Hot channel calculation methodologies in case of Gd burnable poison
International Nuclear Information System (INIS)
Panka, I.; Kereszturi, A.
2008-01-01
The final step in the safety analysis is the investigation of the fulfilment of the acceptance criteria using hot channel calculations. Recently, there has been under way at Paks NPP to introduce a new, higher enriched (4.2 %) fuel type containing Gd burnable poison. To do that, for some transients the DBA analyses must be repeated and last year, as one of the first steps in this process, it was needed to review the hot channel calculation methodologies used in the analyses. The goal of the paper is to summarize some aspects of the hot channel calculation methodologies using different lattice pitches and different fuel types (Gd or non Gd and different enrichments). Mainly, three topics are discussed. First, the influence of the radial power distribution (and other burnup dependent parameters) inside the fuel pin are investigated, and then we discuss the problem of the selection of the appropriate 'frame parameter' in connection with the initial power level at the initial stationary state of DBA transients. Finally, we are trying to answer the question: is it possible to build up a conservative single closed sub-channel approach against multi channel approach?(Authors)
Methodology for calculating shear stress in a meandering channel
Kyung-Seop Sin; Christopher I. Thornton; Amanda L. Cox; Steven R. Abt
2012-01-01
Natural channels never stop changing their geomorphic characteristics. Natural alluvial streams are similar to living creatures because they generate water flow, develop point bars, alter bed profile, scour the bed, erode the bank, and cause other phenomena in the stream system. The geomorphic changes in a natural system lead to a wide array of research worldwide,...
Relative Hazard Calculation Methodology
International Nuclear Information System (INIS)
DL Strenge; MK White; RD Stenner; WB Andrews
1999-01-01
The methodology presented in this document was developed to provide a means of calculating the RH ratios to use in developing useful graphic illustrations. The RH equation, as presented in this methodology, is primarily a collection of key factors relevant to understanding the hazards and risks associated with projected risk management activities. The RH equation has the potential for much broader application than generating risk profiles. For example, it can be used to compare one risk management activity with another, instead of just comparing it to a fixed baseline as was done for the risk profiles. If the appropriate source term data are available, it could be used in its non-ratio form to estimate absolute values of the associated hazards. These estimated values of hazard could then be examined to help understand which risk management activities are addressing the higher hazard conditions at a site. Graphics could be generated from these absolute hazard values to compare high-hazard conditions. If the RH equation is used in this manner, care must be taken to specifically define and qualify the estimated absolute hazard values (e.g., identify which factors were considered and which ones tended to drive the hazard estimation)
Methodologies of Uncertainty Propagation Calculation
International Nuclear Information System (INIS)
Chojnacki, Eric
2002-01-01
After recalling the theoretical principle and the practical difficulties of the methodologies of uncertainty propagation calculation, the author discussed how to propagate input uncertainties. He said there were two kinds of input uncertainty: - variability: uncertainty due to heterogeneity, - lack of knowledge: uncertainty due to ignorance. It was therefore necessary to use two different propagation methods. He demonstrated this in a simple example which he generalised, treating the variability uncertainty by the probability theory and the lack of knowledge uncertainty by the fuzzy theory. He cautioned, however, against the systematic use of probability theory which may lead to unjustifiable and illegitimate precise answers. Mr Chojnacki's conclusions were that the importance of distinguishing variability and lack of knowledge increased as the problem was getting more and more complex in terms of number of parameters or time steps, and that it was necessary to develop uncertainty propagation methodologies combining probability theory and fuzzy theory
Transportation channels calculation method in MATLAB
International Nuclear Information System (INIS)
Averyanov, G.P.; Budkin, V.A.; Dmitrieva, V.V.; Osadchuk, I.O.; Bashmakov, Yu.A.
2014-01-01
Output devices and charged particles transport channels are necessary components of any modern particle accelerator. They differ both in sizes and in terms of focusing elements depending on particle accelerator type and its destination. A package of transport line designing codes for magnet optical channels in MATLAB environment is presented in this report. Charged particles dynamics in a focusing channel can be studied easily by means of the matrix technique. MATLAB usage is convenient because its information objects are matrixes. MATLAB allows the use the modular principle to build the software package. Program blocks are small in size and easy to use. They can be executed separately or commonly. A set of codes has a user-friendly interface. Transport channel construction consists of focusing lenses (doublets and triplets). The main of the magneto-optical channel parameters are total length and lens position and parameters of the output beam in the phase space (channel acceptance, beam emittance - beam transverse dimensions, particles divergence and image stigmaticity). Choice of the channel operation parameters is based on the conditions for satisfying mutually competing demands. And therefore the channel parameters calculation is carried out by using the search engine optimization techniques.
76 FR 71431 - Civil Penalty Calculation Methodology
2011-11-17
... DEPARTMENT OF TRANSPORTATION Federal Motor Carrier Safety Administration Civil Penalty Calculation... is currently evaluating its civil penalty methodology. Part of this evaluation includes a forthcoming... civil penalties. UFA takes into account the statutory penalty factors under 49 U.S.C. 521(b)(2)(D). The...
Methodology of shielding calculation for nuclear reactors
International Nuclear Information System (INIS)
Maiorino, J.R.; Mendonca, A.G.; Otto, A.C.; Yamaguchi, Mitsuo
1982-01-01
A methodology of calculation that coupling a serie of computer codes in a net that make the possibility to calculate the radiation, neutron and gamma transport, is described, for deep penetration problems, typical of nuclear reactor shielding. This net of calculation begining with the generation of constant multigroups, for neutrons and gamma, by the AMPX system, coupled to ENDF/B-IV data library, the transport calculation of these radiations by ANISN, DOT 3.5 and Morse computer codes, up to the calculation of absorbed doses and/or equivalents buy SPACETRAN code. As examples of the calculation method, results from benchmark n 0 6 of Shielding Benchmark Problems - ORNL - RSIC - 25, namely Neutron and Secondary Gamma Ray fluence transmitted through a Slab of Borated Polyethylene, are presented. (Author) [pt
Statistical calculation of hot channel factors
International Nuclear Information System (INIS)
Farhadi, K.
2007-01-01
It is a conventional practice in the design of nuclear reactors to introduce hot channel factors to allow for spatial variations of power generation and flow distribution. Consequently, it is not enough to be able to calculate the nominal temperature distributions of fuel element, cladding, coolant, and central fuel. Indeed, one must be able to calculate the probability that the imposed temperature or heat flux limits in the entire core is not exceeded. In this paper, statistical methods are used to calculate hot channel factors for a particular case of a heterogeneous, Material Testing Reactor (MTR) and compare the results obtained from different statistical methods. It is shown that among the statistical methods available, the semi-statistical method is the most reliable one
Selection of skin dose calculation methodologies
International Nuclear Information System (INIS)
Farrell, W.E.
1987-01-01
This paper reports that good health physics practice dictates that a dose assessment be performed for any significant skin contamination incident. There are, however, several methodologies that could be used, and while there is probably o single methodology that is proper for all cases of skin contamination, some are clearly more appropriate than others. This can be demonstrated by examining two of the more distinctly different options available for estimating skin dose the calculational methods. The methods compiled by Healy require separate beta and gamma calculations. The beta calculational method is the derived by Loevinger, while the gamma dose is calculated from the equation for dose rate from an infinite plane source with an absorber between the source and the detector. Healy has provided these formulas in graphical form to facilitate rapid dose rate determinations at density thicknesses of 7 and 20 mg/cm 2 . These density thicknesses equate to the regulatory definition of the sensitive layer of the skin and a more arbitrary value to account of beta absorption in contaminated clothing
Monte Carlo calculations of channeling radiation
International Nuclear Information System (INIS)
Bloom, S.D.; Berman, B.L.; Hamilton, D.C.; Alguard, M.J.; Barrett, J.H.; Datz, S.; Pantell, R.H.; Swent, R.H.
1981-01-01
Results of classical Monte Carlo calculations are presented for the radiation produced by ultra-relativistic positrons incident in a direction parallel to the (110) plane of Si in the energy range 30 to 100 MeV. The results all show the characteristic CR(channeling radiation) peak in the energy range 20 keV to 100 keV. Plots of the centroid energies, widths, and total yields of the CR peaks as a function of energy show the power law dependences of γ 1 5 , γ 1 7 , and γ 2 5 respectively. Except for the centroid energies and power-law dependence is only approximate. Agreement with experimental data is good for the centroid energies and only rough for the widths. Adequate experimental data for verifying the yield dependence on γ does not yet exist
A Methodology for Calculating Radiation Signatures
Energy Technology Data Exchange (ETDEWEB)
Klasky, Marc Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wilcox, Trevor [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bathke, Charles G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); James, Michael R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-05-01
A rigorous formalism is presented for calculating radiation signatures from both Special Nuclear Material (SNM) as well as radiological sources. The use of MCNP6 in conjunction with CINDER/ORIGEN is described to allow for the determination of both neutron and photon leakages from objects of interest. In addition, a description of the use of MCNP6 to properly model the background neutron and photon sources is also presented. Examinations of the physics issues encountered in the modeling are investigated so as to allow for guidance in the user discerning the relevant physics to incorporate into general radiation signature calculations. Furthermore, examples are provided to assist in delineating the pertinent physics that must be accounted for. Finally, examples of detector modeling utilizing MCNP are provided along with a discussion on the generation of Receiver Operating Curves, which are the suggested means by which to determine detectability radiation signatures emanating from objects.
Relative Hazard and Risk Measure Calculation Methodology
International Nuclear Information System (INIS)
Stenner, Robert D.; Strenge, Dennis L.; Elder, Matthew S.; Andrews, William B.; Walton, Terry L.
2003-01-01
The RHRM equations, as represented in methodology and code presented in this report, are primarily a collection of key factors normally used in risk assessment that are relevant to understanding the hazards and risks associated with projected mitigation, cleanup, and risk management activities. The RHRM code has broad application potential. For example, it can be used to compare one mitigation, cleanup, or risk management activity with another, instead of just comparing it to just the fixed baseline. If the appropriate source term data are available, it can be used in its non-ratio form to estimate absolute values of the associated controlling hazards and risks. These estimated values of controlling hazards and risks can then be examined to help understand which mitigation, cleanup, or risk management activities are addressing the higher hazard conditions and risk reduction potential at a site. Graphics can be generated from these absolute controlling hazard and risk values to graphically compare these high hazard and risk reduction potential conditions. If the RHRM code is used in this manner, care must be taken to specifically define and qualify (e.g., identify which factors were considered and which ones tended to drive the hazard and risk estimates) the resultant absolute controlling hazard and risk values
Audit calculation for the LOCA methodology for KSNP
Energy Technology Data Exchange (ETDEWEB)
Lee, Un Chul; Park, Chang Hwan; Choi, Yong Won; Yoo, Jun Soo [Seoul National Univ., Seoul (Korea, Republic of)
2006-11-15
The objective of this research is to perform the audit regulatory calculation for the LOCA methodology for KSNP. For LBLOCA calculation, several uncertainty variables and new ranges of those are added to those of previous KINS-REM to improve the applicability of KINS-REM for KSNP LOCA. And those results are applied to LBLOCA audit calculation by statistical method. For SBLOCA calculation, after selecting BATHSY9.1.b, which is not used by KHNP, the results of RELAP5/Mod3.3 and RELAP5/MOD3.3ef-sEM for KSNP SBLOCA are compared to evaluate the conservativeness or applicability of RELAP5/MOD3.3ef-sEM code for KSNP SBLOCA. The result of this research can be used to support the activities of KINS for reviewing the LOCA methodology for KSNP proposed by KHNP.
Development of Audit Calculation Methodology for RIA Safety Analysis
Energy Technology Data Exchange (ETDEWEB)
Lee, Joosuk; Kim, Gwanyoung; Woo, Swengwoong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)
2015-05-15
The interim criteria contain more stringent limits than previous ones. For example, pellet-to-cladding mechanical interaction(PCMI) was introduced as a new failure criteria. And both short-term (e.g. fuel-to coolant interaction, rod burst) and long-term(e.g., fuel rod ballooning, flow blockage) phenomena should be addressed for core coolability assurance. For dose calculations, transient-induced fission gas release has to be accounted additionally. Traditionally, the approved RIA analysis methodologies for licensing application are developed based on conservative approach. But newly introduced safety criteria tend to reduce the margins to the criteria. Thereby, licensees are trying to improve the margins by utilizing a less conservative approach. In this situation, to cope with this trend, a new audit calculation methodology needs to be developed. In this paper, the new methodology, which is currently under developing in KINS, was introduced. For the development of audit calculation methodology of RIA safety analysis based on the realistic evaluation approach, preliminary calculation by utilizing the best estimate code has been done on the initial core of APR1400. Followings are main conclusions. - With the assumption of single full-strength control rod ejection in HZP condition, rod failure due to PCMI is not predicted. - And coolability can be assured in view of entalphy and fuel melting. - But, rod failure due to DNBR is expected, and there is possibility of fuel failure at the rated power conditions also.
A gamma heating calculation methodology for research reactor application
International Nuclear Information System (INIS)
Lee, Y.K.; David, J.C.; Carcreff, H.
2001-01-01
Gamma heating is an important issue in research reactor operation and fuel safety. Heat deposition in irradiation targets and temperature distribution in irradiation facility should be determined so as to obtain the optimal irradiation conditions. This paper presents a recently developed gamma heating calculation methodology and its application on the research reactors. Based on the TRIPOLI-4 Monte Carlo code under the continuous-energy option, this new calculation methodology was validated against calorimetric measurements realized within a large ex-core irradiation facility of the 70 MWth OSIRIS materials testing reactor (MTR). The contributions from prompt fission neutrons, prompt fission γ-rays, capture γ-rays and inelastic γ-rays to heat deposition were evaluated by a coupled (n, γ) transport calculation. The fission product decay γ-rays were also considered but the activation γ-rays were neglected in this study. (author)
ANL calculational methodologies for determining spent nuclear fuel source term
International Nuclear Information System (INIS)
McKnight, R. D.
2000-01-01
Over the last decade Argonne National Laboratory has developed reactor depletion methods and models to determine radionuclide inventories of irradiated EBR-II fuels. Predicted masses based on these calculational methodologies have been validated using available data from destructive measurements--first from measurements of lead EBR-II experimental test assemblies and later using data obtained from processing irradiated EBR-II fuel assemblies in the Fuel Conditioning Facility. Details of these generic methodologies are described herein. Validation results demonstrate these methods meet the FCF operations and material control and accountancy requirements
RAMA Methodology for the Calculation of Neutron Fluence
International Nuclear Information System (INIS)
Villescas, G.; Corchon, F.
2013-01-01
he neutron fluence plays an important role in the study of the structural integrity of the reactor vessel after a certain time of neutron irradiation. The NRC defined in the Regulatory Guide 1.190, the way must be estimated neutron fluence, including uncertainty analysis of the validation process (creep uncertainty is ? 20%). TRANSWARE Enterprises Inc. developed a methodology for calculating the neutron flux, 1,190 based guide, known as RAMA. Uncertainty values obtained with this methodology, for about 18 vessels, are less than 10%.
Void fraction calculation in a channel containing boiling coolant
International Nuclear Information System (INIS)
Norelli, F.
1978-01-01
The problem of void fraction calculation was studied for a channel containing boiling coolant, when a slip ratio correlation is used. Use of fitting (e.g. polinomial or rational algebraic) for slip ratio correlation and the characteristic method are proposed in this work. In this way we are reduced to some elementary quadrature problem. Another problem discussed in the present work concerns what we must consider as ''initial condition'' in any initial value problem, in order to take into account different error distributions in steady state and in successive time-dependent calculations
Methodology for calculating power consumption of planetary mixers
Antsiferov, S. I.; Voronov, V. P.; Evtushenko, E. I.; Yakovlev, E. A.
2018-03-01
The paper presents the methodology and equations for calculating the power consumption necessary to overcome the resistance of a dry mixture caused by the movement of cylindrical rods in the body of a planetary mixer, as well as the calculation of the power consumed by idling mixers of this type. The equations take into account the size and physico-mechanical properties of mixing material, the size and shape of the mixer's working elements and the kinematics of its movement. The dependence of the power consumption on the angle of rotation in the plane perpendicular to the axis of rotation of the working member is presented.
Validating analysis methodologies used in burnup credit criticality calculations
International Nuclear Information System (INIS)
Brady, M.C.; Napolitano, D.G.
1992-01-01
The concept of allowing reactivity credit for the depleted (or burned) state of pressurized water reactor fuel in the licensing of spent fuel facilities introduces a new challenge to members of the nuclear criticality community. The primary difference in this analysis approach is the technical ability to calculate spent fuel compositions (or inventories) and to predict their effect on the system multiplication factor. Isotopic prediction codes are used routinely for in-core physics calculations and the prediction of radiation source terms for both thermal and shielding analyses, but represent an innovation for criticality specialists. This paper discusses two methodologies currently being developed to specifically evaluate isotopic composition and reactivity for the burnup credit concept. A comprehensive approach to benchmarking and validating the methods is also presented. This approach involves the analysis of commercial reactor critical data, fuel storage critical experiments, chemical assay isotopic data, and numerical benchmark calculations
Numerical calculation of radiation pattern of plasma channel antenna
International Nuclear Information System (INIS)
Xia Xinren; Yin Chengyou
2010-01-01
The idea of plasma channel antenna (PCA) for high power microwave weapon is presented in this paper. The radiation pattern of PCA is calculated. The directivity functions of general antenna are derived. The near electromagnetic model of PCA is created based on physical circumstances. The electromagnetic fields of PCA and surrounding air in cylindrical coordinate are given. The dispersion equation of PCA is deduced by applying the boundary conditions of electromagnetic fields. The surface wave vector of PCA is achieved. The variations of radiation characteristic with plasma density, antenna length and antenna radius are emphatically discussed. The controllability of PCA's radiation patterns is confirmed. (authors)
Methodology of dose calculation for the SRS SAR
International Nuclear Information System (INIS)
Price, J.B.
1991-07-01
The Savannah River Site (SRS) Safety Analysis Report (SAR) covering K reactor operation assesses a spectrum of design basis accidents. The assessment includes estimation of the dose consequences from the analyzed accidents. This report discusses the methodology used to perform the dose analysis reported in the SAR and also includes the quantified doses. Doses resulting from postulated design basis reactor accidents in Chapter 15 of the SAR are discussed, as well as an accident in which three percent of the fuel melts. Doses are reported for both atmospheric and aqueous releases. The methodology used to calculate doses from these accidents as reported in the SAR is consistent with NRC guidelines and industry standards. The doses from the design basis accidents for the SRS reactors are below the limits set for commercial reactors by the NRC and also meet industry criteria. A summary of doses for various postulated accidents is provided
REVIEW OF METHODOLOGIES FOR COSTS CALCULATING OF RUMINANTS IN SLOVAKIA
Directory of Open Access Journals (Sweden)
Zuzana KRUPOVÁ
2012-09-01
Full Text Available The objective of this work was to synthesise and analyse the methodologies and the biological aspects of the costs calculation in ruminants in Slovakia. According to literature, the account classification of cost items is most often considered for construction of costing formula. The costs are mostly divided into fixed (costs independent from volume of herd’s production and variable ones (costs connected with improvement of breeding conditions. Cost for feeds and beddings, labour costs, other direct costs and depreciations were found as the most important cost items in ruminants. It can be assumed that including the depreciations into costs of the basic herd takes into consideration the real costs simultaneously invested into raising of young animals in the given period. Costs are calculated for the unit of the main and by-products and their classification is influenced mainly by the type of livestock and production system. In dairy cows is usually milk defined as the main product, and by- products are live born calf and manure. The base calculation unit is kilogram of milk (basic herd of cows and kilogram of gain and kilogram of live weight (young breeding cattle. In suckler cows is a live-born calf the main product and manure is the by-product. The costs are mostly calculated per suckler cow, live-born calf and per kilogram of live weight of weaned calf. Similar division of products into main and by-products is also in cost calculation for sheep categories. The difference is that clotted cheese is also considered as the main product of basic herd in dairy sheep and greasy wool as the by-products in all categories. Definition of the base calculation units in sheep categories followed the mentioned classification. The value of a by-product in cattle and sheep is usually set according to its quantity and intra- plant price of the by-product. In the calculation of the costs for sheep and cattle the “structural ewe” and “structural cow
Development of new methodology for dose calculation in photographic dosimetry
International Nuclear Information System (INIS)
Daltro, T.F.L.
1994-01-01
A new methodology for equivalent dose calculations has been developed at IPEN-CNEN/SP to be applied at the Photographic Dosimetry Laboratory using artificial intelligence techniques by means of neutral network. The research was orientated towards the optimization of the whole set of parameters involves in the film processing going from the irradiation in order to obtain the calibration curve up to the optical density readings. The learning of the neutral network was performed by taking the readings of optical density from calibration curve as input and the effective energy and equivalent dose as output. The obtained results in the intercomparison show an excellent agreement with the actual values of dose and energy given by the National Metrology Laboratory of Ionizing Radiation. (author)
Development of new methodology for dose calculation in photographic dosimetry
International Nuclear Information System (INIS)
Daltro, T.F.L.; Campos, L.L.
1994-01-01
A new methodology for equivalent dose calculation has been developed at IPEN-CNEN/SP to be applied at the Photographic Dosimetry Laboratory using artificial intelligence techniques by means of neural network. The research was oriented towards the optimization of the whole set of parameters involved in the film processing going from the irradiation in order to obtain the calibration curve up to the optical density readings. The learning of the neural network was performed by taking readings of optical density from calibration curve as input and the effective energy and equivalent dose as output. The obtained results in the intercomparison show an excellent agreement with the actual values of dose and energy given by the National Metrology Laboratory of Ionizing Radiation
Methodology of calculation in one-dimensional kinetic
International Nuclear Information System (INIS)
Paixao, S.B.; Marzo, M.A.S.; Alvim, A.C.M.
1986-01-01
This paper resulted from a study of the WIGLE's program calculation method ]1], which is RESTRICTED to USA users. In view of this fact, a successful attempt was made to fully understand and reproduce the WIGLE methodology, thus providing support for national development on the subject. After finishing the theoretical study, CITER-1D, a program for search of control rod position in PWR slabs under steady-state conditions was written and is supposed to correctly reproduce WIGL3 ]4] version behavior. Program restriction to steady-state conditions was due to scarcity of examples, thought to be intentional, as well as to time limitations for conclusion of a M.Sc. Thesis ]2], which originated this work. Results obtained with CITER-1D agree very well with the ones found in the the available literature pertaining to WIGL3. Further work on CITER-1D is being pursued, in order to complete the program. (Author) [pt
A Methodology Proposal to Calculate the Externalities of Liquid Biofuels
Energy Technology Data Exchange (ETDEWEB)
Galan, A.; Gonzalez, R.; Varela, M. [Ciemat. Madrid (Spain)
1999-05-01
The aim of the survey is to propose a methodology to calculate the externalities associated with the liquid bio fuels cycle. The report defines the externalities from a theoretical point of view and classifies them. The reasons to value the externalities are explained as well as the existing methods. Furthermore, an evaluation of specific environmental and non-environmental externalities is also presented. The report reviews the current situation of the transport sector, considering its environmental effects and impacts. The progress made by the ExternE and ExternE-transport projects related the externalities of transport sector is assessed. Finally, the report analyses the existence of different economic instruments to internalize the external effects of the transport sector as well as other aspects of this internalization. (Author) 58 refs.
Parameters calculation of a shielding experiment and evaluation of calculation methodology
International Nuclear Information System (INIS)
Gavazza, S.; Otto, A.C.; Gomes, I.C.; Maiorino, J.R.
1986-01-01
In this text is carried out the evaluation of radiation transport methodology, comparying the calculated reactions and dose rates, for neutrons and gamma-rays, with the experimental measurements obtained on iron shield, irradiated in YAYOI reactor. Were employed the ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system for generation of cross sections, collapsed by the ANISN code. The transport calculation were made by using the DOT 3.5 code, adjusting the spectrum of the iron shield boundary source to the reactions and dose rates, measured at the beginning of shield. The distributions calculated for neutrons and gamma-rays, on iron shield, presented coherence with the experimental measurements. (Author) [pt
Methodology for calculating guideline concentrations for safety shot sites
International Nuclear Information System (INIS)
1997-06-01
Residual plutonium (Pu), with trace quantities of depleted uranium (DU) or weapons grade uranium (WU), exists in surficial soils at the Nevada Test Site (NTS), Nellis Air Force Range (NAFR), and the Tonopah Test Range (TTR) as the result of the above-ground testing of nuclear weapons and special experiments involving the detonation of plutonium-bearing devices. The special experiments (referred to as safety shots) involving plutonium-bearing devices were conducted to study the behavior of Pu as it was being explosively compressed; ensure that the accidental detonation of the chemical explosive in a production weapon would not result in criticality; evaluate the ability of personnel to manage large-scale Pu dispersal accidents; and develop criteria for transportation and storage of nuclear weapons. These sites do not pose a health threat to either workers or the general public because they are under active institutional control. The DOE is committed to remediating the safety shot sites so that radiation exposure to the public, both now and in the future, will be maintained within the established limits and be as low as reasonably achievable. Remediation requires calculation of a guideline concentration for the Pu, U, and their decay products that are present in the surface soil. This document presents the methodology for calculating guideline concentrations of weapons grade plutonium, weapons grade uranium, and depleted uranium in surface soils at the safety shot sites. Emphasis is placed on obtaining site-specific data for use in calculating dose to potential residents from the residual soil contamination
Development of a computational methodology for internal dose calculations
International Nuclear Information System (INIS)
Yoriyaz, Helio
2000-01-01
A new approach for calculating internal dose estimates was developed through the use of a more realistic computational model of the human body and a more precise tool for the radiation transport simulation. The present technique shows the capability to build a patient-specific phantom with tomography data (a voxel-based phantom) for the simulation of radiation transport and energy deposition using Monte Carlo methods such as in the MCNP-4B code. In order to utilize the segmented human anatomy as a computational model for the simulation of radiation transport, an interface program, SCMS, was developed to build the geometric configurations for the phantom through the use of tomographic images. This procedure allows to calculate not only average dose values but also spatial distribution of dose in regions of interest. With the present methodology absorbed fractions for photons and electrons in various organs of the Zubal segmented phantom were calculated and compared to those reported for the mathematical phantoms of Snyder and Cristy-Eckerman. Although the differences in the organ's geometry between the phantoms are quite evident, the results demonstrate small discrepancies, however, in some cases, considerable discrepancies were found due to two major causes: differences in the organ masses between the phantoms and the occurrence of organ overlap in the Zubal segmented phantom, which is not considered in the mathematical phantom. This effect was quite evident for organ cross-irradiation from electrons. With the determination of spatial dose distribution it was demonstrated the possibility of evaluation of more detailed doses data than those obtained in conventional methods, which will give important information for the clinical analysis in therapeutic procedures and in radiobiologic studies of the human body. (author)
Methodology for calculating guideline concentrations for safety shot sites
Energy Technology Data Exchange (ETDEWEB)
NONE
1997-06-01
Residual plutonium (Pu), with trace quantities of depleted uranium (DU) or weapons grade uranium (WU), exists in surficial soils at the Nevada Test Site (NTS), Nellis Air Force Range (NAFR), and the Tonopah Test Range (TTR) as the result of the above-ground testing of nuclear weapons and special experiments involving the detonation of plutonium-bearing devices. The special experiments (referred to as safety shots) involving plutonium-bearing devices were conducted to study the behavior of Pu as it was being explosively compressed; ensure that the accidental detonation of the chemical explosive in a production weapon would not result in criticality; evaluate the ability of personnel to manage large-scale Pu dispersal accidents; and develop criteria for transportation and storage of nuclear weapons. These sites do not pose a health threat to either workers or the general public because they are under active institutional control. The DOE is committed to remediating the safety shot sites so that radiation exposure to the public, both now and in the future, will be maintained within the established limits and be as low as reasonably achievable. Remediation requires calculation of a guideline concentration for the Pu, U, and their decay products that are present in the surface soil. This document presents the methodology for calculating guideline concentrations of weapons grade plutonium, weapons grade uranium, and depleted uranium in surface soils at the safety shot sites. Emphasis is placed on obtaining site-specific data for use in calculating dose to potential residents from the residual soil contamination.
Relative Hazard and Risk Measure Calculation Methodology Rev 1
International Nuclear Information System (INIS)
Stenner, Robert D.; White, Michael K.; Strenge, Dennis L.; Aaberg, Rosanne L.; Andrews, William B.
2000-01-01
Documentation of the methodology used to calculate relative hazard and risk measure results for the DOE complex wide risk profiles. This methodology is used on major site risk profiles. In February 1997, the Center for Risk Excellence (CRE) was created and charged as a technical, field-based partner to the Office of Science and Risk Policy (EM-52). One of the initial charges to the CRE is to assist the sites in the development of ''site risk profiles.'' These profiles are to be relatively short summaries (periodically updated) that present a broad perspective on the major risk related challenges that face the respective site. The risk profiles are intended to serve as a high-level communication tool for interested internal and external parties to enhance the understanding of these risk-related challenges. The risk profiles for each site have been designed to qualitatively present the following information: (1) a brief overview of the site, (2) a brief discussion on the historical mission of the site, (3) a quote from the site manager indicating the site's commitment to risk management, (4) a listing of the site's top risk-related challenges, (5) a brief discussion and detailed table presenting the site's current risk picture, (6) a brief discussion and detailed table presenting the site's future risk reduction picture, and (7) graphic illustrations of the projected management of the relative hazards at the site. The graphic illustrations were included to provide the reader of the risk profiles with a high-level mental picture to associate with all the qualitative information presented in the risk profile. Inclusion of these graphic illustrations presented the CRE with the challenge of how to fold this high-level qualitative risk information into a system to produce a numeric result that would depict the relative change in hazard, associated with each major risk management action, so it could be presented graphically. This report presents the methodology developed
A methodology for delineating planning-level channel migration zones.
2014-07-01
The Washington State administrative codes that implement the Shoreline Management Act (SMA) require communities to identify the general location of channel migration zones (CMZs), and regulate development within these areas on shoreline streams. Shor...
METHODOLOGY FOR HYDRAULIC CALCULATION OF RIVER REGULATION AND DETERMINATION OF DIKE PARAMETERS
Directory of Open Access Journals (Sweden)
E. I. Mikhnevich
2017-01-01
Full Text Available Territory protection against flood water inundation and creation of polder systems are carried out with the help of protection dikes. One of the main requirements to the composition of polder systems in flood plains is a location of border dikes beyond meander belt in order to avoid their erosion when meander development occurs. Meander belt width can be determined on the basis of the analysis of multi-year land surveying pertaining top river-bed building and in the case when such data is not available this parameter is calculated in accordance with the Snishchenko formula. While banking-up a river bed a flooded area is decreasing and, consequently, water level in inter-dike space and rate of flood water are significantly increasing. For this reason it is necessary to locate dikes at a such distance from a river bed which will not cause rather high increase in water level and flow velocity in the inter-dike space. Methodology for hydraulic calculation of river regulation has been developed in order to substantiate design parameters for levee systems, creation of favourable hydraulic regime in these systems and provision of sustainability for dikes. Its main elements are calculations of pass-through capacity of the leveed channel and rise of water level in inter-dike space, and distance between dikes and their crest level. Peculiar feature of the proposed calculated formulae is an interaction consideration of channel and inundated flows. Their mass-exchanging process results in slowing-down of the channel flow and acceleration of the inundated flow. This occurrence is taken into account and coefficients of kinematic efficiency are introduced to the elements of water flow rate in the river channel and flood plain, respectively. The adduced dependencies for determination of a dike crest level (consequently their height take into consideration a rise of water level in inter-dike space for two types of polder systems: non-inundable (winter dikes with
Burnup calculation methodology in the serpent 2 Monte Carlo code
International Nuclear Information System (INIS)
Leppaenen, J.; Isotalo, A.
2012-01-01
This paper presents two topics related to the burnup calculation capabilities in the Serpent 2 Monte Carlo code: advanced time-integration methods and improved memory management, accomplished by the use of different optimization modes. The development of the introduced methods is an important part of re-writing the Serpent source code, carried out for the purpose of extending the burnup calculation capabilities from 2D assembly-level calculations to large 3D reactor-scale problems. The progress is demonstrated by repeating a PWR test case, originally carried out in 2009 for the validation of the newly-implemented burnup calculation routines in Serpent 1. (authors)
Methodology for Calculating Latency of GPS Probe Data
Energy Technology Data Exchange (ETDEWEB)
Young, Stanley E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wang, Zhongxiang [University of Maryland; Hamedi, Masoud [University of Maryland
2017-10-01
Crowdsourced GPS probe data, such as travel time on changeable-message signs and incident detection, have been gaining popularity in recent years as a source for real-time traffic information to driver operations and transportation systems management and operations. Efforts have been made to evaluate the quality of such data from different perspectives. Although such crowdsourced data are already in widespread use in many states, particularly the high traffic areas on the Eastern seaboard, concerns about latency - the time between traffic being perturbed as a result of an incident and reflection of the disturbance in the outsourced data feed - have escalated in importance. Latency is critical for the accuracy of real-time operations, emergency response, and traveler information systems. This paper offers a methodology for measuring probe data latency regarding a selected reference source. Although Bluetooth reidentification data are used as the reference source, the methodology can be applied to any other ground truth data source of choice. The core of the methodology is an algorithm for maximum pattern matching that works with three fitness objectives. To test the methodology, sample field reference data were collected on multiple freeway segments for a 2-week period by using portable Bluetooth sensors as ground truth. Equivalent GPS probe data were obtained from a private vendor, and their latency was evaluated. Latency at different times of the day, impact of road segmentation scheme on latency, and sensitivity of the latency to both speed-slowdown and recovery-from-slowdown episodes are also discussed.
Evaluation and reffinement of the neutronic calculation methodology
International Nuclear Information System (INIS)
Conti Filho, P.
1984-01-01
A computational code that has the homogenized cross section given by the LEOPARD code as input was developed. The code gives polinomial coefficients that represent the homogenized cross section as a function of the local burnup and the boron concentration for the assembly, for each step in the reactor Burnup. Lately, were developed an interface between the LEOPARD code Polinomiun Generator program and CITATION code to became possible to CITATION code to set the homogenized microscopic cross section as function of the local caracteristics of the assembly on the way to make the calculation of the reactor Burnup. For a choosen reactor (1900MWth) have been done the inicial calculation (super-cells calculation and others Input) and after that were done the calculation with and without the polinomia. The analyses of the results of the CITATION code were done and the principal results were presented here. (Author) [pt
Scholten, O.; Usov, A.
To describe photo- and meson-induced reactions on the nucleon, one is faced with a rather extensive coupled-channel problem Ignoring the effects of channel coupling, as one would do in describing a certain reaction at the tree level; invariably creates a large inconsistency between the different
Recent progress and developments in LWR-PV calculational methodology
International Nuclear Information System (INIS)
Maerker, R.E.; Broadhead, B.L.; Williams, M.L.
1984-01-01
New and improved techniques for calculating beltline surveillance activities and pressure vessel fluences with reduced uncertainties have recently been developed. These techniques involve the combining of monitored in-core power data with diffusion theory calculated pin-by-pin data to yield absolute source distributions in R-THETA and R-Z geometries suitable for discrete ordinate transport calculations. Effects of finite core height, whenever necessary, can be considered by the use of a three-dimensional fluence rate synthesis procedure. The effects of a time-dependent spatial source distribution may be readily evaluated by applying the concept of the adjoint function, and simplifying the procedure to such a degree that only one forward and one adjoint calculation are required to yield all the dosimeter activities for all beltline surveillance locations at once. The addition of several more adjoint calculations using various fluence rates as responses is all that is needed to determine all the pressure vessel group fluences for all beltline locations for an arbitrary source distribution
Augmented wave ab initio EFG calculations: some methodological warnings
International Nuclear Information System (INIS)
Errico, Leonardo A.; Renteria, Mario; Petrilli, Helena M.
2007-01-01
We discuss some accuracy aspects inherent to ab initio electronic structure calculations in the understanding of nuclear quadrupole interactions. We use the projector augmented wave method to study the electric-field gradient (EFG) at both Sn and O sites in the prototype cases SnO and SnO 2 . The term ab initio is used in the standard context of the also called first principles methods in the framework of the Density Functional Theory. As the main contributions of EFG calculations to problems in condensed matter physics are related to structural characterizations on the atomic scale, we discuss the 'state of the art' on theoretical EFG calculations and make a brief critical review on the subject, calling attention to some fundamental theoretical aspects
Augmented wave ab initio EFG calculations: some methodological warnings
Energy Technology Data Exchange (ETDEWEB)
Errico, Leonardo A. [Departamento de Fisica-IFLP (CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67 (1900) La Plata (Argentina); Renteria, Mario [Departamento de Fisica-IFLP (CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC67 (1900) La Plata (Argentina); Petrilli, Helena M. [Instituto de Fisica-DFMT, Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil)]. E-mail: hmpetril@macbeth.if.usp.br
2007-02-01
We discuss some accuracy aspects inherent to ab initio electronic structure calculations in the understanding of nuclear quadrupole interactions. We use the projector augmented wave method to study the electric-field gradient (EFG) at both Sn and O sites in the prototype cases SnO and SnO{sub 2}. The term ab initio is used in the standard context of the also called first principles methods in the framework of the Density Functional Theory. As the main contributions of EFG calculations to problems in condensed matter physics are related to structural characterizations on the atomic scale, we discuss the 'state of the art' on theoretical EFG calculations and make a brief critical review on the subject, calling attention to some fundamental theoretical aspects.
Alternative methodology for irradiation reactor experimental shielding calculation
International Nuclear Information System (INIS)
Vellozo, Sergio de Oliveira; Vital, Helio de Carvalho
1996-01-01
Due to a change in the project of the Experimental Irradiation Reactor, its shielding design had to be recalculated according to an alternative simplified analytical approach, since the standard transport calculations were temporarily unavailable. In the calculation of the new width for the shielding made up of steel and high-density concrete layers, the following radiation components were considered: fast neutrons and primary gammas (produced by fission and beta decay), from the core; and secondary gammas, produced by thermal neutron capture in the shielding. (author)
Channel Capacity Calculation at Large SNR and Small Dispersion within Path-Integral Approach
Reznichenko, A. V.; Terekhov, I. S.
2018-04-01
We consider the optical fiber channel modelled by the nonlinear Shrödinger equation with additive white Gaussian noise. Using Feynman path-integral approach for the model with small dispersion we find the first nonzero corrections to the conditional probability density function and the channel capacity estimations at large signal-to-noise ratio. We demonstrate that the correction to the channel capacity in small dimensionless dispersion parameter is quadratic and positive therefore increasing the earlier calculated capacity for a nondispersive nonlinear optical fiber channel in the intermediate power region. Also for small dispersion case we find the analytical expressions for simple correlators of the output signals in our noisy channel.
Methodology to calculate wall thickness in metallic pipes
International Nuclear Information System (INIS)
Ramirez, G.F.; Feliciano, H.J.
1992-01-01
The principal objective in the developing of the activities of industrial type is to carry out a efficient and productive task: that implies necessarily to know the best working conditions of the equipment and installations to be concerned. The applications of the radioisotope techniques have a long time as useful tools in several fields of human work. For example, in the Petroleos Mexicanos petrochemical complexes, by safety reasons and for to avoid until maximum the losses, it must be know with a high possible precision the operation regimes of the lines of tubes that they conduce the hydrocarbons, with the purpose to know when they should be replaced the defective or wasted pieces. In the Mexican Petroleum Institute is carrying out a work that it has by objective to develop a methodology bases in the use of radioisotopes that permits to determine the average thickness of the metallic tubes wall, that they have thermic insulator, with a precision of ±0.127 mm (±5 thousandth inch). The method is based in the radiation use emitted by Cs-137 sources. In this work it is described the methodology development so as the principal results obtained. (Author)
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
IRT-type research reactor physical calculation methodology
International Nuclear Information System (INIS)
Carrera, W.; Castaneda, S.; Garcia, F.; Garcia, L.; Reyes, O.
1990-01-01
In the present paper an established physical calculation procedure for the research reactor of the Nuclear Research Center (CIN) is described. The results obtained by the method are compared with the ones reported during the physical start up of a reactor with similar characteristics to the CIN reactor. 11 refs
Methodological problems in pressure profile calculations for lipid bilayers
DEFF Research Database (Denmark)
Sonne, Jacob; Hansen, Flemming Yssing; Peters, Günther H.J.
2005-01-01
calculations: The first problem is that the pressure profile is not uniquely defined since the expression for the local pressure involves an arbitrary choice of an integration contour. We have investigated two different choices leading to the Irving-Kirkwood (IK) and Harasima (H) expressions for the local...
Application of a Methodology to calculate logistical cost
Directory of Open Access Journals (Sweden)
Joaquín Mock-Díaz
2017-12-01
Full Text Available At present time, the managerial environment constantly becomes more aggressive and unstable. For that reason, companies are forced to improve on a regular basis their management, to increase their economic efficiency and their effectiveness and have a better performance. Within this context, the objective of this research is to apply a methodology to determine logistical costs, in a service−providing company, which allows assessing the behavior of such costs during the year 2016. A financial assessment performed to the logistical activities proved the existence of a high cost of opportunity, element mainly dependent on inventory rotation. For the purposes of this study, several scientific methods were used; the historical−logical method, to analyze the historical evolution of logistics; and the analysis−synthesis method to gather the elements and main ideas that characterize it.
Development of new methodology for dose calculation in photographic dosimetry
International Nuclear Information System (INIS)
Daltro, T.F.L.; Campos, L.L.; Perez, H.E.B.
1996-01-01
The personal dosemeter system of IPEN is based on film dosimetry. Personal doses at IPEN are mainly due to X or gamma radiation. The use of personal photographic dosemeters involves two steps: firstly, data acquisition including their evaluation with respect to the calibration quantity and secondly, the interpretation of the data in terms of effective dose. The effective dose was calculated using artificial intelligence techniques by means of neural network. The learning of the neural network was performed by taking the readings of optical density as a function of incident energy and exposure from the calibration curve. The obtained output in the daily grind is the mean effective energy and the effective dose. (author)
Analysis of offsite dose calculation methodology for a nuclear power reactor
International Nuclear Information System (INIS)
Moser, D.M.
1995-01-01
This technical study reviews the methodology for calculating offsite dose estimates as described in the offsite dose calculation manual (ODCM) for Pennsylvania Power and Light - Susquehanna Steam Electric Station (SSES). An evaluation of the SSES ODCM dose assessment methodology indicates that it conforms with methodology accepted by the US Nuclear Regulatory Commission (NRC). Using 1993 SSES effluent data, dose estimates are calculated according to SSES ODCM methodology and compared to the dose estimates calculated according to SSES ODCM and the computer model used to produce the reported 1993 dose estimates. The 1993 SSES dose estimates are based on the axioms of Publication 2 of the International Commission of Radiological Protection (ICRP). SSES Dose estimates based on the axioms of ICRP Publication 26 and 30 reveal the total body estimates to be the most affected
Regulatory guides for qualifying the calculation methodology of Furnas by CNEN
International Nuclear Information System (INIS)
1987-10-01
Regulatory guides are presented which will be used for qualifying the calculation methodology of FURNAS by CNEN, in the areas of Neutronics, Thermohydraulics, Accident Analysis and Fuel Rod Performance, as applied to Angra 1 NPP. (Author) [pt
Detailed channel thermal-hydraulic calculation of nuclear reactor fuel assemblies
International Nuclear Information System (INIS)
Zhukov, A.V.; Sorokin, A.P.; Ushakov, P.A.; Yur'ev, Yu.S.
1981-01-01
The system of equations of mass balance, quantity of motion and energy used in calculation of nuclear reactor fuel assemblies is obtained. The equation system is obtained on the base of integral equations of hydrodynamics interaction in assemblies of smooth fuel elements and fuel elements with wire packing. The calculation results of coolant heating distributions by the fast reactor assembly channels are presented. The analysis of the results obtained shows that interchannel exchange essentially uniforms the coolant heating distribution in the peripheral range of the assembly but it does not remove non-uniformity caused by power distribution non-uniformity in the cross section. Geometry of the peripheral assembly range plays an essential role in the heating distribution. Change of the calculation gap between the peripheral fuel elements and assembly shells can result either in superheating or in subcooling in the peripheral channels relatively to joint internal channels of the assembly. Heat supply to the coolant passing through interassembly gaps decreases temperature in the assembly periphery and results in the increase of temperature non-uniformity by the perimeter of peripheral fuel elements. It is concluded that the applied method of the channel-by-channel calculation is ef-- fective in thermal-physical calculation of nuclear reactor fuel assemblies and it permits to solve a wide range of problems [ru
International Nuclear Information System (INIS)
Kim, Kyu Tae; Kim, Oh Hwan
1999-01-01
A simplified statistical methodology is developed in order to both reduce over-conservatism of deterministic methodologies employed for PWR fuel rod internal pressure (RIP) calculation and simplify the complicated calculation procedure of the widely used statistical methodology which employs the response surface method and Monte Carlo simulation. The simplified statistical methodology employs the system moment method with a deterministic statistical methodology employs the system moment method with a deterministic approach in determining the maximum variance of RIP. The maximum RIP variance is determined with the square sum of each maximum value of a mean RIP value times a RIP sensitivity factor for all input variables considered. This approach makes this simplified statistical methodology much more efficient in the routine reload core design analysis since it eliminates the numerous calculations required for the power history-dependent RIP variance determination. This simplified statistical methodology is shown to be more conservative in generating RIP distribution than the widely used statistical methodology. Comparison of the significances of each input variable to RIP indicates that fission gas release model is the most significant input variable. (author). 11 refs., 6 figs., 2 tabs
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
Coupled channel calculations for electron-positron pair production in collisions of heavy ions
Gail, M; Scheid, W
2003-01-01
Coupled channel calculations are performed for electron-positron pair production in relativistic collisions of heavy ions. For this purpose the wavefunction is expanded into different types of basis sets consisting of atomic wavefunctions centred around the projectile ion only and around both of the colliding nuclei. The results are compared with experimental data from Belkacem et al (1997 Phys. Rev. A 56 2807).
A methodology for calculating photovoltaic field output and effect of solar tracking strategy
International Nuclear Information System (INIS)
Hu, Yeguang; Yao, Yingxue
2016-01-01
Highlights: • A new methodology for calculating PV field output is proposed. • The reduction of diffuse radiation and albedo due to shading is considered. • The shadow behavior is accurately analyzed at a cell level. • Several simplified measures are taken to reduce the calculation work. • The field outputs with different solar tracking strategies are compared. - Abstract: This paper proposes an effective methodology for calculating the photovoltaic field output. A combination of two methods is first presented for optical performance calculation: point projection method for direction radiation, and Monte Carlo ray-tracing method for both diffuse radiation and albedo radiation. Based on the optical calculation, an accurate output of the photovoltaic field can be obtained through a cell-level simulation of PV system. Several simplified measures are taken to reduce the large amount of calculation work. The proposed methodology has been validated for accurate and fast calculation of field output. With the help of the developed code, this paper deals with the performance comparison between four typical tracking strategies. Through the comparative analysis, the field output is proved to be related to the tracking strategy. For a regular photovoltaic field, the equatorial and elevation-rolling tracking show the superior performance in annual field output to the azimuth-elevation and rolling-elevation tracking. A reasonable explanation for this difference has been presented in this paper.
International Nuclear Information System (INIS)
Talamo, Alberto; Gohar, Y.; Rabiti, C.; Aliberti, G.; Kondev, F.; Smith, D.; Zhong, Z.; Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C.; Serafimovich, I.
2009-01-01
One of the most reliable experimental methods for measuring the subcriticality level of a nuclear fuel assembly is the Sjoestrand method applied to the reaction rate generated from a pulsed neutron source. This study developed a new analytical methodology simulating the Sjoestrand method, which allows comparing the experimental and analytical reaction rates and the obtained subcriticality levels. In this methodology, the reaction rate is calculated due to a single neutron pulse using MCNP/MCNPX computer code or any other neutron transport code that explicitly simulates the delayed fission neutrons. The calculation simulates a single neutron pulse over a long time period until the delayed neutron contribution to the reaction rate is vanished. The obtained reaction rate is then superimposed to itself, with respect to the time, to simulate the repeated pulse operation until the asymptotic level of the reaction rate, set by the delayed neutrons, is achieved. The superimposition of the pulse to itself was calculated by a simple C computer program. A parallel version of the C program is used due to the large amount of data being processed, e.g. by the Message Passing Interface (MPI). The analytical results of this new calculation methodology have shown an excellent agreement with the experimental data available from the YALINA-Booster facility of Belarus. This methodology can be used to calculate Bell and Glasstone spatial correction factor.
Energy Technology Data Exchange (ETDEWEB)
Talamo, Alberto [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: atalamo@anl.gov; Gohar, Y. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Rabiti, C. [Idaho National Laboratory, P.O. Box 2528, Idaho Falls, ID 83403 (United States); Aliberti, G.; Kondev, F.; Smith, D.; Zhong, Z. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C.; Serafimovich, I. [Joint Institute for Power and Nuclear Research-Sosny, National Academy of Sciences (Belarus)
2009-07-21
One of the most reliable experimental methods for measuring the subcriticality level of a nuclear fuel assembly is the Sjoestrand method applied to the reaction rate generated from a pulsed neutron source. This study developed a new analytical methodology simulating the Sjoestrand method, which allows comparing the experimental and analytical reaction rates and the obtained subcriticality levels. In this methodology, the reaction rate is calculated due to a single neutron pulse using MCNP/MCNPX computer code or any other neutron transport code that explicitly simulates the delayed fission neutrons. The calculation simulates a single neutron pulse over a long time period until the delayed neutron contribution to the reaction rate is vanished. The obtained reaction rate is then superimposed to itself, with respect to the time, to simulate the repeated pulse operation until the asymptotic level of the reaction rate, set by the delayed neutrons, is achieved. The superimposition of the pulse to itself was calculated by a simple C computer program. A parallel version of the C program is used due to the large amount of data being processed, e.g. by the Message Passing Interface (MPI). The analytical results of this new calculation methodology have shown an excellent agreement with the experimental data available from the YALINA-Booster facility of Belarus. This methodology can be used to calculate Bell and Glasstone spatial correction factor.
Comparison of different source calculations in two-nucleon channel at large quark mass
Yamazaki, Takeshi; Ishikawa, Ken-ichi; Kuramashi, Yoshinobu
2018-03-01
We investigate a systematic error coming from higher excited state contributions in the energy shift of light nucleus in the two-nucleon channel by comparing two different source calculations with the exponential and wall sources. Since it is hard to obtain a clear signal of the wall source correlation function in a plateau region, we employ a large quark mass as the pion mass is 0.8 GeV in quenched QCD. We discuss the systematic error in the spin-triplet channel of the two-nucleon system, and the volume dependence of the energy shift.
International Nuclear Information System (INIS)
Carluccio, Thiago
2011-01-01
This works had as goal to investigate calculational methodologies on subcritical source driven reactor, such as Accelerator Driven Subcritical Reactor (ADSR) and Fusion Driven Subcritical Reactor (FDSR). Intense R and D has been done about these subcritical concepts, mainly due to Minor Actinides (MA) and Long Lived Fission Products (LLFP) transmutation possibilities. In this work, particular emphasis has been given to: (1) complement and improve calculation methodology with neutronic transmutation and decay capabilities and implement it computationally, (2) utilization of this methodology in the Coordinated Research Project (CRP) of the International Atomic Energy Agency Analytical and Experimental Benchmark Analysis of ADS and in the Collaborative Work on Use of Low Enriched Uranium in ADS, especially in the reproduction of the experimental results of the Yalina Booster subcritical assembly and study of a subcritical core of IPEN / MB-01 reactor, (3) to compare different nuclear data libraries calculation of integral parameters, such as k eff and k src , and differential distributions, such as spectrum and flux, and nuclides inventories and (4) apply the develop methodology in a study that may help future choices about dedicated transmutation system. The following tools have been used in this work: MCNP (Monte Carlo N particle transport code), MCB (enhanced version of MCNP that allows burnup calculation) and NJOY to process nuclear data from evaluated nuclear data files. (author)
Legault, A.; Scott, L.; Rosemann, A.L.P.; Hopkins, M.
2014-01-01
CSA C873 Building Energy Estimation Methodology (BEEM) is a new series of (10) standards that is intended to simplify building energy calculations. The standard is based upon the German DIN Standard 18599 that has 8 years of proven track record and has been modified for the Canadian market. The BEEM
International Nuclear Information System (INIS)
Japiassu, Fernando Parois
2013-01-01
When designing radiotherapy treatment rooms, the dimensions of barriers are established on the basis of American calculation methodologies specifically; NCRP Report N° 49, NCRP Report N° 51, and more recently, NCRP Report N° 151. Such barrier calculations are based on parameters reflecting predictions of treatments to be performed within the room; which, in tum, reftect a specific reality found in a country. There exists, however, a variety of modern radiotherapy techniques, such as Intensity Modulated Radiation Therapy (IMRT); Total Body Irradiation (TBl) and radiosurgery (SRS); where patierits are treated in a much different way than during more conventional treatrnents, which are not taken into account the traditional shielding calculation methodology. This may lead to a faulty design of treattnent rooms. In order to establish a comparison between the methodology used to calculate shielding design and the reality of treatments performed in Brazil, two radiotherapy facilitie were selected, both of them offering traditional and modern treatment techniqued as described above. Data in relation with reatments perfotmed over a period of six (6)months of operations in both institutions were collected. Based on tlis informaton, a new set of realistic parameters required for shielding design was estãblished, whicb in turn allowed for a nwe caculation of barrier thickness for both facilities. The barrier thickness resultaing from this calculation was then compared with the barrier thickness propose as part of the original shielding design, approved by the regulatory authority. First, concerning the public facility, the thickness of all primary barriers proposed in the shielding design was actually larger than the thickness resulting from calculations based on realistic parameters. Second, concerning the private facility, the new data show that the thickness of three out of the four primary barriers described in the project is larger than the thickness oresulting from
International Nuclear Information System (INIS)
Rossini, M.R.
1992-01-01
An attempt has been made to obtain a strategy coherent with the available instruments and that could be implemented with future developments. A calculation methodology was developed for fuel reload in PWR reactors, which evolves cell calculation with the HAMMER-TECHNION code and neutronics calculation with the CITATION code.The management strategy adopted consists of fuel element position changing at the beginning of each reactor cycle in order to decrease the radial peak factor. The bi-dimensional, two group First Order perturbation theory was used for the mathematical modeling. (L.C.J.A.)
International Nuclear Information System (INIS)
Amin, E.; Hathout, A.M.; Shouman, S.
1997-01-01
The kyoto university reactor physics experiments on the university critical assembly is used to benchmark validate the NCNSRC calculations methodology. This methodology has two lines, diffusion and Monte Carlo. The diffusion line includes the codes WIMSD4 for cell calculations and the two dimensional diffusion code DIXY2 for core calculations. The transport line uses the MULTIKENO-Code vax Version. Analysis is performed for the criticality, and the temperature coefficients of reactivity (TCR) for the light water moderated and reflected cores, of the different cores utilized in the experiments. The results of both Eigen value and TCR approximately reproduced the experimental and theoretical Kyoto results. However, some conclusions are drawn about the adequacy of the standard wimsd4 library. This paper is an extension of the NCNSRC efforts to assess and validate computer tools and methods for both Et-R R-1 and Et-MMpr-2 research reactors. 7 figs., 1 tab
International Nuclear Information System (INIS)
Vasko, Marek; Daniska, Vladimir; Rehak, Ivan; Necas, Vladimir
2011-01-01
Calculation of personnel exposure is a one of the main parameters being evaluated within the pre-decommissioning plans together with other decommissioning drivers such as costs, manpower, amounts of RAW and conventional waste and amount of discharged gaseous and liquid effluents. Alongside with manpower, the exposure is an indicator of the decommissioning process for need of staff, and quantifies impact of decommissioning on personnel from the radio hygienic point of view. At the same time it indicates suitability of individual work procedures use for decommissioning activities. For this reason it is important to estimate as precise as possible demands on personnel exposure even during preparatory decommissioning phase to quantify impact of decommissioning on personnel and eventually optimize the decommissioning process, if needed. The most appropriate way of staff exposure estimation during decommissioning preparatory phases is its calculation based on radiological and physical characteristics of equipment to be decommissioned and also quantitative and qualitative characterisation of typical decommissioning activities. On one hand, the methodology of exposure calculation should allow as much as possible realistic description and algorithmisation of exposure ways during decommissioning activities. On the other hand the calculation have to be systematic, well-arranged and clearly definable by appropriate mathematic relations. Calculation can be made by various approaches using more or less sophisticated software solutions from classic MS Excel sheets up to the complex calculation codes. In this paper, a methodology used for personnel exposure calculation and optimization implemented within the complex computer code OMEGA developed at DECOM, a.s. is described. (author)
International Nuclear Information System (INIS)
Gomes, Renato G.; Rebello, Wilson F.; Vellozo, Sergio O.; Junior, Luis M.; Vital, Helio C.; Rusin, Tiago; Silva, Ademir X.
2013-01-01
MCNPX simulations have been performed in order to calculate dose rates as well as spectra along the four experimental channels of the gamma irradiating facility at the Technology Center of the Brazilian Army (CTEx). Safety, operational and research requirements have led to the need to determine both the magnitude and spectra of the leaking gamma fluxes. The CTEx experimental facility is cavity type with a moveable set of 28 horizontally positioned rods, filled with Cesium-137 chloride and doubly encased in stainless steel that yields an approximately plane 42 kCi-source that provides a maximum dose rate of about 1.5 kG/h into two irradiating chambers. The channels are intended for irradiation tests outside facility. They would allow larger samples to be exposed to lower gamma dose rates under controlled conditions. Dose rates have been calculated for several positions inside the channels as well as at their exits. In addition, for purposes related to the safety of operators and personnel, the angles submitted by the exiting beams have also been evaluated as they spread when leaving the channels. All calculations have been performed by using a computational model of the CTEx facility that allows its characteristics and operation to be accurately simulated by using the Monte Carlo Method. Virtual dosimeters filled with Fricke (ferrous sulfate) were modeled and positioned throughout 2 vertical channels (top and bottom) and 2 horizontal ones (front and back) in order to map dose rates and gamma spectrum distributions. The calculations revealed exiting collimated beams in the order of tenths of Grays per minute as compared to the maximum 25 Gy / min dose rate in the irradiator chamber. In addition, the beams leaving the two vertical channels were found to exhibit a widespread cone-shaped distribution with aperture angle ranging around 85 deg. The data calculated in this work are intended for use in the design of optimized experiments (better positioning of samples and
Practical methodologies for the calculation of capacity in electricity markets for wind energy
International Nuclear Information System (INIS)
Botero B, Sergio; Giraldo V, Luis Alfonso; Isaza C, Felipe
2008-01-01
Determining the real capacity of the generators in a power market is an essential task in order to estimate the actual system reliability, and to estimate the reward for generators due to their capacity in the firm energy market. In the wind power case, which is an intermittent resource, several methodologies have been proposed to estimate the capacity of a wind power emplacement, not only for planning but also for firm energy remuneration purposes. This paper presents some methodologies that have been proposed or implemented around the world in order to calculate the capacity of this energy resource.
SALLY - a computer programme for the calculation of the dynamical behaviour of a cooling channel
International Nuclear Information System (INIS)
Reiche, C.; Ziegenbein, D.
1978-12-01
This report describes the mathematical-physical fundamentals and provides a user's manual as well as some test examples for the programme SALLY. SALLY is suitable for the calculation of the dynamical behaviour of a cooling channel under following conditions: point-kinetics, heat transfer in the fuel in radial direction only, reactivity feedback, simple model of the first cooling cycle. Reactivity, coolant inlet temperature or coolant velocity can be disturbed. (author)
CALCULATION METHODS OF OPTIMAL ADJUSTMENT OF CONTROL SYSTEM THROUGH DISTURBANCE CHANNEL
Directory of Open Access Journals (Sweden)
I. M. Golinko
2014-01-01
Full Text Available In the process of automatic control system debugging the great attention is paid to determining formulas’ parameters of optimal dynamic adjustment of regulators, taking into account the dynamics of Objects control. In most cases the known formulas are oriented on design of automatic control system through channel “input-output definition”. But practically in all continuous processes the main task of all regulators is stabilization of output parameters. The Methods of parameters calculation for dynamic adjustment of regulations were developed. These methods allow to optimize the analog and digital regulators, taking into account minimization of regulated influences. There were suggested to use the fact of detuning and maximum value of regulated influence. As the automatic control system optimization with proportional plus reset controllers on disturbance channel is an unimodal task, the main algorithm of optimization is realized by Hooke – Jeeves method. For controllers optimization through channel external disturbance there were obtained functional dependences of parameters calculations of dynamic proportional plus reset controllers from dynamic characteristics of Object control. The obtained dependences allow to improve the work of controllers (regulators of automatic control on external disturbance channel and so it allows to improve the quality of regulation of transient processes. Calculation formulas provide high accuracy and convenience in usage. In suggested method there are no nomographs and this fact expels subjectivity of investigation in determination of parameters of dynamic adjustment of proportional plus reset controllers. Functional dependences can be used for calculation of adjustment of PR controllers in a great range of change of dynamic characteristics of Objects control.
International Nuclear Information System (INIS)
Karriem, Z.; Zamonsky, O.M.
2014-01-01
The South African Nuclear Energy Corporation SOC Ltd (Necsa) is a state owned nuclear facility which owns and operates SAFARI-1, a 20 MW material testing reactor. SAFARI-1 is a multi-purpose reactor and is used for the production of radioisotopes through in-core sample irradiation. The Radiation and Reactor Theory (RRT) Section of Necsa supports SAFARI-1 operations with nuclear engineering analyses which include core-reload design, core-follow and radiation transport analyses. The primary computer codes that are used for the analyses are the OSCAR-4 nodal diffusion core simulator and the Monte Carlo transport code MCNP. RRT has developed a calculation methodology based on OSCAR-4 and MCNP to simulate the diverse in-core irradiation conditions in SAFARI-1, for the purpose of radioisotope production. In this paper we present the OSCAR-4/MCNP calculation methodology and the software tools that were developed for rapid and reliable construction of MCNP analysis models. The paper will present the application and accuracy of the methodology for the production of yttrium-90 ( 90 Y) and will include comparisons between calculation results and experimental measurements. The paper will also present sensitivity analyses that were performed to determine the effects of control rod bank position, representation of core depletion state and sample loading configuration, on the calculated 90 Y sample activity. (author)
Coupled channel calculations of K-shell ionization in asymmetric collision systems
International Nuclear Information System (INIS)
Mehler, G.; Greiner, W.; Soff, G.
1986-07-01
We report theoretical results on K-shell ionization for a variety of asymmetric collision systems. The calculated ionization rates are compared with experimental data. The coupled channel formalism underlying these calculations is presented. It is based on a set of relativistic target centred states, taking a screened potential of Dirac-Fock-Slater type into account. We discuss the effects of different matrix elements, e.g. continuum-continuum couplings. The binding effect is inherently contained in our approach and described in a dynamical way. (orig.)
Directory of Open Access Journals (Sweden)
N. A. Kiselev
2017-01-01
Full Text Available The paper analyses a technique to calculate the Leontiev tube and shows that there are several ways to increase operating efficiency of this device of gas-dynamic energy separation. Application of regular relief (dimples and protrusions on the wall between supersonic and subsonic channels is one of them.Analyses the results available in publications of experimentally numerically investigated influence of semi-spherical protrusions in the slot channels on the enhancement of heat transfer and drag coefficients at various Reynolds numbers.Shows that at the laminar flow owing to semi-spherical protrusions in the slot channel a heat transfer coefficient can be 1.1‑2.6 times increased with simultaneous 1.7‑4.8 times growth of drag coefficient (as compared to the smooth channel.At transition and turbulent flows the heat transfer enhancement, because of shallow dimples (depth-to-print diameter ratio is from 0.1 to 0.25, can reach 1.1‑2.4 times, with simultaneous 1.2‑7.9 times growth of the drag coefficient (as compared to smooth channel.Using the higher protrusions can provide up to 3.0‑3.5 times heat transfer intensification, but in this case there is an outrunning growth of the drag coefficient.It is shown that the staggered array of the shallow spherical protrusions is advisable to use for heat transfer enhancement in the subsonic channel of the Leontiev tube. The shallow spherical dimples correspond to them and operate as heat transfer intensifiers in the supersonic channel.The paper proposes a mechanism that enables taking into consideration an impact of the protrusions in the slot channel on the intensification of the heat transfer and momentum processes when calculating the gas-dynamic energy separation device (Leontiev tube using the known (earlier published technique.The study has been implemented under supporting Grant no. 15-08-08428 of the Russian Foundation for Basic Research.
Development of a Seismic Setpoint Calculation Methodology Using a Safety System Approach
International Nuclear Information System (INIS)
Lee, Chang Jae; Baik, Kwang Il; Lee, Sang Jeong
2013-01-01
The Automatic Seismic Trip System (ASTS) automatically actuates reactor trip when it detects seismic activities whose magnitudes are comparable to a Safe Shutdown Earthquake (SSE), which is the maximum hypothetical earthquake at the nuclear power plant site. To ensure that the reactor is tripped before the magnitude of earthquake exceeds the SSE, it is crucial to reasonably determine the seismic setpoint. The trip setpoint and allowable value for the ASTS for Advanced Power Reactor (APR) 1400 Nuclear Power Plants (NPPs) were determined by the methodology presented in this paper. The ASTS that trips the reactor when a large earthquake occurs is categorized as a non safety system because the system is not required by design basis event criteria. This means ASTS has neither specific analytical limit nor dedicated setpoint calculation methodology. Therefore, we developed the ASTS setpoint calculation methodology by conservatively considering that of PPS. By incorporating the developed methodology into the ASTS for APR1400, the more conservative trip setpoint and allowable value were determined. In addition, the ZPA from the Operating Basis Earthquake (OBE) FRS of the floor where the sensor module is located is 0.1g. Thus, the allowance of 0.17g between OBE of 0.1 g and ASTS trip setpoint of 0.27 g is sufficient to prevent the reactor trip before the magnitude of the earthquake exceeds the OBE. In result, the developed ASTS setpoint calculation methodology is evaluated as reasonable in both aspects of the safety and performance of the NPPs. This will be used to determine the ASTS trip setpoint and allowable for newly constructed plants
Calculation and evaluation methodology of the flawed pipe and the compute program development
International Nuclear Information System (INIS)
Liu Chang; Qian Hao; Yao Weida; Liang Xingyun
2013-01-01
Background: The crack will grow gradually under alternating load for a pressurized pipe, whereas the load is less than the fatigue strength limit. Purpose: Both calculation and evaluation methodology for a flawed pipe that have been detected during in-service inspection is elaborated here base on the Elastic Plastic Fracture Mechanics (EPFM) criteria. Methods: In the compute, the depth and length interaction of a flaw has been considered and a compute program is developed per Visual C++. Results: The fluctuating load of the Reactor Coolant System transients, the initial flaw shape, the initial flaw orientation are all accounted here. Conclusions: The calculation and evaluation methodology here is an important basis for continue working or not. (authors)
Development of 3D pseudo pin-by-pin calculation methodology in ANC
International Nuclear Information System (INIS)
Zhang, B.; Mayhue, L.; Huria, H.; Ivanov, B.
2012-01-01
Advanced cores and fuel assembly designs have been developed to improve operational flexibility, economic performance and further enhance safety features of nuclear power plants. The simulation of these new designs, along with strong heterogeneous fuel loading, have brought new challenges to the reactor physics methodologies currently employed in the industrial codes for core analyses. Control rod insertion during normal operation is one operational feature in the AP1000 R plant of Westinghouse next generation Pressurized Water Reactor (PWR) design. This design improves its operational flexibility and efficiency but significantly challenges the conventional reactor physics methods, especially in pin power calculations. The mixture loading of fuel assemblies with significant neutron spectrums causes a strong interaction between different fuel assembly types that is not fully captured with the current core design codes. To overcome the weaknesses of the conventional methods, Westinghouse has developed a state-of-the-art 3D Pin-by-Pin Calculation Methodology (P3C) and successfully implemented in the Westinghouse core design code ANC. The new methodology has been qualified and licensed for pin power prediction. The 3D P3C methodology along with its application and validation will be discussed in the paper. (authors)
International Nuclear Information System (INIS)
Santos, Rubens Souza dos; Martinez, Aquilino Senra; Alvim, Antonio Carlos Marques
2002-01-01
In this work is presented a methodology which focuses the distribution of neutron absorber rods in nuclear reactor power plants, for utilizing in space kinetic calculations, principally in the cluster ejection transients of control rods. A numerical model for macroscopic constant calculations based on the knowledge of the neutron flux without the control rods is proposed, as alternative to the analytical models, based on the hypothesis of the null current on the cell super boundaries. The proposed model in this work has itself showed adequate to deal with problems with strong space dependence, once that the model showed consistence in the global average built in the analytical model. (author)
Konovodov, V. V.; Valentov, A. V.; Kukhar, I. S.; Retyunskiy, O. Yu; Baraksanov, A. S.
2016-08-01
The work proposes the algorithm to calculate strength under alternating stresses using the developed methodology of building the diagram of limiting stresses. The overall safety factor is defined by the suggested formula. Strength calculations of components working under alternating stresses in the great majority of cases are conducted as the checking ones. It is primarily explained by the fact that the overall fatigue strength reduction factor (Kσg or Kτg) can only be chosen approximately during the component design as the engineer at this stage of work has just the approximate idea on the component size and shape.
Calculating the electron temperature in the lightning channel by continuous spectrum
Xiangcheng, DONG; Jianhong, CHEN; Xiufang, WEI; Ping, YUAN
2017-12-01
Based on the theory of plasma continuous radiation, the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained. During the development process of a return stroke of ground flash, the intensity of continuous radiation spectrum is separated on the basis of the spectrums with obviously different luminous intensity at two moments. The electron temperature of the lightning discharge channel is obtained through the curve fitting of the continuous spectrum intensity. It is found that electron temperature increases with the increase of wavelength and begins to reduce after the peak. The peak temperature of the two spectra is close to 25 000 K. To be compared with the result of discrete spectrum, the electron temperature is fitted by the O I line and N II line of the spectrum respectively. The comparison shows that the high temperature value is in good agreement with the temperature of the lightning core current channel obtained from the ion line information, and the low temperature at the high band closes to the calculation result of the atomic line, at a low band is lower than the calculation of the atomic line, which reflects the temperature of the luminous channel of the outer corona.
Techniques for heavy-ion coupled-channels calculations. I. Long-range Coulomb coupling
International Nuclear Information System (INIS)
Rhoades-Brown, M.; Macfarlane, M.H.; Pieper, S.C.
1980-01-01
Direct-reaction calculations for heavy ions require special computational techniques that take advantage of the physical peculiarities of heavy-ion systems. This paper is the first of a series on quantum-mechanical coupled-channels calculations for heavy ions. It deals with the problems posed by the long range of the Coulomb coupling interaction. Our approach is to use the Alder-Pauli factorization whereby the channel wave functions are expressed as products of Coulomb functions and modulating amplitudes. The equations for the modulating amplitudes are used to integrate inwards from infinity to a nuclear matching radius ( approx. = 20 fm). To adequate accuracy, the equations for the amplitudes can be reduced to first order and solved in first Born approximation. The use of the Born approximation leads to rapid recursion relations for the solutions of the Alder-Pauli equations and hence to a great reduction in computational labor. The resulting coupled-channels Coulomb functions can then be matched in the usual way to solutions of the coupled radial equations in the interior region of r space. Numerical studies demonstrate the reliability of the various techniques introduced
Ben Mosbah, Abdallah
In order to improve the qualities of wind tunnel tests, and the tools used to perform aerodynamic tests on aircraft wings in the wind tunnel, new methodologies were developed and tested on rigid and flexible wings models. A flexible wing concept is consists in replacing a portion (lower and/or upper) of the skin with another flexible portion whose shape can be changed using an actuation system installed inside of the wing. The main purpose of this concept is to improve the aerodynamic performance of the aircraft, and especially to reduce the fuel consumption of the airplane. Numerical and experimental analyses were conducted to develop and test the methodologies proposed in this thesis. To control the flow inside the test sections of the Price-Paidoussis wind tunnel of LARCASE, numerical and experimental analyses were performed. Computational fluid dynamics calculations have been made in order to obtain a database used to develop a new hybrid methodology for wind tunnel calibration. This approach allows controlling the flow in the test section of the Price-Paidoussis wind tunnel. For the fast determination of aerodynamic parameters, new hybrid methodologies were proposed. These methodologies were used to control flight parameters by the calculation of the drag, lift and pitching moment coefficients and by the calculation of the pressure distribution around an airfoil. These aerodynamic coefficients were calculated from the known airflow conditions such as angles of attack, the mach and the Reynolds numbers. In order to modify the shape of the wing skin, electric actuators were installed inside the wing to get the desired shape. These deformations provide optimal profiles according to different flight conditions in order to reduce the fuel consumption. A controller based on neural networks was implemented to obtain desired displacement actuators. A metaheuristic algorithm was used in hybridization with neural networks, and support vector machine approaches and their
Accurate Bit Error Rate Calculation for Asynchronous Chaos-Based DS-CDMA over Multipath Channel
Kaddoum, Georges; Roviras, Daniel; Chargé, Pascal; Fournier-Prunaret, Daniele
2009-12-01
An accurate approach to compute the bit error rate expression for multiuser chaosbased DS-CDMA system is presented in this paper. For more realistic communication system a slow fading multipath channel is considered. A simple RAKE receiver structure is considered. Based on the bit energy distribution, this approach compared to others computation methods existing in literature gives accurate results with low computation charge. Perfect estimation of the channel coefficients with the associated delays and chaos synchronization is assumed. The bit error rate is derived in terms of the bit energy distribution, the number of paths, the noise variance, and the number of users. Results are illustrated by theoretical calculations and numerical simulations which point out the accuracy of our approach.
International Nuclear Information System (INIS)
Garcia, A.E.; Parkansky, D.G.
1993-01-01
In the Embalse nuclear power plant (CNE), the Regional Overpower Protection System acting on the Shutdown Systems number 1 and number 2 protects the reactor against overpowers in the reactor field for a localized peaking or a power increase in the reactor as a whole. This report summarizes the results of the critical channel power calculation for the time average powers configuration for the 380 reactor field channels. The final purpose of this work is to analyze and eventually modify the detector set points. Other reactor configurations are being analyzed. The report also presents a sensitivity analysis in order to evaluate potential sources of error and uncertainties which could affect the ROP performance. (author)
International Nuclear Information System (INIS)
Zhong, Z.; Gohar, Y.; Talamo, A.
2009-01-01
Argonne National Laboratory (ANL) of USA and Kharkov Inst. of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an electron accelerator driven subcritical facility (ADS). The facility will be utilized for basic research, medical isotopes production, and training young nuclear specialists. The burnup methodology and analysis of the KIPT ADS are presented in this paper. MCNPX and MCB Monte Carlo computer codes have been utilized. MCNPX has the capability of performing electron, photon and neutron coupled transport problems, but it lacks the burnup capability for driven subcritical systems. MCB has the capability for performing the burnup calculation of driven subcritical systems, while it cannot transport electrons. A calculational methodology coupling MCNPX and MCB has been developed, which can exploit the electrons transport capability of MCNPX for neutron production and the burnup capability of MCB for driven subcritical systems. In this procedure, a neutron source file is generated using MCNPX transport calculation, preserving the neutrons yield from photonuclear reactions initiated by electrons, and this source file is utilized by MCB for the burnup analyses with the same geometrical model. In this way, the ADS depletion calculation can be accurately. (authors)
Development of a calculation methodology for potential flow over irregular topographies
International Nuclear Information System (INIS)
Del Carmen, Alejandra F.; Ferreri, Juan C.; Boutet, Luis I.
2003-01-01
Full text: Computer codes for the calculation of potential flow fields over surfaces with irregular topographies have been developed. The flows past multiple simple obstacles and past the neighboring region of the Embalse Nuclear Power Station have been considered. The codes developed allow the calculation of velocities quite near the surface. It, in turn, imposed developing high accuracy techniques. The Boundary Element Method, using a linear approximation on triangular plane elements and an analytical integration methodology has been applied. A particular and quite efficient technique for the calculation of the solid angle at each node vertex was also considered. The results so obtained will be applied to predict the dispersion of passive pollutants coming from discontinuous emissions. (authors)
42 CFR 484.230 - Methodology used for the calculation of the low-utilization payment adjustment.
2010-10-01
... 42 Public Health 5 2010-10-01 2010-10-01 false Methodology used for the calculation of the low... Prospective Payment System for Home Health Agencies § 484.230 Methodology used for the calculation of the low... amount is determined by using cost data set forth in § 484.210(a) and adjusting by the appropriate wage...
Site-specific electronic structure analysis by channeling EELS and first-principles calculations.
Tatsumi, Kazuyoshi; Muto, Shunsuke; Yamamoto, Yu; Ikeno, Hirokazu; Yoshioka, Satoru; Tanaka, Isao
2006-01-01
Site-specific electronic structures were investigated by electron energy loss spectroscopy (EELS) under electron channeling conditions. The Al-K and Mn-L(2,3) electron energy loss near-edge structure (ELNES) of, respectively, NiAl2O4 and Mn3O4 were measured. Deconvolution of the raw spectra with the instrumental resolution function restored the blunt and hidden fine features, which allowed us to interpret the experimental spectral features by comparing with theoretical spectra obtained by first-principles calculations. The present method successfully revealed the electronic structures specific to the differently coordinated cationic sites.
Li, Changping
2014-11-10
In this report, we propose a fast numerical solution for the steady state radiative transfer equation in order to calculate the path loss due to light absorption and scattering in various type of underwater channels. In the proposed scheme, we apply a direct non-uniform method to discretize the angular space and an upwind type finite difference method to discretize the spatial space. A Gauss-Seidel iterative method is then applied to solve the fully discretized system of linear equations. The accuracy and efficiency of the proposed scheme is validated by Monte Carlo simulations.
Li, Changping; Park, Ki-Hong; Alouini, Mohamed-Slim
2014-01-01
In this report, we propose a fast numerical solution for the steady state radiative transfer equation in order to calculate the path loss due to light absorption and scattering in various type of underwater channels. In the proposed scheme, we apply a direct non-uniform method to discretize the angular space and an upwind type finite difference method to discretize the spatial space. A Gauss-Seidel iterative method is then applied to solve the fully discretized system of linear equations. The accuracy and efficiency of the proposed scheme is validated by Monte Carlo simulations.
International Nuclear Information System (INIS)
Hoseyni, Seyed Mohsen; Pourgol-Mohammad, Mohammad; Tehranifard, Ali Abbaspour; Yousefpour, Faramarz
2014-01-01
This paper describes a systematic framework for characterizing important phenomena and quantifying the degree of contribution of each parameter to the output in severe accident uncertainty assessment. The proposed methodology comprises qualitative as well as quantitative phases. The qualitative part so called Modified PIRT, being a robust process of PIRT for more precise quantification of uncertainties, is a two step process for identifying and ranking based on uncertainty importance in severe accident phenomena. In this process identified severe accident phenomena are ranked according to their effect on the figure of merit and their level of knowledge. Analytical Hierarchical Process (AHP) serves here as a systematic approach for severe accident phenomena ranking. Formal uncertainty importance technique is used to estimate the degree of credibility of the severe accident model(s) used to represent the important phenomena. The methodology uses subjective justification by evaluating available information and data from experiments, and code predictions for this step. The quantitative part utilizes uncertainty importance measures for the quantification of the effect of each input parameter to the output uncertainty. A response surface fitting approach is proposed for estimating associated uncertainties with less calculation cost. The quantitative results are used to plan in reducing epistemic uncertainty in the output variable(s). The application of the proposed methodology is demonstrated for the ACRR MP-2 severe accident test facility. - Highlights: • A two stage framework for severe accident uncertainty analysis is proposed. • Modified PIRT qualitatively identifies and ranks uncertainty sources more precisely. • Uncertainty importance measure quantitatively calculates effect of each uncertainty source. • Methodology is applied successfully on ACRR MP-2 severe accident test facility
International Nuclear Information System (INIS)
Ondra, Frantisek; Vasko, Marek; Necas, Vladimir
2012-01-01
The article presents methodology of external exposure calculation for reuse of conditional released materials from decommissioning using VISIPLAN 3D ALARA planning tool. Production of rails has been used as an example application of proposed methodology within the CONRELMAT project. The article presents a methodology for determination of radiological, material, organizational and other conditions for conditionally released materials reuse to ensure that workers and public exposure does not breach the exposure limits during scenario's life cycle (preparation, construction and operation of scenario). The methodology comprises a proposal of following conditions in the view of workers and public exposure: - radionuclide limit concentration of conditionally released materials for specific scenarios and nuclide vectors, - specific deployment of conditionally released materials eventually shielding materials, workers and public during the scenario's life cycle, - organizational measures concerning time of workers or public stay in the vicinity on conditionally released materials for individual performed scenarios and nuclide vectors. The above mentioned steps of proposed methodology have been applied within the CONRELMAT project. Exposure evaluation of workers for rail production is introduced in the article as an example of this application. Exposure calculation using VISIPLAN 3D ALARA planning tool was done within several models. The most exposed profession for scenario was identified. On the basis of this result, an increase of radionuclide concentration in conditional released material was proposed more than two times to 681 Bq/kg without no additional safety or organizational measures being applied. After application of proposed safety and organizational measures (additional shielding, geometry changes and limitation of work duration) it is possible to increase concentration of radionuclide in conditional released material more than ten times to 3092 Bq/kg. Storage
Methodological advances in unit cost calculation of psychiatric residential care in Spain.
Moreno, Karen; Sanchez, Eduardo; Salvador-Carulla, Luis
2008-06-01
The care of the severe mentally ill who need intensive support for their daily living (dependent persons), accounts for an increasingly large proportion of public expenditure in many European countries. The main aim of this study was the design and implementation of solid methodology to calculate unit costs of different types of care. To date, methodologies used in Spain have produced inaccurate figures, suggesting few variations in patient consumption of the same service. An adaptation of the Activity-Based-Costing methodology was applied in Navarre, a region in the North of Spain, as a pilot project for the public mental health services. A unit cost per care process was obtained for all levels of care considered in each service during 2005. The European Service Mapping Schedule (ESMS) codes were used to classify the services for later comparisons. Finally, in order to avoid problems of asymmetric cost distribution, a simple Bayesian model was used. As an illustration, we report the results obtained for long-term residential care and note that there are important variations between unit costs when considering different levels of care. Considering three levels of care (Level 1-low, Level 2-medium and Level 3-intensive), the cost per bed in Level 3 was 10% higher than that of Level 2. The results obtained using the cost methodology described provide more useful information than those using conventional methods, although its implementation requires much time to compile the necessary information during the initial stages and the collaboration of staff and managers working in the services. However, in some services, if no important variations exist in patient care, another method would be advisable, although our system provides very useful information about patterns of care from a clinical point of view. Detailed work is required at the beginning of the implementation in order to avoid the calculation of distorted figures and to improve the levels of decision making
New methodology for analytical calculation of resonance integrals in an heterogeneous medium
International Nuclear Information System (INIS)
Campos, T.P.R. de; Martinez, A.S.
1986-01-01
A new methodology for analytical calculation of Resonance Integral in a typical fuel cell is presented. The expression obtained for the Resonance Integral presents the advantage of being analytical. Its constituent terms are combinations of the well known function J(xi,β) with its partial derivatives in regard to β. This is a general expression for all types of resonance. The parameters used in this method depend on the resonance type and are obtained as a function of the parameter lambda. A simple expression, depending on resonance parameters is proposed for this variable. (Author) [pt
A new LHC search channel for a light Higgs boson and associated QCD calculations
International Nuclear Information System (INIS)
Rubin, Mathieu
2010-01-01
This thesis addresses various topics related to LHC studies and predictions. We were first interested in a boosted (p t ≥ 200 GeV) light Higgs boson at the LHC (M H ∼ 120 GeV) in the pp →WH and pp → ZH search channels with H → bb-bar. We showed how these challenging channels can be recovered as promising search channels using a subject analysis procedure in two steps: a 'mass-drop' analysis, which allows one to reduce the large QCD backgrounds, and a 'filtering' analysis, which improves the resolution on the reconstructed Higgs jet mass. Then we focused on the filtering analysis, which allows one to suppress the diffuse background from the underlying-event and pile-up, which are mainly responsible for the bad Higgs mass resolution. We optimized its parameters using semi-analytical calculations which led us to examine the structure of the non-global logarithms that appear in this problem. Finally, we studied some processes whose perturbative series converges poorly at next-to-leading (NLO) order for some observables, a property that we had noticed in the Z+jet and W+jet processes at high-p t during our Higgs analysis. This is important because it leads to questions about the reliability of the predictions resulting from perturbative calculations. It thus becomes necessary to examine higher-order corrections. The method that we developed, called 'LoopSim', consists in approximating these higher order corrections by merging different orders of perturbation theory such that all infra-red and collinear divergences are cancelled. (author)
First principles calculations using density matrix divide-and-conquer within the SIESTA methodology
International Nuclear Information System (INIS)
Cankurtaran, B O; Gale, J D; Ford, M J
2008-01-01
The density matrix divide-and-conquer technique for the solution of Kohn-Sham density functional theory has been implemented within the framework of the SIESTA methodology. Implementation details are provided where the focus is on the scaling of the computation time and memory use, in both serial and parallel versions. We demonstrate the linear-scaling capabilities of the technique by providing ground state calculations of moderately large insulating, semiconducting and (near-) metallic systems. This linear-scaling technique has made it feasible to calculate the ground state properties of quantum systems consisting of tens of thousands of atoms with relatively modest computing resources. A comparison with the existing order-N functional minimization (Kim-Mauri-Galli) method is made between the insulating and semiconducting systems
Methodology of structural integrity assesment of CANDU-6 NPP fuel channels
International Nuclear Information System (INIS)
Radu, Vasile
2004-01-01
The paper describes the methodology of assessing the structural integrity in the CANDU-6 fuel channels making use of alternative methods of evaluation. An evaluation of the structural integrity of a CANDU-6 pressure tube made of Zr-2,5%Nb presenting both sharp and blunted defects is done. These analyses are made in compliance with the Canadian guide 'Pressure Tubes Fitness-for-service', and other two Recognizing procedures internationally adopted: the British procedure R6/Rev.4 and the American procedure API 579. Previously, the data base containing the data on materials property as well as the heat and dynamical loads in normal operation in CANDU-6 pressure tubes was established. Obtaining complete diagrams for structural integrity of pressure tubes with sharp and blunted defects in conditions of normal operation and long-term irradiation is the next step of the methodology to be developed. Modelling sharp and blunted defects on the inner side of pressure tubes, which can occur in normal reactor operating conditions is achieved by means of capabilities of pre-processing of two finite element analysis codes namely FEA-Crack and FEA-Flaw. The second part of the work deals with the analyses by finite element method of the fracture mechanics by means of the FEA-Crack code and with the evaluation of sharp and blunted defects by FAD diagrams in compliance with the British procedure R6/Rev.4. For typical models of blunted defects and thermo-mechanical loads specific to normal operation finite element analyses by FEA-Flaw codes were performed. Then FAD-iDHC diagrams were constructed to evaluate the initiation of the slow cracking under hydrogen/deuterium absorption, the known phenomenon of delayed hydride cracking (DHC)
International Nuclear Information System (INIS)
Licks, Leticia A.; Pires, Marcal
2008-01-01
This work intends to evaluate the emissions of carbon dioxide (CO 2 ) emitted by the burning of fossil coal in Brazil. So, a detailed methodology is proposed for calculation of CO 2 emissions from the carbon emission coefficients specific for the Brazilian carbons. Also, the using of secondary fuels (fuel oil and diesel oil) were considered and the power generation for the calculation of emissions and efficiencies of each power plant as well. The obtained results indicate carbon emissions for the year 2002 approximately of the order of 1,794 Gg, with 20% less than the obtained by the official methodology (MCT). Such differences are related to the non consideration of the humidity containment of the coals as well as the using of generic coefficients not adapted to the Brazilian coals. The obtained results indicate the necessity to review the emission inventories and the modernization of the burning systems aiming the increase the efficiency and reduction of the CO 2 and other pollutants, as an alternative for maintaining the sustainable form of using the fossil coal in the country
Methodology and conclusions of activation calculations of WWER-440 type nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Babcsány, Boglárka, E-mail: boglarka.babcsany@reak.bme.hu; Czifrus, Szabolcs; Fehér, Sándor
2015-04-01
Highlights: • Activation calculation of two WWER-440 type nuclear power plants. • Detailed description of the applied activation calculation methodology. • Graphical results for total activity and waste index categorization. • General conclusions for activation applicable in the case of PWR reactors. - Abstract: Activation calculations for two nuclear power plants of WWER-440 type have been performed by the authors in order to assist the decommissioning planning by assessing the radioactive inventory present at the time of and at different times after the final shutdown. According to related international literature and studies performed earlier by the authors, considering the activity more than 99% of this inventory is concentrated in the materials directly surrounding the reactor core, where the predominant evolution of radionuclides is generated by neutron induced nuclear reactions. In order to obtain the highest possible accuracy in modelling, three-dimensional Monte Carlo neutron transport calculations were performed. Besides the methods and models applied to these analyses, the paper also summarizes the results that can be generally applied to such nuclear power plant types. At the time of shutdown, the total activity of the stainless steel components is about 6 × 10{sup 16} Bq and 1.3 × 10{sup 17} Bq for the two NPPs considered. The biological shielding concrete constitutes approximately 7 × 10{sup 13} Bq and 1.1 × 10{sup 14} Bq.
International Nuclear Information System (INIS)
Zubelzu, Sergio; Álvarez, Roberto
2015-01-01
In this paper we present a methodology for calculating the carbon footprint of the industrial sector during the urban planning stage in order to clearly develop and implement preventive measures. The methodology created focuses on industrial urban planning procedures and takes into account urban infrastructure in the characterization of GHG emissions. It allows for the implementation of preventive measures based on sustainability design criteria. The methodology was derived for specific industrial activity categories and was tested on a group of municipalities in a province south of Madrid, Spain. The results indicate that the average carbon footprint of industrial activities varies between 137.36 kgCO 2eq /m 2 e and 607.25 kgCO 2eq /m 2 e depending on the activity. Gas and electricity are the most important emissions sources for the most polluting industrial activities (chemical and nonmetal mineral products), while transportation is the most important source for every other activity. Municipalities can have a decisive influence on the industrial carbon footprint because, except for waste management and two industrial activities related to electricity, the majority of reductions can be achieved through urban planning decision variables. -- Highlights: •Model to calculate industrial carbon footprint in urban planning stage is proposed. •Specific industrial activities planned have a strong effect on carbon footprint. •Gas and electricity are the most relevant sources for the most pollutant industries. •Transport is relevant source for the less pollutant industries. •Municipalities can decisively influence on industrial carbon footprint
International Nuclear Information System (INIS)
2001-12-01
The following study deals with the development of methodology for cost calculations and financial planning of decommissioning operations. It has been carried out by EDF / FRAMATOME / VUJE / SCK-CEN in the frame of the contract B7-032/2000/291058/MAR/C2 awarded by the European Commission. This study consists of 4 parts. The first task objective is to develop a reliable and transparent methodology for cost assessment and financial planning sufficient precise but without long and in depth investigations and studies. This methodology mainly contains: Calculation methods and algorithms for the elaboration of costs items making up the whole decommissioning cost. Estimated or standard values for the parameters and for the cost factors to be used in the above-mentioned algorithms Financial mechanism to be applied as to establish a financial planning. The second part task is the provision of standard values for the different parameters and costs factors described in the above-mentioned algorithms. This provision of data is based on the own various experience acquired by the members of the working team and on existing international references (databases, publications and reports). As decommissioning operations are spreading over several dozens of years, the scope of this task the description of the financial mechanisms to be applied to the different cost items as to establish a complete financial cost. It takes into account the financial schedule issued in task 1. The scope of this task consists in bringing together in a guideline all the information collected before: algorithms, data and financial mechanisms. (A.L.B.)
2011-03-09
... Trend Factor Methodology Used in the Calculation of Fair Market Rents AGENCY: Office of the Assistant... used to calculate the trend factor component of the Fair Market Rent estimates. SUMMARY: Section 8(c)(1... comment regarding the manner in which HUD calculates the trend factor used in the Fair Market Rent (FMR...
Improvement in decay ratio calculation in LAPUR5 methodology for BWR instability
International Nuclear Information System (INIS)
Li Hsuannien; Yang Tzungshiue; Shih Chunkuan; Wang Jongrong; Lin Haotzu
2009-01-01
LAPUR5, based on frequency domain approach, is a computer code that analyzes the core stability and calculates decay ratios (DRs) of boiling water nuclear reactors. In current methodology, one set of parameters (three friction multipliers and one density reactivity coefficient multiplier) is chosen for LAPUR5 input files, LAPURX and LAPURW. The calculation stops and DR for this particular set of parameters is obtained when the convergence criteria (pressure, mass flow rate) are first met. However, there are other sets of parameters which could also meet the same convergence criteria without being identified. In order to cover these ranges of parameters, we developed an improved procedure to calculate DR in LAPUR5. First, we define the ranges and increments of those dominant input parameters in the input files for DR loop search. After LAPUR5 program execution, we can obtain all DRs for every set of parameters which satisfy the converge criteria in one single operation. The part for loop search procedure covers those steps in preparing LAPURX and LAPURW input files. As a demonstration, we looked into the reload design of Kuosheng Unit 2 Cycle 22. We found that the global DR has a maximum at exposure of 9070 MWd/t and the regional DR has a maximum at exposure of 5770 MWd/t. It should be noted that the regional DR turns out to be larger than the global ones for exposures less than 5770 MWd/t. Furthermore, we see that either global or regional DR by the loop search method is greater than the corresponding values from our previous approach. It is concluded that the loop search method can reduce human error and save human labor as compared with the previous version of LAPUR5 methodology. Now the maximum DR can be effectively obtained for a given plant operating conditions and a more precise stability boundary, with less uncertainty, can be plotted on plant power/flow map. (author)
Methodology to Calculate the Costs of a Floating Offshore Renewable Energy Farm
Directory of Open Access Journals (Sweden)
Laura Castro-Santos
2016-04-01
Full Text Available This paper establishes a general methodology to calculate the life-cycle cost of floating offshore renewable energy devices, applying it to wave energy and wind energy devices. It is accounts for the contributions of the six main phases of their life-cycle: concept definition, design and development, manufacturing, installation, exploitation and dismantling, the costs of which have been defined. Moreover, the energy produced is also taken into account to calculate the Levelized Cost of Energy of a floating offshore renewable energy farm. The methodology proposed has been applied to two renewable energy devices: a floating offshore wave energy device and a floating offshore wind energy device. Two locations have been considered: Aguçadoura and São Pedro de Moel, both in Portugal. Results indicate that the most important cost in terms of the life-cycle of a floating offshore renewable energy farm is the exploitation cost, followed by the manufacturing and the installation cost. In addition, the best area in terms of costs is the same independently of the type of floating offshore renewable energy considered: Aguçadoura. However, the results in terms of Levelized Cost of Energy are different: Aguçadoura is better when considering wave energy technology and the São Pedro de Moel region is the best option when considering floating wind energy technology. The method proposed aims to give a direct approach to calculate the main life-cycle cost of a floating offshore renewable energy farm. It helps to assess its feasibility and evaluating the relevant characteristics that influence it the most.
Study of the methodology for sensitivity calculations of fast reactors integral parameters
International Nuclear Information System (INIS)
Renke, C.A.C.
1981-06-01
A study of the methodology for sensitivity calculations of integral parameters of fast reactors for the adjustment of multigroup cross sections is presented. A description of several existent methods and theories is given, with special emphasis being regarded to variational perturbation theory, integrant of the sensitivity code VARI-1D used in this work. Two calculational systems are defined and a set of procedures and criteria is structured gathering the necessary conditions for the determination of the sensitivity coefficients. These coefficients are then computed by both the direct method and the variational perturbation theory. A reasonable number of sensitivity coefficients are computed and analyzed for three fast critical assemblies, covering a range of special interest of the spectrum. These coefficients are determined for severa integral parameters, for the capture and fission cross sections of the U-238 and Pu-239, covering all the energy up to 14.5 MeV. The nuclear data used were obtained the CARNAVAL II calculational system of the Instituto de Engenharia Nuclear. An optimization for sensitivity computations in a chainned sequence of procedures is made, yielding the sensitivities in the energy macrogroups as the final stage. (Author) [pt
SYN3D: a single-channel, spatial flux synthesis code for diffusion theory calculations
Energy Technology Data Exchange (ETDEWEB)
Adams, C. H.
1976-07-01
This report is a user's manual for SYN3D, a computer code which uses single-channel, spatial flux synthesis to calculate approximate solutions to two- and three-dimensional, finite-difference, multigroup neutron diffusion theory equations. SYN3D is designed to run in conjunction with any one of several one- and two-dimensional, finite-difference codes (required to generate the synthesis expansion functions) currently being used in the fast reactor community. The report describes the theory and equations, the use of the code, and the implementation on the IBM 370/195 and CDC 7600 of the version of SYN3D available through the Argonne Code Center.
SYN3D: a single-channel, spatial flux synthesis code for diffusion theory calculations
International Nuclear Information System (INIS)
Adams, C.H.
1976-07-01
This report is a user's manual for SYN3D, a computer code which uses single-channel, spatial flux synthesis to calculate approximate solutions to two- and three-dimensional, finite-difference, multigroup neutron diffusion theory equations. SYN3D is designed to run in conjunction with any one of several one- and two-dimensional, finite-difference codes (required to generate the synthesis expansion functions) currently being used in the fast reactor community. The report describes the theory and equations, the use of the code, and the implementation on the IBM 370/195 and CDC 7600 of the version of SYN3D available through the Argonne Code Center
Directory of Open Access Journals (Sweden)
Gou Hosoya
2013-01-01
Full Text Available Approximate calculation of channel log-likelihood ratio (LLR for wireless channels using Padé approximation is presented. LLR is used as an input of iterative decoding for powerful error-correcting codes such as low-density parity-check (LDPC codes or turbo codes. Due to the lack of knowledge of the channel state information of a wireless fading channel, such as uncorrelated fiat Rayleigh fading channels, calculations of exact LLR for these channels are quite complicated for a practical implementation. The previous work, an LLR calculation using the Taylor approximation, quickly becomes inaccurate as the channel output leaves some derivative point. This becomes a big problem when higher order modulation scheme is employed. To overcome this problem, a new LLR approximation using Padé approximation, which expresses the original function by a rational form of two polynomials with the same total number of coefficients of the Taylor series and can accelerate the Taylor approximation, is devised. By applying the proposed approximation to the iterative decoding and the LDPC codes with some modulation schemes, we show the effectiveness of the proposed methods by simulation results and analysis based on the density evolution.
A Methodology Proposal to Calculate the Externalisation of Liquid Bio fuels
International Nuclear Information System (INIS)
Galan, A.; Gonzalez, R.; Varela, M.
1999-01-01
The aim of the survey is to propose a methodology to calculate the externalisation associated with the liquid bio fuels cycle. The report defines the externalisation from a theoretical point of view and classifies them. The reasons to value the externalisation are explained as well as the existing methods. Furthermore, an evaluation of specific environmental and non-environmental externalisation is also presented. The report also reviews the current situation of the transport sector, considering its environmental effects and impacts. The progress made by the ExtemE and ExternE-Transport projects related the externalisation of transport sector is assessed. Finally, the report analyses the existence of different economic instruments to internalize the external effects of the transport sector as well as other aspects of this internalization. (Author) 58 refs
Implementation and adaptation of a macro-scale methodology to calculate direct economic losses
Natho, Stephanie; Thieken, Annegret
2017-04-01
As one of the 195 member countries of the United Nations, Germany signed the Sendai Framework for Disaster Risk Reduction 2015-2030 (SFDRR). With this, though voluntary and non-binding, Germany agreed to report on achievements to reduce disaster impacts. Among other targets, the SFDRR aims at reducing direct economic losses in relation to the global gross domestic product by 2030 - but how to measure this without a standardized approach? The United Nations Office for Disaster Risk Reduction (UNISDR) has hence proposed a methodology to estimate direct economic losses per event and country on the basis of the number of damaged or destroyed items in different sectors. The method bases on experiences from developing countries. However, its applicability in industrial countries has not been investigated so far. Therefore, this study presents the first implementation of this approach in Germany to test its applicability for the costliest natural hazards and suggests adaptations. The approach proposed by UNISDR considers assets in the sectors agriculture, industry, commerce, housing, and infrastructure by considering roads, medical and educational facilities. The asset values are estimated on the basis of sector and event specific number of affected items, sector specific mean sizes per item, their standardized construction costs per square meter and a loss ratio of 25%. The methodology was tested for the three costliest natural hazard types in Germany, i.e. floods, storms and hail storms, considering 13 case studies on the federal or state scale between 1984 and 2016. Not any complete calculation of all sectors necessary to describe the total direct economic loss was possible due to incomplete documentation. Therefore, the method was tested sector-wise. Three new modules were developed to better adapt this methodology to German conditions covering private transport (cars), forestry and paved roads. Unpaved roads in contrast were integrated into the agricultural and
A Methodology Proposal to Calculate the Externalisation of Liquid Bio fuels
Energy Technology Data Exchange (ETDEWEB)
Galan, A.; Gonzalez, R.; Varela, M.
1999-07-01
The aim of the survey is to propose a methodology to calculate the externalisation associated with the liquid bio fuels cycle. The report defines the externalisation from a theoretical point of view and classifies them. The reasons to value the externalisation are explained as well as the existing methods. Furthermore, an evaluation of specific environmental and non-environmental externalisation is also presented. The report also reviews the current situation of the transport sector, considering its environmental effects and impacts. The progress made by the ExtemE and ExternE-Transport projects related the externalisation of transport sector is assessed. Finally, the report analyses the existence of different economic instruments to internalize the external effects of the transport sector as well as other aspects of this internalization. (Author) 58 refs.
Application of a methodological advance to calculate 3D flow fields in river channel junctions
Moradi, Gelare; Vermeulen, Bart; Rennie, Colin; Cardot, Romain; Lane, Stuart
2018-01-01
Acoustic Doppler current profiler (aDcp) vessel-mounted flow measurements are now commonly used to quantify discharge and velocity in shallow water fluvial environments. Here, we consider the benefits of improving secondary circulation estimates in river confluences through the manner in which
Benchmark evaluation of the RELAP code to calculate boiling in narrow channels
International Nuclear Information System (INIS)
Kunze, J.F.; Loyalka, S.K.; McKibben, J.C.; Hultsch, R.; Oladiran, O.
1990-01-01
The RELAP code has been tested with benchmark experiments (such as the loss-of-fluid test experiments at the Idaho National Engineering Laboratory) at high pressures and temperatures characteristic of those encountered in loss-of-coolant accidents (LOCAs) in commercial light water power reactors. Application of RELAP to the LOCA analysis of a low pressure (< 7 atm) and low temperature (< 100 degree C), plate-type research reactor, such as the University of Missouri Research Reactor (MURR), the high-flux breeder reactor, high-flux isotope reactor, and Advanced Test Reactor, requires resolution of questions involving overextrapolation to very low pressures and low temperatures, and calculations of the pulsed boiling/reflood conditions in the narrow rectangular cross-section channels (typically 2 mm thick) of the plate fuel elements. The practical concern of this problem is that plate fuel temperatures predicted by RELAP5 (MOD2, version 3) during the pulsed boiling period can reach high enough temperatures to cause plate (clad) weakening, though not melting. Since an experimental benchmark of RELAP under such LOCA conditions is not available and since such conditions present substantial challenges to the code, it is important to verify the code predictions. The comparison of the pulsed boiling experiments with the RELAP calculations involves both visual observations of void fraction versus time and measurements of temperatures near the fuel plate surface
SCALE6 Hybrid Deterministic-Stochastic Shielding Methodology for PWR Containment Calculations
International Nuclear Information System (INIS)
Matijevic, Mario; Pevec, Dubravko; Trontl, Kresimir
2014-01-01
CADIS and also analog MC simulations, the FW-CADIS drastically improved MC dose rate calculations in quality as well in quantity. Large shielding problems such as portions and complete PWR facility require not only extensive computational resources but also understanding of the underlying physics, which is inevitable in interpreting results of hybrid deterministic-stochastic methodology. (authors)
Directory of Open Access Journals (Sweden)
Mariya Vishnevskaya
2017-12-01
Full Text Available Two main components of the problem studied in the article are revealed. At the practical level, the provision of the convenient tools allowing a comprehensive evaluation the proposed innovative project in terms of its possibilities for inclusion in the portfolio or development program, and on the level of science – the need for improvement and complementing the existing methodology of assessment of innovative projects attractiveness in the context of their properties and a specific set of components. The research is scientifically applied since the problem solution involves the science-based development of a set of techniques, allowing the practical use of knowledge gained from large information arrays at the initialization stage. The purpose of the study is the formation of an integrated indicator of the project innovation, with a substantive justification of the calculation method, as a tool for the evaluation and selection of projects to be included in the portfolio of projects and programs. The theoretical and methodological basis of the research is the conceptual provisions and scientific developments of experts on project management issues, published in monographs, periodicals, materials of scientific and practical conferences on the topic of research. The tasks were solved using the general scientific and special methods, mathematical modelling methods based on the system approach. Results. A balanced system of parametric single indicators of innovation is presented – the risks, personnel, quality, innovation, resources, and performers, which allows getting a comprehensive idea of any project already in the initial stages. The choice of a risk tolerance as a key criterion of the “risks” element and the reference characteristics is substantiated, in relation to which it can be argued that the potential project holds promise. A tool for calculating the risk tolerance based on the use of matrices and vector analysis is proposed
Haqiqi, M. T.; Yuliansyah; Suwinarti, W.; Amirta, R.
2018-04-01
Short Rotation Coppice (SRC) system is an option to provide renewable and sustainable feedstock in generating electricity for rural area. Here in this study, we focussed on application of Response Surface Methodology (RSM) to simplify calculation protocols to point out wood chip production and energy potency from some tropical SRC species identified as Bauhinia purpurea, Bridelia tomentosa, Calliandra calothyrsus, Fagraea racemosa, Gliricidia sepium, Melastoma malabathricum, Piper aduncum, Vernonia amygdalina, Vernonia arborea and Vitex pinnata. The result showed that the highest calorific value was obtained from V. pinnata wood (19.97 MJ kg-1) due to its high lignin content (29.84 %, w/w). Our findings also indicated that the use of RSM for estimating energy-electricity of SRC wood had significant term regarding to the quadratic model (R2 = 0.953), whereas the solid-chip ratio prediction was accurate (R2 = 1.000). In the near future, the simple formula will be promising to calculate energy production easily from woody biomass, especially from SRC species.
Methodology for calculation of doses to man and implementation in Pandora
Energy Technology Data Exchange (ETDEWEB)
Avila, Rodolfo [Facilia AB, Bromma (Sweden); Bergstroem, Ulla [Swepro Project Management AB, Solna (Sweden)
2006-07-15
This report describes methods and data for calculation of doses to man to be used in safety assessments of repositories for nuclear fuel. The methods are based on the latest recommendations from the ICRP; the EU and the national radiation protection authorities. Equations are given for calculation of doses from ingestion of contaminated water and food, inhalation of contaminated air and external exposure from radionuclides in the ground. With the exception of the exposure from food ingestion, the equations are the same used in previous safety assessments. A general equation is suggested for estimation of the exposure from food ingestion, in which the annual demand of carbon is used instead of the annual ingestion of different food-stuffs, which was earlier applied. The report contains tables with recommended values for physiological characteristics such as water intake, food intake and inhalation rates, based on information summarised in an Appendix. Furthermore, tables are given with recommended age dependent dose conversion factors for ingestion and inhalation for a number of nuclides of interest for safety assessments. The most recently published dose conversion factors for external exposure from contaminated ground are also given. An overview of the implementation of the methodology in Pandora, which is the tool that SKB and Posiva currently use for biosphere modelling, is also provided. The work presented in the report is a result from a joint project commissioned by SKB and Posiva.
Methodology for calculation of doses to man and implementation in Pandora
International Nuclear Information System (INIS)
Avila, R.; Bergstroem, U.
2006-07-01
This report describes methods and data for calculation of doses to man to be used in safety assessments of repositories for nuclear fuel. The methods are based on the latest recommendations from the ICRP, the EU and the national radiation protection authorities. Equations are given for calculation of doses from ingestion of contaminated water and food, inhalation of contaminated air and external exposure from radionuclides in the ground. With the exception of the exposure from food ingestion, the equations are the same used in previous safety assessments. A general equation is suggested for estimation of the exposure from food ingestion, in which the annual demand of carbon is used instead of the annual ingestion of different foodstuffs, which was earlier applied. The report contains tables with recommended values for physiological characteristics such as water intake, food intake and inhalation rates, based on information summarised in an Appendix. Furthermore, tables are given with recommended age dependent dose conversion factors for ingestion and inhalation for a number of nuclides of interest for safety assessments. The most recently published dose conversion factors for external exposure from contaminated ground are also given. An overview of the implementation of the methodology in Pandora, which is the tool that Posiva and SKB currently use for biosphere modelling, is also provided. The work presented in the report is a result from a joint project commissioned by Svensk Kaernbraenslehantering AB (SKB) and Posiva. The report will be printed also as a SKB report R-06-68. (orig.)
Methodology for calculation of doses to man and implementation in Pandora
International Nuclear Information System (INIS)
Avila, Rodolfo; Bergstroem, Ulla
2006-07-01
This report describes methods and data for calculation of doses to man to be used in safety assessments of repositories for nuclear fuel. The methods are based on the latest recommendations from the ICRP; the EU and the national radiation protection authorities. Equations are given for calculation of doses from ingestion of contaminated water and food, inhalation of contaminated air and external exposure from radionuclides in the ground. With the exception of the exposure from food ingestion, the equations are the same used in previous safety assessments. A general equation is suggested for estimation of the exposure from food ingestion, in which the annual demand of carbon is used instead of the annual ingestion of different food-stuffs, which was earlier applied. The report contains tables with recommended values for physiological characteristics such as water intake, food intake and inhalation rates, based on information summarised in an Appendix. Furthermore, tables are given with recommended age dependent dose conversion factors for ingestion and inhalation for a number of nuclides of interest for safety assessments. The most recently published dose conversion factors for external exposure from contaminated ground are also given. An overview of the implementation of the methodology in Pandora, which is the tool that SKB and Posiva currently use for biosphere modelling, is also provided. The work presented in the report is a result from a joint project commissioned by SKB and Posiva
Energy Technology Data Exchange (ETDEWEB)
Sun, L., E-mail: LSun@nbpower.com [Point Lepreau Generating Station, Lepreau, NB, (Canada)
2015-07-01
During a postulated large LOCA event in CANDU reactors, the pressure tube may balloon to contact with its surrounding calandria tube to transfer heat to the moderator. To confirm the integrity of the fuel channel in this case, many experiments have been performed in the last three decades. Based on the extant database of the pressure tube/calandria tube (PT/CT) contact, an analytical methodology was developed by Canadian Nuclear Industry to determine the sufficiency of moderator subcooling for fuel channel integrity. At the same time a semi-empirical methodology with an idea of Equivalent Moderator Subcooling (EMS) was also developed to judge the sufficiency of the moderator. In this work, some discussions were made over the two methodologies on their conservatism and it is demonstrated that the analytical approach is over conservative comparing with the EMS methodology. By using the EMS methodology, it is demonstrated that applying glass-peened calandria tubes, the requirement to moderator subcooling can be reduced by 10{sup o}C from that for smooth calandria tubes. (author)
Methodology comparison for gamma-heating calculations in material-testing reactors
Energy Technology Data Exchange (ETDEWEB)
Lemaire, M.; Vaglio-Gaudard, C.; Lyoussi, A. [CEA, DEN, DER, Cadarache F-13108 Saint Paul les Durance (France); Reynard-Carette, C. [Aix Marseille Universite, CNRS, Universite de Toulon, IM2NP UMR 7334, 13397, Marseille (France)
2015-07-01
The Jules Horowitz Reactor (JHR) is a Material-Testing Reactor (MTR) under construction in the south of France at CEA Cadarache (French Alternative Energies and Atomic Energy Commission). It will typically host about 20 simultaneous irradiation experiments in the core and in the beryllium reflector. These experiments will help us better understand the complex phenomena occurring during the accelerated ageing of materials and the irradiation of nuclear fuels. Gamma heating, i.e. photon energy deposition, is mainly responsible for temperature rise in non-fuelled zones of nuclear reactors, including JHR internal structures and irradiation devices. As temperature is a key parameter for physical models describing the behavior of material, accurate control of temperature, and hence gamma heating, is required in irradiation devices and samples in order to perform an advanced suitable analysis of future experimental results. From a broader point of view, JHR global attractiveness as a MTR depends on its ability to monitor experimental parameters with high accuracy, including gamma heating. Strict control of temperature levels is also necessary in terms of safety. As JHR structures are warmed up by gamma heating, they must be appropriately cooled down to prevent creep deformation or melting. Cooling-power sizing is based on calculated levels of gamma heating in the JHR. Due to these safety concerns, accurate calculation of gamma heating with well-controlled bias and associated uncertainty as low as possible is all the more important. There are two main kinds of calculation bias: bias coming from nuclear data on the one hand and bias coming from physical approximations assumed by computer codes and by general calculation route on the other hand. The former must be determined by comparison between calculation and experimental data; the latter by calculation comparisons between codes and between methodologies. In this presentation, we focus on this latter kind of bias. Nuclear
Krafft, M.; Goetz, O.; Mantrala, M.; Sotgiu, F.; Tillmanns, S.
2015-01-01
Marketing channels are among the most important elements of any value chain. This is because the bulk of a nation's manufacturing output flows through them. The intermediaries (e.g., distributors, wholesalers, retailers) constituting marketing channels perform specific distribution functions, such
International Nuclear Information System (INIS)
Rupani, B.B.; Sinha, S.K.; Sinha, R.K.
2002-01-01
Zirconium alloy coolant channels are central to the design of Indian Pressurised Heavy Water Reactors (PHWRs) and form the individual pressure boundaries. These coolant channels consist of horizontal pressure tubes made of zirconium alloys, which are separated from cold calandria tubes using garter spring spacers. High temperature heavy water coolant flows through the pressure tube which supports the fuel bundles. A typical coolant channel in a PHWR is shown. These pressure tubes are subjected to several life limiting degradation mechanisms like creep and growth, hydrogen pick-up, reduction in fracture toughness and delayed hydride cracking phenomena because of their operation under high temperature, high stress and high fast neutron flux environment. Considering the early onset of these degradation mechanisms in Zircaloy-2 pressure tubes used in the early generation of Indian PHWRs, the life management of these coolant channels becomes a challenging task, involving multidisciplinary R and D efforts in areas like analytical modelling of degradation mechanisms, evolution of methodologies for assessment of fitness for service and, tools and techniques for remote on line monitoring of integrity, maintenance and replacement. The degradation mechanisms have been modelled and incorporated into specially developed computer codes, such as SCAPCA for irradiation induced creep and growth deformation modelling, HYCON for hydrogen pick-up modelling, BLIST for hydrogen diffusion, blister nucleation and growth modelling and CEAL for assessment of leak before break behaviour. These codes have been validated with respect to the results of in-service inspection and post irradiation examination. Development of analytical models actually paved the way for the evolution of more refined methodologies for assessing the safe residual life of coolant channel. Information gathered from various experiments simulating the degradation mechanisms, results of post-irradiation examination of the
Thermohydraulic calculations in rectangular channels for RA-6 type reactors with transition regime
International Nuclear Information System (INIS)
Sillin, N; Vertullo, A.; Masson, V.; Hilal, R
2009-01-01
In August 2000 and within the framework of the RA-6 core conversion from high to low enrichment (20%), a preliminary analysis was performed to evaluate the maximum power that the reactor could operate with the new kernel without makeing substantial changes. This meant keeping intact, for example, the concrete shield of the pool and the nucleus inlet and outlet pipes embedded in the walls. Preliminary results indicated that for these boundary conditions a maximum power of about 3 MWt could be achieved. In August 2005 the project was resumed and new calculations performed taking as a starting point the ECBE plate fuel element(U3O8-Al). A core was developed with cooling channle widths of 2.6 mm for the control fuel elements and 2.7 mm for standard fuel elements. The thermo-hydraulic calculation puts in evidence that coolant flow into the core was in the transitional regime for the vast majority of configurations. While TERMIC code, used for thermo-hydraulic design, has been extensively tested and validated for use in research reactors under turbulent and laminar flows, this is not so for transition conditions. The transition regime is strongly dependent on conditions such as flow inlet characteristics, channel geometry, etc.. and therefore there are no reliable correlations for general use. For this reason we found it convenient to carry out experiments simulating the working conditions in order to adjust the code results with experimental data. In the present work we show the experimental results, the simulation of the experiences using the TERMIC code, and the adjustments made to the correlations used by the code so that it can be applied to the thermo-hydraulic design of the new core. [es
Calculation of channels for forming and transport of medical proton beams at the JINR phasotron
International Nuclear Information System (INIS)
Kuz'min, E.S.; Mirokhin, I.V.; Molokanov, A.G.; Obukhov, Yu.L.; Savchenko, O.V.
1984-01-01
Results of numerical simulation of shaping and transporting processes of therapeutic proton beams with a modified Bragg curve at the JINR phasotron are presented. The mean energy of proton beams are about 100, 130 and 200 MeV. To provide the flat-topped depth-dose distributions with a steep back slope, the method of shaping with a necessary energy spectrum from a nonmonoenergetic beam is used. It is shown by the calculations that it is possible to choose such modes of the channel operation at which clinical-physical requirements to the parameters of medical proton beams are satisfied. Extensions of flat-tops of dose peaks are 1.3 g/cm 2 , 1.7 g/cm 2 and 3.5 g/cm 2 for the 100 MeV, 130 MeV and 200 MeV beam energies, respectively. Dose rate in the peaks of modified distributions are not less than 100 rad per minute
Polarization and sidewall effects in a coal fired MHD channel - three-dimensional calculation
International Nuclear Information System (INIS)
Ishikawa, M.; Scott, M.H.; Wu, Y.C.L.
1981-01-01
The effects of slag polarization of electrodes and the sidewall configuration on generator performance are studied experimentally and analytically. An analysis of the voltage-current characteristics between two generator frames measured during the operation of the TP40-07 experiment is given, along with an examination of nonuniformities of interframe voltage. Experimental data show that the polarization effect reduces about 3% of the overall electrical performance of the 60 deg diagonal conducting channel used in the study. Analytically, the effect of polarization on the local current and potential distributions is examined by solving the three-dimensional electrical potential using a finite element method. A moderate increase in conductivity in the vicinity of the cathode-side frame is found to give a calculated leakage resistance which approximates the value derived experimentally. The polarization effect results in a large change in the potential and current distributions near the frame but has a small effect on the overall electrical performance. Alternate sidewall/electrode configurations are treated analytically
Feng, Lei; Zhang, Yugui
2017-08-01
Dispersion analysis is an important part of in-seam seismic data processing, and the calculation accuracy of the dispersion curve directly influences pickup errors of channel wave travel time. To extract an accurate channel wave dispersion curve from in-seam seismic two-component signals, we proposed a time-frequency analysis method based on single-trace signal processing; in addition, we formulated a dispersion calculation equation, based on S-transform, with a freely adjusted filter window width. To unify the azimuth of seismic wave propagation received by a two-component geophone, the original in-seam seismic data undergoes coordinate rotation. The rotation angle can be calculated based on P-wave characteristics, with high energy in the wave propagation direction and weak energy in the vertical direction. With this angle acquisition, a two-component signal can be converted to horizontal and vertical directions. Because Love channel waves have a particle vibration track perpendicular to the wave propagation direction, the signal in the horizontal and vertical directions is mainly Love channel waves. More accurate dispersion characters of Love channel waves can be extracted after the coordinate rotation of two-component signals.
International Nuclear Information System (INIS)
Fetter, S.
1985-01-01
A methodology has been developed for calculating indices of three classes of radiological hazards: reactor accidents, occupational exposures, and waste-disposal hazards. Radionuclide inventories, biological hazard potentials (BHP), and various dose-related indices are calculated. In the case of reactor accidents, the critical, 50-year and chronic dose are computed, as well as the number of early deaths and illnesses and late cancer fatalities. For occupational exposure, the contact dose rate is calculated for several times after reactor shutdown. In the case of waste-disposal hazards, the intruder dose and the intruder hazard potential (IHP) are calculated. Sample calculations for the MARS reactor design show the usefulness of the methodology in exploring design improvements
International Nuclear Information System (INIS)
Gomes, Renato G.; Rebello, Wilson F.; Vellozo, Sergio O.; Moreira Junior, Luis; Vital, Helio C.; Rusin, Tiago; Silva, Ademir X.
2013-01-01
In order to evaluate new lines of research in the area of irradiation of materials external to the research irradiating facility Army Technology Center (CTEx), it is necessary to study security parameters and magnitude of the dose rates from their channels of escape. The objective was to calculate, with the code MCNPX, dose rates (Gy / min) on the interior and exterior of the four-channel leakage gamma irradiator. The channels were designed to leak radiation on materials properly disposed in the area outside the irradiator larger than the expected volume of irradiation chambers (50 liters). This study aims to assess the magnitude of dose rates within the channels, as well as calculate the angle of beam output range outside the channel for analysis as to its spread, and evaluation of safe conditions of their operators (protection radiological). The computer simulation was performed by distributing virtual dosimeter ferrous sulfate (Fricke) in the longitudinal axis of the vertical drain channels (anterior and posterior) and horizontal (top and bottom). The results showed a collimating the beams irradiated on each of the channels to the outside, with values of the order of tenths of Gy / min as compared to the maximum amount of operation of the irradiator chamber (33 Gy / min). The external beam irradiation in two vertical channels showed a distribution shaped 'trunk pyramid', not collimated, so scattered, opening angle 83 ° in the longitudinal direction and 88 in the transverse direction. Thus, the cases allowed the evaluation of materials for irradiation outside the radiator in terms of the magnitude of the dose rates and positioning of materials, and still be able to take the necessary care in mounting shield for radiation protection by operators, avoiding exposure to ionizing radiation. (author)
Calculation of nonsteady heat transfer in channels at the second-type boundary conditions
International Nuclear Information System (INIS)
Ryadno, A.A.
1982-01-01
The algorithm of solving non-stationary edge problems of convective heat exchange realized for the luminary longtitudinal flow-around with non-compressed liquid of a bundle of cores, is developed. The method can be used for solving problems of non-stationary heat exchange in channels with any form of transverse cross section, as well as in the case of turbulent regime of liquid flow (if the rate profile and the distribution of turbulent temperature conductivity in the cross section of the channel are known). The method permits to solVe problems with variable density of the thermal flux (at the internal channel surface)
Energy Technology Data Exchange (ETDEWEB)
NONE
2000-05-01
Knowing the quantities of certain substances discharged into the atmosphere is a necessary and fundamental stage in any environmental protection policy to tackle today's problems such as acid rain, the degradation of air quality, global warming and climate change, the depletion of the ozone layer, etc. This quantification, usually known as an 'emission inventory', is built on a set of specific rules which may vary from one inventory to another. This state of affairs presents the enormous disadvantage that the data available are not comparable. At the international level, an attempt at harmonization has been going on for some years between the various international bodies. This work is being pursued in parallel with the improvement of methodologies to estimate discharges from various types of source. To take account of changes in specifications and of improvements in our understanding of phenomena giving rise to atmospheric pollution, the results of inventories of emissions need to be regularly revised, even retrospectively, to maintain a consistent series. CITEPA, which acts as a National Reference Centre, has developed a system of inventories as part of the CORALIE programme with financial help from the French Ministry for Planning and the Environment. (author)
Energy Technology Data Exchange (ETDEWEB)
NONE
2000-05-01
Knowing the quantities of certain substances discharged into the atmosphere is a necessary and fundamental stage in any environmental protection policy to tackle today's problems such as acid rain, the degradation of air quality, global warming and climate change, the depletion of the ozone layer, etc. This quantification, usually known as an 'emission inventory', is built on a set of specific rules which may vary from one inventory to another. This state of affairs presents the enormous disadvantage that the data available are not comparable. At the international level, an attempt at harmonization has been going on for some years between the various international bodies. This work is being pursued in parallel with the improvement of methodologies to estimate discharges from various types of source. To take account of changes in specifications and of improvements in our understanding of phenomena giving rise to atmospheric pollution, the results of inventories of emissions need to be regularly revised, even retrospectively, to maintain a consistent series. CITEPA, which acts as a National Reference Centre, has developed a system of inventories as part of the CORALIE programme with financial help from the French Ministry for Planning and the Environment. (author)
Use of the Le Chatelier principle in calculating the uniform flux in channels formed by packed rods
International Nuclear Information System (INIS)
Skrebkov, G.P.; Lozhkin, S.N.
1986-01-01
A method is proposed for calculating the hydrodynamics of a uniform flow in channels with a cross section of complex form. The method takes into account the anisotropy of the momentum transfer. The anisotropy coefficient of the momentum transfer is determined by using the Le Chatelier principle in a virtual process of transition to the kinematic structure of a uniform flux in equilibrium with a specified set of external conditions which include the channel geometry, wall roughness, and the value of the piezometric gradient
International Nuclear Information System (INIS)
El Bounagui, O.; Erramli, H.
2010-01-01
In this work, we report on calculations of the electronic channelling energy loss of hydrogen and helium ions along Si and Si axial directions for the low energy range by using the Monte Carlo simulation code. Simulated and experimental data are compared for protons and He ions in the and axis of silicon. A reasonable agreement was found. Computer simulation was also employed to study the angular dependence of energy loss for 0.5, 0.8, 1, and 2 MeV channelled 4 He ions transmitted through a silicon crystal of 3 μm thickness along the axis.
Azadegan, B.
2013-03-01
The presented Mathematica code is an efficient tool for simulation of planar channeling radiation spectra of relativistic electrons channeled along major crystallographic planes of a diamond-structure single crystal. The program is based on the quantum theory of channeling radiation which has been successfully applied to study planar channeling at electron energies between 10 and 100 MeV. Continuum potentials for different planes of diamond, silicon and germanium single crystals are calculated using the Doyle-Turner approximation to the atomic scattering factor and taking thermal vibrations of the crystal atoms into account. Numerical methods are applied to solve the one-dimensional Schrödinger equation. The code is designed to calculate the electron wave functions, transverse electron states in the planar continuum potential, transition energies, line widths of channeling radiation and depth dependencies of the population of quantum states. Finally the spectral distribution of spontaneously emitted channeling radiation is obtained. The simulation of radiation spectra considerably facilitates the interpretation of experimental data. Catalog identifier: AEOH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOH_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 446 No. of bytes in distributed program, including test data, etc.: 209805 Distribution format: tar.gz Programming language: Mathematica. Computer: Platforms on which Mathematica is available. Operating system: Operating systems on which Mathematica is available. RAM: 1 MB Classification: 7.10. Nature of problem: Planar channeling radiation is emitted by relativistic charged particles during traversing a single crystal in direction parallel to a crystallographic plane. Channeling is modeled as the motion
2011-06-13
... requirement. The Department plans to promulgate regulations about this methodology in the near future. In the...--Methodology for Calculating ``on'' or ``off'' Total Unemployment Rate Indicators for Purposes of Determining..., Labor. ACTION: Notice. SUMMARY: UIPL 16-11 informs states of the methodology used to calculate the ``on...
Calculating tracer currents through narrow ion channels: Beyond the independent particle model.
Coalson, Rob D; Jasnow, David
2018-06-01
Discrete state models of single-file ion permeation through a narrow ion channel pore are employed to analyze the ratio of forward to backward tracer current. Conditions under which the well-known Ussing formula for this ratio hold are explored in systems where ions do not move independently through the channel. Building detailed balance into the rate constants for the model in such a way that under equilibrium conditions (equal rate of forward vs. backward permeation events) the Nernst Equation is satisfied, it is found that in a model where only one ion can occupy the channel at a time, the Ussing formula is always obeyed for any number of binding sites, reservoir concentrations of the ions and electric potential difference across the membrane which the ion channel spans, independent of the internal details of the permeation pathway. However, numerical analysis demonstrates that when multiple ions can occupy the channel at once, the nonequilibrium forward/backward tracer flux ratio deviates from the prediction of the Ussing model. Assuming an appropriate effective potential experienced by ions in the channel, we provide explicit formulae for the rate constants in these models. © 2018 IOP Publishing Ltd.
THE METHODOLOGY FOR CALCULATING OF LABOR COSTS OF MEDICAL PERSONNEL IN MARKET CONDITIONS
Directory of Open Access Journals (Sweden)
S. V. Katasonov
2015-01-01
Full Text Available The article presents the approximate calculations of working time of physician to work with the patient and documentation. On the base of these calculations they outline the possible ways to optimize the work of the medical staff.
Directory of Open Access Journals (Sweden)
Raiker Witter
2015-01-01
Full Text Available Polarization of atoms plays a substantial role in molecular interactions. Class I and II force fields mostly calculate with fixed atomic charges which can cause inadequate descriptions for highly charged molecules, for example, ion channels or metalloproteins. Changes in charge distributions can be included into molecular mechanics calculations by various methods. Here, we present a very fast computational quantum mechanical method, the Bond Polarization Theory (BPT. Atomic charges are obtained via a charge calculation method that depend on the 3D structure of the system in a similar way as atomic charges of ab initio calculations. Different methods of population analysis and charge calculation methods and their dependence on the basis set were investigated. A refined parameterization yielded excellent correlation of R=0.9967. The method was implemented in the force field COSMOS-NMR and applied to the histidine-tryptophan-complex of the transmembrane domain of the M2 protein channel of influenza A virus. Our calculations show that moderate changes of side chain torsion angle χ1 and small variations of χ2 of Trp-41 are necessary to switch from the inactivated into the activated state; and a rough two-side jump model of His-37 is supported for proton gating in accordance with a flipping mechanism.
Energy Technology Data Exchange (ETDEWEB)
Korsah, K.; Turner, G.W.; Mullens, J.A. [Oak Ridge National Lab., TN (United States)
1995-04-01
A microprocessor-based reactor trip channel has been assembled for environmental testing under an Instrumentation and Control (I&C) Qualification Program sponsored by the US Nuclear Regulatory Commission. The goal of this program is to establish the technical basis and acceptance criteria for the qualification of advanced I&C systems. The trip channel implemented for this study employs technologies and digital subsystems representative of those proposed for use in some advanced light-water reactors (ALWRs) such as the Simplified Boiling Water Reactor (SBWR). It is expected that these tests will reveal any potential system vulnerabilities for technologies representative of those proposed for use in ALWRs. The experimental channel will be purposely stressed considerably beyond what it is likely to experience in a normal nuclear power plant environment, so that the tests can uncover the worst-case failure modes (i.e., failures that are likely to prevent an entire trip system from performing its safety function when required to do so). Based on information obtained from this study, it may be possible to recommend tests that are likely to indicate the presence of such failure mechanisms. Such recommendations would be helpful in augmenting current qualification guidelines.
International Nuclear Information System (INIS)
Korsah, K.; Turner, G.W.; Mullens, J.A.
1995-01-01
A microprocessor-based reactor trip channel has been assembled for environmental testing under an Instrumentation and Control (I ampersand C) Qualification Program sponsored by the U.S. Nuclear Regulatory Commission. The goal of this program is to establish the technical basis for the qualification of advanced I ampersand C systems. The trip channel implemented for this study employs technologies and digital subsystems representative of those proposed for use in some advanced light-water reactors (ALNWS) such as the Simplified Boiling Water Reactor (SBNW) and AP600. It is expected that these tests will reveal any potential system vulnerabilities for technologies representative of those proposed for use in ALNWS. The experimental channel will be purposely stressed considerably beyond what it is likely to experience in a normal nuclear power plant environment, so that the tests can uncover the worst-case failure modes (i.e., failures that are likely to prevent an entire trip system from performing its safety function when required to do so). Based on information obtained from this study, it may be possible to recommend tests that are likely to indicate the presence of such failure mechanisms. Such recommendations would be helpful in augmenting current qualification guidelines
Study on calculation model of onset of nucleate boiling in narrow channels
International Nuclear Information System (INIS)
Zhang Ming; Zhou Tao; Sheng Cheng; Fu Tao; Xiao Zejun
2011-01-01
In the reactor engineering, narrow channels was used widely for its high power density, exceptional heat transfer and actual engineering requirements. The point of Onset of Nucleate Boiling (ONB) is the key point of boiling heat transfer in narrow channels. The point of ONB can directly influence the following flow and heat transfer characteristics in the reactor. Due to the special structure and complexity flow, the point of ONB in narrow channels are effected by many factors, which characteristics are not understood completely yet. Using B and R model, Su Shun-yu model, Pan Liang-ming model and Yang Rui-chang model, the heat flux of onset of nucleate boiling is compared and analyzed by taking water as the medium . And then the relationships of the heat flux with pressure, mass flow and wall temperature are obtained. Based on the differences of each model, the mechanisms for the main influence factors are suggested. (authors)
Low-Rynolds number k-ε turbulence model for calculation of fast-reactor-channel flows
International Nuclear Information System (INIS)
Mikhin, V.I.
2000-01-01
For calculating the turbulent flows in the complex geometry channels typical for the nuclear reactor installation elements the low-Reynolds-number k-ε turbulence model with the model functions not containing the spatial coordinate like y + is proposed. Such spatial coordinate is usually used for modeling the turbulence near the wall correctly. The model completed on the developed flow of the non-viscous incompressible liquid in the plane channel correctly describes the transition from the laminar regime to the turbulent one. The calculated skin friction coefficients obey the well-known Dean and Zarbi - Reynolds laws. The mean velocity distributions are close to that obtained from the empirical three-layer Karman model. (author)
Energy Technology Data Exchange (ETDEWEB)
Villescas, G.; Corchon, F.
2013-07-01
he neutron fluence plays an important role in the study of the structural integrity of the reactor vessel after a certain time of neutron irradiation. The NRC defined in the Regulatory Guide 1.190, the way must be estimated neutron fluence, including uncertainty analysis of the validation process (creep uncertainty is ? 20%). TRANSWARE Enterprises Inc. developed a methodology for calculating the neutron flux, 1,190 based guide, known as RAMA. Uncertainty values obtained with this methodology, for about 18 vessels, are less than 10%.
International Nuclear Information System (INIS)
Medrano Asensio, Gregorio.
1976-06-01
A detailed power distribution calculation in a large power reactor requires the solution of the multigroup 3D diffusion equations. Using the finite difference method, this computation is too expensive to be performed for design purposes. This work is devoted to the single channel continous synthesis method: the choice of the trial functions and the determination of the mixing functions are discussed in details; 2D and 3D results are presented. The method is applied to the calculation of the IAEA ''Benchmark'' reactor and the results obtained are compared with a finite element resolution and with published results [fr
Developments in Sensitivity Methodologies and the Validation of Reactor Physics Calculations
Directory of Open Access Journals (Sweden)
Giuseppe Palmiotti
2012-01-01
Full Text Available The sensitivity methodologies have been a remarkable story when adopted in the reactor physics field. Sensitivity coefficients can be used for different objectives like uncertainty estimates, design optimization, determination of target accuracy requirements, adjustment of input parameters, and evaluations of the representativity of an experiment with respect to a reference design configuration. A review of the methods used is provided, and several examples illustrate the success of the methodology in reactor physics. A new application as the improvement of nuclear basic parameters using integral experiments is also described.
30 CFR 206.173 - How do I calculate the alternative methodology for dual accounting?
2010-07-01
... measured at facility measurement points whose quality exceeds 1,000 Btu/cf are subject to dual accounting... for dual accounting? 206.173 Section 206.173 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... the alternative methodology for dual accounting? (a) Electing a dual accounting method. (1) If you are...
The Reduction of Modal Sensor Channels through a Pareto Chart Methodology
Directory of Open Access Journals (Sweden)
Kaci J. Lemler
2015-01-01
Full Text Available Presented herein is a new experimental sensor placement procedure developed to assist in placing sensors in key locations in an efficient method to reduce the number of channels for a full modal analysis. It is a fast, noncontact method that uses a laser vibrometer to gather a candidate set of sensor locations. These locations are then evaluated using a Pareto chart to obtain a reduced set of sensor locations that still captures the motion of the structure. The Pareto chart is employed to identify the points on a structure that have the largest reaction to an input excitation and thus reduce the number of channels while capturing the most significant data. This method enhances the correct and efficient placement of sensors which is crucial in modal testing. Previously this required the development and/or use of a complicated model or set of equations. This new technique is applied in a case study on a small unmanned aerial system. The test procedure is presented and the results are discussed.
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyoung Tae; Park, Joo Hwan; Rhee, Bo Wook
2006-07-15
To justify the use of a commercial Computational Fluid Dynamics (CFD) code for a CANDU fuel channel analysis, especially for the radiation heat transfer dominant conditions, the CFX-10 code is tested against three benchmark problems which were used for the validation of a radiation heat transfer in the CANDU analysis code, a CATHENA. These three benchmark problems are representative of the CANDU fuel channel configurations from a simple geometry to whole fuel channel geometry. With assumptions of a non-participating medium completely enclosed with the diffuse, gray and opaque surfaces, the solutions of the benchmark problems are obtained by the concept of surface resistance to radiation accounting for the view factors and the emissivities. The view factors are calculated by the program MATRIX version 1.0 avoiding the difficulty of hand calculation for the complex geometries. For the solutions of the benchmark problems, the temperature or the net radiation heat flux boundary conditions are prescribed for each radiating surface to determine the radiation heat transfer rate or the surface temperature, respectively by using the network method. The Discrete Transfer Model (DTM) is used for the CFX-10 radiation model and its calculation results are compared with the solutions of the benchmark problems. The CFX-10 results for the three benchmark problems are in close agreement with these solutions, so it is concluded that the CFX-10 with a DTM radiation model can be applied to the CANDU fuel channel analysis where a surface radiation heat transfer is a dominant mode of the heat transfer.
International Nuclear Information System (INIS)
Kim, Hyoung Tae; Park, Joo Hwan; Rhee, Bo Wook
2006-07-01
To justify the use of a commercial Computational Fluid Dynamics (CFD) code for a CANDU fuel channel analysis, especially for the radiation heat transfer dominant conditions, the CFX-10 code is tested against three benchmark problems which were used for the validation of a radiation heat transfer in the CANDU analysis code, a CATHENA. These three benchmark problems are representative of the CANDU fuel channel configurations from a simple geometry to whole fuel channel geometry. With assumptions of a non-participating medium completely enclosed with the diffuse, gray and opaque surfaces, the solutions of the benchmark problems are obtained by the concept of surface resistance to radiation accounting for the view factors and the emissivities. The view factors are calculated by the program MATRIX version 1.0 avoiding the difficulty of hand calculation for the complex geometries. For the solutions of the benchmark problems, the temperature or the net radiation heat flux boundary conditions are prescribed for each radiating surface to determine the radiation heat transfer rate or the surface temperature, respectively by using the network method. The Discrete Transfer Model (DTM) is used for the CFX-10 radiation model and its calculation results are compared with the solutions of the benchmark problems. The CFX-10 results for the three benchmark problems are in close agreement with these solutions, so it is concluded that the CFX-10 with a DTM radiation model can be applied to the CANDU fuel channel analysis where a surface radiation heat transfer is a dominant mode of the heat transfer
International Nuclear Information System (INIS)
Jachic, J.
1985-01-01
It is presented the ONEDM neutronic simulator for RZ spatial calculation, two energy groups, aiming at researching and optimization of a low power fast reactor design. The simulator's methodology is based in RZ calculation from radial and axial calculation iteractively coupled and in macroscopic cross sections corrected by power density and asymmetry of the spectrum in the feedback process with phase library for reference neutronic state. The transversal area which are determined by energy groups and material region in the iteration are introduced in the spatial calculation. The simulator efficiency is tested and compared with the CITATION and 2DB codes. The cross sections are generated by 1DX code. (M.C.K.) [pt
Calculation methodology of the thermal margin in the CAREM 25 reactor
International Nuclear Information System (INIS)
Mazufri, Claudio M.
1995-01-01
According to the nuclear reactors characteristics, can be found different methodologies to appraise the thermal margin available in the core. In the particular case of the CAREM (25 MWe) reactor, where the core is cooled by low mass flux and there are zones with positive steam quality, such evaluation is critical. Due to these characteristics, it was necessary to develop one proper methodology. In the present work, the different steps of that development are described: the election of figures of merit for measure the thermal margin, the hypothesis to use, the election of the critical heat flux prediction model, model qualification and the specification of the core wide procedure. In each step assume criteria are discussed. (author). 9 refs, 1 tab, 1 fig
Puiatti, Marcelo; Vera, D Mariano A; Pierini, Adriana B
2009-10-28
Recently, we have proposed an approach for finding the valence anion ground state, based on the stabilization exerted by a polar solvent; the methodology used standard DFT methods and relatively inexpensive basis sets and yielded correct electron affinity (EA) values by gradually decreasing the dielectric constant of the medium. In order to address the overall performance of the new methodology, to find the best conditions for stabilizing the valence state and to evaluate its scope and limitations, we gathered a pool of 60 molecules, 25 of them bearing the conventional valence state as the ground anion and 35 for which the lowest anion state found holds the extra electron in a diffuse orbital around the molecule (non valence state). The results obtained by testing this representative set suggest a very good performance for most species having an experimental EA less negative than -3.0 eV; the correlation at the B3LYP/6-311+G(2df,p) level being y = 1.01x + 0.06, with a correlation index of 0.985. As an alternative, the time dependent DFT (TD-DFT) approach was also tested with both B3LYP and PBE0 functionals. The methodology we proposed shows a comparable or better accuracy with respect to TD-DFT, although the TD-DFT approach with the PBE0 functional is suggested as a suitable estimate for species with the most negative EAs (ca.-2.5 to -3.5 eV), for which stabilization strategies can hardly reach the valence state. As an application, a pool of 8 compounds of key biological interest with EAs which remain unknown or unclear were predicted using the new methodology.
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
Posuvailo, V. M.; Klapkiv, M. D.; Student, M. M.; Sirak, Y. Y.; Pokhmurska, H. V.
2017-03-01
The oxide ceramic coating with copper inclusions was synthesized by the method of plasma electrolytic oxidation (PEO). Calculations of the Gibbs energies of reactions between the plasma channel elements with inclusions of copper and copper oxide were carried out. Two methods of forming the oxide-ceramic coatings on aluminum base in electrolytic plasma with copper inclusions were established. The first method - consist in the introduction of copper into the aluminum matrix, the second - copper oxide. During the synthesis of oxide ceramic coatings plasma channel does not react with copper and copper oxide-ceramic included in the coating. In the second case is reduction of copper oxide in interaction with elements of the plasma channel. The content of oxide-ceramic layer was investigated by X-ray and X-ray microelement analysis. The inclusions of copper, CuAl2, Cu9Al4 in the oxide-ceramic coatings were found. It was established that in the spark plasma channels alongside with the oxidation reaction occurs also the reaction aluminothermic reduction of the metal that allows us to dope the oxide-ceramic coating by metal the isobaric-isothermal potential oxidation of which is less negative than the potential of the aluminum oxide.
ON IMPROVEMENT OF METHODOLOGY FOR CALCULATING THE INDICATOR «AVERAGE WAGE»
Directory of Open Access Journals (Sweden)
Oksana V. Kuchmaeva
2015-01-01
Full Text Available The article describes the approaches to the calculation of the indicator of average wages in Russia with the use of several sources of information. The proposed method is based on data collected by Rosstat and the Pension Fund of the Russian Federation. The proposed approach allows capturing data on the wages of almost all groups of employees. Results of experimental calculations on the developed technique are present in this article.
Calculation of t8/5 by response surface methodology for electric arc welding applications
Directory of Open Access Journals (Sweden)
Meseguer-Valdenebro José Luis
2014-01-01
Full Text Available One of the greatest difficulties traditionally found in stainless steel constructions has been the execution of welding parts in them. At the present time, the available technology allows us to use arc welding processes for that application without any disadvantage. Response surface methodology is used to optimise a process in which the variables that take part in it are not related to each other by a mathematical law. Therefore, an empiric model must be formulated. With this methodology the optimisation of one selected variable may be done. In this work, the cooling time that takes place from 800 to 500ºC, t8/5, after TIG welding operation, is modelled by the response surface method. The arc power, the welding velocity and the thermal efficiency factor are considered as the variables that have influence on the t8/5 value. Different cooling times,t8/5, for different combinations of values for the variables are previously determined by a numerical method. The input values for the variables have been experimentally established. The results indicate that response surface methodology may be considered as a valid technique for these purposes.
International Nuclear Information System (INIS)
Jacimovic, R.; Maucec, M.; Trkov, A.
2002-01-01
In this work experimental verification of Monte Carlo neutron flux calculations in the carousel facility (CF) of the 250 kW TRIGA Mark II reactor at the Jozef Stefan Institute is presented. Simulations were carried out using the Monte Carlo radiation-transport code, MCNP4B. The objective of the work was to model and verify experimentally the azimuthal variation of neutron flux in the CF for core No. 176, set up in April 2002. '1'9'8Au activities of Al-Au(0.1%) disks irradiated in 11 channels of the CF covering 180'0 around the perimeter of the core were measured. The comparison between MCNP calculation and measurement shows relatively good agreement and demonstrates the overall accuracy with which the detailed spectral characteristics can be predicted by calculations.(author)
On the calculation of the minimax-converse of the channel coding problem
Elkayam, Nir; Feder, Meir
2015-01-01
A minimax-converse has been suggested for the general channel coding problem by Polyanskiy etal. This converse comes in two flavors. The first flavor is generally used for the analysis of the coding problem with non-vanishing error probability and provides an upper bound on the rate given the error probability. The second flavor fixes the rate and provides a lower bound on the error probability. Both converses are given as a min-max optimization problem of an appropriate binary hypothesis tes...
METHODOLOGY FOR CALCULATION OF HORIZONTAL WATER PERMEABILITY COEFFICIENT IN SOIL CAPILLARY BORDER
Directory of Open Access Journals (Sweden)
E. I. Michnevich
2011-01-01
Full Text Available The paper shows that for overall estimation of soil water permeability it is necessary to know a horizontal water permeability value of a soil capillary border in addition to coefficients of filtration and permeability. Relations allowing to determine soil permeability in the area of incomplete saturation, are given in the paper. For a fully developed capillary border some calculation formulae have been obtained in the form of algebraic polynomial versus soil grading (grain composition. These formulae allow to make more accurate calculations while designing and operating reclamation works.
International Nuclear Information System (INIS)
Botto, D.; Zucca, S.; Gola, M.M.
2003-01-01
In the literature many works have been written dealing with the task of on-line calculation of temperature and thermal stress for machine components and structures, in order to evaluate fatigue damage accumulation and estimate residual life. One of the most widespread methodologies is the Green's function technique (GFT), by which machine parameters such as fluid temperatures, pressures and flow rates are converted into metal temperature transients and thermal stresses. However, since the GFT is based upon the linear superposition principle, it cannot be directly used in the case of varying heat transfer coefficients. In the present work, a different methodology is proposed, based upon CMS for temperature transient calculation and upon the GFT for the related thermal stress evaluation. This new approach allows variable heat transfer coefficients to be accounted for. The methodology is applied for two different case studies, taken from the literature: a thick pipe and a nozzle connected to a spherical head, both subjected to multiple convective boundary conditions
International Nuclear Information System (INIS)
Bray, Igor.
1992-04-01
The calculations of the 3 2 S and 3 2 P spin asymmetries and the angular momentum for singlet and triplet scattering for projectile energies of 10 and 20 eV is presented. Together these observables give a most stringent test of any electron-atom scattering theory. An excellent agreement was found between the results of the coupled-channel optical method and experiment, which for the spin asymmetries can only be obtained by a good description of the couplings between the lower-lying target states and the target continuum. 10 refs., 2 figs
Methodology to Calculate the ACE and HPQ Metrics Used in the Wave Energy Prize
Energy Technology Data Exchange (ETDEWEB)
Driscoll, Frederick R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weber, Jochem W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jenne, Dale S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Thresher, Robert W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fingersh, Lee J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bull, Dianna [Sandia National Laboratories; Dallman, Ann [Sandia National Laboratories; Gunawan, Budi [Sandia National Laboratories; Ruehl, Kelley [Sandia National Laboratories; Newborn, David [Naval Surface Warfare Center, Carderock Division; Quintero, Miguel [Naval Surface Warfare Center, Carderock Division; LaBonte, Alison [U.S. Department of Energy; Karwat, Darshan [U.S. Department of Energy; Beatty, Scott [Cascadia Coast Research Ltd.
2018-03-08
The U.S. Department of Energy's Wave Energy Prize Competition encouraged the development of innovative deep-water wave energy conversion technologies that at least doubled device performance above the 2014 state of the art. Because levelized cost of energy (LCOE) metrics are challenging to apply equitably to new technologies where significant uncertainty exists in design and operation, the prize technical team developed a reduced metric as proxy for LCOE, which provides an equitable comparison of low technology readiness level wave energy converter (WEC) concepts. The metric is called 'ACE' which is short for the ratio of the average climate capture width to the characteristic capital expenditure. The methodology and application of the ACE metric used to evaluate the performance of the technologies that competed in the Wave Energy Prize are explained in this report.
High performance shape annealing matrix (HPSAM) methodology for core protection calculators
International Nuclear Information System (INIS)
Cha, K. H.; Kim, Y. H.; Lee, K. H.
1999-01-01
In CPC(Core Protection Calculator) of CE-type nuclear power plants, the core axial power distribution is calculated to evaluate the safety-related parameters. The accuracy of the CPC axial power distribution highly depends on the quality of the so called shape annealing matrix(SAM). Currently, SAM is determined by using data measured during startup test and used throughout the entire cycle. An issue concerned with SAM is that it is fairly sensitive to measurements and thus the fidelity of SAM is not guaranteed for all cycles. In this paper, a novel method to determine a high-performance SAM (HPSAM) is proposed, where both measured and simulated data are used in determining SAM
A coupled RELAPS-3D/CFD methodology with a proof-of-principle calculation; TOPICAL
International Nuclear Information System (INIS)
Aumiller, D.L.; Tomlinson, E.T.; Bauer, R.C.
2000-01-01
The RELAP5-3D computer code was modified to make the explicit coupling capability in the code fully functional. As a test of the modified code, a coupled RELAP5/RELAP5 analysis of the Edwards-O'Brien blowdown problem was performed which showed no significant deviations from the standard RELAP5-3D predictions. In addition, a multiphase Computational Fluid Dynamics (CFD) code was modified to permit explicit coupling to RELAP5-3D. Several calculations were performed with this code. The first analysis used the experimental pressure history from a point just upstream of the break as a boundary condition. This analysis showed that a multiphase CFD code could calculate the thermodynamic and hydrodynamic conditions during a rapid blowdown transient. Finally, a coupled RELAP5/CFD analysis was performed. The results are presented in this paper
International Nuclear Information System (INIS)
Abreu, M.P. de.
1988-01-01
An alternative pseudo-harmonics method for two-dimensional reactor calculations is presented together with some one-energy group results, namely, eigenvalue and flux reconstruction. A brief description of the Standard and Modified versions of the method is presented for critical purposes, i.e., it was intended to discuss the previously developed versions and in some sense to improve the solution of the K-th eigenvalue and flux terms of the corresponding expansions. Intense and localized perturbations, where a significant imbalance between neutron production and destruction rates exists, were simulated. Since convergence in flux and eigenvalue were achieved for all test-cases, there is a tendency to consider the alternative method to be very promising for two-dimensional calculations. (author)
International Nuclear Information System (INIS)
Conti Filho, P.; Oliveira Barroso, A.C. de
1985-01-01
It was developed a computer code to generate polynomial coefficients which represent homogenized microscopic cross sections in function of the local accumulated burnup and concentration of soluble boron, presented in fuel element, for each step of burnup reactor. Afterward, it was developed a coupling between LEOPARD-GERADOR DE POLINOMIOS - CITATION computer codes to interpret and build homogenized microscopic cross sections according with local characteristics of each fuel element during the burnup calculation of reactor core. (M.C.K.) [pt
International Nuclear Information System (INIS)
Lee, Seung Min
2009-01-01
This work presents a theoretical study of reactor kinetics focusing on the methodology of calculation and the experimental measurements of the so-called kinetic parameters. A comparison between the methodology based on the Dulla's formalism and the classical method is made. The objective is to exhibit the dependence of the parameters on subcriticality level and perturbation. Two different slab type systems were considered: thermal one and fast one, both with homogeneous media. One group diffusion model was used for the fast reactor, and for the thermal system, two groups diffusion model, considering, in both case, only one precursor's family. The solutions were obtained using the expansion method. Also, descriptions of the main experimental methods of measurements of the kinetic parameters are presented in order to put a question about the compatibility of these methods in subcritical region. (author)
Directory of Open Access Journals (Sweden)
Stephen Carstens
2008-11-01
Full Text Available Companies tend to outsource transport to fleet management companies to increase efficiencies if transport is a non-core activity. The provision of fleet management services on contract introduces a certain amount of financial risk to the fleet management company, specifically fixed rate maintenance contracts. The quoted rate needs to be sufficient and also competitive in the market. Currently the quoted maintenance rates are based on the maintenance specifications of the manufacturer and the risk management approach of the fleet management company. This is usually reflected in a contingency that is included in the quoted maintenance rate. An alternative methodology for calculating the average maintenance cost for a vehicle fleet is proposed based on the actual maintenance expenditures of the vehicles and accepted statistical techniques. The proposed methodology results in accurate estimates (and associated confidence limits of the true average maintenance cost and can beused as a basis for the maintenance quote.
Energy Technology Data Exchange (ETDEWEB)
Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2017-04-11
Calculations for total cross sections and compound-nucleus (CN) formation cross sections for americium isotopes are described, for use in the 2017 NA-22 evaluation effort. The code ECIS 2006 was used in conjunction with Frank Dietrich's wrapper `runtemplate'.
International Nuclear Information System (INIS)
Gritzay, O.; Kalchenko, O.
2010-01-01
Full text: Scientific support of NPPs has to cover several important aspects of scientific and organization activity, namely:1.Training for group of high skilled specialists to do the following work: o nuclear data generation for engineer calculations; o engineer calculations to ensure the safety operation of NPPs; o experimental-calculation support of fluence dosimetry at NPP. 2.Development of up-to-date computer base, equipped with necessary program packages for nuclear data generation and engineer calculations. 3.The updated Libraries of Evaluated Nuclear Data (ENDF), such as ENDF/B-VII (USA), JENDL-3.3 (Japan) and JEFF-3.1 (Europe), RUSFOND ( Russia) and as a result the generation of specialized nuclear data multi-group libraries for special purpose engineer calculations.To reach these purposes, the Ukrainian Nuclear Data Center (UKRNDC) was organized and developed for more, than 10 years (since 1996).The capabilities of the UKRNDC are detailed below. o Modern ENDF libraries, first of all the general purpose libraries, such as ENDF/B-7.0, -6.8, JEFF-3.1.1, JENDL-3.3, etc. These databases contain recommended, evaluated cross sections, spectra, angular distributions, fission product yields, photo-atomic and thermal scattering law data, with emphasis on neutron induced reactions.o Codes for processing these data, updated to the last versions of ENDF and other libraries. First of all these are PREPRO 2007 package (Updated March 17, 2007) and NJOY package updated to versions NJOY-158 and NJOY-253 (in 2009). These codes may give the possibilities to produce the multi-group data for needed spectrum of interacting particles (neutrons, protons, gammas) and temperatures.o Computer base of several specialized server stations, such as ESCALA- S120 (analogous to IBM -240 with RISC 6000 processor) operating under OS under OS UNIX (version AIX 5.1) and IBM PC operating under Linux Red Hat 7.2.o The set of PC computers joined in UKRNDC network, operating mainly in OS Windows
International Nuclear Information System (INIS)
Nes, Razvan; Benke, Roland R.
2008-01-01
The U.S. Department of Energy (DOE) is currently considering design options for preclosure facilities in a license application for a geologic repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nevada. The Center for Nuclear Waste Regulatory Analyses (CNWRA) developed the PCSA Tool Version 3.0.0 software for the U.S. Nuclear Regulatory Commission (NRC) to aid in the regulatory review of a potential DOE license application. The objective of this paper is to demonstrate PCSA Tool modeling capabilities (i.e., a generic two-compartment, mass-balance model) for estimating radionuclide concentrations in air and radiological dose consequences to indoor workers in a control room from potential leakage of radioactively contaminated air from an adjacent handling area. The presented model computes internal and external worker doses from inhalation and submersion in a finite cloud of contaminated air in the control room and augments previous capabilities for assessing indoor worker dose. As a complement to the example event sequence frequency analysis in the companion paper, example consequence calculations are presented in this paper for the postulated event sequence. In conclusion: this paper presents a model for estimating radiological doses to indoor workers for the leakage of airborne radioactive material from handling areas. Sensitivity of model results to changes in various input parameters was investigated via illustrative example calculations. Indoor worker dose estimates were strongly dependent on the duration of worker exposure and the handling-area leakage flow rate. In contrast, doses were not very sensitive to handling-area exhaust ventilation flow rates. For the presented example, inhalation was the dominant radiological dose pathway. The two companion papers demonstrate independent analysis capabilities of the regulator for performing confirmatory calculations of frequency and consequence, which assist the assessment of worker
A source term and risk calculations using level 2+PSA methodology
International Nuclear Information System (INIS)
Park, S. I.; Jea, M. S.; Jeon, K. D.
2002-01-01
The scope of Level 2+ PSA includes the assessment of dose risk which is associated with the exposures of the radioactive nuclides escaping from nuclear power plants during severe accidents. The establishment of data base for the exposure dose in Korea nuclear power plants may contribute to preparing the accident management programs and periodic safety reviews. In this study the ORIGEN, MELCOR and MACCS code were employed to produce a integrated framework to assess the radiation source term risk. The framework was applied to a reference plant. Using IPE results, the dose rate for the reference plant was calculated quantitatively
DEFF Research Database (Denmark)
Gurtovenko, Andrey A; Vattulainen, Ilpo
2009-01-01
of the electrostatic potential from atomic-scale molecular dynamics simulations of lipid bilayers. We discuss two slightly different forms of Poisson equation that are normally used to calculate the membrane potential: (i) a classical form when the potential and the electric field are chosen to be zero on one...... systems). For symmetric bilayers we demonstrate that both approaches give essentially the same potential profiles, provided that simulations are long enough (a production run of at least 100 ns is required) and that fluctuations of the center of mass of a bilayer are properly accounted for. In contrast...
International Nuclear Information System (INIS)
De Roo, Guillaume; Parsons, John E.
2011-01-01
In this paper we show how the traditional definition of the levelized cost of electricity (LCOE) can be extended to alternative nuclear fuel cycles in which elements of the fuel are recycled. In particular, we define the LCOE for a cycle with full actinide recycling in fast reactors in which elements of the fuel are reused an indefinite number of times. To our knowledge, ours is the first LCOE formula for this cycle. Others have approached the task of evaluating this cycle using an 'equilibrium cost' concept that is different from a levelized cost. We also show how the LCOE implies a unique price for the recycled elements. This price reflects the ultimate cost of waste disposal postponed through the recycling, as well as other costs in the cycle. We demonstrate the methodology by estimating the LCOE for three classic nuclear fuel cycles: (i) the traditional Once-Through Cycle, (ii) a Twice-Through Cycle, and (iii) a Fast Reactor Recycle. Given our chosen input parameters, we show that the 'equilibrium cost' is typically larger than the levelized cost, and we explain why.
Monte-Carlo-calculations for the simulation of channelling-experiments with V3Si-single-crystals
International Nuclear Information System (INIS)
Kaufmann, R.
1978-05-01
The results of channelling-investigations on single-crystals of A15-type structure, like e.g. V 3 Si, are not directly comparable to analytical model-calculations. Therefore the channelling-process was simulated in a Monte-Carlo-program on the basis of the binary-collision-model. The calculated values for the minimum yield, Chisub(min), and the critical angle, Psisub(1/2), were in good agreement with the results of experiments with 2 MeV- 4 He + -particles. The lattice damage in the range of 2,000 Angstroem at the surface after an irradiation with a fluence of 6 x 10 16 - 4 He + /cm 2 at 300 KeV could be explained by normally distributed static displacements of the V-atoms with a mean value of 0.05 A. The transverse damage structure after an irradiation with a fluence of 1.5 x 10 16 - 4 He + /cm 2 at 50 KeV could be simulated by a step profile of 50% displacements of the V-atoms with a maximum value of 0.5 Angstroem at the depth of the projected range. (orig./HPOE) [de
Energy Technology Data Exchange (ETDEWEB)
Tucker, William C.; Schelling, Patrick K., E-mail: patrick.schelling@ucf.edu [Advanced Material Processing and Analysis Center and Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Orlando, Florida 32816 (United States)
2014-07-14
Computation of the heat of transport Q{sub a}{sup *} in monatomic crystalline solids is investigated using the methodology first developed by Gillan [J. Phys. C: Solid State Phys. 11, 4469 (1978)] and further developed by Grout and coworkers [Philos. Mag. Lett. 74, 217 (1996)], referred to as the Grout-Gillan method. In the case of pair potentials, the hopping of a vacancy results in a heat wave that persists for up to 10 ps, consistent with previous studies. This leads to generally positive values for Q{sub a}{sup *} which can be quite large and are strongly dependent on the specific details of the pair potential. By contrast, when the interactions are described using the embedded atom model, there is no evidence of a heat wave, and Q{sub a}{sup *} is found to be negative. This demonstrates that the dynamics of vacancy hopping depends strongly on the details of the empirical potential. However, the results obtained here are in strong disagreement with experiment. Arguments are presented which demonstrate that there is a fundamental error made in the Grout-Gillan method due to the fact that the ensemble of states only includes successful atom hops and hence does not represent an equilibrium ensemble. This places the interpretation of the quantity computed in the Grout-Gillan method as the heat of transport in doubt. It is demonstrated that trajectories which do not yield hopping events are nevertheless relevant to computation of the heat of transport Q{sub a}{sup *}.
Weissmannová, Helena Doležalová; Pavlovský, Jiří
2017-11-07
This article provides the assessment of heavy metal soil pollution with using the calculation of various pollution indices and contains also summarization of the sources of heavy metal soil pollution. Twenty described indices of the assessment of soil pollution consist of two groups: single indices and total complex indices of pollution or contamination with relevant classes of pollution. This minireview provides also the classification of pollution indices in terms of the complex assessment of soil quality. In addition, based on the comparison of metal concentrations in soil-selected sites of the world and used indices of pollution or contamination in soils, the concentration of heavy metal in contaminated soils varied widely, and pollution indices confirmed the significant contribution of soil pollution from anthropogenic activities mainly in urban and industrial areas.
International Nuclear Information System (INIS)
Le Borgne, E.; Mattei, A.; Rome, M.; Rodriguez, J.M.
2004-01-01
The determination of hydraulic characteristics for fuel subassembly components is dependent on the hypotheses and the methodology considered. The results of hydraulic compatibility calculations using input data from different sources may thus be difficult to analyse, and their reliability will consequently be reduced. Electricite de France (EDF) and Commissariat a l'Energie Atomique (CEA) have initiated a common program aiming at controlling the consequences of such a situation, increasing the reliability of the values used in the hydraulic compatibility calculations, and proposing a standardization of the operating procedures. In a first step, this program is based on the measurements performed in the CEA HERMES P facility. Extension of this program is expected to the equivalent experimental facilities for which sufficient information will be made available. (author)
International Nuclear Information System (INIS)
Oliveira, A.C.J.G. de.
1988-12-01
Sensitivity calculations are very important in design and safety of nuclear reactor cores. Large codes with a great number of physical considerations have been used to perform sensitivity studies. However, these codes need long computation time involving high costs. The perturbation theory has constituted an efficient and economical method to perform sensitivity analysis. The present work is an application of the perturbation theory (matricial formalism) to a simplified model of DNB (Departure from Nucleate Boiling) analysis to perform sensitivity calculations in PWR cores. Expressions to calculate the sensitivity coefficients of enthalpy and coolant velocity with respect to coolant density and hot channel area were developed from the proposed model. The CASNUR.FOR code to evaluate these sensitivity coefficients was written in Fortran. The comparison between results obtained from the matricial formalism of perturbation theory with those obtained directly from the proposed model makes evident the efficiency and potentiality of this perturbation method for nuclear reactor cores sensitivity calculations (author). 23 refs, 4 figs, 7 tabs
International Nuclear Information System (INIS)
Cintra, Felipe Belonsi de
2010-01-01
This study made a comparison between some of the major transport codes that employ the Monte Carlo stochastic approach in dosimetric calculations in nuclear medicine. We analyzed in detail the various physical and numerical models used by MCNP5 code in relation with codes like EGS and Penelope. The identification of its potential and limitations for solving microdosimetry problems were highlighted. The condensed history methodology used by MCNP resulted in lower values for energy deposition calculation. This showed a known feature of the condensed stories: its underestimates both the number of collisions along the trajectory of the electron and the number of secondary particles created. The use of transport codes like MCNP and Penelope for micrometer scales received special attention in this work. Class I and class II codes were studied and their main resources were exploited in order to transport electrons, which have particular importance in dosimetry. It is expected that the evaluation of available methodologies mentioned here contribute to a better understanding of the behavior of these codes, especially for this class of problems, common in microdosimetry. (author)
International Nuclear Information System (INIS)
Verduzco, Laura E.; Duffey, Michael R.; Deason, Jonathan P.
2007-01-01
At this time, hydrogen-based power plants and large hydrogen production facilities are capital intensive and unable to compete financially against hydrocarbon-based energy production facilities. An option to overcome this problem and foster the introduction of hydrogen technology is to introduce small and medium-scale applications such as residential and community hydrogen refueling units. Such units could potentially be used to generate both electricity and heat for the home, as well as hydrogen fuel for the automobile. Cost modeling for the integration of these three forms of energy presents several methodological challenges. This is particularly true since the technology is still in the development phase and both the financial and the environmental cost must be calculated using mainly secondary sources. In order to address these issues and aid in the design of small and medium-scale hydrogen systems, this study presents a computer model to calculate financial and environmental costs of this technology using different hydrogen pathways. The model can design and compare hydrogen refueling units against hydrocarbon-based technologies, including the 'gap' between financial and economic costs. Using the methodology, various penalties and incentives that can foster the introduction of hydrogen-based technologies can be added to the analysis to study their impact on financial cost
Hale, Lucas M.; Trautt, Zachary T.; Becker, Chandler A.
2018-07-01
Atomistic simulations using classical interatomic potentials are powerful investigative tools linking atomic structures to dynamic properties and behaviors. It is well known that different interatomic potentials produce different results, thus making it necessary to characterize potentials based on how they predict basic properties. Doing so makes it possible to compare existing interatomic models in order to select those best suited for specific use cases, and to identify any limitations of the models that may lead to unrealistic responses. While the methods for obtaining many of these properties are often thought of as simple calculations, there are many underlying aspects that can lead to variability in the reported property values. For instance, multiple methods may exist for computing the same property and values may be sensitive to certain simulation parameters. Here, we introduce a new high-throughput computational framework that encodes various simulation methodologies as Python calculation scripts. Three distinct methods for evaluating the lattice and elastic constants of bulk crystal structures are implemented and used to evaluate the properties across 120 interatomic potentials, 18 crystal prototypes, and all possible combinations of unique lattice site and elemental model pairings. Analysis of the results reveals which potentials and crystal prototypes are sensitive to the calculation methods and parameters, and it assists with the verification of potentials, methods, and molecular dynamics software. The results, calculation scripts, and computational infrastructure are self-contained and openly available to support researchers in performing meaningful simulations.
International Nuclear Information System (INIS)
Hansen, J.P.; Taulbjerg, K.; University of Tennessee, Knoxville, Tennessee 37996)
1989-01-01
Partial cross sections for electron capture in 1--50-keV collisions of Ar 6+ and Ar 8+ with atomic hydrogen have been calculated using an atomic expansion including two complete principal shells of final states (n=4,5 for Ar 6+ and n=5,6 for Ar 8+ ). The qualitative structure of the results is in good accord with a reaction window picture. The results for Ar 6+ ions are in agreement with published experimental data when precaution is taken with respect to uncertainties in absolute normalization of the data and with respect to a proper analysis of translation energy spectra at lower impact energies. The limited experimental data for Ar 8+ do not agree with the present results
Quantum calculations on water in the KcsA channel cavity with permeant and non-permeant ions
International Nuclear Information System (INIS)
Kariev, Alisher M.; Green, Michael E.
2009-01-01
Different ions in the pore of the KcsA channel behave differently, and we relate this to their solvation. We show that the selectivity is dependent, in part, on the solvation in the cavity (sometimes referred to as the vestibule, it is the region containing water molecules between the intracellular gate and the selectivity filter at the extracellular end of the pore). We have shown earlier that potassium is more dependent at the upper end of the cavity region on solvation by the threonines there, while sodium ion has more water molecules as ligands. In addition, sodium ion is placed asymmetrically, while potassium is nearly exactly symmetric with respect to the four-fold symmetry of the channel. We have now extended these calculations to rubidium and cesium ions, and find that rubidium solvation resembles that of potassium (and both are permeant ions), while cesium resembles sodium (and both are non-permeant), in terms of the geometry of up to eight hydrating, and four non-hydrating, water molecules. In each case, a maximum of 12 water molecules are relevant to the calculation. The placement of the water molecules in the two cases is essentially the same as found from the electron density in the X-ray structure of Zhou and MacKinnon. For Na + and K + , we show that energy decreases from bulk to the cavity to the lowest position in the selectivity filter (accurate energy could not be calculated for the heavier ions). A separate calculation shows that fixing the Na + ion at the position of the K + minimum, followed by re-optimization produced a significantly modified system, not something that could be produced by thermal fluctuations. Moving the K + into the Na + position in the upper cavity led to a small increase in energy, ∼ 3 k B T, but was accompanied by large shifts in the positions of hydrating waters, which would create a major kinetic barrier. Therefore, thermal fluctuations could not invalidate the conclusions of the main calculations.
International Nuclear Information System (INIS)
Camacho O, Juana; Burgos S, Javier Dario
2006-01-01
The aim of this work is to provide a practical tool to carry out environmental planning and management processes regarding the use of space, in a complex way including not only biophysical but socioeconomic criteria. In the context of river basin management the Environmental Social Pressure Index was created. This paper presents an Environmental Planning and Management definition, based on the Ecological Supporting Structure, as well as one of sustainability, worked out of several authors. This work offers the methodological sequence to design and calculate a customized Environmental Social Pressure Index according to the specific features of any given territory, using the conceptual framework developed earlier and the multivariate analysis and power laws tools. Finally we present an exercise to illustrate this process, developed for Cundinamarca for 1995
International Nuclear Information System (INIS)
Spanos, G.; Geltmacher, A.B.; Lewis, A.C.; Bingert, J.F.; Mehl, M.; Papaconstantopoulos, D.; Mishin, Y.; Gupta, A.; Matic, P.
2007-01-01
This paper provides a brief overview of a multidisciplinary effort at the Naval Research Laboratory aimed at developing a computationally-based methodology to assist in the design of advanced Naval steels. This program uses multiple computational techniques ranging from the atomistic length scale to continuum response. First-principles electronic structure calculations using density functional theory were employed, semi-empirical angular dependent potentials were developed based on the embedded atom method, and these potentials were used as input into Monte-Carlo and molecular dynamics simulations. Experimental techniques have also been applied to a super-austenitic stainless steel (AL6XN) to provide experimental input, guidance, verification, and enhancements to the models. These experimental methods include optical microscopy, scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction, and serial sectioning in conjunction with computer-based three-dimensional reconstruction and quantitative analyses. The experimental results are also used as critical input into mesoscale finite element models of materials response
International Nuclear Information System (INIS)
Aydogdu, K.
1998-01-01
Nine components determine the moderator-system heat load during full-power operation and during a reactor power transient in a CANDU reactor. The components that contribute to the total moderator-system heat load at any time consist of the heat generated in the calandria tubes, guide tubes and reactivity mechanisms, moderator and reflector; the heat transferred from calandria shell, the inner tubesheets and the fuel channels; and the heat gained from moderator pumps and heat lost from piping. The contributions from each of these components will vary with time during a reactor transient. The sources of heat that arise from the deposition of nuclear energy can be divided into two categories, viz., a) the neutronic component (which is directly proportional to neutronic power), which includes neutron energy absorption, prompt-fission gamma absorption and capture gamma absorption; and b) the fission-product decay-gamma component, which also varies with time after initiation of the transient. An equation was derived to calculate transient heat loads to the moderator. The equation includes two independent variables that are the neutronic power and fission-product decay-gamma power fractions during the transient and a constant term that represents the heat gained from moderator pumps and heat lost from piping. The calculated heat load in the moderator during steady-state full-power operation for a CANDU 6 reactor was compared with available measurements from the Point Lepreau, Wolsong 1 and Gentilly-2 nuclear generating stations. The calculated and measured values were in reasonably good agreement. (author)
International Nuclear Information System (INIS)
Garcia Gutierrez, M.E.; Sustacha Duo, D.
1993-01-01
The ODCM (Offsite Dose Calculation Manual), the official operational document for all nuclear power plants develops the details for the technical specifications for discharges and governs their practical application. The use of ODCM methodology for managing and controlling data associated with radioactive discharges, as well as the subsequent processing of this data to assess the radiological impact, requires and generates a large volume of data, which demands the frequent application of laborious and complex calculation processes, making computerization necessary. The computer application created for Almaraz NPP has the capacity to store and manage data on all discharges, evaluate their effects, presents reports and copies the information to be sent periodically to the CSN (Spanish Nuclear Regulatory Commission) on a magnetic tape. The radiological impact of an actual or possible discharge can be evaluated at anytime and, furthermore, general or particular reports and graphs on the discharges and doses over time can be readily obtained. The application is run on a personal computer under a relational database management system. This interactive application is based on menus and windows. (author)
International Nuclear Information System (INIS)
Changala, P. Bryan
2014-01-01
The bending and torsional degrees of freedom in S 1 acetylene, C 2 H 2 , are subject to strong vibrational resonances and rovibrational interactions, which create complex vibrational polyad structures even at low energy. As the internal energy approaches that of the barrier to cis-trans isomerization, these energy level patterns undergo further large-scale reorganization that cannot be satisfactorily treated by traditional models tied to local minima of the potential energy surface for nuclear motion. Experimental spectra in the region near the cis-trans transition state have revealed these complicated new patterns. In order to understand near-barrier spectroscopic observations and to predict the detailed effects of cis-trans isomerization on the rovibrational energy level structure, we have performed reduced dimension rovibrational variational calculations of the S 1 state. In this paper, we present the methodological details, several of which require special care. Our calculation uses a high accuracy ab initio potential surface and a fully symmetrized extended complete nuclear permutation inversion group theoretical treatment of a multivalued internal coordinate system that is appropriate for large amplitude bending and torsional motions. We also discuss the details of the rovibrational basis functions and their symmetrization, as well as the use of a constrained reduced dimension rovibrational kinetic energy operator
Directory of Open Access Journals (Sweden)
He Bin
2016-01-01
Full Text Available In order to optimize the layout of the conformal cooling channels in hot stamping tools, a response surface methodology and multi-objective optimization technique are proposed. By means of an Optimal Latin Hypercube experimental design method, a design matrix with 17 factors and 50 levels is generated. Three kinds of design variables, the radius Rad of the cooling channel, the distance H from the channel center to tool work surface and the ratio rat of each channel center, are optimized to determine the layout of cooling channels. The average temperature and temperature deviation of work surface are used to evaluate the cooling performance of hot stamping tools. On the basis of the experimental design results, quadratic response surface models are established to describe the relationship between the design variables and the evaluation objectives. The error analysis is performed to ensure the accuracy of response surface models. Then the layout of the conformal cooling channels is optimized in accordance with a multi-objective optimization method to find the Pareto optimal frontier which consists of some optimal combinations of design variables that can lead to an acceptable cooling performance.
International Nuclear Information System (INIS)
Liang, T.K.S.; Huan-Jen, Hung; Chin-Jang, Chang; Lance, Wang
2001-01-01
In light water reactors, particularly the pressurized water reactor (PWR), the severity of a LOCA (loss of coolant accident) will limit how high the reactor power can operate. Although the best-estimate LOCA licensing methodology can provide the greatest margin on the PCT (peak cladding temperature) evaluation during LOCA, it generally takes more resources to develop. Instead, implementation of evaluation models required by the Appendix K of 10 CFR 50 upon an advanced thermal-hydraulic platform can also enlarge significant margin between the highest calculated PCT and the safety limit of 2200 F. The compliance of the current RELAP5-3D code with Appendix K of 10 CFR50 has been evaluated, and it was found that there are ten areas where code assessment and/or further modifications were required to satisfy the requirements set forth in the Appendix K of 10 CFR 50. The associated models for LOCA consequent phenomenon analysis should follow the major concern of regulation and be expected to give more conservative results than those by the best-estimate methodology. They were required to predict the decay power level, the blowdown hydraulics, the blowdown heat transfer, the flooding rate, and the flooding heat transfer. All of the ten areas included in above classified simulations have been further evaluated and the RELAP5-3D has been successfully modified to fulfill the associated requirements. In addition, to verify and assess the development of the Appendix K version of RELAP5-3D, nine separate-effect experiments were adopted. Through the assessments against separate-effect experiments, the success of the code modification in accordance with the Appendix K of 10 CFR 50 was demonstrated. We will apply another six sets of integral-effect experiments in the next step to assure the integral conservatism of the Appendix K version of RELAP5-3D on LOCA licensing evaluation. (authors)
Hazwan, M. H. M.; Shayfull, Z.; Sharif, S.; Nasir, S. M.; Zainal, N.
2017-09-01
In injection moulding process, quality and productivity are notably important and must be controlled for each product type produced. Quality is measured as the extent of warpage of moulded parts while productivity is measured as a duration of moulding cycle time. To control the quality, many researchers have introduced various of optimisation approaches which have been proven enhanced the quality of the moulded part produced. In order to improve the productivity of injection moulding process, some of researches have proposed the application of conformal cooling channels which have been proven reduced the duration of moulding cycle time. Therefore, this paper presents an application of alternative optimisation approach which is Response Surface Methodology (RSM) with Glowworm Swarm Optimisation (GSO) on the moulded part with straight-drilled and conformal cooling channels mould. This study examined the warpage condition of the moulded parts before and after optimisation work applied for both cooling channels. A front panel housing have been selected as a specimen and the performance of proposed optimisation approach have been analysed on the conventional straight-drilled cooling channels compared to the Milled Groove Square Shape (MGSS) conformal cooling channels by simulation analysis using Autodesk Moldflow Insight (AMI) 2013. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 39.1% after optimisation for straight-drilled cooling channels and cooling time is the most significant factor contribute to the warpage condition and warpage have optimised by 38.7% after optimisation for MGSS conformal cooling channels. In addition, the finding shows that the application of optimisation work on the conformal cooling channels offers the better quality and productivity of the moulded part produced.
Non-local coupled-channels optical calculation of electron scattering by atomic hydrogen at 54.42 eV
International Nuclear Information System (INIS)
Ratnavelu, K.; McCarthy, I.E.
1990-01-01
The present study incorporates the non-local optical potentials for the continuum within the coupled-channels optical framework to study electron scattering from atomic hydrogen at 54.42 eV. Nine-state coupled-channels calculations with non-local and local continuum optical potentials were performed. The results for differential, total and ionization cross sections as well as the 2p angular correlation parameters λ and R are comparable with other non-perturbative calculations. There are still discrepancies between theory and experiment, particularly for λ and R at larger angles. (author)
Zhu, Jian; Bai, Tong; Gu, Jiabing; Sun, Ziwen; Wei, Yumei; Li, Baosheng; Yin, Yong
2018-04-27
To evaluate the effect of pretreatment megavoltage computed tomographic (MVCT) scan methodology on setup verification and adaptive dose calculation in helical TomoTherapy. Both anthropomorphic heterogeneous chest and pelvic phantoms were planned with virtual targets by TomoTherapy Physicist Station and were scanned with TomoTherapy megavoltage image-guided radiotherapy (IGRT) system consisted of six groups of options: three different acquisition pitches (APs) of 'fine', 'normal' and 'coarse' were implemented by multiplying 2 different corresponding reconstruction intervals (RIs). In order to mimic patient setup variations, each phantom was shifted 5 mm away manually in three orthogonal directions respectively. The effect of MVCT scan options was analyzed in image quality (CT number and noise), adaptive dose calculation deviations and positional correction variations. MVCT scanning time with pitch of 'fine' was approximately twice of 'normal' and 3 times more than 'coarse' setting, all which will not be affected by different RIs. MVCT with different APs delivered almost identical CT numbers and image noise inside 7 selected regions with various densities. DVH curves from adaptive dose calculation with serial MVCT images acquired by varied pitches overlapped together, where as there are no significant difference in all p values of intercept & slope of emulational spinal cord (p = 0.761 & 0.277), heart (p = 0.984 & 0.978), lungs (p = 0.992 & 0.980), soft tissue (p = 0.319 & 0.951) and bony structures (p = 0.960 & 0.929) between the most elaborated and the roughest serials of MVCT. Furthermore, gamma index analysis shown that, compared to the dose distribution calculated on MVCT of 'fine', only 0.2% or 1.1% of the points analyzed on MVCT of 'normal' or 'coarse' do not meet the defined gamma criterion. On chest phantom, all registration errors larger than 1 mm appeared at superior-inferior axis, which cannot be avoided with the smallest AP and RI
A flow-based methodology for the calculation of TSO to TSO compensations for cross-border flows
International Nuclear Information System (INIS)
Glavitsch, H.; Andersson, G.; Lekane, Th.; Marien, A.; Mees, E.; Naef, U.
2004-01-01
In the context of the development of the European internal electricity market, several methods for the tarification of cross-border flows have been proposed. This paper presents a flow-based method for the calculation of TSO to TSO compensations for cross-border flows. The basic principle of this approach is the allocation of the costs of cross-border flows to the TSOs who are responsible for these flows. This method is cost reflective, non-transaction based and compatible with domestic tariffs. It can be applied when limited data are available. Each internal transmission network is then modelled as an aggregated node, called 'supernode', and the European network is synthesized by a graph of supernodes and arcs, each arc representing all cross-border lines between two adjacent countries. When detailed data are available, the proposed methodology is also applicable to all the nodes and lines of the transmission network. Costs associated with flows transiting through supernodes or network elements are forwarded through the network in a way reflecting how the flows make use of the network. The costs can be charged either towards loads and exports or towards generations and imports. Combination of the two charging directions can also be considered. (author)
Energy Technology Data Exchange (ETDEWEB)
BARKER, S.A.
2006-07-27
Waste stored within tank farm double-shell tanks (DST) and single-shell tanks (SST) generates flammable gas (principally hydrogen) to varying degrees depending on the type, amount, geometry, and condition of the waste. The waste generates hydrogen through the radiolysis of water and organic compounds, thermolytic decomposition of organic compounds, and corrosion of a tank's carbon steel walls. Radiolysis and thermolytic decomposition also generates ammonia. Nonflammable gases, which act as dilutents (such as nitrous oxide), are also produced. Additional flammable gases (e.g., methane) are generated by chemical reactions between various degradation products of organic chemicals present in the tanks. Volatile and semi-volatile organic chemicals in tanks also produce organic vapors. The generated gases in tank waste are either released continuously to the tank headspace or are retained in the waste matrix. Retained gas may be released in a spontaneous or induced gas release event (GRE) that can significantly increase the flammable gas concentration in the tank headspace as described in RPP-7771. The document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 5 is the annual update of the methodology and calculations of the flammable gas Waste Groups for DSTs and SSTs.
Lin, Blossom Yen-Ju; Chao, Te-Hsin; Yao, Yuh; Tu, Shu-Min; Wu, Chun-Ching; Chern, Jin-Yuan; Chao, Shiu-Hsiung; Shaw, Keh-Yuong
2007-04-01
Previous studies have shown the advantages of using activity-based costing (ABC) methodology in the health care industry. The potential values of ABC methodology in health care are derived from the more accurate cost calculation compared to the traditional step-down costing, and the potentials to evaluate quality or effectiveness of health care based on health care activities. This project used ABC methodology to profile the cost structure of inpatients with surgical procedures at the Department of Colorectal Surgery in a public teaching hospital, and to identify the missing or inappropriate clinical procedures. We found that ABC methodology was able to accurately calculate costs and to identify several missing pre- and post-surgical nursing education activities in the course of treatment.
Kholod, N; Evans, M; Gusev, E; Yu, S; Malyshev, V; Tretyakova, S; Barinov, A
2016-03-15
This paper presents a methodology for calculating exhaust emissions from on-road transport in cities with low-quality traffic data and outdated vehicle registries. The methodology consists of data collection approaches and emission calculation methods. For data collection, the paper suggests using video survey and parking lot survey methods developed for the International Vehicular Emissions model. Additional sources of information include data from the largest transportation companies, vehicle inspection stations, and official vehicle registries. The paper suggests using the European Computer Programme to Calculate Emissions from Road Transport (COPERT) 4 model to calculate emissions, especially in countries that implemented European emissions standards. If available, the local emission factors should be used instead of the default COPERT emission factors. The paper also suggests additional steps in the methodology to calculate emissions only from diesel vehicles. We applied this methodology to calculate black carbon emissions from diesel on-road vehicles in Murmansk, Russia. The results from Murmansk show that diesel vehicles emitted 11.7 tons of black carbon in 2014. The main factors determining the level of emissions are the structure of the vehicle fleet and the level of vehicle emission controls. Vehicles without controls emit about 55% of black carbon emissions. Copyright © 2015 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Grunwald, G.; Mueller, E.
1983-08-01
For the computation of control rod oscillations in a flow channel we set up the differential equations for the non-stationary pressure distribution around the control elements which are coupled with the motion equations of the rods. The equation system is solved by means of a finite difference method. An example shows the efficiency of the numerical calculation procedure. (author)
Directory of Open Access Journals (Sweden)
Ellen A Struijk
Full Text Available BACKGROUND: Disability-Adjusted Life Years (DALYs have the advantage that effects on total health instead of on a specific disease incidence or mortality can be estimated. Our aim was to address several methodological points related to the computation of DALYs at an individual level in a follow-up study. METHODS: DALYs were computed for 33,507 men and women aged 20-70 years when participating in the EPIC-NL study in 1993-7. DALYs are the sum of the Years Lost due to Disability (YLD and the Years of Life Lost (YLL due to premature mortality. Premature mortality was defined as death before the estimated date of individual Life Expectancy (LE. Different methods to compute LE were compared as well as the effect of different follow-up periods using a two-part model estimating the effect of smoking status on health as an example. RESULTS: During a mean follow-up of 12.4 years, there were 69,245 DALYs due to years lived with a disease or premature death. Current-smokers had lost 1.28 healthy years of their life (1.28 DALYs 95%CI 1.10; 1.46 compared to never-smokers. The outcome varied depending on the method used for estimating LE, completeness of disease and mortality ascertainment and notably the percentage of extinction (duration of follow-up of the cohort. CONCLUSION: We conclude that the use of DALYs in a cohort study is an appropriate way to assess total disease burden in relation to a determinant. The outcome is sensitive to the LE calculation method and the follow-up duration of the cohort.
International Nuclear Information System (INIS)
Bray, Igor; Konovalov, D.A.; McCarthy, I.E.
1991-04-01
A coupled-channel optical method for electron-atom scattering is applied to elastic electron-sodium scattering at energies of 20, 22.1, 54.4, 100, and 150 eV. It is demonstrated that the effect of all the inelastic channels on elastic scattering may be well reproduced by the 'ab initio' calculated complex non-local polarization potential. Whilst the experiments generally agree at small angles and therefore agree on the total elastic cross section, there is considerable discrepancy at intermediate and backward angles. 9 refs., 2 tabs., 1 fig
International Nuclear Information System (INIS)
Pirotta, M.; Aquilina, D.; Bhikha, T.; Georg, D.
2005-01-01
The ESTRO formalism for monitor unit (MU) calculations was evaluated and implemented to replace a previous methodology based on dosimetric data measured in a full-scatter phantom. This traditional method relies on data normalised at the depth of dose maximum (z m ), as well as on the utilisation of the BJR 25 table for the conversion of rectangular fields into equivalent square fields. The treatment planning system (TPS) was subsequently updated to reflect the new beam data normalised at a depth z R of 10 cm. Comparisons were then carried out between the ESTRO formalism, the Clarkson-based dose calculation algorithm on the TPS (with beam data normalised at z m and z R ), and the traditional ''full-scatter'' methodology. All methodologies, except for the ''full-scatter'' methodology, separated head-scatter from phantom-scatter effects and none of the methodologies; except for the ESTRO formalism, utilised wedge depth dose information for calculations. The accuracy of MU calculations was verified against measurements in a homogeneous phantom for square and rectangular open and wedged fields, as well as blocked open and wedged fields, at 5, 10, and 20 cm depths, under fixed SSD and isocentric geometries for 6 and 10 MV. Overall, the ESTRO Formalism showed the most accurate performance, with the root mean square (RMS) error with respect to measurements remaining below 1% even for the most complex beam set-ups investigated. The RMS error for the TPS deteriorated with the introduction of a wedge, with a worse RMS error for the beam data normalised at z m (4% at 6 MV and 1.6% at 10 MV) than at z R (1.9% at 6 MV and 1.1% at 10 MV). The further addition of blocking had only a marginal impact on the accuracy of this methodology. The ''full-scatter'' methodology showed a loss in accuracy for calculations involving either wedges or blocking, and performed worst for blocked wedged fields (RMS errors of 7.1% at 6 MV and 5% at 10 MV). The origins of these discrepancies were
International Nuclear Information System (INIS)
Kyncl, J.
2001-04-01
Comparison calculations were performed for 8 experiments accomplished in 2000 on the LR-0 reactor. The MCNP4a code was applied using effective cross section data in the continuous representation as per the ENDF/B-VI library. (P.A.)
International Nuclear Information System (INIS)
Bray, I.; Konovalov, D.A.; McCarthy, I.E.
1991-01-01
A coupled-channel optical method for electron-atomic hydrogen scattering is presented in a form that treats both the projectile and the target electrons symmetrically. Elastic differential cross sections are calculated at a range of energies from 0.5 to 30 eV and are found to be in complete agreement with the absolute measurements, previously reported. Total and total ionization cross sections are also presented. 13 refs., 2 tabs., 2 figs
International Nuclear Information System (INIS)
Lopez Aldama, D.; Rodriguez Gual, R.
1998-01-01
Presently work intends to validate the models and programs used in the Nuclear Technology Center for calculating the critical position of control rods by means of the analysis of the measurements performed at the critical facility IPEN/MB-01. The lattice calculations were carried out with the WIMS/D4 code and for the global calculations the diffusion code SNAP-3D was used
2010-10-01
... rate under the ESRD prospective payment system effective January 1, 2011. 413.220 Section 413.220...-treatment base rate under the ESRD prospective payment system effective January 1, 2011. (a) Data sources. The methodology for determining the per treatment base rate under the ESRD prospective payment system...
International Nuclear Information System (INIS)
Pecchia, Marco; Vasiliev, Alexander; Leray, Olivier; Ferroukhi, Hakim; Pautz, Andreas
2015-01-01
A new methodology, referred to as manufacturing and technological parameters uncertainty quantification (MTUQ), is under development at Paul Scherrer Institut (PSI). Based on uncertainty and global sensitivity analysis methods, MTUQ aims at advancing state-of-the-art for the treatment of geometrical/material uncertainties in light water reactor computations, using the MCNPX Monte Carlo neutron transport code. The development is currently focused primarily on criticality safety evaluations (CSE). In that context, the key components are a dedicated modular interface with the MCNPX code and a user-friendly interface to model functional relationship between system variables. A unique feature is an automatic capability to parameterize variables belonging to so-called “repeated structures” such as to allow for perturbations of each individual element of a given system modelled with MCNPX. Concerning the statistical analysis capabilities, these are currently implemented through an interface with the ROOT platform to handle the random sampling design. This paper presents the current status of the MTUQ methodology development and a first assessment of an ongoing organisation for economic cooperation and development/nuclear energy agency benchmark dedicated to uncertainty analyses for CSE. The presented results illustrate the overall capabilities of MTUQ and underline its relevance in predicting more realistic results compared to a methodology previously applied at PSI for this particular benchmark. (author)
Directory of Open Access Journals (Sweden)
Y. Bakhshan
2015-01-01
Full Text Available Micro scale gas flows has attracted significant research interest in the last two decades. In this research, the fluid flow of gases in the stepped micro-channel at a wide range of Knudsen number has been analyzed with using the Lattice Boltzmann (MRT method. In the model, a modified second-order slip boundary condition and a Bosanquet-type effective viscosity are used to consider the velocity slip at the boundaries and to cover the slip and transition regimes of flow and to gain an accurate simulation of rarefied gases. It includes the slip and transition regimes of flow. The flow specifications such as pressure loss, velocity profile, streamline and friction coefficient at different conditions have been presented. The results show good agreement with available experimental data. The calculation shows that the friction coefficient decreases with increasing the Knudsen number and stepping the micro-channel has an inverse effect on the friction coefficient. Furthermore, a new correlation is suggested for calculation of the friction coefficient in the stepped micro-channel as below: C_f Re = 3.113+2.915/(1 +2 Kn+ 0.641 exp(3.203/(1 + 2 Kn
Energy Technology Data Exchange (ETDEWEB)
Ruth, M.; Timbario, T. A.; Timbario, T. J.; Laffen, M.
2011-01-01
Currently, several cost-per-mile calculators exist that can provide estimates of acquisition and operating costs for consumers and fleets. However, these calculators are limited in their ability to determine the difference in cost per mile for consumer versus fleet ownership, to calculate the costs beyond one ownership period, to show the sensitivity of the cost per mile to the annual vehicle miles traveled (VMT), and to estimate future increases in operating and ownership costs. Oftentimes, these tools apply a constant percentage increase over the time period of vehicle operation, or in some cases, no increase in direct costs at all over time. A more accurate cost-per-mile calculator has been developed that allows the user to analyze these costs for both consumers and fleets. The calculator was developed to allow simultaneous comparisons of conventional light-duty internal combustion engine (ICE) vehicles, mild and full hybrid electric vehicles (HEVs), and fuel cell vehicles (FCVs). This paper is a summary of the development by the authors of a more accurate cost-per-mile calculator that allows the user to analyze vehicle acquisition and operating costs for both consumer and fleets. Cost-per-mile results are reported for consumer-operated vehicles travelling 15,000 miles per year and for fleets travelling 25,000 miles per year.
Fereidonnejad, R.; Sadeghi, H.; Ghambari, M.
2018-03-01
In this work, the effect of multi-phonon excitation on heavy-ion fusion reactions has been studied and fusion barrier distributions of energy intervals near and below the Coulomb barrier have been studied for 16,17,18O + 16O reactions. The structure and deformation of nuclear projectiles have been studied. Given the adaptation of computations to experimental data, our calculations predict the behavior of reactions in intervals of energy in which experimental measurements are not available. In addition the S-factor for these reactions has been calculated. The results showed that the structure and deformation of a nuclear projectile are important factors. The S-factor, obtained in the coupled-channel calculations for the {}^{16}O + {}^{16}O, {}^{17}O +{}^{16}O and {}^{18}O +{}^{16}O reactions, showed good agreement with the experimental data and had a maximum value at an energy near 5, 4.5 and 4 MeV, respectively.
Energy Technology Data Exchange (ETDEWEB)
Chang, Jong Hwa; Lee, Jeong Yeon; Lee, Young Ouk; Sukhovitski, Efrem Sh [Korea Atomic Energy Research Institute, Taejeon (Korea)
2000-01-01
Programs SHEMMAN and OPTMAN (Version 6) have been developed for determinations of nuclear Hamiltonian parameters and for optical model calculations, respectively. The optical model calculations by OPTMAN with coupling schemes built on wave functions functions of non-axial soft-rotator are self-consistent, since the parameters of the nuclear Hamiltonian are determined by adjusting the energies of collective levels to experimental values with SHEMMAN prior to the optical model calculation. The programs have been installed at Nuclear Data Evaluation Laboratory of KAERI. This report is intended as a brief manual of these codes. 43 refs., 9 figs., 1 tabs. (Author)
International Nuclear Information System (INIS)
Bazhin, M.A.; Fedosenko, G.Eh.; Shiryaeva, N.M.; Mal'ko, M.V.
1986-01-01
It is shown that adiabatic non-equilibrium chemically reacting gas flow with energy exchange in a variable cross-section channel may be subdivided into five possible types: 1) quasi-equilibrium flow; 2) flow in the linear region of deviation from equilibrium state; 3) quasi-frozen flow; 4) flow in the linear region of deviation from frozen state; 5) non-equilibrium flow. Criteria of quasi-equilibrium and quazi-frozen flows, including factors of external action of chemically reacting gas on flow, allow to obtain simple but sufficiently reliable approximate method of calculation of flow parameters. The considered method for solving the problem of chemically reacting nitrogen tetroxide in the variable cross-section channel with energy exchange can be used for evaluation of chemical reaction kinetics on the flow parameter in the stages of axial-flow and radial-flow turbines and in another practical problems
Uncertainty analysis for hot channel
International Nuclear Information System (INIS)
Panka, I.; Kereszturi, A.
2006-01-01
The fulfillment of the safety analysis acceptance criteria is usually evaluated by separate hot channel calculations using the results of neutronic or/and thermo hydraulic system calculations. In case of an ATWS event (inadvertent withdrawal of control assembly), according to the analysis, a number of fuel rods are experiencing DNB for a longer time and must be regarded as failed. Their number must be determined for a further evaluation of the radiological consequences. In the deterministic approach, the global power history must be multiplied by different hot channel factors (kx) taking into account the radial power peaking factors for each fuel pin. If DNB occurs it is necessary to perform a few number of hot channel calculations to determine the limiting kx leading just to DNB and fuel failure (the conservative DNBR limit is 1.33). Knowing the pin power distribution from the core design calculation, the number of failed fuel pins can be calculated. The above procedure can be performed by conservative assumptions (e.g. conservative input parameters in the hot channel calculations), as well. In case of hot channel uncertainty analysis, the relevant input parameters (k x, mass flow, inlet temperature of the coolant, pin average burnup, initial gap size, selection of power history influencing the gap conductance value) of hot channel calculations and the DNBR limit are varied considering the respective uncertainties. An uncertainty analysis methodology was elaborated combining the response surface method with the one sided tolerance limit method of Wilks. The results of deterministic and uncertainty hot channel calculations are compared regarding to the number of failed fuel rods, max. temperature of the clad surface and max. temperature of the fuel (Authors)
International Nuclear Information System (INIS)
Kloss, Yu.Yu.
1985-01-01
Program package and numerical solution of the problem for a system of coupled equations used in optical model to solve a problem on low and mean energy neutron scattering on deformed nuclei, is considered. With these programs differnet scattering cross sections depending on the incident neutron energy on even-even and even-odd nuclei were obtained. The programm permits to obtain different scattering cross sections (elastic, inelastic), excitation cross sections of the first three energy levels of rotational band depending on the energy, angular distributions and neutron polarizations including excited channels. In the program there is possibility for accounting even-even nuclei octupole deformation
International Nuclear Information System (INIS)
Lima Filho, R.M.; Oliveira, L.F.S. de
1984-01-01
A general method for the calculation of the time evolution of source terms related to irradiated fuel is presented. Some applications are discussed which indicated that the method can provide important informations for the engineering design and safety analysis of a temporary storage facility of irradiated fuel elements. (Author) [pt
Al Zain, Jamal; El Hajjaji, O.; El Bardouni, T.; Boukhal, H.; Jaï, Otman
2018-06-01
The MNSR is a pool type research reactor, which is difficult to model because of the importance of neutron leakage. The aim of this study is to evaluate a 2-D transport model for the reactor compatible with the latest release of the DRAGON code and 3-D diffusion of the DONJON code. DRAGON code is then used to generate the group macroscopic cross sections needed for full core diffusion calculations. The diffusion DONJON code, is then used to compute the effective multiplication factor (keff), the feedback reactivity coefficients and neutron flux which account for variation in fuel and moderator temperatures as well as the void coefficient have been calculated using the DRAGON and DONJON codes for the MNSR research reactor. The cross sections of all the reactor components at different temperatures were generated using the DRAGON code. These group constants were used then in the DONJON code to calculate the multiplication factor and the neutron spectrum at different water and fuel temperatures using 69 energy groups. Only one parameter was changed where all other parameters were kept constant. Finally, Good agreements between the calculated and measured have been obtained for every of the feedback reactivity coefficients and neutron flux.
2011-01-01
The invention relates to a method for calculating perception of the user experience of the quality of monitored integrated telecommunications operator services. For this purpose, data from the monitoring of user services is used, along with questionnaires previously completed by a representative
International Nuclear Information System (INIS)
Coelho, C.P.
1983-01-01
A methodology for estimating the radiation doses to the members of the general public, in the vicinity of uranium mines and mills is presented. The data collected in the surveys performed to characterize the neighborhood of the site, and used in this work to estimate the radiation dose, are required by the Regulatory Body, for the purpose of Licensing. Initially, a description is shown of the main processing steps to obtain the uranium concentrate and the critical instalation radionuclides are identified. Following, some studies required to characterize the facility neighborhood are presented, specially those related to geography, demography, metheorology, hydrology and environmental protection. Also, the basic programs for monitoring the facility neighborhood in the pre-operational and operational phases are included. It is then proposed a procedure to estimate inhalation, ingestion and external doses. As an example, the proposed procedure is applied to a hypotetical site. Finally, some aspects related to the applicability of this work are discussed. (Author) [pt
International Nuclear Information System (INIS)
Caneparo, B.; Zirilli, S.
1987-01-01
In this work relating to support structures for seismic tests, the authors present a mixed procedure necessitating the experimental measurement of natural frequencies, dampings, and the response to impulse stresses (in the case of a seismic stress, the subject of this study, a single impulse is sufficient) in the zone in question. Experimental measurements are used to adjust the finite elements model; it may then be used for later studies. In the presence of interaction with structures not included in the model, such as, for example, the means used for the actual test, it is impossible to adjust it according to the methods proposed and it is up to the experienced author to introduce the modifications judged opportune to take into account everything which is not a part of the model. The authors have, however, carried out a programme based on the local modification of Young's module, which uses only natural frequencies, useful in the adjustment process. Once the zone of poor modelling has been found, this programme enables optimizing the value of E as a function of the experimental data, whilst also furnishing an estimate of residual differences. Dynamic tests have shown that the model thus obtained can be refined by the forced impulse to an impulse stress. In addition to setting out the theories and formulae used, we then give account of verification of the methodology using a plate, and of its application to a support structure in the form of a frame for seismic tests. The appendices include both experimental measurements and tests. The authors carried out the modal analysis with even greater care than necessary in view of the methodology verification phase
Energy Technology Data Exchange (ETDEWEB)
Niquet, Yann-Michel, E-mail: yniquet@cea.fr; Nguyen, Viet-Hung; Duchemin, Ivan [L-Sim, SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble (France); Triozon, François [CEA, LETI-MINATEC, Grenoble (France); Nier, Olivier; Rideau, Denis [ST Microelectronics, Crolles (France)
2014-02-07
We discuss carrier mobilities in the quantum Non-Equilibrium Green's Functions (NEGF) framework. We introduce a method for the extraction of the mobility that is free from contact resistance contamination and with minimal needs for ensemble averages. We focus on silicon thin films as an illustration, although the method can be applied to various materials such as semiconductor nanowires or carbon nanostructures. We then introduce a new paradigm for the definition of the partial mobility μ{sub M} associated with a given elastic scattering mechanism “M,” taking phonons (PH) as a reference (μ{sub M}{sup −1}=μ{sub PH+M}{sup −1}−μ{sub PH}{sup −1}). We argue that this definition makes better sense in a quantum transport framework as it is free from long range interference effects that can appear in purely ballistic calculations. As a matter of fact, these mobilities satisfy Matthiessen's rule for three mechanisms [e.g., surface roughness (SR), remote Coulomb scattering (RCS) and phonons] much better than the usual, single mechanism calculations. We also discuss the problems raised by the long range spatial correlations in the RCS disorder. Finally, we compare semi-classical Kubo-Greenwood (KG) and quantum NEGF calculations. We show that KG and NEGF are in reasonable agreement for phonon and RCS, yet not for SR. We discuss the reasons for these discrepancies.
International Nuclear Information System (INIS)
Sievers, Juergen; Heckmann, Klaus; Blaesius, Christoph
2015-06-01
For the demonstration of break preclusion for pressure retaining components in nuclear power plants, the nuclear safety standard KTA 3206 determines also the requirements for the leak-before-break verification. For this procedure, it has to be ensured that a wall-penetrating crack is subcritical with respect to instable growth, and that the resulting leakage under stationary operation conditions can be detected by a leak detection system. Within the scope of the project 3613R01332 analyses with respect to conservative estimates of the leak rates in case of detections regarding break preclusion were performed by means of leak rate models being available at GRS. For this purpose, conservative assumptions in the procedure were quantified by comparative calculations concerning selected leak rate experiments and the requirements regarding the determination of leak rates indicated in the KTA 3206 were verified and specified. Moreover, the models were extended and relevant recommendations for the calculation procedure were developed. During the investigations of leak rate tests the calculation methods were validated, qualified by means of both examples indicated in KTA 3206 and applied to a postulated leak accident in the cooling circuit of a PWR. For the calculation of leak rates several simplified solution methods which are included in the GRS program WinLeck were applied, and for the simulation of a leak accident the large-scale programs ANSYS Mechanical and ATHLET (thermohydraulics program developed by GRS) were used. When applying simplified methods for the calculation of leak rates using the limiting curve for the friction factor which has been derived during the project and which is included in the KTA 3206 attention has to be paid to the fact that in case of small flow lengths the entrance loss can dominate compared to the friction loss. However, the available data do not suffice in order to make a quantitative statement with respect to limits of applicability
International Nuclear Information System (INIS)
Panka, I.; Kereszturi, A.
2014-01-01
The assessment of the uncertainties of COBRA-IIIC thermal-hydraulic analyses of rod bundles is performed for a 5-by-5 bundle representing a PWR fuel assembly. In the first part of the paper the modeling uncertainties are evaluated in the term of the uncertainty of the turbulent mixing factor using the OECD NEA/NRC PSBT benchmark data. After that the uncertainties of the COBRA calculations are discussed performing Monte-Carlo type statistical analyses taking into account the modeling uncertainties and other uncertainties prescribed in the OECD NEA UAM benchmark specification. Both steady-state and transient cases are investigated. The target quantities are the uncertainties of the void distribution, the moderator density, the moderator temperature and the DNBR. We will see that - beyond the uncertainties of the geometry and the boundary conditions - it is very important to take into account the modeling uncertainties in case of bundle or sub-channel thermo-hydraulic calculations.
Lan, Linxin; Li, Tianduo; Wei, Tao; Pang, He; Sun, Tao; Wang, Enhua; Liu, Haixia; Niu, Qingfen
2018-03-01
An oligothiophene-based colorimetric and ratiometric fluorescence dual-channel cyanide chemosensor 3 T-2CN was reported. Sensor 3 T-2CN showed both naked-eye recognition and ratiometric fluorescence response for CN- with an excellent selectivity and high sensitivity. The sensing mechanism based on the nucleophilic attack of CN- on the vinyl Cdbnd C bond has been successfully confirmed by the optical measurements, 1H NMR titration, FT-IR spectra as well as the DFT/TD-DFT calculations. Moreover, the detection limit was calculated to be 0.19 μM, which is much lower than the maximum permission concentration in drinking water (1.9 μM). Importantly, test strips (filter paper and TLC plates) containing 3 T-2CN were fabricated, which could act as a practical and efficient solid state optical sensor for CN- in field measurements.
International Nuclear Information System (INIS)
Ledoux, Sebastien; Chotard, David; Mazeiraud, Vincent; Garcia, Nicolas; Saillard, Thibault; Mensencal, Yvon; Mouslim, Hakim
2015-01-01
Faced with the development of Marine Renewable Energy (MRE) in recent years and demand from regional public authorities to evaluate the energy potential of their coastal domains, it was necessary to design an integrated tool for determining, at the scale of a site and then a region, first the gross resource per energy type and then its technical potential followed by its technico-economic potential. In response to this need, Artelia mobilised its experts in maritime and river hydraulics and in energy with the aim of developing a tool dedicated to calculating MRE production capacities. With this operational objective in mind, ARTELIA undertook R and D actions in order to determine the state of the art in calculation methods and in tools already developed and in use in other European countries spearheading this activity, especially the United Kingdom (Atlas of UK Marine Renewable Energy Resources, ABPmer,) and the United States (in particular the work of the EPRI (Electric Power Research Institute)). The tool was then developed and applied successively in the framework of calculating the MRE potential of the coastal domain of the Poitou-Charentes region (client: Poitou-Charentes regional council), then through study assessments performed on the marine current power potential of Lower Normandy (client: DREAL Basse-Normandie) and on the MRE potential of the Aquitaine coast (client: Aquitaine regional council - GIP Littoral Aquitain). The tool allows for the assessment of the resources, technical and techno-economic potentials It has been applied to the following topics: marine current power (offshore and in estuaries and rivers), wave power (offshore, near-shore and coastal) and wind power (offshore and floating turbines). This article provides a brief summary of the various aspects of the tool implemented, illustrated through a few examples drawn from the studies referred to above. (authors)
Energy Technology Data Exchange (ETDEWEB)
Mead, H [Christian Brothers University, Memphis, TN (United States); St. Jude Children’s Research Hospital, Memphis, TN (United States); Brady, S; Kaufman, R [St. Jude Children’s Research Hospital, Memphis, TN (United States)
2016-06-15
Purpose: To discover if a previously published methodology for estimating patient-specific organ dose in a pediatric population (5–55kg) is translatable to the adult sized patient population (> 55 kg). Methods: An adult male anthropomorphic phantom was scanned with metal oxide semiconductor field effect transistor (MOSFET) dosimeters placed at 23 organ locations in the chest and abdominopelvic regions to determine absolute organ dose. Organ-dose-to-SSDE correlation factors were developed by dividing individual phantom organ doses by SSDE of the phantom; where SSDE was calculated at the center of the scan volume of the chest and abdomen/pelvis separately. Organ dose correlation factors developed in phantom were multiplied by 28 chest and 22 abdominopelvic patient SSDE values to estimate organ dose. The median patient weight from the CT examinations was 68.9 kg (range 57–87 kg) and median age was 17 years (range 13–28 years). Calculated organ dose estimates were compared to published Monte Carlo simulated patient and phantom results. Results: Organ-dose-to-SSDE correlation was determined for a total of 23 organs in the chest and abdominopelvic regions. For organs fully covered by the scan volume, correlation in the chest (median 1.3; range 1.1–1.5) and abdominopelvic (median 0.9; range 0.7–1.0) was 1.0 ± 10%. For organs that extended beyond the scan volume (i.e. skin bone marrow and bone surface) correlation was determined to be a median of 0.3 (range 0.1–0.4). Calculated patient organ dose using patient SSDE agreed to better than 6% (chest) and 15% (abdominopelvic) to published values. Conclusion: This study demonstrated that our previous published methodology for calculating organ dose using patient-specific SSDE for the chest and abdominopelvic regions is translatable to adult sized patients for organs fully covered by the scan volume.
van Setten, M. J.; Giantomassi, M.; Gonze, X.; Rignanese, G.-M.; Hautier, G.
2017-10-01
The search for new materials based on computational screening relies on methods that accurately predict, in an automatic manner, total energy, atomic-scale geometries, and other fundamental characteristics of materials. Many technologically important material properties directly stem from the electronic structure of a material, but the usual workhorse for total energies, namely density-functional theory, is plagued by fundamental shortcomings and errors from approximate exchange-correlation functionals in its prediction of the electronic structure. At variance, the G W method is currently the state-of-the-art ab initio approach for accurate electronic structure. It is mostly used to perturbatively correct density-functional theory results, but is, however, computationally demanding and also requires expert knowledge to give accurate results. Accordingly, it is not presently used in high-throughput screening: fully automatized algorithms for setting up the calculations and determining convergence are lacking. In this paper, we develop such a method and, as a first application, use it to validate the accuracy of G0W0 using the PBE starting point and the Godby-Needs plasmon-pole model (G0W0GN @PBE) on a set of about 80 solids. The results of the automatic convergence study utilized provide valuable insights. Indeed, we find correlations between computational parameters that can be used to further improve the automatization of G W calculations. Moreover, we find that G0W0GN @PBE shows a correlation between the PBE and the G0W0GN @PBE gaps that is much stronger than that between G W and experimental gaps. However, the G0W0GN @PBE gaps still describe the experimental gaps more accurately than a linear model based on the PBE gaps. With this paper, we hence show that G W can be made automatic and is more accurate than using an empirical correction of the PBE gap, but that, for accurate predictive results for a broad class of materials, an improved starting point or some
Fulkerson, David E.
2010-02-01
This paper describes a new methodology for characterizing the electrical behavior and soft error rate (SER) of CMOS and SiGe HBT integrated circuits that are struck by ions. A typical engineering design problem is to calculate the SER of a critical path that commonly includes several circuits such as an input buffer, several logic gates, logic storage, clock tree circuitry, and an output buffer. Using multiple 3D TCAD simulations to solve this problem is too costly and time-consuming for general engineering use. The new and simple methodology handles the problem with ease by simple SPICE simulations. The methodology accurately predicts the measured threshold linear energy transfer (LET) of a bulk CMOS SRAM. It solves for circuit currents and voltage spikes that are close to those predicted by expensive 3D TCAD simulations. It accurately predicts the measured event cross-section vs. LET curve of an experimental SiGe HBT flip-flop. The experimental cross section vs. frequency behavior and other subtle effects are also accurately predicted.
International Nuclear Information System (INIS)
Kythreotou, Nicoletta; Florides, Georgios; Tassou, Savvas A.
2012-01-01
On-farm energy consumption is becoming increasingly important in the context of rising energy costs and concerns over greenhouse gas emissions. For farmers throughout the world, energy inputs represent a major and rapidly increasing cost. In many countries such as Cyprus, however, there is lack of systematic research on energy use in agriculture, which hinders benchmarking end evaluation of approaches and investment decisions for energy improvement. This study established a methodology for the estimation of the direct consumption of fossil fuels and electricity for livestock breeding, excluding transport, for locations where full data sets are not available. This methodology was then used to estimate fossil fuel and electricity consumption for livestock breeding in Cyprus. For 2008, this energy was found to be equivalent to 40.3 GWh that corresponds to 8% of the energy used in agriculture. Differences between the energy consumption per animal in Cyprus and other countries was found to be mainly due to differences in climatic conditions and technologies used in the farms. -- Highlights: ► A methodology to calculate energy consumption in farming applied to Cyprus. ► Annual consumption per animal was estimated to be 565 kWh/cow, 537 kWh/sow and 0.677 kWh/chicken. ► Direct energy consumption in livestock breeding is estimated at 40.3 GWh in 2008.
Energy Technology Data Exchange (ETDEWEB)
Teke, T; Milette, MP [BC Cancer Agency Centre for the Southern Interior (Canada); Huang, V; Thomas, SD [BC Cancer Agency Fraser Valley Cancer Centre (Canada)
2014-08-15
The interplay effect between the tumor motion and the radiation beam modulation during a VMAT treatment delivery alters the delivered dose distribution from the planned one. This work present and validate a method to accurately calculate the dose distribution in 4D taking into account the tumor motion, the field modulation and the treatment starting phase. A QUASAR™ respiratory motion phantom was 4D scanned with motion amplitude of 3 cm and with a 3 second period. A static scan was also acquired with the lung insert and the tumor contained in it centered. A VMAT plan with a 6XFFF beam was created on the averaged CT and delivered on a Varian TrueBeam and the trajectory log file was saved. From the trajectory log file 10 VMAT plans (one for each breathing phase) and a developer mode XML file were created. For the 10 VMAT plans, the tumor motion was modeled by moving the isocentre on the static scan, the plans were re-calculated and summed in the treatment planning system. In the developer mode, the tumor motion was simulated by moving the couch dynamically during the treatment. Gafchromic films were placed in the QUASAR phantom static and irradiated using the developer mode. Different treatment starting phase were investigated (no phase shift, maximum inhalation and maximum exhalation). Calculated and measured isodose lines and profiles are in very good agreement. For each starting phase, the dose distribution exhibit significant differences but are accurately calculated with the methodology presented in this work.
Li, Changping; Park, Kihong; Alouini, Mohamed-Slim
2015-01-01
In this letter, we propose a fast numerical solution for the steady state radiative transfer equation based on the approach in [1] in order to calculate the optical path loss of light propagation suffering from attenuation due to the absorption and scattering in various water types. We apply an optimal non-uniform method to discretize the angular space and an upwind type finite difference method to discretize the spatial space. A Gauss-Seidel iterative method is then applied to solve the fully discretized system of linear equations. Finally, we extend the resulting radiance in 2-dimensional to 3-dimensional by the azimuthal symmetric assumption to compute the received optical power under the given receiver aperture and field of view. The accuracy and efficiency of the proposed scheme are validated by uniform RTE solver and Monte Carlo simulations.
Li, Changping
2015-07-22
In this letter, we propose a fast numerical solution for the steady state radiative transfer equation based on the approach in [1] in order to calculate the optical path loss of light propagation suffering from attenuation due to the absorption and scattering in various water types. We apply an optimal non-uniform method to discretize the angular space and an upwind type finite difference method to discretize the spatial space. A Gauss-Seidel iterative method is then applied to solve the fully discretized system of linear equations. Finally, we extend the resulting radiance in 2-dimensional to 3-dimensional by the azimuthal symmetric assumption to compute the received optical power under the given receiver aperture and field of view. The accuracy and efficiency of the proposed scheme are validated by uniform RTE solver and Monte Carlo simulations.
Energy Technology Data Exchange (ETDEWEB)
WEBER RA
2009-01-16
a waste group B (or A) tank identifies the potential for an induced flammable gas release hazard, the hazard only exists for specific operations that can release the retained gas in the tank at a rate and quantity that results in reaching 100% of the lower flammability limit in the tank headspace. The identification and evaluation of tank farm operations that could cause an induced flammable gas release hazard in a waste group B (or A) tank are included in other documents. The third criterion is the buoyancy ratio. This criterion addresses tanks that are not waste group C double-shell tanks and have an energy ratio {ge} 3.0. For these double-shell tanks, the buoyancy ratio considers whether the saturated solids can retain sufficient gas to exceed neutral buoyancy relative to the supernatant layer and therefore have buoyant displacement gas release events. If the buoyancy ratio is {ge} 1.0, that double-shell tank is assigned to waste group A. These tanks are considered to have a potential spontaneous buoyant displacement flammable gas release hazard in addition to a potential induced flammable gas release hazard. This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 8 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs.
Energy Technology Data Exchange (ETDEWEB)
FOWLER KD
2007-12-27
This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 7 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs. The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient
Energy Technology Data Exchange (ETDEWEB)
Cecenas F, M., E-mail: mcf@iie.org.mx [Instituto Nacional de Electricidad y Energias Limpias, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)
2017-09-15
A parallel channel model with boiling and punctual neutron kinetics is used to compare the implementation of its programming in C language through a conventional scheme and through a parallel programming scheme. In both cases the subroutines written in C are practically the same, but they vary in the way of controlling the execution of the tasks that calculate the different channels. Parallel Virtual Machine is used for the parallel solution, which allows the passage of messages between tasks to control convergence and transfer the variables of interest between the tasks that run simultaneously on a platform equipped with a multi-core microprocessor. For some problems defined as a study case, such as the one presented in this paper, a computer with two cores can reduce the computation time to 54-56% of the time required by the same program in its conventional sequential version. Similarly, a processor with four cores can reduce the time to 22-33% of execution time of the conventional serial version. These results of substantially reducing the computation time are very motivating of all those applications that can be prepared to be parallelized and whose execution time is an important factor. (Author)
Energy Technology Data Exchange (ETDEWEB)
Boermans, T.; Bettgenhaeuser, K.; Hermelink, A.; Schimschar, S. [Ecofys, Utrecht (Netherlands)
2011-05-15
On the European level, the principles for the requirements for the energy performance of buildings are set by the Energy Performance of Buildings Directive (EPBD). Dating from December 2002, the EPBD has set a common framework from which the individual Member States in the EU developed or adapted their individual national regulations. The EPBD in 2008 and 2009 underwent a recast procedure, with final political agreement having been reached in November 2009. The new Directive was then formally adopted on May 19, 2010. Among other clarifications and new provisions, the EPBD recast introduces a benchmarking mechanism for national energy performance requirements for the purpose of determining cost-optimal levels to be used by Member States for comparing and setting these requirements. The previous EPBD set out a general framework to assess the energy performance of buildings and required Member States to define maximum values for energy delivered to meet the energy demand associated with the standardised use of the building. However it did not contain requirements or guidance related to the ambition level of such requirements. As a consequence, building regulations in the various Member States have been developed by the use of different approaches (influenced by different building traditions, political processes and individual market conditions) and resulted in different ambition levels where in many cases cost optimality principles could justify higher ambitions. The EPBD recast now requests that Member States shall ensure that minimum energy performance requirements for buildings are set 'with a view to achieving cost-optimal levels'. The cost optimum level shall be calculated in accordance with a comparative methodology. The objective of this report is to contribute to the ongoing discussion in Europe around the details of such a methodology by describing possible details on how to calculate cost optimal levels and pointing towards important factors and
International Nuclear Information System (INIS)
Botero, Camilo; Yuri, Hurtado; Gonzalez, Jose
2008-01-01
This paper presents a new methodology to calculate carrying capacity in tourist beaches, further than merely environmental issues. Moreover, it understands beaches as complex systems towards its sustainable development. Five beaches in the North Caribbean coast of Colombia were chosen and classified in four tourism beach sorts: intensive, conservation, shared and ethnic. The analysis was done with legal framework review, fieldwork and indicators design, within three components: environmental support, urban infrastructure and tourist services. A new model to calculate carrying capacity in tourist beaches was created, and later applied on the study beaches. Current conditions of the five beaches were highlighted, their tourist carrying capacity were calculated and more important actions in each component were recommended. The main conclusion foster to take in consideration natural conditions as a core factor in beach management, but including a holistic approach in making decision process. Also this paper showed the current conditions of Colombian beaches as a warning, giving recommendations in short and medium term. This document is result of the project Determinacion de un sistema de calificacion y certificacion de playas turisticas.
Cheng, Liang; Xu, Hao; Li, Shuyi; Chen, Yanming; Zhang, Fangli; Li, Manchun
2018-04-01
As the rate of urbanization continues to accelerate, the utilization of solar energy in buildings plays an increasingly important role in sustainable urban development. For this purpose, we propose a LiDAR-based joint approach for calculating the solar irradiance incident on roofs and façades of buildings at city scale, which includes a methodology for calculating solar irradiance, the validation of the proposed method, and analysis of its application. The calculation of surface irradiance on buildings may then inform photovoltaic power generation simulations, architectural design, and urban energy planning. Application analyses of the proposed method in the experiment area found that: (1) Global and direct irradiations vary significantly by hour, day, month and season, both following the same trends; however, diffuse irradiance essentially remains unchanged over time. (2) Roof irradiation, but not façade irradiation, displays distinct time-dependent patterns. (3) Global and direct irradiations on roofs are highly correlated with roof aspect and slope, with high global and direct irradiations observed on roofs of aspect 100-250° and slopes of 0-60°, whereas diffuse irradiation on roofs is only affected by roof slope. (4) The façade of a building receives higher levels of global and direct irradiations if facing southeast, south, and southwest; however, diffuse irradiation remains constant regardless of façade orientation.
International Nuclear Information System (INIS)
Stefani, Giovanni Laranjo de
2009-01-01
This work proceeds the elaboration of a computational program for execution of various neutron and thermalhydraulic calculation methodology programs of the IEA-R1-Sao Paulo, Brazil, making the process more practical and safe, besides transforming de output data of each program an automatic process. This reactor is largely used for production of radioisotopes for medical use, material irradiation, personnel training and also for basic research. For that purposes it is necessary to change his core configuration in order to adapt the reactor for different uses. The work will transform various existent programs into subroutines of a principal program, i.e.,a program which call each of the programs automatically when necessary, and create another programs for manipulation the output data and therefore making practical the process
International Nuclear Information System (INIS)
Prodea, Iosif; Patrulescu, Ilie; Rizoiu, Andrei; Danila, Nicolae; Prisecaru, Ilie
2007-01-01
One of the most important CANDU reactor regulation system is the Adjuster Rods System (ADJ). The individual and bank calibration and performance evaluation of this system is carried out during the Phase B commissioning. The ADJ rods are grouped into seven banks based on full power reactivity control requirements. The Cernavoda Unit 2 adjuster rods characteristics were designed more than twenty years ago at INR Pitesti in the end of a fruitful collaboration between INR Pitesti (as designer) and Bristol Aerospace Limited (as manufacturer). In 1996, during the Phase B commissioning tests only AECL diffusion and Westcott approximation methodology was used. An alternative integral transport and high-modes diffusion approximation methodology was developed in INR Pitesti during the last years. As a result, the first collision probability code PIJXYZ was created and developed to carry out the supercell calculations as well as the code DIREN for 3D diffusion-based core simulations. The aim of this work was to evaluate comparatively the two adjuster rods systems (from Unit 1 and 2) in commissioning conditions. The concrete results will consist of individual, bank and total adjuster rods reactivity estimations with an emphasis on the differences and similarities between them. (authors)
International Nuclear Information System (INIS)
Tsiakalos, Miltiadis F.; Theodorou, Kiki; Kappas, Constantin; Zefkili, Sofia; Rosenwold, Jean-Claude
2004-01-01
It is well known that considerable underdosage can occur at the edges of a tumor inside the lung because of the degradation of penumbra due to lack of lateral electronic equilibrium. Although present even at smaller energies, this phenomenon is more pronounced for higher energies. Apart from Monte Carlo calculation, most of the existing Treatment Planning Systems (TPSs) cannot deal at all, or with acceptable accuracy, with this effect. A methodology has been developed for assessing the dose calculation algorithms in the lung region where lateral electronic disequilibrium exists, based on the Quality Index (QI) of the incident beam. A phantom, consisting of layers of polystyrene and lung material, has been irradiated using photon beams of 4, 6, 15, and 20 MV. The cross-plane profiles of each beam for 5x5, 10x10, and 25x10 fields have been measured at the middle of the phantom with the use of films. The penumbra (20%-80%) and fringe (50%-90%) enlargement was measured and the ratio of the widths for the lung to that of polystyrene was defined as the Correction Factor (CF). Monte Carlo calculations in the two phantoms have also been performed for energies of 6, 15, and 20 MV. Five commercial TPS's algorithms were tested for their ability to predict the penumbra and fringe enlargement. A linear relationship has been found between the QI of the beams and the CF of the penumbra and fringe enlargement for all the examined fields. Monte Carlo calculations agree very well (less than 1% difference) with the film measurements. The CF values range between 1.1 for 4 MV (QI 0.620) and 2.28 for 20 MV (QI 0.794). Three of the tested TPS's algorithms could not predict any enlargement at all for all energies and all fields and two of them could predict the penumbra enlargement to some extent. The proposed methodology can help any user or developer to check the accuracy of its algorithm for lung cases, based on a simple phantom geometry and the QI of the incident beam. This check is
A linearization of quantum channels
Crowder, Tanner
2015-06-01
Because the quantum channels form a compact, convex set, we can express any quantum channel as a convex combination of extremal channels. We give a Euclidean representation for the channels whose inverses are also valid channels; these are a subset of the extreme points. They form a compact, connected Lie group, and we calculate its Lie algebra. Lastly, we calculate a maximal torus for the group and provide a constructive approach to decomposing any invertible channel into a product of elementary channels.
Sasaki, Syota; Yamada, Tadashi; Yamada, Tomohito J.
2014-05-01
We aim to propose a kinematic-based methodology similar with runoff analysis for readily understandable radiological protection. A merit of this methodology is to produce sufficiently accurate effective doses by basic analysis. The great earthquake attacked the north-east area in Japan on March 11, 2011. The system of electrical facilities to control Fukushima Daiichi nuclear power plant was completely destroyed by the following tsunamis. From the damaged reactor containment vessels, an amount of radioactive isotopes had leaked and been diffused in the vicinity of the plant. Radiological internal exposure caused by ingestion of food containing radioactive isotopes has become an issue of great interest to the public, and has caused excessive anxiety because of a deficiency of fundamental knowledge concerning radioactivity. Concentrations of radioactivity in the human body and internal exposure have been studied extensively. Previous radiologic studies, for example, studies by International Commission on Radiological Protection(ICRP), employ a large-scale computational simulation including actual mechanism of metabolism in the human body. While computational simulation is a standard method for calculating exposure doses among radiology specialists, these methods, although exact, are too difficult for non-specialists to grasp the whole image owing to the sophistication. In this study, the human body is treated as a vessel. The number of radioactive atoms in the human body can be described by an equation of continuity, which is the only governing equation. Half-life, the period of time required for the amount of a substance decreases by half, is only parameter to calculate the number of radioactive isotopes in the human body. Half-life depends only on the kinds of nuclides, there are no arbitrary parameters. It is known that the number of radioactive isotopes decrease exponentially by radioactive decay (physical outflow). It is also known that radioactive isotopes
Directory of Open Access Journals (Sweden)
Melikhova Tetiana O.
2018-03-01
Full Text Available The aim of the article is to improve the methodological approaches to calculating the payback period for investment in order to determine the payback period for expenses on establishing the economic security service of an enterprise. It is found that the source of payback of investment at the enterprise level is cash flow product. These revenues (the result go to formation of a cash flow (expenses used to finance investment and financial activities. There proposed methods for determining the gross, net, actual, and specified payback periods for advanced investments in the long-term, which use the accumulated product of cash flow or accumulated cash flow as a source of financing. Analytic relationships between the gross, net, current, and specified payback periods for advanced investments that take into account the relationship between the accumulated gross, net, current and specified cash flows are proposed. The considered options for payback of advanced investment at the enterprise level will provide an opportunity to develop methods for determining the payback period for expenses on establishing the economic security service of an enterprise.
Energy Technology Data Exchange (ETDEWEB)
Vianna, E.A.L. [Centrais Eletricas do Norte (ELETRONORTE), Porto Velho, RO (Brazil)], E-mail: elainelimavianna@yahoo.com.br; Lambert-Torres, G.; Silva, L.E.B. da [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)], Emails: germanoltorres@gmail.com, leborges@unifei.edu.br; Rissino, S.; Silva, M.F. da [Universidade Federal de Rondonia (UFRO), Porto Velho, RO (Brazil)], Emails: srissino@gmail.com, felipe@unir.br
2009-07-01
Disturbances recorded in a electric power system compromise the quality and continuity energy supply and are measured by means of performance indicators. This article defines the attributes that contribute to increased the severity of disturbances recorded in an Electrical Power Transmission and proposes a methodology for calculating the degree of impact caused each of them. The proposed methodology allows quantification of the impact caused by a disturbance, and its comparison with other disturbance, in one system or distinct systems.
Energy Technology Data Exchange (ETDEWEB)
Gomes, Renato G.; Rebello, Wilson F.; Vellozo, Sergio O.; Moreira Junior, Luis, E-mail: renatoguedes@ime.eb.br, E-mail: rebello@ime.eb.br, E-mail: eng.cavaliere@gmail.com, E-mail: vellozo@cbpf.br, E-mail: luisjrmoreira@hotmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Vital, Helio C., E-mail: vital@ctex.eb.br [Centro Tecnologico do Exercito (CTEX), Barra de Guaratiba, RJ (Brazil); Rusin, Tiago, E-mail: tiago.rusin@mma.gov.br [Ministerio do Meio Ambiente (MMA), Brasilia, DF (Brazil); Silva, Ademir X., E-mail: ademir@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)
2013-07-01
In order to evaluate new lines of research in the area of irradiation of materials external to the research irradiating facility Army Technology Center (CTEx), it is necessary to study security parameters and magnitude of the dose rates from their channels of escape. The objective was to calculate, with the code MCNPX, dose rates (Gy / min) on the interior and exterior of the four-channel leakage gamma irradiator. The channels were designed to leak radiation on materials properly disposed in the area outside the irradiator larger than the expected volume of irradiation chambers (50 liters). This study aims to assess the magnitude of dose rates within the channels, as well as calculate the angle of beam output range outside the channel for analysis as to its spread, and evaluation of safe conditions of their operators (protection radiological). The computer simulation was performed by distributing virtual dosimeter ferrous sulfate (Fricke) in the longitudinal axis of the vertical drain channels (anterior and posterior) and horizontal (top and bottom). The results showed a collimating the beams irradiated on each of the channels to the outside, with values of the order of tenths of Gy / min as compared to the maximum amount of operation of the irradiator chamber (33 Gy / min). The external beam irradiation in two vertical channels showed a distribution shaped 'trunk pyramid', not collimated, so scattered, opening angle 83 ° in the longitudinal direction and 88 in the transverse direction. Thus, the cases allowed the evaluation of materials for irradiation outside the radiator in terms of the magnitude of the dose rates and positioning of materials, and still be able to take the necessary care in mounting shield for radiation protection by operators, avoiding exposure to ionizing radiation. (author)
Bai, Qifeng; Pérez-Sánchez, Horacio; Zhang, Yang; Shao, Yonghua; Shi, Danfeng; Liu, Huanxiang; Yao, Xiaojun
2014-08-14
The reported crystal structures of β2 adrenergic receptor (β2AR) reveal that the open and closed states of the water channel are correlated with the inactive and active conformations of β2AR. However, more details about the process by which the water channel states are affected by the active to inactive conformational change of β2AR remain illusive. In this work, molecular dynamics simulations are performed to study the dynamical inactive and active conformational change of β2AR induced by inverse agonist ICI 118,551. Markov state model analysis and free energy calculation are employed to explore the open and close states of the water channel. The simulation results show that inverse agonist ICI 118,551 can induce water channel opening during the conformational transition of β2AR. Markov state model (MSM) analysis proves that the energy contour can be divided into seven states. States S1, S2 and S5, which represent the active conformation of β2AR, show that the water channel is in the closed state, while states S4 and S6, which correspond to the intermediate state conformation of β2AR, indicate the water channel opens gradually. State S7, which represents the inactive structure of β2AR, corresponds to the full open state of the water channel. The opening mechanism of the water channel is involved in the ligand-induced conformational change of β2AR. These results can provide useful information for understanding the opening mechanism of the water channel and will be useful for the rational design of potent inverse agonists of β2AR.
Directory of Open Access Journals (Sweden)
Marcos A. Golato
2008-07-01
based on the resolution of matter and energy balances for each of the system components. This methodology can be applied to steam generators using bagasse, natural gas or both (as a blend as fuels. Examples of thermal efficiency calculations, using data from several experimental tests on steam generators where each type of fuel processing occurs, are presented. The resolution of matter and energy balances in a boiler fired by bagasse gave a thermal efficiency of 53.2% and a rate of 1.38 kg of steam/ kg of bagasse. For a boiler fired by natural gas, a thermal efficiency of 76.7% and an index of 9.8 kg of steam/ Nm³ of natural gas, were obtained. For a boiler fired simultaneously by bagasse and natural gas, a yield of 68.3% and an index of 1.87 kg of steam/ kg of equivalent bagasse were recorded. To validate this methodology, these values were contrasted with the efficiency values obtained in accordance with the American Society of Mechanical Engineers (ASME code.
International Nuclear Information System (INIS)
Rojo, Ana M.; Gomez Parada, Ines
2004-01-01
The MIRD (Medical Internal Radiation Dose) system was established by the Society of Nuclear Medicine of USA in 1960 to assist the medical community in the estimation of the dose in organs and tissues due to the incorporation of radioactive materials. Since then, 'MIRD Dose Estimate Report' (from the 1 to 12) and 'Pamphlets', of great utility for the dose calculations, were published. The MIRD system was planned essentially for the calculation of doses received by the patients during nuclear medicine diagnostic procedures. The MIRD methodology for the absorbed doses calculations in different tissues is explained
Mui, D. S. L.; Patil, M. B.; Morkoc, H.
1989-01-01
Three double-heterojunction modulation-doped field-effect transistor structures with different channel composition are investigated theoretically. All of these transistors have an In(x)Ga(1-x)As channel sandwiched between two doped Al(0.3)Ga(0.7)As barriers with undoped spacer layers. In one of the structures, x varies from 0 from either heterojunction to 0.15 at the center of the channel quadratically; in the other two, constant values of x of 0 and 0.15 are used. The Poisson and Schroedinger equations are solved self-consistently for the electron wave function in all three cases. The results showed that the two-dimensional electron gas (2DEG) concentration in the channel of the quadratically graded structure is higher than the x = 0 one and slightly lower than the x = 0.15 one, and the mean distance of the 2DEG is closer to the center of the channel for this transistor than the other two. These two effects have important implications on the electron mobility in the channel.
Directory of Open Access Journals (Sweden)
Vvedensky Alexei Rostislavovich
2017-05-01
Full Text Available The estimation of changes in the ecological situation and bottom topography in the Ob Bay, which may be caused by the construction of the approach channel to the port of Sabetta, was carried out with the help of the developed complex of numerical models. Particular attention was paid to the study of the displacement of the boundaries of the saline water expansion and the sediment accumulation in the channel area. It is established that the possible influence of the approach channel on the hydrologic-hydrochemical characteristics is less than their natural interannual and seasonal variability in the investigated water area. The change in the bottom topography after the construction of the approach channel does not entail a significant change in the regime of hydrologic-hydrochemical parameters of the Ob Bay and, consequently, should not affect the biocenosis. The calculated changes in the bottom topography in the approach channel area will not exceed 2 % of the depth per year and will not become a significant obstacle to the reliable and uninterrupted operation of the Sabetta port.
Kostyuk, A. G.; Karpunin, A. P.
2016-01-01
This article describes a high accuracy method enabling performance of the calculation of real values of the initial temperature of a gas turbine unit (GTU), i.e., the gas temperature at the outlet of the combustion chamber, in a situation where manufacturers do not disclose this information. The features of the definition of the initial temperature of the GTU according to ISO standards were analyzed. It is noted that the true temperatures for high-temperature GTUs is significantly higher than values determined according to ISO standards. A computational procedure for the determination of gas temperatures in the air-gas channel of the gas turbine and cooling air consumptions over blade rims is proposed. As starting equations, the heat balance equation and the flow mixing equation for the combustion chamber are assumed. Results of acceptance GTU tests according to ISO standards and statistical dependencies of required cooling air consumptions on the gas temperature and the blade metal are also used for calculations. An example of the calculation is given for one of the units. Using a developed computer program, the temperatures in the air-gas channel of certain GTUs are calculated, taking into account their design features. These calculations are performed on the previously published procedure for the detailed calculation of the cooled gas turbine subject to additional losses arising because of the presence of the cooling system. The accuracy of calculations by the computer program is confirmed by conducting verification calculations for the GTU of the Mitsubishi Comp. and comparing results with published data of the company. Calculation data for temperatures were compared with the experimental data and the characteristics of the GTU, and the error of the proposed method is estimated.
International Nuclear Information System (INIS)
Li, D.
1980-01-01
Reviewed is the effect of heat flux of different system parameters on critical density in order to give an initial view on the value of several parameters. A thorough analysis of different equations is carried out to calculate burnout is steam-water flows in uniformly heated tubes, annular, and rectangular channels and rod bundles. Effect of heat flux density distribution and flux twisting on burnout and storage determination according to burnout are commended [ru
Energy Technology Data Exchange (ETDEWEB)
Santos, Rubens Souza dos [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil); Martinez, Aquilino Senra; Alvim, Antonio Carlos Marques [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear
2002-07-01
In this work is presented a methodology which focuses the distribution of neutron absorber rods in nuclear reactor power plants, for utilizing in space kinetic calculations, principally in the cluster ejection transients of control rods. A numerical model for macroscopic constant calculations based on the knowledge of the neutron flux without the control rods is proposed, as alternative to the analytical models, based on the hypothesis of the null current on the cell super boundaries. The proposed model in this work has itself showed adequate to deal with problems with strong space dependence, once that the model showed consistence in the global average built in the analytical model. (author)
International Nuclear Information System (INIS)
Gomez-Magan, J. J.; Fernandez, I.; Gil, J.; Marrao, H.; Queral, C.; Gonzalez-Cadelo, J.; Montero-Mayorga, J.; Rivas, J.; Ibane-Llano, C.; Izquierdo, J. M.; Sanchez-Perea, M.; Melendez, E.; Hortal, J.
2013-01-01
The Integrated Safety Analysis (ISA) methodology, developed by the Spanish Nuclear Safety council (CSN), has been applied to obtain the dynamic Event Trees (DETs) for full spectrum Loss of Coolant Accidents (LOCAs) of a Westinghouse 3-loop PWR plant. The purpose of this ISA application is to obtain the Damage Excedence Frequency (DEF) for the LOCA Event Tree by taking into account the uncertainties in the break area and the operator actuation time needed to cool down and de pressurize reactor coolant system by means of steam generator. Simulations are performed with SCAIS, a software tool which includes a dynamic coupling with MAAP thermal hydraulic code. The results show the capability of the ISA methodology to obtain the DEF taking into account the time uncertainty in human actions. (Author)
International Nuclear Information System (INIS)
Stefani, Giovanni Laranjo de; Conti, Thadeu das Neves; Fedorenko, Giuliana G.; Castro, Vinicius A.; Maio, Mireia F.; Santos, Thiago Augusto dos
2011-01-01
This work objective was to create a manager program that would automate the programs and computer codes in use for neutronic calculation and thermo-hydraulic in IEA-R1 reactor thus making the process for calculation of safety parameters and for configuration change up to 98% faster than that used in the reactor today. This process was tested in combination with the reactor operators and is being implemented by the quality department. The main codes and programs involved in the calculations of configuration change are Leopard, Hammier-Technion, Twodb, Citation and Cobra. Calculations of delayed neutron and criticality coefficients given in the process of safety parameters calculation are given by the Hammer-Technion and Citation in a process that involves about eleven repetitions so that it meets all the necessary conditions (such different temperatures of the moderator and fuel). The results are entirely consistent with the expected and absolutely the same as those given by manual process. Thus the work shows its reliability as well the advantage of saving time, once a process that could take up to four hours was turned in one that takes around five minutes when done in a home computer. Much of this advantage is due to the fact that were created subprograms to treat the output of each program used and transform them into the input of the other programs, removing from it the intermediate essential data for this to occur, thus avoiding also a possible human error by handling the various data supplied. (author)
International Nuclear Information System (INIS)
Halsnaes, K.; Callaway, J.M.; Meyer, H.J.
1999-01-01
The guideline document establishes a general overview of the main components of climate change mitigation assessment. This includes an outline of key economic concepts, scenario structure, common assumptions, modelling tools and country study assumptions. The guidelines are supported by Handbook Reports that contain more detailed specifications of calculation standards, input assumptions and available tools. The major objectives of the project have been provided a methodology, an implementing framework and a reporting system which countries can follow in meeting their future reporting obligations under the FCCC and for GEF enabling activities. The project builds upon the methodology development and application in the UNEP National Abatement Coasting Studies (UNEP, 1994a). The various elements provide countries with a road map for conducting climate change mitigation studies and submitting national reports as required by the FCCC. (au) 121 refs
Energy Technology Data Exchange (ETDEWEB)
Halsnaes, K.; Callaway, J.M.; Meyer, H.J.
1999-04-01
The guideline document establishes a general overview of the main components of climate change mitigation assessment. This includes an outline of key economic concepts, scenario structure, common assumptions, modelling tools and country study assumptions. The guidelines are supported by Handbook Reports that contain more detailed specifications of calculation standards, input assumptions and available tools. The major objectives of the project have been provided a methodology, an implementing framework and a reporting system which countries can follow in meeting their future reporting obligations under the FCCC and for GEF enabling activities. The project builds upon the methodology development and application in the UNEP National Abatement Coasting Studies (UNEP, 1994a). The various elements provide countries with a road map for conducting climate change mitigation studies and submitting national reports as required by the FCCC. (au) 121 refs.
Energy Technology Data Exchange (ETDEWEB)
Jaeger, Wadim; Manes, Jorge Perez; Imke, Uwe; Escalante, Javier Jimenez; Espinoza, Victor Sanchez, E-mail: victor.sanchez@kit.edu
2013-10-15
Highlights: • Simulation of BFBT turbine and pump transients at multiple scales. • CFD, sub-channel and system codes are used for the comparative study. • Heat transfer models are compared to identify difference between the code predictions. • All three scales predict results in good agreement to experiment. • Sub cooled boiling models are identified as field for future research. -- Abstract: The Institute for Neutron Physics and Reactor Technology (INR) at the Karlsruhe Institute of Technology (KIT) is involved in the validation and qualification of modern thermo hydraulic simulations tools at various scales. In the present paper, the prediction capabilities of four codes from three different scales – NEPTUNE{sub C}FD as fine mesh computational fluid dynamics code, SUBCHANFLOW and COBRA-TF as sub channels codes and TRACE as system code – are assessed with respect to their two-phase flow modeling capabilities. The subject of the investigations is the well-known and widely used data base provided within the NUPEC BFBT benchmark related to BWRs. Void fraction measurements simulating a turbine and a re-circulation pump trip are provided at several axial levels of the bundle. The prediction capabilities of the codes for transient conditions with various combinations of boundary conditions are validated by comparing the code predictions with the experimental data. In addition, the physical models of the different codes are described and compared to each other in order to explain the different results and to identify areas for further improvements.
International Nuclear Information System (INIS)
Shevenell, L.; Hoffman, F.O.; MacIntosh, D.
1992-03-01
The Waste Area Groupings (WAGs) at the Oak Ridge National Laboratory (ORNL) were reranked with respect to on- and off-site human health risks using two different methods. Risks associated with selected contaminants from each WAG for occupants of WAG 2 or an off-site area were calculated using a modified formulation of the Multimedia Environmental Pollutant Assessment System (MEPAS) and a method suitable for screening, referred to as the ORNL/ESD method (the method developed by the Environmental Sciences Division at ORNL) in this report. Each method resulted in a different ranking of the WAGs. The rankings from the two methods are compared in this report. All risk assessment calculations, except the original MEPAS calculations, indicated that WAGs 1; 2, 6, 7 (WAGs 2, 6 and 7 as one combined WAG); and 4 pose the greatest potential threat to human health. However, the overall rankings of the WAGs using constant parameter values in the different methods were inconclusive because uncertainty in parameter values can change the calculated risk associated with particular pathways, and hence, the final rankings. Uncertainty analysis using uncertainties about all model parameters were used to reduce biases associated with parameter selection and to more reliably rank waste sites according to potential risks associated with site contaminants. Uncertainty analysis indicates that the WAGs should be considered for further investigation, or remediation, in the following order: (1) WAG 1; (2) WAGs 2, 6, and 7 (combined); and 4; (3) WAGs 3, 5, and 9; and, (4) WAG 8
Energy Technology Data Exchange (ETDEWEB)
Te Buck, S.; Van Keulen, B.; Bosselaar, L.; Gerlagh, T.; Skelton, T.
2010-07-15
This is the fifth, updated edition of the Dutch Renewable Energy Monitoring Protocol. The protocol, compiled on behalf of the Ministry of Economic Affairs, can be considered as a policy document that provides a uniform calculation method for determining the amount of energy produced in the Netherlands in a renewable manner. Because all governments and organisations use the calculation methods described in this protocol, this makes it possible to monitor developments in this field well and consistently. The introduction of this protocol outlines the history and describes its set-up, validity and relationship with other similar documents and agreements. The Dutch Renewable Energy Monitoring Protocol is compiled by NL Agency, and all relevant parties were given the chance to provide input. This has been incorporated as far as is possible. Statistics Netherlands (CBS) uses this protocol to calculate the amount of renewable energy produced in the Netherlands. These data are then used by the Ministry of Economic Affairs to gauge the realisation of policy objectives. In June 2009 the European Directive for energy from renewable sources was published with renewable energy targets for the Netherlands. This directive used a different calculation method - the gross energy end-use method - whilst the Dutch definition is based on the so-called substitution method. NL Agency was asked to add the calculation according to the gross end use method, although this is not clearly defined on a number of points. In describing the method, the unanswered questions become clear, as do, for example, the points the Netherlands should bring up in international discussions.
Directory of Open Access Journals (Sweden)
Ebtehaj Isa
2016-09-01
Full Text Available A vital topic regarding the optimum and economical design of rigid boundary open channels such as sewers and drainage systems is determining the movement of sediment particles. In this study, the incipient motion of sediment is estimated using three datasets from literature, including a wide range of hydraulic parameters. Because existing equations do not consider the effect of sediment bed thickness on incipient motion estimation, this parameter is applied in this study along with the multilayer perceptron (MLP, a hybrid method based on decision trees (DT (MLP-DT, to estimate incipient motion. According to a comparison with the observed experimental outcome, the proposed method performs well (MARE = 0.048, RMSE = 0.134, SI = 0.06, BIAS = -0.036. The performance of MLP and MLP-DT is compared with that of existing regression-based equations, and significantly higher performance over existing models is observed. Finally, an explicit expression for practical engineering is also provided.
Directory of Open Access Journals (Sweden)
Pavol Partila
2013-01-01
Full Text Available This article discusses a methodology for rating the quality of mobile calls. Majority telecommunications service from the perspective of the whole world is using mobile telephony networks. One of the problems affecting this service and its quality are landscape barriers, which prevent the spread signal. Price and complex construction of classic BTS does not allow their dense distribution. In such cases, one solution is to use OpenBTS technology. Design of OpenBTS is more available, so it can be applied to much more places and more complex points. Purpose of this measurement is a model for effective stations deployment, due to shape and distribution of local barriers that reduce signal power, and thus the quality of speech. GSM access point for our mobile terminals is OpenBTS USRP N210 station. The PESQ method for evaluating of speech quality is compared with the subjective evaluation, which provides Asterisk PBX with IVR call back. Measurement method was taken into account the call quality depending on terminal position. The measured results and its processing bring knowledge to use this technology for more complicated locations with degraded signal level and increases the quality of voice services in telecommunications.
International Nuclear Information System (INIS)
Smith, R.E.; Waisman, R.; Hu, M.H.; Frick, T.M.
1995-01-01
A non-linear analysis has been performed to determine relative motions between tubes and tube support plates (TSP) during a steam line break (SLB) event for steam generators. The SLB event results in blowdown of steam and water out of the steam generator. The fluid blowdown generates pressure drops across the TSPS, resulting in out-of-plane motion. The SLB induced pressure loads are calculated with a computer program that uses a drift-flux modeling of the two-phase flow. In order to determine the relative tube/TSP motions, a nonlinear dynamic time-history analysis is performed using a structural model that considers all of the significant component members relative to the tube support system. The dynamic response of the structure to the pressure loads is calculated using a special purpose computer program. This program links the various substructures at common degrees of freedom into a combined mass and stiffness matrix. The program accounts for structural non-linearities, including potential tube and TSP interaction at any given tube position. The program also accounts for structural damping as part of the dynamic response. Incorporating all of the above effects, the equations of motion are solved to give TSP displacements at the reduced set of DOF. Using the displacement results from the dynamic analysis, plate stresses are then calculated using the detailed component models. Displacements form the dynamic analysis are imposed as boundary conditions at the DOF locations, and the finite element program then solves for the overall distorted geometry. Calculations are also performed to assure that assumptions regarding elastic response of the various structural members and support points are valid
International Nuclear Information System (INIS)
Song, Myung Sub; Kim, Song Hyun; Kim, Jong Kyung; Noh, Jae Man
2014-01-01
The uncertainty with the sampling-based method is evaluated by repeating transport calculations with a number of cross section data sampled from the covariance uncertainty data. In the transport calculation with the sampling-based method, the transport equation is not modified; therefore, all uncertainties of the responses such as k eff , reaction rates, flux and power distribution can be directly obtained all at one time without code modification. However, a major drawback with the sampling-based method is that it requires expensive computational load for statistically reliable results (inside confidence level 0.95) in the uncertainty analysis. The purpose of this study is to develop a method for improving the computational efficiency and obtaining highly reliable uncertainty result in using the sampling-based method with Monte Carlo simulation. The proposed method is a method to reduce the convergence time of the response uncertainty by using the multiple sets of sampled group cross sections in a single Monte Carlo simulation. The proposed method was verified by estimating GODIVA benchmark problem and the results were compared with that of conventional sampling-based method. In this study, sampling-based method based on central limit theorem is proposed to improve calculation efficiency by reducing the number of repetitive Monte Carlo transport calculation required to obtain reliable uncertainty analysis results. Each set of sampled group cross sections is assigned to each active cycle group in a single Monte Carlo simulation. The criticality uncertainty for the GODIVA problem is evaluated by the proposed and previous method. The results show that the proposed sampling-based method can efficiently decrease the number of Monte Carlo simulation required for evaluate uncertainty of k eff . It is expected that the proposed method will improve computational efficiency of uncertainty analysis with sampling-based method
Martens, Kyle D.; Fish, Teresa M.; Watson, Grace A.; Connolly, Patrick J.
2014-01-01
, leaving one large pool near the bottom of the side channel and several shallow isolated pools that may or may not go dry. In seasonally connected side channels, juvenile salmonid survival in pools less than 100 cm average depth was lower than in pools greater than 100 cm average depth (Martens and Connolly, 2014). In this report, we document our field work and analysis completed in 2013. During 2013, USGS sampling efforts were focused on resampling of three reaches in Beaver Creek, testing methodology in the Whitefish Island side channel, conducting hatchery survival estimates, and operating a screw trap on the Chewuch River (funded by Yakama Nation; fig. 1). The Beaver Creek sampling effort was a revisit of three index sites sampled continuously from 2004 to 2007 to look at the fish response to barrier removal. Methodology testing in Whitefish Island side channel was done to determine the best method for evaluating fish populations after restoration efforts in side channels (previous sampling methods were determined to be ineffective after pools were deepened). Hatchery survival estimates were completed to monitor fish survival in the Methow and Columbia Rivers, while the screw trap was operated to estimate migrating fish populations in the Chewuch River and track passive integrated transponder (PIT)-tagged fish. In addition, we maintained a network of PIT-tag interrogation systems (PTIS), assisted Reclamation with fish removal events associated with stream restoration (two people for 9 days; 14 percent of summer field season), and conducted a stream metabolism study designed to help parameterize and calibrate the stream productivity model (Bellmore and others, 2014) with model validation.
Lee, A. Y.
1967-01-01
Computer program calculates the steady state fluid distribution, temperature rise, and pressure drop of a coolant, the material temperature distribution of a heat generating solid, and the heat flux distributions at the fluid-solid interfaces. It performs the necessary iterations automatically within the computer, in one machine run.
International Nuclear Information System (INIS)
Blanchet, D.
2006-01-01
The objective of this work is to develop the modelling of the nuclear heating of the experimental devices of the future Jules Horowitz material testing reactor (RJH). The strong specific nuclear power produced (460 kW/l), induces so intense photonic fluxes which cause heating and large temperature gradients that it is necessary to control it by an adequate design. However, calculations of heating are penalized by the very large uncertainties estimated at a value of about 30% (2*σ) coming from the gaps and uncertainties of the data of gamma emission present in the libraries of basic nuclear data. The experimental program ADAPh aims at reducing these uncertainties. Measurements by thermoluminescent detectors (TLD) and ionisation chambers are carried out in the critical assemblies EOLE (Mox) and Minerve (UO 2 ). The rigorous interpretation of these measurements requires specific developments based on Monte-Carlo simulations of coupled neutron-gamma and gamma-electron transport. The developments carried out are made different in particular by the modelling of cavities phenomena and delayed gamma emissions by the decay of fission products. The comparisons calculation-measurement made it possible to identify a systematic bias confirming a tendency of calculations to underestimate measurements. A Bayesian method of adjustment was developed in order to re-estimate the principal components of the gamma heating and to transpose the results obtained to the devices of the RJH, under conditions clearly and definitely representative. This work made possible to reduce significantly the uncertainties on the determination of the gamma heating from 30 to 15 per cent. (author)
Uneconomical top calculation method
International Nuclear Information System (INIS)
De Noord, M.; Vanm Sambeek, E.J.W.
2003-08-01
The methodology used to calculate the financial gap of renewable electricity sources and technologies is described. This methodology is used for calculating the production subsidy levels (MEP subsidies) for new renewable electricity projects in 2004 and 2005 in the Netherlands [nl
Energy Technology Data Exchange (ETDEWEB)
Weissglas, P [The Swedish State Power Board, Stockholm (Sweden)
1960-11-15
The purpose of the present study was to evaluate theoretically the effect of coolant boiling and subsequent void formation in a pressurized D{sub 2}O moderated and cooled reactor. The fuel rods were arranged in a cluster geometry and clad in Zr-2. The coolant was separated from the moderator by a Zr-2 shroud. In this geometry the following problems have been given special attention: l) calculation of the effective resonance integral, 2) thermal disadvantage factors, 3) fast fission effects, 4) leakage effects, 5) changes in epithermal absorption. No account has up to now been taken of the variation of these effects with position in the reactor and burnup. Some comparisons of the theoretical methods and measurements have been attempted. It is concluded that at the present time it is not possible to calculate the void coefficient with any accuracy but it may be possible to give an upper limit from theoretical consideration.
International Nuclear Information System (INIS)
Bogatyrev, I.L.; Bogoslovskaya, G.P.; Zhukov, A.V.; Sorokin, A.P.; Titov, P.A.
1992-01-01
System of constants for mass, impulse and energy conservation equations (drag, mixing, heat transfer coefficients, azimuthal unquality of temperature) is reported in region with small Re number for wide range of geometrical assembly parameters. This system can be used in subchannel calculations of assemblies with natural and mixed convection under conditions with loss of flow accident. The formulae are compared with experimental data. 30 refs.; 12 figs.; 1 tab
Using frequency equivalency in stability calculations
Energy Technology Data Exchange (ETDEWEB)
Gruzdev, I.A.; Temirbulatov, R.A.; Tereshko, L.A.
1981-01-01
A methodology for calculating oscillatory instability that involves using frequency equivalency is employed in carrying out the following proceedures: dividing an electric power system into subgroups; determining the adjustments to the automatic excitation control in each subsystem; simplifying the mathematical definition of the separate subsystems by using frequency equivalency; gradually re-tuning the automatic excitation control in the separate subsystems to account for neighboring subsystems by using their equivalent frequency characteristics. The methodology is to be used with a computer program to determine the gain in the stabilization channels of the automatic excitation control unit in which static stability of the entire aggregate of normal and post-breakdown conditions acceptable damping of transient processes are provided. The possibility of reducing the equation series to apply to chosen regions of the existing range of frequencies is demonstrated. The use of the methodology is illustrated in a sample study on stability in a Siberian unified power system.
International Nuclear Information System (INIS)
Farah, Jad
2011-01-01
To optimize the monitoring of female workers using in vivo spectrometry measurements, it is necessary to correct the typical calibration coefficients obtained with the Livermore male physical phantom. To do so, numerical calibrations based on the use of Monte Carlo simulations combined with anthropomorphic 3D phantoms were used. Such computational calibrations require on the one hand the development of representative female phantoms of different size and morphologies and on the other hand rapid and reliable Monte Carlo calculations. A library of female torso models was hence developed by fitting the weight of internal organs and breasts according to the body height and to relevant plastic surgery recommendations. This library was next used to realize a numerical calibration of the AREVA NC La Hague in vivo counting installation. Moreover, the morphology-induced counting efficiency variations with energy were put into equation and recommendations were given to correct the typical calibration coefficients for any monitored female worker as a function of body height and breast size. Meanwhile, variance reduction techniques and geometry simplification operations were considered to accelerate simulations. Furthermore, to determine the activity mapping in the case of complex contaminations, a method that combines Monte Carlo simulations with in vivo measurements was developed. This method consists of realizing several spectrometry measurements with different detector positioning. Next, the contribution of each contaminated organ to the count is assessed from Monte Carlo calculations. The in vivo measurements realized at LEDI, CIEMAT and KIT have demonstrated the effectiveness of the method and highlighted the valuable contribution of Monte Carlo simulations for a more detailed analysis of spectrometry measurements. Thus, a more precise estimate of the activity distribution is given in the case of an internal contamination. (author)
Energy Technology Data Exchange (ETDEWEB)
Oliveira, A.C.J.G. de
1988-12-01
Sensitivity calculations are very important in design and safety of nuclear reactor cores. Large codes with a great number of physical considerations have been used to perform sensitivity studies. However, these codes need long computation time involving high costs. The perturbation theory has constituted an efficient and economical method to perform sensitivity analysis. The present work is an application of the perturbation theory (matricial formalism) to a simplified model of DNB (Departure from Nucleate Boiling) analysis to perform sensitivity calculations in PWR cores. Expressions to calculate the sensitivity coefficients of enthalpy and coolant velocity with respect to coolant density and hot channel area were developed from the proposed model. The CASNUR.FOR code to evaluate these sensitivity coefficients was written in Fortran. The comparison between results obtained from the matricial formalism of perturbation theory with those obtained directly from the proposed model makes evident the efficiency and potentiality of this perturbation method for nuclear reactor cores sensitivity calculations (author). 23 refs, 4 figs, 7 tabs.
Electron transfer in keV Li+-Na(3s, 3p) collisions: I. Atomic basis coupled-channel calculations
International Nuclear Information System (INIS)
Nielsen, S.E.; Dubois, A.
1995-01-01
Integral cross sections for electron capture from the ground state Na(3s) and excited states Na(3p) to Li(nlm), n = 2, 3, are calculated by the semiclassical impact-parameter method, using a two-centre atomic basis expansion. In the impact energy range 1-50 keV, results are analysed with particular emphasis on the alignment and orientation of initial and final p-states. At intermediate velocities opposite initial alignment effects are found for capture to n = 2 and n = 3 states, respectively. Orientation effects in state-to-state capture cross sections are predicted from oriented and tilted aligned initial states. (Author)
International Nuclear Information System (INIS)
Chaudhury, Sanhita; Agarwal, Chhavi; Goswami, A.; Mhatre, Amol; Chaturvedi, T.P.; Tawde, N.; Gathibandhe, Manohar; Dash, S.C.
2011-05-01
Radioactivity measurement using CdZnTe detector and dose measurement using teletector were done at several locations of primary heat transport (PHT) system of the Tarapur Atomic Power Station-III and IV reactor during shut down as well as operating condition of the reactors. The detector efficiency for the required counting geometry was simulated using MCNP code. Using this simulated efficiency and the experimental count rate (cps), the activity concentrations (Bq/mL) of different radionuclides in coolant water were calculated. The dose rates for the counted locations were also simulated using Monte Carlo code and it matched well with the experimentally obtained dose rate. (author)
Free-Energy Calculations. A Mathematical Perspective
Pohorille, Andrzej
2015-01-01
Ion channels are pore-forming assemblies of transmembrane proteins that mediate and regulate ion transport through cell walls. They are ubiquitous to all life forms. In humans and other higher organisms they play the central role in conducting nerve impulses. They are also essential to cardiac processes, muscle contraction and epithelial transport. Ion channels from lower organisms can act as toxins or antimicrobial agents, and in a number of cases are involved in infectious diseases. Because of their important and diverse biological functions they are frequent targets of drug action. Also, simple natural or synthetic channels find numerous applications in biotechnology. For these reasons, studies of ion channels are at the forefront of biophysics, structural biology and cellular biology. In the last decade, the increased availability of X-ray structures has greatly advanced our understanding of ion channels. However, their mechanism of action remains elusive. This is because, in order to assist controlled ion transport, ion channels are dynamic by nature, but X-ray crystallography captures the channel in a single, sometimes non-native state. To explain how ion channels work, X-ray structures have to be supplemented with dynamic information. In principle, molecular dynamics (MD) simulations can aid in providing this information, as this is precisely what MD has been designed to do. However, MD simulations suffer from their own problems, such as inability to access sufficiently long time scales or limited accuracy of force fields. To assess the reliability of MD simulations it is only natural to turn to the main function of channels - conducting ions - and compare calculated ionic conductance with electrophysiological data, mainly single channel recordings, obtained under similar conditions. If this comparison is satisfactory it would greatly increase our confidence that both the structures and our computational methodologies are sufficiently accurate. Channel
International Nuclear Information System (INIS)
Kadecka, P.
1995-01-01
The problem of evaluation of tolerable defects and thinning of pipe walls was analyzed. In fact, a procedure for evaluation of tolerable defects is described in ASME Code Case N 480 based on the ASME ''Rules for Construction of Nuclear Power Plant Components''. The pipe systems of the Dukovany NPP, however, were constructed to different (East European) standards, and therefore caution should be exercised when applying US standards to this plant. The report demonstrates major differences between the ASME Standard and the proposed Czech standard ''A.S.I. Standards Documentation for Strength Calculations of Equipment and Piping of WWER Type Nuclear Power Plants'' developed by the Czech Association of Mechanical Engineers (A.S.I), evaluates the applicability of Code Case N 480 to the Dukovany plant, and proposes a Czech procedure for the evaluation. The basic characteristics of materials cited by ASME II and carbon steels used in the secondary circuit of the Dukovany NPP are also compared. (P.A.). 78 tabs., 2 figs., 4 refs
International Nuclear Information System (INIS)
Sweeton, F.H.
1975-09-01
The CUEX (Cumulative Exposure Index) relates the concentrations of various nuclides in the environment to assigned annual dose limits. A computer code has been written to calculate this index for stack releases of radioactivity. This report is written to illustrate how the code in its present form can be applied to a particular reactor. The data used here are from the Haddam Neck (Connecticut Yankee) Nuclear Power Plant, a relatively large plant that has been in operation for 6 years. The results show that the highest exposure expected from the actual releases of gaseous 85 Kr, 133 Xe, 131 I, and 3 H is about 0.2 percent of the as low as practicable limits set by the Nuclear Regulatory Commission. Of the nuclides considered, 133 Xe is by far the most important; the chief mode of exposure to this nuclide is submersion in air. In the case of 131 I the main exposure route is external irradiation from the activity on the ground except for the special case of the thyroid for which about 70 per []ent of the exposure arises from ingestion. (auth)
Energy Technology Data Exchange (ETDEWEB)
Jimbert, P.; Guraya, T.; Torregary, A.; Bravo, P.
2013-06-01
To achieve the mechanical properties and corrosion resistance desired by duplex stainless steels used by the petrochemical and nuclear industry, parts are subjected to a hiperquenching heat treatment from about 1050 degree centigrade. This avoids the risk of intermetallic precipitation which drastically reduces the properties of these materials. However with increasing depth to which the deposits are present, the thicknesses for such pipes have been increased, resulting in higher levels of demand on all its manufacturing process, including the heat treatment. To avoid the precipitation of intermetallic phases such as sigma phase it is necessary to know the cooling profile in the center of the work piece and for this purpose to know the value of the Surface Heat Transfer Coefficient (h) is essential. This coefficient changes during the hiperquenching and its value is determined experimentally as it depends on several process parameters. Studies reveal that its value is stabilized within a few seconds. We can then assume that to know the cooling profile in the center of large sections it is only necessary to know the stabilized value of h. However, all the studies found in the literature are referred to diameters smaller than 100 mm. This paper has developed a methodology to predict the precipitation of intermetallic phases in duplex stainless steel parts with large thicknesses in industrial facilities from the calculation of h. This methodology allows us to calculate the cooling profiles without wasting any work piece using one or more sensorized patterns with thermocouples and a subsequent simulation with ANSYS. (Author)
Energy Technology Data Exchange (ETDEWEB)
Rosenqvist, Haakan
2010-02-15
There are two main objectives to this report. The first is to describe a calculation method for both short- and long-term analysis of crops, as well as present the basis and reasoning around it. Another objective is to create an approach that lay-people can use to compare energy crops with traditional crops in a sufficiently straight-forward and believable manner. The report describes, discusses and develops the technical aspects to the calculation questions around the analysis of crops that are grown only on small area of land today, but have the potential to be grown on much larger areas in the future. The variable costing calculation approach is used in agriculture as decision-support for what should be produced. The present variable costing calculation approach has been reworked and redeveloped in order to be more applicable as a decision-support tool. This includes its use to decide which crop should be grown in both short- and long-term perspectives, as well as for perennial energy crops. A number of items that impact growing economy and how they can be interpreted in the growing calculations are discussed. Some of the examples are: Fertilization effects; Sales commissions/product prices; Storage/reestablishment; Fertilization of P and K; Crop insurance; Labor costs; Machine costs; Timeliness costs; New production chains and unutilized resources; Interest rates; Land costs; Over overhead costs; and Costs which not are annual. The main objective of this report is a methodological question and not to show the absolute profitability for each particular land use alternative. But even though the calculations have been improved for different land uses, there is material that that can even be used for profitability analyses. This has been performed to a smaller degree in this report. The profitability of Salix growing has been studied for a variety of different conditions. For part of the studies have used the entire growing period of 22 years, part with
Energy Technology Data Exchange (ETDEWEB)
Nikolic, M; Strugar, P; Mitrovic, S [Institute of Nuclear Sciences Boris Kidric, Reaktor RA, Vinca, Beograd (Serbia and Montenegro)
1964-12-15
Upon demand of the Laboratory for fuel reprocessing, six domestic metal uranium pellets were exposed to neutron flux ( 4 - 5 10{sup 12} n cm{sup -2} sec {sup -1}) in the RA reactor. Irradiation of fuel demanded special analyses for safety reasons. Weight of the fuel pellets was 13 - 20 g, having diameter 20 mm. pellets were placed in leak tight aluminium capsules with helium. The irradiation was dome in the aluminium experimental channel in the graphite reflector. Theoretical study has shown that the expected fuel temperature in the core could be up to 300 deg C at nominal power. For that reason temperature of the capsule with the uranium sample was measured during irradiation by using thermocouples. Results showed the discrepancy between measure and calculated values to be about 30%.
Thermal Margin Calculation of the CAREM-25 Core
International Nuclear Information System (INIS)
Mazufri, C.M
2000-01-01
During the operation in steady state and anticipated operational transient of a nuclear reactor it is necessary to avoid the damage in the fuel elements induced by thermal or hydraulic effects.To satisfy that design bases safety limits are established and calculation methodologies are defined to verify them.In the particular case of the reactor CAREM-25 reactor where the core is cooled by natural circulation, it is not adequate to use directly the same calculation methodologies from typical PWR and BWR.The low cooling flow rate and not having channels in the fuel elements (open-channel fuels) produce that most of the models and computer programs typically used must be carefully validated.As result of that process, an adequate calculation procedure for this reactor type was developed.In the present work, the thermal-hydraulic design criteria of the core and the design bases, the uncertainties factors, and the thermal margin results of the core are described.Despite that the methodology of DNBR calculation is under a validation process and considering the available calculation tools, it is possible to assure that the core fulfills the safety regulations in steady state conditions
Energy Technology Data Exchange (ETDEWEB)
Japiassu, Fernando Parois
2013-07-01
When designing radiotherapy treatment rooms, the dimensions of barriers are established on the basis of American calculation methodologies specifically; NCRP Report N° 49, NCRP Report N° 51, and more recently, NCRP Report N° 151. Such barrier calculations are based on parameters reflecting predictions of treatments to be performed within the room; which, in tum, reftect a specific reality found in a country. There exists, however, a variety of modern radiotherapy techniques, such as Intensity Modulated Radiation Therapy (IMRT); Total Body Irradiation (TBl) and radiosurgery (SRS); where patierits are treated in a much different way than during more conventional treatrnents, which are not taken into account the traditional shielding calculation methodology. This may lead to a faulty design of treattnent rooms. In order to establish a comparison between the methodology used to calculate shielding design and the reality of treatments performed in Brazil, two radiotherapy facilitie were selected, both of them offering traditional and modern treatment techniqued as described above. Data in relation with reatments perfotmed over a period of six (6)months of operations in both institutions were collected. Based on tlis informaton, a new set of realistic parameters required for shielding design was estãblished, whicb in turn allowed for a nwe caculation of barrier thickness for both facilities. The barrier thickness resultaing from this calculation was then compared with the barrier thickness propose as part of the original shielding design, approved by the regulatory authority. First, concerning the public facility, the thickness of all primary barriers proposed in the shielding design was actually larger than the thickness resulting from calculations based on realistic parameters. Second, concerning the private facility, the new data show that the thickness of three out of the four primary barriers described in the project is larger than the thickness oresulting from
Energy Technology Data Exchange (ETDEWEB)
Garcia Gutierrez, M E [Empresarios Agrupados, A.I.E., Madrid (Spain); Sustacha Duo, D [C.N. Almaraz, Caceres (Spain)
1993-12-15
The ODCM (Offsite Dose Calculation Manual), the official operational document for all nuclear power plants develops the details for the technical specifications for discharges and governs their practical application. The use of ODCM methodology for managing and controlling data associated with radioactive discharges, as well as the subsequent processing of this data to assess the radiological impact, requires and generates a large volume of data, which demands the frequent application of laborious and complex calculation processes, making computerization necessary. The computer application created for Almaraz NPP has the capacity to store and manage data on all discharges, evaluate their effects, presents reports and copies the information to be sent periodically to the CSN (Spanish Nuclear Regulatory Commission) on a magnetic tape. The radiological impact of an actual or possible discharge can be evaluated at anytime and, furthermore, general or particular reports and graphs on the discharges and doses over time can be readily obtained. The application is run on a personal computer under a relational database management system. This interactive application is based on menus and windows. (author)
International Nuclear Information System (INIS)
Silva Neto, A.J. da; Alvim, A.C.M.
1989-01-01
This work describes the thermalhydraulics code CROSS, designed for micro-computer calculation of heat and mass flow distributions in LWR nuclear reactor cores using the Hardy Cross method. Equations to calculate the pressure variations in the coolant channels are presented, along with derivation of a linear system of equations to calculate the energy balance. This system is solved through the Benachievicz method. A case study is presented, showing that the methodology developed in this work can be used in place of the forward marching multi-channel codes. (author) [pt
1986-01-01
This book is based on a series of lectures for a course on ionic channels held in Santiago, Chile, on November 17-20, 1984. It is intended as a tutorial guide on the properties, function, modulation, and reconstitution of ionic channels, and it should be accessible to graduate students taking their first steps in this field. In the presentation there has been a deliberate emphasis on the spe cific methodologies used toward the understanding of the workings and function of channels. Thus, in the first section, we learn to "read" single channel records: how to interpret them in the theoretical frame of kinetic models, which information can be extracted from gating currents in re lation to the closing and opening processes, and how ion transport through an open channel can be explained in terms of fluctuating energy barriers. The importance of assessing unequivocally the origin and purity of mem brane preparations and the use of membrane vesicles and optical tech niques in the stUGY of ionic channels a...
Gómez Camacho, A.; Wang, Bing; Zhang, H. Q.
2018-05-01
Continuum discretized coupled-channel (CDCC) calculations of total fusion cross sections for reactions induced by the weakly bound nucleus 6Li with targets 28Si, 59Co, 96Zr, 198Pt, and 209Bi at energies around the Coulomb barrier are presented. In the cluster structure frame of 6Li→α +d , short-range absorption potentials are considered for the interactions between the α and d fragments with the targets. The effect of resonance (l =2 , Jπ=3+,2+,1+ ) and nonresonance states of 6Li on fusion is studied by using two approaches: (1) by omitting the resonance states from the full discretized CDCC breakup space and (2) by considering only the resonance subspace. A systematic analysis of the effect on fusion from resonance breakup couplings is carried out from light to heavy mass targets. Among other things, it is found that resonance breakup states produce strong repulsive polarization potentials that lead to fusion suppression. Couplings from nonresonance states give place to weak repulsive potentials at high energies; however, these become attractive for the heavier targets at low energies.
Mimicking multi-channel scattering with single-channel approaches
Grishkevich, Sergey; Schneider, Philipp-Immanuel; Vanne, Yulian V.; Saenz, Alejandro
2009-01-01
The collision of two atoms is an intrinsic multi-channel (MC) problem as becomes especially obvious in the presence of Feshbach resonances. Due to its complexity, however, single-channel (SC) approximations, which reproduce the long-range behavior of the open channel, are often applied in calculations. In this work the complete MC problem is solved numerically for the magnetic Feshbach resonances (MFRs) in collisions between generic ultracold 6Li and 87Rb atoms in the ground state and in the ...
Assessing the Consequences of a Channel Switch
Xinlei (Jack) Chen; George John; Om Narasimhan
2008-01-01
Switching marketing channels is an expensive and sticky decision. While a number of theories suggest efficiency and strategic differences between channels, there is virtually no work on combining these ideas into an empirically workable methodology to assess the impact of a channel switch. In this study, we undertake to close this gap with an empirical study of the sports drink market, featuring competing producers and heterogeneous channels. We estimate demand and cost parameters for a numbe...
Energy Technology Data Exchange (ETDEWEB)
Engstroem, Rebecka; Gode, Jenny; Axelsson, Ulrik
2009-01-15
The guidelines in this report have been developed by IVL Swedish Environmental Research Institute, within a project financed by the Environmental Objectives Council, the Swedish Energy Agency and the Swedish Environmental Protection Agency. The idea originated from an earlier project for the Swedish Energy Agency and the Swedish Environmental Protection Agency, where the potential of a business model for energy efficiency (Energy Performance Contracting, EPC) to contribute to fulfil the national environmental objectives was studied. When environmental impacts from the studied EPC projects was to be calculated, it was evident how many difficult methodological choices one is faced with when trying to follow up the environmental impacts from projects changing the energy use. A second project was then performed to further analyse the issues involved. The result is this guideline report. The guidelines are on the first hand directed at companies and municipalities performing projects with effects on the energy use, that want to calculate impacts from these on the Swedish environmental objectives. The guidelines can also be useful for county administrations, central authorities and other actors with interest in the issues. A starting point for the recommendations is the Swedish environmental objectives, with focus on those of special interest in relation to energy use and airborne emissions. These are Reduced climate impact, Clean air, Natural acidification only, Zero eutrophication and A good built environment. The environmental objectives are mainly concentrated on what affects the Swedish environment. However, not only emissions in Sweden cause such effects, but also emissions in other countries can be transported by air and fall down and cause impacts in Sweden. Thus, the guidelines focus on Sweden, but include to a certain extent also emissions in other countries. Another starting point is that the guidelines are developed to follow up effects from individual
Core design methodology and software for Temelin NPP
International Nuclear Information System (INIS)
Havluj, F; Hejzlar, J.; Klouzal, J.; Stary, V.; Vocka, R.
2011-01-01
In the frame of the process of fuel vendor change at Temelin NPP in the Czech Republic, where, starting since 2010, TVEL TVSA-T fuel is loaded instead of Westinghouse VVANTAGE-6 fuel, new methodologies for core design and core reload safety evaluation have been developed. These documents are based on the methodologies delivered by TVEL within the fuel contract, and they were further adapted according to Temelin NPP operational needs and according to the current practice at NPP. Along with the methodology development the 3D core analysis code ANDREA, licensed for core reload safety evaluation in 2010, have been upgraded in order to optimize the safety evaluation process. New sequences of calculations were implemented in order to simplify the evaluation of different limiting parameters and output visualization tools were developed to make the verification process user friendly. Interfaces to the fuel performance code TRANSURANUS and sub-channel analysis code SUBCAL were developed as well. (authors)
International Nuclear Information System (INIS)
Erramli, H.; Blondiaux, G.
1994-01-01
Channeling phenomenon was predicted, many years ago, by stark. The first channeling experiments were performed in 1963 by Davies and his coworkers. Parallely Robinson and Oen have investigated this process by simulating trajectories of ions in monocrystals. This technique has been combined with many methods like Rutherford Backscattering Spectrometry (R.B.S.), Particles Induced X-rays Emission (P.I.X.E) and online Nuclear Reaction (N.R.A.) to localize trace elements in the crystal or to determine crystalline quality. To use channeling for material characterization we need data about the stopping power of the incident particle in the channeled direction. The ratios of channeled to random stopping powers of silicon for irradiation in the direction have been investigated and compared to the available theoretical results. We describe few applications of ion channeling in the field of materials characterization. Special attention is given to ion channeling combined with Charged Particle Activation Analysis (C.P.A.A.) for studying the behaviour of oxygen atoms in Czochralski silicon lattices under the influence of internal gettering and in different gaseous atmospheres. Association between ion channeling and C.P.A.A was also utilised for studying the influence of the growing conditions on concentration and position of carbon atoms at trace levels in the MOVPE Ga sub (1-x) Al sub x lattice. 6 figs., 1 tab., 32 refs. (author)
Coupling of channel thermalhydraulics and fuel behaviour in ACR-1000 safety analyses
International Nuclear Information System (INIS)
Huang, F.L.; Lei, Q.M.; Zhu, W.; Bilanovic, Z.
2008-01-01
Channel thermalhydraulics and fuel thermal-mechanical behaviour are interlinked. This paper describes a channel thermalhydraulics and fuel behaviour coupling methodology that has been used in ACR-1000 safety analyses. The coupling is done for all 12 fuel bundles in a fuel channel using the channel thermalhydraulics code CATHENA MOD-3.5d/Rev 2 and the transient fuel behaviour code ELOCA 2.2. The coupling approach can be used for every fuel element or every group of fuel elements in the channel. Test cases are presented where a total of 108 fuel element models are set up to allow a full coupling between channel thermalhydraulics and detailed fuel analysis for a channel containing a string of 12 fuel bundles. An additional advantage of this coupling approach is that there is no need for a separate detailed fuel analysis because the coupling analysis, once done, provides detailed calculations for the fuel channel (fuel bundles, pressure tube, and calandria tube) as well as all the fuel elements (or element groups) in the channel. (author)
Channel Identification Machines
Directory of Open Access Journals (Sweden)
Aurel A. Lazar
2012-01-01
Full Text Available We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.
Channel identification machines.
Lazar, Aurel A; Slutskiy, Yevgeniy B
2012-01-01
We present a formal methodology for identifying a channel in a system consisting of a communication channel in cascade with an asynchronous sampler. The channel is modeled as a multidimensional filter, while models of asynchronous samplers are taken from neuroscience and communications and include integrate-and-fire neurons, asynchronous sigma/delta modulators and general oscillators in cascade with zero-crossing detectors. We devise channel identification algorithms that recover a projection of the filter(s) onto a space of input signals loss-free for both scalar and vector-valued test signals. The test signals are modeled as elements of a reproducing kernel Hilbert space (RKHS) with a Dirichlet kernel. Under appropriate limiting conditions on the bandwidth and the order of the test signal space, the filter projection converges to the impulse response of the filter. We show that our results hold for a wide class of RKHSs, including the space of finite-energy bandlimited signals. We also extend our channel identification results to noisy circuits.
International Nuclear Information System (INIS)
Tanabe, Akira.
1993-01-01
In a channel box of a BWR type reactor, protruding pads are disposed in axial position on the lateral side of a channel box opposing to a control rod and facing the outer side portion of the control rod in a reactor core loaded state. In the initial loading stage of fuel assemblies, channel fasteners and spacer pads are abutted against each other in the upper portion between the channel boxes sandwiching the control rod therebetween. Further, in the lower portion, a gap as a channel for the movement of the control rod is ensured by the support of fuel support metals. If the channel box is bent toward the control rod along with reactor operation, the pads are abutted against each other to always ensure the gap through which the control rod can move easily. Further, when the pads are brought into contact with each other, the bending deformation of the channel box is corrected by urging to each other. Thus, the control rod can always be moved smoothly to attain reactor safety operation. (N.H.)
ZnO-channel thin-film transistors: Channel mobility
International Nuclear Information System (INIS)
Hoffman, R.L.
2004-01-01
ZnO-channel thin-film transistor (TFT) test structures are fabricated using a bottom-gate structure on thermally oxidized Si; ZnO is deposited via RF sputtering from an oxide target, with an unheated substrate. Electrical characteristics are evaluated, with particular attention given to the extraction and interpretation of transistor channel mobility. ZnO-channel TFT mobility exhibits severe deviation from that assumed by ideal TFT models; mobility extraction methodology must accordingly be recast so as to provide useful insight into device operation. Two mobility metrics, μ avg and μ inc , are developed and proposed as relevant tools in the characterization of nonideal TFTs. These mobility metrics are employed to characterize the ZnO-channel TFTs reported herein; values for μ inc as high as 25 cm2/V s are measured, comprising a substantial increase in ZnO-channel TFT mobility as compared to previously reported performance for such devices
Assesment of strength and integrity of fuel channels
International Nuclear Information System (INIS)
2000-01-01
Detailed analysis to base strength and integrity of fuel channels was necessary for the licensing process. Description of tasks performed in this direction in 1999 is presented: fuel channel independent strength calculations, assessment of present fuel channels state, analysis of dynamic processes during partial group distribution header rupture, structural integrity analysis of fuel channels located next to broke channel
Defect Distributions in Channeling Experiments
DEFF Research Database (Denmark)
Andersen, Hans Henrik; Sigmund, P.
1965-01-01
A simple collision model allows to calculate energy losses of perfectly channeled particles. The maximum energy loss is related in a simple way to the displacement energy of lattice atoms perpendicular to the channel. From that, one obtains rather definite predictions on the possibility...... of radiation damage by channeled particles. As an application, one gets a necessary criterion for the occurence of super tails in channeling experiments. The theory involves some assumptions on the behaviour of Born-Mayer potentials which are verified by comparison to experimental displacement energies....
International Nuclear Information System (INIS)
Sizmann, R.; Varelas, C.
1976-01-01
There is experimental evidence that swift light ions incident at small angles towards single crystalline surfaces can lose an appreciable fraction of their kinetic energy during reflection. It is shown that these projectiles penetrate into the bulk surface region of the crystal. They can travel as channeled particles along long paths through the solid (surface channeling). The angular distribution and the depth history of the re-emerged projectiles are investigated by computer simulations. A considerable fraction of the penetrating projectiles re-emerges from the crystal with constant transverse energy if the angle of incidence is smaller than the critical angle for axial channeling. Analytical formulae are derived based on a diffusion model for surface channeling. A comparison with experimental data exhibits the relevance of the analytical solutions. (Auth.)
International Nuclear Information System (INIS)
Gomez Parada, Ines
2004-01-01
This paper develops the MIRD (Medical Internal Radiation Dose) methodology for the evaluation of the internal dose due to the administration of radiopharmaceuticals. In this second part, different methods for the calculation of the accumulated activity are presented, together with the effective half life definition. Different forms of Retention Activity curves are also shown. (author)
Hyperfine 3D neutronic calculations in CANDU supercells
International Nuclear Information System (INIS)
Balaceanu, V.; Aioanei, L.; Pavelescu, M.
2010-01-01
For an accurate evaluation of the fuel performances, it is very important to have capability to calculate the three dimensional spatial flux distributions in the fuel bundle. According this issue, in our Institute, a multigroup calculation methodology named WIMS-PIJXYZ was especially developed for estimating the local neutronic parameters in CANDU cell/supercells. The objective of this paper is to present this calculation methodology and to use it in performing some hyperfine neutronic calculations in CANDU type supercells. More exactly, after a short description for the WIMS-PIJXYZ methodology, the end effect for some CANDU fuel bundles is estimated. The WIMS-PIJXYZ methodology is based on WIMS and PIJXYZ transport codes. WIMS is a standard lattice-cell code and it is used for generating the multigroup macroscopic cross sections for the materials in the fuel cells. For obtaining the flux and power distributions in CANDU fuel bundles the PIJXYZ code is used. This code is consistent with WIMS lattice-cell calculations and allows a good geometrical representation of the CANDU bundle in three dimensions. The end effect consists in the increasing of the thermal neutron flux in the end region and the increasing of power in the end of the fuel rod. The region separating the CANDU fuel in two adjoining bundles in a channel is called the 'end region' and the end of the last pellet in the fuel stack adjacent to the end region is called the 'fuel end'. The end effect appears because the end region of the bundle is made up of coolant and Zircaloy-4, a very low neutron absorption material. To estimate the end effect, the flux peaking factors and the power peaking factors are calculated. It was taken in consideration CANDU Standard (Natural Uranium, with 37 elements) fuel bundles. In the end of the paper, the results obtained by WIMS-PIJXYZ methodology with the similar LEGENTR results are compared. The comparative analysis shows a good agreement. (authors)
Energy Technology Data Exchange (ETDEWEB)
Haydon, S. C. [Department of Physics, University of New England, Armidale, NSW (Australia)
1968-04-15
A brief summary is given of the principal methods used for initiating spark channels and the various highly time-resolved techniques developed recently for studies with nanosecond resolution. The importance of the percentage overvoltage in determining the early history and subsequent development of the various phases of the growth of the spark channel is discussed. An account is then given of the recent photographic, oscillographic and spectroscopic investigations of spark channels initiated by co-axial cable discharges of spark gaps at low [{approx} 1%] overvoltages. The phenomena observed in the development of the immediate post-breakdown phase, the diffuse glow structure, the growth of the luminous filament and the final formation of the spark channel in hydrogen are described. A brief account is also given of the salient features emerging from corresponding studies of highly overvolted spark gaps in which the spark channel develops from single avalanche conditions. The essential differences between the two types of channel formation are summarized and possible explanations of the general features are indicated. (author)
Improvement of Metroliner Telephone Channel Capacity and Modeling of Telephone Channel Demands
1972-03-01
The channel capacity of the present Metroliner telephone system is analyzed and methods are proposed to increase that capacity without increasing the overall bandwidth. To determine the number of channels required, calculations have been carried out ...
MIRD methodology; Metodologia MIRD
Energy Technology Data Exchange (ETDEWEB)
Rojo, Ana M [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Gomez Parada, Ines [Sociedad Argentina de Radioproteccion, Buenos Aires (Argentina)
2004-07-01
The MIRD (Medical Internal Radiation Dose) system was established by the Society of Nuclear Medicine of USA in 1960 to assist the medical community in the estimation of the dose in organs and tissues due to the incorporation of radioactive materials. Since then, 'MIRD Dose Estimate Report' (from the 1 to 12) and 'Pamphlets', of great utility for the dose calculations, were published. The MIRD system was planned essentially for the calculation of doses received by the patients during nuclear medicine diagnostic procedures. The MIRD methodology for the absorbed doses calculations in different tissues is explained.
Calculation of a toroidal labyrinth shields
International Nuclear Information System (INIS)
Sul'kin, A.G.
1979-01-01
Calculation of protective case with a toroidal labyrinth channel, being one of the main design elements of hose gamma-devices, is presented. The case provides relative isotropic distribution of radiation outside protection limits. The main geometric parameters of the channel are determined: r-radius of the channel hole, rho-bend radius of the channel axis, β-angle of the channel bend. General exposure dose rate of γ-radiation in the detection point at l distance (usually l=100 m during calculations), is also calculated. Differential current dose albedo values have been found for certain combinations of parameters of the labyrinth channel. It is considered for simplification of labyrinth channel calculations, that backward radiation scattering passes, without energy change and isotropically, due to which differential current albedo values of γ-radiation for any incidence angle may be determined from integral albedo current values by the empirie formula
Optical Communications Channel Combiner
Quirk, Kevin J.; Quirk, Kevin J.; Nguyen, Danh H.; Nguyen, Huy
2012-01-01
NASA has identified deep-space optical communications links as an integral part of a unified space communication network in order to provide data rates in excess of 100 Mb/s. The distances and limited power inherent in a deep-space optical downlink necessitate the use of photon-counting detectors and a power-efficient modulation such as pulse position modulation (PPM). For the output of each photodetector, whether from a separate telescope or a portion of the detection area, a communication receiver estimates a log-likelihood ratio for each PPM slot. To realize the full effective aperture of these receivers, their outputs must be combined prior to information decoding. A channel combiner was developed to synchronize the log-likelihood ratio (LLR) sequences of multiple receivers, and then combines these into a single LLR sequence for information decoding. The channel combiner synchronizes the LLR sequences of up to three receivers and then combines these into a single LLR sequence for output. The channel combiner has three channel inputs, each of which takes as input a sequence of four-bit LLRs for each PPM slot in a codeword via a XAUI 10 Gb/s quad optical fiber interface. The cross-correlation between the channels LLR time series are calculated and used to synchronize the sequences prior to combining. The output of the channel combiner is a sequence of four-bit LLRs for each PPM slot in a codeword via a XAUI 10 Gb/s quad optical fiber interface. The unit is controlled through a 1 Gb/s Ethernet UDP/IP interface. A deep-space optical communication link has not yet been demonstrated. This ground-station channel combiner was developed to demonstrate this capability and is unique in its ability to process such a signal.
Directory of Open Access Journals (Sweden)
Ljiljana Stošić Mihajlović
2014-07-01
Full Text Available Marketing channel is a set of entities and institutions, completion of distribution and marketing activities, attend the efficient and effective networking of producers and consumers. Marketing channels include the total flows of goods, money and information taking place between the institutions in the system of marketing, establishing a connection between them. The functions of the exchange, the physical supply and service activities, inherent in the system of marketing and trade. They represent paths which products and services are moving after the production, which will ultimately end up buying and eating by the user.
DEFF Research Database (Denmark)
Cheesman, Robin; Faraone, Roque
2002-01-01
This is an English version of the methodology chapter in the authors' book "El caso Berríos: Estudio sobre información errónea, desinformación y manipulación de la opinión pública".......This is an English version of the methodology chapter in the authors' book "El caso Berríos: Estudio sobre información errónea, desinformación y manipulación de la opinión pública"....
Energy Technology Data Exchange (ETDEWEB)
Cadenas Mendicoa, A. M.; Benito Hernandez, M.; Barreira Pereira, P.
2012-07-01
This study involves the development of the methodology and three-dimensional models to estimate the damage to the vessel internals of a commercial PWR reactor from irradiation history of operating cycles.
Energy Technology Data Exchange (ETDEWEB)
Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Corona, Aldo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nguyen, Anh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2014-09-01
A MS Excel program has been written that calculates accidental, or unintentional, ion channeling in cubic bcc, fcc and diamond lattice crystals or polycrystalline materials. This becomes an important issue when simulating the creation by energetic neutrons of point displacement damage and extended defects using beams of ions. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different powers of the argument. The program then offers an extremely convenient way to calculate axial and planar half-angles and minimum yield or dechanneling probabilities, effects on half-angles of amorphous overlayers, accidental channeling probabilities for randomly oriented crystals or crystallites, and finally a way to automatically generate stereographic projections of axial and planar channeling half-angles. The program can generate these projections and calculate these probabilities for
Channel Power in Multi-Channel Environments
M.G. Dekimpe (Marnik); B. Skiera (Bernd)
2004-01-01
textabstractIn the literature, little attention has been paid to instances where companies add an Internet channel to their direct channel portfolio. However, actively managing multiple sales channels requires knowing the customers’ channel preferences and the resulting channel power. Two key
Channel box dimension measuring method
International Nuclear Information System (INIS)
Oshima, Hirotake; Jo, Hiroto.
1994-01-01
The present invention provides a method for measuring the entire length of a channel box of a fuel assembly of a BWR type reactor. Namely, four sensors are used as one set that generate ultrasonic waves from oblique upper portion, oblique lower portion, upper portion and lower portion of the channel box respectively. The distances between the four sensors and each of the portions of the channel box are measured respectively for both of a reference member and a member to be measured. The entire length of the channel box is measured by calculating the measured values and the angles of the obliquely disposed sensors according to a predetermined formula. According to the method of the present invention, the inclination of the channel box to be measured can be corrected. In addition, accuracy of the measurement is improved and the measuring time is saved as well as the measuring device and operation can be simplified. (I.S.)
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...
Mathematical model of melt flow channel granulator
Directory of Open Access Journals (Sweden)
A. A. Kiselev
2016-01-01
Full Text Available Granulation of carbohydrate-vitamin-mineral supplements based on molasses is performed at a high humidity (26 %, so for a stable operation of granulator it is necessary to reveal its melt flow pattern. To describe melt non-isothermal flow in the granulator a mathematical model with following initial equations: continuity equation, motion equation and rheological equation – was developed. The following assumptions were adopted: the melt flow in the granulator is a steady laminar flow; inertial and gravity forces can be ignored; melt is an incompressible fluid; velocity gradient in the flow direction is much smaller than in the transverse direction; the pressure gradient over the cross section of the channel is constant; the flow is hydrodynamically fully developed; effects impact on the channel inlet and outlet may be neglected. Due to the assumptions adopted, it can be considered that in this granulator only velocity components in the x-direction are significant and all the members of the equation with the components and their derivatives with respect to the coordinates y and z can be neglected. The resulting solutions were obtained: the equation for the mean velocity, the equation for determining the volume flow, the formula for calculating of mean time of the melt being in the granulator, the equation for determining the shear stress, the equation for determining the shear rate and the equation for determining the pressure loss. The results of calculations of the equations obtained are in complete agreement with the experimental data; deviation range is 16–19 %. The findings about the melt movement pattern in granulator allowed developing a methodology for calculating a rational design of the granulator molding unit.
Energy Technology Data Exchange (ETDEWEB)
Magne, L
1997-12-31
The purpose of this text is first to ask a certain number of questions on the methods related to PSAs. Notably we will explore the positioning of the French methodological approach - as applied in the EPS 1300{sup 1} and EPS 900{sup 2} PSAs - compared to other approaches (Part One). This reflection leads to more general reflection: what contents, for what PSA? This is why, in Part Two, we will try to offer a framework for definition of the criteria a PSA should satisfy to meet the clearly identified needs. Finally, Part Three will quickly summarize the questions approached in the first two parts, as an introduction to the debate. 15 refs.
International Nuclear Information System (INIS)
Magne, L.
1996-01-01
The purpose of this text is first to ask a certain number of questions on the methods related to PSAs. Notably we will explore the positioning of the French methodological approach - as applied in the EPS 1300 1 and EPS 900 2 PSAs - compared to other approaches (Part One). This reflection leads to more general reflection: what contents, for what PSA? This is why, in Part Two, we will try to offer a framework for definition of the criteria a PSA should satisfy to meet the clearly identified needs. Finally, Part Three will quickly summarize the questions approached in the first two parts, as an introduction to the debate. 15 refs
HYTRAN: hydraulic transient code for investigating channel flow stability
International Nuclear Information System (INIS)
Kao, H.S.; Cardwell, W.R.; Morgan, C.D.
1976-01-01
HYTRAN is an analytical program used to investigate the possibility of hydraulic oscillations occurring in a reactor flow channel. The single channel studied is ordinarily the hot channel in the reactor core, which is parallel to other channels and is assumed to share a constant pressure drop with other channels. Since the channel of highest thermal state is studied, provision is made for two-phase flow that can cause a flow instability in the channel. HYTRAN uses the CHATA(1) program to establish a steady-state condition. A heat flux perturbation is then imposed on the channel, and the flow transient is calculated as a function of time
International Nuclear Information System (INIS)
Milosevic, M.; Cupac, S.; Pesic, M.
2005-01-01
The methodology for equivalent gamma dose rate determination on the outer surface of existing containers with the spent fuel elements of the RA reactor is briefly summarised, and experimental verification of this methodology in the field of gamma rays near the aluminium channel with spent fuel elements lifted from the stainless steel containers no. 275 in the RA reactor hall is presented. The proposed methodology is founded on: the existing fuel burnup data base; methods and models for the photon source determination in the RA reactor spent fuel elements developed in the Vinca Institute, and validated Monte Carlo codes for the equivalent gamma dose rate calculations. (author) [sr
Channelling and electromagnetic radiation of channelling particles
International Nuclear Information System (INIS)
Kalashnikov, N.
1983-01-01
A brief description is presented of the channelling of charged particles between atoms in the crystal lattice. The specificities are discussed of the transverse motion of channelling particles as are the origin and properties of quasi-characteristic radiation of channelling particles which accompany transfers from one band of permissible energies of the transverse motion of channelling particles to the other. (B.S.)
Methodology for thermal-hydraulics analysis of pool type MTR fuel research reactors
International Nuclear Information System (INIS)
Umbehaun, Pedro Ernesto
2000-01-01
This work presents a methodology developed for thermal-hydraulic analysis of pool type MTR fuel research reactors. For this methodology a computational program, FLOW, and a model, MTRCR-IEAR1 were developed. FLOW calculates the cooling flow distribution in the fuel elements, control elements, irradiators, and through the channels formed among the fuel elements and among the irradiators and reflectors. This computer program was validated against experimental data for the IEA-R1 research reactor core at IPEN-CNEN/SP. MTRCR-IEAR1 is a model based on the commercial program Engineering Equation Solver (EES). Besides the thermal-hydraulic analyses of the core in steady state accomplished by traditional computational programs like COBRA-3C/RERTR and PARET, this model allows to analyze parallel channels with different cooling flow and/or geometry. Uncertainty factors of the variables from neutronic and thermalhydraulic calculation and also from the fabrication of the fuel element are introduced in the model. For steady state analyses MTRCR-IEAR1 showed good agreement with the results of COBRA-3C/RERTR and PARET. The developed methodology was used for the calculation of the cooling flow distribution and the thermal-hydraulic analysis of a typical configuration of the IEA-R1 research reactor core. (author)
Schmitz, Arne; Schinnenburg, Marc; Gross, James; Aguiar, Ana
For any communication system the Signal-to-Interference-plus-Noise-Ratio of the link is a fundamental metric. Recall (cf. Chapter 9) that the SINR is defined as the ratio between the received power of the signal of interest and the sum of all "disturbing" power sources (i.e. interference and noise). From information theory it is known that a higher SINR increases the maximum possible error-free transmission rate (referred to as Shannon capacity [417] of any communication system and vice versa). Conversely, the higher the SINR, the lower will be the bit error rate in practical systems. While one aspect of the SINR is the sum of all distracting power sources, another issue is the received power. This depends on the transmitted power, the used antennas, possibly on signal processing techniques and ultimately on the channel gain between transmitter and receiver.
International Nuclear Information System (INIS)
Abelin, H.; Birgersson, L.; Widen, H.; Aagren, T.; Moreno, L.; Neretnieks, I.
1990-07-01
Channeling of water flow and tracer transport in real fractures in a granite body at Stripa have been investigated experimentally. The experimental site was located 360 m below the ground level. Two kinds of experiments were performed. In the single hole experiments, 20 cm diameter holes were drilled about 2.5 m into the rock in the plane of the fracture. Specially designed packers were used to inject water into the fracture in 5 cm intervals all along the fracture trace in the hole. The variation of the injection flowrates along the fracture were used to determine the transmissivity variations in the fracture plane. Detailed photographs were taken from inside the hole and the visual fracture aperture was compared with the injection flowrates in the same locations. Geostatistical methods were used to evaluate the results. Five holes were measured in great detail. In addition 7 holes were drilled and scanned by simpler packer systems. A double hole experiment was performed where two parallel holes were drilled in the same fracture plane at nearly 2 m distance. Pressure pulse tests were made between the holes in both directions. Tracers were injected in 5 locations in one hole and monitored for in many locations in the other hole. The single hole experiment and the double hole experiment show that most of the fracture planes are tight but that there are open sections which form connected channels over distances of at least 2 meters. It was also found in the double hole experiment that the investigated fracture was intersected by at least one fracture between the two holes which diverted a large amount of the injected tracers to several distant locations at the tunnel wall. (authours)
Energy Technology Data Exchange (ETDEWEB)
Bender, M.A.
1990-01-01
Several methodologies are available for screening human populations for exposure to ionizing radiation. Of these, aberration frequency determined in peripheral blood lymphocytes is the best developed. Individual exposures to large doses can easily be quantitated, and population exposures to occupational levels can be detected. However, determination of exposures to the very low doses anticipated from a low-level radioactive waste disposal site is more problematical. Aberrations occur spontaneously, without known cause. Exposure to radiation induces no new or novel types, but only increases their frequency. The limitations of chromosomal aberration dosimetry for detecting low level radiation exposures lie mainly in the statistical signal to noise'' problem, the distribution of aberrations among cells and among individuals, and the possible induction of aberrations by other environmental occupational or medical exposures. However, certain features of the human peripheral lymphocyte-chromosomal aberration system make it useful in screening for certain types of exposures. Future technical developments may make chromosomal aberration dosimetry more useful for low-level radiation exposures. Other methods, measuring gene mutations or even minute changes on the DNA level, while presently less will developed techniques, may eventually become even more practical and sensitive assays for human radiation exposure. 15 refs.
International Nuclear Information System (INIS)
Bender, M.A.
1990-01-01
Several methodologies are available for screening human populations for exposure to ionizing radiation. Of these, aberration frequency determined in peripheral blood lymphocytes is the best developed. Individual exposures to large doses can easily be quantitated, and population exposures to occupational levels can be detected. However, determination of exposures to the very low doses anticipated from a low-level radioactive waste disposal site is more problematical. Aberrations occur spontaneously, without known cause. Exposure to radiation induces no new or novel types, but only increases their frequency. The limitations of chromosomal aberration dosimetry for detecting low level radiation exposures lie mainly in the statistical ''signal to noise'' problem, the distribution of aberrations among cells and among individuals, and the possible induction of aberrations by other environmental occupational or medical exposures. However, certain features of the human peripheral lymphocyte-chromosomal aberration system make it useful in screening for certain types of exposures. Future technical developments may make chromosomal aberration dosimetry more useful for low-level radiation exposures. Other methods, measuring gene mutations or even minute changes on the DNA level, while presently less will developed techniques, may eventually become even more practical and sensitive assays for human radiation exposure. 15 refs
RHIC Data Correlation Methodology
International Nuclear Information System (INIS)
Michnoff, R.; D'Ottavio, T.; Hoff, L.; MacKay, W.; Satogata, T.
1999-01-01
A requirement for RHIC data plotting software and physics analysis is the correlation of data from all accelerator data gathering systems. Data correlation provides the capability for a user to request a plot of multiple data channels vs. time, and to make meaningful time-correlated data comparisons. The task of data correlation for RHIC requires careful consideration because data acquisition triggers are generated from various asynchronous sources including events from the RHIC Event Link, events from the two Beam Sync Links, and other unrelated clocks. In order to correlate data from asynchronous acquisition systems a common time reference is required. The RHIC data correlation methodology will allow all RHIC data to be converted to a common wall clock time, while still preserving native acquisition trigger information. A data correlation task force team, composed of the authors of this paper, has been formed to develop data correlation design details and provide guidelines for software developers. The overall data correlation methodology will be presented in this paper
International Nuclear Information System (INIS)
Scholtyssek, W.
1995-01-01
In the first phase of a benchmark comparison, the CONTAIN code was used to calculate an assumed EPR accident 'medium-sized leak in the cold leg', especially for the first two days after initiation of the accident. The results for global characteristics compare well with those of FIPLOC, MELCOR and WAVCO calculations, if the same materials data are used as input. However, significant differences show up for local quantities such as flows through leakages. (orig.)
Stability analysis for downflow in heated channels
International Nuclear Information System (INIS)
Sampaio, P.A.B. de.
1985-01-01
Stability and flow distribution are analysed for downflow in heated channels. It is shown that at low flow rates instabilities associated with the buoyancy forces may appear. A computer code in FORTRAN language to determine downflow distribution among n heated channels is presented. The model used to calculate downflow distribution and the onset of instability is compared with experiments performed in a test section with two parallel channels. (Author) [pt
A Robust Threshold for Iterative Channel Estimation in OFDM Systems
Directory of Open Access Journals (Sweden)
A. Kalaycioglu
2010-04-01
Full Text Available A novel threshold computation method for pilot symbol assisted iterative channel estimation in OFDM systems is considered. As the bits are transmitted in packets, the proposed technique is based on calculating a particular threshold for each data packet in order to select the reliable decoder output symbols to improve the channel estimation performance. Iteratively, additional pilot symbols are established according to the threshold and the channel is re-estimated with the new pilots inserted to the known channel estimation pilot set. The proposed threshold calculation method for selecting additional pilots performs better than non-iterative channel estimation, no threshold and fixed threshold techniques in poor HF channel simulations.
Quantum capacity of Pauli channels with memory
International Nuclear Information System (INIS)
Huang Peng; He Guangqiang; Lu Yuan; Zeng Guihua
2011-01-01
The amount of coherent quantum information that can be reliably transmitted down the memory Pauli channels with Markovian correlated noise is investigated. Two methods for evaluating the quantum capacity of the memory Pauli channels are proposed to try to trace the memory effect on the transmissions of quantum information. We show that the evaluation of quantum capacity can be reduced to the calculation of the initial memory state of each successive transmission. Furthermore, we derive quantum capacities of the memory phase flip channel, bit flip channel and bit-phase flip channel. Also, a lower bound of the quantum capacity of the memory depolarizing channel is obtained. An increase of the degree of memory of the channels has a positive effect on the increase of their quantum capacities.
Effects of dislocations on electron channeling
International Nuclear Information System (INIS)
George, Juby; Pathak, A P
2009-01-01
The phenomenon of electron channeling in a crystal affected by dislocations is considered. Earlier we had considered the quantum aspects of the positron channeling in a crystal bent by dislocations where the effects of longitudinal motion of the particle were also considered along with the transverse motion. In this paper, the effective potential for the electron case is found for the two regions of dislocation-affected channel. There is considerable shift in the potential minima due to dislocations. The frequency and the corresponding spectrum of the channeling radiation due to electrons channeling through the perfect channel and the two regions of dislocation-affected channels are calculated. The spectral distribution of radiation intensity changes with the parameters of dislocation. The continuity of wavefunctions and their derivatives is used at the three boundaries and the reflection and transmission coefficients are found using these boundary conditions in the same way as in the positron case.
International Nuclear Information System (INIS)
Cavinato, M.; Marangoni, M.; Saruis, A.M.
1984-01-01
Description is given of the Electron programme for IBM 370/168 computer, written in Fortran 4. language. The programme calculates (e,e') cross-sections and longitudinal/transverse form factors for closed shell nuclei in the framework of a self-consistent RPA theory
Static analysis of material testing reactor cores:critical core calculations
International Nuclear Information System (INIS)
Nawaz, A. A.; Khan, R. F. H.; Ahmad, N.
1999-01-01
A methodology has been described to study the effect of number of fuel plates per fuel element on critical cores of Material Testing Reactors (MTR). When the number of fuel plates are varied in a fuel element by keeping the fuel loading per fuel element constant, the fuel density in the fuel plates varies. Due to this variation, the water channel width needs to be recalculated. For a given number of fuel plates, water channel width was determined by optimizing k i nfinity using a transport theory lattice code WIMS-D/4. The dimensions of fuel element and control fuel element were determined using this optimized water channel width. For the calculated dimensions, the critical cores were determined for the given number of fuel plates per fuel element by using three dimensional diffusion theory code CITATION. The optimization of water channel width gives rise to a channel width of 2.1 mm when the number of fuel plates is 23 with 290 g ''2''3''5U fuel loading which is the same as in the case of Pakistan Reactor-1 (PARR-1). Although the decrease in number of fuel element results in an increase in optimal water channel width but the thickness of standard fuel element (SFE) and control fuel element (CFE) decreases and it gives rise to compact critical and equilibrium cores. The criticality studies of PARR-1 are in good agreement with the predictions
Energy Technology Data Exchange (ETDEWEB)
Sievers, Juergen; Heckmann, Klaus; Blaesius, Christoph
2015-06-15
For the demonstration of break preclusion for pressure retaining components in nuclear power plants, the nuclear safety standard KTA 3206 determines also the requirements for the leak-before-break verification. For this procedure, it has to be ensured that a wall-penetrating crack is subcritical with respect to instable growth, and that the resulting leakage under stationary operation conditions can be detected by a leak detection system. Within the scope of the project 3613R01332 analyses with respect to conservative estimates of the leak rates in case of detections regarding break preclusion were performed by means of leak rate models being available at GRS. For this purpose, conservative assumptions in the procedure were quantified by comparative calculations concerning selected leak rate experiments and the requirements regarding the determination of leak rates indicated in the KTA 3206 were verified and specified. Moreover, the models were extended and relevant recommendations for the calculation procedure were developed. During the investigations of leak rate tests the calculation methods were validated, qualified by means of both examples indicated in KTA 3206 and applied to a postulated leak accident in the cooling circuit of a PWR. For the calculation of leak rates several simplified solution methods which are included in the GRS program WinLeck were applied, and for the simulation of a leak accident the large-scale programs ANSYS Mechanical and ATHLET (thermohydraulics program developed by GRS) were used. When applying simplified methods for the calculation of leak rates using the limiting curve for the friction factor which has been derived during the project and which is included in the KTA 3206 attention has to be paid to the fact that in case of small flow lengths the entrance loss can dominate compared to the friction loss. However, the available data do not suffice in order to make a quantitative statement with respect to limits of applicability
Aspects regarding the lifetime of a fuel channel in a CANDU nuclear power plant
International Nuclear Information System (INIS)
Calinescu, A.
1998-01-01
The paper presents the analysis of factors influencing upon the time life of a fuel channel of CANDU reactors built in Romania. Fuel channels are made of Zr-2.5%Nb alloy. Means and methodology to detect cracking of fuel channels are described, as well as improvements to increase life time of Cernavoda NPP fuel channels and national programme in this area. (author)
LDPC Code Design for Nonuniform Power-Line Channels
Directory of Open Access Journals (Sweden)
Sanaei Ali
2007-01-01
Full Text Available We investigate low-density parity-check code design for discrete multitone channels over power lines. Discrete multitone channels are well modeled as nonuniform channels, that is, different bits experience various channel parameters. We propose a coding system for discrete multitone channels that allows for using a single code over a nonuniform channel. The number of code parameters for the proposed system is much greater than the number of code parameters in conventional channel. Therefore, search-based optimization methods are impractical. We first formulate the problem of optimizing the rate of an irregular low-density parity-check code, with guaranteed convergence over a general nonuniform channel, as an iterative linear programming which is significantly more efficient than search-based methods. Then we use this technique for a typical power-line channel. The methodology of this paper is directly applicable to all decoding algorithms for which a density evolution analysis is possible.
Wang, Hongjuan; Han, Genquan; Wang, Yibo; Peng, Yue; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hu, Shengdong; Hao, Yue
2016-04-01
In this work, a lattice-matched SiGeSn/GeSn heterostructure p-channel tunneling field-effect transistor (hetero-PTFET) with a type-II staggered tunneling junction (TJ) is investigated theoretically. Lattice matching and type-II band alignment at the Γ-point is obtained at the SiGeSn/GeSn interface by tuning Sn and Si compositions. A steeper subthreshold swing (SS) and a higher on state current (I ON) are demonstrated in SiGeSn/GeSn hetero-PTFET than in GeSn homo-PTFET. Si0.31Ge0.49Sn0.20/Ge0.88Sn0.12 hetero-PTFET achieves a 2.3-fold higher I ON than Ge0.88Sn0.12 homo-PTFET at V DD of 0.3 V. Hetero-PTFET achieves a more abrupt hole profile and a higher carrier density near TJ than the homo-PTFET, which contributes to the significantly enhanced band-to-band tunneling (BTBT) rate and tunneling current in hetero-PTFET.
Energy Technology Data Exchange (ETDEWEB)
Escandon Jimenez, Alejandro C. [Mexico, D.F. (Mexico)
2004-06-15
The importance of knowing the performance of the companies within a productive sector has increased in the last years, demonstrating the necessity of knowing and applying tools that help us to know the performance of a company with respect to the others with which it is competing. Recently, a great variety of tools have been developed to know the efficiency or productivity of a company in a certain sector. Nevertheless, the two more used, up to now, are those that will be described in the present in study. Finally, one practical example of the two methodologies will be presented, applied to the natural gas industry for distributing companies of this energy in Latin America. [Spanish] La importancia de conocer el desempeno de las empresas dentro de un sector productivo ha incrementado en los ultimos anos, demostrando la necesidad de conocer y aplicar herramientas que nos ayuden a conocer el desempeno de una empresa con respecto a las demas con las cuales se esta compitiendo. Recientemente, se han desarrollado gran variedad de herramientas para conocer la eficiencia o productividad de una compania en un determinado sector. Sin embargo, las dos mas utilizadas, hasta el momento, son las que se describiran en el presente estudio. Finalmente, se presentara un ejemplo practico de las dos metodologias, aplicado a la industria del gas natural para companias distribuidoras de este energetico en Latinoamerica.
International Nuclear Information System (INIS)
Hoeld, Alois
2007-01-01
. This package can be adopted as a general element in the simulation of thermal-hydraulic situations of complex systems consisting of a number of special channels. Such systems can represent different types of steam generators, 3D nuclear reactor cores with special attention to the calculation of the mass flow distribution into different parallel channels after non-symmetric perturbations, each of them distinguished by their key numbers. The resulting set of equations can be combined with other ODE-s and constitutive equations from additional parts of such a comprehensive model. The complete system of equations can then (outside of the CCM) be solved by applying appropriate integration routines. Verification and validation test runs over a wide application range have yielded very satisfactory results demonstrating therefore in a convincing way the quality of the CCM. This approach offers an alternative to the currently dominant 'Separate-Phase Models' where each phase within a coolant channel is treated separately. The advantages and disadvantages of these two approaches are discussed in this paper
Electron angular distribution axial channeling
International Nuclear Information System (INIS)
Khokonov, A.Kh.; Khokonov, M.Kh.
1989-01-01
Angular distributions of ultra-relativistic electrons are calculated in the assumption about presence of statistical equilibrium. Analysis is based on numerical solution of Fokker-Planck type kinetic equation. It is shown that in contrast to case of amorphous medium, the multiple scattering at axial channeling of negative particles results in self-focusing of the initial beam particles and due to it number of electrons moving at an angles to the chain, which are smaller, than critical angle of channeling, may increase by several times as compared to the initial one
Remarks to the hot channel power characteristics
International Nuclear Information System (INIS)
Tinka, I.; Tinkova, E.
2002-01-01
In connection with methodological improvements of safety analyses, some effects of detail power distributions, that should be taken into account for the hot channel characteristics determination, have been studied. This determination concerns the whole channel power (power of the fuel rod) and its axial (along the channel) and radial (across the fuel pellet radius) distribution. The total power of the channel is studied from the point of possible restrictions for different numbers of main cooling loops in operation. For radial power distribution the effect of burnup has been studied and for axial distribution the effect of the control rod vicinity (its coupler part) has been evaluated. The DNBR and fuel temperatures have been the key safety parameters influenced by these hot channel characteristics and have been evaluated in this study (Authors)
International Nuclear Information System (INIS)
Rhee, B.W.; Shin, T.Y.; Yoo, K.M.; Kim, H.T.; Min, B.-J.; Park, J.H.
2006-01-01
The objective of this study is to develop a new fuel channel safety analysis system for covering both the blowdown analysis including the power pulse and the post-blowdown analysis with the same safety analysis code, CATHENA in a consistent manner. This new safety analysis methodology for a fuel channel analysis is expected to be better than the previous one used for the Wolsong 2,3,4 licensing which used CATHENA for the blowdown analysis and CHAN-II for the post-blowdown analysis, in several areas; consistency in the computer codes used and the modeling methods, the degree of uncertainty in the modeling and calculation. For this aim the existing CATHENA subchannel fuel channel model for a post blowdown analysis has been modified, and thus improved, and a processing program that conveys all the final state of the fuel channel at the end of blowdown analysis to the post-blowdown analysis as the initial conditions has been developed, and tested for its proper implementation for the intended purposes. A comparison of the results of this new analysis method with those of the Wolsong 2/3/4 Safety Analysis confirmed that the total heat transfer rate matches well up to 1000 sec, and then that of the new method begins to under-predict it consistently. On the other hand, the fuel temperatures of the center pin, inner ring fuel and the middle ring fuel are predicted by this new method to be lower than the old method by about 200 - 250 o C at the peak time. Considering the differences in these two analyses methodologies, especially the modeling of the fuel ring, a subchannel flow passage with an intermixing, and the radiation among the solid structures by considering every fuel individually, this trend of the results seems to be physically reasonable. However considerable future validation works are necessary to justify this new methodology for a licensing. (author)
Conveyance estimation in channels with emergent bank vegetation ...
African Journals Online (AJOL)
Emergent vegetation along the banks of a river channel influences its conveyance considerably. The total channel discharge can be estimated as the sum of the discharges of the vegetated and clear channel zones calculated separately. The vegetated zone discharge is often negligible, but can be estimated using ...
International Nuclear Information System (INIS)
Petersen, K.E.
1986-03-01
Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)
McCarty, George
1982-01-01
How THIS BOOK DIFFERS This book is about the calculus. What distinguishes it, however, from other books is that it uses the pocket calculator to illustrate the theory. A computation that requires hours of labor when done by hand with tables is quite inappropriate as an example or exercise in a beginning calculus course. But that same computation can become a delicate illustration of the theory when the student does it in seconds on his calculator. t Furthermore, the student's own personal involvement and easy accomplishment give hi~ reassurance and en couragement. The machine is like a microscope, and its magnification is a hundred millionfold. We shall be interested in limits, and no stage of numerical approximation proves anything about the limit. However, the derivative of fex) = 67.SgX, for instance, acquires real meaning when a student first appreciates its values as numbers, as limits of 10 100 1000 t A quick example is 1.1 , 1.01 , 1.001 , •••• Another example is t = 0.1, 0.01, in the functio...
Citizens and service channels: channel choice and channel management implications
Pieterson, Willem Jan
2010-01-01
The arrival of electronic channels in the 1990s has had a huge impact on governmental service delivery. The new channels have led to many new opportunities to improve public service delivery, not only in terms of citizen satisfaction, but also in cost reduction for governmental agencies. However,
Parametric modeling for damped sinusoids from multiple channels
DEFF Research Database (Denmark)
Zhou, Zhenhua; So, Hing Cheung; Christensen, Mads Græsbøll
2013-01-01
frequencies and damping factors are then computed with the multi-channel weighted linear prediction method. The estimated sinusoidal poles are then matched to each channel according to the extreme value theory of distribution of random fields. Simulations are performed to show the performance advantages......The problem of parametric modeling for noisy damped sinusoidal signals from multiple channels is addressed. Utilizing the shift invariance property of the signal subspace, the number of distinct sinusoidal poles in the multiple channels is first determined. With the estimated number, the distinct...... of the proposed multi-channel sinusoidal modeling methodology compared with existing methods....
Subchannel analysis code development for CANDU fuel channel
International Nuclear Information System (INIS)
Park, J. H.; Suk, H. C.; Jun, J. S.; Oh, D. J.; Hwang, D. H.; Yoo, Y. J.
1998-07-01
Since there are several subchannel codes such as COBRA and TORC codes for a PWR fuel channel but not for a CANDU fuel channel in our country, the subchannel analysis code for a CANDU fuel channel was developed for the prediction of flow conditions on the subchannels, for the accurate assessment of the thermal margin, the effect of appendages, and radial/axial power profile of fuel bundles on flow conditions and CHF and so on. In order to develop the subchannel analysis code for a CANDU fuel channel, subchannel analysis methodology and its applicability/pertinence for a fuel channel were reviewed from the CANDU fuel channel point of view. Several thermalhydraulic and numerical models for the subchannel analysis on a CANDU fuel channel were developed. The experimental data of the CANDU fuel channel were collected, analyzed and used for validation of a subchannel analysis code developed in this work. (author). 11 refs., 3 tabs., 50 figs
Planar channeling in superlattices: Theory
International Nuclear Information System (INIS)
Ellison, J.A.; Picraux, S.T.; Allen, W.R.; Chu, W.K.
1988-01-01
The well-known continuum model theory for planar channeled energetic particles in perfect crystals is extended to layered crystalline structures and applied to superlattices. In a strained-layer structure, the planar channels with normals which are not perpendicular to the growth direction change their direction at each interface, and this dramatically influences the channeling behavior. The governing equation of motion for a planar channeled ion in a strained-layer superlattice with equal layer thicknesses is a one degree of freedom nonlinear oscillator which is periodically forced with a sequence of δ functions. These δ functions, which are of equal spacing and amplitude with alternating sign, represent the tilts at each of the interfaces. Thus upon matching an effective channeled particle wavelength, corresponding to a natural period of the nonlinear oscillator, to the period of the strained-layer superlattice, corresponding to the periodic forcing, strong resonance effects are expected. The condition of one effective wavelength per period corresponds to a rapid dechanneling at a well-defined depth (catastrophic dechanneling), whereas two wavelengths per period corresponds to no enhanced dechanneling after the first one or two layers (resonance channeling). A phase plane analysis is used to characterize the channeled particle motion. Detailed calculations using the Moliere continuum potential are compared with our previously described modified harmonic model, and new results are presented for the phase plane evolution, as well as the dechanneling as a function of depth, incident angle, energy, and layer thickness. General scaling laws are developed and nearly universal curves are obtained for the dechanneling versus depth under catastrophic dechanneling
Calculating radiation exposure and dose
International Nuclear Information System (INIS)
Hondros, J.
1987-01-01
This paper discusses the methods and procedures used to calculate the radiation exposures and radiation doses to designated employees of the Olympic Dam Project. Each of the three major exposure pathways are examined. These are: gamma irradiation, radon daughter inhalation and radioactive dust inhalation. A further section presents ICRP methodology for combining individual pathway exposures to give a total dose figure. Computer programs used for calculations and data storage are also presented briefly
DEFF Research Database (Denmark)
Petersen, Kurt Erling
1986-01-01
Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...
The minimum yield in channeling
International Nuclear Information System (INIS)
Uguzzoni, A.; Gaertner, K.; Lulli, G.; Andersen, J.U.
2000-01-01
A first estimate of the minimum yield was obtained from Lindhard's theory, with the assumption of a statistical equilibrium in the transverse phase-space of channeled particles guided by a continuum axial potential. However, computer simulations have shown that this estimate should be corrected by a fairly large factor, C (approximately equal to 2.5), called the Barrett factor. We have shown earlier that the concept of a statistical equilibrium can be applied to understand this result, with the introduction of a constraint in phase-space due to planar channeling of axially channeled particles. Here we present an extended test of these ideas on the basis of computer simulation of the trajectories of 2 MeV α particles in Si. In particular, the gradual trend towards a full statistical equilibrium is studied. We also discuss the introduction of this modification of standard channeling theory into descriptions of the multiple scattering of channeled particles (dechanneling) by a master equation and show that the calculated minimum yields are in very good agreement with the results of a full computer simulation
The GPT methodology. New fields of application
International Nuclear Information System (INIS)
Gandini, A.; Gomit, J.M.; Abramytchev, V.
1996-01-01
The GPT (Generalized Perturbation Theory) methodology is described, and a new application is discussed. The results obtained for a simple model (zero dimension, six parameters of interest) show that the expressions obtained using the GPT methodology, lead to results close to those obtained through direct calculations. The GPT methodology is useful to be used for radioactive waste disposal problems. The potentiality of the method linked to zero dimension model can be extended to radionuclide migration problems with space description. (K.A.)
National Research Council Canada - National Science Library
Peace, Karl E; Chen, Ding-Geng
2011-01-01
... in the pharmaceutical industry, Clinical trial methodology emphasizes the importance of statistical thinking in clinical research and presents the methodology as a key component of clinical research...
Energy Technology Data Exchange (ETDEWEB)
Blanchet, D
2006-07-01
The objective of this work is to develop the modelling of the nuclear heating of the experimental devices of the future Jules Horowitz material testing reactor (RJH). The strong specific nuclear power produced (460 kW/l), induces so intense photonic fluxes which cause heating and large temperature gradients that it is necessary to control it by an adequate design. However, calculations of heating are penalized by the very large uncertainties estimated at a value of about 30% (2*{sigma}) coming from the gaps and uncertainties of the data of gamma emission present in the libraries of basic nuclear data. The experimental program ADAPh aims at reducing these uncertainties. Measurements by thermoluminescent detectors (TLD) and ionisation chambers are carried out in the critical assemblies EOLE (Mox) and Minerve (UO{sub 2}). The rigorous interpretation of these measurements requires specific developments based on Monte-Carlo simulations of coupled neutron-gamma and gamma-electron transport. The developments carried out are made different in particular by the modelling of cavities phenomena and delayed gamma emissions by the decay of fission products. The comparisons calculation-measurement made it possible to identify a systematic bias confirming a tendency of calculations to underestimate measurements. A Bayesian method of adjustment was developed in order to re-estimate the principal components of the gamma heating and to transpose the results obtained to the devices of the RJH, under conditions clearly and definitely representative. This work made possible to reduce significantly the uncertainties on the determination of the gamma heating from 30 to 15 per cent. (author)
Energy Technology Data Exchange (ETDEWEB)
Blanchet, D
2006-07-01
The objective of this work is to develop the modelling of the nuclear heating of the experimental devices of the future Jules Horowitz material testing reactor (RJH). The strong specific nuclear power produced (460 kW/l), induces so intense photonic fluxes which cause heating and large temperature gradients that it is necessary to control it by an adequate design. However, calculations of heating are penalized by the very large uncertainties estimated at a value of about 30% (2*{sigma}) coming from the gaps and uncertainties of the data of gamma emission present in the libraries of basic nuclear data. The experimental program ADAPh aims at reducing these uncertainties. Measurements by thermoluminescent detectors (TLD) and ionisation chambers are carried out in the critical assemblies EOLE (Mox) and Minerve (UO{sub 2}). The rigorous interpretation of these measurements requires specific developments based on Monte-Carlo simulations of coupled neutron-gamma and gamma-electron transport. The developments carried out are made different in particular by the modelling of cavities phenomena and delayed gamma emissions by the decay of fission products. The comparisons calculation-measurement made it possible to identify a systematic bias confirming a tendency of calculations to underestimate measurements. A Bayesian method of adjustment was developed in order to re-estimate the principal components of the gamma heating and to transpose the results obtained to the devices of the RJH, under conditions clearly and definitely representative. This work made possible to reduce significantly the uncertainties on the determination of the gamma heating from 30 to 15 per cent. (author)
Hopping control channel MAC protocol for opportunistic spectrum access networks
Institute of Scientific and Technical Information of China (English)
FU Jing-tuan; JI Hong; MAO Xu
2010-01-01
Opportunistic spectrum access （OSA） is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access （CHMA） protocol,we introduce a hopping control channel medium access control （MAC） protocol in the context of OSA networks. In our proposed protocol,all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users＇ occupancy of the channel,we use a primary user （PU） detection model to calculate the channel availability for unlicensed users＇ access. Then,a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation,we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.
Accurate quantum chemical calculations
Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.
1989-01-01
An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.
International Nuclear Information System (INIS)
Park, Joo Hwan; Jung, Jong Yeob
2009-09-01
Feeder break accident is regarded as one of the design basis accident in CANDU reactor which results in a fuel failure. For a particular range of inlet feeder break sizes, the flow in the channel is reduced sufficiently that the fuel and fuel channel integrity can be significantly affected to have damage in the affected channel, while the remainder of the core remains adequately cooled. The flow in the downstream channel can be more or less stagnated due to a balance between pressure at the break on the upstream side and the reverse driving pressure between the break and the downstream end. In the extreme, this can lead to rapid fuel heatup and fuel damage and failure of the fuel channel similar to that associated with a severe channel flow blockage. Such an inlet feeder break scenario is called a stagnation break. In this report, the fuel analysis methodology and the assessment results of fission product inventory and release during the stagnation feeder break are described for conservatively assumed limiting channel. The accident was assumed to be occurred in the refurbished Wolsong unit 1 and the latest safety codes were used in the analysis. Fission product inventories during the steady state were calculated by using ELESTRES-IST 1.2 code. The whole analysis process was carried out by a script file which was programmed by Perl language. The perl script file was programmed to make all ELESTRES input files for each bundle and each ring based on the given power-burnup history and thermal-hydraulic conditions of the limiting channel and to perform the fuel analysis automatically. The fission product release during the transient period of stagnation feeder break was evaluated by applying Gehl model. The amounts of each isotope's release are conservatively evaluated for additional 2 seconds after channel failure. The calculated fission product releases are provided to the following dose assessment as a source term
Proton channeling in Au at low energies
International Nuclear Information System (INIS)
Valdes, J.E.; Vargas, P.
1996-01-01
The electronic energy loss for low velocity protons channeled in the direction single crystal Au is calculated. The spatial distribution of valence electronic density in Au is calculated using Tight Binding Linear Muffin Tin Method. The proton trajectories are determined by numerical integration of the classical motion equation, and the energy loss is evaluated using the calculated valence electronic density in the friction term. The results allow to describe qualitatively the non linear behavior of energy loss with ion velocity observed experimentally. (author)
USACE Navigation Channels 2012
California Natural Resource Agency — This dataset represents both San Francisco and Los Angeles District navigation channel lines. All San Francisco District channel lines were digitized from CAD files...
Calcium channel blocker overdose
... this page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used ...
Directory of Open Access Journals (Sweden)
I E. Lobanov
2017-01-01
Full Text Available Objectives. The aim of present work was to carry out mathematical modelling of heat transfer with symmetrical heating in flat channels and round pipes with rough walls.Methods. The calculation was carried out using the L'Hôpital-Bernoulli's method. The solution of the problem of intensified heat transfer in a round tube with rough walls was obtained using the Lyon's integral.Results. Different from existing theories, a methodology of theoretical computational heat transfer determination for flat rough channels and round pipes with rough walls is developed on the basis of the principle of full viscosity superposition in a turbulent boundary layer. The analysis of the calculated heat transfer and hydroresistivity values for flat rough channels and round rough pipes shows that the increase in heat transfer is always less than the corresponding increase in hydraulic resistance, which is a disadvantage as compared to channels with turbulators, with all else being equal. The results of calculating the heat transfer for channels with rough walls in an extended range of determinant parameters, which differ significantly from the corresponding data for the channels with turbulators, determine the level of heat exchange intensification.Conclusion. An increase in the calculated values of the relative average heat transfer Nu/NuGL for flat rough channels and rough pipes with very high values of the relative roughness is significantly contributed by both an increase in the relative roughness height and an increase in the Reynolds number Re. In comparison with empirical dependencies, the main advantage of solutions for averaged heat transfer in rough flat channels and round pipes under symmetrical thermal load obtained according to the developed theory is that they allow the calculation of heat exchange in rough pipes to be made in the case of large and very large relative heights of roughness protrusions, including large Reynolds numbers, typical for pipes
Development of guide thimble stress peaking factor calculation methodology
International Nuclear Information System (INIS)
Lee, Seong Ki; Jeon, Sang Youn; Kim, Jae Ik; Jeon, Kyeong Lak; Kim, Kyu Tae
2004-01-01
The Nuclear Fuel Assembly for light water reactor which provides for 236 fuel rods consists of guide tubes, spacer grids, top/bottom nozzles. The guide tubes form the main structural components in conjunction with the grids, act as the main load carrying members of fuel assembly and serve as a support structure and a guide path for the control element, neutron sources and incore instruments after they are secured to upper and lower end areas. Top/bottom nozzles make the end parts of fuel assembly. And the spacer girds maintain the fuel rod array by providing positive lateral restraint to the fuel rod to the fuel rod but only frictional restraint to axial fuel rod motion. When the fuel assembly is in reactor, the tensional and compressional forces are applied to guide thimble through the top nozzle. The stresses vary with the location of guide thimble on the top nozzle plate since the different flow plate thickness between center and outer areas causes a different flexibility. The relative stress shall be considered during designing this kind of structure. And it is useful to know a coefficient to represent this relative stress difference and this value is called stress peaking factor
42 CFR 413.312 - Methodology for calculating rates.
2010-10-01
... Determined Payment Rates for Low-Volume Skilled Nursing Facilities, for Cost Reporting Periods Beginning... routine service cost limits; (ii) A wage index to adjust for area wage differences; and (iii) The most... of rates published in the Federal Register under the authority of § 413.320, CMS announces the wage...
Revisiting the dose calculation methodologies in European decision support systems
DEFF Research Database (Denmark)
Andersson, Kasper Grann; Roos, Per; Hou, Xiaolin
2012-01-01
The paper presents examples of current needs for improvement and extended applicability of the European decision support systems. The systems were originally created for prediction of the radiological consequences of accidents at nuclear installations. They could however also be of great value in...... for, to introduce new knowledge and thereby improve prognoses....
Methodology for Structural Calculation of Gear Teeth with Unconventional Profile
Directory of Open Access Journals (Sweden)
Radicella Andrea Chiaramonte
2016-01-01
Full Text Available After having made reference to the structural analysis used in the study of gear wheel teeth, we then move on to the state of the art on the topic. We proceed to identify the boundary conditions used in the structural analysis of unconventional teeth with sides having a profile of an involute of a circle but with different pressure angles in each of the two sides. A procedure for the discretization of traditional teeth and of innovative teeth is presented and compared with the discretization obtained using current software.
Current state of copper stabilizers and methodology towards calculating risk
Koratzinos, M
2011-01-01
The talk will start by reviewing the landscape: a brief mention of the results of the warm copper stabilizer measurements and the results of the splice measurements at cold will be shown. The preliminary results of the recent RRR measurements will then be presented. Then, together with the limits presented from talk no. 2, the probability of an incident will be presented for beam energies between 3.5 and 5TeV. The available methods at our disposal for addressing the limiting factors and operating at a higher energy will then be reviewed: a complete circuit qualification method coined the Thermal Amplifier can define the maximum safe energy of the LHC in case of a quench next to a defective joint. Ways of avoiding magnet quenches, another critical element of the analysis, for instance by optimizing BLM settings will then be shown. Finally, a proposal of a strategy for running at the highest possible energy compatible with a pre-defined level of risk will be presented. As a case study, the method will also be a...
Analysis of Solar Census Remote Solar Access Value Calculation Methodology
Energy Technology Data Exchange (ETDEWEB)
Nangle, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Van Geet, O. [National Renewable Energy Lab. (NREL), Golden, CO (United States)
2015-03-01
The costs of photovoltaic (PV) system hardware (PV panels, inverters, racking, etc.) have fallen dramatically over the past few years. Nonhardware (soft) costs, however, have failed to keep pace with the decrease in hardware costs, and soft costs have become a major driver of U.S. PV system prices. Upfront or 'sunken' customer acquisition costs make up a portion of an installation's soft costs and can be addressed through software solutions that aim to streamline sales and system design aspects of customer acquisition. One of the key soft costs associated with sales and system design is collecting information on solar access for a particular site. Solar access, reported in solar access values (SAVs), is a measurement of the available clear sky over a site and is used to characterize the impacts of local shading objects. Historically, onsite shading studies have been required to characterize the SAV of the proposed array and determine the potential energy production of a photovoltaic system.
Developing a Repeatable Methodology to Calculate Retrograde Planning Factors
2015-01-01
supply chain inefficiencies, changes in demand xiv rates, operational tempo, task force organization, drawdown, and redeployment, for which the...and its causes, most notably the effect of supply chain inefficiencies on serviceable retrograde. It should be noted that, because of data limitations... supplies and equipment, and housekeeping supplies and equipment Class IIIP Packaged petroleum products; includes fuel in collapsible containers less
International Nuclear Information System (INIS)
Rybar, T.
2012-01-01
Quantum memory channels represent a very general, yet simple and comprehensible model for causal processes. As such they have attracted considerable research interest, mostly aimed on their transfer capabilities and structure properties. Most notably it was shown that memory channels can be implemented via physically naturally motivated collision models. We also define the concept of repeatable channels and show that only unital channels can be implemented repeat ably with pure memory channels. In the special case of qubit channels we also show that every unital qubit channel has a repeatable implementation. We also briefly explore the possibilities of stroboscopical simulation of channels and show that all random unitary channels can be stroboscopically simulated. Particularly in qubit case, all indivisible qubit channels are also random unitary, hence for qubit all indivisible channels can be stroboscopically simulated. Memory channels also naturally capture the framework of correlated experiments. We develop methods to gather and interpret data obtained in such setting and in detail examine the two qubit case. We also show that for control unitary interactions the measured data will never contradict a simple unitary evolution. Thus no memory effects can be spotted then. (author)
Energy Technology Data Exchange (ETDEWEB)
Waddoup, W D; Stubbs, R J [Durham Univ. (UK)
1977-11-01
An eight channel 64-bit scaler has been constructed with a static CMOS memory. Scaling frequencies are independently variable, at each channel, as are the number of bits/channel. The scaler, when used in conjunction with a multichannel charge to time converter results in a very flexible, gated multichannel ADC.
DEFF Research Database (Denmark)
Stott, Jennifer B; Jepps, Thomas Andrew; Greenwood, Iain A
2014-01-01
Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been...
Methods for U.S. shielding calculations: applications to FFTF and CRBR designs
International Nuclear Information System (INIS)
Engle, W.W. Jr.; Mynatt, F.R.; Disney, R.K.
1978-01-01
The primary components of the U.S. reactor shielding methodology consist of: (1) computer code systems based on discrete ordinates or Monte Carlo radiation transport calculational methods; (2) a data base of neutron and gamma-ray interaction and gamma-ray-production cross sections used as input in the codes; (3) a capability for processing the cross sections into multigroup or point energy formats as required by the codes; (4) large-scale integral shielding experiments designed to test cross-section data or techniques utilized in the calculations; and (5) a ''sensitivity'' analysis capability that can identify the most important interactions in a transport calculation and assign uncertainties to the calculated result that are based on uncertainties in all of the input data. The required accuracy for the methodology is to within 5 to 10% for responses at locations near the core to within a factor of 2 for responses at distant locations. Under these criteria, the methodology has proved to be adequate for in-vessel LMFBR calculations of neutron transport through deep sodium and thick iron and stainless steel shields, of neutron streaming through lower axial coolant channels and primary pipe chaseways, and of the effects of fuel stored within the reactor vessel. For ex-vessel LMFBR problems, the methodology requires considerable improvement, the areas of concern including neutron streaming through heating and ventilation ducts, through the cavity surrounding the reactor vessel, and through gaps around rotating plugs in the reactor heat, as well as gamma-ray streaming through plant shield penetrations
Starck, Patricia L; Love, Karen; McPherson, Robert
2008-01-01
In recent years, the focus has been on increasing the number of registered nurse (RN) graduates. Numerous states have initiated programs to increase the number and quality of students entering nursing programs, and to expand the capacity of their programs to enroll additional qualified students. However, little attention has been focused on an equally, if not more, effective method for increasing the number of RNs produced-increasing the graduation rate of students enrolling. This article describes a project that undertook the task of compiling graduation data for 15 entry-level programs, standardizing terms and calculations for compiling the data, and producing a regional report on graduation rates of RN students overall and by type of program. Methodology is outlined in this article. This effort produced results that were surprising to program deans and directors and is expected to produce greater collaborative efforts to improve these rates both locally and statewide.
Axial channeling in electron diffraction
International Nuclear Information System (INIS)
Ichimiya, A.; Lehmpfuhl, G.
1978-01-01
Kossel patterns from Silicon and Niobium were obtained with a convergent electron beam. An intensity maximum in the direction of the zone axes [001] and [111] of Nb was interpreted as axial channeling. The intensity distribution in Kossel patterns was calculated by means of the Bloch wave picture of the dynamical theory of electron diffraction. Particularly zone axis patterns were calculated for different substance-energy combinations and they were compared with experimental observations. The intensity distribution in the calculated Kossel patterns was very sensitive to the model of absorption and it was found that a treatment of the absorption close to the model of Humphreys and Hirsch [Phil. Mag. 18, 115 (1968)] gave the best agreement with the experimental observations. Furthermore it is shown which Bloch waves are important for the intensity distribution in the Kossel patterns, how they are absorbed and how they change with energy. (orig.) [de
1997-01-01
A color image of fine channel networks on Mars; north toward top. The scene shows heavily cratered highlands dissected by dendritic open channel networks that dissect steep slopes of impact crater walls. This image is a composite of Viking high-resolution images in black and white and low-resolution images in color. The image extends from latitude 9 degrees S. to 5 degrees S. and from longitude 312 degrees to 320 degrees; Mercator projection. The dendritic pattern of the fine channels and their location on steep slopes leads to the interpretation that these are runoff channels. The restriction of these types of channels to ancient highland rocks suggests that these channels are old and date from a time on Mars when conditions existed for precipitation to actively erode rocks. After the channels reach a low plain, they appear to end. Termination may have resulted from burial by younger deposits or perhaps the flows percolated into the surface materials and continued underground.
Directory of Open Access Journals (Sweden)
Sinem Gözde BEŞBALLI
2010-01-01
Full Text Available The effect of a change in monetary policy on output operates through monetary transmission channels. The transmission channels of monetary policy may be gathered in five main titles: interest rates channel, asset prices channel, exchange rate channel, credit channel (bank lending channel, balance sheet channel and expectation channel. Findings obtained from the analysis of the transmission channels can be used in policy determination.This paper empirically analyzes the bank lending channel, one of the transmission mechanisms of monetary policy in Turkey. In this paper, data between 1996:06-2006:09 are examined using VAR methodology. According to the findings, the credit channel in Turkey operates partially.
Hedrich, Rainer
2012-10-01
Since the first recordings of single potassium channel activities in the plasma membrane of guard cells more than 25 years ago, patch-clamp studies discovered a variety of ion channels in all cell types and plant species under inspection. Their properties differed in a cell type- and cell membrane-dependent manner. Guard cells, for which the existence of plant potassium channels was initially documented, advanced to a versatile model system for studying plant ion channel structure, function, and physiology. Interestingly, one of the first identified potassium-channel genes encoding the Shaker-type channel KAT1 was shown to be highly expressed in guard cells. KAT1-type channels from Arabidopsis thaliana and its homologs from other species were found to encode the K(+)-selective inward rectifiers that had already been recorded in early patch-clamp studies with guard cells. Within the genome era, additional Arabidopsis Shaker-type channels appeared. All nine members of the Arabidopsis Shaker family are localized at the plasma membrane, where they either operate as inward rectifiers, outward rectifiers, weak voltage-dependent channels, or electrically silent, but modulatory subunits. The vacuole membrane, in contrast, harbors a set of two-pore K(+) channels. Just very recently, two plant anion channel families of the SLAC/SLAH and ALMT/QUAC type were identified. SLAC1/SLAH3 and QUAC1 are expressed in guard cells and mediate Slow- and Rapid-type anion currents, respectively, that are involved in volume and turgor regulation. Anion channels in guard cells and other plant cells are key targets within often complex signaling networks. Here, the present knowledge is reviewed for the plant ion channel biology. Special emphasis is drawn to the molecular mechanisms of channel regulation, in the context of model systems and in the light of evolution.
Physical data generation methodology for return-to-power steam line break analysis
Energy Technology Data Exchange (ETDEWEB)
Zee, Sung Kyun; Lee, Chung Chan; Lee, Chang Kue [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1996-02-01
Current methodology to generate physics data for steamline break accident analysis of CE-type nuclear plant such as Yonggwang Unit 3 is valid only if the core reactivity does not reach the criticality after shutdown. Therefore, the methodology requires tremendous amount of net scram worth, specially at the end of the cycle when moderator temperature coefficient is most negative. Therefore, we need a new methodology to obtain reasonably conservation physics data, when the reactor returns to power condition. Current methodology used ROCS which include only closed channel model. But it is well known that the closed channel model estimates the core reactivity too much negative if core flow rate is low. Therefore, a conservative methodology is presented which utilizes open channel 3D HERMITE model. Current methodology uses ROCS which include only closed channel model. But it is well known that the closed channel model estimates the core reactivity too much negative if core flow rate is low. Therefore, a conservative methodology is presented which utilizes open channel 3D HERMITE model. Return-to-power reactivity credit is produced to assist the reactivity table generated by closed channel model. Other data includes hot channel axial power shape, peaking factor and maximum quality for DNBR analysis. It also includes pin census for radiological consequence analysis. 48 figs., 22 tabs., 18 refs. (Author) .new.
Directory of Open Access Journals (Sweden)
Shlomo Shamai (Shitz
2009-01-01
Full Text Available This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom (s.d.o.f. are derived for the degraded case with one receiver. Schemes to achieve the s.d.o.f. for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable s.d.o.f. is given for the general case.
Directory of Open Access Journals (Sweden)
Kramer Gerhard
2009-01-01
Full Text Available Abstract This paper considers the compound wiretap channel, which generalizes Wyner's wiretap model to allow the channels to the (legitimate receiver and to the eavesdropper to take a number of possible states. No matter which states occur, the transmitter guarantees that the receiver decodes its message and that the eavesdropper is kept in full ignorance about the message. The compound wiretap channel can also be viewed as a multicast channel with multiple eavesdroppers, in which the transmitter sends information to all receivers and keeps the information secret from all eavesdroppers. For the discrete memoryless channel, lower and upper bounds on the secrecy capacity are derived. The secrecy capacity is established for the degraded channel and the semideterministic channel with one receiver. The parallel Gaussian channel is further studied. The secrecy capacity and the secrecy degree of freedom ( are derived for the degraded case with one receiver. Schemes to achieve the for the case with two receivers and two eavesdroppers are constructed to demonstrate the necessity of a prefix channel in encoder design. Finally, the multi-antenna (i.e., MIMO compound wiretap channel is studied. The secrecy capacity is established for the degraded case and an achievable is given for the general case.
Directory of Open Access Journals (Sweden)
Akiyuki Taruno
2018-03-01
Full Text Available Adenosine triphosphate (ATP has been well established as an important extracellular ligand of autocrine signaling, intercellular communication, and neurotransmission with numerous physiological and pathophysiological roles. In addition to the classical exocytosis, non-vesicular mechanisms of cellular ATP release have been demonstrated in many cell types. Although large and negatively charged ATP molecules cannot diffuse across the lipid bilayer of the plasma membrane, conductive ATP release from the cytosol into the extracellular space is possible through ATP-permeable channels. Such channels must possess two minimum qualifications for ATP permeation: anion permeability and a large ion-conducting pore. Currently, five groups of channels are acknowledged as ATP-release channels: connexin hemichannels, pannexin 1, calcium homeostasis modulator 1 (CALHM1, volume-regulated anion channels (VRACs, also known as volume-sensitive outwardly rectifying (VSOR anion channels, and maxi-anion channels (MACs. Recently, major breakthroughs have been made in the field by molecular identification of CALHM1 as the action potential-dependent ATP-release channel in taste bud cells, LRRC8s as components of VRACs, and SLCO2A1 as a core subunit of MACs. Here, the function and physiological roles of these five groups of ATP-release channels are summarized, along with a discussion on the future implications of understanding these channels.
Charged and Neutral Particles Channeling Phenomena Channeling 2008
Dabagov, Sultan B.; Palumbo, Luigi
2010-04-01
On the discovery of coherent Bremsstrahlung in a single crystal at the Frascati National Laboratories / C. Barbiellini, G. P. Murtas and S. B. Dabagov -- Advances in coherent Bremsstrahlung and LPM-effect studies (to the lOOth anniversary from the birth of L. D. Landau) / N. F. Shul'ga -- Spectra of radiation and created particles at intermediate energy in oriented crystal taking into account energy loss / V. N. Baier and V. M. Katkov -- The coherent Bremsstrahlung beam at MAX-lab facility / K. Fissum ... [et al.] -- Radiation from thin, structured targets (CERN NA63) / A. Dizdar -- Hard incoherent radiation in thick crystals / N. F. Shul'ga, V. V. Syshchenko and A. I. Tarnovsky -- Coherent Bremsstrahlung in periodically deformed crystals with a complex base / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Induction of coherent x-ray Bremsstrahlung in crystals under the influence of acoustic waves / A. R. Mkrtchyan and V. V. Parazian -- Coherent processes in bent single crystals / V. A. Maisheev -- Experimental and theoretical investigation of complete transfer phenomenon for media with various heat exchange coefficients / A. R. Mkrtchyan, A. E. Movsisyan and V. R. Kocharyan -- Coherent pair production in crystals / A. R. Mkrtchyan, A. A. Saharian and V. V. Parazian -- Negative particle planar and axial channeling and channeling collimation / R. A. Carrigan, Jr. -- CERN crystal-based collimation in modern hadron colliders / W. Scandale -- Studies and application of bent crystals for beam steering at 70 GeV IHEP accelerator / A. G. Afonin ... [et al.] -- Crystal collimation studies at the Tevatron (T-980) / N. V. Mokhov ... [et al.] -- Fabrication of crystals for channeling of particles in accellerators / A. Mazzolari ... [et al.] -- New possibilities to facilitate collimation of both positively and negatively charged particle beams by crystals / V. Guidi, A. Mazzolari and V. V. Tikhomirov -- Increase of probability of particle capture into the channeling
Directory of Open Access Journals (Sweden)
Szwast Maciej
2015-06-01
Full Text Available The paper presents the mathematical modelling of selected isothermal separation processes of gaseous mixtures, taking place in plants using membranes, in particular nonporous polymer membranes. The modelling concerns membrane modules consisting of two channels - the feeding and the permeate channels. Different shapes of the channels cross-section were taken into account. Consideration was given to co-current and counter-current flows, for feeding and permeate streams, respectively, flowing together with the inert gas receiving permeate. In the proposed mathematical model it was considered that pressure of gas changes along the length of flow channels was the result of both - the drop of pressure connected with flow resistance, and energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel. The literature on membrane technology takes into account only the drop of pressure connected with flow resistance. Consideration given to energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel constitute the essential novelty in the current study. The paper also presents results of calculations obtained by means of a computer program which used equations of the derived model. Physicochemical data concerning separation of the CO2/CH4 mixture with He as the sweep gas and data concerning properties of the membrane made of PDMS were assumed for calculations.
DEFF Research Database (Denmark)
Klausen, Thomas Kjær
of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...
International Nuclear Information System (INIS)
Tolmie, D.E.
1992-01-01
The High-Performance Parallel Interface (HIPPI) and Fibre Channel are near-gigabit per second data communications interfaces being developed in ANSI standards Task Group X3T9.3. HIPPI is the current interface of choice in the high-end and supercomputer arena, and Fibre Channel is a follow-on effort. HIPPI came from a local area network background, and Fibre Channel came from a mainframe to peripheral interface background
Nuclear reactor coolant channels
International Nuclear Information System (INIS)
Macbeth, R.V.
1978-01-01
Reference is made to coolant channels for pressurised water and boiling water reactors and the arrangement described aims to improve heat transfer between the fuel rods and the coolant. Baffle means extending axially within the channel are provided and disposed relative to the fuel rods so as to restrict flow oscillations occurring within the coolant from being propagated transversely to the axis of the channel. (UK)
New Channels, New Possibilities
DEFF Research Database (Denmark)
Pieterson, Willem; Ebbers, Wolfgang; Østergaard Madsen, Christian
2017-01-01
In this contribution we discuss the characteristics of what we call the fourth generation of public sector service channels: social robots. Based on a review of relevant literature we discuss their characteristics and place into multi-channel models of service delivery. We argue that social robots......-channel models of service delivery. This is especially relevant given the current lack of evaluations of such models, the broad range of channels available, and their different stages of deployment at governments around the world. Nevertheless, social robots offer an potentially very relevant addition...
... Certain calcium channel blockers interact with grapefruit products. Kaplan NM, et al. Treatment of hypertension: Drug therapy. In: Kaplan's Clinical Hypertension. 11th ed. Philadelphia, Pa.: Wolters Kluwer ...
International Nuclear Information System (INIS)
Gobbur, S.G.
1983-01-01
It is well understood that due to the wide band noise present in a nuclear analog-to-digital converter, events at the boundaries of adjacent channels are shared. It is a difficult and laborious process to exactly find out the shape of the channels at the boundaries. A simple scheme has been developed for the direct display of channel shape of any type of ADC on a cathode ray oscilliscope display. This has been accomplished by sequentially incrementing the reference voltage of a precision pulse generator by a fraction of a channel and storing ADC data in alternative memory locations of a multichannel pulse height analyser. Alternative channels are needed due to the sharing at the boundaries of channels. In the flat region of the profile alternate memory locations are channels with zero counts and channels with the full scale counts. At the boundaries all memory locations will have counts. The shape of this is a direct display of the channel boundaries. (orig.)
Conductance of Ion Channels - Theory vs. Experiment
Pohorille, Andrew; Wilson, Michael; Mijajlovic, Milan
2013-01-01
Transmembrane ion channels mediate a number of essential physiological processes in a cell ranging from regulating osmotic pressure to transmission of neural signals. Kinetics and selectivity of ion transport is of critical importance to a cell and, not surprisingly, it is a subject of numerous experimental and theoretical studies. In this presentation we will analyze in detail computer simulations of two simple channels from fungi - antiamoebin and trichotoxin. Each of these channels is made of an alpha-helical bundle of small, nongenomically synthesized peptides containing a number of rare amino acids and exhibits strong antimicrobial activity. We will focus on calculating ionic conductance defined as the ratio of ionic current through the channel to applied voltage. From molecular dynamics simulations, conductance can be calculated in at least two ways, each involving different approximations. Specifically, the current, given as the number of charges transferred through the channel per unit of time, can be obtained from the number of events in which ions cross the channel during the simulation. This method works well for large currents (high conductance values and/or applied voltages). If the number of crossing events is small, reliable estimates of current are difficult to achieve. Alternatively, conductance can be estimated assuming that ion transport can be well approximated as diffusion in the external potential given by the free energy profile. Then, the current can be calculated by solving the one-dimensional diffusion equation in this external potential and applied voltage (the generalized Nernst-Planck equation). To do so three ingredients are needed: the free energy profile, the position-dependent diffusion coefficient and the diffusive flux of ions into the channel. All these quantities can be obtained from molecular dynamics simulations. An important advantage of this method is that it can be used equally well to estimating large and small currents
Measuring Method for Lightning Channel Temperature
Li, X.; Zhang, J.; Chen, L.; Xue, Q.; Zhu, R.
2016-09-01
In this paper, we demonstrate the temperature of lightning channel utilizing the theory of lightning spectra and the model of local thermodynamic equilibrium (LTE). The impulse current generator platform (ICGS) was used to simulate the lightning discharge channel, and the spectral energy of infrared spectroscopy (930 nm) and the visible spectroscopy (648.2 nm) of the simulated lightning has been calculated. Results indicate that the peaks of luminous intensity of both infrared and visible spectra increase with the lightning current intensity in range of 5-50 kA. Based on the results, the temperature of the lightning channel is derived to be 6140.8-10424 K. Moreover, the temperature of the channel is approximately exponential to the lightning current intensity, which shows good agreement with that of the natural lightning cases.
Update of Part 61 impacts analysis methodology
International Nuclear Information System (INIS)
Oztunali, O.I.; Roles, G.W.
1986-01-01
The US Nuclear Regulatory Commission is expanding the impacts analysis methodology used during the development of the 10 CFR Part 61 rule to allow improved consideration of costs and impacts of disposal of waste that exceeds Class C concentrations. The project includes updating the computer codes that comprise the methodology, reviewing and updating data assumptions on waste streams and disposal technologies, and calculation of costs for small as well as large disposal facilities. This paper outlines work done to date on this project
Update of Part 61 impacts analysis methodology
International Nuclear Information System (INIS)
Oztunali, O.I.; Roles, G.W.; US Nuclear Regulatory Commission, Washington, DC 20555)
1985-01-01
The US Nuclear Regulatory Commission is expanding the impacts analysis methodology used during the development of the 10 CFR Part 61 regulation to allow improved consideration of costs and impacts of disposal of waste that exceeds Class C concentrations. The project includes updating the computer codes that comprise the methodology, reviewing and updating data assumptions on waste streams and disposal technologies, and calculation of costs for small as well as large disposal facilities. This paper outlines work done to date on this project
Critical voltage effects in electron channeling patterns
International Nuclear Information System (INIS)
Farrow, R.C.
1984-01-01
Electron channeling patterns were used to study critical voltage effects in the metals molybdenum and tungsten. The purpose was to characterize both theoretically and experimentally how a critical voltage will affect the channeling pattern line shapes. The study focused on the second order critical voltage that results from the degeneracy between the Bloch wave states of the (110) and (220) reflections. Theoretical (110) series electron channeling pattern line profiles were calculated using the dynamical theory of Hirsch and Humphreys (1970). A 10 beam dynamical electron diffraction calculation was performed (using complex Fourier lattice potentials) to generate Bloch wave coefficients, excitation amplitudes, and absorption coefficients needed for determining backscattering coefficients and subsequent backscattered electron intensities. The theoretical model is applicable to electron diffraction at all energies since no high energy approximation or perturbation method was used
USGS Methodology for Assessing Continuous Petroleum Resources
Charpentier, Ronald R.; Cook, Troy A.
2011-01-01
The U.S. Geological Survey (USGS) has developed a new quantitative methodology for assessing resources in continuous (unconventional) petroleum deposits. Continuous petroleum resources include shale gas, coalbed gas, and other oil and gas deposits in low-permeability ("tight") reservoirs. The methodology is based on an approach combining geologic understanding with well productivities. The methodology is probabilistic, with both input and output variables as probability distributions, and uses Monte Carlo simulation to calculate the estimates. The new methodology is an improvement of previous USGS methodologies in that it better accommodates the uncertainties in undrilled or minimally drilled deposits that must be assessed using analogs. The publication is a collection of PowerPoint slides with accompanying comments.
Effects of hypersonic field and anharmonic interactions on channelling radiation
International Nuclear Information System (INIS)
George, Juby; Pathak, Anand P; Goteti, L N S Prakash; Nagamani, G
2007-01-01
The effects of a hypersonic field on positron channelling radiation are considered. Anharmonic effects of the transverse potential induced by these longitudinal fields are incorporated and the wavefunction of the planar channelled positron is found by the solution of Dirac equation under the resonant influence of hypersound. An expression for the resonant frequency is estimated. The transition probabilities and the intensity of the channelling radiation are also calculated. It is found that the anharmonic effects change the spectral distributions considerably
Response Time Analysis and Test of Protection System Instrument Channels for APR1400 and OPR1000
International Nuclear Information System (INIS)
Lee, Chang Jae; Han, Seung; Yun, Jae Hee; Baek, Seung Min; Lee, Sang Jeong
2015-01-01
Safety limits are required to maintain the integrity of physical barriers designed to prevent the uncontrolled release of radioactive materials in nuclear power plants. The safety analysis establishes two critical constraints that include an analytical limit in terms of a measured or calculated variable, and a specific time after the analytical limit is reached to begin protective action. Keeping with the nuclear regulations and industry standards, satisfying these two requirements will ensure that the safety limit will not be exceeded during the design basis event, either an anticipated operational occurrence or a postulated accident. Various studies on the setpoint determination methodology for the safety-related instrumentation have been actively performed to ensure that the requirement of the analytical limit is satisfied. In particular, the protection setpoint methodology for the advanced power reactor 1400 (APP1400) and the optimized power reactor 1000 (OPR1000) has been recently developed to cover both the design basis event and the beyond design basis event. The developed setpoint methodology has also been quantitatively validated using specific computer programs and setpoint calculations. However, the safety of nuclear power plants cannot be fully guaranteed by satisfying the requirement of the analytical limit. In spite of the response time verification requirements of nuclear regulations and industry standards, it is hard to find the studies on the systematically integrated methodology regarding the response time evaluation. In cases of APR1400 and OPR1000, the response time analysis for the plant protection system is partially included in the setpoint calculation and the response time test is separately performed via the specific plant procedure. The test technique has a drawback which is the difficulty to demonstrate completeness of timing test. The analysis technique has also a demerit of resulting in extreme times that not actually possible. Thus
Response Time Analysis and Test of Protection System Instrument Channels for APR1400 and OPR1000
Energy Technology Data Exchange (ETDEWEB)
Lee, Chang Jae; Han, Seung; Yun, Jae Hee; Baek, Seung Min [Department of Instrumentation and Control System Engineering, KEPCO Engineering and Construction, Daejeon (Korea, Republic of); Lee, Sang Jeong [Department of Electronics Engineering, Chungnam National University, Daejeon (Korea, Republic of)
2015-07-01
Safety limits are required to maintain the integrity of physical barriers designed to prevent the uncontrolled release of radioactive materials in nuclear power plants. The safety analysis establishes two critical constraints that include an analytical limit in terms of a measured or calculated variable, and a specific time after the analytical limit is reached to begin protective action. Keeping with the nuclear regulations and industry standards, satisfying these two requirements will ensure that the safety limit will not be exceeded during the design basis event, either an anticipated operational occurrence or a postulated accident. Various studies on the setpoint determination methodology for the safety-related instrumentation have been actively performed to ensure that the requirement of the analytical limit is satisfied. In particular, the protection setpoint methodology for the advanced power reactor 1400 (APP1400) and the optimized power reactor 1000 (OPR1000) has been recently developed to cover both the design basis event and the beyond design basis event. The developed setpoint methodology has also been quantitatively validated using specific computer programs and setpoint calculations. However, the safety of nuclear power plants cannot be fully guaranteed by satisfying the requirement of the analytical limit. In spite of the response time verification requirements of nuclear regulations and industry standards, it is hard to find the studies on the systematically integrated methodology regarding the response time evaluation. In cases of APR1400 and OPR1000, the response time analysis for the plant protection system is partially included in the setpoint calculation and the response time test is separately performed via the specific plant procedure. The test technique has a drawback which is the difficulty to demonstrate completeness of timing test. The analysis technique has also a demerit of resulting in extreme times that not actually possible. Thus
Diffraction of radiation from channelled charged particles
International Nuclear Information System (INIS)
Baryshevskij, V.G.; Grubich, A.O.; Dubovskaya, I.Ya.
1978-01-01
An explicit expression for cross-section and radiation spectrum at diffraction is calculated. It is shown that photons emitted by channelled particles form a typical diffraction pattern which contains information about the crystal structure. It is also shown that the change of the longitudinal energy of the particle caused by the radiation braking becomes important when the particle energy is increased. (author)
Photovoltaic module energy rating methodology development
Energy Technology Data Exchange (ETDEWEB)
Kroposki, B.; Myers, D.; Emery, K.; Mrig, L. [National Renewable Energy Lab., Golden, CO (United States); Whitaker, C.; Newmiller, J. [Endecon Engineering, San Ramon, CA (United States)
1996-05-01
A consensus-based methodology to calculate the energy output of a PV module will be described in this paper. The methodology develops a simple measure of PV module performance that provides for a realistic estimate of how a module will perform in specific applications. The approach makes use of the weather data profiles that describe conditions throughout the United States and emphasizes performance differences between various module types. An industry-representative Technical Review Committee has been assembled to provide feedback and guidance on the strawman and final approach used in developing the methodology.
Sedimentary links between hillslopes and channels in a dryland basin
Hollings, R.
2016-12-01
The interface between hillslopes and channels is recognised as playing an important role in basin evolution and functioning. However, this interaction has not been described well in landscapes such as drylands, in which the diffuse process of runoff-driven sediment transport is important for sediment communication to the channel and to the basin outlet. This paper combines field measurements of surface sediment grain sizes in channels and on hillslopes with high resolution topography, >60 years of rainfall and runoff data from the Walnut Gulch Experimental Watershed (WGEW) in Arizona, and simple calculations of spatial stress distributions for various hydrologic scenarios to explore the potential for sediment to move from hillslopes to channels and through channels across the entire basin. Here we generalise the net movement of sediment in to or out of channel reaches, at high resolution in WGEW, as the balance between hillslope sediment supply to the channel and channel evacuation, in response to a variety of storms and discharge events. Our results show that downstream of small, unit source area watersheds, the balance in the channel often switches from being supply-dominated to being evacuation dominated for all scenarios. The low frequency but high discharge event in the channel seems to control the long term evolution of the channel, as stress is far greater for this scenario than other scenarios tested. The results draw on the high variability of rainfall characteristics to drive runoff events and so provides a physical explanation for long-term evolution of the channel network in drylands.
A numerical model for meltwater channel evolution in glaciers
Directory of Open Access Journals (Sweden)
A. H. Jarosch
2012-04-01
Full Text Available Meltwater channels form an integral part of the hydrological system of a glacier. Better understanding of how meltwater channels develop and evolve is required to fully comprehend supraglacial and englacial meltwater drainage. Incision of supraglacial stream channels and subsequent roof closure by ice deformation has been proposed in recent literature as a possible englacial conduit formation process. Field evidence for supraglacial stream incision has been found in Svalbard and Nepal. In Iceland, where volcanic activity provides meltwater with temperatures above 0 °C, rapid enlargement of supraglacial channels has been observed. Supraglacial channels provide meltwater through englacial passages to the subglacial hydrological systems of big ice sheets, which in turn affects ice sheet motion and their contribution to eustatic sea level change. By coupling, for the first time, a numerical ice dynamic model to a hydraulic model which includes heat transfer, we investigate the evolution of meltwater channels and their incision behaviour. We present results for different, constant meltwater fluxes, different channel slopes, different meltwater temperatures, different melt rate distributions in the channel as well as temporal variations in meltwater flux. The key parameters governing incision rate and depth are channel slope, meltwater temperature loss to the ice and meltwater flux. Channel width and geometry are controlled by melt rate distribution along the channel wall. Calculated Nusselt numbers suggest that turbulent mixing is the main heat transfer mechanism in the meltwater channels studied.
Scenario development methodologies
International Nuclear Information System (INIS)
Eng, T.; Hudson, J.; Stephansson, O.
1994-11-01
In the period 1981-1994, SKB has studied several methodologies to systematize and visualize all the features, events and processes (FEPs) that can influence a repository for radioactive waste in the future. All the work performed is based on the terminology and basic findings in the joint SKI/SKB work on scenario development presented in the SKB Technical Report 89-35. The methodologies studied are a) Event tree analysis, b) Influence diagrams and c) Rock Engineering Systems (RES) matrices. Each one of the methodologies is explained in this report as well as examples of applications. One chapter is devoted to a comparison between the two most promising methodologies, namely: Influence diagrams and the RES methodology. In conclusion a combination of parts of the Influence diagram and the RES methodology is likely to be a promising approach. 26 refs
Reliability Centered Maintenance - Methodologies
Kammerer, Catherine C.
2009-01-01
Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.
Kemperman, A.D.A.M.; van Delft, L.; Borgers, A.W.J.; Pantano, E.
2015-01-01
This chapter gives insight into consumers' online and offline fashion shopping behavior, consumers' omni-channel usage during the shopping process, and consumer fashion shopper segments. Based on a literature review, omni-channel shopping behavior during the shopping process was operationalized.
Directory of Open Access Journals (Sweden)
Kyong Oh Baek
2018-04-01
Full Text Available There are a number of methods for observing and estimating the transverse dispersion coefficient in an analysis of the solute transport in open channel flow. It may be difficult to select an optimal method to calculate dispersion coefficients from tracer data among numerous methodologies. A flowchart was proposed in this study to select an appropriate method under the transport situation of either time-variant or steady condition. When making the flowchart, the strengths and limitations of the methods were evaluated based on its derivation procedure which was conducted under specific assumptions. Additionally, application examples of these methods on experimental data were illustrated using previous works. Furthermore, the observed dispersion coefficients in a laboratory channel were validated by using transport numerical modeling, and the simulation results were compared with the experimental results from tracer tests. This flowchart may assist in choosing the better methods for determining the transverse dispersion coefficient in various river mixing situations.
International Nuclear Information System (INIS)
Seidman, A.; Avrahami, Z.; Sheinfux, B.; Grinberg, J.
1976-01-01
A channel electron multiplier is described having a tubular wall coated with a secondary-electron emitting material and including an electric field for accelerating the electrons, the electric field comprising a plurality of low-resistive conductive rings each alternating with a high-resistive insulating ring. The thickness of the low-resistive rings is many times larger than that of the high-resistive rings, being in the order of tens of microns for the low-resistive rings and at least one order of magnitude lower for the high-resistive rings; and the diameter of the channel tubular walls is also many times larger than the thickness of the high-resistive rings. Both single-channel and multiple-channel electron multipliers are described. A very important advantage, particularly in making multiple-channel multipliers, is the simplicity of the procedure that may be used in constructing such multipliers. Other operational advantages are described
Cardiac potassium channel subtypes
DEFF Research Database (Denmark)
Schmitt, Nicole; Grunnet, Morten; Olesen, Søren-Peter
2014-01-01
About 10 distinct potassium channels in the heart are involved in shaping the action potential. Some of the K(+) channels are primarily responsible for early repolarization, whereas others drive late repolarization and still others are open throughout the cardiac cycle. Three main K(+) channels...... drive the late repolarization of the ventricle with some redundancy, and in atria this repolarization reserve is supplemented by the fairly atrial-specific KV1.5, Kir3, KCa, and K2P channels. The role of the latter two subtypes in atria is currently being clarified, and several findings indicate...... that they could constitute targets for new pharmacological treatment of atrial fibrillation. The interplay between the different K(+) channel subtypes in both atria and ventricle is dynamic, and a significant up- and downregulation occurs in disease states such as atrial fibrillation or heart failure...
DEFF Research Database (Denmark)
Wanitchakool, Podchanart; Ousingsawat, Jiraporn; Sirianant, Lalida
2016-01-01
A remarkable feature of apoptosis is the initial massive cell shrinkage, which requires opening of ion channels to allow release of K(+), Cl(-), and organic osmolytes to drive osmotic water movement and cell shrinkage. This article focuses on the role of the Cl(-) channels LRRC8, TMEM16/anoctamin......, and cystic fibrosis transmembrane conductance regulator (CFTR) in cellular apoptosis. LRRC8A-E has been identified as a volume-regulated anion channel expressed in many cell types. It was shown to be required for regulatory and apoptotic volume decrease (RVD, AVD) in cultured cell lines. Its presence also......(-) channels or as regulators of other apoptotic Cl(-) channels, such as LRRC8. CFTR has been known for its proapoptotic effects for some time, and this effect may be based on glutathione release from the cell and increase in cytosolic reactive oxygen species (ROS). Although we find that CFTR is activated...
DEFF Research Database (Denmark)
2015-01-01
A method includes determining a sequence of first coefficient estimates of a communication channel based on a sequence of pilots arranged according to a known pilot pattern and based on a receive signal, wherein the receive signal is based on the sequence of pilots transmitted over the communicat......A method includes determining a sequence of first coefficient estimates of a communication channel based on a sequence of pilots arranged according to a known pilot pattern and based on a receive signal, wherein the receive signal is based on the sequence of pilots transmitted over...... the communication channel. The method further includes determining a sequence of second coefficient estimates of the communication channel based on a decomposition of the first coefficient estimates in a dictionary matrix and a sparse vector of the second coefficient estimates, the dictionary matrix including...... filter characteristics of at least one known transceiver filter arranged in the communication channel....
Fluid and solute transport in a network of channels
International Nuclear Information System (INIS)
Moreno, L.; Neretnieks, I.
1991-09-01
A three-dimensional channel network model is presented. The fluid flow and solute transport are assumed to take place through a network of connected channels. The channels are generated assuming that the conductances are lognormally distributed. The flow is calculated resolving the pressure distribution and the sole transport is calculated by using a particle tracking technique. The model includes diffusion into the rock matrix and sorption within the matrix in addition to advection along the channel network. Different approaches are used to describe the channel volume and its relation to the conductivity. To quantify the diffusion into the rock matrix the size of the flow wetted surface (contact surface between the channel and the rock) is needed in addition to the diffusion properties and the sorption capacity of the rock. Two different geometries were simulated: regional parallel flow and convergent flow toward a tunnel. In the generation of the channel network, it is found that its connectivity is reduced when the standard deviation in conductances is increased. For large standard deviations, the water conducting channels are found to be few. Standard deviations for the distribution of the effluent channel flowrates were calculated. Comparisons were made with experimental data from drifts and tunnels as well as boreholes as a means to validate the model. (au) (31 refs.)
Residual radioactive material guidelines: Methodology and applications
International Nuclear Information System (INIS)
Yu, C.; Yuan, Y.C.; Zielen, A.J.; Wallo, A. III.
1989-01-01
A methodology to calculate residual radioactive material guidelines was developed for the US Department of Energy (DOE). This methodology is coded in a menu-driven computer program, RESRAD, which can be run on IBM or IBM-compatible microcomputers. Seven pathways of exposure are considered: external radiation, inhalation, and ingestion of plant foods, meat, milk, aquatic foods, and water. The RESRAD code has been applied to several DOE sites to calculate soil cleanup guidelines. This experience has shown that the computer code is easy to use and very user-friendly. 3 refs., 8 figs
Computation of gradually varied flow in compound open channel ...
Indian Academy of Sciences (India)
The flow of water in an open channel can be treated as steady, gradually varied flow for ... channel between two nodes is treated as a single reach to calculate the loss ... dition at control points and (iii) critical depth is also required to verify the ...
Cluster-cell calculation using the method of generalized homogenization
International Nuclear Information System (INIS)
Laletin, N.I.; Boyarinov, V.F.
1988-01-01
The generalized-homogenization method (GHM), used for solving the neutron transfer equation, was applied to calculating the neutron distribution in the cluster cell with a series of cylindrical cells with cylindrically coaxial zones. Single-group calculations of the technological channel of the cell of an RBMK reactor were performed using GHM. The technological channel was understood to be the reactor channel, comprised of the zirconium rod, the water or steam-water mixture, the uranium dioxide fuel element, and the zirconium tube, together with the adjacent graphite layer. Calculations were performed for channels with no internal sources and with unit incoming current at the external boundary as well as for channels with internal sources and zero current at the external boundary. The PRAKTINETs program was used to calculate the symmetric neutron distributions in the microcell and in channels with homogenized annular zones. The ORAR-TsM program was used to calculate the antisymmetric distribution in the microcell. The accuracy of the calculations were compared for the two channel versions
Benchmark calculation of subchannel analysis codes
International Nuclear Information System (INIS)
1996-02-01
In order to evaluate the analysis capabilities of various subchannel codes used in thermal-hydraulic design of light water reactors, benchmark calculations were performed. The selected benchmark problems and major findings obtained by the calculations were as follows: (1)As for single-phase flow mixing experiments between two channels, the calculated results of water temperature distribution along the flow direction were agreed with experimental results by tuning turbulent mixing coefficients properly. However, the effect of gap width observed in the experiments could not be predicted by the subchannel codes. (2)As for two-phase flow mixing experiments between two channels, in high water flow rate cases, the calculated distributions of air and water flows in each channel were well agreed with the experimental results. In low water flow cases, on the other hand, the air mixing rates were underestimated. (3)As for two-phase flow mixing experiments among multi-channels, the calculated mass velocities at channel exit under steady-state condition were agreed with experimental values within about 10%. However, the predictive errors of exit qualities were as high as 30%. (4)As for critical heat flux(CHF) experiments, two different results were obtained. A code indicated that the calculated CHF's using KfK or EPRI correlations were well agreed with the experimental results, while another code suggested that the CHF's were well predicted by using WSC-2 correlation or Weisman-Pei mechanistic model. (5)As for droplets entrainment and deposition experiments, it was indicated that the predictive capability was significantly increased by improving correlations. On the other hand, a remarkable discrepancy between codes was observed. That is, a code underestimated the droplet flow rate and overestimated the liquid film flow rate in high quality cases, while another code overestimated the droplet flow rate and underestimated the liquid film flow rate in low quality cases. (J.P.N.)
LOOP-3, Hydraulic Stability in Heated Parallel Channels
Energy Technology Data Exchange (ETDEWEB)
Davies, A L [AEEW, Dorset (United Kingdom)
1968-02-01
1 - Nature of physical problem solved: Hydraulic stability in parallel channels. 2 - Method of solution: Calculation of transfer functions developed in reference (10 below). 3 - Restrictions on the complexity of the problem: Only due to assumptions in analysis (see ref.)
Energy Technology Data Exchange (ETDEWEB)
Stojadinovic, A; Pop-Jordanov, J; Zivkovic, Z [The Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)
1964-07-01
For calculating the reactivity in the reactor channel, it was estimated that there is a linear increase of the neutron temperature along the channel. The channel is divide into 5 regions. Reactivity of the channel was calculated by using the reactivity curves for each region. it has been compared to the reactivity values obtained for different mean temperature values. The calculations were done on the digital computer Zuse-Z-23.
Parameters calculation of shielding experiment
International Nuclear Information System (INIS)
Gavazza, S.
1986-02-01
The radiation transport methodology comparing the calculated reactions and dose rates for neutrons and gama-rays, with experimental measurements obtained on iron shield, irradiated in the YAYOI reactor is evaluated. The ENDF/B-IV and VITAMIN-C libraries and the AMPX-II modular system, for cross sections generation collapsed by the ANISN code were used. The transport calculations were made using the DOT 3.5 code, adjusting the boundary iron shield source spectrum to the reactions and dose rates, measured at the beginning of shield. The neutron and gamma ray distributions calculated on the iron shield presented reasonable agreement with experimental measurements. An experimental arrangement using the IEA-R1 reactor to determine a shielding benchmark is proposed. (Author) [pt
The Technique to Prevent the Data Leakage using Covert Channels
Directory of Open Access Journals (Sweden)
Anna Vasilievna Arkhangelskaya
2013-12-01
Full Text Available The purpose of the article was to analyze technique to prevent information leakage using covert channels. The main steps are as follows: involving covert channels identification, data throughput estimation, its elimination or limitation, audit and detection. Three schemes of identification had been analyzed: shared resources methodology, covert flow tree method, message sequence diagram method. Ways of guarantee information delivery from systems with low security level to systems with high security level have been investigated.
Korzekwa, Kamil; Czachórski, Stanisław; Puchała, Zbigniew; Życzkowski, Karol
2018-04-01
Is it always possible to explain random stochastic transitions between states of a finite-dimensional system as arising from the deterministic quantum evolution of the system? If not, then what is the minimal amount of randomness required by quantum theory to explain a given stochastic process? Here, we address this problem by studying possible coherifications of a quantum channel Φ, i.e., we look for channels {{{Φ }}}{ \\mathcal C } that induce the same classical transitions T, but are ‘more coherent’. To quantify the coherence of a channel Φ we measure the coherence of the corresponding Jamiołkowski state J Φ. We show that the classical transition matrix T can be coherified to reversible unitary dynamics if and only if T is unistochastic. Otherwise the Jamiołkowski state {J}{{Φ }}{ \\mathcal C } of the optimally coherified channel is mixed, and the dynamics must necessarily be irreversible. To assess the extent to which an optimal process {{{Φ }}}{ \\mathcal C } is indeterministic we find explicit bounds on the entropy and purity of {J}{{Φ }}{ \\mathcal C }, and relate the latter to the unitarity of {{{Φ }}}{ \\mathcal C }. We also find optimal coherifications for several classes of channels, including all one-qubit channels. Finally, we provide a non-optimal coherification procedure that works for an arbitrary channel Φ and reduces its rank (the minimal number of required Kraus operators) from {d}2 to d.
CANDU channel flow verification
International Nuclear Information System (INIS)
Mazalu, N.; Negut, Gh.
1997-01-01
The purpose of this evaluation was to obtain accurate information on each channel flow that enables us to assess precisely the level of reactor thermal power and, for reasons of safety, to establish which channel is boiling. In order to assess the channel flow parameters, computer simulations were done with the NUCIRC code and the results were checked by measurements. The complete channel flow measurements were made in the zero power cold condition. In hot conditions there were made flow measurements using the Shut Down System 1 (SDS 1) flow devices from 0.1 % F.P. up to 100 % F.P. The NUCIRC prediction for CANDU channel flows and the measurements by Ultrasonic Flow Meter at zero power cold conditions and SDS 1 flow channel measurements at different reactor power levels showed an acceptable agreement. The 100 % F.P. average errors for channel flow of R, shows that suitable NUCIRC flow assessment can be made. So, it can be done a fair prediction of the reactor power distribution. NUCIRC can predict accurately the onset of boiling and helps to warn at the possible power instabilities at high powers or it can detect the flow blockages. The thermal hydraulic analyst has in NUCIRC a suitable tool to do accurate predictions for the thermal hydraulic parameters for different steady state power levels which subsequently leads to an optimal CANDU reactor operation. (authors)
Introduction to LCA Methodology
DEFF Research Database (Denmark)
Hauschild, Michael Z.
2018-01-01
In order to offer the reader an overview of the LCA methodology in the preparation of the more detailed description of its different phases, a brief introduction is given to the methodological framework according to the ISO 14040 standard and the main elements of each of its phases. Emphasis...
Methodologies, languages and tools
International Nuclear Information System (INIS)
Amako, Katsuya
1994-01-01
This is a summary of the open-quotes Methodologies, Languages and Toolsclose quotes session in the CHEP'94 conference. All the contributions to methodologies and languages are relevant to the object-oriented approach. Other topics presented are related to various software tools in the down-sized computing environment
Archetype modeling methodology.
Moner, David; Maldonado, José Alberto; Robles, Montserrat
2018-03-01
Clinical Information Models (CIMs) expressed as archetypes play an essential role in the design and development of current Electronic Health Record (EHR) information structures. Although there exist many experiences about using archetypes in the literature, a comprehensive and formal methodology for archetype modeling does not exist. Having a modeling methodology is essential to develop quality archetypes, in order to guide the development of EHR systems and to allow the semantic interoperability of health data. In this work, an archetype modeling methodology is proposed. This paper describes its phases, the inputs and outputs of each phase, and the involved participants and tools. It also includes the description of the possible strategies to organize the modeling process. The proposed methodology is inspired by existing best practices of CIMs, software and ontology development. The methodology has been applied and evaluated in regional and national EHR projects. The application of the methodology provided useful feedback and improvements, and confirmed its advantages. The conclusion of this work is that having a formal methodology for archetype development facilitates the definition and adoption of interoperable archetypes, improves their quality, and facilitates their reuse among different information systems and EHR projects. Moreover, the proposed methodology can be also a reference for CIMs development using any other formalism. Copyright © 2018 Elsevier Inc. All rights reserved.
Menopause and Methodological Doubt
Spence, Sheila
2005-01-01
Menopause and methodological doubt begins by making a tongue-in-cheek comparison between Descartes' methodological doubt and the self-doubt that can arise around menopause. A hermeneutic approach is taken in which Cartesian dualism and its implications for the way women are viewed in society are examined, both through the experiences of women…
VEM: Virtual Enterprise Methodology
DEFF Research Database (Denmark)
Tølle, Martin; Vesterager, Johan
2003-01-01
This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works...
Data Centric Development Methodology
Khoury, Fadi E.
2012-01-01
Data centric applications, an important effort of software development in large organizations, have been mostly adopting a software methodology, such as a waterfall or Rational Unified Process, as the framework for its development. These methodologies could work on structural, procedural, or object oriented based applications, but fails to capture…
Carter, Susan
2014-01-01
Arts/Humanities researchers frequently do not explain methodology overtly; instead, they "perform" it through their use of language, textual and historic cross-reference, and theory. Here, methodologies from literary studies are shown to add to Higher Education (HE) an exegetical and critically pluralist approach. This includes…
Near-membrane dynamics and capture of TRPM8 channels within transient confinement domains.
Directory of Open Access Journals (Sweden)
Luis A Veliz
Full Text Available BACKGROUND: The cold and menthol receptor, TRPM8, is a non-selective cation channel expressed in a subset of peripheral neurons that is responsible for neuronal detection of environmental cold stimuli. It was previously shown that members of the transient receptor potential (TRP family of ion channels are translocated toward the plasma membrane (PM in response to agonist stimulation. Because the spatial and temporal dynamics of cold receptor cell-surface residence may determine neuronal activity, we hypothesized that the movement of TRPM8 to and from the PM might be a regulated process. Single particle tracking (SPT is a useful tool for probing the organization and dynamics of protein constituents in the plasma membrane. METHODOLOGY/PRINCIPAL FINDINGS: We used SPT to study the receptor dynamics and describe membrane/near-membrane behavior of particles containing TRPM8-EGFP in transfected HEK-293T and F-11 cells. Cells were imaged using total internal reflection fluorescence (TIRF microscopy and the 2D and 3D trajectories of TRPM8 molecules were calculated by analyzing mean-square particle displacement against time. Four characteristic types of motion were observed: stationary mode, simple Brownian diffusion, directed motion, and confined diffusion. In the absence of cold or menthol to activate the channel, most TRPM8 particles move in network covering the PM, periodically lingering for 2-8 s in confined microdomains of about 800 nm radius. Removing cholesterol with methyl-beta-cyclodextrin (MβCD stabilizes TRPM8 motion in the PM and is correlated with larger TRPM8 current amplitude that results from an increase in the number of available channels without a change in open probability. CONCLUSIONS/SIGNIFICANCE: These results reveal a novel mechanism for regulating TRPM8 channel activity, and suggest that PM dynamics may play an important role in controlling electrical activity in cold-sensitive neurons.
Reconfigurable virtual electrowetting channels.
Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian
2012-02-21
Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.
Reliability assessment of PARR-1 renovated I and C system startup channel-b
Energy Technology Data Exchange (ETDEWEB)
Qamar, M.A.; Habib, M.A.; Iqbal, M.
1991-11-20
The report covers the reliability assessment of the startup channel-B of the PARR-1 renovated instrumentation and Control. For startup channel-A, a separate report (DNSRP-10(7)/88) was prepared in 1988. As the modules are of different origins in both the channels, a separate calculation was necessary. In the report the overall unreliability of the startup channel has been calculated by considering 1 out of 2 operation mode. In the assessment, the reliability calculations for the channel has been performed using similar assumptions as used in the authors' report on startup channel-A. For the analysis the Component Count Method (CCM) was applied. Comparison of results for channel-A and channel-B were made.
Evaluation channel performance in multichannel environments
Gensler, S.; Dekimpe, M.; Skiera, B.
2007-01-01
Evaluating channel performance is crucial for actively managing multiple sales channels, and requires understanding the customers' channel preferences. Two key components of channel performance are (i) the existing customers' intrinsic loyalty to a particular channel and (ii) the channel's ability
Channel follower leakage restrictor
International Nuclear Information System (INIS)
Williamson, H.E.; Smith, B.A.
1977-01-01
An improved means is provided to control coolant leakage between the flow channel and the lower tie plate of a nuclear fuel assembly. The means includes an opening in the lower tie plate and a movable element adjacent thereto. The coolant pressure within the tie plate biases the movable means toward the inner surface of the surrounding flow channel to compensate for any movement of the flow channel away from the lower tie plate to thereby control the leakage of coolant flow from the fuel assemblies to the spaces among the fuel assemblies of the core. 9 figures
On conduction in a bacterial sodium channel.
Directory of Open Access Journals (Sweden)
Simone Furini
Full Text Available Voltage-gated Na⁺-channels are transmembrane proteins that are responsible for the fast depolarizing phase of the action potential in nerve and muscular cells. Selective permeability of Na⁺ over Ca²⁺ or K⁺ ions is essential for the biological function of Na⁺-channels. After the emergence of the first high-resolution structure of a Na⁺-channel, an anionic coordination site was proposed to confer Na⁺ selectivity through partial dehydration of Na⁺ via its direct interaction with conserved glutamate side chains. By combining molecular dynamics simulations and free-energy calculations, a low-energy permeation pathway for Na⁺ ion translocation through the selectivity filter of the recently determined crystal structure of a prokaryotic sodium channel from Arcobacter butzleri is characterised. The picture that emerges is that of a pore preferentially occupied by two ions, which can switch between different configurations by crossing low free-energy barriers. In contrast to K⁺-channels, the movements of the ions appear to be weakly coupled in Na⁺-channels. When the free-energy maps for Na⁺ and K⁺ ions are compared, a selective site is characterised in the narrowest region of the filter, where a hydrated Na⁺ ion, and not a hydrated K⁺ ion, is energetically stable.
Direct channel problems and phenomena
International Nuclear Information System (INIS)
Cutkosky, R.E.
1975-01-01
Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena
Spatial variability of correlated color temperature of lightning channels
Directory of Open Access Journals (Sweden)
Nobuaki Shimoji
Full Text Available In this paper, we present the spatial variability of the correlated color temperature of lightning channel shown in a digital still image. In order to analyze the correlated color temperature, we calculated chromaticity coordinates of the lightning channels in the digital still image. From results, the spatial variation of the correlated color temperature of the lightning channel was confirmed. Moreover, the results suggest that the correlated color temperature and peak current of the lightning channels are related to each other. Keywords: Lightning, Color analysis, Correlated color temperature, Chromaticity coordinate, CIE 1931 xy-chromaticity diagram
Heat transfer with a split water channel
International Nuclear Information System (INIS)
Krinsky, S.
1978-01-01
The heat transfer problem associated with the incidence of synchrotron radiation upon a vacuum chamber wall cooled by a single water channel was previously studied, and a numerical solution to the potential problem was found using the two-dimensional magnet program POISSON. Calculations were extended to consider the case of a split water channel using POISSON to solve the potential problem for a given choice of parameters. By optimizing the dimensions, boiling of the water can be avoided. A copper chamber is a viable solution to the heat transfer problem at a beam port
Observation of diffraction effects in positron channeling
International Nuclear Information System (INIS)
Palathingal, J.C.; Peng, J.P.; Lynn, K.G.; Wu, X.Y.; Schultz, P.J.
1994-01-01
An experimental investigation of positron channeling was made with a high-angular resolution apparatus, employing positrons of kinetic energy 1 MeV, derived from the Brookhaven National Laboratory Dynamitron. The pattern of transmission through a Si (100) single crystal of thickness 0.245 μm was investigated for a number of major planes. The authors have observed for the first time, in excellent detail, the fine structure of the channeling pattern expected to arise from the particle diffraction effects, theoretically explainable in terms of the quantum-mechanical many-beam calculations
Many channel spectrum unfolding
International Nuclear Information System (INIS)
Najzer, M.; Glumac, B.; Pauko, M.
1980-01-01
The principle of the ITER unfolding code as used for the many channel spectrum unfolding is described. Its unfolding ability is tested on seven typical neutron spectra. The effect of the initial spectrum approximation upon the solution is discussed
Iowa State University GIS Support and Research Facility — This draft dataset consists of all ditches or channelized pieces of stream that could be identified using three input datasets; namely the1:24,000 National...
Djordjevic, Ivan; Vasic, Bane
2010-01-01
This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.
Martinac, Boris
2008-01-01
All living cells are able to detect and translate environmental stimuli into biologically meaningful signals. Sensations of touch, hearing, sight, taste, smell or pain are essential to the survival of all living organisms. The importance of sensory input for the existence of life thus justifies the effort made to understand its molecular origins. Sensing with Ion Channels focuses on ion channels as key molecules enabling biological systems to sense and process the physical and chemical stimuli that act upon cells in their living environment. Its aim is to serve as a reference to ion channel specialists and as a source of new information to non specialists who want to learn about the structural and functional diversity of ion channels and their role in sensory physiology.
Calcium channel blocker poisoning
Directory of Open Access Journals (Sweden)
Miran Brvar
2005-04-01
Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.
DEFF Research Database (Denmark)
Pedersen, Stine Falsig; Owsianik, Grzegorz; Nilius, Bernd
2005-01-01
The TRP ("transient receptor potential") family of ion channels now comprises more than 30 cation channels, most of which are permeable for Ca2+, and some also for Mg2+. On the basis of sequence homology, the TRP family can be divided in seven main subfamilies: the TRPC ('Canonical') family......, the TRPV ('Vanilloid') family, the TRPM ('Melastatin') family, the TRPP ('Polycystin') family, the TRPML ('Mucolipin') family, the TRPA ('Ankyrin') family, and the TRPN ('NOMPC') family. The cloning and characterization of members of this cation channel family has exploded during recent years, leading...... to a plethora of data on the roles of TRPs in a variety of tissues and species, including mammals, insects, and yeast. The present review summarizes the most pertinent recent evidence regarding the structural and functional properties of TRP channels, focusing on the regulation and physiology of mammalian TRPs....
Authentication over Noisy Channels
Lai, Lifeng; Gamal, Hesham El; Poor, H. Vincent
2008-01-01
In this work, message authentication over noisy channels is studied. The model developed in this paper is the authentication theory counterpart of Wyner's wiretap channel model. Two types of opponent attacks, namely impersonation attacks and substitution attacks, are investigated for both single message and multiple message authentication scenarios. For each scenario, information theoretic lower and upper bounds on the opponent's success probability are derived. Remarkably, in both scenarios,...
DEFF Research Database (Denmark)
Gale, A.S.; Surlyk, Finn; Anderskouv, Kresten
2013-01-01
Evidence from regional stratigraphical patterns in Santonian−Campanian chalk is used to infer the presence of a very broad channel system (5 km across) with a depth of at least 50 m, running NNW−SSE across the eastern Isle of Wight; only the western part of the channel wall and fill is exposed. W......−Campanian chalks in the eastern Isle of Wight, involving penecontemporaneous tectonic inversion of the underlying basement structure, are rejected....
1981-04-01
Cycles of wetting and drying are also t ,v itiue swelling and shrinkage of the soil. S 11ied blocks or peds of soil fabric ,,ks. id downslope soil creep ...hydrographs of water and sediment at the point in question. By feeding the output from the hydrology-transport model into the finite element model...the banks as undercut banks fail. Channel irregularities such as seepage zones, cattle crossings, overbank drainage, buried channels, organic deposits
Energy Technology Data Exchange (ETDEWEB)
Bolotin, IU L; Gonchar, V IU; Truten, V I; Shulga, N F
1986-01-01
It is shown that axial channeling of relativistic electrons can give rise to the effect of dynamic chaos which involves essentially chaotic motion of a particle in the channel. The conditions leading to the effect of dynamic chaos and the manifestations of this effect in physical processes associated with the passage of particles through a crystal are examined using a silicon crystal as an example. 7 references.
Quasi-equilibrium channel model of an constant current arc
Directory of Open Access Journals (Sweden)
Gerasimov Alexander V.
2003-01-01
Full Text Available The rather simple method of calculation of electronic and gas temperature in the channel of arc of plasma generator is offered. This method is based on self-consistent two-temperature channel model of an electric arc. The method proposed enables to obtain radial allocation of gas and electronic temperatures in a non-conducting zone of an constant current arc, for prescribed parameters of discharge (current intensity and power of the discharge, with enough good precision. The results obtained can be used in model and engineering calculations to estimate gas and electronic temperatures in the channel of an arc plasma generator.
The method of calculation of pipelines laid on supports
Benin D.M.
2017-01-01
this article focuses on the issue of laying pipelines on supports and the method of calculation of vertical and horizontal loads acting on the support. As pipelines can be water piping systems, heat networks, oil and mazout lines, condensate lines, steam lines, etc. this article describes the calculations of supports for pipelines laid above ground, in crowded channels, premises, on racks, in impassable channels, hanging supports, etc. The paper explores recommendations for placement of the s...
International Nuclear Information System (INIS)
Falero, B.; Bueno, P.; Chaves, M. A.; Ordiales, J. M.; Villafana, O.; Gonzalez, M. J.
2013-01-01
The aim of this study was to develop a software application that performs calculation shields in radiology room depending on the type of equipment. The calculation will be done by selecting the user, the method proposed in the Guide 5.11, the Report 144 and 147 and also for the methodology given by the Portuguese Health Ministry. (Author)
Pressurized water reactor fuel rod design methodology
International Nuclear Information System (INIS)
Silva, A.T.; Esteves, A.M.
1988-08-01
The fuel performance program FRAPCON-1 and the structural finite element program SAP-IV are applied in a pressurized water reactor fuel rod design methodology. The applied calculation procedure allows to dimension the fuel rod components and characterize its internal pressure. (author) [pt
International Nuclear Information System (INIS)
Rossi, Pedro Carlos Russo
2011-01-01
This work presents a study of high energy nuclear reactions which are fundamental to dene the source term in accelerator driven systems. These nuclear reactions, also known as spallation, consist in the interaction of high energetic hadrons with nucleons in the atomic nucleus. The phenomenology of these reactions consist in two step. In the rst, the proton interacts through multiple scattering in a process called intra-nuclear cascade. It is followed by a step in which the excited nucleus, coming from the intranuclear cascade, could either, evaporates particles to achieve a moderate energy state or fission. This process is known as competition between evaporation and fission. In this work the main nuclear models, Bertini and Cugnon are reviewed, since these models are fundamental for design purposes of the source term in ADS, due to lack of evaluated nuclear data for these reactions. The implementation and validation of the calculation methods for the design of the source is carried out to implement the methodology of source design using the program MCNPX (Monte Carlo N-Particle eXtended), devoted to calculation of transport of these particles and the validation performed by an international cooperation together with a Coordinated Research Project (CRP) of the International Atomic Energy Agency and available jobs, in order to qualify the calculations on nuclear reactions and the de-excitation channels involved, providing a state of the art of design and methodology for calculating external sources of spallation for source driven systems. The CRISP, is a brazilian code for the phenomenological description of the reactions involved and the models implemented in the code were reviewed and improved to continue the qualification process. Due to failure of the main models in describing the production of light nuclides, the multifragmentation reaction model was studied. Because the discrepancies in the calculations of production of these nuclides are attributes to the
T. E. Lisle; J. M. Nelson; B. L. Barkett; J. Pitlick; M. A. Madej
1998-01-01
Recent laboratory experiments have shown that bed mobility in gravel bed channels responds to changes in sediment supply, but detailed examinations of this adjustment in natural channels have been lacking, and practical methodologies to measure bed mobility have not been tested. We examined six gravel-bed, alternate-bar channels which have a wide range in annual...
Radiation damage calculations for compound materials
International Nuclear Information System (INIS)
Greenwood, L.R.
1990-01-01
This paper reports on the SPECOMP computer code, developed to calculate neutron-induced displacement damage cross sections for compound materials such as alloys, insulators, and ceramic tritium breeders for fusion reactors. These new calculations rely on recoil atom energy distributions previously computed with the DISCS computer code, the results of which are stored in SPECTER computer code master libraries. All reaction channels were considered in the DISCS calculations and the neutron cross sections were taken from ENDF/B-V. Compound damage calculations with SPECOMP thus do not need to perform any recoil atom calculations and consequently need no access to ENDF or other neutron data bases. The calculations proceed by determining secondary displacements for each combination of recoil atom and matrix atom using the Lindhard partition of the recoil energy to establish the damage energy
Low-Complexity Bayesian Estimation of Cluster-Sparse Channels
Ballal, Tarig; Al-Naffouri, Tareq Y.; Ahmed, Syed
2015-01-01
This paper addresses the problem of channel impulse response estimation for cluster-sparse channels under the Bayesian estimation framework. We develop a novel low-complexity minimum mean squared error (MMSE) estimator by exploiting the sparsity of the received signal profile and the structure of the measurement matrix. It is shown that due to the banded Toeplitz/circulant structure of the measurement matrix, a channel impulse response, such as underwater acoustic channel impulse responses, can be partitioned into a number of orthogonal or approximately orthogonal clusters. The orthogonal clusters, the sparsity of the channel impulse response and the structure of the measurement matrix, all combined, result in a computationally superior realization of the MMSE channel estimator. The MMSE estimator calculations boil down to simpler in-cluster calculations that can be reused in different clusters. The reduction in computational complexity allows for a more accurate implementation of the MMSE estimator. The proposed approach is tested using synthetic Gaussian channels, as well as simulated underwater acoustic channels. Symbol-error-rate performance and computation time confirm the superiority of the proposed method compared to selected benchmark methods in systems with preamble-based training signals transmitted over clustersparse channels.
Low-Complexity Bayesian Estimation of Cluster-Sparse Channels
Ballal, Tarig
2015-09-18
This paper addresses the problem of channel impulse response estimation for cluster-sparse channels under the Bayesian estimation framework. We develop a novel low-complexity minimum mean squared error (MMSE) estimator by exploiting the sparsity of the received signal profile and the structure of the measurement matrix. It is shown that due to the banded Toeplitz/circulant structure of the measurement matrix, a channel impulse response, such as underwater acoustic channel impulse responses, can be partitioned into a number of orthogonal or approximately orthogonal clusters. The orthogonal clusters, the sparsity of the channel impulse response and the structure of the measurement matrix, all combined, result in a computationally superior realization of the MMSE channel estimator. The MMSE estimator calculations boil down to simpler in-cluster calculations that can be reused in different clusters. The reduction in computational complexity allows for a more accurate implementation of the MMSE estimator. The proposed approach is tested using synthetic Gaussian channels, as well as simulated underwater acoustic channels. Symbol-error-rate performance and computation time confirm the superiority of the proposed method compared to selected benchmark methods in systems with preamble-based training signals transmitted over clustersparse channels.
Water transport by the bacterial channel alpha-hemolysin
Paula, S.; Akeson, M.; Deamer, D.
1999-01-01
This study is an investigation of the ability of the bacterial channel alpha-hemolysin to facilitate water permeation across biological membranes. alpha-Hemolysin channels were incorporated into rabbit erythrocyte ghosts at varying concentrations, and water permeation was induced by mixing the ghosts with hypertonic sucrose solutions. The resulting volume decrease of the ghosts was followed by time-resolved optical absorption at pH 5, 6, and 7. The average single-channel permeability coefficient of alpha-hemolysin for water ranged between 1.3x10-12 cm/s and 1.5x10-12 cm/s, depending on pH. The slightly increased single-channel permeability coefficient at lower pH-values was attributed to an increase in the effective pore size. The activation energy of water transport through the channel was low (Ea=5.4 kcal/mol), suggesting that the properties of water inside the alpha-hemolysin channel resemble those of bulk water. This conclusion was supported by calculations based on macroscopic hydrodynamic laws of laminar water flow. Using the known three-dimensional structure of the channel, the calculations accurately predicted the rate of water flow through the channel. The latter finding also indicated that water permeation data can provide a good estimate of the pore size for large channels.
International Nuclear Information System (INIS)
Na, Jonggeol; Jung, Ikhwan; Kshetrimayum, Krishnadash S.; Park, Seongho; Park, Chansaem; Han, Chonghun
2014-01-01
Driven by both environmental and economic reasons, the development of small to medium scale GTL(gas-to-liquid) process for offshore applications and for utilizing other stranded or associated gas has recently been studied increasingly. Microchannel GTL reactors have been preferred over the conventional GTL reactors for such applications, due to its compactness, and additional advantages of small heat and mass transfer distance desired for high heat transfer performance and reactor conversion. In this work, multi-microchannel reactor was simulated by using commercial CFD code, ANSYS FLUENT, to study the geometric effect of the microchannels on the heat transfer phenomena. A heat generation curve was first calculated by modeling a Fischer-Tropsch reaction in a single-microchannel reactor model using Matlab-ASPEN integration platform. The calculated heat generation curve was implemented to the CFD model. Four design variables based on the microchannel geometry namely coolant channel width, coolant channel height, coolant channel to process channel distance, and coolant channel to coolant channel distance, were selected for calculating three dependent variables namely, heat flux, maximum temperature of coolant channel, and maximum temperature of process channel. The simulation results were visualized to understand the effects of the design variables on the dependent variables. Heat flux and maximum temperature of cooling channel and process channel were found to be increasing when coolant channel width and height were decreased. Coolant channel to process channel distance was found to have no effect on the heat transfer phenomena. Finally, total heat flux was found to be increasing and maximum coolant channel temperature to be decreasing when coolant channel to coolant channel distance was decreased. Using the qualitative trend revealed from the present study, an appropriate process channel and coolant channel geometry along with the distance between the adjacent
International Nuclear Information System (INIS)
Derry, T.E.
1978-06-01
Diamond is one of the most extreme cases from a channelling point of view, having the smallest thermal vibration amplitude and the lowest atomic number of commonly-encountered crystals. These are the two parameters most important for determining channelling behaviour. It is of consiberable interest therefore to see how well the theories explaining and predicting the channeling properties of other substance, succeed with diamond. Natural diamond, although the best available form for these experiments, is rather variable in its physical properties. Part of the project was devoted to considering and solving the problem of obtaining reproducible results representative of the ideal crystal. Channelling studies were performed on several good crystals, using the Rutherford backscattering method. Critical angles for proton channelling were measured for incident energies from 0.6 to 4.5 MeV, in the three most open axes and three most open planes of the diamond structure, and for α-particle channelling at 0.7 and 1.0 MeV (He + ) in the same axes and planes. For 1.0 MeV protons, the crystal temperature was varied from 20 degrees Celsius to 700 degrees Celsius. The results are presented as curves of backscattered yield versus angle in the region of each axis or plane, and summarised in the form of tables and graphs. Generally the critical angles, axial minimum yields, and temperature dependence are well predicted by the accepted theories. The most valuable overall conclusion is that the mean thermal vibration amplitude of the atoms in a crytical determines the critical approach distance to the channel walls at which an ion can remain channelled, even when this distance is much smaller than the Thomas-Fermi screening distance of the atomic potential, as is the case in diamond. A brief study was made of the radiation damage caused by α-particle bombardment, via its effect on the channelling phenomenon. It was possible to hold damage down to negligible levels during the
Sensitivity calculation of the coolant temperature regarding the thermohydraulic parameters
International Nuclear Information System (INIS)
Andrade Lima, F.R. de; Silva, F.C. da; Thome Filho, Z.D.; Alvim, A.C.M.; Oliveira Barroso, A.C. de.
1985-01-01
It's studied the application of the Generalized Perturbation Theory (GPT) in the sensitivity calculation of thermalhydraulic problems, aiming at verifying the viability of the extension of the method. For this, the axial distribution, transient, of the coolant temperature in a PWR channel are considered. Perturbation expressions are developed using the GPT formalism, and a computer code (Tempera) is written, to calculate the channel temperature distribution and the associated importance function, as well as the effect of the thermalhydraulic parameters variations in the coolant temperature (sensitivity calculation). The results are compared with those from the direct calculation. (E.G.) [pt
Design Methodology - Design Synthesis
DEFF Research Database (Denmark)
Andreasen, Mogens Myrup
2003-01-01
Design Methodology is part of our practice and our knowledge about designing, and it has been strongly supported by the establishing and work of a design research community. The aim of this article is to broaden the reader¿s view of designing and Design Methodology. This is done by sketching...... the development of Design Methodology through time and sketching some important approaches and methods. The development is mainly forced by changing industrial condition, by the growth of IT support for designing, but also by the growth of insight into designing created by design researchers.......ABSTRACT Design Methodology shall be seen as our understanding of how to design; it is an early (emerging late 60ies) and original articulation of teachable and learnable methodics. The insight is based upon two sources: the nature of the designed artefacts and the nature of human designing. Today...
GPS system simulation methodology
Ewing, Thomas F.
1993-01-01
The following topics are presented: background; Global Positioning System (GPS) methodology overview; the graphical user interface (GUI); current models; application to space nuclear power/propulsion; and interfacing requirements. The discussion is presented in vugraph form.
Hazard classification methodology
International Nuclear Information System (INIS)
Brereton, S.J.
1996-01-01
This document outlines the hazard classification methodology used to determine the hazard classification of the NIF LTAB, OAB, and the support facilities on the basis of radionuclides and chemicals. The hazard classification determines the safety analysis requirements for a facility
Nonlinear Image Denoising Methodologies
National Research Council Canada - National Science Library
Yufang, Bao
2002-01-01
In this thesis, we propose a theoretical as well as practical framework to combine geometric prior information to a statistical/probabilistic methodology in the investigation of a denoising problem...
National Research Council Canada - National Science Library
Peace, Karl E; Chen, Ding-Geng
2011-01-01
"Now viewed as its own scientific discipline, clinical trial methodology encompasses the methods required for the protection of participants in a clinical trial and the methods necessary to provide...
Drifting plasmons in open two-dimensional channels: modal analysis
International Nuclear Information System (INIS)
Sydoruk, O
2013-01-01
Understanding the properties of plasmons in two-dimensional channels is important for developing methods of terahertz generation. This paper presents a modal analysis of plasmonic reflection in open channels supporting dc currents. As it shows, the plasmons can be amplified upon reflection if a dc current flows away from a conducting boundary; de-amplification occurs for the opposite current direction. The problem is solved analytically, based on a perturbation calculation, and numerically, and agreement between the methods is demonstrated. The power radiated by a channel is found to be negligible, and plasmon reflection in open channels is shown to be similar to that in closed channels. Based on this similarity, the oscillator designs developed earlier for closed channels could be applicable also for open ones. The results develop the modal-decomposition technique further as an instrument for the design of terahertz plasmonic sources. (paper)
Transmission channels through Na and Al atom wire
DEFF Research Database (Denmark)
Kobayashi, N.; Brandbyge, Mads; Tsukada, M.
1999-01-01
First-principles calculations of the transmission channels of single-atom-width Na and Al atom wires bridged between metallic jellium electrodes are presented. For the Na wire, a single channel contributes to the conduction with an almost full quantization value, 2e(2)/h. The conductance...... is insensitive to the geometrical change since the Fermi energy is located above the onset energy of the channel showing the quantization of conductance. On the other hand, for the Al wire. three channels contribute to the conduction. The Fermi energy is placed just at the onset of the second and the third...... channels, and the channel transmissions are very sensitive to the geometrical changes of the wires. (C) 1999 Elsevier Science B.V. All rights reserved....
An equipment for the dimensional characterization of irradiated fuel channels
International Nuclear Information System (INIS)
Cederquist, H.
1985-01-01
The reuse of irradiated fuel channels in BWRs is highly beneficial. However, one prerequisite for reuse of a fuel channel is the detailed knowledge of its dimensions, which are affected by irradiation and pressure drop during operation. Therefore an equipment for fast and accurate dimensional measurement of irradiated fuel channels has been developed. The measurements are carried out when the fuel assembly is supported in the same manner as in the reactor core. The equipment utilizes stationary ultrasonic transducers that measure the fuel channel at a number of predetermined axial levels. Measurement data are fed into a computer which calculates the requested dimensional characteristics such as transversal flatness, bow, twist, side perpendicularity etc. Data are automatically printed for subsequent evaluation. Measurements can be performed both when the fuel channel is placed on a fuel bundle and on an empty fuel channel
Methodology of sustainability accounting
Directory of Open Access Journals (Sweden)
O.H. Sokil
2017-03-01
Full Text Available Modern challenges of the theory and methodology of accounting are realized through the formation and implementation of new concepts, the purpose of which is to meet the needs of users in standard and unique information. The development of a methodology for sustainability accounting is a key aspect of the management of an economic entity. The purpose of the article is to form the methodological bases of accounting for sustainable development and determine its goals, objectives, object, subject, methods, functions and key aspects. The author analyzes the theoretical bases of the definition and considers the components of the traditional accounting methodology. Generalized structural diagram of the methodology for accounting for sustainable development is offered in the article. The complex of methods and principles of sustainable development accounting for systematized and non-standard provisions has been systematized. The new system of theoretical and methodological provisions of accounting for sustainable development is justified in the context of determining its purpose, objective, subject, object, methods, functions and key aspects.
Coupled channels in the different models
International Nuclear Information System (INIS)
Badalyan, A.M.; Polikarpov, M.I.; Simonov, Yu.A.
1980-01-01
Description of the multichannel phenomena due to channel coupling is considered. The different methods: the relativistic Logunov-Tavkhelidze-Blankenbecler-Sugar equations, the Schroedinger equation with the separable potentials and the many-channel N-D method are discussed. The particular emphasis is made on the dependence of pole trajectories and cross sections on the parameters of the coupled channel (CC) pole interaction. In detail the properties of the N anti N interaction with annihilation are taken into account. Elastic, charge exchange and annihilation cross sections are calculated in the 0-100 MeV energy range. The peaks in all cross sections at the threshold are due to the CC poles in the L=0 waves. The position of the 16 poles in different states for the case of no CC interaction and the standard CC interaction is presented
Boiling crisis during liquid motion at high mass rate and underheating in channels
International Nuclear Information System (INIS)
Solov'ev, D.S.; Solov'ev, S.L.
2007-01-01
One describes a physical model of liquid boiling crisis in smooth wall channels for high values of underheating and of mass rate of flow. One worded a condition ensuring crisis initiation. Paper presents the calculated ratio for the critical density of thermal flow in channels enabling to analyze the effect of channel diameter, of underheating and of mass rate on it [ru
Channel Choice: A Literature Review
DEFF Research Database (Denmark)
Østergaard Madsen, Christian; Kræmmergaard, Pernille
2015-01-01
The channel choice branch of e-government studies citizens’ and businesses’ choice of channels for interacting with government, and how government organizations can integrate channels and migrate users towards the most cost-efficient channels. In spite of the valuable contributions offered...
National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity,...
A possible CO2 conducting and concentrating mechanism in plant stomata SLAC1 channel.
Directory of Open Access Journals (Sweden)
Qi-Shi Du
Full Text Available BACKGROUND: The plant SLAC1 is a slow anion channel in the membrane of stomatal guard cells, which controls the turgor pressure in the aperture-defining guard cells, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought, high levels of carbon dioxide, and bacterial invasion. Recent study demonstrated that bicarbonate is a small-molecule activator of SLAC1. Higher CO(2 and HCO(3(- concentration activates S-type anion channel currents in wild-type Arabidopsis guard cells. Based on the SLAC1 structure a theoretical model is derived to illustrate the activation of bicarbonate to SLAC1 channel. Meanwhile a possible CO(2 conducting and concentrating mechanism of the SLAC1 is proposed. METHODOLOGY: The homology structure of Arabidopsis thaliana SLAC1 (AtSLAC1 provides the structural basis for study of the conducting and concentrating mechanism of carbon dioxide in SLAC1 channels. The pK(a values of ionizable amino acid side chains in AtSLAC1 are calculated using software PROPKA3.0, and the concentration of CO(2 and anion HCO(3(- are computed based on the chemical equilibrium theory. CONCLUSIONS: The AtSLAC1 is modeled as a five-region channel with different pH values. The top and bottom layers of channel are the alkaline residue-dominated regions, and in the middle of channel there is the acidic region surrounding acidic residues His332. The CO(2 concentration is enhanced around 10(4 times by the pH difference between these regions, and CO(2 is stored in the hydrophobic region, which is a CO(2 pool. The pH driven CO(2 conduction from outside to inside balances the back electromotive force and maintain the influx of anions (e.g. Cl(- and NO(3(- from inside to outside. SLAC1 may be a pathway providing CO(2 for photosynthesis in the guard cells.
Cryogenic microwave channelized receiver
International Nuclear Information System (INIS)
Rauscher, C.; Pond, J.M.; Tait, G.B.
1996-01-01
The channelized receiver being presented demonstrates the use of high temperature superconductor technology in a microwave system setting where superconductor, microwave-monolithic-integrated-circuit, and hybrid-integrated-circuit components are united in one package and cooled to liquid-nitrogen temperatures. The receiver consists of a superconducting X-band four-channel demultiplexer with 100-MHz-wide channels, four commercial monolithically integrated mixers, and four custom-designed hybrid-circuit detectors containing heterostructure ramp diodes. The composite receiver unit has been integrated into the payload of the second-phase NRL high temperature superconductor space experiment (HTSSE-II). Prior to payload assembly, the response characteristics of the receiver were measured as functions of frequency, temperature, and drive levels. The article describes the circuitry, discusses the key issues related to design and implementation, and summarizes the experimental results
Energy Technology Data Exchange (ETDEWEB)
Hosur, Pavan; Qi, Xiao-Liang [Department of Physics, Stanford University,476 Lomita Mall, Stanford, California 94305 (United States); Roberts, Daniel A. [Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, Massachusetts 02139 (United States); Yoshida, Beni [Perimeter Institute for Theoretical Physics,31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E California Blvd, Pasadena CA 91125 (United States)
2016-02-01
We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling.
Distribution Channels Conflict and Management
Kiran, Dr Vasanth; Majumdar, Dr Mousumi; Kishore, Dr Krishna
2012-01-01
Relationships in distribution channels tend to be long-term oriented and members of the channel rely on each other to jointly realize their goals by serving buyers. Despite the channels focus on serving buyers, conflicts often arise between channel members because of each members self-interest. When conflicts arise, the perceptions of a channel member based on normative, rational/instrumental, or emotional reasoning will influence relational norms like trust and commitment that characterize t...
High-temperature thermal-chemical analysis of nuclear fuel channels
Energy Technology Data Exchange (ETDEWEB)
Nekhamkin, Y; Rosenband, V; Hasan, D; Elias, E; Wacholder, E; Gany, A [Technion-Israel Inst. of Tech., Haifa (Israel)
1996-12-01
In a severe accident situation, e.g., a postulated loss of coolant accident with a coincident loss of emergency core cooling (LOCA/LOECC), the core may become partially uncovered and steam may become the only coolant available. The thermodynamic conditions in the core, in this case, depend on ability of the steam to effectively remove the fuel decay heat and the heat generated by the exothermic steam/Zircaloy reaction., Therefore, it is important to understand the high-temperature behavior of an oxidizing fuel channel. The main objective of this work is to develop a methodology for calculating the clad temperature and rate of oxidation of a partially covered fuel pin. A criterion is derived to define the importance of the chemical reaction in the overall heat balance. The main parameters affecting the fuel thermal behavior are outlined (authors).
Regional Shelter Analysis Methodology
Energy Technology Data Exchange (ETDEWEB)
Dillon, Michael B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dennison, Deborah [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kane, Jave [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Walker, Hoyt [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Miller, Paul [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2015-08-01
The fallout from a nuclear explosion has the potential to injure or kill 100,000 or more people through exposure to external gamma (fallout) radiation. Existing buildings can reduce radiation exposure by placing material between fallout particles and exposed people. Lawrence Livermore National Laboratory was tasked with developing an operationally feasible methodology that could improve fallout casualty estimates. The methodology, called a Regional Shelter Analysis, combines the fallout protection that existing buildings provide civilian populations with the distribution of people in various locations. The Regional Shelter Analysis method allows the consideration of (a) multiple building types and locations within buildings, (b) country specific estimates, (c) population posture (e.g., unwarned vs. minimally warned), and (d) the time of day (e.g., night vs. day). The protection estimates can be combined with fallout predictions (or measurements) to (a) provide a more accurate assessment of exposure and injury and (b) evaluate the effectiveness of various casualty mitigation strategies. This report describes the Regional Shelter Analysis methodology, highlights key operational aspects (including demonstrating that the methodology is compatible with current tools), illustrates how to implement the methodology, and provides suggestions for future work.
International Nuclear Information System (INIS)
Andrade Lima, F.R. de
1986-01-01
The sensitivity of non linear responses associated with physical quantities governed by non linear differential systems can be studied using perturbation theory. The equivalence and formal differences between the differential and GPT formalisms are shown and both are used for sensitivity calculations of transient problems in a typical PWR coolant channel. The results obtained are encouraging with respect to the potential of the method for thermalhydraulics calculations normally performed for reactor design and safety analysis. (Author) [pt
International Nuclear Information System (INIS)
Shoukri, M.; Abdul-Razzak, A.
1992-11-01
This report extends the work reported in document INFO-0370 on fuel channel refilling by providing analysis of the refilling tests conducted using the RD-14 and RD-14M test facilities. The analysis focuses on the general thermal-hydraulic characteristics of the facilities following various small and large inlet and outlet header breaks with emergency coolant injection. The two-fluid model thermal-hydraulic computer code CATHENA was tested against results obtained from selected experiments carried out in the two facilities. Conclusions related to the effect of break size, mode of emergency core injection, primary pump operation and parallel channels are presented. (Author) (116 figs., 17 tabs., 53 refs.)
Molenaar, Remco J
2011-01-01
Glioblastoma is the most common primary brain tumor with the most dismal prognosis. It is characterized by extensive invasion, migration, and angiogenesis. Median survival is only 15 months due to this behavior, rendering focal surgical resection ineffective and adequate radiotherapy impossible. At this moment, several ion channels have been implicated in glioblastoma proliferation, migration, and invasion. This paper summarizes studies on potassium, sodium, chloride, and calcium channels of glioblastoma. It provides an up-to-date overview of the literature that could ultimately lead to new therapeutic targets.
International Nuclear Information System (INIS)
Shoukri, M.; Abdul-Razzak, A.
1990-04-01
Analysis of existing data on fuel channel refilling is presented. The analysis focuses on the data obtained using the Stern Laboratories Cold Water Injection Test (CWIT) Facility. The two-fluid model thermal-hydraulics computer code CATHENA is also used to simulate experimental results on fuel channel refilling from both the CWIT and RD-14 facilities. Conclusions related to single and double break tests, including the effect of non-condensible gases, are presented. A set of recommendations is given for further analysis and separate effect experiments. (67 figs., 5 tabs., 24 refs.)
Methodology for Mode Selection in Corridor Analysis of Freight Transportation
Kanafani, Adib
1984-01-01
The purpose of tins report is to outline a methodology for the analysis of mode selection in freight transportation. This methodology is intended to partake of transportation corridor analysts, a component of demand analysis that is part of a national transportation process. The methodological framework presented here provides a basis on which specific models and calculation procedures might be developed. It also provides a basis for the development of a data management system suitable for co...
Distinctive fingerprints of erosional regimes in terrestrial channel networks
Grau Galofre, A.; Jellinek, M.
2017-12-01
Satellite imagery and digital elevation maps capture the large scale morphology of channel networks attributed to long term erosional processes, such as fluvial, glacial, groundwater sapping and subglacial erosion. Characteristic morphologies associated with each of these styles of erosion have been studied in detail, but there exists a knowledge gap related to their parameterization and quantification. This knowledge gap prevents a rigorous analysis of the dominant processes that shaped a particular landscape, and a comparison across styles of erosion. To address this gap, we use previous morphological descriptions of glaciers, rivers, sapping valleys and tunnel valleys to identify and measure quantitative metrics diagnostic of these distinctive styles of erosion. From digital elevation models, we identify four geometric metrics: The minimum channel width, channel aspect ratio (longest length to channel width at the outlet), presence of undulating longitudinal profiles, and tributary junction angle. We also parameterize channel network complexity in terms of its stream order and fractal dimension. We then perform a statistical classification of the channel networks using a Principal Component Analysis on measurements of these six metrics on a dataset of 70 channelized systems. We show that rivers, glaciers, groundwater seepage and subglacial meltwater erode the landscape in rigorously distinguishable ways. Our methodology can more generally be applied to identify the contributions of different processes involved in carving a channel network. In particular, we are able to identify transitions from fluvial to glaciated landscapes or vice-versa.
Investigating ion channel conformational changes using voltage clamp fluorometry.
Talwar, Sahil; Lynch, Joseph W
2015-11-01
Ion channels are membrane proteins whose functions are governed by conformational changes. The widespread distribution of ion channels, coupled with their involvement in most physiological and pathological processes and their importance as therapeutic targets, renders the elucidation of these conformational mechanisms highly compelling from a drug discovery perspective. Thanks to recent advances in structural biology techniques, we now have high-resolution static molecular structures for members of the major ion channel families. However, major questions remain to be resolved about the conformational states that ion channels adopt during activation, drug modulation and desensitization. Patch-clamp electrophysiology has long been used to define ion channel conformational states based on functional criteria. It achieves this by monitoring conformational changes at the channel gate and cannot detect conformational changes occurring in regions distant from the gate. Voltage clamp fluorometry involves labelling cysteines introduced into domains of interest with environmentally sensitive fluorophores and inferring structural rearrangements from voltage or ligand-induced fluorescence changes. Ion channel currents are monitored simultaneously to verify the conformational status. By defining real time conformational changes in domains distant from the gate, this technique provides unexpected new insights into ion channel structure and function. This review aims to summarise the methodology and highlight recent innovative applications of this powerful technique. This article is part of the Special Issue entitled 'Fluorescent Tools in Neuropharmacology'. Copyright © 2015 Elsevier Ltd. All rights reserved.
DEFF Research Database (Denmark)
Holford, John; Larson, Anne; Melo, Susana
of ‘policy trail’, arguing that it can overcome ‘methodological nationalism’ and link structure and agency in research on the ‘European educational space’. The ‘trail’ metaphor, she suggests, captures the intentionality and the erratic character of policy. The trail connects sites and brings about change......, but – although policy may be intended to be linear, with specific outcomes – policy often has to bend, and sometimes meets insurmountable obstacles. This symposium outlines and develops the methodology, but also reports on research undertaken within a major FP7 project (LLLIght’in’Europe, 2012-15) which made use......In recent years, the “policy trail” has been proposed as a methodology appropriate to the shifting and fluid governance of lifelong learning in the late modern world (Holford et al. 2013, Holford et al. 2013, Cort 2014). The contemporary environment is marked by multi-level governance (global...
The effect of closed channels on the electron impact excitation of Mg +, Cd + ions
Li, Yueming
2018-04-01
Based on the developed method for solving the multi-channel equation, which had been applied to the calculations of several kinds of ions including only open-open interactions, closed channels and their interactions with open channels have been studied. The wave functions of the closed channels are also expressed in terms of their homogeneous solutions which is just the same as for open channels. The homogeneous solutions are described and solved in WKB form, therefore the regular and irregular solutions as well as the quantum defect numbers can be obtained simultaneously. Excitations of Mg +, Cd + ions impact by electrons are calculated for energies close to the thresholds. The results are compared with those of the experimental observations and previous theoretical calculations. The effect of including the closed channels, especially when the energy passes through the resonance energies, has been discussed according to the deduced formulae and the calculated results.
Simple Ion Channels: From Structure to Electrophysiology and Back
Pohorille, Andrzej
2018-01-01
A reliable way to establish whether our understanding of a channel is satisfactory is to reproduce its measured ionic conductance over a broad range of applied voltages in computer simulations. In molecular dynamics (MD), this can be done by way of applying an external electric field to the system and counting the number of ions that traverse the channel per unit time. Since this approach is computationally very expensive, we have developed a markedly more efficient alternative in which MD is combined with the electrodiffusion (ED) equation. In this approach, the assumptions of the ED equation can be rigorously tested, and the precision and consistency of the calculated conductance can be determined. We have demonstrated that the full current/voltage dependence and the underlying free energy profile for a simple channel can be reliably calculated from equilibrium or non-equilibrium MD simulations at a single voltage. To carry out MD simulations, a structural model of a channel has to be assumed, which is an important constraint, considering that high-resolution structures are available for only very few simple channels. If the comparison of calculated ionic conductance with electrophysiological data is satisfactory, it greatly increases our confidence that the structure and the function are described sufficiently accurately. We examined the validity of the ED for several channels embedded in phospholipid membranes - four naturally occurring channels: trichotoxin, alamethicin, p7 from hepatitis C virus (HCV) and Vpu from the HIV-1 virus, and a synthetic, hexameric channel, formed by a 21-residue peptide that contains only leucine and serine. All these channels mediate transport of potassium and chloride ions. It was found that the ED equation is satisfactory for these systems. In some of them experimental and calculated electrophysiological properties are in good agreement, whereas in others there are strong indications that the structural models are incorrect.
Potassium channels in brain mitochondria.
Bednarczyk, Piotr
2009-01-01
Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify
Methodology for estimating sodium aerosol concentrations during breeder reactor fires
International Nuclear Information System (INIS)
Fields, D.E.; Miller, C.W.
1985-01-01
We have devised and applied a methodology for estimating the concentration of aerosols released at building surfaces and monitored at other building surface points. We have used this methodology to make calculations that suggest, for one air-cooled breeder reactor design, cooling will not be compromised by severe liquid-metal fires
International Nuclear Information System (INIS)
Sharma, V.K.; Surendar, C.; Bapat, C.N.
1994-01-01
The Indian Pressurized Heavy Water Reactors (IPHWR) are horizontal pressure tube reactors using natural uranium oxide fuel in the form of short (495 mm) clusters. The fuel clusters in the Zr-Nb pressure tubes are cooled by high pressure, high temperature and subcooled circulating heavy water. Coolant flow distribution to individual channels is designed to match the power distribution so as to obtain uniform coolant outlet temperature. However, during operation, the coolant outlet temperature in individual channels deviate from their nominal value due to: tolerances in process design; effects of grid frequency on the pump speed; deviation in channel powers from the nominal values due to on-power fuelling and movement of reactivity devices, and so on. Thus an operating margin, between the highest permissible and nominal coolant outlet temperatures, is required taking into account various hot channel factors that contribute to higher coolant outlet temperatures. The paper discusses the methodology adopted to assess various hot channel factors which would provide optimum operating margins while ensuring sub-cooling. (author)
Improvements in EBR-2 core depletion calculations
International Nuclear Information System (INIS)
Finck, P.J.; Hill, R.N.; Sakamoto, S.
1991-01-01
The need for accurate core depletion calculations in Experimental Breeder Reactor No. 2 (EBR-2) is discussed. Because of the unique physics characteristics of EBR-2, it is difficult to obtain accurate and computationally efficient multigroup flux predictions. This paper describes the effect of various conventional and higher order schemes for group constant generation and for flux computations; results indicate that higher-order methods are required, particularly in the outer regions (i.e. the radial blanket). A methodology based on Nodal Equivalence Theory (N.E.T.) is developed which allows retention of the accuracy of a higher order solution with the computational efficiency of a few group nodal diffusion solution. The application of this methodology to three-dimensional EBR-2 flux predictions is demonstrated; this improved methodology allows accurate core depletion calculations at reasonable cost. 13 refs., 4 figs., 3 tabs
Health economic assessment: a methodological primer.
Simoens, Steven
2009-12-01
This review article aims to provide an introduction to the methodology of health economic assessment of a health technology. Attention is paid to defining the fundamental concepts and terms that are relevant to health economic assessments. The article describes the methodology underlying a cost study (identification, measurement and valuation of resource use, calculation of costs), an economic evaluation (type of economic evaluation, the cost-effectiveness plane, trial- and model-based economic evaluation, discounting, sensitivity analysis, incremental analysis), and a budget impact analysis. Key references are provided for those readers who wish a more advanced understanding of health economic assessments.
Health Economic Assessment: A Methodological Primer
Directory of Open Access Journals (Sweden)
Steven Simoens
2009-11-01
Full Text Available This review article aims to provide an introduction to the methodology of health economic assessment of a health technology. Attention is paid to defining the fundamental concepts and terms that are relevant to health economic assessments. The article describes the methodology underlying a cost study (identification, measurement and valuation of resource use, calculation of costs, an economic evaluation (type of economic evaluation, the cost-effectiveness plane, trial- and model-based economic evaluation, discounting, sensitivity analysis, incremental analysis, and a budget impact analysis. Key references are provided for those readers who wish a more advanced understanding of health economic assessments.
Simplified methodology for Angra 1 containment analysis
International Nuclear Information System (INIS)
Neves Conti, T. das; Souza, A.L. de; Sabundjian, G.
1991-08-01
A simplified methodology of analysis was developed to simulate a Large Break Loss of Coolant Accident in the Angra 1 Nuclear Power Station. Using the RELAP5/MOD1, RELAP4/MOD5 and CONTEMPT-LT Codes, the time variation of pressure and temperature in the containment was analysed. The obtained data was compared with the Angra 1 Final Safety Analysis Report, and too those calculated by a Detailed Model. The results obtained by this new methodology such as the small computational time of simulation, were satisfactory when getting the preliminary evaluation of the Angra 1 global parameters. (author)
Methodology for generating waste volume estimates
International Nuclear Information System (INIS)
Miller, J.Q.; Hale, T.; Miller, D.
1991-09-01
This document describes the methodology that will be used to calculate waste volume estimates for site characterization and remedial design/remedial action activities at each of the DOE Field Office, Oak Ridge (DOE-OR) facilities. This standardized methodology is designed to ensure consistency in waste estimating across the various sites and organizations that are involved in environmental restoration activities. The criteria and assumptions that are provided for generating these waste estimates will be implemented across all DOE-OR facilities and are subject to change based on comments received and actual waste volumes measured during future sampling and remediation activities. 7 figs., 8 tabs
International Nuclear Information System (INIS)
Carossi, Jean-Claude
1969-02-01
A CO 2 flowrate calculator has been designed for measuring and recording the gas flow in the loops of Pegase reactor. The analog calculator applies, at every moment, Bernoulli's formula to the values that characterize the carbon dioxide flow through a nozzle. The calculator electronics is described (it includes a sampling calculator and a two-variable function generator), with its amplifiers, triggers, interpolator, multiplier, etc. Calculator operation and setting are presented