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Sample records for preliminary stability calculations

  1. HEU benchmark calculations and LEU preliminary calculations for IRR-1

    International Nuclear Information System (INIS)

    Caner, M.; Shapira, M.; Bettan, M.; Nagler, A.; Gilat, J.

    2004-01-01

    We performed neutronics calculations for the Soreq Research Reactor, IRR-1. The calculations were done for the purpose of upgrading and benchmarking our codes and methods. The codes used were mainly WIMS-D/4 for cell calculations and the three dimensional diffusion code CITATION for full core calculations. The experimental flux was obtained by gold wire activation methods and compared with our calculated flux profile. The IRR-1 is loaded with highly enriched uranium fuel assemblies, of the plate type. In the framework of preparation for conversion to low enrichment fuel, additional calculations were done assuming the presence of LEU fresh fuel. In these preliminary calculations we investigated the effect on the criticality and flux distributions of the increase of U-238 loading, and the corresponding uranium density.(author)

  2. Preliminary isodose calculation for gynecological curietherapy

    International Nuclear Information System (INIS)

    Bridier, A.; Dutreix, A.; Gerbaulet, A.; Chassagne, D.

    1981-01-01

    We present a preliminary method of calculating the dimensions of the reference isodose, based upon the geometrical distribution and length of the sources used, their linear activity and the length of treatment, that does not require use of a computer. Inversely, this method can be used to determine the factors necessary to produce a given shape of isodose, and also to predict the change in shape of the isodose that will be produced by altering the various factors. This method was derived from a systematic computer study of dose distribution in which each factor was varied independently of all others. The dimensions of the isodoses, calculated by this method, were found to be in agreement with those derived from computer calculation to within an error of about 2 mm. The method is only applicable for a limited range of positions of the vaginal sources. The influence of the positions of these sources along the line of the axis of uterine catheter and of their inclination to this line, are currently being studied. The results are presented as mathematical formulae relating each dimension of the isodose curves to the features of the application, but could equally well be expressed in tabular form that would be more convenient for everyday use. An example of the calculation used is given to facilitate understanding of the method [fr

  3. Stability calculations for MHD magnets

    International Nuclear Information System (INIS)

    Turner, L.R.; Wang, S.T.; Harrang, J.

    1978-01-01

    When a cryostable composite conductor carrying current experiences a heat input from a mechanical perturbation, a normal region develops which initially propagates and then either collapses or continues to propagate. A computer model has been devised to study this phenomenon. The model incorporates initial or continuing heat input from mechanical perturbations, heat conducted to the neighboring elements of the conductor and, if appropriate, heat conducted through insulation to neighboring turns. Heat is transferred to the helium coolant according to a specified heat transfer coefficient. If the element of conductor is in a normal or current-sharing state, resistive heating also occurs. The (unstable) equilibrium state of heat generation and conduction has been studied; results agree with those of a static calculation. The model has been validated against experimental measurements of response to heat pulses. The model suffers from uncertainties in transient heat transfer to the helium, but even more from uncertainties in the perturbing heat pulse which the magnet might be expected to suffer

  4. Preliminary Slope Stability Study Using Slope/ W

    International Nuclear Information System (INIS)

    Nazran Harun; Mohd Abd Wahab Yusof; Kamarudin Samuding; Mohd Muzamil Mohd Hashim; Nurul Fairuz Diyana Bahrudin

    2014-01-01

    Analyzing the stability of earth structures is the oldest type of numerical analysis in geotechnical engineering. Limit equilibrium types of analyses for assessing the stability of earth slopes have been in use in geotechnical engineering for many decades. Modern limit equilibrium software is making it possible to handle ever-increasing complexity within an analysis. It is being considered as the potential method in dealing with complex stratigraphy, highly irregular pore-water pressure conditions, various linear and nonlinear shear strength models and almost any kind of slip surface shape. It allows rapid decision making by providing an early indication of the potential suitability of sites based on slope stability analysis. Hence, a preliminary slope stability study has been developed to improve the capacity of Malaysian Nuclear Agency (Nuclear Malaysia) in assessing potential sites for Borehole Disposal for Disused Sealed Radioactive Sources. The results showed that geometry of cross section A-A ' , B-B ' , C-C ' and D-D ' achieved the factor of safety not less than 1.4 and these are deemed acceptable. (author)

  5. 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.

  6. Calculation of NPP pipeline seismic stability

    International Nuclear Information System (INIS)

    Kirillov, A.P.; Ambriashvili, Yu.K.; Kaliberda, I.V.

    1982-01-01

    A simplified design procedure of seismic pipeline stability of NPP at WWER reactor is described. The simplified design procedure envisages during the selection and arrangement of pipeline saddle and hydraulic shock absorbers use of method of introduction of resilient mountings of very high rigidity into the calculated scheme of the pipeline and performance of calculations with step-by-step method. It is concluded that the application of the design procedure considered permits to determine strains due to seismic loads, to analyze stressed state in pipeline elements and supporting power of pipe-line saddle with provision for seismic loads to plan measures on seismic protection

  7. Calculability and stability in the flipped string

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, J.L.; Nanopoulos, D.V. (Texas A and M Univ., College Station, TX (USA). Center for Theoretical Physics Houston Advanced Research Center (HARC), The Woodlands, TX (USA). Astroparticle Physics Group)

    1991-03-07

    We show that the highly successful structure of the recently proposed superstring flipped SU(5) model remains intact after the inclusion in the superpotential of the low-energy effective theory of all relevant string-induced nonrenormalizable terms. This structure provides for only two light Higgs doublets, hierarchical fermion mass matrices, and an adequate proton lifetime. We reach this conclusion explicit calculations using a recently derived set of rules to evaluate nonrenormalizable terms in the four-dimensional free fermionic formulation of superstrings. This remarkable stability of the infrared limit of the flipped string makes its experimental predictions trustworthy and hence its physical existence falsifiable. (orig.).

  8. Fast axisymmetric stability calculations using variational techniques

    International Nuclear Information System (INIS)

    Haney, S.W., Pearlstein, L.D.; Bulmer, R.H.

    1991-01-01

    A procedure for treating the axisymmetric (n = 0) stability of diverted plasmas in the presence of arbitrary, but toroidally symmetric, structures and active feedback circuits has been developed and implemented as a module in the TEQ free-boundary equilibrium code. This procedure is based on a variational solution of the ideal MHD normal mode equations. Inertia is ordered small but provides a constraint to allow the calculation of the poloidal and toroidal components of the plasma displacement. Feedback based on flux loop measurements is handled by introducing an adjoint system into the variational principle. Approximately 200 trial functions for the radial component of the plasma displacement and 200 magnetic surfaces are employed to obtain highly accurate estimates of the passive growth rate and the non-rigid eigenfunction. Nevertheless, the method is extremely fast: typically 10-20 sec of Cray 2 CPU time are required to analyze a realistic tokamak configuration. This speed, along with the direct coupling to the MHD equilibrium solver, allows interactive investigations of tokamak axisymmetric stability. Benchmarks with TSC and GATO are presented along with parameter scans for ITER and BPX. The results emphasize the importance of considering non-rigid mode effects which for ITER, yield higher nominal growth rates (non-rigid: 45 Hz, rigid: 25 Hz) and atypical internal inductance dependence (smaller l i more unstable)

  9. Linear ideal MHD stability calculations for ITER

    International Nuclear Information System (INIS)

    Hogan, J.T.

    1988-01-01

    A survey of MHD stability limits has been made to address issues arising from the MHD--poloidal field design task of the US ITER project. This is a summary report on the results obtained to date. The study evaluates the dependence of ballooning, Mercier and low-n ideal linear MHD stability on key system parameters to estimate overall MHD constraints for ITER. 17 refs., 27 figs

  10. Probabilistic Damage Stability Calculations for Ships

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    1996-01-01

    The aim of these notes is to provide background material for the present probabilistic damage stability rules fro dry cargo ships.The formulas for the damage statistics are derived and shortcomings as well as possible improvements are discussed. The advantage of the definiton of fictitious...... compartments in the formulation of a computer-based general procedure for probabilistic damaged stability assessment is shown. Some comments are given on the current state of knowledge on the ship survivability in damaged conditions. Finally, problems regarding proper account of water ingress through openings...

  11. Preliminary topical report on comparison reactor disassembly calculations

    International Nuclear Information System (INIS)

    McLaughlin, T.P.

    1975-11-01

    Preliminary results of comparison disassembly calculations for a representative LMFBR model (2100-l voided core) and arbitrary accident conditions are described. The analytical methods employed were the computer programs: FX2-POOL, PAD, and VENUS-II. The calculated fission energy depositions are in good agreement, as are measures of the destructive potential of the excursions, kinetic energy, and work. However, in some cases the resulting fuel temperatures are substantially divergent. Differences in the fission energy deposition appear to be attributable to residual inconsistencies in specifying the comparison cases. In contrast, temperature discrepancies probably stem from basic differences in the energy partition models inherent in the codes. Although explanations of the discrepancies are being pursued, the preliminary results indicate that all three computational methods provide a consistent, global characterization of the contrived disassembly accident

  12. Preliminary physics calculations for the Clinch River Breeder Reactor

    International Nuclear Information System (INIS)

    Kalimullah.

    1975-01-01

    Calculations of sodium void, fuel, and clad worths, power distribution, and control rod worths have been carried out for an R-Z model of the CRBR, using diffusion theory and first-order perturbation theory for material worths. The power distribution and control rod worths have also been calculated in two-dimensional triangular mesh geometry. The present results are preliminary because of inaccuracy of the reactor model and the cross sections used, but the final results are not expected to be greatly different. (U.S.)

  13. Preliminary Calculation on a Spent Fuel Pool Accident using GOTHIC

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jaehwan; Choi, Yu Jung; Hong, Tae Hyub; Kim, Hyeong-Taek [KHNP-CRI, Daejeon (Korea, Republic of)

    2015-10-15

    The probability of an accident happening at the spent fuel pool was believed to be quite low until the 2011 Fukushima accident occurred. Notably, large amount of spent fuel are normally stored in the spent fuel pool for a long time compared to the amount of fuel in the reactor core and the total heat released from the spent fuel is high enough to boil the water of the spent fuel pool when the cooling system does not operate. In addition, the enrichment and the burnup of the fuel have both increased in the past decade and heat generation from the spent fuel thereby has also increased. The failure of the cooling system at the spent fuel pool (hereafter, a loss-of-cooling accident) is one of the principal hypothetical causes of an accident that could occur at the spent fuel pool. In this paper, the preliminary calculation of a loss-of-cooling accident was performed. In this paper, the preliminary calculation of a loss-of cooling accident was performed with GOTHIC. The calculation results show boiling away of water in the spent fuel pool due to the loss-of-cooling accident and similar thermal performance of the spent fuel pool with previous research results.

  14. Preliminary Analysis For Wolsong Par Effects Using ISACC Calculations

    International Nuclear Information System (INIS)

    Song, Yong Mann; Kim, Dong Ha

    2012-01-01

    In the paper, hydrogen control effects using PARs only are analyzed for severe SBO station blackout (SBO) sequences beyond the design basis accidents in WS-1 which are of CANDU6 type reactor. As a computational tool, the latest version of ISAAC4.3 (Integrated Severe Accident Analysis Code for CANDU), which is a fully integrated and lumped severe accident computer code, is used to simulate hydrogen generation and transport inside the reactor building (R/B) before its failure. For the performance of hydrogen removal, the depletion rate equation of K-PAR developed in Korea is applied. In a CANDU reactor, three areas are identified as sources of hydrogen under severe accidents: fuel-coolant interactions in intact channels, suspended fuel or debris interactions in-calandria tank and debris interactions in-calandria vault. The first two origins provide source for the late ('late' terminology is used because it takes more than one day before calandria tank failure) potential hydrogen combustion before calandria tank failure and all the three origins would provide source for the very late potential hydrogen combustion occurring at or after calaria tank failure. If the hydrogen mitigation system fails, the AICC (adiabatic isochoric complete combustion) burning of highly flammable hydrogen may cause Wolsong R/B failure. So hydrogen induced failure possibility is evaluated, using preliminary ISAAC calculations, under several SBO conditions with and without PAR for both late and very late accident periods

  15. Available transfer capability calculation considering voltage stability margin

    International Nuclear Information System (INIS)

    Pan, Xiong; Xu, Guoyu

    2005-01-01

    To make the electricity trades carry out successfully, the calculation of available transfer capability (ATC) must coordinate the relationship between the security and economic benefits. In this paper, a model for ATC calculations accorded with trade-off mechanism in electricity market was set up. The impact of branch outage contingency on the static voltage stability margin was analyzed, and contingency ranking was performed through sensitivity indices of branch flows with respect to the loading margin. Optimal power flow based on primal-dual interior point method was applied to obtain ATC when the N-1 security constraints were included. The calculation results of IEEE 30-bus and IEEE 118-bus systems show that the proposed model and method are valid. (author) (N-1 security constraints; Electricity market; Available transfer capability; Optimal power flow; Voltage stability)

  16. Three-dimensional equilibria and Mercier stability calculations

    International Nuclear Information System (INIS)

    Lynch, V.E.; Dominguez, N.; Carreras, B.A.; Varias, A.; Alejaldre, C.; Fraguas, A.L.

    1989-01-01

    It is well known that an equilibrium to be used for stability calculations must be extremely accurate. These high accuracy requirements, in a fixed boundary calculation, are translated into high accuracy in the representation of the boundary. These requirements are even stricter for stellarator configurations, for which all the information about the magnetic configuration is given externally through the boundary. Many Fourier components are required to accurately represent the boundary input from a realistic coil system. For torsatron-type configurations, as many as 50 components can be needed to describe the last closed magnetic surface for the vacuum field. For a heliac configuration, the number of components can go up to 200. For 3-D calculations, there is another question of accuracy that does not apply to stability calculations for axisymmetric systems. This is the role of resonant components in the calculation of the geodesic curvature or the Pfirsch-Schlueter current. As Boozer argues, local flattening of the pressure profile eliminates the singularities generated by the resonant components. However, to implement it in a numerical calculation and to eliminate the resonant components, it is necessary to work in a coordinate system with straight magnetic field lines. This creates another problem, since the equilibrium representation in a straight magnetic field lines coordinate system requires many more components than the optimal equilibrium representation developed by Hirshman and co-workers over the last decade and implemented in the VMEC equilibrium code. In this paper, we use the VMEC equilibrium code and tranform the results to the straight magnetic field line coordinate system to calculate the input for the stability analysis. The accuracy of the transformation and the convergence of the equilibrium in the new coordinate system are the major points discussed in this paper. 6 refs., 1 fig

  17. Preliminary safety evaluation for the plutonium stabilization and packaging system

    International Nuclear Information System (INIS)

    Shapley, J.E.

    1997-01-01

    This Preliminary Safety Evaluation (PSE) describes and analyzes the installation and operation of the Plutonium Stabilization and Packaging System (SPS) at the Plutonium Finishing Plant (PFP). The SPS is a combination of components required to expedite the safe and timely storage of Plutonium (Pu) oxide. The SPS program will receive site Pu packages, process the Pu for storage, package the Pu into metallic containers, and safely store the containers in a specially modified storage vault. The location of the SPS will be in the 2736- ZB building and the storage vaults will be in the 2736-Z building of the PFP, as shown in Figure 1-1. The SPS will produce storage canisters that are larger than those currently used for Pu storage at the PFP. Therefore, the existing storage areas within the PFP secure vaults will require modification. Other modifications will be performed on the 2736-ZB building complex to facilitate the installation and operation of the SPS

  18. Preliminary Experimental Analysis of Soil Stabilizers for Contamination Control

    International Nuclear Information System (INIS)

    Lagos, L.; Varona, J.; Zidan, A.; Gudavalli, R.; Wu, Kuang-His

    2006-01-01

    A major focus of Department of Energy's (DOE's) environmental management mission at the Hanford site involves characterizing and remediating contaminated soil and groundwater; stabilizing contaminated soil; remediating disposal sites; decontaminating and decommissioning structures, and demolishing former plutonium production process buildings, nuclear reactors, and separation plants; maintaining inactive waste sites; transitioning facilities into the surveillance and maintenance program; and mitigating effects to biological and cultural resources from site development and environmental cleanup and restoration activities. For example, a total of 470,914 metric tons of contaminated soil from 100 Areas remediation activities were disposed at the Environmental Restoration Disposal Facility (ERDF) during 2004. The Applied Research Center (ARC) at Florida International University (FIU) is supporting the Hanford's site remediation program by analyzing the effectiveness of several soil stabilizers (fixatives) for contamination control during excavation activities. The study is focusing on determining the effects of varying soil conditions, temperature, humidity and wind velocity on the effectiveness of the candidate stabilizers. The test matrix consists of a soil penetration-depth study, wind tunnel experiments for determination of threshold velocity, and temperature and moisture-controlled drying/curing experiments. These three set of experiments are designed to verify performance metrics, as well as provide insight into what fundamental forces are altered by the use of the stabilizer. This paper only presents the preliminary results obtained during wind tunnel experiments using dry Hanford soil samples (with 2.7% moisture by weight). These dry soil samples were exposed to varying wind speeds from 2.22 m/sec to 8.88 m/sec. Furthermore, airborne particulate data was collected for the dry Hanford soil experiments using an aerosol analyzer instrument. (authors)

  19. Preliminary hazards analysis of thermal scrap stabilization system. Revision 1

    International Nuclear Information System (INIS)

    Lewis, W.S.

    1994-01-01

    This preliminary analysis examined the HA-21I glovebox and its supporting systems for potential process hazards. Upon further analysis, the thermal stabilization system has been installed in gloveboxes HC-21A and HC-21C. The use of HC-21C and HC-21A simplified the initial safety analysis. In addition, these gloveboxes were cleaner and required less modification for operation than glovebox HA-21I. While this document refers to glovebox HA-21I for the hazards analysis performed, glovebox HC-21C is sufficiently similar that the following analysis is also valid for HC-21C. This hazards analysis document is being re-released as revision 1 to include the updated flowsheet document (Appendix C) and the updated design basis (Appendix D). The revised Process Flow Schematic has also been included (Appendix E). This Current revision incorporates the recommendations provided from the original hazards analysis as well. The System Design Description (SDD) has also been appended (Appendix H) to document the bases for Safety Classification of thermal stabilization equipment

  20. Current state of copper stabilizers and methodology towards calculating risk

    CERN Document Server

    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...

  1. Preliminary core design calculations for the ACPR Upgrade

    International Nuclear Information System (INIS)

    Pickard, P.S.

    1976-01-01

    The goal of the Annular Core Pulse Reactor (ACPR) Upgrade design studies is to define a core configuration that provides a significant increase in pulse fluence and fission energy deposition. The reactor modification should provide as flat an energy deposition profile for experiments as feasible. The fuels examined in this study were UO 2 -BeO (5-15 w/o UO 2 ), UC-ZrC-C (200-500 mg U/cc) and U-ZrH 1.5 . The basic core concept examined was a two region core, - a high heat capacity inner core region surrounded by an outer U-ZrH 1.5 region. Survey core calculations utilizing 1D transport calculations and cross sections libraries derived from the ORNL-AMPX code examined relative fuel loadings, fuel temperatures, reactivity requirements and pulse performance improvement. Reference designs for all candidate fuels were defined utilizing 2D transport and Monte Carlo calculations. The performance implications of alternative core designs were also examined for the UO 2 -BeO and UC-ZrC-C fuel candidates. (author)

  2. Preliminary Results on Asymptotic Stabilization of Hamiltonian Systems with Nonholonomic Constraints

    NARCIS (Netherlands)

    Khennouf, H.; Canudas de Wit, C.; Schaft, A.J. van der

    1995-01-01

    This paper presents some preliminary results on asymptotic stabilization of nonholonomic mechanical systems using the Hamiltonian formulation proposed previously. Our work seeks to establish a general formulation for designing time-varying controllers for some mechanical system described in the

  3. East Area Irradiation Test Facility: Preliminary FLUKA calculations

    CERN Document Server

    Lebbos, E; Calviani, M; Gatignon, L; Glaser, M; Moll, M; CERN. Geneva. ATS Department

    2011-01-01

    In the framework of the Radiation to Electronics (R2E) mitigation project, the testing of electronic equipment in a radiation field similar to the one occurring in the LHC tunnel and shielded areas to study its sensitivity to single even upsets (SEU) is one of the main topics. Adequate irradiation test facilities are therefore required, and one installation is under consideration in the framework of the PS East area renovation activity. FLUKA Monte Carlo calculations were performed in order to estimate the radiation field which could be obtained in a mixed field facility using the slowly extracted 24 GeV/c proton beam from the PS. The prompt ambient dose equivalent as well as the equivalent residual dose rate after operation was also studied and results of simulations are presented in this report.

  4. Nuclear Characteristics of SPNDs and Preliminary Calculation of Hybrid Fixed Incore Detector with Monte Carlo Code

    International Nuclear Information System (INIS)

    Koo, Bon Seung; Lee, Kyung Hoon; Song, Jae Seung; Park, Sang Yoon

    2013-01-01

    In this paper, the basic nuclear characteristics of major emitter materials were surveyed. In addition, preliminary calculations of Cobalt-Vanadium fixed incore detector were performed using the Monte Carlo code. Calculational results were cross-checked by KARMA. KARMA is a two-dimensional multigroup transport theory code developed by the KAERI and approved by Korean regularity agency to be employed as a nuclear design tool for a Korean commercial pressurizer water reactor. The nuclear characteristics of the major emitter materials were surveyed, and preliminary calculations of the hybrid fixed incore detector were performed with the MCNP code. The eigenvalue and pin-by-pin fission power distributions were calculated and showed good agreement with the KARMA calculation results. As future work, gamma power distributions as well as several types of XS of the emitter, insulator, and collector regions for a Co-V ICI assembly will be evaluated and compared

  5. Recent Progress in MHD Stability Calculations of Compact Stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Redi, M.H.; Kessel, C.; Monticello, D.A.; Reiman, A.; Cooper, W.A.; Nuehrenberg, C.; Sanchez, R.; Ware, A.; Hirshman, S.P.; Spong, D.A.

    2000-01-01

    A key issue for compact stellarators is the stability of beta-limiting MHD modes, such as external kink modes driven by bootstrap current and pressure gradient. We report here recent progress in MHD stability studies for low-aspect-ratio Quasi-Axisymmetric Stellarators (QAS) and Quasi-Omnigeneous Stellarators (QOS). We find that the N = 0 periodicity-preserving vertical mode is significantly more stable in stellarators than in tokamaks because of the externally generated rotational transform. It is shown that both low-n external kink modes and high-n ballooning modes can be stabilized at high beta by appropriate 3D shaping without a conducting wall. The stabilization mechanism for external kink modes in QAS appears to be an enhancement of local magnetic shear due to 3D shaping. The stabilization of ballooning mode in QOS is related to a shortening of the normal curvature connection length

  6. MR imaging of prostate. Preliminary experience with calculated imaging in 28 cases

    International Nuclear Information System (INIS)

    Gevenois, P.A.; Van Regemorter, G.; Ghysels, M.; Delepaut, A.; Van Gansbeke, D.; Struyven, J.

    1988-01-01

    The majority of studies with MR imaging in prostate disease are based on a semiology obtained using images weighted in T1 and T2. A study was carried out to evaluate effects of images calculated in T1 and T2 obtained at 0.5T. This preliminary study concerns 28 prostate examinations with spin-echo acquisition and inversion-recuperation parameters, and provided images calculated in T1, weighted and calculated in T2. Images allowed detection and characterization of prostate lesions. However, although calculated images accentuate discrimination of the method, the weighted images conserve their place because of their improved spatial resolution [fr

  7. The study on length and diameter ratio of nail as preliminary design for slope stabilization

    Science.gov (United States)

    Gunawan, Indra; Silmi Surjandari, Niken; Muslih Purwana, Yusep

    2017-11-01

    Soil nailing technology has been widely applied in practice for reinforced slope. The number of studies for the effective design of nail-reinforced slopes has also increased. However, most of the previous study was focused on a safety factor of the slope; the ratio of length and diameter itself has likely never been studied before. The aim of this study is to relate the length and diameter ratio of the nail with the safety factor of the 20 m height of sand slope in the various angle of friction and steepness of the slope. Simplified Bishop method was utilized to analyze the safety factor of the slope. This study is using data simulation to calculate the safety factor of the slope with soil nailing reinforcement. The results indicate that safety factor of slope stability increases with the increase of length and diameter ratio of the nail. At any angle of friction and steepness of the slope, certain effective length and diameter ratio was obtain. These results may be considered as a preliminary design for slope stabilization.

  8. Preliminary integrated calculation of radionuclide cation and anion transport at Yucca Mountain using a geochemical model

    International Nuclear Information System (INIS)

    Birdsell, K.H.; Campbell, K.; Eggert, K.G.; Travis, B.J.

    1989-01-01

    This paper presents preliminary transport calculations for radionuclide movement at Yucca Mountain using preliminary data for mineral distributions, retardation parameter distributions, and hypothetical recharge scenarios. These calculations are not performance assessments, but are used to study the effectiveness of the geochemical barriers at the site at mechanistic level. The preliminary calculations presented have many shortcomings and should be viewed only as a demonstration of the modeling methodology. The simulations were run with TRACRN, a finite-difference porous flow and radionuclide transport code developed for the Yucca Mountain Project. Approximately 30,000 finite-difference nodes are used to represent the unsaturated and saturated zones underlying the repository in three dimensions. Sorption ratios for the radionuclides modeled are assumed to be functions of mineralogic assemblages of the underlying rock. These transport calculations present a representative radionuclide cation, 135 Cs and anion, 99 Tc. The effects on transport of many of the processes thought to be active at Yucca Mountain may be examined using this approach. The model provides a method for examining the integration of flow scenarios, transport, and retardation processes as currently understood for the site. It will also form the basis for estimates of the sensitivity of transport calculations to retardation processes. 11 refs., 17 figs., 1 tab

  9. Stability notions in synthetic graph generation: a preliminary study

    NARCIS (Netherlands)

    van Leeuwen, W.; Fletcher, G.H.L.; Yakovets, N.; Bonifati, A.; Markl, Volker; Orlando, Salvatore; Mitschang, Bernhard

    2017-01-01

    With the rise in adoption of massive graph data, it be- comes increasingly important to design graph processing algorithms which have predictable behavior as the graph scales. This work presents an initial study of stability in the context of a schema-driven synthetic graph generation. Specifically,

  10. Structures and Stability of Metal Amidoboranes (MAB): Density Functional Calculations

    International Nuclear Information System (INIS)

    Li Cailin; Wu Chaoling; Chen Yungui; Zhou Jingjing; Zheng Xin; Pang Lijuan; Deng Gang

    2010-01-01

    Molecule geometry structures, frequencies, and energetic stabilities of ammonia borane (AB, NH 3 BH 3 ) and metal amidoboranes (MAB, MNH 2 BH 3 ), formed by substituting H atom in AB with one of main group metal atoms, have been investigated by density-functional theory and optimized at the B3LYP levels with 6-311G++ (3df, 3pd) basic set. Their structural parameters and infrared spectrum characteristic peaks have been predicted, which should be the criterion of a successfully synthesized material. Several parameters such as binding energies, vibrational frequencies, and the energy gaps between the HOMO and the LUMO have been adopted to characterize and evaluate their structure stabilities. It is also found that the binding energies and HOMO-LUMO energy gaps of the MAB obviously change with the substitution of the atoms. MgAB has the lowest binding energy and is easier to decompose than any other substitutional structures under same conditions, while CaAB has the highest chemical activity. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Verification of EPA's " Preliminary remediation goals for radionuclides" (PRG) electronic calculator

    Energy Technology Data Exchange (ETDEWEB)

    Stagich, B. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-03-29

    The U.S. Environmental Protection Agency (EPA) requested an external, independent verification study of their “Preliminary Remediation Goals for Radionuclides” (PRG) electronic calculator. The calculator provides information on establishing PRGs for radionuclides at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites with radioactive contamination (Verification Study Charge, Background). These risk-based PRGs set concentration limits using carcinogenic toxicity values under specific exposure conditions (PRG User’s Guide, Section 1). The purpose of this verification study is to ascertain that the computer codes has no inherit numerical problems with obtaining solutions as well as to ensure that the equations are programmed correctly.

  12. Model for calculation of electrostatic contribution into protein stability

    Science.gov (United States)

    Kundrotas, Petras; Karshikoff, Andrey

    2003-03-01

    Existing models of the denatured state of proteins consider only one possible spatial distribution of protein charges and therefore are applicable to a limited number of cases. In this presentation a more general framework for the modeling of the denatured state is proposed. It is based on the assumption that the titratable groups of an unfolded protein can adopt a quasi-random distribution, restricted by the protein sequence. The model was tested on two proteins, barnase and N-terminal domain of the ribosomal protein L9. The calculated free energy of denaturation, Δ G( pH), reproduces the experimental data essentially better than the commonly used null approximation (NA). It was demonstrated that the seemingly good agreement with experimental data obtained by NA originates from the compensatory effect between the pair-wise electrostatic interactions and the desolvation energy of the individual sites. It was also found that the ionization properties of denatured proteins are influenced by the protein sequence.

  13. Preliminary Analysis of Slope Stability in Kuok and Surrounding Areas

    Directory of Open Access Journals (Sweden)

    Dewandra Bagus Eka Putra

    2016-12-01

    Full Text Available The level of slope influenced by the condition of the rocks beneath the surface. On high level of slopes, amount of surface runoff and water transport energy is also enlarged. This caused by greater gravity, in line with the surface tilt from the horizontal plane. In other words, topsoil eroded more and more. When the slope becomes twice as steep, then the amount of erosion per unit area be 2.0 - 2.5 times more. Kuok and surrounding area is the road access between the West Sumatra and Riau which plays an important role economies of both provinces. The purpose of this study is to map the locations that have fairly steep slopes and potential mode of landslides. Based on SRTM data obtained,  the roads in Kuok area has a minimum elevation of + 33 m and a maximum  + 217.329 m. Rugged road conditions with slope ranging from 24.08 ° to 44.68 ° causing this area having frequent landslides. The result of slope stability analysis in a slope near the Water Power Plant Koto Panjang, indicated that mode of active failure is toppling failure or rock fall and the potential zone of failure is in the center part of the slope.

  14. Dynamic stability calculations for power grids employing a parallel computer

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, K

    1982-06-01

    The aim of dynamic contingency calculations in power systems is to estimate the effects of assumed disturbances, such as loss of generation. Due to the large dimensions of the problem these simulations require considerable computing time and costs, to the effect that they are at present only used in a planning state but not for routine checks in power control stations. In view of the homogeneity of the problem, where a multitude of equal generator models, having different parameters, are to be integrated simultaneously, the use of a parallel computer looks very attractive. The results of this study employing a prototype parallel computer (SMS 201) are presented. It consists of up to 128 equal microcomputers bus-connected to a control computer. Each of the modules is programmed to simulate a node of the power grid. Generators with their associated control are represented by models of 13 states each. Passive nodes are complemented by 'phantom'-generators, so that the whole power grid is homogenous, thus removing the need for load-flow-iterations. Programming of microcomputers is essentially performed in FORTRAN.

  15. Recent improvements in the calculation of prompt fission neutron spectra: Preliminary results

    International Nuclear Information System (INIS)

    Madland, D.G.; LaBauve, R.J.; Nix, J.R.

    1989-01-01

    We consider three topics in the refinement and improvement of our original calculations of prompt fission neutron spectra. These are an improved calculation of the prompt fission neutron spectrum N(E) from the spontaneous fission of 252 Cf, a complete calculation of the prompt fission neutron spectrum matrix N(E,E n ) from the neutron-induced fission of 235 U, at incident neutron energies ranging from 0 to 15 MeV, and an assessment of the scission neutron component of the prompt fission neutron spectrum. Preliminary results will be presented and compared with experimental measurements and an evaluation. A suggestion is made for new integral cross section measurements. (author). 45 refs, 12 figs, 1 tab

  16. A preliminary pit slope stability study Kvanefjeld, South Greenland

    International Nuclear Information System (INIS)

    Kalvig, P.

    1983-11-01

    On the basis of 1300 field measurements of joint planes, four individual structural regions have been outlined in the Kvanefjeld area. Potential failure planes and planes which are unlikely to be involved in slope failures are identified. Failures seem, not likely to occur on walls dipping SW or NE respectively, but may occur on walls dipping NM. The factors of safety for each region are calculated in order to determine the sensibility of the overall slope to different overall slope angles. The factors of safety does only exceed the required factor of safety of 1.5 in one of the structural regions. Changing the overall pit slope inclination from 55deg to 45deg improves the security, but even still not satisfactorily for two of the regions. At 45deg overall pit slope in parts of the pit implies additional 14.3 x 10 6 tonnes of non-mineralized material to be mined, thus resulting in a total mineralized- to non-mineralized material ratio about 1.0: 1.7. (author)

  17. Computer Programs for Calculating and Plotting the Stability Characteristics of a Balloon Tethered in a Wind

    Science.gov (United States)

    Bennett, R. M.; Bland, S. R.; Redd, L. T.

    1973-01-01

    Computer programs for calculating the stability characteristics of a balloon tethered in a steady wind are presented. Equilibrium conditions, characteristic roots, and modal ratios are calculated for a range of discrete values of velocity for a fixed tether-line length. Separate programs are used: (1) to calculate longitudinal stability characteristics, (2) to calculate lateral stability characteristics, (3) to plot the characteristic roots versus velocity, (4) to plot the characteristic roots in root-locus form, (5) to plot the longitudinal modes of motion, and (6) to plot the lateral modes for motion. The basic equations, program listings, and the input and output data for sample cases are presented, with a brief discussion of the overall operation and limitations. The programs are based on a linearized, stability-derivative type of analysis, including balloon aerodynamics, apparent mass, buoyancy effects, and static forces which result from the tether line.

  18. PRELIMINARY STRUCTURAL OPTIMIZATION OF SOME FUMONISIN METABOLITES BY DENSITY FUNCTIONAL THEORY CALCULATION

    Directory of Open Access Journals (Sweden)

    István Bors

    2015-09-01

    Full Text Available Maize (Zea mays L. is often contaminated with Fusarium verticillioides. This harmful fungus produces fumonisins as secondary metabolites. These fumonisins can appear both free and hidden form in planta. The hidden form is usually bound covalently to cereal starch. From the hidden fumonisins, during enzymatic degradation, glycosides are formed, and the fumonisin is further decomposed during a de-esterification step. In this short communication some preliminary DFT calculated structural results which could be useful in the future to help to understand the van der Waals force controlled molecular interactions between these kinds of mycotoxin molecules and enzymes are demonstrated.

  19. Preliminary Calculations of Shutdown Dose Rate for the CTS Diagnostics System

    DEFF Research Database (Denmark)

    Klinkby, Esben Bryndt; Nonbøl, Erik; Lauritzen, Bent

    2015-01-01

    DTU and IST 2 are partners in the design of a collective Thomson Scattering (CTS) diagnostics for ITER through a contract with F4E. The CTS diagnostic utilizes probing radiation of ~60 GHz emitted into the plasma and, using a mirror, collects the scattered radiation by an array of receivers. Having...... on supplying input which affect the system design. Examples include: - Heatloads on plasma facing mirrors and preliminary stress and thermal analysis - Port plug cooling requirements and it's dependence on system design (in particular blanket cut-out) - Shutdown dose-rate calculations (relative analysis...

  20. Site Characterization and Preliminary Performance Assessment Calculation Applied To JAEA-Horonobe URL Site of Japan

    International Nuclear Information System (INIS)

    Lim, Doo Hyun; Hatanaka, Koichiro; Ishii, Eiichi

    2010-01-01

    JAEA-Horonobe Underground Research Laboratory (URL) is designed for research and development on high-level radioactive waste (HLW) repository in sedimentary rock. For a potential HLW repository, understanding and implementing fracturing and faulting system, with data from the site characterization, into the performance assessment is essential because fracture and fault will be the major conductors or barriers for the groundwater flow and radionuclide release. The objectives are i) quantitative derivation of characteristics and correlation of fracturing/faulting system with geologic and geophysics data obtained from the site characterization, and ii) preliminary performance assessment calculation with characterized site information

  1. Site Characterization and Preliminary Performance Assessment Calculation Applied To JAEA-Horonobe URL Site of Japan

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Doo Hyun [NE Union Hill Road, Suite 200, WA 98052 (United States); Hatanaka, Koichiro; Ishii, Eiichi [Japan Atomic Energy Agency, Hokkaido (Japan)

    2010-10-15

    JAEA-Horonobe Underground Research Laboratory (URL) is designed for research and development on high-level radioactive waste (HLW) repository in sedimentary rock. For a potential HLW repository, understanding and implementing fracturing and faulting system, with data from the site characterization, into the performance assessment is essential because fracture and fault will be the major conductors or barriers for the groundwater flow and radionuclide release. The objectives are i) quantitative derivation of characteristics and correlation of fracturing/faulting system with geologic and geophysics data obtained from the site characterization, and ii) preliminary performance assessment calculation with characterized site information

  2. Calculated Pourbaix Diagrams of Cubic Perovskites for Water Splitting: Stability Against Corrosion

    DEFF Research Database (Denmark)

    Castelli, Ivano Eligio; Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

    2014-01-01

    We use density functional theory calculations to investigate the stability of cubic perovskites for photo-electrochemical water splitting taking both materials in their bulk crystal structure and dissolved phases into account. The method is validated through a detailed comparison of the calculated...

  3. Stability calculation method of slope reinforced by prestressed anchor in process of excavation.

    Science.gov (United States)

    Li, Zhong; Wei, Jia; Yang, Jun

    2014-01-01

    This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical.

  4. Preliminary regulatory audit calculation for Shinkori Units 3 and 4 LBLOCA

    Energy Technology Data Exchange (ETDEWEB)

    Woo, S. W.; Kim, B. S.; Kim, J. K. (and others)

    2006-12-15

    The objective of this study is to perform a preliminary evaluation for Shinkori Units 3 and 4 LBLOCA by applying KINS Realistic Evaluation Methodology (REM). The following results were obtained: (1) From the evaluation for Shinkori Units 3 and 4 LBLOCA, the peak cladding temperature was evaluated to meet the regulatory requirement and the feasibility of the KINS-REM was identified. (2) The input decks that were developed in the previous studies, were reviewed and the evaluation model of the fluidic device was developed and applied for the audit calculation. (3) The treating method for the uncertainty of the gap conductance was developed and applied for the audit calculation. (4) The pre- and post-processing programs were developed for this study. (5) For the more detailed assessments, the information for the gap conductance, etc. should be improved and the effects of coolant bypass during blowdown, steam binding and so on were not sufficiently evaluated. KINS-REM should be advanced to evaluate these effects properly. The KINS methodology that was used in this study, can be further applied for independent regulatory audit calculations related to the licensing application on LOCA best estimate calculation.

  5. Improving the Output Power Stability of a High Concentration Photovoltaic System with Supercapacitors: A Preliminary Evaluation

    Directory of Open Access Journals (Sweden)

    Yu-Pei Huang

    2015-01-01

    Full Text Available The output power of a high concentration photovoltaic (HCPV system is very sensitive to fluctuating tracking errors and weather patterns. To help compensate this shortcoming, supercapacitors have been successfully incorporated into photovoltaic systems to improve their output power stability. This study examined the output power stability improvement of an HCPV module with a supercapacitor integrated into its circuit. Furthermore, the equivalent model of the experimental circuit is presented and analyzed. Experimental results suggest that integrating a supercapacitor into an HCPV module could improve its output power stability and further extend its acceptance angle. This paper provides preliminary data of the improvement and its evaluation method, which could be utilized for further improvements to an HCPV system.

  6. Stabilizing canonical-ensemble calculations in the auxiliary-field Monte Carlo method

    Science.gov (United States)

    Gilbreth, C. N.; Alhassid, Y.

    2015-03-01

    Quantum Monte Carlo methods are powerful techniques for studying strongly interacting Fermi systems. However, implementing these methods on computers with finite-precision arithmetic requires careful attention to numerical stability. In the auxiliary-field Monte Carlo (AFMC) method, low-temperature or large-model-space calculations require numerically stabilized matrix multiplication. When adapting methods used in the grand-canonical ensemble to the canonical ensemble of fixed particle number, the numerical stabilization increases the number of required floating-point operations for computing observables by a factor of the size of the single-particle model space, and thus can greatly limit the systems that can be studied. We describe an improved method for stabilizing canonical-ensemble calculations in AFMC that exhibits better scaling, and present numerical tests that demonstrate the accuracy and improved performance of the method.

  7. Preliminary long-term stability criteria for compressed air energy storage caverns in salt domes

    Energy Technology Data Exchange (ETDEWEB)

    Thoms, R.L.; Martinez, J.D.

    1978-08-01

    Air storage caverns, which are an essential and integral component of a CAES plant, should be designed and operated so as to perform satisfactorily over the intended life of the overall facility. It follows that the long-term ''stability'' of air storage caverns must be considered as a primary concern in projecting the satisfactory operation of CAES facilities. As used in the report, ''stability'' of a storage cavern implies the extent to which an acceptable amount of cavern storage volume can be utilized with routine maintenance for a specified time interval, e.g., 35 years. In this context, cavern stability is relative to both planned utilization and time interval of operation. The objective of the study was to review the existing literature and consult knowledgeable workers in the storage industry, and then report state-of-the-art findings relative to long-term stability of compressed air energy storage caverns in salt domes. Further, preliminary cavern stability criteria were to be presented in a form consistent with the amount of information available on cavern performance in salt domes. Another objective of the study was to outline a methodology for determining the long-term stability of site-specific CAES cavern systems in salt domes.

  8. The effect of walking speed on local dynamic stability is sensitive to calculation methods

    DEFF Research Database (Denmark)

    Stenum, Jan; Bruijn, Sjoerd M; Jensen, Bente Rona

    2014-01-01

    Local dynamic stability has been assessed by the short-term local divergence exponent (λS), which quantifies the average rate of logarithmic divergence of infinitesimally close trajectories in state space. Both increased and decreased local dynamic stability at faster walking speeds have been...... reported. This might pertain to methodological differences in calculating λS. Therefore, the aim was to test if different calculation methods would induce different effects of walking speed on local dynamic stability. Ten young healthy participants walked on a treadmill at five speeds (60%, 80%, 100%, 120......% and 140% of preferred walking speed) for 3min each, while upper body accelerations in three directions were sampled. From these time-series, λS was calculated by three different methods using: (a) a fixed time interval and expressed as logarithmic divergence per stride-time (λS-a), (b) a fixed number...

  9. Ontario electricity industry restructuring : preliminary asset valuation and calculation of stranded debt

    International Nuclear Information System (INIS)

    1998-01-01

    The rationale for restructuring Ontario's electricity industry was restated. Financial elements of the Government's White Paper on the electrical industry included the following: (1) establishing a level playing field on taxes and regulation, (2) restructuring Ontario Hydro into new companies with clear business mandates, and (3) taking action to put the new companies on solid financial ground. To achieve these objectives requires valuation of the new companies as a key part in the restructuring process. This Ministry of Finance document contains preliminary estimates of the total debt and liabilities of Ontario Hydro ($ 39.1 billion), the value of the new generation and service companies ($ 15.8 billion), and the stranded debt ($ 23.3 billion, less the value of dedicated revenue streams of $ 15.4 billion, equal to the residual stranded debt of $ 7.9 billion). The method by which the stranded debt was calculated is also described. It is stressed that the overriding principles governing the financial restructuring plan are to achieve restructuring without increasing electricity rates, to retain maximum value in the electricity sector until stranded debt is retired, and to recover stranded debt from the electricity sector and not from taxpayers. Ministry advisors indicate that these preliminary valuations would allow the new companies to operate as commercial companies in a competitive market and receive investment grade credit ratings. 44 figs

  10. Calculation and Simulation Study on Transient Stability of Power System Based on Matlab/Simulink

    Directory of Open Access Journals (Sweden)

    Shi Xiu Feng

    2016-01-01

    Full Text Available The stability of the power system is destroyed, will cause a large number of users power outage, even cause the collapse of the whole system, extremely serious consequences. Based on the analysis in single machine infinite system as an example, when at the f point two phase ground fault occurs, the fault lines on either side of the circuit breaker tripping resection at the same time,respectively by two kinds of calculation and simulation methods of system transient stability analysis, the conclusion are consistent. and the simulation analysis is superior to calculation analysis.

  11. Calculations of NTM stabilization in ITER-FEAT by ECCD with realistic antenna geometry

    International Nuclear Information System (INIS)

    Ramponi, G.; Nowak, S.; Lazzaro, E.; Giruzzi, G.; Bosia, G.

    2001-01-01

    Neoclassical Tearing Modes stabilization is one of the main purposes for the implementation of an Electron Cyclotron Current Drive system on ITER-FEAT. Previous estimates have shown that a wave power level of 20-30 MW should be appropriate for a substantial reduction of the (3,2) and/or (2,1) modes. Here detailed calculations are presented combining, for the first time, the following elements: i) realistic antenna geometry resulting from detailed study of the implementation in an ITER upper port; ii) Gaussian beam-tracing calculations; iii) 3D Fokker-Planck calculations of the driven current density profile; iv) island evolution calculation, including island rotation effects. The power level necessary for complete stabilization of NTMs is evaluated for the ITER FEAT reference scenarios and the chosen wave frequency of 170 GHz. Optimization as a function of the injection poloidal and toroidal angles is discussed

  12. Calculations of axisymmetric stability of tokamak plasmas with active and passive feedback

    International Nuclear Information System (INIS)

    Ward, D.J.; Jardin, S.C.; Cheng, C.Z.

    1991-07-01

    A new linear MHD stability code, NOVA-W, has been developed in order to study feedback stabilization of the axisymmetric mode in deformable tokamak plasmas. The NOVA-W code is a modification of the non-variational MHD stability code NOVA that includes the effects of resistive passive conductors and active feedback circuits. The vacuum calculation has been reformulated in terms of the perturbed poloidal flux to allow the inclusion of perturbed toroidal currents outside the plasma. The boundary condition at the plasma-vacuum interface relates the instability displacement to the perturbed poloidal flux. This allows a solution of the linear MHD stability equations with the feedback effects included. The passive stability predictions of the code have been tested both against a simplified analytic model and against a different numerical calculation for a realistic tokamak configuration. The comparisons demonstrate the accuracy of the NOVA-W results. Active feedback calculations are performed for the CIT tokamak design demonstrating the effect of varying the position of the flux loops that provide the measurements of vertical displacement. The results compare well with those computed earlier using a less efficient nonlinear code. 37 refs., 13 figs

  13. Applications of Laplace transform methods to airfoil motion and stability calculations

    Science.gov (United States)

    Edwards, J. W.

    1979-01-01

    This paper reviews the development of generalized unsteady aerodynamic theory and presents a derivation of the generalized Possio integral equation. Numerical calculations resolve questions concerning subsonic indicial lift functions and demonstrate the generation of Kutta waves at high values of reduced frequency, subsonic Mach number, or both. The use of rational function approximations of unsteady aerodynamic loads in aeroelastic stability calculations is reviewed, and a reformulation of the matrix Pade approximation technique is given. Numerical examples of flutter boundary calculations for a wing which is to be flight tested are given. Finally, a simplified aerodynamic model of transonic flow is used to study the stability of an airfoil exposed to supersonic and subsonic flow regions.

  14. Assessment of stability during gait in patients with spinal deformity-A preliminary analysis using the dynamic stability margin.

    Science.gov (United States)

    Simon, Anne-Laure; Lugade, Vipul; Bernhardt, Kathie; Larson, A Noelle; Kaufman, Kenton

    2017-06-01

    Daily living activities are dynamic, requiring spinal motion through space. Current assessment of spinal deformities is based on static measurements from full-spine standing radiographs. Tools to assess dynamic stability during gait might be useful to enhance the standard evaluation. The aim of this study was to evaluate gait dynamic imbalance in patients with spinal deformity using the dynamic stability margin (DSM). Twelve normal subjects and 17 patients with spinal deformity were prospectively recruited. A kinematic 3D gait analysis was performed for the control group (CG) and the spinal deformity group (SDG). The DSM (distance between the extrapolated center of mass and the base of support) and time-distance parameters were calculated for the right and left side during gait. The relationship between DSM and step length was assessed using three variables: gait stability, symmetry, and consistency. Variables' accuracy was validated by a discriminant analysis. Patients with spinal deformity exhibited gait instability according to the DSM (0.25m versus 0.31m) with decreased velocity (1.1ms -1 versus 1.3ms -1 ) and decreased step length (0.32m versus 0.38m). According to the discriminant analysis, gait stability was the more accurate variable (area under the curve AUC=0.98) followed by gait symmetry and consistency. However, gait consistency showed 100% of specificity, sensitivity, and accuracy of precision. The DSM showed that patients with spinal malalignment exhibit decreased gait stability, symmetry, and consistency besides gait time-distance parameter changes. Additional work is required to determine how to apply the DSM for preoperative and postoperative spinal deformity management. Copyright © 2017. Published by Elsevier B.V.

  15. Theoretical calculations of the thermodynamic stability of ionic substitutions in hydroxyapatite under an aqueous solution environment

    International Nuclear Information System (INIS)

    Matsunaga, Katsuyuki; Murata, Hidenobu; Shitara, Kazuki

    2010-01-01

    Defect formation energies in materials generally depend on chemical potentials determined by a chemical equilibrium condition. In particular, an aqueous solution environment is important for biomaterials such as hydroxyapatite studied here. Therefore, a methodology to obtain ionic chemical potentials under chemical equilibrium between solid and aqueous solution was introduced, and was applied to substitutional divalent cations formed via ion exchange with Ca 2+ in hydroxyapatite. The calculated ranking of the stability of substitutional cations in HAp was in good agreement with the experimentally observed trend. The present theoretical approach would be useful to explore the thermodynamic stability of defects in materials subjected to an aqueous solution environment.

  16. First-principles calculation of the structural stability of 6d transition metals

    International Nuclear Information System (INIS)

    Oestlin, A.; Vitos, L.

    2011-01-01

    The phase stability of the 6d transition metals (elements 103-111) is investigated using first-principles electronic-structure calculations. Comparison with the lighter transition metals reveals that the structural sequence trend is broken at the end of the 6d series. To account for this anomalous behavior, the effect of relativity on the lattice stability is scrutinized, taking different approximations into consideration. It is found that the mass-velocity and Darwin terms give important contributions to the electronic structure, leading to changes in the interstitial charge density and, thus, in the structural energy difference.

  17. Calculation of Flexible Bus-Bars Electrodynamic Stability with Application of Implicit Scheme

    Directory of Open Access Journals (Sweden)

    Y. G. Panamarenka

    2008-01-01

    Full Text Available A numerical method for calculation of open-air substations’ flexible bus-bars dynamic at short-circuit has been improved on equations of a flexible elastic string with application of an implicit scheme. On the basis of the numerical method a computer program FLEBUS for calculation of substations’ flexible bus-bars dynamic at short-circuit has been developed. An approbation and an estimation of calculation result reliability have been carried out in accordance with the program while using experimental data. On the basis of the obtained information it is possible to assert that the developed program is an independent tool for calculation of electrodynamic stability of substations’ flexible bus-bars.

  18. Aqueous Stability of Alkali Superionic Conductors from First-Principles Calculations

    International Nuclear Information System (INIS)

    Radhakrishnan, Balachandran; Ong, Shyue Ping

    2016-01-01

    Ceramic alkali superionic conductor solid electrolytes (SICEs) play a prominent role in the development of rechargeable alkali-ion batteries, ranging from replacement of organic electrolytes to being used as separators in aqueous batteries. The aqueous stability of SICEs is an important property in determining their applicability in various roles. In this work, we analyze the aqueous stability of twelve well-known Li-ion and Na-ion SICEs using Pourbaix diagrams constructed from first-principles calculations. We also introduce a quantitative free-energy measure to compare the aqueous stability of SICEs under different environments. Our results show that though oxides are, in general, more stable in aqueous environments than sulfides and halide-containing chemistries, the cations present play a crucial role in determining whether solid phases are formed within the voltage and pH ranges of interest.

  19. Verification of EPA's ''Preliminary Remediation Goals for radionuclides'' (PRG) electronic calculator

    Energy Technology Data Exchange (ETDEWEB)

    Jannik, Tim [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Stagich, Brooke [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-28

    The U.S. Environmental Protection Agency (EPA) requested an external, independent verification study of their updated “Preliminary Remediation Goals for Radionuclides” (PRG) electronic calculator. The calculator provides PRGs for radionuclides that are used as a screening tool at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act (RCRA) sites. These risk-based PRGs establish concentration limits under specific exposure scenarios. The purpose of this verification study is to determine that the calculator has no inherit numerical problems with obtaining solutions as well as to ensure that the equations are programmed correctly. There are 167 equations used in the calculator. To verify the calculator, all equations for each of seven receptor types (resident, construction worker, outdoor and indoor worker, recreator, farmer, and composite worker) were hand calculated using the default parameters. The same four radionuclides (Am-241, Co-60, H-3, and Pu-238) were used for each calculation for consistency throughout.

  20. New Systematic CFD Methods to Calculate Static and Single Dynamic Stability Derivatives of Aircraft

    Directory of Open Access Journals (Sweden)

    Bai-gang Mi

    2017-01-01

    Full Text Available Several new systematic methods for high fidelity and reliability calculation of static and single dynamic derivatives are proposed in this paper. Angle of attack step response is used to obtain static derivative directly; then translation acceleration dynamic derivative and rotary dynamic derivative can be calculated by employing the step response motion of rate of the angle of attack and unsteady motion of pitching angular velocity step response, respectively. Longitudinal stability derivative calculations of SACCON UCAV are taken as test cases for validation. Numerical results of all cases achieve good agreement with reference values or experiments data from wind tunnel, which indicate that the proposed methods can be considered as new tools in the process of design and production of advanced aircrafts for their high efficiency and precision.

  1. Stability analysis of a deterministic dose calculation for MRI-guided radiotherapy

    Science.gov (United States)

    Zelyak, O.; Fallone, B. G.; St-Aubin, J.

    2018-01-01

    Modern effort in radiotherapy to address the challenges of tumor localization and motion has led to the development of MRI guided radiotherapy technologies. Accurate dose calculations must properly account for the effects of the MRI magnetic fields. Previous work has investigated the accuracy of a deterministic linear Boltzmann transport equation (LBTE) solver that includes magnetic field, but not the stability of the iterative solution method. In this work, we perform a stability analysis of this deterministic algorithm including an investigation of the convergence rate dependencies on the magnetic field, material density, energy, and anisotropy expansion. The iterative convergence rate of the continuous and discretized LBTE including magnetic fields is determined by analyzing the spectral radius using Fourier analysis for the stationary source iteration (SI) scheme. The spectral radius is calculated when the magnetic field is included (1) as a part of the iteration source, and (2) inside the streaming-collision operator. The non-stationary Krylov subspace solver GMRES is also investigated as a potential method to accelerate the iterative convergence, and an angular parallel computing methodology is investigated as a method to enhance the efficiency of the calculation. SI is found to be unstable when the magnetic field is part of the iteration source, but unconditionally stable when the magnetic field is included in the streaming-collision operator. The discretized LBTE with magnetic fields using a space-angle upwind stabilized discontinuous finite element method (DFEM) was also found to be unconditionally stable, but the spectral radius rapidly reaches unity for very low-density media and increasing magnetic field strengths indicating arbitrarily slow convergence rates. However, GMRES is shown to significantly accelerate the DFEM convergence rate showing only a weak dependence on the magnetic field. In addition, the use of an angular parallel computing strategy

  2. Corrigendum to "Stability analysis of a deterministic dose calculation for MRI-guided radiotherapy".

    Science.gov (United States)

    Zelyak, Oleksandr; Fallone, B Gino; St-Aubin, Joel

    2018-03-12

    Modern effort in radiotherapy to address the challenges of tumor localization and motion has led to the development of MRI guided radiotherapy technologies. Accurate dose calculations must properly account for the effects of the MRI magnetic fields. Previous work has investigated the accuracy of a deterministic linear Boltzmann transport equation (LBTE) solver that includes magnetic field, but not the stability of the iterative solution method. In this work, we perform a stability analysis of this deterministic algorithm including an investigation of the convergence rate dependencies on the magnetic field, material density, energy, and anisotropy expansion. The iterative convergence rate of the continuous and discretized LBTE including magnetic fields is determined by analyzing the spectral radius using Fourier analysis for the stationary source iteration (SI) scheme. The spectral radius is calculated when the magnetic field is included (1) as a part of the iteration source, and (2) inside the streaming-collision operator. The non-stationary Krylov subspace solver GMRES is also investigated as a potential method to accelerate the iterative convergence, and an angular parallel computing methodology is investigated as a method to enhance the efficiency of the calculation. SI is found to be unstable when the magnetic field is part of the iteration source, but unconditionally stable when the magnetic field is included in the streaming-collision operator. The discretized LBTE with magnetic fields using a space-angle upwind stabilized discontinuous finite element method (DFEM) was also found to be unconditionally stable, but the spectral radius rapidly reaches unity for very low density media and increasing magnetic field strengths indicating arbitrarily slow convergence rates. However, GMRES is shown to significantly accelerate the DFEM convergence rate showing only a weak dependence on the magnetic field. In addition, the use of an angular parallel computing strategy

  3. Stability analysis of a deterministic dose calculation for MRI-guided radiotherapy.

    Science.gov (United States)

    Zelyak, O; Fallone, B G; St-Aubin, J

    2017-12-14

    Modern effort in radiotherapy to address the challenges of tumor localization and motion has led to the development of MRI guided radiotherapy technologies. Accurate dose calculations must properly account for the effects of the MRI magnetic fields. Previous work has investigated the accuracy of a deterministic linear Boltzmann transport equation (LBTE) solver that includes magnetic field, but not the stability of the iterative solution method. In this work, we perform a stability analysis of this deterministic algorithm including an investigation of the convergence rate dependencies on the magnetic field, material density, energy, and anisotropy expansion. The iterative convergence rate of the continuous and discretized LBTE including magnetic fields is determined by analyzing the spectral radius using Fourier analysis for the stationary source iteration (SI) scheme. The spectral radius is calculated when the magnetic field is included (1) as a part of the iteration source, and (2) inside the streaming-collision operator. The non-stationary Krylov subspace solver GMRES is also investigated as a potential method to accelerate the iterative convergence, and an angular parallel computing methodology is investigated as a method to enhance the efficiency of the calculation. SI is found to be unstable when the magnetic field is part of the iteration source, but unconditionally stable when the magnetic field is included in the streaming-collision operator. The discretized LBTE with magnetic fields using a space-angle upwind stabilized discontinuous finite element method (DFEM) was also found to be unconditionally stable, but the spectral radius rapidly reaches unity for very low-density media and increasing magnetic field strengths indicating arbitrarily slow convergence rates. However, GMRES is shown to significantly accelerate the DFEM convergence rate showing only a weak dependence on the magnetic field. In addition, the use of an angular parallel computing strategy

  4. External radiotherapy in macular degeneration: Our technique, dosimetric calculation, and preliminary results

    International Nuclear Information System (INIS)

    Akmansu, M.; Dirican, Bahar; Oeztuerk, Berrin; Egehan, Ibrahim; Subasi, Mahmut; Or, Meral

    1998-01-01

    Purpose: This study was performed to determine the toxicity and efficacy of external-beam radiotherapy in patients with age-related subfoveal neovascularization. Methods and Materials: Between January 1996 and September 1996, 25 patients with a mean age of 70.5 (60-84) years were enrolled. All patients underwent fluorescein angiographic evaluation and documentation of their neovascular disease prior to irradiation. A total of 25 patients were treated with a total dose of 12 Gy in 6 fractions over 8 days. We used a lens-sparing technique and patients were treated with a single lateral 6-MV photon beam. To assess the risk of radiation carcinogenesis after treatment of age-related subfoveal neovascularization, we estimated the effective dose for a standard patient on the basis of tissue-weighting factors as defined by the International Commission on Radiological Protection (ICRP). The calculations were made with TLD on a male randophantom. The lens dose was found to be 0.217 Gy per fraction. Results: No significant acute morbidity was noted. Visual acuity was maintained or improved in 76% and 80% of treated patients at their 1- and 3-month follow-up examinations, respectively. On angiographic imaging, there was stabilization of subfoveal neovascular membranes in 23 patients (92%) at 3 months after irradiation. Conclusion: Our observations on these 25 patients in this study indicate that many patients will have improved or stable vision after radiotherapy treatment with low-dose irradiation

  5. Linking soil permeability and soil aggregate stability with root development: a pots experiment (preliminary results)

    Science.gov (United States)

    Vergani, Chiara; Graf, Frank; Gerber, Werner

    2015-04-01

    humidity of 75%, and at a night temperature of 17°C and relative humidity of 55% , with 15 hours of light per day. Four different growing periods have been distinguished (1, 2, 4 and 8 months). For each growing period 7 planted replicates have been set up, as well as 3 control pots with only bare soil treated the same way as the planted pots. After each growing period, the soil permeability was measured by means of a falling head procedure (Bagarello and Iovino, 2010) directly in the pots. Furthermore, soil aggregate stability was determined on soil samples applying a wet sieving method (Graf and Frei, 2013). Subsequently, root systems were collected and analyzed using different image software (Smartroot and Winrhizo). The permeability and soil aggregate stability values were finally linked with the root development stage and compared with field data coming from long-term stabilized slopes. Preliminary analysis reveals no significant influence of alder roots on both soil aggregate stability and hydraulic conductivity of soil after the one month growing period compared to the control. However, after two months we observed a decrease in the hydraulic conductivity values.

  6. CCSD(T) calculations of stabilities and properties of confined systems

    Energy Technology Data Exchange (ETDEWEB)

    Holka, F.; Urban, M. [Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Bottova 25, SK-917 24 Trnava (Slovakia); Melicherčík, M.; Neogrády, P. [Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynská dolina, SK-842 15 Bratislava (Slovakia); Paldus, J. [Department of Applied Mathematics, University of Waterloo, N2L 3G1, Ontario (Canada)

    2015-01-22

    We analyze energies, electron affinities and polarizabilities of small anions exposed to an external confinement. The second electron in free O{sup 2−} and S{sup 2−} anions is unbound. We investigate the stabilizing effect of the spherical harmonic-oscillator confining potential ω. on these anions employing the Hartree-Fock stability analysis as introduced by Čížek and Paldus. With increasing strength of the external harmonic-oscillator confinement potential ω the broken symmetry (BS) solutions are systematically eliminated. For ω larger than 0.1 all BS solutions for O{sup 2−} disappear. For ω larger than 0.13 the CCSD(T) energy of O{sup 2−} becomes more negative than the energy of the singly charged O{sup −} anion. We relate the harmonic-oscillator confining potential to a crystalline environment in which the O{sup 2−} and S{sup 2−} anions are stable. We also present a model allowing calculations of the in-crystal polarizabilities of anions. The model is based on CCSD(T) calculations of static polarizabilities of selected anions exposed to the spherical harmonic-oscillator confining potential ω This artificial confinement potential ω is then related to the ionic radii of the cation in representative crystal lattices. We investigate the polarizability of O{sup 2−} and S{sup 2−} anions in MgO, MgS, CaO, CaS, SrO, SrS, BaO and BaS crystals. We compare our results with alternative models for in-crystal polarizabilities. External confinement also stabilizes the uracil anion U{sup −}, as is shown by calculations with a stepwise micro-hydration of U{sup −}. Upon hydration is the CCSD(T) adiabatic electron affinity (AEA) of uracil enhanced by about 250 up to 570 meV in comparison with AEA of the isolated molecule, depending on the geometry of the hydrated uracil anion complex. We tried to find an analogy of the stabilization effect of the external confinement on the otherwise unstable anions. In uracil and its anion is the external

  7. Stability, electronic and thermodynamic properties of aluminene from first-principles calculations

    International Nuclear Information System (INIS)

    Yuan, Junhui; Yu, Niannian; Xue, Kanhao; Miao, Xiangshui

    2017-01-01

    Highlights: • We have predicted two NEW stable phases of atomic layer aluminum, buckled and 8-Pmmn aluminene. • We have revealed the electronic structures and bonding characteristics of aluminene. • Thermodynamic properties of aluminene were investigated based on phonon properties. - Abstract: Using first-principles calculations based on density functional theory (DFT), we have investigated the structure stability and electronic properties of both buckled and 8-Pmmn phase aluminene. Phonon dispersion analysis reveals that the buckled and 8-Pmmn aluminene are dynamically stable. The band structure shows that both the buckled and 8-Pmmn aluminene exhibit metallic behavior. Finally, the thermodynamic properties are investigated based on phonon properties.

  8. Stability, electronic and thermodynamic properties of aluminene from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Junhui [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Yu, Niannian [School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Xue, Kanhao, E-mail: xkh@hust.edu.cn [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Miao, Xiangshui [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2017-07-01

    Highlights: • We have predicted two NEW stable phases of atomic layer aluminum, buckled and 8-Pmmn aluminene. • We have revealed the electronic structures and bonding characteristics of aluminene. • Thermodynamic properties of aluminene were investigated based on phonon properties. - Abstract: Using first-principles calculations based on density functional theory (DFT), we have investigated the structure stability and electronic properties of both buckled and 8-Pmmn phase aluminene. Phonon dispersion analysis reveals that the buckled and 8-Pmmn aluminene are dynamically stable. The band structure shows that both the buckled and 8-Pmmn aluminene exhibit metallic behavior. Finally, the thermodynamic properties are investigated based on phonon properties.

  9. Correlation between calculated molecular descriptors of excipient amino acids and experimentally observed thermal stability of lysozyme

    DEFF Research Database (Denmark)

    Meng-Lund, Helena; Friis, Natascha; van de Weert, Marco

    2017-01-01

    for lysozyme in combination with 13 different amino acids using high throughput fluorescence spectroscopy and kinetic static light scattering measurements. On the theoretical side, around 200 2D and 3D molecular descriptors were calculated based on the amino acids' chemical structure. Multivariate data...... prominent stabilizing factor for both responses, whereas hydrophilic surface properties and high molecular mass density mostly had a positive influence on the unfolding temperature. A high partition coefficient (logP(o/w)) was identified as the most prominent destabilizing factor for both responses...

  10. Method for stability analysis based on the Floquet theory and Vidyn calculations

    Energy Technology Data Exchange (ETDEWEB)

    Ganander, Hans

    2005-03-01

    This report presents the activity 3.7 of the STEM-project Aerobig and deals with aeroelastic stability of the complete wind turbine structure at operation. As a consequence of the increase of sizes of wind turbines dynamic couplings are being more important for loads and dynamic properties. The steady ambition to increase the cost competitiveness of wind turbine energy by using optimisation methods lowers design margins, which in turn makes questions about stability of the turbines more important. The main objective of the project is to develop a general stability analysis tool, based on the VIDYN methodology regarding the turbine dynamic equations and the Floquet theory for the stability analysis. The reason for selecting the Floquet theory is that it is independent of number of blades, thus can be used for 2 as well as 3 bladed turbines. Although the latter ones are dominating on the market, the former has large potential when talking about offshore large turbines. The fact that cyclic and individual blade pitch controls are being developed as a mean for reduction of fatigue also speaks for general methods as Floquet. The first step of a general system for stability analysis has been developed, the code VIDSTAB. Together with other methods, as the snap shot method, the Coleman transformation and the use of Fourier series, eigenfrequences and modes can be analysed. It is general with no restrictions on the number of blades nor the symmetry of the rotor. The derivatives of the aerodynamic forces are calculated numerically in this first version. Later versions would include state space formulations of these forces. This would also be the case for the controllers of turbine rotation speed, yaw direction and pitch angle.

  11. A preliminary stability analysis of MYRRHA Primary Heat Exchanger two-phase tube bundle

    Energy Technology Data Exchange (ETDEWEB)

    Castelliti, Diego [Studiecentrum voor kernenergie – Centre d’étude de l’énergie nucléaire (SCK-CEN), Boeretang 200, Mol (Belgium); GeNERG – DIME/TEC, University of Genova, Via all’Opera Pia 15/a, 16145 Genova (Italy); Lomonaco, Guglielmo, E-mail: guglielmo.lomonaco@unige.it [GeNERG – DIME/TEC, University of Genova, Via all’Opera Pia 15/a, 16145 Genova (Italy); INFN, Via Dodecaneso 33, 16146 Genova (Italy)

    2016-08-15

    the channel. The stability assessment should take in consideration all the possible reactor operational power levels in order to prove the stable behavior under all operational conditions. The tube bundle stability assessment has been carried out by following a similar procedure used for BWR fuel channels, through a specific RELAP5-3D model representing the PHX and able to evaluate the propagation of a density wave in the tube length. A series of suitable boundary conditions, on both primary and secondary side, and perturbation triggers have been foreseen into the model, so to discover all kind of unstable behavior and to dimension the needed orifice to guarantee the flow stability in all operating conditions. The PHX stability analysis is initially performed on the original tube bundle without the adoption of any stabilizing devices, in order to check the natural behavior of the system. The possible adoption and design of an orifice is then conducted on the basis of this preliminary study. The system response against the various types of instabilities, before the introduction of an orifice, is not completely satisfactory: a stable flow is found within certain specific system parameters ranges. After the introduction of a suitable orifice, the system behavior becomes stable under all operating conditions against all types of two-phase flow instabilities.

  12. Preliminary assessment of potential underground stability (wedge and spalling) at Forsmark, Simpevarp and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Derek [Univ. of Alberta, Edmonton (Canada). Geotechnical Engineering

    2005-12-15

    In SKB's Underground Design Premises the objective in the early design phase is to estimate if there is sufficient space for the repository at a site. One of the conditions that could limit the space available is stability of the underground openings, i.e., deposition tunnels and deposition boreholes. The purpose of this report is to provide a preliminary assessment of the potential for wedge instability and spalling that may be encountered at the Forsmark, Simpevarp and Laxemar sites based on information from the site investigations program up to July 30, 2004. The rock mass spalling strength was defined using the in-situ results from SKB's Aespoe Pillar Stability Experiment and AECL's Mine-by Experiment. These experiments suggest that the rock mass spalling strength for crystalline rocks can be estimated as 0.57 of the mean laboratory uniaxial compressive strength. A probability-based methodology utilizing this in-situ rock mass spalling strength has been developed for assessing the risk for spalling in a repository at the Forsmark, Simpevarp and Laxemar sites. The in-situ stresses and the uniaxial compressive strength data from these sites were used as the bases for the analyses. Preliminary findings from all sites suggest that, generally, the risk for spalling increases as the depth of the repository increases, simply because the stress magnitudes increase with depth. The depth at which the risk for spalling is significant, depends on the individual sites which are discussed below. The greatest uncertainty in the spalling analyses for Forsmark is related to the uncertainty in the horizontal stress magnitudes and associated stress gradients with depth. The confidence in these analyses can only be increased by increasing the confidence in the stress and geology model for the site. From the analyses completed it appears that spalling in the deposition tunnels can be controlled by orienting the tunnels approximately parallel to the maximum horizontal

  13. Preliminary decay heat calculations for the fuel loaded irradiation loop device of the RMB multipurpose Brazilian reactor

    Energy Technology Data Exchange (ETDEWEB)

    Campolina, Daniel; Costa, Antonio Carlos L. da; Andrade, Edison P., E-mail: campolina@cdtn.br, E-mail: aclp@cdtn.br, E-mail: epa@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (SETRE/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Tecnologia de Reatores

    2017-07-01

    The structuring project of the Brazilian Multipurpose Reactor (RMB) is responsible for meeting the capacity to develop and test materials and nuclear fuel for the Brazilian Nuclear Program. An irradiation test device (Loop) capable of performing fuel test for power reactor rods is being conceived for RMB reflector. In this work preliminary neutronic calculations have been carried out in order to determine parameters to the cooling system of the Loop basic design. The heat released as a result of radioactive decay of fuel samples was calculated using ORIGEN-ARP and it resulted less than 200 W after 1 hour of irradiation interruption. (author)

  14. Energetics and stability of azulene: From experimental thermochemistry to high-level quantum chemical calculations

    International Nuclear Information System (INIS)

    Sousa, Clara C.S.; Matos, M. Agostinha R.; Morais, Victor M.F.

    2014-01-01

    Highlights: • Experimental standard molar enthalpy of formation, sublimation azulene. • Mini-bomb combustion calorimetry, sublimation Calvet microcalorimetry. • High level composite ab initio calculations. • Computational estimate of the enthalpy of formation of azulene. • Discussion of stability and aromaticity of azulene. - Abstract: The standard (p 0 = 0.1 MPa) molar enthalpy of formation for crystalline azulene was derived from the standard molar enthalpy of combustion, in oxygen, at T = 298.15 K, measured in a mini-bomb combustion calorimeter (aneroid isoperibol calorimeter) and the standard molar enthalpy of sublimation, at T = 298.15 K, measured by Calvet microcalorimetry. From these experiments, the standard molar enthalpy of formation of azulene in the gaseous phase at T = 298.15 K was calculated. In addition, very accurate quantum chemical calculations at the G3 and G4 composite levels of calculation were conducted in order to corroborate our experimental findings and further clarify and establish the definitive standard enthalpy of formation of this interesting non-benzenoid hydrocarbon

  15. Improving the calculated core stability by the core nuclear design optimization

    International Nuclear Information System (INIS)

    Partanen, P.

    1995-01-01

    Three different equilibrium core loadings for TVO II reactor have been generated in order to improve the core stability properties at uprated power level. The reactor thermal power is assumed to be uprated from 2160 MW th to 2500 MW th , which moves the operating point after a rapid pump rundown where the core stability has been calculated from 1340 MW th and 3200 kg/s to 1675 MW th and 4000 kg/s. The core has been refuelled with ABB Atom Svea-100 -fuel, which has 3,64% w/o U-235 average enrichment in the highly enriched zone. PHOENIX lattice code has been used to provide the homogenized nuclear constants. POLCA4 static core simulator has been used for core loadings and cycle simulations and RAMONA-3B program for simulating the dynamic response to the disturbance for which the stability behaviour has been evaluated. The core decay ratio has been successfully reduced from 0,83 to 0,55 mainly by reducing the power peaking factors. (orig.) (7 figs., 1 tab.)

  16. SU-C-204-03: DFT Calculations of the Stability of DOTA-Based-Radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Khabibullin, A.R.; Woods, L.M. [University of South Florida, Tampa, Florida (United States); Karolak, A.; Budzevich, M.M.; Martinez, M.V. [H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States); McLaughlin, M.L.; Morse, D.L. [University of South Florida, Tampa, Florida (United States); H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida (United States)

    2016-06-15

    Purpose: Application of the density function theory (DFT) to investigate the structural stability of complexes applied in cancer therapy consisting of the 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelated to Ac225, Fr221, At217, Bi213, and Gd68 radio-nuclei. Methods: The possibility to deliver a toxic payload directly to tumor cells is a highly desirable aim in targeted alpha particle therapy. The estimation of bond stability between radioactive atoms and the DOTA chelating agent is the key element in understanding the foundations of this delivery process. Thus, we adapted the Vienna Ab-initio Simulation Package (VASP) with the projector-augmented wave method and a plane-wave basis set in order to study the stability and electronic properties of DOTA ligand chelated to radioactive isotopes. In order to count for the relativistic effect of radioactive isotopes we included Spin-Orbit Coupling (SOC) in the DFT calculations. Five DOTA complex structures were represented as unit cells, each containing 58 atoms. The energy optimization was performed for all structures prior to calculations of electronic properties. Binding energies, electron localization functions as well as bond lengths between atoms were estimated. Results: Calculated binding energies for DOTA-radioactive atom systems were −17.792, −5.784, −8.872, −13.305, −18.467 eV for Ac, Fr, At, Bi and Gd complexes respectively. The displacements of isotopes in DOTA cages were estimated from the variations in bond lengths, which were within 2.32–3.75 angstroms. The detailed representation of chemical bonding in all complexes was obtained with the Electron Localization Function (ELF). Conclusion: DOTA-Gd, DOTA-Ac and DOTA-Bi were the most stable structures in the group. Inclusion of SOC had a significant role in the improvement of DFT calculation accuracy for heavy radioactive atoms. Our approach is found to be proper for the investigation of structures with DOTA

  17. Vibrational spectrum, ab initio calculations, conformational stabilities and assignment of fundamentals of 1,2-dibromopropane

    Science.gov (United States)

    LaPlante, Arthur J.; Stidham, Howard D.

    2009-10-01

    The mid and far infrared and the Raman spectrum of 1,2-dibromopropane is reported in solid, liquid and gas. Several bands reported by earlier workers are not present in the spectrum of the purified material. Ab initio calculations of optimized geometry, energy, dipole moment, molar volume, vibrational spectrum and normal coordinate calculation were performed using the density functional B3LYP/6-311++g(3df,2pd), and the results used to assist a complete assignment of the 81 fundamental modes of vibrations of the three conformers of 1,2-dibromopropane. Relative energies found conformer A the lowest with G and G' at 815.6 and 871.4 cm -1 higher. The temperature dependence of the Raman spectrum of the liquid was investigated in the CCC bending region and the relative energies determined. It was found that the G' and G conformers lie 236 ± 11 and 327 ±11 cm -1, respectively above the A conformer, leading to the room temperature composition of the liquid as A, 65 ± 1; G', 21 ± 1; G, 14 ± 1%. It is apparent that the calculated highest energy conformer G' is stabilized more than the G conformer in the liquid. The G' conformer has the lowest molar volume effectively changing the interaction distance between conformers in the liquid, and enhancing the effect of its dipole moment.

  18. First-principles calculations of BC{sub 4}N nanostructures: stability and electronic structure

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, A.; Azevedo, S. [Universidade Federal da Paraiba, CCEN, Departamento de Fisica, Joao Pessoa, PB (Brazil); Machado, M. [Universidade Federal de Pelotas, Departamento de Fisica, Pelotas, RS (Brazil); Kaschny, J.R. [Instituto Federal da Bahia-Campus Vitoria da Conquista, Vitoria da Conquista, BA (Brazil)

    2012-07-15

    In this work, we apply first-principles methods to investigate the stability and electronic structure of BC{sub 4}N nanostructures which were constructed from hexagonal graphite layers where substitutional nitrogen and boron atoms are placed at specific sites. These layers were rolled up to form zigzag and armchair nanotubes, with diameters varying from 7 to 12 A, or cut and bent to form nanocones, with 60 and 120 disclination angles. The calculation results indicate that the most stable structures are the ones which maximize the number of B-N and C-C bonds. It is found that the zigzag nanotubes are more stable than the armchair ones, where the strain energy decreases with increasing tube diameter D, following a 1/D {sup 2} law. The results show that the 60 disclination nanocones are the most stable ones. Additionally, the calculated electronic properties indicate a semiconducting behavior for all calculated structures, which is intermediate to the typical behaviors found for hexagonal boron nitride and graphene. (orig.)

  19. Measuring and Modeling Root Distribution and Root Reinforcement in Forested Slopes for Slope Stability Calculations

    Science.gov (United States)

    Cohen, D.; Giadrossich, F.; Schwarz, M.; Vergani, C.

    2016-12-01

    Roots provide mechanical anchorage and reinforcement of soils on slopes. Roots also modify soil hydrological properties (soil moisture content, pore-water pressure, preferential flow paths) via subsurface flow path associated with root architecture, root density, and root-size distribution. Interactions of root-soil mechanical and hydrological processes are an important control of shallow landslide initiation during rainfall events and slope stability. Knowledge of root-distribution and root strength are key components to estimate slope stability in vegetated slopes and for the management of protection forest in steep mountainous area. We present data that show the importance of measuring root strength directly in the field and present methods for these measurements. These data indicate that the tensile force mobilized in roots depends on root elongation (a function of soil displacement), root size, and on whether roots break in tension of slip out of the soil. Measurements indicate that large lateral roots that cross tension cracks at the scarp are important for slope stability calculations owing to their large tensional resistance. These roots are often overlooked and when included, their strength is overestimated because extrapolated from measurements on small roots. We present planned field experiments that will measure directly the force held by roots of different sizes during the triggering of a shallow landslide by rainfall. These field data are then used in a model of root reinforcement based on fiber-bundle concepts that span different spacial scales, from a single root to the stand scale, and different time scales, from timber harvest to root decay. This model computes the strength of root bundles in tension and in compression and their effect on soil strength. Up-scaled to the stand the model yields the distribution of root reinforcement as a function of tree density, distance from tree, tree species and age with the objective of providing quantitative

  20. Preliminary Calculation for Plasma Chamber Design of Pulsed Electron Source Based on Plasma

    International Nuclear Information System (INIS)

    Widdi Usada

    2009-01-01

    This paper described the characteristics of pulsed electron sources with anode-cathode distance of 5 cm, electrode diameter of 10 cm, driven by capacitor energy of 25 J. The preliminary results showed that if the system is operated with diode resistance is 1.6 Ω, plasma resistance is 0.14 Ω, and β is 0.94, the achieved of plasma voltage is 640 V, its current is 4.395 kA with its pulse width of 0.8 μsecond. According to breakdown voltage based on Paschen empirical formula, with this achieved voltage, this system could be operated for operation pressure of 1 torr. (author)

  1. A Preliminary Design of a Calibration Chamber for Evaluating the Stability of Unsaturated Soil Slope

    Science.gov (United States)

    Hsu, H.-H.

    2012-04-01

    The unsaturated soil slopes, which have ground water tables and are easily failure caused by heavy rainfalls, are widely distributed in the arid and semi-arid areas. For analyzing the stability of slope, in situ tests are the direct methods to obtain the test site characteristics. The cone penetration test (CPT) is a popular in situ test method. Some of the CPT empirical equations established from calibration chamber tests. The CPT performed in calibration chamber was commonly used clean quartz sand as testing material in the past. The silty sand is observed in many actual slopes. Because silty sand is relatively compressible than quartz sand, it is not suitable to apply the correlations between soil properties and CPT results built from quartz sand to silty sand. The experience on CPT calibration in silty sand has been limited. CPT calibration tests were mostly performed in dry or saturated soils. The condition around cone tip during penetration is assumed to be fully drained or fully undrained, yet it was observed to be partially drained for unsaturated soils. Because of the suction matrix has a great effect on the characteristics of unsaturated soils, they are much sensitive to the water content than saturated soils. The design of an unsaturated calibration chamber is in progress. The air pressure is supplied from the top plate and the pore water pressure is provided through the high air entry value ceramic disks located at the bottom plate of chamber cell. To boost and uniform distribute the unsaturated effect, four perforated burettes are installed onto the ceramic disks and stretch upwards to the midheight of specimen. This paper describes design concepts, illustrates this unsaturated calibration chamber, and presents the preliminary test results.

  2. Preliminary protein corona formation stabilizes gold nanoparticles and improves deposition efficiency

    Science.gov (United States)

    Luby, Alexandra O.; Breitner, Emily K.; Comfort, Kristen K.

    2016-08-01

    Due to their advantageous characteristics, gold nanoparticles (AuNPs) are being increasingly utilized in a vast array of biomedical applications. However, the efficacy of these procedures are highly dependent upon strong interactions between AuNPs and the surrounding environment. While the field of nanotechnology has grown exponentially, there is still much to be discovered with regards to the complex interactions between NPs and biological systems. One area of particular interest is the generation of a protein corona, which instantaneously forms when NPs encounter a protein-rich environment. Currently, the corona is viewed as an obstacle and has been identified as the cause for loss of application efficiency in physiological systems. To date, however, no study has explored if the protein corona could be designed and advantageously utilized to improve both NP behavior and application efficacy. Therefore, we sought to identify if the formation of a preliminary protein corona could modify both AuNP characteristics and association with the HaCaT cell model. In this study, a corona comprised solely of epidermal growth factor (EGF) was successfully formed around 10-nm AuNPs. These EGF-AuNPs demonstrated augmented particle stability, a modified corona composition, and increased deposition over stock AuNPs, while remaining biocompatible. Analysis of AuNP dosimetry was repeated under dynamic conditions, with lateral flow significantly disrupting deposition and the nano-cellular interface. Taken together, this study demonstrated the plausibility and potential of utilizing the protein corona as a means to influence NP behavior; however, fluid dynamics remains a major challenge to progressing NP dosimetry.

  3. Preliminary Calculations of Bypass Flow Distribution in a Multi-Block Air Test

    International Nuclear Information System (INIS)

    Kim, Min Hwan; Tak, Nam Il

    2011-01-01

    The development of a methodology for the bypass flow assessment in a prismatic VHTR (Very High Temperature Reactor) core has been conducted at KAERI. A preliminary estimation of variation of local bypass flow gap size between graphite blocks in the NHDD core were carried out. With the predicted gap sizes, their influence on the bypass flow distribution and the core hot spot was assessed. Due to the complexity of gap distributions, a system thermo-fluid analysis code is suggested as a tool for the core thermo-fluid analysis, the model and correlations of which should be validated. In order to generate data for validating the bypass flow analysis model, an experimental facility for a multi-block air test was constructed at Seoul National University (SNU). This study is focused on the preliminary evaluation of flow distribution in the test section to understand how the flow is distributed and to help the selection of experimental case. A commercial CFD code, ANSYS CFX is used for the analyses

  4. The Prognosis of Political Stability of the Russian Federation on the Basis of Calculation of the Index of National External Economic Stability

    Directory of Open Access Journals (Sweden)

    Владимир Геннадьевич Иванов

    2012-12-01

    Full Text Available The article contains the development of ideas presented in the previous issue of the bulletin. On the basis of the proposed by V.G. Ivanov methodology of calculation of the index of national external economic stability there has been prepared the short- mid-term prognosis of the level of stability of the Russian political regime. With a glance to the specificity of the development of the Russian Federation the methodology of calculation of the deflator of the referred index has been worked out as well.

  5. New method for calculations of nanostructure kinetic stability at high temperature

    Science.gov (United States)

    Fedorov, A. S.; Kuzubov, A. A.; Visotin, M. A.; Tomilin, F. N.

    2017-10-01

    A new universal method is developed for determination of nanostructure kinetic stability (KS) at high temperatures, when nanostructures can be destroyed by chemical bonds breaking due to atom thermal vibrations. The method is based on calculation of probability for any bond in the structure to stretch more than a limit value Lmax, when the bond breaks. Assuming the number of vibrations is very large and all of them are independent, using the central limit theorem, an expression for the probability of a given bond elongation up to Lmax is derived in order to determine the KS. It is shown that this expression leads to the effective Arrhenius formula, but unlike the standard transition state theory it allows one to find the contributions of different vibrations to a chemical bond cleavage. To determine the KS, only calculation of frequencies and eigenvectors of vibrational modes in the groundstate of the nanostructure is needed, while the transition states need not be found. The suggested method was tested on calculating KS of bonds in some alkanes, octene isomers and narrow graphene nanoribbons of different types and widths at the temperature T=1200 K. The probability of breaking of the C-C bond in the center of these hydrocarbons is found to be significantly higher than at the ends of the molecules. It is also shown that the KS of the octene isomers decreases when the double C˭C bond is moved to the end of the molecule, which agrees well with the experimental data. The KS of the narrowest graphene nanoribbons of different types varies by 1-2 orders of magnitude depending on the width and structure, while all of them are by several orders of magnitude less stable at high temperature than the hydrocarbons and benzene.

  6. Development of an X-ray installation for the study of secondary electrons: preliminary measurements and calculations

    International Nuclear Information System (INIS)

    Baguena, A.; Shaw, M.; Williart, A.; Baguena, A.; Garcia, G.

    2006-01-01

    We describe the calculations and preliminary measures made for the installation of a X-ray generator tube. This device is going to be used for the secondary electron production from photonic primary radiation of up to 125 keV. With this experimental system, we will study the energetic and space distribution of produced secondary electrons by obtaining its spectrum of energies and its angular distribution. This method of measurement is going to be applied in different targets of radiological, environmental and biological interest. Calculations in the present article include: theoretical yield of X-rays production of the designed equipment, necessary shielding for the radiological safety of the installation staff, and an estimated dose due to their use. Characteristics of the installation and the equipment are described with this purpose. (author)

  7. Development of an X-ray installation for the study of secondary electrons: preliminary measurements and calculations

    Energy Technology Data Exchange (ETDEWEB)

    Baguena, A.; Shaw, M.; Williart, A. [Universidad Nacional de Educacion a Distancia, Dpto. Fisica de los Materiales, Madrid (Spain); Baguena, A. [Consejo de Seguridad Nuclear, Madrid (Spain); Garcia, G. [Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Madrid (Spain)

    2006-07-01

    We describe the calculations and preliminary measures made for the installation of a X-ray generator tube. This device is going to be used for the secondary electron production from photonic primary radiation of up to 125 keV. With this experimental system, we will study the energetic and space distribution of produced secondary electrons by obtaining its spectrum of energies and its angular distribution. This method of measurement is going to be applied in different targets of radiological, environmental and biological interest. Calculations in the present article include: theoretical yield of X-rays production of the designed equipment, necessary shielding for the radiological safety of the installation staff, and an estimated dose due to their use. Characteristics of the installation and the equipment are described with this purpose. (author)

  8. Response to "Treatment compliance and effectiveness in complex PTSD patients with co-morbid personality disorder undergoing stabilizing cognitive behavioral group treatment: a preliminary study"

    NARCIS (Netherlands)

    de Jongh, A.; ten Broeke, E.

    2014-01-01

    Last November, the European Journal of Psychotraumatology published an interesting paper entitled "Treatment compliance and effectiveness in complex PTSD patients with co-morbid personality disorder undergoing stabilizing cognitive behavioral group treatment: a preliminary study". This article

  9. Using the charge-stabilization technique in the double ionization potential equation-of-motion calculations with dianion references.

    Science.gov (United States)

    Kuś, Tomasz; Krylov, Anna I

    2011-08-28

    The charge-stabilization method is applied to double ionization potential equation-of-motion (EOM-DIP) calculations to stabilize unstable dianion reference functions. The auto-ionizing character of the dianionic reference states spoils the numeric performance of EOM-DIP limiting applications of this method. We demonstrate that reliable excitation energies can be computed by EOM-DIP using a stabilized resonance wave function instead of the lowest energy solution corresponding to the neutral + free electron(s) state of the system. The details of charge-stabilization procedure are discussed and illustrated by examples. The choice of optimal stabilizing Coulomb potential, which is strong enough to stabilize the dianion reference, yet, minimally perturbs the target states of the neutral, is the crux of the approach. Two algorithms of choosing optimal parameters of the stabilization potential are presented. One is based on the orbital energies, and another--on the basis set dependence of the total Hartree-Fock energy of the reference. Our benchmark calculations of the singlet-triplet energy gaps in several diradicals show a remarkable improvement of the EOM-DIP accuracy in problematic cases. Overall, the excitation energies in diradicals computed using the stabilized EOM-DIP are within 0.2 eV from the reference EOM spin-flip values. © 2011 American Institute of Physics

  10. Thermal stability of chemically denatured green fluorescent protein (GFP) A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Attila; Malnasi-Csizmadia, Andras; Somogyi, Bela; Lorinczy, Denes

    2004-02-09

    Green fluorescent protein (GFP) is a light emitter in the bioluminescence reaction of the jellyfish Aequorea victoria. The protein consist of 238 amino acids and produces green fluorescent light ({lambda}{sub max}=508 nm), when irradiated with near ultraviolet light. The fluorescence is due to the presence of chromophore consisting of an imidazolone ring, formed by a post-translational modification of the tripeptide -Ser{sup 65}-Tyr{sup 66}-Gly{sup 67}-, which buried into {beta}-barrel. GFP is extremely compact and heat stable molecule. In this work, we present data for the effect of chemical denaturing agent on the thermal stability of GFP. When denaturing agent is applied, global thermal stability and the melting point of the molecule is decreases, that can be monitored with differential scanning calorimetry. The results indicate, that in 1-6 M range of GuHCl the melting temperature is decreasing continuously from 83 to 38 deg. C. Interesting finding, that the calculated calorimetric enthalpy decreases with GuHCl concentration up to 3 M (5.6-0.2 kJ mol{sup -1}), but at 4 M it jumps to 8.4 and at greater concentration it is falling down to 1.1 kJ mol{sup -1}. First phenomena, i.e. the decrease of melting point with increasing GuHCl concentration can be easily explained by the effect of the extended chemical denaturation, when less and less amount of heat required to diminish the remaining hydrogen bonds in {beta}-barrel. The surprising increase of calorimetric enthalpy at 4 M concentration of GuHCl could be the consequence of a dimerization or a formation of stable complex between GFP and denaturing agent as well as a precipitation at an extreme GuHCl concentration. We are planning further experiments to elucidate fluorescent consequence of these processes.

  11. Preliminary calculations on the cooling rate of the Renca batholit, Sierra de San Luis, Argentina

    International Nuclear Information System (INIS)

    Lopez de Luchi, M.G.; Ostera, H.A.; Linares, E; Rosello, E.A

    2001-01-01

    Cooling rates can be used to constrain the unroofing history of plutonic-metamorphic system. Geocronological cooling rates (Spear and Parrish, 1996) can be unravelled using age calculations on minerals that were open systems and subsequently passed through their closure temperatures (Dodson, 1973) during cooling. Several age determinations on different minerals are needed in order to accurately constrain the cooling path of a pluton (Hodges 1991, Spear and Parrish, 1996 and references therein). Isotopic open-system behaviour in minerals can be modelled as volume diffusion process (Hodges, 1991 and references therein), which depends on the cooling rate of the whole system. We present the first results on the calculation of the cooling rate of the Renca batholith on the basis of the combination of both thermometric calculations and available crystallization and cooling ages (au)

  12. A Preliminary Study on Calculation of Inter-Pebble Dancoff Factor in a Pebble Type Core

    International Nuclear Information System (INIS)

    Kim, Song Hyun; Kim, Hong Chul; Kim, Soon Young; Noh, Jae Man; Kim, Jong Kyung

    2009-01-01

    The Dancoff factor is an entering probability of the neutron escaped from specific fuel kernel to another one without the interaction with moderators. Currently, Dancoff factors are mainly evaluated from stochastic methods, hence a research on analytical method is considerably insufficient in this field. In order to analytically evaluate Dancoff factor considering double-heterogeneous effect, inter-pebble and intra-pebble Dancoff factors should be calculated, respectively. Intra-pebble Dancoff factor related with the fuel kernels in one pebble was analyzed in past study. For the evaluation of inter-pebble Dancoff factor, fuel region to region Dancoff factor (FRDF) was defined and the method to calculate the FRDF is developed in this study. The result is compared with the calculation result of the MCNP5 code

  13. Preliminary calculations of release rates from spent fuel in a tuff repository

    International Nuclear Information System (INIS)

    Apted, M.J.; O'Connell, W.J.; Lee, K.H.; MacIntyre, A.T.; Ueng, T.S.; Pigford, T.H.; Lee, W.W.L.

    1991-01-01

    Time-dependent release rates of Tc-99, I-129, Cs-135, and Np-237 have been calculated for wet-drip and moist-continuous release modes from the engineered barrier system of a potential nuclear waste repository in unsaturated tuff, representative of a possible repository at Yucca Mountain in southern Nevada. We describe the modes of water contact and of release of dissolved radionuclides to the surrounding intact rock, and the corresponding calculational models. We list the parameter values adopted, and then present numerical results, conclusions, and recommendations. 21 refs., 5 figs., 2 tabs

  14. Preliminary Calculation of the Indicators of Sustainable Development for National Radioactive Waste Management Programs

    International Nuclear Information System (INIS)

    Cheong, Jae Hak; Park, Won Jae

    2003-01-01

    As a follow up to the Agenda 21's policy statement for safe management of radioactive waste adopted at Rio Conference held in 1992, the UN invited the IAEA to develop and implement indicators of sustainable development for the management of radioactive waste. The IAEA finalized the indicators in 2002, and is planning to calculate the member states' values of indicators in connection with operation of its Net-Enabled Waste Management Database system. In this paper, the basis for introducing the indicators into the radioactive waste management was analyzed, and calculation methodology and standard assessment procedure were simply depicted. In addition, a series of innate limitations in calculation and comparison of the indicators was analyzed. According to the proposed standard procedure, the indicators for a few major countries including Korea were calculated and compared, by use of each country's radioactive waste management framework and its practices. In addition, a series of measures increasing the values of the indicators was derived so as to enhance the sustainability of domestic radioactive waste management program.

  15. A flexible Monte Carlo tool for patient or phantom specific calculations: comparison with preliminary validation measurements

    Science.gov (United States)

    Davidson, S.; Cui, J.; Followill, D.; Ibbott, G.; Deasy, J.

    2008-02-01

    The Dose Planning Method (DPM) is one of several 'fast' Monte Carlo (MC) computer codes designed to produce an accurate dose calculation for advanced clinical applications. We have developed a flexible machine modeling process and validation tests for open-field and IMRT calculations. To complement the DPM code, a practical and versatile source model has been developed, whose parameters are derived from a standard set of planning system commissioning measurements. The primary photon spectrum and the spectrum resulting from the flattening filter are modeled by a Fatigue function, cut-off by a multiplying Fermi function, which effectively regularizes the difficult energy spectrum determination process. Commonly-used functions are applied to represent the off-axis softening, increasing primary fluence with increasing angle ('the horn effect'), and electron contamination. The patient dependent aspect of the MC dose calculation utilizes the multi-leaf collimator (MLC) leaf sequence file exported from the treatment planning system DICOM output, coupled with the source model, to derive the particle transport. This model has been commissioned for Varian 2100C 6 MV and 18 MV photon beams using percent depth dose, dose profiles, and output factors. A 3-D conformal plan and an IMRT plan delivered to an anthropomorphic thorax phantom were used to benchmark the model. The calculated results were compared to Pinnacle v7.6c results and measurements made using radiochromic film and thermoluminescent detectors (TLD).

  16. Poster - 08: Preliminary Investigation into Collapsed-Cone based Dose Calculations for COMS Eye Plaques

    International Nuclear Information System (INIS)

    Morrison, Hali; Menon, Geetha; Sloboda, Ron

    2016-01-01

    Purpose: To investigate the accuracy of model-based dose calculations using a collapsed-cone algorithm for COMS eye plaques loaded with I-125 seeds. Methods: The Nucletron SelectSeed 130.002 I-125 seed and the 12 mm COMS eye plaque were incorporated into a research version of the Oncentra® Brachy v4.5 treatment planning system which uses the Advanced Collapsed-cone Engine (ACE) algorithm. Comparisons of TG-43 and high-accuracy ACE doses were performed for a single seed in a 30×30×30 cm 3 water box, as well as with one seed in the central slot of the 12 mm COMS eye plaque. The doses along the plaque central axis (CAX) were used to calculate the carrier correction factor, T(r), and were compared to tabulated and MCNP6 simulated doses for both the SelectSeed and IsoAid IAI-125A seeds. Results: The ACE calculated dose for the single seed in water was on average within 0.62 ± 2.2% of the TG-43 dose, with the largest differences occurring near the end-welds. The ratio of ACE to TG-43 calculated doses along the CAX (T(r)) of the 12 mm COMS plaque for the SelectSeed was on average within 3.0% of previously tabulated data, and within 2.9% of the MCNP6 simulated values. The IsoAid and SelectSeed T(r) values agreed within 0.3%. Conclusions: Initial comparisons show good agreement between ACE and MC doses for a single seed in a 12 mm COMS eye plaque; more complicated scenarios are being investigated to determine the accuracy of this calculation method.

  17. Poster - 08: Preliminary Investigation into Collapsed-Cone based Dose Calculations for COMS Eye Plaques

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Hali; Menon, Geetha; Sloboda, Ron [Cross Cancer Institute, Edmonton, AB, and University of Alberta, Edmonton, AB, Cross Cancer Institute, Edmonton, AB, and University of Alberta, Edmonton, AB, Cross Cancer Institute, Edmonton, AB, and University of Alberta, Edmonton, AB (Canada)

    2016-08-15

    Purpose: To investigate the accuracy of model-based dose calculations using a collapsed-cone algorithm for COMS eye plaques loaded with I-125 seeds. Methods: The Nucletron SelectSeed 130.002 I-125 seed and the 12 mm COMS eye plaque were incorporated into a research version of the Oncentra® Brachy v4.5 treatment planning system which uses the Advanced Collapsed-cone Engine (ACE) algorithm. Comparisons of TG-43 and high-accuracy ACE doses were performed for a single seed in a 30×30×30 cm{sup 3} water box, as well as with one seed in the central slot of the 12 mm COMS eye plaque. The doses along the plaque central axis (CAX) were used to calculate the carrier correction factor, T(r), and were compared to tabulated and MCNP6 simulated doses for both the SelectSeed and IsoAid IAI-125A seeds. Results: The ACE calculated dose for the single seed in water was on average within 0.62 ± 2.2% of the TG-43 dose, with the largest differences occurring near the end-welds. The ratio of ACE to TG-43 calculated doses along the CAX (T(r)) of the 12 mm COMS plaque for the SelectSeed was on average within 3.0% of previously tabulated data, and within 2.9% of the MCNP6 simulated values. The IsoAid and SelectSeed T(r) values agreed within 0.3%. Conclusions: Initial comparisons show good agreement between ACE and MC doses for a single seed in a 12 mm COMS eye plaque; more complicated scenarios are being investigated to determine the accuracy of this calculation method.

  18. Aeroelastic and stability behaviour of the WTS 3 Maglarp wind turbine. Calculations and comparisons with tests

    Energy Technology Data Exchange (ETDEWEB)

    Soederberg, M.

    1990-01-01

    The GAROS system for general analysis of rotating aeroelastic structures is used to analyse the behaviour of the WTS 3 Maglarp wind turbine, situated in Maglarp, Sweden. The GAROS method is based on a branch mode technique and modal reduction. Stability analyses of the total tower-rotor system as well as numerical time integration analyses are performed within the GAROS system. The FE-model made by Anders Henoch, AIMS, for FFA is used as a base for this investigation. Some modifications concerning center of gravity of the rotor and teeter bearing/hinge have been made in the finite element model. In this report simulated values of loads in the blades are compaed to measured data. The unstable yaw behaviour of the WTS 3 was also found in the behaviour of the model. The amount of yaw-angle rotation in the model was also found to be according to measured values when induced velocities were accounted for in the aerodynamic force calculations. The analyses in general show good agreement between simulated and measured values. This paper was presented at the European Wind Energy Conference in Glasgow, 10-13 July, 1989.

  19. Diffusion quantum Monte Carlo and density functional calculations of the structural stability of bilayer arsenene

    Science.gov (United States)

    Kadioglu, Yelda; Santana, Juan A.; Özaydin, H. Duygu; Ersan, Fatih; Aktürk, O. Üzengi; Aktürk, Ethem; Reboredo, Fernando A.

    2018-06-01

    We have studied the structural stability of monolayer and bilayer arsenene (As) in the buckled (b) and washboard (w) phases with diffusion quantum Monte Carlo (DMC) and density functional theory (DFT) calculations. DMC yields cohesive energies of 2.826(2) eV/atom for monolayer b-As and 2.792(3) eV/atom for w-As. In the case of bilayer As, DMC and DFT predict that AA-stacking is the more stable form of b-As, while AB is the most stable form of w-As. The DMC layer-layer binding energies for b-As-AA and w-As-AB are 30(1) and 53(1) meV/atom, respectively. The interlayer separations were estimated with DMC at 3.521(1) Å for b-As-AA and 3.145(1) Å for w-As-AB. A comparison of DMC and DFT results shows that the van der Waals density functional method yields energetic properties of arsenene close to DMC, while the DFT + D3 method closely reproduced the geometric properties from DMC. The electronic properties of monolayer and bilayer arsenene were explored with various DFT methods. The bandgap values vary significantly with the DFT method, but the results are generally qualitatively consistent. We expect the present work to be useful for future experiments attempting to prepare multilayer arsenene and for further development of DFT methods for weakly bonded systems.

  20. The Effects of Battalion Staff Stabilization on Individual and Unit Performance: A Preliminary Investigation

    National Research Council Canada - National Science Library

    Ardison, Sharon

    2001-01-01

    ... (six of the seven units). Although improvements in leadership skills and abilities were associated with longer command team tenure, the results are those of a preliminary investigation and not intended for generalization to the Army-at-large.

  1. Structural stability and elastic properties of L12 Co3(Ga,W) precipitate from first-principle calculations

    International Nuclear Information System (INIS)

    Yao Qiang; Zhu Yuhong; Wang Yan

    2011-01-01

    Ultrasoft pseudopotential within a generalized gradient approximation was employed to study the structural stability, electronic structure, and elastic properties of ternary Co 3 (Ga,W) precipitate. The Young's and shear moduli of the polycrystals containing the Co 3 (Ga,W) precipitate were calculated using the Voigt-Reuss-Hill averaging scheme. Results show that the stable ternary Co 3 (Ga,W) compound has the L1 2 structure, and is ductile in nature. The structural stability of the Co 3 (Ga,W) compound is discussed together with the calculated electronic structure.

  2. Preliminary results on food consumption rates for off-site dose calculation of nuclear power plants

    International Nuclear Information System (INIS)

    Lee, Gab Bock; Chung, Yang Geun; Bang, Sun Young; Kang, Duk Won

    2005-01-01

    The Internal dose by food consumption mostly account for radiological dose of public around nuclear power plants(NPP). But, food consumption rate applied to off-site dose calculation in Korea which is the result of field investigation around Kori NPP by the KAERI in 1988. is not reflected of the latest dietary characteristics. The Ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. To update the food consumption rates of the maximum individual, the analysis of the national food investigation results and field surveys around nuclear power plant sites have been carried out

  3. Preliminary calculation with code CONTEMPT-LT for spray cooling tests with JAERI model containment vessel

    International Nuclear Information System (INIS)

    Tanaka, Mitsugu

    1978-01-01

    LWR plants have a containment spray system to reduce the escape of radioactive material to the environment in a loss-of-coolant accident (LOCA) by washing out fission products, especially radioiodine, and condensing the steam to lower the pressure. For carrying out the containment spray tests, pressure and temperature behaviour of the JAERI Model Containment Vessel in spray cooling has been calculated with computer program CONTEMPT-LT. The following could be studied quantitatively: (1) pressure and temperature raise rates for steam addition rate and (2) pressure fall rate for spray flow rate and spray heat transfer efficiency. (auth.)

  4. Integrated optimization on aerodynamics-structure coupling and flight stability of a large airplane in preliminary design

    Directory of Open Access Journals (Sweden)

    Xiaozhe WANG

    2018-06-01

    Full Text Available The preliminary phase is significant during the whole design process of a large airplane because of its enormous potential in enhancing the overall performance. However, classical sequential designs can hardly adapt to modern airplanes, due to their repeated iterations, long periods, and massive computational burdens. Multidisciplinary analysis and optimization demonstrates the capability to tackle such complex design issues. In this paper, an integrated optimization method for the preliminary design of a large airplane is proposed, accounting for aerodynamics, structure, and stability. Aeroelastic responses are computed by a rapid three-dimensional flight load analysis method combining the high-order panel method and the structural elasticity correction. The flow field is determined by the viscous/inviscid iteration method, and the cruise stability is evaluated by the linear small-disturbance theory. Parametric optimization is carried out using genetic algorithm to seek the minimal weight of a simplified plate-beam wing structure in the cruise trim condition subject to aeroelastic, aerodynamic, and stability constraints, and the optimal wing geometry shape, front/rear spar positions, and structural sizes are obtained simultaneously. To reduce the computational burden of the static aeroelasticity analysis in the optimization process, the Kriging method is employed to predict aerodynamic influence coefficient matrices of different aerodynamic shapes. The multidisciplinary analyses guarantee computational accuracy and efficiency, and the integrated optimization considers the coupling effect sufficiently between different disciplines to improve the overall performance, avoiding the limitations of sequential approaches utilized currently. Keywords: Aeroelasticity, Integrated optimization, Multidisciplinary analysis, Large airplane, Preliminary design

  5. Preliminary Criticality Calculation on Conceptual Deep Borehole Disposal System for Trans-metal Waste during Operational Phase

    International Nuclear Information System (INIS)

    Kim, In Young; Choi, Heui Joo; Cho, Dong Geun

    2013-01-01

    The primary function of any repository is to prevent spreading of dangerous materials into surrounding environment. In the case of high-level radioactive waste repository, radioactive material must be isolated and retarded during sufficient decay time to minimize radiation hazard to human and surrounding environment. Sub-criticality of disposal canister and whole disposal system is minimum requisite to prevent multiplication of radiation hazard. In this study, criticality of disposal canister and DBD system for trans-metal waste is calculated to check compliance of sub-criticality. Preliminary calculation on criticality of conceptual deep borehole disposal system and its canister for trans-metal waste during operational phase is conducted in this study. Calculated criticalities at every temperature are under sub-criticalities and criticalities of canister and DBD system considering temperature are expected to become 0.34932 and 0.37618 approximately. There are obvious limitations in this study. To obtain reliable data, exact elementary composition of each component, system component temperature must be specified and applied, and then proper cross section according to each component temperature must be adopted. However, many assumptions, for example simplified elementary concentration and isothermal component temperature, are adopted in this study. Improvement of these data must be conducted in the future work to progress reliability. And, post closure criticality analyses including geo, thermal, hydro, mechanical, chemical mechanism, especially fissile material re-deposition by precipitation and sorption, must be considered to ascertain criticality safety of DBD system as a future work

  6. Preliminary shielding calculation for the system of CyberKnife robotic radiosurgery

    International Nuclear Information System (INIS)

    Toreti, Dalila; Xavier, Clarice; Moura, Fabio

    2011-01-01

    The CyberKnife robotic system uses a manipulator with six grade of freedom for positioning a 6 MV Linac accelerator for treatment of lesions. This paper presents calculations for a standard room, with 200 cm of thickness walls primary, build for a CyberKnife system, and calculations for a room originally designed for a Linac conventional (with gantry), with secondary barriers of 107 cm thickness. After the realization of shielding for both rooms, the results shown that walls of standard room with 200 cm thickness are adequate for the secondary shield, and for a room with a conventional Linac, from all six evaluated points, two would require additional shielding of nine cm and four cm of concrete with 2.4 g/cubic cm. This shows that the CyberKnife system can be installed in a originally designed room for a conventional Linac with neither restrict nor any shielding, since no incidence of beams on the secondary barriers is existent

  7. Preliminary reactor physics calculations for Exxon LWR fuel testing in the power burst facility

    International Nuclear Information System (INIS)

    Olson, W.O.; Nigg, D.W.

    1981-05-01

    The PFB reactor is being considered as an irradiation facility to test LWR fuel rods for Exxon Nuclear Company. Requested test conditions are 18 kW/ft axial peak steady state power in 2.5% initial enrichment, 20,000 MWd/Tu exposed rods. Multigroup transport theory calculations (S/sub n/ and Monte Carlo) showed that this was unattainable in the standard PBF test loop. Thus, a flux multiplier was developed in the form of a Zr-2-clad 0.15-inch thick cylindrical shell of 35% enriched, 88% T.D. UO 2 replacing the flow divider, surrounding the rod within the in-pile tube in PFB. With this flux multiplier installed and assuming an average water density of 0.86 g/cm 3 within the test loop, a Figure of Merit (FOM) for a single-rod test assembly of 0.86 kW/ft-MW +- 5% (at 95% confidence level) was calculated. This FOM is the axial peak linear test rod power per megawatt of reactor power. A reactor power of about 21 megawatts will therefore be required to supply the requested linear test rod axial peak heating rate of 18 kW/ft

  8. A novel upwind stabilized discontinuous finite element angular framework for deterministic dose calculations in magnetic fields.

    Science.gov (United States)

    Yang, R; Zelyak, O; Fallone, B G; St-Aubin, J

    2018-01-30

    Angular discretization impacts nearly every aspect of a deterministic solution to the linear Boltzmann transport equation, especially in the presence of magnetic fields, as modeled by a streaming operator in angle. In this work a novel stabilization treatment of the magnetic field term is developed for an angular finite element discretization on the unit sphere, specifically involving piecewise partitioning of path integrals along curved element edges into uninterrupted segments of incoming and outgoing flux, with outgoing components updated iteratively. Correct order-of-accuracy for this angular framework is verified using the method of manufactured solutions for linear, quadratic, and cubic basis functions in angle. Higher order basis functions were found to reduce the error especially in strong magnetic fields and low density media. We combine an angular finite element mesh respecting octant boundaries on the unit sphere to spatial Cartesian voxel elements to guarantee an unambiguous transport sweep ordering in space. Accuracy for a dosimetrically challenging scenario involving bone and air in the presence of a 1.5 T parallel magnetic field is validated against the Monte Carlo package GEANT4. Accuracy and relative computational efficiency were investigated for various angular discretization parameters. 32 angular elements with quadratic basis functions yielded a reasonable compromise, with gamma passing rates of 99.96% (96.22%) for a 2%/2 mm (1%/1 mm) criterion. A rotational transformation of the spatial calculation geometry is performed to orient an arbitrary magnetic field vector to be along the z-axis, a requirement for a constant azimuthal angular sweep ordering. Working on the unit sphere, we apply the same rotational transformation to the angular domain to align its octants with the rotated Cartesian mesh. Simulating an oblique 1.5 T magnetic field against GEANT4 yielded gamma passing rates of 99.42% (95.45%) for a 2%/2 mm (1%/1 mm) criterion.

  9. MHD stability of JET high performance discharges. Comparison of MHD calculations with experimental observations

    International Nuclear Information System (INIS)

    Huysmans, G.

    1998-03-01

    One of the aims of the JET, the Joint European Torus, project is to optimise the maximum fusion performance as measured by the neutron rate. At present, two different scenarios are developed at JET to achieve the high performance the so-called Hot-Ion H-mode scenario and the more recent development of the Optimised Shear scenario. Both scenarios have reached similar values of the neutron rate in Deuterium plasmas, up to 5 10 17 neutrons/second. Both scenarios are characterised by a transport barrier, i.e., a region in the plasma where the confinement is improved. The Hot-Ion H-mode has a transport barrier at the plasma boundary just inside the separatrix, an Optimised Shear plasma exhibits a transport barrier at about mid radius. Associated with the improved confinement of the transport barriers are locally large pressure gradients. It is these pressure gradients which, either directly or indirectly, can drive MHD instabilities. The instabilities limit the maximum performance. In the optimised shear scenario a global MHD instability leads to a disruptive end of the discharge. In the Hot-Ion H-mode plasmas, so-called Outer Modes can occur which are localised at the plasma boundary and lead to a saturation of the plasma performance. In this paper, two examples of the MHD instabilities are discussed and identified by comparing the experimentally observed modes with theoretical calculations from the ideal MHD code MISHKA-1. Also, the MHD stability boundaries of the two scenarios are presented. Section 3 contains a discussion of the mode observed just before the disruption

  10. A novel upwind stabilized discontinuous finite element angular framework for deterministic dose calculations in magnetic fields

    Science.gov (United States)

    Yang, R.; Zelyak, O.; Fallone, B. G.; St-Aubin, J.

    2018-02-01

    Angular discretization impacts nearly every aspect of a deterministic solution to the linear Boltzmann transport equation, especially in the presence of magnetic fields, as modeled by a streaming operator in angle. In this work a novel stabilization treatment of the magnetic field term is developed for an angular finite element discretization on the unit sphere, specifically involving piecewise partitioning of path integrals along curved element edges into uninterrupted segments of incoming and outgoing flux, with outgoing components updated iteratively. Correct order-of-accuracy for this angular framework is verified using the method of manufactured solutions for linear, quadratic, and cubic basis functions in angle. Higher order basis functions were found to reduce the error especially in strong magnetic fields and low density media. We combine an angular finite element mesh respecting octant boundaries on the unit sphere to spatial Cartesian voxel elements to guarantee an unambiguous transport sweep ordering in space. Accuracy for a dosimetrically challenging scenario involving bone and air in the presence of a 1.5 T parallel magnetic field is validated against the Monte Carlo package GEANT4. Accuracy and relative computational efficiency were investigated for various angular discretization parameters. 32 angular elements with quadratic basis functions yielded a reasonable compromise, with gamma passing rates of 99.96% (96.22%) for a 2%/2 mm (1%/1 mm) criterion. A rotational transformation of the spatial calculation geometry is performed to orient an arbitrary magnetic field vector to be along the z-axis, a requirement for a constant azimuthal angular sweep ordering. Working on the unit sphere, we apply the same rotational transformation to the angular domain to align its octants with the rotated Cartesian mesh. Simulating an oblique 1.5 T magnetic field against GEANT4 yielded gamma passing rates of 99.42% (95.45%) for a 2%/2 mm (1%/1 mm) criterion.

  11. Preliminary Calculation of the EROI for the Production of Gas in Russia

    Directory of Open Access Journals (Sweden)

    Roman Nogovitsyn

    2014-09-01

    Full Text Available Russia is one of the world’s largest producers of energy resources. Production of energy resources in Russia is profitable, both economically and in terms of the energy produced (as measured by EROI. At the present time, Russian oil and gas companies have a policy of energy saving, and data on energy consumption is given in annual reports. Based on these data, we can make the EROI calculation. In 2013, the EROI for the production, transportation and processing of gas for Open joint stock company (OJSC “Gazprom” was 79:1; for OJSC “NOVATEK”, 76:1; for OJSC “Yakutsk Fuel and Energy Company (YATEC”, only for production, 116:1. Currently, the situation in the oil and gas industry has come to a point when there is a need for the introduction of an energy audit.

  12. Comparison of the calculations of the stability properties of a specific stellarator equilibrium with different MHD stability codes

    International Nuclear Information System (INIS)

    Nakamura, Y.; Matsumoto, T.; Wakatani, M.; Ichiguchi, K.; Garcia, L.; Carreras, B.A.

    1995-04-01

    A particular configuration of the LHD stellarator with an unusually flat pressure profile has been chosen to be a test case for comparison of the MHD stability property predictions of different three-dimensional and averaged codes for the purpose of code comparison and validation. In particular, two relatively localized instabilities, the fastest growing modes with toroidal mode number n = 2 and n = 3 were studied using several different codes, with the good agreement that has been found providing justification for the use of any of them for equilibria of the type considered

  13. MHD stability calculations of high-β quasi-axisymmetric stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Pomphrey, N.; Redi, M.H.; Kessel, C.; Monticello, D.A.; Reiman, A.; Hughes, M.; Cooper, W.A.; Nuehrenberg, C.

    1999-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size. (author)

  14. MHD Stability Calculations of High-Beta Quasi-Axisymmetric Stellarators

    International Nuclear Information System (INIS)

    Kessel, C.; Fu, G.Y.; Ku, L.P.; Redi, M.H.; Pomphrey, N.

    1999-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size

  15. MHD stability calculations of high-β quasi-axisymmetric stellarators

    International Nuclear Information System (INIS)

    Fu, G.Y.; Ku, L.P.; Pomphrey, N.; Redi, M.; Kessel, C.; Monticello, D.; Reiman, A.; Hughes, M.; Cooper, W.A.; Nuehrenberg, C.

    2001-01-01

    The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size. (author)

  16. ELMs and constraints on the H-mode pedestal: peeling-ballooning stability calculation and comparison with experiment

    International Nuclear Information System (INIS)

    Snyder, P.B.; Ferron, J.R.; Wilson, H.R.

    2004-01-01

    We review and test the peeling-ballooning model for edge localized modes (ELMs) and pedestal constraints, a model based upon theoretical analysis of magnetohydrodynamic (MHD) instabilities that can limit the pedestal height and drive ELMs. A highly efficient MHD stability code, ELITE, is used to calculate quantitative stability constraints on the pedestal, including constraints on the pedestal height. Because of the impact of collisionality on the bootstrap current, these pedestal constraints are dependent on the density and temperature separately, rather than simply on the pressure. ELITE stability calculations are directly compared with experimental data for a series of plasmas in which the density is varied and ELM characteristics change. In addition, a technique is developed whereby peeling-ballooning pedestal constraints are calculated as a function of key equilibrium parameters via ELITE calculations using series of model equilibria. This technique is used to successfully compare the expected pedestal height as a function of density, triangularity and plasma current with experimental data. Furthermore, the technique can be applied for parameter ranges beyond the purview of present experiments, and we present a brief projection of peeling-ballooning pedestal constraints for burning plasma tokamak designs. (author)

  17. Design aspects of the Alpha Repository. I. Preliminary results of facility layout, room stability, and equipment selection efforts. Summary progress report RSI-0024

    International Nuclear Information System (INIS)

    Gnirk, P.F.; Grams, W.H.; Zeller, T.J.; Ellis, D.B.; Pariseau, W.G.; Fossum, A.F.; Ratigan, J.L.; Hansen, F.D.

    1975-01-01

    Results of preliminary analysis of the stability of mines in salt formations underlying Eddy and Lea Counties in New Mexico are presented. Methods and equipment for drilling canister emplacement holes in these formations were evaluated along with methods for excavating storage areas and transport of the excavated salt. Progress during the period is reported in chapters on geological and rock properties at the repository site, preliminary mine layout, basic requirements for repository usage, excavation geometries, drill selection, excavation systems, and safety requirements

  18. Guide for calculating the stability of mine berms and spoil bank slopes in the Maritsa-Iztok coal basin

    Energy Technology Data Exchange (ETDEWEB)

    Georgiev, G; Todorova, M; Doneva, V; Novachkov, N; Nedyalkov, N; Mitev, A; Rachev, R

    1984-08-01

    Major landslides are described which occurred in the basin between 1963 and 1970 during overburden removal and formation of spoil banks. Guidelines for the prevention of landslides were developed on the basis of large scale studies of geomechanics, geostatic calculations and geodetic observations of slope behavior; no further landslide has occurred since 1970. Cohesion coefficients, angle of internal friction and shear properties were determined for each material occurring in the clayey and sandy overburden and for the coal (ash content 15-55%). Slope stability of working benches and spoil banks at the Troyanovo mines was then calculated. 8 references.

  19. Preliminary assessment of channel stability and bed-material transport along Hunter Creek, southwestern Oregon

    Science.gov (United States)

    Jones, Krista L.; Wallick, J. Rose; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Risley, John C.

    2011-01-01

    This preliminary assessment of (1) bed-material transport in the Hunter Creek basin, (2) historical changes in channel condition, and (3) supplementary data needed to inform permitting decisions regarding instream gravel extraction revealed the following: Along the lower 12.4 km (kilometers) of Hunter Creek from its confluence with the Little South Fork Hunter Creek to its mouth, the river has confined and unconfined segments and is predominately alluvial in its lowermost 11 km. This 12.4-km stretch of river can be divided into two geomorphically distinct study reaches based primarily on valley physiography. In the Upper Study Reach (river kilometer [RKM] 12.4-6), the active channel comprises a mixed bed of bedrock, boulders, and smaller grains. The stream is confined in the upper 1.4 km of the reach by a bedrock canyon and in the lower 2.4 km by its valley. In the Lower Study Reach (RKM 6-0), where the area of gravel bars historically was largest, the stream flows over bed material that is predominately alluvial sediments. The channel alternates between confined and unconfined segments. The primary human activities that likely have affected bed-material transport and the extent and area of gravel bars are (1) historical and ongoing aggregate extraction from gravel bars in the study area and (2) timber harvest and associated road construction throughout the basin. These anthropogenic activities likely have varying effects on sediment transport and deposition throughout the study area and over time. Although assessing the relative effects of these anthropogenic activities on sediment dynamics would be challenging, the Hunter Creek basin may serve as a case study for such an assessment because it is mostly free of other alterations to hydrologic and geomorphic processes such as flow regulation, dredging, and other navigation improvements that are common in many Oregon coastal basins. Several datasets are available that may support a more detailed physical assessment

  20. The effect of hydroxyl groups on the stability and thermodynamic properties of polyhydroxylated xanthones as calculated by density functional theory

    International Nuclear Information System (INIS)

    Qu, Ruijuan; Liu, Hongxia; Zhang, Qi; Flamm, Alison; Yang, Xi; Wang, Zunyao

    2012-01-01

    Highlights: ► The strength of the hydrogen bonds existed in PHOXTHs is ascertained. ► Good linear relations exist between the thermodynamic properties and N PHOS . ► The relative stability order of PHOXTH congeners is theoretically proposed. ► There is a good relation between C p,m and the temperature. - Abstract: There are three types of intramolecular hydrogen bonds with bond energy about 52 kJ mol −1 , 12 kJ mol −1 , 20 kJ mol −1 , respectively in PHOXTHs which were determined by computation on B3LYP/6-311G** level. The internal rotational potentials of the hydroxy group of 1-MHOXTH and 4′-MHOXTH are evaluated, and the influences of the spatial orientation of the hydroxy groups on the intramolecular hydrogen bonds and molecular stability are illustrated. The standard enthalpy of formation (Δ f H θ ) and standard Gibbs energy of formation (Δ f G θ ) for the most stable conformation of 135 PHOXTHs are calculated by the combination of Gaussian 03 and isodesmic reactions and the theoretical order of relative stability is proposed according to the relative magnitude of calculated Δ f G θ values. In addition, the values of molar heat capacities at constant pressure (C p,m ) from 200 to 1000 K for PHOXTH congeners are calculated.

  1. CAN THE STABILITY OF PROTEIN MUTANTS BE PREDICTED BY FREE-ENERGY CALCULATIONS

    NARCIS (Netherlands)

    YUNYU, S; MARK, AE; WANG, CX; HUANG, FH; BERENDSEN, HJC; VANGUNSTEREN, WF

    The use of free energy simulation techniques in the study of protein stability is critically evaluated. Results from two simulations of the thermostability mutation Asn218 to Ser218 in Subtilisin are presented. It is shown that components of the free energy change can be highly sensitive to the

  2. FINANCIAL STABILITY CROSS-REFERENCE BASED ON CALCULATION OF ABSOLUTE INDICATORS

    Directory of Open Access Journals (Sweden)

    Neli MUNTEAN

    2017-04-01

    Full Text Available The lack of applied methods in the national practice that would allow the realization of a complex analysis of financial stability in the corporate sector is one of the primary problems outlined in the process of organizing the fair and efficient management system of numerous factors that determine the financial performance in this sector. Under these circumstances, the need for a comprehensive analysis of financial stability in the corporate sector significantly increases, being an integrated part of the entity's financial situation analysis. The purpose and objectives of the article consist in the generalization of theoretical principles, financial stability analysis instruments and techniques in terms of absolute indicators adaptation to the norms and requirements of International Financial Reporting Standards, and in the comparative analysis of several methods that can be used to measure financial stability in the corporate sector. Thus, the following study, developed as a fusion of existing knowledge and authors own research, aims to provide a basis for reflection and discussion with theorists, practitioners and analysts within the financial field.

  3. Site preference and phase stability of Ti doping Ni–Mn–Ga shape memory alloys from first-principles calculations

    International Nuclear Information System (INIS)

    Gao, Zhiyong; Chen, Baishu; Meng, Xianglong; Cai, Wei

    2013-01-01

    Highlights: •Site preference and phase stability of NiMnGaTi are studied by first-principles. •The Ti atoms prefer to occupy the Ga sites in the Ni 2 MnGa austenitic phase. •The phase stability becomes worse when Ga is replaced by Ti. •The phase stability is discussed based on the densities of states. -- Abstract: The effects of Ti content on martensitic transformation and phase stability of Ni 50 Mn 25 Ga 25−x Ti x shape memory alloys were investigated from first-principles calculations based on density functional theory. The formation energy results indicate that the added Ti preferentially occupies the Ga sites in Ni 2 MnGa alloy due to the lowest formation energy. The total energy difference between austenite and martensite increases with Ti alloying, being relevant to the experimentally reported changes in martensitic transformation temperature. The phase stability of Ni 50 Mn 25 Ga 25−x Ti x austenite decreases with increasing Ti content, which results from the reduced Ni 3d–Mn 3d hybridization when Ga is replaced by Ti

  4. Softver za proračun uzdužne statičke stabilnosti i upravljivosti aviona za osnovnu obuku pilota / Software for calculation of an axial static stability and management of airplanes for basic pilot training

    Directory of Open Access Journals (Sweden)

    Dalibor Petrović

    2006-07-01

    Full Text Available U ovom radu opisan je softver za proračun uzdužne statičke stabilnosti i upravljivosti aviona za osnovnu obuku pilota. Softver je urađen sa numerom da konstruktorima omogući brzo i lako dobijanje potrebnih rezultata vezanih za stabilnost i upravljivost kod preliminarnih proračuna vezanih za ovu vrstu aviona. Program je urađen na osnovu analize velikog broja aviona iz ove klase, a njegova tačnost je testirana na avionu "Lasta". Rezultati koji su dobijeni ovim softverom bili su više od zadovoljavajućih, s obzirom na to da se radi o programu koji bi se koristio za preliminarni proračun. / This document introduced software for calculation of an axial static stability and management of airplanes for basic pilot training. The purpose of this software is to provide a quicker and an easier way of getting results regarding preliminary calculation of stability and management for these types of airplanes. The program is based upon analysis of data gathered from a large number of tested airplanes of this class. The accuracy of the program has been tested on the airplane type 'Lasta' and results were more than satisfying, especially regarding the fact that the program is meant to be used for preliminary calculation.

  5. Effects of circumferential ankle pressure on ankle proprioception, stiffness, and postural stability: a preliminary investigation.

    Science.gov (United States)

    You, Sung H; Granata, Kevin P; Bunker, Linda K

    2004-08-01

    Cross-sectional repeated-measures design. Determine the effects of circumferential ankle pressure (CAP) intervention on proprioceptive acuity, ankle stiffness, and postural stability. The application of CAP using braces, taping, and adaptive shoes or military boots is widely used to address chronic ankle instability (CAI). An underlying assumption is that the CAP intervention might improve ankle stability through increased proprioceptive acuity and stiffness in the ankle. METHOD AND MEASURES: A convenience sample of 10 subjects was recruited from the local university community and categorized according to proprioceptive acuity (high, low) and ankle stability (normal, CAI). Proprioceptive acuity was measured when blindfolded subjects were asked to accurately reproduce a self-selected target ankle position before and after the application of CAP. Proprioceptive acuity was determined in 5 different ankle joint position sense tests: neutral, inversion, eversion, plantar flexion, and dorsiflexion. Joint position angles were recorded electromechanically using a potentiometer. Passive ankle stiffness was computed from the ratio of applied static moment versus angular displacement. Active ankle stiffness was determined from biomechanical analyses of ankle motion following a mediolateral perturbation. Postural stability was quantified from the center of pressure displacement in the mediolateral and the anteroposterior directions in unipedal stance. All measurements were recorded with and without CAP applied by a pediatric blood pressure cuff. Data were analyzed using a separate mixed-model analysis of variance (ANOVA) for each dependent variable. Post hoc comparison using Tukey's honestly significant difference (HSD) test was performed if significant interactions were obtained. Significance level was set at P<.05 for all analyses. Significant group (high versus low proprioceptive acuity) x CAP interactions were identified for postural stability. Passive ankle stiffness was

  6. Software development for subsonic aircraft’s unsteady longitudinal stability derivatives calculation

    Directory of Open Access Journals (Sweden)

    Maričić Nikola

    2005-01-01

    Full Text Available Subsonic general configuration aircrafts’ unsteady longitudinal aerodynamic stability derivatives can be estimated using finite element methodology based on the Doublet Lattice Method (DLM, the Slender Body Theory (SBT and the Method of Images (MI. Applying this methodology, software DERIV is developed. The obtained results from DERIV are compared to NASTRAN examples HA21A and HA75H. A good agreement is achieved.

  7. Calculating electron cyclotron current drive stabilization of resistive tearing modes in a nonlinear magnetohydrodynamic model

    International Nuclear Information System (INIS)

    Jenkins, Thomas G.; Schnack, Dalton D.; Kruger, Scott E.; Hegna, C. C.; Sovinec, Carl R.

    2010-01-01

    A model which incorporates the effects of electron cyclotron current drive (ECCD) into the magnetohydrodynamic equations is implemented in the NIMROD code [C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004)] and used to investigate the effect of ECCD injection on the stability, growth, and dynamical behavior of magnetic islands associated with resistive tearing modes. In addition to qualitatively and quantitatively agreeing with numerical results obtained from the inclusion of localized ECCD deposition in static equilibrium solvers [A. Pletzer and F. W. Perkins, Phys. Plasmas 6, 1589 (1999)], predictions from the model further elaborate the role which rational surface motion plays in these results. The complete suppression of the (2,1) resistive tearing mode by ECCD is demonstrated and the relevant stabilization mechanism is determined. Consequences of the shifting of the mode rational surface in response to the injected current are explored, and the characteristic short-time responses of resistive tearing modes to spatial ECCD alignments which are stabilizing are also noted. We discuss the relevance of this work to the development of more comprehensive predictive models for ECCD-based mitigation and control of neoclassical tearing modes.

  8. Relations between postural stability, gait and falls in elderly persons--preliminary report.

    Science.gov (United States)

    Baczkowicz, Dawid; Szczegielniak, Jan; Proszkowiec, Małgorzata

    2008-01-01

    Balance control in elderly patients is the area of interest of many researchers. The results of their studies suggest that the measurement of shifts in the centre of foot pressure on the support base (COP) can be used as a tool for identification of fall-prone persons. It is interesting whether there are any relations between functional status, gait, posture stability and the risk of falling. The aim of this study was to find the answer to this question. The study involved 20 patients (mean age 78.1+/-11.6). The functional status of the patients was evaluated according to the Barthel Index. Postural stability was assessed with the use of a Neurocom Balance Master platform. Three measurements were taken with visual feedback (eyes open-EO) and three without visual feedback (eyes closed-EC). Balance control was also evaluated with the Berg test and on the basis of the history of episodes of falling in the preceding six months. Gait was evaluated with the six-minute walking test. The parameters recorded by the force platform showed a significant relation to the values obtained in the Berg test (r=-0.60; pfalls showed a significant relation only to the EO test (r=0.4; pfalls was connected with increased body sway. 3. The functional status of the patient and the balance control evaluation according to the Berg test failed to determine the risk of falling. 4. A relation was observed between postural stability, functional status and gait.

  9. The stability of the water column in french ponds (limousin region by the calculation of the wedderburn number

    Directory of Open Access Journals (Sweden)

    TOUCHART L.

    2014-03-01

    Full Text Available Oxygenation and biological life in lakes, reservoirs and ponds depend on the stability of the water column and on the rhythms of stratification and mixing periods. Slight thermal stratification in ponds often is regarded as the same as instability in shallow lakes. Nevertheless fetch in ponds is very short, what reduces the mixing. Wedderburn number (quotient of the buoyancy by the mixing is used to quantify the stability in shallow water bodies. We calculate it for some ponds in French region Limousin, due to original hourly water temperature measurements in all depths and wind data of Météofrance stations. First results show that very high values (above 10 are frequent in summer and spring period (during 41% of the total time of 2 336 hours from May to July in three ponds. That is why we may consider Limousin ponds as stable stratified bodies of water despite their shallowness. Continuous measurements allow to calculate the diurnal cycle and other time scales of the Wedderburn number, with periods of weakening, when air temperatures and surface water temperatures decrease, wind speed increases and when the wind blows in the same direction with the length of the pond. The most complex variable is the depth of the thermocline; a light increase of the breeze thickens the upper warm layer and strengthens the stability, but an important increase of the wind tends to destroy the stratification.

  10. Assessing the stability of free-energy perturbation calculations by performing variations in the method

    Science.gov (United States)

    Manzoni, Francesco; Ryde, Ulf

    2018-03-01

    We have calculated relative binding affinities for eight tetrafluorophenyl-triazole-thiogalactoside inhibitors of galectin-3 with the alchemical free-energy perturbation approach. We obtain a mean absolute deviation from experimental estimates of only 2-3 kJ/mol and a correlation coefficient (R 2) of 0.5-0.8 for seven relative affinities spanning a range of up to 11 kJ/mol. We also studied the effect of using different methods to calculate the charges of the inhibitor and different sizes of the perturbed group (the atoms that are described by soft-core potentials and are allowed to have differing coordinates). However, the various approaches gave rather similar results and it is not possible to point out one approach as consistently and significantly better than the others. Instead, we suggest that such small and reasonable variations in the computational method can be used to check how stable the calculated results are and to obtain a more accurate estimate of the uncertainty than if performing only one calculation with a single computational setup.

  11. Solid phase stability of molybdenum under compression: Sound velocity measurements and first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiulu [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang, Sichuan (China); Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, 621010 Mianyang, Sichuan (China); Liu, Zhongli [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang, Sichuan (China); College of Physics and Electric Information, Luoyang Normal University, 471022 Luoyang, Henan (China); Jin, Ke; Xi, Feng; Yu, Yuying; Tan, Ye; Dai, Chengda; Cai, Lingcang [Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, 621900 Mianyang, Sichuan (China)

    2015-02-07

    The high-pressure solid phase stability of molybdenum (Mo) has been the center of a long-standing controversy on its high-pressure melting. In this work, experimental and theoretical researches have been conducted to check its solid phase stability under compression. First, we performed sound velocity measurements from 38 to 160 GPa using the two-stage light gas gun and explosive loading in backward- and forward-impact geometries, along with the high-precision velocity interferometry. From the sound velocities, we found no solid-solid phase transition in Mo before shock melting, which does not support the previous solid-solid phase transition conclusion inferred from the sharp drops of the longitudinal sound velocity [Hixson et al., Phys. Rev. Lett. 62, 637 (1989)]. Then, we searched its structures globally using the multi-algorithm collaborative crystal structure prediction technique combined with the density functional theory. By comparing the enthalpies of body centered cubic structure with those of the metastable structures, we found that bcc is the most stable structure in the range of 0–300 GPa. The present theoretical results together with previous ones greatly support our experimental conclusions.

  12. High-throughput DFT calculations of formation energy, stability and oxygen vacancy formation energy of ABO3 perovskites

    Science.gov (United States)

    Emery, Antoine A.; Wolverton, Chris

    2017-10-01

    ABO3 perovskites are oxide materials that are used for a variety of applications such as solid oxide fuel cells, piezo-, ferro-electricity and water splitting. Due to their remarkable stability with respect to cation substitution, new compounds for such applications potentially await discovery. In this work, we present an exhaustive dataset of formation energies of 5,329 cubic and distorted perovskites that were calculated using first-principles density functional theory. In addition to formation energies, several additional properties such as oxidation states, band gap, oxygen vacancy formation energy, and thermodynamic stability with respect to all phases in the Open Quantum Materials Database are also made publicly available. This large dataset for this ubiquitous crystal structure type contains 395 perovskites that are predicted to be thermodynamically stable, of which many have not yet been experimentally reported, and therefore represent theoretical predictions. The dataset thus opens avenues for future use, including materials discovery in many research-active areas.

  13. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    International Nuclear Information System (INIS)

    Wanne, Toivo; Johansson, Erik; Potyondy, David

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  14. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wanne, Toivo; Johansson, Erik; Potyondy, David [Saanio and Riekkola Oy, Helsinki (Finland)

    2004-02-01

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  15. Thermodynamic calculation on the stability of (Fe,Mn){sub 3}AlC carbide in high aluminum steels

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Kwang-Geun [Automotive Steel Products Research Group, POSCO Technical Research Laboratories, POSCO, Jeonnam 545-090 (Korea, Republic of); School of Materials Science and Engineering, Pusan National University, Pusan, 609-735 (Korea, Republic of); Lee, Hyuk-Joong [Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of); Kwak, Jai-Hyun [Automotive Steel Products Research Group, POSCO Technical Research Laboratories, POSCO, Jeonnam 545-090 (Korea, Republic of); Kang, Jung-Yoon [School of Materials Science and Engineering, Pusan National University, Pusan, 609-735 (Korea, Republic of); Lee, Byeong-Joo, E-mail: calphad@postech.ac.k [Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784 (Korea, Republic of)

    2010-08-27

    A CALPHAD type thermodynamic description for the Fe-Mn-Al-C quaternary system has been constructed by combining a newly assessed Mn-Al-C ternary description and a partly modified Fe-Al-C description to an existing thermodynamic database for steels. A special attention was paid to reproduce experimentally reported phase stability of {kappa} carbide in high Al and high Mn steels. This paper demonstrates that the proposed thermodynamic description makes it possible to predict phase equilibria in corresponding alloys with a practically acceptable accuracy. The applicability of the thermodynamic calculation is also demonstrated for the interpretation of microstructural and constitutional evolution during industrial processes for high Al steels.

  16. On the calculation of linear stability with the aid of asymptotic solutions of Orr-Sommerfeld equation, 1

    International Nuclear Information System (INIS)

    Fujimura, Kaoru

    1980-11-01

    The numerical treatment of Orr-Sommerfeld equation which is the fundamental equation of linear hydrodynamic stability theory is described. Present calculation procedure is applied to the two-dimensional quasi-parallel flow for which linearized disturbance equation (Orr-Sommerfeld equation) contains one simple turning point and αR >> 1. The numerical procedure for this problem and one numerical example for Jeffery-Hamel flow (J-H III 1 ) are presented. These treatment can be extended to the other velocity profiles by slight midifications. (author)

  17. Thermodynamic calculation on the stability of (Fe,Mn)3AlC carbide in high aluminum steels

    International Nuclear Information System (INIS)

    Chin, Kwang-Geun; Lee, Hyuk-Joong; Kwak, Jai-Hyun; Kang, Jung-Yoon; Lee, Byeong-Joo

    2010-01-01

    A CALPHAD type thermodynamic description for the Fe-Mn-Al-C quaternary system has been constructed by combining a newly assessed Mn-Al-C ternary description and a partly modified Fe-Al-C description to an existing thermodynamic database for steels. A special attention was paid to reproduce experimentally reported phase stability of κ carbide in high Al and high Mn steels. This paper demonstrates that the proposed thermodynamic description makes it possible to predict phase equilibria in corresponding alloys with a practically acceptable accuracy. The applicability of the thermodynamic calculation is also demonstrated for the interpretation of microstructural and constitutional evolution during industrial processes for high Al steels.

  18. Calculations of the thermal expansion, cohesive energy and thermodynamic stability of a Van der Waals crystal - fullerene C60

    International Nuclear Information System (INIS)

    Zubov, V.I.; Tretiakov, N.P.; Teixeira Rabelo, J.N.; Sanchez Ortiz, J.F.

    1994-01-01

    The temperature dependence of the intermolecular distance and the cohesive energy in the high-temperature modification of C 60 solid fullerene was studied on basis of the correlative method of unsymmetrized self-consistent field. The central intermolecular potential of Girifalco and its approximation by Yakub were used. We conclude about the decisive role of anharmonic effects at high temperatures. The discrepancy between the calculated and experimental values of intermolecular distance does not exceed 0.8% on the whole temperature interval. The temperature of loss of thermodynamic stability was obtained (∼1915 K) and a possible melting temperature was estimated (∼1400 K). ((orig.))

  19. Turbulent piloted partially-premixed flames with varying levels of O2/N2: stability limits and PDF calculations

    Science.gov (United States)

    Juddoo, Mrinal; Masri, Assaad R.; Pope, Stephen B.

    2011-12-01

    This paper reports measured stability limits and PDF calculations of piloted, turbulent flames of compressed natural gas (CNG) partially-premixed with either pure oxygen, or with varying levels of O2/N2. Stability limits are presented for flames of CNG fuel premixed with up to 20% oxygen as well as CNG-O2-N2 fuel where the O2 content is varied from 8 to 22% by volume. Calculations are presented for (i) Sydney flame B [Masri et al. 1988] which uses pure CNG as well as flames B15 to B25 where the CNG is partially-premixed with 15-25% oxygen by volume, respectively and (ii) Sandia methane-air (1:3 by volume) flame E [Barlow et al. 2005] as well as new flames E15 and E25 that are partially-premixed with 'reconstituted air' where the O2 content in nitrogen is 15 and 25% by volume, respectively. The calculations solve a transported PDF of composition using a particle-based Monte Carlo method and employ the EMST mixing model as well as detailed chemical kinetics. The addition of oxygen to the fuel increases stability, shortens the flames, broadens the reaction zone, and shifts the stoichiometric mixture fraction towards the inner side of the jet. It is found that for pure CNG flames where the reaction zone is narrow (∼0.1 in mixture fraction space), the PDF calculations fail to reproduce the correct level of local extinction on approach to blow-off. A broadening in the reaction zone up to about 0.25 in mixture fraction space is needed for the PDF/EMST approach to be able to capture these finite-rate chemistry effects. It is also found that for the same level of partial premixing, increasing the O2/N2 ratio increases the maximum levels of CO and NO but shifts the peak to richer mixture fractions. Over the range of oxygenation investigated here, stability limits have shown to improve almost linearly with increasing oxygen levels in the fuel and with increasing the contribution of release rate from the pilot.

  20. Preliminary numerical simulation for shallow strata stability of coral reef in South China Sea

    Science.gov (United States)

    Tang, Qinqin; Zhan, Wenhuan; Zhang, Jinchang

    2017-04-01

    Coral reefs are the geologic material and special rock and soil, which live in shallow water of the tropic ocean and are formed through biological and geological action. Since infrastructure construction is being increasingly developed on coral reefs during recent years, it is necessary to evaluate the shallow strata stability of coral reefs in the South China Sea. The paper is to study the borehole profiles for shallow strata of coral reefs in the South China Sea, especially in the hydrodynamic marine environment?, and to establish a geological model for numerical simulation with Geo-Studio software. Five drilling holes show a six-layer shallow structure of South China Sea, including filling layer, mid-coarse sand, coral sand gravel, fine sand, limestone debris and reef limestone. The shallow coral reef profile next to lagoon is similar to "layers cake", in which the right side close to the sea is analogous to "block cake". The simulation results show that coral reef stability depends on wave loads and earthquake strength, as well as the physical properties of coral reefs themselves. The safety factor of the outer reef is greater than 10.0 in the static condition, indicating that outer reefs are less affected by the wave and earthquake. However, the safety factor next to lagoon is ranging from 0.1 to 4.9. The main reason for the variations that the strata of coral reefs close to the sea are thick. For example, the thickness of reef limestone is more than 10 m and equivalent to the block. When the thickness of inside strata is less than 10 m, they show weak engineering geological characteristics. These findings can provide useful information for coral reef constructions in future. This work was funded by National Basic Research Program of China (contract: 2013CB956104) and National Natural Science Foundation of China (contract: 41376063).

  1. Quantum Mechanical Calculations Of Elastic Properties Of Doped Tetragonal Yttria-Stabilized Zirconium Dioxide

    Directory of Open Access Journals (Sweden)

    Yuriy Natanzon

    2008-01-01

    Full Text Available We report first principles calculations of the electronic and elastic properties of yttriastabilized tetragonal zirconium dioxide doped with metal oxides like: GeO2, TiO2, SiO2,MgO and Al2O3. It is shown that addition of such dopants affects selected elastic propertiesof ZrO2, which is driven by the attraction of electron density by dopant atom and creationof stronger dopant–oxygen bonds. This effect contributes to the increase of superplasticityof doped material.

  2. Preliminary Study of Long-term Geological Stability for HLW Disposal in Korea

    International Nuclear Information System (INIS)

    Hwang, Jae Ha; Kim, Ju Yong; Cho, Deung Lyong

    2004-02-01

    It was summarized previous works of the Al-in-hornblende geobarometer to quantify emplacement depths of the Cretaceous Bulgugsa granites and the Triassic-Jurassic Daebo granites in Korea. When calculated using the equation of Schmidt, the emplacement pressures of the Bulgugsa granites are less than 2.8 kb and those of the Daebo granites range from 3.4 to 7.8 kb. Assuming that the crustal thickness varies simply due to erosion and uplift, the crustal thickness of South Korea during the Jurassic can be calculated by adding average emplacement depth of the Jurassic granites to average thickness of present-day crust, which corresponds to about 50 km. The lower I terrace among the marine terraces had been formed in the Last Interglacial culmination stage(MIS 5e) by the amino-acid date, the identification of Ata tephra, the pollen assemblage and the relationships with the thalassostatic terrace of the Last Interglacial culmination stage, respectively. Ancient shoreline height of the lower marine terrace I is 18m on the whole southeastern coast of Korea. Therefore, if we assume that the sea level of the last Interglacial culmination period(125ka BP) was 6m higher than that of the present, the amount of net uplift since the last Interglacial culmination is about 12m, and if we suppose a constant-rate uplift, then the uplift rate in the southeastern coast area will be about 0.1m/ka

  3. Effect of alloying elements on the stability of Ni2M in Alloy690 based upon thermodynamic calculation

    International Nuclear Information System (INIS)

    Horiuchi, Toshiaki; Kuwano, Kazuhiro; Satoh, Naohiro

    2012-01-01

    Some researchers recently point out that Ni based alloys used in nuclear power plants have the ordering tendency, which is a potential to decrease mechanical properties within the expected lifetime of the plants. In the present study, authors evaluated the effect of 8 alloying elements on the ordering tendency in Alloy690 based upon thermodynamic calculation by Thermo-Calc. It is clarified that the additive amount of Fe, Cr, Ti and Si, particularly Fe and Cr, was influential for the stability of Ni 2 M, while that of Mn, Cu, B and C had almost no effect for that. Authors therefore designed the Ni 2 M stabilized alloy by no addition of Fe in Alloy690. Ni 2 M is estimated to be stable even at 773 K in the Ni 2 M stabilized alloy. The influence by long range ordering or precipitating of Ni 2 M in Alloy690 for mechanical properties or SCC susceptibility is expected to be clarified by the sample obtained in the present study. (author)

  4. Preliminary model validation for integral stability behavior in molten salt natural circulation

    International Nuclear Information System (INIS)

    Cai Chuangxiong; He Zhaozhong; Chen Kun

    2017-01-01

    Passive safety system is an important characteristic of Fluoride-Salt-Cooled High-Temperature Reactor (FHR). In order to remove the decay heat, a direct reactor auxiliary cooling system (DRACS) which uses the passive safety technology is proposed to the FHR as the ultimate heat sink. The DRACS is relying on the natural circulation, so the study of molten salt natural circulation plays an important role at TMSR. A high-temperature molten salt natural circulation test loop has been designed and constructed at the TMSR center of the Chinese Academy of Sciences (CAS) to understand the characteristics of the natural circulation and verify the design model. It adopts nitrate salt as the working fluid to simulate fluoride salts, and uses air as the ultimate heat sink. The test shows the operation very well and has a very nice performance, the Heat transfer coefficients (salt-salt or salt-air), power of the loop, heat loss of molten salt pool (or molten salt pipe or air cooling tower), starting time of the loop, flow rate that can be verified in this loop. A series of experiments have been done and the results show that the experimental data are well matched with the design data. This paper aims at analyzing the molten salt circulation model, studying the characteristics of the natural circulation, and verifying the Integral stability behavior by three different natural circulation experiments. Also, the experiment is going on, and more experiments will been carry out to study the molten salt natural circulation for optimizing the design. (author)

  5. High pressure stability of lithium metatitanate and metazirconate: Insight from experiments & ab-initio calculations

    Science.gov (United States)

    Chitnis, Abhishek; Chakraborty, B.; Tripathi, B. M.; Tyagi, A. K.; Garg, Nandini

    2018-02-01

    Lithium metatitanate (LTO) and lithium metazirconate (LZO) are lithium rich ceramics which can be used as tritium breeder materials for thermonuclear reactors. In-situ x-ray diffraction and ab-initio studies at high pressure show that LTO has a higher bulk modulus than that of LZO. In fact these studies indicate that they are the least compressible of the known lithium rich ceramics like Li2O or Li4SiO4, which are potential candidates for blanket materials. These studies show that the TiO6 octahedra are responsible for the higher bulk modulus of LTO when compared to that of LZO. It has also been shown that the compressibility and distortion of the softer LiO6 octahedra can be controlled by altering the stacking sequence of the more rigid covalently bonded octahedra. This knowledge can be used by chemists to design new lithium based ceramics with higher bulk modulus. It was observed that LTO was stable upto 34 GPa. Ab initio DFT calculations helped to understand the anisotropy in compressibility of both LZO and LTO. This study also shows, that even though the empirical potentials developed by Vijaykumar et al. successfully determine the ambient pressure structure of lithium metatitanate, they cannot be used at non ambient conditions like high pressure [1].

  6. Stability, electronic structures, and mechanical properties of Fe–Mn–Al system from first-principles calculations

    International Nuclear Information System (INIS)

    Liu Ya-Hui; Chong Xiao-Yu; Jiang Ye-Hua; Feng Jing

    2017-01-01

    The stability, electronic structures, and mechanical properties of the Fe–Mn–Al system were determined by first-principles calculations. The formation enthalpy and cohesive energy of these Fe–Mn–Al alloys are negative and show that the alloys are thermodynamically stable. Fe 3 Al, with the lowest formation enthalpy, is the most stable compound in the Fe–Mn–Al system. The partial density of states, total density of states, and electron density distribution maps of the Fe– Mn–Al alloys were analyzed. The bonding characteristics of these Fe–Mn–Al alloys are mainly combinations of covalent bonding and metallic bonds. The stress-strain method and Voigt–Reuss–Hill approximation were used to calculate the elastic constants and moduli, respectively. Fe 2.5 Mn 0.5 Al has the highest bulk modulus, 234.5 GPa. Fe 1.5 Mn 1.5 Al has the highest shear modulus and Young’s modulus, with values of 98.8 GPa and 259.2 GPa, respectively. These Fe–Mn–Al alloys display disparate anisotropies due to the calculated different shape of the three-dimensional curved surface of the Young’s modulus and anisotropic index. Moreover, the anisotropic sound velocities and Debye temperatures of these Fe–Mn–Al alloys were explored. (paper)

  7. Manual for calculating critical loads of heavy metals for soils and surface waters; preliminary guidelines for environmental quality criteria, calculation methods and input data

    NARCIS (Netherlands)

    Vries, de W.; Bakker, D.J.

    1996-01-01

    Methodologies are described for calculating critical loads of lead, cadmium, copper, zinc, nickel, chromium and mercury for soils and surface waters. The aspects which are discussed are: selection of a computation model, determination of environmental-quality criteria for the metals, collection of

  8. Calculation of the relative chemical stabilities of proteins as a function of temperature and redox chemistry in a hot spring.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Dick

    Full Text Available Uncovering the chemical and physical links between natural environments and microbial communities is becoming increasingly amenable owing to geochemical observations and metagenomic sequencing. At the hot spring known as Bison Pool in Yellowstone National Park, the cooling of the water in the outflow channel is associated with an increase in oxidation potential estimated from multiple field-based measurements. Representative groups of proteins whose sequences were derived from metagenomic data also exhibit an increase in average oxidation state of carbon in the protein molecules with distance from the hot-spring source. The energetic requirements of reactions to form selected proteins used in the model were computed using amino-acid group additivity for the standard molal thermodynamic properties of the proteins, and the relative chemical stabilities of the proteins were investigated by varying temperature, pH and oxidation state, expressed as activity of dissolved hydrogen. The relative stabilities of the proteins were found to track the locations of the sampling sites when the calculations included a function for hydrogen activity that increases with temperature and is higher, or more reducing, than values consistent with measurements of dissolved oxygen, sulfide and oxidation-reduction potential in the field. These findings imply that spatial patterns in the amino acid compositions of proteins can be linked, through energetics of overall chemical reactions representing the formation of the proteins, to the environmental conditions at this hot spring, even if microbial cells maintain considerably different internal conditions. Further applications of the thermodynamic calculations are possible for other natural microbial ecosystems.

  9. Charge compensation and electrostatic transferability in three entropy-stabilized oxides: Results from density functional theory calculations

    Energy Technology Data Exchange (ETDEWEB)

    Rak, Zs.; Rost, C. M.; Lim, M.; Maria, J.-P.; Brenner, D. W. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7907 (United States); Sarker, P.; Toher, C.; Curtarolo, S. [Department of Mechanical Engineering and Materials Science and Center for Materials Genomics, Duke University, Durham, North Carolina 27708 (United States)

    2016-09-07

    Density functional theory calculations were carried out for three entropic rocksalt oxides, (Mg{sub 0.1}Co{sub 0.1}Ni{sub 0.1}Cu{sub 0.1}Zn{sub 0.1})O{sub 0.5}, termed J14, and J14 + Li and J14 + Sc, to understand the role of charge neutrality and electronic states on their properties, and to probe whether simple expressions may exist that predict stability. The calculations predict that the average lattice constants of the ternary structures provide good approximations to that of the random structures. For J14, Bader charges are transferable between the binary, ternary, and random structures. For J14 + Sc and J14 + Li, average Bader charges in the entropic structures can be estimated from the ternary compositions. Addition of Sc to J14 reduces the majority of Cu, which show large displacements from ideal lattice sites, along with reduction of a few Co and Ni cations. Addition of Li to J14 reduces the lattice constant, consistent with experiment, and oxidizes some of Co as well as some of Ni and Cu. The Bader charges and spin-resolved density of states (DOS) for Co{sup +3} in J14 + Li are very different from Co{sup +2}, while for Cu and Ni the Bader charges form continuous distributions and the two DOS are similar for the two oxidation states. Experimental detection of different oxidation states may therefore be challenging for Cu and Ni compared to Co. Based on these results, empirical stability parameters for these entropic oxides may be more complicated than those for non-oxide entropic solids.

  10. Evaluation of the stability and precipitation behavior of G phase in dual-phase stainless steels by thermodynamic calculations

    International Nuclear Information System (INIS)

    Horiuchi, Toshiaki; Ito, Shota; Minamoto, Satoshi

    2017-01-01

    Degradation of dual-phase stainless steel in nuclear power plants due to thermal ageing during long-term use is an important issue. This occurs mainly due to breakdown of the ferrite phase as a result of spinodal decomposition, followed by clustering or precipitation of the intermetallic G-phase compound, 'Ni 16 Si 7 Mn 6 ', which consists primarily of Ni, Si and Mn. The degradation mechanism is complicated because both radiation effects and thermal ageing simultaneously occur. However, only limited information is available concerning this phenomenon, and particularly regarding precipitation of the G phase. In the present study, thermodynamic equilibrium calculations were carried out for two types of dual-phase stainless steel (weld metal and cast steel) to evaluate the influence of the temperature and constituent elements on the stability of the G phase. The calculations were performed using the Thermo-Calc program with the thermodynamic database, FE-DATA (ver. 6). Precipitation of the G phase was investigated using the TC-PRISMA precipitation module together with the MOB2 diffusion database. It was found that for both types of steel, the G phase contains not only Ni, Si and Mn, but also small amounts of Fe and Cr. The stability of the G phase is dependent on the Ni, Mn, Cr, Si and Mo content in the original steel, and particularly on that of the latter two elements. Due to its higher Si content, the G phase was shown to be more stable in cast steel than in weld metal. (author)

  11. Preliminary calculations for the CAFE project (Clean Air For Europe); Calculs preparatoires pour la strategie thematique CAFE (Clean Air For Europe)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-09-15

    The European Commission decided in 2001 an analysis program to reduce the atmospheric emissions. This report presents different limit scenari for France in 2020 (the reference scenari and the MTFR scenari, Maximum Technically Feasible Reduction), optimized scenari calculated by the RAINS model (Regional Air Pollution Information and Simulation), the costs of the scenari calculated with RAINS and the cost-benefit analysis of the strategy CAFE. From the study results, the benefits are higher than the costs, even with the most ambitious scenari. At an european level the emission reduction strategies have no effect on the employment but an impact on the Gross Domestic Product (decrease between 0,04 % and 0,12 % in function of the scenari). (A.L.B.)

  12. Crystal structures, stability, electronic and elastic properties of 4d and 5d transition metal monoborides: First-principles calculations

    International Nuclear Information System (INIS)

    Wang, Y.; Chen, W.; Chen, X.; Liu, H.Y.; Ding, Z.H.; Ma, Y.M.; Wang, X.D.; Cao, Q.P.; Jiang, J.Z.

    2012-01-01

    Highlights: ► Changes from NaCl-, WC- to anti-NiAs-type structures are for 4d and 5d metal monoborides. ► Vickers hardnesses of monoborides are relatively low. ► B-vacancies cause the difference in lattice parameters for IrB and PtB. ► Nonstoichiometric IrB and PtB phases synthesized. - Abstract: The crystal structures, stability, electronic and elastic properties of 4d and 5d transition metal monoborides have been studied by first principles calculations. It is found that NaCl-type ZrB, NbB, MoB, HfB, TaB and WB, WC-type TcB, RuB, ReB, OsB and IrB, and anti-NiAs-type RhB and PdB are thermodynamically stable at zero pressure. They all are metallic. The Vickers hardnesses of these monoborides are relatively low as compared with monocarbides and mononitrides. It is clarified that the presence of B-vacancies is the origin for the difference of lattice parameters between theoretical and experimental results for WC-type IrB and anti-NiAs-type PtB while IrB and PtB with stoichiometry from calculations are revealed to be mechanically unstable and dynamically unstable, respectively.

  13. Crystal structures, stability, electronic and elastic properties of 4d and 5d transition metal monoborides: First-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Chen, W. [International Center for New-Structured Materials (ICNSM), Zhejiang University, and Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Chen, X.; Liu, H.Y. [State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Ding, Z.H.; Ma, Y.M. [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130012 (China); Wang, X.D.; Cao, Q.P. [International Center for New-Structured Materials (ICNSM), Zhejiang University, and Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Jiang, J.Z., E-mail: jiangjz@zju.edu.cn [International Center for New-Structured Materials (ICNSM), Zhejiang University, and Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Changes from NaCl-, WC- to anti-NiAs-type structures are for 4d and 5d metal monoborides. Black-Right-Pointing-Pointer Vickers hardnesses of monoborides are relatively low. Black-Right-Pointing-Pointer B-vacancies cause the difference in lattice parameters for IrB and PtB. Black-Right-Pointing-Pointer Nonstoichiometric IrB and PtB phases synthesized. - Abstract: The crystal structures, stability, electronic and elastic properties of 4d and 5d transition metal monoborides have been studied by first principles calculations. It is found that NaCl-type ZrB, NbB, MoB, HfB, TaB and WB, WC-type TcB, RuB, ReB, OsB and IrB, and anti-NiAs-type RhB and PdB are thermodynamically stable at zero pressure. They all are metallic. The Vickers hardnesses of these monoborides are relatively low as compared with monocarbides and mononitrides. It is clarified that the presence of B-vacancies is the origin for the difference of lattice parameters between theoretical and experimental results for WC-type IrB and anti-NiAs-type PtB while IrB and PtB with stoichiometry from calculations are revealed to be mechanically unstable and dynamically unstable, respectively.

  14. Calculation of hydrogen and oxygen uptake in fuel rod cladding during severe accidents using the integral diffusion method -- Preliminary design report

    International Nuclear Information System (INIS)

    Siefken, L.J.

    1999-01-01

    Preliminary designs are described for models of hydrogen and oxygen uptake in fuel rod cladding during severe accidents. Calculation of the uptake involves the modeling of seven processes: (1) diffusion of oxygen from the bulk gas into the boundary layer at the external cladding surface, (2) diffusion from the boundary layer into the oxide layer, (3) diffusion from the inner surface of the oxide layer into the metallic part of the cladding, (4) uptake of hydrogen in the event that the cladding oxide layer is dissolved in a steam-starved region, (5) embrittlement of cladding due to hydrogen uptake, (6) cracking of cladding during quenching due to its embrittlement and (7) release of hydrogen from the cladding after cracking of the cladding. An integral diffusion method is described for calculating the diffusion processes in the cladding. Experimental results are presented that show a rapid uptake of hydrogen in the event of dissolution of the oxide layer and a rapid release of hydrogen in the event of cracking of the oxide layer. These experimental results are used as a basis for calculating the rate of hydrogen uptake and the rate of hydrogen release. The uptake of hydrogen is limited to the equilibrium solubility calculated by applying Sievert's law. The uptake of hydrogen is an exothermic reaction that accelerates the heatup of a fuel rod. An embrittlement criteria is described that accounts for hydrogen and oxygen concentration and the extent of oxidation. A design is described for implementing the models for hydrogen and oxygen uptake and cladding embrittlement into the programming framework of the SCDAP/RELAP5 code. A test matrix is described for assessing the impact of the proposed models on the calculated behavior of fuel rods in severe accident conditions. This report is a revision and reissue of the report entitled; ''Preliminary Design Report for Modeling of Hydrogen Uptake in Fuel Rod Cladding During Severe Accidents.''

  15. Stabilization

    Directory of Open Access Journals (Sweden)

    Muhammad H. Al-Malack

    2016-07-01

    Full Text Available Fuel oil flyash (FFA produced in power and water desalination plants firing crude oils in the Kingdom of Saudi Arabia is being disposed in landfills, which increases the burden on the environment, therefore, FFA utilization must be encouraged. In the current research, the effect of adding FFA on the engineering properties of two indigenous soils, namely sand and marl, was investigated. FFA was added at concentrations of 5%, 10% and 15% to both soils with and without the addition of Portland cement. Mixtures of the stabilized soils were thoroughly evaluated using compaction, California Bearing Ratio (CBR, unconfined compressive strength (USC and durability tests. Results of these tests indicated that stabilized sand mixtures could not attain the ACI strength requirements. However, marl was found to satisfy the ACI strength requirement when only 5% of FFA was added together with 5% of cement. When the FFA was increased to 10% and 15%, the mixture’s strength was found to decrease to values below the ACI requirements. Results of the Toxicity Characteristics Leaching Procedure (TCLP, which was performed on samples that passed the ACI requirements, indicated that FFA must be cautiously used in soil stabilization.

  16. Contracts, Vouchers, and Child Care Subsidy Stability: A Preliminary Look at Associations between Subsidy Payment Mechanism and Stability of Subsidy Receipt

    Science.gov (United States)

    Holod, Aleksandra; Johnson, Anna D.; Martin, Anne; Gardner, Margo; Brooks-Gunn, Jeanne

    2012-01-01

    Background: The federal child care subsidy program, funded through the Child Care and Development Fund (CCDF), is the nation's largest public investment in early child care. However, little is known about whether and how subsidy payment mechanisms relate to the stability of subsidy receipt or the stability of children's care arrangements.…

  17. Preliminary neutron shielding calculations of the electronics in the EAST BES systems focusing on neutron induced displacement damage

    Energy Technology Data Exchange (ETDEWEB)

    Náfrádi, Gábor, E-mail: nafradi@reak.bme.hu [Institute of Nuclear Techniques (NTI), Budapest University of Technology and Economics (BME), H-1111 Budapest (Hungary); Kovácsik, Ákos, E-mail: kovacsik.akos@reak.bme.hu [Institute of Nuclear Techniques (NTI), Budapest University of Technology and Economics (BME), H-1111 Budapest (Hungary); Németh, József, E-mail: nemeth.jozsef@wigner.mta.hu [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics (Wigner RCP), Hungarian Academy of Sciences (HAS), POB 49, 1525 Budapest (Hungary); Pór, Gábor, E-mail: por@reak.bme.hu [Institute of Nuclear Techniques (NTI), Budapest University of Technology and Economics (BME), H-1111 Budapest (Hungary); Zoletnik, Sándor, E-mail: zoletnik.sandor@wigner.mta.hu [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics (Wigner RCP), Hungarian Academy of Sciences (HAS), POB 49, 1525 Budapest (Hungary)

    2016-11-15

    Monte Carlo N-Particle (MCNP) calculations were carried out to compare neutron shielding capabilities of three frequently used neutron shielding materials: polyethylene without neutron absorbers, polyethylene with boron absorbers and polyethylene with lithium absorbers, according to Non Ionizing Energy Loss (NIEL). The results of 1D shielding calculations showed that simple neutron moderating materials can provide sufficient and cheap shielding against 2.45 MeV and 14.1 MeV fusion neutrons, in terms of 1 MeV neutron equivalent flux, in silicon targets, which is the most commonly used material of electronic components. Based on these results a new shielding concept is proposed which can be taken into consideration where the reduction of displacement damage is the main goal and the free space available for shielding is limited. Based on this shielding concept detailed 3D calculations were carried out to describe the properties of the neutron shielding of the Beam Emission Spectroscopy (BES) system installed at the EAST tokamak.

  18. Ratio of thyroid radioiodine uptake calculated via the physic decay rate of the standard radioactive source: a preliminary study

    International Nuclear Information System (INIS)

    Zeng Yu; Zhou Luyi

    2010-01-01

    Objectives: To compare the difference of the ratio of thyroid radioiodine ( 131 I) uptake calculated by actually measuring counts of the standard radioactive source(method 1) and by computing counts of the standard radioactive source via physic half life of 131 I (method 2). Methods: Two hundred and nine consecutive patients with Graves' Disease were prospectively recruited. The ratio of thyroid 131 I uptake was calculated by two methods at 4 h and 24 h after administration of 1.48 MBq 131 I, respectively. Paired t-test was used to compare the difference between the two methods. Results: The ratio of thyroid 131 I uptake at 4h was (32±16)% and ( 35±10)% (t=1.98, P=0.20), at 24h (72±19)% and (69±24)% ( t=1.49, P=0.23), respectively, by the two methods. Conclusion: To calculate the ratio of thyroid 131 I uptake via the physic half life of the standard radioactive resource is feasible, and can both reduce the risk of ionizing radiation to technical staff and act as verifying method for quality control of thyroid function equipment. (authors)

  19. SU-E-T-632: Preliminary Study On Treating Nose Skin Using Energy and Intensity Modulated Electron Beams with Monte Carlo Based Dose Calculations

    International Nuclear Information System (INIS)

    Jin, L; Eldib, A; Li, J; Price, R; Ma, C

    2015-01-01

    Purpose: Uneven nose surfaces and air cavities underneath and the use of bolus present complexity and dose uncertainty when using a single electron energy beam to plan treatments of nose skin with a pencil beam-based planning system. This work demonstrates more accurate dose calculation and more optimal planning using energy and intensity modulated electron radiotherapy (MERT) delivered with a pMLC. Methods: An in-house developed Monte Carlo (MC)-based dose calculation/optimization planning system was employed for treatment planning. Phase space data (6, 9, 12 and 15 MeV) were used as an input source for MC dose calculations for the linac. To reduce the scatter-caused penumbra, a short SSD (61 cm) was used. Our previous work demonstrates good agreement in percentage depth dose and off-axis dose between calculations and film measurement for various field sizes. A MERT plan was generated for treating the nose skin using a patient geometry and a dose volume histogram (DVH) was obtained. The work also shows the comparison of 2D dose distributions between a clinically used conventional single electron energy plan and the MERT plan. Results: The MERT plan resulted in improved target dose coverage as compared to the conventional plan, which demonstrated a target dose deficit at the field edge. The conventional plan showed higher dose normal tissue irradiation underneath the nose skin while the MERT plan resulted in improved conformity and thus reduces normal tissue dose. Conclusion: This preliminary work illustrates that MC-based MERT planning is a promising technique in treating nose skin, not only providing more accurate dose calculation, but also offering an improved target dose coverage and conformity. In addition, this technique may eliminate the necessity of bolus, which often produces dose delivery uncertainty due to the air gaps that may exist between the bolus and skin

  20. Calculating the wind energy input to a system using a spatially explicit method that considers atmospheric stability

    Science.gov (United States)

    Atmospheric stability has a major effect in determining the wind energy doing work in the atmospheric boundary layer (ABL); however, it is seldom considered in determining this value in emergy analyses. One reason that atmospheric stability is not usually considered is that a sui...

  1. Is it possible to preserve lumbar lordosis after hybrid stabilization? Preliminary results of a novel rigid-dynamic stabilization system in degenerative lumbar pathologies.

    Science.gov (United States)

    Formica, Matteo; Cavagnaro, Luca; Basso, Marco; Zanirato, Andrea; Felli, Lamberto; Formica, Carlo

    2015-11-01

    To evaluate the results of a novel rigid-dynamic stabilization technique in lumbar degenerative segment diseases (DSD), expressly pointing out the preservation of postoperative lumbar lordosis (LL). Forty-one patients with one level lumbar DSD and initial disc degeneration at the adjacent level were treated. Circumferential lumbar arthrodesis and posterior hybrid instrumentation were performed to preserve an initial disc degeneration above the segment that has to be fused. Clinical and spino-pelvic parameters were evaluated pre- and postoperatively. At 2-year follow-up, a significant improvement of clinical outcomes was reported. No statistically significant difference was noted between postoperative and 2-year follow-up in LL and in disc/vertebral body height ratio at the upper adjacent fusion level. When properly selected, this technique leads to good results. A proper LL should be achieved after any hybrid stabilization to preserve the segment above the fusion.

  2. Treatment compliance and effectiveness in complex PTSD patients with co-morbid personality disorder undergoing stabilizing cognitive behavioral group treatment: a preliminary study

    Directory of Open Access Journals (Sweden)

    Ethy Dorrepaal

    2013-11-01

    Full Text Available Background: In the empirical and clinical literature, complex posttraumatic stress disorder (PTSD and personality disorders (PDs are suggested to be predictive of drop-out or reduced treatment effectiveness in trauma-focused PTSD treatment. Objective: In this study, we aimed to investigate if personality characteristics would predict treatment compliance and effectiveness in stabilizing complex PTSD treatment. Method: In a randomized controlled trial on a 20-week stabilizing group cognitive behavioral treatment (CBT for child-abuse-related complex PTSD, we included 71 patients of whom 38 were randomized to a psycho-educational and cognitive behavioral stabilizing group treatment. We compared the patients with few PD symptoms (adaptive (N=14 with the non-adaptive patients (N=24 as revealed by a cluster analysis. Results: We found that non-adaptive patients compared to the adaptive patients showed very low drop-out rates. Both non-adaptive patients, classified with highly different personality profiles “withdrawn” and “aggressive,” were equally compliant. With regard to symptom reduction, we found no significant differences between subtypes. Post-hoc, patients with a PD showed lower drop-out rates and higher effect sizes in terms of complex PTSD severity, especially on domains that affect regulation and interpersonal problems. Conclusion: Contrary to our expectations, these preliminary findings indicate that this treatment is well tolerated by patients with a variety of personality pathology. Larger sample sizes are needed to study effectiveness for subgroups of complex PTSD patients.

  3. First-principles density functional calculation of electrochemical stability of fast Li ion conducting garnet-type oxides.

    Science.gov (United States)

    Nakayama, Masanobu; Kotobuki, Masashi; Munakata, Hirokazu; Nogami, Masayuki; Kanamura, Kiyoshi

    2012-07-28

    The research and development of rechargeable all-ceramic lithium batteries are vital to realize their considerable advantages over existing commercial lithium ion batteries in terms of size, energy density, and safety. A key part of such effort is the development of solid-state electrolyte materials with high Li(+) conductivity and good electrochemical stability; lithium-containing oxides with a garnet-type structure are known to satisfy the requirements to achieve both features. Using first-principles density functional theory (DFT), we investigated the electrochemical stability of garnet-type Li(x)La(3)M(2)O(12) (M = Ti, Zr, Nb, Ta, Sb, Bi; x = 5 or 7) materials against Li metal. We found that the electrochemical stability of such materials depends on their composition and structure. The electrochemical stability against Li metal was improved when a cation M was chosen with a low effective nuclear charge, that is, with a high screening constant for an unoccupied orbital. In fact, both our computational and experimental results show that Li(7)La(3)Zr(2)O(12) and Li(5)La(3)Ta(2)O(12) are inert to Li metal. In addition, the linkage of MO(6) octahedra in the crystal structure affects the electrochemical stability. For example, perovskite-type La(1/3)TaO(3) was found, both experimentally and computationally, to react with Li metal owing to the corner-sharing MO(6) octahedral network of La(1/3)TaO(3), even though it has the same constituent elements as garnet-type Li(5)La(3)Ta(2)O(12) (which is inert to Li metal and features isolated TaO(6) octahedra).

  4. A preliminary study of the metabolic stability of a series of benzoxazinone derivatives as potent neuropeptide Y5 antagonists.

    Science.gov (United States)

    Dordal, Alberto; Lipkin, Mike; Macritchie, Jackie; Mas, Josep; Port, Adriana; Rose, Sally; Salgado, Leonardo; Savic, Vladimir; Schmidt, Wolfgang; Serafini, Maria Teresa; Spearing, William; Torrens, Antoni; Yeste, Sandra

    2005-08-15

    The metabolic stability of benzoxazinone derivatives, a potent series of NPY Y5 antagonists, has been investigated. This study resulted in the identification of the structural moieties prone to metabolic transformations and which strongly influenced the in vitro half-life. This provides opportunities to optimize the structure of this new class of NPY Y5 antagonists.

  5. Influence of stability classification on atmospheric diffusion calculations for elevated releases over a terrain of major roughness

    International Nuclear Information System (INIS)

    Hu Erbang

    1988-01-01

    A series (22) of atmospheric tracer experiments with 100m release height have been performed at the kernforschungszentrum karlsruhe (KfK) of West Germany over a terrain of major roughness (Z 0 = 1.5 m). The concentration data of the tracers are statistically analysed in which 5 methods of stability classification are used. The results show that the normalized diffusion factors predicted by Gaussian plume dispersion model is in good agreement with the observed ones for elevated releases over a terrain of major roughness. Differnent sets of dispersion parameters could be obtained for the same series of atmospheric tracer experiments if different methods of classification are applied. The same method of stability classification should be used for the application of these dispersion parameters to evaluate the environment impact

  6. Lattice stabilities, mechanical and thermodynamic properties of Al3Tm and Al3Lu intermetallics under high pressure from first-principles calculations

    Science.gov (United States)

    Xu-Dong, Zhang; Wei, Jiang

    2016-02-01

    The effects of high pressure on lattice stability, mechanical and thermodynamic properties of L12 structure Al3Tm and Al3Lu are studied by first-principles calculations within the VASP code. The phonon dispersion curves and density of phonon states are calculated by using the PHONONPY code. Our results agree well with the available experimental and theoretical values. The vibrational properties indicate that Al3Tm and Al3Lu keep their dynamical stabilities in L12 structure up to 100 GPa. The elastic properties and Debye temperatures for Al3Tm and Al3Lu increase with the increase of pressure. The mechanical anisotropic properties are discussed by using anisotropic indices AG, AU, AZ, and the three-dimensional (3D) curved surface of Young’s modulus. The calculated results show that Al3Tm and Al3Lu are both isotropic at 0 GPa and anisotropic under high pressure. In the present work, the sound velocities in different directions for Al3Tm and Al3Lu are also predicted under high pressure. We also calculate the thermodynamic properties and provide the relationships between thermal parameters and temperature/pressure. These results can provide theoretical support for further experimental work and industrial applications. Project supported by the Scientific Technology Plan of the Educational Department of Liaoning Province and Liaoning Innovative Research Team in University, China (Grant No. LT2014004) and the Program for the Young Teacher Cultivation Fund of Shenyang University of Technology, China (Grant No. 005612).

  7. Investigation of Iron-based double perovskite oxides on the magnetic phase stability, mechanical, electronic and optical properties via first-principles calculation

    Energy Technology Data Exchange (ETDEWEB)

    Rached, H., E-mail: habib_rached@yahoo.fr [Laboratoire des Matériaux Magnétiques, Faculté des Sciences Exactes, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès, 22000 (Algeria); Département de Physique, Faculté des Sciences Exactes et Informatique, Université Hassiba BenBouali de Chlef, Chlef, 02000 (Algeria); Bendaoudia, S. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences Exactes, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès, 22000 (Algeria); Rached, D., E-mail: rachdj@yahoo.fr [Laboratoire des Matériaux Magnétiques, Faculté des Sciences Exactes, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès, 22000 (Algeria)

    2017-06-01

    The main goal of the present work is to obtain report on the magnetic phase stability, mechanical, electronic and optical properties of double perovskite oxides Pb{sub 2}FeMO{sub 6} (M = Mo, Re and W) by employing the ab-initio plane-wave method, based on the density functional theory (DFT). The exchange-correlation (XC) energy of electrons was treated using the Perdew–Burke–Ernzerhof parametrization. The ground-state electronic properties for different magnetic configurations were calculated. The formation enthalpies has been evaluated in order to determinate the stability of our compounds. The independent elastic constants and the related mechanical properties are investigated. The electronic structure calculation reveal the half-metallic ferrimagnets (FiM-HM) for all investigated compounds. The optical constants as the dielectric function, refractive index, optical reflectivity and absorption coefficient were calculated and discussed in detail. Therefore, our compounds are identified as potential candidates for spintronic applications and high performance electronic devices. - Highlights: • Based on the DFT calculation, the Pb{sub 2}FeMO{sub 6} (M = Mo, Re and W) compounds have been investigated. • The ground-state properties are predicted. • The mechanical properties reveals that these compounds are stable against any elastic deformations. • The electronic structures reveals the half-metallic ferrimagnets (FiM-HM) for all investigated compounds.

  8. Structure and stability of acrolein and allyl alcohol networks on Ag(111) from density functional theory based calculations with dispersion corrections

    Science.gov (United States)

    Ferullo, Ricardo M.; Branda, Maria Marta; Illas, Francesc

    2013-11-01

    The interaction of acrolein and allyl alcohol with the Ag(111) surface has been studied by means of periodic density functional theory based calculations including explicitly dispersion terms. Different coverage values have been explored going from isolated adsorbed molecules to isolated dimers, interacting dimers or ordered overlayers. The inclusion of the dispersion terms largely affects the calculated values of the adsorption energy and also the distance between adsorbed molecule and the metallic surface but much less the adsorbate-adsorbate interactions. Owing to the large dipole moment of acrolein, the present calculations predict that at high coverage this molecule forms a stable extensive two-dimensional network on the surface, caused by the alignment of the adsorbate dipoles. For the case of allyl alcohol, dimers and complex networks exhibit similar stability.

  9. Preliminary assessment of channel stability and bed-material transport in the Rogue River basin, southwestern Oregon

    Science.gov (United States)

    Jones, Krista L.; O'Connor, Jim E.; Keith, Mackenzie K.; Mangano, Joseph F.; Wallick, J. Rose

    2012-01-01

    This report summarizes a preliminary assessment of bed-material transport, vertical and lateral channel changes, and existing datasets for the Rogue River basin, which encompasses 13,390 square kilometers (km2) along the southwestern Oregon coast. This study, conducted to inform permitting decisions regarding instream gravel mining, revealed that: * The Rogue River in its lowermost 178.5 kilometers (km) alternates between confined and unconfined segments, and is predominately alluvial along its lowermost 44 km. The study area on the mainstem Rogue River can be divided into five reaches based on topography, hydrology, and tidal influence. The largely confined, active channel flows over bedrock and coarse bed material composed chiefly of boulders and cobbles in the Grants Pass (river kilometers [RKM] 178.5-152.8), Merlin (RKM 152.8-132.7), and Galice Reaches (RKM 132.7-43.9). Within these confined reaches, the channel contains few bars and has stable planforms except for locally wider segments such as the Brushy Chutes area in the Merlin Reach. Conversely, the active channel flows over predominately alluvial material and contains nearly continuous gravel bars in the Lobster Creek Reach (RKM 43.9-6.7). The channel in the Tidal Reach (RKM 6.7-0) is also alluvial, but tidally affected and unconfined until RKM 2. The Lobster Creek and Tidal Reaches contain some of the most extensive bar deposits within the Rogue River study area. * For the 56.6-km-long segment of the Applegate River included in this study, the river was divided into two reaches based on topography. In the Upper Applegate River Reach (RKM 56.6-41.6), the confined, active channel flows over alluvium and bedrock and has few bars. In the Lower Applegate River Reach (RKM 41.6-0), the active channel alternates between confined and unconfined segments, flows predominantly over alluvium, shifts laterally in unconfined sections, and contains more numerous and larger bars. * The 6.5-km segment of the lower

  10. Failure of the Hume-Rothery stabilization mechanism in the Ag5Li8 gamma-brass studied by first-principles FLAPW electronic structure calculations

    International Nuclear Information System (INIS)

    Mizutani, U; Asahi, R; Noritake, T; Sato, H; Takeuchi, T

    2008-01-01

    The first-principles FLAPW (full potential linearized augmented plane wave) electronic structure calculations were performed for the Ag 5 Li 8 gamma-brass, which contains 52 atoms in a unit cell and has been known for many years as one of the most structurally complex alloy phases. The calculations were also made for its neighboring phase AgLi B2 compound. The main objective in the present work is to examine if the Ag 5 Li 8 gamma-brass is stabilized at the particular electrons per atom ratio e/a = 21/13 in the same way as some other gamma-brasses like Cu 5 Zn 8 and Cu 9 Al 4 , obeying the Hume-Rothery electron concentration rule. For this purpose, the e/a value for the Ag 5 Li 8 gamma-brass as well as the AgLi B2 compound was first determined by means of the FLAPW-Fourier method we have developed. It proved that both the gamma-brass and the B2 compound possess an e/a value equal to unity instead of 21/13. Moreover, we could demonstrate why the Hume-Rothery stabilization mechanism fails for the Ag 5 Li 8 gamma-brass and proposed a new stability mechanism, in which the unique gamma-brass structure can effectively lower the band-structure energy by forming heavily populated bonding states near the bottom of the Ag-4d band

  11. SU-C-204-06: Monte Carlo Dose Calculation for Kilovoltage X-Ray-Psoralen Activated Cancer Therapy (X-PACT): Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    Mein, S [Duke University Medical Physics Graduate Program (United States); Gunasingha, R [Department of Radiation Safety, Duke University Medical Center (United States); Nolan, M [Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University (United States); Oldham, M; Adamson, J [Department of Radiation Oncology, Duke University Medical Center (United States)

    2016-06-15

    Purpose: X-PACT is an experimental cancer therapy where kV x-rays are used to photo-activate anti-cancer therapeutics through phosphor intermediaries (phosphors that absorb x-rays and re-radiate as UV light). Clinical trials in pet dogs are currently underway (NC State College of Veterinary Medicine) and an essential component is the ability to model the kV dose in these dogs. Here we report the commissioning and characterization of a Monte Carlo (MC) treatment planning simulation tool to calculate X-PACT radiation doses in canine trials. Methods: FLUKA multi-particle MC simulation package was used to simulate a standard X-PACT radiation treatment beam of 80kVp with the Varian OBI x-ray source geometry. The beam quality was verified by comparing measured and simulated attenuation of the beam by various thicknesses of aluminum (2–4.6 mm) under narrow beam conditions (HVL). The beam parameters at commissioning were then corroborated using MC, characterized and verified with empirically collected commissioning data, including: percent depth dose curves (PDD), back-scatter factors (BSF), collimator scatter factor(s), and heel effect, etc. All simulations were conducted for N=30M histories at M=100 iterations. Results: HVL and PDD simulation data agreed with an average percent error of 2.42%±0.33 and 6.03%±1.58, respectively. The mean square error (MSE) values for HVL and PDD (0.07% and 0.50%) were low, as expected; however, longer simulations are required to validate convergence to the expected values. Qualitatively, pre- and post-filtration source spectra matched well with 80kVp references generated via SPEKTR software. Further validation of commissioning data simulation is underway in preparation for first-time 3D dose calculations with canine CBCT data. Conclusion: We have prepared a Monte Carlo simulation capable of accurate dose calculation for use with ongoing X-PACT canine clinical trials. Preliminary results show good agreement with measured data and hold

  12. A Simplified Solution for Calculating the Phreatic Line and Slope Stability during a Sudden Drawdown of the Reservoir Water Level

    Directory of Open Access Journals (Sweden)

    Guanhua Sun

    2018-01-01

    Full Text Available On the basis of the Boussinesq unsteady seepage differential equation, a new simplified formula for the phreatic line of slopes under the condition of decreasing reservoir water level is derived by means of the Laplacian matrix and its inverse transform. In this context, the expression of normal stress on the slip surface under seepage forces is deduced, and a procedure for obtaining the safety factors under hydrodynamic forces is proposed. A case study of the Three Gorges Reservoir is used to analyze the influences of the water level, decreasing velocity and the permeability coefficient on slope stability.

  13. Neoclassical tearing modes in DIII-D and calculations of the stabilizing effects of localized electron cyclotron current drive

    International Nuclear Information System (INIS)

    Prater, R.; La Haye, R. J.; Lin-Liu, Y. R.; Lohr, J.; Perkins, F. W.; Bernabei, S.; Wong, K.-L.; Harvey, R. W.

    1999-01-01

    Neoclassical tearing modes are found to limit the achievable beta in many high performance discharges in DIII-D. Electron cyclotron current drive within the magnetic islands formed as the tearing mode grows has been proposed as a means of stabilizing these modes or reducing their amplitude, thereby increasing the beta limit by a factor around 1.5. Some experimental success has been obtained previously on Asdex-U. Here we examine the parameter range in DIII-D in which this effect can best be studied

  14. Vanillin and isovanillin: Comparative vibrational spectroscopic studies, conformational stability and NLO properties by density functional theory calculations

    Science.gov (United States)

    Balachandran, V.; Parimala, K.

    This study is a comparative analysis of FT-IR and FT-Raman spectra of vanillin (3-methoxy-4-hydroxybenzaldehyde) and isovanillin (3-hydroxy-4-methoxybenzaldehyde). The molecular structure, vibrational wavenumbers, infrared intensities, Raman scattering activities were calculated for both molecules using the B3LYP density functional theory (DFT) with the standard 6-311++G∗∗ basis set. The computed values of frequencies are scaled using multiple scaling factors to yield good coherence with the observed values. The calculated harmonic vibrational frequencies are compared with experimental FT-IR and FT-Raman spectra. The geometrical parameters and total energies of vanillin and isovanillin were obtained for all the eight conformers (a-h) from DFT/B3LYP method with 6-311++G∗∗ basis set. The computational results identified the most stable conformer of vanillin and isovanillin as in the "a" form. Non-linear properties such as electric dipole moment (μ), polarizability (α), and hyperpolarizability (β) values of the investigated molecules have been computed using B3LYP quantum chemical calculation. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecules.

  15. First -principles calculations of the crystal structure, electronic structure, and thermodynamic stability of Be(BH4)2

    NARCIS (Netherlands)

    van Setten, Michiel J.; de Wijs, Gilles A.; Brocks, G.

    2008-01-01

    Alanates and boranates are intensively studied because of their potential use as hydrogen storage materials. In this paper, we present a first-principles study of the electronic structure and the energetics of beryllium boranate BeBH42. From total energy calculations, we show that—in contrast to the

  16. Experimental and Theoretical Investigations on the Validity of Geometrical Optics Model for Calculating the Stability of Optical Traps

    NARCIS (Netherlands)

    Bakker schut, T.C.; Bakker Schut, Tom C.; Hesselink, Gerlo; Hesselink, Gerlo; de Grooth, B.G.; Greve, Jan

    1991-01-01

    We have developed a computer program based on the geometrical optics approach proposed by Roosen to calculate the forces on dielectric spheres in focused laser beams. We have explicitly taken into account the polarization of the laser light and thd divergence of the laser beam. The model can be used

  17. DFT-GIAO calculation of properties of {sup 19}F NMR and stability study of environmentally relevant perfluoroalkylsulfonamides (PFASAmide)

    Energy Technology Data Exchange (ETDEWEB)

    Mejia-Urueta, Rafael; Mestre-Quintero, Kleyber; Vivas-Reyes, Ricardo, E-mail: rvivasr@unicartagena.edu.co [Grupo de Quimica Cuantica y Teorica, Facultad de Ciencias Exactas y Naturales, Universidad de Cartagena, Cartagena (Colombia)

    2011-09-15

    Perfluorinated organic compounds (POCs), such as perfluorooctanesulfonate (PFOS) and perfluoroalkylsulfonamide (PFASA) are compounds that have recently attracted considerable attention worldwide because of its high persistence and wide distribution in the environment. Among the spectroscopic methods used to study the PFASA, {sup 19}F nuclear magnetic resonance (NMR {sup 19}F) is very effective, due to its ability to determine concentrations of PFASA in biological samples and measure pollution in water samples. For this reason, a theoretical study of the properties of {sup 19}F NMR was performed. In this study we have determined the shielding constant ({sigma}) for different fluorine nucleus of the 18 molecules under study, using density functional theory (DFT) and GIAO method with the B3PW91/6-31+G(d,p) level of calculation. The {sigma} calculations were made at vacuum and in presence of a solvent. The values of chemical shifts ({delta}), were also calculated in a different level of theory. The best results were obtained with the level of calculation DFT-GIAO/B3PW91/6-31+G(d,p) by considering the solvent such as dimethylsulfoxide (DMSO), chloroform (CHCl{sub 3}), acetone (CH{sub 3}COCH{sub 3}) and methanol (CH{sup 3}OH). The results were interpreted in terms of calculated hardness at DFT/B3PW91/6-31+G(d, p) level. The behaviour of the hardness was higher in the molecules of four carbons PFASA than eight carbons. This explain theoretically resistance of four carbons PFAS to be transformed into perfluorobutanesulfonate (PFBS). (author)

  18. DFT-GIAO calculation of properties of 19F NMR and stability study of environmentally relevant perfluoroalkylsulfonamides (PFASAmide)

    International Nuclear Information System (INIS)

    Mejia-Urueta, Rafael; Mestre-Quintero, Kleyber; Vivas-Reyes, Ricardo

    2011-01-01

    Perfluorinated organic compounds (POCs), such as perfluorooctanesulfonate (PFOS) and perfluoroalkylsulfonamide (PFASA) are compounds that have recently attracted considerable attention worldwide because of its high persistence and wide distribution in the environment. Among the spectroscopic methods used to study the PFASA, 19 F nuclear magnetic resonance (NMR 19 F) is very effective, due to its ability to determine concentrations of PFASA in biological samples and measure pollution in water samples. For this reason, a theoretical study of the properties of 19 F NMR was performed. In this study we have determined the shielding constant (σ) for different fluorine nucleus of the 18 molecules under study, using density functional theory (DFT) and GIAO method with the B3PW91/6-31+G(d,p) level of calculation. The σ calculations were made at vacuum and in presence of a solvent. The values of chemical shifts (δ), were also calculated in a different level of theory. The best results were obtained with the level of calculation DFT-GIAO/B3PW91/6-31+G(d,p) by considering the solvent such as dimethylsulfoxide (DMSO), chloroform (CHCl 3 ), acetone (CH 3 COCH 3 ) and methanol (CH 3 OH). The results were interpreted in terms of calculated hardness at DFT/B3PW91/6-31+G(d, p) level. The behaviour of the hardness was higher in the molecules of four carbons PFASA than eight carbons. This explain theoretically resistance of four carbons PFAS to be transformed into perfluorobutanesulfonate (PFBS). (author)

  19. Towards the prediction of multiple necking during dynamic extension of round bar: linear stability approach versus finite element calculations

    International Nuclear Information System (INIS)

    Maï, S El; Petit, J; Mercier, S; Molinari, A

    2014-01-01

    The fragmentation of structures subject to dynamic conditions is a matter of interest for civil industries as well as for Defence institutions. Dynamic expansions of structures, such as cylinders or rings, have been performed to obtain crucial information on fragment distributions. Many authors have proposed to capture by FEA the experimental distribution of fragment size by introducing in the FE model a perturbation. Stability and bifurcation analyses have also been proposed to describe the evolution of the perturbation growth rate. In the proposed contribution, the multiple necking of a round bar in dynamic tensile loading is analysed by the FE method. A perturbation on the initial flow stress is introduced in the numerical model to trigger instabilities. The onset time and the dominant mode of necking have been characterized precisely and showed power law evolutions, with the loading velocities and moderately with the amplitudes and the cell sizes of the perturbations. In the second part of the paper, the development of linear stability analysis and the use of salient criteria in terms of the growth rate of perturbations enabled comparisons with the numerical results. A good correlation in terms of onset time of instabilities and of number of necks is shown.

  20. A preliminary study of thermo-mechanical stability of carbon S-phase formed in austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei; Chiu, Yu Long; Dong, Hanshan, E-mail: wsgddf@hotmail.com [School of Metallurgy and Materials, College of Physical and Engineering Sciences, The University of Birmingham, Birmingham (United Kingdom)

    2010-07-01

    Carbon S-phase was generated in the surface of AISI316 austenitic stainless steel by plasma carburising at 500°C for 10h in a gas mixture of 1.5%CH4 and 98.5%H{sub 2}. The thermo-mechanical stability of the carbon S-phase was studied by stressing the 'dog-bone' tensile specimens in the range of 0-200MPa at temperatures ranging from 400 to 500°C for 100-150h. Post-test characterisation was conducted using XRD, SEM, TEM and micro-indentation. The experimental results demonstrate that when tested at a fix temperature the thickness of the carbon S-phase layer increased with the stress applied to the tensile specimens during the thermo-mechanical stability tests. This indicates that tensile stress promotes the diffusion of carbon in the carbon-S-phase. When stressed at 400°C the microstructure of the carbon S-phase was not affected by the stress level; however, when stressed at 450 and 500°C for 100MPa or above, the corrosion resistance of the carbon S-phase slightly deteriorated. The application of a tensile stress during annealing of S-phase layer can retard the deduction of its hardness. This is believed to be related to the early stage precipitation of carbides in the S-phase, which could be facilitated by the applied tensile stress during thermal annealing. (author)

  1. Dataset on the structure and thermodynamic and dynamic stability of Mo2ScAlC2 from experiments and first-principles calculations

    Directory of Open Access Journals (Sweden)

    Martin Dahlqvist

    2017-02-01

    Full Text Available The data presented in this paper are related to the research article entitled “Theoretical stability and materials synthesis of a chemically ordered MAX phase, Mo2ScAlC2, and its two-dimensional derivate Mo2ScC” (Meshkian et al. 2017 [1]. This paper describes theoretical phase stability calculations of the MAX phase alloy MoxSc3-xAlC2 (x=0, 1, 2, 3, including chemical disorder and out-of-plane order of Mo and Sc along with related phonon dispersion and Bader charges, and Rietveld refinement of Mo2ScAlC2. The data is made publicly available to enable critical or extended analyzes.

  2. Structural, phase stability, electronic, elastic properties and hardness of IrN{sub 2} and zinc blende IrN: First-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhaobo [Key Laboratory of Advanced Materials of Yunnan Province & Key Laboratory of Advanced Materials of Non-Ferrous and Precious Rare Metals Ministry of Education, Kunming University of Science and Technology, Kunming 650093 (China); Zhou, Xiaolong, E-mail: kmzxlong@163.com [Key Laboratory of Advanced Materials of Yunnan Province & Key Laboratory of Advanced Materials of Non-Ferrous and Precious Rare Metals Ministry of Education, Kunming University of Science and Technology, Kunming 650093 (China); Zhang, Kunhua [State Key Laboratory of Rare Precious Metals Comprehensive Utilization of New Technologies, Kunming Institute of Precious Metals, Kunming 650106 (China)

    2016-12-15

    First-principle calculations were performed to investigate the structural, phase stability, electronic, elastic properties and hardness of monoclinic structure IrN{sub 2} (m-IrN{sub 2}), orthorhombic structure IrN{sub 2} (o-IrN{sub 2}) and zinc blende structure IrN (ZB IrN). The results show us that only m-IrN{sub 2} is both thermodynamic and dynamic stability. The calculated band structure and density of states (DOS) curves indicate that o-IrN{sub 2} and ZB Ir-N compounds we calculated have metallic behavior while m-IrN{sub 2} has a small band gap of ~0.3 eV, and exist a common hybridization between Ir-5d and N-2p states, which forming covalent bonding between Ir and N atoms. The difference charge density reveals the electron transfer from Ir atom to N atom for three Ir-N compounds, which forming strong directional covalent bonds. Notable, a strong N-N bond appeared in m-IrN{sub 2} and o-IrN{sub 2}. The ratio of bulk to shear modulus (B/G) indicate that three Ir-N compounds we calculated are ductile, and ZB IrN possesses a better ductility than two types IrN{sub 2}. m-IrN{sub 2} has highest Debye temperature (736 K), illustrating it possesses strongest covalent bonding. The hardness of three Ir-N compounds were also calculated, and the results reveal that m-IrN{sub 2} (18.23 GPa) and o-IrN{sub 2} (18.02 GPa) are ultraincompressible while ZB IrN has a negative value, which may be attributed to phase transition at ca. 1.98 GPa.

  3. A preliminary assessment of financial stability, efficiency, health systems and health outcomes using performance-based contracts in Belize.

    Science.gov (United States)

    Bowser, Diana M; Figueroa, Ramon; Natiq, Laila; Okunogbe, Adeyemi

    2013-01-01

    Over the last 10 years, Belize has implemented a National Health Insurance (NHI) program that uses performance-based contracts with both public and private facilities to improve financial sustainability, efficiency and service provision. Data were collected at the facility, district and national levels in order to assess trends in financial sustainability, efficiency payments, year-end bonuses and health system and health outcomes. A difference-in-difference approach was used to assess the difference in technical efficiency between private and public facilities. The results show that per capita spending on services provided by the NHI program has decreased over the period 2006-2009 from BZ$177 to BZ$136. The private sector has achieved higher levels of technical efficiency, but lower percentages of efficiency and year-end bonus payments. Districts with contracts through the NHI program showed greater improvements in facility births, nurse density, reducing maternal mortality, diabetes deaths and morbidity from bronchitis, emphysema and asthma than districts without contracts over the period 2006-2010. This preliminary assessment of Belize's pay-for-performance system provides some positive results, however further research is needed to use the lessons learned from Belize to implement similar reforms in other systems.

  4. Phase stability, electronic structure and equation of state of cubic TcN from first-principles calculations

    International Nuclear Information System (INIS)

    Song, T.; Ma, Q.; Sun, X.W.; Liu, Z.J.; Fu, Z.J.; Wei, X.P.; Wang, T.; Tian, J.H.

    2016-01-01

    The phase transition, electronic band structure, and equation of state (EOS) of cubic TcN are investigated by first-principles pseudopotential method based on density-functional theory. The calculated enthalpies show that TcN has a transformation between zincblende and rocksalt phases and the pressure determined by the relative enthalpy is 32 GPa. The calculated band structure indicates the metallic feature and it might make cubic TcN a better candidate for hard materials. Particular attention is paid to the predictions of volume, bulk modulus and its pressure derivative which play a central role in the formulation of approximate EOSs using the quasi-harmonic Debye model. - Highlights: • The phase transition pressure and electronic band structure for cubic TcN are determined. • Particular attention is paid to investigate the equation of state parameters for cubic TcN. • The thermodynamic properties up to 80 GPa and 3000 K are successfully predicted.

  5. Relation between calculated Lennard-Jones potential and thermal stability of Cu-based bulk metallic glasses

    International Nuclear Information System (INIS)

    Lin, T.; Bian, X.F.; Jiang, J.

    2006-01-01

    Two metallic bulk glasses, Cu 60 Zr 30 Ti 10 and Cu 47 Ti 33 Zr 11 Ni 8 Si 1 , with a diameter of 3 mm were prepared by copper mold casting method. Dilatometric measurement was carried out on the two glassy alloys to obtain information about the average nearest-neighbour distance r 0 and the effective depth of pair potential V 0 . By assuming a Lennard-Jones potential, r 0 and V 0 were calculated to be 0.28 nm and 0.16 eV for Cu 60 Zr 30 Ti 10 and 0.27 nm and 0.13 eV for Cu 47 Ti 33 Zr 11 Ni 8 Si 1 , respectively. It was found that the glassy alloy Cu 60 Zr 30 Ti 10 was more stable than Cu 47 Ti 33 Zr 11 Ni 8 Si 1 against heating from both experiment and calculation

  6. Neural-net based calculation of voltage dips at maximum angular swing in direct transient stability analysis [of power systems

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M [Inst. ' Nikola Tesla' , Belgrade (Yugoslavia); Sobajic, D J; Pao, Yohhan [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Electrical Engineering and Applied Physics Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Computer Engineering and Science AI WARE inc., Cleveland, OH (United States)

    1992-10-01

    In heavily stressed power systems, post-fault transient voltage dips can lead to undesired tripping of industrial drives and large induction motors. The lowest transient voltage dips occur when fault clearing times are less than critical ones. In this paper, we propose a new iterative analytical methodology to obtain more accurate estimates of voltage dips at maximum angular swing in direct transient stability analysis. We also propose and demonstrate the possibility of storing the results of these computations in the associative memory (AM) system, which exhibits remarkable generalization capabilities. Feature-based models stored in the AM can be utilized for fast and accurate prediction of the location, duration and the amount of the worst voltage dips, thereby avoiding the need and cost for lengthy time-domain simulations. Numerical results obtained using the example of the New England power system are presented to illustrate our approach. (Author)

  7. On the calculation of the structure of charge-stabilized colloidal dispersions using density-dependent potentials

    International Nuclear Information System (INIS)

    Castañeda-Priego, R; Lobaskin, V; Mixteco-Sánchez, J C; Rojas-Ochoa, L F; Linse, P

    2012-01-01

    The structure of charge-stabilized colloidal dispersions has been studied through a one-component model using a Yukawa potential with density-dependent parameters examined with integral equation theory and Monte Carlo simulations. Partial thermodynamic consistency was guaranteed by considering the osmotic pressure of the dispersion from the approximate mean-field renormalized jellium and Poisson-Boltzmann cell models. The colloidal structures could be accurately described by the Ornstein-Zernike equation with the Rogers-Young closure by using the osmotic pressure from the renormalized jellium model. Although we explicitly show that the correct effective pair-potential obtained from the inverse Monte Carlo method deviates from the Yukawa shape, the osmotic pressure constraint allows us to have a good description of the colloidal structure without losing information on the system thermodynamics. Our findings are corroborated by primitive model simulations of salt-free colloidal dispersions. (paper)

  8. Stability analysis of the Backward Euler time discretization for the pin-resolved transport transient reactor calculation

    International Nuclear Information System (INIS)

    Zhu, Ang; Xu, Yunlin; Downar, Thomas

    2016-01-01

    Three-dimensional, full core transport modeling with pin-resolved detail for reactor dynamic simulation is important for some multi-physics reactor applications. However, it can be computationally intensive due to the difficulty in maintaining accuracy while minimizing the number of time steps. A recently proposed Transient Multi-Level (TML) methodology overcomes this difficulty by use multi-level transient solvers to capture the physical phenomenal in different time domains and thus maximize the numerical accuracy and computational efficiency. One major problem with the TML method is the negative flux/precursor number density generated using large time steps for the MOC solver, which is due to the Backward Euler discretization scheme. In this paper, the stability issue of Backward Euler discretization is first investigated using the Point Kinetics Equations (PKEs), and the predicted maximum allowed time step for SPERT test 60 case is shown to be less than 10 ms. To overcome this difficulty, linear and exponential transformations are investigated using the PKEs. The linear transformation is shown to increase the maximum time step by a factor of 2, and the exponential transformation is shown to increase the maximum time step by a factor of 5, as well as provide unconditionally stability above a specified threshold. The two sets of transformations are then applied to TML scheme in the MPACT code, and the numerical results presented show good agreement for standard, linear transformed, and exponential transformed maximum time step between the PKEs model and the MPACT whole core transport solution for three different cases, including a pin cell case, a 3D SPERT assembly case and a row of assemblies (“striped assembly case”) from the SPERT model. Finally, the successful whole transient execution of the stripe assembly case shows the ability of the exponential transformation method to use 10 ms and 20 ms time steps, which all failed using the standard method.

  9. Stability and mobility of Cu-vacancy clusters in Fe-Cu alloys: A computational study based on the use of artificial neural networks for energy barrier calculations

    International Nuclear Information System (INIS)

    Pascuet, M.I.; Castin, N.; Becquart, C.S.; Malerba, L.

    2011-01-01

    An atomistic kinetic Monte Carlo (AKMC) method has been applied to study the stability and mobility of copper-vacancy clusters in Fe. This information, which cannot be obtained directly from experimental measurements, is needed to parameterise models describing the nanostructure evolution under irradiation of Fe alloys (e.g. model alloys for reactor pressure vessel steels). The physical reliability of the AKMC method has been improved by employing artificial intelligence techniques for the regression of the activation energies required by the model as input. These energies are calculated allowing for the effects of local chemistry and relaxation, using an interatomic potential fitted to reproduce them as accurately as possible and the nudged-elastic-band method. The model validation was based on comparison with available ab initio calculations for verification of the used cohesive model, as well as with other models and theories.

  10. Stability and mobility of Cu-vacancy clusters in Fe-Cu alloys: A computational study based on the use of artificial neural networks for energy barrier calculations

    Science.gov (United States)

    Pascuet, M. I.; Castin, N.; Becquart, C. S.; Malerba, L.

    2011-05-01

    An atomistic kinetic Monte Carlo (AKMC) method has been applied to study the stability and mobility of copper-vacancy clusters in Fe. This information, which cannot be obtained directly from experimental measurements, is needed to parameterise models describing the nanostructure evolution under irradiation of Fe alloys (e.g. model alloys for reactor pressure vessel steels). The physical reliability of the AKMC method has been improved by employing artificial intelligence techniques for the regression of the activation energies required by the model as input. These energies are calculated allowing for the effects of local chemistry and relaxation, using an interatomic potential fitted to reproduce them as accurately as possible and the nudged-elastic-band method. The model validation was based on comparison with available ab initio calculations for verification of the used cohesive model, as well as with other models and theories.

  11. A preliminary study of factors affecting the calibration stability of the iridium versus iridium-40 percent rhodium thermocouple

    Science.gov (United States)

    Ahmed, Shaffiq; Germain, Edward F.; Daryabeigi, Kamran; Alderfer, David W.; Wright, Robert E.

    1987-01-01

    An iridium versus iridium-40% rhodium thermocouple was studied. Problems associated with the use of this thermocouple for high temperature applications (up to 2000 C) were investigated. The metallurgical studies included X-ray, macroscopic, resistance, and metallographic studies. The thermocouples in the as-received condition from the manufacturer revealed large amounts of internal stress caused by cold working during manufacturing. The thermocouples also contained a large amount of inhomogeneities and segregations. No phase transformations were observed in the alloy up to 1100 C. It was found that annealing the thermocouple at 1800 C for two hours, and then at 1400 C for 2 to 3 hours yielded a fine grain structure, relieving some of the strains, and making the wire more ductile. It was also found that the above annealing procedure stabilized the thermal emf behavior of the thermocouple for application below 1800 C (an improvement from + or - 1% to + or - 0.02% within the range of the test parameters used).

  12. Stabilization of lead (Pb) and zinc (Zn) in contaminated rice paddy soil using starfish: A preliminary study.

    Science.gov (United States)

    Moon, Deok Hyun; Hwang, Inseong; Koutsospyros, Agamemnon; Cheong, Kyung Hoon; Ok, Yong Sik; Ji, Won Hyun; Park, Jeong-Hun

    2018-05-01

    Lead (Pb) and zinc (Zn) contaminated rice paddy soil was stabilized using natural (NSF) and calcined starfish (CSF). Contaminated soil was treated with NSF in the range of 0-10 wt% and CSF in the range of 0-5 wt% and cured for 28 days. Toxicity characteristic leaching procedure (TCLP) test was used to evaluate effectiveness of starfish treatment. Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) analyses were conducted to investigate the mechanism responsible for effective immobilization of Pb and Zn. Experimental results suggest that NSF and CSF treatments effectively immobilize Pb and Zn in treated rice paddy soil. TCLP levels for Pb and Zn were reduced with increasing NSF and CSF dosage. Comparison of the two treatment methods reveals that CSF treatment is more effective than NSF treatment. Leachability of the two metals is reduced approximately 58% for Pb and 51% for Zn, upon 10 wt% NSF treatment. More pronounced leachability reductions, 93% for Pb and 76% for Zn, are achieved upon treatment with 5 wt% CSF. Sequential extraction results reveal that NSF and CSF treatments of contaminated soil generated decrease in exchangeable/weak acid Pb and Zn soluble fractions, and increase of residual Pb and Zn fractions. Results for the SEM-EDX sample treated with 5 wt% CSF indicate that effective Pb and Zn immobilization is most probably associated with calcium silicate hydrates (CSHs) and calcium aluminum hydrates (CAHs). Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Structural stability of diffusion barriers in thermoelectric SbTe: From first-principles calculations to experimental results

    International Nuclear Information System (INIS)

    Hsu, Hsiao-Hsuan; Cheng, Chun-Hu; Chiou, Shan-Haw; Huang, Chiung-Hui; Liu, Chia-Mei; Lin, Yu-Li; Chao, Wen-Hsuan; Yang, Ping-Hsing; Chang, Chun-Yen; Cheng, Chin-Pao

    2014-01-01

    Highlights: • The diffusion behavior was originated from high-vapor-pressure Te atom. • Te out-diffusion is main driving force to cause inter-diffusion effect. • Mid-band Ta and TaN with favored ohmic-like contact showed small diffusion tail. • Strong Ta-N bonding and high total energy suppressed interfacial layer formation. -- Abstract: This study involved developing robust diffusion barrier for n-type antimony telluride (SbTe) thermoelectric devices. Compared to conventional Ni barrier, the mid-band metals of Ta and TaN with favored ohmic-like contact exhibited smaller diffusion tail because of structurally stable interface on SbTe, which have been supported by first-principles calculations and demonstrated by experimental results. Furthermore, the TaN barrier has strong ionic Ta–N bonding and a high total energy of −4.7 eV/atom that could effectively suppress the formation of SbTe-compounds interfacial layer

  14. Effects of surface stability on the morphological transformation of metals and metal oxides as investigated by first-principles calculations.

    Science.gov (United States)

    Andrés, Juan; Gracia, Lourdes; Gouveia, Amanda Fernandes; Ferrer, Mateus Meneghetti; Longo, Elson

    2015-10-09

    Morphology is a key property of materials. Owing to their precise structure and morphology, crystals and nanocrystals provide excellent model systems for joint experimental and theoretical investigations into surface-related properties. Faceted polyhedral crystals and nanocrystals expose well-defined crystallographic planes depending on the synthesis method, which allow for thoughtful investigations into structure-reactivity relationships under practical conditions. This feature article introduces recent work, based on the combined use of experimental findings and first-principles calculations, to provide deeper knowledge of the electronic, structural, and energetic properties controlling the morphology and the transformation mechanisms of different metals and metal oxides: Ag, anatase TiO2, BaZrO3, and α-Ag2WO4. According to the Wulff theorem, the equilibrium shapes of these systems are obtained from the values of their respective surface energies. These investigations are useful to gain further understanding of how to achieve morphological control of complex three-dimensional crystals by tuning the ratio of the surface energy values of the different facets. This strategy allows the prediction of possible morphologies for a crystal and/or nanocrystal by controlling the relative values of surface energies.

  15. Biota Modeling in EPA's Preliminary Remediation Goal and Dose Compliance Concentration Calculators for Use in EPA Superfund Risk Assessment: Explanation of Intake Rate Derivation, Transfer Factor Compilation, and Mass Loading Factor Sources

    Energy Technology Data Exchange (ETDEWEB)

    Manning, Karessa L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dolislager, Fredrick G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bellamy, Michael B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-11-01

    The Preliminary Remediation Goal (PRG) and Dose Compliance Concentration (DCC) calculators are screening level tools that set forth Environmental Protection Agency's (EPA) recommended approaches, based upon currently available information with respect to risk assessment, for response actions at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites, commonly known as Superfund. The screening levels derived by the PRG and DCC calculators are used to identify isotopes contributing the highest risk and dose as well as establish preliminary remediation goals. Each calculator has a residential gardening scenario and subsistence farmer exposure scenarios that require modeling of the transfer of contaminants from soil and water into various types of biota (crops and animal products). New publications of human intake rates of biota; farm animal intakes of water, soil, and fodder; and soil to plant interactions require updates be implemented into the PRG and DCC exposure scenarios. Recent improvements have been made in the biota modeling for these calculators, including newly derived biota intake rates, more comprehensive soil mass loading factors (MLFs), and more comprehensive soil to tissue transfer factors (TFs) for animals and soil to plant transfer factors (BV's). New biota have been added in both the produce and animal products categories that greatly improve the accuracy and utility of the PRG and DCC calculators and encompass greater geographic diversity on a national and international scale.

  16. Biota Modeling in EPA's Preliminary Remediation Goal and Dose Compliance Concentration Calculators for Use in EPA Superfund Risk Assessment: Explanation of Intake Rate Derivation, Transfer Factor Compilation, and Mass Loading Factor Sources

    International Nuclear Information System (INIS)

    Manning, Karessa L.; Dolislager, Fredrick G.; Bellamy, Michael B.

    2016-01-01

    The Preliminary Remediation Goal (PRG) and Dose Compliance Concentration (DCC) calculators are screening level tools that set forth Environmental Protection Agency's (EPA) recommended approaches, based upon currently available information with respect to risk assessment, for response actions at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites, commonly known as Superfund. The screening levels derived by the PRG and DCC calculators are used to identify isotopes contributing the highest risk and dose as well as establish preliminary remediation goals. Each calculator has a residential gardening scenario and subsistence farmer exposure scenarios that require modeling of the transfer of contaminants from soil and water into various types of biota (crops and animal products). New publications of human intake rates of biota; farm animal intakes of water, soil, and fodder; and soil to plant interactions require updates be implemented into the PRG and DCC exposure scenarios. Recent improvements have been made in the biota modeling for these calculators, including newly derived biota intake rates, more comprehensive soil mass loading factors (MLFs), and more comprehensive soil to tissue transfer factors (TFs) for animals and soil to plant transfer factors (BV's). New biota have been added in both the produce and animal products categories that greatly improve the accuracy and utility of the PRG and DCC calculators and encompass greater geographic diversity on a national and international scale.

  17. Stability of Cd_1_–_xZn_xO_yS_1_–_y Quaternary Alloys Assessed with First-Principles Calculations

    International Nuclear Information System (INIS)

    Varley, Joel B.; He, Xiaoqing; Rockett, Angus; Lordi, Vincenzo

    2017-01-01

    One route to decreasing the absorption in CdS buffer layers in Cu(In,Ga)Se_2 and Cu_2ZnSn(S,Se)_4 thin-film photovoltaics is by alloying. Here we use first-principles calculations based on hybrid functionals to assess the energetics and stability of quaternary Cd, Zn, O, and S (Cd_1_–_xZn_xO_yS_1_–_y) alloys within a regular solution model. Our results identify that full miscibility of most Cd_1_–_xZn_xO_yS_1_–_y compositions and even binaries like Zn(O,S) is outside typical photovoltaic processing conditions. Finally, the results suggest that the tendency for phase separation of the oxysulfides may drive the nucleation of other phases such as sulfates that have been increasingly observed in oxygenated CdS and ZnS.

  18. The effect of small 4th element alloying additions on the calculated phase stability in the Fe-Cr-Ni system

    International Nuclear Information System (INIS)

    Watkin, J.S.

    1979-01-01

    Recent studies into the void swelling of Fe-Cr-Ni alloys have revealed that the magnitude of swelling depends upon alloy constitution and this together with the fact that minor element additions also play a major role in swelling necessitate a detailed knowledge of the influence of small 4th element additions on phase stability. In this paper the effects of additions of Nb, Ti, Al, Mo, Co and C to the Fe-Cr-Ni ternary are assessed by calculation. They confirm the ferritising tendencies of Nb, Ti and Al and the strong austenitising effect of C. Confirmation is also found for the scaling factors in the equivalent Ni and Cr equations in common usage and the paper presents Fe-Cr-Ni ternary sections at 400, 550 and 700 0 C modified for 1 at.% addition of each of the above elements. (orig.) [de

  19. Stability and mobility of self-interstitials and small interstitial clusters in α-iron: ab initio and empirical potential calculations

    International Nuclear Information System (INIS)

    Willaime, F.; Fu, C.C.; Marinica, M.C.; Dalla Torre, J.

    2005-01-01

    The stability and mobility of self-interstitials and small interstitial clusters, I n , in α-Fe is investigated by means of calculations performed in the framework of the density functional theory using the SIESTA code. The mono-, di- and tri-interstitials are shown to be made of (parallel) dumbbells and to migrate by nearest-neighbor translation-rotation jumps, according to Johnson's mechanism. The orientation of the dumbbells becomes energetically more favourable for I 5 and larger clusters. The performance of a semi-empirical potential recently developed for Fe, including ab initio self-interstitial data in the fitted properties, is evaluated over the present results. The superiority over previous semi-empirical potentials is confirmed. Finally the impact of the present results on the formation mechanism of loops, observed experimentally in α-Fe is discussed

  20. Theoretical calculation of pKa reveals an important role of Arg205 in the activity and stability of Streptomyces sp. N174 chitosanase.

    Science.gov (United States)

    Fukamizo, T; Juffer, A H; Vogel, H J; Honda, Y; Tremblay, H; Boucher, I; Neugebauer, W A; Brzezinski, R

    2000-08-18

    Based on the crystal structure of chitosanase from Streptomyces sp. N174, we have calculated theoretical pK(a) values of the ionizable groups of this protein using a combination of the boundary element method and continuum electrostatics. The pK(a) value obtained for Arg(205), which is located in the catalytic cleft, was abnormally high (>20.0), indicating that the guanidyl group may interact strongly with nearby charges. Chitosanases possessing mutations in this position (R205A, R205H, and R205Y), produced by Streptomyces lividans expression system, were found to have less than 0.3% of the activity of the wild type enzyme and to possess thermal stabilities 4-5 kcal/mol lower than that of the wild type protein. In the crystal structure, the Arg(205) side chain is in close proximity to the Asp(145) side chain (theoretical pK(a), -1.6), which is in turn close to the Arg(190) side chain (theoretical pK(a), 17.7). These theoretical pK(a) values are abnormal, suggesting that both of these residues may participate in the Arg(205) interaction network. Activity and stability experiments using Asp(145)- and Arg(190)-mutated chitosanases (D145A and R190A) provide experimental data supporting the hypothesis derived from the theoretical pK(a) data and prompt the conclusion that Arg(205) forms a strong interaction network with Asp(145) and Arg(190) that stabilizes the catalytic cleft.

  1. Revision to the humidity correction equation in the calculation formulae of the air refractive index based on a phase step interferometer with three frequency-stabilized lasers

    International Nuclear Information System (INIS)

    Chen, Qianghua; Zhang, Mengce; Liu, Shuaijie; He, Yongxi; Luo, Huifu; Luo, Jun; Lv, Weiwei

    2016-01-01

    At present the formulae proposed by G Boensch and E Potulski in 1998 (Boensch and Potulski 1998 Metrologia 35 133–9) are mostly used to calculate the air refractive index. However, the humidity correction equation in the formulae is derived by using the light source of a Cd lamp whose light frequency stability is poor and at a narrow temperature range, around 20 °C. So it is no longer suitable in present optical precision measurements. To solve this problem, we propose a refractive index measurement system based on phase step interferometer with three frequency stabilized lasers (532 nm, 633 nm, 780 nm), corrected coefficients of the humidity are measured and a corresponding revised humidity correction equation is acquired. Meanwhile, the application temperature range is extended from 14.6 °C to 25.0 °C. The experiment comparison results at the temperature of 22.2–23.2 °C show the accuracy by the presented equation is better than that of Boensch and Potulski. (paper)

  2. Calculations of shape and stability of menisci in Czochralski growth with tables to determine meniscus heights, maximum heights and capillary constants

    International Nuclear Information System (INIS)

    Uelhoff, W.; Mika, K.

    1975-05-01

    The shape and stability of menisci occurring during Czochralski growth have been studied by means of numerical methods for the case of the free surface. The existence of minimal joining angles is shown, beyond which the growing crystal will separate from the melt. The dependence of the interface height on the joining angle for different crystal diameters was calculated. The maximum stable heights and the corresponding joining angles were determined as a function of crystal diameter. A method for measuring the capillary constant of the melt during Czochralski growth is proposed. The results are compared with known analytical approximations. Limitations of the applications caused by a finite crucible radius or low g values are pointed out. For practical use the following functions have been tabulated: 1) meniscus height in dependence on joining angle and crystal radius, 2) the radius-height-ratio in dependence on radius and angle for the calculation of the capillary constant, 3) the maximum stable height and the corresponding growth angle as a function of crystal radius. (orig.) [de

  3. Relative device stability of anterior versus axillary needle decompression for tension pneumothorax during casualty movement: Preliminary analysis of a human cadaver model.

    Science.gov (United States)

    Leatherman, Matthew L; Held, Jenny M; Fluke, Laura M; McEvoy, Christian S; Inaba, Kenji; Grabo, Daniel; Martin, Matthew J; Earley, Angela S; Ricca, Robert L; Polk, Travis M

    2017-07-01

    Tension pneumothorax (tPTX) remains a significant cause of potentially preventable death in military and civilian settings. The current prehospital standard of care for tPTX is immediate decompression with a 14-gauge 8-cm angiocatheter; however, failure rates may be as high as 17% to 60%. Alternative devices, such as 10-gauge angiocatheter, modified Veress needle, and laparoscopic trocar, have shown to be potentially more effective in animal models; however, little is known about the relative insertional safety or mechanical stability during casualty movement. Seven soft-embalmed cadavers were intubated and mechanically ventilated. Chest wall thickness was measured at the second intercostal space at the midclavicular line (2MCL) and the fifth intercostal space along the anterior axillary line (5AAL). CO2 insufflation created a PTX, and needle decompression was then performed with a randomized device. Insertional depth was measured between hub and skin before and after simulated casualty transport. Thoracoscopy was used to evaluate for intrapleural placement and/or injury during insertion and after movement. Cadaver demographics, device displacement, device dislodgment, and injuries were recorded. Three decompressions were performed at each site (2MCL/5AAL), totaling 12 events per cadaver. Eighty-four decompressions were performed. Average cadaver age was 59 years, and body mass index was 24 kg/m. The CWT varied between cadavers because of subcutaneous emphysema, but the average was 39 mm at the 2MCL and 31 mm at the 5AAL. Following movement, the 2MCL site was more likely to become dislodged than the 5AAL (67% vs. 17%, p = 0.001). Median displacement also differed between 2MCL and 5AAL (23 vs. 2 mm, p = 0.001). No significant differences were noted in dislodgement or displacement between devices. Five minor lung injuries were noted at the 5AAL position. Preliminary results from this human cadaver study suggest the 5AAL position is a more stable and reliable location

  4. Jet stability in the lithium fall reactor

    International Nuclear Information System (INIS)

    Kang, S.W.

    1978-01-01

    A preliminary analysis has been made of the various hydrodynamic aspects involved in the stability of a liquid-lithium jet in a laser-fusion reactor, which comprises a part of LLL's laser fusion power-generation concept. Various physical factors that may affect the jet breakup are delineated, and some approximate calculations are performed to determine their relative influences. Areas of uncertainty are pointed out, along with plans for experimental verification or further theoretical analysis

  5. Validation of an online risk calculator for the prediction of anastomotic leak after colon cancer surgery and preliminary exploration of artificial intelligence-based analytics.

    Science.gov (United States)

    Sammour, T; Cohen, L; Karunatillake, A I; Lewis, M; Lawrence, M J; Hunter, A; Moore, J W; Thomas, M L

    2017-11-01

    Recently published data support the use of a web-based risk calculator ( www.anastomoticleak.com ) for the prediction of anastomotic leak after colectomy. The aim of this study was to externally validate this calculator on a larger dataset. Consecutive adult patients undergoing elective or emergency colectomy for colon cancer at a single institution over a 9-year period were identified using the Binational Colorectal Cancer Audit database. Patients with a rectosigmoid cancer, an R2 resection, or a diverting ostomy were excluded. The primary outcome was anastomotic leak within 90 days as defined by previously published criteria. Area under receiver operating characteristic curve (AUROC) was derived and compared with that of the American College of Surgeons National Surgical Quality Improvement Program ® (ACS NSQIP) calculator and the colon leakage score (CLS) calculator for left colectomy. Commercially available artificial intelligence-based analytics software was used to further interrogate the prediction algorithm. A total of 626 patients were identified. Four hundred and fifty-six patients met the inclusion criteria, and 402 had complete data available for all the calculator variables (126 had a left colectomy). Laparoscopic surgery was performed in 39.6% and emergency surgery in 14.7%. The anastomotic leak rate was 7.2%, with 31.0% requiring reoperation. The anastomoticleak.com calculator was significantly predictive of leak and performed better than the ACS NSQIP calculator (AUROC 0.73 vs 0.58) and the CLS calculator (AUROC 0.96 vs 0.80) for left colectomy. Artificial intelligence-predictive analysis supported these findings and identified an improved prediction model. The anastomotic leak risk calculator is significantly predictive of anastomotic leak after colon cancer resection. Wider investigation of artificial intelligence-based analytics for risk prediction is warranted.

  6. Ionic ASi{sub 2}N{sub 3} (A=Li, Na, K and Rb) stabilized by the covalent Si–N bonding: First-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Huijun [College of Information Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Ren, Jiadong, E-mail: jdren@ysu.edu.cn [College of Information Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Wu, Lailei [Key Laboratory of Metastable Materials Science and Technology, College of Material Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Zhang, Jingwu, E-mail: zjw@ysu.edu.cn [Key Laboratory of Metastable Materials Science and Technology, College of Material Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2017-01-15

    The structural, elastic and electronic properties of LiSi{sub 2}N{sub 3} and its substitutions by Na, K and Rb were investigated through first-principles computations. The expansion of lattice parameters of ASi{sub 2}N{sub 3} from Li, Na, K to Rb is found to be determined by the bond angle of Si–N1–Si, which suggests a possible way to improve the lithium ionic conductivity by substitutions. ASi{sub 2}N{sub 3} (A=Li, Na, K and Rb) shows the similar elastic behaviors, while the electronic band gap gradually decreases from 5.1 to 3.4 eV from LiSi{sub 2}N{sub 3} to RbSi{sub 2}N{sub 3}. Interestingly, the analysis of electronic structure, crystal orbital Hamiltonian populations and Bader charges shows that the covalence of Si–N bonding is critical for the stability of ASi{sub 2}N{sub 3} phase. Among ASi{sub 2}N{sub 3} phases, there is a relatively high ionicity in NaSi{sub 2}N{sub 3}; the Si–N bond strength in [Si{sub 2}N{sub 3}]{sup −} net for KSi{sub 2}N{sub 3} and RbSi{sub 2}N{sub 3} is comparable to LiSi{sub 2}N{sub 3}, but stronger than NaSi{sub 2}N{sub 3}. - Graphic abstract: Universal trend of structural and electronic properties in alkaline metal silicon nitrides, ASi{sub 2}N{sub 3}, A=Li, Na, K and Rb. - Highlights: • Trend in structure, electronic and mechanical properties of ASi{sub 2}N{sub 3} (A=Li-Rb) were predicted. • Lattice expansion of ASi{sub 2}N{sub 3} induced by the bond angle of Si–N1–Si was found. • Calculated band gap decreases from 5.1 to 3.4 eV from LiSi{sub 2}N{sub 3} to RbSi{sub 2}N{sub 3}. • Covalent Si–N bonding is critical for the stability of ASi{sub 2}N{sub 3}.

  7. Preliminary results of the seventh three-dimensional AER dynamic benchmark problem calculation. Solution with DYN3D and RELAP5-3D codes

    International Nuclear Information System (INIS)

    Bencik, M.; Hadek, J.

    2011-01-01

    The paper gives a brief survey of the seventh three-dimensional AER dynamic benchmark calculation results received with the codes DYN3D and RELAP5-3D at Nuclear Research Institute Rez. This benchmark was defined at the twentieth AER Symposium in Hanassari (Finland). It is focused on investigation of transient behaviour in a WWER-440 nuclear power plant. Its initiating event is opening of the main isolation valve and re-connection of the loop with its main circulation pump in operation. The WWER-440 plant is at the end of the first fuel cycle and in hot full power conditions. Stationary and burnup calculations were performed with the code DYN3D. Transient calculation was made with the system code RELAP5-3D. The two-group homogenized cross sections library HELGD05 created by HELIOS code was used for the generation of reactor core neutronic parameters. The detailed six loops model of NPP Dukovany was adopted for the seventh AER dynamic benchmark purposes. The RELAP5-3D full core neutronic model was coupled with 49 core thermal-hydraulic channels and 8 reflector channels connected with the three-dimensional model of the reactor vessel. The detailed nodalization of reactor downcomer, lower and upper plenum was used. Mixing in lower and upper plenum was simulated. The first part of paper contains a brief characteristic of RELAP5-3D system code and a short description of NPP input deck and reactor core model. The second part shows the time dependencies of important global and local parameters. (Authors)

  8. Preliminary Calculation of the Energy Budget of the Radio Lines Orbital Method of Monitoring of Incidents caused by the Operator of the GLONASS system

    Directory of Open Access Journals (Sweden)

    Mikhail Yurievich Senatorov

    2013-12-01

    Full Text Available The calculation of the power transmitter onboard GLONASS satellites is submitted for the operation method of orbital monitoring of incidents caused by the system operator. Article is devoted to the description of actual ways of possible distribution of malwares such, as “Easter eggs”, client network applications (torrent-client and service of digital distribution. As the experiment description on distribution of malwares is provided in the simulated virtual network by means of service of digital distribution. Rules on safety of the user computers in a network are developed.

  9. Preliminary shielding calculation for the system of CyberKnife robotic radiosurgery; Calculo de blindagem preliminar para o sistema de radiocirurgia robotica CyberKnife

    Energy Technology Data Exchange (ETDEWEB)

    Toreti, Dalila; Xavier, Clarice; Moura, Fabio, E-mail: clarice.xavier@rem.ind.b, E-mail: fabio.moura@rem.ind.b [REM Industria e Comercio Ltda., Sao Paulo, SP (Brazil)

    2011-10-26

    The CyberKnife robotic system uses a manipulator with six grade of freedom for positioning a 6 MV Linac accelerator for treatment of lesions. This paper presents calculations for a standard room, with 200 cm of thickness walls primary, build for a CyberKnife system, and calculations for a room originally designed for a Linac conventional (with gantry), with secondary barriers of 107 cm thickness. After the realization of shielding for both rooms, the results shown that walls of standard room with 200 cm thickness are adequate for the secondary shield, and for a room with a conventional Linac, from all six evaluated points, two would require additional shielding of nine cm and four cm of concrete with 2.4 g/cubic cm. This shows that the CyberKnife system can be installed in a originally designed room for a conventional Linac with neither restrict nor any shielding, since no incidence of beams on the secondary barriers is existent

  10. Preliminary calculations of stress change of fuel pin using SiC/SiC composites for GFR with changing of thermal conductivity degradation by irradiation

    International Nuclear Information System (INIS)

    Lee, J. K.; Naganuma, M.

    2006-01-01

    Gas cooled Fast Reactor (GFR) is being researched as a candidate concept of Generation IV international Forum. As a main feature of GFR, it should be maintained high temperature and pressure of coolant gas for heat transfer efficiency. Such a demanding environment requires high-temperature-resistant structural materials distinguished from traditional steel material. Consequently, ceramics are promising candidate material of core components. Especially, Silicon Carbide fiber reinforced Silicon Carbide composites (SiC/SiC) have encouraging characteristics such as refractoriness, low activation and toughness. Application of new material to core components must be explained by the viewpoint of engineering validity. Therefore, present study surveyed that current report for mechanical strength and thermal conductivity of SiC/SiC composites. According to the reports, neutron irradiation environment degraded mechanical properties of SiC/SiC composites. To confirm applicability to core components, model of fuel pin using SiC/SiC composites was assumed with feasible mechanical properties. Furthermore, it was calculated and estimated that the stress caused by temperature variation of inner and outer side of assumed model of cladding tube. Stress was calculated by changing of input date such as thickness of cladding tube, temperature variation, thermal conductivity and linear power. In the range of this study, the most important factor was identified as degradation of thermal conductivity by irradiation. It caused a significant stress and limited a geometrical design of fuel pin. It was discussed that the differences of heat transfer between isotropic and anisotropic materials like a metal and composites. These results should be helpful not only to determine a design factor of core component but also to indicate an improvement direction of SiC/SiC composites. Through these work, reliability and safety of GFR will be increased

  11. Preliminary study on the differentiation between parapelvic cyst and hydronephrosis with non-calculous using only pre-contrast dual-energy spectral CT scans

    Science.gov (United States)

    Han, Dong; Ma, Guangming; Wei, Lequn; Ren, Chenglong; Zhou, Jieli; Shen, Chen

    2017-01-01

    Objective: To investigate the value of using the quantitative parameters from only the pre-contrast dual-energy spectral CT imaging for distinguishing between parapelvic cyst and hydronephrosis with non-calculous (HNC). Methods: This retrospective study was approved by the institutional review board. 28 patients with parapelvic cyst and 24 patients with HNC who underwent standard pre-contrast and multiphase contrast-enhanced dual-energy spectral CT imaging were retrospectively identified. The parapelvic cyst and HNC were identified using the contrast-enhanced scans, and their CT number in the 70-keV monochromatic images, effective atomic number (Zeff), iodine concentration (IC) and water concentration in the pre-contrast images were measured. The slope of the spectral curve (λ) was calculated. The difference in the measurements between parapelvic cyst and HNC was statistically analyzed using SPSS® v. 19.0 (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) statistical software. Receiver-operating characteristic analysis was performed to assess the diagnostic performance. Results: The CT numbers in the 70-keV images, Zeff and IC values were statistically different between parapelvic cyst and HNC (all p  0.05). Conclusion: The quantitative parameters obtained in the pre-contrast dual-energy spectral CT imaging may be used to differentiate between parapelvic cyst and HNC. Advances in knowledge: The pre-contrast dual-energy spectral CT scans may be used to screen parapelvic cysts for patients who are asymptomatic, thereby avoiding contrast-enhanced CT or CT urography examination for these patients to reduce ionizing radiation dose and contrast dose. PMID:28281789

  12. Preliminary assessment of channel stability and bed-material transport in the Tillamook Bay tributaries and Nehalem River basin, northwestern Oregon

    Science.gov (United States)

    Jones, Krista L.; Keith, Mackenzie K.; O'Connor, Jim E.; Mangano, Joseph F.; Wallick, J. Rose

    2012-01-01

    subject to incision and aggradation as well as lateral shifts in thalweg position and bank deposition and erosion. * In fluvial reaches, unit bar area declined a net 5.3-83.6 percent from 1939 to 2009. The documented reduction in bar area may be attributable to several factors, including vegetation establishment and stabilization of formerly active bar surfaces, lateral channel changes and resulting alterations in sediment deposition and erosion patterns, and streamflow and/or tide differences between photographs. Other factors that may be associated with the observed reduction in bar area but not assessed in this reconnaissance level study include changes in the sediment and hydrology regimes of these rivers over the analysis period. * In tidal reaches, unit bar area increased on the Tillamook and Nehalem Rivers (98.0 and 14.7 percent, respectively), but declined a net 24.2 to 83.1 percent in the other four tidal reaches. Net increases in bar area in the Tidal Tillamook and Nehalem Reaches were possibly attributable to tidal differences between the photographs as well as sediment deposition behind log booms and pile structures on the Tillamook River between 1939 and 1967. * The armoring ratio (ratio of the median grain sizes of a bar's surface and subsurface layers) was 1.6 at Lower Waldron Bar on the Miami River, tentatively indicating a relative balance between transport capacity and sediment supply at this location. Armoring ratios, however, ranged from 2.4 to 5.5 at sites on the Trask, Wilson, Kilchis, and Nehalem Rivers; these coarse armor layers probably reflect limited bed-material supply at these sites. * On the basis of mapping results, measured armoring ratios, and channel cross section surveys, preliminary conclusions are that the fluvial reaches on the Tillamook, Trask, Kilchis, and Nehalem Rivers are currently sediment supply-limited in terms of bed material - that is, the transport capacity of the channel generally exceeds the supply of bed material. The

  13. Use of computer graphics for calculation of stability constants of praseodymium tris-(1,1,1,2,2,3,3,5-octafluoro-5-trifluromethyl-4-oxo-8-phenyloctanedion-6,8) adduct with 4-picoline from the NMR spectroscopy data

    International Nuclear Information System (INIS)

    Buiklinskij, V.D.; Kuznetsova, S.L.; Kostyrina, T.V.; Panyushkina, V.T.

    1991-01-01

    Lanthanide shifting reagent (LSR) on the basis of β-diketone of asymmetric structure, containing heteroatom-oxygen in fluorinated radical, has been synthesized. Adduct formation of LSR synthesized with 4-picoline has been studied by the method of NMR spectroscopy. The composition of the adduct formed, being 1:2, is determined. Stability constant of the adduct considered is calculated by previously suggested method, which consists in taking into account of equilibrium concentrations of the substrate in two experiments. Possibilities of computer graphics for the evaluation of paramters of the mathematical model suggested are demonstrated. The values of stability stepped constants of the adduct are calculated: lg K 1 =3.4±0.1; lg K 2 =2.0±0.1

  14. Stability analysis of sharp-boundary Vlasov-fluid screw-pinch equilibria

    International Nuclear Information System (INIS)

    Lewis, H.R.; Turner, L.

    1975-01-01

    The Vlasov-fluid model is being used to study the linear stability of sharp-boundary screw pinches numerically. The numerical method appears to work well, and some preliminary results are reported. The sharp-boundary calculation is useful for gaining insight and for comparing with known MHD results. (auth)

  15. Preliminary Design of a LSA Aircraft Using Wind Tunnel Tests

    Directory of Open Access Journals (Sweden)

    Norbert ANGI

    2015-12-01

    Full Text Available This paper presents preliminary results concerning the design and aerodynamic calculations of a light sport aircraft (LSA. These were performed for a new lightweight, low cost, low fuel consumption and long-range aircraft. The design process was based on specific software tools as Advanced Aircraft Analysis (AAA, XFlr 5 aerodynamic and dynamic stability analysis, and Catia design, according to CS-LSA requirements. The calculations were accomplished by a series of tests performed in the wind tunnel in order to assess experimentally the aerodynamic characteristics of the airplane.

  16. Structures, stability, magnetic moments and growth strategies of the Fe_nN (n = 1–7) clusters: All-electron density functional theory calculations

    International Nuclear Information System (INIS)

    Li, Zhi; Zhao, Zhen

    2017-01-01

    The geometries, electronic properties, magnetic moments and growth strategies of the Fe_nN (n = 1–7) clusters are investigated using all-electron density functional theory. The results show that N doping significantly distorts the Fe_n clusters. Fe_4N and Fe_6N clusters are more stable structures than other considered Fe_nN clusters. Local peaks of HOMO-LUMO gap curve are found at n = 3, 7, implying that the chemical stability of the Fe_3N and Fe_7N clusters is higher. Fe_2N, Fe_4N and Fe_6N clusters have larger magnetic moments compared to other considered Fe_nN (n = 1–7) clusters. It can be seen that the Fe_5 clusters are easier to adsorb a Fe atom while the Fe_4 clusters are easier to adsorb a N atom. The considered Fe_mN clusters prefer to adsorb a Fe atom and larger Fe_mN clusters are easier to grow. - Highlights: • The structural stability of the Fe_4N and Fe_6N clusters is higher. • The chemical stability of the Fe_3N and Fe_7N clusters is higher. • Fe_5 clusters are easier to adsorb a Fe atom while Fe_4 clusters are easier to adsorb a N atom. • Fe_nN clusters prefer to adsorb a Fe atom.

  17. Remedial action plan and site design for stabilization of the inactive uranium mill tailings sites at Slick Rock, Colorado: Remedial Action Selection Report. Preliminary final

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    This proposed remedial action plan incorporates the results of detailed investigation of geologic, geomorphic, and seismic conditions at the proposed disposal site. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/waterborne materials to a permanent repository at the proposed Burro Canyon disposal cell. The proposed disposal site will be geomorphically stable. Seismic design parameters were developed for the geotechnical analyses of the proposed cell. Cell stability was analyzed to ensure long-term performance of the disposal cell in meeting design standards, including slope stability, settlement, and liquefaction potential. The proposed cell cover and erosion protection features were also analyzed and designed to protect the RRM (residual radioactive materials) against surface water and wind erosion. The location of the proposed cell precludes the need for permanent drainage or interceptor ditches. Rock to be used on the cell top-, side-, and toeslopes was sized to withstand probable maximum precipitation events.

  18. Differences in the Limits of Stability Between Older Rolling Walker Users and Older Single-Tip-Cane Users - A Preliminary Study.

    Science.gov (United States)

    Liu, Hao Howe; Quiben, Myles; Holmes, Clayton; Connors, Michael; Salem, Yasser

    To identify the differences in the limits of stability (LOS) between older rolling walker and single-tip-cane users. This was a matched paired t-test design with repeated measure. Eighteen older subjects were matched based on age, gender, and functional level. The subjects were assessed using the multidirectional reach test initially and 5-month later in four directions: forward, backward, leftward, and rightward. Initially, there were no differences between cane users and rolling walker users in the LOS in all directions. However, 5-month later, the cane users who held their canes in their right hand had significantly better stability in forward and rightward reach than the walker users (p walker users demonstrated significantly decreased functional reach in forward reach (p walker users in the forward direction and in the direction toward the side holding the cane. This study may provide guide for clinicians including nurses for selecting appropriate rehabilitative interventions for older adults using walkers and canes.

  19. Remedial Action Plan and Site Design for stabilization of the inactive Uranium Mill Tailings sites at Slick Rock, Colorado: Appendix C to Attachment 3, Calculations. Final

    International Nuclear Information System (INIS)

    1995-09-01

    This volume contains calculations for: Slick Rock processing sites background ground water quality; Slick Rock processing sites lysimeter water quality; Slick Rock processing sites on-site and downgradient ground water quality; Slick Rock disposal site background water quality; Burro Canyon disposal site, Slick Rock, Colorado, average hydraulic gradients and average liner ground water velocities in the upper, middle, and lower sandstone units of the Burro Canyon formation; Slick Rock--Burro Canyon disposal site, Burro Canyon pumping and slug tests--analyses; water balance and surface contours--Burro Canyon disposal cell; and analytical calculation of drawdown in a hypothetical well completed in the upper sandstone unit of the Burro Canyon formation

  20. Ajuste de Estabilizadores de Potencia en generadores utilizando el paquete Power Systems Analysis Toolbox PSAT; Setting of Power System Stabilizers based in PSAT free package calculations

    Directory of Open Access Journals (Sweden)

    Antonio A. Martínez García

    2015-04-01

    Full Text Available La regulación de la tensión es el modo más elemental de control de los Sistemas Eléctricos de Potencia que mejora la estabilidad y la estabilidad transitoria. La introducción de reguladores de tensión muy rápidos facilita la capacidad del sistema de generar acciones que conserven su estabilidad (incremento del torque sincronizante. No obstante, estos dispositivos disminuyen el amortiguamiento del sistema. La forma más económica de mejorar el amortiguamiento de las oscilaciones mecánicas de las unidades generadoras se logra con la adición de un control suplementario agregado en el sistema de excitación, que se conoce como estabilizador de potencia (PSS, por sus siglas en inglés Power System Stabilizer. En el presente trabajo se utilizan las posibilidades del paquete PSAT para seleccionar la mejor ubicación y ajustar PSS en un sistema longitudinal sencillo de dos áreas, similar al caso del Sistema Eléctrico de la República de Cuba. Normally, voltage regulation is the primary mode of control, which improves voltage and transient stability. The introduction of generator´s fast voltage regulators improves Electrical Power Systems ability to generate synchronizing torque to maintain stability. These control devices have a negative effect in damping system oscillations. Supplementary control in generator’s voltage regulators (PSS is the most economic solution to improve system damping. This supplementary control is obtained using power system dampers. PSAT abilities are used in order to obtain setting of this supplementary control in a simple longitudinal two areas system, similar to Cuban Electric Power System.

  1. Structures, stability, magnetic moments and growth strategies of the Fe{sub n}N (n = 1–7) clusters: All-electron density functional theory calculations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhi, E-mail: lizhi81723700@163.com [School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan, 114051 (China); Zhao, Zhen [School of Chemistry and Life Science, Anshan Normal University, Anshan, 114007 (China)

    2017-02-01

    The geometries, electronic properties, magnetic moments and growth strategies of the Fe{sub n}N (n = 1–7) clusters are investigated using all-electron density functional theory. The results show that N doping significantly distorts the Fe{sub n} clusters. Fe{sub 4}N and Fe{sub 6}N clusters are more stable structures than other considered Fe{sub n}N clusters. Local peaks of HOMO-LUMO gap curve are found at n = 3, 7, implying that the chemical stability of the Fe{sub 3}N and Fe{sub 7}N clusters is higher. Fe{sub 2}N, Fe{sub 4}N and Fe{sub 6}N clusters have larger magnetic moments compared to other considered Fe{sub n}N (n = 1–7) clusters. It can be seen that the Fe{sub 5} clusters are easier to adsorb a Fe atom while the Fe{sub 4} clusters are easier to adsorb a N atom. The considered Fe{sub m}N clusters prefer to adsorb a Fe atom and larger Fe{sub m}N clusters are easier to grow. - Highlights: • The structural stability of the Fe{sub 4}N and Fe{sub 6}N clusters is higher. • The chemical stability of the Fe{sub 3}N and Fe{sub 7}N clusters is higher. • Fe{sub 5} clusters are easier to adsorb a Fe atom while Fe{sub 4} clusters are easier to adsorb a N atom. • Fe{sub n}N clusters prefer to adsorb a Fe atom.

  2. Martensitic transformation and phase stability of In-doped Ni-Mn-Sn shape memory alloys from first-principles calculations

    International Nuclear Information System (INIS)

    Xiao, H. B.; Yang, C. P.; Wang, R. L.; Luo, X.; Marchenkov, V. V.

    2014-01-01

    The effect of the alloying element Indium (In) on the martensitic transition, magnetic properties, and phase stabilities of Ni 8 Mn 6 Sn 2−x In x shape memory alloys has been investigated using the first-principles pseudopotential plane-wave method based on density functional theory. The energy difference between the austenitic and martensitic phases was found to increase with increasing In content, which implies an enhancement of the martensitic phase transition temperature (T M ). Moreover, the formation energy results indicate that In-doping increases the relative stability of Ni 8 Mn 6 Sn 2−x In x both in austenite and martensite. This results from a reduction in density of states near the Fermi level regions caused by Ni-3d–In-5p hybridization when Sn is replaced by In. The equilibrium equation of state results show that the alloys Ni 8 Mn 6 Sn 2−x In x exhibit an energetically degenerated effect for an In content of x = ∼1.5. This implies the coexistence of antiparallel and parallel configurations in the austenite.

  3. Nomograms to calculate stability in slate and granite spoil heaps; Abacos para el calculo de estabilidad en escombreras de pizarra y granito

    Energy Technology Data Exchange (ETDEWEB)

    Paz Freire, M.; Taboada Castro, J.; Rivas Brea, T.; Giraldez Perez, E.; Araujo Fernandez, M.

    2011-07-01

    One of the main problems involved in the mining of slate and ornamental granite is the unavoidable generation of waste rock, which must be stored in spoil heaps under suitably integrated, secure and stable conditions. Our work here focuses on this last point. To study the risk of instability within spoil heaps we have analysed the performance of a wide number of models with regard to circular slope failure, taking into account the different degrees of compactness of the material, the characteristics of the material itself, the effect of water pressure and the geometry of the heap. From this analysis we obtained more than 300 safety criteria, which were then used to draw up a series of nomograms to allow us to determine the risk of sliding in any granite or slate spoil heap. Thus, nomograms prove themselves to be suitable, quick, easy-to-use tools for preliminary studies of new structures, for periodic analyses of existing structures and to investigate structures that are due to be modified. (Author) 24 refs.

  4. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Son (ed.) [Canadian Nuclear Safety Commission (Canada); Lanru Jing (ed.) [Royal Institute of Technology, Stockholm (Sweden); Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Chijimatzu, Masakazu [Hazama Corporation (Japan); Jussila, Petri [Helsinki Univ. of Technology, Helsinki (Finland); Rutqvist, Jonny [Lawrence Berkeley National Laboratory CA (United States)

    2007-02-15

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the

  5. DECOVALEX-THMC Project. Task A. Influence of near field coupled THM phenomena on the performance of a spent fuel repository. Report of Task A1: Preliminary scoping calculations

    International Nuclear Information System (INIS)

    Nguyen, Son; Lanru Jing; Boergesson, Lennart; Chijimatzu, Masakazu; Jussila, Petri; Rutqvist, Jonny

    2007-02-01

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report presents the definition of the first phase, Task A-1, of the Task A of the project. The task is a working example of how interaction between THMC modelling and SA analysis could be performed. Starting with the technical definition of the Task A, the report presents the results of preliminary THM calculations with a purpose of an initial appreciation of the phenomena and material properties that must be better understood in subsequent phases. Many simplifications and assumptions were introduced and the results should be considered under these assumptions. Based on the evaluation of the multiple teams' results, a few points of concern were identified that may guide the successive phases of Task A studies: 1. The predicted maximum total stress in the MX-80 bentonite could slightly exceed the 15 MPa design pressure for the container

  6. Effects of rare-earth substitution on the stability and electronic structure of REZnOSb (RE = La-Nd, Sm-Gd) investigated via first-principles calculations

    International Nuclear Information System (INIS)

    Guo Kai; Man Zhenyong; Cao Qigao; Chen Haohong; Guo Xiangxin; Zhao Jingtai

    2011-01-01

    Graphical abstract: The structure stability of REZnOSb decreases with varying rare-earth from La to Gd because of the increased binding energy. Research highlights: → As increasing the atomic number of the RE, the structural stability of REZnOSb decreases. → Varying the rare-earth elements from La to Gd, the covalent interactions between [ZnSb] and [LaO] layer are enhanced by 4f-electrons. → The electrical transport properties of REZnOSb could be improved using the large atomic number of the RE. - Abstract: The structural stability, chemical bonding, Mulliken populations, and charge-density distribution of REZnOSb (RE = La-Nd, Sm-Gd) were investigated by first-principles calculations. Unit cell parameters calculated by the generalized gradient approximation (GGA) are in better agreement with experimental results than those derived from the local density approximation (LDA). Binding energy comparisons indicate that the structural stability of REZnOSb decreases with the increment of the atomic number of the RE, as confirmed by X-ray diffraction (XRD) results. Semimetal or narrow band-gap semiconductor behaviors are found for selected REZnOSb. Moreover, chemical bonding analysis shows that there exist considerable polar covalent interactions between the participating atoms. It also reveals that the [ZnSb] layers receive some electrons from the [LaO] layers (donor) as an electrons acceptor and holes transport tunnel. The covalent interactions between the [ZnSb] and [LaO] layers, which are enhanced by 4f-electrons of the RE, are supposed to improve the electrical transport properties.

  7. Etude préliminaire de la stabilité à l'hydrolyse des polyimides 6F Preliminary Study of the Hydrolysis Stability of 6f Polyimides

    Directory of Open Access Journals (Sweden)

    Mileo J. C.

    2006-11-01

    Full Text Available L'évaluation comparative du comportement en solution des polylmides 6F fait ressortir que ces nouveaux polymères, doués d'une stabilité thermique élevée par référence à l'analyse thermogravimétrique, ont, par contraste, une résistance beaucoup plus limitée aux influences ioniques et que l'hydrolyse, qui entraîne une réduction substantielle de leur masse moléculaire, est, dans leur cas, un processus de dégradation d'importance majeure. Despite its importance, particularly during the phase-inversion creation of asymmetrical gaseous-permeation membranes, the behavior in solution of polyImides derived from 4,4'-hexafluoroisopropylidenediphthalic anhydride has not, to our knowledge, been the subject of any published report. The present project was thus undertaken to assess the hydrolysis resistance of such polymers. This article describes and interprets some results highlighting the influence of structural factors. The products, which differ in the nature of both the initial diamine and dianhydride, were prepared by thermal polyheterocyclization in a single stage in different solvents at 200°C, and their stability was determined by the variations in their intrinsic viscosity after aging in a sealed tube at 90°C. Hydrolysis does not affect all 6F polyImides in a uniform way but seems to be governed by differences in the chemical affinity and in the morphology of the chains. Polymers having an increasing number of alkyl groups on the aminated remainder show a less and less marked susceptibility. A more specific fragility, however, affects polyImides having a carboxylic acid group. Other polar substituents have a stabilizing influence. A comparison with other polyImides is undeniably unfavorable to 6F derivatives. Degradation is very marked in dipolar aprotic solvents, whereas it appears quite limited in m-cresol. It apparantly cannot be blamed on the possible presence of uncyclized acid-amide units. The influence of the amount of

  8. Investigations of slope stability

    Energy Technology Data Exchange (ETDEWEB)

    Nonveiller, E.

    1979-01-01

    The dynamics of slope slides and parameters for calculating slope stability is discussed. Two types of slides are outlined: rotation slide and translation slide. Slide dynamics are analyzed according to A. Heim. A calculation example of a slide which occurred at Vajont, Yugoslavia is presented. Calculation results differ from those presented by Ciabatti. For investigation of slope stability the calculation methods of A.W. Bishop (1955), N. Morgenstern and M. Maksimovic are discussed. 12 references

  9. Preliminary Assessment About Genetic Diversity, The Stability Of Potential Mutants From Two Varieties Of Chrysanthemum Morifolium Ramat. (Bronze DOA And Purple Farm) Via Gamma Irradiation

    International Nuclear Information System (INIS)

    Nguyen Tuong Mien; Le Ngoc Trieu; Le Tien Thanh; Pham Van Nhi; Huynh Thi Trung

    2014-01-01

    The objects of radiation breeding were chosen, collected and in vitro propagated. The suitable modalities for acute and chronic irradiation the materials were determined. Two acute and one chronic irradiation series were executed. Thus, the irradiated materials were achieved to screening for the mutants. In this study, on farm, through screening 18 phenotypic mutants of both chrysanthemums were recorded and collected including 6 potential mutants that selected for next research based on their phenotypic differences to the originals, their aesthetic and low mosaic. These 6 potential mutants together with their original varieties were micro-propagated to induce the potential mutant lines for estimation on farm of mutant characteristic segregation rates. Six potential mutant lines of E2a, E2c, E28, E29, I7, I8 are morphologically and genetically different to their original varieties, possess the identification markers and aestheticism. They were morphologically stable on farm through 3 series of growing on farm at M1V3, M1V5 and M1V7 generations. In the genetic respect, they possessed the high stabilities through in vitro generations. All of these criteria show that, these mutant lines were already to be registered as temporary cultivars/varieties. (author)

  10. Relative Stability of the La and Lb Excited States in Adenine and Guanine: Direct Evidence from TD-DFT Calculations of MCD Spectra.

    Science.gov (United States)

    Santoro, Fabrizio; Improta, Roberto; Fahleson, Tobias; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia

    2014-06-05

    The relative position of La and Lb ππ* electronic states in purine nucleobases is a much debated topic, since it can strongly affect our understanding of their photoexcited dynamics. To assess this point, we calculated the absorption and magnetic circular dichroism (MCD) spectra of adenine, guanine, and their nucleosides in gas-phase and aqueous solution, exploiting recent developments in MCD computational technology within time-dependent density functional theory. MCD spectroscopy allows us to resolve the intense S0→ La transition from the weak S0→ Lb transition. The spectra obtained in water solution, by using B3LYP and CAM-B3LYP functionals and describing solvent effect by cluster models and by the polarizable continuum model (PCM), are in very good agreement with the experimental counterparts, thus providing direct and unambiguous evidence that the energy ordering predicted by TD-DFT, La < Lb, is the correct one.

  11. Remedial action plan and site design for stabilization of the inactive uranium processing site at Naturita, Colorado. Appendix A of Attachment 3: Calculations, Final

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    This report contains calculations for: hydraulic gradients for Alluvial Aquifer and Salt Wash Aquifer; slug test analysis to determine hydraulic conductivity for Alluvial Aquifer and Salt Wash Aquifer; average linear groundwater velocity for Alluvial Aquifer and Salt Wash Aquifer; statistical analysis of the extent of existing groundwater contamination; hydraulic gradients for Dakota/Burro Canyon Formation and Salt Wash Aquifer; slug test analysis to determine hydraulic conductivity for Dakota/Burro Canyon Formation and Perched Salt Wash Aquifer; determination of hydraulic conductivity of the Dakota/Burro Canyon Formation from Packer Tests; average linear groundwater velocity for Dakota/Burro Canyon and Salt Wash Aquifer; chemical and mineralogical characterization of core samples from the Dry Flats Disposal Site; and demonstration of low groundwater yield from Uppermost Aquifer.

  12. Stability, elastic properties and fracture toughness of Al0.75X0.75B14 (X=Sc, Ti, V, Cr, Y, Zr, Nb, Mo) investigated using ab initio calculations

    International Nuclear Information System (INIS)

    Emmerlich, Jens; Thieme, Niklas; To Baben, Moritz; Music, Denis; Schneider, Jochen M

    2013-01-01

    The effect of the transition metal valence electron concentration on the energy of formation, effective charge of B icosahedra, elastic properties, surface energy and fracture toughness was calculated using density functional theory for icosahedral transition metal borides of AlXB 14 (X=Sc, Ti, V, Cr, Y, Zr, Nb, Mo). Consistent with previous work on AlYB 14 (Kölpin et al 2009 J. Phys.: Condens. Matter 21 355006) it is shown that phase stability is generally dependent on the effective charge of the icosahedral transition metal borides. Also, ionization potential and electronegativity are identified as parameters affecting the effective charge of B icosahedra suitable for use in predicting the phase stability. Al 0.75 Y 0.75 B 14 , Al 0.75 Sc 0.75 B 14 and Al 0.75 Zr 0.75 B 14 have been identified as promising phases for application as protective coatings as they exhibit high phase stability and stiffness combined with a comparatively high fracture toughness. (paper)

  13. New strategy for minor actinides partitioning preliminary results on the electrovolatilization of ruthenium and on the stabilization of Am(IV) in nitric acid with phosphotunsgstate ligand

    International Nuclear Information System (INIS)

    Adnet, J.M.; Madic, C.

    1989-01-01

    On problems related to the long term storage in deep geological repositories of high active wastes (H.A.W.) is due to the presence of minor actinide isotopes. Thus after the decay of the fission products (≅ 300 years) the toxicity of these H.A.W. is mainly due to the minor actinides. One solution is based on actinide partitioning followed by transmutation into fission products with short half-lives. A simpler processes than those developed previously, can be based on the possible oxidation of minor actinides to the + IV or + VI oxidation states and their selective extraction. The first step to study is the elimination of the ruthenium (whose presence would be detrimental to oxidize minor actinides) which can be done by electrovolatilization of Ru on the RuO 4 form. The rate of electrovolatilization can be increased by the use of the following electronic mediators, AgI/AgII(1); CeIII/Ce(2), and CoII/CoIII(3), the efficiency of which decreases in the order: 1 > 2 > 3. The effectiveness of that process has been proven when treating real H.A.W solution produced during the study of the reprocessing of a MOX fuel irradiated to as burn-up of 52 GWd/t in a LWR: complete Ru removal was obtained. The second part of the study concerns the electrochemical oxidation of AmIII in nitric acid solutions in the presence of a strong complexing agent: P 2 W 17 O 61 K 10 (P.W.).Total americium oxidation to AmIV can be obtained in nitric acid solution with a concentration up to 8 M. No particular drawback was induced by the presence of an amount of lanthanide III (NdIII) in 6 fold excess vs P.W. The stability of AmIV was studied. The other actinides will be present in these solutions, after the electrochemical oxidation step, in the + VI or+ IV oxidation states, thus a selective extraction (vs fission products) could be performed. A possible way to extract actinide IV/P.W complexes is to use dodecylamine nitrate as extractant

  14. Three recent TDHF calculations

    International Nuclear Information System (INIS)

    Weiss, M.S.

    1981-05-01

    Three applications of TDHF are discussed. First, vibrational spectra of a post grazing collision 40 Ca nucleus is examined and found to contain many high energy components, qualitatively consistent with recent Orsay experiments. Second, the fusion cross section in energy and angular momentum are calculated for 16 O + 24 Mg to exhibit the parameters of the low l window for this system. A sensitivity of the fusion cross section to the effective two body potential is discussed. Last, a preliminary analysis of 86 Kr + 139 La at E/sub lab/ = 505 MeV calculated in the frozen approximation is displayed, compared to experiment and discussed

  15. Preliminary designs: passive solar manufactured housing. Technical status report

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-12

    The criteria established to guide the development of the preliminary designs are listed. Three preliminary designs incorporating direct gain and/or sunspace are presented. Costs, drawings, and supporting calculations are included. (MHR)

  16. Ideal MHD stability analysis of KSTAR target AT mode

    International Nuclear Information System (INIS)

    Yi, S.M.; Kim, J.H.; You, K.I.; Kim, J.Y.

    2009-01-01

    Full text: A main research objective of KSTAR (Korea Superconducting Tokamak Advanced Research) device is to demonstrate the steady-state operation capability of high-performance AT (Advanced Tokamak) mode. To meet this goal, it is critical for KSTAR to have a good MHD stability boundary, particularly against the high-beta ideal instabilities such as the external kink and the ballooning modes. To support this MHD stability KSTAR has been designed to have a strong plasma shape and a close interval between plasma and passive- plate wall. During the conceptual design phase of KSTAR, a preliminary study was performed to estimate the high beta MHD stability limit of KSTAR target AT mode using PEST and VACUUM codes and it was shown that the target AT mode can be stable up to β N ∼ 5 with a well-defined plasma pressure and current profiles. Recently, a new calculation has been performed to estimate the ideal stability limit in various KSTAR operating conditions using DCON code, and it has been observed that there is some difference between the new and old calculation results, particularly in the dependence of the maximum β N value on the toroidal mode number. Here, we thus present a more detailed analysis of the ideal MHD stability limit of KSTAR target AT mode using various codes, which include GATO as well as PEST and DCON, in the comparison of calculation results among the three codes. (author)

  17. Declination Calculator

    Data.gov (United States)

    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...

  18. Analysis of rainfall-induced shallow landslides in Jamne and Jaszcze stream valleys (Polish Carpathians – preliminary results

    Directory of Open Access Journals (Sweden)

    Zydroń Tymoteusz

    2016-03-01

    Full Text Available Analysis of rainfall-induced shallow landslides in Jamne and Jaszcze stream valleys (Polish Carpathians - preliminary results. Preliminary shallow landslide susceptibility mapping of the Jamne and Jaszcze stream valleys, located in the Polish Flysch Carpathians, is presented in the paper. For the purpose of mapping, there were used SINMAP and Iverson’s models integrating infiltration and slope stability calculations. The calibration of the used models parameters, obtained from limited field and laboratory tests, was performed using data from 8-9 July 1997, when as a consequence of a very intense rainfall, 94 shallow landslides were observed on meadows and arable lands. A comparison of the slope stability calculation results and the localisation of the noticed shallow landslides showed satisfactory agreement between localisation of the observed and computed unstable areas. However, it was concluded that better simulation results were obtained using Iverson’s model.

  19. Desenvolvimento e estudos de estabilidade preliminares de emulsões O/A contendo Cetoconazol 2,0% = Development and Preliminary Stability Evaluations of O/W emulsion containing Ketoconazole 2.0%

    Directory of Open Access Journals (Sweden)

    Vanessa Catalá Casteli

    2008-07-01

    Full Text Available O objetivo deste trabalho foi desenvolver emulsões O/A contendo Cetoconazol 2,0% e avaliar sua estabilidade preliminar por meio da análise de suas características físicoquímicas, tais como homogeneidade, formação de agregados, floculação, cremeação ecoalescência. As emulsões foram formuladas utilizando diferentes bases autoemulsionantes, compostas por álcool cetoestearílico, álcool etoxilado, álcool graxos superiores, ácido esteárico, lanolina e outros. As emulsões foram submetidas aos testes de centrifugação,estresse térmico e ciclo gela-degela, e suas características organolépticas e físico-químicas foram avaliadas no início e no final de cada ensaio. Todas as amostras mantiveram sua homogeneidade após o teste de centrifugação, mas somente os sistemas preparados comceras autoemulsionáveis constituídas por álcool graxos superiores (Polawax NF® e Copolímero de Amônio Acriloil dimetiltaurato VP, Trilauril 4 fosfato, Sesquisosterato de metil glicose, Óleo de flores de verão e Tetradibutil pentaeritritil hidroxihidrocinamato deGlicerina (Hostacerin NCB® mantiveram sua estabilidade após testes de estresse térmico e ciclo gela-degela.The objective of this work was the development of O/W emulsions containing Ketoconazole 2.0% and to evaluate their preliminary stability by analyzing physical-chemical characteristics such as homogeneity, aggregation formation, flocculation, creaming and coalescence. The emulsions were formulated using different self-emulsifying bases, composed of cetearyl alcohol, ethoxylalcohol, higher fatty alcohol, stearic acid, lanolin and others. The O/W emulsions were evaluated by centrifugation test, thermal stress test, and freezing/defrosting cycles, and its organoleptic and physical-chemistry characteristics were analyzed before and after eachassay. All samples maintained their homogeneity after the centrifugation test, but only the systems prepared with self emulsifying composed of

  20. Transfer Area Mechanical Handling Calculation

    International Nuclear Information System (INIS)

    Dianda, B.

    2004-01-01

    This calculation is intended to support the License Application (LA) submittal of December 2004, in accordance with the directive given by DOE correspondence received on the 27th of January 2004 entitled: ''Authorization for Bechtel SAX Company L.L. C. to Include a Bare Fuel Handling Facility and Increased Aging Capacity in the License Application, Contract Number DE-AC--28-01R W12101'' (Arthur, W.J., I11 2004). This correspondence was appended by further Correspondence received on the 19th of February 2004 entitled: ''Technical Direction to Bechtel SAIC Company L.L. C. for Surface Facility Improvements, Contract Number DE-AC--28-OIRW12101; TDL No. 04-024'' (BSC 2004a). These documents give the authorization for a Fuel Handling Facility to be included in the baseline. The purpose of this calculation is to establish preliminary bounding equipment envelopes and weights for the Fuel Handling Facility (FHF) transfer areas equipment. This calculation provides preliminary information only to support development of facility layouts and preliminary load calculations. The limitations of this preliminary calculation lie within the assumptions of section 5 , as this calculation is part of an evolutionary design process. It is intended that this calculation is superseded as the design advances to reflect information necessary to support License Application. The design choices outlined within this calculation represent a demonstration of feasibility and may or may not be included in the completed design. This calculation provides preliminary weight, dimensional envelope, and equipment position in building for the purposes of defining interface variables. This calculation identifies and sizes major equipment and assemblies that dictate overall equipment dimensions and facility interfaces. Sizing of components is based on the selection of commercially available products, where applicable. This is not a specific recommendation for the future use of these components or their

  1. CONTAIN calculations

    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.)

  2. Cable Stability

    Energy Technology Data Exchange (ETDEWEB)

    Bottura, L [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    Superconductor stability is at the core of the design of any successful cable and magnet application. This chapter reviews the initial understanding of the stability mechanism, and reviews matters of importance for stability such as the nature and magnitude of the perturbation spectrum and the cooling mechanisms. Various stability strategies are studied, providing criteria that depend on the desired design and operating conditions.

  3. Burnout calculation

    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

  4. Research on parafoil stability using a rapid estimate model

    Directory of Open Access Journals (Sweden)

    Hua YANG

    2017-10-01

    Full Text Available With the consideration of rotation between canopy and payload of parafoil system, a four-degree-of-freedom (4-DOF longitudinal static model was used to solve parafoil state variables in straight steady flight. The aerodynamic solution of parafoil system was a combination of vortex lattice method (VLM and engineering estimation method. Based on small disturbance assumption, a 6-DOF linear model that considers canopy additional mass was established with benchmark state calculated by 4-DOF static model. Modal analysis of a dynamic model was used to calculate the stability parameters. This method, which is based on a small disturbance linear model and modal analysis, is high-efficiency to the study of parafoil stability. It is well suited for rapid stability analysis in the preliminary stage of parafoil design. Using this method, this paper shows that longitudinal and lateral stability will both decrease when a steady climbing angle increases. This explains the wavy track of the parafoil observed during climbing.

  5. Reliability calculations

    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)

  6. Calculator calculus

    CERN Document Server

    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...

  7. A PRELIMINARY JUPITER MODEL

    International Nuclear Information System (INIS)

    Hubbard, W. B.; Militzer, B.

    2016-01-01

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity

  8. A PRELIMINARY JUPITER MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, W. B. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Militzer, B. [Department of Earth and Planetary Science, Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2016-03-20

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity.

  9. Reliability Calculations

    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...

  10. Radiolabelling of RC-160: preliminary results

    International Nuclear Information System (INIS)

    Verdera, E.S.; Balter Binsky, H.S.; Robles, A.M.; Rodriguez, G.; Souto, B.; Laiz, J.; Oliver, P.; Leon, E.

    1998-01-01

    Vapreotide (RC-160) was labelled with 125 I using Chloramine-T and Iodogen methods and with 99m Tc by a direct method with sodium ditionite as reducing agent in the presence of ascorbic acid. Several methods of purification and quality control were evaluated. Yields of the reactions and of purification steps were calculated. The results obtained for the radioiodination reactions showed higher yields when limiting Chloramine-T method was used. Labelling of RC-160 with 99m Tc indicated better yields when high radioactivity concentration of the radionuclide was used. Stability of the products obtained was assessed at different post-labelling times by selected quality control methods: Sep-Pak cartridge as purification method and chromatography by RP-HPLC and ITLC-SG using saline solution as solvent. It was demonstrated that I-125-RC-160 and Tc-99m-RC-160 were stable during five weeks (at -20 deg. C) and 6 hours (at room temperature) respectively. Preliminary biodistribution of Tc-99m-RC-160 in normal rats and mice were done showing different biological behaviour compared with control animals injected with pertechnetate. In conclusion, RC-160 was successfully labelled with both radionuclides, with radiochemical purity higher than 95%. These results encourage further research work in animal models as well as to investigate the biochemical behaviour of radiolabelled peptide. (author)

  11. Stabilization of compactible waste

    International Nuclear Information System (INIS)

    Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1990-09-01

    This report summarizes the results of series of experiments performed to determine the feasibility of stabilizing compacted or compactible waste with polymers. The need for this work arose from problems encountered at disposal sites attributed to the instability of this waste in disposal. These studies are part of an experimental program conducted at Brookhaven National Laboratory (BNL) investigating methods for the improved solidification/stabilization of DOE low-level wastes. The approach taken in this study was to perform a series of survey type experiments using various polymerization systems to find the most economical and practical method for further in-depth studies. Compactible dry bulk waste was stabilized with two different monomer systems: styrene-trimethylolpropane trimethacrylate (TMPTMA) and polyester-styrene, in laboratory-scale experiments. Stabilization was accomplished by wetting or soaking compactible waste (before or after compaction) with monomers, which were subsequently polymerized. Three stabilization methods are described. One involves the in-situ treatment of compacted waste with monomers in which a vacuum technique is used to introduce the binder into the waste. The second method involves the alternate placement and compaction of waste and binder into a disposal container. In the third method, the waste is treated before compaction by wetting the waste with the binder using a spraying technique. A series of samples stabilized at various binder-to-waste ratios were evaluated through water immersion and compression testing. Full-scale studies were conducted by stabilizing two 55-gallon drums of real compacted waste. The results of this preliminary study indicate that the integrity of compacted waste forms can be readily improved to ensure their long-term durability in disposal environments. 9 refs., 10 figs., 2 tabs

  12. Shielding calculations for NET

    International Nuclear Information System (INIS)

    Verschuur, K.A.; Hogenbirk, A.

    1991-05-01

    In the European Fusion Technology Programme there is only a small activity on research and development for fusion neutronics. Never-the-less, looking further than blanket design now, as ECN is getting involved in design of radiation shields for the coils and biological shields, it becomes apparent that fusion neutronics as a whole still needs substantial development. Existing exact codes for calculation of complex geometries like MCNP and DORT/TORT are put over the limits of their numerical capabilities, whilst approximate codes for complex geometries like FURNACE and MERCURE4 are put over the limits of their modelling capabilities. The main objective of this study is just to find out how far we can get with existing codes in obtaining reliable values for the radiation levels inside and outside the cryostat/shield during operation and after shut-down. Starting with a 1D torus model for preliminary parametric studies, more dimensional approximation of the torus or parts of it including the main heterogeneities should follow. Regular contacts with the NET-Team are kept, to be aware of main changes in NET design that might affect our calculation models. Work on the contract started 1 July 1990. The technical description of the contract is given. (author). 14 refs.; 4 figs.; 1 tab

  13. Preliminary Monthly Climatological Summaries

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Preliminary Local Climatological Data, recorded since 1970 on Weather Burean Form 1030 and then National Weather Service Form F-6. The preliminary climate data pages...

  14. Assessment of the primary stability of root analog zirconia implants designed using cone beam computed tomography software by means of the Periotest® device: An ex vivo study. A preliminary report.

    Science.gov (United States)

    Matys, Jacek; Świder, Katarzyna; Flieger, Rafał; Dominiak, Marzena

    2017-08-01

    The implant primary stability is a fundamental prerequisite for a success of osseointegration process which determines the prosthetic reconstruction time. The aim of the present study was to assess the quality and precision of modern conical bone computer tomography (CBCT) software in preparing root analog zirconia implants (RAZIs) by measuring its primary stability by means of the Periotest device. Thirteen pig jaws with proper erupted first premolar (P1) teeth were used in the study. The CBCT examination was conducted in the area of the P1 tooth in each mandible. The 3-dimensional (3D) view of each tooth was designed from CBCT scan. The created 3D images were used to prepare root analog zirconia implants milled from a medical-grade zirconia block by means of laboratory milling. The RAZIs and titanium implants were placed into an alveolar socket after the tooth had been removed. The primary stability of the teeth before their extraction (G1), RAZIs (G2) and titanium implants (G3) were checked by Periotest devices. The mean results in PTV were: 15.9, 3.35, 12.7 for G1, G2 and G3 group, respectively. RAZIs during immediate loading achieved a significantly higher primary stability (lower Periotest value) as compared to the teeth and implants. The modern CBCT device allows us to design a precise image of an extracted tooth for the purpose of manufacturing a root analog implant. The additional feature of the surgical protocol using RAZI is the possibility of avoiding the augmentation procedure, which reduces the whole cost of the treatment.

  15. The rock mechanical stability of the VLJ repository

    International Nuclear Information System (INIS)

    Kuula, H.; Johansson, E.

    1991-03-01

    The aim of the study was to determine the rock mechanical stability around the VLJ repository based on the rock mechanical monitoring and rock mechanical modeling. Rock mechanical calculations were made in order to calculate the rock mass displacements and to analyze the stability around the VLJ repository The calculations were performed with three diiferent methods: continuum finite difference code FLAC, distinct element code UDEC and three dimensional distinct element code 3DEC. The first analyses were based on preliminary site investigations. The final modeling was based on investigations and rock mechanical monitoring done during the excavation. Some sensitive analyses were also performed. The modelled rock mass behaviour and the measured behaviour are generally close to each other. Both results show that the VLJ repository is rock mechanically stable. The modelled displacements and stresses were small enough to cause no instability around the rock caverns. The measured values do not indicate any discontinuous deformations like block movements or joint slip. The measured displacements in the extensometers during excavation indicates that the rock mass is even stiffer than anticipated

  16. On the magneto-roton gap and the Laughlin State Stability

    International Nuclear Information System (INIS)

    Cabo Montes de Oca, A.

    1998-07-01

    It is argued that the Girvin, MacDonald and Platzman (GMP) evaluation of the magneto-roton spectrum, in spite of probably being a sensible estimate of the excitation spectrum around the real FQHE ground state, does not imply the variational stability of the Laughlin state. The supplementary corrections needed to produce a variational calculation around the ν=1/3 Laughlin state, are evaluated approximately. These preliminary results indicate the existence of lower lying states for a range of wavevector values. (author)

  17. Estudio preliminar para el diseño de una máquina productora de bloques con suelos estabilizados. // Preliminary study for the design of a block machine producer with stabilized soil.

    Directory of Open Access Journals (Sweden)

    A. Díaz Nimo

    2005-01-01

    Full Text Available El diseño final de una máquina termina después de construirse un prototipo y verificar que funcione correctamente. Noobstante, antes de construir el prototipo se puede modelar el equipo para detectar problemas que puedan surgir en lapropuesta inicial. La idea anterior se aplicó en una máquina para la producción de bloques a partir de suelo estabilizado.Los esquemas, cinemático y estructural de la máquina, se hicieron a partir del análisis de equipos similares y de ideaspropias. Se incluyó un sistema de accionamiento óleo hidráulico para obtener una fuerza de compactación elevada y teneruna alta productividad de bloques con la calidad requerida. Posteriormente, se determinó, de forma experimental, la fuerzade compactación aplicada a un suelo estabilizado, para producir bloques que resistan un esfuerzo a compresión establecidopor la norma de calidad. Con la fuerza de compactación definida, se modelaron las partes peligrosas del equipo, en unprograma de elementos finitos. Se muestran los resultados, señalándose como en algunos elementos, la propuesta originalfallaba, proponiéndose nuevas soluciones.Palabras claves: Diseño mecánico, suelo estabilizado, método de elementos finitos.__________________________________________________________________________AbstractThe final design of machine finishes after built a prototype and verify that it works correctly. Nevertheless, before buildingthe prototype you can model the equipment in order to detect problems that can arise in the initial proposal. The previousidea was applied in a machine for the production of blocks starting from stabilized soil. The schemes, cinematic andstructure of the machine, were made starting from the analysis of similar equipment and of own ideas. A system of oilhydraulic power was included allowing a high force of compression and having a high block productivity with the requiredquality. Later on, it was determined, in an experimental way, the compression

  18. Estudio preliminar para el diseño de una máquina productora de bloques con suelos estabilizados. // Preliminary study for the design of a block machine producer with stabilized soil.

    Directory of Open Access Journals (Sweden)

    A. Díaz Nimo

    2006-09-01

    Full Text Available El diseño final de una máquina termina después de construirse un prototipo y verificar que funcione correctamente. Noobstante, antes de construir el prototipo se puede modelar el equipo para detectar problemas que puedan surgir en lapropuesta inicial. La idea anterior se aplicó en una máquina para la producción de bloques a partir de suelo estabilizado.Los esquemas, cinemático y estructural de la máquina, se hicieron a partir del análisis de equipos similares y de ideaspropias. Se incluyó un sistema de accionamiento óleo hidráulico para obtener una fuerza de compactación elevada y teneruna alta productividad de bloques con la calidad requerida. Posteriormente, se determinó, de forma experimental, la fuerzade compactación aplicada a un suelo estabilizado, para producir bloques que resistan un esfuerzo a compresión establecidopor la norma de calidad. Con la fuerza de compactación definida, se modelaron las partes peligrosas del equipo, en unprograma de elementos finitos. Se muestran los resultados, señalándose como en algunos elementos, la propuesta originalfallaba, proponiéndose nuevas soluciones.Palabras claves: Diseño mecánico, suelo estabilizado, método de elementos finitos._____________________________________________________________________________AbstractThe final design of machine finishes after built a prototype and verify that it works correctly. Nevertheless, before buildingthe prototype you can model the equipment in order to detect problems that can arise in the initial proposal. The previousidea was applied in a machine for the production of blocks starting from stabilized soil. The schemes, cinematic andstructure of the machine, were made starting from the analysis of similar equipment and of own ideas. A system of oilhydraulic power was included allowing a high force of compression and having a high block productivity with the requiredquality. Later on, it was determined, in an experimental way, the

  19. Staggering towards a calculation of weak amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, S.R.

    1988-09-01

    An explanation is given of the methods required to calculate hadronic matrix elements of the weak Hamiltonians using lattice QCD with staggered fermions. New results are presented for the 1-loop perturbative mixing of the weak interaction operators. New numerical techniques designed for staggered fermions are described. A preliminary result for the kaon B parameter is presented. 24 refs., 3 figs.

  20. The Stability of Galaxy Disks

    NARCIS (Netherlands)

    Westfall, K. B.; Andersen, D. R.; Bershady, M. A.; Martinsson, T. P. K.; Swaters, R. A.; Verheijen, M. A. W.; Seigar, M.S.; Treuthardt, P.

    2014-01-01

    We calculate the stellar surface mass density (Σ*) and two-component (gas+stars) disk stability (QRW) for 25 late-type galaxies from the DiskMass Survey. These calculations are based on fits of a dynamical model to our ionized-gas and stellar kinematic data performed using a Markov Chain Monte Carlo

  1. Preliminary considerations concerning actinide solubilities

    International Nuclear Information System (INIS)

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented

  2. Stabilizing Niger

    DEFF Research Database (Denmark)

    Hahonou, Eric Komlavi

    international intervention in Niger. Their main objective is to secure their own strategic, economic and political interests by strengthening the Nigerien authorities through direct intervention and capacity building activities. For western states reinforcing state security institutions and stabilizing elite...

  3. New image-stabilizing system

    Science.gov (United States)

    Zhao, Yuejin

    1996-06-01

    In this paper, a new method for image stabilization with a three-axis image- stabilizing reflecting prism assembly is presented, and the principle of image stabilization in this prism assembly, formulae for image stabilization and working formulae with an approximation up to the third power are given in detail. In this image-stabilizing system, a single chip microcomputer is used to calculate value of compensating angles and thus to control the prism assembly. Two gyroscopes act as sensors from which information of angular perturbation is obtained, three stepping motors drive the prism assembly to compensate for the movement of image produced by angular perturbation. The image-stabilizing device so established is a multifold system which involves optics, mechanics, electronics and computer.

  4. Spectra and structure of silicon containing compounds. XXXII. Raman and infrared spectra, conformational stability, vibrational assignment and ab initio calculations of n-propylsilane-d0 and Si-d3.

    Science.gov (United States)

    Durig, James R; Pan, Chunhua; Guirgis, Gamil A

    2003-03-15

    The infrared (3100-40 cm(-1)) and Raman (3100-20 cm(-1)) spectra of gaseous and solid n-propylsilane, CH(3)CH(2)CH(2)SiH(3) and the Si-d(3) isotopomer, CH(3)CH(2)CH(2)SiD(3), have been recorded. Additionally, the Raman spectra of the liquids have been recorded and qualitative depolarization values obtained. Both the anti and gauche conformers have been identified in the fluid phases but only the anti conformer remains in the solid. Variable temperature (-105 to -150 degrees C) studies of the infrared spectra of n-propylsilane dissolved in liquid krypton have been recorded and the enthalpy difference has been determined to be 220+/-22 cm(-1) (2.63+/-0.26 kJ mol(-1)) with the anti conformer the more stable form. A similar value of 234+/-23 cm(-1) (2.80+/-0.28 kJ mol(-1)) was obtained for deltaH for the Si-d(3) isotopomer. At ambient temperature it is estimated that there is 30+/-2% of the gauche conformer present. The potential function governing the conformation interchange has been estimated from the far infrared spectral data, the enthalpy difference, and the dihedral angle of the gauche conformer, which is compared to the one predicted from ab initio MP2/6-31G(d) calculations. The barriers to conformational interchange are: 942, 970 and 716 cm(-1) for the anti to gauche, gauche to gauche, and gauche to anti conformers, respectively. Relatively complete vibrational assignments are proposed for both the n-propylsilane-d(0) and Si-d(3) molecules based on the relative infrared and Raman spectral intensities, infrared band contours, depolarization ratios, and normal coordinate calculations. The geometrical parameters, harmonic force constants, vibrational frequencies, infrared intensities, Raman activities and depolarization ratios, and energy differences have been obtained for the anti and gauche conformers from ab initio MP2/6-31G(d) calculations. Structural parameters and energy differences have also been obtained utilizing the larger 6-311 + G(d,p) and 6-311 + G(2

  5. Spectra and structure of silicon containing compounds. XXXII. Raman and infrared spectra, conformational stability, vibrational assignment and ab initio calculations of n-propylsilane-d 0 and Si-d 3

    Science.gov (United States)

    Durig, James R.; Pan, Chunhua; Guirgis, Gamil A.

    2003-03-01

    The infrared (3100-40 cm -1) and Raman (3100-20 cm -1) spectra of gaseous and solid n-propylsilane, CH 3CH 2CH 2SiH 3 and the Si-d 3 isotopomer, CH 3CH 2CH 2SiD 3, have been recorded. Additionally, the Raman spectra of the liquids have been recorded and qualitative depolarization values obtained. Both the anti and gauche conformers have been identified in the fluid phases but only the anti conformer remains in the solid. Variable temperature (-105 to -150 °C) studies of the infrared spectra of n-propylsilane dissolved in liquid krypton have been recorded and the enthalpy difference has been determined to be 220±22 cm -1 (2.63±0.26 kJ mol -1) with the anti conformer the more stable form. A similar value of 234±23 cm -1 (2.80±0.28 kJ mol -1) was obtained for Δ H for the Si-d 3 isotopomer. At ambient temperature it is estimated that there is 30±2% of the gauche conformer present. The potential function governing the conformation interchange has been estimated from the far infrared spectral data, the enthalpy difference, and the dihedral angle of the gauche conformer, which is compared to the one predicted from ab initio MP2/6-31G(d) calculations. The barriers to conformational interchange are: 942, 970 and 716 cm -1 for the anti to gauche, gauche to gauche, and gauche to anti conformers, respectively. Relatively complete vibrational assignments are proposed for both the n-propylsilane-d 0 and Si-d 3 molecules based on the relative infrared and Raman spectral intensities, infrared band contours, depolarization ratios, and normal coordinate calculations. The geometrical parameters, harmonic force constants, vibrational frequencies, infrared intensities, Raman activities and depolarization ratios, and energy differences have been obtained for the anti and gauche conformers from ab initio MP2/6-31G(d) calculations. Structural parameters and energy differences have also been obtained utilizing the larger 6-311+G(d,p) and 6-311+G(2d,2p) basis sets. From the isolated

  6. Mixed approach (numerical modeling / equilibrium analysis) for slope stability analysis: development and application to the dams and open pit mining; Une approche mixte (numerique/equilibre limite) pour le calcul de stabilite des ouvrages en terre: developpement et application aux barrages et talus miniers

    Energy Technology Data Exchange (ETDEWEB)

    Kourdey, A.

    2002-09-15

    The determination of the sliding surface of slope (dam, slope natural..) is one of the important and complicated problems in geotechnics. The Analyze of stability by the methods of Limit Equilibrium like the method of slices are the most used methods. They are able to determine a safety factor for a geometrically defined failure surface. These methods well adapted to the homogeneous mediums, have been developed a lot but they do not integrate the basic relations of mechanics (stress-strain). The numerical methods are better adapted to mediums having more complexity (effect of water, seismicity, fracturing,..). But, they are seldom used to determine a sliding surface and a safety factor. Each family offers appreciable advantages in the analysis of slope stability. For that purpose, we have developed a method that combines the advantages of the numerical methods as well as those of Limit Equilibrium allowing obtaining a slip surface determined by the calculated constraints. This slip surface may be imposed or better optimized, thus providing a minimal safety factor. Methods of operation research are used to obtain this surface. They are search methods by level, dynamic research.. or both at the same time. We integrated these developments in an existing computer code based on the method of Finite Differences known as FLAC. The stresses are determined for a linear behavior and for nonlinear. Interfaces and graphic tools are also produced to facilitate the analysis of stability. The validity of this approach was carried out for a standard case of slope, we analyzed and compared the results with the methods of Limit Equilibrium. The parametric study shows that this approach takes account of different parameters, which influences stability. We also kept a particular place for the application on real cases presenting slopes of different nature (dams, mining slops,...). (author)

  7. 3-D calculations for comparison with the experiments

    Energy Technology Data Exchange (ETDEWEB)

    Alrsen, A M; Bosser, R

    1973-09-27

    In order to analyse the axial power profile measurements an attempt has been made to do full 3-D calculations for the Dragon reactor. The calculations are still at a very early stage, but the methods used will be outlined here together with the plans for investigations to be carried out in the near future. Some preliminary-results are reported as no final results have yet been obtained. 3-D calculations are rather expensive because of the computer time consumption. It is therefore essential, before too many big computer jobs are spent, to find approximations which can save calculation time. On the other hand some savings, for instance in the number of mesh points, may cause totally wrong results. The ''proper'' calculations have therefore to be proceeded by a number of preliminary investigations, to ensure optimum accuracy and computer expenses. This report contains some of these preliminary studies.

  8. Macroeconomic stability

    DEFF Research Database (Denmark)

    Jespersen, Jesper

    2004-01-01

    It is demonstrated that full employment and sustainable development not necessarily are conflicting goals. On the other hand macroeconomic stability cannot be obtained without a deliberate labour sharing policy and a shift in the composition of private consumption away from traditional material...

  9. Stabilized superconductors

    International Nuclear Information System (INIS)

    Wong, J.

    1975-01-01

    The stable, high field, high current composite wire comprises multiple filaments in a depleted bronze matrix, each filament comprising a type II superconducting, beta-tungsten structure, intermetallic compound layer jacketing and metallurgically bonded to a stabilizing copper core, directly or via an intermediate layer of refractory metal

  10. Field investigation of keyblock stability

    International Nuclear Information System (INIS)

    Yow, J.L. Jr.

    1985-04-01

    Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. This engineering problem is divided into two parts: block identification, and evaluation of block stability. One stable keyblock and thirteen fallen keyblocks were observed in field investigations at the Nevada Test Site. Nine blocks were measured in detail sufficient to allow back-analysis of their stability. Measurements included block geometry, and discontinuity roughness and compressive strength. Back-analysis correctly predicted stability or failure in all but two cases. These two exceptions involved situations that violated the stress assumptions of the stability calculations. Keyblock faces correlated well with known joint set orientations. The effect of tunnel orientation on keyblock frequency was apparent. Back-analysis of physical models successfully predicted block pullout force for two-dimensional models of unit thickness. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were examined. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls block displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender. Rock mass temperature decreases reduce the confining stress magnitudes and can lead to failure. The pattern of stresses affecting each block face explains conceptually the occurrence of pyramidal keyblocks that are truncated near their apex

  11. Energetic prediction on the stability of A2Mg12Si7, A2Mg4Si3, and AMgSi in the A2Si–Mg2Si system (A = Ca, Sr and Ba) and their calculated electronic structures

    International Nuclear Information System (INIS)

    Imai, Yoji; Mori, Yoshihisa; Nakamura, Shigeyuki; Takarabe, Ken-ichi

    2014-01-01

    Highlights: • Formation energies of A 2 Mg 4 Si 3 , A 2 Mg 12 Si 7 , and AMgSi (A = Ca,Sr,Ba) were calculated. • All AMgSi are quite stable compared to mixture of A 2 Si and Mg 2 Si. • Ba 2 Mg 4 Si 3 and Sr 2 Mg 4 Si 3 are predicted to be stable, but Ca 2 Mg 4 Si 3 is not. • Ca 2 Mg 12 Si 7 and Sr 2 Mg 12 Si 7 are energetically unstable. • Stability of Ba 2 Mg 12 Si 7 is a tender subject. -- Abstract: In order to evaluate the relative stability of A 2 Mg 4 Si 3 , A 2 Mg 12 Si 7 , and AMgSi (A = Ca, Sr, and Ba) in the A 2 Si–Mg 2 Si system, electronic energy changes in the formation of these compounds were calculated using a density-functional theory with the Perdew–Wang generalized gradient approximations. It was found that (1) AMgSi’s are quite stable compared to equi-molar mixture of A 2 Si and Mg 2 Si, (2) Ba 2 Mg 4 Si 3 and Sr 2 Mg 4 Si 3 are also stable, (3) Ca 2 Mg 4 Si 3 and Ca 2 Mg 12 Si 7 are less stable than the mixture of CaMgSi and Mg 2 Si, and (4) Stability of Ba 2 Mg 12 Si 7 is a tender subject and Sr 2 Mg 12 Si 7 is energetically unstable compared to the mixture of Sr 2 Mg 4 Si 3 (or, SrMgSi) and Mg 2 Si. The presence of Sr 2 Mg 12 Si 7 may be due to the vibrational and/or configurational entropy, which are not treated in the present study. From the calculated electronic densities of state, complex compounds of SrMgSi and Mg 2 Si have both p-type and n-type character, depending on the ratio of SrMgSi and Mg 2 Si in that compound

  12. Optimal control theory applied to fusion plasma thermal stabilization

    International Nuclear Information System (INIS)

    Sager, G.; Miley, G.; Maya, I.

    1985-01-01

    Many authors have investigated stability characteristics and performance of various burn control schemes. The work presented here represents the first application of optimal control theory to the problem of fusion plasma thermal stabilization. The objectives of this initial investigation were to develop analysis methods, demonstrate tractability, and present some preliminary results of optimal control theory in burn control research

  13. Stabilization of Highway Expansive Soils with High Loss on Ignition ...

    African Journals Online (AJOL)

    This study was carried out to evaluate the effect of high loss on ignition content cement kiln dust on the stabilization of highway expansive soils. Laboratory tests were performed on the natural and stabilized soil samples in accordance with BS 1377 (1990) and BS 1924 (1990), respectively. The preliminary investigation ...

  14. Stability of mixing layers

    Science.gov (United States)

    Tam, Christopher; Krothapalli, A

    1993-01-01

    The research program for the first year of this project (see the original research proposal) consists of developing an explicit marching scheme for solving the parabolized stability equations (PSE). Performing mathematical analysis of the computational algorithm including numerical stability analysis and the determination of the proper boundary conditions needed at the boundary of the computation domain are implicit in the task. Before one can solve the parabolized stability equations for high-speed mixing layers, the mean flow must first be found. In the past, instability analysis of high-speed mixing layer has mostly been performed on mean flow profiles calculated by the boundary layer equations. In carrying out this project, it is believed that the boundary layer equations might not give an accurate enough nonparallel, nonlinear mean flow needed for parabolized stability analysis. A more accurate mean flow can, however, be found by solving the parabolized Navier-Stokes equations. The advantage of the parabolized Navier-Stokes equations is that its accuracy is consistent with the PSE method. Furthermore, the method of solution is similar. Hence, the major part of the effort of the work of this year has been devoted to the development of an explicit numerical marching scheme for the solution of the Parabolized Navier-Stokes equation as applied to the high-seed mixing layer problem.

  15. Ractor stability monitor

    International Nuclear Information System (INIS)

    Takeuchi, Yutaka.

    1991-01-01

    A stability monitor for a BWR type reactor determines the index of stability by statistic processing of signals from an average power region monitor or the like, but it takes much time and the reliability thereof is not always high. Then, parameters such as reactor core power are measured on every sampling periods as observation data and pretreatments such as normalization are applied successively, to obtain monitored amount and store them successively. Differentiation coefficient relative to time are calculated by using the observed amount at present and that one sample period before, to evaluate on a phasal plane using the amount of observation and the differentiation coefficient with time on the axes of coordinate. As a result, information relative to the stability can be represented accurately, thereby enabling to monitor the stability at a high accuracy. Further, judgement for the condition considering the amplitude is conducted upon oscillation, thereby enabling to conduct control operation certainly. The operation in a region where it has been limited under great caution can be conducted appropriately and safely, enabling to conduct controlled operation of excellent economical property. (N.H.)

  16. Bunched beam longitudinal stability

    International Nuclear Information System (INIS)

    Baartman, R.

    1991-05-01

    Instabilities driven by narrow-band impedances can be stabilized by Landau damping arising from the synchrotron frequency spread due to the nonlinearity of the rf wave-form. We calculate stability diagrams for various phase space distributions. We find that distributions without tails are unstable in the 'negative mass' regime (inductive impedance below transition or capacitive impedance above transition). We also find that longitudinal instability thresholds of the (usually neglected) higher order radial modes are lower than expected. For example, the next to lowest dipole mode has a lower threshold than the lowest sextupole mode even though the latter has the larger growth rate in the absence of Landau damping. (Author) 5 refs., 5 figs

  17. Second region of stability

    International Nuclear Information System (INIS)

    Greene, J.M.; Chance, M.S.

    1980-10-01

    A new type of axisymmetric magnetohydrodynamic equilibrium is presented. It is characterized by a region of pressure and safety factor variation with a short scale length imposed as a perturbation. The equilibrium consistent with these profile variations can be calculated by means of an asymptotic expansion. The flexibility obtained by generating such equilibria allows for a close examination of the mechanisms that are relevant to ballooning instabilities - ideal MHD modes with large toroidal mode number. The so-called first and second regions of stability against these modes are seen well within the limits of validity of the asymptotic expansion. It appears that the modes must be localized in regions with small values of the local shear of the magnetic field. The second region of stability occurs where the local shear is large throughout the range where the magnetic field line curvature is destabilizing

  18. Cadangan Full Preliminary Term Asuransi Dwiguna Dengan Hukum De Moivre

    OpenAIRE

    Faradilla, Sherly Mutya; ', Hasriati; Nababan, Tumpal Parulian

    2015-01-01

    This paper discusses premium reserve endowment life insurance for years. The reserve is calculated by the method of full preliminary term based on net annual premium, with the first net annual premium and the second net annual premium . Net annual premium is affected by amount of single premium and annuity due. De Moivre law is applied to calculate the reserve.

  19. Preliminary thermal and stress analysis of the SINQ window

    International Nuclear Information System (INIS)

    Heidenreich, G.

    1991-01-01

    Preliminary results of a finite element analysis for the SINQ proton beam window are presented. Temperatures and stresses are calculated in an axisymmetric model. As a result of these calculations, the H 2 O-cooled window (safety window) could be redesigned in such a way that plastic deformation resulting from excessive stress in some areas is avoided. (author)

  20. Mechanical stability of bentonite buffer system for high level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Lempinen, A. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Theoretical and Applied Mechanics

    1998-05-01

    According to present plans, high level nuclear waste in Finland is going to be disposed of in bedrock at a depth of several hundred metres. The spent fuel containers will be placed in boreholes drilled in the floors of deposition tunnels with engineered clay buffer, which is made of bentonite blocks. The tunnels will be filled with a mixture of bentonite and crushed rock. For stability calculations a thermomechanical model for compressed bentonite is needed. In the study a thermomechanically consistent model for reversible processes for swelling clays is presented. Preliminary calculations were performed and they show that uncertainty in material parameter values causes significantly different results. Therefore, measurements that are consistent with the model are needed 12 refs.

  1. Mechanical stability of bentonite buffer system for high level nuclear waste

    International Nuclear Information System (INIS)

    Lempinen, A.

    1998-05-01

    According to present plans, high level nuclear waste in Finland is going to be disposed of in bedrock at a depth of several hundred metres. The spent fuel containers will be placed in boreholes drilled in the floors of deposition tunnels with engineered clay buffer, which is made of bentonite blocks. The tunnels will be filled with a mixture of bentonite and crushed rock. For stability calculations a thermomechanical model for compressed bentonite is needed. In the study a thermomechanically consistent model for reversible processes for swelling clays is presented. Preliminary calculations were performed and they show that uncertainty in material parameter values causes significantly different results. Therefore, measurements that are consistent with the model are needed

  2. Magnetic Field Calculator

    Data.gov (United States)

    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,...

  3. Before Stabilization

    DEFF Research Database (Denmark)

    Plesner, Ursula; Horst, Maja

    2013-01-01

    of the communication about innovations in information and communication technology (ICT), and to contribute to an understanding of how different visions promise particular future configurations of workflows, communication processes, politics, economic models and social relations. Hereby, the paper adds...... to the literature on the relationship between ICTs and organizing, but with a distinct focus on innovation communication and distributed innovation processes taking place before ICTs are stabilized, issues which cannot be captured by studies of diffusion and adaptation of new ICTs within single organizations....

  4. MATLAB Stability and Control Toolbox Trim and Static Stability Module

    Science.gov (United States)

    Kenny, Sean P.; Crespo, Luis

    2012-01-01

    MATLAB Stability and Control Toolbox (MASCOT) utilizes geometric, aerodynamic, and inertial inputs to calculate air vehicle stability in a variety of critical flight conditions. The code is based on fundamental, non-linear equations of motion and is able to translate results into a qualitative, graphical scale useful to the non-expert. MASCOT was created to provide the conceptual aircraft designer accurate predictions of air vehicle stability and control characteristics. The code takes as input mass property data in the form of an inertia tensor, aerodynamic loading data, and propulsion (i.e. thrust) loading data. Using fundamental nonlinear equations of motion, MASCOT then calculates vehicle trim and static stability data for the desired flight condition(s). Available flight conditions include six horizontal and six landing rotation conditions with varying options for engine out, crosswind, and sideslip, plus three take-off rotation conditions. Results are displayed through a unique graphical interface developed to provide the non-stability and control expert conceptual design engineer a qualitative scale indicating whether the vehicle has acceptable, marginal, or unacceptable static stability characteristics. If desired, the user can also examine the detailed, quantitative results.

  5. Oxidative stability of marine phospholipids

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline Pascale

    Many studies have shown that marine phospholipids (MPL) provide more advantages than fish oil. They have better bioavailability, better resistance towards oxidation and higher content of eicosapentaenoic acids (EPA) and docosahexaenoic acids (DHA) than oily triglycerides (fish oil). The objective...... of this study is to investigate the oxidative and hydrolytic stability of MPL. In addition, this study also investigates the effect of chemical composition of MPL and Maillard reaction (interaction between lipids oxidation products with the residue of amino acids) on MPL emulsions’ stability. Firstly, MPL were...... was further investigated through measurement of secondary volatile compounds by Solid Phase Microextraction at several time intervals. On the other hand, the Maillard reaction was investigated through the measurement of color changes and pyrrole content before and after 32 days storage. Preliminary result...

  6. STABILITY SYSTEMS VIA HURWITZ POLYNOMIALS

    Directory of Open Access Journals (Sweden)

    BALTAZAR AGUIRRE HERNÁNDEZ

    2017-01-01

    Full Text Available To analyze the stability of a linear system of differential equations  ẋ = Ax we can study the location of the roots of the characteristic polynomial pA(t associated with the matrix A. We present various criteria - algebraic and geometric - that help us to determine where the roots are located without calculating them directly.

  7. Nonlinear stability of supersonic jets

    Science.gov (United States)

    Tiwari, S. N. (Principal Investigator); Bhat, T. R. S. (Principal Investigator)

    1996-01-01

    The stability calculations made for a shock-free supersonic jet using the model based on parabolized stability equations are presented. In this analysis the large scale structures, which play a dominant role in the mixing as well as the noise radiated, are modeled as instability waves. This model takes into consideration non-parallel flow effects and also nonlinear interaction of the instability waves. The stability calculations have been performed for different frequencies and mode numbers over a range of jet operating temperatures. Comparisons are made, where appropriate, with the solutions to Rayleigh's equation (linear, inviscid analysis with the assumption of parallel flow). The comparison of the solutions obtained using the two approaches show very good agreement.

  8. A Preliminary Investigation into the Stability of Inorganic Arsenic ...

    African Journals Online (AJOL)

    South African Journal of Chemistry. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 69 (2016) >. Log in or Register to get access to full text downloads.

  9. Preliminary results of MHD stability in HL-1 tokamak

    International Nuclear Information System (INIS)

    Zheng Yongzhen; Ma Tengcai; Xiao Zhenggui Cai Renfang

    1987-01-01

    In this paper, MHD activities of HL-1 tokamak plasma are studied with Fourier transform and correlatio analysis. The poloidal modes m = 1, 2, 3,4 and toroidal modes n of MHD magnetic fluctuation signals are detected. Methods for suppressing MHD instabilities are suggested and tested, after MHD instabilities are studied in HL-1. The effects of MHD characteristics in the beginning stage of discharge on the whole process of discharge are analyzed. The disruption, in HL-1 device could be divided into three kinds: internal disruption, minor disruption and major disruption. The result shows that HL-1 will have a better operation condition if internal disruption appears. In is end, the stable operation region of HL-1 tokamak is also given

  10. Linear Modeling of Rotorcraft for Stability Analysis and Preliminary Design

    Science.gov (United States)

    1993-09-01

    Bmat ) disp(’ ’) disp(’press any key to continue...’) pause clc elseif choice==4, V...lateral cyclic, pedal.]’) diap(’ ’) diup ( Bmat ) disp(’ ’) disp(’ ’) diup(’ Higenvalue’) diup(’ ’) diap (’Uncoupled’) diup(’ ’) disp(’Longitudinal plant...containing matrix variables V Amat Bmat Rcoup Flataug Glataug Rlataug Plataug Flataug % Glataug Rlonaug Plonaug ’a V * Configuring variables

  11. A Preliminary Investigation into the Stability of Inorganic Arsenic ...

    African Journals Online (AJOL)

    NICOLAAS

    tetraacetate (EDTA) and temperature was used to preserve speciation. Solutions were analyzed ... metal speciation, particularly with arsenic, prior to analysis is important to ..... plants: comparison of LC–ICP–MS and LC–ES–MS/ICP–MS with.

  12. CO2 flowrate calculator

    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

  13. Comparison of calculational methods for EBT reactor nucleonics

    International Nuclear Information System (INIS)

    Henninger, R.J.; Seed, T.J.; Soran, P.D.; Dudziak, D.J.

    1980-01-01

    Nucleonic calculations for a preliminary conceptual design of the first wall/blanket/shield/coil assembly for an EBT reactor are described. Two-dimensional Monte Carlo, and one- and two-dimensional discrete-ordinates calculations are compared. Good agreement for the calculated values of tritium breeding and nuclear heating is seen. We find that the three methods are all useful and complementary as a design of this type evolves

  14. Phase stabilities at a glance: Stability diagrams of nickel dipnictides

    International Nuclear Information System (INIS)

    Bachhuber, F.; Rothballer, J.; Weihrich, R.; Söhnel, T.

    2013-01-01

    In the course of the recent advances in chemical structure prediction, a straightforward type of diagram to evaluate phase stabilities is presented based on an expedient example. Crystal structures and energetic stabilities of dipnictides NiPn 2 (Pn = N, P, As, Sb, Bi) are systematically investigated by first principles calculations within the framework of density functional theory using the generalized gradient approximation to treat exchange and correlation. These dipnictides show remarkable polymorphism that is not yet understood systematically and offers room for the discovery of new phases. Relationships between the concerned structures including the marcasite, the pyrite, the arsenopyrite/CoSb 2 , and the NiAs 2 types are highlighted by means of common structural fragments. Electronic stabilities of experimentally known and related AB 2 structure types are presented graphically in so-called stability diagrams. Additionally, competing binary phases are taken into consideration in the diagrams to evaluate the stabilities of the title compounds with respect to decomposition. The main purpose of the stability diagrams is the introduction of an image that enables the estimation of phase stabilities at a single glance. Beyond that, some of the energetically favored structure types can be identified as potential new phases

  15. Hartree-Fock calculations of nuclear masses

    International Nuclear Information System (INIS)

    Quentin, P.

    1976-01-01

    Hartree-Fock calculations pertaining to the determination of nuclear binding energies throughout the whole chart of nuclides are reviewed. Such an approach is compared with other methods. Main techniques in use are shortly presented. Advantages and drawbacks of these calculations are also discussed with a special emphasis on the extrapolation towards nuclei far from the stability valley. Finally, a discussion of some selected results from light to superheavy nuclei, is given [fr

  16. Broyden's method in nuclear structure calculations

    International Nuclear Information System (INIS)

    Baran, Andrzej; Bulgac, Aurel; Forbes, Michael McNeil; Hagen, Gaute; Nazarewicz, Witold; Schunck, Nicolas; Stoitsov, Mario V.

    2008-01-01

    Broyden's method, widely used in quantum chemistry electronic-structure calculations for the numerical solution of nonlinear equations in many variables, is applied in the context of the nuclear many-body problem. Examples include the unitary gas problem, the nuclear density functional theory with Skyrme functionals, and the nuclear coupled-cluster theory. The stability of the method, its ease of use, and its rapid convergence rates make Broyden's method a tool of choice for large-scale nuclear structure calculations

  17. Computational Approach for Epitaxial Polymorph Stabilization through Substrate Selection

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Hong; Dwaraknath, Shyam S.; Garten, Lauren; Ndione, Paul; Ginley, David; Persson, Kristin A.

    2016-05-25

    With the ultimate goal of finding new polymorphs through targeted synthesis conditions and techniques, we outline a computational framework to select optimal substrates for epitaxial growth using first principle calculations of formation energies, elastic strain energy, and topological information. To demonstrate the approach, we study the stabilization of metastable VO2 compounds which provides a rich chemical and structural polymorph space. We find that common polymorph statistics, lattice matching, and energy above hull considerations recommends homostructural growth on TiO2 substrates, where the VO2 brookite phase would be preferentially grown on the a-c TiO2 brookite plane while the columbite and anatase structures favor the a-b plane on the respective TiO2 phases. Overall, we find that a model which incorporates a geometric unit cell area matching between the substrate and the target film as well as the resulting strain energy density of the film provide qualitative agreement with experimental observations for the heterostructural growth of known VO2 polymorphs: rutile, A and B phases. The minimal interfacial geometry matching and estimated strain energy criteria provide several suggestions for substrates and substrate-film orientations for the heterostructural growth of the hitherto hypothetical anatase, brookite, and columbite polymorphs. These criteria serve as a preliminary guidance for the experimental efforts stabilizing new materials and/or polymorphs through epitaxy. The current screening algorithm is being integrated within the Materials Project online framework and data and hence publicly available.

  18. Extrap interchange stability

    International Nuclear Information System (INIS)

    Scheffel, J.

    1989-05-01

    This is a non-linear MHD study of Extrap interchange stability. The closed-line stability criterion d(pgγ)/dψ ≥ 0 is used for fully 2-D numerical calculations of marginally stable equilibria. It is found that Extrap has a stabilzing effect on these modes. The reason for this is that q = Ιdl/B diverges towards the separatrix, which forms a boundary for the pinch. Consequently, in comparison with the 1-D Z-pinch, the Extrap octupole field allows steeper pressure profile in the boundary region. This stabilizing effect is shown to diminish in equilibria with an externally imposed axial magnetic field. It is also shown how the shape of the plasma cross-section depends on the relative direction of plasma current and external rod currents, when the current density j is finite on the boundary. Unfavourable curvature and higher values of j at the boundary are obtained in the case of parallel currents. Only when j vanishes at the separatrix, the cross-section can be truly square-shaped. The type of singularity of q at the separatrix is derived, as well as criteria for j to become singular

  19. Aircraft nonlinear stability analysis and multidimensional stability region estimation under icing conditions

    Directory of Open Access Journals (Sweden)

    Liang QU

    2017-06-01

    Full Text Available Icing is one of the crucial factors that could pose great threat to flight safety, and thus research on stability and stability region of aircraft safety under icing conditions is significant for control and flight. Nonlinear dynamical equations and models of aerodynamic coefficients of an aircraft are set up in this paper to study the stability and stability region of the aircraft under an icing condition. Firstly, the equilibrium points of the iced aircraft system are calculated and analyzed based on the theory of differential equation stability. Secondly, according to the correlation theory about equilibrium points and the stability region, this paper estimates the multidimensional stability region of the aircraft, based on which the stability regions before and after icing are compared. Finally, the results are confirmed by the time history analysis. The results can give a reference for stability analysis and envelope protection of the nonlinear system of an iced aircraft.

  20. Structural analysis of salt cavities formed by solution mining: I. Method of analysis and preliminary results for spherical cavities

    International Nuclear Information System (INIS)

    Fossum, A.F.

    1976-01-01

    The primary objective of this effort is an analysis of the structural stability of cavities formed by solution mining in salt domes. In particular, the effects of depth (i.e. initial state of in situ stress), shape, volume (i.e. physical dimensions of the cavity), and sequence of salt excavation/fluid evacuation on the timewise structural stability of a cavity are of interest. It is anticipated that an assessment can be made of the interrelation between depth, cavern size, and cavern shape or of the practical limits therewith. In general, the cavity shape is assumed to be axisymmetric and the salt is assumed to exhibit nonlinear creep behavior. The primary emphasis is placed on the methodology of the finite element analysis, and the results of preliminary calculations for a spherically shaped cavity. It is common practice for engineers to apply elasticity theory to the behavior of rock in order to obtain near field stresses and displacements around an underground excavation in an effort to assess structural stability. Rock masses, particularly at depth, may be subjected to a rather complex state of initial stress, and may be nonhomogeneous and anisotropic. If one also includes complex geometrical excavation shape, the use of analytical techniques as an analysis tool is practically impossible. Thus, it is almost a necessity that approximate solution techniques be employed. In this regard, the finite element method is ideal as it can handle complex geometries and nonlinear material behavior with relative ease. An unusual feature of the present study is the incorporation into the finite element code of a procedure for handling the gradual creation or excavation of an underground cavity. During the excavation sequence, the salt is permitted to exhibit nonlinear stress-strain-time dependence. The bulk of this report will be devoted to a description of the analysis procedures, together with a preliminary calculation for a spherically shaped cavity

  1. FUEL HANDLING FACILITY BACKUP CENTRAL COMMUNICATIONS ROOM SPACE REQUIREMENTS CALCULATION

    International Nuclear Information System (INIS)

    SZALEWSKI, B.

    2005-01-01

    The purpose of the Fuel Handling Facility Backup Central Communications Room Space Requirements Calculation is to determine a preliminary estimate of the space required to house the backup central communications room in the Fuel Handling Facility (FHF). This room provides backup communications capability to the primary communication systems located in the Central Control Center Facility. This calculation will help guide FHF designers in allocating adequate space for communications system equipment in the FHF. This is a preliminary calculation determining preliminary estimates based on the assumptions listed in Section 4. As such, there are currently no limitations on the use of this preliminary calculation. The calculations contained in this document were developed by Design and Engineering and are intended solely for the use of Design and Engineering in its work regarding the FHF Backup Central Communications Room Space Requirements. Yucca Mountain Project personnel from Design and Engineering should be consulted before the use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Design and Engineering

  2. Adjoint electron Monte Carlo calculations

    International Nuclear Information System (INIS)

    Jordan, T.M.

    1986-01-01

    Adjoint Monte Carlo is the most efficient method for accurate analysis of space systems exposed to natural and artificially enhanced electron environments. Recent adjoint calculations for isotropic electron environments include: comparative data for experimental measurements on electronics boxes; benchmark problem solutions for comparing total dose prediction methodologies; preliminary assessment of sectoring methods used during space system design; and total dose predictions on an electronics package. Adjoint Monte Carlo, forward Monte Carlo, and experiment are in excellent agreement for electron sources that simulate space environments. For electron space environments, adjoint Monte Carlo is clearly superior to forward Monte Carlo, requiring one to two orders of magnitude less computer time for relatively simple geometries. The solid-angle sectoring approximations used for routine design calculations can err by more than a factor of 2 on dose in simple shield geometries. For critical space systems exposed to severe electron environments, these potential sectoring errors demand the establishment of large design margins and/or verification of shield design by adjoint Monte Carlo/experiment

  3. 46 CFR 174.360 - Calculations.

    Science.gov (United States)

    2010-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO SPECIFIC VESSEL TYPES Special Rules Pertaining to Dry Cargo Ships § 174.360 Calculations. Each ship to... for that ship by the International Convention for the Safety of Life at Sea, 1974, as amended, chapter...

  4. Test Room Stability Plan

    International Nuclear Information System (INIS)

    1993-01-01

    This plan documents the combination of designs, installations, programs, and activities that ensures that the underground excavations at the Waste Isolation Pilot Plant (WIPP), in which transuranic (TRU) waste may be emplaced during the Test Phase, will remain sufficiently stable and safe during that time. The current ground support systems installed at the WIPP are the result of over ten years of data collection from hundreds of geomechanical instruments and thousands of hours of direct observation of the changing conditions of the openings. In addition, some of the world's most respected experts on salt rock mechanics have provided input in the design process and concurrence on the suitability of the final design. The general mine rockbolt pattern and the ground support system for the test rooms are designed to specifically address the fracture and deformation geometries observed today at the WIPP. After an introductory chapter, this plan describes the general underground design, then proceeds to an account of general ground support performance, and finally focuses on the details of the special test room ground support systems. One such system already installed in Room 1, Panel 1, is described in comprehensive detail. Other test rooms in Panel 1, whether full-size or smaller, will be equipped with systems that ensure stability to the same or equivalent extent. They will benefit from the experience gained in the first test room, which in turn benefitted from the data and knowledge accumulated during previous stages (e.g., the Site and Preliminary Design Validation program) of the project

  5. Feasibility study on embedded transport core calculations

    International Nuclear Information System (INIS)

    Ivanov, B.; Zikatanov, L.; Ivanov, K.

    2007-01-01

    The main objective of this study is to develop an advanced core calculation methodology based on embedded diffusion and transport calculations. The scheme proposed in this work is based on embedded diffusion or SP 3 pin-by-pin local fuel assembly calculation within the framework of the Nodal Expansion Method (NEM) diffusion core calculation. The SP 3 method has gained popularity in the last 10 years as an advanced method for neutronics calculation. NEM is a multi-group nodal diffusion code developed, maintained and continuously improved at the Pennsylvania State University. The developed calculation scheme is a non-linear iteration process, which involves cross-section homogenization, on-line discontinuity factors generation, and boundary conditions evaluation by the global solution passed to the local calculation. In order to accomplish the local calculation, a new code has been developed based on the Finite Elements Method (FEM), which is capable of performing both diffusion and SP 3 calculations. The new code will be used in the framework of the NEM code in order to perform embedded pin-by-pin diffusion and SP 3 calculations on fuel assembly basis. The development of the diffusion and SP 3 FEM code is presented first following by its application to several problems. Description of the proposed embedded scheme is provided next as well as the obtained preliminary results of the C3 MOX benchmark. The results from the embedded calculations are compared with direct pin-by-pin whole core calculations in terms of accuracy and efficiency followed by conclusions made about the feasibility of the proposed embedded approach. (authors)

  6. Heterogeneous Calculation of {epsilon}

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Alf

    1961-02-15

    A heterogeneous method of calculating the fast fission factor given by Naudet has been applied to the Carlvik - Pershagen definition of {epsilon}. An exact calculation of the collision probabilities is included in the programme developed for the Ferranti - Mercury computer.

  7. Heterogeneous Calculation of ε

    International Nuclear Information System (INIS)

    Jonsson, Alf

    1961-02-01

    A heterogeneous method of calculating the fast fission factor given by Naudet has been applied to the Carlvik - Pershagen definition of ε. An exact calculation of the collision probabilities is included in the programme developed for the Ferranti - Mercury computer

  8. Comparison of Calculation Models for Bucket Foundation in Sand

    DEFF Research Database (Denmark)

    Vaitkunaite, Evelina; Molina, Salvador Devant; Ibsen, Lars Bo

    The possibility of fast and rather precise preliminary offshore foundation design is desirable. The ultimate limit state of bucket foundation is investigated using three different geotechnical calculation tools: [Ibsen 2001] an analytical method, LimitState:GEO and Plaxis 3D. The study has focused...... on resultant bearing capacity of variously embedded foundation in sand. The 2D models, [Ibsen 2001] and LimitState:GEO can be used for the preliminary design because they are fast and result in a rather similar bearing capacity calculation compared with the finite element models of Plaxis 3D. The 2D models...

  9. Hamming generalized corrector for reactivity calculation

    International Nuclear Information System (INIS)

    Suescun-Diaz, Daniel; Ibarguen-Gonzalez, Maria C.; Figueroa-Jimenez, Jorge H.

    2014-01-01

    This work presents the Hamming method generalized corrector for numerically resolving the differential equation of delayed neutron precursor concentration from the point kinetics equations for reactivity calculation, without using the nuclear power history or the Laplace transform. A study was carried out of several correctors with their respective modifiers with different time step calculations, to offer stability and greater precision. Better results are obtained for some correctors than with other existing methods. Reactivity can be calculated with precision of the order h 5 , where h is the time step. (orig.)

  10. The friction of polymers around Tg,Tm : Preliminary results

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V N; Persson, B N J

    We present Molecular Dynamics calculations involving polymers of different lengths. Polymers with lengths from 20 to 1400 carbon atoms are considered. The systems are able to simulate friction between polymer surfaces and polymer against metal. The results we present are very preliminary and they......We present Molecular Dynamics calculations involving polymers of different lengths. Polymers with lengths from 20 to 1400 carbon atoms are considered. The systems are able to simulate friction between polymer surfaces and polymer against metal. The results we present are very preliminary...

  11. Preliminary hazards analysis -- vitrification process

    International Nuclear Information System (INIS)

    Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P.

    1994-06-01

    This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility's construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment

  12. Preliminary hazards analysis -- vitrification process

    Energy Technology Data Exchange (ETDEWEB)

    Coordes, D.; Ruggieri, M.; Russell, J.; TenBrook, W.; Yimbo, P. [Science Applications International Corp., Pleasanton, CA (United States)

    1994-06-01

    This paper presents a Preliminary Hazards Analysis (PHA) for mixed waste vitrification by joule heating. The purpose of performing a PHA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PHA is then followed by a Preliminary Safety Analysis Report (PSAR) performed during Title 1 and 2 design. The PSAR then leads to performance of the Final Safety Analysis Report performed during the facility`s construction and testing. It should be completed before routine operation of the facility commences. This PHA addresses the first four chapters of the safety analysis process, in accordance with the requirements of DOE Safety Guidelines in SG 830.110. The hazards associated with vitrification processes are evaluated using standard safety analysis methods which include: identification of credible potential hazardous energy sources; identification of preventative features of the facility or system; identification of mitigative features; and analyses of credible hazards. Maximal facility inventories of radioactive and hazardous materials are postulated to evaluate worst case accident consequences. These inventories were based on DOE-STD-1027-92 guidance and the surrogate waste streams defined by Mayberry, et al. Radiological assessments indicate that a facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous materials assessment indicates that a Mixed Waste Vitrification facility will be a Low Hazard facility having minimal impacts to offsite personnel and the environment.

  13. Geochemical analysis of the sealing system. Technical Report to work package 9.1.2. Preliminary safety case of the Gorleben site (VSG)

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Mingliang; Herbert, Horst-Juergen

    2012-02-15

    The geochemical reaction simulation of ground water and brines with sealing materials for a proposed repository at the Gorleben site is a task under the framework of the VSG project. The calculations presented in this report are aimed to provide a preliminary evaluation of the geochemical stability of three potential engineering barrier materials foreseen in the shaft sealing system in case of groundwater and brine intrusion. The long-term stability of these materials is a key issue for the sealing function of the shaft seals. This is governed by many factors such as geotechnical, hydraulic and geochemical processes. In order to better understand the potential effect of geochemical processes on the long-term properties of these sealing materials, geochemical simulations of the potential interactions between groundwater and brine and shaft sealing materials were performed.

  14. Desenvolvimento e estudos de estabilidade preliminares de emulsões O/A contendo Cetoconazol 2,0% - DOI: 10.4025/actascihealthsci.v30i2.812 Development and Preliminary Stability Evaluations of O/W emulsion containing Ketoconazole 2.0% - DOI: 10.4025/actascihealthsci.v30i2.812

    Directory of Open Access Journals (Sweden)

    Márcio Augusto Leite de Campos

    2008-12-01

    Full Text Available O objetivo deste trabalho foi desenvolver emulsões O/A contendo Cetoconazol 2,0% e avaliar sua estabilidade preliminar por meio da análise de suas características físico-químicas, tais como homogeneidade, formação de agregados, floculação, cremeação e coalescência. As emulsões foram formuladas utilizando diferentes bases autoemulsionantes, compostas por álcool cetoestearílico, álcool etoxilado, álcool graxos superiores, ácido esteárico, lanolina e outros. As emulsões foram submetidas aos testes de centrifugação, estresse térmico e ciclo gela-degela, e suas características organolépticas e físico-químicas foram avaliadas no início e no final de cada ensaio. Todas as amostras mantiveram sua homogeneidade após o teste de centrifugação, mas somente os sistemas preparados com ceras autoemulsionáveis constituídas por álcool graxos superiores (Polawax NF® e Copolímero de Amônio Acriloil dimetiltaurato VP, Trilauril 4 fosfato, Sesquisosterato de metil glicose, Óleo de flores de verão e Tetradibutil pentaeritritil hidroxihidrocinamato de Glicerina (Hostacerin NCB® ; mantiveram sua estabilidade após testes de estresse térmico e ciclo gela-degelaThe objective of this work was the development of O/W emulsions containing Ketoconazole 2.0% and to evaluate their preliminary stability by analyzing physical-chemical characteristics such as homogeneity, aggregation formation, flocculation, creaming and coalescence. The emulsions were formulated using different self-emulsifying bases, composed of cetearyl alcohol, ethoxyl alcohol, higher fatty alcohol, stearic acid, lanolin and others. The O/W emulsions were evaluated by centrifugation test, thermal stress test, and freezing/defrosting cycles, and its organoleptic and physical-chemistry characteristics were analyzed before and after each assay. All samples maintained their homogeneity after the centrifugation test, but only the systems prepared with self emulsifying

  15. UVISS preliminary visibility analysis

    DEFF Research Database (Denmark)

    Betto, Maurizio

    1998-01-01

    The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part of the w......The goal of this work is to obtain a preliminary assessment of the sky visibility for anastronomical telescope located on the express pallet of the International SpaceStation (ISS)} taking into account the major constraints imposed on the instrument by the ISSattitude and structure. Part...... of the work is also to setup the kernel of a software tool for the visibility analysis thatshould be easily expandable to consider more complex strucures for future activities.This analysis is part of the UVISS assessment study and it is meant to provide elementsfor the definition and the selection...

  16. Antares: preliminary demonstrator results

    International Nuclear Information System (INIS)

    Kouchner, A.

    2000-05-01

    The ANTARES collaboration is building an undersea neutrino telescope off Toulon (Mediterranean sea) with effective area ∼ 0.1 km 2 . An extensive study of the site properties has been achieved together with software analysis in order to optimize the performance of the detector. Results are summarized here. An instrumented line, linked to shore for first time via an electro-optical cable, has been immersed late 1999. The preliminary results of this demonstrator line are reported. (author)

  17. Core calculations of JMTR

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Yoshiharu [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    In material testing reactors like the JMTR (Japan Material Testing Reactor) of 50 MW in Japan Atomic Energy Research Institute, the neutron flux and neutron energy spectra of irradiated samples show complex distributions. It is necessary to assess the neutron flux and neutron energy spectra of an irradiation field by carrying out the nuclear calculation of the core for every operation cycle. In order to advance core calculation, in the JMTR, the application of MCNP to the assessment of core reactivity and neutron flux and spectra has been investigated. In this study, in order to reduce the time for calculation and variance, the comparison of the results of the calculations by the use of K code and fixed source and the use of Weight Window were investigated. As to the calculation method, the modeling of the total JMTR core, the conditions for calculation and the adopted variance reduction technique are explained. The results of calculation are shown. Significant difference was not observed in the results of neutron flux calculations according to the difference of the modeling of fuel region in the calculations by K code and fixed source. The method of assessing the results of neutron flux calculation is described. (K.I.)

  18. Experiments on the stability of metal diapirs

    Science.gov (United States)

    Wacheul, J. S.; Le Bars, M.; Aurnou, J. M.; Monteux, J.

    2013-12-01

    In the late stages of their accretions, telluric planets had most likely had a magma ocean because of numerous heat sources such as the important decay of radioactive elements and giant impacts. These giant impacts involved asteroid nearly as big as the moon, which were certainly differentiated. The core of these planetary embryos ultimately merged with the planets, but the amount of heat and chemicals they exchanged with the mantle during its passing through remains a widely open question. The question of the stability of an immiscible iron diapir falling through a magma ocean is essential for our understanding of these events. Thus, we have conducted the first experiments on an analogue system that involves liquid metal; we used liquid gallium as the melted iron and glycerol as the magma ocean. This set up allowed us to reach Reynolds numbers closer to the geophysical problem than other previous studies and accurate viscosity ratios. Using video analysis, we reconstruct the spectra of droplet sizes and velocities, from which we calculate a typical length of equilibration as a function of the diapir's radius. Our preliminary results are in agreement with the scenario of the iron rain concerning the droplet sizes, with a significant influence of the viscosity ratio on the maximal size of the droplets. However, the speed of these droplets seems to be controlled by the inertia of the whole flow in a sense that the relevant concept for the mixing between metal and silicate is turbulent mixing between miscible fluids. The influence of coalescence between droplets on this mixing, involving a significant part of the flow according to our experiment, is still to be quantified.

  19. Development of a Plastic Stabilizer for the M865 Training Projectile

    National Research Council Canada - National Science Library

    Garner, James

    1999-01-01

    .... This preliminary stabilizer (flare) is made from polyetheretherketone (PEEK) and is expected to handle the in-bore and out-of-bore aerothermal environments sufficiently to conform to the performance of the present M865 flare...

  20. Electronics Environmental Benefits Calculator

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Electronics Environmental Benefits Calculator (EEBC) was developed to assist organizations in estimating the environmental benefits of greening their purchase,...

  1. Electrical installation calculations basic

    CERN Document Server

    Kitcher, Christopher

    2013-01-01

    All the essential calculations required for basic electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practice. A step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3Fo

  2. Electrical installation calculations advanced

    CERN Document Server

    Kitcher, Christopher

    2013-01-01

    All the essential calculations required for advanced electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practiceA step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3For apprentices and electrical installatio

  3. Radar Signature Calculation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The calculation, analysis, and visualization of the spatially extended radar signatures of complex objects such as ships in a sea multipath environment and...

  4. Waste Package Lifting Calculation

    International Nuclear Information System (INIS)

    H. Marr

    2000-01-01

    The objective of this calculation is to evaluate the structural response of the waste package during the horizontal and vertical lifting operations in order to support the waste package lifting feature design. The scope of this calculation includes the evaluation of the 21 PWR UCF (pressurized water reactor uncanistered fuel) waste package, naval waste package, 5 DHLW/DOE SNF (defense high-level waste/Department of Energy spent nuclear fuel)--short waste package, and 44 BWR (boiling water reactor) UCF waste package. Procedure AP-3.12Q, Revision 0, ICN 0, calculations, is used to develop and document this calculation

  5. Dimensional stability of natural fibers

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Mark S. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 (United States); Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 and Sustainable Construction Management and Engineering, SUNY-ESF (United States); Larsen, L. Scott [New York State Energy Research and Development Authority (NYSERDA), 17 Columbia Circle, Albany, NY 12203 (United States)

    2013-04-19

    One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

  6. Dimensional stability of natural fibers

    International Nuclear Information System (INIS)

    Driscoll, Mark S.; Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J.; Larsen, L. Scott

    2013-01-01

    One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

  7. SPECIES DIVERSITY AND STABILITY OF BIRD COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Matsyura M.V.

    2011-12-01

    Full Text Available When comparing the suggested stability indicators, we obtained statistically significant correlations for indicators of annual stability of species and total number and standard deviation of the logarithm of the number. Annual Stability Index can be applied with a high degree of reliability as a characteristic of the averaged structure of the community and its pyramid of abundances. The results of correlation analysis confirm our assumptions about the correlation between stability over the years and indices of species diversity and relative uniformity.The final task of the study was to create a mathematical model of stability, where the independent variables are the indices of species diversity. The calculation of these indices allows forecasting birds’ community stability. According to the result of multiple regression for the indicators of diversity and stability of the breeding birds’ community highest correlation coefficients were obtained fro Shannon index and Simpson's dominance Index.Community stability could be determined by its overall species diversity. When considering the stability of community its diversity should be considered as a combination of uniformity of their total number and number of species. The most suitable predictors for the community stability were the nonparametric index of dominance and information-statistical indices, since they considered simultaneously evenness and richness. The community stability is subject of the complexity of its internal communications pattern.

  8. Methods for Melting Temperature Calculation

    Science.gov (United States)

    Hong, Qi-Jun

    the melting temperature is a design criterion. We present in detail two examples of refractory materials. First, we demonstrate how key material properties that provide guidance in the design of refractory materials can be accurately determined via ab initio thermodynamic calculations in conjunction with experimental techniques based on synchrotron X-ray diffraction and thermal analysis under laser-heated aerodynamic levitation. The properties considered include melting point, heat of fusion, heat capacity, thermal expansion coefficients, thermal stability, and sublattice disordering, as illustrated in a motivating example of lanthanum zirconate (La2Zr2O7). The close agreement with experiment in the known but structurally complex compound La2Zr 2O7 provides good indication that the computation methods described can be used within a computational screening framework to identify novel refractory materials. Second, we report an extensive investigation into the melting temperatures of the Hf-C and Hf-Ta-C systems using ab initio calculations. With melting points above 4000 K, hafnium carbide (HfC) and tantalum carbide (TaC) are among the most refractory binary compounds known to date. Their mixture, with a general formula TaxHf 1-xCy, is known to have a melting point of 4215 K at the composition Ta4HfC 5, which has long been considered as the highest melting temperature for any solid. Very few measurements of melting point in tantalum and hafnium carbides have been documented, because of the obvious experimental difficulties at extreme temperatures. The investigation lets us identify three major chemical factors that contribute to the high melting temperatures. Based on these three factors, we propose and explore a new class of materials, which, according to our ab initio calculations, may possess even higher melting temperatures than Ta-Hf-C. This example also demonstrates the feasibility of materials screening and discovery via ab initio calculations for the

  9. PFP total operating efficiency calculation and basis of estimate

    International Nuclear Information System (INIS)

    SINCLAIR, J.C.

    1999-01-01

    The purpose of the Plutonium Finishing Plant (PFP) Total Operating Efficiency Calculation and Basis of Estimate document is to provide the calculated value and basis of estimate for the Total Operating Efficiency (TOE) for the material stabilization operations to be conducted in 234-52 Building. This information will be used to support both the planning and execution of the Plutonium Finishing Plant (PFP) Stabilization and Deactivation Project's (hereafter called the Project) resource-loaded, integrated schedule

  10. Secular stability of rotating stars

    International Nuclear Information System (INIS)

    Imamura, J.N.; Friedman, J.L.; Durisen, R.H.

    1984-01-01

    In this work, we calculate the secular stability limits of rotating polytropes to nonaxisymmetric perturbations of low m. We consider polytropic indices ranging from 1 to 3 and several angular momentum distributions. Results are most conveniently presented in terms of the t-parameter, defined as the ratio of the rotational kinetic energy to the absolute value of the gravitational energy of the fluid. Previous work on polytropes considered only the m = 2 mode, which is unstable for values of the t-parameter greater than 0.14 +- 0.01 for the n values n = 1.5 and 3 and the angular momentum distributions tested (see Durisen and Imamura 1981). The GRR secular stability limit of the m = 2 mode for the Maclaurin spheroids (n = O) was determined by Chandrasekhar (1970). GRR stability limits of higher m modes for the Maclaurin spheroids were located approximately by Comins (1979a,b) and more precisely by Friedman (1983)

  11. Nuclear astrophysics away from stability

    International Nuclear Information System (INIS)

    Mathews, G.J.; Howard, W.M.; Takahashi, K.; Ward, R.A.

    1985-08-01

    Explosive astrophysical environments invariably lead to the production of nuclei away from stability. An understanding of the dynamics and nucleosynthesis in such environments is inextricably coupled to an understanding of the properties of the synthesized nuclei. In this talk a review is presented of the basic explosive nucleosynthesis mechanisms (s-process, r-process, n-process, p-process, and rp-process). Specific stellar model calculations are discussed and a summary of the pertinent nuclear data is presented. Possible experiments and nuclear-model calculations are suggested that could facilitate a better understanding of the astrophysical scenarios. 39 refs., 4 figs

  12. PWR core design calculations

    International Nuclear Information System (INIS)

    Trkov, A.; Ravnik, M.; Zeleznik, N.

    1992-01-01

    Functional description of the programme package Cord-2 for PWR core design calculations is presented. Programme package is briefly described. Use of the package and calculational procedures for typical core design problems are treated. Comparison of main results with experimental values is presented as part of the verification process. (author) [sl

  13. 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

  14. Stabilization of superconducting dry solenoids

    International Nuclear Information System (INIS)

    Urata, M.; Maeda, H.

    1989-01-01

    Premature quenches in superconducting solenoids, wound with Formvar coated NbTi conductors, have been studied. Some model coils were tested wound with various winding tensions. The experimental results are discussed considering the calculated stress distribution for coil winding, cool-down to liquid helium temperature, and energization at 4.2 K. /Some mechanisms of premature quenches are classified by the winding tension. Some stabilization methods are presented based on these quench mechanisms

  15. Phase stability in yttria-stabilized zirconia from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Carbogno, Christian; Scheffler, Matthias [Materials Department, University of California, Santa Barbara, CA (United States); Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin (Germany); Levi, Carlos G.; Van de Walle, Chris G. [Materials Department, University of California, Santa Barbara, CA (United States)

    2012-07-01

    Zirconia based ceramics are of pivotal importance for a variety of industrial technologies, e.g., for thermal barrier coatings in gas and airplane turbines. Naturally, the stability of such coatings at elevated temperatures plays a critical role in these applications. It is well known that an aliovalent doping of tetragonal ZrO{sub 2} with yttria, which induces oxygen vacancies due to charge conservation, increases its thermodynamic stability. However, the atomistic mechanisms that determine the phase stability of such yttria-stabilized Zirconia (YSZ) coatings are not yet fully understood. In this work, we use density functional theory calculations to assess the electronic structure of the different YSZ polymorphs at various levels of doping. With the help of population analysis schemes, we are able to unravel the intrinsic mechanisms that govern the interaction in YSZ and that can so explain the relative stabilities of the various polymorphs. We critically compare our results to experimental measurements and discuss the implications of our findings with respect to other oxides.

  16. The hydrodynamics of accretion discs. Pt. 1,2. Stability. Turbulent models

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J

    1975-08-01

    The disc is idealized to be a stationary axisymmetric toroidal flow of a compressible fluid. The stability against linearized short wavelength perturbations is discussed. When the Rayleigh and Schwarzschild criteria are satisfied, the flow is stable against axisymmetric perturbations. However, almost all non-axisymmetric perturbations are not secularly stable, and examples of dynamically unstable modes are given. For turbulent models, two new points are made. The crucial problem for the horizontal structure of the disc, the prescription of the Reynolds stress gradient, is resolved by a direct calculation from first principles. A preliminary attempt is also made to describe the vertical structure, leading to a sandwich model. The predictions of this theory are shown to be consistent with the fine scale structure of Cyg X-1. (DE)

  17. Environmental Survey preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    1988-04-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy (DOE) Sandia National Laboratories conducted August 17 through September 4, 1987. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with Sandia National Laboratories-Albuquerque (SNLA). The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at SNLA, and interviews with site personnel. 85 refs., 49 figs., 48 tabs.

  18. Ruiz Volcano: Preliminary report

    Science.gov (United States)

    Ruiz Volcano, Colombia (4.88°N, 75.32°W). All times are local (= GMT -5 hours).An explosive eruption on November 13, 1985, melted ice and snow in the summit area, generating lahars that flowed tens of kilometers down flank river valleys, killing more than 20,000 people. This is history's fourth largest single-eruption death toll, behind only Tambora in 1815 (92,000), Krakatau in 1883 (36,000), and Mount Pelée in May 1902 (28,000). The following briefly summarizes the very preliminary and inevitably conflicting information that had been received by press time.

  19. Efeito da equoterapia na estabilidade postural de portadores de esclerose múltipla: estudo preliminar Efecto de la hipoterapia en la estabilidad postural de portadores de esclerosis múltiple: estudio preliminar Effect of hippotherapy on the postural stability of patients with multiple sclerosis: a preliminary study

    Directory of Open Access Journals (Sweden)

    Karla Mendonça Menezes

    2013-03-01

    Full Text Available OBJETIVO: Este estudo se propôs a verificar se a estimulação por meio da equoterapia é capaz de desencadear alterações no controle postural de portadores de esclerose múltipla (EM. MÉTODO: Fizeram parte deste estudo 11 portadores de EM divididos em Grupo Intervenção (GI e Grupo Controle (GC. O GI foi inserido num programa de hipoterapia durante 4 meses, sendo conduzidas 2 sessões semanais com duração de 50 minutos cada. A estabilidade postural foi avaliada utilizando uma plataforma de força (para calcular o deslocamento do centro de pressão (COP, durante 30 segundos, em postura ereta quasi-estática, com olhos abertos e fechados, antes e após o treinamento com equoterapia. O tratamento estatístico foi feito através do ANOVA e Post hoc de Tukey com pOBJETIVO: El objetivo de éste estudio fue identificar los efectos de la hipoterapia sobre el control postural en pacientes con esclerosis múltiple (EM. MÉTODO: Hicieron parte de este estudio 11 portadores de EM divididos en Grupo Intervención (GI y Grupo Control (GC. El GI fue insertado en un programa de hipoterapia durante cuatro meses, siendo realizadas dos sesiones semanales con duración de 50 minutos cada una. La estabilidad postural fue evaluada utilizando una plataforma de fuerza (para calcular el desplazamiento del centro de presión (COP, durante 30 segundos en postura erecta casi-estática, con ojos abiertos y cerrados, antes y después del entrenamiento con hipoterapia. El tratamiento estadístico fue realizado a través de ANOVA y Post hoc de Tukey con pOBJECTIVE: This study intended to identify the effects of hippotherapy on the postural control of multiple sclerosis (MS patients. METHODS: Eleven MS patients were separated into two groups: Intervention Group (IG and Control Group (CG. Hippotherapy consisted of two 50-minute sessions each week for four months. Postural stability was evaluated before and after hippotherapy using a force plate to calculate the center of

  20. Cryostatic stability equation

    International Nuclear Information System (INIS)

    Sydoriak, S.G.

    1976-01-01

    Although criteria for cryostatic stability of superconducting magnets cooled by pool boiling of liquid helium have been widely discussed the same cannot be said for magnets cooled by natural convection or forced flow boiling in channels. Boiling in narrow channels is shown to be qualitatively superior to pool boiling because the recovery heat flux equals the breakaway flux for narrow channels, whereas the two are markedly different in pool boiling. A second advantage of channel boiling is that it is well understood and calculable; pool peak nucleate boiling heat flux has been adequately measured only for boiling from the top of an immersed heated body. Peak boiling from the bottom is much less and (probably) depends strongly on the extent of the bottom surface. Equations are presented by which one can calculate the critical boiling heat flux for parallel wall vertical channels subject to either natural convection or forced flow boiling, with one or both walls heated. The one-heated-wall forced flow equation is discussed with regard to design of a spiral wound solenoid (pancake magnet) having a slippery insulating tape between the windings

  1. Hydrocode subcycling stability

    International Nuclear Information System (INIS)

    Hicks, D.L.

    1981-01-01

    The method of artificial viscosity was originally designed by von Neumann and Richtmyer for calculating the propagation of waves in materials that were hydrodynamic and rate-independent (e.g., ideal gas law). However, hydrocodes (such as WONDY) based on this method continue to expand their repertoire of material laws even unto material laws that are rate-dependent (e.g., Maxwell's material law). Restrictions on the timestep required for stability with material laws that are rate-dependent can be considerably more severe than restrictions of the Courant-Friedrichs-Lewy (CFL) type that are imposed in these hydrocodes. These very small timesteps can make computations very expensive. An alternative is to go ahead and integrate the conservation laws with the usual CFL timestep while subcycling (integrating with a smaller timestep) the integration of the stress-rate equation. If the subcycling is done with a large enough number of subcycles (i.e., with a small enough subcycle timestep), then the calculation is stable. Specifically, the number of subcycles must be one greater than the ratio of the CFL timestep to the relaxation time of the material

  2. Dose calculation for electrons

    International Nuclear Information System (INIS)

    Hirayama, Hideo

    1995-01-01

    The joint working group of ICRP/ICRU is advancing the works of reviewing the ICRP publication 51 by investigating the data related to radiation protection. In order to introduce the 1990 recommendation, it has been demanded to carry out calculation for neutrons, photons and electrons. As for electrons, EURADOS WG4 (Numerical Dosimetry) rearranged the data to be calculated at the meeting held in PTB Braunschweig in June, 1992, and the question and request were presented by Dr. J.L. Chartier, the responsible person, to the researchers who are likely to undertake electron transport Monte Carlo calculation. The author also has carried out the requested calculation as it was the good chance to do the mutual comparison among various computation codes regarding electron transport calculation. The content that the WG requested to calculate was the absorbed dose at depth d mm when parallel electron beam enters at angle α into flat plate phantoms of PMMA, water and ICRU4-element tissue, which were placed in vacuum. The calculation was carried out by the versatile electron-photon shower computation Monte Carlo code, EGS4. As the results, depth dose curves and the dependence of absorbed dose on electron energy, incident angle and material are reported. The subjects to be investigated are pointed out. (K.I.)

  3. Power distribution effects on boiling water reactor stability

    International Nuclear Information System (INIS)

    Damiano, B.; March-Leuba, J.

    1989-01-01

    The work presented in this paper deals with the effects of spatial power distributions on the stability of boiling water reactors (BWRs). It is shown that a conservative power distribution exists for which the stability is minimal. These results are relevant because they imply that bounding stability calculations are possible and, thus, a worst-possible scenario may be defined for a particular BWR geometry. These bounding calculations may, then, be used to determine the maximum expected limit-cycle peak powers

  4. Plutonium inventories for stabilization and stabilized materials

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.K.

    1996-05-01

    The objective of the breakout session was to identify characteristics of materials containing plutonium, the need to stabilize these materials for storage, and plans to accomplish the stabilization activities. All current stabilization activities are driven by the Defense Nuclear Facilities Safety Board Recommendation 94-1 (May 26, 1994) and by the recently completed Plutonium ES&H Vulnerability Assessment (DOE-EH-0415). The Implementation Plan for accomplishing stabilization of plutonium-bearing residues in response to the Recommendation and the Assessment was published by DOE on February 28, 1995. This Implementation Plan (IP) commits to stabilizing problem materials within 3 years, and stabilizing all other materials within 8 years. The IP identifies approximately 20 metric tons of plutonium requiring stabilization and/or repackaging. A further breakdown shows this material to consist of 8.5 metric tons of plutonium metal and alloys, 5.5 metric tons of plutonium as oxide, and 6 metric tons of plutonium as residues. Stabilization of the metal and oxide categories containing greater than 50 weight percent plutonium is covered by DOE Standard {open_quotes}Criteria for Safe Storage of Plutonium Metals and Oxides{close_quotes} December, 1994 (DOE-STD-3013-94). This standard establishes criteria for safe storage of stabilized plutonium metals and oxides for up to 50 years. Each of the DOE sites and contractors with large plutonium inventories has either started or is preparing to start stabilization activities to meet these criteria.

  5. Trapped particle stability for the kinetic stabilizer

    Science.gov (United States)

    Berk, H. L.; Pratt, J.

    2011-08-01

    A kinetically stabilized axially symmetric tandem mirror (KSTM) uses the momentum flux of low-energy, unconfined particles that sample only the outer end-regions of the mirror plugs, where large favourable field-line curvature exists. The window of operation is determined for achieving magnetohydrodynamic (MHD) stability with tolerable energy drain from the kinetic stabilizer. Then MHD stable systems are analysed for stability of the trapped particle mode. This mode is characterized by the detachment of the central-cell plasma from the kinetic-stabilizer region without inducing field-line bending. Stability of the trapped particle mode is sensitive to the electron connection between the stabilizer and the end plug. It is found that the stability condition for the trapped particle mode is more constraining than the stability condition for the MHD mode, and it is challenging to satisfy the required power constraint. Furthermore, a severe power drain may arise from the necessary connection of low-energy electrons in the kinetic stabilizer to the central region.

  6. Large scale GW calculations

    International Nuclear Information System (INIS)

    Govoni, Marco; Argonne National Lab., Argonne, IL; Galli, Giulia; Argonne National Lab., Argonne, IL

    2015-01-01

    We present GW calculations of molecules, ordered and disordered solids and interfaces, which employ an efficient contour deformation technique for frequency integration and do not require the explicit evaluation of virtual electronic states nor the inversion of dielectric matrices. We also present a parallel implementation of the algorithm, which takes advantage of separable expressions of both the single particle Green's function and the screened Coulomb interaction. The method can be used starting from density functional theory calculations performed with semilocal or hybrid functionals. The newly developed technique was applied to GW calculations of systems of unprecedented size, including water/semiconductor interfaces with thousands of electrons

  7. Radioactive cloud dose calculations

    International Nuclear Information System (INIS)

    Healy, J.W.

    1984-01-01

    Radiological dosage principles, as well as methods for calculating external and internal dose rates, following dispersion and deposition of radioactive materials in the atmosphere are described. Emphasis has been placed on analytical solutions that are appropriate for hand calculations. In addition, the methods for calculating dose rates from ingestion are discussed. A brief description of several computer programs are included for information on radionuclides. There has been no attempt to be comprehensive, and only a sampling of programs has been selected to illustrate the variety available

  8. Fluorescein isothiocyanate: Molecular characterization by theoretical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Casanovas, Jordi [Departament de Quimica, Escola Politecnica Superior, Universitat de Lleida, c/Jaume II No 69, Lleida E-25001 (Spain); Jacquemin, Denis [Laboratoire de Chimie Theorique Appliquee, Facultes Universitaires Notre-Dame de la Paix, rue de Bruxelles, 61, B-5000 Namur (Belgium)], E-mail: denis.jacquemin@fundp.ac.be; Perpete, Eric A. [Laboratoire de Chimie Theorique Appliquee, Facultes Universitaires Notre-Dame de la Paix, rue de Bruxelles, 61, B-5000 Namur (Belgium); Aleman, Carlos [Departament d' Enginyeria Quimica, E. T. S. d' Enginyeria Industrial de Barcelona, Universitat Politecnica de Catalunya, Diagonal 647, Barcelona E-08028 (Spain)], E-mail: carlos.aleman@upc.edu

    2008-12-10

    Quantum mechanical calculations have been used to investigate the conformation, molecular geometry, basicity and spectroscopic properties of fluorescein isothiocyanate in both the gas-phase and aqueous solution. Specifically, calculations have been performed considering the neutral, monoanionic and dianionic forms of this important fluorescent compound. Results reveal that for the neutral form multiple conformational states are possible, all them with significant contributions, and the stability of the different conformers is similar in the gas-phase and aqueous solution. Calculation of the excitation energies revealed that spectroscopic properties are very sensitive to the relaxation effect in solution. A good agreement has been reached obtained between the experimental and theoretical values derived from time-dependent density functional theory methods for the neutral form, whereas for charged species the calculations fail to accurately reproduce the measured trends.

  9. Active vibration suppression of helicopter horizontal stabilizers

    Science.gov (United States)

    Cinquemani, Simone; Cazzulani, Gabriele; Resta, Ferruccio

    2017-04-01

    Helicopters are among the most complex machines ever made. While ensuring high performance from the aeronautical point of view, they are not very comfortable due to vibration mainly created by the main rotor and by the interaction with the surrounding air. One of the most solicited structural elements of the vehicle are the horizontal stabilizers. These elements are particularly stressed because of their composite structure which, while guaranteeing lightness and strength, is characterized by a low damping. This work makes a preliminary analysis on the dynamics of the structure and proposes different solutions to actively suppress vibrations. Among them, the best in terms of the relationship between performance and weight / complexity of the system is that based on inertial actuators mounted on the inside of the horizontal stabilizers. The work addresses the issue of the design of the device and its use in the stabilizer from both the numerical and the experimental points of view.

  10. Devoluming and stabilizing method for end piece

    International Nuclear Information System (INIS)

    Ikeda, Satoshi; Shiotsuki, Msao; Kawamura, Shigeyoshi; Komatsu, Fumiaki.

    1991-01-01

    As a first method, end pieces and other radioactive metal wastes are filled as a mixture in a vessel, and preliminary compression is conducted. Then, the bulk density of the radioactive metal wastes is reduced and gaps in the end pieces are filled with radioactive metal wastes. If they are applied with heat treatment under high pressure in this state together with the vessel, they are devolumed and stabilized without damaging the vessel. As a second method, metal powders are mixed and filled in the vessel together with the end pieces. The gaps in the end pieces are filled with the metal powders and if they are applied with heat treatment under high pressure in this state together with the vessel, the end pieces are devolumed and stabilized without damaging the vessel in the same manner. This can devolume and stabilize the end pieces separated from nuclear fuel assemblies easily and safely. (T.M.)

  11. OMEGA Upgrade preliminary design

    International Nuclear Information System (INIS)

    Craxton, R.S.

    1989-10-01

    The OMEGA laser system at the Laboratory for Laser Energetics of the University of Rochester is the only major facility in the United States capable of conducting fully diagnosed, direct-drive, spherical implosion experiments. As such, it serves as the national Laser Users Facility, benefiting scientists throughout the country. The University's participation in the National Inertial Confinement Fusion (ICF) program underwent review by a group of experts under the auspices of the National Academy of Sciences (the Happer Committee) in 1985. The Happer Committee recommended that the OMEGA laser be upgraded in energy to 30 kJ. To this end, Congress appropriated $4,000,000 for the preliminary design of the OMEGA Upgrade, spread across FY88 and FY89. This document describes the preliminary design of the OMEGA Upgrade. The proposed enhancements to the existing OMEGA facility will result in a 30-kHJ, 351-nm, 60-beam direct-drive system, with a versatile pulse-shaping facility and a 1%--2% uniformity of target drive. The Upgrade will allow scientists to explore the ignition-scaling regime, and to study target behavior that is hydrodynamically equivalent to that of targets appropriate for a laboratory microfusion facility (LMF). In addition, it will be possible to perform critical interaction experiments with large-scale-length uniformly irradiated plasmas

  12. Labview virtual instruments for calcium buffer calculations.

    Science.gov (United States)

    Reitz, Frederick B; Pollack, Gerald H

    2003-01-01

    Labview VIs based upon the calculator programs of Fabiato and Fabiato (J. Physiol. Paris 75 (1979) 463) are presented. The VIs comprise the necessary computations for the accurate preparation of multiple-metal buffers, for the back-calculation of buffer composition given known free metal concentrations and stability constants used, for the determination of free concentrations from a given buffer composition, and for the determination of apparent stability constants from absolute constants. As implemented, the VIs can concurrently account for up to three divalent metals, two monovalent metals and four ligands thereof, and the modular design of the VIs facilitates further extension of their capacity. As Labview VIs are inherently graphical, these VIs may serve as useful templates for those wishing to adapt this software to other platforms.

  13. Handout on shielding calculation

    International Nuclear Information System (INIS)

    Heilbron Filho, P.F.L.

    1991-01-01

    In order to avoid the difficulties of the radioprotection supervisors in the tasks related to shielding calculations, is presented in this paper the basic concepts of shielding theory. It also includes exercises and examples. (author)

  14. Unit Cost Compendium Calculations

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Unit Cost Compendium (UCC) Calculations raw data set was designed to provide for greater accuracy and consistency in the use of unit costs across the USEPA...

  15. PHYSICOCHEMICAL PROPERTY CALCULATIONS

    Science.gov (United States)

    Computer models have been developed to estimate a wide range of physical-chemical properties from molecular structure. The SPARC modeling system approaches calculations as site specific reactions (pKa, hydrolysis, hydration) and `whole molecule' properties (vapor pressure, boilin...

  16. Magnetic Field Grid Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Properties Calculator will computes the estimated values of Earth's magnetic field(declination, inclination, vertical component, northerly...

  17. Intercavitary implants dosage calculation

    International Nuclear Information System (INIS)

    Rehder, B.P.

    The use of spacial geometry peculiar to each treatment for the attainment of intercavitary and intersticial implants dosage calculation is presented. The study is made in patients with intercavitary implants by applying a modified Manchester technique [pt

  18. Casio Graphical Calculator Project.

    Science.gov (United States)

    Stott, Nick

    2001-01-01

    Shares experiences of a project aimed at developing and refining programs written on a Casio FX9750G graphing calculator. Describes in detail some programs used to develop mental strategies and problem solving skills. (MM)

  19. Small portable speed calculator

    Science.gov (United States)

    Burch, J. L.; Billions, J. C.

    1973-01-01

    Calculator is adapted stopwatch calibrated for fast accurate measurement of speeds. Single assembled unit is rugged, self-contained, and relatively inexpensive to manufacture. Potential market includes automobile-speed enforcement, railroads, and field-test facilities.

  20. Calculativeness and trust

    DEFF Research Database (Denmark)

    Frederiksen, Morten

    2014-01-01

    Williamson’s characterisation of calculativeness as inimical to trust contradicts most sociological trust research. However, a similar argument is found within trust phenomenology. This paper re-investigates Williamson’s argument from the perspective of Løgstrup’s phenomenological theory of trust....... Contrary to Williamson, however, Løgstrup’s contention is that trust, not calculativeness, is the default attitude and only when suspicion is awoken does trust falter. The paper argues that while Williamson’s distinction between calculativeness and trust is supported by phenomenology, the analysis needs...... to take actual subjective experience into consideration. It points out that, first, Løgstrup places trust alongside calculativeness as a different mode of engaging in social interaction, rather conceiving of trust as a state or the outcome of a decision-making process. Secondly, the analysis must take...

  1. Activities for Calculators.

    Science.gov (United States)

    Hiatt, Arthur A.

    1987-01-01

    Ten activities that give learners in grades 5-8 a chance to explore mathematics with calculators are provided. The activity cards involve such topics as odd addends, magic squares, strange projects, and conjecturing rules. (MNS)

  2. IRIS core criticality calculations

    International Nuclear Information System (INIS)

    Jecmenica, R.; Trontl, K.; Pevec, D.; Grgic, D.

    2003-01-01

    Three-dimensional Monte Carlo computer code KENO-VI of CSAS26 sequence of SCALE-4.4 code system was applied for pin-by-pin calculations of the effective multiplication factor for the first cycle IRIS reactor core. The effective multiplication factors obtained by the above mentioned Monte Carlo calculations using 27-group ENDF/B-IV library and 238-group ENDF/B-V library have been compared with the effective multiplication factors achieved by HELIOS/NESTLE, CASMO/SIMULATE, and modified CORD-2 nodal calculations. The results of Monte Carlo calculations are found to be in good agreement with the results obtained by the nodal codes. The discrepancies in effective multiplication factor are typically within 1%. (author)

  3. Laboratory-performance criteria for in situ waste-stabilization materials

    International Nuclear Information System (INIS)

    Shaw, P.; Weidner, J.

    1996-01-01

    The Department of Energy (DOE) Landfill Stabilization Focus Area is investigating a variety of in situ placement methods, grout materials, and characterization techniques for the stabilization of buried low-level transuranic-contaminated waste at Department of Energy sites. In situ stabilization involves underground injection or placement of substances to isolate, treat, or contain buried contaminants. Performance criteria were developed to evaluate various candidate stabilization materials for both long-term stabilization and interim stabilization or retrieval. The criteria are go/no-go, ready, and preliminary. The criterion go/no-go eliminates technologies that are not applicable for in situ treatment of buried waste. The criterion ready indicates that the technology is sufficiently developed and proven to be field demonstrated full-scale. The criterion preliminary indicates the prospective technologies to be potentially applicable to in situ buried waste stabilization, but further development is needed before the technology is ready for field-scale demonstration

  4. Calculation program development for spinning reserve

    International Nuclear Information System (INIS)

    1979-01-01

    This study is about optimal holding of spinning reserve and optimal operation for it. It deals with the purpose and contents of the study, introduction of the spinning reserve electricity, speciality of the spinning reserve power, the result of calculation, analysis for limited method of optimum load, calculation of requirement for spinning reserve, analysis on measurement of system stability with summary, purpose of the analysis, cause of impact of the accident, basics on measurement of spinning reserve and conclusion. It has the reference on explanation for design of spinning reserve power program and using and trend about spinning reserve power in Korea.

  5. Current interruption transients calculation

    CERN Document Server

    Peelo, David F

    2014-01-01

    Provides an original, detailed and practical description of current interruption transients, origins, and the circuits involved, and how they can be calculated Current Interruption Transients Calculationis a comprehensive resource for the understanding, calculation and analysis of the transient recovery voltages (TRVs) and related re-ignition or re-striking transients associated with fault current interruption and the switching of inductive and capacitive load currents in circuits. This book provides an original, detailed and practical description of current interruption transients, origins,

  6. Source and replica calculations

    International Nuclear Information System (INIS)

    Whalen, P.P.

    1994-01-01

    The starting point of the Hiroshima-Nagasaki Dose Reevaluation Program is the energy and directional distributions of the prompt neutron and gamma-ray radiation emitted from the exploding bombs. A brief introduction to the neutron source calculations is presented. The development of our current understanding of the source problem is outlined. It is recommended that adjoint calculations be used to modify source spectra to resolve the neutron discrepancy problem

  7. Shielding calculations using FLUKA

    International Nuclear Information System (INIS)

    Yamaguchi, Chiri; Tesch, K.; Dinter, H.

    1988-06-01

    The dose equivalent on the surface of concrete shielding has been calculated using the Monte Carlo code FLUKA86 for incident proton energies from 10 to 800 GeV. The results have been compared with some simple equations. The value of the angular dependent parameter in Moyer's equation has been calculated from the locations where the values of the maximum dose equivalent occur. (author)

  8. Engineering Judgment and Natural Circulation Calculations

    OpenAIRE

    Ferreri, J. C.

    2011-01-01

    The analysis performed to establish the validity of computer code results in the particular field of natural circulation flow stability calculations is presented in the light of usual engineering practice. The effects of discretization and closure correlations are discussed and some hints to avoid undesired mistakes in the evaluations performed are given. Additionally, the results are presented for an experiment relevant to the way in which a (small) number of skilled, nuclear safety analysts...

  9. Characteristics of thermal hydraulic stability in a HYPER system with enhanced natural circulation potential

    International Nuclear Information System (INIS)

    Tak, Nam Il; Park, Won S.; Han, Seok Jung

    1999-06-01

    Pb-Bi eutectic chosen as a coolant of HYPER is an excellent heat transfer medium but requires relatively large pumping power. Thus the mixed cooling concept to increase economy and safety is being considered for HYPER. In this cooling concept, a large fraction of total thermal power is carried by natural circulation. However, the mixed cooling concept has been considered for conceptual designs only an it has never been applied to real reactors. The purpose of the present study is to provide simple tools to analyze mixed flow and to examine fundamental stability characteristics of mixed flow. Conventional one-dimensional approaches using mass, momentum, and energy conservation are used to describe a forced circulating flow affected by a large buoyancy force. The results of simple analysis using preliminary design parameters of HYPER show that cooling by mixed flow is possible only when the total pressure loss of system is sufficiently low. The stability behavior of mixed flow in a simple rectangular loop has been studied using numerical solutions of the governing equations. As in the case of natural circulation, three types of flow regions, such as stable, neutrally stable, and unstable regions, were found. The stability map of mixed flow has been obtained using the results of calculations. Forced flow due to the pump is found to increase the stability of the loop, since the stable portion of the stability map is increased. However, the unstable region of the mixed flow does not completely disappear, even though the pump exists. (author). 37 refs., 4 tabs., 23 figs

  10. Application of backtracking algorithm to depletion calculations

    International Nuclear Information System (INIS)

    Wu Mingyu; Wang Shixi; Yang Yong; Zhang Qiang; Yang Jiayin

    2013-01-01

    Based on the theory of linear chain method for analytical depletion calculations, the burnup matrix is decoupled by the divide and conquer strategy and the linear chain with Markov characteristic is formed. The density, activity and decay heat of every nuclide in the chain then can be calculated by analytical solutions. Every possible reaction path of the nuclide must be considered during the linear chain establishment process. To confirm the calculation precision and efficiency, the algorithm which can cover all the reaction paths and search the paths automatically according to the problem description and precision restrictions should be found. Through analysis and comparison of several kinds of searching algorithms, the backtracking algorithm was selected to establish and calculate the linear chains in searching process using depth first search (DFS) method, forming an algorithm which can solve the depletion problem adaptively and with high fidelity. The complexity of the solution space and time was analyzed by taking into account depletion process and the characteristics of the backtracking algorithm. The newly developed depletion program was coupled with Monte Carlo program MCMG-Ⅱ to calculate the benchmark burnup problem of the first core of China Experimental Fast Reactor (CEFR) and the preliminary verification and validation of the program were performed. (authors)

  11. CALCULATION ALGORITHM TRUSS UNDER CRANE BEAMS

    Directory of Open Access Journals (Sweden)

    N. K. Akaev1

    2016-01-01

    Full Text Available Aim.The task of reducing the deflection and increase the rigidity of single-span beams are made. In the article the calculation algorithm for truss crane girders is determined.Methods. To identify the internal effort required for the selection of cross section elements the design uses the Green's function.Results. It was found that the simplest truss system reduces deflection and increases the strength of design. The upper crossbar is subjected not only to bending and shear and compression work due to tightening tension. Preliminary determination of the geometrical characteristics of the crane farms elements are offered to make a comparison with previous similar configuration of his farms, using a simple approximate calculation methods.Conclusion.The method of sequential movements (incrementally the two bridge cranes along the length of the upper crossbar truss beams is suggested. We give the corresponding formulas and conditions of safety.

  12. The Effect of Political Stability on Public Education Quality

    Science.gov (United States)

    Nir, Adam E.; Kafle, Bhojraj Sharma

    2013-01-01

    Purpose: The purpose of this paper is to provide a preliminary analysis to evaluate the implications of political stability for educational quality, evident in the survival rate measure. Design/methodology/approach: Secondary analyses were conducted for data drawn from the Political Risk Service Report, the World Bank Report, the United Nations…

  13. Interferometric system for PM-level stability characterization

    NARCIS (Netherlands)

    Verlaan, A.L.; Ellis, J.D.; Voigt, D.; Spronck, J.W.; Munnig Schmidt, R.H.

    2010-01-01

    We present a double sided, single pass Michelson heterodyne interferometer for dimensional stability measurements. In preliminary measurements, the double deadpath configuration (no sample) showed better than ±1.5 nm (2/) over 13 hours. A 30 mm stainless gauge block was then measured with a

  14. Uncertainty calculations made easier

    International Nuclear Information System (INIS)

    Hogenbirk, A.

    1994-07-01

    The results are presented of a neutron cross section sensitivity/uncertainty analysis performed in a complicated 2D model of the NET shielding blanket design inside the ITER torus design, surrounded by the cryostat/biological shield as planned for ITER. The calculations were performed with a code system developed at ECN Petten, with which sensitivity/uncertainty calculations become relatively simple. In order to check the deterministic neutron transport calculations (performed with DORT), calculations were also performed with the Monte Carlo code MCNP. Care was taken to model the 2.0 cm wide gaps between two blanket segments, as the neutron flux behind the vacuum vessel is largely determined by neutrons streaming through these gaps. The resulting neutron flux spectra are in excellent agreement up to the end of the cryostat. It is noted, that at this position the attenuation of the neutron flux is about 1 l orders of magnitude. The uncertainty in the energy integrated flux at the beginning of the vacuum vessel and at the beginning of the cryostat was determined in the calculations. The uncertainty appears to be strongly dependent on the exact geometry: if the gaps are filled with stainless steel, the neutron spectrum changes strongly, which results in an uncertainty of 70% in the energy integrated flux at the beginning of the cryostat in the no-gap-geometry, compared to an uncertainty of only 5% in the gap-geometry. Therefore, it is essential to take into account the exact geometry in sensitivity/uncertainty calculations. Furthermore, this study shows that an improvement of the covariance data is urgently needed in order to obtain reliable estimates of the uncertainties in response parameters in neutron transport calculations. (orig./GL)

  15. Defining resilience: A preliminary integrative literature review

    Science.gov (United States)

    Wilt, Bonnie; Long, Suzanna K.; Shoberg, Thomas G.

    2016-01-01

    The term “resilience” is ubiquitous in technical literature; it appears in numerous forms, such as resilience, resiliency, or resilient, and each use may have a different definition depending on the interpretation of the writer. This creates difficulties in understanding what is meant by ‘resilience’ in any given use case, especially in discussions of interdisciplinary research. To better understand this problem, this research constructs a preliminary integrative literature review to map different definitions, applications and calculation methods of resilience invoked within critical infrastructure applications. The preliminary review uses a State-of-the-Art Matrix (SAM) analysis to characterize differences in definition across disciplines and between regions. Qualifying the various usages of resilience will produce a greater precision in the literature and a deeper insight into types of data required for its evaluation, particularly with respect to critical infrastructure calculations and how such data may be analyzed. Results from this SAM analysis will create a framework of key concepts as part of the most common applications for “resilient critical infrastructure” modeling.

  16. Preliminary rail access study

    International Nuclear Information System (INIS)

    1990-01-01

    The Yucca Mountain site, located on the southwestern edge of the Nevada Test Site, is an undeveloped area under investigation as a potential site for nuclear waste disposal by the US Department of Energy. The site currently lacks rail service and an existing rail right-of-way. If the site is suitable and selected for development as a disposal site, rail service is desirable to the Office of Civilian Radioactive Waste Management Program because of the potential of rail to reduce number of shipments and costs relative to highway transportation. This preliminary report is a summary of progress to date for activities to identify and evaluate potential rail options from major rail carriers in the region to the Yucca Mountain site. It is currently anticipated that the rail spur will be operational after the year 2000. 9 refs., 13 figs., 2 tabs

  17. Online plasma calculator

    Science.gov (United States)

    Wisniewski, H.; Gourdain, P.-A.

    2017-10-01

    APOLLO is an online, Linux based plasma calculator. Users can input variables that correspond to their specific plasma, such as ion and electron densities, temperatures, and external magnetic fields. The system is based on a webserver where a FastCGI protocol computes key plasma parameters including frequencies, lengths, velocities, and dimensionless numbers. FastCGI was chosen to overcome security problems caused by JAVA-based plugins. The FastCGI also speeds up calculations over PHP based systems. APOLLO is built upon the WT library, which turns any web browser into a versatile, fast graphic user interface. All values with units are expressed in SI units except temperature, which is in electron-volts. SI units were chosen over cgs units because of the gradual shift to using SI units within the plasma community. APOLLO is intended to be a fast calculator that also provides the user with the proper equations used to calculate the plasma parameters. This system is intended to be used by undergraduates taking plasma courses as well as graduate students and researchers who need a quick reference calculation.

  18. Stability constants of scandium complexes, 1

    International Nuclear Information System (INIS)

    Itoh, Hisako; Itoh, Naomi; Suzuki, Yasuo

    1984-01-01

    The stability constants of scandium complexes with some carboxylate ligands were determined potentiometrically at 25.0 and 40.0 0 C and at an ionic strength of 0.10 with potassium nitrate as supporting electrolyte. The constants of the scandium complexes were appreciably greater than those of the corresponding lanthanoid complexes, as expected. The changes in free energy, enthalpy, and entropy for the formation of the scandium complexes were calculated from the stability constants at two temperatures. (author)

  19. Dynamic Stability Experiment of Maglev Systems,

    Science.gov (United States)

    1995-04-01

    This report summarizes the research performed on maglev vehicle dynamic stability at Argonne National Laboratory during the past few years. It also... maglev system, it is important to consider this phenomenon in the development of all maglev systems. This report presents dynamic stability experiments...on maglev systems and compares their numerical simulation with predictions calculated by a nonlinear dynamic computer code. Instabilities of an

  20. Daylight calculations in practice

    DEFF Research Database (Denmark)

    Iversen, Anne; Roy, Nicolas; Hvass, Mette

    The aim of the project was to obtain a better understanding of what daylight calculations show and also to gain knowledge of how the different daylight simulation programs perform compared with each other. Experience has shown that results for the same room, obtained from two daylight simulation...... programs can give different results. This can be due to restrictions in the program itself and/or be due to the skills of the persons setting up the models. This is crucial as daylight calculations are used to document that the demands and recommendations to daylight levels outlined by building authorities....... The aim of the project was to obtain a better understanding of what daylight calculations show and also to gain knowledge of how the different daylight simulation programs perform compared with each other. Furthermore the aim was to provide knowledge of how to build up the 3D models that were...

  1. Calculating Quenching Weights

    CERN Document Server

    Salgado, C A; Salgado, Carlos A.; Wiedemann, Urs Achim

    2003-01-01

    We calculate the probability (``quenching weight'') that a hard parton radiates an additional energy fraction due to scattering in spatially extended QCD matter. This study is based on an exact treatment of finite in-medium path length, it includes the case of a dynamically expanding medium, and it extends to the angular dependence of the medium-induced gluon radiation pattern. All calculations are done in the multiple soft scattering approximation (Baier-Dokshitzer-Mueller-Peign\\'e-Schiff--Zakharov ``BDMPS-Z''-formalism) and in the single hard scattering approximation (N=1 opacity approximation). By comparison, we establish a simple relation between transport coefficient, Debye screening mass and opacity, for which both approximations lead to comparable results. Together with this paper, a CPU-inexpensive numerical subroutine for calculating quenching weights is provided electronically. To illustrate its applications, we discuss the suppression of hadronic transverse momentum spectra in nucleus-nucleus colli...

  2. Ship design methodologies of preliminary design

    CERN Document Server

    Papanikolaou, Apostolos

    2014-01-01

    This book deals with ship design and in particular with methodologies of the preliminary design of ships. The book is complemented by a basic bibliography and five appendices with useful updated charts for the selection of the main dimensions and other basic characteristics of different types of ships (Appendix A), the determination of hull form  from the data of systematic hull form series (Appendix B), the detailed description of the relational method for the preliminary estimation of ship weights (Appendix C), a brief review of the historical evolution of shipbuilding science and technology from the prehistoric era to date (Appendix D) and finally a historical review of regulatory developments of ship's damage stability to date (Appendix E).  The book can be used as textbook for ship design courses or as additional reading for university or college students of naval architecture courses and related disciplines; it may also serve as a reference book for naval architects, practicing engineers of rel...

  3. Fission neutron multiplicity calculations

    International Nuclear Information System (INIS)

    Maerten, H.; Ruben, A.; Seeliger, D.

    1991-01-01

    A model for calculating neutron multiplicities in nuclear fission is presented. It is based on the solution of the energy partition problem as function of mass asymmetry within a phenomenological approach including temperature-dependent microscopic energies. Nuclear structure effects on fragment de-excitation, which influence neutron multiplicities, are discussed. Temperature effects on microscopic energy play an important role in induced fission reactions. Calculated results are presented for various fission reactions induced by neutrons. Data cover the incident energy range 0-20 MeV, i.e. multiple chance fission is considered. (author). 28 refs, 13 figs

  4. Lattice cell burnup calculation

    International Nuclear Information System (INIS)

    Pop-Jordanov, J.

    1977-01-01

    Accurate burnup prediction is a key item for design and operation of a power reactor. It should supply information on isotopic changes at each point in the reactor core and the consequences of these changes on the reactivity, power distribution, kinetic characters, control rod patterns, fuel cycles and operating strategy. A basic stage in the burnup prediction is the lattice cell burnup calculation. This series of lectures attempts to give a review of the general principles and calculational methods developed and applied in this area of burnup physics

  5. PWR core design calculations

    Energy Technology Data Exchange (ETDEWEB)

    Trkov, A; Ravnik, M; Zeleznik, N [Inst. Jozef Stefan, Ljubljana (Slovenia)

    1992-07-01

    Functional description of the programme package Cord-2 for PWR core design calculations is presented. Programme package is briefly described. Use of the package and calculational procedures for typical core design problems are treated. Comparison of main results with experimental values is presented as part of the verification process. (author) [Slovenian] Opisali smo programski paket CORD-2, ki se uporablja pri projektnih izracunih sredice pri upravljanju tlacnovodnega reaktorja. Prikazana je uporaba paketa in racunskih postopkov za tipicne probleme, ki nastopajo pri projektiranju sredice. Primerjava glavnih rezultatov z eksperimentalnimi vrednostmi je predstavljena kot del preveritvenega procesa. (author)

  6. A new calculation of atmospheric neutrino flux: the FLUKA approach

    International Nuclear Information System (INIS)

    Battistoni, G.; Bloise, C.; Cavalli, D.; Ferrari, A.; Montaruli, T.; Rancati, T.; Resconi, S.; Ronga, F.; Sala, P.R.

    1999-01-01

    Preliminary results from a full 3-D calculation of atmospheric neutrino fluxes using the FLUKA interaction model are presented and compared to previous existing calculations. This effort is motivated mainly by the 3-D capability and the satisfactory degree of accuracy of the hadron-nucleus models embedded in the FLUKA code. Here we show examples of benchmarking tests of the model with cosmic ray experiment results. A comparison of our calculation of the atmospheric neutrino flux with that of the Bartol group, for E ν > 1 GeV, is presented

  7. Three dimensions transport calculations for PWR core

    International Nuclear Information System (INIS)

    Richebois, E.

    2000-01-01

    The objective of this work is to define improved 3-D core calculation methods based on the transport theory. These methods can be particularly useful and lead to more precise computations in areas of the core where anisotropy and steep flux gradients occur, especially near interface and boundary conditions and in regions of high heterogeneity (bundle with absorbent rods). In order to apply the transport theory a new method for calculating reflector constants has been developed, since traditional methods were only suited for 2-group diffusion core calculations and could not be extrapolated to transport calculations. In this thesis work, the new method for obtaining reflector constants is derived regardless of the number of energy groups and of the operator used. The core calculations results using the reflector constants thereof obtained have been validated on the EDF's power reactor Saint Laurent B1 with MOX loading. The advantages of a 3-D core transport calculation scheme have been highlighted as opposed to diffusion methods; there are a considerable number of significant effects and potential advantages to be gained in rod worth calculations for instance. These preliminary results obtained with on particular cycle will have to be confirmed by more systematic analysis. Accidents like MSLB (main steam line break) and LOCA (loss of coolant accident) should also be investigated and constitute challenging situations where anisotropy is high and/or flux gradients are steep. This method is now being validated for others EDF's PWRs' reactors, as well as for experimental reactors and other types of commercial reactors. (author)

  8. Spectrum stabilizer; Stabilisateur de spectres

    Energy Technology Data Exchange (ETDEWEB)

    Detourne, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires, Departement d' electronique generale, Service d' instrumentation nucleaire

    1967-05-01

    A spectrum stabilizer is a control mechanism which renders an analytical chain reliable. It can detect a drift in the amplification and in the base of the energy scale, and can modify the characteristics of this chain. The results of a theoretical study make it possible to calculate the width and the abscissae of the peaks of a stabilized spectrum as a function of the drifts. The SPECTROSTAB is a numerical stabilizer of a continuous type; it provides the artificial reference peak at low energies. Experimental results give the performances obtained on a reference peak provided by a semi-conductor detector, in the field of gamma spectroscopy. (author) [French] Un stabilisateur de spectres est un asservissement qui permet de rendre fidele une cha e d'analyse. Il detecte les derives du gain et de l'origine de l'echelle des energies et reagit sur les caracteristiques de cette cha e. Les resultats d'une etude theorique permettent le calcul des elargissements et des abscisses des pics d'un spectre stabilise, en fonction des derives. Le SPECTROSTAB est un stabilisateur numerique du genre continu; il fournit le pic de reference artificiel aux basses energies. Des resultats experimentaux donnent les performances obtenues sur un pic de reference fourni par un detecteur a semi-conducteur, dans le domaine de la spectrometrie gamma. (auteur)

  9. Stability analysis of free piston Stirling engines

    Science.gov (United States)

    Bégot, Sylvie; Layes, Guillaume; Lanzetta, François; Nika, Philippe

    2013-03-01

    This paper presents a stability analysis of a free piston Stirling engine. The model and the detailed calculation of pressures losses are exposed. Stability of the machine is studied by the observation of the eigenvalues of the model matrix. Model validation based on the comparison with NASA experimental results is described. The influence of operational and construction parameters on performance and stability issues is exposed. The results show that most parameters that are beneficial for machine power seem to induce irregular mechanical characteristics with load, suggesting that self-sustained oscillations could be difficult to maintain and control.

  10. Stability analysis of zigzag boron nitride nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Hari Mohan, E-mail: rai.2208@gmail.com; Late, Ravikiran; Saxena, Shailendra K.; Kumar, Rajesh; Sagdeo, Pankaj R. [Indian Institute of Technology, Indore –452017 (India); Jaiswal, Neeraj K. [Discipline of Physics, PDPM- Indian Institute of Information Technology, Design and Manufacturing, Jabalpur – 482005 (India); Srivastava, Pankaj [Computational Nanoscience and Technology Lab. (CNTL), ABV- Indian Institute of Information Technology and Management, Gwalior – 474015 (India)

    2015-05-15

    We have explored the structural stability of bare and hydrogenated zigzag boron nitride nanoribbons (ZBNNRs). In order to investigate the structural stability, we calculate the cohesive energy for bare, one-edge and both edges H-terminated ZBNNRs with different widths. It is found that the ZBNNRs with width Nz=8 are energetically more favorable than the lower-width counterparts (Nz<8). Bare ZBNNRs have been found energetically most stable as compared to the edge terminated ribbons. Our analysis reveals that the structural stability is a function of ribbon-width and it is not affected significantly by the type of edge-passivation (one-edge or both-edges)

  11. Asymptotic stability of a catalyst particle

    DEFF Research Database (Denmark)

    Wedel, Stig; Michelsen, Michael L.; Villadsen, John

    1977-01-01

    The catalyst asymptotic stability problem is studied by means of several new methods that allow accurate solutions to be calculated where other methods have given qualitatively erroneous results. The underlying eigenvalue problem is considered in three limiting situations Le = ∞, 1 and 0. These a......The catalyst asymptotic stability problem is studied by means of several new methods that allow accurate solutions to be calculated where other methods have given qualitatively erroneous results. The underlying eigenvalue problem is considered in three limiting situations Le = ∞, 1 and 0...

  12. Calculating Student Grades.

    Science.gov (United States)

    Allswang, John M.

    1986-01-01

    This article provides two short microcomputer gradebook programs. The programs, written in BASIC for the IBM-PC and Apple II, provide statistical information about class performance and calculate grades either on a normal distribution or based on teacher-defined break points. (JDH)

  13. Cardiovascular risk calculation

    African Journals Online (AJOL)

    James A. Ker

    2014-08-20

    Aug 20, 2014 ... smoking and elevated blood sugar levels (diabetes mellitus). These risk ... These are risk charts, e.g. FRS, a non-laboratory-based risk calculation, and ... for hard cardiovascular end-points, such as coronary death, myocardial ...

  14. Cooling tower calculations

    International Nuclear Information System (INIS)

    Simonkova, J.

    1988-01-01

    The problems are summed up of the dynamic calculation of cooling towers with forced and natural air draft. The quantities and relations are given characterizing the simultaneous exchange of momentum, heat and mass in evaporative water cooling by atmospheric air in the packings of cooling towers. The method of solution is clarified in the calculation of evaporation criteria and thermal characteristics of countercurrent and cross current cooling systems. The procedure is demonstrated of the calculation of cooling towers, and correction curves and the effect assessed of the operating mode at constant air number or constant outlet air volume flow on their course in ventilator cooling towers. In cooling towers with the natural air draft the flow unevenness is assessed of water and air relative to its effect on the resulting cooling efficiency of the towers. The calculation is demonstrated of thermal and resistance response curves and cooling curves of hydraulically unevenly loaded towers owing to the water flow rate parameter graded radially by 20% along the cross-section of the packing. Flow rate unevenness of air due to wind impact on the outlet air flow from the tower significantly affects the temperatures of cooled water in natural air draft cooling towers of a design with lower demands on aerodynamics, as early as at wind velocity of 2 m.s -1 as was demonstrated on a concrete example. (author). 11 figs., 10 refs

  15. Hypervelocity impact cratering calculations

    Science.gov (United States)

    Maxwell, D. E.; Moises, H.

    1971-01-01

    A summary is presented of prediction calculations on the mechanisms involved in hypervelocity impact cratering and response of earth media. Considered are: (1) a one-gram lithium-magnesium alloys impacting basalt normally at 6.4 km/sec, and (2) a large terrestrial impact corresponding to that of Sierra Madera.

  16. Languages for structural calculations

    International Nuclear Information System (INIS)

    Thomas, J.B.; Chambon, M.R.

    1988-01-01

    The differences between human and computing languages are recalled. It is argued that they are to some extent structured in antagonistic ways. Languages in structural calculation, in the past, present, and future, are considered. The contribution of artificial intelligence is stressed [fr

  17. Monte Carlo alpha calculation

    Energy Technology Data Exchange (ETDEWEB)

    Brockway, D.; Soran, P.; Whalen, P.

    1985-01-01

    A Monte Carlo algorithm to efficiently calculate static alpha eigenvalues, N = ne/sup ..cap alpha..t/, for supercritical systems has been developed and tested. A direct Monte Carlo approach to calculating a static alpha is to simply follow the buildup in time of neutrons in a supercritical system and evaluate the logarithmic derivative of the neutron population with respect to time. This procedure is expensive, and the solution is very noisy and almost useless for a system near critical. The modified approach is to convert the time-dependent problem to a static ..cap alpha../sup -/eigenvalue problem and regress ..cap alpha.. on solutions of a/sup -/ k/sup -/eigenvalue problem. In practice, this procedure is much more efficient than the direct calculation, and produces much more accurate results. Because the Monte Carlo codes are intrinsically three-dimensional and use elaborate continuous-energy cross sections, this technique is now used as a standard for evaluating other calculational techniques in odd geometries or with group cross sections.

  18. Reactor dynamics calculations

    International Nuclear Information System (INIS)

    Devooght, J.; Lefvert, T.; Stankiewiez, J.

    1981-01-01

    This chapter deals with the work done in reactor dynamics within the Coordinated Research Program on Transport Theory and Advanced Reactor Calculations by three groups in Belgium, Poland, Sweden and Italy. Discretization methods in diffusion theory, collision probability methods in time-dependent neutron transport and singular perturbation method are represented in this paper

  19. Equilibrium fission model calculations

    International Nuclear Information System (INIS)

    Beckerman, M.; Blann, M.

    1976-01-01

    In order to aid in understanding the systematics of heavy ion fission and fission-like reactions in terms of the target-projectile system, bombarding energy and angular momentum, fission widths are calculated using an angular momentum dependent extension of the Bohr-Wheeler theory and particle emission widths using angular momentum coupling

  20. Configuration Entropy Calculations for Complex Compounds Technetium

    International Nuclear Information System (INIS)

    Muhayatun; Susanto Imam Rahayu; Surdia, N.M.; Abdul Mutalib

    2002-01-01

    Recently, the study of technetium complexes is rapidly increasing, due to the benefit of 99m Tc complexes (one of Tc nuclear isomers), which are widely used for diagnostics. Study of the structure-stability relationship of Tc complexes based on solid angle has been done by Kung using a Solid Angle Factor Sum (SAS). The SAS is hypothesized to be related to stability. SAS has been used by several researchers either for synthesis or designing the reaction route of the Tc complex formation and predicting the geometry of complex structures. Although the advantages of the SAS were very gratifying, but the model does not have the theoretical basis which is able to explain the correlation of steric parameters to physicochemical properties of complexes especially to those connected to a complex's stability. To improve the SAS model, in this research the model was modified by providing a theoretical basis for SAS. The results obtained from the correlation of the SAS value to the thermodynamic stability parameters of simple complexes show the values to have a similar trend as the standard entropy (S 0 ). The entropy approximation model was created by involving some factors which are not used in Kung's model. Entropy optimization to the bond length (ML) has also been done to several complexes. The calculations of SAS value using the calculated R for more than 100 Tc complexes provide a normalized mean value of 0.8545 ± 0.0851 and have similar curve profiles as those of Kung's model. The entropy value can be obtained by multiplying the natural logarithm of the a priori degeneracy of a certain distribution (Ω) and the Boltzmann constant. The results of Ω and In Ω of the Tc complexes have a narrow range. The results of this research are able to provide a basic concept for the SAS to explain the structure-stability relationship and to improve Kung's model. (author)

  1. Kinetic stability of field-reversed configurations

    International Nuclear Information System (INIS)

    Staudenmeier, J.L.; Hsiao, M.-Y.

    1991-01-01

    The internal tilt mode is considered to be the biggest threat to Field-Reversed Configuration (FRC) global stability. The tilt stability of the FRC is studied using the MHD, Hall MHD, and the Vlasov-fluid (Vlasov ions, cold massless fluid electrons) models. Nonlinear Hall MHD calculations showed that the FRC was stable to the tilt mode when the s value of the FRC was below a critical value that was dependent on plasma length. The critical s value is larger for longer plasma equilibria. The stability of FRC's with toroidal field was studied with a linear initial value MHD code. The calculations showed an axial perturbation wavelength of the most unstable eigenfunction that was consistent with internal probe measurements made on translated FRC's. Linear Vlasov-fluid eigenvalue calculations showed that kinetic ion effects can change both the growth rate and the structure of the eigenfunctions when compared to the corresponding MHD modes. Calculations on short FRC equilibria indicate that MHD is not the appropriate small gyroradius limit of the Vlasov-fluid model because the axial transit time of a thermal ion is approximately equal to an MHD growth time for the tilt mode. Calculations were done using a small number of unstable MHD eigenfunctions as basis functions in order to reduce the dimensionality of the stability problem. The results indicated that this basis set can produce inaccurate growth rates at large value for s for some equilibria

  2. Stability of Dolos Slopes

    DEFF Research Database (Denmark)

    Brorsen, Michael; Burcharth, Hans F.; Larsen, Torben

    The stability of dolos armour blocks against wave attack has been investigated in wave model studies.......The stability of dolos armour blocks against wave attack has been investigated in wave model studies....

  3. Stability of parallel flows

    CERN Document Server

    Betchov, R

    2012-01-01

    Stability of Parallel Flows provides information pertinent to hydrodynamical stability. This book explores the stability problems that occur in various fields, including electronics, mechanics, oceanography, administration, economics, as well as naval and aeronautical engineering. Organized into two parts encompassing 10 chapters, this book starts with an overview of the general equations of a two-dimensional incompressible flow. This text then explores the stability of a laminar boundary layer and presents the equation of the inviscid approximation. Other chapters present the general equation

  4. Leave-two-out stability of ontology learning algorithm

    International Nuclear Information System (INIS)

    Wu, Jianzhang; Yu, Xiao; Zhu, Linli; Gao, Wei

    2016-01-01

    Ontology is a semantic analysis and calculation model, which has been applied to many subjects. Ontology similarity calculation and ontology mapping are employed as machine learning approaches. The purpose of this paper is to study the leave-two-out stability of ontology learning algorithm. Several leave-two-out stabilities are defined in ontology learning setting and the relationship among these stabilities are presented. Furthermore, the results manifested reveal that leave-two-out stability is a sufficient and necessary condition for ontology learning algorithm.

  5. Stability of flow from a nuclear cavity. Final report

    International Nuclear Information System (INIS)

    Morrison, F.A. Jr.

    1977-07-01

    The stability of flow from a nuclear cavity was examined. The flow of interest consists of air and steam at high pressure and temperature moving through a porous medium. The steam condenses at a moving front. The stability of the flow was analyzed using the normal mode method and a program was written to perform the necessary calculations. Results of the computer calculations show that the flow of interest is stable and any instabilities that occur will decay slowly. Stability was influenced by gravity, fluid mobilities, and condensation. It was found that the stabilizing effect of conductivity is only important at negligibly small wavelengths

  6. Sea surface stability parameters

    International Nuclear Information System (INIS)

    Weber, A.H.; Suich, J.E.

    1978-01-01

    A number of studies dealing with climatology of the Northwest Atlantic Ocean have been published in the last ten years. These published studies have dealt with directly measured meteorological parameters, e.g., wind speed, temperature, etc. This information has been useful because of the increased focus on the near coastal zone where man's activities are increasing in magnitude and scope, e.g., offshore power plants, petroleum production, and the subsequent environmental impacts of these activities. Atmospheric transport of passive or nonpassive material is significantly influenced by the turbulence structure of the atmosphere in the region of the atmosphere-ocean interface. This research entails identification of the suitability of standard atmospheric stability parameters which can be used to determine turbulence structure; the calculation of these parameters for the near-shore and continental shelf regions of the U.S. east coast from Cape Hatteras to Miami, Florida; and the preparation of a climatology of these parameters. In addition, a climatology for average surface stress for the same geographical region is being prepared

  7. ICRF stabilization of sawteeth on TFTR

    International Nuclear Information System (INIS)

    Phillips, C.K.; Hosea, J.; Stevens, J.; Wilson, J.R.; Bell, M.; Bitter, M.; Cheng, C.Z.; Darrow, D.; Fredrickson, E.; Hammett, G.W.; Hill, K.; Hsuan, H.; Jassby, D.; McCune, D.; McGuire, K.; Owens, D.K.; Park, H.; Ramsey, A.; Schilling, G.; Schivell, J.; Stratton, B.; Synakowski, E.; Taylor, G.; Towner, H.; White, R.; Zweben, S.; Phillips, M.W.; Hughes, M.; Bush, C.; Goldfinger, R.; Hoffman, D.; Houlberg, W.; Nagayama, Y.; Smithe, D.N.

    1992-01-01

    Results obtained from experiments utilizing high power ICRF (ion cyclotron range of frequency) heating to stabilize sawtooth oscillations on TFTR are reviewed. The key observations include existence of a minimum ICRF power required to achieve stabilization, a dependence of the stabilization threshold on the relative size of the ICRF power deposition profile to the q=1 volume, and a peaking of the equilibrium pressure and current profiles during sawtooth-free phases of the discharges. In addition, preliminary measurements of the poloidal magnetic field profile indicate that q on axis decreases to a value of 0.55±0.15 after a sawtooth-stabilized period of ∼0.5 sec has transpired. The results are discussed in the context of theory, which suggests that the fast ions produced by the ICRF heating suppress sawteeth by stabilizing the m=1 MHD instabilities believed to be the trigger for the sawtooth oscillations. Though qualitative agreement is found between the observations and the theory, further refinement of the theory coupled with more accurate measurements of experimental profiles will be required in order to complete quantitative comparisons

  8. Stability Study of the RERTR Fuel Microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Jian Gan; Dennis Keiser; Brandon Miller; Daniel Wachs

    2014-04-01

    The irradiation stability of the interaction phases at the interface of fuel and Al alloy matrix as well as the stability of the fission gas bubble superlattice is believed to be very important to the U-Mo fuel performance. In this paper the recent result from TEM characterization of Kr ion irradiated U-10Mo-5Zr alloy will be discussed. The focus will be on the phase stability of Mo2-Zr, a dominated second phase developed at the interface of U-10Mo and the Zr barrier in a monolithic fuel plate from fuel fabrication. The Kr ion irradiations were conducted at a temperature of 200 degrees C to an ion fluence of 2.0E+16 ions/cm2. To investigate the thermal stability of the fission gas bubble superlattice, a key microstructural feature in both irradiated dispersion U-7Mo fuel and monolithic U-10Mo fuel, a FIB-TEM sample of the irradiated U-10Mo fuel (3.53E+21 fission/cm3) was used for a TEM in-situ heating experiment. The preliminary result showed extraordinary thermal stability of the fission gas bubble superlattice. The implication of the TEM observation from these two experiments on the fuel microstructural evolution under irradiation will be discussed.

  9. The BWR Stability Issue

    International Nuclear Information System (INIS)

    D'Auria, F.

    2008-01-01

    The purpose of this paper is to supply general information about Boiling Water Reactor (BWR) stability. The main concerned topics are: phenomenological aspects, experimental database, modelling features and capabilities, numerical models, three-dimensional modelling, BWR system performance during stability, stability monitoring and licensing aspects.

  10. Course on hybrid calculation

    International Nuclear Information System (INIS)

    Weill, J.; Tellier; Bonnemay; Craigne; Chareton; Di Falco

    1969-02-01

    After a definition of hybrid calculation (combination of analogue and digital calculation) with a distinction between series and parallel hybrid computing, and a description of a hybrid computer structure and of task sharing between computers, this course proposes a description of hybrid hardware used in Saclay and Cadarache computing centres, and of operations performed by these systems. The next part addresses issues related to programming languages and software. The fourth part describes how a problem is organised for its processing on these computers. Methods of hybrid analysis are then addressed: resolution of optimisation problems, of partial differential equations, and of integral equations by means of different methods (gradient, maximum principle, characteristics, functional approximation, time slicing, Monte Carlo, Neumann iteration, Fischer iteration)

  11. Calculation of projected ranges

    International Nuclear Information System (INIS)

    Biersack, J.P.

    1980-09-01

    The concept of multiple scattering is reconsidered for obtaining the directional spreading of ion motion as a function of energy loss. From this the mean projection of each pathlength element of the ion trajectory is derived which - upon summation or integration - leads to the desired mean projected range. In special cases, the calculation can be carried out analytically, otherwise a simple general algorithm is derived which is suitable even for the smallest programmable calculators. Necessary input for the present treatment consists only of generally accessable stopping power and straggling formulas. The procedure does not rely on scattering cross sections, e.g. power potential or f(t 1 sup(/) 2 ) approximations. The present approach lends itself easily to include electronic straggling or to treat composed target materials, or even to account for the so-called time integral. (orig.)

  12. Spallation reactions: calculations

    International Nuclear Information System (INIS)

    Bertini, H.W.

    1975-01-01

    Current methods for calculating spallation reactions over various energy ranges are described and evaluated. Recent semiempirical fits to existing data will probably yield the most accurate predictions for these reactions in general. However, if the products in question have binding energies appreciably different from their isotropic neighbors and if the cross section is approximately 30 mb or larger, then the intranuclear-cascade-evaporation approach is probably better suited. (6 tables, 12 figures, 34 references) (U.S.)

  13. Performance assessment calculational exercises

    International Nuclear Information System (INIS)

    Barnard, R.W.; Dockery, H.A.

    1990-01-01

    The Performance Assessment Calculational Exercises (PACE) are an ongoing effort coordinated by Yucca Mountain Project Office. The objectives of fiscal year 1990 work, termed PACE-90, as outlined in the Department of Energy Performance Assessment (PA) Implementation Plan were to develop PA capabilities among Yucca Mountain Project (YMP) participants by calculating performance of a Yucca Mountain (YM) repository under ''expected'' and also ''disturbed'' conditions, to identify critical elements and processes necessary to assess the performance of YM, and to perform sensitivity studies on key parameters. It was expected that the PACE problems would aid in development of conceptual models and eventual evaluation of site data. The PACE-90 participants calculated transport of a selected set of radionuclides through a portion of Yucca Mountain for a period of 100,000 years. Results include analyses of fluid-flow profiles, development of a source term for radionuclide release, and simulations of contaminant transport in the fluid-flow field. Later work included development of a problem definition for perturbations to the originally modeled conditions and for some parametric sensitivity studies. 3 refs

  14. Pickering safeguards: a preliminary analysis

    International Nuclear Information System (INIS)

    Todd, J.L.; Hodgkinson, J.G.

    1977-05-01

    A summary is presented of thoughts relative to a systems approach for implementing international safeguards. Included is a preliminary analysis of the Pickering Generating Station followed by a suggested safeguards system for the facility

  15. Cell emulation and preliminary results.

    Science.gov (United States)

    2016-07-01

    This report details preliminary results of the testing plan implemented by the Hawaii Natural Energy Institute to evaluate Electric Vehicle (EV) battery durability and reliability under electric utility grid operations. Commercial EV battery cells ar...

  16. Preliminary design of a tandem mirror reactor

    International Nuclear Information System (INIS)

    Strohmayer, J.N.

    1984-04-01

    The purpose of this thesis is to examine the TARA mirror experiment as a possible tandem mirror reactor configuration. This is a preliminary study to size the coil structure based on using the smallest end cell axial length that physics and engineering allow, zeroing the central cell parallel currents and having interchange stability. The input powers are estimated for the final reactor design so a Q value may be estimated. The Q value is defined as the fusion power divided by the total injected power absorbed by the plasma. A computer study was performed on the effect of the transition size, the transition vertical spacing and transition current. These parameters affect the central cell parallel currents, the recircularization of the flux tube and the ratio of central cell beta to anchor beta needed for marginal stability. Two designs were identified. The first uses 100 keV and 13 keV neutral beams to pump the ions that trap in the thermal barrier. The Q value of this reactor is 11.3. The second reactor uses a pump beam at 40 keV. This energy is chosen because there is a resonance for the charge exchange cross section between D 0 and He 2+ at this energy, thus the alpha ash will be pumped along with the deuterium and tritium. The Q value of this reactor is 11.6

  17. Feedback stabilization initiative

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    Much progress has been made in attaining high confinement regimes in magnetic confinement devices. These operating modes tend to be transient, however, due to the onset of MHD instabilities, and their stabilization is critical for improved performance at steady state. This report describes the Feedback Stabilization Initiative (FSI), a broad-based, multi-institutional effort to develop and implement methods for raising the achievable plasma betas through active MHD feedback stabilization. A key element in this proposed effort is the Feedback Stabilization Experiment (FSX), a medium-sized, national facility that would be specifically dedicated to demonstrating beta improvement in reactor relevant plasmas by using a variety of MHD feedback stabilization schemes.

  18. Feedback stabilization initiative

    International Nuclear Information System (INIS)

    1997-06-01

    Much progress has been made in attaining high confinement regimes in magnetic confinement devices. These operating modes tend to be transient, however, due to the onset of MHD instabilities, and their stabilization is critical for improved performance at steady state. This report describes the Feedback Stabilization Initiative (FSI), a broad-based, multi-institutional effort to develop and implement methods for raising the achievable plasma betas through active MHD feedback stabilization. A key element in this proposed effort is the Feedback Stabilization Experiment (FSX), a medium-sized, national facility that would be specifically dedicated to demonstrating beta improvement in reactor relevant plasmas by using a variety of MHD feedback stabilization schemes

  19. RCRA facility stabilization initiative

    International Nuclear Information System (INIS)

    1995-02-01

    The RCRA Facility Stabilization Initiative was developed as a means of implementing the Corrective Action Program's management goals recommended by the RIS for stabilizing actual or imminent releases from solid waste management units that threaten human health and the environment. The overall goal of stabilization is to, as situations warrant, control or abate threats to human health and/or the environment from releases at RCRA facilities, and/or to prevent or minimize the further spread of contamination while long-term remedies are pursued. The Stabilization initiative is a management philosophy and should not be confused with stabilization technologies

  20. Simplified shielding calculation system for high-intensity proton accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Masumura, Tomomi; Nakashima, Hiroshi; Nakane, Yoshihiro; Sasamoto, Nobuo [Center for Neutron Science, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    2000-06-01

    A simplified shielding calculation system is developed for applying conceptual shielding design of facilities in the joint project for high-intensity proton accelerators. The system is composed of neutron transmission calculation part for bulk shielding using simplified formulas: Moyer model and Tesch's formula, and neutron skyshine calculation part using an empirical formula: Stapleton's formula. The system is made with the Microsoft Excel software for user's convenience. This report provides a manual for the system as well as calculation conditions used in the calculation such as Moyer model's parameters. In this report preliminary results based on data at December 8, 1999, are also shown as an example. (author)

  1. A Preliminary Fire PSA on PGSFR

    International Nuclear Information System (INIS)

    Kim, Kilyoo; Han, Sanghoon; Lee, KwiLim

    2017-01-01

    A Prototype Generation IV Sodium Fast Reactor (PGSFR) is under design with defense in depth concept with active, passive, and inherent safety features to acquire a design approval for PGSFR from Korean regulatory authority by around 2017. A preliminary fire PSA on PGSFR is done in 2016 and a final fire PSA of PGSFR will be done in 2017. The characteristics of the preliminary fire PSA on PGSFR are described in this paper. Since PGSFR is very safe reactor, it is not bad approach to use a conservative assumption in the preliminary PSA. In addition, several drawings including cable routing are not yet issued, a conservative calculation for CDF is performed. As shown in Table 2, the CDF caused by the fire in the control room takes 89% portion of total CDF. Thus, a detailed fire modeling for control room is necessary for the final fire PSA on PGSFR. Also, the increased ignition frequency due to sodium leak would be derived by considering the sodium piping complexity in the final fire PSA on PGSFR. The 4th column of Table 2 is derived the 3rd column by multiplying the factor (592/1177). The 5th column is the ignition frequency caused by the sodium leak. The 6th column is derived by summing the 4th column and the 5th column. The 7th column is the CDF portion of each fire area. The control room (fire area F-A404A) is the most important area since the control room fire takes 89% portion of total CDF.

  2. Calculations for very low energy scattering of positrons by molecular hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J.N. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)], E-mail: james.cooper@maths.nottingham.ac.uk; Armour, E.A.G. [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2008-02-15

    We give a progress report on ongoing calculations of phase shifts for very low energy elastic scattering of positrons by molecular hydrogen, using the generalised Kohn variational method. Further, provisional calculations of Z{sub eff} for molecular hydrogen at low energies are presented and discussed. The preliminary nature of the work is emphasised throughout.

  3. Comparison of SOLA-FLX calculations with experiments at systems, science and software

    International Nuclear Information System (INIS)

    Dienes, J.K.; Hirt, C.W.; Stein, L.R.

    1977-03-01

    Preliminary results of a comparison between hydroelastic calculations at the Los Alamos Scientific Laboratory and experiments at Systems, Science and Software are described. The axisymmetric geometry is an idealization of a pressurized water reactor at a scale of 1/25. Reasons for some of the discrepancies are described, and suggestions for improving both experiments and calculations are discussed

  4. Accurate quantum chemical calculations

    Science.gov (United States)

    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.

  5. Association of Stability Parameters and Yield Stability of Sesame ...

    African Journals Online (AJOL)

    Association of Stability Parameters and Yield Stability of Sesame ( Sesamum ... Information on phenotypic stability is useful for the selection of crop varieties as well as for ... as an alternative to parametric stability measurements is important.

  6. Navier-Stokes Predictions of Dynamic Stability Derivatives: Evaluation of Steady-State Methods

    National Research Council Canada - National Science Library

    DeSpirito, James; Silton, Sidra I; Weinacht, Paul

    2008-01-01

    The prediction of the dynamic stability derivatives-roll-damping, Magnus, and pitch-damping moments-were evaluated for three spin-stabilized projectiles using steady-state computational fluid dynamic (CFD) calculations...

  7. Zero Temperature Hope Calculations

    International Nuclear Information System (INIS)

    Rozsnyai, B. F.

    2002-01-01

    The primary purpose of the HOPE code is to calculate opacities over a wide temperature and density range. It can also produce equation of state (EOS) data. Since the experimental data at the high temperature region are scarce, comparisons of predictions with the ample zero temperature data provide a valuable physics check of the code. In this report we show a selected few examples across the periodic table. Below we give a brief general information about the physics of the HOPE code. The HOPE code is an ''average atom'' (AA) Dirac-Slater self-consistent code. The AA label in the case of finite temperature means that the one-electron levels are populated according to the Fermi statistics, at zero temperature it means that the ''aufbau'' principle works, i.e. no a priory electronic configuration is set, although it can be done. As such, it is a one-particle model (any Hartree-Fock model is a one particle model). The code is an ''ion-sphere'' model, meaning that the atom under investigation is neutral within the ion-sphere radius. Furthermore, the boundary conditions for the bound states are also set at the ion-sphere radius, which distinguishes the code from the INFERNO, OPAL and STA codes. Once the self-consistent AA state is obtained, the code proceeds to generate many-electron configurations and proceeds to calculate photoabsorption in the ''detailed configuration accounting'' (DCA) scheme. However, this last feature is meaningless at zero temperature. There is one important feature in the HOPE code which should be noted; any self-consistent model is self-consistent in the space of the occupied orbitals. The unoccupied orbitals, where electrons are lifted via photoexcitation, are unphysical. The rigorous way to deal with that problem is to carry out complete self-consistent calculations both in the initial and final states connecting photoexcitations, an enormous computational task. The Amaldi correction is an attempt to address this problem by distorting the

  8. Calculation of the inventory

    International Nuclear Information System (INIS)

    Heilbron Filho, P.F.L.; Oliveira Brandao, R. de.

    1988-04-01

    The theory of Point Kernel applied to a source uniformelly distributed in a cylindrical geometry was utilized to estimated the Cs-137 content of each package of radioactive waste collected. The Taylor equation was employed to calculate the build-up factor and the Green function G was adjusted by means of a least square method. The theory also takes into account factors such as aditional shielding, heterogeneity and humidity of the medium as well as associated uncertanties of the parameters envolved. (author) [pt

  9. Calculations in furnace technology

    CERN Document Server

    Davies, Clive; Hopkins, DW; Owen, WS

    2013-01-01

    Calculations in Furnace Technology presents the theoretical and practical aspects of furnace technology. This book provides information pertinent to the development, application, and efficiency of furnace technology. Organized into eight chapters, this book begins with an overview of the exothermic reactions that occur when carbon, hydrogen, and sulfur are burned to release the energy available in the fuel. This text then evaluates the efficiencies to measure the quantity of fuel used, of flue gases leaving the plant, of air entering, and the heat lost to the surroundings. Other chapters consi

  10. Deep penetration calculations

    International Nuclear Information System (INIS)

    Thompson, W.L.; Deutsch, O.L.; Booth, T.E.

    1980-04-01

    Several Monte Carlo techniques are compared in the transport of neutrons of different source energies through two different deep-penetration problems each with two parts. The first problem involves transmission through a 200-cm concrete slab. The second problem is a 90 0 bent pipe jacketed by concrete. In one case the pipe is void, and in the other it is filled with liquid sodium. Calculations are made with two different Los Alamos Monte Carlo codes: the continuous-energy code MCNP and the multigroup code MCMG

  11. Technical note: Rapid calculation of genomic evaluations for new animals.

    Science.gov (United States)

    Wiggans, G R; VanRaden, P M; Cooper, T A

    2015-03-01

    A method was developed to calculate preliminary genomic evaluations daily or weekly before the release of official monthly evaluations by processing only newly genotyped animals using estimates of single nucleotide polymorphism effects from the previous official evaluation. To minimize computing time, reliabilities and genomic inbreeding are not calculated, and fixed weights are used to combine genomic and traditional information. Correlations of preliminary and September official monthly evaluations for animals with genotypes that became usable after the extraction of genotypes for August 2014 evaluations were >0.99 for most Holstein traits. Correlations were lower for breeds with smaller population size. Earlier access to genomic evaluations benefits producers by enabling earlier culling decisions and genotyping laboratories by making workloads more uniform across the month. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Sawtooth stabilization by energetic trapped particles

    International Nuclear Information System (INIS)

    White, R.B.; Rutherford, P.H.; Colestock, P.; Bussac, M.N.

    1988-03-01

    Recent experiments involving high power radio-frequency heating of a tokamak plasma show strong suppression of the sawtooth oscillation. A high energy trapped particle population is shown to have a strong stabilizing effect on the internal resistive kink mode. Numerical calculations are in reasonable agreement with experiment. 13 refs., 2 figs

  13. MOLECULAR STRUCTURE AND STABILITY E. Vessally* Payame ...

    African Journals Online (AJOL)

    Preferred Customer

    planar conformers are also found for NO, CO, SiO, GeO, O, C, Si, Ge. Isodesmic reactions to determine the stabilities of XO and X are considered. Nuclear independent chemical shifts, NICS, are calculated for the investigation of the homo-aromatic character of XO and X. The optimised geometries show the bonding in the.

  14. MHD stability of vertically asymmetric tokamak equilibria

    International Nuclear Information System (INIS)

    Dalhed, H.E.; Grimm, R.C.; Johnson, J.L.

    1981-03-01

    The ideal MHD stability properties of a special class of vertically asymmetric tokamak equilibria are examined. The calculations confirm that no major new physical effects are introduced and the modifications can be understood by conventional arguments. The results indicate that significant departures from up-down symmetry can be tolerated before the reduction in β becomes important for reactor operation

  15. Preliminary Hazards Analysis Plasma Hearth Process

    International Nuclear Information System (INIS)

    Aycock, M.; Coordes, D.; Russell, J.; TenBrook, W.; Yimbo, P.

    1993-11-01

    This Preliminary Hazards Analysis (PHA) for the Plasma Hearth Process (PHP) follows the requirements of United States Department of Energy (DOE) Order 5480.23 (DOE, 1992a), DOE Order 5480.21 (DOE, 1991d), DOE Order 5480.22 (DOE, 1992c), DOE Order 5481.1B (DOE, 1986), and the guidance provided in DOE Standards DOE-STD-1027-92 (DOE, 1992b). Consideration is given to ft proposed regulations published as 10 CFR 830 (DOE, 1993) and DOE Safety Guide SG 830.110 (DOE, 1992b). The purpose of performing a PRA is to establish an initial hazard categorization for a DOE nuclear facility and to identify those processes and structures which may have an impact on or be important to safety. The PHA is typically performed during and provides input to project conceptual design. The PRA then is followed by a Preliminary Safety Analysis Report (PSAR) performed during Title I and II design. This PSAR then leads to performance of the Final Safety Analysis Report performed during construction, testing, and acceptance and completed before routine operation. Radiological assessments indicate that a PHP facility, depending on the radioactive material inventory, may be an exempt, Category 3, or Category 2 facility. The calculated impacts would result in no significant impact to offsite personnel or the environment. Hazardous material assessments indicate that a PHP facility will be a Low Hazard facility having no significant impacts either onsite or offsite to personnel and the environment

  16. Weldon Spring dose calculations

    International Nuclear Information System (INIS)

    Dickson, H.W.; Hill, G.S.; Perdue, P.T.

    1978-09-01

    In response to a request by the Oak Ridge Operations (ORO) Office of the Department of Energy (DOE) for assistance to the Department of the Army (DA) on the decommissioning of the Weldon Spring Chemical Plant, the Health and Safety Research Division of the Oak Ridge National Laboratory (ORNL) performed limited dose assessment calculations for that site. Based upon radiological measurements from a number of soil samples analyzed by ORNL and from previously acquired radiological data for the Weldon Spring site, source terms were derived to calculate radiation doses for three specific site scenarios. These three hypothetical scenarios are: a wildlife refuge for hunting, fishing, and general outdoor recreation; a school with 40 hr per week occupancy by students and a custodian; and a truck farm producing fruits, vegetables, meat, and dairy products which may be consumed on site. Radiation doses are reported for each of these scenarios both for measured uranium daughter equilibrium ratios and for assumed secular equilibrium. Doses are lower for the nonequilibrium case

  17. Configuration space Faddeev calculations

    International Nuclear Information System (INIS)

    Payne, G.L.; Klink, W.H.; Polyzou, W.N.

    1989-01-01

    The detailed study of few-body systems provides one of the most effective means for studying nuclear physics at subnucleon distance scales. For few-body systems the model equations can be solved numerically with errors less than the experimental uncertainties. We have used such systems to investigate the size of relativistic effects, the role of meson-exchange currents, and the importance of quark degrees of freedom in the nucleus. Complete calculations for momentum-dependent potentials have been performed, and the properties of the three-body bound state for these potentials have been studied. Few-body calculations of the electromagnetic form factors of the deuteron and pion have been carried out using a front-form formulation of relativistic quantum mechanics. The decomposition of the operators transforming convariantly under the Poincare group into kinematical and dynamical parts has been studies. New ways for constructing interactions between particles, as well as interactions which lead to the production of particles, have been constructed in the context of a relativistic quantum mechanics. To compute scattering amplitudes in a nonperturbative way, classes of operators have been generated out of which the phase operator may be constructed. Finally, we have worked out procedures for computing Clebsch-Gordan and Racah coefficients on a computer, as well as giving procedures for dealing with the multiplicity problem

  18. Buoyant plume calculations

    International Nuclear Information System (INIS)

    Penner, J.E.; Haselman, L.C.; Edwards, L.L.

    1985-01-01

    Smoke from raging fires produced in the aftermath of a major nuclear exchange has been predicted to cause large decreases in surface temperatures. However, the extent of the decrease and even the sign of the temperature change, depend on how the smoke is distributed with altitude. We present a model capable of evaluating the initial distribution of lofted smoke above a massive fire. Calculations are shown for a two-dimensional slab version of the model and a full three-dimensional version. The model has been evaluated by simulating smoke heights for the Hamburg firestorm of 1943 and a smaller scale oil fire which occurred in Long Beach in 1958. Our plume heights for these fires are compared to those predicted by the classical Morton-Taylor-Turner theory for weakly buoyant plumes. We consider the effect of the added buoyancy caused by condensation of water-laden ground level air being carried to high altitude with the convection column as well as the effects of background wind on the calculated smoke plume heights for several fire intensities. We find that the rise height of the plume depends on the assumed background atmospheric conditions as well as the fire intensity. Little smoke is injected into the stratosphere unless the fire is unusually intense, or atmospheric conditions are more unstable than we have assumed. For intense fires significant amounts of water vapor are condensed raising the possibility of early scavenging of smoke particles by precipitation. 26 references, 11 figures

  19. Nuclear Data Processing for Reactor Physics Calculation

    International Nuclear Information System (INIS)

    Suwoto; Zuhair; Pandiangan, Tumpal

    2003-01-01

    Nuclear data processing for reactor physics calculation has been done. Raw nuclear data cross-sections on file ENDF should be prepared and processed before it used in neutronic calculation. The processing code system such as NJOY-PC code has been used from linearization of nuclear cross-sections data and background contribution of resonance parameter (MF2) using RECONR module (0K) with energy range from 10 -5 to 10 7 eV. Afterward, the neutron cross-sections data should be processed and broadened to desire temperature (i.e. 293K) by using BROADR module. The Grouper and Therma modules will be applied for multi-groups calculation which suitable for WIMS/D4 (69 groups) and thermalization of nuclear constants. The final stage of processing nuclear cross-sections is updating WIMS/D4 library. The WIMSR module in NJOY-PC and WILLIE code will be applied in this stage. The evaluated nuclear data file, especially for 1 H 1 isotope, was taken from JENDL-3.2 and ENDF/B-VI for preliminary study. The results of nuclear data processing 1 H 1 shows that the old-WIMS (WIMS-lama) library have much discrepancies comparing with JENDL-3.2 or ENDF/B-VI files, especially in energy around 5 keV

  20. Vestibule and Cask Preparation Mechanical Handling Calculation

    International Nuclear Information System (INIS)

    Ambre, N.

    2004-01-01

    The scope of this document is to develop the size, operational envelopes, and major requirements of the equipment to be used in the vestibule, cask preparation area, and the crane maintenance area of the Fuel Handling Facility. This calculation is intended to support the License Application (LA) submittal of December 2004, in accordance with the directive given by DOE correspondence received on the 27th of January 2004 entitled: ''Authorization for Bechtel SAIC Company L.L.C. to Include a Bare Fuel Handling Facility and Increased Aging Capacity in the License Application, Contract Number DE-AC--28-01R W12101'' (Ref. 167124). This correspondence was appended by further correspondence received on the 19th of February 2004 entitled: ''Technical Direction to Bechtel SAIC Company L.L. C. for Surface Facility Improvements, Contract Number DE-AC--28-01R W12101; TDL No. 04-024'' (Ref. 16875 1). These documents give the authorization for a Fuel Handling Facility to be included in the baseline. The limitations of this preliminary calculation lie within the assumptions of section 5 , as this calculation is part of an evolutionary design process

  1. Calculated NWIS signatures for enriched uranium metal

    International Nuclear Information System (INIS)

    Valentine, T.E.; Mihalczo, J.T.; Koehler, P.E.

    1995-01-01

    Nuclear Weapons Identification System (NWIS) signatures have been calculated using a Monte Carlo transport code for measurement configurations of a 252 Cf source, detectors, and a uranium metal casting. NWIS signatures consist of a wide variety of time-and frequency-analysis signatures such as the time distribution of neutrons after californium fission, the time distribution of counts in a detector after a previous count, the number of times n pulses occur in a time interval, and various frequency-analysis signatures, such as auto-power and cross-power spectral densities, coherences, and a ratio of spectral densities. This ratio is independent of detection efficiency. The analysis presented here, using the MCNP-DSP code, evaluates the applicability of this method for measurement of the 235 U content of 19-kg castings of depleted uranium and uranium with enrichments of 20, 40, 60, 80, 90, and 93.2 wt % 235 U. The dependence of the wide variety of NWIS signatures on 235 U content and possible configurations of a measurement system are presented. These preliminary calculations indicate short measurement times. Additional calculations are being performed to optimize the source-detector-moderator-casting configuration for the shortest measurement time. Although the NWIS method was developed for nuclear weapons identification, the development of a small processor now allows it to be also applied in a practical way to subcriticality measurements, nuclear fuel process monitoring and qualitative nondestructive assay of special nuclear material

  2. Improving the accuracy of dynamic mass calculation

    Directory of Open Access Journals (Sweden)

    Oleksandr F. Dashchenko

    2015-06-01

    Full Text Available With the acceleration of goods transporting, cargo accounting plays an important role in today's global and complex environment. Weight is the most reliable indicator of the materials control. Unlike many other variables that can be measured indirectly, the weight can be measured directly and accurately. Using strain-gauge transducers, weight value can be obtained within a few milliseconds; such values correspond to the momentary load, which acts on the sensor. Determination of the weight of moving transport is only possible by appropriate processing of the sensor signal. The aim of the research is to develop a methodology for weighing freight rolling stock, which increases the accuracy of the measurement of dynamic mass, in particular wagon that moves. Apart from time-series methods, preliminary filtration for improving the accuracy of calculation is used. The results of the simulation are presented.

  3. Theory analysis and simple calculation of travelling wave burnup scheme

    International Nuclear Information System (INIS)

    Zhang Jian; Yu Hong; Gang Zhi

    2012-01-01

    Travelling wave burnup scheme is a new burnup scheme that breeds fuel locally just before it burns. Based on the preliminary theory analysis, the physical imagine was found. Through the calculation of a R-z cylinder travelling wave reactor core with ERANOS code system, the basic physical characteristics of this new burnup scheme were concluded. The results show that travelling wave reactor is feasible in physics, and there are some good features in the reactor physics. (authors)

  4. Calculation of the beam injector steering system using Helmholtz coils

    International Nuclear Information System (INIS)

    Passaro, A.; Sircilli Neto, F.; Migliano, A.C.C.

    1991-03-01

    In this work, a preliminary evaluation of the beam injector steering system of the IEAv electron linac is presented. From the existing injector configuration and with the assumptions of monoenergetic beam (100 keV) and uniform magnetic field, two pairs of Helmholtz coils were calculated for the steering system. Excitations of 105 A.turn and 37 A.turn were determined for the first and second coils, respectively. (author)

  5. Preliminary Design of a Femtosecond Oscilloscope

    CERN Document Server

    Gazazyan, Edmond D; Kalantaryan, Davit K; Laziev, Edouard; Margaryan, Amour

    2005-01-01

    The calculations on motion of electrons in a finite length electromagnetic field of linearly and circularly polarized laser beams have shown that one can use the transversal deflection of electrons on a screen at a certain distance after the interaction region for the measurement of the length and longitudinal particle distribution of femtosecond bunches. In this work the construction and preliminary parameters of various parts of a device that may be called femtosecond oscilloscope are considered. The influence of various factors, such as the energy spread and size of the electron bunches, are taken into account. For CO2 laser intensity 1016 W/cm2 and field free drift length 1m the deflection is 5.3 and 0.06 cm, while the few centimeters long interaction length between 2 mirrors requires assembling accuracy 6 mm and 1.3 micron for 20 MeV to 50 keV, respectively.

  6. Preliminary Shielding Analysis for HCCB TBM Transport

    Science.gov (United States)

    Miao, Peng; Zhao, Fengchao; Cao, Qixiang; Zhang, Guoshu; Feng, Kaiming

    2015-09-01

    A preliminary shielding analysis on the transport of the Chinese helium cooled ceramic breeder test blanket module (HCCB TBM) from France back to China after being irradiated in ITER is presented in this contribution. Emphasis was placed on irradiation safety during transport. The dose rate calculated by MCNP/4C for the conceptual package design satisfies the relevant dose limits from IAEA that the dose rate 3 m away from the surface of the package containing low specific activity III materials should be less than 10 mSv/h. The change with location and the time evolution of dose rates after shutdown have also been studied. This will be helpful for devising the detailed transport plan of HCCB TBM back to China in the near future. supported by the Major State Basic Research Development Program of China (973 Program) (No. 2013GB108000)

  7. An extension of the fenske-hall LCAO method for approximate calculations of inner-shell binding energies of molecules

    Science.gov (United States)

    Zwanziger, Ch.; Reinhold, J.

    1980-02-01

    The approximate LCAO MO method of Fenske and Hall has been extended to an all-election method allowing the calculation of inner-shell binding energies of molecules and their chemical shifts. Preliminary results are given.

  8. Stability analysis by ERATO code

    International Nuclear Information System (INIS)

    Tsunematsu, Toshihide; Takeda, Tatsuoki; Matsuura, Toshihiko; Azumi, Masafumi; Kurita, Gen-ichi

    1979-12-01

    Problems in MHD stability calculations by ERATO code are described; which concern convergence property of results, equilibrium codes, and machine optimization of ERATO code. It is concluded that irregularity on a convergence curve is not due to a fault of the ERATO code itself but due to inappropriate choice of the equilibrium calculation meshes. Also described are a code to calculate an equilibrium as a quasi-inverse problem and a code to calculate an equilibrium as a result of a transport process. Optimization of the code with respect to I/O operations reduced both CPU time and I/O time considerably. With the FACOM230-75 APU/CPU multiprocessor system, the performance is about 6 times as high as with the FACOM230-75 CPU, showing the effectiveness of a vector processing computer for the kind of MHD computations. This report is a summary of the material presented at the ERATO workshop 1979(ORNL), supplemented with some details. (author)

  9. Secular stability of rotating stars

    International Nuclear Information System (INIS)

    Imamura, J.N.; Friedman, J.L.; Durisen, R.H.

    1984-01-01

    In this work, the authors calculate the secular stability limits of rotating polytropes to nonaxisymmetric perturbations of low m. Polytropic indices ranging from 1 to 3 and several angular momentum distributions are considered. Results are most conveniently presented in terms of the t-parameter, defined as the ratio of the rotational kinetic energy to the absolute value of the gravitational energy of the fluid. Previous work on polytropes considered only the m = 2 mode, which is unstable for values of the t-parameter greater than 0.14 +- 0.01 for the n values n = 1.5 and 3 and the angular momentum distributions tested (see Durisen and Imamura 1981). The GRR secular stability limit of the m - 2 mode for the Maclaurin spheroids (n = 0) was determined by Chandrasekhar (1970). GRR stability limits of higher m modes for the Maclaurin spheroids were located approximately by Comins (1979a,b) and more precisely by Friedman (1983). 16 references, 2 tables

  10. Stability of Hyperthermophilic Proteins

    DEFF Research Database (Denmark)

    Stiefler-Jensen, Daniel

    stability by randomly generate mutants and lengthy screening processes to identify the best new mutants. However, with the increase in available genomic sequences of thermophilic or hyperthermophilic organisms a world of enzymes with intrinsic high stability are now available. As these organisms are adapted...... to life at high temperatures so are their enzymes, as a result the high stability is accompanied by low activity at moderate temperatures. Thus, much effort had been put into decoding the mechanisms behind the high stability of the thermophilic enzymes. The hope is to enable scientist to design enzymes...... in the high stability of hyperthermophilic enzymes. The thesis starts with an introduction to the field of protein and enzyme stability with special focus on the thermophilic and hyperthermophilic enzymes and proteins. After the introduction three original research manuscripts present the experimental data...

  11. 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.)

  12. Calculating graduation rates.

    Science.gov (United States)

    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.

  13. Mice take calculated risks.

    Science.gov (United States)

    Kheifets, Aaron; Gallistel, C R

    2012-05-29

    Animals successfully navigate the world despite having only incomplete information about behaviorally important contingencies. It is an open question to what degree this behavior is driven by estimates of stochastic parameters (brain-constructed models of the experienced world) and to what degree it is directed by reinforcement-driven processes that optimize behavior in the limit without estimating stochastic parameters (model-free adaptation processes, such as associative learning). We find that mice adjust their behavior in response to a change in probability more quickly and abruptly than can be explained by differential reinforcement. Our results imply that mice represent probabilities and perform calculations over them to optimize their behavior, even when the optimization produces negligible material gain.

  14. Smile esthetics: calculated beauty?

    Science.gov (United States)

    Lecocq, Guillaume; Truong Tan Trung, Lisa

    2014-06-01

    Esthetic demand from patients continues to increase. Consequently, the treatments we offer are moving towards more discreet or invisible techniques using lingual brackets in order to achieve harmonious, balanced results in line with our treatment goals. As orthodontists, we act upon relationships between teeth and bone. And the equilibrium they create impacts the entire face via the smile. A balanced smile is essential to an esthetic outcome and is governed by rules, which guide both the practitioner and patient. A smile can be described in terms of mathematical ratios and proportions but beauty cannot be calculated. For the smile to sit harmoniously within the face, we need to take into account facial proportions and the possibility of their being modified by our orthopedic appliances or by surgery. Copyright © 2014 CEO. Published by Elsevier Masson SAS. All rights reserved.

  15. Engineering Judgment and Natural Circulation Calculations

    International Nuclear Information System (INIS)

    Ferreri, J.C.; Ferreri, J.C.

    2011-01-01

    The analysis performed to establish the validity of computer code results in the particular field of natural circulation flow stability calculations is presented in the light of usual engineering practice. The effects of discretization and closure correlations are discussed and some hints to avoid undesired mistakes in the evaluations performed are given. Additionally, the results are presented for an experiment relevant to the way in which a (small) number of skilled, nuclear safety analysts and researchers react when facing the solution of a natural circulation problem. These results may be also framed in the concept of Engineering Judgment and are potentially useful for Knowledge Management activities.

  16. Cobalamins uncovered by modern electronic structure calculations

    DEFF Research Database (Denmark)

    Kepp, Kasper Planeta; Ryde, Ulf

    2009-01-01

    electronic-structure calculations, in particular density functional methods, the understanding of the molecular mechanism of cobalamins has changed dramatically, going from a dominating view of trans-steric strain effects to a much more complex view involving an arsenal of catalytic strategies. Among...... these are cis-steric distortions, electrostatic stabilization of radical products, the realization that nucleotide units can serve as polar handles, and the careful design of the active sites, with polar residues in the radical enzymes and non-polar residues in the transferases. Together, these strategies...

  17. Preliminary design of RDE feedwater pump impeller

    International Nuclear Information System (INIS)

    Sri Sudadiyo

    2018-01-01

    Nowadays, pumps are being widely used in the thermal power generation including nuclear power plants. Reaktor Daya Experimental (RDE) is a proposed nuclear reactor concept for the type of nuclear power plant in Indonesia. This RDE has thermal power 10 MW th , and uses a feedwater pump within its steam cycle. The performance of feedwater pump depends on size and geometry of impeller model, such as the number of blades and the blade angle. The purpose of this study is to perform a preliminary design on an impeller of feedwater pump for RDE and to simulate its performance characteristics. The Fortran code is used as an aid in data calculation in order to rapidly compute the blade shape of feedwater pump impeller, particularly for a RDE case. The calculations analyses is solved by utilizing empirical correlations, which are related to size and geometry of a pump impeller model, while performance characteristics analysis is done based on velocity triangle diagram. The effect of leakage, pass through the impeller due to the required clearances between the feedwater pump impeller and the volute channel, is also considered. Comparison between the feedwater pump of HTR-10 and of RDE shows similarity in the trend line of curve shape. These characteristics curves will be very useful for the values prediction of performance of a RDE feedwater pump. Preliminary design of feedwater pump provides the size and geometry of impeller blade model with 5-blades, inlet angle 14.5 degrees, exit angle 25 degrees, inside diameter 81.3 mm, exit diameter 275.2 mm, thickness 4.7 mm, and height 14.1 mm. In addition, the optimal values of performance characteristics were obtained when flow capacity was 4.8 kg/s, fluid head was 29.1 m, shaft mechanical power was 2.64 kW, and efficiency was 52 % at rotational speed 1750 rpm. (author)

  18. Are Stabilization Programs Expansionary?

    OpenAIRE

    Federico Echenique; Alvaro Forteza

    1997-01-01

    The empirical evidence presented in this paper casts serious doubts on the by now widely accepted "stylized facts" of the exchange rate based stabilization programs (ERBS) as they are stated in Kiguel and Liviatan (1992) and in Végh (1992). Even though the ERBS programs were associated with output booms, no evidence of booms provoked by the stabilization programs is found. Rather, exogenous capital inflows to Latin America seem to have caused both the output booms and the stabilization progra...

  19. Surface rheology and interface stability.

    Energy Technology Data Exchange (ETDEWEB)

    Yaklin, Melissa A.; Cote, Raymond O.; Moffat, Harry K.; Grillet, Anne Mary; Walker, Lynn; Koehler, Timothy P.; Reichert, Matthew D. (Carnegie Mellon University, Pittsburgh, PA); Castaneda, Jaime N.; Mondy, Lisa Ann; Brooks, Carlton, F.

    2010-11-01

    We have developed a mature laboratory at Sandia to measure interfacial rheology, using a combination of home-built, commercially available, and customized commercial tools. An Interfacial Shear Rheometer (KSV ISR-400) was modified and the software improved to increase sensitivity and reliability. Another shear rheometer, a TA Instruments AR-G2, was equipped with a du Nouey ring, bicone geometry, and a double wall ring. These interfacial attachments were compared to each other and to the ISR. The best results with the AR-G2 were obtained with the du Nouey ring. A Micro-Interfacial Rheometer (MIR) was developed in house to obtain the much higher sensitivity given by a smaller probe. However, it was found to be difficult to apply this technique for highly elastic surfaces. Interfaces also exhibit dilatational rheology when the interface changes area, such as occurs when bubbles grow or shrink. To measure this rheological response we developed a Surface Dilatational Rheometer (SDR), in which changes in surface tension with surface area are measured during the oscillation of the volume of a pendant drop or bubble. All instruments were tested with various surfactant solutions to determine the limitations of each. In addition, foaming capability and foam stability were tested and compared with the rheology data. It was found that there was no clear correlation of surface rheology with foaming/defoaming with different types of surfactants, but, within a family of surfactants, rheology could predict the foam stability. Diffusion of surfactants to the interface and the behavior of polyelectrolytes were two subjects studied with the new equipment. Finally, surface rheological terms were added to a finite element Navier-Stokes solver and preliminary testing of the code completed. Recommendations for improved implementation were given. When completed we plan to use the computations to better interpret the experimental data and account for the effects of the underlying bulk

  20. Internet Addiction: Stability and Change

    Science.gov (United States)

    Huang, Chiungjung

    2010-01-01

    This longitudinal study examined five indices of stability and change in Internet addiction: structural stability, mean-level stability, differential stability, individual-level stability, and ipsative stability. The study sample was 351 undergraduate students from end of freshman year to end of junior year. Convergent findings revealed stability…

  1. Criteria for Second Stability for Ballooning Modes in Stellarators

    International Nuclear Information System (INIS)

    Hudson, S.R.; Hegna, C.C.

    2004-01-01

    An expression determining how variations in the pressure-gradient and average magnetic shear affect ballooning stability for a stellarator equilibrium is presented. The procedure for determining the marginal stability boundaries, for each field line, depends only on the equilibrium and a single ballooning eigenfunction calculation. This information is sufficient to determine if increasing pressure-gradient is stabilizing or destabilizing and to predict whether the configuration possess a second stable region

  2. Stability analysis of fuzzy parametric uncertain systems.

    Science.gov (United States)

    Bhiwani, R J; Patre, B M

    2011-10-01

    In this paper, the determination of stability margin, gain and phase margin aspects of fuzzy parametric uncertain systems are dealt. The stability analysis of uncertain linear systems with coefficients described by fuzzy functions is studied. A complexity reduced technique for determining the stability margin for FPUS is proposed. The method suggested is dependent on the order of the characteristic polynomial. In order to find the stability margin of interval polynomials of order less than 5, it is not always necessary to determine and check all four Kharitonov's polynomials. It has been shown that, for determining stability margin of FPUS of order five, four, and three we require only 3, 2, and 1 Kharitonov's polynomials respectively. Only for sixth and higher order polynomials, a complete set of Kharitonov's polynomials are needed to determine the stability margin. Thus for lower order systems, the calculations are reduced to a large extent. This idea has been extended to determine the stability margin of fuzzy interval polynomials. It is also shown that the gain and phase margin of FPUS can be determined analytically without using graphical techniques. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Photooxidation stability of microcapsules in thermochromic prints

    Directory of Open Access Journals (Sweden)

    Mirela Rozic

    2018-03-01

    Full Text Available In this paper, photochemical stability of two thermochromic prints was investigated: vegetable oil based offset and UV curing screen printing ink. The obtained preliminary results can be used for further detailed examination of prints stability. It is well known that thermochromic printing inks are very unstabile when exsposed to UV irradiance and this is why they are mainly used for applications that are not directly exposed to sunlight. The results of the study show the heterogeneous nature of photooxidative degradation of thermochromic prints, and the opposite behaviour of photooxidation can be noticed comparing examined prints. Microcapsules in the UV curable screen print by fixation with polar polymer binder can create a new products stable to photoxidation. For this reason, the areas where the microcapsules and binder are bonded together are stable. Degraded only areas where binder is not related to microcapsules. Microcapsules in offset print do not have the ability to create new stabile forms due to smaller polarity and different chemical composition of the offset oxidized binder. In the offset print, the microcapsules are the least photooxidative stable and also cause lower photooxidative stability of the binder in contact with them. Cavities are formed in the areas where microcapsules are in contact with the binder, while the areas in which the binder is not in contact with microcapsules are not degraded.

  4. AECL's excavation stability study - summary of observations

    International Nuclear Information System (INIS)

    Read, R.S.; Chandler, N.A.

    1996-05-01

    The Excavation Stability Study (ESS) was conducted at the 420 Level of the Underground Research Laboratory (URL) to evaluate stability and the extent of excavation damage in tunnels as a function of tunnel geometry and orientation, geology, and excavation method. A series of ovaloid and circular openings were used to achieve different boundary stress levels and near-field stress distributions to assess the effect of tunnel geometry on damage development. Several of these openings had sections in both granite and granodiorite lithology, providing a comparison of damage in rock types with different strength characteristics. Damage around circular tunnels (one excavated by drill-and-blast, the other by mechanical means) was also investigated. The study.showed that mechanically stable openings can be excavated in the most adverse stress conditions at the 420 Level of the URL. In addition, it was shown that tunnel stability is sensitive to tunnel shape, variations in geology, and to some extent, the excavation method. Findings of the study are relevant in developing design criteria, and in assessing the feasibility of constructing large ovaloid openings in adverse stress conditions. This report summarizes the preliminary observations related to tunnel stability and excavation damage. (author). 8 refs., 7 tabs., 23 figs

  5. Approximate Method of Calculating Forces on Rudder During Ship Sailing on a Shipping Route

    Directory of Open Access Journals (Sweden)

    K. Zelazny

    2014-09-01

    Full Text Available Service speed of a ship in real weather conditions is a basic design parameter. Forecasting of this speed at preliminary design stage is made difficult by the lack of simple but at the same accurate models of forces acting upon a ship sailing on a preset shipping route. The article presents a model for calculating forces and moment on plane rudder, useful for forecasting of ship service speed at preliminary stages of ship design.

  6. Ionizing radiation calculations and comparisons with LDEF data

    Science.gov (United States)

    Armstrong, T. W.; Colborn, B. L.; Watts, J. W., Jr.

    1992-01-01

    In conjunction with the analysis of LDEF ionizing radiation dosimetry data, a calculational program is in progress to aid in data interpretation and to assess the accuracy of current radiation models for future mission applications. To estimate the ionizing radiation environment at the LDEF dosimeter locations, scoping calculations for a simplified (one dimensional) LDEF mass model were made of the primary and secondary radiations produced as a function of shielding thickness due to trapped proton, galactic proton, and atmospheric (neutron and proton cosmic ray albedo) exposures. Preliminary comparisons of predictions with LDEF induced radioactivity and dose measurements were made to test a recently developed model of trapped proton anisotropy.

  7. Effect of dynamic surface polarization on the oxidative stability of solvents in nonaqueous Li-O 2 batteries

    Science.gov (United States)

    Khetan, Abhishek; Pitsch, Heinz; Viswanathan, Venkatasubramanian

    2017-09-01

    Polarization-induced renormalization of the frontier energy levels of interacting molecules and surfaces can cause significant shifts in the excitation and transport behavior of electrons. This phenomenon is crucial in determining the oxidative stability of nonaqueous electrolytes in high-energy density electrochemical systems such as the Li-O2 battery. On the basis of partially self-consistent first-principles Sc G W0 calculations, we systematically study how the electronic energy levels of four commonly used solvent molecules, namely, dimethylsulfoxide (DMSO), dimethoxyethane (DME), tetrahydrofuran (THF), and acetonitrile (ACN), renormalize when physisorbed on the different stable surfaces of Li2O2 , the main discharge product. Using band level alignment arguments, we propose that the difference between the solvent's highest occupied molecular orbital (HOMO) level and the surface's valence-band maximum (VBM) is a refined metric of oxidative stability. This metric and a previously used descriptor, solvent's gas phase HOMO level, agree quite well for physisorbed cases on pristine surfaces where ACN is oxidatively most stable followed by DME, THF, and DMSO. However, this effect is intrinsically linked to the surface chemistry of the solvent's interaction with the surface states and defects, and depends strongly on their nature. We conclusively show that the propensity of solvent molecules to oxidize will be significantly higher on Li2O2 surfaces with defects as compared to pristine surfaces. This suggests that the oxidative stability of a solvent is dynamic and is a strong function of surface electronic properties. Thus, while gas phase HOMO levels could be used for preliminary solvent candidate screening, a more refined picture of solvent stability requires mapping out the solvent stability as a function of the state of the surface under operating conditions.

  8. Preliminary design county plan Zeeland

    International Nuclear Information System (INIS)

    1987-01-01

    The preliminary design 'Streekplan Zeeland' (Country plan Zeeland, with regard to the location of additional nuclear power plants in Zeeland, the Netherlands) has passed through a consultation and participation round. Thereupon 132 reactions have been received. These have been incorporated and answered in two notes. This proposal deals with the principal points of the preliminary design and treats also the remarks of the committees Environmental (town and country) Planning (RO), Provincial (town and country) Planning Committee (PPC) and Association of Communities of Zeeland (VZG), on the reply notes. The preliminary design with the modifications, collected in appendix 3, is proposed to be the starting point in the drawing-up of the design-country-plan. This design subsequently will pass the formal country-plan procedure. (author). 1 fig

  9. The trade experiment: Shielding calculations for the building hosting the subcritical system

    International Nuclear Information System (INIS)

    Burn, K. W.; Carta, M.; Casalini, L.; Kadi, Y.; Monti, S.; Nava, E.; Palomba, M.; Petrovich, C.; Picardi, L.; Rubbia, C.; Troiani, F.

    2005-01-01

    The TRADE project (TRIGA Accelerator Driven Experiment), to be performed at the existing TRIGA reactor at ENEA Casaccia, has been proposed as a validation of the accelerator-driven system (ADS) concept. TRADE will be the first experiment in which the three main components of an ADS-the accelerator, spallation target and sub-critical blanket-are coupled at a power level sufficient to encounter reactivity feedback effects. As such, TRADE represents the necessary intermediate step in the development of hybrid transmutation systems, its expected outcomes being considered crucial-in terms of proof of stability of operation, dynamic behaviour and licensing issues-for the subsequent realisation of an ADS Transmutation Demonstrator. An essential role in the feasibility study of the experiment is played by radioprotection calculations. Such a system exhibits new characteristics with respect to a traditional reactor, owing to the presence of the proton accelerator. As beam losses always occur under normal operating conditions of an accelerator, shielding studies need to be performed not only around the reactor but also along the beam line from the accelerator to the spallation target. This paper illustrates a preliminary evaluation, using Monte Carlo methods, of the additional shielding to be located around the reactor structures, the beam transport line and the existing reactor building to allow access into the reactor hall and to restrict the doses outside to their legal limits. (authors)

  10. 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)

  11. Experimental Young's modulus calculations

    International Nuclear Information System (INIS)

    Chen, Y.; Jayakumar, R.; Yu, K.

    1994-01-01

    Coil is a very important magnet component. The turn location and the coil size impact both mechanical and magnetic behavior of the magnet. The Young's modulus plays a significant role in determining the coil location and size. Therefore, Young's modulus study is essential in predicting both the analytical and practical magnet behavior. To determine the coil Young's modulus, an experiment has been conducted to measure azimuthal sizes of a half quadrant QSE101 inner coil under different loading. All measurements are made at four different positions along an 8-inch long inner coil. Each measurement is repeated three times to determine the reproducibility of the experiment. To ensure the reliability of this experiment, the same measurement is performed twice with a open-quotes dummy coil,close quotes which is made of G10 and has the same dimension and similar azimuthal Young's modulus as the inner coil. The difference between the G10 azimuthal Young's modulus calculated from the experiments and its known value from the manufacturer will be compared. Much effort has been extended in analyzing the experimental data to obtain a more reliable Young's modulus. Analysis methods include the error analysis method and the least square method

  12. Relativistic few body calculations

    International Nuclear Information System (INIS)

    Gross, F.

    1988-01-01

    A modern treatment of the nuclear few-body problem must take into account both the quark structure of baryons and mesons, which should be important at short range, and the relativistic exchange of mesons, which describes the long range, peripheral interactions. A way to model both of these aspects is described. The long range, peripheral interactions are calculated using the spectator model, a general approach in which the spectators to nucleon interactions are put on their mass-shell. Recent numerical results for a relativistic OBE model of the NN interaction, obtained by solving a relativistic equation with one-particle on mass-shell, will be presented and discussed. Two meson exchange models, one with only four mesons (π,σ,/rho/,ω) but with a 25% admixture of γ 5 coupling for the pion, and a second with six mesons (π,σ,/rho/,ω,δ,/eta/) but pure γ 5 γ/sup μ/ pion coupling, are shown to give very good quantitative fits to the NN scattering phase shifts below 400 MeV, and also a good description of the /rvec p/ 40 Ca elastic scattering observables. Applications of this model to electromagnetic interactions of the two body system, with emphasis on the determination of relativistic current operators consistent with the dynamics and the exact treatment of current conservation in the presence of phenomenological form factors, will be described. 18 refs., 8 figs

  13. Equilibrium calculations, ch. 6

    International Nuclear Information System (INIS)

    Deursen, A.P.J. van

    1976-01-01

    A calculation is presented of dimer intensities obtained in supersonic expansions. There are two possible limiting considerations; the dimers observed are already present in the source, in thermodynamic equilibrium, and are accelerated in the expansion. Destruction during acceleration is neglected, as are processes leading to newly formed dimers. On the other hand one can apply a kinetic approach, where formation and destruction processes are followed throughout the expansion. The difficulty of this approach stems from the fact that the density, temperature and rate constants have to be known at all distances from the nozzle. The simple point of view has been adopted and the measured dimer intensities are compared with the equilibrium concentration in the source. The comparison is performed under the assumption that the detection efficiency for dimers is twice the detection efficiency for monomers. The experimental evidence against the simple point of view that the dimers of the onset region are formed in the source already, under equilibrium conditions, is discussed. (Auth.)

  14. Configuration space Faddeev calculations

    International Nuclear Information System (INIS)

    Payne, G.L.; Klink, W.H.; Ployzou, W.N.

    1991-01-01

    The detailed study of few-body systems provides one of the most precise tools for studying the dynamics of nuclei. Our research program consists of a careful theoretical study of the nuclear few-body systems. During the past year we have completed several aspects of this program. We have continued our program of using the trinucleon system to investigate the validity of various realistic nucleon-nucleon potentials. Also, the effects of meson-exchange currents in nuclear systems have been studied. Initial calculations using the configuration-space Faddeev equations for nucleon-deuteron scattering have been completed. With modifications to treat relativistic systems, few-body methods can be applied to phenomena that are sensitive to the structure of the individual hadrons. We have completed a review of Relativistic Hamiltonian Dynamics in Nuclear and Particle Physics for Advances in Nuclear Physics. Although it is called a review, it is a large document that contains a significant amount of new research

  15. Space reactor preliminary mechanical design

    International Nuclear Information System (INIS)

    Meier, K.L.

    1983-01-01

    An analysis was performed on the SABRE reactor space power system to determine the effect of the number and size of heat pipes on the design parameters of the nuclear subsystem. Small numbers of thin walled heat pipes were found to give a lower subsystem mass, but excessive fuel swelling resulted. The SP-100 preliminary design uses 120 heat pipes because of acceptable fuel swelling and a minimum nuclear subsystem mass of 1875 kg. Salient features of the reactor preliminary design are: individual fuel modules, ZrO 2 block core mounts, bolted collar fuel module restraints, and a BeO central plug

  16. Technetium removal: preliminary flowsheet options

    International Nuclear Information System (INIS)

    Eager, K.M.

    1995-01-01

    This document presents the results of a preliminary investigation into options for preliminary flowsheets for 99Tc removal from Hanford Site tank waste. A model is created to show the path of 99Tc through pretreatment to disposal. The Tank Waste Remediation (TWRS) flowsheet (Orme 1995) is used as a baseline. Ranges of important inputs to the model are developed, such as 99Tc inventory in the tanks and important splits through the TWRS flowsheet. Several technetium removal options are discussed along with sensitivities of the removal schemes to important model parameters

  17. Microwave stability at transition

    International Nuclear Information System (INIS)

    Holt, J.A.; Colestock, P.L.

    1995-05-01

    The question of microwave stability at transition is revisited using a Vlasov approach retaining higher order terms in the particle dynamics near the transition energy. A dispersion relation is derived which can be solved numerically for the complex frequency in terms of the longitudinal impedance and other beam parameters. Stability near transition is examined and compared with simulation results

  18. Beam stabilization at SPEAR

    International Nuclear Information System (INIS)

    Corbett, J.

    1996-01-01

    The SPEAR storage ring began routine synchrotron radiation operation with a dedicated injector in 1990. Since then, a program to improve beam stability has steadily progressed. This paper, based on a seminar given at a workshop on storage ring optimization (1995 SRI conference) reviews the beam stability program for SPEAR. copyright 1996 American Institute of Physics

  19. Visual attention and stability

    NARCIS (Netherlands)

    Mathot, Sebastiaan; Theeuwes, Jan

    2011-01-01

    In the present review, we address the relationship between attention and visual stability. Even though with each eye, head and body movement the retinal image changes dramatically, we perceive the world as stable and are able to perform visually guided actions. However, visual stability is not as

  20. Electrode stabilizing materials

    Science.gov (United States)

    Amine, Khalil; Abouimrane, Ali; Moore, Jeffrey S.; Odom, Susan A.

    2015-11-03

    An electrolyte includes a polar aprotic solvent; an alkali metal salt; and an electrode stabilizing compound that is a monomer, which when polymerized forms an electrically conductive polymer. The electrode stabilizing compound is a thiophene, a imidazole, a anilines, a benzene, a azulene, a carbazole, or a thiol. Electrochemical devices may incorporate such electrolytes.

  1. Homological stabilizer codes

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Jonas T., E-mail: jonastyleranderson@gmail.com

    2013-03-15

    In this paper we define homological stabilizer codes on qubits which encompass codes such as Kitaev's toric code and the topological color codes. These codes are defined solely by the graphs they reside on. This feature allows us to use properties of topological graph theory to determine the graphs which are suitable as homological stabilizer codes. We then show that all toric codes are equivalent to homological stabilizer codes on 4-valent graphs. We show that the topological color codes and toric codes correspond to two distinct classes of graphs. We define the notion of label set equivalencies and show that under a small set of constraints the only homological stabilizer codes without local logical operators are equivalent to Kitaev's toric code or to the topological color codes. - Highlights: Black-Right-Pointing-Pointer We show that Kitaev's toric codes are equivalent to homological stabilizer codes on 4-valent graphs. Black-Right-Pointing-Pointer We show that toric codes and color codes correspond to homological stabilizer codes on distinct graphs. Black-Right-Pointing-Pointer We find and classify all 2D homological stabilizer codes. Black-Right-Pointing-Pointer We find optimal codes among the homological stabilizer codes.

  2. Stabilized radiographic scanning agent

    International Nuclear Information System (INIS)

    Fawzi, M.B.

    1979-01-01

    A stable composition useful in preparation of technetium-99m-based radiographic scanning agents has been developed. The composition contains a stabilizing amount of gentisate stabilizer selected from gentisic acid and its soluble pharmaceutically-acceptable salts and esthers. (E.G.)

  3. Problems support economic stability

    OpenAIRE

    Tkach, Ivan

    2012-01-01

    . The article is devoted to summarizing the approaches to the classification of the stability of the state's economy, identifying the main characteristics, and offers the author's vision for the classification of the stability of the economy of the state under various conditions of operation.

  4. Stability of multihypernuclear objects

    International Nuclear Information System (INIS)

    Ikram, M.; Rather, Asloob A.; Usmani, A.A.; Patra, S.K.

    2016-01-01

    In present work, we analyze the stability of multi-hypernuclear objects having higher content of strangeness. The aim of this work is to test the stability of such objects which might be produced in heavy-ion reactions. Studies of such type of systems might have great implication to nuclear-astrophysics

  5. Conformational stability of calreticulin

    DEFF Research Database (Denmark)

    Jørgensen, C.S.; Trandum, C.; Larsen, N.

    2005-01-01

    The conformational stability of calreticulin was investigated. Apparent unfolding temperatures (T-m) increased from 31 degrees C at pH 5 to 51 degrees C at pH 9, but electrophoretic analysis revealed that calreticulin oligomerized instead of unfolding. Structural analyses showed that the single C......-terminal a-helix was of major importance to the conformational stability of calreticulin....

  6. Stability of Organic Nanowires

    DEFF Research Database (Denmark)

    Balzer, F.; Schiek, M.; Wallmann, I.

    2011-01-01

    The morphological stability of organic nanowires over time and under thermal load is of major importance for their use in any device. In this study the growth and stability of organic nanowires from a naphthyl end-capped thiophene grown by organic molecular beam deposition is investigated via ato...

  7. Geochemical Investigations of Groundwater Stability

    International Nuclear Information System (INIS)

    Bath, Adrian

    2006-05-01

    groundwaters, and also by stable isotopes and uranium isotopes in secondary minerals. Information on timing of water and solute movements is important because it indicates any correlation with the timing of external events that might have perturbed and destabilised the groundwater system in the past, and allows a timescale to be estimated for the persistence of stable conditions. Data from a number of published site investigation projects and research programmes are reviewed to illustrate the patterns of geochemical data and the relationships between them, and how these are interpreted in terms of hydrodynamic stability. Data from Aespoe and Stripa and from exploratory boreholes at Finnsjoen and other sites in Sweden are compiled and discussed. Preliminary data from SKB's ongoing site investigations at Simpevarp/Laxemar and Forsmark are not considered in detail but their general similarities with Aespoe and Finnsjoen/SFR respectively are introduced into the discussion of geochemical evidence for groundwater stability in inland and coastal areas. Relevant data from Finnish sites including Olkiluoto, from the Whiteshell URL area in Canada, from Sellafield in the UK, and from the Tono area and URL in Japan are also summarised in appendices and discussed because they add further insights into the interpretation of geochemical indicators for a range of geological environments. The compiled data provide only limited scope for comparison of groundwater evolution and stability between inland and coastal areas in Sweden, because of the patchiness of representative data especially from early site studies. The external changes that might have perturbed stable groundwater conditions in the past are glaciation (i.e. melt water, mechanical loading/unloading and permafrost) and varying sea water infiltration at coastal sites due to changes in palaeo-Baltic and isostatic conditions. The present distributions of palaeo-Baltic sea water in groundwaters at coastal sites vary, reflecting local

  8. Geochemical Investigations of Groundwater Stability

    Energy Technology Data Exchange (ETDEWEB)

    Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

    2006-05-15

    groundwaters, and also by stable isotopes and uranium isotopes in secondary minerals. Information on timing of water and solute movements is important because it indicates any correlation with the timing of external events that might have perturbed and destabilised the groundwater system in the past, and allows a timescale to be estimated for the persistence of stable conditions. Data from a number of published site investigation projects and research programmes are reviewed to illustrate the patterns of geochemical data and the relationships between them, and how these are interpreted in terms of hydrodynamic stability. Data from Aespoe and Stripa and from exploratory boreholes at Finnsjoen and other sites in Sweden are compiled and discussed. Preliminary data from SKB's ongoing site investigations at Simpevarp/Laxemar and Forsmark are not considered in detail but their general similarities with Aespoe and Finnsjoen/SFR respectively are introduced into the discussion of geochemical evidence for groundwater stability in inland and coastal areas. Relevant data from Finnish sites including Olkiluoto, from the Whiteshell URL area in Canada, from Sellafield in the UK, and from the Tono area and URL in Japan are also summarised in appendices and discussed because they add further insights into the interpretation of geochemical indicators for a range of geological environments. The compiled data provide only limited scope for comparison of groundwater evolution and stability between inland and coastal areas in Sweden, because of the patchiness of representative data especially from early site studies. The external changes that might have perturbed stable groundwater conditions in the past are glaciation (i.e. melt water, mechanical loading/unloading and permafrost) and varying sea water infiltration at coastal sites due to changes in palaeo-Baltic and isostatic conditions. The present distributions of palaeo-Baltic sea water in groundwaters at coastal sites vary, reflecting

  9. Effects of corn cob ash on lime stabilized lateritic soil

    Science.gov (United States)

    Nnochiri, Emeka Segun

    2018-03-01

    This study assesses the effects of Corn Cob Ash (CCA) on lime-stabilized lateritic soil. Preliminary tests were carried out on the natural soil sample for purpose of identification and classification. Lime being the main stabilizing material was thoroughly mixed with the soil sample to determine the optimum lime requirement of the sample as a basis for evaluating the effects of the CCA. The optimum lime requirement was 10%. The CCA was thereafter added to the lime stabilized soil in varying proportions of 2, 4, 6, 8 and 10%. Unsoaked CBR increased from 83% at 0% CCA to highest value of 94% at 4% CCA. Unconfined Compressive Strength (UCS) values increased from 1123kN/m2 at 0% CCA to highest value of 1180kN/m2 at 4% CCA. It was therefore concluded that CCA can serve as a good complement for lime stabilization in lateritic soil.

  10. Stabilization of atoms with nonzero magnetic quantum numbers

    International Nuclear Information System (INIS)

    Sundaram, B.; Jensen, R.V.

    1993-01-01

    A classical analysis of the interaction of an atomic electron with an oscillating electric field with arbitrary initial quantum number, n, magnetic quantum number, m > 0, field strength, and frequency shows that the classical, dynamics for the perturbed electron can be stabilized for large fields and high frequencies. Using a four-dimensional map approximation to the classical dynamics, explicit expressions are obtained for the full parameter dependence of the boundaries of stability surrounding the open-quotes death valleyclose quotes of rapid classical ionization. A preliminary analysis of the quantum dynamics in terms of the quasienergy states associated with the corresponding quantum map is also included with particular emphasis on the role of unstable classical structures in stabilizing atoms. Together, these results provide motivation and direction for further theoretical and experimental studies of stabilization of atoms (and molecules) in super-intense microwave and laser fields

  11. Electrostatically driven resonance energy transfer in ?cationic? biocompatible indium phosphide quantum dots? ?Electronic supplementary information (ESI) available: Detailed experimental methods, the synthesis and characterization of QDs, bioimaging, stability studies, control experiments, and the calculation of various parameters involved in the resonance energy transfer process etc. See DOI: 10.1039/c7sc00592j Click here for additional data file.

    OpenAIRE

    Devatha, Gayathri; Roy, Soumendu; Rao, Anish; Mallick, Abhik; Basu, Sudipta; Pillai, Pramod P.

    2017-01-01

    Indium Phosphide Quantum Dots (InP QDs) have emerged as an alternative to toxic metal ion based QDs in nanobiotechnology. The ability to generate cationic surface charge, without compromising stability and biocompatibility, is essential in realizing the full potential of InP QDs in biological applications. We have addressed this challenge by developing a place exchange protocol for the preparation of cationic InP/ZnS QDs. The quaternary ammonium group provides the much required permanent posi...

  12. The statistical stability phenomenon

    CERN Document Server

    Gorban, Igor I

    2017-01-01

    This monograph investigates violations of statistical stability of physical events, variables, and processes and develops a new physical-mathematical theory taking into consideration such violations – the theory of hyper-random phenomena. There are five parts. The first describes the phenomenon of statistical stability and its features, and develops methods for detecting violations of statistical stability, in particular when data is limited. The second part presents several examples of real processes of different physical nature and demonstrates the violation of statistical stability over broad observation intervals. The third part outlines the mathematical foundations of the theory of hyper-random phenomena, while the fourth develops the foundations of the mathematical analysis of divergent and many-valued functions. The fifth part contains theoretical and experimental studies of statistical laws where there is violation of statistical stability. The monograph should be of particular interest to engineers...

  13. The rating reliability calculator

    Directory of Open Access Journals (Sweden)

    Solomon David J

    2004-04-01

    Full Text Available Abstract Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program.

  14. Experimental and theoretical studies on stability of new stabilizers for N-methyl-P-nitroaniline derivative in CMDB propellants

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Qiufan [Xi’an Modern Chemistry Research Institute, Xi’an 710065 (China); Fan, Xuezhong, E-mail: xuezhongfan@126.com [Xi’an Modern Chemistry Research Institute, Xi’an 710065 (China); Li, Jizhen [Xi’an Modern Chemistry Research Institute, Xi’an 710065 (China); Key Laboratory of Applied Surface and Colloid Chemistry, MOE/School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062 (China); Bi, Fuqiang; Fu, Xiaolong; Zhai, Lianjie [Xi’an Modern Chemistry Research Institute, Xi’an 710065 (China)

    2017-04-05

    Highlights: • Five new stabilizers have been designed and synthesized. • The influence of the carbon chain length on the stability of propellants was studied. • Effects of temperature on the reactions of stabilizers and nitrogen oxides were explained. • The new stabilizer n-BNA was one of the most promising stabilizers. - Abstract: Although N-methyl-P-nitroaniline (MNA) was a quite effective stabilizer in composite modified double base (CMDB) propellants, it undergoes crystallization easily from nitroglycerin (NG) during storage. In order to improve its solubility in nitroglycerin (NG) and the stability in propellants, several new stabilizers including N-ethyl-p-nitroaniline (ENA), N-n-propyl-p-nitroaniline (n-PNA), N-i-propyl-p-nitroaniline (i-PNA), N-n-butyl-p-nitroaniline (n-BNA) and N-t-butyl-p-nitroaniline (t-BNA) were designed and synthesized to replace MNA by increasing the carbon chain length. The interaction between NG and different stabilizers was simulation by Materials Studio 5.5 and the stability and the high temperature stability performance of those new stabilizers in propellants were calculated by Gaussian 09. It was found that both the solubility of new stabilizers in NG and the stability and the high temperature stability performance of those in propellants were improved when the carbon chain length of substitution groups on nitrogen atom was increased. Thus, the n-BNA was a most potential stabilizer. Then all properties of the stabilizers were studied experimentally, which was agreement well with the theoretical analysis.

  15. Computation of stabilizing PI and PID controllers using the stability boundary locus

    International Nuclear Information System (INIS)

    Tan, Nusret; Kaya, Ibrahim; Yeroglu, Celaleddin; Atherton, Derek P.

    2006-01-01

    In this paper, a new method for the calculation of all stabilizing PI controllers is given. The proposed method is based on plotting the stability boundary locus in the (k p , k i )-plane and then computing the stabilizing values of the parameters of a PI controller. The technique presented does not require sweeping over the parameters and also does not need linear programming to solve a set of inequalities. Thus it offers several important advantages over existing results obtained in this direction. Beyond stabilization, the method is used to shift all poles to a shifted half plane that guarantees a specified settling time of response. Computation of stabilizing PI controllers which achieve user specified gain and phase margins is studied. It is shown via an example that the stabilizing region in the (k p , k i )-plane is not always a convex set. The proposed method is also used to design PID controllers. The limiting values of a PID controller which stabilize a given system are obtained in the (k p , k i )-plane (k p , k d )-plane and (k i , k d )-plane. Furthermore, the proposed method is used to compute all the parameters of a PI controller which stabilize a control system with an interval plant family. Examples are given to show the benefits of the method presented

  16. Stability of casein micelles in milk

    Science.gov (United States)

    Tuinier, R.; de Kruif, C. G.

    2002-07-01

    Casein micelles in milk are proteinaceous colloidal particles and are essential for the production of flocculated and gelled products such as yogurt, cheese, and ice-cream. The colloidal stability of casein micelles is described here by a calculation of the pair potential, containing the essential contributions of brush repulsion, electrostatic repulsion, and van der Waals attraction. The parameters required are taken from the literature. The results are expressed by the second osmotic virial coefficient and are quite consistent with experimental findings. It appears that the stability is mainly attributable to a steric layer of κ-casein, which can be described as a salted polyelectrolyte brush.

  17. Sawteeth stabilization by energetic trapped ions

    International Nuclear Information System (INIS)

    Samain, A.; Edery, D.; Garbet, X.; Roubin, J.P.

    1991-01-01

    The analysis of a possible stabilization of sawteeth by a population of energetic ions is performed by using the Lagrangian of the electromagnetic perturbation. It is shown that the trapped component of such a population has a small influence compared to that of the passing component. The stabilization threshold is calculated assuming a non linear regime in the q=1 resonant layer. The energetic population must create a stable tearing structure if the average curvature effect on thermal particles in the layer is small. However, this effect decreases the actual threshold

  18. Structural Stability of Low-Crested Breakwaters

    DEFF Research Database (Denmark)

    Kramer, Morten

    equations. New improved design formulae for calculation of static stability of LCS's are developed on the basis of new 2D and 3D laboratory experiments with scale models. The formulae are specially designed for breakwaters subject to shallow water waves and/or depth limited waves, as the majority...... of existing LCS’s are exposed to such conditions. The formulae are validated against prototype experience. Ecological aspects in relation to structural stability are important, and design guidance on how to consider ecology in the design is therefore given. The new design guidance adds practical and helpful...

  19. Heat of mixing and morphological stability

    Science.gov (United States)

    Nandapurkar, P.; Poirier, D. R.

    1988-01-01

    A mathematical model, which incorporates heat of mixing in the energy balance, has been developed to analyze the morphological stability of a planar solid-liquid interface during the directional solidification of a binary alloy. It is observed that the stability behavior is almost that predicted by the analysis of Mullins and Sekerka (1963) at low growth velocities, while deviations in the critical concentration of about 20-25 percent are observed under rapid solidification conditions for certain systems. The calculations indicate that a positive heat of mixing makes the planar interface more unstable, whereas a negative heat of mixing makes it more stable, in terms of the critical concentration.

  20. Preliminary HECTOR analysis by Dragon

    Energy Technology Data Exchange (ETDEWEB)

    Presser, W; Woloch, F

    1972-06-02

    From the different cores measured in HECTOR, only ACH 4/B-B was selected for the Dragon analysis, since it presented the largest amount of uniform fuel loading in the central test region and is therefore nearest to an infinite lattice. Preliminary results are discussed.