International Nuclear Information System (INIS)
Leont'ev, K.L.
1981-01-01
Known theoretical and empirical formulae are considered for the difference in specific heats at constant pressure and volume. On the basis of the Grunaiser law on the ratio of specific heat to thermal expansion and on the basis of the correlation proposed by the author, between this ratio and average velocity of elastic waves obtained in a new expression for the difference in specific heats and determined are conditions at which empiric Nernst-Lindeman equation can be considered to be strict. Results of calculations for metals with fcc lattice are presented
Calculation of magnetic hyperfine constants
International Nuclear Information System (INIS)
Bufaical, R.F.; Maffeo, B.; Brandi, H.S.
1975-01-01
The magnetic hyperfine constants of the V sub(K) center in CaF 2 , SrF 2 and BaF 2 have been calculated assuming a phenomenological model, based on the F 2 - 'central molucule', to describe the wavefunction of the defect. Calculations have shown that introduction of a small degree of covalence, between this central molecule and neighboring ions, is necessary to improve the electronic structure description of the defect. It was also shown that the results for the hyperfine constants are strongly dependent on the relaxations of the ions neighboring the central molecule; these relaxations have been determined by fitting the experimental data. The present results are compared with other previous calculations where similar and different theoretical methods have been used
Arrhenius Rate: constant volume burn
Energy Technology Data Exchange (ETDEWEB)
Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-12-06
A constant volume burn occurs for an idealized initial state in which a large volume of reactants at rest is suddenly raised to a high temperature and begins to burn. Due to the uniform spatial state, there is no fluid motion and no heat conduction. This reduces the time evolu tion to an ODE for the reaction progress variable. With an Arrhenius reaction rate, two characteristics of thermal ignition are illustrated: induction time and thermal runaway. The Frank-Kamenetskii approximation then leads to a simple expression for the adiabatic induction time. For a first order reaction, the analytic solution is derived and used to illustrate the effect of varying the activation temperature; in particular, on the induction time. In general, the ODE can be solved numerically. This is used to illustrate the effect of varying the reaction order. We note that for a first order reaction, the time evolution of the reaction progress variable has an exponential tail. In contrast, for a reaction order less than one, the reaction completes in a nite time. The reaction order also affects the induction time.
International Nuclear Information System (INIS)
Plechaty, E.F.; Cullen, D.E.; Howerton, R.J.; Kimlinger, J.R.
1975-01-01
As of February 3, 1975, 175 neutron group constants had been derived from the Evaluated Nuclear Data Library (ENDL) at LLL. In this volume, tables and graphs of the constants are presented along with the conventions used in their preparation. (U.S.)
Analysis of the chemical equilibrium of combustion at constant volume
Directory of Open Access Journals (Sweden)
Marius BREBENEL
2014-04-01
Full Text Available Determining the composition of a mixture of combustion gases at a given temperature is based on chemical equilibrium, when the equilibrium constants are calculated on the assumption of constant pressure and temperature. In this paper, an analysis of changes occurring when combustion takes place at constant volume is presented, deriving a specific formula of the equilibrium constant. The simple reaction of carbon combustion in pure oxygen in both cases (constant pressure and constant volume is next considered as example of application, observing the changes occurring in the composition of the combustion gases depending on temperature.
Daylight calculations using constant luminance curves
Energy Technology Data Exchange (ETDEWEB)
Betman, E. [CRICYT, Mendoza (Argentina). Laboratorio de Ambiente Humano y Vivienda
2005-02-01
This paper presents a simple method to manually estimate daylight availability and to make daylight calculations using constant luminance curves calculated with local illuminance and irradiance data and the all-weather model for sky luminance distribution developed in the Atmospheric Science Research Center of the University of New York (ARSC) by Richard Perez et al. Work with constant luminance curves has the advantage that daylight calculations include the problem's directionality and preserve the information of the luminous climate of the place. This permits accurate knowledge of the resource and a strong basis to establish conclusions concerning topics related to the energy efficiency and comfort in buildings. The characteristics of the proposed method are compared with the method that uses the daylight factor. (author)
Parallel computational in nuclear group constant calculation
International Nuclear Information System (INIS)
Su'ud, Zaki; Rustandi, Yaddi K.; Kurniadi, Rizal
2002-01-01
In this paper parallel computational method in nuclear group constant calculation using collision probability method will be discuss. The main focus is on the calculation of collision matrix which need large amount of computational time. The geometry treated here is concentric cylinder. The calculation of collision probability matrix is carried out using semi analytic method using Beckley Naylor Function. To accelerate computation speed some computer parallel used to solve the problem. We used LINUX based parallelization using PVM software with C or fortran language. While in windows based we used socket programming using DELPHI or C builder. The calculation results shows the important of optimal weight for each processor in case there area many type of processor speed
Biased Brownian dynamics for rate constant calculation.
Zou, G; Skeel, R D; Subramaniam, S
2000-01-01
An enhanced sampling method-biased Brownian dynamics-is developed for the calculation of diffusion-limited biomolecular association reaction rates with high energy or entropy barriers. Biased Brownian dynamics introduces a biasing force in addition to the electrostatic force between the reactants, and it associates a probability weight with each trajectory. A simulation loses weight when movement is along the biasing force and gains weight when movement is against the biasing force. The sampl...
GRUCAL, a computer program for calculating macroscopic group constants
International Nuclear Information System (INIS)
Woll, D.
1975-06-01
Nuclear reactor calculations require material- and composition-dependent, energy averaged nuclear data to describe the interaction of neutrons with individual isotopes in material compositions of reactor zones. The code GRUCAL calculates these macroscopic group constants for given compositions from the material-dependent data of the group constant library GRUBA. The instructions for calculating group constants are not fixed in the program, but will be read at the actual execution time from a separate instruction file. This allows to accomodate GRUCAL to various problems or different group constant concepts. (orig.) [de
DEFF Research Database (Denmark)
Pawlowski, F; Jorgensen, P; Olsen, Jeppe
2002-01-01
A detailed study is carried out of the accuracy of molecular equilibrium geometries obtained from least-squares fits involving experimental rotational constants B(0) and sums of ab initio vibration-rotation interaction constants alpha(r)(B). The vibration-rotation interaction constants have been...... calculated for 18 single-configuration dominated molecules containing hydrogen and first-row atoms at various standard levels of ab initio theory. Comparisons with the experimental data and tests for the internal consistency of the calculations show that the equilibrium structures generated using Hartree......-Fock vibration-rotation interaction constants have an accuracy similar to that obtained by a direct minimization of the CCSD(T) energy. The most accurate vibration-rotation interaction constants are those calculated at the CCSD(T)/cc-pVQZ level. The equilibrium bond distances determined from these interaction...
Quantum mechanical methods for calculation of force constants
International Nuclear Information System (INIS)
Mullally, D.J.
1985-01-01
The focus of this thesis is upon the calculation of force constants; i.e., the second derivatives of the potential energy with respect to nuclear displacements. This information is useful for the calculation of molecular vibrational modes and frequencies. In addition, it may be used for the location and characterization of equilibrium and transition state geometries. The methods presented may also be applied to the calculation of electric polarizabilities and infrared and Raman vibrational intensities. Two approaches to this problem are studied and evaluated: finite difference methods and analytical techniques. The most suitable method depends on the type and level of theory used to calculate the electronic wave function. Double point displacement finite differencing is often required for accurate calculation of the force constant matrix. These calculations require energy and gradient calculations on both sides of the geometry of interest. In order to speed up these calculations, a novel method is presented that uses geometry dependent information about the wavefunction. A detailed derivation for the analytical evaluation of force constants with a complete active space multiconfiguration self consistent field wave function is presented
Semiclassical Calculation of Reaction Rate Constants for Homolytical Dissociations
Cardelino, Beatriz H.
2002-01-01
There is growing interest in extending organometallic chemical vapor deposition (OMCVD) to III-V materials that exhibit large thermal decomposition at their optimum growth temperature, such as indium nitride. The group III nitrides are candidate materials for light-emitting diodes and semiconductor lasers operating into the blue and ultraviolet regions. To overcome decomposition of the deposited compound, the reaction must be conducted at high pressures, which causes problems of uniformity. Microgravity may provide the venue for maintaining conditions of laminar flow under high pressure. Since the selection of optimized parameters becomes crucial when performing experiments in microgravity, efforts are presently geared to the development of computational OMCVD models that will couple the reactor fluid dynamics with its chemical kinetics. In the present study, we developed a method to calculate reaction rate constants for the homolytic dissociation of III-V compounds for modeling OMCVD. The method is validated by comparing calculations with experimental reaction rate constants.
Calculation of hyperfine structure constants of small molecules using
Indian Academy of Sciences (India)
The Z-vector method in the relativistic coupled-cluster framework is employed to calculate the parallel and perpendicular components of the magnetic hyperfine structure constant of a few small alkaline earth hydrides (BeH, MgH, and CaH) and fluorides (MgF and CaF). We have compared our Z-vector results with the values ...
Ab initio calculation of hyperfine splitting constants of molecules
Ohta, K.; Nakatsuji, H.; Hirao, K.; Yonezawa, T.
1980-08-01
Hyperfine splitting (hfs) constants of molecules, methyl, ethyl, vinyl, allyl, cyclopropyl, formyl, O3-, NH2, NO2, and NF2 radicals have been calculated by the pseudo-orbital (PO) theory, the unrestricted HF (UHF), projected UHF (PUHF) and single excitation (SE) CI theories. The pseudo-orbital (PO) theory is based on the symmetry-adapted-cluster (SAC) expansion proposed previously. Several contractions of the Gaussian basis sets of double-zeta accuracy have been examined. The UHF results were consistently too large to compare with experiments and the PUHF results were too small. For molecules studied here, the PO theory and SECI theory gave relatively close results. They were in fair agreement with experiments. The first-order spin-polarization self-consistency effect, which was shown to be important for atoms, is relatively small for the molecules. The present result also shows an importance of eliminating orbital-transformation dependence from conventional first-order perturbation calculations. The present calculations have explained well several important variations in the experimental hfs constants.
Can we calculate the fundamental dimensionless constants of physics
International Nuclear Information System (INIS)
Barut, A.O.
1987-07-01
We review some dynamical models to calculate the dimensionless constants α=e 2 /4πε 0 (h/2π)c, β=M p /m e (or β'=m μ /m e ), γ=G Fermi m e 2 /c(h/2π) 3 and δ=G Newton m e 2 /(e 2 /4πε 0 ) which are associated with the four different manifestations (electromagnetic, strong, weak and gravitational) of a possible single interaction. (author). 15 refs
The Handling of Constant Volumes of Various Concentrations of ...
African Journals Online (AJOL)
The Handling of Constant Volumes of Various Concentrations of Seawater by the Jackass Penguin Spheniscus Demersus. T Erasmus. Abstract. This paper reports on the effects of varying the concentration of sea water dosed at a rate of 10% of body mass on the handling of fluid and solutes by jackass penguins ...
Calculating Characteristics of the Screws with Constant And Variable Step
Directory of Open Access Journals (Sweden)
B. N. Zotov
2015-01-01
Full Text Available This work is devoted to creating a technique for calculating power characteristics of the screws with constant and variable step for the centrifugal pumps. The technique feature is that the reverse currents, which are observed in screws working at low flow, are numerically taken into account. The paper presents a diagram of the stream in the screw with flow to the network Q=0, and the static pressure of the screw in this mode is computed according to reverse current parameters. Maximum flow of screw is determined from the known formulas. When calculating the power characteristics and computing the overall efficiency of the screw, for the first time a volumetric efficiency of the screw is introduced. It is defined as a ratio between the flow into the network and the sum of the reverse current flows and a flow into the network. This approach allowed us to determine the efficiency of the screw over the entire range of flows.A comparison of experimental characteristics of the constant step screw with those of calculated by the proposed technique shows their good agreement.The technique is also used in calculating characteristics of the variable step screws. The variable step screw is considered as a screw consisting of two screws with a smooth transition of the blades from the inlet to the outlet. Screws in which the step at the inlet is less than that of at the outlet as well as screws with the step at the inlet being more than that of at the outlet were investigated. It is shown that a pressure of the screw with zero step and the value of the reverse currents depend only on the parameters of the input section of the screw, and the maximum flow, if the step at the inlet is more than the step at the outlet, is determined by the parameters of the output part of the screw. Otherwise, the maximum flow is determined a little bit differently.The paper compares experimental characteristics with characteristics calculated by the technique for variable step
Preparation of small group constants for calculation of shielding
International Nuclear Information System (INIS)
Khokhlov, V.F.; Shejno, I.N.; Tkachev, V.D.
1979-01-01
Studied is the effect of the shielding calculation error connected with neglect of the angular and spatial neutron flux dependences while determining the small-group constants on the basis of the many-group ones. The economical method allowing for dependences is proposed. The spatial dependence is substituted by the average value according to the zones singled out in the limits of the zones of the same content; the angular cross section dependence is substituted by the average values in the half-ranges of the angular variable. To solve the transfer equation the ALGOL-ROSA-M program using the method of characteristic interpolation and trial run method is developed. The program regards correctly for nonscattered and single scattered radiations. Compared are the calculation results of neutron transmission (10.5 MeV-0.01 eV) in the 21-group approximation with the 3-group calculations for water (the layer thickness is 30 cm) and 5-group calculations for heterogeneous shielding of alternating stainless steel layers (3 layers, each of the 16 cm thickness) and graphite layers (2 layers, each of the 20 cm thickness). The analysis shows that the method proposed permits to obtain rather accurate results in the course of preparation of the small-group cross sections, decreasing considerably the number of the groups (from 21 to 3-5) and saving the machine time
Calculated Atomic Volumes of the Actinide Metals
DEFF Research Database (Denmark)
Skriver, H.; Andersen, O. K.; Johansson, B.
1979-01-01
The equilibrium atomic volume is calculated for the actinide metals. It is possible to account for the localization of the 5f electrons taking place in americium.......The equilibrium atomic volume is calculated for the actinide metals. It is possible to account for the localization of the 5f electrons taking place in americium....
QED Based Calculation of the Fine Structure Constant
Energy Technology Data Exchange (ETDEWEB)
Lestone, John Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-10-13
Quantum electrodynamics is complex and its associated mathematics can appear overwhelming for those not trained in this field. Here, semi-classical approaches are used to obtain a more intuitive feel for what causes electrostatics, and the anomalous magnetic moment of the electron. These intuitive arguments lead to a possible answer to the question of the nature of charge. Virtual photons, with a reduced wavelength of λ, are assumed to interact with isolated electrons with a cross section of πλ^{2}. This interaction is assumed to generate time-reversed virtual photons that are capable of seeking out and interacting with other electrons. This exchange of virtual photons between particles is assumed to generate and define the strength of electromagnetism. With the inclusion of near-field effects the model presented here gives a fine structure constant of ~1/137 and an anomalous magnetic moment of the electron of ~0.00116. These calculations support the possibility that near-field corrections are the key to understanding the numerical value of the dimensionless fine structure constant.
A library of neutron data for calculating group constants
International Nuclear Information System (INIS)
Koshcheev, V.N.; Nikolaev, M.N.
1987-01-01
This paper describes the first version of a computerized library evaluated neutron data files (FOND) which includes data on the 67 most important nuclear reactor and radiation shielding materials. The data are represented in the ENDF/B format. The sources of data were the results of evaluations of data from differential neutron physics experiments conducted both in the USSR and abroad. The first version of the FOND library is not intended for use in reactor and shielding design calculations, but rather to serve as the basis for developing a corrected version which will guarantee adequate description of the results of a representative set of macroscopic experiments, and for generating multigroup constant systems in methodological research. (author)
Divided Saddle Theory: A New Idea for Rate Constant Calculation.
Daru, János; Stirling, András
2014-03-11
We present a theory of rare events and derive an algorithm to obtain rates from postprocessing the numerical data of a free energy calculation and the corresponding committor analysis. The formalism is based on the division of the saddle region of the free energy profile of the rare event into two adjacent segments called saddle domains. The method is built on sampling the dynamics within these regions: auxiliary rate constants are defined for the saddle domains and the absolute forward and backward rates are obtained by proper reweighting. We call our approach divided saddle theory (DST). An important advantage of our approach is that it requires only standard computational techniques which are available in most molecular dynamics codes. We demonstrate the potential of DST numerically on two examples: rearrangement of alanine-dipeptide (CH3CO-Ala-NHCH3) conformers and the intramolecular Cope reaction of the fluxional barbaralane molecule.
Macroscopic multigroup constants for accelerator driven system core calculation
International Nuclear Information System (INIS)
Heimlich, Adino; Santos, Rubens Souza dos
2011-01-01
The high-level wastes stored in facilities above ground or shallow repositories, in close connection with its nuclear power plant, can take almost 106 years before the radiotoxicity became of the order of the background. While the disposal issue is not urgent from a technical viewpoint, it is recognized that extended storage in the facilities is not acceptable since these ones cannot provide sufficient isolation in the long term and neither is it ethical to leave the waste problem to future generations. A technique to diminish this time is to transmute these long-lived elements into short-lived elements. The approach is to use an Accelerator Driven System (ADS), a sub-critical arrangement which uses a Spallation Neutron Source (SNS), after separation the minor actinides and the long-lived fission products (LLFP), to convert them to short-lived isotopes. As an advanced reactor fuel, still today, there is a few data around these type of core systems. In this paper we generate macroscopic multigroup constants for use in calculations of a typical ADS fuel, take into consideration, the ENDF/BVI data file. Four energy groups are chosen to collapse the data from ENDF/B-VI data file by PREPRO code. A typical MOX fuel cell is used to validate the methodology. The results are used to calculate one typical subcritical ADS core. (author)
Sarangapani, Radhakrishnan; Reddy, Sreekantha T; Sikder, Arun K
2015-04-01
Molecular dynamics simulations studies are carried out on hydroxyl terminated polyethers that are useful in energetic polymeric binder applications. Energetic polymers derived from oxetanes with heterocyclic side chains with different energetic substituents are designed and simulated under the ensembles of constant particle number, pressure, temperature (NPT) and constant particle number, volume, temperature (NVT). Specific volume of different amorphous polymeric models is predicted using NPT-MD simulations as a function of temperature. Plots of specific volume versus temperature exhibited a characteristic change in slope when amorphous systems change from glassy to rubbery state. Several material properties such as Young's, shear, and bulk modulus, Poisson's ratio, etc. are predicted from equilibrated structures and established the structure-property relations among designed polymers. Energetic performance parameters of these polymers are calculated and results reveal that the performance of the designed polymers is comparable to the benchmark energetic polymers like polyNIMMO, polyAMMO and polyBAMO. Overall, it is worthy remark that this molecular simulations study on novel energetic polyethers provides a good guidance on mastering the design principles and allows us to design novel polymers of tailored properties. Copyright © 2015 Elsevier Inc. All rights reserved.
Calculation of hyperfine structure constants of small molecules using ...
Indian Academy of Sciences (India)
SUDIP SASMALa, KAUSHIK TALUKDARb, MALAYA K NAYAKc, NAYANA VAVALa and. SOURAV PALb,∗ ... Abstract. The Z-vector method in the relativistic coupled-cluster framework is employed to calculate the parallel and perpendicular .... subscript c means only the connected terms exist in the contraction between HN ...
EARTHWORK VOLUME CALCULATION FROM DIGITAL TERRAIN MODELS
Directory of Open Access Journals (Sweden)
JANIĆ Milorad
2015-06-01
Full Text Available Accurate calculation of cut and fill volume has an essential importance in many fields. This article shows a new method, which has no approximation, based on Digital Terrain Models. A relatively new mathematical model is developed for that purpose, which is implemented in the software solution. Both of them has been tested and verified in the praxis on several large opencast mines. This application is developed in AutoLISP programming language and works in AutoCAD environment.
Premixed combustion under electric field in a constant volume chamber
Cha, Min Suk
2012-12-01
The effects of electric fields on outwardly propagating premixed flames in a constant volume chamber were experimentally investigated. An electric plug, subjected to high electrical voltages, was used to generate electric fields inside the chamber. To minimize directional ionic wind effects, alternating current with frequency of 1 kHz was employed. Lean and rich fuel/air mixtures for both methane and propane were tested to investigate various preferential diffusion conditions. As a result, electrically induced instability showing cracked structure on the flame surface could be observed. This cracked structure enhanced flame propagation speed for the initial period of combustion and led to reduction in flame initiation and overall combustion duration times. However, by analyzing pressure data, it was found that overall burning rates are not much affected from the electric field for the pressurized combustion period. The reduction of overall combustion time is less sensitive to equivalence ratio for methane/air mixtures, whereas the results demonstrate pronounced effects on a lean mixture for propane. The improvement of combustion characteristics in lean mixtures will be beneficial to the design of lean burn engines. Two hypothetical mechanisms to explain the electrically induced instability were proposed: 1) ionic wind initiated hydrodynamic instability and 2) thermodiffusive instability through the modification of transport property such as mass diffusivity. © 2012 IEEE.
Premixed combustion under electric field in a constant volume chamber
Cha, Min; Lee, Yonggyu
2012-01-01
The effects of electric fields on outwardly propagating premixed flames in a constant volume chamber were experimentally investigated. An electric plug, subjected to high electrical voltages, was used to generate electric fields inside the chamber. To minimize directional ionic wind effects, alternating current with frequency of 1 kHz was employed. Lean and rich fuel/air mixtures for both methane and propane were tested to investigate various preferential diffusion conditions. As a result, electrically induced instability showing cracked structure on the flame surface could be observed. This cracked structure enhanced flame propagation speed for the initial period of combustion and led to reduction in flame initiation and overall combustion duration times. However, by analyzing pressure data, it was found that overall burning rates are not much affected from the electric field for the pressurized combustion period. The reduction of overall combustion time is less sensitive to equivalence ratio for methane/air mixtures, whereas the results demonstrate pronounced effects on a lean mixture for propane. The improvement of combustion characteristics in lean mixtures will be beneficial to the design of lean burn engines. Two hypothetical mechanisms to explain the electrically induced instability were proposed: 1) ionic wind initiated hydrodynamic instability and 2) thermodiffusive instability through the modification of transport property such as mass diffusivity. © 2012 IEEE.
International Nuclear Information System (INIS)
Lapuerta, Magín; Sanz-Argent, Josep; Raine, Robert
2014-01-01
A diagnostic method has been developed to interpret the results of basic combustion studies with diesel-like fuels performed in a constant volume reactor originally conceived for cetane number measurements. The main target of the method is to calculate the instantaneous heat release over time from the chamber pressure experimental signal. The method incorporates filtering of the raw data to eliminate the oscillations recorded as a consequence of the location of the pressure sensor. It considers homogeneity of the gaseous mixture (single zone model) and change in its composition due to the combustion process. A semi-empirical heat transfer model was also proposed and its coefficients were fitted from experimental results obtained in the constant volume chamber using diesel fuel. -- Highlights: • A diagnostic model for constant volume reactors has been developed and tested. • Updating the gas composition after combustion improves accuracy of the method. • Heat transfer coefficients are used for the fulfillment of boundary conditions. • The model provides a deeper insight than the apparent heat release analysis
A calculation of the surface recombination rate constant for hydrogen isotopes on metals
International Nuclear Information System (INIS)
Baskes, M.J.
1980-01-01
The surface recombination rate constant for hydrogen isotopes on a metal has been calculated using a simple model whose parameters may be determined by direct experimental measurements. Using the experimental values for hydrogen diffusivity, solubility, and sticking coefficient at zero surface coverage a reasonable prediction of the surface recombination constant may be made. The calculated recombination constant is in excellent agreement with experiment for bcc iron. A heuristic argument is developed which, along with the rate constant calculation, shows that surface recombination is important in those metals in which hydrogen has an exothermic heat of solution. (orig.)
GRUCAL: a program system for the calculation of macroscopic group constants
International Nuclear Information System (INIS)
Woll, D.
1984-01-01
Nuclear reactor calculations require material- and composition-dependent, energy-averaged neutron physical data in order to decribe the interaction between neutrons and isotopes. The multigroup cross section code GRUCAL calculates these macroscopic group constants for given material compositions from the material-dependent data of the group constant library GRUBA. The instructions for calculating group constants are not fixed in the program, but are read in from an instruction file. This makes it possible to adapt GRUCAL to various problems or different group constant concepts
A Simple and Convenient Method of Multiple Linear Regression to Calculate Iodine Molecular Constants
Cooper, Paul D.
2010-01-01
A new procedure using a student-friendly least-squares multiple linear-regression technique utilizing a function within Microsoft Excel is described that enables students to calculate molecular constants from the vibronic spectrum of iodine. This method is advantageous pedagogically as it calculates molecular constants for ground and excited…
A lattice QCD calculation of the transverse decay constant of the b1(1235) meson
International Nuclear Information System (INIS)
Jansen, K.; McNeile, C.; Michael, C.; Urbach, C.
2009-10-01
We review various B meson decays that require knowledge of the transverse decay constant of the b 1 (1235) meson. We report on an exploratory lattice QCD calculation of the transverse decay constant of the b 1 meson. The lattice QCD calculations used unquenched gauge configurations, at two lattice spacings, generated with two flavours of sea quarks. The twisted mass formalism is used. (orig.)
Calculation of the Green functions by the coupling constant dispersion relations
International Nuclear Information System (INIS)
Bogomalny, E.B.
1977-01-01
The discontinuities of the Green functions on the cut in the complex plane of the coupling constant are calculated by the steepest descent method. The saddle points are given by the solutions of the classical field equations at those values of the coupling constant for which the classical theory has no ground state. The Green functions at the physical values of the coupling constant are determined by dispersion relations. (Auth.)
Vargas, Francisco M.
2014-01-01
The temperature dependence of the Gibbs energy and important quantities such as Henry's law constants, activity coefficients, and chemical equilibrium constants is usually calculated by using the Gibbs-Helmholtz equation. Although, this is a well-known approach and traditionally covered as part of any physical chemistry course, the required…
Algorithm for Calculating the Dissociation Constants of Ampholytes in Nonbuffer Systems
Lysova, S. S.; Skripnikova, T. A.; Zevatskii, Yu. E.
2018-05-01
An algorithm for calculating the dissociation constants of ampholytes in aqueous solutions is developed on the basis of spectrophotometric data in the UV and visible ranges without pH measurements of a medium and without buffer solutions. The proposed algorithm has been experimentally tested for five ampholytes of different strengths. The relative error of measuring dissociation constants is less than 5%.
The correlation schemes in calculations of the rate constants of some radiation chemical reactions
International Nuclear Information System (INIS)
Zagorets, P.A.; Shostenko, A.G.; Kim, V.
1983-01-01
The various correlation relationships of the evaluation of the rate constants of radiation chemical reactions of addition, abstraction and isomerization were considered. It was shown that neglection of the influence of solvent can result in errors in calculations of rate constants equalling two orders in magnitude. Several examples of isokinetic relationship are given. The methods of calculation of transmission coefficient of reaction addition have been discussed. (author)
International Nuclear Information System (INIS)
Milosevic, M.
1979-01-01
One-dimensional variational method for cylindrical configuration was applied for calculating group constants, together with effects of elastic slowing down, anisotropic elastic scattering, inelastic scattering, heterogeneous resonance absorption with the aim to include the presence of a number of different isotopes and effects of neutron leakage from the reactor core. Neutron flux shape P 3 and adjoint function are proposed in order to enable calculation of smaller size reactors and inclusion of heterogeneity effects by cell calculations. Microscopic multigroup constants were prepared based on the UKNDL data library. Analytical-numerical approach was applied for solving the equations of the P 3 approximation to obtain neutron flux moments and adjoint functions
Calculation of elastic constants of BCC transition metals: tight-binding recursion method
International Nuclear Information System (INIS)
Masuda, K.; Hamada, N.; Terakura, K.
1984-01-01
The elastic constants of BCC transition metals (Fe, Nb, Mo and W) are calculated by using the tight-binding d band and the Born-Mayer repulsive potential. Introducing a small distortion characteristic to C 44 (or C') elastic deformation and calculating the energy change up to second order in the atomic displacement, the shear elastic constants C 44 and C' are determined. The elastic constants C 11 and C 12 are then calculated by using the relations B=1/3(C 11 + 2C 12 ) and C'=1/2(C 11 -C 12 ), where B is the bulk modulus. In general, the agreement between the present results and the experimental values is satisfactory. The characteristic elasticity behaviour, i.e. the strong Nsub(d) (number of d electrons) dependence of the observed anisotropy factor A=C 44 /C', will also be discussed. (author)
Calculation of exchange constants in manganese ferrite (MnFe2O4)
International Nuclear Information System (INIS)
Zuo Xu; Barbiellini, Bernardo; Vittoria, Carmine
2004-01-01
The exchange constants and electronic structure of manganese ferrite (MnFe 2 O 4 ) were calculated using Becke's density functional. The total exchange energy consists of Hartree-Fock (HF) and Becke's density functional terms. We introduced one parameter w as the weight of HF's contribution. We also introduced a parameter α to scale the radial part of the 3d wave functions of Fe 3+ ions. By varying w and α the calculated exchange constants were quantitatively fitted to the experimental values of a spinel ferrite for the first time. Direct (d-d) and indirect (d-p-d) hopping are controlled by the parameters w and α
Directory of Open Access Journals (Sweden)
Hamit Yurtseven
2012-01-01
Full Text Available The temperature dependence of the spontaneous polarization P is calculated in the ferroelectric phase of KH2PO4 (KDP at atmospheric pressure (TC = 122 K. Also, the dielectric constant ε is calculated at various temperatures in the paraelectric phase of KDP at atmospheric pressure. For this calculation of P and ε, by fitting the observed Raman frequencies of the soft mode, the microscopic parameters of the pure tunnelling model are obtained. In this model, the proton-lattice interaction is not considered and the collective proton mode is identified with the soft-mode response of the system. Our calculations show that the spontaneous polarization decreases continuously in the ferroelectric phase as approaching the transition temperature TC. Also, the dielectric constant decreases with increasing temperature and it diverges in the vicinity of the transition temperature (TC = 122 K for KDP according to the Curie-Weiss law.
Flow and volume dependence of rat airway resistance during constant flow inflation and deflation.
Rubini, Alessandro; Carniel, Emanuele Luigi; Parmagnani, Andrea; Natali, Arturo Nicola
2011-12-01
The aim of this study was to measure the flow and volume dependence of both the ohmic and the viscoelastic pressure dissipations of the normal rat respiratory system separately during inflation and deflation. The study was conducted in the Respiratory Physiology Laboratory in our institution. Measurements were obtained for Seven albino Wistar rats of both sexes by using the flow interruption method during constant flow inflations and deflations. Measurements included anesthesia induction, tracheostomy and positioning of a tracheal cannula, positive pressure ventilation, constant flow respiratory system inflations and deflations at two different volumes and flows. The ohmic resistance exhibited volume and flow dependence, decreasing with lung volume and increasing with flow rate, during both inflation and deflation. The stress relaxation-related viscoelastic resistance also exhibited volume and flow dependence. It decreased with the flow rate at a constant lung volume during both inflation and deflation, but exhibited a different behavior with the lung volume at a constant flow rate (i.e., increased during inflations and decreased during deflations). Thus, stress relaxation in the rat lungs exhibited a hysteretic behavior. The observed flow and volume dependence of respiratory system resistance may be predicted by an equation derived from a model of the respiratory system that consists of two distinct compartments. The equation agrees well with the experimental data and indicates that the loading time is the critical parameter on which stress relaxation depends, during both lung inflation and deflation.
International Nuclear Information System (INIS)
Liu, D.K.K.; Pyper, J.W.
1977-01-01
Equilibrium constants were calculated for the gas-phase isotopic exchange reactions C 2 H 2 + C 2 D 2 = 2C 2 HD and C 2 H 2 + D 2 O = C 2 D 2 + H 2 O at temperatures ranging from 40 to 2000 0 K. No corrections to the harmonic approximation were made. The results agree quite well with experimental measurements
Relativistic DFT calculations of hyperfine coupling constants in the 5d hexafluorido complexes
DEFF Research Database (Denmark)
Haase, Pi Ariane Bresling; Repisky, Michal; Komorovsky, Stanislav
2018-01-01
We have investigated the performance of the most popular relativistic density functional theory methods, zeroth order regular approximation (ZORA) and 4-component Dirac-Kohn-Sham (DKS), in the calculation of the recently measured hyperfine coupling constants of ReIV and IrIV in their hexafluorido...
Development of Automatic Visceral Fat Volume Calculation Software for CT Volume Data
Directory of Open Access Journals (Sweden)
Mitsutaka Nemoto
2014-01-01
Full Text Available Objective. To develop automatic visceral fat volume calculation software for computed tomography (CT volume data and to evaluate its feasibility. Methods. A total of 24 sets of whole-body CT volume data and anthropometric measurements were obtained, with three sets for each of four BMI categories (under 20, 20 to 25, 25 to 30, and over 30 in both sexes. True visceral fat volumes were defined on the basis of manual segmentation of the whole-body CT volume data by an experienced radiologist. Software to automatically calculate visceral fat volumes was developed using a region segmentation technique based on morphological analysis with CT value threshold. Automatically calculated visceral fat volumes were evaluated in terms of the correlation coefficient with the true volumes and the error relative to the true volume. Results. Automatic visceral fat volume calculation results of all 24 data sets were obtained successfully and the average calculation time was 252.7 seconds/case. The correlation coefficients between the true visceral fat volume and the automatically calculated visceral fat volume were over 0.999. Conclusions. The newly developed software is feasible for calculating visceral fat volumes in a reasonable time and was proved to have high accuracy.
MCFT: a program for calculating fast and thermal neutron multigroup constants
International Nuclear Information System (INIS)
Yang Shunhai; Sang Xinzeng
1993-01-01
MCFT is a program for calculating the fast and thermal neutron multigroup constants, which is redesigned from some codes for generation of thermal neutron multigroup constants and for fast neutron multigroup constants adapted on CYBER 825 computer. It uses indifferently as basic input with the evaluated nuclear data contained in the ENDF/B (US), KEDAK (Germany) and UK (United Kingdom) libraries. The code includes a section devoted to the generation of resonant Doppler broadened cross section in the framework of single-or multi-level Breit-Wigner formalism. The program can compute the thermal neutron scattering law S (α, β, T) as the input data in tabular, free gas or diffusion motion form. It can treat up to 200 energy groups and Legendre moments up to P 5 . The output consists of various reaction multigroup constants in all neutron energy range desired in the nuclear reactor design and calculation. Three options in input file can be used by the user. The output format is arbitrary and defined by user with a minimum of program modification. The program includes about 15,000 cards and 184 subroutines. FORTRAN 5 computer language is used. The operation system is under NOS 2 on computer CYBER 825
Calculation of nuclear spin-spin coupling constants using frozen density embedding
Energy Technology Data Exchange (ETDEWEB)
Götz, Andreas W., E-mail: agoetz@sdsc.edu [San Diego Supercomputer Center, University of California San Diego, 9500 Gilman Dr MC 0505, La Jolla, California 92093-0505 (United States); Autschbach, Jochen [Department of Chemistry, University at Buffalo, State University of New York, Buffalo, New York 14260-3000 (United States); Visscher, Lucas, E-mail: visscher@chem.vu.nl [Amsterdam Center for Multiscale Modeling (ACMM), VU University Amsterdam, Theoretical Chemistry, De Boelelaan 1083, 1081 HV Amsterdam (Netherlands)
2014-03-14
We present a method for a subsystem-based calculation of indirect nuclear spin-spin coupling tensors within the framework of current-spin-density-functional theory. Our approach is based on the frozen-density embedding scheme within density-functional theory and extends a previously reported subsystem-based approach for the calculation of nuclear magnetic resonance shielding tensors to magnetic fields which couple not only to orbital but also spin degrees of freedom. This leads to a formulation in which the electron density, the induced paramagnetic current, and the induced spin-magnetization density are calculated separately for the individual subsystems. This is particularly useful for the inclusion of environmental effects in the calculation of nuclear spin-spin coupling constants. Neglecting the induced paramagnetic current and spin-magnetization density in the environment due to the magnetic moments of the coupled nuclei leads to a very efficient method in which the computationally expensive response calculation has to be performed only for the subsystem of interest. We show that this approach leads to very good results for the calculation of solvent-induced shifts of nuclear spin-spin coupling constants in hydrogen-bonded systems. Also for systems with stronger interactions, frozen-density embedding performs remarkably well, given the approximate nature of currently available functionals for the non-additive kinetic energy. As an example we show results for methylmercury halides which exhibit an exceptionally large shift of the one-bond coupling constants between {sup 199}Hg and {sup 13}C upon coordination of dimethylsulfoxide solvent molecules.
International Nuclear Information System (INIS)
Santos, Rubens Souza dos; Martinez, Aquilino Senra; Alvim, Antonio Carlos Marques
2002-01-01
In this work is presented a methodology which focuses the distribution of neutron absorber rods in nuclear reactor power plants, for utilizing in space kinetic calculations, principally in the cluster ejection transients of control rods. A numerical model for macroscopic constant calculations based on the knowledge of the neutron flux without the control rods is proposed, as alternative to the analytical models, based on the hypothesis of the null current on the cell super boundaries. The proposed model in this work has itself showed adequate to deal with problems with strong space dependence, once that the model showed consistence in the global average built in the analytical model. (author)
Minkov, Ivan L.; Manev, Emil D.; Sazdanova, Svetla V.; Kolikov, Kiril H.
2013-01-01
Osmosis is essential for the living organisms. In biological systems the process usually occurs in confined volumes and may express specific features. The osmotic pressure in aqueous solutions was studied here experimentally as a function of solute concentration (0.05–0.5 M) in two different regimes: of constant and variable solution volume. Sucrose, a biologically active substance, was chosen as a reference solute for the complex tests. A custom made osmotic cell was used. A novel operative experimental approach, employing limited variation of the solution volume, was developed and applied for the purpose. The established equilibrium values of the osmotic pressure are in agreement with the theoretical expectations and do not exhibit any evident differences for both regimes. In contrast, the obtained kinetic dependences reveal striking divergence in the rates of the process at constant and varied solution volume for the respective solute concentrations. The rise of pressure is much faster at constant solution volume, while the solvent influx is many times greater in the regime of variable volume. The results obtained suggest a feasible mechanism for the way in which the living cells rapidly achieve osmotic equilibrium upon changes in the environment. PMID:24459448
Thermosetting resins with high fractions of free volume and inherently low dielectric constants.
Lin, Liang-Kai; Hu, Chien-Chieh; Su, Wen-Chiung; Liu, Ying-Ling
2015-08-18
This work demonstrates a new class of thermosetting resins, based on Meldrum's acid (MA) derivatives, which have high fractions of free volume and inherently low k values of about 2.0 at 1 MHz. Thermal decomposition of the MA groups evolves CO2 and acetone to create air-trapped cavities so as to reduce the dielectric constants.
Does the Addition of Inert Gases at Constant Volume and Temperature Affect Chemical Equilibrium?
Paiva, Joao C. M.; Goncalves, Jorge; Fonseca, Susana
2008-01-01
In this article we examine three approaches, leading to different conclusions, for answering the question "Does the addition of inert gases at constant volume and temperature modify the state of equilibrium?" In the first approach, the answer is yes as a result of a common students' alternative conception; the second approach, valid only for ideal…
Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber
Jing, Wei; Roberts, William L.; Fang, Tiegang
2015-01-01
This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2
High speed analysis of high pressure combustion in a constant volume cell
Frijters, P.J.M.; Klein-Douwel, R.J.H.; Manski, S.S.; Somers, L.M.T.; Baert, R.S.G.; Dias, V.
2005-01-01
A combustion process with N2, O2 and C2H4 as fuel used in an opticallyaccessible, high pressure, high temperature, constant volume cell forresearch on diesel fuel spray formation, is studied. The flame frontspeed Vf,HS is determined using high speed imaging. The pressure traceof the combustion
Piezoelectric constants for ZnO calculated using classical polarizable core-shell potentials
International Nuclear Information System (INIS)
Dai Shuangxing; Dunn, Martin L; Park, Harold S
2010-01-01
We demonstrate the feasibility of using classical atomistic simulations, i.e. molecular dynamics and molecular statics, to study the piezoelectric properties of ZnO using core-shell interatomic potentials. We accomplish this by reporting the piezoelectric constants for ZnO as calculated using two different classical interatomic core-shell potentials: that originally proposed by Binks and Grimes (1994 Solid State Commun. 89 921-4), and that proposed by Nyberg et al (1996 J. Phys. Chem. 100 9054-63). We demonstrate that the classical core-shell potentials are able to qualitatively reproduce the piezoelectric constants as compared to benchmark ab initio calculations. We further demonstrate that while the presence of the shell is required to capture the electron polarization effects that control the clamped ion part of the piezoelectric constant, the major shortcoming of the classical potentials is a significant underprediction of the clamped ion term as compared to previous ab initio results. However, the present results suggest that overall, these classical core-shell potentials are sufficiently accurate to be utilized for large scale atomistic simulations of the piezoelectric response of ZnO nanostructures.
Hahn, Steven; Arapan, Sergiu; Harmon, Bruce; Eriksson, Olle
2011-03-01
Conventional first principle methods for calculating lattice dynamics are unable to calculate high temperature thermophysical properties of materials containing modes that are entropically stabilized. In this presentation we use a relatively new approach called self-consistent ab initio lattice dynamics (SCAILD) to study the hcp to bcc transition (1530 K) in beryllium. The SCAILD method goes beyond the harmonic approximation to include phonon-phonon interactions and produces a temperature-dependent phonon dispersion. In the high temperature bcc structure, phonon-phonon interactions dynamically stabilize the N-point phonon. Fits to the calculated phonon dispersion were used to determine the temperature dependence of the elastic constants in the hcp and bcc phases. Work at the Ames Laboratory was supported by the Department of Energy-Basic Energy Sciences under Contract No. DE-AC02-07CH11358.
Mols, G; Kessler, V; Benzing, A; Lichtwarck-Aschoff, M; Geiger, K; Guttmann, J
2001-02-01
When managing patients with acute respiratory distress syndrome (ARDS), respiratory system compliance is usually considered first and changes in resistance, although recognized, are neglected. Resistance can change considerably between minimum and maximum lung volume, but is generally assumed to be constant in the tidal volume range (V(T)). We measured resistance during tidal ventilation in 16 patients with ARDS or acute lung injury by the slice method and multiple linear regression analysis. Resistance was constant within V(T) in only six of 16 patients. In the remaining patients, resistance decreased, increased or showed complex changes. We conclude that resistance within V(T) varies considerably from patient to patient and that constant resistance within V(T) is not always likely.
Energy Technology Data Exchange (ETDEWEB)
Elsharkawy, A.M.; Foda, S.G. [Kuwait University, Safat (Kuwait). Petroleum Engineering Dept.
1998-03-01
Currently, two approaches are being used to predict the changes in retrograde gas condensate composition and estimate the pressure depletion behavior of gas condensate reservoirs. The first approach uses the equation of states whereas the second uses empirical correlations. Equations of states (EOS) are poor predictive tools for complex hydrocarbon systems. The EOS needs adjustment against phase behavior data of reservoir fluid of known composition. The empirical correlation does not involve numerous numerical computations but their accuracy is limited. This study presents two general regression neural network (GRNN) models. The first model, GRNNM1, is developed to predict dew point pressure and gas compressibility at dew point using initial composition of numerous samples while the second model, GRNNM2, is developed to predict the changes in well stream effluent composition at any stages of pressure depletion. GRNNM2 can also be used to determine the initial reservoir fluid composition using dew point pressure, gas compressibility at dew point, and reservoir temperature. These models are based on analysis of 142 sample of laboratory studies of constant volume depletion (CVD) for gas condensate systems forming a total of 1082 depletion stages. The database represents a wide range of gas condensate systems obtained worldwide. The performance of the GRNN models has been compared to simulation results of the equation of state. The study shows that the proposed general regression neural network models are accurate, valid, and reliable. These models can be used to forecast CVD data needed for many reservoir engineering calculations in case laboratory data is unavailable. The GRNN models save computer time involved in EOS calculations. The study also show that once these models are properly trained they can be used to cut expenses of frequent sampling and laborious experimental CVD tests required for gas condensate reservoirs. 55 refs., 13 figs., 6 tabs.
Continuous energy Monte Carlo method based homogenization multi-group constants calculation
International Nuclear Information System (INIS)
Li Mancang; Wang Kan; Yao Dong
2012-01-01
The efficiency of the standard two-step reactor physics calculation relies on the accuracy of multi-group constants from the assembly-level homogenization process. In contrast to the traditional deterministic methods, generating the homogenization cross sections via Monte Carlo method overcomes the difficulties in geometry and treats energy in continuum, thus provides more accuracy parameters. Besides, the same code and data bank can be used for a wide range of applications, resulting in the versatility using Monte Carlo codes for homogenization. As the first stage to realize Monte Carlo based lattice homogenization, the track length scheme is used as the foundation of cross section generation, which is straight forward. The scattering matrix and Legendre components, however, require special techniques. The Scattering Event method was proposed to solve the problem. There are no continuous energy counterparts in the Monte Carlo calculation for neutron diffusion coefficients. P 1 cross sections were used to calculate the diffusion coefficients for diffusion reactor simulator codes. B N theory is applied to take the leakage effect into account when the infinite lattice of identical symmetric motives is assumed. The MCMC code was developed and the code was applied in four assembly configurations to assess the accuracy and the applicability. At core-level, A PWR prototype core is examined. The results show that the Monte Carlo based multi-group constants behave well in average. The method could be applied to complicated configuration nuclear reactor core to gain higher accuracy. (authors)
ChPT loops for the lattice: pion mass and decay constant, HVP at finite volume and nn̅-oscillations
Directory of Open Access Journals (Sweden)
Bijnens Johan
2018-01-01
Full Text Available I present higher loop order results for several calculations in Chiral perturbation Theory. 1 Two-loop results at finite volume for hadronic vacuum polarization. 2 A three-loop calculation of the pion mass and decay constant in two-flavour ChPT. For the pion mass all needed auxiliary parameters can be determined from lattice calculations of ππ-scattering. 3 Chiral corrections to neutron-anti-neutron oscillations.
ChPT loops for the lattice: pion mass and decay constant, HVP at finite volume and nn̅-oscillations
Bijnens, Johan
2018-03-01
I present higher loop order results for several calculations in Chiral perturbation Theory. 1) Two-loop results at finite volume for hadronic vacuum polarization. 2) A three-loop calculation of the pion mass and decay constant in two-flavour ChPT. For the pion mass all needed auxiliary parameters can be determined from lattice calculations of ππ-scattering. 3) Chiral corrections to neutron-anti-neutron oscillations.
A modified CAS-CI approach for an efficient calculation of magnetic exchange coupling constants
Fink, Karin; Staemmler, Volker
2013-09-01
A modification of the conventional wavefunction-based CAS-CI method for the calculation of magnetic exchange coupling constants J in small molecules and transition metal complexes is presented. In general, CAS-CI approaches yield much too small values for J since the energies of the important charge transfer configurations are calculated with the ground state orbitals and are therefore much too high. In the present approach we improve these energies by accounting for the relaxation of the orbitals in the charge transfer configurations. The necessary relaxation energies R can be obtained in separate calculations using mononuclear or binuclear model systems. The method is applied to a few examples, small molecules, binuclear transition metal complexes, and bulk NiO. It allows to obtaining fairly reliable estimates for J at costs that are not higher than those of conventional CAS-CI calculations. Therefore, extended and very time-consuming perturbation theory (PT2), configuration interaction (CI), or coupled cluster (CC) schemes on top of the CAS-CI calculation can be avoided and the modified CAS-CI (MCAS-CI) approach can be applied to rather large systems.
A program for calculating group constants on the basis of libraries of evaluated neutron data
International Nuclear Information System (INIS)
Sinitsa, V.V.
1987-01-01
The GRUKON program is designed for processing libraries of evaluated neutron data into group and fine-group (having some 300 groups) microscopic constants. In structure it is a package of applications programs with three basic components: a monitor, a command language and a library of functional modules. The first operative version of the package was restricted to obtaining mid-group non-block cross-sections from evaluated neutron data libraries in the ENDF/B format. This was then used to process other libraries. In the next two versions, cross-section table conversion modules and self-shielding factor calculation modules, respectively, were added to the functions already in the package. Currently, a fourth version of the GRUKON applications program package, for calculation of sub-group parameters, is under preparation. (author)
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
International Nuclear Information System (INIS)
Cacuci, D.G.
1978-01-01
Some aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. In deriving these formulas, use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were greatly aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation, via FORMAC, of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u -5 . The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, is one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M 2 (u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
International Nuclear Information System (INIS)
Cacuci, D.G.
1978-04-01
Aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann Equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. Use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u -5 . The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, represent one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M 2 (u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
Energy Technology Data Exchange (ETDEWEB)
Cacuci, D.G.
1978-04-01
Aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann Equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. Use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u/sup -5/. The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, represent one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M/sub 2/(u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table.
International Nuclear Information System (INIS)
Kim, Yong Seong; Jang, Yun Hee; Cho, Hyun; Hwang, Sun Gu
2010-01-01
The relative stabilities of the tautomers of SeG were calculated. In the aqueous phase, amino-seleno form was the major tautomer of neutral SeG with a minor contribution from the other amino-seleno form. The presence of the selenolic form was negligible from the calculations. The microscopic and macroscopic pKa values in the aqueous phase were calculated from this scheme. The calculated pKa value was in good agreement with the experimental data. These results demonstrated that this method could predict and explain the acid-base properties of SeG and could be used to understand the behavior of the species. A number of analogues of nucleic acid bases have been the target of extensive studies because of their importance in many biological studies. The oxygen of both purine and pyrimidine bases is substituted with sulfur or selenium to produce an important class of analogues. 6-Selenoguanine (SeG) has a significant activity against L5178Y lymphoma cells. However, the detailed mechanism of the antiplastic action is not known yet. Information on the acid dissociation constants and the tautomerism of the molecules is required to provide a molecular level understanding of biological processes. Proton-transfer in the nucleic acid pairs and the presence of the tautomeric equilibrium play an important role in the mispair formation during the DNA replication
Energy Technology Data Exchange (ETDEWEB)
Millman, D. L. [Dept. of Computer Science, Univ. of North Carolina at Chapel Hill (United States); Griesheimer, D. P.; Nease, B. R. [Bechtel Marine Propulsion Corporation, Bertis Atomic Power Laboratory (United States); Snoeyink, J. [Dept. of Computer Science, Univ. of North Carolina at Chapel Hill (United States)
2012-07-01
In this paper we consider a new generalized algorithm for the efficient calculation of component object volumes given their equivalent constructive solid geometry (CSG) definition. The new method relies on domain decomposition to recursively subdivide the original component into smaller pieces with volumes that can be computed analytically or stochastically, if needed. Unlike simpler brute-force approaches, the proposed decomposition scheme is guaranteed to be robust and accurate to within a user-defined tolerance. The new algorithm is also fully general and can handle any valid CSG component definition, without the need for additional input from the user. The new technique has been specifically optimized to calculate volumes of component definitions commonly found in models used for Monte Carlo particle transport simulations for criticality safety and reactor analysis applications. However, the algorithm can be easily extended to any application which uses CSG representations for component objects. The paper provides a complete description of the novel volume calculation algorithm, along with a discussion of the conjectured error bounds on volumes calculated within the method. In addition, numerical results comparing the new algorithm with a standard stochastic volume calculation algorithm are presented for a series of problems spanning a range of representative component sizes and complexities. (authors)
International Nuclear Information System (INIS)
Millman, D. L.; Griesheimer, D. P.; Nease, B. R.; Snoeyink, J.
2012-01-01
In this paper we consider a new generalized algorithm for the efficient calculation of component object volumes given their equivalent constructive solid geometry (CSG) definition. The new method relies on domain decomposition to recursively subdivide the original component into smaller pieces with volumes that can be computed analytically or stochastically, if needed. Unlike simpler brute-force approaches, the proposed decomposition scheme is guaranteed to be robust and accurate to within a user-defined tolerance. The new algorithm is also fully general and can handle any valid CSG component definition, without the need for additional input from the user. The new technique has been specifically optimized to calculate volumes of component definitions commonly found in models used for Monte Carlo particle transport simulations for criticality safety and reactor analysis applications. However, the algorithm can be easily extended to any application which uses CSG representations for component objects. The paper provides a complete description of the novel volume calculation algorithm, along with a discussion of the conjectured error bounds on volumes calculated within the method. In addition, numerical results comparing the new algorithm with a standard stochastic volume calculation algorithm are presented for a series of problems spanning a range of representative component sizes and complexities. (authors)
A low-temperature (4-300K) constant volume gas thermometer
International Nuclear Information System (INIS)
Combarieu, A. de
1976-01-01
A constant volume gas thermometer was built to calibrate the various secondary thermometers used at low temperature. This gas thermometer is placed in a cryostat where any stable temperature between 4 and 300K may be obtained. The principle is outlined, then the gas thermometer and its auxiliary equipment are briefly described; the corrections to be applied to the results are given and a table shows the values obtained [fr
Wu, Zengyang
2016-08-18
In this paper, spray combustion of diesel (No. 2) and diesel-gasoline blend (dieseline: 80% diesel and 20% gasoline by volume) were investigated in an optically accessible constant volume combustion chamber. Effects of ambient conditions on flame emissions were studied. Ambient oxygen concentration was varied from 12% to 21% and three ambient temperatures were selected: 800 K, 1000 K and 1200 K. An intensified CCD camera coupled with bandpass filters was employed to capture the quasi-steady state flame emissions at 430 nm and 470 nm bands. Under non-sooting conditions, the narrow-band flame emissions at 430 nm and 470 nm can be used as indicators of CH∗ (methylidyne) and HCHO∗ (formaldehyde), respectively. The lift-off length was measured by imaging the OH∗ chemiluminescence at 310 nm. Flame emission structure and intensity distribution were compared between dieseline and diesel at wavelength bands. Flame emission images show that both narrow band emissions become shorter, thinner and stronger with higher oxygen concentration and higher ambient temperature for both fuels. Areas of weak intensity are observed at the flame periphery and the upstream for both fuels under all ambient conditions. Average flame emission intensity and area were calculated for 430 nm and 470 nm narrow-band emissions. At a lower ambient temperature the average intensity increases with increasing ambient oxygen concentration. However, at the 1200 K ambient temperature condition, the average intensity is not increasing monotonically for both fuels. For most of the conditions, diesel has a stronger average flame emission intensity than dieseline for the 430 nm band, and similar phenomena can be observed for the 470 nm band with 800 K and 1200 K ambient temperatures. However, for the 1000 K ambient temperature cases, dieseline has stronger average flame emission intensities than diesel for all oxygen concentrations at 470 nm band. Flame emissions for the two bands have a
Volume calculation from limited number of MR imaging sections
International Nuclear Information System (INIS)
Wang, J.; Mezrich, R.; Sebok, D.
1988-01-01
Magnetic resonance imaging is an accurate and noninvasive way to obtain cardiac geometrical information. For the quantification of left ventricular dynamic parameters, sections are taken along the long axis of the ventricle. Due to the limited number of sections that can be obtained in a reasonable amount of scanning time, the estimation of longitudinal dimension is usually the cause of error in volume calculation. The starting and ending sections are best estimated by guidance of the short axis cuts. This can only guarantee first-order accuracy. Simpson's rule for summation of areas to calculate volume, which is the commonly used method, assumes an accurate knowledge of the starting and ending points of integration. When this assumption is not perfectly met, Simpson's rule tends to unsystemically over- or underestimate the true volume. Due to this concern, some researchers adopt the images from the short axis cut to aid the volume calculation. This can improve the accuracy, but makes the already long scanning time longer. The authors have derived a method of extrapolation and intrapolation based on no more information than usually available to correct the volume over- or underestimated by the Simpson's rule
Irwanto, Dwi; Setiadipura, Topan; Pramutadi, Asril
2017-07-01
There are two type of High Temperature Gas Reactor (HTGR), prismatic and pebble bed. Pebble Bed type has unique configuration because the fuels are randomly distributed inside the reactor core. In term of safety features, Pebble Bed Reactor (PBR) is one of the most promising reactor type in avoiding severe nuclear accidents. In order to analyze heat transfer and safety of this reactor type, a computer code is now under development. As a first step, calculation method proposed by Stroh [1] is adopted. An approach has been made to treat randomly distributed pebble balls contains fissile material inside the reactor core as a porous medium. Helium gas act as coolant on the reactor system are carrying heat flowing in the area between the pebble balls. Several parameters and constants are taken into account in the new developed code. Progress of the development of the code especially comparison of several thermal conductivity constants for a certain PBR-case are reported in the present study.
A lattice calculation of the decay constants of heavy-light pseudoscalars
International Nuclear Information System (INIS)
Labrenz, J.N.
1992-08-01
A lattice calculation of the decay constants for D and B mesons is described. Results are obtained (in the quenched approximation) from wall-source lattices in Coulomb gauge at β = 6.3, through a procedure that interpolates smoothly between the static approximation of Eichten and the conventional (''heavy'' Wilson fermion) method. The previously observed discrepancy between these two approaches has been understood, and we discuss the resolution and its limitations. We find f D = 206(9) ± 37 MeV, f D s = 231(7) ± 39 MeV, f B = 179(10) ± 39 MeV, and f B s = 203(8) ± 42 MeV. The first error in each result is statistical, resulting from the jackknife procedure applied to the full analysis. The second is our estimate of systematic errors due to scale-breaking, axial current renormalization, and fitting or extrapolation uncertainties
Programmable calculator programs to solve softwood volume and value equations.
Janet K. Ayer. Sachet
1982-01-01
This paper presents product value and product volume equations as programs for handheld calculators. These tree equations are for inland Douglas-fir, young-growth Douglas-fir, western white pine, ponderosa pine, and western larch. Operating instructions and an example are included.
Quantum chemical and conventional TST calculations of rate constants for the OH + alkane reaction
International Nuclear Information System (INIS)
Bravo-Perez, Graciela; Alvarez-Idaboy, J. Raul; Jimenez, Annia Galano; Cruz-Torres, Armando
2005-01-01
Reactions of OH with methane, ethane, propane, i-butane, and n-butane have been modeled using ab initio (MP2) and hybrid DFT (BHandHLYP) methods, and the 6-311G(d,p) basis set. Furthermore, single-point calculations at the CCSD(T) level were carried out at the optimized geometries. The rate constants have been calculated using the conventional transition-state theory (CTST). Arrhenius equations are proposed in the temperature range of 250-650 K. Hindered Internal Rotation partition functions calculations were explicitly carried out and included in the total partition functions. These corrections showed to be relevant in the determination of the pre-exponential parameters, although not so important as in the NO 3 + alkane reactions [G. Bravo-Perez, J.R. Alvarez-Idaboy, A. Cruz-Torres, M.E. Ruiz, J. Phys. Chem. A 106 (2002) 4645]. The explicit participation of the tunnel effect has been taken into account. The calculated rate coefficients provide a very good agreement with the experimental data. The best agreement for the overall alkane + OH reactions seemed to occur when the BHandHLYP geometries and partition functions are used. For propane and i-butane, in addition to the respective secondary and tertiary H-abstraction channels, the primary one has been considered. These pathways are confirmed to be significant in spite of the large differences in activation energies between primary and secondary or primary and tertiary channels, respectively of propane and i-butane reactions and should not be disregarded
A lattice QCD calculation of the transverse decay constant of the b{sub 1}(1235) meson
Energy Technology Data Exchange (ETDEWEB)
Jansen, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; McNeile, C. [Wuppertal Univ. (Germany). Theoretische Teilchenphysik; Michael, C. [Liverpool Univ. (United Kingdom). Theoretical Physics Division, Dept. of Mathematical Sciences; Urbach, C. [Humboldt-Univ., Berlin (Germany). Theorie der Elementarteilchen
2009-10-15
We review various B meson decays that require knowledge of the transverse decay constant of the b{sub 1}(1235) meson. We report on an exploratory lattice QCD calculation of the transverse decay constant of the b{sub 1} meson. The lattice QCD calculations used unquenched gauge configurations, at two lattice spacings, generated with two flavours of sea quarks. The twisted mass formalism is used. (orig.)
International Nuclear Information System (INIS)
Reshak, Ali H.; Jamal, Morteza
2012-01-01
Highlights: ► A new package for calculating elastic constants of orthorhombic structure is released. ► The package called ortho-elastic. ► It is compatible with [FP-(L)APW+lo] method implemented in WIEN2k code. ► Several orthorhombic structure compounds were used to test the new package. ► Elastic constants calculated using this package show good agreement with experiment. - Abstract: A new package for calculating the elastic constants of orthorhombic structure is released. The package called ortho-elastic. The formalism of calculating the ortho-elastic constants is described in details. The package is compatible with the highly accurate all-electron full-potential (linearized) augmented plane-wave plus local orbital [FP-(L)APW+lo] method implemented in WIEN2k code. Several orthorhombic structure compounds were used to test the new package. We found that the calculated elastic constants using the new package show better agreement with the available experimental data than the previous theoretical results used different methods. In this package the second-order derivative E ″ (ε) of polynomial fit E=E(ε) of energy vs strains at zero strain (ε=0), used to calculate the orthorhombic elastic constants.
105-KW Sandfilter Backwash Pit sludge volume calculation
International Nuclear Information System (INIS)
Dodd, E.N. Jr.
1995-01-01
The volume of sludge contained in the 100-KW Sandfilter Backwash Pit (SFBWP) was calculated from depth measurements of the sludge, pit dimension measurements and analysis of video tape recordings taken by an underwater camera. The term sludge as used in this report is any combination of sand, sediment, or corrosion products visible in the SFBWP area. This work was performed to determine baseline volume for use in determination of quantities of uranium and plutonium deposited in the pit from sandfilter backwashes. The SFBWP has three areas where sludge is deposited: (1) the main pit floor, (2) the transfer channel floor, and (3) the surfaces and structures in the SFBWP. The depths of sludge and the uniformity of deposition varies significantly between these three areas. As a result, each of the areas was evaluated separately. The total volume of sludge determined was 3.75 M 3 (132.2 ft 3 )
DEFF Research Database (Denmark)
Steinmann, Casper; Olsen, Jógvan Magnus Haugaard; Kongsted, Jacob
2014-01-01
We present NMR shielding constants obtained through quantum mechanical/molecular mechanical (QM/MM) embedding calculations. Contrary to previous reports, we show that a relatively small QM region is sufficient, provided that a high-quality embedding potential is used. The calculated averaged NMR...... shielding constants of both acrolein and acetone solvated in water are based on a number of snapshots extracted from classical molecular dynamics simulations. We focus on the carbonyl chromophore in both molecules, which shows large solvation effects, and we study the convergence of shielding constants...
Efficient calculation of nuclear spin-rotation constants from auxiliary density functional theory
Energy Technology Data Exchange (ETDEWEB)
Zuniga-Gutierrez, Bernardo, E-mail: bzuniga.51@gmail.com [Departamento de Ciencias Computacionales, Universidad de Guadalajara, Blvd. Marcelino García Barragán 1421, C.P. 44430 Guadalajara, Jalisco (Mexico); Camacho-Gonzalez, Monica [Universidad Tecnológica de Tecámac, División A2, Procesos Industriales, Carretera Federal México Pachuca Km 37.5, Col. Sierra Hermosa, C.P. 55740 Tecámac, Estado de México (Mexico); Bendana-Castillo, Alfonso [Universidad Tecnológica de Tecámac, División A3, Tecnologías de la Información y Comunicaciones, Carretera Federal México Pachuca Km 37.5, Col. Sierra Hermosa, C.P. 55740 Tecámac, Estado de México (Mexico); Simon-Bastida, Patricia [Universidad Tecnlógica de Tulancingo, División Electromecánica, Camino a Ahuehuetitla No. 301, Col. Las Presas, C.P. 43642 Tulancingo, Hidalgo (Mexico); Calaminici, Patrizia; Köster, Andreas M. [Departamento de Química, CINVESTAV, Avenida Instituto Politécnico Nacional 2508, A.P. 14-740, México D.F. 07000 (Mexico)
2015-09-14
The computation of the spin-rotation tensor within the framework of auxiliary density functional theory (ADFT) in combination with the gauge including atomic orbital (GIAO) scheme, to treat the gauge origin problem, is presented. For the spin-rotation tensor, the calculation of the magnetic shielding tensor represents the most demanding computational task. Employing the ADFT-GIAO methodology, the central processing unit time for the magnetic shielding tensor calculation can be dramatically reduced. In this work, the quality of spin-rotation constants obtained with the ADFT-GIAO methodology is compared with available experimental data as well as with other theoretical results at the Hartree-Fock and coupled-cluster level of theory. It is found that the agreement between the ADFT-GIAO results and the experiment is good and very similar to the ones obtained by the coupled-cluster single-doubles-perturbative triples-GIAO methodology. With the improved computational performance achieved, the computation of the spin-rotation tensors of large systems or along Born-Oppenheimer molecular dynamics trajectories becomes feasible in reasonable times. Three models of carbon fullerenes containing hundreds of atoms and thousands of basis functions are used for benchmarking the performance. Furthermore, a theoretical study of temperature effects on the structure and spin-rotation tensor of the H{sup 12}C–{sup 12}CH–DF complex is presented. Here, the temperature dependency of the spin-rotation tensor of the fluorine nucleus can be used to identify experimentally the so far unknown bent isomer of this complex. To the best of our knowledge this is the first time that temperature effects on the spin-rotation tensor are investigated.
Efficient calculation of nuclear spin-rotation constants from auxiliary density functional theory
International Nuclear Information System (INIS)
Zuniga-Gutierrez, Bernardo; Camacho-Gonzalez, Monica; Bendana-Castillo, Alfonso; Simon-Bastida, Patricia; Calaminici, Patrizia; Köster, Andreas M.
2015-01-01
The computation of the spin-rotation tensor within the framework of auxiliary density functional theory (ADFT) in combination with the gauge including atomic orbital (GIAO) scheme, to treat the gauge origin problem, is presented. For the spin-rotation tensor, the calculation of the magnetic shielding tensor represents the most demanding computational task. Employing the ADFT-GIAO methodology, the central processing unit time for the magnetic shielding tensor calculation can be dramatically reduced. In this work, the quality of spin-rotation constants obtained with the ADFT-GIAO methodology is compared with available experimental data as well as with other theoretical results at the Hartree-Fock and coupled-cluster level of theory. It is found that the agreement between the ADFT-GIAO results and the experiment is good and very similar to the ones obtained by the coupled-cluster single-doubles-perturbative triples-GIAO methodology. With the improved computational performance achieved, the computation of the spin-rotation tensors of large systems or along Born-Oppenheimer molecular dynamics trajectories becomes feasible in reasonable times. Three models of carbon fullerenes containing hundreds of atoms and thousands of basis functions are used for benchmarking the performance. Furthermore, a theoretical study of temperature effects on the structure and spin-rotation tensor of the H 12 C– 12 CH–DF complex is presented. Here, the temperature dependency of the spin-rotation tensor of the fluorine nucleus can be used to identify experimentally the so far unknown bent isomer of this complex. To the best of our knowledge this is the first time that temperature effects on the spin-rotation tensor are investigated
Efficient calculation of nuclear spin-rotation constants from auxiliary density functional theory.
Zuniga-Gutierrez, Bernardo; Camacho-Gonzalez, Monica; Bendana-Castillo, Alfonso; Simon-Bastida, Patricia; Calaminici, Patrizia; Köster, Andreas M
2015-09-14
The computation of the spin-rotation tensor within the framework of auxiliary density functional theory (ADFT) in combination with the gauge including atomic orbital (GIAO) scheme, to treat the gauge origin problem, is presented. For the spin-rotation tensor, the calculation of the magnetic shielding tensor represents the most demanding computational task. Employing the ADFT-GIAO methodology, the central processing unit time for the magnetic shielding tensor calculation can be dramatically reduced. In this work, the quality of spin-rotation constants obtained with the ADFT-GIAO methodology is compared with available experimental data as well as with other theoretical results at the Hartree-Fock and coupled-cluster level of theory. It is found that the agreement between the ADFT-GIAO results and the experiment is good and very similar to the ones obtained by the coupled-cluster single-doubles-perturbative triples-GIAO methodology. With the improved computational performance achieved, the computation of the spin-rotation tensors of large systems or along Born-Oppenheimer molecular dynamics trajectories becomes feasible in reasonable times. Three models of carbon fullerenes containing hundreds of atoms and thousands of basis functions are used for benchmarking the performance. Furthermore, a theoretical study of temperature effects on the structure and spin-rotation tensor of the H(12)C-(12)CH-DF complex is presented. Here, the temperature dependency of the spin-rotation tensor of the fluorine nucleus can be used to identify experimentally the so far unknown bent isomer of this complex. To the best of our knowledge this is the first time that temperature effects on the spin-rotation tensor are investigated.
International Nuclear Information System (INIS)
Guerrero, Thomas; Castillo, Richard; Sanders, Kevin; Price, Roger; Komaki, Ritsuko; Cody, Dianna
2006-01-01
Our goal was to develop a method for generating high-resolution three-dimensional pulmonary compliance images in rodents from computed tomography (CT) images acquired at a series of constant pressures in ventilated animals. One rat and one mouse were used to demonstrate this technique. A pre-clinical GE flat panel CT scanner (maximum 31 line-pairs cm -1 resolution) was utilized for image acquisition. The thorax of each animal was imaged with breath-holds at 2, 6, 10, 14 and 18 cm H 2 O pressure in triplicate. A deformable image registration algorithm was applied to each pair of CT images to map corresponding tissue elements. Pulmonary compliance was calculated on a voxel by voxel basis using adjacent pairs of CT images. Triplicate imaging was used to estimate the measurement error of this technique. The 3D pulmonary compliance images revealed regional heterogeneity of compliance. The maximum total lung compliance measured 0.080 (±0.007) ml air per cm H 2 O per ml of lung and 0.039 (±0.004) ml air per cm H 2 O per ml of lung for the rat and mouse, respectively. In this study, we have demonstrated a unique method of quantifying regional lung compliance from 4 to 16 cm H 2 O pressure with sub-millimetre spatial resolution in rodents
DEFF Research Database (Denmark)
Rusakov, Yury Yu; Krivdin, Leonid B.; Østerstrøm, Freja From
2013-01-01
This paper documents a very first example of a high-level correlated calculation of spin-spin coupling constants involving tellurium taking into account relativistic effects, vibrational corrections and solvent effects for the medium sized organotellurium molecules. The 125Te-1H spin-spin coupling...... constants of tellurophene and divinyl telluride were calculated at the SOPPA and DFT levels in a good agreement with experiment. A new full-electron basis set av3z-J for tellurium derived from the "relativistic" Dyall's basis set, dyall.av3z, and specifically optimized for the correlated calculations...... of spin-spin coupling constants involving tellurium, was developed. The SOPPA methods show much better performance as compared to 15 those of DFT, if relativistic effects calculated within the ZORA scheme are taken into account. Vibrational and solvent corrections are next to negligible, while...
Lattice calculation of heavy-light decay constants with two flavors of dynamical quarks
International Nuclear Information System (INIS)
Bernard, C.; Datta, S.; DeGrand, T.; DeTar, C.; Gottlieb, Steven; Heller, Urs M.; McNeile, C.; Orginos, K.; Sugar, R.; Toussaint, D.
2002-01-01
We present results for f B , f B s , f D , f D s and their ratios in the presence of two flavors of light sea quarks (N f =2). We use Wilson light valence quarks and Wilson and static heavy valence quarks; the sea quarks are simulated with staggered fermions. Additional quenched simulations with nonperturbatively improved clover fermions allow us to improve our control of the continuum extrapolation. For our central values the masses of the sea quarks are not extrapolated to the physical u, d masses; that is, the central values are ''partially quenched.'' A calculation using 'fat-link clover' valence fermions is also discussed but is not included in our final results. We find, for example, f B =190(7)( -17 +24 )( -2 +11 )( -0 +8 ) MeV, f B s /f B =1.16(1)(2)(2)( -0 +4 ), f D s =241(5)( -26 +27 )( -4 +9 )( -0 +5 ) MeV, and f B /f D s =0.79(2)( -4 +5 )(3)( -0 +5 ), where in each case the first error is statistical and the remaining three are systematic: the error within the partially quenched N f =2 approximation, the error due to the missing strange sea quark and to partial quenching, and an estimate of the effects of chiral logarithms at small quark mass. The last error, though quite significant in decay constant ratios, appears to be smaller than has been recently suggested by Kronfeld and Ryan, and Yamada. We emphasize, however, that as in other lattice computations to date, the lattice u,d quark masses are not very light and chiral log effects may not be fully under control
Jianxiu QIN; Huiqiang ZHANG; Bing WANG
2018-01-01
In order to numerically evaluate the acoustic characteristics of liquid rocket engine thrust chambers by means of a computational fluid dynamics method, a mathematical model of an artificial constant-volume bomb is proposed in this paper. A localized pressure pulse with a very high amplitude can be imposed on specified regions in a combustion chamber, the numerical procedure of which is described. Pressure oscillations actuated by the released constant-volume bomb can then be analyzed via Fas...
International Nuclear Information System (INIS)
Tonkonogov, M.P.; Medvedev, V.Ya.
2003-01-01
The formulas for volume charge distribution, complex permittivity, static dielectric constant for the crystals with hydrogen bonds are proposed. With help of the formulas the structure defect concentration, relaxation energy of relaxators were calculated for important electronic and optoelectronic materials as mica, KDP and DKDP crystals, gypsum, talk
Finite volume thermal-hydraulics and neutronics coupled calculations - 15300
International Nuclear Information System (INIS)
Araujo Silva, V.; Campagnole dos Santos, A.A.; Mesquit, A.Z.; Bernal, A.; Miro, R.; Verdu, G.; Pereira, C.
2015-01-01
The computational power available nowadays allows the coupling of neutronics and thermal-hydraulics codes for reactor studies. The present methodology foresees at least one constraint to the separated codes in order to perform coupled calculations: both codes must use the same geometry, however, meshes can be different for each code as long as the internal surfaces stays the same. Using the finite volume technique, a 3D diffusion nodal code was implemented to deal with neutron transport. This code can handle non-structured meshes which allows for complicated geometries calculations and therefore more flexibility. A computational fluid dynamics (CFD) code was used in order to obtain the same level of details for the thermal hydraulics calculations. The chosen code is OpenFOAM, an open-source CFD tool. Changes in OpenFOAM allow simple coupled calculations of a PWR fuel rod with neutron transport code. OpenFOAM sends coolant density information and fuel temperature to the neutron transport code that sends back power information. A mapping function is used to average values when one node in one side corresponds to many nodes in the other side. Data is exchanged between codes by library calls. As the results of a fuel rod calculations progress, more complicated and processing demanding geometries will be simulated, aiming to the simulation of a real scale PWR fuel assembly
Calculation of Steam Volume Fraction in Subcooled Boiling
Energy Technology Data Exchange (ETDEWEB)
Rouhani, S Z
1967-06-15
An analysis of subcooled boiling is presented. It is assumed that heat is removed by vapor generation, heating of the liquid that replaces the detached bubbles, and to some extent by single phase heat transfer. Two regions of subcooled boiling are considered and a criterion is provided for obtaining the limiting value of subcooling between the two regions. Condensation of vapor in the subcooled liquid is analysed and the relative velocity of vapor with respect to the liquid is neglected in these regions. The theoretical arguments result in some equations for the calculation of steam volume fraction and true liquid subcooling.
Squeeze behavior of magnetorheological fluids under constant volume and uniform magnetic field
International Nuclear Information System (INIS)
Guo, Chaoyang; Gong, Xinglong; Xuan, Shouhu; Yan, Qifan; Ruan, Xiaohui
2013-01-01
In this work the experimental investigation of magnetorheological fluids in squeeze mode has been carried out under constant volume with a self-developed device. The magnetorheological fluids were forced to move in all directions in a horizontal plane as the two flat surfaces came together. A pair of Helmholtz coils was used to generate a uniform magnetic field in the compression gap. The normal forces within the gap were systematically studied for different magnetic field, squeeze velocity, particle concentration, viscosity of carrier fluid and initial gap distance. Two regions of behavior were obtained from the normal force versus gap distance curve: elastic deformation and plastic flow. A power law fitting was appropriate for the relation between the normal force and the gap in the plastic flow. The index of the power law was smaller than that predicted by the continuum theory, possibly due to the squeeze strengthening effect and the sealing effect. (paper)
Gas permeation measurement under defined humidity via constant volume/variable pressure method
Jan Roman, Pauls
2012-02-01
Many industrial gas separations in which membrane processes are feasible entail high water vapour contents, as in CO 2-separation from flue gas in carbon capture and storage (CCS), or in biogas/natural gas processing. Studying the effect of water vapour on gas permeability through polymeric membranes is essential for materials design and optimization of these membrane applications. In particular, for amine-based CO 2 selective facilitated transport membranes, water vapour is necessary for carrier-complex formation (Matsuyama et al., 1996; Deng and Hägg, 2010; Liu et al., 2008; Shishatskiy et al., 2010) [1-4]. But also conventional polymeric membrane materials can vary their permeation behaviour due to water-induced swelling (Potreck, 2009) [5]. Here we describe a simple approach to gas permeability measurement in the presence of water vapour, in the form of a modified constant volume/variable pressure method (pressure increase method). © 2011 Elsevier B.V.
PREMIXED FLAME PROPAGATION AND MORPHOLOGY IN A CONSTANT VOLUME COMBUSTION CHAMBER
Energy Technology Data Exchange (ETDEWEB)
Hariharan, A; Wichman, IS
2014-06-04
This work presents an experimental and numerical investigation of premixed flame propagation in a constant volume rectangular channel with an aspect ratio of six (6) that serves as a combustion chamber. Ignition is followed by an accelerating cusped finger-shaped flame-front. A deceleration of the flame is followed by the formation of a "tulip"-shaped flame-front. Eventually, the flame is extinguished when it collides with the cold wall on the opposite channel end. Numerical computations are performed to understand the influence of pressure waves, instabilities, and flow field effects causing changes to the flame structure and morphology. The transient 2D numerical simulation results are compared with transient 3D experimental results. Issues discussed are the appearance of oscillatory motions along the flame front and the influences of gravity on flame structure. An explanation is provided for the formation of the "tulip" shape of the premixed flame front.
Auto-Ignition and Combustion of Diesel Fuel in a Constant-Volume Bomb
Selden, Robert F
1938-01-01
Report presents the results of a study of variations in ignition lag and combustion associated with changes in air temperature and density for a diesel fuel in a constant-volume bomb. The test results have been discussed in terms of engine performance wherever comparisons could be drawn. The most important conclusions drawn from this investigation are: the ignition lag was essentially independent of the injected fuel quantity. Extrapolation of the curves for the fuel used shows that the lag could not be greatly decreased by exceeding the compression-ignition engines. In order to obtain the best combustion and thermal efficiency, it was desirable to use the longest ignition lag consistent with a permissible rate of pressure rise.
A fluctuation method to calculate the third order elastic constants in crystalline solids
Energy Technology Data Exchange (ETDEWEB)
Chen, Zimu [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Qu, Jianmin, E-mail: j-qu@northwestern.edu [Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208 (United States)
2015-05-28
This paper derives exact expressions of the isothermal third order elastic constants (TOE) in crystalline solids in terms of the kinetic and potential energies of the system. These expressions reveal that the TOE constants consist of a Born component and a relaxation component. The Born component is simply the third derivative of the system's potential energy with respect to the deformation, while the relaxation component is related to the non-uniform rearrangements of the atoms when the system is subject to a macroscopic deformation. Further, based on the general expressions derived here, a direct (fluctuation) method of computing the isothermal TOE constants is developed. Numerical examples of using this fluctuation method are given to compute the TOE constants of single crystal iron.
Flow-through electroporation based on constant voltage for large-volume transfection of cells.
Geng, Tao; Zhan, Yihong; Wang, Hsiang-Yu; Witting, Scott R; Cornetta, Kenneth G; Lu, Chang
2010-05-21
Genetic modification of cells is a critical step involved in many cell therapy and gene therapy protocols. In these applications, cell samples of large volume (10(8)-10(9)cells) are often processed for transfection. This poses new challenges for current transfection methods and practices. Here we present a novel flow-through electroporation method for delivery of genes into cells at high flow rates (up to approximately 20 mL/min) based on disposable microfluidic chips, a syringe pump, and a low-cost direct current (DC) power supply that provides a constant voltage. By eliminating pulse generators used in conventional electroporation, we dramatically lowered the cost of the apparatus and improved the stability and consistency of the electroporation field for long-time operation. We tested the delivery of pEFGP-C1 plasmids encoding enhanced green fluorescent protein into Chinese hamster ovary (CHO-K1) cells in the devices of various dimensions and geometries. Cells were mixed with plasmids and then flowed through a fluidic channel continuously while a constant voltage was established across the device. Together with the applied voltage, the geometry and dimensions of the fluidic channel determined the electrical parameters of the electroporation. With the optimal design, approximately 75% of the viable CHO cells were transfected after the procedure. We also generalize the guidelines for scaling up these flow-through electroporation devices. We envision that this technique will serve as a generic and low-cost tool for a variety of clinical applications requiring large volume of transfected cells. Copyright 2010 Elsevier B.V. All rights reserved.
Fuel spray and combustion characteristics of butanol blends in a constant volume combustion chamber
International Nuclear Information System (INIS)
Liu, Yu; Li, Jun; Jin, Chao
2015-01-01
Highlights: • A sudden drop is observed in spray penetration for B10S10D80 fuel at 800 and 900 K. • With increasing of temperature, auto-ignition timings of fuels become unperceivable. • Low n-butanol addition has little effect on autoignition timings from 800 to 1200 K. • n-Butanol additive can reduce soot emissions at the near-wall regions. • Larger soot reduction is seen at higher ambient temperatures for n-butanol addition. - Abstract: The processes of spray penetrations, flame propagation and soot formation and oxidation fueling n-butanol/biodiesel/diesel blends were experimentally investigated in a constant volume combustion chamber with an optical access. B0S20D80 (0% n-butanol, 20% soybean biodiesel, and 80% diesel in volume) was prepared as the base fuel. n-Butanol was added into the base fuel by volumetric percent of 5% and 10%, denoted as B5S15D80 (5% n-butanol/15% soybean biodiesel/80% diesel) and B10S10D80 (10% n-butanol/10% soybean biodiesel/80% diesel). The ambient temperatures at the time of fuel injection were set to 800 K, 900 K, 1000 K, and 1200 K. Results indicate that the penetration length reduces with the increase of n-butanol volumes in blending fuels and ambient temperatures. The spray penetration presents a sudden drop as fueling B10S10D80 at 800 K and 900 K, which might be caused by micro-explosion. A larger premixed combustion process is observed at low ambient temperatures, while the heat release rate of high ambient temperatures presents mixing controlled diffusion combustion. With a lower ambient temperature, the auto-ignition delay becomes longer with increasing of n-butanol volume in blends. However, with increasing of ambient temperatures, the auto-ignition timing between three fuels becomes unperceivable. Generally, low n-butanol addition has a limited or no effect on the auto-ignition timing in the current conditions. Compared with the base fuel of B0S20D80, n-butanol additive with 5% or 10% in volume can reduce soot
Diffusion constant in hot and dense hadronic matter. A hadro-molecular-dynamic calculation
International Nuclear Information System (INIS)
Sasaki, N.; Miyamura, O.; Muroya, S.; Nonaka, C.
2002-01-01
We evaluate baryon/charge diffusion constant of dense and hot hadronic matter based on the molecular dynamical method by using a hadronic collision generator which describes nuclear collisions at energies 10 1-2 GeV/A and satisfies detailed balance at low temperatures (T ≤ 200 MeV). For the hot and dense hadronic matter of the temperature range, T = 100 - 200 MeV and baryon number density, n B =0.16 fm -3 - 0.32 fm -3 , charge diffusion constant D gradually increases from 0.5 fmc to 2 fmc with temperature and is almost independent of baryon number density. Based on the obtained diffusion constant we make simple discussions on the diffusion of charge fluctuation in ultrarelativistic nuclear collisions. (author)
International Nuclear Information System (INIS)
Raskach, K. F.
2012-01-01
In multigroup calculations of reactivity and sensitivity coefficients, methodical errors can appear if the interdependence of multigroup constants is not taken into account. For this effect to be taken into account, so-called implicit components of the aforementioned values are introduced. A simple technique for computing these values is proposed. It is based on the use of subgroup parameters.
Papanastasiou, G; Ziogas, I
1995-06-01
New iterative methods for analysis of potentiometric titration data of (a) mixtures of weak monoprotic acids with their conjugate bases, (b) solutions of polyprotic (di- and triprotic) acids, and (c) mixtures of two diprotic acids are presented. These methods, using data exclusively resulting from the acidic region of the titration curve permits the accurate determination of the analytical concentration of one or more acids even if the titration is stopped well before the end point of the titration. For the titration of a solution containing a conjugate acid/base pair, the proposed procedure enables the extraction of the initial composition of the mixture, as well as the dissociation constant of the concerned acid. Thus, it is possible by this type of analysis to distinguish whether a weak acid has been contaminated by a strong base and define the extent of the contamination. On the other hand, for the titration of polyprotic acids, the proposed approach enables the extraction of the accurate values of the equivalence volume and the dissociation constants K(i) even when the ionization stages overlap. Finally, for the titration of a mixture of two diprotic acids the proposed procedure enables the determination of the composition of the mixture even if the sum of the concentrations of the acids is not known. This method can be used in the analysis of solutions containing two diastereoisomeric forms of a weak diprotic acid. The test of the proposed procedures by means of ideal and Monte Carlo simulated data revealed that these methods are fairly applicable even when the titration data are considerably obscured by 'noise' or contain an important systematic error. The proposed procedures were also successfully applied to experimental titration data.
Direct quantum mechanical calculation of the F + H{sub 2} {yields} HF + H thermal rate constant
Energy Technology Data Exchange (ETDEWEB)
Moix, Marc [Computer Simulation and Modeling (COSMO) Lab, Parc Cientific de Barcelona, Josep Samitier 5, 08028 Barcelona (Spain); Institut de Quimica Teorica i Computacional de la UB (IQTCUB), Universitat de Barcelona (Spain); Huarte-Larranaga, Fermin [Computer Simulation and Modeling (COSMO) Lab, Parc Cientific de Barcelona, Josep Samitier 5, 08028 Barcelona (Spain); Institut de Quimica Teorica i Computacional de la UB (IQTCUB), Universitat de Barcelona (Spain)], E-mail: fhuarte@pcb.ub.es
2008-07-03
Accurate full-dimensional quantum mechanical thermal rate constant values have been calculated for the F+H{sub 2}{yields}HF+H reaction on the Stark-Werner ab initio potential energy surface. These calculations are based on a flux correlation functions and employ a rigorous statistical sampling scheme to account for the overall rotation and the MCTDH scheme for the wave packet propagation. Our results shed some light on discrepancies on the thermal rate found for previous flux correlation based calculations with respect to accurate reactive scattering results. The resonance pattern of the all-J cumulative reaction probability is analyzed in terms of the partial wave contributions.
Calculation of anisotropic few-group constants in asymptotic cells: the code ANICELL
International Nuclear Information System (INIS)
Devenyi, A.
1985-10-01
The theoretical background of the ANICELL computer program together with a user's manual is presented. ANICELL is a nuclear reactor neutron transport code which solves the traditional asymptotic and the so-called tilted flux transport problems in one-dimensional cylindrical geometry using linearly anisotropic scattering. The method of solution used is the first flight collision probability technique. Few-group constants including radial and axial diffusion coefficients for the cell are also prepared by the program. (author)
International Nuclear Information System (INIS)
Erpenbeck, J.J.
1987-01-01
We apply the so-called ''synthetic'' nonequilibrium molecular-dynamics method to the calculation of the self-diffusion constant of a Lennard-Jones fluid at a number density of 0.85/σ 3 and a temperature of 1.08 epsilon-c/k/sub B/ (where epsilon-c and σ are the energy and length parameters of the potential and k/sub B/ is the Boltzmann constant). By comparing with the Green-Kubo calculation for the same state of the system and for the same number of particles, N, we find the latter calculation to yield more precise values of the self-diffusion constant for a given number of molecular-dynamics time steps. Even at small values of the diffusion current, a nontrivial time is needed for the nonequilibrium calculation to reach the steady state. For larger values of the driving force, the steady-state flow appears to become unstable and evidence of a secondary flow pattern is presented. The presence of these instabilities acts as a limit to the range of the driving force for which the steady-state method can be applied. With increasing N the range of stable values of the diffusion current density decreases. For the Green-Kubo calculations, the N dependence of the self-diffusion constant is found to be anomalous for N = 108, with the 1/N dependence only exhibited for at least 500 particles. The nonequilibrium results, while approximately independent of N for 108 and 500 particles, are found to have a similar anomalous N dependence when we extend the calculations to 1372 particles, thereby bringing the Green-Kubo and nonequilibrium results into agreement in the large-system limit
Wolk, Benjamin
2013-07-01
The enhancement of laminar flame development using microwave-assisted spark ignition has been investigated for methane-air mixtures at a range of initial pressures and equivalence ratios in a 1.45. l constant volume combustion chamber. Microwave enhancement was evaluated on the basis of several parameters including flame development time (FDT) (time for 0-10% of total net heat release), flame rise time (FRT) (time for 10-90% of total net heat release), total net heat release, flame kernel growth rate, flame kernel size, and ignitability limit extension. Compared to a capacitive discharge spark, microwave-assisted spark ignition extended the lean and rich ignition limits at all pressures investigated (1.08-7.22. bar). The addition of microwaves to a capacitive discharge spark reduced FDT and increased the flame kernel size for all equivalence ratios tested and resulted in increases in the spatial flame speed for sufficiently lean flames. Flame enhancement is believed to be caused by (1) a non-thermal chemical kinetic enhancement from energy deposition to free electrons in the flame front and (2) induced flame wrinkling from excitation of flame (plasma) instability. The enhancement of flame development by microwaves diminishes as the initial pressure of the mixture increases, with negligible flame enhancement observed above 3. bar. © 2013 The Combustion Institute.
The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber
Firmansyah; Aziz, A. R. A.; Heikal, M. R.
2015-12-01
The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.
Laser-assisted homogeneous charge ignition in a constant volume combustion chamber
Srivastava, Dhananjay Kumar; Weinrotter, Martin; Kofler, Henrich; Agarwal, Avinash Kumar; Wintner, Ernst
2009-06-01
Homogeneous charge compression ignition (HCCI) is a very promising future combustion concept for internal combustion engines. There are several technical difficulties associated with this concept, and precisely controlling the start of auto-ignition is the most prominent of them. In this paper, a novel concept to control the start of auto-ignition is presented. The concept is based on the fact that most HCCI engines are operated with high exhaust gas recirculation (EGR) rates in order to slow-down the fast combustion processes. Recirculated exhaust gas contains combustion products including moisture, which has a relative peak of the absorption coefficient around 3 μm. These water molecules absorb the incident erbium laser radiations ( λ=2.79 μm) and get heated up to expedite ignition. In the present experimental work, auto-ignition conditions are locally attained in an experimental constant volume combustion chamber under simulated EGR conditions. Taking advantage of this feature, the time when the mixture is thought to "auto-ignite" could be adjusted/controlled by the laser pulse width optimisation, followed by its resonant absorption by water molecules present in recirculated exhaust gas.
Directory of Open Access Journals (Sweden)
Jianxiu QIN
2018-03-01
Full Text Available In order to numerically evaluate the acoustic characteristics of liquid rocket engine thrust chambers by means of a computational fluid dynamics method, a mathematical model of an artificial constant-volume bomb is proposed in this paper. A localized pressure pulse with a very high amplitude can be imposed on specified regions in a combustion chamber, the numerical procedure of which is described. Pressure oscillations actuated by the released constant-volume bomb can then be analyzed via Fast Fourier Transformation (FFT, and their modes can be identified according to the theoretical acoustic eigenfrequencies of the thrust chamber. The damping performances of the corresponding acoustic modes are evaluated by the half-power bandwidth method. The predicted acoustic characteristics and their damping for a special engine combustor agree well with the experimental data, validating the mathematical model and its numerical procedures. A small-thrust liquid rocket engine chamber is then analyzed by the present model. The First Longitudinal (1L acoustic mode can be excited easily and is hard to be damped. The axial position of the central constant-volume bomb has little influence on the amplitude and damping capacity of the First Radial (1R and 1L acoustic modes. Tangential acoustic modes can only be triggered by an off-centered constant-volume bomb, among which the First Tangential (1T mode is the strongest and regarded as the most harmful one. The amplitude of the 1L acoustic mode is smaller, but its damping factor is larger, as a constant-volume bomb is imposed approaching the injector face. These results are contributed to evaluate the acoustic characteristics and their damping of the combustion chamber. Keywords: Acoustic mode, Constant-volume bomb, Damping characteristics, Damping factor, Half-power bandwidth, Pressure oscillation
Impact of pore-pressure cycling on bentonite in constant volume experiments
International Nuclear Information System (INIS)
Graham, C.C.; Harrington, J.F.; Cuss, R.J.; Sellin, P.
2012-01-01
Document available in extended abstract form only. The SKB safety case for a KBS-3 repository highlights the potential importance of future successive glaciation events on repository functions. One particular uncertainty is the likely affect of elevated pore-water pressures on barrier safety functions. Over the repository lifetime such changes in pore-water pressure are likely to be cyclic in nature, as successive glacial episodes lead to loading and unloading of the engineered barrier. For a clay-water system with the pore-water in thermodynamic equilibrium with an external reservoir of water at pressure, p w , the total stress acting on the surrounding vessel can be expressed as: (1) σ = Π + αp w where Π is the swelling pressure and α is a proportionality constant. We present results from a series of laboratory experiments designed to investigate this relationship, in the context of glacial loading. Blocks of pre-compacted Mx80 bentonite were manufactured by Clay Technology AB (Lund, Sweden), by rapidly compacting bentonite granules in a mould under a one dimensionally applied stress (Johannesson et al., 1995). The blocks were then sub-sampled and cylindrical specimens prepared for testing (120 mm in length and 60 mm in diameter). The experiments were conducted using a specially designed constant volume cell, which allows the evolution of the total stresses acting on the surrounding vessel to be monitored during clay swelling (at three radial and two axial locations). A high precision syringe pump was used to maintain a constant applied pore pressure within the bentonite, while the rate of hydraulic inflow, and consequent stress development, were monitored to determine the point at which hydraulic equilibrium was reached. During the tests each sample was subjected to an incremental series of constant pore-pressure steps, with all samples experiencing at least one loading and unloading cycle. The resulting average total stress data yield alpha values in the
Self-consistent calculation of the coupling constant in the Gross-Pitaevskii equation
International Nuclear Information System (INIS)
Cherny, A.Yu.; Brand, J.
2004-01-01
A method is proposed for a self-consistent evaluation of the coupling constant in the Gross-Pitaevskii equation without involving a pseudopotential replacement. A renormalization of the coupling constant occurs due to medium effects and the trapping potential, e.g., in quasi-1D or quasi-2D systems. It is shown that a simplified version of the Hartree-Fock-Bogoliubov approximation leads to a variational problem for both the condensate and a two-body wave function describing the behavior of a pair of bosons in the Bose-Einstein condensate. The resulting coupled equations are free of unphysical divergences. Particular cases of this scheme that admit analytical estimations are considered and compared to the literature. In addition to the well-known cases of low-dimensional trapping, crossover regimes can be studied. The values of the kinetic, interaction, external, and release energies in low dimensions are also evaluated and contributions due to short-range correlations are found to be substantial
A modified Poisson-Boltzmann surface excess calculation with a field dependent dielectric constant
International Nuclear Information System (INIS)
Gordillo, G.J.; Molina, F.V.; Posadas, D.
1990-01-01
The Unequal Radius Modified Gouy-Chapman (URMGC) was applied to mixtures of electrolytes. It was considered that the two anions, (1) and (2), have different radius, r 1 and r 2 , being r 2 smaller than r 1 . The dielectric constant was taken as a function of the electric field, using the theoretical Booth equation, or as a linear dependence varying between 6 and 78 when r 2 1 . The results show that the surface excess of anion 2 is much greater than the one predicted by Gouy-Chapman theory when the proportion of 2 increases in the mixture, while both the other anion and the cation show negative deviation. This effect is more evident in mixtures than in the case of single electrolytes, and has a maximum for a composition that depends on the chosen parameters for the model. (Author) [es
The Energy Implications of Air-Side Fouling in Constant Air Volume HVAC Systems
Wilson, Eric J. H.
2011-12-01
This thesis examines the effect of air-side fouling on the energy consumption of constant air volume (CAV) heating, ventilating, and air conditioning (HVAC) systems in residential and small commercial buildings. There is a particular focus on evaluating the potential energy savings that may result from the remediation of such fouling from coils, filters, and other air system components. A computer model was constructed to simulate the behavior of a building and its duct system under various levels of fouling. The model was verified through laboratory and field testing and then used to run parametric simulations to examine the range of energy impacts for various climates and duct system characteristics. A sensitivity analysis was conducted to determine the impact of parameters like duct insulation, duct leakage, duct location, and duct design on savings potential. Duct system pressures, temperatures, and energy consumption for two houses were monitored for one month. The houses' duct systems, which were both in conditioned space, were given a full cleaning, and were then monitored for another month. The flow rates at the houses improved by 10% and 6%. The improvements were primarily due to installing a new filter, as both houses had only light coil fouling. The results indicate that there was negligible change in heating energy efficiency due to the system cleaning. The parametric simulation results are in agreement with the field experiment: for systems in all eight climates, with flowrates degraded by 20% or less, if ducts are located within the thermal zone, HVAC source energy savings from cleaning are negligible or even slightly negative. However, if ducts are outside the thermal zone, savings are in the 1 to 5% range. For systems with flowrates degraded by 40%, if ducts are within the thermal zone, savings from cleaning occurs only for air conditioning energy, up to 8% in climates like Miami, FL. If ducts are outside the thermal zone, savings occurs with both
Calculation of the mean force constants of the rare gases and the rectilinear law of mean force
International Nuclear Information System (INIS)
Lee, M.W.; Bigeleisen, J.
1977-01-01
The mean energies, (U), and the mean force constants, (nabla 2 U), have been calculated for liquid argon and liquid krypton using the WCA perturbation theory, and for gaseous argon and krypton along the coexistence line by solution of the PY equation for the radial distribution function. Calculations have been made for the Lennard-Jones, Barker-Henderson, and Maitland-Smith potentials. There is little difference in the values of (U) and (nabla 2 U) calculated for the three potentials. The calculated values are in good agreement with experimental data. Correlation of the calculated values of (nabla 2 U) for the liquid and gas leads to an empirical relationship between (nabla 2 U) and the density of the phase along the coexistence line. When the latter is combined with the law of rectilinear diameters of the density, the rectilinear law of mean force is obtained, which is in good agreement with experimental data on argon. It is shown that the scaling exponent for the mean force constant, (nabla 2 U)/sub l/-(nabla 2 U)/sub g/, is larger than the scaling exponent of the density below the critical temperature and becomes equal to it at the critical temperature. The rationale for the rectilinear law of mean force is provided by an expansion of the radial distribution function of the liquid in powers of the density and the use of the WCA approximation to the radial distribution function
International Nuclear Information System (INIS)
Vidal-Vidal, Á.; Pérez-Rodríguez, M.; Piñeiro, M.M.
2017-01-01
Highlights: • OCS hydrolysis equilibrium constants were calculated using QM composite methods. • CBS-QB3 was found to be the most adequate method for OCS thermodynamic calculations. • Calculated hydrolysis yields decrease when temperature increases. • The isotopic effect is less significant than temperature or initial concentration dependences. - Abstract: Carbonyl sulphide is the predominant sulphur compound in the atmosphere, contributing to the formation of aerosol particles affecting global climate. Human activity has significantly increased its total amount since the beginning of the Industrial Revolution due to its presence in petroleum and coal, reason why it is necessary to understand and control its emissions. On the other hand, carbonyl sulphide is an undesired substance for catalysis in important industrial processes. Hydrolysis is the most promising among the different strategies to reduce its presence, giving as products carbon dioxide and hydrogen sulphide. In the present work, the mechanism of reaction of carbonyl sulphide hydrolysis process in gas phase was studied from 400 K to 1500 K, equilibrium constants were obtained and reaction yields were estimated, by means of composite quantum-computational methods. Good agreement with literature experimental results confirms the suitability of the chosen methods, specially CBS-QB3, in supporting the reaction mechanism, giving accurate equilibrium constant values, and obtaining realistic yields. The effect of isotopic substitution in OCS was also studied, from 300 K to 1500 K, being much less significant than temperature dependence.
Volume-based geometric modeling for radiation transport calculations
International Nuclear Information System (INIS)
Li, Z.; Williamson, J.F.
1992-01-01
Accurate theoretical characterization of radiation fields is a valuable tool in the design of complex systems, such as linac heads and intracavitary applicators, and for generation of basic dose calculation data that is inaccessible to experimental measurement. Both Monte Carlo and deterministic solutions to such problems require a system for accurately modeling complex 3-D geometries that supports ray tracing, point and segment classification, and 2-D graphical representation. Previous combinatorial approaches to solid modeling, which involve describing complex structures as set-theoretic combinations of simple objects, are limited in their ease of use and place unrealistic constraints on the geometric relations between objects such as excluding common boundaries. A new approach to volume-based solid modeling has been developed which is based upon topologically consistent definitions of boundary, interior, and exterior of a region. From these definitions, FORTRAN union, intersection, and difference routines have been developed that allow involuted and deeply nested structures to be described as set-theoretic combinations of ellipsoids, elliptic cylinders, prisms, cones, and planes that accommodate shared boundaries. Line segments between adjacent intersections on a trajectory are assigned to the appropriate region by a novel sorting algorithm that generalizes upon Siddon's approach. Two 2-D graphic display tools are developed to help the debugging of a given geometric model. In this paper, the mathematical basis of our system is described, it is contrasted to other approaches, and examples are discussed
FOREST STEM VOLUME CALCULATION USING AIRBORNE LIDAR DATA
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I. Büyüksalih
2017-05-01
Full Text Available Airborne LiDAR data have been collected for the city of Istanbul using Riegl laser scanner Q680i with 400 kHz and an average flight height of 600 m. The flight campaign was performed by a helicopter and covers an area of 5400 km2. According to a flight speed of 80 knot a point density of more than 16 points/m2 and a laser footprint size of 30 cm could be achieved. As a result of bundle adjustment, in total, approximately 17,000 LAS files with the file size of 500 m by 700 m have been generated for the whole city. The main object classes Ground, Building, Vegetation (medium, high were derived from these LAS files using the macros in Terrasolid software. The forest area under investigation is located northwest of the city of Istanbul, main tree species occurring in the test site are pine (pinus pinaster, oak (quercus and beech (fagus. In total, 120 LAS tiles covering the investigation area have been analysed using the software IMPACT of Joanneum Research Forschungsgesellschaft, Graz, Austria. First of all, the digital terrain model (DTM and the digital surface models (DSM were imported and converted into a raster file from the original laser point clouds with a spatial resolution of 50 cm. Then, a normalized digital surface model (nDSM was derived as the difference between DSM and the DTM. Tree top detection was performed by multi – resolution filter operations and tree crowns were segmented by a region growing algorithms develop specifically for this purpose. Breast Height Diameter (BHD was calculated on the base of tree height and crown areas derived from image segmentation applying allometric functions found in literature. The assessment of stem volume was then calculated as a function of tree height and BHD. A comparison of timber volume estimated from the LiDAR data and field plots measured by the Forest Department of Istanbul showed R2 of 0.46. The low correlation might arise either from the low quality of the field plots or
Zhang, Ji; Jing, Wei; Roberts, William L.; Fang, Tiegang
2013-01-01
This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm
Calculating the Ionization Constant of Functional Groups of Carboxyl Ion Exchangers
Meychik, N. R.; Stepanov, S. I.; Nikolaeva, Yu. I.
2018-02-01
The potentiometric titration of a weakly basic carboxyl cation exchanger, obtained via alkaline hydrolysis of an acrylonitrile copolymer with divinyl benzene (degree of crosslinking, 12%) in a wide range of variation in a solution of pH (2-12) and NaCl (concentration 0.01, 0.1, 0.5, 1 M), is considered. The maximum ion-exchange capacity of the ion exchanger for Na+ is determined (10.10 ± 0.088 mmol/g of the dry mass) and found to be independent of the solution's ionic strength. It is established that in the investigated range of NaCl concentrations and pH, the acid-base balance is adequately described by Gregor's equation. The parameters of this equation are calculated as a function of the NaCl concentration: p K a = 8.13 ± 0.04, n = 1.50 ± 0.02 for 0.01 M; p K a = 6.56 ± 0.04, n = 2.60 ± 0.07 for 0.1 M; and p K a = 5.66 ± 0.6, n = 2.62 ± 0.06 for 0.5 and 1 M. It is shown that to describe the acid-base balance correctly within the proposed model we must estimate the adequacy of the experimental and calculated values of the ion exchanger's capacity at each pH value according to the calculated parameters of Gregor's equation.
Calculation of hyperfine constants for the H center in LiF
International Nuclear Information System (INIS)
Alencar, P.T.S.
1975-01-01
The EPR and the ENDOR hyperfine parameters for the H center in LiF are calculated assuming that the F - 2 central molecule is a simplified model for the electronic structure of this deffect. The best theoretical fitting was obtained by relaxing the ions neighboring the central molecule. We have obtained relaxations which are in agreement with the physical nature of this deffect, but for some ions the results have shown that a better wave functions for the unpaired electrons must be used. The results and the limitations of the suggested model, are discussed proposing a more realistic description for the deffect, than the F - 2 central molecule model
International Nuclear Information System (INIS)
Dunning, T.H. Jr.; Peterson, K.A.
1998-01-01
The convergence of Moeller - Plesset perturbation expansions (MP2 - MP4/MP5) for the spectroscopic constants of a selected set of diatomic molecules (BH, CH, HF, N 2 , CO, and F 2 ) has been investigated. It was found that the second-order perturbation contributions to the spectroscopic constants are strongly dependent on basis set, more so for HF and CO than for BH. The MP5 contributions for HF were essentially zero for the cc-pVDZ basis set, but increased significantly with basis set illustrating the difficulty of using small basis sets as benchmarks for correlated calculations. The convergence behavior of the exact Moeller - Plesset perturbation expansions were investigated using estimates of the complete basis set limits obtained using large correlation consistent basis sets. For BH and CH, the perturbation expansions of the spectroscopic constants converge monotonically toward the experimental values, while for HF, N 2 , CO, and F 2 , the expansions oscillate about the experimental values. The perturbation expansions are, in general, only slowly converging and, for HF, N 2 , CO, and F 2 , appear to be far from convergence at MP4. In fact, for HF, N 2 , and CO, the errors in the calculated spectroscopic constants for the MP4 method are larger than those for the MP2 method (the only exception is D e ). The current study, combined with other recent studies, raises serious doubts about the use of Moeller - Plesset perturbation theory to describe electron correlation effects in atomic and molecular calculations. copyright 1998 American Institute of Physics
Lunt, A. J. G.; Xie, M. Y.; Baimpas, N.; Zhang, S. Y.; Kabra, S.; Kelleher, J.; Neo, T. K.; Korsunsky, A. M.
2014-08-01
Yttria Stabilised Zirconia (YSZ) is a tough, phase-transforming ceramic that finds use in a wide range of commercial applications from dental prostheses to thermal barrier coatings. Micromechanical modelling of phase transformation can deliver reliable predictions in terms of the influence of temperature and stress. However, models must rely on the accurate knowledge of single crystal elastic stiffness constants. Some techniques for elastic stiffness determination are well-established. The most popular of these involve exploiting frequency shifts and phase velocities of acoustic waves. However, the application of these techniques to YSZ can be problematic due to the micro-twinning observed in larger crystals. Here, we propose an alternative approach based on selective elastic strain sampling (e.g., by diffraction) of grain ensembles sharing certain orientation, and the prediction of the same quantities by polycrystalline modelling, for example, the Reuss or Voigt average. The inverse problem arises consisting of adjusting the single crystal stiffness matrix to match the polycrystal predictions to observations. In the present model-matching study, we sought to determine the single crystal stiffness matrix of tetragonal YSZ using the results of time-of-flight neutron diffraction obtained from an in situ compression experiment and Finite Element modelling of the deformation of polycrystalline tetragonal YSZ. The best match between the model predictions and observations was obtained for the optimized stiffness values of C11 = 451, C33 = 302, C44 = 39, C66 = 82, C12 = 240, and C13 = 50 (units: GPa). Considering the significant amount of scatter in the published literature data, our result appears reasonably consistent.
Energy Technology Data Exchange (ETDEWEB)
Lunt, A. J. G., E-mail: alexander.lunt@eng.ox.ac.uk; Xie, M. Y.; Baimpas, N.; Korsunsky, A. M. [Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ (United Kingdom); Zhang, S. Y.; Kabra, S.; Kelleher, J. [ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX (United Kingdom); Neo, T. K. [Specialist Dental Group, Mount Elizabeth Orchard, 3 Mount Elizabeth, #08-03/08-08/08-10, Singapore 228510 (Singapore)
2014-08-07
Yttria Stabilised Zirconia (YSZ) is a tough, phase-transforming ceramic that finds use in a wide range of commercial applications from dental prostheses to thermal barrier coatings. Micromechanical modelling of phase transformation can deliver reliable predictions in terms of the influence of temperature and stress. However, models must rely on the accurate knowledge of single crystal elastic stiffness constants. Some techniques for elastic stiffness determination are well-established. The most popular of these involve exploiting frequency shifts and phase velocities of acoustic waves. However, the application of these techniques to YSZ can be problematic due to the micro-twinning observed in larger crystals. Here, we propose an alternative approach based on selective elastic strain sampling (e.g., by diffraction) of grain ensembles sharing certain orientation, and the prediction of the same quantities by polycrystalline modelling, for example, the Reuss or Voigt average. The inverse problem arises consisting of adjusting the single crystal stiffness matrix to match the polycrystal predictions to observations. In the present model-matching study, we sought to determine the single crystal stiffness matrix of tetragonal YSZ using the results of time-of-flight neutron diffraction obtained from an in situ compression experiment and Finite Element modelling of the deformation of polycrystalline tetragonal YSZ. The best match between the model predictions and observations was obtained for the optimized stiffness values of C11 = 451, C33 = 302, C44 = 39, C66 = 82, C12 = 240, and C13 = 50 (units: GPa). Considering the significant amount of scatter in the published literature data, our result appears reasonably consistent.
NULIF: neutron spectrum generator, few-group constant calculator, and fuel depletion code
International Nuclear Information System (INIS)
Wittkopf, W.A.; Tilford, J.M.; Andrews, J.B. II; Kirschner, G.; Hassan, N.M.; Colpo, P.N.
1977-02-01
The NULIF code generates a microgroup neutron spectrum and calculates spectrum-weighted few-group parameters for use in a spatial diffusion code. A wide variety of fuel cells, non-fuel cells, and fuel lattices, typical of PWR (or BWR) lattices, are treated. A fuel depletion routine and change card capability allow a broad range of problems to be studied. Coefficient variation with fuel burnup, fuel temperature change, moderator temperature change, soluble boron concentration change, burnable poison variation, and control rod insertion are readily obtained. Heterogeneous effects, including resonance shielding and thermal flux depressions, are treated. Coefficients are obtained for one thermal group and up to three epithermal groups. A special output routine writes the few-group coefficient data in specified format on an output tape for automated fitting in the PDQ07-HARMONY system of spatial diffusion-depletion codes
International Nuclear Information System (INIS)
Simpkin, D.J.
1989-01-01
A Monte Carlo calculation has been performed to determine the transmission of broad constant-potential x-ray beams through Pb, concrete, gypsum wallboard, steel and plate glass. The EGS4 code system was used with a simple broad-beam geometric model to generate exposure transmission curves for published 70, 100, 120 and 140-kVcp x-ray spectra. These curves are compared to measured three-phase generated x-ray transmission data in the literature and found to be reasonable. For calculation ease the data are fit to an equation previously shown to describe such curves quite well. These calculated transmission data are then used to create three-phase shielding tables for Pb and concrete, as well as other materials not available in Report No. 49 of the NCRP
Simpkin, D J
1989-02-01
A Monte Carlo calculation has been performed to determine the transmission of broad constant-potential x-ray beams through Pb, concrete, gypsum wallboard, steel and plate glass. The EGS4 code system was used with a simple broad-beam geometric model to generate exposure transmission curves for published 70, 100, 120 and 140-kVcp x-ray spectra. These curves are compared to measured three-phase generated x-ray transmission data in the literature and found to be reasonable. For calculation ease the data are fit to an equation previously shown to describe such curves quite well. These calculated transmission data are then used to create three-phase shielding tables for Pb and concrete, as well as other materials not available in Report No. 49 of the NCRP.
Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber
Jing, Wei
2015-01-01
This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2 concentrations were used, spanning 10-21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH∗ with the increase of ambient temperature and O2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O2 concentration conditions by the
International Nuclear Information System (INIS)
Chatterjee, P.; Chatterjee, S.
1978-01-01
The theoretical formula of McMillan has been very successful in explaining the superconducting transition temperature. In this theory the electron-phonon coupling constant was very difficult to calculate from a purely theoretical stand point until Gyorffy and Gaspari gave a theoretical formulation from the multiple scattering point of view. This theory has been very successful in explaining Tsub(c) of many superconducting elements and compounds. For the disordered solid, such as substitution alloys, this theory fails because of the breakdown of the translational symmetry used in the multiple scattering theory of Gyorffy and Gaspari. This problem can however be solved if we average the Green's function in random phase approximation (ATA). In this work we have reformulated Gyorffy and Gaspari's expression of the electron phonon coupling constant in the random phase approximation. This theory has been utilised to alloys of Nb and Mo with different concentrations. The agreement between theory and experiment appears to be very good. (author)
Element-specific and constant parameters used for dose calculations in SR-Site
International Nuclear Information System (INIS)
Norden, Sara; Avila, Rodolfo; De la Cruz, Idalmis; Stenberg, Kristofer; Grolander, Sara
2010-12-01
The report presents Best Estimate (BE) values and Probability Distribution Functions (PDFs) of Concentration Ratios (CR) for different types of terrestrial and aquatic biota and distribution coefficients (K d ) for organic and inorganic deposits, as well as for suspended matter in freshwater and marine ecosystems. The BE values have been used in deterministic simulations for derivation of Landscape Dose Factors (LDF) applied for dose assessments in SR-Site. The PDFs have been used in probabilistic simulations for uncertainty and sensitivity analysis of the LDFs. The derivation of LDFs for SR-Site is described in /Avila et al. 2010/. The CR and K d values have been derived using both site-specific data measured at Laxemar and Forsmark during the site investigation program and literature data. These two data sources have been combined using Bayesian updating methods, which are described in detail in an Appendix, along with the input data used in the statistical analyses and the results obtained. The report also describes a kinetic-allometric model that was applied for deriving values of CR for terrestrial herbivores in cases when site and literature data for an element were missing. In addition, the report presents values for a number of other parameters used in the SR-Site Radionuclide Model for the biosphere: radionuclide decay-ingrowth data, elemental diffusivities, fractions of element content released during decomposition processes, ingestion of food, water and soil by cattle, elements retention fraction on plant surfaces during irrigation. The report also presents parameter values used in calculation of doses to a reference man: dose coefficients for inhalation, ingestion and external exposure, inhalation rates, ingestion rates of food and water
Element-specific and constant parameters used for dose calculations in SR-Site
Energy Technology Data Exchange (ETDEWEB)
Norden, Sara (Svensk Kaernbraenslehantering AB (Sweden)); Avila, Rodolfo; De la Cruz, Idalmis; Stenberg, Kristofer; Grolander, Sara (Facilia AB (Sweden))
2010-12-15
The report presents Best Estimate (BE) values and Probability Distribution Functions (PDFs) of Concentration Ratios (CR) for different types of terrestrial and aquatic biota and distribution coefficients (K{sub d}) for organic and inorganic deposits, as well as for suspended matter in freshwater and marine ecosystems. The BE values have been used in deterministic simulations for derivation of Landscape Dose Factors (LDF) applied for dose assessments in SR-Site. The PDFs have been used in probabilistic simulations for uncertainty and sensitivity analysis of the LDFs. The derivation of LDFs for SR-Site is described in /Avila et al. 2010/. The CR and K{sub d} values have been derived using both site-specific data measured at Laxemar and Forsmark during the site investigation program and literature data. These two data sources have been combined using Bayesian updating methods, which are described in detail in an Appendix, along with the input data used in the statistical analyses and the results obtained. The report also describes a kinetic-allometric model that was applied for deriving values of CR for terrestrial herbivores in cases when site and literature data for an element were missing. In addition, the report presents values for a number of other parameters used in the SR-Site Radionuclide Model for the biosphere: radionuclide decay-ingrowth data, elemental diffusivities, fractions of element content released during decomposition processes, ingestion of food, water and soil by cattle, elements retention fraction on plant surfaces during irrigation. The report also presents parameter values used in calculation of doses to a reference man: dose coefficients for inhalation, ingestion and external exposure, inhalation rates, ingestion rates of food and water
Directory of Open Access Journals (Sweden)
C. Wang
2017-06-01
Full Text Available Gas–particle partitioning governs the distribution, removal, and transport of organic compounds in the atmosphere and the formation of secondary organic aerosol (SOA. The large variety of atmospheric species and their wide range of properties make predicting this partitioning equilibrium challenging. Here we expand on earlier work and predict gas–organic and gas–aqueous phase partitioning coefficients for 3414 atmospherically relevant molecules using COSMOtherm, SPARC Performs Automated Reasoning in Chemistry (SPARC, and poly-parameter linear free-energy relationships. The Master Chemical Mechanism generated the structures by oxidizing primary emitted volatile organic compounds. Predictions for gas–organic phase partitioning coefficients (KWIOM/G by different methods are on average within 1 order of magnitude of each other, irrespective of the numbers of functional groups, except for predictions by COSMOtherm and SPARC for compounds with more than three functional groups, which have a slightly higher discrepancy. Discrepancies between predictions of gas–aqueous partitioning (KW/G are much larger and increase with the number of functional groups in the molecule. In particular, COSMOtherm often predicts much lower KW/G for highly functionalized compounds than the other methods. While the quantum-chemistry-based COSMOtherm accounts for the influence of intra-molecular interactions on conformation, highly functionalized molecules likely fall outside of the applicability domain of the other techniques, which at least in part rely on empirical data for calibration. Further analysis suggests that atmospheric phase distribution calculations are sensitive to the partitioning coefficient estimation method, in particular to the estimated value of KW/G. The large uncertainty in KW/G predictions for highly functionalized organic compounds needs to be resolved to improve the quantitative treatment of SOA formation.
Yoshizawa, Terutaka; Zou, Wenli; Cremer, Dieter
2017-04-01
A new method for calculating nuclear magnetic resonance shielding constants of relativistic atoms based on the two-component (2c), spin-orbit coupling including Dirac-exact NESC (Normalized Elimination of the Small Component) approach is developed where each term of the diamagnetic and paramagnetic contribution to the isotropic shielding constant σi s o is expressed in terms of analytical energy derivatives with regard to the magnetic field B and the nuclear magnetic moment 𝝁 . The picture change caused by renormalization of the wave function is correctly described. 2c-NESC/HF (Hartree-Fock) results for the σiso values of 13 atoms with a closed shell ground state reveal a deviation from 4c-DHF (Dirac-HF) values by 0.01%-0.76%. Since the 2-electron part is effectively calculated using a modified screened nuclear shielding approach, the calculation is efficient and based on a series of matrix manipulations scaling with (2M)3 (M: number of basis functions).
Selected articles translated from Jadernye Konstanty (Nuclear Constants) volume 1, 1996
International Nuclear Information System (INIS)
1997-08-01
This report contains selected articles translated from Jedernye Konstanty (Nuclear Constants). Eight papers are included and each one is separately indexed. Nuclear data libraries, Neutron Reactions, Low energy Photofission etc. are dealt with. Refs, figs, tabs
International Nuclear Information System (INIS)
Trudeau, J.D.; Schwartz, J.L.; Farrar, T.C.
1991-01-01
The deuterium quadrupole coupling constant, χ D , in the PDO 3 2- anion has been measured in solution by NMR spin-lattice (T 1 ) relaxation time measurements and it has been calculated via ab initio methods. The experimental value of 94.7 ± 0.5 kHz is in excellent agreement with the ab initio value of 95.0 kHz. The activation energy for the ion reorientation is 2.23 ± 0.01 kJ mol -1
Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber
International Nuclear Information System (INIS)
Jing, Wei; Roberts, William L.; Fang, Tiegang
2015-01-01
This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O 2 concentrations were used, spanning 10–21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH ∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH ∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH ∗ with the increase of ambient temperature and O 2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O 2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O 2 concentration conditions by
International Nuclear Information System (INIS)
Broeders, I.; Krieg, B.
1977-01-01
The code MIGROS-3 was developed from MIGROS-2. The main advantage of MIGROS-3 is its compatibility with the new conventions of the latest version of the Karlsruhe nuclear data library, KEDAK-3. Moreover, to some extent refined physical models were used and numerical methods were improved. MIGROS-3 allows the calculation of microscopic group cross sections of the ABBN type from isotopic neutron data given in KEDAK-format. All group constants, necessary for diffusion-, consistent P 1 - and Ssub(N)-calculations can be generated. Anisotropy of elastic scattering can be taken into account up to P 5 . A description of the code and the underlying theory is given. The input and output description, a sample problem and the program lists are provided. (orig.) [de
Variational RRKM calculation of thermal rate constant for C–H bond fission reaction of nitro methane
Directory of Open Access Journals (Sweden)
Afshin Taghva Manesh
2017-02-01
Full Text Available The present work provides quantitative results for the rate constants of unimolecular C–H bond fission reactions in the nitro methane at elevated temperatures up to 2000 K. In fact, there are three different hydrogen atoms in the nitro methane. The potential energy surface for each C–H bond fission reaction of nitro methane was investigated by ab initio calculations. The geometry and vibrational frequencies of the species involved in this process were optimized at the MP2 level of theory, using the cc-pvdz basis set. Since C–H bond fission channel is a barrierless reaction, we have used variational RRKM theory to predict rate coefficients. By means of calculated rate coefficients at different temperatures, the Arrhenius expression of the channel over the temperature range of 100–2000 K is k(T = 5.9E19∗exp(−56274.6/T.
CAL3JHH: a Java program to calculate the vicinal coupling constants (3J H,H) of organic molecules.
Aguirre-Valderrama, Alonso; Dobado, José A
2008-12-01
Here, we present a free web-accessible application, developed in the JAVA programming language for the calculation of vicinal coupling constant (3J(H,H)) of organic molecules with the H-Csp3-Csp3-H fragment. This JAVA applet is oriented to assist chemists in structural and conformational analyses, allowing the user to calculate the averaged 3J(H,H) values among conformers, according to its Boltzmann populations. Thus, the CAL3JHH program uses the Haasnoot-Leeuw-Altona equation, and, by reading the molecule geometry from a protein data bank (PDB) file format or from multiple pdb files, automatically detects all the coupled hydrogens, evaluating the data needed for this equation. Moreover, a "Graphical viewer" menu allows the display of the results on the 3D molecule structure, as well as the plotting of the Newman projection for the couplings.
Elastic constants of the hard disc system in the self-consistent free volume approximation
International Nuclear Information System (INIS)
Wojciechowski, K.W.
1990-09-01
Elastic moduli of the two dimensional hard disc crystal are determined exactly within the Kirkwood self-consistent free volume approximation and compared with the Monte Carlo simulation results. (author). 22 refs, 1 fig., 1 tab
Valiev, R R; Cherepanov, V N; Baryshnikov, G V; Sundholm, D
2018-02-28
A method for calculating the rate constants for internal-conversion (k IC ) and intersystem-crossing (k ISC ) processes within the adiabatic and Franck-Condon (FC) approximations is proposed. The applicability of the method is demonstrated by calculation of k IC and k ISC for a set of organic and organometallic compounds with experimentally known spectroscopic properties. The studied molecules were pyrromethene-567 dye, psoralene, hetero[8]circulenes, free-base porphyrin, naphthalene, and larger polyacenes. We also studied fac-Alq 3 and fac-Ir(ppy) 3 , which are important molecules in organic light emitting diodes (OLEDs). The excitation energies were calculated at the multi-configuration quasi-degenerate second-order perturbation theory (XMC-QDPT2) level, which is found to yield excitation energies in good agreement with experimental data. Spin-orbit coupling matrix elements, non-adiabatic coupling matrix elements, Huang-Rhys factors, and vibrational energies were calculated at the time-dependent density functional theory (TDDFT) and complete active space self-consistent field (CASSCF) levels. The computed fluorescence quantum yields for the pyrromethene-567 dye, psoralene, hetero[8]circulenes, fac-Alq 3 and fac-Ir(ppy) 3 agree well with experimental data, whereas for the free-base porphyrin, naphthalene, and the polyacenes, the obtained quantum yields significantly differ from the experimental values, because the FC and adiabatic approximations are not accurate for these molecules.
Hale, Lucas M.; Trautt, Zachary T.; Becker, Chandler A.
2018-07-01
Atomistic simulations using classical interatomic potentials are powerful investigative tools linking atomic structures to dynamic properties and behaviors. It is well known that different interatomic potentials produce different results, thus making it necessary to characterize potentials based on how they predict basic properties. Doing so makes it possible to compare existing interatomic models in order to select those best suited for specific use cases, and to identify any limitations of the models that may lead to unrealistic responses. While the methods for obtaining many of these properties are often thought of as simple calculations, there are many underlying aspects that can lead to variability in the reported property values. For instance, multiple methods may exist for computing the same property and values may be sensitive to certain simulation parameters. Here, we introduce a new high-throughput computational framework that encodes various simulation methodologies as Python calculation scripts. Three distinct methods for evaluating the lattice and elastic constants of bulk crystal structures are implemented and used to evaluate the properties across 120 interatomic potentials, 18 crystal prototypes, and all possible combinations of unique lattice site and elemental model pairings. Analysis of the results reveals which potentials and crystal prototypes are sensitive to the calculation methods and parameters, and it assists with the verification of potentials, methods, and molecular dynamics software. The results, calculation scripts, and computational infrastructure are self-contained and openly available to support researchers in performing meaningful simulations.
International Nuclear Information System (INIS)
Mariën, A.; Mokni, N.; Valcke, E.; Olivella, S.; Smets, S.; Li, X.
2013-01-01
Highlights: ► The water uptake by Eurobitum is studied to judge the safety of geological disposal. ► High pressures of up to 20 MPa are measured in constant volume water uptake tests. ► The morphology of leached Eurobitum samples is studied with μCT and ESEM. ► The observations are reproduced by an existing CHM formulation for Eurobitum. - Abstract: The chemo-hydro-mechanical (CHM) interaction between swelling Eurobitum radioactive bituminized waste (BW) and Boom Clay is investigated to assess the feasibility of geological disposal for the long-term management of this waste. These so-called compatibility studies include laboratory water uptake tests at Belgian Nuclear Research Center SCK-CEN, and the development of a coupled CHM formulation for Eurobitum by the International Center for Numerical Methods and Engineering (CIMNE, Polytechnical University of Cataluña, Spain). In the water uptake tests, the osmosis-induced swelling, pressure increase and NaNO 3 leaching of small cylindrical BW samples (diameter 38 mm, height 10 mm) is studied under constant total stress conditions and nearly constant volume conditions; the actual geological disposal conditions should be intermediate between these extremes. Two nearly constant volume tests were stopped after 1036 and 1555 days to characterize the morphology of the hydrated BW samples and to visualize the hydrated part with microfocus X-ray Computer Tomography (μCT) and Environmental Scanning Electron Microscopy (ESEM). In parallel, a coupled CHM formulation is developed that describes chemically and hydraulically coupled flow processes in porous materials with salt crystals, and that incorporates a porosity dependent membrane efficiency, permeability and diffusivity. When Eurobitum BW is hydrated in (nearly) constant volume conditions, the osmosis-induced water uptake results in an increasing pressure to values that can be (in theory) as high as 42.8 MPa, being the osmotic pressure of a saturated NaNO 3
International Nuclear Information System (INIS)
Khan, A.A.; Goeckeler, M.; Haegler, P.
2006-03-01
We present data for the axial coupling constant g A of the nucleon obtained in lattice QCD with two degenerate flavours of dynamical non-perturbatively improved Wilson quarks. The renormalisation is also performed non-perturbatively. For the analysis we give a chiral extrapolation formula for g A based on the small scale expansion scheme of chiral effective field theory for two degenerate quark flavours. Applying this formalism in a finite volume we derive a formula that allows us to extrapolate our data simultaneously to the infinite volume and to the chiral limit. Using the additional lattice data in finite volume we are able to determine the axial coupling of the nucleon in the chiral limit without imposing the known value at the physical point. (Orig.)
Energy Technology Data Exchange (ETDEWEB)
Khan, A.A.; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Haegler, P. [Technische Univ. Muenchen (DE). Physik-Department, Theoretische Physik] (and others)
2006-03-15
We present data for the axial coupling constant g{sub A} of the nucleon obtained in lattice QCD with two degenerate flavours of dynamical non-perturbatively improved Wilson quarks. The renormalisation is also performed non-perturbatively. For the analysis we give a chiral extrapolation formula for g{sub A} based on the small scale expansion scheme of chiral effective field theory for two degenerate quark flavours. Applying this formalism in a finite volume we derive a formula that allows us to extrapolate our data simultaneously to the infinite volume and to the chiral limit. Using the additional lattice data in finite volume we are able to determine the axial coupling of the nucleon in the chiral limit without imposing the known value at the physical point. (Orig.)
Bénech, Bruno; Ezcurra, Agustin; Lothon, Marie; Saïd, Frédérique; Campistron, Bernard; Lohou, Fabienne; Durand, Pierre
ESCOMPTE programme aims at studying the emissions of primary pollutants in industrial and urban areas, their transport, diffusion and transformation in the atmosphere. This experiment, carried out in southeast France, can be used to validate and to improve meteorological and chemical mesoscale models. One major goal of this experiment was to follow the pollutant plumes, and to investigate its thermodynamic and physico-chemical time evolution. This was realized by means of constant volume balloons, located by global position satellite (GPS) and equipped with thermodynamic and ozone sensors, flying at constant density levels. During the two ESCOMPTE campaigns that took place in June and July 2000 and 2001, 40 balloons were launched, 17 of them equipped with ozone sensors during the day from 0800 to 1800 UTC. Balloons' altitudes flight levels ranged between 400 and 1200 m altitude with Mistral (northerly synoptic flow) and Sea Breeze (southerly breeze) conditions. The atmospheric boundary layer (ABL) topography of the experimental domain is complex and varies strongly from day to day. Its depth presents a large gradient from the sea coast to the north part of the ESCOMPTE domain, and also more complex variability within the domain. The balloons' trajectories describe the evolution of the pollutant plume emitted from the industrial area of Fos-Berre or from the Marseille urban area. Constant volume balloons give a good description of the trajectories of these two plumes. The balloons, which fly at an isopicnic level, cross different atmospheric layers chiefly depending on the ABL height in relation with the constant volume balloons flight level. Thus, each balloon flight is decomposed into different segments that correspond to the same atmospheric layer. In each segment, the ozone content variation is analyzed in relation to other thermodynamical parameters measured by the balloon and mainly to the vapor mixing ratio content. During ESCOMPTE campaign, the mean linear
40 CFR 80.596 - How is a refinery motor vehicle diesel fuel volume baseline calculated?
2010-07-01
... 40 Protection of Environment 16 2010-07-01 2010-07-01 false How is a refinery motor vehicle diesel... Requirements § 80.596 How is a refinery motor vehicle diesel fuel volume baseline calculated? (a) For purposes of this subpart, a refinery's motor vehicle diesel fuel volume baseline is calculated using the...
Spectroscopic Constants for Selected Homonuclear Diatomic Molecules. Volume 2. K through Z
1976-02-16
Radiative Transfer 8, 1431-6 Theory, L. Szasz and G. McGinn, "Atomic and Molecular Calculations With the Pseudopotential Method. III. The Theory...Configuration Interaction. " J. Chem. Phy». 48, 434-9 (68. 48) L. Szasz and G. McGinn, "Atomic and Molecular Calculations With the...Singh and D. K. Rai. Indian J. Pure Appl. Phys. 2.475-8 (66. 38) L. Szasz and G. McGinn, "Atomic and Molecular Calculations With the
Strong enhancement of piezoelectric constants in ScxAl1−xN: First-principles calculations
Directory of Open Access Journals (Sweden)
Hiroyoshi Momida
2016-06-01
Full Text Available We theoretically investigate the piezoelectricity of ScxAl1−xN in the entire range of x by first-principles calculations. We find that the piezoelectric constants of wurtzite-type ScxAl1−xN significantly enhance as x increases from 0 to 0.75. However, the energy stability analyses between structure phases show that the cubic-type phases become more stable than the wurtzite-type phases at x of approximately 0.5 and higher, interfering with the ability of wurtzite-type ScxAl1−xN to realize the maximum piezoelectricity. Moreover, our study on element combination dependences on piezoelectricity in A0.5B0.5N (A = Sc, Y, La and B = Al, Ga, In indicates that Sc, Y, and La have the strongest effect on the enhancement of piezoelectric constants in AlN, GaN, and InN, respectively.
Directory of Open Access Journals (Sweden)
T. William Bentley
2015-05-01
Full Text Available Hydrolyses of acid derivatives (e.g., carboxylic acid chlorides and fluorides, fluoro- and chloroformates, sulfonyl chlorides, phosphorochloridates, anhydrides exhibit pseudo-first order kinetics. Reaction mechanisms vary from those involving a cationic intermediate (SN1 to concerted SN2 processes, and further to third order reactions, in which one solvent molecule acts as the attacking nucleophile and a second molecule acts as a general base catalyst. A unified framework is discussed, in which there are two reaction channels—an SN1-SN2 spectrum and an SN2-SN3 spectrum. Third order rate constants (k3 are calculated for solvolytic reactions in a wide range of compositions of acetone-water mixtures, and are shown to be either approximately constant or correlated with the Grunwald-Winstein Y parameter. These data and kinetic solvent isotope effects, provide the experimental evidence for the SN2-SN3 spectrum (e.g., for chloro- and fluoroformates, chloroacetyl chloride, p-nitrobenzoyl p-toluenesulfonate, sulfonyl chlorides. Deviations from linearity lead to U- or V-shaped plots, which assist in the identification of the point at which the reaction channel changes from SN2-SN3 to SN1-SN2 (e.g., for benzoyl chloride.
Tomaschitz, R
1989-01-01
We consider geodesic motion on three-dimensional Riemannian manifolds of constant negative curvature, topologically equivalent to S x ]0,1[, S a compact surface of genus two. To those trajectories which are bounded and recurrent in both directions of the time evolution a fractal limit set is associated whose Hausdorff dimension is intimately connected with the quantum mechanical energy ground state, determined by the Schrodinger operator on the manifold. We give a rather detailed and pictorial description of the hyperbolic spaces we have in mind, discuss various aspects of classical and quantum mechanical motion on them as far as they are needed to establish the connection between energy ground state and Hausdorff dimension and give finally some examples of ground state calculations in terms of Hausdorff dimensions of limit sets of classical trajectories.
Zhekova, Hristina R; Seth, Michael; Ziegler, Tom
2011-11-14
We have recently developed a methodology for the calculation of exchange coupling constants J in weakly interacting polynuclear metal clusters. The method is based on unrestricted and restricted second order spin-flip constricted variational density functional theory (SF-CV(2)-DFT) and is here applied to eight binuclear copper systems. Comparison of the SF-CV(2)-DFT results with experiment and with results obtained from other DFT and wave function based methods has been made. Restricted SF-CV(2)-DFT with the BH&HLYP functional yields consistently J values in excellent agreement with experiment. The results acquired from this scheme are comparable in quality to those obtained by accurate multi-reference wave function methodologies such as difference dedicated configuration interaction and the complete active space with second-order perturbation theory. © 2011 American Institute of Physics
International Nuclear Information System (INIS)
Tomaschitz, R.
1989-01-01
We consider geodesic motion on three-dimensional Riemannian manifolds of constant negative curvature, topologically equivalent to S x ]0,1[, S a compact surface of genus two. To those trajectories which are recurrent in both directions of the time evolution t → +∞, t → -∞ a fractal limit set is associated whose Hausdorff dimension is intimately connected with the quantum mechanical energy ground state, determined by the Schroedinger operator on the manifold. We give a rather detailed and pictorial description of the hyperbolic spaces we have in mind, discuss various aspects of classical and quantum mechanical motion on them as far as they are needed to establish the connection between energy ground state and Hausdorff dimension and give finally some examples of ground state calculations in terms of Hausdorff dimensions of limit sets of classical trajectories. (orig.)
Bennett, Ed; Ki Hong, Deog; Lee, Jong-Wan; David Lin, C.-J.; Lucini, Biagio; Piai, Maurizio; Vadacchino, Davide
2018-03-01
As a first step towards a quantitative understanding of the SU(4)/Sp(4) composite Higgs model through lattice calculations, we discuss the low energy effective field theory resulting from the SU(4) → Sp(4) global symmetry breaking pattern. We then consider an Sp(4) gauge theory with two Dirac fermion flavours in the fundamental representation on a lattice, which provides a concrete example of the microscopic realisation of the SU(4)/Sp(4) composite Higgs model. For this system, we outline a programme of numerical simulations aiming at the determination of the low-energy constants of the effective field theory and we test the method on the quenched theory. We also report early results from dynamical simulations, focussing on the phase structure of the lattice theory and a calculation of the lowest-lying meson spectrum at coarse lattice spacing. Combined contributions of B. Lucini (e-mail: b.lucini@swansea.ac.uk) and J.-W. Lee (e-mail: wlee823@pusan.ac.kr).
Construction and Start-up of a Large-Volume Thermostat for Dielectric-Constant Gas Thermometry
Merlone, A.; Moro, F.; Zandt, T.; Gaiser, C.; Fellmuth, B.
2010-07-01
A liquid-bath thermostat with a volume of about 800 L was designed to provide a suitable thermal environment for a dielectric-constant gas thermometer (DCGT) in the range from the triple point of mercury to the melting point of gallium. In the article, results obtained with the unique, huge thermostat without the DCGT measuring chamber are reported to demonstrate the capability of controlling the temperature of very large systems at a metrological level. First tests showed that the bath together with its temperature controller provide a temperature variation of less than ±0.5mK peak-to-peak. This temperature instability could be maintained over a period of several days. In the central working volume (diameter—500mm, height—650mm), in which the vacuum chamber containing the measuring system of the DCGT will be placed later, the temperature inhomogeneity has been demonstrated to be also well below 1mK.
Wijdeven, S.M.J.; Vaessen, O.H.B.; Hees, van A.F.M.; Olsthoorn, A.F.M.
2005-01-01
Dead wood is recognized as one of the key indicators for sustainable forest management and biodiversity. Accurate assessments of dead wood volume are thus necessary. In this study New volume models were designed based on actual volume measurements of coarse woody debris. The New generic model
Calculated Specific Volumes and Magnetic Moments of the 3d Transition Metal Monoxides
DEFF Research Database (Denmark)
Skriver, Hans Lomholt; Andersen, O. K.; Johansson, B.
1980-01-01
We have performed self-consistent, spin-polarized band structure calculations as a function of the lattice spacing for the 3d metal monoxides in order to obtain the equilibrium lattice constants. The calculated binding from the 3d electrons and the occurrence of antiferromagnetism account...
International Nuclear Information System (INIS)
Trkov, A.; Budnar, M.; Copic, M.; Perdan, A.; Ravnik, M.
1982-01-01
Multigroup constants for 1-H-1, 92-U-235, and 92-U-238 have been calculated. Averaged cross-sections and other constants have been prepared in the WIMS 69-group format. Comparison has been made between group constants obtained with several evaluated libraries (KEDAK-3 1975, 1979, ENDF/B-4, ENDF/B-5) and the WIMS-D library. Observed differences are most pronounced in the resonance and fast region. From test runs on fuel cell with the WIMS program it can be deduced that these differences affect the fewgroup constants significantly. (author)
Mahmood, I
1999-08-01
Pharmacokinetic parameters (clearance, CL, volume of distribution in the central compartment, VdC, and elimination half-life, t1/2beta) predicted by an empirical allometric approach have been compared with parameters predicted from plasma concentrations calculated by use of the pharmacokinetic constants A, B, alpha and beta, where A and B are the intercepts on the Y axis of the plot of plasma concentration against time and alpha and beta are the rate constants, both pairs of constants being for the distribution and elimination phases, respectively. The pharmacokinetic parameters of cefpiramide, actisomide, troglitazone, procaterol, moxalactam and ciprofloxacin were scaled from animal data obtained from the literature. Three methods were used to generate plots for the prediction of clearance in man: dependence of clearance on body weight (simple allometric equation); dependence of the product of clearance and maximum life-span potential (MLP) on body weight; and dependence of the product of clearance and brain weight on body weight. Plasma concentrations of the drugs were predicted in man by use of A, B, alpha and beta obtained from animal data. The predicted plasma concentrations were then used to calculate CL, VdC and t1/2beta. The pharmacokinetic parameters predicted by use of both approaches were compared with measured values. The results indicate that simple allometry did not predict clearance satisfactorily for actisomide, troglitazone, procaterol and ciprofloxacin. Use of MLP or the product of clearance and brain weight improved the prediction of clearance for these four drugs. Except for troglitazone, VdC and t1/2beta predicted for man by use of the allometric approach were comparable with measured values for the drugs studied. CL, VdC and t1/2beta predicted by use of pharmacokinetic constants were comparable with values predicted by simple allometry. Thus, if simple allometry failed to predict clearance of a drug, so did the pharmacokinetic constant
International Nuclear Information System (INIS)
Chan, T.; Cook, N.G.W.
1979-12-01
Thermally induced displacements and stresses have been calculated by finite element analysis to guide the design, operation, and data interpretation of the in situ heating experiments in a granite formation at Stripa, Sweden. There are two full-scale tests with electrical heater canisters comparable in size and power to those envisaged for reprocessed high level waste canisters and a time-scaled test. To provide a simple theoretical basis for data analysis, linear thermoelasticity was assumed. Constant (temperature-independent) thermal and mechanical rock properties were used in the calculations. These properties were determined by conventional laboratory testing on small intact core specimens recovered from the Stripa test site. Two-dimensional axisymmetric models were used for the full-scale experiments, and three-dimensional models for the time-scaled experiment. Highest compressive axial and tangential stresses are expected at the wall of the heater borehole. For the 3.6 kW full-scale heated experiment, maximum compressive tangential stress was predicted to be below the unconfined compressive strength of Stripa granite, while for the 5 kW experiment, the maximum was approximately equal to the compressive strength before the concentric ring of eight 1 kW peripheral heaters was activated, but would exceed that soon afterwards. Three zones of tensile thermomechanical stresses will occur in each full-scale experiment. Maximum vertical displacements range from a fraction of a millimeter over most of the instrumented area of the time-scaled experiment to a few millimeters in the higher-power full-scale experiment. Radial displacements are typically half or less than vertical displacements. The predicted thermomechanical displacements and stresses have been stored in an on-site computer to facilitate instant graphic comparison with field data as the latter are collected
International Nuclear Information System (INIS)
Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia
2015-01-01
Highlights: • To examine surface hydroxyl functional groups of the calcined diatomite by TGA-DSC, FTIR, and XPS. • To calculate the optimized log K 1 , log K 2 and log C values and the surface species distribution of each surface reactive site using ProtoFit and PHREEQC, respectively. - Abstract: The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation–deprotonation behavior was determined by continuous acid–base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m 2 /g and large numbers of surface hydroxyl functional groups (i.e. ≡Si-OH, ≡Fe-OH, and ≡Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K 1 , log K 2 ) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation–deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent
Energy Technology Data Exchange (ETDEWEB)
Ma, Shu-Cui [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun 130022 (China); Wang, Zhi-Gang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zhang, Ji-Lin, E-mail: zjl@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Sun, De-Hui [Changchun Institute Technology, Changchun 130012 (China); Liu, Gui-Xia, E-mail: liuguixia22@163.com [Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province, Changchun University of Science and Technology, Changchun 130022 (China)
2015-02-01
Highlights: • To examine surface hydroxyl functional groups of the calcined diatomite by TGA-DSC, FTIR, and XPS. • To calculate the optimized log K{sub 1}, log K{sub 2} and log C values and the surface species distribution of each surface reactive site using ProtoFit and PHREEQC, respectively. - Abstract: The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation–deprotonation behavior was determined by continuous acid–base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m{sup 2}/g and large numbers of surface hydroxyl functional groups (i.e. ≡Si-OH, ≡Fe-OH, and ≡Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K{sub 1}, log K{sub 2}) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation–deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.
Diameter structure modeling and the calculation of plantation volume of black poplar clones
Directory of Open Access Journals (Sweden)
Andrašev Siniša
2004-01-01
Full Text Available A method of diameter structure modeling was applied in the calculation of plantation (stand volume of two black poplar clones in the section Aigeiros (Duby: 618 (Lux and S1-8. Diameter structure modeling by Weibull function makes it possible to calculate the plantation volume by volume line. Based on the comparison of the proposed method with the existing methods, the obtained error of plantation volume was less than 2%. Diameter structure modeling and the calculation of plantation volume by diameter structure model, by the regularity of diameter distribution, enables a better analysis of the production level and assortment structure and it can be used in the construction of yield and increment tables.
Ma, Shu-Cui; Wang, Zhi-Gang; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia
2015-02-01
The surface properties of the diatomite were investigated using nitrogen adsorption/deadsorption isotherms, TG-DSC, FTIR, and XPS, and surface protonation-deprotonation behavior was determined by continuous acid-base potentiometric titration technique. The diatomite sample with porous honeycomb structure has a BET specific surface area of 10.21 m2/g and large numbers of surface hydroxyl functional groups (i.e. tbnd Si-OH, tbnd Fe-OH, and tbnd Al-OH). These surface hydroxyls can be protonated or deprotonated depending on the pH of the suspension. The experimental potentiometric data in two different ionic strength solutions (0.1 and 0.05 mol/L NaCl) were fitted using ProtoFit GUI V2.1 program by applying diffuse double layer model (DLM) with three amphoteric sites and minimizing the sum of squares between a dataset derivative function and a model derivative function. The optimized surface parameters (i.e. surface dissociation constants (log K1, log K2) and surface site concentrations (log C)) of the sample were obtained. Based on the optimized surface parameters, the surface species distribution was calculated using Program-free PHREEQC 3.1.2. Thus, this work reveals considerable new information about surface protonation-deprotonation processes and surface adsorptive behaviors of the diatomite, which helps us to effectively use the cheap and cheerful diatomite clay adsorbent.
International Nuclear Information System (INIS)
Mu, Tiancheng; Liu, Zhimin; Han, Buxing.; Li, Zhonghao; Zhang, Jianling; Zhang, Xiaogang
2003-01-01
The phase behavior, density, and constant-volume molar heat capacity (C v,m ) of ethane + n-pentane binary mixtures have been measured in the supercritical region and subcritical region at T=309.45 K. In addition, the isothermal compressibility (κ T ) has been calculated using the density data determined. For a mixed fluid with a composition close to the critical composition, C v,m and κ T increase sharply as the pressure approaches the critical point (CP), the dew point (DP), or the bubble point (BP). However, C v,m is not sensitive to pressure in the entire pressure range if the composition of the mixed fluid is far from the critical composition. To tune the properties of the binary mixtures effectively by pressure, both the composition and the pressure should be close to the critical point of the mixture. The intermolecular interactions in the mixture are also discussed on the basis of the experimental results
40 CFR 80.599 - How do I calculate volume balances for designation purposes?
2010-07-01
... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Motor Vehicle Diesel Fuel... June 30, 2013. July 1, 2013 May 31, 2014. (2) [Reserved] (b) Volume balance for motor vehicle diesel fuel. (1) A facility's motor vehicle diesel fuel volume balance is calculated as follows: MVB = MVI−MVO...
Directory of Open Access Journals (Sweden)
Hongzhan Xie
2015-06-01
Full Text Available The objective of this study was to investigate the macroscopic spray characteristics of different 0%–100% blends of biodiesel derived from drainage oil and diesel (BD0, BD20, BD50, BD80, BD100, such as spray tip penetration, average tip velocity at penetration, spray angle, average spray angle, spray evolution process, spray area and spray volume under different injection pressures (60, 70, 80, 90, 100 MPa and ambient pressures (0.1, 0.3, 0.5, 0.7, 0.9 MPa using a common rail system equipped with a constant volume chamber. The characteristic data was extracted from spray images grabbed by a high speed visualization system. The results showed that the ambient pressure and injection pressure had significant effects on the spray characteristics. As the ambient pressure increased, the spray angle increased, while the spray tip penetration and the peak of average tip velocity decreased. As the injection pressure increased, the spray tip penetration, spray angle, spray area and spray volume increased. The increasing blend ratio of biodiesel brought about a shorter spray tip penetration and a smaller spray angle compared with those of diesel. This is due to the comparatively higher viscosity and surface tension of biodiesel, which enhanced the friction effect between fuel and the injector nozzle surface and inhibited the breakup of the liquid jet.
Ultrasound automated volume calculation in reproduction and in pregnancy.
Ata, Baris; Tulandi, Togas
2011-06-01
To review studies assessing the application of ultrasound automated volume calculation in reproductive medicine. We performed a literature search using the keywords "SonoAVC, sonography-based automated volume calculation, automated ultrasound, 3D ultrasound, antral follicle, follicle volume, follicle monitoring, follicle tracking, in vitro fertilization, controlled ovarian hyperstimulation, embryo volume, embryonic volume, gestational sac, and fetal volume" and conducted the search in PubMed, Medline, EMBASE, and the Cochrane Database of Systematic Reviews. Reference lists of identified reports were manually searched for other relevant publications. Automated volume measurements are in very good agreement with actual volumes of the assessed structures or with other validated measurement methods. The technique seems to provide reliable and highly reproducible results under a variety of conditions. Automated measurements take less time than manual measurements. Ultrasound automated volume calculation is a promising new technology which is already used in daily practice especially for assisted reproduction. Improvements to the technology will undoubtedly render it more effective and increase its use. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Few-group constants for the calculation of ksub(eff) and Δ(1/ksub(eff)) of fast breeder reactors
International Nuclear Information System (INIS)
Svarny, J.
1978-01-01
A theoretical and numerical analysis is presented of the linear and bilinear weighting of group constants. Special attention is paid to error accumulation in the few-group calculations of reactivity (ksub(eff)) and its first order perturbations caused by inaccuracies in weighting functions. Some theoretical conclusions are supported by calculations of the BN-600 fast breeder reactor. (author)
Energy Technology Data Exchange (ETDEWEB)
Nyawere, P.W.O., E-mail: otienop98@yahoo.ca [Computational Materials Science Group, Department of Physics, University of Eldoret, P.O. Box 1125-30100 Eldoret (Kenya); Department of Computing, Kabarak University, P.O. - Private Bag - 20157 Kabarak (Kenya); The Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Makau, N.W., E-mail: wanimak@yahoo.com [Computational Materials Science Group, Department of Physics, University of Eldoret, P.O. Box 1125-30100 Eldoret (Kenya); Amolo, G.O., E-mail: georgeamolo862@gmail.com [Computational Materials Science Group, Department of Physics, University of Eldoret, P.O. Box 1125-30100 Eldoret (Kenya)
2014-02-01
All the elastic constants of cubic, orthorhombic and hexagonal phases of BaF{sub 2} have been calculated using first principles methods. We have employed density-functional theory within generalized gradient approximation (GGA) using a plane-wave pseudopotentials method and a plane-wave basis set. The calculated elastic constant values for a cubic phase compare well with recent theoretical and experimental calculations. The bulk modulus derived from the elastic constant calculations of orthorhombic phase of BaF{sub 2} is 94.5 GPa and those of hexagonal phase is 161 GPa. These values are in good agreement with experimental data available. Stability of these phases of BaF{sub 2} is also estimated in different crystallographic directions.
A Memorandum Report: Physical Constants of MCE
2016-08-01
the density and surface tension. In effect, this constant is a corrected molar volume = P = MS / = S / where P = Parachor M = molar volume ...3 3. Vapor Pressure of MCE Calculated from the Experimental Data by Method of Least Squares...values were obtained by averaging the determinations for each sample separately, and then averaging those values. **No average was calculated due to
Directory of Open Access Journals (Sweden)
Chao Hu
2015-04-01
Full Text Available Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positioning of excavation projects using traditional instruments is inefficient and may cause error. To improve the efficiency and precision of calculation and assessment, three-dimensional laser scanning technology was used for slope excavation quality assessment. An efficient data acquisition, processing, and management workflow was presented in this study. Based on the quality control indices, including the average gradient, slope toe elevation, and overbreak and underbreak, cross-sectional quality assessment and holistic quality assessment methods were proposed to assess the slope excavation quality with laser-scanned data. An algorithm was also presented to calculate the excavated volume with laser-scanned data. A field application and a laboratory experiment were carried out to verify the feasibility of these methods for excavation quality assessment and excavated volume calculation. The results show that the quality assessment indices can be obtained rapidly and accurately with design parameters and scanned data, and the results of holistic quality assessment are consistent with those of cross-sectional quality assessment. In addition, the time consumption in excavation quality assessment with the laser scanning technology can be reduced by 70%–90%, as compared with the traditional method. The excavated volume calculated with the scanned data only slightly differs from measured data, demonstrating the applicability of the excavated volume calculation method presented in this study.
Yu, Yi-Lin; Lee, Meei-Shyuan; Juan, Chun-Jung; Hueng, Dueng-Yuan
2013-08-01
The ABC/2 equation is commonly applied to measure the volume of intracranial hematoma. However, the precision of ABC/2 equation in estimating the tumor volume of acoustic neuromas is less addressed. The study is to evaluate the accuracy of the ABC/2 formula by comparing with planimetry method for estimating the tumor volumes. Thirty-two patients diagnosed with acoustic neuroma received contrast-enhanced magnetic resonance imaging of brain were recruited. The volume was calculated by the ABC/2 equation and planimetry method (defined as exact volume) at the same time. The 32 patients were divided into three groups by tumor volume to avoid volume-dependent overestimation (6 ml). The tumor volume by ABC/2 method was highly correlated to that calculated by planimetry method using linear regression analysis (R2=0.985). Pearson correlation coefficient (r=0.993, pABC/2 formula is an easy method in estimating the tumor volume of acoustic neuromas that is not inferior to planimetry method. Copyright © 2013 Elsevier B.V. All rights reserved.
Moriyoshi, Yasuo; Kobayashi, Shigemi; Enomoto, Yoshiteru
Knock phenomenon in SI engines is regarded as an auto-ignition of unburned end-gas, and it has been widely examined by using rapid compression machines (RCM), shock-tubes or test engines. Recent researches point out the importance of the low temperature chemical reaction and the negative temperature coefficient (NTC). To investigate the effects, analyses of instantaneous local gas temperature, flow visualization and gaseous pressure were conducted in this study. As measurements using real engines are too difficult to analyze, the authors aimed to make measurements using a constant volume vessel under knock conditions where propagating flame exists during the induction time of auto-ignition. Adopting the two-wire thermocouple method enabled us to measure the instantaneous local gas temperature until the moment when the flame front passes by. High-speed images inside the unburned region were also recorded simultaneously using an endoscope. As a result, it was found that when knock occurs, the auto-ignition initiation time seems slightly early compared to the results without knock. This causes a higher volume ratio of unburned mixture and existence of many hot spots and stochastically leads to an initiation of knock.
Institute of Scientific and Technical Information of China (English)
Gholam Hossein Bordbar; Hajar Bahri; Fatemeh Kayanikhoo
2012-01-01
We have calculated the structural properties of a strange quark star with a static model in the presence of a strong magnetic field.To this end,we use the MITbag model with a density dependent bag constant.To parameterize the density dependence of the bag constant,we have used our results for the lowest order constrained variational calculation of the asymmetric nuclear matter.By calculating the equation of state of strange quark matter,we have shown that the pressure of this system increases by increasing both density and magnetic field.Finally,we have investigated the effect of density dependence of the bag constant on the structural properties of a strange quark star.
International Nuclear Information System (INIS)
Hu Lin; Cui Wei; Shi Hanwen; Tian Yingping; Wang Weigang; Feng Yanguang; Huang Xueyan; Liu Zhisheng
2003-01-01
Objective: To compare the relative accuracy of three methods measuring left ventricular volume by X-ray ventriculography: single plane area-length method, biplane area-length method, and single-plane Simpson's method. Methods: Left ventricular casts were obtained within 24 hours after death from 12 persons who died from non-cardiac causes. The true left ventricular cast volume was measured by water displacement. The calculated volume of the casts was obtained with 3 angiographic methods, i.e., single-plane area-length method, biplane area-length method, and single-plane Simpson's method. Results: The actual average volume of left ventricular casts was (61.17±26.49) ml. The left ventricular volume was averagely (97.50±35.56) ml with single plane area-length method, (90.51±36.33) ml with biplane area-length method, and (65.00± 23.63) ml with single-plane Simpson's method. The left ventricular volumes calculated with single-plane and biplane area-length method were significantly larger than that the actual volumes (P 0.05). The left ventricular volumes calculated with single-plane and biplane area-length method were significantly larger than those calculated with single-plane Simpson's method (P 0.05). The over-estimation of left ventricular volume by single plane area-length method (36.34±17.98) ml and biplane area-length method (29.34±15.59) ml was more obvious than that calculated by single-plane Simpson's method (3.83±8.48) ml. Linear regression analysis showed that there was close correlations between left ventricular volumes calculated with single plane area-length method, biplane area-length method, Simpson's method and the true volume (all r>0.98). Conclusion: Single-plane Simpson's method is more accurate than single plane area-length method and biplane area-length method for left ventricular volume measurement; however, both the single-plane and biplane area-length methods could be used in clinical practice, especially in those imaging modality
Energy Technology Data Exchange (ETDEWEB)
Takara, L.S.; Cunha, T.M.; Barbosa, P.; Rodrigues, M.K.; Oliveira, M.F.; Nery, L.E. [Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Disciplina de Pneumologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Neder, J.A. [Setor de Função Pulmonar e Fisiologia Clínica do Exercício, Disciplina de Pneumologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Division of Respiratory and Critical Care Medicine, Department of Medicine, Queen' s University, Kingston, ON (Canada)
2012-10-15
This study evaluated the dynamic behavior of total and compartmental chest wall volumes [(V{sub CW}) = rib cage (V{sub RC}) + abdomen (V{sub AB})] as measured breath-by-breath by optoelectronic plethysmography during constant-load exercise in patients with stable chronic obstructive pulmonary disease. Thirty males (GOLD stages II-III) underwent a cardiopulmonary exercise test to the limit of tolerance (Tlim) at 75% of peak work rate on an electronically braked cycle ergometer. Exercise-induced dynamic hyperinflation was considered to be present when end-expiratory (EE) V{sub CW} increased in relation to resting values. There was a noticeable heterogeneity in the patterns of V{sub CW} regulation as EEV{sub CW} increased non-linearly in 17/30 “hyperinflators” and decreased in 13/30 “non-hyperinflators” (P < 0.05). EEV{sub AB} decreased slightly in 8 of the “hyperinflators”, thereby reducing and slowing the rate of increase in end-inspiratory (EI) V{sub CW} (P < 0.05). In contrast, decreases in EEV{sub CW} in the “non-hyperinflators” were due to the combination of stable EEV{sub RC} with marked reductions in EEV{sub AB}. These patients showed lower EIV{sub CW} and end-exercise dyspnea scores but longer Tlim than their counterparts (P < 0.05). Dyspnea increased and Tlim decreased non-linearly with a faster rate of increase in EIV{sub CW} regardless of the presence or absence of dynamic hyperinflation (P < 0.001). However, no significant between-group differences were observed in metabolic, pulmonary gas exchange and cardiovascular responses to exercise. Chest wall volumes are continuously regulated during exercise in order to postpone (or even avoid) their migration to higher operating volumes in patients with COPD, a dynamic process that is strongly dependent on the behavior of the abdominal compartment.
International Nuclear Information System (INIS)
Meier, S.; Mildenberger, P.; Pitton, M.; Thelen, M.; Schenk, A.; Bourquain, H.
2004-01-01
Purpose: computed tomography has become the preferred method in detecting liver carcinomas. The introduction of spiral CT added volumetric assessment of intrahepatic tumors, which was unattainable in the clinical routine with incremental CT due to complex planimetric revisions and excessive computing time. In an ongoing clinical study, a new software tool was tested for the automatic detection of tumor volume and the time needed for this procedure. Materials and methods: we analyzed patients suffering from hepatocellular carcinoma (HCC). All patients underwent treatment with repeated transcatheter chemoembolization of the hepatic arteria. The volumes of the HCC lesions detected in CT were measured with the new software tool in HepaVison (MeVis, Germany). The results were compared with manual planimetric calculation of the volume performed by three independent radiologists. Results: our first results in 16 patients show a correlation between the automatically and the manually calculated volumes (up to a difference of 2 ml) of 96.8%. While the manual method of analyzing the volume of a lesion requires 2.5 minutes on average, the automatic method merely requires about 30 seconds of user interaction time. Conclusion: These preliminary results show a good correlation between automatic and manual calculations of the tumor volume. The new software tool requires less time for accurate determination of the tumor volume and can be applied in the daily clinical routine. (orig.) [de
Calculating regional tissue volume for hyperthermic isolated limb perfusion: Four methods compared.
Cecchin, D; Negri, A; Frigo, A C; Bui, F; Zucchetta, P; Bodanza, V; Gregianin, M; Campana, L G; Rossi, C R; Rastrelli, M
2016-12-01
Hyperthermic isolated limb perfusion (HILP) can be performed as an alternative to amputation for soft tissue sarcomas and melanomas of the extremities. Melphalan and tumor necrosis factor-alpha are used at a dosage that depends on the volume of the limb. Regional tissue volume is traditionally measured for the purposes of HILP using water displacement volumetry (WDV). Although this technique is considered the gold standard, it is time-consuming and complicated to implement, especially in obese and elderly patients. The aim of the present study was to compare the different methods described in the literature for calculating regional tissue volume in the HILP setting, and to validate an open source software. We reviewed the charts of 22 patients (11 males and 11 females) who had non-disseminated melanoma with in-transit metastases or sarcoma of the lower limb. We calculated the volume of the limb using four different methods: WDV, tape measurements and segmentation of computed tomography images using Osirix and Oncentra Masterplan softwares. The overall comparison provided a concordance correlation coefficient (CCC) of 0.92 for the calculations of whole limb volume. In particular, when Osirix was compared with Oncentra (validated for volume measures and used in radiotherapy), the concordance was near-perfect for the calculation of the whole limb volume (CCC = 0.99). With methods based on CT the user can choose a reliable plane for segmentation purposes. CT-based methods also provides the opportunity to separate the whole limb volume into defined tissue volumes (cortical bone, fat and water). Copyright © 2016 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Anneé Miranda Carracedo
2012-12-01
Full Text Available Objetivo: personalizar las constantes A, factor cirujano y profundidad de la cámara anterior para las fórmulas de cálculo de la lente intraocular en la cirugía de catarata en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" de mayo de 2007 a enero de 2011. Métodos: se realizó un estudio descriptivo retrospectivo donde se estudiaron las constantes A, factor cirujano y profundidad de la cámara anterior. También se evaluó la longitud axial preoperatoria por IOL Master, la mejor agudeza visual sin corrección, el componente esférico esperado, el componente esférico obtenido y los resultados refractivos. Resultados: las constantes optimizadas por interferometría de coherencia parcial son diferentes a las propuestas por los fabricantes de las lentes intraoculares. Estas constantes personalizadas para cada cirujano no mostraron diferencias significativas. Las constantes optimizadas según las longitudes axiales, tienen diferencias significativas en los 3 grupos de estudio. La diferencia entre la lente intraocular implantada y la propuesta con las nuevas constantes resultó menor de 1 D de error en 83,1 % de los pacientes. El 75,4 % quedó bien corregido en relación con la diferencia entre la refracción esperada y la obtenida. Conclusiones: las constantes optimizadas por interferometría de coherencia parcial resultan más elevadas que las propuestas por el fabricante. La optimización de estas en el cálculo de la lente permite, de acuerdo a las características individuales de cada ojo (longitud axial, usar la fórmula adecuada e incrementa la predictibilidad de los resultados refractivos posoperatorios.Objective: to personalize the A, surgeon factor and anterior chamber depth constants for intraocular lens calculation formulas in the cataract surgery at the “Ramón Pando Ferrer” Cuban Ophthalmological Institute from May 2007 to January 2011. Method: a retrospective and descriptive study was made to study the A constant
Gololobova, E. G.; Gorichev, I. G.; Lainer, Yu. A.; Skvortsova, I. V.
2011-05-01
A procedure was proposed for the calculation of the acid-base equilibrium constants at an alumina/electrolyte interface from experimental data on the adsorption of singly charged ions (Na+, Cl-) at various pH values. The calculated constants (p K {1/0}= 4.1, p K {2/0}= 11.9, p K {3/0}= 8.3, and p K {4/0}= 7.7) are shown to agree with the values obtained from an experimental pH dependence of the electrokinetic potential and the results of potentiometric titration of Al2O3 suspensions.
Energy Technology Data Exchange (ETDEWEB)
Santos, Rubens Souza dos [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Martinez, Aquilino Senra; Alvim, Antonio Carlos Marques [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear
2002-07-01
In this work is presented a methodology which focuses the distribution of neutron absorber rods in nuclear reactor power plants, for utilizing in space kinetic calculations, principally in the cluster ejection transients of control rods. A numerical model for macroscopic constant calculations based on the knowledge of the neutron flux without the control rods is proposed, as alternative to the analytical models, based on the hypothesis of the null current on the cell super boundaries. The proposed model in this work has itself showed adequate to deal with problems with strong space dependence, once that the model showed consistence in the global average built in the analytical model. (author)
Waste retrieval sluicing system campaign number 1 solids volume transferred calculation
International Nuclear Information System (INIS)
BAILEY, J.W.
1999-01-01
This calculation has been prepared to document the volume of sludge removed from tank 241-C-106 during Waste Retrieval Sluicing System (WRSS) Sluicing Campaign No.1. This calculation will be updated, if necessary, to incorporate new data. This calculation supports the declaration of completion of WRSS Campaign No.1 and, as such, is also the documentation for completion of Performance Agreement TWR 1.2.1 , C-106 Sluicing Performance Expectations. It documents the performance of all the appropriate tank 241-C-106 mass transfer verifications, evaluations, and appropriate adjustments discussed in HNF-SD-WM-PROC-021, Chapter 23, ''Process Engineering Calculations for Tank 241-C-106 Sluicing and Retrieval''
Waste retrieval sluicing system campaign number 1 solids volume transferred calculation
International Nuclear Information System (INIS)
BAILEY, J.W.
1999-01-01
This calculation has been prepared to document the volume of sludge removed from tank 241-C-106 during Waste Retrieval Sluicing System (WRSS) Sluicing Campaign No.1. This calculation will be updated, if necessary, to incorporate new data. This calculation supports the declaration of completion of WRSS Campaign No.1 and, as such, is also the documentation for completion of Performance Agreement TWR 1.2.1 C-106 Sluicing Performance Expectations. It documents the performance of all the appropriate tank 241-C-106 mass transfer verifications, evaluations, and appropriate adjustments discussed in HNF-SD-WM-PROC-021, Chapter 23, ''Process Engineering Calculations for Tank 241-C-106 Sluicing and Retrieval''
Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Demissie, Taye B; Ruud, Kenneth
2015-08-11
We present an implementation of the nuclear spin-rotation (SR) constants based on the relativistic four-component Dirac-Coulomb Hamiltonian. This formalism has been implemented in the framework of the Hartree-Fock and Kohn-Sham theory, allowing assessment of both pure and hybrid exchange-correlation functionals. In the density-functional theory (DFT) implementation of the response equations, a noncollinear generalized gradient approximation (GGA) has been used. The present approach enforces a restricted kinetic balance condition for the small-component basis at the integral level, leading to very efficient calculations of the property. We apply the methodology to study relativistic effects on the spin-rotation constants by performing calculations on XHn (n = 1-4) for all elements X in the p-block of the periodic table and comparing the effects of relativity on the nuclear SR tensors to that observed for the nuclear magnetic shielding tensors. Correlation effects as described by the density-functional theory are shown to be significant for the spin-rotation constants, whereas the differences between the use of GGA and hybrid density functionals are much smaller. Our calculated relativistic spin-rotation constants at the DFT level of theory are only in fair agreement with available experimental data. It is shown that the scaling of the relativistic effects for the spin-rotation constants (varying between Z(3.8) and Z(4.5)) is as strong as for the chemical shieldings but with a much smaller prefactor.
International Nuclear Information System (INIS)
Frericks, Bernd B.; Caldarone, Franco C.; Savellano, Dagmar Hoegemann; Stamm, Georg; Kirchhoff, Timm D.; Shin, Hoen-Oh; Galanski, Michael; Nashan, Bjoern; Klempnauer, Juergen; Schenk, Andrea; Selle, Dirk; Spindler, Wolf; Peitgen, Heinz-Otto
2004-01-01
The aim of this study was to evaluate a software tool for non-invasive preoperative volumetric assessment of potential donors in living donated liver transplantation (LDLT). Biphasic helical CT was performed in 56 potential donors. Data sets were post-processed using a non-commercial software tool for segmentation, volumetric analysis and visualisation of liver segments. Semi-automatic definition of liver margins allowed the segmentation of parenchyma. Hepatic vessels were delineated using a region-growing algorithm with automatically determined thresholds. Volumes and shapes of liver segments were calculated automatically based on individual portal-venous branches. Results were visualised three-dimensionally and statistically compared with conventional volumetry and the intraoperative findings in 27 transplanted cases. Image processing was easy to perform within 23 min. Of the 56 potential donors, 27 were excluded from LDLT because of inappropriate liver parenchyma or vascular architecture. Two recipients were not transplanted due to poor clinical conditions. In the 27 transplanted cases, preoperatively visualised vessels were confirmed, and only one undetected accessory hepatic vein was revealed. Calculated graft volumes were 1110±180 ml for right lobes, 820 ml for the left lobe and 270±30 ml for segments II+III. The calculated volumes and intraoperatively measured graft volumes correlated significantly. No significant differences between the presented automatic volumetry and the conventional volumetry were observed. A novel image processing technique was evaluated which allows a semi-automatic volume calculation and 3D visualisation of the different liver segments. (orig.)
International Nuclear Information System (INIS)
Koponen, B.L.; Hampel, V.E.
1982-01-01
This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains - in chronological order - the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41
Fast Near-Field Calculation for Volume Integral Equations for Layered Media
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav
2005-01-01
. Afterwards, the scattered electric field can be easily computed at a regular rectangular grid on any horizontal plane us-ing a 2-dimensional FFT. This approach provides significant speedup in the near-field calculation in comparison to a straightforward numerical evaluation of the ra-diation integral since......An efficient technique based on the Fast Fourier Transform (FFT) for calculating near-field scattering by dielectric objects in layered media is presented. A higher or-der method of moments technique is employed to solve the volume integral equation for the unknown induced volume current density...
Valdman, V. V.; Gridnev, S. O.
2017-10-01
The article examines into the vital issues of measuring and calculating the raw stock volumes in covered storehouses at mining and processing plants. The authors bring out two state-of-the-art high-technology solutions: 1 - to use the ground-based laser scanning system (the method is reasonably accurate and dependable, but costly and time consuming; it also requires the stoppage of works in the storehouse); 2 - to use the fundamentally new computerized stocktaking system in mine surveying for the ore mineral volume calculation, based on the profile digital images. These images are obtained via vertical projection of the laser plane onto the surface of the stored raw materials.
International Nuclear Information System (INIS)
Bhatnagar, S.; Mahecha, J.
2008-09-01
We have employed the framework of Bethe-Salpeter equation under Covariant Instantaneous Ansatz to calculate the leptonic decay constants of unequal mass pseudoscalar mesons. In the Dirac structure of BS wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule, order-by-order in powers of inverse of meson mass. The decay constants are calculated incorporating both Leading Order (LO) as well as Next-to-leading Order (NLO) Dirac covariants. The contribution of both LO as well as NLO covariants to decay constants are studied in detail in this paper. The results are found to improve dramatically, and hence validating the power counting rule which also provides a practical means of incorporating Dirac covariants in the BS wave function of a hadron. (author)
DEFF Research Database (Denmark)
Faber, Rasmus; Sauer, Stephan P. A.
2018-01-01
The basis set convergence of nuclear spin-spin coupling constants (SSCC) calculated at the coupled cluster singles and doubles (CCSD) level has been investigated for ten difficult molecules. Eight of the molecules contain fluorine atoms and nine contain double or triple bonds. Results obtained...
DEFF Research Database (Denmark)
Provasi, Patricio F.; Caputo, María Cristina; Sauer, Stephan P. A.
2012-01-01
A theoretical study of FCCF:(HF)n complexes, with n = 1 and 2, has been carried out by means of ab initio computational methods. Two types of complexes are formed: those with FH···p interactions and those with FH···FC hydrogen bonds. The indirect spin–spin coupling constants have been calculated ...
DEFF Research Database (Denmark)
Enevoldsen, Thomas; Oddershede, Jens; Sauer, Stephan P. A.
1998-01-01
We present correlated calculations of the indirect nuclear spin-spin coupling constants of HD, HF, H2O, CH4, C2H2, BH, AlH, CO and N2 at the level of the second-order polarization propagator approximation (SOPPA) and the second-order polarization propagator approximation with coupled-cluster sing...
Czech Academy of Sciences Publication Activity Database
Heimdal, J.; Kaukonen, M.; Srnec, Martin; Rulíšek, Lubomír; Ryde, U.
2011-01-01
Roč. 12, č. 17 (2011), s. 3337-3347 ISSN 1439-4235 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : acidity constants * enzymes * free-energy * perturbation * molecular modelling * reduction potentials Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.412, year: 2011
Maricq, M Matti; Chase, Richard E; Xu, Ning; Podsiadlik, Diane H
2003-10-01
An improved version of the constant volume sampling (CVS) methodology that overcomes a number of obstacles that exist with the current CVS dilution tunnel system used in most diesel and gasoline vehicle emissions test facilities is presented. The key feature of the new sampling system is the introduction of dilution air immediately at the vehicle tailpipe. In the present implementation, this is done concentrically through a cylindrical air filter. Elimination of the transfer hose conventionally used to connect the tailpipe to the dilution tunnel significantly reduces the hydrocarbon and particulate matter (PM) storage release artifacts that can lead to wildly incorrect particle number counts and to erroneous filter-collected PM mass. It provides accurate representations of particle size distributions for diesel vehicles by avoiding the particle coagulation that occurs in the transfer hose. Furthermore, it removes the variable delay time that otherwise exists between the time that emissions exit the tailpipe and when they are detected in the dilution tunnel. The performance of the improved CVS system is examined with respect to diesel, gasoline, and compressed natural gas vehicles.
Srivastava, Dhananjay Kumar; Dharamshi, Kewal; Agarwal, Avinash Kumar
2011-09-01
In this paper, laser-induced ignition was investigated for compressed natural gas-air mixtures. Experiments were performed in a constant volume combustion chamber, which simulate end of the compression stroke conditions of a SI engine. This chamber simulates the engine combustion chamber conditions except turbulence of air-fuel mixture. It has four optical windows at diametrically opposite locations, which are used for laser ignition and optical diagnostics simultaneously. All experiments were conducted at 10 bar chamber pressure and 373 K chamber temperature. Initial stage of combustion phenomena was visualized by employing Shadowgraphy technique using a high speed CMOS camera. Flame kernel development of the combustible fuel-air mixture was investigated under different relative air-fuel ratios ( λ=1.2-1.7) and the images were interrogated for temporal propagation of flame front. Pressure-time history inside the combustion chamber was recorded and analyzed. This data is useful in characterizing the laser ignition of natural gas-air mixture and can be used in developing an appropriate laser ignition system for commercial use in SI engines.
Energy Technology Data Exchange (ETDEWEB)
Chen, Jacqueline H.; Hawkes, Evatt R.; Sankaran, Ramanan [Reacting Flow Research Department, Combustion Research Facility, Sandia National Laboratories, P.O. Box 969 MS 9051, Livermore, CA 94551-0969 (United States); Mason, Scott D. [Lockheed Martin Corporation, Sunnyvale, CA 94089 (United States); Im, Hong G. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125 (United States)
2006-04-15
The influence of thermal stratification on autoignition at constant volume and high pressure is studied by direct numerical simulation (DNS) with detailed hydrogen/air chemistry with a view to providing better understanding and modeling of combustion processes in homogeneous charge compression-ignition engines. Numerical diagnostics are developed to analyze the mode of combustion and the dependence of overall ignition progress on initial mixture conditions. The roles of dissipation of heat and mass are divided conceptually into transport within ignition fronts and passive scalar dissipation, which modifies the statistics of the preignition temperature field. Transport within ignition fronts is analyzed by monitoring the propagation speed of ignition fronts using the displacement speed of a scalar that tracks the location of maximum heat release rate. The prevalence of deflagrative versus spontaneous ignition front propagation is found to depend on the local temperature gradient, and may be identified by the ratio of the instantaneous front speed to the laminar deflagration speed. The significance of passive scalar mixing is examined using a mixing timescale based on enthalpy fluctuations. Finally, the predictions of the multizone modeling strategy are compared with the DNS, and the results are explained using the diagnostics developed. (author)
Joustra, S.D.; Plas, E.M. van der; Goede, J.; Oostdijk, W.; Delemarre-van de Waal, H.A.; Hack, W.W.M.; Buuren, S. van; Wit, J.M.
2015-01-01
Aim Accurate calculations of testicular volume standard deviation (SD) scores are not currently available. We constructed LMS-smoothed age-reference charts for testicular volume in healthy boys. Methods The LMS method was used to calculate reference data, based on testicular volumes from
Quintens , Hugo; Strozzi , Camille; Zitoun , Ratiba; Bellenoue , Marc
2017-01-01
International audience; The present study aims at characterizing the end-gas auto-ignition of n-decane – air mixtures induced by a flame propagation in a constant volume chamber. A numerical tool is developed, and the study is first focused on academic compressions, e.g. at constant rate of pressure rise. Thermodynamic conditions of transition from deflagration to auto-ignition are first determined, and the involved physical processes are highlighted. A square section combustion chamber is th...
International Nuclear Information System (INIS)
Harding, L.B.; Wagner, A.F.; Bowman, J.M.; Schatz, G.C.; Christoffel, K.
1982-01-01
GVB-POL-CI ab initio calculations of the geometries, energetics, and normal mode frequencies of C 2 H 2 , C 2 H 3 , and the transition state for the addition reaction of H + C 2 H 2 are presented. In addition, normal mode frequencies for the isotopic variants D + C 2 D 2 , D + C 2 H 2 , and H + C 2 D 2 are preented. These results are compared to experimental values for C 2 H 2 and to ab initio values of Hagase and Kern, and semiempirical values of Keil, Lynch, Cowfer, and Michael. The results are also used to calculate the apparent bimolecular addition rate constant using conventional RRKM theory for chemical activation. The calculated rate constants and their isotopic variants are compared as a function of temperature and pressure to available experimental information. The agreement is little different from that obtained by Keil et al. with a similar calculation using semiempirical values for acetylene, transition-state, and vinyl radical properties. In particular, the calculated high-pressure limit of the rate constant appears to be at least 1 order of magnitude higher than the experimental limit. Several possible reasons for this discrepancy are discussed
Energy Technology Data Exchange (ETDEWEB)
Milosevic, M [Institute of Nuclear Sciences Vinca, Beograd (Serbia and Montenegro)
1979-07-01
One-dimensional variational method for cylindrical configuration was applied for calculating group constants, together with effects of elastic slowing down, anisotropic elastic scattering, inelastic scattering, heterogeneous resonance absorption with the aim to include the presence of a number of different isotopes and effects of neutron leakage from the reactor core. Neutron flux shape P{sub 3} and adjoint function are proposed in order to enable calculation of smaller size reactors and inclusion of heterogeneity effects by cell calculations. Microscopic multigroup constants were prepared based on the UKNDL data library. Analytical-numerical approach was applied for solving the equations of the P{sub 3} approximation to obtain neutron flux moments and adjoint functions.
40 CFR 80.1407 - How are the Renewable Volume Obligations calculated?
2010-07-01
... is calculated as follows: ER26MR10.430 Where: x = Individual batch of gasoline produced or imported in calendar year i. n = Total number of batches of gasoline produced or imported in calendar year i. GX = Volume of batch x of gasoline produced or imported, as defined in paragraph (c) of this section...
40 CFR 80.1107 - How is the Renewable Volume Obligation calculated?
2010-07-01
... this section is calculated as follows: ER01MY07.061 Where: x = Individual batch of gasoline produced or imported in calendar year i. n = Total number of batches of gasoline produced or imported in calendar year i. GX = Volume of batch x of gasoline produced or imported, in gallons. y = Individual batch of...
International Nuclear Information System (INIS)
Mueller, K.; Vossebrecker, H.
The Monte Carlo Program ALBEMO calculates the distribution of neutrons and gamma rays in void volumes which are bounded by reflecting walls with x, y, z coordinates. The program is based on the albedo method. The effect of significant simplifying assumptions is investigated. Comparisons with experiments show satisfying agreement
Maskaeva, L. N.; Fedorova, E. A.; Yusupov, R. A.; Markov, V. F.
2018-05-01
The potentiometric titration of tin chloride SnCl2 is performed in the concentration range of 0.00009-1.1 mol/L with a solution of sodium hydroxide NaOH. According to potentiometric titration data based on modeling equilibria in the SnCl2-H2O-NaOH system, basic equations are generated for the main processes, and instability constants are calculated for the resulting hydroxo complexes and equilibrium constants of low-soluble tin(II) compounds. The data will be of interest for specialists in the field of theory of solutions.
Soil map, area and volume calculations in Orrmyrberget catchment basin at Gideaa, Northern Sweden
International Nuclear Information System (INIS)
Ittner, T.; Tammela, P.T.; Gustafsson, E.
1991-06-01
Fallout studies in the Gideaa study site after the Chernobyl fallout in 1986, has come to the point that a more exact surface mapping of the studied catchment basin is needed. This surface mapping is mainly made for area calculations of different soil types within the study site. The mapping focus on the surface, as the study concerns fallout redistribution and it is extended to also include materials down to a depth of 0.5 meter. Volume calculations are made for the various soil materials within the top 0.5 m. These volume and area calculations will then be used in the modelling of the migration and redistribution of the fallout radionuclides within the studied catchment basin. (au)
Zhang, Ji
2013-07-01
This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm and 650. nm, 10. nm FWHM). After calibration, statistical analysis shows that the uncertainty of the two-color temperature is less than 5%, while it is about 50% for the KL factor. This technique is then applied to the spray combustion of biodiesel and diesel fuels under an ambient oxygen concentration of 21% and ambient temperatures of 800, 1000 and 1200. K. The heat release result shows higher energy utilization efficiency for biodiesel compared to diesel under all conditions; meanwhile, diesel shows a higher pressure increase due to its higher heating value. Biodiesel yields a lower temperature inside the flame area, a longer soot lift-off length, and a smaller soot area compared to diesel. Both the KL factor and the total soot with biodiesel are lower than with diesel throughout the entire combustion process, and this difference becomes larger as the ambient temperature decreases. Biodiesel shows approximately 50-100. K lower temperatures than diesel at the quasi-steady stage for 1000 and 1200. K ambient temperature, while diesel shows a lower temperature than biodiesel at 800. K ambient. This result may raise the question of how important the flame temperature is in explaining the higher NO. x emissions often observed during biodiesel combustion. Other factors may also play an important role in controlling NO. x emissions. Both biodiesel and diesel temperature measurements show a monotonic dependence on the ambient temperature. However, the ambient temperature appears to have a more significant effect on the soot formation and oxidation in diesel combustion, while biodiesel combustion soot characteristics shows relative insensitivity to the ambient temperature. © 2013 Elsevier Ltd.
BED-Volume histograms calculation for routine clinical dosimetry in brachytherapy
International Nuclear Information System (INIS)
Galelli, M.; Feroldi, P.
1995-01-01
The consideration of volumes is essential in Brachytherapy clinical dosimetry (I.C.R.U). Indeed, several indices, all based on dose-volume histograms (DVHs), have been designed in order to evaluate: before the therapy the volumetric quality of different possible implant geometries; during the therapy the consistency of the real and the previsional implants. Radiobiological evaluations, considering the dose deposition temporal pattern of treatment, can be usefully added to dosimetric calculations, to compare different treatment schedules. The Linear-Quadratic model is the most used: radiobiological modelisation and Biologically Effective Dose (BED) is principal related dosimetric quantity. Therefore, the consideration of BED-volume histogram (BED-VHs) is a straightforward extension of DVHs. In practice, BED-VHs can help relative comparisons and optimisations in treatment planning when combined to dose-volume histograms. Since 1994 the dosimetric calculations for all the gynecological brachytherapy treatments are performed considering also DVHs and BED-VHs. In this presentation we show the methods of BEDVHs calculation, together with some typical results
Investigations on the necessity of dose calculations for several planes of the target volume
International Nuclear Information System (INIS)
Richter, E.
1987-01-01
In radiotherapy planning, the shape of a target volume can at present be exactly delimited by means of computed tomography. A method often applied is to project the largest target volume scan on the plane of the central ray and to calculate the dose in this plane. This method does not allow to take into account any change of the target volume scan which will be mainly due to the body contours of the patient. The results of dose calculations made in several planes for pharyngeal and laryngeal tumors are presented. With this procedure, 33 out of 60 irradiation techniques for nine tumor sites meet the requirements with regard to the central ray plane. If several planes are regarded, this is only true for ten irradiation plans. If is therefore absolutely necessary to calculate the doses of several planes if the target volume has an irregular shape or if the body contours vary considerably. This is the only way to prevent a false treatment caused by possibly severe dose excesses or dose insufficiencies in radiotherapy. (orig.) [de
A method for bubble volume calculating in vertical two-phase flow
International Nuclear Information System (INIS)
Wang, H Y; Dong, F
2009-01-01
The movement of bubble is a basic subject in gas-liquid two-phase flow research. A method for calculating bubble volume which is one of the most important characters in bubble motion research was proposed. A suit of visualized experimental device was designed and set up. Single bubble rising in stagnant liquid in a rectangular tank was studied using the high-speed video system. Bubbles generated by four orifice with different diameter (1mm, 2mm, 3mm, 4mm) were recorded respectively. Sequences of recorded high-speed images were processed by digital image processing method, such as image noise remove, binary image transform, bubble filling, and so on. then, Several parameters could be obtained from the processed image. Bubble area, equivalent diameter, bubble velocity, bubble acceleration are all indispensable in bubble volume calculating. In order to get the force balance equation, forces that work on bubble along vertical direction, including drag force, virtual mass force, buoyancy, gravity and liquid thrust, were analyzed. Finally, the bubble volume formula could be derived from the force balance equation and bubble parameters. Examples were given to shown the computing process and results. Comparison of the bubble volume calculated by geomettic method and the present method have shown the superiority of the proposed method in this paper.
Directory of Open Access Journals (Sweden)
Hamit Yurtseven
2012-01-01
Full Text Available The temperature dependence of the static dielectric constant ( is calculated close to the smectic A-smectic B ( transition ( = 71.3°C for the liquid crystal compound B5. By expanding the free energy in terms of the order parameter in the mean field theory, the expression for the dielectric susceptibility (dielectric constant is derived and is fitted to the experimental data for which was obtained at the field strengths of 0 and 67 kV/cm from literature. Coefficients in the free energy expansion are determined from our fit for the transition of B5. Our results show that the observed behaviour of the dielectric constant close to the transition in B5 can be described satisfactorily by our mean field model.
International Nuclear Information System (INIS)
Sanchez Mazon, J.; Raba Diez, J. L.; Vazquez Rodriguez, J. A.; Pacheco Baldor, M. T.; Mendiguren Santiago, M. A.
2011-01-01
In the Protocol for the control treatment planning systems with ionizing radiation of the proposed SEFM tests to verify proper operation of the calculation in the evaluation of DVH (Dose Volume Histogram). The calculation of the volume that makes a planner may have important implications because it can trigger an overestimation of the dose or otherwise. We present a comparison of the calculation of volumes estimated with 4 different planners.
Jing, Wei; Roberts, William L.; Fang, Tiegang
2014-01-01
The measurement of the two-color line of sight soot and KL factor for NO.2 diesel and jet-A fuels was conducted in an optical constant volume combustion chamber by using a high speed camera under 1000 K ambient temperature and varied oxygen
Stoll, M.H.C.; Rommets, J.W.; Baar, H.J.W. de
1993-01-01
During the 1989 and 1990 JGOFS North Atlantic Pilot Study a comparison was made between the Coulometric and the acid titration method for determination of total carbon dioxide (TCO2) in seawater. TCO2 and alkalinity have been calculated from acid titration using either the modified Gran plot or the
Calculation of the hyperfine constants of Vk center in CaF2, SrF2 and BaF2
International Nuclear Information System (INIS)
Bufaical, R.F.
1975-03-01
The magnetic hyperfine constants of the V sub(K) center in CaF 2 , SrF 2 and BaF 2 have been calculated, assuming a phenomenological model, based on the F 2 central molecule, to describe the wave function of the defect. The introduction of covalence, with the ions neighboring the central molecule, have shown that this is a better description for the defect than a simple central molecule model. It was also shown that the results for the hyperfine constants are strongly dependent on the relaxations of these neighboring ions, which have been determined by fitting the experimental data. The present results are compared with other previous calculations where similar and different methods have been used. A better description for the wave function of the defect is suggested
Calculation of the hyperfine constants of the V sub (K) center in CaF2, SrF2 e BaF2
International Nuclear Information System (INIS)
Bufaical, R.F.
1975-03-01
The magnetic hyperfine constants of the V sub(K) center in CaF 2 , SrF 2 and BaF 2 have been calculated, assuming a phenomenological model, based on the F - 2 'central molecule', to describe the wave function of the defect. The introduction of covalence with the ions neighboring the 'central molecule', has shown that this is a better description for the defect than a simple 'central molecule' model. It was also shown that the results for the hyperfine constants are strongly dependent on the relaxations of these neighboring ions, which have been determined by fitting the experimental data. The present results are compared with other previous calculations where similar and different methods have been used. A better description for the wave function of the defect is suggested. (author) [pt
Seidu, Issaka; Zhekova, Hristina R; Seth, Michael; Ziegler, Tom
2012-03-08
The performance of the second-order spin-flip constricted variational density functional theory (SF-CV(2)-DFT) for the calculation of the exchange coupling constant (J) is assessed by application to a series of triply bridged Cu(II) dinuclear complexes. A comparison of the J values based on SF-CV(2)-DFT with those obtained by the broken symmetry (BS) DFT method and experiment is provided. It is demonstrated that our methodology constitutes a viable alternative to the BS-DFT method. The strong dependence of the calculated exchange coupling constants on the applied functionals is demonstrated. Both SF-CV(2)-DFT and BS-DFT affords the best agreement with experiment for hybrid functionals.
International Nuclear Information System (INIS)
Sasaki, N.; Miyamura, O.; Nonaka, C.; Muroya, S.
2000-01-01
We evaluate thermodynamical quantities and transport coefficient of a dense and hot hadronic matter based on an event generator URASiMA (Ultra-Relativistic AA collision Simulator based on Multiple Scattering Algorithm). The statistical ensembles in equilibrium with fixed temperature and chemical potential are generated by imposing periodic boundary condition to the simulation of URASiMA, where energy density and baryon number density is conserved. Achievement of the thermal equilibrium and the chemical equilibrium are confirmed by the common value of slope parameter in the energy distributions and the saturation of the numbers of contained particles, respectively. By using the generated ensembles, we investigate the temperature dependence and the chemical potential dependence of the baryon diffusion constant of a dense and hot hadronic matter. (author)
International Nuclear Information System (INIS)
Bogatyrev, I.L.; Bogoslovskaya, G.P.; Zhukov, A.V.; Sorokin, A.P.; Titov, P.A.
1992-01-01
System of constants for mass, impulse and energy conservation equations (drag, mixing, heat transfer coefficients, azimuthal unquality of temperature) is reported in region with small Re number for wide range of geometrical assembly parameters. This system can be used in subchannel calculations of assemblies with natural and mixed convection under conditions with loss of flow accident. The formulae are compared with experimental data. 30 refs.; 12 figs.; 1 tab
Factors affecting volume calculation with single photon emission tomography (SPECT) method
International Nuclear Information System (INIS)
Liu, T.H.; Lee, K.H.; Chen, D.C.P.; Ballard, S.; Siegel, M.E.
1985-01-01
Several factors may influence the calculation of absolute volumes (VL) from SPECT images. The effect of these factors must be established to optimize the technique. The authors investigated the following on the VL calculations: % of background (BG) subtraction, reconstruction filters, sample activity, angular sampling and edge detection methods. Transaxial images of a liver-trunk phantom filled with Tc-99m from 1 to 3 μCi/cc were obtained in 64x64 matrix with a Siemens Rota Camera and MDS computer. Different reconstruction filters including Hanning 20,32, 64 and Butterworth 20, 32 were used. Angular samplings were performed in 3 and 6 degree increments. ROI's were drawn manually and with an automatic edge detection program around the image after BG subtraction. VL's were calculated by multiplying the number of pixels within the ROI by the slice thickness and the x- and y- calibrations of each pixel. One or 2 pixel per slice thickness was applied in the calculation. An inverse correlation was found between the calculated VL and the % of BG subtraction (r=0.99 for 1,2,3 μCi/cc activity). Based on the authors' linear regression analysis, the correct liver VL was measured with about 53% BG subtraction. The reconstruction filters, slice thickness and angular sampling had only minor effects on the calculated phantom volumes. Detection of the ROI automatically by the computer was not as accurate as the manual method. The authors conclude that the % of BG subtraction appears to be the most important factor affecting the VL calculation. With good quality control and appropriate reconstruction factors, correct VL calculations can be achieved with SPECT
Park, J M; Park, S-Y; Ye, S-J; Kim, J H; Carlson, J
2014-01-01
Objective: To present conformity indices (CIs) based on the distance differences between the target volume (TV) and the volume of reference isodose (VRI). Methods: The points on the three-dimensional surfaces of the TV and the VRI were generated. Then, the averaged distances between the points on the TV and the VRI were calculated (CIdistance). The performance of the presented CIs were evaluated by analysing six situations, which were a perfect match, an expansion and a reduction of the distance from the centroid to the VRI compared with the distance from the centroid to the TV by 10%, a lateral shift of the VRI by 3 cm, a rotation of the VRI by 45° and a spherical-shaped VRI having the same volume as the TV. The presented CIs were applied to the clinical prostate and head and neck (H&N) plans. Results: For the perfect match, CIdistance was 0 with 0 as the standard deviation (SD). When expanding and reducing, CIdistance was 10 and −10 with SDs 11. The average value of the CIdistance in the prostate and H&N plans was 0.13 ± 7.44 and 6.04 ± 23.27, respectively. Conclusion: The performance of the CIdistance was equal or better than those of the conventional CIs. Advances in knowledge: The evaluation of target conformity by the distances between the surface of the TV and the VRI could be more accurate than evaluation with volume information. PMID:25225915
On the calculation of {sup 3}J{sub {alpha}{beta}}-coupling constants for side chains in proteins
Energy Technology Data Exchange (ETDEWEB)
Steiner, Denise [Swiss Federal Institute of Technology, Laboratory of Physical Chemistry, ETH (Switzerland); Allison, Jane R. [Massey University Albany, Centre for Theoretical Chemistry and Physics, Institute for Natural Sciences (New Zealand); Eichenberger, Andreas P.; Gunsteren, Wilfred F. van, E-mail: wfvgn@igc.phys.chem.ethz.ch [Swiss Federal Institute of Technology, Laboratory of Physical Chemistry, ETH (Switzerland)
2012-07-15
Structural knowledge about proteins is mainly derived from values of observables, measurable in NMR spectroscopic or X-ray diffraction experiments, i.e. absorbed or scattered intensities, through theoretically derived relationships between structural quantities such as atom positions or torsional angles on the one hand and observable quantities such as squared structure factor amplitudes, NOE intensities or {sup 3}J-coupling constants on the other. The standardly used relation connecting {sup 3}J-couplings to torsional angles is the Karplus relation, which is used in protein structure refinement as well as in the evaluation of simulated properties of proteins. The accuracy of the simple and generalised Karplus relations is investigated using side-chain structural and {sup 3}J{sub {alpha}{beta}}-coupling data for three different proteins, Plastocyanin, Lysozyme, and FKBP, for which such data are available. The results show that the widely used Karplus relations are only a rough estimate for the relation between {sup 3}J{sub {alpha}{beta}}-couplings and the corresponding {chi}{sub 1}-angle in proteins.
Expanding the calculation of activation volumes: Self-diffusion in liquid water
Piskulich, Zeke A.; Mesele, Oluwaseun O.; Thompson, Ward H.
2018-04-01
A general method for calculating the dependence of dynamical time scales on macroscopic thermodynamic variables from a single set of simulations is presented. The approach is applied to the pressure dependence of the self-diffusion coefficient of liquid water as a particularly useful illustration. It is shown how the activation volume associated with diffusion can be obtained directly from simulations at a single pressure, avoiding approximations that are typically invoked.
The (water + acetonitrile) mixture revisited: A new approach for calculating partial molar volumes
International Nuclear Information System (INIS)
Carmen Grande, Maria del; Julia, Jorge Alvarez; Barrero, Carmen R.; Marschoff, Carlos M.; Bianchi, Hugo L.
2006-01-01
Density and viscosity of (water + acetonitrile) mixtures were measured over the whole composition range at the temperatures: (298.15, 303.15, 308.15, 313.15, and 318.15) K. A new mathematical approach was developed which allows the calculation of the derivatives of density with respect to composition avoiding the appearance of local discontinuities. Thus, reliable partial molar volumes and thermal expansion coefficients were obtained
International Nuclear Information System (INIS)
Wright, Graham A.; McDade, Mark; Martin, William; Hutton, William
2002-01-01
Gated SPECT (GSPECT) offers the possibility of obtaining additional functional information from perfusion studies, including calculation of left ventricular ejection fraction (LVEF). The calculation of LVEF relies upon the identification of the endocardial surface, which will be affected by the spatial resolution and statistical noise in the reconstructed images. The aim of this study was to compare LVEFs and ventricular volumes calculated from GSPECT using six reconstruction filters. GSPECT and radionuclide ventriculography (RNVG) were performed on 40 patients; filtered back projection was used to reconstruct the datasets with each filter. LVEFs and volumes were calculated using the Cedars-Sinai QGS package. The correlation coefficient between RNVG and GSPECT ranged from 0.81 to 0.86 with higher correlations for smoother filters. The narrowest prediction interval was 11±2%. There was a trend towards higher LVEF values with smoother filters, the ramp filter yielding LVEFs 2.55±3.10% (p<0.001) lower than the Hann filter. There was an overall fall in ventricular volumes with smoother filters with a mean difference of 13.98±10.15 ml (p<0.001) in EDV between the Butterworth-0.5 and Butterworth-0.3 filters. In conclusion, smoother reconstruction filters lead to lower volumes and higher ejection fractions with the QGS algorithm, with the Butterworth-0.4 filter giving the highest correlation with LVEFs from RNVG. Even if the optimal filter is chosen the uncertainty in the measured ejection fractions is still too great to be clinically acceptable. (author)
Waste Retrieval Sluicing System Campaign Number 3 Solids Volume Transferred Calculation
International Nuclear Information System (INIS)
CAROTHERS, K.G.
1999-01-01
Waste Retrieval Sluicing System (WRSS) operations at tank 241-C-106 began on Wednesday, November 18, 1998. The purpose of this system is to retrieve and transfer the high-heat sludge from the tank for storage in double-shell tank 241-AY-102, thereby resolving the high-heat safety issue for the tank, and to demonstrate modernized past-practice retrieval technology for single-shell tank waste. Performance Agreement (PA) TWR 1.2.2, C-106 Sluicing, was established by the Department of Energy, Office of River Protection (ORP) for achieving completion of sluicing retrieval of waste from tank 241-C-106 by September 30, 1999. This level of sludge removal is defined in the PA as either removal of approximately 72 inches of sludge or removal of 172,000 gallons of sludge (approximately 62 inches) and less than 6,000 gallons (approximately 2 inches) of sludge removal per 12 hour sluice batch for three consecutive batches. Preliminary calculations of the volume of tank 241-C-106 sludge removed as of September 29, 1999 were provided to ORP documenting completion of PA TWR 1.2.2 (Allen 1999a). The purpose of this calculation is to document the final sludge volume removed from tank 241-C-106 up through September 30, 1999. Additionally, the results of an extra batch completed October 6, 1999 is included to show the total volume of sludge removed through the end of WRSS operations. The calculation of the sludge volume transferred from the tank is guided by engineering procedure HNF-SD-WM-PROC-021, Section 15.0,Rev. 3, sub-section 4.4, ''Calculation of Sludge Transferred.''
W-320 waste retrieval sluicing system transfer line flushing volume and frequency calculation
International Nuclear Information System (INIS)
Bailey, J.W.
1997-01-01
The calculations contained in this analysis document establish the technical basis for the volume, frequency, and flushing fluid to be utilized for routine Waste Retrieval Sluicing System (WRSS) process line flushes. The WRSS was installed by Project W-320, Tank 241-C-106 Sluicing. The double contained pipelines being flushed have 4 inch stainless steel primary pipes. The flushes are intended to prevent hydrogen buildup in the transfer lines and to provide ALARA conditions for maintenance personnel
Waste Retrieval Sluicing System Campaign Number 3 Solids Volume Transferred Calculation
International Nuclear Information System (INIS)
CAROTHERS, K.G.
1999-01-01
Waste Retrieval Sluicing System (WRSS) operations at tank 241-C-106 began on Wednesday, November 18,1998. The purpose of this system is to retrieve and transfer the high-heat sludge from the tank for storage in double-shell tank 241-AY-102, thereby resolving the high-heat safety issue for the tank, and to demonstrate modernized past-practice retrieval technology for single-shell tank waste. Performance Agreement (PA) TWR 1.2.2, C-106 Sluicing, was established by the Department of Energy, Office of River Protection (ORP) for achieving completion of sluicing retrieval of waste from tank 241-C-106 by September 30,1999. This level of sludge removal is defined in the PA as either removal of approximately 72 inches of sludge or removal of 172,000 gallons of sludge (approximately 62 inches) and less than 6,000 gallons (approximately 2 inches) of sludge removal per 12 hour sluice batch for three consecutive batches. Preliminary calculations of the volume of tank 241-C-106 sludge removed as of September 29, 1999 were provided to ORP documenting completion of PA TWR 1.2.2 (Allen 1999a). The purpose of this calculation is to document the final sludge volume removed from tank 241-C-106 up through September 30, 1999. Additionally, the results of an extra batch completed October 6, 1999 is included to show the total volume of sludge removed through the end of WRSS operations. The calculation of the sludge volume transferred from the tank is guided by engineering procedure HNF-SD-WM-PROC-021, Section 15.0,Rev. 3, sub-section 4.4, ''Calculation of Sludge Transferred.''
International Nuclear Information System (INIS)
Grigorov, Grigor N.; Chow, James C.L.; Grigorov, Lenko; Jiang, Runqing; Barnett, Rob B.
2006-01-01
The normal tissue complication probability (NTCP) is a predictor of radiobiological effect for organs at risk (OAR). The calculation of the NTCP is based on the dose-volume-histogram (DVH) which is generated by the treatment planning system after calculation of the 3D dose distribution. Including the NTCP in the objective function for intensity modulated radiation therapy (IMRT) plan optimization would make the planning more effective in reducing the postradiation effects. However, doing so would lengthen the total planning time. The purpose of this work is to establish a method for NTCP determination, independent of a DVH calculation, as a quality assurance check and also as a mean of improving the treatment planning efficiency. In the study, the CTs of ten randomly selected prostate patients were used. IMRT optimization was performed with a PINNACLE3 V 6.2b planning system, using planning target volume (PTV) with margins in the range of 2 to 10 mm. The DVH control points of the PTV and OAR were adapted from the prescriptions of Radiation Therapy Oncology Group protocol P-0126 for an escalated prescribed dose of 82 Gy. This paper presents a new model for the determination of the rectal NTCP ( R NTCP). The method uses a special function, named GVN (from Gy, Volume, NTCP), which describes the R NTCP if 1 cm 3 of the volume of intersection of the PTV and rectum (R int ) is irradiated uniformly by a dose of 1 Gy. The function was 'geometrically' normalized using a prostate-prostate ratio (PPR) of the patients' prostates. A correction of the R NTCP for different prescribed doses, ranging from 70 to 82 Gy, was employed in our model. The argument of the normalized function is the R int , and parameters are the prescribed dose, prostate volume, PTV margin, and PPR. The R NTCPs of another group of patients were calculated by the new method and the resulting difference was <±5% in comparison to the NTCP calculated by the PINNACLE3 software where Kutcher's dose
International Nuclear Information System (INIS)
Awasthi, Neha; Ritschel, Thomas; Lipowsky, Reinhard; Knecht, Volker
2013-01-01
Highlights: • ΔG and K eq for NO 2 dimerization and NH 3 synthesis calculated via ab-initio methods. • Vis-á-vis experiments, W1 and CCSD(T) are accurate and G3B3 also does quite well. • CBS-APNO most accurate for NH 3 reaction but shows limitations in modeling NO 2 . • Temperature dependence of ΔG and K eq is calculated for the NH 3 reaction. • Good agreement of calculated K eq with experiments and the van’t Hoff approximation. -- Abstract: Standard quantum chemical methods are used for accurate calculation of thermochemical properties such as enthalpies of formation, entropies and Gibbs energies of formation. Equilibrium reactions are widely investigated and experimental measurements often lead to a range of reaction Gibbs energies and equilibrium constants. It is useful to calculate these equilibrium properties from quantum chemical methods in order to address the experimental differences. Furthermore, most standard calculation methods differ in accuracy and feasibility of the system size. Hence, a systematic comparison of equilibrium properties calculated with different numerical algorithms would provide a useful reference. We select two well-known gas phase equilibrium reactions with small molecules: covalent dimer formation of NO 2 (2NO 2 ⇌ N 2 O 4 ) and the synthesis of NH 3 (N 2 + 3 H 2 ⇌ 2NH 3 ). We test four quantum chemical methods denoted by G3B3, CBS-APNO, W1 and CCSD(T) with aug-cc-pVXZ basis sets (X = 2, 3, and 4), to obtain thermochemical data for NO 2 , N 2 O 4 , and NH 3 . The calculated standard formation Gibbs energies Δ f G° are used to calculate standard reaction Gibbs energies Δ r G° and standard equilibrium constants K eq for the two reactions. Standard formation enthalpies Δ f H° are calculated in a more reliable way using high-level methods such as W1 and CCSD(T). Standard entropies S° for the molecules are calculated well within the range of experiments for all methods, however, the values of standard formation
Alfazazi, Adamu
2016-08-10
The ignition characteristics of isooctane and n-heptane in an ignition quality tester (IQT) were simulated using a two-stage Lagrangian (TSL) model, which is a zero-dimensional (0-D) reactor network method. The TSL model was also used to simulate the ignition delay of n-dodecane and n-heptane in a constant volume combustion chamber (CVCC), which is archived in the engine combustion network (ECN) library (http://www.ca.sandia.gov/ecn). A detailed chemical kinetic model for gasoline surrogates from the Lawrence Livermore National Laboratory (LLNL) was utilized for the simulation of n-heptane and isooctane. Additional simulations were performed using an optimized gasoline surrogate mechanism from RWTH Aachen University. Validations of the simulated data were also performed with experimental results from an IQT at KAUST. For simulation of n-dodecane in the CVCC, two n-dodecane kinetic models from the literature were utilized. The primary aim of this study is to test the ability of TSL to replicate ignition timings in the IQT and the CVCC. The agreement between the model and the experiment is acceptable except for isooctane in the IQT and n-heptane and n-dodecane in the CVCC. The ability of the simulations to replicate observable trends in ignition delay times with regard to changes in ambient temperature and pressure allows the model to provide insights into the reactions contributing towards ignition. Thus, the TSL model was further employed to investigate the physical and chemical processes responsible for controlling the overall ignition under various conditions. The effects of exothermicity, ambient pressure, and ambient oxygen concentration on first stage ignition were also studied. Increasing ambient pressure and oxygen concentration was found to shorten the overall ignition delay time, but does not affect the timing of the first stage ignition. Additionally, the temperature at the end of the first stage ignition was found to increase at higher ambient pressure
Jing, Wei
2016-05-26
Effect of a two-injection strategy associated with a pilot injection on the spray combustion process was investigated under conventional diesel combustion conditions (1000 K and 21% O2 concentration) for a biomass-based renewable diesel fuel, i.e., biomass to liquid (BTL), and a regular No. 2 diesel in a constant volume combustion chamber using multiband flame measurement and two-color pyrometry. The spray combustion flame structure was visualized by using multiband flame measurement to show features of soot formation, high temperature and low temperature reactions, which can be characterized by the narrow-band emissions of radicals or intermediate species such as OH, HCHO, and CH. The objective of this study was to identify the details of multiple injection combustion, including a pilot and a main injection, and to provide further insights on how the two injections interact. For comparison, three injection strategies were considered for both fuels including a two-injection strategy (Case TI), single injection strategy A (Case SA), and single injection strategy B (Case SB). Multiband flame results show a strong interaction, indicated by OH emissions between the pilot injection and the main injection for Case TI while very weak connection is found for the narrow-band emissions acquired through filters with centerlines of 430 nm and 470 nm. A faster flame development is found for the main injection of Case TI compared to Cases SA and SB, which could be due to the high temperature environment and large air entrainment from the pilot injection. A lower soot level is observed for the BTL flame compared to the diesel flame for all three injection types. Case TI has a lower soot level compared to Cases SA and SB for the BTL fuel, while the diesel fuel maintains a similar soot level among all three injection strategies. Soot temperature of Case TI is lower for both fuels, especially for diesel. Based on these results, it is expected that the two-injection strategy could be
Calculated volumes of individual shield volcanoes at the young end of the Hawaiian Ridge
Robinson, Joel E.; Eakins, Barry W.
2006-03-01
High-resolution multibeam bathymetry and a digital elevation model of the Hawaiian Islands are used to calculate the volumes of individual shield volcanoes and island complexes (Niihau, Kauai, Oahu, the Maui Nui complex, and Hawaii), taking into account subsidence of the Pacific plate under the load of the Hawaiian Ridge. Our calculated volume for the Island of Hawaii and its submarine extent (213 × 10 3 km 3) is nearly twice the previous estimate (113 × 10 3 km 3), due primarily to crustal subsidence that had not been accounted for in the earlier work. The volcanoes that make up the Island of Hawaii (Mahukona, Kohala, Mauna Kea, Hualalai, Mauna Loa, Kilauea and Loihi) are generally considered to have been formed within the past million years, and our revised volume for the island indicates that magma supply rates are greater than previously estimated, 0.21 km 3/yr as opposed to ˜ 0.1 km 3/yr. This result also shows that compared with rates calculated for the Hawaiian Islands (0-6 Ma, 0.095 km 3/yr), the Hawaiian Ridge (0-45 Ma, 0.017 km 3/yr), and the Emperor Seamounts (45-80 Ma, 0.010 km 3/yr), magma supply rates have increased dramatically to build the Island of Hawaii.
Li, Chang; Wang, Qing; Shi, Wenzhong; Zhao, Sisi
2018-05-01
The accuracy of earthwork calculations that compute terrain volume is critical to digital terrain analysis (DTA). The uncertainties in volume calculations (VCs) based on a DEM are primarily related to three factors: 1) model error (ME), which is caused by an adopted algorithm for a VC model, 2) discrete error (DE), which is usually caused by DEM resolution and terrain complexity, and 3) propagation error (PE), which is caused by the variables' error. Based on these factors, the uncertainty modelling and analysis of VCs based on a regular grid DEM are investigated in this paper. Especially, how to quantify the uncertainty of VCs is proposed by a confidence interval based on truncation error (TE). In the experiments, the trapezoidal double rule (TDR) and Simpson's double rule (SDR) were used to calculate volume, where the TE is the major ME, and six simulated regular grid DEMs with different terrain complexity and resolution (i.e. DE) were generated by a Gauss synthetic surface to easily obtain the theoretical true value and eliminate the interference of data errors. For PE, Monte-Carlo simulation techniques and spatial autocorrelation were used to represent DEM uncertainty. This study can enrich uncertainty modelling and analysis-related theories of geographic information science.
Bulut, Niyazi; Kłos, Jacek; Roncero, Octavio
2015-06-07
We present accurate state-to-state quantum wave packet calculations of integral cross sections and rate constants for the title reaction. Calculations are carried out on the best available ground 1(2)A' global adiabatic potential energy surface of Deskevich et al. [J. Chem. Phys. 124, 224303 (2006)]. Converged state-to-state reaction cross sections have been calculated for collision energies up to 0.5 eV and different initial rotational and vibrational excitations, DCl(v = 0, j = 0 - 1; v = 1, j = 0). Also, initial-state resolved rate constants of the title reaction have been calculated in a temperature range of 100-400 K. It is found that the initial rotational excitation of the DCl molecule does not enhance reactivity, in contract to the reaction with the isotopologue HCl in which initial rotational excitation produces an important enhancement. These differences between the isotopologue reactions are analyzed in detail and attributed to the presence of resonances for HCl(v = 0, j), absent in the case of DCl(v = 0, j). For vibrational excited DCl(v = 1, j), however, the reaction cross section increases noticeably, what is also explained by another resonance.
Haas, Matthias; Günzel, Karsten; Miller, Kurt; Hamm, Bernd; Cash, Hannes; Asbach, Patrick
2017-01-01
Prostate volume in multiparametric MRI (mpMRI) is of clinical importance. For 3-Tesla mpMRI without endorectal coil, there is no distinctive standard for volume calculation. We tested the accuracy of the ellipsoid formula with planimetric volume measurements as reference and investigated the correlation of gland volume and cancer detection rate on MRI/ultrasound (MRI/US) fusion-guided biopsy. One hundred forty-three patients with findings on 3-Tesla mpMRI suspicious of cancer and subsequent MRI/US fusion-guided targeted biopsy and additional systematic biopsy were analyzed. T2-weighted images were used for measuring the prostate diameters and for planimetric volume measurement by a segmentation software. Planimetric and calculated prostate volumes were compared with clinical data. The median prostate volume was 48.1 ml (interquartile range (IQR) 36.9-62.1 ml). Volume calculated by the ellipsoid formula showed a strong concordance with planimetric volume, with a tendency to underestimate prostate volume (median volume 43.1 ml (IQR 31.2-58.8 ml); r = 0.903, p Tesla mpMRI without endorectal coil. It allows a fast, valid volume calculation in prostate MRI datasets. © 2016 S. Karger AG, Basel.
Zhang, Hui; Zhang, Xin; Truhlar, Donald G; Xu, Xuefei
2017-11-30
The reaction between H and benzene is a prototype for reactions of radicals with aromatic hydrocarbons. Here we report calculations of the reaction rate constants and the branching ratios of the two channels of the reaction (H addition and H abstraction) over a wide temperature and pressure range. Our calculations, obtained with an accurate potential energy surface, are based on variational transition-state theory for the high-pressure limit of the addition reaction and for the abstraction reaction and on system-specific quantum Rice-Ramsperger-Kassel theory calibrated by variational transition-state theory for pressure effects on the addition reaction. The latter is a very convenient way to include variational effects, corner-cutting tunneling, and anharmonicity in falloff calculations. Our results are in very good agreement with the limited experimental data and show the importance of including pressure effects in the temperature interval where the mechanism changes from addition to abstraction. We found a negative temperature effect of the total reaction rate constants at 1 atm pressure in the temperature region where experimental data are missing and accurate theoretical data were previously missing as well. We also calculated the H + C 6 H 6 /C 6 D 6 and D + C 6 H 6 /C 6 D 6 kinetic isotope effects, and we compared our H + C 6 H 6 results to previous theoretical data for H + toluene. We report a very novel nonmonotonic dependence of the kinetic isotope effect on temperature. A particularly striking effect is the prediction of a negative temperature dependence of the total rate constant over 300-500 K wide temperature ranges, depending on the pressure but generally in the range from 600 to 1700 K, which includes the temperature range of ignition in gasoline engines, which is important because aromatics are important components of common fuels.
Wang, Li; Liu, Jing-Yao; Li, Ze-Sheng; Sun, Chia-Chung
2005-01-30
The mechanisms of the SH (SD) radicals with Cl2 (R1), Br2 (R2), and BrCl (R3) are investigated theoretically, and the rate constants are calculated using a dual-level direct dynamics method. The optimized geometries and frequencies of the stationary points are calculated at the MP2/6-311G(d,p) and MPW1K/6-311G(d,p) levels. Higher-level energies are obtained at the approximate QCISD(T)/6-311++G(3df, 2pd) level using the MP2 geometries as well as by the multicoefficient correlation method based on QCISD (MC-QCISD) using the MPW1K geometries. Complexes with energies less than those of the reactants or products are located at the entrance or the exit channels of these reactions, which indicate that the reactions may proceed via an indirect mechanism. The enthalpies of formation for the species XSH/XSD (X = Cl and Br) are evaluated using hydrogenation working reactions method. By canonical variational transition-state theory (CVT), the rate constants of SH and SD radicals with Cl2, Br2, and BrCl are calculated over a wide temperature range of 200-2000 K at the a-QCISD(T)/6-311++G(3df, 2pd)//MP2/6-311G(d, p) level. Good agreement between the calculated and experimental rate constants is obtained in the measured temperature range. Our calculations show that for SH (SD) + BrCl reaction bromine abstraction (R3a or R3a') leading to the formation of BrSH (BrSD) + Cl in a barrierless process dominants the reaction with the branching ratios for channels 3a and 3a' of 99% at 298 K, which is quite different from the experimental result of k3a'/k3' = 54 +/- 10%. Negative activation energies are found at the higher level for the SH + Br2 and SH + BrCl (Br-abstraction) reactions; as a result, the rate constants show a slightly negative temperature dependence, which is consistent with the determination in the literature. The kinetic isotope effects for the three reactions are "inverse". The values of kH/kD are 0.88, 0.91, and 0.69 at room temperature, respectively, and they increase
Calculation of partial molar volume of components in supercritical ammonia synthesis system
Institute of Scientific and Technical Information of China (English)
Cunwen WANG; Chuanbo YU; Wen CHEN; Weiguo WANG; Yuanxin WU; Junfeng ZHANG
2008-01-01
The partial molar volumes of components in supercritical ammonia synthesis system are calculated in detail by the calculation formula of partial molar volume derived from the R-K equation of state under different conditions. The objectives are to comprehend phase beha-vior of components and to provide the theoretic explana-tion and guidance for probing novel processes of ammonia synthesis under supercritical conditions. The conditions of calculation are H2/N2= 3, at a concentra-tion of NH3 in synthesis gas ranging from 2% to 15%, Concentration of medium in supercritical ammonia syn-thesis system ranging from 20% to 50%, temperature ran-ging from 243 K to 699 K and pressure ranging from 0.1 MPa to 187 MPa. The results show that the ammonia synthesis system can reach supercritical state by adding a suitable supercritical medium and then controlling the reaction conditions. It is helpful for the supercritical ammonia synthesis that medium reaches supercritical state under the conditions of the corresponding total pres-sure and components near the normal temperature or near the critical temperature of medium or in the range of tem-perature of industrialized ammonia synthesis.
Directory of Open Access Journals (Sweden)
Tomáš Mikita
2015-01-01
Full Text Available This paper outlines the idea of a precision forestry tool for optimizing clearcut size and shape within the process of forest recovery and its publishing in the form of a web processing service for forest owners on the Internet. The designed tool titled COWRAS (Clearcut Optimization and Wind Risk Assessment is developed for optimization of clearcuts (their location, shape, size, and orientation with subsequent wind risk assessment. The tool primarily works with airborne LiDAR data previously processed to the form of a digital surface model (DSM and a digital elevation model (DEM. In the first step, the growing stock on the planned clearcut determined by its location and area in feature class is calculated (by the method of individual tree detection. Subsequently tree heights from canopy height model (CHM are extracted and then diameters at breast height (DBH and wood volume using the regressions are calculated. Information about wood volume of each tree in the clearcut is exported and summarized in a table. In the next step, all trees in the clearcut are removed and a new DSM without trees in the clearcut is generated. This canopy model subsequently serves as an input for evaluation of wind risk damage by the MAXTOPEX tool (Mikita et al., 2012. In the final raster, predisposition of uncovered forest stand edges (around the clearcut to wind risk is calculated based on this analysis. The entire tool works in the background of ArcGIS server as a spatial decision support system for foresters.
The Implementation of Cumulative Learning Theory in Calculating Triangular Prism and Tube Volumes
Muklis, M.; Abidin, C.; Pamungkas, M. D.; Masriyah
2018-01-01
This study aims at describing the application of cumulative learning theory in calculating the volume of a triangular prism and a tube as well as revealing the students’ responses toward the learning. The research method used was descriptive qualitative with elementary school students as the subjects of the research. Data obtained through observation, field notes, questionnaire, tests, and interviews. The results from the application of cumulative learning theory obtained positive students’ responses in following the learning and students’ learning outcomes was dominantly above the average. This showed that cumulative learning could be used as a reference to be implemented in learning, so as to improve the students’ achievement.
International Nuclear Information System (INIS)
Kirisits, Christian; Wexberg, Paul; Gottsauner-Wolf, Michael; Pokrajac, Boris; Ortmann, Elisabeth; Aiginger, Hannes; Glogar, Dietmar; Poetter, Richard
2001-01-01
Background and purpose: Radioactive stents are under investigation for reduction of coronary restenosis. However, the actual dose delivered to specific parts of the coronary artery wall based on the individual vessel anatomy has not been determined so far. Dose-volume histograms (DVHs) permit an estimation of the actual dose absorbed by the target volume. We present a method to calculate DVHs based on intravascular ultrasound (IVUS) measurements to determine the dose distribution within the vessel wall. Materials and methods: Ten patients were studied by intravascular ultrasound after radioactive stenting (BX Stent, P-32, 15-mm length) to obtain tomographic cross-sections of the treated segments. We developed a computer algorithm using the actual dose distribution of the stent to calculate differential and cumulative DVHs. The minimal target dose, the mean target dose, the minimal doses delivered to 10 and 90% of the adventitia (DV10, DV90), and the percentage of volume receiving a reference dose at 0.5 mm from the stent surface cumulated over 28 days were derived from the DVH plots. Results were expressed as mean±SD. Results: The mean activity of the stents was 438±140 kBq at implantation. The mean reference dose was 111±35 Gy, whereas the calculated mean target dose within the adventitia along the stent was 68±20 Gy. On average, DV90 and DV10 were 33±9 Gy and 117±41 Gy, respectively. Expanding the target volume to include 2.5-mm-long segments at the proximal and distal ends of the stent, the calculated mean target dose decreased to 55±17 Gy, and DV 90 and DV 10 were 6.4±2.4 Gy and 107±36 Gy, respectively. Conclusions: The assessment of DVHs seems in principle to be a valuable tool for both prospective and retrospective analysis of dose-distribution of radioactive stents. It may provide the basis to adapt treatment planning in coronary brachytherapy to the common standards of radiotherapy
International Nuclear Information System (INIS)
Haghighat, A.; Kosaly, G.
1985-01-01
By performing two-group, X-Y, S 4 transport theory calculations with the albedo boundary condition, the effect of heterogeneities on the BWR incore detector has been investigated. The albedo distribution along the boundary of the control volume is obtained using a two-group, homogenous, X-Y diffusion model. Different degrees of homogenization have been examined. Investigation shows that a cell-homogeneous model, with separated bypass region and inner water gap, is a viable alternative to the heterogeneous approach. This finding contradicts earlier predictions of a need for a heterogeneous model. (author)
International Nuclear Information System (INIS)
Nunez, M.; Beretta, M.; Alonso, O.; Alvarez, B.; Canepa, J.; Mut, F.
2002-01-01
Aim: To compare left ventricular ejection fraction (LVEF), end-diastolic volumes (EDV) and end-systolic volumes (ESV) measured by quantitative gated SPECT (QGSPECT) in studies acquired with and without magnification factor (zoom). Material and Methods: We studied 30 consecutive patients (17 men, ages 61±14 years) referred for myocardial perfusion evaluation with a 2-day protocol. Studies were performed after injection of 925 MBq (25 mCi) of 99mTc-MIBI in the resting state. Gated SPECT was first acquired using a x2 zoom factor and immediately repeated with x1 zoom (no magnification), using a 64x64 matrix and 8 frames/cardiac cycle. Patients with arrhythmia were not included in the investigation. According to the median EDV calculated with the x2 zoom acquisition, the population was further divided in two sub-groups regarding the size of the LV cavity. Average LVEF, EDV, ESV and difference between values (delta) were then calculated for the total population and for each sub-group (a and b). Results: For the total population, results are expressed.Pearson correlation showed r=0.954 between LVEF with and without zoom (p<0.0001), but linear regression analysis did not fit a specific model (p=0.18). Median EDV with zoom was 92.5 ml, allowing to separate 15 cases with EDV above (a) and 15 below that value (b). Results for both sub-groups are presented. Conclusion: Calculated LVEF is higher with no zoom, at the expense of decreasing both EDV and ESV. Although differences were very significant for all parameters, ESV changes were specially relevant with no zoom, particularly in patients with smaller hearts. Although good correlation was found between LVEF with and without zoom, no specific correction factor was found to convert one value into the other. Magnification factor should be kept constant in gated SPECT if calculated LVEF values QGSPECT are expected to be reliable, and validation of the method using different zoom factors should be considered
International Nuclear Information System (INIS)
Blokhintsev, L.D.; Igamov, S.B.; Nishonov, MM; Yarmukhamedov, R; Kamimura, M.
2003-01-01
The d(α, γ) 6 Li reaction is one of the sources of 6 Li production in the Big-Bang nuclear synthesis. At present extremely large uncertainties exist on this prediction mainly due to the absence of reliable directly measured cross section (or astrophysical S-factor, S(E)) at astrophysical relevant energies E, including E=0. As far theoretical calculation of the S(E) that have rather large spread. On the other hand, the d(α, γ) 6 Li reaction is predominantly of peripheral character at extremely low energies. Therefore the calculated S(E) at extremely low energies is mainly determined by the nuclear vertex constant (NVC) (or respective asymptotic normalization constant (ANC)) for the virtual decay 6 Li→α + d. Taking into account this circumstance we develop a method of calculation of the NVC for the virtual decay 6 Li→α + d for the subsequent application of the calculated one to the direct radiative capture d(α, γ) 6 Li cross - section (or astrophysical S-factor) calculation at extremely low energies E, including E=0. The developed method is based on the three-body Faddeev approach which is applied for the α-d scattering by using different forms of the NN- and αN-potentials. As a result the values of NVC and respective ANC for 6 Li→α + d virtual decay are obtained using two forms both for NN- and for αN-potential. They are the separable potentials with Yamaguchi type form factor and Paris potential with PEST 16 form factor for the NN- potential and Yamaguchi type form factor and Sack-Biedenharn-Breit potential for the αN- potential. A noticeable sensitivity to used forms of the NN- and αN- potential occurs both for the calculated NVC (or ANC) and astrophysical S- factor S(E) of the direct radiative capture d(α, γ) 6 Li reaction at extremely low energies E (≤100 keV), including the value E=0. The calculated S(E) have been obtained using the information about the NVC values. The obtained values of NVC and S(E) are compared with those of obtained
International Nuclear Information System (INIS)
Zarycz, M. Natalia C.; Provasi, Patricio F.; Sauer, Stephan P. A.
2015-01-01
It is investigated, whether the number of excited (pseudo)states can be truncated in the sum-over-states expression for indirect spin-spin coupling constants (SSCCs), which is used in the Contributions from Localized Orbitals within the Polarization Propagator Approach and Inner Projections of the Polarization Propagator (IPPP-CLOPPA) approach to analyzing SSCCs in terms of localized orbitals. As a test set we have studied the nine simple compounds, CH 4 , NH 3 , H 2 O, SiH 4 , PH 3 , SH 2 , C 2 H 2 , C 2 H 4 , and C 2 H 6 . The excited (pseudo)states were obtained from time-dependent density functional theory (TD-DFT) calculations with the B3LYP exchange-correlation functional and the specialized core-property basis set, aug-cc-pVTZ-J. We investigated both how the calculated coupling constants depend on the number of (pseudo)states included in the summation and whether the summation can be truncated in a systematic way at a smaller number of states and extrapolated to the total number of (pseudo)states for the given one-electron basis set. We find that this is possible and that for some of the couplings it is sufficient to include only about 30% of the excited (pseudo)states
Energy Technology Data Exchange (ETDEWEB)
Zarycz, M. Natalia C., E-mail: mnzarycz@gmail.com; Provasi, Patricio F., E-mail: patricio@unne.edu.ar [Department of Physics, University of Northeastern - CONICET, Av. Libertad 5500, Corrientes W3404AAS (Argentina); Sauer, Stephan P. A., E-mail: sauer@kiku.dk [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø (Denmark)
2015-12-28
It is investigated, whether the number of excited (pseudo)states can be truncated in the sum-over-states expression for indirect spin-spin coupling constants (SSCCs), which is used in the Contributions from Localized Orbitals within the Polarization Propagator Approach and Inner Projections of the Polarization Propagator (IPPP-CLOPPA) approach to analyzing SSCCs in terms of localized orbitals. As a test set we have studied the nine simple compounds, CH{sub 4}, NH{sub 3}, H{sub 2}O, SiH{sub 4}, PH{sub 3}, SH{sub 2}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}. The excited (pseudo)states were obtained from time-dependent density functional theory (TD-DFT) calculations with the B3LYP exchange-correlation functional and the specialized core-property basis set, aug-cc-pVTZ-J. We investigated both how the calculated coupling constants depend on the number of (pseudo)states included in the summation and whether the summation can be truncated in a systematic way at a smaller number of states and extrapolated to the total number of (pseudo)states for the given one-electron basis set. We find that this is possible and that for some of the couplings it is sufficient to include only about 30% of the excited (pseudo)states.
International Nuclear Information System (INIS)
Uelhoff, W.; Mika, K.
1975-05-01
The shape and stability of menisci occurring during Czochralski growth have been studied by means of numerical methods for the case of the free surface. The existence of minimal joining angles is shown, beyond which the growing crystal will separate from the melt. The dependence of the interface height on the joining angle for different crystal diameters was calculated. The maximum stable heights and the corresponding joining angles were determined as a function of crystal diameter. A method for measuring the capillary constant of the melt during Czochralski growth is proposed. The results are compared with known analytical approximations. Limitations of the applications caused by a finite crucible radius or low g values are pointed out. For practical use the following functions have been tabulated: 1) meniscus height in dependence on joining angle and crystal radius, 2) the radius-height-ratio in dependence on radius and angle for the calculation of the capillary constant, 3) the maximum stable height and the corresponding growth angle as a function of crystal radius. (orig.) [de
Wang, K.; Li, S.; Jönsson, P.; Fu, N.; Dang, W.; Guo, X. L.; Chen, C. Y.; Yan, J.; Chen, Z. B.; Si, R.
2017-01-01
Extensive self-consistent multi-configuration Dirac-Fock (MCDF) calculations and second-order many-body perturbation theory (MBPT) calculations are performed for the lowest 272 states belonging to the 2s22p3, 2s2p4, 2p5, 2s22p23l, and 2s2p33l (l=s, p, d) configurations of N-like Kr XXX. Complete and consistent data sets of level energies, wavelengths, line strengths, oscillator strengths, lifetimes, AJ, BJ hyperfine interaction constants, Landé gJ-factors, and electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2), magnetic quadrupole (M2) transition rates among all these levels are given. The present MCDF and MBPT results are compared with each other and with other available experimental and theoretical results. The mean relative difference between our two sets of level energies is only about 0.003% for these 272 levels. The accuracy of the present calculations are high enough to facilitate identification of many observed spectral lines. These accurate data can be served as benchmark for other calculations and can be useful for fusion plasma research and astrophysical applications.
Energy Technology Data Exchange (ETDEWEB)
Santos, Cesar A.G.; Correa, Jorge E. [Para Univ., Belem (Brazil). Centro Tecnologico. Dept. de Engenharia Mecanica]. E-mails: gsantos@ufpa.br; jecorrea@amazon.com.br
2000-07-01
This work performs a comparative analysis among the constant and variable air volume multi zones acclimation systems, used for provide the thermal comfort in buildings. The work used the simulation HVAC2KIT computer program. The results of sensible and latent heats transfer rates on the cooling and dehumidification, inflating fan capacity, and heat transfer on the final heating condenser were obtained and analysed for the climate conditions of the Brazilian city of Belem from Para State, presenting hot and humid climate during all the year.
Directory of Open Access Journals (Sweden)
DanFang Yan
Full Text Available OBJECTS: To introduce a new method for generating the clinical target volume (CTV from gross tumor volume (GTV using the geodesic distance calculation for glioma. METHODS: One glioblastoma patient was enrolled. The GTV and natural barriers were contoured on each slice of the computer tomography (CT simulation images. Then, a graphic processing unit based on a parallel Euclidean distance transform was used to generate the CTV considering natural barriers. Three-dimensional (3D visualization technique was applied to show the delineation results. Speed of operation and precision were compared between this new delineation method and the traditional method. RESULTS: In considering spatial barriers, the shortest distance from the point sheltered from these barriers equals the sum of the distance along the shortest path between the two points; this consists of several segments and evades the spatial barriers, rather than being the direct Euclidean distance between two points. The CTV was generated irregularly rather than as a spherical shape. The time required to generate the CTV was greatly reduced. Moreover, this new method improved inter- and intra-observer variability in defining the CTV. CONCLUSIONS: Compared with the traditional CTV delineation, this new method using geodesic distance calculation not only greatly shortens the time to modify the CTV, but also has better reproducibility.
FORMATION CONSTANTS AND THERMODYNAMIC ...
African Journals Online (AJOL)
KEY WORDS: Metal complexes, Schiff base ligand, Formation constant, DFT calculation ... best values for the formation constants of the proposed equilibrium model by .... to its positive charge distribution and the ligand deformation geometry.
Electromagnetic corrections to pseudoscalar decay constants
Energy Technology Data Exchange (ETDEWEB)
Glaessle, Benjamin Simon
2017-03-06
First principles Lattice quantum chromodynamics (LQCD) calculations enable the determination of low energy hadronic amplitudes. Precision LQCD calculations with relative errors smaller than approximately 1% require the inclusion of electromagnetic effects. We demonstrate that including (quenched) quantum electrodynamics effects in the LQCD calculation effects the values obtained for pseudoscalar decay constants in the per mille range. The importance of systematic effects, including finite volume effects and the charge dependence of renormalization and improvement coefficients, is highlighted.
Kou, Jisheng; Sun, Shuyu; Wang, Xiuhua
2016-01-01
In this paper, we propose an energy-stable evolution method for the calculation of the phase equilibria under given volume, temperature, and moles (VT-flash). An evolution model for describing the dynamics of two-phase fluid system is based on Fick
International Nuclear Information System (INIS)
1995-09-01
Volume one contains calculations for: embankment design--embankment material properties; Union Carbide site--bedrock contours; vicinity properties--origin of contamination; North Continent and Union Carbide sites contaminated materials--excavation quantities; and demolition debris--quantity estimate
National Oceanic and Atmospheric Administration, Department of Commerce — The dataset consists of calculated annual and monthly mean ocean volume transport stream function on 1 degree resolution using the WOA13 (T, S) and corresponding...
Revised Calculated Volumes Of Individual Shield Volcanoes At The Young End Of The Hawaiian Ridge
Robinson, J. E.; Eakins, B. W.
2003-12-01
Recent, high-resolution multibeam bathymetry and a digital elevation model of the Hawaiian Islands allow us to recalculate Bargar and Jackson's [1974] volumes of coalesced volcanic edifices (Hawaii, Maui-Nui, Oahu, Kauai, and Niihau) and individual shield volcanoes at the young end of the Hawaiian Ridge, taking into account subsidence of the Pacific plate under the load of the volcanoes as modeled by Watts and ten Brink [1989]. Our volume for the Island of Hawaii (2.48 x105 km3) is twice the previous estimate (1.13 x105 km3), due primarily to crustal subsidence, which had not been accounted for in the earlier work. The volcanoes that make up the Hawaii edifice (Mahukona, Kohala, Mauna Kea, Hualalai, Mauna Loa, Kilauea, and Loihi) are generally considered to have formed within the past million years and our revised volume for Hawaii indicates that either magma-supply rates are greater than previously estimated (0.25 km3/yr as opposed to 0.1 km3/yr) or that Hawaii's volcanoes have erupted over a longer period of time (>1 million years). Our results also indicate that magma supply rates have increased dramatically to build the Hawaiian edifices: the average rate of the past 5 million years (0.096 km3/yr) is substantially greater than the overall average of the Hawaiian Ridge (0.018km3/yr) or Emperor Seamounts (0.012 km3/yr) as calculated by Bargar and Jackson, and that rates within the past million years are greater still (0.25 km3/yr). References: Bargar, K. E., and Jackson, E. D., 1974, Calculated volumes of individual shield volcanoes along the Hawaiian-Emperor Chain, Jour. Research U.S. Geol. Survey, Vol. 2, No. 5, p. 545-550. Watts, A. B., and ten Brink, U. S., 1989, Crustal structure, flexure, and subsidence history of the Hawaiian Islands, Jour. Geophys. Res., Vol. 94, No. B8, p. 10,473-10,500.
... ounces of regular beer, 5 ounces of table wine, or 1.5 ounces of 80-proof distilled spirits. Distilled spirits include vodka, whiskey, gin, rum, and ... is 5% alcohol by volume (alc/vol), table wine is about 12% alc/vol, and straight 80-proof distilled spirits is 40% alc/vol. The percent alcohol by ...
Directory of Open Access Journals (Sweden)
Kiswanto Gandjar
2017-01-01
Full Text Available The increase in the volume of rough machining on the CBV area is one of the indicators of increased efficiencyof machining process. Normally, this area is not subject to the rough machining process, so that the volume of the rest of the material is still big. With the addition of CC point and tool orientation to CBV area on a complex surface, the finishing will be faster because the volume of the excess material on this process will be reduced. This paper presents a method for volume calculation of the parts which do not allow further occurrence of the machining process, particulary for rough machining on a complex object. By comparing the total volume of raw materials and machining area volume, the volume of residual material,on which machining process cannot be done,can be determined. The volume of the total machining area has been taken into account for machiningof the CBV and non CBV areas. By using delaunay triangulation for the triangle which includes the machining and CBV areas. The volume will be calculated using Divergence(Gaussian theorem by focusing on the direction of the normal vector on each triangle. This method can be used as an alternative to selecting tothe rough machining methods which select minimum value of nonmachinable volume so that effectiveness can be achieved in the machining process.
Jing, Wei; Roberts, William L.; Fang, Tiegang
2013-01-01
This work investigates the effects of ambient conditions on diesel spray combustion in an optically accessible, constant volume chamber using a single-nozzle fuel injector. The ambient O2 concentration was varied between five discrete values from 10% to 21% and three different ambient temperatures (800 K, 1000 K, and 1200 K). These conditions simulate different exhaust gas recirculation (EGR) levels and ambient temperatures in diesel engines. Both conventional diesel combustion and low temperature combustion (LTC) modes were observed under these conditions. A transient analysis and a quasi-steady state analysis are employed in this article. The transient analysis focuses on the flame development from beginning to the end, illustrating how the flame structure changes during this process; the quasi-steady state analysis focuses on the stable flame structure. The transient analysis was conducted using high-speed imaging of both OH* chemiluminescence and natural luminosity (NL). In addition, three different images were acquired using an ICCD camera, corresponding to OH* chemiluminescence, narrow-band flame emission at 430 nm (Band A) and at 470 nm (Band B), and were used to investigate the quasi-steady state combustion process. From the transient analysis, it was found that the NL signal becomes stronger and confined to narrow regions when the temperature and O2 concentration increase during the development of flame. The OH* intensity is much lower for the 10% ambient O2 and 800 K conditions compared to the higher temperatures and O2 levels. This implies the occurrence of LTC under these conditions. Results from the quasi-steady combustion stage indicate that high-temperature reactions effectively oxidize the soot in the downstream locations where only OH* signal is observed. In addition, an area was calculated for each spectral region, and results show that the area of Band A and Band B emissions in these images is larger than the area of OH* emissions at the lower O2
Jing, Wei
2013-09-02
This work investigates the effects of ambient conditions on diesel spray combustion in an optically accessible, constant volume chamber using a single-nozzle fuel injector. The ambient O2 concentration was varied between five discrete values from 10% to 21% and three different ambient temperatures (800 K, 1000 K, and 1200 K). These conditions simulate different exhaust gas recirculation (EGR) levels and ambient temperatures in diesel engines. Both conventional diesel combustion and low temperature combustion (LTC) modes were observed under these conditions. A transient analysis and a quasi-steady state analysis are employed in this article. The transient analysis focuses on the flame development from beginning to the end, illustrating how the flame structure changes during this process; the quasi-steady state analysis focuses on the stable flame structure. The transient analysis was conducted using high-speed imaging of both OH* chemiluminescence and natural luminosity (NL). In addition, three different images were acquired using an ICCD camera, corresponding to OH* chemiluminescence, narrow-band flame emission at 430 nm (Band A) and at 470 nm (Band B), and were used to investigate the quasi-steady state combustion process. From the transient analysis, it was found that the NL signal becomes stronger and confined to narrow regions when the temperature and O2 concentration increase during the development of flame. The OH* intensity is much lower for the 10% ambient O2 and 800 K conditions compared to the higher temperatures and O2 levels. This implies the occurrence of LTC under these conditions. Results from the quasi-steady combustion stage indicate that high-temperature reactions effectively oxidize the soot in the downstream locations where only OH* signal is observed. In addition, an area was calculated for each spectral region, and results show that the area of Band A and Band B emissions in these images is larger than the area of OH* emissions at the lower O2
Test of Effective Solid Angle code for the efficiency calculation of volume source
Energy Technology Data Exchange (ETDEWEB)
Kang, M. Y.; Kim, J. H.; Choi, H. D. [Seoul National Univ., Seoul (Korea, Republic of); Sun, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2013-10-15
It is hard to determine a full energy (FE) absorption peak efficiency curve for an arbitrary volume source by experiment. That's why the simulation and semi-empirical methods have been preferred so far, and many works have progressed in various ways. Moens et al. determined the concept of effective solid angle by considering an attenuation effect of γ-rays in source, media and detector. This concept is based on a semi-empirical method. An Effective Solid Angle code (ESA code) has been developed for years by the Applied Nuclear Physics Group in Seoul National University. ESA code converts an experimental FE efficiency curve determined by using a standard point source to that for a volume source. To test the performance of ESA Code, we measured the point standard sources and voluminous certified reference material (CRM) sources of γ-ray, and compared with efficiency curves obtained in this study. 200∼1500 KeV energy region is fitted well. NIST X-ray mass attenuation coefficient data is used currently to check for the effect of linear attenuation only. We will use the interaction cross-section data obtained from XCOM code to check the each contributing factor like photoelectric effect, incoherent scattering and coherent scattering in the future. In order to minimize the calculation time and code simplification, optimization of algorithm is needed.
Huizinga, Richard J.
2014-01-01
Streamflow data, basin characteristics, and rainfall data from 39 streamflow-gaging stations for urban areas in and adjacent to Missouri were used by the U.S. Geological Survey in cooperation with the Metropolitan Sewer District of St. Louis to develop an initial abstraction and constant loss model (a time-distributed basin-loss model) and a gamma unit hydrograph (GUH) for urban areas in Missouri. Study-specific methods to determine peak streamflow and flood volume for a given rainfall event also were developed.
A new approach for calculation of volume confined by ECR surface and its area in ECR ion source
International Nuclear Information System (INIS)
Filippov, A.V.
2007-01-01
The volume confined by the resonance surface and its area are important parameters of the balance equations model for calculation of ion charge-state distribution (CSD) in the electron-cyclotron resonance (ECR) ion source. A new approach for calculation of these parameters is given. This approach allows one to reduce the number of parameters in the balance equations model
Calculation of Smith-Purcell radiation from a volume strip grating
International Nuclear Information System (INIS)
Kube, G.
2005-01-01
Smith-Purcell radiation is generated by a charged particle beam passing close to the surface of a diffraction grating. Experimental investigations show a strong dependency of the emitted radiation intensity on the form of the grating profile. This influence is expressed by the radiation factor which is a measure of the grating efficiency, in close analogy to reflection coefficients of optical grating theories. The radiation factor depends on beam energy and observation geometry. Up to now calculations for radiation factors exist for lamellar, sinusoidal and echelette-type grating profiles. In this paper, calculations of Smith-Purcell radiation factors for volume strip gratings which are separated by vacuum gaps are presented. They are based on the modal expansion method and restricted to perfectly conducting grating surfaces and to electron trajectories perpendicular to the grating grooves. An infinite system of coupled linear algebraic equations for the scattered and the transmitted wave amplitudes is derived by imposing the continuity condition at the open end of the grooves, and by the boundary conditions at the remaining part of the interface. Numerical results are presented and discussed in view of using Smith-Purcell radiation for particle beam diagnostic purposes
Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke
2017-08-05
In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH 4 + strategy for ethylene and SO 2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO 2 from fruits. It was satisfied that trace ethylene and SO 2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO 2 during the entire LVCC sampling process were proved to be gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.
Farrance, Ian; Frenkel, Robert
2014-02-01
The Guide to the Expression of Uncertainty in Measurement (usually referred to as the GUM) provides the basic framework for evaluating uncertainty in measurement. The GUM however does not always provide clearly identifiable procedures suitable for medical laboratory applications, particularly when internal quality control (IQC) is used to derive most of the uncertainty estimates. The GUM modelling approach requires advanced mathematical skills for many of its procedures, but Monte Carlo simulation (MCS) can be used as an alternative for many medical laboratory applications. In particular, calculations for determining how uncertainties in the input quantities to a functional relationship propagate through to the output can be accomplished using a readily available spreadsheet such as Microsoft Excel. The MCS procedure uses algorithmically generated pseudo-random numbers which are then forced to follow a prescribed probability distribution. When IQC data provide the uncertainty estimates the normal (Gaussian) distribution is generally considered appropriate, but MCS is by no means restricted to this particular case. With input variations simulated by random numbers, the functional relationship then provides the corresponding variations in the output in a manner which also provides its probability distribution. The MCS procedure thus provides output uncertainty estimates without the need for the differential equations associated with GUM modelling. The aim of this article is to demonstrate the ease with which Microsoft Excel (or a similar spreadsheet) can be used to provide an uncertainty estimate for measurands derived through a functional relationship. In addition, we also consider the relatively common situation where an empirically derived formula includes one or more 'constants', each of which has an empirically derived numerical value. Such empirically derived 'constants' must also have associated uncertainties which propagate through the functional relationship
Energy Technology Data Exchange (ETDEWEB)
Wu Yurong [College of Electromechanical Engineering, Hunan University of Science and Technology, Xiantang 411201 (China); Hu Wangyu [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: wangyuhu2001cn@yahoo.com.cn; Han Shaochang [Department of Applied Physics, Hunan University, Changsha 410082 (China)
2008-10-01
First-principles calculations have been used to study the elastic and electronic properties of ductility rare-earth alloy YM (M=Ag, Cu, Rh) systems. The ductility mechanism for these alloys is studied from microscopic aspect, via electronic density of states (DOS). The Fermi energy lies near a local minimum, and the hybridization is stronger than that of the common NiAl alloy, demonstrating that the ductility of these alloys is much better than that of NiAl alloy. Elastic modulus, namely, shear modulus C'=(C{sub 11}-C{sub 12})/2, bulk modulus B and C{sub 44} are calculated by volume-conserving orthorhombic, hydrostatic pressure and tri-axial shear strain, respectively. Moreover, lattice parameters, antiphase boundary (APB) energies and unstable stacking fault energies of these alloys are also studied. The APB energies are greater than the unstable stacking fault energies for these alloy systems, and this is a characteristic of the ductility rare-earth alloy. The APB energies of YRh are the highest ones in these three YM alloys, which make dislocation dissociation difficult. The DOS and APB energy results show that the ductility of YRh may be worst in these three YM systems.
International Nuclear Information System (INIS)
Wu Yurong; Hu Wangyu; Han Shaochang
2008-01-01
First-principles calculations have been used to study the elastic and electronic properties of ductility rare-earth alloy YM (M=Ag, Cu, Rh) systems. The ductility mechanism for these alloys is studied from microscopic aspect, via electronic density of states (DOS). The Fermi energy lies near a local minimum, and the hybridization is stronger than that of the common NiAl alloy, demonstrating that the ductility of these alloys is much better than that of NiAl alloy. Elastic modulus, namely, shear modulus C'=(C 11 -C 12 )/2, bulk modulus B and C 44 are calculated by volume-conserving orthorhombic, hydrostatic pressure and tri-axial shear strain, respectively. Moreover, lattice parameters, antiphase boundary (APB) energies and unstable stacking fault energies of these alloys are also studied. The APB energies are greater than the unstable stacking fault energies for these alloy systems, and this is a characteristic of the ductility rare-earth alloy. The APB energies of YRh are the highest ones in these three YM alloys, which make dislocation dissociation difficult. The DOS and APB energy results show that the ductility of YRh may be worst in these three YM systems
International Nuclear Information System (INIS)
Schatz, G.C.; Walch, S.P.; Wagner, A.F.
1980-01-01
We present ab initio (GVB--POL--CI) calculations for enough of the region about the abstraction and exchange saddle points for H(T)+CH 4 (CD 4 ) to perform a full normal mode analysis of the transition states. The resulting normal mode frequencies are compared to four other published surfaces: an ab initio UHF--SCF calculation by Carsky and Zahradnik, a semiempirical surface by Raff, and two semiempirical surfaces by Kurylo, Hollinden, and Timmons. Significant quantitative and qualitative differences exist between the POL--CI results and those of the other surfaces. Transition state theory rate constants and vibrationally adiabatic reaction threshold energies were computed for all surfaces and compared to available experimental values. For abstraction, the POL--CI rates are in good agreement with experimental rates and in better agreement than are the rates of any of the other surfaces. For exchange, uncertainties in the experimental values and in the importance of vibrationally nonadiabatic effects cloud the comparison of theory to experiment. Tentative conclusions are that the POL--CI barrier is too low by several kcal. Unless vibrationaly nonadiabatic effects are severe, the POL--CI surface is still in better agreement with experiment than are the other surfaces. The rates for a simple 3-atom transition state theory model (where CH 3 is treated as an atom) are compared to the rates for the full 6-atom model. The kinetic energy coupling of reaction coordinate modes to methyl group modes is identified as being of primary importance in determining the accuracy of the 3-atom model for this system. Substantial coupling in abstraction, but not exchange, causes the model to fail for abstraction but succeed for exchange
Kou, Jisheng
2016-02-25
In this paper, we propose an energy-stable evolution method for the calculation of the phase equilibria under given volume, temperature, and moles (VT-flash). An evolution model for describing the dynamics of two-phase fluid system is based on Fick’s law of diffusion for multi-component fluids and the Peng-Robinson equation of state. The mobility is obtained from diffusion coefficients by relating the gradient of chemical potential to the gradient of molar density. The evolution equation for moles of each component is derived using the discretization of diffusion equations, while the volume evolution equation is constructed based on the mechanical mechanism and the Peng-Robinson equation of state. It is proven that the proposed evolution system can well model the VT-flash problem, and moreover, it possesses the property of total energy decay. By using the Euler time scheme to discretize this evolution system, we develop an energy stable algorithm with an adaptive choice strategy of time steps, which allows us to calculate the suitable time step size to guarantee the physical properties of moles and volumes, including positivity, maximum limits, and correct definition of the Helmhotz free energy function. The proposed evolution method is also proven to be energy-stable under the proposed time step choice. Numerical examples are tested to demonstrate efficiency and robustness of the proposed method.
Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke
2017-08-01
In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.
Energy Technology Data Exchange (ETDEWEB)
Gomez-Tenedor Alonso, S.; Rincon Perez, M.; Penedo Cobos, J. M.; Garcia Castejon, M. A.
2011-07-01
The discrepancies in the calculation of the same volume between different planning systems impact on dose-volume histograms and therefore clinical assessment of dosimetry for patients. The transfer, by a local network, tomographic study (CT) and contours of critical organs of patients, between our two planning systems allows us to evaluate the calculation of identical volumes.
Park, Kyungnam; Lee, Jangyoung; Kim, Soo-Young; Kim, Jinwoo; Kim, Insoo; Choi, Seung Pill; Jeong, Sikyung; Hong, Sungyoup
2013-06-01
This study assessed the method of fluid infusion control using an IntraVenous Infusion Controller (IVIC). Four methods of infusion control (dial flow controller, IV set without correction, IV set with correction and IVIC correction) were used to measure the volume of each technique at two infusion rates. The infused fluid volume with a dial flow controller was significantly larger than other methods. The infused fluid volume was significantly smaller with an IV set without correction over time. Regarding the concordance correlation coefficient (CCC) of infused fluid volume in relation to a target volume, IVIC correction was shown to have the highest level of agreement. The flow rate measured in check mode showed a good agreement with the volume of collected fluid after passing through the IV system. Thus, an IVIC could assist in providing an accurate infusion control. © 2013 Wiley Publishing Asia Pty Ltd.
Kou, Jisheng
2017-09-30
Capillary pressure can significantly affect the phase properties and flow of liquid-gas fluids in porous media, and thus, the phase equilibrium calculation incorporating capillary pressure is crucial to simulate such problems accurately. Recently, the phase equilibrium calculation at specified moles, volume and temperature (NVT-flash) becomes an attractive issue. In this paper, capillarity is incorporated into the phase equilibrium calculation at specified moles, volume and temperature. A dynamical model for such problem is developed for the first time by using the laws of thermodynamics and Onsager\\'s reciprocal principle. This model consists of the evolutionary equations for moles and volume, and it can characterize the evolutionary process from a non-equilibrium state to an equilibrium state in the presence of capillarity effect at specified moles, volume and temperature. The phase equilibrium equations are naturally derived. To simulate the proposed dynamical model efficiently, we adopt the convex-concave splitting of the total Helmholtz energy, and propose a thermodynamically stable numerical algorithm, which is proved to preserve the second law of thermodynamics at the discrete level. Using the thermodynamical relations, we derive a phase stability condition with capillarity effect at specified moles, volume and temperature. Moreover, we propose a stable numerical algorithm for the phase stability testing, which can provide the feasible initial conditions. The performance of the proposed methods in predicting phase properties under capillarity effect is demonstrated on various cases of pure substance and mixture systems.
Joustra, Sjoerd D; van der Plas, Evelyn M; Goede, Joery; Oostdijk, Wilma; Delemarre-van de Waal, Henriette A; Hack, Wilfried W M; van Buuren, Stef; Wit, Jan M
2015-06-01
Accurate calculations of testicular volume standard deviation (SD) scores are not currently available. We constructed LMS-smoothed age-reference charts for testicular volume in healthy boys. The LMS method was used to calculate reference data, based on testicular volumes from ultrasonography and Prader orchidometer of 769 healthy Dutch boys aged 6 months to 19 years. We also explored the association between testicular growth and pubic hair development, and data were compared to orchidometric testicular volumes from the 1997 Dutch nationwide growth study. The LMS-smoothed reference charts showed that no revision of the definition of normal onset of male puberty - from nine to 14 years of age - was warranted. In healthy boys, the pubic hair stage SD scores corresponded with testicular volume SD scores (r = 0.394). However, testes were relatively small for pubic hair stage in Klinefelter's syndrome and relatively large in immunoglobulin superfamily member 1 deficiency syndrome. The age-corrected SD scores for testicular volume will aid in the diagnosis and follow-up of abnormalities in the timing and progression of male puberty and in research evaluations. The SD scores can be compared with pubic hair SD scores to identify discrepancies between cell functions that result in relative microorchidism or macroorchidism. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
International Nuclear Information System (INIS)
1995-09-01
Volume two contains calculations for: embankment design--slope stability analysis; embankment design--excavation stability; embankment design--settlement and cover cracking analysis; radon barrier design--statistical analysis of ra-226 concentrations for North Continent and Union Carbide sites; radon barrier design--RAECOM input data; radon barrier design--design thickness; and cover design--frost penetration depth
International Nuclear Information System (INIS)
1995-09-01
Volume four contains calculations for: Borrow areas--site evaluation; temporary facilities--material quantities; embankment quantities--excavation and cover materials; Burro Canyon site excavation quantities--rippable and unrippable materials; site restoration--earthwork quantities and seeding; and bid schedule quantities and material balance
Balankina, E. S.
2016-06-01
Analytical dependences of a volume's properties on the differences between the geometric structures of initial monosystems are obtained for binary systems simulated by a grain medium. The effect of microstructural parameter k (the ratio of volumes of molecules of mixed components) on the concentration behavior of the relative excess molar volume of different types of real binary solutions is analyzed. It is established that the contribution due to differences between the volumes of molecules and coefficients of the packing density of mixed components is ~80-100% for mutual solutions of n-alkanes and ~55-80% of the experimental value of the relative excess molar volume for water solutions of n-alcohols.
Energy Technology Data Exchange (ETDEWEB)
Yoshizaki, T; Imanishi, H; Nishida, K; Yamashita, H; Hiroyasu, H; Kaneda, K [Hiroshima University, Hiroshima (Japan)
1997-10-01
Three dimensional visualization technique based on volume rendering method has been developed in order to translate calculated results of diesel combustion simulation into realistically spray and flame images. This paper presents an overview of diesel combustion model which has been developed at Hiroshima University, a description of the three dimensional visualization technique, and some examples of spray and flame image generated by this visualization technique. 8 refs., 8 figs., 1 tab.
International Nuclear Information System (INIS)
Whitcher, Ralph
2007-01-01
1 - Description of program or function: SACALC2B calculates the average solid angle subtended by a rectangular or circular detector window to a coaxial or non-coaxial rectangular, circular or point source, including where the source and detector planes are not parallel. SACALC C YL calculates the average solid angle subtended by a cylinder to a rectangular or circular source, plane or thick, at any location and orientation. This is needed, for example, in calculating the intrinsic gamma efficiency of a detector such as a GM tube. The program also calculates the number of hits on the cylinder side and on each end, and the average path length through the detector volume (assuming no scattering or absorption). Point sources can be modelled by using a circular source of zero radius. NEA-1688/03: Documentation has been updated (January 2006). 2 - Methods: The program uses a Monte Carlo method to calculate average solid angle for source-detector geometries that are difficult to analyse by analytical methods. The values of solid angle are calculated to accuracies of typically better than 0.1%. The calculated values from the Monte Carlo method agree closely with those produced by polygon approximation and numerical integration by Gardner and Verghese, and others. 3 - Restrictions on the complexity of the problem: The program models a circular or rectangular detector in planes that are not necessarily coaxial, nor parallel. Point sources can be modelled by using a circular source of zero radius. The sources are assumed to be uniformly distributed. NEA-1688/04: In SACALC C YL, to avoid rounding errors, differences less than 1 E-12 are assumed to be zero
Fisicaro, E; Braibanti, A; Lamb, J D; Oscarson, J L
1990-05-01
The relationships between the chemical properties of a system and the partition function algorithm as applied to the description of multiple equilibria in solution are explained. The partition functions ZM, ZA, and ZH are obtained from powers of the binary generating functions Jj = (1 + kappa j gamma j,i[Y])i tau j, where i tau j = p tau j, q tau j, or r tau j represent the maximum number of sites in sites in class j, for Y = M, A, or H, respectively. Each term of the generating function can be considered an element (ij) of a vector Jj and each power of the cooperativity factor gamma ij,i can be considered an element of a diagonal cooperativity matrix gamma j. The vectors Jj are combined in tensor product matrices L tau = (J1) [J2]...[Jj]..., thus representing different receptor-ligand combinations. The partition functions are obtained by summing elements of the tensor matrices. The relationship of the partition functions with the total chemical amounts TM, TA, and TH has been found. The aim is to describe the total chemical amounts TM, TA, and TH as functions of the site affinity constants kappa j and cooperativity coefficients bj. The total amounts are calculated from the sum of elements of tensor matrices Ll. Each set of indices (pj..., qj..., rj...) represents one element of a tensor matrix L tau and defines each term of the summation. Each term corresponds to the concentration of a chemical microspecies. The distinction between microspecies MpjAqjHrj with ligands bound on specific sites and macrospecies MpAqHR corresponding to a chemical stoichiometric composition is shown. The translation of the properties of chemical model schemes into the algorithms for the generation of partition functions is illustrated with reference to a series of examples of gradually increasing complexity. The equilibria examined concern: (1) a unique class of sites; (2) the protonation of a base with two classes of sites; (3) the simultaneous binding of ligand A and proton H to a
International Nuclear Information System (INIS)
1995-09-01
Volume three contains calculations for: site hydrology--rainfall intensity, duration, and frequency relations; site hydrology-- probable maximum precipitation; erosion protection--rock quality evaluation; erosion protection--embankment top and side slope; erosion protection--embankment toe apron; erosion protection-- gradations and layer thicknesses; Union Carbide site--temporary drainage ditch design; Union Carbide site--retention basin sediment volume; Union Carbide site--retention basin sizing; Burro Canyon site temporary drainage--temporary drainage facilities; and Union Carbide site temporary drainage--water balance
Project W-320, 241-C-106 sluicing: Piping calculations. Volume 8
International Nuclear Information System (INIS)
Bailey, J.W.
1998-01-01
This supporting document has been prepared to make the FDNW calculations for Project W-320 readily retrievable. The objective of this calculation is to perform the hydraulic analysis on the slurry line and the supernate line for W-320. This calculation will use the As-Built conditions of the slurry line and the supernate line. Booster Pump Curves vs System Curves shall be generated for the supernate system and the slurry system
Vidot, Kévin; Achir, Nawel; Mertz, Christian; Sinela, André; Rawat, Nadirah; Prades, Alexia; Dangles, Olivier; Fulcrand, Hélène; Dornier, Manuel
2016-05-25
Delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside are the main anthocyanins of Hibiscus sabdariffa calyces, traditionally used to make a bright red beverage by decoction in water. At natural pH, these anthocyanins are mainly in their flavylium form (red) in equilibrium with the quinonoid base (purple) and the hemiketal (colorless). For the first time, their acidity and hydration equilibrium constants were obtained from a pH-jump method followed by UV-vis spectroscopy as a function of temperature from 4 to 37 °C. Equilibrium constant determination was also performed by multivariate curve resolution (MCR). Acidity and hydration constants of cyanidin-3-O-sambubioside at 25 °C were 4.12 × 10(-5) and 7.74 × 10(-4), respectively, and were significantly higher for delphinidin-3-O-sambubioside (4.95 × 10(-5) and 1.21 × 10(-3), respectively). MCR enabled the obtaining of concentration and spectrum of each form but led to overestimated values for the equilibrium constants. However, both methods showed that formations of the quinonoid base and hemiketal were endothermic reactions. Equilibrium constants of anthocyanins in the hibiscus extract showed comparable values as for the isolated anthocyanins.
Directory of Open Access Journals (Sweden)
Guez F.
2006-11-01
Full Text Available La recherche des conditions optimales d'exploitation d'un gisement fissuré repose sur une bonne description de la fissuration. En conséquence il est nécessaire de définir les dimensions et volumes des blocs matriciels en chaque point d'une structure. Or la géométrie du milieu (juxtaposition et formes des blocs est généralement trop complexe pour se prêter au calcul. Aussi, dans une précédente communication, avons-nous dû tourner cette difficulté par un raisonnement sur des moyennes (pendages, azimuts, espacement des fissures qui nous a conduits à un ordre de grandeur des volumes. Cependant un volume moyen ne peut pas rendre compte d'une loi de répartition des volumes des blocs. Or c'est cette répartition qui conditionne le choix d'une ou plusieurs méthodes successives de récupération. Aussi présentons-nous ici une méthode originale de calcul statistique de la loi de distribution des volumes des blocs matriciels, applicable en tout point d'un gisement. La part de gisement concernée par les blocs de volume donné en est déduite. La connaissance générale du phénomène de la fracturation sert de base au modèle. Les observations de subsurface sur la fracturation du gisement en fournissent les données (histogramme d'orientation et d'espacement des fissures.Une application au gisement d'Eschau (Alsace, France est rapportée ici pour illustrer la méthode. The search for optimum production conditions for a fissured reservoir depends on having a good description of the fissure pattern. Hence the sizes and volumes of the matrix blocks must be defined at all points in a structure. However, the geometry of the medium (juxtaposition and shapes of blocks in usually too complex for such computation. This is why, in a previous paper, we got around this problem by reasoning on the bases of averages (clips, azimuths, fissure spacing, and thot led us to an order of magnitude of the volumes. Yet a mean volume cannot be used to explain
Calculation of Airborne Radioactivity Hazard from Machining Volume-Activated Materials
International Nuclear Information System (INIS)
E.T. Marshall; S.O. Schwahn
1997-01-01
When evaluating a task involving the machining of volume-activated materials, accelerator health physicists must consider more than the surface contamination levels of the equipment and containment of loose shavings, dust or filings. Machining operations such as sawing, routing, welding, and grinding conducted on volume-activated material may pose a significant airborne radioactivity hazard to the worker. This paper presents a computer spreadsheet notebook that conservatively estimates the airborne radioactivity levels generated during machining operations performed on volume-activated materials. By knowing (1) the size and type of materials, (2) the dose rate at a given distances, and (3) limited process knowledge, the Derived Air Concentration (DAC) fraction can be estimated. This tool is flexible, taking into consideration that the process knowledge available for the different materials varies. It addresses the two most common geometries: thick plane and circular cylinder. Once the DAC fraction has been estimated, controls can be implemented to mitigate the hazard to the worker
Calculation of airborne radioactivity hazard from machining volume-activated materials
International Nuclear Information System (INIS)
Marshall, E.T.; Schwahn, S.O.
1996-10-01
When evaluating a task involving the machining of volume-activated materials, accelerator health physicists must consider more than the surface contamination levels of the equipment and containment of loose shavings, dust or filings. Machining operations such as sawing, routing, welding, and grinding conducted on volume-activated material may pose a significant airborne radioactivity hazard to the worker. This paper presents a computer spreadsheet notebook that conservatively estimates the airborne radioactivity levels generated during machining operations performed on volume-activated materials. By knowing (1) the size and type of materials, (2) the dose rate at a given distances, and (3) limited process knowledge, the Derived Air Concentration (DAC) fraction can be estimated. This tool is flexible, taking into consideration that the process knowledge available for the different materials varies. It addresses the two most common geometries: thick plane and circular cylinder. Once the DAC fraction has been estimated, controls can be implemented to mitigate the hazard to the worker
Gupta, P. K.; Tessarzik, J. M.; Cziglenyi, L.
1974-01-01
Dynamic properties of a commerical polybutadiene compound were determined at a constant temperature of 32 C by a forced-vibration resonant mass type of apparatus. The constant thermal state of the elastomer was ensured by keeping the ambient temperature constant and by limiting the power dissipation in the specimen. Experiments were performed with both compression and shear specimens at several preloads (nominal strain varying from 0 to 5 percent), and the results are reported in terms of a complex stiffness as a function of frequency. Very weak frequency dependence is observed and a simple power law type of correlation is shown to represent the data well. Variations in the complex stiffness as a function of preload are also found to be small for both compression and shear specimens.
Project W-320, 241-C-106 sluicing HVAC calculations, Volume 4
Energy Technology Data Exchange (ETDEWEB)
Bailey, J.W.
1998-07-30
This supporting document has been prepared to make the FDNW calculations for Project W-320, readily retrievable. The report contains the following design calculations: Cooling load in pump pit 241-AY-102; Pressure relief seal loop design; Process building piping stress analysis; Exhaust skid maximum allowable leakage criteria; and Recirculation heat, N509 duct requirements.
International Nuclear Information System (INIS)
Udovskij, A.L.; Karpushkin, V.N.; Nikishina, E.A.
1991-01-01
Method of non-interacting thermodynamic calculation of state diagram of binary systems contacting p disordered phases with variable composition and q phases with constant composition for (p, q) ≤ 10 case is developed. Determination of all possible solutions of phase equilibrium equations is realized in the method. Certain application examples of computer-realized method of T-x thermodynamic calculation using PC for Cr-W, Ni-W, Ni-Al, Ni-Re binary systems are given
International Nuclear Information System (INIS)
Foos, J.
1999-01-01
This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 1 to 56. (A.L.B.)
International Nuclear Information System (INIS)
Foos, J.
2000-01-01
This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 56 to 68. (A.L.B.)
International Nuclear Information System (INIS)
Foos, J.
1998-01-01
This paper is made of two tables. The first table describes the different particles (bosons and fermions) while the second one gives the nuclear constants of isotopes from the different elements with Z = 1 to 25. (J.S.)
International Nuclear Information System (INIS)
Foos, J.
1999-01-01
This paper is written in two tables. The first one describes the different particles (bosons and fermions). The second one gives the isotopes nuclear constants of the different elements, for Z = 56 to 68. (A.L.B.)
International Nuclear Information System (INIS)
Rojas C, E. L.
2008-01-01
The objective of this study is to investigate the changes observed in the absorbed doses in mammary gland tissue when irradiated with a equipment of high dose rate known as Mammosite and introducing material resources contrary to the tissue that constitutes the mammary gland. The modeling study is performed with the code MCNPX, 2005 version, the equipment and the mammary gland and calculating the absorbed doses in tissue when introduced small volumes of air or calcium in the system. (Author)
Volume fraction calculation in multiphase system such as oil-water-gas using neutron
Energy Technology Data Exchange (ETDEWEB)
Ramos, Robson; Brandao, Luis E.B.; Salgado, Cesar Marques; Pereira, Claudio M.N.A. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mails: robson@ien.gov.br; brandao@ien.gov.br; otero@ien.gov.br; cmnap@ien.gov.br; Schirru, Roberto; Silva, Ademir Xavier da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mails: schirru@lmp.ufrj.br; ademir@con.ufrj.br
2007-07-01
Multi-phase flows are common in diverse industrial sectors and the attainment of the volume fraction of each element that composes the flow system presents difficulties for the engineering process, therefore, to determine them is very important. In this work is presented methodology for determination of volume fractions in annular three-phase flow systems, such as oil-water-gas, based on the use of nuclear techniques and artificial intelligence. Using the principle of the fast-neutron transmission/scattering, come from an isotopic {sup 241}Am-Be source, and two point detectors, is gotten measured that they are influenced by the variations of the volume fractions of each phase present in the flow. An artificial neural network is trained to correlate such measures with the respective volume fractions. In order to get the data for training of the artificial neural network without necessity to carry through experiments, MCNP-X code is used, that simulates computational of the neutrons transport. The methodology is sufficiently advantageous, therefore, allows to develop a measurement system capable to determine the fractions of the phases (oil-water-gas), with proper requirements of each petroliferous installation and with national technology contributing, possibly, with reduction of costs and increase of productivity. (author)
Volume fraction calculation in multiphase system such as oil-water-gas using neutron
International Nuclear Information System (INIS)
Ramos, Robson; Brandao, Luis E.B.; Salgado, Cesar Marques; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da
2007-01-01
Multi-phase flows are common in diverse industrial sectors and the attainment of the volume fraction of each element that composes the flow system presents difficulties for the engineering process, therefore, to determine them is very important. In this work is presented methodology for determination of volume fractions in annular three-phase flow systems, such as oil-water-gas, based on the use of nuclear techniques and artificial intelligence. Using the principle of the fast-neutron transmission/scattering, come from an isotopic 241 Am-Be source, and two point detectors, is gotten measured that they are influenced by the variations of the volume fractions of each phase present in the flow. An artificial neural network is trained to correlate such measures with the respective volume fractions. In order to get the data for training of the artificial neural network without necessity to carry through experiments, MCNP-X code is used, that simulates computational of the neutrons transport. The methodology is sufficiently advantageous, therefore, allows to develop a measurement system capable to determine the fractions of the phases (oil-water-gas), with proper requirements of each petroliferous installation and with national technology contributing, possibly, with reduction of costs and increase of productivity. (author)
Project W-320, 241-C-106 sluicing: Civil/structural calculations. Volume 6
Energy Technology Data Exchange (ETDEWEB)
Bailey, J.W.
1998-07-24
This supporting document has been prepared to make the FDNW calculations for Project W-320 readily retrievable. The purpose of this calculation is to conservatively estimate the weight of equipment and structures being added over Tank 241-C-106 as a result of Project W-320 and combine these weights with the estimated weights of existing structures and equipment as calculated in Attachment 1. The combined weights will be compared to the allowable live load limit to provide a preliminary assessment of loading conditions above Tank 241-C-106.
Project W-320, 241-C-106 sluicing HVAC calculations, Volume 1
International Nuclear Information System (INIS)
Bailey, J.W.
1998-01-01
This supporting document has been prepared to make the FDNW calculations for Project W-320, readily retrievable. The report contains the following calculations: Exhaust airflow sizing for Tank 241-C-106; Equipment sizing and selection recirculation fan; Sizing high efficiency mist eliminator; Sizing electric heating coil; Equipment sizing and selection of recirculation condenser; Chiller skid system sizing and selection; High efficiency metal filter shielding input and flushing frequency; and Exhaust skid stack sizing and fan sizing
Project W-320, 241-C-106 sluicing HVAC calculations, Volume 1
Energy Technology Data Exchange (ETDEWEB)
Bailey, J.W.
1998-08-07
This supporting document has been prepared to make the FDNW calculations for Project W-320, readily retrievable. The report contains the following calculations: Exhaust airflow sizing for Tank 241-C-106; Equipment sizing and selection recirculation fan; Sizing high efficiency mist eliminator; Sizing electric heating coil; Equipment sizing and selection of recirculation condenser; Chiller skid system sizing and selection; High efficiency metal filter shielding input and flushing frequency; and Exhaust skid stack sizing and fan sizing.
Are fundamental constants really constant
International Nuclear Information System (INIS)
Norman, E.B.
1986-01-01
Reasons for suspecting that fundamental constants might change with time are reviewed. Possible consequences of such variations are examined. The present status of experimental tests of these ideas is discussed
DEFF Research Database (Denmark)
Christensen, N. Egede; Feuerbacher, B.
1974-01-01
is obtained from an ad hoc potential based on a Dirac-Slater atomic calculation for the ground-state configuration and with full Slater exchange in the atomic as well as in the crystal potential. The selection of this best potential is justified by comparing the calculated band structure to Fermi...... of states. The present work includes a crude estimate of this surface density of states, which is derived from the bulk band structure by narrowing the d bands according to an effective number of neighbors per surface atom. Estimates of surface relaxation effects are also included.......The electronic energy-band structure of tungsten has been calculated by means of the relativistic-augmented-plane-wave method. A series of mutually related potentials are constructed by varying the electronic configuration and the amount of Slater exchange included. The best band structure...
Project W-320, 241-C-106 sluicing: Piping calculations. Volume 4
International Nuclear Information System (INIS)
Bailey, J.W.
1998-01-01
This supporting document has been prepared to make the FDNW calculations for Project W-320 readily retrievable. The objective of this calculation is to perform the structural analysis of the Pipe Supports designed for Slurry and Supernate transfer pipe lines in order to meet the requirements of applicable ASME codes. The pipe support design loads are obtained from the piping stress calculations W320-27-I-4 and W320-27-I-5. These loads are the total summation of the gravity, pressure, thermal and seismic loads. Since standard typical designs are used for each type of pipe support such as Y-Stop, Guide and Anchors, each type of support is evaluated for the maximum loads to which this type of supports are subjected. These loads are obtained from the AutoPipe analysis and used to check the structural adequacy of these supports
Project W-320, 241-C-106 sluicing: Piping calculations. Volume 4
Energy Technology Data Exchange (ETDEWEB)
Bailey, J.W.
1998-07-24
This supporting document has been prepared to make the FDNW calculations for Project W-320 readily retrievable. The objective of this calculation is to perform the structural analysis of the Pipe Supports designed for Slurry and Supernate transfer pipe lines in order to meet the requirements of applicable ASME codes. The pipe support design loads are obtained from the piping stress calculations W320-27-I-4 and W320-27-I-5. These loads are the total summation of the gravity, pressure, thermal and seismic loads. Since standard typical designs are used for each type of pipe support such as Y-Stop, Guide and Anchors, each type of support is evaluated for the maximum loads to which this type of supports are subjected. These loads are obtained from the AutoPipe analysis and used to check the structural adequacy of these supports.
Project W-320, 241-C-106 sluicing civil/structural calculations, Volume 7
International Nuclear Information System (INIS)
Bailey, J.W.
1998-01-01
The structural skid supporting the Process Building and equipment is designed based on the criteria, codes and standards, referenced in the calculation. The final members and the associated elements satisfy the design requirements of the structure. Revision 1 incorporates vendor data for the weight of the individual equipment components. The updated information does not affect the original conclusion of the calculation, since the overall effect is a reduction in the total weight of the equipment and a nominal relocation of the center of gravity for the skid assembly
Project W-320, 241-C-106 sluicing civil/structural calculations, Volume 7
Energy Technology Data Exchange (ETDEWEB)
Bailey, J.W.
1998-07-24
The structural skid supporting the Process Building and equipment is designed based on the criteria, codes and standards, referenced in the calculation. The final members and the associated elements satisfy the design requirements of the structure. Revision 1 incorporates vendor data for the weight of the individual equipment components. The updated information does not affect the original conclusion of the calculation, since the overall effect is a reduction in the total weight of the equipment and a nominal relocation of the center of gravity for the skid assembly.
Jing, Wei
2014-04-01
The measurement of the two-color line of sight soot and KL factor for NO.2 diesel and jet-A fuels was conducted in an optical constant volume combustion chamber by using a high speed camera under 1000 K ambient temperature and varied oxygen concentration conditions. The ambient conditions were set as follows: four oxygen cases including 10%, 15%, 18% and 21% at 1000 K ambient temperature. KL factor and soot temperature were determined based on the two-color pyrometry technique using two band-pass filters with wavelengths of 650 nm and 550 nm. The results show that low soot temperature is observed in the upstream inner flame along the centerline, which is surrounded by high soot temperature regions, and a high KL factor is found in the same region with a low soot temperature. The results under different times suggest that soot temperature is higher for high O2 conditions during the entire flame development; meanwhile, both integrated KL factor and soot area decrease with the increase of O2 concentration. The two fuels share a similar trend of soot temperature and KL factor, however, diesel flame has a higher soot temperature and a larger high soot temperature area compared to jet-A flame. On the other hand, diesel flame shows a lower soot level during the quasi-steady state with a higher total soot level at the end of the combustion under low O2 conditions. A lower O2 concentration range from 10% to 15% is expected to have the possibility to achieve a simultaneous reduction of soot and NOx in sooting flames under the 1000 K ambient temperature condition. Copyright © 2014 SAE International.
Calculation of complication probability of pion treatment at PSI using dose-volume histograms
International Nuclear Information System (INIS)
Nakagawa, Keiichi; Akanuma, Atsuo; Aoki, Yukimasa
1991-01-01
In the conformation technique a target volume is irradiated uniformly as in conventional radiations, whereas surrounding tissue and organs are nonuniformly irradiated. Clinical data on radiation injuries that accumulate with conventional radiation are not applicable without appropriate compensation. Recently a putative solution of this problem was proposed by Lyman using dose-volume histograms. This histogram reduction method reduces a given dose-volume histogram of an organ to a single step which corresponds to the equivalent complication probability by interpolation. As a result it converts nonuniform radiation into a unique dose to the whole organ which has the equivalent likelihood of radiation injury. This method is based on low LET radiation with conventional fractionation schedules. When it is applied to high LET radiation such as negative pion treatment, a high LET dose should be converted to an equivalent photon dose using an appropriate value of RBE. In the present study the histogram reduction method was applied to actual patients treated by the negative pion conformation technique at the Paul Scherrer Institute. Out of evaluable 90 cases of pelvic tumors, 16 developed grade III-IV bladder injury, and 7 developed grade III-IV rectal injury. The 90 cases were divided into roughly equal groups according to the equivalent doses to the entire bladder and rectum. Complication rates and equivalent doses to the full organs in these groups could be represented by a sigmoid dose-effect relation. When RBE from a pion dose to a photon dose is assumed to be 2.1 for bladder injury, the rates of bladder complications fit best to the theoretical complication curve. When the RBE value was 2.3, the rates of rectal injury fit the theoretical curve best. These values are close to the conversion factor of 2.0 that is used in clinical practice at PSI. This agreement suggests the clinical feasibility of the histogram reduction method in conformation radiotherapy. (author)
Project W-320, 241-C-106 sluicing piping calculations, Volume 7
International Nuclear Information System (INIS)
Bailey, J.W.
1998-01-01
The object of this report is to calculate the hydraulic forces imposed at the sluicer nozzle. This is required by Project W-320 waste retrieval for tank 241-C-106. The method of analysis used is Bernoulli's momentum equation for stead flow
National Research Council Canada - National Science Library
Kotlar, Anthony
1999-01-01
.... These calculations give limiting values for projectile muzzle kinetic energy (KE), assuming complete mixing of the liquid additive and the solid propellant This is a worst-case scenario for the new concept to reduce gun barrel heating...
Project W-320, 241-C-106 sluicing electrical calculations, Volume 2
International Nuclear Information System (INIS)
Bailey, J.W.
1998-01-01
This supporting document has been prepared to make the FDNW calculations for Project W-320, readily retrievable. These calculations are required: To determine the power requirements needed to power electrical heat tracing segments contained within three manufactured insulated tubing assemblies; To verify thermal adequacy of tubing assembly selection by others; To size the heat tracing feeder and branch circuit conductors and conduits; To size protective circuit breaker and fuses; and To accomplish thermal design for two electrical heat tracing segments: One at C-106 tank riser 7 (CCTV) and one at the exhaust hatchway (condensate drain). Contents include: C-Farm electrical heat tracing; Cable ampacity, lighting, conduit fill and voltage drop; and Control circuit sizing and voltage drop analysis for the seismic shutdown system
Johnson, Kenneth L.; White, K. Preston, Jr.
2012-01-01
The NASA Engineering and Safety Center was requested to improve on the Best Practices document produced for the NESC assessment, Verification of Probabilistic Requirements for the Constellation Program, by giving a recommended procedure for using acceptance sampling by variables techniques as an alternative to the potentially resource-intensive acceptance sampling by attributes method given in the document. In this paper, the results of empirical tests intended to assess the accuracy of acceptance sampling plan calculators implemented for six variable distributions are presented.
Calculation of Void Volume Fraction in the Subcooled and Quality Boiling Regions
Energy Technology Data Exchange (ETDEWEB)
Rouhani, S Z; Axelsson, E
1968-10-15
The complex problem of void calculation in the different regions of flow boiling is divided in two parts. The first part includes only the description of the mechanisms and the calculation of the rates of heat transfer for vapour and liquid. It is assumed that heat is removed by vapour generation, heating of the liquid that replaces the detached bubbles, and in some parts, by single phase heat transfer. By considering the rate of vapour condensation in liquid, an equation for the differential changes in the true steam quality throughout the boiling regions is obtained. Integration of this equation yields the vapour weight fraction at any position. The second part of the problem concerns the determination of the void fractions corresponding to the calculated steam qualities. For this purpose we use the derivations of Zuber and Findlay. This model is compared with data from different geometries including small rectangular channels and large rod bundles. The data covered pressures from 19 to 138 bars, heat fluxes from 18 to 120 W/cm{sup 2} with many different subcoolings and mass velocities. The agreement is generally very good.
Calculation of Void Volume Fraction in the Subcooled and Quality Boiling Regions
International Nuclear Information System (INIS)
Rouhani, S.Z.; Axelsson, E.
1968-10-01
The complex problem of void calculation in the different regions of flow boiling is divided in two parts. The first part includes only the description of the mechanisms and the calculation of the rates of heat transfer for vapour and liquid. It is assumed that heat is removed by vapour generation, heating of the liquid that replaces the detached bubbles, and in some parts, by single phase heat transfer. By considering the rate of vapour condensation in liquid, an equation for the differential changes in the true steam quality throughout the boiling regions is obtained. Integration of this equation yields the vapour weight fraction at any position. The second part of the problem concerns the determination of the void fractions corresponding to the calculated steam qualities. For this purpose we use the derivations of Zuber and Findlay. This model is compared with data from different geometries including small rectangular channels and large rod bundles. The data covered pressures from 19 to 138 bars, heat fluxes from 18 to 120 W/cm 2 with many different subcoolings and mass velocities. The agreement is generally very good
Weather data for simplified energy calculation methods. Volume IV. United States: WYEC data
Energy Technology Data Exchange (ETDEWEB)
Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.
1984-08-01
The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 23 cities using Weather Year for Energy Calculations (WYEC) source weather data. Considerable overlap is present in cities (21) covered by both the TRY and WYEC data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.
International Nuclear Information System (INIS)
Borg, Michael; Hansen, Anders Melchior; Bredmose, Henrik
2016-01-01
Designing floating substructures for the next generation of 10MW and larger wind turbines has introduced new challenges in capturing relevant physical effects in dynamic simulation tools. In achieving technically and economically optimal floating substructures, structural flexibility may increase to the extent that it becomes relevant to include in addition to the standard rigid body substructure modes which are typically described through linear radiation-diffraction theory. This paper describes a method for the inclusion of substructural flexibility in aero-hydro-servo-elastic dynamic simulations for large-volume substructures, including wave-structure interactions, to form the basis of deriving sectional loads and stresses within the substructure. The method is applied to a case study to illustrate the implementation and relevance. It is found that the flexible mode is significantly excited in an extreme event, indicating an increase in predicted substructure internal loads. (paper)
An assessment of unstructured grid finite volume schemes for cold gas hypersonic flow calculations
Directory of Open Access Journals (Sweden)
João Luiz F. Azevedo
2009-06-01
Full Text Available A comparison of five different spatial discretization schemes is performed considering a typical high speed flow application. Flowfields are simulated using the 2-D Euler equations, discretized in a cell-centered finite volume procedure on unstructured triangular meshes. The algorithms studied include a central difference-type scheme, and 1st- and 2nd-order van Leer and Liou flux-vector splitting schemes. These methods are implemented in an efficient, edge-based, unstructured grid procedure which allows for adaptive mesh refinement based on flow property gradients. Details of the unstructured grid implementation of the methods are presented together with a discussion of the data structure and of the adaptive refinement strategy. The application of interest is the cold gas flow through a typical hypersonic inlet. Results for different entrance Mach numbers and mesh topologies are discussed in order to assess the comparative performance of the various spatial discretization schemes.
International Nuclear Information System (INIS)
Vertes, P.
1981-05-01
A new, completely rewritten version of the FEDGROUP program system is presented in this report. The formulae and the algorithm underlying the calculation are revised. The FEDGROUP-3 is able to calculate group averaged infinite diluted and screened cross-sections, elastic and inelastic transfer matrices, point-wise cross-section sets from evaluated data in ENDF/B, KEDAK and UKNDL format. The program system is written mainly in FORTRAN-IV of IBM-OS but it can be adapted relatively easily to other type of computers. (author)
International Nuclear Information System (INIS)
Buiklinskij, V.D.; Kuznetsova, S.L.; Kostyrina, T.V.; Panyushkina, V.T.
1991-01-01
Lanthanide shifting reagent (LSR) on the basis of β-diketone of asymmetric structure, containing heteroatom-oxygen in fluorinated radical, has been synthesized. Adduct formation of LSR synthesized with 4-picoline has been studied by the method of NMR spectroscopy. The composition of the adduct formed, being 1:2, is determined. Stability constant of the adduct considered is calculated by previously suggested method, which consists in taking into account of equilibrium concentrations of the substrate in two experiments. Possibilities of computer graphics for the evaluation of paramters of the mathematical model suggested are demonstrated. The values of stability stepped constants of the adduct are calculated: lg K 1 =3.4±0.1; lg K 2 =2.0±0.1
Weather data for simplified energy calculation methods. Volume II. Middle United States: TRY data
Energy Technology Data Exchange (ETDEWEB)
Olsen, A.R.; Moreno, S.; Deringer, J.; Watson, C.R.
1984-08-01
The objective of this report is to provide a source of weather data for direct use with a number of simplified energy calculation methods available today. Complete weather data for a number of cities in the United States are provided for use in the following methods: degree hour, modified degree hour, bin, modified bin, and variable degree day. This report contains sets of weather data for 22 cities in the continental United States using Test Reference Year (TRY) source weather data. The weather data at each city has been summarized in a number of ways to provide differing levels of detail necessary for alternative simplified energy calculation methods. Weather variables summarized include dry bulb and wet bulb temperature, percent relative humidity, humidity ratio, wind speed, percent possible sunshine, percent diffuse solar radiation, total solar radiation on horizontal and vertical surfaces, and solar heat gain through standard DSA glass. Monthly and annual summaries, in some cases by time of day, are available. These summaries are produced in a series of nine computer generated tables.
Benedek, Judit; Papp, Gábor; Kalmár, János
2018-04-01
Beyond rectangular prism polyhedron, as a discrete volume element, can also be used to model the density distribution inside 3D geological structures. The calculation of the closed formulae given for the gravitational potential and its higher-order derivatives, however, needs twice more runtime than that of the rectangular prism computations. Although the more detailed the better principle is generally accepted it is basically true only for errorless data. As soon as errors are present any forward gravitational calculation from the model is only a possible realization of the true force field on the significance level determined by the errors. So if one really considers the reliability of input data used in the calculations then sometimes the "less" can be equivalent to the "more" in statistical sense. As a consequence the processing time of the related complex formulae can be significantly reduced by the optimization of the number of volume elements based on the accuracy estimates of the input data. New algorithms are proposed to minimize the number of model elements defined both in local and in global coordinate systems. Common gravity field modelling programs generate optimized models for every computation points ( dynamic approach), whereas the static approach provides only one optimized model for all. Based on the static approach two different algorithms were developed. The grid-based algorithm starts with the maximum resolution polyhedral model defined by 3-3 points of each grid cell and generates a new polyhedral surface defined by points selected from the grid. The other algorithm is more general; it works also for irregularly distributed data (scattered points) connected by triangulation. Beyond the description of the optimization schemes some applications of these algorithms in regional and local gravity field modelling are presented too. The efficiency of the static approaches may provide even more than 90% reduction in computation time in favourable
Rusakov, Yury Yu; Rusakova, Irina L; Krivdin, Leonid B
2014-05-01
Four-component relativistic calculations of (77)Se-(13)C spin-spin coupling constants have been performed in the series of selenium heterocycles and their parent open-chain selenides. It has been found that relativistic effects play an essential role in the selenium-carbon coupling mechanism and could result in a contribution of as much as 15-25% of the total values of the one-bond selenium-carbon spin-spin coupling constants. In the overall contribution of the relativistic effects to the total values of (1)J(Se,C), the scalar relativistic corrections (negative in sign) by far dominate over the spin-orbit ones (positive in sign), the latter being of less than 5%, as compared to the former (ca 20%). A combination of nonrelativistic second-order polarization propagator approach (CC2) with the four-component relativistic density functional theory scheme is recommended as a versatile tool for the calculation of (1)J(Se,C). Solvent effects in the values of (1)J(Se,C) calculated within the polarizable continuum model for the solvents with different dielectric constants (ε 2.2-78.4) are next to negligible decreasing negative (1)J(Se,C) in absolute value by only about 1 Hz. The use of the locally dense basis set approach applied herewith for the calculation of (77)Se-(13)C spin-spin coupling constants is fully justified resulting in a dramatic decrease in computational cost with only 0.1-0.2-Hz loss of accuracy. Copyright © 2014 John Wiley & Sons, Ltd.
DEFF Research Database (Denmark)
Zarycz, M. Natalia C.; Provasi, Patricio F.; Sauer, Stephan P. A.
2015-01-01
of the Polarization Propagator (IPPP-CLOPPA) approach to analyzing SSCCs in terms of localized orbitals. As a test set we have studied the nine simple compounds, CH4, NH3, H2O, SiH4, PH3, SH2, C2H2, C2H4 and C2H6. The excited (pseudo)states were obtained from TD-DFT calculations with the B3LYP exchange...
International Nuclear Information System (INIS)
Cullen, D.E.; Howerton, R.J.; MacGregor, M.H.; Perkins, S.T.
1976-01-01
This report (Vol. 8) presents graphs of supplemental neutron-induced cross sections in the Experimental Cross Section Information Library (ECSIL) as of July 4, 1976. It consists of interactions where more than one data set is needed to show cross-section behavior. In contrast, Vol. 7 of this UCRL-50400 series consists primarily of interactions where a single data set contains enough points to show cross-section behavior. In Vol. 7 can be found the total, elastic, capture, and fission cross sections (along with the parameters anti ν, α, and eta). Volume 8 contains all other reactions. Data are plotted with associated cross-section error bars (when given) and compared with the Evaluated Nuclear Data Library (ENDL) as of July 4, 1976. The plots are arranged in ascending order of atomic number (Z) and atomic weight (A). Part A contains the plots for Z = 1 to 35; Part B contains the plots for Z greater than 35
Directory of Open Access Journals (Sweden)
Nelson H. T. Lemes
2010-01-01
Full Text Available Analytical solutions of a cubic equation with real coefficients are established using the Cardano method. The method is first applied to simple third order equation. Calculation of volume in the van der Waals equation of state is afterwards established. These results are exemplified to calculate the volumes below and above critical temperatures. Analytical and numerical values for the compressibility factor are presented as a function of the pressure. As a final example, coexistence volumes in the liquid-vapor equilibrium are calculated. The Cardano approach is very simple to apply, requiring only elementary operations, indicating an attractive method to be used in teaching elementary thermodynamics.
Potential constants and centrifugal distortion constants of octahedral hexafluoride molecules
Energy Technology Data Exchange (ETDEWEB)
Manivannan, G [Government Thirumagal Mill' s Coll., Gudiyattam, Tamil Nadu (India)
1981-04-01
The kinetic constants method outlined by Thirugnanasambandham (1964) based on Wilson's (1955) group theory has been adapted in evaluating the potential constants for SF/sub 6/, SeF/sub 6/, WF/sub 6/, IrF/sub 6/, UF/sub 6/, NpF/sub 6/, and PuF/sub 6/ using the experimentally observed vibrational frequency data. These constants are used to calculate the centrifugal distortion constants for the first time.
Volume 1: Calculating potential to emit releases and doses for FEMP's and NOCs; FINAL
International Nuclear Information System (INIS)
HILL, J.S.
1999-01-01
The purpose of this document is to provide Hanford Site facilities a handbook for estimating potential emissions and the subsequent offsite doses. General guidelines and information are provided to assist personnel in estimating emissions for use with U.S. Department of Energy (DOE) facility effluent monitoring plans (FEMPs) and regulatory notices of construction (NOCs), per 40 Code of Federal Regulations (CFR) Part 61, Subpart H, and Washington Administrative Code (WAC) Chapter 246-247 requirements. This document replaces Unit Dose Calculation Methods and Summary of Facility Effluent Monitoring Plan Determinations (WHC-EP-0498). Meteorological data from 1983 through 1996, 13-year data set, was used to develop the unit dose factors provided by this document, with the exception of two meteorological stations. Meteorological stations 23 and 24, located at Gable Mountain and the 100-F Area, only have data from 1986 through 1996, 10-year data set. The scope of this document includes the following: Estimating emissions and resulting effective dose equivalents (EDE) to a facility's nearest offsite receptor (NOR) for use with NOCs under 40 CFR Part 61, Subpart H, requirements Estimating emissions and resulting EDEs to a facility's or emission unit's NOR for use with NOCs under the WAC Chapter 246-247 requirements Estimating emissions and resulting EDEs to a facility's or emission unit's NOR for use with FEMPs and FEMP determinations under DOE Orders 5400.1 and 5400.5 requirements
Theilig, Dorothea; Doellinger, Felix; Poellinger, Alexander; Schreiter, Vera; Neumann, Konrad; Hubner, Ralf-Harto
2017-01-01
The degree of interlobar emphysema heterogeneity is thought to play an important role in the outcome of endoscopic lung volume reduction (ELVR) therapy of patients with advanced COPD. There are multiple ways one could possibly define interlobar emphysema heterogeneity, and there is no standardized definition. The aim of this study was to derive a formula for calculating an interlobar emphysema heterogeneity index (HI) when evaluating a patient for ELVR. Furthermore, an attempt was made to identify a threshold for relevant interlobar emphysema heterogeneity with regard to ELVR. We retrospectively analyzed 50 patients who had undergone technically successful ELVR with placement of one-way valves at our institution and had received lung function tests and computed tomography scans before and after treatment. Predictive accuracy of the different methods for HI calculation was assessed with receiver-operating characteristic curve analysis, assuming a minimum difference in forced expiratory volume in 1 second of 100 mL to indicate a clinically important change. The HI defined as emphysema score of the targeted lobe (TL) minus emphysema score of the ipsilateral nontargeted lobe disregarding the middle lobe yielded the best predicative accuracy (AUC =0.73, P =0.008). The HI defined as emphysema score of the TL minus emphysema score of the lung without the TL showed a similarly good predictive accuracy (AUC =0.72, P =0.009). Subgroup analysis suggests that the impact of interlobar emphysema heterogeneity is of greater importance in patients with upper lobe predominant emphysema than in patients with lower lobe predominant emphysema. This study reveals the most appropriate ways of calculating an interlobar emphysema heterogeneity with regard to ELVR.
Nordström, Jonny; Kero, Tanja; Harms, Hendrik Johannes; Widström, Charles; Flachskampf, Frank A; Sörensen, Jens; Lubberink, Mark
2017-11-14
Quantitative measurement of myocardial blood flow (MBF) is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD). 15 O-water positron emission tomography (PET) is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV) volumes and ejection fraction (EF) is not possible from standard 15 O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B ) 15 O-water images and from first pass (FP) images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated 15 O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV) and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI. Using V B images, high correlations between PET and MRI ESV (r = 0.89, p 0.86, p dynamic 15 O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.
Directory of Open Access Journals (Sweden)
Theilig D
2017-06-01
Full Text Available Dorothea Theilig,1 Felix Doellinger,1 Alexander Poellinger,1 Vera Schreiter,1 Konrad Neumann,2 Ralf-Harto Hubner31Department of Radiology, Charité Campus Virchow Klinikum, Charité, Universitätsmedizin Berlin, Berlin, Germany; 2Institute of Biometrics and Clinical Epidemiology, Charité Campus Benjamin Franklin, Charité, Universitätsmedizin Berlin, Berlin, Germany; 3Department of Pneumology, Charité Campus Virchow Klinikum, Charité, Universitätsmedizin Berlin, Berlin, GermanyBackground: The degree of interlobar emphysema heterogeneity is thought to play an important role in the outcome of endoscopic lung volume reduction (ELVR therapy of patients with advanced COPD. There are multiple ways one could possibly define interlobar emphysema heterogeneity, and there is no standardized definition.Purpose: The aim of this study was to derive a formula for calculating an interlobar emphysema heterogeneity index (HI when evaluating a patient for ELVR. Furthermore, an attempt was made to identify a threshold for relevant interlobar emphysema heterogeneity with regard to ELVR.Patients and methods: We retrospectively analyzed 50 patients who had undergone technically successful ELVR with placement of one-way valves at our institution and had received lung function tests and computed tomography scans before and after treatment. Predictive accuracy of the different methods for HI calculation was assessed with receiver-operating characteristic curve analysis, assuming a minimum difference in forced expiratory volume in 1 second of 100 mL to indicate a clinically important change.Results: The HI defined as emphysema score of the targeted lobe (TL minus emphysema score of the ipsilateral nontargeted lobe disregarding the middle lobe yielded the best predicative accuracy (AUC =0.73, P=0.008. The HI defined as emphysema score of the TL minus emphysema score of the lung without the TL showed a similarly good predictive accuracy (AUC =0.72, P=0.009. Subgroup
Wang, K.; Zhang, C. Y.; Jönsson, P.; Si, R.; Zhao, X. H.; Chen, Z. B.; Guo, X. L.; Chen, C. Y.; Yan, J.
2018-03-01
Employing two state-of-the-art methods, multiconfiguration Dirac-Hartree-Fock and second-order many-body perturbation theory, highly accurate calculations are performed for the lowest 272 fine-structure levels arising from the 2s22p3, 2s2p4, 2p5, 2s22p23l (l = s , p , d), 2s2p33l (l = s , p , d), and 2p43l (l = s , p , d) configurations in nitrogen-like Ge XXVI. Complete and consistent atomic data, including excitation energies, lifetimes, wavelengths, hyperfine structures, Landé gJ-factors, and E1, E2, M1, M2 line strengths, oscillator strengths, and transition rates among these 272 levels are provided. Comparisons are made between the present two data sets, as well as with other available experimental and theoretical values. The present data are accurate enough for identification and deblending of emission lines involving the n = 3 levels, and are also useful for modeling and diagnosing fusion plasmas.
International Nuclear Information System (INIS)
Lougovski, A; Hofheinz, F; Maus, J; Schramm, G; Will, E; Hoff, J van den
2014-01-01
The aim of this study is the evaluation of on-the-fly volume of intersection computation for system’s geometry modelling in 3D PET image reconstruction. For this purpose we propose a simple geometrical model in which the cubic image voxels on the given Cartesian grid are approximated with spheres and the rectangular tubes of response (ToRs) are approximated with cylinders. The model was integrated into a fully 3D list-mode PET reconstruction for performance evaluation. In our model the volume of intersection between a voxel and the ToR is only a function of the impact parameter (the distance between voxel centre to ToR axis) but is independent of the relative orientation of voxel and ToR. This substantially reduces the computational complexity of the system matrix calculation. Based on phantom measurements it was determined that adjusting the diameters of the spherical voxel size and the ToR in such a way that the actual voxel and ToR volumes are conserved leads to the best compromise between high spatial resolution, low noise, and suppression of Gibbs artefacts in the reconstructed images. Phantom as well as clinical datasets from two different PET systems (Siemens ECAT HR + and Philips Ingenuity-TF PET/MR) were processed using the developed and the respective vendor-provided (line of intersection related) reconstruction algorithms. A comparison of the reconstructed images demonstrated very good performance of the new approach. The evaluation showed the respective vendor-provided reconstruction algorithms to possess 34–41% lower resolution compared to the developed one while exhibiting comparable noise levels. Contrary to explicit point spread function modelling our model has a simple straight-forward implementation and it should be easy to integrate into existing reconstruction software, making it competitive to other existing resolution recovery techniques. (paper)
Farrance, Ian; Frenkel, Robert
2014-01-01
The Guide to the Expression of Uncertainty in Measurement (usually referred to as the GUM) provides the basic framework for evaluating uncertainty in measurement. The GUM however does not always provide clearly identifiable procedures suitable for medical laboratory applications, particularly when internal quality control (IQC) is used to derive most of the uncertainty estimates. The GUM modelling approach requires advanced mathematical skills for many of its procedures, but Monte Carlo simulation (MCS) can be used as an alternative for many medical laboratory applications. In particular, calculations for determining how uncertainties in the input quantities to a functional relationship propagate through to the output can be accomplished using a readily available spreadsheet such as Microsoft Excel. The MCS procedure uses algorithmically generated pseudo-random numbers which are then forced to follow a prescribed probability distribution. When IQC data provide the uncertainty estimates the normal (Gaussian) distribution is generally considered appropriate, but MCS is by no means restricted to this particular case. With input variations simulated by random numbers, the functional relationship then provides the corresponding variations in the output in a manner which also provides its probability distribution. The MCS procedure thus provides output uncertainty estimates without the need for the differential equations associated with GUM modelling. The aim of this article is to demonstrate the ease with which Microsoft Excel (or a similar spreadsheet) can be used to provide an uncertainty estimate for measurands derived through a functional relationship. In addition, we also consider the relatively common situation where an empirically derived formula includes one or more ‘constants’, each of which has an empirically derived numerical value. Such empirically derived ‘constants’ must also have associated uncertainties which propagate through the functional
A first-principles approach to finite temperature elastic constants
Energy Technology Data Exchange (ETDEWEB)
Wang, Y; Wang, J J; Zhang, H; Manga, V R; Shang, S L; Chen, L-Q; Liu, Z-K [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802 (United States)
2010-06-09
A first-principles approach to calculating the elastic stiffness coefficients at finite temperatures was proposed. It is based on the assumption that the temperature dependence of elastic stiffness coefficients mainly results from volume change as a function of temperature; it combines the first-principles calculations of elastic constants at 0 K and the first-principles phonon theory of thermal expansion. Its applications to elastic constants of Al, Cu, Ni, Mo, Ta, NiAl, and Ni{sub 3}Al from 0 K up to their respective melting points show excellent agreement between the predicted values and existing experimental measurements.
A first-principles approach to finite temperature elastic constants
International Nuclear Information System (INIS)
Wang, Y; Wang, J J; Zhang, H; Manga, V R; Shang, S L; Chen, L-Q; Liu, Z-K
2010-01-01
A first-principles approach to calculating the elastic stiffness coefficients at finite temperatures was proposed. It is based on the assumption that the temperature dependence of elastic stiffness coefficients mainly results from volume change as a function of temperature; it combines the first-principles calculations of elastic constants at 0 K and the first-principles phonon theory of thermal expansion. Its applications to elastic constants of Al, Cu, Ni, Mo, Ta, NiAl, and Ni 3 Al from 0 K up to their respective melting points show excellent agreement between the predicted values and existing experimental measurements.
Garin, Etienne; Rolland, Yan; Lenoir, Laurence; Pracht, Marc; Mesbah, Habiba; Porée, Philippe; Laffont, Sophie; Clement, Bruno; Raoul, Jean-Luc; Boucher, Eveline
2011-01-01
Objectives. The aim of this study was to assess the effectiveness of SPECT/CT for volume measurements and to report a case illustrating the major impact of SPECT/CT in calculating the vascularized liver volume and dosimetry prior to injecting radiolabelled yttrium-90 microspheres (Therasphere). Materials and Methods. This was a phantom study, involving volume measurements carried out by two operators using SPECT and SPECT/CT images. The percentage of error for each method was calculated, and interobserver reproducibility was evaluated. A treatment using Therasphere was planned in a patient with three hepatic arteries, and the quantitative analysis of SPECT/CT for this patient is provided. Results. SPECT/CT volume measurements proved to be accurate (mean error Therasphere used. Conclusions. MAA SPECT/CT is accurate for vascularized liver volume measurements, providing a valuable contribution to the therapeutic planning of patients with complex hepatic vascularization.
Garin, Etienne; Rolland, Yan; Lenoir, Laurence; Pracht, Marc; Mesbah, Habiba; Porée, Philippe; Laffont, Sophie; Clement, Bruno; Raoul, Jean-Luc; Boucher, Eveline
2011-01-01
Objectives. The aim of this study was to assess the effectiveness of SPECT/CT for volume measurements and to report a case illustrating the major impact of SPECT/CT in calculating the vascularized liver volume and dosimetry prior to injecting radiolabelled yttrium-90 microspheres (Therasphere). Materials and Methods. This was a phantom study, involving volume measurements carried out by two operators using SPECT and SPECT/CT images. The percentage of error for each method was calculated, and interobserver reproducibility was evaluated. A treatment using Therasphere was planned in a patient with three hepatic arteries, and the quantitative analysis of SPECT/CT for this patient is provided. Results. SPECT/CT volume measurements proved to be accurate (mean error Therasphere used. Conclusions. MAA SPECT/CT is accurate for vascularized liver volume measurements, providing a valuable contribution to the therapeutic planning of patients with complex hepatic vascularization. PMID:21822489
Radiographic constant exposure technique
DEFF Research Database (Denmark)
Domanus, Joseph Czeslaw
1985-01-01
The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...
Directory of Open Access Journals (Sweden)
Jonny Nordström
2017-11-01
Full Text Available Abstract Background Quantitative measurement of myocardial blood flow (MBF is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD. 15O-water positron emission tomography (PET is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV volumes and ejection fraction (EF is not possible from standard 15O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B 15O-water images and from first pass (FP images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated 15O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV, end-diastolic volume (EDV, stroke volume (SV and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI. Results Using V B images, high correlations between PET and MRI ESV (r = 0.89, p 0.86, p < 0.001. Conclusion Calculation of LV volumes and LVEF from dynamic 15O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.
International Nuclear Information System (INIS)
Dubovik, V.M.; Zenkin, S.V.
1983-01-01
On the basis of the total effective Hamiltonian of the parity nonconserving (PNC) hadron-hadron interactions found within the standard model SU(2)sUb(L)XU(1)xSU(3)sub(c) in all orders of the leading logarithms allowing for the difference of quark mass scales (msub(c)>>msub(u, d, s)) the PNC πNN vertex generating the long-range part of the PNC nuclear forces is considered. The origin and the methods of calculation of various contributions to this vertex with a special attention to possible artifacts of these methods is anatyzed. Within the self-consistence calculational framework partly including the MIT bag model the total value of the constant hsub(π) determining the PNC πNN vertex is evaluated. Value of hsub(π) (approximately 1.3x10 -7 ) is 2-4 times as small as previous estimates and does not contradict the experimental data
Ouk, Chanda-Malis; Zvereva-Loëte, Natalia; Scribano, Yohann; Bussery-Honvault, Béatrice
2012-10-30
Multireference single and double configuration interaction (MRCI) calculations including Davidson (+Q) or Pople (+P) corrections have been conducted in this work for the reactants, products, and extrema of the doublet ground state potential energy surface involved in the N((2)D) + CH(4) reaction. Such highly correlated ab initio calculations are then compared with previous PMP4, CCSD(T), W1, and DFT/B3LYP studies. Large relative differences are observed in particular for the transition state in the entrance channel resolving the disagreement between previous ab initio calculations. We confirm the existence of a small but positive potential barrier (3.86 ± 0.84 kJ mol(-1) (MR-AQCC) and 3.89 kJ mol(-1) (MRCI+P)) in the entrance channel of the title reaction. The correlation is seen to change significantly the energetic position of the two minima and five saddle points of this system together with the dissociation channels but not their relative order. The influence of the electronic correlation into the energetic of the system is clearly demonstrated by the thermal rate constant evaluation and it temperature dependance by means of the transition state theory. Indeed, only MRCI values are able to reproduce the experimental rate constant of the title reaction and its behavior with temperature. Similarly, product branching ratios, evaluated by means of unimolecular RRKM theory, confirm the NH production of Umemoto et al., whereas previous works based on less accurate ab initio calculations failed. We confirm the previous findings that the N((2)D) + CH(4) reaction proceeds via an insertion-dissociation mechanism and that the dominant product channels are CH(2)NH + H and CH(3) + NH. Copyright © 2012 Wiley Periodicals, Inc.
International Nuclear Information System (INIS)
Karlo, C.; Reiner, C.S.; Stolzmann, P.; Breitenstein, S.; Marincek, B.; Weishaupt, D.; Frauenfelder, T.
2010-01-01
Objective: To compare virtual volume to intraoperative volume and weight measurements of resected liver specimen and calculate appropriate conversion factors to reach better correlation. Methods: Preoperative (CT-group, n = 30; MRI-group, n = 30) and postoperative MRI (n = 60) imaging was performed in 60 patients undergoing partial liver resection. Intraoperative volume and weight of the resected liver specimen was measured. Virtual volume measurements were performed by two readers (R1,R2) using dedicated software. Conversion factors were calculated. Results: Mean intraoperative resection weight/volume: CT: 855 g/852 mL; MRI: 872 g/860 mL. Virtual resection volume: CT: 960 mL(R1), 982 mL(R2); MRI: 1112 mL(R1), 1115 mL(R2). Strong positive correlation for both readers between intraoperative and virtual measurements, mean of both readers: CT: R = 0.88(volume), R = 0.89(weight); MRI: R = 0.95(volume), R = 0.92(weight). Conversion factors: 0.85(CT), 0.78(MRI). Conclusion: CT- or MRI-based volumetry of resected liver specimen is accurate and recommended for preoperative planning. A conversion of the result is necessary to improve intraoperative and virtual measurement correlation. We found 0.85 for CT- and 0.78 for MRI-based volumetry the most appropriate conversion factors.
International Nuclear Information System (INIS)
Simon, O.; Bergner, H.; Wolf, E.
1978-01-01
Male wistar rats (100 p body weight) were infused into the tail vein with 14 C-leucine and 14 C-lysine simultaneously for 0.5; 1.0; 2.0; 3.0; 4.5; 6.0 and 7.0 hours. At the end of the infusion the specific radioactivity was determined of the free leucine and lysine in the blood plasma, liver, M. gastrocnemius, small intestine, and colon as well as of the protein-bound leucine and lysine. In all the tissues tested the specific radioactivity of the free amino acids attained a plateau during the 6-hour and 7-hour infusions. The rate constants for the increase were calculated for each organ tested. The two amino acids used are suitable for calculating the fractional rate of protein synthesis in tissues. The values of the fractional rate of protein synthesis calculated on the basis of the 6-hour and 7-hour infusions were: 54+-7.7%/day for the liver, 9.4+-1.2%/day for the muscles, 89+-12.2%/day for the small intestine, and 42+-5.9%/day for the colon. The simultaneous application of two tracer amino acids is recommendable for estimating the precursor pool of the protein synthesis and the more accurate calculation of the rate of protein synthesis. (author)
International Nuclear Information System (INIS)
Gomez T, A. M.; Xolocostli M, V.; Lopez M, R.; Filio L, C.; Royl, P.
2014-10-01
In 2012 was modeled of primary and secondary container of the nuclear power plant of Laguna Verde (NPP-L V) for the CFD Gas-Flow code. These models were used to calculate hydrogen volume concentrations run release the reactor building in case of a severe accident. The results showed that the venting would produce detonation conditions in the venting level (level 33) and flammability at ground level of reload. One of the solutions to avoid reaching critical concentrations (flammable or detonable) inside the reactor building and thus safeguard the contentions is to make a rigid venting. The rigid vent is a pipe connected to the primary container could go to the level 33 of the secondary container and style fireplace climb to the top of the reactor building. The analysis of hydrogen transport inside the vent pipe can be influenced by various environmental criteria and factors vent, so a logical consequence of the 2012 analysis is the analysis of the gases transport within said pipe to define vent ideal conditions. For these evaluations the vent pipe was modeled with a fine mesh of 32 radial interior nodes and a coarse mesh of 4 radial interior nodes. With three-dimensional models were realized calculations that allow observing the influence of heat transfer in the long term, i.e. a complete analysis of exhaust (approx. 700 seconds). However, the most interesting results focus on the first milliseconds, when the H 2 coming from the atmosphere of the primary container faces the air in the vent pipe. These first milliseconds besides allowing evaluating the detonation criteria in great detail in the different tubular sections similarly allow evaluating the pressure wave that occurs in the pipe and that at some point slows to the fluid on the last tubular section and could produce a detonation inside the pipe. Results are presented for venting fixed conditions, showing possible detonations into the pipe. (Author)
International Nuclear Information System (INIS)
Horas, Jorge A; Olguin, Osvaldo R; Rizzotto, Marcos G
2005-01-01
We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic core and a viable rim which is a caricature of a real tumour is constructed. The model is embedded in a two-compartment linear-quadratic (LQ) model, assuming a mixed bivariated Gaussian distribution to attain the radiosensitivity parameters. Ergodicity, i.e., the equivalence between ensemble and volumetric averages is used to obtain the overall radiosensitivities for the two compartments. We obtain expressions for the overall radiosensitivity parameters resulting from the use of both a linear and a nonlinear dependence of the local radiosensitivity with position. The model's results are compared with experimental data of surviving fraction (SF) for multicellular spheroids of different sizes. We make one fit using only the smallest spheroid data and we are able to predict the SF for the larger spheroids. These predictions are acceptable particularly using bounded sensitivities. We conclude with the importance of taking into account the contribution of clonogenic hypoxic cells to radiosensitivity and with the convenience of using bounded local sensitivities to predict overall radiosensitivity parameters
International Nuclear Information System (INIS)
Stebler, M.; Nielson, R.M.; Siems, W.F.; Hunt, J.P.; Dodgen, H.W.; Wherland, H.W.
1988-01-01
The rate of electron self-exchange of Mn(CNC(CH 3 ) 3 ) 6 +/2+ and Mn(CNC 6 H 11 ) 6 +/2+ as the BF 4 - salts has been measured by 55 Mn NMR line broadening as a function of pressure, temperature, and concentration in acetonitrile, bromobenzene, benzonitrile, acetone, diethyl ketone, methanol, ethanol, methylene chloride, and trimethyl phosphate, and various binary mixtures of methylene chloride, bromobenzene, and acetonitrile. The values of ΔV double dagger obtained are negative and cover a range of ca. 12 cm 3 /mol, which is limited by ion pairing in the solvents of lower dielectric constant. The variation of the ambient pressure rate constant with solvent is qualitatively different for Mn(CNC(CH 3 ) 3 ) 6 +/2+ reaction than was observed for the Mn(CNC 6 H 11 ) 6 +/2+ reaction. This is taken as further evidence for a significant influence of rather subtle differences in solvation on the molecular level that are not approximated by dielectric continuum models. 30 references, 3 tables
International Nuclear Information System (INIS)
Koponen, B.L.; Hampel, V.E.
1982-01-01
This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains-in chronological order-the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41
Energy Technology Data Exchange (ETDEWEB)
Koponen, B.L.; Hampel, V.E.
1982-10-21
This compilation contains 688 complete summaries of papers on nuclear criticality safety as presented at meetings of the American Nuclear Society (ANS). The selected papers contain criticality parameters for fissile materials derived from experiments and calculations, as well as criticality safety analyses for fissile material processing, transport, and storage. The compilation was developed as a component of the Nuclear Criticality Information System (NCIS) now under development at the Lawrence Livermore National Laboratory. The compilation is presented in two volumes: Volume 1 contains a directory to the ANS Transaction volume and page number where each summary was originally published, the author concordance, and the subject concordance derived from the keyphrases in titles. Volume 2 contains-in chronological order-the full-text summaries, reproduced here by permission of the American Nuclear Society from their Transactions, volumes 1-41.
Directory of Open Access Journals (Sweden)
Ahmed Z. Nooh
2017-09-01
The gamma ray log data resolution is considerably lower than the FMI log to reflect accurate lithology changes in thinly bedded reservoirs. It has been found afterthought some calibrations and corrections on the FMI resistivity log, the new processed log is used for clay volume and net to gross calculation of the reservoir, indicating the potential of this log for analysis of thin beds. A comparison between VNG-NERGE, NORTH SEA WELL, NERWING and LAGIA-8, LAGIA, EGYPT indicates the calculation for shale volume at different intervals using FMI tools.
Dorofeeva, Olga V; Vogt, Natalja; Vogt, Jürgen; Popik, Mikhail V; Rykov, Anatolii N; Vilkov, Lev V
2007-07-19
The molecular structure of 1,3-dihydroxyacetone (DHA) has been studied by gas-phase electron diffraction (GED), combined analysis of GED and microwave (MW) data, ab initio, and density functional theory calculations. The equilibrium re structure of DHA was determined by a joint analysis of the GED data and rotational constants taken from the literature. The anharmonic vibrational corrections to the internuclear distances (re-ra) and to the rotational constants (B(i)e-B(i)0) needed for the estimation of the re structure were calculated from the B3LYP/cc-pVTZ cubic force field. It was found that the experimental data are well reproduced by assuming that DHA consists of a mixture of three conformers. The most stable conformer of C2v symmetry has two hydrogen bonds, whereas the next two lowest energy conformers (Cs and C1 symmetry) have one hydrogen bond and their abundance is about 30% in total. A combined analysis of GED and MW data led to the following equilibrium structural parameters (re) of the most abundant conformer of DHA (the uncertainties in parentheses are 3 times the standard deviations): r(C=O)=1.215(2) A, r(C-C)=1.516(2) A, r(C-O)=1.393(2) A, r(C-H)=1.096(4) A, r(O-H)=0.967(4) A, angleC-C=O=119.9(2) degrees, angleC-C-O=111.0(2) degrees, angleC-C-H=108.2(7) degrees, angleC-O-H=106.5(7) degrees. These structural parameters reproduce the experimental B(i)0 values within 0.05 MHz. The experimental structural parameters are in good agreement with those obtained from theoretical calculations. Ideal gas thermodynamic functions (S degrees (T), C degrees p(T), and H degrees (T)-H degrees (0)) of DHA were calculated on the basis of experimental and theoretical molecular parameters obtained in this work. The enthalpy of formation of DHA, -523+/-4 kJ/mol, was calculated by the atomization procedure using the G3X method.
Palmer, David S; Frolov, Andrey I; Ratkova, Ekaterina L; Fedorov, Maxim V
2010-12-15
We report a simple universal method to systematically improve the accuracy of hydration free energies calculated using an integral equation theory of molecular liquids, the 3D reference interaction site model. A strong linear correlation is observed between the difference of the experimental and (uncorrected) calculated hydration free energies and the calculated partial molar volume for a data set of 185 neutral organic molecules from different chemical classes. By using the partial molar volume as a linear empirical correction to the calculated hydration free energy, we obtain predictions of hydration free energies in excellent agreement with experiment (R = 0.94, σ = 0.99 kcal mol (- 1) for a test set of 120 organic molecules).
International Nuclear Information System (INIS)
Palmer, David S; Frolov, Andrey I; Ratkova, Ekaterina L; Fedorov, Maxim V
2010-01-01
We report a simple universal method to systematically improve the accuracy of hydration free energies calculated using an integral equation theory of molecular liquids, the 3D reference interaction site model. A strong linear correlation is observed between the difference of the experimental and (uncorrected) calculated hydration free energies and the calculated partial molar volume for a data set of 185 neutral organic molecules from different chemical classes. By using the partial molar volume as a linear empirical correction to the calculated hydration free energy, we obtain predictions of hydration free energies in excellent agreement with experiment (R = 0.94, σ = 0.99 kcal mol -1 for a test set of 120 organic molecules). (fast track communication)
Tsyganov, D. L.
2017-11-01
A new model for calculating the rates of reactions of excitation, ionization, and atomic exchange is proposed. Diatomic molecule AB is an unstructured particle M upon the exchange of elastic-vibrational (VT) energy, i.e., a model of a shock forceful oscillator with a change in Hamiltonian (SFOH). The SFOH model is based on the quantum theory of strong perturbations. The SFOH model allows generalization in simulating the rates of the reactions of excitation, ionization, and atomic exchange in the vibrational-vibrational (VV) energy exchange of diatomic molecules, and the exchange of VV- and VT-energy of polyatomic molecules. The rate constants of the excitation of metastables A 3Σ u +, B 3Π g , W 3Δ u , B'3Σ u -, a'3Σ u -, and the ionization of a nitrogen molecules from ground state X2Σ g + upon a collision with a heavy structureless particle (a nitrogen molecule), are found as examples.
Yongquan, Han
2016-10-01
The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ``gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 × 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = constant = 6 × 1075, the value of this constant is the universe, The singular point should also equal to the constant Author: hanyongquan
Energy Technology Data Exchange (ETDEWEB)
Pedrinha, Saulo; Simoes, Leonardo; Goncalves, Felix T.T.; Carneiro, Jason T.G. [Petroleum Geoscience Technology Ltda. (PGT), Rio de Janeiro, RJ (Brazil)
2008-07-01
The calculation of the volume of hydrocarbons generated from a particular source rock a sedimentary basin provides numerical data that help to better describe the petroleum system, and evaluate its potential. Among the various methodologies developed for calculating the volume of oil there is a proposal by Schmoker (1994), which has the advantage to take into account the occurrence of the source rock area in the basin, and the spatial variations in the main geological parameters. Using the tools of a GIS, through the manipulation of georeferred maps, it is possible to calculate the volume of oil generated in a way that would be virtually impossible by using punctual data, only. Even the discretiation maps in minors areas allows, via attribute table in the GIS, the application of a Monte Carlo simulation, which allows to incorporate all the uncertainties related to the input data in the calculation, obtaining distributions of volumes associated with various parts of the final map being integrated throughout the basin. Isopac and maturation maps (Gonzaga et al., 2000), along with TOC data from Barreirinha formation, Amazon Basin, have been scanned and georeferred and, once in the GIS database, were treated in order to spatially distribute the geological properties of the source rock. Then, such maps were handled in accordance with Schmoker (1994) method, leading to a map of mass and distribution of oil generated in the basin at the regional scale. (author)
International Nuclear Information System (INIS)
Frericks, Bernd B.J.; Kirchhoff, Timm D.; Shin, Hoen-Oh; Stamm, Georg; Merkesdal, Sonja; Abe, Takehiko; Galanski, Michael; Schenk, Andrea; Peitgen, Heinz-Otto; Klempnauer, Juergen; Nashan, Bjoern
2006-01-01
The purpose was to assess the volumes of the different hepatic territories and especially the drainage of the right paramedian sector in adult living donor liver transplantation (ALDLT). CT was performed in 40 potential donors of whom 28 underwent partial living donation. Data sets of all potential donors were postprocessed using dedicated software for segmentation, volumetric analysis and visualization of liver territories. During an initial period, volumes and shapes of liver parts were calculated based on the individual portal venous perfusion areas. After partial hepatic congestion occurring in three grafts, drainage territories with special regard to MHV tributaries from the right paramedian sector, and the IRHV were calculated additionally. Results were visualized three-dimensionally and compared to the intraoperative findings. Calculated graft volumes based on hepatic venous drainage and graft weights correlated significantly (r=0.86,P<0.001). Mean virtual graft volume was 930 ml and drained as follows: RHV: 680 ml, IRHV: 170 ml (n=11); segment 5 MHV tributaries: 100 ml (n=16); segment 8 MHV tributaries: 110 ml (n=20). When present, the mean aberrant venous drainage fraction of the right liver lobe was 28%. The evaluated protocol allowed a reliable calculation of the hepatic venous draining areas and led to a change in the hepatic venous reconstruction strategy at our institution. (orig.)
International Nuclear Information System (INIS)
Watanabe, Nami; Komatani, Akio; Yamaguchi, Koichi; Takahashi, Kazuei
1998-01-01
The 99m Tc-MAG 3 plasma clearance method (MPC method), reported by Oriuchi et al., is a simple and useful count-based gamma camera method for calculating the 99m Tc-MAG 3 plasma clearance (CL MAG ). However, a discrepancy of CL MAG calculated by MPC method (MPC-CL MAG ) from the tubular extraction rate (TER) calculated by Russell's single-sample clearance determination (Russell-TER) was noted. The calculated plasma volume is assumed to be the cause. Since the plasma volume is reported to have a linear correlation with body surface area, Dissmann's formula was applied to calculate the plasma volume. Then Dissmann's formula was replaced by Ogawa's formula in the MPC method, and the procedure was then called the modified MPC method. The CL MAG were obtained using MPC method, modified MPC method and the TER was obtained Russell's method in 95 patients with urological disorders. Then the MPC-CL MAG and modified MPC-CL MAG were compared with Russell-TER. Comparison of the MPC-CL MAG with the Russell-TER demonstrated a coefficient of correlation of 0.82, but dissociation of the slope of regression lines was found between males and females. The modified MPC-CL MAG improved the coefficient of correlation to 0.92, and diminished the dissociation of the slope of regression lines between males and females. We verified that the dissociation was due to the plasma volume calculated by Ogawa's formula. Ogawa's formula included hematocrit, body weight, body height and different coefficients for gender. The plasma volume calculated by Ogawa's formula were lower in males and higher in females than that calculated by Dissmann's formula. And marked discrepancy in the plasma volume in patients with a body surface area below 0.5 m 2 was observed. So the MPC method might become more accurate by substituting Dissmann's formula for Ogawa's formula resoluting in a method that is applicable to both males and females, children and adults in clinical use. (author)
Graziano, Giuseppe
2006-04-07
The partial molar volume of n-alcohols at infinite dilution in water is smaller than the molar volume in the neat liquid phase. It is shown that the formula for the partial molar volume at infinite dilution obtained from the scaled particle theory equation of state for binary hard sphere mixtures is able to reproduce in a satisfactory manner the experimental data over a large temperature range. This finding implies that the packing effects play the fundamental role in determining the partial molar volume at infinite dilution in water also for solutes, such as n-alcohols, forming H bonds with water molecules. Since the packing effects in water are largely related to the small size of its molecules, the latter feature is the ultimate cause of the decrease in partial molar volume associated with the hydrophobic effect.
Lee, Chan Ho; Park, Young Joo; Ku, Ja Yoon; Ha, Hong Koo
2017-06-01
To evaluate the clinical application of computed tomography-based measurement of renal cortical volume and split renal volume as a single tool to assess the anatomy and renal function in patients with renal tumors before and after partial nephrectomy, and to compare the findings with technetium-99m dimercaptosuccinic acid renal scan. The data of 51 patients with a unilateral renal tumor managed by partial nephrectomy were retrospectively analyzed. The renal cortical volume of tumor-bearing and contralateral kidneys was measured using ImageJ software. Split estimated glomerular filtration rate and split renal volume calculated using this renal cortical volume were compared with the split renal function measured with technetium-99m dimercaptosuccinic acid renal scan. A strong correlation between split renal function and split renal volume of the tumor-bearing kidney was observed before and after surgery (r = 0.89, P volumetry had a strong correlation with the split renal function measured using technetium-99m dimercaptosuccinic acid renal scan. Computed tomography-based split renal volume measurement before and after partial nephrectomy can be used as a single modality for anatomical and functional assessment of the tumor-bearing kidney. © 2017 The Japanese Urological Association.
McCullough, Sheila M; Constable, Peter D
2003-08-01
To determine values for the total concentration of nonvolatile weak acids (Atot) and effective dissociation constant of nonvolatile weak acids (Ka) in plasma of cats. Convenience plasma samples of 5 male and 5 female healthy adult cats. Cats were sedated, and 20 mL of blood was obtained from the jugular vein. Plasma was tonometered at 37 degrees C to systematically vary PCO2 from 8 to 156 mm Hg, thereby altering plasma pH from 6.90 to 7.97. Plasma pH, PCO2, and concentrations of quantitatively important strong cations (Na+, K+, and Ca2+), strong anions (Cl-, lactate), and buffer ions (total protein, albumin, and phosphate) were determined. Strong ion difference was estimated from the measured strong ion concentrations and nonlinear regression used to calculate Atot and Ka from the measured pH and PCO2 and estimated strong ion difference. Mean (+/- SD) values were as follows: Atot = 24.3 +/- 4.6 mmol/L (equivalent to 0.35 mmol/g of protein or 0.76 mmol/g of albumin); Ka = 0.67 +/- 0.40 x 10(-7); and the negative logarithm (base 10) of Ka (pKa) = 7.17. At 37 degrees C, pH of 7.35, and a partial pressure of CO2 (PCO2) of 30 mm Hg, the calculated venous strong ion difference was 30 mEq/L. These results indicate that at a plasma pH of 7.35, a 1 mEq/L decrease in strong ion difference will decrease pH by 0.020, a 1 mm Hg decrease in PCO2 will increase plasma pH by 0.011, and a 1 g/dL decrease in albumin concentration will increase plasma pH by 0.093.
International Nuclear Information System (INIS)
Niemierko, Andrzej; Goitein, Michael
1991-01-01
The authors investigate a model of normal tissue complication probability for tissues that may be represented by a critical element architecture. They derive formulas for complication probability that apply to both a partial volume irradiation and to an arbitrary inhomogeneous dose distribution. The dose-volume isoeffect relationship which is a consequence of a critical element architecture is discussed and compared to the empirical power law relationship. A dose-volume histogram reduction scheme for a 'pure' critical element model is derived. In addition, a point-based algorithm which does not require precomputation of a dose-volume histogram is derived. The existing published dose-volume histogram reduction algorithms are analyzed. The authors show that the existing algorithms, developed empirically without an explicit biophysical model, have a close relationship to the critical element model at low levels of complication probability. However, it is also showed that they have aspects which are not compatible with a critical element model and the authors propose a modification to one of them to circumvent its restriction to low complication probabilities. (author). 26 refs.; 7 figs
Bajnóczi, Éva G; Németh, Zoltán; Vankó, György
2017-11-20
Even quite simple chemical systems can involve many components and chemical states, and sometimes it can be very difficult to differentiate them by their hardly separable physical-chemical properties. The Ni II -EDTA-CN - (EDTA = ethylenediaminetetraacetic acid) ternary system is a good example for this problem where, in spite of its fairly simple components and numerous investigations, several molecular combinations can exist, all of them not having been identified unambiguously yet. In order to achieve a detailed understanding of the reaction steps and chemical equilibria, methods are required in which the structural transitions in the different reaction steps can be followed via element-selective complex spectral feature sets. With the help of our recently developed von Hámos type high-resolution laboratory X-ray absorption spectrometer, both the structural variations and stability constants of the forming complexes were determined from the same measurement series, proving that X-ray absorption spectroscopy can be considered as a multifaced, table-top tool in coordination chemistry. Furthermore, with the help of theoretical calculations, independent structural evidence was also given for the formation of the [NiEDTA(CN)] 3- mixed complex.
International Nuclear Information System (INIS)
Fukushi, Shoji; Teraoka, Satomi.
1997-01-01
A new method which calculate end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) of the left ventricle from myocardial short axis images of ECG-gated SPECT using 99m Tc myocardial perfusion tracer has been designed. Eight frames per cardiac cycle ECG-gated 180 degrees SPECT was performed. Threshold method was used to detect myocardial borders automatically. The optimal threshold was 45% by myocardial SPECT phantom. To determine if EDV, ESV and LVEF can also be calculated by this method, 12 patients were correlated ventriculography (LVG) for 10 days each. The correlation coefficient with LVG was 0.918 (EDV), 0.935 (ESV) and 0.900 (LVEF). This method is excellent at objectivity and reproductivity because of the automatic detection of myocardial borders. It also provides useful information on heart function in addition to myocardial perfusion. (author)
Bloemen, G.W.
1981-01-01
Recently it was demonstrated how unsaturated hydraulic conductivities of soils can be calculated from granular composition and organic matter content (BLOEMEN, 1980a). This type of calculations has to be restricted to mineral soils because the capillary properties of organic soils will not be
Edwards, Matthew; Guggilla, Padmaja; Reedy, Angela; Ijaz, Quratulann; Janen, Afef; Uba, Samuel; Curley, Michael
2017-08-01
Previously, we have reported measurements of temperature-dependent surface resistivity of pure and multi-walled carbon nanotube (MWNCT) doped amorphous Polyvinyl Alcohol (PVA) thin films. In the temperature range from 22 °C to 40 °C with humidity-controlled environment, we found the surface resistivity to decrease initially, but to rise steadily as the temperature continued to increase. Moreover, electric surface current density (Js) was measured on the surface of pure and MWCNT doped PVA thin films. In this regard, the surface current density and electric field relationship follow Ohm's law at low electric fields. Unlike Ohmic conduction in metals where free electrons exist, selected captive electrons are freed or provided from impurities and dopants to become conduction electrons from increased thermal vibration of constituent atoms in amorphous thin films. Additionally, a mechanism exists that seemingly decreases the surface resistivity at higher temperatures, suggesting a blocking effect for conducting electrons. Volume resistivity measurements also follow Ohm's law at low voltages (low electric fields), and they continue to decrease as temperatures increase in this temperature range, differing from surface resistivity behavior. Moreover, we report measurements of dielectric constant and dielectric loss as a function of temperature and frequency. Both the dielectric constant and dielectric loss were observed to be highest for MWCNT doped PVA compared to pure PVA and commercial paper, and with frequency and temperature for all samples.
Jonny Nordström; Tanja Kero; Hendrik Johannes Harms; Charles Widström; Frank A. Flachskampf; Jens Sörensen; Mark Lubberink
2017-01-01
BACKGROUND: Quantitative measurement of myocardial blood flow (MBF) is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD). (15)O-water positron emission tomography (PET) is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV) volumes and ejection fraction (EF) is not possible from standard (15)O-water uptake images. The purpose of the present work was to investigate the possibility...
Hori, Masatoshi; Suzuki, Kenji; Epstein, Mark L.; Baron, Richard L.
2011-01-01
The purpose was to evaluate a relationship between slice thickness and calculated volume on CT liver volumetry by comparing the results for images with various slice thicknesses including three-dimensional images. Twenty adult potential liver donors (12 men, 8 women; mean age, 39 years; range, 24–64) underwent CT with a 64-section multi-detector row CT scanner after intra-venous injection of contrast material. Four image sets with slice thicknesses of 0.625 mm, 2.5 mm, 5 mm, and 10 mm were used. First, a program developed in our laboratory for automated liver extraction was applied to CT images, and the liver boundary was obtained automatically. Then, an abdominal radiologist reviewed all images on which automatically extracted boundaries were superimposed, and edited the boundary on each slice to enhance the accuracy. Liver volumes were determined by counting of the voxels within the liver boundary. Mean whole liver volumes estimated with CT were 1322.5 cm3 on 0.625-mm, 1313.3 cm3 on 2.5-mm, 1310.3 cm3 on 5-mm, and 1268.2 cm3 on 10-mm images. Volumes calculated for three-dimensional (0.625-mm-thick) images were significantly larger than those for thicker images (Pvolumetry. If not, three-dimensional images could be essential. PMID:21850689
Energy Technology Data Exchange (ETDEWEB)
De Neve, W; Derycke, S; De Wagter, C [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde
1995-12-01
A heuristic planing procedure allowing to obtain a 3-dimensional conformal dose distribution in radiotherapy for target volumes with a bi-concave or multi-concave shape has been developed. The described method is tested on a phantom simulating a pelvic target, described by Brahme.
Constant physics and characteristics of fundamental constant
International Nuclear Information System (INIS)
Tarrach, R.
1998-01-01
We present some evidence which supports a surprising physical interpretation of the fundamental constants. First, we relate two of them through the renormalization group. This leaves as many fundamental constants as base units. Second, we introduce and a dimensional system of units without fundamental constants. Third, and most important, we find, while interpreting the units of the a dimensional system, that is all cases accessible to experimentation the fundamental constants indicate either discretization at small values or boundedness at large values of the corresponding physical quantity. (Author) 12 refs
International Nuclear Information System (INIS)
Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A.; Schirru, Roberto; Silva, Ademir Xavier da
2009-01-01
Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a 241 Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)
Energy Technology Data Exchange (ETDEWEB)
Ramos, Robson; Brandao, Luis E.B.; Pereira, Claudio M.N.A., E-mail: robson@ien.gov.b, E-mail: brandao@ien.gov.b, E-mail: cmnap@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos; Schirru, Roberto; Silva, Ademir Xavier da, E-mail: schirru@lmp.ufrj.b, E-mail: ademir@con.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Nuclear Engineering Dept.
2009-07-01
Multiphase flows, type oil-water-gas are very common among different industrial activities, such as chemical industries and petroleum extraction, and its measurements show some difficulties to be taken. Precisely determining the volume fraction of each one of the elements that composes a multiphase flow is very important in chemical plants and petroleum industries. This work presents a methodology able to determine volume fraction on Annular and Stratified multiphase flow system with the use of neutrons and artificial intelligence, using the principles of transmission/scattering of fast neutrons from a {sup 241}Am-Be source and measurements of point flow that are influenced by variations of volume fractions. The proposed geometries used on the mathematical model was used to obtain a data set where the thicknesses referred of each material had been changed in order to obtain volume fraction of each phase providing 119 compositions that were used in the simulation with MCNP-X -computer code based on Monte Carlo Method that simulates the radiation transport. An artificial neural network (ANN) was trained with data obtained using the MCNP-X, and used to correlate such measurements with the respective real fractions. The ANN was able to correlate the data obtained on the simulation with MCNP-X with the volume fractions of the multiphase flows (oil-water-gas), both in the pattern of annular flow as stratified, resulting in a average relative error (%) for each production set of: annular (air = 3.85; water = 4.31; oil=1.08); stratified (air = 3.10, water 2.01, oil = 1.45). The method demonstrated good efficiency in the determination of each material that composes the phases, thus demonstrating the feasibility of the technique. (author)
Strain fluctuations and elastic constants
Energy Technology Data Exchange (ETDEWEB)
Parrinello, M.; Rahman, A.
1982-03-01
It is shown that the elastic strain fluctuations are a direct measure of elastic compliances in a general anisotropic medium; depending on the ensemble in which the fluctuation is measured either the isothermal or the adiabatic compliances are obtained. These fluctuations can now be calculated in a constant enthalpy and pressure, and hence, constant entropy, ensemble due to recent develpments in the molecular dynamics techniques. A calculation for a Ni single crystal under uniform uniaxial 100 tensile or compressive load is presented as an illustration of the relationships derived between various strain fluctuations and the elastic modulii. The Born stability criteria and the behavior of strain fluctuations are shown to be related.
Kou, Jisheng; Sun, Shuyu
2017-01-01
Capillary pressure can significantly affect the phase properties and flow of liquid-gas fluids in porous media, and thus, the phase equilibrium calculation incorporating capillary pressure is crucial to simulate such problems accurately. Recently
Kereszturi, Gábor; Németh, Károly; Cronin, Shane J.; Agustín-Flores, Javier; Smith, Ian E. M.; Lindsay, Jan
2013-10-01
Monogenetic basaltic volcanism is characterised by a complex array of behaviours in the spatial distribution of magma output and also temporal variability in magma flux and eruptive frequency. Investigating this in detail is hindered by the difficulty in evaluating ages of volcanic events as well as volumes erupted in each volcano. Eruptive volumes are an important input parameter for volcanic hazard assessment and may control eruptive scenarios, especially transitions between explosive and effusive behaviour and the length of eruptions. Erosion, superposition and lack of exposure limit the accuracy of volume determination, even for very young volcanoes. In this study, a systematic volume estimation model is developed and applied to the Auckland Volcanic Field in New Zealand. In this model, a basaltic monogenetic volcano is categorised in six parts. Subsurface portions of volcanoes, such as diatremes beneath phreatomagmatic volcanoes, or crater infills, are approximated by geometrical considerations, based on exposed analogue volcanoes. Positive volcanic landforms, such as scoria/spatter cones, tephras rings and lava flow, were defined by using a Light Detection and Ranging (LiDAR) survey-based Digital Surface Model (DSM). Finally, the distal tephra associated with explosive eruptions was approximated using published relationships that relate original crater size to ejecta volumes. Considering only those parts with high reliability, the overall magma output (converted to Dense Rock Equivalent) for the post-250 ka active Auckland Volcanic Field in New Zealand is a minimum of 1.704 km3. This is made up of 1.329 km3 in lava flows, 0.067 km3 in phreatomagmatic crater lava infills, 0.090 km3 within tephra/tuff rings, 0.112 km3 inside crater lava infills, and 0.104 km3 within scoria cones. Using the minimum eruptive volumes, the spatial and temporal magma fluxes are estimated at 0.005 km3/km2 and 0.007 km3/ka. The temporal-volumetric evolution of Auckland is
Energy Technology Data Exchange (ETDEWEB)
Trzcinski, A.; Zwieglinski, B. [Soltan Inst. for Nuclear Studies, Warsaw (Poland); Lynen, U. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Pochodzalla, J. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)
1998-10-01
This paper reports on a Monte-Carlo program, MSX, developed to evaluate the performance of large-volume, Gd-loaded liquid scintillation detectors used in neutron multiplicity measurements. The results of simulations are presented for the detector intended to count neutrons emitted by the excited target residue in coincidence with the charged products of the projectile fragmentation following relativistic heavy-ion collisions. The latter products could be detected with the ALADIN magnetic spectrometer at GSI-Darmstadt. (orig.) 61 refs.
Miller, R. D.; Anderson, L. R.
1979-01-01
The LOADS program L218, a digital computer program that calculates dynamic load coefficient matrices utilizing the force summation method, is described. The load equations are derived for a flight vehicle in straight and level flight and excited by gusts and/or control motions. In addition, sensor equations are calculated for use with an active control system. The load coefficient matrices are calculated for the following types of loads: translational and rotational accelerations, velocities, and displacements; panel aerodynamic forces; net panel forces; shears and moments. Program usage and a brief description of the analysis used are presented. A description of the design and structure of the program to aid those who will maintain and/or modify the program in the future is included.
Energy Technology Data Exchange (ETDEWEB)
Goodman, A L [Tulane Univ., New Orleans, LA (United States)
1992-08-01
Statistical orientation fluctuations are calculated with two alternative assumptions: the rotational frequency remains constant as the shape orientation fluctuates; and, the average angular momentum remains constant as the shape orientation fluctuates. (author). 2 refs., 3 figs.
International Nuclear Information System (INIS)
Simonkova, J.
1988-01-01
The problems are summed up of the dynamic calculation of cooling towers with forced and natural air draft. The quantities and relations are given characterizing the simultaneous exchange of momentum, heat and mass in evaporative water cooling by atmospheric air in the packings of cooling towers. The method of solution is clarified in the calculation of evaporation criteria and thermal characteristics of countercurrent and cross current cooling systems. The procedure is demonstrated of the calculation of cooling towers, and correction curves and the effect assessed of the operating mode at constant air number or constant outlet air volume flow on their course in ventilator cooling towers. In cooling towers with the natural air draft the flow unevenness is assessed of water and air relative to its effect on the resulting cooling efficiency of the towers. The calculation is demonstrated of thermal and resistance response curves and cooling curves of hydraulically unevenly loaded towers owing to the water flow rate parameter graded radially by 20% along the cross-section of the packing. Flow rate unevenness of air due to wind impact on the outlet air flow from the tower significantly affects the temperatures of cooled water in natural air draft cooling towers of a design with lower demands on aerodynamics, as early as at wind velocity of 2 m.s -1 as was demonstrated on a concrete example. (author). 11 figs., 10 refs
Stresses and elastic constants of crystalline sodium, from molecular dynamics
International Nuclear Information System (INIS)
Schiferl, S.K.
1985-02-01
The stresses and the elastic constants of bcc sodium are calculated by molecular dynamics (MD) for temperatures to T = 340K. The total adiabatic potential of a system of sodium atoms is represented by pseudopotential model. The resulting expression has two terms: a large, strictly volume-dependent potential, plus a sum over ion pairs of a small, volume-dependent two-body potential. The stresses and the elastic constants are given as strain derivatives of the Helmholtz free energy. The resulting expressions involve canonical ensemble averages (and fluctuation averages) of the position and volume derivatives of the potential. An ensemble correction relates the results to MD equilibrium averages. Evaluation of the potential and its derivatives requires the calculation of integrals with infinite upper limits of integration, and integrand singularities. Methods for calculating these integrals and estimating the effects of integration errors are developed. A method is given for choosing initial conditions that relax quickly to a desired equilibrium state. Statistical methods developed earlier for MD data are extended to evaluate uncertainties in fluctuation averages, and to test for symmetry. 45 refs., 10 figs., 4 tabs
Cosmological Hubble constant and nuclear Hubble constant
International Nuclear Information System (INIS)
Horbuniev, Amelia; Besliu, Calin; Jipa, Alexandru
2005-01-01
The evolution of the Universe after the Big Bang and the evolution of the dense and highly excited nuclear matter formed by relativistic nuclear collisions are investigated and compared. Values of the Hubble constants for cosmological and nuclear processes are obtained. For nucleus-nucleus collisions at high energies the nuclear Hubble constant is obtained in the frame of different models involving the hydrodynamic flow of the nuclear matter. Significant difference in the values of the two Hubble constant - cosmological and nuclear - is observed
Universal relation between spectroscopic constants
Indian Academy of Sciences (India)
(3) The author has used eq. (6) of his paper to calculate De. This relation leads to a large deviation from the correct value depending upon the extent to which experimental values are known. Guided by this fact, in our work, we used experimentally observed De values to derive the relation between spectroscopic constants.
Energy Technology Data Exchange (ETDEWEB)
Gurevich, M. I.; Oleynik, D. S. [RRC Kurchatov Inst., Kurchatov Sq., 1, 123182, Moscow (Russian Federation); Russkov, A. A.; Voloschenko, A. M. [Keldysh Inst. of Applied Mathematics, Miusskaya Sq., 4, 125047, Moscow (Russian Federation)
2006-07-01
The tracing algorithm that is implemented in the geometrical module of Monte-Carlo transport code MCU is applied to calculate the volume fractions of original materials by spatial cells of the mesh that overlays problem geometry. In this way the 3D combinatorial geometry presentation of the problem geometry, used by MCU code, is transformed to the user defined 2D or 3D bit-mapped ones. Next, these data are used in the volume fraction (VF) method to approximate problem geometry by introducing additional mixtures for spatial cells, where a few original materials are included. We have found that in solving realistic 2D and 3D core problems a sufficiently fast convergence of the VF method takes place if the spatial mesh is refined. Virtually, the proposed variant of implementation of the VF method seems as a suitable geometry interface between Monte-Carlo and S{sub n} transport codes. (authors)
Luchko, Tyler; Blinov, Nikolay; Limon, Garrett C; Joyce, Kevin P; Kovalenko, Andriy
2016-11-01
Implicit solvent methods for classical molecular modeling are frequently used to provide fast, physics-based hydration free energies of macromolecules. Less commonly considered is the transferability of these methods to other solvents. The Statistical Assessment of Modeling of Proteins and Ligands 5 (SAMPL5) distribution coefficient dataset and the accompanying explicit solvent partition coefficient reference calculations provide a direct test of solvent model transferability. Here we use the 3D reference interaction site model (3D-RISM) statistical-mechanical solvation theory, with a well tested water model and a new united atom cyclohexane model, to calculate partition coefficients for the SAMPL5 dataset. The cyclohexane model performed well in training and testing ([Formula: see text] for amino acid neutral side chain analogues) but only if a parameterized solvation free energy correction was used. In contrast, the same protocol, using single solute conformations, performed poorly on the SAMPL5 dataset, obtaining [Formula: see text] compared to the reference partition coefficients, likely due to the much larger solute sizes. Including solute conformational sampling through molecular dynamics coupled with 3D-RISM (MD/3D-RISM) improved agreement with the reference calculation to [Formula: see text]. Since our initial calculations only considered partition coefficients and not distribution coefficients, solute sampling provided little benefit comparing against experiment, where ionized and tautomer states are more important. Applying a simple [Formula: see text] correction improved agreement with experiment from [Formula: see text] to [Formula: see text], despite a small number of outliers. Better agreement is possible by accounting for tautomers and improving the ionization correction.
Luchko, Tyler; Blinov, Nikolay; Limon, Garrett C.; Joyce, Kevin P.; Kovalenko, Andriy
2016-11-01
Implicit solvent methods for classical molecular modeling are frequently used to provide fast, physics-based hydration free energies of macromolecules. Less commonly considered is the transferability of these methods to other solvents. The Statistical Assessment of Modeling of Proteins and Ligands 5 (SAMPL5) distribution coefficient dataset and the accompanying explicit solvent partition coefficient reference calculations provide a direct test of solvent model transferability. Here we use the 3D reference interaction site model (3D-RISM) statistical-mechanical solvation theory, with a well tested water model and a new united atom cyclohexane model, to calculate partition coefficients for the SAMPL5 dataset. The cyclohexane model performed well in training and testing (R=0.98 for amino acid neutral side chain analogues) but only if a parameterized solvation free energy correction was used. In contrast, the same protocol, using single solute conformations, performed poorly on the SAMPL5 dataset, obtaining R=0.73 compared to the reference partition coefficients, likely due to the much larger solute sizes. Including solute conformational sampling through molecular dynamics coupled with 3D-RISM (MD/3D-RISM) improved agreement with the reference calculation to R=0.93. Since our initial calculations only considered partition coefficients and not distribution coefficients, solute sampling provided little benefit comparing against experiment, where ionized and tautomer states are more important. Applying a simple pK_{ {a}} correction improved agreement with experiment from R=0.54 to R=0.66, despite a small number of outliers. Better agreement is possible by accounting for tautomers and improving the ionization correction.
International Nuclear Information System (INIS)
Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck
2016-01-01
This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the facilities after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)
Experimental Determination of the Avogadro Constant
Indian Academy of Sciences (India)
mental physical constant such as charge of an electron or the. Boltzmann constant ... ideas was that the number of particles or molecules in a gas of given volume could not ... knowledge of at least one property of a single molecule. Loschmidt ...
Energy Technology Data Exchange (ETDEWEB)
Reinhardt, Michael J; Joe, Alexius Y; Mallek, Dirk von; Ezziddin, Samer; Palmedo, Holger [Department of Nuclear Medicine, University Hospital of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany); Brink, Ingo [Department of Nuclear Medicine, University Hospital of Freiburg (Germany); Krause, Thomas M [Department of Nuclear Medicine, Inselspital Bern (Switzerland)
2002-09-01
This study was performed with three aims. The first was to analyse the effectiveness of radioiodine therapy in Graves' disease patients with and without goitres under conditions of mild iodine deficiency using several tissue-absorbed doses. The second aim was to detect further parameters which might be predictive for treatment outcome. Finally, we wished to determine the deviation of the therapeutically achieved dose from that intended. Activities of 185-2,220 MBq radioiodine were calculated by means of Marinelli's formula to deliver doses of 150, 200 or 300 Gy to the thyroids of 224 patients with Graves' disease and goitres up to 130 ml in volume. Control of hyperthyroidism, change in thyroid volume and thyrotropin-receptor antibodies were evaluated 15{+-}9 months after treatment for each dose. The results were further evaluated with respect to pre-treatment parameters which might be predictive for therapy outcome. Thyroidal radioiodine uptake was measured every day during therapy to determine the therapeutically achieved target dose and its coefficient of variation. There was a significant dose dependency in therapeutic outcome: frequency of hypothyroidism increased from 27.4% after 150 Gy to 67.7% after 300 Gy, while the frequency of persistent hyperthyroidism decreased from 27.4% after 150 Gy to 8.1% after 300 Gy. Patients who became hypothyroid had a maximum thyroid volume of 42 ml and received a target dose of 256{+-}80 Gy. The coefficient of variation for the achieved target dose ranged between 27.7% for 150 Gy and 17.8% for 300 Gy. When analysing further factors which might influence therapeutic outcome, only pre-treatment thyroid volume showed a significant relationship to the result of treatment. It is concluded that a target dose of 250 Gy is essential to achieve hypothyroidism within 1 year after radioiodine therapy in Graves' disease patients with goitres up to 40 ml in volume. Patients with larger goitres might need higher doses. (orig.)
International Nuclear Information System (INIS)
Reinhardt, Michael J.; Joe, Alexius Y.; Mallek, Dirk von; Ezziddin, Samer; Palmedo, Holger; Brink, Ingo; Krause, Thomas M.
2002-01-01
This study was performed with three aims. The first was to analyse the effectiveness of radioiodine therapy in Graves' disease patients with and without goitres under conditions of mild iodine deficiency using several tissue-absorbed doses. The second aim was to detect further parameters which might be predictive for treatment outcome. Finally, we wished to determine the deviation of the therapeutically achieved dose from that intended. Activities of 185-2,220 MBq radioiodine were calculated by means of Marinelli's formula to deliver doses of 150, 200 or 300 Gy to the thyroids of 224 patients with Graves' disease and goitres up to 130 ml in volume. Control of hyperthyroidism, change in thyroid volume and thyrotropin-receptor antibodies were evaluated 15±9 months after treatment for each dose. The results were further evaluated with respect to pre-treatment parameters which might be predictive for therapy outcome. Thyroidal radioiodine uptake was measured every day during therapy to determine the therapeutically achieved target dose and its coefficient of variation. There was a significant dose dependency in therapeutic outcome: frequency of hypothyroidism increased from 27.4% after 150 Gy to 67.7% after 300 Gy, while the frequency of persistent hyperthyroidism decreased from 27.4% after 150 Gy to 8.1% after 300 Gy. Patients who became hypothyroid had a maximum thyroid volume of 42 ml and received a target dose of 256±80 Gy. The coefficient of variation for the achieved target dose ranged between 27.7% for 150 Gy and 17.8% for 300 Gy. When analysing further factors which might influence therapeutic outcome, only pre-treatment thyroid volume showed a significant relationship to the result of treatment. It is concluded that a target dose of 250 Gy is essential to achieve hypothyroidism within 1 year after radioiodine therapy in Graves' disease patients with goitres up to 40 ml in volume. Patients with larger goitres might need higher doses. (orig.)
Maples, A. L.; Poirier, D. R.
1980-01-01
The physical and numerical formulation of a model for the horizontal solidification of a binary alloy is described. It can be applied in an ingot. The major purpose of the model is to calculate macrosegregation in a casting ingot which results from flow of interdendritic liquid during solidification. The flow, driven by solidification contractions and by gravity acting on density gradients in the interdendritic liquid, was modeled as flow through a porous medium. The symbols used are defined. The physical formulation of the problem leading to a set of equations which can be used to obtain: (1) the pressure field; (2) the velocity field: (3) mass flow and (4) solute flow in the solid plus liquid zone during solidification is presented. With these established, the model calculates macrosegregation after solidification is complete. The numerical techniques used to obtain solution on a computational grid are presented. Results, evaluation of the results, and recommendations for future development of the model are given. The macrosegregation and flow field predictions for tin-lead, aluminum-copper, and tin-bismuth alloys are included as well as comparisons of some of the predictions with published predictions or with empirical data.
Ion exchange equilibrium constants
Marcus, Y
2013-01-01
Ion Exchange Equilibrium Constants focuses on the test-compilation of equilibrium constants for ion exchange reactions. The book first underscores the scope of the compilation, equilibrium constants, symbols used, and arrangement of the table. The manuscript then presents the table of equilibrium constants, including polystyrene sulfonate cation exchanger, polyacrylate cation exchanger, polymethacrylate cation exchanger, polysterene phosphate cation exchanger, and zirconium phosphate cation exchanger. The text highlights zirconium oxide anion exchanger, zeolite type 13Y cation exchanger, and
Directory of Open Access Journals (Sweden)
L Mousavi Seresht
2014-01-01
Full Text Available Background : Appropriate determination of tidal volume (VT is important for preventing ventilation induced lung injury. We compared hemodynamic and respiratory parameters in two conditions of receiving VTs calculated by using body weight (BW, which was estimated by measured height (HBW or demi-span based body weight (DBW. Materials and Methods : This controlled-trial was conducted in St. Alzahra Hospital in 2009 on American Society of Anesthesiologists (ASA I and II, 18-65-years-old patients. Standing height and weight were measured and then height was calculated using demi-span method. BW and VT were calculated with acute respiratory distress syndrome-net formula. Patients were randomized and then crossed to receive ventilation with both calculated VTs for 20 min. Hemodynamic and respiratory parameters were analyzed with SPSS version 20.0 using univariate and multivariate analyses. Results : Forty nine patients were studied. Demi-span based body weight and thus VT (DTV were lower than Height based body weight and VT (HTV (P = 0.028, in male patients (P = 0.005. Difference was observed in peak airway pressure (PAP and airway resistance (AR changes with higher PAP and AR at 20 min after receiving HTV compared with DTV. Conclusions : Estimated VT based on measured height is higher than that based on demi-span and this difference exists only in females, and this higher VT results higher airway pressures during mechanical ventilation.
International Nuclear Information System (INIS)
Aydin, H.; Richter, E.; Feyerabend, T.; Bohndorf, W.
1990-01-01
The volumetric analysis of a tumour by CT is a reliable and clinically important method of examination which is rarely used. As for oncology, the importance of this method is based upon the determination of the stage of remission posttherapeutically, especially in those cases which respond to therapy without a roentgenologic change in comparison to pretherapeutic findings. This applies in particular for the evaluation of CT images. In this study 115 CT examinations of 38 patients with recurrent rectal cancer were evaluated and the tumour remission was measured by an exact determination of the tumour volume before and after radiotherapy. The results were compared with the CT findings without volumetric analysis. A change of the tumour size up to 20% of the pretherapeutic volume which eludes from the visual perception can be revealed by a subtle CT-assisted volumetric analysis. Formulas for calculation of the volume or the data concerning length, width and depth of a mass prove to be insufficient or incorrect. Therefore the correct evaluation of a tumour regression or progression shoud be done more often by CT-assisted volumetric analysis. (orig.) [de
Reich, H; Moens, Y; Braun, C; Kneissl, S; Noreikat, K; Reske, A
2014-12-01
Quantitative computer tomographic analysis (qCTA) is an accurate but time intensive method used to quantify volume, mass and aeration of the lungs. The aim of this study was to validate a time efficient interpolation technique for application of qCTA in ponies. Forty-one thoracic computer tomographic (CT) scans obtained from eight anaesthetised ponies positioned in dorsal recumbency were included. Total lung volume and mass and their distribution into four compartments (non-aerated, poorly aerated, normally aerated and hyperaerated; defined based on the attenuation in Hounsfield Units) were determined for the entire lung from all 5 mm thick CT-images, 59 (55-66) per animal. An interpolation technique validated for use in humans was then applied to calculate qCTA results for lung volumes and masses from only 10, 12, and 14 selected CT-images per scan. The time required for both procedures was recorded. Results were compared statistically using the Bland-Altman approach. The bias ± 2 SD for total lung volume calculated from interpolation of 10, 12, and 14 CT-images was -1.2 ± 5.8%, 0.1 ± 3.5%, and 0.0 ± 2.5%, respectively. The corresponding results for total lung mass were -1.1 ± 5.9%, 0.0 ± 3.5%, and 0.0 ± 3.0%. The average time for analysis of one thoracic CT-scan using the interpolation method was 1.5-2 h compared to 8 h for analysis of all images of one complete thoracic CT-scan. The calculation of pulmonary qCTA data by interpolation from 12 CT-images was applicable for equine lung CT-scans and reduced the time required for analysis by 75%. Copyright © 2014 Elsevier Ltd. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Debreczeny, Martin Paul [Univ. of California, Berkeley, CA (United States)
1994-05-01
We have measured and assigned rate constants for energy transfer between chromophores in the light-harvesting protein C-phycocyanin (PC), in the monomeric and trimeric aggregation states, isolated from Synechococcus sp. PCC 7002. In order to compare the measured rate constants with those predicted by Fdrster`s theory of inductive resonance in the weak coupling limit, we have experimentally resolved several properties of the three chromophore types ({beta}{sub 155} {alpha}{sub 84}, {beta}{sub 84}) found in PC monomers, including absorption and fluorescence spectra, extinction coefficients, fluorescence quantum yields, and fluorescence lifetimes. The cpcB/C155S mutant, whose PC is missing the {beta}{sub 155} chromophore, was, useful in effecting the resolution of the chromophore properties and in assigning the experimentally observed rate constants for energy transfer to specific pathways.
Fuchs, Susanne I; Junge, Sibylle; Ellemunter, Helmut; Ballmann, Manfred; Gappa, Monika
2013-05-01
Volumetric capnography reflecting the course of CO2-exhalation is used to assess ventilation inhomogeneity. Calculation of the slope of expiratory phase 3 and the capnographic index (KPIv) from expirograms allows quantification of extent and severity of small airway impairment. However, technical limitations have hampered more widespread use of this technique. Using expiratory molar mass-volume-curves sampled with a handheld ultrasonic flow sensor during tidal breathing is a novel approach to extract similar information from expirograms in a simpler manner possibly qualifying as a screening tool for clinical routine. The aim of the present study was to evaluate calculation of the KPIv based on molar mass-volume-curves sampled with an ultrasonic flow sensor in patients with CF and controls by assessing feasibility, reproducibility and comparability with the Lung Clearance Index (LCI) derived from multiple breath washout (MBW) used as the reference method. Measurements were performed in patients with CF and healthy controls during a single test occasion using the EasyOne Pro, MBW Module (ndd Medical Technologies, Switzerland). Capnography and MBW were performed in 87/96 patients with CF and 38/42 controls, with a success rate of 90.6% for capnography. Mean age (range) was 12.1 (4-25) years. Mean (SD) KPIv was 6.94 (3.08) in CF and 5.10 (2.06) in controls (p=0.001). Mean LCI (SD) was 8.0 (1.4) in CF and 6.2 (0.4) in controls (p=molar mass-volume-curves is feasible. KPIv is significantly different between patients with CF and controls and correlates with the LCI. However, individual data revealed a relevant overlap between patients and controls requiring further evaluation, before this method can be recommended for clinical use. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.
Precise calculation of the energies of heavy hydrogenlike ions
International Nuclear Information System (INIS)
Driker, M.N.; Ivanova, E.P.; Ivanov, L.N.
1983-01-01
Energies of the 1s, 2s, and 2p states are calculated for hydrogenlike ions with z = 30--170. The calculation is based on Dirac's equation taking into account radiation effects and the finiteness of the nucleus. The hyperfine splitting constants are calculated taking the finiteness of the nucleus into account, and derivatives are taken with respect to the volume of the nucleus for all S-state characteristics
Directory of Open Access Journals (Sweden)
E. V. Semenov
2015-01-01
Full Text Available Summary. The process of separation bulk mixtures in the air stream is widespread in production associated with the cleaning of grain from impurity. In doing so, in order to effectively use the force of gravity appropriate cleaning grain in vertical air stream. Quantitative analysis of the separation process considering based on the model of the motion of an isolated particles in the stream. We used law of conservation of impulse in the form of the second law of Newton. Movement of particles in the air stream develops in conditions of large of number Reynolds. Therefore, the resistance force particles chosen by quadratic depending on its relative speed. Based on the quantitative analysis of the equations of motion of a particle moving on a specific trajectory, determine the critical diameter of the particles. As a process control setting chosen by the speed of the airflow. Based on the dispersion factor mixture of granular calculated coefficient of lightening. A specific example of equipment based on geometrical and physical-mechanical parameters of the process graphically presents the results of a qualitative and meaningful analysis on trajectories and velocities of the particles, the critical diameter of particle, coefficient of lightening.
Determination of mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal.
Soluch, Waldemar; Brzozowski, Ernest; Lysakowska, Magdalena; Sadura, Jolanta
2011-11-01
Mass density, dielectric, elastic, and piezoelectric constants of bulk GaN crystal were determined. Mass density was obtained from the measured ratio of mass to volume of a cuboid. The dielectric constants were determined from the measured capacitances of an interdigital transducer (IDT) deposited on a Z-cut plate and from a parallel plate capacitor fabricated from this plate. The elastic and piezoelectric constants were determined by comparing the measured and calculated SAW velocities and electromechanical coupling coefficients on the Z- and X-cut plates. The following new constants were obtained: mass density p = 5986 kg/m(3); relative dielectric constants (at constant strain S) ε(S)(11)/ε(0) = 8.6 and ε(S)(11)/ε(0) = 10.5, where ε(0) is a dielectric constant of free space; elastic constants (at constant electric field E) C(E)(11) = 349.7, C(E)(12) = 128.1, C(E)(13) = 129.4, C(E)(33) = 430.3, and C(E)(44) = 96.5 GPa; and piezoelectric constants e(33) = 0.84, e(31) = -0.47, and e(15) = -0.41 C/m(2).
Pressure Dependence of Molar Volume near the Melting Point in Benzene
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The pressure dependence of the molar volume was at constant temperatures close to the melting point in benzene. The molar volume of benzene was calculated using experimental data for the thermal expansivity for constant temperatures of 25℃, 28.5℃, 40℃, and 51℃ at various pressures for both the solid and liquid phases. The predictions are in good agreement with the observed volumes in both the solid and liquid phases of benzene. The predicted values of the molar volume for a constant temperature of 28.5℃ in the liquid phase of benzene agree well with experimental data in the literature.
Effective constants for wave propagation through partially saturated porous media
International Nuclear Information System (INIS)
Berryman, J.G.; Thigpen, L.
1985-01-01
The multipole scattering coefficients for elastic wave scattering from a spherical inhomogeneity in a fluid-saturated porous medium have been calculated. These coefficients may be used to obtain estimates of the effective macroscopic constants for long-wavelength propagation of elastic waves through partially saturated media. If the volume average of the single scattering from spherical bubbles of gas and liquid is required to vanish, the resulting equations determine the effective bulk modulus, density, and viscosity of the multiphase fluid filling the pores. The formula for the effective viscosity during compressional wave excitation is apparently new
International Nuclear Information System (INIS)
Sewell, Thomas D.; Bennett, Carl M.
2000-01-01
Isothermal-isobaric Monte Carlo calculations were used to obtain predictions of the elastic coefficients and derived engineering moduli and Poisson ratios for crystalline hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The elastic coefficients were computed using the strain fluctuation formula due to Rahman and Parrinello [J. Chem. Phys. 76, 2662 (1982)]. Calculations were performed as a function of temperature (218 K≤T≤333 K) and hydrostatic pressure (0 GPa≤p≤4 GPa). The predicted values of the moduli and Poisson ratios under ambient conditions are in accord with general expectations for molecular crystals and with a very recent, unpublished determination for RDX. The moduli exhibit a sensitive pressure dependence whereas the Poisson ratios are relatively independent of pressure. The temperature dependence of the moduli is comparable to the precision of the results. However, the crystal does exhibit thermal softening for most pressures. An additional product of the calculations is information about the pressure-volume-temperature (pVT) equation of state. We obtain near-quantitative agreement with experiment for the case of hydrostatic compression and reasonable, but not quantitative, correspondence for thermal expansion. The results indicate a significant dependence of the thermal expansion coefficients on hydrostatic pressure. (c) 2000 American Institute of Physics
Energy Technology Data Exchange (ETDEWEB)
Reinhardt, Michael J.; Joe, Alexius Y.; Mallek, Dirk von; Ezziddin, Samer; Palmedo, Holger [Department of Nuclear Medicine, University Hospital of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn (Germany); Brink, Ingo [Department of Nuclear Medicine, University Hospital of Freiburg (Germany); Krause, Thomas M. [Department of Nuclear Medicine, Inselspital Bern (Switzerland)
2002-09-01
This study was performed with three aims. The first was to analyse the effectiveness of radioiodine therapy in Graves' disease patients with and without goitres under conditions of mild iodine deficiency using several tissue-absorbed doses. The second aim was to detect further parameters which might be predictive for treatment outcome. Finally, we wished to determine the deviation of the therapeutically achieved dose from that intended. Activities of 185-2,220 MBq radioiodine were calculated by means of Marinelli's formula to deliver doses of 150, 200 or 300 Gy to the thyroids of 224 patients with Graves' disease and goitres up to 130 ml in volume. Control of hyperthyroidism, change in thyroid volume and thyrotropin-receptor antibodies were evaluated 15{+-}9 months after treatment for each dose. The results were further evaluated with respect to pre-treatment parameters which might be predictive for therapy outcome. Thyroidal radioiodine uptake was measured every day during therapy to determine the therapeutically achieved target dose and its coefficient of variation. There was a significant dose dependency in therapeutic outcome: frequency of hypothyroidism increased from 27.4% after 150 Gy to 67.7% after 300 Gy, while the frequency of persistent hyperthyroidism decreased from 27.4% after 150 Gy to 8.1% after 300 Gy. Patients who became hypothyroid had a maximum thyroid volume of 42 ml and received a target dose of 256{+-}80 Gy. The coefficient of variation for the achieved target dose ranged between 27.7% for 150 Gy and 17.8% for 300 Gy. When analysing further factors which might influence therapeutic outcome, only pre-treatment thyroid volume showed a significant relationship to the result of treatment. It is concluded that a target dose of 250 Gy is essential to achieve hypothyroidism within 1 year after radioiodine therapy in Graves' disease patients with goitres up to 40 ml in volume. Patients with larger goitres might need higher doses
Fortenberry, Ryan C.; Huang, Xinchuan; Crawford, T. Daniel; Lee, Timothy J.
2013-01-01
It has been shown that rotational lines observed in the Horsehead nebula photon-dominated-region (PDR) are probably not caused by l-C3H+, as was originally suggested. In the search for viable alternative candidate carriers, quartic force fields are employed here to provide highly accurate rotational constants, as well as fundamental vibrational frequencies, for another candidate carrier: 1 (sup 1)A' C3H(-). The ab initio computed spectroscopic constants provided in this work are, compared to those necessary to define the observed lines, as accurate as the computed spectroscopic constants for many of the known interstellar anions. Additionally, the computed D-eff for C3H(-) is three times closer to the D deduced from the observed Horsehead nebula lines relative to l-C3H(+). As a result, 1 (sup 1)A' C3H(-). is a more viable candidate for these observed rotational transitions and would be the seventh confirmed interstellar anion detected within the past decade and the first C(sub n)H(-) molecular anion with an odd n.
Stability constants of scandium complexes, 1
International Nuclear Information System (INIS)
Itoh, Hisako; Itoh, Naomi; Suzuki, Yasuo
1984-01-01
The stability constants of scandium complexes with some carboxylate ligands were determined potentiometrically at 25.0 and 40.0 0 C and at an ionic strength of 0.10 with potassium nitrate as supporting electrolyte. The constants of the scandium complexes were appreciably greater than those of the corresponding lanthanoid complexes, as expected. The changes in free energy, enthalpy, and entropy for the formation of the scandium complexes were calculated from the stability constants at two temperatures. (author)
Dose rate constants for new dose quantities
International Nuclear Information System (INIS)
Tschurlovits, M.; Daverda, G.; Leitner, A.
1992-01-01
Conceptual changes and new quantities made is necessary to reassess dose rate quantities. Calculations of the dose rate constant were done for air kerma, ambient dose equivalent and directional dose equivalent. The number of radionuclides is more than 200. The threshold energy is selected as 20 keV for the dose equivalent constants. The dose rate constant for the photon equivalent dose as used mainly in German speaking countries as a temporary quantity is also included. (Author)
Rha, Koon H; Abdel Raheem, Ali; Park, Sung Y; Kim, Kwang H; Kim, Hyung J; Koo, Kyo C; Choi, Young D; Jung, Byung H; Lee, Sang K; Lee, Won K; Krishnan, Jayram; Shin, Tae Y; Cho, Jin-Seon
2017-11-01
To assess the correlation of the resected and ischaemic volume (RAIV), which is a preoperatively calculated volume of nephron loss, with the amount of postoperative renal function (PRF) decline after minimally invasive partial nephrectomy (PN) in a multi-institutional dataset. We identified 348 patients from March 2005 to December 2013 at six institutions. Data on all cases of laparoscopic (n = 85) and robot-assisted PN (n = 263) performed were retrospectively gathered. Univariable and multivariable linear regression analyses were used to identify the associations between various time points of PRF and the RAIV, as a continuous variable. The mean (sd) RAIV was 24.2 (29.2) cm 3 . The mean preoperative estimated glomerular filtration rate (eGFR) and the eGFRs at postoperative day 1, 6 and 36 months after PN were 91.0 and 76.8, 80.2 and 87.7 mL/min/1.73 m 2 , respectively. In multivariable linear regression analysis, the amount of decline in PRF at follow-up was significantly correlated with the RAIV (β 0.261, 0.165, 0.260 at postoperative day 1, 6 and 36 months after PN, respectively). This study has the limitation of its retrospective nature. Preoperatively calculated RAIV significantly correlates with the amount of decline in PRF during long-term follow-up. The RAIV could lead our research to the level of prediction of the amount of PRF decline after PN and thus would be appropriate for assessing the technical advantages of emerging techniques. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.
A stringy nature needs just two constants
International Nuclear Information System (INIS)
Veneziano, G.
1986-01-01
Dual string theories of everything, being purely geometrical, contain only two fundamental constants: c, for relativistic invariance, and a length lambda, for quantization. Planck's and Newton's constants appear only through Planck's length, a ''calculable'' fraction of lambda. Only the existence of a light sector breaks a ''reciprocity'' principle and unification at lambda, which is also the theory's cut-off
Hydrolysis and formation constants at 250C
International Nuclear Information System (INIS)
Phillips, S.L.
1982-05-01
A database consisting of hydrolysis and formation constants for about 20 metals associated with the disposal of nuclear waste is given. Complexing ligands for the various ionic species of these metals include OH, F, Cl, SO 4 , PO 4 and CO 3 . Table 1 consists of tabulated calculated and experimental values of log K/sub xy/, mainly at 25 0 C and various ionic strengths together with references to the origin of the data. Table 2 consists of a column of recommended stability constants at 25 0 C and zero ionic strength tabulated in the column headed log K/sub xy/(0); other columns contain coefficients for an extended Debye-Huckel equation to permit calculations of stability constants up to 3 ionic strength, and up to 0.7 ionic strength using the Davies equation. Selected stability constants calculated with these coefficients for various ionic strengths agree to an average of +- 2% when compared with published experimental and calculated values
Indian Academy of Sciences (India)
IAS Admin
The article discusses the importance of the fine structure constant in quantum mechanics, along with the brief history of how it emerged. Al- though Sommerfelds idea of elliptical orbits has been replaced by wave mechanics, the fine struc- ture constant he introduced has remained as an important parameter in the field of ...
Directory of Open Access Journals (Sweden)
Alicia Gauffin
2018-05-01
Full Text Available On the basis of the Volume Correlation Model (VCM as well as data on steel consumption and scrap collection per industry sector (construction, automotive, industrial goods, and consumer goods, it was possible to estimate service lifetimes of steel in the United States between 1900 and 2016. Input data on scrap collection per industry sector was based on a scrap survey conducted by the World Steel Association for a static year in 2014 in the United States. The lifetimes of steel calculated with the VCM method were within the range of previously reported measured lifetimes of products and applications for all industry sectors. Scrapped (and apparent lifetimes of steel compared with measured lifetimes were calculated to be as follows: a scrapped lifetime of 29 years for the construction sector (apparent lifetime: 52 years compared with 44 years measured in 2014. Industrial goods: 16 (27 years compared with 19 years measured in 2010. Consumer goods: 12 (14 years compared with 13 years measured in 2014. Automotive sector: 14 (19 years compared with 17 years measured in 2011. Results show that the VCM can estimate reasonable values of scrap collection and availability per industry sector over time.
Cosmological constants and variations
International Nuclear Information System (INIS)
Barrow, John D
2005-01-01
We review properties of theories for the variation of the gravitation and fine structure 'constants'. We highlight some general features of the cosmological models that exist in these theories with reference to recent quasar data that is consistent with time-variation in the fine structure 'constant' since a redshift of 3.5. The behaviour of a simple class of varying alpha cosmologies is outlined in the light of all the observational constraints. We also discuss some of the consequences of varying 'constants' for oscillating universes and show by means of exact solutions that they appear to evolve monotonically in time even though the scale factor of the universe oscillates
On the constant-roll inflation
Yi, Zhu; Gong, Yungui
2018-03-01
The primordial power spectra of scalar and tensor perturbations during slow-roll inflation are usually calculated with the method of Bessel function approximation. For constant-roll or ultra slow-roll inflation, the method of Bessel function approximation may be invalid. We compare the numerical results with the analytical results derived from the Bessel function approximation, and we find that they differ significantly on super-horizon scales if the constant slow-roll parameter ηH is not small. More accurate method is needed for calculating the primordial power spectrum for constant-roll inflation.
Reactor group constants and benchmark test
Energy Technology Data Exchange (ETDEWEB)
Takano, Hideki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
2001-08-01
The evaluated nuclear data files such as JENDL, ENDF/B-VI and JEF-2 are validated by analyzing critical mock-up experiments for various type reactors and assessing applicability for nuclear characteristics such as criticality, reaction rates, reactivities, etc. This is called Benchmark Testing. In the nuclear calculations, the diffusion and transport codes use the group constant library which is generated by processing the nuclear data files. In this paper, the calculation methods of the reactor group constants and benchmark test are described. Finally, a new group constants scheme is proposed. (author)
The cosmological constant problem
International Nuclear Information System (INIS)
Dolgov, A.D.
1989-05-01
A review of the cosmological term problem is presented. Baby universe model and the compensating field model are discussed. The importance of more accurate data on the Hubble constant and the Universe age is stressed. 18 refs
Meulemans, O.
A new method of calculating the percentages of serum protein is discussed. This method has a smaller distribution curve than the factor that is generally used for the correction of the extinction of the albumin fraction obtained with the elution method. The magnitude of the new factor is 1.22 ±
CODATA recommended values of the fundamental constants
International Nuclear Information System (INIS)
Mohr, Peter J.; Taylor, Barry N.
2000-01-01
A review is given of the latest Committee on Data for Science and Technology (CODATA) adjustment of the values of the fundamental constants. The new set of constants, referred to as the 1998 values, replaces the values recommended for international use by CODATA in 1986. The values of the constants, and particularly the Rydberg constant, are of relevance to the calculation of precise atomic spectra. The standard uncertainty (estimated standard deviation) of the new recommended value of the Rydberg constant, which is based on precision frequency metrology and a detailed analysis of the theory, is approximately 1/160 times the uncertainty of the 1986 value. The new set of recommended values as well as a searchable bibliographic database that gives citations to the relevant literature is available on the World Wide Web at physics.nist.gov/constants and physics.nist.gov/constantsbib, respectively
Zero cosmological constant from normalized general relativity
International Nuclear Information System (INIS)
Davidson, Aharon; Rubin, Shimon
2009-01-01
Normalizing the Einstein-Hilbert action by the volume functional makes the theory invariant under constant shifts in the Lagrangian. The associated field equations then resemble unimodular gravity whose otherwise arbitrary cosmological constant is now determined as a Machian universal average. We prove that an empty space-time is necessarily Ricci tensor flat, and demonstrate the vanishing of the cosmological constant within the scalar field paradigm. The cosmological analysis, carried out at the mini-superspace level, reveals a vanishing cosmological constant for a universe which cannot be closed as long as gravity is attractive. Finally, we give an example of a normalized theory of gravity which does give rise to a non-zero cosmological constant.
Energy Technology Data Exchange (ETDEWEB)
Zhen, X; Chen, H; Liao, Y; Zhou, L [Southern Medical University, Guangzhou, Guangdong (China); Hrycushko, B; Albuquerque, K; Gu, X [UT Southwestern Medical Center, Dallas, TX (United States)
2016-06-15
Purpose: To study the feasibility of employing deformable registration methods for accurate rectum dose volume parameters calculation and their potentials in revealing rectum dose-toxicity between complication and non-complication cervical cancer patients with brachytherapy treatment. Method and Materials: Data from 60 patients treated with BT including planning images, treatment plans, and follow-up clinical exam were retrospectively collected. Among them, 12 patients complained about hematochezia were further examined with colonoscopy and scored as Grade 1–3 complication (CP). Meanwhile, another 12 non-complication (NCP) patients were selected as a reference group. To seek for potential gains in rectum toxicity prediction when fractional anatomical deformations are account for, the rectum dose volume parameters D0.1/1/2cc of the selected patients were retrospectively computed by three different approaches: the simple “worstcase scenario” (WS) addition method, an intensity-based deformable image registration (DIR) algorithm-Demons, and a more accurate, recent developed local topology preserved non-rigid point matching algorithm (TOP). Statistical significance of the differences between rectum doses of the CP group and the NCP group were tested by a two-tailed t-test and results were considered to be statistically significant if p < 0.05. Results: For the D0.1cc, no statistical differences are found between the CP and NCP group in all three methods. For the D1cc, dose difference is not detected by the WS method, however, statistical differences between the two groups are observed by both Demons and TOP, and more evident in TOP. For the D2cc, the CP and NCP cases are statistically significance of the difference for all three methods but more pronounced with TOP. Conclusion: In this study, we calculated the rectum D0.1/1/2cc by simple WS addition and two DIR methods and seek for gains in rectum toxicity prediction. The results favor the claim that accurate dose
Transport equivalent diffusion constants for reflector region in PWRs
International Nuclear Information System (INIS)
Tahara, Yoshihisa; Sekimoto, Hiroshi
2002-01-01
The diffusion-theory-based nodal method is widely used in PWR core designs for reason of its high computing speed in three-dimensional calculations. The baffle/reflector (B/R) constants used in nodal calculations are usually calculated based on a one-dimensional transport calculation. However, to achieve high accuracy of assembly power prediction, two-dimensional model is needed. For this reason, the method for calculating transport equivalent diffusion constants of reflector material was developed so that the neutron currents on the material boundaries could be calculated exactly in diffusion calculations. Two-dimensional B/R constants were calculated using the transport equivalent diffusion constants in the two-dimensional diffusion calculation whose geometry reflected the actual material configuration in the reflector region. The two-dimensional B/R constants enabled us to predict assembly power within an error of 1.5% at hot full power conditions. (author)
1995-08-01
about the distances to galaxies and thereby about the expansion rate of the Universe. A simple way to determine the distance to a remote galaxy is by measuring its redshift, calculate its velocity from the redshift and divide this by the Hubble constant, H0. For instance, the measured redshift of the parent galaxy of SN 1995K (0.478) yields a velocity of 116,000 km/sec, somewhat more than one-third of the speed of light (300,000 km/sec). From the universal expansion rate, described by the Hubble constant (H0 = 20 km/sec per million lightyears as found by some studies), this velocity would indicate a distance to the supernova and its parent galaxy of about 5,800 million lightyears. The explosion of the supernova would thus have taken place 5,800 million years ago, i.e. about 1,000 million years before the solar system was formed. However, such a simple calculation works only for relatively ``nearby'' objects, perhaps out to some hundred million lightyears. When we look much further into space, we also look far back in time and it is not excluded that the universal expansion rate, i.e. the Hubble constant, may have been different at earlier epochs. This means that unless we know the change of the Hubble constant with time, we cannot determine reliable distances of distant galaxies from their measured redshifts and velocities. At the same time, knowledge about such change or lack of the same will provide unique information about the time elapsed since the Universe began to expand (the ``Big Bang''), that is, the age of the Universe and also its ultimate fate. The Deceleration Parameter q0 Cosmologists are therefore eager to determine not only the current expansion rate (i.e., the Hubble constant, H0) but also its possible change with time (known as the deceleration parameter, q0). Although a highly accurate value of H0 has still not become available, increasing attention is now given to the observational determination of the second parameter, cf. also the Appendix at the
Computing the Gromov hyperbolicity constant of a discrete metric space
Ismail, Anas
2012-01-01
, and many other areas of research. The Gromov hyperbolicity constant of several families of graphs and geometric spaces has been determined. However, so far, the only known algorithm for calculating the Gromov hyperbolicity constant δ of a discrete metric
Directory of Open Access Journals (Sweden)
Jacques H Abraini
2017-01-01
Full Text Available The noble gases xenon (Xe and helium (He are known to possess neuroprotective properties. Xe is considered the golden standard neuroprotective gas. However, Xe has a higher molecular weight and lower thermal conductivity and specific heat than those of nitrogen, the main diluent of oxygen (O2 in air, conditions that could impair or at least reduce the intrinsic neuroprotective properties of Xe by increasing the critical care patient's respiratory workload and body temperature. In contrast, He has a lower molecular weight and higher thermal conductivity and specific heat than those of nitrogen, but is unfortunately far less potent than Xe at providing neuroprotection. Therefore, combining Xe with He could allow obtaining, depending on the gas inhalation temperature and composition, gas mixtures with neutral or hypothermic properties, the latter being advantageous in term of neuroprotection. However, calculating the thermal properties of a mixture, whatever the substances – gases, metals, rubbers, etc. – is not trivial. To answer this question, we provide a graphical method to assess the volume proportions of Xe, He and O2 that a gas mixture should contain, and the inhalation temperature to which it should be administered to allow a clinician to maintain the patient at a target body temperature.
Cody, Regina J.; Romani, Paul N.; Nesbitt, Fred L.; Iannone, Mark A.; Tardy, Dwight C.; Stief, Louis J.
2003-01-01
The column abundances of CH3 observed by the Infrared Space Observatory (ISO) satellite on Saturn and Neptune were lower than predicted by atmospheric photochemical models, especially for Saturn. It has been suggested that the models underestimated the loss of CH3 due to poor knowledge of the rate constant k of the CH3 + CH3 self-reaction at the low temperatures and pressures of these atmospheres. Motivated by this suggestion, we undertook a combined experimental and photochemical modeling study of the CH3 + CH3 reaction and its role in determining planetary CH3 abundances. In a discharge flow-mass spectrometer system, k was measured at T = 155 K and three pressures of He. The results in units of cu cm/molecule/s are k(0.6 Torr) = 6.82 x 10(exp -11), k(1.0 Torr) = 6.98 x 10(exp -11), and k(1.5 Torr) = 6.91 x 10(exp -11). Analytical expressions for k were derived that (1) are consistent with the present laboratory data at T = 155 K, our previous data at T = 202 K and 298 K, and those of other studies in He at T = 296-298 K and (2) have some theoretical basis to provide justification for extrapolation. The derived analytical expressions were then used in atmospheric photochemical models for both Saturn and Neptune. These model results reduced the disparity with observations of Saturn, but not with observations of Neptune. However, the disparity for Neptune is much smaller. The solution to the remaining excess CH3 prediction in the models relative to the ISO observations lies, to a large extent, elsewhere in the CH3 photochemistry or transport, not in the CH3 + CH3 rate.
International Nuclear Information System (INIS)
Chandra, R.
1977-01-01
On the grounds of the two correspondence limits, the Newtonian limit and the special theory limit of Einstein field equations, a modification of the cosmical constant has been proposed which gives realistic results in the case of a homogeneous universe. Also, according to this modification an explanation for the negative pressure in the steady-state model of the universe has been given. (author)
International Nuclear Information System (INIS)
Weinberg, S.
1989-01-01
Cosmological constant problem is discussed. History of the problem is briefly considered. Five different approaches to solution of the problem are described: supersymmetry, supergravity, superstring; anthropic approach; mechamism of lagrangian alignment; modification of gravitation theory and quantum cosmology. It is noted that approach, based on quantum cosmology is the most promising one
International Nuclear Information System (INIS)
O Murchadha, N.
1991-01-01
The set of riemannian three-metrics with positive Yamabe constant defines the space of independent data for the gravitational field. The boundary of this set is investigated, and it is shown that metrics close to the boundary satisfy the positive-energy theorem. (Author) 18 refs
Elastic constants of stressed and unstressed materials in the phase-field crystal model
Wang, Zi-Le; Huang, Zhi-Feng; Liu, Zhirong
2018-04-01
A general procedure is developed to investigate the elastic response and calculate the elastic constants of stressed and unstressed materials through continuum field modeling, particularly the phase-field crystal (PFC) models. It is found that for a complete description of system response to elastic deformation, the variations of all the quantities of lattice wave vectors, their density amplitudes (including the corresponding anisotropic variation and degeneracy breaking), the average atomic density, and system volume should be incorporated. The quantitative and qualitative results of elastic constant calculations highly depend on the physical interpretation of the density field used in the model, and also importantly, on the intrinsic pressure that usually pre-exists in the model system. A formulation based on thermodynamics is constructed to account for the effects caused by constant pre-existing stress during the homogeneous elastic deformation, through the introducing of a generalized Gibbs free energy and an effective finite strain tensor used for determining the elastic constants. The elastic properties of both solid and liquid states can be well produced by this unified approach, as demonstrated by an analysis for the liquid state and numerical evaluations for the bcc solid phase. The numerical calculations of bcc elastic constants and Poisson's ratio through this method generate results that are consistent with experimental conditions, and better match the data of bcc Fe given by molecular dynamics simulations as compared to previous work. The general theory developed here is applicable to the study of different types of stressed or unstressed material systems under elastic deformation.
Production in constant evolution
International Nuclear Information System (INIS)
Lozano, T.
2009-01-01
The Cofrentes Nuclear Power Plant now has 25 years of operation behind it: a quarter century adding value and demonstrating the reasons why it is one of the most important energy producing facilities in the Spanish power market. Particularly noteworthy is the enterprising spirit of the plant, which has strived to continuously improve with the large number of modernization projects that it has undertaken over the past 25 years. The plant has constantly evolved thanks to the amount of investments made to improve safety and reliability and the perseverance to stay technologically up to date. Efficiency, training and teamwork have been key to the success of the plant over these 25 years of constant change and progress. (Author)
International Nuclear Information System (INIS)
Blake, J.B.; Dearborn, D.S.P.
1979-01-01
Small fluctuations in the solar constant can occur on timescales much shorter than the Kelvin time. Changes in the ability of convection to transmit energy through the superadiabatic and transition regions of the convection zone cause structure adjustments which can occur on a time scale of days. The bulk of the convection zone reacts to maintain hydrostatic equilibrium (though not thermal equilibrium) and causes a luminosity change. While small radius variations will occur, most of the change will be seen in temperature
Stabilized power constant alimentation
International Nuclear Information System (INIS)
Roussel, L.
1968-06-01
The study and realization of a stabilized power alimentation variable from 5 to 100 watts are described. In order to realize a constant power drift of Lithium compensated diodes, we have searched a 1 per cent precision of regulation and a response time minus than 1 sec. Recent components like Hall multiplicator and integrated amplifiers give this possibility and it is easy to use permutable circuits. (author) [fr
Connecting Fundamental Constants
International Nuclear Information System (INIS)
Di Mario, D.
2008-01-01
A model for a black hole electron is built from three basic constants only: h, c and G. The result is a description of the electron with its mass and charge. The nature of this black hole seems to fit the properties of the Planck particle and new relationships among basic constants are possible. The time dilation factor in a black hole associated with a variable gravitational field would appear to us as a charge; on the other hand the Planck time is acting as a time gap drastically limiting what we are able to measure and its dimension will appear in some quantities. This is why the Planck time is numerically very close to the gravitational/electric force ratio in an electron: its difference, disregarding a π√(2) factor, is only 0.2%. This is not a coincidence, it is always the same particle and the small difference is between a rotating and a non-rotating particle. The determination of its rotational speed yields accurate numbers for many quantities, including the fine structure constant and the electron magnetic moment
Directory of Open Access Journals (Sweden)
Neal Jackson
2015-09-01
Full Text Available I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first uses individual astrophysical objects which have some property that allows their intrinsic luminosity or size to be determined, or allows the determination of their distance by geometric means. The second category comprises the use of all-sky cosmic microwave background, or correlations between large samples of galaxies, to determine information about the geometry of the Universe and hence the Hubble constant, typically in a combination with other cosmological parameters. Many, but not all, object-based measurements give H_0 values of around 72–74 km s^–1 Mpc^–1, with typical errors of 2–3 km s^–1 Mpc^–1. This is in mild discrepancy with CMB-based measurements, in particular those from the Planck satellite, which give values of 67–68 km s^–1 Mpc^–1 and typical errors of 1–2 km s^–1 Mpc^–1. The size of the remaining systematics indicate that accuracy rather than precision is the remaining problem in a good determination of the Hubble constant. Whether a discrepancy exists, and whether new physics is needed to resolve it, depends on details of the systematics of the object-based methods, and also on the assumptions about other cosmological parameters and which datasets are combined in the case of the all-sky methods.
International Nuclear Information System (INIS)
Cullen, D.E.
1979-01-01
A code, SIGMAL, to Doppler-broaden evaluated cross sections in the ENDL format was designed. This code can Doppler-broaden cross sections that result from neutrons, protons, deuterons, tritons, 3 He, or alpha particles incident on any target nuclei. The code allows broadening to up to 100 final temperatures, either directly from the initial temperature or by bootstrapping to successively higher temperatures. 6 figures, 2 tables
International Nuclear Information System (INIS)
Howerton, R.J.
1976-01-01
The LLL evaluated nuclear data library (ENDL) has been translated into the evaluated neutron data file/version B (ENDF/B) format. This translation is for the convenience of those who wish to use ENDL data but who are more familiar with ENDF/B formats and procedures. Only that portion of ENDL dealing with neutron-induced interactions (including photon production from neutron-induced reactions) has been translated
International Nuclear Information System (INIS)
Willson, R.C.; Hudson, H.
1984-01-01
The Active Cavity Radiometer Irradiance Monitor (ACRIM) of the Solar Maximum Mission satellite measures the radiant power emitted by the sun in the direction of the earth and has worked flawlessly since 1980. The main motivation for ACRIM's use to measure the solar constant is the determination of the extent to which this quantity's variations affect earth weather and climate. Data from the solar minimum of 1986-1987 is eagerly anticipated, with a view to the possible presence of a solar cycle variation in addition to that caused directly by sunspots
Nuclear magnetic resonance J coupling constant polarizabilities of hydrogen peroxide
DEFF Research Database (Denmark)
Kjær, Hanna; Nielsen, Monia R.; Pagola, Gabriel I.
2012-01-01
In this paper we present the so far most extended investigation of the calculation of the coupling constant polarizability of a molecule. The components of the coupling constant polarizability are derivatives of the NMR indirect nuclear spin-spin coupling constant with respect to an external elec...
Three-body interactions and the elastic constants of hcp solid 4He
Barnes, Ashleigh L.; Hinde, Robert J.
2017-09-01
The effect of three-body interactions on the elastic properties of hexagonal close packed solid 4He is investigated using variational path integral (VPI) Monte Carlo simulations. The solid's nonzero elastic constants are calculated, at T = 0 K and for a range of molar volumes from 7.88 cm3/mol to 20.78 cm3/mol, from the bulk modulus and the three pure shear constants C0, C66, and C44. Three-body interactions are accounted for using our recently reported perturbative treatment based on the nonadditive three-body potential of Cencek et al. Previous studies have attempted to account for the effect of three-body interactions on the elastic properties of solid 4He; however, these calculations have treated zero point motions using either the Einstein or Debye approximations, which are insufficient in the molar volume range where solid 4He is characterized as a quantum solid. Our VPI calculations allow for a more accurate treatment of the zero point motions which include atomic correlation. From these calculations, we find that agreement with the experimental bulk modulus is significantly improved when three-body interactions are considered. In addition, three-body interactions result in non-negligible differences in the calculated pure shear constants and nonzero elastic constants, particularly at higher densities, where differences of up to 26.5% are observed when three-body interactions are included. We compare to the available experimental data and find that our results are generally in as good or better agreement with experiment as previous theoretical investigations.
Finite volume at two-loops in chiral perturbation theory
International Nuclear Information System (INIS)
Bijnens, Johan; Rössler, Thomas
2015-01-01
We calculate the finite volume corrections to meson masses and decay constants in two and three flavour Chiral Perturbation Theory to two-loop order. The analytical results are compared with the existing result for the pion mass in two-flavour ChPT and the partial results for the other quantities. We present numerical results for all quantities.
Some aspects of preparation and testing of group constants group constant system ABBN-90
International Nuclear Information System (INIS)
Nikolaev, M.N.; Tsiboulia, A.M.; Manturov, G.N.
1996-01-01
This paper presents an overview of activities performed to prepare and test the group constants ABBN-90. The ABBN-90 set is designed for application calculations of fast, intermediate and thermal nuclear reactors. The calculations of subgroup parameters are discussed. The processing code system GRUCON is mentioned in comparison to the NJOY code system. Proposals are made for future activities. (author). Figs, tabs
Institute of Scientific and Technical Information of China (English)
田爱琴; 孙洪博; 陈文涛; 王琳
2012-01-01
Based on vapor-liquid phase equilibria data for CO2+2-butanol binary system from 323K to 353K by constant-volume visual high-pressure cell, the solubility model of CO2 in 2-butanol was established with Krichevsky-Kasarnovsky equation. Henry's coefficients and partial molar volumes of CO2 at infinite dilution were calculated. Meanwhile, Partial molar volumes of CO2 and 2-butanol at equilibrium were calculated from partial molar volumes properties together with Peng-Robinson equation of state and Van der Waals-2 mixed rule. The results showed that Henry's coefficients and partial molar volumes of CO2 at infinite dilution were both the function of temperature, and Henry's coefficients decreased with temperature. The partial molar volumes of CO2 at infinite dilution were negative and the magnitudes decreased with temperature. The calculated effects of partial molar volumes of vapor and liquid phase at equilibrium showed that the partial molar volumes of CO2 and 2-butanol in liquid phase were positive, but in vapor the partial molar volumes of CO2 were negative and the partial molar volumes of 2-butanol were positive. The research provided theoretical basis for deciding supercritical extraction conditions and instructing industrial production.%利用固定体积可视高压釜测量出的在323 K～353 K温度范围内的CO2与2-丁醇二元体系在高压下的汽液相平衡数据,根据Krichevsky-Kasarnovsky方程建立了CO2在液相中的溶解度模型,得到了该二元体系在高压下的亨利系数和CO2在无限稀释溶液中的偏摩尔体积等性质.同时根据偏摩尔体积性质和Peng-Robinson状态方程及Van der Waals-2混合规则来计算该体系在平衡状态下的气、液相的偏摩尔体积.结果表明CO2在2-丁醇中的亨利系数和CO2在无限稀释溶液中的偏摩尔体积均为温度的函数,CO2在2-丁醇中的亨利系数随温度的升高而降低.CO2在无限稀释溶液中的偏摩尔体积(V)1∞在研究温度下均为
International Nuclear Information System (INIS)
Kaneko, Kyouichi; Akutsu, Yasushi; Kodama, Yusuke
2010-01-01
We investigated whether right atrial (RA) volume could be used to predict the recurrence of atrial fibrillation (AF) after pulmonary vein catheter ablation (CA). We evaluated 65 patients with paroxysmal AF (mean age, 60+10 years, 81.5% male) and normal volunteers (57±14 years, 41.7% male). Sixty-four-slice multi-detector computed tomography was performed for left atrial (LA) and RA volume estimations before CA. The recurrence of AF was assessed for 6 months after the ablation. Both left and right atrial volumes were larger in the AF patients than the normal volunteers (LA: 99.7+33.2 ml vs. 59.7+17.4 ml; RA: 82.9+35.7 ml vs. 43.9+12 ml; P 100 ml) for predicting the recurrence of AF was 81.3% in 13 of 16 patients with AF recurrence, and the specificity was 69.4% in 34 of 49 patients without recurrence. The sensitivity with large RA volumes (>87 ml) was 81.3% in 13 of 16 patients with AF recurrence, and the specificity was 75.5% in 37 of 49 patients without recurrence. RA volume is a useful predictor of the recurrence of AF, similar to LA volume. (author)
Bessette-Kirton, Erin; Coe, Jeffrey A.; Zhou, Wendy
2018-01-01
The use of preevent and postevent digital elevation models (DEMs) to estimate the volume of rock avalanches on glaciers is complicated by ablation of ice before and after the rock avalanche, scour of material during rock avalanche emplacement, and postevent ablation and compaction of the rock avalanche deposit. We present a model to account for these processes in volume estimates of rock avalanches on glaciers. We applied our model by calculating the volume of the 28 June 2016 Lamplugh rock avalanche in Glacier Bay National Park, Alaska. We derived preevent and postevent 2‐m resolution DEMs from WorldView satellite stereo imagery. Using data from DEM differencing, we reconstructed the rock avalanche and adjacent surfaces at the time of occurrence by accounting for elevation changes due to ablation and scour of the ice surface, and postevent deposit changes. We accounted for uncertainties in our DEMs through precise coregistration and an assessment of relative elevation accuracy in bedrock control areas. The rock avalanche initially displaced 51.7 ± 1.5 Mm3 of intact rock and then scoured and entrained 13.2 ± 2.2 Mm3 of snow and ice during emplacement. We calculated the total deposit volume to be 69.9 ± 7.9 Mm3. Volume estimates that did not account for topographic changes due to ablation, scour, and compaction underestimated the deposit volume by 31.0–46.8 Mm3. Our model provides an improved framework for estimating uncertainties affecting rock avalanche volume measurements in glacial environments. These improvements can contribute to advances in the understanding of rock avalanche hazards and dynamics.
Chandra Independently Determines Hubble Constant
2006-08-01
A critically important number that specifies the expansion rate of the Universe, the so-called Hubble constant, has been independently determined using NASA's Chandra X-ray Observatory. This new value matches recent measurements using other methods and extends their validity to greater distances, thus allowing astronomers to probe earlier epochs in the evolution of the Universe. "The reason this result is so significant is that we need the Hubble constant to tell us the size of the Universe, its age, and how much matter it contains," said Max Bonamente from the University of Alabama in Huntsville and NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., lead author on the paper describing the results. "Astronomers absolutely need to trust this number because we use it for countless calculations." Illustration of Sunyaev-Zeldovich Effect Illustration of Sunyaev-Zeldovich Effect The Hubble constant is calculated by measuring the speed at which objects are moving away from us and dividing by their distance. Most of the previous attempts to determine the Hubble constant have involved using a multi-step, or distance ladder, approach in which the distance to nearby galaxies is used as the basis for determining greater distances. The most common approach has been to use a well-studied type of pulsating star known as a Cepheid variable, in conjunction with more distant supernovae to trace distances across the Universe. Scientists using this method and observations from the Hubble Space Telescope were able to measure the Hubble constant to within 10%. However, only independent checks would give them the confidence they desired, considering that much of our understanding of the Universe hangs in the balance. Chandra X-ray Image of MACS J1149.5+223 Chandra X-ray Image of MACS J1149.5+223 By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion
Slab-diffusion approximation from time-constant-like calculations
International Nuclear Information System (INIS)
Johnson, R.W.
1976-12-01
Two equations were derived which describe the quantity and any fluid diffused from a slab as a function of time. One equation is applicable to the initial stage of the process; the other to the final stage. Accuracy is 0.2 percent at the one point where both approximations apply and where accuracy of either approximation is the poorest. Characterizing other rate processes might be facilitated by the use of the concept of NOLOR (normal of the logarithm of the rate) and its time dependence
Determination of constants of factorized pairing force from conservation laws
International Nuclear Information System (INIS)
Voronkov, Yu.P.; Mikhajlov, V.M.
1975-01-01
The constants of a factorized interaction in the particle-particle channel are evaluated on the basis of average field parameters and Cooper pairing. The relations between the constants of multipole particle-particle forces are derived for the spherical nuclei. The constants of the quadrupole pairing are obtained for deformed nuclei from the angular momentum conservation law. The calculated constants are compared with empiricalones
On determining dose rate constants spectroscopically
International Nuclear Information System (INIS)
Rodriguez, M.; Rogers, D. W. O.
2013-01-01
Purpose: To investigate several aspects of the Chen and Nath spectroscopic method of determining the dose rate constants of 125 I and 103 Pd seeds [Z. Chen and R. Nath, Phys. Med. Biol. 55, 6089–6104 (2010)] including the accuracy of using a line or dual-point source approximation as done in their method, and the accuracy of ignoring the effects of the scattered photons in the spectra. Additionally, the authors investigate the accuracy of the literature's many different spectra for bare, i.e., unencapsulated 125 I and 103 Pd sources. Methods: Spectra generated by 14 125 I and 6 103 Pd seeds were calculated in vacuo at 10 cm from the source in a 2.7 × 2.7 × 0.05 cm 3 voxel using the EGSnrc BrachyDose Monte Carlo code. Calculated spectra used the initial photon spectra recommended by AAPM's TG-43U1 and NCRP (National Council of Radiation Protection and Measurements) Report 58 for the 125 I seeds, or TG-43U1 and NNDC(2000) (National Nuclear Data Center, 2000) for 103 Pd seeds. The emitted spectra were treated as coming from a line or dual-point source in a Monte Carlo simulation to calculate the dose rate constant. The TG-43U1 definition of the dose rate constant was used. These calculations were performed using the full spectrum including scattered photons or using only the main peaks in the spectrum as done experimentally. Statistical uncertainties on the air kerma/history and the dose rate/history were ⩽0.2%. The dose rate constants were also calculated using Monte Carlo simulations of the full seed model. Results: The ratio of the intensity of the 31 keV line relative to that of the main peak in 125 I spectra is, on average, 6.8% higher when calculated with the NCRP Report 58 initial spectrum vs that calculated with TG-43U1 initial spectrum. The 103 Pd spectra exhibit an average 6.2% decrease in the 22.9 keV line relative to the main peak when calculated with the TG-43U1 rather than the NNDC(2000) initial spectrum. The measured values from three different
Massa, Enrico; Nicolaus, Arnold
2011-04-01
This issue of Metrologia collects papers about the results of an international research project aimed at the determination of the Avogadro constant, NA, by counting the atoms in a silicon crystal highly enriched with the isotope 28Si. Fifty years ago, Egidi [1] thought about realizing an atomic mass standard. In 1965, Bonse and Hart [2] operated the first x-ray interferometer, thus paving the way to the achievement of Egidi's dream, and soon Deslattes et al [3] completed the first counting of the atoms in a natural silicon crystal. The present project, outlined by Zosi [4] in 1983, began in 2004 by combining the experiences and capabilities of the BIPM, INRIM, IRMM, NIST, NPL, NMIA, NMIJ and PTB. The start signal, ratified by a memorandum of understanding, was a contract for the production of a silicon crystal highly enriched with 28Si. The enrichment process was undertaken by the Central Design Bureau of Machine Building in St Petersburg. Subsequently, a polycrystal was grown in the Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences in Nizhny Novgorod and a 28Si boule was grown and purified by the Leibniz-Institut für Kristallzüchtung in Berlin. Isotope enrichment made it possible to apply isotope dilution mass spectroscopy, to determine the Avogadro constant with unprecedented accuracy, and to fulfil Egidi's dream. To convey Egidi's 'fantasy' into practice, two 28Si kilogram prototypes shaped as quasi-perfect spheres were manufactured by the Australian Centre for Precision Optics; their isotopic composition, molar mass, mass, volume, density and lattice parameter were accurately determined and their surfaces were chemically and physically characterized at the atomic scale. The paper by Andreas et al reviews the work carried out; it collates all the findings and illustrates how Avogadro's constant was obtained. Impurity concentration and gradients in the enriched crystal were measured by infrared spectroscopy and taken into
Energy Technology Data Exchange (ETDEWEB)
Rojas C, E. L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)
2008-07-01
The objective of this study is to investigate the changes observed in the absorbed doses in mammary gland tissue when irradiated with a equipment of high dose rate known as Mammosite and introducing material resources contrary to the tissue that constitutes the mammary gland. The modeling study is performed with the code MCNPX, 2005 version, the equipment and the mammary gland and calculating the absorbed doses in tissue when introduced small volumes of air or calcium in the system. (Author)
RNA structure and scalar coupling constants
Energy Technology Data Exchange (ETDEWEB)
Tinoco, I. Jr.; Cai, Z.; Hines, J.V.; Landry, S.M.; SantaLucia, J. Jr.; Shen, L.X.; Varani, G. [Univ. of California, Berkeley, CA (United States)
1994-12-01
Signs and magnitudes of scalar coupling constants-spin-spin splittings-comprise a very large amount of data that can be used to establish the conformations of RNA molecules. Proton-proton and proton-phosphorus splittings have been used the most, but the availability of {sup 13}C-and {sup 15}N-labeled molecules allow many more coupling constants to be used for determining conformation. We will systematically consider the torsion angles that characterize a nucleotide unit and the coupling constants that depend on the values of these torsion angles. Karplus-type equations have been established relating many three-bond coupling constants to torsion angles. However, one- and two-bond coupling constants can also depend on conformation. Serianni and coworkers measured carbon-proton coupling constants in ribonucleosides and have calculated their values as a function of conformation. The signs of two-bond coupling can be very useful because it is easier to measure a sign than an accurate magnitude.
Association constants of telluronium salts
International Nuclear Information System (INIS)
Kovach, N.A.; Rivkin, B.B.; Sadekov, T.D.; Shvajka, O.P.
1996-01-01
Association constants in acetonitrile of triphenyl telluronium salts, which are dilute electrolytes, are determined through the conductometry method. Satisfactory correlation dependence of constants of interion association and threshold molar electroconductivity on the Litvinenko-Popov constants for depositing groups is identified. 6 refs
Anisotropic constant-roll inflation
Energy Technology Data Exchange (ETDEWEB)
Ito, Asuka; Soda, Jiro [Kobe University, Department of Physics, Kobe (Japan)
2018-01-15
We study constant-roll inflation in the presence of a gauge field coupled to an inflaton. By imposing the constant anisotropy condition, we find new exact anisotropic constant-roll inflationary solutions which include anisotropic power-law inflation as a special case. We also numerically show that the new anisotropic solutions are attractors in the phase space. (orig.)
Quintessence and the cosmological constant
International Nuclear Information System (INIS)
Doran, M.; Wetterich, C.
2003-01-01
Quintessence -- the energy density of a slowly evolving scalar field -- may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea in the light of the cosmological constant problem. Cosmological observations or a time variation of fundamental 'constants' can distinguish quintessence from a cosmological constant
International Nuclear Information System (INIS)
Yoshita, Takashi; Ishihara, Yoshinao; Ishiguro, Katsuhiko; Ohi, Takao; Nakajima, Kunihiko
1999-11-01
Corrosion of the carbon steel overpack leads to a volume expansion since the specific gravity of corrosion products is smaller than carbon steel. The buffer material is compressed due to the corrosive swelling, reducing its thickness and porosity. On the other hand, buffer material may be extruded into fractures of the surrounding rock and this may lead to a deterioration of the planned functions of the buffer, including retardation of nuclides migration and colloid filtration. In this study, the sensitivity analyses for the effect of volume expansion and intrusion of the buffer material on nuclide migration in the engineering barrier system are carried out. The sensitivity analyses were performed on the decrease in the thickness of the buffer material in the radial direction caused by the corrosive swelling, and the change in the porosity and dry density of the buffer caused by both compacting due to corrosive swelling and intrusion of buffer material. As results, it was found the maximum release rates of relatively shorter half-life nuclides from the outside of the buffer material decreased for taking into account of a volume expansion due to overpack corrosion. On the other hand, the maximum release rates increased when the intrusion of buffer material was also taking into account. It was, however, the maximum release rates of longer half-life nuclides, such as Cs-137 and Np-237, were insensitive to the change of buffer material thickness, and porosity and dry density of buffer. (author)
Ballast system for maintaining constant pressure in a glove box
Shlichta, Paul J.
1989-09-01
A ballast system is disclosed for a glove box including a fixed platform on which is mounted an inflatable bag on top of which resides a cover and a weight. The variable gas volume of the inflatable bag communicates with that of the glove box via a valved tube. The weight and the gas volume are selected to maintain a relatively constant pressure in the glove box despite variations in the glove box volume while avoiding the use of complicated valving apparatus.
Stability constants for silicate adsorbed to ferrihydrite
DEFF Research Database (Denmark)
Hansen, Hans Christian Bruun; Wetche, T.P.; Raulund-Rasmussen, Karsten
1994-01-01
Intrinsic surface acidity constants (K(a1)intr, K(a2)intr) and surface complexation constant for adsorption of orthosilicate onto synthetic ferrihydrite (K(Si) for the complex = FeOSi(OH)3) have been determined from acid/base titrations in 0.001-0.1 m NaClO4 electrolytes and silicate adsorption...... experiments in 0.01 m NaNO3 electrolyte (pH 3-6). The surface equilibrium constants were calculated according to the two-layer model by Dzombak & Morel (1990). Near equilibrium between protons/hydroxyls in solution and the ferrihydrite surface was obtained within minutes while equilibration with silicate...
The relative volume growth of minimal submanifolds
DEFF Research Database (Denmark)
Markvorsen, Steen; Palmer, V.
2002-01-01
The volume growth of certain well-defined subsets of minimal submanifolds in riemannian spaces are compared with the volume growth of balls and spheres ill space forms of constant curvature.......The volume growth of certain well-defined subsets of minimal submanifolds in riemannian spaces are compared with the volume growth of balls and spheres ill space forms of constant curvature....
Cosmological constant in the quantum multiverse
International Nuclear Information System (INIS)
Larsen, Grant; Nomura, Yasunori; Roberts, Hannes L. L.
2011-01-01
Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and outcomes of particular experiments, according to a single probability formula. This provides complete unification of the eternally inflating multiverse and many worlds in quantum mechanics. In this paper, we elucidate how cosmological parameters can be calculated in this framework, and study the probability distribution for the value of the cosmological constant. We consider both positive and negative values, and find that the observed value is consistent with the calculated distribution at an order of magnitude level. In particular, in contrast to the case of earlier measure proposals, our framework prefers a positive cosmological constant over a negative one. These results depend only moderately on how we model galaxy formation and life evolution therein.
Measurement of Crystalline Lens Volume During Accommodation in a Lens Stretcher.
Marussich, Lauren; Manns, Fabrice; Nankivil, Derek; Maceo Heilman, Bianca; Yao, Yue; Arrieta-Quintero, Esdras; Ho, Arthur; Augusteyn, Robert; Parel, Jean-Marie
2015-07-01
To determine if the lens volume changes during accommodation. The study used data acquired on 36 cynomolgus monkey lenses that were stretched in a stepwise fashion to simulate disaccommodation. At each step, stretching force and dioptric power were measured and a cross-sectional image of the lens was acquired using an optical coherence tomography system. Images were corrected for refractive distortions and lens volume was calculated assuming rotational symmetry. The average change in lens volume was calculated and the relation between volume change and power change, and between volume change and stretching force, were quantified. Linear regressions of volume-power and volume-force plots were calculated. The mean (± SD) volume in the unstretched (accommodated) state was 97 ± 8 mm3. On average, there was a small but statistically significant (P = 0.002) increase in measured lens volume with stretching. The mean change in lens volume was +0.8 ± 1.3 mm3. The mean volume-power and volume-load slopes were -0.018 ± 0.058 mm3/D and +0.16 ± 0.40 mm3/g. Lens volume remains effectively constant during accommodation, with changes that are less than 1% on average. This result supports a hypothesis that the change in lens shape with accommodation is accompanied by a redistribution of tissue within the capsular bag without significant compression of the lens contents or fluid exchange through the capsule.
Piezooptical constants of Rochelle salt crystals
V.Yo. Stadnyk; M.O. Romanyuk; V.Yu. Kurlyak; V.F.Vachulovych
2000-01-01
The influence of uniaxial mechanical pressure applied along the principal axes and the corresponding bisectors on the birefringent properties of Rochelle salt (RS) crystals are studied. The temperature (77-300 K) and spectral (300-700 nm) dependencies of the effective and absolute piezooptical constants of the RS crystals are calculated. The intercept of dispersion curves of is revealed in the region of the birefringence sign inversion. This testifies that the anizotropy of the piezooptical ...
Elongational flow of polymer melts at constant strain rate, constant stress and constant force
Wagner, Manfred H.; Rolón-Garrido, Víctor H.
2013-04-01
Characterization of polymer melts in elongational flow is typically performed at constant elongational rate or rarely at constant tensile stress conditions. One of the disadvantages of these deformation modes is that they are hampered by the onset of "necking" instabilities according to the Considère criterion. Experiments at constant tensile force have been performed even more rarely, in spite of the fact that this deformation mode is free from necking instabilities and is of considerable industrial relevance as it is the correct analogue of steady fiber spinning. It is the objective of the present contribution to present for the first time a full experimental characterization of a long-chain branched polyethylene melt in elongational flow. Experiments were performed at constant elongation rate, constant tensile stress and constant tensile force by use of a Sentmanat Extensional Rheometer (SER) in combination with an Anton Paar MCR301 rotational rheometer. The accessible experimental window and experimental limitations are discussed. The experimental data are modelled by using the Wagner I model. Predictions of the steady-start elongational viscosity in constant strain rate and creep experiments are found to be identical, albeit only by extrapolation of the experimental data to Hencky strains of the order of 6. For constant stress experiments, a minimum in the strain rate and a corresponding maximum in the elongational viscosity is found at a Hencky strain of the order of 3, which, although larger than the steady-state value, follows roughly the general trend of the steady-state elongational viscosity. The constitutive analysis also reveals that constant tensile force experiments indicate a larger strain hardening potential than seen in constant elongation rate or constant tensile stress experiments. This may be indicative of the effect of necking under constant elongation rate or constant tensile stress conditions according to the Considère criterion.
Fu, Shaotong
2018-01-01
In order to dilute the harmful smoke and dust of the working surface in the production of the roadway in the mine shaft, the combination of mine local ventilation is often considered when conditions permitting. However there is no definite method to determine the distance between fan and working surface. Considering the concentration of smoke, the size of working face, the ventilation time, the wind speed of the working face and the principle of suction volume, this paper analyzes the long - drawn short - pressure type of the ventilation scheme, and presents an optimal algorithm for the distance between the exhaust ventilator and the working face:{{L}}{{o}}=\\frac{{({{{v}}}{{f}}{{t}})}{{Z}}{{{S}}}{{o}}\\frac{\\exists }{{{z}}{{β }}}}{3.398{{{S}}}W\\frac{1}{{{z}}{{A}}}}. Then this paperpresentsa reference distance for different wind speed requirements of a project.
Energy Technology Data Exchange (ETDEWEB)
Primm III, RT
2002-05-29
This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the US during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the computational benchmarks and for those experimental benchmarks that the US and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors.
International Nuclear Information System (INIS)
Primm III, RT
2002-01-01
This volume of the progress report provides documentation of reactor physics and criticality safety studies conducted in the US during fiscal year 1997 and sponsored by the Fissile Materials Disposition Program of the US Department of Energy. Descriptions of computational and experimental benchmarks for the verification and validation of computer programs for neutron physics analyses are included. All benchmarks include either plutonium, uranium, or mixed uranium and plutonium fuels. Calculated physics parameters are reported for all of the computational benchmarks and for those experimental benchmarks that the US and Russia mutually agreed in November 1996 were applicable to mixed-oxide fuel cycles for light-water reactors
Method for calculating solid-solid phase transitions at high temperature: An application to N2O
International Nuclear Information System (INIS)
Kuchta, B.; Etters, R.D.
1992-01-01
Two similar techniques for calculating solid-solid phase transitions at high temperatures are developed, where the contribution of the entropy may be a decisive factor. They utilize an artificial reversible path from one phase to another by application of a control parameter. Thermodynamic averages are calculated using constant-volume and constant-pressure Monte Carlo techniques. An application to N 2 O at room temperature shows that the cubic Pa3 to orthorhombic Cmca transition occurs near 4.9-GPa pressure, very close to the value calculated at very low temperatures. These results support experimental evidence that the transition pressure is virtually independent of temperature
Energy Technology Data Exchange (ETDEWEB)
Nascimento, Pedro Augusto do; Rodrigues, Araken dos S. Werneck, E-mail: pedroan88@gmail.com [Universidade de Brasilia (UnB), DF (Brazil). Programa de Pos Graduacao em Ciencias e Tecnologias em Saude
2016-07-01
This paper presents the application (APP) DosePet that calculates the amount of medicament for PET / CT in patients according to the predetermined radiation dose. The software has been designed using the web MIT App Inventor2 tool for Android platform. The application allows the workers to simulate the amount of radiation still existing in the facilities after the applications, increasing security and reducing exposures, and enable greater efficiency in the use of the radiopharmaceutical. (author)
Energy Technology Data Exchange (ETDEWEB)
Fujimoto, M.; Nishida, K.; Hiroyasu, H. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering; Tabata, M. [Mazda Motor Corp., Hiroshima (Japan)
1996-06-25
Laser-induced fluorescence from nitrogen dioxide (NO2) as gas fuel tracer was applied to determine mixture stratification in a pancake-type constant-volume combustion chamber using propane and hydrogen fuels. The second-harmonic output of a pulsed Nd: YAG laser was used as a light source for fluorescence excitation. The fluorescence images were corrected by a gated image-intensified CCD camera. The quantitative analysis of fuel concentration was made possible by the application of linearity between fluorescence intensity and NO2 concentration at a low trace level. The stratified mixture (center-rich or center-lean) was concentrically formed in the central region of the chamber by a jet flow from a tangentially oriented port. The concentration difference in the radial direction of the chamber decreased with time from the start of injection. The rate of decrease was faster for hydrogen than for propane. After 300 ms from start of injection, however, the time histories of the concentration difference were nearly constant for both fuels regardless of overall concentration. 10 refs., 16 figs., 1 tab.
Spectrophotometric determination of association constant
DEFF Research Database (Denmark)
2016-01-01
Least-squares 'Systematic Trial-and-Error Procedure' (STEP) for spectrophotometric evaluation of association constant (equilibrium constant) K and molar absorption coefficient E for a 1:1 molecular complex, A + B = C, with error analysis according to Conrow et al. (1964). An analysis of the Charge...
Modelling and simulation of multi-phase effects on X-ray elasticity constants
Freour, S; Guillen, R; François, M X
2003-01-01
This paper deals with the calculation of X-ray Elasticity Constants (XEC) of phases embedded in multi-phase polycrystals. A three scales (macroscopic, pseudo-macroscopic, mesoscopic) model based on the classical self-consistent formalism is developed in order to analyse multi-phase effects on XEC values. Simulations are performed for cubic or hexagonal crystallographic structure phases embedded in several two-phases materials. In fact, it is demonstrated that XEC vary with the macroscopic stiffness of the whole polycrystal. In consequence, the constants of one particular phase depend on the elastic behaviour and the volume fraction of all the phases constituting the material. Now, XEC play a leading role in pseudo-macroscopic stresses determination by X-Ray Diffraction (XRD) methods. In this work, a quantitative analysis of the multi-phase effects on stresses determination by XRD methods was performed. Numerical results will be compared and discussed. (Abstract Copyright [2003], Wiley Periodicals, Inc.)
International Nuclear Information System (INIS)
Ahmed, M.Y.Y.; Kloft, W.J.
1985-01-01
The haemolymph volume of Tenebrio molitor L. adults was determined by a radioisotope dilution technique. Two myl (14)C-inulin were injected into the haemolymph with a micro-syringe. After sufficient time for through mixing, the labelled haemolymph was collected individually under separation of sexes. Total haemolymph was calculated by a conventional formula for radioisotope dilution. The mean haemolymph volume of normal newly emerged males was 61.1+-14.2 myl and remained constant between day 2 (61.2 +-2.1) and day 3 (55.6+-9.2) after emergence. In comparison newly emerged females had a volume of 53.5+-2.3 myl which increased to 69.4+-11.7 myl day 2 resp. 64.0+-16.7 myl by day 3. The haemolymph volume of X-irradiated (5000 R) males remains almost constant. However in case of irradiated females the haemolymph volume also remains constant in contrast to unirradiated individuals
Bonham, Russell A.
1998-05-01
A simple experiment, utilizing readily available equipment and chemicals, is described. It allows students to explore the concepts of chemical equilibria, nonideal behavior of aqueous solutions, least squares with adjustment of nonlinear model parameters, and errors. The relationship between the pH of a solution of known initial concentration and volume of a weak acid as it is titrated by known volumes of a monohydroxy strong base is developed rigorously assuming ideal behavior. A distinctive feature of this work is a method that avoids dealing with the problems presented by equations with multiple roots. The volume of base added is calculated in terms of a known value of the pH and the equilibrium constants. The algebraic effort involved is nearly the same as the alternative of deriving a master equation for solving for the hydrogen ion concentration or activity and results in a more efficient computational algorithm. This approach offers two advantages over the use of computer software to solve directly for the hydrogen ion concentration. First, it avoids a potentially lengthy iterative procedure encountered when the polynomial exceeds third order in the hydrogen ion concentration; and second, it provides a means of obtaining results with a hand calculator that can prove useful in checking computer code. The approach is limited to weak solutions to avoid dealing with molalities and to insure that the Debye-Hückel limiting law is applicable. The nonlinear least squares algorithm Nonlinear Fit, found in the computational mathematics library Mathematica, is utilized to fit the measured volume of added base to the calculated value as a function of the measured pH subject to variation of all the equilibrium constants as parameters (including Kw). The experiment emphasizes both data collection and data analysis aspects of the problem. Data for the titration of phosphorous acid, H3PO3, by NaOH are used to illustrate the approach. Fits of the data without corrections
Critical experiments analysis by ABBN-90 constant system
Energy Technology Data Exchange (ETDEWEB)
Tsiboulia, A.; Nikolaev, M.N.; Golubev, V. [Institute of Physics and Power Engineering, Obninsk (Russian Federation)] [and others
1997-06-01
The ABBN-90 is a new version of the well-known Russian group-constant system ABBN. Included constants were calculated based on files of evaluated nuclear data from the BROND-2, ENDF/B-VI, and JENDL-3 libraries. The ABBN-90 is intended for the calculation of different types of nuclear reactors and radiation shielding. Calculations of criticality safety and reactivity accidents are also provided by using this constant set. Validation of the ABBN-90 set was made by using a computerized bank of evaluated critical experiments. This bank includes the results of experiments conducted in Russia and abroad of compact spherical assemblies with different reflectors, fast critical assemblies, and fuel/water-solution criticalities. This report presents the results of the calculational analysis of the whole collection of critical experiments. All calculations were produced with the ABBN-90 group-constant system. Revealed discrepancies between experimental and calculational results and their possible reasons are discussed. The codes and archives INDECS system is also described. This system includes three computerized banks: LEMEX, which consists of evaluated experiments and their calculational results; LSENS, which consists of sensitivity coefficients; and LUND, which consists of group-constant covariance matrices. The INDECS system permits us to estimate the accuracy of neutronics calculations. A discussion of the reliability of such estimations is finally presented. 16 figs.
Noori, Nazanin; Wald, Ron; Sharma Parpia, Arti; Goldstein, Marc B
2018-01-01
Accurate assessment of total body water (TBW) is essential for the evaluation of dialysis adequacy (Kt/V urea ). The Watson formula, which is recommended for the calculation of TBW, was derived in healthy volunteers thereby leading to potentially inaccurate TBW estimates in maintenance hemodialysis recipients. Bioimpedance spectroscopy (BIS) may be a robust alternative for the measurement of TBW in hemodialysis recipients. The primary objective of this study was to evaluate the accuracy of Watson formula-derived TBW estimates as compared with TBW measured with BIS. Second, we aimed to identify the anthropometric characteristics that are most likely to generate inaccuracy when using the Watson formula to calculate TBW. Finally, we derived novel anthropometric equations for the more accurate estimation of TBW. This was a cross-sectional study of prevalent in-center HD patients at St Michael's Hospital. One hundred eighty-four hemodialysis patients (109 men and 75 women) were evaluated in this study. Anthropometric measurements including weight, height, waist circumference, midarm circumference, and 4-site skinfold (biceps, triceps, subscapular, and suprailiac) thickness were measured; fat mass was measured using the formula by Durnin and Womersley. We measured TBW by BIS using the Body Composition Monitor (Fresenius Medical Care, Bad Homburg, Germany). We used the Bland-Altman method to calculate the difference between the TBW derived from the Watson method and the BIS. To derive new equations for TBW estimation, Pearson's correlation coefficients between BIS-TBW (the reference test) and other variables were examined. We used the least squares regression analysis to develop parsimonious equations to predict TBW. TBW values based on the Watson method had a high correlation with BIS-TBW (correlation coefficients = 0.87 and P Watson formula overestimated TBW by 5.1 (4.5-5.8) liters and 3.8 (3.0-4.5) liters, in men and women, respectively. Higher fat mass and waist
International Nuclear Information System (INIS)
2007-01-01
Motivated by new energetic constraints and the interest of biomass, the authors report a bibliographical survey of studies concerning the evaluation of the available forest biomass. They comment the geographical and time distribution of the identified and compiled studies. They analyse their different topics. Then, they discuss the various field hypotheses, discuss and comments various resource assessment methodologies. They comment the resource the French forest can be, present a synthesis of the available resource at the regional level according to the different studies. They propose a review of some technical-economical aspects (costs, energy cost, price evolutions, improvement of the wood-energy mobilization). The second part proposes a whole set of volume calculations for different forest types (clusters or plantations of trees, copses, sawmills products), for industry and household consumption. It discusses the available volumes with respect to accessibility, additional available volumes, and possible improvements. The third part analyses, comments and discusses the wood market and wood energetic uses, and the possible supply curves for wood energetic uses by 2016
Constant Volume Combustion Engine for Planetary Ascent Vehicles, Phase I
National Aeronautics and Space Administration — The Mars Sample Return mission is being planned to return samples of Martian rock, regolith, and atmosphere to Earth for scientific analysis. The Martian sample size...
40 CFR 86.519-90 - Constant volume sampler calibration.
2010-07-01
... total calibration. Allow the system to stabilize for 3 minutes and repeat the data acquisition. (7) Data... decrease as reflected by lower values for M. Calibrations should be performed at pump startup and after...
Inflation with a smooth constant-roll to constant-roll era transition
Odintsov, S. D.; Oikonomou, V. K.
2017-07-01
In this paper, we study canonical scalar field models, with a varying second slow-roll parameter, that allow transitions between constant-roll eras. In the models with two constant-roll eras, it is possible to avoid fine-tunings in the initial conditions of the scalar field. We mainly focus on the stability of the resulting solutions, and we also investigate if these solutions are attractors of the cosmological system. We shall calculate the resulting scalar potential and, by using a numerical approach, we examine the stability and attractor properties of the solutions. As we show, the first constant-roll era is dynamically unstable towards linear perturbations, and the cosmological system is driven by the attractor solution to the final constant-roll era. As we demonstrate, it is possible to have a nearly scale-invariant power spectrum of primordial curvature perturbations in some cases; however, this is strongly model dependent and depends on the rate of the final constant-roll era. Finally, we present, in brief, the essential features of a model that allows oscillations between constant-roll eras.
Elastic constants of diamond from molecular dynamics simulations
International Nuclear Information System (INIS)
Gao Guangtu; Van Workum, Kevin; Schall, J David; Harrison, Judith A
2006-01-01
The elastic constants of diamond between 100 and 1100 K have been calculated for the first time using molecular dynamics and the second-generation, reactive empirical bond-order potential (REBO). This version of the REBO potential was used because it was redesigned to be able to model the elastic properties of diamond and graphite at 0 K while maintaining its original capabilities. The independent elastic constants of diamond, C 11 , C 12 , and C 44 , and the bulk modulus were all calculated as a function of temperature, and the results from the three different methods are in excellent agreement. By extrapolating the elastic constant data to 0 K, it is clear that the values obtained here agree with the previously calculated 0 K elastic constants. Because the second-generation REBO potential was fit to obtain better solid-state force constants for diamond and graphite, the agreement with the 0 K elastic constants is not surprising. In addition, the functional form of the second-generation REBO potential is able to qualitatively model the functional dependence of the elastic constants and bulk modulus of diamond at non-zero temperatures. In contrast, reactive potentials based on other functional forms do not reproduce the correct temperature dependence of the elastic constants. The second-generation REBO potential also correctly predicts that diamond has a negative Cauchy pressure in the temperature range examined
International Nuclear Information System (INIS)
Hauk, V.; Kockelmann, H.
1979-01-01
Methods of calculation are developed for determination of single crystal elastic compliance or stiffness constants of cubic and hexagonal materials from mechanical and X-ray elastic constants of polycrystals. The calculations are applied to pure, cubic iron and hexagonal WC. There are no single crystal constants in the literature for WC, because no single crystals suitable for measurement are available. (orig.) [de
Development of a methodology to generate materials constant for the FLARE-G computer code
International Nuclear Information System (INIS)
Martinez, A.S.; Rosier, C.J.; Schirru, R.; Silva, F.C. da; Thome Filho, Z.D.
1983-01-01
The methodology of calculation aiming to determine the parametrization constants of the multiplication factor and migration area is presented. These physical parameters are necessary in the solution of the diffusion equation with the nodal method, and they represent the adequated form of the macrogroup constants in the cell calculation. An automatic system was done to generate the parametrization constants. (E.G.) [pt
Computing the Gromov hyperbolicity constant of a discrete metric space
Ismail, Anas
2012-07-01
Although it was invented by Mikhail Gromov, in 1987, to describe some family of groups[1], the notion of Gromov hyperbolicity has many applications and interpretations in different fields. It has applications in Biology, Networking, Graph Theory, and many other areas of research. The Gromov hyperbolicity constant of several families of graphs and geometric spaces has been determined. However, so far, the only known algorithm for calculating the Gromov hyperbolicity constant δ of a discrete metric space is the brute force algorithm with running time O (n4) using the four-point condition. In this thesis, we first introduce an approximation algorithm which calculates a O (log n)-approximation of the hyperbolicity constant δ, based on a layering approach, in time O(n2), where n is the number of points in the metric space. We also calculate the fixed base point hyperbolicity constant δr for a fixed point r using a (max, min)−matrix multiplication algorithm by Duan in time O(n2.688)[2]. We use this result to present a 2-approximation algorithm for calculating the hyper-bolicity constant in time O(n2.688). We also provide an exact algorithm to compute the hyperbolicity constant δ in time O(n3.688) for a discrete metric space. We then present some partial results we obtained for designing some approximation algorithms to compute the hyperbolicity constant δ.
Gamma radiation inside closed volumes with thin irradiating walls
International Nuclear Information System (INIS)
Karpov, V.I.
1978-01-01
The dose rate of gamma radiation inside a parallelepiped with thin radiating walls was calculated. The calculation was based on determining the dose rate from a rectangular plate and subsequently summing the dose rates from all the parallelepiped walls. The dose rate from the rectangular plate was calculated by reducing it to an equivalent plate of infinite length and certain fixed width. When the radiators had constant surface density, the dose rate in the geometric centre of volumes having the form of a parallelepiped was shown to have the least value in the case when the parallelepiped degenerates to a cube
Varying Constants, Gravitation and Cosmology
Directory of Open Access Journals (Sweden)
Jean-Philippe Uzan
2011-03-01
Full Text Available Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.
DEFF Research Database (Denmark)
Álvarez-Asencio, R.; Thormann, Esben; Rutland, M.W.
2013-01-01
A technique has been developed for the calculation of torsional spring constants for AFM cantilevers based on the combination of the normal spring constant and plate/beam theory. It is easy to apply and allow the determination of torsional constants for stiff cantilevers where the thermal power s...... spectrum is difficult to obtain due to the high resonance frequency and low signal/noise ratio. The applicability is shown to be general and this simple approach can thus be used to obtain torsional constants for any beam shaped cantilever. © 2013 AIP Publishing LLC....
Directory of Open Access Journals (Sweden)
Pieprzyca J.
2015-04-01
Full Text Available A common method used in identification of hydrodynamics phenomena occurring in Continuous Casting (CC device's tundish is to determine the RTD curves of time. These curves allows to determine the way of the liquid steel flowing and mixing in the tundish. These can be identified either as the result of numerical simulation or by the experiments - as the result of researching the physical models. Special problem is to objectify it while conducting physical research. It is necessary to precisely determine the time constants which characterize researched phenomena basing on the data acquired in the measured change of the concentration of the tracer in model liquid's volume. The mathematical description of determined curves is based on the approximate differential equations formulated in the theory of fluid mechanics. Solving these equations to calculate the time constants requires a special software and it is very time-consuming. To improve the process a method was created to calculate the time constants with use of automation elements. It allows to solve problems using algebraic method, which improves interpretation of the research results of physical modeling.
Stabilized power constant alimentation; Alimentation regulee a puissance constante
Energy Technology Data Exchange (ETDEWEB)
Roussel, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1968-06-01
The study and realization of a stabilized power alimentation variable from 5 to 100 watts are described. In order to realize a constant power drift of Lithium compensated diodes, we have searched a 1 per cent precision of regulation and a response time minus than 1 sec. Recent components like Hall multiplicator and integrated amplifiers give this possibility and it is easy to use permutable circuits. (author) [French] On decrit l'etude et la realisation d'une alimentation a puissance constante reglable dans une gamme de 5 a 100 watts. Prevue pour le drift a puissance constante des diodes compensees au lithium, l'etude a ete menee en vue d'obtenir une precision de regulation de 1 pour cent et un temps de reponse inferieur a la seconde. Des systemes recents tels que multiplicateurs a effet Hall et circuits integres ont permis d'atteindre ce but tout en facilitant l'emploi de modules interchangeables. (auteur)
From the Rydberg constant to the fundamental constants metrology
International Nuclear Information System (INIS)
Nez, F.
2005-06-01
This document reviews the theoretical and experimental achievements of the author since the beginning of his scientific career. This document is dedicated to the spectroscopy of hydrogen, deuterium and helium atoms. The first part is divided into 6 sub-sections: 1) the principles of hydrogen spectroscopy, 2) the measurement of the 2S-nS/nD transitions, 3) other optical frequency measurements, 4) our contribution to the determination of the Rydberg constant, 5) our current experiment on the 1S-3S transition, 6) the spectroscopy of the muonic hydrogen. Our experiments have improved the accuracy of the Rydberg Constant by a factor 25 in 15 years and we have achieved the first absolute optical frequency measurement of a transition in hydrogen. The second part is dedicated to the measurement of the fine structure constant and the last part deals with helium spectroscopy and the search for optical references in the near infrared range. (A.C.)
Learning Read-constant Polynomials of Constant Degree modulo Composites
DEFF Research Database (Denmark)
Chattopadhyay, Arkadev; Gavaldá, Richard; Hansen, Kristoffer Arnsfelt
2011-01-01
Boolean functions that have constant degree polynomial representation over a fixed finite ring form a natural and strict subclass of the complexity class \\textACC0ACC0. They are also precisely the functions computable efficiently by programs over fixed and finite nilpotent groups. This class...... is not known to be learnable in any reasonable learning model. In this paper, we provide a deterministic polynomial time algorithm for learning Boolean functions represented by polynomials of constant degree over arbitrary finite rings from membership queries, with the additional constraint that each variable...
The neutron physics constants bank of the I.V. Kurchatov Institute of Atomic Energy
International Nuclear Information System (INIS)
Yudkevich, M.S.
1987-01-01
This paper describes the structure and contents of a neutron physics constants bank consisting of libraries, service programs and data preparation codes for reactor calculations. Use of the bank makes the constants fully accessible to users. (author)
Background Independent Open String Field Theory and Constant B-Field
Nemeschansky, D.; Yasnov, V.
2000-01-01
We calculate the background independent action for bosonic and supersymmetric open string field theory in a constant B-field. We also determine the tachyon effective action in the presence of constant B-field.
Energy Technology Data Exchange (ETDEWEB)
Nez, F
2005-06-15
This document reviews the theoretical and experimental achievements of the author since the beginning of his scientific career. This document is dedicated to the spectroscopy of hydrogen, deuterium and helium atoms. The first part is divided into 6 sub-sections: 1) the principles of hydrogen spectroscopy, 2) the measurement of the 2S-nS/nD transitions, 3) other optical frequency measurements, 4) our contribution to the determination of the Rydberg constant, 5) our current experiment on the 1S-3S transition, 6) the spectroscopy of the muonic hydrogen. Our experiments have improved the accuracy of the Rydberg Constant by a factor 25 in 15 years and we have achieved the first absolute optical frequency measurement of a transition in hydrogen. The second part is dedicated to the measurement of the fine structure constant and the last part deals with helium spectroscopy and the search for optical references in the near infrared range. (A.C.)
Systematics of constant roll inflation
Anguelova, Lilia; Suranyi, Peter; Wijewardhana, L. C. R.
2018-02-01
We study constant roll inflation systematically. This is a regime, in which the slow roll approximation can be violated. It has long been thought that this approximation is necessary for agreement with observations. However, recently it was understood that there can be inflationary models with a constant, and not necessarily small, rate of roll that are both stable and compatible with the observational constraint ns ≈ 1. We investigate systematically the condition for such a constant-roll regime. In the process, we find a whole new class of inflationary models, in addition to the known solutions. We show that the new models are stable under scalar perturbations. Finally, we find a part of their parameter space, in which they produce a nearly scale-invariant scalar power spectrum, as needed for observational viability.
Development code for group constant processing
International Nuclear Information System (INIS)
Su'ud, Z.
1997-01-01
In this paper methods, formalism and algorithm related to group constant processing problem from basic library such as ENDF/B VI will be described. Basically the problems can be grouped as follows; the treatment of resolved resonance using NR approximation, the treatment of unresolved resonance using statistical method, the treatment of low lying resonance using intermediate resonance approximation, the treatment of thermal energy regions, and the treatment group transfer matrices cross sections. it is necessary to treat interference between resonance properly especially in the unresolved region. in this paper the resonance problems are treated based on Breit-wigner method, and doppler function is treated using Pade approximation for calculation efficiency. finally, some samples of calculational result for some nuclei, mainly for comparison between many methods are discussed in this paper
Tachyon constant-roll inflation
Mohammadi, A.; Saaidi, Kh.; Golanbari, T.
2018-04-01
The constant-roll inflation is studied where the inflaton is taken as a tachyon field. Based on this approach, the second slow-roll parameter is taken as a constant which leads to a differential equation for the Hubble parameter. Finding an exact solution for the Hubble parameter is difficult and leads us to a numerical solution for the Hubble parameter. On the other hand, since in this formalism the slow-roll parameter η is constant and could not be assumed to be necessarily small, the perturbation parameters should be reconsidered again which, in turn, results in new terms appearing in the amplitude of scalar perturbations and the scalar spectral index. Utilizing the numerical solution for the Hubble parameter, we estimate the perturbation parameter at the horizon exit time and compare it with observational data. The results show that, for specific values of the constant parameter η , we could have an almost scale-invariant amplitude of scalar perturbations. Finally, the attractor behavior for the solution of the model is presented, and we determine that the feature could be properly satisfied.
National Oceanic and Atmospheric Administration, Department of Commerce — Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. Declination is calculated using the current World Magnetic Model...
Bijnens, Johan; Rössler, Thomas
2015-11-01
We present a calculation of the finite volume corrections to meson masses and decay constants in three flavour Partially Quenched Chiral Perturbation Theory (PQChPT) through two-loop order in the chiral expansion for the flavour-charged (or off-diagonal) pseudoscalar mesons. The analytical results are obtained for three sea quark flavours with one, two or three different masses. We reproduce the known infinite volume results and the finite volume results in the unquenched case. The calculation has been performed using the supersymmetric formulation of PQChPT as well as with a quark flow technique.
PREFACE: Fundamental Constants in Physics and Metrology
Klose, Volkmar; Kramer, Bernhard
1986-01-01
This volume contains the papers presented at the 70th PTB Seminar which, the second on the subject "Fundamental Constants in Physics and Metrology", was held at the Physikalisch-Technische Bundesanstalt in Braunschweig from October 21 to 22, 1985. About 100 participants from the universities and various research institutes of the Federal Republic of Germany participated in the meeting. Besides a number of review lectures on various broader subjects there was a poster session which contained a variety of topical contributed papers ranging from the theory of the quantum Hall effect to reports on the status of the metrological experiments at the PTB. In addition, the participants were also offered the possibility to visit the PTB laboratories during the course of the seminar. During the preparation of the meeting we noticed that even most of the general subjects which were going to be discussed in the lectures are of great importance in connection with metrological experiments and should be made accessible to the scientific community. This eventually resulted in the idea of the publication of the papers in a regular journal. We are grateful to the editor of Metrologia for providing this opportunity. We have included quite a number of papers from basic physical research. For example, certain aspects of high-energy physics and quantum optics, as well as the many-faceted role of Sommerfeld's fine-structure constant, are covered. We think that questions such as "What are the intrinsic fundamental parameters of nature?" or "What are we doing when we perform an experiment?" can shed new light on the art of metrology, and do, potentially, lead to new ideas. This appears to be especially necessary when we notice the increasing importance of the role of the fundamental constants and macroscopic quantum effects for the definition and the realization of the physical units. In some cases we have reached a point where the limitations of our knowledge of a fundamental constant and
Dielectric Constant Measurements of Solid 4He
Yin, L.; Xia, J. S.; Huan, C.; Sullivan, N. S.; Chan, M. H. W.
2011-03-01
Careful measurements of the dielectric properties of solid 4He have been carried out down to 35 mK, considerably lower than the temperature range of previous studies. The sample was prepared from high purity gas with 3He concentrations of the order of 200 ppb and were formed by the blocked capillary method. The molar volume of the sample was 20.30 cm3. The dielectric constant of the samples was found to be independent of temperature down to 120 mK before showing a continuous increase with decreasing temperature and saturating below 50 mK. The total increase in ɛ is 2 parts in 10-5. The temperature dependence of ɛ mimics the increase in the resonant frequency found in the torsional oscillator studies and also the increase found in the shear modulus measurements.
Stabilized power constant alimentation; Alimentation regulee a puissance constante
Energy Technology Data Exchange (ETDEWEB)
Roussel, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1968-06-01
The study and realization of a stabilized power alimentation variable from 5 to 100 watts are described. In order to realize a constant power drift of Lithium compensated diodes, we have searched a 1 per cent precision of regulation and a response time minus than 1 sec. Recent components like Hall multiplicator and integrated amplifiers give this possibility and it is easy to use permutable circuits. (author) [French] On decrit l'etude et la realisation d'une alimentation a puissance constante reglable dans une gamme de 5 a 100 watts. Prevue pour le drift a puissance constante des diodes compensees au lithium, l'etude a ete menee en vue d'obtenir une precision de regulation de 1 pour cent et un temps de reponse inferieur a la seconde. Des systemes recents tels que multiplicateurs a effet Hall et circuits integres ont permis d'atteindre ce but tout en facilitant l'emploi de modules interchangeables. (auteur)
One-group constant libraries for nuclear equilibrium state
Energy Technology Data Exchange (ETDEWEB)
Mizutani, Akihiko; Sekimoto, Hiroshi [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors
1997-03-01
One-group constant libraries for the nuclear equilibrium state were generated for both liquid sodium cooled MOX fuel type fast reactor and PWR type thermal reactor with Equilibrium Cell Iterative Calculation System (ECICS) using JENDL-3.2, -3, -2 and ENDF/B-VI nuclear data libraries. ECICS produced one-group constant sets for 129 heavy metal nuclides and 1238 fission products. (author)
Experimental determination of third-order elastic constants of diamond.
Lang, J M; Gupta, Y M
2011-03-25
To determine the nonlinear elastic response of diamond, single crystals were shock compressed along the [100], [110], and [111] orientations to 120 GPa peak elastic stresses. Particle velocity histories and elastic wave velocities were measured by using laser interferometry. The measured elastic wave profiles were used, in combination with published acoustic measurements, to determine the complete set of third-order elastic constants. These constants represent the first experimental determination, and several differ significantly from those calculated by using theoretical models.
Evolution of the solar constant
International Nuclear Information System (INIS)
Newman, M.J.
1978-01-01
The ultimate source of the energy utilized by life on Earth is the Sun, and the behavior of the Sun determines to a large extent the conditions under which life originated and continues to thrive. What can be said about the history of the Sun. Has the solar constant, the rate at which energy is received by the Earth from the Sun per unit area per unit time, been constant at its present level since Archean times. Three mechanisms by which it has been suggested that the solar energy output can vary with time are discussed, characterized by long (approx. 10 9 years), intermediate (approx. 10 8 years), and short (approx. years to decades) time scales
On the gravitational constant change
International Nuclear Information System (INIS)
Milyukov, V.K.
1986-01-01
The nowadays viewpoint on the problem of G gravitational constant invariability is presented in brief. The methods and results of checking of the G dependence on the nature of substance (checking of the equivalence principle), G dependepce on distance (checking of Newton gravity law) and time (cosmological experiments) are presented. It is pointed out that all performed experiments don't give any reasons to have doubts in G constancy in space and time and G independence on the nature of the substance
Photodissociation constant of NO2
International Nuclear Information System (INIS)
Nootebos, M.A.; Bange, P.
1992-01-01
The velocity of the dissociation of NO 2 into ozone and NO mainly depends on the ultraviolet sunlight quantity, and with that the cloudiness. A correct value for this reaction constant is important for the accurate modelling of O 3 - and NO 2 -concentrations in plumes of electric power plants, in particular in the case of determination of the amount of photochemical summer smog. An advanced signal processing method (deconvolution, correlation) was applied on the measurements. The measurements were carried out from aeroplanes