WorldWideScience

Sample records for grain distribution system

  1. A method to calculate flux distribution in reactor systems containing materials with grain structure

    Stepanek, J.

    1980-01-01

    A method is proposed to compute the neutron flux spatial distribution in slab, spherical or cylindrical systems containing zones with close grain structure of material. Several different types of equally distributed particles embedded in the matrix material are allowed in one or more zones. The multi-energy group structure of the flux is considered. The collision probability method is used to compute the fluxes in the grains and in an ''effective'' part of the matrix material. Then the overall structure of the flux distribution in the zones with homogenized materials is determined using the DPN ''surface flux'' method. Both computations are connected using the balance equation during the outer iterations. The proposed method is written in the code SURCU-DH. Two testcases are computed and discussed. One testcase is the computation of the eigenvalue in simplified slab geometry of an LWR container of one zone with boral grains equally distributed in an aluminium matrix. The second is the computation of the eigenvalue in spherical geometry of the HTR pebble-bed cell with spherical particles embedded in a graphite matrix. The results are compared to those obtained by repeated use of the WIMS Code. (author)

  2. A luminescence imaging system for the routine measurement of single-grain OSL dose distributions

    Kook, Myung Ho; Lapp, Torben; Murray, Andrew

    2015-01-01

    the potential of an electron multiplying charge-coupled device (EMCCD), providing extremely low level light detection. We characterize the performance of the device by discussing reproducibility and evaluating uncertainties in OSL signals. Finally we derive a typical single grain natural dose distribution...

  3. Methods of assessing grain-size distribution during grain growth

    Tweed, Cherry J.; Hansen, Niels; Ralph, Brian

    1985-01-01

    This paper considers methods of obtaining grain-size distributions and ways of describing them. In order to collect statistically useful amounts of data, an automatic image analyzer is used, and the resulting data are subjected to a series of tests that evaluate the differences between two related...... distributions (before and after grain growth). The distributions are measured from two-dimensional sections, and both the data and the corresponding true three-dimensional grain-size distributions (obtained by stereological analysis) are collected. The techniques described here are illustrated by reference...

  4. Abnormal grain growth: a non-equilibrium thermodynamic model for multi-grain binary systems

    Svoboda, J; Fischer, F D

    2014-01-01

    Abnormal grain growth as the abrupt growth of a group of the largest grains in a multi-grain system is treated within the context of unequal retardation of grain growth due to the segregation of solute atoms from the bulk of the grains into the grain boundaries. During grain boundary migration, the segregated solute atoms are dragged under a small driving force or left behind the migrating grain boundary under a large driving force. Thus, the solute atoms in the grain boundaries of large grains, exhibiting a large driving force, can be released from the grain boundary. The mobility of these grain boundaries becomes significantly higher and abnormal grain growth is spontaneously provoked. The mean-field model presented here assumes that each grain is described by its grain radius and by its individual segregation parameter. The thermodynamic extremal principle is engaged to obtain explicit evolution equations for the radius and segregation parameter of each grain. Simulations of grain growth kinetics for various conditions of segregation with the same initial setting (100 000 grains with a given radius distribution) are presented. Depending on the diffusion coefficients of the solute in the grain boundaries, abnormal grain growth may be strongly or marginally pronounced. Solute segregation and drag can also significantly contribute to the stabilization of the grain structure. Qualitative agreement with several experimental results is reported. (paper)

  5. Autonomous grain combine control system

    Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

    2013-06-25

    A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

  6. TRAJECTORIES AND DISTRIBUTION OF INTERSTELLAR DUST GRAINS IN THE HELIOSPHERE

    Slavin, Jonathan D.; Frisch, Priscilla C.; Müller, Hans-Reinhard; Heerikhuisen, Jacob; Pogorelov, Nikolai V.; Reach, William T.; Zank, Gary

    2012-01-01

    The solar wind carves a bubble in the surrounding interstellar medium (ISM) known as the heliosphere. Charged interstellar dust grains (ISDG) encountering the heliosphere may be diverted around the heliopause or penetrate it depending on their charge-to-mass ratio. We present new calculations of trajectories of ISDG in the heliosphere, and the dust density distributions that result. We include up-to-date grain charging calculations using a realistic UV radiation field and full three-dimensional magnetohydrodynamic fluid + kinetic models for the heliosphere. Models with two different (constant) polarities for the solar wind magnetic field (SWMF) are used, with the grain trajectory calculations done separately for each polarity. Small grains a gr ∼ gr ∼> 1.0 μm, pass into the inner solar system and are concentrated near the Sun by its gravity. Trajectories of intermediate size grains depend strongly on the SWMF polarity. When the field has magnetic north pointing to ecliptic north, the field de-focuses the grains resulting in low densities in the inner heliosphere, while for the opposite polarity the dust is focused near the Sun. The ISDG density outside the heliosphere inferred from applying the model results to in situ dust measurements is inconsistent with local ISM depletion data for both SWMF polarities but is bracketed by them. This result points to the need to include the time variation in the SWMF polarity during grain propagation. Our results provide valuable insights for interpretation of the in situ dust observations from Ulysses.

  7. Microscopic determination of the PuO2 grain size and pore size distribution of MOX pellets with an image analysis system

    Vandezande, J.

    2000-01-01

    The industrial way to obtain the Pu distribution in a MOX pellet is by Image Analysis. The PuO 2 grains are made visible by alpha-autoradiography. Along with the Pu distribution the pore structure is an item which is examined, the latter is determined on the unetched sample. After the visualization of the sample structure, the sample is evaluated with an Image Analysis System. Each image is enhanced and a distinction is made between the objects to be measured and the matrix. The relevant parameters are then analyzed. When the overall particle distribution is wanted, all identified particles are measured and classified in size groups, based on a logarithmic scale. The possible conversion of two-dimensional diameters to three-dimensional diameters is accomplished by application of the Saltykov algorithm. When a single object is of interest, the object is selected interactively, and the result is reported to the user. (author)

  8. TRAJECTORIES AND DISTRIBUTION OF INTERSTELLAR DUST GRAINS IN THE HELIOSPHERE

    Slavin, Jonathan D. [Harvard-Smithsonian Center for Astrophysics, MS 83, 60 Garden Street, Cambridge, MA 02138 (United States); Frisch, Priscilla C. [Department of Astronomy and Astrophysics, University of Chicago, 5460 S. Ellis Avenue, Chicago, IL 60637 (United States); Mueller, Hans-Reinhard [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Heerikhuisen, Jacob; Pogorelov, Nikolai V. [Department of Physics and Center for Space Physics and Aeronomic Research, University of Alabama, Huntsville, AL 35899 (United States); Reach, William T. [Universities Space Research Association, MS 211-3, Moffett Field, CA 94035 (United States); Zank, Gary [Department of Physics and Center for Space Plasma and Aeronomic Research, University of Alabama, Huntsville, AL 35805 (United States)

    2012-11-20

    The solar wind carves a bubble in the surrounding interstellar medium (ISM) known as the heliosphere. Charged interstellar dust grains (ISDG) encountering the heliosphere may be diverted around the heliopause or penetrate it depending on their charge-to-mass ratio. We present new calculations of trajectories of ISDG in the heliosphere, and the dust density distributions that result. We include up-to-date grain charging calculations using a realistic UV radiation field and full three-dimensional magnetohydrodynamic fluid + kinetic models for the heliosphere. Models with two different (constant) polarities for the solar wind magnetic field (SWMF) are used, with the grain trajectory calculations done separately for each polarity. Small grains a {sub gr} {approx}< 0.01 {mu}m are completely excluded from the inner heliosphere. Large grains, a {sub gr} {approx}> 1.0 {mu}m, pass into the inner solar system and are concentrated near the Sun by its gravity. Trajectories of intermediate size grains depend strongly on the SWMF polarity. When the field has magnetic north pointing to ecliptic north, the field de-focuses the grains resulting in low densities in the inner heliosphere, while for the opposite polarity the dust is focused near the Sun. The ISDG density outside the heliosphere inferred from applying the model results to in situ dust measurements is inconsistent with local ISM depletion data for both SWMF polarities but is bracketed by them. This result points to the need to include the time variation in the SWMF polarity during grain propagation. Our results provide valuable insights for interpretation of the in situ dust observations from Ulysses.

  9. Effects of grain size distribution on the interstellar dust mass growth

    Hirashita, Hiroyuki; Kuo, Tzu-Ming

    2011-01-01

    Grain growth by the accretion of metals in interstellar clouds (called `grain growth') could be one of the dominant processes that determine the dust content in galaxies. The importance of grain size distribution for the grain growth is demonstrated in this paper. First, we derive an analytical formula that gives the grain size distribution after the grain growth in individual clouds for any initial grain size distribution. The time-scale of the grain growth is very sensitive to grain size di...

  10. Austenite Grain Size Estimtion from Chord Lengths of Logarithmic-Normal Distribution

    Adrian H.

    2017-12-01

    Full Text Available Linear section of grains in polyhedral material microstructure is a system of chords. The mean length of chords is the linear grain size of the microstructure. For the prior austenite grains of low alloy structural steels, the chord length is a random variable of gamma- or logarithmic-normal distribution. The statistical grain size estimation belongs to the quantitative metallographic problems. The so-called point estimation is a well known procedure. The interval estimation (grain size confidence interval for the gamma distribution was given elsewhere, but for the logarithmic-normal distribution is the subject of the present contribution. The statistical analysis is analogous to the one for the gamma distribution.

  11. Grain-size distributions and grain boundaries of chalcopyrite-type thin films

    Abou-Ras, D.; Schorr, S.; Schock, H.W.

    2007-01-01

    CuInSe 2 , CuGaSe 2 , Cu(In,Ga)Se 2 and CuInS 2 thin-film solar absorbers in completed solar cells were studied in cross section by means of electronbackscatter diffraction. From the data acquired, grain-size distributions were extracted, and also the most frequent grain boundaries were determined. The grain-size distributions of all chalcopyrite-type thin films studied can be described well by lognormal distribution functions. The most frequent grainboundary types in these thin films are 60 - left angle 221 right angle tet and 71 - left angle 110 right angle tet (near) Σ3 twin boundaries. These results can be related directly to the importance of {112} tet planes during the topotactical growth of chalcopyrite-type thin films. Based on energetic considerations, it is assumed that the most frequent twin boundaries exhibit a 180 - left angle 221 right angle tet constellation. (orig.)

  12. Distributed systems

    Van Steen, Maarten

    2017-01-01

    For this third edition of "Distributed Systems," the material has been thoroughly revised and extended, integrating principles and paradigms into nine chapters: 1. Introduction 2. Architectures 3. Processes 4. Communication 5. Naming 6. Coordination 7. Replication 8. Fault tolerance 9. Security A separation has been made between basic material and more specific subjects. The latter have been organized into boxed sections, which may be skipped on first reading. To assist in understanding the more algorithmic parts, example programs in Python have been included. The examples in the book leave out many details for readability, but the complete code is available through the book's Website, hosted at www.distributed-systems.net.

  13. Streaming of interstellar grains in the solar system

    Gustafson, B. A. S.; Misconi, N. Y.

    1979-01-01

    Results of a theoretical study of the interactions between interstellar grains streaming through the solar system and the solar wind are presented. It is shown that although elongated core-mantle interstellar particles of a characteristic radius of about 0.12 microns are subject to a greater force due to radiation pressure than to gravitational attraction, they are still able to penetrate deep inside the solar system. Calculations of particle trajectories within the solar system indicate substantial effects of the solar activity cycle as reflected in the interplanetary magnetic field on the distribution of 0.12- and 0.0005-micron interstellar grains streaming through the solar system, leading to a 50-fold increase in interstellar grain densities 3 to 4 AU ahead of the sun during years 8 to 17 of the solar cycle. It is noted that during the Solar Polar Mission, concentrations are expected which will offer the opportunity of detecting interstellar grains in the solar system.

  14. Interpretation of single grain De distributions and calculation of De

    Jacobs, Z.; Duller, G.A.T.; Wintle, A.G.

    2006-01-01

    Recent development of an instrument for measuring the optically stimulated luminescence signal from individual mineral grains has made it practicable to measure the equivalent dose (D e ) from many hundreds or thousands of single mineral grains from a sample. Such measurements can potentially be used to address issues such as sample integrity, and to make it possible to obtain ages from samples that consist of mixtures of grains, enlarging the range of materials to which luminescence dating can be applied. However, for reliable ages to be obtained, the characteristics of the equipment and the sample being analysed need to be understood. Using sensitised sedimentary quartz grains, the instrumental uncertainty in repeated optically stimulated luminescence measurements made using a single grain laser luminescence unit attached to a conventional luminescence reader was evaluated; a value of 1.2% was obtained. Grains from this sample were then used to investigate the uncertainty in a measured dose distribution obtained using the single aliquot measurement protocol on each grain that had previously received a known laboratory dose; after systematic rejection of grains that did not pass defined acceptance criteria, overdispersion of 7% was found. Additional spread in data was found when uniform aeolian sands were examined, resulting in overdispersion of ∼12%; this was attributed to a combination of factors relating to differences in field and laboratory conditions. A similar value was found for an archaeological horizon below this sand. For another sample from the same section, a significantly larger value was found, ∼29%; on this basis the finite mixture model was applied to obtain the likely dose components. The paper demonstrates the importance of correct assessment of error terms when analysing single grain D e distributions and a number of rejection criteria that are vital to avoid the inclusion of data that could lead to misinterpretation of the degree of

  15. Distribution of gluten proteins in bread wheat (Triticum aestivum) grain.

    Tosi, Paola; Gritsch, Cristina Sanchis; He, Jibin; Shewry, Peter R

    2011-07-01

    Gluten proteins are the major storage protein fraction in the mature wheat grain. They are restricted to the starchy endosperm, which forms white flour on milling, and interact during grain development to form large polymers which form a continuous proteinaceous network when flour is mixed with water to give dough. This network confers viscosity and elasticity to the dough, enabling the production of leavened products. The starchy endosperm is not a homogeneous tissue and quantitative and qualitative gradients exist for the major components: protein, starch and cell wall polysaccharides. Gradients in protein content and composition are the most evident and are of particular interest because of the major role played by the gluten proteins in determining grain processing quality. Protein gradients in the starchy endosperm were investigated using antibodies for specific gluten protein types for immunolocalization in developing grains and for western blot analysis of protein extracts from flour fractions obtained by sequential abrasion (pearling) to prepare tissue layers. Differential patterns of distribution were found for the high-molecular-weight subunits of glutenin (HMW-GS) and γ-gliadins when compared with the low-molecular-weight subunits of glutenin (LMW-GS), ω- and α-gliadins. The first two types of gluten protein are more abundant in the inner endosperm layers and the latter more abundant in the subaleurone. Immunolocalization also showed that segregation of gluten proteins occurs both between and within protein bodies during protein deposition and may still be retained in the mature grain. Quantitative and qualitative gradients in gluten protein composition are established during grain development. These gradients may be due to the origin of subaleurone cells, which unlike other starchy endosperm cells derive from the re-differentiation of aleurone cells, but could also result from the action of specific regulatory signals produced by the maternal tissue

  16. Grain-to-Grain Variations in NbC Particle Size Distributions in an Austenitic Stainless Steel

    Barlow, Claire; Ralph, B.; Silverman, B.

    1979-01-01

    Quantitative information has been obtained concerning the size distributions of NbC precipitate particles in different grains in a deformed and aged austenitic stainless steel specimen. The precipitate size distributions obtained differ from one grain to another. The average disparity measured be...

  17. Evolution of grain boundary character distributions in alloy 825 tubes during high temperature annealing: Is grain boundary engineering achieved through recrystallization or grain growth?

    Bai, Qin; Zhao, Qing; Xia, Shuang; Wang, Baoshun; Zhou, Bangxin; Su, Cheng

    2017-01-01

    Grain boundary engineering (GBE) of nickel-based alloy 825 tubes was carried out with different cold drawing deformations by using a draw-bench on a factory production line and subsequent annealing at various temperatures. The microstructure evolution of alloy 825 during thermal-mechanical processing (TMP) was characterized by means of the electron backscatter diffraction (EBSD) technique to study the TMP effects on the grain boundary network and the evolution of grain boundary character distributions during high temperature annealing. The results showed that the proportion of ∑ 3 n coincidence site lattice (CSL) boundaries of alloy 825 tubes could be increased to > 75% by the TMP of 5% cold drawing and subsequent annealing at 1050 °C for 10 min. The microstructures of the partially recrystallized samples and the fully recrystallized samples suggested that the proportion of low ∑ CSL grain boundaries depended on the annealing time. The frequency of low ∑ CSL grain boundaries increases rapidly with increasing annealing time associating with the formation of large-size highly-twinned grains-cluster microstructure during recrystallization. However, upon further increasing annealing time, the frequency of low ∑ CSL grain boundaries decreased markedly during grain growth. So it is concluded that grain boundary engineering is achieved through recrystallization rather than grain growth. - Highlights: •The grain boundary engineering (GBE) is applicable to 825 tubes. •GBE is achieved through recrystallization rather than grain growth. •The low ∑ CSL grain boundaries in 825 tubes can be increased to > 75%.

  18. Grain-to-grain variations in NbC particle size distributions in an austenitic stainless steel

    Barlow, C.Y.; Ralph, B.; Silverman, B.; Jones, A.R.

    1979-01-01

    Quantitative information has been obtained concerning the size distributions of NbC precipitate particles in different grains in a deformed and aged austenitic stainless steel specimen. The precipitate size distributions obtained differ from one grain to another. The average disparity measured between the mean precipitate sizes was a function of the distance between the grains compared. The results obtained are considered in terms of differences in precipitation behaviour due to variations in the levels of plastic strain in constituent grains of the deformed specimen. (author)

  19. Grain size distributions and their effects on auto-acoustic compaction

    Taylor, S.; Brodsky, E. E.

    2013-12-01

    dependent on the largest grain sizes present in the mixture. Establishing governing rules for how mixtures of grain sizes interact will aid our understanding of how the different fault gouge configurations and size distributions observed in natural systems affect shear behavior and earthquake stability on faults.

  20. Size distribution of dust grains: A problem of self-similarity

    Henning, TH.; Dorschner, J.; Guertler, J.

    1989-01-01

    Distribution functions describing the results of natural processes frequently show the shape of power laws. It is an open question whether this behavior is a result simply coming about by the chosen mathematical representation of the observational data or reflects a deep-seated principle of nature. The authors suppose the latter being the case. Using a dust model consisting of silicate and graphite grains Mathis et al. (1977) showed that the interstellar extinction curve can be represented by taking a grain radii distribution of power law type n(a) varies as a(exp -p) with 3.3 less than or equal to p less than or equal to 3.6 (example 1) as a basis. A different approach to understanding power laws like that in example 1 becomes possible by the theory of self-similar processes (scale invariance). The beta model of turbulence (Frisch et al., 1978) leads in an elementary way to the concept of the self-similarity dimension D, a special case of Mandelbrot's (1977) fractal dimension. In the frame of this beta model, it is supposed that on each stage of a cascade the system decays to N clumps and that only the portion beta N remains active further on. An important feature of this model is that the active eddies become less and less space-filling. In the following, the authors assume that grain-grain collisions are such a scale-invarient process and that the remaining grains are the inactive (frozen) clumps of the cascade. In this way, a size distribution n(a) da varies as a(exp -(D+1))da (example 2) results. It seems to be highly probable that the power law character of the size distribution of interstellar dust grains is the result of a self-similarity process. We can, however, not exclude that the process leading to the interstellar grain size distribution is not fragmentation at all

  1. Passive acoustic measurement of bedload grain size distribution using self-generated noise

    T. Petrut

    2018-01-01

    Full Text Available Monitoring sediment transport processes in rivers is of particular interest to engineers and scientists to assess the stability of rivers and hydraulic structures. Various methods for sediment transport process description were proposed using conventional or surrogate measurement techniques. This paper addresses the topic of the passive acoustic monitoring of bedload transport in rivers and especially the estimation of the bedload grain size distribution from self-generated noise. It discusses the feasibility of linking the acoustic signal spectrum shape to bedload grain sizes involved in elastic impacts with the river bed treated as a massive slab. Bedload grain size distribution is estimated by a regularized algebraic inversion scheme fed with the power spectrum density of river noise estimated from one hydrophone. The inversion methodology relies upon a physical model that predicts the acoustic field generated by the collision between rigid bodies. Here we proposed an analytic model of the acoustic energy spectrum generated by the impacts between a sphere and a slab. The proposed model computes the power spectral density of bedload noise using a linear system of analytic energy spectra weighted by the grain size distribution. The algebraic system of equations is then solved by least square optimization and solution regularization methods. The result of inversion leads directly to the estimation of the bedload grain size distribution. The inversion method was applied to real acoustic data from passive acoustics experiments realized on the Isère River, in France. The inversion of in situ measured spectra reveals good estimations of grain size distribution, fairly close to what was estimated by physical sampling instruments. These results illustrate the potential of the hydrophone technique to be used as a standalone method that could ensure high spatial and temporal resolution measurements for sediment transport in rivers.

  2. Passive acoustic measurement of bedload grain size distribution using self-generated noise

    Petrut, Teodor; Geay, Thomas; Gervaise, Cédric; Belleudy, Philippe; Zanker, Sebastien

    2018-01-01

    Monitoring sediment transport processes in rivers is of particular interest to engineers and scientists to assess the stability of rivers and hydraulic structures. Various methods for sediment transport process description were proposed using conventional or surrogate measurement techniques. This paper addresses the topic of the passive acoustic monitoring of bedload transport in rivers and especially the estimation of the bedload grain size distribution from self-generated noise. It discusses the feasibility of linking the acoustic signal spectrum shape to bedload grain sizes involved in elastic impacts with the river bed treated as a massive slab. Bedload grain size distribution is estimated by a regularized algebraic inversion scheme fed with the power spectrum density of river noise estimated from one hydrophone. The inversion methodology relies upon a physical model that predicts the acoustic field generated by the collision between rigid bodies. Here we proposed an analytic model of the acoustic energy spectrum generated by the impacts between a sphere and a slab. The proposed model computes the power spectral density of bedload noise using a linear system of analytic energy spectra weighted by the grain size distribution. The algebraic system of equations is then solved by least square optimization and solution regularization methods. The result of inversion leads directly to the estimation of the bedload grain size distribution. The inversion method was applied to real acoustic data from passive acoustics experiments realized on the Isère River, in France. The inversion of in situ measured spectra reveals good estimations of grain size distribution, fairly close to what was estimated by physical sampling instruments. These results illustrate the potential of the hydrophone technique to be used as a standalone method that could ensure high spatial and temporal resolution measurements for sediment transport in rivers.

  3. GIS-based spatial decision support system for grain logistics management

    Zhen, Tong; Ge, Hongyi; Jiang, Yuying; Che, Yi

    2010-07-01

    Grain logistics is the important component of the social logistics, which can be attributed to frequent circulation and the great quantity. At present time, there is no modern grain logistics distribution management system, and the logistics cost is the high. Geographic Information Systems (GIS) have been widely used for spatial data manipulation and model operations and provide effective decision support through its spatial database management capabilities and cartographic visualization. In the present paper, a spatial decision support system (SDSS) is proposed to support policy makers and to reduce the cost of grain logistics. The system is composed of two major components: grain logistics goods tracking model and vehicle routing problem optimization model and also allows incorporation of data coming from external sources. The proposed system is an effective tool to manage grain logistics in order to increase the speed of grain logistics and reduce the grain circulation cost.

  4. Some regularity of the grain size distribution in nuclear fuel with controllable structure

    Loktev, Igor

    2008-01-01

    It is known, the fission gas release from ceramic nuclear fuel depends from average size of grains. To increase grain size they use additives which activate sintering of pellets. However, grain size distribution influences on fission gas release also. Fuel with different structures, but with the same average size of grains has different fission gas release. Other structure elements, which influence operational behavior of fuel, are pores and inclusions. Earlier, in Kyoto, questions of distribution of grain size for fuel with 'natural' structure were discussed. Some regularity of grain size distribution of fuel with controllable structure and high average size of grains are considered in the report. Influence of inclusions and pores on an error of the automated definition of parameters of structure is shown. The criterion, which describe of behavior of fuel with specific grain size distribution, is offered

  5. Effect of grain refinement by severe plastic deformation on the next-neighbor misorientation distribution

    Toth, L.S.; Beausir, B.; Gu, C.F.; Estrin, Y.; Scheerbaum, N.; Davies, C.H.J.

    2010-01-01

    Next-neighbor misorientation distributions (NNMD) in severely deformed polycrystalline materials are commonly measured by orientation imaging. A procedure is proposed which enables the separation of NNMD of ultrafine-grained materials into two parts: the distribution of misorientations between newly emerged grains within the original ('parent') grain interior ('internal daughter grains') and the distribution of misorientations between grains adjacent to an original grain boundary on its opposite sides ('grain boundary daughter grains'). The procedure is based on electron backscatter diffraction orientation map analyses carried out on different planes of deformed samples considering the evolution of the grain size and shape during severe plastic deformation. It was applied to copper processed by up to three passes of equal-channel angular pressing. A characteristic feature of the measured NNMD is the occurrence of a double peak, which is clearly due to the differences between the NNMD of the two distinct populations of new grains defined above. The peak at low angles represents mainly the continual grain subdivision process in the interior of a parent grain (and is associated with internal daughter grains), while the peak at large angles is due to the high angle misorientations of the grain boundary daughter grains.

  6. THE EFFECTS OF GRAIN SIZE AND TEMPERATURE DISTRIBUTIONS ON THE FORMATION OF INTERSTELLAR ICE MANTLES

    Pauly, Tyler; Garrod, Robin T., E-mail: tap74@cornell.edu [Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853-6801 (United States)

    2016-02-01

    Computational models of interstellar gas-grain chemistry have historically adopted a single dust-grain size of 0.1 micron, assumed to be representative of the size distribution present in the interstellar medium. Here, we investigate the effects of a broad grain-size distribution on the chemistry of dust-grain surfaces and the subsequent build-up of molecular ices on the grains, using a three-phase gas-grain chemical model of a quiescent dark cloud. We include an explicit treatment of the grain temperatures, governed both by the visual extinction of the cloud and the size of each individual grain-size population. We find that the temperature difference plays a significant role in determining the total bulk ice composition across the grain-size distribution, while the effects of geometrical differences between size populations appear marginal. We also consider collapse from a diffuse to a dark cloud, allowing dust temperatures to fall. Under the initial diffuse conditions, small grains are too warm to promote grain-mantle build-up, with most ices forming on the mid-sized grains. As collapse proceeds, the more abundant, smallest grains cool and become the dominant ice carriers; the large population of small grains means that this ice is distributed across many grains, with perhaps no more than 40 monolayers of ice each (versus several hundred assuming a single grain size). This effect may be important for the subsequent processing and desorption of the ice during the hot-core phase of star formation, exposing a significant proportion of the ice to the gas phase, increasing the importance of ice-surface chemistry and surface–gas interactions.

  7. The Effects of Grain Size and Temperature Distributions on the Formation of Interstellar Ice Mantles

    Pauly, Tyler; Garrod, Robin T.

    2016-02-01

    Computational models of interstellar gas-grain chemistry have historically adopted a single dust-grain size of 0.1 micron, assumed to be representative of the size distribution present in the interstellar medium. Here, we investigate the effects of a broad grain-size distribution on the chemistry of dust-grain surfaces and the subsequent build-up of molecular ices on the grains, using a three-phase gas-grain chemical model of a quiescent dark cloud. We include an explicit treatment of the grain temperatures, governed both by the visual extinction of the cloud and the size of each individual grain-size population. We find that the temperature difference plays a significant role in determining the total bulk ice composition across the grain-size distribution, while the effects of geometrical differences between size populations appear marginal. We also consider collapse from a diffuse to a dark cloud, allowing dust temperatures to fall. Under the initial diffuse conditions, small grains are too warm to promote grain-mantle build-up, with most ices forming on the mid-sized grains. As collapse proceeds, the more abundant, smallest grains cool and become the dominant ice carriers; the large population of small grains means that this ice is distributed across many grains, with perhaps no more than 40 monolayers of ice each (versus several hundred assuming a single grain size). This effect may be important for the subsequent processing and desorption of the ice during the hot-core phase of star formation, exposing a significant proportion of the ice to the gas phase, increasing the importance of ice-surface chemistry and surface-gas interactions.

  8. Grain Size Distribution in Mudstones: A Question of Nature vs. Nurture

    Schieber, J.

    2011-12-01

    distributions in mudstones evolve is considered central to problems in hillslope, fluvial, aeolian, coastal, and submarine systems, one can not simply measure distributions and hope to arrive at an answer. The complex origins of mudstones are reflected in their very broad compositional range, and multiple overprinted processes have to be considered in order to make sense out of observed grain size distributions.

  9. Notes on representing grain size distributions obtained by electron backscatter diffraction

    Toth, Laszlo S.; Biswas, Somjeet; Gu, Chengfan; Beausir, Benoit

    2013-01-01

    Grain size distributions measured by electron backscatter diffraction are commonly represented by histograms using either number or area fraction definitions. It is shown here that they should be presented in forms of density distribution functions for direct quantitative comparisons between different measurements. Here we make an interpretation of the frequently seen parabolic tales of the area distributions of bimodal grain structures and a transformation formula between the two distributions are given in this paper. - Highlights: • Grain size distributions are represented by density functions. • The parabolic tales corresponds to equal number of grains in a bin of the histogram. • A simple transformation formula is given to number and area weighed distributions. • The particularities of uniform and lognormal distributions are examined

  10. Species distribution model transferability and model grain size - finer may not always be better.

    Manzoor, Syed Amir; Griffiths, Geoffrey; Lukac, Martin

    2018-05-08

    Species distribution models have been used to predict the distribution of invasive species for conservation planning. Understanding spatial transferability of niche predictions is critical to promote species-habitat conservation and forecasting areas vulnerable to invasion. Grain size of predictor variables is an important factor affecting the accuracy and transferability of species distribution models. Choice of grain size is often dependent on the type of predictor variables used and the selection of predictors sometimes rely on data availability. This study employed the MAXENT species distribution model to investigate the effect of the grain size on model transferability for an invasive plant species. We modelled the distribution of Rhododendron ponticum in Wales, U.K. and tested model performance and transferability by varying grain size (50 m, 300 m, and 1 km). MAXENT-based models are sensitive to grain size and selection of variables. We found that over-reliance on the commonly used bioclimatic variables may lead to less accurate models as it often compromises the finer grain size of biophysical variables which may be more important determinants of species distribution at small spatial scales. Model accuracy is likely to increase with decreasing grain size. However, successful model transferability may require optimization of model grain size.

  11. Drinking Water Distribution Systems

    Learn about an overview of drinking water distribution systems, the factors that degrade water quality in the distribution system, assessments of risk, future research about these risks, and how to reduce cross-connection control risk.

  12. The effect of surface albedo and grain size distribution on ...

    Sand dams are very useful in arid and semi arid lands (ASALs) as facilities for water storage and conservation. Soils in ASALs are mainly sandy and major water loss is by evaporation and infiltration. This study investigated the effect of sand media characteristics, specifically surface albedo, grain size and stratification on ...

  13. Different Phosphorus Supplies Altered the Accumulations and Quantitative Distributions of Phytic Acid, Zinc, and Iron in Rice (Oryza sativa L.) Grains.

    Su, Da; Zhou, Lujian; Zhao, Qian; Pan, Gang; Cheng, Fangmin

    2018-02-21

    Development of rice cultivars with low phytic acid (lpa) is considered as a primary strategy for biofortification of zinc (Zn) and iron (Fe). Here, two rice genotypes (XS110 and its lpa mutant) were used to investigate the effect of P supplies on accumulations and distributions of PA, Zn, and Fe in rice grains by using hydroponics and detached panicle culture system. Results showed that higher P level increased grain PA concentration on dry matter basis (g/kg), but it markedly decreased PA accumulation on per grain basis (mg/grain). Meanwhile, more P supply reduced the amounts and bioavailabilities of Zn and Fe both in milled grains and in brown grains. Comparatively, lpa mutant was more susceptive to exogenous P supply than its wild type. Hence, the appropriate P fertilizer application should be highlighted in order to increase grain microelement (Zn and Fe) contents and improve nutritional quality in rice grains.

  14. The magnetized sheath of a dusty plasma with grains size distribution

    Ou, Jing; Gan, Chunyun; Lin, Binbin; Yang, Jinhong

    2015-01-01

    The structure of a plasma sheath in the presence of dust grains size distribution (DGSD) is investigated in the multi-fluid framework. It is shown that effect of the dust grains with different sizes on the sheath structure is a collective behavior. The spatial distributions of electric potential, the electron and ion densities and velocities, and the dust grains surface potential are strongly affected by DGSD. The dynamics of dust grains with different sizes in the sheath depend on not only DGSD but also their radius. By comparison of the sheath structure, it is found that under the same expected value of DGSD condition, the sheath length is longer in the case of lognormal distribution than that in the case of uniform distribution. In two cases of normal and lognormal distributions, the sheath length is almost equal for the small variance of DGSD, and then the difference of sheath length increases gradually with increase in the variance

  15. Size Distribution and Rate of Dust Generated During Grain Elevator Handling

    Dust generated during grain handling is an air pollutant that produces safety and health hazards. This study was conducted to characterize the particle size distribution (PSD) of dust generated during handling of wheat and shelled corn in the research elevator of the USDA Grain Marketing and Product...

  16. Environmental monitoring of Columbia River sediments: Grain-size distribution and contaminant association

    Blanton, M.L.; Gardiner, W.W.; Dirkes, R.L.

    1995-04-01

    Based on the results of this study and literature review, the following conclusions can be made: Sediment grain size and TOC (total organic carbon) influence contaminant fate and transport (in general, sediments with higher TOC content and finer grain-size distribution can have higher contaminant burdens than sediments from a given river section that have less TOC and greater amounts of coarse-grained sediments). Physiochemical sediment characteristics are highly variable among monitoring sites along the Columbia River. Sediment grain characterization and TOC analysis should be included in interpretations of sediment-monitoring data.

  17. Environmental monitoring of Columbia River sediments: Grain-size distribution and contaminant association

    Blanton, M.L.; Gardiner, W.W.; Dirkes, R.L.

    1995-04-01

    Based on the results of this study and literature review, the following conclusions can be made: Sediment grain size and TOC (total organic carbon) influence contaminant fate and transport (in general, sediments with higher TOC content and finer grain-size distribution can have higher contaminant burdens than sediments from a given river section that have less TOC and greater amounts of coarse-grained sediments). Physiochemical sediment characteristics are highly variable among monitoring sites along the Columbia River. Sediment grain characterization and TOC analysis should be included in interpretations of sediment-monitoring data

  18. Grain refinement and hardness distribution in cryogenically cooled ferritic stainless steel welds

    Amuda, M.O.H.; Mridha, S.

    2013-01-01

    Highlights: ► Grain refinement was undertaken in AISI 430 FSS welds using cryogenic cooling. ► Flow rates of the cryogenic liquid influenced weld grain structure. ► Cryogenic cooling of welds generates about 45% grain refinement in welds. ► Phase structure of welds is not affected by flow rates of cryogenic liquid. ► Hardness profile in cryogenically cooled and conventional welds is similar. - Abstract: The energy input and heat dissipation dynamics during fusion welding generates coarse grain in the welds resulting in poor mechanical properties. While grain refinement in welds via the control of the energy input is quite common, the influence of heat dissipation on grain morphology and properties is not fully established. This paper characterized cryogenically cooled ferritic stainless steel (FSS) welds in terms of grain structure and hardness distribution along transverse and thickness directions. Cryogenic cooling reduces the weld dimension by more than 30% and provides grain refinement of almost 45% compared to conventional weld. The hardness distribution in the thickness direction gives slightly higher profile because of decreased grain growth caused by faster cooling effects of cryogenic liquid

  19. Effect of noise-induced nucleation on grain size distribution studied via the phase-field crystal method

    Hubert, J; Cheng, M; Emmerich, H

    2009-01-01

    We contribute to the more detailed understanding of the phase-field crystal model recently developed by Elder et al (2002 Phys. Rev. Lett. 88 245701), by focusing on its noise term and examining its impact on the nucleation rate in a homogeneously solidifying system as well as on successively developing grain size distributions. In this context we show that principally the grain size decreases with increasing noise amplitude, resulting in both a smaller average grain size and a decreased maximum grain size. Despite this general tendency, which we interpret based on Panfilis and Filiponi (2000 J. Appl. Phys. 88 562), we can identify two different regimes in which nucleation and successive initial growth are governed by quite different mechanisms.

  20. Grain-size dependent accommodation due to intragranular distributions of dislocation loops

    Richeton, T.; Berbenni, S.; Berveiller, M.

    2009-01-01

    A grain-size dependent accommodation law for polycrystals is deduced from an inclusion/matrix problem (i.e., each grain is seen as embedded in a homogeneous equivalent medium) where plastic strain inside the inclusion is given as a discrete distribution of circular coaxial glide dislocation loops. The loops are assumed constrained at spherical grain boundaries. From thermodynamic considerations specific to a process of identical plastification in all the loops (considered as 'super-dislocations'), an average back-stress over the grain is derived. In order to compute the very early stages of plastic deformation in a face-centred cubic polycrystal, this back-stress is incorporated into a diluted model in terms of concentration of plastic grains. Contrary to conventional mean-field approaches, a grain-size effect is obtained for the initial overall strain-hardening behaviour. This size effect results from an intrinsic contribution of intragranular slip heterogeneities on the kinematical hardening

  1. NON-COHESIVE SOILS’ COMPRESSIBILITY AND UNEVEN GRAIN-SIZE DISTRIBUTION RELATION

    Anatoliy Mirnyy

    2016-03-01

    Full Text Available This paper presents the results of laboratory investigation of soil compression phases with consideration of various granulometric composition. Materials and Methods Experimental soil box with microscale video recording for compression phases studies is described. Photo and video materials showing the differences of microscale particle movements were obtained for non-cohesive soils with different grain-size distribution. Results The analysis of the compression tests results and elastic and plastic deformations separation allows identifying each compression phase. It is shown, that soil density is correlating with deformability parameters only for the same grain-size distribution. Basing on the test results the authors suggest that compaction ratio is not sufficient for deformability estimating without grain-size distribution taken into account. Discussion and Conclusions Considering grain-size distribution allows refining technological requirements for artificial soil structures, backfills, and sand beds. Further studies could be used for developing standard documents, SP45.13330.2012 in particular.

  2. ON ESTIMATION AND HYPOTHESIS TESTING OF THE GRAIN SIZE DISTRIBUTION BY THE SALTYKOV METHOD

    Yuri Gulbin

    2011-05-01

    Full Text Available The paper considers the problem of validity of unfolding the grain size distribution with the back-substitution method. Due to the ill-conditioned nature of unfolding matrices, it is necessary to evaluate the accuracy and precision of parameter estimation and to verify the possibility of expected grain size distribution testing on the basis of intersection size histogram data. In order to review these questions, the computer modeling was used to compare size distributions obtained stereologically with those possessed by three-dimensional model aggregates of grains with a specified shape and random size. Results of simulations are reported and ways of improving the conventional stereological techniques are suggested. It is shown that new improvements in estimating and testing procedures enable grain size distributions to be unfolded more efficiently.

  3. Ensuring sustainable grain legume-cereal cropping systems

    Bedoussac, Laurent; Journet, E-P; Hauggaard-Nielsen, Henrik

    2017-01-01

    health makes them a key rotation crop in the sustainable intensification and diversification of smallholder farming. This makes grain legumes a key food security crop. However, yields in developing countries are low as a result of such factors as the need for improved varieties of seed, poor seed......Grain legumes are widely cultivated, particularly for their dry seeds (known as pulses). Grain legumes are an important crop for a number of reasons. They are a rich source of protein and fibre, minerals and vitamins. In addition, their rapid growth and ability to fix nitrogen and improve soil...... distribution, the impact of pests and diseases, as well as vulnerability to poor soils, drought and other effects of climate change. This chapter summarises data from over 50 field experiments undertaken since 2001 on cereal-grain legume intercropping in 13 sites in southern and western France as well...

  4. Effect of texture on grain boundary misorientation distributions in polycrystalline high temperature superconductors

    Goyal, A.; Specht, E.D.; Kroeger, D.M.; Mason, T.A.

    1996-01-01

    Computer simulations were performed to determine the most probable grain boundary misorientation distribution (GBMD) in model polycrystalline superconductors. GBMDs in polycrystalline superconductors can be expected to dictate the macroscopic transport critical current density, J c . Calculations were performed by simulating model polycrystals and then determining the GBMD. Such distributions were calculated for random materials having cubic, tetragonal, and orthorhombic crystal symmetry. In addition, since most high temperature superconductors are tetragonal or pseudotetragonal, the effect of macroscopic uniaxial and biaxial grain orientation texture on the GBMD was determined for tetragonal materials. It is found that macroscopic texture drastically alters the grain boundary misorientation distribution. The fraction of low angle boundaries increases significantly with uniaxial and biaxial texture. The results of this study are important in correlating the macroscopic transport J c with the measured grain orientation texture as determined by x-ray diffraction copyright 1996 American Institute of Physics

  5. Smart Distribution Systems

    Yazhou Jiang

    2016-04-01

    Full Text Available The increasing importance of system reliability and resilience is changing the way distribution systems are planned and operated. To achieve a distribution system self-healing against power outages, emerging technologies and devices, such as remote-controlled switches (RCSs and smart meters, are being deployed. The higher level of automation is transforming traditional distribution systems into the smart distribution systems (SDSs of the future. The availability of data and remote control capability in SDSs provides distribution operators with an opportunity to optimize system operation and control. In this paper, the development of SDSs and resulting benefits of enhanced system capabilities are discussed. A comprehensive survey is conducted on the state-of-the-art applications of RCSs and smart meters in SDSs. Specifically, a new method, called Temporal Causal Diagram (TCD, is used to incorporate outage notifications from smart meters for enhanced outage management. To fully utilize the fast operation of RCSs, the spanning tree search algorithm is used to develop service restoration strategies. Optimal placement of RCSs and the resulting enhancement of system reliability are discussed. Distribution system resilience with respect to extreme events is presented. Test cases are used to demonstrate the benefit of SDSs. Active management of distributed generators (DGs is introduced. Future research in a smart distribution environment is proposed.

  6. Electric distribution systems

    Sallam, A A

    2010-01-01

    "Electricity distribution is the penultimate stage in the delivery of electricity to end users. The only book that deals with the key topics of interest to distribution system engineers, Electric Distribution Systems presents a comprehensive treatment of the subject with an emphasis on both the practical and academic points of view. Reviewing traditional and cutting-edge topics, the text is useful to practicing engineers working with utility companies and industry, undergraduate graduate and students, and faculty members who wish to increase their skills in distribution system automation and monitoring."--

  7. Distributed Operating Systems

    Mullender, Sape J.

    1987-01-01

    In the past five years, distributed operating systems research has gone through a consolidation phase. On a large number of design issues there is now considerable consensus between different research groups. In this paper, an overview of recent research in distributed systems is given. In turn, the

  8. Pervasive Electricity Distribution System

    Muhammad Usman Tahir

    2017-06-01

    Full Text Available Now a days a country cannot become economically strong until and unless it has enough electrical power to fulfil industrial and domestic needs. Electrical power being the pillar of any country’s economy, needs to be used in an efficient way. The same step is taken here by proposing a new system for energy distribution from substation to consumer houses, also it monitors the consumer consumption and record data. Unlike traditional manual Electrical systems, pervasive electricity distribution system (PEDS introduces a fresh perspective to monitor the feeder line status at distribution and consumer level. In this system an effort is taken to address the issues of electricity theft, manual billing, online monitoring of electrical distribution system and automatic control of electrical distribution points. The project is designed using microcontroller and different sensors, its GUI is designed in Labview software.

  9. [Characteristics and its forming mechanism on grain size distribution of suspended matter at Changjiang Estuary].

    Pang, Chong-guang; Yu, Wei; Yang, Yang

    2010-03-01

    In July of 2008, under the natural condition of sea water, the Laser in-situ scattering and transmissometry (LISST-100X Type C) was used to measure grain size distribution spectrum and volume concentration of total suspended matter in the sea water, including flocs at different layers of 24 sampling stations at Changjiang Estuary and its adjacent sea. The characteristics and its forming mechanism on grain size distribution of total suspended matter were analyzed based on the observation data of LISST-100X Type C, and combining with the temperature, salinity and turbidity of sea water, simultaneously observed by Alec AAQ1183. The observation data showed that the average median grain size of total suspended matter was about 4.69 phi in the whole measured sea area, and the characteristics of grain size distribution was relatively poor sorted, wide kurtosis, and basically symmetrical. The conclusion could be drawn that vertically average volume concentration decreased with the distance from the coastline, while median grain size had an increase trend with the distance, for example, at 31.0 degrees N section, the depth-average median grain size had been increased from 11 microm up to 60 microm. With the increasing of distance from the coast, the concentration of fine suspended sediment reduced distinctly, nevertheless some relatively big organic matter or big flocs appeared in quantity, so its grain size would rise. The observation data indicated that the effective density was ranged from 246 kg/m3 to 1334 kg/m, with average was 613 kg/m3. When the concentration of total suspended matter was relatively high, median grain size of total suspended matter increased with the water depth, while effective density decreased with the depth, because of the faster settling velocity and less effective density of large flocs that of small flocs. As for station 37 and 44, their correlation coefficients between effective density and median grain size were larger than 0.9.

  10. In Situ Sampling of Relative Dust Devil Particle Loads and Their Vertical Grain Size Distributions.

    Raack, Jan; Reiss, Dennis; Balme, Matthew R; Taj-Eddine, Kamal; Ori, Gian Gabriele

    2017-04-19

    During a field campaign in the Sahara Desert in southern Morocco, spring 2012, we sampled the vertical grain size distribution of two active dust devils that exhibited different dimensions and intensities. With these in situ samples of grains in the vortices, it was possible to derive detailed vertical grain size distributions and measurements of the lifted relative particle load. Measurements of the two dust devils show that the majority of all lifted particles were only lifted within the first meter (∼46.5% and ∼61% of all particles; ∼76.5 wt % and ∼89 wt % of the relative particle load). Furthermore, ∼69% and ∼82% of all lifted sand grains occurred in the first meter of the dust devils, indicating the occurrence of "sand skirts." Both sampled dust devils were relatively small (∼15 m and ∼4-5 m in diameter) compared to dust devils in surrounding regions; nevertheless, measurements show that ∼58.5% to 73.5% of all lifted particles were small enough to go into suspension (grain size classification). This relatively high amount represents only ∼0.05 to 0.15 wt % of the lifted particle load. Larger dust devils probably entrain larger amounts of fine-grained material into the atmosphere, which can have an influence on the climate. Furthermore, our results indicate that the composition of the surface, on which the dust devils evolved, also had an influence on the particle load composition of the dust devil vortices. The internal particle load structure of both sampled dust devils was comparable related to their vertical grain size distribution and relative particle load, although both dust devils differed in their dimensions and intensities. A general trend of decreasing grain sizes with height was also detected. Key Words: Mars-Dust devils-Planetary science-Desert soils-Atmosphere-Grain sizes. Astrobiology 17, xxx-xxx.

  11. The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

    Thomsen, Kristina Jørkov; Murray, Andrew S.; Jain, Mayank

    2012-01-01

    The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely...... to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution....... This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally...

  12. Cooling water distribution system

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  13. Autonomous bed-sediment imaging-systems for revealing temporal variability of grain size

    Buscombe, Daniel; Rubin, David M.; Lacy, Jessica R.; Storlazzi, Curt D.; Hatcher, Gerald; Chezar, Henry; Wyland, Robert; Sherwood, Christopher R.

    2014-01-01

    We describe a remotely operated video microscope system, designed to provide high-resolution images of seabed sediments. Two versions were developed, which differ in how they raise the camera from the seabed. The first used hydraulics and the second used the energy associated with wave orbital motion. Images were analyzed using automated frequency-domain methods, which following a rigorous partially supervised quality control procedure, yielded estimates to within 20% of the true size as determined by on-screen manual measurements of grains. Long-term grain-size variability at a sandy inner shelf site offshore of Santa Cruz, California, USA, was investigated using the hydraulic system. Eighteen months of high frequency (min to h), high-resolution (μm) images were collected, and grain size distributions compiled. The data constitutes the longest known high-frequency record of seabed-grain size at this sample frequency, at any location. Short-term grain-size variability of sand in an energetic surf zone at Praa Sands, Cornwall, UK was investigated using the ‘wave-powered’ system. The data are the first high-frequency record of grain size at a single location of a highly mobile and evolving bed in a natural surf zone. Using this technology, it is now possible to measure bed-sediment-grain size at a time-scale comparable with flow conditions. Results suggest models of sediment transport at sandy, wave-dominated, nearshore locations should allow for substantial changes in grain-size distribution over time-scales as short as a few hours.

  14. Advanced Distribution Management System

    Avazov, Artur; Sobinova, Lubov Anatolievna

    2016-01-01

    This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

  15. Advanced Distribution Management System

    Avazov, Artur R.; Sobinova, Liubov A.

    2016-02-01

    This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

  16. Advanced Distribution Management System

    Avazov Artur R.

    2016-01-01

    Full Text Available This article describes the advisability of using advanced distribution management systems in the electricity distribution networks area and considers premises of implementing ADMS within the Smart Grid era. Also, it gives the big picture of ADMS and discusses the ADMS advantages and functionalities.

  17. Evidence of sealing and brine distribution at grain boundaries in natural fine-grained Halite (Qum Kuh salt fountain, Central Iran): implications for rheology of salt extrusions

    Desbois, Guillaume; Urai, Janos L.; de Bresser, J. H. P.

    2010-05-01

    When grain boundary movement is stopped, surface energy related forces reassert themselves driving the system to its equilibrium conditions ([2], [6], [7], [8]). This could result in growth of islands and shrinking of channels and hence in healing the boundary by internal redistribution of fluid and solid in the contact region. Such islands are proposed to grow preferentially close to the contact rim and promote the healing of the grain-grain contact, which in turn prevents transport in or out the boundary region and thus traps the fluids in isolated inclusions. This contribution is focused on observation of grain boundary microstructures in natural mylonitic rocksalt collected from the distal part of Kum-Quh salt fountain (central Iran) in order to give unprecedented insight of grain boundary microstructures using argon-beam cross-sectioning to prepare high quality polished surfaces suitable for high-resolution SEM imaging. The possibility to use our SEM under cryogenic conditions allows also imaging the in-situ distribution of fluids. Results show that brine at grain boundaries occurs as thick layers (> µm in scale) corresponding to cross-sectioned wetted triple junction tubes, as filling at triple junction and as array of isolated fluids inclusions at grain-grain contacts. Close observations at islands contacts suggest the presence of a very thin fluid film (Journal of Structural Geology. [2] Ghoussoub J., and Leroy Y.M. (2001), Solid-fluid phase transformation within grain boundaries during compaction by pressure solution, J. Mech. Phys. Solids, 49, 737 2385-2430. 738 [3] Jackson, M.P.A., (1985). Natural strain in diapiric and glacial rock salt, with emphasis on Oakwood dome, East Texas, Bureau of Economic Geology, The University of Texas at Austin, Texas. [4] Schléder Z. and Urai J.L. (2007). Deformation and recrystallization mechanisms in mylonitic shear zones in naturally deformed extrusive Eocene-Oligocene rock salt from Eyvanekey plateau and Garmsar

  18. Forecasting grain size distribution of coal cut by a shearer loader

    Sikora, W; Chodura, J; Siwiec, J

    1983-02-01

    Analyzed are effects of shearer loader design on grain size distribution of coal, particularly on proportion of the finest size group and proportion of largest coal grains. The method developed by the IGD im. A.A. Skochinski Institute in Moscow is used. Effects of cutting tool design and mechanical coal properties are analyzed. Of the evaluated factors, two are of decisive importance: thickness of the coal chip cut by a cutting tool and coefficient of coal disintegration which characterizes coal behavior during cutting. Grain size distribution is also influenced by cutting tool geometry. Two elements of cutting tool design are of major importance: dimensions of the cutting edge and angle of attack. Effects of cutting tool design and coal mechanical properties on grain size distribution are shown in 12 diagrams. Using the forecasting method developed by the IGD im. A.A. Skochinski Institute in Moscow grain size distribution of coal cut by three shearer loaders is calculated: the KWB-3RDU with a drum 1600 mm in diameter, the KWB-6W with a drum 2500 mm in diameter, and a shearer loader being developed with a 1550 mm drum. The results of comparative evaluations are shown in two tables. 5 references.

  19. The effects of particle size distribution and induced unpinning during grain growth

    Thompson, G.S.; Rickman, J.M.; Harmer, M.P.; Holm, E.A.

    1996-01-01

    The effect of a second-phase particle size distribution on grain boundary pinning was studied using a Monte Carlo simulation technique. Simulations were run using a constant number density of both whisker and rhombohedral particles, and the effect of size distribution was studied by varying the standard deviation of the distribution around a constant mean particle size. The results of present simulations indicate that, in accordance with the stereological assumption of the topological pinning model, changes in distribution width had no effect on the pinned grain size. The effect of induced unpinning of particles on microstructure was also studied. In contrast to predictions of the topological pinning model, a power law dependence of pinned grain size on particle size was observed at T=0.0. Based on this, a systematic deviation to the stereological predictions of the topological pinning model is observed. The results of simulations at higher temperatures indicate an increasing power law dependence of pinned grain size on particle size, with the slopes of the power law dependencies fitting an Arrhenius relation. The effect of induced unpinning of particles was also studied in order to obtain a correlation between particle/boundary concentration and equilibrium grain size. The results of simulations containing a constant number density of monosized rhombohedral particles suggest a strong power law correlation between the two parameters. copyright 1996 Materials Research Society

  20. A distribution management system

    Verho, P.; Jaerventausta, P.; Kaerenlampi, M.; Paulasaari, H. [Tampere Univ. of Technology (Finland); Partanen, J. [Lappeenranta Univ. of Technology (Finland)

    1996-12-31

    The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion of the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the vendors of the other systems. In the research project this alternative is preferred and used in developing an independent distribution management system

  1. A distribution management system

    Verho, P; Jaerventausta, P; Kaerenlampi, M; Paulasaari, H [Tampere Univ. of Technology (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

    1997-12-31

    The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion of the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the vendors of the other systems. In the research project this alternative is preferred and used in developing an independent distribution management system

  2. The mechanical behavior of metal alloys with grain size distribution in a wide range of strain rates

    Skripnyak, V. A.; Skripnyak, V. V.; Skripnyak, E. G.

    2017-12-01

    The paper discusses a multiscale simulation approach for the construction of grain structure of metals and alloys, providing high tensile strength with ductility. This work compares the mechanical behavior of light alloys and the influence of the grain size distribution in a wide range of strain rates. The influence of the grain size distribution on the inelastic deformation and fracture of aluminium and magnesium alloys is investigated by computer simulations in a wide range of strain rates. It is shown that the yield stress depends on the logarithm of the normalized strain rate for light alloys with a bimodal grain distribution and coarse-grained structure.

  3. A distribution management system

    Jaerventausta, P; Verho, P; Kaerenlampi, M; Pitkaenen, M [Tampere Univ. of Technology (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)

    1998-08-01

    The development of new distribution automation applications is considerably wide nowadays. One of the most interesting areas is the development of a distribution management system (DMS) as an expansion to the traditional SCADA system. At the power transmission level such a system is called an energy management system (EMS). The idea of these expansions is to provide supporting tools for control center operators in system analysis and operation planning. Nowadays the SCADA is the main computer system (and often the only) in the control center. However, the information displayed by the SCADA is often inadequate, and several tasks cannot be solved by a conventional SCADA system. A need for new computer applications in control center arises from the insufficiency of the SCADA and some other trends. The latter means that the overall importance of the distribution networks is increasing. The slowing down of load-growth has often made network reinforcements unprofitable. Thus the existing network must be operated more efficiently. At the same time larger distribution areas are for economical reasons being monitored at one control center and the size of the operation staff is decreasing. The quality of supply requirements are also becoming stricter. The needed data for new applications is mainly available in some existing systems. Thus the computer systems of utilities must be integrated. The main data source for the new applications in the control center are the AM/FM/GIS (i.e. the network database system), the SCADA, and the customer information system (CIS). The new functions can be embedded in some existing computer system. This means a strong dependency on the vendor of the existing system. An alternative strategy is to develop an independent system which is integrated with other computer systems using well-defined interfaces. The latter approach makes it possible to use the new applications in various computer environments, having only a weak dependency on the

  4. Grain Orientation and Interface Character Distribution During Austenite Precipitation Phase in Duplex Stainless Steel

    XU Ting

    2018-02-01

    Full Text Available The grain orientation and the interface character distribution were investigated for γ precipitation from the supersaturated α during aging at 1323K in duplex stainless steel by using EBSD technique and misorientation analysis based on Rodrigues-Frank (R-F space. The results show that sharp texture and the grain boundary character distribution featured by a high population of low angle grain boundary (LAB and a small number of twin boundaries (TBs are produced in the γ precipitated from cold-rolled supersaturated coarse α with pre-strain of ε=2. The precipitated γ grains approximately possess K-S, N-W and Bain orientation relationship with the α matrix equally. For the unstrained α matrix of the same orientation, nearly random texture and the grain boundary character predominated by TBs are introduced in the γ precipitation after aging. Most of γ have K-S relation with the α matrix. However, twining in γ leads to the deviation from typical K-S orientation relationship. And also, one-fourth of phase boundaries along γ grains containing twins are found to obey a new orientation relationship of 35°/〈110〉 with α matrix.

  5. The Andatza coarse-grained turbidite system (westernmost Pyrenees: Stratigraphy, sedimentology and structural control

    A. Bodego

    2017-06-01

    Full Text Available This is a field-based work that describes the stratigraphy and sedimentology of the Andatza Conglomerate Formation. Based on facies analysis three facies associations of a coarse-grained turbidite system and the related slope have been identified: (1 an inner fan of a turbidite system (or canyon and (2 a low- and (3 a high-gradient muddy slope respectively. The spatial distribution of the facies associations and the palaeocurrent analysis allow to interpret a depositional model for the Andatza Conglomerates consisting of an L-shaped, coarse-grained turbidite system, whose morphology was structurally controlled by synsedimentary basement-involved normal faults. The coarse-grained character of the turbidite system indicates the proximity of the source area, with the presence of a narrow shelf that fed the turbidite canyon from the north.

  6. SILICON CARBIDE GRAIN BOUNDARY DISTRIBUTIONS, IRRADIATION CONDITIONS, AND SILVER RETENTION IN IRRADIATED AGR-1 TRISO FUEL PARTICLES

    Lillo, T. M.; Rooyen, I. J.; Aguiar, J. A.

    2016-11-01

    Precession electron diffraction in the transmission electron microscope was used to map grain orientation and ultimately determine grain boundary misorientation angle distributions, relative fractions of grain boundary types (random high angle, low angle or coincident site lattice (CSL)-related boundaries) and the distributions of CSL-related grain boundaries in the SiC layer of irradiated TRISO-coated fuel particles. Two particles from the AGR-1 experiment exhibiting high Ag-110m retention (>80%) were compared to a particle exhibiting low Ag-110m retention (<19%). Irradiated particles with high Ag-110m retention exhibited a lower fraction of random, high angle grain boundaries compared to the low Ag-110m retention particle. An inverse relationship between the random, high angle grain boundary fraction and Ag-110m retention is found and is consistent with grain boundary percolation theory. Also, comparison of the grain boundary distributions with previously reported unirradiated grain boundary distributions, based on SEM-based EBSD for similarly fabricated particles, showed only small differences, i.e. a greater low angle grain boundary fraction in unirradiated SiC. It was, thus, concluded that SiC layers with grain boundary distributions susceptible to Ag-110m release were present prior to irradiation. Finally, irradiation parameters were found to have little effect on the association of fission product precipitates with specific grain boundary types.

  7. Distributed processor systems

    Zacharov, B.

    1976-01-01

    In recent years, there has been a growing tendency in high-energy physics and in other fields to solve computational problems by distributing tasks among the resources of inter-coupled processing devices and associated system elements. This trend has gained further momentum more recently with the increased availability of low-cost processors and with the development of the means of data distribution. In two lectures, the broad question of distributed computing systems is examined and the historical development of such systems reviewed. An attempt is made to examine the reasons for the existence of these systems and to discern the main trends for the future. The components of distributed systems are discussed in some detail and particular emphasis is placed on the importance of standards and conventions in certain key system components. The ideas and principles of distributed systems are discussed in general terms, but these are illustrated by a number of concrete examples drawn from the context of the high-energy physics environment. (Auth.)

  8. Distributed Treatment Systems.

    Zgonc, David; Plante, Luke

    2017-10-01

    This section presents a review of the literature published in 2016 on topics relating to distributed treatment systems. This review is divided into the following sections with multiple subsections under each: constituent removal; treatment technologies; and planning and treatment system management.

  9. Distributed Computerized Catalog System

    Borgen, Richard L.; Wagner, David A.

    1995-01-01

    DarkStar Distributed Catalog System describes arbitrary data objects in unified manner, providing end users with versatile, yet simple search mechanism for locating and identifying objects. Provides built-in generic and dynamic graphical user interfaces. Design of system avoids some of problems of standard DBMS, and system provides more flexibility than do conventional relational data bases, or object-oriented data bases. Data-collection lattice partly hierarchical representation of relationships among collections, subcollections, and data objects.

  10. Bimodal grain-size distribution of Chinese loess, and its palaeoclimatic implications

    Sun, D.G.; Bloemendal, J.; Rea, D.K.; An, Z.S.; Vandenberghe, J.; Lu, H.; Su, R.; Liu, T.S.

    2004-01-01

    Grain-size analysis indicates that Chinese loess generally shows a bimodal distribution with a coarse and a fine component. The coarse component, comprising the main part of the loess, has pronounced kurtosis and is well sorted, which is interpreted to be the product of dust storms generated by

  11. Significant effect of grain size distribution on compaction rates in granular aggregates

    Niemeijer, André|info:eu-repo/dai/nl/370832132; Elsworth, Derek; Marone, Chris

    2009-01-01

    We investigate the role of pressure solution in deformation of upper- to mid-crustal rocks using aggregates of halite as a room temperature analog for fluid-assisted deformation processes in the Earth's crust. Experiments evaluate the effects of initial grain size distribution on macroscopic

  12. Effects of high hydrostatic pressure on distribution dynamics of free amino acids in water soaked brown rice grain

    Shigematsu, T.; Hayashi, M.; Nakajima, K.; Uno, Y.; Sakano, A.; Murakami, M.; Narahara, Y.; Ueno, S.; Fujii, T.

    2010-03-01

    High hydrostatic pressure (HP) with approximately below 400 MPa can induce a transformation of food materials to an alternative form, where membrane systems are damaged but certain enzymes are still active. HP treatment of water soaked brown rice grain could modify the mass transfer inside and apparent activities of enzymes, resulting in HP-dependent change of distribution of free amino acids. Thus, the distribution of free amino acids in brown rice grain during preservation after HP treatment was analyzed. Just after HP treatment at 200 MPa for 10 min, the distribution of free amino acids was not apparently different from that of untreated control. In contrast, after 1 to 4 days preservation at 25°C, amino acids, such as Ala, Glu, Gly, Asp and Val, showed higher concentrations than those in control. This result suggested that HP treatment induced proteolysis to produce free amino acids. However, Gln, Thr and Cys, showed no apparent difference, suggesting that conversion of certain amino acids produced by proteolysis occurred. Moreover, the concentration of γ-aminobutyric acid (GABA) in HP-treated sample was higher than that in untreated control. These results suggested that HP treatment induced alteration of distribution of free amino acids of rice grains via proteolysis and certain amino acids metabolism pathways.

  13. Effects of high hydrostatic pressure on distribution dynamics of free amino acids in water soaked brown rice grain

    Shigematsu, T; Nakajima, K; Uno, Y; Sakano, A; Murakami, M; Narahara, Y; Fujii, T; Hayashi, M; Ueno, S

    2010-01-01

    High hydrostatic pressure (HP) with approximately below 400 MPa can induce a transformation of food materials to an alternative form, where membrane systems are damaged but certain enzymes are still active. HP treatment of water soaked brown rice grain could modify the mass transfer inside and apparent activities of enzymes, resulting in HP-dependent change of distribution of free amino acids. Thus, the distribution of free amino acids in brown rice grain during preservation after HP treatment was analyzed. Just after HP treatment at 200 MPa for 10 min, the distribution of free amino acids was not apparently different from that of untreated control. In contrast, after 1 to 4 days preservation at 25 0 C, amino acids, such as Ala, Glu, Gly, Asp and Val, showed higher concentrations than those in control. This result suggested that HP treatment induced proteolysis to produce free amino acids. However, Gln, Thr and Cys, showed no apparent difference, suggesting that conversion of certain amino acids produced by proteolysis occurred. Moreover, the concentration of γ-aminobutyric acid (GABA) in HP-treated sample was higher than that in untreated control. These results suggested that HP treatment induced alteration of distribution of free amino acids of rice grains via proteolysis and certain amino acids metabolism pathways.

  14. Abnormal grain growth: a non-equilibrium thermodynamic model for multi-grain binary systems

    Svoboda, Jiří; Fischer, F. D.

    2014-01-01

    Roč. 22, č. 1 (2014), Art . No. 015013 ISSN 0965-0393 Institutional support: RVO:68081723 Keywords : grain boundary segregation * abnormal grain growth * theory * modelling * solute drag Subject RIV: BJ - Thermodynamics Impact factor: 2.167, year: 2014

  15. The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

    Thomsen, Kristina J.; Murray, Andrew; Jain, Mayank

    2012-01-01

    The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution. This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally, it is an implicit assumption in such analysis that any over-dispersion is not significantly dose dependent. In this study we have undertaken laboratory investigations of the dose dependency of over-dispersion using a well-bleached modern sample with an average measured dose of 36 ± 3 mGy. This sample was prepared as heated (750 °C for 1 h), bleached and untreated portions which were then given uniform gamma doses ranging from 100 mGy to 208 Gy. We show that for these samples the relative laboratory over-dispersion is not constant as a function of dose and that the over-dispersion is smaller in heated samples. We also show that the dim grains in the distributions have a greater over-dispersion than the bright grains, implying that insensitive samples will have greater values of over-dispersion than sensitive samples.

  16. Optimizing electrical distribution systems

    Scott, W.G.

    1990-01-01

    Electrical utility distribution systems are in the middle of an unprecedented technological revolution in planning, design, maintenance and operation. The prime movers of the revolution are the major economic shifts that affect decision making. The major economic influence on the revolution is the cost of losses (technical and nontechnical). The vehicle of the revolution is the computer, which enables decision makers to examine alternatives in greater depth and detail than their predecessors could. The more important elements of the technological revolution are: system planning, computers, load forecasting, analytical systems (primary systems, transformers and secondary systems), system losses and coming technology. The paper is directed towards the rather unique problems encountered by engineers of utilities in developing countries - problems that are being solved through high technology, such as the recent World Bank-financed engineering computer system for Sri Lanka. This system includes a DEC computer, digitizer, plotter and engineering software to model the distribution system via a digitizer, analyse the system and plot single-line diagrams. (author). 1 ref., 4 tabs., 6 figs

  17. The spatial distribution of microfabric around gravel grains: indicator of till formation processes

    KalväNs, Andis; Saks, Tomas

    2010-05-01

    Till micromorphology studies in thin sections is an established tool in the field of glacial geology. Often the thin sections are inspected only visually with help of mineralogical microscope. This can lead to subjective interpretation of observed structures. More objective method used in till micromorphology is measurement of apparent microfabric, usually seen as preferred orientation of elongated sand grains. In theses studies only small fraction of elongated sand grains often confined to small area of thin section usually are measured. We present a method for automated measurement of almost all elongated sand grains across the full area of the thin section. Apparently elongated sand grains are measured using simple image analysis tools, the data are processed in a way similar to regular till fabric data and visualised as a grid of rose diagrams. The method allows to draw statistical information about spatial variation of microfabric preferred orientation and fabric strength with resolution as fine as 1 mm. Late Weichselian tills from several sites in Western Latvia were studied and large variations in fabric strength and spatial distribution were observed in macroscopically similar till units. The observed types of microfabric spatial distributions include strong, monomodal and uniform distribution; weak and highly variable in small distances distribution; consistently bimodal distribution and domain-like pattern of preferred sand grain orientation. We suggest that the method can be readily used to identify the basic deformation and sedimentation processes active during the final stages of till formation. It is understood that the microfabric orientation will be significant affected by nearby large particles. The till is highly heterogonous sediment and the source of microfabric perturbations observed in thin section might lie outside the section plane. Therefore we suggest that microfabric distribution around visible sources of perturbation - gravel grains cut

  18. Distributed Systems 3/e

    Tanenbaum, A.S.; van Steen, M.R.

    2016-01-01

    For this third edition of "Distributed Systems," the material has been thoroughly revised and extended, integrating principles and paradigms into nine chapters: 1. Introduction 2. Architectures 3. Processes 4. Communication 5. Naming 6. Coordination 7. Replication 8. Fault tolerance 9. Security A

  19. Anisotropy model for modern grain oriented electrical steel based on orientation distribution function

    Fan Jiang

    2018-05-01

    Full Text Available Accurately modeling the anisotropic behavior of electrical steel is mandatory in order to perform good end simulations. Several approaches can be found in the literature for that purpose but the more often those methods are not able to deal with grain oriented electrical steel. In this paper, a method based on orientation distribution function is applied to modern grain oriented laminations. In particular, two solutions are proposed in order to increase the results accuracy. The first one consists in increasing the decomposition number of the cosine series on which the method is based. The second one consists in modifying the determination method of the terms belonging to this cosine series.

  20. Improvement of corrosion resistance in austenitic stainless steel by grain boundary character distribution control

    Wang, Yun; Kaneda, Junya; Kasahara, Shigeki; Shigenaka, Naoto

    2012-01-01

    Strauss test, Coriou test and Huey test were conducted on a Type 316L austenitic stainless steel. Improvement in grain boundary corrosion resistance was verified after raising low Σ coincidence site lattice (CSL) grain boundary (GB) frequency by controlling grain boundary character distribution (GBCD). During crevice corrosion test under gamma-ray irradiation, initiation frequency of GB corrosion after GBCD controlled specimens decreased to 1/10 of GBCD uncontrolled counterpart along with lower depth of corrosion. Stress corrosion cracking (SCC) propagation rate of GBCD controlled specimen decreased to less than 1/2 of GBCD uncontrolled specimen in high temperature and high pressure water. Based on these results, we expect that GBCD control will improve corrosion resistance of austenitic material in a wide range of application and environment. (author)

  1. Distributed Optimization System

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2004-11-30

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  2. Fine Structure of Tibetan Kefir Grains and Their Yeast Distribution, Diversity, and Shift

    Lu, Man; Wang, Xingxing; Sun, Guowei; Qin, Bing; Xiao, Jinzhou; Yan, Shuling; Pan, Yingjie; Wang, Yongjie

    2014-01-01

    Tibetan kefir grains (TKGs), a kind of natural starter for fermented milk in Tibet, China, host various microorganisms of lactic acid bacteria, yeasts, and occasionally acetic acid bacteria in a polysaccharide/protein matrix. In the present study, the fine structure of TKGs was studied to shed light on this unusual symbiosis with stereomicroscopy and thin sections. The results reveal that TKGs consist of numerous small grain units, which are characterized by a hollow globular structure with a diameter between 2.0 and 9.0 mm and a wall thickness of approximately 200 µm. A polyhedron-like net structure, formed mainly by the bacteria, was observed in the wall of the grain units, which has not been reported previously to our knowledge. Towards the inside of the grain unit, the polyhedron-like net structures became gradually larger in diameter and fewer in number. Such fine structures may play a crucial role in the stability of the grains. Subsequently, the distribution, diversity, and shift of yeasts in TKGs were investigated based on thin section, scanning electron microscopy, cloning and sequencing of D1/D2 of the 26S rRNA gene, real-time quantitative PCR, and in situ hybridization with specific fluorescence-labeled oligonucleotide probes. These show that (i) yeasts appear to localize on the outer surface of the grains and grow normally together to form colonies embedded in the bacterial community; (ii) the diversity of yeasts is relatively low on genus level with three dominant species – Saccharomyces cerevisiae, Kluyveromyces marxianus, and Yarrowia lipolytica; (iii) S. cerevisiae is the stable predominant yeast species, while the composition of Kluyveromyces and Yarrowia are subject to change over time. Our results indicate that TKGs are relatively stable in structure, and culture conditions to some extent shape the microbial community and interaction in kefir grains. These findings pave the way for further study of the specific symbiotic associations between S

  3. Fine structure of Tibetan kefir grains and their yeast distribution, diversity, and shift.

    Man Lu

    Full Text Available Tibetan kefir grains (TKGs, a kind of natural starter for fermented milk in Tibet, China, host various microorganisms of lactic acid bacteria, yeasts, and occasionally acetic acid bacteria in a polysaccharide/protein matrix. In the present study, the fine structure of TKGs was studied to shed light on this unusual symbiosis with stereomicroscopy and thin sections. The results reveal that TKGs consist of numerous small grain units, which are characterized by a hollow globular structure with a diameter between 2.0 and 9.0 mm and a wall thickness of approximately 200 µm. A polyhedron-like net structure, formed mainly by the bacteria, was observed in the wall of the grain units, which has not been reported previously to our knowledge. Towards the inside of the grain unit, the polyhedron-like net structures became gradually larger in diameter and fewer in number. Such fine structures may play a crucial role in the stability of the grains. Subsequently, the distribution, diversity, and shift of yeasts in TKGs were investigated based on thin section, scanning electron microscopy, cloning and sequencing of D1/D2 of the 26S rRNA gene, real-time quantitative PCR, and in situ hybridization with specific fluorescence-labeled oligonucleotide probes. These show that (i yeasts appear to localize on the outer surface of the grains and grow normally together to form colonies embedded in the bacterial community; (ii the diversity of yeasts is relatively low on genus level with three dominant species--Saccharomyces cerevisiae, Kluyveromyces marxianus, and Yarrowia lipolytica; (iii S. cerevisiae is the stable predominant yeast species, while the composition of Kluyveromyces and Yarrowia are subject to change over time. Our results indicate that TKGs are relatively stable in structure, and culture conditions to some extent shape the microbial community and interaction in kefir grains. These findings pave the way for further study of the specific symbiotic

  4. Superplasticity and grain boundary character distribution in overaged Al-Li-Cu-Mg-Zr alloy

    Avramovic-Cingara, G.; Aust, K.T.; Perovic, D.D.; McQueen, H.J.

    1995-01-01

    Samples of 8091 alloy were subjected to a thermomechanical processing (TMP) treatment that included the following stages: overaging before deformation, multistage deformation at 300 deg C and strain rate change tests for superplasticity. Torsional deformation was utilized both to develop the refined microstructure and to test for superplasticity. The strain rate sensitivity, m, of the material ranged between 0.30 and 0.45 at 450 deg C for strain rates between 8 x 10 -2 and 10 -3 s -1 . The grain boundary character distribution (GBCD) of thermomechanically processed Al-Li-Cu-Mg-Zr (8091) alloy, which develops good superplastic response, has been determined by an electron backscattering diffraction technique (EBSD). All grain boundaries have been classified into one of three categories in terms of Σ values : low angle, coincidence site lattice and random high angle boundaries. Quantitative studies of grain boundary character were done after various processing stages to obtain evidence about structure evolution and indicate an increase in Σ boundary frequency following TMP. Selected area electron diffraction examination (SAD) gave evidence about the refined structure, in which the grain boundary misorientation increased EBSD how the grain boundary character was changed to high Σ values. TEM analyses indicate that the T 2 phase is responsible for substructure stabilization. There is no evidence of cavity formation during superplastic deformation by torsion, which suggests that cavity nucleation is strongly influenced by the nature of stress. (author). 32 refs., 3 tabs., 9 figs

  5. Distributed Data Management and Distributed File Systems

    Girone, Maria

    2015-01-01

    The LHC program has been successful in part due to the globally distributed computing resources used for collecting, serving, processing, and analyzing the large LHC datasets. The introduction of distributed computing early in the LHC program spawned the development of new technologies and techniques to synchronize information and data between physically separated computing centers. Two of the most challenges services are the distributed file systems and the distributed data management systems. In this paper I will discuss how we have evolved from local site services to more globally independent services in the areas of distributed file systems and data management and how these capabilities may continue to evolve into the future. I will address the design choices, the motivations, and the future evolution of the computing systems used for High Energy Physics.

  6. Effect of grain alignment distribution on magnetic properties in (MM, Nd)-Fe-B sintered magnets

    Yu, Xiaoqiang; Yue, Ming; Zhu, Minggang; Liu, Weiqiang; Li, Yuqing; Xi, Longlong; Li, Jiajie; Zhang, Jiuxing; Li, Wei

    2018-03-01

    H cj of (MM x Nd1-x )-Fe-B sintered magnets decreases distinctly with x increasing when misch metal (MM) content (x) ranges from 0.3 to 1. Practical application is taken into consideration so that the (MM0.6Nd0.4)-Fe-B components are chosen to analyze the changes in behavior of the magnetic properties. Both Magnet II and Magnet III belong to (MM0.6Nd0.4)-Fe-B sintered magnets, however, it should be noted that Magnet II is prepared by the single alloying method (SAM) and Magnet III is prepared by the double main phase alloy method (DMPAM). Core-shell structures of the magnets prepared by DMPAM can result in the higher H cj and lower knee-point coercivity (H k) compared with that by SAM. Furthermore, for Magnet II, the abnormal grain growth contributes to a better grain alignment and smaller distribution coefficient (σ) defined as the degree of grain alignment, which will enforce a higher tendency of the H cj decreasing and H k increasing. The expression of their normalized coercivity h(σ) is deduced by combining Gao’s starting field model with Kronmüller’s nucleation mechanism. Based on the overall h(σ) ~ σ curve, the best desirable h(σ) value is calculated when σ  =  0.09. Theoretically, for Magnet III, the resultant larger σ should be attributed to the more uniform grain alignment. In addition, the deviations of grain size distributions on the c-plane become more remarkable with more MM concentrates, which can be presented by SEM images. Meanwhile, by means of the pole figures, it is also verified that the grain alignment distribution becomes much more diverse with x increasing. Therefore, it can be predicted whether the grain alignment distribution is significant for H k and H cj of (MM x Nd1-x )-Fe-B sintered magnets (x  ≠  0.6) prepared by SAM/DMPAM or not.

  7. Secondary recrystallization in non-sag W filament wires -- On the possible role of relative grain boundary character distribution

    Samajdar, I.; Watte, P.; Mertens, F.

    1999-01-01

    Non-Sag tungsten (W) wire is indispensable for the lighting industry. For the necessary creep resistance, large elongated grains are considered as the desired microstructure. These large grains are obtained by primary and secondary recrystallization. In the present study an effort has been made to characterize and to understand the origin of such large elongated grains. In secondary recrystallization, often called abnormal grain growth, a few of the grains grow massive. The mechanisms of normal and abnormal grain growth are essentially the same, involving high angle boundary migration and driven by the reduction of surface energy. The abnormal grain growth can be visualized as a growth advantage for a few of the grains or growth disadvantage for the majority. Such an advantage/disadvantage may be caused by (1) differences in grain size and/or (2) differences in grain boundary character distribution (GBCD). In other words, a grain may grow massive if it has large size and/or possibilities of more favorable (i.e., of higher mobility) grain boundaries with the matrix grains

  8. Elaboration of austenitic stainless steel samples with bimodal grain size distributions and investigation of their mechanical behavior

    Flipon, B.; de la Cruz, L. Garcia; Hug, E.; Keller, C.; Barbe, F.

    2017-10-01

    Samples of 316L austenitic stainless steel with bimodal grain size distributions are elaborated using two distinct routes. The first one is based on powder metallurgy using spark plasma sintering of two powders with different particle sizes. The second route applies the reverse-annealing method: it consists in inducing martensitic phase transformation by plastic strain and further annealing in order to obtain two austenitic grain populations with different sizes. Microstructural analy ses reveal that both methods are suitable to generate significative grain size contrast and to control this contrast according to the elaboration conditions. Mechanical properties under tension are then characterized for different grain size distributions. Crystal plasticity finite element modelling is further applied in a configuration of bimodal distribution to analyse the role played by coarse grains within a matrix of fine grains, considering not only their volume fraction but also their spatial arrangement.

  9. A visual basic program to generate sediment grain-size statistics and to extrapolate particle distributions

    Poppe, L.J.; Eliason, A.H.; Hastings, M.E.

    2004-01-01

    Measures that describe and summarize sediment grain-size distributions are important to geologists because of the large amount of information contained in textural data sets. Statistical methods are usually employed to simplify the necessary comparisons among samples and quantify the observed differences. The two statistical methods most commonly used by sedimentologists to describe particle distributions are mathematical moments (Krumbein and Pettijohn, 1938) and inclusive graphics (Folk, 1974). The choice of which of these statistical measures to use is typically governed by the amount of data available (Royse, 1970). If the entire distribution is known, the method of moments may be used; if the next to last accumulated percent is greater than 95, inclusive graphics statistics can be generated. Unfortunately, earlier programs designed to describe sediment grain-size distributions statistically do not run in a Windows environment, do not allow extrapolation of the distribution's tails, or do not generate both moment and graphic statistics (Kane and Hubert, 1963; Collias et al., 1963; Schlee and Webster, 1967; Poppe et al., 2000)1.Owing to analytical limitations, electro-resistance multichannel particle-size analyzers, such as Coulter Counters, commonly truncate the tails of the fine-fraction part of grain-size distributions. These devices do not detect fine clay in the 0.6–0.1 μm range (part of the 11-phi and all of the 12-phi and 13-phi fractions). Although size analyses performed down to 0.6 μm microns are adequate for most freshwater and near shore marine sediments, samples from many deeper water marine environments (e.g. rise and abyssal plain) may contain significant material in the fine clay fraction, and these analyses benefit from extrapolation.The program (GSSTAT) described herein generates statistics to characterize sediment grain-size distributions and can extrapolate the fine-grained end of the particle distribution. It is written in Microsoft

  10. Distributed System Design Checklist

    Hall, Brendan; Driscoll, Kevin

    2014-01-01

    This report describes a design checklist targeted to fault-tolerant distributed electronic systems. Many of the questions and discussions in this checklist may be generally applicable to the development of any safety-critical system. However, the primary focus of this report covers the issues relating to distributed electronic system design. The questions that comprise this design checklist were created with the intent to stimulate system designers' thought processes in a way that hopefully helps them to establish a broader perspective from which they can assess the system's dependability and fault-tolerance mechanisms. While best effort was expended to make this checklist as comprehensive as possible, it is not (and cannot be) complete. Instead, we expect that this list of questions and the associated rationale for the questions will continue to evolve as lessons are learned and further knowledge is established. In this regard, it is our intent to post the questions of this checklist on a suitable public web-forum, such as the NASA DASHLink AFCS repository. From there, we hope that it can be updated, extended, and maintained after our initial research has been completed.

  11. Parametrizing coarse grained models for molecular systems at equilibrium

    Kalligiannaki, Evangelia; Chazirakis, A.; Tsourtis, A.; Katsoulakis, M. A.; Plechá č, P.; Harmandaris, V.

    2016-01-01

    Hierarchical coarse graining of atomistic molecular systems at equilibrium has been an intensive research topic over the last few decades. In this work we (a) review theoretical and numerical aspects of different parametrization methods (structural-based, force matching and relative entropy) to derive the effective interaction potential between coarse-grained particles. All methods approximate the many body potential of mean force; resulting, however, in different optimization problems. (b) We also use a reformulation of the force matching method by introducing a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (E. Kalligiannaki, et al., J. Chem. Phys. 2015). We apply and compare these methods to: (a) a benchmark system of two isolated methane molecules; (b) methane liquid; (c) water; and (d) an alkane fluid. Differences between the effective interactions, derived from the various methods, are found that depend on the actual system under study. The results further reveal the relation of the various methods and the sensitivities that may arise in the implementation of numerical methods used in each case.

  12. Parametrizing coarse grained models for molecular systems at equilibrium

    Kalligiannaki, Evangelia

    2016-10-18

    Hierarchical coarse graining of atomistic molecular systems at equilibrium has been an intensive research topic over the last few decades. In this work we (a) review theoretical and numerical aspects of different parametrization methods (structural-based, force matching and relative entropy) to derive the effective interaction potential between coarse-grained particles. All methods approximate the many body potential of mean force; resulting, however, in different optimization problems. (b) We also use a reformulation of the force matching method by introducing a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (E. Kalligiannaki, et al., J. Chem. Phys. 2015). We apply and compare these methods to: (a) a benchmark system of two isolated methane molecules; (b) methane liquid; (c) water; and (d) an alkane fluid. Differences between the effective interactions, derived from the various methods, are found that depend on the actual system under study. The results further reveal the relation of the various methods and the sensitivities that may arise in the implementation of numerical methods used in each case.

  13. The grain-size distribution of pyroclasts: Primary fragmentation, conduit sorting or abrasion?

    Kueppers, U.; Schauroth, J.; Taddeucci, J.

    2013-12-01

    Explosive volcanic eruptions expel a mixture of pyroclasts and lithics. Pyroclasts, fragments of the juvenile magma, record the state of the magma at fragmentation in terms of porosity and crystallinity. The grain size distribution of pyroclasts is generally considered to be a direct consequence of the conditions at magma fragmentation that is mainly driven by gas overpressure in bubbles, high shear rates, contact with external water or a combination of these factors. Stress exerted by any of these processes will lead to brittle fragmentation by overcoming the magma's relaxation timescale. As a consequence, most pyroclasts exhibit angular shapes. Upon magma fragmentation, the gas pyroclast mixture is accelerated upwards and eventually ejected from the vent. The total grain size distribution deposited is a function of fragmentation conditions and transport related sorting. Porous pyroclasts are very susceptible to abrasion by particle-particle or particle-conduit wall interaction. Accordingly, pyroclastic fall deposits with angular clasts should proof a low particle abrasion upon contact to other surfaces. In an attempt to constrain the degree of particle interaction during conduit flow, monomodal batches of washed pyroclasts have been accelerated upwards by rapid decompression and subsequently investigated for their grain size distribution. In our set-up, we used a vertical cylindrical tube without surface roughness as conduit. We varied grain size (0.125-0.25; 0.5-1; 1-2 mm), porosity (0; 10; 30 %), gas-particle ratio (10 and 40%), conduit length (10 and 28 cm) and conduit diameter (2.5 and 6 cm). All ejected particles were collected after settling at the base of a 3.3 m high tank and sieved at one sieve size below starting size (half-Φ). Grain size reduction showed a positive correlation with starting grain size, porosity and overpressure at the vent. Although milling in a volcanic conduit may take place, porous pyroclasts are very likely to be a primary product

  14. Effects of crystallographic orientation vs. grain interaction on slip systems

    Winther, Grethe

    . Such investigations reveal both similarities and differences. The present contribution gives an overview of a series of investigations, including transmission electron microscopy as well as three-dimensional x-ray diffraction on polycrystalline aluminium deformed to strains of 5-50%. The data are analysed focusing...... on the set of activated slip systems, more precisely whether the observed differences can be attributed to fluctuations in the relative activities of the same set of systems or whether activation of truly different systems is the origin of the variations between and within grains....

  15. Electrical distribution system management

    Hajos, L.; Mortarulo, M.; Chang, K.; Sparks, T.

    1990-01-01

    This paper reports that maintenance of electrical system data is essential to the operation, maintenance, and modification of a nuclear station. Load and equipment changes affect equipment sizing, available short-circuit currents and protection coordination. System parameters must be maintained in a controlled manner to enable evaluation of proposed modifications and provide adequate verification and traceability. For this purpose, Public Service Electric and Gas Company has implemented a Verified and Validated Electric Distribution System Management (EDSM) program at the Hope Creek and Salem Nuclear Power Stations. EDSM program integrates computerized configuration management of electrical systems with calculational software the Technical Standard procedures. The software platform is PC-based. The Database Manager and Calculational programs have been linked together through a user friendly menu system. The database management nodule enable s assembly and maintenance of databases for individual loads, buses, and branches within the electrical systems with system access and approval controlled through electronic security incorporated within the database manger. Reports drawn from the database serve as the as-built and/or as-designed record of the system configurations. This module also creates input data files of network parameters in a format readable by the calculational modules. Calculations modules provide load flow, voltage drop, motor starting, and short-circuit analyses, as well as dynamic analyses of bus transfers

  16. Flow Characteristics and Grain Size Distribution of Granular Gangue Mineral by Compaction Treatment

    Ran Yuan

    2017-01-01

    Full Text Available A test system for water flow in granular gangue mineral was designed to study the flow characteristics by compaction treatment. With the increase of the compaction displacement, the porosity decreases and void in granular gangue becomes less. The main reason causing initial porosity decrease is that the void of larger size is filled with small particles. Permeability tends to decrease and non-Darcy flow factor increases under the compaction treatment. The change trend of flow characteristics shows twists and turns, which indicate that flow characteristics of granular gangue mineral are related to compaction level, grain size distribution, crushing, and fracture structure. During compaction, larger particles are crushed, which in turn causes the weight of smaller particles to increase, and water flow induces fine particles to migrate (weight loss; meanwhile, a sample with more weight of size (0–2.5 mm has a higher amount of weight loss. Water seepage will cause the decrease of some chemical components, where SiO2 decreased the highest in these components; the components decreased are more likely locked at fragments rather than the defect of the minerals. The variation of the chemical components has an opposite trend when compared with permeability.

  17. Planning Systems for Distributed Operations

    Maxwell, Theresa G.

    2002-01-01

    This viewgraph representation presents an overview of the mission planning process involving distributed operations (such as the International Space Station (ISS)) and the computer hardware and software systems needed to support such an effort. Topics considered include: evolution of distributed planning systems, ISS distributed planning, the Payload Planning System (PPS), future developments in distributed planning systems, Request Oriented Scheduling Engine (ROSE) and Next Generation distributed planning systems.

  18. Managing Distributed Knowledge Systems

    Sørensen, Brian Vejrum; Gelbuda, Modestas

    2005-01-01

    . This paper contributes to the research on organizations as distributed knowledge systems by addressing two weaknesses of the social practice literature. Firstly, it downplays the importance of formal structure and organizational design and intervention efforts by key organizational members. Secondly, it does......The article argues that the growth of de novo knowledge-based organization depends on managing and coordinating increasingly growing and, therefore, distributed knowledge. Moreover, the growth in knowledge is often accompanied by an increasing organizational complexity, which is a result...... of integrating new people, building new units and adding activities to the existing organization. It is argued that knowledge is not a stable capacity that belongs to any actor alone, but that it is rather an ongoing social accomplishment, which is created and recreated as actors engage in mutual activities...

  19. Micro-PIXE mapping of mineral distribution in mature grain of two pearl millet cultivars

    Minnis-Ndimba, R., E-mail: rminnis@tlabs.ac.za [iThemba LABS, National Research Foundation (South Africa); Kruger, J.; Taylor, J.R.N. [Department of Food Science and Institute for Food, Nutrition and Well-being, University of Pretoria (South Africa); Mtshali, C. [iThemba LABS, National Research Foundation (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation (South Africa); Faculty of Health and Wellness Sciences, CPUT, Bellville (South Africa)

    2015-11-15

    Micro-proton-induced X-ray emission (micro-PIXE) was used to map the distribution of several nutritionally important minerals found in the grain tissue of two cultivars of pearl millet (Pennisetum glaucum (L.) R. Br.). The distribution maps revealed that the predominant localisation of minerals was within the germ (consisting of the scutellum and embryo) and the outer grain layers (specifically the pericarp and aleurone); whilst the bulk of the endosperm tissue featured relatively low concentrations of the surveyed minerals. Within the germ, the scutellum was revealed as a major storage tissue for P and K, whilst Ca, Mn and Zn were more prominent within the embryo. Fe was revealed to have a distinctive distribution pattern, confined to the dorsal end of the scutellum; but was also highly concentrated in the outer grain layers. Interestingly, the hilar region was also revealed as a site of high accumulation of minerals, particularly for S, Ca, Mn, Fe and Zn, which may be part of a defensive strategy against infection or damage. Differences between the two cultivars, in terms of the bulk Fe and P content obtained via inductively coupled plasma optical emission spectrometry (ICP-OES), concurred with the average concentration data determined from the analysis of micro-PIXE spectra specifically extracted from the endosperm tissue.

  20. Influence of grain size distribution on dynamic shear modulus of sands

    Dyka Ireneusz

    2017-11-01

    Full Text Available The paper presents the results of laboratory tests, that verify the correlation between the grain-size characteristics of non-cohesive soils and the value of the dynamic shear modulus. The problem is a continuation of the research performed at the Institute of Soil Mechanics and Rock Mechanics in Karlsruhe, by T. Wichtmann and T. Triantafyllidis, who derived the extension of the applicability of the Hardin’s equation describing the explicite dependence between the grain size distribution of sands and the values of dynamic shear modulus. For this purpose, piezo-ceramic bender elements generating elastic waves were used to investigate the mechanical properties of the specimens with artificially generated particle distribution. The obtained results confirmed the hypothesis that grain size distribution of non-cohesive soils has a significant influence on the dynamic shear modulus, but at the same time they have shown that obtaining unambiguous results from bender element tests is a difficult task in practical applications.

  1. Distributed road assessment system

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

    A system that detects damage on or below the surface of a paved structure or pavement is provided. A distributed road assessment system includes road assessment pods and a road assessment server. Each road assessment pod includes a ground-penetrating radar antenna array and a detection system that detects road damage from the return signals as the vehicle on which the pod is mounted travels down a road. Each road assessment pod transmits to the road assessment server occurrence information describing each occurrence of road damage that is newly detected on a current scan of a road. The road assessment server maintains a road damage database of occurrence information describing the previously detected occurrences of road damage. After the road assessment server receives occurrence information for newly detected occurrences of road damage for a portion of a road, the road assessment server determines which newly detected occurrences correspond to which previously detected occurrences of road damage.

  2. Communication Facilities for Distributed Systems

    V. Barladeanu

    1997-01-01

    Full Text Available The design of physical networks and communication protocols in Distributed Systems can have a direct impact on system efficiency and reliability. This paper tries to identify efficient mechanisms and paradigms for communication in distributed systems.

  3. Optimizing queries in distributed systems

    Ion LUNGU

    2006-01-01

    Full Text Available This research presents the main elements of query optimizations in distributed systems. First, data architecture according with system level architecture in a distributed environment is presented. Then the architecture of a distributed database management system (DDBMS is described on conceptual level followed by the presentation of the distributed query execution steps on these information systems. The research ends with presentation of some aspects of distributed database query optimization and strategies used for that.

  4. Determination of hydraulic conductivity from grain-size distribution for different depositional environments

    Rosas, Jorge

    2013-06-06

    Over 400 unlithified sediment samples were collected from four different depositional environments in global locations and the grain-size distribution, porosity, and hydraulic conductivity were measured using standard methods. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations (e.g., Hazen, Carman-Kozeny) commonly used to estimate hydraulic conductivity from grain-size distribution. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values with errors ranging to over 500%. To improve the empirical estimation methodology, the samples were grouped by depositional environment and subdivided into subgroups based on lithology and mud percentage. The empirical methods were then analyzed to assess which methods best estimated the measured values. Modifications of the empirical equations, including changes to special coefficients and addition of offsets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, offshore marine, and river sediments. Estimated hydraulic conductivity errors were reduced to 6 to 7.1m/day for the beach subgroups, 3.4 to 7.1m/day for dune subgroups, and 2.2 to 11m/day for offshore sediments subgroups. Improvements were made for river environments, but still produced high errors between 13 and 23m/day. © 2013, National Ground Water Association.

  5. Determination of hydraulic conductivity from grain-size distribution for different depositional environments

    Rosas, Jorge; Lopez Valencia, Oliver Miguel; Missimer, Thomas M.; Coulibaly, Kapo M.; Dehwah, Abdullah; Sesler, Kathryn; Rodri­ guez, Luis R. Lujan; Mantilla, David

    2013-01-01

    Over 400 unlithified sediment samples were collected from four different depositional environments in global locations and the grain-size distribution, porosity, and hydraulic conductivity were measured using standard methods. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations (e.g., Hazen, Carman-Kozeny) commonly used to estimate hydraulic conductivity from grain-size distribution. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values with errors ranging to over 500%. To improve the empirical estimation methodology, the samples were grouped by depositional environment and subdivided into subgroups based on lithology and mud percentage. The empirical methods were then analyzed to assess which methods best estimated the measured values. Modifications of the empirical equations, including changes to special coefficients and addition of offsets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, offshore marine, and river sediments. Estimated hydraulic conductivity errors were reduced to 6 to 7.1m/day for the beach subgroups, 3.4 to 7.1m/day for dune subgroups, and 2.2 to 11m/day for offshore sediments subgroups. Improvements were made for river environments, but still produced high errors between 13 and 23m/day. © 2013, National Ground Water Association.

  6. Quality monitored distributed voting system

    Skogmo, David

    1997-01-01

    A quality monitoring system can detect certain system faults and fraud attempts in a distributed voting system. The system uses decoy voters to cast predetermined check ballots. Absent check ballots can indicate system faults. Altered check ballots can indicate attempts at counterfeiting votes. The system can also cast check ballots at predetermined times to provide another check on the distributed voting system.

  7. Distribution of garnet grain sizes and morphologies across the Moine Supergroup, northern Scottish Caledonides

    Ashley, Kyle T.; Thigpen, J. Ryan; Law, Richard D.

    2016-04-01

    Garnet is used in a wide range of geologic studies due to its important physical and chemical characteristics. While the mineral is useful for thermobarometry and geochronology constraints and can often be correlated to deformation and fabric development, difficulties remain in making meaningful interpretations of such data. In this study, we characterize garnet grain sizes and crystal morphologies from 141 garnet-bearing metasedimentary rock samples collected from the northern part of the Moine Supergroup in the Scottish Caledonides. Larger, euhedral crystals are indicative of prograde metamorphic growth and are typically associated with the most recent phase of orogenesis (Scandian, ˜430 Ma). Small, rounded ("pin-head") garnets are interpreted as detrital in origin. A subhedral classification is more subjective and is used when garnets contains portions of straight boundaries but have rounded edges or rims that have been altered through retrograde metamorphic reactions. From our collection, 88 samples contain anhedral garnets (maximum measured grain size d = 0.46 ± 0.21 mm), 34 bear subhedral garnets (d = 2.0 ± 1.0 mm), and the remaining 19 samples contain garnets with euhedral grains (d = 4.4 ± 2.6 mm). Plotting the distribution of garnets relative to the mapped thrust contacts reveals an abrupt change in morphology and grain size when traced from the Moine thrust sheet across the Ben Hope and Sgurr Beag thrusts into the higher-grade, more hinterland-positioned thrust sheets. The dominance of anhedral garnets in the Moine thrust sheet suggests that these grains should not be used for peak P - T estimation associated with relatively low temperature (advance of interpreting large suits of garnet-derived thermodynamic and geochronologic data.

  8. Quantitative analysis of crystal/grain sizes and their distributions in 2D and 3D

    Berger, Alfons; Herwegh, Marco; Schwarz, Jens-Oliver

    2011-01-01

    data for grain size data are either 1D (i.e. line intercept methods), 2D (area analysis) or 3D (e.g., computed tomography, serial sectioning). These data have been used for different data treatments over the years, whereas several studies assume a certain probability function (e.g., logarithm, square......-piezometers or grain size sensitive flow laws. Such compatibility is tested for different data treatments using one- and two-dimensional measurements. We propose an empirical conversion matrix for different datasets. These conversion factors provide the option to make different datasets compatible with each other...... is important for studies of nucleation and growth of minerals. The shape of the crystal size distribution of garnet populations is compared between different 2D and 3D measurements, which are serial sectioning and computed tomography. The comparison of different direct measured 3D data; stereological data...

  9. Process evaluation distributed system

    Moffatt, Christopher L. (Inventor)

    2006-01-01

    The distributed system includes a database server, an administration module, a process evaluation module, and a data display module. The administration module is in communication with the database server for providing observation criteria information to the database server. The process evaluation module is in communication with the database server for obtaining the observation criteria information from the database server and collecting process data based on the observation criteria information. The process evaluation module utilizes a personal digital assistant (PDA). A data display module in communication with the database server, including a website for viewing collected process data in a desired metrics form, the data display module also for providing desired editing and modification of the collected process data. The connectivity established by the database server to the administration module, the process evaluation module, and the data display module, minimizes the requirement for manual input of the collected process data.

  10. Path-space variational inference for non-equilibrium coarse-grained systems

    Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plecháč, Petr

    2016-01-01

    In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.

  11. Path-space variational inference for non-equilibrium coarse-grained systems

    Harmandaris, Vagelis, E-mail: harman@uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete (Greece); Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), IACM/FORTH, GR-71110 Heraklion (Greece); Kalligiannaki, Evangelia, E-mail: ekalligian@tem.uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete (Greece); Katsoulakis, Markos, E-mail: markos@math.umass.edu [Department of Mathematics and Statistics, University of Massachusetts at Amherst (United States); Plecháč, Petr, E-mail: plechac@math.udel.edu [Department of Mathematical Sciences, University of Delaware, Newark, Delaware (United States)

    2016-06-01

    In this paper we discuss information-theoretic tools for obtaining optimized coarse-grained molecular models for both equilibrium and non-equilibrium molecular simulations. The latter are ubiquitous in physicochemical and biological applications, where they are typically associated with coupling mechanisms, multi-physics and/or boundary conditions. In general the non-equilibrium steady states are not known explicitly as they do not necessarily have a Gibbs structure. The presented approach can compare microscopic behavior of molecular systems to parametric and non-parametric coarse-grained models using the relative entropy between distributions on the path space and setting up a corresponding path-space variational inference problem. The methods can become entirely data-driven when the microscopic dynamics are replaced with corresponding correlated data in the form of time series. Furthermore, we present connections and generalizations of force matching methods in coarse-graining with path-space information methods. We demonstrate the enhanced transferability of information-based parameterizations to different observables, at a specific thermodynamic point, due to information inequalities. We discuss methodological connections between information-based coarse-graining of molecular systems and variational inference methods primarily developed in the machine learning community. However, we note that the work presented here addresses variational inference for correlated time series due to the focus on dynamics. The applicability of the proposed methods is demonstrated on high-dimensional stochastic processes given by overdamped and driven Langevin dynamics of interacting particles.

  12. Distributed security in closed distributed systems

    Hernandez, Alejandro Mario

    properties. This is also restricted to distributed systems in which the set of locations is known a priori. All this follows techniques borrowed from both the model checking and the static analysis communities. In the end, we reach a step towards solving the problem of enforcing security in distributed...... systems. We achieve the goal of showing how this can be done, though we restrict ourselves to closed systems and with a limited set of enforceable security policies. In this setting, our approach proves to be efficient. Finally, we achieve all this by bringing together several fields of Computer Science......The goal of the present thesis is to discuss, argue and conclude about ways to provide security to the information travelling around computer systems consisting of several known locations. When developing software systems, security of the information managed by these plays an important role...

  13. FROM ATOMISTIC TO SYSTEMATIC COARSE-GRAINED MODELS FOR MOLECULAR SYSTEMS

    Harmandaris, Vagelis; Kalligiannaki, Evangelia; Katsoulakis, Markos; Plechac, Petr

    2017-01-01

    The development of systematic (rigorous) coarse-grained mesoscopic models for complex molecular systems is an intense research area. Here we first give an overview of methods for obtaining optimal parametrized coarse-grained models, starting from

  14. Analysis of Grain Size Distribution and Hydraulic Conductivity for a Variety of Sediment Types with Application to Wadi Sediments

    Rosas Aguilar, Jorge

    2013-01-01

    Grain size distribution, porosity, and hydraulic conductivity from over 400 unlithified sediment samples were analized. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations

  15. Classification system for rain fed wheat grain cultivars using artificial ...

    Artificial neural network (ANN) models have found wide applications, including ... of grains is essential for various applications as wheat grain industry and cultivation. In order to classify the rain fed wheat cultivars using artificial neural network ...

  16. The effect of oxide particles on the strength and ductility of bulk iron with a bimodal grain size distribution

    Casas, C.; Tejedor, R. [Department of Materials Science and Metallurgical Engineering, ETSEIB, Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Rodríguez-baracaldo, R. [Department of Mechanical Engineering, Universidad Nacional de Colombia, Bogotá. Colombia (Colombia); Benito, J.A., E-mail: Josep.a.benito@upc.edu [Department of Materials Science and Metallurgical Engineering, EUETIB, Universitat Politècnica de Catalunya, Comte d' Urgell 187, 08036 Barcelona (Spain); Fundació CTM Centre Tecnològic de Manresa, Plaça de la Ciencia, 2, 08243 Manresa (Spain); Cabrera, J.M. [Department of Materials Science and Metallurgical Engineering, ETSEIB, Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundació CTM Centre Tecnològic de Manresa, Plaça de la Ciencia, 2, 08243 Manresa (Spain)

    2015-03-11

    The strength and ductility of bulk nanostructured and ultrafine-grained iron containing 0.39% oxygen by weight was determined by tensile tests. Samples were obtained by consolidation of milled iron powder at 500 °C. Heat treatments were designed to cover a wide range of grain sizes spanning from 100 to 2000 nm with different percentages of coarse and nanostructured grain areas, which was defined as a bimodal grain size distribution. Transmission electron microscopy was used to determine the diameter, volume fraction and location of oxides in the microstructure. The strength was analysed following two approaches. The first one was based on the strong effect of oxides and involved the use of a mixed particle-grain boundary strengthening model, and the second one was based on simple grain boundary strengthening. The mixed model underestimated the strength of nanostructured samples, whereas the simple grain boundary model worked better. However, for specimens with a bimodal grain size, the fitting of the mixed model was better. In this case, the more effective particle strengthening was related to the dispersion of oxides inside the large ferrite grains. In addition, the bimodal samples showed an acceptable combination of strength and ductility. Again, the ferrite grains containing oxides promoted strain hardening due to the increase in dislocation activity.

  17. Grain size and shape analysis of the AD 1226 tephra layer, Reykjanes volcanic system

    Ösp Magnúsdóttir, Agnes; Höskuldsson, Ármann; Larsen, Guðrún; Tumi Guðmunsson, Magnús; Sigurgeirsson, Magnús Á.

    2014-05-01

    Recent explosive eruptions in Iceland have drawn attention to long range tephra transport in the atmosphere. In Iceland tephra forming explosion eruptions are frequent, due to abundance of water. However, the volcanism on the island is principally basaltic. Volcanism along the Reykjanes Peninsula is divided into five distinct volcanic systems. Volcano-tectonic activity within these systems is periodic, with recurrence intervals in the range of 1 ka. Last volcano-tectonic sequence began around AD 940, shortly after settlement of Iceland, and lasted through AD 1340. During this period activity was characterized by basaltic fissure eruptions. Furthermore, this activity period on the Reykjanes peninsula began within the eastern most volcanic system and gradually moved towards the west across the peninsula. The 1226 eruption was a basaltic fissure eruption with in the Reykjanes volcanic system. The eruption began on land and gradually progressed towards the SW until the volcanic fissure extended into the sea. Water-magma interaction changed the eruption from effusive into explosive forming the largest tephra layer on the peninsula. Due to its close proximity to the Keflavik international airport and that of the capital of Iceland it is important to get an insight into, the characteristics, generation and distribution of such tephra deposits. In this eruption the tephra produced had an approximate volume of 0.1 km3 and covered an area of some 3500 km2 within the 0.5 cm isopach. Total grain size distribution of this tephra layer will be presented along with analysis of principal grain shapes of the finer portion of the tephra layer as a function of distance from the source. The tephra grain size is dominated by particles finer than 1 millimeter with an almost complete absence of large grains independent of distance from the source. Comprehensive understanding of the characteristics of tephra generated in this eruption can help us to understand hazards posed by future

  18. Model for phonon transmission through a NbN grain-size distribution: Comparison with tunneling-spectroscopy observations

    Chicault, R.; Joly, Y.

    1990-01-01

    Transport properties of phonons in granular NbN thin film with left-angle 111 right-angle texture are discussed. We propose a model in which each grain has an acoustic resonance when phonons propagate parallel to the film and where a coupling through the amorphous boundaries exists. A statistical study shows that the most homogeneous chains in the grain stack are selected because of the strong efficiency of their transport properties and that they give a fine structure of phonon modes even if the grain-size distribution is quite large. A reasonable agreement is obtained between our tunneling-spectroscopy experiments and the model. A typical experimental result has been fitted using an inelastic phonon-electron-interaction mean free path Λ ph ∼215 nm and a mean grain size d M ∼25.7 nm, the full width at half maximum of the grain distribution being 14 nm

  19. A revisited Johnson-Mehl-Avrami-Kolmogorov model and the evolution of grain-size distributions in steel

    Hömberg, D.; Patacchini, F. S.; Sakamoto, K.; Zimmer, J.

    2016-01-01

    The classical Johnson-Mehl-Avrami-Kolmogorov approach for nucleation and growth models of diffusive phase transitions is revisited and applied to model the growth of ferrite in multiphase steels. For the prediction of mechanical properties of such steels, a deeper knowledge of the grain structure is essential. To this end, a Fokker-Planck evolution law for the volume distribution of ferrite grains is developed and shown to exhibit a log-normally distributed solution. Numerical parameter studi...

  20. New empirical relationship between grain size distribution and hydraulic conductivity for ephemeral streambed sediments

    Rosas, Jorge

    2014-07-19

    Grain size distribution, porosity, and hydraulic conductivity were determined for 39 sediment samples collected from ephemeral streams (wadis) in western Saudi Arabia. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations commonly used to estimate hydraulic conductivity from grain size analyses. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly with the measured hydraulic conductivity values. Modifications of the empirical equations, including changes to special coefficients and statistical offsets, were made to produce modified equations that considerably improved the hydraulic conductivity estimates from grain size data for wadi sediments. The Chapuis, Hazen, Kozeny, Slichter, Terzaghi, and Barr equations produced the best correlations, but still had relatively high predictive errors. The Chapius equation was modified for wadi sediments by incorporating mud percentage and the standard deviation (in phi units) into a new equation that reduced the predicted hydraulic conductivity error to ±14.1 m/day. The equation is best applied to ephemeral stream samples that have hydraulic conductive values greater than 2 m/day.

  1. Effect of Seed Distribution and Population on Maize (Zea mays L. Grain Yield

    Bee Khim Chim

    2014-01-01

    Full Text Available Maize planting is normally accomplished by hand in the developing world where two or more seeds are placed per hill with a heterogeneous plant spacing and density. To understand the interaction between seed distribution and distance between hills, experiments were established in 2012 and 2013 at Lake Carl Blackwell (LCB and Efaw Agronomy Research Stations, near Stillwater, OK. A randomized complete block design was used with three replications and 9 treatments and a factorial treatment structure of 1, 2, and 3 seeds per hill using interrow spacing of 0.16, 0.32, and 0.48 m. Data for normalized difference vegetation index (NDVI, intercepted photosynthetically active radiation (IPAR, grain yield, and grain N uptake were collected. Results showed that, on average, NDVI and IPAR increased with number of seeds per hill and decreased with increasing plant spacing. In three of four site-years, planting 1 or 2 seeds per hill, 0.16 m apart, increased grain yield and N uptake. Over sites, planting 1 seed, every 0.16 m, increased yields by an average of 1.15 Mg ha−1 (range: 0.33 to 2.46 Mg ha−1 when compared to the farmer practice of placing 2 to 3 seeds per hill, every 0.48 m.

  2. New empirical relationship between grain size distribution and hydraulic conductivity for ephemeral streambed sediments

    Rosas, Jorge; Jadoon, Khan; Missimer, Thomas M.

    2014-01-01

    Grain size distribution, porosity, and hydraulic conductivity were determined for 39 sediment samples collected from ephemeral streams (wadis) in western Saudi Arabia. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations commonly used to estimate hydraulic conductivity from grain size analyses. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly with the measured hydraulic conductivity values. Modifications of the empirical equations, including changes to special coefficients and statistical offsets, were made to produce modified equations that considerably improved the hydraulic conductivity estimates from grain size data for wadi sediments. The Chapuis, Hazen, Kozeny, Slichter, Terzaghi, and Barr equations produced the best correlations, but still had relatively high predictive errors. The Chapius equation was modified for wadi sediments by incorporating mud percentage and the standard deviation (in phi units) into a new equation that reduced the predicted hydraulic conductivity error to ±14.1 m/day. The equation is best applied to ephemeral stream samples that have hydraulic conductive values greater than 2 m/day.

  3. On the grain boundary character distribution of Incoloy 800H during dynamic recrystallization

    Cao, Yu, E-mail: vieri32825@126.com [College of Materials Science and Engineering, Chongqing University, Chongqing 400045 (China); Di, Hongshuang [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Huang, Guangjie [College of Materials Science and Engineering, Chongqing University, Chongqing 400045 (China)

    2017-04-01

    In this paper, we investigated the influence of hot deformation parameters on the distribution and proliferation of twin boundaries during dynamic recrystallization (DRX). The results showed that microstructure evolution is characterized by a process of “dynamic recovery (DRV)→necklace/multiple necklace→fully DRX” with increasing temperature and decreasing strain rate. The predominant proliferation mechanism of Σ3{sup n} (1 ≤ n ≤ 3) boundaries is transformed from Σ3 regeneration to new twinning during the growth of DRX grains.

  4. Study of sandy soil grain-size distribution on its deformation properties

    Antropova, L. B.; Gruzin, A. V.; Gildebrandt, M. I.; Malaya, L. D.; Nikulina, V. B.

    2018-04-01

    As a rule, new oil and gas fields' development faces the challenges of providing construction objects with material and mineral resources, for example, medium sand soil for buildings and facilities footings of the technological infrastructure under construction. This problem solution seems to lie in a rational usage of the existing environmental resources, soils included. The study was made of a medium sand soil grain-size distribution impact on its deformation properties. Based on the performed investigations, a technique for controlling sandy soil deformation properties was developed.

  5. On the grain boundary character distribution of Incoloy 800H during dynamic recrystallization

    Cao, Yu; Di, Hongshuang; Huang, Guangjie

    2017-01-01

    In this paper, we investigated the influence of hot deformation parameters on the distribution and proliferation of twin boundaries during dynamic recrystallization (DRX). The results showed that microstructure evolution is characterized by a process of “dynamic recovery (DRV)→necklace/multiple necklace→fully DRX” with increasing temperature and decreasing strain rate. The predominant proliferation mechanism of Σ3 n (1 ≤ n ≤ 3) boundaries is transformed from Σ3 regeneration to new twinning during the growth of DRX grains.

  6. Distribution System Pricing with Distributed Energy Resources

    Hledik, Ryan [The Brattle Group, Cambridge, MA (United States); Lazar, Jim [The Regulatory Assistance Project, Montpelier, VT (United States); Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-16

    Technological changes in the electric utility industry bring tremendous opportunities and significant challenges. Customers are installing clean sources of on-site generation such as rooftop solar photovoltaic (PV) systems. At the same time, smart appliances and control systems that can communicate with the grid are entering the retail market. Among the opportunities these changes create are a cleaner and more diverse power system, the ability to improve system reliability and system resilience, and the potential for lower total costs. Challenges include integrating these new resources in a way that maintains system reliability, provides an equitable sharing of system costs, and avoids unbalanced impacts on different groups of customers, including those who install distributed energy resources (DERs) and low-income households who may be the least able to afford the transition.

  7. Lead (Pb) Toxicity; Physio-Biochemical Mechanisms, Grain Yield, Quality, and Pb Distribution Proportions in Scented Rice.

    Ashraf, Umair; Kanu, Adam S; Deng, Quanquan; Mo, Zhaowen; Pan, Shenggang; Tian, Hua; Tang, Xiangru

    2017-01-01

    Lead (Pb) caused interruptions with normal plant metabolism, crop yield losses and quality issues are of great concern. This study assessed the physio-biochemical responses, yield and grain quality traits and Pb distribution proportions in three different fragrant rice cultivars i.e., Meixiangzhan-2, Xinagyaxiangzhan and Basmati-385. Plants were exposed to 400, 800, and 1,200 ppm of Pb while pots without Pb were taken as control (0 ppm). Our results showed that Pb toxicity significantly ( P production of hydrogen peroxide (H 2 O 2 ), malanodialdehyde (MDA) and leaves leachates; while such effects were more apparent in Xinagyaxiangzhan than other two rice cultivars. Pb stress differentially affected the production protein, proline and soluble sugars; however the production rates were higher at heading stage (HS) than maturity stage (MS). Furthermore, Pb stress altered superoxide dismutase (SOD), peroxidases (POD), catalases (CAT) and ascorbate peroxidases (APX) activities and glutathione (GSH) and oxidized glutathione (GSSG) production in all rice cultivars at both HS and MS. All Pb levels reduced the yield and yield components of all rice cultivars; nonetheless such reductions were observed highest in Xinagyaxiangzhan (69.12%) than Meixiangzhan-2 (58.05%) and Basmati-385 (46.27%) and resulted in grain quality deterioration. Significant and positive correlations among rice yields with productive tillers/pot and grains per panicle while negative with sterility percentage were also observed. In addition, all rice cultivars readily taken up the Pb contents from soil to roots and transported upward in different proportions with maximum in roots followed by stemss, leaves, ears and grains. Higher proportions of Pb contents in above ground plant parts in Xinagyaxiangzhan possibly lead to maximum losses in this cultivar than other two cultivars; while less damage in Basmati-385 might be related to strong anti-oxidative defense system and lower proportions of Pb contents in

  8. RBAC Administration in Distributed Systems

    Dekker, M.A.C.; Crampton, J.; Etalle, Sandro

    2007-01-01

    Despite a large body of literature on the administration of RBAC policies in centralized systems, the problem of the administration of a distributed system has hardly been addressed. We present a formal system for modelling a distributed RBAC system and its administration. We define two basic

  9. New Technology/Old Technology: Comparing Lunar Grain Size Distribution Data and Methods

    Fruland, R. M.; Cooper, Bonnie L.; Gonzalexz, C. P.; McKay, David S.

    2011-01-01

    Laser diffraction technology generates reproducible grain size distributions and reveals new structures not apparent in old sieve data. The comparison of specific sieve fractions with the Microtrac distribution curve generated for those specific fractions shows a reasonable match for the mean of each fraction between the two techniques, giving us confidence that the large existing body of sieve data can be cross-correlated with new data based on laser diffraction. It is well-suited for lunar soils, which have as much as 25% of the material in the less than 20 micrometer fraction. The fines in this range are of particular interest because they may contain a record of important space weathering processes.

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

    I.V. Pentegov

    2015-12-01

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

  11. Defect distribution in deformed grains of Cu-based alloy polycrystals

    Koneva, N. A.; Trishkina, L. I.; Cherkasova, T. V.

    2017-12-01

    The paper presents transmission electron microscopy data on the grain defect structure formed in deformed Cu-Al polycrystals. The data show that the parameters of dislocation substructures vary with distance from grain boundaries and that a hardened zone arises near the grain boundaries and its size depends on the grain size.

  12. Distribution system modeling and analysis

    Kersting, William H

    2001-01-01

    For decades, distribution engineers did not have the sophisticated tools developed for analyzing transmission systems-often they had only their instincts. Things have changed, and we now have computer programs that allow engineers to simulate, analyze, and optimize distribution systems. Powerful as these programs are, however, without a real understanding of the operating characteristics of a distribution system, engineers using the programs can easily make serious errors in their designs and operating procedures. Distribution System Modeling and Analysis helps prevent those errors. It gives readers a basic understanding of the modeling and operating characteristics of the major components of a distribution system. One by one, the author develops and analyzes each component as a stand-alone element, then puts them all together to analyze a distribution system comprising the various shunt and series devices for power-flow and short-circuit studies. He includes the derivation of all models and includes many num...

  13. Correlation Between Grain Size Distribution and Silicon and Oxygen Contents at Wadi Arar Sediments, Kingdom of Saudi Arabia

    M. A. M. Alghamdi

    2017-08-01

    Full Text Available Quartz is the major mineral of Wadi Arar sediments. The top two elements contents are oxygen with 63.96 wt%, followed by silicon with 16.35 wt%. There is a positive, weak to medium correlation between grain size and silicon and oxygen contents. The correlation between oxygen and grain size is four times higher than that of silicon. At grain size ranges between 0.8 and 1.0 mm, both oxygen and silicon show the maximum correlation, which decrease gradually with finer and coarser grain sizes. For each element, the correlation between the element content and grain size is a fourth degree polynomial in the grain size. Theoretically, the best two math models that represent the relation between the grain size distribution and each of individual oxygen and silicon content are y=8.84∙ln(x+39.5 and y=2.26∙ln(x+10.1 respectively, where y represents the element content percentage and x represents the corresponding grain size in mm.

  14. Grain Size Distribution and Health Risk Assessment of Metals in Outdoor Dust in Chengdu, Southwestern China.

    Chen, Mengqin; Pi, Lu; Luo, Yan; Geng, Meng; Hu, Wenli; Li, Zhi; Su, Shijun; Gan, Zhiwei; Ding, Sanglan

    2016-04-01

    A total of 27 outdoor dust samples from roads, parks, and high spots were collected and analyzed to investigate the contamination of 11 metals (Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, and Pb) in Chengdu, China. The results showed that the samples from the high spots exhibited the highest heavy metal level compared with those from the roads and the parks, except for Ni, Cu, and Pb. The dust was classified into five grain size fractions. The mean loads of each grain size fraction of 11 determined metals displayed similar distribution, and the contribution of median size (63-125, 125-250, 250-500 μm) fractions accounted for more than 70% of overall heavy metal loads. The health risk posed by the determined metals to human via dust ingestion, dermal contact, and inhalation was investigated. Oral and respiratory bioaccessible parts of the metals in dust were extracted using simulated stomach solution and composite lung serum. The mean bioaccessibilities of 11 investigated metals in the gastric solution were much higher than those in the composite lung serum, especially Zn, Cd, and Pb. Ingestion was the most important exposure pathway with percentage greater than 70% for both children and adults. Risk evaluation results illustrated that children in Chengdu might suffer noncarcinogenic risk when exposed to outdoor dust. Given that the cancer risk values of Pb and Cr larger than 1 × 10(-4), potential carcinogenic risk might occur for Chengdu residents through outdoor dust intake.

  15. Effect of current and atomized grain size distribution on the solidification of Plasma Transferred Arc coatings

    Danielle Bond

    2012-10-01

    Full Text Available Plasma Transferred Arc (PTA is the only thermal spray process that results in a metallurgical bond, being frequently described as a hardfacing process. The superior properties of coatings have been related to the fine microstructures obtained, which are finer than those processed under similar heat input with welding techniques using wire feedstock. This observation suggests that the atomized feedstock plays a role on the solidification of coatings. In this study a model for the role of the powders grains in the solidification of PTA coatings is put forward and discussed. An experiment was setup to discuss the model which involved the deposition of an atomized Co-based alloy with different grain size distributions and deposition currents. X ray diffraction showed that there were no phase changes due to the processing parameters. Microstructure analysis by Laser Confocal Microscopy, dilution with the substrate steel and Vickers microhardness were used the characterized coatings and enriched the discussion confirming the role of the powdered feedstock on the solidification of coatings.

  16. Distributed systems status and control

    Kreidler, David; Vickers, David

    1990-01-01

    Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

  17. TESTING THE GRAIN-SIZE DISTRIBUTION DETERMINED BY LASER DIFFRACTOMETRY FOR SICILIAN SOILS

    Costanza Di Stefano

    2012-06-01

    Full Text Available In this paper the soil grain-size distribution determined by Laser Diffraction method (LDM is tested using the Sieve-Hydrometer method (SHM applied for 747 soil samples representing a different texture classification, sampled in Sicily. 005_Di_Stefano(599_39 28-12-2011 15:01 Pagina 45 The analysis showed that the sand content measured by SHM can be assumed equal to the one determined by LDM. An underestimation of the clay fraction measured by LDM was obtained with respect to the SHM and a set of equations useful to refer laser diffraction measurements to SHM was calibrated using the measurements carried out for 635 soil samples. Finally, the proposed equations were tested using independent measurements carried out by LDM and SHM for 112 soil samples with a different texture classification.

  18. Water Treatment Technology - Distribution Systems.

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on distribution systems provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pipe for distribution systems, types…

  19. Physical properties of five grain dust types.

    Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

    1986-01-01

    Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less tha...

  20. A high sensitivity optically stimulated luminescence scanning system for measurement of single sand-sized grains

    Duller, G.A.T.; Bøtter-Jensen, L.; Kohsiek, P.

    1999-01-01

    An instrument has been designed for the routine analysis of the optically stimulated luminescence signal from single grains of sand. The system is capable of analysing over 3000 individual grains in a single measurement sequence, and the OSL signal from each grain can be read in less than 3 s....... The design principles are described, along with preliminary measurements that illustrate the operation of the system and its capabilities....

  1. Effect of dust size distribution on ion-acoustic solitons in dusty plasmas with different dust grains

    Gao, Dong-Ning; Yang, Yang; Yan, Qiang [Northwest Normal University, College of Physics and Electronic Engineering (China); Wang, Xiao-Yun [Lanzhou Jiao Tong University, Department of Mathematics and Physics (China); Duan, Wen-Shan, E-mail: duanws@126.com [Northwest Normal University, College of Physics and Electronic Engineering (China)

    2017-02-15

    Theoretical studies are carried out for ion acoustic solitons in multicomponent nonuniform plasma considering the dust size distribution. The Korteweg−de Vries equation for ion acoustic solitons is given by using the reductive perturbation technique. Two special dust size distributions are considered. The dependences of the width and amplitude of solitons on dust size parameters are shown. It is found that the properties of a solitary wave depend on the shape of the size distribution function of dust grains.

  2. An Overview of Grain Growth Theories for Pure Single Phase Systems,

    1986-10-01

    the fundamental causes for these distributions. This Blanc and Mocellin (1979) and Carnal and Mocellin (1981j set out to do. 7.1 Monte-Carlo Simulations...termed event B) (in 2-D) of 3-sided grains. (2) Neighbour-switching (termed event C). Blanc and Mocellin (1979) dealt with 2-D sections through...Kurtz and Carpay (1980a). 7.2 Analytical Method to Obtain fn Carnal and Mocellin (1981) obtained the distribution of grain coordination numbers in

  3. Toward multiscale modelings of grain-fluid systems

    Chareyre, Bruno; Yuan, Chao; Montella, Eduard P.; Salager, Simon

    2017-06-01

    Computationally efficient methods have been developed for simulating partially saturated granular materials in the pendular regime. In contrast, one hardly avoid expensive direct resolutions of 2-phase fluid dynamics problem for mixed pendular-funicular situations or even saturated regimes. Following previous developments for single-phase flow, a pore-network approach of the coupling problems is described. The geometry and movements of phases and interfaces are described on the basis of a tetrahedrization of the pore space, introducing elementary objects such as bridge, meniscus, pore body and pore throat, together with local rules of evolution. As firmly established local rules are still missing on some aspects (entry capillary pressure and pore-scale pressure-saturation relations, forces on the grains, or kinetics of transfers in mixed situations) a multi-scale numerical framework is introduced, enhancing the pore-network approach with the help of direct simulations. Small subsets of a granular system are extracted, in which multiphase scenario are solved using the Lattice-Boltzman method (LBM). In turns, a global problem is assembled and solved at the network scale, as illustrated by a simulated primary drainage.

  4. The THUDSOS Distributed Operating System

    廖先Zhi; 刘旭峰; 等

    1991-01-01

    The THUDSOS is a distributed operating system modeled as an abstract machine which provides decentralized control,transparency,availability,and reliability,as welol as a good degree of autonomy at each node,that makes our distributed system usable.Our operating system supports transparent access to data through network wide filesystem.The simultaneous access to any device is discussed for the case when the peripherals are treated as files.This operating system allows spawning of parallel application programs to solve problems in the fields,such as numerical analysis and artificial intelligence.

  5. Energy efficient distributed computing systems

    Lee, Young-Choon

    2012-01-01

    The energy consumption issue in distributed computing systems raises various monetary, environmental and system performance concerns. Electricity consumption in the US doubled from 2000 to 2005.  From a financial and environmental standpoint, reducing the consumption of electricity is important, yet these reforms must not lead to performance degradation of the computing systems.  These contradicting constraints create a suite of complex problems that need to be resolved in order to lead to 'greener' distributed computing systems.  This book brings together a group of outsta

  6. Grain size distribution of soils within the Cordillera Blanca, Peru: An indicator of basic mechanical properties for slope stability evaluation

    Novotný, J.; Klimeš, Jan

    2014-01-01

    Roč. 11, č. 3 (2014), s. 563-577 ISSN 1672-6316 R&D Projects: GA ČR(CZ) GAP209/11/1000 Institutional support: RVO:67985891 Keywords : moraines * grain size distribution * shear strength * hydraulic conductivity * Cordillera Blanca Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.963, year: 2014

  7. Coordination control of distributed systems

    Villa, Tiziano

    2015-01-01

    This book describes how control of distributed systems can be advanced by an integration of control, communication, and computation. The global control objectives are met by judicious combinations of local and nonlocal observations taking advantage of various forms of communication exchanges between distributed controllers. Control architectures are considered according to  increasing degrees of cooperation of local controllers:  fully distributed or decentralized control,  control with communication between controllers,  coordination control, and multilevel control.  The book covers also topics bridging computer science, communication, and control, like communication for control of networks, average consensus for distributed systems, and modeling and verification of discrete and of hybrid systems. Examples and case studies are introduced in the first part of the text and developed throughout the book. They include: control of underwater vehicles, automated-guided vehicles on a container terminal, contro...

  8. Experimental Study of Paddy Grain Drying in Continuous Recirculation System Pneumatic Conveyor

    Prasetyo Totok

    2018-01-01

    Full Text Available Nowadays, paddy drying using conventional method is irrelevant to used. The increasing need of grain each year is one of the main factor that pushes scientist to invent new methods of drying paddy grain. The old method is unusefull since it takes up space, needed the sun as the drying media which causes a long drying time. One of the alternative of drying paddy grain is by using mechanic dryer. By using this dryer type, the process of drying takes faster comparing to the old method and the distribution of grain is supplied continuously. The dryer which uses pneumatic conveyor can be one of the solution due to its less energy consumption, a better drying result, and high drying capacity. The variable used to identify drying performance is temperature and loading weight. From the experiment, it is resulted that the best temperature for drying paddy grain is 60°C with the weight loading of 150 gram.

  9. Coarse-grained modeling of hybrid block copolymer system

    Su, Yongrui

    This thesis is comprised of three major projects of my research. In the first project, I proposed a nanoparticle model and combined it with the Theoretically Informed Coarse Grained (TICG) model for pure polymer systems and the grand canonical slip springs model developed in our group to build a new model for entangled nanocomposites. With Molecule Dynamics(MD) simulation, I studied the mechanic properties of the nanocomposites, for example the influence of nanoparticles size and volume fraction on entanglements, the diffusion of polymers and nanoparticles, and the influence of nanoparticles size and volume fraction on viscosity et al.. We found that the addition of small-size nanoparticles reduces the viscosity of the nanocomposites, which is in contrary to what Einstein predicted a century ago. However, when particle increases its size to micrometers the Einstein predictions is recovered. From our simulation, we believe that small-size nanoparticles can more effectively decrease the entanglements of nanocomposites than larger particles. The free volume effect introduced by small-size nanoparticles also helps decrease the viscosity of the whole system. In the second project, I combined the Ohta-Kawasaki (OK) model [3] and the Covariance Matrix Adaptation Evolutionary Strategy(CMA-ES) to optimize the block copolymer blends self-assembly in the hole-shrink process. The aim is to predict the optimal composition and the optimal surface energy to direct the block copolymer blends self-assembly process in the confined hole. After optimization in the OK model, we calibrated the optimal results by the more reliable TICG model and got the same morphology. By comparing different optimization process, we found that the homopolymers which are comprised of the same monomers as either block of the block copolymer can form a perfect perforated hole and might have better performance than the pure block copolymer. While homopolymers which are comprised of a third-party monomers

  10. RBAC administration in distributed systems

    Dekker, M.A.C.; Crampton, J.; Etalle, Sandro; Li, N.

    Large and distributed access control systems are increasingly common, for example in health care. In such settings, access control policies may become very complex, thus complicating correct and efficient adminstration of the access control system. Despite being one of the most widely used access

  11. Distributed design approach in persistent identifiers systems

    Golodoniuc, Pavel; Car, Nicholas; Klump, Jens

    2017-04-01

    The need to identify both digital and physical objects is ubiquitous in our society. Past and present persistent identifier (PID) systems, of which there is a great variety in terms of technical and social implementations, have evolved with the advent of the Internet, which has allowed for globally unique and globally resolvable identifiers. PID systems have catered for identifier uniqueness, integrity, persistence, and trustworthiness, regardless of the identifier's application domain, the scope of which has expanded significantly in the past two decades. Since many PID systems have been largely conceived and developed by small communities, or even a single organisation, they have faced challenges in gaining widespread adoption and, most importantly, the ability to survive change of technology. This has left a legacy of identifiers that still exist and are being used but which have lost their resolution service. We believe that one of the causes of once successful PID systems fading is their reliance on a centralised technical infrastructure or a governing authority. Golodoniuc et al. (2016) proposed an approach to the development of PID systems that combines the use of (a) the Handle system, as a distributed system for the registration and first-degree resolution of persistent identifiers, and (b) the PID Service (Golodoniuc et al., 2015), to enable fine-grained resolution to different information object representations. The proposed approach solved the problem of guaranteed first-degree resolution of identifiers, but left fine-grained resolution and information delivery under the control of a single authoritative source, posing risk to the long-term availability of information resources. Herein, we develop these approaches further and explore the potential of large-scale decentralisation at all levels: (i) persistent identifiers and information resources registration; (ii) identifier resolution; and (iii) data delivery. To achieve large-scale decentralisation

  12. Size and density distribution of very small dust grains in the Barnard 5 cloud

    Lis, Dariusz C.; Leung, Chun Ming

    1991-01-01

    The effects of the temperature fluctuations in small graphite grains on the energy spectrum and the IR surface brightness of an isolated dust cloud heated externally by the interstellar radiation field were investigated using a series of models based on a radiation transport computer code. This code treats self-consistently the thermal coupling between the transient heating of very small dust grains and the equilibrium heating of conventional large grains. The model results were compared with the IRAS observations of the Barnard 5 (B5) cloud, showing that the 25-micron emission of the cloud must be produced by small grains with a 6-10 A radius, which also contribute about 50 percent to the observed 12-micron emission. The remaining 12 micron flux may be produced by the polycyclic aromatic hydrocarbons. The 60-and 100-micron radiation is dominated by emission from large grains heated under equilibrium conditions.

  13. Systems Measures of Water Distribution System Resilience

    Klise, Katherine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Murray, Regan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Walker, La Tonya Nicole [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Resilience is a concept that is being used increasingly to refer to the capacity of infrastructure systems to be prepared for and able to respond effectively and rapidly to hazardous events. In Section 2 of this report, drinking water hazards, resilience literature, and available resilience tools are presented. Broader definitions, attributes and methods for measuring resilience are presented in Section 3. In Section 4, quantitative systems performance measures for water distribution systems are presented. Finally, in Section 5, the performance measures and their relevance to measuring the resilience of water systems to hazards is discussed along with needed improvements to water distribution system modeling tools.

  14. THE FRANCHISE SYSTEM OF DISTRIBUTION.

    The working relationships between franchise companies and their franchised dealers are analyzed. The benefits derived from the use of a franchisesise...system of distribution for both the franchisor and franchisee are determined. The principal problems encountered by the parties to the franchise ...agreement are isolated, and this method of distribution is evaluated from the standpoint of both the franchise company and franchised dealers and to assess its impact on the marketing economy of the nation.

  15. Maintaining consistency in distributed systems

    Birman, Kenneth P.

    1991-01-01

    In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability.

  16. Distribution network strengthens sales systems

    Janoska, J.

    2003-01-01

    Liberalisation of the electricity market pushes Slovak distribution companies to upgrade their sale technologies. The first one to invest into a complex electronic sales system will be Stredoslovenska energetika, a.s., Zilina. The system worth 200 million Sk (4,83 million Euro) will be supplied by Polish software company Winuel. The company should also supply a software that would allow forecasting and planning of sales. The system should be fully operational by 2006. TREND has not managed to obtain information regarding plans Zapadoslovenska energetika - the largest and most active distribution company - might have in this area. In eastern Slovakia distribution company Vychodoslovenska energetika, a.s., Kosice has also started addressing this issue. (Author)

  17. Effect of Grain Orientation and Boundary Distributions on Hydrogen-Induced Cracking in Low-Carbon-Content Steels

    Masoumi, Mohammad; Coelho, Hana Livia Frota; Tavares, Sérgio Souto Maior; Silva, Cleiton Carvalho; de Abreu, Hamilton Ferreira Gomes

    2017-08-01

    Hydrogen-induced cracking (HIC) causes considerable economic losses in a wide range of steels exposed to corrosive environments. The effect of crystallographic texture and grain boundary distributions tailored by rolling at 850 °C in three different steels with a body-centered cube structure was investigated on HIC resistance. The x-ray and electron backscattered diffraction techniques were used to characterize texture evolutions during the rolling process. The findings revealed a significant improvement against HIC based on texture engineering. In addition, increasing the number of {111} and {110} grains, associated with minimizing the number of {001} grains in warm-rolled samples, reduced HIC susceptibility. Moreover, the results showed that boundaries associated with low {hkl} indexing and denser packing planes had more resistance against crack propagation.

  18. Analysis of Grain Size Distribution and Hydraulic Conductivity for a Variety of Sediment Types with Application to Wadi Sediments

    Rosas Aguilar, Jorge

    2013-05-01

    Grain size distribution, porosity, and hydraulic conductivity from over 400 unlithified sediment samples were analized. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations commonly used to estimate hydraulic conductivity from grain size analyses. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values. Modifications of the empirical equations, including changes to special coefficients and statistical off sets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, off shore marine, and wadi sediments. Expected hydraulic conductivity estimation errors were reduced. Correction factors were proposed for wadi sediments, taking mud percentage and the standard deviation (in phi units) into account.

  19. Activity of some isoenzymatic systems in stored coffee grains

    Reni Saath

    2014-02-01

    Full Text Available Considering the worldwide consumption of coffee, it is natural that throughout the history many people have dedicated the research to markers that contribute somehow on gauging its quality. This research aimed to evaluate the biochemical performance of arabica coffee during storage. Coffee in beans (natural and in parchment (pulped dried in concrete terrace and in dryer with heated air were packed in jute bags and stored in not controlled environmental conditions. Enzymatic activities of superoxide dismutase, catalase, peroxidase, polyphenoloxidase, esterase and lipoxygenase in coffee grains were evaluated at zero, three, six, nine and twelve months by means of electrophoresis. Independently of the drying method, the activity of isoenzymatic complexes highlighted deteriorative processes in stored grains of coffee. The treatments 60/40º C and 60º C used to reduce the water content imposed a greater stress condition, accelerated metabolism of natural coffee in the storage with decreased activity of defense mechanisms due to latent damage in these grains. Natural coffees are more sensible to high drying temperatures and its quality reduces faster than pulped coffee in the storage.

  20. Compressed sensing for distributed systems

    Coluccia, Giulio; Magli, Enrico

    2015-01-01

    This book presents a survey of the state-of-the art in the exciting and timely topic of compressed sensing for distributed systems. It has to be noted that, while compressed sensing has been studied for some time now, its distributed applications are relatively new. Remarkably, such applications are ideally suited to exploit all the benefits that compressed sensing can provide. The objective of this book is to provide the reader with a comprehensive survey of this topic, from the basic concepts to different classes of centralized and distributed reconstruction algorithms, as well as a comparison of these techniques. This book collects different contributions on these aspects. It presents the underlying theory in a complete and unified way for the first time, presenting various signal models and their use cases. It contains a theoretical part collecting latest results in rate-distortion analysis of distributed compressed sensing, as well as practical implementations of algorithms obtaining performance close to...

  1. Enhanced distributed energy resource system

    Atcitty, Stanley [Albuquerque, NM; Clark, Nancy H [Corrales, NM; Boyes, John D [Albuquerque, NM; Ranade, Satishkumar J [Las Cruces, NM

    2007-07-03

    A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

  2. Distributed Supervisory Protection Interlock System

    Walz, H.V.; Agostini, R.C.; Barker, L.; Cherkassky, R.; Constant, T.; Matheson, R.

    1989-03-01

    The Distributed Supervisory Protection Interlock System, DSPI, is under development at the Stanford Linear Accelerator Center for requirements in the areas of personnel protection, beam containment and equipment protection interlocks. The DSPI system, distributed over the application site, consists of segments with microprocessor-based controller and I/O modules, local area networks for communication, and a global supervisor computer. Segments are implemented with commercially available controller and I/O modules arranged in local interlock clusters, and associated software. Segments provide local interlock data acquisition, processing and control. Local area networks provide the communication backbone between segments and a global supervisor processor. The supervisor processor monitors the overall system, reports detail status and provides human interfaces. Details of an R and D test system, which will implement the requirements for personnel protection of 4 typical linear accelerator sectors, will be described. 4 refs., 2 figs

  3. Distributed Systems: The Hard Problems

    CERN. Geneva

    2015-01-01

    **Nicholas Bellerophon** works as a client services engineer at Basho Technologies, helping customers setup and run distributed systems at scale in the wild. He has also worked in massively multiplayer games, and recently completed a live scalable simulation engine. He is an avid TED-watcher with interests in many areas of the arts, science, and engineering, including of course high-energy physics.

  4. Distribution system analysis and automation

    Gers, Juan

    2013-01-01

    A comprehensive guide to techniques that allow engineers to simulate, analyse and optimise power distribution systems which combined with automation, underpin the emerging concept of the "smart grid". This book is supported by theoretical concepts with real-world applications and MATLAB exercises.

  5. Turboelectric Distributed Propulsion System Modelling

    Liu, Chengyuan

    2013-01-01

    The Blended-Wing-Body is a conceptual aircraft design with rear-mounted, over wing engines. Turboelectric distributed propulsion system with boundary layer ingestion has been considered for this aircraft. It uses electricity to transmit power from the core turbine to the fans, therefore dramatically increases bypass ratio to reduce fuel consumption and noise. This dissertation presents methods on designing the TeDP system, evaluating effects of boundary layer ingestion, modelling engine perfo...

  6. A Distributed User Information System

    1990-03-01

    NOE08 Department of Computer Science NOVO 8 1990 University of Maryland S College Park, MD 20742 D Abstract Current user information database technology ...Transactions on Computer Systems, May 1988. [So189] K. Sollins. A plan for internet directory services. Technical report, DDN Network Information Center...2424 A Distributed User Information System DTiC Steven D. Miller, Scott Carson, and Leo Mark DELECTE Institute for Advanced Computer Studies and

  7. The ATLAS distributed analysis system

    Legger, F

    2014-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  8. The ATLAS distributed analysis system

    Legger, F.; Atlas Collaboration

    2014-06-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  9. Development and characterization of food-grade tracers for the global grain tracing and recall system.

    Lee, Kyung-Min; Armstrong, Paul R; Thomasson, J Alex; Sui, Ruixiu; Casada, Mark; Herrman, Timothy J

    2010-10-27

    Tracing grain from the farm to its final processing destination as it moves through multiple grain-handling systems, storage bins, and bulk carriers presents numerous challenges to existing record-keeping systems. This study examines the suitability of coded caplets to trace grain, in particular, to evaluate methodology to test tracers' ability to withstand the rigors of a commercial grain handling and storage systems as defined by physical properties using measurement technology commonly applied to assess grain hardness and end-use properties. Three types of tracers to dispense into bulk grains for tracing the grain back to its field of origin were developed using three food-grade substances [processed sugar, pregelatinized starch, and silicified microcrystalline cellulose (SMCC)] as a major component in formulations. Due to a different functionality of formulations, the manufacturing process conditions varied for each tracer type, resulting in unique variations in surface roughness, weight, dimensions, and physical and spectroscopic properties before and after coating. The applied two types of coating [pregelatinized starch and hydroxypropylmethylcellulose (HPMC)] using an aqueous coating system containing appropriate plasticizers showed uniform coverage and clear coating. Coating appeared to act as a barrier against moisture penetration, to protect against mechanical damage of the surface of the tracers, and to improve the mechanical strength of tracers. The results of analysis of variance (ANOVA) tests showed the type of tracer, coating material, conditioning time, and a theoretical weight gain significantly influenced the morphological and physical properties of tracers. Optimization of these factors needs to be pursued to produce desirable tracers with consistent quality and performance when they flow with bulk grains throughout the grain marketing channels.

  10. Distributed optimization system and method

    Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

    2003-06-10

    A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

  11. Effects of oxide distributed in grain boundaries on microstructure stability of nanocrystalline metals

    Zhou, Kai; Li, Hui; Biao Pang, Jin; Wang, Zhu

    2013-06-01

    Nanocrystalline copper and zinc prepared by high-pressure compaction method have been studied by positron lifetime spectroscopy associated with X-ray diffraction. For nanocrystalline Cu, mean grain sizes of the samples decrease after being annealed at 900 °C and increase during aging at 180 °C, revealing that the atoms exchange between the two regions. The positron lifetime results indicate that the vacancy clusters formed in the annealing process are unstable and decomposed at the aging time below 6 hours. In addition, the partially oxidized surfaces of the nanoparticles hinder the grain growth during the ageing at 180 °C, and the vacancy clusters inside the disorder regions which are related to Cu2O need longer aging time to decompose. In the case of nanocrystalline Zn, the open volume defect (not larger than divacancy) is dominant according to the high relative intensity for the short positron lifetime (τ1). The oxide (ZnO) inside the grain boundaries has been found having an effect to hinder the decrease of average positron lifetime (τav) during the annealing, which probably indicates that the oxide stabilizes the microstructure of the grain boundaries. For both nanocrystalline copper and zinc, the oxides in grain boundaries enhance the thermal stability of the microstucture, in spite of their different crystal structures. This effect is very important for the nanocrystalline materials using as radiation resistant materials.

  12. Effects of oxide distributed in grain boundaries on microstructure stability of nanocrystalline metals

    Zhou Kai; Li Hui; Pang Jinbiao; Wang Zhu

    2013-01-01

    Nanocrystalline copper and zinc prepared by high-pressure compaction method have been studied by positron lifetime spectroscopy associated with X-ray diffraction. For nanocrystalline Cu, mean grain sizes of the samples decrease after being annealed at 900 °C and increase during aging at 180 °C, revealing that the atoms exchange between the two regions. The positron lifetime results indicate that the vacancy clusters formed in the annealing process are unstable and decomposed at the aging time below 6 hours. In addition, the partially oxidized surfaces of the nanoparticles hinder the grain growth during the ageing at 180 °C, and the vacancy clusters inside the disorder regions which are related to Cu 2 O need longer aging time to decompose. In the case of nanocrystalline Zn, the open volume defect (not larger than divacancy) is dominant according to the high relative intensity for the short positron lifetime (τ 1 ). The oxide (ZnO) inside the grain boundaries has been found having an effect to hinder the decrease of average positron lifetime (τ av ) during the annealing, which probably indicates that the oxide stabilizes the microstructure of the grain boundaries. For both nanocrystalline copper and zinc, the oxides in grain boundaries enhance the thermal stability of the microstucture, in spite of their different crystal structures. This effect is very important for the nanocrystalline materials using as radiation resistant materials.

  13. Numerical simulation of temperature distribution using finite difference equations and estimation of the grain size during friction stir processing

    Arora, H.S.; Singh, H.; Dhindaw, B.K.

    2012-01-01

    Highlights: ► Magnesium alloy AE42 was friction stir processed under different cooling conditions. ► Heat flow model was developed using finite difference heat equations. ► Generalized MATLAB code was developed for solving heat flow model. ► Regression equation for estimation of grain size was developed. - Abstract: The present investigation is aimed at developing a heat flow model to simulate temperature history during friction stir processing (FSP). A new approach of developing implicit form of finite difference heat equations solved using MATLAB code was used. A magnesium based alloy AE42 was friction stir processed (FSPed) at different FSP parameters and cooling conditions. Temperature history was continuously recorded in the nugget zone during FSP using data acquisition system and k type thermocouples. The developed code was validated at different FSP parameters and cooling conditions during FSP experimentation. The temperature history at different locations in the nugget zone at different instants of time was further utilized for the estimation of grain growth rate and final average grain size of the FSPed specimen. A regression equation relating the final grain size, maximum temperature during FSP and the cooling rate was developed. The metallurgical characterization was done using optical microscopy, SEM, and FIB-SIM analysis. The simulated temperature profiles and final average grain size were found to be in good agreement with the experimental results. The presence of fine precipitate particles generated in situ in the investigated magnesium alloy also contributed in the evolution of fine grain structure through Zener pining effect at the grain boundaries.

  14. World-wide distribution automation systems

    Devaney, T.M.

    1994-01-01

    A worldwide power distribution automation system is outlined. Distribution automation is defined and the status of utility automation is discussed. Other topics discussed include a distribution management system, substation feeder, and customer functions, potential benefits, automation costs, planning and engineering considerations, automation trends, databases, system operation, computer modeling of system, and distribution management systems

  15. Distributed Persistent Identifiers System Design

    Pavel Golodoniuc

    2017-06-01

    Full Text Available The need to identify both digital and physical objects is ubiquitous in our society. Past and present persistent identifier (PID systems, of which there is a great variety in terms of technical and social implementation, have evolved with the advent of the Internet, which has allowed for globally unique and globally resolvable identifiers. PID systems have, by in large, catered for identifier uniqueness, integrity, and persistence, regardless of the identifier’s application domain. Trustworthiness of these systems has been measured by the criteria first defined by Bütikofer (2009 and further elaborated by Golodoniuc 'et al'. (2016 and Car 'et al'. (2017. Since many PID systems have been largely conceived and developed by a single organisation they faced challenges for widespread adoption and, most importantly, the ability to survive change of technology. We believe that a cause of PID systems that were once successful fading away is the centralisation of support infrastructure – both organisational and computing and data storage systems. In this paper, we propose a PID system design that implements the pillars of a trustworthy system – ensuring identifiers’ independence of any particular technology or organisation, implementation of core PID system functions, separation from data delivery, and enabling the system to adapt for future change. We propose decentralisation at all levels — persistent identifiers and information objects registration, resolution, and data delivery — using Distributed Hash Tables and traditional peer-to-peer networks with information replication and caching mechanisms, thus eliminating the need for a central PID data store. This will increase overall system fault tolerance thus ensuring its trustworthiness. We also discuss important aspects of the distributed system’s governance, such as the notion of the authoritative source and data integrity

  16. Instabilities in vertically vibrated fluid-grain systems.

    King, P J; Lopez-Alcaraz, P; Pacheco-Martinez, H A; Clement, C P; Smith, A J; Swift, M R

    2007-03-01

    When a bed of fluid-immersed fine grains is exposed to vertical vibration a wealth of phenomena may be observed. At low frequencies a horizontal bed geometry is generally unstable and the bed breaks spatial symmetry, acquiring a tilt. At the same time it undergoes asymmetric granular convection. Fine binary mixtures may separate completely into layers or patterns of stripes. The separated regions may exhibit instabilities in which they undergo wave-like motion or exhibit quasi-periodic oscillations. We briefly review these and a number of related behaviours, identifying the physical mechanisms behind each. Finally, we discuss the magneto-vibratory separation of binary mixtures which results from exposing each component to a different effective gravity and describe the influence of a background fluid on this process.

  17. Distributed hierarchical radiation monitoring system

    Barak, D.

    1985-01-01

    A solution to the problem of monitoring the radiation levels in and around a nuclear facility is presented in this paper. This is a private case of a large scale general purpose data acqisition system with high reliability, availability and short maintenance time. The physical layout of the detectors in the plant, and the strict control demands dictated a distributed and hierarchical system. The system is comprised of three levels, each level contains modules. Level one contains the Control modules which collects data from groups of detectors and executes emergency local control tasks. In level two are the Group controllers which concentrate data from the Control modules, and enable local display and communication. The system computer is in level three, enabling the plant operator to receive information from the detectors and execute control tasks. The described system was built and is operating successfully for about two years. (author)

  18. Development of micro tensile testing method in an FIB system for evaluating grain boundary strength

    Fujii, Katsuhiko; Fukuya, Koji

    2010-01-01

    A micro tensile testing method for evaluating grain boundary strength was developed. Specimens of 2 x 2 x 10μm having one grain boundary were made by focused ion beam (FIB) micro-processing and tensioned in an FIB system in situ. The load was measured from the deflection of the silicon cantilever. The method was applied to aged and unaged Fe-Mn-P alloy specimens with different level of grain boundary phosphorus segregation. The load at intergranular fracture decreased with increasing phosphorus segregation. (author)

  19. Theoretical basis for transfer of laboratory test results of grain size distribution of coal to real object

    Sikora, W; Chodura, J [Politechnika Sladska, Gliwice (Poland). Instytut Mechanizacji Gornictwa

    1989-01-01

    Evaluates a method for forecasting size distribution of black coal mined by shearer loaders in one coal seam. Laboratory tests for determining coal comminution during cutting and haulage along the face are analyzed. Methods for forecasting grain size distribution of coal under operational conditions using formulae developed on the basis of laboratory tests are discussed. Recommendations for design of a test stand and test conditions are discussed. A laboratory stand should accurately model operational conditions of coal cutting, especially dimensions of the individual elements of the shearer loader, geometry of the cutting drum and cutting tools, and strength characteristics of the coal seam. 9 refs.

  20. Non-equilibrium grain boundary segregation of boron in austenitic stainless steel - IV. Precipitation behaviour and distribution of elements at grain boundaries

    Karlsson, L.; Norden, H.

    1988-01-01

    The distribution of elements and the precipitation behaviour at grain boundaries have been studied in boron containing AISI 316L and ''Mo-free AISI 316L'' type austenitic stainless steels. A combination of microanalytical techniques was used to study the boundary regions after cooling at 0.29-530 0 C/s from 800, 1075 or 1250 0 C. Tetragonal M/sub 2/B, M/sub 5/B/sub 3/ and M/sub 3/B/sub 2/, all rich in Fe, Cr and Mo, precipitated in the ''high B'' (40 ppm) AISI 316L steel whereas orthorhombic M/sub 2/B, rich in Cr and Fe was found in the ''Mo-free steel'' with 23 ppm B. In the ''high B steel'' a thin (<2nm), continuous layer, containing B, Cr, Mo and Fe and having a stoichiometry of typically M/sub 9/B, formed at boundaries after cooling at intermediate cooling rates. For both types of steels a boundary zone was found, after all heat treatments, with a composition differing significantly from the bulk composition. The differences were most marked after cooling at intermediate cooling rates. In both types of steel boundary depletion of Cr and enrichment of B and C occurred. It was found that non-equilibrium grain boundary segregation of boron can affect the precipitation behaviour by making the boundary composition enter a new phase field ''Non-equilibrium phases'' might also form. The synergistic effect of B and Mo on the boundary composition and precipitation behaviour, and the observed indications of C non-equilibrium segregation are discussed

  1. Reconstruction of Single-Grain Orientation Distribution Functions for Crystalline Materials

    Hansen, Per Christian; Sørensen, Henning Osholm; Sükösd, Zsuzsanna

    2009-01-01

    for individual grains of the material in consideration. We study two iterative large-scale reconstruction algorithms, the algebraic reconstruction technique (ART) and conjugate gradients for least squares (CGLS), and demonstrate that right preconditioning is necessary in both algorithms to provide satisfactory...

  2. Methods for analysis of the distribution and speciation of iron and zinc in the cereal grain

    Hansen, Thomas Hesselhøj

    , a novel high-throughput micro digestion method was developed, enabling the analysis of total element concentrations in small tissue fractions, such as the embryo of cereal grains. The method is based on small closed bombs that are microwaved and was validated for sample amounts between 1-20 mg using...

  3. A Fine-Grained Data Access Control System in Wireless Sensor Network

    Boniface K. Alese

    2015-12-01

    Full Text Available The evolving realities of Wireless Sensor Network (WSN deployed to various terrain of life require serving multiple applications. As large amount of sensed data are distributed and stored in individual sensors nodes, the illegal access to these sensitive data can be devastating. Consequently, data insecurity becomes a big concern. This study, therefore, proposes a fine-grained access control system which only requires the right set of users to access a particular data, based on their access privileges in the sensor networks. It is designed using Priccess Protocol with Access policy formulation adopting the principle of Bell Lapadula model as well as Attribute-Based Encryption (ABE to control access to sensor data. The functionality of the proposed system is simulated using Netbeans. The performance analysis of the proposed system using execution time and size of the key show that the higher the key size, the harder it becomes for the attacker to hack the system. Additionally, the time taken for the proposed work is lesser which makes the work faster than the existing work. Consequently, a well secure interactive web-based application that could facilitates the field officers access to stored data in safe and secure manner is developed.

  4. The ATLAS Distributed Analysis System

    Legger, F; The ATLAS collaboration; Pacheco Pages, A; Stradling, A

    2013-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high but steadily improving; grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters ...

  5. The ATLAS Distributed Analysis System

    Legger, F; The ATLAS collaboration

    2014-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high but steadily improving; grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters ...

  6. Distributed optimal coordination for distributed energy resources in power systems

    Wu, Di; Yang, Tao; Stoorvogel, A.

    2017-01-01

    Driven by smart grid technologies, distributed energy resources (DERs) have been rapidly developing in recent years for improving reliability and efficiency of distribution systems. Emerging DERs require effective and efficient coordination in order to reap their potential benefits. In this paper......, we consider an optimal DER coordination problem over multiple time periods subject to constraints at both system and device levels. Fully distributed algorithms are proposed to dynamically and automatically coordinate distributed generators with multiple/single storages. With the proposed algorithms...

  7. Sediment Sources and Transport Pathway Identification Based on Grain-Size Distributions on the SW Coast of Portugal

    Xiaoqin Du

    2015-01-01

    Full Text Available Espichel-Sines is an embayed coast in SW Portugal, consisting of two capes at both extremities, a tidal inlet and associated ebb tidal delta, a barrier spit, sandy beaches, sea cliffs, and a submarine canyon. Beach berm, backshore, near shore and inner shelf sediment samples were taken. Samples were analyzed for their grain-size compositions. This study ranks the hypothetical sediment sources influences on the sediment distributions in the study area using the multivariate Empirical Orthogonal Function (EOF techniques. Transport pathways in this study were independently identified using the grain size trend analysis (GSTA technique to verify the EOF findings. The results show that the cliff-erosion sediment is composed of pebbles and sand and is the most important sediment source for the entire embayment. The sediment at the inlet mouth is a mixture of pebbles, sand, silt, and clay, which is a minor sediment source that only has local influence. The overall grain-size distributions on the shelf are dominated by the sand except for the high mud content around the tidal delta front in the northern embayment. Sediment transport patterns on the inner shelf at the landward and north sides of the canyon head are landward and northward along the barrier spit, respectively. On the south side of the canyon head, the prevailing sediment transport is seaward. Sediment transport occurs in both directions along the shore.

  8. Small Aircraft Data Distribution System

    Chazanoff, Seth L.; Dinardo, Steven J.

    2012-01-01

    The CARVE Small Aircraft Data Distribution System acquires the aircraft location and attitude data that is required by the various programs running on a distributed network. This system distributes the data it acquires to the data acquisition programs for inclusion in their data files. It uses UDP (User Datagram Protocol) to broadcast data over a LAN (Local Area Network) to any programs that might have a use for the data. The program is easily adaptable to acquire additional data and log that data to disk. The current version also drives displays using precision pitch and roll information to aid the pilot in maintaining a level-level attitude for radar/radiometer mapping beyond the degree available by flying visually or using a standard gyro-driven attitude indicator. The software is designed to acquire an array of data to help the mission manager make real-time decisions as to the effectiveness of the flight. This data is displayed for the mission manager and broadcast to the other experiments on the aircraft for inclusion in their data files. The program also drives real-time precision pitch and roll displays for the pilot and copilot to aid them in maintaining the desired attitude, when required, during data acquisition on mapping lines.

  9. Effects of snow grain shape on climate simulations: sensitivity tests with the Norwegian Earth System Model

    P. Räisänen

    2017-12-01

    Full Text Available Snow consists of non-spherical grains of various shapes and sizes. Still, in radiative transfer calculations, snow grains are often treated as spherical. This also applies to the computation of snow albedo in the Snow, Ice, and Aerosol Radiation (SNICAR model and in the Los Alamos sea ice model, version 4 (CICE4, both of which are employed in the Community Earth System Model and in the Norwegian Earth System Model (NorESM. In this study, we evaluate the effect of snow grain shape on climate simulated by NorESM in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH is compared with another (NONSPH in which the snow shortwave single-scattering properties are based on a combination of three non-spherical snow grain shapes optimized using measurements of angular scattering by blowing snow. The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical case (0.77–0.78 in the visible region than in the spherical case ( ≈  0.89. Therefore, for the same effective snow grain size (or equivalently, the same specific projected area, the snow broadband albedo is higher when assuming non-spherical rather than spherical snow grains, typically by 0.02–0.03. Considering the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation with a global-mean top-of-the-model value of ca. −0.22 W m−2. Although this global-mean radiative effect is rather modest, the impacts on the climate simulated by NorESM are substantial. The global annual-mean 2 m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high latitudes. The climatic response is amplified by strong snow and sea ice feedbacks. It is further demonstrated that the effect of snow grain shape could be largely offset by adjusting the snow grain size. When assuming non-spherical snow grains with the parameterized grain

  10. Effects of snow grain shape on climate simulations: sensitivity tests with the Norwegian Earth System Model

    Räisänen, Petri; Makkonen, Risto; Kirkevåg, Alf; Debernard, Jens B.

    2017-12-01

    Snow consists of non-spherical grains of various shapes and sizes. Still, in radiative transfer calculations, snow grains are often treated as spherical. This also applies to the computation of snow albedo in the Snow, Ice, and Aerosol Radiation (SNICAR) model and in the Los Alamos sea ice model, version 4 (CICE4), both of which are employed in the Community Earth System Model and in the Norwegian Earth System Model (NorESM). In this study, we evaluate the effect of snow grain shape on climate simulated by NorESM in a slab ocean configuration of the model. An experiment with spherical snow grains (SPH) is compared with another (NONSPH) in which the snow shortwave single-scattering properties are based on a combination of three non-spherical snow grain shapes optimized using measurements of angular scattering by blowing snow. The key difference between these treatments is that the asymmetry parameter is smaller in the non-spherical case (0.77-0.78 in the visible region) than in the spherical case ( ≈ 0.89). Therefore, for the same effective snow grain size (or equivalently, the same specific projected area), the snow broadband albedo is higher when assuming non-spherical rather than spherical snow grains, typically by 0.02-0.03. Considering the spherical case as the baseline, this results in an instantaneous negative change in net shortwave radiation with a global-mean top-of-the-model value of ca. -0.22 W m-2. Although this global-mean radiative effect is rather modest, the impacts on the climate simulated by NorESM are substantial. The global annual-mean 2 m air temperature in NONSPH is 1.17 K lower than in SPH, with substantially larger differences at high latitudes. The climatic response is amplified by strong snow and sea ice feedbacks. It is further demonstrated that the effect of snow grain shape could be largely offset by adjusting the snow grain size. When assuming non-spherical snow grains with the parameterized grain size increased by ca. 70 %, the

  11. Molecular dynamics study of the role of symmetric tilt grain boundaries on the helium distribution in nickel

    Torres, E.; Pencer, J.

    2018-04-01

    Helium impurities, from either direct implantation or transmutation reactions, have been associated with embrittlement in nickel-based alloys. Helium has very low solubility in nickel, and has been found to aggregate at lattice defects such as vacancies, dislocations, and grain boundaries. The retention and precipitation of helium in nickel-based alloys have deleterious effects on the material mechanical properties. However, the underlying mechanisms that lead to helium effects in the host metal are not fully understood. In the present work, we investigate the role of symmetric tilt grain boundary (STGB) structures on the distribution of helium in nickel using molecular dynamics simulations. We investigate the family of STGBs specific to the 〈 110 〉 tilt axis. The present results indicate that accumulation of helium at the grain boundary may be modulated by details of grain boundary geometry. A plausible correlation between the grain boundary energy and misorientation with the accumulation and mobility of helium is proposed. Small clusters with up to 6 helium atoms show significant interstitial mobility in the nickel bulk, but also become sites for nucleation and grow of more stable helium clusters. High-energy GBs are found mainly populated with small helium clusters. The high mobility of small clusters along the GBs indicates the role of these GBs as fast two-dimensional channels for diffusion. In contrast, the accumulation of helium in large helium clusters at low-energy STGB creates a favorable environment for the formation of large helium bubbles, indicating a potential role for low-energy STGB in promoting helium-induced GB embrittlement.

  12. Fine-Grained Access Control for Electronic Health Record Systems

    Hue, Pham Thi Bach; Wohlgemuth, Sven; Echizen, Isao; Thuy, Dong Thi Bich; Thuc, Nguyen Dinh

    There needs to be a strategy for securing the privacy of patients when exchanging health records between various entities over the Internet. Despite the fact that health care providers such as Google Health and Microsoft Corp.'s Health Vault comply with the U.S Health Insurance Portability and Accountability Act (HIPAA), the privacy of patients is still at risk. Several encryption schemes and access control mechanisms have been suggested to protect the disclosure of a patient's health record especially from unauthorized entities. However, by implementing these approaches, data owners are not capable of controlling and protecting the disclosure of the individual sensitive attributes of their health records. This raises the need to adopt a secure mechanism to protect personal information against unauthorized disclosure. Therefore, we propose a new Fine-grained Access Control (FGAC) mechanism that is based on subkeys, which would allow a data owner to further control the access to his data at the column-level. We also propose a new mechanism to efficiently reduce the number of keys maintained by a data owner in cases when the users have different access privileges to different columns of the data being shared.

  13. Interstellar grains

    Hoyle, F.; Wickramasinghe, N.C.

    1980-11-01

    Interstellar extinction of starlight was observed and plotted as a function of inverse wavelength. Agreement with the calculated effects of the particle distribution is shown. The main kinds of grain distinguished are: (1) graphite spheres of radius 0.02 microns, making up 10% of the total grain mass (2) small dielectric spheres of radius 0.04 microns making up 25% and (3) hollow dielectric cylinders containing metallic iron, with diameters of 2/3 microns making up 45%. The remaining 20% consists of other metals, metal oxides, and polysiloxanes. Absorption factor evidence suggests that the main dielectric component of the grains is organic material.

  14. FROM ATOMISTIC TO SYSTEMATIC COARSE-GRAINED MODELS FOR MOLECULAR SYSTEMS

    Harmandaris, Vagelis

    2017-10-03

    The development of systematic (rigorous) coarse-grained mesoscopic models for complex molecular systems is an intense research area. Here we first give an overview of methods for obtaining optimal parametrized coarse-grained models, starting from detailed atomistic representation for high dimensional molecular systems. Different methods are described based on (a) structural properties (inverse Boltzmann approaches), (b) forces (force matching), and (c) path-space information (relative entropy). Next, we present a detailed investigation concerning the application of these methods in systems under equilibrium and non-equilibrium conditions. Finally, we present results from the application of these methods to model molecular systems.

  15. Effect of Grain Boundary Character Distribution on the Impact Toughness of 410NiMo Weld Metal

    Divya, M.; Das, Chitta Ranjan; Chowdhury, Sandip Ghosh

    2016-01-01

    Grain boundary character distributions in 410NiMo weld metal were studied in the as-welded, first-stage, and second-stage postweld heat treatment (PWHT) conditions, and these were correlated with the Charpy-V impact toughness values of the material. The high impact toughness values in the weld...... metal in the as-welded and first-stage PWHT conditions compared to that in the second-stage condition are attributed to the higher fraction of low-energy I pound boundaries. A higher volume fraction of retained austenite and coarser martensite after second-stage PWHT accompanied by the formation...... in the impact toughness. In addition to this, grain refinement during 4-hour PWHT in the second stage also increased the toughness of the weld metal....

  16. Time evolution of coarse-grained entropy in classical and quantum motions of strongly chaotic systems

    Gu, Yan; Wang, Jiao

    1997-02-01

    We study relaxation of an ensemble of cat maps with initially localized phase-space distributions. Calculations of the coarse-grained entropy Sɛ ( t) for both classical and quantum motions are presented. It is shown that, within the relaxation period, both classical and quantum entropies increase with a nearly constant rate which can be identified as the largest Lyapunov exponent of the classical cat. After an empirical relaxation time, the time behavior for two entropies becomes different. While the classical entropy increases to the equilibrium entropy Seqm and stays there, its quantum analogue fluctuates incessantly around a mean overlineSɛ which is less than Seqm. We regard the entropy difference ΔS = S eqm - overlineSɛ as a measure of nonergodicity of the quantum motion of strongly chaotic systems and investigate its dependence on the Planck constant h. For fixed initial phase-space distributions, numerical results suggest that there is a scaling law ΔSαhβ with β ≈ 0.72 in the semiclassical regime.

  17. 3-D and quasi-2-D discrete element modeling of grain commingling in a bucket elevator boot system

    Unwanted grain commingling impedes new quality-based grain handling systems and has proven to be an expensive and time consuming issue to study experimentally. Experimentally validated models may reduce the time and expense of studying grain commingling while providing additional insight into detail...

  18. Application of binomial and multinomial probability statistics to the sampling design process of a global grain tracing and recall system

    Small, coded, pill-sized tracers embedded in grain are proposed as a method for grain traceability. A sampling process for a grain traceability system was designed and investigated by applying probability statistics using a science-based sampling approach to collect an adequate number of tracers fo...

  19. Video distribution system cost model

    Gershkoff, I.; Haspert, J. K.; Morgenstern, B.

    1980-01-01

    A cost model that can be used to systematically identify the costs of procuring and operating satellite linked communications systems is described. The user defines a network configuration by specifying the location of each participating site, the interconnection requirements, and the transmission paths available for the uplink (studio to satellite), downlink (satellite to audience), and voice talkback (between audience and studio) segments of the network. The model uses this information to calculate the least expensive signal distribution path for each participating site. Cost estimates are broken downy by capital, installation, lease, operations and maintenance. The design of the model permits flexibility in specifying network and cost structure.

  20. Effect of subsoil tillage depth on nutrient accumulation, root distribution, and grain yield in spring maize

    Hongguang Cai

    2014-10-01

    Full Text Available A four-year field experiment was conducted to investigate the effect of subsoiling depth on root morphology, nitrogen (N, phosphorus (P, and potassium (K uptake, and grain yield of spring maize. The results indicated that subsoil tillage promoted root development, increased nutrient accumulation, and increased yield. Compared with conventional soil management (CK, root length, root surface area, and root dry weight at 0–80 cm soil depth under subsoil tillage to 30 cm (T1 and subsoil tillage to 50 cm (T2 were significantly increased, especially the proportions of roots in deeper soil. Root length, surface area, and dry weight differed significantly among three treatments in the order of T2 > T1 > CK at the 12-leaf and early filling stages. The range of variation of root diameter in different soil layers in T2 treatment was the smallest, suggesting that roots were more likely to grow downwards with deeper subsoil tillage in soil. The accumulation of N, P, and K in subsoil tillage treatment was significantly increased, but the proportions of kernel and straw were different. In a comparison of T1 with T2, the grain accumulated more N and P, while K accumulation in kernel and straw varied in different years. Grain yield and biomass were increased by 12.8% and 14.6% on average in subsoil tillage treatments compared to conventional soil treatment. Although no significant differences between different subsoil tillage depths were observed for nutrient accumulation and grain yield, lodging resistance of plants was significantly improved in subsoil tillage to 50 cm, a characteristic that favors a high and stable yield under extreme environments.

  1. Quantity, size and distribution of borides for aluminium grain refinement by neutron-induced autoradiography (NIAR). Pt. 2

    Rachlitz, R.; Gaertner, S.; Holze, J.; Krumnacker, M.

    1990-01-01

    Al-Ti-B grain refiners improve the cast structure of aluminium and its alloys, but also cause problems related to the great hardness of the borides and their tendency to agglomerate and settle. Accurate information about the distribution, quantity and size of the TiB 2 particles is needed if material properties are to be improved and the quantity of additives minimized. This information is obtained mostly by NIAR. In laboratory-scale tests Al 99.8 and Al 99.5 were refined using different master alloys added in various quantities. In all cases the commercial master alloy gave the best refining effect. Besides boride particle size distribution and the presence of nuclei and nucleus stabilizers, morphological properties (duplex particles) are obviously of essential importance. It has been demonstrated that the TiB 2 size distribution values determined by NIAR are comparable with those established by optical microscopy measurements. (orig.) [de

  2. Embedded system in Arduino platform with Fuzzy control to support the grain aeration decision

    Albino Szesz Junior

    Full Text Available ABSTRACT: Aeration is currently the most commonly used technique to improve the drying and storage of grain, depending on temperature and water content of the grain, as of the temperature and relative humidity of the outside air. In order to monitor temperature and humidity of the grain mass, it is possible to have a network of sensors in the cells of both internal and external storage. Use of artificial intelligence through Fuzzy theory, has been used since the 60s and enables their application on various forms. Thus, it is observed that the aeration of grain in function of representing a system of controlled environment can be studied in relation to the application of this theory. Therefore, the aim of this paper is to present an embedded Fuzzy control system based on the mathematical model of CRUZ et al. (2002 and applied to the Arduino platform, for decision support in aeration of grain. For this, an embedded Arduino system was developed, which received the environmental values of temperature and humidity to then be processed in a Fuzzy controller and return the output as a recommendation to control the aeration process rationally. Comparing the results obtained from the graph presented by LASSERAN (1981 it was observed that the system is effective.

  3. Distribution system protection with communication technologies

    Wei, Mu; Chen, Zhe

    2010-01-01

    Due to the communication technologies’ involvement in the distribution power system, the time-critical protection function may be implemented more accurately, therefore distribution power systems’ stability, reliability and security could be improved. This paper presents an active distribution...

  4. Calibration and validation of coarse-grained models of atomic systems: application to semiconductor manufacturing

    Farrell, Kathryn; Oden, J. Tinsley

    2014-07-01

    Coarse-grained models of atomic systems, created by aggregating groups of atoms into molecules to reduce the number of degrees of freedom, have been used for decades in important scientific and technological applications. In recent years, interest in developing a more rigorous theory for coarse graining and in assessing the predictivity of coarse-grained models has arisen. In this work, Bayesian methods for the calibration and validation of coarse-grained models of atomistic systems in thermodynamic equilibrium are developed. For specificity, only configurational models of systems in canonical ensembles are considered. Among major challenges in validating coarse-grained models are (1) the development of validation processes that lead to information essential in establishing confidence in the model's ability predict key quantities of interest and (2), above all, the determination of the coarse-grained model itself; that is, the characterization of the molecular architecture, the choice of interaction potentials and thus parameters, which best fit available data. The all-atom model is treated as the "ground truth," and it provides the basis with respect to which properties of the coarse-grained model are compared. This base all-atom model is characterized by an appropriate statistical mechanics framework in this work by canonical ensembles involving only configurational energies. The all-atom model thus supplies data for Bayesian calibration and validation methods for the molecular model. To address the first challenge, we develop priors based on the maximum entropy principle and likelihood functions based on Gaussian approximations of the uncertainties in the parameter-to-observation error. To address challenge (2), we introduce the notion of model plausibilities as a means for model selection. This methodology provides a powerful approach toward constructing coarse-grained models which are most plausible for given all-atom data. We demonstrate the theory and

  5. The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China

    Ma, Hongbo; Nittrouer, Jeffrey A.; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J.; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

    2017-01-01

    Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams. PMID:28508078

  6. The exceptional sediment load of fine-grained dispersal systems: Example of the Yellow River, China.

    Ma, Hongbo; Nittrouer, Jeffrey A; Naito, Kensuke; Fu, Xudong; Zhang, Yuanfeng; Moodie, Andrew J; Wang, Yuanjian; Wu, Baosheng; Parker, Gary

    2017-05-01

    Sedimentary dispersal systems with fine-grained beds are common, yet the physics of sediment movement within them remains poorly constrained. We analyze sediment transport data for the best-documented, fine-grained river worldwide, the Huanghe (Yellow River) of China, where sediment flux is underpredicted by an order of magnitude according to well-accepted sediment transport relations. Our theoretical framework, bolstered by field observations, demonstrates that the Huanghe tends toward upper-stage plane bed, yielding minimal form drag, thus markedly enhancing sediment transport efficiency. We present a sediment transport formulation applicable to all river systems with silt to coarse-sand beds. This formulation demonstrates a remarkably sensitive dependence on grain size within a certain narrow range and therefore has special relevance to silt-sand fluvial systems, particularly those affected by dams.

  7. The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper

    Buelow, K.; Kristiansson, P.; Schueler, B.; Tullander, E.; Oestling, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

    2002-01-01

    The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission. The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper. The dependence of the penetration depth on the pigment grain size was also studied. To study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used. For the study of the penetration depth dependence of pigment size, specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution. The results show that the calendering of the paper considerably affects the penetration depth of ink

  8. Effects of thermo-mechanical iterations on the grain boundary character distribution of Pb-Ca-Sn-Al alloy

    Wang Weiguo; Guo Hong

    2007-01-01

    Recrystallized Pb-0.05%Ca-1.5%Sn-0.026%Al (mass fraction) alloy, with an averaged grain size of 20-30 μm, special grain boundary (Σ1-Σ29) fraction of less than 40% and the general high angle boundary (HAB) network of fully connected, was subjected to 1-4 cycles of thermo-mechanical processing (TMP) of rolling at ambient temperature followed by annealing at 270 deg. C (0.9T m ). Electron back-scatter diffraction (EBSD) techniques were employed to determine the grain boundary character distribution (GBCD) of the processed samples. The results indicated that 1-, 3- and 4-cycle TMP has very strong but nearly identical effects on the GBCD, the fraction of special boundaries enhanced to 80%, and the connectivity of general high angle boundary (HABs) network is interrupted sufficiently by the so-called special boundaries; However, 2-cycle TMP exerts slight impacts on the GBCD, the fraction of special boundaries is only increased to 59.2% and the connectivity of HABs network is not interrupted substantially. Further discussion pointed out the effects of 1-, 3- and 4-cycle TMP might be attributed to the migration and interactions of incoherent Σ3 (Σ3 ic ) and its variants Σ9 and Σ27 boundaries, while that of 2-cycle TMP may be caused by an enhanced recrystallization

  9. Loss Allocation in a Distribution System with Distributed Generation Units

    Lund, Torsten; Nielsen, Arne Hejde; Sørensen, Poul Ejnar

    2007-01-01

    In Denmark, a large part of the electricity is produced by wind turbines and combined heat and power plants (CHPs). Most of them are connected to the network through distribution systems. This paper presents a new algorithm for allocation of the losses in a distribution system with distributed...... generation. The algorithm is based on a reduced impedance matrix of the network and current injections from loads and production units. With the algorithm, the effect of the covariance between production and consumption can be evaluated. To verify the theoretical results, a model of the distribution system...

  10. Quantum distribution function of nonequilibrium system

    Sogo, Kiyoshi; Fujimoto, Yasushi.

    1990-03-01

    A path integral representation is derived for the Wigner distribution function of a nonequilibrium system coupled with heat bath. Under appropriate conditions, the Wigner distribution function approaches an equilibrium distribution, which manifests shifting and broadening of spectral lines due to the interaction with heat bath. It is shown that the equilibrium distribution becomes the quantum canonical distribution in the vanishing coupling constant limit. (author)

  11. The Planetary Data System Distributed Inventory System

    Hughes, J. Steven; McMahon, Susan K.

    1996-01-01

    The advent of the World Wide Web (Web) and the ability to easily put data repositories on-line has resulted in a proliferation of digital libraries. The heterogeneity of the underlying systems, the autonomy of the individual sites, and distributed nature of the technology has made both interoperability across the sites and the search for resources within a site major research topics. This article will describe a system that addresses both issues using standard Web protocols and meta-data labels to implement an inventory of on-line resources across a group of sites. The success of this system is strongly dependent on the existence of and adherence to a standards architecture that guides the management of meta-data within participating sites.

  12. Energy Management of Smart Distribution Systems

    Ansari, Bananeh

    Electric power distribution systems interface the end-users of electricity with the power grid. Traditional distribution systems are operated in a centralized fashion with the distribution system owner or operator being the only decision maker. The management and control architecture of distribution systems needs to gradually transform to accommodate the emerging smart grid technologies, distributed energy resources, and active electricity end-users or prosumers. The content of this document concerns with developing multi-task multi-objective energy management schemes for: 1) commercial/large residential prosumers, and 2) distribution system operator of a smart distribution system. The first part of this document describes a method of distributed energy management of multiple commercial/ large residential prosumers. These prosumers not only consume electricity, but also generate electricity using their roof-top solar photovoltaics systems. When photovoltaics generation is larger than local consumption, excess electricity will be fed into the distribution system, creating a voltage rise along the feeder. Distribution system operator cannot tolerate a significant voltage rise. ES can help the prosumers manage their electricity exchanges with the distribution system such that minimal voltage fluctuation occurs. The proposed distributed energy management scheme sizes and schedules each prosumer's ES to reduce the electricity bill and mitigate voltage rise along the feeder. The second part of this document focuses on emergency energy management and resilience assessment of a distribution system. The developed emergency energy management system uses available resources and redundancy to restore the distribution system's functionality fully or partially. The success of the restoration maneuver depends on how resilient the distribution system is. Engineering resilience terminology is used to evaluate the resilience of distribution system. The proposed emergency energy

  13. Distribution of trace elements in a modified and grain refined aluminium-silicon hypoeutectic alloy.

    Faraji, M; Katgerman, L

    2010-08-01

    The influence of modifier and grain refiner on the nucleation process of a commercial hypoeutectic Al-Si foundry alloy (A356) was investigated using optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis technique (EPMA). Filtering was used to improve the casting quality; however, it compromised the modification of silicon. Effect of filtering on strontium loss was also studied using the afore-mentioned techniques. EPMA was used to trace the modifying and grain refining agents inside matrix and eutectic Si. This was to help understanding mechanisms of nucleation and modification in this alloy. Using EPMA, the negative interaction of Sr and Al3TiB was closely examined. In modified structure, it was found that the maximum point of Sr concentration was in line with peak of silicon; however, in case of just 0.1wt% added Ti, the peak of Ti concentration was not in line with aluminium, (but it was close to Si peak). Furthermore, EPMA results showed that using filter during casting process lowered the strontium content, although produced a cleaner melt. (c) 2010 Elsevier Ltd. All rights reserved.

  14. Coarse Grained Molecular Dynamics Simulations of Transmembrane Protein-Lipid Systems

    Peter Spijker

    2010-06-01

    Full Text Available Many biological cellular processes occur at the micro- or millisecond time scale. With traditional all-atom molecular modeling techniques it is difficult to investigate the dynamics of long time scales or large systems, such as protein aggregation or activation. Coarse graining (CG can be used to reduce the number of degrees of freedom in such a system, and reduce the computational complexity. In this paper the first version of a coarse grained model for transmembrane proteins is presented. This model differs from other coarse grained protein models due to the introduction of a novel angle potential as well as a hydrogen bonding potential. These new potentials are used to stabilize the backbone. The model has been validated by investigating the adaptation of the hydrophobic mismatch induced by the insertion of WALP-peptides into a lipid membrane, showing that the first step in the adaptation is an increase in the membrane thickness, followed by a tilting of the peptide.

  15. Physical properties of five grain dust types.

    Parnell, C B; Jones, D D; Rutherford, R D; Goforth, K J

    1986-01-01

    Physical properties of grain dust derived from five grain types (soybean, rice, corn, wheat, and sorghum) were measured and reported. The grain dusts were obtained from dust collection systems of terminal grain handling facilities and were assumed to be representative of grain dust generated during the handling process. The physical properties reported were as follows: particle size distributions and surface area measurements using a Coulter Counter Model TAII; percent dust fractions less than 100 micron of whole dust; bulk density; particle density; and ash content. PMID:3709482

  16. Greenhouse Gas Emissions Calculator for Grain and Biofuel Farming Systems

    McSwiney, Claire P.; Bohm, Sven; Grace, Peter R.; Robertson, G. Philip

    2010-01-01

    Opportunities for farmers to participate in greenhouse gas (GHG) credit markets require that growers, students, extension educators, offset aggregators, and other stakeholders understand the impact of agricultural practices on GHG emissions. The Farming Systems Greenhouse Gas Emissions Calculator, a web-based tool linked to the SOCRATES soil…

  17. Grain size distribution, clay mineralogy and chemistry of bottom sediments from the outer Thermaikos Gulf, Aegean Sea, Greece

    K.G. PEHLIVANOGLOU

    2004-06-01

    Full Text Available The Thermaikos Gulf constitutes the NW part of the North Aegean Sea and is limited eastward from the Chalkidiki Peninsula and westward from the Pieria Prefecture. Its plateau covers an area of 3,500 km2. The mechanisms responsible for the grain size distribution into the Gulf, the clay mineralogy and the chemistry of some bottom sediments from the outer Thermaikos Gulf, are examined. Source mixing during transportation, flocculation, differential settling processes and organic matter appear to be the main mechanisms for the distribution of clay minerals in shallow waters. All grain size fractions studied present a wide range of values confirming the extreme variations of the discharged load and the variability in marine processes. Plagioclases predominate over K-feldspars, while quartz is the most abundant mineral present. In addition, micas, chlorites, amphiboles and pyroxenes exist as primary and/or accessory minerals in all samples. Among clay minerals, illite predominates over smectite and smectite over chlorite (+ kaolinite. The ordered interstratified phase of I/S, with 30-35% S layers, is present in the 2-0.25µm fraction. The randomly interstratified phase of I/S, with 50% S layers, is present in the <0.25& micro; m fraction. On average the clay mineral content of the studied samples is: 48% I, 23% S, 17% Ch (+K and 12% others for the 2-0.25µm fraction and 50% I, 30% S and 20% Ch (+K for the <0.25 µm fraction. All these minerals are the weathering products of the rocks from the drainage basins of the rivers flowing into the Gulf, as well as of the Neogene and Quaternary unconsolidated sediments of the surrounding coasts. The terrigenous input, the water mass circulation and, to a lesser extent, the quality of the discharged material and the differential settling of grains, control the grain size distribution within the outer Thermaikos Gulf. The chemical composition of the analysed samples is generally in agreement with their mineral

  18. A prototype sensor system for the early detection of microbially linked spoilage in stored wheat grain

    de Lacy Costello, B. P. J.; Ewen, R. J.; Gunson, H.; Ratcliffe, N. M.; Sivanand, P. S.; Spencer-Phillips, P. T. N.

    2003-04-01

    Sensors based on composites of metal oxides were fabricated and tested extensively under high-humidity and high-flow conditions with exposure to vapours reported to increase in the headspace of wheat grain (Triticum aestivum cv Hereward) colonized by fungi. The sensors that exhibited high sensitivity to target vapours combined with high stability were selected for inclusion into a four-sensor array prototype system. A sampling protocol aligned to parallel gas chromatography-mass spectrometry and human olfactory assessment studies was established for use with the sensor system. The sensor system was utilized to assess irradiated wheat samples that had been conditioned to 25% moisture content and inoculated with pathogens known to cause spoilage of grain in storage. These included the fungi Penicillium aurantiogriseum, Penicillium vulpinum, Penicillium verrucosum, Fusarium culmorum, Aspergillus niger, and Aspergillus flavus and the actinomycete, Streptomyces griseus. The sensor system successfully tracked the progress of the infections from a very early stage and the results were compared with human olfactory assessment panels run concurrently. A series of dilution studies were undertaken using previously infected grain mixed with sound grain, to improve the sensitivity and maximize the differentiation of the sensor system. An optimum set of conditions including incubation temperature, incubation time, sampling time, and flow rate were ascertained utilizing this method. The sensor system differentiated samples of sound grain from samples of sound grain with 1% (w/w) fungus infected grain added. Following laboratory trials, the prototype sensor system was evaluated in a commercial wheat grain intake facility. Thresholds calculated from laboratory tests were used to differentiate between sound and infected samples (classified by intake laboratory technicians) collected routinely from trucks delivering grain for use in food manufacture. All samples identified as having

  19. The Barley Grain Thioredoxin System – an Update

    Per eHägglund

    2013-05-01

    Full Text Available Thioredoxin reduces disulfide bonds and play numerous important functions in plants. In cereal seeds, cytosolic h-type thioredoxin facilitates the release of energy reserves during the germination process and is recycled by NADPH-dependent thioredoxin reductase. This review presents a summary of the research conducted during the last ten years to elucidate the structure and function of the barley seed thioredoxin system at the molecular level combined with proteomic approaches to identify target proteins.

  20. A new database sub-system for grain-size analysis

    Suckow, Axel

    2013-04-01

    Detailed grain-size analyses of large depth profiles for palaeoclimate studies create large amounts of data. For instance (Novothny et al., 2011) presented a depth profile of grain-size analyses with 2 cm resolution and a total depth of more than 15 m, where each sample was measured with 5 repetitions on a Beckman Coulter LS13320 with 116 channels. This adds up to a total of more than four million numbers. Such amounts of data are not easily post-processed by spreadsheets or standard software; also MS Access databases would face serious performance problems. The poster describes a database sub-system dedicated to grain-size analyses. It expands the LabData database and laboratory management system published by Suckow and Dumke (2001). This compatibility with a very flexible database system provides ease to import the grain-size data, as well as the overall infrastructure of also storing geographic context and the ability to organize content like comprising several samples into one set or project. It also allows easy export and direct plot generation of final data in MS Excel. The sub-system allows automated import of raw data from the Beckman Coulter LS13320 Laser Diffraction Particle Size Analyzer. During post processing MS Excel is used as a data display, but no number crunching is implemented in Excel. Raw grain size spectra can be exported and controlled as Number- Surface- and Volume-fractions, while single spectra can be locked for further post-processing. From the spectra the usual statistical values (i.e. mean, median) can be computed as well as fractions larger than a grain size, smaller than a grain size, fractions between any two grain sizes or any ratio of such values. These deduced values can be easily exported into Excel for one or more depth profiles. However, such a reprocessing for large amounts of data also allows new display possibilities: normally depth profiles of grain-size data are displayed only with summarized parameters like the clay

  1. Method of Relating Grain Size Distribution to Hydraulic Conductivity in Dune Sands to Assist in Assessing Managed Aquifer Recharge Projects: Wadi Khulays Dune Field, Western Saudi Arabia

    Oliver M. Lopez

    2015-11-01

    Full Text Available Planning for use of a dune field aquifer for managed aquifer recharge (MAR requires that hydraulic properties need to be estimated over a large geographic area. Saturated hydraulic conductivity of dune sands is commonly estimated from grain size distribution data by employing some type of empirical equation. Over 50 samples from the Wadi Khulays dune field in Western Saudi Arabia were collected and the grain size distribution, porosity, and hydraulic conductivity were measured. An evaluation of 20 existing empirical equations showed a generally high degree of error in the predicted compared to the measured hydraulic conductivity values of these samples. Statistical analyses comparing estimated versus measured hydraulic conductivity demonstrated that there is a significant relationship between hydraulic conductivity and mud percentage (and skewness. The modified Beyer equation, which showed a generally low prediction error, was modified by adding a second term fitting parameter related to the mud concentration based on 25 of the 50 samples analyzed. An inverse optimization process was conducted to quantify the fitting parameter and a new empirical equation was developed. This equation was tested against the remaining 25 samples analyzed and produced an estimated saturated hydraulic conductivity with the lowest error of any empirical equation. This methodology can be used for large dune field hydraulic conductivity estimation and reduce planning costs for MAR systems.

  2. Method of Relating Grain Size Distribution to Hydraulic Conductivity in Dune Sands to Assist in Assessing Managed Aquifer Recharge Projects: Wadi Khulays Dune Field, Western Saudi Arabia

    Lopez Valencia, Oliver Miguel

    2015-11-12

    Planning for use of a dune field aquifer for managed aquifer recharge (MAR) requires that hydraulic properties need to be estimated over a large geographic area. Saturated hydraulic conductivity of dune sands is commonly estimated from grain size distribution data by employing some type of empirical equation. Over 50 samples from the Wadi Khulays dune field in Western Saudi Arabia were collected and the grain size distribution, porosity, and hydraulic conductivity were measured. An evaluation of 20 existing empirical equations showed a generally high degree of error in the predicted compared to the measured hydraulic conductivity values of these samples. Statistical analyses comparing estimated versus measured hydraulic conductivity demonstrated that there is a significant relationship between hydraulic conductivity and mud percentage (and skewness). The modified Beyer equation, which showed a generally low prediction error, was modified by adding a second term fitting parameter related to the mud concentration based on 25 of the 50 samples analyzed. An inverse optimization process was conducted to quantify the fitting parameter and a new empirical equation was developed. This equation was tested against the remaining 25 samples analyzed and produced an estimated saturated hydraulic conductivity with the lowest error of any empirical equation. This methodology can be used for large dune field hydraulic conductivity estimation and reduce planning costs for MAR systems.

  3. Predictive modelling of grain size distributions from marine electromagnetic profiling data using end-member analysis and a radial basis function network

    Baasch, B.; M"uller, H.; von Dobeneck, T.

    2018-04-01

    In this work we present a new methodology to predict grain-size distributions from geophysical data. Specifically, electric conductivity and magnetic susceptibility of seafloor sediments recovered from electromagnetic profiling data are used to predict grain-size distributions along shelf-wide survey lines. Field data from the NW Iberian shelf are investigated and reveal a strong relation between the electromagnetic properties and grain-size distribution. The here presented workflow combines unsupervised and supervised machine learning techniques. Nonnegative matrix factorisation is used to determine grain-size end-members from sediment surface samples. Four end-members were found which well represent the variety of sediments in the study area. A radial-basis function network modified for prediction of compositional data is then used to estimate the abundances of these end-members from the electromagnetic properties. The end-members together with their predicted abundances are finally back transformed to grain-size distributions. A minimum spatial variation constraint is implemented in the training of the network to avoid overfitting and to respect the spatial distribution of sediment patterns. The predicted models are tested via leave-one-out cross-validation revealing high prediction accuracy with coefficients of determination (R2) between 0.76 and 0.89. The predicted grain-size distributions represent the well-known sediment facies and patterns on the NW Iberian shelf and provide new insights into their distribution, transition and dynamics. This study suggests that electromagnetic benthic profiling in combination with machine learning techniques is a powerful tool to estimate grain-size distribution of marine sediments.

  4. The origin of dose distributions in fluvial sediments, and the prospect of dating single grains from fluvial deposits using optically stimulated luminescence

    Olley, J.M.; Caitcheon, G.G.; Roberts, R.G.

    1999-01-01

    We examine the causes of the asymmetric distributions of dose observed from measurements of the optically stimulated luminescence emitted by small aliquots of fluvial quartz, and deduce that the asymmetry arises as a result of samples being composed of a mix of mainly well bleached grains with grains that were effectively unbleached at the time of deposition. We demonstrate that the shapes of the dose distributions can be used to assess the likelihood that aliquots consist only of grains that were well-bleached at the time of deposition. The more asymmetric the distribution, the greater the probability that the aliquots with the lowest dose most closely represent the true burial dose. Single grains with differing doses are present in each of the samples examined, and the population with the lowest dose gives an optical age consistent with the expected burial age. This result implies that the beta-dose heterogeneity in these deposits is small, and that the effects of micro-dosimetric variations on optical dating of individual grains are not significant for these samples. We demonstrate that single-grain dating of fluvial material is possible and practicable using standard Risoe optical dating equipment, and we conclude that application of a new regenerative-dose protocol to single grains of quartz, using the lowest dose population to estimate the burial dose, is the best available means of obtaining reliable luminescence ages for heterogeneously bleached fluvial sediments

  5. The Impact of Connecting Distributed Generation to the Distribution System

    E. V. Mgaya

    2007-01-01

    Full Text Available This paper deals with the general problem of utilizing of renewable energy sources to generate electric energy. Recent advances in renewable energy power generation technologies, e.g., wind and photovoltaic (PV technologies, have led to increased interest in the application of these generation devices as distributed generation (DG units. This paper presents the results of an investigation into possible improvements in the system voltage profile and reduction of system losses when adding wind power DG (wind-DG to a distribution system. Simulation results are given for a case study, and these show that properly sized wind DGs, placed at carefully selected sites near key distribution substations, could be very effective in improving the distribution system voltage profile and reducing power losses, and hence could  improve the effective capacity of the system

  6. Control and operation of distributed generation in distribution systems

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2011-01-01

    Many distribution systems nowadays have significant penetration of distributed generation (DG)and thus, islanding operation of these distribution systems is becoming a viable option for economical and technical reasons. The DG should operate optimally during both grid-connected and island...... algorithm, which uses average rate of change off requency (Af5) and real power shift RPS), in the islanded mode. RPS will increase or decrease the power set point of the generator with increasing or decreasing system frequency, respectively. Simulation results show that the proposed method can operate...

  7. Development of a red TL detection system for a single grain of quartz

    Yawata, T.; Hashimoto, T.

    2007-01-01

    Red thermoluminescence (RTL) of natural quartz grains offers many desirable properties for quaternary chronology and archaeological dating, although RTL measurements suffer from high thermal background due to black-body radiation on heating. To reduce the thermal background to as low a level as possible, a silver sample disc covered with a biotite plate with a sample hole was used in combination with a light guide, cluster heater, optical filters, and photomultiplier tube cooling to -20 deg. C in the present system. As a result, the thermal background decreased from 2x10 4 to 1000 cps in the temperature range 350-380 deg. C, resulting in a detection limit of approximately 100 cps, corresponding to the RTL signal from a single quartz grain (250-500μm) irradiated with 4.0 Gy. In addition, application of lower heating rates retarded the thermal quenching effect, resulting in high RTL signals, which are preferable for young or insensitive quartz samples. Using RTL measurements with the single quartz grain method under optimal RTL conditions, comparison of equivalent doses from artificially irradiated single quartz grains to the known dose was within the 20% measurement error. Based on equivalent dose determinations for single quartz grains, large irregularities on non-etched quartz surfaces might be very detrimental to the TL detection process. This result confirms that surface etching treatment is required to achieve reliable dating with high counting efficiency

  8. Soil water infiltration affected by biofuel and grain crop production systems in claypan landscape

    The effect of soil management systems on water infiltration is very crucial within claypan landscapes to maximize production as well as minimize environmental risks. The objective of this study was to assess the effect of topsoil thickness on water infiltration in claypan soils for grain and biofuel...

  9. [The status of the body protective systems in children in atmospheric pollution by grain dust].

    Mukhambetova, L Kh; Petrova, I V; Pinigin, M A; Leshchenko, G M; Shekhter, O V; Safiulin, A A; Astakhova, L F

    1998-01-01

    The use of noninvasive methods has revealed changes in the detoxification and immune systems in children exposed to grain dust-polluted ambient air. Impaired detoxification and immunity may be considered to be a manifestation of the common pathological mechanism responsible for reduced resistance to adverse factors and they lead to the increased risk of nonspecific infectious processes and allergy in the population.

  10. The effect of some growth regulators on enzyme systems in irradiated barley grain using disinfestation doses

    Bachman, S.

    1973-01-01

    Disinfestation doses of 20 to 100 krad may cause changes in the biological systems of barley grain and, therefore, may influence undesirably the technological quality of malted grain. The effect of some growth regulators on irradiated grain has been investigated. The experiments have been carried out on brewery barley var. Visa Breuns. Following growth-regulators were used: gibberellic acid (Polish preparation ''Gibrescol''), kinetin (6-furfurylo-aminopurin), CCC (2-chloroethyl trimethyl ammonium chloride), and betaine hydrochloride. By treating the irradiated barley with solutions of growth regulators it was possible to diminish the loss of enzyme activity. A ''regenerating'' effect of growth substances, mainly gibberellic acid and betain hydrochloride in 10 -4 M solutions, was observed. Amylolytic activity decreased immediately after irradiation but in samples treated with growth regulators it was higher than in those without regulators. The results may have a practical importance since gibberellic acid has just been introduced into the brewery industry. (F.J.)

  11. Grain-size distribution of surface sediments of climbing and falling ...

    45

    The climbing and falling dunes distributing in the wide valleys of China's Yarlung. 64. Zangbo River ...... Food and Agriculture Organization (FAO). 2006. The state of ... Global land use change, economic globalization, and. 450 the looming ...

  12. Islanding Operation of Distribution System with Distributed Generations

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2010-01-01

    The growing interest in distributed generations (DGs) due to environmental concern and various other reasons have resulted in significant penetration of DGs in many distribution system worldwide. DGs come with many benefits. One of the benefits is improved reliability by supplying load during power...

  13. Low jitter RF distribution system

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

    A timing signal distribution system includes an optical frequency stabilized laser signal amplitude modulated at an rf frequency. A transmitter box transmits a first portion of the laser signal and receive a modified optical signal, and outputs a second portion of the laser signal and a portion of the modified optical signal. A first optical fiber carries the first laser signal portion and the modified optical signal, and a second optical fiber carries the second portion of the laser signal and the returned modified optical signal. A receiver box receives the first laser signal portion, shifts the frequency of the first laser signal portion outputs the modified optical signal, and outputs an electrical signal on the basis of the laser signal. A detector at the end of the second optical fiber outputs a signal based on the modified optical signal. An optical delay sensing circuit outputs a data signal based on the detected modified optical signal. An rf phase detect and correct signal circuit outputs a signal corresponding to a phase stabilized rf signal based on the data signal and the frequency received from the receiver box.

  14. Effects of arbuscular mycorrhizal fungi inoculation on carbon and nitrogen distribution and grain yield and nutritional quality in rice (Oryza sativa L.).

    Zhang, Xue; Wang, Li; Ma, Fang; Yang, Jixian; Su, Meng

    2017-07-01

    The importance of arbuscular mycorrhizal fungi (AMF) for nutrient uptake and growth in rice has been widely recognized. However, little is known about the distribution of carbon (C) and nitrogen (N) in rice under AMF inoculation, which can affect grain yield and quality. This study was conducted to investigate the distribution of C and N within rice plants under AMF inoculation and the effects on grain yield and quality. AMF inoculation significantly increased N accumulation and distribution in vegetative tissues at tillering, and N translocation into seeds from heading to maturity. Consequently, AMF inoculation more strongly impacted the distribution of N than that of C in seeds, with significantly reduced C:N ratios and increased protein content (by 7.4%). Additionally, AMF inoculation significantly increased grain yield by 28.2% through increasing the grain:straw ratio by 18.4%. In addition, the roots of inoculated rice exhibited greater change in C distribution, with significantly higher C concentrations, C accumulations, and C:N ratios at tillering and maturity. AMF inoculation affected the distribution of N in seeds and C in roots. As such, AMF inoculation may be a potential method for improving grain yield and quality. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Grain size distribution of road-deposited sediment and its contribution to heavy metal pollution in urban runoff in Beijing, China.

    Zhao, Hongtao; Li, Xuyong; Wang, Xiaomei; Tian, Di

    2010-11-15

    Pollutant washoff from road-deposited sediment (RDS) is an increasing problem associated with the rapid urbanization of China that results in urban non-point source pollution. Here, we analyzed the RDS grain size distribution and its potential impact on heavy metal pollution in urban runoff from impervious surfaces of urban villages, colleges and residences, and main traffic roads in the Haidian District, Beijing, China. RDS with smaller grain size had a higher metal concentration. Specifically, particles with the smallest grain size (runoff water accounted for greater than 70% of the metal mass in the total suspended solids (TSS). The heavy metal content in the TSS was 2.21-6.52% of that in the RDS. These findings will facilitate our understanding of the importance of RDS grain size distribution in heavy metal pollution caused by urban storm runoff. Copyright © 2010 Elsevier B.V. All rights reserved.

  16. Autoradiographic study on moisture distribution in pearl-barley and in rice grain

    Sakharov, Eh.V.; Koz'mina, E.P.; Troitskaya, E.Ya

    1975-01-01

    The dependence of some structural details of the pearl-barley and rice endosperm on the internal moisture distribution is found. The general scheme of the study is shown. The curves of the local moisture distribution in the pearly-barley and rice kernel are plotted according to the radiography data. Moisture distribution over the whole section of the rice kernel is relatively constant at 85 deg C after ten minutes of moisture. Whereas moisture of pearl-barley kernel is only approaching the center of kernel by the time the moisture content increases to 1.5-2%. The slow moisture transfer in the pearl-barley kernel makes the cooking period three times longer as that of the rice

  17. RELIABILITY ANALYSIS OF POWER DISTRIBUTION SYSTEMS

    Popescu V.S.

    2012-04-01

    Full Text Available Power distribution systems are basic parts of power systems and reliability of these systems at present is a key issue for power engineering development and requires special attention. Operation of distribution systems is accompanied by a number of factors that produce random data a large number of unplanned interruptions. Research has shown that the predominant factors that have a significant influence on the reliability of distribution systems are: weather conditions (39.7%, defects in equipment(25% and unknown random factors (20.1%. In the article is studied the influence of random behavior and are presented estimations of reliability of predominantly rural electrical distribution systems.

  18. Review on Islanding Operation of Distribution System with Distributed Generation

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2011-01-01

    The growing environmental concern and various benefits of distributed generation (DG) have resulted in significant penetration of DG in many distribution systems worldwide. One of the major expected benefits of DG is the improvement in the reliability of power supply by supplying load during power...... outage by operating in an island mode. However, there are many challenges to overcome before islanding operation of a distribution system with DG can become a viable solution in future. This paper reviews some of the major challenges with islanding operation and explores some possible solutions...

  19. Development of low angle grain boundaries in lightly deformed superconducting niobium and their influence on hydride distribution and flux perturbation

    Sung, Z.-H.; Wang, M.; Polyanskii, A. A.; Santosh, C.; Balachandran, S.; Compton, C.; Larbalestier, D. C.; Bieler, T. R.; Lee, P. J.

    2017-05-01

    This study shows that low angle grain boundaries (LAGBs) can be created by small 5% strains in high purity (residual resistivity ratio ≥ 200) superconducting radio frequency (SRF)-grade single crystalline niobium (Nb) and that these boundaries act as hydrogen traps as indicated by the distribution of niobium hydrides (Nb1-xHx). Nb1-xHx is detrimental to SRF Nb cavities due to its normal conducting properties at cavity operating temperatures. By designing a single crystal tensile sample extracted from a large grain (>5 cm) Nb ingot slice for preferred slip on one slip plane, LAGBs and dense dislocation boundaries developed. With chemical surface treatments following standard SRF cavity fabrication practice, Nb1-xHx phases were densely precipitated at the LAGBs upon cryogenic cooling (8-10 K/min). Micro-crystallographic analysis confirmed heterogeneous hydride precipitation, which included significant hydrogen atom accumulation in LAGBs. Magneto-optical imaging analysis showed that these sites can then act as sites for both premature flux penetration and eventually flux trapping. However, this hydrogen related degradation at LAGBs did not completely disappear even after an 800 °C/2 h anneal typically used for hydrogen removal in SRF Nb cavities. These findings suggest that hydride precipitation at an LAGB is facilitated by a non-equilibrium concentration of vacancy-hydrogen (H) complexes aided by mechanical deformation and the hydride phase interferes with the recovery process under 800 °C annealing.

  20. Distributed radiation protection console system

    Chhokra, R.S.; Deshpande, V.K.; Mishra, H.; Rajeev, K.P.; Thakur, Bipla B.; Munj, Niket

    2004-01-01

    Radiation exposure control is one of the most important aspects in any nuclear facility . It encompasses continuous monitoring of the various areas of the facility to detect any increase in the radiation level and/or the air activity level beyond preset limits and alarm the O and M personnel working in these areas. Detection and measurement of radiation level and the air activity level is carried out by a number of monitors installed in the areas. These monitors include Area Gamma Monitors, Continuous Air Monitors, Pu-In-Air Monitors, Criticality Monitors etc. Traditionally, these measurements are displayed and recorded on a Central Radiation Protection Console(CRPC), which is located in the central control room of the facility. This methodology suffers from the shortcoming that any worker required to enter a work area will have to inquire about the radiation status of the area either from the CRPC or will get to know the same directly from the installed only after entering the area. This shortcoming can lead to avoidable delays in attending to the work or to unwanted exposure. The authors have designed and developed a system called Distributed Radiation Protection Console (DRPC) to overcome this shortcoming. A DRPC is a console which is located outside the entrance of a given area and displays the radiation status of the area. It presents to health physicist and the plant operators a graphic over-view of the radiation and air activity levels in the particular area of the plant. It also provides audio visual annunciation of the alarm status. Each radioactive area in a nuclear facility will have its own DRPC, which will receive as its inputs the analog and digital signals from radiation monitoring instruments installed in the area and would not only show those readings on its video graphic screen but will also provide warning messages and instructions to the personnel entering the active areas. The various DRPCs can be integrated into a Local Area Network, where the

  1. Grain size distribution and annual variation along the beaches from Poompuhar to Nagoor, Tamilnadu, India

    Chandrasekaran, R.; Angusamy, N.; Manickaraj, D.S.; Loveson, V.J.; Gujar, A.R.; Chandrasekar, N.; Rajamanickam, G.V.

    , G.M. (1967) Dynamic Processes and Statistical parameters compared for size frequency distribution of beach river sands. Jour. Sed. Petrol,V.37, pp.327-354. Rajamanickam, G.V. and Gujar, A.R. (1984) Sediment depositional environment in some...

  2. Control and Operation of Islanded Distribution System

    Mahat, Pukar

    deviation and real power shift. When a distribution system, with all its generators operating at maximum power, is islanded, the frequency will go down if the total load is more than the total generation. An under-frequency load shedding procedure for islanded distribution systems with DG unit(s) based...... states. Short circuit power also changes when some of the generators in the distribution system are disconnected. This may result in elongation of fault clearing time and hence disconnection of equipments (including generators) in the distribution system or unnecessary operation of protective devices...... operational challenges. But, on the other hand, it has also opened up some opportunities. One opportunity/challenge is an islanded operation of a distribution system with DG unit(s). Islanding is a situation in which a distribution system becomes electrically isolated from the remainder of the power system...

  3. DIAMONDS: Engineering Distributed Object Systems

    Cheng, Evan

    1997-01-01

    This report describes DIAMONDS, a research project at Syracuse University, that is dedicated to producing both a methodology and corresponding tools to assist in the development of heterogeneous distributed software...

  4. Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil.

    Barreto, Cintia F; Vilela, Claudia G; Baptista-Neto, José A; Barth, Ortrud M

    2012-09-01

    Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.

  5. Determination of air movement in stored grain as a factor in dynamic dispersion and distribution patterns of gaseous pesticides (fumigants).

    Berck, B

    1975-05-01

    The new research reported herein was motivated by variations in distribution-persistence patterns of fumigant residues (BERCK, 1974). The current developmental program is still underway. In the meantime, measurement of picoliter amounts of SF6 in air by GC equipped with a Ni63 EC detector has been proven useful over an airflow range of 10(-4) to 50 mph, representing a factor of 500,000 in differences in air velocity. Diverse applications have been outlined herein. This is the first case on record where measurement of unassisted airflow in the interstitial air of stored grain has been successfully executed, and which enabled determination of airflow speeds in the range of 0.5 to 7.5 times 10(-4) mph (=3 to 45 inches per hour).

  6. Renormalization of boundary conditions for distribution functions of quasiparticles obeying quantum statistics at interfaces between crystalline grains

    Grendel, M.

    1981-01-01

    Boundary conditions for distribution functions of quasiparticles scattered by an interface between two crystalline grains are presented. Contrary to former formulations where Maxwell-Boltzmann statistics was considered, the present boundary conditions take into account the quantum statistics (Fermi-Dirac or Bose-Einstein) of quasiparticles. Provided that small deviations only from thermodynamic equilibrium are present, the boundary conditions are linearized, and then their ''renormalization'' is investigated in case of elastic scattering. The final results of the renormalization, which are obtained for a simplified model of an interface, sugo.est that the portion of the Fermi (Bose)-quasiparticles reflected or transmitted specularly is decreased (increased) in comparison with the case of quasiparticles obeying Maxwell-Boltzmann statistics. (author)

  7. Water sample-collection and distribution system

    Brooks, R. R.

    1978-01-01

    Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

  8. Starch granules size distribution in superior and inferior grains of wheat is related to enzyme activities and their gene expressions during grain filling

    Zhang, Chuanhui; Jiang, Dong; Liu, Fulai

    2010-01-01

    with the temporally change patterns of starch synthase activities and relative gene expression levels. For instance, activities of soluble and granule-bound starch synthases (designated SSS and GBSS) peaked at 20 and 24 DAF. Genes encoding isoforms of starch synthases expressed at different grain filling periods...

  9. The ATLAS distributed analysis system

    Legger, F.

    2014-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During...

  10. Research in Distributed Real-Time Systems

    Mukkamala, R.

    1997-01-01

    This document summarizes the progress we have made on our study of issues concerning the schedulability of real-time systems. Our study has produced several results in the scalability issues of distributed real-time systems. In particular, we have used our techniques to resolve schedulability issues in distributed systems with end-to-end requirements. During the next year (1997-98), we propose to extend the current work to address the modeling and workload characterization issues in distributed real-time systems. In particular, we propose to investigate the effect of different workload models and component models on the design and the subsequent performance of distributed real-time systems.

  11. Innovative biological systems for anaerobic treatment of grain and food processing wastewaters

    Sutton, P M

    1986-09-01

    The application of two innovative fixed film and suspended growth anaerobic biological systems to the treatment of grain and food processing wastewaters is discussed. A fluidized bed fixed film system and a suspended growth membrane system are described. The technical and economic factors dictating which system is selected for treatment of a specific industrial wastewater are discussed. Case history results from successful operation of full-scale, demonstration, and pilot-scale systems treating respectively, soy whey, cheese whey, and wheat flour processing wastewaters are presented.

  12. Quantitative Phase-Field Approach for Simulating Grain Growth in Anisotropic Systems with Arbitrary Inclination and Misorientation Dependence

    Moelans, N.; Blanpain, B.; Wollants, P.

    2008-01-01

    A phase-field approach for quantitative simulations of grain growth in anisotropic systems is introduced, together with a new methodology to derive appropriate model parameters that reproduce given misorientation and inclination dependent grain boundary energy and mobility in the simulations. The proposed model formulation and parameter choice guarantee a constant diffuse interface width and consequently give high controllability of the accuracy in grain growth simulations

  13. On Distributed Port-Hamiltonian Process Systems

    Lopezlena, Ricardo; Scherpen, Jacquelien M.A.

    2004-01-01

    In this paper we use the term distributed port-Hamiltonian Process Systems (DPHPS) to refer to the result of merging the theory of distributed Port-Hamiltonian systems (DPHS) with the theory of process systems (PS). Such concept is useful for combining the systematic interconnection of PHS with the

  14. Distributed Cognition and Distributed Morality: Agency, Artifacts and Systems.

    Heersmink, Richard

    2017-04-01

    There are various philosophical approaches and theories describing the intimate relation people have to artifacts. In this paper, I explore the relation between two such theories, namely distributed cognition and distributed morality theory. I point out a number of similarities and differences in these views regarding the ontological status they attribute to artifacts and the larger systems they are part of. Having evaluated and compared these views, I continue by focussing on the way cognitive artifacts are used in moral practice. I specifically conceptualise how such artifacts (a) scaffold and extend moral reasoning and decision-making processes, (b) have a certain moral status which is contingent on their cognitive status, and (c) whether responsibility can be attributed to distributed systems. This paper is primarily written for those interested in the intersection of cognitive and moral theory as it relates to artifacts, but also for those independently interested in philosophical debates in extended and distributed cognition and ethics of (cognitive) technology.

  15. Effect of Ion Streaming on Diffusion of Dust Grains in Dissipative System

    Begum, M.; Das, N.

    2018-01-01

    The presence of strong electric fields in the sheath region of laboratory complex plasma induces an ion drift and perturbs the field around dust grains. The downstream focusing of ions leads to the formation of oscillatory kind of attractive wake potential which superimpose with the normal Debye-Hückel (DH) potential. The structural properties of complex plasma and diffusion coefficient of dust grains in the presence of such a wake potential have been investigated using Langevin dynamics simulation in the subsonic regime of ion flow. The study reveals that the diffusion of dust grains is strongly affected by the ion flow, so that the diffusion changes its character in the wake potential to the DH potential dominant regimes. The dependence of the diffusion coefficient on the parameters, such as the neutral pressure, dust grain size, ion flow velocity, and Coulomb coupling parameter, have been calculated for the subsonic regime by using the Green-Kubo expression, which is based on the integrated velocity autocorrelation function. It is found that the diffusion and the structural property of the system is intimately connected with the interaction potential and significantly get affected in the presence of ion flow in the subsonic regime.

  16. Corn yield for silage and grains in different integrated crop-livestock systems

    Laíse da Silveira Pontes

    Full Text Available Abstract In this study, the objective was to assess the influence of two doses of N (90 and 180 kg N ha-1, added to the winter pastures, two integrated crop-livestock systems (ICLS, with and without trees and five positions between the tree rows, on the corn (Zea mays L. quality and productivity, for silage and grain. Adopting the complete randomized block design, the treatments included three replicates. In 2006, following the 14 x 3 m spacing (currently with 158 trees ha-1 the trees were planted in 6 out of the 12 paddocks. While the corn was implemented during summer of 2013/2014, cattle grazing on the annual pasture was done during the prior winter, in both ICLS. Corn for silage was reaped at the R5 phenological stage, whereas for grains it was done at 176 days post seeding. For silage, the corn plants were grinded and then stocked in the experimental mini PVC silos. The silage varied slightly in quality along the positions between the tree rows. The differences observed between N levels in the dry matter, crude protein (CP and grain productivity are expressions of the residual effects of the winter fertilization. Silage quality was improved by the shade effect which minimized the acid detergent fiber and raised the CP, although it reduced the corn production for silage and grains by 52%. Some feasible techniques to reduce these losses are discussed.

  17. Applying Distributed Object Technology to Distributed Embedded Control Systems

    Jørgensen, Bo Nørregaard; Dalgaard, Lars

    2012-01-01

    In this paper, we describe our Java RMI inspired Object Request Broker architecture MicroRMI for use with networked embedded devices. MicroRMI relieves the software developer from the tedious and error-prone job of writing communication protocols for interacting with such embedded devices. MicroR...... in developing control systems for distributed embedded platforms possessing severe resource restrictions.......RMI supports easy integration of high-level application specific control logic with low-level device specific control logic. Our experience from applying MicroRMI in the context of a distributed robotics control application, clearly demonstrates that it is feasible to use distributed object technology...

  18. Thermal Distribution System | Energy Systems Integration Facility | NREL

    Thermal Distribution System Thermal Distribution System The Energy Systems Integration Facility's . Photo of the roof of the Energy Systems Integration Facility. The thermal distribution bus allows low as 10% of its full load level). The 60-ton chiller cools water with continuous thermal control

  19. Producing laminated NiAl with bimodal distribution of grain size by solid–liquid reaction treatment

    Fan, G.H.; Wang, Q.W.; Du, Y.

    2014-01-01

    The prospect of combining laminated structure design and grain size tailoring to toughen brittle materials is examined. Laminated NiAl consisting of coarse-grained layers and fine-grained layers was fabricated by solid–liquid reaction treatment of stacking Ni and Al foils. The fracture toughness...

  20. Distributed systems for protecting nuclear power stations

    Jover, P.

    1980-05-01

    The advantages of distributed control systems for the control of nuclear power stations are obviously of great interest. Some years ago, EPRI, (Electric Power Research Institute) showed that multiplexing the signals is technically feasible, that it enables the availability specifications to be met and costs to be reduced. Since then, many distributed control systems have been proposed by the manufacturers. This note offers some comments on the application of the distribution concept to protection systems -what should be distributed- and ends with a brief description of a protection system based on microprocessors for the pressurized power stations now being built in France [fr

  1. Shade Trees Spatial Distribution and Its Effect on Grains and Beverage Quality of Shaded Coffee Trees

    Francisco José da Silva Neto

    2018-01-01

    Full Text Available Shading coffee trees has gained importance, especially among smallholders, as an option to improve the products’ quality, therefore acquiring place at the specialty coffee market, where consumers are willing to give bonus for quality. This work aims to evaluate the influence of shade trees’ spatial distribution among coffee trees’ agronomic characteristics, yield, and beans and cup quality of shaded coffee trees. The experimental design consisted of completely randomized blocks with six repetitions and four treatments: coffee trees on shade trees planting rows, distant one meter from the trunk; coffee trees on shade trees planting row, distant six meters from the trunk; and coffee plants between the rows of shade trees, parallel to the previous treatments. The parameters analyzed were plant height, canopy diameter, plagiotropic branches’ length, yield, coffee fruits’ phenological stage, ripe cherries’ Brix degree, percentage of black, unripe, and insect damaged beans, bean size, and beverage quality. Shade trees quickened coffee fruits’ phenological stage of coffee trees nearest to them. This point also showed the best beverage quality, except for overripe fruits. The remaining parameters evaluated were not affected by shade trees’ spatial distribution.

  2. MORPHOMETRIC CHARACTERIZATION OF THE SAND FRACTION IN A SAND GRAIN IMAGE CAPTURE SYSTEM1

    Lucimar Arruda Viana

    Full Text Available ABSTRACT Morphology studies assume significant importance in analysis of phenomena of granular systems packaging, in particular with a view to the use of the technique of soil stabilization named particle size correction in forest roads. In this context, this study aimed to develop and operationalize a Sand Grain Image Capture System and, hereby, determine the morphological indices of the sand fractions of two sandy soils called João Pinheiro (JP and Cachoeira da Prata (CP. Soil samples, air-dried, were sieved (2.0 mm nominal mesh size for removal of gravels. The materials that passed through the sieve were subjected to dispersion, washing in 0.053 mm nominal mesh size sieve, removal of organic matter and iron oxides to obtain the clean sand fractions. Subsequently, each soil sample was sieved for separation into twelve classes, between the diameters of 0.149 mm and 1.190 mm, using a Rotap shaker. Next, tests were carried out to characterize the morphometric attributes of the twelve classes of sand fractions of the soils studied. For validation of the performance of the Sand Grain Image Capture System, the results were compared to those obtained using a standard procedure for image analysis. The analysis of the results led to the following conclusions: (i the sand fraction of the JP soil presented higher values for the morphometric indices roundness, elongation and compactness compared to sand fraction of the CP soil; and (ii the Sand Grain Image Capture System worked properly, with practicality.

  3. Distributed computer systems theory and practice

    Zedan, H S M

    2014-01-01

    Distributed Computer Systems: Theory and Practice is a collection of papers dealing with the design and implementation of operating systems, including distributed systems, such as the amoeba system, argus, Andrew, and grapevine. One paper discusses the concepts and notations for concurrent programming, particularly language notation used in computer programming, synchronization methods, and also compares three classes of languages. Another paper explains load balancing or load redistribution to improve system performance, namely, static balancing and adaptive load balancing. For program effici

  4. Novel analytical model for the determination of grain size distributions in nanocrystalline materials with low lattice microstrains by X-ray diffractometry

    Sanchez-Bajo, F.; Ortiz, A.L.; Cumbrera, F.L.

    2006-01-01

    We have developed a novel, analytical model for the determination of grain size distributions in nanocrystalline (nc) materials with low internal stresses by X-ray diffractometry (XRD). The model assumes explicitly that the XRD peaks are pseudo-Voigtian and that the grain size distributions are lognormal, both of which are assumptions amply supported by the experimental evidence. It was found analytically that the grain size dispersion depends on the shape of the XRD peaks only, whereas the grain size median depends on both the shape and width of the XRD peaks. In addition, the theoretical predictions resulting from the model were validated using standard XRD peaks obtained by computer simulation from first principles. Particular emphasis is given to the discussion of the validity limits of the model, and to the analysis of the influence of the characteristics of the grain size distributions on the nature of the XRD peaks. We then show how to calculate the average and apparent grain sizes from the grain size distribution determined with the model, and how this compares with the Scherrer method. Implications for the characterization of (undistorted and distorted) nc-materials are indicated, and a case study of an nc-powder of cubic ZrO 2 is presented. The application of the model itself is simple, involving only the fit of a pseudo-Voigt function to a single XRD peak followed by the use of two equations. This suggests that the model may have an important role to play in the characterization of nc-materials

  5. Novel analytical model for the determination of grain size distributions in nanocrystalline materials with low lattice microstrains by X-ray diffractometry

    Sanchez-Bajo, F. [Departamento de Electronica e Ingenieria Electromecanica, Escuela de Ingenierias Industriales, Universidad de Extremadura, Avda. de Elvas S/N, Badajoz 06071 (Spain); Ortiz, A.L. [Departamento de Electronica e Ingenieria Electromecanica, Escuela de Ingenierias Industriales, Universidad de Extremadura, Avda. de Elvas S/N, Badajoz 06071 (Spain)]. E-mail: alortiz@unex.es; Cumbrera, F.L. [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06071 (Spain)

    2006-01-15

    We have developed a novel, analytical model for the determination of grain size distributions in nanocrystalline (nc) materials with low internal stresses by X-ray diffractometry (XRD). The model assumes explicitly that the XRD peaks are pseudo-Voigtian and that the grain size distributions are lognormal, both of which are assumptions amply supported by the experimental evidence. It was found analytically that the grain size dispersion depends on the shape of the XRD peaks only, whereas the grain size median depends on both the shape and width of the XRD peaks. In addition, the theoretical predictions resulting from the model were validated using standard XRD peaks obtained by computer simulation from first principles. Particular emphasis is given to the discussion of the validity limits of the model, and to the analysis of the influence of the characteristics of the grain size distributions on the nature of the XRD peaks. We then show how to calculate the average and apparent grain sizes from the grain size distribution determined with the model, and how this compares with the Scherrer method. Implications for the characterization of (undistorted and distorted) nc-materials are indicated, and a case study of an nc-powder of cubic ZrO{sub 2} is presented. The application of the model itself is simple, involving only the fit of a pseudo-Voigt function to a single XRD peak followed by the use of two equations. This suggests that the model may have an important role to play in the characterization of nc-materials.

  6. Online Scheduling in Distributed Message Converter Systems

    Risse, Thomas; Wombacher, Andreas; Surridge, Mike; Taylor, Steve; Aberer, Karl

    The optimal distribution of jobs among hosts in distributed environments is an important factor to achieve high performance. The optimal strategy depends on the application. In this paper we present a new online scheduling strategy for distributed EDI converter system. The strategy is based on the

  7. Estimating the Grain Size Distribution of Mars based on Fragmentation Theory and Observations

    Charalambous, C.; Pike, W. T.; Golombek, M.

    2017-12-01

    We present here a fundamental extension to the fragmentation theory [1] which yields estimates of the distribution of particle sizes of a planetary surface. The model is valid within the size regimes of surfaces whose genesis is best reflected by the evolution of fragmentation phenomena governed by either the process of meteoritic impacts, or by a mixture with aeolian transportation at the smaller sizes. The key parameter of the model, the regolith maturity index, can be estimated as an average of that observed at a local site using cratering size-frequency measurements, orbital and surface image-detected rock counts and observations of sub-mm particles at landing sites. Through validation of ground truth from previous landed missions, the basis of this approach has been used at the InSight landing ellipse on Mars to extrapolate rock size distributions in HiRISE images down to 5 cm rock size, both to determine the landing safety risk and the subsequent probability of obstruction by a rock of the deployed heat flow mole down to 3-5 m depth [2]. Here we focus on a continuous extrapolation down to 600 µm coarse sand particles, the upper size limit that may be present through aeolian processes [3]. The parameters of the model are first derived for the fragmentation process that has produced the observable rocks via meteorite impacts over time, and therefore extrapolation into a size regime that is affected by aeolian processes has limited justification without further refinement. Incorporating thermal inertia estimates, size distributions observed by the Spirit and Opportunity Microscopic Imager [4] and Atomic Force and Optical Microscopy from the Phoenix Lander [5], the model's parameters in combination with synthesis methods are quantitatively refined further to allow transition within the aeolian transportation size regime. In addition, due to the nature of the model emerging in fractional mass abundance, the percentage of material by volume or mass that resides

  8. Distribution of the grain limit character in SiC and its effect on the diffusion of fission products in the TRISO fuel particles

    Cancino T, F.; Lopez H, E.

    2017-09-01

    At present is accepted that silver diffuses through silicium carbide (SiC) by diffusion in grain boundaries, although little is known about the characteristics of grain boundaries in SiC, and how these change depending on the type of sample. In this work, was observed that there are small but important differences between the SiC in the tri-structural isotropic (TRISO) particles and that of the monoliths, which could explain some of the differences observed in experiments on diffusion in the literature. Five different types (coatings and monoliths) of SiC produced by chemical vapor deposition (CVD) were characterized by electron backscatter diffraction (EBSD). In all the samples the SiC was mainly composed of high-angle grain boundaries (∼ 65%), with a small fraction of grain boundaries of low-angle (about 15%) and 20% of the coincidence site lattice (CSL). The morphology of the monoliths is constituted by large grains, surrounded by smaller grains; in the particles of the TRISO fuel, both columnar and equi axial grains were observed, with a more uniform distribution over the surface of the coating. (Author)

  9. The Importance of Physical Models for Deriving Dust Masses and Grain Size Distributions in Supernova Ejecta. I. Radiatively Heated Dust in the Crab Nebula

    Temim, Tea; Dwek, Eli

    2013-01-01

    Recent far-infrared (IR) observations of supernova remnants (SNRs) have revealed significantly large amounts of newly condensed dust in their ejecta, comparable to the total mass of available refractory elements. The dust masses derived from these observations assume that all the grains of a given species radiate at the same temperature, regardless of the dust heating mechanism or grain radius. In this paper, we derive the dust mass in the ejecta of the Crab Nebula, using a physical model for the heating and radiation from the dust. We adopt a power-law distribution of grain sizes and two different dust compositions (silicates and amorphous carbon), and calculate the heating rate of each dust grain by the radiation from the pulsar wind nebula. We find that the grains attain a continuous range of temperatures, depending on their size and composition. The total mass derived from the best-fit models to the observed IR spectrum is 0.019-0.13 Solar Mass, depending on the assumed grain composition. We find that the power-law size distribution of dust grains is characterized by a power-law index of 3.5-4.0 and a maximum grain size larger than 0.1 micron. The grain sizes and composition are consistent with what is expected for dust grains formed in a Type IIP supernova (SN). Our derived dust mass is at least a factor of two less than the mass reported in previous studies of the Crab Nebula that assumed more simplified two-temperature models. These models also require a larger mass of refractory elements to be locked up in dust than was likely available in the ejecta. The results of this study show that a physical model resulting in a realistic distribution of dust temperatures can constrain the dust properties and affect the derived dust masses. Our study may also have important implications for deriving grain properties and mass estimates in other SNRs and for the ultimate question of whether SNe are major sources of dust in the Galactic interstellar medium and in

  10. Protection of Distribution Systems with Distributed Energy Resources

    Bak-Jensen, Birgitte; Browne, Matthew; Calone, Roberto

    of 17 months of work of the Joint Working Group B5/C6.26/CIRED “Protection of Distribution Systems with Distributed Energy Resources”. The working group used the CIGRE report TB421 “The impact of Renewable Energy Sources and Distributed Generation on Substation Protection and Automation”, published...... by WG B5.34 as the entry document for the work on this report. In doing so, the group aligned the content and the scope of this report, the network structures considered, possible islanding, standardized communication and adaptive protection, interface protection, connection schemes and protection...... are listed (chapter 3). The first main part of the report starts with a summary of the backgrounds on DER and current practices in protection at the distribution level (chapter 4). This chapter contains an analysis of CIGRE TB421, protection relevant characteristics of DER, a review of current practices...

  11. Characteristic length scale of input data in distributed models: implications for modeling grain size

    Artan, Guleid A.; Neale, C. M. U.; Tarboton, D. G.

    2000-01-01

    The appropriate spatial scale for a distributed energy balance model was investigated by: (a) determining the scale of variability associated with the remotely sensed and GIS-generated model input data; and (b) examining the effects of input data spatial aggregation on model response. The semi-variogram and the characteristic length calculated from the spatial autocorrelation were used to determine the scale of variability of the remotely sensed and GIS-generated model input data. The data were collected from two hillsides at Upper Sheep Creek, a sub-basin of the Reynolds Creek Experimental Watershed, in southwest Idaho. The data were analyzed in terms of the semivariance and the integral of the autocorrelation. The minimum characteristic length associated with the variability of the data used in the analysis was 15 m. Simulated and observed radiometric surface temperature fields at different spatial resolutions were compared. The correlation between agreement simulated and observed fields sharply declined after a 10×10 m2 modeling grid size. A modeling grid size of about 10×10 m2 was deemed to be the best compromise to achieve: (a) reduction of computation time and the size of the support data; and (b) a reproduction of the observed radiometric surface temperature.

  12. Optimizing the grain size distribution for talc-magnesite ore flotation

    Škvarla Jiøí

    2001-06-01

    Full Text Available Flotation is the only separation method with an universal utilization. Along with the separation of particulate valuable or hazardous components from primary and seconadry mineral raw materials, it is of usage in biotechnologies and water cleaning. The success of the flotation separation crucially depends on the particle size distribution or composition of the ore charge entering the process. The paper deals with the problem of flotation treatment of talc-magnesite ore. The main components of the ore, i.e. talc and magnesite are appreciably different in their grindability and floatability. For such a type of raw material, grinding of the charge plays a very important role in the process. The (unwanted influence of ultrafine particles on the course of the flotation process is well known. On the other hand, in order to liberate and subsequently to selectively separate both the components, a maximum particle size has to be respected.An influence of artificial samples of selected particle size fractions on the flotation efficiency has been studied experimentally by the quantitative evaluation of flotation products. The flotation experiments on the samples provided an information not obtainable from traditional flotation tests. An adverse effect of the size fraction 0 – 0.04 mm was revealed, decreasing the flotation selectivity appreciably. These results are of theoretical and practical importance.

  13. OXYGEN DEPLETION IN THE INTERSTELLAR MEDIUM: IMPLICATIONS FOR GRAIN MODELS AND THE DISTRIBUTION OF ELEMENTAL OXYGEN

    Whittet, D. C. B.

    2010-01-01

    This paper assesses the implications of a recent discovery that atomic oxygen is being depleted from diffuse interstellar gas at a rate that cannot be accounted for by its presence in silicate and metallic oxide particles. To place this discovery in context, the uptake of elemental O into dust is considered over a wide range of environments, from the tenuous intercloud gas and diffuse clouds sampled by the depletion observations to dense clouds where ice mantles and gaseous CO become important reservoirs of O. The distribution of O in these contrasting regions is quantified in terms of a common parameter, the mean number density of hydrogen (n H ). At the interface between diffuse and dense phases (just before the onset of ice-mantle growth) as much as ∼160 ppm of the O abundance is unaccounted for. If this reservoir of depleted oxygen persists to higher densities it has implications for the oxygen budget in molecular clouds, where a shortfall of the same order is observed. Of various potential carriers, the most plausible appears to be a form of O-bearing carbonaceous matter similar to the organics found in cometary particles returned by the Stardust mission. The 'organic refractory' model for interstellar dust is re-examined in the light of these findings, and it is concluded that further observations and laboratory work are needed to determine whether this class of material is present in quantities sufficient to account for a significant fraction of the unidentified depleted oxygen.

  14. Grain-A Java data analysis system for Total Data Readout

    Rahkila, P.

    2008-01-01

    Grain is a data analysis system developed to be used with the novel Total Data Readout data acquisition system. In Total Data Readout all the electronics channels are read out asynchronously in singles mode and each data item is timestamped. Event building and analysis has to be done entirely in the software post-processing the data stream. A flexible and efficient event parser and the accompanying software system have been written entirely in Java. The design and implementation of the software are discussed along with experiences gained in running real-life experiments

  15. Strategy Guideline. Compact Air Distribution Systems

    Burdick, Arlan [IBACOS, Inc., Pittsburgh, PA (United States)

    2013-06-01

    This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  16. Internet and redefining tourism distribution system

    Đelić Tanja

    2004-01-01

    Full Text Available Since the introduction, computerized systems that manage reservation systems, rapidly became inevitable distribution channel for all service companies in tourist industry. GDS in reality using communication network connects service offer, selling personnel and air companies.

  17. DC Distribution Systems and Microgrids

    Dragicevic, Tomislav; Anvari-Moghaddam, Amjad; Quintero, Juan Carlos Vasquez

    2017-01-01

    summarized. Due to its attractive characteristics in terms of compliance with modern generation, storage and electronic load technologies, high reliability and current carrying capacity, as well as simple control, DC systems are already an indispensable part of power systems. Moreover, the existing......A qualitative overview of different hardware topologies and control systems for DC MGs has been presented in this chapter. Some challenges and design considerations of DC protections systems have also been discussed. Finally, applications of DC MGs in emerging smart grid applications have been...... challenges such as protection issues will be effectively resolved in the near future due to fast progress of semiconductor technology which is a key enabler cheap and reliable future DC solid-state protection systems. Therefore, it is the view of the author that more and more DC systems will appear...

  18. Economic Models and Algorithms for Distributed Systems

    Neumann, Dirk; Altmann, Jorn; Rana, Omer F

    2009-01-01

    Distributed computing models for sharing resources such as Grids, Peer-to-Peer systems, or voluntary computing are becoming increasingly popular. This book intends to discover fresh avenues of research and amendments to existing technologies, aiming at the successful deployment of commercial distributed systems

  19. Hybrid solar lighting distribution systems and components

    Muhs, Jeffrey D [Lenoir City, TN; Earl, Dennis D [Knoxville, TN; Beshears, David L [Knoxville, TN; Maxey, Lonnie C [Powell, TN; Jordan, John K [Oak Ridge, TN; Lind, Randall F [Lenoir City, TN

    2011-07-05

    A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

  20. Formal Specification of Distributed Information Systems

    Vis, J.; Brinksma, Hendrik; de By, R.A.; de By, R.A.

    The design of distributed information systems tends to be complex and therefore error-prone. However, in the field of monolithic, i.e. non-distributed, information systems much has already been achieved, and by now, the principles of their design seem to be fairly well-understood. The past decade

  1. RF phase distribution systems at the SLC

    Jobe, R.K.; Schwarz, H.D.

    1989-04-01

    Modern large linear accelerators require RF distribution systems with minimal phase drifts and errors. Through the use of existing RF coaxial waveguides, and additional installation of phase reference cables and monitoring equipment, stable RF distribution for the SLC has been achieved. This paper discusses the design and performance of SLAC systems, and some design considerations for future colliders. 6 refs., 4 figs

  2. Silver disinfection in water distribution systems

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  3. Rapid Prototyping of Formally Modelled Distributed Systems

    Buchs, Didier; Buffo, Mathieu; Titsworth, Frances M.

    1999-01-01

    This paper presents various kinds of prototypes, used in the prototyping of formally modelled distributed systems. It presents the notions of prototyping techniques and prototype evolution, and shows how to relate them to the software life-cycle. It is illustrated through the use of the formal modelling language for distributed systems CO-OPN/2.

  4. Programming a Distributed System Using Shared Objects

    Tanenbaum, A.S.; Bal, H.E.; Kaashoek, M.F.

    1993-01-01

    Building the hardware for a high-performance distributed computer system is a lot easier than building its software. The authors describe a model for programming distributed systems based on abstract data types that can be replicated on all machines that need them. Read operations are done locally,

  5. BIOFILMS IN DRINKING WATER DISTRIBUTION SYSTEMS

    Virtually anywhere a surface comes into contact with the water in a distribution system, one can find biofilms. Biofilms are formed in distribution system pipelines when microbial cells attach to pipe surfaces and multiply to form a film or slime layer on the pipe. Probably withi...

  6. Grid-connected distributed solar power systems

    Moyle, R.; Chernoff, H.; Schweizer, T.

    This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

  7. Reliability assessment of distribution power systems including distributed generations

    Megdiche, M.

    2004-12-01

    Nowadays, power systems have reached a good level of reliability. Nevertheless, considering the modifications induced by the connections of small independent producers to distribution networks, there's a need to assess the reliability of these new systems. Distribution networks present several functional characteristics, highlighted by the qualitative study of the failures, as dispersed loads at several places, variable topology and some electrotechnical phenomena which must be taken into account to model the events that can occur. The adopted reliability calculations method is Monte Carlo simulations, the probabilistic method most powerful and most flexible to model complex operating of the distribution system. We devoted a first part on the case of a 20 kV feeder to which a cogeneration unit is connected. The method was applied to a software of stochastic Petri nets simulations. Then a second part related to the study of a low voltage power system supplied by dispersed generations. Here, the complexity of the events required to code the method in an environment of programming allowing the use of power system calculations (load flow, short-circuit, load shedding, management of units powers) in order to analyse the system state for each new event. (author)

  8. Significant Corrosion Resistance in an Ultrafine-Grained Al6063 Alloy with a Bimodal Grain-Size Distribution through a Self-Anodic Protection Mechanism

    Mahdieh Shakoori Oskooie

    2016-12-01

    Full Text Available The bimodal microstructures of Al6063 consisting of 15, 30, and 45 vol. % coarse-grained (CG bands within the ultrafine-grained (UFG matrix were synthesized via blending of high-energy mechanically milled powders with unmilled powders followed by hot powder extrusion. The corrosion behavior of the bimodal specimens was assessed by means of polarization, steady-state cyclic polarization and impedance tests, whereas their microstructural features and corrosion products were examined using optical microscopy (OM, scanning transmission electron microscopy (STEM, field emission scanning electron microscopy (FE-SEM, electron backscattered diffraction (EBSD, energy dispersive spectroscopy (EDS, and X-ray diffraction (XRD techniques. The bimodal Al6063 containing 15 vol. % CG phase exhibits the highest corrosion resistance among the bimodal microstructures and even superior electrochemical behavior compared with the plain UFG and CG materials in the 3.5% NaCl solution. The enhanced corrosion resistance is attributed to the optimum cathode to anode surface area ratio that gives rise to the formation of an effective galvanic couple between CG areas and the UFG matrix. The operational galvanic coupling leads to the domination of a “self-anodic protection system” on bimodal microstructure and consequently forms a uniform thick protective passive layer over it. In contrast, the 45 vol. % CG bimodal specimen shows the least corrosion resistance due to the catastrophic galvanic corrosion in UFG regions. The observed results for UFG Al6063 suggest that metallurgical tailoring of the grain structure in terms of bimodal microstructures leads to simultaneous enhancement in the electrochemical behavior and mechanical properties of passivable alloys that are usually inversely correlated. The mechanism of self-anodic protection for passivable metals with bimodal microstructures is discussed here for the first time.

  9. Large scale network-centric distributed systems

    Sarbazi-Azad, Hamid

    2014-01-01

    A highly accessible reference offering a broad range of topics and insights on large scale network-centric distributed systems Evolving from the fields of high-performance computing and networking, large scale network-centric distributed systems continues to grow as one of the most important topics in computing and communication and many interdisciplinary areas. Dealing with both wired and wireless networks, this book focuses on the design and performance issues of such systems. Large Scale Network-Centric Distributed Systems provides in-depth coverage ranging from ground-level hardware issu

  10. Differences Between Distributed and Parallel Systems

    Brightwell, R.; Maccabe, A.B.; Rissen, R.

    1998-10-01

    Distributed systems have been studied for twenty years and are now coming into wider use as fast networks and powerful workstations become more readily available. In many respects a massively parallel computer resembles a network of workstations and it is tempting to port a distributed operating system to such a machine. However, there are significant differences between these two environments and a parallel operating system is needed to get the best performance out of a massively parallel system. This report characterizes the differences between distributed systems, networks of workstations, and massively parallel systems and analyzes the impact of these differences on operating system design. In the second part of the report, we introduce Puma, an operating system specifically developed for massively parallel systems. We describe Puma portals, the basic building blocks for message passing paradigms implemented on top of Puma, and show how the differences observed in the first part of the report have influenced the design and implementation of Puma.

  11. The prevalence of deoxynivalenol and its derivatives in the spring wheat grain from different agricultural production systems in Lithuania.

    Janaviciene, Sigita; Mankeviciene, Audrone; Suproniene, Skaidre; Kochiieru, Yuliia; Keriene, Ilona

    2018-02-22

    Deoxynivalenol (DON) together with two acetylated derivatives, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON) occurs in cereal grains and their products. Co-occurrence of DON and acetylated derivatives in cereal grain is detected worldwide. Until now, DON and its derivatives have been considered equally toxic by health authorities. In this study, we analysed 103 samples of spring wheat grain, originating from the fields of different production systems in Lithuania, for the co-occurrence of type-B trichothecenes (DON, 3-ADON, 15-ADON). The samples were classified according to the production system-organic, sustainable and intensive. Mycotoxin levels in the spring wheat grain samples were determined by the HPLC method with UV detection. The type-B trichothecenes were found to be present at higher concentrations in the grain from the intensive production system. Eighty-one percent of the spring wheat grain samples from the intensive production system were co-contaminated with a combination of DON+3-ADON+15-ADON, 1% with DON+3-ADON. Additionally, DON+15-ADON and DON were found in 5% and 10% of the tested samples, respectively. Two percent of the samples were free from mycotoxins. In the grain samples from the sustainable production system, DON and a combination of DON+3-ADON showed a higher incidence - 47% and 23%, respectively. The samples with a combination of DON+3-ADON+15-ADON accounted for 18%. Completely different results were obtained from the analyses of organic grain samples. A large number of the organic spring wheat grain samples were contaminated with DON+3-ADON (55%) or DON (36%). The combination of DON+3-ADON+15-ADON was not present, while DON+15-ADON was present in 9% of the samples tested. The production systems did not lead to significant differences in mycotoxin levels, although a trend toward higher incidence and higher contamination was observed for the samples from the intensive and sustainable production systems.

  12. Asymptotic work distributions in driven bistable systems

    Nickelsen, D; Engel, A

    2012-01-01

    The asymptotic tails of the probability distributions of thermodynamic quantities convey important information about the physics of nanoscopic systems driven out of equilibrium. We apply a recently proposed method to analytically determine the asymptotics of work distributions in Langevin systems to an one-dimensional model of single-molecule force spectroscopy. The results are in excellent agreement with numerical simulations, even in the centre of the distributions. We compare our findings with a recent proposal for an universal form of the asymptotics of work distributions in single-molecule experiments.

  13. Centralised and distributed electricity systems

    Bouffard, Francois; Kirschen, Daniel S.

    2008-01-01

    Because of their high level of integration, centralised energy supply systems are vulnerable to disturbances in the supply chain. In the case of electricity especially, this supply paradigm is losing some of its appeal. Apart from vulnerability, a number of further aggravating factors are reducing its attractiveness. They include the depletion of fossil fuels and their climate change impact, the insecurities affecting energy transportation infrastructure, and the desire of investors to minimise risks through the deployment of smaller-scale, modular generation and transmission systems. Small-scale decentralised systems, where energy production and consumption are usually tightly coupled, are emerging as a viable alternative. They are less dependent upon centralised energy supply, and can sometimes use more than one energy source. They are less sensitive to the uncertain availability of remote primary energy and transportation networks. In addition, the close connection between energy generation and use makes decentralised systems cleaner because they are most often based on renewable energies or on high-efficiency fossil fuel-based technologies such as combined heat and power (CHP). Fully decentralised energy supply is not currently possible or even truly desirable. The secure and clean energy systems of the future will be those flexible enough to allow for a spectrum of hybrid modes of operation and investment, combining the best attributes of both paradigms. A large part of this flexibility will come from the networks that make it possible to combine these two types of infrastructures and obtain the benefits of both approaches

  14. Light distribution system comprising spectral conversion means

    2012-01-01

    , longer wavelength,a spectral conversion characteristics of the spectral conversion fibre being essentially determined by the spectral absorption and emission properties of the photoluminescent agent, the amount of photo- luminescent agent,and the distribution of the photoluminescent agent in the spectral......System (200, 300) for the distribution of white light, having a supply side (201, 301, 401) and a delivery side (202, 302, 402), the system being configured for guiding light with a multitude of visible wavelengths in a propagation direction P from the supply side to the distribution side...... of providing a light distribution system and a method of correcting the spectral transmission characteristics of a light distribution system are disclosed....

  15. Evaluation of two typical distributed energy systems

    Han, Miaomiao; Tan, Xiu

    2018-03-01

    According to the two-natural gas distributed energy system driven by gas engine driven and gas turbine, in this paper, the first and second laws of thermodynamics are used to measure the distributed energy system from the two parties of “quantity” and “quality”. The calculation results show that the internal combustion engine driven distributed energy station has a higher energy efficiency, but the energy efficiency is low; the gas turbine driven distributed energy station energy efficiency is high, but the primary energy utilization rate is relatively low. When configuring the system, we should determine the applicable natural gas distributed energy system technology plan and unit configuration plan according to the actual load factors of the project and the actual factors such as the location, background and environmental requirements of the project. “quality” measure, the utilization of waste heat energy efficiency index is proposed.

  16. PFS: a distributed and customizable file system

    Bosch, H.G.P.; Mullender, Sape J.

    1996-01-01

    In this paper we present our ongoing work on the Pegasus File System (PFS), a distributed and customizable file system that can be used for off-line file system experiments and on-line file system storage. PFS is best described as an object-oriented component library from which either a true file

  17. A 300 kyr record of aridity and wind strength in southwestern Africa: evidence from grain-size distributions of sediments on Walvis Ridge, SE Atlantic.

    Stuut, J.-B. W.; Prins, M.A.; Schneider, R.S.; Weltje, G.J.; Jansen, J.H.F.; Postma, G.

    2002-01-01

    The terrigenous fraction of sediments recovered from Walvis Ridge, SE Atlantic Ocean, reveals a history of southwestern African climate of the last 300 kyr. End-member modelling of a data set of grain-size distributions (n = 428) results in three end members. The two coarsest end members are

  18. The effect of kauri (Agathis australis) on grain size distribution and clay mineralogy of andesitic soils in the Waitakere Ranges, New Zealand

    Jongkind, A.G.; Buurman, P.

    2006-01-01

    Kauri (Agathis australis) is generally associated with intense podzolisation, but little research has been carried out to substantiate this. We studied soil profiles, grain size distribution patterns and clay mineralogy under kauri and broadleaf/tree fern vegetation in the Waitakere Ranges, North

  19. Thirteen years of Aeolian dust dynamics in a desert region (Negev desert, Israel): analysis of horizontal and vertical dust flux, vertical dust distribution and dust grain size

    Offer, Z.Y.; Goossens, D.

    2004-01-01

    At Sede Boqer (northern Negev desert, Israel), aeolian dust dynamics have been measured during the period 1988–2000. This study focuses on temporal records of the vertical and horizontal dust flux, the vertical distribution of the dust particles in the atmosphere, and the grain size of the

  20. Archtecture of distributed real-time systems

    Wing Leung, Cheuk

    2013-01-01

    CRAFTERS (Constraint and Application Driven Framework for Tailoring Embedded Real-time System) project aims to address the problem of uncertainty and heterogeneity in a distributed system by providing seamless, portable connectivity and middleware. This thesis contributes to the project by investigating the techniques that can be used in a distributed real-time embedded system. The conclusion is that, there is a list of specifications to be meet in order to provide a transparent and real-time...

  1. Support system for ATLAS distributed computing operations

    Kishimoto, Tomoe; The ATLAS collaboration

    2018-01-01

    The ATLAS distributed computing system has allowed the experiment to successfully meet the challenges of LHC Run 2. In order for distributed computing to operate smoothly and efficiently, several support teams are organized in the ATLAS experiment. The ADCoS (ATLAS Distributed Computing Operation Shifts) is a dedicated group of shifters who follow and report failing jobs, failing data transfers between sites, degradation of ATLAS central computing services, and more. The DAST (Distributed Analysis Support Team) provides user support to resolve issues related to running distributed analysis on the grid. The CRC (Computing Run Coordinator) maintains a global view of the day-to-day operations. In this presentation, the status and operational experience of the support system for ATLAS distributed computing in LHC Run 2 will be reported. This report also includes operations experience from the grid site point of view, and an analysis of the errors that create the biggest waste of wallclock time. The report of oper...

  2. A DISTRIBUTED SMART HOME ARTIFICIAL INTELLIGENCE SYSTEM

    Lynggaard, Per

    2013-01-01

    A majority of the research performed today explore artificial intelligence in smart homes by using a centralized approach where a smart home server performs the necessary calculations. This approach has some disadvantages that can be overcome by shifting focus to a distributed approach where...... the artificial intelligence system is implemented as distributed as agents running parts of the artificial intelligence system. This paper presents a distributed smart home architecture that distributes artificial intelligence in smart homes and discusses the pros and cons of such a concept. The presented...... distributed model is a layered model. Each layer offers a different complexity level of the embedded distributed artificial intelligence. At the lowest layer smart objects exists, they are small cheap embedded microcontroller based smart devices that are powered by batteries. The next layer contains a more...

  3. Parallel and Distributed System Simulation

    Dongarra, Jack

    1998-01-01

    This exploratory study initiated our research into the software infrastructure necessary to support the modeling and simulation techniques that are most appropriate for the Information Power Grid. Such computational power grids will use high-performance networking to connect hardware, software, instruments, databases, and people into a seamless web that supports a new generation of computation-rich problem solving environments for scientists and engineers. In this context we looked at evaluating the NetSolve software environment for network computing that leverages the potential of such systems while addressing their complexities. NetSolve's main purpose is to enable the creation of complex applications that harness the immense power of the grid, yet are simple to use and easy to deploy. NetSolve uses a modular, client-agent-server architecture to create a system that is very easy to use. Moreover, it is designed to be highly composable in that it readily permits new resources to be added by anyone willing to do so. In these respects NetSolve is to the Grid what the World Wide Web is to the Internet. But like the Web, the design that makes these wonderful features possible can also impose significant limitations on the performance and robustness of a NetSolve system. This project explored the design innovations that push the performance and robustness of the NetSolve paradigm as far as possible without sacrificing the Web-like ease of use and composability that make it so powerful.

  4. Integrating photovoltaics into utility distribution systems

    Zaininger, H.W.; Barnes, P.R.

    1995-01-01

    Electric utility distribution system impacts associated with the integration of distributed photovoltaic (PV) energy sources vary from site to site and utility to utility. The objective of this paper is to examine several utility- and site-specific conditions which may affect economic viability of distributed PV applications to utility systems. Assessment methodology compatible with technical and economic assessment techniques employed by utility engineers and planners is employed to determine PV benefits for seven different utility systems. The seven case studies are performed using utility system characteristics and assumptions obtained from appropriate utility personnel. The resulting site-specific distributed PV benefits increase nonsite-specific generation system benefits available to central station PV plants as much as 46%, for one utility located in the Southwest

  5. Equilibrium distribution function in collisionless systems

    Pergamenshchik, V.M.

    1988-01-01

    Collisionless systems of a large number of N particles interacting by Coulomb forces are widely spread in cosmic and laboratory plasma. A statistical theory of equilibrium state of collisionless Coulomb systems which evolution obeys Vlasov equation is proposed. The developed formalism permits a sequential consideration of such distributed in one-particle six-dimensional phase space of a system and to obtain a simple result: equilibrium distribution function has the form of Fermi-Dirac distribution and doesn't depend on initial state factors

  6. Advanced smartgrids for distribution system operators

    Boillot, Marc

    2014-01-01

    The dynamic of the Energy Transition is engaged in many region of the World. This is a real challenge for electric systems and a paradigm shift for existing distribution networks. With the help of "advanced" smart technologies, the Distribution System Operators will have a central role to integrate massively renewable generation, electric vehicle and demand response programs. Many projects are on-going to develop and assess advanced smart grids solutions, with already some lessons learnt. In the end, the Smart Grid is a mean for Distribution System Operators to ensure the quality and the secu

  7. Science network resources: Distributed systems

    Cline, Neal

    1991-01-01

    The Master Directory, which is overview information about whole data sets, is outlined. The data system environment is depicted. The question is explored of what is a prototype international directory including purpose and features. Advantages of on-line directories are listed. Interconnected directory assumptions are given. A description of given of DIF (Directory Interchange Format), which is an exchange file for directory information, along with information content of DIF and directories. The directory population status is given in a percentage viewgraph. The present and future directory interconnections status at GSFC is also listed.

  8. PROWAY - a standard for distributed control systems

    Gellie, R.W.

    1980-01-01

    The availability of cheap and powerful microcomputer and data communications equipment has led to a major revision of instrumentation and control systems. Intelligent devices can now be used and distributed about the control system in a systematic and economic manner. These sub-units are linked by a communications system to provide a total system capable of meeting the required plant objectives. PROWAY, an international standard process data highway for interconnecting processing units in distributed industrial process control systems, is currently being developed. This paper describes the salient features and current status of the PROWAY effort. (auth)

  9. Water distribution systems design optimisation using metaheuristics ...

    The topic of multi-objective water distribution systems (WDS) design optimisation using metaheuristics is investigated, comparing numerous modern metaheuristics, including several multi-objective evolutionary algorithms, an estimation of distribution algorithm and a recent hyperheuristic named AMALGAM (an evolutionary ...

  10. Programming Languages for Distributed Computing Systems

    Bal, H.E.; Steiner, J.G.; Tanenbaum, A.S.

    1989-01-01

    When distributed systems first appeared, they were programmed in traditional sequential languages, usually with the addition of a few library procedures for sending and receiving messages. As distributed applications became more commonplace and more sophisticated, this ad hoc approach became less

  11. Distributed Administrative Management Information System (DAMIS).

    Juckiewicz, Robert; Kroculick, Joseph

    Columbia University's major program to distribute its central administrative data processing to its various schools and departments is described. The Distributed Administrative Management Information System (DAMIS) will link every department and school within the university via micrcomputers, terminals, and/or minicomputers to the central…

  12. DIstributed VIRtual System (DIVIRS) Project

    Schorr, Herbert; Neuman, B. Clifford; Gaines, Stockton R.; Mizell, David

    1996-01-01

    The development of Prospero moved from the University of Washington to ISI and several new versions of the software were released from ISI during the contract period. Changes in the first release from ISI included bug fixes and extensions to support the needs of specific users. Among these changes was a new option to directory queries that allows attributes to be returned for all files in a directory together with the directory listing. This change greatly improves the performance of their server and reduces the number of packets sent across their trans-pacific connection to the rest of the internet. Several new access method were added to the Prospero file method. The Prospero Data Access Protocol was designed, to support secure retrieval of data from systems running Prospero.

  13. Analysis Framework of China’s Grain Production System: A Spatial Resilience Perspective

    Dazhuan Ge

    2017-12-01

    Full Text Available China’s grain production has transformed from absolute shortage to a current structural oversupply. High-intensity production introduced further challenges for the eco-environment, smallholder livelihood, and the man-land interrelationship. Driven by urban-rural transformation, research on food security patterns and grain production has expanded into a new field. To analyze the challenges and required countermeasures for China’s grain production system (GPS, this study constructed a theoretical GPS framework based on space resilience. Firstly, a new GPS concept was proposed and a functional system was established for protecting the regional food security, thus guaranteeing smallholder livelihood, stabilizing urban-rural transformation, and sustaining the eco-environment in terms of economic, social, and ecological attributes of the GPS. Secondly, based on a cross-scale interaction analysis that varied from a smallholder scale to a global scale, the systematic crisis of the GPS was analyzed. Thirdly, a cross-scale analytic framework of the GPS was formed from the perspective of spatial resilience, integrating both inner and external disturbance factors of the GPS. Both spatial heterogeneity and connectivity of internal and external disturbance factors are important contents of system space resilience. Finally, the hierarchy of spatial resilience of GPS became clear. The transformation of labor force and the land use transition form key thresholds of the GPS. In summary: based on protecting the basic functions of the GPS, the cross-scale effect of systematic disturbance factors and relevant countermeasures for spatial resilience are effectively influenced by the coordination of the interests of multiple stakeholders; spatial resilience is an effective analytical tool for GPS regulation, providing a reference for revealing the inherent mechanism and functional evolution of the GPS in the process of urban-rural transformation.

  14. AC distribution system for TFTR pulsed loads

    Carroll, R.F.; Ramakrishnan, S.; Lemmon, G.N.; Moo, W.I.

    1977-01-01

    This paper outlines the AC distribution system associated with the Tokamak Fusion Test Reactor and discusses the significant areas related to design, protection, and equipment selection, particularly where there is a departure from normal utility and industrial applications

  15. A distributed computer system for digitising machines

    Bairstow, R.; Barlow, J.; Waters, M.; Watson, J.

    1977-07-01

    This paper describes a Distributed Computing System, based on micro computers, for the monitoring and control of digitising tables used by the Rutherford Laboratory Bubble Chamber Research Group in the measurement of bubble chamber photographs. (author)

  16. Man-systems distributed system for Space Station Freedom

    Lewis, J. L.

    1990-01-01

    Viewgraphs on man-systems distributed system for Space Station Freedom are presented. Topics addressed include: description of man-systems (definition, requirements, scope, subsystems, and topologies); implementation (approach, tools); man-systems interfaces (system to element and system to system); prime/supporting development relationship; selected accomplishments; and technical challenges.

  17. Supervisory Control and Diagnostics System Distributed Operating System

    McGoldrick, P.R.

    1979-01-01

    This paper contains a description of the Supervisory Control and Diagnostics System (SCDS) Distributed Operating System. The SCDS consists of nine 32-bit minicomputers with shared memory. The system's main purpose is to control a large Mirror Fusion Test Facility

  18. The origin of dose distributions in fluvial sediments, and the prospect of dating single grains from fluvial deposits using optically stimulated luminescence

    Olley, J M; Roberts, R G

    1999-01-01

    We examine the causes of the asymmetric distributions of dose observed from measurements of the optically stimulated luminescence emitted by small aliquots of fluvial quartz, and deduce that the asymmetry arises as a result of samples being composed of a mix of mainly well bleached grains with grains that were effectively unbleached at the time of deposition. We demonstrate that the shapes of the dose distributions can be used to assess the likelihood that aliquots consist only of grains that were well-bleached at the time of deposition. The more asymmetric the distribution, the greater the probability that the aliquots with the lowest dose most closely represent the true burial dose. Single grains with differing doses are present in each of the samples examined, and the population with the lowest dose gives an optical age consistent with the expected burial age. This result implies that the beta-dose heterogeneity in these deposits is small, and that the effects of micro-dosimetric variations on optical dati...

  19. Distributed context-aware systems

    Ferreira, Paulo

    2014-01-01

    Context-aware systems aim to deliver a rich user experience by taking into?account the current user context (location, time, activity, etc.), possibly?captured without his intervention. For example, cell phones are now able to?continuously update a user's location while, at the same time, users execute?an increasing amount of activities online, where their actions may be easily?captured (e.g. login in a web application) without user consent. In the last decade, this topic has seen numerous developments that demonstrate its relevance and usefulness. The?trend was accelerated with the widespread?availability of powerful mobile devices (e.g. smartphones) that include a myriad of?sensors which enable applications to capture the user context. However, there are several challenges that must be addressed; we focus on scalability?(large number of context aware messages) and privacy (personal data that may be propagated).?This book is organized in five chapters starting with an introduction to?the theme raising the mo...

  20. Distributed operating system for NASA ground stations

    Doyle, John F.

    1987-01-01

    NASA ground stations are characterized by ever changing support requirements, so application software is developed and modified on a continuing basis. A distributed operating system was designed to optimize the generation and maintenance of those applications. Unusual features include automatic program generation from detailed design graphs, on-line software modification in the testing phase, and the incorporation of a relational database within a real-time, distributed system.

  1. Distributed computer control system for reactor optimization

    Williams, A.H.

    1983-01-01

    At the Oldbury power station a prototype distributed computer control system has been installed. This system is designed to support research and development into improved reactor temperature control methods. This work will lead to the development and demonstration of new optimal control systems for improvement of plant efficiency and increase of generated output. The system can collect plant data from special test instrumentation connected to dedicated scanners and from the station's existing data processing system. The system can also, via distributed microprocessor-based interface units, make adjustments to the desired reactor channel gas exit temperatures. The existing control equipment will then adjust the height of control rods to maintain operation at these temperatures. The design of the distributed system is based on extensive experience with distributed systems for direct digital control, operator display and plant monitoring. The paper describes various aspects of this system, with particular emphasis on: (1) the hierarchal system structure; (2) the modular construction of the system to facilitate installation, commissioning and testing, and to reduce maintenance to module replacement; (3) the integration of the system into the station's existing data processing system; (4) distributed microprocessor-based interfaces to the reactor controls, with extensive security facilities implemented by hardware and software; (5) data transfer using point-to-point and bussed data links; (6) man-machine communication based on VDUs with computer input push-buttons and touch-sensitive screens; and (7) the use of a software system supporting a high-level engineer-orientated programming language, at all levels in the system, together with comprehensive data link management

  2. Strategy Guideline: Compact Air Distribution Systems

    Burdick, A.

    2013-06-01

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  3. Distributed redundancy and robustness in complex systems

    Randles, Martin

    2011-03-01

    The uptake and increasing prevalence of Web 2.0 applications, promoting new large-scale and complex systems such as Cloud computing and the emerging Internet of Services/Things, requires tools and techniques to analyse and model methods to ensure the robustness of these new systems. This paper reports on assessing and improving complex system resilience using distributed redundancy, termed degeneracy in biological systems, to endow large-scale complicated computer systems with the same robustness that emerges in complex biological and natural systems. However, in order to promote an evolutionary approach, through emergent self-organisation, it is necessary to specify the systems in an \\'open-ended\\' manner where not all states of the system are prescribed at design-time. In particular an observer system is used to select robust topologies, within system components, based on a measurement of the first non-zero Eigen value in the Laplacian spectrum of the components\\' network graphs; also known as the algebraic connectivity. It is shown, through experimentation on a simulation, that increasing the average algebraic connectivity across the components, in a network, leads to an increase in the variety of individual components termed distributed redundancy; the capacity for structurally distinct components to perform an identical function in a particular context. The results are applied to a specific application where active clustering of like services is used to aid load balancing in a highly distributed network. Using the described procedure is shown to improve performance and distribute redundancy. © 2010 Elsevier Inc.

  4. Support for User Interfaces for Distributed Systems

    Eychaner, Glenn; Niessner, Albert

    2005-01-01

    An extensible Java(TradeMark) software framework supports the construction and operation of graphical user interfaces (GUIs) for distributed computing systems typified by ground control systems that send commands to, and receive telemetric data from, spacecraft. Heretofore, such GUIs have been custom built for each new system at considerable expense. In contrast, the present framework affords generic capabilities that can be shared by different distributed systems. Dynamic class loading, reflection, and other run-time capabilities of the Java language and JavaBeans component architecture enable the creation of a GUI for each new distributed computing system with a minimum of custom effort. By use of this framework, GUI components in control panels and menus can send commands to a particular distributed system with a minimum of system-specific code. The framework receives, decodes, processes, and displays telemetry data; custom telemetry data handling can be added for a particular system. The framework supports saving and later restoration of users configurations of control panels and telemetry displays with a minimum of effort in writing system-specific code. GUIs constructed within this framework can be deployed in any operating system with a Java run-time environment, without recompilation or code changes.

  5. Comparison between Different Air Distribution Systems

    Nielsen, Peter V.

    The aim of an air conditioning system is to remove excess heat in a room and replace room air with fresh air to obtain a high air quality. It is not sufficient to remove heat and contaminated air, it is also necessary to distribute and control the air movement in the room to create thermal comfort...... in the occupied zone. Most air distribution systems are based on mixing ventilation with ceiling or wall-mounted diffusers or on displacement ventilation with wall-mounted low velocity diffusers. New principles for room air distribution were introduced during the last decades, as the textile terminals mounted...... in the ceiling and radial diffusers with swirling flow also mounted in the ceiling. This paper addresses five air distribution systems in all, namely mixing ventilation from a wallmounted terminal, mixing ventilation from a ceiling-mounted diffuser, mixing ventilation from a ceiling-mounted diffuser...

  6. Bluetooth-based distributed measurement system

    Tang Baoping; Chen Zhuo; Wei Yuguo; Qin Xiaofeng

    2007-01-01

    A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit

  7. Bluetooth-based distributed measurement system

    Tang, Baoping; Chen, Zhuo; Wei, Yuguo; Qin, Xiaofeng

    2007-07-01

    A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

  8. Bluetooth-based distributed measurement system

    Tang Baoping; Chen Zhuo; Wei Yuguo; Qin Xiaofeng [Department of Mechatronics, College of Mechanical Engineering, Chongqing University, Chongqing, 400030 (China)

    2007-07-15

    A novel distributed wireless measurement system, which is consisted of a base station, wireless intelligent sensors and relay nodes etc, is established by combining of Bluetooth-based wireless transmission, virtual instrument, intelligent sensor, and network. The intelligent sensors mounted on the equipments to be measured acquire various parameters and the Bluetooth relay nodes get the acquired data modulated and sent to the base station, where data analysis and processing are done so that the operational condition of the equipment can be evaluated. The establishment of the distributed measurement system is discussed with a measurement flow chart for the distributed measurement system based on Bluetooth technology, and the advantages and disadvantages of the system are analyzed at the end of the paper and the measurement system has successfully been used in Daqing oilfield, China for measurement of parameters, such as temperature, flow rate and oil pressure at an electromotor-pump unit.

  9. Integrating CLIPS applications into heterogeneous distributed systems

    Adler, Richard M.

    1991-01-01

    SOCIAL is an advanced, object-oriented development tool for integrating intelligent and conventional applications across heterogeneous hardware and software platforms. SOCIAL defines a family of 'wrapper' objects called agents, which incorporate predefined capabilities for distributed communication and control. Developers embed applications within agents and establish interactions between distributed agents via non-intrusive message-based interfaces. This paper describes a predefined SOCIAL agent that is specialized for integrating C Language Integrated Production System (CLIPS)-based applications. The agent's high-level Application Programming Interface supports bidirectional flow of data, knowledge, and commands to other agents, enabling CLIPS applications to initiate interactions autonomously, and respond to requests and results from heterogeneous remote systems. The design and operation of CLIPS agents are illustrated with two distributed applications that integrate CLIPS-based expert systems with other intelligent systems for isolating and mapping problems in the Space Shuttle Launch Processing System at the NASA Kennedy Space Center.

  10. Distributed Access View Integrated Database (DAVID) system

    Jacobs, Barry E.

    1991-01-01

    The Distributed Access View Integrated Database (DAVID) System, which was adopted by the Astrophysics Division for their Astrophysics Data System, is a solution to the system heterogeneity problem. The heterogeneous components of the Astrophysics problem is outlined. The Library and Library Consortium levels of the DAVID approach are described. The 'books' and 'kits' level is discussed. The Universal Object Typer Management System level is described. The relation of the DAVID project with the Small Business Innovative Research (SBIR) program is explained.

  11. Autonomous Information Unit for Fine-Grain Data Access Control and Information Protection in a Net-Centric System

    Chow, Edward T.; Woo, Simon S.; James, Mark; Paloulian, George K.

    2012-01-01

    As communication and networking technologies advance, networks will become highly complex and heterogeneous, interconnecting different network domains. There is a need to provide user authentication and data protection in order to further facilitate critical mission operations, especially in the tactical and mission-critical net-centric networking environment. The Autonomous Information Unit (AIU) technology was designed to provide the fine-grain data access and user control in a net-centric system-testing environment to meet these objectives. The AIU is a fundamental capability designed to enable fine-grain data access and user control in the cross-domain networking environments, where an AIU is composed of the mission data, metadata, and policy. An AIU provides a mechanism to establish trust among deployed AIUs based on recombining shared secrets, authentication and verify users with a username, X.509 certificate, enclave information, and classification level. AIU achieves data protection through (1) splitting data into multiple information pieces using the Shamir's secret sharing algorithm, (2) encrypting each individual information piece using military-grade AES-256 encryption, and (3) randomizing the position of the encrypted data based on the unbiased and memory efficient in-place Fisher-Yates shuffle method. Therefore, it becomes virtually impossible for attackers to compromise data since attackers need to obtain all distributed information as well as the encryption key and the random seeds to properly arrange the data. In addition, since policy can be associated with data in the AIU, different user access and data control strategies can be included. The AIU technology can greatly enhance information assurance and security management in the bandwidth-limited and ad hoc net-centric environments. In addition, AIU technology can be applicable to general complex network domains and applications where distributed user authentication and data protection are

  12. Fine grained event processing on HPCs with the ATLAS Yoda system

    Calafiura, Paolo; The ATLAS collaboration; Guan, Wen; Maeno, Tadashi; Nilsson, Paul; Oleynik, Danila; Panitkin, Sergey; Tsulaia, Vakhtang; van Gemmeren, Peter; Wenaus, Torre

    2015-01-01

    High performance computing facilities present unique challenges and opportunities for HENP event processing. The massive scale of many HPC systems means that fractionally small utilizations can yield large returns in processing throughput. Parallel applications which can dynamically and efficiently fill any scheduling opportunities the resource presents benefit both the facility (maximal utilization) and the (compute-limited) science. The ATLAS Yoda system provides this capability to HENP-like event processing applications by implementing event-level processing in an MPI-based master-client model that integrates seamlessly with the more broadly scoped ATLAS Event Service. Fine grained, event level work assignments are intelligently dispatched to parallel workers to sustain full utilization on all cores, with outputs streamed off to destination object stores in near real time with similarly fine granularity, such that processing can proceed until termination with full utilization. The system offers the efficie...

  13. Computer vision system: a tool for evaluating the quality of wheat in a grain tank

    Minkin, Uryi Igorevish; Panchenko, Aleksei Vladimirovich; Shkanaev, Aleksandr Yurievich; Konovalenko, Ivan Andreevich; Putintsev, Dmitry Nikolaevich; Sadekov, Rinat Nailevish

    2018-04-01

    The paper describes a technology that allows for automatizing the process of evaluating the grain quality in a grain tank of a combine harvester. Special recognition algorithm analyzes photographic images taken by the camera, and that provides automatic estimates of the total mass fraction of broken grains and the presence of non-grains. The paper also presents the operating details of the tank prototype as well as it defines the accuracy of the algorithms designed.

  14. Anaerobic digestion of grain stillage at high organic loading rates in three different reactor systems

    Schmidt, Thomas; Pröter, Jürgen; Scholwin, Frank; Nelles, Michael

    2013-01-01

    In this study the anaerobic digestion of grain stillage in three different reactor systems (continuous stirred tank reactor, anaerobic sequencing batch reactor, fixed bed reactor) with and without immobilization of microorganisms was investigated to evaluate the performance during increase of the organic loading rate (OLR) from 1 to 10 g of volatile solids (VS) per liter reactor volume and day and decrease of the hydraulic retention time (HRT) from 40 to 6 days. No significant differences have been observed between the performances of the three examined reactor systems. The changes in OLR and HRT caused a reduction of the specific biogas production (SBP) of about 25% from about 650 to 550 L kg −1 of VS but would also diminish the necessary digester volume and investment costs of about 75% compared to the state of the art. -- Highlights: ► It was shown that without immobilization of microorganisms low HRT's are possible. ► No significant differences have been observed between different digester designs. ► Trace element supplementation is obligatory with grain stillage as substrate

  15. [Grain Size Distribution Characteristics of Suspended Particulate Matter as Influenced by the Apparent Pollution in the Eutrophic Urban Landscape Water Body].

    Gong, Dan-yan; Pan, Yang; Huang, Yong; Bao, Wei; Li, Qian-qian

    2016-03-15

    Grain size distribution characteristics of suspended particulate matter (SPM) reflects the apparent polluted condition of the urban landscape water. In order to explore the internal relationship between the eutrophication of urban landscape water's apparent pollution and grain size distribution of SPM, and its influencing factors, this paper selected five representative sampling sites in Feng Jin River which is a typical eutrophication river in Suzhou City, measured the grain size distribution of SPM, sensation pollution index (SPI) and water quality index, and analyzed their correlation. The results showed that: The rich nutrient water possessed a similar characteristics in grain size distribution. The grain size distribution of SPM in water was multimodal, and the the peak position was roughly the same; the grain size distribution of SPM was composed by multiple components. It could be roughly divided into six parts with the particle size range of every group being 516 µm. The component III was superior (with an average volume fraction of 38.3%-43.2%), and its volume fraction had a significant positive relation with the SPI value and the Chl-a content. The increase of component III volume fraction was the reflection of particle size's result of increasing SPI value. The increase of component III volume fraction was mainly derived from the increasing algal content. The volume fraction of group IV + group VI + group V was significantly higher under the condition of exogenous enter. When there was no exogenous component, the volume fraction of group IV + group VI + group V had a significant negative correlation with SPI value; when there were exogenous components, the volume fraction of group IV + group VI + group V had a weak positive correlation with SPI value, but the correlation did not reach a significant level. Environmental factors (Fv/Fm and DO) and exogenous factors had an influence by functioning on the algal content which signified the polluted material

  16. Simulating of Top-Cross system for enhancement of antioxidants in maize grain

    Jelena Vancetovic

    2014-04-01

    Full Text Available Blue maize (Zea mays L. is grown for its high content of antioxidants. Conversion of yellow and white to blue maize is time consuming because several genes affect blue color. After each backcross selfing is needed for color to be expressed. In order to overcome the problem of time and effort needed for conversion to blue kernel color, we have set a pilot experiment simulating a Top-cross system for increasing antioxidants in maize grain. The idea is to alternately sow six rows of sterile standard quality hybrid and two rows of blue maize in commercial production. Five commercial ZP hybrids were crossed with a blue pop-corn population. Xenia effect caused by cross-pollination produced blue grain on all hybrids in the same year. Chemical analyses of the grains of five selfed original hybrids, five cross-pollinated hybrids and selfed blue popcorn pollinator were performed. Cross-fertilization with blue popcorn had different impact on antioxidant capacity and phytonutrients, increasing them significantly in some but not all cross-pollinated hybrids. Popcorn blue pollinator had higher values for all the analyzed traits than either selfed or cross-pollinated hybrids. Selfed vs. pollinated hybrids showed significant difference for total antioxidant capacity (p<0.1, total phenolics and total yellow pigments (p<0.01, with the increase of total phenolics and decrease of total yellow pigments in pollinated ones. Total flavonoids showed a little non-significant decrease in pollinated hybrids, while total anthocyanins were not detected in selfed yellow hybrids. Blue maize obtained this way has shown good potential for growing high quality phytonutrient genotypes.

  17. Thermal transfer and apparent-dose distributions in poorly bleached mortar samples: results from single grains and small aliquots of quartz

    Jain, M.; Thomsen, K.J.; Boetter-Jensen, L.; Urray, A.S.

    2004-01-01

    In the assessment of doses received from a nuclear accident, considerable attention has been paid to retrospective dosimetry using the optically stimulated luminescence (OSL) of heated materials such as bricks and tiles. quartz extracted from these artefacts was heated during manufacture; this process releases all the prior trapped charge and simultaneously sensitises he quartz. Unfortunately unheated materials such as mortar and concrete are ore common in industrial sites and particularly in nuclear installations. These materials are usually exposed to daylight during quarrying and construction, but in general this exposure is insufficient to completely empty (bleach) any geological trapped charge. This leads to a distribution of apparent doses in the sample at the time of construction with only some (if ny) grains exposed to sufficient light to be considered well bleached for SL dosimetry. The challenge in using such materials as retrospective dosemeters is in identifying these well-bleached grains when an accident dose as been superimposed on the original dose distribution. We investigate here, sing OSL, the background dose in three different mortar samples: render, whitewash and inner wall plaster from a building built in 1964. These samples re found to be both poorly bleached and weakly sensitive (only 0.3% of rains giving a detectable dose response). We study thermal transfer in ingle grains of quartz, investigate the grain-size dependence of bleaching n the size range 90-300 μm and compare the dose-distributions obtained rom small aliquots and single-grain procedures. A comparison of three different methods viz. (a) first 5%, (b) probability plot and (c) comparison f internal and external uncertainties, is made for equivalent dose estimation. The results have implications for accident dosimetry, archaeological studies and dating of poorly bleached sediments

  18. Distributed simulation of large computer systems

    Marzolla, M.

    2001-01-01

    Sequential simulation of large complex physical systems is often regarded as a computationally expensive task. In order to speed-up complex discrete-event simulations, the paradigm of Parallel and Distributed Discrete Event Simulation (PDES) has been introduced since the late 70s. The authors analyze the applicability of PDES to the modeling and analysis of large computer system; such systems are increasingly common in the area of High Energy and Nuclear Physics, because many modern experiments make use of large 'compute farms'. Some feasibility tests have been performed on a prototype distributed simulator

  19. Distributed Database Management Systems A Practical Approach

    Rahimi, Saeed K

    2010-01-01

    This book addresses issues related to managing data across a distributed database system. It is unique because it covers traditional database theory and current research, explaining the difficulties in providing a unified user interface and global data dictionary. The book gives implementers guidance on hiding discrepancies across systems and creating the illusion of a single repository for users. It also includes three sample frameworksâ€"implemented using J2SE with JMS, J2EE, and Microsoft .Netâ€"that readers can use to learn how to implement a distributed database management system. IT and

  20. Distributed expert systems for nuclear reactor control

    Otaduy, P.J.

    1992-01-01

    A network of distributed expert systems is the heart of a prototype supervisory control architecture developed at the Oak Ridge National Laboratory (ORNL) for an advanced multimodular reactor. Eight expert systems encode knowledge on signal acquisition, diagnostics, safeguards, and control strategies in a hybrid rule-based, multiprocessing and object-oriented distributed computing environment. An interactive simulation of a power block consisting of three reactors and one turbine provides a realistic, testbed for performance analysis of the integrated control system in real-time. Implementation details and representative reactor transients are discussed

  1. A Case Study on Distributed Antenna Systems

    Sørensen, Troels Bundgaard

    2007-01-01

    Passive distributed antenna systems (DASs) consisting of distributed feeder lines or single point antennas are now often installed in large office buildings where they provide efficient coverage throughout the building. More sophisticated DASs with intelligent reuse and the ability to adapt...... is described in terms of algorithms for power allocation and access port assignment, as well as algorithms for (dynamic) channel assignment. After an outline of simulation assumptions, system capacity comparisons are given between the adaptive DAS and a system with fixed channel and access port assignment...

  2. The evolution of a distributed operating system

    van Renesse, Robbert; Tanenbaum, Andrew S.; Mullender, Sape J.; Schröder-Preikschat, Wolfgang; Zimmer, Wolfgang

    AMOEBA is a research project to build a true distributed operating system using the object model. Under the COST11-ter MANDIS project this work was extended to cover wide-area networks. Besides describing the system, this paper discusses the successive versions in the implementation of its model,

  3. Distilled Water Distribution Systems. Laboratory Design Notes.

    Sell, J.C.

    Factors concerning water distribution systems, including an evaluation of materials and a recommendation of materials best suited for service in typical facilities are discussed. Several installations are discussed in an effort to bring out typical features in selected applications. The following system types are included--(1) industrial…

  4. PFS: a distributed and customizable file system

    Bosch, H.G.P.; Mullender, Sape J.

    1996-01-01

    In this paper we present our ongoing work on the Pegasus File System (PFS), a distributed and customizable file system that can be used for off-line file system experiments and on-line file system storage. PFS is best described as an object-oriented component library from which either a true file system or a file-system simulator can be constructed. Each of the components in the library is easily replaced by another implementation to accommodate a wide range of applications.

  5. Distributed Monitoring System Based on ICINGA

    Haen, C; Neufeld, N

    2011-01-01

    The LHCb online system relies on a large and heterogeneous I.T. infrastructure : it comprises more than 2000 servers and embedded systems and more than 200 network devices. While for the control and monitoring of detectors, PLCs, and readout boards an industry standard SCADA system PVSSII has been put in production, we use a low level monitoring system to monitor the control infrastructure itself. While our previous system was based on a single central NAGIOS server, our current system uses a distributed ICINGA infrastructure.

  6. Synchronization in Quantum Key Distribution Systems

    Anton Pljonkin

    2017-10-01

    Full Text Available In the description of quantum key distribution systems, much attention is paid to the operation of quantum cryptography protocols. The main problem is the insufficient study of the synchronization process of quantum key distribution systems. This paper contains a general description of quantum cryptography principles. A two-line fiber-optic quantum key distribution system with phase coding of photon states in transceiver and coding station synchronization mode was examined. A quantum key distribution system was built on the basis of the scheme with automatic compensation of polarization mode distortions. Single-photon avalanche diodes were used as optical radiation detecting devices. It was estimated how the parameters used in quantum key distribution systems of optical detectors affect the detection of the time frame with attenuated optical pulse in synchronization mode with respect to its probabilistic and time-domain characteristics. A design method was given for the process that detects the time frame that includes an optical pulse during synchronization. This paper describes the main quantum communication channel attack methods by removing a portion of optical emission. This paper describes the developed synchronization algorithm that takes into account the time required to restore the photodetector’s operation state after the photon has been registered during synchronization. The computer simulation results of the developed synchronization algorithm were analyzed. The efficiency of the developed algorithm with respect to synchronization process protection from unauthorized gathering of optical emission is demonstrated herein.

  7. Making the Public Distribution System Work

    Debarshi Das

    2014-02-01

    Full Text Available Drawing on empirical observations of operation of public distribution system in different states of India, the paper constructs a preliminary game theoretic model. It argues that an effective public distribution must be as universal as possible, delivery mechanism of fair price shops should be re- formed, they should be make them commercially viable and that special attention should be paid to PDS at times of high food inflation.

  8. Electricity distribution management Smart Grid system model

    Wiesław Nowak

    2012-06-01

    Full Text Available This paper presents issues concerning the implementation of Smart Grid solutions in a real distribution network. The main components possible to quick implementation were presented. Realization of these ideas should bring tangible benefi ts to both customers and distribution system operators. Moreover the paper shows selected research results which examine proposed solutions in area of improving supply reliability and reducing energy losses in analysed network.

  9. Control of distributed systems : tutorial and overview

    van Schuppen, J. H.; Boutin, O.; Kempker, P.L.; Komenda, Jan; Masopust, Tomáš; Pambakian, N.; Ran, A.C.M.

    2011-01-01

    Roč. 17, 5-6 (2011), s. 579-602 ISSN 0947-3580 R&D Projects: GA ČR(CZ) GAP103/11/0517; GA ČR(CZ) GPP202/11/P028 Institutional research plan: CEZ:AV0Z10190503 Keywords : distributed system * coordination control * hierarchical control * distributed control * distributed control with communication Subject RIV: BA - General Mathematics Impact factor: 0.817, year: 2011 http://ejc.revuesonline.com/article.jsp?articleId=16873

  10. Design of a distributed control system

    Bilous, O [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    A digital computer is used to evaluate various pressure control systems for a gaseous diffusion cascade. This is an example of a distributed feedback control system. The paper gives a brief discussion of similar cases of distributed or stage wise control systems, which may occur in multiple temperature control of chemical processes. (author) [French] Une calculatrice digitale est utilisee pour evaluer divers systemes de controle de pression pour une cascade de diffusion gazeuse. C'est un exemple de systeme de controle a reaction distribue. Le rapport presente une breve discussion de cas semblables de systemes de controle distribues ou en etage, qui peuvent se presenter dans de nombreux controles de temperature de reactions chimiques. (auteur)

  11. EGSNRC distributed systems on commercial network

    McCormack, J.M.

    2001-01-01

    Full text: EGSnrc is a Monte Carlo based simulation program for determining radiation dose distribution within a body. Computational times are large as each individual photon path must be calculated and every energy absorption event stored. This means that EGSnrc lends itself to distributed processing, as each photon is independent of the next, and code is included within the package to enable this. EGSnrc is currently only supported on Unix based computer systems, whilst the department has ∼45 Pentium II and III class workstations all operating under Windows NT within a Novell network. This investigation demonstrates the capability of a windows based system to perform distributed computation of EGSnrc. All Unix scripts were modified to work as one single Windows NT batch file. The source code was then compiled using the gcc C compiler (a Windows NT version of the Unix compiler) without modification of the underlying source code. A small Visual Basic program was used as a trigger to start the simulation as a Windows NT service, with Novell Z.E.N. Works to distribute the trigger code to each system. When a trigger was received, the computer began a simulation as a low priority task in such a way that the user did not see anything on the screen, and so the simulation did not slow down the general running of the computer. The results were then transferred to the network, and collated on a central computer. As an unattended system, a calculation can start within 15 minutes of any desired time, calculate the desired results, and return the results for collation. This demonstrated effectively a distributed Windows NT TM EGSnrc system. Simulations must be chosen carefully to ensure that each photon can be considered independent, as photon histories do not get distributed. Each system that was used for EGSnrc was required to be capable of running the full EGSnrc simulation on its own EGSnrc stored the entire result array locally, so a large, high-resolution body required

  12. Grain refinement control in TIG arc welding

    Iceland, W. F.; Whiffen, E. L. (Inventor)

    1975-01-01

    A method for controlling grain size and weld puddle agitation in a tungsten electrode inert gas welding system to produce fine, even grain size and distribution is disclosed. In the method the frequency of dc welding voltage pulses supplied to the welding electrode is varied over a preselected frequency range and the arc gas voltage is monitored. At some frequency in the preselected range the arc gas voltage will pass through a maximum. By maintaining the operating frequency of the system at this value, maximum weld puddle agitation and fine grain structure are produced.

  13. Neutral particle beam distributed data acquisition system

    Daly, R.T.; Kraimer, M.R.; Novick, A.H.

    1987-01-01

    A distributed data acquisition system has been designed to support experiments at the Argonne Neutral Particle Beam Accelerator. The system uses a host VAXstation II/GPX computer acting as an experimenter's station linked via Ethernet with multiple MicroVAX IIs and rtVAXs dedicated to acquiring data and controlling hardware at remote sites. This paper describes the hardware design of the system, the applications support software on the host and target computers, and the real-time performance

  14. An Application for the Improvement of the Transportation System of the Flour in a Grain Mill using "PID Compact"

    Eugen Răduca

    2016-10-01

    Full Text Available The paper presents an application based on a PLC Simatic S7-1200, using the "PID_Compact" logical function, which can be used for the improvement of control systems. We also present a practical application: a system for the improvement of the transportation system of the flour in a grain mill using "PID Compact" .

  15. A Distributed Intelligent System for Emergency Convoy

    Mohammed Benalla

    2016-09-01

    Full Text Available The general problem that guides this research is the ability to design a distributed intelligent system for guiding the emergency convoys; a solution that will be based on a group of agents and on the analysis of traffic in order to generate collective functional response. It fits into the broader issue of Distributed Artificial System (DAI, which is to operate a cooperatively computer agent into multi-agents system (MAS. This article describes conceptually two fundamental questions of emergency convoys. The first question is dedicated to find a response to the traffic situation (i.e. fluid way, while the second is devoted to the convoy orientation; while putting the point on the distributed and cooperative resolution for the general problem.

  16. The ATLAS Distributed Data Management System & Databases

    Garonne, V; The ATLAS collaboration; Barisits, M; Beermann, T; Vigne, R; Serfon, C

    2013-01-01

    The ATLAS Distributed Data Management (DDM) System is responsible for the global management of petabytes of high energy physics data. The current system, DQ2, has a critical dependency on Relational Database Management Systems (RDBMS), like Oracle. RDBMS are well-suited to enforcing data integrity in online transaction processing applications, however, concerns have been raised about the scalability of its data warehouse-like workload. In particular, analysis of archived data or aggregation of transactional data for summary purposes is problematic. Therefore, we have evaluated new approaches to handle vast amounts of data. We have investigated a class of database technologies commonly referred to as NoSQL databases. This includes distributed filesystems, like HDFS, that support parallel execution of computational tasks on distributed data, as well as schema-less approaches via key-value stores, like HBase. In this talk we will describe our use cases in ATLAS, share our experiences with various databases used ...

  17. Cardea: Dynamic Access Control in Distributed Systems

    Lepro, Rebekah

    2004-01-01

    Modern authorization systems span domains of administration, rely on many different authentication sources, and manage complex attributes as part of the authorization process. This . paper presents Cardea, a distributed system that facilitates dynamic access control, as a valuable piece of an inter-operable authorization framework. First, the authorization model employed in Cardea and its functionality goals are examined. Next, critical features of the system architecture and its handling of the authorization process are then examined. Then the S A M L and XACML standards, as incorporated into the system, are analyzed. Finally, the future directions of this project are outlined and connection points with general components of an authorization system are highlighted.

  18. Formation of multiple stoichiometric phases in binary systems by combined bulk and grain boundary diffusion: Experiments and model

    Svoboda, J.; Fischer, F.D.; Schillinger, W.

    2013-01-01

    The thermodynamic extremal principle has been used by the authors to treat the evolution of binary and multicomponent systems under the assumption that all phases are nearly stoichiometric. Up to now only bulk diffusion has been taken into account. The concept is now extended to combined bulk and grain boundary diffusion possible in each newly formed phase. The grains are approximated by cylinders allowing interface diffusion along the top and bottom of the grains and grain boundary diffusion along the mantle with different interface/grain boundary diffusion coefficients. A consistent analysis yields an effective diffusion coefficient taking into account the combined interface/grain boundary and bulk diffusion of each individual component. The current concept is applied to the Cu–Sn couple which has been studied by a number of researchers. The results of simulations are compared with experiments at 200 °C on solid systems reported in the literature as well as with our experiments at 250 °C with liquid Sn.

  19. Concurrency control in distributed database systems

    Cellary, W; Gelenbe, E

    1989-01-01

    Distributed Database Systems (DDBS) may be defined as integrated database systems composed of autonomous local databases, geographically distributed and interconnected by a computer network.The purpose of this monograph is to present DDBS concurrency control algorithms and their related performance issues. The most recent results have been taken into consideration. A detailed analysis and selection of these results has been made so as to include those which will promote applications and progress in the field. The application of the methods and algorithms presented is not limited to DDBSs but a

  20. Distributed formation tracking using local coordinate systems

    Yang, Qingkai; Cao, Ming; Garcia de Marina, Hector

    2018-01-01

    This paper studies the formation tracking problem for multi-agent systems, for which a distributed estimator–controller scheme is designed relying only on the agents’ local coordinate systems such that the centroid of the controlled formation tracks a given trajectory. By introducing a gradient...... descent term into the estimator, the explicit knowledge of the bound of the agents’ speed is not necessary in contrast to existing works, and each agent is able to compute the centroid of the whole formation in finite time. Then, based on the centroid estimation, a distributed control algorithm...

  1. Converters for Distributed Power Generation Systems

    Blaabjerg, Frede; Yang, Yongheng

    2015-01-01

    Power electronics technology has become the enabling technology for the integration of distributed power generation systems (DPGS) such as offshore wind turbine power systems and commercial photovoltaic power plants. Depending on the applications, a vast array of DPGS-based power converter...... topologies has been developed and more are coming into the market in order to achieve an efficient and reliable power conversion from the renewables. In addition, stringent demands from both the distribution system operators and the consumers have been imposed on the renewable-based DPGS. This article...... presents an overview of the power converters for the DPGS, mainly based on wind turbine systems and photovoltaic systems, covering a wide range of applications. Moreover, the modulation schemes and interfacing power filters for the power converters are also exemplified. Finally, the general control...

  2. DC Home Appliances for DC Distribution System

    MUHAMMAD KAMRAN

    2017-10-01

    Full Text Available This paper strengthens the idea of DC distribution system for DC microgrid consisting of a building of 50 apartments. Since the war of currents AC system has been dominant because of the paucity of research in the protection of the DC system. Now with the advance research in power electronics material and components, generation of electricity is inherently DC as by solar PV, fuel cell and thermoelectric generator that eliminates the rectification process. Transformers are replaced by the power electronics buck-boost converters. DC circuit breakers have solved the protection problems for both DC transmission and distribution system. In this paper 308V DC microgrid is proposed and home appliances (DC internal are modified to operate on 48V DC from DC distribution line. Instead of using universal and induction motors in rotary appliances, BLDC (Brushless DC motors are proposed that are highly efficient with minimum electro-mechanical and no commutation losses. Proposed DC system reduces the power conversion stages, hence diminishes the associated power losses and standby losses that boost the overall system efficiency. So in view of all this a conventional AC system can be replaced by a DC system that has many advantages by cost as well as by performance

  3. Adaptive intelligent power systems: Active distribution networks

    McDonald, Jim

    2008-01-01

    Electricity networks are extensive and well established. They form a key part of the infrastructure that supports industrialised society. These networks are moving from a period of stability to a time of potentially major transition, driven by a need for old equipment to be replaced, by government policy commitments to cleaner and renewable sources of electricity generation, and by change in the power industry. This paper looks at moves towards active distribution networks. The novel transmission and distribution systems of the future will challenge today's system designs. They will cope with variable voltages and frequencies, and will offer more flexible, sustainable options. Intelligent power networks will need innovation in several key areas of information technology. Active control of flexible, large-scale electrical power systems is required. Protection and control systems will have to react to faults and unusual transient behaviour and ensure recovery after such events. Real-time network simulation and performance analysis will be needed to provide decision support for system operators, and the inputs to energy and distribution management systems. Advanced sensors and measurement will be used to achieve higher degrees of network automation and better system control, while pervasive communications will allow networks to be reconfigured by intelligent systems

  4. Electric distribution systems and embedded generation capacity

    Calderaro, V.; Galdi, V.; Piccolo, A.; Siano, P.

    2006-01-01

    The main policy issues of European States are sustainable energy supply promotion and liberalization of energy markets, which introduced market competition in electricity production and created support mechanisms to encourage renewable electricity production and consumption. As a result of liberalization, any generator, including small-scale and renewable energy based units, can sell electricity on the free market. In order to meet future sustainability targets, connection of a higher number of Distributed Generation (DG) units to the electrical power system is expected, requiring changes in the design and operation of distribution electricity systems, as well as changes in electricity network regulation. In order to assist distribution system operators in planning and managing DG connections and in maximizing DG penetration and renewable sources exploitation, this paper proposed a reconfiguration methodology based on a Genetic Algorithm (GA), that was tested on a 70-bus system with DG units. The simulation results confirmed that the methodology represents a suitable tool for distribution system operators when dealing with DG capacity expansion and power loss issues, providing information regarding the potential penetration network-wide and allowing maximum exploitation of renewable generation. 35 refs., 4 tabs., 6 figs

  5. Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil

    Cintia F. Barreto

    2012-09-01

    Full Text Available Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.Com objetivo de investigar a deposição dos grãos de pólen e esporos na Baía de Guanabara, Estado do Rio de Janeiro, 61 amostras de sedimentos superficiais foram analisadas. Os resultados mostraram que a deposição atual dos palinomorfos nos sedimentos superficiais da Baía de Guanabara representa a vegetação regional de sua bacia hidrográfica. A distribuição diferencial dos palinomorfos seguiu um padrão influenciado pela batimetria, velocidade das corretes de marés, descarga dos numerosos rios e pela atividade humana. A dominância dos taxa representantes da Vegetação Campestre reflete as mudanças da flora original causadas por intensas atividades humanas na região. A presença contínua e a grande riqueza de tipos polínicos da Floresta Ombrófila nas amostras, indica que a área fonte pode ser a vegetação das bordas dos rios do setor oeste da Baía, onde a vegetação de mangue está sendo preservada. A

  6. Intelligent Control and Operation of Distribution System

    Bhattarai, Bishnu Prasad

    methodology to ensure efficient control and operation of the future distribution networks. The major scientific challenge is thus to develop control models and strategies to coordinate responses from widely distributed controllable loads and local generations. Detailed models of key Smart Grid (SG) elements...... in this direction but also benefit distribution system operators in the planning and development of the distribution network. The major contributions of this work are described in the following four stages: In the first stage, an intelligent Demand Response (DR) control architecture is developed for coordinating...... the key SG actors, namely consumers, network operators, aggregators, and electricity market entities. A key intent of the architecture is to facilitate market participation of residential consumers and prosumers. A Hierarchical Control Architecture (HCA) having primary, secondary, and tertiary control...

  7. 3D Microstructural Characterization of Uranium Oxide as a Surrogate Nuclear Fuel: Effect of Oxygen Stoichiometry on Grain Boundary Distributions

    Rudman, K. [Arizona State Univ., Tempe, AZ (United States); Dickerson, P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Byler, Darrin David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Peralta, P. [Arizona State Univ., Tempe, AZ (United States); Lim, H. [Arizona State Univ., Tempe, AZ (United States); McDonald, R. [Arizona State Univ., Tempe, AZ (United States); Dickerson, R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mcclellan, Kenneth James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-06

    The initial microstructure of an oxide fuel can play a key role in its performance. At low burn-ups, the diffusion of fission products can depend strongly on grain size and grain boundary (GB) characteristics, which in turn depend on processing conditions and oxygen stoichiometry. Serial sectioning techniques using Focused Ion Beam were developed to obtain Electron Backscatter Diffraction (EBSD) data for depleted UO2 pellets that were processed to obtain 3 different oxygen stoichiometries. The EBSD data were used to create 3D microstructure reconstructions and to gather statistical information on the grain and GB crystallography, with emphasis on identifying the character (twist, tilt, mixed) for GBs that meet the Coincident Site Lattice (CSL) criterion as well as GBs with the most common misorientation angles. Data on dihedral angles at triple points were also collected. The results were compared across different samples to understand effects of oxygen content on microstructure evolution.

  8. Coarse-grained sediment delivery and distribution in the Holocene Santa Monica Basin, California: Implications for evaluating source-to-sink flux at millennial time scales

    Romans, B.W.; Normark, W.R.; McGann, M.M.; Covault, J.A.; Graham, S.A.

    2009-01-01

    Utilizing accumulations of coarse-grained terrigenous sediment from deep-marine basins to evaluate the relative contributions of and history of controls on sediment flux through a source-to-sink system has been difficult as a result of limited knowledge of event timing. In this study, six new radiocarbon (14C) dates are integrated with five previously published dates that have been recalibrated from a 12.5-m-thick turbidite section from Ocean Drilling Program (ODP) Site 1015 in Santa Monica Basin, offshore California. This borehole is tied to high-resolution seismic-reflection profiles that cover an 1100 km2 area of the middle and lower Hueneme submarine fan and most of the basin plain. The resulting stratigraphic framework provides the highest temporal resolution for a thick-bedded Holocene turbidite succession to date, permitting an evaluation of source-to-sink controls at millennial (1000 yr) scales. The depositional history from 7 ka to present indicates that the recurrence interval for large turbidity-current events is relatively constant (300-360 yr), but the volume of sediment deposited on the fan and in the basin plain has increased by a factor of 2 over this period. Moreover, the amount of sand per event on the basin plain during the same interval has increased by a factor of 7. Maps of sediment distribution derived from correlation of seismic-reflection profiles indicate that this trend cannot be attributed exclusively to autogenic processes (e.g., progradation of depocenters). The observed variability in sediment accumulation rates is thus largely controlled by allogenic factors, including: (1) increased discharge of Santa Clara River as a result of increased magnitude and frequency of El Ni??o-Southern Oscillation (ENSO) events from ca. 2 ka to present, (2) an apparent change in routing of coarse-grained sediment within the staging area at ca. 3 ka (i.e., from direct river input to indirect, littoral cell input into Hueneme submarine canyon), and (3

  9. Wireless distributed functional electrical stimulation system

    Jovičić Nenad S

    2012-08-01

    Full Text Available Abstract Background The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. Methods The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software. Results The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers. One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. Conclusions The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  10. Wireless distributed functional electrical stimulation system.

    Jovičić, Nenad S; Saranovac, Lazar V; Popović, Dejan B

    2012-08-09

    The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype's software. The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers). One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  11. Predictive coarse-graining

    Schöberl, Markus, E-mail: m.schoeberl@tum.de [Continuum Mechanics Group, Technical University of Munich, Boltzmannstraße 15, 85748 Garching (Germany); Zabaras, Nicholas [Institute for Advanced Study, Technical University of Munich, Lichtenbergstraße 2a, 85748 Garching (Germany); Department of Aerospace and Mechanical Engineering, University of Notre Dame, 365 Fitzpatrick Hall, Notre Dame, IN 46556 (United States); Koutsourelakis, Phaedon-Stelios [Continuum Mechanics Group, Technical University of Munich, Boltzmannstraße 15, 85748 Garching (Germany)

    2017-03-15

    We propose a data-driven, coarse-graining formulation in the context of equilibrium statistical mechanics. In contrast to existing techniques which are based on a fine-to-coarse map, we adopt the opposite strategy by prescribing a probabilistic coarse-to-fine map. This corresponds to a directed probabilistic model where the coarse variables play the role of latent generators of the fine scale (all-atom) data. From an information-theoretic perspective, the framework proposed provides an improvement upon the relative entropy method and is capable of quantifying the uncertainty due to the information loss that unavoidably takes place during the coarse-graining process. Furthermore, it can be readily extended to a fully Bayesian model where various sources of uncertainties are reflected in the posterior of the model parameters. The latter can be used to produce not only point estimates of fine-scale reconstructions or macroscopic observables, but more importantly, predictive posterior distributions on these quantities. Predictive posterior distributions reflect the confidence of the model as a function of the amount of data and the level of coarse-graining. The issues of model complexity and model selection are seamlessly addressed by employing a hierarchical prior that favors the discovery of sparse solutions, revealing the most prominent features in the coarse-grained model. A flexible and parallelizable Monte Carlo – Expectation–Maximization (MC-EM) scheme is proposed for carrying out inference and learning tasks. A comparative assessment of the proposed methodology is presented for a lattice spin system and the SPC/E water model.

  12. Deceit: A flexible distributed file system

    Siegel, Alex; Birman, Kenneth; Marzullo, Keith

    1989-01-01

    Deceit, a distributed file system (DFS) being developed at Cornell, focuses on flexible file semantics in relation to efficiency, scalability, and reliability. Deceit servers are interchangeable and collectively provide the illusion of a single, large server machine to any clients of the Deceit service. Non-volatile replicas of each file are stored on a subset of the file servers. The user is able to set parameters on a file to achieve different levels of availability, performance, and one-copy serializability. Deceit also supports a file version control mechanism. In contrast with many recent DFS efforts, Deceit can behave like a plain Sun Network File System (NFS) server and can be used by any NFS client without modifying any client software. The current Deceit prototype uses the ISIS Distributed Programming Environment for all communication and process group management, an approach that reduces system complexity and increases system robustness.

  13. Distributed control system for the FMIT

    Johnson, J.A.; Machen, D.R.; Suyama, R.M.

    1979-01-01

    The control system for the Fusion Materials Irradiation Test (FMIT) Facility will provide the primary data acquisition, control, and interface components that integrate all of the individual FMIT systems into a functional facility. The control system consists of a distributed computer network, control consoles and instrumentation subsystems. The FMIT Facility will be started, operated and secured from a Central Control Room. All FMIT systems and experimental functions will be monitored from the Central Control Room. The data acquisition and control signals will be handled by a data communications network, which connects dual computers in the Central Control Room to the microcomputers in CAMAC crates near the various subsystems of the facility

  14. Left-forbidding cooperating distributed grammar systems

    Goldefus, F.; Masopust, Tomáš; Meduna, A.

    2010-01-01

    Roč. 411, 40-42 (2010), s. 3661-3667 ISSN 0304-3975 Institutional research plan: CEZ:AV0Z10190503 Keywords : cooperating distributed grammar system * cooperating derivation mode * left-forbidding grammar * generative power * descriptional complexity Subject RIV: BA - General Mathematics Impact factor: 0.838, year: 2010 http://www.sciencedirect.com/science/article/pii/S0304397510003440

  15. Modelling Dynamic Forgetting in Distributed Information Systems

    N.F. Höning (Nicolas); M.C. Schut

    2010-01-01

    htmlabstractWe describe and model a new aspect in the design of distributed information systems. We build upon a previously described problem on the microlevel, which asks how quickly agents should discount (forget) their experience: If they cherish their memories, they can build their reports on

  16. Workflow management in large distributed systems

    Legrand, I; Newman, H; Voicu, R; Dobre, C; Grigoras, C

    2011-01-01

    The MonALISA (Monitoring Agents using a Large Integrated Services Architecture) framework provides a distributed service system capable of controlling and optimizing large-scale, data-intensive applications. An essential part of managing large-scale, distributed data-processing facilities is a monitoring system for computing facilities, storage, networks, and the very large number of applications running on these systems in near realtime. All this monitoring information gathered for all the subsystems is essential for developing the required higher-level services—the components that provide decision support and some degree of automated decisions—and for maintaining and optimizing workflow in large-scale distributed systems. These management and global optimization functions are performed by higher-level agent-based services. We present several applications of MonALISA's higher-level services including optimized dynamic routing, control, data-transfer scheduling, distributed job scheduling, dynamic allocation of storage resource to running jobs and automated management of remote services among a large set of grid facilities.

  17. Wind Power in Electrical Distribution Systems

    Chen, Zhe

    2013-01-01

    Recent years, wind power is experiencing a rapid growth, large number of wind turbines/wind farms have been installed and connected to power systems. In addition to the large centralised wind farms connected to transmission grids, many distributed wind turbines and wind farms are operated as dist...

  18. Gradient remediability in linear distributed parabolic systems ...

    The aim of this paper is the introduction of a new concept that concerned the analysis of a large class of distributed parabolic systems. It is the general concept of gradient remediability. More precisely, we study with respect to the gradient observation, the existence of an input operator (gradient efficient actuators) ensuring ...

  19. Boundary feedback stabilization of distributed parameter systems

    Pedersen, Michael

    1988-01-01

    The author introduces the method of pseudo-differential stabilization. He notes that the theory of pseudo-differential boundary operators is a fruitful approach to problems arising in control and stabilization theory of distributed-parameter systems. The basic pseudo-differential calculus can...

  20. Distribution system reliability evaluation using credibility theory

    Xufeng Xu, Joydeep Mitra

    have found that credibility theory, which broadens the scope of fuzzy set theory, is an effective tool for representing fuzzy events, and have developed a theoretical .... Based on the status of switches, the distribution system can be divided into multiple SPSS, which are connected with tie switches. For example, SPSS.

  1. Trading Freshness for Performance in Distributed Systems

    2014-12-01

    C. Hsieh, Deborah A. Wallach, Mike Burrows , Tushar Chandra, Andrew Fikes, and Robert E. Gruber. BigTable: A distributed storage system for structured... Larry Brilliant. Detecting influenza epidemics using search engine query data. Nature, pages 1012–1014, February 2009. 3.2 Goetz Graefe. Write

  2. Workflow management in large distributed systems

    Legrand, I.; Newman, H.; Voicu, R.; Dobre, C.; Grigoras, C.

    2011-12-01

    The MonALISA (Monitoring Agents using a Large Integrated Services Architecture) framework provides a distributed service system capable of controlling and optimizing large-scale, data-intensive applications. An essential part of managing large-scale, distributed data-processing facilities is a monitoring system for computing facilities, storage, networks, and the very large number of applications running on these systems in near realtime. All this monitoring information gathered for all the subsystems is essential for developing the required higher-level services—the components that provide decision support and some degree of automated decisions—and for maintaining and optimizing workflow in large-scale distributed systems. These management and global optimization functions are performed by higher-level agent-based services. We present several applications of MonALISA's higher-level services including optimized dynamic routing, control, data-transfer scheduling, distributed job scheduling, dynamic allocation of storage resource to running jobs and automated management of remote services among a large set of grid facilities.

  3. Mansion, A Distributed Multi-Agent System

    van t Noordende, G.; Brazier, F.M.; Tanenbaum, A.S.

    2001-01-01

    In this position summary we present work in progress on a worldwide, scalable multi-agent system, based on a paradigm of hyperlinked rooms. The framework offers facilities for managing distribution, security and mobility aspects for both active elements (agents) and passive elements (objects) in the

  4. Programming model for distributed intelligent systems

    Sztipanovits, J.; Biegl, C.; Karsai, G.; Bogunovic, N.; Purves, B.; Williams, R.; Christiansen, T.

    1988-01-01

    A programming model and architecture which was developed for the design and implementation of complex, heterogeneous measurement and control systems is described. The Multigraph Architecture integrates artificial intelligence techniques with conventional software technologies, offers a unified framework for distributed and shared memory based parallel computational models and supports multiple programming paradigms. The system can be implemented on different hardware architectures and can be adapted to strongly different applications.

  5. The new bank note distribution system

    Gerrit Bilkes

    1997-01-01

    In this article, the author outlines the recent changes made to the way Canada's bank notes are distributed. The new system allows financial institutions to exchange notes directly with one another at designated points across the country, rather than through Bank of Canada agencies, as was previously the case. The institutions communicate with the Bank of Canada through a computerized inventory-management system. Two Bank of Canada operations centres monitor note quality and supply new notes ...

  6. Planning and Optimization Methods for Active Distribution Systems

    Abbey, Chad; Baitch, Alex; Bak-Jensen, Birgitte

    distribution planning. Active distribution networks (ADNs) have systems in place to control a combination of distributed energy resources (DERs), defined as generators, loads and storage. With these systems in place, the AND becomes an Active Distribution System (ADS). Distribution system operators (DSOs) have...

  7. Role and distribution of strontium during the dissolving and grain refining process of AlSi7Mg alloy's structure

    Moldovan, P.; Popescu, G.; Zsigmond, M.; Apostolescu, I. [Universitatea Politehnica, Bucharest (Romania)

    2002-07-01

    The aim of this paper is the study of the modification of AlSi7Mg alloy with two types of master alloys: AlSr10 wire type and AlSr10 block type, at a temperature of 750 C with different contents of strontium. Due to the applicability of the AlSr10 master alloy wire type, the study was mainly elaborated on the dissolving process of this one. Due to this fact we used a 10 mm diameter wire of AlSr10 master alloy, which was introduced in the melt. After the grain refining process we obtained a sample, which was cut at different heights for a better observation of the alloy structure. We can notice that the grain refining degree is not uniform along the sample. Strontium as a grain refiner equalize the qualities of sodium but is much more efficient and keeps its grain refining properties for a longer period of time. The efficiency of the two types of master alloys was compared by the grain refinement degree of AlSi7Mg alloy function of the distance till the lower part of the casting mould and by determination of the grain refinement degree function of strontium content added. We made a micrographic study of the pieces of the sample and we used an optical microscope (OLYMPUS BX 60M) and the image analyzing system was OMNIMENT EXPRESS. Analyzing the results of this study we can see that the AlSi7Mg alloy grain refining degree doesn't depend too much on the form of the master alloy (if is wire or block) but grain refining time is increased when we use block types of master alloy. Also we can see that the cooling rate has a significant influence on the grain refinement degree. The industrial application of the AlSr master alloys are mainly for the light alloys ingots producers and light alloys casting plant for the obtaining of high quality components required by automotive and aeronautical industry. (orig.)

  8. Next Generation Snow Cover Mapping: Can Future Hyperspectral Satellite Spectrometer Systems Improve Subpixel Snow-covered Area and Grain Size in the Sierra Nevada?

    Hill, R.; Calvin, W. M.; Harpold, A.

    2017-12-01

    Mountain snow storage is the dominant source of water for humans and ecosystems in western North America. Consequently, the spatial distribution of snow-covered area is fundamental to both hydrological, ecological, and climate models. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data were collected along the entire Sierra Nevada mountain range extending from north of Lake Tahoe to south of Mt. Whitney during the 2015 and 2016 snow-covered season. The AVIRIS dataset used in this experiment consists of 224 contiguous spectral channels with wavelengths ranging 400-2500 nanometers at a 15-meter spatial pixel size. Data from the Sierras were acquired on four days: 2/24/15 during a very low snow year, 3/24/16 near maximum snow accumulation, and 5/12/16 and 5/18/16 during snow ablation and snow loss. Building on previous retrieval of subpixel snow-covered area algorithms that take into account varying grain size we present a model that analyzes multiple endmembers of varying snow grain size, vegetation, rock, and soil in segmented regions along the Sierra Nevada to determine snow-cover spatial extent, snow sub-pixel fraction, and approximate grain size. In addition, varying simulated models of the data will compare and contrast the retrieval of current snow products such as MODIS Snow-Covered Area and Grain Size (MODSCAG) and the Airborne Space Observatory (ASO). Specifically, does lower spatial resolution (MODIS), broader resolution bandwidth (MODIS), and limited spectral resolution (ASO) affect snow-cover area and grain size approximations? The implications of our findings will help refine snow mapping products for planned hyperspectral satellite spectrometer systems such as EnMAP (slated to launch in 2019), HISUI (planned for inclusion on the International Space Station in 2018), and HyspIRI (currently under consideration).

  9. The "Family Tree" of Air Distribution Systems

    Nielsen, Peter V.

    2011-01-01

    In this paper all total volume air distribution principles are addressed based on discussions of air flow pattern in a room with heat sources giving a cooling load. The supply and exhaust air openings are considered to have different locations and sizes in the room, and it is possible to show tha...... conditions which are not used for air distribution in general. A number of experiments with different air distribution systems are addressed, and they illustrate the behaviour at the different conditions discussed in the paper....... that all the known types of air distribution systems are interconnected in a “family tree”. The influence of supplied momentum flow versus buoyancy forces is discussed, and geometries for high ventilation effectiveness are indicated as well as geometries for fully mixed flow. The paper will also show......In this paper all total volume air distribution principles are addressed based on discussions of air flow pattern in a room with heat sources giving a cooling load. The supply and exhaust air openings are considered to have different locations and sizes in the room, and it is possible to show...

  10. Design of distributed systems of hydrolithosphere processes management. A synthesis of distributed management systems

    Pershin, I. M.; Pervukhin, D. A.; Ilyushin, Y. V.; Afanaseva, O. V.

    2017-10-01

    The paper considers an important problem of designing distributed systems of hydrolithosphere processes management. The control actions on the hydrolithosphere processes under consideration are implemented by a set of extractive wells. The article shows the method of defining the approximation links for description of the dynamic characteristics of hydrolithosphere processes. The structure of distributed regulators, used in the management systems by the considered processes, is presented. The paper analyses the results of the synthesis of the distributed management system and the results of modelling the closed-loop control system by the parameters of the hydrolithosphere process.

  11. Communication Systems and Study Method for Active Distribution Power systems

    Wei, Mu; Chen, Zhe

    Due to the involvement and evolvement of communication technologies in contemporary power systems, the applications of modern communication technologies in distribution power system are becoming increasingly important. In this paper, the International Organization for Standardization (ISO......) reference seven-layer model of communication systems, and the main communication technologies and protocols on each corresponding layer are introduced. Some newly developed communication techniques, like Ethernet, are discussed with reference to the possible applications in distributed power system....... The suitability of the communication technology to the distribution power system with active renewable energy based generation units is discussed. Subsequently the typical possible communication systems are studied by simulation. In this paper, a novel method of integrating communication system impact into power...

  12. Strongly coupled Coulomb systems with positive dust grains: thermal and UV-induced plasmas

    Samarian, A.A.

    2000-01-01

    Full text: A plasma containing macroscopic dust particles or grains (often referred to as a dusty or colloidal or complex plasma) has the feature that grains may be charged by electron or ion flux or by photo- or thermoelectron emission. Electron emission from a grain surface produces a positive charge; capture of electrons produces the reverse effect making the dust grains negatively charged. Most dusty plasma research is concerned with the ordered dust structures (so-called 'plasma crystal') in glow discharges. The dust grains in these experiments were found to carry a negative charge due to the higher mobility of electrons as compared to ions in the discharge plasma. In recent years, in parallel with the study of the properties of plasma crystals under discharge conditions, attempts to obtain a structure from positively charged dust grains have been made, and structure formation processes for various charging mechanisms, particularly thermoelectron emission and photoemission, have been investigated. In this paper we review the essential features of strongly coupled plasmas with positive dust grains. An ordered structure of CeO 2 grains has been experimentally observed in a combustion products jet. The grains were charged positively and suspended in the plasma flow. Their charge is about 10 3 a and the calculated value of a Coulomb coupling parameter Γ is >10, corresponding to a plasma liquid. The ordered structures of Al 2 O 3 dust grains in propellant combustion products plasma have been observed for the first time. These structures were found in the sheath boundary of condensation region. The obtained data let us estimate the value of parameter Γ =3-40, corresponding to the plasma liquid state. The possibility is studied of the formation of ordered dust grain structures in thermal plasma. The range of the required values of the coupling parameter Γ is calculated using the results of diagnostic measurements carried out in thermal plasma with grains of

  13. Laser spark distribution and ignition system

    Woodruff, Steven [Morgantown, WV; McIntyre, Dustin L [Morgantown, WV

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  14. Distributed systems design using separable communications

    Capel, A.C.; Yan, G.

    1980-01-01

    One of the promises of distributed systems is the ability to design each process function largely independently of the others, and in many cases locate the resulting hardware in close proximity to the application. The communications architecture for such systems should be approached in the same way, using separable communications facilities to meet individual sets of requirements while at the same time reducing the interactions between functions. Where complete physical separation is not feasible and hardware resource sharing is required, the protocols should be designed emphasizing the logical separation of communication paths. This paper discusses the different types of communications for process control applictions and the parameters which need to be characterized in designing separable communications for distributed systems. (auth)

  15. Overview of the ATLAS distributed computing system

    Elmsheuser, Johannes; The ATLAS collaboration

    2018-01-01

    The CERN ATLAS experiment successfully uses a worldwide computing infrastructure to support the physics program during LHC Run 2. The grid workflow system PanDA routinely manages 250 to 500 thousand concurrently running production and analysis jobs to process simulation and detector data. In total more than 300 PB of data is distributed over more than 150 sites in the WLCG and handled by the ATLAS data management system Rucio. To prepare for the ever growing LHC luminosity in future runs new developments are underway to even more efficiently use opportunistic resources such as HPCs and utilize new technologies. This presentation will review and explain the outline and the performance of the ATLAS distributed computing system and give an outlook to new workflow and data management ideas for the beginning of the LHC Run 3.

  16. Distributed radiation data acquisition system for KAPP

    Narsaiah, A.; Anantakrishnan, T.S.; Bairi, B.R.

    1992-01-01

    Increased concern for the safety of personnel working in Nuclear Power Stations demands an efficient centralized Radiation Data Acquisition System (RADAS) to monitor different types of radiation at distributed locations of the plant. The system provides a comprehensive picture of radio-activity level distribution in the reactor building to facilitate prompt and correct decision making to take care of any emergency situation. The system is build around an industrial IBM-PC connected to remote intelligent data acquisition units using serial data communication links. To ensure high system availability and ease of maintenance the mechanical moving disk storage has been replaced by solid state memory storage (RAM Disk). Functional CRT displays have been substituted by the assembly of IBM-PC Mother Board with built-in firmware and standard TV Monitor. The computer handles a variety of processing functions which include the conversion to engineering units, checking of alarms, display/printing of plant radiation level status and system diagnostics. Intelligent terminals have been provided with graphic and text formatting capabilities. A hot standby computer connected to analog and digital inputs takes over the system functions on the failure of the host system. Modular software written in the higher level C-language runs under a standard real-time operating system Kernel. This provides for easy modification and expandability at site. Based on the experience of its commissioning at Kakrapar Power Station a new compact version is being designed for a specific application in another class of reactor. (author). 3 refs., 1 fig

  17. Real time computer system with distributed microprocessors

    Heger, D.; Steusloff, H.; Syrbe, M.

    1979-01-01

    The usual centralized structure of computer systems, especially of process computer systems, cannot sufficiently use the progress of very large-scale integrated semiconductor technology with respect to increasing the reliability and performance and to decreasing the expenses especially of the external periphery. This and the increasing demands on process control systems has led the authors to generally examine the structure of such systems and to adapt it to the new surroundings. Computer systems with distributed, optical fibre-coupled microprocessors allow a very favourable problem-solving with decentralized controlled buslines and functional redundancy with automatic fault diagnosis and reconfiguration. A fit programming system supports these hardware properties: PEARL for multicomputer systems, dynamic loader, processor and network operating system. The necessary design principles for this are proved mainly theoretically and by value analysis. An optimal overall system of this new generation of process control systems was established, supported by results of 2 PDV projects (modular operating systems, input/output colour screen system as control panel), for the purpose of testing by apllying the system for the control of 28 pit furnaces of a steel work. (orig.) [de

  18. Distributed intelligent urban environment monitoring system

    Du, Jinsong; Wang, Wei; Gao, Jie; Cong, Rigang

    2018-02-01

    The current environmental pollution and destruction have developed into a world-wide major social problem that threatens human survival and development. Environmental monitoring is the prerequisite and basis of environmental governance, but overall, the current environmental monitoring system is facing a series of problems. Based on the electrochemical sensor, this paper designs a small, low-cost, easy to layout urban environmental quality monitoring terminal, and multi-terminal constitutes a distributed network. The system has been small-scale demonstration applications and has confirmed that the system is suitable for large-scale promotion

  19. General distributed control system for fusion experiments

    Klingner, P.L.; Levings, S.J.; Wilkins, R.W.

    1986-01-01

    A general control system using distributed LSI-11 microprocessors is being developed. Common software residues in each LSI-11 and is tailored to an application by control specifications downloaded from a host computer. The microprocessors, their control interfaces, and the micro-to-host communications are CAMAC based. The host computer also supports an operator interface, coordination of multiple microprocessors, and utilities to create and maintain the control specifications. Typical applications include monitoring safety interlocks as well as controlling vacuum systems, high voltage charging systems, and diagnostics

  20. Distributed parallel messaging for multiprocessor systems

    Chen, Dong; Heidelberger, Philip; Salapura, Valentina; Senger, Robert M; Steinmacher-Burrow, Burhard; Sugawara, Yutaka

    2013-06-04

    A method and apparatus for distributed parallel messaging in a parallel computing system. The apparatus includes, at each node of a multiprocessor network, multiple injection messaging engine units and reception messaging engine units, each implementing a DMA engine and each supporting both multiple packet injection into and multiple reception from a network, in parallel. The reception side of the messaging unit (MU) includes a switch interface enabling writing of data of a packet received from the network to the memory system. The transmission side of the messaging unit, includes switch interface for reading from the memory system when injecting packets into the network.

  1. Distributed computer controls for accelerator systems

    Moore, T.L.

    1988-09-01

    A distributed control system has been designed and installed at the Lawrence Livermore National Laboratory Multi-user Tandem Facility using an extremely modular approach in hardware and software. The two tiered, geographically organized design allowed total system implementation with four months with a computer and instrumentation cost of approximately $100K. Since the system structure is modular, application to a variety of facilities is possible. Such a system allows rethinking and operational style of the facilities, making possible highly reproducible and unattended operation. The impact of industry standards, i.e., UNIX, CAMAC, and IEEE-802.3, and the use of a graphics-oriented controls software suite allowed the efficient implementation of the system. The definition, design, implementation, operation and total system performance will be discussed. 3 refs

  2. Distributed computer controls for accelerator systems

    Moore, T. L.

    1989-04-01

    A distributed control system has been designed and installed at the Lawrence Livermore National Laboratory Multiuser Tandem Facility using an extremely modular approach in hardware and software. The two tiered, geographically organized design allowed total system implantation within four months with a computer and instrumentation cost of approximately $100k. Since the system structure is modular, application to a variety of facilities is possible. Such a system allows rethinking of operational style of the facilities, making possible highly reproducible and unattended operation. The impact of industry standards, i.e., UNIX, CAMAC, and IEEE-802.3, and the use of a graphics-oriented controls software suite allowed the effective implementation of the system. The definition, design, implementation, operation and total system performance will be discussed.

  3. Distributed computer controls for accelerator systems

    Moore, T.L.

    1989-01-01

    A distributed control system has been designed and installed at the Lawrence Livermore National Laboratory Multiuser Tandem Facility using an extremely modular approach in hardware and software. The two tiered, geographically organized design allowed total system implantation within four months with a computer and instrumentation cost of approximately $100k. Since the system structure is modular, application to a variety of facilities is possible. Such a system allows rethinking of operational style of the facilities, making possible highly reproducible and unattended operation. The impact of industry standards, i.e., UNIX, CAMAC, and IEEE-802.3, and the use of a graphics-oriented controls software suite allowed the effective implementation of the system. The definition, design, implementation, operation and total system performance will be discussed. (orig.)

  4. A distributed real-time operating system

    Tuynman, F.; Hertzberger, L.O.

    1984-07-01

    A distributed real-time operating system, Fados, has been developed for an embedded multi-processor system. The operating system is based on a host target approach and provides for communication between arbitrary processes on host and target machine. The facilities offered are, apart from process communication, access to the file system on the host by programs on the target machine and monitoring and debugging of programs on the target machine from the host. The process communication has been designed in such a way that the possibilities are the same as those offered by the Ada programming language. The operating system is implemented on a MC 68000 based multiprocessor system in combination with a Unix host. (orig.)

  5. THE STRUCTURE OF PRE-TRANSITIONAL PROTOPLANETARY DISKS. II. AZIMUTHAL ASYMMETRIES, DIFFERENT RADIAL DISTRIBUTIONS OF LARGE AND SMALL DUST GRAINS IN PDS 70 {sup ,}

    Hashimoto, J.; Wisniewski, J. [Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States); Tsukagoshi, T. [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito 310-8512 (Japan); Brown, J. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 78, Cambridge, MA 02138 (United States); Dong, R. [Astronomy Department, University of California, Berkeley, CA 94720 (United States); Muto, T. [Division of Liberal Arts, Kogakuin University, 1-24-2, Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan); Zhu, Z. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Ohashi, N.; Kudo, T.; Egner, S.; Guyon, O. [Subaru Telescope, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Kusakabe, N.; Akiyama, E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Abe, L. [Laboratoire Hippolyte Fizeau, UMR6525, Universite de Nice Sophia-Antipolis, 28, avenue Valrose, F-06108 Nice Cedex 02 (France); Brandner, W.; Carson, J.; Feldt, M. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Brandt, T. [Astrophysics Department, Institute for Advanced Study, Princeton, NJ (United States); Currie, T. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON (Canada); Grady, C. A., E-mail: jun.hashimoto@ou.edu [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); and others

    2015-01-20

    The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, and their combinations would result in different radial distributions of the gas and the small (sub-μm size) and large (millimeter size) dust grains as well as asymmetric structures in a disk. Optical/near-infrared (NIR) imaging observations and (sub-)millimeter interferometry can trace small and large dust grains, respectively; therefore multi-wavelength observations could help elucidate the origin of complicated structures of a disk. Here we report Submillimeter Array observations of the dust continuum at 1.3 mm and {sup 12}CO J = 2 → 1 line emission of the pre-transitional protoplanetary disk around the solar-mass star PDS 70. PDS 70, a weak-lined T Tauri star, exhibits a gap in the scattered light from its disk with a radius of ∼65 AU at NIR wavelengths. However, we found a larger gap in the disk with a radius of ∼80 AU at 1.3 mm. Emission from all three disk components (the gas and the small and large dust grains) in images exhibits a deficit in brightness in the central region of the disk, in particular, the dust disk in small and large dust grains has asymmetric brightness. The contrast ratio of the flux density in the dust continuum between the peak position to the opposite side of the disk reaches 1.4. We suggest the asymmetries and different gap radii of the disk around PDS 70 are potentially formed by several (unseen) accreting planets inducing dust filtration.

  6. The Structure of Pre-Transitional Protoplanetary Disks. II Azimuthal Asymmetries, Different Radial Distributions of Large and Small Dust Grains in PDS 70

    Hashimoto, J.; Tsukagoshi, T.; Brown, J. M.; Dong, R.; Muto, T.; Zhu, Z.; Wisniewski, J.; Ohashi, N.; Kudo, T.; Kusakabe, N.; hide

    2015-01-01

    The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, grain growth, anticyclonic vortex, eccentricity, and their combinations would result in different radial distributions of the gas and the small (sub-micron size) and large (millimeter size) dust grains as well as asymmetric structures in a disk. Optical/near-infrared (NIR) imaging observations and (sub-)millimeter interferometry can trace small and large dust grains, respectively; therefore multi-wavelength observations could help elucidate the origin of complicated structures of a disk. Here we report Submillimeter Array observations of the dust continuum at 1.3 mm and CO-12 J = 2 yields 1 line emission of the pre-transitional protoplanetary disk around the solar-mass star PDS 70. PDS 70, a weak-lined T Tauri star, exhibits a gap in the scattered light from its disk with a radius of approx. 65 AU at NIR wavelengths. However, we found a larger gap in the disk with a radius of approx. 80 AU at 1.3 mm. Emission from all three disk components (the gas and the small and large dust grains) in images exhibits a deficit in brightness in the central region of the disk, in particular, the dust disk in small and large dust grains has asymmetric brightness. The contrast ratio of the flux density in the dust continuum between the peak position to the opposite side of the disk reaches 1.4. We suggest the asymmetries and different gap radii of the disk around PDS 70 are potentially formed by several (unseen) accreting planets inducing dust filtration.

  7. A comparative study of the grain-size distribution of surface dust and stormwater runoff quality on typical urban roads and roofs in Beijing, China.

    Shen, Zhenyao; Liu, Jin; Aini, Guzhanuer; Gong, Yongwei

    2016-02-01

    The deposition of pollutants on impervious surfaces is a serious problem associated with rapid urbanization, which results in non-point-source pollution. Characterizing the build-up and wash-off processes of pollutants in urban catchments is essential for urban planners. In this paper, the spatial variation and particle-size distributions of five heavy metals and two nutrients in surface dust were analyzed, and the runoff water first-flush effect (FF30) and event-mean concentrations (EMCs) of 10 common constituents were characterized. The relationships between runoff variables and stormwater characteristics were examined from three typical urban impervious surfaces in Beijing, China. Dust on road surfaces with smaller grain sizes had higher pollutant concentrations, whereas concentrations of Mn, Zn, Fe, and TP in roof surface dust increased with grain size. Particles with grain sizes of 38-74 and 125-300 μm contributed most to the total pollutant load in roads, while particles with the smallest grain sizes (roads. The maximum intensity (I max) and the antecedent dry days (ADD) were critical parameters for EMCs in roads, while ADD was the only dominant parameter for EMCs on our studied roof. The rainfall intensity (RI) and maximum intensity (I max) were found to be the parameters with the strongest correlation to the first-flush effect on both roads and roofs. Significant correlations of total suspended solids (TSS) concentration in runoff with grain-size fractions of surface dust indicated that coarser particles (74-300 μm) are most likely to contribute to the solid-phase pollutants, and finer particles (<38 μm) are likely the main source of dissolved pollutants.

  8. The geometry of generalized force matching and related information metrics in coarse-graining of molecular systems

    Kalligiannaki, Evangelia; Harmandaris, Vagelis; Katsoulakis, Markos A.; Plecháč, Petr

    2015-01-01

    Using the probabilistic language of conditional expectations, we reformulate the force matching method for coarse-graining of molecular systems as a projection onto spaces of coarse observables. A practical outcome of this probabilistic description is the link of the force matching method with thermodynamic integration. This connection provides a way to systematically construct a local mean force and to optimally approximate the potential of mean force through force matching. We introduce a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (e.g., reaction coordinates, end-to-end length of chains). Furthermore, we study the equivalence of force matching with relative entropy minimization which we derive for general non-linear coarse graining maps. We present in detail the generalized force matching condition through applications to specific examples in molecular systems

  9. The geometry of generalized force matching and related information metrics in coarse-graining of molecular systems

    Kalligiannaki, Evangelia, E-mail: ekalligian@tem.uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete, 70013 Heraklion (Greece); Harmandaris, Vagelis, E-mail: harman@uoc.gr [Department of Mathematics and Applied Mathematics, University of Crete, 70013 Heraklion (Greece); Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas (FORTH), IACM/FORTH, GR-71110 Heraklion (Greece); Katsoulakis, Markos A., E-mail: markos@math.umass.edu [Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Plecháč, Petr, E-mail: plechac@math.udel.edu [Department of Mathematical Sciences, University of Delaware, Newark, Delaware 19716 (United States)

    2015-08-28

    Using the probabilistic language of conditional expectations, we reformulate the force matching method for coarse-graining of molecular systems as a projection onto spaces of coarse observables. A practical outcome of this probabilistic description is the link of the force matching method with thermodynamic integration. This connection provides a way to systematically construct a local mean force and to optimally approximate the potential of mean force through force matching. We introduce a generalized force matching condition for the local mean force in the sense that allows the approximation of the potential of mean force under both linear and non-linear coarse graining mappings (e.g., reaction coordinates, end-to-end length of chains). Furthermore, we study the equivalence of force matching with relative entropy minimization which we derive for general non-linear coarse graining maps. We present in detail the generalized force matching condition through applications to specific examples in molecular systems.

  10. Characterizing distributions of surface ozone and its impact on grain production in China, Japan and South Korea: 1990 and 2020

    Wang, Xiaoping; Mauzerall, Denise L.

    Using an integrated assessment approach, we evaluate the impact that surface O 3 in East Asia had on agricultural production in 1990 and is projected to have in 2020. We also examine the effect that emission controls and the enforcement of environmental standards could have in increasing grain production in China. We find that given projected increases in O 3 concentrations in the region, East Asian countries are presently on the cusp of substantial reductions in grain production. Our conservative estimates, based on 7- and 12-h mean (M7 or M12) exposure indices, show that due to O 3 concentrations in 1990 China, Japan and South Korea lost 1-9% of their yield of wheat, rice and corn and 23-27% of their yield of soybeans, with an associated value of 1990US 3.5, 1.2 and 0.24 billion, respectively. In 2020, assuming no change in agricultural production practices and again using M7 and M12 exposure indices, grain loss due to increased levels of O 3 pollution is projected to increase to 2-16% for wheat, rice and corn and 28-35% for soybeans; the associated economic costs are expected to increase by 82%, 33%, and 67% in 2020 over 1990 for China, Japan and South Korea, respectively. For most crops, the yield losses in 1990 based on SUM06 or W126 exposure indices are lower than yield losses estimated using M7 or M12 exposure indices in China and Japan but higher in South Korea; in 2020, the yield losses based on SUM06 or W126 exposure indices are substantially higher for all crops in all three countries. This is primarily due to the nature of the cumulative indices which weight elevated values of O 3 more heavily than lower values. Chinese compliance with its ambient O 3 standard in 1990 would have had a limited effect in reducing the grain yield loss caused by O 3 exposure, resulting in only US 0.2 billion of additional grain revenues, but in 2020 compliance could reduce the yield loss by one third and lead to an increase of US$ 2.6 (M7 or M12) -27 (SUM06) billion in

  11. Giant grains

    Leitch-Devlin, M.A.; Millar, T.J.; Williams, D.A.

    1976-01-01

    Infrared observations of the Orion nebula have been interpreted by Rowan-Robinson (1975) to imply the existence of 'giant' grains, radius approximately 10 -2 cm, throughout a volume about a parsec in diameter. Although Rowan-Robinson's model of the nebula has been criticized and the presence of such grains in Orion is disputed, the proposition is accepted, that they exist, and in this paper situations in which giant grains could arise are examined. It is found that, while a giant-grain component to the interstellar grain density may exist, it is difficult to understand how giant grains arise to the extent apparently required by the Orion nebula model. (Auth.)

  12. Investigating concentration distributions of arsenic, gold and antimony in grain-size fractions of gold ore using instrumental neutron activation analysis

    Nyarku, M.; Nyarko, B.J.B.; Serfor-Armah, Y.; Osae, S.

    2010-01-01

    Instrumental neutron activation analysis (INAA) has been used to quantify concentrations of arsenic (As), gold (Au) and antimony (Sb) in grain-size fractions of a gold ore. The ore, which was taken from the Ahafo project site of Newmont Ghana Gold Ltd., was fractionated into 14 grain-size fractions using state-of-the-art analytical sieve machine. The minimum sieve mesh size used was 36 μm and grains >2000 μm were not considered for analysis. Result of the sieving was analysed with easysieve (registered) software. The<36 μm subfraction was found to be the optimum, hosting bulk of all three elements. Arsenic was found to be highly concentrated in<36-100 μm size fractions and erratically distributed in from 150 μm fraction and above. For gold, with the exception of the subfraction <36 μm which had exceptionally high concentration, the element was found to be approximately equally distributed in all the size fractions but slightly 'played out' in 150-400 μm size fractions. Antimony occurrence in the sample was relatively high in <36 μm size fraction followed by 600, 800, 400 and 36 μm size fractions in that order. Gold content in the sample was comparatively far greater than arsenic and antimony; this is indicative of level of gold mineralization in the concession where the sample ore was taken. The concentration of gold in the composite sample was in the range 564-8420 ppm as compared to 14.33-186.92 ppm for arsenic and 1.09-9.48 ppm for antimony. Elemental concentrations were correlated with each other and with grain-size fractions and the relationships between these descriptive parameters were established.

  13. Representation of chromatic distribution for lighting system

    Rossi, Maurizio; Musante, Fulvio

    2015-01-01

    For the luminaire manufacturer, the measurement of the lighting intensity distribution (LID) emitted by lighting fixture is based on photometry. So light is measured as an achromatic value of intensity and there is no the possibility to discriminate the measurement of white vs. colored light. At the Laboratorio Luce of Politecnico di Milano a new instrument for the measurement of spectral radiant intensities distribution for lighting system has been built: the goniospectra- radiometer. This new measuring tool is based on a traditional mirror gonio-photometer with a CCD spectraradiometer controlled by a PC. Beside the traditional representation of photometric distribution we have introduced a new representation where, in addition to the information about the distribution of luminous intensity in space, new details about the chromaticity characteristic of the light sources have been implemented. Some of the results of this research have been applied in developing and testing a new line of lighting system "My White Light" (the research project "Light, Environment and Humans" funded in the Italian Lombardy region Metadistretti Design Research Program involving Politecnico di Milano, Artemide, Danese, and some other SME of the Lighting Design district), giving scientific notions and applicative in order to support the assumption that colored light sources can be used for the realization of interior luminaries that, other than just have low power consumption and long life, may positively affect the mood of people.

  14. River network bedload model: a tool to investigate the impact of flow regulation on grain size distribution in a large Alpine catchment

    Costa, Anna; Molnar, Peter

    2017-04-01

    Sediment transport rates along rivers and the grain size distribution (GSD) of coarse channel bed sediment are the result of the long term balance between transport capacity and sediment supply. Transport capacity, mainly a function of channel geometry and flow competence, can be altered by changes in climatic forcing as well as by human activities. In Alpine rivers it is hydropower production systems that are the main causes of modification to the transport capacity of water courses through flow regulation, leading over longer time scales to the adjustment of river bed GSDs. We developed a river network bedload transport model to evaluate the impacts of hydropower on the transfer of sediments and the GSDs of the Upper Rhône basin, a 5,200 km2 catchment located in the Swiss Alps. Many large reservoirs for hydropower production have been built along the main tributaries of the Rhône River since the 1960s, resulting in a complex system of intakes, tunnels, and pumping stations. Sediment storage behind dams and intakes, is accompanied by altered discharge due to hydropower operations, mainly higher flow in winter and lower in summer. It is expected that this change in flow regime may have resulted in different bedload transport. However, due the non-linear, threshold-based nature of the relation between discharge and sediment mobilization, the effects of changed hydraulic conditions are not easily deducible, and because observations of bedload in pre- and post-dam conditions are usually not available, a modelling approach is often necessary. In our modelling approach, the river network is conceptualized as a series of connected links (river reaches). Average geometric characteristics of each link (width, length, and slope of cross section) are extracted from digital elevation data, while surface roughness coefficients are assigned based on the GSD. Under the assumptions of rectangular prismatic cross sections and normal flow conditions, bed shear stress is estimated

  15. Power quality in electric distribution systems

    Mohamed, A.A.S.

    2005-01-01

    the power quality of the electric system is defined by the constant values of the voltage and frequency, the good value of the power factor close to unity, and balanced three phase voltages and currents. capacitors are widely installed in distribution systems for reactive power compensation to achieve power and energy loss reduction, voltage regulation and system capacity release. the extent of these benefits depends greatly on low the capacitors are placed on the system . the problem of how to place capacitors on the system such that these benefits are achieved and / or maximized against the cost associated with the capacitor placement is termed the general capacitor placement problem.the presented mathematical model has been developed to determine the size, number, and location of fixed capacitor banks that will maximize the saving derived from reduction in peak power and energy loss, and that will minimize the capital and installation costs of capacitors

  16. Study of rapid grain boundary migration in a nanocrystalline Ni thin film

    Kacher, Josh; Robertson, I.M.; Nowell, Matt; Knapp, J.; Hattar, Khalid

    2011-01-01

    Research highlights: → Abnormal growth is distributed randomly in the foil and initiates at different times. → Growth occurs from seemingly uncorrelated regions of the grain boundary. → Growth twins are created during all stages of abnormal grain growth. → Grain growth patterns are qualitatively similar to a vacancy diffusion model. → Grain boundaries and orientations evolve during growth to minimize system energy. - Abstract: Grain boundary migration associated with abnormal grain growth in pulsed-laser deposited Ni was studied in real time by annealing electron transparent films in situ in the transmission electron microscope. The resulting texture evolution and grain boundary types produced were evaluated by ex situ electron backscatter diffraction of interrupted anneals. The combination of these two techniques allowed for the investigation of grain growth rates, grain morphologies, and the evolution of the orientation and grain boundary distributions. Grain boundaries were found to progress in a sporadic, start/stop fashion with no evidence of a characteristic grain growth rate. The orientations of the abnormally growing grains were found to be predominately //ND throughout the annealing process. A high fraction of twin boundaries developed during the annealing process. The intermittent growth from different locations of the grain boundary is discussed in terms of a vacancy diffusion model for grain growth.

  17. High-resolution 3D X-ray microtomography as tool to investigate size distribution of grain phase and pore space in sandstones

    Kahl, Wolf-Achim; Holzheid, Astrid

    2013-04-01

    The geometry and internal structures of sandstone reservoirs, like grain size, sorting, degree of bioturbation, and the history of the diagenetic alterations determine the quantity, flow rates, and recovery of hydrocarbons present in the pore space. In this respect, processes influencing the deep reservoir quality in sandstones are either of depositional, shallow diagenetic, or deep-burial origin. To assess the effect of compaction and cementation on the pore space during diagenesis, we investigated a set of sandstone samples using high-resolution microtomography (µ-CT). By high-resolution µ-CT, size distributions (in 2D and 3D), surface areas and volume fractions of the grain skeleton and pore space of sandstones and - in addition - of mineral powders have been determined. For this study, we analysed aliquots of sandstones that exhibit either complete, partial or no cemententation of the pore space, and sets of mineral powders (quartz, feldspar, calcite). As the resolution of the µ-CT scans is in the µm-range, the surface areas determined for sandstones and powders do detect the geometric surface of the material (Kahl & Holzheid, 2010). Since there are differing approaches to "size" parameters like e.g., long/short particle axes, area equivalent radius, Feret-diameter (2D), and structural thickness (3D), we decided to illustrate the effect of various size determinations for (a) single grains, (b) grain skeletons, and (c) pore space. Therefor, the computer-aided morphometric analysis of the segmented 3D models of the reconstructed scan images comprises versatile calculation algorithms. For example, size distribution of the pore space of partially cemented sandstones can be used to infer the timing of the formation of the cement in respect to tectonic/diagenetic activities. In the case of a late-stage partial cementation of a Bunter sandstone, both pore space and cement phase show identical size distributions. On the contrary, the anhydrite cement of a

  18. Development and evaluation of a geographic information retrieval system using fine grained toponyms

    Damien Palacio

    2015-12-01

    Full Text Available Geographic information retrieval (GIR is concerned with returning information in response to an information need, typically expressed in terms of a thematic and spatial component linked by a spatial relationship. However, evaluation initiatives have often failed to show significant differences between simple text baselines and more complex spatially enabled GIR approaches. We explore the effectiveness of three systems (a text baseline, spatial query expansion, and a full GIR system utilizing both text and spatial indexes at retrieving documents from a corpus describing mountaineering expeditions, centred around fine grained toponyms. To allow evaluation, we use user generated content (UGC in the form of metadata associated with individual articles to build a test collection of queries and judgments. The test collection allowed us to demonstrate that a GIR-based method significantly outperformed a text baseline for all but very specific queries associated with very small query radii. We argue that such approaches to test collection development have much to offer in the evaluation of GIR.

  19. Identification of systems with distributed parameters

    Moret, J.M.

    1990-10-01

    The problem of finding a model for the dynamical response of a system with distributed parameters based on measured data is addressed. First a mathematical formalism is developed in order to obtain the specific properties of such a system. Then a linear iterative identification algorithm is proposed that includes these properties, and that produces better results than usual non linear minimisation techniques. This algorithm is further improved by an original data decimation that allow to artificially increase the sampling period without losing between sample information. These algorithms are tested with real laboratory data

  20. Neutron chain length distributions in subcritical systems

    Nolen, S.D.; Spriggs, G.

    1999-01-01

    In this paper, the authors present the results of the chain-length distribution as a function of k in subcritical systems. These results were obtained from a point Monte Carlo code and a three-dimensional Monte Carlo code, MC++. Based on these results, they then attempt to explain why several of the common neutron noise techniques, such as the Rossi-α and Feynman's variance-to-mean techniques, are difficult to perform in highly subcritical systems using low-efficiency detectors

  1. Power profiling of Cholesky and QR factorizations on distributed memory systems

    Bosilca, George

    2012-08-30

    This paper presents the power profile of two high performance dense linear algebra libraries on distributed memory systems, ScaLAPACK and DPLASMA. From the algorithmic perspective, their methodologies are opposite. The former is based on block algorithms and relies on multithreaded BLAS and a two-dimensional block cyclic data distribution to achieve high parallel performance. The latter is based on tile algorithms running on top of a tile data layout and uses fine-grained task parallelism combined with a dynamic distributed scheduler (DAGuE) to leverage distributed memory systems. We present performance results (Gflop/s) as well as the power profile (Watts) of two common dense factorizations needed to solve linear systems of equations, namely Cholesky and QR. The reported numbers show that DPLASMA surpasses ScaLAPACK not only in terms of performance (up to 2X speedup) but also in terms of energy efficiency (up to 62 %). © 2012 Springer-Verlag (outside the USA).

  2. Distributed Control in Multi-Vehicle Systems

    Paul A. Avery

    2013-12-01

    Full Text Available The Southwest Research Institute (SwRI Mobile Autonomous Robotics Technology Initiative (MARTI program has enabled the development of fully-autonomous passenger-sized commercial vehicles and military tactical vehicles, as well as the development of cooperative vehicle behaviors, such as cooperative sensor sharing and cooperative convoy operations. The program has also developed behaviors to interface intelligent vehicles with intelligent road-side devices. The development of intelligent vehicle behaviors cannot be approached as stand-alone phenomena; rather, they must be understood within a context of the broader traffic system dynamics. The study of other complex systems has shown that system-level behaviors emerge as a result of the spatio-temporal dynamics within a system's constituent parts. The design of such systems must therefore account for both the system-level emergent behavior, as well as behaviors of individuals within the system. It has also become clear over the past several years, for both of these domains, that human trust in the behavior of individual vehicles is paramount to broader technology adoption. This paper examines the interplay between individual vehicle capabilities, vehicle connectivity, and emergent system behaviors, and presents some considerations for a distributed control paradigm in a multi-vehicle system.

  3. Software Quality Measurement for Distributed Systems. Volume 3. Distributed Computing Systems: Impact on Software Quality.

    1983-07-01

    Distributed Computing Systems impact DrnwrR - aehR on Sotwar Quaity. PERFORMING 010. REPORT NUMBER 7. AUTNOW) S. CONTRACT OR GRANT "UMBER(*)IS ThomasY...C31 Application", "Space Systems Network", "Need for Distributed Database Management", and "Adaptive Routing". This is discussed in the last para ...data reduction, buffering, encryption, and error detection and correction functions. Examples of such data streams include imagery data, video

  4. Smart Operations in Distributed Energy Resources System

    Wei, Li; Jie, Shu; Zhang-XianYong; Qing, Zhou

    Smart grid capabilities are being proposed to help solve the challenges concerning system operations due to that the trade-offs between energy and environmental needs will be constantly negotiated while a reliable supply of electricity needs even greater assurance in case of that threats of disruption have risen. This paper mainly explores models for distributed energy resources system (DG, storage, and load),and also reviews the evolving nature of electricity markets to deal with this complexity and a change of emphasis on signals from these markets to affect power system control. Smart grid capabilities will also impact reliable operations, while cyber security issues must be solved as a culture change that influences all system design, implementation, and maintenance. Lastly, the paper explores significant questions for further research and the need for a simulation environment that supports such investigation and informs deployments to mitigate operational issues as they arise.

  5. Security of practical quantum key distribution systems

    Jain, Nitin

    2015-02-24

    This thesis deals with practical security aspects of quantum key distribution (QKD) systems. At the heart of the theoretical model of any QKD system lies a quantum-mechanical security proof that guarantees perfect secrecy of messages - based on certain assumptions. However, in practice, deviations between the theoretical model and the physical implementation could be exploited by an attacker to break the security of the system. These deviations may arise from technical limitations and operational imperfections in the physical implementation and/or unrealistic assumptions and insufficient constraints in the theoretical model. In this thesis, we experimentally investigate in depth several such deviations. We demonstrate the resultant vulnerabilities via proof-of-principle attacks on a commercial QKD system from ID Quantique. We also propose countermeasures against the investigated loopholes to secure both existing and future QKD implementations.

  6. Efficient Use of Distributed Systems for Scientific Applications

    Taylor, Valerie; Chen, Jian; Canfield, Thomas; Richard, Jacques

    2000-01-01

    distributed systems. In particular this application, illustrated in the document entails an integration of finite element and fluid dynamic simulations to address the cooling of turbine blades of a gas turbine engine design. It is not uncommon to encounter high-temperature, film-cooled turbine airfoils with 1,000,000s of degrees of freedom. This results because of the complexity of the various components of the airfoils, requiring fine-grain meshing for accuracy. Additional information is contained in the original.

  7. States of Cybersecurity: Electricity Distribution System Discussions

    Pena, Ivonne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ingram, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States); Martin, Maurice [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-16

    State and local entities that oversee the reliable, affordable provision of electricity are faced with growing and evolving threats from cybersecurity risks to our nation's electricity distribution system. All-hazards system resilience is a shared responsibility among electric utilities and their regulators or policy-setting boards of directors. Cybersecurity presents new challenges and should be a focus for states, local governments, and Native American tribes that are developing energy-assurance plans to protect critical infrastructure. This research sought to investigate the implementation of governance and policy at the distribution utility level that facilitates cybersecurity preparedness to inform the U.S. Department of Energy (DOE), Office of Energy Policy and Systems Analysis; states; local governments; and other stakeholders on the challenges, gaps, and opportunities that may exist for future analysis. The need is urgent to identify the challenges and inconsistencies in how cybersecurity practices are being applied across the United States to inform the development of best practices, mitigations, and future research and development investments in securing the electricity infrastructure. By examining the current practices and applications of cybersecurity preparedness, this report seeks to identify the challenges and persistent gaps between policy and execution and reflect the underlying motivations of distinct utility structures as they play out at the local level. This study aims to create an initial baseline of cybersecurity preparedness within the distribution electricity sector. The focus of this study is on distribution utilities not bound by the cybersecurity guidelines of the North American Electric Reliability Corporation (NERC) to examine the range of mechanisms taken by state regulators, city councils that own municipal utilities, and boards of directors of rural cooperatives.

  8. FRIB Cryogenic Distribution System and Status

    Ganni, Venkatarao [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Dixon, Kelly D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Laverdure, Nathaniel A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Yang, Shuo [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Nellis, Timothy [Michigan State Univ., East Lansing, MI (United States); Jones, S. [Michigan State Univ., East Lansing, MI (United States); Casagrande, Fabio [Michigan State Univ., East Lansing, MI (United States)

    2015-12-01

    The MSU-FRIB cryogenic distribution system supports the 2 K primary, 4 K primary, and 35 - 55 K shield operation of more than 70 loads in the accelerator and the experimental areas. It is based on JLab and SNS experience with bayonet-type disconnects between the loads and the distribution system for phased commissioning and maintenance. The linac transfer line, which features three separate transfer line segments for additional independence during phased commissioning at 4 K and 2 K, connects the folded arrangement of 49 cryomodules and 4 superconducting dipole magnets and a fourth transfer line supports the separator area cryo loads. The pressure reliefs for the transfer line process lines, located in the refrigeration room outside the tunnel/accelerator area, are piped to be vented outdoors. The transfer line designs integrate supply and return flow paths into a combined vacuum space. The main linac distribution segments are produced in a small number of standard configurations; a prototype of one such configuration has been fabricated at Jefferson Lab and has been installed at MSU to support testing of a prototype FRIB cryomodule.

  9. A distributed clinical decision support system architecture

    Shaker H. El-Sappagh

    2014-01-01

    Full Text Available This paper proposes an open and distributed clinical decision support system architecture. This technical architecture takes advantage of Electronic Health Record (EHR, data mining techniques, clinical databases, domain expert knowledge bases, available technologies and standards to provide decision-making support for healthcare professionals. The architecture will work extremely well in distributed EHR environments in which each hospital has its own local EHR, and it satisfies the compatibility, interoperability and scalability objectives of an EHR. The system will also have a set of distributed knowledge bases. Each knowledge base will be specialized in a specific domain (i.e., heart disease, and the model achieves cooperation, integration and interoperability between these knowledge bases. Moreover, the model ensures that all knowledge bases are up-to-date by connecting data mining engines to each local knowledge base. These data mining engines continuously mine EHR databases to extract the most recent knowledge, to standardize it and to add it to the knowledge bases. This framework is expected to improve the quality of healthcare, reducing medical errors and guaranteeing the safety of patients by helping clinicians to make correct, accurate, knowledgeable and timely decisions.

  10. A remote tracing facility for distributed systems

    Ehm, F.; Dworak, A.

    2012-01-01

    Today, CERN's control system is built upon a large number of C++ and Java services producing log events. In such a largely distributed environment these log messages are essential for problem recognition and tracing. Tracing is therefore vital for operation as understanding an issue in a subsystem means analysing log events in an efficient and fast manner. At present 3150 device servers are deployed on 1600 disk-less front-ends and they send their log messages via the network to an in-house developed central server which, in turn, saves them to files. However, this solution is not able to provide several highly desired features and has performance limitations which led to the development of a new solution. The new distributed tracing facility fulfills these requirements by taking advantage of the Streaming Text Oriented Messaging Protocol (STOMP) and ActiveMQ as the transport layer. The system not only allows storing critical log events centrally in files or in a database but also allows other clients (e.g. graphical interfaces) to read the same events concurrently by using the provided Java API. Thanks to the ActiveMQ broker technology the system can easily be extended to clients implemented in other languages and it is highly scalable in terms of performance. Long running tests have shown that the system can handle up to 10.000 messages/second. (authors)

  11. Implications of a North American grain marketing system for prairie transportation and elevators

    1997-09-01

    The balance of this report will examine the experiences U.S. production agriculture has had with deregulation of the transportation industry. It will highlight the evolution of the procurement segment of grain marketing, concentrating on the wheat or...

  12. Influence of fibre distribution and grain size on the mechanical behaviour of friction stir processed Mg–C composites

    Mertens, A., E-mail: anne.mertens@ulg.ac.be [Université de Liège, Faculty of Applied Science, A& M Department, Metallic Materials Science Unit (Belgium); Simar, A. [Université catholique de Louvain, Institute of Mechanics, Materials and Civil Engineering (Belgium); Adrien, J.; Maire, E. [Institut National des Sciences Appliquées de Lyon (INSA Lyon), MATEIS Laboratory (France); Montrieux, H.-M. [Université de Liège, Faculty of Applied Science, A& M Department, Metallic Materials Science Unit (Belgium); Delannay, F. [Université catholique de Louvain, Institute of Mechanics, Materials and Civil Engineering (Belgium); Lecomte-Beckers, J. [Université de Liège, Faculty of Applied Science, A& M Department, Metallic Materials Science Unit (Belgium)

    2015-09-15

    Short C fibres–Mg matrix composites have been produced by friction stir processing sandwiches made of a layer of C fabric stacked between two sheets of Mg alloy AZ31B or AZ91D. This novel processing technique can allow the easy production of large-scale metal matrix composites. The paper investigates the microstructure of FSPed C fibre–Mg composites in relation with the fragmentation of the C fibres during FSP and their influence on the tensile properties. 3D X-ray tomography reveals that the fibres orient like onion rings and are more or less fragmented depending on the local shear stress during the process. The fibre volume fraction can be increased from 2.3% to 7.1% by reducing the nugget volume, i.e. by using a higher advancing speed in AZ31B alloy or a stronger matrix alloy, like AZ91D alloy. A higher fibre volume fraction leads to a smaller grain size which brings about an increase of the composite yield strength by 15 to 25%. However, a higher fibre volume fraction also leads to a lower fracture strain. Fracture surface observations reveal that damage occurs by fibre/matrix decohesion along fibres oriented perpendicularly to the loading direction. - Graphical abstract: Display Omitted - Highlights: • C–Mg MMCs were produced by FSP sandwiches made of a C fabric between Mg sheets. • Fibre fragmentation and erosion is larger when the temperature reached during FSP is lower. • A lower advancing speed brings a lower fibre volume fraction and a lower grain size. • X-ray tomography reveals that fibres orient along the FSP material flow. • The fibres and grain size reduction increase the yield strength by 15 to 25%.

  13. Distance Protection for Microgrids in Distribution System

    Lin, Hengwei; Liu, Chengxi; Guerrero, Josep M.

    2015-01-01

    protection decreased. This paper adopts distance protection for one mid-voltage level microgrid in Aalborg, Denmark. Different operation modes of the network are analyzed and tested in the paper. The simulation results show that the variations of the fault currents seen by the forward relays are much larger...... than the backward relays. Meanwhile, the fault currents change little with the randomness of renewable energy except the intermittence. Finally, it shows that the designed distance protection has satisfactory performance to clear the various faults.......Owing to the increasing penetration of distributed generation, there are some challenges for the conventional protection in distribution system. Bidirectional power flow and variable fault current because of the various operation modes may lead to the selectivity and sensitivity of the overcurrent...

  14. DAD - Distributed Adamo Database system at Hermes

    Wander, W.; Dueren, M.; Ferstl, M.; Green, P.; Potterveld, D.; Welch, P.

    1996-01-01

    Software development for the HERMES experiment faces the challenges of many other experiments in modern High Energy Physics: Complex data structures and relationships have to be processed at high I/O rate. Experimental control and data analysis are done on a distributed environment of CPUs with various operating systems and requires access to different time dependent databases like calibration and geometry. Slow and experimental control have a need for flexible inter-process-communication. Program development is done in different programming languages where interfaces to the libraries should not restrict the capacities of the language. The needs of handling complex data structures are fulfilled by the ADAMO entity relationship model. Mixed language programming can be provided using the CFORTRAN package. DAD, the Distributed ADAMO Database library, was developed to provide the I/O and database functionality requirements. (author)

  15. Grain destruction in interstellar shocks

    Seab, C.G.; Shull, J.M.

    1984-01-01

    One of the principal methods for removing grains from the Interstellar Medium is to destroy them in shock waves. Previous theoretical studies of shock destruction have generally assumed only a single size and type of grain; most do not account for the effect of the grain destruction on the structure of the shock. Earlier calculations have been improved in three ways: first, by using a ''complete'' grain model including a distribution of sizes and types of grains; second, by using a self-consistent shock structure that incorporates the changing elemental depletions as the grains are destroyed; and third, by calculating the shock-processed ultraviolet extinction curves for comparison with observations. (author)

  16. Building a generalized distributed system model

    Mukkamala, R.

    1993-01-01

    The key elements in the 1992-93 period of the project are the following: (1) extensive use of the simulator to implement and test - concurrency control algorithms, interactive user interface, and replica control algorithms; and (2) investigations into the applicability of data and process replication in real-time systems. In the 1993-94 period of the project, we intend to accomplish the following: (1) concentrate on efforts to investigate the effects of data and process replication on hard and soft real-time systems - especially we will concentrate on the impact of semantic-based consistency control schemes on a distributed real-time system in terms of improved reliability, improved availability, better resource utilization, and reduced missed task deadlines; and (2) use the prototype to verify the theoretically predicted performance of locking protocols, etc.

  17. LHCb: Monitoring the DIRAC Distribution System

    Nandakumar, R; Santinelli, R

    2009-01-01

    DIRAC is the LHCb gateway to any computing grid infrastructure (currently supporting WLCG) and is intended to reliably run large data mining activities. The DIRAC system consists of various services (which wait to be contacted to perform actions) and agents (which carry out periodic activities) to direct jobs as required. An important part of ensuring the reliability of the infrastructure is the monitoring and logging of these DIRAC distributed systems. The monitoring is done collecting information from two sources - one is from pinging the services or by keeping track of the regular heartbeats of the agents, and the other from the analysis of the error messages generated by both agents and services and collected by the logging system. This allows us to ensure that he components are running properly and to collect useful information regarding their operations. The process status monitoring is displayed using the SLS sensor mechanism which also automatically allows one to plot various quantities and also keep ...

  18. Extremely 54Cr- and 50Ti-rich Presolar Oxide Grains in a Primitive Meteorite: Formation in Rare Types of Supernovae and Implications for the Astrophysical Context of Solar System Birth

    Nittler, Larry R.; O’D. Alexander, Conel M.; Liu, Nan; Wang, Jianhua

    2018-04-01

    We report the identification of 19 presolar oxide grains from the Orgueil CI meteorite with substantial enrichments in 54Cr, with 54Cr/52Cr ratios ranging from 1.2 to 56 times the solar value. The most enriched grains also exhibit enrichments at mass-50, most likely due in part to 50Ti, but close-to-normal or depleted 53Cr/52Cr ratios. There is a strong inverse relationship between 54Cr enrichment and grain size; the most extreme grains are all attractive, as these likely occur much more frequently than high-density SN Ia, and their evolutionary timescales (∼20 Myr) are comparable to those of molecular clouds. Self-pollution of the Sun’s parent cloud from an ECSN may explain the heterogeneous distribution of n-rich isotopic anomalies in planetary materials, including a recently reported dichotomy in Mo isotopes in the solar system. The stellar origins of three grains with solar 54Cr/52Cr, but anomalies in 50Cr or 53Cr, as well as of a grain enriched in 57Fe, are unclear.

  19. Distributed Online Learning in Social Recommender Systems

    Tekin, Cem; Zhang, Simpson; van der Schaar, Mihaela

    2014-08-01

    In this paper, we consider decentralized sequential decision making in distributed online recommender systems, where items are recommended to users based on their search query as well as their specific background including history of bought items, gender and age, all of which comprise the context information of the user. In contrast to centralized recommender systems, in which there is a single centralized seller who has access to the complete inventory of items as well as the complete record of sales and user information, in decentralized recommender systems each seller/learner only has access to the inventory of items and user information for its own products and not the products and user information of other sellers, but can get commission if it sells an item of another seller. Therefore the sellers must distributedly find out for an incoming user which items to recommend (from the set of own items or items of another seller), in order to maximize the revenue from own sales and commissions. We formulate this problem as a cooperative contextual bandit problem, analytically bound the performance of the sellers compared to the best recommendation strategy given the complete realization of user arrivals and the inventory of items, as well as the context-dependent purchase probabilities of each item, and verify our results via numerical examples on a distributed data set adapted based on Amazon data. We evaluate the dependence of the performance of a seller on the inventory of items the seller has, the number of connections it has with the other sellers, and the commissions which the seller gets by selling items of other sellers to its users.

  20. Grand Challenges in Space Technology: Distributed Satellite Systems

    Miller, David

    2001-01-01

    The MITIAFRL Distributed Satellite Systems program examines the motivation, analysis and development of technology associated with the distribution of assets and functionality over a number of cooperating satellites...

  1. The physics of distributed information systems

    Aurell, Erik

    2013-01-01

    This paper aims to introduce Distributed Systems as a field where the ideas and methods of physics can potentially be applied, and to provide entry points to a wide literature. The contributions of Leslie Lamport, inspired by Relativity Theory, and of Edsger Dijkstra, which has the flavor of a growth process, are discussed at some length. The intent of the author is primarily to stimulate interest in the statistical physics community, and the discussions are therefore framed in a non-technical language; the author apologizes in advance to readers from the computer science side for the unavoidable impreciseness and ambiguities

  2. Distributed, cooperating knowledge-based systems

    Truszkowski, Walt

    1991-01-01

    Some current research in the development and application of distributed, cooperating knowledge-based systems technology is addressed. The focus of the current research is the spacecraft ground operations environment. The underlying hypothesis is that, because of the increasing size, complexity, and cost of planned systems, conventional procedural approaches to the architecture of automated systems will give way to a more comprehensive knowledge-based approach. A hallmark of these future systems will be the integration of multiple knowledge-based agents which understand the operational goals of the system and cooperate with each other and the humans in the loop to attain the goals. The current work includes the development of a reference model for knowledge-base management, the development of a formal model of cooperating knowledge-based agents, the use of testbed for prototyping and evaluating various knowledge-based concepts, and beginning work on the establishment of an object-oriented model of an intelligent end-to-end (spacecraft to user) system. An introductory discussion of these activities is presented, the major concepts and principles being investigated are highlighted, and their potential use in other application domains is indicated.

  3. modeling workflow management in a distributed computing system

    Dr Obe

    communication system, which allows for computerized support. ... Keywords: Distributed computing system; Petri nets;Workflow management. 1. ... A distributed operating system usually .... the questionnaire is returned with invalid data,.

  4. Distributed optimization for systems design : an augmented Lagrangian coordination method

    Tosserams, S.

    2008-01-01

    This thesis presents a coordination method for the distributed design optimization of engineering systems. The design of advanced engineering systems such as aircrafts, automated distribution centers, and microelectromechanical systems (MEMS) involves multiple components that together realize the

  5. Test report light duty utility arm power distribution system (PDS)

    Clark, D.A.

    1996-01-01

    The Light Duty Utility Arm (LDUA) Power Distribution System has completed vendor and post-delivery acceptance testing. The Power Distribution System has been found to be acceptable and is now ready for integration with the overall LDUA system

  6. Photoelectric charging of dust grains

    Ignatov, A. M.

    2009-01-01

    Photoemission from the surface of a dust grain in vacuum is considered. It is shown that the cutoff in the energy spectrum of emitted electrons leads to the formation of a steady-state electron cloud. The equation describing the distribution of the electric potential in the vicinity of a dust grain is solved numerically. The dust grain charge is found as a function of the grain size.

  7. A MATHEMATICAL MODEL OF OPTIMIZATION OF THE VOLUME OF MATERIAL FLOWS IN GRAIN PROCESSING INTEGRATED PRODUCTION SYSTEMS

    Baranovskaya T. P.; Loyko V. I.; Makarevich O. A.; Bogoslavskiy S. N.

    2014-01-01

    The article suggests a mathematical model of optimization of the volume of material flows: the model for the ideal conditions; the model for the working conditions; generalized model of determining the optimal input parameters. These models optimize such parameters of inventory management in technology-integrated grain production systems, as the number of cycles supply, the volume of the source material and financial flows. The study was carried out on the example of the integrated system of ...

  8. An overview of molecular dynamics simulations of oxidized lipid systems, with a comparison of ELBA and MARTINI force fields for coarse grained lipid simulations

    Siani, Pablo; de Souza, R M; Dias, L G

    2016-01-01

    our new data of all-atom and coarse-grained simulations of hydroperoxidized lipid monolayer and bilayer systems and (iii) provide a comparison of the MARTINI and ELBA coarse grained force fields for lipid bilayer systems. We show that the better electrostatic treatment of interactions in ELBA is able...

  9. Distribution system costs associated with the deployment of photovoltaic systems

    Horowitz, Kelsey A. W.; Palmintier, Bryan; Mather, Barry; Denholm, Paul

    2018-07-01

    The broadening of our energy system to include increasing amounts of wind and solar has led to significant debate about the total costs and benefits associated with different types of generators - with potentially far-reaching policy implications. This has included debate about the cost associated with integrating these generators onto the electric grid. For photovoltaics (PV), this encompasses costs incurred on both the bulk power and distribution systems, as well as the value provided to them. These costs and benefits, in particular those associated with integrating PV onto the distribution system, are not well understood. We seek to advance the state of understanding of 'grid integration costs' for the distribution system by reviewing prior literature and outlining a transparent, bottom-up approach that can be used to calculate these costs. We provide a clear delineation of costs to integrate PV in to the distribution system within the larger context of total costs and benefits associated with PV generators. We emphasize that these costs are situationally dependent, and that a single 'cost of integration' cannot be obtained. We additionally emphasize that benefits must be considered when evaluating the competitiveness of the technology in a given situation.

  10. Distribution in flowing reaction-diffusion systems

    Kamimura, Atsushi; Herrmann, Hans J.; Ito, Nobuyasu

    2009-01-01

    A power-law distribution is found in the density profile of reacting systems A+B→C+D and 2A→2C under a flow in two and three dimensions. Different densities of reactants A and B are fixed at both ends. For the reaction A+B, the concentration of reactants asymptotically decay in space as x-1/2 and x-3/4 in two dimensions and three dimensions, respectively. For 2A, it decays as log (x) /x in two dimensions. The decay of A+B is explained considering the effect of segregation of reactants in the isotropic case. The decay for 2A is explained by the marginal behavior of two-dimensional diffusion. A logarithmic divergence of the diffusion constant with system size is found in two dimensions. © 2009 The American Physical Society.

  11. Distribution in flowing reaction-diffusion systems

    Kamimura, Atsushi

    2009-12-28

    A power-law distribution is found in the density profile of reacting systems A+B→C+D and 2A→2C under a flow in two and three dimensions. Different densities of reactants A and B are fixed at both ends. For the reaction A+B, the concentration of reactants asymptotically decay in space as x-1/2 and x-3/4 in two dimensions and three dimensions, respectively. For 2A, it decays as log (x) /x in two dimensions. The decay of A+B is explained considering the effect of segregation of reactants in the isotropic case. The decay for 2A is explained by the marginal behavior of two-dimensional diffusion. A logarithmic divergence of the diffusion constant with system size is found in two dimensions. © 2009 The American Physical Society.

  12. Distributed fiber optic moisture intrusion sensing system

    Weiss, Jonathan D.

    2003-06-24

    Method and system for monitoring and identifying moisture intrusion in soil such as is contained in landfills housing radioactive and/or hazardous waste. The invention utilizes the principle that moist or wet soil has a higher thermal conductance than dry soil. The invention employs optical time delay reflectometry in connection with a distributed temperature sensing system together with heating means in order to identify discrete areas within a volume of soil wherein temperature is lower. According to the invention an optical element and, optionally, a heating element may be included in a cable or other similar structure and arranged in a serpentine fashion within a volume of soil to achieve efficient temperature detection across a large area or three dimensional volume of soil. Remediation, moisture countermeasures, or other responsive action may then be coordinated based on the assumption that cooler regions within a soil volume may signal moisture intrusion where those regions are located.

  13. System Integration of Distributed Energy Resources

    Nyeng, Preben

    units, including the ICT solutions that can facilitate the integration. Specifically, the international standard "IEC 61850-7-420 Communications systems for Distributed Energy Resources" is considered as a possible brick in the solution. This standard has undergone continuous development....... It is therefore investigated in this project how ancillary services can be provided by alternatives to central power stations, and to what extent these can be integrated in the system by means of market-based methods. Particular emphasis is put on automatic solutions, which is particularly relevant for small......, and this project has actively contributed to its further development and improvements. Different types of integration methods are investigated in the project. Some are based on local measurement and control, e.g. by measuring the grid frequency, whereas others are based on direct remote control or market...

  14. CODA: A scalable, distributed data acquisition system

    Watson, W.A. III; Chen, J.; Heyes, G.; Jastrzembski, E.; Quarrie, D.

    1994-01-01

    A new data acquisition system has been designed for physics experiments scheduled to run at CEBAF starting in the summer of 1994. This system runs on Unix workstations connected via ethernet, FDDI, or other network hardware to multiple intelligent front end crates -- VME, CAMAC or FASTBUS. CAMAC crates may either contain intelligent processors, or may be interfaced to VME. The system is modular and scalable, from a single front end crate and one workstation linked by ethernet, to as may as 32 clusters of front end crates ultimately connected via a high speed network to a set of analysis workstations. The system includes an extensible, device independent slow controls package with drivers for CAMAC, VME, and high voltage crates, as well as a link to CEBAF accelerator controls. All distributed processes are managed by standard remote procedure calls propagating change-of-state requests, or reading and writing program variables. Custom components may be easily integrated. The system is portable to any front end processor running the VxWorks real-time kernel, and to most workstations supplying a few standard facilities such as rsh and X-windows, and Motif and socket libraries. Sample implementations exist for 2 Unix workstation families connected via ethernet or FDDI to VME (with interfaces to FASTBUS or CAMAC), and via ethernet to FASTBUS or CAMAC

  15. Systems study of fuels from grains and grasses. Phase I. Final report

    Benson, W.; Allen, A.; Athey, R.; McElroy, A.; Davis, M.; Bennett, M.

    1978-02-24

    The program reported on herein consists of a first phase analysis of the potential for significant and economically viable contributions to U.S. energy needs from grasses and grains by the photosynthetic production of biomass. The study does not include other cultivated crops such as sugar cane, sugar beets, cotton, tobacco, vegetables, fruits, etc. The scope of the study encompasses grain crop residues, whole plant biomass from grain crops and nongrain crops on cropland, and whole plant biomass from grasses on pasture, rangeland, and federal range. The basic approach to the study involves first an assessment of current total biomass generation from the various grasses and grains on cropland, pasture, range, and federal range, and aggregating the production by combinations of crop residues and whole plant biomass; second, evaluation of possibilities for introduction of new crops and expanding production to marginal or presently idle land; third, development of proposed reasonable scenarios for actually harvesting biomass from selected combinations of crop residues, forages and hays, and new crops from land now in production, plus additional marginal or underutilized land brought into production; and finally, assessment on national and regional or local scales of the production that might be affected by reasonable scenarios. This latter effort includes analysis of tentative possibilities for reallocating priorities and needs with regard to production of grain for export or for livestock production. The overall program includes a case study analysis of production economics for a representative farm of about 1,000 acres (405 ha) located in Iowa.

  16. Deformation behavior of multilayered NiFe with bimodal grain size distribution at room and elevated temperature

    Fiebig, Jochen, E-mail: jmfiebig@ucdavis.edu [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95817 (United States); Jian, Jie [Department of Electrical and Computer Engineering, Texas A& M University, College Station, TX 77843-3128 (United States); Kurmanaeva, Lilia [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95817 (United States); McCrea, Jon [Integran Technologies Inc., Toronto (Canada); Wang, Haiyan [Department of Electrical and Computer Engineering, Texas A& M University, College Station, TX 77843-3128 (United States); Lavernia, Enrique [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95817 (United States); Department of Chemical Engineering and Materials Science, University of California, Irvine, CA 92697 (United States); Mukherjee, Amiya [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95817 (United States)

    2016-02-22

    We describe a study of the temperature dependent deformation behavior of a multilayered NiFe-60 wt%Fe alloy with a layer thickness of 5 μm fabricated by electrodeposition. The structure of adjacent layers alternates between a nanocrystalline and a coarse grained. Uniaxial tensile tests at temperature between 20 °C and 400 °C and strain rate of 10{sup −4}–10{sup −2} were used to determine the mechanical behavior. Microstructure observations via transmission electron microscopy and fractography were performed to provide insight into the underlying deformation mechanism. The mechanical behavior is discussed in the context of the bimodal microstructure of multilayered samples and the contribution of each sub-layer to strength and ductility. The results reveal that even at higher temperatures the nanocrystalline layer determines the mechanical performance of multilayered materials.

  17. Distribution of volatile and non volatile elements in grain-size fractions of Apollo 17 drive tube 74001/2

    Kraehenbuehl, U.

    1980-01-01

    A study of four samples of double drive tube 74001/2 originating from 12, 25, 38, and 58 cm depths indicates that the concentrations of major and nonvolatile elements are fairly uniform for the four layers and the individual size fractions, while volatile elements as well as Au and Ir are enriched in the smaller grain-size fractions. It is concluded from the measured Au/Ir ratios and from the absence of a surface enrichment of Co that the material in the drive tube 74001/2 is not the result of an impact of an iron meteorite into a lava lake, but originated in at least three volcanic eruptions. No indication of a later disturbance of the stratigraphy of the layers is observed. Exposure ages of 345,000 and 225,000 years result from Ir deposits for the two layers of 74002

  18. Reaction and relaxation in a coarse-grained fluvial system following catchment-wide disturbance

    Tunnicliffe, Jon; Brierley, Gary; Fuller, Ian C.; Leenman, Anya; Marden, Mike; Peacock, Dave

    2018-04-01

    The Waiapu River catchment (drainage area of 1734-km2) is one of the most prolific conveyors of sediment in the world, annually delivering roughly 35 Mt of fine material to the ocean from eroding gullies, hillslopes, and reworked sediment on valley floors. Tectonic and geologic influences, in combination with a dynamic climate influenced by tropical cyclones and clearance of vegetation from steep hillslopes, predisposes this region to high rates of erosion. The bedload sediment regime of the river is strongly influenced by several exceptionally large gullies and gully complexes that produce a coarse-grained, poorly sorted sediment mixture. Rapid abrasion and breakdown leads to high rates of suspended sediment yield. A wave of bedload material, manifesting as elevated bed levels and significant widening of active alluvial fills, has been triggered by large inputs of hillslope material from a few key tributary catchments following Cyclone Bola in 1988. We review the evidence for the relaxation process of the sedimentary system in the subsequent 29 years, appraising some of the legacy effects that may endure, as associated with reworking of the considerable alluvial stores within the Waiapu system. We use Structure-from-Motion (SfM) techniques and archival aerial photos to quantify changes in sediment storage at the base of two major gully systems in recent decades. A record of over 850 cross section surveys at 62 sites on 10 rivers throughout the catchment (1958-2017) indicates recent transition from a trend of continuous accumulation to downcutting and remobilisation of valley-bottom deposits. The channel cross sections provide a minimum estimate of sediment flux from source areas to the lower reaches of the river, giving a rudimentary but spatially extensive picture of the wave of material cascading through the drainage network. The largest impacts occur in the upper steepland rivers, closest to the landslide-derived sediment supply. Transport rates here, as

  19. Effect of Tillage Systems with Corn Residue on Grain Yield of Rapeseed in Moghan Region

    J Taghinazhad

    2014-09-01

    Full Text Available This study carried out to evaluate the effect of different tillage systems on rapeseed yield (hayola 401 planted in corn residues. This experiment was done in Moghan region with clay soils during 2009-2012. Different seedbed preparation methods include MT: moldboard + disk tillage (conventional tillage was included, SCT: Stem Crusher + chisel + disk tandem harrow, STT: Stem Crusher + double-disc, CT: chisel + disk tillage and DD: two heavy disks. The experiment was conducted in a randomized complete block design with four replications. The results showed that soil bulk density in the 0-10 cm layer was not significant in different tillage treatments, but it was significantly higher than the conventional tillage in 10-20 cm depth. However, penetration resistance in 10-30 cm under DD was significantly higher than other treatments, but it was not significant in 0-10 cm layer among all tillage treatments. Thus, Comparison of the soil bulk density, penetration resistance, and plant establishment showed that the reduced tillage in canola seedbed preparation was effective. Besides, the surveys indicated that there was a significant different between MWD after primary and secondary tillage. The mean diameter weighted under SCT and DD, were 1.19 and 1.24 cm, respectively had the best status. The highest value and the worst status of this parameter observed for MT which was 1.92 cm. The highest rate of grain yield obtained by application of treatment SCT, and it was 2563.8 kg ha-1, The SCT treatment can be recommended as an effective canola bed preparation due to its significant saving in time and cost after corn harvesting.

  20. Microbial ecology and quality assurance in food fermentation systems. The case of kefir grains application.

    Plessas, S; Alexopoulos, A; Voidarou, C; Stavropoulou, E; Bezirtzoglou, E

    2011-12-01

    Fermentation technology has become a modern method for food production the last decades as a process for enhancing product stability, safety and sensory standards. The main reason for this development is the increasing consumers' demand for safe and high quality food products. The above has led the scientific community to the thorough study for the appropriate selection of specific microorganisms with desirable properties such as bacteriocin production, and probiotic properties. The main food products produced through fermentation activity are bread, wine, beer cheese and other dairy products. The microorganisms conducting the above processes are mainly yeasts and lactic acid bacteria. The end products of carbohydrate catabolism by these microorganisms contribute not only to preservation as it was believed years ago, but also to the flavour, aroma and texture and to the increase of the nutritional quality by thereby helping determine unique product characteristics. Thus, controlling the function of specific microorganisms or the succession of microorganisms that dominate the microflora is therefore advantageous, because it can increase product quality, functionality and value. Throughout the process of the discovery of microbiological diversity in various fermented food systems, the development of starter culture technology has gained more scientific attention, and it could be used for the control of the manufacturing operation, and management of product quality. In the frame of this review the presentation of the quality enhancement of most consumed fermented food products around the world is attempted and the new trends in production of fermented food products, such as bread is discussed. The review is focused in kefir grains application in bread production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. MDSplus automated build and distribution system

    Fredian, T., E-mail: twf@psfc.mit.edu [Massachusetts Institute of Technology, 175 Albany Street, Cambridge, MA 02139 (United States); Stillerman, J. [Massachusetts Institute of Technology, 175 Albany Street, Cambridge, MA 02139 (United States); Manduchi, G. [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti 4, Padova 35127 (Italy)

    2014-05-15

    Support of the MDSplus data handling system has been enhanced by the addition of an automated build system which does nightly builds of MDSplus for many computer platforms producing software packages which can now be downloaded using a web browser or via package repositories suitable for automatic updating. The build system was implemented using an extensible continuous integration server product called Hudson which schedules software builds on a collection of VMware based virtual machines. New releases are created based on updates via the MDSplus cvs code repository and versioning are managed using cvs tags and branches. Currently stable, beta and alpha releases of MDSplus are maintained for eleven different platforms including Windows, MacOSX, RedHat Enterprise Linux, Fedora, Ubuntu and Solaris. For some of these platforms, MDSplus packaging has been broken into functional modules so users can pick and choose which MDSplus features they want to install. An added feature to the latest Linux based platforms is the use of package dependencies. When installing MDSplus from the package repositories, any additional required packages used by MDSplus will be installed automatically greatly simplifying the installation of MDSplus. This paper will describe the MDSplus package automated build and distribution system.

  2. MDSplus automated build and distribution system

    Fredian, T.; Stillerman, J.; Manduchi, G.

    2014-01-01

    Support of the MDSplus data handling system has been enhanced by the addition of an automated build system which does nightly builds of MDSplus for many computer platforms producing software packages which can now be downloaded using a web browser or via package repositories suitable for automatic updating. The build system was implemented using an extensible continuous integration server product called Hudson which schedules software builds on a collection of VMware based virtual machines. New releases are created based on updates via the MDSplus cvs code repository and versioning are managed using cvs tags and branches. Currently stable, beta and alpha releases of MDSplus are maintained for eleven different platforms including Windows, MacOSX, RedHat Enterprise Linux, Fedora, Ubuntu and Solaris. For some of these platforms, MDSplus packaging has been broken into functional modules so users can pick and choose which MDSplus features they want to install. An added feature to the latest Linux based platforms is the use of package dependencies. When installing MDSplus from the package repositories, any additional required packages used by MDSplus will be installed automatically greatly simplifying the installation of MDSplus. This paper will describe the MDSplus package automated build and distribution system

  3. Distributed monitoring system based on Icinga

    Haen, C.; Bonaccorsi, E.; Neufeld, N.

    2012-01-01

    The LHCb online system relies on a large and heterogeneous IT infrastructure: it comprises more than 2000 servers and embedded systems and more than 200 network devices. Many of these equipment are critical in order to run the experiment, and it is important to have a monitoring solution efficient enough so that the experts can diagnose and act quickly. While our previous system was based on a central Nagios server, our current system uses a distributed Icinga infrastructure. We have a single instance of Icinga that schedules the checks and deals with the results but we have other servers (called 'workers') to perform the checks. The load induced on the worker is negligible, whereas the central server is fully busy. A client/server model based on Gearman manages queues the clients use to get their tasks and give their results. The other interesting feature of Icinga is the database back-end. Icinga will log the result of every action and check-result in a database. The new installation is now running 36000 service checks on 2100 hosts with 50 Gearman workers. Performances have dramatically improved

  4. The design of distributed database system for HIRFL

    Wang Hong; Huang Xinmin

    2004-01-01

    This paper is focused on a kind of distributed database system used in HIRFL distributed control system. The database of this distributed database system is established by SQL Server 2000, and its application system adopts the Client/Server model. Visual C ++ is used to develop the applications, and the application uses ODBC to access the database. (authors)

  5. Design a Fault Tolerance for Real Time Distributed System

    Ban M. Khammas

    2012-01-01

    This paper designed a fault tolerance for soft real time distributed system (FTRTDS). This system is designed to be independently on specific mechanisms and facilities of the underlying real time distributed system. It is designed to be distributed on all the computers in the distributed system and controlled by a central unit.Besides gathering information about a target program spontaneously, it provides information about the target operating system and the target hardware in order to diagno...

  6. Stability analysis of distributed order fractional chen system.

    Aminikhah, H; Refahi Sheikhani, A; Rezazadeh, H

    2013-01-01

    We first investigate sufficient and necessary conditions of stability of nonlinear distributed order fractional system and then we generalize the integer-order Chen system into the distributed order fractional domain. Based on the asymptotic stability theory of nonlinear distributed order fractional systems, the stability of distributed order fractional Chen system is discussed. In addition, we have found that chaos exists in the double fractional order Chen system. Numerical solutions are used to verify the analytical results.

  7. Stability Analysis of Distributed Order Fractional Chen System

    Aminikhah, H.; Refahi Sheikhani, A.; Rezazadeh, H.

    2013-01-01

    We first investigate sufficient and necessary conditions of stability of nonlinear distributed order fractional system and then we generalize the integer-order Chen system into the distributed order fractional domain. Based on the asymptotic stability theory of nonlinear distributed order fractional systems, the stability of distributed order fractional Chen system is discussed. In addition, we have found that chaos exists in the double fractional order Chen system. Numerical solutions are used to verify the analytical results. PMID:24489508

  8. Using high-resolution suspended-sediment measurements to infer changes in the topographic distribution and grain size of bed sediment in the Colorado River downstream from Glen Canyon Dam

    Topping, D. J.; Rubin, D. M.; Melis, T. S.; Wright, S. A.

    2004-12-01

    Eddy sandbars and other sandy deposits in and along the Colorado River in Grand Canyon National Park (GCNP) were an integral part of the pre-dam riverscape, and are still important for habitat, protection of archeological sites, and recreation. Recent work has shown that eddy bars are dynamic landforms and represent the bulk of the ecosystem's sand reserves. These deposits began eroding following the 1963 closure of Glen Canyon Dam that reduced the supply of sand at the upstream boundary of GCNP by about 94% and are still eroding today. Sand transport in the post-dam river is limited by episodic resupply from tributaries, and is equally regulated by the discharge of water and short-term changes in the grain size of sand available for transport (Rubin and Topping, WRR, 2001). During tributary floods, sand on the bed of the Colorado River fines; this causes the suspended sand to fine and the suspended-sand concentration to increase even when the discharge of water remains constant. Subsequently, the bed is winnowed of finer sand, the suspended sand coarsens, and the suspended-sand concentration decreases independently of discharge. This prohibits the computation of sand-transport rates in the Colorado River using stable relations between water discharge and sand transport (i.e., sediment rating curves) and requires a more continuous method for measuring sand transport. To monitor suspended sediment at higher (i.e., 15-minute) resolutions, we began testing a laser-acoustic system at four locations along the Colorado River in Grand Canyon in August 2002. Because they are much easier to acquire, the high-resolution suspended-sediment datasets collected using the laser-acoustic systems greatly outnumber (by >5 orders of magnitude) direct grain-size measurements of the upstream bed sediment. Furthermore, suspension processes effectively provide an average "sample" of the bed sediment on the perimeter of the upstream channel and the underwater portions of the banks and

  9. Underfrequency Load Shedding for an Islanded Distribution System With Distributed Generators

    Mahat, Pukar; Chen, Zhe; Bak-Jensen, Birgitte

    2010-01-01

    Significant penetration of distributed generation in many distribution systems has opened an option of operating distribution systems in island mode for economical and technical reasons. However, balancing frequency of the islanded system is still an issue to be solved, especially when the demand...

  10. Modelling of grain refinement driven by negative grain boundary energy

    Fischer, F. D.; Zickler, G. A.; Svoboda, Jiří

    2017-01-01

    Roč. 97, č. 23 (2017), s. 1963-1977 ISSN 1478-6435 R&D Projects: GA ČR(CZ) GA15-06390S Institutional support: RVO:68081723 Keywords : grain refinement * grain nucleation * distribution concept * jump on distribution function Subject RIV: BJ - Thermodynamics OBOR OECD: Thermodynamics Impact factor: 1.505, year: 2016

  11. Clock distribution system for digital computers

    Loomis, H.H.; Wyman, R.H.

    1981-01-01

    An apparatus is disclosed for eliminating, in each clock distribution amplifier of a clock distribution system, sequential pulse catch-up error due to one pulse ''overtaking'' a prior clock pulse. The apparatus includes timing means to produce a periodic electromagnetic signal with a fundamental frequency having a fundamental frequency component v'01(T); an array of N signal characteristic detector means, with detector means no. 1 receiving the timing means signal and producing a change-of-state signal v1(T) in response to receipt of a signal above a predetermined threshold; N substantially identical filter means, one filter means being operatively associated with each detector means, for receiving the change-of-state signal vn(T) and producing a modified change-of-state signal v'n(T) (N 1, . . . , n) having a fundamental frequency component that is substantially proportional to v'01(T- theta n(T) with a cumulative phase shift theta n(T) having a time derivative that may be made uniformly and arbitrarily small; and with the detector means n+1 (1 < or = n< n) receiving a modified change-of-state signal vn(T) from filter means no. N and, in response to receipt of such a signal above a predetermined threshold, producing a change-of-state signal vn+1

  12. Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial

    Roager, Henrik Munch; Vogt, Josef Korbinian; Kristensen, Mette

    2017-01-01

    Objective To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality. Design 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week...... dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ≥6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory...... of whole grain consumed, in particular with intake of rye. Conclusion Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation....

  13. A coarse-graining approach for molecular simulation that retains the dynamics of the all-atom reference system by implementing hydrodynamic interactions

    Markutsya, Sergiy [Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Lamm, Monica H., E-mail: mhlamm@iastate.edu [Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Department of Chemical and Biological Engineering, Iowa State University, Ames, Iowa 50011 (United States)

    2014-11-07

    We report on a new approach for deriving coarse-grained intermolecular forces that retains the frictional contribution that is often discarded by conventional coarse-graining methods. The approach is tested for water and an aqueous glucose solution, and the results from the new implementation for coarse-grained molecular dynamics simulation show remarkable agreement with the dynamics obtained from reference all-atom simulations. The agreement between the structural properties observed in the coarse-grained and all-atom simulations is also preserved. We discuss how this approach may be applied broadly to any existing coarse-graining method where the coarse-grained models are rigorously derived from all-atom reference systems.

  14. A coarse-graining approach for molecular simulation that retains the dynamics of the all-atom reference system by implementing hydrodynamic interactions

    Markutsya, Sergiy; Lamm, Monica H.

    2014-01-01

    We report on a new approach for deriving coarse-grained intermolecular forces that retains the frictional contribution that is often discarded by conventional coarse-graining methods. The approach is tested for water and an aqueous glucose solution, and the results from the new implementation for coarse-grained molecular dynamics simulation show remarkable agreement with the dynamics obtained from reference all-atom simulations. The agreement between the structural properties observed in the coarse-grained and all-atom simulations is also preserved. We discuss how this approach may be applied broadly to any existing coarse-graining method where the coarse-grained models are rigorously derived from all-atom reference systems

  15. Simulation of warehousing and distribution systems

    Drago Pupavac

    2005-08-01

    Full Text Available The modern world abounds in simulation models. Thousands of organizations use simulation models to solve business problems. Problems in micro logistics systems are a very important segment of the business problems that can be solved by a simulation method. In most cases logistics simulation models should be developed with a purpose to evaluate the performance of individual value-adding indirect resources of logistics system, their possibilities and operational advantages as well as the flow of logistics entities between the plants, warehouses, and customers. Accordingly, this scientific paper elaborates concisely the theoretical characteristics of simulation models and the domains in which the simulation approach is best suited in logistics. Special attention is paid to simulation modeling of warehousing and distribution subsystems of logistic system and there is an example of spreadsheet application in the function of simulated demand for goods from warehouse. Apart from simulation model induction and deduction methods, the description method and a method of information modeling are applied.

  16. The Unidata LDM Data Distribution System

    Emmerson, S.; Yoksas, T. C.; Weber, W. J.; Schmidt, M.

    2010-12-01

    The Unidata LDM is a near real-time, event-driven system for transmitting frequently-generated data-products, 24/7, from a producer to multiple subscribers using the Internet. Once received, a data-product is processed according to user specifications. A data-product can be anything up to 4 gigabytes in size. Downstream LDM-s register a regular expression based selection predicate with upstream LDM-s. Network topologies include point-to-point, star, and tree. Based on ONC RPC, the LDM system is extremely robust and efficient. Since its initial release in 1994, a network of LDM-s called the Internet Data Distribution (IDD) system has been the primary means by which many if not most Earth Sciences departments in the US obtain and process meteorological data (up to 20 GB/hour and 250k products/hour) with latencies measured in seconds or less. Data-products include numerical model output, radar data, WMO bulletins, and lightning data. Users of the LDM also include the international atmospheric science university community, NOAA, NASA, USGS, the US military, ECMWF, and the meteorological agencies of China, Australia, Brazil, South Korea, and Vietnam. The LDM is the highest volume advanced application on Internet-2 (currently averaging 27 terabytes per week). The LDM history and architecture is presented together with an analysis of its strengths and weaknesses.

  17. Galileo spacecraft power management and distribution system

    Detwiler, R.C.; Smith, R.L.

    1990-01-01

    It has been twelve years since two Voyager spacecraft began the direct route to the outer planets. In October 1989 a single Galileo spacecraft started the return to Jupiter. Conceived as a simple Voyager look-alike, the Galileo power management and distribution (PMAD) system has undergone many iterations in configuration. Major changes to the PMAD resulted from dual spun slip ring limitations, variations in launch vehicle thrust capabilities, and launch delays. Lack of an adequate launch vehicle for an interplanetary mission of Galileo's size has resulted in an extremely long flight duration. A Venus-Earth-Earth Gravity Assist (VEEGA) tour, vital to attain the required energy, results in a 6 year trip to Jupiter and its moons. This paper provides a description of the Galileo PMAD and documents the design drivers that established the final as-built hardware

  18. Distributed gas detection system and method

    Challener, William Albert; Palit, Sabarni; Karp, Jason Harris; Kasten, Ansas Matthias; Choudhury, Niloy

    2017-11-21

    A distributed gas detection system includes one or more hollow core fibers disposed in different locations, one or more solid core fibers optically coupled with the one or more hollow core fibers and configured to receive light of one or more wavelengths from a light source, and an interrogator device configured to receive at least some of the light propagating through the one or more solid core fibers and the one or more hollow core fibers. The interrogator device is configured to identify a location of a presence of a gas-of-interest by examining absorption of at least one of the wavelengths of the light at least one of the hollow core fibers.

  19. Systems study of fuels from grains and grasses. Quarterly progress report, July--October 1976

    Benson, W.; Allen, A.; Athey, R.; McElroy, A.

    1976-11-15

    The specific objectives of the project are to determine on a geographic basis the current and potential USA production capability for grain and grass crops, to perform a preliminary screening of conversion processes, and to perform preliminary technical and economic feasibility analyses. The results obtained to date on biomass production, conversion processes, and data management are reported. (JSR)

  20. A Bayesian framework for adaptive selection, calibration, and validation of coarse-grained models of atomistic systems

    Farrell, Kathryn, E-mail: kfarrell@ices.utexas.edu; Oden, J. Tinsley, E-mail: oden@ices.utexas.edu; Faghihi, Danial, E-mail: danial@ices.utexas.edu

    2015-08-15

    A general adaptive modeling algorithm for selection and validation of coarse-grained models of atomistic systems is presented. A Bayesian framework is developed to address uncertainties in parameters, data, and model selection. Algorithms for computing output sensitivities to parameter variances, model evidence and posterior model plausibilities for given data, and for computing what are referred to as Occam Categories in reference to a rough measure of model simplicity, make up components of the overall approach. Computational results are provided for representative applications.

  1. A Bayesian framework for adaptive selection, calibration, and validation of coarse-grained models of atomistic systems

    Farrell, Kathryn; Oden, J. Tinsley; Faghihi, Danial

    2015-08-01

    A general adaptive modeling algorithm for selection and validation of coarse-grained models of atomistic systems is presented. A Bayesian framework is developed to address uncertainties in parameters, data, and model selection. Algorithms for computing output sensitivities to parameter variances, model evidence and posterior model plausibilities for given data, and for computing what are referred to as Occam Categories in reference to a rough measure of model simplicity, make up components of the overall approach. Computational results are provided for representative applications.

  2. Sol-gel synthesis and characterization of fine-grained ceramics in the alumina-titania system

    Otterstein, E. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany)], E-mail: otterstein@physik1.uni-rostock.de; Karapetyan, G. [Institute of Chemistry, University of Rostock, Albert-Einstein-Strasse 3a, 18059 Rostock (Germany); Nicula, R. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany); Stir, M. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany); National Institute for Materials Physics, 105b Atomistilor Strasse, P.O.B. MG7, 077125 Bucharest-Magurele (Romania); Schick, C. [Institute of Physics, University of Rostock, Universitaetsplatz 3, 18051 Rostock (Germany); Burkel, E. [Institute of Physics, University of Rostock, August-Bebel-Strasse 55, 18055 Rostock (Germany)

    2008-02-05

    Fine-grained ceramics of the Al{sub 2}O{sub 3}-TiO{sub 2} system were synthesised by reactive sintering of sol-gel precursors (Al- and Ti-alkoxides). The thermal behaviour of the as-prepared xerogels was examined by thermal analysis and X-ray powder diffraction. Preliminary results concerning powder consolidation into bulk ceramic parts using spark plasma sintering (SPS) are discussed.

  3. Distributed generation and centralized power system in Thailand

    Sukkumnoed, Decharut

    2004-01-01

    The paper examines and discusses conflicts between the development of distributed power and centralized power system.......The paper examines and discusses conflicts between the development of distributed power and centralized power system....

  4. Possible mass distributions in the nebulae of other solar systems

    Brown, W.K.

    1987-01-01

    The supernova shell fragmentation model of solar system formation - previously shown to be successful in describing the mass distribution of our solar system - is used to calculate the mass distributions of other solar nebulae. (Auth.)

  5. Nitrification in Chloraminated Drinking Water Distribution Systems: Factors Affecting Occurrence

    Drinking water distribution systems with ammonia present from either naturally occurring ammonia or ammonia addition during chloramination are at risk for nitrification. Nitrification in drinking water distribution systems is undesirable and may result in water quality degradatio...

  6. Distributed adaptive droop control for DC distribution systems

    Nasirian, Vahidreza; Davoudi, Ali; Lewis, Frank

    2016-01-01

    Summary form only given: A distributed-adaptive droop mechanism is proposed for secondary/primary control of dc microgrids. The conventional secondary control that adjusts the voltage set point for the local droop mechanism is replaced by a voltage regulator. A current regulator is also added...... to fine-tune the droop coefficient for different loading conditions. The voltage regulator uses an observer that processes neighbors' data to estimate the average voltage across the microgrid. This estimation is further used to generate a voltage correction term to adjust the local voltage set point...... with the proposed controller engaged. A low-voltage dc microgrid prototype is used to verify the controller performance, link-failure resiliency, and the plug-and-play capability....

  7. Distributed Adaptive Droop Control for DC Distribution Systems

    Nasirian, Vahidreza; Davoudi, Ali; Lewis, Frank

    2014-01-01

    A distributed-adaptive droop mechanism is proposed for secondary/primary control of dc Microgrids. The conventional secondary control, that adjusts the voltage set point for the local droop mechanism, is replaced by a voltage regulator. A current regulator is then added to fine-tune the droop...... coefficient for different loading conditions. The voltage regulator uses an observer that processes neighbors’ data to estimate the average voltage across the Microgrid. This estimation is further used to generate a voltage correction term to adjust the local voltage set point. The current regulator compares...... engaged. A low-voltage dc Microgrid prototype is used to verify the controller performance, link-failure resiliency, and the plug-andplay capabilities....

  8. Day-Ahead Congestion Management in Distribution Systems through Household Demand Response and Distribution Congestion Prices

    Liu, Weijia; Wu, Qiuwei; Wen, Fushuan

    2014-01-01

    into balancing power might challenge the operation of electric distribution systems and cause congestions. This paper presents a distribution congestion price (DCP) based market mechanism to alleviate possible distribution system congestions. By employing the loca- tional marginal pricing (LMP) model...... is proposed. Finally, a practical Danish 60kV/10.5kV distribution system is employed as the test case to verify the proposed method for mitigating congestion....

  9. Fine-grained sediment spatial distribution on the basis of a geostatistical analysis: Example of the eastern Bay of the Seine (France)

    Méar, Y.; Poizot, E.; Murat, A.; Lesueur, P.; Thomas, M.

    2006-12-01

    The eastern Bay of the Seine (English Channel) was the subject in 1991 of a sampling survey of superficial sediments. Geostatistic tools were used to examine the complexity of the spatial distribution of the fine-grained fraction (discussed. Within this sedimentary unit, the distribution of the fine fraction is very heterogeneous, with mud patches of less than 4000 m diameter; the boundary between these mud patches and their substratum is very sharp. The distribution of this fine fraction appears to be controlled by an anticyclonic eddy located off the Pays de Caux. Under the influence of this, the suspended material expelled from the Seine estuary moves along the coast and swings off Antifer harbour, towards the NW. It is trapped within this eddy because of the settling of suspended particulate matter. Both at a general scale and a local scale the morphology (whether inherited or due to modern processes) has a strong influence on the spatial distribution of the fine fraction. At the general scale, the basin-like shape of the area facilitates the silting, and the presence of the submarine dunes, called "Ridins d'Antifer", clearly determines the northern limit of the muddy zone. At a local scale, the same influence is obvious: paleovalleys trap the fine sediments, whereas isolated sand dunes and ripples limit the silting. This duality of role of the morphology is therefore one of the reasons why the muddy surface is extremely heterogeneous spatially. The presence of an important population of suspension feeding echinoderm, the brittle-star Ophiothrix fragilis Abildgaard, has led to a local increase in the silting, and to the modification of the physicochemical and sedimentological parameters. A complex relationship is shown to occur between the amount of fine fraction and the number of brittle-stars (ind. m -2). Classical statistical methods are not appropriate to study the spatial distribution of the mud fraction, because the spatial component of the percentage of

  10. Cathode power distribution system and method of using the same for power distribution

    Williamson, Mark A; Wiedmeyer, Stanley G; Koehl, Eugene R; Bailey, James L; Willit, James L; Barnes, Laurel A; Blaskovitz, Robert J

    2014-11-11

    Embodiments include a cathode power distribution system and/or method of using the same for power distribution. The cathode power distribution system includes a plurality of cathode assemblies. Each cathode assembly of the plurality of cathode assemblies includes a plurality of cathode rods. The system also includes a plurality of bus bars configured to distribute current to each of the plurality of cathode assemblies. The plurality of bus bars include a first bus bar configured to distribute the current to first ends of the plurality of cathode assemblies and a second bus bar configured to distribute the current to second ends of the plurality of cathode assemblies.

  11. Advanced feed water distributing system for WWER 440 steam generators

    Matal, O.; Klinga, J. [Energovyzkum Ltd, Brno (Switzerland); Grazl, K. [Vitkovice s.c., Ostrava (Switzerland); Tischler, J.; Mihalik, M. [SEP Atomove Elektrarne Bohunice (Slovakia)

    1995-12-31

    The original designed feed water distributing system was replaced by an advanced one. The characteristics of both feed water distributing systems have been measured and evaluated. The paper deals with the problems of measurement and evaluation of both feed water distributing system characteristics and comparison of statistical data obtained. (orig.). 3 refs.

  12. Advanced feed water distributing system for WWER 440 steam generators

    Matal, O; Klinga, J [Energovyzkum Ltd, Brno (Switzerland); Grazl, K [Vitkovice s.c., Ostrava (Switzerland); Tischler, J; Mihalik, M [SEP Atomove Elektrarne Bohunice (Slovakia)

    1996-12-31

    The original designed feed water distributing system was replaced by an advanced one. The characteristics of both feed water distributing systems have been measured and evaluated. The paper deals with the problems of measurement and evaluation of both feed water distributing system characteristics and comparison of statistical data obtained. (orig.). 3 refs.

  13. Deterioration and optimal rehabilitation modelling for urban water distribution systems

    Zhou, Y.

    2018-01-01

    Pipe failures in water distribution systems can have a serious impact and hence it’s important to maintain the condition and integrity of the distribution system. This book presents a whole-life cost optimisation model for the rehabilitation of water distribution systems. It combines a pipe breakage

  14. 47 CFR 73.626 - DTV distributed transmission systems.

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false DTV distributed transmission systems. 73.626... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.626 DTV distributed transmission systems. (a... distributed transmission system (DTS). Except as expressly provided in this section, DTV stations operating a...

  15. Advanced feed water distributing system for WWER 440 steam generators

    Matal, O.; Klinga, J.; Grazl, K.; Tischler, J.; Mihalik, M.

    1995-01-01

    The original designed feed water distributing system was replaced by an advanced one. The characteristics of both feed water distributing systems have been measured and evaluated. The paper deals with the problems of measurement and evaluation of both feed water distributing system characteristics and comparison of statistical data obtained. (orig.)

  16. An Architecture for a Wide Area Distributed System

    Homburg, P.; Steen, M.R. van; Tanenbaum, A.S.

    1996-01-01

    Distributed systems provide sharing of resources and information over a computer network. A key design issue that makes these systems attractive is that all aspects related to distribution are transparent to users. Unfortunately, general-purpose wide area distributed systems that allow users to

  17. Manganese deposition in drinking water distribution systems.

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Origins of GEMS Grains

    Messenger, S.; Walker, R. M.

    2012-01-01

    Interplanetary dust particles (IDPs) collected in the Earth s stratosphere contain high abundances of submicrometer amorphous silicates known as GEMS grains. From their birth as condensates in the outflows of oxygen-rich evolved stars, processing in interstellar space, and incorporation into disks around new stars, amorphous silicates predominate in most astrophysical environments. Amorphous silicates were a major building block of our Solar System and are prominent in infrared spectra of comets. Anhydrous interplanetary dust particles (IDPs) thought to derive from comets contain abundant amorphous silicates known as GEMS (glass with embedded metal and sulfides) grains. GEMS grains have been proposed to be isotopically and chemically homogenized interstellar amorphous silicate dust. We evaluated this hypothesis through coordinated chemical and isotopic analyses of GEMS grains in a suite of IDPs to constrain their origins. GEMS grains show order of magnitude variations in Mg, Fe, Ca, and S abundances. GEMS grains do not match the average element abundances inferred for ISM dust containing on average, too little Mg, Fe, and Ca, and too much S. GEMS grains have complementary compositions to the crystalline components in IDPs suggesting that they formed from the same reservoir. We did not observe any unequivocal microstructural or chemical evidence that GEMS grains experienced prolonged exposure to radiation. We identified four GEMS grains having O isotopic compositions that point to origins in red giant branch or asymptotic giant branch stars and supernovae. Based on their O isotopic compositions, we estimate that 1-6% of GEMS grains are surviving circumstellar grains. The remaining 94-99% of GEMS grains have O isotopic compositions that are indistinguishable from terrestrial materials and carbonaceous chondrites. These isotopically solar GEMS grains either formed in the Solar System or were completely homogenized in the interstellar medium (ISM). However, the

  19. Optimizing Client Latency in a Distributed System by Using the “Remote Façade” Design Pattern

    Cosmin RABLOU

    2010-01-01

    Full Text Available In this paper we investigate the role of the Remote Façade pattern in the optimization of dis-tributed systems. The intent of this pattern is to wrap fine-grained remote objects in a coarse-grained interface and thus greatly reduce the total number of calls executed over the network. The measurement of the performance gain achieved by implementing this pattern is done through testing with a distributed application written in C# and using the latest Microsoft framework for distributed systems (Windows Communication Framework. Furthermore, we will be presenting the scenarios in which the implementation of the Remote Façade pattern brings a significant performance gain. Finally we show further scenarios in which the per-formance brought by this pattern can be investigated.

  20. Soil Carbon Changes in Transitional Grain Crop Production Systems in South Dakota

    Woodard, H. J.

    2004-12-01

    Corn-C (Zea Mays L.), soybean-S (Glycine max L.) and spring wheat-W (Triticum aestivum L.) crops were seeded as a component of either a C-S, S-W, or C-S-W crop rotation on silt-loam textured soils ranging from 3.0-5.0% organic matter. Conservation tillage(chisel plow-field cultivator) was applied to half of the plots. The other plots were direct seeded as a no-till (zero-tillage) treatment. Grain yield and surface crop residues were weighed from each treatment plot. Crop residue (stover and straw) was removed from half of the plots. After four years, soil samples were removed at various increments of depth and soil organic carbon (C) and nitrogen (N) was measured. The ranking of crop residue weights occurred by the order corn>>soybean>wheat. Surface residue accumulation was also greatest with residue treatments that were returned to the plots, those rotations in which maize was a component, and those without tillage. Mean soil organic carbon levels in the 0-7.5cm depth decreased from 3.41% to 3.19% (- 0.22%) with conventional tillage (chisel plow/field cultivator) as compared to a decrease from 3.19% to 3.05% (-0.14%) in plots without tillage over a four year period. Organic carbon in the 0-7.5cm depth decreased from 3.21% to 3.01% (- 0.20%) after residue removed as compared to a decrease from 3.39% to 3.23% (-0.17%) in plots without tillage applied after four years. The soil C:N ratio (0-7.5cm) decreased from 10.63 to 10.37 (-0.26 (unitless)) in the tilled plots over a four-year period. Soil C:N ratio at the 0-7.5cm depth decreased from 10.72 to 10.04 (-0.68) in the no-till plots over a four year period. Differences in the soil C:N ratio comparing residue removed and residue returned were similar (-0.51 vs. -0.43 respectively). These soils are highly buffered for organic carbon changes. Many cropping cycles are required to determine how soil carbon storage is significantly impacted by production systems.