function of frequency. Without hypotheses, traditional coherence analysis would be cumbersome for high-density EEG which employs a large number of

  13. Charge Density Analysis and Transport Properties of TTF Based Molecular Nanowires: A DFT Approach

    Directory of Open Access Journals (Sweden)

    Karuppannan Selvaraju

    2015-01-01

    Full Text Available The present study has been performed to understand the charge density distribution and the electrical characteristics of Au and thiol substituted tetrathiafulvalene (TTF based molecular nanowire. A quantum chemical calculation has been carried out using DFT method (B3LYP with the LANL2DZ basis set under various applied electric fields (EFs. The bond topological analysis characterizes the terminal Au–S and S–C bonds as well as all the bonds of central TTF unit of the molecule. The variation of electron density and Laplacian of electron density at the bond critical point of bonds for zero and different applied fields reveal the electron density distribution of the molecule. The molecular conformation, the variation of atomic charges and energy density distribution of the molecule have been analyzed for the various levels of applied EFs. The HOMO-LUMO gap calculated from quantum chemical calculations has been compared with the value calculated from the density of states. The variation of dipole moment due to the polarization effect and the I-V characteristics of the molecule for the various applied EFs have been well discussed.

  14. Field spatial and temporal patterns of soil water content and bulk density changes Padrões espacial e temporal de mudanças da umidade e densidade do solo no campo

    Directory of Open Access Journals (Sweden)

    Luís Carlos Timm

    2006-02-01

    Full Text Available Soil water content (theta and bulk density (rhos greatly influence important soil and plant processes, such as water movement, soil compaction, soil aeration, and plant root system development. Spatial and temporal variability of theta and rhos during different periods of the year and different phases of crops are of fundamental interest. This work involves the characterization of spatial and temporal patterns of theta and rhos during different climatic periods of year, aiming to verify whether there are significant temporal changes in rhos at the soil surface layer when submitted to wetting and drying cycles. The field experiment was carried out in a coffee plantation, Rhodic Kandiudalf soil, clayey texture. Using a neutron/gamma surface probe, theta and rhos were measured meter by meter along a 200 m spatial transect, along an interrow contour line. During the wet period there was no difference of spatial patterns of theta while during the dry period differences were observed, and can be associated to precipitation events. It was also observed that there are rhos temporal changes at the soil surface along the studied period as a consequence of the in situ wetting and drying cycles.Umidade (teta e densidade do solo (ros influenciam importantes processos no solo e planta tais como: movimento de água, compactação do solo, aeração do solo e desenvolvimento radicular. Baseado neste fato, questões referentes à variabilidade espacial e temporal de teta e ros para diferentes períodos do ano e diferentes fases de desenvolvimento da cultura do café tornam-se de extremo interesse. Este trabalho teve como objetivo caracterizar padrões espaciais e temporais de teta e ros durante diferentes períodos do ano e verificar se existem mudanças temporais significativas de ros na superfície do solo quando submetida a ciclos de umedecimento/secagem. O experimento foi conduzido em campo cultivado com café em um solo classificado como Nitossolo Vermelho

  15. Cluster analysis of the organic peaks in bulk mass spectra obtained during the 2002 New England Air Quality Study with an Aerodyne aerosol mass spectrometer

    Directory of Open Access Journals (Sweden)

    C. Marcolli

    2006-06-01

    Full Text Available We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS bulk mass spectral dataset collected aboard the NOAA research vessel Ronald H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter most probably originating from both, anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent as much as 5 µg/m3 organic aerosol mass – 17% of the total organic mass – that can be attributed to biogenic sources. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

  16. Cluster Analysis of the Organic Peaks in Bulk Mass Spectra Obtained During the 2002 New England Air Quality Study with an Aerodyne Aerosol Mass Spectrometer

    Directory of Open Access Journals (Sweden)

    C. Marcolli

    2006-01-01

    Full Text Available We applied hierarchical cluster analysis to an Aerodyne aerosol mass spectrometer (AMS bulk mass spectral dataset collected aboard the NOAA research vessel R. H. Brown during the 2002 New England Air Quality Study off the east coast of the United States. Emphasizing the organic peaks, the cluster analysis yielded a series of categories that are distinguishable with respect to their mass spectra and their occurrence as a function of time. The differences between the categories mainly arise from relative intensity changes rather than from the presence or absence of specific peaks. The most frequent category exhibits a strong signal at m/z 44 and represents oxidized organic matter probably originating from both anthropogenic as well as biogenic sources. On the basis of spectral and trace gas correlations, the second most common category with strong signals at m/z 29, 43, and 44 contains contributions from isoprene oxidation products. The third through the fifth most common categories have peak patterns characteristic of monoterpene oxidation products and were most frequently observed when air masses from monoterpene rich regions were sampled. Taken together, the second through the fifth most common categories represent on average 17% of the total organic mass that stems likely from biogenic sources during the ship's cruise. These numbers have to be viewed as lower limits since the most common category was attributed to anthropogenic sources for this calculation. The cluster analysis was also very effective in identifying a few contaminated mass spectra that were not removed during pre-processing. This study demonstrates that hierarchical clustering is a useful tool to analyze the complex patterns of the organic peaks in bulk aerosol mass spectra from a field study.

  17. An Independent Component Analysis Algorithm through Solving Gradient Equation Combined with Kernel Density Estimation

    Institute of Scientific and Technical Information of China (English)

    XUE Yun-feng; WANG Yu-jia; YANG Jie

    2009-01-01

    A new algorithm for linear instantaneous independent component analysis is proposed based on max-imizing the log-likelihood contrast function which can be changed into a gradient equation. An iterative method is introduced to solve this equation efficiently. The unknown probability density functions as well as their first and second derivatives in the gradient equation are estimated by kernel density method. Computer simulations on artificially generated signals and gray scale natural scene images confirm the efficiency and accuracy of the proposed algorithm.

  18. Transport analysis of high radiation and high density plasmas in the ASDEX Upgrade tokamak

    Directory of Open Access Journals (Sweden)

    Casali L.

    2014-01-01

    Full Text Available Future fusion reactors, foreseen in the “European road map” such as DEMO, will operate under more demanding conditions compared to present devices. They will require high divertor and core radiation by impurity seeding to reduce heat loads on divertor target plates. In addition, DEMO will have to work at high core densities to reach adequate fusion performance. The performance of fusion reactors depends on three essential parameters: temperature, density and energy confinement time. The latter characterizes the loss rate due to both radiation and transport processes. The DEMO foreseen scenarios described above were not investigated so far, but are now addressed at the ASDEX Upgrade tokamak. In this work we present the transport analysis of such scenarios. Plasma with high radiation by impurity seeding: transport analysis taking into account the radiation distribution shows no change in transport during impurity seeding. The observed confinement improvement is an effect of higher pedestal temperatures which extend to the core via stiffness. A non coronal radiation model was developed and compared to the bolometric measurements in order to provide a reliable radiation profile for transport calculations. High density plasmas with pellets: the analysis of kinetic profiles reveals a transient phase at the start of the pellet fuelling due to a slower density build up compared to the temperature decrease. The low particle diffusion can explain the confinement behaviour.

  19. Occurrence of enterotoxin genes and macrorestriction analysis of Staphylococcus aureus isolated from bovine mastitis and bulk-tank milk samples in Italy. An epidemiological study

    Directory of Open Access Journals (Sweden)

    Roberto Rosmini

    2010-01-01

    Full Text Available The goal of the study was to genotypically compare S. aureus isolates from mastitis milk and raw milk to identify therelation between strains and to assess the enterotoxigenicity of the isolates. Eighty-three Staphylococcus aureus isolatesrecovered from cows and bulk tank milk of five farms in northern Italy were compared genotypically. The genes for theenterotoxins A, D, G and I, but not for B, C, E and H and the toxic shock syndrome toxin 1 (TSST-1, were detected byPCR amplification. Macrorestriction analysis with the restrictions enzyme SmaI revealed 14 pulsed-field gel electrophoresispatterns. These were in part different from each other only in a few fragments and thus displayed a closeclonal relation. The results of the present investigation showed that identical or closely related clones seemed to beresponsible for the cases of bovine mastitis in the farms investigated and partly responsible for contamination of bulktank milk.

  20. Large area bulk superconductors

    Science.gov (United States)

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  1. Analysis of the IMAGE RPI electron density data and CHAMP plasmasphere electron density reconstructions with focus on plasmasphere modelling

    Science.gov (United States)

    Gerzen, T.; Feltens, J.; Jakowski, N.; Galkin, I.; Reinisch, B.; Zandbergen, R.

    2016-09-01

    The electron density of the topside ionosphere and the plasmasphere contributes essentially to the overall Total Electron Content (TEC) budget affecting Global Navigation Satellite Systems (GNSS) signals. The plasmasphere can cause half or even more of the GNSS range error budget due to ionospheric propagation errors. This paper presents a comparative study of different plasmasphere and topside ionosphere data aiming at establishing an appropriate database for plasmasphere modelling. We analyze electron density profiles along the geomagnetic field lines derived from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite/Radio Plasma Imager (RPI) records of remote plasma sounding with radio waves. We compare these RPI profiles with 2D reconstructions of the topside ionosphere and plasmasphere electron density derived from GNSS based TEC measurements onboard the Challenging Minisatellite Payload (CHAMP) satellite. Most of the coincidences between IMAGE profiles and CHAMP reconstructions are detected in the region with L-shell between 2 and 5. In general the CHAMP reconstructed electron densities are below the IMAGE profile densities, with median of the CHAMP minus IMAGE residuals around -588 cm-3. Additionally, a comparison is made with electron densities derived from passive radio wave RPI measurements onboard the IMAGE satellite. Over the available 2001-2005 period of IMAGE measurements, the considered combined data from the active and passive RPI operations cover the region within a latitude range of ±60°N, all longitudes, and an L-shell ranging from 1.2 to 15. In the coincidence regions (mainly 2 ⩽ L ⩽ 4), we check the agreement between available active and passive RPI data. The comparison shows that the measurements are well correlated, with a median residual of ∼52 cm-3. The RMS and STD values of the relative residuals are around 22% and 21% respectively. In summary, the results encourage the application of IMAGE RPI data for

  2. Bulk Superconductors in Mobile Application

    Science.gov (United States)

    Werfel, F. N.; Delor, U. Floegel-; Rothfeld, R.; Riedel, T.; Wippich, D.; Goebel, B.; Schirrmeister, P.

    We investigate and review concepts of multi - seeded REBCO bulk superconductors in mobile application. ATZ's compact HTS bulk magnets can trap routinely 1 T@77 K. Except of magnetization, flux creep and hysteresis, industrial - like properties as compactness, power density, and robustness are of major device interest if mobility and light-weight construction is in focus. For mobile application in levitated trains or demonstrator magnets we examine the performance of on-board cryogenics either by LN2 or cryo-cooler application. The mechanical, electric and thermodynamical requirements of compact vacuum cryostats for Maglev train operation were studied systematically. More than 30 units are manufactured and tested. The attractive load to weight ratio is more than 10 and favours group module device constructions up to 5 t load on permanent magnet (PM) track. A transportable and compact YBCO bulk magnet cooled with in-situ 4 Watt Stirling cryo-cooler for 50 - 80 K operation is investigated. Low cooling power and effective HTS cold mass drives the system construction to a minimum - thermal loss and light-weight design.

  3. Relativistic analysis of nuclear ground state densities at 135 to 200 MeV

    Indian Academy of Sciences (India)

    M A Suhail; N Neeloffer; Z A Khan

    2005-12-01

    A relativistic analysis of p + 40Ca elastic scattering with different nuclear ground state target densities at 135 to 200 MeV is presented in this paper. It is found that the IGO densities are more consistent in reproducing the data over the energy range considered here. The reproduction of spin-rotation-function data with the simultaneous fitting of differential cross-section and analyzing power, and the appearance of wine-bottle-bottom shaped Re eff() in the transition energy region, sensitively depends on the input nuclear ground state densities and are not solely the relativistic characteristic signatures. We also found that the wine-bottle-bottom shaped Re eff() is preferred by the spin observables in the transition energy region (i.e. 181 MeV to 200 MeV).

  4. Thermodynamic, energy efficiency, and power density analysis of reverse electrodialysis power generation with natural salinity gradients.

    Science.gov (United States)

    Yip, Ngai Yin; Vermaas, David A; Nijmeijer, Kitty; Elimelech, Menachem

    2014-05-06

    Reverse electrodialysis (RED) can harness the Gibbs free energy of mixing when fresh river water flows into the sea for sustainable power generation. In this study, we carry out a thermodynamic and energy efficiency analysis of RED power generation, and assess the membrane power density. First, we present a reversible thermodynamic model for RED and verify that the theoretical maximum extractable work in a reversible RED process is identical to the Gibbs free energy of mixing. Work extraction in an irreversible process with maximized power density using a constant-resistance load is then examined to assess the energy conversion efficiency and power density. With equal volumes of seawater and river water, energy conversion efficiency of ∼ 33-44% can be obtained in RED, while the rest is lost through dissipation in the internal resistance of the ion-exchange membrane stack. We show that imperfections in the selectivity of typical ion exchange membranes (namely, co-ion transport, osmosis, and electro-osmosis) can detrimentally lower efficiency by up to 26%, with co-ion leakage being the dominant effect. Further inspection of the power density profile during RED revealed inherent ineffectiveness toward the end of the process. By judicious early discontinuation of the controlled mixing process, the overall power density performance can be considerably enhanced by up to 7-fold, without significant compromise to the energy efficiency. Additionally, membrane resistance was found to be an important factor in determining the power densities attainable. Lastly, the performance of an RED stack was examined for different membrane conductivities and intermembrane distances simulating high performance membranes and stack design. By thoughtful selection of the operating parameters, an efficiency of ∼ 37% and an overall gross power density of 3.5 W/m(2) represent the maximum performance that can potentially be achieved in a seawater-river water RED system with low

  5. 不同装烟密度对散叶密集烘烤烟叶品质及能耗的影响%Effect of Different Loading Density of Flue Bulk Curing by Loose-leaf Stacking on Quality of Tobacco Leaves and Energy Consumption

    Institute of Scientific and Technical Information of China (English)

    卢贤仁; 谢已书; 李国彬; 姜均

    2011-01-01

    Effect of 3 fresh tobacco loading densities(55~60, 60~65, and 65~70kg/m2 from low to high density) on tobacco leaves' quality and energy consumption were studied in the bulk curing barn to explore the most suitable loading density of tobacco by loose-leaf stacking. The results showed that compared with low density both mid to high density of loading density, especially mid density could improve the economic character of tobacco, harmonize the chemical composition, and improve the quality of tobacco leaves. Increasing the loading density could reduce the energy consumption cost, total cost of mid density reduced by more than 8%, and high density reduced by more than 14% compared with low density. In conclusion, the fresh tobacco leaves loading density of 60~65 kg/m2could be optimum in bulk curing barn by loose-leaf stacking.%为探索散叶堆放最佳装烟密度范围,研究了装鲜烟低(55~60kg/m2)、中(60~65kg/m2)、高(65~70 kg/m2)3种装烟密度对烟叶的品质和能耗效果的影响.结果表明:与低密度散叶堆放装烟相比,中密度和高密度装烟均可提高烟叶经济性状,协调烟叶化学成分和改善烟叶品质,以中密度处理效果较为明显.增加装烟密度均可以降低烟叶的能耗成本,与低密度处理相比,中密度处理的总成本降低8%以上,高密度降低14%以上.综合认为,散叶堆放装鲜烟密度以60~65kg/m2最佳.

  6. Neutron Densities from a Global Analysis of Medium Energy Proton Nucleus Elastic Scattering

    CERN Document Server

    Clark, B C; Kerr, L J

    2003-01-01

    A new method for extracting neutron densities from intermediate energy elastic proton-nucleus scattering observables uses a global Dirac phenomenological (DP) approach based on the Relativistic Impulse Approximation (RIA). Data sets for Ca40, Ca48 and Pb208 in the energy range from 500 MeV to 1040 MeV are considered. The global fits are successful in reproducing the data and in predicting data sets not included in the analysis. Using this global approach, energy independent neutron densities are obtained. The vector point proton density distribution is determined from the empirical charge density after unfolding the proton form factor. The other densities are parametrized. The RMS neutron radius, R_n and the neutron skin thickness S_n obtained from the global fits using the most conservative errors are given as follows: for Ca40 R_n is (3.325 +/- 0.025) fm and S_n (-0.044 +/- 0.036) fm; for Ca48 R_n is (3.463 +/- 0.042) fm and S_n (0.103 +/- 0.045) fm; and for Pb208 R_n is (5.551 +/- 0.038) and S_n (0.116 +/-...

  7. An analysis of the evolving comoving number density of galaxies in hydrodynamical simulations

    CERN Document Server

    Torrey, Paul; Machado, Francisco; Griffen, Brendan; Nelson, Dylan; Rodriguez-Gomez, Vicente; McKinnon, Ryan; Pillepich, Annalisa; Ma, Chung-Pei; Vogelsberger, Mark; Springel, Volker; Hernquist, Lars

    2015-01-01

    The cumulative comoving number-density of galaxies as a function of stellar mass or central velocity dispersion is commonly used to link galaxy populations across different epochs. By assuming that galaxies preserve their number-density in time, one can infer the evolution of their properties, such as masses, sizes, and morphologies. However, this assumption does not hold in the presence of galaxy mergers or when rank ordering is broken owing to variable stellar growth rates. We present an analysis of the evolving comoving number density of galaxy populations found in the Illustris cosmological hydrodynamical simulation focused on the redshift range $0\\leq z \\leq 3$. Our primary results are as follows: 1) The inferred average stellar mass evolution obtained via a constant comoving number density assumption is systematically biased compared to the merger tree results at the factor of $\\sim$2(4) level when tracking galaxies from redshift $z=0$ out to redshift $z=2(3)$; 2) The median number density evolution for...

  8. Analysis of geometric and electrochemical characteristics of lithium cobalt oxide electrode with different packing densities

    Science.gov (United States)

    Lim, Cheolwoong; Yan, Bo; Kang, Huixiao; Song, Zhibin; Lee, Wen Chao; De Andrade, Vincent; De Carlo, Francesco; Yin, Leilei; Kim, Youngsik; Zhu, Likun

    2016-10-01

    To investigate geometric and electrochemical characteristics of Li ion battery electrode with different packing densities, lithium cobalt oxide (LiCoO2) cathode electrodes were fabricated from a 94:3:3 (wt%) mixture of LiCoO2, polymeric binder, and super-P carbon black and calendered to different densities. A synchrotron X-ray nano-computed tomography system with a spatial resolution of 58.2 nm at the Advanced Photon Source of the Argonne National Laboratory was employed to obtain three dimensional morphology data of the electrodes. The morphology data were quantitatively analyzed to characterize their geometric properties, such as porosity, tortuosity, specific surface area, and pore size distribution. The geometric and electrochemical analysis reveal that high packing density electrodes have smaller average pore size and narrower pore size distribution, which improves the electrical contact between carbon-binder matrix and LiCoO2 particles. The better contact improves the capacity and rate capability by reducing the possibility of electrically isolated LiCoO2 particles and increasing the electrochemically active area. The results show that increase of packing density results in higher tortuosity, but electrochemically active area is more crucial to cell performance than tortuosity at up to 3.6 g/cm3 packing density and 4 C rate.

  9. Spectral analysis, vibrational assignments, NBO analysis, NMR, UV-Vis, hyperpolarizability analysis of 2-aminofluorene by density functional theory.

    Science.gov (United States)

    Jone Pradeepa, S; Sundaraganesan, N

    2014-05-05

    In this present investigation, the collective experimental and theoretical study on molecular structure, vibrational analysis and NBO analysis has been reported for 2-aminofluorene. FT-IR spectrum was recorded in the range 4000-400 cm(-1). FT-Raman spectrum was recorded in the range 4000-50 cm(-1). The molecular geometry, vibrational spectra, and natural bond orbital analysis (NBO) were calculated for 2-aminofluorene using Density Functional Theory (DFT) based on B3LYP/6-31G(d,p) model chemistry. (13)C and (1)H NMR chemical shifts of 2-aminofluorene were calculated using GIAO method. The computed vibrational and NMR spectra were compared with the experimental results. The total energy distribution (TED) was derived to deepen the understanding of different modes of vibrations contributed by respective wavenumber. The experimental UV-Vis spectra was recorded in the region of 400-200 nm and correlated with simulated spectra by suitably solvated B3LYP/6-31G(d,p) model. The HOMO-LUMO energies were measured with time dependent DFT approach. The nonlinearity of the title compound was confirmed by hyperpolarizabilty examination. Using theoretical calculation Molecular Electrostatic Potential (MEP) was investigated.

  10. An analysis of the relationship between bulk tank milk quality and wash water quality on dairy farms in Ontario, Canada.

    Science.gov (United States)

    Perkins, N R; Kelton, D F; Hand, K J; MacNaughton, G; Berke, O; Leslie, K E

    2009-08-01

    The objective of this study was to identify regions at high risk for bacterial water or milk contamination, as well as risk factors associated with high bacteria counts in raw milk in Ontario, Canada. Between 2003 and 2004, the Dairy Farmers of Ontario (DFO) tested water samples from 5,421 farms in Ontario for the presence of Escherichia coli and coliforms. The water samples were collected as "point-of-use" samples, meaning that each sample was taken from a tap or water hose in the milk house as soon as the water was turned on. Routine, monthly raw milk bacterial counts were determined by DFO using BactoScan (Foss, Hillerød, Denmark). BactoScan data were retrieved from DFO for all of the farms with water test results. The prevalence of samples with E. coli and coliforms in water and elevated bacteria counts in raw milk was 13.6, 53.8, and 2.8%, respectively. The spatial analysis, using a scan statistic, revealed 1 coliform and 3 E. coli clusters of contaminated water, but no clusters of elevated milk bacteria counts in raw milk in southern Ontario. The coliform water contamination cluster was the largest, with a radius of approximately 200 km. Regression analysis indicated that risk factors associated with the occurrence of high levels of bacteria in raw milk were elevated average monthly somatic cell count, increased total milk production, cooler seasons of the year, and the presence of E. coli in wash water.

  11. Combining SNP discovery from next-generation sequencing data with bulked segregant analysis (BSA to fine-map genes in polyploid wheat

    Directory of Open Access Journals (Sweden)

    Trick Martin

    2012-01-01

    Full Text Available Abstract Background Next generation sequencing (NGS technologies are providing new ways to accelerate fine-mapping and gene isolation in many species. To date, the majority of these efforts have focused on diploid organisms with readily available whole genome sequence information. In this study, as a proof of concept, we tested the use of NGS for SNP discovery in tetraploid wheat lines differing for the previously cloned grain protein content (GPC gene GPC-B1. Bulked segregant analysis (BSA was used to define a subset of putative SNPs within the candidate gene region, which were then used to fine-map GPC-B1. Results We used Illumina paired end technology to sequence mRNA (RNAseq from near isogenic lines differing across a ~30-cM interval including the GPC-B1 locus. After discriminating for SNPs between the two homoeologous wheat genomes and additional quality filtering, we identified inter-varietal SNPs in wheat unigenes between the parental lines. The relative frequency of these SNPs was examined by RNAseq in two bulked samples made up of homozygous recombinant lines differing for their GPC phenotype. SNPs that were enriched at least 3-fold in the corresponding pool (6.5% of all SNPs were further evaluated. Marker assays were designed for a subset of the enriched SNPs and mapped using DNA from individuals of each bulk. Thirty nine new SNP markers, corresponding to 67% of the validated SNPs, mapped across a 12.2-cM interval including GPC-B1. This translated to 1 SNP marker per 0.31 cM defining the GPC-B1 gene to within 13-18 genes in syntenic cereal genomes and to a 0.4 cM interval in wheat. Conclusions This study exemplifies the use of RNAseq for SNP discovery in polyploid species and supports the use of BSA as an effective way to target SNPs to specific genetic intervals to fine-map genes in unsequenced genomes.

  12. Density of very small meteoroids

    Science.gov (United States)

    Kikwaya Eluo, Jean-Baptiste

    2015-08-01

    Knowing the density of meteoroids helps to determine the physical structure and gives insight into the composition of their parent bodies. The density of meteoroids can provide clues to their origins, whether cometary or asteroidal. Density helps also to characterize the risk meteoroids may pose to artificial satellites.Ceplecha (1968) calculated the density of small meteoroids based on a parameter KB (meteoroid beginning height) and classified them in four categories (A,B,C,D) with densities going from 2700 to 180 kgm-3.Babadzhanov(2002) applied a model based on quasi-continuous fragmentation (QCF) on 413 photographic Super-Schmidt meteors by solely fitting their light curves. Their densities range from 400 to 7800 kgm-3. Bellot Rubio et al. (2002) analyzed the same 413 photographic meteors assuming the single body theory based on meteoroid dynamical properties and found densities ranging from 400 to 4800 kgm-3. A thermal erosion model was used by Borovicka et al. (2007) to analyze, simultaneously, the observed decelerations and light curves of six Draconid meteors. The density was found to be 300 kgm-3, consistent with the fact that the Draconid meteors are porous aggregates of grains associated with the Jupiter-family-comet 21P/Giacobini-Zinner (Jacchia, L.G., 1950).We used the Campbell-Brown and Koschny (2004) model of meteoroid ablation to determine the density of faint meteoroids from the analysis of both observed decelerations and light curves of meteoroids (Kikwaya et al., 2009; Kikwaya et al., 2011). Our work was based on a collection of six and ninety-two sporadic meteors. The grain masses used in the modeling ranged from 10-12 Kg to 10-9 Kg. We computed the orbit of each meteoroid and determined its Tisserand parameter. We found that meteoroids with asteroidal orbits have bulk densities ranging from 3000-5000 kgm-3. Meteoroids consistent with HTC/NIC parents have bulk densities from 400 kgm-3 to 1600 kg m-3. JFC meteoroids were found to have surprisingly

  13. Combining Next Generation Sequencing with Bulked Segregant Analysis to Fine Map a Stem Moisture Locus in Sorghum (Sorghum bicolor L. Moench).

    Science.gov (United States)

    Han, Yucui; Lv, Peng; Hou, Shenglin; Li, Suying; Ji, Guisu; Ma, Xue; Du, Ruiheng; Liu, Guoqing

    2015-01-01

    Sorghum is one of the most promising bioenergy crops. Stem juice yield, together with stem sugar concentration, determines sugar yield in sweet sorghum. Bulked segregant analysis (BSA) is a gene mapping technique for identifying genomic regions containing genetic loci affecting a trait of interest that when combined with deep sequencing could effectively accelerate the gene mapping process. In this study, a dry stem sorghum landrace was characterized and the stem water controlling locus, qSW6, was fine mapped using QTL analysis and the combined BSA and deep sequencing technologies. Results showed that: (i) In sorghum variety Jiliang 2, stem water content was around 80% before flowering stage. It dropped to 75% during grain filling with little difference between different internodes. In landrace G21, stem water content keeps dropping after the flag leaf stage. The drop from 71% at flowering time progressed to 60% at grain filling time. Large differences exist between different internodes with the lowest (51%) at the 7th and 8th internodes at dough stage. (ii) A quantitative trait locus (QTL) controlling stem water content mapped on chromosome 6 between SSR markers Ch6-2 and gpsb069 explained about 34.7-56.9% of the phenotypic variation for the 5th to 10th internodes, respectively. (iii) BSA and deep sequencing analysis narrowed the associated region to 339 kb containing 38 putative genes. The results could help reveal molecular mechanisms underlying juice yield of sorghum and thus to improve total sugar yield.

  14. Analysis of homogeneity of 2D electron gas at decreasing of electron density

    OpenAIRE

    Sherstobitov, A. A.; Minkov, G. M.; Germanenko, A. V.; Rut, O. E.; Soldatov, I. V.; Zvonkov, B. N.

    2010-01-01

    We investigate the gate voltage dependence of capacitance of a system gate - 2D electron gas (C-Vg). The abrupt drop of capacitance at decreasing concentration was found. The possible reasons of this drop, namely inhomogeneity of electron density distribution and serial resistance of 2D electron gas are discussed. Simultaneous analysis of gate voltage dependences of capacitance and resistance has shown that in heavily doped 2D systems the main role in the drop of capacitance at decreasing con...

  15. Density analysis of the neutron structure factor and the determination of the pair potential of krypton

    Science.gov (United States)

    Barocchi, F.; Zoppi, M.; Egelstaff, P. A.

    1985-04-01

    We propose a method of analysis of the density behavior of the experimental neutron scattering structure factor which permits us to derive directly from the experimental results an ``experimental'' pair potential. We apply the method to the recent results of Teitsma and Egelstaff in krypton gas and derive a pair potential which is in good agreement with the empirical potential of Barker et al. Some discrepancies in the range 4

  16. Superconducting bulk magnets for magnetic levitation systems

    Science.gov (United States)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa 2Cu 3O 7- x and light rare-earth LREBa 2Cu 3O 7- x superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application. We investigated the possibility of using bulk magnets in the Maglev system, and examined flux-trapping characteristics of multi-superconducting bulks arranged in array.

  17. 散粮皮带通廊结构静态性能分析%Static Performance Analysis on Bulk Grain Belt Corridor Structure

    Institute of Scientific and Technical Information of China (English)

    王景起

    2016-01-01

    Belt corridor is a major bulk terminal equipment.Due to its long design life,bulky structure,maintenance complexity,especially harsh seaside working conditions,the corridor’s steel structure is susceptible to corrosion damage, which severely reduces the safety and reliability of the gallery structure.Taking bulk grain belt corridor device in Tianjin Harbour Second Stevedoring Co.,Ltd as the research subject,a finite element analysis model was established according to characteristics of the structure and condition of such equipment and in accordance with design drawings and actual corrosion damages.An in-depth study of the static performance of belt corridor structure was carried out,whichprovides a theoretical basis for the maintenance management scheme.%皮带通廊是散货码头的主要设备之一,由于该类设备的设计寿命较长,结构体积较大,维护节点多,特别是长期处在海边恶劣的工况条件下,其钢结构容易发生锈蚀损伤,严重降低了通廊结构及整套设施的安全可靠性。以天津港第二港埠有限公司散粮皮带通廊设备作为研究对象,根据该类设备的结构及工况特点,并依据设计图纸及实际锈蚀损伤情况,建立有限元分析模型,深入研究了皮带通廊结构的静态性能,为皮带通廊的维护方案提供了理论依据。

  18. Optimal Thermo-Structural Analysis for High Density Package Mounting on Build-up Board

    Science.gov (United States)

    Nakanishi, Tohru; Hase, Tomohiro

    The importance of the high density packaging technology and mounting technology on the printed wiring build-up board has been increased for the consumer electric products. On the other hand, the chance to use the build-up boards for mounting the high density packages has been increased. However, the understanding that the reliability of the solder connection depends on the structure of the package, the motherboard, and the material properties, is not very high. In this paper, the reliability for high density packaging, mounted on the build-up board, is assessed. The compact numerical analysis model for the reliability assessment is suggested and the most reliable packaging design with optimizing each of the parameters is reported. For introduction to the reliability assessment of the FCA attachment, ceramic and silicon are compared as the inter-poser with the parameter of the solder height. The verification of the numerical analysis results using tests on the actual hardware is also shown. And the established numerical analysis model is applied to the study of influence of the copper balance between the front side and the back side copper layers.

  19. MRSA: a density-equalizing mapping analysis of the global research architecture.

    Science.gov (United States)

    Addicks, Johann P; Uibel, Stefanie; Jensen, Anna-Maria; Bundschuh, Matthias; Klingelhoefer, Doris; Groneberg, David A

    2014-09-30

    Methicillin-resistant Staphylococcus aureus (MRSA) has evolved as an alarming public health thread due to its global spread as hospital and community pathogen. Despite this role, a scientometric analysis has not been performed yet. Therefore, the NewQIS platform was used to conduct a combined density-equalizing mapping and scientometric study. As database, the Web of Science was used, and all entries between 1961 and 2007 were analyzed. In total, 7671 entries were identified. Density equalizing mapping demonstrated a distortion of the world map for the benefit of the USA as leading country with a total output of 2374 publications, followed by the UK (1030) and Japan (862). Citation rate analysis revealed Portugal as leading country with a rate of 35.47 citations per article, followed by New Zealand and Denmark. Country cooperation network analyses showed 743 collaborations with US-UK being most frequent. Network citation analyses indicated the publications that arose from the cooperation of USA and France as well as USA and Japan as the most cited (75.36 and 74.55 citations per collaboration article, respectively). The present study provides the first combined density-equalizing mapping and scientometric analysis of MRSA research. It illustrates the global MRSA research architecture. It can be assumed that this highly relevant topic for public health will achieve even greater dimensions in the future.

  20. Principal component analysis of the CT density histogram to generate parametric response maps of COPD

    Science.gov (United States)

    Zha, N.; Capaldi, D. P. I.; Pike, D.; McCormack, D. G.; Cunningham, I. A.; Parraga, G.

    2015-03-01

    Pulmonary x-ray computed tomography (CT) may be used to characterize emphysema and airways disease in patients with chronic obstructive pulmonary disease (COPD). One analysis approach - parametric response mapping (PMR) utilizes registered inspiratory and expiratory CT image volumes and CT-density-histogram thresholds, but there is no consensus regarding the threshold values used, or their clinical meaning. Principal-component-analysis (PCA) of the CT density histogram can be exploited to quantify emphysema using data-driven CT-density-histogram thresholds. Thus, the objective of this proof-of-concept demonstration was to develop a PRM approach using PCA-derived thresholds in COPD patients and ex-smokers without airflow limitation. Methods: Fifteen COPD ex-smokers and 5 normal ex-smokers were evaluated. Thoracic CT images were also acquired at full inspiration and full expiration and these images were non-rigidly co-registered. PCA was performed for the CT density histograms, from which the components with the highest eigenvalues greater than one were summed. Since the values of the principal component curve correlate directly with the variability in the sample, the maximum and minimum points on the curve were used as threshold values for the PCA-adjusted PRM technique. Results: A significant correlation was determined between conventional and PCA-adjusted PRM with 3He MRI apparent diffusion coefficient (p<0.001), with CT RA950 (p<0.0001), as well as with 3He MRI ventilation defect percent, a measurement of both small airways disease (p=0.049 and p=0.06, respectively) and emphysema (p=0.02). Conclusions: PRM generated using PCA thresholds of the CT density histogram showed significant correlations with CT and 3He MRI measurements of emphysema, but not airways disease.

  1. Nongeneric dispersion of excitons in the bulk of WSe2

    Science.gov (United States)

    Schuster, R.; Wan, Y.; Knupfer, M.; Büchner, B.

    2016-08-01

    We combine electron energy-loss spectroscopy (EELS) and density functional theory (DFT) calculations to study the dispersion and effective mass of excitons in the bulk of WSe2. Our EELS data suggest substantial deviations from the generic quadratic momentum dependence along the Γ K direction. From the DFT-derived Kohn-Sham states we deduce the EELS response without the inclusion of particle-hole attraction to study the possible role of the single-particle band structure on the exciton behavior. Based on this analysis we argue in favor of a strongly momentum dependent particle-hole interaction in WSe2 and other group-VI-transition-metal dichalcogenides.

  2. Growth and chemical analysis of bulk Nd 2- xCe xCuO y single crystals

    Science.gov (United States)

    Zhigunov, D. I.; Shiryaev, S. V.; Kurnevich, L. A.; Kalanda, N. A.; Kurochkin, L. A.; Barilo, S. N.; Vashuk, V. V.; Smakhtin, L. A.

    1999-03-01

    Single crystals of Nd 2- xCe xCuO y (0< x<0.17) from a family of the electron-type superconductors have been grown using platinum crucibles by the top seeded solution growth technique. The structural quality of the crystals was examined by X-ray diffraction. The FWHM of the Bragg reflections for the best samples varies from 8 to 20 angular seconds. Full neutron activation analysis was carried out to determine the chemical composition of the as-grown crystals. Small cation stoichiometry deviations from ideal (NdCe)/Cu ratio are found as well as Pt substitution on the copper sublattice at a level up to 2 at% exists depending on growth conditions. The results of thermogravimetric measurements and further annealing of samples show that the problem of an oxygen reduction of large Nd 2- xCe xCuO y crystals is closely connected with inhomogeneity of anion distribution in the lattice possibly caused by non-optimal parameters for the reduction process and the level of impurities contamination. A three step reduction process which produces superconductivity with Tc˜19 K in single crystals thicker than 1 mm has been developed.

  3. A Validated New Gradient Stability-Indicating LC Method for the Analysis of Doripenem in Bulk and Injection Formulation

    Directory of Open Access Journals (Sweden)

    Singaram Kathirvel

    2013-01-01

    Full Text Available A sensitive, precise, specific, linear, and stability-indicating gradient HPLC method was developed for the estimation of doripenem in active pharmaceutical ingredient (API and in injectable preparations. Chromatographic separation was achieved on C18 stationary phase with a mobile phase gradient consisting of acetonitrile, methanol, and pH 5.2 phosphate buffer. The mobile phase flow rate was 0.8 mL/min, and the eluted compounds were monitored at 210 nm. The method is linear over the range of 0.335 to 76.129 µg/mL. The correlation coefficient was found to be 0.999. The numbers of theoretical plates and tailing factor for doripenem were 53021 and 0.9, respectively. Doripenem was subjected to the International Conference on Harmonization (ICH prescribed hydrolytic (acid, base, and neutral, oxidative, photolytic, and thermal stress conditions. Among all the above-mentioned conditions, the drug was found to be stable under photolytic degradation. Peak homogeneity data for doripenem in the chromatograms from the stressed samples obtained by use of the photodiode array detector demonstrated the specificity of the method for analysis of doripenem in presence of the degradation products. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, and robustness.

  4. Determination of bulk diffusion lengths for angle-lapped semiconductor material via the scanning electron microscope: A theoretical analysis

    Science.gov (United States)

    Vonroos, O.

    1978-01-01

    A standard procedure for the determination of the minority carrier diffusion length by means of a scanning electron microscope (SEM) consists in scanning across an angle-lapped surface of a P-N junction and measuring the resultant short circuit current I sub sc as a function of beam position. A detailed analysis of the I sub sc originating from this configuration is presented. It is found that, for a point source excitation, the I sub sc depends very simply on x, the variable distance between the surface and the junction edge. The expression for the I sub sc of a planar junction device is well known. If d, the constant distance between the plane of the surface of the semiconductor and the junction edge in the expression for the I of a planar junction is merely replaced by x, the variable distance of the corresponding angle-lapped junction, an expression results which is correct to within a small fraction of a percent as long as the angle between the surfaces, 2 theta sub 1, is smaller than 10 deg.

  5. Bulked Segregant Analysis to Detect QTL Related to Heat Tolerance in Rice(Oryza sativa L.)Using SSR Markers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gui-lian; CHEN Li-yun; XIAO Guo-ying; XIAO Ying-hui; CHEN Xin-bo; ZHANG Shun-tang

    2009-01-01

    The study was undertaken to assess the genetic effect of quantitative trait loci(QTLs)conferring heat tolerance at flowering stage in rice.A population consisting of 279 F2 individuals from the cross between 996,a heat tolerant cultivar and 4628,a heat-sensitive cultivar,was analyzed for their segregation pattern of the difference of seed set rate under optimal temperature condition and high temperature condition.The difference of seed set rate under optimal temperature condition and high temperature condition showed normal distribution,indicating the polygenic control over the trait.To identify main effect of QTL for heat tolerance,the parents were surveyed with 200 primer pairs of simple sequence repeats(SSR).The parental survey revealed 30% polymorphism between parents.In order to detect the main QTL association with heat tolerance,a strategy of combining the DNA pooling from selected segregants and genotyping was adopted.The association of putative markers identified based on DNA pooling from selected segregants was established by single marker analysis(SMA).The results of SMA revealed that SSR markers,RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively.accounted for 17 and 3% of the total variation respectively.The heat tolerance during flowering stage in rice was controlled by multiple gene.The SSR markers,RM3735 on chromosome 4 and RM3586 on chromosome 3 showed significant association with heat tolerance respectively,accounted for 17 and 3% of the total variation respectively.The two genetic loci,especially for RM3735 on chromosome 4,can be used in marker-assistant-selected method in heat tolerance breeding in rice.

  6. Analysis of quantum particle automata for solving the density classification problem

    Science.gov (United States)

    Yu, Tina; Ben-Av, Radel

    2015-04-01

    To advance our understanding of quantum cellular automata in problem solving through parallel and distributed computing, this research quantized the density classification problem and adopted the quantum particle automata (QPA) to solve the quantized problem. In order to solve this problem, the QPA needed a unitary operator to carry out the QPA evolution and a boundary partition to make the classification decisions. We designed a genetic algorithm (GA) to search for the unitary operators and the boundary partitions to classify the density of binary inputs with length 5. The GA was able to find more than one unitary operator that can transform the QPA in ways such that when the particle was measured, it was more likely to collapse to the basis states that were on the correct side of the boundary partition for the QPA to decide whether the binary input had majority density 0 or majority density 1. We analyzed these solutions and found that the QPA evolution dynamic was driven by a particular parameter of the unitary operator: A small gave the particle small mass hence fast evolution, while large had the opposite effect. While these results are encouraging, scaling these solutions for binary inputs of arbitrary length of requires additional analysis, which we will investigate in our future work.

  7. Electrochemical impedance spectroscopy analysis of porous silicon prepared by photo-electrochemical etching: current density effect

    Science.gov (United States)

    Husairi, F. S.; Rouhi, J.; Eswar, K. A.; Zainurul, A. Z.; Rusop, M.; Abdullah, S.

    2014-09-01

    Electrical impedance characteristics of porous silicon nanostructures (PSiNs) in frequency function were studied. PSiNs were prepared through photo-electrochemical etching method at various current densities (15-40 mA/cm2) and constant etching time. The atomic force microscope images of PSiNs show that pore diameter and roughness increase when current density increases to 35 mA/cm2. The surface roughness subsequently decreases because of continuous etching of pillars, and a second etching process occurs. Photoluminescence spectra show blue and red shift with increasing applied current density that is attributed to PSiNs size. Variations of electrical resistance and capacitance values of PSiNs were measured using electrochemical impedance spectroscopy analysis. These results indicate that PSiNs prepared at 20 mA/cm2 current density have uniform porous structures with a large number of pillars. Furthermore, this PSiNs structure influences large values of charge transfer resistance and double layer capacitance, indicating potential application in sensors.

  8. A Monte Carlo Library Least Square approach in the Neutron Inelastic-scattering and Thermal-capture Analysis (NISTA) process in bulk coal samples

    Science.gov (United States)

    Reyhancan, Iskender Atilla; Ebrahimi, Alborz; Çolak, Üner; Erduran, M. Nizamettin; Angin, Nergis

    2017-01-01

    A new Monte-Carlo Library Least Square (MCLLS) approach for treating non-linear radiation analysis problem in Neutron Inelastic-scattering and Thermal-capture Analysis (NISTA) was developed. 14 MeV neutrons were produced by a neutron generator via the 3H (2H , n) 4He reaction. The prompt gamma ray spectra from bulk samples of seven different materials were measured by a Bismuth Germanate (BGO) gamma detection system. Polyethylene was used as neutron moderator along with iron and lead as neutron and gamma ray shielding, respectively. The gamma detection system was equipped with a list mode data acquisition system which streams spectroscopy data directly to the computer, event-by-event. A GEANT4 simulation toolkit was used for generating the single-element libraries of all the elements of interest. These libraries were then used in a Linear Library Least Square (LLLS) approach with an unknown experimental sample spectrum to fit it with the calculated elemental libraries. GEANT4 simulation results were also used for the selection of the neutron shielding material.

  9. Fatigue Analysis of a Bulk Carrier based on CSR%基于共同规范的散货船疲劳分析

    Institute of Scientific and Technical Information of China (English)

    陈国建; 韩天宇

    2011-01-01

    Fatigue is one of the main reasons for ship hull damage. It is of great significance to increase structure fatigue life in the preliminary design phase. Combining the experience and feedback from ship building and operation, the structure fatigue analysis of a bulk carrier is carried out based on IACS’ Common Structure Rules (CSR). 2D longitudinal stiffener fatigue is analyzed; and fatigue analysis of the hull’s main supporting components is performed using 3D Finite Element Method to form a conclusion; key factors affecting the fatigue strength are also studied.%疲劳是船体损坏的主要因素之一,在设计建造阶段提高结构物疲劳寿命具有重要意义。结合船舶在建造和营运中的经验与反馈,以船级社共同规范为指导,对散货船船体结构的疲劳分析进行了探讨。分析了二维情况下的纵骨疲劳,同时利用三维有限元方法对船体主要支撑构件的疲劳强度进行了分析和总结,对影响疲劳强度的一些关键因素进行了讨论。

  10. Revised Thickness of the Lunar Crust from GRAIL Data: Implications for Lunar Bulk Composition

    Science.gov (United States)

    Taylor, G. Jeffrey; Wieczorek, Mark A.; Neumann, Gregory A.; Nimmo, Francis; Kiefer, Walter S.; Melosh, H. Jay; Phillips, Roger J.; Solomon, Sean C.; Andrews-Hanna, Jeffrey C.; Asmar, Sami W.; Konopliv, Alexander S.; Lemoine, Frank G.; Smith, David E.; Watkins, Michael W.; Williams, James G.; Zuber, Maria T.

    2013-01-01

    High-resolution gravity data from GRAIL have yielded new estimates of the bulk density and thickness of the lunar crust. The bulk density of the highlands crust is 2550 kg m-3. From a comparison with crustal composition measured remotely, this density implies a mean porosity of 12%. With this bulk density and constraints from the Apollo seismic experiment, the average global crustal thickness is found to lie between 34 and 43 km, a value 10 to 20 km less than several previous estimates. Crustal thickness is a central parameter in estimating bulk lunar composition. Estimates of the concentrations of refractory elements in the Moon from heat flow, remote sensing and sample data, and geophysical data fall into two categories: those with refractory element abundances enriched by 50% or more relative to Earth, and those with abundances the same as Earth. Settling this issue has implications for processes operating during lunar formation. The crustal thickness resulting from analysis of GRAIL data is less than several previous estimates. We show here that a refractory-enriched Moon is not required

  11. Gait analysis, bone and muscle density assessment for patients undergoing total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Benedikt Magnússon

    2012-12-01

    Full Text Available Total hip arthroplasty (THA is performed with or without the use of bone cement. Facing the lack of reliable clinical guidelines on decision making whether a patient should receive THA with or without bone cement, a joint clinical and engineering approach is proposed here with the objective to assess patient recovery developing monitoring techniques based on gait analysis, measurements of bone mineral density and structural and functional changes of quadriceps muscles. A clinical trial was conducted with 36 volunteer patients that were undergoing THA surgery for the first time: 18 receiving cemented implant and 18 receiving non-cemented implant. The patients are scanned with Computer Tomographic (CT modality prior-, immediately- and 12 months post-surgery. The CT data are further processed to segment muscles and bones for calculating bone mineral density (BMD. Quadriceps muscle density Hounsfield (HU based value is calculated from the segmented file on healthy and operated leg before and after THA surgery. Furthermore clinical assessment is performed using gait analysis technologies such as a sensing carpet, wireless electrodes and video. Patients undergo these measurements prior-, 6 weeks post - and 52 weeks post-surgery. The preliminary results indicate computational tools and methods that are able to quantitatively analyze patient’s condition pre and post-surgery: The spatial parameters such as step length and stride length increase 6 weeks post op in the patient group receiving cemented implant while the angle in the toe in/out parameter decrease in both patient groups.

  12. Liquid-crystalline polymer holograms for high-density optical storage and photomechanical analysis

    Science.gov (United States)

    Shishido, A.; Akamatsu, N.

    2012-10-01

    We report linear and crosslinked azobenzene containing liquid-crystalline polymers which can be applied to high-density optical storage and photomechanical analysis. We introduced a molecular design concept of multicomponent systems composed of photoresponse, refactive-index change amplification, and transparency units. Taking advantage of characteristics of liquid crystals (optical anisotropy and cooperative motion), polarization holograms were recorded, which enabled us higher-density holographic storage. On the other hand, crosslinked liquid-crystalline azobenzene polymer films were fabricated to investigate the photomechanical behavior. We have found that a large change in Young's modulus is induced by several mol%-cis form production. Furthermore, a unique bending behavior, which cannot be explained by the conventional bending mechanism, was observed in the crosslinked liquid-crystalline polymer films with azobenzene in the side chain.

  13. From Metal Cluster to Metal Nanowire: A Topological Analysis of Electron Density and Band Structure Calculation

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2002-01-01

    Full Text Available Abstract:We investigate a theoretical model of molecular metalwire constructed from linear polynuclear metal complexes. In particular we study the linear Crn metal complex and Cr molecular metalwire. The electron density distributions of the model nanowire and the linear Crn metal complexes, with n = 3, 5, and 7, are calculated by employing CRYSTAL98 package with topological analysis. The preliminary results indicate that the bonding types between any two neighboring Cr are all the same, namely the polarized open-shell interaction. The pattern of electron density distribution in metal complexes resembles that of the model Cr nanowire as the number of metal ions increases. The conductivity of the model Cr nanowire is also tested by performing the band structure calculation.

  14. Use of ELVIS II platform for random process modelling and analysis of its probability density function

    Science.gov (United States)

    Maslennikova, Yu. S.; Nugmanov, I. S.

    2016-08-01

    The problem of probability density function estimation for a random process is one of the most common in practice. There are several methods to solve this problem. Presented laboratory work uses methods of the mathematical statistics to detect patterns in the realization of random process. On the basis of ergodic theory, we construct algorithm for estimating univariate probability density distribution function for a random process. Correlational analysis of realizations is applied to estimate the necessary size of the sample and the time of observation. Hypothesis testing for two probability distributions (normal and Cauchy) is used on the experimental data, using χ2 criterion. To facilitate understanding and clarity of the problem solved, we use ELVIS II platform and LabVIEW software package that allows us to make the necessary calculations, display results of the experiment and, most importantly, to control the experiment. At the same time students are introduced to a LabVIEW software package and its capabilities.

  15. Generalized Thermostatistics and Wavelet Analysis of the Solar Wind and Proton Density Variability

    CERN Document Server

    Bolzan, M J A; Ramos, F M; Fagundes, P R; Sahai, Y; Bolzan, Mauricio J. A.; Rosa, Reinaldo R.; Ramos, Fernando M.; Fagundes, Paulo R.; Sahai, Yogeshwar

    2005-01-01

    In this paper, we analyze the probability density function (PDF) of solar wind velocity and proton density, based on generalized thermostatistics (GT) approach, comparing theoretical results with observational data. The time series analyzed were obtained from the SOHO satellite mission where measurements were sampled every hour. We present in the investigations data for two years of different solar activity: (a) moderate activity (MA) period (1997) and (b) high activity (HA) period (2000). For the MA period, the results show good agreement between experimental data and GT model. For the HA period, the agreement between experimental and theoretical PDFs was fairly good, but some distortions were observed, probably due to intermittent characteristics of turbulent processes. As a complementary analysis, the Global Wavelet Spectrum (GWS) was obtained allowing the characterization of the predominant temporal variability scales for both the periods and the stochastics aspects of the nonlinear solar wind variability...

  16. Insights on the Bayesian spectral density method for operational modal analysis

    Science.gov (United States)

    Au, Siu-Kui

    2016-01-01

    This paper presents a study on the Bayesian spectral density method for operational modal analysis. The method makes Bayesian inference of the modal properties by using the sample power spectral density (PSD) matrix averaged over independent sets of ambient data. In the typical case with a single set of data, it is divided into non-overlapping segments and they are assumed to be independent. This study is motivated by a recent paper that reveals a mathematical equivalence of the method with the Bayesian FFT method. The latter does not require averaging concepts or the independent segment assumption. This study shows that the equivalence does not hold in reality because the theoretical long data asymptotic distribution of the PSD matrix may not be valid. A single time history can be considered long for the Bayesian FFT method but not necessarily for the Bayesian PSD method, depending on the number of segments.

  17. Comparative analysis of laser-triggered proton generation from overdense and low-density targets

    Energy Technology Data Exchange (ETDEWEB)

    Brantov, A.V., E-mail: brantov@sci.lebedev.ru [P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991 (Russian Federation); Bychenkov, V.Yu. [P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii Prospect 53, Moscow 119991 (Russian Federation); Popov, K.I. [Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, K1N 6N5 (Canada); Fedosejevs, R. [Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Rozmus, W. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta, T6G 2J1 (Canada); Schlegel, T. [Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstrasse 1, D-64291 Darmstadt (Germany)

    2011-10-11

    Based on 3D particle-in-cell (PIC) simulations a comparative analysis of laser-triggered proton generation from the interaction of short high-intensity laser pulses with ultrathin foils and dense gas jets has been performed. It has been shown that for ultra-relativistic laser intensities the use of low-density targets with near critical density (aerogel or dense gas jet) has no advantage in comparison with ultrathin foils in terms of maximum proton energy and spectrum quality. Utilization of mass-limited foils with submicron thickness demonstrates even greater superiority for overdense targets and allows one to produce monoenergetic proton beams with energies of hundreds of mega-electron-volts by using high-contrast laser pulses with energies of the order of tens of Joules.

  18. Analysis of 2-d ultrasound cardiac strain imaging using joint probability density functions.

    Science.gov (United States)

    Ma, Chi; Varghese, Tomy

    2014-06-01

    Ultrasound frame rates play a key role for accurate cardiac deformation tracking. Insufficient frame rates lead to an increase in signal de-correlation artifacts resulting in erroneous displacement and strain estimation. Joint probability density distributions generated from estimated axial strain and its associated signal-to-noise ratio provide a useful approach to assess the minimum frame rate requirements. Previous reports have demonstrated that bi-modal distributions in the joint probability density indicate inaccurate strain estimation over a cardiac cycle. In this study, we utilize similar analysis to evaluate a 2-D multi-level displacement tracking and strain estimation algorithm for cardiac strain imaging. The effect of different frame rates, final kernel dimensions and a comparison of radio frequency and envelope based processing are evaluated using echo signals derived from a 3-D finite element cardiac model and five healthy volunteers. Cardiac simulation model analysis demonstrates that the minimum frame rates required to obtain accurate joint probability distributions for the signal-to-noise ratio and strain, for a final kernel dimension of 1 λ by 3 A-lines, was around 42 Hz for radio frequency signals. On the other hand, even a frame rate of 250 Hz with envelope signals did not replicate the ideal joint probability distribution. For the volunteer study, clinical data was acquired only at a 34 Hz frame rate, which appears to be sufficient for radio frequency analysis. We also show that an increase in the final kernel dimensions significantly affect the strain probability distribution and joint probability density function generated, with a smaller effect on the variation in the accumulated mean strain estimated over a cardiac cycle. Our results demonstrate that radio frequency frame rates currently achievable on clinical cardiac ultrasound systems are sufficient for accurate analysis of the strain probability distribution, when a multi-level 2-D

  19. Temperature dependence of Hall electron density of GaN-based heterostructures

    Institute of Scientific and Technical Information of China (English)

    Zhang Jin-Feng; Zhang Jin-Cheng; Hao Yue

    2004-01-01

    The theoretic calculation and analysis of the temperature dependence of Hall electron density of a sample AlGaN/GaN heterostructure has been carried out in the temperature range from 77 to 300K. The densities of the twodimensional electron gas and the bulk electrons are solved by self-consistent calculation of one-dimensional Schrodinger and Poisson equations at different temperatures, which allow for the variation of energy gap and structure strain, and are used for evaluation of the temperature dependence of Hall electron density. The calculated Hall electron density agrees with the measured one quite well with the appropriate bulk mobility data. Analysis revealed that for the temper ature range considered, even in the heterostructures with a small bulk conductance the factors that determine the Hall mobility and electron density could be of different sources, and not just the two-dimensional electron gas as generally supposed.

  20. Bulk chemicals from biomass

    NARCIS (Netherlands)

    Haveren, van J.; Scott, E.L.; Sanders, J.P.M.

    2008-01-01

    Given the current robust forces driving sustainable production, and available biomass conversion technologies, biomass-based routes are expected to make a significant impact on the production of bulk chemicals within 10 years, and a huge impact within 20-30 years. In the Port of Rotterdam there is a

  1. Meta-Analysis of Low Density Lipoprotein Receptor (LDLR rs2228671 Polymorphism and Coronary Heart Disease

    Directory of Open Access Journals (Sweden)

    Huadan Ye

    2014-01-01

    Full Text Available Low density lipoprotein receptor (LDLR can regulate cholesterol metabolism by removing the excess low density lipoprotein cholesterol (LDL-C in blood. Since cholesterol metabolism is often disrupted in coronary heart disease (CHD, LDLR as a candidate gene of CHD has been intensively studied. The goal of our study is to evaluate the overall contribution of LDLR rs2228671 polymorphism to the risk of CHD by combining the genotyping data from multiple case-control studies. Our meta-analysis is involved with 8 case-control studies among 7588 cases and 9711 controls to test the association between LDLR rs2228671 polymorphism and CHD. In addition, we performed a case-control study of LDLR rs2228671 polymorphism with the risk of CHD in Chinese population. Our meta-analysis showed that rs2228671-T allele was significantly associated with a reduced risk of CHD (P=0.0005, odds ratio (OR = 0.83, and 95% confidence interval (95% CI = 0.75–0.92. However, rs2228671-T allele frequency was rare (1% and was not associated with CHD in Han Chinese (P=0.49, suggesting an ethnic difference of LDLR rs2228671 polymorphism. Meta-analysis has established rs2228671 as a protective factor of CHD in Europeans. The lack of association in Chinese reflects an ethnic difference of this genetic variant between Chinese and European populations.

  2. Mapping the Flavor Contributing Traits on "Fengwei Melon" (Cucumis melo L.) Chromosomes Using Parent Resequencing and Super Bulked-Segregant Analysis.

    Science.gov (United States)

    Zhang, Hong; Yi, Hongping; Wu, Mingzhu; Zhang, Yongbin; Zhang, Xuejin; Li, Meihua; Wang, Guangzhi

    2016-01-01

    We used a next-generation high-throughput sequencing platform to resequence the Xinguowei and Shouxing melon cultivars, the parents of Fengwei melon. We found 84% of the reads (under a coverage rate of "13×") placed on the reference genome DHL92. There were 2,550,000 single-nucleotide polymorphisms and 140,000 structural variations in the two genomes. We also identified 1,290 polymorphic genes between Xinguowei and Shouxing. We combined specific length amplified fragment sequencing (SLAF-seq) and bulked-segregant analysis (super-BSA) to analyze the two parents and the F2 extreme phenotypes. This combined method yielded 12,438,270 reads, 46,087 SLAF tags, and 4,480 polymorphic markers (average depth of 161.81×). There were six sweet trait-related regions containing 13 differential SLAF markers, and 23 sour trait-related regions containing 48 differential SLAF markers. We further fine-mapped the sweet trait to the genomic regions on chromosomes 6, 10, 11, and 12. Correspondingly, we mapped the sour trait-related genomic regions to chromosomes 2, 3, 4, 5, 9, and 12. Finally, we positioned nine of the 61 differential markers in the sweet and sour trait candidate regions on the parental genome. These markers corresponded to one sweet and eight sour trait-related genes. Our study provides a basis for marker-assisted breeding of desirable sweet and sour traits in Fengwei melons.

  3. A LEED analysis of the clean surfaces of α-Fe(2)O(3)(0001) and α-Cr(2)O(3)(0001) bulk single crystals.

    Science.gov (United States)

    Lübbe, Maike; Moritz, Wolfgang

    2009-04-01

    We analyzed the (0001) surface structures of hematite and chromia bulk single crystals by low energy electron diffraction (LEED). The hematite crystal was annealed in an O(2) atmosphere, p(O(2))≈3 × 10(-8) mbar, for several hours. The chromia crystal was sputtered with Ar(+) ions, E = 1 keV, and afterward heated up to 900 °C for 5 min under ultra-high-vacuum (UHV) conditions. I(V)-curve data sets of 12 symmetrically independent diffraction spots were measured at room temperature in the energy range E = 150-500 eV. Charging effects hindered measurements at lower energies. Our analysis of the hematite single crystal surface indicates that it is terminated by a single iron layer which is occupied at ≈50%. Relaxation effects along the c-axis are quite large and involve several iron double layers. For the chromia surface the results indicate that termination with a single Cr seems not to hold. Most probably the surface is terminated by two partially occupied Cr sites or chromyl groups. Relaxations in deeper layers are small in contrast to α-Fe(2)O(3)(0001).

  4. Mapping the Flavor Contributing Traits on "Fengwei Melon" (Cucumis melo L. Chromosomes Using Parent Resequencing and Super Bulked-Segregant Analysis.

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    Full Text Available We used a next-generation high-throughput sequencing platform to resequence the Xinguowei and Shouxing melon cultivars, the parents of Fengwei melon. We found 84% of the reads (under a coverage rate of "13×" placed on the reference genome DHL92. There were 2,550,000 single-nucleotide polymorphisms and 140,000 structural variations in the two genomes. We also identified 1,290 polymorphic genes between Xinguowei and Shouxing. We combined specific length amplified fragment sequencing (SLAF-seq and bulked-segregant analysis (super-BSA to analyze the two parents and the F2 extreme phenotypes. This combined method yielded 12,438,270 reads, 46,087 SLAF tags, and 4,480 polymorphic markers (average depth of 161.81×. There were six sweet trait-related regions containing 13 differential SLAF markers, and 23 sour trait-related regions containing 48 differential SLAF markers. We further fine-mapped the sweet trait to the genomic regions on chromosomes 6, 10, 11, and 12. Correspondingly, we mapped the sour trait-related genomic regions to chromosomes 2, 3, 4, 5, 9, and 12. Finally, we positioned nine of the 61 differential markers in the sweet and sour trait candidate regions on the parental genome. These markers corresponded to one sweet and eight sour trait-related genes. Our study provides a basis for marker-assisted breeding of desirable sweet and sour traits in Fengwei melons.

  5. Determination of ammonium in Kjeldahl digests by gas-diffusion flow-injection analysis with a bulk acoustic wave-impedance sensor.

    Science.gov (United States)

    Su, X L; Nie, L H; Yao, S Z

    1997-11-01

    A novel flow-injection analysis (FIA) system has been developed for the rapid and direct determination of ammonium in Kjeldahl digests. The method is based on diffusion of ammonia across a PTFE gas-permeable membrane from an alkaline (NaOH/EDTA) stream into a stream of diluted boric acid. The trapped ammonium in the acceptor is determined on line by a bulk acoustic wave (BAW)-impedance sensor and the signal is proportional to the ammonium concentration present in the digests. The proposed system exhibits a favorable frequency response to 5.0 x 10(-6)-4.0 x 10(-3) mol l(-1) ammonium with a detection limit of 1.0 x 10(-6) mol l(-1), and the precision was better than 1% (RSD) for 0.025-1.0 mM ammonium at a through-put of 45-50 samples h(-1). Results obtained for nitrogen determination in amino acids and for proteins determination in blood products are in good agreement with those obtained by the conventional distillation/titration method, respectively. The effects of composition of acceptor stream, cell constant of conductivity electrode, sample volume, flow rates and potential interferents on the FIA signals were discussed in detail.

  6. Technical issues of a high-Tc superconducting bulk magnet

    Science.gov (United States)

    Fujimoto, Hiroyuki

    2000-06-01

    Superconducting magnets made of high-Tc superconductors are promising for industrial applications. It is well known that REBa2Cu3O7-x superconductors prepared by melt processes have a high critical current density, Jc, at 77 K and high magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger Jc in high magnetic fields and a much improved irreversibility field, Hirr, at 77 K. In this study, we discuss technical issues of a high-Tc superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future.

  7. THE ANALYSIS OF PARTIAL DISCHARGE (PD FROM ELECTRICAL TREEING IN LINEAR LOW DENSITY POLYETHYLENE (LLDPE AND HIGH DENSITY POLYETHYLENE (HDPE

    Directory of Open Access Journals (Sweden)

    Hermawan Hermawan

    2012-02-01

    Full Text Available Recently, the transmission of electric energy has been developed by insulated cable. The suitable materialas an insulated cable is LLDPE and HDPE. In order to understand the quality of insulation system, themeasuring of PD has done. PD could begin completely insulation failure (breakdown. Therefore, it is veryimportant to understand the characteristic of PD and the enclose event on it, because PD is a main factorwhich caused insulation failure.This paper presents the result of PD measurement in the laboratory that used needle-plane electrode. Itwas supported by equipments such as osiloskop Digital GDS 2104 GW Instek, HPF, and RC detector.Polymer sample that used in this research is LLDPE (Linier Low Density Polyethylene and HDPE with 20x 4 x 25 mm3 dimension in each. Needle was made by steel (length 50 mm and diameter 1.15 mm, it wasstick to the polymer material. The distance between needle to the plane is 5 mm. The applied voltage foreach sample was 16 kVrms, 18 kVrms, 20 kVrms and 22 kVrms. The Taking of PD data was done in thefirst minute, 10th minute, 20th and so on until 180th minute.The measurement result shows that the characteristic of PD number and maximum charge as a function oftime and as a function of applied voltage inclined increasing both on LLDPE and HDPE. But, PD intensityin HDPE is higher than LLDPE.

  8. Breast cancer research output, 1945-2008: a bibliometric and density-equalizing analysis

    LENUS (Irish Health Repository)

    Glynn, Ronan W

    2010-12-22

    Abstract Introduction Breast cancer is the most common form of cancer among women, with an estimated 194,280 new cases diagnosed in the United States in 2009 alone. The primary aim of this work was to provide an in-depth evaluation of research yield in breast cancer from 1945 to 2008, using large-scale data analysis, the employment of bibliometric indicators of production and quality, and density-equalizing mapping. Methods Data were retrieved from the Web of Science (WOS) Science Citation Expanded database; this was searched using the Boolean operator, \\'OR\\

  9. Seismic and structural analysis of high density/consolidated spent fuel storage racks

    Energy Technology Data Exchange (ETDEWEB)

    Shah, S.J.; Biddle, J.R.; Bennett, S.M.; Schechter, C.B. [B and W Fuel Co., Lynchburg, VA (United States); Harstead, G.A. [Harstead Engineering Associates, Inc., Old Tappan, NJ (United States); Kopecky, B. [ATEA/FRAMATOME, Carquefou (France)

    1995-12-31

    In many nuclear power plants, existing storage racks are being replaced with high-density racks to accommodate the increasing inventory of spent fuel. In the hypothetical design considered here, the high-density arrangement of fuel assemblies, or consolidated fuel canisters, is accomplished through the use of borated stainless steel (BSS) plates acting as neutron absorbers. The high-density fuel racks are simply supported by the pool floor with no structural connections to adjacent racks or to the pool walls or floor. Therefore, the racks are free standing and may slide and tip. Several time history, nonlinear, seismic analyses are required to account for variations in the coefficient of friction, rack loading configuration, ad the type of the seismic event. This paper presents several of the mathematical models usually used. The models include features to allow sliding and tipping of the racks and to represent the hydrodynamic coupling which can occur between fuel assemblies and rack cells, between adjacent racks, and between the racks and the reinforced concrete walls. A detailed model representing a single rack is used to evaluate the 3-D loading effects. This model is a controlling case for the stress analysis. A 2-D multi-rack model representing a row of racks between the spent fuel pool walls is used to evaluate the change in gaps between racks. The racks are analyzed for the fuel loading conditions of consolidated, full, empty, and half-loaded with fuel assemblies.

  10. Density driven convection with dissolution in porous media: experiment, simulation and linear stability analysis

    Science.gov (United States)

    Meng, Xuhui; Yang, Xiaofan; Guo, Zhaoli

    2016-11-01

    Geological storage of the CO2 in subsurface saline aquifers is a promising way to reduce CO2 emissions. During this process, CO2 first dissolves into pure brine. Then the acidic and denser mixture falls down under the gravity and reacts with the rock. In the present work, a microfluidic experiment is conducted to investigate the density-driven convection with dissolution in porous media. Moreover, the linear stability analysis and numerical simulations are further performed to investigate the interfacial instability. The results demonstrate that front instability can be triggered by the density contrast between the two miscible fluids, leading to the Rayleigh-Taylor instability. While this type of instability can be suppressed by the surface reaction between the fluid and solid phases, which prevents the transport of the denser fluid to the deeper region at the beginning. Over the long term, it is found that the interfacial instability can be influenced by the evolution of the porosity due to the dissolution, which will drive the transport of denser fluid further down. Our investigation shows that the transport of the reactive fluid in porous media depends on the competition among the density contrast, the chemical reaction rate and the evolution of the porosity/permeability.

  11. A statistical analysis of the elastic distortion and dislocation density fields in deformed crystals

    KAUST Repository

    Mohamed, Mamdouh S.

    2015-05-18

    The statistical properties of the elastic distortion fields of dislocations in deforming crystals are investigated using the method of discrete dislocation dynamics to simulate dislocation structures and dislocation density evolution under tensile loading. Probability distribution functions (PDF) and pair correlation functions (PCF) of the simulated internal elastic strains and lattice rotations are generated for tensile strain levels up to 0.85%. The PDFs of simulated lattice rotation are compared with sub-micrometer resolution three-dimensional X-ray microscopy measurements of rotation magnitudes and deformation length scales in 1.0% and 2.3% compression strained Cu single crystals to explore the linkage between experiment and the theoretical analysis. The statistical properties of the deformation simulations are analyzed through determinations of the Nye and Kröner dislocation density tensors. The significance of the magnitudes and the length scales of the elastic strain and the rotation parts of dislocation density tensors are demonstrated, and their relevance to understanding the fundamental aspects of deformation is discussed.

  12. Density-viscosity product of small-volume ionic liquid samples using quartz crystal impedance analysis.

    Science.gov (United States)

    McHale, Glen; Hardacre, Chris; Ge, Rile; Doy, Nicola; Allen, Ray W K; MacInnes, Jordan M; Bown, Mark R; Newton, Michael I

    2008-08-01

    Quartz crystal impedance analysis has been developed as a technique to assess whether room-temperature ionic liquids are Newtonian fluids and as a small-volume method for determining the values of their viscosity-density product, rho eta. Changes in the impedance spectrum of a 5-MHz fundamental frequency quartz crystal induced by a water-miscible room-temperature ionic liquid, 1-butyl-3-methylimiclazolium trifluoromethylsulfonate ([C4mim][OTf]), were measured. From coupled frequency shift and bandwidth changes as the concentration was varied from 0 to 100% ionic liquid, it was determined that this liquid provided a Newtonian response. A second water-immiscible ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4mim][NTf2], with concentration varied using methanol, was tested and also found to provide a Newtonian response. In both cases, the values of the square root of the viscosity-density product deduced from the small-volume quartz crystal technique were consistent with those measured using a viscometer and density meter. The third harmonic of the crystal was found to provide the closest agreement between the two measurement methods; the pure ionic liquids had the largest difference of approximately 10%. In addition, 18 pure ionic liquids were tested, and for 11 of these, good-quality frequency shift and bandwidth data were obtained; these 12 all had a Newtonian response. The frequency shift of the third harmonic was found to vary linearly with square root of viscosity-density product of the pure ionic liquids up to a value of square root(rho eta) approximately 18 kg m(-2) s(-1/2), but with a slope 10% smaller than that predicted by the Kanazawa and Gordon equation. It is envisaged that the quartz crystal technique could be used in a high-throughput microfluidic system for characterizing ionic liquids.

  13. Effects of Density, Beech Crop and Winter Feeding on Survival of Juvenile Great Tits; An Analysis of Kluyver's Removal Experiment

    NARCIS (Netherlands)

    Verhulst, Simon

    1992-01-01

    Density dependent processes and the availability of food may play an important role in the determination of population size. To investigate the relationship between density and local survival of juvenile Great Tits Parus m. major Kluyver removed first brood fledglings in two years. An analysis is pr

  14. Scalp current density mapping in the analysis of mismatch negativity paradigms.

    Science.gov (United States)

    Giard, Marie-Hélène; Besle, Julien; Aguera, Pierre-Emmanuel; Gomot, Marie; Bertrand, Olivier

    2014-07-01

    MMN oddball paradigms are frequently used to assess auditory (dys)functions in clinical populations, or the influence of various factors (such as drugs and alcohol) on auditory processing. A widely used procedure is to compare the MMN responses between two groups of subjects (e.g. patients vs controls), or between experimental conditions in the same group. To correctly interpret these comparisons, it is important to take into account the multiple brain generators that produce the MMN response. To disentangle the different components of the MMN, we describe the advantages of scalp current density (SCD)-or surface Laplacian-computation for ERP analysis. We provide a short conceptual and mathematical description of SCDs, describe their properties, and illustrate with examples from published studies how they can benefit MMN analysis. We conclude with practical tips on how to correctly use and interpret SCDs in this context.

  15. Density and composition analysis using focused MeV ion mubeam techniques

    Science.gov (United States)

    Antolak, A. J.; Bench, G. S.; Pontau, A. E.; Morse, D. H.; Heikkinen, D. W.; Weirup, D. L.

    1994-12-01

    Nuclear muscopy uses focused MeV ion mubeams to non-destructively characterize materials and components with mun scale spatial resolution. Although a number of accelerator-based mubeam methods are available for materials analysis, this paper centers on the techniques of Ion mutomography (IMT) and Particle-Induced X-ray Emission (PIXE). IMT provides quantitative three-dimensional density information with mun-scale spatial resolution and 1% density variation sensitivity. Recently, IMT has become more versatile because greater emphasis has been placed on understanding the effects of reconstruction artifacts, beam spatial broadening, and limited projection data sets. PIXE provides quantitative elemental information with detection sensitivities to 1 μg/g or below in some instances. By scanning the beam, two-dimensional maps of elemental concentration can also be recorded. However, since X-rays are produced along the entire path of the ion beam as it penetrates the sample, these measurements only give depth-averaged information in general. PIXE tomography (PIXET) is the natural extension from conventional PIXE analysis to the full three-dimensional measurement and forms the bridge linking the complementary techniques of PIXE and IMT. This paper presents recent developments and applications of these ion beam techniques in a diverse range of fields including characterizing metal-matrix composites, biological specimens and inertial confinement fusion targets.

  16. Radiative Bulk Viscosity

    CERN Document Server

    Chen, X

    2001-01-01

    Viscous resistance to changes in the volume of a gas arises when different degrees of freedom have different relaxation times. Collisions tend to oppose the resulting departures from equilibrium and, in so doing, generate entropy. Even for a classical gas of hard spheres, when the mean free paths or mean flight times of constituent particles are long, we find a nonvanishing bulk viscosity. Here we apply a method recently used to uncover this result for a classical rarefied gas to radiative transfer theory and derive an expression for the radiative stress tensor for a gray medium with absorption and Thomson scattering. We determine the transport coefficients through the calculation of the comoving entropy generation. When scattering dominates absorption, the bulk viscosity becomes much larger than either the shear viscosity or the thermal conductivity.

  17. 华北高寒区多年保护性耕作对农田土壤容重的影响%Long-term Effects of Conservation Tillage on Soil Bulk Density in Cropping Zone of Cold Plateau in North China

    Institute of Scientific and Technical Information of China (English)

    王岩; 张静; 刘玉华

    2013-01-01

    In order to protect the soil, reduce wind erosion and ensure the production, explore the suitable conservation tillage model for the alpine area in North China, to provide a theoretical basis to the local crop production. Based on located experiment of different farming methods for 9 years in Zhangbei, the ministry of agriculture field station, and in 2007-2008, the author studied the effect of the no-tillage, reduced tillage and traditional tillage soil bulk density. The results showed that 3 types of farming methods at the seeding stage and harvesting stage both with the highest was no tillage and the lowest was traditional tillage, at the seeding stage the 0-10 cm and 10-20 cm soil bulk density of no-tillage, respectively were 1.65 g/cm3 and 1.81 g/cm3, with traditional tillage were 1.38 g/cm3 and 1.47 g/cm3, at harvesting stage there was no significant change. In cold plateau in North China, the soil bulk density of cropping zone had been influenced obviously by different tillage methods, the traditional tillage and reduced tillage could be a significant reduction in soil bulk density. With the bio-power effect of crop root growth, seeding stage and harvesting stage no tillage and reduced tillage in cropping zone soil bulk density was downward trend, and there was no significant change in traditional tillage.%为了在保护土壤、减抑风蚀的同时,兼顾作物的产量,探索适合华北高寒区的保护性耕作模式,给当地作物生产提供理论依据,在农业部张北野外观测站连续9年不同耕作方式定位研究的基础上,于2007-2009年探讨了免耕、松耕和翻耕对土壤耕层容重的影响.结果表明,3种耕作方式播种期不同耕层土壤容重均以免耕最高,翻耕最低,播前0~10 cm、10~20 cm土壤容重免耕分别为1.65、1.81 g/cm3,翻耕则分别为1.38、1.47 g/cm3,收获期土壤容重差异不明显.华北高寒区不同耕作方式对农田耕层土壤容重具有明显的影响,翻耕和松耕

  18. Preparation and Characterization of Copper-Nickel Bulk Nanocrystals

    Institute of Scientific and Technical Information of China (English)

    WU Xiaoqiang; TANG Yongjian; WANG Lan; AN Xuguang; YI Zao; SUN Weiguo

    2014-01-01

    Copper-nickel nanoparticle was directly prepared by flow-levitation method (FL) and sintered by vacuum sintering of powder (VSP) method. Several characterizations, such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal analysis (DTA), and energy-dispersive X-ray spectroscopy (EDX) were used to investigate the prepared nanostructures. The results of the study show that FL method could prepare high purity Cu-Ni nanocrystals of uniform spheres with size distribution between 20 and 90 nm. After sintering the bulk nanocrystalline copper-nickel has obvious thermal stability and the surface Webster hardness increases with the rising sintering temperature. At the temperature of 900℃, the specimen shows higher surface Webster hardness, which is about two times of traditional materials. When the sintering temperature arrives at 1 000℃the relative density of bulk nanocrystals can reach 97.86 percent. In this paper, the variation tendency of porosity, phase and particles size of bulk along with the changing of sintering temperature have been studied.

  19. Spatial Distribution and Density of Dolines in the NW Part of Velika Kapela from GIS Based Buffer Analysis

    OpenAIRE

    Mladen Pahernik

    2000-01-01

    GIS based buffer analysis methods were applied for analysing spatial distribution and density of dolinas in the NW part of Velika Kapela. Results extracted from existing spatial databases indicated spatial distribution of faults, as well as a degree of relationship between direction and density of dolinas with identified lineaments. By comparing faults identified from dolina analysis, with faults identified during on-situ mapping, major tectonic blocks or units within researched area were ide...

  20. Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum) Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

    Science.gov (United States)

    Xu, Xiaomei; Chao, Juan; Cheng, Xueli; Wang, Rui; Sun, Baojuan; Wang, Hengming; Luo, Shaobo; Xu, Xiaowan; Wu, Tingquan; Li, Ying

    2016-01-01

    Phytophthora root rot caused by Phytophthora capsici (P. capsici) is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS). Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334) and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399) were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3) was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA) and Specific Length Amplified Fragment sequencing (SLAF-seq) provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR) markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away) and P52-11-41 (1.1 cM). A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

  1. Maximum trapped field of a ring bulk superconductor by low pulsed field magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchimoto, M. [Hokkaido Institute of Technology, 7-15 Maeda, Teine-ku, Sapporo 006-8585 (Japan)], E-mail: tsuchi@hit.ac.jp; Kamijo, H. [Railway Technical Research Institute, 2-8-38, Hikari-cho, Kokubunji, Tokyo 185-8540 (Japan)

    2007-10-01

    Pulsed field magnetization is an important technique for a bulk superconducting magnet, which is one practical application of a bulk high T{sub c} superconductor (HTS). Full magnetization of a ring HTS is effective to obtain large trapped field for low pulsed field magnetization. In this study, trapped field in a ring bulk superconductor by the low pulsed field magnetization is numerically analyzed under assumption of variable shielding current by the temperature control. Differences between one-dimensional Bean model and axisymmetric three-dimensional numerical solution are discussed through the analysis. There is maximum trapped field in the axisymmetric three-dimensional model because of finite thickness of the ring HTS. The shielding current density and inner radius of the ring HTS are discussed to obtain the maximum trapped field.

  2. Development of superconductor bulk for superconductor bearing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Joong; Jun, Byung Hyuk; Park, Soon Dong (and others)

    2008-08-15

    Current carrying capacity is one of the most important issues in the consideration of superconductor bulk materials for engineering applications. There are numerous applications of Y-Ba-Cu-O (YBCO) bulk superconductors e.g. magnetic levitation train, flywheel energy storage system, levitation transportation, lunar telescope, centrifugal device, magnetic shielding materials, bulk magnets etc. Accordingly, to obtain YBCO materials in the form of large, single crystals without weak-link problem is necessary. A top seeded melt growth (TSMG) process was used to fabricate single crystal YBCO bulk superconductors. The seeded and infiltration growth (IG) technique was also very promising method for the synthesis of large, single-grain YBCO bulk superconductors with good superconducting properties. 5 wt.% Ag doped Y211 green compacts were sintered at 900 .deg. C {approx} 1200 .deg.C and then a single crystal YBCO was fabricated by an infiltration method. A refinement and uniform distribution of the Y211 particles in the Y123 matrix were achieved by sintering the Ag-doped samples. This enhancement of the critical current density was ascribable to a fine dispersion of the Y211 particles, a low porosity and the presence of Ag particles. In addition, we have designed and manufactured large YBCO single domain with levitation force of 10-13 kg/cm{sup 2} using TSMG processing technique.

  3. Analysis of nanosecond breaking of a high-density current in SOS diodes

    Science.gov (United States)

    Grekhov, I. V.; Lyublinskii, A. G.; Smirnova, I. A.

    2015-11-01

    Effect of a sharp (nanosecond) breaking of the reverse current with a density on the order of 103-104 A/cm2 in a silicon diode upon switching from direct to reverse bias voltage (so-called silicon opening switch, or SOS effect) is widely used in nanosecond technologies of gigawatt powers. For detailed analysis of the SOS effect, we constructed a special setup with small stray inductance, which makes it possible to test single SOS diodes with a working area of 1-2 mm2 in a wide range of current densities. Our experiments show, in particular, that the numerical model of the SOS effect developed at the Institute of Electrophysics, Ural Branch, Russian Academy of Sciences successfully described the experimental results. It is also shown that the charge extracted from the diode structure by the reverse current exceeds the charge introduced by a direct current pulse by not more than 10%, indicating a relatively small role of ionization processes. The possibility to carry out experiments on single samples with a small surface area allows us to study the SOS effect and considerably facilitates investigations aimed at the perfection of the design of SOS diodes.

  4. Scientometric analysis and combined density-equalizing mapping of environmental tobacco smoke (ETS research.

    Directory of Open Access Journals (Sweden)

    Karin Vitzthum

    Full Text Available BACKGROUND: Passive exposure to environmental tobacco smoke (ETS is estimated to exert a major burden of disease. Currently, numerous countries have taken legal actions to protect the population against ETS. Numerous studies have been conducted in this field. Therefore, scientometric methods should be used to analyze the accumulated data since there is no such approach available so far. METHODS AND RESULTS: A combination of scientometric methods and novel visualizing procedures were used, including density-equalizing mapping and radar charting techniques. 6,580 ETS-related studies published between 1900 and 2008 were identified in the ISI database. Using different scientometric approaches, a continuous increase of both quantitative and qualitative parameters was found. The combination with density-equalizing calculations demonstrated a leading position of the United States (2,959 items published in terms of quantitative research activities. Charting techniques demonstrated that there are numerous bi- and multilateral networks between different countries and institutions in this field. Again, a leading position of American institutions was found. CONCLUSIONS: This is the first comprehensive scientometric analysis of data on global scientific activities in the field of environmental tobacco smoke research. The present findings can be used as a benchmark for funding allocation processes.

  5. Static and Dynamic Electronic (Hyperpolarizabilities of Dimethylnaphthalene Isomers: Characterization of Spatial Contributions by Density Analysis

    Directory of Open Access Journals (Sweden)

    Andrea Alparone

    2013-01-01

    Full Text Available Static and frequency-dependent electronic (hyperpolarizabilities of the dimethylnaphthalene (DMN isomers were computed in vacuum using the Coulomb-attenuating Density Functional Theory method. The nonlinear optical Second Harmonic Generation (SHG and Electro-Optical Pockels Effect (EOPE were investigated at the characteristic Nd:YAG laser wavelength of 1064 nm. The response electric properties especially the longitudinal polarizability, polarizability anisotropy, and first-order hyperpolarizability are significantly affected by the position of the methyl groups. The SHG and EOPE techniques can be potentially useful to discriminate the ,-DMN isomers (2,6-DMN < 2,7-DMN < 2,3-DMN as well as the ,-DMN isomers (1,5-DMN < 1,4-DMN < 1,8-DMN. The (hyperpolarizability differences among the investigated DMNs were elucidated through density analysis calculations. The predicted polarizabilities exhibit good linear relationships with the experimental first-order biomass-normalized rate coefficient, a physicochemical property connected to the rates of biodegradation processes of polycyclic aromatic hydrocarbons.

  6. MEASUREMENT OF ROOT LENGTH DENSITY IN INTACT SAMPLES USING X-RADIOGRAPHY AND IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Alain Pierret

    2011-05-01

    Full Text Available Measurement of root system attributes is of critical importance to understand and model plant growth. Root length density, the length of roots per unit volume of soil, is one of the important parameters required to understand plant performance. Measuring techniques currently in use to assess this parameter, such as for example core washing, are notoriously imprecise and labour-intensive. Roots and soil being inextricably linked, it is virtually impossible to separate them without loosing a significant amount of the root sample to be measured. This noticeably compromises the accuracy of washing techniques. For this reason, non-invasive measurement approaches are highly desirable. Here, a method based on the combination of X-radiography and image analysis is proposed as a new alternative for the measurement of root length density from intact samples. The successive steps of the method, from sampling to image acquisition are briefly described. A specific measurement algorithm, designed to account for the complex spatial arrangement of the roots within the samples is then presented and discussed in detail.

  7. Protein backbone dynamics revealed by quasi spectral density function analysis of amide N-15 nuclei.

    Science.gov (United States)

    Ishima, R; Nagayama, K

    1995-03-14

    Spectral density functions J(0), J(omega N), and J(omega H + omega N) of individual amide N-15 nuclei in proteins were approximated by a quasi spectral density function (QSDF). Using this function, the backbone dynamics were analyzed for seven protein systems on which data have been published. We defined J(0; omega N) as the difference between the J(0) and the J(omega N) values, which describes motions slower than 50 (or 60) MHz, and J(omega N; omega H+N) as the difference between the J(omega N) and the J(omega H + omega N) values, which describes motions slower than 450 (or 540) MHz. The QSDF analysis can easily extract the J(0; omega N) of protein backbones, which have often some relation to biologically relevant reactions. Flexible N-terminal regions in eglin c and glucose permease IIA and a loop region in eglin c showed smaller values of both the J(0; omega N) and the J(omega N; omega H+N) as compared with the other regions, indicating increases in motions faster than nanosecond. The values of the J(0; omega N) for the backbone of the FK506 binding protein showed a large variation in the apoprotein but fell in a very narrow range after the binding of FK506. Characteristic increase or decrease in the values of J(0) and J(omega N) was observed in two or three residues located between secondary structures.

  8. Propositional idea density in older men's written language: findings from the HIMS study using computerised analysis.

    Science.gov (United States)

    Spencer, Elizabeth; Ferguson, Alison; Craig, Hugh; Colyvas, Kim; Hankey, Graeme J; Flicker, Leon

    2015-02-01

    Decline in linguistic function has been associated with decline in cognitive function in previous research. This research investigated the informativeness of written language samples of Australian men from the Health in Men's Study (HIMS) aged from 76 to 93 years using the Computerised Propositional Idea Density Rater (CPIDR 5.1). In total, 60,255 words in 1147 comments were analysed using a linear-mixed model for statistical analysis. Results indicated no relationship with education level (p = 0.79). Participants for whom English was not their first learnt language showed Propositional Idea Density (PD) scores slightly lower (0.018 per 1 word). Mean PD per 1 word for those for whom English was their first language for comments below 60 words was 0.494 and above 60 words 0.526. Text length was found to have an effect (p = <0.0001). The mean PD was higher than previously reported for men and lower than previously reported for a similar cohort for Australian women.

  9. Analysis of rocket beacon transmissions for computerized reconstruction of ionospheric densities

    Science.gov (United States)

    Bernhardt, P. A.; Huba, J. D.; Chaturvedi, P. K.; Fulford, J. A.; Forsyth, P. A.; Anderson, D. N.; Zalesak, S. T.

    1993-08-01

    Three methods are described to obtain ionospheric electron densities from transionospheric, rocket-beacon TEC data. First, when the line-of-sight from a ground receiver to the rocket beacon is tangent to the flight trajectory, the electron concentration can be obtained by differentiating the TEC with respect to the distance to the rocket. A similar method may be used to obtain the electron-density profile if the layer is horizontally stratified. Second, TEC data obtained during chemical release experiments may be interpreted with the aid of physical models of the disturbed ionosphere to yield spatial maps of the modified regions. Third, computerized tomography (CT) can be used to analyze TEC data obtained along a chain of ground-based receivers aligned along the plane of the rocket trajectory. CT analysis of TEC data is used to reconstruct a 2D image of a simulated equatorial plume. TEC data is computed for a linear chain of nine receivers with adjacent spacings of either 100 or 200 km. The simulation data are analyzed to provide an F region reconstruction on a grid with 15 x 15 km pixels. Ionospheric rocket tomography may also be applied to rocket-assisted measurements of amplitude and phase scintillations and airglow intensities.

  10. Global SAXS data analysis for multilamellar vesicles: Evolution of the scattering density profile (SDP) model

    CERN Document Server

    Heftberger, Peter; Heberle, Frederick A; Pan, Jianjun; Rappolt, Michael; Amenitsch, Heinz; Kucerka, Norbert; Katsaras, John; Pabst, Georg

    2013-01-01

    We adapted the highly successful scattering density pro?le (SDP) model, which is used to jointly analyze small angle x-ray and neutron scattering data from unilamellar vesicles, for use with data from fully hydrated, liquid crystalline multilamellar vesicles (MLVs). By using a genetic algorithm, this new method is capable of providing high resolution structural information, as well as determining bilayer elastic bending fluctuations from standalone x-ray data. Important structural parameters, such as bilayer thickness and area per lipid were determined for a series of saturated and unsaturated lipids, as well as binary mixtures with cholesterol. Results are in good agreement with previously reported SDP data, which used both neutron and x-ray data. The addition of deuterated and non-deuterated MLV neutron data to the analysis improved lipid backbone information, but did not improve, within experimental uncertainties, the structural information regarding bilayer thickness and area per lipid.

  11. Critical parameters governing energy density of Li-storage cathode materials unraveled by confirmatory factor analysis

    Science.gov (United States)

    Sohn, Kee-Sun; Han, Su Cheol; Park, Woon Bae; Pyo, Myoungho

    2016-03-01

    Despite extensive effort during the past few decades, a comprehensive understanding of the key variables governing the electrochemical properties of cathode materials in Li-ion batteries is still far from complete. To elucidate the critical parameters affecting energy density (ED) and capacity (Q) retention in layer and spinel cathodes, we data-mine the existing experimental data via confirmatory factor analysis (CFA) based on a structural equation model (SEM), which is a proven, versatile tool in understanding complex problems in the social science. The data sets are composed of 18 and 15 parameters extracted from 38 layer and 33 spinel compounds, respectively. CFA reveals the irrelevance of Q retention to all the parameters we adopt, but it also reveals the sensitive variations of ED with specific parameters. We validate the usefulness of CFA in material science and pinpointed critical parameters for high-ED cathodes, hoping to suggest a new insight in materials design.

  12. PERFORMANCE OPTIMIZATION OF LINEAR INDUCTION MOTOR BY EDDY CURRENT AND FLUX DENSITY DISTRIBUTION ANALYSIS

    Directory of Open Access Journals (Sweden)

    M. S. MANNA

    2011-12-01

    Full Text Available The development of electromagnetic devices as machines, transformers, heating devices confronts the engineers with several problems. For the design of an optimized geometry and the prediction of the operational behaviour an accurate knowledge of the dependencies of the field quantities inside the magnetic circuits is necessary. This paper provides the eddy current and core flux density distribution analysis in linear induction motor. Magnetic flux in the air gap of the Linear Induction Motor (LIM is reduced to various losses such as end effects, fringes, effect, skin effects etc. The finite element based software package COMSOL Multiphysics Inc. USA is used to get the reliable and accurate computational results for optimization the performance of Linear Induction Motor (LIM. The geometrical characteristics of LIM are varied to find the optimal point of thrust and minimum flux leakage during static and dynamic conditions.

  13. Vibrational spectroscopy and density functional theory analysis of 3-O-caffeoylquinic acid

    Science.gov (United States)

    Mishra, Soni; Tandon, Poonam; Eravuchira, Pinkie J.; El-Abassy, Rasha M.; Materny, Arnulf

    2013-03-01

    Density functional theory (DFT) calculations are being performed to investigate the geometric, vibrational, and electronic properties of the chlorogenic acid isomer 3-CQA (1R,3R,4S,5R)-3-{[(2E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-1,4,5-trihydroxycyclohexanecarboxylic acid), a major phenolic compound in coffee. DFT calculations with the 6-311G(d,p) basis set produce very good results. The electrostatic potential mapped onto an isodensity surface has been obtained. A natural bond orbital analysis (NBO) has been performed in order to study intramolecular bonding, interactions among bonds, and delocalization of unpaired electrons. HOMO-LUMO studies give insights into the interaction of the molecule with other species. The calculated HOMO and LUMO energies indicate that a charge transfer occurs within the molecule.

  14. Assessing climate model software quality: a defect density analysis of three models

    Directory of Open Access Journals (Sweden)

    J. Pipitone

    2012-08-01

    Full Text Available A climate model is an executable theory of the climate; the model encapsulates climatological theories in software so that they can be simulated and their implications investigated. Thus, in order to trust a climate model, one must trust that the software it is built from is built correctly. Our study explores the nature of software quality in the context of climate modelling. We performed an analysis of defect reports and defect fixes in several versions of leading global climate models by collecting defect data from bug tracking systems and version control repository comments. We found that the climate models all have very low defect densities compared to well-known, similarly sized open-source projects. We discuss the implications of our findings for the assessment of climate model software trustworthiness.

  15. Current-source density analysis of slow brain potentials during time estimation.

    Science.gov (United States)

    Gibbons, Henning; Rammsayer, Thomas H

    2004-11-01

    Two event-related potential studies were conducted to investigate differential brain correlates of temporal processing of intervals below and above 3-4 s. In the first experiment, 24 participants were presented with auditorily marked target durations of 2, 4, and 6 s that had to be reproduced. Timing accuracy was similar for all three target durations. As revealed by current-source density analysis, slow-wave components during both presentation and reproduction were independent of target duration. Experiment 2 examined potential modulating effects of type of interval (filled and empty) and presentation mode (randomized and blocked presentation of target durations). Behavioral and slow-wave findings were consistent with those of Experiment 1. Thus, the present findings support the notion of a general timing mechanism irrespective of interval duration as proposed by scalar timing theory and pacemaker-counter models of time estimation.

  16. Correlação linear e espacial entre produtividade de Brachiaria brizantha, densidade do solo e porosidade total em função do sistema de manejo do solo Linear and spatial correlations among forage yield, bulk density and total porosity in function of soil management system

    Directory of Open Access Journals (Sweden)

    Edney L. da Vitória

    2012-10-01

    Full Text Available A densidade e a porosidade são propriedades físicas do solo que são alteradas em função do sistema de manejo utilizado, com consequente influência sobre a produtividade das culturas. A produtividade da planta forrageira, Brachiaria brizantha, em função da densidade do solo e da porosidade total foi analisada em dois sistemas de manejo de solo, em experimento conduzido no segundo semestre de 2009, no município de Santa Teresa, no Estado do Espírito Santo. O objetivo foi estudar a variabilidade e as correlações lineares e espaciais entre os atributos da planta e do solo, visando a selecionar um indicador da qualidade física do solo de boa representatividade para produtividade de forragem. Marcaram-se duas parcelas de 40 m por 50 m a cada 5 m, em duas direções, resultando em um reticulado retangular de 99 pontos, em cada um dos sistemas utilizados: preparo convencional e plantio direto. Os atributos estudados, além de não terem variado aleatoriamente, apresentaram variabilidade dos dados entre média e alta, e seguiram padrões espaciais bem definidos, com alcance entre 20,3 e 24,2 m. Por sua vez, a correlação linear entre o atributo da planta e os do solo, em função do elevado número de observações, foi baixa. A melhor correlação para produtividade de matéria seca foi com a densidade do solo na profundidade de 0,0 - 0,15 m, independentemente do sistema de manejo do solo, indicando que a produtividade e a densidade do solo são inversamente proporcionais. Portanto, a densidade do solo avaliada na camada de 0,0 - 0,15 m apresentou-se como satisfatório indicador da qualidade física do solo, quando se considerou a produtividade da forrageira.Total porosity and bulk density are strongly affected by soil management, which reflects directly in agricultural productivity. The productivity of the forage, Brachiaria brizantha, in function of bulk density and total porosity was analyzed in two soil management systems, in an

  17. Type 2 Diabetes Research Yield, 1951-2012: Bibliometrics Analysis and Density-Equalizing Mapping.

    Directory of Open Access Journals (Sweden)

    Fiona Geaney

    Full Text Available The objective of this paper is to provide a detailed evaluation of type 2 diabetes mellitus research output from 1951-2012, using large-scale data analysis, bibliometric indicators and density-equalizing mapping. Data were retrieved from the Science Citation Index Expanded database, one of the seven curated databases within Web of Science. Using Boolean operators "OR", "AND" and "NOT", a search strategy was developed to estimate the total number of published items. Only studies with an English abstract were eligible. Type 1 diabetes and gestational diabetes items were excluded. Specific software developed for the database analysed the data. Information including titles, authors' affiliations and publication years were extracted from all files and exported to excel. Density-equalizing mapping was conducted as described by Groenberg-Kloft et al, 2008. A total of 24,783 items were published and cited 476,002 times. The greatest number of outputs were published in 2010 (n=2,139. The United States contributed 28.8% to the overall output, followed by the United Kingdom (8.2% and Japan (7.7%. Bilateral cooperation was most common between the United States and United Kingdom (n=237. Harvard University produced 2% of all publications, followed by the University of California (1.1%. The leading journals were Diabetes, Diabetologia and Diabetes Care and they contributed 9.3%, 7.3% and 4.0% of the research yield, respectively. In conclusion, the volume of research is rising in parallel with the increasing global burden of disease due to type 2 diabetes mellitus. Bibliometrics analysis provides useful information to scientists and funding agencies involved in the development and implementation of research strategies to address global health issues.

  18. Probability Density Components Analysis: A New Approach to Treatment and Classification of SAR Images

    Directory of Open Access Journals (Sweden)

    Osmar Abílio de Carvalho Júnior

    2014-04-01

    Full Text Available Speckle noise (salt and pepper is inherent to synthetic aperture radar (SAR, which causes a usual noise-like granular aspect and complicates the image classification. In SAR image analysis, the spatial information might be a particular benefit for denoising and mapping classes characterized by a statistical distribution of the pixel intensities from a complex and heterogeneous spectral response. This paper proposes the Probability Density Components Analysis (PDCA, a new alternative that combines filtering and frequency histogram to improve the classification procedure for the single-channel synthetic aperture radar (SAR images. This method was tested on L-band SAR data from the Advanced Land Observation System (ALOS Phased-Array Synthetic-Aperture Radar (PALSAR sensor. The study area is localized in the Brazilian Amazon rainforest, northern Rondônia State (municipality of Candeias do Jamari, containing forest and land use patterns. The proposed algorithm uses a moving window over the image, estimating the probability density curve in different image components. Therefore, a single input image generates an output with multi-components. Initially the multi-components should be treated by noise-reduction methods, such as maximum noise fraction (MNF or noise-adjusted principal components (NAPCs. Both methods enable reducing noise as well as the ordering of multi-component data in terms of the image quality. In this paper, the NAPC applied to multi-components provided large reductions in the noise levels, and the color composites considering the first NAPC enhance the classification of different surface features. In the spectral classification, the Spectral Correlation Mapper and Minimum Distance were used. The results obtained presented as similar to the visual interpretation of optical images from TM-Landsat and Google Maps.

  19. Type 2 Diabetes Research Yield, 1951-2012: Bibliometrics Analysis and Density-Equalizing Mapping.

    Science.gov (United States)

    Geaney, Fiona; Scutaru, Cristian; Kelly, Clare; Glynn, Ronan W; Perry, Ivan J

    2015-01-01

    The objective of this paper is to provide a detailed evaluation of type 2 diabetes mellitus research output from 1951-2012, using large-scale data analysis, bibliometric indicators and density-equalizing mapping. Data were retrieved from the Science Citation Index Expanded database, one of the seven curated databases within Web of Science. Using Boolean operators "OR", "AND" and "NOT", a search strategy was developed to estimate the total number of published items. Only studies with an English abstract were eligible. Type 1 diabetes and gestational diabetes items were excluded. Specific software developed for the database analysed the data. Information including titles, authors' affiliations and publication years were extracted from all files and exported to excel. Density-equalizing mapping was conducted as described by Groenberg-Kloft et al, 2008. A total of 24,783 items were published and cited 476,002 times. The greatest number of outputs were published in 2010 (n=2,139). The United States contributed 28.8% to the overall output, followed by the United Kingdom (8.2%) and Japan (7.7%). Bilateral cooperation was most common between the United States and United Kingdom (n=237). Harvard University produced 2% of all publications, followed by the University of California (1.1%). The leading journals were Diabetes, Diabetologia and Diabetes Care and they contributed 9.3%, 7.3% and 4.0% of the research yield, respectively. In conclusion, the volume of research is rising in parallel with the increasing global burden of disease due to type 2 diabetes mellitus. Bibliometrics analysis provides useful information to scientists and funding agencies involved in the development and implementation of research strategies to address global health issues.

  20. Effects of bulk viscosity on cosmological evolution

    CERN Document Server

    Pimentel, L O; Pimentel, L O; Diaz-Rivera, L M

    1994-01-01

    Abstract:The effect of bulk viscisity on the evolution of the homogeneous and isotropic cosmological models is considered. Solutions are found, with a barotropic equation of state, and a viscosity coefficient that is proportional to a power of the energy density of the universe. For flat space, power law expansions, related to extended inflation are found as well as exponential solutions, related to old inflation; also a solution with expansion that is an exponential of an exponential of the time is found.

  1. Gravitational potential wells and the cosmic bulk flow

    CERN Document Server

    Kumar, Abhinav; Feldman, Hume A; Watkins, Richard

    2015-01-01

    The bulk flow is a volume average of the peculiar velocities and a useful probe of the mass distribution on large scales. The gravitational instability model views the bulk flow as a potential flow that obeys a Maxwellian Distribution. We use two N-body simulations, the LasDamas Carmen and the Horizon Run, to calculate the bulk flows of various sized volumes in the simulation boxes. Once we have the bulk flow velocities as a function of scale, we investigate the mass and gravitational potential distribution around the volume. We found that matter densities can be asymmetrical and difficult to detect in real surveys, however, the gravitational potential and its gradient may provide better tools to investigate the underlying matter distribution. This study shows that bulk flows are indeed potential flows and thus provides information on the flow sources. We also show that bulk flow magnitudes follow a Maxwellian distribution on scales $>10\\ h^{-1}$Mpc.

  2. Comparative linkage analysis and visualization of high-density oligonucleotide SNP array data

    Directory of Open Access Journals (Sweden)

    Smith Richard JH

    2005-02-01

    Full Text Available Abstract Background The identification of disease-associated genes using single nucleotide polymorphisms (SNPs has been increasingly reported. In particular, the Affymetrix Mapping 10 K SNP microarray platform uses one PCR primer to amplify the DNA samples and determine the genotype of more than 10,000 SNPs in the human genome. This provides the opportunity for large scale, rapid and cost-effective genotyping assays for linkage analysis. However, the analysis of such datasets is nontrivial because of the large number of markers, and visualizing the linkage scores in the context of genome maps remains less automated using the current linkage analysis software packages. For example, the haplotyping results are commonly represented in the text format. Results Here we report the development of a novel software tool called CompareLinkage for automated formatting of the Affymetrix Mapping 10 K genotype data into the "Linkage" format and the subsequent analysis with multi-point linkage software programs such as Merlin and Allegro. The new software has the ability to visualize the results for all these programs in dChip in the context of genome annotations and cytoband information. In addition we implemented a variant of the Lander-Green algorithm in the dChipLinkage module of dChip software (V1.3 to perform parametric linkage analysis and haplotyping of SNP array data. These functions are integrated with the existing modules of dChip to visualize SNP genotype data together with LOD score curves. We have analyzed three families with recessive and dominant diseases using the new software programs and the comparison results are presented and discussed. Conclusions The CompareLinkage and dChipLinkage software packages are freely available. They provide the visualization tools for high-density oligonucleotide SNP array data, as well as the automated functions for formatting SNP array data for the linkage analysis programs Merlin and Allegro and calling

  3. Optical Density Analysis of X-Rays Utilizing Calibration Tooling to Estimate Thickness of Parts

    Science.gov (United States)

    Grau, David

    2012-01-01

    This process is designed to estimate the thickness change of a material through data analysis of a digitized version of an x-ray (or a digital x-ray) containing the material (with the thickness in question) and various tooling. Using this process, it is possible to estimate a material's thickness change in a region of the material or part that is thinner than the rest of the reference thickness. However, that same principle process can be used to determine the thickness change of material using a thinner region to determine thickening, or it can be used to develop contour plots of an entire part. Proper tooling must be used. An x-ray film with an S-shaped characteristic curve or a digital x-ray device with a product resulting in like characteristics is necessary. If a film exists with linear characteristics, this type of film would be ideal; however, at the time of this reporting, no such film has been known. Machined components (with known fractional thicknesses) of a like material (similar density) to that of the material to be measured are necessary. The machined components should have machined through-holes. For ease of use and better accuracy, the throughholes should be a size larger than 0.125 in. (.3 mm). Standard components for this use are known as penetrameters or image quality indicators. Also needed is standard x-ray equipment, if film is used in place of digital equipment, or x-ray digitization equipment with proven conversion properties. Typical x-ray digitization equipment is commonly used in the medical industry, and creates digital images of x-rays in DICOM format. It is recommended to scan the image in a 16-bit format. However, 12-bit and 8-bit resolutions are acceptable. Finally, x-ray analysis software that allows accurate digital image density calculations, such as Image-J freeware, is needed. The actual procedure requires the test article to be placed on the raw x-ray, ensuring the region of interest is aligned for perpendicular x-ray exposure

  4. A space-time analysis of Mycoplasma bovis: bulk tank milk antibody screening results from all Danish dairy herds in 2013-2014

    DEFF Research Database (Denmark)

    Arede, Margarida; Nielsen, Per Kantsø; Ahmed, Syed Sayeem Uddin;

    2016-01-01

    , using the indirect BIO K 302 M. bovis enzyme-linked immunosorbent assay (ELISA) (Bio-X, Belgium) in bulk tank milk from all dairy herds between June 2013 and July 2014. The objective of this study was to investigate the evolution of the spatial distribution of M. bovis in the Danish dairy herd...

  5. Analysis of the AlGaN/GaN vertical bulk current on Si, sapphire, and free-standing GaN substrates

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Tomas, A.; Fontsere, A.; Llobet, J. [IMB-CNM-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, CAT (Spain); Placidi, M. [IREC, Jardins Dones de Negre 1, 08930 Sant Adria de Besos, Barcelona (Spain); Rennesson, S.; Chenot, S.; Moreno, J. C.; Cordier, Y. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Baron, N. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); PICOGIGA International, Pl M. Rebuffat, Courtaboeuf 7, 91140 Villejust (France)

    2013-05-07

    The vertical bulk (drain-bulk) current (I{sub db}) properties of analogous AlGaN/GaN hetero-structures molecular beam epitaxially grown on silicon, sapphire, and free-standing GaN (FS-GaN) have been evaluated in this paper. The experimental I{sub db} (25-300 Degree-Sign C) have been well reproduced with physical models based on a combination of Poole-Frenkel (trap assisted) and hopping (resistive) conduction mechanisms. The thermal activation energies (E{sub a}), the (soft or destructive) vertical breakdown voltage (V{sub B}), and the effect of inverting the drain-bulk polarity have also been comparatively investigated. GaN-on-FS-GaN appears to adhere to the resistive mechanism (E{sub a} = 0.35 eV at T = 25-300 Degree-Sign C; V{sub B} = 840 V), GaN-on-sapphire follows the trap assisted mechanism (E{sub a} = 2.5 eV at T > 265 Degree-Sign C; V{sub B} > 1100 V), and the GaN-on-Si is well reproduced with a combination of the two mechanisms (E{sub a} = 0.35 eV at T > 150 Degree-Sign C; V{sub B} = 420 V). Finally, the relationship between the vertical bulk current and the lateral AlGaN/GaN transistor leakage current is explored.

  6. Influence of shrub cover vegetal and slope length on soil bulk density; Influencia de la cubierta vegetal arbustiva y la longitud de la ladera sobre la densidad aparente del suelo

    Energy Technology Data Exchange (ETDEWEB)

    Bienes, R.; Jimenez, R.; Ruiz, M.; Garcia-Estringana, P.; Marques, M. J.

    2009-07-01

    In arid and semiarid environments of the Mediterranean climate, the shrub species play an important role in the revegetation of abandoned lands, which enables to control the soil losses, organic material and water. In this article are compared the results obtained under different revegetation in abandoned lands in the central area of Spain. In these revegetation has been used two native shrubs: A triplex halimus (Ah) and Retama sphaerocarpa (Rs), and were analyzed the influence of these revegetation in the contents of organic material of soil and apparent density in 5 years time after planting. As control, have been considered the pieces of ground with spontaneous vegetation abandoned in the same date that the shrubs revegetation. Atriplex halimus gives to the soil a covering capable to intercept a big amount of water drops absorbing a great amount part of the kinetic energy of the rain, while provides a microclimates as a result of be able to soften the wind, the temperature and the evaporation-transpiration, which makes it efficient to control the erosion and the desertification (Le Houerou, 2000). Retama sphaerocarpa was chosen because it is a native shrub very characteristic, and, due to its symbiosis with the Bradyrhizobium, enriches the soil in nitrogen, which is taken by the nitrophilous species enhancing the spontaneous vegetal covering. (Author) 9 refs.

  7. Analysis of physical mechanisms underlying density-dependent transport in porous media

    OpenAIRE

    Landman, A.J.

    2005-01-01

    In this thesis, the interaction between (large) density gradients and flow and transport in porous media is studied. Large gradients in the density of groundwater exist for example near deep salt rock formations, which are considered as possible long-term storage sites for radioactive waste. Furthermore, density effects play a role in many other groundwater applications, such as salt water intrusion. Density gradients mainly affect the flow field and mass transport in two ways: by fluid volum...

  8. Analysis and improvement of Brinkman lattice Boltzmann schemes: bulk, boundary, interface. Similarity and distinctness with finite elements in heterogeneous porous media.

    Science.gov (United States)

    Ginzburg, Irina; Silva, Goncalo; Talon, Laurent

    2015-02-01

    This work focuses on the numerical solution of the Stokes-Brinkman equation for a voxel-type porous-media grid, resolved by one to eight spacings per permeability contrast of 1 to 10 orders in magnitude. It is first analytically demonstrated that the lattice Boltzmann method (LBM) and the linear-finite-element method (FEM) both suffer from the viscosity correction induced by the linear variation of the resistance with the velocity. This numerical artefact may lead to an apparent negative viscosity in low-permeable blocks, inducing spurious velocity oscillations. The two-relaxation-times (TRT) LBM may control this effect thanks to free-tunable two-rates combination Λ. Moreover, the Brinkman-force-based BF-TRT schemes may maintain the nondimensional Darcy group and produce viscosity-independent permeability provided that the spatial distribution of Λ is fixed independently of the kinematic viscosity. Such a property is lost not only in the BF-BGK scheme but also by "partial bounce-back" TRT gray models, as shown in this work. Further, we propose a consistent and improved IBF-TRT model which vanishes viscosity correction via simple specific adjusting of the viscous-mode relaxation rate to local permeability value. This prevents the model from velocity fluctuations and, in parallel, improves for effective permeability measurements, from porous channel to multidimensions. The framework of our exact analysis employs a symbolic approach developed for both LBM and FEM in single and stratified, unconfined, and bounded channels. It shows that even with similar bulk discretization, BF, IBF, and FEM may manifest quite different velocity profiles on the coarse grids due to their intrinsic contrasts in the setting of interface continuity and no-slip conditions. While FEM enforces them on the grid vertexes, the LBM prescribes them implicitly. We derive effective LBM continuity conditions and show that the heterogeneous viscosity correction impacts them, a property also shared

  9. Can molecular projected density of states (PDOS be systematically used in electronic conductance analysis?

    Directory of Open Access Journals (Sweden)

    Tonatiuh Rangel

    2015-06-01

    Full Text Available Using benzenediamine and benzenedithiol molecular junctions as benchmarks, we investigate the widespread analysis of the quantum transport conductance in terms of the projected density of states (PDOS onto molecular orbitals (MOs. We first consider two different methods for identifying the relevant MOs: (1 diagonalization of the Hamiltonian of the isolated molecule and (2 diagonalization of a submatrix of the junction Hamiltonian constructed by considering only basis elements localized on the molecule. We find that these two methods can lead to substantially different MOs and hence PDOS. Furthermore, within Method 1, the PDOS can differ depending on the isolated molecule chosen to represent the molecular junction (e.g., with or without dangling bonds; within Method 2, the PDOS depends on the chosen basis set. We show that these differences can be critical when the PDOS is used to provide a physical interpretation of the conductance (especially when its value is small, as it happens typically at zero bias. In this work, we propose a new approach in an attempt to reconcile the two traditional methods. Although some improvements were achieved, the main problems remain unsolved. Our results raise more general questions and doubts on a PDOS-based analysis of the conductance.

  10. PIPE-chipSAD: a pipeline for the analysis of high density arrays of bacterial transcriptomes

    Directory of Open Access Journals (Sweden)

    Silvia Bottini

    2016-12-01

    Full Text Available PIPE-chipSAD is a pipeline for bacterial transcriptome studies based on high-density microarray experiments. The main algorithm chipSAD, integrates the analysis of the hybridization signal with the genomic position of probes and identifies portions of the genome transcribing for mRNAs. The pipeline includes a procedure, align-chipSAD, to build a multiple alignment of transcripts originating in the same locus in multiple experiments and provides a method to compare mRNA expression across different conditions. Finally, the pipeline includes anno-chipSAD a method to annotate the detected transcripts in comparison to the genome annotation. Overall, our pipeline allows transcriptional profile analysis of both coding and non-coding portions of the chromosome in a single framework. Importantly, due to its versatile characteristics, it will be of wide applicability to analyse, not only microarray signals, but also data from other high throughput technologies such as RNA-sequencing.The current PIPE-chipSAD implementation is written in Python programming language and is freely available at https://github.com/silviamicroarray/chipSAD.

  11. Orthogonal experiment and analysis of power spectral density on process parameters of pitch tool polishing

    Science.gov (United States)

    Meng, Kai; Wan, Yongjian; Wu, Fan; Shen, Lijun; Wu, Hsing-Yu

    2017-02-01

    Mid to high spatial frequency error (MSFR and HSFR) should be strictly controlled in modern optical systems. Pitch tool polishing (PTP) is an effective ultra-smoothing surface manufacturing method to control MSFR and HSFR. But it is difficult to control because it is affected by a lot of factors. The present paper describes the pitch tool polishing study based on eighteen well-planned orthogonal experiments (OA18 matrix). Five main process factors (abrasive particle size, slurry concentration, pad rotation speed, acidity and polishing time) in pitch tool polishing process were investigated. In this study, power spectral density (PSD) based on Fourier analysis of surface topography data obtained by white light interferometer was used as the results of orthogonal experiments instead of material removal rate and surface roughness. A normalization method of PSD was proposed as the range analysis rule. Three parts of spatial frequency bandwidth were selected and discussed. Acidity is the most important factor in part 1 and slurry concentration is the most significant one in part 2; while acidity is the least influenced one in part 3. The result in each part was explained by two-step material removal mechanism. At last, suggestions in low and high spatial frequency are given for pitch tool polishing.

  12. Power spectrum density and experimental modal analysis of wide belt sander applied in domestic wood industry

    Institute of Scientific and Technical Information of China (English)

    WANG Zheng; ZHU Dianxiang

    2007-01-01

    This paper took the upper-lower wide belt sander B229 with four-feet wide belts,manufactured in China,as the study target.By means of framework dynamic design,we study its vibration characteristics by commencing from the place having horizontal defects and used experimental modal analysis (EMA) and power spectrum density (PSD) to observe the sanding parts and the whole machine,respectively.In the modal test,we mainly adopted the cross spots testing method to get the frequency response function of the fixed spots to every excitation vibration spot,then applied the SISO frequency response function and the frequency response function fitting method to identify and complete parameter recognition,respectively.The typical frequency response function chart of the whole machine and its sanding parts,as well as its second-order mode charts of contacting roller,were obtained.Through PSD analysis,we can get the amplitude-frequency spectrum and drive frequency.

  13. Bulk-Fill Resin Composites

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Havndrup-Pedersen, Cæcilie; Honoré, Daniel;

    2015-01-01

    the restorative procedure. The aim of this study, therefore, was to compare the depth of cure, polymerization contraction, and gap formation in bulk-fill resin composites with those of a conventional resin composite. To achieve this, the depth of cure was assessed in accordance with the International Organization...... for Standardization 4049 standard, and the polymerization contraction was determined using the bonded-disc method. The gap formation was measured at the dentin margin of Class II cavities. Five bulk-fill resin composites were investigated: two high-viscosity (Tetric EvoCeram Bulk Fill, SonicFill) and three low......-viscosity (x-tra base, Venus Bulk Fill, SDR) materials. Compared with the conventional resin composite, the high-viscosity bulk-fill materials exhibited only a small increase (but significant for Tetric EvoCeram Bulk Fill) in depth of cure and polymerization contraction, whereas the low-viscosity bulk...

  14. Propositional idea density in women's written language over the lifespan: computerized analysis.

    Science.gov (United States)

    Ferguson, Alison; Spencer, Elizabeth; Craig, Hugh; Colyvas, Kim

    2014-06-01

    The informativeness of written language, as measured by Propositional Idea Density (PD), has been shown to be a sensitive predictive index of language decline with age and dementia in previous research. The present study investigated the influence of age and education on the written language of three large cohorts of women from the general community, born between 1973 and 1978, 1946-51 and 1921-26. Written texts were obtained from the Australian Longitudinal Study on Women's Health in which participants were invited to respond to an open-ended question about their health. The informativeness of written comments of 10 words or more (90% of the total number of comments) was analyzed using the Computerized Propositional Idea Density Rater 3 (CPIDR-3). Over 2.5 million words used in 37,705 written responses from 19,512 respondents were analyzed. Based on a linear mixed model approach to statistical analysis with adjustment for several factors including number of comments per respondent and number of words per comment, a small but statistically significant effect of age was identified for the older cohort with mean age 78 years. The mean PD per word for this cohort was lower than the younger and mid-aged cohorts with mean age 27 and 53 years respectively, with mean reduction in PD 95% confidence interval (CI) of .006 (.003, .008) and .009 (.008, .011) respectively. This suggests that PD for this population of women was relatively more stable over the adult lifespan than has been reported previously even in late old age. There was no statistically significant effect of education level. Computerized analyses were found to greatly facilitate the study of informativeness of this large corpus of written language. Directions for further research are discussed in relation to the need for extended investigation of the variability of the measure for potential application to the identification of acquired language pathologies.

  15. Explosive bulk charge

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jacob Lee

    2015-04-21

    An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

  16. Estimation of Bouguer Density Precision: Development of Method for Analysis of La Soufriere Volcano Gravity Data

    Directory of Open Access Journals (Sweden)

    Hendra Gunawan

    2014-06-01

    Full Text Available http://dx.doi.org/10.17014/ijog.vol3no3.20084The precision of topographic density (Bouguer density estimation by the Nettleton approach is based on a minimum correlation of Bouguer gravity anomaly and topography. The other method, the Parasnis approach, is based on a minimum correlation of Bouguer gravity anomaly and Bouguer correction. The precision of Bouguer density estimates was investigated by both methods on simple 2D syntetic models and under an assumption free-air anomaly consisting of an effect of topography, an effect of intracrustal, and an isostatic compensation. Based on simulation results, Bouguer density estimates were then investigated for a gravity survey of 2005 on La Soufriere Volcano-Guadeloupe area (Antilles Islands. The Bouguer density based on the Parasnis approach is 2.71 g/cm3 for the whole area, except the edifice area where average topography density estimates are 2.21 g/cm3 where Bouguer density estimates from previous gravity survey of 1975 are 2.67 g/cm3. The Bouguer density in La Soufriere Volcano was uncertainly estimated to be 0.1 g/cm3. For the studied area, the density deduced from refraction seismic data is coherent with the recent Bouguer density estimates. New Bouguer anomaly map based on these Bouguer density values allows to a better geological intepretation.    

  17. Dermal digital ridge density of a penal population: Analysis of association and individualization.

    Science.gov (United States)

    Kaur, Maninder; Sharma, Krishan

    2016-11-01

    The present study is an attempt to analyze an association between dermal digital ridge density and explosive personality based on the study of 100 male prisoners and 50 controls. The control group had higher ridge density than the prisoners. Bilateral differences revealed higher ridge density on left hand than right hand in both the groups, but differences between two groups for directional asymmetry were not significant. Surface area is not correlated with ridge density in all the digits. About 50% of the variation in ridge density may be explained by a single factor which in all probability is the genetic component of variation. Ridge density cannot be used as a marker for assessing individual's height. Individuals having ridge density less than 12 ridges and higher than 15 ridges, i.e. placed on the two extremes were more likely than not to have more explosive personality.

  18. Analysis of DNA strand-specific differential expression with high density tiling microarrays

    Directory of Open Access Journals (Sweden)

    Antequera Francisco

    2010-03-01

    Full Text Available Abstract Background DNA microarray technology allows the analysis of genome structure and dynamics at genome-wide scale. Expression microarrays (EMA contain probes for annotated open reading frames (ORF and are widely used for the analysis of differential gene expression. By contrast, tiling microarrays (TMA have a much higher probe density and provide unbiased genome-wide coverage. The purpose of this study was to develop a protocol to exploit the high resolution of TMAs for quantitative measurement of DNA strand-specific differential expression of annotated and non-annotated transcripts. Results We extensively filtered probes present in Affymetrix Genechip Yeast Genome 2.0 expression and GeneChip S. pombe 1.0FR tiling microarrays to generate custom Chip Description Files (CDF in order to compare their efficiency. We experimentally tested the potential of our approach by measuring the differential expression of 4904 genes in the yeast Schizosaccharomyces pombe growing under conditions of oxidative stress. The results showed a Pearson correlation coefficient of 0.943 between both platforms, indicating that TMAs are as reliable as EMAs for quantitative expression analysis. A significant advantage of TMAs over EMAs is the possibility of detecting non-annotated transcripts generated only under specific physiological conditions. To take full advantage of this property, we have used a target-labelling protocol that preserves the original polarity of the transcripts and, therefore, allows the strand-specific differential expression of non-annotated transcripts to be determined. By using a segmentation algorithm prior to generating the corresponding custom CDFs, we identified and quantitatively measured the expression of 510 transcripts longer than 180 nucleotides and not overlapping previously annotated ORFs that were differentially expressed at least 2-fold under oxidative stress. Conclusions We show that the information derived from TMA

  19. Analysis of recoverable current from one component of magnetic flux density in MREIT and MRCDI.

    Science.gov (United States)

    Park, Chunjae; Lee, Byung Il; Kwon, Oh In

    2007-06-01

    Magnetic resonance current density imaging (MRCDI) provides a current density image by measuring the induced magnetic flux density within the subject with a magnetic resonance imaging (MRI) scanner. Magnetic resonance electrical impedance tomography (MREIT) has been focused on extracting some useful information of the current density and conductivity distribution in the subject Omega using measured B(z), one component of the magnetic flux density B. In this paper, we analyze the map Tau from current density vector field J to one component of magnetic flux density B(z) without any assumption on the conductivity. The map Tau provides an orthogonal decomposition J = J(P) + J(N) of the current J where J(N) belongs to the null space of the map Tau. We explicitly describe the projected current density J(P) from measured B(z). Based on the decomposition, we prove that B(z) data due to one injection current guarantee a unique determination of the isotropic conductivity under assumptions that the current is two-dimensional and the conductivity value on the surface is known. For a two-dimensional dominating current case, the projected current density J(P) provides a good approximation of the true current J without accumulating noise effects. Numerical simulations show that J(P) from measured B(z) is quite similar to the target J. Biological tissue phantom experiments compare J(P) with the reconstructed J via the reconstructed isotropic conductivity using the harmonic B(z) algorithm.

  20. Vibrational Spectroscopic Investigation and Conformational Analysis of Methacrylamidoantipyrine: A Comparative Density Functional Study

    Directory of Open Access Journals (Sweden)

    Özgür Alver

    2013-01-01

    Full Text Available FT-IR and Raman spectra of methacrylamidoantipyrine (MAAP have been reported in the region of 4000–10 cm−1 and 4000–100 cm−1, respectively. The optimized geometric parameters, conformational analysis, normal mode frequencies, and corresponding vibrational assignments of MAAP (C15H17N3O2 have been examined by means of density functional theory (DFT method using the Becke-3-Lee-Yang-Parr (B3LYP exchange-correlation functional and the 6-31G++(d,p basis sets. Vibrational assignments have been made on the basis of potential energy distribution (PED and the thermodynamics functions, and the highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO of MAAP have been predicted. Calculations are carried out with the possible seven (amide-1–5 and imide-1-2 conformational isomers of MAAP. Comparison between the experimental and theoretical results indicates that the B3LYP method provides satisfactory evidence for the prediction of vibrational wavenumbers, and the amide-1 conformational isomer is supposed to be the most stable form of MAAP.

  1. Parametric Power Spectral Density Analysis of Noise from Instrumentation in MALDI TOF Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    John M. Koomen

    2007-01-01

    Full Text Available Noise in mass spectrometry can interfere with identification of the biochemical substances in the sample. For example, the electric motors and circuits inside the mass spectrometer or in nearby equipment generate random noise that may distort the true shape of mass spectra. This paper presents a stochastic signal processing approach to analyzing noise from electrical noise sources (i.e., noise from instrumentation in MALDI TOF mass spectrometry. Noise from instrumentation was hypothesized to be a mixture of thermal noise, 1/f noise, and electric or magnetic interference in the instrument. Parametric power spectral density estimation was conducted to derive the power distribution of noise from instrumentation with respect to frequencies. As expected, the experimental results show that noise from instrumentation contains 1/f noise and prominent periodic components in addition to thermal noise. These periodic components imply that the mass spectrometers used in this study may not be completely shielded from the internal or external electrical noise sources. However, according to a simulation study of human plasma mass spectra, noise from instrumentation does not seem to affect mass spectra significantly. In conclusion, analysis of noise from instrumentation using stochastic signal processing here provides an intuitive perspective on how to quantify noise in mass spectrometry through spectral modeling.

  2. Quantitative, nondestructive assessment of beech scale (Hemiptera: Cryptococcidae) density using digital image analysis of wax masses.

    Science.gov (United States)

    Teale, Stephen A; Letkowski, Steven; Matusick, George; Stehman, Stephen V; Castello, John D

    2009-08-01

    Beech scale, Cryptococcus fagisuga Lindinger, is a non-native invasive insect associated with beech bark disease. A quantitative method of measuring viable scale density at the levels of the individual tree and localized bark patches was developed. Bark patches (10 cm(2)) were removed at 0, 1, and 2 m above the ground and at the four cardinal directions from 13 trees in northern New York and 12 trees in northern Michigan. Digital photographs of each patch were made, and the wax mass area was measured from two random 1-cm(2) subsamples on each bark patch using image analysis software. Viable scale insects were counted after removing the wax under a dissecting microscope. Separate regression analyses at the whole tree level for the New York and Michigan sites each showed a strong positive relationship of wax mass area with the number of underlying viable scale insects. The relationships for the New York and Michigan data were not significantly different from each other, and when pooling data from the two sites, there was still a significant positive relationship between wax mass area and the number of scale insects. The relationships between viable scale insects and wax mass area were different at the 0-, 1-, and 2-m sampling heights but do not seem to affect the relationship. This method does not disrupt the insect or its interactions with the host tree.

  3. Micro-strain, dislocation density and surface chemical state analysis of multication thin films

    Science.gov (United States)

    Jayaram, P.; Pradyumnan, P. P.; Karazhanov, S. Zh.

    2016-11-01

    Multication complex metal oxide thin films are rapidly expanding the class of materials with many technologically important applications. Herein this work, the surface of the pulsed laser deposited thin films of Zn2SnO4 and multinary compounds obtained by substitution/co-substitution of Sn4+ with In3+ and Ga3+ are studied by X-ray photoelectron emission spectroscopy (X-PES) method. Peaks corresponding to the elements of Zn, Sn, Ga, In and O on the film surface has been identified and contribution of the elements has been studied by the computer aided surface analysis (CASA) software. Binding energies, full-width at half maximum (FWHM), spin-orbit splitting energies, asymmetric peak-shape fitting parameters and quantification of elements in the films are discussed. Studies of structural properties of the films by x-ray diffraction (XRD) technique showed inverse spinel type lattice with preferential orientation. Micro-strain, dislocation density and crystallite sizes in the film surface have been estimated.

  4. Marine Traffic Density Over Port Klang, Malaysia Using Statistical Analysis of AIS Data: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Masnawi MUSTAFFA

    2016-12-01

    Full Text Available Port Klang Malaysia is the 13th busiest port in the world, the capacity at the port expected to be able to meet the demand until 2018. It is one of the busiest ports in the world and also the busiest port in Malaysia. Even though there are statistics published by Port Klang Authority showing that a lot of ships using this port, this number is only based on ships that entering Port Klang. Therefore, no study has been done to investigate on how dense the traffic is in Port Klang, Malaysia the surrounding sea including Strait of Malacca . This paper has investigated on traffic density over Port Klang Malaysia and its surrounding sea using statistical analysis from AIS data. As a preliminary study, this study only collected AIS data for 7 days to represent daily traffic weekly. As a result, an hourly number of vessels, daily number of vessels, vessels classification and sizes and also traffic paths will be plotted.

  5. Edge roughness characterization of advanced patterning processes using power spectral density analysis (PSD)

    Science.gov (United States)

    Levi, Shimon; Schwarzband, Ishai; Kris, Roman; Adan, Ofer; Shi, Elly; Zhang, Ying; Zhou, Kevin

    2016-03-01

    Self-Aligned Quadruple Patterning (SAQP) is targeted to support the sub 10nm technology nodes. It is consisted of several process steps starting with lithography and Etch to define the pattern backbone. Followed by additional set of processes based on thin-films deposition and etch that quadruple the number of patterns, shrinking pattern and pitch sizes. Pattern roughness is derived from the physical and chemical characteristics of these process steps. It is changing with each of the SAQP process steps, based on material stack and the etch process characteristics. Relative to a sub 10 nm pattern sizes pattern, edge roughness can significantly impact pattern physical dimensions. Unless controlled it can increase the variability of device electrical performance, and reduce yield. In this paper we present the SAQP process steps and roughness characterization, performed with Power Spectral Density (PSD) methodology. Experimental results demonstrates the ability of PSD analysis to sensitively reflect detailed characterization of process roughness, guiding process development improvements, and enabling roughness monitoring for production.

  6. 基于价值链的干散货航运物流发展趋势分析%The Development Trend Analysis of Dry Bulk Shipping Logistics Based on Value Chain

    Institute of Scientific and Technical Information of China (English)

    郭海涛

    2014-01-01

    文中首先根据价值链理论分析了干散货航运企业价值链的构成、企业外部价值链和内部价值链。从价值链的角度,指出现阶段干散货航运物流的发展趋势。在价值链分析的基础上,指出干散货航运企业在发展航运物流过程中应该重视的价值。%This chapter firstly according to the theory of value chain analysis of the dry bulk shipping enterprise value chain,enterprise exterior value chain and internal value chain.From the perspective of the value chain,the present stage of dry bulk shipping logistics development trend.On the basis of the value chain analysis,and points out that the dry bulk shipping enterprises in the development process should attach importance to the value of shipping logistics.

  7. Synthesis of Bulk Superconducting Magnesium Diboride

    Directory of Open Access Journals (Sweden)

    Margie Olbinado

    2002-06-01

    Full Text Available Bulk polycrystalline superconducting magnesium diboride, MgB2, samples were successfully prepared via a one-step sintering program at 750°C, in pre Argon with a pressure of 1atm. Both electrical resistivity and magnetic susceptibility measurements confirmed the superconductivity of the material at 39K, with a transition width of 5K. The polycrystalline nature, granular morphology, and composition of the sintered bulk material were confirmed using X-ray diffractometry (XRD, scanning electron microscopy (SEM, and energy dispersive X-ray analysis (EDX.

  8. Relation between Growth and Vertical Distribution of Fine Roots and Soil Density in the Weibei Loess Plateau

    Institute of Scientific and Technical Information of China (English)

    Zhao Zhong; Li Peng; Xue Wenpeng; Guo Shengwu

    2006-01-01

    The influence of woodland soil bulk density on the growth and distribution of fine root system of main planting tree species in the Weibei Loess Plateau was investigated by means of pot culture and field survey.Results indicated that in the woodland of Pinus tabulaeformis,soil bulk density increased with the depth at different sites,while in the woodland of Robinia pseudoacacia,soil bulk density was higher than that in P.tabulaeformis,and there was no clear difference across the profile.Further analysis implied that there existed negative correlations between soil bulk density and fine root length in the woodland of P.tabulaeformis.Results from pot culture indicated that although the effects of pot culture media on the free root growth and development of different tree species seedlings were different,all treated seedlings grew better in the soil matter with medium bulk density and porosity and with the biggest biomass.Bulk density of pot culture media had clear effects on the growth and development of P.tabulaeformis and R.pseudoacacia seedling roots,especially on the former,whereas it had little effect on that of Platycladus orientalis and Prunus armeniaca var.ansu,whose fine root biomass changed little in different pot culture media.

  9. Effects of Growth Hormone Replacement Therapy on Bone Mineral Density in Growth Hormone Deficient Adults: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Peng Xue

    2013-01-01

    Full Text Available Objectives. Growth hormone deficiency patients exhibited reduced bone mineral density compared with healthy controls, but previous researches demonstrated uncertainty about the effect of growth hormone replacement therapy on bone in growth hormone deficient adults. The aim of this study was to determine whether the growth hormone replacement therapy could elevate bone mineral density in growth hormone deficient adults. Methods. In this meta-analysis, searches of Medline, Embase, and The Cochrane Library were undertaken to identify studies in humans of the association between growth hormone treatment and bone mineral density in growth hormone deficient adults. Random effects model was used for this meta-analysis. Results. A total of 20 studies (including one outlier study with 936 subjects were included in our research. We detected significant overall association of growth hormone treatment with increased bone mineral density of spine, femoral neck, and total body, but some results of subgroup analyses were not consistent with the overall analyses. Conclusions. Our meta-analysis suggested that growth hormone replacement therapy could have beneficial influence on bone mineral density in growth hormone deficient adults, but, in some subject populations, the influence was not evident.

  10. Orchestrating Bulk Data Movement in Grid Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vazhkudai, SS

    2005-01-25

    Data Grids provide a convenient environment for researchers to manage and access massively distributed bulk data by addressing several system and transfer challenges inherent to these environments. This work addresses issues involved in the efficient selection and access of replicated data in Grid environments in the context of the Globus Toolkit{trademark}, building middleware that (1) selects datasets in highly replicated environments, enabling efficient scheduling of data transfer requests; (2) predicts transfer times of bulk wide-area data transfers using extensive statistical analysis; and (3) co-allocates bulk data transfer requests, enabling parallel downloads from mirrored sites. These efforts have demonstrated a decentralized data scheduling architecture, a set of forecasting tools that predict bandwidth availability within 15% error and co-allocation architecture, and heuristics that expedites data downloads by up to 2 times.

  11. Formal Difference Analysis and Unification on p-Norm Distribution Density Functions

    Institute of Scientific and Technical Information of China (English)

    LIU Zhengcai; ZHU Jianjun; WANG Huaiyu

    2006-01-01

    The cause of the formal difference of p-norm distribution density functions is analyzed, two problems in the deduction of p-norm formulating are improved, and it is proved that two different forms of p-norm distribution density functions are equivalent. This work is useful for popularization and application of the p-norm theory to surveying and mapping.

  12. Analysis of physical mechanisms underlying density-dependent transport in porous media

    NARCIS (Netherlands)

    Landman, A.J.

    2005-01-01

    In this thesis, the interaction between (large) density gradients and flow and transport in porous media is studied. Large gradients in the density of groundwater exist for example near deep salt rock formations, which are considered as possible long-term storage sites for radioactive waste. Further

  13. Analysis of compaction shock interactions during DDT of low density HMX

    Science.gov (United States)

    Rao, Pratap T.; Gonthier, Keith A.

    2017-01-01

    Deflagration-to-Detonation Transition (DDT) in confined, low density granular HMX occurs by a complex mechanism that involves compaction shock interactions within the material. Piston driven DDT experiments indicate that detonation is abruptly triggered by the interaction of a strong combustion-supported secondary shock and a piston-supported primary (input) shock, where the nature of the interaction depends on initial packing density and primary shock strength. These interactions influence transition by affecting dissipative heating within the microstructure during pore collapse. Inert meso-scale simulations of successive shock loading of low density HMX are performed to examine how dissipation and hot-spot formation are affected by the initial density, and the primary and secondary shock strengths. This information is used to formulate an ignition and burn model for low density HMX that accounts for the effect of shock densensitization on burn. Preliminary DDT predictions are presented that illustrate how primary shock strength affects the transition mechanism.

  14. Application of the quasi-spectral density function of (15)N nuclei to the selection of a motional model for model-free analysis.

    Science.gov (United States)

    Ishima, R; Yamasaki, K; Nagayama, K

    1995-12-01

    Parameters used in model-free analysis were related to simulated spectral density functions in a frequency region experimentally obtained by quasi-spectral density function analysis of (15)N nuclei. Five kinds of motional models used in recent model-free analyses were characterized by a simple classification of the experimental spectral density function. We demonstrate advantages and limitations of each of the motional models. To verify the character of the models, model selection using experimental spectral density functions was examined.

  15. Bulk viscosity, interaction and the viability of phantom solutions

    CERN Document Server

    Leyva, Yoelsy

    2016-01-01

    We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker (FRW) universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matter-dominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with $w<-1$. From the different cases that we study, the only possible scenario, with bulk viscosity and interac...

  16. Microfabricated bulk wave acoustic bandgap device

    Science.gov (United States)

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming, Carol

    2010-06-08

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  17. Development of Optimized Core Design and Analysis Methods for High Power Density BWRs

    Science.gov (United States)

    Shirvan, Koroush

    Increasing the economic competitiveness of nuclear energy is vital to its future. Improving the economics of BWRs is the main goal of this work, focusing on designing cores with higher power density, to reduce the BWR capital cost. Generally, the core power density in BWRs is limited by the thermal Critical Power of its assemblies, below which heat removal can be accomplished with low fuel and cladding temperatures. The present study investigates both increases in the heat transfer area between ~he fuel and coolant and changes in operating parameters to achieve higher power levels while meeting the appropriate thermal as well as materials and neutronic constraints. A scoping study is conducted under the constraints of using fuel with cylindrical geometry, traditional materials and enrichments below 5% to enhance its licensability. The reactor vessel diameter is limited to the largest proposed thus far. The BWR with High power Density (BWR-HD) is found to have a power level of 5000 MWth, equivalent to 26% uprated ABWR, resulting into 20% cheaper O&M and Capital costs. This is achieved by utilizing the same number of assemblies, but with wider 16x16 assemblies and 50% shorter active fuel than that of the ABWR. The fuel rod diameter and pitch are reduced to just over 45% of the ABWR values. Traditional cruciform form control rods are used, which restricts the assembly span to less than 1.2 times the current GE14 design due to limitation on shutdown margin. Thus, it is possible to increase the power density and specific power by 65%, while maintaining the nominal ABWR Minimum Critical Power Ratio (MCPR) margin. The plant systems outside the vessel are assumed to be the same as the ABWR-Il design, utilizing a combination of active and passive safety systems. Safety analyses applied a void reactivity coefficient calculated by SIMULA TE-3 for an equilibrium cycle core that showed a 15% less negative coefficient for the BWR-HD compared to the ABWR. The feedwater

  18. De novo DNA sequence driven bulk segregant analysis of Water Use Efficiency (WUE) in potato without prior knowledge of molecular markers

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sønderkær, Mads; Sørensen, Kirsten Kørup;

    2012-01-01

    concentration on leaf surface as well as temperature were analyzed and their consequences on water use efficiency were evaluated during the climate chamber experiments in 2010 and 2011. We have previously participated in development of a de novo sequence-based alternative to positional cloning (SHOREMap)2. Here....... Four bulks (two of high and two of low WUE) and the parents were subsequently sequenced to ~30x coverage. Non-random distribution of sequence read-based polymorphisms between the WUE pools and the parental pool delimited highly resolved regions on several chromosomes. Within these regions candidate...

  19. Statistical Analysis of Photopyroelectric Signals using Histogram and Kernel Density Estimation for differentiation of Maize Seeds

    Science.gov (United States)

    Rojas-Lima, J. E.; Domínguez-Pacheco, A.; Hernández-Aguilar, C.; Cruz-Orea, A.

    2016-09-01

    Considering the necessity of photothermal alternative approaches for characterizing nonhomogeneous materials like maize seeds, the objective of this research work was to analyze statistically the amplitude variations of photopyroelectric signals, by means of nonparametric techniques such as the histogram and the kernel density estimator, and the probability density function of the amplitude variations of two genotypes of maize seeds with different pigmentations and structural components: crystalline and floury. To determine if the probability density function had a known parametric form, the histogram was determined which did not present a known parametric form, so the kernel density estimator using the Gaussian kernel, with an efficiency of 95 % in density estimation, was used to obtain the probability density function. The results obtained indicated that maize seeds could be differentiated in terms of the statistical values for floury and crystalline seeds such as the mean (93.11, 159.21), variance (1.64× 103, 1.48× 103), and standard deviation (40.54, 38.47) obtained from the amplitude variations of photopyroelectric signals in the case of the histogram approach. For the case of the kernel density estimator, seeds can be differentiated in terms of kernel bandwidth or smoothing constant h of 9.85 and 6.09 for floury and crystalline seeds, respectively.

  20. Determining the von Mises stress power spectral density for frequency domain fatigue analysis including out-of-phase stress components

    NARCIS (Netherlands)

    Bonte, M.H.A.; Boer, de A.; Liebregts, R.

    2007-01-01

    This paper provides a new formula to take into account phase differences in the determination of an equivalent von Mises stress power spectral density (PSD) from multiple random inputs. The obtained von Mises PSD can subsequently be used for fatigue analysis. The formula was derived for use in the c

  1. An analysis of the temperature dependence of the electron density in CdGeAs sub 2

    CERN Document Server

    Borisenko, S I

    2001-01-01

    Analysis of temperature dependence of electron density in single crystals grown by a new method has been performed. Values of concentration of intrinsic defects and the energy of activation is calculated. It is shown, that the energy of activation has a resonant character, and concentration of intrinsic defects in the investigated range of temperatures 10-500 K considerably exceeds the concentration of electrons

  2. Association of estrogen receptor alpha gene polymorphisms with bone mineral density: a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    WANG Ke-jie; SHI Dong-quan; SUN Li-sheng; JIANG Xu; L(U) Yan-yun; DAI Jin; CHEN Dong-yang; XU Zhi-hong; JIANG Qing

    2012-01-01

    Background A number of studies have examined the association between estrogen receptor alpha (ESR-α) gene polymorphisms and bone mineral density (BMD),but previous studies of ESR-α gene Xbal (rs9340799) and Pvull (rs2234693) polymorphisms have been hampered by small sample size,regional restrictions and inconclusive results.Thus a meta-analysis is needed to assess their pooled effects.üMethods This study reviewed all published articles indexed in Pubmed using the keywords in the title or abstract.All data were extracted independently by two reviewers using a standard form,the studies were mete-analyzed and minor discrepancies were resolved by authors' discussion.Results Twenty seven eligible studies involving 8467 women and 2032 men were identified.The Xbal and Pvull polymorphisms were significantly associated with BMD of the lumbar spine.XX and PP homozygotes had a protective effect in comparison with carriers of the x and p alleles,the effects were more significant in premenopausal women or Western women.At the femoral neck,the results were different.XX served as a protective factor in postmenopausal women,Western women,Western postmenopausal women,and men,while PP was likely to serve as a risk factor in Eastern women,Eastern postmenopausal women,and men.Conclusions The Xbal polymorphism is correlated to BMD at diverse skeletal sites.PP had a protective role for the lumbar spine but might be a risk factor for the femoral neck.

  3. Status Epilepticus Induced Spontaneous Dentate Gyrus Spikes: In Vivo Current Source Density Analysis.

    Directory of Open Access Journals (Sweden)

    Sean P Flynn

    Full Text Available The dentate gyrus is considered to function as an inhibitory gate limiting excitatory input to the hippocampus. Following status epilepticus (SE, this gating function is reduced and granule cells become hyper-excitable. Dentate spikes (DS are large amplitude potentials observed in the dentate gyrus (DG of normal animals. DS are associated with membrane depolarization of granule cells, increased activity of hilar interneurons and suppression of CA3 and CA1 pyramidal cell firing. Therefore, DS could act as an anti-excitatory mechanism. Because of the altered gating function of the dentate gyrus following SE, we sought to investigate how DS are affected following pilocarpine-induced SE. Two weeks following lithium-pilocarpine SE induction, hippocampal EEG was recorded in male Sprague-Dawley rats with 16-channel silicon probes under urethane anesthesia. Probes were placed dorso-ventrally to encompass either CA1-CA3 or CA1-DG layers. Large amplitude spikes were detected from EEG recordings and subject to current source density analysis. Probe placement was verified histologically to evaluate the anatomical localization of current sinks and the origin of DS. In 9 of 11 pilocarpine-treated animals and two controls, DS were confirmed with large current sinks in the molecular layer of the dentate gyrus. DS frequency was significantly increased in pilocarpine-treated animals compared to controls. Additionally, in pilocarpine-treated animals, DS displayed current sinks in the outer, middle and/or inner molecular layers. However, there was no difference in the frequency of events when comparing between layers. This suggests that following SE, DS can be generated by input from medial and lateral entorhinal cortex, or within the dentate gyrus. DS were associated with an increase in multiunit activity in the granule cell layer, but no change in CA1. These results suggest that following SE there is an increase in DS activity, potentially arising from

  4. VOLUME STUDY WITH HIGH DENSITY OF PARTICLES BASED ON CONTOUR AND CORRELATION IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Tatyana Yu. Nikolaeva

    2014-11-01

    Full Text Available The subject of study is the techniques of particle statistics evaluation, in particular, processing methods of particle images obtained by coherent illumination. This paper considers the problem of recognition and statistical accounting for individual images of small scattering particles in an arbitrary section of the volume in case of high concentrations. For automatic recognition of focused particles images, a special algorithm for statistical analysis based on contouring and thresholding was used. By means of the mathematical formalism of the scalar diffraction theory, coherent images of the particles formed by the optical system with high numerical aperture were simulated. Numerical testing of the method proposed for the cases of different concentrations and distributions of particles in the volume was performed. As a result, distributions of density and mass fraction of the particles were obtained, and the efficiency of the method in case of different concentrations of particles was evaluated. At high concentrations, the effect of coherent superposition of the particles from the adjacent planes strengthens, which makes it difficult to recognize images of particles using the algorithm considered in the paper. In this case, we propose to supplement the method with calculating the cross-correlation function of particle images from adjacent segments of the volume, and evaluating the ratio between the height of the correlation peak and the height of the function pedestal in the case of different distribution characters. The method of statistical accounting of particles considered in this paper is of practical importance in the study of volume with particles of different nature, for example, in problems of biology and oceanography. Effective work in the regime of high concentrations expands the limits of applicability of these methods for practically important cases and helps to optimize determination time of the distribution character and

  5. Depression and suicide publication analysis, using density equalizing mapping and output benchmarking

    Directory of Open Access Journals (Sweden)

    B H Vogelzang

    2011-01-01

    Full Text Available Background: Depression is a major cause of suicide worldwide. This association has been reflected by numerous scientific publications reporting about studies to this theme. There is currently no overall evaluation of the global research activities in this field. Aim: The aim of the current study was to analyze long-term developments and recent research trends in this area. Material and Methods: We searched the Web of Science databases developed by the Thompson Institute of Scientific Information for items concerning depression and suicide published between 1900 and 2007 and analyzed the results using scientometric methods and density-equalizing calculations. Results: We found that publications on this topic increased dramatically in the time period 1990 to 2007. The comparison of the different Journals showed that the Archives of General Psychiatry had the highest average citation rate (more than twice that of any other Journal. When comparing authors, we found that not all the authors who had high h-indexes cooperated much with other authors. The analysis of countries who published papers on this topic showed that they published papers in relation to their Gross Domestic Product and Purchasing Power Parity. Among the G8 countries, Russia had the highest male suicide rate in 1999 (more than twice that of any of the other G8 countries, despite having published least papers and cooperating least with other countries among the G8. Conclusion: We conclude that, although there has been an increase in publications on this topic from 1990 to 2006, this increase is of a lower gradient than that of psoriasis and rheumatoid arthritis.

  6. Health worker densities and immunization coverage in Turkey: a panel data analysis

    Directory of Open Access Journals (Sweden)

    Yip Winnie

    2008-12-01

    Full Text Available Abstract Background Increased immunization coverage is an important step towards fulfilling the Millennium Development Goal of reducing childhood mortality. Recent cross-sectional and cross-national research has indicated that physician, nurse and midwife densities may positively influence immunization coverage. However, little is known about relationships between densities of human resources for health (HRH and vaccination coverage within developing countries and over time. The present study examines HRH densities and coverage of the Expanded Programme on Immunization (EPI in Turkey during the period 2000 to 2006. Methods The study is based on provincial-level data on HRH densities, vaccination coverage and provincial socioeconomic and demographic characteristics published by the Turkish government. Panel data regression methodologies (random and fixed effects models are used to analyse the data. Results Three main findings emerge: (1 combined physician, nurse/midwife and health officer density is significantly associated with vaccination rates – independent of provincial female illiteracy, GDP per capita and land area – although the association was initially positive and turned negative over time; (2 HRH-vaccination rate relationships differ by cadre of health worker, with physician and health officers exhibiting significant relationships that mirror those for aggregate density, while nurse/midwife densities are not consistently significant; (3 HRH densities bear stronger relationships with vaccination coverage among more rural provinces, compared to those with higher population densities. Conclusion We find evidence of relationships between HRH densities and vaccination rates even at Turkey's relatively elevated levels of each. At the same time, variations in results between different empirical models suggest that this relationship is complex, affected by other factors that occurred during the study period, and warrants further

  7. Estimation of current density distribution of PAFC by analysis of cell exhaust gas

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S.; Seya, A. [Fuji Electric Co., Ltd., Ichihara-shi (Japan); Asano, A. [Fuji Electric Corporate, Ltd., Yokosuka-shi (Japan)

    1996-12-31

    To estimate distributions of Current densities, voltages, gas concentrations, etc., in phosphoric acid fuel cell (PAFC) stacks, is very important for getting fuel cells with higher quality. In this work, we leave developed a numerical simulation tool to map out the distribution in a PAFC stack. And especially to Study Current density distribution in the reaction area of the cell, we analyzed gas composition in several positions inside a gas outlet manifold of the PAFC stack. Comparing these measured data with calculated data, the current density distribution in a cell plane calculated by the simulation, was certified.

  8. 核电建设阶段大宗材料采购缺失分析和改进建议%Analysis and Improvement Suggestion for the Lack of Bulk Material Procurement during the Construction of Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    李冠英; 顾健

    2015-01-01

    Aiming at the importance and influence of lack of procurement for bulk materials during nuclear power plant construction, the design, procurement and construction management for bulk material are analyzed. Through analysis, referring to the problems during design, procurement and construction management, suggestions are given to countermeasures for all stage of work, with an aim to increase procurement efficiency and decrease the lack of procurement for bulk materials.%文章针对核电建设阶段大宗材料采购缺失重要性及缺失影响,进行了大宗材料采购时设计、采购、施工管理方面问题的分析.通过分析,针对大宗材料采购时设计、采购、施工管理问题提出了各阶段的工作对策,旨在提高采购效率、减小大宗材料的缺失率.

  9. Power Spectral Density Analysis of Electrodermal Activity for Sympathetic Function Assessment.

    Science.gov (United States)

    Posada-Quintero, Hugo F; Florian, John P; Orjuela-Cañón, Alvaro D; Aljama-Corrales, Tomas; Charleston-Villalobos, Sonia; Chon, Ki H

    2016-10-01

    Time-domain features of electrodermal activity (EDA), the measurable changes in conductance at the skin surface, are typically used to assess overall activation of the sympathetic system. These time domain features, the skin conductance level (SCL) and the nonspecific skin conductance responses (NS.SCRs), are consistently elevated with sympathetic nervous arousal, but highly variable between subjects. A novel frequency-domain approach to quantify sympathetic function using the power spectral density (PSD) of EDA is proposed. This analysis was used to examine if some of the induced stimuli invoke the sympathetic nervous system's dynamics which can be discernible as a large spectral peak, conjectured to be present in the low frequency band. The resulting indices were compared to the power of low-frequency components of heart rate variability (HRVLF) time series, as well as to time-domain features of EDA. Twelve healthy subjects were subjected to orthostatic, physical and cognitive stress, to test these techniques. We found that the increase in the spectral powers of the EDA was largely confined to 0.045-0.15 Hz, which is in the prescribed band for HRVLF. These low frequency components are known to be, in part, influenced by the sympathetic nervous dynamics. However, we found an additional 5-10% of the spectral power in the frequency range of 0.15-0.25 Hz with all three stimuli. Thus, dynamics of the normalized sympathetic component of the EDA, termed EDASympn, are represented in the frequency band 0.045-0.25 Hz; only a small amount of spectral power is present in frequencies higher than 0.25 Hz. Our results showed that the time-domain indices (the SCL and NS.SCRs), and EDASympn, exhibited significant increases under orthostatic, physical, and cognitive stress. However, EDASympn was more responsive than the SCL and NS.SCRs to the cold pressor stimulus, while the latter two were more sensitive to the postural and Stroop tests. Additionally, EDASympn exhibited an

  10. Snakebite Envenoming – A Combined Density Equalizing Mapping and Scientometric Analysis of the Publication History

    Science.gov (United States)

    Groneberg, David A.; Geier, Victoria; Klingelhöfer, Doris; Gerber, Alexander

    2016-01-01

    Estimates suggest that more than 25,000 to 125,000 people die annually from snakebite envenomation worldwide. In contrast to this major disease burden, thorough bibliometric studies do not exist so far that illustrate the overall research activity over a long time span. Therefore, the NewQIS-platform conducted an analysis on snakebite envenoming using the Thomson Reuters database Web of Science. To determine and assess changes regarding the scientific activities and to specifically address the more recent situation we analyzed two time intervals (t). During the first time interval from 1900 to 2007 (t1) 13,015 publications (p) were identified. In the following period (2008–2016 = t2) 4,982 publications were identified by the same search strategy. They originate from 114 (t1) respectively 121 countries (t2), with the USA (p = 3518), Brazil (p = 1100) and Japan (p = 961) being most productive in the first period, and the USA (p = 1087), Brazil (p = 991) and China (p = 378) in the second period, respectively. Setting the publication numbers in relation to GDP/capita, Brazil leads with 92 publications per 10,000 Int$GDP/capita, followed by India with 79 publications per 10000 Int$GDP/capita (t1). Comparing the country’s publication activity with the Human Development Index level indicates that the majority of the publications is published by highly developed countries. When calculating the average citation rates (citations per published item = CR) mainly European countries show the highest ranks: From 1900–2007 Sweden ranks first with a CR = 27, followed by the Netherlands (CR = 24.8), Switzerland (CR = 23), Spain, Austria and the USA (CR = 22). From 2008 to 2016 the highest rate achieves Switzerland with a value of 24.6, followed by Belgium (CR = 18.1), Spain (CR = 16.7), Costa Rica (CR = 14.9) and Netherlands (CR = 14). Compared with this, the USA was placed at rank 13 (CR = 9,5). In summary, the present study represents the first density-equalizing map

  11. Snakebite Envenoming - A Combined Density Equalizing Mapping and Scientometric Analysis of the Publication History.

    Science.gov (United States)

    Groneberg, David A; Geier, Victoria; Klingelhöfer, Doris; Gerber, Alexander; Kuch, Ulrich; Kloft, Beatrix

    2016-11-01

    Estimates suggest that more than 25,000 to 125,000 people die annually from snakebite envenomation worldwide. In contrast to this major disease burden, thorough bibliometric studies do not exist so far that illustrate the overall research activity over a long time span. Therefore, the NewQIS-platform conducted an analysis on snakebite envenoming using the Thomson Reuters database Web of Science. To determine and assess changes regarding the scientific activities and to specifically address the more recent situation we analyzed two time intervals (t). During the first time interval from 1900 to 2007 (t1) 13,015 publications (p) were identified. In the following period (2008-2016 = t2) 4,982 publications were identified by the same search strategy. They originate from 114 (t1) respectively 121 countries (t2), with the USA (p = 3518), Brazil (p = 1100) and Japan (p = 961) being most productive in the first period, and the USA (p = 1087), Brazil (p = 991) and China (p = 378) in the second period, respectively. Setting the publication numbers in relation to GDP/capita, Brazil leads with 92 publications per 10,000 Int$GDP/capita, followed by India with 79 publications per 10000 Int$GDP/capita (t1). Comparing the country's publication activity with the Human Development Index level indicates that the majority of the publications is published by highly developed countries. When calculating the average citation rates (citations per published item = CR) mainly European countries show the highest ranks: From 1900-2007 Sweden ranks first with a CR = 27, followed by the Netherlands (CR = 24.8), Switzerland (CR = 23), Spain, Austria and the USA (CR = 22). From 2008 to 2016 the highest rate achieves Switzerland with a value of 24.6, followed by Belgium (CR = 18.1), Spain (CR = 16.7), Costa Rica (CR = 14.9) and Netherlands (CR = 14). Compared with this, the USA was placed at rank 13 (CR = 9,5). In summary, the present study represents the first density-equalizing map projection

  12. Short communication: investigation of Coxiella burnetii occurrence in dairy sheep flocks by bulk-tank milk analysis and antibody level determination.

    Science.gov (United States)

    García-Pérez, A L; Astobiza, I; Barandika, J F; Atxaerandio, R; Hurtado, A; Juste, R A

    2009-04-01

    To estimate the prevalence of Coxiella burnetii in the dairy sheep population from the Basque Country (northern Spain), a study was carried out combining molecular and serological techniques. First, bulk-tank milk samples from 154 flocks belonging to the Latxa Breed Farmers Association were analyzed by PCR, with 22% of flocks testing positive for C. burnetii. Then, a selection of 34 flocks (7 PCR positive and 17 negative) was investigated for the presence of serum antibodies by ELISA test on 1,011 ewes (approximately 30 ewes per flock). A total of 8.9% of the animals were seropositive, 67.6% of the flocks had at least one seropositive animal, but only in 14.7% of them was seroprevalence greater than 25%. Older ewes showed a significantly greater prevalence (17.5%) compared with yearlings (7.5%) or replacement lambs (1.5%). A marginally significant association was found between seroprevalence and PCR detection of C. burnetii in bulk-tank milk. The widespread distribution of C. burnetii in the region advocates for the implementation of Q fever control strategies and highlights the potential risk of sheep as a reservoir and infection source for other domestic and wildlife species and the human population.

  13. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-09-15

    Contrary to other claims, we argue that bulk viscosity associated with the interactions of non- relativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk-viscosity effects of a weakly interacting mixture of relativistic and nonrelativistic particles.

  14. Brane Couplings from Bulk Loops

    OpenAIRE

    Georgi, Howard; Grant, Aaron K.; Hailu, Girma

    2000-01-01

    We compute loop corrections to the effective action of a field theory on a five-dimensional $S_1/Z_2$ orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by four-dimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings.

  15. Granular packing influences the bulk density of DDGS

    Science.gov (United States)

    As the quantity of ethanol produced continues to increase, the amount of distillers dried grains with solubles (DDGS), the primary coproduct of ethanol manufacturing, has become more widely available. Currently, the main consumer of DDGS is the livestock industry, but new value added uses are on th...

  16. Recurrence quantification analysis applied to spatiotemporal pattern analysis in high-density mapping of human atrial fibrillation.

    Science.gov (United States)

    Zeemering, Stef; Bonizzi, Pietro; Maesen, Bart; Peeters, Ralf; Schotten, Ulrich

    2015-01-01

    Spatiotemporal complexity of atrial fibrillation (AF) patterns is often quantified by annotated intracardiac contact mapping. We introduce a new approach that applies recurrence plot (RP) construction followed by recurrence quantification analysis (RQA) to epicardial atrial electrograms, recorded with a high-density grid of electrodes. In 32 patients with no history of AF (aAF, n=11), paroxysmal AF (PAF, n=12) and persistent AF (persAF, n=9), RPs were constructed using a phase space electrogram embedding dimension equal to the estimated AF cycle length. Spatial information was incorporated by 1) averaging the recurrence over all electrodes, and 2) by applying principal component analysis (PCA) to the matrix of embedded electrograms and selecting the first principal component as a representation of spatial diversity. Standard RQA parameters were computed on the constructed RPs and correlated to the number of fibrillation waves per AF cycle (NW). Averaged RP RQA parameters showed no correlation with NW. Correlations improved when applying PCA, with maximum correlation achieved between RP threshold and NW (RR1%, r=0.68, p <; 0.001) and RP determinism (DET, r=-0.64, p <; 0.001). All studied RQA parameters based on the PCA RP were able to discriminate between persAF and aAF/PAF (DET persAF 0.40 ± 0.11 vs. 0.59 ± 0.14/0.62 ± 0.16, p <; 0.01). RP construction and RQA combined with PCA provide a quick and reliable tool to visualize dynamical behaviour and to assess the complexity of contact mapping patterns in AF.

  17. Breast Density Analysis with Automated Whole-Breast Ultrasound: Comparison with 3-D Magnetic Resonance Imaging.

    Science.gov (United States)

    Chen, Jeon-Hor; Lee, Yan-Wei; Chan, Si-Wa; Yeh, Dah-Cherng; Chang, Ruey-Feng

    2016-05-01

    In this study, a semi-automatic breast segmentation method was proposed on the basis of the rib shadow to extract breast regions from 3-D automated whole-breast ultrasound (ABUS) images. The density results were correlated with breast density values acquired with 3-D magnetic resonance imaging (MRI). MRI images of 46 breasts were collected from 23 women without a history of breast disease. Each subject also underwent ABUS. We used Otsu's thresholding method on ABUS images to obtain local rib shadow information, which was combined with the global rib shadow information (extracted from all slice projections) and integrated with the anatomy's breast tissue structure to determine the chest wall line. The fuzzy C-means classifier was used to extract the fibroglandular tissues from the acquired images. Whole-breast volume (WBV) and breast percentage density (BPD) were calculated in both modalities. Linear regression was used to compute the correlation of density results between the two modalities. The consistency of density measurement was also analyzed on the basis of intra- and inter-operator variation. There was a high correlation of density results between MRI and ABUS (R(2) = 0.798 for WBV, R(2) = 0.825 for PBD). The mean WBV from ABUS images was slightly smaller than the mean WBV from MR images (MRI: 342.24 ± 128.08 cm(3), ABUS: 325.47 ± 136.16 cm(3), p MRI: 24.71 ± 15.16%, ABUS: 28.90 ± 17.73%, p breast density measurement variation between the two modalities. Our results revealed a high correlation in WBV and BPD between MRI and ABUS. Our study suggests that ABUS provides breast density information useful in the assessment of breast health.

  18. THE NORMAL BIVARIATE DENSITY FUNCTION AND ITS APPLICATIONS TO WEAPON SYSTEMS ANALYSIS, A REVIEW

    Science.gov (United States)

    The normal bivariate density function is derived from a priori considerations. It is discussed in terms of probability area in a plane, and as a...correlation surface. Several numerical methods of solving the normal bivariate distribution double integral are presented, and a curve is included for...given specific mathematical treatment. An Appendix examines the elliptical properties of normally correlated distributions. The investigation has resulted in a reference paper for the normal bivariate density function.

  19. Magnetic resonance imaging. Density equalizing mapping analysis of global research architecture; Magnetresonanztomographie. Eine Density-equalizing-mapping-Analyse der globalen Forschungsarchitektur

    Energy Technology Data Exchange (ETDEWEB)

    Ohlendorf, D.; Schwarze, B.; Groneberg, D.A.; Schwarzer, M. [Goethe-Universitaet Frankfurt/M, Institut fuer Arbeitsmedizin, Sozialmedizin und Umweltmedizin, Frankfurt/M (Germany)

    2015-09-15

    Despite the great medical importance, there is still no comprehensive scientometric analysis regarding the results of magnetic resonance imaging (MRI) and the development of the importance for the healthcare system. This paper evaluated and analyzed the entire research publication results on the topic of MRI for the period 1981-2007 based on scientometric methods and parameters. A scientometric analysis (database: ISI Web of Science 1981-2007, search terms MRI and magnetic resonance imaging) was performed. The following parameters were analyzed: number of publications, countries of publication, number of citations, citation rate and collaborations, using various analytical and display techniques, including density equalizing map projections. Most of the 49,122 publications on MRI could be attributed to the USA (32.5 %), which also has the most cooperative collaborations. Within Europe, Germany (10.3 %) is the country with the highest number of publications followed by the UK (9.3 %). The western industrialized nations dominate over the rest of the world in terms of scientific developments of MRI. The thematic focus of the publications lies in the fields of radiology and neuroscience. In addition to the journal Neurology most scientific articles were published in Magnetic Resonance in Medicine and Circulation. The results show that the current trend is continuing and the scientific interest in MRI is continuously increasing. (orig.) [German] Trotz der grossen medizinischen Bedeutung existiert bis heute keine umfassende szientometrische Analyse bzgl. der Forschungsergebnisse zur Magnetresonanztomographie (MRT) und der Entwicklung ihrer Bedeutung fuer das Gesundheitssystem. Im vorliegenden Beitrag soll anhand szientometrischer Methoden und Parameter das gesamte Forschungsaufkommen zum Thema MRT fuer den Zeitraum 1981-2007 evaluiert und analysiert werden. Es wurde eine szientometrische Analyse (Datenbank: ISI-Web of Science, 1981-2007; Suchterm &apos

  20. Analysis of the H-mode density limit in the ASDEX upgrade tokamak using bolometry

    Energy Technology Data Exchange (ETDEWEB)

    Bernert, Matthias

    2013-10-23

    The high confinement mode (H-mode) is the operational scenario foreseen for ITER, DEMO and future fusion power plants. At high densities, which are favourable in order to maximize the fusion power, a back transition from the H-mode to the low confinement mode (L-mode) is observed. This H-mode density limit (HDL) occurs at densities on the order of, but below, the Greenwald density. In this thesis, the HDL is revisited in the fully tungsten walled ASDEX Upgrade tokamak (AUG). In AUG discharges, four distinct operational phases were identified in the approach towards the HDL. First, there is a stable H-mode, where the plasma density increases at steady confinement, followed by a degrading H-mode, where the core electron density is fixed and the confinement, expressed as the energy confinement time, reduces. In the third phase, the breakdown of the H-mode and transition to the L-mode, the overall electron density is fixed and the confinement decreases further, leading, finally, to an L-mode, where the density increases again at a steady confinement at typical L-mode values until the disruptive Greenwald limit is reached. These four phases are reproducible, quasi-stable plasma regimes and provide a framework in which the HDL can be further analysed. Radiation losses and several other mechanisms, that were proposed as explanations for the HDL, are ruled out for the current set of AUG experiments with tungsten walls. In addition, a threshold of the radial electric field or of the power flux into the divertor appears to be responsible for the final transition back to L-mode, however, it does not determine the onset of the HDL. The observation of the four phases is explained by the combination of two mechanisms: a fueling limit due to an outward shift of the ionization profile and an additional energy loss channel, which decreases the confinement. The latter is most likely created by an increased radial convective transport at the edge of the plasma. It is shown that the

  1. Calculated Bulk Properties of the Actinide Metals

    DEFF Research Database (Denmark)

    Skriver, Hans Lomholt; Andersen, O. K.; Johansson, B.

    1978-01-01

    Self-consistent relativistic calculations of the electronic properties for seven actinides (Ac-Am) have been performed using the linear muffin-tin orbitals method within the atomic-sphere approximation. Exchange and correlation were included in the local spin-density scheme. The theory explains...... the variation of the atomic volume and the bulk modulus through the 5f series in terms of an increasing 5f binding up to plutonium followed by a sudden localisation (through complete spin polarisation) in americium...

  2. Bulk Stable Isotope Analysis of Carbon from Solids and Liquids using an Elemental Analyzer Coupled to a Wavelength-Scanned Cavity Ring-Down Spectrophotometer

    Science.gov (United States)

    Saad, N.; Rella, C.; van Pelt, A.

    2009-04-01

    We report here on the novel employment of a small footprint Wavelength-Scanned Cavity Ring-Down Spectrometer (WS-CRDS) interfaced to an elemental analyzer for the measurement of the bulk isotopic carbon signature in plants and food products. The current system provides an inexpensive alternative with unparalleled ease-of-use as compared to standard methods using the more complex analytical instrumentation of isotope ratio mass spectrometry. A precision of carbon isotopic ratio measurements of less than 1 permil was achieved in minutes of measurement time. Such precision readily distinguishes the isotopic carbon signatures of a variety of environmental and agricultural products from different origins, providing information about food authenticity and climate changes effect on plant physiology.

  3. A Detailed Numerical Analysis of Asymmetrical Density Distribution in Saturn's F ring During an Encounter with Prometheus

    CERN Document Server

    Sutton, Phil J

    2013-01-01

    Saturn's rings, reminiscent of an early Solar System present a unique opportunity to investigate experimentally some mechanisms thought to be responsible for planet and planetesimal formation in protoplanetary discs. Here we extended the comparison of our numerical models of Prometheus encountering the F ring employing non-interacting and interacting particles. Higher resolution analysis revealed that the density increases known to exist at channel edges is more complex and localised than previously thought. Asymmetry between density increases on channel edges revealed that the channel edge facing way from Prometheus to be the most stable but with lowest maximum increases. However, on the channel edge facing Prometheus the interacting model showed large chaotic fluctuations in the maximum density of some clumps, much larger than those of the other channel. The likely cause of this asymmetry is a variance in localised turbulence introduced into the F ring by Prometheus. High resolution velocity dispersion maps...

  4. Exploration of diffusion kernel density estimation in agricultural drought risk analysis: a case study in Shandong, China

    Directory of Open Access Journals (Sweden)

    W. Chen

    2015-11-01

    Full Text Available Drought caused the most widespread damage in China, making up over 50 % of the total affected area nationwide in recent decades. In the paper, a Standardized Precipitation Index-based (SPI-based drought risk study is conducted using historical rainfall data of 19 weather stations in Shandong province, China. Kernel density based method is adopted to carry out the risk analysis. Comparison between the bivariate Gaussian kernel density estimation (GKDE and diffusion kernel density estimation (DKDE are carried out to analyze the effect of drought intensity and drought duration. The results show that DKDE is relatively more accurate without boundary-leakage. Combined with the GIS technique, the drought risk is presented which reveals the spatial and temporal variation of agricultural droughts for corn in Shandong. The estimation provides a different way to study the occurrence frequency and severity of drought risk from multiple perspectives.

  5. Chemical bonding and charge density distribution analysis of undoped and lanthanum doped barium titanate ceramics

    Indian Academy of Sciences (India)

    J MANGAIYARKKARASI; R SARAVANAN; MUKHLIS M ISMAIL

    2016-12-01

    A-site deficient, Lanthanum substituted Ba1−xLa2x/3TiO3 (x=0.000, 0.005, 0.015, 0.020 and 0.025) ceramics have been synthesized by chemical route. The effects of lanthanum dopant on the BaTiO3 lattice and the electron density distributions in the unit cell of the samples were investigated. Structural studies suggested the reduction in cell parameters and shrinkage in cell volume with the increase in lanthanum content. Chemical bonding and electron density distributions were examined through high resolution maximum entropy method (MEM). The mid bond electron density values revealed the enhancement of covalent nature between titanium and oxygen ions and predominant ionic nature between barium and oxygen ions. Average grain sizes were estimated for the undoped and doped samples. SEM investigations showed the existence of smaller grains with large voids in between them.

  6. Analysis of Bone Mineral Density and Related Factors after Pelvic Radiotherapy in Patients with Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Sun Shin; Jeung, Tae Sig [Kosin University College of Medicine, Busan (Korea, Republic of)

    2009-03-15

    This study was designed to evaluate the effects on bone mineral density (BMD) and related factors according to the distance from the radiation field at different sites. This study was conducted on patients with uterine cervical cancer who received pelvic radiotherapy. We selected 96 patients with cervical cancer who underwent determination of BMD from November 2002 to December 2006 after pelvic radiotherapy at Kosin University Gospel Hospital. The T-score and Z-score for the first lumbar spine (L1), fourth lumbar spine (L4) and femur neck (F) were analyzed to determine the difference in BMD among the sites by the use of ANOVA and the post-hoc test. The study subjects were evaluated for age, body weight, body mass index (BMI), post-radiotherapy follow-up duration, intracavitary radiotherapy (ICR) and hormonal replacement therapy (HRT). Association between the characteristics of the study subjects and T-score for each site was evaluated by the use of Pearson's correlation and multiple regression analysis. The average T-score for all ages was -1.94 for the L1, -0.42 for the L4 and -0.53 for the F. The average Z-score for all ages was -1.11 for the L1, -0.40 for the L4 and -0.48 for the F. The T-score and Z-score for the L4 and F were significantly different from the scores for the L1 (p<0.05). There was no significant difference between the L4 and F. Results for patients younger than 60 years were the same as for all ages. Age and ICR were negatively correlated and body weight and HRT were positively correlated with the T-score for all sites (p<0.05). BMI was positively correlated with the T-score for the L4 and F (p<0.05). Based on the use of multiple regression analysis, age was negatively associated with the T-score for the L1 and F and was positively correlated for the L4 (p<0.05). Body weight was positively associated with the T-score for all sites (p<0.05). ICR was negatively associated with the T-score for the L1 (p<0.05). HRT was positively associated

  7. Pseudo-Riemannian Universe from Euclidean bulk

    CERN Document Server

    Vasilić, Milovan

    2015-01-01

    I develop the idea that our world is a brane-like object embedded in Euclidean bulk. In its ground state, the brane constituent matter is assumed to be homogeneous and isotropic, and of negligible influence on the bulk geometry. No action functional is initially specified. Instead, the brane dynamics is derived from the universally valid stress-energy conservation equations. The present work studies the cosmology of a $3$-sphere in the $5$-dimensional Euclidean bulk. It is shown that the conventional equation of state $p=\\alpha\\rho$ is universal in the sector of small energy densities, and so is the resulting brane dynamics. The inequality $\\alpha<0$ is found to be a necessary condition for the existence of a stable ground state of the Universe. It is demonstrated that the generic braneworld physics rules out the Big Bang cosmology, and in that matter, any cosmology of finite lifetime. I also demonstrate that stable brane vibrations satisfy Klein-Gordon-like equation with an effective metric of Minkowski s...

  8. Bulk viscous cosmology in early Universe

    Indian Academy of Sciences (India)

    C P Singh

    2008-07-01

    The effect of bulk viscosity on the early evolution of Universe for a spatially homogeneous and isotropic Robertson-Walker model is considered. Einstein's field equations are solved by using `gamma-law' equation of state = ( - 1)ρ, where the adiabatic parameter gamma () depends on the scale factor of the model. The `gamma' function is defined in such a way that it describes a unified solution of early evolution of the Universe for inflationary and radiation-dominated phases. The fluid has only bulk viscous term and the coefficient of bulk viscosity is taken to be proportional to some power function of the energy density. The complete general solutions have been given through three cases. For flat space, power-law as well as exponential solutions are found. The problem of how the introduction of viscosity affects the appearance of singularity, is briefly discussed in particular solutions. The deceleration parameter has a freedom to vary with the scale factor of the model, which describes the accelerating expansion of the Universe.

  9. Molar Volume Analysis of Molten Ni-Al-Co Alloy by Measuring the Density

    Institute of Scientific and Technical Information of China (English)

    XIAO Feng; FANG Liang; FU Yuechao; YANG Lingchuan

    2004-01-01

    The density of molten Ni-Al-Co alloys was measured in the temperature range of 1714~1873K using a modified pycnometric method, and the molar volume of molten alloys was analyzed. The density of molten Ni-Al-Co alloys was found to decrease with increasing temperature and Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys increases with increasing Co concentration in alloys. The molar volume of molten Ni-Al-Co alloys shows a negative deviation from the linear molar volume.

  10. Analysis of charge photogeneration as a key determinant of photocurrent density in polymer: fullerene solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Tracey M.; Shoaee, Safa; Soon, Ying W.; Durrant, James R. [Centre for Plastic Electronics, Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Ballantyne, Amy; Nelson, Jenny [Centre for Plastic Electronics, Department of Physics, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Duffy, Warren; Heeney, Martin; McCulloch, Iain [Centre for Plastic Electronics, Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Merck Chemicals, Chilworth Science Park, Southampton SO16 7QD (United Kingdom)

    2010-12-07

    Charge photogeneration: The correlation between the efficiency of photogeneration of dissociated polarons and photocurrent densities for organic solar cells based on polymer:fullerene blend films is investigated. Optical assays of polaron yield measured in films without electrodes show a remarkably clear correlation with short circuit density and quantum yield measured in complete devices. For the blend films studied herein, the primary determinant of photocurrent generation is the efficiency of dissociation of photogenerated charges away from the polymer/fullerene interface and the primary loss pathway is geminate recombination. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. A simple analysis of halo density profiles using gravitational lensing time delays

    OpenAIRE

    2006-01-01

    Gravitational lensing time delays depend upon the Hubble constant and the density distribution of the lensing galaxies. This allows one to either model the lens and estimate the Hubble constant, or to use a prior on the Hubble constant from other studies and investigate what the preferred density distribution is. Some studies have required compact dark matter halos (constant M/L ratio) in order to reconcile gravitational lenses with the HST/WMAP value of the Hubble constant (72 +/- 8 km/s /Mp...

  12. Measurement and Analysis of Density of Molten Ni-W Alloys

    Institute of Scientific and Technical Information of China (English)

    FANG Liang; XIAO Feng; TAO Zainan; MuKai Kusuhiro

    2005-01-01

    The density of molten Ni-W alloys was measured with a modified pycnometric method. It is found that the density of the molten Ni- W alloys decreases with temperature rising, but increases with the increase of tungsten concentration in the alloys. The molar volume of molten Ni- W binary alloys increases with the increase of temperature and tungsten concentration. The partial molar volume of tungsten in liquid Ni- W binary alloy has been calculated approximately as ( - 1.59+ 5.64 × 10-3 T) × 10-6m3 ·mol-1.

  13. ANALYSIS OF WARP TENSION DURING WEAVING FABRIC WITH VARIABLE WEFT DENSITY

    Directory of Open Access Journals (Sweden)

    Yıldıray TURHAN

    2004-03-01

    Full Text Available In this study, warp tension change has been studied by changing weft density from a lower to a higher value in a weaving machine with electronic take up and electronic let off motions. For this purpose firstly, warp tension and cloth fell distance were measured at certain intervals from the beginning of weaving with a new weft density. Secondly, the length of fabric woven until the cloth fell reached its steady state value was determined. Finally, the warp tension measured until the steady state cloth fell values was analysed.

  14. Stochastic analysis of the effects of fluid density and viscosity variability on macrodispersion in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Welty, C. (Drexel Univ., Philadelphia, PA (United States)); Gelhar, L.W. (Massachusetts Inst. of Tech., Cambridge (United States))

    1991-08-01

    Both porous medium heterogeneities and fluid density and viscosity contrasts affect solute transport in miscible fluid displacement. The effect of interaction of these processes on large-scale mixing are evaluated using spectral-based perturbation theory. A three-dimensional, statistically isotropic, exponential log permeability autocovariance is used to represent the spatial variability of the porous medium. State equations linearly relating log density and log viscosity perturbations to concentration perturbations represent the density and viscosity variability and strongly couple the flow and solute transport perturbation equations. Analytical expressions for longitudinal macrodispersivity, derived for one-dimensional mean solute transport, are functionally dependent on mean displacement distance, mean concentration and concentration gradient, density and viscosity differences, mean velocity, gravity, and correlation scale and variance of the log permeability process. Transient analysis shows that longitudinal macrodispersivity grows exponentially in time (or mean displacement distance) without bound for the case where instabilities due to viscous or gravity fingering arise (the unstable or fingering case) and that it grows at early time then decreases exponentially to an asymptotic value close to that of local dispersivity for the case where density or viscosity contrasts produce a stabilizing effect (the stable case).

  15. Factorial analysis on forest canopy density restoration in the burned area of northern Great Xing'an Mountains, China

    Institute of Scientific and Technical Information of China (English)

    XIEFu-ju; XIAODu-ning; LIXiu-zhen; WANGXu-gao; SHIBao-dong

    2005-01-01

    The restoration of forest landscape has drawn much attention since the catastrophic fire took place on the northern slope of Great Xing'an Mountains in 1987. Forest canopy density, which has close relation to forest productivity, was selected as a key factor to find how much the forest quality was changed 13 years after fire, and how fire severity, regeneration way and terrain factors influenced the restoration of forest canopy density, based on forest inventory data in China, and using Kendall Bivariate Correlation Analysis, and Distances Correlation Analysis. The results showed that fire severity which was inversely correlated with forest canopy density grade was an initial factor among all that selected. Regeneration way which did not remarkably affect forest canopy density restoration in short period, may shorten the cycle of forest succession and promote the forest productivity of conophorium in the future, Among the three terrain factors, the effect of slope was the strongest, the position on slope was the second and the aspect was the last.

  16. Charm mass effects in bulk channel correlations

    CERN Document Server

    Burnier, Y

    2013-01-01

    The bulk viscosity of thermalized QCD matter at temperatures above a few hundred MeV could be significantly influenced by charm quarks because their contribution arises four perturbative orders before purely gluonic effects. In an attempt to clarify the challenges of a lattice study, we determine the relevant imaginary-time correlator (of massive scalar densities) up to NLO in perturbation theory, and compare with existing data. We find discrepancies much larger than in the vector channel; this may hint, apart from the importance of taking a continuum limit, to larger non-perturbative effects in the scalar channel. We also recall how a transport peak related to the scalar density spectral function encodes non-perturbative information concerning the charm quark chemical equilibration rate close to equilibrium.

  17. The (Anomalous) Hall Magnetometer as an Analysis Tool for High Density Recording Media

    NARCIS (Netherlands)

    Haan, de S.; Lodder, J.C.

    1991-01-01

    In this work an evaluation tool for the characterization of high-density recording thin film media is discussed. The measurement principles are based on the anomalous and the planar Hall effect. We used these Hall effects to characterize ferromagnetic Co-Cr films and Co/Pd multilayers having perpend

  18. Analysis of renal cyst of high density containing proteinaceous fluid: report of 6 cases

    Institute of Scientific and Technical Information of China (English)

    Jin Wen; Han zhong Li; He Xiao

    2008-01-01

    Objective:To investigate clinical features and imageology of renal cysts of high density, containing proteinaceous fluid and increase the diagnosis and treatment level of this special type renal cyst. Methods:Six cases were proven to be renal cysts of high density(pathologically) from 2002 to 2007 were reviewed. Among 6 cases, 1 was in the upper pole of kidney, 4 were medial and 1 was located in the anus perineum. All were 2-5 cm in size. Ultrasonography(US) excretory unognaphy, multiphase CT and renal angiography DSA imaging was performed for preoperative diagnosis. The preoperative diagnosis found renal neoplasms in 4 and renal cysts in 2. All of them were operated by partial nephrectomy. Results:All of the 6 renal high density renal masses were reseoted surgically, which were proved pathologically to be renal cysts; high density present. All of them contained proteinaceous fluid with benign cyst walls on histologic examination. No recurrence was seen in any of these cases during a long follow-up. Conclusion:CT and B-US have a higher diagnostic value, which can show the internal shape and character better. B-US or CT guided puncturing biopsy can be better applied to atypical renal cysts. Once the correct diagnosis is acquired, laparoscopic surgical treatment should be carried out.

  19. Genetic analysis of long-lived families reveals novel variants influencing high density-lipoprotein cholesterol

    DEFF Research Database (Denmark)

    Feitosa, Mary F; Wojczynski, Mary K; Straka, Robert

    2014-01-01

    The plasma levels of high-density lipoprotein cholesterol (HDL) have an inverse relationship to the risks of atherosclerosis and cardiovascular disease (CVD), and have also been associated with longevity. We sought to identify novel loci for HDL that could potentially provide new insights...

  20. Automated Method for Analysis of Mammographic Breast Density - A Technique for Breast Cancer Risk Estimation

    Science.gov (United States)

    2006-07-01

    mammographic density: Implications for under- standing breast cancer,’’ J. Natl. Cancer Inst. 89, 531–532 ~1997!. 10 W. Leung, F. Goldberg, B. Zee ... Mexico . Radiology 1998;209:511–518. 4. Boyd NF, Byng RA, Jong EK, et al. Quantita- tive classification of mammographic densi- ties and breast cancer risk

  1. Evaluation of char combustion models: measurement and analysis of variability in char particle size and density

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Maloney; Esmail R. Monazam; Kent H. Casleton; Christopher R. Shaddix

    2008-08-01

    Char samples representing a range of combustion conditions and extents of burnout were obtained from a well-characterized laminar flow combustion experiment. Individual particles from the parent coal and char samples were characterized to determine distributions in particle volume, mass, and density at different extent of burnout. The data were then compared with predictions from a comprehensive char combustion model referred to as the char burnout kinetics model (CBK). The data clearly reflect the particle- to-particle heterogeneity of the parent coal and show a significant broadening in the size and density distributions of the chars resulting from both devolatilization and combustion. Data for chars prepared in a lower oxygen content environment (6% oxygen by vol.) are consistent with zone II type combustion behavior where most of the combustion is occurring near the particle surface. At higher oxygen contents (12% by vol.), the data show indications of more burning occurring in the particle interior. The CBK model does a good job of predicting the general nature of the development of size and density distributions during burning but the input distribution of particle size and density is critical to obtaining good predictions. A significant reduction in particle size was observed to occur as a result of devolatilization. For comprehensive combustion models to provide accurate predictions, this size reduction phenomenon needs to be included in devolatilization models so that representative char distributions are carried through the calculations.

  2. NBO analysis and vibrational frequencies of tautomers of citrinin by density functional theory

    Science.gov (United States)

    Citrinin is a toxic polyketide contaminant of a number of agricultural commodities, notably Monascus-fermented red rice. Detailed structures and electronic properties of three tautomeric forms of citrinin were investigated using density functional theory calculations at various extended basis sets ...

  3. Densities of Pure Ionic Liquids and Mixtures: Modeling and Data Analysis

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2015-01-01

    Our two-parameter corresponding states model for liquid densities and compressibilities has been extended to more pure ionic liquids and to their mixtures with one or two solvents. A total of 19 new group contributions (5 new cations and 14 new anions) have been obtained for predicting pressure...

  4. Stereoscopy of dust density waves under microgravity: Velocity distributions and phase-resolved single-particle analysis

    Energy Technology Data Exchange (ETDEWEB)

    Himpel, Michael, E-mail: himpel@physik.uni-greifswald.de; Killer, Carsten; Melzer, André [Institute of Physics, Ernst-Moritz-Arndt-University, 17489 Greifswald (Germany); Bockwoldt, Tim; Piel, Alexander [IEAP, Christian-Albrechts-Universität Kiel, D-24098 Kiel (Germany); Ole Menzel, Kristoffer [ABB Switzerland Ltd, Corporate Research Center, 5405 Dättwil (Switzerland)

    2014-03-15

    Experiments on dust-density waves have been performed in dusty plasmas under the microgravity conditions of parabolic flights. Three-dimensional measurements of a dust density wave on a single particle level are presented. The dust particles have been tracked for many oscillation periods. A Hilbert analysis is applied to obtain trajectory parameters such as oscillation amplitude and three-dimensional velocity amplitude. While the transverse motion is found to be thermal, the velocity distribution in wave propagation direction can be explained by harmonic oscillations with added Gaussian (thermal) noise. Additionally, it is shown that the wave properties can be reconstructed by means of a pseudo-stroboscopic approach. Finally, the energy dissipation mechanism from the kinetic oscillation energy to thermal motion is discussed and presented using phase-resolved analysis.

  5. Prognostic relevance of DHAP dose-density in relapsed Hodgkin lymphoma: an analysis of the German Hodgkin-Study Group.

    Science.gov (United States)

    Sasse, Stephanie; Alram, Magdalena; Müller, Horst; Smardová, Lenka; Metzner, Bernd; Doehner, Hartmut; Fischer, Thomas; Niederwieser, Dietger W; Schmitz, Norbert; Schäfer-Eckart, Kerstin; Raemaekers, John M M; Schmalz, Oliver; Tresckow, Bastian V; Engert, Andreas; Borchmann, Peter

    2016-05-01

    Only 50% of patients with relapsed Hodgkin lymphoma (HL) can be cured with intensive induction chemotherapy, followed by high-dose chemotherapy (HDCT) and autologous stem cell transplant (ASCT). Based on the results of the HDR2 trial two courses of DHAP and subsequent HDCT/ASCT are the current standard of care in relapsed HL. In order to assess the prognostic relevance of DHAP dose density, we performed a retrospective multivariate analysis of the HDR2 trial (N=266). In addition to four risk factors (early or multiple relapse, stage IV disease or anemia at relapse, and grade IV hematotoxicity during the first cycle of DHAP) a delayed start of the second cycle of DHAP>day 22 predicted a significantly poorer progression-free survival (PFS, p=0.0356) and overall survival (OS, p=0.0025). In conclusion, our analysis strongly suggests that dose density of DHAP has a relevant impact on the outcome of relapsed HL patients.

  6. Values of Particle Size Particle Density & Slurry Viscosity to use in Waste Feed Delivery Transfer System Analysis

    Energy Technology Data Exchange (ETDEWEB)

    JEWETT, J R

    2002-01-30

    Recommended values have been developed for particle size distribution, particle density, and slurry viscosity that maybe used in slurry flow calculations that support the design of the piping system that is being modified to deliver Hanford wastes from the underground storage tanks to the planned Waste Treatment Plant for vitrification. The objective of this document is to provide recommended values for three waste properties to be used in a planned revision of the Waste Feed Delivery Transfer System Analysis. These properties are particle size distribution (PSD), particle density, and slurry viscosity. In this document, the results of laboratory and engineering studies will be collated and summarized to provide a succinct source of physical property data for use in the hydraulic analysis of the transfer system.

  7. Thermal properties measurement of dry bulk materials with a cylindrical three layers device

    Science.gov (United States)

    Jannot, Y.; Degiovanni, A.

    2013-09-01

    This paper presents a new method dedicated to thermal properties (conductivity and diffusivity) measurement of dry bulk materials including powders. The cylindrical three layers experimental device (brass/bulk material/stainless steel) and the principle of the measurement method based on a crenel thermal excitation are presented. The one-dimensional modeling of the system is used for a sensitivity analysis and to calculate the standard deviation of the estimation error. Experimental measurements are carried out on three bulk materials: glass beads, cork granules, and expanded polystyrene beads. The estimated thermal properties are compared with the values obtained by other measurement methods. Results are in good agreement with theoretical predictions: both thermal conductivity and diffusivity can be estimated with a good accuracy for low density material like cork granules or expanded polystyrene beads since only thermal diffusivity can be estimated for heavier materials like glass beads. It is finally shown that this method like all transient methods is not suited to the thermal characterization of wet bulk materials.

  8. Can bulk viscosity drive inflation

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, T.; Stein-Schabes, J.A.; Turner, M.S.

    1987-04-01

    Contrary to other claims, we argue that, bulk viscosity associated with the interactions of nonrelativistic particles with relativistic particles around the time of the grand unified theory (GUT) phase transition cannot lead to inflation. Simply put, the key ingredient for inflation, negative pressure, cannot arise due to the bulk viscosity effects of a weakly-interacting mixture of relativistic and nonrelativistic particles. 13 refs., 1 fig.

  9. Modeling of Microimprinting of Bulk Metallic Glasses

    Institute of Scientific and Technical Information of China (English)

    Ming CHENG; John A. Wert

    2006-01-01

    A finite element analysis (FEA) model has been developed to analyze microimprinting of bulk metallic glasses (BMG) near the glass transition temperature (Tg). The results reveal an approximately universal imprinting response for BMG, independent of surface feature length scale. The scale-independent nature of BMG imprinting derives from the flow characteristics of BMG in the temperature range above Tg. It also shows that the lubrication condition has a mild influence on BMG imprinting in the temperature range above Tg.

  10. Analysis of Vibration Mode for H2+F→HF+H Reaction Mechanism: Density functional Theory Calculation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Three density functional theory methods (DFT) have been used to investigate the H2+F?HF+H reaction comparing with the Hartree-Fock method and Moller-Plesset (MP2) perturbation theory method. Through the analysis of the vibrational mode and vibrational frequency in the reaction process, the reaction mechanism has been discussed. The activation energy, the reorganization energy and rate constant of the ET reaction are calculated at semi-quantitative level.

  11. An analysis on the transmission of electron density through sulphur atoms in the quaternization reactions of benzothiazoles

    Indian Academy of Sciences (India)

    B K Mishra; Sabita Patel

    2002-02-01

    The kinetics of quaternization of a number of 2-substituted benzothiazoles with alkyl iodides and phenacyl bromide have been studied in nitrobenzene. The order of reactivity of different substituted benzothiazoles has been found to be -H > NO2 > Cl. The relative reactivity of 2-amino and 2-methyl derivatives has been ascribed to a solvation phenomenon. The analysis of rho values from the Hammett equation suggests two possible routes for the transmission of electron density.

  12. Cross Kelvin force microscopy and conductive atomic force microscopy studies of organic bulk heterojunction blends for local morphology and electrical behavior analysis

    Energy Technology Data Exchange (ETDEWEB)

    Villeneuve-Faure, C., E-mail: Christina.villeneuve@laplace.unvi-tlse.fr [LAPLACE, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse (France); UPS, INPT, Université de Toulouse, LCC 31077 Toulouse (France); Le Borgne, D. [LAPLACE, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse (France); UPS, INPT, Université de Toulouse, LCC 31077 Toulouse (France); LCC-CNRS, 205 route de Narbonne, F-31077 Toulouse Cedex 4 (France); Bedel-Pereira, E.; Séguy, I. [UPS, INPT, Université de Toulouse, LCC 31077 Toulouse (France); LAAS-CNRS, 7 Avenue du Colonel Roche, 31077 Toulouse Cedex 4 (France); Moineau Chane-Ching, K. I.; Hernandez-Maldonado, D. [UPS, INPT, Université de Toulouse, LCC 31077 Toulouse (France); LCC-CNRS, 205 route de Narbonne, F-31077 Toulouse Cedex 4 (France)

    2015-02-07

    Bulk Heterojunction (BHJ) organic photovoltaic devices performances depend on the relative organization and physical properties of the electron-donor and -acceptor materials. In this paper, BHJs of poly(3-hexyl-thiophene) (P3HT) associated with an electron acceptor material, 1-(3-methoxycarbonyl)-propyl-1-phenyl[6,6]C6 (PCBM) or [Ni(4dodpedt){sub 2}], are studied in terms of morphology, ordering, and electrical properties. First, comparison between the two BHJs performed by Atomic Force Microscopy (AFM) and Raman characterizations shows that P3HT structuration is improved by blending with [Ni(4dodpedt){sub 2}]. Then, the relationship between charges trapping, electrical properties, and film morphology is investigated using conductive AFM and Kelvin Force Microscopy. Measurements in dark condition and under solar cell simulator provide complementary information on electrical phenomena in these organic nanostructures. Finally, time dependent measurement highlights the influence of charges stacking on conduction. Specifically, we demonstrate that charge accumulation initiated by illumination remains valid after switching off the light, and induces the modification in current versus voltage characteristic of P3HT: PCBM blend. Finally, we observe a current increasing which can be attributed to the energy barrier decreasing due to charges trapping in PCBM.

  13. 38000 DWT 杂货船轴系方案比较分析%Comparative Analysis of Propulsion Shafting Arrangement for the 38 000 DWT Bulk Carrier

    Institute of Scientific and Technical Information of China (English)

    戴益民

    2014-01-01

    The 38 000 DWT bulk carrier propulsion shafting was taken as the research objection .For the two kinds of ar-rangement of the propulsion shafting system , one has fore and after stern tube bearing and the other only has after stern tube bear -ing, the bearing load and vertical displacement of bearing were compared , especially the bearing load distribution when main en-gine running at SMCR .The results showed that cancelling the fore stern tube bearing , and shift the intermediate bearing aft , it can improve the system running condition .%以38000 DWT杂货船推进轴系为研究对象,比较分析艉管有前、后轴承和艉管仅有后轴承两种轴系布置方案下各轴承负荷、垂直位移等变化,特别是SMCR工况下轴承负荷的分布情况。结果表明:仅有后轴承,并将中间轴承后移,能够更好地改善轴系运行状态。

  14. Queuing Theory Based Co-Channel Interference Analysis Approach for High-Density Wireless Local Area Networks

    Science.gov (United States)

    Zhang, Jie; Han, Guangjie; Qian, Yujie

    2016-01-01

    Increased co-channel interference (CCI) in wireless local area networks (WLANs) is bringing serious resource constraints to today’s high-density wireless environments. CCI in IEEE 802.11-based networks is inevitable due to the nature of the carrier sensing mechanism however can be reduced by resource optimization approaches. That means the CCI analysis is basic, but also crucial for an efficient resource management. In this article, we present a novel CCI analysis approach based on the queuing theory, which considers the randomness of end users’ behavior and the irregularity and complexity of network traffic in high-density WLANs that adopts the M/M/c queuing model for CCI analysis. Most of the CCIs occur when multiple networks overlap and trigger channel contentions; therefore, we use the ratio of signal-overlapped areas to signal coverage as a probabilistic factor to the queuing model to analyze the CCI impacts in highly overlapped WLANs. With the queuing model, we perform simulations to see how the CCI influences the quality of service (QoS) in high-density WLANs. PMID:27563896

  15. Queuing Theory Based Co-Channel Interference Analysis Approach for High-Density Wireless Local Area Networks.

    Science.gov (United States)

    Zhang, Jie; Han, Guangjie; Qian, Yujie

    2016-08-23

    Increased co-channel interference (CCI) in wireless local area networks (WLANs) is bringing serious resource constraints to today's high-density wireless environments. CCI in IEEE 802.11-based networks is inevitable due to the nature of the carrier sensing mechanism however can be reduced by resource optimization approaches. That means the CCI analysis is basic, but also crucial for an efficient resource management. In this article, we present a novel CCI analysis approach based on the queuing theory, which considers the randomness of end users' behavior and the irregularity and complexity of network traffic in high-density WLANs that adopts the M/M/c queuing model for CCI analysis. Most of the CCIs occur when multiple networks overlap and trigger channel contentions; therefore, we use the ratio of signal-overlapped areas to signal coverage as a probabilistic factor to the queuing model to analyze the CCI impacts in highly overlapped WLANs. With the queuing model, we perform simulations to see how the CCI influences the quality of service (QoS) in high-density WLANs.

  16. Densidade e qualidade dos estratos de forragem do capim Tanzânia (Panicum maximum Jacq. Cv. Tanzânia-1 manejado em diferentes alturas, sob pastejo Density bulk and quality of Tanzania grass layers (Panicum maximum Jacq.cv. Tanzania-1, at different heights in grazing

    Directory of Open Access Journals (Sweden)

    Geraldo Tadeu dos Santos

    2001-05-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito de diferentes alturas (24; 26; 43; 45; 52; 62; 73 e 78 cm do pasto sobre a qualidade de forragem e estrutura do perfil do capim-Tanzânia, (Panicum maximum Jacq. cv. Tanzânia – 1 (Poaceae. Foram utilizados novilhos da raça Nelore sob pastejo com carga animal variável, por meio da técnica put and take. O delineamento experimental utilizado foi inteiramente casualizado, com duas repetições. A densidade de matéria seca total (DMT aumentou com o avanço no período experimental, enquanto a densidade de matéria seca de lâminas (DML não foi influenciada pelo período e pela altura do pasto. O estrato superior da pastagem foi a porção de maior qualidade, apresentando maior DML e maior teor de PB. Os estratos inferiores apresentaram menor qualidade, devido à maior DMT e menor DML, acarretando em maiores valores de FDA e FDN e menores teores de PB. O conteúdo de minerais das lâminas foi superior aos colmos, mantendo-se inalterado com relação aos estratos da pastagem.The effect of different sward heights (24; 26; 43; 45; 52; 62; 73 and 78 cm on forage quality and profile structure Tanzania grass, Panicum maximum Jacq. cv. Tanzania – 1 (Poaceae is provided. Nelore steers were used in grazing at variable stocking rates with put and take technique. The experimental design was completely randomized, with two replications. Total dry matter bulk densitity (TDMD increased during experimental period, while the leaf blade dry matter bulk density (LDMD was not influenced by period on by sward height. The upper layers had the best quality with higher LDMD and CP levels. Lower layers had the worst quality, due the higher TDMD and lower LDMD. This fact caused higher ADF and NDF levels and lower CP levels. Leaf blade mineral content was higher than that of stem, and remained unaltered in relation to the different layers.

  17. Probability density function formalism for optical coherence tomography signal analysis: a controlled phantom study.

    Science.gov (United States)

    Weatherbee, Andrew; Sugita, Mitsuro; Bizheva, Kostadinka; Popov, Ivan; Vitkin, Alex

    2016-06-15

    The distribution of backscattered intensities as described by the probability density function (PDF) of tissue-scattered light contains information that may be useful for tissue assessment and diagnosis, including characterization of its pathology. In this Letter, we examine the PDF description of the light scattering statistics in a well characterized tissue-like particulate medium using optical coherence tomography (OCT). It is shown that for low scatterer density, the governing statistics depart considerably from a Gaussian description and follow the K distribution for both OCT amplitude and intensity. The PDF formalism is shown to be independent of the scatterer flow conditions; this is expected from theory, and suggests robustness and motion independence of the OCT amplitude (and OCT intensity) PDF metrics in the context of potential biomedical applications.

  18. Analysis of Tensegrity Structures with Redundancies, by Implementing a Comprehensive Equilibrium Equations Method with Force Densities

    Directory of Open Access Journals (Sweden)

    Miltiades Elliotis

    2016-01-01

    Full Text Available A general approach is presented to analyze tensegrity structures by examining their equilibrium. It belongs to the class of equilibrium equations methods with force densities. The redundancies are treated by employing Castigliano’s second theorem, which gives the additional required equations. The partial derivatives, which appear in the additional equations, are numerically replaced by statically acceptable internal forces which are applied on the structure. For both statically determinate and indeterminate tensegrity structures, the properties of the resulting linear system of equations give an indication about structural stability. This method requires a relatively small number of computations, it is direct (there is no iteration procedure and calculation of auxiliary parameters and is characterized by its simplicity. It is tested on both 2D and 3D tensegrity structures. Results obtained with the method compare favorably with those obtained by the Dynamic Relaxation Method or the Adaptive Force Density Method.

  19. Analysis of electronic models for solar cells including energy resolved defect densities

    Energy Technology Data Exchange (ETDEWEB)

    Glitzky, Annegret

    2010-07-01

    We introduce an electronic model for solar cells including energy resolved defect densities. The resulting drift-diffusion model corresponds to a generalized van Roosbroeck system with additional source terms coupled with ODEs containing space and energy as parameters for all defect densities. The system has to be considered in heterostructures and with mixed boundary conditions from device simulation. We give a weak formulation of the problem. If the boundary data and the sources are compatible with thermodynamic equilibrium the free energy along solutions decays monotonously. In other cases it may be increasing, but we estimate its growth. We establish boundedness and uniqueness results and prove the existence of a weak solution. This is done by considering a regularized problem, showing its solvability and the boundedness of its solutions independent of the regularization level. (orig.)

  20. A sublinear-scaling approach to density-functional-theory analysis of crystal defects

    Science.gov (United States)

    Ponga, M.; Bhattacharya, K.; Ortiz, M.

    2016-10-01

    We develop a sublinear-scaling method, referred to as MacroDFT, for the study of crystal defects using ab-initio Density Functional Theory (DFT). The sublinear scaling is achieved using a combination of the Linear Scaling Spectral Gauss Quadrature method (LSSGQ) and a Coarse-Graining approach (CG) based on the quasi-continuum method. LSSGQ reformulates DFT and evaluates the electron density without computing individual orbitals. This direct evaluation is possible by recourse to Gaussian quadrature over the spectrum of the linearized Hamiltonian operator. Furthermore, the nodes and weights of the quadrature can be computed independently for each point in the domain. This property is exploited in CG, where fields of interest are computed at selected nodes and interpolated elsewhere. In this paper, we present the MacroDFT method, its parallel implementation and an assessment of convergence and performance by means of test cases concerned with point defects in magnesium.

  1. Analysis on insulator–metal transition in yttrium doped LSMO from electron density distribution

    Indian Academy of Sciences (India)

    S Israel; S Saravana Kumar; R Renuretson; R A J R Sheeba; R Saravanan

    2012-02-01

    Yttrium doped LSMO (La1−SrMnO3) was prepared using sol–gel technique and analysed for the insulator–metal transition fromcharge density variation in the unit cell with respect to different stoichiometric inclusion of yttrium. X-ray powder diffraction profiles of the samples were obtained and the well known Rietveld method and a versatile tool called maximum entropy method (MEM) were used for structural and profile refinement. The charge density in the unit cell was constructed using refined structure factors and was analysed. The charge ordering taking place in the insulator–metal transition was investigated and quantified. The insulator–metal transition was found to occur when 20% of La/Sr atoms were replaced by yttrium. The changes in the charge environment have also been analysed.

  2. Thermal Experimental Analysis for Dielectric Characterization of High Density Polyethylene Nanocomposites

    Directory of Open Access Journals (Sweden)

    Ahmed Thabet Mohamed

    2016-01-01

    Full Text Available The importance of nanoparticles in controlling physical properties of polymeric nanocomposite materials leads us to study effects of these nanoparticles on electric and dielectric properties of polymers in industry In this research, the dielectric behaviour of High-Density Polyethylene (HDPE nanocomposites materials that filled with nanoparticles of clay or fumed silica has been investigated at various frequencies (10 Hz-1 kHz and temperatures (20-60°C. Dielectric spectroscopy has been used to characterize ionic conduction, then, the effects of nanoparticles concentration on the dielectric losses and capacitive charge of the new nanocomposites can be stated. Capacitive charge and loss tangent in high density polyethylene nanocomposites are measured by dielectric spectroscopy. Different dielectric behaviour has been observed depending on type and concentration of nanoparticles under variant thermal conditions.

  3. Analysis of Time-Dependent Density Functional Theory of Transition Wavelengths of Thioaldehydes and Thioketones

    Institute of Scientific and Technical Information of China (English)

    HE Xiang; WANG Fan

    2006-01-01

    @@ Thioaldehydes and thioketones are candidates of new photoluminescence materials. The time-dependent density functional theory is applied to calculate the absorption and emission wavelengths of ten thiocarbonyl compounds using both B3LYP and PBE0 functionals. The theoretical results are in agreement with the measurable ones.Furthermore, it is found that the maximum absorption and emission wavelengths are linearly correlated to the C-S bond lengths.

  4. CH spectroscopy for carbon chemical erosion analysis in high density low temperature hydrogen plasma

    NARCIS (Netherlands)

    Westerhout, J.; Cardozo, N. J. L.; Rapp, J.; van Rooij, G. J.

    2009-01-01

    The CH A-X molecular band is measured upon seeding the hydrogen plasma in the linear plasma generator Pilot-PSI [electron temperature T-e=0.1-2.5 eV and electron density n(e)=(0.5-5) X 10(20) m(-3)] with methane. Calculated inverse photon efficiencies for these conditions range from 3 up to >10(6

  5. Error Analysis of a Fractional Time-Stepping Technique for Incompressible Flows with Variable Density

    KAUST Repository

    Guermond, J.-L.

    2011-01-01

    In this paper we analyze the convergence properties of a new fractional time-stepping technique for the solution of the variable density incompressible Navier-Stokes equations. The main feature of this method is that, contrary to other existing algorithms, the pressure is determined by just solving one Poisson equation per time step. First-order error estimates are proved, and stability of a formally second-order variant of the method is established. © 2011 Society for Industrial and Applied Mathematics.

  6. Dislocation density analysis in single grains of steel by X-ray scanning microdiffraction

    CERN Document Server

    Castelnau, O; Schrör, C; Snigireva, I; Snigirev, A; Ungar, T

    2001-01-01

    A new set-up for X-ray micro-diffraction has been developed on the ESRF beamline ID22. It allows microscopic characterization of materials with micrometer resolution. This facilitates the measurement of material quantities as average size of the coherently diffracting volume, local dislocation density, residual stress, local fluctuation of the residual stress, and intragranular misorientation from single grains of a polycrystalline material. The first application on an IF-Ti steel after different thermo-mechanical treatments is presented.

  7. Bulk Viscosity Effects in Event-by-Event Relativistic Hydrodynamics

    CERN Document Server

    Noronha-Hostler, Jacquelyn; Noronha, Jorge; Andrade, Rone P G; Grassi, Frederique

    2013-01-01

    Bulk viscosity effects on the collective flow harmonics in heavy ion collisions are investigated, on an event by event basis, using a newly developed 2+1 Lagrangian hydrodynamic code named v-USPhydro which implements the Smoothed Particle Hydrodynamics (SPH) algorithm for viscous hydrodynamics. A new formula for the bulk viscous corrections present in the distribution function at freeze-out is derived starting from the Boltzmann equation for multi-hadron species. Bulk viscosity is shown to enhance the collective flow Fourier coefficients from $v_2(p_T)$ to $v_5(p_T)$ when $% p_{T}\\sim 1-3$ GeV even when the bulk viscosity to entropy density ratio, $% \\zeta/s$, is significantly smaller than $1/(4\\pi)$.

  8. A comparative analysis of the density distributions and the structure models of 9Li

    Science.gov (United States)

    Aygun, M.

    2017-03-01

    In the present study, we have analysed the elastic scattering cross-section data of 9Li + 12C system at E lab = 540 MeV and 9Li + 208Pb system at E c.m. = 28.3 MeV for some cluster models and various density distributions of the 9Li nucleus. First, we have obtained five different density distributions of the 9Li nucleus to generate real potentials with the help of double-folding model. For these densities, we have calculated the elastic scattering angular distributions. Secondly, using a simple approach, we have investigated some cluster models of the 9Li nucleus consisting of 6He + 3H and 8Li + n systems. We have presented the comparison of elastic scattering angular distributions for each system with each other as well as with the experimental data. Finally, we have given the cross-section values obtained from the theoretical calculations for all the systems studied in this paper.

  9. Stochastic analysis of transverse dispersion in density-coupled transport in aquifers

    Science.gov (United States)

    Welty, C.; Kane, A. C.; Kauffman, L.J.

    2003-01-01

    Spectral perturbation techniques have been used previously to derive integral expressions for dispersive mixing in concentration-dependent transport in three-dimensional, heterogeneous porous media, where fluid density and viscosity are functions of solute concentration. Whereas earlier work focused on evaluating longitudinal dispersivity in isotropic media and incorporating the result in a mean one-dimensional transport model, the emphasis of this paper is on evaluation of the complete dispersion tensor, including the more general case of anisotropic media. Approximate analytic expressions for all components of the macroscopic dispersivity tensor are derived, and the tensor is shown to be asymmetric. The tensor is separated into its symmetric and antisymmetric parts, where the symmetric part is used to calculate the principal components and principal directions of dispersivity, and the antisymmetric part of the tensor is shown to modify the velocity of the solute body compared to that of the background fluid. An example set of numerical simulations incorporating the tensor illustrates the effect of density-coupled dispersivity on a sinking plume in an aquifer. The simulations show that the effective transverse vertical spreading in a sinking plume to be significantly greater than would be predicted by a standard density-coupled transport model that does not incorporate the coupling in the dispersivity tensor.

  10. A comparative analysis of the density distributions and the structure models of $^{9}$Li

    Indian Academy of Sciences (India)

    M AYGUN

    2017-03-01

    In the present study, we have analysed the elastic scattering cross-section data of $^{9}$Li + $^{12}$C system at $E_{lab}$ = 540 MeV and $^{9}$Li + $^{208}$Pb system at $E_{c.m.}$ = 28.3 MeV for some cluster models and various density distributions of the $^{9}$Li nucleus. First, we have obtained five different density distributions of the $^{9}$Li nucleus to generate real potentials with the help of double-folding model. For these densities, we have calculated the elastic scattering angular distributions. Secondly, using a simple approach, we have investigated some cluster models of the $^{9}$Li nucleus consisting of $^{6}$He + $^{3}$H and $^{8}$Li + n systems. We have presented the comparison of elastic scattering angular distributions for each system with each other as well as with the experimental data. Finally, we have given the cross-section values obtained from the theoretical calculations for all the systems studied in this paper.

  11. Molecular column densities in selected model atmospheres. [chemical analysis of carbon stars

    Science.gov (United States)

    Johnson, H. R.; Beebe, R. F.; Sneden, C.

    1974-01-01

    From an examination of predicted column densities, the following conclusions were drawn: (1) The SiO ought to be visible in carbon stars which were generated from triple alpha burning, but absent from carbon stars generated from the CNO bi-cycle. (2) Variation in the observed relative strengths of TiO and ZrO is indicative of real differences in the ratio Ti/Zr. (3) The TiO/ZrO ratio shows a small variation as C/O and effective temperature is changed. (4) Column density of silicon dicarbide (SiC2) is sensitive to abundance, temperature, and gravity; hence all relationships between the strength of SiC2 and other stellar parameters will show appreciable scatter. There is however, a substantial luminosity effect present in the SiC2 column densities. (5) Unexpectedly, SiC2 is anti-correlated with C2. (6) The presence of SiC2 in a carbon star eliminates the possibility of these stars having temperatures greater than or equal to 3000 K, or being produced through the CNO bi-cycle.

  12. Nondestructive Method for Bulk Chemical Characterization of Barred Olivine Chondrules

    Science.gov (United States)

    Montoya-Perez, M. A.; Cervantes-de la Cruz, K. E.; Ruvalcaba-Sil, J. L.

    2017-02-01

    This work develops a bulk chemical characterization of barred olivine chondrules based on the XRF analysis using a portable equipment at the National Research and Conservation Science Laboratory of Cultural Heritage (LANCIC-IF) in Mexico City.

  13. Spherical harmonic decomposition applied to spatial-temporal analysis of human high-density EEG

    OpenAIRE

    Wingeier, Brett M.; Nunez, Paul L.; Silberstein, Richard B.

    2000-01-01

    We demonstrate an application of spherical harmonic decomposition to analysis of the human electroencephalogram (EEG). We implement two methods and discuss issues specific to analysis of hemispherical, irregularly sampled data. Performance of the methods and spatial sampling requirements are quantified using simulated data. The analysis is applied to experimental EEG data, confirming earlier reports of an approximate frequency-wavenumber relationship in some bands.

  14. Spherical harmonic decomposition applied to spatial-temporal analysis of human high-density EEG

    CERN Document Server

    Wingeier, B M; Silberstein, R B; Wingeier, Brett M.; Nunez, Paul L.; Silberstein, Richard B.

    2001-01-01

    We demonstrate an application of spherical harmonic decomposition to analysis of the human electroencephalogram (EEG). We implement two methods and discuss issues specific to analysis of hemispherical, irregularly sampled data. Performance of the methods and spatial sampling requirements are quantified using simulated data. The analysis is applied to experimental EEG data, confirming earlier reports of an approximate frequency-wavenumber relationship in some bands.

  15. Immunocytochemical analysis of cubilin-mediated endocytosis of high density lipoproteins (HDL) in epithelial cells of the rat visceral yolk sac.

    Science.gov (United States)

    Ishida, Tetsuya; Hatae, Tanenori; Nishi, Nozomu; Araki, Nobukazu; Hamasaki, Masao

    2004-12-01

    Cubilin was recently shown to function as an endocytic receptor for high density lipoprotein (HDL) holoparticles and apolipoprotein A-I (apo A-I), the main protein constituent of HDL. In the present study, we analyzed the distribution and intracellular trafficking of cubilin and HDL in rat visceral yolk sac epithelial cells. After epithelial cells were loaded with apolipoprotein E-free HDL for 30 min in vitro, double immunofluorescence showed that the apical cytoplasm of the cells was strongly stained with anti-cubilin antibodies and anti-apo A-I/HDL. Furthermore, double immunogold electron-microscopic observations revealed the distinct localization of cubilin and HDL in endocytic vacuoles. In early endosomes, both were colocalized on the membrane. Although, in late endosomes, cubilin was also localized on the membrane, HDL was mainly located in the matrix. Both were found in the matrix in lysosomes. In addition, cubilin was markedly localized in apical tubules (ATs), which are generally accepted as being receptor recycling compartments. Thus, HDL is internalized through cubilin-mediated endocytosis and is finally transported to lysosomes. By contrast, cubilin is mainly translocated to ATs for recycling, although some of the cubilin is degraded in lysosomes. Quantitative analysis further revealed that cubilin was not concentrated on the membranes of ATs, although it accumulated in the AT area. Some HDL were also observed in the AT area. These findings suggest that the translocation of cubilin and HDL to ATs from early endosomes occurs through a simple sorting mechanism based on the geometry of these compartments and the bulk membrane and volume flow.

  16. Structural analysis of the SDSS Cosmic Web - I. Non-linear density field reconstructions

    Science.gov (United States)

    Platen, Erwin; van de Weygaert, Rien; Jones, Bernard J. T.; Vegter, Gert; Calvo, Miguel A. Aragón

    2011-10-01

    This study is the first in a series in which we analyse the structure and topology of the Cosmic Web as traced by the Sloan Digital Sky Survey (SDSS). The main issue addressed in the present study is the translation of the irregularly distributed discrete spatial data in the galaxy redshift survey into a representative density field. The density field will form the basis for a statistical, topological and cosmographic study of the cosmic density field in our Local Universe. We investigate the ability of three reconstruction techniques to analyse and investigate web-like features and geometries in a discrete distribution of objects. The three methods are the linear Delaunay Tessellation Field Estimator (DTFE), its higher order equivalent Natural Neighbour Field Estimator (NNFE) and a version of the Kriging interpolation adapted to the specific circumstances encountered in galaxy redshift surveys, the Natural Lognormal Kriging technique. DTFE and NNFE are based on the local geometry defined by the Voronoi and Delaunay tessellations of the galaxy distribution. The three reconstruction methods are analysed and compared using mock magnitude- and volume-limited SDSS redshift surveys, obtained on the basis of the Millennium simulation. We investigate error trends, biases and the topological structure of the resulting fields, concentrating on the void population identified by the Watershed Void Finder. Environmental effects are addressed by evaluating the density fields on a range of Gaussian filter scales. Comparison with the void population in the original simulation yields the fraction of false void mergers and false void splits. In most tests DTFE, NNFE and Kriging have largely similar density and topology error behaviour. Cosmetically, higher order NNFE and Kriging methods produce more visually appealing reconstructions. Quantitatively, however, DTFE performs better, even while being computationally far less demanding. A successful recovery of the void population on

  17. Energy density functional for nuclei and neutron stars

    CERN Document Server

    Erler, J; Nazarewicz, W; Rafalski, M; Reinhard, P -G

    2012-01-01

    We aim to develop a nuclear energy density functional that can be simultaneously applied to finite nuclei and neutron stars. We use the self-consistent nuclear density functional theory (DFT) with Skyrme energy density functionals and covariance analysis to assess correlations between observables for finite nuclei and neutron stars. In a first step two energy functionals -- a high density energy functional giving reasonable neutron properties, and a low density functional fitted to nuclear properties -- are matched. In a second step, we optimize a new functional using exactly the same protocol as in earlier studies pertaining to nuclei but now including neutron star data. This allows direct comparisons of performance of the new functional relative to the standard one. The new functional TOV-min yields results for nuclear bulk properties (energy, r.m.s. radius, diffraction radius, surface thickness) that are of the same quality as those obtained with the established Skyrme functionals, including SV-min. When c...

  18. Analysis of the annual trends of fire density in Southern Europe

    Science.gov (United States)

    Oliveira, Sandra; Oehler, Friderike; San-Miguel Ayanz, Jesus; Camia, Andrea; Durrant, Tracy

    2010-05-01

    Wildland fires are a major hazard in Europe, particularly in the Mediterranean area. The assessment of fire risk constitutes an important tool for forest fire management. Long-term or structural fire risk, even though it is a key component for the support of fire prevention activities, has not been investigated systematically at the European level. A research initiative is currently ongoing at the Joint Research Centre with the aim to develop a long-term fire risk model for Europe, to be integrated in the European Forest Fire Information System (EFFIS). For this purpose, fire risk is considered as a combination of fire occurrence and fire outcome. Fire occurrence is assessed based on the probability of ignition and estimated fire behaviour, while fire outcome is based on vulnerability. This study analysed the spatial and temporal trends of fire occurrence (ignition) in the Euro-Mediterranean region, from 1985 until 2007, in order to understand the subjacent factors of the fire distribution patterns, a topic even more relevant in a context of climatic and environmental change. Fire ignition data was obtained from the European Forest Fire Database of EFFIS, which currently includes data gathered from 21 countries and about 1.87 million individual fire records, of which 1.22 million are from the Euro-Mediterranean region. Due to the geo-location uncertainty associated with the database, fire density (number of fires/km2) was used as a surrogate of fire ignition. The total number of fire events per year was spatially distributed within the wildland area of the correspondent NUTS3 region (administrative districts used as geographical units to report fire events in the database). Corine Land Cover (CLC) 1990 was used to define the wildland areas for the period between 1985 and 1994 and CLC 2000 for the period between 1995 and 2007. Kernel density estimation methods (e.g. Amatulli et al., 2007) were applied to obtain the dependent variable in a continuous format

  19. STEM-EELS analysis reveals stable high-density He in nanopores of amorphous silicon coatings deposited by magnetron sputtering.

    Science.gov (United States)

    Schierholz, Roland; Lacroix, Bertrand; Godinho, Vanda; Caballero-Hernández, Jaime; Duchamp, Martial; Fernández, Asunción

    2015-02-20

    A broad interest has been showed recently on the study of nanostructuring of thin films and surfaces obtained by low-energy He plasma treatments and He incorporation via magnetron sputtering. In this paper spatially resolved electron energy-loss spectroscopy in a scanning transmission electron microscope is used to locate and characterize the He state in nanoporous amorphous silicon coatings deposited by magnetron sputtering. A dedicated MATLAB program was developed to quantify the helium density inside individual pores based on the energy position shift or peak intensity of the He K-edge. A good agreement was observed between the high density (∼35-60 at nm(-3)) and pressure (0.3-1.0 GPa) values obtained in nanoscale analysis and the values derived from macroscopic measurements (the composition obtained by proton backscattering spectroscopy coupled to the macroscopic porosity estimated from ellipsometry). This work provides new insights into these novel porous coatings, providing evidence of high-density He located inside the pores and validating the methodology applied here to characterize the formation of pores filled with the helium process gas during deposition. A similar stabilization of condensed He bubbles has been previously demonstrated by high-energy He ion implantation in metals and is newly demonstrated here using a widely employed methodology, magnetron sputtering, for achieving coatings with a high density of homogeneously distributed pores and He storage capacities as high as 21 at%.

  20. Broadening of the Spectral Atomic Lines Analysis in High Density Argon Corona Plasma by Using Voigt Profile

    Science.gov (United States)

    Nur, M.; Bonifaci, N.; Denat, A.; Atrazhev, V. M.

    2015-06-01

    Studies of spectrum emission from high density argon plasma corona has been done. The analysis of the boardening of spectral atomic lines of Ar-I profile has been curried out by using an empirical approximation based on a Voigt profile. Full-width at half-maximum (FWHM) of the spectral-lines of 763.5 nm has been determined from atmospheric pressure until liquid state. The study liquid argon was curried out in a variation of temperature from K to 151.2 K and hydrostatics pressure from 2.1 MPa to 6.4 MPa. These pressure gives the densities N∞ (i.e. density very far from ionization zone) a variation from 1.08 1022 to 2.11 1022 cm-3. FWHM of Voigt approximation (Wv) of the line 763,5 nm of 'Ar I for: the emission lamp very low pressure (Wv = 0,160 nm) and our corona discharge at a pressure of MPa (Wv = 0,67 nm) and at a pressure of 9,5 MPa (Wv = 1,16 nm). In gas, corona plasma has been generated from 0.1 MPa to 9.5 MPa. We found that the broadening spectral line increase by increasing densities both for. the spectral-lines of 763.5 nm and 696.5 nm. We concluded that broadening of spectrum cause of Van der Waals force.