Form of multicomponent Fickian diffusion coefficients matrix
International Nuclear Information System (INIS)
Wambui Mutoru, J.; Firoozabadi, Abbas
2011-01-01
Highlights: → Irreversible thermodynamics establishes form of multicomponent diffusion coefficients. → Phenomenological coefficients and thermodynamic factors affect sign of diffusion coefficients. → Negative diagonal elements of diffusion coefficients matrix can occur in non-ideal mixtures. → Eigenvalues of the matrix of Fickian diffusion coefficients may not be all real. - Abstract: The form of multicomponent Fickian diffusion coefficients matrix in thermodynamically stable mixtures is established based on the form of phenomenological coefficients and thermodynamic factors. While phenomenological coefficients form a symmetric positive definite matrix, the determinant of thermodynamic factors matrix is positive. As a result, the Fickian diffusion coefficients matrix has a positive determinant, but its elements - including diagonal elements - can be negative. Comprehensive survey of reported diffusion coefficients data for ternary and quaternary mixtures, confirms that invariably the determinant of the Fickian diffusion coefficients matrix is positive.
Form coefficient of helical toroidal solenoids
International Nuclear Information System (INIS)
Amelin, V.Z.; Kunchenko, V.B.
1982-01-01
For toroidal solenoids with continuous spiral coil, winded according to the laws of equiinclined and simple cylindrical spirals with homogeneous, linearly increasing to the coil periphery and ''Bitter'' distribution of current density, the analytical expressions for the dependence between capacity consumed and generated magnetic field, expressions for coefficients of form similar to Fabry coefficient for cylindrical solenoids are obtained and dependence of the form coefficient and relative volume of solenoid conductor on the number of revolutions of screw line per one circumvention over the large torus radius is also investigated. Analytical expressions of form coefficients and graphical material permit to select the optimum geometry as to capacity consumed both for spiral (including ''force-free'') and conventional toroidal solenoids of magnetic systems in thermonulear installations
Modified loss coefficients in the determination of optimum generation scheduling
Energy Technology Data Exchange (ETDEWEB)
Hazarika, D.; Bordoloi, P.K. (Assam Engineering Coll. (IN))
1991-03-01
A modified method has been evolved to form the loss coefficients of an electrical power system network by decoupling load and generation and thereby creating additional fictitious load buses. The system losses are then calculated and co-ordinated to arrive at an optimum scheduling of generation using the standard co-ordination equation. The method presented is superior to the ones currently available, in that it is applicable to a multimachine system with random variation of load and it accounts for limits in plant generations and line losses. The precise nature of results and the economy in the cost of energy production obtained by this method is quantified and presented. (author).
Analytical prediction of fuel assembly spacer grid loss coefficient
International Nuclear Information System (INIS)
Lim, J. S.; Nam, K. I.; Park, S. K.; Kwon, J. T.; Park, W. J.
2002-01-01
The analytical prediction model of the fuel assembly spacer grid pressure loss coefficient has been studied. The pressure loss of gap between the test section wall and spacer grid was separated from the current model and the different friction drag coefficient on spacer straps from high Reynolds number region were used to low Reynolds number region. The analytical model has been verified based on the hydraulic pressure drop test results for the spacer grids of three types for 5x5, 16x16(or 17x17) arrays. The analytical model predicts the pressure loss coefficients obtained from test results within the maximum errors of 12% and 7% for 5x5 test bundle and full size bundle, respectively, at Reynolds number 500,000 of the core operating condition. This result shows that the analytical model can be used for research and design change of the nuclear fuel assembly
Transmission Loss Calculation using A and B Loss Coefficients in Dynamic Economic Dispatch Problem
Jethmalani, C. H. Ram; Dumpa, Poornima; Simon, Sishaj P.; Sundareswaran, K.
2016-04-01
This paper analyzes the performance of A-loss coefficients while evaluating transmission losses in a Dynamic Economic Dispatch (DED) Problem. The performance analysis is carried out by comparing the losses computed using nominal A loss coefficients and nominal B loss coefficients in reference with load flow solution obtained by standard Newton-Raphson (NR) method. Density based clustering method based on connected regions with sufficiently high density (DBSCAN) is employed in identifying the best regions of A and B loss coefficients. Based on the results obtained through cluster analysis, a novel approach in improving the accuracy of network loss calculation is proposed. Here, based on the change in per unit load values between the load intervals, loss coefficients are updated for calculating the transmission losses. The proposed algorithm is tested and validated on IEEE 6 bus system, IEEE 14 bus, system IEEE 30 bus system and IEEE 118 bus system. All simulations are carried out using SCILAB 5.4 (www.scilab.org) which is an open source software.
Interpretation of Nonlinear Well Loss Coefficients for Rorabaugh (1953) Method.
Kurtulus, B.; Yaylım, T. N.; Avşar
2016-12-01
Step drawdown test (SDT) are essential for hydrogeologist to determine aquifer loss and well loss parameters. In a SDT, different series of constant-discharges with incremental rates are conducted to obtain incremental drawdown into the pumping well. Pumping well efficiency (if the well is properly developed and designed), aquifer characteristics (transmissivity, storativity) and discharge-drawdown relationship can be derived from SDT. The well loss parameter directly associate with the well efficiency. The main problem is to determine the correct well loss parameter in order to estimate aquifer characteristics. Walton (1962) stated that the interpretation of the well efficiency is possible to determine the nonlinear head loss coefficient (C) with p equals to 2 and Walton (1962) presented a criteria that suggested the following terms: If C is less than 1800 m2/s5, the is properly developed and designed, If C is ranged from 1800 m2/s5 to 3600 m2/s5, the well has a mild deterioration, If C is greater than 3600 m2/s5, the well has a severe clogging. Until now, several well-known computer techniques such as Aqutesolv, AquiferWin32 , AquifertestPro can be found in the literature to evaluate well efficiency when exponential parameter (p) equals to 2. However, there exist a lack of information to evaluate well efficiency for different number of exponential parameter (p). Strategic Water Storage & Recovery (SWSR) Project in Liwa, Abu Dhabi is the leading and unique hydrogeology project in the world because of its both financial and scientific dimension. A total of 315 recovery wells have been drilled in pursuance of the scope of the SWSR project. A Universal Well Efficiency Criteria (UWEC) is developed using 315 Step Drawdown Test (SDT). UWEC is defined for different number of head loss equation coefficients. The results reveal that there is a strong correlation between non-linear well loss coefficient (C) and exponential parameter (p) up to a coefficient of determination
The Bach equations in spin-coefficient form
Forbes, Hamish
2018-06-01
Conformal gravity theories are defined by field equations that determine only the conformal structure of the spacetime manifold. The Bach equations represent an early example of such a theory, we present them here in component form in terms of spin- and boost-weighted spin-coefficients using the compacted spin-coefficient formalism. These equations can be used as an efficient alternative to the standard tensor form. As a simple application we solve the Bach equations for pp-wave and static spherically symmetric spacetimes.
Effect of rolling motion on the expansion and contraction loss coefficients
International Nuclear Information System (INIS)
Yan, B.H.; Gu, H.Y.
2013-01-01
Highlights: ► The expansion and contraction loss coefficients in rolling motion are analyzed. ► Effects of rolling motion on the expansion and contraction loss coefficients are different. ► The spanwise and transverse additional forces contribute slightly to the local loss. ► The oscillations of loss coefficients increase as the strengthening of rolling motion. - Abstract: The sudden expansion and sudden contraction loss coefficients in rolling motion are investigated with CFD code FLUENT. The calculation results are validated with experimental and theoretical results in steady state. The effects of rolling motion on the expansion and contraction loss coefficients are different. The effects of spanwise and transverse additional forces on the expansion and contraction loss coefficients are weak. The effect of velocity oscillation on the contraction loss coefficient is more significant than that on the expansion loss coefficient. The oscillation of local loss coefficient also becomes more and more irregular as the strengthening of rolling motion
International Nuclear Information System (INIS)
Chae, Hee Taek; Lee, Kye Hong
1999-06-01
MATRA-h, a HANARO subchannel analysis computer code, is used to evaluate thermal margin of the HANARO fuel. It's capability includes the assessments of CHF, ONB margin, and fuel temperature. In this report, basic input data and core design parameters required to perform the subchannel analysis with MATRA-h code are collected. These data include the subchannel geometric data, thermal-hydraulic correlations, empirical constants and material properties. The friction and form loss coefficients of the fuel assemblies were determined based on the results of the pressure drop test. At the same time, different form loss coefficients at the end plates and spacers are evaluated for various subchannels. The adequate correlations are applied to the evaluation of the form loss coefficients for various subchannels, which are corrected by measured values in order to have a same pressure drop at each flow channel. These basic input data and design parameters described in this report will be applied usefully to evaluate the thermal margin of the HANARO fuel. (author). 11 refs., 13 tabs., 11 figs
Evaluation of coefficient of friction in bulk metal forming
Solhjoo, Soheil
In this study an upper bound analysis for cylindrical "Barrel Compression Test" (BCT) is developed. BCT method is a very simple method which can be utilized in order to evaluate quantitatively the coefficient of friction by means of just one cylindrical specimen in an upsetting test. The method is
Evaluation of coefficient of friction in bulk metal forming
Solhjoo, Soheil
2014-01-01
In this study an upper bound analysis for cylindrical "Barrel Compression Test" (BCT) is developed. BCT method is a very simple method which can be utilized in order to evaluate quantitatively the coefficient of friction by means of just one cylindrical specimen in an upsetting test. The method is checked by a series of finite element method (FEM) simulations and by means of the results of FEM simulations the method is modified.
Preliminary Experimental Study on Pressure Loss Coefficients of Exhaust Manifold Junction
Directory of Open Access Journals (Sweden)
Xiao-lu Lu
2014-01-01
Full Text Available The flow characteristic of exhaust system has an important impact on inlet boundary of the turbine. In this paper, high speed flow in a diesel exhaust manifold junction was tested and simulated. The pressure loss coefficient of the junction flow was analyzed. The steady experimental results indicated that both of static pressure loss coefficients L13 and L23 first increased and then decreased with the increase of mass flow ratio of lateral branch and public manifold. The total pressure loss coefficient K13 always increased with the increase of mass flow ratio of junctions 1 and 3. The total pressure loss coefficient K23 first increased and then decreased with the increase of mass flow ratio of junctions 2 and 3. These pressure loss coefficients of the exhaust pipe junctions can be used in exhaust flow and turbine inlet boundary conditions analysis. In addition, simulating calculation was conducted to analyze the effect of branch angle on total pressure loss coefficient. According to the calculation results, total pressure loss coefficient was almost the same at low mass flow rate of branch manifold 1 but increased with lateral branch angle at high mass flow rate of branch manifold 1.
Effects of the blockage ratio of a valve disk on loss coefficient in a butterfly valve
International Nuclear Information System (INIS)
Rho, Hyung Joon; Lee, Jee Keun; Choi, Hee Joo
2008-01-01
The loss coefficient of the butterfly valve which allows partial opening of the valve at closed position and is applicable to the small-sized pipe system with the diameter of 1 inch was measured for the variation of the valve disk blockage ratio. Two different types of the valve disk configuration to adjust the blockage ratio were considered. One was the solid type valve disk of which the diameter was changed into the smaller size rather than the pipe diameter, and the other was the perforate type valve disk on which some holes were perforated. The results from two types of valve disk were compared to identify their characteristics in the loss coefficient distributions. The loss coefficient and the controllable angle of the valve disk were decreased exponentially with the decrease of the blockage ratio. In addition, the perforate valve disk had the effect on the higher loss coefficient rather than the solid type valve disk
Monitoring water loss form fresh concrete
DEFF Research Database (Denmark)
Jensen, Ole Mejlhede
2006-01-01
Desiccation of concrete before or during setting may lead to detrimental plastic shrinkage cracking in the concrete surface zone. Cracking due to plastic shrinkage is a major technological problem for any concrete, however, modern high-performance concretes are especially susceptible to this...... determination of the evaporation loss from hardening concrete and thus better possibility for preventing curing problems, including detrimental crack damage due to plastic shrinkage....
Measurement and CFD calculation of spacer loss coefficient for a tight-lattice fuel bundle
International Nuclear Information System (INIS)
In, Wang Kee; Shin, Chang Hwan; Kwack, Young Kyun; Lee, Chi Young
2015-01-01
Highlights: • Experiment and CFD analysis evaluated the pressure drop in a spacer grid. • The measurement and CFD errors for the spacer loss coefficient were estimated. • The spacer loss coefficient for the dual-cooled annular fuel bundle was determined. • The CFD prediction agrees with the measured spacer loss coefficient within 8%. - Abstract: An experiment and computational fluid dynamics (CFD) analysis were performed to evaluate the pressure drop in a spacer grid for a dual-cooled annular fuel (DCAF) bundle. The DCAF bundle for the Korean optimum power reactor (OPR1000) is a 12 × 12 tight-lattice rod array with a pitch-to-diameter ratio of 1.08 owing to a larger outer diameter of the annular fuel rod. An experiment was conducted to measure the pressure drop in spacer grid for the DCAF bundle. The test bundle is a full-size 12 × 12 rod bundle with 11 spacer grid. The test condition covers a Reynolds number range of 2 × 10 4 –2 × 10 5 by changing the temperature and flow rate of water. A CFD analysis was also performed to predict the pressure drop through a spacer grid using the full-size and partial bundle models. The pressure drop and loss coefficient of a spacer grid were predicted and compared with the experimental results. The CFD predictions of spacer pressure drop and loss coefficient agree with the measured values within 8%. The spacer loss coefficient for the DCAF bundle is estimated to be approximately 1.50 at a nominal operating condition of OPR1000, i.e., Re = 4 × 10 5
Assessment of the crossflow loss coefficient in Very High Temperature Reactor core - 15338
International Nuclear Information System (INIS)
Lee, S.N.; Tak, N.I.; Kim, M.H.; Noh, J.M.
2015-01-01
The Very High Temperature Reactor (VHTR) is a helium gas cooled and graphite moderated reactor. It was chosen as one of the Gen-4 reactors owing to its inherent safety. Various researches for prismatic gas-cooled reactors have been conducted for efficient and safe use. The prismatic VHTR consists of vertically stacked fuel blocks. Between the vertical fuel blocks, there is cross gap because of manufacturing tolerance or graphite change during the operation. This cross gap changes the coolant flow path, called a crossflow, which may affect the fuel temperature. Various tests and numerical studies have been conducted to predict the crossflow and loss coefficient. In the present study, the CFD calculation is conducted to draw the loss coefficient, and compared with Groehn, Kaburaki and General Atomics (GA) correlations. The results of the Groehn and Kaburaki correlations tend to decrease as the gap size increases, whereas the data of GA show the opposite. The loss coefficient given by the CFD calculation tends to maintain the regular value without regard to the gap size for the standard fuel block, like the Groehn correlation. However, the loss coefficient of the control fuel block increases as the gap size widens, like the GA results
Irrecoverable pressure loss coefficients for two out-of-plane piping elbows at high Reynolds number
Energy Technology Data Exchange (ETDEWEB)
Coffield, R.D.; Hammond, R.B.; McKeown, P.T.
1999-02-08
Pressure drops of multiple piping elbows were experimentally determined for high Reynolds number flows. The testing described has been performed in order to reduce uncertainties in the currently used methods for predicting irrecoverable pressure losses and also to provide a qualification database for computational fluid dynamics (CFD) computer codes. The earlier high Reynolds number correlations had been based on extrapolations over several orders of magnitude in Reynolds number from where the original database existed. Recent single elbow test data shows about a factor of two lower elbow pressure loss coefficient (at 40x 106 Reynolds number) than those from current correlations. This single piping elbow data has been extended in this study to a multiple elbow configuration of two elbows that are 90o out-of-plane relative to each other. The effects of separation distance and Reynolds number have been correlated and presented in a form that can be used for design application. Contrary to earlier extrapolations from low Reynolds numbers (Re c 1.0x 106), a strong Reynolds number dependence was found to exist. The combination of the high Reynolds number single elbow data with the multiple elbow interaction effects measured in this study shows that earlier design correlations are conservative by significant margins at high Reynolds numbers. Qualification of CFD predictions with this new high Reynolds number database will help guide the need for additional high Reynolds number testing of other piping configurations. The study also included velocity measurements at several positions downstream of the first and second test elbows using an ultrasonic flowmeter. Reasonable agreement after the first test elbow was found relative to flow fields that are known to exist from low Reynolds number visual tests and also from CFD predictions. This data should help to qualify CFD predictions of the three-dimensional flow stream downstream of the second test elbow.
Identifying the principal coefficient of parabolic equations with non-divergent form
International Nuclear Information System (INIS)
Jiang, L S; Bian, B J
2005-01-01
We deal with an inverse problem of determining a coefficient a(x, t) of principal part for second order parabolic equations with non-divergent form when the solution is known. Such a problem has important applications in a large fields of applied science. We propose a well-posed approximate algorithm to identify the coefficient. The existence, uniqueness and stability of such solutions a(x, t) are proved. A necessary condition which is a couple system of a parabolic equation and a parabolic variational inequality is deduced. Our numerical simulations show that the coefficient is recovered very well
Identifying the principal coefficient of parabolic equations with non-divergent form
Jiang, L. S.; Bian, B. J.
2005-01-01
We deal with an inverse problem of determining a coefficient a(x, t) of principal part for second order parabolic equations with non-divergent form when the solution is known. Such a problem has important applications in a large fields of applied science. We propose a well-posed approximate algorithm to identify the coefficient. The existence, uniqueness and stability of such solutions a(x, t) are proved. A necessary condition which is a couple system of a parabolic equation and a parabolic variational inequality is deduced. Our numerical simulations show that the coefficient is recovered very well.
A study on improvement of analytical prediction model for spacer grid pressure loss coefficients
International Nuclear Information System (INIS)
Lim, Jonh Seon
2002-02-01
Nuclear fuel assemblies used in the nuclear power plants consist of the nuclear fuel rods, the control rod guide tubes, an instrument guide tube, spacer grids,a bottom nozzle, a top nozzle. The spacer grid is the most important component of the fuel assembly components for thermal hydraulic and mechanical design and analyses. The spacer grids fixed with the guide tubes support the fuel rods and have the very important role to activate thermal energy transfer by the coolant mixing caused to the turbulent flow and crossflow in the subchannels. In this paper, the analytical spacer grid pressure loss prediction model has been studied and improved by considering the test section wall to spacer grid gap pressure loss independently and applying the appropriate friction drag coefficient to predict pressure loss more accurately at the low Reynolds number region. The improved analytical model has been verified based on the hydraulic pressure drop test results for the spacer grids of three types with 5x5, 16x16, 17x17 arrays, respectively. The pressure loss coefficients predicted by the improved analytical model are coincident with those test results within ±12%. This result shows that the improved analytical model can be used for research and design change of the nuclear fuel assembly
Directory of Open Access Journals (Sweden)
Serge B. Provost
2015-07-01
Full Text Available This paper provides a simplified representation of the exact density function of R, the sample correlation coefficient. The odd and even moments of R are also obtained in closed forms. Being expressed in terms of generalized hypergeometric functions, the resulting representations are readily computable. Some numerical examples corroborate the validity of the results derived herein.
Directory of Open Access Journals (Sweden)
T. Aly Saandy
2015-08-01
Full Text Available Abstract This article presents to an analytical calculation methodology of the Steinmetz coefficient applied to the prediction of Eddy current loss in a single-phase transformer. Based on the electrical circuit theory the active power consumed by the core is expressed analytically in function of the electrical parameters as resistivity and the geometrical dimensions of the core. The proposed modeling approach is established with the duality parallel series. The required coefficient is identified from the empirical Steinmetz data based on the experimented active power expression. To verify the relevance of the model validations both by simulations with two in two different frequencies and measurements were carried out. The obtained results are in good agreement with the theoretical approach and the practical results.
Sound absorption coefficient in situ: an alternative for estimating soil loss factors.
Freire, Rosane; Meletti de Abreu, Marco Henrique; Okada, Rafael Yuri; Soares, Paulo Fernando; GranhenTavares, Célia Regina
2015-01-01
The relationship between the sound absorption coefficient and factors of the Universal Soil Loss Equation (USLE) was determined in a section of the Maringá Stream basin, Paraná State, by using erosion plots. In the field, four erosion plots were built on a reduced scale, with dimensions of 2.0×12.5m. With respect to plot coverage, one was kept with bare soil and the others contained forage grass (Brachiaria), corn and wheat crops, respectively. Planting was performed without any type of conservation practice in an area with a 9% slope. A sedimentation tank was placed at the end of each plot to collect the material transported. For the acoustic system, pink noise was used in the measurement of the proposed monitoring, for collecting information on incident and reflected sound pressure levels. In general, obtained values of soil loss confirmed that 94.3% of material exported to the basin water came from the bare soil plot, 2.8% from the corn plot, 1.8% from the wheat plot, and 1.1% from the forage grass plot. With respect to the acoustic monitoring, results indicated that at 16kHz erosion plot coverage type had a significant influence on the sound absorption coefficient. High correlation coefficients were found in estimations of the A and C factors of the USLE, confirming that the acoustic technique is feasible for the determination of soil loss directly in the field. Copyright © 2014 Elsevier B.V. All rights reserved.
Row Reduced Echelon Form for Solving Fully Fuzzy System with Unknown Coefficients
Directory of Open Access Journals (Sweden)
Ghassan Malkawi
2014-08-01
Full Text Available This study proposes a new method for finding a feasible fuzzy solution in positive Fully Fuzzy Linear System (FFLS, where the coefficients are unknown. The fully fuzzy system is transferred to linear system in order to obtain the solution using row reduced echelon form, thereafter; the crisp solution is restricted in obtaining the positive fuzzy solution. The fuzzy solution of FFLS is included crisp intervals, to assign alternative values of unknown entries of fuzzy numbers. To illustrate the proposed method, numerical examples are solved, where the entries of coefficients are unknown in right or left hand side, to demonstrate the contributions in this study.
A Note On Signs Of Fourier Coefficients Of Two Cusp Forms
Indian Academy of Sciences (India)
10
Abstract. Kohnen and Sengupta showed that if two Hecke eigen cusp forms of weight k1 and k2 respectively with 1 < k1 < k2 over. Γ0(N ), have totally real algebraic Fourier coefficients {a(n)} and. {b(n)} respectively for n ≥ 1 with a(1) = 1 = b(1), then there exists an element σ of the absolute Galois group Gal(Q/Q) such.
International Nuclear Information System (INIS)
Bae, Youngmin; Kim, Young In
2014-01-01
Highlights: • Turbulent flow in axisymmetric sudden expansion with a chamfer is studied numerically. • Reynolds number dependency of the local loss coefficient is investigated. • Extended correlation is proposed for estimation of the local loss coefficient. - Abstract: This paper reports the pressure losses in turbulent flows through axisymmetric sudden expansions having a slight chamfer on the edge. A parametric study is performed for dimensionless chamfer lengths of 0–0.5, expansion ratios of 2–6, and chamfer angles of 0–45° in a Reynolds number range of 1 × 10 5 –8 × 10 5 . The chamfer effect on the expansion losses and its dependence on the Reynolds number are analyzed in detail along with a discussion of the relevant flow features. On the basis of numerical results, an existing correlation of the local loss coefficient is also extended to take into account the effect of the Reynolds number additionally
Numerical determination of lateral loss coefficients for subchannel analysis in nuclear fuel bundles
Energy Technology Data Exchange (ETDEWEB)
Sin Kim; Goon-Cherl Park [Seoul National Univ., Seoul (Korea, Republic of)
1995-09-01
An accurate prediction of cross-flow based on detailed knowledge of the velocity field in subchannels of a nuclear fuel assembly is of importance in nuclear fuel performance analysis. In this study, the low-Reynolds number {kappa}-{epsilon} turbulence model has been adopted in two adjacent subchannels with cross-flow. The secondary flow is estimated accurately by the anisotropic algebraic Reynolds stress model. This model was numerically calculated by the finite element method and has been verified successfully through comparison with existing experimental data. Finally, with the numerical analysis of the velocity field in such subchannel domain, an analytical correlation of the lateral loss coefficient is obtained to predict the cross-flow rate in subchannel analysis codes. The correlation is expressed as a function of the ratio of the lateral flow velocity to the donor subchannel axial velocity, recipient channel Reynolds number and pitch-to-diameter.
Separation coefficients of liquid-vapor in systems formed by yttrium chloride with some impurities
International Nuclear Information System (INIS)
Volkov, V.T.; Nikiforova, T.V.; Nisel'son, L.A.; Telegin, G.F.
1990-01-01
Using equilibrium Rayleigh distillation in the 800-950 deg C temperature range, separation coefficients of liquid-vapor for systems, formed by yttrium chloride with Co, Cr, Ni, Mn, Fe, Cu, Na, K, Mg, Ca, Li impurities are determined. The impurity concentration lies within 0.02-0.4 mass. % limits of each impurity, and total impurity concentration does not exceed 1 mass. %. The tested impurities, except for calcium, are more volatile than the base, yttrium trichloride. In most systems negative deviation from the Raoult's law is observed
Calculation and validation of heat transfer coefficient for warm forming operations
Omer, Kaab; Butcher, Clifford; Worswick, Michael
2017-10-01
In an effort to reduce the weight of their products, the automotive industry is exploring various hot forming and warm forming technologies. One critical aspect in these technologies is understanding and quantifying the heat transfer between the blank and the tooling. The purpose of the current study is twofold. First, an experimental procedure to obtain the heat transfer coefficient (HTC) as a function of pressure for the purposes of a metal forming simulation is devised. The experimental approach was used in conjunction with finite element models to obtain HTC values as a function of die pressure. The materials that were characterized were AA5182-O and AA7075-T6. Both the heating operation and warm forming deep draw were modelled using the LS-DYNA commercial finite element code. Temperature-time measurements were obtained from both applications. The results of the finite element model showed that the experimentally derived HTC values were able to predict the temperature-time history to within a 2% of the measured response. It is intended that the HTC values presented herein can be used in warm forming models in order to accurately capture the heat transfer characteristics of the operation.
International Nuclear Information System (INIS)
Tian Bo; Gao Yitian; Zhu Hongwu
2007-01-01
Symbolically investigated in this Letter is a variable-coefficient higher-order nonlinear Schroedinger (vcHNLS) model for ultrafast signal-routing, fiber laser systems and optical communication systems with distributed dispersion and nonlinearity management. Of physical and optical interests, with bilinear method extend, the vcHNLS model is transformed into a variable-coefficient bilinear form, and then an auto-Baecklund transformation is constructed. Constraints on coefficient functions are analyzed. Potentially observable with future optical-fiber experiments, variable-coefficient brightons are illustrated. Relevant properties and features are discussed as well. Baecklund transformation and other results of this Letter will be of certain value to the studies on inhomogeneous fiber media, core of dispersion-managed brightons, fiber amplifiers, laser systems and optical communication links with distributed dispersion and nonlinearity management
Large scale steam flow test: Pressure drop data and calculated pressure loss coefficients
International Nuclear Information System (INIS)
Meadows, J.B.; Spears, J.R.; Feder, A.R.; Moore, B.P.; Young, C.E.
1993-12-01
This report presents the result of large scale steam flow testing, 3 million to 7 million lbs/hr., conducted at approximate steam qualities of 25, 45, 70 and 100 percent (dry, saturated). It is concluded from the test data that reasonable estimates of piping component pressure loss coefficients for single phase flow in complex piping geometries can be calculated using available engineering literature. This includes the effects of nearby upstream and downstream components, compressibility, and internal obstructions, such as splitters, and ladder rungs on individual piping components. Despite expected uncertainties in the data resulting from the complexity of the piping geometry and two-phase flow, the test data support the conclusion that the predicted dry steam K-factors are accurate and provide useful insight into the effect of entrained liquid on the flow resistance. The K-factors calculated from the wet steam test data were compared to two-phase K-factors based on the Martinelli-Nelson pressure drop correlations. This comparison supports the concept of a two-phase multiplier for estimating the resistance of piping with liquid entrained into the flow. The test data in general appears to be reasonably consistent with the shape of a curve based on the Martinelli-Nelson correlation over the tested range of steam quality
Bisyarin, M A; Kotov, O I; Hartog, A H; Liokumovich, L B; Ushakov, N A
2017-06-01
The recently developed diffraction technique of analytical investigation of the Rayleigh backscattering produced by an incident fundamental mode in a multimode optical fiber with an arbitrary refractive index profile is supplemented by taking into account the Rayleigh scattering-loss coefficient, which could be variable within the fiber cross section. The relative changes in various radial and azimuthal modes' excitation levels, due to some typical radial dependences of this coefficient, are computed for the quadratic- and step-index fibers. It is stated that the excitation efficiency could either rise or decay for different modes. The effect of the variable Rayleigh scattering-loss coefficient is shown to be more noticeable in the fibers with a quadratic refractive index profile, whereas it is negligible in actual multimode step-index fibers.
Classification of distribution coefficient data by mineral components and chemical forms
International Nuclear Information System (INIS)
Takeda, Seiji; Kimura, Hideo; Matsuzuru, Hideo
1996-01-01
The use of distribution coefficient (Kd) in radionuclide transport model has been reported in a number of papers. However, Kd data cover a wide range even for a specific element. In this study the Kd data of neptunium, uranium and selenium, which are included in sorption database (SDB, OECD/NEA) of radionuclides, were classified by a solid phase and a dominant species in a solution. The aqueous species of these elements were estimated by a geochemical model. The Kd data classified by the analyzed speciation were tested by a nonparametric statistical method. The results of tests proved that the Kd data of neptunium or uranium, which covered a wide range, were influenced by the supersaturation of Np(OH) 4 (s) or schoepite. The Kd data of neptunium could be classified by the dominant aqueous species, NpO 2 + , NpO 2 CO 3 - , NpO 2 OH(aq) and Np(OH) 4 (aq). The Kd data of these four dominant species which are not equilibrated with supersaturated Np(OH) 4 (s) are less than 100 ml/g. The analyzed aqueous species of uranium were UO 2 (OH) 2 (aq) and UO 2 (CO 3 ) n 2-2n (n=2,3) in hexavalent state. It is suggested that the distribution coefficient of neptunium and uranium depends on dominant aqueous species or charged species, i.e., cationic, anionic and nonionic forms. The dominant aqueous species of selenium are HSe - , HSeO 3 - , SeO 3 2- and SeO 4 2- . The result of the nonparametric statistical test shows that the Kd value of HSeO 3 - is higher than of other anionic forms. However, the influence of the species, HSe - , SeO 3 2- and SeO 4 2- , on Kd values is not clearly identified. Considering the dominant species, the Kd of elements are in ranges of 1 to 2 orders of magnitude being in general narrower than those classified by mineral and rock types. (author)
The impact of fuel temperature reactivity coefficient on loss of reactivity control accident
International Nuclear Information System (INIS)
Park, J. H.; Ryu, E. H.; Song, Y. M.; Jung, J. Y.
2012-01-01
Nuclear reactors experience small power fluctuations or anticipated operational transients during even normal power operation. During normal operation, the reactivity is mainly controlled by liquid zone controllers, adjuster rods, mechanical control absorbers, and moderator poison. Even when the reactor power is increased abruptly and largely from an accident and when reactor control systems cannot be actuated quickly due to a fast transient, the reactor should be controlled and stabilized by its inherent safety parameter, such as a negative PCR (Power Coefficient of Reactivity) feedback. A PWR (Pressurized Water Reactor), it is well designed for the reactor to have a negative PCR so that the reactor can be safely shut down or stabilized whenever an abrupt reactivity insertion into the reactor core occurs or the reactor power is abruptly increased. However, it is known that a CANDU reactor has a small amount of PCR, as either negative or positive, because of the different design basis and safety concepts from a PWR. CNSC's regulatory and safety regime has stated that; The PCR of CANDU reactors does not pose a significant risk. Consistent with Canadian nuclear safety requirements, nuclear power plants must have an appropriate combination of inherent and engineered safety features incorporated into the design of the reactor safety and control systems. A reactor design that has a PCR is quite acceptable provided that the reactor is stable against power fluctuations, and that the probability and consequences of any potential accidents that would be aggravated by a positive reactivity feedback are maintained within CNSCprescribed limits. Recently, it was issued licensing the refurbished Wolsong unit 1 in Korea to be operated continuously after its design lifetime in which the calculated PCR was shown to have a small positive value by applying the recent physics code systems, which are composed of WIMS IST, DRAGON IST, and RFSP IST. These code systems were transferred
Bruggeman, R.W.; Diamantis, N.
2016-01-01
The Fourier coefficient of a second order Eisenstein series is described as a shifted convolution sum. This description is used to obtain the spectral decomposition of and estimates for the shifted convolution sum.
Obtaining the general forms of the effective coefficients of laminate magneto-electro - elastic
International Nuclear Information System (INIS)
Cabañas, J. H.; Otero, A.; Castillero, B.; Rodríguez, R.
2008-01-01
In this work using the asymptotic homogenization method obtained general expressions for the calculation of the effective characteristics of magnetoelectro-elastic laminates with layers of any symmetry. You will reach an array of auxiliary functions for determining the effective coefficients for a serial connection and displays a result similar to the case of parallel connection.
International Nuclear Information System (INIS)
Ko II, B.; Park, J. P.; Jeong, J. H.
2008-01-01
Nuclear vendors and utilities perform lots of simulations and analyses in order to ensure the safe operation of nuclear power plants (NPPs). In general, the simulations are carried out using vendor-specific design codes and best-estimate system analysis codes and most of them were developed based on 1-dimensional lumped parameter models. These thermal-hydraulic system analysis codes require user input for pressure loss coefficient, k-factor; since they numerically solve Euler-equation. In spite of its high impact on the safety analysis results, there has not been good validation method for the selection of loss coefficient. During the past decade, however; computers, parallel computation methods, and 3-dimensional computational fluid dynamics (CFD) codes have been dramatically enhanced. It is believed to be beneficial to take advantage of advanced commercial CFD codes in safety analysis and design of NPP5. The present work aims to validate pressure loss coefficient evaluation for simple geometries and k-factor calculation for PWR based on CFD. The performances of standard k-ε model, RNG k-ε model, Reynolds stress model (RSM) on the simulation of pressure drop for simple geometry such as, or sudden-expansion, and sudden-contraction are evaluated. The calculated value was compared with pressure loss coefficient in handbook of hydraulic resistance. Then the present work carried out analysis for flow distribution in downcomer and lower plenum of Korean standard nuclear power plants (KSNPs) using STAR-CD. The lower plenum geometry of a PWR is very complicated since there are so many reactor internals, which hinders in CFD analysis for real reactor geometry up to now. The present work takes advantage of 3D CAD model so that real geometry of lower plenum is used. The results give a clear figure about flow fields in the reactor vessel, which is one of major safety concerns. The calculated pressure drop across downcomer and lower plenum appears to be in good agreement
Donnelly, Niall J; Randall, Clive A
2012-09-01
Sintering of lead zirconate titanate (PZT) at high temperatures results in loss of Pb unless an ambient Pb activity is maintained. The tell-tale sign of Pb loss is an increased conductivity, usually manifested in unacceptably high values of tanδ. The conductivity is caused by oxygen vacancies and/or electron holes which are a byproduct of Pb evaporation. In the first part of this paper, it is shown how impedance spectroscopy can be used to separate ionic and electronic conductivity in a properly designed sample by selection of appropriate boundary conditions. Subsequently, impedance is used to probe defect concentrations in PZT during prolonged annealing at 700°C. It is found that oxygen vacancies are generated during annealing in air but the rate of generation actually decreases upon lowering the ambient pO(2). These results are explained by a model of Pb evaporation which, in this case, leads predominantly to oxygen vacancy generation. In principle, this effect could be used to generate a specific vacancy concentration in similar Pb-based oxides.
Heat Transmission Coefficient Measurements in Buildings Utilizing a Heat Loss Measuring Device
DEFF Research Database (Denmark)
Sørensen, Lars Schiøtt
2013-01-01
Global energy efficiency can be obtained in two ordinary ways. One way is to improve the energy production and supply side, and the other way is, in general, to reduce the consumption of energy in society. This paper has focus on the latter and especially the consumption of energy for heating...... and cooling our houses. There is a huge energy-saving potential in this area for reducing both the global climate problems as well as economy challenges. Heating of buildings in Denmark accounts for approximately 40% of the entire national energy consumption. For this reason, a reduction of heat losses from...... building envelopes are of great importance in order to reach the Bologna CO2 emission reduction targets. Upgrading of the energy performance of buildings is a topic of huge global interest these years. Not only heating in the temperate and arctic regions are important, but also air conditioning...
Effect of the Contact Pressure on the Friction Loss Coefficient in a Micro Gap
International Nuclear Information System (INIS)
Nam, Ho Yun; Kim, Jong Man; Kim, Jong Bum; Lee, Yong Bum
2010-01-01
As one way to improve the reliability of a steam generator for a sodium-cooled fast reactor, a double-wall tube steam generator is being developed. The current development of the DWTSG focuses on the improvement of heat transfer capability for a double-wall tube and the development of a proper leak detection method for the double-wall tube during the operation of a reactor. In the conventional double wall tubes(DWT), the inner tube and the outer tube are made of the same material. When the temperature difference between the inner tube and the outer tube increases, the heat transfer efficiency decreases. To improve the heat transfer capability of a double wall tube, the inner tube is made of a material with a thermal expansion coefficient which is about 10 to 15% greater than that of the outer tube . For the on-line and real-time detection of whether the heat transfer tube is damaged or not, a detection method was developed by combining the heat transfer tube gaps and the detection holes meeting with a one-to-one correspondence in the lower tubesheet. In the pre-stressed DWT, there is a very small space due to the surface roughness of the inner wall and outer wall. Thus, if the outer wall is broken, the helium gas (2MPa) in the very narrow space is ejected into the sodium (0.1MPa), and if the inner wall is broken, the superheated gas (16.5MPa) is ejected into the space filled with helium gas. If the four grooves with 0.2-04mm depths are dug in the inner surface of the outer wall in order for the helium gas to flow easily, we can detect the leakage by checking the change of gas volume in the online groove
Energy Technology Data Exchange (ETDEWEB)
Gammon, M.; Shalchi, A., E-mail: andreasm4@yahoo.com [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada)
2017-10-01
In several astrophysical applications one needs analytical forms of cosmic-ray diffusion parameters. Some examples are studies of diffusive shock acceleration and solar modulation. In the current article we explore perpendicular diffusion based on the unified nonlinear transport theory. While we focused on magnetostatic turbulence in Paper I, we included the effect of dynamical turbulence in Paper II of the series. In the latter paper we assumed that the temporal correlation time does not depend on the wavenumber. More realistic models have been proposed in the past, such as the so-called damping model of dynamical turbulence. In the present paper we derive analytical forms for the perpendicular diffusion coefficient of energetic particles in two-component turbulence for this type of time-dependent turbulence. We present new formulas for the perpendicular diffusion coefficient and we derive a condition for which the magnetostatic result is recovered.
Can two dots form a Gestalt? Measuring emergent features with the capacity coefficient.
Hawkins, Robert X D; Houpt, Joseph W; Eidels, Ami; Townsend, James T
2016-09-01
While there is widespread agreement among vision researchers on the importance of some local aspects of visual stimuli, such as hue and intensity, there is no general consensus on a full set of basic sources of information used in perceptual tasks or how they are processed. Gestalt theories place particular value on emergent features, which are based on the higher-order relationships among elements of a stimulus rather than local properties. Thus, arbitrating between different accounts of features is an important step in arbitrating between local and Gestalt theories of perception in general. In this paper, we present the capacity coefficient from Systems Factorial Technology (SFT) as a quantitative approach for formalizing and rigorously testing predictions made by local and Gestalt theories of features. As a simple, easily controlled domain for testing this approach, we focus on the local feature of location and the emergent features of Orientation and Proximity in a pair of dots. We introduce a redundant-target change detection task to compare our capacity measure on (1) trials where the configuration of the dots changed along with their location against (2) trials where the amount of local location change was exactly the same, but there was no change in the configuration. Our results, in conjunction with our modeling tools, favor the Gestalt account of emergent features. We conclude by suggesting several candidate information-processing models that incorporate emergent features, which follow from our approach. Copyright © 2015 Elsevier Ltd. All rights reserved.
Harvey, Richard Paul, III
Releases of radioactive material have occurred at various Department of Energy (DOE) weapons facilities and facilities associated with the nuclear fuel cycle in the generation of electricity. Many different radionuclides have been released to the environment with resulting exposure of the population to these various sources of radioactivity. Radioiodine has been released from a number of these facilities and is a potential public health concern due to its physical and biological characteristics. Iodine exists as various isotopes, but our focus is on 131I due to its relatively long half-life, its prevalence in atmospheric releases and its contribution to offsite dose. The assumption of physical and chemical form is speculated to have a profound impact on the deposition of radioactive material within the respiratory tract. In the case of iodine, it has been shown that more than one type of physical and chemical form may be released to, or exist in, the environment; iodine can exist as a particle or as a gas. The gaseous species can be further segregated based on chemical form: elemental, inorganic, and organic iodides. Chemical compounds in each class are assumed to behave similarly with respect to biochemistry. Studies at Oak Ridge National Laboratories have demonstrated that 131I is released as a particulate, as well as in elemental, inorganic and organic chemical form. The internal dose estimate from 131I may be very different depending on the effect that chemical form has on fractional deposition, gas uptake, and clearance in the respiratory tract. There are many sources of uncertainty in the estimation of environmental dose including source term, airborne transport of radionuclides, and internal dosimetry. Knowledge of uncertainty in internal dosimetry is essential for estimating dose to members of the public and for determining total uncertainty in dose estimation. Important calculational steps in any lung model is regional estimation of deposition fractions
Arakeri, Jaywant H.; Shukla, Ratnesh K.
2013-08-01
An analysis of the energy budget for the general case of a body translating in a stationary fluid under the action of an external force is used to define a power loss coefficient. This universal definition of power loss coefficient gives a measure of the energy lost in the wake of the translating body and, in general, is applicable to a variety of flow configurations including active drag reduction, self-propulsion and thrust generation. The utility of the power loss coefficient is demonstrated on a model bluff body flow problem concerning a two-dimensional elliptical cylinder in a uniform cross-flow. The upper and lower boundaries of the elliptic cylinder undergo continuous motion due to a prescribed reflectionally symmetric constant tangential surface velocity. It is shown that a decrease in drag resulting from an increase in the strength of tangential surface velocity leads to an initial reduction and eventual rise in the power loss coefficient. A maximum in energetic efficiency is attained for a drag reducing tangential surface velocity which minimizes the power loss coefficient. The effect of the tangential surface velocity on drag reduction and self-propulsion of both bluff and streamlined bodies is explored through a variation in the thickness ratio (ratio of the minor and major axes) of the elliptical cylinders.
International Nuclear Information System (INIS)
Lee, Jeong-Hun; Cho, Hyoung-Kyu; Park, Goon-Cherl
2016-01-01
Highlights: • Cross flow experimental data are produced with wedge-shaped and parallel gaps. • The results of a CFD analysis and experimental data are in good agreement. • Pressure loss coefficient for the cross gap between fuel blocks in PMR200 is found. • A new correlation of the cross flow loss coefficient for PMR200 is proposed. - Abstract: The core of the very high temperature reactor (VHTR) PMR200 (a prismatic modular reactor rated at 200 MW of thermal power) consists of hexagonal prismatic fuel blocks and reflector blocks made of graphite. If the core bypass flow ratio increases, the coolant channel flow is decreased and can then lower the heat removal efficiency, resulting in a locally increased fuel block temperature. The coolant channels in the fuel blocks are connected to bypass gaps by the cross gap, complicating flow distribution in the VHTR core. Therefore, reliable estimation of the bypass flow is highly important for the design and safety analysis of the VHTR core. Because of the complexity of the core geometry and gap configuration, it is challenging to predict the flow distribution in the VHTR core. To analyze this flow distribution accurately, it is necessary to determine the cross flow phenomena, and the loss coefficient across the cross gap has to be evaluated to determine the flow distribution in the VHTR core when a lumped parameter code or a flow network analysis code that uses the correlation of the loss coefficient is employed. The purpose of this paper is to develop a loss coefficient correlation applicable to the cross gap in the PMR200 core. The cross flow was evaluated experimentally using the difference between the measured inlet and outlet mass flow rates. Next, the applicability of a commercial computational fluid dynamics (CFD) code, CFX 15, was confirmed by comparing the experimental data and CFD analysis results. To understand the cross flow phenomena, the loss coefficient was evaluated; in the high Reynolds number region
Energy Technology Data Exchange (ETDEWEB)
Lee, Jeong-Hun, E-mail: huny12@snu.ac.kr; Cho, Hyoung-Kyu, E-mail: chohk@snu.ac.kr; Park, Goon-Cherl, E-mail: parkgc@snu.ac.kr
2016-10-15
Highlights: • Cross flow experimental data are produced with wedge-shaped and parallel gaps. • The results of a CFD analysis and experimental data are in good agreement. • Pressure loss coefficient for the cross gap between fuel blocks in PMR200 is found. • A new correlation of the cross flow loss coefficient for PMR200 is proposed. - Abstract: The core of the very high temperature reactor (VHTR) PMR200 (a prismatic modular reactor rated at 200 MW of thermal power) consists of hexagonal prismatic fuel blocks and reflector blocks made of graphite. If the core bypass flow ratio increases, the coolant channel flow is decreased and can then lower the heat removal efficiency, resulting in a locally increased fuel block temperature. The coolant channels in the fuel blocks are connected to bypass gaps by the cross gap, complicating flow distribution in the VHTR core. Therefore, reliable estimation of the bypass flow is highly important for the design and safety analysis of the VHTR core. Because of the complexity of the core geometry and gap configuration, it is challenging to predict the flow distribution in the VHTR core. To analyze this flow distribution accurately, it is necessary to determine the cross flow phenomena, and the loss coefficient across the cross gap has to be evaluated to determine the flow distribution in the VHTR core when a lumped parameter code or a flow network analysis code that uses the correlation of the loss coefficient is employed. The purpose of this paper is to develop a loss coefficient correlation applicable to the cross gap in the PMR200 core. The cross flow was evaluated experimentally using the difference between the measured inlet and outlet mass flow rates. Next, the applicability of a commercial computational fluid dynamics (CFD) code, CFX 15, was confirmed by comparing the experimental data and CFD analysis results. To understand the cross flow phenomena, the loss coefficient was evaluated; in the high Reynolds number region
International Nuclear Information System (INIS)
Marten, K.; Yonekawa, S.; Hoffmann, H.
1987-05-01
Advanced pressurized water reactors as well as sodium cooled fast reactors, in their breeding and absorber elements, use tightly packed rod bundles with hexagonally arranged rods. Helical wires or helical fins serve as spacers. The pressure loss coefficients of twelve bundles with helical wires were determined systematically in water experiments. High measuring accuracy was achieved by very precise fabrication of the bundles and the shroud as well as by investigations of the proper measuring techniques. The results show a dependency of the loss coefficients on the Reynolds number and on the P/D and H/D ratios of the bundles. These results together with available systematic experimental results of investigations at P/D > 1.1 were used to develop a correlation to determine the pressure loss coefficients of tightly and widely packed hexagonally arranged rod bundles with helical wire spacers. These correlations were used to recalculate and compare results of pressure loss investigations found in the literature; good agreement was demonstrated. Hence, calculation methods exist for a broad range of applications to determine the pressure loss coefficients of hexagonally arranged rod bundles with helical wires for spacers. (orig./HP) [de
A research on determining the friction losses formed in the small ...
African Journals Online (AJOL)
fastest way is to make use of the values given in the tables or diagrams determined by the equation of Hazen-Williams. However, no data related to floppy polythene (PE) pipes with small diameter is available in the tables and diagrams mentioned. In this study, values relating to friction losses and pressures formed in 10, 20, ...
Low loss power splitter for antenna beam forming networks using probes in a waveguide
Dich, Mikael; Mortensen, Mette Dahl
1994-01-01
The design of a low loss one-to-four power splitter suitable for beam forming networks in antenna arrays is presented. The power splitter is constructed of a shorted waveguide in which five coaxial probes are inserted. Methods for the design of the power splitter are presented together with an experimental verification
Low loss power splitter for antenna beam forming networks using probes in a waveguide
DEFF Research Database (Denmark)
Dich, Mikael; Mortensen, Mette Dahl
1994-01-01
The design of a low loss one-to-four power splitter suitable for beam forming networks in antenna arrays is presented. The power splitter is constructed of a shorted waveguide in which five coaxial probes are inserted. Methods for the design of the power splitter are presented together...
Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei
2015-01-01
Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915measuredsamples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rateand heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08. PMID:26624613
Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei
2015-01-01
Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915 measured samples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rate and heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08.
Liu, Zhijian; Li, Hao; Tang, Xindong; Zhang, Xinyu; Lin, Fan; Cheng, Kewei
2016-01-01
Heat collection rate and heat loss coefficient are crucial indicators for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, wasting too much time and manpower. To address this problem, we previously used artificial neural networks and support vector machine to develop precise knowledge-based models for predicting the heat collection rates and heat loss coefficients of water-in-glass evacuated tube solar water heaters, setting the properties measured by "portable test instruments" as the independent variables. A robust software for determination was also developed. However, in previous results, the prediction accuracy of heat loss coefficients can still be improved compared to those of heat collection rates. Also, in practical applications, even a small reduction in root mean square errors (RMSEs) can sometimes significantly improve the evaluation and business processes. As a further study, in this short report, we show that using a novel and fast machine learning algorithm-extreme learning machine can generate better predicted results for heat loss coefficient, which reduces the average RMSEs to 0.67 in testing.
Allen, Paul D; Eddins, David A
2010-06-01
Many reports have documented age-by-frequency increases in average auditory thresholds in various human populations. Despite this, the prevalence of different patterns of hearing loss in presbycusis remains uncertain. We examined 'presbycusis phenotypes' in a database of 960 subjects (552 female, 408 male, 18-92 years) that each had 30 measures of peripheral hearing sensitivity: pure tone audiograms for left and right ears from 0.25 to 8 kHz and DPOAE for each ear with F(mean)=1-6.4 kHz. Surprisingly, the hearing phenotypes did not naturally separate into discrete classes of presbycusis. Principal component (PC) analysis revealed that two principal components account for 74% of the variance among the 30 measures of hearing. The two components represent the overall degree (PC1) and configuration of loss (Flat vs. Sloping; PC2) and the phenotypes form a continuum when plotted against them. A heuristic partitioning of this continuum produced classes of presbycusis that vary in their degree of Sloping or Flat hearing loss, suggesting that the previously reported sub-types of presbycusis arise from the categorical segregation of a continuous and heterogeneous distribution. Further, most phenotypes lie intermediate to the extremes of either Flat or Sloping loss, indicating that if audiometric configuration does predict presbycusis etiology, then a mixed origin is the most prevalent. Copyright 2010 Elsevier B.V. All rights reserved.
Comparison of the Friction-Loss Coefficient for the Gap of Two Contact Surfaces and a Crack
International Nuclear Information System (INIS)
Nam, Ho Yun; Choi, Byoung Hae; Kim, Jong Bum; Lee, Young Bum
2011-01-01
A leak-detection method has been developed by measuring the pressure variation between the inner and outer heat transfer tubes of a double-wall tube steam generator. An experiment was carried out to measure the leak rate in the gap between two surfaces pressed with a hydraulic press in order to simulate the phenomena, and a correlation was determined for the leak rate in a micro gap. However, in the correlation, the gap width and friction coefficient were coupled with the surface roughness, which affects the two parameters. The two parameters were separated using a surface-contact model to develop a correlation for the friction coefficient. The correlation was compared with the existing correlations used for crack analysis. Although the applied ranges of Reynolds numbers were different, the developed correlation for Reynolds numbers of 0.1.0.35 showed similar tendencies to existing correlations used for higher Reynolds numbers
Consideration of the loss of activity in the soil for large transfer coefficients in the food chain
International Nuclear Information System (INIS)
Brenk, H.D.; Vogt, K.J.
1978-01-01
The studies have shown that in the case of large transfer coefficients there will result a considerable overestimation of the ingestion dose if nonradioactive depletion effects are neglected. This overestimation may, depending on nuclide, vegetation and transfer coefficient, amount to two orders of magnitude. There will result e.g. for the bone exposure of a grown-up person, caused by 90 Sr taken up by the consumption of root vegetables, a dose overestimation up to a factor of 50. For the dose to the kidneys of adults by 137 Cs through consumption of beef there will result an overestimation by a factor of up to 60. And for 129 I there will be obtained an infant thyroid dose from the pasture-cow-milk pathway being too large by a factor of up to 100. In order to be able to cover these cases by a sufficiently generalized formalism, too, it appears necessary therefore to modify or extend the 'Allgemeine Berechnungsgrundlagen' (German reg. guide for evaluating the exposure from environmental contamination) in the manner proposed in the paper. (orig./HP) 891 HP/orig.- 892 MB [de
Directory of Open Access Journals (Sweden)
I. V. Klenina
2007-12-01
Full Text Available Thiol-disulfide coefficient (TDC and its different modifications in model in vivo were studied. Introduction of the liposome forms of cluster rhenium compounds with organic ligands (CROL leads to both TDC increasing and to the constancy of the TDC. Thus, CROLs aren’t toxic agents and some compounds could mobilize organisms’ thiol defence system. Liposome form of cis-platin leads to the TDC decreasing. Important CROL capacities for its future medical treatment practice were shown.
International Nuclear Information System (INIS)
Meng Xianghua; Tian Bo; Yao Zhenzhi; Feng Qian; Gao Yitian
2009-01-01
In this paper, the investigation is focused on a (3+1)-dimensional variable-coefficient Kadomtsev-Petviashvili (vcKP) equation, which can describe the realistic nonlinear phenomena in the fluid dynamics and plasma in three spatial dimensions. In order to study the integrability property of such an equation, the Painleve analysis is performed on it. And then, based on the truncated Painleve expansion, the bilinear form of the (3+1)-dimensional vcKP equation is obtained under certain coefficients constraint, and its solution in the Wronskian determinant form is constructed and verified by virtue of the Wronskian technique. Besides the Wronskian determinant solution, it is shown that the (3+1)-dimensional vcKP equation also possesses a solution in the form of the Grammian determinant. (general)
Zhang, Yongyong; Gao, Yang; Yu, Qiang
2017-09-01
Agricultural nitrogen loss becomes an increasingly important source of water quality deterioration and eutrophication, even threatens water safety for humanity. Nitrogen dynamic mechanism is still too complicated to be well captured at watershed scale due to its multiple existence forms and instability, disturbance of agricultural management practices. Stereoscopic agriculture is a novel agricultural planting pattern to efficiently use local natural resources (e.g., water, land, sunshine, heat and fertilizer). It is widely promoted as a high yield system and can obtain considerable economic benefits, particularly in China. However, its environmental quality implication is not clear. In our study, Qianyanzhou station is famous for its stereoscopic agriculture pattern of Southern China, and an experimental watershed was selected as our study area. Regional characteristics of runoff and nitrogen losses were simulated by an integrated water system model (HEQM) with multi-objective calibration, and multiple agriculture practices were assessed to find the effective approach for the reduction of diffuse nitrogen losses. Results showed that daily variations of runoff and nitrogen forms were well reproduced throughout watershed, i.e., satisfactory performances for ammonium and nitrate nitrogen (NH4-N and NO3-N) loads, good performances for runoff and organic nitrogen (ON) load, and very good performance for total nitrogen (TN) load. The average loss coefficient was 62.74 kg/ha for NH4-N, 0.98 kg/ha for NO3-N, 0.0004 kg/ha for ON and 63.80 kg/ha for TN. The dominating form of nitrogen losses was NH4-N due to the applied fertilizers, and the most dramatic zones aggregated in the middle and downstream regions covered by paddy and orange orchard. In order to control diffuse nitrogen losses, the most effective practices for Qianyanzhou stereoscopic agriculture pattern were to reduce farmland planting scale in the valley by afforestation, particularly for orchard in the
Wu, Lei; Gao, Jian-en; Ma, Xiao-yi; Li, Dan
2015-07-01
Chinese Loess Plateau is considered as one of the most serious soil loss regions in the world, its annual sediment output accounts for 90 % of the total sediment loads of the Yellow River, and most of the Loess Plateau has a very typical characteristic of "soil and water flow together", and water flow in this area performs with a high sand content. Serious soil loss results in nitrogen and phosphorus loss of soil. Special processes of water and soil in the Loess Plateau lead to the loss mechanisms of water, sediment, nitrogen, and phosphorus are different from each other, which are greatly different from other areas of China. In this study, the modified export coefficient method considering the rainfall erosivity factor was proposed to simulate and evaluate non-point source (NPS) nitrogen and phosphorus loss load caused by soil and water loss in the Yanhe River basin of the hilly and gully area, Loess Plateau. The results indicate that (1) compared with the traditional export coefficient method, annual differences of NPS total nitrogen (TN) and total phosphorus (TP) load after considering the rainfall erosivity factor are obvious; it is more in line with the general law of NPS pollution formation in a watershed, and it can reflect the annual variability of NPS pollution more accurately. (2) Under the traditional and modified conditions, annual changes of NPS TN and TP load in four counties (districts) took on the similar trends from 1999 to 2008; the load emission intensity not only is closely related to rainfall intensity but also to the regional distribution of land use and other pollution sources. (3) The output structure, source composition, and contribution rate of NPS pollution load under the modified method are basically the same with the traditional method. The average output structure of TN from land use and rural life is about 66.5 and 17.1 %, the TP is about 53.8 and 32.7 %; the maximum source composition of TN (59 %) is farmland; the maximum source
Energy Technology Data Exchange (ETDEWEB)
Shin, Chang-Hwan, E-mail: shinch@kaeri.re.kr; Park, Ju-Yong, E-mail: juyong@kaeri.re.kr; In, Wang-Kee, E-mail: wkin@kaeri.re.kr
2013-12-15
Highlights: • A lower end plug with side flow holes is suggested to provide alternative flow paths of the inner channel. • The inlet loss coefficient of the lower end plug is estimated from the experiment. • The flow rate through the side holes is estimated in a complete entrance blockage of inner channel. • The consequence in the reactor core condition is evaluated with a subchannel analysis code. - Abstract: Dual-cooled annular nuclear fuel for a pressurized water reactor (PWR) has been introduced for a significant increase in reactor power. KAERI has been developing a dual-cooled annular fuel for a power uprate of 20% in an optimized PWR in Korea, the OPR1000. This annular fuel can help decrease the fuel temperature substantially relative to conventional cylindrical fuel at a power uprate. Annular fuel has dual flow channels around itself; however, the inner flow channel has a weakness in that it is isolated unlike the outer flow channel, which is open to other neighbouring outer channels for a coolant exchange in the reactor core. If the entrance of the inner channel is, as a hypothetical event, completely blocked by debris, the inner channel will then experience a rapid increase in coolant temperature such that a departure from nucleate boiling (DNB) may occur. Therefore, a remedy to avoid such a postulated accident is indispensable for the safety of annular fuel. A lower end plug with side flow holes was suggested to provide alternative flow paths in addition to the central entrance of the inner channel. In this paper, the inlet loss coefficient of the lower end plug and the flow rate through the side holes were estimated from the experimental results even in a complete entrance blockage of the inner channel. An optimization for the side hole was also performed, and the results are applied to a subchannel analysis to evaluate the consequence in the reactor core condition.
International Nuclear Information System (INIS)
Saveliev, M.V.
1983-01-01
A method is proposed for classification of exactly and completely integrable embeddings of two dimensional manifoilds into Riemann or non-Riemann enveloping space, which are based on the algebraic approach to the integration of nonlinear dynamical systems.Here the grading conditions and spectral structure of the Lax-pair operators taking the values in a graded Lie algebra that pick out the integrable class of nonlinear systems are formulated 1n terms of a structure of the 3-d fundamental form tensors. Corresponding to every embedding of three-dimensional subalgebra sb(2) into a simple finite-dimensional (infinite-dimensional of finite growth) Lie algebra L is a definite class of exactly (completely) integrable embeddings of two dimensional manifold into the corresponding enveloping space supplied with the structure of L
Energy Technology Data Exchange (ETDEWEB)
Prasad, T.E. Vittal [Properties Group, Chemical Engineering Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007 (India); Venkanna, N. [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Kumar, Y. Naveen [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Ashok, K. [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Sirisha, N.M. [Swamy Ramanandateertha Institute of Science and Technology, Hyderabad 508 004 (India); Prasad, D.H.L. [Properties Group, Chemical Engineering Laboratory, Indian Institute of Chemical Technology, Hyderabad 500 007 (India)]. E-mail: dasika@iict.res.in
2007-07-15
Bubble point temperatures at 95.23 kPa, over the entire composition range are measured for the binary mixtures formed by p-cresol with 1,2-dichloroethane, 1,1,2,2-tetrachloroethane trichloroethylene, tetrachloroethylene, and o- , m- , and p-xylenes, making use of a Swietoslawski-type ebulliometer. Liquid phase mole fraction (x {sub 1}) versus bubble point temperature (T) measurements are found to be well represented by the Wilson model. The optimum Wilson parameters are used to calculate the vapor phase composition, activity coefficients, and excess Gibbs free energy. The results are discussed.
International Nuclear Information System (INIS)
Chantler, C.T.
2000-01-01
Full text: Reliable knowledge of the complex X-ray form factor and the photoelectric attenuation coefficient is required for crystallography, medical diagnosis, refractive index studies and XAFS. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 keV to 3 keV X-ray energies. This work derives new theoretical results in near-edge soft X-ray regions and improves upon the theoretical uncertainty in these regions by a factor of 10. This work was also reported in J.Phys.Chem.Ref.Data (2000)
Characterization of low-temperature microwave loss of thin aluminum oxide formed by plasma oxidation
Energy Technology Data Exchange (ETDEWEB)
Deng, Chunqing, E-mail: cdeng@uwaterloo.ca; Otto, M.; Lupascu, A., E-mail: alupascu@uwaterloo.ca [Institute for Quantum Computing, Department of Physics and Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
2014-01-27
We report on the characterization of microwave loss of thin aluminum oxide films at low temperatures using superconducting lumped resonators. The oxide films are fabricated using plasma oxidation of aluminum and have a thickness of 5 nm. We measure the dielectric loss versus microwave power for resonators with frequencies in the GHz range at temperatures from 54 to 303 mK. The power and temperature dependence of the loss are consistent with the tunneling two-level system theory. These results are relevant to understanding decoherence in superconducting quantum devices. The obtained oxide films are thin and robust, making them suitable for capacitors in compact microwave resonators.
Directory of Open Access Journals (Sweden)
Soltis Pamela S
2009-06-01
Full Text Available Abstract Background Polyploidy (whole-genome duplication is an important speciation mechanism, particularly in plants. Gene loss, silencing, and the formation of novel gene complexes are some of the consequences that the new polyploid genome may experience. Despite the recurrent nature of polyploidy, little is known about the genomic outcome of independent polyploidization events. Here, we analyze the fate of genes duplicated by polyploidy (homoeologs in multiple individuals from ten natural populations of Tragopogon miscellus (Asteraceae, all of which formed independently from T. dubius and T. pratensis less than 80 years ago. Results Of the 13 loci analyzed in 84 T. miscellus individuals, 11 showed loss of at least one parental homoeolog in the young allopolyploids. Two loci were retained in duplicate for all polyploid individuals included in this study. Nearly half (48% of the individuals examined lost a homoeolog of at least one locus, with several individuals showing loss at more than one locus. Patterns of loss were stochastic among individuals from the independently formed populations, except that the T. dubius copy was lost twice as often as T. pratensis. Conclusion This study represents the most extensive survey of the fate of genes duplicated by allopolyploidy in individuals from natural populations. Our results indicate that the road to genome downsizing and ultimate genetic diploidization may occur quickly through homoeolog loss, but with some genes consistently maintained as duplicates. Other genes consistently show evidence of homoeolog loss, suggesting repetitive aspects to polyploid genome evolution.
Soil loss and run-off measurements form natural veld with a rainfall ...
African Journals Online (AJOL)
off from natural veld in different successional stages and different slopes. Run-off as much as 94,34% of the applied volume of water and soil loss of 5,74t/ha were recorded from a pioneer grass cover with a 2,42% slope. Of all the variables ...
International Nuclear Information System (INIS)
Perroud, P.; De La Harpe, A.; Rebiere, J.
1960-12-01
Two stainless steel tubes were used (with diameters of 5 and 10 mm, lengths 400 and 600 mm respectively), heated electrically (50 Hz). The mixture flows from top to bottom. The work was carried out mainly on mixtures of high concentration (x > 0.1), at pressures between 50 and 60 kg/cm 2 , flowing as a liquid film on the walls of the tube with droplets suspended in the central current of steam. By analysis of the heat transfer laws the exchange mechanisms were established, and the conditions under which the critical heat flux may be exceeded without danger of actual burnout were determined. In this way high output concentrations (x s > 0.9) may be obtained. An attempt has been made to find out to what extent existing correlation formulae can be used to account for the phenomena observed. It is shown that those dealing with exchange coefficients can only be applied in a first approximation in cases where exchange by convection is preponderant, and only below the critical flux. The formulae proposed by WAPD and CISE do not give a satisfactory estimation of the critical heat flux, and the essential reasons for this inadequacy are explained. Lastly, the Martinelli and Nelson method may be used to an approximation of 30 per cent for the calculation of charge losses. (author) [fr
Directory of Open Access Journals (Sweden)
Jorge Yunta
2018-02-01
Full Text Available Tires are a key sub-system of vehicles that have a big responsibility for comfort, fuel consumption and traffic safety. However, current tires are just passive rubber elements which do not contribute actively to improve the driving experience or vehicle safety. The lack of information from the tire during driving gives cause for developing an intelligent tire. Therefore, the aim of the intelligent tire is to monitor tire working conditions in real-time, providing useful information to other systems and becoming an active system. In this paper, tire tread deformation is measured to provide a strong experimental base with different experiments and test results by means of a tire fitted with sensors. Tests under different working conditions such as vertical load or slip angle have been carried out with an indoor tire test rig. The experimental data analysis shows the strong relation that exists between lateral force and the maximum tensile and compressive strain peaks when the tire is not working at the limit of grip. In the last section, an estimation system from experimental data has been developed and implemented in Simulink to show the potential of strain sensors for developing intelligent tire systems, obtaining as major results a signal to detect tire’s loss of grip and estimations of the lateral friction coefficient.
Yunta, Jorge; Garcia-Pozuelo, Daniel; Diaz, Vicente; Olatunbosun, Oluremi
2018-02-06
Tires are a key sub-system of vehicles that have a big responsibility for comfort, fuel consumption and traffic safety. However, current tires are just passive rubber elements which do not contribute actively to improve the driving experience or vehicle safety. The lack of information from the tire during driving gives cause for developing an intelligent tire. Therefore, the aim of the intelligent tire is to monitor tire working conditions in real-time, providing useful information to other systems and becoming an active system. In this paper, tire tread deformation is measured to provide a strong experimental base with different experiments and test results by means of a tire fitted with sensors. Tests under different working conditions such as vertical load or slip angle have been carried out with an indoor tire test rig. The experimental data analysis shows the strong relation that exists between lateral force and the maximum tensile and compressive strain peaks when the tire is not working at the limit of grip. In the last section, an estimation system from experimental data has been developed and implemented in Simulink to show the potential of strain sensors for developing intelligent tire systems, obtaining as major results a signal to detect tire's loss of grip and estimations of the lateral friction coefficient.
Directory of Open Access Journals (Sweden)
Soltis Pamela S
2010-02-01
Full Text Available Abstract Background Although polyploidy has long been recognized as a major force in the evolution of plants, most of what we know about the genetic consequences of polyploidy comes from the study of crops and model systems. Furthermore, although many polyploid species have formed repeatedly, patterns of genome evolution and gene expression are largely unknown for natural polyploid populations of independent origin. We therefore examined patterns of loss and expression in duplicate gene pairs (homeologs in multiple individuals from seven natural populations of independent origin of Tragopogon mirus (Asteraceae, an allopolyploid that formed repeatedly within the last 80 years from the diploids T. dubius and T. porrifolius. Results Using cDNA-AFLPs, we found differential band patterns that could be attributable to gene silencing, novel expression, and/or maternal/paternal effects between T. mirus and its diploid parents. Subsequent cleaved amplified polymorphic sequence (CAPS analyses of genomic DNA and cDNA revealed that 20 of the 30 genes identified through cDNA-AFLP analysis showed additivity, whereas nine of the 30 exhibited the loss of one parental homeolog in at least one individual. Homeolog loss (versus loss of a restriction site was confirmed via sequencing. The remaining gene (ADENINE-DNA GLYCOSYLASE showed ambiguous patterns in T. mirus because of polymorphism in the diploid parent T. dubius. Most (63.6% of the homeolog loss events were of the T. dubius parental copy. Two genes, NUCLEAR RIBOSOMAL DNA and GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE, showed differential expression of the parental homeologs, with the T. dubius copy silenced in some individuals of T. mirus. Conclusions Genomic and cDNA CAPS analyses indicated that plants representing multiple populations of this young natural allopolyploid have experienced frequent and preferential elimination of homeologous loci. Comparable analyses of synthetic F1 hybrids showed only
Richels, Corrin G.; Bobzien, Jonna L.; Schwartz, Kathryn S.; Raver, Sharon A.; Browning, Ellen L.; Hester, Peggy P.
2016-01-01
Structured input from both teachers and peers maximizes the opportunities for preschoolers to learn grammatical forms. The purpose of this pilot study was to evaluate the effectiveness of using a teacher and a peer with typical hearing and language skills to model grammatically correct verbal responses to action "wh-" questions…
Directory of Open Access Journals (Sweden)
Zhijian Liu
2015-08-01
Full Text Available The determinations of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, which also wastes too much time and manpower. To address this problem, we propose machine learning models including artificial neural networks (ANNs and support vector machines (SVM to predict the heat collection rate and heat loss coefficient without a direct determination. Parameters that can be easily obtained by “portable test instruments” were set as independent variables, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, final temperature and angle between tubes and ground, while the heat collection rate and heat loss coefficient determined by the detection device were set as dependent variables respectively. Nine hundred fifteen samples from in-service water-in-glass evacuated tube solar water heaters were used for training and testing the models. Results show that the multilayer feed-forward neural network (MLFN with 3 nodes is the best model for the prediction of heat collection rate and the general regression neural network (GRNN is the best model for the prediction of heat loss coefficient due to their low root mean square (RMS errors, short training times, and high prediction accuracies (under the tolerances of 30%, 20%, and 10%, respectively.
Whittaker, Carly; Yates, Nicola E; Powers, Stephen J; Misselbrook, Tom; Shield, Ian
2018-05-01
This study compares dry matter losses and quality changes during the storage of SRC willow as chips and as rods. A wood chip stack consisting of approximately 74 tonnes of fresh biomass, or 31 tonnes dry matter (DM) was built after harvesting in the spring. Three weeks later, four smaller stacks of rods with an average weight of 0.8 tonnes, or 0.4 tonnes DM were built. During the course of the experiment temperature recorders placed in the stacks found that the wood chip pile reached 60 °C within 10 days of construction, but the piles of rods remained mostly at ambient temperatures. Dry matter losses were calculated by using pre-weighed independent samples within the stacks and by weighing the whole stack before and after storage. After 6 months the wood chip stack showed a DM loss of between 19.8 and 22.6%, and mean losses of 23.1% were measured from the 17 independent samples. In comparison, the rod stacks showed an average stack DM loss of between 0 and 9%, and between 1.4% and 10.6% loss from the independent samples. Analysis of the stored material suggests that storing willow in small piles of rods produces a higher quality fuel in terms of lower moisture and ash content; however, it has a higher fine content compared to storage in chip form. Therefore, according to the two storage methods tested here, there may be a compromise between maximising the net dry matter yield from SRC willow and the final fine content of the fuel.
Directory of Open Access Journals (Sweden)
Hannah Twarkowski
2016-09-01
Full Text Available Neuromodulation by means of the catecholaminergic system is a key component of motivation-driven learning and behaviorally modulated hippocampal synaptic plasticity. In particular, dopamine acting on D1/D5 receptors and noradrenaline acting on beta-adrenergic receptors exert a very potent regulation of forms of hippocampal synaptic plasticity that last for very long-periods of time (>24h, and occur in conjunction with novel spatial learning. Antagonism of these receptors not only prevents long-term potentiation (LTP and long-term depression (LTD, but prevents the memory of the spatial event that, under normal circumstances, leads to the perpetuation of these plasticity forms. Spatial learning behavior that normally comes easily to rats, such as object-place learning and spatial reference learning, becomes increasingly impaired with aging. Middle-aged animals display aging-related deficits of specific, but not all, components of spatial learning, and one possibility is that this initial manifestation of decrements in learning ability that become manifest in middle-age relate to changes in motivation, attention and/or the regulation by neuromodulatory systems of these behavioral states.Here, we compared the regulation by dopaminergic D1/D5 and beta-adrenergic receptors of persistent LTP in young (2-4 month old and middle-aged (8-14 month old rats. We observed in young rats, that weak potentiation that typically lasts for ca. 2h could be strengthened into persistent (>24h LTP by pharmacological activation of either D1/D5 or beta-adrenergic receptors. By contrast, no such facilitation occurred in middle-aged rats. This difference was not related to an ostensible learning deficit: a facilitation of weak potentiation into LTP by spatial learning was possible both in young and middle-aged rats. It was also not directly linked to deficits in LTP: strong afferent stimulation resulted in equivalent LTP in both age groups. We postulate that this change in
Social biases modulate the loss of redundant forms in the cultural evolution of language.
Roberts, Gareth; Fedzechkina, Maryia
2018-02-01
According to the competitive exclusion principle (Gause, 1934), competition for the same niche must eventually lead one competitor to extinction or the occupation of a new niche. This principle applies in both biology and the cultural evolution of language, where different words and structures compete for the same function or meaning (Aronoff, 2016). Across languages, for example, word order trades off with case marking as a means of indicating who did what to whom in a sentence. Previous experimental work has shed light on how such trade-offs come about as languages adapt to human biases through learning and production, with biases becoming amplified through iterated learning over generations. At the same time, a large body of work has documented the impact of social biases on language change. However, little work has investigated how social biases interact with learning and production biases. In particular, the social dimension of language may provide alternative niches for otherwise redundant forms, preventing or slowing their extinction. We tested this hypothesis in an iterated-learning experiment in which participants were exposed to a language with two dialects, both of which had fixed word order, but differed in whether they employed case markers. In one condition, we biased participants socially towards speakers of the dialect that employed case; in other conditions we provided no bias, or biased participants for or against the dialect without case. As expected under our hypothesis, the use of case markers declined over time in all conditions, but the social bias in favor of case-dialect speakers slowed the decline. Copyright © 2017 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Sasaki, H.; Yoshinaga, H.; Kura, S.
1986-01-01
The relationship between binucleate cell formation and the loss of colony-forming ability was examined in several cultured mammalian cell lines irradiated with X rays. The maximum fraction of binucleate cells after X irradiation increased dose-dependently within the range in which reproductive cell death might predominate over interphase cell death. When the logarithm of percentage survival was plotted against the percentage binucleate cells, a similar correlation was found for all cell lines tested, with the exception of mouse leukemia L5178Y cells, the most radiosensitive cells used. These observations suggest that the fraction of binucleate cells in the cell population can serve as a measure of cellular radiation damage
International Nuclear Information System (INIS)
Avezova, N.R.; Avezov, R.R.
2015-01-01
The approximation formula is derived for calculating the normalized coefficient of thermal losses of flat solar collectors (FSCs) for heating heat-transfer fluid (HTF). These are used in hot water supply systems in the warmer part of the year, depending on the average working surface temperature of their radiation-absorbing thermal exchange panels (RATEPs) (t"-_w_s_r) and the ambient temperature (t_a_m_b) in their realistic variation range. (author)
International Nuclear Information System (INIS)
Bluemlein, Johannes; Klein, Sebastian; Kauers, Manuel; Schneider, Carsten
2009-02-01
Single scale quantities, as anomalous dimensions and hard scattering cross sections, in renormalizable Quantum Field Theories are found to obey difference equations of finite order in Mellin space. It is often easier to calculate fixed moments for these quantities compared to a direct attempt to derive them in terms of harmonic sums and their generalizations involving the Mellin parameter N. Starting from a sufficiently large number of given moments, we establish linear recurrence relations of lowest possible order with polynomial coefficients of usually high degree. Then these recurrence equations are solved in terms of d'Alembertian solutions where the involved nested sums are represented in optimal nested depth. Given this representation, it is then an easy task to express the result in terms of harmonic sums. In this process we compactify the result such that no algebraic relations occur among the sums involved. We demonstrate the method for the QCD unpolarized anomalous dimensions and massless Wilson coefficients to 3-loop order treating the contributions for individual color coefficients. For the most complicated subproblem 5114 moments were needed in order to produce a recurrence of order 35 whose coefficients have degrees up to 938. About four months of CPU time were needed to establish and solve the recurrences for the anomalous dimensions and Wilson coefficients on a 2 GHz machine requiring less than 10 GB of memory. No algorithm is known yet to provide such a high number of moments for 3-loop quantities. Yet the method presented shows that it is possible to establish and solve recurrences of rather large order and degree, occurring in physics problems, uniquely, fast and reliably with computer algebra. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Bluemlein, Johannes; Klein, Sebastian [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Kauers, Manuel; Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation
2009-02-15
Single scale quantities, as anomalous dimensions and hard scattering cross sections, in renormalizable Quantum Field Theories are found to obey difference equations of finite order in Mellin space. It is often easier to calculate fixed moments for these quantities compared to a direct attempt to derive them in terms of harmonic sums and their generalizations involving the Mellin parameter N. Starting from a sufficiently large number of given moments, we establish linear recurrence relations of lowest possible order with polynomial coefficients of usually high degree. Then these recurrence equations are solved in terms of d'Alembertian solutions where the involved nested sums are represented in optimal nested depth. Given this representation, it is then an easy task to express the result in terms of harmonic sums. In this process we compactify the result such that no algebraic relations occur among the sums involved. We demonstrate the method for the QCD unpolarized anomalous dimensions and massless Wilson coefficients to 3-loop order treating the contributions for individual color coefficients. For the most complicated subproblem 5114 moments were needed in order to produce a recurrence of order 35 whose coefficients have degrees up to 938. About four months of CPU time were needed to establish and solve the recurrences for the anomalous dimensions and Wilson coefficients on a 2 GHz machine requiring less than 10 GB of memory. No algorithm is known yet to provide such a high number of moments for 3-loop quantities. Yet the method presented shows that it is possible to establish and solve recurrences of rather large order and degree, occurring in physics problems, uniquely, fast and reliably with computer algebra. (orig.)
Pawlak, Mariusz; Ben-Asher, Anael; Moiseyev, Nimrod
2018-01-09
We present a simple expression and its derivation for reaction rate coefficients for cold anisotropic collision experiments based on adiabatic variational theory and time-independent non-Hermitian scattering theory. We demonstrate that only the eigenenergies of the resulting one-dimensional Schrödinger equation for different complex adiabats are required. The expression is applied to calculate the Penning ionization rate coefficients of an excited metastable helium atom with molecular hydrogen in an energy range spanning from hundreds of kelvins down to the millikelvin regime. Except for trivial quantities like the masses of the nuclei and the bond length of the diatomic molecule participating in the collision, one needs as input data only the complex potential energy surface (CPES). In calculations, we used recently obtained ab initio CPES by D. Bhattacharya et al. ( J. Chem. Theory Comput. 2017 , 13 , 1682 - 1690 ) without fitting parameters. The results show good accord with current measurements ( Nat. Phys. 2017 , 13 , 35 - 38 ).
Nakajima, Miki; Stevenson, David J.
2018-04-01
The Earth's Moon is thought to have formed from a circumterrestrial disk generated by a giant impact between the proto-Earth and an impactor approximately 4.5 billion years ago. Since this impact was energetic, the disk would have been hot (4000-6000 K) and partially vaporized (20-100% by mass). This formation process is thought to be responsible for the geochemical observation that the Moon is depleted in volatiles (e.g., K and Na). To explain this volatile depletion, some studies suggest the Moon-forming disk was rich in hydrogen, which was dissociated from water, and it escaped from the disk as a hydrodynamic wind accompanying heavier volatiles (hydrodynamic escape). This model predicts that the Moon should be significantly depleted in water, but this appears to contradict some of the recently measured lunar water abundances and D/H ratios that suggest that the Moon is more water-rich than previously thought. Alternatively, the Moon could have retained its water if the upper parts (low pressure regions) of the disk were dominated by heavier species because hydrogen would have had to diffuse out from the heavy-element rich disk, and therefore the escape rate would have been limited by this slow diffusion process (diffusion-limited escape). To identify which escape the disk would have experienced and to quantify volatiles loss from the disk, we compute the thermal structure of the Moon-forming disk considering various bulk water abundances (100-1000 ppm) and mid-plane disk temperatures (2500-4000 K). Assuming that the disk consists of silicate (SiO2 or Mg2SiO4) and water and that the disk is in the chemical equilibrium, our calculations show that the upper parts of the Moon-forming disk are dominated by heavy atoms or molecules (SiO and O at Tmid > 2500- 2800 K and H2O at Tmid lost water and hydrogen would have been small compared to the initial abundance assumed. This result indicates that the giant impact hypothesis can be consistent with the water-rich Moon
Energy Technology Data Exchange (ETDEWEB)
Yang, Jin-Wei; Gao, Yi-Tian, E-mail: gaoyt163@163.com; Wang, Qi-Min; Su, Chuan-Qi; Feng, Yu-Jie; Yu, Xin
2016-01-15
In this paper, a fourth-order variable-coefficient nonlinear Schrödinger equation is studied, which might describe a one-dimensional continuum anisotropic Heisenberg ferromagnetic spin chain with the octuple–dipole interaction or an alpha helical protein with higher-order excitations and interactions under continuum approximation. With the aid of auxiliary function, we derive the bilinear forms and corresponding constraints on the variable coefficients. Via the symbolic computation, we obtain the Lax pair, infinitely many conservation laws, one-, two- and three-soliton solutions. We discuss the influence of the variable coefficients on the solitons. With different choices of the variable coefficients, we obtain the parabolic, cubic, and periodic solitons, respectively. We analyse the head-on and overtaking interactions between/among the two and three solitons. Interactions between a bound state and a single soliton are displayed with different choices of variable coefficients. We also derive the quasi-periodic formulae for the three cases of the bound states.
Czech Academy of Sciences Publication Activity Database
Kozmidis-Petrovic, A.; Šesták, Jaroslav
2012-01-01
Roč. 110, č. 2 (2012), 997-1004 ISSN 1388-6150 Institutional research plan: CEZ:AV0Z10100521 Keywords : glass transition * Hrubý criterion * glass -forming ability * DTA/DSC Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.982, year: 2012
Strain, Elisabeth M A; Thomson, Russell J; Micheli, Fiorenza; Mancuso, Francesco P; Airoldi, Laura
2014-11-01
Identifying the type and strength of interactions between local anthropogenic and other stressors can help to set achievable management targets for degraded marine ecosystems and support their resilience by identifying local actions. We undertook a meta-analysis, using data from 118 studies to test the hypothesis that ongoing global declines in the dominant habitat along temperate rocky coastlines, forests of canopy-forming algae and/or their replacement by mat-forming algae are driven by the nonadditive interactions between local anthropogenic stressors that can be addressed through management actions (fishing, heavy metal pollution, nutrient enrichment and high sediment loads) and other stressors (presence of competitors or grazers, removal of canopy algae, limiting or excessive light, low or high salinity, increasing temperature, high wave exposure and high UV or CO2 ), not as easily amenable to management actions. In general, the cumulative effects of local anthropogenic and other stressors had negative effects on the growth and survival of canopy-forming algae. Conversely, the growth or survival of mat-forming algae was either unaffected or significantly enhanced by the same pairs of stressors. Contrary to our predictions, the majority of interactions between stressors were additive. There were however synergistic interactions between nutrient enrichment and heavy metals, the presence of competitors, low light and increasing temperature, leading to amplified negative effects on canopy-forming algae. There were also synergistic interactions between nutrient enrichment and increasing CO2 and temperature leading to amplified positive effects on mat-forming algae. Our review of the current literature shows that management of nutrient levels, rather than fishing, heavy metal pollution or high sediment loads, would provide the greatest opportunity for preventing the shift from canopy to mat-forming algae, particularly in enclosed bays or estuaries because of the
International Nuclear Information System (INIS)
Yan Hui; Chen Guanghua; Kwok, R.W.M.
1998-01-01
SiC buried layers were synthesized by a metal vapor vacuum arc ion source, with C + ions implanted into crystalline Si substrates. According to X-ray photoelectron spectroscopy, the characteristic electron energy loss spectra of the SiC buried layers were studied. It was found that the characteristic electron energy loss spectra depend on the profiles of the carbon content, and correlate well with the order of the buried layers
International Nuclear Information System (INIS)
Jonge, Martin D. de; Tran, Chanh Q.; Chantler, Christopher T.; Barnea, Zwi; Dhal, Bipin B.; Cookson, David J.; Lee, Wah-Keat; Mashayekhi, Ali
2005-01-01
We use the x-ray extended-range technique (XERT) [Chantler et al., Phys. Rev. A 64, 062506 (2001)] to measure the mass attenuation coefficients of molybdenum in the x-ray energy range of 13.5-41.5 keV to 0.02-0.15 % accuracy. Measurements made over an extended range of the measurement parameter space are critically examined to identify, quantify, and correct where necessary a number of experimental systematic errors. These results represent the most extensive experimental data set for molybdenum and include absolute mass attenuation coefficients in the regions of the x-ray absorption fine structure (XAFS) and x-ray-absorption near-edge structure (XANES). The imaginary component of the atomic form-factor f 2 is derived from the photoelectric absorption after subtracting calculated Rayleigh and Compton scattering cross sections from the total attenuation. Comparison of the result with tabulations of calculated photoelectric absorption coefficients indicates that differences of 1-15 % persist between the calculated and observed values
Energy Technology Data Exchange (ETDEWEB)
Boehm, Benny [Technical Univ. of Denmark, Dept. of Energy Engineering (Denmark)
1996-11-01
A comparison of different methods for in-situ determination of heat losses has been carried out on a 273 mm transmission line in Copenhagen. Instrumentation includes temperature sensors, heat flux meters and an infrared camera. The methods differ with regard to time consumption and costs of applying the specific method, demand on accuracy of temperature measurements, sensitivity to computational parameters, e.g. the thermal conductivity of the soil, response to transients in water temperature and the ground, and steady state assumptions in the model used in the interpretation of the measurements. Several of the applied methods work well. (au)
Energy coefficients for a propeller series
DEFF Research Database (Denmark)
Olsen, Anders Smærup
2004-01-01
The efficiency for a propeller is calculated by energy coefficients. These coefficients are related to four types of losses, i.e. the axial, the rotational, the frictional, and the finite blade number loss, and one gain, i.e. the axial gain. The energy coefficients are derived by use...... of the potential theory with the propeller modelled as an actuator disk. The efficiency based on the energy coefficients is calculated for a propeller series. The results show a good agreement between the efficiency based on the energy coefficients and the efficiency obtained by a vortex-lattice method....
Energy Technology Data Exchange (ETDEWEB)
Riis, B.J.; Christiansen, C.
1987-02-01
Calcium metabolism was examined in 133 healthy postmenopausal women every three months during two years of treatment with oral or percutaneous 17..beta..-estradiol combined with different doses of calcium supplementation and/or different gestagens. Bone mineral content measured in the forearm (single photon absorptiometry), in the spine and in the total skeleton (dual photon absorptiometry) was unchanged in all estrogen-treated groups during the two years of treatment, and the responses in the groups with and without calcium supplementation and with different gestagens were not significantly different. Furthermore, the responses were independent of route of administration of the estrogen. Biochemical indices of bone turnover (serum alkaline phosphatase and fasting urinary hydroxyproline/creatinine) decreased highly significantly during estrogen treatment (p<0.001) independent of route of administration of the estrogen, of calcium supplementation, and of gestagen agent. We conclude that estrogen treatment independently of route of administration, prevents postmenopausal bone loss. The gestagen agents used here do not affect calcium metabolism, and calcium supplementation has no additive effect to estrogen therapy.
Pressure drop coefficient of laminar Newtonian flow in axisymmetric diffusers
International Nuclear Information System (INIS)
Rosa, S.; Pinho, F.T.
2006-01-01
The laminar flow of Newtonian fluids in axisymmetric diffusers has been numerically investigated to evaluate the pressure-loss coefficient as a function of Reynolds number, diffusion angle and expansion ratio. The numerical simulations were carried out with a finite-volume based code using non-orthogonal collocated grids and second order accurate differencing schemes to discretize all terms of the transport equations. The calculations were carried out for Reynolds numbers between 2 and 200, diffusion angles from 0 deg. to 90 deg. and expansion ratios of 1.5 and 2 and the data are presented in tabular form and as correlations. A simplified 1D theoretical analysis helped explain the various contributions to the loss coefficient and its difference relative to the reversible pressure variation due to differences between the actual and fully developed friction losses, distortions of the velocity profiles and pressure non-uniformity upstream and downstream of the expansion section
Pressure drop coefficient of laminar Newtonian flow in axisymmetric diffusers
Energy Technology Data Exchange (ETDEWEB)
Rosa, S. [Escola Superior de Tecnologia e Gestao, Instituto Politecnico, Campus de Santa Apolonia, 5301-857 Braganca (Portugal)]. E-mail: srosa@ipb.pt; Pinho, F.T. [Centro de Estudos de Fenomenos de Transporte, DEM, Universidade do Minho, Campus de Azurem, 4800-058 Guimaraes (Portugal)]. E-mail: fpinho@fe.up.pt
2006-04-15
The laminar flow of Newtonian fluids in axisymmetric diffusers has been numerically investigated to evaluate the pressure-loss coefficient as a function of Reynolds number, diffusion angle and expansion ratio. The numerical simulations were carried out with a finite-volume based code using non-orthogonal collocated grids and second order accurate differencing schemes to discretize all terms of the transport equations. The calculations were carried out for Reynolds numbers between 2 and 200, diffusion angles from 0 deg. to 90 deg. and expansion ratios of 1.5 and 2 and the data are presented in tabular form and as correlations. A simplified 1D theoretical analysis helped explain the various contributions to the loss coefficient and its difference relative to the reversible pressure variation due to differences between the actual and fully developed friction losses, distortions of the velocity profiles and pressure non-uniformity upstream and downstream of the expansion section.
Energy Technology Data Exchange (ETDEWEB)
Perroud, P; De La Harpe, A; Rebiere, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires
1960-12-15
Two stainless steel tubes were used (with diameters of 5 and 10 mm, lengths 400 and 600 mm respectively), heated electrically (50 Hz). The mixture flows from top to bottom. The work was carried out mainly on mixtures of high concentration (x > 0.1), at pressures between 50 and 60 kg/cm{sup 2}, flowing as a liquid film on the walls of the tube with droplets suspended in the central current of steam. By analysis of the heat transfer laws the exchange mechanisms were established, and the conditions under which the critical heat flux may be exceeded without danger of actual burnout were determined. In this way high output concentrations (x{sub s} > 0.9) may be obtained. An attempt has been made to find out to what extent existing correlation formulae can be used to account for the phenomena observed. It is shown that those dealing with exchange coefficients can only be applied in a first approximation in cases where exchange by convection is preponderant, and only below the critical flux. The formulae proposed by WAPD and CISE do not give a satisfactory estimation of the critical heat flux, and the essential reasons for this inadequacy are explained. Lastly, the Martinelli and Nelson method may be used to an approximation of 30 per cent for the calculation of charge losses. (author) [French] On a utilise deux tubes en acier inox (avec des diametres de 5 et 10 mm, et des longueurs respectives 400 et 600 mm) chauffes electriquement (50 Hz). Le melange s'ecoule de haut en bas. Les etudes ont porte plus specialement sur des melanges de titres eleves (x > 0,1) a des pressions comprises entre 60 et 90 kg/cm{sup 2} dont l'ecoulement se fait avec film liquide annulaire et gouttelettes en suspension dans le coeur de vapeur. Par l'analyse des lois de transfert de chaleur, on a precise les mecanismes d'echanges et l'on a d'autre part determine dans quelles conditions le flux de chaleur critique peut etre depasse sans danger de 'burnout' proprement dit. On peut ainsi obtenir des
Martí, Ramon; Nascimento, Andrés; Colomer, Jaume; Lara, Mari C; López-Gallardo, Ester; Ruiz-Pesini, Eduardo; Montoya, Julio; Andreu, Antoni L; Briones, Paz; Pineda, Mercè
2010-08-01
Mitochondrial DNA (mtDNA) depletion syndrome (MDS) is a devastating disorder of infancy caused by a significant reduction of the number of copies of mitochondrial DNA in one or more tissues. We report a Spanish patient with the myopathic form of MDS, harboring two mutations in the thymidine kinase 2 gene (TK2): a previously reported deletion (p.K244del) and a novel nucleotide duplication in the exon 2, generating a frameshift and premature stop codon. Sensorineural hearing loss was a predominant symptom in the patient and a novel feature of MDS due to TK2 mutations. The patient survived up to the age of 8.5 y, which confirms that survival above the age of 5 y is not infrequent in patients with MDS due to TK2 deficiency.
Directory of Open Access Journals (Sweden)
Celso E. L. de Oliveira
2006-08-01
Full Text Available O Coeficiente Global de Perdas de Calor (U permite o equacionamento das necessidades térmicas de uma casa de vegetação climatizada. No presente trabalho, determinou-se esse coeficiente cujo referencial foi uma casa de vegetação localizada em Madri (Espanha, em que foram utilizadas medidas noturnas de temperatura do ar no interior, no exterior, bem como o consumo de energia para aquecimento. As comparações entre as técnicas de aquecimento utilizadas foram: solo radiante e aerotermos combinados com duas técnicas que visavam a promover melhor aproveitamento térmico, ou seja, a utilização de cobertura plástica formando dupla capa ou a utilização de túnel plástico. Os menores coeficientes foram conseguidos para a utilização de solo radiante com túnel e aerotermos com dupla capa com 7,19 W m-2 ºC-1 e 9,11 W m-2 ºC-1, respectivamente; o maior valor dentre os coeficientes nas condições estudadas foi 15,13 W m-2 ºC-1 ao considerar o uso de aerotermos sem utilização de plásticos. Conclui-se, portanto, que os resultados comprovam o melhor rendimento térmico para as técnicas ensaiadas.The Global Heat Loss Coefficient (U allows some answers about thermal requirements of climatic greenhouse. This trial determined this coefficient for a greenhouse in Madrid (Spain where night measurements of inside and outside air temperature as well as energy consumption to heat were used. Comparisons were accomplished among the used heating techniques as: radiant floor and heat fan combined with two techniques aiming to promote a better thermal which means the use of a plastic covering forming a double couple or the use of a plastic tunnel. The lowest coefficients for the use of radiant soil with tunnel and heat fan with double couple were respectively 7.19 W m-2 ºC-1 and 9.11 W m-2 ºC-1 and the largest value was 15.13 W m-2 ºC-1 for the heat fan use without plastics. Therefore, the results registered best thermal efficiency for the tested
Power coefficient anomaly in JOYO
Energy Technology Data Exchange (ETDEWEB)
Yamamoto, H
1980-12-15
Operation of the JOYO experimental fast reactor with the MK-I core has been divided into two phases: (1) 50 MWt power ascension and operation; and (2) 75 MWt power ascension and operation. The 50 MWt power-up tests were conducted in August 1978. In these tests, the measured reactivity loss due to power increases from 15 MWt to 50 MWt was 0.28% ..delta.. K/K, and agreed well with the predicted value of 0.27% ..delta.. K/K. The 75 MWt power ascension tests were conducted in July-August 1979. In the process of the first power increase above 50 MWt to 65 MWt conducted on July 11, 1979, an anomalously large negative power coefficient was observed. The value was about twice the power coefficient values measured in the tests below 50 MW. In order to reproduce the anomaly, the reactor power was decreased and again increased up to the maximum power of 65 MWt. However, the large negative power coefficient was not observed at this time. In the succeeding power increase from 65 MWt to 75 MWt, a similar anomalous power coefficient was again observed. This anomaly disappeared in the subsequent power ascensions to 75 MWt, and the magnitude of the power coefficient gradually decreased with power cycles above the 50 MWt level.
Samuels, Tina L; Yan, Justin C; Khampang, Pawjai; Dettmar, Peter W; MacKinnon, Alexander; Hong, Wenzhou; Johnston, Nikki; Papsin, Blake C; Chun, Robert H; McCormick, Michael E; Kerschner, Joseph E
2017-08-01
Persistent, viscous middle ear effusion in pediatric otitis media (OM) contributes to increased likelihood of anesthesia and surgery, conductive hearing loss, and subsequent developmental delays. Biomarkers of effusion viscosity and hearing loss have not yet been identified despite the potential that such markers hold for targeted therapy and screening. To investigate the association of gel-forming mucins and aquaporin 5 (AQP5) gene expression with inflammation, effusion viscosity, and hearing loss in pediatric OM with effusion (OME). Case-control study of 31 pediatric patients (aged 6 months to 12 years) with OME undergoing tympanostomy tube placement and control individuals (aged 1 to 10 years) undergoing surgery for cochlear implantation from February 1, 2013, through November 30, 2014. Those with 1 or more episodes of OM in the previous 12 months, immunologic abnormality, anatomical or physiologic ear defect, OM-associated syndrome (ie, Down syndrome, cleft palate), chronic mastoiditis, or history of cholesteatoma were excluded from the study. All patients with OME and 1 control were recruited from Children's Hospital of Wisconsin, Milwaukee. The remainder of the controls were recruited from Sick Kids Hospital in Toronto, Ontario, Canada. Two to 3 middle ear biopsy specimens, effusions, and preoperative audiometric data (obtained effusions was assayed using rheometry. Of the 31 study participants, 24 patients had OME (mean [SD] age, 50.4 [31.9] months; 15 [62.5%] male; 16 [66.7%] white) and 7 acted as controls (mean [SD] age, 32.6 [24.4] months; 2 [26.6%] male; 6 [85.7%] white). Mucins and AQP5 gene expression were significantly higher in patients with OME relative to controls (MUC2: ratio, 127.6 [95% CI, 33.7-482.7]; MUC5AC: ratio, 3748.8 [95% CI, 558.1-25 178.4]; MUC5B: ratio, 471.1 [95% CI, 130.7-1697.4]; AQP5: ratio, 2.4 [95% CI, 1.1-5.6]). A 2-fold increase in MUC5B correlated with increased hearing loss (air-bone gap: 7.45 dB [95% CI, 2.65-12.24 d
Directory of Open Access Journals (Sweden)
Claudete Regina Alcalde
1999-01-01
Full Text Available Os objetivos deste trabalho foram determinar a absorção aparente, estimar as perdas endógenas fecais e a absorção real do Mg e determinar a ingestão ad libitum da água de beber e a concentração de Mg no soro sangüíneo de caprinos da raças Anglonubiana (AN e Saanen (SN. Foram usados doze caprinos, seis de cada raça, com 19,8 kg PV médio. Dietas semipurificadas (baixo teor de Mg à base de quirera de arroz, glúten de milho e celulose foram suplementadas com MgO, para se obterem os níveis de 0,05 (sem supplementação 0,20 e 0,35% Mg (%MS. Os níveis de Mg influenciaram os coeficientes de absorção aparente de Mg e Ca, com valores médios de 57,8; 73,9; e 73,2% para Mg e 55,7; 39,6; e 49,5% para Ca, para dietas com níveis 0,05; 0,20; e 0,35% de Mg, respectivamente. Entretanto, para os coeficientes de absorção aparente de P, Na e K, não houve efeito de níveis de Mg na dieta. Os resultados de absorção real de Mg apresentaram interação de níveis de Mg e raças. A média para raça NA, no nível 0,05% Mg, foi de 61,0% e para os níveis 0,20 e 0,35% Mg, 77,2 e 73,2%, respectivamente. Entretanto, para a raça SN, as médias foram 73,3; 75,5; e 76,0%, para os mesmos níveis, sem diferenças. A digestibilidade de matéria seca, proteína bruta e extrato não-nitrogenado diminuiu com os níveis crescentes de Mg nas dietas. As excreções fecais (7,0; 20,8; e 34,4 mg/kg PV0,75.d e urinárias (3,9; 30,8; e 44,6 mg/kg PV0,75.d de Mg elevaram-se com o aumento dos níveis crescentes de Mg nas dietas. Houve, também, influência dos níveis de Mg dietético sobre as concentrações de Mg do soro sangüíneo (1,74; 2,23; e 2,80 mg/dL para níveis de 0,05; 0,20; e 0,35% de Mg, respectivamente.The objectives of this experiment were to determine the apparent absorption, to estimate the endogenous fecal losses and the true absorption of Mg and to determine the ad libitum drinking water ingestion and the Mg serum concentration for Anglonubian
Algebraic polynomials with random coefficients
Directory of Open Access Journals (Sweden)
K. Farahmand
2002-01-01
Full Text Available This paper provides an asymptotic value for the mathematical expected number of points of inflections of a random polynomial of the form a0(ω+a1(ω(n11/2x+a2(ω(n21/2x2+…an(ω(nn1/2xn when n is large. The coefficients {aj(w}j=0n, w∈Ω are assumed to be a sequence of independent normally distributed random variables with means zero and variance one, each defined on a fixed probability space (A,Ω,Pr. A special case of dependent coefficients is also studied.
Directory of Open Access Journals (Sweden)
Zhijie Niu
Full Text Available X-linked hearing impairment is the rarest form of genetic hearing loss (HL and represents only a minor fraction of all cases. The aim of this study was to investigate the cause of X-linked inherited sensorineural HL in a four-generation Chinese family. A novel duplication variant (c.217dupA, p.Ile73Asnfs*5 in SMPX was identified by whole-exome sequencing. The frameshift mutation predicted to result in the premature truncation of the SMPX protein was co-segregated with the HL phenotype and was absent in 295 normal controls. Subpopulation screening of the coding exons and flanking introns of SMPX was further performed for 338 Chinese patients with nonsydromic HL by Sanger sequencing, and another two potential causative substitutions (c.238C>A and c.55A>G in SMPX were identified in additional sporadic cases of congenital deafness. Collectively, this study is the first to report the role of SMPX in Chinese population and identify a novel frameshift mutation in SMPX that causes not only nonsyndromic late-onset progressive HL, but also congenital hearing impairment. Our findings extend the mutation and phenotypic spectrum of the SMPX gene.
DEFF Research Database (Denmark)
Karlsson, Kenneth; Næraa, Rikke
1997-01-01
Determination of heat loss coefficients for buildings in Denmark. The coefficient are determined for 15 building groups and 3 year intervals. They are based on the BBR-registre and assumptions of U-values(W/K*m2)and computed in a simple spreed sheet model.The results are used in the REVEILLE...
Transport Coefficients of Fluids
Eu, Byung Chan
2006-01-01
Until recently the formal statistical mechanical approach offered no practicable method for computing the transport coefficients of liquids, and so most practitioners had to resort to empirical fitting formulas. This has now changed, as demonstrated in this innovative monograph. The author presents and applies new methods based on statistical mechanics for calculating the transport coefficients of simple and complex liquids over wide ranges of density and temperature. These molecular theories enable the transport coefficients to be calculated in terms of equilibrium thermodynamic properties, and the results are shown to account satisfactorily for experimental observations, including even the non-Newtonian behavior of fluids far from equilibrium.
A new proposal for Lagrangian correlation coefficient
International Nuclear Information System (INIS)
Altinsoy, N.; Tugrul, A.B.
2002-01-01
The statistical description of dispersion in turbulent flow was first considered by Taylor (Proc. London Math. Soc. 20 (1921) 196) and the statistical properties of the field were determined by Lagrangian correlation coefficient R L (τ). Frenkiel (Adv. Appl. Mech. 3 (1953) 61) has proposed several simple forms for R L (τ). Some workers have investigated for a proper form of the Lagrangian correlation coefficient. In this work, a new proposal for the Lagrangian correlation coefficient is proposed and discussed. It can be written in general form with the one of the Frenkiel's (Adv. Appl. Mech. 3 (1953) 61) Lagrangian correlation coefficient. There is very satisfactory agreement between the new correlation and the experiment
International Electrotechnical Commission. Geneva
1972-01-01
Applies to d.c. machines and to a.c. synchronous and induction machines. The principles can be applied to other types of machines such as rotary converters, a.c. commutator motors and single-phase induction motors for which other methods of determining losses are used.
Evaluation of Rock Joint Coefficients
Audy, Ondřej; Ficker, Tomáš
2017-10-01
A computer method for evaluation of rock joint coefficients is described and several applications are presented. The method is based on two absolute numerical indicators that are formed by means of the Fourier replicas of rock joint profiles. The first indicator quantifies the vertical depth of profiles and the second indicator classifies wavy character of profiles. The absolute indicators have replaced the formerly used relative indicators that showed some artificial behavior in some cases. This contribution is focused on practical computations testing the functionality of the newly introduced indicators.
Harfmann, Katya L; Bechtel, Mark A
2015-03-01
Hair loss is a common cause of morbidity for many women. As a key member of the woman's health care team, the obstetrician/gynecologist may be the first person to evaluate the complaint of hair loss. Common types of nonscarring hair loss, including female pattern hair loss and telogen effluvium, may be diagnosed and managed by the obstetrician/gynecologist. A systematic approach to diagnosis and management of these common forms of hair loss is presented.
Diffusion coefficients of paracetamol in aqueous solutions
International Nuclear Information System (INIS)
Ribeiro, Ana C.F.; Barros, Marisa C.F.; Veríssimo, Luís M.P.; Santos, Cecilia I.A.V.; Cabral, Ana M.T.D.P.V.; Gaspar, Gualter D.; Esteso, Miguel A.
2012-01-01
Highlights: ► Mutual diffusion coefficients of paracetamol in aqueous dilute solutions. ► Influence of the thermodynamic factors on the variation of their mutual diffusion coefficients. ► Estimation of the mutual limiting diffusion coefficients of the molecular, D m 0 , and ionized forms, D ± 0 , of this drug. - Abstract: Binary mutual diffusion coefficients measured by the Taylor dispersion method, for aqueous solutions of paracetamol (PA) at concentrations from (0.001 to 0.050) mol·dm −3 at T = 298.15 K, are reported. From the Nernst–Hartley equation and our experimental results, the limiting diffusion coefficient of this drug and its thermodynamic factors are estimated, thereby contributing in this way to a better understanding of the structure of such systems and of their thermodynamic behaviour in aqueous solution at different concentrations.
Mohammed, Ahmed; Zeleke, Aklilu
2015-01-01
We introduce a class of second-order ordinary differential equations (ODEs) with variable coefficients whose closed-form solutions can be obtained by the same method used to solve ODEs with constant coefficients. General solutions for the homogeneous case are discussed.
Attenuation coefficients of soils
International Nuclear Information System (INIS)
Martini, E.; Naziry, M.J.
1989-01-01
As a prerequisite to the interpretation of gamma-spectrometric in situ measurements of activity concentrations of soil radionuclides the attenuation of 60 to 1332 keV gamma radiation by soil samples varying in water content and density has been investigated. A useful empirical equation could be set up to describe the dependence of the mass attenuation coefficient upon photon energy for soil with a mean water content of 10%, with the results comparing well with data in the literature. The mean density of soil in the GDR was estimated at 1.6 g/cm 3 . This value was used to derive the linear attenuation coefficients, their range of variation being 10%. 7 figs., 5 tabs. (author)
Transfer coefficients in elliptical tubes and plate fin heat exchangers
International Nuclear Information System (INIS)
Saboya, S.M.
1979-09-01
Mean transfer coefficients in elliptical tubes and plate fin heat exchangers were determined by application of heat and mass transfer analogy in conjunction with the naphthalene sublimation technique. The transfer coefficients are presented in a dimensionless form as functions of the Reynolds number. By using the least squares method analytical expressions for the transfer coefficients were determined with low scattering. (E.G.) [pt
Eskola, M; Bäckman, S; Möttönen, S; Kekomäki, R
2015-04-01
Total colony-forming cells from thawed cord blood units (CBUs) include megakaryocytic colony-forming units (CFU-Mks), which survive the freezing process. The aim of this study was to evaluate whether different megakaryocytic progenitors from unseparated CBUs survive the freezing process and a short-term liquid culture. Thawed samples of CBUs were cultured in liquid medium. During the cultures, serial samples were drawn to assess the growth of different megakaryocytic progenitors in a semisolid collagen medium with identical cytokines as in the liquid medium. Megakaryocytic cells were detected using immunohistochemistry and flow cytometry. In suspension culture, the megakaryocytic progenitors almost completely lost the ability to generate large (burst-forming unit-like, BFU-like) megakaryocytic colonies in semisolid cultures (large colonies, median count per chamber d0: 7.25 vs. d7: 1.5; P culture in suspension resulted in the decline of small colonies as well (d7: 16.0 vs. d14: 5.75; P = 0.0088). Total CFU-Mk count declined from 23.3 (range 12.5-34.0) at d0 to 7.25 (range 1.0-13.5) at d14 (P culture after a short suspension culture. Small CFU-Mks were observed throughout the cultures. It may be that the BFU-Mk colonies matured and acquired CFU-Mk behaviour. © 2014 International Society of Blood Transfusion.
The Truth About Ballistic Coefficients
Courtney, Michael; Courtney, Amy
2007-01-01
The ballistic coefficient of a bullet describes how it slows in flight due to air resistance. This article presents experimental determinations of ballistic coefficients showing that the majority of bullets tested have their previously published ballistic coefficients exaggerated from 5-25% by the bullet manufacturers. These exaggerated ballistic coefficients lead to inaccurate predictions of long range bullet drop, retained energy and wind drift.
Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too loud Difficulty following conversations when two or more people are talking ...
International Nuclear Information System (INIS)
Grote, S.J.; Joshi, G.P.; Revell, S.H.; Shaw, C.A.
1981-01-01
A preceding paper (Grote, Joshi, Revell and Shaw 1981) describe a method for the direct scrutiny of live cultured mammalian cells with a microscope, and reported that all diploid Syrian hamster cells (BHK 21 C13) of a sample given 1.4 Gy of 220 kV X-rays in G1 reached post-radiation mitosis without discernible abnormality, but then diverged in observed behaviour: descendant cells from some first mitoses continued to proliferate normally while cells from other first mitoses behaved abnormally and produced either slow-growth or stop-growth colonies. This paper completes the study of the same irradiated cell sample, and shows that these post-mitotic differences in clonogenic ability were related to acentric chromosome fragment losses at post-radiation mitosis, which were detected in live daughter-cell pairs as micronuclei. The proportion of live daughter-cell pairs scored as deficient was at least 80 per cent of the proportion of comparable fixed-and-stained mitoses with detected acentric fragments. (author)
Directory of Open Access Journals (Sweden)
Federico Tasca
Full Text Available The oxygen reduction reaction is one of the most important chemical processes in energy converting systems and living organisms. Mediator-less, direct electro-catalytic reduction of oxygen to water was achieved on spectrographite electrodes modified by physical adsorption of bilirubin oxidases from Myrothecium verrucaria. The existence of an alternative resting form of the enzyme is validated. The effect on the catalytic cycle of temperature, pH and the presence of halogens in the buffer was investigated. Previous results on the electrochemistry of bilirubin oxidase and on the impact of the presence of halogens are reviewed and reinterpreted.
Singularities of the transmission coefficient and anomalous scattering by a dielectric slab
Shestopalov, Yury
2018-03-01
We prove the existence and describe the distribution on the complex plane of the singularities, resonant states (RSs), of the transmission coefficient in the problem of the plane wave scattering by a parallel-plate dielectric slab in free space. It is shown that the transmission coefficient has isolated poles all with nonzero imaginary parts that form countable sets in the complex plane of the refraction index or permittivity of the slab with the only accumulation point at infinity. The transmission coefficient never vanishes and anomalous scattering, when its modulus exceeds unity, occurs at arbitrarily small loss of the dielectric filling the layer. These results are extended to the cases of scattering by arbitrary multi-layer parallel-plane media. Connections are established between RSs, spectral singularities, eigenvalues of the associated Sturm-Liouville problems on the line, and zeros of the corresponding Jost function.
International Nuclear Information System (INIS)
Schulz, E.
1988-01-01
In a pot experiment with Haplic Chernozem differing in total carbon content (Static Experiment at Lauchstaedt, 1983), studies were made into N supply from various forms of fertilizers and fertilizer N localization in the plant-soil system. In general, the percentage of fertilizer N in the total N amount taken up by maize was very high (60 to 90%). Both the variate difference method and the tracer technique identified almost equal percentages of fertilizer N in plants after application of pig urine and ammonium nitrate. However, mineralization of soil-borne N after application of sugar beet leaves was overestimated when using the variate difference method. There was no evidence of an additional mobilization of soil-borne N due to fertilization (priming effect). (author)
DEFF Research Database (Denmark)
Keiding, Tina Bering
2012-01-01
understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...
Regularity of the Interband Light Absorption Coefficient
Indian Academy of Sciences (India)
In this paper we consider the interband light absorption coefficient (ILAC), in a symmetric form, in the case of random operators on the -dimensional lattice. We show that the symmetrized version of ILAC is either continuous or has a component which has the same modulus of continuity as the density of states.
Drag coefficient Variability and Thermospheric models
Moe, Kenneth
Satellite drag coefficients depend upon a variety of factors: The shape of the satellite, its altitude, the eccentricity of its orbit, the temperature and mean molecular mass of the ambient atmosphere, and the time in the sunspot cycle. At altitudes where the mean free path of the atmospheric molecules is large compared to the dimensions of the satellite, the drag coefficients can be determined from the theory of free-molecule flow. The dependence on altitude is caused by the concentration of atomic oxygen which plays an important role by its ability to adsorb on the satellite surface and thereby affect the energy loss of molecules striking the surface. The eccentricity of the orbit determines the satellite velocity at perigee, and therefore the energy of the incident molecules relative to the energy of adsorption of atomic oxygen atoms on the surface. The temperature of the ambient atmosphere determines the extent to which the random thermal motion of the molecules influences the momentum transfer to the satellite. The time in the sunspot cycle affects the ambient temperature as well as the concentration of atomic oxygen at a particular altitude. Tables and graphs will be used to illustrate the variability of drag coefficients. Before there were any measurements of gas-surface interactions in orbit, Izakov and Cook independently made an excellent estimate that the drag coefficient of satellites of compact shape would be 2.2. That numerical value, independent of altitude, was used by Jacchia to construct his model from the early measurements of satellite drag. Consequently, there is an altitude dependent bias in the model. From the sparce orbital experiments that have been done, we know that the molecules which strike satellite surfaces rebound in a diffuse angular distribution with an energy loss given by the energy accommodation coefficient. As more evidence accumulates on the energy loss, more realistic drag coefficients are being calculated. These improved drag
On the Kendall Correlation Coefficient
Stepanov, Alexei
2015-01-01
In the present paper, we first discuss the Kendall rank correlation coefficient. In continuous case, we define the Kendall rank correlation coefficient in terms of the concomitants of order statistics, find the expected value of the Kendall rank correlation coefficient and show that the later is free of n. We also prove that in continuous case the Kendall correlation coefficient converges in probability to its expected value. We then propose to consider the expected value of the Kendall rank ...
... To receive Pregnancy email updates Enter email Submit Pregnancy loss Pregnancy loss is a harsh reality faced ... have successful pregnancies. Expand all | Collapse all Why pregnancy loss happens As many as 10 to 15 ...
Symmetry chains and adaptation coefficients
International Nuclear Information System (INIS)
Fritzer, H.P.; Gruber, B.
1985-01-01
Given a symmetry chain of physical significance it becomes necessary to obtain states which transform properly with respect to the symmetries of the chain. In this article we describe a method which permits us to calculate symmetry-adapted quantum states with relative ease. The coefficients for the symmetry-adapted linear combinations are obtained, in numerical form, in terms of the original states of the system and can thus be represented in the form of numerical tables. In addition, one also obtains automatically the matrix elements for the operators of the symmetry groups which are involved, and thus for any physical operator which can be expressed either as an element of the algebra or of the enveloping algebra. The method is well suited for computers once the physically relevant symmetry chain, or chains, have been defined. While the method to be described is generally applicable to any physical system for which semisimple Lie algebras play a role we choose here a familiar example in order to illustrate the method and to illuminate its simplicity. We choose the nuclear shell model for the case of two nucleons with orbital angular momentum l = 1. While the states of the entire shell transform like the smallest spin representation of SO(25) we restrict our attention to its subgroup SU(6) x SU(2)/sub T/. We determine the symmetry chains which lead to total angular momentum SU(2)/sub J/ and obtain the symmetry-adapted states for these chains
Quadrature formulas for Fourier coefficients
Bojanov, Borislav
2009-09-01
We consider quadrature formulas of high degree of precision for the computation of the Fourier coefficients in expansions of functions with respect to a system of orthogonal polynomials. In particular, we show the uniqueness of a multiple node formula for the Fourier-Tchebycheff coefficients given by Micchelli and Sharma and construct new Gaussian formulas for the Fourier coefficients of a function, based on the values of the function and its derivatives. © 2009 Elsevier B.V. All rights reserved.
Coefficient Alpha: A Reliability Coefficient for the 21st Century?
Yang, Yanyun; Green, Samuel B.
2011-01-01
Coefficient alpha is almost universally applied to assess reliability of scales in psychology. We argue that researchers should consider alternatives to coefficient alpha. Our preference is for structural equation modeling (SEM) estimates of reliability because they are informative and allow for an empirical evaluation of the assumptions…
Coefficient estimates of negative powers and inverse coefficients for ...
Indian Academy of Sciences (India)
and the inequality is sharp for the inverse of the Koebe function k(z) = z/(1 − z)2. An alternative approach to the inverse coefficient problem for functions in the class S has been investigated by Schaeffer and Spencer [27] and FitzGerald [6]. Although, the inverse coefficient problem for the class S has been completely solved ...
Measuring of heat transfer coefficient
DEFF Research Database (Denmark)
Henningsen, Poul; Lindegren, Maria
Subtask 3.4 Measuring of heat transfer coefficient Subtask 3.4.1 Design and setting up of tests to measure heat transfer coefficient Objective: Complementary testing methods together with the relevant experimental equipment are to be designed by the two partners involved in order to measure...... the heat transfer coefficient for a wide range of interface conditions in hot and warm forging processes. Subtask 3.4.2 Measurement of heat transfer coefficient The objective of subtask 3.4.2 is to determine heat transfer values for different interface conditions reflecting those typically operating in hot...
On the Connection Coefficients of the Chebyshev-Boubaker Polynomials
Directory of Open Access Journals (Sweden)
Paul Barry
2013-01-01
Full Text Available The Chebyshev-Boubaker polynomials are the orthogonal polynomials whose coefficient arrays are defined by ordinary Riordan arrays. Examples include the Chebyshev polynomials of the second kind and the Boubaker polynomials. We study the connection coefficients of this class of orthogonal polynomials, indicating how Riordan array techniques can lead to closed-form expressions for these connection coefficients as well as recurrence relations that define them.
Wavelet Correlation Coefficient of 'strongly correlated' financial time series
Razdan, Ashok
2003-01-01
In this paper we use wavelet concepts to show that correlation coefficient between two financial data's is not constant but varies with scale from high correlation value to strongly anti-correlation value This studies is important because correlation coefficient is used to quantify degree of independence between two variables. In econophysics correlation coefficient forms important input to evolve hierarchial tree and minimum spanning tree of financial data.
Sabine absorption coefficients to random incidence absorption coefficients
DEFF Research Database (Denmark)
Jeong, Cheol-Ho
2014-01-01
into random incidence absorption coefficients for porous absorbers are investigated. Two optimization-based conversion methods are suggested: the surface impedance estimation for locally reacting absorbers and the flow resistivity estimation for extendedly reacting absorbers. The suggested conversion methods...
International Nuclear Information System (INIS)
Strel'tsov, V.N.
1992-01-01
The physical sense of three forms of the relativity is discussed. The first - instant from - respects in fact the traditional approach based on the concept of instant distance. The normal form corresponds the radar formulation which is based on the light or retarded distances. The front form in the special case is characterized by 'observable' variables, and the known method of k-coefficient is its obvious expression. 16 refs
Probabilistic optimization of safety coefficients
International Nuclear Information System (INIS)
Marques, M.; Devictor, N.; Magistris, F. de
1999-01-01
This article describes a reliability-based method for the optimization of safety coefficients defined and used in design codes. The purpose of the optimization is to determine the partial safety coefficients which minimize an objective function for sets of components and loading situations covered by a design rule. This objective function is a sum of distances between the reliability of the components designed using the safety coefficients and a target reliability. The advantage of this method is shown on the examples of the reactor vessel, a vapour pipe and the safety injection circuit. (authors)
Quadrature formulas for Fourier coefficients
Bojanov, Borislav; Petrova, Guergana
2009-01-01
We consider quadrature formulas of high degree of precision for the computation of the Fourier coefficients in expansions of functions with respect to a system of orthogonal polynomials. In particular, we show the uniqueness of a multiple node
Diffusion coefficient for anomalous transport
International Nuclear Information System (INIS)
1986-01-01
A report on the progress towards the goal of estimating the diffusion coefficient for anomalous transport is given. The gyrokinetic theory is used to identify different time and length scale inherent to the characteristics of plasmas which exhibit anomalous transport
Fuel Temperature Coefficient of Reactivity
Energy Technology Data Exchange (ETDEWEB)
Loewe, W.E.
2001-07-31
A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.
Properties of Traffic Risk Coefficient
Tang, Tie-Qiao; Huang, Hai-Jun; Shang, Hua-Yan; Xue, Yu
2009-10-01
We use the model with the consideration of the traffic interruption probability (Physica A 387(2008)6845) to study the relationship between the traffic risk coefficient and the traffic interruption probability. The analytical and numerical results show that the traffic interruption probability will reduce the traffic risk coefficient and that the reduction is related to the density, which shows that this model can improve traffic security.
Net emission coefficient for CO–H2 thermal plasmas with the consideration of molecular systems
International Nuclear Information System (INIS)
Billoux, T.; Cressault, Y.; Gleizes, A.
2015-01-01
This paper deals with the calculation of net emission coefficients (NECs) for CO–H 2 thermal plasmas. This task required the elaboration of a complete spectroscopic database including atoms and molecules formed by carbon, oxygen and hydrogen elements. We have used a systematic line by line method to calculate all the main radiative contributions which are the atomic and molecular continua, the atomic lines and the molecular (diatomic and polyatomic) lines. The main diatomic electronic systems for CO–H 2 plasmas and the triatomic molecular bands were considered. We present some variations of the net emission coefficient versus temperature, for various pressures and for two relative proportions of the components. The role of the diatomic molecules is important at temperatures lower than 5000 K whereas the net emission coefficient presents an unusual peak at temperature around 1000 K, due to the presence of the CO 2 molecule presenting a strong infrared radiation. Finally, the results show that the NEC slightly depends on the relative proportion of CO and H 2 . - highlights: • We calculate radiative losses from CO–H 2 thermal plasmas. • We use the up-to-date atomic and molecular databases. • The influence of CO 2 molecule is very important at low temperature. • The relative maximum of the net emission coefficient at low temperature is unusual
DEFF Research Database (Denmark)
Kristiansen, Maria; Younis, Tarek; Hassani, Amani
2015-01-01
In this article, we explore how Islam, minority status and refugee experiencesintersect in shaping meaning-making processes following bereavement. We do this througha phenomenological analysis of a biographical account of personal loss told by Aisha, a Muslim Palestinian refugee living in Denmark......, who narrates her experience of losing herhusband to lung cancer. By drawing on a religious framework, Aisha creates meaning fromher loss, which enables her to incorporate this loss into her life history and sustain agency.Her narrative invites wider audiences to witness her tale of overcoming loss...
Clustering Coefficients for Correlation Networks.
Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu
2018-01-01
Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly
Clustering Coefficients for Correlation Networks
Directory of Open Access Journals (Sweden)
Naoki Masuda
2018-03-01
Full Text Available Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients
Clustering Coefficients for Correlation Networks
Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu
2018-01-01
Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly
Nondestructive hall coefficient measurements using ACPD techniques
Velicheti, Dheeraj; Nagy, Peter B.; Hassan, Waled
2018-04-01
Hall coefficient measurements offer great opportunities as well as major challenges for nondestructive materials characterization. The Hall effect is produced by the magnetic Lorentz force acting on moving charge carriers in the presence of an applied magnetic field. The magnetic perturbation gives rise to a Hall current that is normal to the conduction current but does not directly perturb the electric potential distribution. Therefore, Hall coefficient measurements usually exploit the so-called transverse galvanomagnetic potential drop effect that arises when the Hall current is intercepted by the boundaries of the specimen and thereby produce a measurable potential drop. In contrast, no Hall potential is produced in a large plate in the presence of a uniform normal field at quasi-static low frequencies. In other words, conventional Hall coefficient measurements are inherently destructive since they require cutting the material under tests. This study investigated the feasibility of using alternating current potential drop (ACPD) techniques for nondestructive Hall coefficient measurements in plates. Specifically, the directional four-point square-electrode configuration is investigated with superimposed external magnetic field. Two methods are suggested to make Hall coefficient measurements in large plates without destructive machining. At low frequencies, constraining the bias magnetic field can replace constraining the dimensions of the specimen, which is inherently destructive. For example, when a cylindrical permanent magnet is used to provide the bias magnetic field, the peak Hall voltage is produced when the diameter of the magnet is equal to the diagonal of the square ACPD probe. Although this method is less effective than cutting the specimen to a finite size, the loss of sensitivity is less than one order of magnitude even at very low frequencies. In contrast, at sufficiently high inspection frequencies the magnetic field of the Hall current induces a
Meromorphic univalent function with negative coefficient
Directory of Open Access Journals (Sweden)
A. Dernek
1994-01-01
Full Text Available Let Mn be the classes of regular functions f(z=z−1+a0+a1z+… defined in the annulus 00, (n∈ℕ0, where I0f(z=f(z, If(z=(z−1−z(z−1−2∗f(z, Inf(z=I(In−1f(z, and ∗ is the Hadamard convolution. We denote by Γn=Mn⋃Γ, where Γ denotes the class of functions of the form f(z=z−1+∑k=1∞|ak|zk. We obtained that relates the modulus of the coefficients to starlikeness for the classes Mn and Γn, and coefficient inequalities for the classes Γn.
Converting Sabine absorption coefficients to random incidence absorption coefficients
DEFF Research Database (Denmark)
Jeong, Cheol-Ho
2013-01-01
are suggested: An optimization method for the surface impedances for locally reacting absorbers, the flow resistivity for extendedly reacting absorbers, and the flow resistance for fabrics. With four porous type absorbers, the conversion methods are validated. For absorbers backed by a rigid wall, the surface...... coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations...... impedance optimization produces the best results, while the flow resistivity optimization also yields reasonable results. The flow resistivity and flow resistance optimization for extendedly reacting absorbers are also found to be successful. However, the theoretical conversion factors based on Miki's model...
... barbiturates or ( hypnotics ) ECT (electroconvulsive therapy) (most often short-term memory loss) Epilepsy that is not well controlled Illness that ... appointment. Medical history questions may include: Type of memory loss, such as short-term or long-term Time pattern, such as how ...
Determination of extinction coefficients of human hemoglobin in various redox states.
Meng, Fantao; Alayash, Abdu I
2017-03-15
The role of hemoglobin (Hb) redox forms in tissue and organ toxicities remain ambiguous despite the well-documented contribution of Hb redox reactivity to cellular and subcellular oxidative changes. Moreover, several recent studies, in which Hb toxicity were investigated, have shown conflicting outcomes. Uncertainties over the potential role of these species may in part be due to the protein preparation method of choice, the use of published extinction coefficients and the lack of suitable controls for Hb oxidation and heme loss. Highly purified and well characterized redox forms of human Hb were used in this study and the extinction coefficients of each Hb species (ferrous/oxy, ferric/met and ferryl) were determined. A new set of equations were established to improve accuracy in determining the transient ferryl Hb species. Additionally, heme concentrations in solutions and in human plasma were determined using a novel reversed phase HPLC method in conjugation with our photometric measurements. The use of more accurate redox-specific extinction coefficients and method calculations will be an invaluable tool for both in vitro and in vivo experiments aimed at determining the role of Hb-mediated vascular pathology in hemolytic anemias and when Hb is used as oxygen therapeutics. Published by Elsevier Inc.
International Nuclear Information System (INIS)
Chantler, C.T.
2000-01-01
Reliable knowledge of the complex x-ray form factor [Re(f ) ] and the photoelectric attenuation coefficient (σ PE ) is required for crystallography, medical diagnosis, radiation safety, and XAFS studies. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 to 3 keV x-ray energies. The key discrepancies are due to the smoothing of edge structure, the use of nonrelativistic wave functions, and the lack of appropriate convergence of wave functions. This paper addresses these key discrepancies and derives new theoretical results of substantially higher accuracy in near-edge soft x-ray regions. The high-energy limitations of the current approach are also illustrated. The energy range covered is 0.1 to 10 keV. The associated figures and tabulation demonstrate the current comparison with alternate theory and with available experimental data. In general, experimental data are not sufficiently accurate to establish the errors and inadequacies of theory at this level. However, the best experimental data and the observed experimental structure as a function of energy are strong indicators of the validity of the current approach. New developments in experimental measurement hold great promise in making critical comparisons with theory in the near future
International Nuclear Information System (INIS)
Chantler, C.T.
1998-01-01
Reliable knowledge of the complex X-ray form factor (Re(f) and f ) and the photoelectric attenuation coefficient σ PE is required for crystallography, medical diagnosis, radiation safety and XAFS studies. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 keV to 3 keV X-ray energies. The key discrepancies are due to the smoothing of edge structure, the use of non-relativistic wavefunctions, and the lack of appropriate convergence of wavefunctions. This paper addresses these key discrepancies and derives new theoretical results of substantially higher accuracy in near-edge soft X-ray regions. The high-energy limitations of the current approach are also illustrated. The associated figures and tabulation demonstrate the current comparison with alternate theory and with available experimental data. In general, experimental data is not sufficiently accurate to establish the errors and inadequacies of theory at this level. However, the best experimental data and the observed experimental structure as a function of energy are strong indicators of the validity of the current approach. New developments in experimental measurement hold great promise in making critical comparisons with theory in the near future. (authors)
Amide temperature coefficients in the protein G B1 domain
International Nuclear Information System (INIS)
Tomlinson, Jennifer H.; Williamson, Mike P.
2012-01-01
Temperature coefficients have been measured for backbone amide 1 H and 15 N nuclei in the B1 domain of protein G (GB1), using temperatures in the range 283–313 K, and pH values from 2.0 to 9.0. Many nuclei display pH-dependent coefficients, which were fitted to one or two pK a values. 1 H coefficients showed the expected behaviour, in that hydrogen-bonded amides have less negative values, but for those amides involved in strong hydrogen bonds in regular secondary structure there is a negative correlation between strength of hydrogen bond and size of temperature coefficient. The best correlation to temperature coefficient is with secondary shift, indicative of a very approximately uniform thermal expansion. The largest pH-dependent changes in coefficient are for amides in loops adjacent to sidechain hydrogen bonds rather than the amides involved directly in hydrogen bonds, indicating that the biggest determinant of the temperature coefficient is temperature-dependent loss of structure, not hydrogen bonding. Amide 15 N coefficients have no clear relationship with structure.
Effect of Variable Manning Coefficients on Tsunami Inundation
Barberopoulou, A.; Rees, D.
2017-12-01
Numerical simulations are commonly used to help estimate tsunami hazard, improve evacuation plans, issue or cancel tsunami warnings, inform forecasting and hazard assessments and have therefore become an integral part of hazard mitigation among the tsunami community. Many numerical codes exist for simulating tsunamis, most of which have undergone extensive benchmarking and testing. Tsunami hazard or risk assessments employ these codes following a deterministic or probabilistic approach. Depending on the scope these studies may or may not consider uncertainty in the numerical simulations, the effects of tides, variable friction or estimate financial losses, none of which are necessarily trivial. Distributed manning coefficients, the roughness coefficients used in hydraulic modeling, are commonly used in simulating both riverine and pluvial flood events however, their use in tsunami hazard assessments is primarily part of limited scope studies and for the most part, not a standard practice. For this work, we investigate variations in manning coefficients and their effects on tsunami inundation extent, pattern and financial loss. To assign manning coefficients we use land use maps that come from the New Zealand Land Cover Database (LCDB) and more recent data from the Ministry of the Environment. More than 40 classes covering different types of land use are combined into major classes such as cropland, grassland and wetland representing common types of land use in New Zealand, each of which is assigned a unique manning coefficient. By utilizing different data sources for variable manning coefficients, we examine the impact of data sources and classification methodology on the accuracy of model outputs.
Analysis of internal conversion coefficients
International Nuclear Information System (INIS)
Coursol, N.; Gorozhankin, V.M.; Yakushev, E.A.; Briancon, C.; Vylov, Ts.
2000-01-01
An extensive database has been assembled that contains the three most widely used sets of calculated internal conversion coefficients (ICC): [Hager R.S., Seltzer E.C., 1968. Internal conversion tables. K-, L-, M-shell Conversion coefficients for Z=30 to Z=103, Nucl. Data Tables A4, 1-237; Band I.M., Trzhaskovskaya M.B., 1978. Tables of gamma-ray internal conversion coefficients for the K-, L- and M-shells, 10≤Z≤104, Special Report of Leningrad Nuclear Physics Institute; Roesel F., Fries H.M., Alder K., Pauli H.C., 1978. Internal conversion coefficients for all atomic shells, At. Data Nucl. Data Tables 21, 91-289] and also includes new Dirac-Fock calculations [Band I.M. and Trzhaskovskaya M.B., 1993. Internal conversion coefficients for low-energy nuclear transitions, At. Data Nucl. Data Tables 55, 43-61]. This database is linked to a computer program to plot ICCs and their combinations (sums and ratios) as a function of Z and energy, as well as relative deviations of ICC or their combinations for any pair of tabulated data. Examples of these analyses are presented for the K-shell and total ICCs of the gamma-ray standards [Hansen H.H., 1985. Evaluation of K-shell and total internal conversion coefficients for some selected nuclear transitions, Eur. Appl. Res. Rept. Nucl. Sci. Tech. 11.6 (4) 777-816] and for the K-shell and total ICCs of high multipolarity transitions (total, K-, L-, M-shells of E3 and M3 and K-shell of M4). Experimental data sets are also compared with the theoretical values of these specific calculations
Investigation of Wear Coefficient of Manganese Phosphate Coated Tool Steel
Directory of Open Access Journals (Sweden)
S. Ilaiyavel
2013-03-01
Full Text Available In recent years the properties of the coating in terms of wear resistance is of paramount importance in order to prevent the formation of severe damages. In this study, Wear coefficient of uncoated, Manganese Phosphate coated, Manganese Phosphate coated with oil lubricant, Heat treated Manganese Phosphate coated with oil lubricant on AISI D2 steels was investigated using Archard’s equation. The wear tests were performed in a pin on disk apparatus as per ASTM G-99 Standard. The volumetric wear loss and wear coefficient were evaluated through pin on disc test using a sliding velocity of 3.0 m/s under normal load of 40 N and controlled condition of temperature and humidity. Based on the results of the wear test, the Heat treated Manganese Phosphate with oil lubricant exhibited the lowest average wear coefficient and the lowest wear loss under 40 N load.
Miles, Rachael E H; Davies, James F; Reid, Jonathan P
2016-07-20
We explore the dependence of the evaporation coefficient of water from aqueous droplets on the composition of a surface film, considering in particular the influence of monolayer mixed component films on the evaporative mass flux. Measurements with binary component films formed from long chain alcohols, specifically tridecanol (C13H27OH) and pentadecanol (C15H31OH), and tetradecanol (C14H29OH) and hexadecanol (C16H33OH), show that the evaporation coefficient is dependent on the mole fractions of the two components forming the monolayer film. Immediately at the point of film formation and commensurate reduction in droplet evaporation rate, the evaporation coefficient is equal to a mole fraction weighted average of the evaporation coefficients through the equivalent single component films. As a droplet continues to diminish in surface area with continued loss of water, the more-soluble, shorter alkyl chain component preferentially partitions into the droplet bulk with the evaporation coefficient tending towards that through a single component film formed simply from the less-soluble, longer chain alcohol. We also show that the addition of a long chain alcohol to an aqueous-sucrose droplet can facilitate control over the degree of dehydration achieved during evaporation. After undergoing rapid gas-phase diffusion limited water evaporation, binary aqueous-sucrose droplets show a continued slow evaporative flux that is limited by slow diffusional mass transport within the particle bulk due to the rapidly increasing particle viscosity and strong concentration gradients that are established. The addition of a long chain alcohol to the droplet is shown to slow the initial rate of water loss, leading to a droplet composition that remains more homogeneous for a longer period of time. When the sucrose concentration has achieved a sufficiently high value, and the diffusion constant of water has decreased accordingly so that bulk phase diffusion arrest occurs in the monolayer
Determination of coefficient matrices for ARMA model
International Nuclear Information System (INIS)
Tran Dinh Tri.
1990-10-01
A new recursive algorithm for determining coefficient matrices of ARMA model from measured data is presented. The Yule-Walker equations for the case of ARMA model are derived from the ARMA innovation equation. The recursive algorithm is based on choosing appropriate form of the operator functions and suitable representation of the (n+1)-th order operator functions according to ones with the lower order. Two cases, when the order of the AR part is equal to one of the MA part, and the optimal case, were considered. (author) 5 refs
... Rights Employment Discrimination Health Care Professionals Law Enforcement Driver's License For Lawyers Food & Fitness Home Food MyFoodAdvisor ... Fit Types of Activity Weight Loss Assess Your Lifestyle Getting Started Food Choices In My Community Home ...
Irrational "Coefficients" in Renaissance Algebra.
Oaks, Jeffrey A
2017-06-01
Argument From the time of al-Khwārizmī in the ninth century to the beginning of the sixteenth century algebraists did not allow irrational numbers to serve as coefficients. To multiply by x, for instance, the result was expressed as the rhetorical equivalent of . The reason for this practice has to do with the premodern concept of a monomial. The coefficient, or "number," of a term was thought of as how many of that term are present, and not as the scalar multiple that we work with today. Then, in sixteenth-century Europe, a few algebraists began to allow for irrational coefficients in their notation. Christoff Rudolff (1525) was the first to admit them in special cases, and subsequently they appear more liberally in Cardano (1539), Scheubel (1550), Bombelli (1572), and others, though most algebraists continued to ban them. We survey this development by examining the texts that show irrational coefficients and those that argue against them. We show that the debate took place entirely in the conceptual context of premodern, "cossic" algebra, and persisted in the sixteenth century independent of the development of the new algebra of Viète, Decartes, and Fermat. This was a formal innovation violating prevailing concepts that we propose could only be introduced because of the growing autonomy of notation from rhetorical text.
Integer Solutions of Binomial Coefficients
Gilbertson, Nicholas J.
2016-01-01
A good formula is like a good story, rich in description, powerful in communication, and eye-opening to readers. The formula presented in this article for determining the coefficients of the binomial expansion of (x + y)n is one such "good read." The beauty of this formula is in its simplicity--both describing a quantitative situation…
Regional water coefficients for U.S. industrial sectors
Directory of Open Access Journals (Sweden)
Riccardo Boero
2017-12-01
Full Text Available Designing policies for water systems management requires the capability to assess the economic impacts of water availability and to effectively couple water withdrawals by human activities with natural hydrologic dynamics. At the core of any scientific approach to these issues there is the estimation of water withdrawals by industrial sectors in the form of water coefficients, which are measurements of the quantity of water withdrawn per dollar of GDP or output. In this work we focus on the contiguous United States and on the estimation of water coefficients for regional scale analyses. We first compare an established methodology for the estimation of national water coefficients with a parametric one we propose. Second, we introduce a method to estimate water coefficients at the level of ecological regions and we discuss how they reduce possible biases in regional analyses of water systems. We conclude discussing advantages and limits of regional water coefficients.
Integral linear momentum balance in combining flows for calculating the pressure drop coefficients
International Nuclear Information System (INIS)
Bollmann, A.
1983-01-01
Equations for calculating the loss coefficient in combining flows in tee functions are obtained by an integral linear momentum balance. It is a practice, when solving this type of problem, to neglect the pressure difference in the upstream location as well as the wall-fluid interaction in the lateral branch of the junction. In this work it is demonstrated the influence of the above parameters on the loss coefficient based on experimental values and by apropriate algebraic manipulation of the loss coefficient values published by previous investigators. (Author) [pt
Operator product expansion on the lattice: analytic Wilson coefficients
Perlt, Holger
2006-12-01
We present first results for Wilson coefficients of operators up to first order in the covariant deriva- tives for the case of Wilson fermions. They are derived from the off-shell Compton scattering amplitude Wµν (a, p, q) of massless quarks with momentum p. The Wilson coefficients are clas- sified according to the transformation of the corresponding operators under the hypercubic group H(4). We give selected examples for a special choice of the momentum transfer q. All Wil- son coefficients are given in closed analytic form and in an expansion in powers of a up to first corrections.
Pearson's correlation coefficient in the theory of networks: A comment
Ahmed, Zafar; Kumar, Sachin
2018-01-01
In statistics, the Pearson correlation coefficient $r_{x,y}$ determines the degree of linear correlation between two variables and it is known that $-1 \\le r_{x,y} \\le 1$. In the theory of networks, a curious expression proposed in [PRL {\\bf 89} 208701 (2002)] for degree-degree correlation coefficient $r_{j_i,k_i}, i\\in [1,M]$ has been in use. We realize that the suggested form is the conventional Pearson's coefficient for $\\{(j_i,k_i), (k_i,j_i)\\}$ for $2M$ data points and hence it is rightl...
DEFF Research Database (Denmark)
Kieffer-Kristensen, Rikke; Johansen, Karen Lise Gaardsvig
2013-01-01
to participate. RESULTS: All children were affected by their parents' ABI and the altered family situation. The children's expressions led the authors to identify six themes, including fear of losing the parent, distress and estrangement, chores and responsibilities, hidden loss, coping and support. The main......PRIMARY OBJECTIVE: The purpose of this study was to listen to and learn from children showing high levels of post-traumatic stress symptoms after parental acquired brain injury (ABI), in order to achieve an in-depth understanding of the difficulties the children face in their everyday lives...... finding indicates that the children experienced numerous losses, many of which were often suppressed or neglected by the children to protect the ill parents. CONCLUSIONS: The findings indicated that the children seemed to make a special effort to hide their feelings of loss and grief in order to protect...
Thomsen, M. F.; Goertz, C. K.; Van Allen, J. A.
1977-01-01
In a previous paper (Thomsen et al., 1977), a technique was proposed for estimating the radial diffusion coefficient (n) in the inner magnetosphere of Jupiter from the observations of the sweeping effect of the inner Jovian satellites on the fluxes of the energetic charged particles. The present paper extends this technique to permit the unique identification of the parameters D sub O and n, where the diffusion coefficient is assumed to be of the form D = D sub O L to the nth. The derived value of D sub O depends directly on assumptions regarding the nature and efficiency of the loss mechanism operating on the particles, while the value of n depends only on the assumed width of the loss region. The extended technique is applied to the University of Iowa Pioneer 11 proton data, leading to values of n of about O and D(6) of about 3 x 10 to the -8th (R sub J)-squared/sec, when satellite sweepup losses are assumed to be the only loss operating on the protons. The small value of n is strong evidence that the radial diffusion is driven by ionospheric winds.
International Nuclear Information System (INIS)
Brunish, W.M.; Guzik, J.A.; Willson, L.A.; Bowen, G.
1987-01-01
It has been hypothesized that variable stars may experience mass loss, driven, at least in part, by oscillations. The class of stars we are discussing here are the δ Scuti variables. These are variable stars with masses between about 1.2 and 2.25 M/sub θ/, lying on or very near the main sequence. According to this theory, high rotation rates enhance the rate of mass loss, so main sequence stars born in this mass range would have a range of mass loss rates, depending on their initial rotation velocity and the amplitude of the oscillations. The stars would evolve rapidly down the main sequence until (at about 1.25 M/sub θ/) a surface convection zone began to form. The presence of this convective region would slow the rotation, perhaps allowing magnetic braking to occur, and thus sharply reduce the mass loss rate. 7 refs
Calibration factor or calibration coefficient?
International Nuclear Information System (INIS)
Meghzifene, A.; Shortt, K.R.
2002-01-01
Full text: The IAEA/WHO network of SSDLs was set up in order to establish links between SSDL members and the international measurement system. At the end of 2001, there were 73 network members in 63 Member States. The SSDL network members provide calibration services to end-users at the national or regional level. The results of the calibrations are summarized in a document called calibration report or calibration certificate. The IAEA has been using the term calibration certificate and will continue using the same terminology. The most important information in a calibration certificate is a list of calibration factors and their related uncertainties that apply to the calibrated instrument for the well-defined irradiation and ambient conditions. The IAEA has recently decided to change the term calibration factor to calibration coefficient, to be fully in line with ISO [ISO 31-0], which recommends the use of the term coefficient when it links two quantities A and B (equation 1) that have different dimensions. The term factor should only be used for k when it is used to link the terms A and B that have the same dimensions A=k.B. However, in a typical calibration, an ion chamber is calibrated in terms of a physical quantity such as air kerma, dose to water, ambient dose equivalent, etc. If the chamber is calibrated together with its electrometer, then the calibration refers to the physical quantity to be measured per electrometer unit reading. In this case, the terms referred have different dimensions. The adoption by the Agency of the term coefficient to express the results of calibrations is consistent with the 'International vocabulary of basic and general terms in metrology' prepared jointly by the BIPM, IEC, ISO, OIML and other organizations. The BIPM has changed from factor to coefficient. The authors believe that this is more than just a matter of semantics and recommend that the SSDL network members adopt this change in terminology. (author)
Extinction Coefficient of Gold Nanostars
de Puig, Helena; Tam, Justina O.; Yen, Chun-Wan; Gehrke, Lee; Hamad-Schifferli, Kimberly
2015-01-01
Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes, and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPR), which range from 5.7 × 108 to 26.8 × 108 M−1cm−1. Measured values correl...
Generalization of Binomial Coefficients to Numbers on the Nodes of Graphs
Khmelnitskaya, A.; van der Laan, G.; Talman, Dolf
2016-01-01
The triangular array of binomial coefficients, or Pascal's triangle, is formed by starting with an apex of 1. Every row of Pascal's triangle can be seen as a line-graph, to each node of which the corresponding binomial coefficient is assigned. We show that the binomial coefficient of a node is equal
Generalization of binomial coefficients to numbers on the nodes of graphs
Khmelnitskaya, Anna Borisovna; van der Laan, Gerard; Talman, Dolf
The triangular array of binomial coefficients, or Pascal's triangle, is formed by starting with an apex of 1. Every row of Pascal's triangle can be seen as a line-graph, to each node of which the corresponding binomial coefficient is assigned. We show that the binomial coefficient of a node is equal
Study of transport coefficients of nanodiamond nanofluids
Pryazhnikov, M. I.; Minakov, A. V.; Guzei, D. V.
2017-09-01
Experimental data on the thermal conductivity coefficient and viscosity coefficient of nanodiamond nanofluids are presented. Distilled water and ethylene glycol were used as the base fluid. Dependences of transport coefficients on concentration are obtained. It was shown that the thermal conductivity coefficient increases with increasing nanodiamonds concentration. It was shown that base fluids properties and nanodiamonds concentration affect on the rheology of nanofluids.
International Nuclear Information System (INIS)
Ward, G.M.; Johnson, J.E.
1985-01-01
The goat milk transfer coefficient of Tc administered as TcO 4 - was found to be 20 to 40 times that of Tc administered in a reduced form. The fraction of Tc, as TcO 4 - , transferred from gut to blood was approximately 6 to 10 times that of reduced Tc. The milk transfer coefficient of Tc administered as TcO 4 - was 6 to 8 times greater for goats than cows. The fraction of Tc, as TcO 4 - , absorbed from the gut by cows, however, was approximately twice that absorbed by goats. The mean time for loss of Tc in cows' milk based on the average values plotted in Figure 2 was approximately 10 hours. The fraction of Tc, administered as TcO 4 - , absorbed from blood to mammary gland by cows was estimated to be approximately 2% that of goats. 4 refs., 15 tabs
Correlation coefficients in neutron β-decay
International Nuclear Information System (INIS)
Byrne, J.
1978-01-01
The various angular and polarisation coefficients in neutron decay are the principal sources of information on the β-interaction. Measurements of the electron-neutrino angular correlation coefficient (a), the neutron-spin-electron-momentum correlation coefficient (A), the neutron-spin-neutrino-momentum correlation coefficient (B), and the triple correlation coefficient D and time-reversal invariance are reviewed and the results discussed. (U.K.)
Ion heat conduction losses in Extrap
International Nuclear Information System (INIS)
Tennfors, E.
1989-08-01
The classical ion heat conduction losses in Extrap discharges are calculated using polynomial magnetic field profiles and compared to the power input. For polynomials matched to magnetic field profiles measured in present experiments, these losses are small. By varying the coefficients of the polynomials, a region is found, where the power input can balance the classical heat conduction losses. Each set of coefficients corresponds to values of the parameters F and Θ used in RFP physics. The region determines a region in an F-Θ diagram, including the usual RFP region but extending to higher values of Θ and βΘ
Linearized gravity in terms of differential forms
Baykal, Ahmet; Dereli, Tekin
2017-01-01
A technique to linearize gravitational field equations is developed in which the perturbation metric coefficients are treated as second rank, symmetric, 1-form fields belonging to the Minkowski background spacetime by using the exterior algebra of differential forms.
Coefficient of friction of a starved lubricated spur gear pair
International Nuclear Information System (INIS)
Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng
2016-01-01
The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.
Coefficient of performance of Stirling refrigerators
E Mungan, Carl
2017-09-01
Stirling coolers transfer heat in or out of the working fluid during all four stages of their operation, and their coefficient of performance depends on whether the non-isothermal heat exchanges are performed reversibly or irreversibly. Both of these possibilities can in principle be arranged. Notably, if the working fluid is an ideal gas, the input of energy in the form of heat during one isochoric step is equal in magnitude to the output during the other isochoric step in the cycle. The theoretical performance of the fridge can then attain the reversible Carnot limit if a regenerator is used, which is a high heat capacity material through which the gas flows. Various Stirling refrigerator configurations are analysed in this article at a level of presentation suitable for an introductory undergraduate thermodynamics course.
Schlichting, Hilke E.; Mukhopadhyay, Sujoy
2018-02-01
Determining the origin of volatiles on terrestrial planets and quantifying atmospheric loss during planet formation is crucial for understanding the history and evolution of planetary atmospheres. Using geochemical observations of noble gases and major volatiles we determine what the present day inventory of volatiles tells us about the sources, the accretion process and the early differentiation of the Earth. We further quantify the key volatile loss mechanisms and the atmospheric loss history during Earth's formation. Volatiles were accreted throughout the Earth's formation, but Earth's early accretion history was volatile poor. Although nebular Ne and possible H in the deep mantle might be a fingerprint of this early accretion, most of the mantle does not remember this signature implying that volatile loss occurred during accretion. Present day geochemistry of volatiles shows no evidence of hydrodynamic escape as the isotopic compositions of most volatiles are chondritic. This suggests that atmospheric loss generated by impacts played a major role during Earth's formation. While many of the volatiles have chondritic isotopic ratios, their relative abundances are certainly not chondritic again suggesting volatile loss tied to impacts. Geochemical evidence of atmospheric loss comes from the {}3He/{}^{22}Ne, halogen ratios (e.g., F/Cl) and low H/N ratios. In addition, the geochemical ratios indicate that most of the water could have been delivered prior to the Moon forming impact and that the Moon forming impact did not drive off the ocean. Given the importance of impacts in determining the volatile budget of the Earth we examine the contributions to atmospheric loss from both small and large impacts. We find that atmospheric mass loss due to impacts can be characterized into three different regimes: 1) Giant Impacts, that create a strong shock transversing the whole planet and that can lead to atmospheric loss globally. 2) Large enough impactors (m_{cap} ≳ √{2
Extinction Coefficient of Gold Nanostars.
de Puig, Helena; Tam, Justina O; Yen, Chun-Wan; Gehrke, Lee; Hamad-Schifferli, Kimberly
2015-07-30
Gold nanostars (NStars) are highly attractive for biological applications due to their surface chemistry, facile synthesis and optical properties. Here, we synthesize NStars in HEPES buffer at different HEPES/Au ratios, producing NStars of different sizes and shapes, and therefore varying optical properties. We measure the extinction coefficient of the synthesized NStars at their maximum surface plasmon resonances (SPR), which range from 5.7 × 10 8 to 26.8 × 10 8 M -1 cm -1 . Measured values correlate with those obtained from theoretical models of the NStars using the discrete dipole approximation (DDA), which we use to simulate the extinction spectra of the nanostars. Finally, because NStars are typically used in biological applications, we conjugate DNA and antibodies to the NStars and calculate the footprint of the bound biomolecules.
Kerr scattering coefficients via isomonodromy
Energy Technology Data Exchange (ETDEWEB)
Cunha, Bruno Carneiro da [Departamento de Física, Universidade Federal de Pernambuco,50670-901, Recife, Pernambuco (Brazil); Novaes, Fábio [International Institute of Physics, Federal University of Rio Grande do Norte,Av. Odilon Gomes de Lima 1722, Capim Macio, Natal-RN 59078-400 (Brazil)
2015-11-23
We study the scattering of a massless scalar field in a generic Kerr background. Using a particular gauge choice based on the current conservation of the radial equation, we give a generic formula for the scattering coefficient in terms of the composite monodromy parameter σ between the inner and the outer horizons. Using the isomonodromy flow, we calculate σ exactly in terms of the Painlevé V τ-function. We also show that the eigenvalue problem for the angular equation (spheroidal harmonics) can be calculated using the same techniques. We use recent developments relating the Painlevé V τ-function to Liouville irregular conformal blocks to claim that this scattering problem is solved in the combinatorial sense, with known expressions for the τ-function near the critical points.
Weight Loss Nutritional Supplements
Eckerson, Joan M.
Obesity has reached what may be considered epidemic proportions in the United States, not only for adults but for children. Because of the medical implications and health care costs associated with obesity, as well as the negative social and psychological impacts, many individuals turn to nonprescription nutritional weight loss supplements hoping for a quick fix, and the weight loss industry has responded by offering a variety of products that generates billions of dollars each year in sales. Most nutritional weight loss supplements are purported to work by increasing energy expenditure, modulating carbohydrate or fat metabolism, increasing satiety, inducing diuresis, or blocking fat absorption. To review the literally hundreds of nutritional weight loss supplements available on the market today is well beyond the scope of this chapter. Therefore, several of the most commonly used supplements were selected for critical review, and practical recommendations are provided based on the findings of well controlled, randomized clinical trials that examined their efficacy. In most cases, the nutritional supplements reviewed either elicited no meaningful effect or resulted in changes in body weight and composition that are similar to what occurs through a restricted diet and exercise program. Although there is some evidence to suggest that herbal forms of ephedrine, such as ma huang, combined with caffeine or caffeine and aspirin (i.e., ECA stack) is effective for inducing moderate weight loss in overweight adults, because of the recent ban on ephedra manufacturers must now use ephedra-free ingredients, such as bitter orange, which do not appear to be as effective. The dietary fiber, glucomannan, also appears to hold some promise as a possible treatment for weight loss, but other related forms of dietary fiber, including guar gum and psyllium, are ineffective.
DEFF Research Database (Denmark)
von Essen, Flemming Brændgaard
The Taylor coefficients of weight k Eisenstein series wrt. SL2(Z) are related to values of L-functions for Hecke characters in the point k. We show some congruences for Taylor coefficients of Eisenstein series of weight 4 and 6 and use them to establish congruences for values of L......-functions for Hecke characters in the points 4 and 6. It is well known, that all zeros of the Eisenstein series Ek wrt. SL2(Z) in the standard fundamental domain has modulus 1. We show that this is also true for #n Ek, where # is a certain differential operator. We then proceed to study logarithms of multiplier...
International Development Research Centre (IDRC) Digital Library (Canada)
Dorine Odongo
COLLABORATING TECHNICAL AGENCIES: EXPRESSION OF INTEREST FORM. • Please read the information provided about the initiative and the eligibility requirements in the Prospectus before completing this application form. • Ensure all the sections of the form are accurately completed and saved in PDF format.
Edixhoven, B.; van der Geer, G.; Moonen, B.; Edixhoven, B.; van der Geer, G.; Moonen, B.
2008-01-01
Modular forms are functions with an enormous amount of symmetry that play a central role in number theory, connecting it with analysis and geometry. They have played a prominent role in mathematics since the 19th century and their study continues to flourish today. Modular forms formed the
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)
A new population growth map with variable coefficients
International Nuclear Information System (INIS)
Jannussis, A.
1986-01-01
In the present paper it is investigated a simple population growth map with variable coefficients. Moreover, it is studied the new population map of the form xsub(j+1) = axsub(j) (1/(1 + bxsub(j)) -1/(1 + cxsub(j))), c not= b, j = 0, 1,..., which is transformed in an equivalent logistic map
Criticality coefficient calculation for a small PWR using Monte Carlo Transport Code
Energy Technology Data Exchange (ETDEWEB)
Trombetta, Debora M.; Su, Jian, E-mail: dtrombetta@nuclear.ufrj.br, E-mail: sujian@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Chirayath, Sunil S., E-mail: sunilsc@tamu.edu [Department of Nuclear Engineering and Nuclear Security Science and Policy Institute, Texas A and M University, TX (United States)
2015-07-01
Computational models of reactors are increasingly used to predict nuclear reactor physics parameters responsible for reactivity changes which could lead to accidents and losses. In this work, preliminary results for criticality coefficient calculation using the Monte Carlo transport code MCNPX were presented for a small PWR. The computational modeling developed consists of the core with fuel elements, radial reflectors, and control rods inside a pressure vessel. Three different geometries were simulated, a single fuel pin, a fuel assembly and the core, with the aim to compare the criticality coefficients among themselves.The criticality coefficients calculated were: Doppler Temperature Coefficient, Coolant Temperature Coefficient, Coolant Void Coefficient, Power Coefficient, and Control Rod Worth. The coefficient values calculated by the MCNP code were compared with literature results, showing good agreement with reference data, which validate the computational model developed and allow it to be used to perform more complex studies. Criticality Coefficient values for the three simulations done had little discrepancy for almost all coefficients investigated, the only exception was the Power Coefficient. Preliminary results presented show that simple modelling as a fuel assembly can describe changes at almost all the criticality coefficients, avoiding the need of a complex core simulation. (author)
Factorization of Transport Coefficients in Macroporous Media
DEFF Research Database (Denmark)
Shapiro, Alexander; Stenby, Erling Halfdan
2000-01-01
We prove the fundamental theorem about factorization of the phenomenological coefficients for transport in macroporous media. By factorization we mean the representation of the transport coefficients as products of geometric parameters of the porous medium and the parameters characteristic...
Anomalous Seebeck coefficient in boron carbides
International Nuclear Information System (INIS)
Aselage, T.L.; Emin, D.; Wood, C.; Mackinnon, I.D.R.; Howard, I.A.
1987-01-01
Boron carbides exhibit an anomalously large Seebeck coefficient with a temperature coefficient that is characteristic of polaronic hopping between inequivalent sites. The inequivalence in the sites is associated with disorder in the solid. The temperature dependence of the Seebeck coefficient for materials prepared by different techniques provides insight into the nature of the disorder
Standards for Standardized Logistic Regression Coefficients
Menard, Scott
2011-01-01
Standardized coefficients in logistic regression analysis have the same utility as standardized coefficients in linear regression analysis. Although there has been no consensus on the best way to construct standardized logistic regression coefficients, there is now sufficient evidence to suggest a single best approach to the construction of a…
Soccer Ball Lift Coefficients via Trajectory Analysis
Goff, John Eric; Carre, Matt J.
2010-01-01
We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…
Limits of the memory coefficient in measuring correlated bursts
Jo, Hang-Hyun; Hiraoka, Takayuki
2018-03-01
Temporal inhomogeneities in event sequences of natural and social phenomena have been characterized in terms of interevent times and correlations between interevent times. The inhomogeneities of interevent times have been extensively studied, while the correlations between interevent times, often called correlated bursts, are far from being fully understood. For measuring the correlated bursts, two relevant approaches were suggested, i.e., memory coefficient and burst size distribution. Here a burst size denotes the number of events in a bursty train detected for a given time window. Empirical analyses have revealed that the larger memory coefficient tends to be associated with the heavier tail of the burst size distribution. In particular, empirical findings in human activities appear inconsistent, such that the memory coefficient is close to 0, while burst size distributions follow a power law. In order to comprehend these observations, by assuming the conditional independence between consecutive interevent times, we derive the analytical form of the memory coefficient as a function of parameters describing interevent time and burst size distributions. Our analytical result can explain the general tendency of the larger memory coefficient being associated with the heavier tail of burst size distribution. We also find that the apparently inconsistent observations in human activities are compatible with each other, indicating that the memory coefficient has limits to measure the correlated bursts.
Questionnaire discrimination: (re-introducing coefficient δ
Directory of Open Access Journals (Sweden)
Hankins Matthew
2007-05-01
Full Text Available Abstract Background Questionnaires are used routinely in clinical research to measure health status and quality of life. Questionnaire measurements are traditionally formally assessed by indices of reliability (the degree of measurement error and validity (the extent to which the questionnaire measures what it is supposed to measure. Neither of these indices assesses the degree to which the questionnaire is able to discriminate between individuals, an important aspect of measurement. This paper introduces and extends an existing index of a questionnaire's ability to distinguish between individuals, that is, the questionnaire's discrimination. Methods Ferguson (1949 1 derived an index of test discrimination, coefficient δ, for psychometric tests with dichotomous (correct/incorrect items. In this paper a general form of the formula, δG, is derived for the more general class of questionnaires allowing for several response choices. The calculation and characteristics of δG are then demonstrated using questionnaire data (GHQ-12 from 2003–2004 British Household Panel Survey (N = 14761. Coefficients for reliability (α and discrimination (δG are computed for two commonly-used GHQ-12 coding methods: dichotomous coding and four-point Likert-type coding. Results Both scoring methods were reliable (α > 0.88. However, δG was substantially lower (0.73 for the dichotomous coding of the GHQ-12 than for the Likert-type method (δG = 0.96, indicating that the dichotomous coding, although reliable, failed to discriminate between individuals. Conclusion Coefficient δG was shown to have decisive utility in distinguishing between the cross-sectional discrimination of two equally reliable scoring methods. Ferguson's δ has been neglected in discussions of questionnaire design and performance, perhaps because it has not been implemented in software and was restricted to questionnaires with dichotomous items, which are rare in health care research. It is
The Heat Transfer Coefficient of Recycled Concrete Bricks Combination with EPS Insulation Board Wall
Directory of Open Access Journals (Sweden)
Jianhua Li
2015-01-01
Full Text Available Four tectonic forms samples were conducted to test their heat transfer coefficients. By analyzing and comparing the test values and theoretical values of the heat transfer coefficient, a corrected-value calculation method for determining the heat transfer coefficient was proposed; the proposed method was proved to be reasonably correct. The results indicated that the recycled concrete brick wall heat transfer coefficient is higher than that of the clay brick wall, the heat transfer coefficient of recycled concrete brick wall could be effectively reduced when combined with the EPS insulation board, and the sandwich insulation type was better than that of external thermal insulation type.
Determination of photon detector coefficient in neutron flux study
International Nuclear Information System (INIS)
Jedol Dayou; Azali Muhammad; Abd Aziz Mohamed; Abdul Razak Daud; Elias Saniman
1995-01-01
The efficiency of photon detector which is normally used in neutron flux measurement has been studied. The data obtain have been plotted using mathematical models in the form of reciprocal, exponential and semilog equation and subsequently efficiency coefficient of the detector has been determined. Beside that, energy quadratic equation model has also been used. It has been found that equation model selection is very important in the detector efficiency coefficient determination. In the case of energy quadratic equation, it has been found that the selection of energy set influenced the result. It can be concluded that energy quadratic equation is the best model in the neutron flux determination
A Numerical Study of Water Loss Rate Distributions in MDCT-based Human Airway Models
Wu, Dan; Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Lin, Ching-Long
2015-01-01
Both three-dimensional (3D) and one-dimensional (1D) computational fluid dynamics (CFD) methods are applied to study regional water loss in three multi-detector row computed-tomography (MDCT)-based human airway models at the minute ventilations of 6, 15 and 30 L/min. The overall water losses predicted by both 3D and 1D models in the entire respiratory tract agree with available experimental measurements. However, 3D and 1D models reveal different regional water loss rate distributions due to the 3D secondary flows formed at bifurcations. The secondary flows cause local skewed temperature and humidity distributions on inspiration acting to elevate the local water loss rate; and the secondary flow at the carina tends to distribute more cold air to the lower lobes. As a result, the 3D model predicts that the water loss rate first increases with increasing airway generation, and then decreases as the air approaches saturation, while the 1D model predicts a monotonic decrease of water loss rate with increasing airway generation. Moreover, the 3D (or 1D) model predicts relatively higher water loss rates in lower (or upper) lobes. The regional water loss rate can be related to the non-dimensional wall shear stress (τ*) by the non-dimensional mass transfer coefficient (h0*) as h0* = 1.15 τ*0.272, R = 0.842. PMID:25869455
Perron–Frobenius theorem for nonnegative multilinear forms and extensions
Friedland, S.; Gaubert, S.; Han, L.
2013-01-01
We prove an analog of Perron-Frobenius theorem for multilinear forms with nonnegative coefficients, and more generally, for polynomial maps with nonnegative coefficients. We determine the geometric convergence rate of the power algorithm to the unique normalized eigenvector.
Identification of MIMO systems with sparse transfer function coefficients
Qiu, Wanzhi; Saleem, Syed Khusro; Skafidas, Efstratios
2012-12-01
We study the problem of estimating transfer functions of multivariable (multiple-input multiple-output--MIMO) systems with sparse coefficients. We note that subspace identification methods are powerful and convenient tools in dealing with MIMO systems since they neither require nonlinear optimization nor impose any canonical form on the systems. However, subspace-based methods are inefficient for systems with sparse transfer function coefficients since they work on state space models. We propose a two-step algorithm where the first step identifies the system order using the subspace principle in a state space format, while the second step estimates coefficients of the transfer functions via L1-norm convex optimization. The proposed algorithm retains good features of subspace methods with improved noise-robustness for sparse systems.
Reciprocal relations for transmission coefficients - Theory and application
Qu, Jianmin; Achenbach, Jan D.; Roberts, Ronald A.
1989-01-01
The authors present a rigorous proof of certain intuitively plausible reciprocal relations for time harmonic plane-wave transmission and reflection at the interface between a fluid and an anisotropic elastic solid. Precise forms of the reciprocity relations for the transmission coefficients and for the transmitted energy fluxes are derived, based on the reciprocity theorem of elastodynamics. It is shown that the reciprocity relations can be used in conjunction with measured values of peak amplitudes for transmission through a slab of the solid (water-solid-water) to obtain the water-solid coefficients. Experiments were performed for a slab of a unidirectional fiber-reinforced composite. Good agreement of the experimentally measured transmission coefficients with theoretical values was obtained.
Diabetes - vision loss; Retinopathy - vision loss; Low vision; Blindness - vision loss ... of visual aids. Some options include: Magnifiers High power reading glasses Devices that make it easier to ...
A drying coefficient for building materials
DEFF Research Database (Denmark)
Scheffler, Gregor Albrecht; Plagge, Rudolf
2009-01-01
coefficient is defined which can be determined based on measured drying data. The correlation of this coefficient with the water absorption and the vapour diffusion coefficient is analyzed and its additional information content is critically challenged. As result, a drying coefficient has been derived......The drying experiment is an important element of the hygrothermal characterisation of building materials. Contrary to other moisture transport experiments as the vapour diffusion and the water absorption test, it is until now not possible to derive a simple coefficient for the drying. However......, in many cases such a coefficient would be highly appreciated, e.g. in interaction of industry and research or for the distinction and selection of suitable building materials throughout design and practise. This article first highlights the importance of drying experiments for hygrothermal...
Study of pressure losses in the EL 4 cluster
International Nuclear Information System (INIS)
Berriaud, Ch.
1964-01-01
The evolution of research on the EL-4 cluster is examined here from the pressure losses point of view. These may be split up into separate pressure losses along the rode and in pressure losses corresponding to various particularities of the cluster. Tests have been carried out on series of three or four clusters placed in a channel. Water was first used, and then carbon dioxide at 60 bars. In all cases the following two parameters were varied: the Reynolds' number, and the rotation of a cluster around its axis with respect to the surrounding clusters. The influence of the gap between to successive clusters has also been studied. The first tests were carried out on clusters without jackets, the subsequent ones on clusters fitted with jackets. It was thus possible to study various types of element assemblies. The results are given in the form of curves representing: the evolution of the independent pressure loss coefficients as a function of the Reynolds number. (author) [fr
Reactor kinetics revisited: a coefficient based model (CBM)
International Nuclear Information System (INIS)
Ratemi, W.M.
2011-01-01
In this paper, a nuclear reactor kinetics model based on Guelph expansion coefficients calculation ( Coefficients Based Model, CBM), for n groups of delayed neutrons is developed. The accompanying characteristic equation is a polynomial form of the Inhour equation with the same coefficients of the CBM- kinetics model. Those coefficients depend on Universal abc- values which are dependent on the type of the fuel fueling a nuclear reactor. Furthermore, such coefficients are linearly dependent on the inserted reactivity. In this paper, the Universal abc- values have been presented symbolically, for the first time, as well as with their numerical values for U-235 fueled reactors for one, two, three, and six groups of delayed neutrons. Simulation studies for constant and variable reactivity insertions are made for the CBM kinetics model, and a comparison of results, with numerical solutions of classical kinetics models for one, two, three, and six groups of delayed neutrons are presented. The results show good agreements, especially for single step insertion of reactivity, with the advantage of the CBM- solution of not encountering the stiffness problem accompanying the numerical solutions of the classical kinetics model. (author)
Condensation coefficient of water in a weak condensation state
International Nuclear Information System (INIS)
Kobayashi, Kazumichi; Watanabe, Shunsuke; Yamano, Daigo; Yano, Takeru; Fujikawa, Shigeo
2008-01-01
The condensation coefficient of water at a vapor-liquid interface is determined by combining shock tube experiments and numerical simulations of the Gaussian-BGK Boltzmann equation. The time evolution in thickness of a liquid film, which is formed on the shock tube endwall behind the shock wave reflected at the endwall, is measured with an optical interferometer consisting of the physical beam and the reference one. The reference beam is utilized to eliminate systematic noises from the physical beam. The growth rate of the film is evaluated from the measured time evolution and it is incorporated into the kinetic boundary condition for the Boltzmann equation. From a numerical simulation using the boundary condition, the condensation coefficient of water is uniquely deduced. The results show that, in a condition of weak condensation near a vapor-liquid equilibrium state, the condensation coefficient of water is almost equal to the evaporation coefficient estimated by molecular dynamics simulations near a vapor-liquid equilibrium state and it decreases as the system becomes a nonequilibrium state. The condensation coefficient of water is nearly identical with that of methanol [Mikami, S., Kobayashi, K., Ota, T., Fujikawa, S., Yano, T., Ichijo, M., 2006. Molecular gas dynamics approaches to interfacial phenomena accompanied with condensation. Exp. Therm. Fluid Sci. 30, 795-800].
Condensation coefficient of water in a weak condensation state
Kobayashi, Kazumichi; Watanabe, Shunsuke; Yamano, Daigo; Yano, Takeru; Fujikawa, Shigeo
2008-07-01
The condensation coefficient of water at a vapor-liquid interface is determined by combining shock tube experiments and numerical simulations of the Gaussian-BGK Boltzmann equation. The time evolution in thickness of a liquid film, which is formed on the shock tube endwall behind the shock wave reflected at the endwall, is measured with an optical interferometer consisting of the physical beam and the reference one. The reference beam is utilized to eliminate systematic noises from the physical beam. The growth rate of the film is evaluated from the measured time evolution and it is incorporated into the kinetic boundary condition for the Boltzmann equation. From a numerical simulation using the boundary condition, the condensation coefficient of water is uniquely deduced. The results show that, in a condition of weak condensation near a vapor-liquid equilibrium state, the condensation coefficient of water is almost equal to the evaporation coefficient estimated by molecular dynamics simulations near a vapor-liquid equilibrium state and it decreases as the system becomes a nonequilibrium state. The condensation coefficient of water is nearly identical with that of methanol [Mikami, S., Kobayashi, K., Ota, T., Fujikawa, S., Yano, T., Ichijo, M., 2006. Molecular gas dynamics approaches to interfacial phenomena accompanied with condensation. Exp. Therm. Fluid Sci. 30, 795-800].
Apparatus for measurement of coefficient of friction
Slifka, A. J.; Siegwarth, J. D.; Sparks, L. L.; Chaudhuri, Dilip K.
1990-01-01
An apparatus designed to measure the coefficient of friction in certain controlled atmospheres is described. The coefficient of friction observed during high-load tests was nearly constant, with an average value of 0.56. This value is in general agreement with that found in the literature and also with the initial friction coefficient value of 0.67 measured during self-mated friction of 440C steel in an oxygen environment.
New definition of the cell diffusion coefficient
International Nuclear Information System (INIS)
Koehler, P.
1975-01-01
As was shown in a recent work by Gelbard, the usually applied Benoist definition of the cell diffusion coefficient gives two different values if two different definitions of the cell are made. A new definition is proposed that preserves the neutron balance for the homogenized lattice and that is independent of the cell definition. The resulting diffusion coefficient is identical with the main term of Benoist's diffusion coefficient
Optimal portfolio choice under loss aversion
A.B. Berkelaar (Arjan); R.R.P. Kouwenberg (Roy)
2000-01-01
textabstractProspect theory and loss aversion play a dominant role in behavioral finance. In this paper we derive closed-form solutions for optimal portfolio choice under loss aversion. When confronted with gains a loss averse investor behaves similar to a portfolio insurer. When confronted with
Measurement and modeling of interface heat transfer coefficients
International Nuclear Information System (INIS)
Rollett, A.D.; Lewis, H.D.; Dunn, P.S.
1985-01-01
The results of preliminary work on the modeling and measurement of the heat transfer coefficients of metal/mold interfaces is reported. The system investigated is the casting of uranium in graphite molds. The motivation for the work is primarily to improve the accuracy of process modeling of prototype mold designs at the Los Alamos Foundry. The evolution in design of a suitable mold for unidirectional solidification is described, illustrating the value of simulating mold designs prior to use. Experiment indicated a heat transfer coefficient of 2 kW/m 2 /K both with and without superheat. It was possible to distinguish between solidification due to the mold and that due to radiative heat loss. This permitted an experimental estimate of the emissivity, epsilon = 0.2, of the solidified metal
Coefficient of restitution of sports balls: A normal drop test
International Nuclear Information System (INIS)
Haron, Adli; Ismail, K A
2012-01-01
Dynamic behaviour of bodies during impact is investigated through impact experiment, the simplest being a normal drop test. Normally, a drop test impact experiment involves measurement of kinematic data; this includes measurement of incident and rebound velocity in order to calculate a coefficient of restitution (COR). A high speed video camera is employed for measuring the kinematic data where speed is calculated from displacement of the bodies. Alternatively, sensors can be employed to measure speeds, especially for a normal impact where there is no spin of the bodies. This paper compares experimental coefficients of restitution (COR) for various sports balls, namely golf, table tennis, hockey and cricket. The energy loss in term of measured COR and effects of target plate are discussed in relation to the material and construction of these sports balls.
Transfer coefficients in ultracold strongly coupled plasma
Bobrov, A. A.; Vorob'ev, V. S.; Zelener, B. V.
2018-03-01
We use both analytical and molecular dynamic methods for electron transfer coefficients in an ultracold plasma when its temperature is small and the coupling parameter characterizing the interaction of electrons and ions exceeds unity. For these conditions, we use the approach of nearest neighbor to determine the average electron (ion) diffusion coefficient and to calculate other electron transfer coefficients (viscosity and electrical and thermal conductivities). Molecular dynamics simulations produce electronic and ionic diffusion coefficients, confirming the reliability of these results. The results compare favorably with experimental and numerical data from earlier studies.
Comparing linear probability model coefficients across groups
DEFF Research Database (Denmark)
Holm, Anders; Ejrnæs, Mette; Karlson, Kristian Bernt
2015-01-01
of the following three components: outcome truncation, scale parameters and distributional shape of the predictor variable. These results point to limitations in using linear probability model coefficients for group comparisons. We also provide Monte Carlo simulations and real examples to illustrate......This article offers a formal identification analysis of the problem in comparing coefficients from linear probability models between groups. We show that differences in coefficients from these models can result not only from genuine differences in effects, but also from differences in one or more...... these limitations, and we suggest a restricted approach to using linear probability model coefficients in group comparisons....
... care Kids’ zone Video library Find a dermatologist Hair loss Overview Hereditary hair loss: Millions of men ... of hair loss can often be successfully treated. Hair loss: Overview Also called alopecia (al-o-PEE- ...
Nanoscale Electromechanics To Measure Thermal Conductivity, Expansion, and Interfacial Losses.
Mathew, John P; Patel, Raj; Borah, Abhinandan; Maliakkal, Carina B; Abhilash, T S; Deshmukh, Mandar M
2015-11-11
We study the effect of localized Joule heating on the mechanical properties of doubly clamped nanowires under tensile stress. Local heating results in systematic variation of the resonant frequency; these frequency changes result from thermal stresses that depend on temperature dependent thermal conductivity and expansion coefficient. The change in sign of the linear expansion coefficient of InAs is reflected in the resonant response of the system near a bath temperature of 20 K. Using finite element simulations to model the experimentally observed frequency shifts, we show that the thermal conductivity of a nanowire can be approximated in the 10-60 K temperature range by the empirical form κ = bT W/mK, where the value of b for a nanowire was found to be b = 0.035 W/mK(2), significantly lower than bulk values. Also, local heating allows us to independently vary the temperature of the nanowire relative to the clamping points pinned to the bath temperature. We suggest a loss mechanism (dissipation ~10(-4)-10(-5)) originating from the interfacial clamping losses between the metal and the semiconductor nanostructure.
Estimation of radiation losses from sheathed thermocouples
International Nuclear Information System (INIS)
Roberts, I.L.; Coney, J.E.R.; Gibbs, B.M.
2011-01-01
Thermocouples are often used for temperature measurements in heat exchangers. However if the radiation losses from a thermocouple in a high temperature gas flow to colder surroundings are ignored significant errors can occur. Even at moderate temperature differences, these can be significant. Prediction of radiation losses from theory can be problematic, especially in situations where there are large variations in the measured temperatures as the emissivity and radiative heat transfer coefficient of the thermocouple are not constant. The following approach combines experimental results with established empirical relationships to estimate losses due to radiation in an annular heat exchanger at temperatures up to 950 o C. - Highlights: → Sheathed thermocouples are often used to measure temperatures in heat exchangers. → Errors are introduced if radiation losses are ignored. → Radiation losses are environment specific and may be significant. → Experimental and theoretical methods are used to estimate losses. → Hot side maximum temperature 950 o C.
Resummed coefficient function for the shape function
Aglietti, U.
2001-01-01
We present a leading evaluation of the resummed coefficient function for the shape function. It is also shown that the coefficient function is short-distance-dominated. Our results allow relating the shape function computed on the lattice to the physical QCD distributions.
Problems with Discontinuous Diffusion/Dispersion Coefficients
Directory of Open Access Journals (Sweden)
Stefano Ferraris
2012-01-01
accurate on smooth solutions and based on a special numerical treatment of the diffusion/dispersion coefficients that makes its application possible also when such coefficients are discontinuous. Numerical experiments confirm the convergence of the numerical approximation and show a good behavior on a set of benchmark problems in two space dimensions.
Meta-Analysis of Coefficient Alpha
Rodriguez, Michael C.; Maeda, Yukiko
2006-01-01
The meta-analysis of coefficient alpha across many studies is becoming more common in psychology by a methodology labeled reliability generalization. Existing reliability generalization studies have not used the sampling distribution of coefficient alpha for precision weighting and other common meta-analytic procedures. A framework is provided for…
Alternatives to Pearson's and Spearman's Correlation Coefficients
Smarandache, Florentin
2008-01-01
This article presents several alternatives to Pearson's correlation coefficient and many examples. In the samples where the rank in a discrete variable counts more than the variable values, the mixtures that we propose of Pearson's and Spearman's correlation coefficients give better results.
Anomaly coefficients: Their calculation and congruences
International Nuclear Information System (INIS)
Braden, H.W.
1988-01-01
A new method for the calculation of anomaly coefficients is presented. For su(n) some explicit and general expressions are given for these. In particular, certain congruences are discovered and investigated among the leading anomaly coefficients. As an application of these congruences, the absence of global six-dimensional gauge anomalies is shown
Prediction of friction coefficients for gases
Taylor, M. F.
1969-01-01
Empirical relations are used for correlating laminar and turbulent friction coefficients for gases, with large variations in the physical properties, flowing through smooth tubes. These relations have been used to correlate friction coefficients for hydrogen, helium, nitrogen, carbon dioxide and air.
A gain-coefficient switched Alexandrite laser
International Nuclear Information System (INIS)
Lee, Chris J; Van der Slot, Peter J M; Boller, Klaus-J
2013-01-01
We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.
Helioseismic Solar Cycle Changes and Splitting Coefficients
Indian Academy of Sciences (India)
tribpo
Abstract. Using the GONG data for a period over four years, we have studied the variation of frequencies and splitting coefficients with solar cycle. Frequencies and even-order coefficients are found to change signi- ficantly with rising phase of the solar cycle. We also find temporal varia- tions in the rotation rate near the solar ...
Implications of NGA for NEHRP site coefficients
Borcherdt, Roger D.
2012-01-01
Three proposals are provided to update tables 11.4-1 and 11.4-2 of Minimum Design Loads for Buildings and Other Structures (7-10), by the American Society of Civil Engineers (2010) (ASCE/SEI 7-10), with site coefficients implied directly by NGA (Next Generation Attenuation) ground motion prediction equations (GMPEs). Proposals include a recommendation to use straight-line interpolation to infer site coefficients at intermediate values of ̅vs (average shear velocity). Site coefficients are recommended to ensure consistency with ASCE/SEI 7-10 MCER (Maximum Considered Earthquake) seismic-design maps and simplified site-specific design spectra procedures requiring site classes with associated tabulated site coefficients and a reference site class with unity site coefficients. Recommended site coefficients are confirmed by independent observations of average site amplification coefficients inferred with respect to an average ground condition consistent with that used for the MCER maps. The NGA coefficients recommended for consideration are implied directly by the NGA GMPEs and do not require introduction of additional models.
Regional water coefficients for U.S. industrial sectors
Riccardo Boero; Donatella Pasqualini
2017-01-01
Designing policies for water systems management requires the capability to assess the economic impacts of water availability and to effectively couple water withdrawals by human activities with natural hydrologic dynamics. At the core of any scientific approach to these issues there is the estimation of water withdrawals by industrial sectors in the form of water coefficients, which are measurements of the quantity of water withdrawn per dollar of GDP or output. In this work we focus on the c...
Energy Technology Data Exchange (ETDEWEB)
Laforge, P; Millot, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1957-07-01
Authors' mind was attracted by the importance of bore granulometry when employed as powder in boral fabrication. The calculation, object of this report, permits to give values for bore efficiency loss, proportionately to the dimension of spherical or ellipsoidal supposed grains. Grains to be employed should exceptionally only exceed 20 {mu} for a correspondent efficiency loss of 8 per cent about. (author) [French] L'attention des auteurs a ete attiree sur l'importance de la granulometrie du bore employe sous forme de poudre dans la fabrication du boral. Le calcul qui fait l'objet de ce rapport permet de chiffrer la perte d'efficacite du bore en fonction de la dimension des grains supposes spheriques ou ellipsoidaux. Les grains a employer ne devraient qu'exceptionnellement etre superieurs a 20 microns, ce qui correspond a une perte d'efficacite d'environ 8 pour cent. (auteur)
Petcu, Ana; Maxim, A; Haba, Danisia
2009-01-01
The aim of our study was to determine the impact of premature loss of temporary molars upon the longitudinal axis of the first permanent molar. The study sample was formed by 94 orthopanthomografies of child patients with premature loss of lower temporary molars (first or second) after clinical eruption of the first permanent molar. All panoramic radiographs have been realized with the same panoramic unit with 1.4% magnification coefficient and were analyzed using a standardized technique of tracing the images of teeth and bone on matte acetate paper. It was evaluated the angle between longitudinal axis of first permanent lower molar and occlusal plane. It was observed that premature loss of lower second deciduous molar modifies greater the vertical axis of first permanent molar (between 61 degrees and 79 degrees) then premature loss of first lower primary molar. This is perhaps because the loss of space in the case of premature exfoliation of first primary molar is due more to distal drift of canine then mesial drift of molars. The drift to mesial of first permanent molar is more accentuated proportional with the age at which appeared premature loss and so it is loss of leeway space.
Gini coefficient as a life table function
Directory of Open Access Journals (Sweden)
2003-06-01
Full Text Available This paper presents a toolkit for measuring and analyzing inter-individual inequality in length of life by Gini coefficient. Gini coefficient and four other inequality measures are defined on the length-of-life distribution. Properties of these measures and their empirical testing on mortality data suggest a possibility for different judgements about the direction of changes in the degree of inequality by using different measures. A new computational procedure for the estimation of Gini coefficient from life tables is developed and tested on about four hundred real life tables. The estimates of Gini coefficient are precise enough even for abridged life tables with the final age group of 85+. New formulae have been developed for the decomposition of differences between Gini coefficients by age and cause of death. A new method for decomposition of age-components into effects of mortality and composition of population by group is developed. Temporal changes in the effects of elimination of causes of death on Gini coefficient are analyzed. Numerous empirical examples show: Lorenz curves for Sweden, Russia and Bangladesh in 1995, proportional changes in Gini coefficient and four other measures of inequality for the USA in 1950-1995 and for Russia in 1959-2000. Further shown are errors of estimates of Gini coefficient when computed from various types of mortality data of France, Japan, Sweden and the USA in 1900-95, decompositions of the USA-UK difference in life expectancies and Gini coefficients by age and cause of death in 1997. As well, effects of elimination of major causes of death in the UK in 1951-96 on Gini coefficient, age-specific effects of mortality and educational composition of the Russian population on changes in life expectancy and Gini coefficient between 1979 and 1989. Illustrated as well are variations in life expectancy and Gini coefficient across 32 countries in 1996-1999 and associated changes in life expectancy and Gini
Modeling the Design Flow Coefficient of a Centrifugal Compressor Impeller
Directory of Open Access Journals (Sweden)
A. A. Drozdov
2017-01-01
Full Text Available In calculating gas-dynamic characteristics by the universal modeling method it is necessary to determine a non-incidence flow rate through the blades of an impeller because of its relationship with the magnitude of incidence losses. The flow area decreased by the blades of finite thickness and the blades load have impact on the critical streamline direction. The universal modeling method in primary designing uses for this a scheme of replacing the influence of the blade load by the vortex effect with identical circulation. Finally, calculating the inviscid flow around the blades allows selecting a value of the inlet blade angle. For impellers with small design flow coefficients, the condition of the non-incidence inlet for the primary design and for the calculation of the inviscid flow is significantly different. The calculating correctness of the non-incidence regime for the non-viscous flow was checked earlier by measurements of the flow in the impellers. The paper presents CFD calculations of twenty impellers in a tenfold range of design flow coefficients. To provide correct comparison, it takes into account the differences in the value of the loading factor calculated by the programs of inviscid quasi-three-dimensional calculation and CFD programs. Shows the identity of inlet conditions for both methods. To increase primary design accuracy, the calculation model was refined. The formula for calculating vortex-induced velocity involves an empirical coefficient. The analysis of data for 32 impellers with different blade profiling allowed working out formulas for calculating empirical coefficient, depending on the type of an impeller, the blade load and the width of the throat at an impeller inlet. The new scheme-based calculation with the empirical coefficient is accurate enough for the primary design.
Determination of the surface drag coefficient
DEFF Research Database (Denmark)
Mahrt, L.; Vickers, D.; Sun, J.L.
2001-01-01
This study examines the dependence of the surface drag coefficient on stability, wind speed, mesoscale modulation of the turbulent flux and method of calculation of the drag coefficient. Data sets over grassland, sparse grass, heather and two forest sites are analyzed. For significantly unstable...... conditions, the drag coefficient does not depend systematically on z/L but decreases with wind speed for fixed intervals of z/L, where L is the Obukhov length. Even though the drag coefficient for weak wind conditions is sensitive to the exact method of calculation and choice of averaging time, the decrease...... of the drag coefficient with wind speed occurs for all of the calculation methods. A classification of flux calculation methods is constructed, which unifies the most common previous approaches. The roughness length corresponding to the usual Monin-Obukhov stability functions decreases with increasing wind...
Estimation of the simple correlation coefficient.
Shieh, Gwowen
2010-11-01
This article investigates some unfamiliar properties of the Pearson product-moment correlation coefficient for the estimation of simple correlation coefficient. Although Pearson's r is biased, except for limited situations, and the minimum variance unbiased estimator has been proposed in the literature, researchers routinely employ the sample correlation coefficient in their practical applications, because of its simplicity and popularity. In order to support such practice, this study examines the mean squared errors of r and several prominent formulas. The results reveal specific situations in which the sample correlation coefficient performs better than the unbiased and nearly unbiased estimators, facilitating recommendation of r as an effect size index for the strength of linear association between two variables. In addition, related issues of estimating the squared simple correlation coefficient are also considered.
Beijeren, H. van; Kehr, K.W.
1986-01-01
The correlation factor, defined as the ratio between the tracer diffusion coefficient in lattice gases and the diffusion coefficient for a corresponding uncorrelated random walk, is known to assume a very simple form under certain conditions. A simple derivation of this is given with the aid of
Directory of Open Access Journals (Sweden)
Edlaine Linares
Full Text Available Amyotrophic lateral sclerosis (ALS is a fatal neurodegenerative disease characterized by the progressive dysfunction and death of motor neurons by mechanisms that remain unclear. Evidence indicates that oxidative mechanisms contribute to ALS pathology, but classical antioxidants have not performed well in clinical trials. Cyclic nitroxides are an alternative worth exploring because they are multifunctional antioxidants that display low toxicity in vivo. Here, we examine the effects of the cyclic nitroxide tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl on ALS onset and progression in transgenic female rats over-expressing the mutant hSOD1(G93A . Starting at 7 weeks of age, a high dose of tempol (155 mg/day/rat in the rat´s drinking water had marginal effects on the disease onset but decelerated disease progression and extended survival by 9 days. In addition, tempol protected spinal cord tissues as monitored by the number of neuronal cells, and the reducing capability and levels of carbonylated proteins and non-native hSOD1 forms in spinal cord homogenates. Intraperitoneal tempol (26 mg/rat, 3 times/week extended survival by 17 days. This group of rats, however, diverted to a decelerated disease progression. Therefore, it was inconclusive whether the higher protective effect of the lower i.p. dose was due to higher tempol bioavailability, decelerated disease development or both. Collectively, the results show that tempol moderately extends the survival of ALS rats while protecting their cellular and molecular structures against damage. Thus, the results provide proof that cyclic nitroxides are alternatives worth to be further tested in animal models of ALS.
Energy Technology Data Exchange (ETDEWEB)
Takebe, Shinichi; Abe, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
2001-03-01
The distribution coefficient is very important parameter for environmental impact assessment on the disposal of radioactive waste arising from research institutes. The literature survey in the country was mainly carried out for the purpose of selecting the reasonable distribution coefficient value on the utilization of this value in the safety evaluation. This report was arranged much informations on the distribution coefficient for inputting to the database for each literature, and was summarized as a literature information data on the distribution coefficient. (author)
Variation in aerodynamic coefficients with altitude
Directory of Open Access Journals (Sweden)
Faiza Shahid
Full Text Available Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD. Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT, hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig. Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number. Similar simulations for a fixed Mach number â3â and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number. Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects. Keywords: Mach number, Reynolds number, Blunt body, Altitude effect, Angle of attacks
Variation in aerodynamic coefficients with altitude
Shahid, Faiza; Hussain, Mukkarum; Baig, Mirza Mehmood; Haq, Ihtram ul
Precise aerodynamics performance prediction plays key role for a flying vehicle to get its mission completed within desired accuracy. Aerodynamic coefficients for same Mach number can be different at different altitude due to difference in Reynolds number. Prediction of these aerodynamics coefficients can be made through experiments, analytical solution or Computational Fluid Dynamics (CFD). Advancements in computational power have generated the concept of using CFD as a virtual Wind Tunnel (WT), hence aerodynamic performance prediction in present study is based upon CFD (numerical test rig). Simulations at different altitudes for a range of Mach numbers with zero angle of attack are performed to predict axial force coefficient behavior with altitude (Reynolds number). Similar simulations for a fixed Mach number '3' and a range of angle of attacks are also carried out to envisage the variation in normal force and pitching moment coefficients with altitude (Reynolds number). Results clearly depict that the axial force coefficient is a function of altitude (Reynolds number) and increase as altitude increases, especially for subsonic region. Variation in axial force coefficient with altitude (Reynolds number) slightly increases for larger values of angle of attacks. Normal force and pitching moment coefficients do not depend on altitude (Reynolds number) at smaller values of angle of attacks but show slight decrease as altitude increases. Present study suggests that variation of normal force and pitching moment coefficients with altitude can be neglected but the variation of axial force coefficient with altitude should be considered for vehicle fly in dense atmosphere. It is recommended to continue this study to more complex configurations for various Mach numbers with side slip and real gas effects.
Non-vanishing of Taylor coefficients and Poincaré series
DEFF Research Database (Denmark)
O'Sullivan, C.; Risager, Morten S.
2013-01-01
We prove recursive formulas for the Taylor coefficients of cusp forms, such as Ramanujan's Delta function, at points in the upper half-plane. This allows us to show the non-vanishing of all Taylor coefficients of Delta at CM points of small discriminant as well as the non-vanishing of certain...... Poincaré series. At a "generic" point, all Taylor coefficients are shown to be non-zero. Some conjectures on the Taylor coefficients of Delta at CM points are stated....
International Nuclear Information System (INIS)
Topchyan, I.I.; Dokhner, R.D.
1977-01-01
The effect of reorientation of anisotropic point defects in uniform fields of elastic stresses on the relaxation of the elastic coefficients of a crystal was investigated in the nonlinear elasticity theory approximation. In calculating the interaction of point defects with elastic-stress fields was taken into consideration. The expression for the relaxations of the elasticity coefficients are obtained in an analytical form. The relaxation of the second-order elasticity coefficients is due to the dimentional interaction of a point defect with an applied-stress field, whereas the relaxation of the higher-order elasticity coefficients is determined both by dimentional and module effects
International Nuclear Information System (INIS)
Samsonov, A.M.; Fedorenko, V.N.
1981-01-01
The kinetic equation describing temporal evolution of the ultra-relativistic electrons' energy spectrum effected by synchrotron losses and turbulent acceleration is solved for the isotropic part of the electrons' distribution function. The original distribution is assumed to be given in the form of a power spectrum. Turbulence properties are stated by means of the turbulent acceleration coefficient depending on epsilon energy D(epsilon)=D 0 epsilon 3 which is related to the synchrotron losses coefficient b(epsilon)=b 0 epsilon 3 so that the isotropization of the distribution function is provided without essential acceleration of particles. The initial spectrum is conserved up to some values of time t and energy epsilon connected by inequality epsilonb 0 t 0 /D 0 -2 if epsilonD 0 t>>1 and b 0 >>D 0 . Finally, are possible applications of the solution to description of processes in supernova shells and radio galaxies are discussed [ru
Heat transfer coefficient for boiling carbon dioxide
DEFF Research Database (Denmark)
Knudsen, Hans Jørgen Høgaard; Jensen, Per Henrik
1998-01-01
Heat transfer coefficient and pressure drop for boiling carbon dioxide (R744) flowing in a horizontal pipe has been measured. The calculated heat transfer coeeficient has been compared with the Chart correlation of Shah. The Chart Correlation predits too low heat transfer coefficient but the ratio...... between the measured and the calculated heat transfer coefficient is nearly constant and equal 1.9. With this factor the correlation predicts the measured data within 14% (RMS). The pressure drop is of the same order as the measuring uncertainty and the pressure drop has not been compared with correlation's....
Virial Coefficients for the Liquid Argon
Korth, Micheal; Kim, Saesun
2014-03-01
We begin with a geometric model of hard colliding spheres and calculate probability densities in an iterative sequence of calculations that lead to the pair correlation function. The model is based on a kinetic theory approach developed by Shinomoto, to which we added an interatomic potential for argon based on the model from Aziz. From values of the pair correlation function at various values of density, we were able to find viral coefficients of liquid argon. The low order coefficients are in good agreement with theoretical hard sphere coefficients, but appropriate data for argon to which these results might be compared is difficult to find.
Soccer ball lift coefficients via trajectory analysis
International Nuclear Information System (INIS)
Goff, John Eric; Carre, Matt J
2010-01-01
We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.
Soccer ball lift coefficients via trajectory analysis
Energy Technology Data Exchange (ETDEWEB)
Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)
2010-07-15
We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.
Vehicle wheel drag coefficient in relation to travelling velocity - CFD analysis
Leśniewicz, P.; Kulak, M.; Karczewski, M.
2016-10-01
In order to understand the aerodynamic losses associated with a rotating automobile wheel, a detailed characteristics of the drag coefficient in relation to the applied velocity are necessary. Single drag coefficient value is most often reported for the commercially available vehicles, much less is revealed about the influence of particular car components on the energy consumption in various driving cycles. However, detailed flow potential losses determination is desired for performance estimation. To address these needs, the numerical investigation of an isolated wheel is proposed herein.
Experimental evaluation of heat transfer coefficients between radiant ceiling and room
DEFF Research Database (Denmark)
Causone, Francesco; Corgnati, Stefano P.; Filippi, Marco
2009-01-01
The heat transfer coefficients between radiant surfaces and room are influenced by several parameters: surfaces temperature distributions, internal gains, air movements. The aim of this paper is to evaluate the heat transfer coefficients between radiant ceiling and room in typical conditions...... of occupancy of an office or residential building. Internal gains were therefore simulated using heated cylinders and heat losses using cooled surfaces. Evaluations were developed by means of experimental tests in an environmental chamber. Heat transfer coefficient may be expressed separately for radiation...
Comparing two K-category assignments by a K-category correlation coefficient
DEFF Research Database (Denmark)
Gorodkin, Jan
2004-01-01
Predicted assignments of biological sequences are often evaluated by Matthews correlation coefficient. However, Matthews correlation coefficient applies only to cases where the assignments belong to two categories, and cases with more than two categories are often artificially forced into two...... categories by considering what belongs and what does not belong to one of the categories, leading to the loss of information. Here, an extended correlation coefficient that applies to K-categories is proposed, and this measure is shown to be highly applicable for evaluating prediction of RNA secondary...
The Biot coefficient for a low permeability heterogeneous limestone
Selvadurai, A. P. S.
2018-04-01
This paper presents the experimental and theoretical developments used to estimate the Biot coefficient for the heterogeneous Cobourg Limestone, which is characterized by its very low permeability. The coefficient forms an important component of the Biot poroelastic model that is used to examine coupled hydro-mechanical and thermo-hydro-mechanical processes in the fluid-saturated Cobourg Limestone. The constraints imposed by both the heterogeneous fabric and its extremely low intact permeability [K \\in (10^{-23},10^{-20}) m2 ] require the development of alternative approaches to estimate the Biot coefficient. Large specimen bench-scale triaxial tests (150 mm diameter and 300 mm long) that account for the scale of the heterogeneous fabric are complemented by results for the volume fraction-based mineralogical composition derived from XRD measurements. The compressibility of the solid phase is based on theoretical developments proposed in the mechanics of multi-phasic elastic materials. An appeal to the theory of multi-phasic elastic solids is the only feasible approach for examining the compressibility of the solid phase. The presence of a number of mineral species necessitates the use of the theories of Voigt, Reuss and Hill along with the theories proposed by Hashin and Shtrikman for developing bounds for the compressibility of the multi-phasic geologic material composing the skeletal fabric. The analytical estimates for the Biot coefficient for the Cobourg Limestone are compared with results for similar low permeability rocks reported in the literature.
Pendulum mass affects the measurement of articular friction coefficient.
Akelman, Matthew R; Teeple, Erin; Machan, Jason T; Crisco, Joseph J; Jay, Gregory D; Fleming, Braden C
2013-02-01
Friction measurements of articular cartilage are important to determine the relative tribologic contributions made by synovial fluid or cartilage, and to assess the efficacy of therapies for preventing the development of post-traumatic osteoarthritis. Stanton's equation is the most frequently used formula for estimating the whole joint friction coefficient (μ) of an articular pendulum, and assumes pendulum energy loss through a mass-independent mechanism. This study examines if articular pendulum energy loss is indeed mass independent, and compares Stanton's model to an alternative model, which incorporates viscous damping, for calculating μ. Ten loads (25-100% body weight) were applied in a random order to an articular pendulum using the knees of adult male Hartley guinea pigs (n=4) as the fulcrum. Motion of the decaying pendulum was recorded and μ was estimated using two models: Stanton's equation, and an exponential decay function incorporating a viscous damping coefficient. μ estimates decreased as mass increased for both models. Exponential decay model fit error values were 82% less than the Stanton model. These results indicate that μ decreases with increasing mass, and that an exponential decay model provides a better fit for articular pendulum data at all mass values. In conclusion, inter-study comparisons of articular pendulum μ values should not be made without recognizing the loads used, as μ values are mass dependent. Copyright © 2012 Elsevier Ltd. All rights reserved.
Measurements of the Drag Coefficient of Simulated Micrometeoroids
DeLuca, M.; Munsat, T.; Sternovsky, Z.
2017-12-01
The dust accelerator facility operated at the University of Colorado is used to simulate meteoric ablation, including measuring the ionization efficiency over a wide range of velocities (e.g., DeLuca et al., Planet. Space Sci., submitted, 2017). This presentation reports on the most recent experimental measurements of the drag coefficient that determines the particles' slowdown from their frictional interaction with the atmosphere. The measurements indicate that meteors experience considerably more slowdown than usually assumed. The simulated meteors consisted of submicron sized aluminum particles shot into an air chamber held at 200 mTorr pressure at velocities between 1 - 10 km/s using the dust accelerator and meteor ablation facility. The slowdown is calculated from precise timing measurements made using pickup tube detectors placed upstream and near the entrance to the air chamber, and an impact detector inside the air chamber at the downstream end of the chamber. Supporting modeling calculations show that the particles have little or no mass loss during their interaction with air and thus constant radius can be assumed. Preliminary results for the drag coefficient calculated from these timing measurements reveal that the aluminum particles have a drag coefficient of 1.51 ± 0.24 in air, which is higher than typically assumed in meteoric ablation models (usually 0.5 to 1), indicating that meteors may experience more air drag than previously assumed. More detailed measurements over a wider parameter range are underway.
International Nuclear Information System (INIS)
Raynal, J.
1976-01-01
Closed formulae and recurrence relations for the transformation of a two-body harmonic oscillator wave function to the hyperspherical formalism are given. With them Moshinsky or Smirnov coefficients are obtained from the transformation coefficients of hyperspheric harmonics. For these coefficients the diagonalization method of Talman and Lande reduces to simple recurrence relations which can be used directly to compute them. New closed formulae for these coefficients are also derived: they are needed to compute the two simplest coefficients which determine the sign for the recurrence relation. (Auth.)
Friction coefficient dependence on electrostatic tribocharging
Burgo, Thiago A. L.; Silva, Cristiane A.; Balestrin, Lia B. S.; Galembeck, Fernando
2013-01-01
Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers. PMID:23934227
Revised Mark 22 coolant temperature coefficients
International Nuclear Information System (INIS)
Graves, W.E.
1987-01-01
Coolant temperature coefficients for the Mark 22 charge published previously are non-conservative because of the neglect of a significant mechanism which has a positive contribution to reactivity. Even after correcting for this effect, dynamic tests made on a Mark VIB charge in the early 60's suggest the results are still non-conservative. This memorandum takes both of these sources of information into account in making a best estimate of the prompt (coolant plus metal) temperature coefficient. Although no safety issues arise from this work (the overall temperature coefficient still strongly contributes to reactor stability), it is obviously desirable to use best estimates for prompt coefficients in limits and other calculations
Heat transfer coefficient of cryotop during freezing.
Li, W J; Zhou, X L; Wang, H S; Liu, B L; Dai, J J
2013-01-01
Cryotop is an efficient vitrification method for cryopreservation of oocytes. It has been widely used owing to its simple operation and high freezing rate. Recently, the heat transfer performance of cryotop was studied by numerical simulation in several studies. However, the range of heat transfer coefficient in the simulation is uncertain. In this study, the heat transfer coefficient for cryotop during freezing process was analyzed. The cooling rates of 40 percent ethylene glycol (EG) droplet in cryotop during freezing were measured by ultra-fast measurement system and calculated by numerical simulation at different value of heat transfer coefficient. Compared with the results obtained by two methods, the range of the heat transfer coefficient necessary for the numerical simulation of cryotop was determined, which is between 9000 W/(m(2)·K) and 10000 W/(m (2)·K).
Friction coefficient dependence on electrostatic tribocharging.
Burgo, Thiago A L; Silva, Cristiane A; Balestrin, Lia B S; Galembeck, Fernando
2013-01-01
Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers.
Roughness coefficients for stream channels in Arizona
Aldridge, B.N.; Garrett, J.M.
1973-01-01
When water flows in an open channel, energy is lost through friction along the banks and bed of the channel and through turbulence within the channel. The amount of energy lost is governed by channel roughness, which is expressed in terms of a roughness coefficient. An evaluation of the roughness coefficient is necessary in many hydraulic computations that involve flow in an open channel. Owing to the lack of satisfactory quantitative procedure, the ability of evaluate roughness coefficients can be developed only through experience; however, a basic knowledge of the methods used to assign the coefficients and the factors affecting them will be a great help. One of the most commonly used equations in open-channel hydraulics is that of Manning. The Manning equation is 1.486
Experimental techniques of conversion coefficient measurements
International Nuclear Information System (INIS)
Hamilton, J.H.
1975-01-01
Discusses briefly the history of conversion electron spectra measurements, and the interpretation of the collected data. Then provides a comprehensive review of techniques presently available to measure the conversion coefficients. (Auth.)
Explicit formulas for Clebsch-Gordan coefficients
International Nuclear Information System (INIS)
Rudnicki-Bujnowski, G.
1975-01-01
The problem is to obtain explicit algebraic formulas of Clebsch-Gordan coefficients for high values of angular momentum. The method of solution is an algebraic method based on the Racah formula using the FORMAC programming language. (Auth.)
Diffusion Coefficients of Several Aqueous Alkanolamine Solutions
Snijder, Erwin D.; Riele, Marcel J.M. te; Versteeg, Geert F.; Swaaij, W.P.M. van
1993-01-01
The Taylor dispersion technique was applied for the determination of diffusion coefficients of various systems. Experiments with the system KCl in water showed that the experimental setup provides accurate data. For the alkanolamines monoethanolamine (MEA), diethanolamine (DEA), methyldiethanolamine
Transport Coefficients from Large Deviation Functions
Directory of Open Access Journals (Sweden)
Chloe Ya Gao
2017-10-01
Full Text Available We describe a method for computing transport coefficients from the direct evaluation of large deviation functions. This method is general, relying on only equilibrium fluctuations, and is statistically efficient, employing trajectory based importance sampling. Equilibrium fluctuations of molecular currents are characterized by their large deviation functions, which are scaled cumulant generating functions analogous to the free energies. A diffusion Monte Carlo algorithm is used to evaluate the large deviation functions, from which arbitrary transport coefficients are derivable. We find significant statistical improvement over traditional Green–Kubo based calculations. The systematic and statistical errors of this method are analyzed in the context of specific transport coefficient calculations, including the shear viscosity, interfacial friction coefficient, and thermal conductivity.
Transport Coefficients from Large Deviation Functions
Gao, Chloe; Limmer, David
2017-10-01
We describe a method for computing transport coefficients from the direct evaluation of large deviation function. This method is general, relying on only equilibrium fluctuations, and is statistically efficient, employing trajectory based importance sampling. Equilibrium fluctuations of molecular currents are characterized by their large deviation functions, which is a scaled cumulant generating function analogous to the free energy. A diffusion Monte Carlo algorithm is used to evaluate the large deviation functions, from which arbitrary transport coefficients are derivable. We find significant statistical improvement over traditional Green-Kubo based calculations. The systematic and statistical errors of this method are analyzed in the context of specific transport coefficient calculations, including the shear viscosity, interfacial friction coefficient, and thermal conductivity.
A new approach to estimate Angstrom coefficients
International Nuclear Information System (INIS)
Abdel Wahab, M.
1991-09-01
A simple quadratic equation to estimate global solar radiation with coefficients depending on some physical atmospheric parameters is presented. The importance of the second order and sensitivity to some climatic variations is discussed. (author). 8 refs, 4 figs, 2 tabs
Modeling Ballasted Tracks for Runoff Coefficient C
2012-08-01
In this study, the Regional Transportation District (RTD)s light rail tracks were modeled to determine the Rational Method : runoff coefficient, C, values corresponding to ballasted tracks. To accomplish this, a laboratory study utilizing a : rain...
Relativistic neoclassical transport coefficients with momentum correction
International Nuclear Information System (INIS)
Marushchenko, I.; Azarenkov, N.A.
2016-01-01
The parallel momentum correction technique is generalized for relativistic approach. It is required for proper calculation of the parallel neoclassical flows and, in particular, for the bootstrap current at fusion temperatures. It is shown that the obtained system of linear algebraic equations for parallel fluxes can be solved directly without calculation of the distribution function if the relativistic mono-energetic transport coefficients are already known. The first relativistic correction terms for Braginskii matrix coefficients are calculated.
Torsion method for measuring piezooptic coefficients
Energy Technology Data Exchange (ETDEWEB)
Skab, I.; Smaga, I.; Savaryn, V.; Vasylkiv, Yu.; Vlokh, R. [Institute of Physical Optics, Lviv (Ukraine)
2011-01-15
We develop and describe analytically a torsion method for measuring piezooptic coefficients associated with shear stresses. It is shown that the method enables to increase significantly the accuracy of determination of piezooptic coefficients. The method and the appropriate apparatus are verified experimentally on the example of LiNbO{sub 3} crystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Measuring Resource Inequality: The Gini Coefficient
Directory of Open Access Journals (Sweden)
Michael T. Catalano
2009-07-01
Full Text Available This paper stems from work done by the authors at the Mathematics for Social Justice Workshop held in June of 2007 at Middlebury College. We provide a description of the Gini coefficient and some discussion of how it can be used to promote quantitative literacy skills in mathematics courses. The Gini Coefficient was introduced in 1921 by Italian statistician Corrado Gini as a measure of inequality. It is defined as twice the area between two curves. One, the Lorenz curve for a given population with respect to a given resource, represents the cumulative percentage of the resource as a function of the cumulative percentage of the population that shares that percentage of the resource. The second curve is the line y = x which is the Lorenz curve for a population which shares the resource equally. The Gini coefficient can be interpreted as the percentage of inequality represented in the population with respect to the given resource. We propose that the Gini coefficient can be used to enhance students’ understanding of calculus concepts and provide practice for students in using both calculus and quantitative literacy skills. Our examples are based mainly on distribution of energy resources using publicly available data from the Energy Information Agency of the United States Government. For energy resources within the United States, we find that by household, the Gini coefficient is 0.346, while using the 51 data points represented by the states and Washington D.C., the Gini coefficient is 0.158. When we consider the countries of the world as a population of 210, the Gini coefficient is 0.670. We close with ideas for questions which can be posed to students and discussion of the experiences two other mathematics instructors have had incorporating the Gini coefficient into pre-calculus-level mathematics classes.
The Binomial Coefficient for Negative Arguments
Kronenburg, M. J.
2011-01-01
The definition of the binomial coefficient in terms of gamma functions also allows non-integer arguments. For nonnegative integer arguments the gamma functions reduce to factorials, leading to the well-known Pascal triangle. Using a symmetry formula for the gamma function, this definition is extended to negative integer arguments, making the symmetry identity for binomial coefficients valid for all integer arguments. The agreement of this definition with some other identities and with the bin...
Investigation of photon attenuation coefficients for marble
International Nuclear Information System (INIS)
Basyigit, C; Akkurt, I; Kilincarslan, S; Akkurt, A
2005-01-01
The total linear attenuation coefficients μ (cm -1 ) have been obtained using the XCOM program at photon energies of 1 keV to 1 GeV for six different natural marbles produced in different places in Turkey. The individual contribution of photon interaction processes to the total linear attenuation coefficients for marble has been investigated. The calculated results were also compared with the measurements. The results obtained for marble were also compared with concrete. (note)
Analysis of flow coefficient in chair manufacture
Ivković Dragoljub; Živković Slaven
2005-01-01
The delivery on time is not possible without the good-quality planning of deadlines, i.e. planning of the manufacturing process duration. The study of flow coefficient enables the realistic forecasting of the manufacturing process duration. This paper points to the significance of the study of flow coefficient on scientific basis so as to determine the terms of the end of the manufacture of chairs made of sawn timber. Chairs are the products of complex construction, often almost completely ma...
On computing Laplace's coefficients and their derivatives.
Gerasimov, I. A.; Vinnikov, E. L.
The algorithm of computing Laplace's coefficients and their derivatives is proposed with application of recurrent relations. The A.G.M.-method is used for the calculation of values L0(0), L0(1). The FORTRAN-program corresponding to the algorithm is given. The precision control was provided with numerical integrating by Simpsons method. The behavior of Laplace's coefficients and their third derivatives whith varying indices K, n for fixed values of the α-parameter is presented graphically.
A gradient estimate for solutions to parabolic equations with discontinuous coefficients
Directory of Open Access Journals (Sweden)
Jishan Fan
2013-04-01
Full Text Available Li-Vogelius and Li-Nirenberg gave a gradient estimate for solutions of strongly elliptic equations and systems of divergence forms with piecewise smooth coefficients, respectively. The discontinuities of the coefficients are assumed to be given by manifolds of codimension 1, which we called them emph{manifolds of discontinuities}. Their gradient estimate is independent of the distances between manifolds of discontinuities. In this paper, we gave a parabolic version of their results. That is, we gave a gradient estimate for parabolic equations of divergence forms with piecewise smooth coefficients. The coefficients are assumed to be independent of time and their discontinuities are likewise the previous elliptic equations. As an application of this estimate, we also gave a pointwise gradient estimate for the fundamental solution of a parabolic operator with piecewise smooth coefficients. Both gradient estimates are independent of the distances between manifolds of discontinuities.
Drag Coefficient Estimation in Orbit Determination
McLaughlin, Craig A.; Manee, Steve; Lichtenberg, Travis
2011-07-01
Drag modeling is the greatest uncertainty in the dynamics of low Earth satellite orbits where ballistic coefficient and density errors dominate drag errors. This paper examines fitted drag coefficients found as part of a precision orbit determination process for Stella, Starlette, and the GEOSAT Follow-On satellites from 2000 to 2005. The drag coefficients for the spherical Stella and Starlette satellites are assumed to be highly correlated with density model error. The results using MSIS-86, NRLMSISE-00, and NRLMSISE-00 with dynamic calibration of the atmosphere (DCA) density corrections are compared. The DCA corrections were formulated for altitudes of 200-600 km and are found to be inappropriate when applied at 800 km. The yearly mean fitted drag coefficients are calculated for each satellite for each year studied. The yearly mean drag coefficients are higher for Starlette than Stella, where Starlette is at a higher altitude. The yearly mean fitted drag coefficients for all three satellites decrease as solar activity decreases after solar maximum.
Monitoring device for local power peaking coefficients
International Nuclear Information System (INIS)
Mihashi, Ishi
1987-01-01
Purpose: To determine and monitor the local power peaking coefficients by a method not depending on the combination of fuel types. Constitution: Representative values for the local power distribution can be obtained by determining corresponding burn-up degrees based on the burn-up degree of each of fuel assembly segments obtained in a power distribution monitor and by the interpolation and extrapolation of void coefficients. The typical values are multiplied with compensation coefficients for the control rod effect and coefficients for compensating the effect of adjacent fuel assemblies in a calculation device to obtain typical values for the present local power distribution compensated with all of the effects. Further, the calculation device compares them with typical values of the present local power distribution to obtain an aimed local power peaking coefficient as the maximum value thereof. According to the present invention, since the local power peaking coefficients can be determined not depending on the combination of the kind of fuels, if the combination of fuel assemblies is increased upon fuel change, the amount of operation therefor is not increased. (Kamimura, M.)
Monitoring device for local power peaking coefficient
International Nuclear Information System (INIS)
Mitsuhashi, Ishi
1987-01-01
Purpose: To monitor the local power peaking coefficients obtained by the method not depending on the combination of fuel types. Method: A plurality of representative values for the local power distribution determined by the nuclear constant calculation for one fuel assembly are memorized regarding each of the burn-up degree and the void coefficient on every positions and fuel types in fuel rod assemblies. While on the other hand, the representative values for the local power distribution as described above are compensated by a compensation coefficient considering the effect of adjacent segments and a control rod compensation coefficient considering the effect due to the control rod insertion relative to the just-mentioned compensation coefficient. Then, the maximum value among them is selected to determine the local power peaking coefficient at each of the times and each of the segments, which is monitored. According to this system, the calculation and the working required for the fitting work depending on the combination of fuel types are no more required at all to facilitate the maintenance as well. (Horiuchi, T.)
... the process of adapting to life after a loss. It is influenced by each person’s society, culture, and religion. Bereavement is the state of having experienced a loss. Common grief reactions Reactions to loss are called ...
Institute of Scientific and Technical Information of China (English)
Li XIE; Lihua XIE
2007-01-01
We consider the stability of a random Riccati equation with a Markovian binary jump coefficient. More specifically, we are concerned with the boundedness of the solution of a random Riccati difference equation arising from Kalman filtering with measurement losses. A sufficient condition for the peak covariance stability is obtained which has a simpler form and is shown to be less conservative in some cases than a very recent result in existing literature. Furthermore, we show that a known sufficient condition is also necessary when the observability index equals one.
Economic Loan Loss Provision and Expected Loss
Directory of Open Access Journals (Sweden)
Stefan Hlawatsch
2010-10-01
Full Text Available The intention of a loan loss provision is the anticipation of the loan's expected losses by adjusting the book value of the loan. Furthermore, this loan loss provision has to be compared to the expected loss according to Basel II and, in the case of a difference, liable equity has to be adjusted. This however assumes that the loan loss provision and the expected loss are based on a similar economic rationale, which is only valid conditionally in current loan loss provisioning methods according to IFRS. Therefore, differences between loan loss provisions and expected losses should only result from different approaches regarding the parameter estimation within each model and not due to different assumptions regarding the outcome of the model. The provisioning and accounting model developed in this paper overcomes the before-mentioned shortcomings and is consistent with an economic rationale of expected losses. Additionally, this model is based on a close-to-market valuation of the loan that is in favor of the basic idea of IFRS. Suggestions for changes in current accounting and capital requirement rules are provided.
Rational reflection coefficient and inverse scattering on the line
International Nuclear Information System (INIS)
Sabatier, P.C.
1983-01-01
Inverse scattering for the Schroedinger equation on the line is studied for reflection and transmission coefficients that satisfy the usual regularity conditions and are rational functions of k. The origin is still a particular point, but the potentials do not need to be cut at this point like in previous studies. Giving up this restriction corresponds to the existence of poles for both reflection coefficients in both upper and lower half k-planes. It is shown that the problem reduces to solving a linear algebraic system. A different algorithm, made of a sequence of Darboux-Backlund transforms, gives also the solution in closed form and enables to study separately modifications of both sides of the potential due to the introduction of poles. Thus it paves the way for approximation studies. Generalizations and particular problems will be studied in forthcoming papers
Behaviour of intermediate-level waste forms in an aqueous environment
International Nuclear Information System (INIS)
Amarantos, S.; DeBatist, R.; Brodersen, K.; Glasser, F.P.; Pottier, P.E.; Vejmelka, R.; Zamorani, E.
1985-01-01
Under Action 1 of the Second Community Programme (1980-1984), study continued of the behavoiur of low and medium activity waste matrices using 10 reference waste forms (RWFs) representative of the main waste packages produced in the Community. The aim of this paper is to outline the main results for three types of matrix: cement and derived forms, organic polymers and bitumens. The results include data on diffusion coefficients, leach rates and waste form volume changes and mass losses. They constitute a considerable advance in knowledge of confinement properties but bring to light the need for further study of radionuclide release mechanisms for the purpose of constructing long-term models of waste form behaviour in the presence of water
Directory of Open Access Journals (Sweden)
Archana Singal
2013-01-01
Full Text Available Female pattern hair loss (FPHL is a common cause of hair loss in women characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline. Its prevalence increases with advancing age and is associated with significant psychological morbidity. The pathophysiology of FPHL is still not completely understood and seems to be multifactorial. Although androgens have been implicated, the involvement of androgen-independent mechanisms is evident from frequent lack of clinical or biochemical markers of hyperandrogenism in affected women. The role of genetic polymorphisms involving the androgen and estrogen receptors is being increasingly recognized in its causation and predicting treatment response to anti-androgens. There are different clinical patterns and classifications of FPHL, knowledge of which facilitates patient management and research. Chronic telogen effluvium remains as the most important differential diagnosis. Thorough history, clinical examination, and evaluation are essential to confirm diagnosis. Patients with clinical signs of androgen excess require assessment of biochemical parameters and imaging studies. It is prudent to screen the patients for metabolic syndrome and cardiovascular risk factors. The treatment comprises medical and/or surgical modalities. Medical treatment should be initiated early as it effectively arrests hair loss progression rather than stimulating regrowth. Minoxidil continues to be the first line therapy whereas anti-androgens form the second line of treatment. The progressive nature of FPHL mandates long-term treatment for sustained effect. Medical therapy may be supplemented with cosmetic concealment in those desirous of greater hair density. Surgery may be worthwhile in some carefully selected patients.
Discharge Coefficient of Rectangular Short-Crested Weir with Varying Slope Coefficients
Directory of Open Access Journals (Sweden)
Yuejun Chen
2018-02-01
Full Text Available Rectangular short-crested weirs are widely used for simple structure and high discharge capacity. As one of the most important and influential factors of discharge capacity, side slope can improve the hydraulic characteristics of weirs at special conditions. In order to systemically study the effects of upstream and downstream slope coefficients S1 and S2 on overflow discharge coefficient in a rectangular short-crested weir the Volume of Fluid (VOF method and the Renormalization Group (RNG κ-ε turbulence model are used. In this study, the slope coefficient ranges from V to 3H:1V and each model corresponds to five total energy heads of H0 ranging from 8.0 to 24.0 cm. Comparisons of discharge coefficients and free surface profiles between simulated and laboratory results display a good agreement. The simulated results show that the difference of discharge coefficients will decrease with upstream slopes and increase with downstream slopes as H0 increases. For a given H0, the discharge coefficient has a convex parabolic relation with S1 and a piecewise linearity relation with S2. The maximum discharge coefficient is always obtained at S2 = 0.8. There exists a difference between upstream and downstream slope coefficients in the influence range of free surface curvatures. Furthermore, a proposed discharge coefficient equation by nonlinear regression is a function of upstream and downstream slope coefficients.
Directory of Open Access Journals (Sweden)
Zhong-xing Wang
2017-11-01
Full Text Available Correlation coefficient is one of the broadly use indexes in multi-criteria decision-making (MCDM processes. However, some important issues related to correlation coefficient utilization within probabilistic hesitant fuzzy environments remain to be addressed. The purpose of this study is introduced a MCDM method based on correlation coefficients utilize probabilistic hesitant fuzzy information. First, the covariance and correlation coefficient between two PHFEs is introduced, the properties of the proposed covariance and correlation coefficient are discussed. In addition, the northwest corner rule to obtain the expected mean related to the multiply of two PHFEs is introduced. Second, the weighted correlation coefficient is proposed to make the proposed MCDM method more applicable. And the properties of the proposed weighted correlation coefficient are also discussed. Finally, an illustrative example is demonstrated the practicality and effectiveness of the proposed method. An illustrative example is presented to demonstrate the correlation coefficient propose in this paper lies in the interval [−1, 1], which not only consider the strength of relationship between the PHFEs but also whether the PHFEs are positively or negatively related. The advantage of this method is it can avoid the inconsistency of the decision-making result due to the loss of information.
Lattice cell diffusion coefficients. Definitions and comparisons
International Nuclear Information System (INIS)
Hughes, R.P.
1980-01-01
Definitions of equivalent diffusion coefficients for regular lattices of heterogeneous cells have been given by several authors. The paper begins by reviewing these different definitions and the unification of their derivation. This unification makes clear how accurately each definition (together with appropriate cross-section definitions to preserve the eigenvalue) represents the individual reaction rates within the cell. The approach can be extended to include asymmetric cells and whereas before, the buckling describing the macroscopic flux shape was real, here it is found to be complex. A neutron ''drift'' coefficient as well as a diffusion coefficient is necessary to produce the macroscopic flux shape. The numerical calculation of the various different diffusion coefficients requires the solutions of equations similar to the ordinary transport equation for an infinite lattice. Traditional reactor physics codes are not sufficiently flexible to solve these equations in general. However, calculations in certain simple cases are presented and the theoretical results quantified. In difficult geometries, Monte Carlo techniques can be used to calculate an effective diffusion coefficient. These methods relate to those already described provided that correlation effects between different generations of neutrons are included. Again, these effects are quantified in certain simple cases. (author)
Experimental methodology for obtaining sound absorption coefficients
Directory of Open Access Journals (Sweden)
Carlos A. Macía M
2011-07-01
Full Text Available Objective: the authors propose a new methodology for estimating sound absorption coefficients using genetic algorithms. Methodology: sound waves are generated and conducted along a rectangular silencer. The waves are then attenuated by the absorbing material covering the silencer’s walls. The attenuated sound pressure level is used in a genetic algorithm-based search to find the parameters of the proposed attenuation expressions that include geometric factors, the wavelength and the absorption coefficient. Results: a variety of adjusted mathematical models were found that make it possible to estimate the absorption coefficients based on the characteristics of a rectangular silencer used for measuring the attenuation of the noise that passes through it. Conclusions: this methodology makes it possible to obtain the absorption coefficients of new materials in a cheap and simple manner. Although these coefficients might be slightly different from those obtained through other methodologies, they provide solutions within the engineering accuracy ranges that are used for designing noise control systems.
Radon emanation coefficients in sandy soils
International Nuclear Information System (INIS)
Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.
1998-01-01
In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)
Temporal correlation coefficient for directed networks.
Büttner, Kathrin; Salau, Jennifer; Krieter, Joachim
2016-01-01
Previous studies dealing with network theory focused mainly on the static aggregation of edges over specific time window lengths. Thus, most of the dynamic information gets lost. To assess the quality of such a static aggregation the temporal correlation coefficient can be calculated. It measures the overall possibility for an edge to persist between two consecutive snapshots. Up to now, this measure is only defined for undirected networks. Therefore, we introduce the adaption of the temporal correlation coefficient to directed networks. This new methodology enables the distinction between ingoing and outgoing edges. Besides a small example network presenting the single calculation steps, we also calculated the proposed measurements for a real pig trade network to emphasize the importance of considering the edge direction. The farm types at the beginning of the pork supply chain showed clearly higher values for the outgoing temporal correlation coefficient compared to the farm types at the end of the pork supply chain. These farm types showed higher values for the ingoing temporal correlation coefficient. The temporal correlation coefficient is a valuable tool to understand the structural dynamics of these systems, as it assesses the consistency of the edge configuration. The adaption of this measure for directed networks may help to preserve meaningful additional information about the investigated network that might get lost if the edge directions are ignored.
Computation of Clebsch-Gordan and Gaunt coefficients using binomial coefficients
International Nuclear Information System (INIS)
Guseinov, I.I.; Oezmen, A.; Atav, Ue
1995-01-01
Using binomial coefficients the Clebsch-Gordan and Gaunt coefficients were calculated for extremely large quantum numbers. The main advantage of this approach is directly calculating these coefficients, instead of using recursion relations. Accuracy of the results is quite high for quantum numbers l 1 , and l 2 up to 100. Despite direct calculation, the CPU times are found comparable with those given in the related literature. 11 refs., 1 fig., 2 tabs
Teammates and social influence affect weight loss outcomes in a team-based weight loss competition.
Leahey, Tricia M; Kumar, Rajiv; Weinberg, Brad M; Wing, Rena R
2012-07-01
Team-based internet interventions are increasing in popularity as a way of promoting weight loss in large numbers of individuals. Given that social networks influence health behavior change, this study investigated the effects of teammates and social influence on individual weight loss during a team-based weight loss competition. Shape Up Rhode Island (SURI) 2009 was a 12-week online program open to adult residents of Rhode Island. Participants joined with a team and competed with other teams on weight loss and/or physical activity. Overweight/obese (OW/OB) individuals (N = 3,330; 76% female; age = 46.1 ± 10.8; BMI = 31.2 ± 5.3 kg/m(2)), representing 987 teams, completed the weight loss program. Multilevel modeling was used to examine whether weight loss clustered among teammates and whether percentage of teammates in the weight loss division and reported teammate influence on weight loss were associated with individual weight outcomes. OW/OB completers reported losing 4.2 ± 3.4% of initial body weight. Weight loss was similar among teammates (intraclass correlation coefficient (ICC) = 0.10, P social influence for weight loss were associated with greater percent weight loss (P's ≤ 0.002). Similarly, achieving a clinically significant (5%) weight loss tended to cluster within teams (ICC = 0.09; P social influence for weight loss were associated with increased likelihood of achieving a 5% weight loss (odds ratio (OR) = 1.06; OR = 1.20, respectively). These results suggest that teammates affect weight loss outcomes during a team-based intervention. Harnessing and maximizing teammate influence for weight loss may enhance weight outcomes in large-scale team-based programs.
Curvature of Indoor Sensor Network: Clustering Coefficient
Directory of Open Access Journals (Sweden)
2009-03-01
Full Text Available We investigate the geometric properties of the communication graph in realistic low-power wireless networks. In particular, we explore the concept of the curvature of a wireless network via the clustering coefficient. Clustering coefficient analysis is a computationally simplified, semilocal approach, which nevertheless captures such a large-scale feature as congestion in the underlying network. The clustering coefficient concept is applied to three cases of indoor sensor networks, under varying thresholds on the link packet reception rate (PRR. A transition from positive curvature (“meshed” network to negative curvature (“core concentric” network is observed by increasing the threshold. Even though this paper deals with network curvature per se, we nevertheless expand on the underlying congestion motivation, propose several new concepts (network inertia and centroid, and finally we argue that greedy routing on a virtual positively curved network achieves load balancing on the physical network.
Estimating Runoff Coefficients Using Weather Radars
DEFF Research Database (Denmark)
Ahm, Malte; Thorndahl, Søren Liedtke; Rasmussen, Michael R.
2012-01-01
This paper presents a method for estimating runoff coefficients of urban drainage catchments based on a combination of high resolution weather radar data and insewer flow measurements. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients...... of separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678ha) located in the municipality of Aarhus, Denmark. The study has proven it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and runoff...... measurements to identify the runoff coefficients at subcatchment level. The number of potential subcatchments is limited by the number of available rainfall events with a sufficient spatial variability....
Experimental determination of fission gas adsorption coefficients
International Nuclear Information System (INIS)
Lovell, R.; Underhill, D.W.
1979-01-01
Large charcoal beds have been used for a number of years for the holdup and decay of radioactive isotopes of krypton and xenon. Reliable design of these beds depends on an accurate knowledge of the adsorption coefficient of krypton and xenon on the adsorbents used in these beds. It is somewhat surprising that there is no standard procedure of determining the adsorption coefficient for krypton and xenon. Fundamental information needed to establish a standardized reproducible test procedure is given emphasizing the breakthrough curves commonly used to analyze dynamic adsorption data can lead to serious systematic errors and the fact that the adsorption coefficient, if calculated from the arithmetic holding time, is independent of geometric factors such as the shape of the adsorption bed and the irregular shape of the adsorbent
Ideal related K-theory with coefficients
DEFF Research Database (Denmark)
Eilers, Soren; Restorff, Gunnar; Ruiz, Efren
2017-01-01
In this paper, we define an invariant, which we believe should be the substitute for total K-theory in the case when there is one distinguished ideal. Moreover, some diagrams relating the new groups to the ordinary K-groups with coefficients are constructed. These diagrams will in most cases help...... to determine the new groups, and will in a companion paper be used to prove a universal multi-coefficient theorem for the one distinguished ideal case for a large class of algebras......In this paper, we define an invariant, which we believe should be the substitute for total K-theory in the case when there is one distinguished ideal. Moreover, some diagrams relating the new groups to the ordinary K-groups with coefficients are constructed. These diagrams will in most cases help...
Nozzle geometry variations on the discharge coefficient
Directory of Open Access Journals (Sweden)
M.M.A. Alam
2016-03-01
Full Text Available Numerical works have been conducted to investigate the effect of nozzle geometries on the discharge coefficient. Several contoured converging nozzles with finite radius of curvatures, conically converging nozzles and conical divergent orifices have been employed in this investigation. Each nozzle and orifice has a nominal exit diameter of 12.7×10−3 m. A 3rd order MUSCL finite volume method of ANSYS Fluent 13.0 was used to solve the Reynolds-averaged Navier–Stokes equations in simulating turbulent flows through various nozzle inlet geometries. The numerical model was validated through comparison between the numerical results and experimental data. The results obtained show that the nozzle geometry has pronounced effect on the sonic lines and discharge coefficients. The coefficient of discharge was found differ from unity due to the non-uniformity of flow parameters at the nozzle exit and the presence of boundary layer as well.
Photographic guidance for selecting flow resistance coefficients in high-gradient channels
Steven E. Yochum; Francesco Comiti; Ellen Wohl; Gabrielle C. L. David; Luca Mao
2014-01-01
Photographic guidance is presented to assist with the estimation of Manning’s n and Darcy-Weisbach f in high-gradient plane-bed, step-pool, and cascade channels. Reaches both with and without instream wood are included. These coefficients are necessary for the estimation of reachaverage velocity, energy loss, and...
International Nuclear Information System (INIS)
Tsuji, Masashi; Aoki, Yukinori; Shimazu, Yoichiro; Yamasaki, Masatoshi; Hanayama, Yasushi
2006-01-01
A method to evaluate the moderator coefficient (MTC) and the Doppler coefficient through experimental procedures performed during reactor physics tests of PWR power plants is proposed. This method combines isothermal temperature coefficient (ITC) measurement experiments and reactor power transient experiments at low power conditions for dynamic identification. In the dynamic identification, either one of temperature coefficients can be determined in such a way that frequency response characteristics of the reactivity change observed by a digital reactivity meter is reproduced from measured data of neutron count rate and the average coolant temperature. The other unknown coefficient can also be determined by subtracting the coefficient obtained from the dynamic identification from ITC. As the proposed method can directly estimate the Doppler coefficient, the applicability of the conventional core design codes to predict the Doppler coefficient can be verified for new types of fuels such as mixed oxide fuels. The digital simulation study was carried out to show the feasibility of the proposed method. The numerical analysis showed that the MTC and the Doppler coefficient can be estimated accurately and even if there are uncertainties in the parameters of the reactor kinetics model, the accuracies of the estimated values are not seriously impaired. (author)
Criterions for fixing regulatory seismic acceleration coefficients
International Nuclear Information System (INIS)
Costes, D.
1988-03-01
Acceleration coeffficients to be taken into account in seismic areas for calculation of structures are defined in national seismic regulations. Joined to the described qualitative requirements, these coefficients represent a balance between precaution costs and avoided damages, both in terms of material repairing costs and damage to human life. Persons in charge of fixing these coefficients must be informed of corresponding quantitative aspects. Data on seismic motions occurrencies and consequences are gathered here and convoluted to mean damage evaluations. Indications on precaution costs are joined, which shows that currently recommended levels of seismic motions are high relatively to financial profitability, and represent in fact an aethical choice about human life value [fr
Diffusion and transport coefficients in synthetic opals
International Nuclear Information System (INIS)
Sofo, J. O.; Mahan, G. D.
2000-01-01
Opals are structures composed of close-packed spheres in the size range of nano to micrometers. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the thermal and electrical conductivity is used to estimate the transport coefficients of opal structures as a function of the neck size and the mean free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures. (c) 2000 The American Physical Society
A Simple Measure of Price Adjustment Coefficients.
Damodaran, Aswath
1993-01-01
One measure of market efficiency is the speed with which prices adjust to new information. The author develops a simple approach to estimating these price adjustment coefficients by using the information in return processes. This approach is used to estimate t he price adjustment coefficients for firms listed on the NYSE and the A MEX as well as for over-the-counter stocks. The author finds evidence of a lagged adjustment to new information in shorter return intervals for firms in all market ...
Absorption coefficient instrument for turbid natural waters
Friedman, E.; Cherdak, A.; Poole, L.; Houghton, W.
1980-01-01
The paper presents an instrument that directly measures multispectral absorption coefficient of turbid natural water. Attention is given to the design, which is shown to incorporate methods for the compensation of variation in the internal light source intensity, correction of the spectrally dependent nature of the optical elements, and correction for variation in the background light level. In addition, when used in conjunction with a spectrally matched total attenuation instrument, the spectrally dependent scattering coefficient can also be derived. Finally, it is reported that systematic errors associated with multiple scattering have been estimated using Monte Carlo techniques.
Transfer of risk coefficients across populations
International Nuclear Information System (INIS)
Rasmussen, L.R.
1992-01-01
The variation of lifetime risk projections for a Canadian population caused by the uncertainty in the choice of method for transferring excess relative risk coefficients between populations is assessed. Site-specific projections, varied by factors up to 3.5 when excess risk coefficients of the BEIR V relative risk models were transferred to the Canadian population using an additive and multiplicative method. When the risk from all cancers are combined, differences between transfer methods were no longer significant. The Canadian projections were consistent with the ICRP-60 nominal fatal cancer risk estimates. (author)
Reaction rate calculations via transmission coefficients
International Nuclear Information System (INIS)
Feit, M.D.; Alder, B.J.
1985-01-01
The transmission coefficient of a wavepacket traversing a potential barrier can be determined by steady state calculations carried out in imaginary time instead of by real time dynamical calculations. The general argument is verified for the Eckart barrier potential by a comparison of transmission coefficients calculated from real and imaginary time solutions of the Schroedinger equation. The correspondence demonstrated here allows a formulation for the reaction rate that avoids difficulties due to both rare events and explicitly time dependent calculations. 5 refs., 2 figs
Dependence of sputtering coefficient on ion dose
International Nuclear Information System (INIS)
Colligon, J.S.; Patel, M.H.
1977-01-01
The sputtering coefficient of polycrystalline gold bombarded by 10-40 keV Ar + ions had been measured as a function of total ion dose and shown to exhibit oscillations in magnitude between 30 and 100%. Possible experimental errors which would give rise to such an oscillation have been considered, but it is apparent that these factors are unable to explain the measurements. It is proposed that a change in the Sublimation Energy associated with either bulk damage or formation of surface topographical features arising during ion bombardment may be responsible for the observed variations in sputtering coefficient. (author)
ANL results for LMFR reactivity coefficients benchmark
International Nuclear Information System (INIS)
Hill, Robert
2000-01-01
The fast reactor analysis methods developed at ANL were extensively tested in ZPR and ZPPR experiments, applied to EBR-2 and FFTF test reactors. The basic nuclear data library used was ENDF/B-V.2 with the ETOE-2 data processing code and the ENDF/B-VI. Multigroup constants were generated by Monte Carlo code MCNP 2 -2. Neutron flux calculation were done by DIF3D code applying neutron diffusion theory and finite difference method. The results obtained include basic parameters; fuel and structure regional Doppler coefficients; geometry expansion fuel coefficients; kinetics parameters. In general, agreement between phase 1 and 2 results were excellent
Directory of Open Access Journals (Sweden)
Chief Editor
2014-09-01
to produce preprints or reprints and translate into languages other than English for sale or free distribution; and 4 the right to republish the work in a collection of articles in any other mechanical or electronic format. We give the rights to the corresponding author to make necessary changes as per the request of the journal, do the rest of the correspondence on our behalf and he/she will act as the guarantor for the manuscript on our behalf. All persons who have made substantial contributions to the work reported in the manuscript, but who are not contributors, are named in the Acknowledgment and have given me/us their written permission to be named. If I/we do not include an Acknowledgment that means I/we have not received substantial contributions from non-contributors and no contributor has been omitted.S NoAuthors' NamesContribution (IJCME Guidelines{1 substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; 2 drafting the article or revising it critically for important intellectual content; and 3 final approval of the version to be published. Authors should meet conditions 1, 2, and 3}.SignatureDate Note: All the authors are required to sign independently in this form in the sequence given above. In case an author has left the institution/country and whose whereabouts are not known, the senior author may sign on his/her behalf taking the responsibility.No addition/deletion/ or any change in the sequence of the authorship will be permissible at a later stage, without valid reasons and permission of the Editor.If the authorship is contested at any stage, the article will be either returned or will not be processed for publication till the issue is solved.Maximum up to 4 authors for short communication and up to 6 authors for original article.
Directory of Open Access Journals (Sweden)
Chief Editor
2016-06-01
to produce preprints or reprints and translate into languages other than English for sale or free distribution; and 4 the right to republish the work in a collection of articles in any other mechanical or electronic format. We give the rights to the corresponding author to make necessary changes as per the request of the journal, do the rest of the correspondence on our behalf and he/she will act as the guarantor for the manuscript on our behalf. All persons who have made substantial contributions to the work reported in the manuscript, but who are not contributors, are named in the Acknowledgment and have given me/us their written permission to be named. If I/we do not include an Acknowledgment that means I/we have not received substantial contributions from non-contributors and no contributor has been omitted.S NoAuthors' NamesContribution (IJCME Guidelines{1 substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; 2 drafting the article or revising it critically for important intellectual content; and 3 final approval of the version to be published. Authors should meet conditions 1, 2, and 3}.SignatureDate Note: All the authors are required to sign independently in this form in the sequence given above. In case an author has left the institution/country and whose whereabouts are not known, the senior author may sign on his/her behalf taking the responsibility.No addition/deletion/ or any change in the sequence of the authorship will be permissible at a later stage, without valid reasons and permission of the Editor.If the authorship is contested at any stage, the article will be either returned or will not be processed for publication till the issue is solved.Maximum up to 4 authors for short communication and up to 6 authors for original article.
Algebra and Arithmetic of Modular Forms
DEFF Research Database (Denmark)
Rustom, Nadim
In [Rus14b] and [Rus14a], we study graded rings of modular forms over congruence subgroups, with coefficients in subrings A of C, and determine bounds of the weights of modular forms constituting a minimal set of generators, as well as on the degree of the generators of the ideal of relations...... between them. We give an algorithm that computes the structures of these rings, and formulate conjectures on the minimal generating weight for modular forms with coefficients in Z. We discuss questions of finiteness of systems of Hecke eigenvalues modulo pm, for a prime p and an integer m ≥ 2, in analogy...
NNLO splitting and coefficient functions with time-like kinematics
International Nuclear Information System (INIS)
Mitov, A.; Moch, S.; Vogt, A.; Liverpool Univ.
2006-09-01
We discuss recent results on the three-loop (next-to-next-to-leading order, NNLO) time-like splitting functions of QCD and the two-loop (NNLO) coefficient functions in one-particle inclusive e + e - -annihilation. These results form the basis for extracting fragmentation functions for light and heavy flavors with NNLO accuracy that will be needed at the LHC and ILC. The two-loop calculations have been performed in Mellin space bases on a new method, the main features of which we also describe briefly. (orig.)
Nuclear data propagation with burnup. Impact on SFR reactivity coefficients
International Nuclear Information System (INIS)
Buiron, Laurent; Plisson-Rieunier, Daniele
2017-01-01
For the next generation fast reactor design, the Generation IV International Forum (GIF) defined global objectives in terms of safety improvement, sustainability, waste minimization and non-proliferation. Among the possibilities studied at CEA, Sodium cooled Fast Reactor (SFR) are studied as potential industrial tools for next decade's deployment. Many efforts have been made in the last years to obtain advanced industrial core designs that comply with these goals. Concerning safety issues, particular efforts have been made in order to obtain core designs that can be resilient to accidental transients. The 'safety' level of such new designs is often characterized by their 'natural' behavior under unprotected transients such as loss of flow or hypothetical transient over power. Transient analysis needs several accurate neutronic input data such as reactivity coefficient and kinetic parameters. Beside estimation of the level of 'absolute' values, associated uncertainties have also to be evaluated for the whole set of relevant data. These estimations have to be performed for different core state such as end of cycle core for feedback coefficient. This means that uncertainties have to be obtained not only a fixed time but also have to be propagated all through irradiation. To do so, we need to couple Boltzman and Bateman equations at sensitivities level. The coupling process could be done with the help of the perturbation theory which gives adapted framework suited for deterministic calculation codes. This coupling is currently in progress in ERANOS code system. The actual implementation gives access to estimation of sensitivities for both reactivity coefficients and mass balance. After a brief theoretical description of Boltzman/Bateman coupling capabilities in ERANOS, the study presented in this paper focuses on sensitivity and uncertainties estimation for the main feedback coefficients involved in fast reactor transients: the
Lateral dispersion coefficients as functions of averaging time
International Nuclear Information System (INIS)
Sheih, C.M.
1980-01-01
Plume dispersion coefficients are discussed in terms of single-particle and relative diffusion, and are investigated as functions of averaging time. To demonstrate the effects of averaging time on the relative importance of various dispersion processes, and observed lateral wind velocity spectrum is used to compute the lateral dispersion coefficients of total, single-particle and relative diffusion for various averaging times and plume travel times. The results indicate that for a 1 h averaging time the dispersion coefficient of a plume can be approximated by single-particle diffusion alone for travel times <250 s and by relative diffusion for longer travel times. Furthermore, it is shown that the power-law formula suggested by Turner for relating pollutant concentrations for other averaging times to the corresponding 15 min average is applicable to the present example only when the averaging time is less than 200 s and the tral time smaller than about 300 s. Since the turbulence spectrum used in the analysis is an observed one, it is hoped that the results could represent many conditions encountered in the atmosphere. However, as the results depend on the form of turbulence spectrum, the calculations are not for deriving a set of specific criteria but for demonstrating the need in discriminating various processes in studies of plume dispersion
Determination of entrance loss coefficients for pre-cast reinforced concrete box culverts.
2012-12-01
There is an increased interest in constructing Pre-Cast (PC) Twin and Triple Reinforced Concrete Box (RCB) culverts : in Iowa due to the efficiency associated with their production in controlled environment and decrease of the construction : time at ...
Manukovsky, N. S.; Kovalev, V. S.; Somova, L. A.
Biological life support systems (BLSS) of various coefficients of closure were considered The basic coefficient of closure was accepted equal to 66%. With increase in coefficient of closure food requirements for the greater degree should be satisfied due to the manufacture of food inside the BLSS. In this connection food values were estimated both in the basic variant, and in those with increased coefficients of closure. Metabolic massflow rates were estimated at the input and output of the BLSS as well as inside it. Human massflow rates were submitted on the basis of characteristics of the 'reference man'. Stoichiometric synthesis - degradation equations of organic substances in the BLSS were obtained. A problem of nitrogen imbalance was shown to occur under an incomplete BLSS closure. To compensate losses of nitrogen with urine and feces, food and nitrogen-containing additives should be introduced into the BLSS.
Correlation Coefficients of Extended Hesitant Fuzzy Sets and Their Applications to Decision Making
Directory of Open Access Journals (Sweden)
Na Lu
2017-03-01
Full Text Available Extended hesitant fuzzy sets (EHFSs, which allow the membership degree of an element to a set represented by several possible value-groups, can be considered as a powerful tool to express uncertain information in the process of group decision making. Therefore, we derive some correlation coefficients between EHFSs, which contain two cases, the correlation coefficients taking into account the length of extended hesitant fuzzy elements (EHFEs and the correlation coefficients without taking into account the length of EHFEs, as a new extension of existing correlation coefficients for hesitant fuzzy sets (HFSs and apply them to decision making under extended hesitant fuzzy environments. A real-world example based on the energy policy problem is employed to illustrate the actual need for dealing with the difference of evaluation information provided by different experts without information loss in decision making processes.
Friction Coefficient Determination by Electrical Resistance Measurements
Tunyagi, A.; Kandrai, K.; Fülöp, Z.; Kapusi, Z.; Simon, A.
2018-01-01
A simple and low-cost, DIY-type, Arduino-driven experiment is presented for the study of friction and measurement of the friction coefficient, using a conductive rubber cord as a force sensor. It is proposed for high-school or college/university-level students. We strongly believe that it is worthwhile planning, designing and performing Arduino…
Bayesian Meta-Analysis of Coefficient Alpha
Brannick, Michael T.; Zhang, Nanhua
2013-01-01
The current paper describes and illustrates a Bayesian approach to the meta-analysis of coefficient alpha. Alpha is the most commonly used estimate of the reliability or consistency (freedom from measurement error) for educational and psychological measures. The conventional approach to meta-analysis uses inverse variance weights to combine…
Tracking time-varying coefficient-functions
DEFF Research Database (Denmark)
Nielsen, Henrik Aalborg; Nielsen, Torben Skov; Joensen, Alfred K.
2000-01-01
is a combination of recursive least squares with exponential forgetting and local polynomial regression. It is argued, that it is appropriate to let the forgetting factor vary with the value of the external signal which is the argument of the coefficient functions. Some of the key properties of the modified method...... are studied by simulation...
On finding algebraic expressions for genealogical coefficients
International Nuclear Information System (INIS)
Kanyauskas, J.M.; Shimonis, V.Ch.; Rudzikas, Z.B.
1979-01-01
It has been attempted to obtain analytical expressions for genealogical coefficients with one detached electron in the case of L-S coupling. A method of second quantization and tensorial properties of the quasi-spin operator are applied. It is restricted to the states for the classification of which the seigniority quantum number v is sufficient. Three ways of the acquirement of these expressions are discussed: 1. In the recurrent way wave functions of N and N-1 electrons are built, consequently expressing these functions in terms of the creation-annihilation operators. 2. Recurrent summation with the use of evident, simple genealogical coefficients. 3. Using the ratios, connecting the genealogical coefficients with the normalized multiplier. The data are presented in formulae and discussions. The generalization of the Redmond's formula is obtained and relatively simple algebraic expressions of the genealogical coefficients of the equivalent electron configurations, for the distinction of the recurrent terms of which introduction of the seigniority quantum number v is sufficient, are given
Power coefficient anomaly in Joyo, (2)
International Nuclear Information System (INIS)
Ishikawa, Makoto; Yamashita, Yoshioki; Sasaki, Makoto; Nara, Yoshihiko.
1981-12-01
In this report, the presumption about the mechanism having caused the power coefficient anomaly in Joyo during the 75 MW power-raising test in 1979 is described. After the previous report, the new information about the results of the post-irradiation examination and the analysis of the power coefficient of Joyo were able to be obtained. From these information, the mechanism of causing the anomaly was presumed as follows. In 50 MW operation, the fuel burnup reached about 10,000 MWD/ton at the end of second cycle, and produced fission gas was almost retained in fuel pellets. When the power was raised from 50 MW to 75 MW for the first time, the fission gas began to be released when 50 MW was somewhat exceeded. The fission gas release caused the temperature rise and cracking of fuel pellets, and elongated fuel stack length abruptly. These phenomena induced to enlarge the fuel expansion reactivity effect and Doppler reactivity effect, and caused the anomalous behavior of power coefficient. After reaching 75 MW, the fuel stack length did not respond normally to reactor power change, and the magnitude of power coefficient became smaller. The reactivity was lost considerably from the core after the anomaly. (Kako, I.)
Problems on Divisibility of Binomial Coefficients
Osler, Thomas J.; Smoak, James
2004-01-01
Twelve unusual problems involving divisibility of the binomial coefficients are represented in this article. The problems are listed in "The Problems" section. All twelve problems have short solutions which are listed in "The Solutions" section. These problems could be assigned to students in any course in which the binomial theorem and Pascal's…
Effective stress coefficient for uniaxial strain condition
DEFF Research Database (Denmark)
Alam, M.M.; Fabricius, I.L.
2012-01-01
one dimensional rock mechanical deformation. We further investigated the effect of boundary condition on the stress dependency of effective stress coefficient and discussed its application in reservoir study. As stress field in the reservoirs are most unlikely to be hydrostatic, effective stress...... determined under uniaxial strain condition will be more relevant in reservoir studies. Copyright 2012 ARMA, American Rock Mechanics Association....
Molecular Diffusion Coefficients: Experimental Determination and Demonstration.
Fate, Gwendolyn; Lynn, David G.
1990-01-01
Presented are laboratory methods which allow the demonstration and determination of the diffusion coefficients of compounds ranging in size from water to small proteins. Included are the procedures involving the use of a spectrometer, UV cell, triterated agar, and oxygen diffusion. Results including quantification are described. (CW)
Absorption coefficients of silicon: A theoretical treatment
Tsai, Chin-Yi
2018-05-01
A theoretical model with explicit formulas for calculating the optical absorption and gain coefficients of silicon is presented. It incorporates direct and indirect interband transitions and considers the effects of occupied/unoccupied carrier states. The indirect interband transition is calculated from the second-order time-independent perturbation theory of quantum mechanics by incorporating all eight possible routes of absorption or emission of photons and phonons. Absorption coefficients of silicon are calculated from these formulas. The agreements and discrepancies among the calculated results, the Rajkanan-Singh-Shewchun (RSS) formula, and Green's data are investigated and discussed. For example, the RSS formula tends to overestimate the contributions of indirect transitions for cases with high photon energy. The results show that the state occupied/unoccupied effect is almost negligible for silicon absorption coefficients up to the onset of the optical gain condition where the energy separation of Quasi-Femi levels between electrons and holes is larger than the band-gap energy. The usefulness of using the physics-based formulas, rather than semi-empirical fitting ones, for absorption coefficients in theoretical studies of photovoltaic devices is also discussed.
Control in the coefficients with variational crimes
DEFF Research Database (Denmark)
Evgrafov, Anton; Marhadi, Kun Saptohartyadi
2012-01-01
We study convergence of discontinuous Galerkin-type discretizations of the problems of control in the coefficients of uniformly elliptic partial differential equations (PDEs). As a model problem we use that of the optimal design of thin (Kirchhoff) plates, where the governing equations...
Coefficient Omega Bootstrap Confidence Intervals: Nonnormal Distributions
Padilla, Miguel A.; Divers, Jasmin
2013-01-01
The performance of the normal theory bootstrap (NTB), the percentile bootstrap (PB), and the bias-corrected and accelerated (BCa) bootstrap confidence intervals (CIs) for coefficient omega was assessed through a Monte Carlo simulation under conditions not previously investigated. Of particular interests were nonnormal Likert-type and binary items.…
Activity risk coefficients for living generations
International Nuclear Information System (INIS)
Raicevic, J.; Merkle, M.; Ninkovic, M. M.
1993-01-01
This paper deals with the new concept of the Activity risk coefficients, ARCs, which are in Probabilistic risk assessment PRA computer codes used for the calculation of the stochastic effects due to low dose exposures. As an example, ARC expressions for the Cloudshine is derived. (author)
Rate coefficient for the reaction N + NO
Fox, J. L.
1994-01-01
Evidence has been advanced that the rate coefficient for the reaction N + NO right arrow N2 + O has a small positive temperature dependence at the high temperatures (900 to 1500 K) that prevail in the terrestrial middle and upper thermosphere by Siskind and Rusch (1992), and at the low temperatures (100 to 200 K) of the Martian lower thermosphere by Fox (1993). Assuming that the rate coefficient recommended by the Jet Propulsion Laboratory evaluation (DeMore et al., 1992) is accurate at 300 K, we derive here the low temperature value of the activation energy for this reaction and thus the rate coefficient that best fits the Viking 1 measured NO densities. We find that the fit is acceptable for a rate coefficient of about 1.3 x 10(exp -10)(T/300)(exp 0.5)exp(-400/T) and better for a value of about 2.5 x 10(exp -10)(T/300)(exp 0.5)exp(-600/T)cu cm/s.
The Evolution of Pearson's Correlation Coefficient
Kader, Gary D.; Franklin, Christine A.
2008-01-01
This article describes an activity for developing the notion of association between two quantitative variables. By exploring a collection of scatter plots, the authors propose a nonstandard "intuitive" measure of association; and by examining properties of this measure, they develop the more standard measure, Pearson's Correlation Coefficient. The…
Probability based calibration of pressure coefficients
DEFF Research Database (Denmark)
Hansen, Svend Ole; Pedersen, Marie Louise; Sørensen, John Dalsgaard
2015-01-01
Normally, a consistent basis for calculating partial factors focuses on a homogeneous reliability index neither depending on which material the structure is constructed of nor the ratio between the permanent and variable actions acting on the structure. Furthermore, the reliability index should n...... the characteristic shape coefficients are based on mean values as specified in background documents to the Eurocodes. Importance of hidden safeties judging the reliability is discussed for wind actions on low-rise structures....... not depend on the type of variable action. A probability based calibration of pressure coefficients have been carried out using pressure measurements on the standard CAARC building modelled on scale of 1:383. The extreme pressures measured on the CAARC building model in the wind tunnel have been fitted.......3, the Eurocode partial factor of 1.5 for variable actions agrees well with the inherent uncertainties of wind actions when the pressure coefficients are determined using wind tunnel test results. The increased bias and uncertainty when pressure coefficients mainly are based on structural codes lead to a larger...
Correlation Coefficients: Appropriate Use and Interpretation.
Schober, Patrick; Boer, Christa; Schwarte, Lothar A
2018-05-01
Correlation in the broadest sense is a measure of an association between variables. In correlated data, the change in the magnitude of 1 variable is associated with a change in the magnitude of another variable, either in the same (positive correlation) or in the opposite (negative correlation) direction. Most often, the term correlation is used in the context of a linear relationship between 2 continuous variables and expressed as Pearson product-moment correlation. The Pearson correlation coefficient is typically used for jointly normally distributed data (data that follow a bivariate normal distribution). For nonnormally distributed continuous data, for ordinal data, or for data with relevant outliers, a Spearman rank correlation can be used as a measure of a monotonic association. Both correlation coefficients are scaled such that they range from -1 to +1, where 0 indicates that there is no linear or monotonic association, and the relationship gets stronger and ultimately approaches a straight line (Pearson correlation) or a constantly increasing or decreasing curve (Spearman correlation) as the coefficient approaches an absolute value of 1. Hypothesis tests and confidence intervals can be used to address the statistical significance of the results and to estimate the strength of the relationship in the population from which the data were sampled. The aim of this tutorial is to guide researchers and clinicians in the appropriate use and interpretation of correlation coefficients.
Modelling of power-reactivity coefficient measurement
International Nuclear Information System (INIS)
Strmensky, C.; Petenyi, V.; Jagrik, J.; Minarcin, M.; Hascik, R.; Toth, L.
2005-01-01
Report describes results of modeling of power-reactivity coefficient analysis on power-level. In paper we calculate values of discrepancies arisen during transient process. These discrepancies can be arisen as result of experiment evaluation and can be caused by disregard of 3D effects on neutron distribution. The results are critically discussed (Authors)
Directory of Open Access Journals (Sweden)
Tibary A
2015-12-01
Full Text Available Pregnancy loss is an important aspect of equine practice due to the economic and emotional loss that it engenders. Pregnancy loss is often divided in two categories: early pregnancy loss (EPL or embryonic death (ED (first 42 days and fetal losses (after 42 days. Diagnosis of the causes of pregnancy loss is often very challenging. Many of the causes of EPL remain poorly documented but studies on embryo development and embryo-uterine interaction have been able to shed some light on predisposing factors. Fetal losses or abortions are dominated by infectious causes and particularly bacterial placentitis. Detailed reviews of pregnancy loss were recently published by the authors (Tibary et al., 2012; Tibary and Pearson, 2012; Tibary et al., 2014. The objective of this paper is to provide an overview of the epidemiology, etiology, diagnosis and prevention of pregnancy loss in the mare.
Social impacts of the work loss in cancer survivors.
Yamauchi, Hideko; Nakagawa, Chizuko; Fukuda, Takashi
2017-09-01
As cancer frequently occurs during the most productive years of life, our purpose was to estimate the cost of work loss of cancer survivors and develop interventions to minimize the loss. We estimated the cost of the work loss from all cancers resulting from patients' inpatient, outpatient, and non-treatment days. This was calculated with a new method, the product of the "employment rate coefficient × productivity coefficient," making use of data published by the Japanese Ministries. The estimate of work loss on treatment days for all cancers was $1820.21 million in men and $939.38 million in women. In terms of disease classification, lung cancer was the largest cause in men, whereas breast cancer was the largest in women. On non-treatment days, the work losses because of gastric, colon, and lung cancers were large in men, while breast cancer was the largest in women and in total. The estimated loss for all cancers was $3685.506 million in men and $2502.565 million in women, when the product was assumed 0.5. In Japan, breast cancer was considered the leading cause for cost of work loss, and the most influential cause when the product of the "employment rate coefficient × productivity coefficient" for breast cancer was assumed the same as the product for all other types of cancers. It is necessary to establish support systems for working cancer survivors.
DEFF Research Database (Denmark)
Jeong, Cheol-Ho; Chang, Ji-ho
2015-01-01
largely depending on the test room. Several conversion methods for porous absorbers from the Sabine absorption coefficient to the random incidence absorption coefficient were suggested by considering the finite size of a test specimen and non-uniformly incident energy onto the specimen, which turned out...... resistivity optimization outperforms the surface impedance optimization in terms of the reproducibility....
Validation of moderator-level reactivity coefficient using station data
Energy Technology Data Exchange (ETDEWEB)
Younis, M.; Martchouk, I., E-mail: mohamed.younis@amecfw.com, E-mail: iouri.martchouk@amecfw.com [Amec Foster Wheeler, Toronto, ON (Canada); Buchan, P.D., E-mail: david.buchan@opg.com [Ontario Power Generation, Pickering, ON (Canada)
2015-07-01
The reactivity effect due to variations in the moderator level has been recognized as a reactor physics phenomenon of importance during normal operation and accident analysis. The moderator-level reactivity coefficient is an important parameter in safety analysis of CANDU reactors, e.g., during Loss of Moderator Heat Sink as well as in the simulation of Reactor Regulating System action in CANDU reactors that use moderator level for reactivity control. This paper presents the results of the validation exercise of the reactor-physics toolset using the measurements performed in Pickering Unit 4 in 2003. The capability of the code suite of predicting moderator-level reactivity effect was tested by comparing measured and predicted reactor-physics parameters. (author)
Ilia Anisa, Nor; Azian, Noor; Sharizan, Mohd; Iwai, Yoshio
2014-04-01
6-gingerol and 6-shogaol are the main constituents as anti-inflammatory or bioactive compounds from zingiber officinale Roscoe. These bioactive compounds have been proven for inflammatory disease, antioxidatives and anticancer. The effect of temperature on diffusion coefficient for 6-gingerol and 6-shogaol were studied in subcritical water extraction. The diffusion coefficient was determined by Fick's second law. By neglecting external mass transfer and solid particle in spherical form, a linear portion of Ln (1-(Ct/Co)) versus time was plotted in determining the diffusion coefficient. 6-gingerol obtained the higher yield at 130°C with diffusion coefficient of 8.582x10-11 m2/s whilst for 6-shogaol, the higher yield and diffusion coefficient at 170°C and 19.417 × 10-11 m2/s.
International Nuclear Information System (INIS)
Anisa, Nor Ilia; Azian, Noor; Sharizan, Mohd; Iwai, Yoshio
2014-01-01
6-gingerol and 6-shogaol are the main constituents as anti-inflammatory or bioactive compounds from zingiber officinale Roscoe. These bioactive compounds have been proven for inflammatory disease, antioxidatives and anticancer. The effect of temperature on diffusion coefficient for 6-gingerol and 6-shogaol were studied in subcritical water extraction. The diffusion coefficient was determined by Fick's second law. By neglecting external mass transfer and solid particle in spherical form, a linear portion of Ln (1-(Ct/Co)) versus time was plotted in determining the diffusion coefficient. 6-gingerol obtained the higher yield at 130°C with diffusion coefficient of 8.582x10 −11 m 2 /s whilst for 6-shogaol, the higher yield and diffusion coefficient at 170°C and 19.417 × 10 −11 m 2 /s.
On the Fetch Dependent Drag Coefficient over Coastal and Inland Seas
DEFF Research Database (Denmark)
Geernaert, G. L.; Smith, J. A.
a maximum when the phase speed of the dominant wind wave has a value near 7 u*, where u* is the friction velocity. This corresponds to a maximum near 2 km fetch during moderate windspeed, and the maximum value of the drag coefficient corresponds to an increased fetch of 13 km for windspeeds of 20 m/sec. We......The drag coefficient has been postulated by many investigators to depend on fetch. For constant windspeed and stability, laboratory data generally show an increasing drag coefficient with fetch while field observations show a decreasing dependence. In this study, we show that if one combines...... the spectral form of the roughness length proposed by Kitaigorodskii with the JONSWAP wave spectrum and extrapolate to very short fetch, then the predicted drag coefficient exhibits a behaviour which coarsely reproduces field and laboratory observations. The results indicate that the drag coefficient exhibits...
Separate measurement of local diffusion coefficients in grain boundaries and in adjacent regions
International Nuclear Information System (INIS)
Klotsman, S.M.; Kajgorodov, V.N.
1994-01-01
A new measuring technique is presented that allows one separate determination of grain boundary width and local diffusion coefficients. With the use of the technique presented phenomenological description is accompished for time and temperature dependences of relative and absolute level populations in a zone of preferential intercrystalline diffusion. Local diffusion coefficients obtained for the upper temperature limit of applicability of the technique proposed are in a good agreement with values calculated form coordinate distribution of atoic probes. Local diffusion coefficients determined at lower temperatures essentially differ from those calculated assuming that suction coefficient is equal to a coefficient of volume diffusion. Experimental dta are given for diffusion parameters in Ag, Pd and W polycrystals. 16 refs., 3 figs., 2 tabs
Energy Technology Data Exchange (ETDEWEB)
Laasonen, M.; Lahtinen, M.; Lustre, L.
1996-11-01
The greatest power losses in electricity transmission arise through a phenomenon called load losses. Corona losses caused by the surface discharge of electricity also constitute a considerable cost item. IVS, the nationwide network company, is investigating corona- induced losses, and has also commissioned similar research from IVO International, the Technical Research Centre of Finland (VTT) and from Tampere University of Technology. The research work strives to gain more in-depth knowledge on the phenomenon of frosting and its impact on corona losses. The correct prediction of frost helps reduce corona losses, while also cutting costs considerably. (orig.)
Management of hair loss diseases
Directory of Open Access Journals (Sweden)
Manabu Ohyama
2010-12-01
Full Text Available The treatment of hair loss diseases is sometimes difficult because of insufficient efficacy and limited options. However, recent advances in understanding of the pathophysiology and development of new remedies have improved the treatment of refractory hair loss conditions. In this article, an update on the management of hair loss diseases is provided, especially focusing on recently reported therapeutic approaches for alopecia areata (AA. An accurate diagnosis is indispensable to optimize treatment. Dry dermoscopy represents new diagnostic techniques, which could enable the differentiation of barely indistinguishable alopecias, e.g. AA and trichotillomania. An organized scalp biopsy adopting both vertical and transverse sectioning approaches also provides a deep insight into the pathophysiology of ongoing alopecias. Among various treatments for AA, intraregional corticosteroid and contact immunotherapy have been recognized as first-line therapies. However, some AA cases are refractory to both treatments. Recent studies have demonstrated the efficacy of pulse corticosteroid therapy or the combination of oral psoralen ultraviolet A therapy and systemic corticosteroids for severe AA. Previous clinical observations have suggested the potential role of antihistamines as supportive medications for AA. Experimental evaluation using AA model mice further supports their effectiveness in AA treatment. Finasteride opens up new possibilities for the treatment of androgenetic alopecia. For androgenetic alopecia patients refractory to finasteride, the combination of finasteride with topical minoxidil or the administration of dutasteride, another 5 alpha-reductase inhibitor, may provide better outcomes. Scarring alopecia is the most difficult form of hair loss disorder to treat. The bulge stem cell area is destroyed by unnecessary immune reactions with resultant permanent loss of hair follicle structures in scarring alopecia. Currently, treatment options for
Experimental determination of contraction coefficient and velocity ...
Indian Academy of Sciences (India)
Jailakshmi Menon
2018-04-16
Apr 16, 2018 ... Radial gates are widely used to control the flow in irrigation channels and spillways. Radial gates ... upstream water depth for a vertical sluice gate assuming hydrostatic ... energy loss on the discharge characteristics of vertical.
Self-diffusion coefficient of iron as affected by chelating agents using tracer technique
Energy Technology Data Exchange (ETDEWEB)
Massoud, M.A.; Abd-El-Sabour, M.F. (Agriculture Dept. for Soil and Water Research, Nuclear Research Centre, A.E.A., Cairo (Egypt)); Omar, M.A. (Ain Shams Univ., Cairo (Egypt). Faculty of Agriculture)
1983-01-01
The effect of Fe/sub 2/(So/sub 4/)/sub 3/, Fe-DTPA, and Fe-EDDHA on the self-diffusion coefficient of Fe in some soils of Egypt was studied. The effect of chelating compounds on the ratio between solid phase fraction of the labile Fe and its concentration in the soil solution (capacity factor) was also studied. The data reveals the following items of more interesting: 1) The use of chelating agents, i.e., DTPA and EDDHA increased the amount of Fe in soil solution, hence the capacity factor was decreased using these compounds. It seems that as the addition of Fe was in the chelated form in soil solution, the slight loss of 59Fe from solution when 59Fe - chelate was used could be attributed to the isotopic exchange with soil Fe. 2) It was found that the addition of either Fe-DTPA or Fe-EDDHA significantly increased the self-diffusion of Fe in soil as compared with Fe/sub 2/(So/sub 4/)/sub 3/. It was also noticed that the self-diffusion for Fe in the alluvial soil was greater than in the calcareous one due to the instance competition between Ca and Fe for the chelating ligands in the calcareous soil. It was also seen that soil texture affects Fe self-diffusion.
Self-diffusion coefficient of iron as affected by chelating agents using tracer technique
International Nuclear Information System (INIS)
Massoud, M.A.; Abd-El-Sabour, M.F.; Omar, M.A.
1983-01-01
The effect of Fe 2 (So 4 ) 3 , Fe-DTPA, and Fe-EDDHA on the self-diffusion coefficient of Fe in some soils of Egypt was studied. The effect of chelating compounds on the ratio between solid phase fraction of the labile Fe and its concentration in the soil solution (capacity factor) was also studied. The data reveals the following items of more interesting: 1) The use of chelating agents, i.e., DTPA and EDDHA increased the amount of Fe in soil solution, hence the capacity factor was decreased using these compounds. It seems that as the addition of Fe was in the chelated form in soil solution, the slight loss of 59Fe from solution when 59Fe - chelate was used could be attributed to the isotopic exchange with soil Fe. 2) It was found that the addition of either Fe-DTPA or Fe-EDDHA significantly increased the self-diffusion of Fe in soil as compared with Fe 2 (So 4 ) 3 . It was also noticed that the self-diffusion for Fe in the alluvial soil was greater than in the calcareous one due to the instance competition between Ca and Fe for the chelating ligands in the calcareous soil. It was also seen that soil texture affects Fe self-diffusion
Friction coefficient and effective interference at the implant-bone interface.
Damm, Niklas B; Morlock, Michael M; Bishop, Nicholas E
2015-09-18
Although the contact pressure increases during implantation of a wedge-shaped implant, friction coefficients tend to be measured under constant contact pressure, as endorsed in standard procedures. Abrasion and plastic deformation of the bone during implantation are rarely reported, although they define the effective interference, by reducing the nominal interference between implant and bone cavity. In this study radial forces were analysed during simulated implantation and explantation of angled porous and polished implant surfaces against trabecular bone specimens, to determine the corresponding friction coefficients. Permanent deformation was also analysed to determine the effective interference after implantation. For the most porous surface tested, the friction coefficient initially increased with increasing normal contact stress during implantation and then decreased at higher contact stresses. For a less porous surface, the friction coefficient increased continually with normal contact stress during implantation but did not reach the peak magnitude measured for the rougher surface. Friction coefficients for the polished surface were independent of normal contact stress and much lower than for the porous surfaces. Friction coefficients were slightly lower for pull-out than for push-in for the porous surfaces but not for the polished surface. The effective interference was as little as 30% of the nominal interference for the porous surfaces. The determined variation in friction coefficient with radial contact force, as well as the loss of interference during implantation will enable a more accurate representation of implant press-fitting for simulations. Copyright © 2015 Elsevier Ltd. All rights reserved.
Auger coefficient in GaInN-based laser structures
Energy Technology Data Exchange (ETDEWEB)
Draeger, Alexander Daniel; Netzel, Carsten; Brendel, Moritz; Joenen, Holger; Rossow, Uwe; Hangleiter, Andreas [Institut fuer Angewandte Physik, TU Braunschweig (Germany)
2010-07-01
Todays GaInN-based light emitting devices such as LEDs and laser diodes show excellent properties in terms of quantum efficiency or threshold current in the violet-blue spectral region. With increasing wavelength towards the green this performance decreases strongly. In particular at longer wavelengths, the quantum efficiency decreases for higher current densities, called the efficiency droop. This phenomenon is still subject to intensive research and different mechanisms such as Auger recombination, losses due to dislocations and carrier escape have been named as possible explanations. We combine optical gain measurements using the variable stripe length technique with model calculations of the optical gain spectra to derive the carrier lifetime. From the dependence of the inverse effective lifetime on carrier density we determine the recombination coefficients for radiative, nonradiative and Auger recombination. The Auger coefficients we obtained are about 1-2 x 10{sup -31} cm{sup 6}/s for GaInN quantum wells with 2.5eV
... Category: Share: Yes No, Keep Private Telogen Effluvium Hair Loss Share | It is normal to lose up to ... months after the "shock". This sudden increase in hair loss, usually described as the hair coming out in ...
DEFF Research Database (Denmark)
Egerup, P; Kolte, A M; Larsen, E C
2016-01-01
STUDY QUESTION: Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)? SUMMARY ANSWER: Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic...... impact in women with secondary RPL. WHAT IS KNOWN ALREADY: The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy...... losses plays a role for the prognosis in patients with a prior birth. STUDY DESIGN, SIZE, DURATION: This retrospective cohort study of pregnancy outcome in patients with unexplained secondary RPL included in three previously published, Danish double-blinded placebo-controlled trials of intravenous...
... ENTCareers Marketplace Find an ENT Doctor Near You Genes and Hearing Loss Genes and Hearing Loss Patient ... mutation may only have dystopia canthorum. How Do Genes Work? Genes are a road map for the ...
Fact Sheet & Menopause Bone Loss How are bone loss and menopause related? Throughout life your body keeps a balance between the ... lose bone faster than it can be replaced. Menopause—the time when menstrual periods end, which usually ...
... signals normally to the brain. In addition, hearing losses are classified according to the degree of severity: • Mild, • Moderate, • Severe, • Profound. Hearing losses are also classified according to the sound frequency ...
... go on to have successful pregnancies. Repeated pregnancy losses are rare. Testing and evaluation can be done ... find a cause if you have several pregnancy losses. Even if no cause is found, most couples ...
... this page: //medlineplus.gov/ency/article/001048.htm Occupational hearing loss To use the sharing features on this page, please enable JavaScript. Occupational hearing loss is damage to the inner ear from noise ...
Pregnancy Loss and Miscarriage
... D linked to miscarriage among women with prior pregnancy loss Release: Anti-HIV drug combination does not increase preterm birth risk, study suggests Release: Elevated blood pressure before pregnancy may increase chance of pregnancy loss All related ...
... Consumers Home For Consumers Consumer Updates Coping With Memory Loss Share Tweet Linkedin Pin it More sharing ... be evaluated by a health professional. What Causes Memory Loss? Anything that affects cognition—the process of ...
Weight loss surgery helps people with extreme obesity to lose weight. It may be an option if you cannot lose weight ... obesity. There are different types of weight loss surgery. They often limit the amount of food you ...
Myopic loss aversion revisited
Blavatskyy, Pavlo; Pogrebna, Ganna
2009-01-01
In this paper we reexamine several experimental papers on myopic loss aversion by analyzing individual rather than aggregate choice patterns. We find that the behavior of the majority of subjects is inconsistent with the hypothesis of myopic loss aversion.
A gradient estimate for solutions to parabolic equations with discontinuous coefficients
Fan, Jishan; Kim, Kyoungsun; Nagayasu, Sei; Nakamura, Gen
2011-01-01
Li-Vogelius and Li-Nirenberg gave a gradient estimate for solutions of strongly elliptic equations and systems of divergence forms with piecewise smooth coefficients, respectively. The discontinuities of the coefficients are assumed to be given by manifolds of codimension 1, which we called them emph{manifolds of discontinuities}. Their gradient estimate is independent of the distances between manifolds of discontinuities. In this paper, we gave a parabolic version of their results. T...
Lie Symmetry of the Diffusive Lotka–Volterra System with Time-Dependent Coefficients
Directory of Open Access Journals (Sweden)
Vasyl’ Davydovych
2018-02-01
Full Text Available Lie symmetry classification of the diffusive Lotka–Volterra system with time-dependent coefficients in the case of a single space variable is studied. A set of such symmetries in an explicit form is constructed. A nontrivial ansatz reducing the Lotka–Volterra system with correctly-specified coefficients to the system of ordinary differential equations (ODEs and an example of the exact solution with a biological interpretation are found.
Energy Technology Data Exchange (ETDEWEB)
Silvester, Leonard F.; Pitzer, Kenneth S.
1977-11-01
Heat of dilution and of solution data are fitted to the form of equation corresponding to that used successfully for activity and osmotic coefficients over a wide range of concentration. The resulting parameters give the change with temperature of the activity and osmotic coefficients. Results are reported for 84 electrolytes of 1-1, 2-1, 3-1, and 2-2 valence types.
Calculation of heat-kernel coefficients and usage of computer algebra
International Nuclear Information System (INIS)
Bel'kov, A.A.; Lanev, A.V.; Schaale, A.
1995-01-01
The calculation of heat-kernel coefficients with the classical De Witt algorithm has been discussed. We present the explicit form of the coefficients up to h 5 in the general case and up to h 7 min for the minimal parts. The results are compared with the expressions in other papers. A method to optimize the usage of memory for working with large expressions on universal computer algebra systems has been proposed. 20 refs
Transport coefficients in Lorentz plasmas with the power-law kappa-distribution
International Nuclear Information System (INIS)
Jiulin, Du
2013-01-01
Transport coefficients in Lorentz plasma with the power-law κ-distribution are studied by means of using the transport equation and macroscopic laws of Lorentz plasma without magnetic field. Expressions of electric conductivity, thermoelectric coefficient, and thermal conductivity for the power-law κ-distribution are accurately derived. It is shown that these transport coefficients are significantly modified by the κ-parameter, and in the limit of the parameter κ→∞ they are reduced to the standard forms for a Maxwellian distribution
Modeling of the substrate and product transfer coefficients for ethanol fermentation
International Nuclear Information System (INIS)
Zerajic, S.; Grbavcic, Z.; Savkovic-Stevanovic, J.
2008-01-01
The transfer phenomena of the substrate and product for ethanol fermentation with immobilized biocatalyst were investigated. Fermentation was carried out with a biocatalyst consisting of Ca-alginate gel in the form of two-layer spherical beads in anaerobic conditions. The determination of kinetic parameters was achieved by fitting bioreaction progress curves to the experimental data. The calculation of the diffusion coefficients was performed by numerical methods for experimental conditions. Finally, the glucose and ethanol transfer coefficients are defined and determined, using the effective diffusion coefficients. (Abstract Copyright [2008], Wiley Periodicals, Inc.)
Variable coefficient Korteweg-de Vries equations and travelling waves in an inhomogeneous medium
International Nuclear Information System (INIS)
Baby, B.V.
1987-04-01
The well-known Korteweg-de Vries equations with the coefficients as two arbitrary functions of the time variable, is studied in this paper. The Painleve property analysis provides the conditions on the two variable coefficients, in order to form the Lax pairs associated with this equation. The similarity analysis shows the non-existence of travelling wave solutions when the equation has variable coefficients. These results are used to show the non-existence of travelling waves in an inhomogeneous medium. (author). 33 refs
Recovering a coefficient in a parabolic equation using an iterative approach
Azhibekova, Aliya S.
2016-06-01
In this paper we are concerned with the problem of determining a coefficient in a parabolic equation using an iterative approach. We investigate an inverse coefficient problem in the difference form. To recover the coefficient, we minimize a residual functional between the observed and calculated values. This is done in a constructive way by fitting a finite-difference approximation to the inverse problem. We obtain some theoretical estimates for a direct and adjoint problem. Using these estimates we prove monotonicity of the objective functional and the convergence of iteration sequences.
Detecting genuine multipartite correlations in terms of the rank of coefficient matrix
International Nuclear Information System (INIS)
Li Bo; Kwek, Leong Chuan; Fan Heng
2012-01-01
We propose a method to detect genuine quantum correlation for arbitrary quantum states in terms of the rank of coefficient matrices associated with the pure state. We then derive a necessary and sufficient condition for a quantum state to possess genuine correlation, namely that all corresponding coefficient matrices have rank larger than 1. We demonstrate an approach to decompose the genuine quantum correlated state with high rank coefficient matrix into the form of product states with no genuine quantum correlation for a pure state. (paper)
Midgley, S M
2004-01-21
A novel parameterization of x-ray interaction cross-sections is developed, and employed to describe the x-ray linear attenuation coefficient and mass energy absorption coefficient for both elements and mixtures. The new parameterization scheme addresses the Z-dependence of elemental cross-sections (per electron) using a simple function of atomic number, Z. This obviates the need for a complicated mathematical formalism. Energy dependent coefficients describe the Z-direction curvature of the cross-sections. The composition dependent quantities are the electron density and statistical moments describing the elemental distribution. We show that it is possible to describe elemental cross-sections for the entire periodic table and at energies above the K-edge (from 6 keV to 125 MeV), with an accuracy of better than 2% using a parameterization containing not more than five coefficients. For the biologically important elements 1 coefficients. At higher energies, the parameterization uses fewer coefficients with only two coefficients needed at megavoltage energies.
Weyl q-coefficients for uq(3) and Racah q -coefficients for suq(2)
International Nuclear Information System (INIS)
Asherova, R.M.; Smirnov, Yu.F.; Tolstoy, V.N.
1996-01-01
With the aid of the projection-operator technique, the general analytic expression for the elements of the matrix that relates the U and T bases of an arbitrary finite-dimensional irreducible representation of the uq(3) quantum algebra (Weyl q-coefficients) is obtained for the case where the deformation parameter q is not equal to a square root of unity. The procedure for resummation of q-factorial expressions is used to prove that, modulo phase factors, these Weyl q-coefficients coincide with Racah q-coefficients for the suq(2) quantum algebra. It is also shown that, on the basis of one general formula, the q-analogs of all known general analytic expressions for the 6j symbols (and Racah coefficients) of the Lie algebras of the angular momentum can be obtained by using this resummation procedure. The symmetry properties of these q coefficients are discussed. The result is formulated in the following way: the general formulas for the q-6j symbols (Racah q-coefficients) of the suq(2) quantum algebra are obtained from the general formulas for the conventional 6j symbols (Racah coefficients) of the su(2) Lie algebra by replacing directly all factorials with q-factorials, the symmetry properties of the q-6j symbols being completely coincident with the symmetry properties of the conventional 6j symbols
Genome-scale cluster analysis of replicated microarrays using shrinkage correlation coefficient.
Yao, Jianchao; Chang, Chunqi; Salmi, Mari L; Hung, Yeung Sam; Loraine, Ann; Roux, Stanley J
2008-06-18
Currently, clustering with some form of correlation coefficient as the gene similarity metric has become a popular method for profiling genomic data. The Pearson correlation coefficient and the standard deviation (SD)-weighted correlation coefficient are the two most widely-used correlations as the similarity metrics in clustering microarray data. However, these two correlations are not optimal for analyzing replicated microarray data generated by most laboratories. An effective correlation coefficient is needed to provide statistically sufficient analysis of replicated microarray data. In this study, we describe a novel correlation coefficient, shrinkage correlation coefficient (SCC), that fully exploits the similarity between the replicated microarray experimental samples. The methodology considers both the number of replicates and the variance within each experimental group in clustering expression data, and provides a robust statistical estimation of the error of replicated microarray data. The value of SCC is revealed by its comparison with two other correlation coefficients that are currently the most widely-used (Pearson correlation coefficient and SD-weighted correlation coefficient) using statistical measures on both synthetic expression data as well as real gene expression data from Saccharomyces cerevisiae. Two leading clustering methods, hierarchical and k-means clustering were applied for the comparison. The comparison indicated that using SCC achieves better clustering performance. Applying SCC-based hierarchical clustering to the replicated microarray data obtained from germinating spores of the fern Ceratopteris richardii, we discovered two clusters of genes with shared expression patterns during spore germination. Functional analysis suggested that some of the genetic mechanisms that control germination in such diverse plant lineages as mosses and angiosperms are also conserved among ferns. This study shows that SCC is an alternative to the Pearson
... Staying Safe Videos for Educators Search English Español Hair Loss KidsHealth / For Kids / Hair Loss What's in this ... head are in the resting phase. What Causes Hair Loss? Men, especially older men, are the ones who ...
Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. It can lower ... at www.hormone.org/Spanish . Proven Weight Loss Methods Fact Sheet www.hormone.org
Heat transfer coefficients during quenching of steels
Energy Technology Data Exchange (ETDEWEB)
Hasan, H.S.; Jalil, J.M. [University of Technology, Department of Electromechanical Engineering, Baghdad (Iraq); Peet, M.J.; Bhadeshia, H.K.D.H. [University of Cambridge, Department of Materials Science and Metallurgy, Cambridge (United Kingdom)
2011-03-15
Heat transfer coefficients for quenching in water have been measured as a function of temperature using steel probes for a variety of iron alloys. The coefficients were derived from measured cooling curves combined with calculated heat-capacities. The resulting data were then used to calculate cooling curves using the finite volume method for a large steel sample and these curves have been demonstrated to be consistent with measured values for the large sample. Furthermore, by combining the estimated cooling curves with time-temperature-transformation (TTT) diagrams it has been possible to predict the variation of hardness as a function of distance via the quench factor analysis. The work should prove useful in the heat treatment of the steels studied, some of which are in the development stage. (orig.)
Fractal diffusion coefficient from dynamical zeta functions
Energy Technology Data Exchange (ETDEWEB)
Cristadoro, Giampaolo [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Str. 38, D 01187 Dresden (Germany)
2006-03-10
Dynamical zeta functions provide a powerful method to analyse low-dimensional dynamical systems when the underlying symbolic dynamics is under control. On the other hand, even simple one-dimensional maps can show an intricate structure of the grammar rules that may lead to a non-smooth dependence of global observables on parameters changes. A paradigmatic example is the fractal diffusion coefficient arising in a simple piecewise linear one-dimensional map of the real line. Using the Baladi-Ruelle generalization of the Milnor-Thurnston kneading determinant, we provide the exact dynamical zeta function for such a map and compute the diffusion coefficient from its smallest zero. (letter to the editor)
Fractal diffusion coefficient from dynamical zeta functions
International Nuclear Information System (INIS)
Cristadoro, Giampaolo
2006-01-01
Dynamical zeta functions provide a powerful method to analyse low-dimensional dynamical systems when the underlying symbolic dynamics is under control. On the other hand, even simple one-dimensional maps can show an intricate structure of the grammar rules that may lead to a non-smooth dependence of global observables on parameters changes. A paradigmatic example is the fractal diffusion coefficient arising in a simple piecewise linear one-dimensional map of the real line. Using the Baladi-Ruelle generalization of the Milnor-Thurnston kneading determinant, we provide the exact dynamical zeta function for such a map and compute the diffusion coefficient from its smallest zero. (letter to the editor)
Asymptotic normalization coefficients and astrophysical factors
International Nuclear Information System (INIS)
Mukhamedzhanov, A.M.; Azhari, A.; Clark, H.L.; Gagliardi, C.A.; Lui, Y.-W.; Sattarov, A.; Trache, L.; Tribble, R.E.; Burjan, V.; Kroha, V.; Carstoiu, F.
2000-01-01
The S factor for the direct capture reaction 7 Be(p,γ) 8 B can be found at astrophysical energies from the asymptotic normalization coefficients (ANC's) which provide the normalization of the tails of the overlap functions for 8 B → 7 Be + p. Peripheral transfer reactions offer a technique to determine these ANC's. Using this technique, the 10 B( 7 Be, 8 B) 9 Be and 14 N( 7 Be, 8 B) 13 C reactions have been used to measure the asymptotic normalization coefficient for 7 Be(p, γ) 8 B. These results provide an indirect determination of S 17 (0). Analysis of the existing 9 Be(p, γ) 10 B experimental data within the framework of the R-matrix method demonstrates that experimentally measured ANC's can provide a reasonable determination of direct radiative capture rates. (author)
Differences between charged-current coefficient functions
International Nuclear Information System (INIS)
Moch, S.; Rogal, M.; Vogt, A.
2007-08-01
Second- and third-order results are presented for the structure functions of charged-current deepinelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding crossing-even and -odd coefficient functions, including those for the longitudinal structure function not covered in the literature so far. At three loops we compute the lowest five moments of these differences for all three structure functions and provide approximate expressions in Bjorken-x space. Also calculated is the related third-order coefficient-function correction to the Gottfried sum rule. We confirm the conjectured suppression of these quantities if the number of colours is large. Finally we derive the second- and third-order QCD contributions to the Paschos-Wolfenstein ratio used for the determination of the weak mixing angle from neutrino-nucleon deep-inelastic scattering. These contributions are found to be small. (orig.)
Activity coefficient of aqueous sodium bicarbonate
Energy Technology Data Exchange (ETDEWEB)
Pitzer, Kenneth S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Peiper, J. Christopher [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
1980-09-01
The determination of the activity coefficient and related properties of sodium bicarbonate presents special problems because of the appreciable vapor pressure of CO_{2} above such solutions. With the development of reliable equations for the thermodynamic properties of mixed electrolytes, it is possible to determine the parameters for NaHCO_{3} from cell measurements or NaCl-NaHCO_{3} mixtures. Literature data are analyzed to illustrate the method and provide interim values, hoever it is noted that further measurements over a wider range of concentrations would yield more definitive results. Lastly, an estimate is also given for the activity coefficient of KHCO_{3}.
Gate Control Coefficient Effect on CNFET Characteristic
International Nuclear Information System (INIS)
Sanudin, Rahmat; Ma'Radzi, Ahmad Alabqari; Nayan, Nafarizal
2009-01-01
The development of carbon nanotube field-effect transistor (CNFET) as alternative to existing transistor technology has long been published and discussed. The emergence of this device offers new material and structure in building a transistor. This paper intends to do an analysis of gate control coefficient effect on CNFET performance. The analysis is based on simulation study of current-voltage (I-V) characteristic of ballistic CNFET. The simulation study used the MOSFET-like CNFET mathematical model to establish the device output characteristic. Based on the analysis of simulation result, it is found that the gate control coefficient contributes to a significant effect on the performance of CNFET. The result also shown the parameter could help to improve the device performance in terms of its output and response as well. Nevertheless, the characteristic of the carbon nanotube that acts as the channel is totally important in determining the performance of the transistor as a whole.
Atomic rate coefficients in a degenerate plasma
Aslanyan, Valentin; Tallents, Greg
2015-11-01
The electrons in a dense, degenerate plasma follow Fermi-Dirac statistics, which deviate significantly in this regime from the usual Maxwell-Boltzmann approach used by many models. We present methods to calculate the atomic rate coefficients for the Fermi-Dirac distribution and present a comparison of the ionization fraction of carbon calculated using both models. We have found that for densities close to solid, although the discrepancy is small for LTE conditions, there is a large divergence from the ionization fraction by using classical rate coefficients in the presence of strong photoionizing radiation. We have found that using these modified rates and the degenerate heat capacity may affect the time evolution of a plasma subject to extreme ultraviolet and x-ray radiation such as produced in free electron laser irradiation of solid targets.
Relations between coefficients of fractional parentage
International Nuclear Information System (INIS)
Zamick, L.
2007-01-01
For each of the (9/2) (11/2), and (13/2) single j shells we have only one state with J=j v=3 for a five particle system. For four identical particles there can be more than one state of seniority four. We note some 'ratio' relations for the coefficients of fractional parentage for the four and five identical particle systems, which are found in the works of de Shalit and Talmi [Nuclear Shell Theory (Academic Press, New York, 1963)] and Talmi [Simple Models of Complex Nuclei (Harwood Academic, Reading, UK, 1993)] to be useful for explaining the vanishing of a five particle coefficients of fractional parentage (cfp). These relations are used to show that there is a special (g 9/2 ) 4 I=4 v=4 wave function that cannot be admixed with an I=4 v=2 wave function, even with seniority violating interactions
The coefficient of friction, particularly of ice
International Nuclear Information System (INIS)
Mills, Allan
2008-01-01
The static and dynamic coefficients of friction are defined, and values from 0.3 to 0.6 are quoted for common materials. These drop to about 0.15 when oil is added as a lubricant. Water ice at temperatures not far below 0 °C is remarkable for low coefficients of around 0.05 for static friction and 0.04–0.02 for dynamic friction, but these figures increase as the temperature diminishes. Reasons for the slipperiness of ice are summarized, but they are still not entirely clear. One hypothesis suggests that it is related to the transient formation of a lubricating film of liquid water produced by frictional heating. If this is the case, some composition melting a little above ambient temperatures might provide a skating rink that did not require expensive refrigeration. Various compositions have been tested, but an entirely satisfactory material has yet to be found
Diffusion coefficient calculations for cylindrical cells
International Nuclear Information System (INIS)
Lam-Hime, M.
1983-03-01
An accurate and general diffusion coefficient calculation for cylindrical cells is described using isotropic scattering integral transport theory. This method has been particularly applied to large regular lattices of graphite-moderated reactors with annular coolant channels. The cells are divided into homogeneous zones, and a zone-wise flux expansion is used to formulate a collision probability problem. The reflection of neutrons at the cell boundary is accounted for by the conservation of the neutron momentum. The uncorrected diffusion coefficient Benoist's definition is used, and the described formulation does not neglect any effect. Angular correlation terms, energy coupling non-uniformity and anisotropy of the classical flux are exactly taken into account. Results for gas-graphite typical cells are given showing the importance of these approximations
Doppler coefficient measurements in Zebra Core 5
International Nuclear Information System (INIS)
Baker, A.R.; Wheeler, R.C.
1965-11-01
Measurements using a central hot loop in Zebra Core 5 are described. Results are given for the Doppler coefficients found in a number of assemblies with PuO 2 and 16% PuO 2 /84% depleted UO 2 pins, loaded with different combinations of steel, sodium or void pins. The mixed oxide results are in general about 20% more negative than was calculated using the FD2 data set, but agreement is good if the plutonium contributions in the calculations are omitted. The small positive Doppler coefficient calculated for Pu239 was not observed, and two measurements indicated instead a small negative effect. The Doppler effect in the mixed oxide systems was found to vary approximately as 1/T. The results from the empty loop and non-fissile assemblies indicate either a small negative Doppler effect in steel or alternatively the presence of an unexplained expansion effect. (author)
Activity coefficients of solutes in binary solvents
International Nuclear Information System (INIS)
Gokcen, N.A.
1982-01-01
The activity coefficients in dilute ternary systems are discussed in detail by using the Margules equations. Analyses of some relevant data at high temperatures show that the sparingly dissolved solutes in binary solvents follow complex behavior even when the binary solvents are very nearly ideal. It is shown that the activity data on the solute or the binary system cannot permit computation of the remaining activities except for the regular solutions. It is also shown that a fourth-order equation is usually adequate in expressing the activity coefficient of a solute in binary solvents at high temperatures. When the activity data for a binary solvent are difficult to obtain in a certain range of composition, the activity data for a sparingly dissolved solute can be used to supplement determination of the binary activities
Differences between charged-current coefficient functions
Energy Technology Data Exchange (ETDEWEB)
Moch, S.; Rogal, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences
2007-08-15
Second- and third-order results are presented for the structure functions of charged-current deepinelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding crossing-even and -odd coefficient functions, including those for the longitudinal structure function not covered in the literature so far. At three loops we compute the lowest five moments of these differences for all three structure functions and provide approximate expressions in Bjorken-x space. Also calculated is the related third-order coefficient-function correction to the Gottfried sum rule. We confirm the conjectured suppression of these quantities if the number of colours is large. Finally we derive the second- and third-order QCD contributions to the Paschos-Wolfenstein ratio used for the determination of the weak mixing angle from neutrino-nucleon deep-inelastic scattering. These contributions are found to be small. (orig.)
Zhang, Juping; Yang, Chan; Jin, Zhen; Li, Jia
2018-07-14
In this paper, the correlation coefficients between nodes in states are used as dynamic variables, and we construct SIR epidemic dynamic models with correlation coefficients by using the pair approximation method in static networks and dynamic networks, respectively. Considering the clustering coefficient of the network, we analytically investigate the existence and the local asymptotic stability of each equilibrium of these models and derive threshold values for the prevalence of diseases. Additionally, we obtain two equivalent epidemic thresholds in dynamic networks, which are compared with the results of the mean field equations. Copyright © 2018 Elsevier Ltd. All rights reserved.
Analytical expressions for the electron backscattering coefficient
International Nuclear Information System (INIS)
August, H.J.; Wernisch, J.
1989-01-01
Several analytical expressions for the electron backscattering coefficient for massive homogeneous samples are compared with experimental data, directing special attention to the dependence of this quantity on the electron acceleration energy. It is shown that this dependence generally cannot be neglected. The expression proposed by Hunger and Kuechler turns out to be better than that of Love and Scott, although even the better formula can be slightly improved by a small modification. (author)
Thin film description by wavelet coefficients statistics
Czech Academy of Sciences Publication Activity Database
Boldyš, Jiří; Hrach, R.
2005-01-01
Roč. 55, č. 1 (2005), s. 55-64 ISSN 0011-4626 Grant - others:GA UK(CZ) 173/2003 Institutional research plan: CEZ:AV0Z10750506 Keywords : thin films * wavelet transform * descriptors * histogram model Subject RIV: BD - Theory of Information Impact factor: 0.360, year: 2005 http://library.utia.cas.cz/separaty/2009/ZOI/boldys-thin film description by wavelet coefficients statistics .pdf
Analytic posteriors for Pearson's correlation coefficient.
Ly, Alexander; Marsman, Maarten; Wagenmakers, Eric-Jan
2018-02-01
Pearson's correlation is one of the most common measures of linear dependence. Recently, Bernardo (11th International Workshop on Objective Bayes Methodology, 2015) introduced a flexible class of priors to study this measure in a Bayesian setting. For this large class of priors, we show that the (marginal) posterior for Pearson's correlation coefficient and all of the posterior moments are analytic. Our results are available in the open-source software package JASP.
Analytic posteriors for Pearson's correlation coefficient
Ly, A.; Marsman, M.; Wagenmakers, E.-J.
2018-01-01
Pearson's correlation is one of the most common measures of linear dependence. Recently, Bernardo (11th International Workshop on Objective Bayes Methodology, 2015) introduced a flexible class of priors to study this measure in a Bayesian setting. For this large class of priors, we show that the (marginal) posterior for Pearson's correlation coefficient and all of the posterior moments are analytic. Our results are available in the open‐source software package JASP.
Transport Coefficients from Large Deviation Functions
Gao, Chloe Ya; Limmer, David T.
2017-01-01
We describe a method for computing transport coefficients from the direct evaluation of large deviation functions. This method is general, relying on only equilibrium fluctuations, and is statistically efficient, employing trajectory based importance sampling. Equilibrium fluctuations of molecular currents are characterized by their large deviation functions, which are scaled cumulant generating functions analogous to the free energies. A diffusion Monte Carlo algorithm is used to evaluate th...
Correlation and prediction of gaseous diffusion coefficients.
Marrero, T. R.; Mason, E. A.
1973-01-01
A new correlation method for binary gaseous diffusion coefficients from very low temperatures to 10,000 K is proposed based on an extended principle of corresponding states, and having greater range and accuracy than previous correlations. There are two correlation parameters that are related to other physical quantities and that are predictable in the absence of diffusion measurements. Quantum effects and composition dependence are included, but high-pressure effects are not. The results are directly applicable to multicomponent mixtures.
Moderator temperature coefficient in BWR core
International Nuclear Information System (INIS)
Naito, Yoshitaka
1977-01-01
Temperature dependences of infinite multiplication factor k sub(infinity) and neutron leakage from the core must be examined for estimation of moderator temperature coefficient. Temperature dependence on k sub(infinity) has been investigated by many researchers, however, the dependence on neutron leakage of a BWR with cruciformed control rods has hardly been done. Because there are difficulties and necessity on calculations of three space dimensional and multi-energy groups neutron distribution in a BWR core. In this study, moderator temperature coefficients of JPDR-II (BWR) core were obtained by calculation with DIFFUSION-ACE, which is newly developed three-dimensional multi-group computer code. The results were compared with experimental data measured from 20 to 275 0 C of the moderator temperature and the good agreement was obtained between calculation and measurement. In order to evaluate neutron leakage from the core, the other two calculations were carried out, adjusting criticality by uniform absorption rate and by material buckling. The former underestimated neutron leakage and the latter overestimated it. Discussion on the results shows that in order to estimate the temperature coefficient of BWR, neutron leakage must be evaluated precisely, therefore the calculation at actual pattern of control rods is necessary. (auth.)
Analysis of flow coefficient in chair manufacture
Directory of Open Access Journals (Sweden)
Ivković Dragoljub
2005-01-01
Full Text Available The delivery on time is not possible without the good-quality planning of deadlines, i.e. planning of the manufacturing process duration. The study of flow coefficient enables the realistic forecasting of the manufacturing process duration. This paper points to the significance of the study of flow coefficient on scientific basis so as to determine the terms of the end of the manufacture of chairs made of sawn timber. Chairs are the products of complex construction, often almost completely made of sawn timber as the basic material. They belong to the group of export products, so it is especially significant to analyze the duration of the production cycle, and the type and the degree of stoppages in this type of production. Parallel method of production is applied in chair manufacture. The study shows that the value of flow coefficient is close to one or higher, in most cases. The results indicate that the percentage of interoperational stoppage is unjustifiably high, so it is proposed how to decrease the percentage of stoppages in the manufacturing process.
Varying coefficients model with measurement error.
Li, Liang; Greene, Tom
2008-06-01
We propose a semiparametric partially varying coefficient model to study the relationship between serum creatinine concentration and the glomerular filtration rate (GFR) among kidney donors and patients with chronic kidney disease. A regression model is used to relate serum creatinine to GFR and demographic factors in which coefficient of GFR is expressed as a function of age to allow its effect to be age dependent. GFR measurements obtained from the clearance of a radioactively labeled isotope are assumed to be a surrogate for the true GFR, with the relationship between measured and true GFR expressed using an additive error model. We use locally corrected score equations to estimate parameters and coefficient functions, and propose an expected generalized cross-validation (EGCV) method to select the kernel bandwidth. The performance of the proposed methods, which avoid distributional assumptions on the true GFR and residuals, is investigated by simulation. Accounting for measurement error using the proposed model reduced apparent inconsistencies in the relationship between serum creatinine and GFR among different clinical data sets derived from kidney donor and chronic kidney disease source populations.
Socioeconomic modifications of the universal soil loss equation
Erol, A.; Koşkan, Ö.; Başaran, M. A.
2015-08-01
While social scientists have long focused on socioeconomic and demographic factors, physical modelers typically study soil loss using physical factors. In the current environment, it is becoming increasingly important to consider both approaches simultaneously for the conservation of soil and water, and the improvement of land use conditions. This study uses physical and socioeconomic factors to find a coefficient that evaluates the combination of these factors. It aims to determine the effect of socioeconomic factors on soil loss and, in turn, to modify the universal soil loss equation (USLE). The methodology employed in this study specifies that soil loss can be calculated and predicted by comparing the degree of soil loss in watersheds, with and without human influence, given the same overall conditions. A coefficient for socioeconomic factors, therefore, has been determined based on adjoining watersheds (WS I and II), employing simulation methods. Combinations of C and P factors were used in the USLE to find the impact of their contributions to soil loss. The results revealed that these combinations provided good estimation of soil loss amounts for the second watershed, i.e., WS II, from the adjoining watersheds studied in this work. This study shows that a coefficient of 0.008 modified the USLE to reflect the socioeconomic factors, such as settlement, influencing the amount of soil loss in the studied watersheds.
Socio-economic modifications of the Universal Soil Loss Equation
Erol, A.; Koşkan, Ö.; Başaran, M. A.
2015-06-01
While social scientists have long focused on socio-economic and demographic factors, physical modelers typically study soil loss using physical factors. In the current environment, it is becoming increasingly important to consider both approaches simultaneously for the conservation of soil and water, and the improvement of land use conditions. This study uses physical and socio-economic factors to find a coefficient that evaluates the combination of these factors. It aims to determine the effect of socio-economic factors on soil loss and, in turn, to modify the Universal Soil Loss Equation (USLE). The methodology employed in this study specifies that soil loss can be calculated and predicted by comparing the degree of soil loss in watersheds, with and without human influence, given the same overall conditions. A coefficient for socio-economic factors, therefore, has been determined based on adjoining watersheds (WS I and II), employing simulation methods. Combinations of C and P factors were used in the USLE to find the impact of their contributions on soil loss. The results revealed that these combinations provided good estimation of soil loss amounts for the second watershed, i.e. WS II, from the adjoining watersheds studied in this work. This study shows that a coefficient of 0.008 modified the USLE to reflect the socio-economic factors as settlement influencing the amount of soil loss in the watersheds studied.
Alexander, Stanley A; Askari, Marjan; Lewis, Patricia
2015-03-01
To investigate space changes with the premature loss of primary first molars and their relationship to permanent molar occlusion and facial forms. Two hundred twenty-six participants (ranging in age from 7 years 8 months to 8 years 2 months; 135 female, 91 male) met all inclusion criteria designed to study space loss as a result of the premature loss of the primary first molar. After 9 months, space loss was evaluated in relationship to molar occlusion and facial form. Statistical evaluation was performed with the paired t-test and with a two-way analysis of variance for independent groups. Patients with leptoprosopic facial form and end-on molar occlusions all exhibited a statistically significant difference when compared to controls in terms of space loss (P molar occlusion displayed space loss as well (P molar occlusion displayed space loss in the maxilla (P molar occlusions showed no significant difference in space loss. The relationship between the first permanent molar occlusion and facial form of the child has an influence on the loss of space at the primary first molar site.
International Nuclear Information System (INIS)
Martin, T.H.; Seamen, J.F.; Jobe, D.O.
1993-01-01
The authors experiments show energy losses between 2 and 10 times that of the resistive time predictions. The experiments used hydrogen, helium, air, nitrogen, SF 6 polyethylene, and water for the switching dielectric. Previously underestimated switch losses have caused over predicting the accelerator outputs. Accurate estimation of these losses is now necessary for new high-efficiency pulsed power devices where the switching losses constitute the major portion of the total energy loss. They found that the switch energy losses scale as (V peak I peak ) 1.1846 . When using this scaling, the energy losses in any of the tested dielectrics are almost the same. This relationship is valid for several orders of magnitude and suggested a theoretical basis for these results. Currents up to .65 MA, with voltages to 3 MV were applied to various gaps during these experiments. The authors data and the developed theory indicates that the switch power loss continues for a much longer time than the resistive time, with peak power loss generally occurring at peak current in a ranging discharge instead of the early current time. All of the experiments were circuit code modeled after developing a new switch loss version based on the theory. The circuit code predicts switch energy loss and peak currents as a function of time. During analysis of the data they noticed slight constant offsets between the theory and data that depended on the dielectric. They modified the plasma conductivity for each tested dielectric to lessen this offset
Estimation of radon emanation coefficient for soil and flyash
International Nuclear Information System (INIS)
Sahu, S.K.; Swarnkar, M.; Ajmal, P.Y.; Pandit, G.G.; Puranik, V.D.
2012-01-01
Since terrestrial materials include radium ( 226 Ra) originating from the decay of uranium ( 238 U), all such materials release radon ( 222 Rn) to varying degrees. When a radium atom decays to radon, the energy generated is strong enough to send the radon atom a distance of about 40 nanometers-this is known as alpha recoil. For a radon atom to escape the radium atom must be within the recoil distance from the grain surface of flyash or soil and the direction of recoil must send the radon atom toward the outside of the grain. Therefore, all of the radon atoms generated by the radium contained in flyash or soil grain are actually not released into pore spaces and mobilized. The fraction of radon atoms generated from radium decay that are released from into flyash or soil pore space is defined as the radon emanation coefficient or emanating power, of the material. Grain size and shape are two of the important factors that control the radon emanation coefficient because they determine in part how much uranium and radium is near enough to the surface of the grain to allow the newly-formed radon to escape into a pore space. In a porous medium, where the radon is in radioactive equilibrium with its parent radium, the emanation coefficient is given by the expression: where C 0 is the undiluted radon activity concentration in the pores of the medium, and C Ra is the radium activity concentration of the sample. The 226 Ra activity concentration of the flyash and soil sample were determined by using the g-spectrometry. C 0 was determined by the can experiment using LR-115 for flyash and soil samples. The C 0 values for flyash and soil samples were found to be 245.7 Bq/m 3 and 714.3 Bq/m 3 respectively. The radon emanation coefficient for flyash was found to be 0.0024 while that for soil was 0.0092. Therefore the soil sample was found to be four times higher radon emanation coefficient than flyash which is in line with the results reported in the literatures. This may suggest
Plum, M.A.
2016-01-01
Beam loss is a critical issue in high-intensity accelerators, and much effort is expended during both the design and operation phases to minimize the loss and to keep it to manageable levels. As new accelerators become ever more powerful, beam loss becomes even more critical. Linacs for H- ion beams, such as the one at the Oak Ridge Spallation Neutron Source, have many more loss mechanisms compared to H+ (proton) linacs, such as the one being designed for the European Spallation Neutron Source. Interesting H- beam loss mechanisms include residual gas stripping, H+ capture and acceleration, field stripping, black-body radiation and the recently discovered intra-beam stripping mechanism. Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H+ and H- accelerators. Machine protection systems play an important role in limiting the beam loss.
Densified waste form and method for forming
Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina
2015-08-25
Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.
Study of Stirling Engine Efficiency Coefficient under Conditions Being Close to Real Ones
Directory of Open Access Journals (Sweden)
R. M. Abramian
2013-01-01
Full Text Available An absolute internal efficiency coefficient of the Stirling engine has been obtained without regenerator and with regenerator under conditions when van der Waals gas serves as a working medium. The paper reveals that while taking into account own volume of molecules thermal efficiency coefficient of the Stirling engine depends on mole number of the working medium and it is slightly increasing in comparison with the case of an ideal gas. The paper gives consideration to heat losses while the Stirling machine operates with heat regeneration. Dependence of regeneration rate on time of heat transfer has been obtained in the paper.
The measurement of friction coefficient down to 1.8 K for LHC Magnets
Artoos, K; Poncet, Alain; Savary, F; Veness, R J M
1994-01-01
The Large Hadron Collider (LHC) proposed for construction at CERN consists of a series of high field superconducting dipole magnet operating at 1.8K. The mechanical structure of these magnets contains many components in close contact. A knowledge of the friction coefficient between these components is required. Indeed, during assembly and cool down of the magnets, prestresses must be transferred to the superconducting coils. During operation, frictional heating may provoke loss of superconductivity. A machine has been built at CERN to measure the coefficient of friction from room temperature down to 1.8K. This paper describes the cryogenic tribometer and the results collected to date.
Environmental cost of distribution transformer losses
International Nuclear Information System (INIS)
Georgilakis, Pavlos S.
2011-01-01
Improvements in energy efficiency of electrical equipment reduce the greenhouse gas (GHG) emissions and contribute to the protection of the environment. Moreover, as system investment and energy costs continue to increase, electric utilities are increasingly interested in installing energy-efficient transformers at their distribution networks. This paper analyzes the impact of the environmental cost of transformer losses on the economic evaluation of distribution transformers. This environmental cost is coming form the cost to buy GHG emission credits because of the GHG emissions associated with supplying transformer losses throughout the transformer lifetime. Application results on the Hellenic power system for 21 transformer offers under 9 different scenarios indicate that the environmental cost of transformer losses can reach on average 34% and 8% of transformer purchasing price for high loss and medium loss transformers, respectively. That is why it is important to incorporate the environmental cost of transformer losses into the economic evaluation of distribution transformers.
Leaching of nuclear power reactor waste forms
International Nuclear Information System (INIS)
Endo, L.S.; Villalobos, J.P.; Miyamoto, H.
1987-01-01
The leaching tests for immobilized power reactor wastes carried out at IPEN are described. These wastes forms consist mainly of spent resins and boric acid concentrates solidified in ordinary Portland cement. All tests were conducted according to the ISO and IAEA recommendations. Three years leaching results are reported. The cesium diffuvity coefficients determined out of these results are about 1 x 10 -8 cm 2 /s for boric acid waste form and 9 x 10 -9 cm 2 /s for ion-exchange resin waste. Strontium diffusivity coefficients found are about 3 x 10 -11 cm 2 /s and 9 x 10 -11 cm 2 /s respectively. (Author) [pt
Comparison of field-measured radon diffusion coefficients with laboratory-measured coefficients
International Nuclear Information System (INIS)
Lepel, E.A.; Silker, W.B.; Thomas, V.W.; Kalkwarf, D.R.
1983-04-01
Experiments were conducted to compare radon diffusion coefficients determined for 0.1-m depths of soils by a steady-state method in the laboratory and diffusion coefficients evaluated from radon fluxes through several-fold greater depths of the same soils covering uranium-mill tailings. The coefficients referred to diffusion in the total pore volume of the soils and are equivalent to values for the quantity, D/P, in the Generic Environmental Impact Statement on Uranium Milling prepared by the US Nuclear Regulatory Commission. Two soils were tested: a well-graded sand and an inorganic clay of low plasticity. For the flux evaluations, radon was collected by adsorption on charcoal following passive diffusion from the soil surface and also from air recirculating through an aluminum tent over the soil surface. An analysis of variance in the flux evaluations showed no significant difference between these two collection methods. Radon diffusion coefficients evaluated from field data were statistically indistinguishable, at the 95% confidence level, from those measured in the laboratory; however, the low precision of the field data prevented a sensitive validation of the laboratory measurements. From the field data, the coefficients were calculated to be 0.03 +- 0.03 cm 2 /s for the sand cover and 0.0036 +- 0.0004 cm 2 /s for the clay cover. The low precision in the coefficients evaluated from field data was attributed to high variation in radon flux with time and surface location at the field site
Adaptive Neuro-Fuzzy Computing Technique for Determining Turbulent Flow Friction Coefficient
Directory of Open Access Journals (Sweden)
Mohammad Givehchi
2013-08-01
Full Text Available Estimation of the friction coefficient in pipes is very important in many water and wastewater engineering issues, such as distribution of velocity and shear stress, erosion, sediment transport and head loss. In analyzing these problems, knowing the friction coefficient, can obtain estimates that are more accurate. In this study in order to estimate the friction coefficient in pipes, using adaptive neuro-fuzzy inference systems (ANFIS, grid partition method was used. For training and testing of neuro-fuzzy model, the data derived from the Colebrook’s equation was used. In the neuro-fuzzy approach, pipe relative roughness and Reynolds number are considered as input variables and friction coefficient as output variable is considered. Performance of the proposed approach was evaluated by using of the data obtained from the Colebrook’s equation and based on statistical indicators such as coefficient determination (R2, root mean squared error (RMSE and mean absolute error (MAE. The results showed that the adaptive nerou-fuzzy inference system with grid partition method and gauss model as an input membership function and linear as an output function could estimate friction coefficient more accurately than other conditions. The new proposed approach in this paper has capability of application in the practical design issues and can be combined with mathematical and numerical models of sediment transfer or real-time updating of these models.
Quenching of Einstein-coefficients by photons
International Nuclear Information System (INIS)
Aumayr, F.; Skinner, C.H.; Suckewer, S.; Princeton Univ., NJ; Lee, W.
1991-02-01
Experimental evidence is presented for the change of Einstein's A-coefficients for spontaneous transitions from the upper laser level of an argon ion laser discharge due to the presence of the high-intensity laser flux. To demonstrate that this quenching effect cannot be attributed to a reduction in self-absorption of the strong spontaneous emission line, absorption and line profile measurements have been performed. Computer modelling of the reduction of self absorption due to Rabi splitting also indicated that this effect is too small to explain the observed quenching of spontaneous line emissions. 13 refs., 11 figs
Quenching of Einstein-coefficients by photons
International Nuclear Information System (INIS)
Aumayr, F.; Lee, W.; Skinner, C.H.; Suckewer, S.
1991-03-01
Experimental evidence is presented for the change of Einstein's A- coefficients for spontaneous transitions from the upper laser level of argon ion laser discharge due to the presence of the high- intensity laser flux. To demonstrate that this quenching effect cannot be attributed to a reduction in self-absorption of the strong spontaneous emission line, absorption and line profile measurements have been performed. Computer modelling of the reduction of self absorption due to Rabi splitting also indicated that this effect is too small to explain the observed quenching of spontaneous line emissions. 13 refs., 11 figs
Kinetic coefficients in isotopically disordered crystals
International Nuclear Information System (INIS)
Zhernov, Arkadii P; Inyushkin, Alexander V
2002-01-01
Peculiarities of the behavior of kinetic coefficients, like thermal conductivity, electric conductivity, and thermoelectric power, in isotopically disordered materials are reviewed in detail. New experimental and theoretical results on the isotope effects in the thermal conductivity of diamond, Ge, and Si semiconductors are presented. The suppression effect of phonon-drag thermopower in the isotopically disordered Ge crystals is discussed. The influence of dynamic and static crystal lattice deformations on the electric conductivity of metals as well as on the ordinary phonon spectrum deformations is considered. (reviews of topical problems)
Peltier coefficient measurement in a thermoelectric module
International Nuclear Information System (INIS)
Garrido, Javier; Casanovas, Alejandro; Chimeno, José María
2013-01-01
A new method for measuring the Peltier coefficient in a thermocouple X/Y based on the energy balance at the junction has been proposed recently. This technique needs only the hot and cold temperatures of a thermoelectric module when an electric current flows through it as the operational variables. The temperature evolutions of the two module sides provide an evident and accurate idea of the Peltier effect. From these temperatures, the heat transfer between the module and the ambient is also evaluated. The thermoelectric phenomena are described in the framework of an observable theory. Based on this procedure, an experiment is presented for a university teaching laboratory at the undergraduate level. (paper)
Friction coefficient determination by electrical resistance measurements
Tunyagi, A.; Kandrai, K.; Fülöp, Z.; Kapusi, Z.; Simon, A.
2018-05-01
A simple and low-cost, DIY-type, Arduino-driven experiment is presented for the study of friction and measurement of the friction coefficient, using a conductive rubber cord as a force sensor. It is proposed for high-school or college/university-level students. We strongly believe that it is worthwhile planning, designing and performing Arduino and compatible sensor-based experiments in physics class in order to ensure a better understanding of phenomena, develop theoretical knowledge and multiple experimental skills.
Effective Diffusion Coefficients in Coal Chars
DEFF Research Database (Denmark)
Johnsson, Jan Erik; Jensen, Anker
2001-01-01
Knowledge of effective diffusion coefficients in char particles is important when interpreting experimental reactivity measurements and modeling char combustion or NO and N2O reduction. In this work, NO and N2O reaction with a bituminous coal char was studied in a fixed-bed quartz glass reactor....... In the case of strong pore diffusion limitations, the error in the interpretation of experimental results using the mean pore radius could be a factor of 5 on the intrinsic rate constant. For an average coal char reacting with oxygen at 1300 K, this would be the case for particle sizes larger than about 50...
Kinetic coefficients for quark-antiquark plasma
International Nuclear Information System (INIS)
Czyz, W.; Florkowski, W.
1986-03-01
The quark-antiquark plasma near equilibrium is studied. The results are based on the Heinz kinetic equations with the Boltzmann collision operator approximated by a relaxation term with the relaxation time, τ, treated as a small parameter. Linear in τ solutions of these equations are used to calculate the transport coefficients: the non-abelian version of Ohm's law, and the shear and volume viscosities. We introduce new chemical potentials which determine the color density matrix of quarks (antiquarks). Gradients of these potentials generate color currents. 12 refs. (author)
System of coefficients for charged-particle beam linear transformation by a magnetic dipole element
International Nuclear Information System (INIS)
Tarantin, N.I.
1979-01-01
A new technique for consideration of dipole magnet ion-optical effect has been developed to study the problems of commutation and monochromatization of a charged particle beam. In a new form obtained are systematized coefficients of linear transformation (CLT) of the charged particle beam for radial and axial motions in a magnetic dipole element (MDE) including a dipole magnet and two gaps without magnetic field. Given is a method of graphic determination of MDE parameters and main CLT. The new form of coefficients and conditions of the transformations feasibility considerably facilitates the choice and calculation of dipole elements
Patel, Mansi; Harrison, Shannon; Sinclair, Rodney
2013-01-01
Hair loss is a common complaint, both in men and women, and use of prescription medications is widespread. When there is a temporal association between the onset of hair loss and commencement of a medication, the medication is commonly thought to have caused the hair loss. However, hair loss and in particular telogen effluvium may occur in response to a number of triggers including fever, hemorrhage, severe illness, stress, and childbirth, and a thorough exclusion of these potential confounders is necessary before the hair loss can be blamed on the medication. Certain medications are known to cause hair loss by a variety of mechanisms including anagen arrest, telogen effluvium, or accentuation of androgenetic alopecia by androgens. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.
Schmidt, Klaus; Schnaus, Anja
2016-01-01
This handbook presents the basic aspects of actuarial loss reserving. Besides the traditional methods, it also includes a description of more recent ones and a discussion of certain problems occurring in actuarial practice, like inflation, scarce data, large claims, slow loss development, the use of market statistics, the need for simulation techniques and the task of calculating best estimates and ranges of future losses. In property and casualty insurance the provisions for payment obligations from losses that have occurred but have not yet been settled usually constitute the largest item on the liabilities side of an insurer's balance sheet. For this reason, the determination and evaluation of these loss reserves is of considerable economic importance for every property and casualty insurer. Actuarial students, academics as well as practicing actuaries will benefit from this overview of the most important actuarial methods of loss reserving by developing an understanding of the underlying stochastic models...
Forecast Correlation Coefficient Matrix of Stock Returns in Portfolio Analysis
Zhao, Feng
2013-01-01
In Modern Portfolio Theory, the correlation coefficients decide the risk of a set of stocks in the portfolio. So, to understand the correlation coefficients between returns of stocks, is a challenge but is very important for the portfolio management. Usually, the stocks with small correlation coefficients or even negative correlation coefficients are preferred. One can calculate the correlation coefficients of stock returns based on the historical stock data. However, in order to control the ...
Link prediction with node clustering coefficient
Wu, Zhihao; Lin, Youfang; Wang, Jing; Gregory, Steve
2016-06-01
Predicting missing links in incomplete complex networks efficiently and accurately is still a challenging problem. The recently proposed Cannistrai-Alanis-Ravai (CAR) index shows the power of local link/triangle information in improving link-prediction accuracy. Inspired by the idea of employing local link/triangle information, we propose a new similarity index with more local structure information. In our method, local link/triangle structure information can be conveyed by clustering coefficient of common-neighbors directly. The reason why clustering coefficient has good effectiveness in estimating the contribution of a common-neighbor is that it employs links existing between neighbors of a common-neighbor and these links have the same structural position with the candidate link to this common-neighbor. In our experiments, three estimators: precision, AUP and AUC are used to evaluate the accuracy of link prediction algorithms. Experimental results on ten tested networks drawn from various fields show that our new index is more effective in predicting missing links than CAR index, especially for networks with low correlation between number of common-neighbors and number of links between common-neighbors.
Graphical comparison of calculated internal conversion coefficients
International Nuclear Information System (INIS)
Ewbank, W.B.
1980-11-01
Calculated values of the coefficients of internal conversion of gamma rays in the K shell and L 1 , L 2 , L 3 subshells from published tabulations by Band and Trzhaskovskaya and by Roesel et al. at Data Nucl. Data Tables, 21, 92-514(1978) are compared with values obtained by computer interpolation among tabulated values of Hager and Seltzer Nucl. Data, A4, 1-235(1968). In some cases, agreement among the three calculations is remarkably good, and differences are generally less than 5%. In a few cases, there are differences as large as 20 to 50%, corresponding to the threshold effect described by Roesel et al. The Z-dependent resonance minimum described by Roesel et al. is also observed in the comparison of E1-E4 conversion in the L 1 subshell. In several cases (notably M1-M4 conversion in the K shell and L 1 subshell), the Band and Roesel calculations show dramatically different dependence on gamma energy and atomic number. For Z = 100, the Band calculation for E4 conversion in the L 3 subshell shows irregular behavior at energies below the K-shell binding energy. A few high-quality measurements of internal conversion coefficients (+-5%) would help greatly to establish a basis for choice among the theoretical calculations. 32 figures
Transport coefficients of a dissociating gas
International Nuclear Information System (INIS)
Lebed', I.V.
1987-01-01
The calculation of the transport coefficients of a dissociating gas involves fundamental difficulties which arise when the internal degrees of freedom of the molecules are taken strictly into account. In practical calculations extensive use is made of the approximation in the context of which the dependence of a diffusion velocity of the molecule on its internal state is totally neglected. In this case the expressions for the stress tensor and the diffusion velocities coincide with the corresponding expressions for a mixture of structureless particles; in the expression for the heat flux the diffusion transport of internal energy is taken only approximately into account. Here, analytic expressions for the diffusion velocities, heat flux and stress tensor are obtained without introducing simplifying assumptions. The calculation method is based on an approximate method of calculating the transport coefficients of a multicomponent mixture of structureless particles. The relations obtained are analyzed and compared with the existing results; their accuracy is estimated. A closed system of equations of gas dynamics is presented for a number of cases of practical importance
Sets of Fourier coefficients using numerical quadrature
International Nuclear Information System (INIS)
Lyness, J. N.
2001-01-01
One approach to the calculation of Fourier trigonometric coefficients f(r) of a given function f(x) is to apply the trapezoidal quadrature rule to the integral representation f(r)=(line i ntegral)(sub 0)(sup 1) f(x)e(sup -2(pi)irx)dx. Some of the difficulties in this approach are discussed. A possible way of overcoming many of these is by means of a subtraction function. Thus, one sets f(x)= h(sub p-1)(x)+ g(sub p)(x), where h(sub -1)(x) is an algebraic polynomial of degree p-1, specified in such a way that the Fourier series of g(sub p)(x) converges more rapidly than that of f(x). To obtain the Fourier coefficients of f(x), one uses an analytic expression for those of h(sub p-1)(x) and numerical quadrature to approximately those of g(sub p)(x)
Shear viscosity coefficient from microscopic models
International Nuclear Information System (INIS)
Muronga, Azwinndini
2004-01-01
The transport coefficient of shear viscosity is studied for a hadron matter through microscopic transport model, the ultrarelativistic quantum molecular dynamics (UrQMD), using the Green-Kubo formulas. Molecular-dynamical simulations are performed for a system of light mesons in a box with periodic boundary conditions. Starting from an initial state composed of π,η,ω,ρ,φ with a uniform phase-space distribution, the evolution takes place through elastic collisions, production, and annihilation. The system approaches a stationary state of mesons and their resonances, which is characterized by common temperature. After equilibration, thermodynamic quantities such as the energy density, particle density, and pressure are calculated. From such an equilibrated state the shear viscosity coefficient is calculated from the fluctuations of stress tensor around equilibrium using Green-Kubo relations. We do our simulations here at zero net baryon density so that the equilibration times depend on the energy density. We do not include hadron strings as degrees of freedom so as to maintain detailed balance. Hence we do not get the saturation of temperature but this leads to longer equilibration times
Estimation of the heat transfer coefficient in melt spinning process
International Nuclear Information System (INIS)
Tkatch, V I; Maksimov, V V; Grishin, A M
2009-01-01
Effect of the quenching wheel velocity in the range 20.7-26.5 m/s on the cooling rate as well as on the structure and microtopology of the contact surfaces of the glass-forming FeNiPB melt-spun ribbons has been experimentally studied. Both the values of the cooling rate and heat transfer coefficient at the wheel-ribbon interface estimated from the temperature vs. time curves recorded during melt spinning runs are in the ranges (1.6-5.2)x10 6 K/s and (2.8-5.2)x10 5 Wm -2 K -1 , respectively, for ribbon thicknesses of 31.4-22.0 μm. It was found that the density of the air pockets at the underside surface of ribbons decreases while its average depth remains essentially unchanged with the wheel velocity. Using the surface quality parameters the values of the heat transfer coefficient in the areas of direct ribbon-wheel contact were evaluated to be ranging from 5.75 to 6.65x10 5 Wm -2 K -1 .
A correlation to the heat transfer coefficient in nucleate boiling
International Nuclear Information System (INIS)
Ribatski, Gherhardt; Jabardo, Jose M. Saiz
1999-01-01
Nucleate boiling heat transfer is a complex phenomenon, making the development of a correlation for the heat transfer coefficient rather cumbersome due to the number of physical parameters involved in it. Some authors have followed a pragmatic approach to the problem by correlating the heat transfer coefficient in terms of reduced primitive properties. Two of the most knowledgeable authors who have followed this approach are Gorenflo and Cooper. Comparisons have been performed among results from the correlations proposed by these researchers and experimental results obtained elsewhere for refrigerants R-11, R-113 and R-114. These comparisons have shown that Cooper's correlation is best fitted for halocarbon refrigerants. The correlation proposed by Gorenflo ads the difficulty of including a numerical factor specific for each fluid. Leiner modified Gorenflo's correlation to determine the numerical factor as a function of known physical parameters of the fluid. In present study, the form of this function has been investigated for halocarbon refrigerants. The obtained correlation is written in terms of the following parameters: reduced pressure, eccentric and compressibility factors at the critical state, and a dimensionless specific heat of the vapor phase. The correlation compares well with experimental results. (author)
Transfer coefficients of radionuclides secreted in milk of dairy cows
International Nuclear Information System (INIS)
Sam, D.; Williams, W.F.; Rockmann, D.D.; Allen, J.T.
1980-01-01
This study simulated experimentally the transfer of radionuclides to milk of dairy cows on a worst-case situation using various radionuclides known to emanate from nuclear power stations and which have been detected on particulates. Two lactating Holstein cows were administered orally one gelatin capsule containing 10 radionuclides in water-soluble form per day for 14 consecutive days. Milk samples were collected and aliquots analyzed in a germanium lithium-drifted detector coupled to a 2048-multichannel gamma-ray analyzer to measure small amounts of complex mixtures of radionuclides. The transfer coefficients of the radionuclides were calculated when their secretion in milk reached or approached a plateau of concentration. The radionuclides and their transfer coefficients to milk were: chromium 51 less than 0.01%; manganese 54 0.033 +- 0.005%; cobalt 60 0.01 +- 0.002%; iron 59 0.0048 +- 0.002%; zinc 65 0.31 +- 0.07%; selenium 75 0.29 +- 0.1%; antimony 125 0.011 +- 0.003%; iodine 131 0.88 +- 0.05%; and cesium 137 0.79 +- 0.08%
Water Use and Crop Coefficients in Sprinkler Irrigated Rice
Directory of Open Access Journals (Sweden)
Antonino Spanu
Full Text Available Field experiments were carried out during the years 2002, 2004, 2005 and 2006 to analyze water-soil-atmosphere interactions in sprinkler irrigated rice. The research was carried out in Sardinia (39º 59’ N; 8º 40’ E, at altitude 15 m. The cultivars used in the experiments, respectively in 2002 and in 2004-2005-2006, were Irat 212 and Eurosis. In each year cultivars were subjected to the same crop management. Irrigation was applied since the emergence with the sprinkler method, taking into account the loss of water from ‘Class A’ pan evaporation. Soil water content was monitored at 0.10 m intervals until 1.00-m depth using a ‘Diviner 2000’ (Sentek. In 2002 seven irrigation scheduling treatments were compared. In 2004, 2005, 2006 irrigation treatments provided for optimal soil water conditions during the growing season. In 2002 the results highlighted: 1 0-0.20 m depth was the most important layer for crop water uptake and the best correlated layer with rice rough yield; 2 the positive relationship between yield and water supply was significant until 6500 m3 ha-1 of water applied. Further seasonal irrigation volumes did not increase significantly yield. In 2004, 2005 and 2006 the analysis of the soil water balance at different crop phenological stages allowed to estimate crop coefficients (Kc using the Penman-Monteith equation and the ‘Class A’ pan evaporation (Kcev. Kc varied over the three-year period on average from 0.90 to 1.07 and 0.97, respectively for the emergence-end of tillering, end of tillering-heading and heading-maturing periods, while crop coefficients as a ratio between maximum crop evapotranspiration (ETc and Epan, Kcev ranged from 0.78 to 0.92 and 0.81 for the same time periods.
Microscopic calculation of friction coefficients for use in heavy-ion reaction
International Nuclear Information System (INIS)
Iwamoto, A.; Harada, K.; Yoshida, S.
1981-01-01
A microscopic calculation has been done for the friction coefficient for use in the deep-inelastic collision of heavy nuclei. We adopted the formalism of the linear response theory as a basis and used the adiabatic base of the two-center shell model. Several reaction channels with the total mass numbers of 236 and 260 systems were investigated. The friction coefficients for the radial and deforming motions including the coupling term were calculated as a function of the distance between two nuclei and deformation of the two nuclei for each channel. The general feature of the friction coefficient, its strength and form factor, was clarified in this model and comparison with the results of other models were done. It was found that our model gives a physically plausible value for the friction coefficient as a whole. (orig.)
International Nuclear Information System (INIS)
Newman, D.F.; Leonard, B.R. Jr.; Trapp, T.J.; Gore, B.F.; Kottwitz, D.A.; Thompson, J.K.; Purcell, W.L.; Stewart, K.B.
1977-05-01
A comparison of calculated and measured neutron multiplication factors as a function of temperature was made for three graphite-moderated lattices in the High Temperature Lattice Test Reactor (HTLTR) using 233 UO 2 --ThO 2 fuels in varying amounts and configurations. Correlation of neutronic analysis methods and cross section data with the experimental measurements forms the basis for assessing the accuracy of the methods and data and developing confidence in the ability to predict the temperature coefficient of reactivity for various High Temperature Gas-Cooled Reactor (HTGR) conditions in which 233 U and thorium are present in the fuel. The calculated values of k/sub infinity/(T) were correlated with measured values using two least-squares-fitted correlation coefficients: (1) a normalization factor, and (2) a temperature coefficient bias factor. These correlations indicate the existence of a negative (nonconservative) bias in temperature coefficients of reactivity calculated using ENDF/B-IV cross section data
Determining leach rates of monolithic waste forms
International Nuclear Information System (INIS)
Gilliam, T.M.; Dole, L.R.
1986-01-01
The ANS 16.1 Leach Procedure provides a conservative means of predicting long-term release from monolithic waste forms, offering a simple and relatively quick means of determining effective solid diffusion coefficients. As presented here, these coefficients can be used in a simple model to predict maximum release rates or be used in more complex site-specific models to predict actual site performance. For waste forms that pass the structural integrity test, this model also allows the prediction of EP-Tox leachate concentrations from these coefficients. Thus, the results of the ANS 16.1 Leach Procedure provide a powerful tool that can be used to predict the waste concentration limits in order to comply with the EP-Toxicity criteria for characteristically nonhazardous waste. 12 refs., 3 figs
Analysis of the absorption coefficient by annealing in carbon implanted Nd: YVO4
International Nuclear Information System (INIS)
Sanchez-Morales, M E; Vazquez, G V; Lifante, G; Cantelar, E; Rickards, J; Trejo-Luna, R
2011-01-01
Low loss in optical waveguides is very important in order to achieve high laser efficiency. Waveguide fabrication by ion implantation generates color centers, leading to absorption losses which can be reduced by annealing; however, this process may eliminate the waveguide and hence it is necessary to consider both the optimum annealing time and temperature. This work reports the behavior of the absorption coefficient by successive annealing steps in Nd:YVO 4 implanted with a dose of 5xl0 14 ions/cm 2 .
Dynamics Coefficient for Two-Phase Soil Model
Directory of Open Access Journals (Sweden)
Wrana Bogumił
2015-02-01
Full Text Available The paper investigates a description of energy dissipation within saturated soils-diffusion of pore-water. Soils are assumed to be two-phase poro-elastic materials, the grain skeleton of which exhibits no irreversible behavior or structural hysteretic damping. Description of motion and deformation of soil is introduced as a system of equations consisting of governing dynamic consolidation equations based on Biot theory. Selected constitutive and kinematic relations for small strains and rotation are used. This paper derives a closed form of analytical solution that characterizes the energy dissipation during steady-state vibrations of nearly and fully saturated poro-elastic columns. Moreover, the paper examines the influence of various physical factors on the fundamental period, maximum amplitude and the fraction of critical damping of the Biot column. Also the so-called dynamic coefficient which shows amplification or attenuation of dynamic response is considered.
Reassessment of tritium dose coefficients for the general public
International Nuclear Information System (INIS)
Melintescu, A.; Galeriu, D.; Takeda, H.
2007-01-01
Concerns of increased risk from tritium intake by humans have been claimed in the past. The arguments concerning the radiobiological effectiveness of tritium, its longer retention in the human body and the presence of tritium in the DNA hydration shell are analysed in this paper. A biokinetic model for tritiated water and organically bound tritium retention in the human body is used, based on a common approach for mammals using energy and hydrogen metabolism and tested separately with animal experiments. Extension to this model to humans considers the increased role of the brain, food quality and unique growth patterns of humans. Various ages and genders for Caucasians are considered. For an intake of tritium in organic forms in the diet, the retention for the female is of about a factor 2 compared with ICRP recommendations. Effective dose coefficients are estimated to be about a factor of 2 to 3 higher than those of the ICRP. (authors)
Matrimonial distance, inbreeding coefficient and population size: Dhangar data.
Majumder, P P; Malhotra, K C
1979-01-01
Data on the distance between the birthplaces of spouses (matrimonial distance) were collected from 2,260 married individuals belonging to 21 endogamous castes of the Dhangar (shepherd) cast-cluster of Maharashtra, India. The general form of the distribution of matrimonial distances is one which is extremely positively skewed and leptokurtic. The percentage of intra-village marriages generally decreases from the southern areas of Maharashtra to the northern areas of the state, as does the inbreeding coefficient. This situation is in conformity with the socio-cultural norms regulating matrimonial choice in south and north India. An attempt has been made to relate the degree of inbreeding to the mean matrimonial distance and population size. The mean matrimonial distance is more useful in predicting the degree of inbreeding than population size.
Transport Coefficients for the NASA Lewis Chemical Equilibrium Program
Svehla, Roger A.
1995-01-01
The new transport property data that will be used in the NASA Lewis Research Center's Chemical Equilibrium and Applications Program (CEA) is presented. It complements a previous publication that documented the thermodynamic and transport property data then in use. Sources of the data and a brief description of the method by which the data were obtained are given. Coefficients to calculate the viscosity, thermal conductivity, and binary interactions are given for either one, or usually, two temperature intervals, typically 300 to 1000 K and 1000 to 5000 K. The form of the transport equation is the same as used previously. The number of species was reduced from the previous database. Many species for which the data were estimated were eliminated from the database. Some ionneutral interactions were added.
Siegel modular forms and black hole entropy
Energy Technology Data Exchange (ETDEWEB)
Belin, Alexandre; Castro, Alejandra [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, Postbus 94485, 1090 GL Amsterdam (Netherlands); Gomes, João [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, Postbus 94485, 1090 GL Amsterdam (Netherlands); Institute for Theoretical Physics, University of Utrecht,Leuvenlaan 3584 CE Utrecht (Netherlands); Keller, Christoph A. [Department of Mathematics, ETH Zurich,CH-8092 Zurich (Switzerland)
2017-04-11
We discuss the application of Siegel Modular Forms to Black Hole entropy counting. The role of the Igusa cusp form χ{sub 10} in the D1D5P system is well-known, and its transformation properties are what allows precision microstate counting in this case. We apply a similar method to extract the Fourier coefficients of other Siegel modular and paramodular forms, and we show that they could serve as candidates for other types of black holes. We investigate the growth of their coefficients, identifying the dominant contributions and the leading logarithmic corrections in various regimes. We also discuss similarities and differences to the behavior of χ{sub 10}, and possible physical interpretations of such forms both from a microscopic and gravitational point of view.
Heat losses through pipe connections in hot water stores
DEFF Research Database (Denmark)
Andersen, Elsa; Fan, Jianhua; Furbo, Simon
2007-01-01
The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further......, calculations show that the yearly thermal performance of solar domestic hot water systems is strongly reduced if the hot water tank has a thermal bridge located at the top of the tank....
Tran, LenhAnh P.; Grundfast, Kenneth M.
1997-01-01
This article discusses inheritance patterns in hearing loss, epidemiology, clues to genetic causes, locating genes that cause hereditary disorders, genes related to hearing loss disorders in individuals with Usher syndrome, Waardenburg syndrome, Treacher-Collins syndrome, Branchio-oto-renal and Pendred syndromes, and the significance of finding…
Loss muinasjuturaamatust / Agu Veetamm
Veetamm, Agu, 1953-
2004-01-01
Ballindaloch on üks väheseid Shoti losse, kus omanikud aastaringselt elavad. 450 aastat on loss kuulunud Macpherson-Grantide suguvõsale. Praegu on lossi omanikuks Clare Nancy Macpherson-Grant Russell, kelle kujundatud on kiviktaimla ja rosaarium. Lossi ajaloost, omanikest, ümberehitustest, ringkäigust lossis, pargist. 14 ill
Current assisted superplastic forming of titanium alloy
Directory of Open Access Journals (Sweden)
Wang Guofeng
2015-01-01
Full Text Available Current assisted superplastic forming combines electric heating technology and superplastic forming technology, and can overcome some shortcomings of traditional superplastic forming effectively, such as slow heating rate, large energy loss, low production efficiency, etc. Since formability of titanium alloy at room temperature is poor, current assisted superplastic forming is suitable for titanium alloy. This paper mainly introduces the application of current assisted superplastic forming in the field of titanium alloy, including forming technology of double-hemisphere structure and bellows.
Concurrent credit portfolio losses.
Sicking, Joachim; Guhr, Thomas; Schäfer, Rudi
2018-01-01
We consider the problem of concurrent portfolio losses in two non-overlapping credit portfolios. In order to explore the full statistical dependence structure of such portfolio losses, we estimate their empirical pairwise copulas. Instead of a Gaussian dependence, we typically find a strong asymmetry in the copulas. Concurrent large portfolio losses are much more likely than small ones. Studying the dependences of these losses as a function of portfolio size, we moreover reveal that not only large portfolios of thousands of contracts, but also medium-sized and small ones with only a few dozens of contracts exhibit notable portfolio loss correlations. Anticipated idiosyncratic effects turn out to be negligible. These are troublesome insights not only for investors in structured fixed-income products, but particularly for the stability of the financial sector. JEL codes: C32, F34, G21, G32, H81.
Advanced friction modeling for sheet metal forming
Hol, J.; Cid Alfaro, M.V.; de Rooij, Matthias B.; Meinders, Vincent T.
2012-01-01
The Coulomb friction model is frequently used for sheet metal forming simulations. This model incorporates a constant coefficient of friction and does not take the influence of important parameters such as contact pressure or deformation of the sheet material into account. This article presents a
Advanced friction modeling in sheet metal forming
Hol, J.; Cid Alfaro, M.V.; Meinders, Vincent T.; Huetink, Han
2011-01-01
The Coulomb friction model is frequently used for sheet metal forming simulations. This model incorporates a constant coefficient of friction and does not take the influence of important parameters such as contact pressure or deformation of the sheet material into account. This article presents a
Molar extinction coefficients of some fatty acids
DEFF Research Database (Denmark)
Sandhu, G.K.; Singh, K.; Lark, B.S.
2002-01-01
) and stearic acid (C18H36O2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement......The attenuation of gamma rays in some fatty acids, viz. formic acid (CH2O2), acetic acid (C2H4O2), propionic acid (C3H6O2), butyric acid (C4H8O2), n-hexanoic acid (C6H12O2), n-caprylic acid (C8H16O2), lauric acid (C12H24O2), myristic acid (C14H28O2), palmitic acid (C16H32O2), oleic acid (C18H34O2...
Coefficient alpha and interculture test selection.
Thurber, Steven; Kishi, Yasuhiro
2014-04-01
The internal consistency reliability of a measure can be a focal point in an evaluation of the potential adequacy of an instrument for adaptation to another cultural setting. Cronbach's alpha (α) coefficient is often used as the statistical index for such a determination. However, alpha presumes a tau-equivalent test and may constitute an inaccurate population estimate for multidimensional tests. These notions are expanded and examined with a Japanese version of a questionnaire on nursing attitudes toward suicidal patients, originally constructed in Sweden using the English language. The English measure was reported to have acceptable internal consistency (α) albeit the dimensionality of the questionnaire was not addressed. The Japanese scale was found to lack tau-equivalence. An alternative to alpha, "composite reliability," was computed and found to be below acceptable standards in magnitude and precision. Implications for research application of the Japanese instrument are discussed. © The Author(s) 2012.
Thermal expansion coefficient determination by CBED
International Nuclear Information System (INIS)
Angelini, P.; Bentley, J.
1984-01-01
The present application of CBED involves measurements of thermal-expansion coefficients by measurement of changes in HOLZ line positions as a function of temperature. Previous work on this subject was performed on Si at a constant accelerating voltage of 100 kV between about 90 and 600 K. Diffraction patterns were recorded and line shifts correlated to lattice parameter changes. Differences were noted between values determined by CBED and accepted thermal expansion values. Significant HOLZ line interactions and splitting occurring in the (111) patterns were noted to contribute to the differences. Preliminary measurements have been made on Al, Al 2 O 3 , and single-crystal tau (Ni/sub 20.3/Ti/sub 2.7/B 6 ). An example of changes in HOLZ lines present in (114) patterns for Al are shown and the effect of temperature on the position of lines in the pattern illustrated
Friction Experiments for Dynamical Coefficient Measurement
Directory of Open Access Journals (Sweden)
J. J. Arnoux
2011-01-01
Full Text Available An experimental study, including three experimental devices, is presented in order to investigate dry friction phenomena in a wide range of sliding speeds for the steel on steel contact. A ballistic setup, with an air gun launch, allows to estimate the friction coefficient between 20 m/s and 80 m/s. Tests are completed by an adaptation of the sensor on a hydraulic tensile machine (0.01 m/s to 3 m/s and a pin-on-disk tribometer mounted on a CNC lathe (1 to 30 m/s. The interactions at the asperity scale are characterized by a white light interferometer surface analysis.
Transport coefficients in superfluid neutron stars
Energy Technology Data Exchange (ETDEWEB)
Tolos, Laura [Instituto de Ciencias del Espacio (IEEC/CSIC) Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain); Frankfurt Institute for Advances Studies. Johann Wolfgang Goethe University, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main (Germany); Manuel, Cristina [Instituto de Ciencias del Espacio (IEEC/CSIC) Campus Universitat Autònoma de Barcelona, Facultat de Ciències, Torre C5, E-08193 Bellaterra (Barcelona) (Spain); Sarkar, Sreemoyee [Tata Institute of Fundamental Research, Homi Bhaba Road, Mumbai-400005 (India); Tarrus, Jaume [Physik Department, Technische Universität München, D-85748 Garching (Germany)
2016-01-22
We study the shear and bulk viscosity coefficients as well as the thermal conductivity as arising from the collisions among phonons in superfluid neutron stars. We use effective field theory techniques to extract the allowed phonon collisional processes, written as a function of the equation of state and the gap of the system. The shear viscosity due to phonon scattering is compared to calculations of that coming from electron collisions. We also comment on the possible consequences for r-mode damping in superfluid neutron stars. Moreover, we find that phonon collisions give the leading contribution to the bulk viscosities in the core of the neutron stars. We finally obtain a temperature-independent thermal conductivity from phonon collisions and compare it with the electron-muon thermal conductivity in superfluid neutron stars.
Clustering stocks using partial correlation coefficients
Jung, Sean S.; Chang, Woojin
2016-11-01
A partial correlation analysis is performed on the Korean stock market (KOSPI). The difference between Pearson correlation and the partial correlation is analyzed and it is found that when conditioned on the market return, Pearson correlation coefficients are generally greater than those of the partial correlation, which implies that the market return tends to drive up the correlation between stock returns. A clustering analysis is then performed to study the market structure given by the partial correlation analysis and the members of the clusters are compared with the Global Industry Classification Standard (GICS). The initial hypothesis is that the firms in the same GICS sector are clustered together since they are in a similar business and environment. However, the result is inconsistent with the hypothesis and most clusters are a mix of multiple sectors suggesting that the traditional approach of using sectors to determine the proximity between stocks may not be sufficient enough to diversify a portfolio.
Ghost imaging based on Pearson correlation coefficients
International Nuclear Information System (INIS)
Yu Wen-Kai; Yao Xu-Ri; Liu Xue-Feng; Li Long-Zhen; Zhai Guang-Jie
2015-01-01
Correspondence imaging is a new modality of ghost imaging, which can retrieve a positive/negative image by simple conditional averaging of the reference frames that correspond to relatively large/small values of the total intensity measured at the bucket detector. Here we propose and experimentally demonstrate a more rigorous and general approach in which a ghost image is retrieved by calculating a Pearson correlation coefficient between the bucket detector intensity and the brightness at a given pixel of the reference frames, and at the next pixel, and so on. Furthermore, we theoretically provide a statistical interpretation of these two imaging phenomena, and explain how the error depends on the sample size and what kind of distribution the error obeys. According to our analysis, the image signal-to-noise ratio can be greatly improved and the sampling number reduced by means of our new method. (paper)
Thermal linear expansion coefficient of structural graphites
International Nuclear Information System (INIS)
Virgil'ev, Yu.S.
1995-01-01
The data now available on radiation induced changes of linear thermal expansion coefficients (CTE) for native structural carbon materials (SCM) irradiated with high fluences are summarized. For different types of native and foreign SCM dose dependences of CTE changes in the temperature range of 300...1600 K and at fluences up to (2...3)x10 22 n/cm 2 (E>0.18 meV) are compared. On the base of this comparison factors defined the CTE changes under neutron irradiation are revealed and the explanation of observed phenomena is offered. Large number of the factors revealed does not allowed to calculate CTE radiation induced changes. 39 refs.; 16 figs.; 5 tabs
Leaching of nuclear power reactor wastes forms
International Nuclear Information System (INIS)
Endo, L.S.; Villalobos, J.P.; Miyamoto, H.
1986-01-01
The leaching tests for power reactor wastes carried out at IPEN/CNEN-SP are described. These waste forms consist mainly of spent resins and boric acid concentrates solidified in ordinary Portland cement. All tests were conducted according to the ISO and IAEA recommendations. 3 years leaching results are reported, determining cesium and strontium diffusivity coefficients for boric acid waste form and ion-exchange resins. (Author) [pt
Axially symmetric reconstruction of plasma emission and absorption coefficients
International Nuclear Information System (INIS)
Yang Lixin; Jia Hui; Yang Jiankun; Li Xiujian; Chen Shaorong; Liu Xishun
2013-01-01
A layered structure imaging model is developed in order to reconstruct emission coefficients and absorption coefficients simultaneously, in laser fusion core plasma diagnostics. A novel axially symmetric reconstruction method that utilizes the LM (Levenberg-Marquardt) nonlinear least squares minimization algorithm is proposed based on the layered structure. Numerical simulation results demonstrate that the proposed method is sufficiently accurate to reconstruct emission coefficients and absorption coefficients, and when the standard deviation of noise is 0.01, the errors of emission coefficients and absorption coefficients are 0.17, 0.22, respectively. Furthermore, this method could perform much better on reconstruction effect compared with traditional inverse Abel transform algorithms. (authors)
Heavy quark energy loss in nuclear medium
International Nuclear Information System (INIS)
Zhang, Benr-Wei; Wang, Enke; Wang, Xin-Nian
2003-01-01
Multiple scattering, modified fragmentation functions and radiative energy loss of a heavy quark propagating in a nuclear medium are investigated in perturbative QCD. Because of the quark mass dependence of the gluon formation time, the medium size dependence of heavy quark energy loss is found to change from a linear to a quadratic form when the initial energy and momentum scale are increased relative to the quark mass. The radiative energy loss is also significantly suppressed relative to a light quark due to the suppression of collinear gluon emission by a heavy quark
Scheibler, Robin; Hurley, Paul
2012-03-01
We present a novel, accurate and fast algorithm to obtain Fourier series coefficients from an IC layer whose description consists of rectilinear polygons on a plane, and how to implement it using off-the-shelf hardware components. Based on properties of Fourier calculus, we derive a relationship between the Discrete Fourier Transforms of the sampled mask transmission function and its continuous Fourier series coefficients. The relationship leads to a straightforward algorithm for computing the continuous Fourier series coefficients where one samples the mask transmission function, compute its discrete Fourier transform and applies a frequency-dependent multiplicative factor. The algorithm is guaranteed to yield the exact continuous Fourier series coefficients for any sampling representing the mask function exactly. Computationally, this leads to significant saving by allowing to choose the maximal such pixel size and reducing the fast Fourier transform size by as much, without compromising accuracy. In addition, the continuous Fourier series is free from aliasing and follows closely the physical model of Fourier optics. We show that in some cases this can make a significant difference, especially in modern very low pitch technology nodes.
Asua, J.M.; Beuermann, S.; Buback, M.; Castignolles, P.; Charleux, B.; Gilbert, R.G.; Hutchinson, R.A.; Leiza, J.R.; Nikitin, A.N.; Vairon, J.P.; Herk, van A.M.
2004-01-01
Propagation rate coefficients, kp, for free-radical polymerization of butyl acrylate (BA) previously reported by several groups are critically evaluated. All data were determined by the combination of pulsed-laser polymerization (PLP) and subsequent polymer analysis by size exclusion (SEC)
Loss aversion in schizophrenia.
Trémeau, Fabien; Brady, Melissa; Saccente, Erica; Moreno, Alexis; Epstein, Henry; Citrome, Leslie; Malaspina, Dolores; Javitt, Daniel
2008-08-01
Loss aversion in decision-making refers to a higher sensitivity to losses than to gains. Loss aversion is conceived as an affective interference in cognitive processes such as judgment and decision-making. Loss aversion in non-risky choices has not been studied in schizophrenia. Forty-two individuals with schizophrenia and 42 non-patient control subjects, matched by gender and age, were randomized to two different scenarios (a buying scenario and a selling scenario). Subjects were asked to evaluate the price of a decorated mug. Schizophrenia subjects were re-tested four weeks later with the other scenario. Contrary to non-patient controls, schizophrenia subjects did not show loss aversion. In the schizophrenia group, absence of loss aversion was correlated with age, duration of illness, number of months in State hospitals, and poorer performance in the Wisconsin Card Sorting Test, but not with current psychopathology and two domains of emotional experience. Absence of loss aversion in schizophrenia represents a deficit in the processing of emotional information during decision-making. It can be interpreted as a lack of integration between the emotional and the cognitive systems, or to a more diffuse and de-differentiated impact of emotional information on decision-making. Future studies should bring more clarity to this question.
Directory of Open Access Journals (Sweden)
ES Nakage
2002-12-01
weighed, desinfected, and then incubated (T=35.5ºC and RH=70%. On the 16th day of incubation, these eggs were transferred to a hatchery maintained at temperature and RH similar to those used in the incubator, where they were kept until hatching. The results showed that the mean number of eggshell pores changed among the three regions of the eggshell and egg weight classes, and also between the physical form of diets. Ingestion of pelleted diet increased eggshell thickness; however, hatchability and water loss percentages remained unchanged.
The relation between Pearson’s correlation coefficient r and Salton’s cosine measure
Egghe, L.; Leydesdorff, L.
2009-01-01
The relation between Pearson's correlation coefficient and Salton's cosine measure is revealed based on the different possible values of the division of the L1-norm and the L2-norm of a vector. These different values yield a sheaf of increasingly straight lines which together form a cloud of points,
Seeley-De Witt coefficients in a Riemann-Cartan manifold
International Nuclear Information System (INIS)
Cognola, G.; Zerbini, S.; Istituto Nazionale di Fisica Nucleare, Povo
1988-01-01
A new derivation of the first two coefficients of the heat kernel expansion for a second-order elliptic differential operator on a Riemann-Cartan manifold with arbitrary torsion is given. The expressions are presented in a very compact and tractable form useful for physical applications. Comparisons with other similar results that appeared in the literature are briefly discussed. (orig.)
Lq-perturbations of leading coefficients of elliptic operators: Asymptotics of eigenvalues
Directory of Open Access Journals (Sweden)
Vladimir Kozlov
2006-01-01
Full Text Available We consider eigenvalues of elliptic boundary value problems, written in variational form, when the leading coefficients are perturbed by terms which are small in some integral sense. We obtain asymptotic formulae. The main specific of these formulae is that the leading term is different from that in the corresponding formulae when the perturbation is small in L∞-norm.
International Nuclear Information System (INIS)
Yao Zhenzhi; Zhu Hongwu; Meng Xianghua; Lue Xing; Shan Wenrui; Tian Bo; Zhang Chunyi
2008-01-01
In this paper, we derive the bilinear form for a variable-coefficient Kadomtsev-Petviashvili-typed equation. Based on the bilinear form, we obtain the Wronskian determinant solution, which is proved to be indeed an exact solution of this equation through the Wronskian technique. In addition, we testify that this equation can be reduced to a Jacobi identity by considering its solution as a Grammian determinant by means of Pfaffian derivative formulae
Wu, Yi; Wang, Chunlin; Sun, Hao; Murphy, Anthony B.; Rong, Mingzhe; Yang, Fei; Chen, Zhexin; Niu, Chunpin; Wang, Xiaohua
2018-04-01
The thermophysical properties, including composition, thermodynamic properties, transport coefficients and net emission coefficients, of thermal plasmas formed from pure iso-C4 perfluoronitrile C4F7N and C4F7N–CO2 mixtures are calculated for temperatures from 300 to 30 000 K and pressures from 0.1 to 20 atm. These gases have received much attention as alternatives to SF6 for use in circuit breakers, due to the low global warming potential and good dielectric properties of C4F7N. Since the parameters of the large molecules formed in the dissociation of C4F7N are unavailable, the partition function and enthalpy of formation were calculated using computational chemistry methods. From the equilibrium composition calculations, it was found that when C4F7N is mixed with CO2, CO2 can capture C atoms from C4F7N, producing CO, since the system consisting of small molecules such as CF4 and CO has lower energy at room temperature. This is in agreement with previous experimental results, which show that CO dominates the decomposition products of C4F7N–CO2 mixtures; it could limit the repeated breaking performance of C4F7N. From the point of view of chemical stability, the mixing ratio of CO2 should therefore be chosen carefully. Through comparison with common arc quenching gases (including SF6, CF3I and C5F10O), it is found that for the temperature range for which electrical conductivity remains low, pure C4F7N has similar ρC p (product of mass density and specific heat) properties to SF6, and higher radiative emission coefficient, properties that are correlated with good arc extinguishing capability. For C4F7N–CO2 mixtures, the electrical conductivity is very close to that of SF6 while the ρC p peak at 7000 K caused by decomposition of CO implies inferior interruption capability to that of SF6. The calculated properties will be useful in arc simulations.
Fukuma, Shingo; Shimizu, Sayaka; Shintani, Ayumi; Kamitani, Tsukasa; Akizawa, Tadao; Fukuhara, Shunichi
2017-09-05
Among aging hemodialysis patients, loss of physical function has become a major issue. We developed and validated a model of predicting loss of physical function among elderly hemodialysis patients. We conducted a cohort study involving maintenance hemodialysis patients ≥65 years of age from the Dialysis Outcomes and Practice Pattern Study in Japan. The derivation cohort included 593 early phase (1996-2004) patients and the temporal validation cohort included 447 late-phase (2005-12) patients. The main outcome was the incidence of loss of physical function, defined as the 12-item Short Form Health Survey physical function score decreasing to 0 within a year. Using backward stepwise logistic regression by Akaike's Information Criteria, six predictors (age, gender, dementia, mental health, moderate activity and ascending stairs) were selected for the final model. Points were assigned based on the regression coefficients and the total score was calculated by summing the points for each predictor. In total, 65 (11.0%) and 53 (11.9%) hemodialysis patients lost their physical function within 1 year in the derivation and validation cohorts, respectively. This model has good predictive performance quantified by both discrimination and calibration. The proportion of the loss of physical function increased sequentially through low-, middle-, and high-score categories based on the model (2.5%, 11.7% and 22.3% in the validation cohort, respectively). The loss of physical function was strongly associated with 1-year mortality [adjusted odds ratio 2.48 (95% confidence interval 1.26-4.91)]. We developed and validated a risk prediction model with good predictive performance for loss of physical function in elderly hemodialysis patients. Our simple prediction model may help physicians and patients make more informed decisions for healthy longevity. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA.
Remifentanil Reduces Blood Loss During Orthognathic Surgery.
Matsuura, Nobuyuki; Okamura, Taiki; Ide, Satoko; Ichinohe, Tatsuya
2017-01-01
Remifentanil is reported to reduce oral tissue blood flow. We performed a retrospective investigation using logistic regression analysis of anesthesia records to investigate whether the use of remifentanil infusion in a balanced anesthesia technique was useful as a primary technique to reduce blood loss during orthognathic surgery. Subjects were 80 patients who underwent Le Fort I osteotomy and sagittal split ramus osteotomy of the mandible. The variables included gender, age, weight, type of maintenance anesthetic, type and dose or infusion rate of opioid, mean systolic blood pressure (SBP-mean), coefficient of variation of systolic blood pressure (CVSBP) during surgery, mean heart rate (HR-mean), duration of surgery, total blood loss, volume of infusion used, amount of local anesthetic used, body temperature, and urine output. Gender, type of maintenance anesthetic, type of opioid, SBP-mean, CVSBP, HR-mean, and duration of surgery were used as candidates for independent variables. Logistic regression analysis was performed for the selected independent variables with the total blood loss as the dependent variable. The factors associated with the reduction of blood loss were the use of remifentanil (odds ratio, 3.112; 95% CI, 1.166-8.307; P = .023) and smaller CVSBP (odds ratio, 2.747; 95% CI, 1.07-7.053; P = .036). Use of remifentanil and smaller CVSBP were associated with a reduction of blood loss during orthognathic surgery.
Partially linear varying coefficient models stratified by a functional covariate
Maity, Arnab; Huang, Jianhua Z.
2012-01-01
We consider the problem of estimation in semiparametric varying coefficient models where the covariate modifying the varying coefficients is functional and is modeled nonparametrically. We develop a kernel-based estimator of the nonparametric
Variable-coefficient nonisospectral Toda lattice hierarchy and its ...
Indian Academy of Sciences (India)
In this paper, a hierarchy of nonisospectral equations with variable coefficients is derived from the ..... from the definitions of Lax integrability and Lax pairs [26] that the variable-coefficient ..... studying which will be the topic for our future study.
Solving Variable Coefficient Fourth-Order Parabolic Equation by ...
African Journals Online (AJOL)
Solving Variable Coefficient Fourth-Order Parabolic Equation by Modified initial guess Variational ... variable coefficient fourth order parabolic partial differential equations. The new method shows rapid convergence to the exact solution.
The Attenuation of Correlation Coefficients: A Statistical Literacy Issue
Trafimow, David
2016-01-01
Much of the science reported in the media depends on correlation coefficients. But the size of correlation coefficients depends, in part, on the reliability with which the correlated variables are measured. Understanding this is a statistical literacy issue.
Multiphoton absorption coefficients in solids: an universal curve
International Nuclear Information System (INIS)
Brandi, H.S.; Araujo, C.B. de
1983-04-01
An universal curve for the frequency dependence of the multiphoton absorption coefficient is proposed based on a 'non-perturbative' approach. Specific applications have been made to obtain two, three, four and five photons absorption coefficient in different materials. Properly scaling of the two photon absorption coefficient and the use of the universal curve yields results for the higher order absorption coefficients in good agreement with the experimental data. (Author) [pt
THE RELATIONSHIP BETWEEN STIFFNESS LOSSES AND LOSSES IN BEARINGS OF ROPE BLOCKS
Directory of Open Access Journals (Sweden)
V. M. Bohomaz
2017-08-01
Full Text Available Purpose. To determine the efficiency of rope blocks, it is necessary to determine the stiffness coefficient of the ropes of blocks, taking into account the classification group of the mechanism and the wrapping angle of a block by a rope. At this one should use well-tested values of the efficiency coefficients of the rope blocks, taking into account the wrapping angle of a block by a rope and the analytically found friction coefficients of the rolling bearings given to the trunnion. Methodology. The work presents the analytical method of determining the coefficient of bearing resistance of the block when it is rotated by both the inner and outer cages, as well as the design scheme of the bearing of the block. Findings. The analysis of the lubrication method effect, the operating mode of the mechanism and the wrapping angle of a block by a rope on losses in bearings was carried out for rope blocks. The corresponding comparative tables of losses are given. Analysis of the obtained calculation results allows us to establish: 1 the main resistance affecting the cable blocks efficiency is the resistance in bearings; 2 the second largest component is the stiffness losses, depending on the operating mode, the wrapping angle of a block by a rope, the type of bearing lubrication; 3 the block efficiency when rotating the inner cage is higher than rotating the outer one by about 3% with thick lubrication and 1M mode; 4 in the sequential location of assemblies with a rolling bearing, it is necessary to strive for the design of the assembly in which the inner cage rotates; 5 with the number of blocks up to 5, one can use the recommended definitions of block bearings in the literature with an error in the efficiency value of up to 10%. Originality. The authors obtained values of resistances in the rolling bearings of the rope blocks and stiffness losses due to the girth of the block by the rope. In this case, dependences were used to determine the coefficient
... The doses of thyroid hormone used to treat hypothyroidism (underactive thyroid) don’t harm bone and shouldn’t be cause for concern. Only high doses, used for thyroid cancer treatment, can cause bone loss. High doses or long- ...
... can allow many infants to develop normal language skills without delay. In infants born with hearing loss, ... therapy allow many children to develop normal language skills at the same age as their peers with ...
Hearing Loss: Screening Newborns
... of this page please turn JavaScript on. Feature: Hearing Loss Screening Newborns Past Issues / Spring 2015 Table ... deafness, which account for most cases. Screening Newborns' Hearing Now Standard In 1993, children born in the ...
Harmonic Maass forms and mock modular forms
Bringmann, Kathrin; Ono, Ken
2017-01-01
Modular forms and Jacobi forms play a central role in many areas of mathematics. Over the last 10-15 years, this theory has been extended to certain non-holomorphic functions, the so-called "harmonic Maass forms". The first glimpses of this theory appeared in Ramanujan's enigmatic last letter to G. H. Hardy written from his deathbed. Ramanujan discovered functions he called "mock theta functions" which over eighty years later were recognized as pieces of harmonic Maass forms. This book contains the essential features of the theory of harmonic Maass forms and mock modular forms, together with a wide variety of applications to algebraic number theory, combinatorics, elliptic curves, mathematical physics, quantum modular forms, and representation theory.
RELAP5 Model Description and Validation for the BR2 Loss-of-Flow Experiments
Energy Technology Data Exchange (ETDEWEB)
Licht, J. R. [Argonne National Lab. (ANL), Argonne, IL (United States); Dionne, B. [Argonne National Lab. (ANL), Argonne, IL (United States); Van den Branden, G. [Argonne National Lab. (ANL), Argonne, IL (United States); Sikik, E. [Argonne National Lab. (ANL), Argonne, IL (United States); Koonen, E. [Argonne National Lab. (ANL), Argonne, IL (United States)
2015-07-01
This paper presents a description of the RELAP5 model, the calibration method used to obtain the minor loss coefficients from the available hydraulic data and the LOFA simulation results compared to the 1963 experimental tests for HEU fuel.
International Nuclear Information System (INIS)
Bronca, G.; Fevrier, A.; Genevey, P.; Perot, J.
1974-01-01
After a recall of the theory of losses in type 11 superconductors and review of recent work on this topic, the characteristics of what should be an ideal conductor for a pulsed magnet are given. The requirements of pulsed magnets for high energy physics are reviewed and total losses for a 1000 GeV synchrotron estimated. Finally, recent results of prototypes are reported along with the projects of superconducting synchrotron accelerators through the world. (author)
Directory of Open Access Journals (Sweden)
İdil Ünal
2014-06-01
Full Text Available Female androgenetic alopecia is the commonest cause of hair loss in women. It is characterized by a diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline and a characteristic pattern distribution in genetically predisposed women. Because of the uncertain relationship with the androgens Female Pattern Hair Loss (FPHL is the most preferred definition of the condition. This review has been focused on the clinical features, diagnosis and treatment alternatives of FPHL.
Corner diffraction coefficients for the quarter plane
DEFF Research Database (Denmark)
Hansen, Thorkild B.
1991-01-01
that the corner current for the right-angled corner, illuminated from a forward direction, consists mainly of two edge waves propagating along the edges forming the corner. Analytical expressions for these edge wave currents are constructed from the numerical results. A corner diffracted field is calculated...
On the Occurrence of Standardized Regression Coefficients Greater than One.
Deegan, John, Jr.
1978-01-01
It is demonstrated here that standardized regression coefficients greater than one can legitimately occur. Furthermore, the relationship between the occurrence of such coefficients and the extent of multicollinearity present among the set of predictor variables in an equation is examined. Comments on the interpretation of these coefficients are…
An Investigation of the Sampling Distribution of the Congruence Coefficient.
Broadbooks, Wendy J.; Elmore, Patricia B.
This study developed and investigated an empirical sampling distribution of the congruence coefficient. The effects of sample size, number of variables, and population value of the congruence coefficient on the sampling distribution of the congruence coefficient were examined. Sample data were generated on the basis of the common factor model and…
Asymmetrical slip propensity: required coefficient of friction.
Seo, Jung-suk; Kim, Sukwon
2013-07-31
Most studies in performing slips and falls research reported their results after the ipsilateral leg of subjects (either right foot or left foot) was guided to contact the contaminated floor surface although many studies indicated concerns for asymmetries of legs in kinematic or kinetic variables. Thus, the present study evaluated if dominant leg's slip tendency would be different from non-dominant leg's slip tendency by comparing the Required Coefficient of Friction (RCOF) of the two lower limbs. Forty seven health adults participated in the present study. RCOF was measured when left or right foot of subjects contacted the force platforms respectively. Paired t-test was performed to test if RCOF and heel velocity (HCV) of dominant legs was different from that of non-dominant legs. It was suggested that the asymmetry in RCOFs and HCV between the two lower limbs existed. The RCOFs of non-dominant legs were higher than that of dominant legs. The results indicated that asymmetry in slip propensity, RCOF, was existed in lower extremity. The results from the study suggested that it would be benefit to include a variable, such as asymmetry, in slips and falls research.
Coefficient of Friction of Human Corneal Tissue.
Wilson, Tawnya; Aeschlimann, Rudolf; Tosatti, Samuele; Toubouti, Youssef; Kakkassery, Joseph; Osborn Lorenz, Katherine
2015-09-01
A novel property evaluation methodology was used to determine the elusive value for the human corneal coefficient of friction (CoF). Using a microtribometer on 28 fresh human donor corneas with intact epithelia, the CoF was determined in 4 test solutions (≥5 corneas/solution): tear-mimicking solution (TMS) in borate-buffered saline (TMS-PS), TMS in phosphate-buffered saline (TMS-PBS), TMS with HEPES-buffered saline (TMS-HEPES), and tear-like fluid in PBS (TLF-PBS). Mean (SD) CoF values ranged from 0.006 to 0.015 and were 0.013 (0.010) in TMS-PS, 0.006 (0.003) in TMS-PBS, 0.014 (0.005) in TMS-HEPES, and 0.015 (0.009) in TLF-PBS. Statistically significant differences were shown for TMS-PBS versus TLF (P = 0.0424) and TMS-PBS versus TMS-HEPES (P = 0.0179), but not for TMS-PBS versus TMS-PS (P = 0.2389). Successful measurement of the fresh human corneal tissue CoF was demonstrated, with values differing in the evaluated buffer solutions, within this limited sample size.
Local diffusion coefficient determination: Mediterranean Sea experiments
International Nuclear Information System (INIS)
Bacciola, D.; Borghini, M.; Cannarsa, S.
1993-10-01
The Mediterranean is a semi/enclosed basin characterized by the presence of channels and straits influencing the circulation, temperature and salinity fields. The tides generally have amplitudes of the order of 10 cm and velocities of few cm/s. Conversely, the wind forced circulation is very strong and can assume velocity values of 1 m/s at the sea surface. The temperature and salinity fields have a high temporal and spatial variability, because of many mixing processes existing in the sea. For example, the waters coming from the Provencal basin meet those waters coming from the Tyrrhenian Sea in the eastern Ligurian Sea, creating meanders and eddies. Local runoff influences significantly the coastal circulation. This paper describes diffusion experiments carried out in this complex environment. The experimental apparatus for the detection of the fluorescine released at sea was composed by two Turner mod. 450 fluorometres. During the experiments, temperature and salinity vertical profiles were measured by using a CTD; meteorological data were acquired on a dinghy. The positioning was obtained by means of a Motorola system, having a precision of about 1 meter. The experiments were carried out under different stratification and wind conditions. From data analysis it was found that the horizontal diffusion coefficient does not depend on time or boundary conditions. The role of stratification is important with regard to vertical displacement of the dye. However, its role with regard to vertical diffusion cannot be assessed with the actual experimental apparatus
Assessment of satellite derived diffuse attenuation coefficients ...
Optical data collected in coastal waters off South Florida and in the Caribbean Sea between January 2009 and December 2010 were used to evaluate products derived with three bio-optical inversion algorithms applied to MOIDS/Aqua, MODIS/Terra, and SeaWiFS satellite observations. The products included the diffuse attenuation coefficient at 490 nm (Kd_490) and for the visible range (Kd_PAR), and euphotic depth (Zeu, corresponding to 1% of the surface incident photosynthetically available radiation or PAR). Above-water hyperspectral reflectance data collected over optically shallow waters of the Florida Keys between June 1997 and August 2011 were used to help understand algorithm performance over optically shallow waters. The in situ data covered a variety of water types in South Florida and the Caribbean Sea, ranging from deep clear waters, turbid coastal waters, and optically shallow waters (Kd_490 range of ~0.03 – 1.29m-1). An algorithm based on Inherent Optical Properties (IOPs) showed the best performance (RMSD turbidity or shallow bottom contamination. Similar results were obtained when only in situ data were used to evaluate algorithm performance. The excellent agreement between satellite-derived remote sensing reflectance (Rrs) and in situ Rrs suggested that
Townsend coefficients of gases in avalanche counters
International Nuclear Information System (INIS)
Brunner, G.
1978-01-01
Though much work has been done by many authors in the last few years in the development and application of avalanche counters for ion radiation, it is based upon values of the Townsend coefficients as the essential gas parameter, which were determined many years ago for much lower reduced field strengths F/p than prevail in such counters. Therefore absolute determinations of α in vapours of methyl alcohol, cyclohexane, acetone, and n-heptene were performed under original conditions of avalanche counters. The values obtained do not differ by more than 30%-50% from the former values indeed, extrapolated over F/p for the first three mentioned substances, but the amounts of A and B in the usual representation α/p=A exp(-B(F/p)) are much greater for the stronger reduced fields. This is of importance for such counter properties as the dependence of pulse heights on pressure, voltage, electrode distance etc., which are governed by other combinations of A and B than α/p itself. A comparison of results for different ionic radiations shows a marked influence of the primary ionization density along the particle tracks which is hard to explain. (Auth.)
Volatilization: a soil degassing coefficient for iodine
International Nuclear Information System (INIS)
Sheppard, M.I.; Thibault, D.H.; Smith, P.A.; Hawkins, J.L.
1994-01-01
Iodine, an element essential to some animals, is ubiquitous in the biosphere. Unlike other metallic elements, molecular I is volatile, and other inorganic species present in aerated soils, such as I - and IO 3 - , may also volatilize as hydrides, hydrogen iodide (HI), or hydrogen iodates (HIO 3 , HIO 4 ). Methyl iodide has been measured in soils, and it is likely evolved from soils and plants. The long-lived radioisotope 129 I is abundant in nuclear wastes, and its high solubility in groundwater makes it an important element in the performance assessment of underground disposal facilities. Overestimates of soil I residence half-times by traditional foodchain models may be due to underestimation of volatilization. Field and lysimeter experiments over a 3-year period, and direct trapping experiments in the laboratory are reported. The results, combined with values from the literature, indicate the soil I degassing coefficient for a wide range of soil types, vegetated and bare, wet and dry, is lognormally distributed with a geometric mean of 2.1 x 10 -2 year -1 , a range of 1.8 x 10 -4 to 3.1 year -1 and a geometric standard deviation of 3.0. The results of a biosphere model simulation including degassing reduces soil I concentrations fivefold and increases air concentrations 25-fold at steady state, compared to simulations without degassing. (author)
DiMarco, Gabriella; McMichael, Amy
2017-07-01
INTRODUCTION: Hair loss is a common complaint seen in dermatology clinics. From frustration and attempts at self-help, patients with hair loss may present to the dermatologist with false beliefs, or myths, about the causes of their condition and what treatments are effective. METHODS: We identified 12 common myths about hair loss, categorized as myths about minoxidil treatment, vitamin and mineral supplements, natural topical treatments, and hair care practices. We performed a PubMed search to find evidence to support or refute each myth. RESULTS: We found that there is little evidence to support many of these common hair loss myths. In some cases, randomized controlled trials have investigated the effects of particular therapies and point to the effectiveness of certain hair loss treatments. DISCUSSION: In many cases, there have not been sufficient randomized controlled trials to evaluate the effect of different therapies and hair care practices on hair loss. It is best to guide patients toward treatments with a long track record of efficacy and away from those where little is known scientifically. J Drugs Dermatol. 2017;16(7):690-694..
Schwenke, David W.; Jaffe, Richard L.; Chaban, Galina M.
2016-01-01
We have generated accurate global potential energy surfaces for CO+Ar and CO+O that correlate with atom-diatom pairs in their ground electronic states based on extensive ab initio electronic structure calculations and used these potentials in quasi-classical trajectory nuclear dynamics calculations to predict the thermal dissociation rate coefficients over 5000- 35000 K. Our results are not compatible with the 20-45 year old experimental results. For CO + Ar we obtain fairly good agreement with the experimental rate coefficients of Appleton et al. (1970) and Mick and Roth (1993), but our computed rate coefficients exhibit a stronger temperature dependence. For CO + O our dissociation rate coefficient is in close agreement with the value from the Park model, which is an empirical adjustment of older experimental results. However, we find the rate coefficient for CO + O is only 1.5 to 3.3 times larger than CO + Ar over the temperature range of the shock tube experiments (8000-15,000 K). The previously accepted value for this rate coefficient ratio is 15, independent of temperature. We also computed the rate coefficient for the CO + O ex- change reaction which forms C + O2. We find this reaction is much faster than previously believed and is the dominant process in the removal of CO at temperatures up to 16,000 K. As a result, the dissociation of CO is accomplished in two steps (react to form C+O2 and then O2 dissociates) that are endothermic by 6.1 and 5.1 eV, instead of one step that requires 11.2 eV to break the CO bond.
Primary culprit for tooth loss!!
Directory of Open Access Journals (Sweden)
Sailavanya Nuvvula
2016-01-01
Full Text Available Aim: In order to facilitate planning for dental health services and to progress strategies to continue the reduction in tooth loss, it is important to identify the factors that result in such loss. therefore the aim of the study is to investigate the major cause for tooth extraction. Objective: to examine whether the major reason for tooth extraction is dental caries or periodontal disease. Materials and Methods: The study is carried out among the dental practitioners in our district. A questionnaire containing 10 items was distributed to the dental practitioners, which included age, gender, no of teeth indicated for extraction, the reason for extraction, and the periodontal parameters that are involved with the extracted tooth and were requested to complete the form on every extraction they were to undertake. the study form was collected at the end of the study period and data was subjected to statistical analysis. Results: A total of 502 patients were enrolled during the study period, and a total of 1055 teeth were extracted for several reasons. we found that 51.14%extractions are due to dental caries in case of 20-30years age groups, which is more when compared to tooth loss due to periodontal diseases in this age group. whereas in case of >40years of age group periodontal diseases account for 54.11%, and dental caries accounts for only 29.11%. Showing more teeth were lost due to periodontal disease. Conclusion: therefore we concluded that, caries is the dominant reason for extraction in patients with 20–30 years of age while periodontal disease accounts for the majority of tooth extraction in patients older than 40 years.
DEFF Research Database (Denmark)
Skyum, Sven
1978-01-01
This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete.......This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete....
Directory of Open Access Journals (Sweden)
Gülfen TUNA
2013-03-01
Full Text Available The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM is valid on the ISE. In addition, it is obtained that the power of downside beta coefficient is higher than traditional beta coefficient on explaining the return changes. Therefore, it can be said that the downside beta is superior to traditional beta in the ISE for chosen period.
Allie-Ebrahim, Tariq; Zhu, Qingyu; Bräuer, Pierre; Moggridge, Geoff D; D'Agostino, Carmine
2017-06-21
The Maxwell-Stefan model is a popular diffusion model originally developed to model diffusion of gases, which can be considered thermodynamically ideal mixtures, although its application has been extended to model diffusion in non-ideal liquid mixtures as well. A drawback of the model is that it requires the Maxwell-Stefan diffusion coefficients, which are not based on measurable quantities but they have to be estimated. As a result, numerous estimation methods, such as the Darken model, have been proposed to estimate these diffusion coefficients. However, the Darken model was derived, and is only well defined, for binary systems. This model has been extended to ternary systems according to two proposed forms, one by R. Krishna and J. M. van Baten, Ind. Eng. Chem. Res., 2005, 44, 6939-6947 and the other by X. Liu, T. J. H. Vlugt and A. Bardow, Ind. Eng. Chem. Res., 2011, 50, 10350-10358. In this paper, the two forms have been analysed against the ideal ternary system of methanol/butan-1-ol/propan-1-ol and using experimental values of self-diffusion coefficients. In particular, using pulsed gradient stimulated echo nuclear magnetic resonance (PGSTE-NMR) we have measured the self-diffusion coefficients in various methanol/butan-1-ol/propan-1-ol mixtures. The experimental values of self-diffusion coefficients were then used as the input data required for the Darken model. The predictions of the two proposed multicomponent forms of this model were then compared to experimental values of mutual diffusion coefficients for the ideal alcohol ternary system. This experimental-based approach showed that the Liu's model gives better predictions compared to that of Krishna and van Baten, although it was only accurate to within 26%. Nonetheless, the multicomponent Darken model in conjunction with self-diffusion measurements from PGSTE-NMR represents an attractive method for a rapid estimation of mutual diffusion in multicomponent systems, especially when compared to exhaustive
Oxygen transport in waterlogged soils, Part II. Diffusion coefficients
International Nuclear Information System (INIS)
Obando Moncayo, F.H.
2004-01-01
Several equations are available for Oxygen Transport in Waterlogged Soils and have been used for soils and plants. All of them are some form of first Fick's law as given by dQ = - DA(dc/dx)/dt. This equation illustrates some important aspects of aeration in waterlogged soils; first, D is a property of the medium and the gas, and is affected by temperature T. Likewise, the amount of diffusing substance dQ in dt is a direct function of the cross sectional area A and inversely proportional to the distance x. In fact, increasing the water content of air-dry soil, drastically decreases A and creates a further resistance for the flow of oxygen through water films around root plants, soil micro organisms and soil aggregates. The solid phase is also limiting the cross-section of surface of the free gaseous diffusion and the length and tortuosity of diffusion path in soil. In most of cases, soil gas porosity and tortuosity of soil voids are expressed in the equations of diffusion as a broad 'diffusion coefficient' (apparent coefficient diffusion). The process of soil respiration is complicated, involves many parameters, and is difficult to realistically quantify. With regard to the oxygen supply, it is convenient to distinguish macro and micro models, and hence, the flux of oxygen is assumed to have two steps. The first step is related to oxygen diffusion from the atmosphere and the air-filled porosity. The second step is related to the oxygen diffusion through water-films in and around plant roots, soil micro organisms and aggregates. Because of these models we obtain coefficients of macro or micro diffusion, rates of macro or micro diffusion, etc. In the macro diffusion process oxygen is transferred in the soil profile, mainly from the soil surface to a certain depth of the root zone, while micro diffusion deals with the flux over very short distances. Both processes, macro and micro diffusion are highly influenced by soil water content. Of course, if water is added to
Transfer coefficients for terrestrial foodchain: their derivation and limitations
International Nuclear Information System (INIS)
Ng, Y.C.; Colsher, C.S.; Thompson, S.E.
1979-01-01
Transfer coefficients to predict the passage of isotopes from the environment to terrestrial foods have been derived for various radionuclides of importance in the nuclear fuel cycle. These data update and extend previously recommended handbook values. We derive transfer coefficients to terrestrial foods and describe the systematics of the derived transfer coefficients. Suggestions are offered for changes in the values of transfer coefficients to terrestrial foods that now appear in federal regulatory guides. Deficiencies in our present knowledge concerning transfer coefficients and limitations in the use of these values to ensure compliance with radiation protection standards are discussed
Directory of Open Access Journals (Sweden)
Natalya P. Anoshkina
2018-06-01
Full Text Available The paper is devoted to the problem of credit loss management topical for modern Russian science and banking practice. The bank’s lending activity is an integral and the most profitable sphere of banking activity. Banks need to take credit risks inherent in their core business and minimize their impact through the establishment of advanced risk management systems. The study, reflected in the present paper, has been conducted in order to determine approaches to the organization of credit loss management in banking. Analysis of the system of management of credit risks and credit losses has shown that they have different scope, object and purpose. In this connection, there is an objective necessity to create a special subsystem for the management of credit losses in banks. On the basis of common bank approaches to credit risk management, the paper develops models of credit loss management: a multi-level management model in the area of ‘operational-tactical-strategic management’ and a functional management model in the area of ‘technology-execution-control’. These models are important for the modern theory and practice of banking, as they allow the bank to manage credit losses on the entire time horizon of the management process, thus opening a wide range of opportunities for the creation and implementation of large-scale programs, as well as specific techniques. This study allows drawing a conclusion about the need to consider control credit losses as a strictly regulated multi-level process, in which each division is assigned with specific objectives, tasks, functions, formally enshrined in the relevant lists, job descriptions and other legal documents.
Transport coefficients of strongly interacting matter
International Nuclear Information System (INIS)
Heckmann, Klaus
2011-01-01
In this thesis, we investigate the dissipative transport phenomena of strongly interacting matter. The special interest is in the shear viscosity and its value divided by entropy density. The performed calculations are based on effective models for Quantum Chromodynamics, mostly focused on the 2-flavor Nambu-Jona-Lasinio model. This allows us to study the hadronic sector as well as the quark sector within one single model. We expand the models up to next-to-leading order in inverse numbers of colors. We present different possibilities of calculating linear transport coefficients and give an overview over qualitative properties as well as over recent ideas concerning ideal fluids. As present methods are not able to calculate the quark two-point function in Minkowski space-time in the self-consistent approximation scheme of the Nambu-Jona-Lasinio model, a new method for this purpose is developed. This self-energy parametrization method is applied to the expansion scheme, yielding the quark spectral function with meson back-coupling effects. The usage of this spectral function in the transport calculation is only one result of this work. We also test the application of different transport approaches in the NJL model, and find an interesting behavior of the shear viscosity at the critical end point of the phase diagram. We also use the NJL model to calculate the viscosity of a pion gas in the dilute regime. After an analysis of other models for pions and their interaction, we find that the NJL-result leads to an important modification of transport properties in comparison with the calculations which purely rely on pion properties in the vacuum. (orig.)
Cubic metaplectic forms and theta functions
Proskurin, Nikolai
1998-01-01
The book is an introduction to the theory of cubic metaplectic forms on the 3-dimensional hyperbolic space and the author's research on cubic metaplectic forms on special linear and symplectic groups of rank 2. The topics include: Kubota and Bass-Milnor-Serre homomorphisms, cubic metaplectic Eisenstein series, cubic theta functions, Whittaker functions. A special method is developed and applied to find Fourier coefficients of the Eisenstein series and cubic theta functions. The book is intended for readers, with beginning graduate-level background, interested in further research in the theory of metaplectic forms and in possible applications.
Estimation of uranium forms in oceanic water
International Nuclear Information System (INIS)
Krylov, O.T.; Novikov, P.D.; Nesterova, M.P.
1985-01-01
A critical consideration is given to the notions about uranium forms in ocean water. To estimate uranium forms a model is suggested which takes into account possjble formation of complexes of uranyl ions and ocean water anions Cl - , SO 4 2- , CO 3 2- , HCO 3 - , OH - , F - . The available published data are used to estimate necessary thermodynamic stability constants of the complexes, activity coefficients and concentration of componenets. The thermodynamic calculation shows that uranium hydroxocomplex compounds UO 2 (OH) 4 2- (99.17%) and UO 2 (OH) 3 - (083%) are the most probable uranium forms in ocear water of 34.3% salinity at 25 deg C and 1 atm pressure
Benchmarking of direct and indirect friction tests in micro forming
DEFF Research Database (Denmark)
Eriksen, Rasmus Solmer; Calaon, Matteo; Arentoft, M.
2012-01-01
The sizeable increase in metal forming friction at micro scale, due to the existence of size effects, constitutes a barrier to the realization of industrial micro forming processes. In the quest for improved frictional conditions in micro scale forming operations, friction tests are applied...... to qualify the tribological performance of the particular forming scenario. In this work the application of a simulative sliding friction test at micro scale is studied. The test setup makes it possible to measure the coefficient of friction as a function of the sliding motion. The results confirm a sizeable...... increase in the coefficient of friction when the work piece size is scaled down. © (2012) Trans Tech Publications....
Hijikata, Hayato; Kozawa, Takahiro; Tagawa, Seiichi; Takei, Satoshi
2009-06-01
A bottom extreme-ultraviolet-sensitive coating (BESC) for evaluation of the absorption coefficients of ultrathin films such as extreme ultraviolet (EUV) resists was developed. This coating consists of a polymer, crosslinker, acid generator, and acid-responsive chromic dye and is formed by a conventional spin-coating method. By heating the film after spin-coating, a crosslinking reaction is induced and the coating becomes insoluble. A typical resist solution can be spin-coated on a substrate covered with the coating film. The evaluation of the linear absorption coefficients of polymer films was demonstrated by measuring the EUV absorption of BESC substrates on which various polymers were spin-coated.
Summary of existing information on gamma-ray and X-ray attenuation coefficients of solutions
DEFF Research Database (Denmark)
Singh, K.; Gerward, Leif
2002-01-01
Accurate values of X-ray and gamma-ray attenuation coefficients of different chemicals are required in spectrometry as well as in many other scientific, engineering and medical disciplines involving photon radiation. The current state of knowledge of experimental and theoretical gamma-ray and X-r......-ray attenuation coefficients in aqueous solutions of salts is presented and exemplified by recent work. The results presented provide a basis for studying X-ray and gamma-ray photon interactions with ions in solution (hydrated ions) rather than ion compounds in solid form....
International Nuclear Information System (INIS)
Moeller, S.V.
1982-09-01
The determination of the heat transfer coefficient of the pins of the Spallation Neutron Source is a very important problem for the development of this facility, as data for thermal and structural studies. For this purpose, a test apparatus was built, in scale 1:1, for the simulation of the thermal and hydraulical conditions of the Neutron Source. This apparatus is a pin bank, with one of the pins electrically heated. Performance of measurements gave the values for the heat transfer coefficient, here presented in the Nusselt Number form, and its local distribution. Results show the linear dependence of Nusselt Number on Reynolds Number, for a constant heat production. (orig.) [de
Gradient-based estimation of Manning's friction coefficient from noisy data
Calo, Victor M.
2013-01-01
We study the numerical recovery of Manning\\'s roughness coefficient for the diffusive wave approximation of the shallow water equation. We describe a conjugate gradient method for the numerical inversion. Numerical results for one-dimensional models are presented to illustrate the feasibility of the approach. Also we provide a proof of the differentiability of the weak form with respect to the coefficient as well as the continuity and boundedness of the linearized operator under reasonable assumptions using the maximal parabolic regularity theory. © 2012 Elsevier B.V. All rights reserved.