WorldWideScience

Sample records for radial temperature distributions

  1. Radial Distribution Functions of Strongly Coupled Two-Temperature Plasmas

    Science.gov (United States)

    Shaffer, Nathaniel R.; Tiwari, Sanat Kumar; Baalrud, Scott D.

    2017-10-01

    We present tests of three theoretical models for the radial distribution functions (RDFs) in two-temperature strongly coupled plasmas. RDFs are useful in extending plasma thermodynamics and kinetic theory to strong coupling, but they are usually known only for thermal equilibrium or for approximate one-component model plasmas. Accurate two-component modeling is necessary to understand the impact of strong coupling on inter-species transport, e.g., ambipolar diffusion and electron-ion temperature relaxation. We demonstrate that the Seuferling-Vogel-Toeppfer (SVT) extension of the hypernetted chain equations not only gives accurate RDFs (as compared with classical molecular dynamics simulations), but also has a simple connection with the Yukawa OCP model. This connection gives a practical means to recover the structure of the electron background from knowledge of the ion-ion RDF alone. Using the model RDFs in Effective Potential Theory, we report the first predictions of inter-species transport coefficients of strongly coupled plasmas far from equilibrium. This work is supported by NSF Grant No. PHY-1453736, AFSOR Award No. FA9550-16-1-0221, and used XSEDE computational resources.

  2. Calculation of the fuel temperature coefficient of reactivity considering non-uniform radial temperature distribution in the fuel rod

    Energy Technology Data Exchange (ETDEWEB)

    Pazirandeh, Ali [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Science and Research Branch; Hooshyar Mobaraki, Almas

    2017-07-15

    The safe operation of a reactor is based on feedback models. In this paper we attempted to discuss the influence of a non-uniform radial temperature distribution on the fuel rod temperature coefficient of reactivity. The paper demonstrates that the neutron properties of a reactor core is based on effective temperature of the fuel to obtain the correct fuel temperature feedback. The value of volume-averaged temperature being used in the calculations of neutron physics with feedbacks would result in underestimating the probable event. In the calculation it is necessary to use the effective temperature of the fuel in order to provide correct accounting of the fuel temperature feedback. Fuel temperature changes in different zones of the core and consequently reactivity coefficient change are an important parameter for analysis of transient conditions. The restricting factor that compensates the inserted reactivity is the temperature reactivity coefficient and effective delayed neutron fraction.

  3. Extracting kinetic freeze-out temperature and radial flow velocity from an improved Tsallis distribution

    Energy Technology Data Exchange (ETDEWEB)

    Lao, Hai-Ling; Liu, Fu-Hu [Shanxi University, Institute of Theoretical Physics, Shanxi (China); Lacey, Roy A. [Stony Brook University, Departments of Chemistry and Physics, Stony Brook, NY (United States)

    2017-03-15

    We analyze the transverse-momentum (p{sub T}) spectra of identified particles (π{sup ±}, K{sup ±}, p, and anti p) produced in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions over a √(s{sub NN}) (center-of-mass energy per nucleon pair) range from 14.5 GeV (one of the Relativistic Heavy Ion Collider (RHIC) energies) to 2.76 TeV (one of the Large Hadron Collider (LHC) energies). For the spectra with a narrow p{sub T} range, an improved Tsallis distribution which is in fact the Tsallis distribution with radial flow is used. For the spectra with a wide p{sub T} range, a superposition of the improved Tsallis distribution and an inverse power law is used. Both the extracted kinetic freeze-out temperature (T{sub 0}) and radial flow velocity (β{sub T}) increase with the increase of √(s{sub NN}), which indicates a higher excitation and larger expansion of the interesting system at the LHC. Both the values of T{sub 0} and β{sub T} in central collisions are slightly larger than those in peripheral collisions, and they are independent of isospin and slightly dependent on mass. (orig.)

  4. Formula for radial profiles of temperature in steam-liquid sodium reactive jets

    International Nuclear Information System (INIS)

    Hobbes, P.; Mora-Perez, J.L.; Carreau, J.L.; Gbahoue, L.; Roger, F.

    1987-01-01

    One of the important problems of the study of distribution of temperatures in the reactive steam-liquid sodium jet rests in the mathematical formulation of their radial effects. During the experiment, two forms have been brought to light: from a certain distance of the injector, the radial distribution of temperature can be represented, in a classical way, by an error function curve; close to the injector, the radial profile allows for a minimum located on the axis of the jet. An energy balance permits, by dividing the jet in three parts: a central nucleus composed of practically pure gas, a gas ring plus drops and a liquid peripheral area plus bubbles, to obtain a mathematical formulation of the profiles, close to the injection which accounts quite well for the experimental points and their form

  5. A Bayesian approach to infer the radial distribution of temperature and anisotropy in the transition zone from seismic data

    Science.gov (United States)

    Drilleau, M.; Beucler, E.; Mocquet, A.; Verhoeven, O.; Moebs, G.; Burgos, G.; Montagner, J.

    2013-12-01

    Mineralogical transformations and matter transfers within the Earth's mantle make the 350-1000 km depth range (considered here as the mantle transition zone) highly heterogeneous and anisotropic. Most of the 3-D global tomographic models are anchored on small perturbations from 1-D models such as PREM, and are secondly interpreted in terms of temperature and composition distributions. However, the degree of heterogeneity in the transition zone can be strong enough so that the concept of a 1-D reference seismic model may be addressed. To avoid the use of any seismic reference model, we developed a Markov chain Monte Carlo algorithm to directly interpret surface wave dispersion curves in terms of temperature and radial anisotropy distributions, considering a given composition of the mantle. These interpretations are based on laboratory measurements of elastic moduli and Birch-Murnaghan equation of state. An originality of the algorithm is its ability to explore both smoothly varying models and first-order discontinuities, using C1-Bézier curves, which interpolate the randomly chosen values for depth, temperature and radial anisotropy. This parameterization is able to generate a self-adapting parameter space exploration while reducing the computing time. Using a Bayesian exploration, the probability distributions on temperature and anisotropy are governed by uncertainties on the data set. The method was successfully applied to both synthetic data and real dispersion curves. Surface wave measurements along the Vanuatu- California path suggest a strong anisotropy above 400 km depth which decreases below, and a monotonous temperature distribution between 350 and 1000 km depth. On the contrary, a negative shear wave anisotropy of about 2 % is found at the top of the transition zone below Eurasia. Considering compositions ranging from piclogite to pyrolite, the overall temperature profile and temperature gradient are higher for the continental path than for the oceanic

  6. Radial power density distribution of MOX fuel rods in the HBWR

    International Nuclear Information System (INIS)

    Koo, Yang Hyun; Joo, Hyung Kook; Lee, Byung Ho; Sohn, Dong Seong

    1999-07-01

    Two MOX fuel rods, which ar being fabricated in the Paul Scherrer Institute (PSI), Switzerland in cooperation with the Korea Atomic Energy Research Institute (KAERI), are going to be irradiated in the HBWR (Halden Boiling Water Reactor) from the beginning of 2000 in the framework of OECD Halden Reactor Programme (HRP) together with a reference MOX fuel rod supplied by the BNFL. Since fuel temperature, which is influenced by radial power distribution, is a basic property in analyzing fuel behavior, it is required to consider radial power distribution in the HBWR. A subroutine FACTOR H BWR that calculates radial power density distribution for three MOX fuel rods have been developed subroutine FACTOR H BWR gives good agreement with the physics calculation except slight underprediction in the central part and a little overprediction at the outer part of the pellet. The subroutine will be incorporated into a computer code COSMOS and used to analyze the in-reactor behavior of the three MOX fuel rods during the Halden irradiation test. (author). 5 refs., 3 tabs., 24 figs

  7. Temporal and radial variation of the solar wind temperature-speed relationship

    Science.gov (United States)

    Elliott, H. A.; Henney, C. J.; McComas, D. J.; Smith, C. W.; Vasquez, B. J.

    2012-09-01

    The solar wind temperature (T) and speed (V) are generally well correlated at ˜1 AU, except in Interplanetary Coronal Mass Ejections where this correlation breaks down. We perform a comprehensive analysis of both the temporal and radial variation in the temperature-speed (T-V) relationship of the non-transient wind, and our analysis provides insight into both the causes of the T-V relationship and the sources of the temperature variability. Often at 1 AU the speed-temperature relationship is well represented by a single linear fit over a speed range spanning both the slow and fast wind. However, at times the fast wind from coronal holes can have a different T-V relationship than the slow wind. A good example of this was in 2003 when there was a very large and long-lived outward magnetic polarity coronal hole at low latitudes that emitted wind with speeds as fast as a polar coronal hole. The long-lived nature of the hole made it possible to clearly distinguish that some holes can have a different T-V relationship. In an earlier ACE study, we found that both the compressions and rarefactions T-V curves are linear, but the compression curve is shifted to higher temperatures. By separating compressions and rarefactions prior to determining the radial profiles of the solar wind parameters, the importance of dynamic interactions on the radial evolution of the solar wind parameters is revealed. Although the T-V relationship at 1 AU is often well described by a single linear curve, we find that the T-V relationship continually evolves with distance. Beyond ˜2.5 AU the differences between the compressions and rarefactions are quite significant and affect the shape of the overall T-V distribution to the point that a simple linear fit no longer describes the distribution well. Since additional heating of the ambient solar wind outside of interaction regions can be associated with Alfvénic fluctuations and the turbulent energy cascade, we also estimate the heating rate

  8. Radial power density distribution of MOX fuel rods in the IFA-651

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Ho; Koo, Yang Hyun; Joo, Hyung Kook; Cheon, Jin Sik; Oh, Je Yong; Sohn, Dong Seong [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-04-01

    Two MOX fuel rods, which were fabricated in the Paul Scherrer Institute (PSI), Switzerland in cooperation with Korea Atomic Energy Research Institute, have been irradiated in the HBWR from June, 2000 in the framework of OECD-HRP together with a reference MOX fuel rod supplied by the BNFL. Since fuel temperature, which is influenced by radial power distribution, is basic in analyzing fuel behavior, it is required to consider radial power distribution in the HBWR. A subroutine FACTOR{sub H}BWR that calculates radial power density distribution for three MOX fuel rods has been developed based on neutron physics results and DEPRESS program. The developed subroutine FACTOR{sub H}BWR gives good agreement with the physics calculation except slight under-prediction at the outer part of the pellet above the burnup of 20 MWd/kgHM. The subroutine will be incorporated into a computer code COSMOS and used to analyze the in-reactor behavior of the three MOX fuel rods during the Halden irradiation test. 24 figs., 4 tabs. (Author)

  9. Investigation of radial power and temperature effects in large-scale reflood experiments

    International Nuclear Information System (INIS)

    Motley, F.

    1983-01-01

    The largest reflood test facility in the world has been designed and constructed by the Japan Atomic Energy Research Institute (JAERI). The experimental test facility, known as the Cylindrical Core Test Facility (CCTF), models a full-height core section and the four primary loops of a Pressurized Water Reactor (PWR). The radial power distribution and temperature distribution were varied during the testing program. The test results indicate that the radial effects, while noticeable, do not appreciably alter the overall quenching behavior of the facility. The Transient Reactor Analysis Code (TRAC) correctly predicted the experimental results of several of the tests. The code results indicate that the core flow pattern adjusts multidimensionally to mitigate the effects of increased power or stored energy

  10. Modelling and analysis of radial thermal stresses and temperature ...

    African Journals Online (AJOL)

    A theoretical investigation has been undertaken to study operating temperatures, heat fluxes and radial thermal stresses in the valves of a modern diesel engine with and without air-cavity. Temperatures, heat fluxes and radial thermal stresses were measured theoretically for both cases under all four thermal loading ...

  11. Comparison of Deterministic and Probabilistic Radial Distribution Systems Load Flow

    Science.gov (United States)

    Gupta, Atma Ram; Kumar, Ashwani

    2017-12-01

    Distribution system network today is facing the challenge of meeting increased load demands from the industrial, commercial and residential sectors. The pattern of load is highly dependent on consumer behavior and temporal factors such as season of the year, day of the week or time of the day. For deterministic radial distribution load flow studies load is taken as constant. But, load varies continually with a high degree of uncertainty. So, there is a need to model probable realistic load. Monte-Carlo Simulation is used to model the probable realistic load by generating random values of active and reactive power load from the mean and standard deviation of the load and for solving a Deterministic Radial Load Flow with these values. The probabilistic solution is reconstructed from deterministic data obtained for each simulation. The main contribution of the work is: Finding impact of probable realistic ZIP load modeling on balanced radial distribution load flow. Finding impact of probable realistic ZIP load modeling on unbalanced radial distribution load flow. Compare the voltage profile and losses with probable realistic ZIP load modeling for balanced and unbalanced radial distribution load flow.

  12. Dynamic radial distribution function from inelastic neutron scattering

    International Nuclear Information System (INIS)

    McQueeney, R.J.

    1998-01-01

    A real-space, local dynamic structure function g(r,ω) is defined from the dynamic structure function S(Q,ω), which can be measured using inelastic neutron scattering. At any particular frequency ω, S(Q,ω) contains Q-dependent intensity oscillations which reflect the spatial distribution and relative displacement directions for the atoms vibrating at that frequency. Information about local and dynamic atomic correlations is obtained from the Fourier transform of these oscillations g(r,ω) at the particular frequency. g(r,ω) can be formulated such that the elastic and frequency-summed limits correspond to the average and instantaneous radial distribution function, respectively, and is thus called the dynamic radial distribution function. As an example, the dynamic radial distribution function is calculated for fcc nickel in a model which considers only the harmonic atomic displacements due to phonons. The results of these calculations demonstrate that the magnitude of the atomic correlations can be quantified and g(r,ω) is a well-defined correlation function. This leads to a simple prescription for investigating local lattice dynamics. copyright 1998 The American Physical Society

  13. Stellar Angular Momentum Distributions and Preferential Radial Migration

    Science.gov (United States)

    Wyse, Rosemary; Daniel, Kathryne J.

    2018-04-01

    I will present some results from our recent investigations into the efficiency of radial migration in stellar disks of differing angular momentum distributions, within a given adopted 2D spiral disk potential. We apply to our models an analytic criterion that determines whether or not individual stars are in orbits that could lead to radial migration around the corotation resonance. We couch our results in terms of the local stellar velocity dispersion and find that the fraction of stars that could migrate radially decreases as the velocity dispersion increases. I will discuss implications and comparisons with the results of other approaches.

  14. Determination of the radial distribution function with the tomographic atom probe

    International Nuclear Information System (INIS)

    Heinrich, A.; Al-Kassab, T.

    2004-01-01

    Full text: An algorithm for the determination of the radial distribution function (RDF) and the partial radial distribution function from tomographic atom probe data is introduced and some examples for its application are discussed. Homogeneous distribution of atoms can easily be determined from measured data. Using our algorithm, the lattice of simple cubic structures may be estimated solely from TAP data. The results for bcc and fcc alloys and metals will be presented. By evaluating the vicinity of each atom, information about order phenomena in multi component alloy can be retrieved including short range order. The advantage of determining the (partial) radial distribution functions for any sample with our algorithm is that all data can be derived by one single experiment whereas all other methods of determining a pRDF require one experiment for each pRDF. (author)

  15. Optimal siting of capacitors in radial distribution network using Whale Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    D.B. Prakash

    2017-12-01

    Full Text Available In present days, continuous effort is being made in bringing down the line losses of the electrical distribution networks. Therefore proper allocation of capacitors is of utmost importance because, it will help in reducing the line losses and maintaining the bus voltage. This in turn results in improving the stability and reliability of the system. In this paper Whale Optimization Algorithm (WOA is used to find optimal sizing and placement of capacitors for a typical radial distribution system. Multi objectives such as operating cost reduction and power loss minimization with inequality constraints on voltage limits are considered and the proposed algorithm is validated by applying it on standard radial systems: IEEE-34 bus and IEEE-85 bus radial distribution test systems. The results obtained are compared with those of existing algorithms. The results show that the proposed algorithm is more effective in bringing down the operating costs and in maintaining better voltage profile. Keywords: Whale Optimization Algorithm (WOA, Optimal allocation and sizing of capacitors, Power loss reduction and voltage stability improvement, Radial distribution system, Operating cost minimization

  16. Characterization of the loss allocation techniques for radial systems with distributed generation

    International Nuclear Information System (INIS)

    Carpaneto, Enrico; Chicco, Gianfranco; Sumaili Akilimali, Jean

    2008-01-01

    In the restructured electricity industry, meaningful loss allocation methods are required in order to send correct signals to the market taking into account the location and characteristics of loads and generations, including the local sources forming the distributed generation (DG). This paper addresses the issues related to loss allocation in radial distribution systems with DG, with a three-fold focus. First, the key differences in the formulation of the loss allocation problem for radial distribution systems with respect to transmission systems are discussed, specifying the modeling and computational issues concerning the treatment of the slack node in radial distribution systems. Then, the characteristics of derivative-based and circuit-based loss allocation techniques are presented and compared, illustrating the arrangements used for adapting the various techniques to be applied to radial distribution systems with DG. Finally, the effects of introducing voltage-controllable local generation on the calculation of the loss allocation coefficients are discussed, proposing the adoption of a ''reduced'' representation of the system capable of taking into proper account the characteristics of the nodes containing voltage-controllable DG units. Numerical results are provided to show the time evolution of the loss allocation coefficients for distribution systems with variable load and local generation patterns. (author)

  17. Radial particle distributions in PARMILA simulation beams

    International Nuclear Information System (INIS)

    Boicourt, G.P.

    1984-03-01

    The estimation of beam spill in particle accelerators is becoming of greater importance as higher current designs are being funded. To the present, no numerical method for predicting beam-spill has been available. In this paper, we present an approach to the loss-estimation problem that uses probability distributions fitted to particle-simulation beams. The properties of the PARMILA code's radial particle distribution are discussed, and a broad class of probability distributions are examined to check their ability to fit it. The possibility that the PARMILA distribution is a mixture is discussed, and a fitting distribution consisting of a mixture of two generalized gamma distributions is found. An efficient algorithm to accomplish the fit is presented. Examples of the relative prediction of beam spill are given. 26 references, 18 figures, 1 table

  18. Performance Analysis of Radial Distribution Systems with UPQC and D-STATCOM

    Science.gov (United States)

    Gupta, Atma Ram; Kumar, Ashwani

    2017-08-01

    This paper presents an effective method for finding optimum location of unified power quality conditioner (UPQC) and distributed static compensator (D-STATCOM) in radial distribution system. The bus having the minimum losses is selected as the candidate bus for UPQC placement and the optimal location of D-STATCOM is found by power loss index (PLI) method. The PLI values of all the buses are calculated and the bus having the highest PLI value is the most favorable bus and thus selected as candidate bus for D-STATCOM placement. Main contribution of this paper are: (i) finding optimum location of UPQC in radial distribution system (RDS) based on minimum power loss; (ii) finding the optimal size of UPQC which offers minimum losses; (iii) calculation of annual energy saving using UPQC and D-STATCOM; (iv) cost analysis with and without UPQC and D-STATCOM placement; and (v) comparison of results with and without UPQC and D-STATCOM placement in RDS. The algorithm is tested on IEEE 33-bus and 69-bus radial distribution systems by using MATLAB software.

  19. By-pass flows and temperature distribution in a hot gas duct internally insulated by carbon stone

    International Nuclear Information System (INIS)

    Konuk, A.A.

    1979-01-01

    A mathematical model has been developed to calculate by-pass flows and temperature distribution in a hot gas duct internally insulated by carbon stone rings. The equations of conservation of mass and momentum are solved for a piping system to obtain axial and radial by-pass velocities. The energy equation is solved next by a marching method to obtain the radial temperature distribution along the duct. The results, although qualitative due to simplifications in the model, are useful to study the effects of duct geometry on its performance. (Author) [pt

  20. 3D DEM simulation and analysis of void fraction distribution in a pebble bed high temperature reactor

    International Nuclear Information System (INIS)

    Yang, Xingtuan; Gui, Nan; Tu, Jiyuan; Jiang, Shengyao

    2014-01-01

    Highlights: • We show a detailed analysis of void fraction (VF) in HTR-10 of China using DEM. • Radial distribution (RD) of VF is uniform in the core and oscillated near the wall. • Axial distribution (AD) is linearly varied along height due to effect of gravity. • Steady RD of VF in the conical base is Gaussian-like, larger than packing bed. • Joint linear and normal distribution of VF is analyzed and explained. - Abstract: The current work analyzes the radial and axial distributions of void fraction of a pebble bed high temperature reactor. A three-dimensional pebble bed corresponding to our test facility of pebble bed type gas-cooled high temperature reactor (HTR-10) in Tsinghua University is simulated via discrete element method, and the radial and axial void fraction profiles are calculated. It validates the oscillating characteristics of radial void fraction near the wall. Detailed calculations show the differences of void fraction profiles between the stationary packing bed and the dynamically discharging bed. Based on the vertically and circumferentially averaged radial distribution and horizontally averaged axial distribution of void fraction, a fully three-dimensional analytical distribution of void fraction throughout the bed is established. The results show the combined effects of gravity and void variation in the pebble bed caused by the pebble discharging. It indicates the linearly increased packing effect caused by gravity in the vertical (axial) direction and the normal distribution of void in the horizontal (radial) direction by pebble drainage. These two effects coexist in the conical base of the bed whereas only the former effect exists in the cylindrical volume of the bed

  1. Optimal Operation of Radial Distribution Systems Using Extended Dynamic Programming

    DEFF Research Database (Denmark)

    Lopez, Juan Camilo; Vergara, Pedro P.; Lyra, Christiano

    2018-01-01

    An extended dynamic programming (EDP) approach is developed to optimize the ac steady-state operation of radial electrical distribution systems (EDS). Based on the optimality principle of the recursive Hamilton-Jacobi-Bellman equations, the proposed EDP approach determines the optimal operation o...... approach is illustrated using real-scale systems and comparisons with commercial programming solvers. Finally, generalizations to consider other EDS operation problems are also discussed.......An extended dynamic programming (EDP) approach is developed to optimize the ac steady-state operation of radial electrical distribution systems (EDS). Based on the optimality principle of the recursive Hamilton-Jacobi-Bellman equations, the proposed EDP approach determines the optimal operation...... of the EDS by setting the values of the controllable variables at each time period. A suitable definition for the stages of the problem makes it possible to represent the optimal ac power flow of radial EDS as a dynamic programming problem, wherein the 'curse of dimensionality' is a minor concern, since...

  2. The three-dimensional distributions of tangential velocity and total- temperature in vortex tubes

    DEFF Research Database (Denmark)

    Linderstrøm-Lang, C.U.

    1971-01-01

    The axial and radial gradients of the tangential velocity distribution are calculated from prescribed secondary flow functions on the basis of a zero-order approximation to the momentum equations developed by Lewellen. It is shown that secondary flow functions may be devised which meet pertinent...... physical requirements and which at the same time lead to realistic tangential velocity gradients. The total-temperature distribution in both the axial and radial directions is calculated from such secondary flow functions and corresponding tangential velocity results on the basis of an approximate...

  3. Radial dose distribution of 192Ir and 137Cs seed sources

    International Nuclear Information System (INIS)

    Thomason, C.; Higgins, P.

    1989-01-01

    The radial dose distributions in water around /sup 192/ Ir seed sources with both platinum and stainless steel encapsulation have been measured using LiF thermoluminescent dosimeters (TLD) for distances of 1 to 12 cm along the perpendicular bisector of the source to determine the effect of source encapsulation. Similar measurements also have been made around a /sup 137/ Cs seed source of comparable dimensions. The data were fit to a third order polynomial to obtain an empirical equation for the radial dose factor which then can be used in dosimetry. The coefficients of this equation for each of the three sources are given. The radial dose factor of the stainless steel encapsulated /sup 192/ Ir and that of the platinum encapsulated /sup 192/ Ir agree to within 2%. The radial dose distributions measured here for /sup 192/ Ir with either type of encapsulation and for /sup 137/ Cs are indistinguishable from those of other authors when considering uncertainties involved. For clinical dosimetry based on isotropic point or line source models, any of these equations may be used without significantly affecting accuracy

  4. Temperature distribution in the Temelin NPP primary circuit piping

    International Nuclear Information System (INIS)

    Blaha, V.; Maca, K.; Kodl, P.; Kroj, L.

    2004-01-01

    Temperature non-homogeneity in the VVER 1000 reactor primary piping hot legs was detected during the commissioning of Temelin units 1 and 2. A quantification of temperature differences was carried out and explanation of its causes was presented. Mathematical analysis of the effect was carried out using the PHOENICS 3.4 code, and the results were processed graphically by means of a post processor PHOTON and by means of a user program allowing statistic evaluation of temperature profiles at the core outlet and in the area of the temperature-measurement pits. The coolant temperatures in the core area increased gradually following the given radial and axial distribution of output from the inlet temperature of 288.1 degC to 315-331 degC at the core outlet. The temperature profile was balanced and in the IO piping in the area of temperature-measurement pits the difference of the maximum and minimum temperature value was approx. 1 degC according to the calculation. The temperature field shape is mainly determined by the radial distribution of the core output. The mean outlet temperature from the core weighted through mass flow is determined by the flow through the core and by the total output. The calculated temperature span at the core outlet in the range of 315 - 331 degC corresponded well with the measured values during the operation. The values were in the range of 310-333 degC, however, the in-core thermocouple inaccuracy should also be taken into consideration. On the other hand, the temperature span in the area of temperature-measurement pits was actually about 4 times higher than the calculated temperature (observed: 4 degC as against the calculated 1 degC). A good agreement was reached between the analysis results and the actual condition of the nuclear unit in the area of the core outlet. (P.A.)

  5. Convex and Radially Concave Contoured Distributions

    Directory of Open Access Journals (Sweden)

    Wolf-Dieter Richter

    2015-01-01

    Full Text Available Integral representations of the locally defined star-generalized surface content measures on star spheres are derived for boundary spheres of balls being convex or radially concave with respect to a fan in Rn. As a result, the general geometric measure representation of star-shaped probability distributions and the general stochastic representation of the corresponding random vectors allow additional specific interpretations in the two mentioned cases. Applications to estimating and testing hypotheses on scaling parameters are presented, and two-dimensional sample clouds are simulated.

  6. The radial distribution of plutonium in high burnup UO2 fuels

    International Nuclear Information System (INIS)

    Lassmann, K.; O'Carroll, C.; Laar, J. van de; Walker, C.T.

    1994-01-01

    A new model (TUBRNP) is described which predicts the radial power density distribution as a function of burnup (and hence the radial burnup profile as a function of time) together with the radial profile of uranium and plutonium isotopes. Comparisons between measurements and the predictions of the TUBRNP model are made on fuels with enrichments in the range 2.9 to 8.25% and with burnups between 21 000 and 64 000 MWd/t. It is shown to be in excellent agreement with experimental measurements and is a marked improvement on earlier versions. (orig.)

  7. An accurate expression for radial distribution function of the Lennard-Jones fluid

    International Nuclear Information System (INIS)

    Morsali, Ali; Goharshadi, Elaheh K.; Ali Mansoori, G.; Abbaspour, Mohsen

    2005-01-01

    A simple and accurate expression for radial distribution function (RDF) of the Lennard-Jones fluid is presented. The expression explicitly states the RDF as a continuous function of reduced interparticle distance, temperature, and density. It satisfies the limiting conditions of zero density and infinite distance imposed by statistical thermodynamics. The distance dependence of this expression is expressed by an equation which contains 11 adjustable parameters. These parameters are fitted to 353 RDF data, obtained by molecular dynamics calculations, and then expressed as functions of reduced distance, temperature and density. This expression, having a total of 65 constants, reproduces the RDF data with an average root-mean-squared deviation of 0.0152 for the range of state variables of 0.5= * = * = * =ρσ 3 are reduced temperature and density, respectively). The expression predicts the pressure and the internal energy of the Lennard-Jones fluid with an uncertainty that is comparable to that obtained directly from the molecular dynamics simulations

  8. Sensitivity analysis of power depression and axial power factor effect on fuel pin to temperature and related properties distribution

    International Nuclear Information System (INIS)

    Suwardi, S.

    2001-01-01

    The presented paper is a preliminary step to evaluate the effect of radial and axial distribution of power generation on thermal analysis of whole fuel pin model with large L/D ratio. The model takes into account both radial and axial distribution of power generation due to power depression and core geometry, temperature and microstructure dependent on thermal conductivity. The microstructure distribution and the gap conductance for typical steady-state situation are given for the sensitivity analysis. The temperature and thermal conductivity distribution along the radial and axial directions obtained by different power distribution is used to indicate the sensitivity of power depression and power factor on thermal aspect. The evaluation is made for one step of incremental time and steady state approach is used. The analysis has been performed using a finite element-finite difference model. The result for typical reactor fuel shows that the sensitivity is too important to be omitted in thermal model

  9. Calculation of pellet radial power distributions with a Monte Carlo burnup code

    International Nuclear Information System (INIS)

    Suzuki, Motomu; Yamamoto, Toru; Nakata, Tetsuo

    2010-01-01

    The Japan Nuclear Energy Safety Organization (JNES) has been working on an irradiation test program of high-burnup MOX fuel at Halden Boiling Water Reactor (HBWR). MOX and UO 2 fuel rods had been irradiated up to about 64 GWd/t (rod avg.) as a Japanese utilities research program (1st phase), and using those fuel rods, in-situ measurement of fuel pellet centerline temperature was done during the 2nd phase of irradiation as the JNES test program. As part of analysis of the temperature data, power distributions in a pellet radial direction were analyzed by using a Monte Carlo burnup code MVP-BURN. In addition, the calculated results of deterministic burnup codes SRAC and PLUTON for the same problem were compared with those of MVP-BURN to evaluate their accuracy. Burnup calculations with an assembly model were performed by using MVP-BURN and those with a pin cell model by using SRAC and PLUTON. The cell pitch and, therefore, fuel to moderator ratio in the pin cell calculation was determined from the comparison of neutron energy spectra with those of MVP-BURN. The fuel pellet radial distributions of burnup and fission reaction rates at the end of the 1st phase irradiation were compared between the three codes. The MVP-BURN calculation results show a large peaking in the burnup and fission rates in the pellet outer region for the UO 2 and MOX pellets. The SRAC calculations give very close results to those of the MVP-BURN. On the other hand, the PLUTON calculations show larger burnup for the UO 2 and lower burnup for the MOX pellets in the pellet outer region than those of MVP-BURN, which lead to larger fission rates for the UO 2 and lower fission rates for the MOX pellets, respectively. (author)

  10. Reliability worth assessment of radial systems with distributed generation

    OpenAIRE

    Bellart Llavall, Francesc Xavier

    2010-01-01

    With recent advances in technology, utilities generation (DG) on the distribution systems. Reliability worth is very important in power system planning and operation. Having a DG ensures reli increase the reliability worth. This research project presents the study of a radial distribution system and the impact of placing DG in order to increase the reliability worth. where a DG have to be placed. The reliability improvement is measured by different reliability indices tha...

  11. Effects of radial distribution of entropy diffusivity on critical modes of anelastic thermal convection in rotating spherical shells

    Science.gov (United States)

    Sasaki, Youhei; Takehiro, Shin-ichi; Ishiwatari, Masaki; Yamada, Michio

    2018-03-01

    Linear stability analysis of anelastic thermal convection in a rotating spherical shell with entropy diffusivities varying in the radial direction is performed. The structures of critical convection are obtained in the cases of four different radial distributions of entropy diffusivity; (1) κ is constant, (2) κT0 is constant, (3) κρ0 is constant, and (4) κρ0T0 is constant, where κ is the entropy diffusivity, T0 is the temperature of basic state, and ρ0 is the density of basic state, respectively. The ratio of inner and outer radii, the Prandtl number, the polytropic index, and the density ratio are 0.35, 1, 2, and 5, respectively. The value of the Ekman number is 10-3 or 10-5 . In the case of (1), where the setup is same as that of the anelastic dynamo benchmark (Jones et al., 2011), the structure of critical convection is concentrated near the outer boundary of the spherical shell around the equator. However, in the cases of (2), (3) and (4), the convection columns attach the inner boundary of the spherical shell. A rapidly rotating annulus model for anelastic systems is developed by assuming that convection structure is uniform in the axial direction taking into account the strong effect of Coriolis force. The annulus model well explains the characteristics of critical convection obtained numerically, such as critical azimuthal wavenumber, frequency, Rayleigh number, and the cylindrically radial location of convection columns. The radial distribution of entropy diffusivity, or more generally, diffusion properties in the entropy equation, is important for convection structure, because it determines the distribution of radial basic entropy gradient which is crucial for location of convection columns.

  12. Modelling and analysis of radial thermal stresses and temperature ...

    African Journals Online (AJOL)

    user

    it acts as an insulating medium and prevents the heat flow, hence the need of providing insulation coating on valves is ... geometry metal components (piston, liner and cylinder head) and found a satisfactory .... model. Step8: Find the radial thermal stress at all the nodal point with the use of temperature ..... Cast iron St. 70.

  13. Temperature distribution induced by electron beam in a closed cavity

    International Nuclear Information System (INIS)

    Molhem, A.G.; Soulayman, S.Sh.

    2004-01-01

    In order to investigate heat transfer phenomena induced by EB in a closed cavity an experimental arrangement, which allows generating and focusing an electron beam in to closed cavity within 1 mm in diameter and measuring temperature all over any perpendicular section to the EB, is used for this purpose. Experimental data show that the radial distribution of current density and temperature is normal with pressure and location dependent parameters. Moreover, there is two distinguishable regions in the EB: one is central while the other surrounds the first one. (orig.)

  14. Analysis of Radial Plutonium Isotope Distribution in Irradiated Test MOX Fuel Rods

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jae Yong; Lee, Byung Ho; Koo, Yang Hyun; Kim, Han Soo

    2009-01-15

    After Rod 3 and 6 (KAERI MOX) were irradiated in the Halden reactor, their post-irradiation examinations are being carried out now. In this report, PLUTON code was implemented to analyze Rod 3 and 6 (KAERI MOX). In the both rods, the ratio of a maximum burnup to an average burnup in the radial distribution was 1.3 and the contents of {sup 239}Pu tended to increase as the radial position approached the periphery of the fuel pellet. The detailed radial distribution of {sup 239}Pu and {sup 240}Pu, however, were somewhat different. To find the reason for this difference, the contents of Pu isotopes were investigated as the burnup increased. The content of {sup 239}Pu decreased with the burnup. The content of {sup 240}Pu increased with the burnup by the 20 GWd/tM but decreased over the 20 GWd/tM. The local burnup of Rod 3 is higher than that of Rod 6 due to the hole penetrated through the fuel rod. The content of {sup 239}Pu decreased more rapidly than that of {sup 240}Pu in the Rod 6 with the increased burnup. It resulted in a radial distribution of {sup 239}Pu and {sup 240}Pu similar to Rod 3. The ratio of Xe to Kr is a parameter to find where the fissions occur in the nuclear fuel. In both Rod 3 and 6, it was 18.3 in the whole fuel rod cross section, which showed that the fissions occurred in the plutonium.

  15. Radial distributions of star populations in elliptical galaxies

    International Nuclear Information System (INIS)

    Angeletti, Lucio; Giannone, Pietro

    2010-01-01

    The dynamical structure of stars in low-ellipticity early-type galaxies has been approached in a conceptually simple manner by making use of the mass structure inferred from the radial surface brightness and the stellar metal abundance as derived from that of the contracting gas mass when the stars formed. Families of models depending on three parameters can be used to fit the surface radial profiles of spectro-photometric indices. In particular, the behavior of the spectral index Mg 2 is selected, and the observations for eleven galaxies are matched with models. With the fitting values of the free parameters, we have studied the spatial (within the galaxy) and projected (on the image of the galaxy) distributions of the metal abundances. We present the results for three chosen galaxies characterized by rather different values of the fitting parameters. Our results can be of interest for the formation of stellar populations and call attention to the need for more detailed observations.

  16. User-friendly Tool for Power Flow Analysis and Distributed Generation Optimisation in Radial Distribution Networks

    Directory of Open Access Journals (Sweden)

    M. F. Akorede

    2017-06-01

    Full Text Available The intent of power distribution companies (DISCOs is to deliver electric power to their customers in an efficient and reliable manner – with minimal energy loss cost. One major way to minimise power loss on a given power system is to install distributed generation (DG units on the distribution networks. However, to maximise benefits, it is highly crucial for a DISCO to ensure that these DG units are of optimal size and sited in the best locations on the network. This paper gives an overview of a software package developed in this study, called Power System Analysis and DG Optimisation Tool (PFADOT. The main purpose of the graphical user interface-based package is to guide a DISCO in finding the optimal size and location for DG placement in radial distribution networks. The package, which is also suitable for load flow analysis, employs the GUI feature of MATLAB. Three objective functions are formulated into a single optimisation problem and solved with fuzzy genetic algorithm to simultaneously obtain DG optimal size and location. The accuracy and reliability of the developed tool was validated using several radial test systems, and the results obtained are evaluated against the existing similar package cited in the literature, which are impressive and computationally efficient.

  17. Three-Dimensional Temperature Field Calculation and Analysis of an Axial-Radial Flux-Type Permanent Magnet Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Dong Li

    2018-05-01

    Full Text Available This article concentrates on the steady-state thermal characteristics of the Axial-Radial Flux-Type Permanent Magnet Synchronous Motor (ARFTPMSM. Firstly, the three-dimensional mathematical models for electromagnetic calculation and analyses are established, and the machine loss, including the stator loss, armature winding loss, rotor loss, and axial structure loss is calculated by using time-step Finite Element Method (FEM. Then, the loss distribution is assigned as the heat source for the thermal calculation. Secondly, the mathematical model for thermal calculation is also established. The assumptions and the boundary conditions are proposed to simplify the calculation and to improve convergence. Thirdly, the three-dimensional electromagnetic and thermal calculations of the machine, of which the armature winding and axial field winding are developed by using copper wires, are solved, from which the temperature distributions of the machine components are obtained. The experiments are carried out on the prototype with copper wires to validate the accuracy of the established models. Then, the temperature distributions of machine components under different Axial Magnetic Motive Force (AMMF are investigated. Since the machine is finally developing by using HTS wires, the temperature distributions of machine developed by utilizing High Temperature Superconducting (HTS wires, are also studied. The temperature distribution differences of the machine developed by using copper wires and HTS wires are drawn. All of these above will provide a helpful reference for the thermal calculation of the ARFTPMSM, as well as the design of the HTS coils and the cryogenic cooling system.

  18. Gas puff radiation performance as a function of radial mass distribution

    International Nuclear Information System (INIS)

    Coleman, Philip L.; Krishnan, Mahadevan; Prasad, Rahul; Qi, Niansheng; Waisman, Eduardo; Failor, B.H.; Levine, J.S.; Sze, H.

    2002-01-01

    The basic concept of a z-pinch, that JxB forces implode a shell of mass, creating a hot dense plasma on-axis, is coming under closer scrutiny. Wire arrays may start with an initial cold mass in a near 'ideal' shell, but in fact they appear to develop complex radial mass distributions well before the final x-ray output. We consider here the situation for gas puff z-pinches. While the ideal of a gas 'shell' has been the nominal objective for many years, detailed measurements of gas flow show that nozzles used for plasma radiation sources (PRS) also have complex radial distributions. In particular, there are significant data showing that the best x-ray yield comes from the least shell-like distributions. Recent experiments on the Double Eagle generator with argon have further enhanced this view. For those tests with a double 'shell' nozzle, there was a factor of almost 4 increase in yield when the relative mass (outer:inner) in the two shells was changed from 2:1 to less than 1:1. We suggest the following explanation. A configuration with most of its mass at large radii is subject to severe disruption by instabilities during the implosion. A more continuous radial mass distribution with dρ/dr < 0 may mitigate instability development (via the 'snowplow stabilization' mechanism) and thus enhance the thermalization of the kinetic energy of the imploding mass. In addition, the appropriate balance of outer to inner mass maximizes the formation of a strong shock in the core of the pinch that heats the plasma and leads to x-ray emission

  19. Distributed temperature sensors development using an stepped-helical ultrasonic waveguide

    Science.gov (United States)

    Periyannan, Suresh; Rajagopal, Prabhu; Balasubramaniam, Krishnan

    2018-04-01

    This paper presents the design and development of the distributed ultrasonic waveguide temperature sensors using some stepped-helical structures. Distributed sensing has several applications in various industries (oil, glass, steel) for measurement of physical parameters such as level, temperature, viscosity, etc. This waveguide incorporates a special notch or bend for obtaining ultrasonic wave reflections from the desired locations (Gage-lengths) where local measurements are desired. In this paper, a multi-location measurement wave-guide, with a measurement capability of 18 locations in a single wire, has been fabricated. The distribution of these sensors is both in the axial as well as radial directions using a stepped-helical spring configuration. Also, different high temperature materials have been chosen for the wave-guide. Both lower order axi-symmetric guided ultrasonic modes (L(0,1) and T(0,1)) were employed. These wave modes were generated/received (pulse-echo approach) using conventional longitudinal and shear transducers, respectively. Also, both the wave modes were simultaneously generated/received and compared using shear transducer for developing the distributed helical wave-guide sensors. The effect of dispersion of the wave modes due to curvature effects will also be discussed.

  20. Weighted radial dimension: an improved fractal measurement for highway transportation networks distribution

    Science.gov (United States)

    Feng, Yongjiu; Liu, Miaolong; Tong, Xiaohua

    2007-06-01

    An improved fractal measurement, the weighted radial dimension, is put forward for highway transportation networks distribution. The radial dimension (DL), originated from subway investigation in Stuttgart, is a fractal measurement for transportation systems under ideal assumption considering all the network lines to be homogeneous curves, ignoring the difference on spatial structure, quality and level, especially the highway networks. Considering these defects of radial dimension, an improved fractal measurement called weighted radial dimension (D WL) is introduced and the transportation system in Guangdong province is studied in detail using this novel method. Weighted radial dimensions are measured and calculated, and the spatial structure, intensity and connectivity of transportation networks are discussed in Guangdong province and the four sub-areas: the Pearl River Delta area, the East Costal area, the West Costal area and the Northern Guangdong area. In Guangdong province, the fractal spatial pattern characteristics of transportation system vary remarkably: it is the highest in the Pearl River Delta area, moderate in Costal area and lowest in the Northern Guangdong area. With the Pearl River Delta area as the centre, the weighted radial dimensions decrease with the distance increasing, while the decline level is smaller in the costal area and greater in the Northern Guangdong province. By analysis of the conic of highway density, it is recognized that the density decrease with the distance increasing from the calculation centre (Guangzhou), demonstrating the same trend as weighted radial dimensions shown. Evidently, the improved fractal measurement, weighted radial dimension, is an indictor describing the characteristics of highway transportation system more effectively and accurately.

  1. Influence of temperature and hydrogen content on stress-induced radial hydride precipitation in Zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    Desquines, J., E-mail: jean.desquines@irsn.fr; Drouan, D.; Billone, M.; Puls, M.P.; March, P.; Fourgeaud, S.; Getrey, C.; Elbaz, V.; Philippe, M.

    2014-10-15

    Radial hydride precipitation in stress relieved Zircaloy-4 fuel claddings is studied using a new thermal–mechanical test. Two maximum temperatures for radial hydride precipitation heat treatment are studied, 350 and 450 °C with hydrogen contents ranging between 50 and 600 wppm. The new test provides two main results of interest: the minimum hoop stress required to precipitate radial hydrides and a maximum stress above which, all hydrides precipitate in the radial direction. Based on these two extreme stress conditions, a model is derived to determine the stress level required to obtain a given fraction of radial hydrides after high temperature thermal–mechanical heat treatment. The proposed model is validated using metallographic observation data on pressurized tubes cooled down under constant pressure. Most of the samples with reoriented hydrides are further subjected to a ductility test. Using finite element modeling, the test results are analyzed in terms of crack nucleation within radial hydrides at the outer diameter and crack growth through the thickness of the tubular samples. The combination of test results shows that samples with hydrogen contents of about 100 wppm had the lowest ductility.

  2. Comparison of Conductor-Temperature Calculations Based on Different Radial-Position-Temperature Detections for High-Voltage Power Cable

    Directory of Open Access Journals (Sweden)

    Lin Yang

    2018-01-01

    Full Text Available In this paper, the calculation of the conductor temperature is related to the temperature sensor position in high-voltage power cables and four thermal circuits—based on the temperatures of insulation shield, the center of waterproof compound, the aluminum sheath, and the jacket surface are established to calculate the conductor temperature. To examine the effectiveness of conductor temperature calculations, simulation models based on flow characteristics of the air gap between the waterproof compound and the aluminum are built up, and thermocouples are placed at the four radial positions in a 110 kV cross-linked polyethylene (XLPE insulated power cable to measure the temperatures of four positions. In measurements, six cases of current heating test under three laying environments, such as duct, water, and backfilled soil were carried out. Both errors of the conductor temperature calculation and the simulation based on the temperature of insulation shield were significantly smaller than others under all laying environments. It is the uncertainty of the thermal resistivity, together with the difference of the initial temperature of each radial position by the solar radiation, which led to the above results. The thermal capacitance of the air has little impact on errors. The thermal resistance of the air gap is the largest error source. Compromising the temperature-estimation accuracy and the insulation-damage risk, the waterproof compound is the recommended sensor position to improve the accuracy of conductor-temperature calculation. When the thermal resistances were calculated correctly, the aluminum sheath is also the recommended sensor position besides the waterproof compound.

  3. Hurst's Exponent Determination for Radial Distribution Functions of In, Sn and In-40 wt%Sn Melt

    International Nuclear Information System (INIS)

    Zhou Yong-Zhi; Li Mei; Geng Hao-Ran; Yang Zhong-Xi; Sun Chun-Jing

    2011-01-01

    Hurst's exponent of radial distribution functions (RDFs) within the short-range scope of In, Sn and In-40 wt % Sn melts are determined by the rescaled range analysis method. Hurst's exponents H are between 0.94 and 0.97, which display long-range dependence. Within short-range scope, the number of particles from a reference particle belongs to fractional Brownian motion. After RDF serials are randomly scrambled, Hurst's exponents all dramatically dropped, which proves long-range dependence. H irregularly varies as the temperature rises, but the change tendency is not consistent with the correlation radius r c . (general)

  4. Filtering peripheral high temperature electrons in a cylindrical rf-driven plasmas by an axisymmetric radial magnetic field

    Science.gov (United States)

    Akahoshi, Hikaru; Takahashi, Kazunori; Ando, Akira

    2018-03-01

    High temperature electrons generated near a radial wall of a cylindrical source tube in a radiofrequency (rf) inductively-coupled plasma is filtered by an axisymmetric radial magnetic field formed near the source exit by locating annular permanent magnets, where the axial magnetic field strength in the radially central region is fairly uniform inside the source tube and is close to zero near the source exit. The source is operated at 3 mTorr in argon and the rf antenna is powered by a 13.56 MHz and 400 W rf generator. Measurement of electron energy probability functions shows the presence of the peripheral high temperature electrons inside the source, while the temperature of the peripheral electrons downstream of the source is observed to be reduced.

  5. A simple scaling law for the equation of state and the radial distribution functions calculated by density-functional theory molecular dynamics

    Science.gov (United States)

    Danel, J.-F.; Kazandjian, L.

    2018-06-01

    It is shown that the equation of state (EOS) and the radial distribution functions obtained by density-functional theory molecular dynamics (DFT-MD) obey a simple scaling law. At given temperature, the thermodynamic properties and the radial distribution functions given by a DFT-MD simulation remain unchanged if the mole fractions of nuclei of given charge and the average volume per atom remain unchanged. A practical interest of this scaling law is to obtain an EOS table for a fluid from that already obtained for another fluid if it has the right characteristics. Another practical interest of this result is that an asymmetric mixture made up of light and heavy atoms requiring very different time steps can be replaced by a mixture of atoms of equal mass, which facilitates the exploration of the configuration space in a DFT-MD simulation. The scaling law is illustrated by numerical results.

  6. Structure of the radial electric field and toroidal/poloidal flow in high temperature toroidal plasma

    International Nuclear Information System (INIS)

    Ida, Katsumi

    2001-01-01

    The structure of the radial electric field and toroidal/poloidal flow is discussed for the high temperature plasma in toroidal systems, tokamak and Heliotron type magnetic configurations. The spontaneous toroidal and poloidal flows are observed in the plasma with improved confinement. The radial electric field is mainly determined by the poloidal flow, because the contribution of toroidal flow to the radial electric field is small. The jump of radial electric field and poloidal flow are commonly observed near the plasma edge in the so-called high confinement mode (H-mode) plasmas in tokamaks and electron root plasma in stellarators including Heliotrons. In general the toroidal flow is driven by the momentum input from neutral beam injected toroidally. There is toroidal flow not driven by neutral beam in the plasma and it will be more significant in the plasma with large electric field. The direction of these spontaneous toroidal flows depends on the symmetry of magnetic field. The spontaneous toroidal flow driven by the ion temperature gradient is in the direction to increase the negative radial electric field in tokamak. The direction of spontaneous toroidal flow in Heliotron plasmas is opposite to that in tokamak plasma because of the helicity of symmetry of the magnetic field configuration. (author)

  7. Filtering peripheral high temperature electrons in a cylindrical rf-driven plasmas by an axisymmetric radial magnetic field

    Directory of Open Access Journals (Sweden)

    Hikaru Akahoshi

    2018-03-01

    Full Text Available High temperature electrons generated near a radial wall of a cylindrical source tube in a radiofrequency (rf inductively-coupled plasma is filtered by an axisymmetric radial magnetic field formed near the source exit by locating annular permanent magnets, where the axial magnetic field strength in the radially central region is fairly uniform inside the source tube and is close to zero near the source exit. The source is operated at 3 mTorr in argon and the rf antenna is powered by a 13.56 MHz and 400 W rf generator. Measurement of electron energy probability functions shows the presence of the peripheral high temperature electrons inside the source, while the temperature of the peripheral electrons downstream of the source is observed to be reduced.

  8. Improvement of the CULTEX® exposure technology by radial distribution of the test aerosol.

    Science.gov (United States)

    Aufderheide, Michaela; Heller, Wolf-Dieter; Krischenowski, Olaf; Möhle, Niklas; Hochrainer, Dieter

    2017-07-05

    The exposure of cellular based systems cultivated on microporous membranes at the air-liquid interface (ALI) has been accepted as an appropriate approach to simulate the exposure of cells of the respiratory tract to native airborne substances. The efficiency of such an exposure procedure with regard to stability and reproducibility depends on the optimal design at the interface between the cellular test system and the exposure technique. The actual exposure systems favor the dynamic guidance of the airborne substances to the surface of the cells in specially designed exposure devices. Two module types, based on a linear or radial feed of the test atmosphere to the test system, were used for these studies. In our technical history, the development started with the linear designed version, the CULTEX ® glass modules, fulfilling basic requirements for running ALI exposure studies (Mohr and Durst, 2005). The instability in the distribution of different atmospheres to the cells caused us to create a new exposure module, characterized by a stable and reproducible radial guidance of the aerosol to the cells. The outcome was the CULTEX ® RFS (Mohr et al., 2010). In this study, we describe the differences between the two systems with regard to particle distribution and deposition clarifying the advantages and disadvantages of a radial to a linear aerosol distribution concept. Copyright © 2017 Elsevier GmbH. All rights reserved.

  9. Anisotropic Azimuthal Power and Temperature distribution on FuelRod. Impact on Hydride Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Motta, Arthur [Pennsylvania State Univ., State College, PA (United States); Ivanov, Kostadin [Pennsylvania State Univ., State College, PA (United States); Arramova, Maria [Pennsylvania State Univ., State College, PA (United States); Hales, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-29

    The degradation of the zirconium cladding may limit nuclear fuel performance. In the high temperature environment of a reactor, the zirconium in the cladding corrodes, releasing hydrogen in the process. Some of this hydrogen is absorbed by the cladding in a highly inhomogeneous manner. The distribution of the absorbed hydrogen is extremely sensitive to temperature and stress concentration gradients. The absorbed hydrogen tends to concentrate near lower temperatures. This hydrogen absorption and hydride formation can cause cladding failure. This project set out to improve the hydrogen distribution prediction capabilities of the BISON fuel performance code. The project was split into two primary sections, first was the use of a high fidelity multi-physics coupling to accurately predict temperature gradients as a function of r, θ , and z, and the second was to use experimental data to create an analytical hydrogen precipitation model. The Penn State version of thermal hydraulics code COBRA-TF (CTF) was successfully coupled to the DeCART neutronics code. This coupled system was verified by testing and validated by comparison to FRAPCON data. The hydrogen diffusion and precipitation experiments successfully calculated the heat of transport and precipitation rate constant values to be used within the hydrogen model in BISON. These values can only be determined experimentally. These values were successfully implemented in precipitation, diffusion and dissolution kernels that were implemented in the BISON code. The coupled output was fed into BISON models and the hydrogen and hydride distributions behaved as expected. Simulations were conducted in the radial, axial and azimuthal directions to showcase the full capabilities of the hydrogen model.

  10. A radial distribution function-based open boundary force model for multi-centered molecules

    KAUST Repository

    Neumann, Philipp; Eckhardt, Wolfgang; Bungartz, Hans-Joachim

    2014-01-01

    We derive an expression for radial distribution function (RDF)-based open boundary forcing for molecules with multiple interaction sites. Due to the high-dimensionality of the molecule configuration space and missing rotational invariance, a

  11. Optimization of a radially cooled pebble bed reactor - HTR2008-58117

    International Nuclear Information System (INIS)

    Boer, B.; Kloosterman, J. L.; Lathouwers, D.; Van Der Hagen, T. H. J. J.; Van Dam, H.

    2008-01-01

    By altering the coolant flow direction in a pebble bed reactor from axial to radial, the pressure drop can be reduced tremendously. In this case the coolant flows from the outer reflector through the pebble bed and finally to flow paths in the inner reflector. As a consequence, the fuel temperatures are elevated due to the reduced heat transfer of the coolant. However, the power profile and pebble size in a radially cooled pebble bed reactor can be optimized to achieve lower fuel temperatures than current axially cooled designs, while the low pressure drop can be maintained. The radial power profile in the core can be altered by adopting multi-pass fuel management using several radial fuel zones in the core. The optimal power profile yielding a flat temperature profile is derived analytically and is approximated by radial fuel zoning. In this case, the pebbles pass through the outer region of the core first and each consecutive pass is located in a fuel zone closer to the inner reflector. Thereby, the resulting radial distribution of the fissile material in the core is influenced and the temperature profile is close to optimal. The fuel temperature in the pebbles can be further reduced by reducing the standard pebble diameter from 6 cm to a value as low as I cm. An analytical investigation is used to demonstrate the effects on the fuel temperature and pressure drop for both radial and axial cooling. Finally, two-dimensional numerical calculations were performed, using codes for neutronics, thermal-hydraulics and fuel depletion analysis, in order to validate the results for the optimized design that were obtained from the analytical investigations. It was found that for a radially cooled design with an optimized power profile and reduced pebble diameter (below 3.5 cm) both a reduction in the pressure drop (Δp = -2.6 bar), which increases the reactor efficiency with several percent, and a reduction in the maximum fuel temperature (ΔT = -50 deg. C) can be achieved

  12. Relations between the matter density and layer thickness radial distributions in spherically symmetric objects: for high energy nuclear physics and astrophysics use

    International Nuclear Information System (INIS)

    Zielinska, M.; Zawislawski, Z.; Strugalska-Gola, E.; Strugalski, Z.

    1991-01-01

    It is shown how it is possible to transform known data on radial distribution of the matter layer thickness to unknown radial distribution of the matter density inside spherically symmetric objects. Appropriate formulas and testing of them are presented. An application of the method for the radial distribution of the matter density inside a target nucleus is discussed as an example. 2 refs.; 2 figs

  13. Small disturbances stability analysis applied in a radial distribution system with distributed generation units; Analise de estabilidade a pequenos disturbios aplicada em um sistema de distribuicao radial com unidades de geracao distribuida

    Energy Technology Data Exchange (ETDEWEB)

    Dorca, Daniel Azevedo; Camacho, Jose Roberto [Universidade Federal de Uberlandia (UFU), MG (Brazil). Curso de Mestrado em Engenharia Eletrica

    2008-07-01

    This work investigates the small-disturbance stability of a 30 bus radial distribution system with distributed generation units. This work is realized through the time domain simulations and through the eigenvalue analysis and participation factors. The eigenvalue analysis show that is possible to predict a possible system instability face to a disturbance. The development of this work was stimulated by the increasing of the distributed generation units in the distribution networks. (author)

  14. The Peculiar Radial Distribution of Multiple Populations in the Massive Globular Cluster M80

    Science.gov (United States)

    Dalessandro, E.; Cadelano, M.; Vesperini, E.; Salaris, M.; Ferraro, F. R.; Lanzoni, B.; Raso, S.; Hong, J.; Webb, J. J.; Zocchi, A.

    2018-05-01

    We present a detailed analysis of the radial distribution of light-element multiple populations (LE-MPs) in the massive and dense globular cluster M80, based on a combination of UV and optical Hubble Space Telescope data. Surprisingly, we find that first-generation (FG) stars (FG) are significantly more centrally concentrated than extreme second-generation (SG) stars out to ∼2.5r h from the cluster center. To understand the origin of such peculiar behavior, we used a set of N-body simulations following the long-term dynamical evolution of LE-MPs. We find that, given the advanced dynamical state of the cluster, the observed difference does not depend on the primordial relative distributions of FG and SG stars. On the contrary, a difference of ∼0.05–0.10 M ⊙ between the average masses of the two subpopulations is needed to account for the observed radial distributions. We argue that such a mass difference might be the result of the higher He abundance of SG stars (of the order of ΔY ∼ 0.05–0.06) with respect to FG stars. Interestingly, we find that a similar He variation is necessary to reproduce the horizontal branch morphology of M80. These results demonstrate that differences in mass among LE-MPs, due to different He content, should be properly taken into account for a correct interpretation of their radial distribution, at least in dynamically evolved systems.

  15. Performance of a high-work, low-aspect-ratio turbine stator tested with a realistic inlet radial temperature gradient

    Science.gov (United States)

    Stabe, Roy G.; Schwab, John R.

    1991-01-01

    A 0.767-scale model of a turbine stator designed for the core of a high-bypass-ratio aircraft engine was tested with uniform inlet conditions and with an inlet radial temperature profile simulating engine conditions. The principal measurements were radial and circumferential surveys of stator-exit total temperature, total pressure, and flow angle. The stator-exit flow field was also computed by using a three-dimensional Navier-Stokes solver. Other than temperature, there were no apparent differences in performance due to the inlet conditions. The computed results compared quite well with the experimental results.

  16. Temperature and boron dependencies of buckling and radial reflector saving for VVER lattices

    International Nuclear Information System (INIS)

    Alvarez, C.

    1990-01-01

    The temperature and boron dependencies of buckling and radial reflectors savings are analyzed in this paper on the basis of the results from the calculations ZR-6M critical assembly. These dependencies are related to the physical behavior of temperature and boron reactivity coefficients for the cores of VVER-type critical facilities. As a byproduct, the parameter was also investigated and its dependence on water density was determined

  17. The Radial Variation of the Solar Wind Temperature-Speed Relationship

    Science.gov (United States)

    Elliott, H. A.; McComas, D. J.

    2010-12-01

    Generally, the solar wind temperature (T) and speed (V) are well correlated except in Interplanetary Coronal Mass Ejections where this correlation breaks down. We have shown that at 1 AU the speed-temperature relationship is often well represented by a linear fit for a speed range spanning both the slow and fast wind. By examining all of the ACE and OMNI measurements, we found that when coronal holes are large the fast wind can have a different T-V relationship than the slow wind. The best example of this was in 2003 when there was a very large and long-lived outward polarity coronal hole at low latitudes. The long-lived nature of the hole made it possible to clearly distinguish that large holes can have a different T-V relationship. We found it to be rare that holes are large enough and last long enough to have enough data points to clearly demonstrate this effect. In this study we compare the 2003 coronal hole observations from ACE with the Ulysses polar coronal hole measurements. In an even earlier ACE study we found that both the compressions and rarefactions curves are linear, but the compression curve is shifted to higher temperatures. In this presentation we use Helios, Ulysses, and ACE measurements to examine how the T-V relationship varies with distance. The dynamic evolution of the solar wind parameters is revealed when we first separate compressions and rarefactions and then determine the radial profiles of the solar wind parameters. We find that T-V relationship varies with distance and in particular beyond 3 AU the differences between the compressions and rarefactions are quite important and at such distances a simple linear fit does not represent the T-V distribution very well.

  18. On the calculation of x-ray scattering signals from pairwise radial distribution functions

    DEFF Research Database (Denmark)

    Dohn, Asmus Ougaard; Biasin, Elisa; Haldrup, Kristoffer

    2015-01-01

    We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any possi...

  19. Evaluating the effect placement capacitor and distributed photovoltaic generation for power system losses minimization in radial distribution system

    Science.gov (United States)

    Rahman, Yuli Asmi; Manjang, Salama; Yusran, Ilham, Amil Ahmad

    2018-03-01

    Power loss minimization have many advantagess to the distribution system radial among others reduction of power flow in feeder lines, freeing stress on feeder loading, deterrence of power procurement from the grid and also the cost of loss compensating instruments. This paper, presents capacitor and photovoltaic (PV) placement as alternative means to decrease power system losses. The paper aims to evaluate the best alternative for decreasing power system losses and improving voltage profile in the radial distribution system. To achieve the objectives of paper, they are used three cases tested by Electric Transient and Analysis Program (ETAP) simulation. Firstly, it performs simulation of placement capacitor. Secondly, simulated placement of PV. Lastly, it runs simulation of placement capacitor and PV simultaneously. The simulations were validated using the IEEE 34-bus test system. As a result, they proved that the installation of capacitor and PV integration simultaneously leading to voltage profile correction and power losses minimization significantly.

  20. POLYANA-A tool for the calculation of molecular radial distribution functions based on Molecular Dynamics trajectories

    Science.gov (United States)

    Dimitroulis, Christos; Raptis, Theophanes; Raptis, Vasilios

    2015-12-01

    We present an application for the calculation of radial distribution functions for molecular centres of mass, based on trajectories generated by molecular simulation methods (Molecular Dynamics, Monte Carlo). When designing this application, the emphasis was placed on ease of use as well as ease of further development. In its current version, the program can read trajectories generated by the well-known DL_POLY package, but it can be easily extended to handle other formats. It is also very easy to 'hack' the program so it can compute intermolecular radial distribution functions for groups of interaction sites rather than whole molecules.

  1. Temperature and boron dependencies of buckling and radial reflector savings for VVER lattices

    International Nuclear Information System (INIS)

    Alvarez, C.

    1990-01-01

    The temperature and boron dependencies of buckling and radial reflector savings are analyzed in this paper on the basis of the results from the calculations for the ZR-6M critical assembly. These dependencies are related to he physical behaviour of temperature and boron reactivity coefficients for the cores of VVER-type critical facilities. As a byproduct, the dp/dBg 2 parameter was also investigated and its dependence on water density was determined

  2. Optimal Placement and Sizing of Renewable Distributed Generations and Capacitor Banks into Radial Distribution Systems

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar

    2017-06-01

    Full Text Available In recent years, renewable types of distributed generation in the distribution system have been much appreciated due to their enormous technical and environmental advantages. This paper proposes a methodology for optimal placement and sizing of renewable distributed generation(s (i.e., wind, solar and biomass and capacitor banks into a radial distribution system. The intermittency of wind speed and solar irradiance are handled with multi-state modeling using suitable probability distribution functions. The three objective functions, i.e., power loss reduction, voltage stability improvement, and voltage deviation minimization are optimized using advanced Pareto-front non-dominated sorting multi-objective particle swarm optimization method. First a set of non-dominated Pareto-front data are called from the algorithm. Later, a fuzzy decision technique is applied to extract the trade-off solution set. The effectiveness of the proposed methodology is tested on the standard IEEE 33 test system. The overall results reveal that combination of renewable distributed generations and capacitor banks are dominant in power loss reduction, voltage stability and voltage profile improvement.

  3. Radial transport processes as a precursor to particle deposition in drinking water distribution systems.

    Science.gov (United States)

    van Thienen, P; Vreeburg, J H G; Blokker, E J M

    2011-02-01

    Various particle transport mechanisms play a role in the build-up of discoloration potential in drinking water distribution networks. In order to enhance our understanding of and ability to predict this build-up, it is essential to recognize and understand their role. Gravitational settling with drag has primarily been considered in this context. However, since flow in water distribution pipes is nearly always in the turbulent regime, turbulent processes should be considered also. In addition to these, single particle effects and forces may affect radial particle transport. In this work, we present an application of a previously published turbulent particle deposition theory to conditions relevant for drinking water distribution systems. We predict quantitatively under which conditions turbophoresis, including the virtual mass effect, the Saffman lift force, and the Magnus force may contribute significantly to sediment transport in radial direction and compare these results to experimental observations. The contribution of turbophoresis is mostly limited to large particles (>50 μm) in transport mains, and not expected to play a major role in distribution mains. The Saffman lift force may enhance this process to some degree. The Magnus force is not expected to play any significant role in drinking water distribution systems. © 2010 Elsevier Ltd. All rights reserved.

  4. Stochastic Evaluation of Maximum Wind Installation in a Radial Distribution Network

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Bak-Jensen, Birgitte; Chen, Zhe

    2011-01-01

    This paper proposes an optimization algorithm to find the maximum wind installation in a radial distribution network. The algorithm imposes a limit on the amount of wind energy that can be curtailed annually. The algorithm implements the wind turbine reactive power control and wind energy...... curtailment using sensitivity factors. The optimization is integrated with Monte Carlo simulation to account for the stochastic behavior of load demand and wind power generation. The proposed algorithm is tested on a real 20 kV Danish distribution system in Støvring. It is demonstrated that the algorithm...... executes reactive compensation and energy curtailment sequentially in an effective and efficient manner....

  5. Analysis of the performance of fuel cells PWR with a single enrichment and radial distribution of enrichments

    International Nuclear Information System (INIS)

    Vargas, S.; Gonzalez, J. A.; Alonso, G.; Del Valle, E.; Xolocostli M, J. V.

    2008-01-01

    One of the main challenges in the design of fuel assemblies is the efficient use of uranium achieving burnt homogeneous of the fuel rods as well as the burnt maximum possible of the same ones to the unload. In the case of the assemblies type PWR has been decided actually for fuel assemblies with a single radial enrichment. The present work has like effect to show the because of this decision, reason why a comparison of the neutronic performance of two fuel cells takes place with the same enrichment average but one of them with radial distribution of enrichment and the other with a single enrichment equal to the average. The results shown in the present study of the behavior of the neutron flow as well as the power distribution through of assembly sustain the because of a single radial enrichment. (Author)

  6. Structure and temperature distribution of a stagnation-point Diesel spray premixed flame

    International Nuclear Information System (INIS)

    Lin, J.-C.; Lin, Ta-Hui

    2005-01-01

    We experimentally examine the flow and flame characteristics of a stagnation point premixed flame influenced by Diesel sprays. In the experiment, distributions of drop size, drop axial velocity and its fluctuation as well as the gas phase temperature are measured by using the phase-doppler particle analyzer and a thin thermocouple. As might be expected, similar to the gasoline spray flame, the partially prevaporized Diesel spray flame is composed of a weak blue flame zone, indicating the burning of methane fuel, and a strongly luminous zone containing many bright yellow lines showing the passages of burning Diesel drops. It is found that the axial temperature profiles at various radial positions consist of an upstream preheat region, a maximum temperature downstream of the blue flame and a downstream region with a declined temperature curve because of the heat loss to the quartz plate. The SMD of the drops increases from the upstream preheat region to a maximum near the blue flame and then decreases in the downstream burning zone. Along the axial position, the drops are decelerated in front of the flame but accelerated when passing through the blue flame. It is also interesting to note that the radial distributions of SMD and number density of drops in the upstream region are mainly influenced by small drops flowing outward, since the upstream vaporization of Diesel drops is very limited; while those in the downstream region should be influenced by both small drops flowing outward and Diesel drops burning. From the experimental observations, there are impinging and bouncing of Diesel drops downstream of the spray flame near the quartz plate, resulting in a small amount of soot and carbon deposits on the wall. These interesting phenomena will be reported in the near future

  7. Radial density distribution of a warm dense plasma formed by underwater electrical explosion of a copper wire

    Science.gov (United States)

    Nitishinskiy, M.; Yanuka, D.; Virozub, A.; Krasik, Ya. E.

    2017-12-01

    Time- and space-resolved evolution of the density (down to 0.07 of solid state density) of a copper wire during its microsecond timescale electrical explosion in water was obtained by X-ray backlighting. In the present research, a flash X-ray source of 20 ns pulse-width and >60 keV photon energy was used. The conductivity of copper was evaluated for a temperature of 10 kK and found to be in good agreement with the data obtained in earlier experiments [DeSilva and Katsouros, Phys. Rev. E 57, 5945 (1998) and Sheftman and Krasik, Phys. Plasmas 18, 092704 (2011)] where only electrical and optical diagnostics were applied. Magneto-hydrodynamic simulation shows a good agreement between the simulated and experimental waveforms of the current and voltage and measured the radial expansion of the exploding wire. Also, the radial density distribution obtained by an inverse Abel transform analysis agrees with the results of these simulations. Thus, the validity of the equations of state for copper and the conductivity model used in the simulations was confirmed for the parameters of the exploding wire realized in the present research.

  8. Heuristic for solving capacitor allocation problems in electric energy radial distribution networks

    Directory of Open Access Journals (Sweden)

    Maria A. Biagio

    2012-04-01

    Full Text Available The goal of the capacitor allocation problem in radial distribution networks is to minimize technical losses with consequential positive impacts on economic and environmental areas. The main objective is to define the size and location of the capacitors while considering load variations in a given horizon. The mathematical formulation for this planning problem is given by an integer nonlinear mathematical programming model that demands great computational effort to be solved. With the goal of solving this problem, this paper proposes a methodology that is composed of heuristics and Tabu Search procedures. The methodology presented explores network system characteristics of the network system reactive loads for identifying regions where procedures of local and intensive searches should be performed. A description of the proposed methodology and an analysis of computational results obtained which are based on several test systems including actual systems are presented. The solutions reached are as good as or better than those indicated by well referenced methodologies. The technique proposed is simple in its use and does not require calibrating an excessive amount of parameters, making it an attractive alternative for companies involved in the planning of radial distribution networks.

  9. Analysis of the temperature and stress distributions in ceramic window materials subjected to microwave heating

    International Nuclear Information System (INIS)

    Ferber, M.K.; Kimrey, H.D.; Becher, P.F.

    1983-07-01

    The temperature and stress and distributions generated in ceramic materials currently employed in microwave gyrotron tube windows were determined for a variety of operating conditions. Both edge- and face-cooled windows of either polycrystalline BeO or polycrystalline Al 2 O 3 were considered. The actual analysis involved three steps. First, a computer program was used to determine the electric field distribution within the window at a given power level and frequency (TE 02 wave propagation assumed). This program was capable of describing both the radial and axial dependence of the electric field. The effects of multiple internal reflections at the various dielectric interfaces were also accounted for. Secondly, the field distribution was used to derive an expression for the heat generated per unit volume per unit time within the window due to dieletric losses. A generalized heat conduction computer code was then used to compute the temperature distribution based on the heat generation function. Third, the stresses were determined from the temperature profiles using analytical expression or a finite-element computer program. Steady-state temperature and stress profiles were computed for the face-cooled and edge-cooled windows

  10. THE STRESS STATE OF THE RADIALLY INHOMOGENEOUS HEMISPHERICAL SHELL UNDER LOCALLY DISTRIBUTED VERTICAL LOAD

    Directory of Open Access Journals (Sweden)

    Andreev Vladimir Igorevich

    2018-01-01

    Full Text Available Subject: one of the promising trends in the development of structural mechanics is the development of methods for solving problems in the theory of elasticity for bodies with continuous inhomogeneity of any deformation characteristics: these methods make it possible to use the strength of the material most fully. In this paper, we consider the two-dimensional problem for the case when a vertical, locally distributed load acts on the hemisphere and the inhomogeneity is caused by the influence of the temperature field. Research objectives: derive governing system of equations in spherical coordinates for determination of the stress state of the radially inhomogeneous hemispherical shell under locally distributed vertical load. Materials and methods: as a mechanical model, we chose a thick-walled reinforced concrete shell (hemisphere with inner and outer radii a and b, respectively, b > a. The shell’s parameters are a = 3.3 m, b = 4.5 m, Poisson’s ratio ν = 0.16; the load parameters are f = 10MPa - vertical localized load distributed over the outer face, θ0 = 30°, temperature on the internal surface of the shell Ta = 500 °C, temperature on the external surface of the shell Tb = 0 °C. The resulting boundary-value problem (a system of differential equations with variable coefficients is solved using the Maple software package. Results: maximal compressive stresses σr with allowance for material inhomogeneity are reduced by 10 % compared with the case when the inhomogeneity is ignored. But it is not so important compared with a 3-fold decrease in the tensile stress σθ on the inner surface and a 2-fold reduction in the tensile stress σθ on the outer surface of the hemisphere as concretes generally have a tensile strength substantially smaller than the compressive strength. Conclusions: the method presented in this article makes it possible to reduce the deformation characteristics of the material, i.e. it leads to a reduction in stresses

  11. Multiagent System-Based Distributed Coordinated Control for Radial DC Microgrid Considering Transmission Time Delays

    DEFF Research Database (Denmark)

    Dou, Chun-Xia; Yue, Dong; Guerrero, Josep M.

    2017-01-01

    This paper focuses on a multi-agent based distributed coordinated control for radial DC microgrid considering trans-mission time delays. Firstly, a two-level multi-agent system is constructed, where local control is formulated based on local states and executed by means of the first-level agent......, and dis-tributed coordinated control law is formulated based on wide-area information and executed by means of the secondary- level agent in order to improve the voltage control performances. Afterwards, the research mainly focuses on designing the local controller and the distributed coordinated...

  12. Design and theoretical analysis of a sliding valve distribution radial piston pump

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Guo; Shengdun, Zhao; Yanghuiwen, Yu [Xian Jiaotong University, Xian (China); Peng, Shang [Xian Engineering University of Armed Police Force, Xian (China)

    2016-01-15

    A Sliding valve distribution radial piston pump (SVDRPP) is presented. In this pump, a new distribution method that uses sliding valves to distribute oil for the piston chambers is developed. With this design, the disadvantages brought by the distribution shaft and the check valves (traditional distribution mechanisms), such as the poor stress state of the shaft and the energy waste for opening the check valves, are expected to be eliminated. In addition, a method of using pressure oil to accomplish the returning stroke of the piston is also proposed, which could be used to replace the usage of springs along with their shortcomings. A pump with five pistons is designed as an example to elaborate the structure and the working principle of SVDRPP. Furthermore, the flow characteristics of SVDRPP are studied, and the formulas of the displacement, the average flow rate and the instantaneous flow rate are deduced.

  13. Design and theoretical analysis of a sliding valve distribution radial piston pump

    International Nuclear Information System (INIS)

    Tong, Guo; Shengdun, Zhao; Yanghuiwen, Yu; Peng, Shang

    2016-01-01

    A Sliding valve distribution radial piston pump (SVDRPP) is presented. In this pump, a new distribution method that uses sliding valves to distribute oil for the piston chambers is developed. With this design, the disadvantages brought by the distribution shaft and the check valves (traditional distribution mechanisms), such as the poor stress state of the shaft and the energy waste for opening the check valves, are expected to be eliminated. In addition, a method of using pressure oil to accomplish the returning stroke of the piston is also proposed, which could be used to replace the usage of springs along with their shortcomings. A pump with five pistons is designed as an example to elaborate the structure and the working principle of SVDRPP. Furthermore, the flow characteristics of SVDRPP are studied, and the formulas of the displacement, the average flow rate and the instantaneous flow rate are deduced

  14. Channeling of protons through radial deformed carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Borka Jovanović, V., E-mail: vborka@vinca.rs [Atomic Physics Laboratory (040), Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Borka, D. [Atomic Physics Laboratory (040), Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Galijaš, S.M.D. [Faculty of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade (Serbia)

    2017-05-18

    Highlights: • For the first time we presented theoretically obtained distributions of channeled protons with radially deformed SWNT. • Our findings indicate that influence of the radial deformation is very strong and it should not be omitted in simulations. • We show that the spatial and angular distributions depend strongly of level of radial deformation of nanotube. • Our obtained results can be compared with measured distributions to reveal the presence of various types of defects in SWNT. - Abstract: In this paper we have presented a theoretical investigation of the channeling of 1 GeV protons with the radial deformed (10, 0) single-wall carbon nanotubes (SWNTs). We have calculated channeling potential within the deformed nanotubes. For the first time we presented theoretically obtained spatial and angular distributions of channeled protons with radially deformed SWNT. We used a Monte Carlo (MC) simulation technique. We show that the spatial and angular distributions depend strongly of level of radial deformation of nanotube. These results may be useful for nanotube characterization and production and guiding of nanosized ion beams.

  15. Reconstruction of Daily Sea Surface Temperature Based on Radial Basis Function Networks

    Directory of Open Access Journals (Sweden)

    Zhihong Liao

    2017-11-01

    Full Text Available A radial basis function network (RBFN method is proposed to reconstruct daily Sea surface temperatures (SSTs with limited SST samples. For the purpose of evaluating the SSTs using this method, non-biased SST samples in the Pacific Ocean (10°N–30°N, 115°E–135°E are selected when the tropical storm Hagibis arrived in June 2014, and these SST samples are obtained from the Reynolds optimum interpolation (OI v2 daily 0.25° SST (OISST products according to the distribution of AVHRR L2p SST and in-situ SST data. Furthermore, an improved nearest neighbor cluster (INNC algorithm is designed to search for the optimal hidden knots for RBFNs from both the SST samples and the background fields. Then, the reconstructed SSTs from the RBFN method are compared with the results from the OI method. The statistical results show that the RBFN method has a better performance of reconstructing SST than the OI method in the study, and that the average RMSE is 0.48 °C for the RBFN method, which is quite smaller than the value of 0.69 °C for the OI method. Additionally, the RBFN methods with different basis functions and clustering algorithms are tested, and we discover that the INNC algorithm with multi-quadric function is quite suitable for the RBFN method to reconstruct SSTs when the SST samples are sparsely distributed.

  16. Numerical Simulation and Experimental Study on Temperature Distribution of Self-Lubricating Packing Rings in Reciprocating Compressors

    Directory of Open Access Journals (Sweden)

    Jia Xiaohan

    2016-01-01

    Full Text Available The nonuniform abrasion failure and high-temperature thermal failure of packing rings have a significant influence on compressor reliability, particularly that of oil-free compressors. In this study, a test rig was constructed to measure the dynamic temperature of packing rings under different operational conditions in an oil-free reciprocating compressor. The dynamic axial and radial temperature distributions of the packing rings were obtained using an innovative internal temperature testing device that kept the thermocouples and packing box relatively static during compressor operation. A three-dimensional heat transfer model was also developed to analyze the temperature distribution of the packing boxes, piston rod, and cylinder during such operation. Good agreement was observed between the simulation results and experimental data, which showed an average relative error of less than 2.35%. The results indicate that the pressure ratio exerts a significant effect on the axial temperature distribution and determines which packing ring reaches the maximum temperature. They also show the average temperature to rise with an increase in the rotational speed and to fall with an improvement in the external cooling conditions. Finally, the material of the packing rings was found to affect the temperature gradient from their inner to outer surface.

  17. Multi-objective PSO based optimal placement of solar power DG in radial distribution system

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar

    2017-06-01

    Full Text Available Ever increasing trend of electricity demand, fossil fuel depletion and environmental issues request the integration of renewable energy into the distribution system. The optimal planning of renewable distributed generation (DG is much essential for ensuring maximum benefits. Hence, this paper proposes the optimal placement of probabilistic based solar power DG into the distribution system. The two objective functions such as power loss reduction and voltage stability index improvement are optimized. The power balance and voltage limits are kept as constraints of the problem. The non-sorting pare to-front based multi-objective particle swarm optimization (MOPSO technique is proposed on standard IEEE 33 radial distribution test system.

  18. Analysis on nondestructive temperature distribution of tire tread part in a running using infrared thermal vision camera

    International Nuclear Information System (INIS)

    Kim, Jae Yeol; Yang, Dong Jo; Ma, Sang Dong; Park, Byoung Gu; Lee, Ju Wan

    2001-01-01

    The experimental method which investigates validity of numerical simulation for wheeling tires has not developed until now. Separation of belt caused by sudden temperature increase is the most serious problem with wheeling tires. Actually, separation of belt is closely related with the life cycle and design of tires. It is important to investigate the temperature history of tires because sudden temperature increase on belt accelerates the thermal fatigue and then causes the destruction of bending area in the radial direction. Therefore, in the present study, finite element method (FEM) was used to obtain the accurate temperature distribution of tire. Its results were compared with experimental data acquired by infrared thermal camera.

  19. Research on stress distribution regularity of cement sheaths of radial well based on ABAQUS

    Science.gov (United States)

    Shi, Jihui; Cheng, Yuanfang; Li, Xiaolong; Xiao, Wen; Li, Menglai

    2017-12-01

    To ensure desirable outcome of hydraulic fracturing based on ultra-short radius radial systems, it is required to investigate the stress distribution regularity and stability of the cement sheath. On the basis of the theoretical model of the cement sheath stress distribution, a reservoir mechanical model was built using the finite element software, ABAQUS, according to the physical property of a certain oil reservoir of the Shengli oilfield. The stress distribution of the casing-cement-sheath-formation system under the practical condition was simulated, based on which analyses were conducted from multiple points of view. Results show that the stress on the internal interface of the cement sheath exceeds that on the external interface, and fluctuates with higher amplitudes, which means that the internal interface is the most failure-prone. The unevenness of the cement sheath stress distribution grows with the increasing horizontal principal stress ratio, and so does the variation magnitude. This indicates that higher horizontal principal stress ratios are unfavourable for the structural stability of the cement sheath. Both the wellbore quantity of the URRS and the physical property of the material can affect the cement sheath distribution. It is suggested to optimize the quantity of the radial wellbore and use cement with a lower elastic modulus and higher Poisson’s ratio. At last, the impact level of the above factor was analysed, with the help of the grey correlation analysis.

  20. Oxygen distribution in packed-bed membrane reactors for partial oxidations: effect of the radial porosity profiles on the product selectivity

    NARCIS (Netherlands)

    Kurten, U.; van Sint Annaland, M.; Kuipers, J.A.M.

    2004-01-01

    A two-dimensional, pseudohomogeneous reactor model was presented to describe the radial and axial concentration profiles in a packed-bed membrane reactor and the local velocity field while accounting for the influences due to the distributive membrane flow and the radial porosity profile. The effect

  1. Radial distribution of ions in pores with a surface charge

    NARCIS (Netherlands)

    Stegen, J.H.G. van der; Görtzen, J.; Kuipers, J.A.M.; Hogendoorn, J.A.; Versteeg, G.F.

    2001-01-01

    A sorption model applicable to calculate the radial equilibrium concentrations of ions in the pores of ion-selective membranes with a pore structure is developed. The model is called the radial uptake model. Because the model is applied to a Nafion sulfonic layer with very small pores and the radial

  2. The Effects of Radial and Poloidal ExB Drifts in the Tokamak SOL

    International Nuclear Information System (INIS)

    Ou Jing; Zhu Sizheng

    2006-01-01

    The effects of radial and poloidal ExB drifts in the scrape-off layer (SOL) of a limiter tokamak are studied with a one-dimensional fluid code. The transport equations are solved in the poloidal direction with the radial influxes as the source terms. The simulation results show that in the high recycling regime, the effect of the radial ExB drift on plasma density tends to be stronger than that of the poloidal ExB drift. In the sheath-limited regime, the effects of the radial ExB drift and poloidal ExB drift on plasma density are almost equally important. Considering the influence on the electron temperature, the poloidal ExB drift tends to be more important than the radial ExB drift in both the high recycling regime and sheath-limited regime. For the normal B φ , the poloidal ExB drift tends to raise the pressure at the low field side while the radial ExB drift favours the high field side. The simulation results also show that the ExB drift influences the asymmetries on the parameter distributions at the high field side and low field side, and the distributions are much more symmetric with the field reversal

  3. Radial distribution of the contributions to band broadening of a silica-based semi-preparative monolithic column.

    Science.gov (United States)

    Abia, Jude A; Mriziq, Khaled S; Guiochon, Georges A

    2009-04-01

    Using an on-column local electrochemical microdetector operated in the amperometric mode, band elution profiles were recorded at different radial locations at the exit of a 10 mm id, 100 mm long silica-based monolithic column. HETP plots were then acquired at each of these locations, and all these results were fitted to the Knox equation. This provided a spatial distribution of the values of the eddy diffusion (A), the molecular diffusion (B), and the resistance to the kinetics of mass transfer (C) terms. Results obtained indicate that the wall region yields higher A values and smaller C values than the central core region. Significant radial fluctuations of these contributions to band broadening occur throughout the exit column cross-section. This phenomenon is due to the structural radial heterogeneity of the column.

  4. Determination and analysis of neutron flux distribution on radial Piercing beam port for utilization of Kartini research reactor

    International Nuclear Information System (INIS)

    Widarto

    2002-01-01

    Determination and analysis of neutron flux measurements on radial piercing beam port have been done as completion experimental data document and progressing on utilization of the Kartini research reactor purposes. The analysis and determination of the neutron flux have been carried out by using Au foils detector neutron activation analysis method which put on the radius of cross section (19 cm) and a long of radial piercing beam port (310 cm) Based on the calculation, distribution of the thermal neutron flux is around (8.3 ± 0.9) x 10 5 ncm -2 s -1 to (6.8 ± 0.5) x 10 7 ncm -2 s -1 and fast neutron is (5.0 ± 0.2) x 10 5 ncm -2 s -1 to (1.43 ± 0.6) x 10 7 ncm -2 s -1 . Analyzing by means of curve fitting method could be concluded that the neutron flux distribution on radial piercing beam port has profiled as a polynomial curve. (author)

  5. The radial distribution of cosmic rays in the heliosphere at solar maximum

    Science.gov (United States)

    McDonald, F. B.; Fujii, Z.; Heikkila, B.; Lal, N.

    2003-08-01

    To obtain a more detailed profile of the radial distribution of galactic (GCRs) and anomalous (ACRs) cosmic rays, a unique time in the 11-year solar activity cycle has been selected - that of solar maximum. At this time of minimum cosmic ray intensity a simple, straight-forward normalization technique has been found that allows the cosmic ray data from IMP 8, Pioneer 10 (P-10) and Voyagers 1 and 2 (V1, V2) to be combined for the solar maxima of cycles 21, 22 and 23. This combined distribution reveals a functional form of the radial gradient that varies as G 0/r with G 0 being constant and relatively small in the inner heliosphere. After a transition region between ˜10 and 20 AU, G 0 increases to a much larger value that remains constant between ˜25 and 82 AU. This implies that at solar maximum the changes that produce the 11-year modulation cycle are mainly occurring in the outer heliosphere between ˜15 AU and the termination shock. These observations are not inconsistent with the concept that Global Merged Interaction. regions (GMIRs) are the principal agent of modulation between solar minimum and solar maximum. There does not appear to be a significant change in the amount of heliosheath modulation occurring between the 1997 solar minimum and the cycle 23 solar maximum.

  6. Measurement of distribution coefficients using a radial injection dual-tracer test

    International Nuclear Information System (INIS)

    Pickens, J.F.; Jackson, R.E.; Inch, K.J.; Merritt, W.F.

    1981-01-01

    The dispersive and adsorptive properties of a sandy aquifer were evaluated by using a radial injection dual-tracer test with 131 I as the nonreactive tracer and 85 Sr as the reactive tracer. The tracer migration was monitored by using multilevel point-sampling devices located at various radial distances and depths. Nonequilibrium physical and chemical adsorption effects for 85 Sr were treated as a spreading or dispersion mechanism in the breakthrough curve analysis. The resulting effective dispersivity values for 85 Sr were typically a factor of 2 to 5 larger than those obtained for 131 I. The distribution coefficient (K/sub d//sup Sr/) values obtained from analysis of the breakthrough curves at three depths and two radial distances ranged from 2.6 to 4.5 ml/g. These compare favorably with values obtained by separation of fluids from solids in sediment cores, by batch experiments on core sediments and by analysis of a 25-year-old radioactive waste plume in another part of the same aquifer. Correlations of adsorbed 85 Sr radioactivity with grain size fractions demonstrated preferential adsorption to the coarsest fraction and to the finest fraction. The relative amounts of electrostatically and specifically adsorbed 85 Sr on the aquifer sediments were determined with desorption experiments on core sediments using selective chemical extractants. The withdrawal phase breakthrough curves for the well, obtained immediately following the injection phase, showed essentially full tracer recoveries for both 131 I and 85 Sr. Relatively slow desorption of 85 Sr provided further indication of the nonequilibrium nature of the adsorption-desorption phenomena

  7. Measurement of the temperature distribution inside the power cable using distributed temperature system

    Science.gov (United States)

    Jaros, Jakub; Liner, Andrej; Papes, Martin; Vasinek, Vladimir; Mach, Veleslav; Hruby, David; Kajnar, Tomas; Perecar, Frantisek

    2015-01-01

    Nowadays, the power cables are manufactured to fulfill the following condition - the highest allowable temperature of the cable during normal operation and the maximum allowable temperature at short circuit conditions cannot exceed the condition of the maximum allowable internal temperature. The distribution of the electric current through the conductor leads to the increase of the amplitude of electrons in the crystal lattice of the cables material. The consequence of this phenomenon is the increase of friction and the increase of collisions between particles inside the material, which causes the temperature increase of the carrying elements. The temperature increase is unwanted phenomena, because it is causing losses. In extreme cases, the long-term overload leads to the cable damaging or fire. This paper deals with the temperature distribution measurement inside the power cables using distributed temperature system. With cooperation with Kabex company, the tube containing optical fibers was installed into the center of power cables. These fibers, except telecommunications purposes, can be also used as sensors in measurements carrying out with distributed temperature system. These systems use the optical fiber as a sensor and allow the continual measurement of the temperature along the whole cable in real time with spatial resolution 1 m. DTS systems are successfully deployed in temperature measurement applications in industry areas yet. These areas include construction, drainage, hot water etc. Their advantages are low cost, resistance to electromagnetic radiation and the possibility of real time monitoring at the distance of 8 km. The location of the optical fiber in the center of the power cable allows the measurement of internal distribution of the temperature during overloading the cable. This measurement method can be also used for prediction of short-circuit and its exact location.

  8. REVERSED TREND OF RADIAL DISTRIBUTION OF SUBPOPULATIONS IN THE GLOBULAR CLUSTERS NGC 362 AND NGC 6723

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Dongwook; Lee, Young-Wook; Pasquato, Mario [Center for Galaxy Evolution Research and Department of Astronomy, Yonsei University, Seoul 03722 (Korea, Republic of); Han, Sang-Il; Roh, Dong-Goo, E-mail: dwlim@galaxy.yonsei.ac.kr, E-mail: ywlee2@yonsei.ac.kr [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of)

    2016-12-01

    Most globular clusters (GCs) are now known to host multiple stellar populations with different abundances of light elements. Here we use narrow-band photometry and low-resolution spectroscopy for NGC 362 and NGC 6723 to investigate their chemical properties and radial distributions of subpopulations. We confirm that NGC 362 and NGC 6723 are among the GCs with multiple populations showing bimodal CN distribution and CN–CH anticorrelation without a significant spread in calcium abundance. These two GCs show more centrally concentrated CN-weak, earlier generation stars compared to the CN-strong, later generation stars. These trends are reversed with respect to those found in previous studies for many other GCs. Our findings, therefore, seem contradictory to the current scenario for the formation of multiple stellar populations, but mass segregation acting on the two subpopulations might be a possible solution to explain this reversed radial trend.

  9. SU-F-18C-11: Diameter Dependency of the Radial Dose Distribution in a Long Polyethylene Cylinder

    Energy Technology Data Exchange (ETDEWEB)

    Bakalyar, D; McKenney, S [Henry Ford Health System, Detroit, MI (United States); Feng, W [New York Presbyterian Hospital, Tenafly, NJ (United States)

    2014-06-15

    Purpose: The radial dose distribution in the central plane of a long cylinder following a long CT scan depends upon the diameter and composition of the cylinder. An understanding of this behavior is required for determining the spatial average of the dose in the central plane. Polyethylene, the material for construction of the TG200/ICRU phantom (30 cm in diameter) was used for this study. Size effects are germane to the principles incorporated in size specific dose estimates (SSDE); thus diameter dependency was explored as well. Method: ssuming a uniform cylinder and cylindrically symmetric conditions of irradiation, the dose distribution can be described using a radial function. This function must be an even function of the radial distance due to the conditions of symmetry. Two effects are accounted for: The direct beam makes its weakest contribution at the center while the contribution due to scatter is strongest at the center and drops off abruptly at the outer radius. An analytic function incorporating these features was fit to Monte Carlo results determined for infinite polyethylene cylinders of various diameters. A further feature of this function is that it is integrable. Results: Symmetry and continuity dictate a local extremum at the center which is a minimum for the larger sizes. The competing effects described above can Resultin an absolute maximum occurring between the center and outer edge of the cylinders. For the smallest cylinders, the maximum dose may occur at the center. Conclusion: An integrable, analytic function can be used to characterize the radial dependency of dose for cylindrical CT phantoms of various sizes. One use for this is to help determine average dose distribution over the central cylinder plane when equilibrium dose has been reached.

  10. Vertical, radial and drag force analysis of superconducting magnetic bearings

    International Nuclear Information System (INIS)

    Cansiz, Ahmet

    2009-01-01

    The behavior of the force between a permanent magnet (PM) and a high temperature superconductor (HTS) was tested with the frozen-image model based on flux pinning. It was found that the associated dipole moment assumptions of the method of the frozen image underestimate the force somewhat; thus a quadrupole moment analysis is proposed. The radial and drag forces associated with the rotation of the PM levitated above the HTS were measured by using a force transducer and by means of a cantilevered beam technique. The radial force was found not to be dependent on the radial direction, and the least radial force was found to be periodic with an angular displacement during the slow rotation of the PM relative to the HTS. The periodicity behavior of the force is attributed to the geometric eccentricity from the magnetization distribution of the PM and HTS. The drag force associated with the torsional stiffness of the levitated PM during the low and high rotational speeds was incorporated with the data from the literature.

  11. Reconstruction of core inlet temperature distribution by cold leg temperature measurements

    International Nuclear Information System (INIS)

    Saarinen, S.; Antila, M.

    2010-01-01

    The reduced core of Loviisa NPP contains 33 thermocouple measurements measuring the core inlet temperature. Currently, these thermocouple measurements are not used in determining the inlet temperature distribution. The average of cold leg temperature measurements is used as inlet temperature for each fuel assembly. In practice, the inlet temperature distribution is not constant. Thus, using a constant inlet temperature distribution induces asymmetries in the measured core power distribution. Using a more realistic inlet temperature distribution would help us to reduce virtual asymmetries of the core power distribution and increase the thermal margins of the core. The thermocouples at the inlet cannot be used directly to measure the inlet temperature accurately because the calibration of the thermocouples that is done at hot zero power conditions is no longer valid at full power, when there is temperature change across the core region. This is due to the effect of neutron irradiation on the Seebeck coefficient of the thermocouple wires. Therefore, we investigate in this paper a method to determine the inlet temperature distribution based on the cold leg temperature measurements. With this method we rely on the assumption that although the core inlet thermocouple measurements do not measure the absolute temperature accurately they do measure temperature changes with sufficient accuracy particularly in big disturbances. During the yearly testing of steam generator safety valves we observe a large temperature increase up to 12 degrees in the cold leg temperature. The change in the temperature of one of the cold legs causes a local disturbance in the core inlet temperature distribution. Using the temperature changes observed in the inlet thermocouple measurements we are able to fit six core inlet temperature response functions, one for each cold leg. The value of a function at an assembly inlet is determined only by the corresponding cold leg temperature disturbance

  12. A simplified treatment of radial enrichment distributions of LWR fuel assemblies in criticality calculations

    International Nuclear Information System (INIS)

    Hennebach, M.; Schnorrenberg, N.

    2008-01-01

    Criticality safety assessments are usually performed for fuel assembly models that are as generic as possible to encompass small modifications in geometry that have no impact on criticality. Dealing with different radial enrichment distributions for a fuel assembly type, which is especially important for BWR fuel, poses more of a challenge, since this characteristic is rather obviously influencing the neutronic behaviour of the system. Nevertheless, the large variability of enrichment distributions makes it very desirable and even necessary to treat them in a generalized way, both to keep the criticality safety assessment from becoming too unwieldy and to avoid having to extend it every time a new variation comes up. To be viable, such a generic treatment has to be demonstrably covering, i.e. lead to a higher effective neutron multiplication factor k eff than any of the radial enrichment distributions it represents. Averaging the enrichment evenly over the fuel rods of the assembly is a general and simple approach, and under reactor conditions, it is also a covering assumption: the graded distribution is introduced to achieve a linear power distribution, therefore reducing the enrichment of the better moderated rods at the edge of the assembly. With an even distribution of the average enrichment over all rods, these wellmoderated rods will cause increased fission rates at the assembly edges and a rise in k eff . Since the moderator conditions in a spent nuclear fuel cask differ strongly from a reactor even when considering optimal moderation, the proof that a uniform enrichment distribution is a covering assumption compared with detailed enrichment distributions has to be cask-specific. In this report, a method for making that proof is presented along with results for fuel assemblies from BWR reactors. All results are from three-dimensional Monte Carlo calculations with the SCALE 5.1 code package [1], using a 44-group neutron crosssection library based on ENDF

  13. RADIAL DISTRIBUTION OF STARS, GAS AND DUST IN SINGS GALAXIES. I. SURFACE PHOTOMETRY AND MORPHOLOGY

    International Nuclear Information System (INIS)

    Munoz-Mateos, J. C.; Gil de Paz, A.; Zamorano, J.

    2009-01-01

    We present ultraviolet through far-infrared (FIR) surface brightness profiles for the 75 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS). The imagery used to measure the profiles includes Galaxy Evolution Explorer UV data, optical images from Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and Sloan Digital Sky Survey, near-IR data from Two Micron All Sky Survey, and mid- and FIR images from Spitzer. Along with the radial profiles, we also provide multi-wavelength asymptotic magnitudes and several nonparametric indicators of galaxy morphology: the concentration index (C 42 ), the asymmetry (A), the Gini coefficient (G), and the normalized second-order moment of the brightest 20% of the galaxy's flux (M-bar 20 ). In this paper, the first of a series, we describe the technical aspects regarding the surface photometry, and present a basic analysis of the global and structural properties of the SINGS galaxies at different wavelengths. The homogeneity in the acquisition, reduction, and analysis of the results presented here makes these data ideal for multiple unanticipated studies on the radial distribution of the properties of stars, dust, and gas in galaxies. Our radial profiles show a wide range of morphologies and multiple components (bulges, exponential disks, inner and outer disk truncations, etc.) that vary not only from galaxy to galaxy but also with wavelength for a given object. In the optical and near-IR, the SINGS galaxies occupy the same regions in the C 42 -A-G-M-bar 20 parameter space as other normal galaxies in previous studies. However, they appear much less centrally concentrated, more asymmetric, and with larger values of G when viewed in the UV (due to star-forming clumps scattered across the disk) and in the mid-IR (due to the emission of polycyclic aromatic hydrocarbons at 8.0 μm and very hot dust at 24 μm). In an accompanying paper by Munoz-Mateos et al., we focus on the radial distribution of dust

  14. Calculation of the radial dose distribution around the trajectory of an ion

    International Nuclear Information System (INIS)

    Pretzsch, G.

    1979-01-01

    The dose caused in polyester by incoming protons, alpha beams, 127 I ions, and 16 O ions has been calculated as a function of the distance perpendicularly to their trajectory. Based on simplified assumptions regarding the binding state of target electrons, emission of secondary electrons and their propagation in matter, it has been found that the dose depends on the distance to the ion trajectory (R) in the form Rsup(-l), l being about 2. The calculated radial dose distributions agree well with values calculated or measured by other authors

  15. A Novel Analytical Technique for Optimal Allocation of Capacitors in Radial Distribution Systems

    Directory of Open Access Journals (Sweden)

    Sarfaraz Nawaz

    2017-07-01

    Full Text Available In this paper, a novel analytical technique is proposed to determine the optimal size and location of shunt capacitor units in radial distribution systems. An objective function is formulated to reduce real power loss, to improve the voltage profile and to increase annual cost savings. A new constant, the Loss Sensitivity Constant (LSC, is proposed here. The value of LSC decides the location and size of candidate buses. The technique is demonstrated on an IEEE-33 bus system at different load levels and the 130-bus distribution system of Jamawa Ramgarh village, Jaipur city. The obtained results are compared with the latest optimization techniques to show the effectiveness and robustness of the proposed technique.

  16. Impact of Brake Pad Structure on Temperature and Stress Fields of Brake Disc

    OpenAIRE

    Wang, Guoshun; Fu, Rong

    2013-01-01

    Utilizing ABAQUS finite element software, the study established the relationship between a brake pad structure and distributions of temperature and thermal stress on brake disc. By introducing radial structure factor and circular structure factor concepts, the research characterized the effect of friction block radial and circumferential arrangement on temperature field of the brake disc. A method was proposed for improving heat flow distribution of the brake disc through optimizing the posit...

  17. Study on the properties of infrared wavefront coding athermal system under several typical temperature gradient distributions

    Science.gov (United States)

    Cai, Huai-yu; Dong, Xiao-tong; Zhu, Meng; Huang, Zhan-hua

    2018-01-01

    Wavefront coding for athermal technique can effectively ensure the stability of the optical system imaging in large temperature range, as well as the advantages of compact structure and low cost. Using simulation method to analyze the properties such as PSF and MTF of wavefront coding athermal system under several typical temperature gradient distributions has directive function to characterize the working state of non-ideal temperature environment, and can effectively realize the system design indicators as well. In this paper, we utilize the interoperability of data between Solidworks and ZEMAX to simplify the traditional process of structure/thermal/optical integrated analysis. Besides, we design and build the optical model and corresponding mechanical model of the infrared imaging wavefront coding athermal system. The axial and radial temperature gradients of different degrees are applied to the whole system by using SolidWorks software, thus the changes of curvature, refractive index and the distance between the lenses are obtained. Then, we import the deformation model to ZEMAX for ray tracing, and obtain the changes of PSF and MTF in optical system. Finally, we discuss and evaluate the consistency of the PSF (MTF) of the wavefront coding athermal system and the image restorability, which provides the basis and reference for the optimal design of the wavefront coding athermal system. The results show that the adaptability of single material infrared wavefront coding athermal system to axial temperature gradient can reach the upper limit of temperature fluctuation of 60°C, which is much higher than that of radial temperature gradient.

  18. Design of Radial Inflow Turbine for 30 kW Microturbine

    Directory of Open Access Journals (Sweden)

    Sangsawangmatum Thanate

    2017-01-01

    Full Text Available Microturbines are small gas turbines that have the capacity range of 25-300 kW. The main components of microturbine are compressor, turbine, combustor and recuperator. This research paper focuses on the design of radial inflow turbine that operates in 30 kW microturbine. In order to operate the 30 kW microturbine with the back work ratio of 0.5, the radial inflow turbine should be designed to produce power at 60 kW. With the help of theory of turbo-machinery and the analytical methods, the design parameters are derived. The design results are constructed in 3D geometry. The 3D fluid-geometry is validated by computational fluid dynamics (CFD simulation. The simulation results show the airflow path, the temperature distribution, the pressure distribution and Mach number. According to the simulation results, there is no flow blockage between vanes and no shock flow occurs in the designed turbine.

  19. To the calculation technique and interpretation of atom radial distribution curves in ternary alloy systems

    International Nuclear Information System (INIS)

    Dutchak, Ya.I.; Frenchko, V.S.; Voznyak, O.M.

    1975-01-01

    Certain models of the structure of three-component melts are considered: the ''quasi-eutectic'' one, the model of statistical distribution of atoms and the ''polystructural'' model. The analytical expressions are given for the area under the first maximum of the curve describing the radial distribution of atoms for certain versions of the ''polystructural'' model. On the example of In-Ga-Ga and Bi-Cd-Sn eutectic melts the possibility of estimating the nature of atomic ordering in three-component melts through checking the models under consideration has been demonstrated

  20. The Gaia-ESO Survey: the present-day radial metallicity distribution of the Galactic disc probed by pre-main-sequence clusters

    Science.gov (United States)

    Spina, L.; Randich, S.; Magrini, L.; Jeffries, R. D.; Friel, E. D.; Sacco, G. G.; Pancino, E.; Bonito, R.; Bravi, L.; Franciosini, E.; Klutsch, A.; Montes, D.; Gilmore, G.; Vallenari, A.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Koposov, S. E.; Korn, A. J.; Lanzafame, A. C.; Smiljanic, R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Donati, P.; Frasca, A.; Hourihane, A.; Jofré, P.; Lewis, J.; Lind, K.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

    2017-05-01

    Context. The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open star clusters allow us to derive both the radial metallicity distribution and its evolution over time. Aims: In this paper we perform the first investigation of the present-day radial metallicity distribution based on [Fe/H] determinations in late type members of pre-main-sequence clusters. Because of their youth, these clusters are therefore essential for tracing the current interstellar medium metallicity. Methods: We used the products of the Gaia-ESO Survey analysis of 12 young regions (age ages is not easily explained by the models. Our results reveal a complex interplay of several processes (e.g. star formation activity, initial mass function, supernova yields, gas flows) that controlled the recent evolution of the Milky Way. Based on observations made with the ESO/VLT, at Paranal Observatory, under program 188.B-3002 (The Gaia-ESO Public Spectroscopic Survey).Full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A70

  1. Experimental feasibility study of radial injection cooling of three-pad radial air foil bearings

    Science.gov (United States)

    Shrestha, Suman K.

    Air foil bearings use ambient air as a lubricant allowing environment-friendly operation. When they are designed, installed, and operated properly, air foil bearings are very cost effective and reliable solution to oil-free turbomachinery. Because air is used as a lubricant, there are no mechanical contacts between the rotor and bearings and when the rotor is lifted off the bearing, near frictionless quiet operation is possible. However, due to the high speed operation, thermal management is one of the very important design factors to consider. Most widely accepted practice of the cooling method is axial cooling, which uses cooling air passing through heat exchange channels formed underneath the bearing pad. Advantage is no hardware modification to implement the axial cooling because elastic foundation structure of foil bearing serves as a heat exchange channels. Disadvantage is axial temperature gradient on the journal shaft and bearing. This work presents the experimental feasibility study of alternative cooling method using radial injection of cooling air directly on the rotor shaft. The injection speeds, number of nozzles, location of nozzles, total air flow rate are important factors determining the effectiveness of the radial injection cooling method. Effectiveness of the radial injection cooling was compared with traditional axial cooling method. A previously constructed test rig was modified to accommodate a new motor with higher torque and radial injection cooling. The radial injection cooling utilizes the direct air injection to the inlet region of air film from three locations at 120° from one another with each location having three axially separated holes. In axial cooling, a certain axial pressure gradient is applied across the bearing to induce axial cooling air through bump foil channels. For the comparison of the two methods, the same amount of cooling air flow rate was used for both axial cooling and radial injection. Cooling air flow rate was

  2. Constraints on radial migration in spiral galaxies - II. Angular momentum distribution and preferential migration

    Science.gov (United States)

    Daniel, Kathryne J.; Wyse, Rosemary F. G.

    2018-05-01

    The orbital angular momentum of individual stars in galactic discs can be permanently changed through torques from transient spiral patterns. Interactions at the corotation resonance dominate these changes and have the further property of conserving orbital circularity. We derived in an earlier paper an analytic criterion that an unperturbed stellar orbit must satisfy in order for such an interaction to occur, i.e. for it to be in a trapped orbit around corotation. We here use this criterion in an investigation of how the efficiency of induced radial migration for a population of disc stars varies with the angular momentum distribution of that population. We frame our results in terms of the velocity dispersion of the population, this being an easier observable than is the angular momentum distribution. Specifically, we investigate how the fraction of stars in trapped orbits at corotation varies with the velocity dispersion of the population, for a system with an assumed flat rotation curve. Our analytic results agree with the finding from simulations that radial migration is less effective in populations with `hotter' kinematics. We further quantify the dependence of this trapped fraction on the strength of the spiral pattern, finding a higher trapped fraction for higher amplitude perturbations.

  3. Radial and azimuthal distribution of Io's oxygen neutral cloud observed by Hisaki/EXCEED

    Science.gov (United States)

    Koga, R.; Tsuchiya, F.; Kagitani, M.; Sakanoi, T.; Yoneda, M.; Yoshikawa, I.; Yoshioka, K.; Murakami, G.; Yamazaki, A.; Kimura, T.; Smith, H. T.

    2017-12-01

    We report the spatial distributions of oxygen neural cloud surrounding Jupiter's moon Io and along Io's orbit observed by the HISAKI satellite. Atomic oxygen and sulfur in Io's atmosphere escape from the exobase and move to corona ( 5.8 Io radii) mainly due to atmospheric sputtering. Io plasma torus is formed by ionization of these atoms by electron impact and charge exchange processes. It is essential to examine the dominant source of Io plasma torus, particularly in the vicinity of Io (5.8 Io radii; extended neutral clouds). The spatial distribution of oxygen and sulfur neutral clouds is important to understand the source. The extreme ultraviolet spectrometer called EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) installed on the Hisaki satellite observed Io plasma torus continuously in 2014-2015, and we carried out the monitoring of the distribution of atomic oxygen emission at 130.4 nm. The emission averaged over the distance range of 4.5-6.5 Jovian radii on the dawn and dusk sides strongly depends on the Io phase angle (IPA), and has a emission peak between IPA of 60-90 degrees on the dawn side, and between 240-270 degrees on the dusk side, respectively. It also shows the asymmetry with respect to Io's position: the intensity averaged for IPA 60-90 degrees (13.3 Rayleighs (R)) is 1.2 times greater than that for IPA 90-120 degrees (11.1 R) on the dawn side. The similar tendency is found on the dusk side. Weak atomic oxygen emission (4 R) uniformly distributes in every IPA. We also examined the radial distribution of the oxygen neutral cloud during the same period and found the emission peak near Io's orbit with decreasing the intensity toward 8.0 Jupiter radii. The results show the high density component of the oxygen neutral cloud is concentrated around Io and extends mainly toward leading side of Io. In addition, the low density neutrals uniformly exist along Io's orbit. Both components extend radially outward up to 8 Jovian radii with

  4. Structural changes of radial forging die surface during service under thermo-mechanical fatigue

    International Nuclear Information System (INIS)

    Nematzadeh, Fardin; Akbarpour, Mohammad Reza; Kokabi, Amir Hosein; Sadrnezhaad, Seyed Khatiboleslam

    2009-01-01

    Radial forging is one of the modern open die forging techniques and has a wide application in producing machine parts. During operation at high temperatures, severe temperature change associated with mechanical loads and the resultant wearing of the die surface lead to intense variation in strain on the die surface. Therefore, under this operating condition, thermo-mechanical fatigue (TMF) occurs on the surface of the radial forging die. TMF decreases the life of the die severely. In the present research, different layers were deposited on a 1.2714 steel die by SMAW and GTAW, with a weld wire of UDIMET 520. The microstructure of the radial forging die surface was investigated during welding and service using an optical microscope and scanning electron microscope. The results revealed that, after welding, the structure of the radial forging die surface includes the γ matrix with a homogeneous distribution of fine semi-spherical carbides. The weld structure consisted mostly of columnar dendrites with low grain boundaries. Also, microstructural investigation of the die surface during operation showed that the weld structure of the die surface has remained without any considerable change. Only dendrites were deformed and broken. Moreover, grain boundaries of the dendrites were revealed during service.

  5. Interactions between Radial Electric Field, Transport and Structure in Helical Plasmas

    International Nuclear Information System (INIS)

    Ida, Katsumi and others

    2006-01-01

    Control of the radial electric field is considered to be important in helical plasmas, because the radial electric field and its shear are expected to reduce neoclassical and anomalous transport, respectively. Particle and heat transport, that determines the radial structure of density and electron profiles, sensitive to the structure of radial electric field. On the other hand, the radial electric field itself is determined by the plasma parameters. In general, the sign of the radial electric field is determined by the plasma collisionality, while the magnitude of the radial electric field is determined by the temperature and/or density gradients. Therefore the structure of radial electric field and temperature and density are strongly coupled through the particle and heat transport and formation mechanism of radial electric field. Interactions between radial electric field, transport and structure in helical plasmas is discussed based on the experiments on Large Helical Device

  6. Radial dose distribution of 6.0 MeV/n α-particle in water

    International Nuclear Information System (INIS)

    Soga, F.; Sato, Y.; Hirabayashi, M.; Ohsawa, D.

    2003-01-01

    For the study of radiation biology and its application to radiotherapy, the double differential cross section of electron emission from water vapor induced by 6.0 MeV alpha particle beam is measured. The energy spectra of electrons ranging 7- 10000 eV are detected by the electrostatic analyzer and micro channel plate. The measurements are made at angles between 20 and 160 degrees. With use of this data set, the radial dose distribution in water is calculated by using KURBUC code. It is the Monte Carlo type code of the electron transport process, where the track of the electron is simulated through each individual interactions including elastic scattering, ionization cross section and total excitation cross section in case that electrons with certain energy are put in the liquid-density water. In order to understand the effect of radiation when the particle flux is injected in the human body like radiotherapy using accelerator beam, the dose distribution in the biological substances is essential as the first step to know the effect of irradiation. From the double differential cross sections obtained, the cumulative density functions are produced concerning both energy and angle. These functions are used for the initial randomly produced rays for 3 dimensional Monte Carlo track simulations. The results show that the track of electrons emitted and slowed down is most frequent in the perpendicular direction to the initial beam direction and most of the secondary electrons are stopped within the range of 100 nanometers. The characteristic of the obtained radial dose distribution is nearly 1/r 2 dependence with broad plateau region (penumbra) and gradual decreasing tail of penumbra extending more than a few micrometers which is much longer than the theoretical prediction

  7. Fluid-Thermal-Structural Coupled Analysis of a Radial Inflow Micro Gas Turbine Using Computational Fluid Dynamics and Computational Solid Mechanics

    Directory of Open Access Journals (Sweden)

    Yonghui Xie

    2014-01-01

    Full Text Available A three-dimensional fluid-thermal-structural coupled analysis for a radial inflow micro gas turbine is conducted. First, a fluid-thermal coupled analysis of the flow and temperature fields of the nozzle passage and the blade passage is performed by using computational fluid dynamics (CFD. The flow and heat transfer characteristics of different sections are analyzed in detail. The thermal load and the aerodynamic load are then obtained from the temperature field and the pressure distribution. The stress distributions of the blade are finally studied by using computational solid mechanics (CSM considering three cases of loads: thermal load, aerodynamics load combined with centrifugal load, and all the three types of loads. The detailed parameters of the flow, temperature, and the stress are obtained and analyzed. The numerical results obtained provide a useful knowledge base for further exploration of radial gas turbine design.

  8. Validation of the TUBRNP model with the radial distribution of plutonium in MOX fuel measured by SIMS and EPMA

    Energy Technology Data Exchange (ETDEWEB)

    O` Carroll, C; Laar, J Van De; Walker, C T [CEC Joint Research Centre, Karlsruhe (Germany)

    1997-08-01

    The new model TUBRNP (TRANSURANUS burnup) predicts the radial power density distribution as a function of burnup (and hence the radial burnup profile as a function of time) together with the radial profile of plutonium. Comparisons between measurements and the prediction of the TUBRNP model have been made for UO{sub 2} LWR fuels: they were found to be in excellent agreement and it is seen that TUBRNP is a marked improved on previous models. A powerful techniques for the characterization of irradiation fuel is Electron Probe Microanalysis (EPMA). Uranium, plutonium and fission product distributions can be analysed quantitatively. A complement, providing isotopic information with a lateral resolution comparable to EPMA, is secondary ion mass spectrometry (SIMS). Recently, the technique has been successfully applied for the measurement of the radial distribution of plutonium isotopes in irradiated nuclear fuel pins. The extension of the TUBRNP model to mixed oxide fuels seems to be the natural step to take. In MOX fuels the picture is greatly complicated by the presence of the (U, Pu)O{sub 2} agglomerates. The rim effect referred to above may be masked by the high concentrations of plutonium in the bulk of the fuel. A detailed investigation of a number of MOX fuel samples has been made using the TUBRNP model. Results are presented for a range of fuels with different enrichment and burnup. Through its participation in the PRIMO and DOMO programmes, PSI in conjunction with the Institute for Transuranium Elements had the opportunity to validate the new theoretical model TUBRNP. The authors with therefore to express their thanks to the organizers and to the numerous European and Japanese organizations which have supported these two international programmes on MOX fuel behavior. 7 refs, 9 figs, 3 tabs.

  9. Formulation and Analysis of an Approximate Expression for Voltage Sensitivity in Radial DC Distribution Systems

    Directory of Open Access Journals (Sweden)

    Ho-Yong Jeong

    2015-08-01

    Full Text Available Voltage is an important variable that reflects system conditions in DC distribution systems and affects many characteristics of a system. In a DC distribution system, there is a close relationship between the real power and the voltage magnitude, and this is one of major differences from the characteristics of AC distribution systems. One such relationship is expressed as the voltage sensitivity, and an understanding of voltage sensitivity is very useful to describe DC distribution systems. In this paper, a formulation for a novel approximate expression for the voltage sensitivity in a radial DC distribution system is presented. The approximate expression is derived from the power flow equation with some additional assumptions. The results of approximate expression is compared with an exact calculation, and relations between the voltage sensitivity and electrical quantities are analyzed analytically using both the exact form and the approximate voltage sensitivity equation.

  10. Radial distributions of surface mass density and mass-to-luminosity ratio in spiral galaxies

    Science.gov (United States)

    Sofue, Yoshiaki

    2018-03-01

    We present radial profiles of the surface mass density (SMD) in spiral galaxies directly calculated using rotation curves of two approximations of flat-disk (SMD-F) and spherical mass distribution (SMD-S). The SMDs are combined with surface brightness using photometric data to derive radial variations of the mass-to-luminosity ratio (ML). It is found that the ML generally has a central peak or a plateau, and decreases to a local minimum at R ˜ 0.1-0.2 h, where R is the radius and h is the scale radius of optical disk. The ML, then, increases rapidly until ˜0.5 h, and is followed by gradual rise till ˜2 h, remaining at around ˜2 [M_{⊙} L^{-1}_{⊙}] in the w1 band (infrared λ3.4 μm) and ˜ 10 [M_⊙ L_⊙ ^{-1}] in the r band (λ6200-7500 Å). Beyond this radius, the ML increases steeply with approaching the observed edges at R ˜ 5 h, attaining to as high values as ˜20 in w1 and ˜ 10^2 [M_⊙ L_⊙ ^{-1}] in the r band, which are indicative of dominant dark matter. The general properties of the ML distributions will be useful for constraining cosmological formation models of spiral galaxies.

  11. Influence on rewetting temperature and wetting delay during rewetting rod bundle by various radial jet models

    Energy Technology Data Exchange (ETDEWEB)

    Debbarma, Ajoy; Pandey, Krishna Murari [National Institute of Technology, Assam (India). Dept. of Mechanical Engineering

    2016-03-15

    Numerical investigation of the rewetting of single sector fuel assembly of Advanced Heavy Water Reactor (AHWR) has been carried out to exhibit the effect of coolant jet diameters (2, 3 and 4 mm) and jet directions (Model: M, X and X2). The rewetting phenomena with various jet models are compared on the basis of rewetting temperature and wetting delay. Temperature-time curve have been evaluated from rods surfaces at different circumference, radial and axial locations of rod bundle. The cooling curve indicated the presence of vapor in respected location, where it prevents the contact between the firm and fluid phases. The peak wall temperature represents as rewetting temperature. The time period observed between initial to rewetting temperature point is wetting delay. It was noted that as improved in various jet models, rewetting temperature and wetting delay reduced, which referred the coolant stipulation in the rod bundle dominant vapor formation.

  12. Influence on rewetting temperature and wetting delay during rewetting rod bundle by various radial jet models

    International Nuclear Information System (INIS)

    Debbarma, Ajoy; Pandey, Krishna Murari

    2016-01-01

    Numerical investigation of the rewetting of single sector fuel assembly of Advanced Heavy Water Reactor (AHWR) has been carried out to exhibit the effect of coolant jet diameters (2, 3 and 4 mm) and jet directions (Model: M, X and X2). The rewetting phenomena with various jet models are compared on the basis of rewetting temperature and wetting delay. Temperature-time curve have been evaluated from rods surfaces at different circumference, radial and axial locations of rod bundle. The cooling curve indicated the presence of vapor in respected location, where it prevents the contact between the firm and fluid phases. The peak wall temperature represents as rewetting temperature. The time period observed between initial to rewetting temperature point is wetting delay. It was noted that as improved in various jet models, rewetting temperature and wetting delay reduced, which referred the coolant stipulation in the rod bundle dominant vapor formation.

  13. Radial profiles of temperature and viscosity in the Earth's mantle inferred from the geoid and lateral seismic structure

    NARCIS (Netherlands)

    Cadek, O.; Berg, A.P. van den

    1998-01-01

    In the framework of dynamical modelling of the geoid, we have estimated basic features of the radial profile of temperature in the mantle. The applied parameterization of the geotherm directly characterizes thermal boundary layers and values of the thermal gradient in the upper and lower mantle.

  14. Stirling Engine With Radial Flow Heat Exchangers

    Science.gov (United States)

    Vitale, N.; Yarr, George

    1993-01-01

    Conflict between thermodynamical and structural requirements resolved. In Stirling engine of new cylindrical configuration, regenerator and acceptor and rejector heat exchangers channel flow of working gas in radial direction. Isotherms in regenerator ideally concentric cylinders, and gradient of temperature across regenerator radial rather than axial. Acceptor and rejector heat exchangers located radially inward and outward of regenerator, respectively. Enables substantial increase in power of engine without corresponding increase in diameter of pressure vessel.

  15. Phase diagrams and radial distribution of the electric field components of coaxial discharges with outer dielectric tube at different wave modes

    International Nuclear Information System (INIS)

    Neichev, Z; Benova, E; Gamero, A; Sola, A

    2007-01-01

    The purpose of this work is to investigate phase diagrams and electric field radial distribution of coaxial discharges, sustained by a traveling electromagnetic wave, assuming finite and infinite thickness of the discharge chamber in the model. The calculations are made for azimuthally symmetric and dipolar wave modes. The phase diagrams and the radial profiles of the electric field at various thicknesses of the outer dielectric tube of the chamber and different discharge conditions are obtained. For the purpose of low pressure coaxial plasma modelling, radial profiles of the electric field at different discharge conditions have been investigated experimentally and compared with the theoretical results

  16. Development of micro-scale axial and radial turbines for low-temperature heat source driven organic Rankine cycle

    International Nuclear Information System (INIS)

    Al Jubori, Ayad; Daabo, Ahmed; Al-Dadah, Raya K.; Mahmoud, Saad; Ennil, Ali Bahr

    2016-01-01

    Highlights: • One and three-dimensional analysis with real gas properties are integrated. • Micro axial and radial-inflow turbines configurations are investigated. • Five organic working fluids are considered. • The maximum total isentropic efficiency of radial-inflow turbine 83.85%. • The maximum ORC thermal efficiency based on radial-inflow turbine is 10.60%. - Abstract: Most studies on the organic Rankine cycle (ORC) focused on parametric studies and selection working fluids to maximize the performance of organic Rankine cycle but without attention for turbine design features which are crucial to achieving them. The rotational speed, expansion ratio, mass flow rate and turbine size have markedly effect on turbine performance. For this purpose organic Rankine cycle modeling, mean-line design and three-dimensional computational fluid dynamics analysis were integrated for both micro axial and radial-inflow turbines with five organic fluids (R141b, R1234yf, R245fa, n-butane and n-pentane) for realistic low-temperature heat source <100 °C like solar and geothermal energy. Three-dimensional simulation is performed using ANSYS"R"1"7-CFX where three-dimensional Reynolds-averaged Navier-Stokes equations are solved with k-omega shear stress transport turbulence model. Both configurations of turbines are designed at wide range of mass flow rate (0.1–0.5) kg/s for each working fluid. The results showed that n-pentane has the highest performance at all design conditions where the maximum total-to-total efficiency and power output of radial-inflow turbine are 83.85% and 8.893 kW respectively. The performance of the axial turbine was 83.48% total-to-total efficiency and 8.507 kW power output. The maximum overall size of axial turbine was 64.685 mm compared with 70.97 mm for radial-inflow turbine. R245fa has the lowest overall size for all cases. The organic Rankine cycle thermal efficiency was about 10.60% with radial-inflow turbine and 10.14% with axial turbine

  17. A radial distribution function-based open boundary force model for multi-centered molecules

    KAUST Repository

    Neumann, Philipp

    2014-06-01

    We derive an expression for radial distribution function (RDF)-based open boundary forcing for molecules with multiple interaction sites. Due to the high-dimensionality of the molecule configuration space and missing rotational invariance, a computationally cheap, 1D approximation of the arising integral expressions as in the single-centered case is not possible anymore. We propose a simple, yet accurate model invoking standard molecule- and site-based RDFs to approximate the respective integral equation. The new open boundary force model is validated for ethane in different scenarios and shows very good agreement with data from periodic simulations. © World Scientific Publishing Company.

  18. Kinetic transport properties of a bumpy torus with finite radial ambipolar field

    International Nuclear Information System (INIS)

    Spong, D.A.; Harris, E.G.; Hedrick, C.L.

    1978-04-01

    Bumpy torus neoclassical transport coefficients have been calculted including finite values of the radial ambipolar field. These are obtained by solving a bounce-averaged drift kinetic equation in a local approximation for perturbations in the distribution function (away from a stationary Maxwellian) caused by toroidicity and radial gradients in plasma density, temperature, and potential. Particle and energy fluxes along with the associated transport coefficients are then calculated by taking appropriate moments of the distribution function. Particle orbits are treated by breaking them up into a vertical drift component (due to toroidicity) and a theta precessional drift (as a result of Vector E x Vector B and drifts due to the bumpy toroidal field). The kinetic equation has been solved using both a functional expansion method and finite difference techniques [Alternating-Direction-Implicit (ADI)]. The resulting transport coefficients exhibit a strong dependence on the ambipolar electric field and plasma collisionality. In the large electric field limit, our results are in close agreement with the earlier work of Kovrizhnykh

  19. Constrained multi-objective optimization of radial expanders in organic Rankine cycles by firefly algorithm

    International Nuclear Information System (INIS)

    Bahadormanesh, Nikrouz; Rahat, Shayan; Yarali, Milad

    2017-01-01

    Highlights: • A multi-objective optimization for radial expander in Organic Rankine Cycles is implemented. • By using firefly algorithm, Pareto front based on the size of turbine and thermal efficiency is produced. • Tension and vibration constrains have a significant effect on optimum design points. - Abstract: Organic Rankine Cycles are viable energy conversion systems in sustainable energy systems due to their compatibility with low-temperature heat sources. In the present study, one dimensional model of radial expanders in conjunction with a thermodynamic model of organic Rankine cycles is prepared. After verification, by defining thermal efficiency of the cycle and size parameter of a radial turbine as the objective functions, a multi-objective optimization was conducted regarding tension and vibration constraints for 4 different organic working fluids (R22, R245fa, R236fa and N-Pentane). In addition to mass flow rate, evaporator temperature, maximum pressure of cycle and turbo-machinery design parameters are selected as the decision variables. Regarding Pareto fronts, by a little increase in size of radial expanders, it is feasible to reach high efficiency. Moreover, by assessing the distribution of decision variables, the variables that play a major role in trending between the objective functions are found. Effects of mechanical and vibration constrains on optimum decision variables are investigated. The results of optimization can be considered as an initial values for design of radial turbines for Organic Rankine Cycles.

  20. Fast gas heating and radial distribution of active species in nanosecond capillary discharge in pure nitrogen and N2:O2 mixtures

    Science.gov (United States)

    Lepikhin, N. D.; Popov, N. A.; Starikovskaia, S. M.

    2018-05-01

    Fast gas heating is studied experimentally and numerically using pulsed nanosecond capillary discharge in pure nitrogen and N2:O2 mixtures under the conditions of high specific deposited energy (up to 1 eV/molecule) and high reduced electric fields (100–300 Td). Deposited energy, electric field and gas temperature are measured as functions of time. The radial distribution of active species is analyzed experimentally. The roles of processes involving {{{N}}}2({{B}}) ={{{N}}}2({{{B}}}3{{{\\Pi }}}{{g}},{{{W}}}3{{{Δ }}}{{u}},{{B}}{{\\prime} }3{{{Σ }}}{{u}}-), {{{N}}}2({{{A}}}3{{{Σ }}}{{u}}+) and N(2D) excited nitrogen species leading to heat release are analyzed using numerical modeling in the framework of 1D axial approximation.

  1. Effects of Acids, Bases, and Heteroatoms on Proximal Radial Distribution Functions for Proteins.

    Science.gov (United States)

    Nguyen, Bao Linh; Pettitt, B Montgomery

    2015-04-14

    The proximal distribution of water around proteins is a convenient method of quantifying solvation. We consider the effect of charged and sulfur-containing amino acid side-chain atoms on the proximal radial distribution function (pRDF) of water molecules around proteins using side-chain analogs. The pRDF represents the relative probability of finding any solvent molecule at a distance from the closest or surface perpendicular protein atom. We consider the near-neighbor distribution. Previously, pRDFs were shown to be universal descriptors of the water molecules around C, N, and O atom types across hundreds of globular proteins. Using averaged pRDFs, a solvent density around any globular protein can be reconstructed with controllable relative error. Solvent reconstruction using the additional information from charged amino acid side-chain atom types from both small models and protein averages reveals the effects of surface charge distribution on solvent density and improves the reconstruction errors relative to simulation. Solvent density reconstructions from the small-molecule models are as effective and less computationally demanding than reconstructions from full macromolecular models in reproducing preferred hydration sites and solvent density fluctuations.

  2. Analysis of the radial distribution curves of partially ordered condensed carbon films

    International Nuclear Information System (INIS)

    Palatnik, L.S.; Derevyanchenko, A.S.; Nechitajlo, A.A.; Stetsenko, A.N.; Gorbenko, N.I.

    1977-01-01

    The Fourier analysis of the electron scattering curves has been carried out to determine the short-range order structure of carbon condensates. The intensity curves for carbon films condensed in a approximately 10 -6 Torr vacuum upon a substrate heated up to 600 deg C were obtained by diffraction techniques with filtration of the inelastic scattered electron background. The radial distribution curve errors were analyzed and quantified with the aid of a computer to determine the short-range order of the condensed carbon. It has been shown that carbon films consist of regions measuring approximately 20 A formed by parallelly packed graphite nets with azimuthal orientation different from that in ideal graphite crystals

  3. Temperature distributions in 136 superficial radiothermotherapies

    International Nuclear Information System (INIS)

    Willich, N.; Duve, S.; Pfluger, T.; Bachmeier, K.

    1992-01-01

    Temperature distributions from 136 superficial radiothermotherapies in patients were analysed and three-dimensionally reconstructed. The calculation of mean values and standard deviations of the temperature measuring probes considering water bolus temperature, master probe temperature, site of the probes relatively to different applicator positions and site of the probes in the heated tissues yielded satisfactory temperature distributions for chest wall treatment in contrast to other regions of the body. Radiothermotherapy was statistically not superior to radiotherapy alone with respect to local tumor control. (authors)

  4. Radial expansion and multifragmentation

    International Nuclear Information System (INIS)

    Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Kerambrun, A.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Meslin, C.; Nakagawa, T.; Patry, J.P.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Yuasa-Nakagawa, K.; Wieloch, A.

    1998-01-01

    The light systems 36 Ar + 27 Al and 64 Zn + nat Ti were measured at several bombarding energies between ∼ 35 and 95 MeV/nucleon. It was found that the predominant part of the cross section is due to binary collisions. In this paper the focus is placed on the properties of the quasi-projectile nuclei. In the central collisions the excitation energies of the quasi-projectile reach values exceeding largely 10 MeV/nucleon. The slope of the high energy part of the distribution can give only an upper limit of the apparent temperature (the average temperature along the decay chain). The highly excited quasi-projectile may get rapidly fragmented rather than sequentially. The heavy fragments are excited and can emit light particles (n, p, d, t, 3 He, α,...) what perturbs additionally the spectrum of these particles. Concerning the expansion energy, one can determine the average kinetic energies of the product (in the quasi-projectile-framework) and compare with simulation values. To fit the experimental data an additional radial expansion energy is to be considered. The average expansion energy depends slightly on the impact parameter but it increases with E * / A, ranging from 0.4 to 1,2 MeV/nucleon for an excitation energy increasing from 7 to 10.5 MeV/nucleon. This collective radial energy seems to be independent of the fragment mass, what is possibly valid for the case of larger quasi-projectile masses. The origin of the expansion is to be determined. It may be due to a compression in the interaction zone at the initial stage of the collision, which propagates in the quasi-projectile and quasi-target, or else, may be due, simply, to the increase of thermal energy leading to a rapid fragment emission. The sequential de-excitation calculation overestimates light particle emission and consequently heavy residues, particularly, at higher excitation energies. This disagreement indicates that a sequential process can not account for the di-excitation of very hot nuclei

  5. On the radial distribution of white dwarfs in the Galactic globular cluster omega Cen

    Science.gov (United States)

    Calamida, A.; Corsi, C. E.; Bono, G.; Stetson, P. B.; Prada Moroni, P. G.; Degl'Innocenti, S.; Ferraro, I.; Iannicola, G.; Koester, D.; Pulone, L.; Monelli, M.; Amico, P.; Buonanno, R.; Freyhammer, L. M.; Marchetti, E.; Nonino, M.; Romaniello, M.

    We present deep and accurate photometry (F435W, F625W, F658N) of the Galactic Globular Cluster omega Cen collected with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST). We identified ≈ 6,500 white dwarf (WD) candidates and compared their radial distribution with that of Main Sequence (MS) stars. We found a mild evidence that young WDs ( 0.1 ≲ t ≲ 0.6 Gyr) are less centrally concentrated when compared to MS stars in the magnitude range 25 < F435W < 26.5.

  6. [Comparison of chemical quality characteristics between radial striations and non-radial striations in tuberous root of Rehmannia glutinosa].

    Science.gov (United States)

    Xie, Cai-Xia; Zhang, Miao; Li, Ya-Jing; Geng, Xiao-Tong; Wang, Feng-Qing; Zhang, Zhong-Yi

    2017-11-01

    An HPLC method was established to determine the contents of catalpol, acteoside, rehmaionoside A, rehmaionoside D, leonuride in three part of Rehmanni glutinosa in Beijing No.1 variety R. glutinosa during the growth period, This method, in combination with its HPLC fingerprint was used to evaluate its overall quality characteristics.The results showed that:① the content of main components of R. glutinosa varied in different growth stages ;② there was a great difference of the content of main components between theradial striations and the non-radial striations; ③ the two sections almost have the same content distribution of catalpol, acteoside and rehmaionoside D; ④the content of rehmaionoside A in non-radial striations was higher than that in radial striations,while the content of leonuride in radial striations was higher than that in non-radial striations.; ⑤the HPLC fingerprint of radial striations, non-radial striations and whole root tuber were basically identical, except for the big difference in the content of chemical components. The result of clustering displayed that the radial striations, non-radial striations, and whole root were divided into two groups. In conclusion, there was a significant difference in the quality characteristics of radial striations and non-radial striations of R. glutinosa. This research provides a reference for quality evaluation and geoherbalism of R. glutinosa. Copyright© by the Chinese Pharmaceutical Association.

  7. Power system reconfiguration in a radial distribution network for reducing losses and to improve voltage profile using modified plant growth simulation algorithm with Distributed Generation (DG

    Directory of Open Access Journals (Sweden)

    R. Rajaram

    2015-11-01

    Full Text Available Network reconfiguration which is constrained non linear optimization problem has been solved for loss minimization, load balancing, etc. for last two decades using various heuristic search evolutionary algorithms like binary particle swarm optimization, neuro-fuzzy techniques, etc. The contribution of this paper lies in considering distributed generation which are smaller power sources like solar photovoltaic cells or wind turbines connected in the customer roof top. This new connection in the radial network has made unidirectional current flow to become bidirectional there by increasing the efficiency but sometimes reducing stability of the system. Modified plant growth simulation algorithm has been applied here successfully to minimize real power loss because it does not require barrier factors or cross over rates because the objectives and constraints are dealt separately. The main advantage of this algorithm is continuous guiding search along with changing objective function because power from distributed generation is continuously varying so this can be applied for real time applications with required modifications. This algorithm here is tested for a standard 33 bus radial distribution system for loss minimization and test results here shows that this algorithm is efficient and suitable for real time applications.

  8. A Raikov-Type Theorem for Radial Poisson Distributions: A Proof of Kingman's Conjecture

    OpenAIRE

    Van Nguyen, Thu

    2011-01-01

    In the present paper we prove the following conjecture in Kingman, J.F.C., Random walks with spherical symmetry, Acta Math.,109, (1963), 11-53. concerning a famous Raikov's theorem of decomposition of Poisson random variables: "If a radial sum of two independent random variables X and Y is radial Poisson, then each of them must be radial Poisson."

  9. Characterization of Radial Curved Fin Heat Sink under Natural and Forced Convection

    Science.gov (United States)

    Khadke, Rishikesh; Bhole, Kiran

    2018-02-01

    Heat exchangers are important structures widely used in power plants, food industries, refrigeration, and air conditioners and now widely used in computing systems. Finned type of heat sink is widely used in computing systems. The main aim of the design of the heat sink is to maintain the optimum temperature level. To achieve this goal so many geometrical configurations are implemented. This paper presents a characterization of radially curved fin heat sink under natural and forced convection. Forced convection is studied for the optimization of temperature for better efficiency. The different alternatives in geometry are considered in characterization are heat intensity, the height of the fin and speed of the fan. By recognizing these alternatives the heat sink is characterized by the heat flux usually generated in high-end PCs. The temperature drop characteristics across height and radial direction are presented for the constant heat input and air flow in the heat sink. The effect of dimensionless elevation height (0 ≤ Z* ≤ 1) and Elenbaas Number (0.4 ≤ El ≤ 2.8) of the heat sink were investigated for study of the Nusselt number. Based on experimental characterization, process plan has been developed for the selection of the similar heat sinks for desired output (heat dissipation and temperature distribution).

  10. Derivation of the radial profile of ion temperature from the measured energy spectra of charge-exchanged neutrals

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K; Hiraki, N; Toi, K; Itoh, S

    1980-01-01

    In the TRIAM-1 tokamak the energy spectra of charge-exchanged neutrals are observed by scanning the neutral energy analyzer vertically. The measured ion temperature obtained from the only energy spectrum observed in the peripheral region is much higher than that predicted by the neoclassical transport theory because of reflection (backscattering) of neutrals at the wall. The actual ion temperature profile is derived from all observed energy spectra by the numerical code in which a wall-reflection effect of neutrals and an impermeability of plasma are taken into account. The reflection coefficient is adjusted so that the calculated ion temperature profile should be the best fit for the ion temperatures measured by the Doppler broadening of the visible lines He II 4686 A and H-alpha at the relevant radial positions.

  11. Distributed temperature sensor testing in liquid sodium

    Energy Technology Data Exchange (ETDEWEB)

    Gerardi, Craig, E-mail: cgerardi@anl.gov; Bremer, Nathan; Lisowski, Darius; Lomperski, Stephen

    2017-02-15

    Highlights: • Distributed temperature sensors measured high-resolution liquid-sodium temperatures. • DTSs worked well up to 400 °C. • A single DTS simultaneously detected sodium level and temperature. - Abstract: Rayleigh-backscatter-based distributed fiber optic sensors were immersed in sodium to obtain high-resolution liquid-sodium temperature measurements. Distributed temperature sensors (DTSs) functioned well up to 400 °C in a liquid sodium environment. The DTSs measured sodium column temperature and the temperature of a complex geometrical pattern that leveraged the flexibility of fiber optics. A single Ø 360 μm OD sensor registered dozens of temperatures along a length of over one meter at 100 Hz. We also demonstrated the capability to use a single DTS to simultaneously detect thermal interfaces (e.g. sodium level) and measure temperature.

  12. Energies and radial distributions of Bs mesons - the effect of hypercubic blocking

    Science.gov (United States)

    Koponen, Jonna

    2006-12-01

    This is a follow-up to our earlier work for the energies and the charge (vector) and matter (scalar) distributions for S-wave states in a heavy-light meson, where the heavy quark is static and the light quark has a mass about that of the strange quark. We study the radial distributions of higher angular momentum states, namely P- and D-wave states, using a "fuzzy" static quark. A new improvement is the use of hypercubic blocking in the time direction, which effectively constrains the heavy quark to move within a 2a hypercube (a is the lattice spacing). The calculation is carried out with dynamical fermions on a 163 × 32 lattice with a ≈ 0.10 fm generated using the non-perturbatively improved clover action. The configurations were gener- ated by the UKQCD Collaboration using lattice action parameters β = 5.2, c SW = 2.0171 and κ = 0.1350. In nature the closest equivalent of this heavy-light system is the Bs meson. Attempts are now being made to understand these results in terms of the Dirac equation.

  13. Radial power distribution shaping within a PWR fuel assembly utilizing asymmetrically loaded gadolinia-bearing fuel pins

    International Nuclear Information System (INIS)

    Stone, I.Z.

    1992-01-01

    As in-core fuel management designs evolve to meet the demands of increasing energy output, more innovative methods are developed to maintain power peaking within acceptable thermal margin limits. In-core fuel management staff must utilize various loading pattern strategies such as cross-core movement of fuel assemblies, multibatch enrichment schemes, and burnable absorbers as the primary means of controlling the radial power distribution. The utilization of fresh asymmetrically loaded gadolinia-bearing assemblies as a fuel management tool provides an additional means of controlling the radial power distribution. At Siemens Nuclear Power Corporation (SNP), fresh fuel assemblies fabricated with asymmetrically loaded gadolinia-bearing fuel rods have been used successfully for several cycles of reactor operation. Asymmetric assemblies are neutronically modeled using the same tools and models that SNP uses to model symmetrically loaded gadolinia-bearing fuel assemblies. The CASMO-2E code is used to produce the homogenized macroscopic assembly cross sections for the nodal core simulator. Optimum fuel pin locations within the asymmetrical assembly are determined using the pin-by-pin PDQ7 assembly core model for each new assembly design. The optimum pin location is determined by the rod loading that minimizes the peak-to-average pin power

  14. Thermal performance of a porus radial fin with natural convection and radiative heat losses

    Directory of Open Access Journals (Sweden)

    Darvishi M.T.

    2015-01-01

    Full Text Available An analytic (series solution is developed to describe the thermal performance of a porous radial fin with natural convection in the fluid saturating the fin and radiation heat loss from the top and bottom surfaces of the fin. The HAM results for the temperature distribution and base heat flux are compared with the direct numerical results and found to be very accurate.

  15. A prediction model for the effective thermal conductivity of nanofluids considering agglomeration and the radial distribution function of nanoparticles

    Science.gov (United States)

    Zheng, Z. M.; Wang, B.

    2018-06-01

    Conventional heat transfer fluids usually have low thermal conductivity, limiting their efficiency in many applications. Many experiments have shown that adding nanosize solid particles to conventional fluids can greatly enhance their thermal conductivity. To explain this anomalous phenomenon, many theoretical investigations have been conducted in recent years. Some of this research has indicated that the particle agglomeration effect that commonly occurs in nanofluids should play an important role in such enhancement of the thermal conductivity, while some have shown that the enhancement of the effective thermal conductivity might be accounted for by the structure of nanofluids, which can be described using the radial distribution function of particles. However, theoretical predictions from these studies are not in very good agreement with experimental results. This paper proposes a prediction model for the effective thermal conductivity of nanofluids, considering both the agglomeration effect and the radial distribution function of nanoparticles. The resulting theoretical predictions for several sets of nanofluids are highly consistent with experimental data.

  16. An axially averaged-radial transport model of tokamak edge plasmas

    International Nuclear Information System (INIS)

    Prinja, A.K.; Conn, R.W.

    1984-01-01

    A two-zone axially averaged-radial transport model for edge plasmas is described that incorporates parallel electron and ion conduction, localized recycling, parallel electron pressure gradient effects and sheath losses. Results for high recycling show that the radial electron temperature profile is determined by parallel electron conduction over short radial distances (proportional 3 cm). At larger radius where Tsub(e) has fallen appreciably, convective transport becomes equally important. The downstream density and ion temperature profiles are very flat over the region where electron conduction dominates. This is seen to result from a sharply decaying velocity profile that follows the radial electron temperature. A one-dimensional analytical recycling model shows that at high neutral pumping rates, the plasma density at the plate, nsub(ia), scales linearly with the unperturbed background density, nsub(io). When ionization dominates nsub(ia)/nsub(io) proportional exp(nsub(io)) while in the intermediate regime nsub(ia)/nsub(io) proportional exp(proportional nsub(io)). Such behavior is qualitatively in accord with experimental observations. (orig.)

  17. Temperature distributions of a conductively heated filament

    International Nuclear Information System (INIS)

    Tamura, Koji; Ohba, Hironori; Shibata, Takemasa

    1999-07-01

    Temperature distributions of a heated filament were measured. A W-Re(5%) filament (0.25 mm in diameter, 24.7 mm in length) was conductively heated by currents between 5A and 7A with a DC power supply, and the surface of the filament was imaged with a charge coupled device (CCD) camera through a monochromatic filter. The spectral radiation intensity at the filament center region was almost uniform. Since the temperature distribution was also uniform and the energy loss by thermal conduction was negligible, temperature in this region was determined from the energy balance between applied power and radiation loss. Temperature distribution of the filament was determined based on the Planck's law of radiation from the spectral radiation intensity ratio of the filament surface using obtained temperature as a reference. It was found that temperature distribution of a filament was easily measured by this method. (author)

  18. Derivation of the radial profile of ion temperature from the 'measured' energy spectra of charge-exchanged neutrals

    International Nuclear Information System (INIS)

    Nakamura, Kazuo; Hiraki, Naoji; Toi, Kazuo; Itoh, Satoshi

    1980-01-01

    In the TRIAM-1 tokamak the energy spectra of charge-exchanged neutrals are observed by scanning the neutral energy analyzer vertically. The ''measured'' ion temperature obtained from only energy spectrum observed in the peripheral region is much higher than that predicted by the neoclassical transport theory because of reflection (backscattering) of neutrals at the wall. The ''actual'' ion temperature profile is derived from all observed energy spectra by using the numerical code in which a wall-reflection effect of neutrals and an impermeability of plasma are taken into account. In this numerical analysis, the reflection coefficient is adjusted so that the above calculated ion temperature profile should be best fit for the ion temperatures measured by the Doppler broadening of the visible lines HeII 4686 A and H sub(α) at the relevant radial positions. (author)

  19. Derivation of the radial profile of ion temperature from the 'measured' energy spectra of charge-exchanged neutrals

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K; Hiraki, N; Toi, K; Itoh, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1980-07-01

    In the TRIAM-1 tokamak the energy spectra of charge-exchanged neutrals are observed by scanning the neutral energy analyzer vertically. The ''measured'' ion temperature obtained from only energy spectrum observed in the peripheral region is much higher than that predicted by the neoclassical transport theory because of reflection (backscattering) of neutrals at the wall. The ''actual'' ion temperature profile is derived from all observed energy spectra by using the numerical code in which a wall-reflection effect of neutrals and an impermeability of plasma are taken into account. In this numerical analysis, the reflection coefficient is adjusted so that the above calculated ion temperature profile should be best fit for the ion temperatures measured by the Doppler broadening of the visible lines HeII 4686 A and H sub(..cap alpha..) at the relevant radial positions.

  20. QUENCHING DEPENDS ON MORPHOLOGIES: IMPLICATIONS FROM THE ULTRAVIOLET-OPTICAL RADIAL COLOR DISTRIBUTIONS IN GREEN VALLEY GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Zhizheng; Lin, Weipeng [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Science, 80 Nandan Road, Shanghai 200030 (China); Li, Jinrong; Kong, Xu [Center of Astrophysics, University of Science and Technology of China, Jinzhai Road 96, Hefei 230026 (China); Wang, Jing, E-mail: panzz@shao.ac.cn, E-mail: linwp@shao.ac.cn [CSIRO Astronomy and Space Science, Australia Telescope National Facility, PO Box 76, Epping, NSW 1710 (Australia)

    2014-09-01

    In this Letter, we analyze the radial ultraviolet-optical color distributions in a sample of low redshift green valley galaxies, with the Galaxy Evolution Explorer (GALEX)+Sloan Digital Sky Survey (SDSS) images, to investigate how the residual recent star formation is distributed in these galaxies. We find that the dust-corrected u – r colors of early-type galaxies (ETGs) are flat out to R {sub 90}, while the colors monotonously turn blue when r > 0.5 R {sub 50} for late-type galaxies (LTGs). More than half of the ETGs are blue-cored and have remarkable positive NUV – r color gradients, suggesting that their star formations are centrally concentrated. The rest have flat color distributions out to R {sub 90}. The centrally concentrated star formation activity in a large portion of ETGs is confirmed by the SDSS spectroscopy, showing that ∼50% of the ETGs have EW(Hα) >6.0 Å. Of the LTGs, 95% show uniform radial color profiles, which can be interpreted as a red bulge plus an extended blue disk. The links between the two kinds of ETGs, e.g., those objects having remarkable ''blue-cores'' and those having flat color gradients, are less known and require future investigations. It is suggested that the LTGs follow a general model by which quenching first occurs in the core regions, and then finally extend to the rest of the galaxy. Our results can be re-examined and have important implications for the IFU surveys, such as MaNGA and SAMI.

  1. QUENCHING DEPENDS ON MORPHOLOGIES: IMPLICATIONS FROM THE ULTRAVIOLET-OPTICAL RADIAL COLOR DISTRIBUTIONS IN GREEN VALLEY GALAXIES

    International Nuclear Information System (INIS)

    Pan, Zhizheng; Lin, Weipeng; Li, Jinrong; Kong, Xu; Wang, Jing

    2014-01-01

    In this Letter, we analyze the radial ultraviolet-optical color distributions in a sample of low redshift green valley galaxies, with the Galaxy Evolution Explorer (GALEX)+Sloan Digital Sky Survey (SDSS) images, to investigate how the residual recent star formation is distributed in these galaxies. We find that the dust-corrected u – r colors of early-type galaxies (ETGs) are flat out to R 90 , while the colors monotonously turn blue when r > 0.5 R 50 for late-type galaxies (LTGs). More than half of the ETGs are blue-cored and have remarkable positive NUV – r color gradients, suggesting that their star formations are centrally concentrated. The rest have flat color distributions out to R 90 . The centrally concentrated star formation activity in a large portion of ETGs is confirmed by the SDSS spectroscopy, showing that ∼50% of the ETGs have EW(Hα) >6.0 Å. Of the LTGs, 95% show uniform radial color profiles, which can be interpreted as a red bulge plus an extended blue disk. The links between the two kinds of ETGs, e.g., those objects having remarkable ''blue-cores'' and those having flat color gradients, are less known and require future investigations. It is suggested that the LTGs follow a general model by which quenching first occurs in the core regions, and then finally extend to the rest of the galaxy. Our results can be re-examined and have important implications for the IFU surveys, such as MaNGA and SAMI

  2. A Mathematical Model for Temperature Induced Loosening due to Radial Expansion of Rectangle Thread Bolted Joints

    Directory of Open Access Journals (Sweden)

    Shiyuan Hou

    2015-01-01

    Full Text Available This paper proposed a mathematical model to investigate the radial expansion induced loosening of rectangle thread bolted joints that were subjected to cyclic temperature variation, which could cause slippage between contact pairs of engaged threads and bolt bearing. Firstly, integral equations were derived for the shear stress components caused by expansion difference, as well as the bearing and thread friction torque components, which depended on the temperature variation. Secondly, the relationship of displacement components was developed based on quasi-static hypotheses. Then, treating the rotation of bolt as plastic elongation, the bolt tension's evolution was obtained by using a one-dimensional bolted joint model. Numerical results showed that the temperature variation decreased the bearing and thread friction torque components, which could lead bolted joint to loosen. Finally, the effects of some associated factors on the progress were discussed.

  3. Thermal Analysis on Radial Flux Permanent Magnet Generator (PMG using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Hilman Syaeful A Syaeful A

    2011-05-01

    Full Text Available The main source of heat in the permanent magnet generator (PMG is the total losses which f come from winding losses, core losses and rotational losses. Total heat arising from such these losses must be properly distributed and maintained so as not to exceed the maximum allowable temperature to prevent damage to insulation on the winding and demagnetization on the permanent magnet machines. In this research, we consider thermal analysis which is occurred on the radial flux PMG by using finite element method to determine the extent to which the heat generated can be properly distributed. The simulation results show that there are no points of heat concentration or hot spot. The simulation maximum temperatures of the permanent magnet and the winding are 39.1oC and 72.5oC respectively while the experimental maximum temperature of the winding is 62oC.

  4. Radially truncated galactic discs

    NARCIS (Netherlands)

    Grijs, R. de; Kregel, M.; Wesson, K H

    2000-01-01

    Abstract: We present the first results of a systematic analysis of radially truncatedexponential discs for four galaxies of a sample of disc-dominated edge-onspiral galaxies. Edge-on galaxies are very useful for the study of truncatedgalactic discs, since we can follow their light distributions out

  5. Theoretical and Experimental Evaluation of the Temperature Distribution in a Dry Type Air Core Smoothing Reactor of HVDC Station

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2017-05-01

    Full Text Available The outdoor ultra-high voltage (UHV dry-type air-core smoothing reactors (DASR of High Voltage Direct Current systems are equipped with a rain cover and an acoustic enclosure. To study the convective heat transfer between the DASR and the surrounding air, this paper presents a coupled model of the temperature and fluid field based on the structural features and cooling manner. The resistive losses of encapsulations calculated by finite element method (FEM were used as heat sources in the thermal analysis. The steady fluid and thermal field of the 3-D reactor model were solved by the finite volume method (FVM, and the temperature distribution characteristics of the reactor were obtained. Subsequently, the axial and radial temperature distributions of encapsulation were investigated separately. Finally, an optical fiber temperature measurement scheme was used for an UHV DASR under natural convection conditions. Comparative analysis showed that the simulation results are in good agreement with the experimental data, which verifies the rationality and accuracy of the numerical calculation. These results can serve as a reference for the optimal design and maintenance of UHV DASRs.

  6. Numerical Simulation of Radial and Angular Distribution of γ-Ray's Energy Deposition in Scintillation Optical Fibre

    International Nuclear Information System (INIS)

    Tang Shibiao; Yin Zejie; Tang Yu; Huang Huan

    2006-01-01

    Angular and radial distributions of the energy deposition of γ-ray radiation in scintillation optical fibres are simulated and analysed using the Geant4 system. The results show a linear relation between the energy deposition and the radius of the fibres. The deposition is roughly inversely proportional to sinθ with θ the incident angle relative to the fibre axis. The results could provide corrections to the measurements of the scintillation fibres used in monitoring the γ-ray radiation

  7. Unstable Temperature Distribution in Friction Stir Welding

    Directory of Open Access Journals (Sweden)

    Sadiq Aziz Hussein

    2014-01-01

    Full Text Available In the friction stir welding process, a nonuniform and high generated temperature is undesirable. Unstable temperature and distribution affect thermal and residual stresses along the welding line, thus necessitating mitigation. This paper presents a simple method to prevent significant temperature difference along the welding line and also to help nullifying some defect types associated with this welding, such as end-hole, initial unwelded line, and deformed areas. In the experimental investigation, a heat and force thermocouple and dynamometer were utilized while couple-field thermomechanical models were used to evaluate temperature and its distribution, plastic strain, and material displacement. The suggested method generated uniform temperature distributions. Measurement results are discussed, showing a good correlation with predictions.

  8. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    Directory of Open Access Journals (Sweden)

    Panic B.

    2017-09-01

    Full Text Available The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas causing poor performance of the furnace. Such disruptions of flow may occur in the blast furnace due to high level of powder content in gas caused by large amount of coal dust/powder insufflated as fuel substitute. The paper describes the model test results of radial distribution of static pressure and powder hold up within metallurgical reactor. The measurements were carried out with the use of 3D physical model of two-phase flow gas-powder in the moving (descending packed bed. Sinter or blast furnace pellets were used as packed bed while carbon powder or iron powder were used as the powder. Wide diversity within both static pressure distribution and powder distribution along the radius of the reactor were observed once the change in the type of powder occurred.

  9. Electron temperature measurement in Maxwellian non-isothermal beam plasma of an ion thruster

    International Nuclear Information System (INIS)

    Zhang, Zun; Tang, Haibin; Kong, Mengdi; Zhang, Zhe; Ren, Junxue

    2015-01-01

    Published electron temperature profiles of the beam plasma from ion thrusters reveal many divergences both in magnitude and radial variation. In order to know exactly the radial distributions of electron temperature and understand the beam plasma characteristics, we applied five different experimental approaches to measure the spatial profiles of electron temperature and compared the agreement and disagreement of the electron temperature profiles obtained from these techniques. Experimental results show that the triple Langmuir probe and adiabatic poly-tropic law methods could provide more accurate space-resolved electron temperature of the beam plasma than other techniques. Radial electron temperature profiles indicate that the electrons in the beam plasma are non-isothermal, which is supported by a radial decrease (∼2 eV) of electron temperature as the plume plasma expands outward. Therefore, the adiabatic “poly-tropic law” is more appropriate than the isothermal “barometric law” to be used in electron temperature calculations. Moreover, the calculation results show that the electron temperature profiles derived from the “poly-tropic law” are in better agreement with the experimental data when the specific heat ratio (γ) lies in the range of 1.2-1.4 instead of 5/3

  10. Double-Sided Laser Heating in Radial Diffraction Geometry for Diamond Anvil Cell Deformation Experiments at Simultaneous High Pressures and Temperatures

    Science.gov (United States)

    Miyagi, L. M.; Kunz, M.; Couper, S.; Lin, F.; Yan, J.; Doran, A.; MacDowell, A. A.

    2017-12-01

    The rheology of rocks and minerals in the Earth's deep interior plays a primary role in controlling large scale geodynamic processes such as mantle convection and slab subduction. Plastic deformation resulting from these processes can lead to texture development and associated seismic anisotropy. If a detailed understanding of the link between deformation and seismic anisotropy is established, observations of seismic anisotropy can be used to understand the dynamic state in the deep Earth. However, performing deformation experiments at lower mantle pressure and temperature conditions are extremely challenging. Thus most deformation studies have been performed either at room temperature and high pressure or at reduced pressures and high temperature. Only a few extraordinary efforts have attained pressures and temperatures relevant to lower mantle. Therefore our ability to interpret observations of lower mantle seismic anisotropy in terms of mantle flow models remains limited. In order to expand the pressure and temperature range available for deformation of deep Earth relevant mineral phases, we have developed a laser heating system for in-situ double-sided heating in radial diffraction geometry at beamline 12.2.2 of the Advanced Light Source of Lawrence Berkeley National Laboratory. This allows texture and lattice strain measurements to be recorded at simultaneous high pressures and temperatures in the diamond anvil cell. This new system is integrated into the newly built axial laser heating system to allow for rapid and reliable transitioning between double-sided laser heating in axial and radial geometries. Transitioning to radial geometry is accomplished by redirecting the laser and imaging paths from 0° and 180° to 90° and 270°. To redirect the 90° path, a motorized periscope mirror pair with an objective lens can be inserted into the downstream axial beam path. The 270° redirection is accomplished by removing the upstream axial objective lens and

  11. Feature Extraction Method for High Impedance Ground Fault Localization in Radial Power Distribution Networks

    DEFF Research Database (Denmark)

    Jensen, Kåre Jean; Munk, Steen M.; Sørensen, John Aasted

    1998-01-01

    A new approach to the localization of high impedance ground faults in compensated radial power distribution networks is presented. The total size of such networks is often very large and a major part of the monitoring of these is carried out manually. The increasing complexity of industrial...... of three phase voltages and currents. The method consists of a feature extractor, based on a grid description of the feeder by impulse responses, and a neural network for ground fault localization. The emphasis of this paper is the feature extractor, and the detection of the time instance of a ground fault...... processes and communication systems lead to demands for improved monitoring of power distribution networks so that the quality of power delivery can be kept at a controlled level. The ground fault localization method for each feeder in a network is based on the centralized frequency broadband measurement...

  12. An integrated approach to selecting materials for fuel cladding in advanced high-temperature reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rangacharyulu, C., E-mail: chary.r@usask.ca [Univ. of Saskatchewan, Saskatoon, SK (Canada); Guzonas, D.A.; Pencer, J.; Nava-Dominguez, A.; Leung, L.K.H. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    An integrated approach has been developed for selection of fuel cladding materials for advanced high-temperature reactors. Reactor physics, thermalhydraulic and material analyses are being integrated in a systematic study comparing various candidate fuel-cladding alloys. The analyses established the axial and radial neutron fluxes, power distributions, axial and radial temperature distributions, rates of defect formation and helium production using AECL analytical toolsets and experimentally measured corrosion rates to optimize the material composition for fuel cladding. The project has just been initiated at University of Saskatchewan. Some preliminary results of the analyses are presented together with the path forward for the project. (author)

  13. GALAXY ENVIRONMENTS OVER COSMIC TIME: THE NON-EVOLVING RADIAL GALAXY DISTRIBUTIONS AROUND MASSIVE GALAXIES SINCE z = 1.6

    International Nuclear Information System (INIS)

    Tal, Tomer; Van Dokkum, Pieter G.; Leja, Joel; Franx, Marijn; Wake, David A.; Whitaker, Katherine E.

    2013-01-01

    We present a statistical study of the environments of massive galaxies in four redshift bins between z = 0.04 and z = 1.6, using data from the Sloan Digital Sky Survey and the NEWFIRM Medium Band Survey. We measure the projected radial distribution of galaxies in cylinders around a constant number density selected sample of massive galaxies and utilize a statistical subtraction of contaminating sources. Our analysis shows that massive primary galaxies typically live in group halos and are surrounded by 2-3 satellites with masses more than one-tenth of the primary galaxy mass. The cumulative stellar mass in these satellites roughly equals the mass of the primary galaxy itself. We further find that the radial number density profile of galaxies around massive primaries has not evolved significantly in either slope or overall normalization in the past 9.5 Gyr. A simplistic interpretation of this result can be taken as evidence for a lack of mergers in the studied groups and as support for a static evolution model of halos containing massive primaries. Alternatively, there exists a tight balance between mergers and accretion of new satellites such that the overall distribution of galaxies in and around the halo is preserved. The latter interpretation is supported by a comparison to a semi-analytic model, which shows a similar constant average satellite distribution over the same redshift range.

  14. Design of Radial Turbo-Expanders for Small Organic Rankine Cycle System

    Science.gov (United States)

    Arifin, M.; Pasek, A. D.

    2015-09-01

    This paper discusses the design of radial turbo-expanders for ORC systems. Firstly, the rotor blades were design and the geometry and the perfromance were calculated using several working fluid such as R134a, R143a, R245fa, n-Pentane, and R123. Then, a numerical study was carried out in the fluid flow area with R134a and R123 as the working fluid. Analyses were performed using Computational Fluid Dynamics (CFD) ANSYS CFX on two real gas models, with the k-epsilon and SST (shear stress transport) turbulence models. The results analysis shows the distribution of Mach number, pressure, velocity and temperature along the rotor blade of the radial turbo-expanders and estimation of performance at various operating conditions. CFD analysis show that if the flow area divided into 250,000 grid mesh, and using real gas model SST at steady state condition, 0.4 kg/s of mass flow rate, 15,000 rpm rotor speed, 5 bar inlet pressure, and 373K inlet temperature, the turbo expander produces 6.7 kW, and 5.5 kW of power when using R134a and R123 respectively.

  15. Radial distributions of magnetic field strength in the solar corona as derived from data on fast halo CMEs

    Science.gov (United States)

    Fainshtein, Victor; Egorov, Yaroslav

    2018-03-01

    In recent years, information about the distance between the body of rapid coronal mass ejection (CME) and the associated shock wave has been used to measure the magnetic field in the solar corona. In all cases, this technique allows us to find coronal magnetic field radial profiles B(R) applied to the directions almost perpendicular to the line of sight. We have determined radial distributions of magnetic field strength along the directions close to the Sun-Earth axis. For this purpose, using the "ice-cream cone" model and SOHO/LASCO data, we found 3D characteristics for fast halo coronal mass ejections (HCMEs) and for HCME-related shocks. With these data, we managed to obtain the B(R) distributions as far as ≈43 solar radii from the Sun's center, which is approximately twice as far as those in other studies based on LASCO data. We have concluded that to improve the accuracy of this method for finding the coronal magnetic field we should develop a technique for detecting CME sites moving in the slow and fast solar wind. We propose a technique for selecting CMEs whose central (paraxial) part actually moves in the slow wind.

  16. RADIAL FORCE IMPACT ON THE FRICTION COEFFICIENT AND TEMPERATURE OF A SELF-LUBRICATING PLAIN BEARING

    Directory of Open Access Journals (Sweden)

    Nada Bojić

    2017-12-01

    Full Text Available Self-lubricating bearings are available in spherical, plain, flanged journal, and rod end bearing configurations. They were originally developed to eliminate the need for re-lubrication, to provide lower torque and to solve application problems where the conventional metal-to-metal bearings would not perform satisfactorily, for instance, in the presence of high frequency vibrations. Among the dominant tribological parameters of the self-lubricating bearing, two could be singled out: the coefficient of friction and temperature. To determine these parameters, an experimental method was applied in this paper. By using this method, the coefficient of friction and temperature were identified and their correlation was established. The aim of this research was to determine the effect of radial force on tribological parameters in order to predict the behavior of sliding bearings with graphite in real operating conditions.

  17. A peculiar distribution of radial velocities of faint radio-galaxies with 13.0<=msub(corr)<=15.5

    International Nuclear Information System (INIS)

    Karoji, H.; Nottale, L.; Vigier, J.-P.

    1976-01-01

    A sample of 41 radio-galaxies with 13.0<=msub(corr)<=15.5 has been analyzed to test the angular redshift anisotropy discovered on Sc I galaxies by Rubin, Rubin and Ford (1973). The sample does not present their anisotropy but contains an even more curious distribution of radial velocities which suggests that the Rubin-Ford effect results from an anomalous redshift of light when it travels through clusters of galaxies. (Auth.)

  18. Radial Flow in a Multiphase Transport Model at FAIR Energies

    Directory of Open Access Journals (Sweden)

    Soumya Sarkar

    2018-01-01

    Full Text Available Azimuthal distributions of radial velocities of charged hadrons produced in nucleus-nucleus (AB collisions are compared with the corresponding azimuthal distribution of charged hadron multiplicity in the framework of a multiphase transport (AMPT model at two different collision energies. The mean radial velocity seems to be a good probe for studying radial expansion. While the anisotropic parts of the distributions indicate a kind of collective nature in the radial expansion of the intermediate “fireball,” their isotropic parts characterize a thermal motion. The present investigation is carried out keeping the upcoming Compressed Baryonic Matter (CBM experiment to be held at the Facility for Antiproton and Ion Research (FAIR in mind. As far as high-energy heavy-ion interactions are concerned, CBM will supplement the Relativistic Heavy-Ion Collider (RHIC and Large Hadron Collider (LHC experiments. In this context our simulation results at high baryochemical potential would be interesting, when scrutinized from the perspective of an almost baryon-free environment achieved at RHIC and LHC.

  19. Distributed temperature sensor testing in liquid sodium

    Energy Technology Data Exchange (ETDEWEB)

    Gerardi, Craig; Bremer, Nathan; Lisowski, Darius; Lomperski, Stephen

    2017-02-01

    Rayleigh-backscatter-based distributed fiber optic sensors were immersed in sodium to obtain high-resolution liquid-sodium temperature measurements. Distributed temperature sensors (DTSs) functioned well up to 400°C in a liquid sodium environment. The DTSs measured sodium column temperature and the temperature of a complex geometrical pattern that leveraged the flexibility of fiber optics. A single Ø 360 lm OD sensor registered dozens of temperatures along a length of over one meter at 100 Hz. We also demonstrated the capability to use a single DTS to simultaneously detect thermal interfaces (e.g. sodium level) and measure temperature.

  20. Radial Distribution of the Nanosecond Dielectric Barrier Discharge Current in Atmospheric-Pressure Air

    Science.gov (United States)

    Malashin, M. V.; Moshkunov, S. I.; Khomich, V. Yu.; Shershunova, E. A.

    2018-01-01

    Experimental results on the radial distribution of the nanosecond dielectric barrier discharge (DBD) current in flat millimeter air gaps under atmospheric pressure and natural humidity of 40-60% at a voltage rise rate at the electrodes of 250 V/ns are presented. The time delay of the appearance of discharge currents was observed to increase from the center to the periphery of the air gap at discharge gap heights above 3 mm, which correlated with the appearance of constricted channels against the background of the volume DBD plasma. Based on the criterion of the avalanche-streamer transition, it is found out that the development of a nanosecond DBD in air gaps of 1-3 mm occurs by the streamer mechanism.

  1. Temperature-monitored optical treatment for radial tissue expansion.

    Science.gov (United States)

    Bak, Jinoh; Kang, Hyun Wook

    2017-07-01

    Esophageal stricture occurs in 7-23% of patients with gastroesophageal reflux disease. However, the current treatments including stent therapy, balloon dilation, and bougienage involve limitations such as stent migration, formation of the new strictures, and snowplow effect. The purpose of the current study was to investigate the feasibility of structural expansion in tubular tissue ex vivo during temperature-monitored photothermal treatment with a diffusing applicator for esophageal stricture. Porcine liver was used as an ex vivo tissue sample for the current study. A glass tube was used to maintain a constant distance between the diffuser and tissue surface and to evaluate any variations in the luminal area after 10-W 1470-nm laser irradiation for potential stricture treatment. The 3D goniometer measurements confirmed roughly isotropic distribution with less than 10% deviation from the average angular intensity over 2π (i.e., 0.86 ± 0.09 in arbitrary unit) from the diffusing applicator. The 30-s irradiation increased the tissue temperature up to 72.5 °C, but due to temperature feedback, the interstitial tissue temperature became saturated at 70 °C (i.e., steady-state error = ±0.4 °C). The irradiation times longer than 5 s presented area expansion index of 1.00 ± 0.04, signifying that irreversible tissue denaturation permanently deformed the lumen in a circular shape and secured the equivalent luminal area to that of the glass tube. Application of a temperature feedback controller for photothermal treatment with the diffusing applicator can regulate the degree of thermal denaturation to feasibly treat esophageal stricture in a tubular tissue.

  2. AIRGAP MAGNETIC INDUCTION DISTRIBUTION IN A COAXIALLY-LINEAR SYNCHRONOUS MOTOR WITH AXIAL AND RADIAL DIRECTION OF THE RUNNER PERMANENT MAGNETS MAGNETIZATION

    Directory of Open Access Journals (Sweden)

    Abbasian Mohsen

    2013-02-01

    Full Text Available Results of theoretical and experimental research on magnetic induction distribution in the air gap of a coaxially-linear synchronous motor with reciprocal motion within the pole pitch and axial and radial direction of the permanent magnets magnetization are presented.

  3. Simulation of magnetic induction distribution in a coaxial linear motor with axial and radial direction of permanent magnets magnetization

    Directory of Open Access Journals (Sweden)

    G.M. Golenkov

    2014-03-01

    Full Text Available The paper presents results of computer simulation and experimental study of magnetic induction distribution in a coaxial linear motor air gap throughout the length of the runner active part at different heights of the air gap between the runner and the inductor magnetic core for motors with axial and radial direction of the permanent magnets magnetization.

  4. Axial and radial distribution of neutron fluxes in the irradiation channels of the Ghana Research Reactor-1 using foil activation analysis and Monte Carlo

    International Nuclear Information System (INIS)

    Abrefah, G.R.

    2009-02-01

    The Monte-Carlo method and experimental methods were used to determine the neutron fluxes in the irradiation channels of the Ghana Research Reactor -1. The MCNP5 code was used for this purpose to simulate the radial and axial distribution of the neutron fluxes within all the ten irradiation channels. The results obtained were compared with the experimental results. After the MCNP simulation and experimental procedure, it was observed that axially, the fluxes rise to a peak before falling and then finally leveling out. Axially and radially, it was also observed that the fluxes in the centre of the channels were lower than on the sides. Radially, the fluxes dip in the centre while it increases steadily towards the sides of the channels. The results have shown that there are flux variations within the irradiation channels both axially and radially. (au)

  5. Performance of a high-work low aspect ration turbine tested with a realistic inlet radial temperature profile

    Science.gov (United States)

    Stabe, R. G.; Whitney, W. J.; Moffitt, T. P.

    1984-01-01

    Experimental results are presented for a 0.767 scale model of the first stage of a two-stage turbine designed for a high by-pass ratio engine. The turbine was tested with both uniform inlet conditions and with an inlet radial temperature profile simulating engine conditions. The inlet temperature profile was essentially mixed-out in the rotor. There was also substantial underturning of the exit flow at the mean diameter. Both of these effects were attributed to strong secondary flows in the rotor blading. There were no significant differences in the stage performance with either inlet condition when differences in tip clearance were considered. Performance was very close to design intent in both cases.

  6. Multi objective Flower Pollination Algorithm for solving capacitor placement in radial distribution system using data structure load flow analysis

    Directory of Open Access Journals (Sweden)

    Tamilselvan V.

    2016-06-01

    Full Text Available The radial distribution system is a rugged system, it is also the most commonly used system, which suffers by loss and low voltage at the end bus. This loss can be reduced by the use of a capacitor in the system, which injects reactive current and also improves the voltage magnitude in the buses. The real power loss in the distribution line is the I2R loss which depends on the current and resistance. The connection of the capacitor in the bus reduces the reactive current and losses. The loss reduction is equal to the increase in generation, necessary for the electric power provided by firms. For consumers, the quality of power supply depends on the voltage magnitude level, which is also considered and hence the objective of the problem becomes the multi objective of loss minimization and the minimization of voltage deviation. In this paper, the optimal location and size of the capacitor is found using a new computational intelligent algorithm called Flower Pollination Algorithm (FPA. To calculate the power flow and losses in the system, novel data structure load flow is introduced. In this, each bus is considered as a node with bus associated data. Links between the nodes are distribution lines and their own resistance and reactance. To validate the developed FPA solutions standard test cases, IEEE 33 and IEEE 69 radial distribution systems are considered.

  7. Revisiting the radial abundance gradients of nitrogen and oxygen of the Milky Way

    Science.gov (United States)

    Esteban, C.; García-Rojas, J.

    2018-05-01

    We present spectra obtained with the 10.4 m Gran Telescopio Canarias telescope of 13 Galactic H II regions, most of them of very low ionisation degree. The objects are located along the Galactic disc, with RG from 5.7 to 16.1 kpc. We determine Te([N II]) for all of them. We obtain - for the first time - a radial abundance gradient of N that is independent on the ionisation correction factor. The radial distribution of the N/O ratio is almost flat, indicating that the bulk of N is not formed by standard secondary processes. We have made a reassessment of the radial O abundance gradient combining our results with previous similar ones by Esteban et al. (2017); producing a homogeneous dataset of 35 H II regions with direct determinations of the electron temperature. We report the possible presence of a flattening or drop of the O abundance in the inner part of the Galactic disc. This result confirms previous findings from metallicity distributions based on Cepheids and red giants. Finally, we find that the scatter of the N and O abundances of H II regions with respect to the gradient fittings is not substantially larger than the observational uncertainties, indicating that both chemical elements seem to be well mixed in the interstellar gas at a given distance along the Galactic disc

  8. Effect of the borax mass and pre-spray medium temperature on droplet size and velocity vector distributions of intermittently sprayed starchy solutions.

    Science.gov (United States)

    Naz, Muhammad Yasin; Sulaiman, Shaharin Anwar; Ariwahjoedi, Bambang

    2015-02-07

    Spray coating technology has demonstrated great potential in the slow release fertilizers industry. The better understanding of the key spray parameters benefits both the environment and low cost coating processes. The use of starch based materials to coat the slow release fertilizers is a new development. However, the hydraulic spray jet breakup of the non-Newtonian starchy solutions is a complex phenomenon and very little known. The aim of this research was to study the axial and radial distributions of the Sauter Mean Diameter (SMD) and velocity vectors in pulsing spray patterns of native and modified tapioca starch solutions. To meet the objective, high speed imaging and Phase Doppler Anemometry (PDA) techniques were employed to characterize the four compositions of the starch-urea-borax complex namely S0, S1, S2 and S3. The unheated solutions exhibited very high viscosities ranging from 2035 to 3030 cP. No jet breakup was seen at any stage of the nozzle operation at an injection pressure of 1-5 bar. However, at 80 °C temperature and 5 bar pressure, the viscosity was reduced to 455 to 638 cP and dense spray patterns emerged from the nozzle obscuring the PDA signals. The axial size distribution revealed a significant decrease in SMD along the spray centreline. The smallest axial SMD (51 to 79 μm) was noticed in S0 spray followed by S1, S2 and S3. Unlikely, the radial SMD in S0 spray did not vary significantly at any stage of the spray injection. This trend was attributed to the continuous growth of the surface wave instabilities on the native starch sheet. However, SMD obtained with S1, S2 and S3 varied appreciably along the radial direction. The mean velocity vector profiles followed the non-Gaussian distribution. The constant vector distributions were seen in the near nozzle regions, where the spray was in the phase of development. In far regions, the velocity vectors were poly-dispersed and a series of ups and downs were seen in the respective radial

  9. Measuring trace gas emission from multi-distributed sources using vertical radial plume mapping (VRPM) and backward Lagrangian stochastic (bLS) techniques

    Science.gov (United States)

    Two micrometeorological techniques for measuring trace gas emission rates from distributed area sources were evaluated using a variety of synthetic area sources. The accuracy of the vertical radial plume mapping (VRPM) and the backward Lagrangian (bLS) techniques with an open-path optical spectrosco...

  10. The multi-layered ring under parabolic distribution of radial stresses combined with uniform internal and external pressure

    Directory of Open Access Journals (Sweden)

    Christos F. Markides

    2017-04-01

    Full Text Available A recently introduced solution for the stress- and displacement-fields, developed in a multi-layered circular ring, composed of a finite number of linearly elastic concentric layers, subjected to a parabolic distribution of ra-dial stresses, is here extended to encompass a more general loading scheme, closer to actual conditions. The loading scheme includes, besides the para¬-bolic radial stresses, a combination of uniform pressures acting along the outer- and inner- most boundaries of the layered ring. The analytic solution of the problem is achieved by adopting Savin’s pioneering approach for an infinite plate with a hole strengthened by rings. Taking advantage of the results provided by the ana¬lytic solution, a numerical model, simulating the configuration of a three-layered ring (quite commonly encountered in practic¬al applications is validated. The numerical model is then used for a parametric analysis enlightening some crucial aspects of the overall response of the ring.

  11. An Edge Rotation and Temperature Diagnostic on NSTX

    International Nuclear Information System (INIS)

    Biewer, T.M.; Bell, R.E.; Feder, R.; Johnson, D.W.; Palladino, R.W.

    2003-01-01

    A new diagnostic for the National Spherical Torus Experiment (NSTX) is described whose function is to measure ion rotation and temperature at the plasma edge. The diagnostic is sensitive to C III, C IV, and He II intrinsic emission, covering a radial region of 15 cm at the extreme edge of the outboard midplane. Thirteen chords are distributed between toroidal and poloidal views, allowing the toroidal and poloidal rotation and temperature of the plasma edge to be simultaneously measured with 10 ms resolution. Combined with the local pressure gradient and the EFIT code reconstructed magnetic field profile, the edge flow gives a measure of the local radial electric field

  12. Determination of radial profile of ICF hot spot's state by multi-objective parameters optimization

    International Nuclear Information System (INIS)

    Dong Jianjun; Deng Bo; Cao Zhurong; Ding Yongkun; Jiang Shaoen

    2014-01-01

    A method using multi-objective parameters optimization is presented to determine the radial profile of hot spot temperature and density. And a parameter space which contain five variables: the temperatures at center and the interface of fuel and remain ablator, the maximum model density of remain ablator, the mass ratio of remain ablator to initial ablator and the position of interface between fuel and the remain ablator, is used to described the hot spot radial temperature and density. Two objective functions are set as the variances of normalized intensity profile from experiment X-ray images and the theory calculation. Another objective function is set as the variance of experiment average temperature of hot spot and the average temperature calculated by theoretical model. The optimized parameters are obtained by multi-objective genetic algorithm searching for the five dimension parameter space, thereby the optimized radial temperature and density profiles can be determined. The radial temperature and density profiles of hot spot by experiment data measured by KB microscope cooperating with X-ray film are presented. It is observed that the temperature profile is strongly correlated to the objective functions. (authors)

  13. Distributed temperature and distributed acoustic sensing for remote and harsh environments

    Science.gov (United States)

    Mondanos, Michael; Parker, Tom; Milne, Craig H.; Yeo, Jackson; Coleman, Thomas; Farhadiroushan, Mahmoud

    2015-05-01

    Advances in opto-electronics and associated signal processing have enabled the development of Distributed Acoustic and Temperature Sensors. Unlike systems relying on discrete optical sensors a distributed system does not rely upon manufactured sensors but utilises passive custom optical fibre cables resistant to harsh environments, including high temperature applications (600°C). The principle of distributed sensing is well known from the distributed temperature sensor (DTS) which uses the interaction of the source light with thermal vibrations (Raman scattering) to determine the temperature at all points along the fibre. Distributed Acoustic Sensing (DAS) uses a novel digital optical detection technique to precisely capture the true full acoustic field (amplitude, frequency and phase) over a wide dynamic range at every point simultaneously. A number of signal processing techniques have been developed to process a large array of acoustic signals to quantify the coherent temporal and spatial characteristics of the acoustic waves. Predominantly these systems have been developed for the oil and gas industry to assist reservoir engineers in optimising the well lifetime. Nowadays these systems find a wide variety of applications as integrity monitoring tools in process vessels, storage tanks and piping systems offering the operator tools to schedule maintenance programs and maximize service life.

  14. Observational hints of radial migration in disc galaxies from CALIFA

    NARCIS (Netherlands)

    Ruiz-Lara, T.; Pérez, I.; Florido, E.; Sánchez-Blázquez, P.; Méndez-Abreu, J.; Sánchez-Menguiano, L.; Sánchez, S. F.; Lyubenova, M.; Falcón-Barroso, J.; van de Ven, G.; Marino, R. A.; de Lorenzo-Cáceres, A.; Catalán-Torrecilla, C.; Costantin, L.; Bland-Hawthorn, J.; Galbany, L.; García-Benito, R.; Husemann, B.; Kehrig, C.; Márquez, I.; Mast, D.; Walcher, C. J.; Zibetti, S.; Ziegler, B.

    2017-01-01

    Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important,

  15. Computer simulation of radial transport in tandem mirror machines

    International Nuclear Information System (INIS)

    Gilmore, J.M.

    1979-01-01

    A code used for simulation of classical radial transport in the 2XIIB experiment has been modified to simulate radial transport in TMX. Results have been obtained using classical transport coefficients and also using very simple trial neoclassical resonant transport coefficients. Comparison of the results obtained with solely classical transport and with both classical and neo-classical transport indicate that neoclassical transport depresses the ion density by approximately 5%. The central cell ion temperature is increased by approximately by the neo-classical transport, as is the electron temperature

  16. Field Emission and Radial Distribution Function Studies of Fractal-like Amorphous Carbon Nanotips

    Directory of Open Access Journals (Sweden)

    Lebrón-Colón M

    2009-01-01

    Full Text Available Abstract The short-range order of individual fractal-like amorphous carbon nanotips was investigated by means of energy-filtered electron diffraction in a transmission electron microscope (TEM. The nanostructures were grown in porous silicon substrates in situ within the TEM by the electron beam-induced deposition method. The structure factorS(k and the reduced radial distribution functionG(r were calculated. From these calculations a bond angle of 124° was obtained which suggests a distorted graphitic structure. Field emission was obtained from individual nanostructures using two micromanipulators with sub-nanometer positioning resolution. A theoretical three-stage model that accounts for the geometry of the nanostructures provides a value for the field enhancement factor close to the one obtained experimentally from the Fowler-Nordheim law.

  17. Radial gas turbine design

    Energy Technology Data Exchange (ETDEWEB)

    Krausche, S.; Ohlsson, Johan

    1998-04-01

    The objective of this work was to develop a program dealing with design point calculations of radial turbine machinery, including both compressor and turbine, with as few input data as possible. Some simple stress calculations and turbine metal blade temperatures were also included. This program was then implanted in a German thermodynamics program, Gasturb, a program calculating design and off-design performance of gas turbines. The calculations proceed with a lot of assumptions, necessary to finish the task, concerning pressure losses, velocity distribution, blockage, etc., and have been correlated with empirical data from VAT. Most of these values could have been input data, but to prevent the user of the program from drowning in input values, they are set as default values in the program code. The output data consist of geometry, Mach numbers, predicted component efficiency etc., and a number of graphical plots of geometry and velocity triangles. For the cases examined, the error in predicted efficiency level was within {+-} 1-2% points, and quite satisfactory errors in geometrical and thermodynamic conditions were obtained Examination paper. 18 refs, 36 figs

  18. Radial distributions of magnetic field strength in the solar corona as derived from data on fast halo CMEs

    Directory of Open Access Journals (Sweden)

    Fainshtein V.G.

    2018-03-01

    Full Text Available In recent years, information about the distance between the body of rapid coronal mass ejection (CME and the associated shock wave has been used to measure the magnetic field in the solar corona. In all cases, this technique allows us to find coronal magnetic field radial profiles B(R applied to the directions almost perpendicular to the line of sight. We have determined radial distributions of magnetic field strength along the directions close to the Sun–Earth axis. For this purpose, using the “ice-cream cone” model and SOHO/LASCO data, we found 3D characteristics for fast halo coronal mass ejections (HCMEs and for HCME-related shocks. With these data we managed to obtain the B(R distributions as far as ≈43 solar radii from the Sun's center, which is approximately twice as far as those in other studies based on LASCO data. We have concluded that to improve the accuracy of this method for finding the coronal magnetic field we should develop a technique for detecting CME parts moving in the slow and fast solar wind. We propose a technique for selecting CMEs whose central (paraxial part actually moves in the slow wind.

  19. Performance of a high-work low aspect ratio turbine tested with a realistic inlet radial temperature profile

    Science.gov (United States)

    Stabe, R. G.; Whitney, W. J.; Moffitt, T. P.

    1984-01-01

    Experimental results are presented for a 0.767 scale model of the first stage of a two-stage turbine designed for a high by-pass ratio engine. The turbine was tested with both uniform inlet conditions and with an inlet radial temperature profile simulating engine conditions. The inlet temperature profile was essentially mixed-out in the rotor. There was also substantial underturning of the exit flow at the mean diameter. Both of these effects were attributed to strong secondary flows in the rotor blading. There were no significant differences in the stage performance with either inlet condition when differences in tip clearance were considered. Performance was very close to design intent in both cases. Previously announced in STAR as N84-24589

  20. The radial-hedgehog solution in Landau–de Gennes' theory for nematic liquid crystals

    KAUST Repository

    MAJUMDAR, APALA

    2011-09-06

    We study the radial-hedgehog solution in a three-dimensional spherical droplet, with homeotropic boundary conditions, within the Landau-de Gennes theory for nematic liquid crystals. The radial-hedgehog solution is a candidate for a global Landau-de Gennes minimiser in this model framework and is also a prototype configuration for studying isolated point defects in condensed matter physics. The static properties of the radial-hedgehog solution are governed by a non-linear singular ordinary differential equation. We study the analogies between Ginzburg-Landau vortices and the radial-hedgehog solution and demonstrate a Ginzburg-Landau limit for the Landau-de Gennes theory. We prove that the radial-hedgehog solution is not the global Landau-de Gennes minimiser for droplets of finite radius and sufficiently low temperatures and prove the stability of the radial-hedgehog solution in other parameter regimes. These results contain quantitative information about the effect of geometry and temperature on the properties of the radial-hedgehog solution and the associated biaxial instabilities. © Copyright Cambridge University Press 2011.

  1. The radial-hedgehog solution in Landau–de Gennes' theory for nematic liquid crystals

    KAUST Repository

    MAJUMDAR, APALA

    2011-01-01

    We study the radial-hedgehog solution in a three-dimensional spherical droplet, with homeotropic boundary conditions, within the Landau-de Gennes theory for nematic liquid crystals. The radial-hedgehog solution is a candidate for a global Landau-de Gennes minimiser in this model framework and is also a prototype configuration for studying isolated point defects in condensed matter physics. The static properties of the radial-hedgehog solution are governed by a non-linear singular ordinary differential equation. We study the analogies between Ginzburg-Landau vortices and the radial-hedgehog solution and demonstrate a Ginzburg-Landau limit for the Landau-de Gennes theory. We prove that the radial-hedgehog solution is not the global Landau-de Gennes minimiser for droplets of finite radius and sufficiently low temperatures and prove the stability of the radial-hedgehog solution in other parameter regimes. These results contain quantitative information about the effect of geometry and temperature on the properties of the radial-hedgehog solution and the associated biaxial instabilities. © Copyright Cambridge University Press 2011.

  2. Temperature Distribution in a Displacement Ventilated Room

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The vertical temperature gradient is normally given as a linear temperature distribution between a minimum temperature close to the floor and a maximum temperature close to the ceiling. The minimum temperature can either be a constant fraction of a load dependent difference or it can be connected...

  3. Effects of Transverse Power Distribution on Fuel Temperature

    International Nuclear Information System (INIS)

    Jo, Daeseong; Park, Jonghark; Seo, Chul Gyo; Chae, Heetaek

    2014-01-01

    In the present study, transverse power distributions with segments of 4 and 18 are evaluated. Based on the power distribution, the fuel temperatures are evaluated with a consideration of lateral heat conduction. In the present study, the effect of the transverse power distribution on the fuel temperature is investigated. The transverse power distributions with variation of fuel segment number are evaluated. The maximum power peaking with 12 segments is higher than that with 4 segments. Based on the calculation, 6-order polynomial is generated to express the transverse power distributions. The maximum power peaking factor increases with segments. The averaged power peaking is 2.10, and the maximum power peaking with 18 segments is 2.80. With the uniform power distribution, the maximum fuel temperature is found in the middle of the fuel. As the power near the side ends of the fuel increases, the maximum fuel temperature is found near the side ends. However, the maximum fuel temperature is not found where the maximum transverse power is. This is because the high power locally released from the edge of the fuel is laterally conducted to the cladding. As a result of the present study, it can be concluded that the effect of the high power peaking at the edge of the fuel on the fuel outer wall temperature is not significant

  4. Properties of magnetocaloric materials with a distribution of Curie temperatures

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Bjørk, Rasmus; Smith, Anders

    2012-01-01

    The magnetocaloric properties of inhomogeneous ferromagnets that contain distributions of Curie temperatures are considered as a function of the width of such a distribution. Assuming a normal distribution of the Curie temperature, the average adiabatic temperature change, ΔTad, the isothermal...... of the distribution, explaining the observed mismatch of peak temperatures reported in experiments. Also, the field dependence of ΔTad and Δs is found to depend on the width of the distribution....

  5. A fuzzy genetic approach for network reconfiguration to enhance voltage stability in radial distribution systems

    International Nuclear Information System (INIS)

    Sahoo, N.C.; Prasad, K.

    2006-01-01

    This paper presents a fuzzy genetic approach for reconfiguration of radial distribution systems (RDS) so as to maximize the voltage stability of the network for a specific set of loads. The network reconfiguration involves a mechanism for selection of the best set of branches to be opened, one from each loop, such that the reconfigured RDS possesses desired performance characteristics. This discrete solution space is better handled by the proposed scheme, which maximizes a suitable optimizing function (computed using two different approaches). In the first approach, this function is chosen as the average of a voltage stability index of all the buses in the RDS, while in the second approach, the complete RDS is reduced to a two bus equivalent system and the optimizing function is the voltage stability index of this reduced two bus system. The fuzzy genetic algorithm uses a suitable coding and decoding scheme for maintaining the radial nature of the network at every stage of genetic evolution, and it also uses a fuzzy rule based mutation controller for efficient search of the solution space. This method, tested on 69 bus and 33 bus RDSs, shows promising results for the both approaches. It is also observed that the network losses are reduced when the voltage stability is enhanced by the network reconfiguration

  6. Controlling Voltage Levels of Distribution Network-Radial Feeder after Connecting Wind Turbines to the Network

    Directory of Open Access Journals (Sweden)

    Muhammad Al Badri

    2017-11-01

    Full Text Available Several factors in power generation and supply need to be taken into account such as shortages of energy supply, system stability, and energy quality and system disruption due to network losses, industrial development and population expansion. The addition of wind turbines to the distribution network is of great benefit in providing additional power and solving these problems, but this addition is accompanied by the problem of low voltage network. This research found optimal solutions to the problem of low voltage distribution network after connecting wind turbines. The main idea of this paper is to optimize the low-voltage problem as a result of connecting the wind turbines to the "far end" of the radial feeder for a distribution network and to obtain a voltage level within an acceptable and stable range. The problem of low voltage solved by using the load-drop compensation, capacitor-bank and “doubly-fed” induction generators. The results of this study were based on the operation of the entire design of the simulation system which would be compatible with the reality of the energy flow of all network components by using the PSCAD program. The present analysis program revealed an optimum solution for the low voltage profile of the distribution network after connecting the wind turbine.

  7. Observational hints of radial migration in disc galaxies from CALIFA

    Science.gov (United States)

    Ruiz-Lara, T.; Pérez, I.; Florido, E.; Sánchez-Blázquez, P.; Méndez-Abreu, J.; Sánchez-Menguiano, L.; Sánchez, S. F.; Lyubenova, M.; Falcón-Barroso, J.; van de Ven, G.; Marino, R. A.; de Lorenzo-Cáceres, A.; Catalán-Torrecilla, C.; Costantin, L.; Bland-Hawthorn, J.; Galbany, L.; García-Benito, R.; Husemann, B.; Kehrig, C.; Márquez, I.; Mast, D.; Walcher, C. J.; Zibetti, S.; Ziegler, B.; Califa Team

    2017-07-01

    Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important, galaxies with different surface brightness (SB) profiles must display differences in their stellar population properties. Aims: We investigate the role of radial migration in the light distribution and radial stellar content by comparing the inner colour, age, and metallicity gradients for galaxies with different SB profiles. We define these inner parts, avoiding the bulge and bar regions and up to around three disc scale lengths (type I, pure exponential) or the break radius (type II, downbending; type III, upbending). Methods: We analysed 214 spiral galaxies from the CALIFA survey covering different SB profiles. We made use of GASP2D and SDSS data to characterise the light distribution and obtain colour profiles of these spiral galaxies. The stellar age and metallicity profiles were computed using a methodology based on full-spectrum fitting techniques (pPXF, GANDALF, and STECKMAP) to the Integral Field Spectroscopic CALIFA data. Results: The distributions of the colour, stellar age, and stellar metallicity gradients in the inner parts for galaxies displaying different SB profiles are unalike as suggested by Kolmogorov-Smirnov and Anderson-Darling tests. We find a trend in which type II galaxies show the steepest profiles of all, type III show the shallowest, and type I display an intermediate behaviour. Conclusions: These results are consistent with a scenario in which radial migration is more efficient for type III galaxies than for type I systems, where type II galaxies present the lowest radial migration efficiency. In such a scenario, radial migration mixes the stellar content, thereby flattening the radial stellar properties and shaping different SB profiles. However

  8. Radial Color Gradient in a Globular Cluster 1. M68

    Directory of Open Access Journals (Sweden)

    Sukyoung Yi

    1990-12-01

    Full Text Available Stars in M68 from the observed color-magnitude diagrams with CCD were integrated to find any radial gradient. The result shows that M68 has a slightly bluer core. The main cause of these calculated radial color variations seems to come from the random distribution of giants.

  9. Cesium relocation in mixed-oxide fuel pins resulting from increased temperature reirradiation

    International Nuclear Information System (INIS)

    Lawrence, L.A.; Woodley, R.E.; Weber, E.T.

    1976-06-01

    Mixed-oxide fuel pins from EBR-II test subassemblies PNL-3 and PNL-4 were reirradiated in the GETR to study effects of increased fuel and cladding temperatures on chemical and thermomechanical behavior. Radial and axial distributions of cesium were obtained using postirradiation nondestructive precision gamma-scanning techniques. Data presented relate to the dependence of cesium distribution and transport processes on temperature gradients which were altered after substantial steady-state operation

  10. Effects of drive current rise-time and initial load density distribution on Z-pinch characteristics

    Institute of Scientific and Technical Information of China (English)

    Duan Yao-Yong; Guo Yong-Hui; Wang Wen-Sheng; Qiu Ai-Ci

    2005-01-01

    A two-dimensional, three-temperature radiation magneto-hydrodynamics model is applied to the investigation of evolutional trends in x-ray radiation power, energy, peak plasma temperature and density as functions of drive current rise-time and initial load density distribution by using the typical experimental parameters of tungsten wire-array Z-pinch on the Qiangguang-Ⅰ generator. The numerical results show that as the drive current rise-time is shortened, x-ray radiation peak power, energy, peak plasma density and peak ion temperature increase approximately linearly, but among them the x-ray radiation peak power increases more quickly. As the initial plasma density distribution in the radial direction becomes gradually flattened, the peak radiation power and the peak ion-temperature almost exponentially increase, while the radiation energy and the peak plasma density change only a little. The main effect of shortening drive current rise-time is to enhance compression of plasma, and the effect of flattening initial load density distribution in the radial direction is to raise the plasma temperature. Both of the approaches elevate the x-ray peak radiation power.

  11. Transport profiles induced by radially localized modes in tokamak

    International Nuclear Information System (INIS)

    Beklemishev, A.D.; Horton, W.

    1991-04-01

    We describe a new approach to the calculation of turbulent transport coefficients for radially localized modes. The theory takes into account the nonuniformity of the distribution of rational (resonant) magnetic surfaces in minor radius. This distribution function is proportional to the density of available states of excitation. The resulting density of state correction qualitatively changes the radial profile of the transport coefficients, as compared to the usual local diffusivity formulae. The correction factor calculated for the η i -mode transport allows a much better agreement of χ i with the experimental data than previously achieved. 8 refs., 3 figs

  12. Development of tool for simulating the effect of radial electric fields on Ion-Temperature-Gradient modes in 3D configurations

    International Nuclear Information System (INIS)

    Eriksson, Lars

    2003-03-01

    The heat flux level observed in magnetic plasma confinement experiments such as tokamaks is much higher than what can be explained from neoclassical theory. There is a strong interest in the controlled nuclear fusion community to fully understand this phenomenon, called anomalous transport. One idea is that radial electric fields play a key role in the stabilization process of the electrostatic instabilities called micro instabilities that are considered responsible for the anomalous heat flux. This work studies the effect of a static ad-hoc radial electric field on microinstabilities, especially the ion temperature gradient (ITG) driven mode, within the frame of a global 3D gyrokinetic model. This will make it possible to extend the simulations done in tokamaks and helically symmetric systems to fully 313 magnetic configurations. Technically the work consists of extending the 3D gyrokinetic code Euterpe to also include the effect of the drifts induced by an imposed radial electrostatic potential. Simulations are performed in tokamak and helically symmetric configurations. The results indicate that this modified version of Euterpe can be used in studying more complex 3D fusion devices

  13. Modeling of radial gas fraction profiles for bubble flow in vertical pipes

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, D.; Krepper, E.; Prasser, H.-M. [Forschungszentrum Rossendorf e.V., Institute of Safety Research, Dresden (Germany)

    2001-07-01

    The paper presents a method for the prediction of radial gas fraction profiles from a given bubble size distribution. The method is based on the assumption of the equilibrium of the forces acting on a bubble perpendicularly to the flow direction. Assuming a large number of bubble size classes radial distributions are calculated separately for all bubble classes. The sum of these distributions is the radial profile of the gas fraction. The results of the model are compared with experimental data for a number of gas and liquid volume flow rates. The experiments were performed at a vertical test loop (inner diameter 50 mm) in FZ-Rossendorf using a wire mesh sensor. The sensor enables the determination of void distributions in the cross section of the loop. A special evaluation procedure supplies bubble size distributions as well as local distributions of bubbles within a predefined interval of bubble sizes. There is a good agreement between experimental and calculated data. In particular the change from wall peaking to core peaking is well predicted. (authors)

  14. Modeling of radial gas fraction profiles for bubble flow in vertical pipes

    International Nuclear Information System (INIS)

    Lucas, D.; Krepper, E.; Prasser, H.-M.

    2001-01-01

    The paper presents a method for the prediction of radial gas fraction profiles from a given bubble size distribution. The method is based on the assumption of the equilibrium of the forces acting on a bubble perpendicularly to the flow direction. Assuming a large number of bubble size classes radial distributions are calculated separately for all bubble classes. The sum of these distributions is the radial profile of the gas fraction. The results of the model are compared with experimental data for a number of gas and liquid volume flow rates. The experiments were performed at a vertical test loop (inner diameter 50 mm) in FZ-Rossendorf using a wire mesh sensor. The sensor enables the determination of void distributions in the cross section of the loop. A special evaluation procedure supplies bubble size distributions as well as local distributions of bubbles within a predefined interval of bubble sizes. There is a good agreement between experimental and calculated data. In particular the change from wall peaking to core peaking is well predicted. (authors)

  15. Introducing radiality constraints in capacitated location-routing problems

    Directory of Open Access Journals (Sweden)

    Eliana Mirledy Toro Ocampo

    2017-03-01

    Full Text Available In this paper, we introduce a unified mathematical formulation for the Capacitated Vehicle Routing Problem (CVRP and for the Capacitated Location Routing Problem (CLRP, adopting radiality constraints in order to guarantee valid routes and eliminate subtours. This idea is inspired by formulations already employed in electric power distribution networks, which requires a radial topology in its operation. The results show that the proposed formulation greatly improves the convergence of the solver.

  16. Radial optimization of a BWR fuel cell using genetic algorithms; Optimizacion radial de una celda de combustible BWR usando algoritmos geneticos

    Energy Technology Data Exchange (ETDEWEB)

    Martin del Campo M, C.; Carmona H, R.; Oropeza C, I.P. [UNAM, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)]. e-mail: cmcm@fi-b.unam.mx

    2006-07-01

    The development of the application of the Genetic Algorithms (GA) to the optimization of the radial distribution of enrichment in a cell of fuel of a BWR (Boiling Water Reactor) is presented. The optimization process it was ties to the HELIOS simulator, which is a transport code of neutron simulation of fuel cells that has been validated for the calculation of nuclear banks for BWRs. With heterogeneous radial designs can improve the radial distribution of the power, for what the radial design of fuel has a strong influence in the global design of fuel recharges. The optimum radial distribution of fuel bars is looked for with different enrichments of U{sup 235} and contents of consumable poison. For it is necessary to define the representation of the solution, the objective function and the implementation of the specific optimization process to the solution of the problem. The optimization process it was coded in 'C' language, it was automated the creation of the entrances to the simulator, the execution of the simulator and the extraction, in the exit of the simulator, of the parameters that intervene in the objective function. The objective function includes four parameters: average enrichment of the cell, average gadolinia concentration of the cell, peak factor of radial power and k-infinite multiplication factor. To be able to calculate the parameters that intervene in the objective function, the one evaluation process of GA was ties to the HELIOS code executed in a Compaq Alpha workstation. It was applied to the design of a fuel cell of 10 x 10 that it can be employee in the fuel assemble designs that are used at the moment in the Laguna Verde Nucleo electric Central. Its were considered 10 different fuel compositions which four contain gadolinia. Three heuristic rules that consist in prohibiting the placement of bars with gadolinia in the ends of the cell, to place the compositions with the smallest enrichment in the corners of the cell and to fix

  17. Sapphire-fiber-based distributed high-temperature sensing system.

    Science.gov (United States)

    Liu, Bo; Yu, Zhihao; Hill, Cary; Cheng, Yujie; Homa, Daniel; Pickrell, Gary; Wang, Anbo

    2016-09-15

    We present, for the first time to our knowledge, a sapphire-fiber-based distributed high-temperature sensing system based on a Raman distributed sensing technique. High peak power laser pulses at 532 nm were coupled into the sapphire fiber to generate the Raman signal. The returned Raman Stokes and anti-Stokes signals were measured in the time domain to determine the temperature distribution along the fiber. The sensor was demonstrated from room temperature up to 1200°C in which the average standard deviation is about 3.7°C and a spatial resolution of about 14 cm was achieved.

  18. Radial magnetic compression in the expelled jet of a plasma deflagration accelerator

    International Nuclear Information System (INIS)

    Loebner, Keith T. K.; Underwood, Thomas C.; Mouratidis, Theodore; Cappelli, Mark A.

    2016-01-01

    A spectroscopic study of a pulsed plasma deflagration accelerator is carried out that confirms the existence of a strong compression in the emerging jet at the exit plane of the device. An imaging spectrometer is used to collect broadened Hα emission from a transaxial slice of the emerging jet at high spatial resolution, and the radial plasma density profile is computed from Voigt fits of the Abel inverted emissivity profiles. The plasma temperature, determined via Doppler broadening of impurity line emission, is compared against the temperature predictions of a radial magnetohydrodynamic equilibrium model applied to the measured density profiles. Empirical scaling laws developed for the plasma density, combined with the measured and predicted temperatures, indicate that a radially equilibrated Z-pinch is formed within the expelled plasma jet at the exit plane during the deflagration process.

  19. Analytical method for determining the channel-temperature distribution

    International Nuclear Information System (INIS)

    Kurbatov, I.M.

    1992-01-01

    The distribution of the predicted temperature over the volume or cross section of the active zone is important for thermal calculations of reactors taking into account random deviations. This requires a laborious calculation which includes the following steps: separation of the nominal temperature field, within the temperature range, into intervals, in each of which the temperature is set equal to its average value in the interval; determination of the number of channels whose temperature falls within each interval; construction of the channel-temperature distribution in each interval in accordance with the weighted error function; and summation of the number of channels with the same temperature over all intervals. This procedure can be greatly simplified with the help of methods which eliminate numerous variant calculations when the nominal temperature field is open-quotes refinedclose quotes up to the optimal field according to different criteria. In the present paper a universal analytical method is proposed for determining, by changing the coefficients in the channel-temperature distribution function, the form of this function that reflects all conditions of operation of the elements in the active zone. The problem is solved for the temperature of the coolant at the outlet from the reactor channels

  20. Evaluation of temperature distribution in a containment vessel during operation

    International Nuclear Information System (INIS)

    Utanohara, Yoichi; Murase, Michio; Yanagi, Chihiro; Masui, Akihiro; Inomata, Ryo; Kamiya, Yuji

    2012-01-01

    For safety analysis of the containment vessel (CV) in a nuclear power plant, the average temperature of the gas phase in the CV during operation is used as an initial condition. An actual CV, however, has a temperature distribution, which makes the estimation of the average temperature difficult. Numerical simulation seems to be useful for the average temperature estimation, but it has several difficulties such as predictions of temperature distribution in a large and closed space that has several compartments, and modeling the heat generating components and the convection-diffusion of heat by ventilation air-conditioning systems. The main purpose of this study was to simulate the temperature distribution and evaluate the average temperature in the CV of a three-loop pressurized water reactor (PWR) during the reactor operation. The simulation considered the heat generation of equipment, flow due to the ventilation and air conditioning systems, heat loss to the CV exterior, and the solar heat. The predicted temperature distribution was significantly affected by the flow. Particularly, openings, which became flow paths, affected the temperature distribution. The temperature increased with a rise in height within the CV and the flow field seemed to transform from forced convection to natural convection. The volume-averaged temperature was different between gas and solid (concrete, CV wall) phases as well as between heights. The total volume-averaged temperature of the CV was nearly equal to the average gas phase temperature. It was found to be easy to evaluate the effect of openings on the temperature distribution and estimate the average temperature in CV by numerical simulation. (author)

  1. Radially localized measurements of superthermal electrons using oblique electron cyclotron emission

    International Nuclear Information System (INIS)

    Preische, S.; Efthimion, P.C.; Kaye, S.M.

    1996-05-01

    It is shown that radial localization of optically tin Electron Cyclotron Emission from superthermal electrons can be imposed by observation of emission upshifted from the thermal cyclotron resonance in the horizontal midplane of a tokamak. A new and unique diagnostic has been proposed and operated to make radially localized measurements of superthermal electrons during Lower Hybrid Current Drive on the PBX-M tokamak. The superthermal electron density profile as well as moments of the electron energy distribution as a function of radius are measured during Lower Hybrid Current Drive. The time evolution of these measurements after the Lower Hybrid power is turned off are given and the observed behavior reflects the collisional isotropization of the energy distribution and radial diffusion of the spatial profile

  2. A Novel Integrated Structure with a Radial Displacement Sensor and a Permanent Magnet Biased Radial Magnetic Bearing

    Directory of Open Access Journals (Sweden)

    Jinji Sun

    2014-01-01

    Full Text Available In this paper, a novel integrated structure is proposed in order to reduce the axial length of the high speed of a magnetically suspended motor (HSMSM to ensure the maximum speed, which combines radial displacement sensor probes and the permanent magnet biased radial magnetic bearing in HSMSM. The sensor probes are integrated in the magnetic bearing, and the sensor preamplifiers are placed in the control system of the HSMSM, separate from the sensor probes. The proposed integrated structure can save space in HSMSMs, improve the working frequency, reduce the influence of temperature on the sensor circuit, and improve the stability of HSMSMs.

  3. Measurements of electron density and temperature profiles in a gas blanket experiment

    International Nuclear Information System (INIS)

    Kuthy, A.

    1979-02-01

    Radial profiles of electron density, temperature and H sub(β) intensity are presented for the rotating plasma device F-1. The hydrogen filling pressure, the average magnetic field strength at the midplane, and the power input to the discharge have been varied in the ranges 10-100 mTorr, 0.25-0.5 Tesla, and 0.1 to 1.5 MW, respectively. These experiments have been performed with the main purpose of studying the gas blanket (cold-mantle) state of the plasma. It is shown, that a simple spectroscopic method can be used to derive the radial distribution of the electron temperature in such plasmas. The observed peak temperatures and densities are in agreement with earlier theoretical estimates. (author)

  4. A fuzzy genetic approach for network reconfiguration to enhance voltage stability in radial distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, N.C. [Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, 75450 Melaka (Malaysia); Prasad, K. [Faculty of Information Science and Technology, Multimedia University, Jalan Ayer Keroh Lama, Bukit Beruang, 75450 Melaka (Malaysia)

    2006-11-15

    This paper presents a fuzzy genetic approach for reconfiguration of radial distribution systems (RDS) so as to maximize the voltage stability of the network for a specific set of loads. The network reconfiguration involves a mechanism for selection of the best set of branches to be opened, one from each loop, such that the reconfigured RDS possesses desired performance characteristics. This discrete solution space is better handled by the proposed scheme, which maximizes a suitable optimizing function (computed using two different approaches). In the first approach, this function is chosen as the average of a voltage stability index of all the buses in the RDS, while in the second approach, the complete RDS is reduced to a two bus equivalent system and the optimizing function is the voltage stability index of this reduced two bus system. The fuzzy genetic algorithm uses a suitable coding and decoding scheme for maintaining the radial nature of the network at every stage of genetic evolution, and it also uses a fuzzy rule based mutation controller for efficient search of the solution space. This method, tested on 69 bus and 33 bus RDSs, shows promising results for the both approaches. It is also observed that the network losses are reduced when the voltage stability is enhanced by the network reconfiguration. (author)

  5. The radial distribution of the neutron field in the core of the Dalat Nuclear Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Huy, Ngo Quang [Centre for Nuclear Technique Application, Ho Chi Minh City (Viet Nam); Thong, Ha Van; Long, Vu Hai; Khang, Ngo Phu; Binh, Nguyen Duc; Tuan, Nguyen Minh; Vinh, Le Vinh [Nuclear Research Inst., Da Lat (Viet Nam)

    1994-10-01

    Determination of the radial distribution of the thermal neutron field in the core of the Dalat reactor is done by the Cu foil activation method. The measured data are fitted by the least square method to determine several physical parameters of the reactor, as follows: 1. Buckling B{sub r}{sup 2}=(84.6{+-}5.5)10{sup -4}/cm{sup 2}. 2. The effective radius R{sub eff}=(27.6{+-}1.0)cm. 3. The extrapolation distance {lambda}=(8.7{+-}1.0)cm. 4. The unequal coefficient of the effective multiplication K{sub r}=1.77{+-}0.11. (author). 2 refs., 4 figs., 1 tab.

  6. Effects of applied dc radial electric fields on particle transport in a bumpy torus plasma

    Science.gov (United States)

    Roth, J. R.

    1978-01-01

    The influence of applied dc radial electric fields on particle transport in a bumpy torus plasma is studied. The plasma, magnetic field, and ion heating mechanism are operated in steady state. Ion kinetic temperature is more than a factor of ten higher than electron temperature. The electric fields raise the ions to energies on the order of kilovolts and then point radially inward or outward. Plasma number density profiles are flat or triangular across the plasma diameter. It is suggested that the radial transport processes are nondiffusional and dominated by strong radial electric fields. These characteristics are caused by the absence of a second derivative in the density profile and the flat electron temperature profiles. If the electric field acting on the minor radius of the toroidal plasma points inward, plasma number density and confinement time are increased.

  7. Transitionless Enhanced Confinement and the Role of Radial Electric Field Shear

    International Nuclear Information System (INIS)

    Coppi, B.; Ernst, D.R.; Bell, M.G.; Bell, R.E.; Budny, R.V.

    1999-01-01

    Evidence for the role of radial electric field shear in enhanced confinement regimes attained without sharp bifurcations or transitions is presented. Temperature scans at constant density, created in the reheat phase following deuterium pellet injection into supershot plasmas in the Tokamak Fusion Test Reactor [J.D. Strachan, et al., Phys. Rev. Lett. 58 (1987) 1004] are simulated using a first-principles transport model. The slow reheat of the ion temperature profile, during which the temperature nearly doubles, is not explained by relatively comprehensive models of transport due to Ion Temperature Gradient Driven Turbulence (ITGDT), which depends primarily on the (unchanging) electron density gradient. An extended model, including the suppression of toroidal ITGDT by self-consistent radial electric field shear, does reproduce the reheat phase

  8. Radial Field Piezoelectric Diaphragms

    Science.gov (United States)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  9. Investigations of the radial distributions of nucleons in 1fsub(7/2)-shell nuclei by elastic alpha particle scattering

    International Nuclear Information System (INIS)

    Gils, H.J.

    1984-12-01

    The radial size and shape of the distribution of nucleons - i.e. the sum of protons and neutrons - in atomic nuclei of the 1fsub(7/2) shell is investigated in the present work. The experimental basis of the studies are differential cross sections of elastic α particle scattering by sup(40,42,43,44,48)Ca, 50 Ti, 51 V, 52 Cr precisely measured over a wide angular range at the 104 MeV α particle beam from the Karlsruhe Isochronous Cyclotron. The experimental cross sections are analyzed using so-called 'model independent' optical potentials by which the data are very well reproduced. The error bands of these potentials are determined in a well-defined form from the analyses. The high sensitivity of the data to the radial form of the real optical potential justifies, in principle, that the experiments are a suitable tool for investigating nuclear density distributions. Some pre-informations on this question are obtained from the optical potential analyses. For a more direct access to the nuclear matter distributions - in particular to differences between neighbouring nuclei - a semimicroscopic reaction model is presented which on the one hand is based on a fully microscopic many body approach. On the other hand all quantities being not of particular interest for the results are treated in a phenomenological way. Thereby, it is possible to reproduce the experimental cross sections as well as by the 'model independent' potentials and to obtain full consistency between the two approaches. This has not been achieved by any other microscopic reaction model. (orig./HSI) [de

  10. Dual reference point temperature interrogating method for distributed temperature sensor

    International Nuclear Information System (INIS)

    Ma, Xin; Ju, Fang; Chang, Jun; Wang, Weijie; Wang, Zongliang

    2013-01-01

    A novel method based on dual temperature reference points is presented to interrogate the temperature in a distributed temperature sensing (DTS) system. This new method is suitable to overcome deficiencies due to the impact of DC offsets and the gain difference in the two signal channels of the sensing system during temperature interrogation. Moreover, this method can in most cases avoid the need to calibrate the gain and DC offsets in the receiver, data acquisition and conversion. An improved temperature interrogation formula is presented and the experimental results show that this method can efficiently estimate the channel amplification and system DC offset, thus improving the system accuracy. (letter)

  11. Transport in Silicon Nanowires: Role of Radial Dopant Profile

    DEFF Research Database (Denmark)

    Markussen, Troels; Rurali, Riccardo; Jauho, Antti-Pekka

    2008-01-01

    distributions of P dopant impurities. We find that the radial distribution of the dopants influences the conductance properties significantly: surface doped wires have longer mean-free paths and smaller sample-to-sample fluctuations in the cross-over from ballistic to diffusive transport. These findings can...

  12. Axial- and radial-resolved electron density and excitation temperature of aluminum plasma induced by nanosecond laser: Effect of the ambient gas composition and pressure

    Directory of Open Access Journals (Sweden)

    Mahmoud S. Dawood

    2015-11-01

    Full Text Available The spatial variation of the characteristics of an aluminum plasma induced by a pulsed nanosecond XeCl laser is studied in this paper. The electron density and the excitation temperature are deduced from time- and space- resolved Stark broadening of an ion line and from a Boltzmann diagram, respectively. The influence of the gas pressure (from vacuum up to atmospheric pressure and compositions (argon, nitrogen and helium on these characteristics is investigated. It is observed that the highest electron density occurs near the laser spot and decreases by moving away both from the target surface and from the plume center to its edge. The electron density increases with the gas pressure, the highest values being occurred at atmospheric pressure when the ambient gas has the highest mass, i.e. in argon. The excitation temperature is determined from the Boltzmann plot of line intensities of iron impurities present in the aluminum target. The highest temperature is observed close to the laser spot location for argon at atmospheric pressure. It decreases by moving away from the target surface in the axial direction. However, no significant variation of temperature occurs along the radial direction. The differences observed between the axial and radial direction are mainly due to the different plasma kinetics in both directions.

  13. Plasma Signatures of Radial Field Power Dropouts

    International Nuclear Information System (INIS)

    Lucek, E.A.; Horbury, T.S.; Balogh, A.; McComas, D.J.

    1998-01-01

    A class of small scale structures, with a near-radial magnetic field and a drop in magnetic field fluctuation power, have recently been identified in the polar solar wind. An earlier study of 24 events, each lasting for 6 hours or more, identified no clear plasma signature. In an extension of that work, radial intervals lasting for 4 hours or more (89 in total), have been used to search for a statistically significant plasma signature. It was found that, despite considerable variations between intervals, there was a small but significant drop, on average, in plasma temperature, density and β during these events

  14. Exploring functionally related enzymes using radially distributed properties of active sites around the reacting points of bound ligands

    Directory of Open Access Journals (Sweden)

    Ueno Keisuke

    2012-04-01

    Full Text Available Abstract Background Structural genomics approaches, particularly those solving the 3D structures of many proteins with unknown functions, have increased the desire for structure-based function predictions. However, prediction of enzyme function is difficult because one member of a superfamily may catalyze a different reaction than other members, whereas members of different superfamilies can catalyze the same reaction. In addition, conformational changes, mutations or the absence of a particular catalytic residue can prevent inference of the mechanism by which catalytic residues stabilize and promote the elementary reaction. A major hurdle for alignment-based methods for prediction of function is the absence (despite its importance of a measure of similarity of the physicochemical properties of catalytic sites. To solve this problem, the physicochemical features radially distributed around catalytic sites should be considered in addition to structural and sequence similarities. Results We showed that radial distribution functions (RDFs, which are associated with the local structural and physicochemical properties of catalytic active sites, are capable of clustering oxidoreductases and transferases by function. The catalytic sites of these enzymes were also characterized using the RDFs. The RDFs provided a measure of the similarity among the catalytic sites, detecting conformational changes caused by mutation of catalytic residues. Furthermore, the RDFs reinforced the classification of enzyme functions based on conventional sequence and structural alignments. Conclusions Our results demonstrate that the application of RDFs provides advantages in the functional classification of enzymes by providing information about catalytic sites.

  15. Effect of ion orbit loss on the structure in the H-mode tokamak edge pedestal profiles of rotation velocity, radial electric field, density, and temperature

    International Nuclear Information System (INIS)

    Stacey, Weston M.

    2013-01-01

    An investigation of the effect of ion orbit loss of thermal ions and the compensating return ion current directly on the radial ion flux flowing in the plasma, and thereby indirectly on the toroidal and poloidal rotation velocity profiles, the radial electric field, density, and temperature profiles, and the interpretation of diffusive and non-diffusive transport coefficients in the plasma edge, is described. Illustrative calculations for a high-confinement H-mode DIII-D [J. Luxon, Nucl. Fusion 42, 614 (2002)] plasma are presented and compared with experimental results. Taking into account, ion orbit loss of thermal ions and the compensating return ion current is found to have a significant effect on the structure of the radial profiles of these quantities in the edge plasma, indicating the necessity of taking ion orbit loss effects into account in interpreting or predicting these quantities

  16. Temperature and flow distribution in planar SOFC stacks

    Directory of Open Access Journals (Sweden)

    Monica Østenstad

    1995-07-01

    Full Text Available Simulation of a planar Solid Oxide Fuel Cell stack requires the solution of the mass balances of the chemical species, the energy balances, the charge balance and the channel flow equations in order to compute the species concentrations, the temperature distributions, the current density and the channel flows. The unit cell geometry can be taken into account by combining detailed modeling of a unit cell with a homogenized model of a whole stack. In this study the effect of the asymmetric temperature distribution on the channel flows in a conventional cross-flow design has been investigated. The bidirectional cross-flow design is introduced, for which we can show more directional temperature and flow distributions.

  17. Measuring brightness temperature distributions of plasma bunches

    International Nuclear Information System (INIS)

    Kirko, V.I.; Stadnichenko, I.A.

    1981-01-01

    The possibility of restoration of brightness temperature distribution along plasma jet on the base of a simple ultra high- speed photography and subsequent photometric treatment is shown. The developed technique has been applied for finding spectral radiation intensity and brightness temperature of plasma jets of a tubular gas-cumulative charge and explosive plasma compressor. The problem of shock wave front has been successfully solved and thus distribution of above parameters beginning from the region preceeding the shock wave has been obtained [ru

  18. Bessel-like beams modulated by arbitrary radial functions

    Science.gov (United States)

    Herman; Wiggins

    2000-06-01

    An approximate method for determining the radial and axial intensity of a Bessel-like beam is presented for the general case in which a radial Bessel distribution of any order is modulated by an arbitrary function. For Bessel-Gauss, generalized Bessel-Gauss, and Bessel-super-Gauss beams, this simple approximation yields results that are very close to the exact values, while they are exact for Bessel beams. A practical beam that can be generated with a combination of simple lenses is also analyzed and illustrated.

  19. A temperature-sensitive allele of a putative mRNA splicing helicase down-regulates many cell wall genes and causes radial swelling in Arabidopsis thaliana.

    Science.gov (United States)

    Howles, Paul A; Gebbie, Leigh K; Collings, David A; Varsani, Arvind; Broad, Ronan C; Ohms, Stephen; Birch, Rosemary J; Cork, Ann H; Arioli, Tony; Williamson, Richard E

    2016-05-01

    The putative RNA helicase encoded by the Arabidopsis gene At1g32490 is a homolog of the yeast splicing RNA helicases Prp2 and Prp22. We isolated a temperature-sensitive allele (rsw12) of the gene in a screen for root radial swelling mutants. Plants containing this allele grown at the restrictive temperature showed weak radial swelling, were stunted with reduced root elongation, and contained reduced levels of cellulose. The role of the protein was further explored by microarray analysis. By using both fold change cutoffs and a weighted gene coexpression network analysis (WGCNA) to investigate coexpression of genes, we found that the radial swelling phenotype was not linked to genes usually associated with primary cell wall biosynthesis. Instead, the mutation has strong effects on expression of secondary cell wall related genes. Many genes potentially associated with secondary walls were present in the most significant WGCNA module, as were genes coding for arabinogalactans and proteins with GPI anchors. The proportion of up-regulated genes that possess introns in rsw12 was above that expected if splicing was unrelated to the activity of the RNA helicase, suggesting that the helicase does indeed play a role in splicing in Arabidopsis. The phenotype may be due to a change in the expression of one or more genes coding for cell wall proteins.

  20. Improving the spectral measurement accuracy based on temperature distribution and spectra-temperature relationship

    Science.gov (United States)

    Li, Zhe; Feng, Jinchao; Liu, Pengyu; Sun, Zhonghua; Li, Gang; Jia, Kebin

    2018-05-01

    Temperature is usually considered as a fluctuation in near-infrared spectral measurement. Chemometric methods were extensively studied to correct the effect of temperature variations. However, temperature can be considered as a constructive parameter that provides detailed chemical information when systematically changed during the measurement. Our group has researched the relationship between temperature-induced spectral variation (TSVC) and normalized squared temperature. In this study, we focused on the influence of temperature distribution in calibration set. Multi-temperature calibration set selection (MTCS) method was proposed to improve the prediction accuracy by considering the temperature distribution of calibration samples. Furthermore, double-temperature calibration set selection (DTCS) method was proposed based on MTCS method and the relationship between TSVC and normalized squared temperature. We compare the prediction performance of PLS models based on random sampling method and proposed methods. The results from experimental studies showed that the prediction performance was improved by using proposed methods. Therefore, MTCS method and DTCS method will be the alternative methods to improve prediction accuracy in near-infrared spectral measurement.

  1. Visualizing Stress and Temperature Distribution During Elevated Temperature Deformation of IN-617 Using Nanomechanical Raman Spectroscopy

    Science.gov (United States)

    Zhang, Yang; Wang, Hao; Tomar, Vikas

    2018-04-01

    This work presents direct measurements of stress and temperature distribution during the mesoscale microstructural deformation of Inconel-617 (IN-617) during 3-point bending tests as a function of temperature. A novel nanomechanical Raman spectroscopy (NMRS)-based measurement platform was designed for simultaneous in situ temperature and stress mapping as a function of microstructure during deformation. The temperature distribution was found to be directly correlated to stress distribution for the analyzed microstructures. Stress concentration locations are shown to be directly related to higher heat conduction and result in microstructural hot spots with significant local temperature variation.

  2. Radial nerve dysfunction

    Science.gov (United States)

    Neuropathy - radial nerve; Radial nerve palsy; Mononeuropathy ... Damage to one nerve group, such as the radial nerve, is called mononeuropathy . Mononeuropathy means there is damage to a single nerve. Both ...

  3. A model for radial cesium transport in a fuel pellet

    International Nuclear Information System (INIS)

    Imoto, Shosuke

    1989-01-01

    In order to explain the radial redistribution of cesium in an irradiated pellet, a two-step release model is proposed. The first step involves the migration of cesium by atomic diffusion to some channels, such as grain boundaries and cracks, and the second step assumes a thermomigration down along the temperature gradient. Distribution profiles of cesium are obtained by numerical calculation with the present model assuming a constant and spatially uniform birth rate of cesium in the pellet. The result agrees well with the profile observed by micro-gamma scanning for the LWR fuel in the outer region of the pellet but diverges from it at the inner region. Discussion is made on the steady-state model hitherto generally utilized. (orig.)

  4. Influence of topography on landscape radiation temperature distribution

    International Nuclear Information System (INIS)

    Florinsky, I.V.; Kulagina, T.B.; Meshalkina, J.L.

    1994-01-01

    The evaluation of the influence of topography on landscape radiation temperature distribution is carried out by statistical processing of digital models of elevation, gradient, aspect, horizontal, vertical and mean land surface curvatures and the infrared thermal scene generated by the Thermovision 880 system. Significant linear correlation coefficients between the landscape radiation temperature and elevation, slope, aspect, vertical and mean landsurface curvatures are determined, being —0-57, 0 38, 0-26, 015, 013, respectively. The equation of the topography influence on the distribution of the landscape radiation temperature is defined. (author)

  5. Inverse analysis of non-uniform temperature distributions using multispectral pyrometry

    Science.gov (United States)

    Fu, Tairan; Duan, Minghao; Tian, Jibin; Shi, Congling

    2016-05-01

    Optical diagnostics can be used to obtain sub-pixel temperature information in remote sensing. A multispectral pyrometry method was developed using multiple spectral radiation intensities to deduce the temperature area distribution in the measurement region. The method transforms a spot multispectral pyrometer with a fixed field of view into a pyrometer with enhanced spatial resolution that can give sub-pixel temperature information from a "one pixel" measurement region. A temperature area fraction function was defined to represent the spatial temperature distribution in the measurement region. The method is illustrated by simulations of a multispectral pyrometer with a spectral range of 8.0-13.0 μm measuring a non-isothermal region with a temperature range of 500-800 K in the spot pyrometer field of view. The inverse algorithm for the sub-pixel temperature distribution (temperature area fractions) in the "one pixel" verifies this multispectral pyrometry method. The results show that an improved Levenberg-Marquardt algorithm is effective for this ill-posed inverse problem with relative errors in the temperature area fractions of (-3%, 3%) for most of the temperatures. The analysis provides a valuable reference for the use of spot multispectral pyrometers for sub-pixel temperature distributions in remote sensing measurements.

  6. Water structure as a function of temperature from X-ray scatteringexperiments and ab initio molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hura, Greg; Russo, Daniela; Glaeser, Robert M.; Head-Gordon,Teresa; Krack, Matthias; Parrinello, Michele

    2003-03-01

    We present high-quality X-ray scattering experiments on pure water taken over a temperature range of 2 to 77 C using a synchrotron beam line at the advanced light source (ALS) at Lawrence Berkeley National Laboratory. The ALS X-ray scattering intensities are qualitatively different in trend of maximum intensity over this temperature range compared to older X-ray experiments. While the common procedure is to report both the intensity curve and radial distribution function(s), the proper extraction of the real-space pair correlation functions from the experimental scattering is very difficult due to uncertainty introduced in the experimental corrections, the proper weighting of OO, OH, and HH contributions, and numerical problems of Fourier transforming truncated data in Q-space. Instead, we consider the direct calculation of X-ray scattering spectra using electron densities derived from density functional theory based on real-space configurations generated with classical water models. The simulation of the experimental intensity is therefore definitive for determining radial distribution functions over a smaller Q-range. We find that the TIP4P, TIP5P and polarizable TIP4P-Pol2 water models, with DFT-LDA densities, show very good agreement with the experimental intensities, and TIP4P-Pol2 in particular shows quantitative agreement over the full temperature range. The resulting radial distribution functions from TIP4P-Pol2 provide the current best benchmarks for real-space water structure over the biologically relevant temperature range studied here.

  7. Calculation of the radial and axial flux and power distribution for a CANDU 6 reactor with both the MCNP6 and Serpent codes

    International Nuclear Information System (INIS)

    Hussein, M.S.; Bonin, H.W.; Lewis, B.J.

    2014-01-01

    The most recent versions of the Monte Carlo-based probabilistic transport code MCNP6 and the continuous energy reactor physics burnup calculation code Serpent allow for a 3-D geometry calculation accounting for the detailed geometry without unit-cell homogenization. These two codes are used to calculate the axial and radial flux and power distributions for a CANDU6 GENTILLY-2 nuclear reactor core with 37-element fuel bundles. The multiplication factor, actual flux distribution and power density distribution were calculated by using a tally combination for MCNP6 and detector analysis for Serpent. Excellent agreement was found in the calculated flux and power distribution. The Serpent code is most efficient in terms of the computational time. (author)

  8. Calculation of the radial and axial flux and power distribution for a CANDU 6 reactor with both the MCNP6 and Serpent codes

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, M.S.; Bonin, H.W., E-mail: mohamed.hussein@rmc.ca, E-mail: bonin-h@rmc.ca [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, ON (Canada); Lewis, B.J., E-mail: Brent.Lewis@uoit.ca [Univ. of Ontario Inst. of Tech., Faculty of Energy Systems and Nuclear Science, Oshawa, ON (Canada)

    2014-07-01

    The most recent versions of the Monte Carlo-based probabilistic transport code MCNP6 and the continuous energy reactor physics burnup calculation code Serpent allow for a 3-D geometry calculation accounting for the detailed geometry without unit-cell homogenization. These two codes are used to calculate the axial and radial flux and power distributions for a CANDU6 GENTILLY-2 nuclear reactor core with 37-element fuel bundles. The multiplication factor, actual flux distribution and power density distribution were calculated by using a tally combination for MCNP6 and detector analysis for Serpent. Excellent agreement was found in the calculated flux and power distribution. The Serpent code is most efficient in terms of the computational time. (author)

  9. A study of self organized criticality in ion temperature gradient mode driven gyrokinetic turbulence

    Science.gov (United States)

    Mavridis, M.; Isliker, H.; Vlahos, L.; Görler, T.; Jenko, F.; Told, D.

    2014-10-01

    An investigation on the characteristics of self organized criticality (Soc) in ITG mode driven turbulence is made, with the use of various statistical tools (histograms, power spectra, Hurst exponents estimated with the rescaled range analysis, and the structure function method). For this purpose, local non-linear gyrokinetic simulations of the cyclone base case scenario are performed with the GENE software package. Although most authors concentrate on global simulations, which seem to be a better choice for such an investigation, we use local simulations in an attempt to study the locally underlying mechanisms of Soc. We also study the structural properties of radially extended structures, with several tools (fractal dimension estimate, cluster analysis, and two dimensional autocorrelation function), in order to explore whether they can be characterized as avalanches. We find that, for large enough driving temperature gradients, the local simulations exhibit most of the features of Soc, with the exception of the probability distribution of observables, which show a tail, yet they are not of power-law form. The radial structures have the same radial extent at all temperature gradients examined; radial motion (transport) though appears only at large temperature gradients, in which case the radial structures can be interpreted as avalanches.

  10. A study of self organized criticality in ion temperature gradient mode driven gyrokinetic turbulence

    International Nuclear Information System (INIS)

    Mavridis, M.; Isliker, H.; Vlahos, L.; Görler, T.; Jenko, F.; Told, D.

    2014-01-01

    An investigation on the characteristics of self organized criticality (Soc) in ITG mode driven turbulence is made, with the use of various statistical tools (histograms, power spectra, Hurst exponents estimated with the rescaled range analysis, and the structure function method). For this purpose, local non-linear gyrokinetic simulations of the cyclone base case scenario are performed with the GENE software package. Although most authors concentrate on global simulations, which seem to be a better choice for such an investigation, we use local simulations in an attempt to study the locally underlying mechanisms of Soc. We also study the structural properties of radially extended structures, with several tools (fractal dimension estimate, cluster analysis, and two dimensional autocorrelation function), in order to explore whether they can be characterized as avalanches. We find that, for large enough driving temperature gradients, the local simulations exhibit most of the features of Soc, with the exception of the probability distribution of observables, which show a tail, yet they are not of power-law form. The radial structures have the same radial extent at all temperature gradients examined; radial motion (transport) though appears only at large temperature gradients, in which case the radial structures can be interpreted as avalanches

  11. A study of self organized criticality in ion temperature gradient mode driven gyrokinetic turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Mavridis, M.; Isliker, H.; Vlahos, L. [Section of Astrophysics, Astronomy and Mechanics, Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Görler, T.; Jenko, F.; Told, D. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany)

    2014-10-15

    An investigation on the characteristics of self organized criticality (Soc) in ITG mode driven turbulence is made, with the use of various statistical tools (histograms, power spectra, Hurst exponents estimated with the rescaled range analysis, and the structure function method). For this purpose, local non-linear gyrokinetic simulations of the cyclone base case scenario are performed with the GENE software package. Although most authors concentrate on global simulations, which seem to be a better choice for such an investigation, we use local simulations in an attempt to study the locally underlying mechanisms of Soc. We also study the structural properties of radially extended structures, with several tools (fractal dimension estimate, cluster analysis, and two dimensional autocorrelation function), in order to explore whether they can be characterized as avalanches. We find that, for large enough driving temperature gradients, the local simulations exhibit most of the features of Soc, with the exception of the probability distribution of observables, which show a tail, yet they are not of power-law form. The radial structures have the same radial extent at all temperature gradients examined; radial motion (transport) though appears only at large temperature gradients, in which case the radial structures can be interpreted as avalanches.

  12. Time dependent temperature distribution in pulsed Ti:sapphire lasers

    Science.gov (United States)

    Buoncristiani, A. Martin; Byvik, Charles E.; Farrukh, Usamah O.

    1988-01-01

    An expression is derived for the time dependent temperature distribution in a finite solid state laser rod for an end-pumped beam of arbitrary shape. The specific case of end pumping by circular (constant) or Gaussian beam is described. The temperature profile for a single pump pulse and for repetitive pulse operation is discussed. The particular case of the temperature distribution in a pulsed titanium:sapphire rod is considered.

  13. Soil Temperature Variability in Complex Terrain measured using Distributed a Fiber-Optic Distributed Temperature Sensing

    Science.gov (United States)

    Seyfried, M. S.; Link, T. E.

    2013-12-01

    Soil temperature (Ts) exerts critical environmental controls on hydrologic and biogeochemical processes. Rates of carbon cycling, mineral weathering, infiltration and snow melt are all influenced by Ts. Although broadly reflective of the climate, Ts is sensitive to local variations in cover (vegetative, litter, snow), topography (slope, aspect, position), and soil properties (texture, water content), resulting in a spatially and temporally complex distribution of Ts across the landscape. Understanding and quantifying the processes controlled by Ts requires an understanding of that distribution. Relatively few spatially distributed field Ts data exist, partly because traditional Ts data are point measurements. A relatively new technology, fiber optic distributed temperature system (FO-DTS), has the potential to provide such data but has not been rigorously evaluated in the context of remote, long term field research. We installed FO-DTS in a small experimental watershed in the Reynolds Creek Experimental Watershed (RCEW) in the Owyhee Mountains of SW Idaho. The watershed is characterized by complex terrain and a seasonal snow cover. Our objectives are to: (i) evaluate the applicability of fiber optic DTS to remote field environments and (ii) to describe the spatial and temporal variability of soil temperature in complex terrain influenced by a variable snow cover. We installed fiber optic cable at a depth of 10 cm in contrasting snow accumulation and topographic environments and monitored temperature along 750 m with DTS. We found that the DTS can provide accurate Ts data (+/- .4°C) that resolves Ts changes of about 0.03°C at a spatial scale of 1 m with occasional calibration under conditions with an ambient temperature range of 50°C. We note that there are site-specific limitations related cable installation and destruction by local fauna. The FO-DTS provide unique insight into the spatial and temporal variability of Ts in a landscape. We found strong seasonal

  14. Radial head button holing: a cause of irreducible anterior radial head dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Su-Mi; Chai, Jee Won; You, Ja Yeon; Park, Jina [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Bae, Kee Jeong [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Orthopedic Surgery, Seoul (Korea, Republic of)

    2016-10-15

    ''Buttonholing'' of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction. (orig.)

  15. Measurements of radial profiles of ion cyclotron resonance heating on the tandem mirror experiment

    International Nuclear Information System (INIS)

    Falabella, S.

    1988-01-01

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawrence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). This analyzer indicates an increase in ion temperature from ∼20 eV before ICRH to ∼150 eV during ICRH, with ∼60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial integral of n i T i as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma potential is seen to vary from axially peaked, to nearly flat, as the plasma conditions varied over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U

  16. When Disorder Looks Like Order: A New Model to Explain Radial Magnetic Fields in Young Supernova Remnants

    Energy Technology Data Exchange (ETDEWEB)

    West, J. L.; Gaensler, B. M. [Dunlap Institute for Astronomy and Astrophysics University of Toronto, Toronto, ON M5S 3H4 (Canada); Jaffe, T. [CRESST, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ferrand, G. [RIKEN, Astrophysical Big Bang Laboratory, Wako, Saitama-ken (Japan); Safi-Harb, S., E-mail: jennifer.west@dunlap.utoronto.ca [Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2 (Canada)

    2017-11-10

    Radial magnetic fields are observed in all known young, shell-type supernova remnants in our Galaxy, including Cas A, Tycho, Kepler, and SN1006, and yet the nature of these radial fields has not been thoroughly explored. Using a 3D model, we consider the existence and observational implications of an intrinsically radial field. We also present a new explanation of the origin of the radial pattern observed from polarization data as resulting from a selection effect due to the distribution of cosmic-ray electrons (CREs). We show that quasi-parallel acceleration can concentrate CREs at regions where the magnetic field is radial, making a completely turbulent field appear ordered, when it is in fact disordered. We discuss observational properties that may help distinguish between an intrinsically radial magnetic field and the case where it only appears radial due to the CRE distribution. We also show that the case of an intrinsically radial field with a quasi-perpendicular CRE acceleration mechanism has intriguing similarities to the observed polarization properties of SN1006.

  17. When Disorder Looks Like Order: A New Model to Explain Radial Magnetic Fields in Young Supernova Remnants

    Science.gov (United States)

    West, J. L.; Jaffe, T.; Ferrand, G.; Safi-Harb, S.; Gaensler, B. M.

    2017-11-01

    Radial magnetic fields are observed in all known young, shell-type supernova remnants in our Galaxy, including Cas A, Tycho, Kepler, and SN1006, and yet the nature of these radial fields has not been thoroughly explored. Using a 3D model, we consider the existence and observational implications of an intrinsically radial field. We also present a new explanation of the origin of the radial pattern observed from polarization data as resulting from a selection effect due to the distribution of cosmic-ray electrons (CREs). We show that quasi-parallel acceleration can concentrate CREs at regions where the magnetic field is radial, making a completely turbulent field appear ordered, when it is in fact disordered. We discuss observational properties that may help distinguish between an intrinsically radial magnetic field and the case where it only appears radial due to the CRE distribution. We also show that the case of an intrinsically radial field with a quasi-perpendicular CRE acceleration mechanism has intriguing similarities to the observed polarization properties of SN1006.

  18. [Responses of Pinus sylvestris var. mongolica radial growth to climate warming in Great Xing' an Mountins: a case study in Mangui].

    Science.gov (United States)

    Zhang, Xing-Liang; He, Xing-Yuan; Chen, Zhen-Ju; Cui, Ming-Xing; Li, Na

    2011-12-01

    Based on the theory and methodology of dendrochronology, the tree ring width chronology of Pinus sylvestris var. mongolica in Mangui of Great Xing' an Mountains was developed, and the relationships between the standardized tree ring width chronology and local climate factors (temperature and precipitation) as well as the effects of climate factors on the P. sylvestris var. mongolica radial growth were analyzed. In this region, the mean monthly temperature in April-August of current year was the main factor limiting the radial growth, and the increasing mean monthly temperature from April to August had negative effects to the radial growth. The simulation of the variations of the radial growth by the mean monthly temperature change in April-August showed that the radial growth of P. sylvestris var. mongolica would present a declining trend accompanied with the warmer and drier regional climate condition.

  19. The temperature distribution in a gas core fission reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hoogenboom, J.E.; Dam, H. van; Kuijper, J.C. (Interuniversitair Reactor Inst., Delft (Netherlands)); Kistemaker, J.; Boersma-Klein, W.; Vitalis, F. (FOM-Instituut voor Atoom-en Molecuulfysica, Amsterdam (Netherlands))

    1991-01-01

    A model is proposed for the heat transport in a nuclear reactor with gaseous fuel at high temperatures taking into account radiative and kinetic heat transfer. A derivation is given of the equation determining the temperature distribution in a gas core reactor and different numerical solution methods are discussed in detail. Results are presented of the temperature distribution. The influence of the kinetic heat transport and of dissociation of the gas molecules is shown. Also discussed is the importance of the temperature gradient at the reactor wall and its dependence on system parameters. (author).

  20. The temperature distribution in a gas core fission reactor

    International Nuclear Information System (INIS)

    Hoogenboom, J.E.; Dam, H. van; Kuijper, J.C.; Kistemaker, J.; Boersma-Klein, W.; Vitalis, F.

    1991-01-01

    A model is proposed for the heat transport in a nuclear reactor with gaseous fuel at high temperatures taking into account radiative and kinetic heat transfer. A derivation is given of the equation determining the temperature distribution in a gas core reactor and different numerical solution methods are discussed in detail. Results are presented of the temperature distribution. The influence of the kinetic heat transport and of dissociation of the gas molecules is shown. Also discussed is the importance of the temperature gradient at the reactor wall and its dependence on system parameters. (author)

  1. Distributed collaborative probabilistic design for turbine blade-tip radial running clearance using support vector machine of regression

    Science.gov (United States)

    Fei, Cheng-Wei; Bai, Guang-Chen

    2014-12-01

    To improve the computational precision and efficiency of probabilistic design for mechanical dynamic assembly like the blade-tip radial running clearance (BTRRC) of gas turbine, a distribution collaborative probabilistic design method-based support vector machine of regression (SR)(called as DCSRM) is proposed by integrating distribution collaborative response surface method and support vector machine regression model. The mathematical model of DCSRM is established and the probabilistic design idea of DCSRM is introduced. The dynamic assembly probabilistic design of aeroengine high-pressure turbine (HPT) BTRRC is accomplished to verify the proposed DCSRM. The analysis results reveal that the optimal static blade-tip clearance of HPT is gained for designing BTRRC, and improving the performance and reliability of aeroengine. The comparison of methods shows that the DCSRM has high computational accuracy and high computational efficiency in BTRRC probabilistic analysis. The present research offers an effective way for the reliability design of mechanical dynamic assembly and enriches mechanical reliability theory and method.

  2. DETERMINATION OF TEMPERATURE DISTRIBUTION FOR ANNULAR FINS WITH TEMPERATURE DEPENDENT THERMAL CONDUCTIVITY BY HPM

    Directory of Open Access Journals (Sweden)

    Davood Domairry Ganji

    2011-01-01

    Full Text Available In this paper, homotopy perturbation method has been used to evaluate the temperature distribution of annular fin with temperature-dependent thermal conductivity and to determine the temperature distribution within the fin. This method is useful and practical for solving the nonlinear heat transfer equation, which is associated with variable thermal conductivity condition. The homotopy perturbation method provides an approximate analytical solution in the form of an infinite power series. The annular fin heat transfer rate with temperature-dependent thermal conductivity has been obtained as a function of thermo-geometric fin parameter and the thermal conductivity parameter describing the variation of the thermal conductivity.

  3. Water structure as a function of temperature from X-ray scattering experiments and ab initio molecular dynamics

    International Nuclear Information System (INIS)

    Hura, Greg; Russo, Daniela; Glaeser, Robert M.; Head-Gordon, Teresa; Krack, Matthias; Parrinello, Michele

    2003-01-01

    We present high-quality X-ray scattering experiments on pure water taken over a temperature range of 2 to 77 C using a synchrotron beam line at the advanced light source (ALS) at Lawrence Berkeley National Laboratory. The ALS X-ray scattering intensities are qualitatively different in trend of maximum intensity over this temperature range compared to older X-ray experiments. While the common procedure is to report both the intensity curve and radial distribution function(s), the proper extraction of the real-space pair correlation functions from the experimental scattering is very difficult due to uncertainty introduced in the experimental corrections, the proper weighting of OO, OH, and HH contributions, and numerical problems of Fourier transforming truncated data in Q-space. Instead, we consider the direct calculation of X-ray scattering spectra using electron densities derived from density functional theory based on real-space configurations generated with classical water models. The simulation of the experimental intensity is therefore definitive for determining radial distribution functions over a smaller Q-range. We find that the TIP4P, TIP5P and polarizable TIP4P-Pol2 water models, with DFT-LDA densities, show very good agreement with the experimental intensities, and TIP4P-Pol2 in particular shows quantitative agreement over the full temperature range. The resulting radial distribution functions from TIP4P-Pol2 provide the current best benchmarks for real-space water structure over the biologically relevant temperature range studied here

  4. Temperature distribution and thermal stress

    Indian Academy of Sciences (India)

    Abstract. Thermal effects of a double-end-pumped cubic Nd:YVO4 laser crystal are investigated in this paper. A detailed analysis of temperature distribution and thermal stress in cubic crystal with circular shape pumping is discussed. It has been shown that by considering the total input powers as constant, the ...

  5. Stability of radial and non-radial pulsation modes of massive ZAMS models

    International Nuclear Information System (INIS)

    Odell, A.P.; Pausenwein, A.; Weiss, W.W.; Hajek, A.

    1987-01-01

    The authors have computed non-adiabatic eigenvalues for radial and non-radial pulsation modes of star models between 80 and 120 M solar with composition of chi=0.70 and Z=0.02. The radial fundamental mode is unstable in models with mass greater than 95 M solar , but the first overtone mode is always stable. The non-radial modes are all stable for all models, but the iota=2 f-mode is the closest to being driven. The non-radial modes are progressively more stable with higher iota and with higher n (for both rho- and g-modes). Thus, their results indicate that radial pulsation limits the upper mass of a star

  6. Dynamic Temperature Rise Mechanism and Some Controlling Factors of Wet Clutch Engagement

    Directory of Open Access Journals (Sweden)

    Zhang Zhigang

    2016-01-01

    Full Text Available The friction transmission model of wet clutch is established to analyze the friction transmission mechanism of its engagement. The model is developed by applying both the average flow model and the elastic contact model between the friction disk and separator plate. The key components during wet clutch engagement are the separator plate, friction disk, and lubricant. The one-dimension transient models of heat transfer in radial direction for the three components are built on the basis of the heat transfer theory and the conservation law of energy. The friction transmission model and transient heat transfer models are coupled and solved by using the Runge-Kutta numerical method, and the radial temperature distribution and their detailed parametric study for the three components are conducted separately. The simulation results show that the radial temperature for the three components rises with the increase of radius in engagement. The changes in engagement pressure, lubricant viscosity, friction lining permeability, combined surface roughness RMS, equivalent elasticity modulus, difference between dynamic and static friction coefficients, and lubricant flow have important influence on the temperature rise characteristics. The proposed models can get better understanding of the dynamic temperature rise characteristics of wet clutch engagement.

  7. Radial optimization of a BWR fuel cell using genetic algorithms

    International Nuclear Information System (INIS)

    Martin del Campo M, C.; Carmona H, R.; Oropeza C, I.P.

    2006-01-01

    The development of the application of the Genetic Algorithms (GA) to the optimization of the radial distribution of enrichment in a cell of fuel of a BWR (Boiling Water Reactor) is presented. The optimization process it was ties to the HELIOS simulator, which is a transport code of neutron simulation of fuel cells that has been validated for the calculation of nuclear banks for BWRs. With heterogeneous radial designs can improve the radial distribution of the power, for what the radial design of fuel has a strong influence in the global design of fuel recharges. The optimum radial distribution of fuel bars is looked for with different enrichments of U 235 and contents of consumable poison. For it is necessary to define the representation of the solution, the objective function and the implementation of the specific optimization process to the solution of the problem. The optimization process it was coded in 'C' language, it was automated the creation of the entrances to the simulator, the execution of the simulator and the extraction, in the exit of the simulator, of the parameters that intervene in the objective function. The objective function includes four parameters: average enrichment of the cell, average gadolinia concentration of the cell, peak factor of radial power and k-infinite multiplication factor. To be able to calculate the parameters that intervene in the objective function, the one evaluation process of GA was ties to the HELIOS code executed in a Compaq Alpha workstation. It was applied to the design of a fuel cell of 10 x 10 that it can be employee in the fuel assemble designs that are used at the moment in the Laguna Verde Nucleo electric Central. Its were considered 10 different fuel compositions which four contain gadolinia. Three heuristic rules that consist in prohibiting the placement of bars with gadolinia in the ends of the cell, to place the compositions with the smallest enrichment in the corners of the cell and to fix the placement of

  8. Linear radial pulsation theory. Lecture 5

    International Nuclear Information System (INIS)

    Cox, A.N.

    1983-01-01

    We describe a method for getting an equilibrium stellar envelope model using as input the total mass, the envelope mass, the surface effective temperature, the total surface luminosity, and the composition of the envelope. Then wih the structure of the envelope model known, we present a method for obtaining the raidal pulsation periods and growth rates for low order modes. The large amplitude pulsations observed for the yellow and red giants and supergiants are always these radial models, but for the stars nearer the main sequence, as for all of our stars and for the white dwarfs, there frequently are nonradial modes occuring also. Application of linear theory radial pulsation theory is made to the giant star sigma Scuti variables, while the linear nonradial theory will be used for the B stars in later lectures

  9. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Science.gov (United States)

    Jiang, Yuan; Zhang, Wentao; Wang, Mingchang; Kang, Muyi; Dong, Manyu

    2014-01-01

    North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1) The two species grew in different rhythms at low and high elevation respectively; (2) Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3) The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4) The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  10. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    Full Text Available North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1 The two species grew in different rhythms at low and high elevation respectively; (2 Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3 The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4 The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  11. Radial Structure Scaffolds Convolution Patterns of Developing Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Mir Jalil Razavi

    2017-08-01

    Full Text Available Commonly-preserved radial convolution is a prominent characteristic of the mammalian cerebral cortex. Endeavors from multiple disciplines have been devoted for decades to explore the causes for this enigmatic structure. However, the underlying mechanisms that lead to consistent cortical convolution patterns still remain poorly understood. In this work, inspired by prior studies, we propose and evaluate a plausible theory that radial convolution during the early development of the brain is sculptured by radial structures consisting of radial glial cells (RGCs and maturing axons. Specifically, the regionally heterogeneous development and distribution of RGCs controlled by Trnp1 regulate the convex and concave convolution patterns (gyri and sulci in the radial direction, while the interplay of RGCs' effects on convolution and axons regulates the convex (gyral convolution patterns. This theory is assessed by observations and measurements in literature from multiple disciplines such as neurobiology, genetics, biomechanics, etc., at multiple scales to date. Particularly, this theory is further validated by multimodal imaging data analysis and computational simulations in this study. We offer a versatile and descriptive study model that can provide reasonable explanations of observations, experiments, and simulations of the characteristic mammalian cortical folding.

  12. RADIAL STABILITY IN STRATIFIED STARS

    International Nuclear Information System (INIS)

    Pereira, Jonas P.; Rueda, Jorge A.

    2015-01-01

    We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the boundary conditions connecting any two phases within a star and underline its relevance for realistic models of compact stars with phase transitions, owing to the modification of the star's set of eigenmodes with respect to the continuous case

  13. Radial mixing of material in the asterodial zone

    International Nuclear Information System (INIS)

    Ruzmaikina, T.V.; Safronov, V.S.; Weidenschilling, S.J.

    1989-01-01

    The asteroid belt shows radial zoning of compositional structure. The most abundant types are successively S, C and P types from the inner to the outer parts of the main belt, and D type in the Trojan clouds. Boundaries between compositional zones are not sharp, but gradual transitions over scales ∼1 AU in semimajor axis. The authors examine processes for producing this structure before, during and after the accretion of asteroids. The initial structure is established by temperature and composition gradients in the turbulent solar nebula during the collapse of the presolar cloud. The radial scale of the zoning, comparable to the disk thickness, favors disk models with relatively low turbulent viscosity. Radial decay of solid bodies due to gas drag during settling to the central plane and planetesimal formation probably causes only a small degree of mixing, due to the systematic nature of drag-induced motions

  14. Radial restricted solid-on-solid and etching interface-growth models

    Science.gov (United States)

    Alves, Sidiney G.

    2018-03-01

    An approach to generate radial interfaces is presented. A radial network recursively obtained is used to implement discrete model rules designed originally for the investigation in flat substrates. I used the restricted solid-on-solid and etching models as to test the proposed scheme. The results indicate the Kardar, Parisi, and Zhang conjecture is completely verified leading to a good agreement between the interface radius fluctuation distribution and the Gaussian unitary ensemble. The evolution of the radius agrees well with the generalized conjecture, and the two-point correlation function exhibits also a good agreement with the covariance of the Airy2 process. The approach can be used to investigate radial interfaces evolution for many other classes of universality.

  15. Determination of gas temperature in the plasmatron channel according to the known distribution of electronic temperature

    Directory of Open Access Journals (Sweden)

    Gerasimov Alexander V.

    2013-01-01

    Full Text Available An analytical method to calculate the temperature distribution of heavy particles in the channel of the plasma torch on the known distribution of the electronic temperature has been proposed. The results can be useful for a number of model calculations in determining the most effective conditions of gas blowing through the plasma torch with the purpose of heating the heavy component. This approach allows us to understand full details about the heating of cold gas, inpouring the plasma, and to estimate correctly the distribution of the gas temperature inside the channel.

  16. Radial Transport and Meridional Circulation in Accretion Disks

    Energy Technology Data Exchange (ETDEWEB)

    Philippov, Alexander A. [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States); Rafikov, Roman R., E-mail: sashaph@princeton.edu [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

    2017-03-10

    Radial transport of particles, elements and fluid driven by internal stresses in three-dimensional (3D) astrophysical accretion disks is an important phenomenon, potentially relevant for the outward dust transport in protoplanetary disks, origin of the refractory particles in comets, isotopic equilibration in the Earth–Moon system, etc. To gain better insight into these processes, we explore the dependence of meridional circulation in 3D disks with shear viscosity on their thermal stratification, and demonstrate a strong effect of the latter on the radial flow. Previous locally isothermal studies have normally found a pattern of the radial outflow near the midplane, switching to inflow higher up. Here we show, both analytically and numerically, that a flow that is inward at all altitudes is possible in disks with entropy and temperature steeply increasing with height. Such thermodynamic conditions may be typical in the optically thin, viscously heated accretion disks. Disks in which these conditions do not hold should feature radial outflow near the midplane, as long as their internal stress is provided by the shear viscosity. Our results can also be used for designing hydrodynamical disk simulations with a prescribed pattern of the meridional circulation.

  17. Analysis on Coupled Vibration of a Radially Polarized Piezoelectric Cylindrical Transducer

    Directory of Open Access Journals (Sweden)

    Jie Xu

    2017-12-01

    Full Text Available Coupled vibration of a radially polarized piezoelectric cylindrical transducer is analyzed with the mechanical coupling coefficient method. The method has been utilized to analyze the metal cylindrical transducer and the axially polarized piezoelectric cylindrical transducer. In this method, the mechanical coupling coefficient is introduced and defined as the stress ratio in different directions. Coupled vibration of the cylindrical transducer is regarded as the interaction of the plane radial vibration of a ring and the longitudinal vibration of a tube. For the radially polarized piezoelectric cylindrical transducer, the radial and longitudinal electric admittances as functions of mechanical coupling coefficients and angular frequencies are derived, respectively. The resonance frequency equations are obtained. The dependence of resonance frequency and mechanical coupling coefficient on aspect ratio is studied. Vibrational distributions on the surfaces of the cylindrical transducer are presented with experimental measurement. On the support of experiments, this work is verified and provides a theoretical foundation for the analysis and design of the radially polarized piezoelectric cylindrical transducer.

  18. Propagation of a radial phased-locked Lorentz beam array in turbulent atmosphere.

    Science.gov (United States)

    Zhou, Guoquan

    2011-11-21

    A radial phased-locked (PL) Lorentz beam array provides an appropriate theoretical model to describe a coherent diode laser array, which is an efficient radiation source for high-power beaming use. The propagation of a radial PL Lorentz beam array in turbulent atmosphere is investigated. Based on the extended Huygens-Fresnel integral and some mathematical techniques, analytical formulae for the average intensity and the effective beam size of a radial PL Lorentz beam array are derived in turbulent atmosphere. The average intensity distribution and the spreading properties of a radial PL Lorentz beam array in turbulent atmosphere are numerically calculated. The influences of the beam parameters and the structure constant of the atmospheric turbulence on the propagation of a radial PL Lorentz beam array in turbulent atmosphere are discussed in detail. © 2011 Optical Society of America

  19. THE INFLUENCE OF RADIAL STELLAR MIGRATION ON THE CHEMICAL EVOLUTION OF THE MILKY WAY

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yue; Zhao Gang, E-mail: gzhao@nao.cas.cn [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2013-05-20

    Stellar migration is an important dynamical process in the Galactic disk. Here we model radial stellar migration in the Galactic disk with an analytical method, then add it to a detailed Galactic chemical evolution model to study the influence of radial stellar migration on the chemical evolution of the Milky Way, especially for the abundance gradients. We found that the radial stellar migration in the Galactic disk can make the profile of the G-dwarf metallicity distribution of the solar neighborhood taller and narrower, and thus it becomes another solution to the ''G-dwarf problem''. It can also scatter the age-metallicity relation. However, after migration, the abundance distributions along the Galactic radius do not change much; namely, the abundance gradients would not be flattened by the radial stellar migration, which is different from the predictions of many theoretical works. However, it can flatten the radial gradients of the mean chemical abundance of stars, and older stars possess flatter abundance gradients than younger stars. The most significant effect of radial stellar migration on the chemical abundance is that at a certain position it scatters the abundance of stars from a relatively concentrated value to a range.

  20. Temperature measurement distributed on a building by fiber optic BOTDA sensor

    International Nuclear Information System (INIS)

    Kwon, Il Bum; Kim, Chi Yeop; Choi, Man Yong; Lee, Seung Seok

    2002-01-01

    We have focused on the development of a fiber optic BOTDA (Brillouin Optical Time Domain Analysis) sensor system in order to measure temperature distributed on large structures. Also, we present a feasibility study of the fiber optic sensor to monitor the distributed temperature on a building construction. A fiber optic BOTDA sensor system, which has a capability of measuring the temperature distribution, attempted over several kilometers of long fiber paths. This simple fiber optic sensor system employs a laser diode and two electro-optic modulators. The optical fiber of the length of 1400 m was installed on the surfaces of the building. The change of the distributed temperature on the building construction was well measured by this fiber optic sensor. The temperature changed normally up to 4 degrees C through one day.

  1. Effects of Recent Minimum Temperature and Water Deficit Increases on Pinus pinaster Radial Growth and Wood Density in Southern Portugal.

    Science.gov (United States)

    Kurz-Besson, Cathy B; Lousada, José L; Gaspar, Maria J; Correia, Isabel E; David, Teresa S; Soares, Pedro M M; Cardoso, Rita M; Russo, Ana; Varino, Filipa; Mériaux, Catherine; Trigo, Ricardo M; Gouveia, Célia M

    2016-01-01

    Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant growth. It is not clear to what extent wood growth and density of agroforestry species have suffered from such changes or recent extreme climate events. To address this question, tree-ring width and density chronologies were built for a Pinus pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI) multi-scalar drought index, between 1 to 24-months. The climate-growth/density relationships were evaluated for the period 1958-2011. We show that both wood radial growth and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial growth and density. Despite of the intensification of long-term water deficit, tree-ring width appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-ring density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster's vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster's production capacity and quality in response to more arid conditions in the near future in the region.

  2. Effects of Recent Minimum Temperature and Water Deficit Increases on Pinus pinaster Radial Growth and Wood Density in Southern Portugal

    Science.gov (United States)

    Kurz-Besson, Cathy B.; Lousada, José L.; Gaspar, Maria J.; Correia, Isabel E.; David, Teresa S.; Soares, Pedro M. M.; Cardoso, Rita M.; Russo, Ana; Varino, Filipa; Mériaux, Catherine; Trigo, Ricardo M.; Gouveia, Célia M.

    2016-01-01

    Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant growth. It is not clear to what extent wood growth and density of agroforestry species have suffered from such changes or recent extreme climate events. To address this question, tree-ring width and density chronologies were built for a Pinus pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI) multi-scalar drought index, between 1 to 24-months. The climate-growth/density relationships were evaluated for the period 1958-2011. We show that both wood radial growth and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial growth and density. Despite of the intensification of long-term water deficit, tree-ring width appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-ring density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster’s vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster’s production capacity and quality in response to more arid conditions in the near future in the region. PMID:27570527

  3. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    International Nuclear Information System (INIS)

    Falabella, S.

    1988-01-01

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10 12 cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs

  4. Measurements of radial profiles of ion cyclotron resonance heating on the Tandem Mirror Experiment-Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Falabella, S.

    1988-05-11

    A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawerence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). The probe has been inserted into the central-cell plasma at temperatures of 200 eV and densities of 3 x 10/sup 12/cm/sup /minus 3// without damage to the probe, or major degradation of the plasma. This analyzer has indicated an increase in ion temperature from near 20 eV before ICRH to near 150 eV during ICRH, with about 60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial intergral of n/sub i/T/sub i/ as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma is seen to vary from axially peaked, to nearly flat as the plasma conditions carried over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U. 62 refs., 63 figs., 7 tabs.

  5. Variation of Drying Strains between Tangential and Radial Directions in Asian White Birch

    Directory of Open Access Journals (Sweden)

    Zongying Fu

    2016-03-01

    Full Text Available In this study, wood disks of 30 mm in thickness cut from white birch (Betula platyphylla Suk logs were dried at a constant temperature (40 °C. The drying strains including practical shrinkage strain, elastic strain, viscoelastic creep strain and mechano-sorptive creep were measured both tangentially and radially. The effects of moisture content and radial position on each strain were also discussed qualitatively. Overall, the difference of the practical shrinkage strain between the tangential and radial directions was proportional to the distance from the pith. The tangential elastic strain and viscoelastic creep strain were higher than these strains in a radial direction, and they all decreased with the decrease of moisture content. Additionally, there were opposite mechano-sorptive creep between tangential and radial directions.

  6. Radial growth of Qilian juniper on the Northeast Tibetan Plateau and potential climate associations.

    Directory of Open Access Journals (Sweden)

    Chun Qin

    Full Text Available There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110-2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes.

  7. Radial growth of Qilian juniper on the Northeast Tibetan Plateau and potential climate associations.

    Science.gov (United States)

    Qin, Chun; Yang, Bao; Melvin, Thomas M; Fan, Zexin; Zhao, Yan; Briffa, Keith R

    2013-01-01

    There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110-2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes.

  8. Soil temperature variability in complex terrain measured using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Soil temperature (Ts) exerts critical controls on hydrologic and biogeochemical processes but magnitude and nature of Ts variability in a landscape setting are rarely documented. Fiber optic distributed temperature sensing systems (FO-DTS) potentially measure Ts at high density over a large extent. ...

  9. Microstructure, optical characterization and light induced degradation in a-Si:H deposited at different temperatures

    International Nuclear Information System (INIS)

    Minani, E.; Sigcau, Z.; Adgebite, O.; Ramukosi, F.L.; Ntsoane, T.P.; Harindintwari, S.; Knoesen, D.; Comrie, C.M.; Britton, D.T.; Haerting, M.

    2006-01-01

    The microstructure and optical properties of a series of hydrogenated amorphous silicon layers deposited on glass substrates at different temperature have been characterized by means of X-ray diffraction techniques and optical spectroscopy. The radial distribution function of the as-deposited samples showed an increase in the bond angle and a decrease in the radial distance indicating a relaxation of the amorphous network with increasing the deposition temperature. Light induced degradation was studied using a simulated daylight spectrum. The changes in hydrogen bonding configuration, associated with the light soaking at different stages of illumination, was monitored via the transmission bands of the vibrational wag and stretch modes of the IR spectrum

  10. Investigation on the radial micro-motion about piston of axial piston pump

    Science.gov (United States)

    Xu, Bing; Zhang, Junhui; Yang, Huayong; Zhang, Bin

    2013-03-01

    The limit working parameters and service life of axial piston pump are determined by the carrying ability and lubrication characteristic of its key friction pairs. Therefore, the design and optimization of the key friction pairs are always a key and difficult problem in the research on axial piston pump. In the traditional research on piston/cylinder pair, the assembly relationship of piston and cylinder bore is simplified into ideal cylindrical pair, which can not be used to analyze the influences of radial micro-motion of piston on the distribution characteristics of oil-film thickness and pressure in details. In this paper, based on the lubrication theory of the oil film, a numerical simulation model is built, taking the influences of roughness, elastic deformation of piston and pressure-viscosity effect into consideration. With the simulation model, the dynamic characteristics of the radial micro-motion and pressure distribution are analyzed, and the relationships between radial micro-motion and carrying ability, lubrication condition, and abrasion are discussed. Furthermore, a model pump for pressure distribution measurement of oil film between piston and cylinder bore is designed. The comparison of simulation and experimental results of pressure distribution shows that the simulation model has high accuracy. The experiment and simulation results demonstrate that the pressure distribution has peak values that are much higher than the boundary pressure in the piston chamber due to the radial micro-motion, and the abrasion of piston takes place mainly on the hand close to piston ball. In addition, improvement of manufacturing roundness and straightness of piston and cylinder bore is helpful to improve the carrying ability of piston/cylinder pair. The proposed research provides references for designing piston/cylinder pair, and helps to prolong the service life of axial piston pump.

  11. Finite element analysis for temperature distributions in a cold forging

    International Nuclear Information System (INIS)

    Kim, Dong Bum; Lee, In Hwan; Cho, Hae Yong; Kim, Sung Wook; Song, In Chul; Jeon, Byung Cheol

    2013-01-01

    In this research, the finite element method is utilized to predict the temperature distributions in a cold-forging process for a cambolt. The cambolt is mainly used as a part of a suspension system of a vehicle. The cambolt has an off-centered lobe that manipulates the vertical position of the knuckle and wheel to a slight degree. The cambolt requires certain mechanical properties, such as strength and endurance limits. Moreover, temperature is also an important factor to realize mass production and improve efficiency. However, direct measurement of temperature in a forging process is infeasible with existing technology; therefore, there is a critical need for a new technique. Accordingly, in this study, a thermo-coupled finite element method is developed for predicting the temperature distribution. The rate of energy conversion to heat for the workpiece material is determined, and the temperature distribution is analyzed throughout the forging process for a cambolt. The temperatures associated with different punch speeds are also studied, as well as the relationships between load, temperature, and punch speed. Experimental verification of the technique is presented.

  12. Finite element analysis for temperature distributions in a cold forging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Bum; Lee, In Hwan; Cho, Hae Yong [Chungbuk National University, Cheongju (Korea, Republic of); Kim, Sung Wook [Yanbian National University, Yanbian (China); Song, In Chul; Jeon, Byung Cheol [Sunil dyfas, Jincheon (Korea, Republic of)

    2013-10-15

    In this research, the finite element method is utilized to predict the temperature distributions in a cold-forging process for a cambolt. The cambolt is mainly used as a part of a suspension system of a vehicle. The cambolt has an off-centered lobe that manipulates the vertical position of the knuckle and wheel to a slight degree. The cambolt requires certain mechanical properties, such as strength and endurance limits. Moreover, temperature is also an important factor to realize mass production and improve efficiency. However, direct measurement of temperature in a forging process is infeasible with existing technology; therefore, there is a critical need for a new technique. Accordingly, in this study, a thermo-coupled finite element method is developed for predicting the temperature distribution. The rate of energy conversion to heat for the workpiece material is determined, and the temperature distribution is analyzed throughout the forging process for a cambolt. The temperatures associated with different punch speeds are also studied, as well as the relationships between load, temperature, and punch speed. Experimental verification of the technique is presented.

  13. Technology Requirements and Development for Affordable High-Temperature Distributed Engine Controls

    Science.gov (United States)

    2012-06-04

    long lasting, high temperature modules is to use high temperature electronics on ceramic modules. The electronic components are “ brazed ” onto the...Copyright © 2012 by ISA Technology Requirements and Development for Affordable High - Temperature Distributed Engine Controls Alireza Behbahani 1...with regards to high temperature capability. The Government and Industry Distributed Engine Controls Working Group (DECWG) [5] has been established

  14. Radial electric field in JET advanced tokamak scenarios with toroidal field ripple

    Energy Technology Data Exchange (ETDEWEB)

    Crombe, K [Postdoctoral Fellow of the Research Foundation - Flanders (FWO), Department of Applied Physics, Ghent University, Rozier 44, B-9000 Gent (Belgium); Andrew, Y; De Vries, P C; Giroud, C; Hawkes, N C; Meigs, A; Zastrow, K-D [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Biewer, T M [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169, TN (United States); Blanco, E [Laboratorio Nacional de Fusion, Asociacion EURATOM-CIEMAT, Madrid (Spain); Tala, T [VTT Technical Research Centre of Finland, Association EURATOM-Tekes, PO Box 1000, FIN-02044 VTT (Finland); Von Hellermann, M [FOM Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, Trilateral Euregio Cluster, PO Box 1207, 3430 BE Nieuwegein (Netherlands)], E-mail: Kristel.Crombe@jet.uk

    2009-05-15

    A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (v{sub {theta}}) in the ITB region is measured to be of the order of a few tens of km s{sup -1}, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of v{sub {theta}} is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (E{sub r}), with the largest gradient in E{sub r} measured in the radial region coinciding with the ITB.

  15. A CHANDRA STUDY OF TEMPERATURE DISTRIBUTIONS OF THE INTRACLUSTER MEDIUM IN 50 GALAXY CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zhenghao; Xu, Haiguang; Li, Weitian; Hu, Dan; Zhang, Chenhao; Liu, Chengze [Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang, Shanghai 200240 (China); Wang, Jingying; Gu, Junhua; Wu, Xiang-Ping [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100012 (China); Gu, Liyi [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands); An, Tao [Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Zhang, Zhongli [Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, Postfach 1317, D-85741 Garching (Germany); Zhu, Jie, E-mail: clsn@sjtu.edu.cn, E-mail: hgxu@sjtu.edu.cn [Department of Electronic Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang, Shanghai 200240 (China)

    2016-01-10

    To investigate the spatial distribution of the intracluster medium temperature in galaxy clusters in a quantitative way and probe the physics behind it, we analyze the X-ray spectra from a sample of 50 clusters that were observed with the Chandra ACIS instrument over the past 15 years and measure the radial temperature profiles out to 0.45r{sub 500}. We construct a physical model that takes into consideration the effects of gravitational heating, thermal history (such as radiative cooling, active galactic nucleus feedback, and thermal conduction), and work done via gas compression, and use it to fit the observed temperature profiles by running Bayesian regressions. The results show that in all cases our model provides an acceptable fit at the 68% confidence level. For further validation, we select nine clusters that have been observed with both Chandra (out to ≳0.3r{sub 500}) and Suzaku (out to ≳1.5r{sub 500}) and fit their Chandra spectra with our model. We then compare the extrapolation of the best fits with the Suzaku measurements and find that the model profiles agree with the Suzaku results very well in seven clusters. In the remaining two clusters the difference between the model and the observation is possibly caused by local thermal substructures. Our study also implies that for most of the clusters the assumption of hydrostatic equilibrium is safe out to at least 0.5r{sub 500} and the non-gravitational interactions between dark matter and its luminous counterparts is consistent with zero.

  16. Optical cage generated by azimuthal- and radial-variant vector beams.

    Science.gov (United States)

    Man, Zhongsheng; Bai, Zhidong; Li, Jinjian; Zhang, Shuoshuo; Li, Xiaoyu; Zhang, Yuquan; Ge, Xiaolu; Fu, Shenggui

    2018-05-01

    We propose a method to generate an optical cage using azimuthal- and radial-variant vector beams in a high numerical aperture optical system. A new kind of vector beam that has azimuthal- and radial-variant polarization states is proposed and demonstrated theoretically. Then, an integrated analytical model to calculate the electromagnetic field and Poynting vector distributions of the input azimuthal- and radial-variant vector beams is derived and built based on the vector diffraction theory of Richards and Wolf. From calculations, a full polarization-controlled optical cage is obtained by simply tailoring the radial index of the polarization, the uniformity U of which is up to 0.7748, and the cleanness C is zero. Additionally, a perfect optical cage can be achieved with U=1, and C=0 by introducing an amplitude modulation; its magnetic field and energy flow are also demonstrated in detail. Such optical cages may be helpful in applications such as optical trapping and high-resolution imaging.

  17. Channeling of protons in various types of radially compressed carbon nanotubes

    International Nuclear Information System (INIS)

    Karabarbounis, A.; Sarros, S.; Trikalinos, Ch.

    2015-01-01

    Channeling of 10 MeV protons in various types of radially compressed chiral carbon nanotubes is considered. Monte Carlo simulation program is used for the calculation of the trajectories, energy losses and angular distributions of protons in nanotubes of various lengths, where the potential in Doyle–Turner approximation is used to describe the interaction between a proton and a nanotube. Carbon nanotubes, which are considered, are radially compressed at the centre or at both ends. The results show that in some cases a decreased angular distribution of the beam is observed, compared with propagation through a straight nanotube. Furthermore, the energy distribution of channeled protons in nanotubes present a series of small peaks besides a main one, the number of which depends on the nanotube length and the angle of incidence, which in some cases are significantly high

  18. Channeling of protons in various types of radially compressed carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Karabarbounis, A. [Department of Physics, Section of Nuclear and Particle Physics, University of Athens, Panepistimioupolis, Ilissia, 15771 Athens (Greece); Sarros, S., E-mail: stsarros@phys.uoa.gr [Department of Physics, Section of Nuclear and Particle Physics, University of Athens, Panepistimioupolis, Ilissia, 15771 Athens (Greece); Trikalinos, Ch. [Department of Philosophy and History of Science, University of Athens, Panepistimioupolis, Ilissia, 15771 Athens (Greece)

    2015-07-15

    Channeling of 10 MeV protons in various types of radially compressed chiral carbon nanotubes is considered. Monte Carlo simulation program is used for the calculation of the trajectories, energy losses and angular distributions of protons in nanotubes of various lengths, where the potential in Doyle–Turner approximation is used to describe the interaction between a proton and a nanotube. Carbon nanotubes, which are considered, are radially compressed at the centre or at both ends. The results show that in some cases a decreased angular distribution of the beam is observed, compared with propagation through a straight nanotube. Furthermore, the energy distribution of channeled protons in nanotubes present a series of small peaks besides a main one, the number of which depends on the nanotube length and the angle of incidence, which in some cases are significantly high.

  19. Formation of electron-root radial electric field and its effect on thermal transport in LHD high Te plasma

    International Nuclear Information System (INIS)

    Matsuoka, Seikichi; Satake, Shinsuke; Takahashi, Hiromi; Yokoyama, Masayuki; Ido, Takeshi; Shimizu, Akihiro; Shimozuma, Takashi; Wakasa, Arimitsu; Murakami, Sadayoshi

    2013-01-01

    Neoclassical transport analyses have been performed for a high electron temperature LHD plasma with steep temperature gradient using a neoclassical transport simulation code, FORTEC-3D. It is shown that the large positive radial electric field is spontaneously formed at the core along with the increase in the electron temperature, while the neoclassical heat diffusivity remains almost unchanged. This indicates that the 1/ν-type increase expected in the neoclassical transport in helical plasmas can be avoided by the spontaneous formation of the radial electric field. At the same time, it is found that the experimentally estimated heat diffusivity is significantly reduced. This suggests that the formation process of the transport barrier in the high electron temperature plasma can be caused by the spontaneous formation of the radial electric field. (author)

  20. Effect of two-temperature electrons distribution on an electrostatic plasma sheath

    International Nuclear Information System (INIS)

    Ou, Jing; Xiang, Nong; Gan, Chunyun; Yang, Jinhong

    2013-01-01

    A magnetized collisionless plasma sheath containing two-temperature electrons is studied using a one-dimensional model in which the low-temperature electrons are described by Maxwellian distribution (MD) and high-temperature electrons are described by truncated Maxwellian distribution (TMD). Based on the ion wave approach, a modified sheath criterion including effect of TMD caused by high-temperature electrons energy above the sheath potential energy is established theoretically. The model is also used to investigate numerically the sheath structure and energy flux to the wall for plasmas parameters of an open divertor tokamak-like. Our results show that the profiles of the sheath potential, two-temperature electrons and ions densities, high-temperature electrons and ions velocities as well as the energy flux to the wall depend on the high-temperature electrons concentration, temperature, and velocity distribution function associated with sheath potential. In addition, the results obtained in the high-temperature electrons with TMD as well as with MD sheaths are compared for the different sheath potential

  1. Temperature distribution of thick thermoset composites

    Science.gov (United States)

    Guo, Zhan-Sheng; Du, Shanyi; Zhang, Boming

    2004-05-01

    The development of temperature distribution of thick polymeric matrix laminates during an autoclave vacuum bag process was measured and compared with numerically calculated results. The finite element formulation of the transient heat transfer problem was carried out for polymeric matrix composite materials from the heat transfer differential equations including internal heat generation produced by exothermic chemical reactions. Software based on the general finite element software package was developed for numerical simulation of the entire composite process. From the experimental and numerical results, it was found that the measured temperature profiles were in good agreement with the numerical ones, and conventional cure cycles recommended by prepreg manufacturers for thin laminates should be modified to prevent temperature overshoot.

  2. Sea Surface Temperature Modeling using Radial Basis Function Networks With a Dynamically Weighted Particle Filter

    KAUST Repository

    Ryu, Duchwan

    2013-03-01

    The sea surface temperature (SST) is an important factor of the earth climate system. A deep understanding of SST is essential for climate monitoring and prediction. In general, SST follows a nonlinear pattern in both time and location and can be modeled by a dynamic system which changes with time and location. In this article, we propose a radial basis function network-based dynamic model which is able to catch the nonlinearity of the data and propose to use the dynamically weighted particle filter to estimate the parameters of the dynamic model. We analyze the SST observed in the Caribbean Islands area after a hurricane using the proposed dynamic model. Comparing to the traditional grid-based approach that requires a supercomputer due to its high computational demand, our approach requires much less CPU time and makes real-time forecasting of SST doable on a personal computer. Supplementary materials for this article are available online. © 2013 American Statistical Association.

  3. Hydration of Caffeine at High Temperature by Neutron Scattering and Simulation Studies.

    Science.gov (United States)

    Tavagnacco, L; Brady, J W; Bruni, F; Callear, S; Ricci, M A; Saboungi, M L; Cesàro, A

    2015-10-22

    The solvation of caffeine in water is examined with neutron diffraction experiments at 353 K. The experimental data, obtained by taking advantage of isotopic H/D substitution in water, were analyzed by empirical potential structure refinement (EPSR) in order to extract partial structure factors and site-site radial distribution functions. In parallel, molecular dynamics (MD) simulations were carried out to interpret the data and gain insight into the intermolecular interactions in the solutions and the solvation process. The results obtained with the two approaches evidence differences in the individual radial distribution functions, although both confirm the presence of caffeine stacks at this temperature. The two approaches point to different accessibility of water to the caffeine sites due to different stacking configurations.

  4. Temperature distribution and heat radiation of patterned surfaces at short wavelengths

    Science.gov (United States)

    Emig, Thorsten

    2017-05-01

    We analyze the equilibrium spatial distribution of surface temperatures of patterned surfaces. The surface is exposed to a constant external heat flux and has a fixed internal temperature that is coupled to the outside heat fluxes by finite heat conductivity across the surface. It is assumed that the temperatures are sufficiently high so that the thermal wavelength (a few microns at room temperature) is short compared to all geometric length scales of the surface patterns. Hence the radiosity method can be employed. A recursive multiple scattering method is developed that enables rapid convergence to equilibrium temperatures. While the temperature distributions show distinct dependence on the detailed surface shapes (cuboids and cylinder are studied), we demonstrate robust universal relations between the mean and the standard deviation of the temperature distributions and quantities that characterize overall geometric features of the surface shape.

  5. Impurity profiles and radial transport in the EXTRAP-T2 reversed field pinch

    International Nuclear Information System (INIS)

    Sallander, J.

    1999-01-01

    Radially resolved spectroscopy has been used to measure the radial distribution of impurity ions (O III-O V and C III-CVI) in the EXTRAP-T2 reversed field pinch (RFP). The radial profile of the emission is reconstructed from line emission measured along five lines of sight. The ion density profile is the fitted quantity in the reconstruction of the brightness profile and is thus obtained directly in this process. These measurements are then used to adjust the parameters in transport calculations in order to obtain consistency with the observed ion density profiles. Comparison between model and measurements show that a radial dependence in the diffusion is needed to explain the measured ion densities. (author)

  6. Impurity profiles and radial transport in the EXTRAP-T2 reversed field pinch

    Science.gov (United States)

    Sallander, J.

    1999-05-01

    Radially resolved spectroscopy has been used to measure the radial distribution of impurity ions (O III-O V and C III-CVI) in the EXTRAP-T2 reversed field pinch (RFP). The radial profile of the emission is reconstructed from line emission measured along five lines of sight. The ion density profile is the fitted quantity in the reconstruction of the brightness profile and is thus obtained directly in this process. These measurements are then used to adjust the parameters in transport calculations in order to obtain consistency with the observed ion density profiles. Comparison between model and measurements show that a radial dependence in the diffusion is needed to explain the measured ion densities.

  7. Experimental determination of neutron temperature distribution in reactor cell

    International Nuclear Information System (INIS)

    Bosevski, T.

    1965-12-01

    This paper describes theoretical preparation of the experiment for measuring neutron temperature distribution at the RB reactor by activation foils. Due to rather low neutron flux Cu and Lu foil were irradiated for 4 days. Special natural uranium fuel element was prepared to enable easy removal of foils after irradiation. Experimental device was placed in the reactor core at half height in order to measure directly the mean neutron density. Experimental data of neutron temperature distribution for square lattice pitch 16 cm are presented with mean values of neutron temperature in the moderator, in the fuel and on the fuel element surface

  8. Incorporation of distributed generation and shunt capacitor in radial distribution system for techno-economic benefits

    Directory of Open Access Journals (Sweden)

    Mukul Dixit

    2017-04-01

    The various costs such as purchase active power from grid, DG installation, capacitor installation, DG Operation and Maintenance (O&M are evaluated at two different load scenarios. In addition to that, technical and economical analyses are examined for various combinations of DGs and shunt capacitors. The proposed methodology is successfully demonstrated on 33-bus and 85-bus radial networks and the obtained numerical outcomes validate the suitability, importance and effectiveness to identify locations as well as sizes of DGs and shunt capacitors.

  9. Study on the radial vibration and acoustic field of an isotropic circular ring radiator.

    Science.gov (United States)

    Lin, Shuyu; Xu, Long

    2012-01-01

    Based on the exact analytical theory, the radial vibration of an isotropic circular ring is studied and its electro-mechanical equivalent circuit is obtained. By means of the equivalent circuit model, the resonance frequency equation is derived; the relationship between the radial resonance frequency, the radial displacement amplitude magnification and the geometrical dimensions, the material property is analyzed. For comparison, numerical method is used to simulate the radial vibration of isotropic circular rings. The resonance frequency and the radial vibrational displacement distribution are obtained, and the radial radiation acoustic field of the circular ring in radial vibration is simulated. It is illustrated that the radial resonance frequencies from the analytical method and the numerical method are in good agreement when the height is much less than the radius. When the height becomes large relative to the radius, the frequency deviation from the two methods becomes large. The reason is that the exact analytical theory is limited to thin circular ring whose height must be much less than its radius. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Transient temperature distributions in geological media surrounding radioactive waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Beyerlein, S W; Sunderland, J E [Massachusetts Univ., Amherst (USA). Dept. of Mechanical Engineering

    1981-01-01

    Closed form analytical solutions are presented for the transient temperature distributions resulting from underground radioactive waste disposal. The thermal source term is represented by point or spherical sources whose strength decreases exponentially with time. The transient temperature distributions can be determined above the disposal horizon over a time interval of hundreds of years.

  11. Development of a Radial Deconsolidation Method

    Energy Technology Data Exchange (ETDEWEB)

    Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    A series of experiments have been initiated to determine the retention or mobility of fission products* in AGR fuel compacts [Petti, et al. 2010]. This information is needed to refine fission product transport models. The AGR-3/4 irradiation test involved half-inch-long compacts that each contained twenty designed-to-fail (DTF) particles, with 20-μm thick carbon-coated kernels whose coatings were deliberately fabricated such that they would crack under irradiation, providing a known source of post-irradiation isotopes. The DTF particles in these compacts were axially distributed along the compact centerline so that the diffusion of fission products released from the DTF kernels would be radially symmetric [Hunn, et al. 2012; Hunn et al. 2011; Kercher, et al. 2011; Hunn, et al. 2007]. Compacts containing DTF particles were irradiated at Idaho National Laboratory (INL) at the Advanced Test Reactor (ATR) [Collin, 2015]. Analysis of the diffusion of these various post-irradiation isotopes through the compact requires a method to radially deconsolidate the compacts so that nested-annular volumes may be analyzed for post-irradiation isotope inventory in the compact matrix, TRISO outer pyrolytic carbon (OPyC), and DTF kernels. An effective radial deconsolidation method and apparatus appropriate to this application has been developed and parametrically characterized.

  12. The Temperature of the Dimethylhydrazine Drops Moving in the Atmosphere after Depressurization of the Fuel Tank Rockets

    Directory of Open Access Journals (Sweden)

    Bulba Elena

    2016-01-01

    Full Text Available This work includes the results of the numerical modeling of temperature changes process of the dimethylhydrazine (DMH drops, taking into account the radial temperature gradient in the air after the depressurization of the fuel compartments rockets at high altitude. There is formulated a mathematical model describing the process of DMH drops thermal state modifying when it's moving to the Earth's surface. There is the evaluation of the influence of the characteristic size of heptyl drops on the temperature distribution. It's established that the temperatures of the small size droplets practically completely coincide with the distribution of temperature in the atmosphere at altitudes of up to 40 kilometers.

  13. Relationship between Luminosity, Irradiance and Temperature of star on the orbital parameters of exoplanets

    Directory of Open Access Journals (Sweden)

    Pavel Pintr

    2013-05-01

    Full Text Available For 759 exoplanets detected by radial velocities method we found that distances of exoplanets from central star comply in general Schmidt law and these distances depend on the stellar surface temperature. Every stellar spectral class has a little different distribution. The Luminosity and the Irradiance has not effect on the distribution of distances of exoplanets. We have found the new formulas for calculation of effective temperature of exoplanets for spectral classes F, G, and K. These new formulas we can use for future calculation of habitable planets.

  14. [Responses of Picea likiangensis radial growth to climate change in the Small Zhongdian area of Yunnan Province, Southwest China].

    Science.gov (United States)

    Zhao, Zhi-Jiang; Tan, Liu-Yi; Kang, Dong-Wei; Liu, Qi-Jing; Li, Jun-Qing

    2012-03-01

    Picea likiangensis (Franch. ) Pritz. primary forest is one of the dominant forest types in the Small Zhongdian area in Shangri-La County of Yunnan Province. In this paper, the responses of P. likiangensis tree-ring width to climate change were analyzed by dendrochronological methods, and the dendrochronology was built by using relatively conservative detrending negative exponential curves or linear regression. Correlation analysis and response function analysis were applied to explore the relationships between the residual chronology series (RES) and climatic factors at different time scales, and pointer year analysis was used to explain the reasons of producing narrow and wide rings. In the study area, the radial growth of P. likiangensis and the increasing air temperature from 1990 to 2008 had definite 'abruption'. The temperature and precipitation in previous year growth season were the main factors limiting the present year radial growth, and especially, the temperature in previous July played a negative feedback role in the radial growth, while the sufficient precipitation in previous July promoted the radial growth. The differences in the temperature variation and precipitation variation in previous year were the main reasons for the formation of narrow and wide rings. P. likiangensis radial growth was not sensitive to the variation of PDSI.

  15. Optical emission spectroscopy of metal-halide lamps: Radially resolved atomic state distribution functions of Dy and Hg

    NARCIS (Netherlands)

    Nimalasuriya, T.; Flikweert, A.J.; Stoffels, W.W.; Haverlag, M.; Mullen, van der J.J.A.M.; Pupat, N.B.M.

    2006-01-01

    Absolute line intensity measurements are performed on a metal-halide lamp. Several transitions of atomic and ionic Dy and atomic Hg are measured at different radial positions from which we obtain absolute atomic and ionic Dy intensity profiles. From these profiles we construct the radially resolved

  16. Distributed fiber?optic temperature sensing for hydrologic systems

    NARCIS (Netherlands)

    Selker, J.S.; Thévenaz, L.; Huwald, H.; Mallet, A.; Luxemburg, W.M.J.; Van de Giesen, N.; Stejskal, M.; Zeman, J.; Westhoff, M.; Parlange, M.B.

    2006-01-01

    Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We

  17. Distributed fiber-optic temperature sensing for hydrologic systems

    NARCIS (Netherlands)

    Selker, John S.; Thévenaz, Luc; Huwald, Hendrik; Mallet, Alfred; Luxemburg, Wim; van de Giesen, Nick C.; Stejskal, Martin; Zeman, Josef; Westhoff, Martijn; Parlange, Marc B.

    2006-01-01

    Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We

  18. Tube Radial Distribution Flow Separation in a Microchannel Using an Ionic Liquid Aqueous Two-Phase System Based on Phase Separation Multi-Phase Flow.

    Science.gov (United States)

    Nagatani, Kosuke; Shihata, Yoshinori; Matsushita, Takahiro; Tsukagoshi, Kazuhiko

    2016-01-01

    Ionic liquid aqueous two-phase systems were delivered into a capillary tube to achieve tube radial distribution flow (TRDF) or annular flow in a microspace. The phase diagram, viscosity of the phases, and TRDF image of the 1-butyl-3-methylimidazolium chloride and NaOH system were examined. The TRDF was formed with inner ionic liquid-rich and outer ionic liquid-poor phases in the capillary tube. The phase configuration was explained using the viscous dissipation principle. We also examined the distribution of rhodamine B in a three-branched microchannel on a microchip with ionic liquid aqueous two-phase systems for the first time.

  19. Temperature Gradients on the Cell Wall in the Critical Viscosity Experiment

    Science.gov (United States)

    Berg, Robert F.; Moldover, Michael R.

    1993-01-01

    Because of the diverging susceptibility delta rho/delta Tau near the liquid-vapor critical point, temperature gradients must be kept small to maintain adequate sample homogeneity. In our Science Requirements Document we paid particular attention to radial density gradients caused by equilibration of the xenon sample. Axial density gradients were addressed through the requirement that the cell's copper wall have a gradient less than 22 microK/m. This report re-examines the cell wall's temperature distribution in more detail by estimating all known significant contributions to temperature differences on the cell's wall.

  20. Modeling and preliminary analysis on the temperature profile of the (TRU-Zr)-Zr dispersion fuel rod for HYPER

    International Nuclear Information System (INIS)

    Lee, B. W.; Hwang, W.; Lee, B. S.; Park, W. S.

    2000-01-01

    Either TRU-Zr metal alloy or (TRU-Zr)-Zr dispersion fuel is considered as a blanket fuel for HYPER(Hybrid Power Extraction Reactor). In order to develop the code for dispersion fuel rod performance analysis under steady state condition, the fuel temperature distribution model which is the one of the most important factors in a fuel performance code has been developed in this paper,. This developed model computes the one dimensional radial temperature distribution of a cylindrical fuel rod. The temperature profile results by this model are compared with the temperature distributions of U 3 Si-A1 dispersion fuel and TRU-Zr metal alloy fuel. This model will be installed in performance analysis code for dispersion fuel

  1. Prediction of water formation temperature in natural gas dehydrators using radial basis function (RBF neural networks

    Directory of Open Access Journals (Sweden)

    Tatar Afshin

    2016-03-01

    Full Text Available Raw natural gases usually contain water. It is very important to remove the water from these gases through dehydration processes due to economic reasons and safety considerations. One of the most important methods for water removal from these gases is using dehydration units which use Triethylene glycol (TEG. The TEG concentration at which all water is removed and dew point characteristics of mixture are two important parameters, which should be taken into account in TEG dehydration system. Hence, developing a reliable and accurate model to predict the performance of such a system seems to be very important in gas engineering operations. This study highlights the use of intelligent modeling techniques such as Multilayer perceptron (MLP and Radial Basis Function Neural Network (RBF-ANN to predict the equilibrium water dew point in a stream of natural gas based on the TEG concentration of stream and contractor temperature. Literature data set used in this study covers temperatures from 10 °C to 80 °C and TEG concentrations from 90.000% to 99.999%. Results showed that both models are accurate in prediction of experimental data and the MLP model gives more accurate predictions compared to RBF model.

  2. An investigation of characteristics of thermal stress caused by fluid temperature fluctuation at a T-junction pipe

    International Nuclear Information System (INIS)

    Miyoshi, Koji; Nakamura, Akira; Utanohara, Yoichi

    2014-01-01

    Thermal fatigue cracking may initiate at a T-junction pipe where high and low temperature fluids flow in from different directions and mix. Thermal stress is caused by a temperature gradient in a structure and by its variation. It is possible to obtain stress distributions if the temperature distributions at the pipe inner surface are obtained by experiments. The wall temperature distributions at a T-junction pipe were measured by experiments. The thermal stress distributions were calculated using the experimental data. The circumferential and axial stress fluctuations were larger than the radial stress fluctuation range. The stress fluctuation at the position of the maximum stress fluctuation had 10sec period. The distribution of the stress fluctuation was similar to that of the temperature fluctuation. The large stress fluctuations were caused by the time variation of the heating region by the hot jet flow. (author)

  3. Evaluation of Fiber Bragg Grating and Distributed Optical Fiber Temperature Sensors

    International Nuclear Information System (INIS)

    McCary, Kelly Marie

    2017-01-01

    Fiber optic temperature sensors were evaluated in the High Temperature Test Lab (HTTL) to determine the accuracy of the measurements at various temperatures. A distributed temperature sensor was evaluated up to 550C and a fiber Bragg grating sensor was evaluated up to 750C. HTTL measurements indicate that there is a drift in fiber Bragg sensor over time of approximately -10C with higher accuracy at temperatures above 300C. The distributed sensor produced some bad data points at and above 500C but produced measurements with less than 2% error at increasing temperatures up to 400C

  4. Evaluation of Fiber Bragg Grating and Distributed Optical Fiber Temperature Sensors

    Energy Technology Data Exchange (ETDEWEB)

    McCary, Kelly Marie [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-04-01

    Fiber optic temperature sensors were evaluated in the High Temperature Test Lab (HTTL) to determine the accuracy of the measurements at various temperatures. A distributed temperature sensor was evaluated up to 550C and a fiber Bragg grating sensor was evaluated up to 750C. HTTL measurements indicate that there is a drift in fiber Bragg sensor over time of approximately -10C with higher accuracy at temperatures above 300C. The distributed sensor produced some bad data points at and above 500C but produced measurements with less than 2% error at increasing temperatures up to 400C

  5. Radial Growth and Physiological Response of Coniferous Trees to Arctic Amplification

    Science.gov (United States)

    Tei, Shunsuke; Sugimoto, Atsuko; Liang, Maochang; Yonenobu, Hitoshi; Matsuura, Yojiro; Osawa, Akira; Sato, Hisashi; Fujinuma, Junichi; Maximov, Trofim

    2017-11-01

    We describe the physiological responses of boreal conifers to climate change for the past 112 years using ring-width and carbon isotope ratio (δ13C) chronologies at six forest sites in northern Eurasia and Canada. Responses differed among regions, depending on their climatic and/or geographic characteristics. Tree radial growth decreased over the past 52 years in central eastern Siberia with the higher rate of summer temperature increase than other regions, as indicated by the negative correlation between radial growth and summer temperature, but increased in northern Europe and Canada. Changes in tree-ring δ13C indicated that recent climatic conditions have induced stronger drought stress for trees from central eastern Siberia than for those from other regions. The observed tree growth trends were compared to those simulated using a dynamic global vegetation model. Although the modeled annual net primary production (NPP) for trees generally exhibited similar decadal variation to radial growth, simulations did not show a recent decrease in tree growth, even in central eastern Siberia. This was probably due to an overestimation of the sensitivity of modeled tree NPP to precipitation. Our results suggest that the tree NPP forecasted under the expected future increases in temperature and average precipitation might be overestimated, especially in severely dry regions such as central eastern Siberia.

  6. Noninvasive ultrasonic measurements of temperature distribution and heat fluxes in nuclear systems

    International Nuclear Information System (INIS)

    Jia, Yunlu; Skliar, Mikhail

    2015-01-01

    Measurements of temperature and heat fluxes through structural materials are important in many nuclear systems. One such example is dry storage casks (DSC) that are built to store highly radioactive materials, such as spent nuclear reactor fuel. The temperature inside casks must be maintained within allowable limits of the fuel assemblies and the DSC components because many degradation mechanisms are thermally controlled. In order to obtain direct, real-time measurements of temperature distribution without insertion of sensing elements into harsh environment of storage casks, we are developing noninvasive ultrasound (US) methods for measuring spatial distribution of temperature inside solid materials, such as concrete overpacks, steel casings, thimbles, and rods. The measured temperature distribution can then be used to obtain heat fluxes that provide calorimetric characterisation of the fuel decay, fuel distribution inside the cask, its integrity, and accounting of nuclear materials. The physical basis of the proposed approach is the temperature dependence of the speed of sound in solids. By measuring the time it takes an ultrasound signal to travel a known distance between a transducer and a receiver, the indication about the temperature distribution along the path of the ultrasound propagation may be obtained. However, when temperature along the path of US propagation is non-uniform, the overall time of flight of an ultrasound signal depends on the temperature distribution in a complex and unknown way. To overcome this difficulty, the central idea of our method is to create an US propagation path inside material of interest which incorporates partial ultrasound reflectors (back scatterers) at known locations and use the train of created multiple echoes to estimate the temperature distribution. In this paper, we discuss experimental validation of this approach, the achievable accuracy and spatial resolution of the measured temperature profile, and stress the

  7. A Double-Resistive Active Power Filter System to Attenuate Harmonic Voltages of a Radial Power Distribution Feeder

    DEFF Research Database (Denmark)

    Sun, Xiaofeng; Han, Ruijing; Shen, Hong

    2016-01-01

    voltages. This paper proposes a double-resistive active power filter (D-RAPF) system consisting of a terminal-RAPF and an attenuation-RAPF for each individual harmonic. The terminal-RAPF operating as the characteristic impedance of the feeder is installed at the end bus to suppress harmonic propagation......Harmonic propagation between power-factor correction capacitors and system inductors seriously deteriorates power quality in a radial power distribution feeder. Installation of a resistive active power filter (RAPF) at the end bus only suppresses harmonic propagation, not attenuates harmonic...... at all harmonic frequencies. The attenuation-RAPF, whose control gain can be set according to the requirements of the harmonic voltage distortion limit, is installed at a specific position for each individual harmonic to attenuate the corresponding harmonic voltages. The D-RAPF system not only suppresses...

  8. Impact of climate change on radial growth of Siberian spruce and Scots pine in North-western Russia

    Directory of Open Access Journals (Sweden)

    Lopatin E

    2007-01-01

    Full Text Available When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

  9. Experimental determination of the radial dose distribution in high gradient regions around 192Ir wires: Comparison of electron paramagnetic resonance imaging, films, and Monte Carlo simulations

    International Nuclear Information System (INIS)

    Kolbun, N.; Leveque, Ph.; Abboud, F.; Bol, A.; Vynckier, S.; Gallez, B.

    2010-01-01

    Purpose: The experimental determination of doses at proximal distances from radioactive sources is difficult because of the steepness of the dose gradient. The goal of this study was to determine the relative radial dose distribution for a low dose rate 192 Ir wire source using electron paramagnetic resonance imaging (EPRI) and to compare the results to those obtained using Gafchromic EBT film dosimetry and Monte Carlo (MC) simulations. Methods: Lithium formate and ammonium formate were chosen as the EPR dosimetric materials and were used to form cylindrical phantoms. The dose distribution of the stable radiation-induced free radicals in the lithium formate and ammonium formate phantoms was assessed by EPRI. EBT films were also inserted inside in ammonium formate phantoms for comparison. MC simulation was performed using the MCNP4C2 software code. Results: The radical signal in irradiated ammonium formate is contained in a single narrow EPR line, with an EPR peak-to-peak linewidth narrower than that of lithium formate (∼0.64 and 1.4 mT, respectively). The spatial resolution of EPR images was enhanced by a factor of 2.3 using ammonium formate compared to lithium formate because its linewidth is about 0.75 mT narrower than that of lithium formate. The EPRI results were consistent to within 1% with those of Gafchromic EBT films and MC simulations at distances from 1.0 to 2.9 mm. The radial dose values obtained by EPRI were about 4% lower at distances from 2.9 to 4.0 mm than those determined by MC simulation and EBT film dosimetry. Conclusions: Ammonium formate is a suitable material under certain conditions for use in brachytherapy dosimetry using EPRI. In this study, the authors demonstrated that the EPRI technique allows the estimation of the relative radial dose distribution at short distances for a 192 Ir wire source.

  10. A study on plastic strain accumulation caused by traveling of temperature distribution synchronizing with temperature rise

    International Nuclear Information System (INIS)

    Okajima, Satoshi

    2016-01-01

    The prevention of excessive deformation by thermal ratcheting is important in the design of high-temperature components of fast breeder reactors (FBR). This includes evaluation methods for a new type of thermal ratcheting caused by an axial traveling of temperature distribution, which corresponds to moving-up of liquid sodium surface in startup phase. Long range traveling of the axial temperature distribution brings flat plastic deformation profile in wide range. Therefore, at the center of this range, residual stress that brings shakedown behavior does not accumulate. As a result, repeating of this temperature traveling brings continuous accumulation of the plastic strain, even if there is no primary stress. In contrast, in the case with short range traveling, residual stress is caused by constraint against elastic part, and finally it results in shakedown. Because of this mechanism, we supposed that limit for the shakedown behavior depends on distance from the elastic part (i.e. half length of region with plastic deformation). In this paper, we examined characteristics of the accumulation of the plastic strain caused by realistic heat transients, namely, traveling of temperature distribution synchronizing with temperature rise. This examination was based on finite element analyses using elastic-perfectly plastic material. As a result, we confirmed that the shakedown limit depends not on the traveling range of the temperature distribution but the plastic deformation range, which was predicted by the elastic analysis. In the actual application, we can control the plastic deformation range by changing rate of the moving-up of liquid sodium surface. (author)

  11. A design method to isothermalize the core of high-temperature gas-cooled reactors

    International Nuclear Information System (INIS)

    Takano, M.; Sawa, K.

    1987-01-01

    A practical design method is developed to isothermalize the core of block-type high-temperature gas-cooled reactors (HTGRs). Isothermalization plays an important role in increasing the design margin on fuel temperature. In this method, the fuel enrichment and the size and boron content of the burnable poison rod are determined over the core blockwise so that the axially exponential and radially flat power distribution are kept from the beginning to the end of core life. The method enables conventional HTGRs to raise the outlet gas temperature without increasing the maximum fuel temperature

  12. Temperature distribution study in flash-annealed amorphous ribbons

    International Nuclear Information System (INIS)

    Moron, C.; Garcia, A.; Carracedo, M.T.

    2003-01-01

    Negative magnetrostrictive amorphous ribbons have been locally current annealed with currents from 1 to 8 A and annealing times from 14 ms to 200 s. In order to obtain information about the sample temperature during flash or current annealing, a study of the temperature dispersion during annealing in amorphous ribbons was made. The local temperature variation was obtained by measuring the local intensity of the infrared emission of the sample with a CCD liquid nitrogen cooled camera. A distribution of local temperature has been found in spite of the small dimension of the sample

  13. Structure, Kinematics and Origin of Radial Faults: 3D Seismic Observations from the Santos Basin, offshore Brazil

    Science.gov (United States)

    Coleman, Alexander; Jackson, Christopher A.-L.

    2017-04-01

    Salt stock growth is typically accompanied by the development of geometrically and kinematically complex fault networks in the surrounding country rock. The most common networks comprise radial faults; these are characterised by low displacement (stock into flanking strata. Radial faults are commonly observed in an arched, unpierced roof developed above a rising salt stock; in these cases, the faults are typically well-imaged seismically and likely form due to outer-arc extension during overburden stretching. Radial faults are also found at deeper structural levels, in strata flanking the diapir stem; in these cases, they are typically less well-imaged, thus their structure, kinematics and origin are less well understood. Furthermore, understanding the growth of radial faults may provide insights into hydrocarbon reservoir compartmentalisation and the evolution of neighbouring salt stocks. Here, we use high-quality 3D seismic reflection data from the Santos Basin, offshore Brazil to determine the structure and kinematics, and infer the likely origin of exceptionally well-imaged radial faults overlying and flanking a mature salt stock. Furthermore, we compare the geometric (e.g. throw, geometry, spacing, distribution etc.) and kinematic (e.g. timing of formation and duration of activity) characteristics of radial faults at both structural levels, allowing us to infer their temporal relationship and likely origins. We show that radial faults regardless of their structural level typically have aspect ratios of c. 1.8 - 2, are laterally-restricted in the vicinity of the salt, and have lengths of indices of c. 1, with low throw gradients of 0.05 - 0.1 at the upper tip indicate that radial faults were likely blind. Throws range from 5 - 80 ms, with throw-maxima within 1 - 2 radii of the salt diapir. However, we note that the position of the throw maxima is not at the same level for all radial faults. We propose that radial faults nucleate and initially grow as blind

  14. Flow-Field Characteristics of High-Temperature Annular Buoyant Jets and Their Development Laws Influenced by Ventilation System

    OpenAIRE

    Wang, Yi; Huang, Yanqiu; Liu, Jiaping; Wang, Hai; Liu, Qiuhan

    2013-01-01

    The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and veloc...

  15. The effects of off-center pellets on the temperature distribution and the heat flux distribution of fuel rods in nuclear reactors

    International Nuclear Information System (INIS)

    Peng Muzhang; Xing Jianhua

    1986-01-01

    This paper analyzes the effects of off-center pellets on the steady state temperature distribution and heat flux distribution of fuel rods in the nuclear reactors, and derives the dimensionless temperature distribution relationships and the dimensionless heat flux distribution relationship from the fuel rods with off-center pellets. The calculated results show that the effects of off-center will result in not only deviations of the highest temperature placement in the fuel pellets, but also the circumferentially nonuniform distributions of the temperatures and heat fluxes of the fuel rod surfaces

  16. Tight focusing of radially polarized circular Airy vortex beams

    Science.gov (United States)

    Chen, Musheng; Huang, Sujuan; Shao, Wei

    2017-11-01

    Tight focusing properties of radially polarized circular Airy vortex beams (CAVB) are studied numerically. The light field expressions for the focused fields are derived based on vectorial Debye theory. We also study the relationship between focal profiles, such as light intensity distribution, radius of focal spot and focal length, and the parameters of CAVB. Numerical results demonstrate that we can generate a radially polarized CAVB with super-long focal length, super-strong longitudinal intensity or subwavelength focused spot at the focal plane by properly choosing the parameters of incident light and high numerical aperture (NA) lens. These results have potential applications for optical trapping, optical storage and particle acceleration.

  17. The effect of radial migration on galactic disks

    International Nuclear Information System (INIS)

    Vera-Ciro, Carlos; D'Onghia, Elena; Navarro, Julio; Abadi, Mario

    2014-01-01

    We study the radial migration of stars driven by recurring multi-arm spiral features in an exponential disk embedded in a dark matter halo. The spiral perturbations redistribute angular momentum within the disk and lead to substantial radial displacements of individual stars, in a manner that largely preserves the circularity of their orbits and that results, after 5 Gyr (∼40 full rotations at the disk scale length), in little radial heating and no appreciable changes to the vertical or radial structure of the disk. Our results clarify a number of issues related to the spatial distribution and kinematics of migrators. In particular, we find that migrators are a heavily biased subset of stars with preferentially low vertical velocity dispersions. This 'provenance bias' for migrators is not surprising in hindsight, for stars with small vertical excursions spend more time near the disk plane, and thus respond more readily to non-axisymmetric perturbations. We also find that the vertical velocity dispersion of outward migrators always decreases, whereas the opposite holds for inward migrators. To first order, newly arrived migrators simply replace stars that have migrated off to other radii, thus inheriting the vertical bias of the latter. Extreme migrators might therefore be recognized, if present, by the unexpectedly small amplitude of their vertical excursions. Our results show that migration, understood as changes in angular momentum that preserve circularity, can strongly affect the thin disk, but cast doubts on models that envision the Galactic thick disk as a relic of radial migration.

  18. Bacterial community radial-spatial distribution in biofilms along pipe wall in chlorinated drinking water distribution system of East China.

    Science.gov (United States)

    Liu, Jingqing; Ren, Hongxing; Ye, Xianbei; Wang, Wei; Liu, Yan; Lou, Liping; Cheng, Dongqing; He, Xiaofang; Zhou, Xiaoyan; Qiu, Shangde; Fu, Liusong; Hu, Baolan

    2017-01-01

    Biofilms in the pipe wall may lead to water quality deterioration and biological instability in drinking water distribution systems (DWDSs). In this study, bacterial community radial-spatial distribution in biofilms along the pipe wall in a chlorinated DWDS of East China was investigated. Three pipes of large diameter (300, 600, and 600 mm) were sampled in this DWDS, including a ductile cast iron pipe (DCIP) with pipe age of 11 years and two gray cast iron pipes (GCIP) with pipe ages of 17 and 19 years, and biofilms in the upper, middle, and lower parts of each pipe wall were collected. Real-time quantitative polymerase chain reaction (qPCR) and culture-based method were used to quantify bacteria. 454 pyrosequencing was used for bacterial community analysis. The results showed that the biofilm density and total solid (TS) and volatile solid (VS) contents increased gradually from the top to the bottom along the pipe wall. Microorganisms were concentrated in the upper and lower parts of the pipe wall, together accounting for more than 80 % of the total biomass in the biofilms. The bacterial communities in biofilms were significantly different in different areas of the pipe wall and had no strong interaction. Compared with the upper and lower parts of the pipe wall, the bacterial community in the middle of the pipe wall was distributed evenly and had the highest diversity. The 16S rRNA genes of various possible pathogens, including Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Salmonella enterica, were detected in the biofilms, and the abundances of these possible pathogens were highest in the middle of the pipe wall among three areas. The detachment of the biofilms is the main reason for the deterioration of the water quality in DWDSs. The results of this study suggest that the biofilms in the middle of the pipe wall have highly potential risk for drinking water safety, which provides new ideas for the study of the microbial ecology in

  19. Effects of finite-β and radial electric fields on neoclassical transport in the Large Helical Device

    International Nuclear Information System (INIS)

    Kanno, R.; Nakajima, N.; Sugama, H.; Okamoto, M.; Ogawa, Y.

    1997-01-01

    Effects of finite-β and radial electric fields on the neoclassical transport in the Large Helical Device are investigated with the DKES (Drift Kinetic Equation Solver) code. In the finite-β configuration, even orbits of deeply trapped particles deviate significantly from magnetic flux surfaces. Thus, neoclassical ripple transport coefficients in the finite-β configuration are several times larger than those in the vacuum configuration under the same condition of temperatures and radial electric fields. When the plasma temperature is several keV, a bifurcation of the electric fields appears under the ambipolarity condition, and sufficient large radial electric fields can be generated. As a result, the ExB drift rectifies orbits of particles and improves significantly the transport coefficients in the finite-β configuration. (author)

  20. Intermittent electron density and temperature fluctuations and associated fluxes in the Alcator C-Mod scrape-off layer

    Science.gov (United States)

    Kube, R.; Garcia, O. E.; Theodorsen, A.; Brunner, D.; Kuang, A. Q.; LaBombard, B.; Terry, J. L.

    2018-06-01

    The Alcator C-Mod mirror Langmuir probe system has been used to sample data time series of fluctuating plasma parameters in the outboard mid-plane far scrape-off layer. We present a statistical analysis of one second long time series of electron density, temperature, radial electric drift velocity and the corresponding particle and electron heat fluxes. These are sampled during stationary plasma conditions in an ohmically heated, lower single null diverted discharge. The electron density and temperature are strongly correlated and feature fluctuation statistics similar to the ion saturation current. Both electron density and temperature time series are dominated by intermittent, large-amplitude burst with an exponential distribution of both burst amplitudes and waiting times between them. The characteristic time scale of the large-amplitude bursts is approximately 15 μ {{s}}. Large-amplitude velocity fluctuations feature a slightly faster characteristic time scale and appear at a faster rate than electron density and temperature fluctuations. Describing these time series as a superposition of uncorrelated exponential pulses, we find that probability distribution functions, power spectral densities as well as auto-correlation functions of the data time series agree well with predictions from the stochastic model. The electron particle and heat fluxes present large-amplitude fluctuations. For this low-density plasma, the radial electron heat flux is dominated by convection, that is, correlations of fluctuations in the electron density and radial velocity. Hot and dense blobs contribute only a minute fraction of the total fluctuation driven heat flux.

  1. Temperature distribution around thin electroconductive layers created on composite textile substrates

    Directory of Open Access Journals (Sweden)

    Korzeniewska Ewa

    2018-03-01

    Full Text Available In this paper, the authors describe the distribution of temperatures around electroconductive pathways created by a physical vacuum deposition process on flexible textile substrates used in elastic electronics and textronics. Cordura material was chosen as the substrate. Silver with 99.99% purity was used as the deposited metal. This research was based on thermographic photographs of the produced samples. Analysis of the temperature field around the electroconductive layer was carried out using Image ThermaBase EU software. The analysis of the temperature distribution highlights the software’s usefulness in determining the homogeneity of the created metal layer. Higher local temperatures and non-uniform distributions at the same time can negatively influence the work of the textronic system.

  2. Monte Carlo based radial shield design of typical PWR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gul, Anas; Khan, Rustam; Qureshi, M. Ayub; Azeem, Muhammad Waqar; Raza, S.A. [Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan). Dept. of Nuclear Engineering; Stummer, Thomas [Technische Univ. Wien (Austria). Atominst.

    2016-11-15

    Neutron and gamma flux and dose equivalent rate distribution are analysed in radial and shields of a typical PWR type reactor based on the Monte Carlo radiation transport computer code MCNP5. The ENDF/B-VI continuous energy cross-section library has been employed for the criticality and shielding analysis. The computed results are in good agreement with the reference results (maximum difference is less than 56 %). It implies that MCNP5 a good tool for accurate prediction of neutron and gamma flux and dose rates in radial shield around the core of PWR type reactors.

  3. Evaluation of local power distribution with fine-mesh core model for the HTTR

    International Nuclear Information System (INIS)

    Murata, Isao; Yamashita, Kiyonobu; Maruyama, So; Shindo, Ryuichi; Fujimoto, Nozomu; Sudo, Yukio; Nakata, Tetsuo.

    1991-01-01

    An evaluation method of the local power distribution was developed considering the radial and axial heterogeneity caused by fuel rods, BP rods and block end graphite for the High Temperature Engineering Test Reactor (HTTR) in Japan Atomic Energy Research Institute (JAERI). The evaluation method was verified through the analyses of critical assembly experiments. A good agreement was obtained between calculations and measurements and the difference was less than 3 % on the power distribution. This method was applied to the core design for the HTTR to evaluate the maximum fuel temperature. From these results, it was confirmed that this evaluation method has an enough accuracy and is able to predict the detailed power distribution of the HTTR. (author)

  4. Application of a proposed overcurrent relay in radial distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    Conde, A.; Vazquez, E. [Universidad Autonoma de Nuevo Leon, Facultad de Ingenieria Mecanica y Electrica, A.P. 36-F, CU, CP 66450, San Nicolas de los Garza, Nuevo Leon (Mexico)

    2011-02-15

    This paper contains the application criteria and coordination process for a proposed overcurrent relay in a radial power system with feed from one or multiple sources. This relay uses independent functions to detect faults and to calculate the operation time. Also this relay uses a time element function that allows it to reduce the time relay operation, enhancing the backup protection. Some of the proposed approaches improve the sensitivity of the relay. The selection of the best approach in the proposed relay is defined by the needs of the application. The proposed protection can be considered as an additional function protection to conventional overcurrent relays. (author)

  5. Fission rate distribution at the 84-pin radial section of a SVEA-96 Optima2 BWR assembly

    Energy Technology Data Exchange (ETDEWEB)

    Perret, Gregory; Murphy, Michael F.; Jatuff, Fabian [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Chawla, Rakesh [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2008-07-01

    Westinghouse boiling water reactor SVEA-96 Optima2 assemblies were studied during the LWRPROTEUS program at the PROTEUS facility in the Paul Scherrer Institute. Measured radial fission rate distributions at the 84-pin elevation are compared with MCNPX predictions using both ENDF/B-VI (Release 2) and JEFF-3.1 data libraries. Predicted fission rates agree within +-4.5% using both libraries. Fission rates were over-predicted in UO{sub 2} pins close to the missing 1/3 pins and under-predicted in UO{sub 2} pins close to the missing 2/3 pins. Recurrent under-estimations were observed in the UO{sub 2}-Gd{sub 2}O{sub 3} pins, for both libraries, which might be explained by over-estimated thermal cross-sections of {sup 157}Gd, as suggested in a recent work of G. Leinweber et al. (2006). (authors)

  6. The influence of collisional and anomalous radial diffusion on parallel ion transport in edge plasmas

    International Nuclear Information System (INIS)

    Helander, P.; Hazeltine, R.D.; Catto, P.J.

    1996-01-01

    The orderings in the kinetic equations commonly used to study the plasma core of a tokamak do not allow a balance between parallel ion streaming and radial diffusion, and are, therefore, inappropriate in the plasma edge. Different orderings are required in the edge region where radial transport across the steep gradients associated with the scrape-off layer is large enough to balance the rapid parallel flow caused by conditions close to collecting surfaces (such as the Bohm sheath condition). In the present work, we derive and solve novel kinetic equations, allowing for such a balance, and construct distinctive transport laws for impure, collisional, edge plasmas in which the perpendicular transport is (i) due to Coulomb collisions of ions with heavy impurities, or (ii) governed by anomalous diffusion driven by electrostatic turbulence. In both the collisional and anomalous radial transport cases, we find that one single diffusion coefficient determines the radial transport of particles, momentum and heat. The parallel transport laws and parallel thermal force in the scrape-off layer assume an unconventional form, in which the relative ion-impurity flow is driven by a combination of the conventional parallel gradients, and new (i) collisional or (ii) anomalous terms involving products of radial derivatives of the temperature and density with the radial shear of the parallel velocity. Thus, in the presence of anomalous radial diffusion, the parallel ion transport cannot be entirely classical, as usually assumed in numerical edge computations. The underlying physical reason is the appearance of a novel type of parallel thermal force resulting from the combined action of anomalous diffusion and radial temperature and velocity gradients. In highly sheared flows the new terms can modify impurity penetration into the core plasma

  7. The effects of the recent minimum temperature and water deficit increases on Pinus pinaster wood radial growth and density in southern Portugal.

    Directory of Open Access Journals (Sweden)

    Cathy Béatrice Kurz Besson

    2016-08-01

    Full Text Available Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant growth. It is not clear to what extent wood growth and density of agroforestry species have suffered from such changes or recent extreme climate events.To address this question, tree-ring width and density chronologies were built for a P. pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI multi-scalar drought index, between 1 to 24-months. The climate-growth/density relationships were evaluated for the period 1958-2011.We show that both wood radial growth and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial growth and density. Despite of the intensification of long-term water deficit, tree-ring width appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-ring density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster’s vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster’s production capacity and quality in response to more arid conditions in the near future in the region.

  8. Porous structure analysis of large-scale randomly packed pebble bed in high temperature gas-cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Cheng; Yang, Xingtuan; Liu, Zhiyong; Sun, Yanfei; Jiang, Shengyao [Tsinghua Univ., Beijing (China). Key Laboratory of Advanced Reactor Engineering and Safety; Li, Congxin [Ministry of Environmental Protection of the People' s Republic of China, Beijing (China). Nuclear and Radiation Safety Center

    2015-02-15

    A three-dimensional pebble bed corresponding to the randomly packed bed in the heat transfer test facility built for the High Temperature Reactor Pebble bed Modules (HTR-PM) in Shandong Shidaowan is simulated via discrete element method. Based on the simulation, we make a detailed analysis on the packing structure of the pebble bed from several aspects, such as transverse section image, longitudinal section image, radial and axial porosity distributions, two-dimensional porosity distribution and coordination number distribution. The calculation results show that radial distribution of porosity is uniform in the center and oscillates near the wall; axial distribution of porosity oscillates near the bottom and linearly varies along height due to effect of gravity; the average coordination number is about seven and equals to the maximum coordination number frequency. The fully established three-dimensional packing structure analysis of the pebble bed in this work is of fundamental significance to understand the flow and heat transfer characteristics throughout the pebble-bed type structure.

  9. Stress analysis in high-temperature superconductors under pulsed field magnetization

    Science.gov (United States)

    Wu, Haowei; Yong, Huadong; Zhou, Youhe

    2018-04-01

    Bulk high-temperature superconductors (HTSs) have a high critical current density and can trap a large magnetic field. When bulk superconductors are magnetized by the pulsed field magnetization (PFM) technique, they are also subjected to a large electromagnetic stress, and the resulting thermal stress may cause cracking of the superconductor due to the brittle nature of the sample. In this paper, based on the H-formulation and the law of heat transfer, we can obtain the distributions of electromagnetic field and temperature, which are in qualitative agreement with experiment. After that, based on the dynamic equilibrium equations, the mechanical response of the bulk superconductor is determined. During the PFM process, the change in temperature has a dramatic effect on the radial and hoop stresses, and the maximum radial and hoop stress are 24.2 {{MPa}} and 22.6 {{MPa}}, respectively. The mechanical responses of a superconductor for different cases are also studied, such as the peak value of the applied field and the size of bulk superconductors. Finally, the stresses are also presented for different magnetization methods.

  10. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins.

    Science.gov (United States)

    Mantzouki, Evanthia; Lürling, Miquel; Fastner, Jutta; de Senerpont Domis, Lisette; Wilk-Woźniak, Elżbieta; Koreivienė, Judita; Seelen, Laura; Teurlincx, Sven; Verstijnen, Yvon; Krztoń, Wojciech; Walusiak, Edward; Karosienė, Jūratė; Kasperovičienė, Jūratė; Savadova, Ksenija; Vitonytė, Irma; Cillero-Castro, Carmen; Budzyńska, Agnieszka; Goldyn, Ryszard; Kozak, Anna; Rosińska, Joanna; Szeląg-Wasielewska, Elżbieta; Domek, Piotr; Jakubowska-Krepska, Natalia; Kwasizur, Kinga; Messyasz, Beata; Pełechaty, Aleksandra; Pełechaty, Mariusz; Kokocinski, Mikolaj; García-Murcia, Ana; Real, Monserrat; Romans, Elvira; Noguero-Ribes, Jordi; Duque, David Parreño; Fernández-Morán, Elísabeth; Karakaya, Nusret; Häggqvist, Kerstin; Demir, Nilsun; Beklioğlu, Meryem; Filiz, Nur; Levi, Eti E.; Iskin, Uğur; Bezirci, Gizem; Tavşanoğlu, Ülkü Nihan; Özhan, Koray; Gkelis, Spyros; Panou, Manthos; Fakioglu, Özden; Avagianos, Christos; Kaloudis, Triantafyllos; Çelik, Kemal; Yilmaz, Mete; Marcé, Rafael; Catalán, Nuria; Bravo, Andrea G.; Buck, Moritz; Colom-Montero, William; Mustonen, Kristiina; Pierson, Don; Yang, Yang; Raposeiro, Pedro M.; Gonçalves, Vítor; Antoniou, Maria G.; Tsiarta, Nikoletta; McCarthy, Valerie; Perello, Victor C.; Feldmann, Tõnu; Laas, Alo; Panksep, Kristel; Tuvikene, Lea; Gagala, Ilona; Mankiewicz-Boczek, Joana; Yağcı, Meral Apaydın; Çınar, Şakir; Çapkın, Kadir; Yağcı, Abdulkadir; Cesur, Mehmet; Bilgin, Fuat; Bulut, Cafer; Uysal, Rahmi; Obertegger, Ulrike; Boscaini, Adriano; Flaim, Giovanna; Salmaso, Nico; Cerasino, Leonardo; Richardson, Jessica; Visser, Petra M.; Verspagen, Jolanda M. H.; Karan, Tünay; Soylu, Elif Neyran; Maraşlıoğlu, Faruk; Napiórkowska-Krzebietke, Agnieszka; Ochocka, Agnieszka; Pasztaleniec, Agnieszka; Antão-Geraldes, Ana M.; Vasconcelos, Vitor; Morais, João; Vale, Micaela; Köker, Latife; Akçaalan, Reyhan; Albay, Meriç; Špoljarić Maronić, Dubravka; Stević, Filip; Žuna Pfeiffer, Tanja; Fonvielle, Jeremy; Straile, Dietmar; Rothhaupt, Karl-Otto; Hansson, Lars-Anders; Urrutia-Cordero, Pablo; Bláha, Luděk; Geriš, Rodan; Fránková, Markéta; Koçer, Mehmet Ali Turan; Alp, Mehmet Tahir; Remec-Rekar, Spela; Elersek, Tina; Triantis, Theodoros; Zervou, Sevasti-Kiriaki; Hiskia, Anastasia; Haande, Sigrid; Skjelbred, Birger; Madrecka, Beata; Nemova, Hana; Drastichova, Iveta; Chomova, Lucia; Edwards, Christine; Sevindik, Tuğba Ongun; Tunca, Hatice; Önem, Burçin; Aleksovski, Boris; Krstić, Svetislav; Vucelić, Itana Bokan; Nawrocka, Lidia; Salmi, Pauliina; Machado-Vieira, Danielle; de Oliveira, Alinne Gurjão; Delgado-Martín, Jordi; García, David; Cereijo, Jose Luís; Gomà, Joan; Trapote, Mari Carmen; Vegas-Vilarrúbia, Teresa; Obrador, Biel; Grabowska, Magdalena; Karpowicz, Maciej; Chmura, Damian; Úbeda, Bárbara; Gálvez, José Ángel; Özen, Arda; Christoffersen, Kirsten Seestern; Warming, Trine Perlt; Kobos, Justyna; Mazur-Marzec, Hanna; Pérez-Martínez, Carmen; Ramos-Rodríguez, Eloísa; Arvola, Lauri; Alcaraz-Párraga, Pablo; Toporowska, Magdalena; Pawlik-Skowronska, Barbara; Niedźwiecki, Michał; Pęczuła, Wojciech; Leira, Manel; Hernández, Armand; Moreno-Ostos, Enrique; Blanco, José María; Rodríguez, Valeriano; Montes-Pérez, Jorge Juan; Palomino, Roberto L.; Rodríguez-Pérez, Estela; Carballeira, Rafael; Camacho, Antonio; Picazo, Antonio; Rochera, Carlos; Santamans, Anna C.; Ferriol, Carmen; Romo, Susana; Soria, Juan Miguel; Dunalska, Julita; Sieńska, Justyna; Szymański, Daniel; Kruk, Marek; Kostrzewska-Szlakowska, Iwona; Jasser, Iwona; Žutinić, Petar; Gligora Udovič, Marija; Plenković-Moraj, Anđelka; Frąk, Magdalena; Bańkowska-Sobczak, Agnieszka; Wasilewicz, Michał; Özkan, Korhan; Maliaka, Valentini; Kangro, Kersti; Grossart, Hans-Peter; Paerl, Hans W.; Carey, Cayelan C.; Ibelings, Bas W.

    2018-04-13

    Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

  11. Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins

    Directory of Open Access Journals (Sweden)

    Evanthia Mantzouki

    2018-04-01

    Full Text Available Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins. Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a and cytotoxins (e.g., cylindrospermopsin due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.

  12. NUMERICAL EVALUATION OF TEMPERATURE DISTRIBUTION IN THE ROLLING MILL ROLLS

    Directory of Open Access Journals (Sweden)

    José Claudino de Lira Júnior

    2013-06-01

    Full Text Available In hot rolling processes occur changes in the profile of the rolling mill rolls (expansion and contraction and constant wear due to mechanical stress and continuous thermal cycles of heating/cooling caused by contact rolled material- working roll and the cooling system by water jets in their surface, decreasing their lifetime. This paper presents a computational model to simulate the thermal performance of rolling mill rolls. The model was developed using the finite volume method for a transient two-dimensional system and allows calculating the temperature distribution of the rolling mill rolls under various conditions of service. Here it is investigated the influence of flow rate and temperature of the cooling water on the temperature distribution. The results show that the water temperature has greater influence than the water flow to control the surface temperature of the cylinders.

  13. The influence of a non-uniform radial temperature distribution in the fuel on the results of calculation of transients

    International Nuclear Information System (INIS)

    Goltsev, A.O.; Davidenko, V.D.; Tsibulsky, V.F.; Lekomtsev, A.A.

    2003-01-01

    The paper is devoted to the discussion of results of computational studies of transients for different ways of accounting the temperature of the fuel in the full-scale comprehensive calculations of neutron physics. The paper demonstrates that in calculation of the neutron physics, it is necessary to use the effective temperature of the fuel in order to provide for correct accounting of the fuel temperature feedback, since the value of volume-averaged temperature being used in calculations of neutron physics with feedbacks would result in underestimation of consequences of accidents, especially accidents involving the dispersion of radiation

  14. Radial super-resolution in digital holographic microscopy using structured illumination with circular symmetry

    Science.gov (United States)

    Yin, Yujian; Su, Ping; Ma, Jianshe

    2018-01-01

    A method to improve the radial resolution using special structured light is proposed in the field of digital holographic microscopy (DHM). A specimen is illuminated with circular symmetrical structured light that makes the spectrum have radial movement, so that high frequency components of the specimen are moved into the passband of the receiver to overcome the diffraction limit. In the DHM imaging system, Computer Generated Hologram (CGH) technology is used to generate the required structured light grating. Then the grating is loaded into a spatial light modulator (SLM) to obtain specific structured illumination. After recording the hologram, digital reconstruction, for the microstructure of a binary optical element that needs to observe radial distribution, the radial resolution of the specimen is improved experimentally compare it with the result of one-dimensional sinusoidal structured light imaging. And a method of designing structured light is presented.

  15. Research and development of asymmetrical heat transfer augmentation method in radial channels of blades for high temperature gas turbines

    Science.gov (United States)

    Shevchenko, I. V.; Rogalev, A. N.; Garanin, I. V.; Vegera, A. N.; Kindra, V. O.

    2017-11-01

    The serpentine-like one and half-pass cooling channel systems are primarily used in blades fabricated by the lost-wax casting process. The heat transfer turbulators like cross-sectional or angled ribs used in channels of the midchord region failed to eliminate the temperature irregularity from the suction and pressure sides, which is reaching 200°C for a first stage blade of the high-pressure turbine for an aircraft engine. This paper presents the results of a numerical and experimental test of an advanced heat transfer augmentation system in radial channels developed for alignment of the temperature field from the suction and pressure sides. A numerical simulation of three-dimensional coolant flow for a wide range of Reynolds numbers was carried out using ANSYS CFX software. Effect of geometrical parameters on the heat removal asymmetry was determined. The test results of a blade with the proposed intensification system conducted in a liquid-metal thermostat confirmed the accuracy of calculations. Based on the experimental data, the dependencies for calculation of heat transfer coefficients to the cooling air in the blade studied were obtained.

  16. Whistler waves with electron temperature anisotropy and non-Maxwellian distribution functions

    Directory of Open Access Journals (Sweden)

    M. Usman Malik

    2018-05-01

    Full Text Available The previous works on whistler waves with electron temperature anisotropy narrated the dependence on plasma parameters, however, they did not explore the reasons behind the observed differences. A comparative analysis of the whistler waves with different electron distributions has not been made to date. This paper attempts to address both these issues in detail by making a detailed comparison of the dispersion relations and growth rates of whistler waves with electron temperature anisotropy for Maxwellian, Cairns, kappa and generalized (r, q distributions by varying the key plasma parameters for the problem under consideration. It has been found that the growth rate of whistler instability is maximum for flat-topped distribution whereas it is minimum for the Maxwellian distribution. This work not only summarizes and complements the previous work done on the whistler waves with electron temperature anisotropy but also provides a general framework to understand the linear propagation of whistler waves with electron temperature anisotropy that is applicable in all regions of space plasmas where the satellite missions have indicated their presence.

  17. Operating cost minimization of a radial distribution system in a deregulated electricity market through reconfiguration using NSGA method

    International Nuclear Information System (INIS)

    Chandramohan, S.; Atturulu, Naresh; Devi, R.P. Kumudini; Venkatesh, B.

    2010-01-01

    In the future, mechanisms for trade in ancillary services such as reactive power will be implemented in many deregulated power systems. In such an operating framework, a Distribution Corporation (DisCo) would have to purchase reactive power along with real power from the connected transmission corporation. A DisCo would want to minimize its operating costs by minimizing the total amount of real and reactive power drawn from the connected transmission system. Optimally reconfiguring the network will achieve such a goal. In this work, we use a non-dominated sorting genetic algorithm (NSGA) for reconfiguring a radial DisCo to minimize its operating costs considering real and reactive power costs while maximizing its operating reliability and satisfying the regular operating constraints. This method is tested on sample test systems and reported. (author)

  18. Radial dose distribution from carbon ion incident on liquid water

    International Nuclear Information System (INIS)

    Scifoni, E.; Surdutovich, E.; Solov'yov, A.V.; Surdutovich, E.

    2010-01-01

    We report calculations of the radial dose deposited along carbon-ion tracks in liquid water using different techniques depending on the energy range of secondary electrons. The models are developed in relation with the experimental data on electron penetration lengths. For electrons with energies higher than 45 eV, we use the Katz model. However, the main focus is on the low-energy electrons, which are largely responsible for DNA damage within 10 nm from the tracks. For these electrons, the dose calculation is based on their random walk behaviour. The results of this combined approach are compared to experimental measurements. Contributions to the deposited energy by electrons of different ranges of energy are discussed. (authors)

  19. Heat transfer and temperature distribution in fuel

    International Nuclear Information System (INIS)

    Katanic-Popovic, J.; Stevanovic, M.

    1966-01-01

    This paper describes methods and procedures for determining the integral, mean and effective heat conductivity and temperature distribution in fuel, with the experimental solutions for measuring these parameters. A procedure for measuring the integral conductivity by measuring the power generated in the fuel is given [sr

  20. Radial nerve palsy in mid/distal humeral fractures: is early exploration effective?

    Science.gov (United States)

    Keighley, Geffrey; Hermans, Deborah; Lawton, Vidya; Duckworth, David

    2018-03-01

    Radial nerve palsies are a common complication with displaced distal humeral fractures. This case series examines the outcomes of early operative exploration and decompression of the nerve with fracture fixation with the view that this provides a solid construct for optimisation of nerve recovery. A total of 10 consecutive patients with a displaced distal humeral fracture and an acute radial nerve palsy were treated by the senior author by open reduction and internal fixation of the distal humerus and exploration and decompression of the radial nerve. Motor function and sensation of the radial nerve was assessed in the post-operative period every 2 months or until full recovery of the radial nerve function had occurred. All patients (100%) had recovery of motor and sensation function of their upper limb in the radial nerve distribution over a 12-month period. Recovery times ranged between 4 and 32 weeks, with the median time to recovery occurring at 26 weeks and the average time to full recovery being 22.9 weeks. Wrist extension recovered by an average of 3 months (range 2-26 weeks) and then finger extension started to recover 2-6 weeks after this. Disability of the arm, shoulder and hand scores ranged from 0 to 11.8 at greater than 1 year post-operatively. Our study demonstrated that early operative exploration of the radial nerve when performing an open stabilization of displaced distal humeral fractures resulted in a 100% recovery of the radial nerve. © 2017 Royal Australasian College of Surgeons.

  1. Dual – Temperature Electron distribution in a Laboratory Plasma ...

    African Journals Online (AJOL)

    The dual-temperature distribution function is used to investigate theoretically the effect of a perturbation of Maxwell distribution function on density ratios in a laboratory plasma produced solely by collision. By assuming a foreknowledge of collision coefficients and cross-sections and an atomic model which sets at two ...

  2. Possible causes of the recent rapid increase in the radial increment of silver fir in the Western Carpathians

    International Nuclear Information System (INIS)

    Bošeľa, Michal; Petráš, Rudolf; Sitková, Zuzana; Priwitzer, Tibor; Pajtík, Jozef; Hlavatá, Helena; Sedmák, Róbert; Tobin, Brian

    2014-01-01

    Silver fir is one of the most productive and ecologically valuable native European tree species, however, it has been experiencing decline which has periodically occurred over its natural range. This paper aims to investigate the recent climate–growth relationships of silver fir (Abies alba Mill.) and its temporal change along the course of its life. Long-term tree-ring databases, as well as records on climate, atmospheric SO 2 , NO 3 and acid concentrations from four different regions in the Western Carpathians were used. The results provide clear evidence of significant increase of silver fir's radial increment over the entire Western Carpathian area since 1970–1980. The results indicated that the most probable factors behind the rapid recovery of tree radial increment were reductions in emissions of NO 3 and SO 2 , alongside a significant increase in mean June, July and April temperatures. Highlights: • Silver fir radial growth was mostly related to mean month late winter temperatures. • Silver fir growth also responded to summer, especially July temperatures. • Strength of the climate–growth response has gradually increased since 1960–1980. • SO 2 , NO 3 , and recent climate change as major factor of the rapid radial growth recovery. -- Reductions of SO 2 and NO 3 emission along with climate change are the major causes of the recent recovery of Silver fir radial growth

  3. Developing equivalent circuits for radial distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    Prada, Ricardo; Coelho, Agnelo; Rodrigues, Anselmo [Catholic University of Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. of Electrical Engineering], Emails: prada@ele.puc-rio.br, agnelo@ele.puc-rio.br, nebulok_99@yahoo.com; Silva, Maria da Guia da [Federal University of Maranhao, Sao Luiz, MA (Brazil). Dept. of Electrical Engineering

    2009-07-01

    This paper presents a method for evaluating External Equivalent in Electric Distribution Networks (EDN).The proposed method has as its main objectives the reduction of the computational costs in distribution network reconfiguration, investigation of the optimal allocation of banks of capacitors, investigation of the allocation of distributed generation, etc. In these sorts of problems a large number of alternative projects must be assessed in order to identify the optimal solution. The optimal solution comes up with the voltage level in the load points within specified limits. Consequently, the EDN must retain the external network load points but without major increasing in the dimension of the equivalent circuit. The proposed method has been tested and validated in a substation of the Electricity Utility of Maranhao - CEMAR, in Brazil. (author)

  4. Tuning Nanocrystal Surface Depletion by Controlling Dopant Distribution as a Route Toward Enhanced Film Conductivity

    Science.gov (United States)

    Staller, Corey M.; Robinson, Zachary L.; Agrawal, Ankit; Gibbs, Stephen L.; Greenberg, Benjamin L.; Lounis, Sebastien D.; Kortshagen, Uwe R.; Milliron, Delia J.

    2018-05-01

    Electron conduction through bare metal oxide nanocrystal (NC) films is hindered by surface depletion regions resulting from the presence of surface states. We control the radial dopant distribution in tin-doped indium oxide (ITO) NCs as a means to manipulate the NC depletion width. We find in films of ITO NCs of equal overall dopant concentration that those with dopant-enriched surfaces show decreased depletion width and increased conductivity. Variable temperature conductivity data shows electron localization length increases and associated depletion width decreases monotonically with increased density of dopants near the NC surface. We calculate band profiles for NCs of differing radial dopant distributions and, in agreement with variable temperature conductivity fits, find NCs with dopant-enriched surfaces have narrower depletion widths and longer localization lengths than those with dopant-enriched cores. Following amelioration of NC surface depletion by atomic layer deposition of alumina, all films of equal overall dopant concentration have similar conductivity. Variable temperature conductivity measurements on alumina-capped films indicate all films behave as granular metals. Herein, we conclude that dopant-enriched surfaces decrease the near-surface depletion region, which directly increases the electron localization length and conductivity of NC films.

  5. Influence of absorbed pump profile on the temperature distribution ...

    Indian Academy of Sciences (India)

    2017-01-20

    Jan 20, 2017 ... influence of profile width and super-Gaussian exponent of the profile on temperature distribution are investigated. Consequently, the profile width turns out to have a greater influence on the temperature compared to the type of the profile. Keywords. Side-pumped laser rod; pump cavity; absorbed pump ...

  6. Influence of temperature rise distribution in second harmonic generation crystal on intensity distributions of output second harmonic wave

    International Nuclear Information System (INIS)

    Li Wei; Feng Guoying; Li Gang; Huang Yu; Zhang Qiuhui

    2009-01-01

    Second-harmonic generation (SHG) of high-intensity laser with an SHG crystal for type I angle phase matching has been studied by the use of a split-step algorithm based on the fast Fourier transform and a fourth-order Runge-Kutta (R-K) integrator. The transverse walk-off effect, diffraction, the second-order and the third-order nonlinear effects have been taken into consideration. Influences of a temperature rise distribution of the SHG crystal on the refractive indices of ordinary wave and extraordinary wave have been discussed. The rules of phase mismatching quantity, intensity distribution of output beam and frequency conversion efficiency varying with the temperature rise distribution of the SHG crystal have been analyzed quantitatively. The calculated results indicate that in a high power frequency conversion system, the temperature rise distribution of SHG crystal would result in the phase mismatching of fundamental and harmonic waves, leading to the variation of intensity distribution of the output beam and the decrease of the conversion efficiency. (authors)

  7. Radial electrical field effects in TJ-II. (Preliminary study)

    International Nuclear Information System (INIS)

    Guasp, J.

    1996-01-01

    The influence of the radial electric field upon the neoclassical transport coefficients of TJ-II helical axis Stellarator has been calculated as well on the microwave heating stage (ECRH) as on the neutral injection one (NBI). The influence of the solutions for the self-consistent ambipolar field on confinement times and temperatures has been studied by means of a zero-dimensional energy balance. The simultaneous presence of two roots, the electronic and the ionic one, is observed for the ECRH phase, while for NBI only the ionic root appears, although with a strong field intensity that could produce a favourable effect on confinement. The interest and need of the extension of these calculations to include radial profile effects by using spatial dependent transport codes in stressed

  8. Three-dimensional fuel pin model validation by prediction of hydrogen distribution in cladding and comparison with experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aly, A. [North Carolina State Univ., Raleigh, NC (United States); Avramova, Maria [North Carolina State Univ., Raleigh, NC (United States); Ivanov, Kostadin [Pennsylvania State Univ., University Park, PA (United States); Motta, Arthur [Pennsylvania State Univ., University Park, PA (United States); Lacroix, E. [Pennsylvania State Univ., University Park, PA (United States); Manera, Annalisa [Univ. of Michigan, Ann Arbor, MI (United States); Walter, D. [Univ. of Michigan, Ann Arbor, MI (United States); Williamson, R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gamble, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-10-29

    To correctly describe and predict this hydrogen distribution there is a need for multi-physics coupling to provide accurate three-dimensional azimuthal, radial, and axial temperature distributions in the cladding. Coupled high-fidelity reactor-physics codes with a sub-channel code as well as with a computational fluid dynamics (CFD) tool have been used to calculate detailed temperature distributions. These high-fidelity coupled neutronics/thermal-hydraulics code systems are coupled further with the fuel-performance BISON code with a kernel (module) for hydrogen. Both hydrogen migration and precipitation/dissolution are included in the model. Results from this multi-physics analysis is validated utilizing calculations of hydrogen distribution using models informed by data from hydrogen experiments and PIE data.

  9. Antiproton compression and radial measurements

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jorgensen, L V; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page R D; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; Van der Werf, D P; Wurtele, J S; Yamazaki, Y

    2008-01-01

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  10. Radial, sideward and elliptic flow at AGS energies

    Indian Academy of Sciences (India)

    the sideward flow, the elliptic flow and the radial transverse mass distribution of protons data at. AGS energies. In order to ... data on both sideward and elliptic flow, NL3 model is better at 2 A¡GeV, while NL23 model is at 4–8. A¡GeV. ... port approach RBUU which is based on a coupled set of covariant transport equations for.

  11. CONSTRAINTS ON THE RADIAL VARIATION OF GRAIN GROWTH IN THE AS 209 CIRCUMSTELLAR DISK

    International Nuclear Information System (INIS)

    Pérez, Laura M.; Carpenter, John M.; Isella, Andrea; Ricci, Luca; Sargent, Anneila I.; Chandler, Claire J.; Andrews, Sean M.; Harris, Robert J.; Calvet, Nuria; Corder, Stuartt A.; Deller, Adam T.; Dullemond, Cornelis P.; Linz, Hendrik; Greaves, Jane S.; Henning, Thomas; Kwon, Woojin; Lazio, Joseph; Mundy, Lee G.; Storm, Shaye; Testi, Leonardo

    2012-01-01

    We present dust continuum observations of the protoplanetary disk surrounding the pre-main-sequence star AS 209, spanning more than an order of magnitude in wavelength from 0.88 to 9.8 mm. The disk was observed with subarcsecond angular resolution (0.''2-0.''5) to investigate radial variations in its dust properties. At longer wavelengths, the disk emission structure is notably more compact, providing model-independent evidence for changes in the grain properties across the disk. We find that physical models which reproduce the disk emission require a radial dependence of the dust opacity κ ν . Assuming that the observed wavelength-dependent structure can be attributed to radial variations in the dust opacity spectral index (β), we find that β(R) increases from β 1.5 for R ∼> 80 AU, inconsistent with a constant value of β across the disk (at the 10σ level). Furthermore, if radial variations of κ ν are caused by particle growth, we find that the maximum size of the particle-size distribution (a max ) increases from submillimeter-sized grains in the outer disk (R ∼> 70 AU) to millimeter- and centimeter-sized grains in the inner disk regions (R ∼ max (R) with predictions from physical models of dust evolution in protoplanetary disks. For the dust composition and particle-size distribution investigated here, our observational constraints on a max (R) are consistent with models where the maximum grain size is limited by radial drift.

  12. Investigations on 3-dimensional temperature distribution in a FLATCON-type CPV module

    Science.gov (United States)

    Wiesenfarth, Maike; Gamisch, Sebastian; Kraus, Harald; Bett, Andreas W.

    2013-09-01

    The thermal flow in a FLATCON®-type CPV module is investigated theoretically and experimentally. For the simulation a model in the computational fluid dynamics (CFD) software SolidWorks Flow Simulation was established. In order to verify the simulation results the calculated and measured temperatures were compared assuming the same operating conditions (wind speed and direction, direct normal irradiance (DNI) and ambient temperature). Therefore, an experimental module was manufactured and equipped with temperature sensors at defined positions. In addition, the temperature distribution on the back plate of the module was displayed by infrared images. The simulated absolute temperature and the distribution compare well with an average deviation of only 3.3 K to the sensor measurements. Finally, the validated model was used to investigate the influence of the back plate material on the temperature distribution by replacing the glass material by aluminum. The simulation showed that it is important to consider heat dissipation by radiation when designing a CPV module.

  13. Estimation of temperature distribution in a reactor shield

    International Nuclear Information System (INIS)

    Agarwal, R.A.; Goverdhan, P.; Gupta, S.K.

    1989-01-01

    Shielding is provided in a nuclear reactor to absorb the radiations emanating from the core. The energy of these radiations appear in the form of heat. Concrete which is commonly used as a shielding material in nuclear power plants must be able to withstand the temperatures and temperature gradients appearing in the shield due to this heat. High temperatures lead to dehydration of the concrete and in turn reduce the shielding effectiveness of the material. Adequate cooling needs to be provided in these shields in order to limit the maximum temperature. This paper describes a method to estimate steady state and transient temperature distribution in reactor shields. The results due to loss of coolant in the coolant tubes have been studied and presented in the paper. (author). 5 figs

  14. Benchmark numerical solutions for radiative heat transfer in two-dimensional medium with graded index distribution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L.H. [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China)]. E-mail: lhliu@hit.edu.cn

    2006-11-15

    In graded index media, the ray goes along a curved path determined by Fermat principle. Generally, the curved ray trajectory in graded index media is a complex implicit function, and the curved ray tracing is very difficult and complex. Only for some special refractive index distributions, the curved ray trajectory can be expressed as a simple explicit function. Two important examples are the layered and the radial graded index distributions. In this paper, the radiative heat transfer problems in two-dimensional square semitransparent with layered and radial graded index distributions are analyzed. After deduction of the ray trajectory, the radiative heat transfer problems are solved by using the Monte Carlo curved ray-tracing method. Some numerical solutions of dimensionless net radiative heat flux and medium temperature are tabulated as the benchmark solutions for the future development of approximation techniques for multi-dimensional radiative heat transfer in graded index media.

  15. On radial flow between parallel disks

    International Nuclear Information System (INIS)

    Wee, A Y L; Gorin, A

    2015-01-01

    Approximate analytical solutions are presented for converging flow in between two parallel non rotating disks. The static pressure distribution and radial component of the velocity are developed by averaging the inertial term across the gap in between parallel disks. The predicted results from the first approximation are favourable to experimental results as well as results presented by other authors. The second approximation shows that as the fluid approaches the center, the velocity at the mid channel slows down which is due to the struggle between the inertial term and the flowrate. (paper)

  16. Methods for Prediction of Temperature Distribution in Flashover Caused by Backdraft Fire

    Directory of Open Access Journals (Sweden)

    Guowei Zhang

    2014-01-01

    Full Text Available Accurately predicting temperature distribution in flashover fire is a key issue for evacuation and fire-fighting. Now many good flashover fire experiments have be conducted, but most of these experiments are proceeded in enclosure with fixed openings; researches on fire development and temperature distribution in flashover caused by backdraft fire did not receive enough attention. In order to study flashover phenomenon caused by backdraft fire, a full-scale fire experiment was conducted in one abandoned office building. Process of fire development and temperature distribution in room and corridor were separately recorded during the experiment. The experiment shows that fire development in enclosure is closely affected by the room ventilation. Unlike existing temperature curves which have only one temperature peak, temperature in flashover caused by backdraft may have more than one peak value and that there is a linear relationship between maximum peak temperature and distance away from fire compartment. Based on BFD curve and experimental data, mathematical models are proposed to predict temperature curve in flashover fire caused by backdraft at last. These conclusions and experiment data obtained in this paper could provide valuable reference to fire simulation, hazard assessment, and fire protection design.

  17. Fluid flow distribution optimization for minimizing the peak temperature of a tubular solar receiver

    International Nuclear Information System (INIS)

    Wei, Min; Fan, Yilin; Luo, Lingai; Flamant, Gilles

    2015-01-01

    High temperature solar receiver is a core component of solar thermal power plants. However, non-uniform solar irradiation on the receiver walls and flow maldistribution of heat transfer fluid inside the tubes may cause the excessive peak temperature, consequently leading to the reduced lifetime. This paper presents an original CFD (computational fluid dynamics)-based evolutionary algorithm to determine the optimal fluid distribution in a tubular solar receiver for the minimization of its peak temperature. A pressurized-air solar receiver comprising of 45 parallel tubes subjected to a Gaussian-shape net heat flux absorbed by the receiver is used for study. Two optimality criteria are used for the algorithm: identical outlet fluid temperatures and identical temperatures on the centerline of the heated surface. The influences of different filling materials and thermal contact resistances on the optimal fluid distribution and on the peak temperature reduction are also evaluated and discussed. Results show that the fluid distribution optimization using the algorithm could minimize the peak temperature of the receiver under the optimality criterion of identical temperatures on the centerline. Different shapes of optimal fluid distribution are determined for various filling materials. Cheap material with low thermal conductivity can also meet the peak temperature threshold through optimizing the fluid distribution. - Highlights: • A 3D pressurized-air solar receiver based on the tube-in-matrix concept is studied. • An original evolutionary algorithm is developed for fluid distribution optimization. • A new optimality criterion is proposed for minimizing the receiver peak temperature. • Different optimal fluid distributions are determined for various filling materials. • Filling material with high thermal conductivity is more favorable in practical use.

  18. Two-dimensional distribution of electron temperature in ergodic layer of LHD measured from line intensity ratio of CIV and NeVIII

    International Nuclear Information System (INIS)

    Wang, Erhui; Morita, Shigeru; Goto, Motoshi; Murakami, Izumi; Oishi, Tetsutarou; Dong, Chunfeng

    2013-01-01

    Two-dimensional distribution of impurity lines emitted from ergodic layer with stochastic magnetic field lines in Large Helical Device (LHD) has been observed using a space-resolved extreme ultraviolet (EUV) spectrometer. The two-dimensional electron temperature distribution in the ergodic layer is successfully measured using the line intensity ratio of Li-like NeVIII 2s-3p ( 2 S 1/2 - 2 P 3/2 : 88.09 Å, 2 S 1/2 - 2 P 1/2 : 88.13 Å) to 2p-3s ( 2 P 1/2 - 2 S 1/2 : 102.91 Å, 2 P 3/2 - 2 S 1/2 : 103.09 Å) transitions emitted from radial location near Last Closed Flux Surface (LCFS). The intensity ratio analyzed with ADAS code shows no dependence on the electron density below 10 14 cm -3 . The result indicates a little higher temperature, i.e., 220 eV, in the poloidal location at high-field side near helical coils called O-point compared to the temperature near X-point, i.e., 170 eV. The electron temperature profile is also measured at the edge boundary of ergodic layer using the line intensity ratio of Li-like CIV 2p-3d ( 2 P 1/2 - 2 D 3/2 : 384.03 Å, 2 P 3/2 - 2 D 5/2 : 384.18 Å) to 2p-3s ( 2 P 1/2 - 2 S 1/2 : 419.53 Å, 2 P 3/2 - 2 S 1/2 : 419.71 Å) transitions. The intensity ratios analyzed with CHIANTI, ADAS and T.Kawachi codes show a slightly higher temperature near O-point, i.e., 25 eV for CHIANTI, 21 eV for ADAS and 11 eV for T.Kawachi's codes, compared to the temperature at X-point, i.e., 15 - 21 eV for CHIANTI, 9 - 15 eV for ADAS and 6 - 9 eV for T.Kawachi codes. It suggests that the transport coefficient in the ergodic layer is varied with three-dimensional structure. (author)

  19. Stability of radial swirl flows

    International Nuclear Information System (INIS)

    Dou, H S; Khoo, B C

    2012-01-01

    The energy gradient theory is used to examine the stability of radial swirl flows. It is found that the flow of free vortex is always stable, while the introduction of a radial flow will induce the flow to be unstable. It is also shown that the pure radial flow is stable. Thus, there is a flow angle between the pure circumferential flow and the pure radial flow at which the flow is most unstable. It is demonstrated that the magnitude of this flow angle is related to the Re number based on the radial flow rate, and it is near the pure circumferential flow. The result obtained in this study is useful for the design of vaneless diffusers of centrifugal compressors and pumps as well as other industrial devices.

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

    Science.gov (United States)

    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.

  1. Temperature distribution in a cigarette oven during baking

    Directory of Open Access Journals (Sweden)

    Zhang Qing

    2015-01-01

    Full Text Available Baking treatment is one of the most important processes of cigarette production, which can significantly enhance quality of tobacco. Theoretical and numerical investigation on temperature distribution in a cigarette oven during baking was carried out. The finite volume method was used to simulate the flow field. The relationship between the uniformity of temperature field and impeller’s speed was given finally, which is helpful to optimize cigarette oven with better quality and less energy consumption.

  2. Measurement of temperature distributions in large pool fires with the use of directional flame thermometers

    International Nuclear Information System (INIS)

    Koski, Jorman A.

    2000-01-01

    Temperatures inside the flame zone of large regulatory pool fires measured during tests of radioactive materials packages vary widely with both time and position. Measurements made with several Directional Flame Thermometers, in which a thermocouple is attached to a thin metal sheet that quickly approaches flame temperatures, have been used to construct fire temperature distributions and cumulative probability distributions. As an aid to computer simulations of these large fires, these distributions are presented. The distributions are constructed by sorting fire temperature data into bins 10 C wide. A typical fire temperature distribution curve has a gradual increase starting at about 600 C, with the number of observations increasing to a peak near 1000 C, followed by an abrupt decrease in frequency, with no temperatures observed above 1200 C

  3. Simulation of Temperature Field Distribution for Cutting the Temperated Glass by Ultraviolet Laser

    Science.gov (United States)

    Yang, B. J.; He, Y. C.; Dai, F.; Lin, X. C.

    2017-03-01

    The finite element software ANSYS was adopted to simulate the temperature field distribution for laser cutting tempered glass, and the influence of different process parameters, including laser power, glass thickness and cutting speed, on temperature field distribution was studied in detail. The results show that the laser power has a greater influence on temperature field distribution than other paremeters, and when the laser power gets to 60W, the highest temperature reaches 749°C, which is higher than the glass softening temperature. It reflects the material near the laser spot is melted and the molten slag is removed by the high-energy water beam quickly. Finally, through the water guided laser cutting tempered glass experiment the FEM theoretical analysis was verified.

  4. PROBING THE ROLE OF DYNAMICAL FRICTION IN SHAPING THE BSS RADIAL DISTRIBUTION. I. SEMI-ANALYTICAL MODELS AND PRELIMINARY N-BODY SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Miocchi, P.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E.; Alessandrini, E. [Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Pasquato, M.; Lee, Y.-W. [Department of Astronomy and Center for Galaxy Evolution Research, Yonsei University, Seoul 120-749 (Korea, Republic of); Vesperini, E. [Department of Astronomy, Indiana University, Bloomington, IN 47405 (United States)

    2015-01-20

    We present semi-analytical models and simplified N-body simulations with 10{sup 4} particles aimed at probing the role of dynamical friction (DF) in determining the radial distribution of blue straggler stars (BSSs) in globular clusters. The semi-analytical models show that DF (which is the only evolutionary mechanism at work) is responsible for the formation of a bimodal distribution with a dip progressively moving toward the external regions of the cluster. However, these models fail to reproduce the formation of the long-lived central peak observed in all dynamically evolved clusters. The results of N-body simulations confirm the formation of a sharp central peak, which remains as a stable feature over time regardless of the initial concentration of the system. In spite of noisy behavior, a bimodal distribution forms in many cases, with the size of the dip increasing as a function of time. In the most advanced stages, the distribution becomes monotonic. These results are in agreement with the observations. Also, the shape of the peak and the location of the minimum (which, in most of cases, is within 10 core radii) turn out to be consistent with observational results. For a more detailed and close comparison with observations, including a proper calibration of the timescales of the dynamical processes driving the evolution of the BSS spatial distribution, more realistic simulations will be necessary.

  5. Analytical solution of transient temperature in continuous wave end-pumped laser slab: Reduction of temperature distribution and time of thermal response

    Directory of Open Access Journals (Sweden)

    Shibib Khalid S.

    2017-01-01

    Full Text Available An analytical solution of transient 3-D heat equation based on integral transform method is derived. The result are compared with numerical solution, and good agreements are obtained. Minimization of response time and temperature distribution through a laser slab are tested. It is found that the increasing in the lateral convection heat transfer coefficient can significantly reduce the response time and the temperature distribution while no effect on response time is observed when changing pumping profile from Gaussian to top hat beam in spite of the latter reduce the temperature distribution, also it is found that dividing the pumping power between two slab ends might reduce the temperature distribution and it has no effect on thermal response time.

  6. Research on the novel FBG detection system for temperature and strain field distribution

    Science.gov (United States)

    Liu, Zhi-chao; Yang, Jin-hua

    2017-10-01

    In order to collect the information of temperature and strain field distribution information, the novel FBG detection system was designed. The system applied linear chirped FBG structure for large bandwidth. The structure of novel FBG cover was designed as a linear change in thickness, in order to have a different response at different locations. It can obtain the temperature and strain field distribution information by reflection spectrum simultaneously. The structure of novel FBG cover was designed, and its theoretical function is calculated. Its solution is derived for strain field distribution. By simulation analysis the change trend of temperature and strain field distribution were analyzed in the conditions of different strain strength and action position, the strain field distribution can be resolved. The FOB100 series equipment was used to test the temperature in experiment, and The JSM-A10 series equipment was used to test the strain field distribution in experiment. The average error of experimental results was better than 1.1% for temperature, and the average error of experimental results was better than 1.3% for strain. There were individual errors when the strain was small in test data. It is feasibility by theoretical analysis, simulation calculation and experiment, and it is very suitable for application practice.

  7. Prediction method for thermal ratcheting of a cylinder subjected to axially moving temperature distribution

    International Nuclear Information System (INIS)

    Wada, Hiroshi; Igari, Toshihide; Kitade, Shoji.

    1989-01-01

    A prediction method was proposed for plastic ratcheting of a cylinder, which was subjected to axially moving temperature distribution without primary stress. First, a mechanism of this ratcheting was proposed, which considered the movement of temperature distribution as a driving force of this phenomenon. Predictive equations of the ratcheting strain for two representative temperature distributions were proposed based on this mechanism by assuming the elastic-perfectly-plastic material behavior. Secondly, an elastic-plastic analysis was made on a cylinder subjected to the representative two temperature distributions. Analytical results coincided well with the predicted results, and the applicability of the proposed equations was confirmed. (author)

  8. RADIAL DISTRIBUTION OF STARS, GAS, AND DUST IN SINGS GALAXIES. III. MODELING THE EVOLUTION OF THE STELLAR COMPONENT IN GALAXY DISKS

    International Nuclear Information System (INIS)

    Munoz-Mateos, J. C.; Boissier, S.; Gil de Paz, A.; Zamorano, J.; Gallego, J.; Kennicutt, R. C. Jr; Moustakas, J.; Prantzos, N.

    2011-01-01

    We analyze the evolution of 42 spiral galaxies in the Spitzer Infrared Nearby Galaxies Survey. We make use of ultraviolet (UV), optical, and near-infrared radial profiles, corrected for internal extinction using the total-infrared to UV ratio, to probe the emission of stellar populations of different ages as a function of galactocentric distance. We fit these radial profiles with models that describe the chemical and spectro-photometric evolution of spiral disks within a self-consistent framework. These backward evolutionary models successfully reproduce the multi-wavelength profiles of our galaxies, except for the UV profiles of some early-type disks for which the models seem to retain too much gas. From the model fitting we infer the maximum circular velocity of the rotation curve V C and the dimensionless spin parameter λ. The values of V C are in good agreement with the velocities measured in H I rotation curves. Even though our sample is not volume limited, the resulting distribution of λ is close to the lognormal function obtained in cosmological N-body simulations, peaking at λ ∼ 0.03 regardless of the total halo mass. We do not find any evident trend between λ and Hubble type, besides an increase in the scatter for the latest types. According to the model, galaxies evolve along a roughly constant mass-size relation, increasing their scale lengths as they become more massive. The radial scale length of most disks in our sample seems to have increased at a rate of 0.05-0.06 kpc Gyr -1 , although the same cannot be said of a volume-limited sample. In relative terms, the scale length has grown by 20%-25% since z = 1 and, unlike the former figure, we argue that this relative growth rate can be indeed representative of a complete galaxy sample.

  9. Radial Distribution of Stars, Gas, and Dust in SINGS Galaxies. III. Modeling the Evolution of the Stellar Component in Galaxy Disks

    Science.gov (United States)

    Muñoz-Mateos, J. C.; Boissier, S.; Gil de Paz, A.; Zamorano, J.; Kennicutt, R. C., Jr.; Moustakas, J.; Prantzos, N.; Gallego, J.

    2011-04-01

    We analyze the evolution of 42 spiral galaxies in the Spitzer Infrared Nearby Galaxies Survey. We make use of ultraviolet (UV), optical, and near-infrared radial profiles, corrected for internal extinction using the total-infrared to UV ratio, to probe the emission of stellar populations of different ages as a function of galactocentric distance. We fit these radial profiles with models that describe the chemical and spectro-photometric evolution of spiral disks within a self-consistent framework. These backward evolutionary models successfully reproduce the multi-wavelength profiles of our galaxies, except for the UV profiles of some early-type disks for which the models seem to retain too much gas. From the model fitting we infer the maximum circular velocity of the rotation curve V C and the dimensionless spin parameter λ. The values of V C are in good agreement with the velocities measured in H I rotation curves. Even though our sample is not volume limited, the resulting distribution of λ is close to the lognormal function obtained in cosmological N-body simulations, peaking at λ ~ 0.03 regardless of the total halo mass. We do not find any evident trend between λ and Hubble type, besides an increase in the scatter for the latest types. According to the model, galaxies evolve along a roughly constant mass-size relation, increasing their scale lengths as they become more massive. The radial scale length of most disks in our sample seems to have increased at a rate of 0.05-0.06 kpc Gyr-1, although the same cannot be said of a volume-limited sample. In relative terms, the scale length has grown by 20%-25% since z = 1 and, unlike the former figure, we argue that this relative growth rate can be indeed representative of a complete galaxy sample.

  10. CHARACTERIZING THE GALACTIC WHITE DWARF BINARY POPULATION WITH SPARSELY SAMPLED RADIAL VELOCITY DATA

    International Nuclear Information System (INIS)

    Maoz, Dan; Badenes, Carles; Bickerton, Steven J.

    2012-01-01

    We present a method to characterize statistically the parameters of a detached binary sample—binary fraction, separation distribution, and mass-ratio distribution—using noisy radial velocity data with as few as two, randomly spaced, epochs per object. To do this, we analyze the distribution of ΔRV max , the maximum radial velocity difference between any two epochs for the same object. At low values, the core of this distribution is dominated by measurement errors, but for large enough samples there is a high-velocity tail that can effectively constrain the parameters of the binary population. We discuss our approach for the case of a population of detached white dwarf (WD) binaries with separations that are decaying via gravitational wave emission. We derive analytic expressions for the present-day distribution of separations, integrated over the star formation history of the Galaxy, for parameterized initial WD separation distributions at the end of the common-envelope phase. We use Monte Carlo techniques to produce grids of simulated ΔRV max distributions with specific binary population parameters, and the same sampling cadences and radial velocity errors as the observations, and we compare them to the real ΔRV max distribution to constrain the properties of the binary population. We illustrate the sensitivity of the method to both the model and observational parameters. In the particular case of binary WDs, every model population predicts a merger rate per star which can easily be compared to specific Type Ia supernova rates. In a companion paper, we apply the method to a sample of ∼4000 WDs from the Sloan Digital Sky Survey. The binary fractions and separation distribution parameters allowed by the data indicate a rate of WD-WD mergers per unit stellar mass in the Galactic disk, ∼1 × 10 –13 mergers yr –1 M –1 ☉ , remarkably similar to the rate per unit mass of Type Ia supernovae in Milky Way like galaxies.

  11. Estimations of distribution and zoning for air temperature using satellite data over Liaoning province, China

    International Nuclear Information System (INIS)

    Wang, X.; Horiguchi, I.; Takeda, T.; Yazawa, M.; Liu, X.; Yang, Y.; Wang, Q.

    1999-01-01

    The distribution and zoning of air temperature over Liaoning Province, China were examined using the calculated values of air temperature derived from satellite data (GMS data) as well as from altitude data. The results are summarized as follows. At 02:00 LST the correlation coefficients for the air temperatures calculated from altitude compared with the observed air temperatures were the same as those of the air temperatures derived from GMS data. At 14:00 LST, however, the correlation coefficients for air temperatures calculated from altitude were less than those of the air temperatures derived from GMS data. This fact verifies that the distribution of air temperature in the day-time is affected by other factors than altitude. The distribution of air temperature in a cell of approximately 5'(latitude) x 7.5'(longitude) over Liaoning Province, china was estimated by using the regression equations between surface temperature derived from GMS and the observed air temperature. The distribution of air temperature was classified into 5 types, and the types are obtained at 14:00 LST are seasonal ones but the types at 02:00 LST are not related to season. Also, the regional classification for the air temperature was examined using this distribution of air temperature. This regional classification for the air temperature was similar to the published zoning of the agricultural climate. It became clear that the characteristic distribution of air temperature in a cell unit can be obtained by satellite data. And it is possible to define the zoning of air temperature for a cell unit by the accumulated analyses of satellite data over an extended period

  12. Axial and radial velocities in the creeping flow in a pipe

    Directory of Open Access Journals (Sweden)

    Zuykov Andrey L'vovich

    2014-05-01

    Full Text Available The article is devoted to analytical study of transformation fields of axial and radial velocities in uneven steady creeping flow of a Newtonian fluid in the initial portion of the cylindrical channel. It is shown that the velocity field of the flow is two-dimensional and determined by the stream function. The article is a continuation of a series of papers, where normalized analytic functions of radial axial distributions in uneven steady creeping flow in a cylindrical tube with azimuthal vorticity and stream function were obtained. There is Poiseuille profile for the axial velocity in the uniform motion of a fluid at an infinite distance from the entrance of the pipe (at x = ∞, here taken equal to zero radial velocity. There is uniform distribution of the axial velocity in the cross section at the tube inlet at x = 0, at which the axial velocity is constant along the current radius. Due to the axial symmetry of the flow on the axis of the pipe (at r = 0, the radial velocities and the partial derivative of the axial velocity along the radius, corresponding to the condition of the soft function extremum, are equal to zero. The authors stated vanishing of the velocity of the fluid on the walls of the pipe (at r = R , where R - radius of the tube due to its viscous sticking and tightness of the walls. The condition of conservation of volume flow along the tube was also accepted. All the solutions are obtained in the form of the Fourier - Bessel. It is shown that the hydraulic losses at uniform creeping flow of a Newtonian fluid correspond to Poiseuille - Hagen formula.

  13. Mathematical modeling of large floating roof reservoir temperature arena

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2018-03-01

    Full Text Available The current study is a simplification of related components of large floating roof tank and modeling for three dimensional temperature field of large floating roof tank. The heat transfer involves its transfer between the hot fluid in the oil tank, between the hot fluid and the tank wall and between the tank wall and the external environment. The mathematical model of heat transfer and flow of oil in the tank simulates the temperature field of oil in tank. Oil temperature field of large floating roof tank is obtained by numerical simulation, map the curve of central temperature dynamics with time and analyze axial and radial temperature of storage tank. It determines the distribution of low temperature storage tank location based on the thickness of the reservoir temperature. Finally, it compared the calculated results and the field test data; eventually validated the calculated results based on the experimental results.

  14. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification.

    Science.gov (United States)

    Dixon, Derek R; Schweiger, Michael J; Riley, Brian J; Pokorny, Richard; Hrma, Pavel

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric glass melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of the molten glass. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Because direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed in which the textural features in a laboratory-made cold cap with a simulated high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The temperature distribution within the cold cap was established by correlating microstructures of cold-cap regions with heat-treated feed samples of nearly identical structures at known temperatures. This temperature profile was compared with a mathematically simulated profile generated by a cold-cap model that has been developed to assess the rate of glass production in a melter.

  15. Spatial distribution of unidirectional trends in temperature and temperature extremes in Pakistan

    Science.gov (United States)

    Khan, Najeebullah; Shahid, Shamsuddin; Ismail, Tarmizi bin; Wang, Xiao-Jun

    2018-06-01

    Pakistan is one of the most vulnerable countries of the world to temperature extremes due to its predominant arid climate and geographic location in the fast temperature rising zone. Spatial distribution of the trends in annual and seasonal temperatures and temperature extremes over Pakistan has been assessed in this study. The gauge-based gridded daily temperature data of Berkeley Earth Surface Temperature (BEST) having a spatial resolution of 1° × 1° was used for the assessment of trends over the period 1960-2013 using modified Mann-Kendall test (MMK), which can discriminate the multi-decadal oscillatory variations from secular trends. The results show an increase in the annual average of daily maximum and minimum temperatures in 92 and 99% area of Pakistan respectively at 95% level of confidence. The annual temperature is increasing faster in southern high-temperature region compared to other parts of the country. The minimum temperature is rising faster (0.17-0.37 °C/decade) compared to maximum temperature (0.17-0.29 °C/decade) and therefore declination of diurnal temperature range (DTR) (- 0.15 to - 0.08 °C/decade) in some regions. The annual numbers of both hot and cold days are increasing in whole Pakistan except in the northern sub-Himalayan region. Heat waves are on the rise, especially in the hot Sindh plains and the Southern coastal region, while the cold waves are becoming lesser in the northern cold region. Obtained results contradict with the findings of previous studies on temperature trends, which indicate the need for reassessment of climatic trends in Pakistan using the MMK test to understand the anthropogenic impacts of climate change.

  16. Temperature distribution due to the heat generation in nuclear reactor shielding

    International Nuclear Information System (INIS)

    Torres, L.M.R.

    1985-01-01

    A study is performed for calculating nuclear heating due to the interaction of neutrons and gamma-rays with matter. Modifications were implemented in the ANISN and DOT 3.5 codes, that solve the transport equation using the discrete ordinate method, in one two-dimensions respectively, to include nuclear heating calculations in these codes. In order to determine the temperature distribution, using the finite difference method, a numerical model was developed for solving the heat conduction equation in one-dimension, in plane, cylindrical and spherical geometries, and in two-dimensions, X-Y and R-Z geometries. Based on these models, computer programs were developed for calculating the temperature distribution. Tests and applications of the implemented modifications were performed in problems of nuclear heating and temperature distribution due to radiation energy deposition in fission and fusion reactor shields. (Author) [pt

  17. Using radial metallicity gradients in dwarf galaxies to study environmental processing

    NARCIS (Netherlands)

    Leaman, R.; Venn, K.; Brooks, A.; Battaglia, G.; Cole, A.; Ibata, R.; Irwin, M.; McConnachie, A.; Mendel, T.; Tolstoy, E.; Starkenburg, E.

    2014-01-01

    The observed morphology-density relation in the Local Group suggests that some amount of environmental processing has occurred, however the nature and efficiency of tidal and ram pressure stripping is not well constrained. A possible avenue to test these processes is to study the radial distribution

  18. The electron density and temperature distributions predicted by bow shock models of Herbig-Haro objects

    International Nuclear Information System (INIS)

    Noriega-Crespo, A.; Bohm, K.H.; Raga, A.C.

    1990-01-01

    The observable spatial electron density and temperature distributions for series of simple bow shock models, which are of special interest in the study of Herbig-Haro (H-H) objects are computed. The spatial electron density and temperature distributions are derived from forbidden line ratios. It should be possible to use these results to recognize whether an observed electron density or temperature distribution can be attributed to a bow shock, as is the case in some Herbig-Haro objects. As an example, the empirical and predicted distributions for H-H 1 are compared. The predicted electron temperature distributions give the correct temperature range and they show very good diagnostic possibilities if the forbidden O III (4959 + 5007)/4363 wavelength ratio is used. 44 refs

  19. Two-dimensional finite difference model to study temperature distribution in SST regions of human limbs immediately after physical exercise in cold climate

    Science.gov (United States)

    Kumari, Babita; Adlakha, Neeru

    2015-02-01

    Thermoregulation is a complex mechanism regulating heat production within the body (chemical thermoregulation) and heat exchange between the body and the environment (physical thermoregulation) in such a way that the heat exchange is balanced and deep body temperatures are relatively stable. The external heat transfer mechanisms are radiation, conduction, convection and evaporation. The physical activity causes thermal stress and poses challenges for this thermoregulation. In this paper, a model has been developed to study temperature distribution in SST regions of human limbs immediately after physical exercise under cold climate. It is assumed that the subject is doing exercise initially and comes to rest at time t = 0. The human limb is assumed to be of cylindrical shape. The peripheral region of limb is divided into three natural components namely epidermis, dermis and subdermal tissues (SST). Appropriate boundary conditions have been framed based on the physical conditions of the problem. Finite difference has been employed for time, radial and angular variables. The numerical results have been used to obtain temperature profiles in the SST region immediately after continuous exercise for a two-dimensional unsteady state case. The results have been used to analyze the thermal stress in relation to light, moderate and vigorous intensity exercise.

  20. Physical mechanism determining the radial electric field and its radial structure in a toroidal plasma

    International Nuclear Information System (INIS)

    Ida, Katsumi; Miura, Yukitoshi; Itoh, Sanae

    1994-10-01

    Radial structures of plasma rotation and radial electric field are experimentally studied in tokamak, heliotron/torsatron and stellarator devices. The perpendicular and parallel viscosities are measured. The parallel viscosity, which is dominant in determining the toroidal velocity in heliotron/torsatron and stellarator devices, is found to be neoclassical. On the other hand, the perpendicular viscosity, which is dominant in dictating the toroidal rotation in tokamaks, is anomalous. Even without external momentum input, both a plasma rotation and a radial electric field exist in tokamaks and heliotrons/torsatrons. The observed profiles of the radial electric field do not agree with the theoretical prediction based on neoclassical transport. This is mainly due to the existence of anomalous perpendicular viscosity. The shear of the radial electric field improves particle and heat transport both in bulk and edge plasma regimes of tokamaks. (author) 95 refs

  1. Intelligent Monitoring System with High Temperature Distributed Fiberoptic Sensor for Power Plant Combustion Processes

    Energy Technology Data Exchange (ETDEWEB)

    Kwang Y. Lee; Stuart S. Yin; Andre Boehman

    2006-09-26

    The objective of the proposed work is to develop an intelligent distributed fiber optical sensor system for real-time monitoring of high temperature in a boiler furnace in power plants. Of particular interest is the estimation of spatial and temporal distributions of high temperatures within a boiler furnace, which will be essential in assessing and controlling the mechanisms that form and remove pollutants at the source, such as NOx. The basic approach in developing the proposed sensor system is three fold: (1) development of high temperature distributed fiber optical sensor capable of measuring temperatures greater than 2000 C degree with spatial resolution of less than 1 cm; (2) development of distributed parameter system (DPS) models to map the three-dimensional (3D) temperature distribution for the furnace; and (3) development of an intelligent monitoring system for real-time monitoring of the 3D boiler temperature distribution. Under Task 1, we have set up a dedicated high power, ultrafast laser system for fabricating in-fiber gratings in harsh environment optical fibers, successfully fabricated gratings in single crystal sapphire fibers by the high power laser system, and developed highly sensitive long period gratings (lpg) by electric arc. Under Task 2, relevant mathematical modeling studies of NOx formation in practical combustors have been completed. Studies show that in boiler systems with no swirl, the distributed temperature sensor may provide information sufficient to predict trends of NOx at the boiler exit. Under Task 3, we have investigated a mathematical approach to extrapolation of the temperature distribution within a power plant boiler facility, using a combination of a modified neural network architecture and semigroup theory. Given a set of empirical data with no analytic expression, we first developed an analytic description and then extended that model along a single axis.

  2. Digital feed back control for radial beam position

    International Nuclear Information System (INIS)

    Mestha, L.K.

    1989-09-01

    In the development of wide spread large scale distributed digital control systems, there is a requirement to automate small processes like radial beam control which will not only improve the beam quality but will also add local intelligence. Hence use is made here of digital control principles for such applications. The work concerned with the radial beam control discussed in this report has been developed for ISIS at RAL. The structure of the report is hence inclined more towards the local hardware system. The general feed back loop techniques can also be implemented for other control purpose. For instance, the author has successfully tested similar techniques to minimise the RF cavity tuning error, where the improvement in performance could not be matched by the analogue loop. A description of the RF cavity tuning programme and the associated experimental results will be published as a local paper for ISIS division. (author)

  3. Radial viscous fingering of hot asthenosphere within the Icelandic plume beneath the North Atlantic Ocean

    Science.gov (United States)

    Schoonman, C. M.; White, N. J.; Pritchard, D.

    2017-06-01

    The Icelandic mantle plume has had a significant influence on the geologic and oceanographic evolution of the North Atlantic Ocean during Cenozoic times. Full-waveform tomographic imaging of this region shows that the planform of this plume has a complex irregular shape with significant shear wave velocity anomalies lying beneath the lithospheric plates at a depth of 100-200 km. The distribution of these anomalies suggests that about five horizontal fingers extend radially beneath the fringing continental margins. The best-imaged fingers lie beneath the British Isles and beneath western Norway where significant departures from crustal isostatic equilibrium have been measured. Here, we propose that these radial fingers are generated by a phenomenon known as the Saffman-Taylor instability. Experimental and theoretical analyses show that fingering occurs when a less viscous fluid is injected into a more viscous fluid. In radial, miscible fingering, the wavelength and number of fingers are controlled by the mobility ratio (i.e. the ratio of viscosities), by the Péclet number (i.e. the ratio of advective and diffusive transport rates), and by the thickness of the horizontal layer into which fluid is injected. We combine shear wave velocity estimates with residual depth measurements around the Atlantic margins to estimate the planform distribution of temperature and viscosity within a horizontal asthenospheric layer beneath the lithospheric plate. Our estimates suggest that the mobility ratio is at least 20-50, that the Péclet number is O (104), and that the asthenospheric channel is 100 ± 20 km thick. The existence and planform of fingering is consistent with experimental observations and with theoretical arguments. A useful rule of thumb is that the wavelength of fingering is 5 ± 1 times the thickness of the horizontal layer. Our proposal has been further tested by examining plumes of different vigor and planform (e.g. Hawaii, Cape Verde, Yellowstone). Our results

  4. Transport modelling including radial electric field and plasma rotation

    International Nuclear Information System (INIS)

    Fukuyama, A.; Fuji, Y.; Itoh, S.-I.

    1994-01-01

    Using a simple turbulent transport model with a constant diffusion coefficient and a fixed temperature profile, the density profile in a steady state and the transient behaviour during the co and counter neutral beam injection are studied. More consistent analysis has been initiated with a turbulent transport model based on the current diffusive high-n ballooning mode. The enhancement of the radial electric field due to ion orbit losses and the reduction of the transport due to the poloidal rotation shear are demonstrated. The preliminary calculation indicates a sensitive temperature dependence of the density profile. (author)

  5. Experimental study on ratcheting of a cylinder subjected to axially moving temperature distribution

    International Nuclear Information System (INIS)

    Igari, T.; Yamauchi, M.; Wada, H.

    1989-01-01

    Development of a design of cylinder subjected to axially moving temperature distribution is very important in the design of the reactor vessel of fast breeder reactor containing high-temperature sodium. So far, however, a mechanism and a prediction method for this ratcheting have not been clarified. This paper proposes the ratcheting mechanism as well as the predictive equations of the ratcheting strain for the representative two temperature distributions. The proposed ratcheting mechanism was based on the hoop-membrane stress-strain behavior of the cylinder, and the movement of the temperature distribution was regarded as a driving force of this ratcheting. This paper describes the results of the experimental study on the proposed ratcheting mechanism and the predictive equations

  6. Radial effects in heating and thermal stability of a sub-ignited tokamak

    International Nuclear Information System (INIS)

    Fuchs, V.; Shoucri, M.M.; Thibaudeau, G.; Harten, L.; Bers, A.

    1982-02-01

    The existence of thermally stable sub-ignited equilibria of a tokamak reactor, sustained in operation by a feedback-controlled supplementary heating source, is demonstrated. The establishment of stability depends on a number of radially non-uniform, nonlinear processes whose effect is analyzed. One-dimensional (radial) stability analyses of model transport equations, together with numerical results from a 1-D transport code, are used in studying the heating of DT-plasmas in the thermonuclear regime. Plasma core supplementary heating is found to be a thermally more stable process than bulk heating. In the presence of impurity line radiation, however, core-heated temperature profiles may collapse, contracting inward from the limiter, the result of an instability caused by the increasing nature of the radiative cooling rate, with decreasing temperature. Conditions are established for the realization of a sub-ignited high-Q, toroidal reactor plasma with appreciable output power

  7. Critical transport current in granular high temperature superconductors

    International Nuclear Information System (INIS)

    Bogolyubov, N.A.

    1999-01-01

    The temperature and size dependence of the critical current in a zero magnetic field of three bismuth-based ceramic samples with round cross section and one sample with rectangular triangle cross section have been studied by a contactless technique. It is shown that the critical current can be presented as a product of the temperature and size dependent factors. The temperature-dependent multiplier reflects the individual peculiarities of the Josephson net of each sample, while the size factor is a homogeneous function of the cross-section sizes. The index of this function is independent of the cross-section form, the temperature and individual properties of HTSC samples. The radial distribution of critical current density in round samples and dependence of the critical current density on the magnetic conduction in granular HTSC have been found from the analysis of experimental data

  8. A linear stability analysis of thermal convection in spherical shells with variable radial gravity based on the Tau-Chebyshev method

    International Nuclear Information System (INIS)

    Avila, Ruben; Cabello-González, Ares; Ramos, Eduardo

    2013-01-01

    Highlights: • The Tau-Chebyshev method solves the linear fluid flow equations in spherical shells. • The fluid motion is driven by a central force proportional to the radial position. • The full Navier–Stokes equations are solved by the spectral element method. • The linear results are verified with the solution of the Navier–Stokes equations. • The solution of the linear problems is used to initiate non-linear calculations. -- Abstract: The onset of thermal convection in a non-rotating spherical shell is investigated using linear theory. The Tau-Chebyshev spectral method is used to integrate the linearized equations. We investigate the onset of thermal convection by considering two cases of the radial gravitational field (i) a local acceleration, acting radially inward, that is proportional to the distance from the center r, and (ii) a radial gravitational central force that is proportional to r −n . The former case has been widely analyzed in the literature, because it constitutes a simplified model that is usually used, in astrophysics and geophysics, and is studied here to validate the numerical method. The latter case was analyzed since the case n = 5 has been experimentally realized (by means of the dielectrophoretic effect) under microgravity condition, in the experimental container called GeoFlow, inside the International Space Station. Our study is aimed to clarify the role of (i) a radially inward central force (either proportional to r or to r −n ), (ii) a base conductive temperature distribution provided by either a uniform heat source or an imposed temperature difference between outer and inner spheres, and (iii) the aspect ratio η (ratio of the radii of the inner and outer spheres), on the critical Rayleigh number. In all cases the surface of the spheres has been assumed to be rigid. The results obtained with the linear theory based on the Tau-Chebyshev spectral method are compared with those of the integration of the full non

  9. Experimental determination of neutron temperature distribution in reactor cell; Eksperimentalno odredjivanje raspodele neutronske temperature u celiji reaktorske resetke

    Energy Technology Data Exchange (ETDEWEB)

    Bosevski, T [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-12-15

    This paper describes theoretical preparation of the experiment for measuring neutron temperature distribution at the RB reactor by activation foils. Due to rather low neutron flux Cu and Lu foil were irradiated for 4 days. Special natural uranium fuel element was prepared to enable easy removal of foils after irradiation. Experimental device was placed in the reactor core at half height in order to measure directly the mean neutron density. Experimental data of neutron temperature distribution for square lattice pitch 16 cm are presented with mean values of neutron temperature in the moderator, in the fuel and on the fuel element surface.

  10. The Origin of Radially Aligned Magnetic Fields in Young Supernova Remnants

    Science.gov (United States)

    Inoue, Tsuyoshi; Shimoda, Jiro; Ohira, Yutaka; Yamazaki, Ryo

    2013-08-01

    It has been suggested by radio observations of polarized synchrotron emissions that downstream magnetic fields in some young supernova remnants (SNRs) are oriented radially. We study the magnetic field distribution of turbulent SNRs driven by the Richtmyer-Meshkov instability (RMI)—in other words, the effect of rippled shock—by using three-dimensional magnetohydrodynamics simulations. We find that the induced turbulence has radially biased anisotropic velocity dispersion that leads to a selective amplification of the radial component of the magnetic field. The RMI is induced by the interaction between the shock and upstream density fluctuations. Future high-resolution polarization observations can distinguish the following candidates responsible for the upstream density fluctuations: (1) inhomogeneity caused by the cascade of large-scale turbulence in the interstellar medium, the so-called big power-law in the sky; (2) structures generated by the Drury instability in the cosmic-ray modified shock; and (3) fluctuations induced by the nonlinear feedback of the cosmic-ray streaming instability.

  11. THE ORIGIN OF RADIALLY ALIGNED MAGNETIC FIELDS IN YOUNG SUPERNOVA REMNANTS

    International Nuclear Information System (INIS)

    Inoue, Tsuyoshi; Shimoda, Jiro; Ohira, Yutaka; Yamazaki, Ryo

    2013-01-01

    It has been suggested by radio observations of polarized synchrotron emissions that downstream magnetic fields in some young supernova remnants (SNRs) are oriented radially. We study the magnetic field distribution of turbulent SNRs driven by the Richtmyer-Meshkov instability (RMI)—in other words, the effect of rippled shock—by using three-dimensional magnetohydrodynamics simulations. We find that the induced turbulence has radially biased anisotropic velocity dispersion that leads to a selective amplification of the radial component of the magnetic field. The RMI is induced by the interaction between the shock and upstream density fluctuations. Future high-resolution polarization observations can distinguish the following candidates responsible for the upstream density fluctuations: (1) inhomogeneity caused by the cascade of large-scale turbulence in the interstellar medium, the so-called big power-law in the sky; (2) structures generated by the Drury instability in the cosmic-ray modified shock; and (3) fluctuations induced by the nonlinear feedback of the cosmic-ray streaming instability

  12. Analysis of temperature distribution in a heat conducting fiber with ...

    African Journals Online (AJOL)

    The temperature distribution in a heat conducting fiber is computed using the Galerkin Finite Element Method in the present study. The weak form of the governing differential equation is obtained and nodal temperatures for linear and quadratic interpolation functions for different mesh densities are calculated for Neumann ...

  13. Application of 'SPICE' to predict temperature distribution in heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Li, H M; Liu, Y; Damodaran, M [Nanyang Technological Univ., Singapore (SG). School of Mechanical and Production Engineering

    1991-11-01

    This article presents a new alternative approach to predict temperature distribution in heat pipes. In this method, temperature distribution in a heat pipe, modelled as an analogous electrical circuit, is predicted by applying SPICE, a general-purpose circuit simulation program. SPICE is used to simulate electrical circuit designs before the prototype is assembled. Useful predictions are obtained for heat pipes with and without adiabatic sections and for heat pipes with various evaporator and condenser lengths. Comparison of the predicted results with experiments demonstrates fairly good agreement. It is also shown how interdisciplinary developments could be used appropriately. (author).

  14. Temperature distribution of a simplified rotor due to a uniform heat source

    Science.gov (United States)

    Welzenbach, Sarah; Fischer, Tim; Meier, Felix; Werner, Ewald; kyzy, Sonun Ulan; Munz, Oliver

    2018-03-01

    In gas turbines, high combustion efficiency as well as operational safety are required. Thus, labyrinth seal systems with honeycomb liners are commonly used. In the case of rubbing events in the seal system, the components can be damaged due to cyclic thermal and mechanical loads. Temperature differences occurring at labyrinth seal fins during rubbing events can be determined by considering a single heat source acting periodically on the surface of a rotating cylinder. Existing literature analysing the temperature distribution on rotating cylindrical bodies due to a stationary heat source is reviewed. The temperature distribution on the circumference of a simplified labyrinth seal fin is calculated using an available and easy to implement analytical approach. A finite element model of the simplified labyrinth seal fin is created and the numerical results are compared to the analytical results. The temperature distributions calculated by the analytical and the numerical approaches coincide for low sliding velocities, while there are discrepancies of the calculated maximum temperatures for higher sliding velocities. The use of the analytical approach allows the conservative estimation of the maximum temperatures arising in labyrinth seal fins during rubbing events. At the same time, high calculation costs can be avoided.

  15. A Generalised Assessment of Working Fluids and Radial Turbines for Non-Recuperated Subcritical Organic Rankine Cycles

    Directory of Open Access Journals (Sweden)

    Martin T. White

    2018-03-01

    Full Text Available The aim of this paper is to conduct a generalised assessment of both optimal working fluids and radial turbine designs for small-scale organic Rankine cycle (ORC systems across a range of heat-source temperatures. The former has been achieved by coupling a thermodynamic model of subcritical, non-recperated cycles with the Peng–Robinson equation of state, and optimising the working-fluid and cycle parameters for heat-source temperatures ranging between 80 ° C and 360 ° C . The critical temperature of the working fluid is found to be an important parameter governing working-fluid selection. Moreover, a linear correlation between heat-source temperature and the optimal critical temperature that achieves maximum power output has been found for heat-source temperatures below 300 ° C ( T cr = 0.830 T hi + 41.27 . This correlation has been validated against cycle calculations completed for nine predefined working fluids using both the Peng–Robinson equation of state and using the REFPROP program. Ultimately, this simple correlation can be used to identify working-fluid candidates for a specific heat-source temperature. In the second half of this paper, the effect of the heat-source temperature on the optimal design of a radial-inflow turbine rotor for a 25 kW subcritical ORC system has been studied. As the heat-source temperature increases, the optimal blade-loading coefficient increases, whilst the optimal flow coefficient reduces. Furthermore, passage losses are dominant in turbines intended for low-temperature applications. However, at higher heat-source temperatures, clearance losses become more dominant owing to the reduced blade heights. This information can be used to identify the most direct route to efficiency improvements in these machines. Finally, it is observed that the transition from a conventional converging stator to a converging-diverging stator occurs at heat-source temperatures of approximately 165 ° C , whilst radially

  16. Temperature distribution analysis of tissue water vaporization during microwave ablation: experiments and simulations.

    Science.gov (United States)

    Ai, Haiming; Wu, Shuicai; Gao, Hongjian; Zhao, Lei; Yang, Chunlan; Zeng, Yi

    2012-01-01

    The temperature distribution in the region near a microwave antenna is a critical factor that affects the entire temperature field during microwave ablation of tissue. It is challenging to predict this distribution precisely, because the temperature in the near-antenna region varies greatly. The effects of water vaporisation and subsequent tissue carbonisation in an ex vivo porcine liver were therefore studied experimentally and in simulations. The enthalpy and high-temperature specific absorption rate (SAR) of liver tissues were calculated and incorporated into the simulation process. The accuracy of predictions for near-field temperatures in our simulations has reached the level where the average maximum error is less than 5°C. In addition, a modified thermal model that accounts for water vaporisation and the change in the SAR distribution pattern is proposed and validated with experiment. The results from this study may be useful in the clinical practice of microwave ablation and can be applied to predict the temperature field in surgical planning.

  17. Practical solution of plastic deformation problems in elastic-plastic range

    Science.gov (United States)

    Mendelson, A; Manson, S

    1957-01-01

    A practical method for solving plastic deformation problems in the elastic-plastic range is presented. The method is one of successive approximations and is illustrated by four examples which include a flat plate with temperature distribution across the width, a thin shell with axial temperature distribution, a solid cylinder with radial temperature distribution, and a rotating disk with radial temperature distribution.

  18. Radial retinotomy in the macula.

    Science.gov (United States)

    Bovino, J A; Marcus, D F

    1984-01-01

    Radial retinotomy is an operative procedure usually performed in the peripheral or equatorial retina. To facilitate retinal attachment, the authors used intraocular scissors to perform radial retinotomy in the macula of two patients during vitrectomy surgery. In the first patient, a retinal detachment complicated by periretinal proliferation and macula hole formation was successfully reoperated with the aid of three radial cuts in the retina at the edges of the macular hole. In the second patient, an intraoperative retinal tear in the macula during diabetic vitrectomy was also successfully repaired with the aid of radial retinotomy. In both patients, retinotomy in the macula was required because epiretinal membranes, which could not be easily delaminated, were hindering retinal reattachment.

  19. Optimal distribution of temperature points in μSR measurement of local field

    International Nuclear Information System (INIS)

    Pełka, R.; Zieliński, P.M.; Konieczny, P.; Wasiutyński, T.

    2013-01-01

    Three possible distributions of temperature points in the μSR measurement of local field (order parameter) are discussed. The least square method is applied to estimate the scale of the deviations of the fitted parameters from the true values. It indicates that the distribution corresponding to a uniform section of the order parameter values (uniform-in-signal) incurs the smallest errors. The distribution constructed on the basis of the zeros of the Chebyshev polynomials yields comparable uncertainties, while the uniform-in-temperature distribution turns out to be least effective incurring considerably larger errors. These findings can be useful while planning an order parameter measurement in the μSR experiment

  20. Radial head dislocation during proximal radial shaft osteotomy.

    Science.gov (United States)

    Hazel, Antony; Bindra, Randy R

    2014-03-01

    The following case report describes a 48-year-old female patient with a longstanding both-bone forearm malunion, who underwent osteotomies of both the radius and ulna to improve symptoms of pain and lack of rotation at the wrist. The osteotomies were templated preoperatively. During surgery, after performing the planned radial shaft osteotomy, the authors recognized that the radial head was subluxated. The osteotomy was then revised from an opening wedge to a closing wedge with improvement of alignment and rotation. The case report discusses the details of the operation, as well as ways in which to avoid similar shortcomings in the future. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  1. A Low-cost Environmental Control System for Precise Radial Velocity Spectrometers

    Science.gov (United States)

    Sliski, David H.; Blake, Cullen H.; Halverson, Samuel

    2017-12-01

    We present an environmental control system (ECS) designed to achieve milliKelvin (mK) level temperature stability for small-scale astronomical instruments. This ECS is inexpensive and is primarily built from commercially available components. The primary application for our ECS is the high-precision Doppler spectrometer MINERVA-Red, where the thermal variations of the optical components within the instrument represent a major source of systematic error. We demonstrate ±2 mK temperature stability within a 0.5 m3 thermal enclosure using resistive heaters in conjunction with a commercially available PID controller and off-the-shelf thermal sensors. The enclosure is maintained above ambient temperature, enabling rapid cooling through heat dissipation into the surrounding environment. We demonstrate peak-to-valley (PV) temperature stability of better than 5 mK within the MINERVA-Red vacuum chamber, which is located inside the thermal enclosure, despite large temperature swings in the ambient laboratory environment. During periods of stable laboratory conditions, the PV variations within the vacuum chamber are less than 3 mK. This temperature stability is comparable to the best stability demonstrated for Doppler spectrometers currently achieving m s-1 radial velocity precision. We discuss the challenges of using commercially available thermoelectrically cooled CCD cameras in a temperature-stabilized environment, and demonstrate that the effects of variable heat output from the CCD camera body can be mitigated using PID-controlled chilled water systems. The ECS presented here could potentially provide the stable operating environment required for future compact “astrophotonic” precise radial velocity (PRV) spectrometers to achieve high Doppler measurement precision with a modest budget.

  2. Do the radial head prosthesis components fit with the anatomical structures of the proximal radioulnar joint?

    Science.gov (United States)

    Wegmann, Kilian; Hain, Moritz K; Ries, Christian; Neiss, Wolfram F; Müller, Lars P; Burkhart, Klaus J

    2015-09-01

    The fitting accuracy of radial head components has been investigated in the capitulo-radial joint, and reduced contact after prosthetic replacement of the radial head has been observed. The kinematics of the proximal radioulnar joint (PRUJ) are affected by radial head arthroplasty as well, but have not yet been investigated in this regard. The elbow joints of 60 upper extremities of formalin-fixed body donors were disarticulated to obtain a good view of the PRUJ. Each specimen was mounted on the examining table and radial head position in the native PRUJ was assessed in neutral position, full pronation, and full supination. Measurements were repeated after implantation of mono- and bi-polar prostheses. Analysis of the distribution of the joint contacts in the compartments showed significant differences after radial head replacement. In comparison to the native joint, after bipolar and monopolar radial head replacement, the physiological shift of the proximal radius was altered. The physiological shift of the joint contact of the radial head from anterior to posterior during forearm rotation that was found in the native joint in our cadaver model was not observed after prosthetic replacement. With higher conformity and physiological kinematic of radial head prostheses, possibly lower shear forces and lower contact pressures would be generated. The tested radial head prostheses do not replicate the physiological kinematics of the radial head. Further development in the prosthesis design has to be made. The meticulous reconstruction of the annular ligament seems to be of importance to increase joint contact.

  3. A study on the temperature distribution in the hot leg pipe

    International Nuclear Information System (INIS)

    Choe, Yoon-Jae; Baik, Se-Jin; Jang, Ho-Cheol; Lee, Byung-Jin; Im, In-Young; Ro, Tae-Sun

    2003-01-01

    In the hot leg pipes of reactor coolant system of the Korean Standard Nuclear Power Plant (KSNP), a non-uniform distribution in temperature has been observed across the cross-section, which is attributed to the non-uniformity of power distribution in the reactor core usually having a peak in the center region, and to the colder coolant bypass flow through the reactor vessel outlet nozzle clearances. As a result, the arithmetic mean temperature of four Resistance Temperature Detectors (RTDs) installed in each hot leg - two in the upper region and two in the lower region around the pipe wall may not correctly represent the actual coolant bulk temperature. It is also believed that there is a skewness in the velocity profile in the hot leg pipe due to the sudden changes in the flow direction and area from the core to the hot leg pipe, through the reactor vessel outlet plenum. These temperature non-uniformity and velocity skewness affect the measurement of the plant parameter such as the reactor coolant flow rate which is calculated by using the bulk temperature of hot leg pipes. A computational analysis has been performed to simulate the temperature and velocity distributions and to evaluate the uncertainty of temperature correction offset in the hot leg pipe. A commercial CFD code, FLUENT, is used for this analysis. The analysis results are compared with the operational data of KSNP and the scaled-down model test data for System 80. From the comparisons, an uncertainty of correction offset is obtained to measure the bulk temperature of hot leg more accurately, which can be also applied to the operating plants, leading to the reduction of temperature measurement uncertainty. Since the uncertainty of temperature in the hot leg pipe is one of major parameters to calculate the uncertainty of the reactor coolant flow rate, the analysis results can contribute to the improvement of the plant performance and safety by reducing the uncertainty of temperature measurement

  4. THE POSTERIOR DISTRIBUTION OF sin(i) VALUES FOR EXOPLANETS WITH MT sin(i) DETERMINED FROM RADIAL VELOCITY DATA

    International Nuclear Information System (INIS)

    Ho, Shirley; Turner, Edwin L.

    2011-01-01

    Radial velocity (RV) observations of an exoplanet system giving a value of M T sin(i) condition (i.e., give information about) not only the planet's true mass M T but also the value of sin(i) for that system (where i is the orbital inclination angle). Thus, the value of sin(i) for a system with any particular observed value of M T sin(i) cannot be assumed to be drawn randomly from a distribution corresponding to an isotropic i distribution, i.e., the presumptive prior distribution. Rather, the posterior distribution from which it is drawn depends on the intrinsic distribution of M T for the exoplanet population being studied. We give a simple Bayesian derivation of this relationship and apply it to several 'toy models' for the intrinsic distribution of M T , on which we have significant information from available RV data in some mass ranges but little or none in others. The results show that the effect can be an important one. For example, even for simple power-law distributions of M T , the median value of sin(i) in an observed RV sample can vary between 0.860 and 0.023 (as compared to the 0.866 value for an isotropic i distribution) for indices of the power law in the range between -2 and +1, respectively. Over the same range of indices, the 95% confidence interval on M T varies from 1.0001-2.405 (α = -2) to 1.13-94.34 (α = +2) times larger than M T sin(i) due to sin(i) uncertainty alone. More complex, but still simple and plausible, distributions of M T yield more complicated and somewhat unintuitive posterior sin(i) distributions. In particular, if the M T distribution contains any characteristic mass scale M c , the posterior sin(i) distribution will depend on the ratio of M T sin(i) to M c , often in a non-trivial way. Our qualitative conclusion is that RV studies of exoplanets, both individual objects and statistical samples, should regard the sin(i) factor as more than a 'numerical constant of order unity' with simple and well-understood statistical

  5. Radial cracks and fracture mechanism of radially oriented ring 2:17 type SmCo magnets

    International Nuclear Information System (INIS)

    Tian Jianjun; Pan Dean; Zhou Hao; Yin Fuzheng; Tao Siwu; Zhang Shengen; Qu Xuanhui

    2009-01-01

    Radially oriented ring 2:17 type SmCo magnets have different microstructure in the radial direction (easy magnetization) and axial direction (hard magnetization). The structure of the cross-section in radial direction is close-packed atomic plane, which shows cellular microstructure. The microstructure of the cross-section in axial direction consists of a mixture of rhombic microstructure and parallel lamella phases. So the magnets have obvious anisotropy of thermal expansion in different directions. The difference of the thermal expansion coefficients reaches the maximum value at 830-860 deg. C, which leads to radial cracks during quenching. The magnets have high brittlement because there are fewer slip systems in crystal structure. The fracture is brittle cleavage fracture.

  6. Sensitivity of Distributions of Climate System Properties to Surface Temperature Datasets

    Science.gov (United States)

    Libardoni, A. G.; Forest, C. E.

    2011-12-01

    Predictions of climate change from models depend strongly on the representation of climate system properties emerging from the processes and feedbacks in the models. The quality of any model prediction can be evaluated by determining how well its output reproduces the observed climate system. With this evaluation, the reliability of climate projections derived from the model and provided for policy makers is assessed and quantified. In this study, surface temperature, upper-air temperature, and ocean heat content data are used to constrain the distributions of the parameters that define three climate system properties in the MIT Integrated Global Systems Model: climate sensitivity, the rate of ocean heat uptake into the deep ocean, and net anthropogenic aerosol forcing. In particular, we explore the sensitivity of the distributions to the surface temperature dataset used to estimate the likelihood of model output given the observed climate records. In total, five different reconstructions of past surface temperatures are used and the resulting parameter distribution functions differ from each other. Differences in estimates of climate sensitivity mode and mean are as great as 1 K between the datasets, with an overall range of 1.2 to 5.3 K using the 5-95 confidence intervals. Ocean effective diffusivity is poorly constrained regardless of which dataset is used. All distributions show broad distributions and only three show signs of a distribution mode. When a mode is present, they tend to be for low diffusivity values. Distributions for the net aerosol forcing show similar shapes and cluster into two groups that are shifted by approximately 0.1 watts per square meter. However, the overall spread of forcing values from the 5-95 confidence interval, -0.19 to -0.83 watts per square meter, is small compared to other uncertainties in climate forcings. Transient climate response estimates derived from these distributions range between 0.87 and 2.41 K. Similar to the

  7. Sea Surface Temperature Modeling using Radial Basis Function Networks With a Dynamically Weighted Particle Filter

    KAUST Repository

    Ryu, Duchwan; Liang, Faming; Mallick, Bani K.

    2013-01-01

    be modeled by a dynamic system which changes with time and location. In this article, we propose a radial basis function network-based dynamic model which is able to catch the nonlinearity of the data and propose to use the dynamically weighted particle

  8. Investigation of radial dose effect on single event upset cross-section due to heavy ions using GEANT4

    International Nuclear Information System (INIS)

    Boorboor, S.; Feghhi, S.A.H.; Jafari, H.

    2015-01-01

    The heavy ions are the main cause to produce single event upset (SEU) damage on electronic devices since they are high LET radiations. The dimension of electronic components in new technology, arise a challenge in radiation effect estimations. Accurate investigations require fully considering the ion track in energy deposition as a radial dose distribution. In this work, the distribution of delta rays as well as LET have been calculated to determine ionization structure around ion track by a Monte Carlo code, GEANT4. The radial dose of several heavy ions with different energy in silicon was investigated and compared with the works by other authors in this field. The results showed that heavy ions with identical LET can have different SEU cross-section in silicon transistors. As a demonstrative example, according to our results, the error probability for 4.8 GeV iron was 8 times greater than that for 15 MeV carbon ions, in transistors with new process technology which have small dimension and low critical charges. Our results show that considering radial dose distribution considerably improves the accuracy of the SEU cross-section estimation in electronic devices especially for new technologies. - Highlights: • The single event upset is produced by heavy ions interaction on electronic devices. • The radial dose of several heavy ions in silicon was calculated by GEANT4. • Heavy ions with identical LET had different SEU cross-section in silicon transistors. • Low dimension and critical charge devices were more sensitive to radial dose effect

  9. Radial diffusive sampler for the determination of 8-h ambient ozone concentrations

    International Nuclear Information System (INIS)

    Plaisance, H.; Gerboles, M.; Piechocki, A.; Detimmerman, F.; Saeger, E. de

    2007-01-01

    The 8-h ozone radial diffusive sampler was evaluated according to the CEN protocol for the validation of diffusive samplers. All the parameters regarding the sampler characteristics were found to be consistent with the requirements of this protocol apart from the blank value, which must be evaluated and subtracted at each sampling. The nominal uptake rate was determined in laboratory conditions. However, the uptake rate depends on the mass uptake, temperature, humidity and on the combination of temperature and humidity. Based on laboratory experiments, an empirical model has been established which improved the agreement between the radial sampler and the reference method. This improvement was observed under several different meteorological and emission conditions of sampling. By using the model equation of uptake rate, the data quality objective of 30% for the expanded uncertainty included in the O 3 European Directive, is easily attained. Therefore, the sampler represents an appropriate indicative method. - A passive sampler has been fully validated for monitoring 8-h ozone concentrations in ambient air

  10. Energy Loss, Velocity Distribution, and Temperature Distribution for a Baffled Cylinder Model, Special Report

    Science.gov (United States)

    Brevoort, Maurice J.

    1937-01-01

    In the design of a cowling a certain pressure drop across the cylinders of a radial air-cooled engine is made available. Baffles are designed to make use of this available pressure drop for cooling. The problem of cooling an air-cooled engine cylinder has been treated, for the most part, from considerations of a large heat-transfer coefficient. The knowledge of the precise cylinder characteristics that give a maximum heat-transfer coefficient should be the first consideration. The next problem is to distribute this ability to cool so that the cylinder cools uniformly. This report takes up the problem of the design of a baffle for a model cylinder. A study has been made of the important principles involved in the operation of a baffle for an engine cylinder and shows that the cooling can be improved 20% by using a correctly designed baffle. Such a gain is as effective in cooling the cylinder with the improved baffle as a 65% increase in pressure drop across the standard baffle and fin tips.

  11. Radial force distribution changes associated with tangential force production in cylindrical grasping, and the importance of anatomical registration.

    Science.gov (United States)

    Pataky, Todd C; Slota, Gregory P; Latash, Mark L; Zatsiorsky, Vladimir M

    2012-01-10

    Radial force (F(r)) distributions describe grip force coordination about a cylindrical object. Recent studies have employed only explicit F(r) tasks, and have not normalized for anatomical variance when considering F(r) distributions. The goals of the present study were (i) to explore F(r) during tangential force production tasks, and (ii) to examine the extent to which anatomical registration (i.e. spatial normalization of anatomically analogous structures) could improve signal detectability in F(r) data. Twelve subjects grasped a vertically oriented cylindrical handle (diameter=6 cm) and matched target upward tangential forces of 10, 20, and 30 N. F(r) data were measured using a flexible pressure mat with an angular resolution of 4.8°, and were registered using piecewise-linear interpolation between five manually identified points-of-interest. Results indicate that F(r) was primarily limited to three contact regions: the distal thumb, the distal fingers, and the fingers' metatacarpal heads, and that, while increases in tangential force caused significant increases in F(r) for these regions, they did not significantly affect the F(r) distribution across the hand. Registration was found to substantially reduce between-subject variability, as indicated by both accentuated F(r) trends, and amplification of the test statistic. These results imply that, while subjects focus F(r) primarily on three anatomical regions during cylindrical grasp, inter-subject anatomical differences introduce a variability that, if not corrected for via registration, may compromise one's ability to draw anatomically relevant conclusions from grasping force data. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Modelling of temperature distribution and pulsations in fast reactor units

    International Nuclear Information System (INIS)

    Ushakov, P.A.; Sorokin, A.P.

    1994-01-01

    Reasons for the occurrence of thermal stresses in reactor units have been analyzed. The main reasons for this analysis are: temperature non-uniformity at the output of reactor core and breeder and the ensuing temperature pulsation; temperature pulsations due to mixing of sodium jets of a different temperature; temperature nonuniformity and pulsations resulting from the part of loops (circuits) un-plug; temperature nonuniformity and fluctuations in transient and accidental shut down of reactor or transfer to cooling by natural circulation. The results of investigating the thermal hydraulic characteristics are obtained by modelling the processes mentioned above. Analysis carried out allows the main lines of investigation to be defined and conclusions can be drawn regarding the problem of temperature distribution and fluctuation in fast reactor units

  13. Temperature Distribution and Influence Mechanism on Large Reflector Antennas under Solar Radiation

    Science.gov (United States)

    Wang, C. S.; Yuan, S.; Liu, X.; Xu, Q.; Wang, M.; Zhu, M. B.; Chen, G. D.; Duan, Y. H.

    2017-10-01

    The solar impact on antenna must be lessened for the large reflector antenna operating at high frequencies to have great electromagnetic performances. Therefore, researching the temperature distribution and its influence on large reflector antenna is necessary. The variation of solar incidence angle is first calculated. Then the model is simulated by the I-DEAS software, with the temperature, thermal stress, and thermal distortion distribution through the day obtained. In view of the important influence of shadow on antenna structure, a newly proposed method makes a comprehensive description of the temperature distribution on the reflector and its influence through the day by dividing a day into three different periods. The sound discussions and beneficial summary serve as the scientific foundation for the engineers to compensate the thermal distortion and optimize the antenna structure.

  14. Experiment of ambient temperature distribution in ICF driver's target building

    International Nuclear Information System (INIS)

    Zhou Yi; He Jie; Yang Shujuan; Zhang Junwei; Zhou Hai; Feng Bin; Xie Na; Lin Donghui

    2009-01-01

    An experiment is designed to explore the ambient temperature distribution in an ICF driver's target building, Multi-channel PC-2WS temperature monitoring recorders and PTWD-2A precision temperature sensors are used to measure temperatures on the three vertical cross-sections in the building, and the collected data have been handled by MATLAB. The experiment and analysis show that the design of the heating ventilation and air conditioning (HVAC) system can maintain the temperature stability throughout the building. However, because of the impact of heat in the target chamber, larger local environmental temperature gradients appear near the marshalling yard, the staff region on the middle floor, and equipments on the lower floor which needs to be controlled. (authors)

  15. Turbulent flow and temperature noise simulation by a multiparticle Monte Carlo method

    International Nuclear Information System (INIS)

    Hughes, G.; Overton, R.S.

    1980-10-01

    A statistical method of simulating real-time temperature fluctuations in liquid sodium pipe flow, for potential application to the estimation of temperature signals generated by subassembly blockages in LMFBRs is described. The method is based on the empirical characterisation of the flow by turbulence intensity and macroscale, radial velocity correlations and spectral form. These are used to produce realisations of the correlated motion of successive batches of representative 'marker particles' released at discrete time intervals into the flow. Temperature noise is generated by the radial mixing of the particles as they move downstream from an assumed mean temperature profile, where they acquire defined temperatures. By employing multi-particle batches, it is possible to perform radial heat transfer calculations, resulting in axial dissipation of the temperature noise levels. A simulated temperature-time signal is built up by recording the temperature at a given point in the flow as each batch of particles reaches the radial measurement plane. This is an advantage over conventional techniques which can usually only predict time-averaged parameters. (U.K.)

  16. Extreme Temperature Exceedances Change more Rapidly Under Future Warming in Regions of non-Gaussian Short Temperature Distribution Tails

    Science.gov (United States)

    Loikith, P. C.; Neelin, J. D.; Meyerson, J.

    2017-12-01

    Regions of shorter-than-Gaussian warm and cold side temperature distribution tails are shown to occur in spatially coherent patterns in the current climate. Under such conditions, warming may be manifested in more complex ways than if the underlying distribution were close to Gaussian. For example, under a uniform warm shift, the simplest prototype for future warming, a location with a short warm side tail would experience a greater increase in extreme warm exceedances compared to if the distribution were Gaussian. Similarly, for a location with a short cold side tail, a uniform warm shift would result in a rapid decrease in extreme cold exceedances. Both scenarios carry major societal and environmental implications including but not limited to negative impacts on human and ecosystem health, agriculture, and the economy. It is therefore important for climate models to be able to realistically reproduce short tails in simulations of historical climate in order to boost confidence in projections of future temperature extremes. Overall, climate models contributing to the fifth phase of the Coupled Model Intercomparison Project capture many of the principal observed regions of short tails. This suggests the underlying dynamics and physics occur on scales resolved by the models, and helps build confidence in model projections of extremes. Furthermore, most GCMs show more rapid changes in exceedances of extreme temperature thresholds in regions of short tails. Results therefore suggest that the shape of the tails of the underlying temperature distribution is an indicator of how rapidly a location will experience changes to extreme temperature occurrence under future warming.

  17. Conjugated heat transfer and temperature distributions in a gas turbine combustion liner under base-load operation

    International Nuclear Information System (INIS)

    Kim, Kyung Min; Yun, Nam Geon; Jeon, Yun Heung; Lee, Dong Hyun; Cho, Yung Hee

    2010-01-01

    Prediction of temperature distributions on hot components is important in development of a gas turbine combustion liner. The present study investigated conjugated heat transfer to obtain temperature distributions in a combustion liner with six combustion nozzles. 3D numerical simulations using FVM commercial codes, Fluent and CFX were performed to calculate combustion and heat transfer distributions. The temperature distributions in the combustor liner were calculated by conjugation of conduction and convection (heat transfer coefficients) obtained by combustion and cooling flow analysis. The wall temperature was the highest on the attachment points of the combustion gas from combustion nozzles, but the temperature gradient was high at the after shell section with low wall temperature

  18. Rainbow refractometry on particles with radial refractive index gradients

    Energy Technology Data Exchange (ETDEWEB)

    Saengkaew, Sawitree [CNRS/Universite et INSA de Rouen, UMR 6614/CORIA, BP12, 76 800, Saint Etienne du Rouvray CEDEX (France); Chulalongkorn University, Center of Excellence in Particle Technology, Faculty of Engineering, Bangkok (Thailand); Charinpanitkul, Tawatchai; Vanisri, Hathaichanok; Tanthapanichakoon, Wiwut [Chulalongkorn University, Center of Excellence in Particle Technology, Faculty of Engineering, Bangkok (Thailand); Biscos, Yves; Garcia, Nicolas; Lavergne, Gerard [ONERA/DMAE, Toulouse (France); Mees, Loic; Gouesbet, Gerard; Grehan, Gerard [CNRS/Universite et INSA de Rouen, UMR 6614/CORIA, BP12, 76 800, Saint Etienne du Rouvray CEDEX (France)

    2007-10-15

    The rainbow refractrometry, under its different configurations (classical and global), is an attractive technique to extract information from droplets in evaporation such as diameter and temperature. Recently a new processing strategy has been developed which increases dramatically the size and refractive index measurements accuracy for homogeneous droplets. Nevertheless, for mono component as well as for multicomponent droplets, the presence of temperature and/or of concentration gradients induce the presence of a gradient of refractive index which affects the interpretation of the recorded signals. In this publication, the effect of radial gradient on rainbow measurements with a high accuracy never reached previously is quantified. (orig.)

  19. Analysis of Hot Ions Detected during Equatorial Orbits of the Cassini Spacecraft at Saturn using the Convected Kappa Distribution Function and a Comparison to Voyager and Galileo Measurements at Jupiter

    Science.gov (United States)

    Kane, M.; Mitchell, D. G.; Carbary, J. F.; Hill, M. E.; Dialynas, K.; Mauk, B.; Krimigis, S. M.

    2017-12-01

    An extensive analysis of Cassini INCA and CHEMS measurements of 5-149 keV ions acquired during all equatorial orbits has been completed using a 3-D convected kappa distribution model. The computed plasma azimuthal speed, expressed as a fraction of the local corotation speed, decreases sharply with increasing distance from Saturn. The oxygen ion profile follows the hydrogen ion trend. For both species, the polar convection speed is the smallest of the 3 velocity components, and is centered about zero, but the radial speed has a significant radially outward component. Further, the radial component is enhanced in the pre-dawn sector. The hydrogen and oxygen temperatures increase with decreasing distance to Saturn. The calculated pattern of convection is consistent with an empirical model of plasma convection that includes outward radial transport and escape of plasma in a dawnside boundary layer of plasma entrained by the dawn magnetosheath flow. When the model convection pattern is scaled to the sub-solar magnetopause distance and to the sizes of Jupiter and Saturn, the pattern agrees with that derived from analysis of hot ions detected by the LECP detector on Voyager and the EPD instrument on Galileo. This and previous analysis of hot ion distributions has shown that the convected kappa distribution, with isotropy assumed in the plasma rest frame, has well described hot ion observed fluxes within a limited range of ion energies and has produced meaningful and ordered physical plasma parameters including plasma bulk velocity vectors, kappa distribution temperature profiles, and the general magnetospheric convection pattern at Jupiter and Saturn.

  20. Sensitivity of ion-induced sputtering to the radial distribution of energy transfers: A molecular dynamics study

    International Nuclear Information System (INIS)

    Mookerjee, S.; Khan, S. A.; Roy, A.; Beuve, M.; Toulemonde, M.

    2008-01-01

    Using different models for the deposition of energy on the lattice and a classical molecular dynamics approach to the subsequent transport, we evaluate how the details of the energy deposition model influence sputtering yield from a Lennard-Jones target irradiated with a MeV/u ion beam. Two energy deposition models are considered: a uniform, instantaneous deposition into a cylinder of fixed radius around the projectile ion track, used in earlier molecular dynamics and fluid dynamics simulations of sputtering yields; and an energy deposition distributed in time and space based on the formalism developed in the thermal spike model. The dependence of the sputtering yield on the total energy deposited on the target atoms is very sensitive to the energy deposition model. To clarify the origin of this strong dependence, we explore the role of the radial expansion of the electronic system prior to the transfer of its energy to the lattice. The results imply that observables such as the sputtering yield may be used as signatures of the fast electron-lattice energy transfer in the electronic energy-loss regime, and indicate the need for more experimental and theoretical investigations of these processes

  1. Extending the temperature range of the HTR

    International Nuclear Information System (INIS)

    Balcomb, J.D.; Wagner, P.

    1975-01-01

    The operating temperature of the high temperature helium-cooled reactor can be increased in a number of ways in order to provide higher temperature nuclear heat for various industrial processes. Modifications are of two types: 1) decrease in the temperature difference between the maximum coated particle fuel temperature and the mean exit gas temperature, and 2) increased maximum coated particle temperature. Gains in the latter category are limited by fission product diffusion into the gas steam and increases greater than 100 0 K are not forseen. Increases in the former category, however, are readily made and a variety of modifications are proposed as follows: incorporation of coated particles in the fuel matrix; use of a more finely-divided fuel coolant hole geometry to increase heat transfer coefficients and reduce conduction temperature differences; large increases in the fuel matrix graphite thermal conductivity (to about 50 W/m 0 K) to reduce conduction temperature differences; and modifications to the core distribution, both radially and axially. By such means the exit gas temperature can be increased to the range of 1200 0 K to 1600 0 K. (author)

  2. The analytical investigation of temperature distribution in off-central ...

    Indian Academy of Sciences (India)

    central diode-pumped; diode-pumped; temperature distribution. ... In our model we consider a laser crystal of radius b and length L. Heat is deposited ..... [13] M Abramawitz and I A Stegun (eds), Handbook of mathematical function (Dover,.

  3. Two dimensional radial gas flows in atmospheric pressure plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Kim, Gwihyun; Park, Seran; Shin, Hyunsu; Song, Seungho; Oh, Hoon-Jung; Ko, Dae Hong; Choi, Jung-Il; Baik, Seung Jae

    2017-12-01

    Atmospheric pressure (AP) operation of plasma-enhanced chemical vapor deposition (PECVD) is one of promising concepts for high quality and low cost processing. Atmospheric plasma discharge requires narrow gap configuration, which causes an inherent feature of AP PECVD. Two dimensional radial gas flows in AP PECVD induces radial variation of mass-transport and that of substrate temperature. The opposite trend of these variations would be the key consideration in the development of uniform deposition process. Another inherent feature of AP PECVD is confined plasma discharge, from which volume power density concept is derived as a key parameter for the control of deposition rate. We investigated deposition rate as a function of volume power density, gas flux, source gas partial pressure, hydrogen partial pressure, plasma source frequency, and substrate temperature; and derived a design guideline of deposition tool and process development in terms of deposition rate and uniformity.

  4. Core radial electric field and transport in Wendelstein 7-X plasmas

    Science.gov (United States)

    Pablant, N. A.; Langenberg, A.; Alonso, A.; Beidler, C. D.; Bitter, M.; Bozhenkov, S.; Burhenn, R.; Beurskens, M.; Delgado-Aparicio, L.; Dinklage, A.; Fuchert, G.; Gates, D.; Geiger, J.; Hill, K. W.; Höfel, U.; Hirsch, M.; Knauer, J.; Krämer-Flecken, A.; Landreman, M.; Lazerson, S.; Maaßberg, H.; Marchuk, O.; Massidda, S.; Neilson, G. H.; Pasch, E.; Satake, S.; Svennson, J.; Traverso, P.; Turkin, Y.; Valson, P.; Velasco, J. L.; Weir, G.; Windisch, T.; Wolf, R. C.; Yokoyama, M.; Zhang, D.; W7-X Team

    2018-02-01

    The results from the investigation of neoclassical core transport and the role of the radial electric field profile (Er) in the first operational phase of the Wendelstein 7-X (W7-X) stellarator are presented. In stellarator plasmas, the details of the Er profile are expected to have a strong effect on both the particle and heat fluxes. Investigation of the radial electric field is important in understanding neoclassical transport and in validation of neoclassical calculations. The radial electric field is closely related to the perpendicular plasma flow (u⊥) through the force balance equation. This allows the radial electric field to be inferred from measurements of the perpendicular flow velocity, which can be measured using the x-ray imaging crystal spectrometer and correlation reflectometry diagnostics. Large changes in the perpendicular rotation, on the order of Δu⊥˜ 5 km/s (ΔEr ˜ 12 kV/m), have been observed within a set of experiments where the heating power was stepped down from 2 MW to 0.6 MW. These experiments are examined in detail to explore the relationship between heating power temperature, and density profiles and the radial electric field. Finally, the inferred Er profiles are compared to initial neoclassical calculations based on measured plasma profiles. The results from several neoclassical codes, sfincs, fortec-3d, and dkes, are compared both with each other and the measurements. These comparisons show good agreement, giving confidence in the applicability of the neoclassical calculations to the W7-X configuration.

  5. Disentangling Time-series Spectra with Gaussian Processes: Applications to Radial Velocity Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Czekala, Ian [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Mandel, Kaisey S.; Andrews, Sean M.; Dittmann, Jason A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Ghosh, Sujit K. [Department of Statistics, NC State University, 2311 Stinson Drive, Raleigh, NC 27695 (United States); Montet, Benjamin T. [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States); Newton, Elisabeth R., E-mail: iczekala@stanford.edu [Massachusetts Institute of Technology, Cambridge, MA 02138 (United States)

    2017-05-01

    Measurements of radial velocity variations from the spectroscopic monitoring of stars and their companions are essential for a broad swath of astrophysics; these measurements provide access to the fundamental physical properties that dictate all phases of stellar evolution and facilitate the quantitative study of planetary systems. The conversion of those measurements into both constraints on the orbital architecture and individual component spectra can be a serious challenge, however, especially for extreme flux ratio systems and observations with relatively low sensitivity. Gaussian processes define sampling distributions of flexible, continuous functions that are well-motivated for modeling stellar spectra, enabling proficient searches for companion lines in time-series spectra. We introduce a new technique for spectral disentangling, where the posterior distributions of the orbital parameters and intrinsic, rest-frame stellar spectra are explored simultaneously without needing to invoke cross-correlation templates. To demonstrate its potential, this technique is deployed on red-optical time-series spectra of the mid-M-dwarf binary LP661-13. We report orbital parameters with improved precision compared to traditional radial velocity analysis and successfully reconstruct the primary and secondary spectra. We discuss potential applications for other stellar and exoplanet radial velocity techniques and extensions to time-variable spectra. The code used in this analysis is freely available as an open-source Python package.

  6. Perceived radial translation during centrifugation

    NARCIS (Netherlands)

    Bos, J.E.; Correia Grácio, B.J.

    2015-01-01

    BACKGROUND: Linear acceleration generally gives rise to translation perception. Centripetal acceleration during centrifugation, however, has never been reported giving rise to a radial, inward translation perception. OBJECTIVE: To study whether centrifugation can induce a radial translation

  7. A code for calculating force and temperature of a bitter plate type toroidal field coil system

    International Nuclear Information System (INIS)

    Christensen, U.

    1989-01-01

    To assist the design effort of the TF coils for CIT, a set of programs was developed to calculate the transient spatial distribution of the current density, the temperature and the forces in the TF coil conductor region. The TF coils are of the Bitter (disk) type design and therefore have negligible variation of current density in the toroidal direction. During the TF pulse, voltages are induced which cause the field and current to diffuse in the minor radial direction. This penetration, combined with the increase of resistance due to the temperature rise determines the distribution of the current. After the current distribution has been determined, the in-plane (TF-TF) and the out-of-plane (TF-PF) forces in the conductor are computed. The predicted currents and temperatures have been independently corroborated using the SPARK code which has been modified for this type of problem. 6 figs

  8. Geometry Analysis and Effect of Turbulence Model on the Radial Rotor Turbo-Expander Design for Small Organic Rankine Cycle System

    Directory of Open Access Journals (Sweden)

    Maulana Arifin

    2015-07-01

    Full Text Available Organic Rankine Cycle (ORC is one of the most promising technology for small electric power generations. The geometry analysis and the effect of turbulence model on the radial turbo-expanders design for small ORC power generation systems were discussed in this paper. The rotor blades and performance were calculated using several working fluids such as R134a, R143a, R245fa, n-Pentane, and R123. Subsequently, a numerical study was carried out in the fluid flow area with R134a and R123 as the working fluids. Analyses were performed using Computational Fluid Dynamics (CFD ANSYS Multiphysics on two real gas models, with the k-epsilon and SST (shear stress transport turbulence models. The result shows the distribution of Mach number, pressure, velocity and temperature along the rotor blade of the radial turbo-expanders and estimation of performance at various operating conditions. The operating conditions are as follow: 250,000 grid mesh flow area, real gas model SST at steady state condition, 0.4 kg/s of mass flow rate, 15,000 rpm rotor speed, 5 bar inlet pressure, and 373K inlet temperature. By using those conditions, CFD analysis shows that the turbo-expander able to produce 6.7 kW and 5.5 kW of power when using R134a and R123, respectively.

  9. 3D simulation of the catalyst density radial distribution in a riser of the FCC unit; Simulacao 3D da distribuicao radial de densidade do catalisador num riser de uma unidade de FCC

    Energy Technology Data Exchange (ETDEWEB)

    Apolonio, Adelia M.; Santos, Valdemir A. dos; Finkler, Christine L.L. [Universidade Catolica de Pernambuco (UNICAP), Recife, PE (Brazil); Dantas, Carlos C. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

    2008-07-01

    Local variations in the catalyst/vacuum gas oils mixing can lead to low conversions in some parts of a fluid cracking catalytic riser, while in other parts, high conversions will produce undesirable fuel gas and coke quantities. Knowledge of the apparent solid concentration in a cross-section of the riser is then essential. A computational program to generate tri dimensional graphics and level curves of the radial catalyst density in FCC risers was elaborated. The algorithm is based on determinations of the polynomial coefficients with aid of least square method and was tested with literature data, obtained by applications of nuclear technique of gamma radiation attenuation. The simulation results showed convergence with the experimental data. The precision of the mapping depends on the number of measurements and promote better conditions of diagnostic of the distribution catalyst type in the riser. (author)

  10. SULCUS TEMPERATURE DISTRIBUTIONS IN THE ABSENCE AND PRESENCE OF ORAL HYGIENE

    NARCIS (Netherlands)

    PERDOK, JF; LUKACOVIC, M; MAJETI, S; ARENDS, J; BUSSCHER, HJ

    In this study we investigated the possibility of using sulcus temperature measurements as an early indicator for the beginning of gingival inflammation. Sulcus temperature distributions over the arches appeared to obey a quadratic polynomial. With a test group of 10 volunteers, all dental students,

  11. A radial velocity survey of the Carina Nebula's O-type stars

    Science.gov (United States)

    Kiminki, Megan M.; Smith, Nathan

    2018-03-01

    We have obtained multi-epoch observations of 31 O-type stars in the Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m telescope. We measure their radial velocities to 1-2 km s-1 precision and present new or updated orbital solutions for the binary systems HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial velocities from the literature for 32 additional O-type and evolved massive stars in the region. The combined data set shows a mean heliocentric radial velocity of 0.6 km s-1. We calculate a velocity dispersion of ≤9.1 km s-1, consistent with an unbound, substructured OB association. The Tr 14 cluster shows a marginally significant 5 km s-1 radial velocity offset from its neighbor Tr 16, but there are otherwise no correlations between stellar position and velocity. The O-type stars in Cr 228 and the South Pillars region have a lower velocity dispersion than the region as a whole, supporting a model of distributed massive-star formation rather than migration from the central clusters. We compare our stellar velocities to the Carina Nebula's molecular gas and find that Tr 14 shows a close kinematic association with the Northern Cloud. In contrast, Tr 16 has accelerated the Southern Cloud by 10-15 km s-1, possibly triggering further massive-star formation. The expansion of the surrounding H II region is not symmetric about the O-type stars in radial velocity space, indicating that the ionized gas is constrained by denser material on the far side.

  12. A radial velocity survey of the Carina Nebula's O-type stars

    Science.gov (United States)

    Kiminki, Megan M.; Smith, Nathan

    2018-06-01

    We have obtained multi-epoch observations of 31 O-type stars in the Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m telescope. We measure their radial velocities to 1-2 km s-1 precision and present new or updated orbital solutions for the binary systems HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial velocities from the literature for 32 additional O-type and evolved massive stars in the region. The combined data set shows a mean heliocentric radial velocity of 0.6 km s-1. We calculate a velocity dispersion of ≤9.1 km s-1, consistent with an unbound, substructured OB association. The Tr 14 cluster shows a marginally significant 5 km s-1 radial velocity offset from its neighbour Tr 16, but there are otherwise no correlations between stellar position and velocity. The O-type stars in Cr 228 and the South Pillars region have a lower velocity dispersion than the region as a whole, supporting a model of distributed massive star formation rather than migration from the central clusters. We compare our stellar velocities to the Carina Nebula's molecular gas and find that Tr 14 shows a close kinematic association with the Northern Cloud. In contrast, Tr 16 has accelerated the Southern Cloud by 10-15 km s-1, possibly triggering further massive star formation. The expansion of the surrounding H II region is not symmetric about the O-type stars in radial velocity space, indicating that the ionized gas is constrained by denser material on the far side.

  13. Self-consistent radial sheath

    International Nuclear Information System (INIS)

    Hazeltine, R.D.

    1988-12-01

    The boundary layer arising in the radial vicinity of a tokamak limiter is examined, with special reference to the TEXT tokamak. It is shown that sheath structure depends upon the self-consistent effects of ion guiding-center orbit modification, as well as the radial variation of E /times/ B-induced toroidal rotation. Reasonable agreement with experiment is obtained from an idealized model which, however simplified, preserves such self-consistent effects. It is argued that the radial sheath, which occurs whenever confining magnetic field-lines lie in the plasma boundary surface, is an object of some intrinsic interest. It differs from the more familiar axial sheath because magnetized charges respond very differently to parallel and perpendicular electric fields. 11 refs., 1 fig

  14. Investigation of mechanisms for He-I emission radial profile broadening in a weakly ionized cylindrical helium plasma with recombining edge

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, E. M.; Brandt, C.; Hudson, B.; Nishijima, D.; Pigarov, A. Yu. [University of California–San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Kumar, D. [Johns Hopkins University, 3400 N Charles St., Baltimore, Maryland 21218 (United States)

    2013-09-15

    Spatially resolved spectroscopic measurements of He-I line emission are used to study the causes of emission profile broadening radially across the cylinder of a weakly ionized helium plasma. The plasma consists of an ionizing core (r < 2 cm) surrounded by a recombining edge (r > 2 cm) plasma. The brightness profiles of low-n EUV He-I resonance lines are shown to be strongly radially broadened due to opacity. The brightness profiles of high-n visible lines are also found to be strongly radially broadened, but dominantly due to edge recombination. Visible low-n lines are less strongly radially broadened, apparently by a combination of both recombination and EUV opacity. The low-n visible He-I line ratio method with central opacity correction is found to calculate central electron density and temperature well, with poor agreement at the edge, as expected for recombining plasma. In the recombining edge, high-n Boltzmann analysis is found to accurately measure the cold (T{sub e} < 0.2 eV) edge temperature. Near the core, however, high-n Boltzmann analysis can be complicated by electron-impact excitation, giving incorrect (T{sub e}≈ 0.1 eV) apparent temperatures. Probe measurements were not able to capture the cold edge temperature accurately, probably due to large potential fluctuations, even when using fast triple probe measurements. Fast spectroscopic measurements show that this discrepancy is not explained by recombining plasma alternating with ionizing plasma in the edge region.

  15. Tomography for two-dimensional gas temperature distribution based on TDLAS

    Science.gov (United States)

    Luo, Can; Wang, Yunchu; Xing, Fei

    2018-03-01

    Based on tunable diode laser absorption spectroscopy (TDLAS), the tomography is used to reconstruct the combustion gas temperature distribution. The effects of number of rays, number of grids, and spacing of rays on the temperature reconstruction results for parallel ray are researched. The reconstruction quality is proportional to the ray number. The quality tends to be smoother when the ray number exceeds a certain value. The best quality is achieved when η is between 0.5 and 1. A virtual ray method combined with the reconstruction algorithms is tested. It is found that virtual ray method is effective to improve the accuracy of reconstruction results, compared with the original method. The linear interpolation method and cubic spline interpolation method, are used to improve the calculation accuracy of virtual ray absorption value. According to the calculation results, cubic spline interpolation is better. Moreover, the temperature distribution of a TBCC combustion chamber is used to validate those conclusions.

  16. A simple reactivity feedback model accounting for radial core expansion effects in the liquid metal fast reactor

    International Nuclear Information System (INIS)

    Kwon, Young Min; Lee, Yong Bum; Chang, Won Pyo; Haha, Do Hee

    2002-01-01

    The radial core expansion due to the structure temperature rise is one of major negative reactivity insertion mechanisms in metallic fueled reactor. Thermal expansion is a result of both the laws of nature and the particular core design and it causes negative reactivity feedback by the combination of increased core volume captures and increased core surface leakage. The simple radial core expansion reactivity feedback model developed for the SSC-K code was evaluated by the code-to-code comparison analysis. From the comparison results, it can be stated that the radial core expansion reactivity feedback model employed into the SSC-K code may be reasonably accurate in the UTOP analysis

  17. A simple reactivity feedback model accounting for radial core expansion effects in the liquid metal fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Young Min; Lee, Yong Bum; Chang, Won Pyo; Haha, Do Hee [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    The radial core expansion due to the structure temperature rise is one of major negative reactivity insertion mechanisms in metallic fueled reactor. Thermal expansion is a result of both the laws of nature and the particular core design and it causes negative reactivity feedback by the combination of increased core volume captures and increased core surface leakage. The simple radial core expansion reactivity feedback model developed for the SSC-K code was evaluated by the code-to-code comparison analysis. From the comparison results, it can be stated that the radial core expansion reactivity feedback model employed into the SSC-K code may be reasonably accurate in the UTOP analysis.

  18. Thermophysical Property Estimation by Transient Experiments: The Effect of a Biased Initial Temperature Distribution

    Directory of Open Access Journals (Sweden)

    Federico Scarpa

    2015-01-01

    Full Text Available The identification of thermophysical properties of materials in dynamic experiments can be conveniently performed by the inverse solution of the associated heat conduction problem (IHCP. The inverse technique demands the knowledge of the initial temperature distribution within the material. As only a limited number of temperature sensors (or no sensor at all are arranged inside the test specimen, the knowledge of the initial temperature distribution is affected by some uncertainty. This uncertainty, together with other possible sources of bias in the experimental procedure, will propagate in the estimation process and the accuracy of the reconstructed thermophysical property values could deteriorate. In this work the effect on the estimated thermophysical properties due to errors in the initial temperature distribution is investigated along with a practical method to quantify this effect. Furthermore, a technique for compensating this kind of bias is proposed. The method consists in including the initial temperature distribution among the unknown functions to be estimated. In this way the effect of the initial bias is removed and the accuracy of the identified thermophysical property values is highly improved.

  19. Numerical Simulation of Magnetic Field Effect on Cryocooler Regenerators: Temperature Distribution

    Directory of Open Access Journals (Sweden)

    Rajendra Kumar

    2017-01-01

    Full Text Available Regenerative types of cryogenic refrigerators (or cryocoolers employ magnetic intermetallic compounds of 3d and 4f elements to work well below 10 K. This paper presents the analysis of temperature distribution in regenerators of such cryocoolers under the influence of magnetic fields of 1 T, 3 T, and 4.3 T. Commercial code of finite element analysis (FEA package, ANSYS (APDL 14.5, is used to investigate the temperature distribution under above-mentioned fields. Er3Ni is selected as regenerator material and the criteria for its selection are discussed in detail. The cold end temperature is varied from 4.2 K to 10 K and hot end temperature is fixed at 20 K. The values obtained from FEA clearly show that the ineffectiveness of Er3Ni is at 8 K and 10 K at 3 T and 4.3 T.

  20. Temperature dynamics of liquid outside a spherical bubble

    International Nuclear Information System (INIS)

    Sharipov, Vasily

    2011-01-01

    Radial Fourier equation describing temperature distribution outside a spherical bubble is considered. This equation appears from the energy conservation law written for a single bubble. Analytical approximation to the solution of this equation was built for radius and temperature of the surface of the bubble as arbitrary functions of time. In zero-order approximation it is assumed that variation amplitude of bubble radius is much smaller than its value. Together with first-order correction the so obtained solution is in good agreement with numerical results. Reported analytical approximation reduces computation efforts more than 10 times with comparison to the conventional numerical scheme. Finally presented semi-analytical approximation provides a possibility to describe acoustic effects and cavitations being incorporated into the multiphase flow code. (author)

  1. Transit and radial velocity survey efficiency comparison for a habitable zone Earth

    International Nuclear Information System (INIS)

    Burke, Christopher J.; McCullough, P. R.

    2014-01-01

    Transit and radial velocity searches are two techniques for identifying nearby extrasolar planets to Earth that transit bright stars. Identifying a robust sample of these exoplanets around bright stars for detailed atmospheric characterization is a major observational undertaking. In this study we describe a framework that answers the question of whether a transit or radial velocity survey is more efficient at finding transiting exoplanets given the same amount of observing time. Within the framework we show that a transit survey's window function can be approximated using the hypergeometric probability distribution. We estimate the observing time required for a transit survey to find a transiting Earth-sized exoplanet in the habitable zone (HZ) with an emphasis on late-type stars. We also estimate the radial velocity precision necessary to detect the equivalent HZ Earth-mass exoplanet that also transits when using an equal amount of observing time as the transit survey. We find that a radial velocity survey with σ rv ∼ 0.6 m s –1 precision has comparable efficiency in terms of observing time to a transit survey with the requisite photometric precision σ phot ∼ 300 ppm to find a transiting Earth-sized exoplanet in the HZ of late M dwarfs. For super-Earths, a σ rv ∼ 2.0 m s –1 precision radial velocity survey has comparable efficiency to a transit survey with σ phot ∼ 2300 ppm.

  2. Combined distributed Raman and Bragg fiber temperature sensing using incoherent optical frequency domain reflectometry

    Directory of Open Access Journals (Sweden)

    M. Koeppel

    2018-02-01

    Full Text Available Optical temperature sensors offer unique features which make them indispensable for key industries such as the energy sector. However, commercially available systems are usually designed to perform either distributed or distinct hot spot temperature measurements since they are restricted to one measurement principle. We have combined two concepts, fiber Bragg grating (FBG temperature sensors and Raman-based distributed temperature sensing (DTS, to overcome these limitations. Using a technique called incoherent optical frequency domain reflectometry (IOFDR, it is possible to cascade several FBGs with the same Bragg wavelength in one fiber and simultaneously perform truly distributed Raman temperature measurements. In our lab we have achieved a standard deviation of 2.5 K or better at a spatial resolution in the order of 1 m with the Raman DTS. We have also carried out a field test in a high-voltage environment with strong magnetic fields where we performed simultaneous Raman and FBG temperature measurements using a single sensor fiber only.

  3. Simultaneous measurement of dynamic strain and temperature distribution using high birefringence PANDA fiber Bragg grating

    Science.gov (United States)

    Zhu, Mengshi; Murayama, Hideaki

    2017-04-01

    New approach in simultaneous measurement of dynamic strain and temperature has been done by using a high birefringence PANDA fiber Bragg grating sensor. By this technique, we have succeeded in discriminating dynamic strain and temperature distribution at the sampling rate of 800 Hz and the spatial resolution of 1 mm. The dynamic distribution of strain and temperature were measured with the deviation of 5mm spatially. In addition, we have designed an experimental setup by which we can apply quantitative dynamic strain and temperature distribution to the fiber under testing without bounding it to a specimen.

  4. On the temperature dependence of the excess resistivity in dilute volatile alloys

    International Nuclear Information System (INIS)

    Uray, L.; Vicsek, T.

    1978-01-01

    In recrystallized wires of many important refractory alloys, an appreciable part of the temperature dependence of the measured excess resistivity is related to the radial distribution of the volatile solutes (extrinsic temperature dependence). Both the extrinsic and the intrinsic part of the temperature dependence of the excess resistivity have been determined for dilute WFe, WCo and WRe alloys, by measuring the resistance as a function of temperature and the thickness of layers removed by electrothinning. In this way the parameters of the evaporation profiles were also determined. In the surface region at low temperatures the length scale of the inhomogeneity is comparable to the mean-free path. Therefore, the observed extrinsic temperature dependence of the excess resistivity was calculated directly from the Boltzmann equation. The WCo alloy is a Kondo system, since its resistivity shows a minimum a 20 K. (author)

  5. Radial pseudoaneurysm following diagnostic coronary angiography

    Directory of Open Access Journals (Sweden)

    Shankar Laudari

    2015-06-01

    Full Text Available The radial artery access has gained popularity as a method of diagnostic coronary catheterization compared to femoral artery puncture in terms of vascular complications and early ambulation. However, very rare complication like radial artery pseudoaneurysm may occur following cardiac catheterization which may give rise to serious consequences. Here, we report a patient with radial pseudoaneurysm following diagnostic coronary angiography. Adequate and correct methodology of compression of radial artery following puncture for maintaining hemostasis is the key to prevention.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12776 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 48-50

  6. Modeling the wafer temperature profile in a multiwafer LPCVD furnace

    Energy Technology Data Exchange (ETDEWEB)

    Badgwell, T.A. [Rice Univ., Houston, TX (United States). Dept. of Chemical Engineering; Trachtenberg, I.; Edgar, T.F. [Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering

    1994-01-01

    A mathematical model has been developed to predict wafer temperatures within a hot-wall multiwafer low pressure chemical vapor deposition (LPCVD) reactor. The model predicts both axial (wafer-to-wafer) and radial (across-wafer) temperature profiles. Model predictions compare favorably with in situ wafer temperature measurements described in an earlier paper. Measured axial and radial temperature nonuniformities are explained in terms of radiative heat-transfer effects. A simulation study demonstrates how changes in the outer tube temperature profile and reactor geometry affect wafer temperatures. Reactor design changes which could improve the wafer temperature profile are discussed.

  7. Effect of body fat and gender on body temperature distribution.

    Science.gov (United States)

    Neves, Eduardo Borba; Salamunes, Ana Carla Chierighini; de Oliveira, Rafael Melo; Stadnik, Adriana Maria Wan

    2017-12-01

    It is well known that body composition can influence peripheral heat loss and skin temperature. That the distribution of body fat is affected by gender is well known; however, there is little information on how body composition and gender influences the measure of skin temperature. This study evaluated skin temperature distribution according to body fat percentage (BF%) and gender. A sample of 94 apparently healthy volunteers (47 women and 47 men) was assessed with Dual-Energy X-Ray Absorptiometry (DXA) and infrared thermography (mean, maximum and minimum temperatures - T Mean , T Max and T Min ). The sample was divided into groups, according to health risk classification, based on BF%, as proposed by the American College of Sports Medicine: Average (n = 58), Elevated (n = 16) or High (n = 20). Women had lower T Mean in most regions of interest (ROI). In both genders, group High had lower temperature values than Average and Elevated in the trunk, upper and lower limbs. In men, palms and posterior hands had a tendency (p temperature along with increased BF%. T Mean , T Max and T Min of trunk, upper and lower limbs were negatively correlated with BF% and the fat percentage of each segment (upper limbs, lower limbs and trunk). The highest correlations found in women were between posterior trunk and BF% (rho = -0.564, p temperature than men, which was related with higher BF%. Facial temperature seems not to be influenced by body fat. With the future collection of data on the relationship between BF% and skin temperature while taking into account factors such as body morphology, gender, and ethnicity, we conclude that measurement of BF may be reliably estimated with the use of thermal imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. An experimental simulation study of debris quenching in a radially stratified porous bed

    International Nuclear Information System (INIS)

    Sehgal, B.R.; Nayak, A.K.; Stepanyan, A.

    2004-01-01

    During a severe accident condition in a nuclear power plant, the core melt can fail the reactor vessel and relocate into the containment basement. In some accident management schemes, the vessel cavity is flooded with water. For these a particulate debris bed is likely to form on the cavity floor due to melt break-up in water. . In this situation, the coolability of debris bed on the containment floor is a crucial issue. This is because the debris bed still generates the decay heat and if it is uncoolable, it can eventually remelt and react with concrete basement generating a lot of noncondensable gases and pressurising the containment. Hence, it is important to cool the debris bed as an accident management programme. The main parameters affecting the coolability of the debris bed are its porosity which is a function of the size and shape of the particles which constitute the debris bed, the operating condition such as water flooding from the top or bottom of debris bed, water temperature and non-condensable gas generated during bed-concrete interactions. It is found from previous studies that the debris bed has a non-uniform particle distribution or a porosity stratification. This can happen both in radial and axial plane. For example, the bed can have a lower porosity at the centre and higher porosity at the periphery. It is of interest to investigate the quenching phenomena in such configurations so as to find an effective means of quenching the heat generating bed. While most of the previous investigations mainly concentrate on quenching of a homogenous or axially stratified particulate bed with volumetric heat generation, there are almost no studies on the above phenomena in a radially stratified porous bed. So the objective of this paper is to investigate the quenching phenomena in a radially stratified bed. To simulate the phenomena, we conducted experiments in an experimental facility named as POMECO (POrous MEdia COolability). The facility has a square

  9. Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

    International Nuclear Information System (INIS)

    Zou, Zhichao; Wang, Fujun; Yao, Zhifeng; Tao, Ran; Xiao, Ruofu; Li, Huaicheng

    2016-01-01

    Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t_0) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t_0, the radial force is small (approaching zero). At 0.4–1.4t_0, the radial force increases rapidly. After 1.4t_0, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research provides a scientific

  10. Impeller radial force evolution in a large double-suction centrifugal pump during startup at the shut-off condition

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Zhichao [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Wang, Fujun, E-mail: wangfj@cau.edu.cn [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Yao, Zhifeng [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Tao, Ran [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Xiao, Ruofu [College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083 (China); Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing 100083 (China); Li, Huaicheng [Shanghai Liancheng (Group) Co., Ltd., Shanghai 201812 (China)

    2016-12-15

    Highlights: • Conclude the characteristics of transient radial force in the startup process for a large double-suction centrifugal pump. • The overall direction of the radial force during startup process is also confirmed. • A formula used to calculate the transient radial force during startup process is proposed. • A relationship between radial force variation and axial vortex development in blade channel during the startup process is established. The mechanism of the radial force evolution is revealed. - Abstract: Double-suction centrifugal pumps play an important role in the main feedwater systems of nuclear power plant. The impeller radial force in a centrifugal pump varies dramatically during startup at the shut-off condition. In this study, the startup process of a large double-suction centrifugal pump is investigated using CFD. During testing, the impeller speed is accelerated from zero to its rated speed in 1.0 s (marked as t{sub 0}) and is then maintained at the rated speed. The results show that the radial force increase lags behind the impeller speed increase. At 0–0.4t{sub 0}, the radial force is small (approaching zero). At 0.4–1.4t{sub 0}, the radial force increases rapidly. After 1.4t{sub 0}, the average radial force stabilizes and reaches its maximum value of 55,619 N. The observed maximum radial force value during startup is approximately nine times as high as the radial force under rated condition. During startup, the overall radial force direction is proximate to the radial line located 25° from the volute tongue along circumferential direction. A transient radial force formula is proposed to evaluate the changes in radial force during startup. The streamline distribution in impeller passages and the impeller outlet pressure profile varying over time are produced. The relationship between radial force evolution and the varying axial-to-spiral vortex structure is analyzed. The radial force change mechanism is revealed. This research

  11. Global and radial variations in the efficiency of massive star formation among galaxies

    International Nuclear Information System (INIS)

    Allen, L.E.; Young, J.S.

    1990-01-01

    In order to determine the regions within galaxies which give rise to the most efficient star formation and to test the hypothesis that galaxies with high infrared luminosities per unit molecular mass are efficiently producing high mass stars, researchers have undertaken an H alpha imaging survey in galaxies whose CO distributions have been measured as part of the Five College Radio Astronomy Observatory (FCRAO) Extragalactic CO Survey. From these images researchers have derived global H alpha fluxes and distributions for comparison with far infrared radiation (FIR) fluxes and CO fluxes and distributions. Here, researchers present results on the global massive star formation efficiency (SFE = L sub H sub alpha/M(H2)) as a function of morphological type and environment, and on the radial distribution of the SFE within both peculiar and isolated galaxies. On the basis of comparison of the global L sub H sub alpha/M(H2) and L sub FIR/M(H2) for 111 galaxies, researchers conclude that environment rather than morphological type has the strongest effect on the global efficiency of massive star formation. Based on their study of a small sample, they find that the largest radial gradients are observed in the interacting/peculiar galaxies, indicating that environment affects the star formation efficiency within galaxies as well

  12. Reactivity effect of spent fuel due to spatial distributions for coolant temperature and burnup

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, T.; Yamane, Y. [Nagoya Univ., Dept. of Nuclear Engineering, Nagoya, Aichi (Japan); Suyama, K. [OECD/NEA, Paris (France); Mochizuki, H. [Japan Research Institute, Ltd., Tokyo (Japan)

    2002-03-01

    We investigated the reactivity effect of spent fuel caused by the spatial distributions of coolant temperature and burnup by using the integrated burnup calculation code system SWAT. The reactivity effect which arises from taking account of the spatial coolant temperature distribution increases as the average burnup increases, and reaches the maximum value of 0.69%{delta}k/k at 50 GWd/tU when the burnup distribution is concurrently considered. When the burnup distribution is ignored, the reactivity effect decreases by approximately one-third. (author)

  13. Endoscopic versus open radial artery harvest and mammario-radial versus aorto-radial grafting in patients undergoing coronary artery bypass surgery

    DEFF Research Database (Denmark)

    Carranza, Christian L; Ballegaard, Martin; Werner, Mads U

    2014-01-01

    the postoperative complications will be registered, and we will evaluate muscular function, scar appearance, vascular supply to the hand, and the graft patency including the patency of the central radial artery anastomosis. A patency evaluation by multi-slice computer tomography will be done at one year...... to aorto-radial revascularisation techniques but this objective is exploratory. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01848886.Danish Ethics committee number: H-3-2012-116.Danish Data Protection Agency: 2007-58-0015/jr.n:30-0838....

  14. Low temperature superconductor and aligned high temperature superconductor magnetic dipole system and method for producing high magnetic fields

    Science.gov (United States)

    Gupta, Ramesh; Scanlan, Ronald; Ghosh, Arup K.; Weggel, Robert J.; Palmer, Robert; Anerella, Michael D.; Schmalzle, Jesse

    2017-10-17

    A dipole-magnet system and method for producing high-magnetic-fields, including an open-region located in a radially-central-region to allow particle-beam transport and other uses, low-temperature-superconducting-coils comprised of low-temperature-superconducting-wire located in radially-outward-regions to generate high magnetic-fields, high-temperature-superconducting-coils comprised of high-temperature-superconducting-tape located in radially-inward-regions to generate even higher magnetic-fields and to reduce erroneous fields, support-structures to support the coils against large Lorentz-forces, a liquid-helium-system to cool the coils, and electrical-contacts to allow electric-current into and out of the coils. The high-temperature-superconducting-tape may be comprised of bismuth-strontium-calcium-copper-oxide or rare-earth-metal, barium-copper-oxide (ReBCO) where the rare-earth-metal may be yttrium, samarium, neodymium, or gadolinium. Advantageously, alignment of the large-dimension of the rectangular-cross-section or curved-cross-section of the high-temperature-superconducting-tape with the high-magnetic-field minimizes unwanted erroneous magnetic fields. Alignment may be accomplished by proper positioning, tilting the high-temperature-superconducting-coils, forming the high-temperature-superconducting-coils into a curved-cross-section, placing nonconducting wedge-shaped-material between windings, placing nonconducting curved-and-wedge-shaped-material between windings, or by a combination of these techniques.

  15. Preferred temperature and thermal breadth of birds wintering in peninsular Spain: the limited effect of temperature on species distribution

    Directory of Open Access Journals (Sweden)

    Luis M. Carrascal

    2016-07-01

    Full Text Available Background. The availability of environmental energy, as measured by temperature, is expected to limit the abundance and distribution of endotherms wintering at temperate latitudes. A prediction of this hypothesis is that birds should attain their highest abundances in warmer areas. However, there may be a spatial mismatch between species preferred habitats and species preferred temperatures, so some species might end-up wintering in sub-optimal thermal environments. Methods. We model the influence of minimum winter temperature on the relative abundance of 106 terrestrial bird species wintering in peninsular Spain, at 10 ×10 km2 resolution, using 95%-quantile regressions. We analyze general trends across species on the shape of the response curves, the environmental preferred temperature (at which the species abundance is maximized, the mean temperature in the area of distribution and the thermal breadth (area under the abundance-temperature curve. Results. Temperature explains a low proportion of variation in abundance. The most significant effect is on limiting the maximum potential abundance of species. Considering this upper-limit response, there is a large interspecific variability on the thermal preferences and specialization of species. Overall, there is a preponderance of positive relationships between species abundance and temperature; on average, species attain their maximum abundances in areas 1.9 °C warmer than the average temperature available in peninsular Spain. The mean temperature in the area of distribution is lower than the thermal preferences of the species. Discussion. Many species prefer the warmest areas to overwinter, which suggests that temperature imposes important restrictions to birds wintering in the Iberian Peninsula. However, one third of species overwinter in locations colder than their thermal preferences, probably reflecting the interaction between habitat and thermal requirements. There is a high inter

  16. Numerical simulation of liquid-metal-flows in radial-toroidal-radial bends

    International Nuclear Information System (INIS)

    Molokov, S.; Buehler, L.

    1993-09-01

    Magnetohydrodynamic flows in a U-bend and right-angle bend are considered with reference to the radial-toroidal-radial concept of a self-cooled liquid-metal blanket. The ducts composing bends have rectangular cross-section. The applied magnetic field is aligned with the toroidal duct and perpendicular to the radial ones. At high Hartmann number the flow region is divided into cores and boundary layers of different types. The magnetohydrodynamic equations are reduced to a system of partial differential equations governing wall electric potentials and the core pressure. The system is solved numerically by two different methods. The first method is iterative with iteration between wall potential and the core pressure. The second method is a general one for the solution of the core flow equations in curvilinear coordinates generated by channel geometry and magnetic field orientation. Results obtained are in good agreement. They show, that the 3D-pressure drop of MHD flows in a U-bend is not a critical issue for blanket applications. (orig./HP) [de

  17. Plasma potential and electron temperature evaluated by ball-pen and Langmuir probes in the COMPASS tokamak

    Science.gov (United States)

    Dimitrova, M.; Popov, Tsv K.; Adamek, J.; Kovačič, J.; Ivanova, P.; Hasan, E.; López-Bruna, D.; Seidl, J.; Vondráček, P.; Dejarnac, R.; Stöckel, J.; Imríšek, M.; Panek, R.; the COMPASS Team

    2017-12-01

    The radial distributions of the main plasma parameters in the scrape-off-layer of the COMPASS tokamak are measured during L-mode and H-mode regimes by using both Langmuir and ball-pen probes mounted on a horizontal reciprocating manipulator. The radial profile of the plasma potential derived previously from Langmuir probes data by using the first derivative probe technique is compared with data derived using ball-pen probes. A good agreement can be seen between the data acquired by the two techniques during the L-mode discharge and during the H-mode regime within the inter-ELM periods. In contrast with the first derivative probe technique, the ball-pen probe technique does not require a swept voltage and, therefore, the temporal resolution is only limited by the data acquisition system. In the electron temperature evaluation, in the far scrape-off layer and in the limiter shadow, where the electron energy distribution is Maxwellian, the results from both techniques match well. In the vicinity of the last closed flux surface, where the electron energy distribution function is bi-Maxwellian, the ball-pen probe technique results are in agreement with the high-temperature components of the electron distribution only. We also discuss the application of relatively large Langmuir probes placed in parallel and perpendicularly to the magnetic field lines to studying the main plasma parameters. The results obtained by the two types of the large probes agree well. They are compared with Thomson scattering data for electron temperatures and densities. The results for the electron densities are compared also with the results from ASTRA code calculation of the electron source due to the ionization of the neutrals by fast electrons and the origin of the bi-Maxwellian electron energy distribution function is briefly discussed.

  18. RADIAL VELOCITIES FROM VLT-KMOS SPECTRA OF GIANT STARS IN THE GLOBULAR CLUSTER NGC 6388

    International Nuclear Information System (INIS)

    Lapenna, E.; Mucciarelli, A.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E.; Origlia, L.; Valenti, E.; Cirasuolo, M.

    2015-01-01

    We present new radial velocity measurements for 82 stars, members of the Galactic globular cluster (GC) NGC 6388, obtained from ESO-VLT K-band Multi Object Spectrograph (KMOS) spectra acquired during the instrument Science Verification. The accuracy of the wavelength calibration is discussed and a number of tests of the KMOS response are presented. The cluster systemic velocity obtained (81.3 ± 1.5 km s –1 ) is in very good agreement with previous determinations. While a hint of ordered rotation is found between 9'' and 20'' from the cluster center, where the distribution of radial velocities is clearly bimodal, more data are needed before drawing any firm conclusions. The acquired sample of radial velocities has also been used to determine the cluster velocity dispersion (VD) profile between ∼9'' and 70'', supplementing previous measurements at r < 2'' and r > 60'' obtained with ESO-SINFONI and ESO-FLAMES spectroscopy, respectively. The new portion of the VD profile nicely matches the previous ones, better defining the knee of the distribution. The present work clearly shows the effectiveness of a deployable integral field unit in measuring the radial velocities of individual stars for determining the VD profile of Galactic GCs. It represents the pilot project for an ongoing large program with KMOS and FLAMES at the ESO-VLT, aimed at determining the next generation of VD and rotation profiles for a representative sample of GCs

  19. Mapping climate change in European temperature distributions

    International Nuclear Information System (INIS)

    Stainforth, David A; Chapman, Sandra C; Watkins, Nicholas W

    2013-01-01

    Climate change poses challenges for decision makers across society, not just in preparing for the climate of the future but even when planning for the climate of the present day. When making climate sensitive decisions, policy makers and adaptation planners would benefit from information on local scales and for user-specific quantiles (e.g. the hottest/coldest 5% of days) and thresholds (e.g. days above 28 ° C), not just mean changes. Here, we translate observations of weather into observations of climate change, providing maps of the changing shape of climatic temperature distributions across Europe since 1950. The provision of such information from observations is valuable to support decisions designed to be robust in today’s climate, while also providing data against which climate forecasting methods can be judged and interpreted. The general statement that the hottest summer days are warming faster than the coolest is made decision relevant by exposing how the regions of greatest warming are quantile and threshold dependent. In a band from Northern France to Denmark, where the response is greatest, the hottest days in the temperature distribution have seen changes of at least 2 ° C, over four times the global mean change over the same period. In winter the coldest nights are warming fastest, particularly in Scandinavia. (letter)

  20. Dedicated radial ventriculography pigtail catheter

    Energy Technology Data Exchange (ETDEWEB)

    Vidovich, Mladen I., E-mail: miv@uic.edu

    2013-05-15

    A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

  1. Temperature distribution determination of JPSR power reactor fuel element and cladding

    International Nuclear Information System (INIS)

    Sudarmono

    1996-01-01

    In order to utilize of fuel rod efficiency, a concept of JAERI passive Safety Reactor (JPSR) has been developed in Japan Atomic Energy Research Institute. In the JPSR design, UO 2 . are adopted as a fuel rod. The temperature distribution in the fuel rod and cladding in the hottest channel is a potential limiting design constraint of the JPSR. In the present determination, temperature distribution of the fuel rod and cladding for JPSR were PET:formed using COBRA-IV-I to evaluate the safety margin of the present JPSR design. In this method, the whole core was represented by the 1/4 sector and divided into 50 subchannels and 40 axial nodes. The temperature become maximum at the elevation of 1.922 and 2.196 m in the typical cell under operating condition. The maximum temperature in the center of the fuel rod surface of the fuel rod and cladding were 1620,4 o C, 722,8 o C, and 348,6 o C. The maximum results of temperature in the center of the fuel rod and cladding; were 2015,28 o C and 550 o C which were observed at 3.1 second in the typical cell

  2. Modelling the radial distribution of the inventory of U and Pu isotopes in PWR fuel rods at high burnup

    International Nuclear Information System (INIS)

    Furlano, L.; Marino, A.C.

    2015-01-01

    Nowadays trends on nuclear reactors are to take advantage of a more efficient use of the fuels. In this way, goals like decreasing the volume of radioactive wastes, increasing life time in the reactor, extended burnup and accident-tolerance fuels are taken as the principal guidelines for the design and construction for actual nuclear fuels. The development of tools and the capability of prediction of the behaviour of nuclear fuels under irradiation let us design and improve the new demanding conditions without neglecting the security and economics. In this way, the study of the evolution and details of the fissile material of the fuel in particular the 235 U inventory evolution and the 239 Pu production and evolution are demanding conditions. We implemented the PILR code, based on the RAPID model, for the radial distribution of U and Pu radioisotopes. The aim of this work is to determine production and disappearance of Pu and U isotopes during the irradiation of commercial and experimental fuel rods. (author)

  3. Determination of the radial profile of the photoelastic coefficient of polymer optical fibers

    Science.gov (United States)

    Acheroy, Sophie; Merken, Patrick; Geernaert, Thomas; Ottevaere, Heidi; Thienpont, Hugo; Berghmans, Francis

    2016-04-01

    We determine the radial profile of the photoelastic constant C(r) in two single mode and one multimode polymer optical fibers (POFs), all fabricated from polymethylmethacrylate (PMMA). To determine C(r) we first determine the retardance of the laterally illuminated fiber submitted to a known tensile stress uniformly distributed over the fiber cross-section. Then we determine the inverse Abel transform of the measured retardance to finally obtain C(r). We compare two algorithms based on the Fourier theory to perform the inverse transform. We obtain disparate distributions of C(r) in the three fibers. The mean value of C(r) varies from -7.6×10-14 to 5.4×10-12 Pa-1. This indicates that, in contrast to glass fibers, the radial profile of the photoelastic constant can considerable vary depending on the type and treatment of POFs, even when made from similar materials, and hence the photoelastic constant should be measured for each type of POF.

  4. Radial wave crystals: radially periodic structures from anisotropic metamaterials for engineering acoustic or electromagnetic waves.

    Science.gov (United States)

    Torrent, Daniel; Sánchez-Dehesa, José

    2009-08-07

    We demonstrate that metamaterials with anisotropic properties can be used to develop a new class of periodic structures that has been named radial wave crystals. They can be sonic or photonic, and wave propagation along the radial directions is obtained through Bloch states like in usual sonic or photonic crystals. The band structure of the proposed structures can be tailored in a large amount to get exciting novel wave phenomena. For example, it is shown that acoustical cavities based on radial sonic crystals can be employed as passive devices for beam forming or dynamically orientated antennas for sound localization.

  5. Quantification Model for Estimating Temperature Field Distributions of Apple Fruit

    OpenAIRE

    Zhang , Min; Yang , Le; Zhao , Huizhong; Zhang , Leijie; Zhong , Zhiyou; Liu , Yanling; Chen , Jianhua

    2009-01-01

    International audience; A quantification model of transient heat conduction was provided to simulate apple fruit temperature distribution in the cooling process. The model was based on the energy variation of apple fruit of different points. It took into account, heat exchange of representative elemental volume, metabolism heat and external heat. The following conclusions could be obtained: first, the quantification model can satisfactorily describe the tendency of apple fruit temperature dis...

  6. Model for radial gas fraction profiles in vertical pipe flow

    International Nuclear Information System (INIS)

    Lucas, D.; Krepper, E.; Prasser, H.M.

    2001-01-01

    A one-dimensional model is presented, which predicts the radial volume fraction profiles from a given bubble size distribution. It bases on the assumption of an equilibrium of the forces acting on a bubble perpendicularly to the flow path (non drag forces). For the prediction of the flow pattern this model could be used within an procedure together with appropriate models for local bubble coalescence and break-up. (orig.)

  7. Aneurisma idiopático de artéria radial: relato de caso Idiopathic radial artery aneurysm: case report

    Directory of Open Access Journals (Sweden)

    Luiz Ernani Meira Jr.

    2011-12-01

    Full Text Available Os aneurismas da artéria radial são extremamente raros. Em sua maioria, consistem de pseudoaneurismas pós-traumáticos. Os aneurismas da artéria radial verdadeiros podem ser idiopáticos, congênitos, pós-estenóticos ou associados a patologias, tais como vasculites e doenças do tecido conjuntivo. Foi relatado um caso de aneurisma idiopático de artéria radial em uma criança de três anos, que, após completa investigação diagnóstica complementar, foi submetida à ressecção cirúrgica.Radial artery aneurysms are extremely rare. Post-traumatic pseudoaneurysms are the vast majority. True radial artery aneurysms can be idiopathic, congenital, poststenotic, or associated with some pathologies, such as vasculitis and conjunctive tissue diseases. We report a case of an idiopathic aneurysm of the radial artery in a three-year-old child who was submitted to surgical resection after a complete diagnostic approach.

  8. Influence of absorbed pump profile on the temperature distribution ...

    Indian Academy of Sciences (India)

    Influence of absorbed pump profile on the temperature distribution within a diode side-pumped laser rod ... Department of Physics, Marvdasht Branch, Islamic Azad University, Marvdasht, Iran; Institute of Optics and Laser, Malek-ashtar University of Technology, Shahin Shahr, Postal Code: 83145/115, Iran; Department of ...

  9. Temperature field distribution of coal seam in heat injection

    OpenAIRE

    Zhang Zhizhen; Peng Weihong; Shang Xiaoji; Wang Kun; Li Heng; Ma Wenming

    2017-01-01

    In this article, we present a natural boundary element method (NBEM) to solve the steady heat flow problem with heat sources in a coal seam. The boundary integral equation is derived to obtain the temperature filed distribution of the coal seam under the different injecting conditions.

  10. Doubly stochastic radial basis function methods

    Science.gov (United States)

    Yang, Fenglian; Yan, Liang; Ling, Leevan

    2018-06-01

    We propose a doubly stochastic radial basis function (DSRBF) method for function recoveries. Instead of a constant, we treat the RBF shape parameters as stochastic variables whose distribution were determined by a stochastic leave-one-out cross validation (LOOCV) estimation. A careful operation count is provided in order to determine the ranges of all the parameters in our methods. The overhead cost for setting up the proposed DSRBF method is O (n2) for function recovery problems with n basis. Numerical experiments confirm that the proposed method not only outperforms constant shape parameter formulation (in terms of accuracy with comparable computational cost) but also the optimal LOOCV formulation (in terms of both accuracy and computational cost).

  11. Bismuth-catalyzed and doped silicon nanowires for one-pump-down fabrication of radial junction solar cells.

    Science.gov (United States)

    Yu, Linwei; Fortuna, Franck; O'Donnell, Benedict; Jeon, Taewoo; Foldyna, Martin; Picardi, Gennaro; Roca i Cabarrocas, Pere

    2012-08-08

    Silicon nanowires (SiNWs) are becoming a popular choice to develop a new generation of radial junction solar cells. We here explore a bismuth- (Bi-) catalyzed growth and doping of SiNWs, via vapor-liquid-solid (VLS) mode, to fabricate amorphous Si radial n-i-p junction solar cells in a one-pump-down and low-temperature process in a single chamber plasma deposition system. We provide the first evidence that catalyst doping in the SiNW cores, caused by incorporating Bi catalyst atoms as n-type dopant, can be utilized to fabricate radial junction solar cells, with a record open circuit voltage of V(oc) = 0.76 V and an enhanced light trapping effect that boosts the short circuit current to J(sc) = 11.23 mA/cm(2). More importantly, this bi-catalyzed SiNW growth and doping strategy exempts the use of extremely toxic phosphine gas, leading to significant procedure simplification and cost reduction for building radial junction thin film solar cells.

  12. Liquid level measurement on coolant pipeline using Raman distributed temperature sensor

    International Nuclear Information System (INIS)

    Kasinathan, M.; Sosamma, S.; Babu Rao, C.; Murali, N.; Jayakumar, T.

    2011-01-01

    Optical fibre based Raman Distributed Temperature Sensor (RDTS) has been widely used for temperature monitoring in oil pipe line, power cable and environmental monitoring. Recently it has gained importance in nuclear reactor owing to its advantages like continuous, distributed temperature monitoring and immunity from electromagnetic interference. It is important to monitor temperature based level measurement in sodium capacities and in coolant pipelines for Fast Breeder Reactor (FBR). This particular application is used for filling and draining sodium in storage tank of sodium circuits of Fast breeder reactor. There are different conventional methods to find out the sodium level in the storage tank of sodium cooled reactors. They are continuous level measurement and discontinuous level measurement. For continuous level measurement, mutual inductance type level probes are used. The disadvantage of using this method is it needs a temperature compensation circuit. For discontinuous level measurement, resistance type discontinuous level probe and mutual inductance type discontinuous level probe are used. In resistance type discontinuous level probe, each level needs a separate probe. To overcome these disadvantages, RDTS is used for level measurement based distributed temperature from optical fibre as sensor. The feasibility of using RDTS for measurement of temperature based level measurement sensor is studied using a specially designed test set-up and using hot water, instead of sodium. The test set-up consist of vertically erected Stainless Steel (SS) pipe of length 2m and diameter 10cm, with provision for filling and draining out the liquid. Bare graded index multimode fibre is laid straight along the length of the of the SS pipe. The SS pipe is filled with hot water at various levels. The hot water in the SS pipe is maintained at constant temperature by insulating the SS pipe. The temperature profile of the hot water at various levels is measured using RDTS. The

  13. Ulnar nerve entrapment complicating radial head excision

    Directory of Open Access Journals (Sweden)

    Kevin Parfait Bienvenu Bouhelo-Pam

    Full Text Available Introduction: Several mechanisms are involved in ischemia or mechanical compression of ulnar nerve at the elbow. Presentation of case: We hereby present the case of a road accident victim, who received a radial head excision for an isolated fracture of the radial head and complicated by onset of cubital tunnel syndrome. This outcome could be the consequence of an iatrogenic valgus of the elbow due to excision of the radial head. Hitherto the surgical treatment of choice it is gradually been abandoned due to development of radial head implant arthroplasty. However, this management option is still being performed in some rural centers with low resources. Discussion: The radial head plays an important role in the stability of the elbow and his iatrogenic deformity can be complicated by cubital tunnel syndrome. Conclusion: An ulnar nerve release was performed with favorable outcome. Keywords: Cubital tunnel syndrome, Peripheral nerve palsy, Radial head excision, Elbow valgus

  14. Effect of process parameters on temperature distribution in twin-electrode TIG coupling arc

    International Nuclear Information System (INIS)

    Zhang, Guangjun; Xiong, Jun; Gao, Hongming; Wu, Lin

    2012-01-01

    The twin-electrode TIG coupling arc is a new type of welding heat source, which is generated in a single welding torch that has two tungsten electrodes insulated from each other. This paper aims at determining the distribution of temperature for the coupling arc using the Fowler–Milne method under the assumption of local thermodynamic equilibrium. The influences of welding current, arc length, and distance between both electrode tips on temperature distribution of the coupling arc were analyzed. Based on the results, a better understanding of the twin-electrode TIG welding process was obtained. -- Highlights: ► Increasing arc current will increase the coupling arc temperature. ► Arc length seldom affects the peak temperature of the coupling arc. ► Increasing arc length will increase the extension of temperature near the anode. ► Increasing distance will decrease temperatures in the central part of the arc.

  15. Impact of vegetation growth on urban surface temperature distribution

    International Nuclear Information System (INIS)

    Buyadi, S N A; Mohd, W M N W; Misni, A

    2014-01-01

    Earlier studies have indicated that, the temperature distribution in the urban area is significantly warmer than its surrounding suburban areas. The process of urbanization has created urban heat island (UHI). As a city expands, trees are cut down to accommodate commercial development, industrial areas, roads, and suburban growth. Trees or green areas normally play a vital role in mitigating the UHI effects especially in regulating high temperature in saturated urban areas. This study attempts to assess the effects of vegetation growth on land surface temperature (LST) distribution in urban areas. An area within the City of Shah Alam, Selangor has been selected as the study area. Land use/land cover and LST maps of two different dates are generated from Landsat 5 TM images of the year 1991 and 2009. Only five major land cover classes are considered in this study. Mono-window algorithm is used to generate the LST maps. Landsat 5 TM images are also used to generate the NDVI maps. Results from this study have shown that there are significant land use changes within the study area. Although the conversion of green areas into residential and commercial areas significantly increase the LST, matured trees will help to mitigate the effects of UHI

  16. Radial transport in the Elmo Bumpy Torus in collisionless electron regimes

    International Nuclear Information System (INIS)

    Jaeger, E.F.; Hedrick, C.L.; Spong, D.A.

    1979-01-01

    One important area of disagreement between radial transport theory and the ELMO Bumpy Torus (EBT) experiment has been the degree of collisionality of the toroidal plasma electrons. Experiment shows relatively warm electrons (kTsub(e) approximately 300-600eV) and collisionless scaling, i.e. energy confinement increasing with temperature. But results of early one-dimensional (1-D), neoclassical transport models with radially inward pointing electric fields are limited to relatively cool electrons (kTsub(e) approximately 100-200eV) and collisional scaling. In this paper these early results are extended to include lowest-order effects of ion diffusion in regions where poloidal drift frequencies are small. The effects of direct, or non-diffusive, losses in such regions are neglected along with the effects of finite radial electric fields on electron transport coefficients and of self-consistent poloidal electric fields on ion transport coefficients. Results show that solutions in the collisionless electron regime do exist. Furthermore, when the effects of finite electron ring beta on magnetic fields near the plasma edge are included, these solutions occur at power levels consistent with experiment. (author)

  17. Optimization of PWR fuel assembly radial enrichment and burnable poison location based on adaptive simulated annealing

    International Nuclear Information System (INIS)

    Rogers, Timothy; Ragusa, Jean; Schultz, Stephen; St Clair, Robert

    2009-01-01

    The focus of this paper is to present a concurrent optimization scheme for the radial pin enrichment and burnable poison location in PWR fuel assemblies. The methodology is based on the Adaptive Simulated Annealing (ASA) technique, coupled with a neutron lattice physics code to update the cost function values. In this work, the variations in the pin U-235 enrichment are variables to be optimized radially, i.e., pin by pin. We consider the optimization of two categories of fuel assemblies, with and without Gadolinium burnable poison pins. When burnable poisons are present, both the radial distribution of enrichment and the poison locations are variables in the optimization process. Results for 15 x 15 PWR fuel assembly designs are provided.

  18. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  19. Temperature distribution in spouted bed and heat transfer

    International Nuclear Information System (INIS)

    Takeda, Hiroshi; Yamamoto, Yutaka

    1976-01-01

    Temperature distribution in spouted bed was measured by using brass and graphite spouted beds so as to investigate heat transfer characteristic of spouted bed applied to an apparatus of PyC coating. These spouted beds are batch type and are spouted by air or nitrogen gas of room temperature, and the outer wall of beds are heated by nichrome or graphite heater. Particles used for experiments are alumina spherical particles and the diameter is 0.80 -- 1.12 mm. Temperature condition is in the range of 400 -- 1,400 0 C. In the neighborhood of 400 0 C, the spouting condition is stable, while the spouting condition becomes unstable in the case of above 1,000 0 C. This is caused by abrupt temperature increase of spouting gas. It was found that heat transfer coefficient h sub(w) of our low temperature experiments was closer to the calculated from Malek et al.'s equation, h sub(p) of our experiments was several times greater than the calculated from Uemaki et al.'s equation. On the other hand, h sub(p) of high temperature experiments was compared with an experimental relation for convective heat transfer of fluidized bed, it was found that Nu sub(p) of our experiments was nearly equal to or greater than the calculated from the relation, this would be caused by radiant heat transfer. (auth.)

  20. Determining the temperature and density distribution from a Z-pinch radiation source

    International Nuclear Information System (INIS)

    Matuska, W.; Lee, H.

    1997-01-01

    High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper the authors propose a different approach by which they can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. The authors use a parameter optimization routine to find the temperature and density distributions that best fit the data. They know from their past experience that the radiation source resulting from the implosion of a thin foil does not exhibit good axial symmetry. However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments the method will provide a valuable diagnostic tool

  1. Fast analysis of molecular dynamics trajectories with graphics processing units-Radial distribution function histogramming

    International Nuclear Information System (INIS)

    Levine, Benjamin G.; Stone, John E.; Kohlmeyer, Axel

    2011-01-01

    The calculation of radial distribution functions (RDFs) from molecular dynamics trajectory data is a common and computationally expensive analysis task. The rate limiting step in the calculation of the RDF is building a histogram of the distance between atom pairs in each trajectory frame. Here we present an implementation of this histogramming scheme for multiple graphics processing units (GPUs). The algorithm features a tiling scheme to maximize the reuse of data at the fastest levels of the GPU's memory hierarchy and dynamic load balancing to allow high performance on heterogeneous configurations of GPUs. Several versions of the RDF algorithm are presented, utilizing the specific hardware features found on different generations of GPUs. We take advantage of larger shared memory and atomic memory operations available on state-of-the-art GPUs to accelerate the code significantly. The use of atomic memory operations allows the fast, limited-capacity on-chip memory to be used much more efficiently, resulting in a fivefold increase in performance compared to the version of the algorithm without atomic operations. The ultimate version of the algorithm running in parallel on four NVIDIA GeForce GTX 480 (Fermi) GPUs was found to be 92 times faster than a multithreaded implementation running on an Intel Xeon 5550 CPU. On this multi-GPU hardware, the RDF between two selections of 1,000,000 atoms each can be calculated in 26.9 s per frame. The multi-GPU RDF algorithms described here are implemented in VMD, a widely used and freely available software package for molecular dynamics visualization and analysis.

  2. Assessing the Adequacy of Probability Distributions for Estimating the Extreme Events of Air Temperature in Dabaa Region

    International Nuclear Information System (INIS)

    El-Shanshoury, Gh.I.

    2015-01-01

    Assessing the adequacy of probability distributions for estimating the extreme events of air temperature in Dabaa region is one of the pre-requisite s for any design purpose at Dabaa site which can be achieved by probability approach. In the present study, three extreme value distributions are considered and compared to estimate the extreme events of monthly and annual maximum and minimum temperature. These distributions include the Gumbel/Frechet distributions for estimating the extreme maximum values and Gumbel /Weibull distributions for estimating the extreme minimum values. Lieblein technique and Method of Moments are applied for estimating the distribution para meters. Subsequently, the required design values with a given return period of exceedance are obtained. Goodness-of-Fit tests involving Kolmogorov-Smirnov and Anderson-Darling are used for checking the adequacy of fitting the method/distribution for the estimation of maximum/minimum temperature. Mean Absolute Relative Deviation, Root Mean Square Error and Relative Mean Square Deviation are calculated, as the performance indicators, to judge which distribution and method of parameters estimation are the most appropriate one to estimate the extreme temperatures. The present study indicated that the Weibull distribution combined with Method of Moment estimators gives the highest fit, most reliable, accurate predictions for estimating the extreme monthly and annual minimum temperature. The Gumbel distribution combined with Method of Moment estimators showed the highest fit, accurate predictions for the estimation of the extreme monthly and annual maximum temperature except for July, August, October and November. The study shows that the combination of Frechet distribution with Method of Moment is the most accurate for estimating the extreme maximum temperature in July, August and November months while t he Gumbel distribution and Lieblein technique is the best for October

  3. Anomalies of radial and ulnar arteries

    Directory of Open Access Journals (Sweden)

    Rajani Singh

    Full Text Available Abstract During dissection conducted in an anatomy department of the right upper limb of the cadaver of a 70-year-old male, both origin and course of the radial and ulnar arteries were found to be anomalous. After descending 5.5 cm from the lower border of the teres major, the brachial artery anomalously bifurcated into a radial artery medially and an ulnar artery laterally. In the arm, the ulnar artery lay lateral to the median nerve. It followed a normal course in the forearm. The radial artery was medial to the median nerve in the arm and then, at the level of the medial epicondyle, it crossed from the medial to the lateral side of the forearm, superficial to the flexor muscles. The course of the radial artery was superficial and tortuous throughout the arm and forearm. The variations of radial and ulnar arteries described above were associated with anomalous formation and course of the median nerve in the arm. Knowledge of neurovascular anomalies are important for vascular surgeons and radiologists.

  4. Variations in the usage and composition of a radial cocktail during radial access coronary angiography procedures.

    LENUS (Irish Health Repository)

    Pate, G

    2011-10-01

    A survey was conducted of medication administered during radial artery cannulation for coronary angiography in 2009 in Ireland; responses were obtained for 15 of 20 centres, in 5 of which no radial access procedures were undertaken. All 10 (100%) centres which provided data used heparin and one or more anti-spasmodics; verapamil in 9 (90%), nitrate in 1 (10%), both in 2 (20%). There were significant variations in the doses used. Further work needs to be done to determine the optimum cocktail to prevent radial artery injury following coronary angiography.

  5. Shape Effect on the Temperature Field during Microwave Heating Process

    Directory of Open Access Journals (Sweden)

    Zhijun Zhang

    2018-01-01

    Full Text Available Aiming at improving the food quality during microwave process, this article mainly focused on the numerical simulation of shape effect, which was evaluated by microwave power absorption capability and temperature distribution uniformity in a single sample heated in a domestic microwave oven. This article only took the electromagnetic field and heat conduction in solid into consideration. The Maxwell equations were used to calculate the distribution of microwave electromagnetic field distribution in the microwave cavity and samples; then the electromagnetic energy was coupled as the heat source in the heat conduction process in samples. Quantitatively, the power absorption capability and temperature distribution uniformity were, respectively, described by power absorption efficiency (PAE and the statistical variation of coefficient (COV. In addition, we defined the comprehensive evaluation coefficient (CEC to describe the usability of a specific sample. In accordance with volume or the wave numbers and penetration numbers in the radial and axial directions of samples, they can be classified into different groups. And according to the PAE, COV, and CEC value and the specific need of microwave process, an optimal sample shape and orientation could be decided.

  6. Asymmetric power device rating selection for even temperature distribution in NPC inverter

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede

    2017-01-01

    the power rating and lifetime of the NPC inverter are limited by the most stressed devices. In this paper, an asymmetric power device rating selection method for the NPC inverter is proposed in order to balance the lifetimes of the power devices. The thermal distribution of the power devices is analyzed......A major drawback of the NPC inverter is an unequal power loss distribution among the power devices which leads to unequal temperature stress among them. Therefore, certain power devices experience higher temperature stress, which is the main cause of power device module failure and thus both...... based on 30 kW NPC inverter as a case study. Analytical power loss and thermal impedance models depending on the chip size are derived. Finally, using these models, the junction temperatures of the power devices depending on the chip size is discussed and a proper chip size for an even temperature...

  7. Atomic Structure and Energy Distribution of Collapsed Carbon Nanotubes of Different Chiralities

    Directory of Open Access Journals (Sweden)

    Julia A. Baimova

    2015-01-01

    Full Text Available For carbon nanotubes of sufficiently large diameter at sufficiently low temperature, due to the action of the van der Waals forces, the ground state is a bilayer graphene with closed edges, the so-called collapsed configuration. Molecular dynamics simulation of collapsed carbon nanotubes is performed. The effect of length, diameter, and chirality of the nanotubes on their properties is investigated. It is shown that collapsed nanotubes after relaxation have rippled structure which is strongly dependent on the nanotube chirality. The structural properties are studied by calculating the radial distribution function and energy distribution along various regions in the collapsed carbon nanotubes.

  8. Design of radial reinforcement for prestressed concrete containments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shen, E-mail: swang@bechtel.com [Bechtel Power Corporation, 5275 Westview Drive, BP2-2C3, Frederick, MD 21703 (United States); Munshi, Javeed A., E-mail: jamunshi@bechtel.com [Bechtel Power Corporation, 5275 Westview Drive, BP2-2C3, Frederick, MD 21703 (United States)

    2013-02-15

    Highlights: ► A rigorous formulae is proposed to calculate radial stress within prestressed concrete containments. ► The proposed method is validated by finite element analysis in an illustrative practical example. ► A partially prestressed condition is more critical than a fully prestressed condition for radial tension. ► Practical design consideration is provided for detailing of radial reinforcement. -- Abstract: Nuclear containments are critical components for safety of nuclear power plants. Failure can result in catastrophic safety consequences as a result of leakage of radiation. Prestressed concrete containments have been used in large nuclear power plants with significant design internal pressure. These containments are generally reinforced with prestressing tendons in the circumferential (hoop) and meridional (vertical) directions. The curvature effect of the tendons introduces radial tensile stresses in the concrete shell which are generally neglected in the design of such structures. It is assumed that such tensile radial stresses are small as such no radial reinforcement is provided for this purpose. But recent instances of significant delaminations in Crystal River Unit 3 in Florida have elevated the need for reevaluation of the radial tension issue in prestressed containment. Note that currently there are no well accepted industry standards for design and detailing of radial reinforcement. This paper discusses the issue of radial tension in prestressed cylindrical and dome shaped structures and proposes formulae to calculate radial stresses. A practical example is presented to illustrate the use of the proposed method which is then verified by using state of art finite element analysis. This paper also provides some practical design consideration for detailing of radial reinforcement in prestressed containments.

  9. Motion of a particle in a radial space-charge field and in an axial magnetic field; Le mouvement d'une particule dans un champ de charge d'espace radial et un champ magnetique axial

    Energy Technology Data Exchange (ETDEWEB)

    Canobbio, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires. Services de Physique Appliquee, Service d' Ionique Generale, Section d' Etudes des Interactions Ondes Plasmas; Finzi, U [Institut de Physique Theorique de Milan (Italy)

    1966-07-01

    The motion of a charged particle in an axial uniform steady magnetic field, under the action of a radial space charge is calculated. A cylindrical symmetric charge distribution similar to the one which is observed in HF plasma accelerators is assumed. The particle motion is discussed with the method of effective potentials. A radial acceleration of ions is shown to be possible if the space charge density is sufficiently high. The displacement of the turning points of the trajectories due to the electrostatic field is calculated in the low plasma density approximation. Finally a HF circularly polarized electric field is introduced, the shift in cyclotron resonance is calculated and a low frequency resonance is found to be possible. (authors) [French] On etudie le mouvement d'une particule dans un champ magnetique axial uniforme et constant en presence d'un champ de charge d'espace radial. On considere une distribution de charge a symetrie cylindrique, semblable a celle qu'on observe dans les accelerateurs de plasma a H.F. On se sert des potentiels effectifs pour discuter les caracteristiques du mouvement. Une acceleration radiale des ions est possible lorsque la densite de charge est assez elevee. On calcule aussi les deplacements des points de rebroussement des trajectoires produits par un champ electrostatique faible. On introduit enfin un champ electrique HF polarise circulairement et on calcule le deplacement de la resonance de cyclotron du au champ de charge d'espace. En meme temps on voit apparaitre dans l'energie cinetique de la particule une resonance a basse frequence. (auteurs)

  10. Methods and apparatus for radially compliant component mounting

    Science.gov (United States)

    Bulman, David Edward [Cincinnati, OH; Darkins, Jr., Toby George; Stumpf, James Anthony [Columbus, IN; Schroder, Mark S [Greenville, SC; Lipinski, John Joseph [Simpsonville, SC

    2012-03-27

    Methods and apparatus for a mounting assembly for a liner of a gas turbine engine combustor are provided. The combustor includes a combustor liner and a radially outer annular flow sleeve. The mounting assembly includes an inner ring surrounding a radially outer surface of the liner and including a plurality of axially extending fingers. The mounting assembly also includes a radially outer ring coupled to the inner ring through a plurality of spacers that extend radially from a radially outer surface of the inner ring to the outer ring.

  11. Manipulation of radial-variant polarization for creating tunable bifocusing spots.

    Science.gov (United States)

    Gu, Bing; Pan, Yang; Wu, Jia-Lu; Cui, Yiping

    2014-02-01

    We propose and generate a new radial-variant vector field (RV-VF) with a distribution of states of polarization described by the square of the radius and exploit its focusing property. Theoretically, we present the analytical expressions for the three-dimensional electric field of the vector field focused by a thin lens under the nonparaxial and paraxial approximations based on the vectorial Rayleigh-Sommerfeld formulas. Numerical simulations indicate that this focused field exhibits bifocusing spots along the optical axis. The underlying mechanism for generating the bifocusing property is analyzed in detail. We give the analytical formula for the interval between two foci. Experimentally, we generate the RV-VFs with alterable topological charge and demonstrate that the interval between two foci is controllable by tuning the radial topological charge. This particular focal field has specific applications for biparticle trapping, manipulating, alignment, transportation, and accelerating along the optical axis.

  12. Low temperature treatment affects concentration and distribution of chrysanthemum stunt viroid in Argyranthemum

    Directory of Open Access Journals (Sweden)

    Zhibo eZhang

    2016-03-01

    Full Text Available Chrysanthemum stunt viroid (CSVd can infect Argyranthemum and cause serious economic loss. Low temperature treatment combined with meristem culture has been applied to eradicate viroids from their hosts, but without success in eliminating CSVd from diseased Argyranthemum. The objectives of this work were to investigate 1 the effect of low temperature treatment combined with meristem culture on elimination of CSVd, 2 the effect of low temperature treatment on CSVd distribution pattern in shoot apical meristem (SAM, and 3 CSVd distribution in flowers and stems of two infected Argyranthemum cultivars. After treatment with low temperature combined with meristem tip culture, two CSVd-free plants were found in ‘Border Dark Red’, but none in ‘Yellow Empire’. With the help of in situ hybridization, we found that CSVd distribution patterns in the SAM showed no changes in diseased ‘Yellow Empire’ following 5oC treatment, compared with non-treated plants. However, the CSVd-free area in SAM was enlarged in diseased ‘Border Dark Red’ following prolonged 5oC treatment. Localization of CSVd in the flowers and stems of infected ‘Border Dark Red’ and ‘Yellow Empire’ indicated that seeds could not transmit CSVd in these two cultivars, and CSVd existed in phloem. Results obtained in the study contributed to better understanding of the distribution of CSVd in systemically infected plants and the combination of low temperature treatment and meristem tip culture for production of viroid-free plants.

  13. WIYN Open Cluster Study. XXXII. Stellar Radial Velocities in the Old Open Cluster NGC 188

    Science.gov (United States)

    Geller, Aaron M.; Mathieu, Robert D.; Harris, Hugh C.; McClure, Robert D.

    2008-06-01

    We present the results of our ongoing radial-velocity (RV) survey of the old (7 Gyr) open cluster NGC 188. Our WIYN 3.5 m data set spans a time baseline of 11 years, a magnitude range of 12 =3 measurements, finding 473 to be likely cluster members. We detect 124 velocity-variable cluster members, all of which are likely to be dynamically hard-binary stars. Using our single member stars, we find an average cluster radial velocity of -42.36 ± 0.04 km s-1. We use our precise RV and proper-motion membership data to greatly reduce field-star contamination in our cleaned color-magnitude diagram, from which we identify six stars of note that lie far from a standard single-star isochrone. We present a detailed study of the spatial distribution of cluster-member populations, and find the binaries to be centrally concentrated, providing evidence for the presence of mass segregation in NGC 188. We observe the BSs to populate a bimodal spatial distribution that is not centrally concentrated, suggesting that we may be observing two populations of BSs in NGC 188, including a centrally concentrated distribution as well as a halo population. Finally, we find NGC 188 to have a global RV dispersion of 0.64 ± 0.04 km s-1, which may be inflated by up to 0.23 km s-1 from unresolved binaries. When corrected for unresolved binaries, the NGC 188 RV dispersion has a nearly isothermal radial distribution. We use this mean-corrected velocity dispersion to derive a virial mass of 2300 ± 460 M sun .

  14. Performance Improvement of Raman Distributed Temperature System by Using Noise Suppression

    Science.gov (United States)

    Li, Jian; Li, Yunting; Zhang, Mingjiang; Liu, Yi; Zhang, Jianzhong; Yan, Baoqiang; Wang, Dong; Jin, Baoquan

    2018-06-01

    In Raman distributed temperature system, the key factor for performance improvement is noise suppression, which seriously affects the sensing distance and temperature accuracy. Therefore, we propose and experimentally demonstrate dynamic noise difference algorithm and wavelet transform modulus maximum (WTMM) to de-noising Raman anti-Stokes signal. Experimental results show that the sensing distance can increase from 3 km to 11.5 km and the temperature accuracy increases to 1.58 °C at the sensing distance of 10.4 km.

  15. Statistical modeling of urban air temperature distributions under different synoptic conditions

    Science.gov (United States)

    Beck, Christoph; Breitner, Susanne; Cyrys, Josef; Hald, Cornelius; Hartz, Uwe; Jacobeit, Jucundus; Richter, Katja; Schneider, Alexandra; Wolf, Kathrin

    2015-04-01

    Within urban areas air temperature may vary distinctly between different locations. These intra-urban air temperature variations partly reach magnitudes that are relevant with respect to human thermal comfort. Therefore and furthermore taking into account potential interrelations with other health related environmental factors (e.g. air quality) it is important to estimate spatial patterns of intra-urban air temperature distributions that may be incorporated into urban planning processes. In this contribution we present an approach to estimate spatial temperature distributions in the urban area of Augsburg (Germany) by means of statistical modeling. At 36 locations in the urban area of Augsburg air temperatures are measured with high temporal resolution (4 min.) since December 2012. These 36 locations represent different typical urban land use characteristics in terms of varying percentage coverages of different land cover categories (e.g. impervious, built-up, vegetated). Percentage coverages of these land cover categories have been extracted from different sources (Open Street Map, European Urban Atlas, Urban Morphological Zones) for regular grids of varying size (50, 100, 200 meter horizonal resolution) for the urban area of Augsburg. It is well known from numerous studies that land use characteristics have a distinct influence on air temperature and as well other climatic variables at a certain location. Therefore air temperatures at the 36 locations are modeled utilizing land use characteristics (percentage coverages of land cover categories) as predictor variables in Stepwise Multiple Regression models and in Random Forest based model approaches. After model evaluation via cross-validation appropriate statistical models are applied to gridded land use data to derive spatial urban air temperature distributions. Varying models are tested and applied for different seasons and times of the day and also for different synoptic conditions (e.g. clear and calm

  16. Computer model analysis of the radial artery pressure waveform.

    Science.gov (United States)

    Schwid, H A; Taylor, L A; Smith, N T

    1987-10-01

    Simultaneous measurements of aortic and radial artery pressures are reviewed, and a model of the cardiovascular system is presented. The model is based on resonant networks for the aorta and axillo-brachial-radial arterial system. The model chosen is a simple one, in order to make interpretation of the observed relationships clear. Despite its simplicity, the model produces realistic aortic and radial artery pressure waveforms. It demonstrates that the resonant properties of the arterial wall significantly alter the pressure waveform as it is propagated from the aorta to the radial artery. Although the mean and end-diastolic radial pressures are usually accurate estimates of the corresponding aortic pressures, the systolic pressure at the radial artery is often much higher than that of the aorta due to overshoot caused by the resonant behavior of the radial artery. The radial artery dicrotic notch is predominantly dependent on the axillo-brachial-radial arterial wall properties, rather than on the aortic valve or peripheral resistance. Hence the use of the radial artery dicrotic notch as an estimate of end systole is unreliable. The rate of systolic upstroke, dP/dt, of the radial artery waveform is a function of many factors, making it difficult to interpret. The radial artery waveform usually provides accurate estimates for mean and diastolic aortic pressures; for all other measurements it is an inadequate substitute for the aortic pressure waveform. In the presence of low forearm peripheral resistance the mean radial artery pressure may significantly underestimate the mean aortic pressure, as explained by a voltage divider model.

  17. Summer temperature metrics for predicting brook trout (Salvelinus fontinalis) distribution in streams

    Science.gov (United States)

    Parrish, Donna; Butryn, Ryan S.; Rizzo, Donna M.

    2012-01-01

    We developed a methodology to predict brook trout (Salvelinus fontinalis) distribution using summer temperature metrics as predictor variables. Our analysis used long-term fish and hourly water temperature data from the Dog River, Vermont (USA). Commonly used metrics (e.g., mean, maximum, maximum 7-day maximum) tend to smooth the data so information on temperature variation is lost. Therefore, we developed a new set of metrics (called event metrics) to capture temperature variation by describing the frequency, area, duration, and magnitude of events that exceeded a user-defined temperature threshold. We used 16, 18, 20, and 22°C. We built linear discriminant models and tested and compared the event metrics against the commonly used metrics. Correct classification of the observations was 66% with event metrics and 87% with commonly used metrics. However, combined event and commonly used metrics correctly classified 92%. Of the four individual temperature thresholds, it was difficult to assess which threshold had the “best” accuracy. The 16°C threshold had slightly fewer misclassifications; however, the 20°C threshold had the fewest extreme misclassifications. Our method leveraged the volumes of existing long-term data and provided a simple, systematic, and adaptable framework for monitoring changes in fish distribution, specifically in the case of irregular, extreme temperature events.

  18. On Chaotic Behavior of Temperature Distribution in a Heat Exchanger

    Science.gov (United States)

    Bagyalakshmi, Morachan; Gangadharan, Saisundarakrishnan; Ganesh, Madhu

    The objective of this paper is to introduce the notion of fractional derivatives in the energy equations and to study the chaotic nature of the temperature distribution in a heat exchanger with variation of temperature dependent transport properties. The governing fractional partial differential equations are transformed to a set of recurrence relations using fractional differential transform method and solved using inverse transform. The approximate analytical solution obtained by the proposed method has good agreement with the existing results.

  19. Influences of climate on the radial growth of lodgepole pine in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Chhin, S.; Lieffers, V.J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Renewable Resources; Hogg, E.H. [Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB (Canada); Huang, S. [Alberta Sustainable Resource Development, Edmonton, AB (Canada). Forest Management Branch

    2008-02-15

    The forests of the Cordilleran region were used to document past relationships between tree growth and climate. Radial growth and climate relationships of lodgepole pines were examined across a network of 17 sites in Alberta over a distance of 1100 km. Pine sites were selected from a permanent plot database covering the predominant latitudinal and elevational range of lodgepole pines. An average of 21 dominant and co-dominant trees were sampled in a 50 m buffer zone. Ring-width series were detrended in 3 stages using negative exponential curves, linear regression, and low frequency standardized series (LFS). Each LFS series was detrended with a cubic-smoothing spline. Autocorrelation in each series was removed via autoregressive (AR) modelling resulting in high frequency residual series. High frequency residual (HFR) site chronologies were constructed by averaging HFR series developed at each site. Primary climate variables included mean daily minimum and maximum temperatures for each month and total monthly precipitation. Relationships between the different chronology types were then examined. Results of the study demonstrated that cool and moist conditions during the later summer months led to improved radial growth levels during the following years. Warm, dry winters and warm conditions during the autumn of the year in which the ring was formed also promoted tree growth. Results suggested that climatic warming and drying have opposing effects. It was concluded that future impacts on lodgepole pine radial growth will depend on the pattern and magnitude of changes in temperature and precipitation in each season. 55 refs., 3 tabs., 8 figs.

  20. Temperature distributions in boreholes of a vertical ground-coupled heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Esen, Hikmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey); Inalli, Mustafa [Department of Mechanical Engineering, Faculty of Engineering, Firat University, 23279 Elazig (Turkey); Esen, Yuksel [Department of Construction Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

    2009-12-15

    The objective of this study is to show the temperature distribution development in the borehole of the ground-coupled heat pump systems (GCHPs) with time. The time interval for the study is 48 h. The vertical GCHP system using R-22 as refrigerant has a three single U-tube ground heat exchanger (GHE) made of polyethylene pipe with a 40 mm outside diameter. The GHE was placed in a vertical borehole (VB) with 30 (VB1), 60 (VB2) and 90 (VB3) m depths and 150 mm diameters. The experimental results were obtained in cooling and heating seasons of 2006-2007. A two-dimensional finite element model (FEM) was developed to simulate temperature distribution development in the soil surrounding the GHEs of GCHPs operating in the cooling and the heating modes. The finite element modelling of the GCHP system was performed using the ANSYS code. The FEM incorporated pipes, the grout and the surrounding formation. From the cases studied, this approach appears to be the most promising for estimation the temperature distribution response of GHEs to thermal loading. (author)