International Nuclear Information System (INIS)
Birdsell, K.H.; Campbell, K.; Eggert, K.G.; Travis, B.J.
1989-01-01
This paper presents preliminary transport calculations for radionuclide movement at Yucca Mountain using preliminary data for mineral distributions, retardation parameter distributions, and hypothetical recharge scenarios. These calculations are not performance assessments, but are used to study the effectiveness of the geochemical barriers at the site at mechanistic level. The preliminary calculations presented have many shortcomings and should be viewed only as a demonstration of the modeling methodology. The simulations were run with TRACRN, a finite-difference porous flow and radionuclide transport code developed for the Yucca Mountain Project. Approximately 30,000 finite-difference nodes are used to represent the unsaturated and saturated zones underlying the repository in three dimensions. Sorption ratios for the radionuclides modeled are assumed to be functions of mineralogic assemblages of the underlying rock. These transport calculations present a representative radionuclide cation, 135 Cs and anion, 99 Tc. The effects on transport of many of the processes thought to be active at Yucca Mountain may be examined using this approach. The model provides a method for examining the integration of flow scenarios, transport, and retardation processes as currently understood for the site. It will also form the basis for estimates of the sensitivity of transport calculations to retardation processes. 11 refs., 17 figs., 1 tab
International Nuclear Information System (INIS)
Tanaka, Mitsugu
1978-01-01
LWR plants have a containment spray system to reduce the escape of radioactive material to the environment in a loss-of-coolant accident (LOCA) by washing out fission products, especially radioiodine, and condensing the steam to lower the pressure. For carrying out the containment spray tests, pressure and temperature behaviour of the JAERI Model Containment Vessel in spray cooling has been calculated with computer program CONTEMPT-LT. The following could be studied quantitatively: (1) pressure and temperature raise rates for steam addition rate and (2) pressure fall rate for spray flow rate and spray heat transfer efficiency. (auth.)
Preliminary analysis of four numerical models for calculating the mesoscale transport of Kr-85
Energy Technology Data Exchange (ETDEWEB)
Pepper, D W; Cooper, R E [Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.
1983-01-01
A performance study of four numerical algorithms for multi-dimensional advection-diffusion prediction on mesoscale grids has been made. Dispersion from point and distributed sources and a simulation of a continuous source are compared with analytical solutions to assess relative accuracy. Model predictions are then compared with actual measurements of Kr-85 emitted from the Savannah River Plant (SRP). The particle-in-cell and method of moments algorithms exhibit superior accuracy in modeling single source releases. For modeling distributed sources, algorithms based on the pseudospectral and finite element interpolation concepts exhibit comparable accuracy. The method of moments is felt to be the best overall performer, although all the models appear to be relatively close in accuracy.
DEFF Research Database (Denmark)
Cai, Xiao-Xiao; Llamas-Jansa, Isabel; Mullet, Steven
2013-01-01
Geant4 is an open source general purpose simulation toolkit for particle transportation in matter. Since the extension of the thermal scattering model in Geant4.9.5 and the availability of the IAEA HP model cross section libraries, it is now possible to extend the application area of Geant4......, U and O in uranium dioxide, Al metal, Be metal, and Fe metal. The native HP cross section library G4NDL does not include data for elements with atomic number larger than 92. Therefore, transuranic elements, which have impacts for a realistic reactor, can not be simulated by the combination of the HP...... models and the G4NDL library. However, cross sections of those missing isotopes were made available recently through the IAEA project “new evaluated neutron cross section libraries for Geant4”....
HEU benchmark calculations and LEU preliminary calculations for IRR-1
International Nuclear Information System (INIS)
Caner, M.; Shapira, M.; Bettan, M.; Nagler, A.; Gilat, J.
2004-01-01
We performed neutronics calculations for the Soreq Research Reactor, IRR-1. The calculations were done for the purpose of upgrading and benchmarking our codes and methods. The codes used were mainly WIMS-D/4 for cell calculations and the three dimensional diffusion code CITATION for full core calculations. The experimental flux was obtained by gold wire activation methods and compared with our calculated flux profile. The IRR-1 is loaded with highly enriched uranium fuel assemblies, of the plate type. In the framework of preparation for conversion to low enrichment fuel, additional calculations were done assuming the presence of LEU fresh fuel. In these preliminary calculations we investigated the effect on the criticality and flux distributions of the increase of U-238 loading, and the corresponding uranium density.(author)
International Nuclear Information System (INIS)
Hubbard, W. B.; Militzer, B.
2016-01-01
In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity
Energy Technology Data Exchange (ETDEWEB)
Hubbard, W. B. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Militzer, B. [Department of Earth and Planetary Science, Department of Astronomy, University of California, Berkeley, CA 94720 (United States)
2016-03-20
In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity.
Preliminary isodose calculation for gynecological curietherapy
International Nuclear Information System (INIS)
Bridier, A.; Dutreix, A.; Gerbaulet, A.; Chassagne, D.
1981-01-01
We present a preliminary method of calculating the dimensions of the reference isodose, based upon the geometrical distribution and length of the sources used, their linear activity and the length of treatment, that does not require use of a computer. Inversely, this method can be used to determine the factors necessary to produce a given shape of isodose, and also to predict the change in shape of the isodose that will be produced by altering the various factors. This method was derived from a systematic computer study of dose distribution in which each factor was varied independently of all others. The dimensions of the isodoses, calculated by this method, were found to be in agreement with those derived from computer calculation to within an error of about 2 mm. The method is only applicable for a limited range of positions of the vaginal sources. The influence of the positions of these sources along the line of the axis of uterine catheter and of their inclination to this line, are currently being studied. The results are presented as mathematical formulae relating each dimension of the isodose curves to the features of the application, but could equally well be expressed in tabular form that would be more convenient for everyday use. An example of the calculation used is given to facilitate understanding of the method [fr
Preliminary physics calculations for the Clinch River Breeder Reactor
International Nuclear Information System (INIS)
Kalimullah.
1975-01-01
Calculations of sodium void, fuel, and clad worths, power distribution, and control rod worths have been carried out for an R-Z model of the CRBR, using diffusion theory and first-order perturbation theory for material worths. The power distribution and control rod worths have also been calculated in two-dimensional triangular mesh geometry. The present results are preliminary because of inaccuracy of the reactor model and the cross sections used, but the final results are not expected to be greatly different. (U.S.)
Preliminary topical report on comparison reactor disassembly calculations
International Nuclear Information System (INIS)
McLaughlin, T.P.
1975-11-01
Preliminary results of comparison disassembly calculations for a representative LMFBR model (2100-l voided core) and arbitrary accident conditions are described. The analytical methods employed were the computer programs: FX2-POOL, PAD, and VENUS-II. The calculated fission energy depositions are in good agreement, as are measures of the destructive potential of the excursions, kinetic energy, and work. However, in some cases the resulting fuel temperatures are substantially divergent. Differences in the fission energy deposition appear to be attributable to residual inconsistencies in specifying the comparison cases. In contrast, temperature discrepancies probably stem from basic differences in the energy partition models inherent in the codes. Although explanations of the discrepancies are being pursued, the preliminary results indicate that all three computational methods provide a consistent, global characterization of the contrived disassembly accident
International Nuclear Information System (INIS)
Max Morris
2001-01-01
Recent advances in sensor technology and engineering have made it possible to assemble many related sensors in a common array, often of small physical size. Sensor arrays may report an entire vector of measured values in each data collection cycle, typically one value per sensor per sampling time. The larger quantities of data provided by larger arrays certainly contain more information, however in some cases experience suggests that dramatic increases in array size do not always lead to corresponding improvements in the practical value of the data. The work leading to this report was motivated by the need to develop computational planning tools to approximate the relative effectiveness of arrays of different size (or scale) in a wide variety of contexts. The basis of the work is a statistical model of a generic sensor array. It includes features representing measurement error, both common to all sensors and independent from sensor to sensor, and the stochastic relationships between the quantities to be measured by the sensors. The model can be used to assess the effectiveness of hypothetical arrays in classifying objects or events from two classes. A computer program is presented for evaluating the misclassification rates which can be expected when arrays are calibrated using a given number of training samples, or the number of training samples required to attain a given level of classification accuracy. The program is also available via email from the first author for a limited time
Energy Technology Data Exchange (ETDEWEB)
Manning, Karessa L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dolislager, Fredrick G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bellamy, Michael B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2016-11-01
The Preliminary Remediation Goal (PRG) and Dose Compliance Concentration (DCC) calculators are screening level tools that set forth Environmental Protection Agency's (EPA) recommended approaches, based upon currently available information with respect to risk assessment, for response actions at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites, commonly known as Superfund. The screening levels derived by the PRG and DCC calculators are used to identify isotopes contributing the highest risk and dose as well as establish preliminary remediation goals. Each calculator has a residential gardening scenario and subsistence farmer exposure scenarios that require modeling of the transfer of contaminants from soil and water into various types of biota (crops and animal products). New publications of human intake rates of biota; farm animal intakes of water, soil, and fodder; and soil to plant interactions require updates be implemented into the PRG and DCC exposure scenarios. Recent improvements have been made in the biota modeling for these calculators, including newly derived biota intake rates, more comprehensive soil mass loading factors (MLFs), and more comprehensive soil to tissue transfer factors (TFs) for animals and soil to plant transfer factors (BV's). New biota have been added in both the produce and animal products categories that greatly improve the accuracy and utility of the PRG and DCC calculators and encompass greater geographic diversity on a national and international scale.
International Nuclear Information System (INIS)
Manning, Karessa L.; Dolislager, Fredrick G.; Bellamy, Michael B.
2016-01-01
The Preliminary Remediation Goal (PRG) and Dose Compliance Concentration (DCC) calculators are screening level tools that set forth Environmental Protection Agency's (EPA) recommended approaches, based upon currently available information with respect to risk assessment, for response actions at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites, commonly known as Superfund. The screening levels derived by the PRG and DCC calculators are used to identify isotopes contributing the highest risk and dose as well as establish preliminary remediation goals. Each calculator has a residential gardening scenario and subsistence farmer exposure scenarios that require modeling of the transfer of contaminants from soil and water into various types of biota (crops and animal products). New publications of human intake rates of biota; farm animal intakes of water, soil, and fodder; and soil to plant interactions require updates be implemented into the PRG and DCC exposure scenarios. Recent improvements have been made in the biota modeling for these calculators, including newly derived biota intake rates, more comprehensive soil mass loading factors (MLFs), and more comprehensive soil to tissue transfer factors (TFs) for animals and soil to plant transfer factors (BV's). New biota have been added in both the produce and animal products categories that greatly improve the accuracy and utility of the PRG and DCC calculators and encompass greater geographic diversity on a national and international scale.
Equilibrium fission model calculations
International Nuclear Information System (INIS)
Beckerman, M.; Blann, M.
1976-01-01
In order to aid in understanding the systematics of heavy ion fission and fission-like reactions in terms of the target-projectile system, bombarding energy and angular momentum, fission widths are calculated using an angular momentum dependent extension of the Bohr-Wheeler theory and particle emission widths using angular momentum coupling
Preliminary Calculation on a Spent Fuel Pool Accident using GOTHIC
Energy Technology Data Exchange (ETDEWEB)
Park, Jaehwan; Choi, Yu Jung; Hong, Tae Hyub; Kim, Hyeong-Taek [KHNP-CRI, Daejeon (Korea, Republic of)
2015-10-15
The probability of an accident happening at the spent fuel pool was believed to be quite low until the 2011 Fukushima accident occurred. Notably, large amount of spent fuel are normally stored in the spent fuel pool for a long time compared to the amount of fuel in the reactor core and the total heat released from the spent fuel is high enough to boil the water of the spent fuel pool when the cooling system does not operate. In addition, the enrichment and the burnup of the fuel have both increased in the past decade and heat generation from the spent fuel thereby has also increased. The failure of the cooling system at the spent fuel pool (hereafter, a loss-of-cooling accident) is one of the principal hypothetical causes of an accident that could occur at the spent fuel pool. In this paper, the preliminary calculation of a loss-of-cooling accident was performed. In this paper, the preliminary calculation of a loss-of cooling accident was performed with GOTHIC. The calculation results show boiling away of water in the spent fuel pool due to the loss-of-cooling accident and similar thermal performance of the spent fuel pool with previous research results.
Preliminary ECLSS waste water model
Carter, Donald L.; Holder, Donald W., Jr.; Alexander, Kevin; Shaw, R. G.; Hayase, John K.
1991-01-01
A preliminary waste water model for input to the Space Station Freedom (SSF) Environmental Control and Life Support System (ECLSS) Water Processor (WP) has been generated for design purposes. Data have been compiled from various ECLSS tests and flight sample analyses. A discussion of the characterization of the waste streams comprising the model is presented, along with a discussion of the waste water model and the rationale for the inclusion of contaminants in their respective concentrations. The major objective is to establish a methodology for the development of a waste water model and to present the current state of that model.
Preliminary Analysis For Wolsong Par Effects Using ISACC Calculations
International Nuclear Information System (INIS)
Song, Yong Mann; Kim, Dong Ha
2012-01-01
In the paper, hydrogen control effects using PARs only are analyzed for severe SBO station blackout (SBO) sequences beyond the design basis accidents in WS-1 which are of CANDU6 type reactor. As a computational tool, the latest version of ISAAC4.3 (Integrated Severe Accident Analysis Code for CANDU), which is a fully integrated and lumped severe accident computer code, is used to simulate hydrogen generation and transport inside the reactor building (R/B) before its failure. For the performance of hydrogen removal, the depletion rate equation of K-PAR developed in Korea is applied. In a CANDU reactor, three areas are identified as sources of hydrogen under severe accidents: fuel-coolant interactions in intact channels, suspended fuel or debris interactions in-calandria tank and debris interactions in-calandria vault. The first two origins provide source for the late ('late' terminology is used because it takes more than one day before calandria tank failure) potential hydrogen combustion before calandria tank failure and all the three origins would provide source for the very late potential hydrogen combustion occurring at or after calaria tank failure. If the hydrogen mitigation system fails, the AICC (adiabatic isochoric complete combustion) burning of highly flammable hydrogen may cause Wolsong R/B failure. So hydrogen induced failure possibility is evaluated, using preliminary ISAAC calculations, under several SBO conditions with and without PAR for both late and very late accident periods
Comparison of Calculation Models for Bucket Foundation in Sand
DEFF Research Database (Denmark)
Vaitkunaite, Evelina; Molina, Salvador Devant; Ibsen, Lars Bo
The possibility of fast and rather precise preliminary offshore foundation design is desirable. The ultimate limit state of bucket foundation is investigated using three different geotechnical calculation tools: [Ibsen 2001] an analytical method, LimitState:GEO and Plaxis 3D. The study has focused...... on resultant bearing capacity of variously embedded foundation in sand. The 2D models, [Ibsen 2001] and LimitState:GEO can be used for the preliminary design because they are fast and result in a rather similar bearing capacity calculation compared with the finite element models of Plaxis 3D. The 2D models...
Dissociation - a preliminary contextual model
Directory of Open Access Journals (Sweden)
C Krüger
2007-02-01
Full Text Available Background. The Diagnostic and Statistical Manual of Mental Disorders (DSM system has certain limitations when applied to two South African examples of dissociation, because it is descriptive (non-explanatory and focuses on intrapsychic (non-communal processes. Even the existing Western explanatory models of dissociation fail to accommodate fully the communal aspects of dissociation in our South African context. Objectives and methods. The aim was to explore an expanded perspective on dissociation that does not limit it to an intrapsychic phenomenon, but that accounts for the interrelatedness of individuals within their social context. Auto-ethnography was used. In this article a collective, socially orientated, contextual hermeneutic was applied to two local examples of dissociation. Three existing Western models were expanded along multicontextual, collective lines, for them to be more useful in the pluralistic South African context. Results. This preliminary contextual model of dissociation includes a person’s interpersonal, socio-cultural, and spiritual contexts, in addition to the intrapsychic context. Dissociation is considered to be a normal information-processing tool that maintains balanced, coherent selves-in-society, i.e. individuals connected to each other. In the South African context dissociation appears mostly as a normal phenomenon and seldom as a sign of mental illness. Dissociation is pivotal for the normal construction of individual and communal identities in the face of conflicting sets of information from various contexts. Dissociation may help individuals or communities to survive in a world of conflicting messages, where conflict is often interpersonal/cultural/societal in nature, rather than primarily intrapsychic. Conclusions. This model should be developed and evaluated further. Such evaluation would require suitable new local terminology.
Preliminary core design calculations for the ACPR Upgrade
International Nuclear Information System (INIS)
Pickard, P.S.
1976-01-01
The goal of the Annular Core Pulse Reactor (ACPR) Upgrade design studies is to define a core configuration that provides a significant increase in pulse fluence and fission energy deposition. The reactor modification should provide as flat an energy deposition profile for experiments as feasible. The fuels examined in this study were UO 2 -BeO (5-15 w/o UO 2 ), UC-ZrC-C (200-500 mg U/cc) and U-ZrH 1.5 . The basic core concept examined was a two region core, - a high heat capacity inner core region surrounded by an outer U-ZrH 1.5 region. Survey core calculations utilizing 1D transport calculations and cross sections libraries derived from the ORNL-AMPX code examined relative fuel loadings, fuel temperatures, reactivity requirements and pulse performance improvement. Reference designs for all candidate fuels were defined utilizing 2D transport and Monte Carlo calculations. The performance implications of alternative core designs were also examined for the UO 2 -BeO and UC-ZrC-C fuel candidates. (author)
Preliminary regulatory audit calculation for Shinkori Units 3 and 4 LBLOCA
Energy Technology Data Exchange (ETDEWEB)
Woo, S. W.; Kim, B. S.; Kim, J. K. (and others)
2006-12-15
The objective of this study is to perform a preliminary evaluation for Shinkori Units 3 and 4 LBLOCA by applying KINS Realistic Evaluation Methodology (REM). The following results were obtained: (1) From the evaluation for Shinkori Units 3 and 4 LBLOCA, the peak cladding temperature was evaluated to meet the regulatory requirement and the feasibility of the KINS-REM was identified. (2) The input decks that were developed in the previous studies, were reviewed and the evaluation model of the fluidic device was developed and applied for the audit calculation. (3) The treating method for the uncertainty of the gap conductance was developed and applied for the audit calculation. (4) The pre- and post-processing programs were developed for this study. (5) For the more detailed assessments, the information for the gap conductance, etc. should be improved and the effects of coolant bypass during blowdown, steam binding and so on were not sufficiently evaluated. KINS-REM should be advanced to evaluate these effects properly. The KINS methodology that was used in this study, can be further applied for independent regulatory audit calculations related to the licensing application on LOCA best estimate calculation.
East Area Irradiation Test Facility: Preliminary FLUKA calculations
Lebbos, E; Calviani, M; Gatignon, L; Glaser, M; Moll, M; CERN. Geneva. ATS Department
2011-01-01
In the framework of the Radiation to Electronics (R2E) mitigation project, the testing of electronic equipment in a radiation field similar to the one occurring in the LHC tunnel and shielded areas to study its sensitivity to single even upsets (SEU) is one of the main topics. Adequate irradiation test facilities are therefore required, and one installation is under consideration in the framework of the PS East area renovation activity. FLUKA Monte Carlo calculations were performed in order to estimate the radiation field which could be obtained in a mixed field facility using the slowly extracted 24 GeV/c proton beam from the PS. The prompt ambient dose equivalent as well as the equivalent residual dose rate after operation was also studied and results of simulations are presented in this report.
Recommendations for DSD model calculations
International Nuclear Information System (INIS)
Cvelbar, F.
1999-01-01
The latest achievements of the DSD (direct-semidirect) capture model, such as the extension to unbound final states or to densely distributed bound states, and the introduction of the consistent DSD model are reviewed. Recommendations for the future use of the model are presented. (author)
International Nuclear Information System (INIS)
Koo, Bon Seung; Lee, Kyung Hoon; Song, Jae Seung; Park, Sang Yoon
2013-01-01
In this paper, the basic nuclear characteristics of major emitter materials were surveyed. In addition, preliminary calculations of Cobalt-Vanadium fixed incore detector were performed using the Monte Carlo code. Calculational results were cross-checked by KARMA. KARMA is a two-dimensional multigroup transport theory code developed by the KAERI and approved by Korean regularity agency to be employed as a nuclear design tool for a Korean commercial pressurizer water reactor. The nuclear characteristics of the major emitter materials were surveyed, and preliminary calculations of the hybrid fixed incore detector were performed with the MCNP code. The eigenvalue and pin-by-pin fission power distributions were calculated and showed good agreement with the KARMA calculation results. As future work, gamma power distributions as well as several types of XS of the emitter, insulator, and collector regions for a Co-V ICI assembly will be evaluated and compared
Transition Models for Engineering Calculations
Fraser, C. J.
2007-01-01
While future theoretical and conceptual developments may promote a better understanding of the physical processes involved in the latter stages of boundary layer transition, the designers of rotodynamic machinery and other fluid dynamic devices need effective transition models now. This presentation will therefore center around the development of of some transition models which have been developed as design aids to improve the prediction codes used in the performance evaluation of gas turbine blading. All models are based on Narasimba's concentrated breakdown and spot growth.
MR imaging of prostate. Preliminary experience with calculated imaging in 28 cases
International Nuclear Information System (INIS)
Gevenois, P.A.; Van Regemorter, G.; Ghysels, M.; Delepaut, A.; Van Gansbeke, D.; Struyven, J.
1988-01-01
The majority of studies with MR imaging in prostate disease are based on a semiology obtained using images weighted in T1 and T2. A study was carried out to evaluate effects of images calculated in T1 and T2 obtained at 0.5T. This preliminary study concerns 28 prostate examinations with spin-echo acquisition and inversion-recuperation parameters, and provided images calculated in T1, weighted and calculated in T2. Images allowed detection and characterization of prostate lesions. However, although calculated images accentuate discrimination of the method, the weighted images conserve their place because of their improved spatial resolution [fr
Preliminary Cost Model for Space Telescopes
Stahl, H. Philip; Prince, F. Andrew; Smart, Christian; Stephens, Kyle; Henrichs, Todd
2009-01-01
Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. However, great care is required. Some space telescope cost models, such as those based only on mass, lack sufficient detail to support such analysis and may lead to inaccurate conclusions. Similarly, using ground based telescope models which include the dome cost will also lead to inaccurate conclusions. This paper reviews current and historical models. Then, based on data from 22 different NASA space telescopes, this paper tests those models and presents preliminary analysis of single and multi-variable space telescope cost models.
Temperature Calculations in the Coastal Modeling System
2017-04-01
ERDC/CHL CHETN-IV-110 April 2017 Approved for public release; distribution is unlimited . Temperature Calculations in the Coastal Modeling...tide) and river discharge at model boundaries, wave radiation stress, and wind forcing over a model computational domain. Physical processes calculated...calculated in the CMS using the following meteorological parameters: solar radiation, cloud cover, air temperature, wind speed, and surface water temperature
Preliminary model for core/concrete interactions
International Nuclear Information System (INIS)
Murfin, W.B.
1977-08-01
A preliminary model is described for computing the rate of penetration of concrete by a molten LWR core. Among the phenomena included are convective stirring of the melt by evolved gases, admixture of concrete decomposition products to the melt, chemical reactions, radiative heat loss, and variation of heat transfer coefficients with local pressure. The model is most applicable to a two-phase melt (metallic plus oxidic) having a fairly high metallic content
Calculation models for a nuclear reactor
International Nuclear Information System (INIS)
Tashanii, Ahmed Ali
2010-01-01
Determination of different parameters of nuclear reactors requires neutron transport calculations. Due to complicity of geometry and material composition of the reactor core, neutron calculations were performed for simplified models of the real arrangement. In frame of the present work two models were used for calculations. First, an elementary cell model was used to prepare cross section data set for a homogenized-core reactor model. The homogenized-core reactor model was then used to perform neutron transport calculation. The nuclear reactor is a tank-shaped thermal reactor. The semi-cylindrical core arrangement consists of aluminum made fuel bundles immersed in water which acts as a moderator as well as a coolant. Each fuel bundle consists of aluminum cladded fuel rods arranged in square lattices. (author)
Precipitates/Salts Model Sensitivity Calculation
International Nuclear Information System (INIS)
Mariner, P.
2001-01-01
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation on potential seepage waters within a potential repository drift. This work is developed and documented using procedure AP-3.12Q, ''Calculations'', in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The specific objective of this calculation is to examine the sensitivity and uncertainties of the Precipitates/Salts model. The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b). The calculation in the current document examines the effects of starting water composition, mineral suppressions, and the fugacity of carbon dioxide (CO 2 ) on the chemical evolution of water in the drift
Model cross section calculations using LAHET
International Nuclear Information System (INIS)
Prael, R.E.
1992-01-01
The current status of LAHET is discussed. The effect of a multistage preequilibrium exciton model following the INC is examined for neutron emission benchmark calculations, as is the use of a Fermi breakup model for light nuclei rather than an evaporation model. Comparisons are made also for recent fission cross section experiments, and a discussion of helium production cross sections is presented
Verification of EPA's " Preliminary remediation goals for radionuclides" (PRG) electronic calculator
Energy Technology Data Exchange (ETDEWEB)
Stagich, B. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2017-03-29
The U.S. Environmental Protection Agency (EPA) requested an external, independent verification study of their “Preliminary Remediation Goals for Radionuclides” (PRG) electronic calculator. The calculator provides information on establishing PRGs for radionuclides at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites with radioactive contamination (Verification Study Charge, Background). These risk-based PRGs set concentration limits using carcinogenic toxicity values under specific exposure conditions (PRG User’s Guide, Section 1). The purpose of this verification study is to ascertain that the computer codes has no inherit numerical problems with obtaining solutions as well as to ensure that the equations are programmed correctly.
Evaluation of calculational and material models for concrete containment structures
International Nuclear Information System (INIS)
Dunham, R.S.; Rashid, Y.R.; Yuan, K.A.
1984-01-01
A computer code utilizing an appropriate finite element, material and constitutive model has been under development as a part of a comprehensive effort by the Electric Power Research Institute (EPRI) to develop and validate a realistic methodology for the ultimate load analysis of concrete containment structures. A preliminary evaluation of the reinforced and prestressed concrete modeling capabilities recently implemented in the ABAQUS-EPGEN code has been completed. This effort focuses on using a state-of-the-art calculational model to predict the behavior of large-scale reinforced concrete slabs tested under uniaxial and biaxial tension to simulate the wall of a typical concrete containment structure under internal pressure. This paper gives comparisons between calculations and experimental measurements for a uniaxially-loaded specimen. The calculated strains compare well with the measured strains in the reinforcing steel; however, the calculations gave diffused cracking patterns that do not agree with the discrete cracking observed in the experiments. Recommendations for improvement of the calculational models are given. (orig.)
Hybrid reduced order modeling for assembly calculations
International Nuclear Information System (INIS)
Bang, Youngsuk; Abdel-Khalik, Hany S.; Jessee, Matthew A.; Mertyurek, Ugur
2015-01-01
Highlights: • Reducing computational cost in engineering calculations. • Reduced order modeling algorithm for multi-physics problem like assembly calculation. • Non-intrusive algorithm with random sampling. • Pattern recognition in the components with high sensitive and large variation. - Abstract: While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system.
Hybrid reduced order modeling for assembly calculations
Energy Technology Data Exchange (ETDEWEB)
Bang, Youngsuk, E-mail: ysbang00@fnctech.com [FNC Technology, Co. Ltd., Yongin-si (Korea, Republic of); Abdel-Khalik, Hany S., E-mail: abdelkhalik@purdue.edu [Purdue University, West Lafayette, IN (United States); Jessee, Matthew A., E-mail: jesseema@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mertyurek, Ugur, E-mail: mertyurek@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN (United States)
2015-12-15
Highlights: • Reducing computational cost in engineering calculations. • Reduced order modeling algorithm for multi-physics problem like assembly calculation. • Non-intrusive algorithm with random sampling. • Pattern recognition in the components with high sensitive and large variation. - Abstract: While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system.
A Novel Hybrid Similarity Calculation Model
Directory of Open Access Journals (Sweden)
Xiaoping Fan
2017-01-01
Full Text Available This paper addresses the problems of similarity calculation in the traditional recommendation algorithms of nearest neighbor collaborative filtering, especially the failure in describing dynamic user preference. Proceeding from the perspective of solving the problem of user interest drift, a new hybrid similarity calculation model is proposed in this paper. This model consists of two parts, on the one hand the model uses the function fitting to describe users’ rating behaviors and their rating preferences, and on the other hand it employs the Random Forest algorithm to take user attribute features into account. Furthermore, the paper combines the two parts to build a new hybrid similarity calculation model for user recommendation. Experimental results show that, for data sets of different size, the model’s prediction precision is higher than the traditional recommendation algorithms.
A revised calculational model for fission
Energy Technology Data Exchange (ETDEWEB)
Atchison, F
1998-09-01
A semi-empirical parametrization has been developed to calculate the fission contribution to evaporative de-excitation of nuclei with a very wide range of charge, mass and excitation-energy and also the nuclear states of the scission products. The calculational model reproduces measured values (cross-sections, mass distributions, etc.) for a wide range of fissioning systems: Nuclei from Ta to Cf, interactions involving nucleons up to medium energy and light ions. (author)
Recent improvements in the calculation of prompt fission neutron spectra: Preliminary results
International Nuclear Information System (INIS)
Madland, D.G.; LaBauve, R.J.; Nix, J.R.
1989-01-01
We consider three topics in the refinement and improvement of our original calculations of prompt fission neutron spectra. These are an improved calculation of the prompt fission neutron spectrum N(E) from the spontaneous fission of 252 Cf, a complete calculation of the prompt fission neutron spectrum matrix N(E,E n ) from the neutron-induced fission of 235 U, at incident neutron energies ranging from 0 to 15 MeV, and an assessment of the scission neutron component of the prompt fission neutron spectrum. Preliminary results will be presented and compared with experimental measurements and an evaluation. A suggestion is made for new integral cross section measurements. (author). 45 refs, 12 figs, 1 tab
Plasma brake model for preliminary mission analysis
Orsini, Leonardo; Niccolai, Lorenzo; Mengali, Giovanni; Quarta, Alessandro A.
2018-03-01
Plasma brake is an innovative propellantless propulsion system concept that exploits the Coulomb collisions between a charged tether and the ions in the surrounding environment (typically, the ionosphere) to generate an electrostatic force orthogonal to the tether direction. Previous studies on the plasma brake effect have emphasized the existence of a number of different parameters necessary to obtain an accurate description of the propulsive acceleration from a physical viewpoint. The aim of this work is to discuss an analytical model capable of estimating, with the accuracy required by a preliminary mission analysis, the performance of a spacecraft equipped with a plasma brake in a (near-circular) low Earth orbit. The simplified mathematical model is first validated through numerical simulations, and is then used to evaluate the plasma brake performance in some typical mission scenarios, in order to quantify the influence of the system parameters on the mission performance index.
Precipitates/Salts Model Sensitivity Calculation
Energy Technology Data Exchange (ETDEWEB)
P. Mariner
2001-12-20
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation on potential seepage waters within a potential repository drift. This work is developed and documented using procedure AP-3.12Q, ''Calculations'', in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The specific objective of this calculation is to examine the sensitivity and uncertainties of the Precipitates/Salts model. The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b). The calculation in the current document examines the effects of starting water composition, mineral suppressions, and the fugacity of carbon dioxide (CO{sub 2}) on the chemical evolution of water in the drift.
Directory of Open Access Journals (Sweden)
István Bors
2015-09-01
Full Text Available Maize (Zea mays L. is often contaminated with Fusarium verticillioides. This harmful fungus produces fumonisins as secondary metabolites. These fumonisins can appear both free and hidden form in planta. The hidden form is usually bound covalently to cereal starch. From the hidden fumonisins, during enzymatic degradation, glycosides are formed, and the fumonisin is further decomposed during a de-esterification step. In this short communication some preliminary DFT calculated structural results which could be useful in the future to help to understand the van der Waals force controlled molecular interactions between these kinds of mycotoxin molecules and enzymes are demonstrated.
Preliminary Calculations of Shutdown Dose Rate for the CTS Diagnostics System
DEFF Research Database (Denmark)
Klinkby, Esben Bryndt; Nonbøl, Erik; Lauritzen, Bent
2015-01-01
DTU and IST 2 are partners in the design of a collective Thomson Scattering (CTS) diagnostics for ITER through a contract with F4E. The CTS diagnostic utilizes probing radiation of ~60 GHz emitted into the plasma and, using a mirror, collects the scattered radiation by an array of receivers. Having...... on supplying input which affect the system design. Examples include: - Heatloads on plasma facing mirrors and preliminary stress and thermal analysis - Port plug cooling requirements and it's dependence on system design (in particular blanket cut-out) - Shutdown dose-rate calculations (relative analysis...
International Nuclear Information System (INIS)
Lim, Doo Hyun; Hatanaka, Koichiro; Ishii, Eiichi
2010-01-01
JAEA-Horonobe Underground Research Laboratory (URL) is designed for research and development on high-level radioactive waste (HLW) repository in sedimentary rock. For a potential HLW repository, understanding and implementing fracturing and faulting system, with data from the site characterization, into the performance assessment is essential because fracture and fault will be the major conductors or barriers for the groundwater flow and radionuclide release. The objectives are i) quantitative derivation of characteristics and correlation of fracturing/faulting system with geologic and geophysics data obtained from the site characterization, and ii) preliminary performance assessment calculation with characterized site information
Energy Technology Data Exchange (ETDEWEB)
Lim, Doo Hyun [NE Union Hill Road, Suite 200, WA 98052 (United States); Hatanaka, Koichiro; Ishii, Eiichi [Japan Atomic Energy Agency, Hokkaido (Japan)
2010-10-15
JAEA-Horonobe Underground Research Laboratory (URL) is designed for research and development on high-level radioactive waste (HLW) repository in sedimentary rock. For a potential HLW repository, understanding and implementing fracturing and faulting system, with data from the site characterization, into the performance assessment is essential because fracture and fault will be the major conductors or barriers for the groundwater flow and radionuclide release. The objectives are i) quantitative derivation of characteristics and correlation of fracturing/faulting system with geologic and geophysics data obtained from the site characterization, and ii) preliminary performance assessment calculation with characterized site information
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.
Development and preliminary analyses of material balance evaluation model in nuclear fuel cycle
International Nuclear Information System (INIS)
Matsumura, Tetsuo
1994-01-01
Material balance evaluation model in nuclear fuel cycle has been developed using ORIGEN-2 code as basic engine. This model has feature of: It can treat more than 1000 nuclides including minor actinides and fission products. It has flexibility of modeling and graph output using a engineering work station. I made preliminary calculation of LWR fuel high burnup effect (reloading fuel average burnup of 60 GWd/t) on nuclear fuel cycle. The preliminary calculation shows LWR fuel high burnup has much effect on Japanese Pu balance problem. (author)
Preliminary Test for Constitutive Models of CAP
Energy Technology Data Exchange (ETDEWEB)
Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Lee, Keo Hyung; Kim, Min Ki; Lee, Byung Chul [FNC Tech., Seoul (Korea, Republic of); Ha, Sang Jun; Choi, Hoon [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)
2010-05-15
The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (vapor, continuous liquid and dispersed drop) for the assessment of containment specific phenomena, and is featured by assessment capabilities in multi-dimensional and lumped parameter thermal hydraulic cell. Thermal hydraulics solver was developed and has a significant progress now. Implementation of the well proven constitutive models and correlations are essential in other for a containment code to be used with the generalized or optimized purposes. Generally, constitutive equations are composed of interfacial and wall transport models and correlations. These equations are included in the source terms of the governing field equations. In order to develop the best model and correlation package of the CAP code, various models currently used in major containment analysis codes, such as GOTHIC, CONTAIN2.0 and CONTEMPT-LT are reviewed. Several models and correlations were incorporated for the preliminary test of CAP's performance and test results and future plans to improve the level of execution besides will be discussed in this paper
Preliminary Test for Constitutive Models of CAP
International Nuclear Information System (INIS)
Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Lee, Keo Hyung; Kim, Min Ki; Lee, Byung Chul; Ha, Sang Jun; Choi, Hoon
2010-01-01
The development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. The CAP code treats three fields (vapor, continuous liquid and dispersed drop) for the assessment of containment specific phenomena, and is featured by assessment capabilities in multi-dimensional and lumped parameter thermal hydraulic cell. Thermal hydraulics solver was developed and has a significant progress now. Implementation of the well proven constitutive models and correlations are essential in other for a containment code to be used with the generalized or optimized purposes. Generally, constitutive equations are composed of interfacial and wall transport models and correlations. These equations are included in the source terms of the governing field equations. In order to develop the best model and correlation package of the CAP code, various models currently used in major containment analysis codes, such as GOTHIC, CONTAIN2.0 and CONTEMPT-LT are reviewed. Several models and correlations were incorporated for the preliminary test of CAP's performance and test results and future plans to improve the level of execution besides will be discussed in this paper
Hybrid reduced order modeling for assembly calculations
Energy Technology Data Exchange (ETDEWEB)
Bang, Y.; Abdel-Khalik, H. S. [North Carolina State University, Raleigh, NC (United States); Jessee, M. A.; Mertyurek, U. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)
2013-07-01
While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system. (authors)
Model and calculations for net infiltration
International Nuclear Information System (INIS)
Childs, S.W.; Long, A.
1992-01-01
In this paper a conceptual model for calculating net infiltration is developed and implemented. It incorporates the following important factors: viability of climate for the next 10,000 years, areal viability of net infiltration, and important soil/plant factors that affect the soil water budget of desert soils. Model results are expressed in terms of occurrence probabilities for time periods. In addition the variability of net infiltration is demonstrated both for change with time and differences among three soil/hydrologic units present at the site modeled
A calculation of the ZH → γ H decay in the Littlest Higgs Model
International Nuclear Information System (INIS)
Aranda, J I; Ramirez-Zavaleta, F; Tututi, E S; Cortés-Maldonado, I
2016-01-01
New heavy neutral gauge bosons are predicted in many extensions of the Standard Model, those new bosons are associated with additional gauge symmetries. We present a preliminary calculation of the branching ratio decay for heavy neutral gauge bosons ( Z h ) into γ H in the most popular version of the Little Higgs models. The calculation involves the main contributions at one-loop level induced by fermions, scalars and gauge bosons. Preliminary results show a very suppressed branching ratio of the order of 10 -6 . (paper)
Reactor Thermal Hydraulic Numerical Calculation And Modeling
International Nuclear Information System (INIS)
Duong Ngoc Hai; Dang The Ba
2008-01-01
In the paper the results of analysis of thermal hydraulic state models using the numerical codes such as COOLOD, EUREKA and RELAP5 for simulation of the reactor thermal hydraulic states are presented. The calculations, analyses of reactor thermal hydraulic state and safety were implemented using different codes. The received numerical results, which were compared each to other, to experiment measurement of Dalat (Vietnam) research reactor and published results, show their appropriateness and capacity for analyses of different appropriate cases. (author)
International Nuclear Information System (INIS)
1998-01-01
The rationale for restructuring Ontario's electricity industry was restated. Financial elements of the Government's White Paper on the electrical industry included the following: (1) establishing a level playing field on taxes and regulation, (2) restructuring Ontario Hydro into new companies with clear business mandates, and (3) taking action to put the new companies on solid financial ground. To achieve these objectives requires valuation of the new companies as a key part in the restructuring process. This Ministry of Finance document contains preliminary estimates of the total debt and liabilities of Ontario Hydro ($ 39.1 billion), the value of the new generation and service companies ($ 15.8 billion), and the stranded debt ($ 23.3 billion, less the value of dedicated revenue streams of $ 15.4 billion, equal to the residual stranded debt of $ 7.9 billion). The method by which the stranded debt was calculated is also described. It is stressed that the overriding principles governing the financial restructuring plan are to achieve restructuring without increasing electricity rates, to retain maximum value in the electricity sector until stranded debt is retired, and to recover stranded debt from the electricity sector and not from taxpayers. Ministry advisors indicate that these preliminary valuations would allow the new companies to operate as commercial companies in a competitive market and receive investment grade credit ratings. 44 figs
Preliminary Phase Field Computational Model Development
Energy Technology Data Exchange (ETDEWEB)
Li, Yulan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hu, Shenyang Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Ke [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suter, Jonathan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McCloy, John S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Bradley R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ramuhalli, Pradeep [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2014-12-15
experiments, special experimental methods were devised to create similar boundary conditions in the iron films. Preliminary MFM studies conducted on single and polycrystalline iron films with small sub-areas created with focused ion beam have correlated quite well qualitatively with phase-field simulations. However, phase-field model dimensions are still small relative to experiments thus far. We are in the process of increasing the size of the models and decreasing specimen size so both have identical dimensions. Ongoing research is focused on validation of the phase-field model. Validation is being accomplished through comparison with experimentally obtained MFM images (in progress), and planned measurements of major hysteresis loops and first order reversal curves. Extrapolation of simulation sizes to represent a more stochastic bulk-like system will require sampling of various simulations (i.e., with single non-magnetic defect, single magnetic defect, single grain boundary, single dislocation, etc.) with distributions of input parameters. These outputs can then be compared to laboratory magnetic measurements and ultimately to simulate magnetic Barkhausen noise signals.
Matrix model calculations beyond the spherical limit
International Nuclear Information System (INIS)
Ambjoern, J.; Chekhov, L.; Kristjansen, C.F.; Makeenko, Yu.
1993-01-01
We propose an improved iterative scheme for calculating higher genus contributions to the multi-loop (or multi-point) correlators and the partition function of the hermitian one matrix model. We present explicit results up to genus two. We develop a version which gives directly the result in the double scaling limit and present explicit results up to genus four. Using the latter version we prove that the hermitian and the complex matrix model are equivalent in the double scaling limit and that in this limit they are both equivalent to the Kontsevich model. We discuss how our results away from the double scaling limit are related to the structure of moduli space. (orig.)
Development of Dynamic Environmental Effect Calculation Model
International Nuclear Information System (INIS)
Jeong, Chang Joon; Ko, Won Il
2010-01-01
The short-term, long-term decay heat, and radioactivity are considered as main environmental parameters of SF and HLA. In this study, the dynamic calculation models for radioactivity, short-term decay heat, and long-term heat load of the SF are developed and incorporated into the Doneness code. The spent fuel accumulation has become a major issue for sustainable operation of nuclear power plants. If a once-through fuel cycle is selected, the SF will be disposed into the repository. Otherwise, in case of fast reactor or reuse cycle, the SF will be reprocessed and the high level waste will be disposed
Cost Calculation Model for Logistics Service Providers
Directory of Open Access Journals (Sweden)
Zoltán Bokor
2012-11-01
Full Text Available The exact calculation of logistics costs has become a real challenge in logistics and supply chain management. It is essential to gain reliable and accurate costing information to attain efficient resource allocation within the logistics service provider companies. Traditional costing approaches, however, may not be sufficient to reach this aim in case of complex and heterogeneous logistics service structures. So this paper intends to explore the ways of improving the cost calculation regimes of logistics service providers and show how to adopt the multi-level full cost allocation technique in logistics practice. After determining the methodological framework, a sample cost calculation scheme is developed and tested by using estimated input data. Based on the theoretical findings and the experiences of the pilot project it can be concluded that the improved costing model contributes to making logistics costing more accurate and transparent. Moreover, the relations between costs and performances also become more visible, which enhances the effectiveness of logistics planning and controlling significantly
Preliminary deformation model for National Seismic Hazard map of Indonesia
Energy Technology Data Exchange (ETDEWEB)
Meilano, Irwan; Gunawan, Endra; Sarsito, Dina; Prijatna, Kosasih; Abidin, Hasanuddin Z. [Geodesy Research Division, Faculty of Earth Science and Technology, Institute of Technology Bandung (Indonesia); Susilo,; Efendi, Joni [Agency for Geospatial Information (BIG) (Indonesia)
2015-04-24
Preliminary deformation model for the Indonesia’s National Seismic Hazard (NSH) map is constructed as the block rotation and strain accumulation function at the elastic half-space. Deformation due to rigid body motion is estimated by rotating six tectonic blocks in Indonesia. The interseismic deformation due to subduction is estimated by assuming coupling on subduction interface while deformation at active fault is calculated by assuming each of the fault‘s segment slips beneath a locking depth or in combination with creeping in a shallower part. This research shows that rigid body motion dominates the deformation pattern with magnitude more than 15 mm/year, except in the narrow area near subduction zones and active faults where significant deformation reach to 25 mm/year.
Preliminary Calculations of Bypass Flow Distribution in a Multi-Block Air Test
International Nuclear Information System (INIS)
Kim, Min Hwan; Tak, Nam Il
2011-01-01
The development of a methodology for the bypass flow assessment in a prismatic VHTR (Very High Temperature Reactor) core has been conducted at KAERI. A preliminary estimation of variation of local bypass flow gap size between graphite blocks in the NHDD core were carried out. With the predicted gap sizes, their influence on the bypass flow distribution and the core hot spot was assessed. Due to the complexity of gap distributions, a system thermo-fluid analysis code is suggested as a tool for the core thermo-fluid analysis, the model and correlations of which should be validated. In order to generate data for validating the bypass flow analysis model, an experimental facility for a multi-block air test was constructed at Seoul National University (SNU). This study is focused on the preliminary evaluation of flow distribution in the test section to understand how the flow is distributed and to help the selection of experimental case. A commercial CFD code, ANSYS CFX is used for the analyses
Effective hamiltonian calculations using incomplete model spaces
International Nuclear Information System (INIS)
Koch, S.; Mukherjee, D.
1987-01-01
It appears that the danger of encountering ''intruder states'' is substantially reduced if an effective hamiltonian formalism is developed for incomplete model spaces (IMS). In a Fock-space approach, the proof a ''connected diagram theorem'' is fairly straightforward with exponential-type of ansatze for the wave-operator W, provided the normalization chosen for W is separable. Operationally, one just needs a suitable categorization of the Fock-space operators into ''diagonal'' and ''non-diagonal'' parts that is generalization of the corresponding procedure for the complete model space. The formalism is applied to prototypical 2-electron systems. The calculations have been performed on the Cyber 205 super-computer. The authors paid special attention to an efficient vectorization for the construction and solution of the resulting coupled non-linear equations
Model for fission-product calculations
International Nuclear Information System (INIS)
Smith, A.B.
1984-01-01
Many fission-product cross sections remain unmeasurable thus considerable reliance must be placed upon calculational interpolation and extrapolation from the few available measured cross sections. The vehicle, particularly for the lighter fission products, is the conventional optical-statistical model. The applied goals generally are: capture cross sections to 7 to 10% accuracies and inelastic-scattering cross sections to 25 to 50%. Comparisons of recent evaluations and experimental results indicate that these goals too often are far from being met, particularly in the area of inelastic scattering, and some of the evaluated fission-product cross sections are simply physically unreasonable. It is difficult to avoid the conclusion that the models employed in many of the evaluations are inappropriate and/or inappropriately used. In order to alleviate the above unfortunate situations, a regional optical-statistical (OM) model was sought with the goal of quantitative prediction of the cross sections of the lighter-mass (Z = 30-51) fission products. The first step toward that goal was the establishment of a reliable experimental data base consisting of energy-averaged neutron total and differential-scattering cross sections. The second step was the deduction of a regional model from the experimental data. It was assumed that a spherical OM is appropriate: a reasonable and practical assumption. The resulting OM then was verified against the measured data base. Finally, the physical character of the regional model is examined
Davidson, S.; Cui, J.; Followill, D.; Ibbott, G.; Deasy, J.
2008-02-01
The Dose Planning Method (DPM) is one of several 'fast' Monte Carlo (MC) computer codes designed to produce an accurate dose calculation for advanced clinical applications. We have developed a flexible machine modeling process and validation tests for open-field and IMRT calculations. To complement the DPM code, a practical and versatile source model has been developed, whose parameters are derived from a standard set of planning system commissioning measurements. The primary photon spectrum and the spectrum resulting from the flattening filter are modeled by a Fatigue function, cut-off by a multiplying Fermi function, which effectively regularizes the difficult energy spectrum determination process. Commonly-used functions are applied to represent the off-axis softening, increasing primary fluence with increasing angle ('the horn effect'), and electron contamination. The patient dependent aspect of the MC dose calculation utilizes the multi-leaf collimator (MLC) leaf sequence file exported from the treatment planning system DICOM output, coupled with the source model, to derive the particle transport. This model has been commissioned for Varian 2100C 6 MV and 18 MV photon beams using percent depth dose, dose profiles, and output factors. A 3-D conformal plan and an IMRT plan delivered to an anthropomorphic thorax phantom were used to benchmark the model. The calculated results were compared to Pinnacle v7.6c results and measurements made using radiochromic film and thermoluminescent detectors (TLD).
Improved SVR Model for Multi-Layer Buildup Factor Calculation
International Nuclear Information System (INIS)
Trontl, K.; Pevec, D.; Smuc, T.
2006-01-01
The accuracy of point kernel method applied in gamma ray dose rate calculations in shielding design and radiation safety analysis is limited by the accuracy of buildup factors used in calculations. Although buildup factors for single-layer shields are well defined and understood, buildup factors for stratified shields represent a complex physical problem that is hard to express in mathematical terms. The traditional approach for expressing buildup factors of multi-layer shields is through semi-empirical formulas obtained by fitting the results of transport theory or Monte Carlo calculations. Such an approach requires an ad-hoc definition of the fitting function and often results with numerous and usually inadequately explained and defined correction factors added to the final empirical formula. Even more, finally obtained formulas are generally limited to a small number of predefined combinations of materials within relatively small range of gamma ray energies and shield thicknesses. Recently, a new approach has been suggested by the authors involving one of machine learning techniques called Support Vector Machines, i.e., Support Vector Regression (SVR). Preliminary investigations performed for double-layer shields revealed great potential of the method, but also pointed out some drawbacks of the developed model, mostly related to the selection of one of the parameters describing the problem (material atomic number), and the method in which the model was designed to evolve during the learning process. It is the aim of this paper to introduce a new parameter (single material buildup factor) that is to replace the existing material atomic number as an input parameter. The comparison of two models generated by different input parameters has been performed. The second goal is to improve the evolution process of learning, i.e., the experimental computational procedure that provides a framework for automated construction of complex regression models of predefined
Influence of FRAPCON-1 evaluation models on fuel behavior calculations for commercial power reactors
International Nuclear Information System (INIS)
Chambers, R.; Laats, E.T.
1981-01-01
A preliminary set of nine evaluation models (EMs) was added to the FRAPCON-1 computer code, which is used to calculate fuel rod behavior in a nuclear reactor during steady-state operation. The intent was to provide an audit code to be used in the United States Nuclear Regulatory Commission (NRC) licensing activities when calculations of conservative fuel rod temperatures are required. The EMs place conservatisms on the calculation of rod temperature by modifying the calculation of rod power history, fuel and cladding behavior models, and materials properties correlations. Three of the nine EMs provide either input or model specifications, or set the reference temperature for stored energy calculations. The remaining six EMs were intended to add thermal conservatism through model changes. To determine the relative influence of these six EMs upon fuel behavior calculations for commercial power reactors, a sensitivity study was conducted. That study is the subject of this paper
Acceleration methods and models in Sn calculations
International Nuclear Information System (INIS)
Sbaffoni, M.M.; Abbate, M.J.
1984-01-01
In some neutron transport problems solved by the discrete ordinate method, it is relatively common to observe some particularities as, for example, negative fluxes generation, slow and insecure convergences and solution instabilities. The commonly used models for neutron flux calculation and acceleration methods included in the most used codes were analyzed, in face of their use in problems characterized by a strong upscattering effect. Some special conclusions derived from this analysis are presented as well as a new method to perform the upscattering scaling for solving the before mentioned problems in this kind of cases. This method has been included in the DOT3.5 code (two dimensional discrete ordinates radiation transport code) generating a new version of wider application. (Author) [es
Preliminary calculations of release rates from spent fuel in a tuff repository
International Nuclear Information System (INIS)
Apted, M.J.; O'Connell, W.J.; Lee, K.H.; MacIntyre, A.T.; Ueng, T.S.; Pigford, T.H.; Lee, W.W.L.
1991-01-01
Time-dependent release rates of Tc-99, I-129, Cs-135, and Np-237 have been calculated for wet-drip and moist-continuous release modes from the engineered barrier system of a potential nuclear waste repository in unsaturated tuff, representative of a possible repository at Yucca Mountain in southern Nevada. We describe the modes of water contact and of release of dissolved radionuclides to the surrounding intact rock, and the corresponding calculational models. We list the parameter values adopted, and then present numerical results, conclusions, and recommendations. 21 refs., 5 figs., 2 tabs
Preliminary Multi-Variable Parametric Cost Model for Space Telescopes
Stahl, H. Philip; Hendrichs, Todd
2010-01-01
This slide presentation reviews creating a preliminary multi-variable cost model for the contract costs of making a space telescope. There is discussion of the methodology for collecting the data, definition of the statistical analysis methodology, single variable model results, testing of historical models and an introduction of the multi variable models.
Preliminary calculations on the cooling rate of the Renca batholit, Sierra de San Luis, Argentina
International Nuclear Information System (INIS)
Lopez de Luchi, M.G.; Ostera, H.A.; Linares, E; Rosello, E.A
2001-01-01
Cooling rates can be used to constrain the unroofing history of plutonic-metamorphic system. Geocronological cooling rates (Spear and Parrish, 1996) can be unravelled using age calculations on minerals that were open systems and subsequently passed through their closure temperatures (Dodson, 1973) during cooling. Several age determinations on different minerals are needed in order to accurately constrain the cooling path of a pluton (Hodges 1991, Spear and Parrish, 1996 and references therein). Isotopic open-system behaviour in minerals can be modelled as volume diffusion process (Hodges, 1991 and references therein), which depends on the cooling rate of the whole system. We present the first results on the calculation of the cooling rate of the Renca batholith on the basis of the combination of both thermometric calculations and available crystallization and cooling ages (au)
Energy Technology Data Exchange (ETDEWEB)
Jannik, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Stagich, Brooke [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2015-08-28
The U.S. Environmental Protection Agency (EPA) requested an external, independent verification study of their updated “Preliminary Remediation Goals for Radionuclides” (PRG) electronic calculator. The calculator provides PRGs for radionuclides that are used as a screening tool at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) sites. These risk-based PRGs establish concentration limits under specific exposure scenarios. The purpose of this verification study is to determine that the calculator has no inherit numerical problems with obtaining solutions as well as to ensure that the equations are programmed correctly. There are 167 equations used in the calculator. To verify the calculator, all equations for each of seven receptor types (resident, construction worker, outdoor and indoor worker, recreator, farmer, and composite worker) were hand calculated using the default parameters. The same four radionuclides (Am-241, Co-60, H-3, and Pu-238) were used for each calculation for consistency throughout.
Preliminary results of steel containment vessel model test
International Nuclear Information System (INIS)
Matsumoto, T.; Komine, K.; Arai, S.
1997-01-01
A high pressure test of a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of a steel containment vessel (SCV), representing an improved boiling water reactor (BWR) Mark II containment, was conducted on December 11-12, 1996 at Sandia National Laboratories. This paper describes the preliminary results of the high pressure test. In addition, the preliminary post-test measurement data and the preliminary comparison of test data with pretest analysis predictions are also presented
International Nuclear Information System (INIS)
Morrison, Hali; Menon, Geetha; Sloboda, Ron
2016-01-01
Purpose: To investigate the accuracy of model-based dose calculations using a collapsed-cone algorithm for COMS eye plaques loaded with I-125 seeds. Methods: The Nucletron SelectSeed 130.002 I-125 seed and the 12 mm COMS eye plaque were incorporated into a research version of the Oncentra® Brachy v4.5 treatment planning system which uses the Advanced Collapsed-cone Engine (ACE) algorithm. Comparisons of TG-43 and high-accuracy ACE doses were performed for a single seed in a 30×30×30 cm 3 water box, as well as with one seed in the central slot of the 12 mm COMS eye plaque. The doses along the plaque central axis (CAX) were used to calculate the carrier correction factor, T(r), and were compared to tabulated and MCNP6 simulated doses for both the SelectSeed and IsoAid IAI-125A seeds. Results: The ACE calculated dose for the single seed in water was on average within 0.62 ± 2.2% of the TG-43 dose, with the largest differences occurring near the end-welds. The ratio of ACE to TG-43 calculated doses along the CAX (T(r)) of the 12 mm COMS plaque for the SelectSeed was on average within 3.0% of previously tabulated data, and within 2.9% of the MCNP6 simulated values. The IsoAid and SelectSeed T(r) values agreed within 0.3%. Conclusions: Initial comparisons show good agreement between ACE and MC doses for a single seed in a 12 mm COMS eye plaque; more complicated scenarios are being investigated to determine the accuracy of this calculation method.
Energy Technology Data Exchange (ETDEWEB)
Morrison, Hali; Menon, Geetha; Sloboda, Ron [Cross Cancer Institute, Edmonton, AB, and University of Alberta, Edmonton, AB, Cross Cancer Institute, Edmonton, AB, and University of Alberta, Edmonton, AB, Cross Cancer Institute, Edmonton, AB, and University of Alberta, Edmonton, AB (Canada)
2016-08-15
Purpose: To investigate the accuracy of model-based dose calculations using a collapsed-cone algorithm for COMS eye plaques loaded with I-125 seeds. Methods: The Nucletron SelectSeed 130.002 I-125 seed and the 12 mm COMS eye plaque were incorporated into a research version of the Oncentra® Brachy v4.5 treatment planning system which uses the Advanced Collapsed-cone Engine (ACE) algorithm. Comparisons of TG-43 and high-accuracy ACE doses were performed for a single seed in a 30×30×30 cm{sup 3} water box, as well as with one seed in the central slot of the 12 mm COMS eye plaque. The doses along the plaque central axis (CAX) were used to calculate the carrier correction factor, T(r), and were compared to tabulated and MCNP6 simulated doses for both the SelectSeed and IsoAid IAI-125A seeds. Results: The ACE calculated dose for the single seed in water was on average within 0.62 ± 2.2% of the TG-43 dose, with the largest differences occurring near the end-welds. The ratio of ACE to TG-43 calculated doses along the CAX (T(r)) of the 12 mm COMS plaque for the SelectSeed was on average within 3.0% of previously tabulated data, and within 2.9% of the MCNP6 simulated values. The IsoAid and SelectSeed T(r) values agreed within 0.3%. Conclusions: Initial comparisons show good agreement between ACE and MC doses for a single seed in a 12 mm COMS eye plaque; more complicated scenarios are being investigated to determine the accuracy of this calculation method.
Preliminary corrosion models for BWIP [Basalt Waste Isolation Project] canister materials
International Nuclear Information System (INIS)
Fish, R.L.; Anantatmula, R.P.
1983-01-01
Waste package development for the Basalt Waste Isolation Project (BWIP) requires the generation of materials degradation data under repository relevant conditions. These data are used to develop predictive models for the behavior of each component of waste package. The component models are exercised in performance analyses to optimize the waste package design. This document presents all repository relevant canister materials corrosion data that the BWIP and others have developed to date, describes the methodology used to develop preliminary corrosion models and provides the mathematical description of the models for both low carbon steel and Fe9Cr1Mo steel. Example environment/temperature history and model application calculations are presented to aid in understanding the models. The models are preliminary in nature and will be updated as additional corrosion data become available. 6 refs., 5 tabs
Concurrent algorithms for nuclear shell model calculations
International Nuclear Information System (INIS)
Mackenzie, L.M.; Macleod, A.M.; Berry, D.J.; Whitehead, R.R.
1988-01-01
The calculation of nuclear properties has proved very successful for light nuclei, but is limited by the power of the present generation of computers. Starting with an analysis of current techniques, this paper discusses how these can be modified to map parallelism inherent in the mathematics onto appropriate parallel machines. A prototype dedicated multiprocessor for nuclear structure calculations, designed and constructed by the authors, is described and evaluated. The approach adopted is discussed in the context of a number of generically similar algorithms. (orig.)
International Nuclear Information System (INIS)
Siefken, L.J.
1999-01-01
Preliminary designs are described for models of hydrogen and oxygen uptake in fuel rod cladding during severe accidents. Calculation of the uptake involves the modeling of seven processes: (1) diffusion of oxygen from the bulk gas into the boundary layer at the external cladding surface, (2) diffusion from the boundary layer into the oxide layer, (3) diffusion from the inner surface of the oxide layer into the metallic part of the cladding, (4) uptake of hydrogen in the event that the cladding oxide layer is dissolved in a steam-starved region, (5) embrittlement of cladding due to hydrogen uptake, (6) cracking of cladding during quenching due to its embrittlement and (7) release of hydrogen from the cladding after cracking of the cladding. An integral diffusion method is described for calculating the diffusion processes in the cladding. Experimental results are presented that show a rapid uptake of hydrogen in the event of dissolution of the oxide layer and a rapid release of hydrogen in the event of cracking of the oxide layer. These experimental results are used as a basis for calculating the rate of hydrogen uptake and the rate of hydrogen release. The uptake of hydrogen is limited to the equilibrium solubility calculated by applying Sievert's law. The uptake of hydrogen is an exothermic reaction that accelerates the heatup of a fuel rod. An embrittlement criteria is described that accounts for hydrogen and oxygen concentration and the extent of oxidation. A design is described for implementing the models for hydrogen and oxygen uptake and cladding embrittlement into the programming framework of the SCDAP/RELAP5 code. A test matrix is described for assessing the impact of the proposed models on the calculated behavior of fuel rods in severe accident conditions. This report is a revision and reissue of the report entitled; ''Preliminary Design Report for Modeling of Hydrogen Uptake in Fuel Rod Cladding During Severe Accidents.''
Shell model calculations for exotic nuclei
International Nuclear Information System (INIS)
Brown, B.A.; Wildenthal, B.H.
1991-01-01
A review of the shell-model approach to understanding the properties of light exotic nuclei is given. Binding energies including p and p-sd model spaces and sd and sd-pf model spaces; cross-shell excitations around 32 Mg, including weak-coupling aspects and mechanisms for lowering the ntw excitations; beta decay properties of neutron-rich sd model, of p-sd and sd-pf model spaces, of proton-rich sd model space; coulomb break-up cross sections are discussed. (G.P.) 76 refs.; 12 figs
Energy Technology Data Exchange (ETDEWEB)
Campolina, Daniel; Costa, Antonio Carlos L. da; Andrade, Edison P., E-mail: campolina@cdtn.br, E-mail: aclp@cdtn.br, E-mail: epa@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (SETRE/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Tecnologia de Reatores
2017-07-01
The structuring project of the Brazilian Multipurpose Reactor (RMB) is responsible for meeting the capacity to develop and test materials and nuclear fuel for the Brazilian Nuclear Program. An irradiation test device (Loop) capable of performing fuel test for power reactor rods is being conceived for RMB reflector. In this work preliminary neutronic calculations have been carried out in order to determine parameters to the cooling system of the Loop basic design. The heat released as a result of radioactive decay of fuel samples was calculated using ORIGEN-ARP and it resulted less than 200 W after 1 hour of irradiation interruption. (author)
Uncertainty calculation in transport models and forecasts
DEFF Research Database (Denmark)
Manzo, Stefano; Prato, Carlo Giacomo
Transport projects and policy evaluations are often based on transport model output, i.e. traffic flows and derived effects. However, literature has shown that there is often a considerable difference between forecasted and observed traffic flows. This difference causes misallocation of (public...... implemented by using an approach based on stochastic techniques (Monte Carlo simulation and Bootstrap re-sampling) or scenario analysis combined with model sensitivity tests. Two transport models are used as case studies: the Næstved model and the Danish National Transport Model. 3 The first paper...... in a four-stage transport model related to different variable distributions (to be used in a Monte Carlo simulation procedure), assignment procedures and levels of congestion, at both the link and the network level. The analysis used as case study the Næstved model, referring to the Danish town of Næstved2...
Preliminary Multivariable Cost Model for Space Telescopes
Stahl, H. Philip
2010-01-01
Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. Previously, the authors published two single variable cost models based on 19 flight missions. The current paper presents the development of a multi-variable space telescopes cost model. The validity of previously published models are tested. Cost estimating relationships which are and are not significant cost drivers are identified. And, interrelationships between variables are explored
Shell model calculations at superdeformed shapes
International Nuclear Information System (INIS)
Nazarewicz, W.; Dobaczewski, J.; Van Isacker, P.
1991-01-01
Spectroscopy of superdeformed nuclear states opens up an exciting possibility to probe new properties of the nuclear mean field. In particular, the unusually deformed atomic nucleus can serve as a microscopic laboratory of quantum-mechanical symmetries of a three dimensional harmonic oscillator. The classifications and coupling schemes characteristic of weakly deformed systems are expected to be modified in the superdeformed world. The ''superdeformed'' symmetries lead to new quantum numbers and new effective interactions that can be employed in microscopic calculations. New classification schemes can be directly related to certain geometrical properties of the nuclear shape. 63 refs., 7 figs
V and V Efforts of Auroral Precipitation Models: Preliminary Results
Zheng, Yihua; Kuznetsova, Masha; Rastaetter, Lutz; Hesse, Michael
2011-01-01
Auroral precipitation models have been valuable both in terms of space weather applications and space science research. Yet very limited testing has been performed regarding model performance. A variety of auroral models are available, including empirical models that are parameterized by geomagnetic indices or upstream solar wind conditions, now casting models that are based on satellite observations, or those derived from physics-based, coupled global models. In this presentation, we will show our preliminary results regarding V&V efforts of some of the models.
Models for Automated Tube Performance Calculations
International Nuclear Information System (INIS)
Brunkhorst, C.
2002-01-01
High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance
Beyond standard model calculations with Sherpa
Energy Technology Data Exchange (ETDEWEB)
Hoeche, Stefan [SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Kuttimalai, Silvan [Durham University, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Schumann, Steffen [Universitaet Goettingen, II. Physikalisches Institut, Goettingen (Germany); Siegert, Frank [Institut fuer Kern- und Teilchenphysik, TU Dresden, Dresden (Germany)
2015-03-01
We present a fully automated framework as part of the Sherpa event generator for the computation of tree-level cross sections in Beyond Standard Model scenarios, making use of model information given in the Universal FeynRules Output format. Elementary vertices are implemented into C++ code automatically and provided to the matrix-element generator Comix at runtime. Widths and branching ratios for unstable particles are computed from the same building blocks. The corresponding decays are simulated with spin correlations. Parton showers, QED radiation and hadronization are added by Sherpa, providing a full simulation of arbitrary BSM processes at the hadron level. (orig.)
International Nuclear Information System (INIS)
Yan Guanghua; Liu, Chihray; Lu Bo; Palta, Jatinder R; Li, Jonathan G
2008-01-01
The purpose of this study was to choose an appropriate head scatter source model for the fast and accurate independent planar dose calculation for intensity-modulated radiation therapy (IMRT) with MLC. The performance of three different head scatter source models regarding their ability to model head scatter and facilitate planar dose calculation was evaluated. A three-source model, a two-source model and a single-source model were compared in this study. In the planar dose calculation algorithm, in-air fluence distribution was derived from each of the head scatter source models while considering the combination of Jaw and MLC opening. Fluence perturbations due to tongue-and-groove effect, rounded leaf end and leaf transmission were taken into account explicitly. The dose distribution was calculated by convolving the in-air fluence distribution with an experimentally determined pencil-beam kernel. The results were compared with measurements using a diode array and passing rates with 2%/2 mm and 3%/3 mm criteria were reported. It was found that the two-source model achieved the best agreement on head scatter factor calculation. The three-source model and single-source model underestimated head scatter factors for certain symmetric rectangular fields and asymmetric fields, but similar good agreement could be achieved when monitor back scatter effect was incorporated explicitly. All the three source models resulted in comparable average passing rates (>97%) when the 3%/3 mm criterion was selected. The calculation with the single-source model and two-source model was slightly faster than the three-source model due to their simplicity
Energy Technology Data Exchange (ETDEWEB)
Yan Guanghua [Department of Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Liu, Chihray; Lu Bo; Palta, Jatinder R; Li, Jonathan G [Department of Radiation Oncology, University of Florida, Gainesville, FL 32610-0385 (United States)
2008-04-21
The purpose of this study was to choose an appropriate head scatter source model for the fast and accurate independent planar dose calculation for intensity-modulated radiation therapy (IMRT) with MLC. The performance of three different head scatter source models regarding their ability to model head scatter and facilitate planar dose calculation was evaluated. A three-source model, a two-source model and a single-source model were compared in this study. In the planar dose calculation algorithm, in-air fluence distribution was derived from each of the head scatter source models while considering the combination of Jaw and MLC opening. Fluence perturbations due to tongue-and-groove effect, rounded leaf end and leaf transmission were taken into account explicitly. The dose distribution was calculated by convolving the in-air fluence distribution with an experimentally determined pencil-beam kernel. The results were compared with measurements using a diode array and passing rates with 2%/2 mm and 3%/3 mm criteria were reported. It was found that the two-source model achieved the best agreement on head scatter factor calculation. The three-source model and single-source model underestimated head scatter factors for certain symmetric rectangular fields and asymmetric fields, but similar good agreement could be achieved when monitor back scatter effect was incorporated explicitly. All the three source models resulted in comparable average passing rates (>97%) when the 3%/3 mm criterion was selected. The calculation with the single-source model and two-source model was slightly faster than the three-source model due to their simplicity.
Utility of Social Modeling for Proliferation Assessment - Preliminary Assessment
Energy Technology Data Exchange (ETDEWEB)
Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.
2009-06-01
This Preliminary Assessment draft report will present the results of a literature search and preliminary assessment of the body of research, analysis methods, models and data deemed to be relevant to the Utility of Social Modeling for Proliferation Assessment research. This report will provide: 1) a description of the problem space and the kinds of information pertinent to the problem space, 2) a discussion of key relevant or representative literature, 3) a discussion of models and modeling approaches judged to be potentially useful to the research, and 4) the next steps of this research that will be pursued based on this preliminary assessment. This draft report represents a technical deliverable for the NA-22 Simulations, Algorithms, and Modeling (SAM) program. Specifically this draft report is the Task 1 deliverable for project PL09-UtilSocial-PD06, Utility of Social Modeling for Proliferation Assessment. This project investigates non-traditional use of social and cultural information to improve nuclear proliferation assessment, including nonproliferation assessment, proliferation resistance assessments, safeguards assessments and other related studies. These assessments often use and create technical information about the State’s posture towards proliferation, the vulnerability of a nuclear energy system to an undesired event, and the effectiveness of safeguards. This project will find and fuse social and technical information by explicitly considering the role of cultural, social and behavioral factors relevant to proliferation. The aim of this research is to describe and demonstrate if and how social science modeling has utility in proliferation assessment.
Model calculations for electrochemically etched neutron detectors
International Nuclear Information System (INIS)
Pitt, E.; Scharmann, A.; Werner, B.
1988-01-01
Electrochemical etching has been established as a common method for visualisation of nuclear tracks in solid state nuclear track detectors. Usually the Mason equation, which describes the amplification of the electrical field strength at the track tip, is used to explain the treeing effect of electrochemical etching. The yield of neutron-induced tracks from electrochemically etched CR-39 track detectors was investigated with respect to the electrical parameters. A linear dependence on the response from the macroscopic field strength was measured which could not be explained by the Mason equation. It was found that the reality of a recoil proton track in the detector does not fit the boundary conditions which are necessary when the Mason equation is used. An alternative model was introduced to describe the track and detector geometry in the case of a neutron track detector. The field strength at the track tip was estimated with this model and compared with the experimental data, yielding good agreement. (author)
Preliminary report on electromagnetic model studies
Frischknecht, F.C.; Mangan, G.B.
1960-01-01
More than 70 resopnse curves for various models have been obtained using the slingram and turam electromagnetic methods. Results show that for the slingram method, horizontal co-planar coils are usually more sensitive than vertical, co-axial or vertical, co-planar coils. The shape of the anomaly usually is simpler for the vertical coils.
Model calculation of thermal conductivity in antiferromagnets
Energy Technology Data Exchange (ETDEWEB)
Mikhail, I.F.I., E-mail: ifi_mikhail@hotmail.com; Ismail, I.M.M.; Ameen, M.
2015-11-01
A theoretical study is given of thermal conductivity in antiferromagnetic materials. The study has the advantage that the three-phonon interactions as well as the magnon phonon interactions have been represented by model operators that preserve the important properties of the exact collision operators. A new expression for thermal conductivity has been derived that involves the same terms obtained in our previous work in addition to two new terms. These two terms represent the conservation and quasi-conservation of wavevector that occur in the three-phonon Normal and Umklapp processes respectively. They gave appreciable contributions to the thermal conductivity and have led to an excellent quantitative agreement with the experimental measurements of the antiferromagnet FeCl{sub 2}. - Highlights: • The Boltzmann equations of phonons and magnons in antiferromagnets have been studied. • Model operators have been used to represent the magnon–phonon and three-phonon interactions. • The models possess the same important properties as the exact operators. • A new expression for the thermal conductivity has been derived. • The results showed a good quantitative agreement with the experimental data of FeCl{sub 2}.
Preliminary Development of Regulatory PSA Models for SFR
International Nuclear Information System (INIS)
Choi, Yong Won; Shin, Andong; Bae, Moohoon; Suh, Namduk; Lee, Yong Suk
2013-01-01
Well developed PRA methodology exists for LWR (Light Water Reactor) and PHWR (Pressurized Heavy Water Reactor). Since KAERI is developing a prototype SFR targeting to apply for a license by 2017, KINS needs to have a PRA models to assess the safety of this prototype reactor. The purpose of this study is to develop the regulatory PSA models for the independent verification of the SFR safety. Since the design of the prototype SFR is not mature yet, we have tried to develop the preliminary models based on the design data of KAERI's previous SFR design. In this study, the preliminary initiating events of level 1 internal event for SFR were selected through reviews of existing PRA (LWR, PRISM, ASTRID and KALIMER-600) models. Then, the event tree for each selected initiating event was developed. The regulatory PRA models of SFR developed are preliminary in a sense, because the prototype SFR design is not mature and provided yet. Still it might be utilized for the forthcoming licensing review in assessing the risk of safety issues and the configuration control of the design
Modelling Extortion Racket Systems: Preliminary Results
Nardin, Luis G.; Andrighetto, Giulia; Székely, Áron; Conte, Rosaria
Mafias are highly powerful and deeply entrenched organised criminal groups that cause both economic and social damage. Overcoming, or at least limiting, their harmful effects is a societally beneficial objective, which renders its dynamics understanding an objective of both scientific and political interests. We propose an agent-based simulation model aimed at understanding how independent and combined effects of legal and social norm-based processes help to counter mafias. Our results show that legal processes are effective in directly countering mafias by reducing their activities and changing the behaviour of the rest of population, yet they are not able to change people's mind-set that renders the change fragile. When combined with social norm-based processes, however, people's mind-set shifts towards a culture of legality rendering the observed behaviour resilient to change.
Standard Model theory calculations and experimental tests
International Nuclear Information System (INIS)
Cacciari, M.; Hamel de Monchenault, G.
2015-01-01
To present knowledge, all the physics at the Large Hadron Collider (LHC) can be described in the framework of the Standard Model (SM) of particle physics. Indeed the newly discovered Higgs boson with a mass close to 125 GeV seems to confirm the predictions of the SM. Thus, besides looking for direct manifestations of the physics beyond the SM, one of the primary missions of the LHC is to perform ever more stringent tests of the SM. This requires not only improved theoretical developments to produce testable predictions and provide experiments with reliable event generators, but also sophisticated analyses techniques to overcome the formidable experimental environment of the LHC and perform precision measurements. In the first section, we describe the state of the art of the theoretical tools and event generators that are used to provide predictions for the production cross sections of the processes of interest. In section 2, inclusive cross section measurements with jets, leptons and vector bosons are presented. Examples of differential cross sections, charge asymmetries and the study of lepton pairs are proposed in section 3. Finally, in section 4, we report studies on the multiple production of gauge bosons and constraints on anomalous gauge couplings
Preliminary Calculation for Plasma Chamber Design of Pulsed Electron Source Based on Plasma
International Nuclear Information System (INIS)
Widdi Usada
2009-01-01
This paper described the characteristics of pulsed electron sources with anode-cathode distance of 5 cm, electrode diameter of 10 cm, driven by capacitor energy of 25 J. The preliminary results showed that if the system is operated with diode resistance is 1.6 Ω, plasma resistance is 0.14 Ω, and β is 0.94, the achieved of plasma voltage is 640 V, its current is 4.395 kA with its pulse width of 0.8 μsecond. According to breakdown voltage based on Paschen empirical formula, with this achieved voltage, this system could be operated for operation pressure of 1 torr. (author)
Preliminary Multi-Variable Cost Model for Space Telescopes
Stahl, H. Philip; Hendrichs, Todd
2010-01-01
Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. This paper reviews the methodology used to develop space telescope cost models; summarizes recently published single variable models; and presents preliminary results for two and three variable cost models. Some of the findings are that increasing mass reduces cost; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and technology development as a function of time reduces cost at the rate of 50% per 17 years.
International Nuclear Information System (INIS)
Ho, C.K.; Altman, S.J.; Arnold, B.W.
1995-09-01
Groundwater travel time (GWTT) calculations will play an important role in addressing site-suitability criteria for the potential high-level nuclear waste repository at Yucca Mountain,Nevada. In support of these calculations, Preliminary assessments of the candidate codes and models are presented in this report. A series of benchmark studies have been designed to address important aspects of modeling flow through fractured media representative of flow at Yucca Mountain. Three codes (DUAL, FEHMN, and TOUGH 2) are compared in these benchmark studies. DUAL is a single-phase, isothermal, two-dimensional flow simulator based on the dual mixed finite element method. FEHMN is a nonisothermal, multiphase, multidimensional simulator based primarily on the finite element method. TOUGH2 is anon isothermal, multiphase, multidimensional simulator based on the integral finite difference method. Alternative conceptual models of fracture flow consisting of the equivalent continuum model (ECM) and the dual permeability (DK) model are used in the different codes
Swartjes F; ECO
2003-01-01
Twenty scenarios, differing with respect to land use, soil type and contaminant, formed the basis for calculating human exposure from soil contaminants with the use of models contributed by seven European countries (one model per country). Here, the human exposures to children and children
International Nuclear Information System (INIS)
Baguena, A.; Shaw, M.; Williart, A.; Baguena, A.; Garcia, G.
2006-01-01
We describe the calculations and preliminary measures made for the installation of a X-ray generator tube. This device is going to be used for the secondary electron production from photonic primary radiation of up to 125 keV. With this experimental system, we will study the energetic and space distribution of produced secondary electrons by obtaining its spectrum of energies and its angular distribution. This method of measurement is going to be applied in different targets of radiological, environmental and biological interest. Calculations in the present article include: theoretical yield of X-rays production of the designed equipment, necessary shielding for the radiological safety of the installation staff, and an estimated dose due to their use. Characteristics of the installation and the equipment are described with this purpose. (author)
Energy Technology Data Exchange (ETDEWEB)
Baguena, A.; Shaw, M.; Williart, A. [Universidad Nacional de Educacion a Distancia, Dpto. Fisica de los Materiales, Madrid (Spain); Baguena, A. [Consejo de Seguridad Nuclear, Madrid (Spain); Garcia, G. [Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Madrid (Spain)
2006-07-01
We describe the calculations and preliminary measures made for the installation of a X-ray generator tube. This device is going to be used for the secondary electron production from photonic primary radiation of up to 125 keV. With this experimental system, we will study the energetic and space distribution of produced secondary electrons by obtaining its spectrum of energies and its angular distribution. This method of measurement is going to be applied in different targets of radiological, environmental and biological interest. Calculations in the present article include: theoretical yield of X-rays production of the designed equipment, necessary shielding for the radiological safety of the installation staff, and an estimated dose due to their use. Characteristics of the installation and the equipment are described with this purpose. (author)
Precipitates/Salts Model Calculations for Various Drift Temperature Environments
International Nuclear Information System (INIS)
Marnier, P.
2001-01-01
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation within a repository drift. This work is developed and documented using procedure AP-3.12Q, Calculations, in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The primary objective of this calculation is to predict the effects of evaporation on the abstracted water compositions established in ''EBS Incoming Water and Gas Composition Abstraction Calculations for Different Drift Temperature Environments'' (BSC 2001c). A secondary objective is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b)
DIGA/NSL new calculational model in slab geometry
International Nuclear Information System (INIS)
Makai, M.; Gado, J.; Kereszturi, A.
1987-04-01
A new calculational model is presented based on a modified finite-difference algorithm, in which the coefficients are determined by means of the so-called gamma matrices. The DIGA program determines the gamma matrices and the NSL program realizes the modified finite difference model. Both programs assume slab cell geometry, DIGA assumes 2 energy groups and 3 diffusive regions. The DIGA/NSL programs serve to study the new calculational model. (author)
A Preliminary Study on Calculation of Inter-Pebble Dancoff Factor in a Pebble Type Core
International Nuclear Information System (INIS)
Kim, Song Hyun; Kim, Hong Chul; Kim, Soon Young; Noh, Jae Man; Kim, Jong Kyung
2009-01-01
The Dancoff factor is an entering probability of the neutron escaped from specific fuel kernel to another one without the interaction with moderators. Currently, Dancoff factors are mainly evaluated from stochastic methods, hence a research on analytical method is considerably insufficient in this field. In order to analytically evaluate Dancoff factor considering double-heterogeneous effect, inter-pebble and intra-pebble Dancoff factors should be calculated, respectively. Intra-pebble Dancoff factor related with the fuel kernels in one pebble was analyzed in past study. For the evaluation of inter-pebble Dancoff factor, fuel region to region Dancoff factor (FRDF) was defined and the method to calculate the FRDF is developed in this study. The result is compared with the calculation result of the MCNP5 code
A universal calculation model for the controlled electric transmission line
International Nuclear Information System (INIS)
Zivzivadze, O.; Zivzivadze, L.
2009-01-01
Difficulties associated with the development of calculation models are analyzed, and the ways of resolution of these problems are given. A version of the equivalent circuit as a six-pole network, the parameters of which do not depend on the angle of shift Θ between the voltage vectors of circuits is offered. The interrelation between the parameters of the equivalent circuit and the transmission constants of the line was determined. A universal calculation model for the controlled electric transmission line was elaborated. The model allows calculating the stationary modes of lines of such classes at any angle of shift Θ between the circuits. (author)
ECP evaluation by water radiolysis and ECP model calculations
Energy Technology Data Exchange (ETDEWEB)
Hanawa, S.; Nakamura, T.; Uchida, S. [Japan Atomic Energy Agency, Tokai-mura, Ibaraki (Japan); Kus, P.; Vsolak, R.; Kysela, J. [Nuclear Research Inst. Rez plc, Rez (Czech Republic)
2010-07-01
In-pile ECP measurements data was evaluated by water radiolysis calculations. The data was obtained by using an in-pile loop in an experimental reactor, LVR-15, at the Nuclear Research Institute (NRI) in Czech Republic. Three types of ECP sensors, a Pt electrode, an Ag/AgCl sensor and a zirconia membrane sensor containing Ag/Ag{sub 2}O were used at several levels of the irradiation rig at various neutron flux and gamma rates. For water radiolysis calculation, the in-pile loop was modeled to several nodes following their design specifications, operating conditions such as flow rates, dose rate distributions of neutron and gamma-ray and so on. Concentration of chemical species along the water flow was calculated by a radiolysis code, WRAC-J. The radiolysis calculation results were transferred to an ECP model. In the model, anodic and cathodic current densities were calculated with combination of an electrochemistry model and an oxide film growth model. The measured ECP data were compared with the radiolysis/ECP calculation results, and applicability the of radiolysis model was confirmed. In addition, anomalous phenomenon appears in the in-pile loop was also investigated by radiolysis calculations. (author)
International Nuclear Information System (INIS)
Cheong, Jae Hak; Park, Won Jae
2003-01-01
As a follow up to the Agenda 21's policy statement for safe management of radioactive waste adopted at Rio Conference held in 1992, the UN invited the IAEA to develop and implement indicators of sustainable development for the management of radioactive waste. The IAEA finalized the indicators in 2002, and is planning to calculate the member states' values of indicators in connection with operation of its Net-Enabled Waste Management Database system. In this paper, the basis for introducing the indicators into the radioactive waste management was analyzed, and calculation methodology and standard assessment procedure were simply depicted. In addition, a series of innate limitations in calculation and comparison of the indicators was analyzed. According to the proposed standard procedure, the indicators for a few major countries including Korea were calculated and compared, by use of each country's radioactive waste management framework and its practices. In addition, a series of measures increasing the values of the indicators was derived so as to enhance the sustainability of domestic radioactive waste management program.
Comparative calculations and validation studies with atmospheric dispersion models
International Nuclear Information System (INIS)
Paesler-Sauer, J.
1986-11-01
This report presents the results of an intercomparison of different mesoscale dispersion models and measured data of tracer experiments. The types of models taking part in the intercomparison are Gaussian-type, numerical Eulerian, and Lagrangian dispersion models. They are suited for the calculation of the atmospherical transport of radionuclides released from a nuclear installation. For the model intercomparison artificial meteorological situations were defined and corresponding arithmetical problems were formulated. For the purpose of model validation real dispersion situations of tracer experiments were used as input data for model calculations; in these cases calculated and measured time-integrated concentrations close to the ground are compared. Finally a valuation of the models concerning their efficiency in solving the problems is carried out by the aid of objective methods. (orig./HP) [de
Model calculations of nuclear data for biologically-important elements
International Nuclear Information System (INIS)
Chadwick, M.B.; Blann, M.; Reffo, G.; Young, P.G.
1994-05-01
We describe calculations of neutron-induced reactions on carbon and oxygen for incident energies up to 70 MeV, the relevant clinical energy in radiation neutron therapy. Our calculations using the FKK-GNASH, GNASH, and ALICE codes are compared with experimental measurements, and their usefulness for modeling reactions on biologically-important elements is assessed
In-Drift Microbial Communities Model Validation Calculations
Energy Technology Data Exchange (ETDEWEB)
D. M. Jolley
2001-09-24
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data.
In-Drift Microbial Communities Model Validation Calculation
Energy Technology Data Exchange (ETDEWEB)
D. M. Jolley
2001-10-31
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data.
IN-DRIFT MICROBIAL COMMUNITIES MODEL VALIDATION CALCULATIONS
Energy Technology Data Exchange (ETDEWEB)
D.M. Jolley
2001-12-18
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M&O 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M&O 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN M09909SPAMINGl.003 using its replacement DTN M00106SPAIDMO 1.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M&O (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 200 1) which includes controls for the management of electronic data.
In-Drift Microbial Communities Model Validation Calculations
International Nuclear Information System (INIS)
Jolley, D.M.
2001-01-01
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS MandO 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS MandO 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN MO9909SPAMING1.003 using its replacement DTN MO0106SPAIDM01.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS MandO 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS MandO (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 2001) which includes controls for the management of electronic data
IN-DRIFT MICROBIAL COMMUNITIES MODEL VALIDATION CALCULATIONS
International Nuclear Information System (INIS)
D.M. Jolley
2001-01-01
The objective and scope of this calculation is to create the appropriate parameter input for MING 1.0 (CSCI 30018 V1.0, CRWMS M andO 1998b) that will allow the testing of the results from the MING software code with both scientific measurements of microbial populations at the site and laboratory and with natural analogs to the site. This set of calculations provides results that will be used in model validation for the ''In-Drift Microbial Communities'' model (CRWMS M andO 2000) which is part of the Engineered Barrier System Department (EBS) process modeling effort that eventually will feed future Total System Performance Assessment (TSPA) models. This calculation is being produced to replace MING model validation output that is effected by the supersession of DTN M09909SPAMINGl.003 using its replacement DTN M00106SPAIDMO 1.034 so that the calculations currently found in the ''In-Drift Microbial Communities'' AMR (CRWMS M andO 2000) will be brought up to date. This set of calculations replaces the calculations contained in sections 6.7.2, 6.7.3 and Attachment I of CRWMS M andO (2000) As all of these calculations are created explicitly for model validation, the data qualification status of all inputs can be considered corroborative in accordance with AP-3.15Q. This work activity has been evaluated in accordance with the AP-2.21 procedure, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', and is subject to QA controls (BSC 2001). The calculation is developed in accordance with the AP-3.12 procedure, Calculations, and prepared in accordance with the ''Technical Work Plan For EBS Department Modeling FY 01 Work Activities'' (BSC 200 1) which includes controls for the management of electronic data
Hualien forced vibration calculation with a finite element model
International Nuclear Information System (INIS)
Wang, F.; Gantenbein, F.; Nedelec, M.; Duretz, Ch.
1995-01-01
The forced vibration tests of the Hualien mock-up were useful to validate finite element models developed for soil-structure interaction. In this paper the two sets of tests with and without backfill were analysed. the methods used are based on finite element modeling for the soil. Two approaches were considered: calculation of soil impedance followed by the calculation of the transfer functions with a model taking into account the superstructure and the impedance; direct calculation of the soil-structure transfer functions, with the soil and the structure being represented in the same model by finite elements. Blind predictions and post-test calculations are presented and compared with the test results. (author). 4 refs., 8 figs., 2 tabs
The accuracy of heavy ion optical model calculations
International Nuclear Information System (INIS)
Kozik, T.
1980-01-01
There is investigated in detail the sources and magnitude of numerical errors in heavy ion optical model calculations. It is shown on example of 20 Ne + 24 Mg scattering at Esub(LAB)=100 MeV. (author)
NLOM - a program for nonlocal optical model calculations
International Nuclear Information System (INIS)
Kim, B.T.; Kyum, M.C.; Hong, S.W.; Park, M.H.; Udagawa, T.
1992-01-01
A FORTRAN program NLOM for nonlocal optical model calculations is described. It is based on a method recently developed by Kim and Udagawa, which utilizes the Lanczos technique for solving integral equations derived from the nonlocal Schroedinger equation. (orig.)
Experimental evaluation of analytical penumbra calculation model for wobbled beams
International Nuclear Information System (INIS)
Kohno, Ryosuke; Kanematsu, Nobuyuki; Yusa, Ken; Kanai, Tatsuaki
2004-01-01
The goal of radiotherapy is not only to apply a high radiation dose to a tumor, but also to avoid side effects in the surrounding healthy tissue. Therefore, it is important for carbon-ion treatment planning to calculate accurately the effects of the lateral penumbra. In this article, for wobbled beams under various irradiation conditions, we focus on the lateral penumbras at several aperture positions of one side leaf of the multileaf collimator. The penumbras predicted by an analytical penumbra calculation model were compared with the measured results. The results calculated by the model for various conditions agreed well with the experimental ones. In conclusion, we found that the analytical penumbra calculation model could predict accurately the measured results for wobbled beams and it was useful for carbon-ion treatment planning to apply the model
A methodology for constructing the calculation model of scientific spreadsheets
Vos, de M.; Wielemaker, J.; Schreiber, G.; Wielinga, B.; Top, J.L.
2015-01-01
Spreadsheets models are frequently used by scientists to analyze research data. These models are typically described in a paper or a report, which serves as single source of information on the underlying research project. As the calculation workflow in these models is not made explicit, readers are
Mathematical models for calculating radiation dose to the fetus
International Nuclear Information System (INIS)
Watson, E.E.
1992-01-01
Estimates of radiation dose from radionuclides inside the body are calculated on the basis of energy deposition in mathematical models representing the organs and tissues of the human body. Complex models may be used with radiation transport codes to calculate the fraction of emitted energy that is absorbed in a target tissue even at a distance from the source. Other models may be simple geometric shapes for which absorbed fractions of energy have already been calculated. Models of Reference Man, the 15-year-old (Reference Woman), the 10-year-old, the five-year-old, the one-year-old, and the newborn have been developed and used for calculating specific absorbed fractions (absorbed fractions of energy per unit mass) for several different photon energies and many different source-target combinations. The Reference woman model is adequate for calculating energy deposition in the uterus during the first few weeks of pregnancy. During the course of pregnancy, the embryo/fetus increases rapidly in size and thus requires several models for calculating absorbed fractions. In addition, the increases in size and changes in shape of the uterus and fetus result in the repositioning of the maternal organs and in different geometric relationships among the organs and the fetus. This is especially true of the excretory organs such as the urinary bladder and the various sections of the gastrointestinal tract. Several models have been developed for calculating absorbed fractions of energy in the fetus, including models of the uterus and fetus for each month of pregnancy and complete models of the pregnant woman at the end of each trimester. In this paper, the available models and the appropriate use of each will be discussed. (Author) 19 refs., 7 figs
Preliminary assessment of PWR Steam Generator modelling in RELAP5/MOD3
International Nuclear Information System (INIS)
Preece, R.J.; Putney, J.M.
1993-07-01
A preliminary assessment of Steam Generator (SG) modelling in the PWR thermal-hydraulic code RELAP5/MOD3 is presented. The study is based on calculations against a series of steady-state commissioning tests carried out on the Wolf Creek PWR over a range of load conditions. Data from the tests are used to assess the modelling of primary to secondary side heat transfer and, in particular, to examine the effect of reverting to the standard form of the Chen heat transfer correlation in place of the modified form applied in RELAP5/MOD2. Comparisons between the two versions of the code are also used to show how the new interphase drag model in RELAP5/MOD3 affects the calculation of SG liquid inventory and the void fraction profile in the riser
A preliminary model for estimating the first wall lifetime of a fusion reactor
International Nuclear Information System (INIS)
Daenner, W.
1975-02-01
The estimation of the first wall lifetime is a necessary basis for predicting the availability of a fusion power plant. In order to do this, an analytical model was prepared and programmed for the computer which calculates the temperature and stress load of the first wall from the principal design parameters and quotes them against the relevant material properties. Neither the analytical model nor the information about the material performance is yet complete so that the answers obtained from the program are very preliminary. This situation is underlined by the results of sample calculations performed for the CTRD blanket module cell. The results obtained for vanadium and vanadium alloys show a strong dependence of the lifetime on the irradiation creep and the ductility of these materials. Completion of this model is envisaged as soon as the missing information becomes available. (orig.) [de
Vries, de W.; Bakker, D.J.
1996-01-01
Methodologies are described for calculating critical loads of lead, cadmium, copper, zinc, nickel, chromium and mercury for soils and surface waters. The aspects which are discussed are: selection of a computation model, determination of environmental-quality criteria for the metals, collection of
Modeling and Testing of EVs - Preliminary Study and Laboratory Development
DEFF Research Database (Denmark)
Yang, Guang-Ya; Marra, Francesco; Nielsen, Arne Hejde
2010-01-01
Electric vehicles (EVs) are expected to play a key role in the future energy management system to stabilize both supply and consumption with the presence of high penetration of renewable generation. A reasonably accurate model of battery is a key element for the study of EVs behavior and the grid...... tests, followed by the suggestions towards a feasible battery model for further studies.......Electric vehicles (EVs) are expected to play a key role in the future energy management system to stabilize both supply and consumption with the presence of high penetration of renewable generation. A reasonably accurate model of battery is a key element for the study of EVs behavior and the grid...... impact at different geographical areas, as well as driving and charging patterns. Electric circuit model is deployed in this work to represent the electrical properties of a lithium-ion battery. This paper reports the preliminary modeling and validation work based on manufacturer data sheet and realistic...
Model for calculating the boron concentration in PWR type reactors
International Nuclear Information System (INIS)
Reis Martins Junior, L.L. dos; Vanni, E.A.
1986-01-01
A PWR boron concentration model has been developed for use with RETRAN code. The concentration model calculates the boron mass balance in the primary circuit as the injected boron mixes and is transported through the same circuit. RETRAN control blocks are used to calculate the boron concentration in fluid volumes during steady-state and transient conditions. The boron reactivity worth is obtained from the core concentration and used in RETRAN point kinetics model. A FSAR type analysis of a Steam Line Break Accident in Angra I plant was selected to test the model and the results obtained indicate a sucessfull performance. (Author) [pt
Preliminary results on food consumption rates for off-site dose calculation of nuclear power plants
International Nuclear Information System (INIS)
Lee, Gab Bock; Chung, Yang Geun; Bang, Sun Young; Kang, Duk Won
2005-01-01
The Internal dose by food consumption mostly account for radiological dose of public around nuclear power plants(NPP). But, food consumption rate applied to off-site dose calculation in Korea which is the result of field investigation around Kori NPP by the KAERI in 1988. is not reflected of the latest dietary characteristics. The Ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. To update the food consumption rates of the maximum individual, the analysis of the national food investigation results and field surveys around nuclear power plant sites have been carried out
Review of SFR Design Safety using Preliminary Regulatory PSA Model
International Nuclear Information System (INIS)
Na, Hyun Ju; Lee, Yong Suk; Shin, Andong; Suh, Nam Duk
2013-01-01
The major objective of this research is to develop a risk model for regulatory verification of the SFR design, and thereby, make sure that the SFR design is adequate from a risk perspective. In this paper, the development result of preliminary regulatory PSA model of SFR is discussed. In this paper, development and quantification result of preliminary regulatory PSA model of SFR is discussed. It was confirmed that the importance PDRC and ADRC dampers is significant as stated in the result of KAERI PSA model. However, the importance can be changed significantly depending on assumption of CCCG and CCF factor of PDRC and ADRC dampers. SFR (sodium-cooled fast reactor) which is Gen-IV nuclear energy system, is designed to accord with the concept of stability, sustainability and proliferation resistance. KALIMER-600, which is under development in Korea, includes passive safety systems (e. g. passive reactor shutdown, passive residual heat removal, and etc.) as well as active safety systems. Risk analysis from a regulatory perspective is needed to support the regulatory body in its safety and licensing review for SFR (KALIMER-600). Safety issues should be identified in the early design phase in order to prevent the unexpected cost increase and delay of the SFR licensing schedule that may be caused otherwise
International Nuclear Information System (INIS)
Kim, In Young; Choi, Heui Joo; Cho, Dong Geun
2013-01-01
The primary function of any repository is to prevent spreading of dangerous materials into surrounding environment. In the case of high-level radioactive waste repository, radioactive material must be isolated and retarded during sufficient decay time to minimize radiation hazard to human and surrounding environment. Sub-criticality of disposal canister and whole disposal system is minimum requisite to prevent multiplication of radiation hazard. In this study, criticality of disposal canister and DBD system for trans-metal waste is calculated to check compliance of sub-criticality. Preliminary calculation on criticality of conceptual deep borehole disposal system and its canister for trans-metal waste during operational phase is conducted in this study. Calculated criticalities at every temperature are under sub-criticalities and criticalities of canister and DBD system considering temperature are expected to become 0.34932 and 0.37618 approximately. There are obvious limitations in this study. To obtain reliable data, exact elementary composition of each component, system component temperature must be specified and applied, and then proper cross section according to each component temperature must be adopted. However, many assumptions, for example simplified elementary concentration and isothermal component temperature, are adopted in this study. Improvement of these data must be conducted in the future work to progress reliability. And, post closure criticality analyses including geo, thermal, hydro, mechanical, chemical mechanism, especially fissile material re-deposition by precipitation and sorption, must be considered to ascertain criticality safety of DBD system as a future work
Preliminary shielding calculation for the system of CyberKnife robotic radiosurgery
International Nuclear Information System (INIS)
Toreti, Dalila; Xavier, Clarice; Moura, Fabio
2011-01-01
The CyberKnife robotic system uses a manipulator with six grade of freedom for positioning a 6 MV Linac accelerator for treatment of lesions. This paper presents calculations for a standard room, with 200 cm of thickness walls primary, build for a CyberKnife system, and calculations for a room originally designed for a Linac conventional (with gantry), with secondary barriers of 107 cm thickness. After the realization of shielding for both rooms, the results shown that walls of standard room with 200 cm thickness are adequate for the secondary shield, and for a room with a conventional Linac, from all six evaluated points, two would require additional shielding of nine cm and four cm of concrete with 2.4 g/cubic cm. This shows that the CyberKnife system can be installed in a originally designed room for a conventional Linac with neither restrict nor any shielding, since no incidence of beams on the secondary barriers is existent
Preliminary reactor physics calculations for Exxon LWR fuel testing in the power burst facility
International Nuclear Information System (INIS)
Olson, W.O.; Nigg, D.W.
1981-05-01
The PFB reactor is being considered as an irradiation facility to test LWR fuel rods for Exxon Nuclear Company. Requested test conditions are 18 kW/ft axial peak steady state power in 2.5% initial enrichment, 20,000 MWd/Tu exposed rods. Multigroup transport theory calculations (S/sub n/ and Monte Carlo) showed that this was unattainable in the standard PBF test loop. Thus, a flux multiplier was developed in the form of a Zr-2-clad 0.15-inch thick cylindrical shell of 35% enriched, 88% T.D. UO 2 replacing the flow divider, surrounding the rod within the in-pile tube in PFB. With this flux multiplier installed and assuming an average water density of 0.86 g/cm 3 within the test loop, a Figure of Merit (FOM) for a single-rod test assembly of 0.86 kW/ft-MW +- 5% (at 95% confidence level) was calculated. This FOM is the axial peak linear test rod power per megawatt of reactor power. A reactor power of about 21 megawatts will therefore be required to supply the requested linear test rod axial peak heating rate of 18 kW/ft
Microbial Communities Model Parameter Calculation for TSPA/SR
International Nuclear Information System (INIS)
D. Jolley
2001-01-01
This calculation has several purposes. First the calculation reduces the information contained in ''Committed Materials in Repository Drifts'' (BSC 2001a) to useable parameters required as input to MING V1.O (CRWMS M and O 1998, CSCI 30018 V1.O) for calculation of the effects of potential in-drift microbial communities as part of the microbial communities model. The calculation is intended to replace the parameters found in Attachment II of the current In-Drift Microbial Communities Model revision (CRWMS M and O 2000c) with the exception of Section 11-5.3. Second, this calculation provides the information necessary to supercede the following DTN: M09909SPAMING1.003 and replace it with a new qualified dataset (see Table 6.2-1). The purpose of this calculation is to create the revised qualified parameter input for MING that will allow ΔG (Gibbs Free Energy) to be corrected for long-term changes to the temperature of the near-field environment. Calculated herein are the quadratic or second order regression relationships that are used in the energy limiting calculations to potential growth of microbial communities in the in-drift geochemical environment. Third, the calculation performs an impact review of a new DTN: M00012MAJIONIS.000 that is intended to replace the currently cited DTN: GS9809083 12322.008 for water chemistry data used in the current ''In-Drift Microbial Communities Model'' revision (CRWMS M and O 2000c). Finally, the calculation updates the material lifetimes reported on Table 32 in section 6.5.2.3 of the ''In-Drift Microbial Communities'' AMR (CRWMS M and O 2000c) based on the inputs reported in BSC (2001a). Changes include adding new specified materials and updating old materials information that has changed
A model to calculate the burn of gadolinium in PWR
International Nuclear Information System (INIS)
Sannazzaro, L.R.
1983-01-01
A cell model to calculate the burnup of a PWR fuel element with gadolinium as a poison, projected by KWU, is presented. With the model proposed, the burn of the gadolinium isotopes is analyzed, as well as the effect of these isotopes in the fuel element behaviour. The results obtained with this cell model are compared with those obtained by a conventional cell model. (E.G.) [pt
Methodology and preliminary models for analyzing nuclear safeguards decisions
International Nuclear Information System (INIS)
1978-11-01
This report describes a general analytical tool designed to assist the NRC in making nuclear safeguards decisions. The approach is based on decision analysis--a quantitative procedure for making decisions under uncertain conditions. The report: describes illustrative models that quantify the probability and consequences of diverted special nuclear material and the costs of safeguarding the material, demonstrates a methodology for using this information to set safeguards regulations (safeguards criteria), and summarizes insights gained in a very preliminary assessment of a hypothetical reprocessing plant
Methodology and preliminary models for analyzing nuclear-safeguards decisions
International Nuclear Information System (INIS)
Judd, B.R.; Weissenberger, S.
1978-11-01
This report describes a general analytical tool designed with Lawrence Livermore Laboratory to assist the Nuclear Regulatory Commission in making nuclear safeguards decisions. The approach is based on decision analysis - a quantitative procedure for making decisions under uncertain conditions. The report: describes illustrative models that quantify the probability and consequences of diverted special nuclear material and the costs of safeguarding the material; demonstrates a methodology for using this information to set safeguards regulations (safeguards criteria); and summarizes insights gained in a very preliminary assessment of a hypothetical reprocessing plant
Preliminary Calculation of the EROI for the Production of Gas in Russia
Directory of Open Access Journals (Sweden)
Roman Nogovitsyn
2014-09-01
Full Text Available Russia is one of the world’s largest producers of energy resources. Production of energy resources in Russia is profitable, both economically and in terms of the energy produced (as measured by EROI. At the present time, Russian oil and gas companies have a policy of energy saving, and data on energy consumption is given in annual reports. Based on these data, we can make the EROI calculation. In 2013, the EROI for the production, transportation and processing of gas for Open joint stock company (OJSC “Gazprom” was 79:1; for OJSC “NOVATEK”, 76:1; for OJSC “Yakutsk Fuel and Energy Company (YATEC”, only for production, 116:1. Currently, the situation in the oil and gas industry has come to a point when there is a need for the introduction of an energy audit.
batman: BAsic Transit Model cAlculatioN in Python
Kreidberg, Laura
2015-11-01
I introduce batman, a Python package for modeling exoplanet transit light curves. The batman package supports calculation of light curves for any radially symmetric stellar limb darkening law, using a new integration algorithm for models that cannot be quickly calculated analytically. The code uses C extension modules to speed up model calculation and is parallelized with OpenMP. For a typical light curve with 100 data points in transit, batman can calculate one million quadratic limb-darkened models in 30 seconds with a single 1.7 GHz Intel Core i5 processor. The same calculation takes seven minutes using the four-parameter nonlinear limb darkening model (computed to 1 ppm accuracy). Maximum truncation error for integrated models is an input parameter that can be set as low as 0.001 ppm, ensuring that the community is prepared for the precise transit light curves we anticipate measuring with upcoming facilities. The batman package is open source and publicly available at https://github.com/lkreidberg/batman .
Statistical Model Calculations for (n,γ Reactions
Directory of Open Access Journals (Sweden)
Beard Mary
2015-01-01
Full Text Available Hauser-Feshbach (HF cross sections are of enormous importance for a wide range of applications, from waste transmutation and nuclear technologies, to medical applications, and nuclear astrophysics. It is a well-observed result that diﬀerent nuclear input models sensitively aﬀect HF cross section calculations. Less well known however are the eﬀects on calculations originating from model-specific implementation details (such as level density parameter, matching energy, back-shift and giant dipole parameters, as well as eﬀects from non-model aspects, such as experimental data truncation and transmission function energy binning. To investigate the eﬀects or these various aspects, Maxwellian-averaged neutron capture cross sections have been calculated for approximately 340 nuclei. The relative eﬀects of these model details will be discussed.
Modelling lung cancer due to radon and smoking in WISMUT miners: Preliminary results
International Nuclear Information System (INIS)
Bijwaard, H.; Dekkers, F.; Van Dillen, T.
2011-01-01
A mechanistic two-stage carcinogenesis model has been applied to model lung-cancer mortality in the largest uranium-miner cohort available. Models with and without smoking action both fit the data well. As smoking information is largely missing from the cohort data, a method has been devised to project this information from a case-control study onto the cohort. Model calculations using 256 projections show that the method works well. Preliminary results show that if an explicit smoking action is absent in the model, this is compensated by the values of the baseline parameters. This indicates that in earlier studies performed without smoking information, the results obtained for the radiation parameters are still valid. More importantly, the inclusion of smoking-related parameters shows that these mainly influence the later stages of lung-cancer development. (authors)
Interacting boson model: Microscopic calculations for the mercury isotopes
Energy Technology Data Exchange (ETDEWEB)
Druce, C.H.; Pittel, S.; Barrett, B.R.; Duval, P.D.
1987-05-15
Microscopic calculations of the parameters of the proton--neutron interacting boson model (IBM-2) appropriate to the even Hg isotopes are reported. The calculations are based on the Otsuka--Arima--Iachello boson mapping procedure, which is briefly reviewed. Renormalization of the parameters due to exclusion of the l = 4 g boson is treated perturbatively. The calculations employ a semi-realistic shell-model Hamiltonian with no adjustable parameters. The calculated parameters of the IBM-2 Hamiltonian are used to generate energy spectra and electromagnetic transition probabilities, which are compared with experimental data and with the result of phenomenological fits. The overall agreement is reasonable with some notable exceptions, which are discussed. Particular attention is focused on the parameters of the Majorana interaction and on the F-spin character of low-lying levels. copyright 1987 Academic Press, Inc.
The interacting boson model: Microscopic calculations for the mercury isotopes
Druce, C. H.; Pittel, S.; Barrett, B. R.; Duval, P. D.
1987-05-01
Microscopic calculations of the parameters of the proton-neutron interacting boson model (IBM-2) appropriate to the even Hg isotopes are reported. The calculations are based on the Otsuka-Armia-Iachello boson mapping procedure, which is briefly reviewed. Renormalization of the parameters due to exclusion of the l=4 g boson is treated perturbatively. The calculations employ a semi-realistic shell-model Hamiltonian with no adjustable parameters. The calculated parameters of the IBM-2 Hamiltonian are used to generate energy spectra and electromagnetic transition probabilities, which are compared with experimental data and with the result of phenomenological fits. The overall agreement is reasonable with some notable exceptions, which are discussed. Particular attention is focused on the parameters of the Majorana interaction and on the F-spin character of low-lying levels.
Optimal Height Calculation and Modelling of Noise Barrier
Directory of Open Access Journals (Sweden)
Raimondas Grubliauskas
2011-04-01
Full Text Available Transport is one of the main sources of noise having a particularly strong negative impact on the environment. In the city, one of the best methods to reduce the spread of noise in residential areas is a noise barrier. The article presents noise reduction barrier adaptation with empirical formulas calculating and modelling noise distribution. The simulation of noise dispersion has been performed applying the CadnaA program that allows modelling the noise levels of various developments under changing conditions. Calculation and simulation is obtained by assessing the level of noise reduction using the same variables. The investigation results are presented as noise distribution isolines. The selection of a different height of noise barriers are the results calculated at the heights of 1, 4 and 15 meters. The level of noise reduction at the maximum overlap of data, calculation and simulation has reached about 10%.Article in Lithuanian
A preliminary model to identify low-risk MBA applicants
Directory of Open Access Journals (Sweden)
CA Bisschoff
2014-08-01
The reliability of the discriminant function rates favourably with 71% (MBA in 3 years, 62% (MBA in 4 years and 83% (dropping out of the programme being categorised correctly by the respective discriminant functions. Being a preliminary model, its predictive capabilities need to be verified in practice before it can be implemented as tool to render assistance in MBA admissions. The value of this research lies in the fact that it constitutes a model that could be employed and improved as a predictive tool in an environment where very limited predictive tools exist. Therefore, although it is by no means a tried and tested model, it sets the scene by supplying a scientific base from which incremental improvements could result.
International Nuclear Information System (INIS)
Akmansu, M.; Dirican, Bahar; Oeztuerk, Berrin; Egehan, Ibrahim; Subasi, Mahmut; Or, Meral
1998-01-01
Purpose: This study was performed to determine the toxicity and efficacy of external-beam radiotherapy in patients with age-related subfoveal neovascularization. Methods and Materials: Between January 1996 and September 1996, 25 patients with a mean age of 70.5 (60-84) years were enrolled. All patients underwent fluorescein angiographic evaluation and documentation of their neovascular disease prior to irradiation. A total of 25 patients were treated with a total dose of 12 Gy in 6 fractions over 8 days. We used a lens-sparing technique and patients were treated with a single lateral 6-MV photon beam. To assess the risk of radiation carcinogenesis after treatment of age-related subfoveal neovascularization, we estimated the effective dose for a standard patient on the basis of tissue-weighting factors as defined by the International Commission on Radiological Protection (ICRP). The calculations were made with TLD on a male randophantom. The lens dose was found to be 0.217 Gy per fraction. Results: No significant acute morbidity was noted. Visual acuity was maintained or improved in 76% and 80% of treated patients at their 1- and 3-month follow-up examinations, respectively. On angiographic imaging, there was stabilization of subfoveal neovascular membranes in 23 patients (92%) at 3 months after irradiation. Conclusion: Our observations on these 25 patients in this study indicate that many patients will have improved or stable vision after radiotherapy treatment with low-dose irradiation
Recoil corrected bag model calculations for semileptonic weak decays
International Nuclear Information System (INIS)
Lie-Svendsen, Oe.; Hoegaasen, H.
1987-02-01
Recoil corrections to various model results for strangeness changing weak decay amplitudes have been developed. It is shown that the spurious reference frame dependence of earlier calculations is reduced. The second class currents are generally less important than obtained by calculations in the static approximation. Theoretical results are compared to observations. The agreement is quite good, although the values for the Cabibbo angle obtained by fits to the decay rates are somewhat to large
Optical model calculations with the code ECIS95
Energy Technology Data Exchange (ETDEWEB)
Carlson, B V [Departamento de Fisica, Instituto Tecnologico da Aeronautica, Centro Tecnico Aeroespacial (Brazil)
2001-12-15
The basic features of elastic and inelastic scattering within the framework of the spherical and deformed nuclear optical models are discussed. The calculation of cross sections, angular distributions and other scattering quantities using J. Raynal's code ECIS95 is described. The use of the ECIS method (Equations Couplees en Iterations Sequentielles) in coupled-channels and distorted-wave Born approximation calculations is also reviewed. (author)
Use of nuclear reaction models in cross section calculations
International Nuclear Information System (INIS)
Grimes, S.M.
1975-03-01
The design of fusion reactors will require information about a large number of neutron cross sections in the MeV region. Because of the obvious experimental difficulties, it is probable that not all of the cross sections of interest will be measured. Current direct and pre-equilibrium models can be used to calculate non-statistical contributions to neutron cross sections from information available from charged particle reaction studies; these are added to the calculated statistical contribution. Estimates of the reliability of such calculations can be derived from comparisons with the available data. (3 tables, 12 figures) (U.S.)
Realistic shell-model calculations for Sn isotopes
International Nuclear Information System (INIS)
Covello, A.; Andreozzi, F.; Coraggio, L.; Gargano, A.; Porrino, A.
1997-01-01
We report on a shell-model study of the Sn isotopes in which a realistic effective interaction derived from the Paris free nucleon-nucleon potential is employed. The calculations are performed within the framework of the seniority scheme by making use of the chain-calculation method. This provides practically exact solutions while cutting down the amount of computational work required by a standard seniority-truncated calculation. The behavior of the energy of several low-lying states in the isotopes with A ranging from 122 to 130 is presented and compared with the experimental one. (orig.)
Proposal of a calculation methodology for the preliminary design of a coalescing filter
International Nuclear Information System (INIS)
Gonzalez Dobrosky, Cintia
2015-01-01
Coalescing filters are described which are equipments for capture and recovery of mist most efficient, inexpensive and have fewer limitations of application. The operation, equations and ideal characteristics of filter media of these models are explained. A methodology for design and scale-up of this type of equipment for liquid recovery in gaseous currents is proposed from experimental tests, in order to guide the interested reader in its making. (author) [es
Approximate dynamic fault tree calculations for modelling water supply risks
International Nuclear Information System (INIS)
Lindhe, Andreas; Norberg, Tommy; Rosén, Lars
2012-01-01
Traditional fault tree analysis is not always sufficient when analysing complex systems. To overcome the limitations dynamic fault tree (DFT) analysis is suggested in the literature as well as different approaches for how to solve DFTs. For added value in fault tree analysis, approximate DFT calculations based on a Markovian approach are presented and evaluated here. The approximate DFT calculations are performed using standard Monte Carlo simulations and do not require simulations of the full Markov models, which simplifies model building and in particular calculations. It is shown how to extend the calculations of the traditional OR- and AND-gates, so that information is available on the failure probability, the failure rate and the mean downtime at all levels in the fault tree. Two additional logic gates are presented that make it possible to model a system's ability to compensate for failures. This work was initiated to enable correct analyses of water supply risks. Drinking water systems are typically complex with an inherent ability to compensate for failures that is not easily modelled using traditional logic gates. The approximate DFT calculations are compared to results from simulations of the corresponding Markov models for three water supply examples. For the traditional OR- and AND-gates, and one gate modelling compensation, the errors in the results are small. For the other gate modelling compensation, the error increases with the number of compensating components. The errors are, however, in most cases acceptable with respect to uncertainties in input data. The approximate DFT calculations improve the capabilities of fault tree analysis of drinking water systems since they provide additional and important information and are simple and practically applicable.
Comparison of the performance of net radiation calculation models
DEFF Research Database (Denmark)
Kjærsgaard, Jeppe Hvelplund; Cuenca, R.H.; Martinez-Cob, A.
2009-01-01
. The long-wave radiation models included a physically based model, an empirical model from the literature, and a new empirical model. Both empirical models used only solar radiation as required for meteorological input. The long-wave radiation models were used with model calibration coefficients from......Daily values of net radiation are used in many applications of crop-growth modeling and agricultural water management. Measurements of net radiation are not part of the routine measurement program at many weather stations and are commonly estimated based on other meteorological parameters. Daily...... values of net radiation were calculated using three net outgoing long-wave radiation models and compared to measured values. Four meteorological datasets representing two climate regimes, a sub-humid, high-latitude environment and a semi-arid mid-latitude environment, were used to test the models...
A Generative Computer Model for Preliminary Design of Mass Housing
Directory of Open Access Journals (Sweden)
Ahmet Emre DİNÇER
2014-05-01
Full Text Available Today, we live in what we call the “Information Age”, an age in which information technologies are constantly being renewed and developed. Out of this has emerged a new approach called “Computational Design” or “Digital Design”. In addition to significantly influencing all fields of engineering, this approach has come to play a similar role in all stages of the design process in the architectural field. In providing solutions for analytical problems in design such as cost estimate, circulation systems evaluation and environmental effects, which are similar to engineering problems, this approach is being used in the evaluation, representation and presentation of traditionally designed buildings. With developments in software and hardware technology, it has evolved as the studies based on design of architectural products and production implementations with digital tools used for preliminary design stages. This paper presents a digital model which may be used in the preliminary stage of mass housing design with Cellular Automata, one of generative design systems based on computational design approaches. This computational model, developed by scripts of 3Ds Max software, has been implemented on a site plan design of mass housing, floor plan organizations made by user preferences and facade designs. By using the developed computer model, many alternative housing types could be rapidly produced. The interactive design tool of this computational model allows the user to transfer dimensional and functional housing preferences by means of the interface prepared for model. The results of the study are discussed in the light of innovative architectural approaches.
EMPIRE-II statistical model code for nuclear reaction calculations
Energy Technology Data Exchange (ETDEWEB)
Herman, M [International Atomic Energy Agency, Vienna (Austria)
2001-12-15
EMPIRE II is a nuclear reaction code, comprising various nuclear models, and designed for calculations in the broad range of energies and incident particles. A projectile can be any nucleon or Heavy Ion. The energy range starts just above the resonance region, in the case of neutron projectile, and extends up to few hundreds of MeV for Heavy Ion induced reactions. The code accounts for the major nuclear reaction mechanisms, such as optical model (SCATB), Multistep Direct (ORION + TRISTAN), NVWY Multistep Compound, and the full featured Hauser-Feshbach model. Heavy Ion fusion cross section can be calculated within the simplified coupled channels approach (CCFUS). A comprehensive library of input parameters covers nuclear masses, optical model parameters, ground state deformations, discrete levels and decay schemes, level densities, fission barriers (BARFIT), moments of inertia (MOMFIT), and {gamma}-ray strength functions. Effects of the dynamic deformation of a fast rotating nucleus can be taken into account in the calculations. The results can be converted into the ENDF-VI format using the accompanying code EMPEND. The package contains the full EXFOR library of experimental data. Relevant EXFOR entries are automatically retrieved during the calculations. Plots comparing experimental results with the calculated ones can be produced using X4TOC4 and PLOTC4 codes linked to the rest of the system through bash-shell (UNIX) scripts. The graphic user interface written in Tcl/Tk is provided. (author)
Precipitates/Salts Model Calculations for Various Drift Temperature Environments
Energy Technology Data Exchange (ETDEWEB)
P. Marnier
2001-12-20
The objective and scope of this calculation is to assist Performance Assessment Operations and the Engineered Barrier System (EBS) Department in modeling the geochemical effects of evaporation within a repository drift. This work is developed and documented using procedure AP-3.12Q, Calculations, in support of ''Technical Work Plan For Engineered Barrier System Department Modeling and Testing FY 02 Work Activities'' (BSC 2001a). The primary objective of this calculation is to predict the effects of evaporation on the abstracted water compositions established in ''EBS Incoming Water and Gas Composition Abstraction Calculations for Different Drift Temperature Environments'' (BSC 2001c). A secondary objective is to predict evaporation effects on observed Yucca Mountain waters for subsequent cement interaction calculations (BSC 2001d). The Precipitates/Salts model is documented in an Analysis/Model Report (AMR), ''In-Drift Precipitates/Salts Analysis'' (BSC 2001b).
The models of internal dose calculation in ICRP
International Nuclear Information System (INIS)
Nakano, Takashi
1995-01-01
There are a lot discussions about internal dose calculation in ICRP. Many efforts are devoted to improvement in models and parameters. In this report, we discuss what kind of models and parameters are used in ICRP. Models are divided into two parts, the dosimetric model and biokinetic model. The former is a mathematical phantom model, and it is mainly developed in ORNL. The results are used in many researchers. The latter is a compartment model and it has a difficulty to decide the parameter values. They are not easy to estimate because of their age dependency. ICRP officially sets values at ages of 3 month, 1 year, 5 year, 10 year, 15 year and adult, and recommends to get values among ages by linear age interpolate. But it is very difficult to solve the basic equation with these values, so we calculate by use of computers. However, it has complex shame and needs long CPU time. We should make approximated equations. The parameter values include much uncertainty because of less experimental data, especially for a child. And these models and parameter values are for Caucasian. We should inquire whether they could correctly describe other than Caucasian. The body size affects the values of calculated SAF, and the differences of metabolism change the biokinetic pattern. (author)
Interactions of model biomolecules. Benchmark CC calculations within MOLCAS
Energy Technology Data Exchange (ETDEWEB)
Urban, Miroslav [Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917 24 Trnava, Slovakia and Department of Physical and Theoretical Chemistry, Faculty of Natural Scie (Slovakia); Pitoňák, Michal; Neogrády, Pavel; Dedíková, Pavlína [Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava (Slovakia); Hobza, Pavel [Institute of Organic Chemistry and Biochemistry and Center for Complex Molecular Systems and biomolecules, Academy of Sciences of the Czech Republic, Prague (Czech Republic)
2015-01-22
We present results using the OVOS approach (Optimized Virtual Orbitals Space) aimed at enhancing the effectiveness of the Coupled Cluster calculations. This approach allows to reduce the total computer time required for large-scale CCSD(T) calculations about ten times when the original full virtual space is reduced to about 50% of its original size without affecting the accuracy. The method is implemented in the MOLCAS computer program. When combined with the Cholesky decomposition of the two-electron integrals and suitable parallelization it allows calculations which were formerly prohibitively too demanding. We focused ourselves to accurate calculations of the hydrogen bonded and the stacking interactions of the model biomolecules. Interaction energies of the formaldehyde, formamide, benzene, and uracil dimers and the three-body contributions in the cytosine – guanine tetramer are presented. Other applications, as the electron affinity of the uracil affected by solvation are also shortly mentioned.
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-09-15
The European Commission decided in 2001 an analysis program to reduce the atmospheric emissions. This report presents different limit scenari for France in 2020 (the reference scenari and the MTFR scenari, Maximum Technically Feasible Reduction), optimized scenari calculated by the RAINS model (Regional Air Pollution Information and Simulation), the costs of the scenari calculated with RAINS and the cost-benefit analysis of the strategy CAFE. From the study results, the benefits are higher than the costs, even with the most ambitious scenari. At an european level the emission reduction strategies have no effect on the employment but an impact on the Gross Domestic Product (decrease between 0,04 % and 0,12 % in function of the scenari). (A.L.B.)
Laminated materials with plastic interfaces: modeling and calculation
International Nuclear Information System (INIS)
Sandino Aquino de los Ríos, Gilberto; Castañeda Balderas, Rubén; Diaz Diaz, Alberto; Duong, Van Anh; Chataigner, Sylvain; Caron, Jean-François; Ehrlacher, Alain; Foret, Gilles
2009-01-01
In this paper, a model of laminated plates called M4-5N and validated in a previous paper is modified in order to take into account interlaminar plasticity by means of displacement discontinuities at the interfaces. These discontinuities are calculated by adapting a 3D plasticity model. In order to compute the model, a Newton–Raphson-like method is employed. In this method, two sub-problems are considered: one is linear and the other is non-linear. In the linear problem the non-linear equations of the model are linearized and the calculations are performed by making use of a finite element software. By iterating the resolution of each sub-problem, one obtains after convergence the solution of the global problem. The model is then applied to the problem of a double lap, adhesively bonded joint subjected to a tensile load. The adhesive layer is modeled by an elastic–plastic interface. The results of the M4-5N model are compared with those of a commercial finite element software. A good agreement between the two computation techniques is obtained and validates the non-linear calculations proposed in this paper. Finally, the numerical tool and a delamination criterion are applied to predict delamination onset in composite laminates
Use of results from microscopic methods in optical model calculations
International Nuclear Information System (INIS)
Lagrange, C.
1985-11-01
A concept of vectorization for coupled-channel programs based upon conventional methods is first presented. This has been implanted in our program for its use on the CRAY-1 computer. In a second part we investigate the capabilities of a semi-microscopic optical model involving fewer adjustable parameters than phenomenological ones. The two main ingredients of our calculations are, for spherical or well-deformed nuclei, the microscopic optical-model calculations of Jeukenne, Lejeune and Mahaux and nuclear densities from Hartree-Fock-Bogoliubov calculations using the density-dependent force D1. For transitional nuclei deformation-dependent nuclear structure wave functions are employed to weigh the scattering potentials for different shapes and channels [fr
Precision calculations in supersymmetric extensions of the Standard Model
International Nuclear Information System (INIS)
Slavich, P.
2013-01-01
This dissertation is organized as follows: in the next chapter I will summarize the structure of the supersymmetric extensions of the standard model (SM), namely the MSSM (Minimal Supersymmetric Standard Model) and the NMSSM (Next-to-Minimal Supersymmetric Standard Model), I will provide a brief overview of different patterns of SUSY (supersymmetry) breaking and discuss some issues on the renormalization of the input parameters that are common to all calculations of higher-order corrections in SUSY models. In chapter 3 I will review and describe computations on the production of MSSM Higgs bosons in gluon fusion. In chapter 4 I will review results on the radiative corrections to the Higgs boson masses in the NMSSM. In chapter 5 I will review the calculation of BR(B → X s γ in the MSSM with Minimal Flavor Violation (MFV). Finally, in chapter 6 I will briefly summarize the outlook of my future research. (author)
Do calculated conflicts in microsimulation model predict number of crashes?
Dijkstra, Atze; Marchesini, Paula; Bijleveld, Frits; Kars, Vincent; Drolenga, Hans; Maarseveen, Martin Van
2010-01-01
A microsimulation model and its calculations are described, and the results that are subsequently used to determine indicators for traffic safety are presented. The method demonstrates which changes occur at the level of traffic flow (number of vehicles per section of road) and at the vehicle level
A shell-model calculation in terms of correlated subsystems
International Nuclear Information System (INIS)
Boisson, J.P.; Silvestre-Brac, B.
1979-01-01
A method for solving the shell-model equations in terms of a basis which includes correlated subsystems is presented. It is shown that the method allows drastic truncations of the basis to be made. The corresponding calculations are easy to perform and can be carried out rapidly
TTS-Polttopuu - cost calculation model for fuelwood
International Nuclear Information System (INIS)
Naett, H.; Ryynaenen, S.
1999-01-01
The TTS-Institutes's Forestry Department has developed a computer based cost-calculation model, 'TTS-Polttopuu', for the calculation of unit costs and resource needs in the harvesting systems for wood chips and split firewood. The model enables to determine the productivity and device cost per operating hour by each working stage of the harvesting system. The calculation model also enables the user to find out how changes in the productivity and cost bases of different harvesting chains influence the unit cost of the whole system. The harvesting chain includes the cutting of delimbed and non-delimbed fuelwood, forest haulage, road transportation, chipping and chopping of longwood at storage. This individually operating software was originally developed to serve research needs, but it also serves the needs of the forestry and agricultural education, training and extension as well as individual firewood producers. The system requirements for this cost calculation model are at least 486- level processor with the Windows 95/98 -operating system, 16 MB of memory (RAM) and 5 MB of available hard-disk. This development work was carried out in conjunction with the nation-wide BIOENERGY-research programme. (orig.)
Calculation of extreme wind atlases using mesoscale modeling. Final report
DEFF Research Database (Denmark)
Larsén, Xiaoli Guo; Badger, Jake
This is the final report of the project PSO-10240 "Calculation of extreme wind atlases using mesoscale modeling". The overall objective is to improve the estimation of extreme winds by developing and applying new methodologies to confront the many weaknesses in the current methodologies as explai...
Overview of models allowing calculation of activity coefficients
Energy Technology Data Exchange (ETDEWEB)
Jaussaud, C.; Sorel, C
2004-07-01
Activity coefficients must be estimated to accurately quantify the extraction equilibrium involved in spent fuel reprocessing. For these calculations, binary data are required for each electrolyte over a concentration range sometimes exceeding the maximum solubility. The activity coefficients must be extrapolated to model the behavior of binary supersaturated aqueous solution. According to the bibliography, the most suitable models are based on the local composition concept. (authors)
Utility of Social Modeling for Proliferation Assessment - Preliminary Findings
International Nuclear Information System (INIS)
Coles, Garill A.; Gastelum, Zoe N.; Brothers, Alan J.; Thompson, Sandra E.
2009-01-01
Often the methodologies for assessing proliferation risk are focused around the inherent vulnerability of nuclear energy systems and associated safeguards. For example an accepted approach involves ways to measure the intrinsic and extrinsic barriers to potential proliferation. This paper describes preliminary investigation into non-traditional use of social and cultural information to improve proliferation assessment and advance the approach to assessing nuclear material diversion. Proliferation resistance assessment, safeguard assessments and related studies typically create technical information about the vulnerability of a nuclear energy system to diversion of nuclear material. The purpose of this research project is to find ways to integrate social information with technical information by explicitly considering the role of culture, groups and/or individuals to factors that impact the possibility of proliferation. When final, this work is expected to describe and demonstrate the utility of social science modeling in proliferation and proliferation risk assessments.
Shell model calculations for stoichiometric Na β-alumina
International Nuclear Information System (INIS)
Wang, J.C.
1985-01-01
Walker and Catlow recently reported the results of their shell model calculations for the structure and transport of Na β-alumina (Naβ). The main computer programs used by Walker and Catlow for their calculations are PLUTO and HADES III. The latter, a recent version of HADES II written for cubic crystals, is believed to be applicable to defects in crystals of both cubic and hexagonal symmetry. PLUTO is usually used in calculating properties of perfect crystals before defects are introduced into the structure. Walker and Catlow claim that, in some respects, their models are superior to those of Wang et al. Yet, their results are quite different from those observed experimentally. In this work these differences are investigated by using a computer program designed to calculate lattice energies for s Naβ using the same shell model parameters adopted by Walker and Catlow. The core and shell positions of all ions, as well as the lattice parameters, were fully relaxed. The calculated energy difference between aBR and BR sites (0.33 eV) is about twice as large as that reported by Walker and Catlow. The present results also show that the relaxed oxygen ion positions next to the conduction plane in this case are displaced from their observed sites reported. When the core-shell spring constant of the oxygen ion was adjusted to minimize these displacements, the above-mentioned energy difference increased to about 0.56 eV. These results cast doubt on the fluid conduction plane structure suggested by Walker and Catlow and on the defect structure and activation energy obtained from their calculations
Cluster model calculations of alpha decays across the periodic table
International Nuclear Information System (INIS)
Merchant, A.C.; Buck, B.
1988-10-01
The cluster model of Buck, Dover and Vary has been used to calculate partial widths for alpha decay from the ground states of all nuclei for which experimental measurements exist. The cluster-core potential is represented by a simple three-parameter form having fixed diffuseness, a radius which scales as A 1/3 and a depth which is adjusted to fit the Q-value of the particular decay. The calculations yield excellent agreement with the vast majority of the available data, and some typical examples are presented. (author) [pt
Modelling of Control Bars in Calculations of Boiling Water Reactors
International Nuclear Information System (INIS)
Khlaifi, A.; Buiron, L.
2004-01-01
The core of a nuclear reactor is generally composed of a neat assemblies of fissile material from where neutrons were descended. In general, the energy of fission is extracted by a fluid serving to cool clusters. A reflector is arranged around the assemblies to reduce escaping of neutrons. This is made outside the reactor core. Different mechanisms of reactivity are generally necessary to control the chain reaction. Manoeuvring of Boiling Water Reactor takes place by controlling insertion of absorbent rods to various places of the core. If no blocked assembly calculations are known and mastered, blocked assembly neutronic calculation are delicate and often treated by case to case in present studies [1]. Answering the question how to model crossbar for the control of a boiling water reactor ? requires the choice of a representation level for every chain of variables, the physical model, and its representing equations, etc. The aim of this study is to select the best applicable parameter serving to calculate blocked assembly of a Boiling Water Reactor. This will be made through a range of representative configurations of these reactors and used absorbing environment, in order to illustrate strategies of modelling in the case of an industrial calculation. (authors)
Modelling and parallel calculation of a kinetic boundary layer
International Nuclear Information System (INIS)
Perlat, Jean Philippe
1998-01-01
This research thesis aims at addressing reliability and cost issues in the calculation by numeric simulation of flows in transition regime. The first step has been to reduce calculation cost and memory space for the Monte Carlo method which is known to provide performance and reliability for rarefied regimes. Vector and parallel computers allow this objective to be reached. Here, a MIMD (multiple instructions, multiple data) machine has been used which implements parallel calculation at different levels of parallelization. Parallelization procedures have been adapted, and results showed that parallelization by calculation domain decomposition was far more efficient. Due to reliability issue related to the statistic feature of Monte Carlo methods, a new deterministic model was necessary to simulate gas molecules in transition regime. New models and hyperbolic systems have therefore been studied. One is chosen which allows thermodynamic values (density, average velocity, temperature, deformation tensor, heat flow) present in Navier-Stokes equations to be determined, and the equations of evolution of thermodynamic values are described for the mono-atomic case. Numerical resolution of is reported. A kinetic scheme is developed which complies with the structure of all systems, and which naturally expresses boundary conditions. The validation of the obtained 14 moment-based model is performed on shock problems and on Couette flows [fr
Diffusion theory model for optimization calculations of cold neutron sources
International Nuclear Information System (INIS)
Azmy, Y.Y.
1987-01-01
Cold neutron sources are becoming increasingly important and common experimental facilities made available at many research reactors around the world due to the high utility of cold neutrons in scattering experiments. The authors describe a simple two-group diffusion model of an infinite slab LD 2 cold source. The simplicity of the model permits to obtain an analytical solution from which one can deduce the reason for the optimum thickness based solely on diffusion-type phenomena. Also, a second more sophisticated model is described and the results compared to a deterministic transport calculation. The good (particularly qualitative) agreement between the results suggests that diffusion theory methods can be used in parametric and optimization studies to avoid the generally more expensive transport calculations
Preliminary comparison of the system of AERMOD and ISCST3 models
International Nuclear Information System (INIS)
Turtos Carbonell, Leonor; Curbelo Garea, Lariza; Diaz Rivero, Norberto
2006-01-01
On October 21st, 2005 the U.S. Environmental Protection Agency (EPA), establishes AERMOD as regulatory model to be used for the dispersion of pollutants at local scale, in substitution of the ISCST3 model used up to that moment. Whenever a new dispersion model appears, it is necessary for the scientific community to make a comparison in order to discover the differences between the results obtained with the new model and the previous one. Considering the above mentioned fact, this work makes a preliminary comparison between the maximum concentrations calculated by each model (ISCST3 and AERMOD) for a specific case study that consists of eleven batteries of generation sets distributed throughout Havana City which will operate in base load mode and will use a fuel oil with 4% of sulphur. The modelling domain is the 50 xs 37 km with 1 x 1 km cells for a total of 1 850 calculation points (receptors), located in all Havana City and the bordering municipalities of Havana province. In each one of these receptors the dispersion of SO 2 and NO x were modelled
The 3D Reference Earth Model: Status and Preliminary Results
Moulik, P.; Lekic, V.; Romanowicz, B. A.
2017-12-01
In the 20th century, seismologists constructed models of how average physical properties (e.g. density, rigidity, compressibility, anisotropy) vary with depth in the Earth's interior. These one-dimensional (1D) reference Earth models (e.g. PREM) have proven indispensable in earthquake location, imaging of interior structure, understanding material properties under extreme conditions, and as a reference in other fields, such as particle physics and astronomy. Over the past three decades, new datasets motivated more sophisticated efforts that yielded models of how properties vary both laterally and with depth in the Earth's interior. Though these three-dimensional (3D) models exhibit compelling similarities at large scales, differences in the methodology, representation of structure, and dataset upon which they are based, have prevented the creation of 3D community reference models. As part of the REM-3D project, we are compiling and reconciling reference seismic datasets of body wave travel-time measurements, fundamental mode and overtone surface wave dispersion measurements, and normal mode frequencies and splitting functions. These reference datasets are being inverted for a long-wavelength, 3D reference Earth model that describes the robust long-wavelength features of mantle heterogeneity. As a community reference model with fully quantified uncertainties and tradeoffs and an associated publically available dataset, REM-3D will facilitate Earth imaging studies, earthquake characterization, inferences on temperature and composition in the deep interior, and be of improved utility to emerging scientific endeavors, such as neutrino geoscience. Here, we summarize progress made in the construction of the reference long period dataset and present a preliminary version of REM-3D in the upper-mantle. In order to determine the level of detail warranted for inclusion in REM-3D, we analyze the spectrum of discrepancies between models inverted with different subsets of the
Hybrid Reduced Order Modeling Algorithms for Reactor Physics Calculations
Bang, Youngsuk
Reduced order modeling (ROM) has been recognized as an indispensable approach when the engineering analysis requires many executions of high fidelity simulation codes. Examples of such engineering analyses in nuclear reactor core calculations, representing the focus of this dissertation, include the functionalization of the homogenized few-group cross-sections in terms of the various core conditions, e.g. burn-up, fuel enrichment, temperature, etc. This is done via assembly calculations which are executed many times to generate the required functionalization for use in the downstream core calculations. Other examples are sensitivity analysis used to determine important core attribute variations due to input parameter variations, and uncertainty quantification employed to estimate core attribute uncertainties originating from input parameter uncertainties. ROM constructs a surrogate model with quantifiable accuracy which can replace the original code for subsequent engineering analysis calculations. This is achieved by reducing the effective dimensionality of the input parameter, the state variable, or the output response spaces, by projection onto the so-called active subspaces. Confining the variations to the active subspace allows one to construct an ROM model of reduced complexity which can be solved more efficiently. This dissertation introduces a new algorithm to render reduction with the reduction errors bounded based on a user-defined error tolerance which represents the main challenge of existing ROM techniques. Bounding the error is the key to ensuring that the constructed ROM models are robust for all possible applications. Providing such error bounds represents one of the algorithmic contributions of this dissertation to the ROM state-of-the-art. Recognizing that ROM techniques have been developed to render reduction at different levels, e.g. the input parameter space, the state space, and the response space, this dissertation offers a set of novel
International Nuclear Information System (INIS)
Siefken, L.J.; Davis, K.L.
1993-02-01
Preliminary designs are proposed for extending the SCDAP/RELAP5 code so that it models (a) the oxidation of slumping fuel rod material and cohesive and porous debris and (b) the interaction of PWR control rod materials with the other materials in a reactor core. These extensions have the purpose of improving the code's calculation of the damage progression and hydrogen production that takes place during the early phase of a severe accident
TTS-Polttopuu - cost calculation model for fuelwood
International Nuclear Information System (INIS)
Naett, H.; Ryynaenen, S.
1998-01-01
The TTS-Institutes's Forestry Department has developed a computer based costcalculation model, 'TTS-Polttopuu', for the calculation of unit costs and resource needs in the harvesting systems for wood chips and split firewood. The model enables to determine the productivity and device cost per operating hour by each working stage of the harvesting system. The calculation model also enables the user to find out how changes in the productivity and cost bases of different harvesting chains influence the unit cost of the whole system. The harvesting chain includes the cutting of delimbed and non-delimbed fuelwood, forest haulage, road transportation chipping and chopping of longwood at storage. This individually operating software was originally developed to serve research needs, but it also serves the needs of the forestry and agricultural education, training and extension as well as individual firewood producers. The system requirements for this cost calculation model are at least 486-level processor with the Windows 95/98 -operating system, 16 MB of memory (RAM) and 5 MB of available hard-disk. This development work was carried out in conjunction with the nation-wide BIOENERGY Research Programme. (orig.)
Calculations of dose distributions using a neural network model
International Nuclear Information System (INIS)
Mathieu, R; Martin, E; Gschwind, R; Makovicka, L; Contassot-Vivier, S; Bahi, J
2005-01-01
The main goal of external beam radiotherapy is the treatment of tumours, while sparing, as much as possible, surrounding healthy tissues. In order to master and optimize the dose distribution within the patient, dosimetric planning has to be carried out. Thus, for determining the most accurate dose distribution during treatment planning, a compromise must be found between the precision and the speed of calculation. Current techniques, using analytic methods, models and databases, are rapid but lack precision. Enhanced precision can be achieved by using calculation codes based, for example, on Monte Carlo methods. However, in spite of all efforts to optimize speed (methods and computer improvements), Monte Carlo based methods remain painfully slow. A newer way to handle all of these problems is to use a new approach in dosimetric calculation by employing neural networks. Neural networks (Wu and Zhu 2000 Phys. Med. Biol. 45 913-22) provide the advantages of those various approaches while avoiding their main inconveniences, i.e., time-consumption calculations. This permits us to obtain quick and accurate results during clinical treatment planning. Currently, results obtained for a single depth-dose calculation using a Monte Carlo based code (such as BEAM (Rogers et al 2003 NRCC Report PIRS-0509(A) rev G)) require hours of computing. By contrast, the practical use of neural networks (Mathieu et al 2003 Proceedings Journees Scientifiques Francophones, SFRP) provides almost instant results and quite low errors (less than 2%) for a two-dimensional dosimetric map
Preliminary modelling of the 2010 MAM survey data
International Nuclear Information System (INIS)
Ahokas, T.
2010-10-01
Posiva Oy prepares for disposal of spent nuclear fuel into bedrock focusing in Olkiluoto, Eurajoki. This is in accordance of the Decision-in-Principle of the State Council in 2000, and ratification by the Parliament in 2001. The ONKALO underground characterization premises have been constructed since 2004. Posiva Oy is aiming for submitting the construction licence application in 2012. To support the compilation of the safety case and repository and ONKALO underground characterisation facility design and construction, a series of Olkiluoto Site Descriptive Model including six parts: the surface system geology, rock mechanics, hydrogeology and hydrogeochemistry and migration, have been compiled. To support the next update of the Olkiluoto Site Description and especially, the geological and hydrogeological sub-models, the preliminary modelling of the recent mise-a-la-masse (MAM) surveys has been carried out. This report discusses the mise-a-la-masse (MAM) surveys carried out in the Olkiluoto area in 2010 and aims to find out the continuation of some electrically conductive zones intersected by drillholes OL-KR49 ...OL-KR53 in the eastern part of the Olkiluoto island. Several electrically conductive zones were modelled from the examined data, many of them coincide with the brittle deformation zones presented in the geological model, but also indications of some so far unknown zones were detected. The complexity and the extent of the group of zones including the hydraulically conductive zones HZ19A, HZ19B and HZ19C (Vaittinen et al. 2009) emerged from the data during this work. Modelling of this group in detail needs more information from both geological and hydrogeological investigations. (orig.)
Model and calculation of in situ stresses in anisotropic formations
Energy Technology Data Exchange (ETDEWEB)
Yuezhi, W.; Zijun, L.; Lixin, H. [Jianghan Petroleum Institute, (China)
1997-08-01
In situ stresses in transversely isotropic material in relation to wellbore stability have been investigated. Equations for three horizontal in- situ stresses and a new formation fracture pressure model were described, and the methodology for determining the elastic parameters of anisotropic rocks in the laboratory was outlined. Results indicate significantly smaller differences between theoretically calculated pressures and actual formation pressures than results obtained by using the isotropic method. Implications for improvements in drilling efficiency were reviewed. 13 refs., 6 figs.
Perturbation theory instead of large scale shell model calculations
International Nuclear Information System (INIS)
Feldmeier, H.; Mankos, P.
1977-01-01
Results of large scale shell model calculations for (sd)-shell nuclei are compared with a perturbation theory provides an excellent approximation when the SU(3)-basis is used as a starting point. The results indicate that perturbation theory treatment in an SU(3)-basis including 2hω excitations should be preferable to a full diagonalization within the (sd)-shell. (orig.) [de
Calculation of relativistic model stars using Regge calculus
International Nuclear Information System (INIS)
Porter, J.
1987-01-01
A new approach to the Regge calculus, developed in a previous paper, is used in conjunction with the velocity potential version of relativistic fluid dynamics due to Schutz [1970, Phys. Rev., D, 2, 2762] to calculate relativistic model stars. The results are compared with those obtained when the Tolman-Oppenheimer-Volkov equations are solved by other numerical methods. The agreement is found to be excellent. (author)
Structure-dynamic model verification calculation of PWR 5 tests
International Nuclear Information System (INIS)
Engel, R.
1980-02-01
Within reactor safety research project RS 16 B of the German Federal Ministry of Research and Technology (BMFT), blowdown experiments are conducted at Battelle Institut e.V. Frankfurt/Main using a model reactor pressure vessel with a height of 11,2 m and internals corresponding to those in a PWR. In the present report the dynamic loading on the pressure vessel internals (upper perforated plate and barrel suspension) during the DWR 5 experiment are calculated by means of a vertical and horizontal dynamic model using the CESHOCK code. The equations of motion are resolved by direct integration. (orig./RW) [de
a Proposed Benchmark Problem for Scatter Calculations in Radiographic Modelling
Jaenisch, G.-R.; Bellon, C.; Schumm, A.; Tabary, J.; Duvauchelle, Ph.
2009-03-01
Code Validation is a permanent concern in computer modelling, and has been addressed repeatedly in eddy current and ultrasonic modeling. A good benchmark problem is sufficiently simple to be taken into account by various codes without strong requirements on geometry representation capabilities, focuses on few or even a single aspect of the problem at hand to facilitate interpretation and to avoid that compound errors compensate themselves, yields a quantitative result and is experimentally accessible. In this paper we attempt to address code validation for one aspect of radiographic modeling, the scattered radiation prediction. Many NDT applications can not neglect scattered radiation, and the scatter calculation thus is important to faithfully simulate the inspection situation. Our benchmark problem covers the wall thickness range of 10 to 50 mm for single wall inspections, with energies ranging from 100 to 500 keV in the first stage, and up to 1 MeV with wall thicknesses up to 70 mm in the extended stage. A simple plate geometry is sufficient for this purpose, and the scatter data is compared on a photon level, without a film model, which allows for comparisons with reference codes like MCNP. We compare results of three Monte Carlo codes (McRay, Sindbad and Moderato) as well as an analytical first order scattering code (VXI), and confront them to results obtained with MCNP. The comparison with an analytical scatter model provides insights into the application domain where this kind of approach can successfully replace Monte-Carlo calculations.
Ordinary Mathematical Models in Calculating the Aviation GTE Parameters
Directory of Open Access Journals (Sweden)
E. A. Khoreva
2017-01-01
Full Text Available The paper presents the analytical review results of the ordinary mathematical models of the operating process used to study aviation GTE parameters and characteristics at all stages of its creation and operation. Considers the mathematical models of the zero and the first level, which are mostly used when solving typical problems in calculating parameters and characteristics of engines.Presents a number of practical problems arising in designing aviation GTE for various applications.The application of mathematical models of the zero-level engine can be quite appropriate when the engine is considered as a component in the aircraft system to estimate its calculated individual flight performance or when modeling the flight cycle of the aircrafts of different purpose.The paper demonstrates that introduction of correction functions into the first-level mathematical models in solving typical problems (influence of the Reynolds number, characteristics deterioration of the units during the overhaul period of engine, as well as influence of the flow inhomogeneity at the inlet because of manufacturing tolerance, etc. enables providing a sufficient engineering estimate accuracy to reflect a realistic operating process in the engine and its elements.
Freeway travel speed calculation model based on ETC transaction data.
Weng, Jiancheng; Yuan, Rongliang; Wang, Ru; Wang, Chang
2014-01-01
Real-time traffic flow operation condition of freeway gradually becomes the critical information for the freeway users and managers. In fact, electronic toll collection (ETC) transaction data effectively records operational information of vehicles on freeway, which provides a new method to estimate the travel speed of freeway. First, the paper analyzed the structure of ETC transaction data and presented the data preprocess procedure. Then, a dual-level travel speed calculation model was established under different levels of sample sizes. In order to ensure a sufficient sample size, ETC data of different enter-leave toll plazas pairs which contain more than one road segment were used to calculate the travel speed of every road segment. The reduction coefficient α and reliable weight θ for sample vehicle speed were introduced in the model. Finally, the model was verified by the special designed field experiments which were conducted on several freeways in Beijing at different time periods. The experiments results demonstrated that the average relative error was about 6.5% which means that the freeway travel speed could be estimated by the proposed model accurately. The proposed model is helpful to promote the level of the freeway operation monitoring and the freeway management, as well as to provide useful information for the freeway travelers.
Preliminary report on NTS spectral gamma logging and calibration models
International Nuclear Information System (INIS)
Mathews, M.A.; Warren, R.G.; Garcia, S.R.; Lavelle, M.J.
1985-01-01
Facilities are now available at the Nevada Test Site (NTS) in Building 2201 to calibrate spectral gamma logging equipment in environments of low radioactivity. Such environments are routinely encountered during logging of holes at the NTS. Four calibration models were delivered to Building 2201 in January 1985. Each model, or test pit, consists of a stone block with a 12-inch diameter cored borehole. Preliminary radioelement values from the core for the test pits range from 0.58 to 3.83% potassium (K), 0.48 to 29.11 ppm thorium (Th), and 0.62 to 40.42 ppm uranium (U). Two satellite holes, U19ab number2 and U19ab number3, were logged during the winter of 1984-1985. The response of these logs correlates with contents of the naturally radioactive elements K. Th. and U determined in samples from petrologic zones that occur within these holes. Based on these comparisons, the spectral gamma log aids in the recognition and mapping of subsurface stratigraphic units and alteration features associated with unusual concentration of these radioactive elements, such as clay-rich zones
Mathematical model of kinetostatithic calculation of flat lever mechanisms
Directory of Open Access Journals (Sweden)
A. S. Sidorenko
2016-01-01
Full Text Available Currently widely used graphical-analytical methods of analysis largely obsolete, replaced by various analytical methods using computer technology. Therefore, of particular interest is the development of a mathematical model kinetostatical calculation mechanisms in the form of library procedures of calculation for all powered two groups Assyrians (GA and primary level. Before resorting to the appropriate procedure that computes all the forces in the kinematic pairs, you need to compute inertial forces, moments of forces of inertia and all external forces and moments acting on this GA. To this end shows the design diagram of the power analysis for each species GA of the second class, as well as the initial link. Finding reactions in the internal and external kinematic pairs based on equilibrium conditions with the account of forces of inertia and moments of inertia forces (Dalembert principle. Thus obtained equations of kinetostatical for their versatility have been solved by the Cramer rule. Thus, for each GA of the second class were found all 6 unknowns: the forces in the kinematic pairs, the directions of these forces as well as forces the shoulders. If we study kinetostatic mechanism with parallel consolidation of two GA in the initial link, in this case, power is the geometric sum of the forces acting on the primary link from the discarded GA. Thus, the obtained mathematical model kinetostatical calculation mechanisms in the form of libraries of mathematical procedures for determining reactions of all GA of the second class. The mathematical model kinetostatical calculation makes it relatively simple to implement its software implementation.
Hirarchical emotion calculation model for virtual human modellin - biomed 2010.
Zhao, Yue; Wright, David
2010-01-01
This paper introduces a new emotion generation method for virtual human modelling. The method includes a novel hierarchical emotion structure, a group of emotion calculation equations and a simple heuristics decision making mechanism, which enables virtual humans to perform emotionally in real-time according to their internal and external factors. Emotion calculation equations used in this research were derived from psychologic emotion measurements. Virtual humans can utilise the information in virtual memory and emotion calculation equations to generate their own numerical emotion states within the hierarchical emotion structure. Those emotion states are important internal references for virtual humans to adopt appropriate behaviours and also key cues for their decision making. A simple heuristics theory is introduced and integrated into decision making process in order to make the virtual humans decision making more like a real human. A data interface which connects the emotion calculation and the decision making structure together has also been designed and simulated to test the method in Virtools environment.
Modeling and Calculation of Dent Based on Pipeline Bending Strain
Directory of Open Access Journals (Sweden)
Qingshan Feng
2016-01-01
Full Text Available The bending strain of long-distance oil and gas pipelines can be calculated by the in-line inspection tool which used inertial measurement unit (IMU. The bending strain is used to evaluate the strain and displacement of the pipeline. During the bending strain inspection, the dent existing in the pipeline can affect the bending strain data as well. This paper presents a novel method to model and calculate the pipeline dent based on the bending strain. The technique takes inertial mapping data from in-line inspection and calculates depth of dent in the pipeline using Bayesian statistical theory and neural network. To verify accuracy of the proposed method, an in-line inspection tool is used to inspect pipeline to gather data. The calculation of dent shows the method is accurate for the dent, and the mean relative error is 2.44%. The new method provides not only strain of the pipeline dent but also the depth of dent. It is more benefit for integrity management of pipeline for the safety of the pipeline.
Preliminary validation of a Monte Carlo model for IMRT fields
International Nuclear Information System (INIS)
Wright, Tracy; Lye, Jessica; Mohammadi, Mohammad
2011-01-01
Full text: A Monte Carlo model of an Elekta linac, validated for medium to large (10-30 cm) symmetric fields, has been investigated for small, irregular and asymmetric fields suitable for IMRT treatments. The model has been validated with field segments using radiochromic film in solid water. The modelled positions of the multileaf collimator (MLC) leaves have been validated using EBT film, In the model, electrons with a narrow energy spectrum are incident on the target and all components of the linac head are included. The MLC is modelled using the EGSnrc MLCE component module. For the validation, a number of single complex IMRT segments with dimensions approximately 1-8 cm were delivered to film in solid water (see Fig, I), The same segments were modelled using EGSnrc by adjusting the MLC leaf positions in the model validated for 10 cm symmetric fields. Dose distributions along the centre of each MLC leaf as determined by both methods were compared. A picket fence test was also performed to confirm the MLC leaf positions. 95% of the points in the modelled dose distribution along the leaf axis agree with the film measurement to within 1%/1 mm for dose difference and distance to agreement. Areas of most deviation occur in the penumbra region. A system has been developed to calculate the MLC leaf positions in the model for any planned field size.
Preliminary analysis for model development of groundwater evolution in Horonobe area
International Nuclear Information System (INIS)
Yoshida, Yasushi; Yui, Mikazu
2003-03-01
The preliminary analysis for model development of groundwater evolution in Horonobe area was performed with data at D-1, HDB-1 and HDB-2 bore hole where hydrogen / oxygen isotope concentration, mineral property in sedimentary rock and physico-chemical parameters (pH, Eh and ionic concentrations) were measured. As a result of analysis for hydrogen and oxygen isotope concentration, saline water in marine sediment was diluted by the mixing with shallow groundwater and diffusion. And as a result of analysis for a concentration of bicarbonate from the difference of pH values measured between in-situ and under air, the estimated in-situ concentration of bicarbonate differs from that measured under air. And minerals which were assumed to be equilibrium with groundwater were selected by thermodynamic calculation. This report presents the results of preliminary analysis for groundwater evolution by using data derived from D-1, HDB-1 and HDB-2 boring research. In order to establish the model which interprets the groundwater evolution as a next step, data which satisfy the representative in-situ property of groundwater chemistry in Horonobe area are needed. Reliable measurements for physico-chemical parameter and property of minerals in sedimentary rock in dominant layer and at the variety of depth are also needed. (author)
Theoretical model for calculation of molecular stopping power
International Nuclear Information System (INIS)
Xu, Y.J.
1984-01-01
A modified local plasma model based on the work of Linhard-Winther, Bethe, Brown, and Walske is established. The Gordon-Kim's molecular charged density model is employed to obtain a formula to evaluate the stopping power of many useful molecular systems. The stopping power of H 2 and He gas was calculated for incident proton energy ranging from 100 KeV to 2.5 MeV. The stopping power of O 2 , N 2 , and water vapor was also calculated for incident proton energy ranging from 40 keV to 2.5 MeV. Good agreement with experimental data was obtained. A discussion of molecular effects leading to departure from Bragg's rule is presented. The equipartition rule and the effect of nuclear momentum recoiling in stopping power are also discussed in the appendix. The calculation procedure presented hopefully can easily be extended to include the most useful organic systems such as the molecules composed of carbon, nitrogen, hydrogen and oxygen which are useful in radiation protection field
Total energy calculations from self-energy models
International Nuclear Information System (INIS)
Sanchez-Friera, P.
2001-06-01
Density-functional theory is a powerful method to calculate total energies of large systems of interacting electrons. The usefulness of this method, however, is limited by the fact that an approximation is required for the exchange-correlation energy. Currently used approximations (LDA and GGA) are not sufficiently accurate in many physical problems, as for instance the study of chemical reactions. It has been shown that exchange-correlation effects can be accurately described via the self-energy operator in the context of many-body perturbation theory. This is, however, a computationally very demanding approach. In this thesis a new scheme for calculating total energies is proposed, which combines elements from many-body perturbation theory and density-functional theory. The exchange-correlation energy functional is built from a simplified model of the self-energy, that nevertheless retains the main features of the exact operator. The model is built in such way that the computational effort is not significantly increased with respect to that required in a typical density-functional theory calculation. (author)
Calculations of the electrostatic potential adjacent to model phospholipid bilayers.
Peitzsch, R M; Eisenberg, M; Sharp, K A; McLaughlin, S
1995-03-01
We used the nonlinear Poisson-Boltzmann equation to calculate electrostatic potentials in the aqueous phase adjacent to model phospholipid bilayers containing mixtures of zwitterionic lipids (phosphatidylcholine) and acidic lipids (phosphatidylserine or phosphatidylglycerol). The aqueous phase (relative permittivity, epsilon r = 80) contains 0.1 M monovalent salt. When the bilayers contain equipotential surfaces are discrete domes centered over the negatively charged lipids and are approximately twice the value calculated using Debye-Hückel theory. When the bilayers contain > 25% acidic lipid, the -25 mV equipotential profiles are essentially flat and agree well with the values calculated using Gouy-Chapman theory. When the bilayers contain 100% acidic lipid, all of the equipotential surfaces are flat and agree with Gouy-Chapman predictions (including the -100 mV surface, which is located only 1 A from the outermost atoms). Even our model bilayers are not simple systems: the charge on each lipid is distributed over several atoms, these partial charges are non-coplanar, there is a 2 A ion-exclusion region (epsilon r = 80) adjacent to the polar headgroups, and the molecular surface is rough. We investigated the effect of these four factors using smooth (or bumpy) epsilon r = 2 slabs with embedded point charges: these factors had only minor effects on the potential in the aqueous phase.
Freight Calculation Model: A Case Study of Coal Distribution
Yunianto, I. T.; Lazuardi, S. D.; Hadi, F.
2018-03-01
Coal has been known as one of energy alternatives that has been used as energy source for several power plants in Indonesia. During its transportation from coal sites to power plant locations is required the eligible shipping line services that are able to provide the best freight rate. Therefore, this study aims to obtain the standardized formulations for determining the ocean freight especially for coal distribution based on the theoretical concept. The freight calculation model considers three alternative transport modes commonly used in coal distribution: tug-barge, vessel and self-propelled barge. The result shows there are two cost components very dominant in determining the value of freight with the proportion reaching 90% or even more, namely: time charter hire and fuel cost. Moreover, there are three main factors that have significant impacts on the freight calculation, which are waiting time at ports, time charter rate and fuel oil price.
Nuclear model calculations on cyclotron production of {sup 51}Cr
Energy Technology Data Exchange (ETDEWEB)
Kakavand, Tayeb [Imam Khomeini International Univ., Qazvin (Iran, Islamic Republic of). Dept. of Physics; Aboudzadeh, Mohammadreza [Nuclear Science and Technology Research Institute/AEOI, Karaj (Iran, Islamic Republic of). Agricultural, Medical and Industrial Research School; Farahani, Zahra; Eslami, Mohammad [Zanjan Univ. (Iran, Islamic Republic of). Dept. of Physics
2015-12-15
{sup 51}Cr (T{sub 1/2} = 27.7 d), which decays via electron capture (100 %) with 320 keV gamma emission (9.8 %), is a radionuclide with still a large application in biological studies. In this work, ALICE/ASH and TALYS nuclear model codes along with some adjustments are used to calculate the excitation functions for proton, deuteron, α-particle and neutron induced on various targets leading to the production of {sup 51}Cr radioisotope. The production yields of {sup 51}Cr from various reactions are determined using the excitation function calculations and stopping power data. The results are compared with corresponding experimental data and discussed from point of view of feasibility.
Optical model calculation of neutron-nucleus scattering cross sections
International Nuclear Information System (INIS)
Smith, M.E.; Camarda, H.S.
1980-01-01
A program to calculate the total, elastic, reaction, and differential cross section of a neutron interacting with a nucleus is described. The interaction between the neutron and the nucleus is represented by a spherically symmetric complex potential that includes spin-orbit coupling. This optical model problem is solved numerically, and is treated with the partial-wave formalism of scattering theory. The necessary scattering theory required to solve this problem is briefly stated. Then, the numerical methods used to integrate the Schroedinger equation, calculate derivatives, etc., are described, and the results of various programming tests performed are presented. Finally, the program is discussed from a user's point of view, and it is pointed out how and where the program (OPTICAL) can be changed to satisfy particular needs
Preliminary tests of a high speed vertical axis windmill model
Energy Technology Data Exchange (ETDEWEB)
South, P; Rangi, R S
1971-01-01
This report discusses a fixed-pitch vertical axis windmill that combines the inherent simplicity of this type of machine with a high aerodynamic efficiency and a high relative velocity. A three-bladed rotor was selected as the basic design, having constant chord symmetric airfoil blades configured in a catenary curve such that the rotor diameter is equal to the rotor height. In wind tunnel tests using a 30 inch scale model, it was found that once this rotor was given a very low rotational speed, it picked up speed and ran at a rotor tip velocity/wind speed ratio greater than 1. The number of blades was varied in the testing. A maximum power coefficient of 0.67 was achieved at 17 ft/s wind speed at a tip speed/wind speed ratio of 7.25 for a 2-bladed rotor. Increasing the number of blades above 3 did not result in higher power. The rotor could operate in gusts which double the mean wind velocity. Examination of Reynolds number effects, and taking into account the scale of the model, it was concluded that a full-scale windmill could run at lower velocity ratios than those predicted by the model tests, and that it could self-start under no-load conditions if the cut-in rpm are at least half the rpm for maximum power at the prevailing wind speed. Preliminary estimates show that a 15 ft diameter windmill of this design, designed to operate with a safety factor of 2.5 up to a maximum wind speed of 60 ft/s, would weigh ca 150 lb and could be marketed for ca $60.00, excluding the driven unit, if sufficient quantities were produced to make tooling costs negligible. Similarly, a 30 ft windmill would weigh ca 1000 lb and cost ca $400.00. 2 refs., 6 figs.
A relativistic point coupling model for nuclear structure calculations
International Nuclear Information System (INIS)
Buervenich, T.; Maruhn, J.A.; Madland, D.G.; Reinhard, P.G.
2002-01-01
A relativistic point coupling model is discussed focusing on a variety of aspects. In addition to the coupling using various bilinear Dirac invariants, derivative terms are also included to simulate finite-range effects. The formalism is presented for nuclear structure calculations of ground state properties of nuclei in the Hartree and Hartree-Fock approximations. Different fitting strategies for the determination of the parameters have been applied and the quality of the fit obtainable in this model is discussed. The model is then compared more generally to other mean-field approaches both formally and in the context of applications to ground-state properties of known and superheavy nuclei. Perspectives for further extensions such as an exact treatment of the exchange terms using a higher-order Fierz transformation are discussed briefly. (author)
Model for calculation of electrostatic contribution into protein stability
Kundrotas, Petras; Karshikoff, Andrey
2003-03-01
Existing models of the denatured state of proteins consider only one possible spatial distribution of protein charges and therefore are applicable to a limited number of cases. In this presentation a more general framework for the modeling of the denatured state is proposed. It is based on the assumption that the titratable groups of an unfolded protein can adopt a quasi-random distribution, restricted by the protein sequence. The model was tested on two proteins, barnase and N-terminal domain of the ribosomal protein L9. The calculated free energy of denaturation, Δ G( pH), reproduces the experimental data essentially better than the commonly used null approximation (NA). It was demonstrated that the seemingly good agreement with experimental data obtained by NA originates from the compensatory effect between the pair-wise electrostatic interactions and the desolvation energy of the individual sites. It was also found that the ionization properties of denatured proteins are influenced by the protein sequence.
Physical model and calculation code for fuel coolant interactions
International Nuclear Information System (INIS)
Goldammer, H.; Kottowski, H.
1976-01-01
A physical model is proposed to describe fuel coolant interactions in shock-tube geometry. According to the experimental results, an interaction model which divides each cycle into three phases is proposed. The first phase is the fuel-coolant-contact, the second one is the ejection and recently of the coolant, and the third phase is the impact and fragmentation. Physical background of these phases are illustrated in the first part of this paper. Mathematical expressions of the model are exposed in the second part. A principal feature of the computational method is the consistent application of the fourier-equation throughout the whole interaction process. The results of some calculations, performed for different conditions are compiled in attached figures. (Aoki, K.)
Intravascular brachytherapy: a model for the calculation of the dose
International Nuclear Information System (INIS)
Pirchio, Rosana; Martin, Gabriela; Rivera, Elena; Cricco, Graciela; Cocca, Claudia; Gutierrez, Alicia; Nunez, Mariel; Bergoc, Rosa; Guzman, Luis; Belardi, Diego
2002-01-01
In this study we present the radiation dose distribution for a theoretical model with Montecarlo simulation, and based on an experimental model developed for the study of the prevention of restenosis post-angioplasty employing intravascular brachytherapy. In the experimental in vivo model, the atherosclerotic plaques were induced in femoral arteries of male New Zealand rabbits through surgical intervention and later administration of cholesterol enriched diet. For the intravascular irradiation we employed a 32P source contained within the balloon used for the angioplasty. The radiation dose distributions were calculated using the Monte Carlo code MCNP4B according to a segment of a simulated artery. We studied the radiation dose distribution in the axial and radial directions for different thickness of the atherosclerotic plaques. The results will be correlated with the biologic effects observed by means of histological analysis of the irradiated arteries (Au)
MODEL OF FEES CALCULATION FOR ACCESS TO TRACK INFRASTRUCTURE FACILITIES
Directory of Open Access Journals (Sweden)
M. I. Mishchenko
2014-12-01
Full Text Available Purpose. The purpose of the article is to develop a one- and two-element model of the fees calculation for the use of track infrastructure of Ukrainian railway transport. Methodology. On the basis of this one can consider that when planning the planned preventive track repair works and the amount of depreciation charges the guiding criterion is not the amount of progress it is the operating life of the track infrastructure facilities. The cost of PPTRW is determined on the basis of the following: the classification track repairs; typical technological processes for track repairs; technology based time standards for PPTRW; costs for the work of people, performing the PPTRW, their hourly wage rates according to the Order 98-Ts; the operating cost of machinery; regulated list; norms of expenditures and costs of materials and products (they have the largest share of the costs for repairs; railway rates; average distances for transportation of materials used during repair; standards of general production expenses and the administrative costs. Findings. The models offered in article allow executing the objective account of expenses in travelling facilities for the purpose of calculation of the proved size of indemnification and necessary size of profit, the sufficient enterprises for effective activity of a travelling infrastructure. Originality. The methodological bases of determination the fees (payments for the use of track infrastructure on one- and two-element base taking into account the experience of railways in the EC countries and the current transport legislation were grounded. Practical value. The article proposes the one- and two-element models of calculating the fees (payments for the TIF use, accounting the applicable requirements of European transport legislation, which provides the expense compensation and income formation, sufficient for economic incentives of the efficient operation of the TIE of Ukrainian railway transport.
Practical model for the calculation of multiply scattered lidar returns
International Nuclear Information System (INIS)
Eloranta, E.W.
1998-01-01
An equation to predict the intensity of the multiply scattered lidar return is presented. Both the scattering cross section and the scattering phase function can be specified as a function of range. This equation applies when the cloud particles are larger than the lidar wavelength. This approximation considers photon trajectories with multiple small-angle forward-scattering events and one large-angle scattering that directs the photon back toward the receiver. Comparisons with Monte Carlo simulations, exact double-scatter calculations, and lidar data demonstrate that this model provides accurate results. copyright 1998 Optical Society of America
The calculation of exchange forces: General results and specific models
International Nuclear Information System (INIS)
Scott, T.C.; Babb, J.F.; Dalgarno, A.; Morgan, J.D. III
1993-01-01
In order to clarify questions about the calculation of the exchange energy of a homonuclear molecular ion, an analysis is carried out of a model problem consisting of the one-dimensional limit of H 2 + . It is demonstrated that the use of the infinite polarization expansion for the localized wave function in the Holstein--Herring formula yields an approximate exchange energy which at large internuclear distances R has the correct leading behavior to O(e -R ) and is close to but not equal to the exact exchange energy. The extension to the n-dimensional double-well problem is presented
Modeling Dynamic Objects in Monte Carlo Particle Transport Calculations
International Nuclear Information System (INIS)
Yegin, G.
2008-01-01
In this study, the Multi-Geometry geometry modeling technique was improved in order to handle moving objects in a Monte Carlo particle transport calculation. In the Multi-Geometry technique, the geometry is a superposition of objects not surfaces. By using this feature, we developed a new algorithm which allows a user to make enable or disable geometry elements during particle transport. A disabled object can be ignored at a certain stage of a calculation and switching among identical copies of the same object located adjacent poins during a particle simulation corresponds to the movement of that object in space. We called this powerfull feature as Dynamic Multi-Geometry technique (DMG) which is used for the first time in Brachy Dose Monte Carlo code to simulate HDR brachytherapy treatment systems. Our results showed that having disabled objects in a geometry does not effect calculated dose values. This technique is also suitable to be used in other areas such as IMRT treatment planning systems
Determination of appropriate models and parameters for premixing calculations
Energy Technology Data Exchange (ETDEWEB)
Park, Ik-Kyu; Kim, Jong-Hwan; Min, Beong-Tae; Hong, Seong-Wan
2008-03-15
The purpose of the present work is to use experiments that have been performed at Forschungszentrum Karlsruhe during about the last ten years for determining the most appropriate models and parameters for premixing calculations. The results of a QUEOS experiment are used to fix the parameters concerning heat transfer. The QUEOS experiments are especially suited for this purpose as they have been performed with small hot solid spheres. Therefore the area of heat exchange is known. With the heat transfer parameters fixed in this way, a PREMIX experiment is recalculated. These experiments have been performed with molten alumina (Al{sub 2}O{sub 3}) as a simulant of corium. Its initial temperature is 2600 K. With these experiments the models and parameters for jet and drop break-up are tested.
Determination of appropriate models and parameters for premixing calculations
International Nuclear Information System (INIS)
Park, Ik-Kyu; Kim, Jong-Hwan; Min, Beong-Tae; Hong, Seong-Wan
2008-03-01
The purpose of the present work is to use experiments that have been performed at Forschungszentrum Karlsruhe during about the last ten years for determining the most appropriate models and parameters for premixing calculations. The results of a QUEOS experiment are used to fix the parameters concerning heat transfer. The QUEOS experiments are especially suited for this purpose as they have been performed with small hot solid spheres. Therefore the area of heat exchange is known. With the heat transfer parameters fixed in this way, a PREMIX experiment is recalculated. These experiments have been performed with molten alumina (Al 2 O 3 ) as a simulant of corium. Its initial temperature is 2600 K. With these experiments the models and parameters for jet and drop break-up are tested
Calculating excess lifetime risk in relative risk models
International Nuclear Information System (INIS)
Vaeth, M.; Pierce, D.A.
1990-01-01
When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate
Recent Developments in No-Core Shell-Model Calculations
International Nuclear Information System (INIS)
Navratil, P.; Quaglioni, S.; Stetcu, I.; Barrett, B.R.
2009-01-01
We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this aproach, we start from realistic two-nucleon or two- plus three-nucleon interactions. Many-body calculations are performed using a finite harmonic-oscillator (HO) basis. To facilitate convergence for realistic inter-nucleon interactions that generate strong short-range correlations, we derive effective interactions by unitary transformations that are tailored to the HO basis truncation. For soft realistic interactions this might not be necessary. If that is the case, the NCSM calculations are variational. In either case, the ab initio NCSM preserves translational invariance of the nuclear many-body problem. In this review, we, in particular, highlight results obtained with the chiral two- plus three-nucleon interactions. We discuss efforts to extend the applicability of the NCSM to heavier nuclei and larger model spaces using importance-truncation schemes and/or use of effective interactions with a core. We outline an extension of the ab initio NCSM to the description of nuclear reactions by the resonating group method technique. A future direction of the approach, the ab initio NCSM with continuum, which will provide a complete description of nuclei as open systems with coupling of bound and continuum states is given in the concluding part of the review.
Recent Developments in No-Core Shell-Model Calculations
Energy Technology Data Exchange (ETDEWEB)
Navratil, P; Quaglioni, S; Stetcu, I; Barrett, B R
2009-03-20
We present an overview of recent results and developments of the no-core shell model (NCSM), an ab initio approach to the nuclear many-body problem for light nuclei. In this aproach, we start from realistic two-nucleon or two- plus three-nucleon interactions. Many-body calculations are performed using a finite harmonic-oscillator (HO) basis. To facilitate convergence for realistic inter-nucleon interactions that generate strong short-range correlations, we derive effective interactions by unitary transformations that are tailored to the HO basis truncation. For soft realistic interactions this might not be necessary. If that is the case, the NCSM calculations are variational. In either case, the ab initio NCSM preserves translational invariance of the nuclear many-body problem. In this review, we, in particular, highlight results obtained with the chiral two- plus three-nucleon interactions. We discuss efforts to extend the applicability of the NCSM to heavier nuclei and larger model spaces using importance-truncation schemes and/or use of effective interactions with a core. We outline an extension of the ab initio NCSM to the description of nuclear reactions by the resonating group method technique. A future direction of the approach, the ab initio NCSM with continuum, which will provide a complete description of nuclei as open systems with coupling of bound and continuum states is given in the concluding part of the review.
Modeling and calculation of open carbon dioxide refrigeration system
International Nuclear Information System (INIS)
Cai, Yufei; Zhu, Chunling; Jiang, Yanlong; Shi, Hong
2015-01-01
Highlights: • A model of open refrigeration system is developed. • The state of CO 2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO 2 has little relation to the state of CO 2 . • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration
Multidirectional Networks of Government Transparency: A Preliminary Model
Directory of Open Access Journals (Sweden)
Ahmad Subhan
2016-11-01
Full Text Available This article reviews some literature in theoretical level regarding two concepts: governance network and government transparency, in order to search for theoretical linkages and to build an alternative framework that can support the implementation of public disclosure. Transparency agenda has been implemented in various forms at international, national, and local level. Transparency application was also followed by Indonesia with the implementation of Public Information Disclosure Law since 2008. This enthusiasm is quite reasonable because transparency is believed to be one of the human rights principles; as well as a key to better governance, that can help democracy consolidation, prevent corruption, strengthen the legitimacy and improve efficiency. In order to maximize transparency, the government can use a network approach because of some changes at this time, such as democratization, decentralization, and liberalization has placed the government in a position where there is not one actor who manages the state power without stakeholder’s participation. In this context, the government needs to build synergies with other institutions in a reciprocal relationship with all stakeholders. Therefore, adopting the theory of government networks can be one of the strategies to strengthen government transparency. The findings of this article indicate that the government transparency application needs to develop networks in all directions: intragovernmental, intergovernmental and collaborative networks. These three types of network in contrast with the popular belief that government transparency is interpreted only as a procedural activity to outside parties. A preliminary model in this article gives an overview about the arena of government transparency with multi-directional networks more comprehensively.
Computational models for probabilistic neutronic calculation in TADSEA
International Nuclear Information System (INIS)
Garcia, Jesus A.R.; Curbelo, Jesus P.; Hernandez, Carlos R.G.; Oliva, Amaury M.; Lira, Carlos A.B.O.
2013-01-01
The Very High Temperature Reactor is one of the main candidates for the next generation of nuclear power plants. In pebble bed reactors, the fuel is contained within graphite pebbles in the form of TRISO particles, which form a randomly packed bed inside a graphite-walled cylindrical cavity. In previous studies, the conceptual design of a Transmutation Advanced Device for Sustainable Energy Applications (TADSEA) has been made. The TADSEA is a pebble-bed ADS cooled by helium and moderated by graphite. In order to simulate the TADSEA correctly, the double heterogeneity of the system must be considered. It consists on randomly located pebbles into the core and randomly located TRISO particles into the fuel pebbles. These features are often neglected due to the difficulty to model with MCNP code. The main reason is that there is a limited number of cells and surfaces to be defined. In this paper a computational tool, which allows to get a new geometrical model for fuel pebble to neutronic calculation with MCNPX, was presented. The heterogeneity of system is considered, and also the randomly located TRISO particles inside the pebble. There are also compared several neutronic computational models for TADSEA's fuel pebbles in order to study heterogeneity effects. On the other hand the boundary effect given by the intersection between the pebble surface and the TRISO particles could be significative in the multiplicative properties. A model to study this e ect is also presented. (author)
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
Development of nuclear models for higher energy calculations
International Nuclear Information System (INIS)
Bozoian, M.; Siciliano, E.R.; Smith, R.D.
1988-01-01
Two nuclear models for higher energy calculations have been developed in the regions of high and low energy transfer, respectively. In the former, a relativistic hybrid-type preequilibrium model is compared with data ranging from 60 to 800 MeV. Also, the GNASH exciton preequilibrium-model code with higher energy improvements is compared with data at 200 and 318 MeV. In the region of low energy transfer, nucleon-nucleus scattering is predominately a direct reaction involving quasi-elastic collisions with one or more target nucleons. We discuss various aspects of quasi-elastic scattering which are important in understanding features of cross sections and spin observables. These include (1) contributions from multi-step processes; (2) damping of the continuum response from 2p-2h excitations; (3) the ''optimal'' choice of frame in which to evaluate the nucleon-nucleon amplitudes; and (4) the effect of optical and spin-orbit distortions, which are included in a model based on the RPA the DWIA and the eikonal approximation. 33 refs., 15 figs
Updated thermal model using simplified short-wave radiosity calculations
International Nuclear Information System (INIS)
Smith, J.A.; Goltz, S.M.
1994-01-01
An extension to a forest canopy thermal radiance model is described that computes the short-wave energy flux absorbed within the canopy by solving simplified radiosity equations describing flux transfers between canopy ensemble classes partitioned by vegetation layer and leaf slope. Integrated short-wave reflectance and transmittance-factors obtained from measured leaf optical properties were found to be nearly equal for the canopy studied. Short-wave view factor matrices were approximated by combining the average leaf scattering coefficient with the long-wave view factor matrices already incorporated in the model. Both the updated and original models were evaluated for a dense spruce fir forest study site in Central Maine. Canopy short-wave absorption coefficients estimated from detailed Monte Carlo ray tracing calculations were 0.60, 0.04, and 0.03 for the top, middle, and lower canopy layers corresponding to leaf area indices of 4.0, 1.05, and 0.25. The simplified radiosity technique yielded analogous absorption values of 0.55, 0.03, and 0.01. The resulting root mean square error in modeled versus measured canopy temperatures for all layers was less than 1°C with either technique. Maximum error in predicted temperature using the simplified radiosity technique was approximately 2°C during peak solar heating. (author)
Updated thermal model using simplified short-wave radiosity calculations
Energy Technology Data Exchange (ETDEWEB)
Smith, J. A.; Goltz, S. M.
1994-02-15
An extension to a forest canopy thermal radiance model is described that computes the short-wave energy flux absorbed within the canopy by solving simplified radiosity equations describing flux transfers between canopy ensemble classes partitioned by vegetation layer and leaf slope. Integrated short-wave reflectance and transmittance-factors obtained from measured leaf optical properties were found to be nearly equal for the canopy studied. Short-wave view factor matrices were approximated by combining the average leaf scattering coefficient with the long-wave view factor matrices already incorporated in the model. Both the updated and original models were evaluated for a dense spruce fir forest study site in Central Maine. Canopy short-wave absorption coefficients estimated from detailed Monte Carlo ray tracing calculations were 0.60, 0.04, and 0.03 for the top, middle, and lower canopy layers corresponding to leaf area indices of 4.0, 1.05, and 0.25. The simplified radiosity technique yielded analogous absorption values of 0.55, 0.03, and 0.01. The resulting root mean square error in modeled versus measured canopy temperatures for all layers was less than 1°C with either technique. Maximum error in predicted temperature using the simplified radiosity technique was approximately 2°C during peak solar heating. (author)
Energy Technology Data Exchange (ETDEWEB)
Kneur, J.L
2006-06-15
This document is divided into 2 parts. The first part describes a particular re-summation technique of perturbative series that can give a non-perturbative results in some cases. We detail some applications in field theory and in condensed matter like the calculation of the effective temperature of Bose-Einstein condensates. The second part deals with the minimal supersymmetric standard model. We present an accurate calculation of the mass spectrum of supersymmetric particles, a calculation of the relic density of supersymmetric black matter, and the constraints that we can infer from models.
Cluster model calculations of the solid state materials electron structure
International Nuclear Information System (INIS)
Pelikan, P.; Biskupic, S.; Banacky, P.; Zajac, A.; Svrcek, A.; Noga, J.
1997-01-01
Materials of the general composition ACuO 2 are the parent compounds of so called infinite layer superconductors. In the paper presented the electron structure of the compounds CaCuO 2 , SrCuO2, Ca 0.86 Sr 0.14 CuO2 and Ca 0.26 Sr 0.74 CuO 2 were calculated. The cluster models consisting of 192 atoms were computed using quasi relativistic version of semiempirical INDO method. The obtained results indicate the strong ionicity of Ca/Sr-O bonds and high covalency of Cu-bonds. The width of energy gap at the Fermi level increases as follows: Ca 0.26 Sr 0.74 CuO 2 0.86 Sr 0.14 CuO2 2 . This order correlates with the fact that materials of the composition Ca x Sr 1-x CuO 2 have have the high temperatures of the superconductive transition (up to 110 K). Materials partially substituted by Sr 2+ have also the higher density of states in the close vicinity at the Fermi level that ai the additional condition for the possibility of superconductive transition. It was calculated the strong influence of the vibration motions to the energy gap at the Fermi level. (authors). 1 tabs., 2 figs., 10 refs
Selection of models to calculate the LLW source term
International Nuclear Information System (INIS)
Sullivan, T.M.
1991-10-01
Performance assessment of a LLW disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). In turn, many of these physical processes are influenced by the design of the disposal facility (e.g., infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This document provides a brief overview of disposal practices and reviews existing source term models as background for selecting appropriate models for estimating the source term. The selection rationale and the mathematical details of the models are presented. Finally, guidance is presented for combining the inventory data with appropriate mechanisms describing release from the disposal facility. 44 refs., 6 figs., 1 tab
Calculational models of close-spaced thermionic converters
International Nuclear Information System (INIS)
McVey, J.B.
1983-01-01
Two new calculational models have been developed in conjunction with the SAVTEC experimental program. These models have been used to analyze data from experimental close-spaced converters, providing values for spacing, electrode work functions, and converter efficiency. They have also been used to make performance predictions for such converters over a wide range of conditions. Both models are intended for use in the collisionless (Knudsen) regime. They differ from each other in that the simpler one uses a Langmuir-type formulation which only considers electrons emitted from the emitter. This approach is implemented in the LVD (Langmuir Vacuum Diode) computer program, which has the virtue of being both simple and fast. The more complex model also includes both Saha-Langmuir emission of positive cesium ions from the emitter and collector back emission. Computer implementation is by the KMD1 (Knudsen Mode Diode) program. The KMD1 model derives the particle distribution functions from the Vlasov equation. From these the particle densities are found for various interelectrode motive shapes. Substituting the particle densities into Poisson's equation gives a second order differential equation for potential. This equation can be integrated once analytically. The second integration, which gives the interelectrode motive, is performed numerically by the KMD1 program. This is complicated by the fact that the integrand is often singular at one end point of the integration interval. The program performs a transformation on the integrand to make it finite over the entire interval. Once the motive has been computed, the output voltage, current density, power density, and efficiency are found. The program is presently unable to operate when the ion richness ratio β is between about .8 and 1.0, due to the occurrence of oscillatory motives
International Nuclear Information System (INIS)
Mueller, R.G.
1987-06-01
Due to the strong influence of vapour bubbles on the nuclear chain reaction, an exact calculation of neutron physics and thermal hydraulics in light water reactors requires consideration of subcooled boiling. To this purpose, in the present study a dynamic model is derived from the time-dependent conservation equations. It contains new methods for the time-dependent determination of evaporation and condensation heat flow and for the heat transfer coefficient in subcooled boiling. Furthermore, it enables the complete two-phase flow region to be treated in a consistent manner. The calculation model was verified using measured data of experiments covering a wide range of thermodynamic boundary conditions. In all cases very good agreement was reached. The results from the coupling of the new calculation model with a neutron kinetics program proved its suitability for the steady-state and transient calculation of reactor cores. (orig.) [de
2015-06-01
of JP-8 and a Fischer- Tropsch synthetic jet fuel following subacute inhalation exposure in rats. Toxicol Sci 116(1): 239-248. Gallinat, J...AFRL-RH-WP-TR-2015-0084 IN VITRO STUDIES AND PRELIMINARY MATHEMATICAL MODEL FOR JET FUEL AND NOISE INDUCED AUDITORY IMPAIRMENT...April 2014 – September 2014 4. TITLE AND SUBTITLE In Vitro Studies and Preliminary Mathematical Model for Jet Fuel and Noise Induced Auditory
Calculating ε'/ε in the standard model
International Nuclear Information System (INIS)
Sharpe, S.R.
1988-01-01
The ingredients needed in order to calculate ε' and ε are described. Particular emphasis is given to the non-perturbative calculations of matrix elements by lattice methods. The status of the electromagnetic contribution to ε' is reviewed. 15 refs
The effects of electric forces on dust lifting: Preliminary studies with a numerical model
International Nuclear Information System (INIS)
Kok, J F; Renno, N O
2008-01-01
Atmospheric dust aerosols affect the Earth's climate by scattering and absorbing radiation and by modifying cloud properties. Recent experiments have indicated that electric fields produced in dusty phenomena such as dust storms and dust devils could enhance the emission of dust aerosols. However, the generation of electric fields in dusty phenomena is poorly understood. To address this problem, we present results from the first physically-based numerical model of electric fields in dust lifting. Our model calculates the motion and collisions of air-borne particles, as well as the charge transfer during these collisions. This allows us to simulate the formation of electric fields as a function of physical parameters, such as wind stress and soil properties. Preliminary model results show that electric fields can indeed enhance the lifting of soil particles. Moreover, they suggest that strong electric fields could trigger a positive feedback because increases in the concentration of charged particles strengthen the original electric field, which in turn lifts additional surface particles. We plan to further test and calibrate our model with experimental data.
Energy Technology Data Exchange (ETDEWEB)
Mein, S [Duke University Medical Physics Graduate Program (United States); Gunasingha, R [Department of Radiation Safety, Duke University Medical Center (United States); Nolan, M [Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University (United States); Oldham, M; Adamson, J [Department of Radiation Oncology, Duke University Medical Center (United States)
2016-06-15
Purpose: X-PACT is an experimental cancer therapy where kV x-rays are used to photo-activate anti-cancer therapeutics through phosphor intermediaries (phosphors that absorb x-rays and re-radiate as UV light). Clinical trials in pet dogs are currently underway (NC State College of Veterinary Medicine) and an essential component is the ability to model the kV dose in these dogs. Here we report the commissioning and characterization of a Monte Carlo (MC) treatment planning simulation tool to calculate X-PACT radiation doses in canine trials. Methods: FLUKA multi-particle MC simulation package was used to simulate a standard X-PACT radiation treatment beam of 80kVp with the Varian OBI x-ray source geometry. The beam quality was verified by comparing measured and simulated attenuation of the beam by various thicknesses of aluminum (2–4.6 mm) under narrow beam conditions (HVL). The beam parameters at commissioning were then corroborated using MC, characterized and verified with empirically collected commissioning data, including: percent depth dose curves (PDD), back-scatter factors (BSF), collimator scatter factor(s), and heel effect, etc. All simulations were conducted for N=30M histories at M=100 iterations. Results: HVL and PDD simulation data agreed with an average percent error of 2.42%±0.33 and 6.03%±1.58, respectively. The mean square error (MSE) values for HVL and PDD (0.07% and 0.50%) were low, as expected; however, longer simulations are required to validate convergence to the expected values. Qualitatively, pre- and post-filtration source spectra matched well with 80kVp references generated via SPEKTR software. Further validation of commissioning data simulation is underway in preparation for first-time 3D dose calculations with canine CBCT data. Conclusion: We have prepared a Monte Carlo simulation capable of accurate dose calculation for use with ongoing X-PACT canine clinical trials. Preliminary results show good agreement with measured data and hold
Comparative analysis of calculation models of railway subgrade
Directory of Open Access Journals (Sweden)
I.O. Sviatko
2013-08-01
Full Text Available Purpose. In transport engineering structures design, the primary task is to determine the parameters of foundation soil and nuances of its work under loads. It is very important to determine the parameters of shear resistance and the parameters, determining the development of deep deformations in foundation soils, while calculating the soil subgrade - upper track structure interaction. Search for generalized numerical modeling methods of embankment foundation soil work that include not only the analysis of the foundation stress state but also of its deformed one. Methodology. The analysis of existing modern and classical methods of numerical simulation of soil samples under static load was made. Findings. According to traditional methods of analysis of ground masses work, limitation and the qualitative estimation of subgrade deformations is possible only indirectly, through the estimation of stress and comparison of received values with the boundary ones. Originality. A new computational model was proposed in which it will be applied not only classical approach analysis of the soil subgrade stress state, but deformed state will be also taken into account. Practical value. The analysis showed that for accurate analysis of ground masses work it is necessary to develop a generalized methodology for analyzing of the rolling stock - railway subgrade interaction, which will use not only the classical approach of analyzing the soil subgrade stress state, but also take into account its deformed one.
Accurate Holdup Calculations with Predictive Modeling & Data Integration
Energy Technology Data Exchange (ETDEWEB)
Azmy, Yousry [North Carolina State Univ., Raleigh, NC (United States). Dept. of Nuclear Engineering; Cacuci, Dan [Univ. of South Carolina, Columbia, SC (United States). Dept. of Mechanical Engineering
2017-04-03
In facilities that process special nuclear material (SNM) it is important to account accurately for the fissile material that enters and leaves the plant. Although there are many stages and processes through which materials must be traced and measured, the focus of this project is material that is “held-up” in equipment, pipes, and ducts during normal operation and that can accumulate over time into significant quantities. Accurately estimating the holdup is essential for proper SNM accounting (vis-à-vis nuclear non-proliferation), criticality and radiation safety, waste management, and efficient plant operation. Usually it is not possible to directly measure the holdup quantity and location, so these must be inferred from measured radiation fields, primarily gamma and less frequently neutrons. Current methods to quantify holdup, i.e. Generalized Geometry Holdup (GGH), primarily rely on simple source configurations and crude radiation transport models aided by ad hoc correction factors. This project seeks an alternate method of performing measurement-based holdup calculations using a predictive model that employs state-of-the-art radiation transport codes capable of accurately simulating such situations. Inverse and data assimilation methods use the forward transport model to search for a source configuration that best matches the measured data and simultaneously provide an estimate of the level of confidence in the correctness of such configuration. In this work the holdup problem is re-interpreted as an inverse problem that is under-determined, hence may permit multiple solutions. A probabilistic approach is applied to solving the resulting inverse problem. This approach rates possible solutions according to their plausibility given the measurements and initial information. This is accomplished through the use of Bayes’ Theorem that resolves the issue of multiple solutions by giving an estimate of the probability of observing each possible solution. To use
Glass operational file. Operational models and integration calculations
International Nuclear Information System (INIS)
Ribet, I.
2004-01-01
This document presents the operational choices of dominating phenomena, hypotheses, equations and numerical data of the parameters used in the two operational models elaborated for the calculation of the glass source terms with respect to the waste packages considered: existing packages (R7T7, AVM and CEA glasses) and future ones (UOX2, UOX3, UMo, others). The overall operational choices are justified and demonstrated and a critical analysis of the approach is systematically proposed. The use of the operational model (OPM) V 0 → V r , realistic, conservative and robust, is recommended for glasses with a high thermal and radioactive load, which represent the main part of the vitrified wastes. The OPM V 0 S, much more overestimating but faster to parameterize, can be used for the long-term behaviour forecasting of glasses with low thermal and radioactive load, considering today's lack of knowledge for the parameterization of a V 0 → V r type OPM. Efficiency estimations have been made for R7T7 glasses (OPM V 0 → V r ) and AVM glasses (OPM V 0 S), which correspond to more than 99.9% of the vitrified waste packages activity. The very contrasted results obtained, illustrate the importance of the choice of operational models: in conditions representative of a geologic disposal, the estimation of R7T7-type package lifetime exceeds several hundred thousands years. Even if the estimated lifetime of AVM packages is much shorter (because of the overestimating character of the OPM V 0 S), the release potential radiotoxicity is of the same order as the one of R7T7 packages. (J.S.)
Groundwater flow modelling under ice sheet conditions. Scoping calculations
Energy Technology Data Exchange (ETDEWEB)
Jaquet, O.; Namar, R. (In2Earth Modelling Ltd (Switzerland)); Jansson, P. (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden))
2010-10-15
The potential impact of long-term climate changes has to be evaluated with respect to repository performance and safety. In particular, glacial periods of advancing and retreating ice sheet and prolonged permafrost conditions are likely to occur over the repository site. The growth and decay of ice sheets and the associated distribution of permafrost will affect the groundwater flow field and its composition. As large changes may take place, the understanding of groundwater flow patterns in connection to glaciations is an important issue for the geological disposal at long term. During a glacial period, the performance of the repository could be weakened by some of the following conditions and associated processes: - Maximum pressure at repository depth (canister failure). - Maximum permafrost depth (canister failure, buffer function). - Concentration of groundwater oxygen (canister corrosion). - Groundwater salinity (buffer stability). - Glacially induced earthquakes (canister failure). Therefore, the GAP project aims at understanding key hydrogeological issues as well as answering specific questions: - Regional groundwater flow system under ice sheet conditions. - Flow and infiltration conditions at the ice sheet bed. - Penetration depth of glacial meltwater into the bedrock. - Water chemical composition at repository depth in presence of glacial effects. - Role of the taliks, located in front of the ice sheet, likely to act as potential discharge zones of deep groundwater flow. - Influence of permafrost distribution on the groundwater flow system in relation to build-up and thawing periods. - Consequences of glacially induced earthquakes on the groundwater flow system. Some answers will be provided by the field data and investigations; the integration of the information and the dynamic characterisation of the key processes will be obtained using numerical modelling. Since most of the data are not yet available, some scoping calculations are performed using the
Groundwater flow modelling under ice sheet conditions. Scoping calculations
International Nuclear Information System (INIS)
Jaquet, O.; Namar, R.; Jansson, P.
2010-10-01
The potential impact of long-term climate changes has to be evaluated with respect to repository performance and safety. In particular, glacial periods of advancing and retreating ice sheet and prolonged permafrost conditions are likely to occur over the repository site. The growth and decay of ice sheets and the associated distribution of permafrost will affect the groundwater flow field and its composition. As large changes may take place, the understanding of groundwater flow patterns in connection to glaciations is an important issue for the geological disposal at long term. During a glacial period, the performance of the repository could be weakened by some of the following conditions and associated processes: - Maximum pressure at repository depth (canister failure). - Maximum permafrost depth (canister failure, buffer function). - Concentration of groundwater oxygen (canister corrosion). - Groundwater salinity (buffer stability). - Glacially induced earthquakes (canister failure). Therefore, the GAP project aims at understanding key hydrogeological issues as well as answering specific questions: - Regional groundwater flow system under ice sheet conditions. - Flow and infiltration conditions at the ice sheet bed. - Penetration depth of glacial meltwater into the bedrock. - Water chemical composition at repository depth in presence of glacial effects. - Role of the taliks, located in front of the ice sheet, likely to act as potential discharge zones of deep groundwater flow. - Influence of permafrost distribution on the groundwater flow system in relation to build-up and thawing periods. - Consequences of glacially induced earthquakes on the groundwater flow system. Some answers will be provided by the field data and investigations; the integration of the information and the dynamic characterisation of the key processes will be obtained using numerical modelling. Since most of the data are not yet available, some scoping calculations are performed using the
Calculation of real optical model potential for heavy ions in the framework of the folding model
International Nuclear Information System (INIS)
Goncharov, S.A.; Timofeyuk, N.K.; Kazacha, G.S.
1987-01-01
The code for calculation of a real optical model potential in the framework of the folding model is realized. The program of numerical Fourier-Bessel transformation based on Filon's integration rule is used. The accuracy of numerical calculations is ∼ 10 -4 for a distance interval up to a bout (2.5-3) times the size of nuclei. The potentials are calculated for interactions of 3,4 He with nuclei from 9 Be to 27 Al with different effective NN-interactions and densities obtained from electron scattering data. Calculated potentials are similar to phenomenological potentials in Woods-Saxon form. With calculated potentials the available elastic scattering data for the considered nuclei in the energy interval 18-56 MeV are analysed. The needed renormalizations for folding potentials are < or approx. 20%
Models for calculation of dissociation energies of homonuclear diatomic molecules
International Nuclear Information System (INIS)
Brewer, L.; Winn, J.S.
1979-08-01
The variation of known dissociation energies of the transition metal diatomics across the Periodic Table is rather irregular like the bulk sublimation enthalpy, suggesting that the valence-bond model for bulk metallic systems might be applicable to the gaseous diatomic molecules and the various intermediate clusters. Available dissociation energies were converted to valence-state bonding energies considering various degrees of promotion to optimize the bonding. The degree of promotion of electrons to increase the number of bonding electrons is smaller than for the bulk, but the trends in bonding energy parallel the behavior found for the bulk metals. Thus using the established trends in bonding energies for the bulk elements, it was possible to calculate all unknown dissociation energies to provide a complete table of dissociation energies for all M 2 molecules from H 2 to Lr 2 . For solids such as Mg, Al, Si and most of the transition metals, large promotion energies are offset by strong bonding between the valence state atoms. The main question is whether bonding in the diatomics is adequate to sustain extensive promotion. The most extreme example for which a considerable difference would be expected between the bulk and the diatomics would be that of the Group IIA and IIB metals. The first section of this paper which deals with the alkaline earths Mg and Ca demonstrates a significant influence of the excited valence state even for these elements. The next section then expands the treatment to transition metals
The COST model for calculation of forest operations costs
Ackerman, P.; Belbo, H.; Eliasson, L.; Jong, de J.J.; Lazdins, A.; Lyons, J.
2014-01-01
Since the late nineteenth century when high-cost equipment was introduced into forestry there has been a need to calculate the cost of this equipment in more detail with respect to, for example, cost of ownership, cost per hour of production, and cost per production unit. Machine cost calculations
Stochastic index model for intermittent regimes: from preliminary analysis to regionalisation
Directory of Open Access Journals (Sweden)
M. Rianna
2011-04-01
Full Text Available In small and medium-sized basins or in rivers characterized by intermittent discharges, with low or negligible/null observed values for long periods of the year, the correct representation of the discharge regime is important for issues related to water management and to define the amount and quality of water available for irrigation, domestic and recreational uses. In these cases, only one index as a statistical metric is often not enough; it is thus necessary to introduce Flow Duration Curves (FDC.
The aim of this study is therefore to combine a stochastic index flow model capable of reproducing the FDC record period of a river, regardless of the persistence and seasonality of the series, with the theory of total probability in order to calculate how often a river is dry.
The paper draws from preliminary analyses, including a study to estimate the correlation between discharge indicators Q_{95}, Q_{50} and Q_{1} (discharges exceeding 95%, 50% or 1% of the time, respectively and some fundamental characteristics of the basin, as well as to identify homogeneous regions in the target area through the study of several geo-morphological features and climatic conditions. The stochastic model was then applied in one of the homogeneous regions that includes intermittent rivers.
Finally, the model was regionalized by means of regression analysis in order to calculate the FDC for ungauged basins; the reliability of this method was tested using jack-knife validation.
Improvements in the model of neutron calculations for research reactors
International Nuclear Information System (INIS)
Calzetta, Osvaldo; Leszczynski, Francisco
1987-01-01
Within the research program in the field of neutron physics calculations being carried out in the Nuclear Engineering Division at the Centro Atomico Bariloche, the errors which due to some typical approximations appear in the final results are researched. For research MTR type reactors, two approximations, for high and low enrichment are investigated: the treatment of the geometry and the method of few-group cell cross-sections calculation, particularly in the resonance energy region. Commonly, the cell constants used for the entire reactor calculation are obtained making an homogenization of the full fuel elements, by one-dimensional calculations. An improvement is made that explicitly includes the fuel element frames in the core calculation geometry. Besides, a detailed treatment-in energy and space- is used to find the resonance few-group cross sections, and a comparison of the results with detailed and approximated calculations is made. The least number and the best mesh of energy groups needed for cell calculations is fixed too. (Author) [es
International Nuclear Information System (INIS)
Ainsworth, T.L.
1983-01-01
The Δ(1232) plays an important role in determining the properties of nuclear and neutron matter. The effects of the Δ resonance are incorporated explicitly by using a coupled channel formalism. A method for constraining a lowest order variational calculation, appropriate when nucleon internal degrees of freedom are made explicity, is presented. Different N-N potentials were calculated and fit to phase shift data and deuteron properties. The potentials were constructed to test the relative importance of the Δ resonance on nuclear properties. The symmetry energy and incompressibility of nuclear matter are generally reproduced by this calculation. Neutron matter results lead to appealing neutron star models. Fermi liquid parameters for 3 He are calculated with a model that includes both direct and induced terms. A convenient form of the direct interaction is obtained in terms of the parameters. The form of the direct interaction ensures that the forward scattering sum rule (Pauli principle) is obeyed. The parameters are adjusted to fit the experimentally determined F 0 /sup s/, F 0 /sup a/, and F 1 /sup s/ Landau parameters. Higher order Landau parameters are calculated by the self-consistent solution of the equations; comparison to experiment is good. The model also leads to a preferred value for the effective mass of 3 He. Of the three parameters only one shows any dependence on pressure. An exact sum rule is derived relating this parameter to a specific summation of Landau parameters
Hierarchical modeling and robust synthesis for the preliminary design of large scale complex systems
Koch, Patrick Nathan
Large-scale complex systems are characterized by multiple interacting subsystems and the analysis of multiple disciplines. The design and development of such systems inevitably requires the resolution of multiple conflicting objectives. The size of complex systems, however, prohibits the development of comprehensive system models, and thus these systems must be partitioned into their constituent parts. Because simultaneous solution of individual subsystem models is often not manageable iteration is inevitable and often excessive. In this dissertation these issues are addressed through the development of a method for hierarchical robust preliminary design exploration to facilitate concurrent system and subsystem design exploration, for the concurrent generation of robust system and subsystem specifications for the preliminary design of multi-level, multi-objective, large-scale complex systems. This method is developed through the integration and expansion of current design techniques: (1) Hierarchical partitioning and modeling techniques for partitioning large-scale complex systems into more tractable parts, and allowing integration of subproblems for system synthesis, (2) Statistical experimentation and approximation techniques for increasing both the efficiency and the comprehensiveness of preliminary design exploration, and (3) Noise modeling techniques for implementing robust preliminary design when approximate models are employed. The method developed and associated approaches are illustrated through their application to the preliminary design of a commercial turbofan turbine propulsion system; the turbofan system-level problem is partitioned into engine cycle and configuration design and a compressor module is integrated for more detailed subsystem-level design exploration, improving system evaluation.
Modelling of extreme gusts for design calculations (NewGust)
Energy Technology Data Exchange (ETDEWEB)
Bierbooms, W; Cheng, Po-Wen [Delft Univ. of Technology, Inst. for Wind Energy, Delft (Netherlands); Larsen, G [Risoe National Lab., Roskilde (Denmark); Juul Pedersen, B [Vestas Wind Systems A/S, Lem (Denmark); Hansen, K [Tecnical Univ. of Denmark (Denmark)
1999-03-01
The main objective of the NewGust project is to come to a realistic and verified description of extreme gusts based on the stochastic properties of wind. In this paper the first results of the project are presented. Theoretical considerations indicate that the shape of extreme gusts is very sharp. Based on simulated wind time series, mean gust shapes (for several amplitudes and mean wind speeds) are determined and compared with the theoretical curves. The resemblance turned out to be very good. Furthermore, the influence of the sampling rate and the dynamics of a cup anemometer on the empirical mean gust shape are examined. The promising results are confirmed by a (preliminary) verification based on measured wind time series, available from the database on wind characteristics. The mean shape of gusts, of certain amplitude, together with their probability of occurrence can be used to obtain the distribution of the extreme response of wind turbines to gust loading. (au)
Comparison of standard fast reactor calculations (Baker model)
Energy Technology Data Exchange (ETDEWEB)
Voropaev, A I; Van' kov, A A; Tsybulya, A M
1978-12-01
Compared are standard fast reactor calculations performed at different laboratories using several nuclear data files: BNAB-70 and OSKAR-75 (the USSR), CARNAVAL-4 (France), FD-5 (Great Britain), KFK-INR (West Germany), ENDF/B4 (the USA). Three fuel compositions were chosen: (1) /sup 239/Pu and /sup 238/U; (2) /sup 239/Pu, /sup 238/U and fission products; (3) /sup 239/Pu, /sup 240/Pu, /sup 238/U and fission products. Medium temperature was 300K. The calculations have been conducted in the diffusion approximation. Data on critical masses and breeding ratios are tabulated. Discrepancies in the calculations of all the characteristics are small since all the countries possess practically the same nuclear data files.
Calculational advance in the modeling of fuel-coolant interactions
International Nuclear Information System (INIS)
Bohl, W.R.
1982-01-01
A new technique is applied to numerically simulate a fuel-coolant interaction. The technique is based on the ability to calculate separate space- and time-dependent velocities for each of the participating components. In the limiting case of a vapor explosion, this framework allows calculation of the pre-mixing phase of film boiling and interpenetration of the working fluid by hot liquid, which is required for extrapolating from experiments to a reactor hypothetical accident. Qualitative results are compared favorably to published experimental data where an iron-alumina mixture was poured into water. Differing results are predicted with LMFBR materials
Modelled and Observed Diurnal SST Signals: "SSTDV:R.EX.-IM.A.M." Project Preliminary Results
DEFF Research Database (Denmark)
Karagali, Ioanna; Høyer, Jacob; LeBorgne, Pierre
2013-01-01
This study presents some of the preliminary results from the ESA Support To Science Element (STSE) funded project on the Diurnal Variability of the Sea Surface Temperature, regarding its Regional Extend and Implications in Atmospheric Modelling (SSTDV:R.EX.–IM.A.M.). During this phase of the proj......This study presents some of the preliminary results from the ESA Support To Science Element (STSE) funded project on the Diurnal Variability of the Sea Surface Temperature, regarding its Regional Extend and Implications in Atmospheric Modelling (SSTDV:R.EX.–IM.A.M.). During this phase...
Calculation of the 3D density model of the Earth
Piskarev, A.; Butsenko, V.; Poselov, V.; Savin, V.
2009-04-01
The study of the Earth's crust is a part of investigation aimed at extension of the Russian Federation continental shelf in the Sea of Okhotsk Gathered data allow to consider the Sea of Okhotsk' area located outside the exclusive economic zone of the Russian Federation as the natural continuation of Russian territory. The Sea of Okhotsk is an Epi-Mesozoic platform with Pre-Cenozoic heterogeneous folded basement of polycyclic development and sediment cover mainly composed of Paleocene - Neocene - Quaternary deposits. Results of processing and complex interpretation of seismic, gravity, and aeromagnetic data along profile 2-DV-M, as well as analysis of available geological and geophysical information on the Sea of Okhotsk region, allowed to calculate of the Earth crust model. 4 layers stand out (bottom-up) in structure of the Earth crust: granulite-basic (density 2.90 g/cm3), granite-gneiss (limits of density 2.60-2.76 g/cm3), volcanogenic-sedimentary (2.45 g/cm3) and sedimentary (density 2.10 g/cm3). The last one is absent on the continent; it is observed only on the water area. Density of the upper mantle is taken as 3.30 g/cm3. The observed gravity anomalies are mostly related to the surface relief of the above mentioned layers or to the density variations of the granite-metamorphic basement. So outlining of the basement blocks of different constitution preceded to the modeling. This operation is executed after Double Fourier Spectrum analysis of the gravity and magnetic anomalies and following compilation of the synthetic anomaly maps, related to the basement density and magnetic heterogeneity. According to bathymetry data, the Sea of Okhotsk can be subdivided at three mega-blocks. Taking in consideration that central Sea of Okhotsk area is aseismatic, i.e. isostatic compensated, it is obvious that Earth crust structure of these three blocks is different. The South-Okhotsk depression is characteristics by 3200-3300 m of sea depths. Moho surface in this area is at
Power plant reliability calculation with Markov chain models
International Nuclear Information System (INIS)
Senegacnik, A.; Tuma, M.
1998-01-01
In the paper power plant operation is modelled using continuous time Markov chains with discrete state space. The model is used to compute the power plant reliability and the importance and influence of individual states, as well as the transition probabilities between states. For comparison the model is fitted to data for coal and nuclear power plants recorded over several years. (orig.) [de
Calculation of single chain cellulose elasticity using fully atomistic modeling
Xiawa Wu; Robert J. Moon; Ashlie Martini
2011-01-01
Cellulose nanocrystals, a potential base material for green nanocomposites, are ordered bundles of cellulose chains. The properties of these chains have been studied for many years using atomic-scale modeling. However, model predictions are difficult to interpret because of the significant dependence of predicted properties on model details. The goal of this study is...
Model calculation for energy loss in ion-surface collisions
International Nuclear Information System (INIS)
Miraglia, J.E.; Gravielle, M.S.
2003-01-01
The so-called local plasma approximation is generalized to deal with projectiles colliding with surfaces of amorphous solids and with a specific crystalline structure (plannar channeling). Energy loss of protons grazingly colliding with aluminum, SnTe alloy, and LiF surfaces is investigated. The calculations agree quite well with previous theoretical results and explain the experimental findings of energy loss for aluminum and SnTe alloy, but they fall short to explain the data for LiF surfaces
Energy Technology Data Exchange (ETDEWEB)
Náfrádi, Gábor, E-mail: nafradi@reak.bme.hu [Institute of Nuclear Techniques (NTI), Budapest University of Technology and Economics (BME), H-1111 Budapest (Hungary); Kovácsik, Ákos, E-mail: kovacsik.akos@reak.bme.hu [Institute of Nuclear Techniques (NTI), Budapest University of Technology and Economics (BME), H-1111 Budapest (Hungary); Németh, József, E-mail: nemeth.jozsef@wigner.mta.hu [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics (Wigner RCP), Hungarian Academy of Sciences (HAS), POB 49, 1525 Budapest (Hungary); Pór, Gábor, E-mail: por@reak.bme.hu [Institute of Nuclear Techniques (NTI), Budapest University of Technology and Economics (BME), H-1111 Budapest (Hungary); Zoletnik, Sándor, E-mail: zoletnik.sandor@wigner.mta.hu [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics (Wigner RCP), Hungarian Academy of Sciences (HAS), POB 49, 1525 Budapest (Hungary)
2016-11-15
Monte Carlo N-Particle (MCNP) calculations were carried out to compare neutron shielding capabilities of three frequently used neutron shielding materials: polyethylene without neutron absorbers, polyethylene with boron absorbers and polyethylene with lithium absorbers, according to Non Ionizing Energy Loss (NIEL). The results of 1D shielding calculations showed that simple neutron moderating materials can provide sufficient and cheap shielding against 2.45 MeV and 14.1 MeV fusion neutrons, in terms of 1 MeV neutron equivalent flux, in silicon targets, which is the most commonly used material of electronic components. Based on these results a new shielding concept is proposed which can be taken into consideration where the reduction of displacement damage is the main goal and the free space available for shielding is limited. Based on this shielding concept detailed 3D calculations were carried out to describe the properties of the neutron shielding of the Beam Emission Spectroscopy (BES) system installed at the EAST tokamak.
International Nuclear Information System (INIS)
Zeng Yu; Zhou Luyi
2010-01-01
Objectives: To compare the difference of the ratio of thyroid radioiodine ( 131 I) uptake calculated by actually measuring counts of the standard radioactive source(method 1) and by computing counts of the standard radioactive source via physic half life of 131 I (method 2). Methods: Two hundred and nine consecutive patients with Graves' Disease were prospectively recruited. The ratio of thyroid 131 I uptake was calculated by two methods at 4 h and 24 h after administration of 1.48 MBq 131 I, respectively. Paired t-test was used to compare the difference between the two methods. Results: The ratio of thyroid 131 I uptake at 4h was (32±16)% and ( 35±10)% (t=1.98, P=0.20), at 24h (72±19)% and (69±24)% ( t=1.49, P=0.23), respectively, by the two methods. Conclusion: To calculate the ratio of thyroid 131 I uptake via the physic half life of the standard radioactive resource is feasible, and can both reduce the risk of ionizing radiation to technical staff and act as verifying method for quality control of thyroid function equipment. (authors)
TEVA-SPOT-GUI - Containing Preliminary Flow Model
U.S. Environmental Protection Agency — This ZIP file contains the developmental, test version of TEVA-SPOT-GUI's Flow Model. The Flow Model is a new, event based water quality algorithm for EPANET. The...
Preliminary Uncorrelated Encounter Model of the National Airspace System
National Research Council Canada - National Science Library
Kochenderfer, M. J; Kuchar, J. K; Espindle, L. P; Gertz, J. L
2008-01-01
...) and which may not be in contact with air traffic control. In response to the need to develop a model of these types of encounters, Lincoln Laboratory undertook an extensive radar data collection and modeling effort...
Model Hamiltonian Calculations of the Nonlinear Polarizabilities of Conjugated Molecules.
Risser, Steven Michael
This dissertation advances the theoretical knowledge of the nonlinear polarizabilities of conjugated molecules. The unifying feature of these molecules is an extended delocalized pi electron structure. The pi electrons dominate the electronic properties of the molecules, allowing prediction of molecular properties based on the treatment of just the pi electrons. Two separate pi electron Hamiltonians are used in the research. The principal Hamiltonian used is the non-interacting single-particle Huckel Hamiltonian, which replaces the Coulomb interaction among the pi electrons with a mean field interaction. The simplification allows for exact solution of the Hamiltonian for large molecules. The second Hamiltonian used for this research is the interacting multi-particle Pariser-Parr-Pople (PPP) Hamiltonian, which retains explicit Coulomb interactions. This limits exact solutions to molecules containing at most eight electrons. The molecular properties being investigated are the linear polarizability, and the second and third order hyperpolarizabilities. The hyperpolarizabilities determine the nonlinear optical response of materials. These molecular parameters are determined by two independent approaches. The results from the Huckel Hamiltonian are obtained through first, second and third order perturbation theory. The results from the PPP Hamiltonian are obtained by including the applied field directly in the Hamiltonian and determining the ground state energy at a series of field strengths. By fitting the energy to a polynomial in field strength, the polarizability and hyperpolarizabilities are determined. The Huckel Hamiltonian is used to calculate the third order hyperpolarizability of polyenes. These calculations were the first to show the average hyperpolarizability of the polyenes to be positive, and also to show the saturation of the hyperpolarizability. Comparison of these Huckel results to those from the PPP Hamiltonian shows the lack of explicit Coulomb
QSAR models for anti-androgenic effect - a preliminary study
DEFF Research Database (Denmark)
Jensen, Gunde Egeskov; Nikolov, Nikolai Georgiev; Wedebye, Eva Bay
2011-01-01
Three modelling systems (MultiCase (R), LeadScope (R) and MDL (R) QSAR) were used for construction of androgenic receptor antagonist models. There were 923-942 chemicals in the training sets. The models were cross-validated (leave-groups-out) with concordances of 77-81%, specificity of 78...... of the model for a particular application, balance of training sets, domain definition, and cut-offs for prediction interpretation should also be taken into account. Different descriptors in the modelling systems are illustrated with hydroxyflutamide and dexamethasone as examples (a non-steroid and a steroid...
Energy Technology Data Exchange (ETDEWEB)
Moeller, M. P.; Urbanik, II, T.; Desrosiers, A. E.
1982-03-01
This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffic flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffic queues. The program also models the distribution of times required by individuals to prepare for an evacuation. In order to test its accuracy, the CLEAR model was used to estimate evacuatlon tlmes for the emergency planning zone surrounding the Beaver Valley Nuclear Power Plant. The Beaver Valley site was selected because evacuation time estimates had previously been prepared by the licensee, Duquesne Light, as well as by the Federal Emergency Management Agency and the Pennsylvania Emergency Management Agency. A lack of documentation prevented a detailed comparison of the estimates based on the CLEAR model and those obtained by Duquesne Light. However, the CLEAR model results compared favorably with the estimates prepared by the other two agencies.
International Nuclear Information System (INIS)
Moeller, M.P.; Desrosiers, A.E.; Urbanik, T. II
1982-03-01
This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffic flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffic queues. The program also models the distribution of times required by individuals to prepare for an evacuation. In order to test its accuracy, the CLEAR model was used to estimate evacuation times for the emergency planning zone surrounding the Beaver Valley Nuclear Power Plant. The Beaver Valley site was selected because evacuation time estimates had previously been prepared by the licensee, Duquesne Light, as well as by the Federal Emergency Management Agency and the Pennsylvania Emergency Management Agency. A lack of documentation prevented a detailed comparison of the estimates based on the CLEAR model and those obtained by Duquesne Light. However, the CLEAR model results compared favorably with the estimates prepared by the other two agencies. (author)
Preliminary results of total kinetic energy modelling for neutron-induced fission
International Nuclear Information System (INIS)
Visan, I.; Giubega, G.; Tudora, A.
2015-01-01
The total kinetic energy as a function of fission fragments mass TKE(A) is an important quantity entering in prompt emission calculations. The experimentally distributions of TKE(A) are referring to a limited number of fission systems and incident energies. In the present paper, a preliminary model for TKE calculation in neutron induced fission system is presented. The range of fission fragments is chosen as in the Point by Point treatment. The model needs as input only mass excesses and deformation parameters taken from available nuclear databases being based on the following approximations: total excitation energy of fully accelerated fission fragments TXE is calculated from energy balance of neutron-induced fission systems as sum of the total excitation energy at scission E*sciss and deformation energy Edef. The deformation energy at scission is given by minimizing the potential energy at the scission configuration. At the scission point, the fission system is described by two spheroidal fragments nearly touching by a pre-scission distance or neck caused by the nuclear forces between fragments. Therefore, the Columbian repulsion depending on neck and, consequently, on the fragments deformation at scission, is essentially in TKE determination. An approximation is made based on the fission modes. For the very symmetric fission, the dominant super long channel is characterized by long distance between fragments leading to low TKE values. Due to magic and double-magic shells closure, the dominant S1 fission mode for pairs with heavy fragment mass AH around 130-134 is characterized by spherical heavy fragment shape and easily deformed light fragment. The nearly spherical shape of the complementary fragments are characterized by minimum distance, and consequently to maximum TKE values. The results obtained for TKE(A) are in good agreement with existing experimental data for many neutron induced fission systems, e.g. ''2''3''3&apos
Environment modelling in near Earth space: Preliminary LDEF results
Coombs, C. R.; Atkinson, D. R.; Wagner, J. D.; Crowell, L. B.; Allbrooks, M.; Watts, A. J.
1992-01-01
Hypervelocity impacts by space debris cause not only local cratering or penetrations, but also cause large areas of damage in coated, painted or laminated surfaces. Features examined in these analyses display interesting morphological characteristics, commonly exhibiting a concentric ringed appearance. Virtually all features greater than 0.2 mm in diameter possess a spall zone in which all of the paint was removed from the aluminum surface. These spall zones vary in size from approximately 2 - 5 crater diameters. The actual craters in the aluminum substrate vary from central pits without raised rims, to morphologies more typical of craters formed in aluminum under hypervelocity laboratory conditions for the larger features. Most features also possess what is referred to as a 'shock zone' as well. These zones vary in size from approximately 1 - 20 crater diameters. In most cases, only the outer-most layer of paint was affected by this impact related phenomenon. Several impacts possess ridge-like structures encircling the area in which this outer-most paint layer was removed. In many ways, such features resemble the lunar impact basins, but on an extremely reduced scale. Overall, there were no noticeable penetrations, bulges or spallation features on the backside of the tray. On Row 12, approximately 85 degrees from the leading edge (RAM direction), there was approximately one impact per 15 cm(exp 2). On the trailing edge, there was approximately one impact per 72 cm(exp 2). Currently, craters on four aluminum experiment trays from Bay E09, directly on the leading edge are being measured and analyzed. Preliminary results have produced more than 2200 craters on approximately 1500 cm(exp 2) - or approximately 1 impact per 0.7 cm(exp 2).
Carbon dioxide fluid-flow modeling and injectivity calculations
Burke, Lauri
2011-01-01
At present, the literature lacks a geologic-based assessment methodology for numerically estimating injectivity, lateral migration, and subsequent long-term containment of supercritical carbon dioxide that has undergone geologic sequestration into subsurface formations. This study provides a method for and quantification of first-order approximations for the time scale of supercritical carbon dioxide lateral migration over a one-kilometer distance through a representative volume of rock. These calculations provide a quantified foundation for estimating injectivity and geologic storage of carbon dioxide.
Downscaling of the global climate model data for the mass balance calculation of mountain glaciers
Directory of Open Access Journals (Sweden)
P. A. Morozova
2017-01-01
Full Text Available In this paper, we consider a hybrid method of downscaling of the GCM‑generated meteorological fields to the characteristic spatial resolution which is usually used for modeling of a single mountain glacier mass balance. The main purpose of the study is to develop a reliable forecasting method to evaluate future state of moun‑ tain glaciation under changing climatic conditions. The method consists of two stages. In the first or dynamical stage, we use results of calculations of the regional numerical model HadRM3P for the Black Sea‑Caspian region with a spatial resolution of 25 km [22]. Initial conditions for the HadRM3P were provided by the GCM devel‑ oped in the Institute of Numerical Mathematics of RAS (INMCM4 [18]. Calculations were carried out for two time periods: the present climate (1971–2000 and climate in the late 21st century (2071–2100 according to the scenario of greenhouse gas emissions RCP 8.5. On the second stage of downscaling, further regionalization is achieved by projecting of RCM‑generated data to the high‑resolution (25 m digital altitude model in a domain enclosing a target glacier. Altitude gradients of the surface air temperature and precipitation were derived from the model data. Further on, both were corrected using data of observations. Incoming shortwave radiation was calculated in the mass balance model separately, taking into account characteristics of the slope, i.e. exposition and shading of each cell. Then, the method was tested for glaciers Marukh (Western Caucasus and Jankuat (Central Caucasus, both for the present‑day and for future climates. At the end of the 21st century, the air tem‑ perature rise predicted for the summer months was calculated to be about 5–6 °C, and the result for the winter to be minus 2–3 °C. Change in annual precipitation is not significant, less than 10%. Increase in the total short‑ wave radiation will be about 5%. These changes will result in the fact that
Quark model calculations of current correlators in the nonperturbative domain
International Nuclear Information System (INIS)
Celenza, L.S.; Shakin, C.M.; Sun, W.D.
1995-01-01
The authors study the vector-isovector current correlator in this work, making use of a generalized Nambu-Jona-Lasinio (NJL) model. In their work, the original NJL model is extended to describe the coupling of the quark-antiquark states to the two-pion continuum. Further, a model for confinement is introduced that is seen to remove the nonphysical cuts that appear in various amplitudes when the quark and antiquark go on mass shell. Quite satisfactory results are obtained for the correlator. The authors also use the correlator to define a T-matrix for confined quarks and discuss a rho-dominance model for that T-matrix. It is also seen that the Bethe-Salpeter equation that determines the rho mass (in the absence of the coupling to the two-pion continuum) has more satisfactory behavior in the generalized model than in the model without confinement. That improved behavior is here related to the absence of the q bar q cut in the basic quark-loop integral of the generalized model. In this model, it is seen how one may work with both quark and hadron degrees of freedom, with only the hadrons appearing as physical particles. 12 refs., 16 figs., 1 tab
Real-time dispersion calculation using the Lagrange model LASAT
International Nuclear Information System (INIS)
Janicke, L.
1987-01-01
The LASAT (Lagrange Simulation of Aerosol Transport) dispersion model demonstrates pollutant transport in the atmosphere by simulating the paths of representative random samples of pollutant particles on the computer as natural as possible. The author demonstrates the generated particle paths and refers to literature for details of the model algorithm. (DG) [de
Long-Term Calculations with Large Air Pollution Models
DEFF Research Database (Denmark)
Ambelas Skjøth, C.; Bastrup-Birk, A.; Brandt, J.
1999-01-01
Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...
Reconstructing Holocene climate using a climate model: Model strategy and preliminary results
Haberkorn, K.; Blender, R.; Lunkeit, F.; Fraedrich, K.
2009-04-01
An Earth system model of intermediate complexity (Planet Simulator; PlaSim) is used to reconstruct Holocene climate based on proxy data. The Planet Simulator is a user friendly general circulation model (GCM) suitable for palaeoclimate research. Its easy handling and the modular structure allow for fast and problem dependent simulations. The spectral model is based on the moist primitive equations conserving momentum, mass, energy and moisture. Besides the atmospheric part, a mixed layer-ocean with sea ice and a land surface with biosphere are included. The present-day climate of PlaSim, based on an AMIP II control-run (T21/10L resolution), shows reasonable agreement with ERA-40 reanalysis data. Combining PlaSim with a socio-technological model (GLUES; DFG priority project INTERDYNAMIK) provides improved knowledge on the shift from hunting-gathering to agropastoral subsistence societies. This is achieved by a data assimilation approach, incorporating proxy time series into PlaSim to initialize palaeoclimate simulations during the Holocene. For this, the following strategy is applied: The sensitivities of the terrestrial PlaSim climate are determined with respect to sea surface temperature (SST) anomalies. Here, the focus is the impact of regionally varying SST both in the tropics and the Northern Hemisphere mid-latitudes. The inverse of these sensitivities is used to determine the SST conditions necessary for the nudging of land and coastal proxy climates. Preliminary results indicate the potential, the uncertainty and the limitations of the method.
International Nuclear Information System (INIS)
Jin, L; Eldib, A; Li, J; Price, R; Ma, C
2015-01-01
Purpose: Uneven nose surfaces and air cavities underneath and the use of bolus present complexity and dose uncertainty when using a single electron energy beam to plan treatments of nose skin with a pencil beam-based planning system. This work demonstrates more accurate dose calculation and more optimal planning using energy and intensity modulated electron radiotherapy (MERT) delivered with a pMLC. Methods: An in-house developed Monte Carlo (MC)-based dose calculation/optimization planning system was employed for treatment planning. Phase space data (6, 9, 12 and 15 MeV) were used as an input source for MC dose calculations for the linac. To reduce the scatter-caused penumbra, a short SSD (61 cm) was used. Our previous work demonstrates good agreement in percentage depth dose and off-axis dose between calculations and film measurement for various field sizes. A MERT plan was generated for treating the nose skin using a patient geometry and a dose volume histogram (DVH) was obtained. The work also shows the comparison of 2D dose distributions between a clinically used conventional single electron energy plan and the MERT plan. Results: The MERT plan resulted in improved target dose coverage as compared to the conventional plan, which demonstrated a target dose deficit at the field edge. The conventional plan showed higher dose normal tissue irradiation underneath the nose skin while the MERT plan resulted in improved conformity and thus reduces normal tissue dose. Conclusion: This preliminary work illustrates that MC-based MERT planning is a promising technique in treating nose skin, not only providing more accurate dose calculation, but also offering an improved target dose coverage and conformity. In addition, this technique may eliminate the necessity of bolus, which often produces dose delivery uncertainty due to the air gaps that may exist between the bolus and skin
A Preliminary Field Test of an Employee Work Passion Model
Zigarmi, Drea; Nimon, Kim; Houson, Dobie; Witt, David; Diehl, Jim
2011-01-01
Four dimensions of a process model for the formulation of employee work passion, derived from Zigarmi, Nimon, Houson, Witt, and Diehl (2009), were tested in a field setting. A total of 447 employees completed questionnaires that assessed the internal elements of the model in a corporate work environment. Data from the measurements of work affect,…
A Preliminary Model of Insider Theft of Intellectual Property
2011-06-01
insider IT sabotage [Moore 2008] [Cappelli 2006]. The primary personality model used in CWB research is the Five Factor Model ( FFM ). The FFM includes... FFM dimensions and CWBs, Salgado found 44 studies conducted between 1990 and 1999 that examine the relationship between the FFM dimensions and deviant
A review of Higgs mass calculations in supersymmetric models
DEFF Research Database (Denmark)
Draper, P.; Rzehak, H.
2016-01-01
The discovery of the Higgs boson is both a milestone achievement for the Standard Model and an exciting probe of new physics beyond the SM. One of the most important properties of the Higgs is its mass, a number that has proven to be highly constraining for models of new physics, particularly those...... related to the electroweak hierarchy problem. Perhaps the most extensively studied examples are supersymmetric models, which, while capable of producing a 125 GeV Higgs boson with SM-like properties, do so in non-generic parts of their parameter spaces. We review the computation of the Higgs mass...
Noise and dose modeling for pediatric CT optimization: preliminary results
International Nuclear Information System (INIS)
Miller Clemente, Rafael A.; Perez Diaz, Marlen; Mora Reyes, Yudel; Rodriguez Garlobo, Maikel; Castillo Salazar, Rafael
2008-01-01
Full text: A Multiple Linear Regression Model was developed to predict noise and dose in computed tomography pediatric imaging for head and abdominal examinations. Relative values of Noise and Volumetric Computed Tomography Dose Index was used to estimate de model respectively. 54 images of physical phantoms were performed. Independent variables considered included: phantom diameter, tube current and kilovolts, x ray beam collimation, reconstruction diameter and equipment's post processing filters. Predicted values show good agreement with measurements, which were better in noise model (R 2 adjusted =0.953) than the dose model (R 2 adjusted =0.744). Tube current, object diameter, beam collimation and reconstruction filter were identified as the most influencing factors in models. (author)
A simple model for calculating air pollution within street canyons
Venegas, Laura E.; Mazzeo, Nicolás A.; Dezzutti, Mariana C.
2014-04-01
This paper introduces the Semi-Empirical Urban Street (SEUS) model. SEUS is a simple mathematical model based on the scaling of air pollution concentration inside street canyons employing the emission rate, the width of the canyon, the dispersive velocity scale and the background concentration. Dispersive velocity scale depends on turbulent motions related to wind and traffic. The parameterisations of these turbulent motions include two dimensionless empirical parameters. Functional forms of these parameters have been obtained from full scale data measured in street canyons at four European cities. The sensitivity of SEUS model is studied analytically. Results show that relative errors in the evaluation of the two dimensionless empirical parameters have less influence on model uncertainties than uncertainties in other input variables. The model estimates NO2 concentrations using a simple photochemistry scheme. SEUS is applied to estimate NOx and NO2 hourly concentrations in an irregular and busy street canyon in the city of Buenos Aires. The statistical evaluation of results shows that there is a good agreement between estimated and observed hourly concentrations (e.g. fractional bias are -10.3% for NOx and +7.8% for NO2). The agreement between the estimated and observed values has also been analysed in terms of its dependence on wind speed and direction. The model shows a better performance for wind speeds >2 m s-1 than for lower wind speeds and for leeward situations than for others. No significant discrepancies have been found between the results of the proposed model and that of a widely used operational dispersion model (OSPM), both using the same input information.
Calculation of the fermionic determinant in the Schwinger model
International Nuclear Information System (INIS)
Dias, S.A.; Linhares, C.A.
1991-01-01
We compute explicitly the fermionic determinant and the effective action for the generalized Schwinger model in two dimensions and compare it with respective results for the particular cases of the Schwinger, chiral Schwinger and axial Schwinger models. The parameters that signal the ambiguity in the regularization scheme fo the determinant are introduced through the point-splitting method. The Wess-Zumino functional is also obtained and compared with the known expressions for the above-mentioned particular cases. (author)
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.
Directory of Open Access Journals (Sweden)
Istvan Farkas
2016-08-01
Full Text Available The aim of this work is to simulate the thermohydraulic consequences of a main steam line break and to compare the obtained results with Rossendorf Coolant Mixing Model (ROCOM 1.1 experimental results. The objective is to utilize data from steady-state mixing experiments and computational fluid dynamics (CFD calculations to determine the flow distribution and the effect of thermal mixing phenomena in the primary loops for the improvement of normal operation conditions and structural integrity assessment of pressurized water reactors. The numerical model of ROCOM was developed using the FLUENT code. The positions of the inlet and outlet boundary conditions and the distribution of detailed velocity/turbulence parameters were determined by preliminary calculations. The temperature fields of transient calculation were averaged in time and compared with time-averaged experimental data. The perforated barrel under the core inlet homogenizes the flow, and therefore, a uniform temperature distribution is formed in the pressure vessel bottom. The calculated and measured values of lowest temperature were equal. The inlet temperature is an essential parameter for safety assessment. The calculation predicts precisely the experimental results at the core inlet central region. CFD results showed a good agreement (both qualitatively and quantitatively with experimental results.
An hydrodynamic model for the calculation of oil spills trajectories
Energy Technology Data Exchange (ETDEWEB)
Paladino, Emilio Ernesto; Maliska, Clovis Raimundo [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Dinamica dos Fluidos Computacionais]. E-mails: emilio@sinmec.ufsc.br; maliska@sinmec.ufsc.br
2000-07-01
The aim of this paper is to present a mathematical model and its numerical treatment to forecast oil spills trajectories in the sea. The knowledge of the trajectory followed by an oil slick spilled on the sea is of fundamental importance in the estimation of potential risks for pipeline and tankers route selection, and in combating the pollution using floating barriers, detergents, etc. In order to estimate these slicks trajectories a new model, based on the mass and momentum conservation equations is presented. The model considers the spreading in the regimes when the inertial and viscous forces counterbalance gravity and takes into account the effects of winds and water currents. The inertial forces are considered for the spreading and the displacement of the oil slick, i.e., is considered its effects on the movement of the mass center of the slick. The mass loss caused by oil evaporation is also taken into account. The numerical model is developed in generalized coordinates, making the model easily applicable to complex coastal geographies. (author)
Uncertain hybrid model for the response calculation of an alternator
International Nuclear Information System (INIS)
Kuczkowiak, Antoine
2014-01-01
The complex structural dynamic behavior of alternator must be well understood in order to insure their reliable and safe operation. The numerical model is however difficult to construct mainly due to the presence of a high level of uncertainty. The objective of this work is to provide decision support tools in order to assess the vibratory levels in operation before to restart the alternator. Based on info-gap theory, a first decision support tool is proposed: the objective here is to assess the robustness of the dynamical response to the uncertain modal model. Based on real data, the calibration of an info-gap model of uncertainty is also proposed in order to enhance its fidelity to reality. Then, the extended constitutive relation error is used to expand identified mode shapes which are used to assess the vibratory levels. The robust expansion process is proposed in order to obtain robust expanded mode shapes to parametric uncertainties. In presence of lack-of knowledge, the trade-off between fidelity-to-data and robustness-to-uncertainties which expresses that robustness improves as fidelity deteriorates is emphasized on an industrial structure by using both reduced order model and surrogate model techniques. (author)
Model for calculation of concentration and load on behalf of accidents with radioactive materials
International Nuclear Information System (INIS)
Janssen, L.A.M.; Heugten, W.H.H. van
1987-04-01
In the project 'Information- and calculation-system for disaster combatment', by order of the Dutch government, a demonstration model has been developed for a diagnosis system for accidents. In this demonstration a model is used to calculate the concentration- and dose-distributions caused by incidental emissions of limited time. This model is described in this report. 4 refs.; 2 figs.; 3 tabs
International Nuclear Information System (INIS)
Hagenson, R.L.; Tai, A.S.; Krakowski, R.A.; Moses, R.W.
1980-01-01
A conceptual DT fusion reactor concept is described that is based upon the dense Z-pinch (DZP). This study emphasizes plasma modeling and the parametric assessment of the reactor energy balance. To this end simple analytic and numerical models have been developed and evaluated. The resulting optimal reactor operating point promises a high-Q, low-yield system of a scale that may allow the use of conventional high-voltage Marx/water-line technology to drive a potentially very small reactor system
A preliminary geodetic data model for geographic information systems
Kelly, K. M.
2009-12-01
Our ability to gather and assimilate integrated data collections from multiple disciplines is important for earth system studies. Moreover, geosciences data collection has increased dramatically, with pervasive networks of observational stations on the ground, in the oceans, in the atmosphere and in space. Contemporary geodetic observations from several space and terrestrial technologies contribute to our knowledge of earth system processes and thus are a valuable source of high accuracy information for many global change studies. Assimilation of these geodetic observations and numerical models into models of weather, climate, oceans, hydrology, ice, and solid Earth processes is an important contribution geodesists can make to the earth science community. Clearly, the geodetic observations and models are fundamental to these contributions. ESRI wishes to provide leadership in the geodetic community to collaboratively build an open, freely available content specification that can be used by anyone to structure and manage geodetic data. This Geodetic Data Model will provide important context for all geographic information. The production of a task-specific geodetic data model involves several steps. The goal of the data model is to provide useful data structures and best practices for each step, making it easier for geodesists to organize their data and metadata in a way that will be useful in their data analyses and to their customers. Built on concepts from the successful Arc Marine data model, we introduce common geodetic data types and summarize the main thematic layers of the Geodetic Data Model. These provide a general framework for envisioning the core feature classes required to represent geodetic data in a geographic information system. Like Arc Marine, the framework is generic to allow users to build workflow or product specific geodetic data models tailored to the specific task(s) at hand. This approach allows integration of the data with other existing
A calculation model for the noise from steel railway bridges
Janssens, M.H.A.; Thompson, D.J.
1996-01-01
The sound level of a train crossing a steel railway bridge is usually about 10 dB higher than on plain track. In the Netherlands there are many such bridges which, for practical reasons, cannot be replaced by more intrinsically quiet concrete bridges. A computational model is described for the
Reactor accident calculation models in use in the Nordic countries
International Nuclear Information System (INIS)
Tveten, U.
1984-01-01
The report relates to a subproject under a Nordic project called ''Large reactor accidents - consequences and mitigating actions''. In the first part of the report short descriptions of the various models are given. A systematic list by subject is then given. In the main body of the report chapter and subchapter headings are by subject. (Auth.)
A calculation model for a HTR core seismic response
International Nuclear Information System (INIS)
Buland, P.; Berriaud, C.; Cebe, E.; Livolant, M.
1975-01-01
The paper presents the experimental results obtained at Saclay on a HTGR core model and comparisons with analytical results. Two series of horizontal tests have been performed on the shaking table VESUVE: sinusoidal test and time history response. Acceleration of graphite blocks, forces on the boundaries, relative displacement of the core and PCRB model, impact velocity of the blocks on the boundaries were recorded. These tests have shown the strongly non-linear dynamic behaviour of the core. The resonant frequency of the core is dependent on the level of the excitation. These phenomena have been explained by a computer code, which is a lumped mass non-linear model. Good correlation between experimental and analytical results was obtained for impact velocities and forces on the boundaries. This comparison has shown that the damping of the core is a critical parameter for the estimation of forces and velocities. Time history displacement at the level of PCRV was reproduced on the shaking table. The analytical model was applied to this excitation and good agreement was obtained for forces and velocities. (orig./HP) [de
Glass viscosity calculation based on a global statistical modelling approach
Energy Technology Data Exchange (ETDEWEB)
Fluegel, Alex
2007-02-01
A global statistical glass viscosity model was developed for predicting the complete viscosity curve, based on more than 2200 composition-property data of silicate glasses from the scientific literature, including soda-lime-silica container and float glasses, TV panel glasses, borosilicate fiber wool and E type glasses, low expansion borosilicate glasses, glasses for nuclear waste vitrification, lead crystal glasses, binary alkali silicates, and various further compositions from over half a century. It is shown that within a measurement series from a specific laboratory the reported viscosity values are often over-estimated at higher temperatures due to alkali and boron oxide evaporation during the measurement and glass preparation, including data by Lakatos et al. (1972) and the recently published High temperature glass melt property database for process modeling by Seward et al. (2005). Similarly, in the glass transition range many experimental data of borosilicate glasses are reported too high due to phase separation effects. The developed global model corrects those errors. The model standard error was 9-17°C, with R^2 = 0.985-0.989. The prediction 95% confidence interval for glass in mass production largely depends on the glass composition of interest, the composition uncertainty, and the viscosity level. New insights in the mixed-alkali effect are provided.
Semiclassical calculation for collision induced dissociation. II. Morse oscillator model
International Nuclear Information System (INIS)
Rusinek, I.; Roberts, R.E.
1978-01-01
A recently developed semiclassical procedure for calculating collision induced dissociation probabilities P/sup diss/ is applied to the collinear collision between a particle and a Morse oscillator diatomic. The particle--diatom interaction is described with a repulsive exponential potential function. P/sup diss/ is reported for a system of three identical particles, as a function of collision energy E/sub t/ and initial vibrational state of the diatomic n 1 . The results are compared with the previously reported values for the collision between a particle and a truncated harmonic oscillator. The two studies show similar features, namely: (a) there is an oscillatory structure in the P/sup diss/ energy profiles, which is directly related to n 1 ; (b) P/sup diss/ becomes noticeable (> or approx. =10 -3 ) for E/sub t/ values appreciably higher than the energetic threshold; (c) vibrational enhancement (inhibition) of collision induced dissociation persists at low (high) energies; and (d) good agreement between the classical and semiclassical results is found above the classical dynamic threshold. Finally, the convergence of P/sup diss/ for increasing box length is shown to be rapid and satisfactory
IEA-ETSAP TIMES models in Denmark. Preliminary edition
Energy Technology Data Exchange (ETDEWEB)
Grohnheit, P.E.
2011-03-15
This report presents the project 'Danish participation in IEAETSAP, Annex XI, 2008-2010', which continued the Danish participation in ETSAP under Annex XI 'JOint STudies for New And Mitigated Energy Systems (JOSTNAMES): Climate friendly, Secure and Productive Energy Systems'. The main activity has been semi-annual workshops focusing on presentations of model analyses and use of the ETSAP tools (the MARKAL/TIMES family of models). Contributions to these workshops have been based on various collaborative projects within the EU research programmes and the Danish Centre for Environment, Energy and Health (CEEH). In addition, the DTU Climate Centre at Risoe, which was founded in the autumn of 2008, has taken part in the ETSAP workshops, and used the ETSAP model tools for projects, papers, and presentations, as well as for a Ph.D. project. (Author)
RHF RELAP5 model and preliminary loss-of-offsite-power simulation results for LEU conversion
Energy Technology Data Exchange (ETDEWEB)
Licht, J. R. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Bergeron, A. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Dionne, B. [Argonne National Laboratory (ANL), Argonne, IL (United States). Nuclear Engineering Div.; Thomas, F. [Institut Laue-Langevin (ILL), Grenoble (Switzerland). RHF Reactor Dept.
2014-08-01
The purpose of this document is to describe the current state of the RELAP5 model for the Institut Laue-Langevin High Flux Reactor (RHF) located in Grenoble, France, and provide an update to the key information required to complete, for example, simulations for a loss of offsite power (LOOP) accident. A previous status report identified a list of 22 items to be resolved in order to complete the RELAP5 model. Most of these items have been resolved by ANL and the RHF team. Enough information was available to perform preliminary safety analyses and define the key items that are still required. Section 2 of this document describes the RELAP5 model of RHF. The final part of this section briefly summarizes previous model issues and resolutions. Section 3 of this document describes preliminary LOOP simulations for both HEU and LEU fuel at beginning of cycle conditions.
Business Model Innovation in European SMEs: some preliminary findings
Bouwman, W.A.G.A.; Molina Castillo, F.J.; de Reuver, G.A.
2016-01-01
Business Models have been on the research agenda since the emergence of ecommerce and ebusiness in late last century. Although a lot of attention has been paid to the concept, ontologies, taxonomies and approach in the field of strategic management, information systems, digital business and
Approximate models for neutral particle transport calculations in ducts
International Nuclear Information System (INIS)
Ono, Shizuca
2000-01-01
The problem of neutral particle transport in evacuated ducts of arbitrary, but axially uniform, cross-sectional geometry and isotropic reflection at the wall is studied. The model makes use of basis functions to represent the transverse and azimuthal dependences of the particle angular flux in the duct. For the approximation in terms of two basis functions, an improvement in the method is implemented by decomposing the problem into uncollided and collided components. A new quadrature set, more suitable to the problem, is developed and generated by one of the techniques of the constructive theory of orthogonal polynomials. The approximation in terms of three basis functions is developed and implemented to improve the precision of the results. For both models of two and three basis functions, the energy dependence of the problem is introduced through the multigroup formalism. The results of sample problems are compared to literature results and to results of the Monte Carlo code, MCNP. (author)
Aeroelastic Calculations Using CFD for a Typical Business Jet Model
Gibbons, Michael D.
1996-01-01
Two time-accurate Computational Fluid Dynamics (CFD) codes were used to compute several flutter points for a typical business jet model. The model consisted of a rigid fuselage with a flexible semispan wing and was tested in the Transonic Dynamics Tunnel at NASA Langley Research Center where experimental flutter data were obtained from M(sub infinity) = 0.628 to M(sub infinity) = 0.888. The computational results were computed using CFD codes based on the inviscid TSD equation (CAP-TSD) and the Euler/Navier-Stokes equations (CFL3D-AE). Comparisons are made between analytical results and with experiment where appropriate. The results presented here show that the Navier-Stokes method is required near the transonic dip due to the strong viscous effects while the TSD and Euler methods used here provide good results at the lower Mach numbers.
Model calculation of the scanned field enhancement factor of CNTs
International Nuclear Information System (INIS)
Ahmad, Amir; Tripathi, V K
2006-01-01
The field enhancement factor of a carbon nanotube (CNT) placed in a cluster of CNTs is smaller than an isolated CNT because the electric field on one tube is screened by neighbouring tubes. This screening depends on the length of the CNTs and the spacing between them. We have derived an expression to compute the field enhancement factor of CNTs under any positional distribution of CNTs using a model of a floating sphere between parallel anode and cathode plates. Using this expression we can compute the field enhancement factor of a CNT in a cluster (non-uniformly distributed CNTs). This expression is used to compute the field enhancement factor of a CNT in an array (uniformly distributed CNTs). Comparison has been shown with experimental results and existing models
Quark model calculation of charmed baryon production by neutrinos
International Nuclear Information System (INIS)
Avilez, C.; Kobayashi, T.; Koerner, J.G.
1976-11-01
We study the neutrino production of 25 low-lying charmed baryon resonances in the four flavour quark model. The mass difference of ordinary and charmed quarks is explicitly taken into account. The quark model is used to determine the spectrum of the charmed baryon resonances and the q 2 = 0 values of the weak current transition matrix elements. These transition matrix elements are then continued to space-like q 2 -values by a generalized meson dominance ansatz for a set of suitably chosen invariant form factors. We find that the production of the L = 0 states C 0 , C 1 and C 1 * is dominant, with the C 0 produced most copiously. For L = 1, 2 the Jsup(P) = 3/2 - 5/2 + charm states are dominant. We give differential cross sections, total cross sections and energy integrated total cross sections using experimental neutrino fluxes. (orig./BJ) [de
Preliminary development of the Active Colonoscopy Training Model
Directory of Open Access Journals (Sweden)
Choi J
2011-06-01
Full Text Available JungHun Choi1, Kale Ravindra1, Randolph Robert1, David Drozek21Mechanical Engineering, Ohio University, Athens, OH, USA; 2College of Osteopathic Medicine, Ohio University, Athens, OH, USAAbstract: Formal colonoscopy training requires a significant amount of time and effort. In particular, it requires actual patients for a realistic learning experience. The quality of colonoscopy training varies, and includes didactic courses and procedures proctored by skilled surgeons. A colonoscopy training model is occasionally used as part of the training method, but the effects are minute due to both the simple and tedious training procedures. To enhance the educational effect of the colonoscopy training model, the Active Colonoscopy Training Model (ACTM has been developed. ACTM is an interactive colonoscopy training device which can create the environment of a real colonoscopy procedure as closely as possible. It comprises a configurable rubber colon, a human torso, sensors, a display, and the control part. The ACTM provides audio and visual interaction to the trainee by monitoring important factors, such as forces caused by the distal tip and the shaft of the colonoscope and the pressure to open up the lumen and the localization of the distal tip. On the computer screen, the trainee can easily monitor the status of the colonoscopy, which includes the localization of the distal tip, maximum forces, pressure inside the colon, and surgery time. The forces between the rubber colon and the constraints inside the ACTM are measured and the real time display shows the results to the trainee. The pressure sensors will check the pressure at different parts of the colon. The real-time localized distal tip gives the colonoscopy trainee easier and more confident operation without introducing an additional device in the colonoscope. With the current need for colonoscopists and physicians, the ACTM can play an essential role resolving the problems of the current
International Nuclear Information System (INIS)
McMurry, J.
1995-10-01
In the Environmental Impact Statement (EIS) and the related documents that describe the Canadian nuclear fuel waste disposal concept (AECL 1994), it has been assumed that a disposal vault would have no significant geochemical impact on the geosphere, and so no such effects were included explicitly in the postclosure assessment model. The purpose of this study was to estimate the general magnitude and significance of vault-induced geochemical changes over an expected range of temperatures. The results of the preliminary modelling are used broadly to evaluate the implications of these changes for the migration of radionuclides through the geosphere. The geochemical modelling program PHREEQE was used to calculate the changes in mineral solubilities that would result from the transfer of aqueous species from the vault to the geosphere or that would result from groundwater-granite interactions enhanced by vault-derived elevated temperatures. Twelve representative vault water compositions, derived from predicted interactions with buffer material and backfill over a range of temperatures up to 95 deg C, were used in the modelling. For the conditions modelled it was determined that the interactions of the geosphere with dissolved vault constituents, and the relatively modest maximum increase in groundwater temperature produced by a vault, would have a limited impact on the geosphere. The conclusions of this preliminary study are qualified by some of the simplifying assumptions used in the modelling. More realistic modelling of natural systems requires a more detailed representation of water-solid interactions with a variety of vault materials at elevated temperatures. (author) 48 refs., 13 tabs, 4 figs
Microscopic calculation of parameters of the sdg interacting boson model for 104-110Pd isotopes
International Nuclear Information System (INIS)
Liu Yong
1995-01-01
The parameters of the sdg interacting boson model Hamiltonian are calculated for the 104-110 Pd isotopes. The calculations utilize the microscopic procedure based on the Dyson boson mapping proposed by Yang-Liu-Qi and extended to include the g boson effects. The calculated parameters reproduce those values from the phenomenological fits. The resulting spectra are compared with the experimental spectra
A preliminary model for posttraumatic brain injury depression.
Malec, James F; Brown, Allen W; Moessner, Anne M; Stump, Timothy E; Monahan, Patrick
2010-07-01
To develop, based on previous research, and evaluate a model for depression after traumatic brain injury (TBI). Cross-sectional structural equation modeling (SEM) of data from consecutively recruited patients. Acute hospital and inpatient rehabilitation units. Adult patients (N=158) after hospital admission for moderate to severe TBI. Not applicable. External appraisal of ability in participants was measured by the Mayo-Portland Adaptability Inventory (MPAI-4) Ability Index completed by a TBI clinical nurse specialist. Patient self-appraisal of post-TBI ability and depression were measured by the Awareness Questionnaire and Beck Depression Inventory-II. Functional outcome 1 year after injury was assessed with the MPAI-4 Participation Index. Successive SEM resulted in a parsimonious model with excellent fit. Consistent with prior research, a moderately strong association between self-appraisal of post-TBI ability and depression was found. Injury severity, as measured by the duration of posttraumatic amnesia (PTA), was not significantly associated with post-TBI depression. The 1-year functional outcome was associated with depression and TBI severity. The strong association between self-appraisal of post-TBI ability and depression is consistent with the cognitive-behavioral model of depression and recommends consideration and further study of cognitive-behavioral therapy for post-TBI depression. The lack of association between TBI severity and depression may represent the indirect and proxy nature of current measures of TBI severity such as PTA. Emerging neuroimaging techniques (eg, diffusion tensor imaging, magnetic resonance imaging spectroscopy) may provide the more direct measures of disruption of brain function after TBI that are needed to advance this line of research. Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
A Preliminary Model of Insider Theft of Intellectual Property
2011-01-01
social, and technical factors. We expect future work to use modeling and simulation to identify and evaluate the effectiveness of deterrent measures in...umentation tools and has provided solutions across the energy, consumer business, health care, communications, publishing, manufacturing, media...received his B.A. from Colgate University and his Masters and Ph.D. in Psychology from Duke University. He per- formed a fellowship in Psychology in the
Vascularized anal autotransplantation model in rats: preliminary report.
Araki, J; Mihara, M; Narushima, M; Iida, T; Sato, T; Koshima, I
2011-11-01
Ostomy has served as an effective surgery for various anorectal disfunctions. However, it must also be noted that those patients suffered greatly from stresses caused by their stoma. Many alternative therapies have been developed, but none have solved this critical issue. Meanwhile, due to the improvements in operative methods and immunosuppressive therapy, allotranplantation has gained great popularity in recent years. Therefore, we began development of an anal transplantation model. The operation was performed in six adult Wistar rats that were divided into two groups. Group 1 underwent vascular anastomoses, while group 2 did not Group 1 grafts survived, fully recovering anal function. However, many of the group 2 grafts did not survive; those that did survive showed major defects in their anus, never recovering anal function. We succeeded in establishing the rat anal transplantation model utilizing super-microsurgery. While research in anal transplantation was behind compared to that in other fields, we hope that this model will bring significant possibilities for the future. Copyright © 2011 Elsevier Inc. All rights reserved.
Static model calculation of pion-nucleon scattering
International Nuclear Information System (INIS)
Itoh, Takashi
1975-01-01
The p-wave pion-nucleon scattering phase-shifts are computed by the Chew-Low static model for pion incident energy of 0-300 MeV. The square of the unrenormalized coupling constant is taken to be f 2 =0.2, and the cutoff is made at k sub(max)=6μ. The computed 3,3 phase-shift passes through 90 deg about at the right energy. The other phase-shifts computed are small in rough agreement with experiment. (auth.)
Simplified models for radiational losses calculating a tokamak plasma
International Nuclear Information System (INIS)
Arutiunov, A.B.; Krasheninnikov, S.I.; Prokhorov, D.Yu.
1990-01-01
To determine the magnitudes and profiles of radiational losses in a Tokamak plasma, particularly for high plasma densities, when formation of MARFE or detached-plasma takes place, it is necessary to know impurity distribution over the ionization states. Equations describing time evolution of this distribution are rather cumbersome, besides that, transport coefficients as well as rate constants of the processes involving complex ions are known nowadays with high degree of uncertainty, thus it is believed necessary to develop simplified, half-analytical models describing time evolution of the impurities analysis of physical processes taking place in a Tokamak plasma on the base of the experimental data. (author) 6 refs., 2 figs
Nuclear matter calculations with a pseudoscalar-pseudovector chiral model
Energy Technology Data Exchange (ETDEWEB)
Niembro, R.; Marcos, S.; Bernardos, P. [University of Cantabria, Faculty of Sciences, Department of Modern Physics, 39005 Santander (Spain); Fomenko, V.N. [St Petersburg University for Railway Engineering, Department of Mathematics, 197341 St Petersburg (Russian Federation); Savushkin, L.N. [St Petersburg University for Telecomunications, Department of Physics, 191065 St Petersburg (Russian Federation); Lopez-Quelle, M. [University of Cantabria, Faculty of Sciences, Department of Applied Physics, 39005 Santander, Spain (Spain)
1998-10-01
A mixed pseudoscalar-pseudovector {pi}N coupling relativistic Lagrangian is obtained from a pure pseudoscalar chiral one, by transforming the nucleon field according to a generalized Weinberg transformation, which depends on a mixing parameter. The interaction is generated by the {sigma}, {omega} and {pi} meson exchanges. Within the Hartree-Fock context, pion polarization effects, including the {delta} isobar, are considered in the random phase approximation in nuclear matter. These effects are interpreted, in a non-relativistic framework, as a modification of the range and intensity of a Yukawa-type potential by means of a simple function which takes into account the nucleon-hole and {delta}-hole excitations. Results show stability of relativistic nuclear matter against pion condensation. Compression modulus is diminished by the combined effects of the nucleon and {delta} polarization towards the usually accepted experimental values. The {pi}N interaction strength used in this paper is less than the conventional one to ensure the viability of the model. The fitting parameters of the model are the scalar meson mass m{sub {sigma}} and the {omega}-N coupling constant g{sub {omega}}. (author)
Predictive Modelling Risk Calculators and the Non Dialysis Pathway.
Robins, Jennifer; Katz, Ivor
2013-04-16
This guideline will review the current prediction models and survival/mortality scores available for decision making in patients with advanced kidney disease who are being considered for a non-dialysis treatment pathway. Risk prediction is gaining increasing attention with emerging literature suggesting improved patient outcomes through individualised risk prediction (1). Predictive models help inform the nephrologist and the renal palliative care specialists in their discussions with patients and families about suitability or otherwise of dialysis. Clinical decision making in the care of end stage kidney disease (ESKD) patients on a non-dialysis treatment pathway is currently governed by several observational trials (3). Despite the paucity of evidence based medicine in this field, it is becoming evident that the survival advantages associated with renal replacement therapy in these often elderly patients with multiple co-morbidities and limited functional status may be negated by loss of quality of life (7) (6), further functional decline (5, 8), increased complications and hospitalisations. This article is protected by copyright. All rights reserved.
The curvature calculation mechanism based on simple cell model.
Yu, Haiyang; Fan, Xingyu; Song, Aiqi
2017-07-20
A conclusion has not yet been reached on how exactly the human visual system detects curvature. This paper demonstrates how orientation-selective simple cells can be used to construct curvature-detecting neural units. Through fixed arrangements, multiple plurality cells were constructed to simulate curvature cells with a proportional output to their curvature. In addition, this paper offers a solution to the problem of narrow detection range under fixed resolution by selecting an output value under multiple resolution. Curvature cells can be treated as concrete models of an end-stopped mechanism, and they can be used to further understand "curvature-selective" characteristics and to explain basic psychophysical findings and perceptual phenomena in current studies.
Jamaludin, Amril Hadri; Karim, Nurulzatushima Abdul; Noor, Raja Nor Husna Raja Mohd; Othman, Nurulhidayah; Malik, Sulaiman Abdul
2017-08-01
Construction waste management (CWM) is the practice of minimizing and diverting construction waste, demolition debris, and land-clearing debris from disposal and redirecting recyclable resources back into the construction process. Best practice model means best choice from the collection of other practices that was built for purpose of construction waste management. The practice model can help the contractors in minimizing waste before the construction activities will be started. The importance of minimizing wastage will have direct impact on time, cost and quality of a construction project. This paper is focusing on the preliminary study to determine the factors of waste generation in the construction sites and identify the effectiveness of existing construction waste management practice conducted in Malaysia. The paper will also include the preliminary works of planned research location, data collection method, and analysis to be done by using the Analytical Hierarchy Process (AHP) to help in developing suitable waste management best practice model that can be used in the country.
Preliminary conceptual model for mineral evolution in Yucca Mountain
International Nuclear Information System (INIS)
Duffy, C.J.
1993-12-01
A model is presented for mineral alteration in Yucca Mountain, Nevada, that suggests that the mineral transformations observed there are primarily controlled by the activity of aqueous silica. The rate of these reactions is related to the rate of evolution of the metastable silica polymorphs opal-CT and cristobalite assuming that a SiO 2(aq) is fixed at the equilibrium solubility of the most soluble silica polymorph present. The rate equations accurately predict the present depths of disappearance of opal-CT and cristobalite. The rate equations have also been used to predict the extent of future mineral alteration that may result from emplacement of a high-level nuclear waste repository in Yucca Mountain. Relatively small changes in mineralogy are predicted, but these predictions are based on the assumption that emplacement of a repository would not increase the pH of water in Yucca Mountain nor increase its carbonate content. Such changes may significantly increase mineral alteration. Some of the reactions currently occurring in Yucca Mountain consume H + and CO 3 2- . Combining reaction rate models for these reactions with water chemistry data may make it possible to estimate water flux through the basal vitrophyre of the Topopah Spring Member and to help confirm the direction and rate of flow of groundwater in Yucca Mountain
Preliminary time-phased TWRS process model results
International Nuclear Information System (INIS)
Orme, R.M.
1995-01-01
This report documents the first phase of efforts to model the retrieval and processing of Hanford tank waste within the constraints of an assumed tank farm configuration. This time-phased approach simulates a first try at a retrieval sequence, the batching of waste through retrieval facilities, the batching of retrieved waste through enhanced sludge washing, the batching of liquids through pretreatment and low-level waste (LLW) vitrification, and the batching of pretreated solids through high-level waste (HLW) vitrification. The results reflect the outcome of an assumed retrieval sequence that has not been tailored with respect to accepted measures of performance. The batch data, composition variability, and final waste volume projects in this report should be regarded as tentative. Nevertheless, the results provide interesting insights into time-phased processing of the tank waste. Inspection of the composition variability, for example, suggests modifications to the retrieval sequence that will further improve the uniformity of feed to the vitrification facilities. This model will be a valuable tool for evaluating suggested retrieval sequences and establishing a time-phased processing baseline. An official recommendation on tank retrieval sequence will be made in September, 1995
Energy Technology Data Exchange (ETDEWEB)
Andreani-Aksoyoglu, S; Keller, J [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1999-08-01
In the frame of the comprehensive assessment of Swiss energy systems, air quality simulations were performed by using a 3-dimensional photo-chemical dispersion model. The objective is to investigate the impacts of pollutants in Switzerland for future options of Swiss energy systems. Four scenarios were investigated: Base Case: simulations with the projected emissions for the year 2030, Scenario 1) all nuclear power plants were replaced by oil-driven combined cycle plants (CCP), Scenarios 2 to 4) traffic emissions were reduced in whole Switzerland as well as in the cities and on the highways separately. Changes in the pollutant concentrations and depositions, and the possible short-term impacts are discussed on the basis of exceedences of critical levels for plants and limits given to protect the public health. (author) 2 figs., 7 refs.
Preliminary analysis of a 1:4 scale prestressed concrete containment vessel model
International Nuclear Information System (INIS)
Dameron, R.A.; Rashid, Y.R.; Luk, V.K.; Hessheimer, M.F.
1997-01-01
Sandia National Laboratories is conducting a research program to investigate the integrity of nuclear containment structures. As part of the program Sandia will construct an instrumented 1:4 scale model of a prestressed concrete containment vessel (PCCV) for pressurized water reactors (PWR), which will be pressure tested up to its ultimate capacity. One of the key program objectives is to develop validated methods to predict the structural performance of containment vessels when subjected to beyond design basis loadings. Analytical prediction of structural performance requires a stepwise, systematic approach that addresses all potential failure modes. The analysis effort includes two and three-dimensional nonlinear finite element analyses of the PCCV test model to evaluate its structural performance under very high internal pressurization. Such analyses have been performed using the nonlinear concrete constitutive model, ANACAP-U, in conjunction with the ABAQUS general purpose finite element code. The analysis effort is carried out in three phases: preliminary analysis; pretest prediction; and post-test data interpretation and analysis evaluation. The preliminary analysis phase serves to provide instrumentation support and identify candidate failure modes. The associated tasks include the preliminary prediction of failure pressure and probable failure locations and the development of models to be used in the detailed failure analyses. This paper describes the modeling approaches and some of the results obtained in the first phase of the analysis effort
Dynamic density functional theory of solid tumor growth: Preliminary models
Directory of Open Access Journals (Sweden)
Arnaud Chauviere
2012-03-01
Full Text Available Cancer is a disease that can be seen as a complex system whose dynamics and growth result from nonlinear processes coupled across wide ranges of spatio-temporal scales. The current mathematical modeling literature addresses issues at various scales but the development of theoretical methodologies capable of bridging gaps across scales needs further study. We present a new theoretical framework based on Dynamic Density Functional Theory (DDFT extended, for the first time, to the dynamics of living tissues by accounting for cell density correlations, different cell types, phenotypes and cell birth/death processes, in order to provide a biophysically consistent description of processes across the scales. We present an application of this approach to tumor growth.
User Guide for GoldSim Model to Calculate PA/CA Doses and Limits
International Nuclear Information System (INIS)
Smith, F.
2016-01-01
A model to calculate doses for solid waste disposal at the Savannah River Site (SRS) and corresponding disposal limits has been developed using the GoldSim commercial software. The model implements the dose calculations documented in SRNL-STI-2015-00056, Rev. 0 ''Dose Calculation Methodology and Data for Solid Waste Performance Assessment (PA) and Composite Analysis (CA) at the Savannah River Site''.
User Guide for GoldSim Model to Calculate PA/CA Doses and Limits
Energy Technology Data Exchange (ETDEWEB)
Smith, F. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
2016-10-31
A model to calculate doses for solid waste disposal at the Savannah River Site (SRS) and corresponding disposal limits has been developed using the GoldSim commercial software. The model implements the dose calculations documented in SRNL-STI-2015-00056, Rev. 0 “Dose Calculation Methodology and Data for Solid Waste Performance Assessment (PA) and Composite Analysis (CA) at the Savannah River Site”.
Preliminary results of sup(40)Ca(e,e'c) reaction analysis c p,α, based on statistical model
International Nuclear Information System (INIS)
Herdade, S.B.; Emrich, H.J.
1990-01-01
Statistical model calculations relative to the reactions sup(40)Ca (e,e'p) sup(39)K and sup(40)Ca(e,e'P sub(o)) sup(39)K sup(gs), using a modified version of the program STAPRE are compared with experimental results obtained from coincidence experiments carried out at the Mainz microtron MAMI A. Preliminary results indicate that the statistical decay of a 1 sup(-) level in the sup(40)Ca compound nucleus, at an excitation energy + 20 MeV, to the ground state of the sup(39)K residual nucleus is only about 15% of the total decay, indicating that direct and/or semi-direct mechanisms contribute to the major part of the decay. (author)
A model for calculating expected performance of the Apollo unified S-band (USB) communication system
Schroeder, N. W.
1971-01-01
A model for calculating the expected performance of the Apollo unified S-band (USB) communication system is presented. The general organization of the Apollo USB is described. The mathematical model is reviewed and the computer program for implementation of the calculations is included.
Improvements to the nuclear model code GNASH for cross section calculations at higher energies
International Nuclear Information System (INIS)
Young, P.G.; Chadwick, M.B.
1994-01-01
The nuclear model code GNASH, which in the past has been used predominantly for incident particle energies below 20 MeV, has been modified extensively for calculations at higher energies. The model extensions and improvements are described in this paper, and their significance is illustrated by comparing calculations with experimental data for incident energies up to 160 MeV
Preliminary Modelling of Radiation Levels at the Fermilab PIP-II Linac
Energy Technology Data Exchange (ETDEWEB)
Lari, L. [CERN; Cerutti, F. [CERN; Esposito, L. S. [CERN; Baffes, C. [Fermilab; Dixon, S. J. [Fermilab; Mokhov, N. V. [Fermilab; Rakhno, I. [Fermilab; Tropin, I. S. [Fermilab
2018-04-01
PIP-II is the Fermilab's flagship project for providing powerful, high-intensity proton beams to the laboratory's experiments. The heart of PIP-II is an 800-MeV superconducting linac accelerator. It will be located in a new tunnel with new service buildings and connected to the present Booster through a new transfer line. To support the design of civil engineering and mechanical integration, this paper provides preliminary estimation of radiation level in the gallery at an operational beam loss limit of 0.1 W/m, by means of Monte Carlo calculations with FLUKA and MARS15 codes.
Preliminary Modeling Of Radiation Levels At The Fermilab PIP-II Linac arXiv
Lari, L.; Esposito, L.S.; Baffes, C.; Dixon, S.J.; Mokhov, N.V.; Rakhno, I.; Tropin, I.S.
PIP-II is the Fermilab's flagship project for providing powerful, high-intensity proton beams to the laboratory's experiments. The heart of PIP-II is an 800-MeV superconducting linac accelerator. It will be located in a new tunnel with new service buildings and connected to the present Booster through a new transfer line. To support the design of civil engineering and mechanical integration, this paper provides preliminary estimation of radiation level in the gallery at an operational beam loss limit of 0.1 W/m, by means of Monte Carlo calculations with FLUKA and MARS15 codes.
Cost calculation model concerning small-scale production of chips and split firewood
International Nuclear Information System (INIS)
Ryynaenen, S.; Naett, H.; Valkonen, J.
1995-01-01
The TTS-Institute's Forestry Department has developed a computer-based cost calculation model for the production of wood chips and split firewood. This development work was carried out in conjunction with the nation-wide BIOENERGY -research programme. The said calculation model eases and speeds up the calculation of unit costs and resource needs in harvesting systems for wood chips and split firewood. The model also enables the user to find out how changes in the productivity and costs bases of different harvesting chains influences the unit costs of the system as a whole. The undertaking was composed of the following parts: clarification and modification of productivity bases for application in the model as mathematical models, clarification of machine and device costs bases, designing of the structure and functions of the calculation model, construction and testing of the model's 0-version, model calculations concerning typical chains, review of calculation bases, and charting of development needs focusing on the model. The calculation model was developed to serve research needs, but with further development it could be useful as a tool in forestry and agricultural extension work, related schools and colleges, and in the hands of firewood producers. (author)
Developing ontological model of computational linear algebra - preliminary considerations
Wasielewska, K.; Ganzha, M.; Paprzycki, M.; Lirkov, I.
2013-10-01
The aim of this paper is to propose a method for application of ontologically represented domain knowledge to support Grid users. The work is presented in the context provided by the Agents in Grid system, which aims at development of an agent-semantic infrastructure for efficient resource management in the Grid. Decision support within the system should provide functionality beyond the existing Grid middleware, specifically, help the user to choose optimal algorithm and/or resource to solve a problem from a given domain. The system assists the user in at least two situations. First, for users without in-depth knowledge about the domain, it should help them to select the method and the resource that (together) would best fit the problem to be solved (and match the available resources). Second, if the user explicitly indicates the method and the resource configuration, it should "verify" if her choice is consistent with the expert recommendations (encapsulated in the knowledge base). Furthermore, one of the goals is to simplify the use of the selected resource to execute the job; i.e., provide a user-friendly method of submitting jobs, without required technical knowledge about the Grid middleware. To achieve the mentioned goals, an adaptable method of expert knowledge representation for the decision support system has to be implemented. The selected approach is to utilize ontologies and semantic data processing, supported by multicriterial decision making. As a starting point, an area of computational linear algebra was selected to be modeled, however, the paper presents a general approach that shall be easily extendable to other domains.
Development of the model for the stress calculation of fuel assembly under accident load
International Nuclear Information System (INIS)
Kim, Il Kon
1993-01-01
The finite element model for the stress calculation in guide thimbles of a fuel assembly (FA) under seismic and loss-of-coolant-accident (LOCA) load is developed. For the stress calculation of FA under accident load, at first the program MAIN is developed to select the worst bending mode shaped FA from core model. And then the model for the stress calculation of FA is developed by means of the finite element code. The calculated results of program MAIN are used as the kinematic constraints of the finite element model of a FA. Compared the calculated results of the stiffness of the finite element model of FA with the test results they have good agreements. (Author)
Sammour, T; Cohen, L; Karunatillake, A I; Lewis, M; Lawrence, M J; Hunter, A; Moore, J W; Thomas, M L
2017-11-01
Recently published data support the use of a web-based risk calculator ( www.anastomoticleak.com ) for the prediction of anastomotic leak after colectomy. The aim of this study was to externally validate this calculator on a larger dataset. Consecutive adult patients undergoing elective or emergency colectomy for colon cancer at a single institution over a 9-year period were identified using the Binational Colorectal Cancer Audit database. Patients with a rectosigmoid cancer, an R2 resection, or a diverting ostomy were excluded. The primary outcome was anastomotic leak within 90 days as defined by previously published criteria. Area under receiver operating characteristic curve (AUROC) was derived and compared with that of the American College of Surgeons National Surgical Quality Improvement Program ® (ACS NSQIP) calculator and the colon leakage score (CLS) calculator for left colectomy. Commercially available artificial intelligence-based analytics software was used to further interrogate the prediction algorithm. A total of 626 patients were identified. Four hundred and fifty-six patients met the inclusion criteria, and 402 had complete data available for all the calculator variables (126 had a left colectomy). Laparoscopic surgery was performed in 39.6% and emergency surgery in 14.7%. The anastomotic leak rate was 7.2%, with 31.0% requiring reoperation. The anastomoticleak.com calculator was significantly predictive of leak and performed better than the ACS NSQIP calculator (AUROC 0.73 vs 0.58) and the CLS calculator (AUROC 0.96 vs 0.80) for left colectomy. Artificial intelligence-predictive analysis supported these findings and identified an improved prediction model. The anastomotic leak risk calculator is significantly predictive of anastomotic leak after colon cancer resection. Wider investigation of artificial intelligence-based analytics for risk prediction is warranted.
Kuss, DJ; Shorter, GW; Van Rooij, AJ; Griffiths, MD; Schoenmakers, T
2014-01-01
Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffiths’ addiction components (2005), i...
Directory of Open Access Journals (Sweden)
Darya Sergeevna Simonenkova
2013-09-01
Full Text Available The subject of the research is analysis of various models of the information system constructed with the use of technologies of cloud calculations. Analysis of models is required for constructing a new reference model which will be used for develop a security threats model.
Implementation of the neutronics model of HEXTRAN/HEXBU-3D into APROS for WWER calculations
International Nuclear Information System (INIS)
Rintala, J.
2008-01-01
A new three-dimensional nodal model for neutronics calculation is currently under implementation into APROS - Advanced PROcess Simulation environment - to conform the increasing accuracy requirements. The new model is based on an advanced nodal code HEXTRAN and its static version HEXBU-3D by VTT, Technical Research Centre of Finland. Currently the new APROS is under a testing programme. Later a systematic validation will be performed. In the first phase, a goal is to obtain a fully validated model for VVER-440 calculations. Thus, all the current test calculations are performed by using Loviisa NPP's VVER-440 model of APROS. In future, the model is planned to be applied for the calculations of VVER-1000 type reactors as well as in rectangular fuel geometry. The paper outlines first the general aspects of the method, and then the current situation of the implementation. Because of the identical model with the models of HEXTRAN and HEXBU-3D, the results in the test calculations are compared to the results of those. In the paper, results of two static test calculations are shown. Currently the model works well already in static analyses. Only minor problems with the control assemblies of VVER-440 type reactor still exist but the reasons are known and will be corrected in near future. Dynamical characteristics of the model are up to now tested only by some empirical tests. (author)
International Nuclear Information System (INIS)
Caggiano, J.A.
1982-03-01
Preliminary data on strain rate, seismicity, and estimated earthquake source parameters suggest limitations on the extent of postulated faulting and its impact on a nuclear waste repository in Columbia River basalt. Structural relief of dated basalt flows, attitude of Pliocene sediments, geodetic surveys, size and distribution of earthquakes, and focal mechanism solutions indicate that deformation of basalt under north-south compression was under way in the Miocene and has continued on existing structures at an average rate of much less than 1 mm/yr in the Pasco Basin. Lengths and displacements of mapped faults suggest limits on the postulated fault that could intersect a repository and produce an earthquake of about magnitude 6.5. Using a credible earthquake permits calculation of preliminary source parameters for risk assessment modeling during a single episode of slip on the postulated new fault and indicates displacement of less than or equal to 1, m on a steeply dipping fault of less than or equal to 50 km length could occur. Preliminary source parameter calculations suggest that displacements of less than or equal to 2 cm may occur during microearthquakes in swarms. The area of fault rupture may be tens of square meters up to a few square kilometers, suggesting slip on joints. Seismic moments for postulated earthquakes in the interconnecting fault and microearthquake scenarios compare favorably with reported values for similar-sized earthquakes in different media and suggest that the estimated fault parameters are reasonable until an adequate tectonic model has been developed
Biologically Inspired Visual Model With Preliminary Cognition and Active Attention Adjustment.
Qiao, Hong; Xi, Xuanyang; Li, Yinlin; Wu, Wei; Li, Fengfu
2015-11-01
Recently, many computational models have been proposed to simulate visual cognition process. For example, the hierarchical Max-Pooling (HMAX) model was proposed according to the hierarchical and bottom-up structure of V1 to V4 in the ventral pathway of primate visual cortex, which could achieve position- and scale-tolerant recognition. In our previous work, we have introduced memory and association into the HMAX model to simulate visual cognition process. In this paper, we improve our theoretical framework by mimicking a more elaborate structure and function of the primate visual cortex. We will mainly focus on the new formation of memory and association in visual processing under different circumstances as well as preliminary cognition and active adjustment in the inferior temporal cortex, which are absent in the HMAX model. The main contributions of this paper are: 1) in the memory and association part, we apply deep convolutional neural networks to extract various episodic features of the objects since people use different features for object recognition. Moreover, to achieve a fast and robust recognition in the retrieval and association process, different types of features are stored in separated clusters and the feature binding of the same object is stimulated in a loop discharge manner and 2) in the preliminary cognition and active adjustment part, we introduce preliminary cognition to classify different types of objects since distinct neural circuits in a human brain are used for identification of various types of objects. Furthermore, active cognition adjustment of occlusion and orientation is implemented to the model to mimic the top-down effect in human cognition process. Finally, our model is evaluated on two face databases CAS-PEAL-R1 and AR. The results demonstrate that our model exhibits its efficiency on visual recognition process with much lower memory storage requirement and a better performance compared with the traditional purely computational
Calculation of DC Arc Plasma Torch Voltage- Current Characteristics Based on Steebeck Model
International Nuclear Information System (INIS)
Gnedenko, V.G.; Ivanov, A.A.; Pereslavtsev, A.V.; Tresviatsky, S.S.
2006-01-01
The work is devoted to the problem of the determination of plasma torches parameters and power sources parameters (working voltage and current of plasma torch) at the predesigning stage. The sequence of calculation of voltage-current characteristics of DC arc plasma torch is proposed. It is shown that the simple Steenbeck model of arc discharge in cylindrical channel makes it possible to carry out this calculation. The results of the calculation are confirmed by the experiments
International Nuclear Information System (INIS)
Gasco, C.; Anton, M. P.; Ampudia, J.
2003-01-01
The introduction of macros in try calculation sheets allows the automatic application of various dating models using unsupported ''210 Pb data from a data base. The calculation books the contain the models have been modified to permit the implementation of these macros. The Marine and Aquatic Radioecology group of CIEMAT (MARG) will be involved in new European Projects, thus new models have been developed. This report contains a detailed description of: a) the new implement macros b) the design of a dating Menu in the calculation sheet and c) organization and structure of the data base. (Author) 4 refs
Optimization of the neutron calculation model for the RA-6 reactor
International Nuclear Information System (INIS)
Coscia, G.A.
1981-01-01
A model for the neutronic calculation of the RA-6 reactor which includes the codes ANISN and EQUIPOSE is analyzed. Starting with a brief description of the reactor, the core and its parts, the general scheme of calculation applied is presented. The fuel elements used were those which are utilized in the RA-3 reactor; this is of the MTR type with 90% enriched uranium. With the approximations used, an analysis of such model of calculation was made, trying to optimize it by reducing, if possible, the calculation time without loosing accuracy. In order to improve the calculation model, it is recomended a cross section data library specific for the enrichment of the fuel considered 90% and the incorporation of a more advanced code than EQUIPOISE which would be DIXYBAR. (M.E.L.) [es
Energy Technology Data Exchange (ETDEWEB)
Zhang, Zhen [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Xia, Changliang [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Yan, Yan, E-mail: yanyan@tju.edu.cn [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China); Geng, Qiang [Tianjin Engineering Center of Electric Machine System Design and Control, Tianjin 300387 (China); Shi, Tingna [School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072 (China)
2017-08-01
Highlights: • A hybrid analytical model is developed for field calculation of multilayer IPM machines. • The rotor magnetic field is calculated by the magnetic equivalent circuit method. • The field in the stator and air-gap is calculated by subdomain technique. • The magnetic scalar potential on rotor surface is modeled as trapezoidal distribution. - Abstract: Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff’s law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell’s equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.
A preliminary three-dimensional geological framework model for Yucca Mountain
International Nuclear Information System (INIS)
Stirewalt, G.L.; Henderson, D.B.
1995-01-01
A preliminary three-dimensional geological framework model has been developed for the potential high-level radioactive waste disposal site at Yucca Mountain. The model is based on field data and was constructed using EarthVision (Version 2.0) software. It provides the basic geological framework in which variations in geological parameters and features in and adjacent to the repository block can be illustrated and analyzed. With further refinement and modification of the model through incorporation of additional data, it can be used by Nuclear Regulatory Commission (NRC) staff to determine whether representation of subsurface geological features in Department of Energy models is reasonable. Consequently, NRC staff will be able to use the model during pre-licensing and licensing phases to assess models for analyses of site suitability, design considerations, and repository performance
Energy Technology Data Exchange (ETDEWEB)
Druce, C.H.; Barrett, B.R. (Arizona Univ., Tucson (USA). Dept. of Physics); Pittel, S. (Delaware Univ., Newark (USA). Bartol Research Foundation); Duval, P.D. (BEERS Associates, Reston, VA (USA))
1985-07-11
The parameters of the Majorana interaction of the neutron-proton interacting boson model are calculated for the Hg isotopes. The calculations utilize the Otsuka-Arima-Iachello mapping procedure and also lead to predictions for the other boson parameters. The resulting spectra are compared with experimental spectra and those obtained from phenomenological fits.
Druce, C. H.; Pittel, S.; Barrett, B. R.; Duval, P. D.
1985-07-01
The parameters of the Majorana interaction of the neutron-proton interacting boson model are calculated for the Hg isotopes. The calculations utilize the Otsuka-Arima-Iachello mapping procedure and also lead to predictions for the other boson parameters. The resulting spectra are compared with experimental spectra and those obtained from phenomenological fits.
A preliminary concept of stochastic model of the tritium cycle in a fusion reactor
International Nuclear Information System (INIS)
Taczanowski, S.
1988-01-01
A preliminary concept of stochastic model of the tritium circulation in a fusion reactor was elaborated in purpose of determining the necessary minimum and current tritium inventory in real circumstances. A random character of reactor operation was assumed what is especially valid in the starting phase being of particularly low reliability of the assembly. A system of differential equations with random initial conditions describing the tritium cycle was solved for both operation and break states of the reactor. The distribution of the moments and of the number of breaks in the reactor operation was discussed and the possibilities of further development of the present model are indicated. 5 refs., 2 figs. (author)
International Nuclear Information System (INIS)
Perry, K.E. Jr.; Buescher, B.J.; Anderson, D.; Epstein, J.S.
1995-09-01
An important aspect of determining the suitability of Yucca Mountain as a possible nuclear waste repository requires understanding the mechanical behavior of jointed rock-masses. To this end we have studied the frictional sliding between simulated rock joints in the laboratory using the technique of phase shifting moire interferometry. The models were made from stacks of Lexan plates and contained a central hole to induce slip between the plates when the models were loaded in compression. These preliminary results confirm the feasibility of the approach and show a clear evolution of slip as function of load
The effect of magnetic field models on cosmic ray cutoff calculations
International Nuclear Information System (INIS)
Pfitzer, K.A.
1979-01-01
The inaccuracies in the 1974 Olson-Pfitzer model appeared to be the probable cause for discrepancies between the observed and calculated cosmic ray cutoff values. An improved version of the Olson-Pfitzer model is now available which includes the effects of the tilt of the earth's dipole axis and which has removed most of the problems encountered in the earlier model. The paper demonstrates that when this new accurate magnetic field model is used, the calculated and observed cutoff values agree with the experimental error without the need for invoking anomalous diffusion mechanisms. This tilt-dependent model also permits a study of cutoffs versus the tilt of the dipole axis
Developing a Model of Tuition Fee Calculation for Universities of Medical Sciences
Directory of Open Access Journals (Sweden)
Seyed Amir Mohsen Ziaee
2018-01-01
Full Text Available Background: The aim of our study was to introduce and evaluate a practicable model for tuition fee calculation of each medical field in universities of medical sciences in Iran.Methods: Fifty experts in 11 panels were interviewed to identify variables that affect tuition fee calculation. This led to key points including total budgets, expenses of the universities, different fields’ attractiveness, universities’ attractiveness, and education quality. Tuition fees were calculated for different levels of education, such as post-diploma, Bachelor, Master, and Doctor of Philosophy (Ph.D degrees, Medical specialty, and Fellowship. After tuition fee calculation, the model was tested during 2013-2015. Since then, a questionnaire including 20 questions was prepared. All Universities’ financial and educational managers were asked to respond to the questions regarding the model’s reliability and effectiveness.Results: According to the results, fields’ attractiveness, universities’ attractiveness, zone distinction and education quality were selected as effective variables for tuition fee calculation. In this model, tuition fees per student were calculated for the year 2013, and, therefore, the inflation rate of the same year was used. Testing of the model showed that there is a 92% of satisfaction. This model is used by medical science universities in Iran.Conclusion: Education quality, zone coefficient, fields’ attractiveness, universities’ attractiveness, inflation rate, and portion of each level of education were the most important variables affecting tuition fee calculation.Keywords: TUITION FEES, FIELD’S ATTRACTIVENESS, UNIVERSITIES’ ATTRACTIVENESS, ZONE DISTINCTION, EDUCATION QUALITY
International Nuclear Information System (INIS)
Ward, D.B.; Bryan, C.R.
1994-01-01
An experiment involving migration of fluid and tracers (Li, Br, Ni) through a 6-m-high x 3-m-dia caisson Wedron 510 sand, is being carried out for Yucca Mountain Site Characterization Project. Sand's surface chemistry of the sand was studied and a preliminary surface-complexation model of Ni adsorption formulated for transport calculations. XPS and leaching suggest that surface of the quartz sand is partially covered by thin layers of Fe-oxyhydroxide and Ca-Mg carbonate and by flakes of kaolinite. Ni adsorption by the sand is strongly pH-dependent, showing no adsorption at pH 5 and near-total adsorption at pH 7. Location of adsorption edge is independent of ionic strength and dissolved Ni concentration; it is shifted to slightly lower pH with higher pCO2 and to slightly higher pH by competition with Li. Diminished adsorption at alkiline pH with higher pCO2 implies formation of dissolved Ni-carbonato complexes. Ni adsorption edges for goethite and quartz, two components of the sand were also measured. Ni adsorption on pure quartz is only moderately pH-dependent and differs in shape and location from that of the sand, whereas Ni adsorption by goethite is strongly pH-dependent. A triple-layer surface-complexation model developed for goethite provides a good fit to the Ni-adsorption curve of the sand. Based on this model, the apparent surface area of the Fe-oxyhydroxide coating is estimated to be 560 m 2 /g, compatible with its occurrence as amorphous Fe-oxyhydroxide. Potentiometric titrations on sand also differ from pure quartz and suggest that effective surface area of sand may be much greater than that measured by N 2 -BET gas adsorption. Attempts to model the adsorption of bulk sand in terms of properties of pure end member components suggest that much of the sand surface is inert. Although the exact Ni adsorption mechanisms remain ambiguous, this preliminary adsorption model provides an initial set of parameters that can be used in transport calculations
Strip yielding model for calculation of COD in spheres with short cracks
International Nuclear Information System (INIS)
Miller, A.G.
1981-08-01
The crack opening displacement at the centre of a crack in a sphere with internal pressure has been calculated, using a strip yielding model. The results have been displayed for a range of geometrical parameters and loads. (author)
The contribution of Skyrme Hartree-Fock calculations to the understanding of the shell model
International Nuclear Information System (INIS)
Zamick, L.
1984-01-01
The authors present a detailed comparison of Skyrme Hartree-Fock and the shell model. The H-F calculations are sensitive to the parameters that are chosen. The H-F results justify the use of effective charges in restricted model space calculations by showing that the core contribution can be large. Further, the H-F results roughly justify the use of a constant E2 effective charge, but seem to yield nucleus dependent E4 effective charges. The H-F can yield results for E6 and higher multipoles, which would be zero in s-d model space calculations. On the other side of the coin in H-F the authors can easily consider only the lowest rotational band, whereas in the shell model one can calculate the energies and properties of many more states. In the comparison some apparent problems remain, in particular E4 transitions in the upper half of the s-d shell
Modeling for Dose Rate Calculation of the External Exposure to Gamma Emitters in Soil
International Nuclear Information System (INIS)
Allam, K. A.; El-Mongy, S. A.; El-Tahawy, M. S.; Mohsen, M. A.
2004-01-01
Based on the model proposed and developed in Ph.D thesis of the first author of this work, the dose rate conversion factors (absorbed dose rate in air per specific activity of soil in nGy.hr - 1 per Bq.kg - 1) are calculated 1 m above the ground for photon emitters of natural radionuclides uniformly distributed in the soil. This new and simple dose rate calculation software was used for calculation of the dose rate in air 1 m above the ground. Then the results were compared with those obtained by five different groups. Although the developed model is extremely simple, the obtained results of calculations, based on this model, show excellent agreement with those obtained by the above-mentioned models specially that one adopted by UNSCEAR. (authors)
Chiral Lagrangian calculation of nucleon branching ratios in the supersymmetric SU(5) model
International Nuclear Information System (INIS)
Chadha, S.; Daniel, M.
1983-12-01
The branching ratios are calculated for the two body nucleon decay modes involving pseudoscalars in the minimal SU(5) supersymmetric model with three generations using the techniques of chiral dynamics. (author)
The transition equation of the state intensities for exciton model and the calculation program
International Nuclear Information System (INIS)
Yu Xian; Zheng Jiwen; Liu Guoxing; Chen Keliang
1995-01-01
An equation set of the exciton model is given and calculation program is developed. The process of approaching to equilibrium state has been investigated with the program for 12 C + 64 Ni reaction at energy 72 MeV
Fast and accurate calculation of dilute quantum gas using Uehling–Uhlenbeck model equation
Energy Technology Data Exchange (ETDEWEB)
Yano, Ryosuke, E-mail: ryosuke.yano@tokiorisk.co.jp
2017-02-01
The Uehling–Uhlenbeck (U–U) model equation is studied for the fast and accurate calculation of a dilute quantum gas. In particular, the direct simulation Monte Carlo (DSMC) method is used to solve the U–U model equation. DSMC analysis based on the U–U model equation is expected to enable the thermalization to be accurately obtained using a small number of sample particles and the dilute quantum gas dynamics to be calculated in a practical time. Finally, the applicability of DSMC analysis based on the U–U model equation to the fast and accurate calculation of a dilute quantum gas is confirmed by calculating the viscosity coefficient of a Bose gas on the basis of the Green–Kubo expression and the shock layer of a dilute Bose gas around a cylinder.
NUCORE - A system for nuclear structure calculations with cluster-core models
International Nuclear Information System (INIS)
Heras, C.A.; Abecasis, S.M.
1982-01-01
Calculation of nuclear energy levels and their electromagnetic properties, modelling the nucleus as a cluster of a few particles and/or holes interacting with a core which in turn is modelled as a quadrupole vibrator (cluster-phonon model). The members of the cluster interact via quadrupole-quadrupole and pairing forces. (orig.)
Thermodynamic modeling of the Sc-Zn system coupled with first-principles calculation
Directory of Open Access Journals (Sweden)
Tang C.
2012-01-01
Full Text Available The Sc-Zn system has been critically reviewed and assessed by means of CALPHAD (CALculation of PHAse Diagram approach. By means of first-principles calculation, the enthalpies of formation at 0 K for the ScZn, ScZn2, Sc17Zn58, Sc3Zn17 and ScZn12 have been computed with the desire to assist thermodynamic modeling. A set of self-consistent thermodynamic parameters for the Sc-Zn system is then obtained. The calculated phase diagram and thermodynamic properties agree well with the experimental data and first-principles calculations, respectively.
On thermal vibration effects in diffusion model calculations of blocking dips
International Nuclear Information System (INIS)
Fuschini, E.; Ugozzoni, A.
1983-01-01
In the framework of the diffusion model, a method for calculating blocking dips is suggested that takes into account thermal vibrations of the crystal lattice. Results of calculations of the diffusion factor and the transverse energy distribution taking into accoUnt scattering of the channeled particles at thermal vibrations of lattice nuclei, are presented. Calculations are performed for α-particles with the energy of 2.12 MeV at 300 K scattered by Al crystal. It is shown that calculations performed according to the above method prove the necessity of taking into account effects of multiple scattering under blocking conditions
Heterogeneous neutron-leakage model for PWR pin-by-pin calculation
International Nuclear Information System (INIS)
Li, Yunzhao; Zhang, Bin; Wu, Hongchun; Shen, Wei
2017-01-01
Highlights: •The derivation of the formula of the leakage model is introduced. This paper evaluates homogeneous and heterogeneous leakage models used in PWR pin-by-pin calculation. •The implements of homogeneous and heterogeneous leakage models used in pin-cell homogenization of the lattice calculation are studied. A consistent method of cooperation between the heterogeneous leakage model and the pin-cell homogenization theory is proposed. •Considering the computational cost, a new buckling search scheme is proposed to reach the convergence faster. The computational cost of the newly proposed neutron balance scheme is much less than the power-method scheme and the linear-interpolation scheme. -- Abstract: When assembly calculation is performed with the reflective boundary condition, a leakage model is usually required in the lattice code. The previous studies show that the homogeneous leakage model works effectively for the assembly homogenization. However, it becomes different and unsettled for the pin-cell homogenization. Thus, this paper evaluates homogeneous and heterogeneous leakage models used in pin-by-pin calculation. The implements of homogeneous and heterogeneous leakage models used in pin-cell homogenization of the lattice calculation are studied. A consistent method of cooperation between the heterogeneous leakage model and the pin-cell homogenization theory is proposed. Considering the computational cost, a new buckling search scheme is proposed to reach the convergence faster. For practical reactor-core applications, the diffusion coefficients determined by the transport cross-section or by the leakage model are compared with each other to determine which one is more accurate for the Pressurized Water Reactor pin-by-pin calculation. Numerical results have demonstrated that the heterogeneous leakage model together with the diffusion coefficient determined by the heterogeneous leakage model would have the higher accuracy. The new buckling search
DEFF Research Database (Denmark)
Yuan, Hao; You, Zhenjiang; Shapiro, Alexander
2013-01-01
Colloidal-suspension flow in porous media is modelled simultaneously by the large scale population balance equations and by the microscale network model. The phenomenological parameter of the correlation length in the population balance model is determined from the network modelling. It is found...... out that the correlation length in the population balance model depends on the particle size. This dependency calculated by two-dimensional network has the same tendency as that obtained from the laboratory tests in engineered porous media....
International Nuclear Information System (INIS)
Abbate, P.
1990-01-01
The CONVEC program developed for the thermohydraulic calculation under a natural convection regime for MTR type reactors is presented. The program is based on a stationary, one dimensional model of finite differences that allow to calculate the temperatures of cooler, cladding and fuel as well as the flow for a power level specified by the user. This model has been satisfactorily validated by a water cooling (liquid phase) and air system. (Author) [es
CASIM calculations and angular dependent parameter β in the Moyer model
International Nuclear Information System (INIS)
Yamaguchi, Chiri.
1988-04-01
The dose equivalent on the shield surface has been calculated using both the Moyer model and the Monte Carlo code CASIM. Calculations with various values of the angular distribution parameter β in the Moyer model show that β = 7.0 ± 0.5 would meet the CASIM results at most, especially regarding locations at which the values of the maximum dose equivalent occur. (author)
International Nuclear Information System (INIS)
Laureau, Axel
2015-01-01
In this PhD thesis, we describe the development of innovative neutronic models for their coupling with thermal hydraulics such that they combine precision and reasonable computational times. One of the main cases where this method is applied is the Molten Salt Fast Reactor (MSFR) whose combines a fast neutron spectrum with a thorium cycle. In this fourth generation reactor, the motion of the delayed neutron precursors and the associated phenomena have to be taken into account due to the liquid fuel circulation. The starting point for these developments was the preliminary design of this type of system where a dedicated multi-physical representation was needed to study the reactor performance in steady and transient conditions. As a first step, a stationary coupling was developed. A neutronic model based on a stochastic approach was associated to a CFD (Computational Fluid Dynamics) code to solve the Navier Stokes equations for turbulent flows and the transport of the delayed neutron precursors. The impact of this precursor motion is taken into account by reconstructing the prompt shower that they generate. This approach, called by shower, views the critical reactor as a prompt subcritical reactor that amplifies a source of delayed neutrons. A second step consisted in developing a neutronic model based on a time dependent version of the fission matrices (Transient Fission Matrix or TFM) so as to enable reactor transient studies. With the TFM model, an initial computation of the matrices with a stochastic code (MCNP, SERPENT) allows the characterization of the global spatial and time dependent neutronic response of the reactor with a precision close to that of a Monte Carlo calculation. The information thus obtained is then used to calculate transients, while retaining the advantage of reduced computational time. The TFM model, which can be used for various system concepts, also allows the evaluation of effective kinetic parameters such as the effective fraction of
Energy Technology Data Exchange (ETDEWEB)
Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin (AquaBiota Water Research, Stockholm (SE))
2007-06-15
GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All
International Nuclear Information System (INIS)
Carlen, Ida; Nikolopoulos, Anna; Isaeus, Martin
2007-06-01
GIS grids (maps) of marine parameters were created using point data from previous site investigations in the Forsmark and Oskarshamn areas. The proportion of global radiation reaching the sea bottom in Forsmark and Oskarshamn was calculated in ArcView, using Secchi depth measurements and the digital elevation models for the respective area. The number of days per year when the incoming light exceeds 5 MJ/m2 at the bottom was then calculated using the result of the previous calculations together with measured global radiation. Existing modelled grid-point data on bottom and pelagic temperature for Forsmark were interpolated to create surface covering grids. Bottom and pelagic temperature grids for Oskarshamn were calculated using point measurements to achieve yearly averages for a few points and then using regressions with existing grids to create new maps. Phytoplankton primary production in Forsmark was calculated using point measurements of chlorophyll and irradiance, and a regression with a modelled grid of Secchi depth. Distribution of biomass of macrophyte communities in Forsmark and Oskarshamn was calculated using spatial modelling in GRASP, based on field data from previous surveys. Physical parameters such as those described above were used as predictor variables. Distribution of biomass of different functional groups of fish in Forsmark was calculated using spatial modelling based on previous surveys and with predictor variables such as physical parameters and results from macrophyte modelling. All results are presented as maps in the report. The quality of the modelled predictions varies as a consequence of the quality and amount of the input data, the ecology and knowledge of the predicted phenomena, and by the modelling technique used. A substantial part of the variation is not described by the models, which should be expected for biological modelling. Therefore, the resulting grids should be used with caution and with this uncertainty kept in mind. All
Zhang, Zhen; Xia, Changliang; Yan, Yan; Geng, Qiang; Shi, Tingna
2017-08-01
Due to the complicated rotor structure and nonlinear saturation of rotor bridges, it is difficult to build a fast and accurate analytical field calculation model for multilayer interior permanent magnet (IPM) machines. In this paper, a hybrid analytical model suitable for the open-circuit field calculation of multilayer IPM machines is proposed by coupling the magnetic equivalent circuit (MEC) method and the subdomain technique. In the proposed analytical model, the rotor magnetic field is calculated by the MEC method based on the Kirchhoff's law, while the field in the stator slot, slot opening and air-gap is calculated by subdomain technique based on the Maxwell's equation. To solve the whole field distribution of the multilayer IPM machines, the coupled boundary conditions on the rotor surface are deduced for the coupling of the rotor MEC and the analytical field distribution of the stator slot, slot opening and air-gap. The hybrid analytical model can be used to calculate the open-circuit air-gap field distribution, back electromotive force (EMF) and cogging torque of multilayer IPM machines. Compared with finite element analysis (FEA), it has the advantages of faster modeling, less computation source occupying and shorter time consuming, and meanwhile achieves the approximate accuracy. The analytical model is helpful and applicable for the open-circuit field calculation of multilayer IPM machines with any size and pole/slot number combination.
Comparison study on models for calculation of NPP’s levelized unit electricity cost
International Nuclear Information System (INIS)
Nuryanti; Mochamad Nasrullah; Suparman
2014-01-01
Economic analysis that is generally done through the calculation of Levelized Unit Electricity Cost (LUEC) is crucial to be done prior to any investment decision on the nuclear power plant (NPP) project. There are several models that can be used to calculate LUEC, which are: R&D PT. PLN (Persero) Model, Mini G4ECONS model and Levelized Cost model. This study aimed to perform a comparison between the three models. Comparison technique was done by tracking the similarity used for each model and then given a case of LUEC calculation for SMR NPP 2 x 100 MW using these models. The result showed that the R&D PT. PLN (Persero) Model have a common principle with Mini G4ECONS model, which use Capital Recovery Factor (CRF) to discount the investment cost which eventually become annuity value along the life of plant. LUEC on both models is calculated by dividing the sum of the annual investment cost and the cost for operating NPP with an annual electricity production.While Levelized Cost model based on the annual cash flow. Total of annual costs and annual electricity production were discounted to the first year of construction in order to obtain the total discounted annual cost and the total discounted energy generation. LUEC was obtained by dividing both of the discounted values. LUEC calculations on the three models produce LUEC value, which are: 14.5942 cents US$/kWh for R&D PT. PLN (Persero) Model, 15.056 cents US$/kWh for Mini G4ECONs model and 14.240 cents US$/kWh for Levelized Cost model. (author)
Nuclear model calculations below 200 MeV and evaluation prospects
International Nuclear Information System (INIS)
Koning, A.J.; Bersillon, O.; Delaroche, J.P.
1994-08-01
A computational method is outlined for the quantum-mechanical prediction of the whole double-differential energy spectrum. Cross sections as calculated with the code system MINGUS are presented for (n,xn) and (p,xn) reactions on 208 Pb and 209 Bi. Our approach involves a dispersive optical model, comprehensive discrete state calculations, renormalized particle-hole state densities, a combined MSD/MSC model for pre-equilibrium reactions and compound nucleus calculations. The relation with the evaluation of nuclear data files is discussed. (orig.)
Thermal-hydraulic feedback model to calculate the neutronic cross-section in PWR reactions
International Nuclear Information System (INIS)
Santiago, Daniela Maiolino Norberto
2011-01-01
In neutronic codes,it is important to have a thermal-hydraulic feedback module. This module calculates the thermal-hydraulic feedback of the fuel, that feeds the neutronic cross sections. In the neutronic co de developed at PEN / COPPE / UFRJ, the fuel temperature is obtained through an empirical model. This work presents a physical model to calculate this temperature. We used the finite volume technique of discretized the equation of temperature distribution, while calculation the moderator coefficient of heat transfer, was carried out using the ASME table, and using some of their routines to our program. The model allows one to calculate an average radial temperature per node, since the thermal-hydraulic feedback must follow the conditions imposed by the neutronic code. The results were compared with to the empirical model. Our results show that for the fuel elements near periphery, the empirical model overestimates the temperature in the fuel, as compared to our model, which may indicate that the physical model is more appropriate to calculate the thermal-hydraulic feedback temperatures. The proposed model was validated by the neutronic simulator developed in the PEN / COPPE / UFRJ for analysis of PWR reactors. (author)
An investigation of fission models for high-energy radiation transport calculations
International Nuclear Information System (INIS)
Armstrong, T.W.; Cloth, P.; Filges, D.; Neef, R.D.
1983-07-01
An investigation of high-energy fission models for use in the HETC code has been made. The validation work has been directed checking the accuracy of the high-energy radiation transport computer code HETC to investigate the appropriate model for routine calculations, particularly for spallation neutron source applications. Model calculations are given in terms of neutron production, fission fragment energy release, and residual nuclei production for high-energy protons incident on thin uranium targets. The effect of the fission models on neutron production from thick uranium targets is also shown. (orig.)
International Nuclear Information System (INIS)
Thykier-Nielsen, S.
1980-07-01
A brief description is given of the model used at Risoe for calculating the consequences of releases of radioactive material to the atmosphere. The model is based on the Gaussian plume model, and it provides possibilities for calculation of: doses to individuals, collective doses, contamination of the ground, probability distribution of doses, and the consequences of doses for give dose-risk relationships. The model is implemented as a computer program PLUCON2, written in ALGOL for the Burroughs B6700 computer at Risoe. A short description of PLUCON2 is given. (author)
Energy Technology Data Exchange (ETDEWEB)
Yoon, Jihyung; Jung, Jae Won, E-mail: jungj@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States); Kim, Jong Oh [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States); Yeo, Inhwan [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354 (United States)
2016-05-15
Purpose: To develop and evaluate a fast Monte Carlo (MC) dose calculation model of electronic portal imaging device (EPID) based on its effective atomic number modeling in the XVMC code. Methods: A previously developed EPID model, based on the XVMC code by density scaling of EPID structures, was modified by additionally considering effective atomic number (Z{sub eff}) of each structure and adopting a phase space file from the EGSnrc code. The model was tested under various homogeneous and heterogeneous phantoms and field sizes by comparing the calculations in the model with measurements in EPID. In order to better evaluate the model, the performance of the XVMC code was separately tested by comparing calculated dose to water with ion chamber (IC) array measurement in the plane of EPID. Results: In the EPID plane, calculated dose to water by the code showed agreement with IC measurements within 1.8%. The difference was averaged across the in-field regions of the acquired profiles for all field sizes and phantoms. The maximum point difference was 2.8%, affected by proximity of the maximum points to penumbra and MC noise. The EPID model showed agreement with measured EPID images within 1.3%. The maximum point difference was 1.9%. The difference dropped from the higher value of the code by employing the calibration that is dependent on field sizes and thicknesses for the conversion of calculated images to measured images. Thanks to the Z{sub eff} correction, the EPID model showed a linear trend of the calibration factors unlike those of the density-only-scaled model. The phase space file from the EGSnrc code sharpened penumbra profiles significantly, improving agreement of calculated profiles with measured profiles. Conclusions: Demonstrating high accuracy, the EPID model with the associated calibration system may be used for in vivo dosimetry of radiation therapy. Through this study, a MC model of EPID has been developed, and their performance has been rigorously
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...
Morris, Ralph E; McNally, Dennis E; Tesche, Thomas W; Tonnesen, Gail; Boylan, James W; Brewer, Patricia
2005-11-01
The Visibility Improvement State and Tribal Association of the Southeast (VISTAS) is one of five Regional Planning Organizations that is charged with the management of haze, visibility, and other regional air quality issues in the United States. The VISTAS Phase I work effort modeled three episodes (January 2002, July 1999, and July 2001) to identify the optimal model configuration(s) to be used for the 2002 annual modeling in Phase II. Using model configurations recommended in the Phase I analysis, 2002 annual meteorological (Mesoscale Meterological Model [MM5]), emissions (Sparse Matrix Operator Kernal Emissions [SMOKE]), and air quality (Community Multiscale Air Quality [CMAQ]) simulations were performed on a 36-km grid covering the continental United States and a 12-km grid covering the Eastern United States. Model estimates were then compared against observations. This paper presents the results of the preliminary CMAQ model performance evaluation for the initial 2002 annual base case simulation. Model performance is presented for the Eastern United States using speciated fine particle concentration and wet deposition measurements from several monitoring networks. Initial results indicate fairly good performance for sulfate with fractional bias values generally within +/-20%. Nitrate is overestimated in the winter by approximately +50% and underestimated in the summer by more than -100%. Organic carbon exhibits a large summer underestimation bias of approximately -100% with much improved performance seen in the winter with a bias near zero. Performance for elemental carbon is reasonable with fractional bias values within +/- 40%. Other fine particulate (soil) and coarse particular matter exhibit large (80-150%) overestimation in the winter but improved performance in the summer. The preliminary 2002 CMAQ runs identified several areas of enhancements to improve model performance, including revised temporal allocation factors for ammonia emissions to improve
Comparison of results of experimental research with numerical calculations of a model one-sided seal
Directory of Open Access Journals (Sweden)
Joachimiak Damian
2015-06-01
Full Text Available Paper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+ has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.
Formation of decontamination cost calculation model for severe accident consequence assessment
International Nuclear Information System (INIS)
Silva, Kampanart; Promping, Jiraporn; Okamoto, Koji; Ishiwatari, Yuki
2014-01-01
In previous studies, the authors developed an index “cost per severe accident” to perform a severe accident consequence assessment that can cover various kinds of accident consequences, namely health effects, economic, social and environmental impacts. Though decontamination cost was identified as a major component, it was taken into account using simple and conservative assumptions, which make it difficult to have further discussions. The decontamination cost calculation model was therefore reconsidered. 99 parameters were selected to take into account all decontamination-related issues, and the decontamination cost calculation model was formed. The distributions of all parameters were determined. A sensitivity analysis using the Morris method was performed in order to identify important parameters that have large influence on the cost per severe accident and large extent of interactions with other parameters. We identified 25 important parameters, and fixed most negligible parameters to the median of their distributions to form a simplified decontamination cost calculation model. Calculations of cost per severe accident with the full model (all parameters distributed), and with the simplified model were performed and compared. The differences of the cost per severe accident and its components were not significant, which ensure the validity of the simplified model. The simplified model is used to perform a full scope calculation of the cost per severe accident and compared with the previous study. The decontamination cost increased its importance significantly. (author)
Comparison of a semi-empirical method with some model codes for gamma-ray spectrum calculation
Energy Technology Data Exchange (ETDEWEB)
Sheng, Fan; Zhixiang, Zhao [Chinese Nuclear Data Center, Beijing, BJ (China)
1996-06-01
Gamma-ray spectra calculated by a semi-empirical method are compared with those calculated by the model codes such as GNASH, TNG, UNF and NDCP-1. The results of the calculations are discussed. (2 tabs., 3 figs.).
International Nuclear Information System (INIS)
Bencik, M.; Hadek, J.
2011-01-01
The paper gives a brief survey of the seventh three-dimensional AER dynamic benchmark calculation results received with the codes DYN3D and RELAP5-3D at Nuclear Research Institute Rez. This benchmark was defined at the twentieth AER Symposium in Hanassari (Finland). It is focused on investigation of transient behaviour in a WWER-440 nuclear power plant. Its initiating event is opening of the main isolation valve and re-connection of the loop with its main circulation pump in operation. The WWER-440 plant is at the end of the first fuel cycle and in hot full power conditions. Stationary and burnup calculations were performed with the code DYN3D. Transient calculation was made with the system code RELAP5-3D. The two-group homogenized cross sections library HELGD05 created by HELIOS code was used for the generation of reactor core neutronic parameters. The detailed six loops model of NPP Dukovany was adopted for the seventh AER dynamic benchmark purposes. The RELAP5-3D full core neutronic model was coupled with 49 core thermal-hydraulic channels and 8 reflector channels connected with the three-dimensional model of the reactor vessel. The detailed nodalization of reactor downcomer, lower and upper plenum was used. Mixing in lower and upper plenum was simulated. The first part of paper contains a brief characteristic of RELAP5-3D system code and a short description of NPP input deck and reactor core model. The second part shows the time dependencies of important global and local parameters. (Authors)
International Nuclear Information System (INIS)
Kljenak, I.; Mavko, B.; Babic, M.
2005-01-01
Full text of publication follows: The modelling and simulation of atmosphere mixing and stratification in nuclear power plant containments is a topic, which is currently being intensely investigated. With the increase of computer power, it has now become possible to model these phenomena with a local instantaneous description, using so-called Computational Fluid Dynamics (CFD) codes. However, calculations with these codes still take relatively long times. An alternative faster approach, which is also being applied, is to model nonhomogeneous atmosphere with lumped-parameter codes by dividing larger control volumes into smaller volumes, in which conditions are modelled as homogeneous. The flow between smaller volumes is modelled using one-dimensional approaches, which includes the prescription of flow loss coefficients. However, some authors have questioned this approach, as it appears that atmosphere stratification may sometimes be well simulated only by adjusting flow loss coefficients to adequate 'artificial' values that are case-dependent. To start the resolution of this issue, a modelling of nonhomogeneous atmosphere with a lumped-parameter code is proposed, where the subdivision of a large volume into smaller volumes is based on results of CFD simulations. The basic idea is to use the results of a CFD simulation to define regions, in which the flow velocities have roughly the same direction. These regions are then modelled as control volumes in a lumped-parameter model. In the proposed work, this procedure was applied to a simulation of an experiment of atmosphere mixing and stratification, which was performed in the TOSQAN facility. The facility is located at the Institut de Radioprotection et de Surete Nucleaire (IRSN) in Saclay (France) and consists of a cylindrical vessel (volume: 7 m3), in which gases are injected. In the experiment, which was also proposed for the OECD/NEA International Standard Problem No.47, air was initially present in the vessel, and
Energy Technology Data Exchange (ETDEWEB)
Nguyen, Son (ed.) [Canadian Nuclear Safety Commission (Canada); Lanru Jing (ed.) [Royal Institute of Technology, Stockholm (Sweden); Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Chijimatzu, Masakazu [Hazama Corporation (Japan); Jussila, Petri [Helsinki Univ. of Technology, Helsinki (Finland); Rutqvist, Jonny [Lawrence Berkeley National Laboratory CA (United States)
2007-02-15
The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the
International Nuclear Information System (INIS)
Nguyen, Son; Lanru Jing; Boergesson, Lennart; Chijimatzu, Masakazu; Jussila, Petri; Rutqvist, Jonny
2007-02-01
The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the container
International Nuclear Information System (INIS)
Anantatmula, R.P.
1984-01-01
A preliminary sensitivity analysis was performed for the corrosion models developed for Basalt Waste Isolation Project container materials. The models describe corrosion behavior of the candidate container materials (low carbon steel and Fe9Cr1Mo), in various environments that are expected in the vicinity of the waste package, by separate equations. The present sensitivity analysis yields an uncertainty in total uniform corrosion on the basis of assumed uncertainties in the parameters comprising the corrosion equations. Based on the sample scenario and the preliminary corrosion models, the uncertainty in total uniform corrosion of low carbon steel and Fe9Cr1Mo for the 1000 yr containment period are 20% and 15%, respectively. For containment periods ≥ 1000 yr, the uncertainty in corrosion during the post-closure aqueous periods controls the uncertainty in total uniform corrosion for both low carbon steel and Fe9Cr1Mo. The key parameters controlling the corrosion behavior of candidate container materials are temperature, radiation, groundwater species, etc. Tests are planned in the Basalt Waste Isolation Project containment materials test program to determine in detail the sensitivity of corrosion to these parameters. We also plan to expand the sensitivity analysis to include sensitivity coefficients and other parameters in future studies. 6 refs., 3 figs., 9 tabs
Parker, L. N.; Zank, G. P.
2013-12-01
Successful forecasting of energetic particle events in space weather models require algorithms for correctly predicting the spectrum of ions accelerated from a background population of charged particles. We present preliminary results from a model that diffusively accelerates particles at multiple shocks. Our basic approach is related to box models (Protheroe and Stanev, 1998; Moraal and Axford, 1983; Ball and Kirk, 1992; Drury et al., 1999) in which a distribution of particles is diffusively accelerated inside the box while simultaneously experiencing decompression through adiabatic expansion and losses from the convection and diffusion of particles outside the box (Melrose and Pope, 1993; Zank et al., 2000). We adiabatically decompress the accelerated particle distribution between each shock by either the method explored in Melrose and Pope (1993) and Pope and Melrose (1994) or by the approach set forth in Zank et al. (2000) where we solve the transport equation by a method analogous to operator splitting. The second method incorporates the additional loss terms of convection and diffusion and allows for the use of a variable time between shocks. We use a maximum injection energy (Emax) appropriate for quasi-parallel and quasi-perpendicular shocks (Zank et al., 2000, 2006; Dosch and Shalchi, 2010) and provide a preliminary application of the diffusive acceleration of particles by multiple shocks with frequencies appropriate for solar maximum (i.e., a non-Markovian process).
A musculoskeletal lumbar and thoracic model for calculation of joint kinetics in the spine
International Nuclear Information System (INIS)
Kim, Yong Cheol; Ta, Duc manh; Koo, Seung Bum; Jung Moon Ki
2016-01-01
The objective of this study was to develop a musculoskeletal spine model that allows relative movements in the thoracic spine for calculation of intra-discal forces in the lumbar and thoracic spine. The thoracic part of the spine model was composed of vertebrae and ribs connected with mechanical joints similar to anatomical joints. Three different muscle groups around the thoracic spine were inserted, along with eight muscle groups around the lumbar spine in the original model from AnyBody. The model was tested using joint kinematics data obtained from two normal subjects during spine flexion and extension, axial rotation and lateral bending motions beginning from a standing posture. Intra-discal forces between spine segments were calculated in a musculoskeletal simulation. The force at the L4-L5 joint was chosen to validate the model's prediction against the lumbar model in the original AnyBody model, which was previously validated against clinical data.
A musculoskeletal lumbar and thoracic model for calculation of joint kinetics in the spine
Energy Technology Data Exchange (ETDEWEB)
Kim, Yong Cheol; Ta, Duc manh; Koo, Seung Bum [Chung-Ang University, Seoul (Korea, Republic of); Jung Moon Ki [AnyBody Technology A/S, Aalborg (Denmark)
2016-06-15
The objective of this study was to develop a musculoskeletal spine model that allows relative movements in the thoracic spine for calculation of intra-discal forces in the lumbar and thoracic spine. The thoracic part of the spine model was composed of vertebrae and ribs connected with mechanical joints similar to anatomical joints. Three different muscle groups around the thoracic spine were inserted, along with eight muscle groups around the lumbar spine in the original model from AnyBody. The model was tested using joint kinematics data obtained from two normal subjects during spine flexion and extension, axial rotation and lateral bending motions beginning from a standing posture. Intra-discal forces between spine segments were calculated in a musculoskeletal simulation. The force at the L4-L5 joint was chosen to validate the model's prediction against the lumbar model in the original AnyBody model, which was previously validated against clinical data.
Rosenzweig, C.
2011-12-01
The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a distributed climate-scenario simulation exercise for historical model intercomparison and future climate change conditions with participation of multiple crop and agricultural trade modeling groups around the world. The goals of AgMIP are to improve substantially the characterization of risk of hunger and world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Recent progress and the current status of AgMIP will be presented, highlighting three areas of activity: preliminary results from crop pilot studies, outcomes from regional workshops, and emerging scientific challenges. AgMIP crop modeling efforts are being led by pilot studies, which have been established for wheat, maize, rice, and sugarcane. These crop-specific initiatives have proven instrumental in testing and contributing to AgMIP protocols, as well as creating preliminary results for aggregation and input to agricultural trade models. Regional workshops are being held to encourage collaborations and set research activities in motion for key agricultural areas. The first of these workshops was hosted by Embrapa and UNICAMP and held in Campinas, Brazil. Outcomes from this meeting have informed crop modeling research activities within South America, AgMIP protocols, and future regional workshops. Several scientific challenges have emerged and are currently being addressed by AgMIP researchers. Areas of particular interest include geospatial weather generation, ensemble methods for climate scenarios and crop models, spatial aggregation of field-scale yields to regional and global production, and characterization of future changes in climate variability.
Directory of Open Access Journals (Sweden)
M. Ridolfi
2014-12-01
Full Text Available We review the main factors driving the calculation of the tangent height of spaceborne limb measurements: the ray-tracing method, the refractive index model and the assumed atmosphere. We find that commonly used ray tracing and refraction models are very accurate, at least in the mid-infrared. The factor with largest effect in the tangent height calculation is the assumed atmosphere. Using a climatological model in place of the real atmosphere may cause tangent height errors up to ± 200 m. Depending on the adopted retrieval scheme, these errors may have a significant impact on the derived profiles.
Power Loss Calculation and Thermal Modelling for a Three Phase Inverter Drive System
Directory of Open Access Journals (Sweden)
Z. Zhou
2005-12-01
Full Text Available Power losses calculation and thermal modelling for a three-phase inverter power system is presented in this paper. Aiming a long real time thermal simulation, an accurate average power losses calculation based on PWM reconstruction technique is proposed. For carrying out the thermal simulation, a compact thermal model for a three-phase inverter power module is built. The thermal interference of adjacent heat sources is analysed using 3D thermal simulation. The proposed model can provide accurate power losses with a large simulation time-step and suitable for a long real time thermal simulation for a three phase inverter drive system for hybrid vehicle applications.
International Nuclear Information System (INIS)
Oliveira, A.C.J.G. de; Andrade Lima, F.R. de
1989-01-01
The present work is an application of the perturbation theory (Matricial formalism) to a simplified two channels model, for sensitivity calculations in PWR cores. Expressions for some sensitivity coefficients of thermohydraulic interest were developed from the proposed model. The code CASNUR.FOR was written in FORTRAN to evaluate these sensitivity coefficients. The comparison between results obtained from the matrical formalism of pertubation theory with those obtained directly from the two channels model, makes evident the efficiency and potentiality of this perturbation method for nuclear reactor cores sensitivity calculations. (author) [pt
Model calculations of excitation functions of neutron-induced reactions on Rh
International Nuclear Information System (INIS)
Strohmaier, Brigitte
1995-01-01
Cross sections of neutron-induced reactions on 103 Rh have been calculated by means of the statistical model and the coupled-channels optical model for incident-neutron energies up to 30 MeV. The incentive for this study was a new measurement of the 103 Rh(n, n') 103m Rh cross section which will - together with the present calculations -enter into a dosimetry-reaction evaluation. The validation of the model parameters relied on nuclear-structure data as far as possible. (author)
A conceptual and calculational model for gas formation from impure calcined plutonium oxides
International Nuclear Information System (INIS)
Lyman, John L.; Eller, P. Gary
2000-01-01
Safe transport and storage of pure and impure plutonium oxides requires an understanding of processes that may generate or consume gases in a confined storage vessel. We have formulated conceptual and calculational models for gas formation from calcined materials. The conceptual model for impure calcined plutonium oxides is based on the data collected to date
3D Printing of Molecular Models with Calculated Geometries and p Orbital Isosurfaces
Carroll, Felix A.; Blauch, David N.
2017-01-01
3D printing was used to prepare models of the calculated geometries of unsaturated organic structures. Incorporation of p orbital isosurfaces into the models enables students in introductory organic chemistry courses to have hands-on experience with the concept of orbital alignment in strained and unstrained p systems.
Model calculations on LIS. II1. 2-, 3- and 7-substituted indanones
International Nuclear Information System (INIS)
Hofer, O.
1979-01-01
The space close to the coordination site of 1-indanone is modified systematically by placing alkyl groups of different bulkiness on C-2, C-3 and C-7, resp. The 1 H-LIS for the compounds are interpreted using the one site and two site model for carbonyl. Precautionary measures are discussed for both models to give reliable results in the calculation. (author)
MONNIE 2000: A description of a model to calculate environmental costs
International Nuclear Information System (INIS)
Hanemaaijer, A.H.; Kirkx, M.C.A.P.
2001-02-01
A new model (MONNIE 2000) was developed by the RIVM in the Netherlands in 2000 to calculate environmental costs on a macro level. The model, it's theoretical backgrounds and the technical aspects are described, making it attractive to both the user and the designer of the model. A user manual on how to calculate with the model is included. The basic principle of the model is the use of a harmonised method for calculating environmental costs, which provides the user with an output that can easily be compared with and used in other economic statistics and macro-economic models in the Netherlands. Input for the model are yearly figures on operational costs, investments and savings from environmental measures. With MONNIE 2000 calculated environmental costs per policy target group, economic sector and theme can be shown, With this model the burden of environmental measures on the economic sectors and the environmental expenditures of the government can be presented as well. MONNIE 2000 is developed in Visual Basic and by using Excel as input and output a user-friendly data exchange is realised. 12 refs
Inclusion of temperature dependence of fission barriers in statistical model calculations
International Nuclear Information System (INIS)
Newton, J.O.; Popescu, D.G.; Leigh, J.R.
1990-08-01
The temperature dependence of fission barriers has been interpolated from the results of recent theoretical calculations and included in the statistical model code PACE2. It is shown that the inclusion of temperature dependence causes significant changes to the values of the statistical model parameters deduced from fits to experimental data. 21 refs., 2 figs
On the applicability of nearly free electron model for resistivity calculations in liquid metals
International Nuclear Information System (INIS)
Gorecki, J.; Popielawski, J.
1982-09-01
The calculations of resistivity based on the nearly free electron model are presented for many noble and transition liquid metals. The triple ion correlation is included in resistivity formula according to SCQCA approximation. Two different methods for describing the conduction band are used. The problem of applicability of the nearly free electron model for different metals is discussed. (author)
A simple model for calculating the bulk modulus of the mixed ionic ...
Indian Academy of Sciences (India)
thermophysical properties, viz., bulk modulus, molecular force constant, reststrahlen fre- quency and Debye temperature using the three-body potential model. The calculated bulk modulus, from the TBPM model, for the pure end members (NH4Cl and NH4Br) are in agreement with the experimental values, as shown in ...
Validation of a model for calculating environmental doses caused by gamma emitters in the soil
International Nuclear Information System (INIS)
Ortega, X.; Rosell, J.R.; Dies, X.
1991-01-01
A model has been developed to calculate the absorbed dose rates caused by gamma emitters of both natural and artificial origin distributed in the soil. The model divides the soil into five compartments corresponding to layers situated at different depths, and assumes that the concentration of radionuclides is constant in each one of them. The calculations, following the model developed, are undertaken through a program which, based on the concentrations of the radionuclides in the different compartments, gives as a result the dose rate at a height of one metre above the ground caused by each radionuclide and the percentage this represents with respect to the total absorbed dose rate originating from this soil. The validity of the model has been checked in the case of sandy soils by comparing the exposure rates calculated for five sites with the experimental values obtained with an ionisation chamber. (author)
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.
Recommendations on dose buildup factors used in models for calculating gamma doses for a plume
International Nuclear Information System (INIS)
Hedemann Jensen, P.; Thykier-Nielsen, S.
1980-09-01
Calculations of external γ-doses from radioactivity released to the atmosphere have been made using different dose buildup factor formulas. Some of the dose buildup factor formulas are used by the Nordic countries in their respective γ-dose models. A comparison of calculated γ-doses using these dose buildup factors shows that the γ-doses can be significantly dependent on the buildup factor formula used in the calculation. Increasing differences occur for increasing plume height, crosswind distance, and atmospheric stability and also for decreasing downwind distance. It is concluded that the most accurate γ-dose can be calculated by use of Capo's polynomial buildup factor formula. Capo-coefficients have been calculated and shown in this report for γ-energies below the original lower limit given by Capo. (author)
Sheth, Atul C; English, Jennifer
2005-04-01
Several environmental issues are related to the disposal of poultry litter. In an effort to provide a more environmentally friendly alternative than landfill disposal or spreading as a soil amendment, work has been carried out previously at the University of Tennessee Space Institute (UTSI). This past UTSI work was concentrated on developing a catalytic steam gasification concept to produce energy from poultry litter. In the past UTSI studies, preliminary design and economics for a stationary, centralized gasification plant capable of processing approximately 100 ton/day of poultry litter were developed. However, in this preliminary design the economic impact of transporting litter to a centralized gasification plant location was not addressed. To determine the preliminary impact of transporting the poultry litter on the overall economics of this energy conversion plant design, a simple transportation model was developed. This model was used in conjunction with the earlier plant design prepared at UTSI to determine the economic feasibility of a centralized, stationary poultry litter gasification plant. To do so, major variables such as traveling distance, plant feed rate (or capacity), fluctuations in the sales price of the product gas (that means value of the energy), population density of poultry farms, impact of tipping fees, and cost of litter were varied. The study showed that for plant with a capacity of 1000 ton/day to be able to withstand several changes in economic conditions and sustain itself, the poultry farm density would need to be approximately 0.3 houses/mi2. Smaller plants would need either a higher energy price or some kind of subsidy to be economically feasible.
Skolubovich, Yuriy; Skolubovich, Aleksandr; Voitov, Evgeniy; Soppa, Mikhail; Chirkunov, Yuriy
2017-10-01
The article considers the current questions of technological modeling and calculation of the new facility for cleaning natural waters, the clarifier reactor for the optimal operating mode, which was developed in Novosibirsk State University of Architecture and Civil Engineering (SibSTRIN). A calculation technique based on well-known dependences of hydraulics is presented. A calculation example of a structure on experimental data is considered. The maximum possible rate of ascending flow of purified water was determined, based on the 24 hour clarification cycle. The fractional composition of the contact mass was determined with minimal expansion of contact mass layer, which ensured the elimination of stagnant zones. The clarification cycle duration was clarified by the parameters of technological modeling by recalculating maximum possible upward flow rate of clarified water. The thickness of the contact mass layer was determined. Likewise, clarification reactors can be calculated for any other lightening conditions.
Liu, Long; Liu, Wei
2018-04-01
A forward modeling and inversion algorithm is adopted in order to determine the water injection plan in the oilfield water injection network. The main idea of the algorithm is shown as follows: firstly, the oilfield water injection network is inversely calculated. The pumping station demand flow is calculated. Then, forward modeling calculation is carried out for judging whether all water injection wells meet the requirements of injection allocation or not. If all water injection wells meet the requirements of injection allocation, calculation is stopped, otherwise the demand injection allocation flow rate of certain step size is reduced aiming at water injection wells which do not meet requirements, and next iterative operation is started. It is not necessary to list the algorithm into water injection network system algorithm, which can be realized easily. Iterative method is used, which is suitable for computer programming. Experimental result shows that the algorithm is fast and accurate.
Research of coincidence method for calculation model of the specific detector
Energy Technology Data Exchange (ETDEWEB)
Guangchun, Hu; Suping, Liu; Jian, Gong [China Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry
2003-07-01
The physical size of specific detector is known normally, but production business is classified for some sizes that is concerned with the property of detector, such as the well diameter, well depth of detector and dead region. The surface source of even distribution and the sampling method of source particle isotropy sport have been established with the method of Monte Carlo, and gamma ray respond spectral with the {sup 152}Eu surface source been calculated. The experiment have been performed under the same conditions. Calculation and experiment results are compared with relative efficiency coincidence method and spectral similar degree coincidence method. According to comparison as a result, detector model is revised repeatedly to determine the calculation model of detector and to calculate efficiency of detector and spectra. (authors)
Preliminary analysis on hybrid Box-Jenkins - GARCH modeling in forecasting gold price
Yaziz, Siti Roslindar; Azizan, Noor Azlinna; Ahmad, Maizah Hura; Zakaria, Roslinazairimah; Agrawal, Manju; Boland, John
2015-02-01
Gold has been regarded as a valuable precious metal and the most popular commodity as a healthy return investment. Hence, the analysis and prediction of gold price become very significant to investors. This study is a preliminary analysis on gold price and its volatility that focuses on the performance of hybrid Box-Jenkins models together with GARCH in analyzing and forecasting gold price. The Box-Cox formula is used as the data transformation method due to its potential best practice in normalizing data, stabilizing variance and reduces heteroscedasticity using 41-year daily gold price data series starting 2nd January 1973. Our study indicates that the proposed hybrid model ARIMA-GARCH with t-innovation can be a new potential approach in forecasting gold price. This finding proves the strength of GARCH in handling volatility in the gold price as well as overcomes the non-linear limitation in the Box-Jenkins modeling.
Calculations of higher twist distribution functions in the MIT bag model
International Nuclear Information System (INIS)
Signal, A.I.
1997-01-01
We calculate all twist-2, -3 and -4 parton distribution functions involving two quark correlations using the wave function of the MIT bag model. The distributions are evolved up to experimental scales and combined to give the various nucleon structure functions. Comparisons with recent experimental data on higher twist structure functions at moderate values of Q 2 give good agreement with the calculated structure functions. (orig.)
Kanematsu, Yusuke; Tachikawa, Masanori
2015-05-21
Multicomponent quantum mechanical (MC_QM) calculations with polarizable continuum model (PCM) have been tested against liquid (1)H NMR chemical shifts for a test set of 80 molecules. Improvement from conventional quantum mechanical calculations was achieved for MC_QM calculations. The advantage of the multicomponent scheme could be attributed to the geometrical change from the equilibrium geometry by the incorporation of the hydrogen nuclear quantum effect, while that of PCM can be attributed to the change of the electronic structure according to the polarization by solvent effects.
QEDMOD: Fortran program for calculating the model Lamb-shift operator
Shabaev, V. M.; Tupitsyn, I. I.; Yerokhin, V. A.
2018-02-01
We present Fortran package QEDMOD for computing the model QED operator hQED that can be used to account for the Lamb shift in accurate atomic-structure calculations. The package routines calculate the matrix elements of hQED with the user-specified one-electron wave functions. The operator can be used to calculate Lamb shift in many-electron atomic systems with a typical accuracy of few percent, either by evaluating the matrix element of hQED with the many-electron wave function, or by adding hQED to the Dirac-Coulomb-Breit Hamiltonian.
HgTe-CdTe phase diagrams calculation by RAS model
International Nuclear Information System (INIS)
Hady, A.A.A.
1986-11-01
The model of Regular Associated Solutions (RAS) for binary solution, which extended onto the ternary solution was used for Mercury-Cadnium-Tellurim phase diagrams calculations. The function of dissociation parameters is used here as a function of temperature and it is independent of composition. The ratio of mole fractions has a weak dependence on temperature and is not neglected. The calculated liquidus binary temperature and the experimental one are so fitted to give the best values of parameters used to calculate the HgTe-CdTe phase diagrams. (author)
SITE-94. Adaptation of mechanistic sorption models for performance assessment calculations
International Nuclear Information System (INIS)
Arthur, R.C.
1996-10-01
Sorption is considered in most predictive models of radionuclide transport in geologic systems. Most models simulate the effects of sorption in terms of empirical parameters, which however can be criticized because the data are only strictly valid under the experimental conditions at which they were measured. An alternative is to adopt a more mechanistic modeling framework based on recent advances in understanding the electrical properties of oxide mineral-water interfaces. It has recently been proposed that these 'surface-complexation' models may be directly applicable to natural systems. A possible approach for adapting mechanistic sorption models for use in performance assessments, using this 'surface-film' concept, is described in this report. Surface-acidity parameters in the Generalized Two-Layer surface complexation model are combined with surface-complexation constants for Np(V) sorption ob hydrous ferric oxide to derive an analytical model enabling direct calculation of corresponding intrinsic distribution coefficients as a function of pH, and Ca 2+ , Cl - , and HCO 3 - concentrations. The surface film concept is then used to calculate whole-rock distribution coefficients for Np(V) sorption by altered granitic rocks coexisting with a hypothetical, oxidized Aespoe groundwater. The calculated results suggest that the distribution coefficients for Np adsorption on these rocks could range from 10 to 100 ml/g. Independent estimates of K d for Np sorption in similar systems, based on an extensive review of experimental data, are consistent, though slightly conservative, with respect to the calculated values. 31 refs
La Belle, Jeffrey T; Engelschall, Erica; Lan, Kenneth; Shah, Pankti; Saez, Neil; Maxwell, Stephanie; Adamson, Teagan; Abou-Eid, Michelle; McAferty, Kenyon; Patel, Dharmendra R; Cook, Curtiss B
2014-01-01
A prototype tear glucose (TG) sensor was tested in New Zealand white rabbits to assess eye irritation, blood glucose (BG) and TG lag time, and correlation with BG. A total of 4 animals were used. Eye irritation was monitored by Lissamine green dye and analyzed using image analysis software. Lag time was correlated with an oral glucose load while recording TG and BG readings. Correlation between TG and BG were plotted against one another to form a correlation diagram, using a Yellow Springs Instrument (YSI) and self-monitoring of blood glucose as the reference measurements. Finally, TG levels were calculated using analytically derived expressions. From repeated testing carried over the course of 12 months, little to no eye irritation was detected. TG fluctuations over time visually appeared to trace the same pattern as BG with an average lag times of 13 minutes. TG levels calculated from the device current measurements ranged from 4 to 20 mg/dL and correlated linearly with BG levels of 75-160 mg/dL (TG = 0.1723 BG = 7.9448 mg/dL; R 2 = .7544). The first steps were taken toward preliminary development of a sensor for self-monitoring of tear glucose (SMTG). No conjunctival irritation in any of the animals was noted. Lag time between TG and BG was found to be noticeable, but a quantitative modeling to correlate lag time in this study is unnecessary. Measured currents from the sensors and the calculated TG showed promising correlation to BG levels. Previous analytical bench marking showed BG and TG levels consistent with other literature. © 2014 Diabetes Technology Society.
A pencil beam dose calculation model for CyberKnife system
Energy Technology Data Exchange (ETDEWEB)
Liang, Bin; Li, Yongbao; Liu, Bo; Zhou, Fugen [Image Processing Center, Beihang University, Beijing 100191 (China); Xu, Shouping [Department of Radiation Oncology, PLA General Hospital, Beijing 100853 (China); Wu, Qiuwen, E-mail: Qiuwen.Wu@Duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)
2016-10-15
Purpose: CyberKnife system is initially equipped with fixed circular cones for stereotactic radiosurgery. Two dose calculation algorithms, Ray-Tracing and Monte Carlo, are available in the supplied treatment planning system. A multileaf collimator system was recently introduced in the latest generation of system, capable of arbitrarily shaped treatment field. The purpose of this study is to develop a model based dose calculation algorithm to better handle the lateral scatter in an irregularly shaped small field for the CyberKnife system. Methods: A pencil beam dose calculation algorithm widely used in linac based treatment planning system was modified. The kernel parameters and intensity profile were systematically determined by fitting to the commissioning data. The model was tuned using only a subset of measured data (4 out of 12 cones) and applied to all fixed circular cones for evaluation. The root mean square (RMS) of the difference between the measured and calculated tissue-phantom-ratios (TPRs) and off-center-ratio (OCR) was compared. Three cone size correction techniques were developed to better fit the OCRs at the penumbra region, which are further evaluated by the output factors (OFs). The pencil beam model was further validated against measurement data on the variable dodecagon-shaped Iris collimators and a half-beam blocked field. Comparison with Ray-Tracing and Monte Carlo methods was also performed on a lung SBRT case. Results: The RMS between the measured and calculated TPRs is 0.7% averaged for all cones, with the descending region at 0.5%. The RMSs of OCR at infield and outfield regions are both at 0.5%. The distance to agreement (DTA) at the OCR penumbra region is 0.2 mm. All three cone size correction models achieve the same improvement in OCR agreement, with the effective source shift model (SSM) preferred, due to their ability to predict more accurately the OF variations with the source to axis distance (SAD). In noncircular field validation
International Nuclear Information System (INIS)
Cliffe, K.A.; Morris, S.T.; Porter, J.D.
1998-05-01
NAMMU is a computer program for modelling groundwater flow and transport through porous media. This document provides an overview of the use of the program for geosphere modelling in performance assessment calculations and gives a detailed description of the program itself. The aim of the document is to give an indication of the grounds for having confidence in NAMMU as a performance assessment tool. In order to achieve this the following topics are discussed. The basic premises of the assessment approach and the purpose of and nature of the calculations that can be undertaken using NAMMU are outlined. The concepts of the validation of models and the considerations that can lead to increased confidence in models are described. The physical processes that can be modelled using NAMMU and the mathematical models and numerical techniques that are used to represent them are discussed in some detail. Finally, the grounds that would lead one to have confidence that NAMMU is fit for purpose are summarised
International Nuclear Information System (INIS)
Webb, G.A.M.; Grimwood, P.D.
1976-12-01
This report describes an oceanographic model which has been developed for the use in calculating the capacity of the oceans to accept radioactive wastes. One component is a relatively short-term diffusion model which is based on that described in an earlier report (Webb et al., NRPB-R14(1973)), but which has been generalised to some extent. Another component is a compartment model which is used to calculate long-term widespread water concentrations. This addition overcomes some of the short comings of the earlier diffusion model. Incorporation of radioactivity into deep ocean sediments is included in this long-term model as a removal mechanism. The combined model is used to provide a conservative (safe) estimate of the maximum concentrations of radioactivity in water as a function of time after the start of a continuous disposal operation. These results can then be used to assess the limiting capacity of an ocean to accept radioactive waste. (author)
Energy Technology Data Exchange (ETDEWEB)
Foust, J. [Voith Hydro, Inc., York, PA (USA); Hecker, G. [Alden Research Laboratory, Inc., Holden, MA (USA); Li, S. [Alden Research Laboratory, Inc., Holden, MA (USA); Allen, G. [Alden Research Laboratory, Inc., Holden, MA (USA)
2011-10-01
The Alden turbine was developed through the U.S. Department of Energy's (DOE's) former Advanced Hydro Turbine Systems Program (1994-2006) and, more recently, through the Electric Power Research Institute (EPRI) and the DOE's Wind & Water Power Program. The primary goal of the engineering study described here was to provide a commercially competitive turbine design that would yield fish passage survival rates comparable to or better than the survival rates of bypassing or spilling flow. Although the turbine design was performed for site conditions corresponding to 92 ft (28 m) net head and a discharge of 1500 cfs (42.5 cms), the design can be modified for additional sites with differing operating conditions. During the turbine development, design modifications were identified for the spiral case, distributor (stay vanes and wicket gates), runner, and draft tube to improve turbine performance while maintaining features for high fish passage survival. Computational results for pressure change rates and shear within the runner passage were similar in the original and final turbine geometries, while predicted minimum pressures were higher for the final turbine. The final turbine geometry and resulting flow environments are expected to further enhance the fish passage characteristics of the turbine. Computational results for the final design were shown to improve turbine efficiencies by over 6% at the selected operating condition when compared to the original concept. Prior to the release of the hydraulic components for model fabrication, finite element analysis calculations were conducted for the stay vanes, wicket gates, and runner to verify that structural design criteria for stress and deflections were met. A physical model of the turbine was manufactured and tested with data collected for power and efficiency, cavitation limits, runaway speed, axial and radial thrust, pressure pulsations, and wicket gate torque. All parameters were observed to fall
International Nuclear Information System (INIS)
Schick, W.C. Jr.; Milani, S.; Duncombe, E.
1980-03-01
A model has been devised for incorporating into the thermal feedback procedure of the PDQ few-group diffusion theory computer program the explicit calculation of depletion and temperature dependent fuel-rod shrinkage and swelling at each mesh point. The model determines the effect on reactivity of the change in hydrogen concentration caused by the variation in coolant channel area as the rods contract and expand. The calculation of fuel temperature, and hence of Doppler-broadened cross sections, is improved by correcting the heat transfer coefficient of the fuel-clad gap for the effects of clad creep, fuel densification and swelling, and release of fission-product gases into the gap. An approximate calculation of clad stress is also included in the model
International Nuclear Information System (INIS)
Allam, Kh. A.
2017-01-01
In this work, a new methodology is developed based on Monte Carlo simulation for tunnels and mines external dose calculation. Tunnels external dose evaluation model of a cylindrical shape of finite thickness with an entrance and with or without exit. A photon transportation model was applied for exposure dose calculations. A new software based on Monte Carlo solution was designed and programmed using Delphi programming language. The variation of external dose due to radioactive nuclei in a mine tunnel and the corresponding experimental data lies in the range 7.3 19.9%. The variation of specific external dose rate with position in, tunnel building material density and composition were studied. The given new model has more flexible for real external dose in any cylindrical tunnel structure calculations. (authors)
Development of a model for the primary system CAREM reactor's stationary thermohydraulic calculation
International Nuclear Information System (INIS)
Gaspar, C.; Abbate, P.
1990-01-01
The ESCAREM program oriented to CAREM reactors' stationary thermohydraulic calculation is presented. As CAREM gives variations in relation to models for BWR (Boiling Water Reactors)/PWR (Pressurized Water Reactors) reactors, it was decided to develop a suitable model which allows to calculate: a) if the Steam Generator design is adequate to transfer the power required; b) the circulation flow that occurs in the Primary System; c) the temperature at the entrance (cool branch) and d) the contribution of each component to the pressure drop in the circulation connection. Results were verified against manual calculations and alternative numerical models. An experimental validation at the Thermohydraulic Essays Laboratory is suggested. A parametric analysis series is presented on CAREM 25 reactor, demonstrating operating conditions, at different power levels, as well as the influence of different design aspects. (Author) [es
International Nuclear Information System (INIS)
Honda, M.; Kajita, T.; Kasahara, K.; Midorikawa, S.; Sanuki, T.
2007-01-01
Using the 'modified DPMJET-III' model explained in the previous paper [T. Sanuki et al., preceding Article, Phys. Rev. D 75, 043005 (2007).], we calculate the atmospheric neutrino flux. The calculation scheme is almost the same as HKKM04 [M. Honda, T. Kajita, K. Kasahara, and S. Midorikawa, Phys. Rev. D 70, 043008 (2004).], but the usage of the 'virtual detector' is improved to reduce the error due to it. Then we study the uncertainty of the calculated atmospheric neutrino flux summarizing the uncertainties of individual components of the simulation. The uncertainty of K-production in the interaction model is estimated using other interaction models: FLUKA'97 and FRITIOF 7.02, and modifying them so that they also reproduce the atmospheric muon flux data correctly. The uncertainties of the flux ratio and zenith angle dependence of the atmospheric neutrino flux are also studied
Numerical calculation models of the elastoplastic response of a structure under seismic action
International Nuclear Information System (INIS)
Edjtemai, Nima.
1982-06-01
Two digital calculation models developed in this work have made it possible to analyze the exact dynamic behaviour of ductile structures with one or several degrees of liberty, during earthquakes. With the first model, response spectra were built in the linear and non-linear fields for different absorption and ductility values and two types of seismic accelerograms. The comparative study of these spectra made it possible to check the validity of certain hypotheses suggested for the construction of elastoplastic spectra from corresponding linear spectra. A simplified method of non-linear seismic calculation based on the modal analysis and the spectra of elastoplastic response was then applied to structures with a varying number of degrees of liberty. The results obtained in this manner were compared with those provided by an exact calculation provided by the second digital model developed by us [fr
Fission product model for lattice calculation of high conversion boiling water reactor
International Nuclear Information System (INIS)
Iijima, S.; Yoshida, T.; Yamamoto, T.
1988-01-01
A high precision fission product model for boiling water reactor (BWR) lattice calculation was developed, which consists of 45 nuclides to be treated explicitly and one nonsaturating pseudo nuclide. This model is applied to a high conversion BWR lattice calculation code. From a study based on a three-energy-group calculation of fission product poisoning due to full fission products and explicitly treated nuclides, the multigroup capture cross sections and the effective fission yields of the pseudo nuclide are determined, which do not depend on fuel types or reactor operating conditions for a good approximation. Apart from nuclear data uncertainties, the model and the derived pseudo nuclide constants would predict the fission product reactivity within an error of 0.1% Δk at high burnup
CLEAR: a model for the calculation of evacuation-time estimates in Emergency Planning Zones
International Nuclear Information System (INIS)
McLean, M.A.; Moeller, M.P.; Desrosiers, A.E.
1983-01-01
This paper describes the methodology and application of the computer model CLEAR (Calculates Logical Evacuation And Response) which estimates the time required for a specific population density and distribution to evacuate an area using a specific transportation network. The CLEAR model simulates vehicle departure and movement on a transportation network according to the conditions and consequences of traffice flow. These include handling vehicles at intersecting road segments, calculating the velocity of travel on a road segment as a function of its vehicle density, and accounting for the delay of vehicles in traffice queues. The program also models the distribution of times required by individuals to prepare for an evacuation. CLEAR can calculate realistic evacuation time estimates using site specific data and can identify troublesome areas within an Emergency Planning Zone
Weck, Philippe F; Kim, Eunja; Wang, Yifeng; Kruichak, Jessica N; Mills, Melissa M; Matteo, Edward N; Pellenq, Roland J-M
2017-08-01
Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematically compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.
Energy Technology Data Exchange (ETDEWEB)
Sukegawa, Takenori; Ohshima, Soichiro; Shiraishi, Kunio; Yanagihara, Satoshi [Department of Decommissioning and Waste Management, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai Ibaraki (Japan)
1999-02-01
Labor-hours necessary for dismantling activities are generally estimated based on experience, for example, as a form of unit productivity factors such as the relationship between labor-hours and weight of components dismantled which were obtained by actual dismantling activities. The project management data calculation models together with unit productivity factors for basic dismantling work activities were developed by analyzing the data obtained from the Japan Power Demonstration Reactor (JPDR) dismantling project, which will be applicable to estimation of labor-hours in various dismantling conditions. Typical work breakdown structures were also prepared by categorizing repeatable basic dismantling work activities for effective planning of dismantling activities. The labor-hours for dismantling the JPDR components and structures were calculated by using the code system for management of reactor decommissioning (COSMARD), in which the work breakdown structures and the calculation models were contained. It was confirmed that the labor-hours could be easily estimated by COSMARD through the calculations. This report describes the labor-hour calculation models and application of these models to COSMARD. (author)
Azimi, Ehsan; Behrad, Alireza; Ghaznavi-Ghoushchi, Mohammad Bagher; Shanbehzadeh, Jamshid
2016-11-01
The projective model is an important mapping function for the calculation of global transformation between two images. However, its hardware implementation is challenging because of a large number of coefficients with different required precisions for fixed point representation. A VLSI hardware architecture is proposed for the calculation of a global projective model between input and reference images and refining false matches using random sample consensus (RANSAC) algorithm. To make the hardware implementation feasible, it is proved that the calculation of the projective model can be divided into four submodels comprising two translations, an affine model and a simpler projective mapping. This approach makes the hardware implementation feasible and considerably reduces the required number of bits for fixed point representation of model coefficients and intermediate variables. The proposed hardware architecture for the calculation of a global projective model using the RANSAC algorithm was implemented using Verilog hardware description language and the functionality of the design was validated through several experiments. The proposed architecture was synthesized by using an application-specific integrated circuit digital design flow utilizing 180-nm CMOS technology as well as a Virtex-6 field programmable gate array. Experimental results confirm the efficiency of the proposed hardware architecture in comparison with software implementation.
Application of the mathematical modelling and human phantoms for calculation of the organ doses
International Nuclear Information System (INIS)
Kluson, J.; Cechak, T.
2005-01-01
Increasing power of the computers hardware and new versions of the software for the radiation transport simulation and modelling of the complex experimental setups and geometrical arrangement enable to dramatically improve calculation of organ or target volume doses ( dose distributions) in the wide field of medical physics and radiation protection applications. Increase of computers memory and new software features makes it possible to use not only analytical (mathematical) phantoms but also allow constructing the voxel models of human or phantoms with voxels fine enough (e.g. 1·1·1 mm) to represent all required details. CT data can be used for the description of such voxel model geometry .Advanced scoring methods are available in the new software versions. Contribution gives the overview of such new possibilities in the modelling and doses calculations, discusses the simulation/approximation of the dosimetric quantities ( especially dose ) and calculated data interpretation. Some examples of application and demonstrations will be shown, compared and discussed. Present computational tools enables to calculate organ or target volumes doses with new quality of large voxel models/phantoms (including CT based patient specific model ), approximating the human body with high precision. Due to these features has more and more importance and use in the fields of medical and radiological physics, radiation protection, etc. (authors)
A model for calculating hourly global solar radiation from satellite data in the tropics
International Nuclear Information System (INIS)
Janjai, S.; Pankaew, P.; Laksanaboonsong, J.
2009-01-01
A model for calculating global solar radiation from geostationary satellite data is presented. The model is designed to calculate the monthly average hourly global radiation in the tropics with high aerosol load. This model represents a physical relation between the earth-atmospheric albedo derived from GMS5 satellite data and the absorption and scattering coefficients of various atmospheric constituents. The absorption of solar radiation by water vapour which is important for the tropics, was calculated from ambient temperature and relative humidity. The relationship between the visibility and solar radiation depletion due to aerosols was developed for a high aerosol load environment. This relationship was used to calculate solar radiation depletion by aerosols in the model. The total column ozone from TOMS/EP satellite was employed for the determination of solar radiation absorbed by ozone. Solar radiation from four pyranometer stations was used to formulate the relationship between the satellite band earth-atmospheric albedo and broadband earth-atmospheric albedo required by the model. To test its performance, the model was used to compute the monthly average hourly global radiation at 25 solar radiation monitoring stations in tropical areas in Thailand. It was found that the values of monthly average of hourly global radiations calculated from the model were in good agreement with those obtained from the measurements, with the root mean square difference of 10%. After the validation the model was employed to generate hourly solar radiation maps of Thailand. These maps reveal the diurnal and season variation of solar radiation over the country.
A model for calculating hourly global solar radiation from satellite data in the tropics
Energy Technology Data Exchange (ETDEWEB)
Janjai, S.; Pankaew, P.; Laksanaboonsong, J. [Solar Energy Research Laboratory, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand)
2009-09-15
A model for calculating global solar radiation from geostationary satellite data is presented. The model is designed to calculate the monthly average hourly global radiation in the tropics with high aerosol load. This model represents a physical relation between the earth-atmospheric albedo derived from GMS5 satellite data and the absorption and scattering coefficients of various atmospheric constituents. The absorption of solar radiation by water vapour which is important for the tropics, was calculated from ambient temperature and relative humidity. The relationship between the visibility and solar radiation depletion due to aerosols was developed for a high aerosol load environment. This relationship was used to calculate solar radiation depletion by aerosols in the model. The total column ozone from TOMS/EP satellite was employed for the determination of solar radiation absorbed by ozone. Solar radiation from four pyranometer stations was used to formulate the relationship between the satellite band earth-atmospheric albedo and broadband earth-atmospheric albedo required by the model. To test its performance, the model was used to compute the monthly average hourly global radiation at 25 solar radiation monitoring stations in tropical areas in Thailand. It was found that the values of monthly average of hourly global radiations calculated from the model were in good agreement with those obtained from the measurements, with the root mean square difference of 10%. After the validation the model was employed to generate hourly solar radiation maps of Thailand. These maps reveal the diurnal and season variation of solar radiation over the country. (author)
Half-life calculation of one-proton emitters with a shell model potential
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, M. M.; Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas-CBPF/MCT Rua Dr. Xavier Sigaud, 150, 22290-180, Rio de Janeiro-RJ (Brazil); Teruya, N. [Departamento de Fisica, Universidade Federal da Paraiba - UFPB Campus de Joao Pessoa, 58051-970, Joao Pessoa - PB (Brazil)
2013-03-25
The accumulated amount of data for half-lives of proton emitters still remains a challenge to the ability of nuclear models to reproduce them consistently. These nuclei are far from beta stability line in a region where the validity of current nuclear models is not guaranteed. A nuclear shell model is introduced to the calculation of the nuclear barrier of less deformed proton emitters. The predictions using the proposed model are in good agreement with the data, with the advantage of have used only a single parameter in the model.
Calculation of the band structure of 2d conducting polymers using the network model
International Nuclear Information System (INIS)
Sabra, M. K.; Suman, H.
2007-01-01
the network model has been used to calculate the band structure the gap energy and Fermi level of conducting polymers in two dimensions. For this purpose, a geometrical classification of possible polymer chains configurations in two dimensions has been introduced leading to a classification of the unit cells based on the number of bonds in them. The model has been applied to graphite in 2D, represented by a three bonds unit cell, and, as a new case, the anti-parallel Polyacetylene chains (PA) in two dimensions, represented by a unit cell with four bons. The results are in good agreement with the first principles calculations. (author)
Numerical calculation of flashing from long pipes using a two-field model
International Nuclear Information System (INIS)
Rivard, W.C.; Torrey, M.D.
1976-05-01
A two-field model for two-phase flows, in which the vapor and liquid phases have different densities, velocities, and temperatures, has been used to calculate the flashing of water from long pipes. The IMF (Implicit Multifield) technique is used to numerically solve the transient equations that govern the dynamics of each phase. The flow physics is described with finite rate phase transitions, interfacial friction, heat transfer, pipe wall friction, and appropriate state equations. The results of the calculations are compared with measured histories of pressure, temperature, and void fraction. A parameter study indicates the relative sensitivity of the results to the various physical models that are used
Numerical calculation of flashing from long pipes using a two-field model
International Nuclear Information System (INIS)
Rivard, W.C.; Torrey, M.D.
1975-11-01
A two-field model for two-phase flows, in which the vapor and liquid phases have different densities, velocities, and temperatures, has been used to calculate the flashing of water from long pipes. The IMF (Implicit Multifield) technique is used to numerically solve the transient equations that govern the dynamics of each phase. The flow physics is described with finite rate phase transitions, interfacial friction, heat transfer, pipe wall friction, and appropriate state equations. The results of the calculations are compared with measured histories of pressure, temperature, and void fraction. A parameter study indicates the relative sensitivity of the results to the various physical models that are used
Recoilless fractions calculated with the nearest-neighbour interaction model by Kagan and Maslow
Kemerink, G. J.; Pleiter, F.
1986-08-01
The recoilless fraction is calculated for a number of Mössbauer atoms that are natural constituents of HfC, TaC, NdSb, FeO, NiO, EuO, EuS, EuSe, EuTe, SnTe, PbTe and CsF. The calculations are based on a model developed by Kagan and Maslow for binary compounds with rocksalt structure. With the exception of SnTe and, to a lesser extent, PbTe, the results are in reasonable agreement with the available experimental data and values derived from other models.
International Nuclear Information System (INIS)
Nielsen, S.P.; Gryning, S.E.; Thykier-Nielsen, S.; Karlberg, O.; Lyck, E.
1984-01-01
The paper presents work from a series of atmospheric dispersion experiments in May 1981 at the Ringhals nuclear power plant in Sweden. The aim of the project was to obtain short-term observations of concentrations and gamma-ray exposures from stack effluents and to compare these results with corresponding values calculated from computer models. Two tracers, sulphurhexafluoride (SF 6 ) and radioactive noble gases, were released from a 110-m stack and detected at ground level downwind at distances of 3-4 km. Calculations were made with two Gaussian plume models: PLUCON developed at Riso National Laboratory and UNIDOSE developed at Studsvik Energiteknik AB. (orig.)
Cocciaro, B.; Faetti, S.; Fronzoni, L.
2017-08-01
As shown in the EPR paper (Einstein, Podolsky e Rosen, 1935), Quantum Mechanics is a non-local Theory. The Bell theorem and the successive experiments ruled out the possibility of explaining quantum correlations using only local hidden variables models. Some authors suggested that quantum correlations could be due to superluminal communications that propagate isotropically with velocity vt > c in a preferred reference frame. For finite values of vt and in some special cases, Quantum Mechanics and superluminal models lead to different predictions. So far, no deviations from the predictions of Quantum Mechanics have been detected and only lower bounds for the superluminal velocities vt have been established. Here we describe a new experiment that increases the maximum detectable superluminal velocities and we give some preliminary results.
Cognitive Work Analysis: Preliminary Data for a Model of Problem Solving Strategies
Rothmayer, Mark; Blue, Jennifer
2007-10-01
Investigations into problem solving strategies are part of the field of physics education research where investigators seek to improve physics instruction by conducting basic research of problem solving abilities among students, differences in knowledge representations between experts and novices, and how to transfer knowledge structures more effectively onto novices. We developed a new conceptual research tool in our laboratory, where we could potentially map the step by step flow of problem solving strategies among experts and novices. This model is derived from the theory of Cognitive Work Analysis, which is grounded in ecological psychology, and as far as we know it has never been applied to a knowledge domain like physics. We collected survey data from 140 undergraduates enrolled in an algebra based introductory physics course at Miami University as part of a larger study aimed to test the validity of the model. Preliminary data will be presented and discussed.
Comparison of turbulence models for numerical calculation of airflow in an annex 20 room
DEFF Research Database (Denmark)
Voigt, Lars P. K.
2000-01-01
The report deals with 2-D numerical calculation of room airflow in an isothermal annex 20 room. The report documents the ability of the flow solver EllipSys2D to give results in good agreement with measurements for the specified test case. The flow solver is a finite volume code solving the Reyno.......Applying theory for a two-dimensional wall jet, measurements are compared with calculated values of the turbulent kinetic energy....... the Reynolds Averaged Navier Stokes equations.Five two-equation turbulence models were tested. These are the standard k-epsilon model, the low-Reynolds number k-epison model by Launder & Sharma, the k-omega model by Wilcox, the k-omega baseline (BSL) model by Menter and the k-omega Shear Stress Transport (SST...
DEFF Research Database (Denmark)
Mattsson, T.R.; Wahnström, G.; Bengtsson, L.
1997-01-01
First-principles density-functional calculations of hydrogen adsorption on the Ni (001) surface have been performed in order to get a better understanding of adsorption and diffusion of hydrogen on metal surfaces. We find good agreement with experiments for the adsorption energy, binding distance...
International Nuclear Information System (INIS)
Lu Xiaogang; Selleby, Malin; Sundman, Bo
2007-01-01
The thermal expansivities and heat capacities of MX (M = Ti, Zr, Hf, V, Nb, Ta; X = C, N) carbides and nitrides with NaCl structure were calculated using the Debye-Grueneisen model combined with ab initio calculations. Two different approximations for the Grueneisen parameter γ were used in the Debye-Grueneisen model, i.e. the expressions proposed by Slater and by Dugdale and MacDonald. The thermal electronic contribution was evaluated from ab initio calculations of the electronic density of states. The calculated results were compared with CALPHAD assessments and experimental data. It was found that the calculations using the Dugdale-MacDonald γ can account for most of the experimental data. By fitting experimental heat capacity and thermal expansivity data below the Debye temperatures, an estimation of Poisson's ratio was obtained and Young's and shear moduli were evaluated. In order to reach a reasonable agreement with experimental data, it was necessary to use the logarithmic averaged mass of the constituent atoms. The agreements between the calculated and the experimental values for the bulk and Young's moduli are generally better than the agreement for shear modulus
Water-Exit Process Modeling and Added-Mass Calculation of the Submarine-Launched Missile
Directory of Open Access Journals (Sweden)
Yang Jian
2017-11-01
Full Text Available In the process that the submarine-launched missile exits the water, there is the complex fluid solid coupling phenomenon. Therefore, it is difficult to establish the accurate water-exit dynamic model. In the paper, according to the characteristics of the water-exit motion, based on the traditional method of added mass, considering the added mass changing rate, the water-exit dynamic model is established. And with help of the CFX fluid simulation software, a new calculation method of the added mass that is suit for submarine-launched missile is proposed, which can effectively solve the problem of fluid solid coupling in modeling process. Then by the new calculation method, the change law of the added mass in water-exit process of the missile is obtained. In simulated analysis, for the water-exit process of the missile, by comparing the results of the numerical simulation and the calculation of theoretical model, the effectiveness of the new added mass calculation method and the accuracy of the water-exit dynamic model that considers the added mass changing rate are verified.
Unified description of pf-shell nuclei by the Monte Carlo shell model calculations
Energy Technology Data Exchange (ETDEWEB)
Mizusaki, Takahiro; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Honma, Michio
1998-03-01
The attempts to solve shell model by new methods are briefed. The shell model calculation by quantum Monte Carlo diagonalization which was proposed by the authors is a more practical method, and it became to be known that it can solve the problem with sufficiently good accuracy. As to the treatment of angular momentum, in the method of the authors, deformed Slater determinant is used as the basis, therefore, for making angular momentum into the peculiar state, projected operator is used. The space determined dynamically is treated mainly stochastically, and the energy of the multibody by the basis formed as the result is evaluated and selectively adopted. The symmetry is discussed, and the method of decomposing shell model space into dynamically determined space and the product of spin and isospin spaces was devised. The calculation processes are shown with the example of {sup 50}Mn nuclei. The calculation of the level structure of {sup 48}Cr with known exact energy can be done with the accuracy of peculiar absolute energy value within 200 keV. {sup 56}Ni nuclei are the self-conjugate nuclei of Z=N=28. The results of the shell model calculation of {sup 56}Ni nucleus structure by using the interactions of nuclear models are reported. (K.I.)
Hydroelastic model of PWR reactor internals SAFRAN 1 - Validation of a vibration calculation method
International Nuclear Information System (INIS)
Epstein, A.; Gibert, R.J.; Jeanpierre, F.; Livolant, M.
1978-01-01
The SAFRAN 1 test loop consists of an hydroelastic similitude of a 1/8 scale model of a 3 loop P.W.R. Vibrations of the main internals (thermal shield and core barrel) and pressure fluctuations in water thin sections between vessel and internals, and in inlet and outlet pipes, have been measured. The calculation method consists of: an evaluation of the main vibration and acoustic sources owing to the flow (unsteady jet impingement on the core barrel, turbulent flow in a water thin section). A calculation of the internal modal parameters taking into account the inertial effects of fluid (the computer codes AQUAMODE and TRISTANA have been used). A calculation of the acoustic response of the circuit (the computer code VIBRAPHONE has been used). The good agreement between the calculation and the experimental results allows using this method with better security for the prediction of the vibration levels of full scale P.W.R. internals
Analytical model for calculation of the thermo hydraulic parameters in a fuel rod assembly
Energy Technology Data Exchange (ETDEWEB)
Cesna, B., E-mail: benas@mail.lei.l [Lithuanian Energy Institute, Laboratory of Nuclear Installation Safety, Breslaujos g. 3, LT-44403 Kaunas (Lithuania)
2010-11-15
Research highlights: {yields} Proposed calculation model can be used for rapid calculation of the bundles with rods spaced by wire wrapping or honey type spacer grids. {yields} Model estimate three flow cross mixture mechanisms. {yields} Program DARS is enable to analyses experimental results. - Abstract: The paper presents the procedure of the cellular calculation of thermo hydraulic parameters of a single-phase gas flow in a fuel rod assembly. The procedure is implemented in the DARS program. The program is intended for calculation of the distribution of the gaseous coolant parameters and wall temperatures in case of arbitrary, geometrically specified, arrangement of the rods in fuel assembly and in case of arbitrary, functionally specified in space, heat release in the rods. In mathematical model the flow cross-section of the channel of intricate shape is conventionally divided to elementary cells formed by straight lines, which connect the centers of rods. Within the limits of a single cell the coolant parameters and the temperature of the corresponding part of the rod surface are assumed constant. The entire fuel assembly is viewed as a system of parallel interconnected channels. Program DARS is illustrated by calculation of a temperature mode of 85-rod assembly with spacers of wire wrapping on the rods.
Energy Technology Data Exchange (ETDEWEB)
Sanchidrian, Jose A.; Lopez, Lina M. [Universidad Politecnica de Madrid - E.T.S.I. Minas, Rios Rosas 21, E-28003 Madrid (Spain)
2006-02-15
The energy delivered by explosives is described by means of the useful expansion work along the isentrope of the detonation products. A thermodynamic code (W-DETCOM) is used, in which a partial reaction model has been implemented. In this model, the reacted fraction of the explosive in the detonation state is used as a fitting factor so that the calculated detonation velocity meets the experimental value. Calculations based on such a model have been carried out for a number of commercial explosives of ANFO and emulsion types. The BKW (Becker-Kistiakowsky-Wilson) equation of state is used for the detonation gases with the Sandia parameter set (BKWS). The energy delivered in the expansion (useful work) is calculated, and the values obtained are compared with the Gurney energies from cylinder test data at various expansion ratios. The expansion work values obtained are much more realistic than those from an ideal detonation calculation and, in most cases, the values predicted by the calculation are in good agreement with the experimental ones. (Abstract Copyright [2006], Wiley Periodicals, Inc.)
Energy Technology Data Exchange (ETDEWEB)
Murata, Isao [Osaka Univ., Suita (Japan); Mori, Takamasa; Nakagawa, Masayuki; Itakura, Hirofumi
1996-03-01
The method to calculate neutronics parameters of a core composed of randomly distributed spherical fuels has been developed based on a statistical geometry model with a continuous energy Monte Carlo method. This method was implemented in a general purpose Monte Carlo code MCNP, and a new code MCNP-CFP had been developed. This paper describes the model and method how to use it and the validation results. In the Monte Carlo calculation, the location of a spherical fuel is sampled probabilistically along the particle flight path from the spatial probability distribution of spherical fuels, called nearest neighbor distribution (NND). This sampling method was validated through the following two comparisons: (1) Calculations of inventory of coated fuel particles (CFPs) in a fuel compact by both track length estimator and direct evaluation method, and (2) Criticality calculations for ordered packed geometries. This method was also confined by applying to an analysis of the critical assembly experiment at VHTRC. The method established in the present study is quite unique so as to a probabilistic model of the geometry with a great number of spherical fuels distributed randomly. Realizing the speed-up by vector or parallel computations in future, it is expected to be widely used in calculation of a nuclear reactor core, especially HTGR cores. (author).
Physical frailty, disability, and dynamics in health perceptions: a preliminary mediation model
Directory of Open Access Journals (Sweden)
Mulasso A
2016-03-01
Full Text Available Anna Mulasso, Mattia Roppolo, Emanuela Rabaglietti Department of Psychology, University of Torino, Torino, Italy Purpose: Frailty is a condition characterized by loss of functional reserve and altered homeostatic capacity. The aging process is related with complex indicators of physiological state. This study aims, with a preliminary mediation model, to reveal the possible role of mediator of health perceptions variability in the relationship between frailty and disability. Patients and methods: A longitudinal study (100 days was performed. Data from 92 institutionalized older adults were used in the analysis. Frailty was assessed in baseline using the Italian version of the Survey of Health, Ageing and Retirement in Europe – Frailty Instrument; health perceptions were assessed on a daily basis by three visual analog scale questions; and disability was measured in baseline and post-test using the Katz Activities of Daily Living questionnaire. The product-of-coefficient mediation approach was used to test direct and indirect effects of frailty. Results: Results showed that daily variability of health perceptions plays the role of mediator between frailty and disability. In all the steps, statistically significant results were found. Conclusion: This preliminary result may indicate that physical frailty increases the variability in health perceptions contributing to disability. Keywords: functional decline, loss of autonomy, variability, health outcomes, dynamic systems
Program realization of mathematical model of kinetostatical calculation of flat lever mechanisms
Directory of Open Access Journals (Sweden)
M. A. Vasechkin
2016-01-01
Full Text Available Global computerization determined the dominant position of the analytical methods for the study of mechanisms. As a result, kinetostatics analysis of mechanisms using software packages is an important part of scientific and practical activities of engineers and designers. Therefore, software implementation of mathematical models kinetostatical calculating mechanisms is of practical interest. The mathematical model obtained in [1]. In the language of Turbo Pascal developed a computer procedure that calculates the forces in kinematic pairs in groups Assur (GA and a balancing force at the primary level. Before use appropriate computational procedures it is necessary to know all external forces and moments acting on the GA and to determine the inertial forces and moments of inertia forces. The process of calculations and constructions of the provisions of the mechanism can be summarized as follows. Organized cycle in which to calculate the position of an initial link of the mechanism. Calculate the position of the remaining links of the mechanism by referring to relevant procedures module DIADA in GA [2,3]. Using the graphics mode of the computer displaying on the display the position of the mechanism. The computed inertial forces and moments of inertia forces. Turning to the corresponding procedures of the module, calculated all the forces in kinematic pairs and the balancing force at the primary level. In each kinematic pair build forces and their direction with the help of simple graphical procedures. The magnitude of these forces and their direction are displayed in a special window with text mode. This work contains listings of the test programs MyTеst, is an example of using computing capabilities of the developed module. As a check on the calculation procedures of module in the program is reproduced an example of calculating the balancing forces according to the method of Zhukovsky (Zhukovsky lever.
Microscopic calculation of level densities: the shell model Monte Carlo approach
International Nuclear Information System (INIS)
Alhassid, Yoram
2012-01-01
The shell model Monte Carlo (SMMC) approach provides a powerful technique for the microscopic calculation of level densities in model spaces that are many orders of magnitude larger than those that can be treated by conventional methods. We discuss a number of developments: (i) Spin distribution. We used a spin projection method to calculate the exact spin distribution of energy levels as a function of excitation energy. In even-even nuclei we find an odd-even staggering effect (in spin). Our results were confirmed in recent analysis of experimental data. (ii) Heavy nuclei. The SMMC approach was extended to heavy nuclei. We have studied the crossover between vibrational and rotational collectivity in families of samarium and neodymium isotopes in model spaces of dimension approx. 10 29 . We find good agreement with experimental results for both state densities and 2 > (where J is the total spin). (iii) Collective enhancement factors. We have calculated microscopically the vibrational and rotational enhancement factors of level densities versus excitation energy. We find that the decay of these enhancement factors in heavy nuclei is correlated with the pairing and shape phase transitions. (iv) Odd-even and odd-odd nuclei. The projection on an odd number of particles leads to a sign problem in SMMC. We discuss a novel method to calculate state densities in odd-even and odd-odd nuclei despite the sign problem. (v) State densities versus level densities. The SMMC approach has been used extensively to calculate state densities. However, experiments often measure level densities (where levels are counted without including their spin degeneracies.) A spin projection method enables us to also calculate level densities in SMMC. We have calculated the SMMC level density of 162 Dy and found it to agree well with experiments
A single-source photon source model of a linear accelerator for Monte Carlo dose calculation.
Nwankwo, Obioma; Glatting, Gerhard; Wenz, Frederik; Fleckenstein, Jens
2017-01-01
To introduce a new method of deriving a virtual source model (VSM) of a linear accelerator photon beam from a phase space file (PSF) for Monte Carlo (MC) dose calculation. A PSF of a 6 MV photon beam was generated by simulating the interactions of primary electrons with the relevant geometries of a Synergy linear accelerator (Elekta AB, Stockholm, Sweden) and recording the particles that reach a plane 16 cm downstream the electron source. Probability distribution functions (PDFs) for particle positions and energies were derived from the analysis of the PSF. These PDFs were implemented in the VSM using inverse transform sampling. To model particle directions, the phase space plane was divided into a regular square grid. Each element of the grid corresponds to an area of 1 mm2 in the phase space plane. The average direction cosines, Pearson correlation coefficient (PCC) between photon energies and their direction cosines, as well as the PCC between the direction cosines were calculated for each grid element. Weighted polynomial surfaces were then fitted to these 2D data. The weights are used to correct for heteroscedasticity across the phase space bins. The directions of the particles created by the VSM were calculated from these fitted functions. The VSM was validated against the PSF by comparing the doses calculated by the two methods for different square field sizes. The comparisons were performed with profile and gamma analyses. The doses calculated with the PSF and VSM agree to within 3% /1 mm (>95% pixel pass rate) for the evaluated fields. A new method of deriving a virtual photon source model of a linear accelerator from a PSF file for MC dose calculation was developed. Validation results show that the doses calculated with the VSM and the PSF agree to within 3% /1 mm.
A single-source photon source model of a linear accelerator for Monte Carlo dose calculation.
Directory of Open Access Journals (Sweden)
Obioma Nwankwo
Full Text Available To introduce a new method of deriving a virtual source model (VSM of a linear accelerator photon beam from a phase space file (PSF for Monte Carlo (MC dose calculation.A PSF of a 6 MV photon beam was generated by simulating the interactions of primary electrons with the relevant geometries of a Synergy linear accelerator (Elekta AB, Stockholm, Sweden and recording the particles that reach a plane 16 cm downstream the electron source. Probability distribution functions (PDFs for particle positions and energies were derived from the analysis of the PSF. These PDFs were implemented in the VSM using inverse transform sampling. To model particle directions, the phase space plane was divided into a regular square grid. Each element of the grid corresponds to an area of 1 mm2 in the phase space plane. The average direction cosines, Pearson correlation coefficient (PCC between photon energies and their direction cosines, as well as the PCC between the direction cosines were calculated for each grid element. Weighted polynomial surfaces were then fitted to these 2D data. The weights are used to correct for heteroscedasticity across the phase space bins. The directions of the particles created by the VSM were calculated from these fitted functions. The VSM was validated against the PSF by comparing the doses calculated by the two methods for different square field sizes. The comparisons were performed with profile and gamma analyses.The doses calculated with the PSF and VSM agree to within 3% /1 mm (>95% pixel pass rate for the evaluated fields.A new method of deriving a virtual photon source model of a linear accelerator from a PSF file for MC dose calculation was developed. Validation results show that the doses calculated with the VSM and the PSF agree to within 3% /1 mm.
Energy Technology Data Exchange (ETDEWEB)
Davidson, Scott E., E-mail: sedavids@utmb.edu [Radiation Oncology, The University of Texas Medical Branch, Galveston, Texas 77555 (United States); Cui, Jing [Radiation Oncology, University of Southern California, Los Angeles, California 90033 (United States); Kry, Stephen; Ibbott, Geoffrey S.; Followill, David S. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Deasy, Joseph O. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Vicic, Milos [Department of Applied Physics, University of Belgrade, Belgrade 11000 (Serbia); White, R. Allen [Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)
2016-08-15
Purpose: A dose calculation tool, which combines the accuracy of the dose planning method (DPM) Monte Carlo code and the versatility of a practical analytical multisource model, which was previously reported has been improved and validated for the Varian 6 and 10 MV linear accelerators (linacs). The calculation tool can be used to calculate doses in advanced clinical application studies. One shortcoming of current clinical trials that report dose from patient plans is the lack of a standardized dose calculation methodology. Because commercial treatment planning systems (TPSs) have their own dose calculation algorithms and the clinical trial participant who uses these systems is responsible for commissioning the beam model, variation exists in the reported calculated dose distributions. Today’s modern linac is manufactured to tight specifications so that variability within a linac model is quite low. The expectation is that a single dose calculation tool for a specific linac model can be used to accurately recalculate dose from patient plans that have been submitted to the clinical trial community from any institution. The calculation tool would provide for a more meaningful outcome analysis. Methods: The analytical source model was described by a primary point source, a secondary extra-focal source, and a contaminant electron source. Off-axis energy softening and fluence effects were also included. The additions of hyperbolic functions have been incorporated into the model to correct for the changes in output and in electron contamination with field size. A multileaf collimator (MLC) model is included to facilitate phantom and patient dose calculations. An offset to the MLC leaf positions was used to correct for the rudimentary assumed primary point source. Results: Dose calculations of the depth dose and profiles for field sizes 4 × 4 to 40 × 40 cm agree with measurement within 2% of the maximum dose or 2 mm distance to agreement (DTA) for 95% of the data
Energy Technology Data Exchange (ETDEWEB)
Hartley, Lee; Cox, Ian; Hunter, Fiona; Jackson, Peter; Joyce, Steve; Swift, Ben [Serco Assurance, Risley (United Kingdom); Gylling, Bjoern; Marsic, Niko [Kemakta Konsult AB, Stockholm (Sweden)
2005-05-01
The Swedish Nuclear Fuel and Waste Management Company (SKB) carries out site investigations in two different candidate areas in Sweden with the objective of describing the in-situ conditions for a bedrock repository for spent nuclear fuel. The site characterisation work is divided into two phases, an initial site investigation phase (IPLU) and a complete site investigation phase (KPLU). The results of IPLU are used as a basis for deciding on a subsequent KPLU phase. On the basis of the KPLU investigations a decision is made as to whether detailed characterisation will be performed (including sinking of a shaft). An integrated component in the site characterisation work is the development of site descriptive models. These comprise basic models in three dimensions with an accompanying text description. Central in the modelling work is the geological model, which provides the geometrical context in terms of a model of deformation zones and the rock mass between the zones. Using the geological and geometrical description models as a basis, descriptive models for other geo-disciplines (hydrogeology, hydro-geochemistry, rock mechanics, thermal properties and transport properties) will be developed. Great care is taken to arrive at a general consistency in the description of the various models and assessment of uncertainty and possible needs of alternative models. Here, a numerical model is developed on a regional-scale (hundreds of square kilometres) to understand the zone of influence for groundwater flow that affects the Forsmark area. Transport calculations are then performed by particle tracking from a local-scale release area (a few square kilometres) to identify potential discharge areas for the site and using greater grid resolution. The main objective of this study is to support the development of a preliminary Site Description of the Forsmark area on a regional-scale based on the available data of 30 June 2004 and the previous Site Description. A more specific
International Nuclear Information System (INIS)
MacDonald, P.E.; Broughton, J.M.
1975-03-01
Fuel pellets crack extensively upon irradiation due both to thermal stresses induced by power changes and at high burnup, to accumulation of gaseous fission products at grain boundaries. Therefore, the distance between the fuel and cladding will be circumferentially nonuniform; varying between that calculated for intact operating fuel pellets and essentially zero (fuel segments in contact with the cladding wall). A model for calculation of temperatures in cracked pellets is proposed wherein the effective fuel to cladding gap conductance is calculated by taking a zero pressure contact conductance in series with an annular gap conductance. Comparisons of predicted and measured fuel centerline temperatures at beginning of life and at extended burnup are presented in support of the model. 13 references
Calculations of the energy spectra of Zn, Ga and Ge isotopes by the shell model
International Nuclear Information System (INIS)
Sakakura, M.; Shikata, Y.; Arima, A.; Sebe, T.
1979-01-01
The effective Hamiltonian which was determined empirically by Koops and Glaudemans is tested in shell model calculations for the 65-68 Zn, 67-69 Ga, and 68-70 Ge nuclei in the full (1p 3 / 2 , 0f 5 / 2 , 1p 1 / 2 )n space. The resulting energy spectra are compared with the experimental spectra and results of previous calculations. The overall agreement with experiment is as satisfactory for these nuclei as for the Ni and Cu isotopes, by which the Hamiltonian was determined. It is noticed that the spectra of 67 Zn and 67 , 69 Ga calculated in this work are similar to those provided by the Alaga model. (orig.) [de
International Nuclear Information System (INIS)
Honda, M.; Kajita, T.; Kasahara, K.; Midorikawa, S.
2011-01-01
We present the calculation of the atmospheric neutrino fluxes with an interaction model named JAM, which is used in PHITS (Particle and Heavy-Ion Transport code System) [K. Niita et al., Radiation Measurements 41, 1080 (2006).]. The JAM interaction model agrees with the HARP experiment [H. Collaboration, Astropart. Phys. 30, 124 (2008).] a little better than DPMJET-III[S. Roesler, R. Engel, and J. Ranft, arXiv:hep-ph/0012252.]. After some modifications, it reproduces the muon flux below 1 GeV/c at balloon altitudes better than the modified DPMJET-III, which we used for the calculation of atmospheric neutrino flux in previous works [T. Sanuki, M. Honda, T. Kajita, K. Kasahara, and S. Midorikawa, Phys. Rev. D 75, 043005 (2007).][M. Honda, T. Kajita, K. Kasahara, S. Midorikawa, and T. Sanuki, Phys. Rev. D 75, 043006 (2007).]. Some improvements in the calculation of atmospheric neutrino flux are also reported.
Spin-splitting calculation for zincblende semiconductors using an atomic bond-orbital model
International Nuclear Information System (INIS)
Kao, Hsiu-Fen; Lo, Ikai; Chiang, Jih-Chen; Wang, Wan-Tsang; Hsu, Yu-Chi; Wu, Chieh-Lung; Gau, Ming-Hong; Chen, Chun-Nan; Ren, Chung-Yuan; Lee, Meng-En
2012-01-01
We develop a 16-band atomic bond-orbital model (16ABOM) to compute the spin splitting induced by bulk inversion asymmetry in zincblende materials. This model is derived from the linear combination of atomic-orbital (LCAO) scheme such that the characteristics of the real atomic orbitals can be preserved to calculate the spin splitting. The Hamiltonian of 16ABOM is based on a similarity transformation performed on the nearest-neighbor LCAO Hamiltonian with a second-order Taylor expansion over k-vector at the Γ point. The spin-splitting energies in bulk zincblende semiconductors, GaAs and InSb, are calculated, and the results agree with the LCAO and first-principles calculations. However, we find that the spin-orbit coupling between bonding and antibonding p-like states, evaluated by the 16ABOM, dominates the spin splitting of the lowest conduction bands in the zincblende materials.
Model calculations of the influence of population distribution on the siting of nuclear power plants
International Nuclear Information System (INIS)
Nielsen, F.; Walmod-Larsen, O.
1984-02-01
This report was prepared for a working group established in April 1981 by the Danish Environmental Protection Agency with the task of investigating siting problems of nuclear power stations in Denmark. The purpose of the working group was to study the influence of the population density around a site on nuclear power safety. The importance of emergency planning should be studied as well. In this model study two specific accident sequences were simulated on a 1000 MWe nuclear power plant. The plant was assumed to be placed in the center of two different model population distributions. The concequences for the two population distributions from the two accidents were calculated for the most frequent weather conditions. Doses to individuals were calculated for the bone marrow, lungs, gastrointestinal tract, thyroidea and for the whole body. The collective whole body doses were also calculated for the two populations considered. (author)
Application of the annular dispersed flow model to two-phase critical flow calculation
International Nuclear Information System (INIS)
Ivandaev, A.I.; Nigmatulin, B.I.
1977-01-01
The application of the annular dispersed flow model with an effective monodisperse core to the calculation of vapour-liquid mixture maximum rates through long pipes is discussed. An effect of the main dominant parameters such as evaporation intensity, diameter of drops picked out from the film surface and initial drop diameter at the pipe inlet on the outlet critical condition formation process has been investigated. The corresponding model constants have been determined. The calculated and experimental values of critical rates and pressure profiles along the channel have been found to be in a satisfactory agreement in the studied range of parameters. The observed non-conformity of the calculated and experimental values of critical pressures and vapour contents can be due to inadequate accuracy of the experimental techniques
Calculational model for condensation of water vapor during an underground nuclear detonation
International Nuclear Information System (INIS)
Knox, R.J.
1975-01-01
An empirally derived mathematical model was developed to calculate the pressure and temperature history during condensation of water vapor in an underground-nuclear-explosion cavity. The condensation process is non-isothermal. Use has been made of the Clapeyron-Clausius equation as a basis for development of the model. Analytic fits to the vapor pressure and the latent heat of vaporization for saturated-water vapor, together with an estimated value for the heat-transfer coefficient, have been used to describe the phenomena. The calculated pressure-history during condensation has been determined to be exponential, with a time constant somewhat less than that observed during the cooling of the superheated steam from the explosion. The behavior of the calculated condensation-pressure compares well with the observed-pressure record (until just prior to cavity collapse) for a particular nuclear-detonation event for which data is available
International Nuclear Information System (INIS)
Waegeneers, Nadia; Ruttens, Ann; De Temmerman, Ludwig
2011-01-01
A chain model was developed to calculate the flow of cadmium from soil, drinking water and feed towards bovine tissues. The data used for model development were tissue Cd concentrations of 57 bovines and Cd concentrations in soil, feed and drinking water, sampled at the farms were the bovines were reared. Validation of the model occurred with a second set of measured tissue Cd concentrations of 93 bovines of which age and farm location were known. The exposure part of the chain model consists of two parts: (1) a soil-plant transfer model, deriving cadmium concentrations in feed from basic soil characteristics (pH and organic matter content) and soil Cd concentrations, and (2) bovine intake calculations, based on typical feed and water consumption patterns for cattle and Cd concentrations in feed and drinking water. The output of the exposure model is an animal-specific average daily Cd intake, which is then taken forward to a kinetic uptake model in which time-dependent Cd concentrations in bovine tissues are calculated. The chain model was able to account for 65%, 42% and 32% of the variation in observed kidney, liver and meat Cd concentrations in the validation study. - Research highlights: → Cadmium transfer from soil, drinking water and feed to bovine tissues was modeled. → The model was based on 57 bovines and corresponding feed and soil Cd concentrations. → The model was validated with an independent data set of 93 bovines. → The model explained 65% of variation in kidney Cd in the validation study.
Modelling lateral beam quality variations in pencil kernel based photon dose calculations
International Nuclear Information System (INIS)
Nyholm, T; Olofsson, J; Ahnesjoe, A; Karlsson, M
2006-01-01
Standard treatment machines for external radiotherapy are designed to yield flat dose distributions at a representative treatment depth. The common method to reach this goal is to use a flattening filter to decrease the fluence in the centre of the beam. A side effect of this filtering is that the average energy of the beam is generally lower at a distance from the central axis, a phenomenon commonly referred to as off-axis softening. The off-axis softening results in a relative change in beam quality that is almost independent of machine brand and model. Central axis dose calculations using pencil beam kernels show no drastic loss in accuracy when the off-axis beam quality variations are neglected. However, for dose calculated at off-axis positions the effect should be considered, otherwise errors of several per cent can be introduced. This work proposes a method to explicitly include the effect of off-axis softening in pencil kernel based photon dose calculations for arbitrary positions in a radiation field. Variations of pencil kernel values are modelled through a generic relation between half value layer (HVL) thickness and off-axis position for standard treatment machines. The pencil kernel integration for dose calculation is performed through sampling of energy fluence and beam quality in sectors of concentric circles around the calculation point. The method is fully based on generic data and therefore does not require any specific measurements for characterization of the off-axis softening effect, provided that the machine performance is in agreement with the assumed HVL variations. The model is verified versus profile measurements at different depths and through a model self-consistency check, using the dose calculation model to estimate HVL values at off-axis positions. A comparison between calculated and measured profiles at different depths showed a maximum relative error of 4% without explicit modelling of off-axis softening. The maximum relative error
Comparison of Steady-State SVC Models in Load Flow Calculations
DEFF Research Database (Denmark)
Chen, Peiyuan; Chen, Zhe; Bak-Jensen, Birgitte
2008-01-01
This paper compares in a load flow calculation three existing steady-state models of static var compensator (SVC), i.e. the generator-fixed susceptance model, the total susceptance model and the firing angle model. The comparison is made in terms of the voltage at the SVC regulated bus, equivalent...... SVC susceptance at the fundamental frequency and the load flow convergence rate both when SVC is operating within and on the limits. The latter two models give inaccurate results of the equivalent SVC susceptance as compared to the generator model due to the assumption of constant voltage when the SVC...... is operating within the limits. This may underestimate or overestimate the SVC regulating capability. Two modified models are proposed to improve the SVC regulated voltage according to its steady-state characteristic. The simulation results of the two modified models show the improved accuracy...
Use of realistic anthropomorphic models for calculation of radiation dose in nuclear medicine
International Nuclear Information System (INIS)
Stabin, Michael G.; Emmons, Mary A.; Fernald, Michael J.; Brill, A.B.; Segars, W.Paul
2008-01-01
Anthropomorphic phantoms based on simple geometric structures have been used in radiation dose calculations for many years. We have now developed a series of anatomically realistic phantoms representing adults and children using body models based on non-uniform rational B-spline (NURBS), with organ and body masses based on the reference values given in ICRP Publication 89. Age-dependent models were scaled and shaped to represent the reference individuals described in ICRP 89 (male and female adults, newborns, 1-, 5-, 10- and 15-year-olds), using a software tool developed in Visual C++. Voxel-based versions of these models were used with GEANT4 radiation transport codes for calculation of specific absorbed fractions (SAFs) for internal sources of photons and electrons, using standard starting energy values. Organ masses in the models were within a few % of ICRP reference masses, and physicians reviewed the models for anatomical realism. Development of individual phantoms was much faster than manual segmentation of medical images, and resulted in a very uniform standardized phantom series. SAFs were calculated on the Vanderbilt multi node computing network (ACCRE). Photon and electron SAFs were calculated for all organs in all models, and were compared to values from similar phantoms developed by others. Agreement was very good in most cases; some differences were seen, due to differences in organ mass and geometry. This realistic phantom series represents a possible replacement for the Cristy/Eckerman series of the 1980's. Both phantom sets will be included in the next release of the OLINDA/EXM personal computer code, and the new phantoms will be made generally available to the research community for other uses. Calculated radiation doses for diagnostic and therapeutic radiopharmaceuticals will be compared with previous values. (author)
International Nuclear Information System (INIS)
Artemov, V.G.; Gusev, V.I.; Zinatullin, R.E.; Karpov, A.S.
2007-01-01
Using modeled WWER cram rod drop experiments, performed at the Rostov NPP, as an example, the influence of delayed neutron parameters on the modeling results was investigated. The delayed neutron parameter values were taken from both domestic and foreign nuclear databases. Numerical modeling was carried out on the basis of SAPFIR 9 5andWWERrogram package. Parameters of delayed neutrons were acquired from ENDF/B-VI and BNAB-78 validated data files. It was demonstrated that using delay fraction data from different databases in reactivity meters led to significantly different reactivity results. Based on the results of numerically modeled experiments, delayed neutron parameters providing the best agreement between calculated and measured data were selected and recommended for use in reactor calculations (Authors)
Energy Technology Data Exchange (ETDEWEB)
Solvang Jensen, S.; Loefstroem, P.; Berkowich, R.; Roerdam Olsen, H.; Frydendall, J. [DMU, Afd. for Atmosfaerisk Miljoe, Roskilde (DK); Fuglsang, K. [FORCE Technology, Broendby (Denmark); Hummelshoej, P. [MetSupport, Roskilde (Denmark)
2004-12-01
This report describes the air quality along Koege Bugt motorway, one of the most trafficked sections in Denmark. A number of measurements have been carried out along Koege Bugt motorway at Greve for a three-month period in the autumn of 2003. For the first time in Denmark, NO{sub x} were measured with high time dissolution from different distances of the motorway. Furthermore, a number of meteorological parameters were measured in order to map local meteorological conditions. An air quality model describing dispersal and conversion has been made on the basis of the OML model. The OML model is modified in order to take traffic-made turbulence into consideration. The model has been evaluated through comparisons between measurements and simulated calculations. Furthermore, simulated calculations for the year 2003 has been made for comparison with extreme values. (BA)
Calculation model for 16N transit time in the secondary side of steam generators
International Nuclear Information System (INIS)
Liu Songyu; Xu Jijun; Xu Ming
1998-01-01
The 16 N transit time is essential to determine the leak-rate of steam generator tubes leaks with 16 N monitoring system, which is a new technique. A model was developed for calculation 16 N transit time in the secondary side of steam generators. According to the flow characters of secondary side fluid, the transit times divide into four sectors from tube sheet to the sensor on steam line. The model assumes that 16 N is moving as vapor phase in the secondary-side. So the model for vapor velocity distribution in tube bundle is presented in detail. The 16 N transit time calculation results of this model compare with these of EDF on steam generator of Qinshan NPP
Calculations of Inflaton Decays and Reheating: with Applications to No-Scale Inflation Models
Ellis, John; Nanopoulos, Dimitri V; Olive, Keith A
2015-01-01
We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\\rm reh}$, and the number of inflationary e-folds, $N_*$, comparing analytical approximations with numerical calculations. We then illustrate these results with applications to models based on no-scale supergravity and motivated by generic string compactifications, including scenarios where the inflaton is identified as an untwisted-sector matter field with direct Yukawa couplings to MSSM fields, and where the inflaton decays via gravitational-strength interactions. Finally, we use our results to discuss the constraints on these models imposed by present measurements of the scalar spectral index $n_s$ and the tensor-to-scalar perturbation ratio $r$, converting them into constraints on $N_*$, the inflaton decay rate and other parameters of specific no-scale inflationary models.
International Nuclear Information System (INIS)
Pamela, J.
1990-10-01
Negative ion extraction is described by a model which includes electron diffusion across transverse magnetic fields in the sheath. This model allows a 2-Dimensional approximation of the problem. It is used to introduce electron space charge effects in a 2-D particle trajectory code, designed for negative ion optics calculations. Another physical effect, the stripping of negative ions on neutral gas atoms, has also been included in our model; it is found to play an important role in negative ion optics. The comparison with three sets of experimental data from very different negative ion accelerators, show that our model is able of accurate predictions
A new simulation model for calculating the internal exposure of some radionuclides
Directory of Open Access Journals (Sweden)
Mahrous Ayman
2009-01-01
Full Text Available A new model based on a series of mathematical functions for estimating excretion rates following the intake of nine different radionuclides is presented in this work. The radionuclides under investigation are: cobalt, iodine, cesium, strontium, ruthenium, radium, thorium, plutonium, and uranium. The committed effective dose has been calculated by our model so as to obtain the urinary and faecal excretion rates for each radionuclide. The said model is further validated by a comparison with the widely spread Mondal software and a simulation program. The results obtained show a harmony between the Mondal package and the model we have constructed.
Direct Monte Carlo dose calculation using polygon-surface computational human model
International Nuclear Information System (INIS)
Jeong, Jong Hwi; Kim, Chan Hyeong; Yeom, Yeon Su; Cho, Sungkoo; Chung, Min Suk; Cho, Kun-Woo
2011-01-01
In the present study, a voxel-type computational human model was converted to a polygon-surface model, after which it was imported directly to the Geant4 code without using a voxelization process, that is, without converting back to a voxel model. The original voxel model was also imported to the Geant4 code, in order to compare the calculated dose values and the computational speed. The average polygon size of the polygon-surface model was ∼0.5 cm 2 , whereas the voxel resolution of the voxel model was 1.981 × 1.981 × 2.0854 mm 3 . The results showed a good agreement between the calculated dose values of the two models. The polygon-surface model was, however, slower than the voxel model by a factor of 6–9 for the photon energies and irradiation geometries considered in the present study, which nonetheless is considered acceptable, considering that direct use of the polygon-surface model does not require a separate voxelization process. (author)
One kind of atmosphere-ocean three layer model for calculating the velocity of ocean current
Energy Technology Data Exchange (ETDEWEB)
Jing, Z; Xi, P
1979-10-01
A three-layer atmosphere-ocean model is given in this paper to calcuate the velocity of ocean current, particularly the function of the vertical coordinate, taking into consideratiln (1) the atmospheric effect on the generation of ocean current, (2) a calculated coefficient of the eddy viscosity instead of an assumed one, and (3) the sea which actually varies in depth.
Ab initio calculation of the sound velocity of dense hydrogen: implications for models of Jupiter
Alavi, A.; Parrinello, M.; Frenkel, D.
1995-01-01
First-principles molecular dynamics simulations were used to calculate the sound velocity of dense hydrogen, and the results were compared with extrapolations of experimental data that currently conflict with either astrophysical models or data obtained from recent global oscillation measurements of
A new timing model for calculating the intrinsic timing resolution of a scintillator detector
International Nuclear Information System (INIS)
Shao Yiping
2007-01-01
The coincidence timing resolution is a critical parameter which to a large extent determines the system performance of positron emission tomography (PET). This is particularly true for time-of-flight (TOF) PET that requires an excellent coincidence timing resolution (<<1 ns) in order to significantly improve the image quality. The intrinsic timing resolution is conventionally calculated with a single-exponential timing model that includes two parameters of a scintillator detector: scintillation decay time and total photoelectron yield from the photon-electron conversion. However, this calculation has led to significant errors when the coincidence timing resolution reaches 1 ns or less. In this paper, a bi-exponential timing model is derived and evaluated. The new timing model includes an additional parameter of a scintillator detector: scintillation rise time. The effect of rise time on the timing resolution has been investigated analytically, and the results reveal that the rise time can significantly change the timing resolution of fast scintillators that have short decay time constants. Compared with measured data, the calculations have shown that the new timing model significantly improves the accuracy in the calculation of timing resolutions
The one loop calculation of the strong coupling β function in the Toy Model
International Nuclear Information System (INIS)
Bai Zhiming; Jiang Yuanfang
1991-01-01
The background field quantization is used to calculate the one-loop β function in the Toy Model which has the strong coupling and the SU(3) symmetry. The function obtained is consistent with the Appalquist-Carrazone theorem in the low energy condition
Raman Spectroscopy and Ab-Initio Model Calculations on Ionic Liquids
DEFF Research Database (Denmark)
Berg, Rolf W.
2007-01-01
spectroscopy and ab-initio molecular orbital calculations. A discussion is given, based mainly on some recent FT-Raman spectroscopic results on the model ionic liquid system of 1-butyl-3-methylimidazolium ([C4mim][X]) salts. The rotational isomerism of the [C4mim]þ cation is described: the presence of anti...
Calculation of spherical models of lead with a source of 14 MeV-neutrons
International Nuclear Information System (INIS)
Markovskij, D.V.; Borisov, A.A.
1989-01-01
Neutron transport calculations for spherical models of lead have been done with the one-dimensional code BLANK realizing the direct Monte Carlo method in the whole range of neutron energies and they are compared with the experimental results. 6 refs, 10 figs, 3 tabs
Covariance matrices for nuclear cross sections derived from nuclear model calculations
International Nuclear Information System (INIS)
Smith, D. L.
2005-01-01
The growing need for covariance information to accompany the evaluated cross section data libraries utilized in contemporary nuclear applications is spurring the development of new methods to provide this information. Many of the current general purpose libraries of evaluated nuclear data used in applications are derived either almost entirely from nuclear model calculations or from nuclear model calculations benchmarked by available experimental data. Consequently, a consistent method for generating covariance information under these circumstances is required. This report discusses a new approach to producing covariance matrices for cross sections calculated using nuclear models. The present method involves establishing uncertainty information for the underlying parameters of nuclear models used in the calculations and then propagating these uncertainties through to the derived cross sections and related nuclear quantities by means of a Monte Carlo technique rather than the more conventional matrix error propagation approach used in some alternative methods. The formalism to be used in such analyses is discussed in this report along with various issues and caveats that need to be considered in order to proceed with a practical implementation of the methodology
Shell-model calculations with a basis that contains correlated pairs
International Nuclear Information System (INIS)
Boisson, J.P.; Silvestre-Brac, B.A.; Liotta, R.J.
1979-01-01
A method to solve the shell-model equations within a basis that contains correlated pairs of particles is presented. The method is illustrated for the three-identical-particle system. Applications in nuclei around 208 Pb are given and comparisons with both experimental data and other calculations are carried out. (Auth.)
Black Hole Entropy Calculation in a Modified Thin Film Model Jingyi ...
Indian Academy of Sciences (India)
Abstract. The thin film model is modified to calculate the black hole entropy. The difference from the original method is that the Parikh–. Wilczek tunnelling framework is introduced and the self-gravitation of the emission particles is taken into account. In terms of our improvement, if the entropy is still proportional to the area, ...
Model-Independent Calculation of Radiative Neutron Capture on Lithium-7
Rupak, Gautam; Higa, Renato
2011-01-01
The radiative neutron capture on lithium-7 is calculated model independently using a low-energy halo effective field theory. The cross section is expressed in terms of scattering parameters directly related to the S-matrix elements. It depends on the poorly known p-wave effective range parameter
Large scale shell model calculations: the physics in and the physics out
International Nuclear Information System (INIS)
Zuker, A.P.
1997-01-01
After giving a few examples of recent results of the (SM) 2 collaboration, the monopole modified realistic interactions to be used in shell model calculations are described and analyzed. Rotational motion is discussed in some detail, and some introductory remarks on level densities are made. (orig.)
Seldam, C.A. ten; Groot, S.R. de
1952-01-01
From Jensen's and Gombás' modification of the statistical Thomas-Fermi atom model, a theory for compressed atoms is developed by changing the boundary conditions. Internal kinetic energy and polarizability of argon are calculated as functions of pressure. At 1000 atm. an internal kinetic energy of
Progress in the improved lattice calculation of direct CP-violation in the Standard Model
Kelly, Christopher
2018-03-01
We discuss the ongoing effort by the RBC & UKQCD collaborations to improve our lattice calculation of the measure of Standard Model direct CP violation, ɛ', with physical kinematics. We present our progress in decreasing the (dominant) statistical error and discuss other related activities aimed at reducing the systematic errors.
International Nuclear Information System (INIS)
Lee, J. K.; Naganuma, M.
2006-01-01
Gas cooled Fast Reactor (GFR) is being researched as a candidate concept of Generation IV international Forum. As a main feature of GFR, it should be maintained high temperature and pressure of coolant gas for heat transfer efficiency. Such a demanding environment requires high-temperature-resistant structural materials distinguished from traditional steel material. Consequently, ceramics are promising candidate material of core components. Especially, Silicon Carbide fiber reinforced Silicon Carbide composites (SiC/SiC) have encouraging characteristics such as refractoriness, low activation and toughness. Application of new material to core components must be explained by the viewpoint of engineering validity. Therefore, present study surveyed that current report for mechanical strength and thermal conductivity of SiC/SiC composites. According to the reports, neutron irradiation environment degraded mechanical properties of SiC/SiC composites. To confirm applicability to core components, model of fuel pin using SiC/SiC composites was assumed with feasible mechanical properties. Furthermore, it was calculated and estimated that the stress caused by temperature variation of inner and outer side of assumed model of cladding tube. Stress was calculated by changing of input date such as thickness of cladding tube, temperature variation, thermal conductivity and linear power. In the range of this study, the most important factor was identified as degradation of thermal conductivity by irradiation. It caused a significant stress and limited a geometrical design of fuel pin. It was discussed that the differences of heat transfer between isotropic and anisotropic materials like a metal and composites. These results should be helpful not only to determine a design factor of core component but also to indicate an improvement direction of SiC/SiC composites. Through these work, reliability and safety of GFR will be increased
Abramopoulos, F.; Rosenzweig, C.; Choudhury, B.
1988-09-01
A physically based ground hydrology model is developed to improve the land-surface sensible and latent heat calculations in global climate models (GCMs). The processes of transpiration, evaporation from intercepted precipitation and dew, evaporation from bare soil, infiltration, soil water flow, and runoff are explicitly included in the model. The amount of detail in the hydrologic calculations is restricted to a level appropriate for use in a GCM, but each of the aforementioned processes is modeled on the basis of the underlying physical principles. Data from the Goddard Institute for Space Studies (GISS) GCM are used as inputs for off-line tests of the ground hydrology model in four 8° × 10° regions (Brazil, Sahel, Sahara, and India). Soil and vegetation input parameters are calculated as area-weighted means over the 8° × 10° gridhox. This compositing procedure is tested by comparing resulting hydrological quantities to ground hydrology model calculations performed on the 1° × 1° cells which comprise the 8° × 10° gridbox. Results show that the compositing procedure works well except in the Sahel where lower soil water levels and a heterogeneous land surface produce more variability in hydrological quantities, indicating that a resolution better than 8° × 10° is needed for that region. Modeled annual and diurnal hydrological cycles compare well with observations for Brazil, where real world data are available. The sensitivity of the ground hydrology model to several of its input parameters was tested; it was found to be most sensitive to the fraction of land covered by vegetation and least sensitive to the soil hydraulic conductivity and matric potential.
A three-dimensional model for calculating the micro disk laser resonant-modes
International Nuclear Information System (INIS)
Sabetjoo, H.; Bahrampor, A.; Farrahi-Moghaddam, R.
2006-01-01
In this article, a semi-analytical model for theoretical analysis of micro disk lasers is presented. Using this model, the necessary conditions for the existence of loss less and low-loss modes of micro-resonators are obtained. The resonance frequency of the resonant modes and also the attenuation of low-loss modes are calculated. By comparing the results with results of finite difference method, their validity is certified.
Beriro, D. J.; Abrahart, R. J.; Nathanail, C. P.
2012-04-01
Data-driven modelling is most commonly used to develop predictive models that will simulate natural processes. This paper, in contrast, uses Gene Expression Programming (GEP) to construct two alternative models of different pan evaporation estimations by means of symbolic regression: a simulator, a model of a real-world process developed on observed records, and an emulator, an imitator of some other model developed on predicted outputs calculated by that source model. The solutions are compared and contrasted for the purposes of determining whether any substantial differences exist between either option. This analysis will address recent arguments over the impact of using downloaded hydrological modelling datasets originating from different initial sources i.e. observed or calculated. These differences can be easily be overlooked by modellers, resulting in a model of a model developed on estimations derived from deterministic empirical equations and producing exceptionally high goodness-of-fit. This paper uses different lines-of-evidence to evaluate model output and in so doing paves the way for a new protocol in machine learning applications. Transparent modelling tools such as symbolic regression offer huge potential for explaining stochastic processes, however, the basic tenets of data quality and recourse to first principles with regard to problem understanding should not be trivialised. GEP is found to be an effective tool for the prediction of observed and calculated pan evaporation, with results supported by an understanding of the records, and of the natural processes concerned, evaluated using one-at-a-time response function sensitivity analysis. The results show that both architectures and response functions are very similar, implying that previously observed differences in goodness-of-fit can be explained by whether models are applied to observed or calculated data.
Energy Technology Data Exchange (ETDEWEB)
Hermanson, Jan; Forssberg, Ola [Golder Associates AB, Stockholm (Sweden); Fox, Aaron; La Pointe, Paul [Golder Associates Inc., Redmond, WA (United States)
2005-10-15
The goal of this summary report is to document the data sources, software tools, experimental methods, assumptions, and model parameters in the discrete-fracture network (DFN) model for the local model volume in Laxemar, version 1.2. The model parameters presented herein are intended for use by other project modeling teams. Individual modeling teams may elect to simplify or use only a portion of the DFN model, depending on their needs. This model is not intended to be a flow model or a mechanical model; as such, only the geometrical characterization is presented. The derivations of the hydraulic or mechanical properties of the fractures or their subsurface connectivities are not within the scope of this report. This model represents analyses carried out on particular data sets. If additional data are obtained, or values for existing data are changed or excluded, the conclusions reached in this report, and the parameter values calculated, may change as well. The model volume is divided into two subareas; one located on the Simpevarp peninsula adjacent to the power plant (Simpevarp), and one further to the west (Laxemar). The DFN parameters described in this report were determined by analysis of data collected within the local model volume. As such, the final DFN model is only valid within this local model volume and the modeling subareas (Laxemar and Simpevarp) within.
Preliminary assessment of the performance of a global coupled atmosphere-ocean model
International Nuclear Information System (INIS)
Cubasch, U.
1990-01-01
A low-resolution version of the ECMWF global atmosphere model has been coupled to a global ocean model developed at the Max Planck Institute in Hamburg. The atmosphere model is driven by the sea surface temperature and the ice thickness calculated by the ocean model, which, in return, is driven by the wind stress, the heat flux and the freshwater flux diagnosed by the atmosphere model. Even though each model reaches stationarity when integrated on its own, the coupling of both creates problems, since the fields calculated by each model are not consistent with the ones the other model has to have in order to stay stationary, because some of the fluxes are not balanced. In the coupled experiment the combined ocean-atmosphere system drifts toward a colder state. To counteract this problem, a flux correction has been applied which balances the mean biases of each model. This method almost eliminates the climate drift of the coupled model. Problems still arise over ice covered regions
Energy Technology Data Exchange (ETDEWEB)
1992-12-29
This volume documents model parameters chosen as of July 1992 that were used by the Performance Assessment Department of Sandia National Laboratories in its 1992 preliminary performance assessment of the Waste Isolation Pilot Plant (WIPP). Ranges and distributions for about 300 modeling parameters in the current secondary data base are presented in tables for the geologic and engineered barriers, global materials (e.g., fluid properties), and agents that act upon the WIPP disposal system such as climate variability and human-intrusion boreholes. The 49 parameters sampled in the 1992 Preliminary Performance Assessment are given special emphasis with tables and graphics that provide insight and sources of data for each parameter.
A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions
International Nuclear Information System (INIS)
Watson, E.E.; Stabin, M.G.
1987-01-01
Existing models which allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs.; 2 figs
A mathematical model of the nine-month pregnant woman for calculating specific absorbed fractions
International Nuclear Information System (INIS)
Watson, E.E.; Stabin, M.G.
1986-01-01
Existing models that allow calculation of internal doses from radionuclide intakes by both men and women are based on a mathematical model of Reference Man. No attempt has been made to allow for the changing geometric relationships that occur during pregnancy which would affect the doses to the mother's organs and to the fetus. As pregnancy progresses, many of the mother's abdominal organs are repositioned, and their shapes may be somewhat changed. Estimation of specific absorbed fractions requires that existing mathematical models be modified to accommodate these changes. Specific absorbed fractions for Reference Woman at three, six, and nine months of pregnancy should be sufficient for estimating the doses to the pregnant woman and the fetus. This report describes a model for the pregnant woman at nine months. An enlarged uterus was incorporated into a model for Reference Woman. Several abdominal organs as well as the exterior of the trunk were modified to accommodate the new uterus. This model will allow calculation of specific absorbed fractions for the fetus from photon emitters in maternal organs. Specific absorbed fractions for the repositioned maternal organs from other organs can also be calculated. 14 refs., 2 figs
Anderson, Christine A; Whall, Ann L
2013-10-01
Opinion leaders are informal leaders who have the ability to influence others' decisions about adopting new products, practices or ideas. In the healthcare setting, the importance of translating new research evidence into practice has led to interest in understanding how opinion leaders could be used to speed this process. Despite continued interest, gaps in understanding opinion leadership remain. Agent-based models are computer models that have proven to be useful for representing dynamic and contextual phenomena such as opinion leadership. The purpose of this paper is to describe the work conducted in preparation for the development of an agent-based model of nursing opinion leadership. The aim of this phase of the model development project was to clarify basic assumptions about opinions, the individual attributes of opinion leaders and characteristics of the context in which they are effective. The process used to clarify these assumptions was the construction of a preliminary nursing opinion leader model, derived from philosophical theories about belief formation. © 2013 John Wiley & Sons Ltd.
Wanna, S. B. C.; Basaruddin, K. S.; Mat Som, M. H.; Mohamad Hashim, M. S.; Daud, R.; Majid, M. S. Abdul; Sulaiman, A. R.
2017-10-01
Osteogenesis imperfecta (OI) is a genetic disease which affecting the bone geometry. In a severe case, this disease can cause death to patients. The main issue of this disease is the prediction on bone fracture by the orthopaedic surgeons. The resistance of the bone to withstand the force before the bones fracture often become the main concern. Therefore, the objective of the present preliminary study was to investigate the fracture risk associated with OI bone, particularly in femur, when subjected to the self-weight. Finite element (FEA) was employed to reconstruct the OI bone model and analyse the mechanical stress response of femur before it fractures. Ten deformed models with different severity of OI bones were developed and the force that represents patient self-weight was applied to the reconstructed models in static analysis. Stress and fracture risk were observed and analysed throughout the simulation. None of the deformed model were observed experienced fracture. The fracture risk increased with increased severity of the deformed bone. The results showed that all deformed femur models were able to bear the force without experienced fracture when subjected to only the self-weight.
Fahrul Hassan, Mohd; Rahman, M. R. A.; Arifin, A. M. T.; Ismail, A. E.; Rasidi Ibrahim, M.; Zulafif Rahim, M.; Fauzi Ahmad, Md
2017-08-01
Product manufactured with short life cycle had only one major issue, it can lead to increasing volume of waste. Day by day, this untreated waste had consumed many landfill spaces, waiting for any possible alternatives. Lack of product recovery knowledge and recyclability features imprinted into product design are one of the main reason behind all this. Sustainable awareness aspect should not just be implied into people’s mind, but also onto product design. This paper presents a preliminary study on Kano model method in the conceptual design activities to improve product lifecycle. Kano model is a survey-type method, used to analyze and distinguished product qualities or features, also how the customers may have perceived them. Three important attributes of Kano model are performance, attractive and must-be. The proposed approach enables better understanding of customer requirements while providing a way for Kano model to be integrated into engineering design to improve product’s end-of-life. Further works will be continued to provide a better lifecycle option (increase percentage of reuse, remanufacture or recycle, whereby decrease percentage of waste) of a product using Kano model approach.
Directory of Open Access Journals (Sweden)
Ernesto Amato
2014-03-01
Full Text Available We developed a general model for the calculation of absorbed fractions in ellipsoidal volumes of soft tissue uniformly filled with alpha, beta and gamma emitting radionuclides. The approach exploited Monte Carlo simulations with the Geant4 code to determine absorbed fractions in ellipsoids characterized by a wide range of dimensions and ellipticities, for monoenergetic emissions of each radiation type. The so-obtained absorbed fractions were put in an analytical relationship with the 'generalized radius', calculated as 3V/S, where V is the ellipsoid volume and S its surface. Radiation-specific parametric functions were obtained in order to calculate the absorbed fraction of a given radiation in a generic ellipsoidal volume. The dose from a generic radionuclide can be calculated through a process of summation and integration over the whole radionuclide emission spectrum, profitably implemented in an electronic spreadsheet. We compared the results of our analytical calculation approach with those obtained from the OLINDA/EXM computer software, finding a good agreement in a wide range of sphere radii, for the high-energy pure beta emitter 90Y, the commonly employed beta-gamma emitter 131I, and the pure alpha emitter 213Po. The generality of our approach makes it useful an easy to implement in clinical dosimetry calculations as well as in radiation safety estimations when doses from internal radionuclide uptake are to be taken into account.
NFAP calculation of the response of a 1/6 scale reinforced concrete containment model
International Nuclear Information System (INIS)
Costantino, C.J.; Pepper, S.; Reich, M.
1989-01-01
The details associated with the NFAP calculation of the pressure response of the 1/6th scale model containment structure are discussed in this paper. Comparisons are presented of some of the primary items of interest with those determined from the experiment. It was found from this comparison that the hoop response of the containment wall was adequately predicted by the NFAP finite element calculation, including the response in the high pressure, high strain range at which cracking of the concrete and yielding of the hoop reinforcement occurred. In the vertical or meridional direction, it was found that the model was significantly softer than predicted by the finite element calculation; that is, the vertical strains in the test were three to four times larger than computed in the NFAP calculation. These differences were noted even at low strain levels at which the concrete would not be expected to be cracked under tensile loadings. Simplified calculations for the containment indicate that the vertical stiffness of the wall is similar to that which would be determined by assuming the concrete fully cracked. Thus, the experiment indicates an anomalous behavior in the vertical direction
NFAP calculation of pressure response of 1/6th scale model containment structure
International Nuclear Information System (INIS)
Costantino, C.J.; Pepper, S.; Reich, M.
1988-01-01
The details associated with the NFAP calculation of the pressure response of the 1/6th scale model containment structure are discussed in this paper. Comparisons are presented of some of the primary items of interest with those determined from the experiment. It was found from this comparison that the hoop response of the containment wall was adequately predicted by the NFAP finite element calculation, including the response in the high pressure, high strain range at which cracking of the concrete and yielding of the hoop reinforcement occurred. In the vertical or meridional direction, it was found that the model was significantly softer than predicted by the finite element calculation; that is, the vertical strains in the test were three to four times larger than computed in the NFAP calculation. These differences were noted even at low strain levels at which the concrete would not be expected to be cracked under tensile loadings. Simplified calculations for the containment indicate that the vertical stiffness of the wall is similar to that which would be determined by assuming the concrete fully cracked. Thus, the experiment indicates an anomalous behavior in the vertical direction
Merker, L.; Costi, T. A.
2012-08-01
We introduce a method to obtain the specific heat of quantum impurity models via a direct calculation of the impurity internal energy requiring only the evaluation of local quantities within a single numerical renormalization group (NRG) calculation for the total system. For the Anderson impurity model we show that the impurity internal energy can be expressed as a sum of purely local static correlation functions and a term that involves also the impurity Green function. The temperature dependence of the latter can be neglected in many cases, thereby allowing the impurity specific heat Cimp to be calculated accurately from local static correlation functions; specifically via Cimp=(∂Eionic)/(∂T)+(1)/(2)(∂Ehyb)/(∂T), where Eionic and Ehyb are the energies of the (embedded) impurity and the hybridization energy, respectively. The term involving the Green function can also be evaluated in cases where its temperature dependence is non-negligible, adding an extra term to Cimp. For the nondegenerate Anderson impurity model, we show by comparison with exact Bethe ansatz calculations that the results recover accurately both the Kondo induced peak in the specific heat at low temperatures as well as the high-temperature peak due to the resonant level. The approach applies to multiorbital and multichannel Anderson impurity models with arbitrary local Coulomb interactions. An application to the Ohmic two-state system and the anisotropic Kondo model is also given, with comparisons to Bethe ansatz calculations. The approach could also be of interest within other impurity solvers, for example, within quantum Monte Carlo techniques.
Addicted to Pain: A Preliminary Model of Sexual Masochism as Addiction.
Kurt, Holly; Ronel, Natti
2017-11-01
An exploratory, qualitative, phenomenological study focused on the experience of pain while participating in sexual masochistic acts. Semi-structured interviews were conducted with nine individuals (four female, five male) who regularly participate in sexually masochistic acts and point to pain as central to their experience. Qualitative analysis of the data revealed several key characteristics of the participant's experience: the first time, intoxication, craving and withdrawal, tolerance, pain as control, and the pain inducing partner. The findings indicate that the way pain is experienced while mitigated through masochistic behavior creates an addictive process that coincides with a chronic behavioral spin contextualization. This article presents a preliminary model of addiction to physical pain in light of the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) definition of substance-related and addictive disorders and the behavioral spin theory.
Modeling and preliminary thermal analysis of the capsule for a creep test in HANARO
International Nuclear Information System (INIS)
Choi, Myoung Hwan; Cho, Man Soon; Choo, Kee Nam; Kang, Young Hwan; Sohn, Jae Min; Shin, Yoon Taeg; Park, Sung Jae; Kim, Bong Goo; Kim, Young Jin
2005-01-01
A creep capsule is a device to investigate the creep characteristics of nuclear materials during inpile irradiation tests. To obtain the design data of the capsule through a preliminary thermal analysis, a 2-dimensional model for the cross section of the capsule including the specimens and components is generated, and an analysis using the ANSYS program is performed. The gamma-heating rates of the materials for the HANARO power of 30MW are considered, and the effect of the gap size and the control rod position on the temperature of the specimen is discussed. From the analysis it is found that the gap between the thermal media and the external tube has a significant effect on the temperature of the specimen. The temperature by increasing the position of the control rod is decreased
Recent developments in biokinetic models and the calculation of internal dose coefficients
International Nuclear Information System (INIS)
Fell, T.P.; Phipps, A.W.; Kendall, G.M.; Stradling, G.N.
1997-01-01
In most cases the measurement of radioactivity in an environmental or biological sample will be followed by some estimation of dose and possibly risk, either to a population or an individual. This will normally involve the use of a dose coefficient (dose per unit intake value) taken from a compendium. In recent years the calculation of dose coefficients has seen many developments in both biokinetic modelling and computational capabilities. ICRP has recommended new models for the respiratory tract and for the systemic behavior of many of the more important elements. As well as this, a general age-dependent calculation method has been developed which involves an effectively continuous variation of both biokinetic and dosimetric parameters, facilitating more realistic estimation of doses to young people. These new developments were used in work for recent ICRP, IAEA and CEC compendia of dose coefficients for both members of the public (including children) and workers. This paper presents a general overview of the method of calculation of internal doses with particular reference to the actinides. Some of the implications for dose coefficients of the new models are discussed. For example it is shown that compared with data in ICRP Publications 30 and 54: the new respiratory tract model generally predicts lower deposition in systemic tissues per unit intake; the new biokinetic models for actinides allow for burial of material deposited on bone surfaces; age-dependent models generally feature faster turnover of material in young people. All of these factors can lead to substantially different estimates of dose and examples of the new dose coefficients are given to illustrate these differences. During the development of the new models for actinides, human bioassay data were used to validate the model. Thus, one would expect the new models to give reasonable predictions of bioassay quantities. Some examples of the bioassay applications, e.g., excretion data for the
Sarkadi, L.
2018-04-01
Fully differential cross sections (FDCSs) have been calculated for the single ionization of helium by 1- and 3-MeV proton and 100-MeV/u C6 + ion impact using the classical trajectory Monte Carlo (CTMC) method in the nonrelativistic, three-body approximation. The calculations were made employing a Wigner-type model in which the quantum-mechanical position distribution of the electron is approximated by a weighted integral of the microcanonical distribution over a range of the binding energy of the electron. In the scattering plane, the model satisfactorily reproduces the observed shape of the binary peak. In the region of the peak the calculated FDCSs agree well with the results of continuum-distorted-wave calculations for all the investigated collisions. For 1-MeV proton impact the experimentally observed shift of the binary peak with respect to the first Born approximation is compared with the shifts obtained by different higher-order quantum-mechanical theories and the present CTMC method. The best result was achieved by CTMC, but still a large part of the shift remained unexplained. Furthermore, it was found that the classical theory failed to reproduce the shape of the recoil peak observed in the experiments, it predicts a much narrower peak. This indicates that the formation of the recoil peak is dominated by quantum-mechanical effects. For 100-MeV/u C6 + ion impact the present CTMC calculations confirmed the existence of the "double-peak" structure of the angular distribution of the electron in the plane perpendicular to the momentum transfer, in accordance with the observation, the prediction of an incoherent semiclassical model, and previous CTMC results. This finding together with wave-packet calculations suggests that the "C6 + puzzle" may be solved by considering the loss of the projectile coherence. Experiments to be conducted using ion beams of anisotropic coherence are proposed for a more differential investigation of the ionization dynamics.
Generic model for calculating carbon footprint of milk using four different LCA modelling approaches
DEFF Research Database (Denmark)
Dalgaard, Randi; Schmidt, Jannick Højrup; Flysjö, Anna
2014-01-01
The aim of the study is to develop a tool, which can be used for calculation of carbon footprint (using a life cycle assessment (LCA) approach) of milk both at a farm level and at a national level. The functional unit is ‘1 kg energy corrected milk (ECM) at farm gate’ and the applied methodology...
On the stress calculation within phase-field approaches: a model for finite deformations
Schneider, Daniel; Schwab, Felix; Schoof, Ephraim; Reiter, Andreas; Herrmann, Christoph; Selzer, Michael; Böhlke, Thomas; Nestler, Britta
2017-08-01
Numerical simulations based on phase-field methods are indispensable in order to investigate interesting and important phenomena in the evolution of microstructures. Microscopic phase transitions are highly affected by mechanical driving forces and therefore the accurate calculation of the stresses in the transition region is essential. We present a method for stress calculations within the phase-field framework, which satisfies the mechanical jump conditions corresponding to sharp interfaces, although the sharp interface is represented as a volumetric region using the phase-field approach. This model is formulated for finite deformations, is independent of constitutive laws, and allows using any type of phase inherent inelastic strains.
Effect of film roughness in Fe/MgO/Fe magnetic tunnel junctions: model calculations
Energy Technology Data Exchange (ETDEWEB)
Edalati Boostan, Saeideh; Heiliger, Christian [I. Physikalisches Institut, Justus Liebig University Giessen, D-35392 (Germany); Moradi, Hosein [Department of Physics,Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)
2011-07-01
We calculate how interface roughness affects the tunneling magnetoresistance (TMR) in Fe/MgO/Fe (100) junctions. The used method is based on a single-band tight-binding (SBTB) approximation employing the Green's function formalism. We investigate the influence of disorder at the TMR ratio. Thereby, the disorder is modeled by considering different occupation probabilities of Fe and MgO at interface sites. We calculate the current densities for parallel and anti-parallel configurations for different disorders. The results show that the roughness decreases the TMR that match well with experimental observations.
International Nuclear Information System (INIS)
Strenge, D.L.; Watson, E.C.; Droppo, J.G.
1976-06-01
The development of technological bases for siting nuclear fuel cycle facilities requires calculational models and computer codes for the evaluation of risks and the assessment of environmental impact of radioactive effluents. A literature search and review of available computer programs revealed that no one program was capable of performing all of the great variety of calculations (i.e., external dose, internal dose, population dose, chronic release, accidental release, etc.). Available literature on existing computer programs has been reviewed and a description of each program reviewed is given
Energy Technology Data Exchange (ETDEWEB)
Strenge, D.L.; Watson, E.C.; Droppo, J.G.
1976-06-01
The development of technological bases for siting nuclear fuel cycle facilities requires calculational models and computer codes for the evaluation of risks and the assessment of environmental impact of radioactive effluents. A literature search and review of available computer programs revealed that no one program was capable of performing all of the great variety of calculations (i.e., external dose, internal dose, population dose, chronic release, accidental release, etc.). Available literature on existing computer programs has been reviewed and a description of each program reviewed is given.
International Nuclear Information System (INIS)
Androsenko, A.A.; Androsenko, P.A.; Deeva, V.V.; Prokof'eva, Z.A.
1990-01-01
Analysis is made for the effect of mathematical model accuracy of the system concerned on the calculation results using the BRAND program system. Consideration is given to the impact of the following factors: accuracy of neutron source energy-angular characteristics description, various degrees of system geometry approximation, adequacy of Monte-Carlo method estimation to a real physical neutron detector. The calculation results analysis is made on the basis of the experiments on leakage neutron spectra measurement in spherical lead assemblies with the 14 MeV-neutron source in the centre. 4 refs.; 2 figs.; 10 tabs
Bimodality emerges from transport model calculations of heavy ion collisions at intermediate energy
Mallik, S.; Das Gupta, S.; Chaudhuri, G.
2016-04-01
This work is a continuation of our effort [S. Mallik, S. Das Gupta, and G. Chaudhuri, Phys. Rev. C 91, 034616 (2015)], 10.1103/PhysRevC.91.034616 to examine if signatures of a phase transition can be extracted from transport model calculations of heavy ion collisions at intermediate energy. A signature of first-order phase transition is the appearance of a bimodal distribution in Pm(k ) in finite systems. Here Pm(k ) is the probability that the maximum of the multiplicity distribution occurs at mass number k . Using a well-known model for event generation [Botzmann-Uehling-Uhlenbeck (BUU) plus fluctuation], we study two cases of central collision: mass 40 on mass 40 and mass 120 on mass 120. Bimodality is seen in both the cases. The results are quite similar to those obtained in statistical model calculations. An intriguing feature is seen. We observe that at the energy where bimodality occurs, other phase-transition-like signatures appear. There are breaks in certain first-order derivatives. We then examine if such breaks appear in standard BUU calculations without fluctuations. They do. The implication is interesting. If first-order phase transition occurs, it may be possible to recognize that from ordinary BUU calculations. Probably the reason this has not been seen already is because this aspect was not investigated before.
Directory of Open Access Journals (Sweden)
Tomasz Topoliński
2012-01-01
Full Text Available Trabecular bone cores were collected from the femoral head at the time of surgery (hip arthroplasty. Investigated were 42 specimens, from patients with osteoporosis and coxarthrosis. The cores were scanned used computer microtomography (microCT system at an isotropic spatial resolution of 36 microns. Image stacks were converted to finite element models via a bone voxel-to-element algorithm. The apparent modulus was calculated based on the assumptions that for the elastic properties, E=10 MPa and ν=0.3. The compressive deformation as calculated by finite elements (FE analysis was 0.8%. The models were coarsened to effectively change the resolution or voxel size (from 72 microns to 288 microns or from 72 microns to 1080 microns. The aim of our study is to determine how an increase in the distance between scans changes the elastic properties as calculated by FE models. We tried to find a border value voxel size at which the module values were possible to calculate. As the voxel size increased, the mean voxel volume increased and the FEA-derived apparent modulus decreased. The slope of voxel size versus modulus relationship correlated with several architectural indices of trabecular bone.
A model for the calculation of the radiation dose from natural radionuclides in The Netherlands
International Nuclear Information System (INIS)
Ackers, J.G.
1986-02-01
A model has been developed to calculate the radiation dose incurred from natural radioactivity indoors and outdoors, expressed in effective dose equivalence/year. The model is applied on a three rooms dwelling characterized by interconnecting air flows and on a dwelling with crawlspace. In this model the distinct parameters are variable in order to allow the investigation of the relative influence. The calculated effective dose equivalent for an adult in the dwelling was calculated to be about 1.7 mSv/year, composed of 15% from cosmic radiation, 35% from terrestrial radioactivity, 20% from radioactivity in the body and 30% from natural radionuclides in building materials. The calculations show an enhancement of about a factor of two in radon concentration in air in a room which is ventilated by air from an adjacent room. It is also shown that the attachment rate of radon products to aerosols and the plate-out effect are relatively important parameters influencing the magnitude of the dose rate. (Auth.)
Calculation method of passive tracer using regional ocean modeling system (ROMS)
International Nuclear Information System (INIS)
Tubono, Takaki; Tsumune, Daisuke; Misumi, Kazuhiro; Yoshida, Yoshikatsu
2010-01-01
A dose assessments method for packages shipping radioactive materials was developed to calculate concentrations of radioactive materials discharged from the hypothetically sinking point using Regional Ocean Modeling System (ROMS). The programs of ROMS were improved for simultaneously calculating the flow fields around Japan and the concentrations discharged from several bottom points in the continental shelf. The model domain covered the northeast pacific region around Japan, 20degN-65degN, 120degE-165degE, with 1/10 degree horizontal resolution and 30 sigma-levels. The ROMS model captured main features such as Kuroshio currents, including the separation location and the Kuroshio extension, and Oyashio currents. The calculated volume transports through the main straits such as Tokara strait, Tsushima strait and Tsugaru strait were compared well to the measured or estimated that. The calculated concentrations discharged from 12 bottom points showed mixing associated with the eddies of ocean currents. This method is available to evaluate effectively the concentrations of radioactive materials only by setting the subsidence location and the concentrations and volume discharged. (author)
A new model for the accurate calculation of natural gas viscosity
Directory of Open Access Journals (Sweden)
Xiaohong Yang
2017-03-01
Full Text Available Viscosity of natural gas is a basic and important parameter, of theoretical and practical significance in the domain of natural gas recovery, transmission and processing. In order to obtain the accurate viscosity data efficiently at a low cost, a new model and its corresponding functional relation are derived on the basis of the relationship among viscosity, temperature and density derived from the kinetic theory of gases. After the model parameters were optimized using a lot of experimental data, the diagram showing the variation of viscosity along with temperature and density is prepared, showing that: ① the gas viscosity increases with the increase of density as well as the increase of temperature in the low density region; ② the gas viscosity increases with the decrease of temperature in high density region. With this new model, the viscosity of 9 natural gas samples was calculated precisely. The average relative deviation between these calculated values and 1539 experimental data measured at 250–450 K and 0.10–140.0 MPa is less than 1.9%. Compared with the 793 experimental data with a measurement error less than 0.5%, the maximum relative deviation is less than 0.98%. It is concluded that this new model is more advantageous than the previous 8 models in terms of simplicity, accuracy, fast calculation, and direct applicability to the CO2 bearing gas samples.
Experience at Los Alamos with use of the optical model for applied nuclear data calculations
International Nuclear Information System (INIS)
Young, P.G.
1994-01-01
While many nuclear models are important in calculations of nuclear data, the optical model usually provides the basic underpinning of analyses directed at data for applications. An overview is given here of experience in the Nuclear Theory and Applications Group at Los Alamos National Laboratory in the use of the optical model for calculations of nuclear cross section data for applied purposes. We consider the direct utilization of total, elastic, and reaction cross sections for neutrons, protons, deuterons, tritons, 3 He and alpha particles in files of evaluated nuclear data covering the energy range of 0 to 200 MeV, as well as transmission coefficients for reaction theory calculations and neutron and proton wave functions direct-reaction and Feshbach-Kerman-Koonin analyses. Optical model codes such as SCAT and ECIS and the reaction theory codes COMNUC, GNASH FKK-GNASH, and DWUCK have primarily been used in our analyses. A summary of optical model parameterizations from past analyses at Los Alamos will be given, including detailed tabulations of the parameters for a selection of nuclei
Experience at Los Alamos with use of the optical model for applied nuclear data calculations
International Nuclear Information System (INIS)
Young, P.G.
1998-01-01
While many nuclear models are important in calculations of nuclear data, the optical model usually provides the basic underpinning of analyses directed at data for applications. An overview is given here of experience in the Nuclear Theory and Applications Group at Los Alamos National Laboratory in the use of the optical model for calculations of nuclear cross section data for applied purposes. We consider the direct utilization of total, elastic, and reaction cross sections for neutrons, protons, deuterons, tritons, 3 He and alpha particles in files of evaluated nuclear data covering the energy range of 0 to 200 MeV, as well as transmission coefficients for reaction theory calculations and neutron and proton wave functions in direct-reaction and Feshbach-Kerman-Koonin analyses. Optical model codes such as SCAT and ECIS and the reaction theory codes COMNUC, GNASH, FKK-GNASH, and DWUCK have primarily been used in our analyses. A summary of optical model parameterizations from past analyses at Los Alamos will be given, including detailed tabulations of the parameters for a selection of nuclei. (author)
Analytical model for release calculations in solid thin-foils ISOL targets
Energy Technology Data Exchange (ETDEWEB)
Egoriti, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Politecnico di Milano, Department of Energy, CeSNEF-Nuclear Engineering Division, Via Ponzio, 34/3, 20133 Milano (Italy); Boeckx, S. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); ICTEAM Inst., Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium); Ghys, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Houngbo, D., E-mail: donald.houngbo@sckcen.be [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium); Department of Flow, Heat and Combustion Mechanics, Gent University (UGent), St.-Pietersnieuwstraat 41, B-9000 Gent (Belgium); Popescu, L. [Belgian Nuclear Research Centre (SCK-CEN), Boeretang 200, B-2400 Mol (Belgium)
2016-10-01
A detailed analytical model has been developed to simulate isotope-release curves from thin-foils ISOL targets. It involves the separate modeling of diffusion and effusion inside the target. The former has been modeled using both first and second Fick's law. The latter, effusion from the surface of the target material to the end of the ionizer, was simulated with the Monte Carlo code MolFlow+. The calculated delay-time distribution for this process was then fitted using a double-exponential function. The release curve obtained from the convolution of diffusion and effusion shows good agreement with experimental data from two different target geometries used at ISOLDE. Moreover, the experimental yields are well reproduced when combining the release fraction with calculated in-target production.
OPT13B and OPTIM4 - computer codes for optical model calculations
International Nuclear Information System (INIS)
Pal, S.; Srivastava, D.K.; Mukhopadhyay, S.; Ganguly, N.K.
1975-01-01
OPT13B is a computer code in FORTRAN for optical model calculations with automatic search. A summary of different formulae used for computation is given. Numerical methods are discussed. The 'search' technique followed to obtain the set of optical model parameters which produce best fit to experimental data in a least-square sense is also discussed. Different subroutines of the program are briefly described. Input-output specifications are given in detail. A modified version of OPT13B specifications are given in detail. A modified version of OPT13B is OPTIM4. It can be used for optical model calculations where the form factors of different parts of the optical potential are known point by point. A brief description of the modifications is given. (author)