Science.gov

Sample records for production rate calculations

  1. Production rate calculations for a secondary beam facility

    SciTech Connect

    Jiang, C.L.; Back, B.B.; Rehm, K.E.

    1995-08-01

    In order to select the most cost-effective method for the production of secondary ion beams, yield calculations for a variety of primary beams were performed ranging in mass from protons to {sup 18}O with energies of 100-200 MeV/u. For comparison, production yields for 600-1000 MeV protons were also calculated. For light ion-(A < {sup 4}He) induced reactions at energies above 50 MeV/u the LAHET code was used while the low energy calculations were performed with LPACE. Heavy-ion-induced production rates were calculated with the ISAPACE program. The results of these codes were checked against each other and wherever possible a comparison with experimental data was performed. These comparisons extended to very exotic reaction channels, such as the production of {sup 100}Sn from {sup 112}Sn and {sup 124}Xe induced fragmentation reactions. These comparisons indicate that the codes are able to predict production rates to within one order of magnitude.

  2. Neutrons in the moon. [neutron flux and production rate calculations

    NASA Technical Reports Server (NTRS)

    Kornblum, J. J.; Fireman, E. L.; Levine, M.; Aronson, A.

    1973-01-01

    Neutron fluxes for energies between 15 MeV and thermal at depths of 0 to 300 g/sq cm in the moon are calculated by the discrete ordinate mathod with the ANISN code. With the energy spectrum of Lingenfelter et al. (1972). A total neutron-production rate for the moon of 26 plus or minus neutrons/sq cm sec is determined from the Ar-37 activity measurements in the Apollo 16 drill string, which are found to have a depth dependence in accordance with a neutron source function that decreases exponentially with an attenuation length of 155 g/sq cm.

  3. Target Heart Rate Calculator

    MedlinePlus

    ... My Saved Articles » My ACS » + - Text Size Target Heart Rate Calculator Compute your best workout Enter your age ... is your age? years. How to Check Your Heart Rate Right after you stop exercising, take your pulse: ...

  4. Revised Calculations of the Production Rates for Co Isotopes in Meteorites Using New Cross Sections for Neutron-induced Reactions

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.; Brooks, F. D.; Buffler, A.; Allie, M. S.; Herbert, M. S.; Nchodu, M. R.; Makupula, S.; Ullmann, J.; Reedy, R. C.; Jones, D. T. L.

    2002-01-01

    New cross section measurements for reactions induced by neutrons with energies greater than 70 MeV are used to calculate the production rates for cobalt isotopes in meteorites and these new calculations are compared to previous estimates. Additional information is contained in the original extended abstract.

  5. 19 CFR 351.525 - Calculation of ad valorem subsidy rate and attribution of subsidy to a product.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Calculation of ad valorem subsidy rate and attribution of subsidy to a product. 351.525 Section 351.525 Customs Duties INTERNATIONAL TRADE ADMINISTRATION... destination (e.g., freight or insurance costs are subsidized), the Secretary may make appropriate...

  6. 19 CFR 351.525 - Calculation of ad valorem subsidy rate and attribution of subsidy to a product.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Calculation of ad valorem subsidy rate and attribution of subsidy to a product. 351.525 Section 351.525 Customs Duties INTERNATIONAL TRADE ADMINISTRATION... destination (e.g., freight or insurance costs are subsidized), the Secretary may make appropriate...

  7. Calculating California Seismicity Rates

    USGS Publications Warehouse

    Felzer, Karen R.

    2008-01-01

    Empirically the rate of earthquakes = magnitude M is well fit by the Gutenberg-Richter relationship, logN=a-bM (1) where N is the number of earthquakes = M over a given time period, a is the number of M = 0 earthquakes over the same period, and b is a parameter that determines the ratio of larger to smaller earthquakes (Ishimoto and Iida 1939; Gutenberg and Richter 1944). Thus to characterize the seismicity rate, N, and risk in a given region we need to solve for the values of a and b. Here we are concerned with solving for the long term average values of these parameters for the state of California. My primary data source is a catalog of 1850-2006 M = 4.0 seismicity compiled with Tianqing Cao (Appendix H). Because earthquakes outside of the state can influence California I consider both earthquakes within the state and within 100 km of the state border (Figure 1).

  8. Small Rayed Crater Ejecta Retention Age Calculated from Current Crater Production Rates on Mars

    NASA Technical Reports Server (NTRS)

    Calef, F. J. III; Herrick, R. R.; Sharpton, V. L.

    2011-01-01

    Ejecta from impact craters, while extant, records erosive and depositional processes on their surfaces. Estimating ejecta retention age (Eret), the time span when ejecta remains recognizable around a crater, can be applied to estimate the timescale that surface processes operate on, thereby obtaining a history of geologic activity. However, the abundance of sub-kilometer diameter (D) craters identifiable in high resolution Mars imagery has led to questions of accuracy in absolute crater dating and hence ejecta retention ages (Eret). This research calculates the maximum Eret for small rayed impact craters (SRC) on Mars using estimates of the Martian impactor flux adjusted for meteorite ablation losses in the atmosphere. In addition, we utilize the diameter-distance relationship of secondary cratering to adjust crater counts in the vicinity of the large primary crater Zunil.

  9. Ca-41 in iron falls, Grant and Estherville - Production rates and related exposure age calculations

    NASA Technical Reports Server (NTRS)

    Fink, D.; Klein, J.; Middleton, R.; Vogt, S.; Herzog, G. F.

    1991-01-01

    Results are presented of the first phase of a Ca-41 cosmogenic studies program aimed at establishing baseline concentrations and trends in selected meteorites and the use of Ca-41 in estimating exposure ages and preatmospheric meteorite radii. The average Ca-41 saturation activity recorded in four small iron falls is 24 +/-1 dpm/kg. This finding, together with measurements at the center and surface of the large iron Grant, indicates that production of Ca-41 from spallation on iron is weakly dependent on shielding to depths as large as 250 g/sq cm. The (K-41)-Ca-41 exposure age of Grant is estimated at 330 +/-50 My, and an upper limit to its terrestrial age of 43 +/-15 ky. A comparison of the Ca-41 contents of stony and metallic material separated from the mesosiderite Estherville identifies low-energy neutron capture on native Ca as a second important channel of production. It is found that the Ca-41 signal in the stone phase from three meteorites correlates with their size, and that the inferred low-energy neutron fluxes vary by a factor of at least 20.

  10. Multi-calculation rate simulations

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Akhter, M.

    1977-01-01

    It is common in real time simulations of large aerospace systems to separate the high and low frequency subsystems within the simulation and perform the integrations of the subsystems at different calculation rates. This is done to strike a balance between accuracy of calculation and capacity of the digital computer. Questions arising as to the accuracy of this structure compared to single calculation rates were studied using a linear aircraft model. Also investigated were interactions arising to cause errors worse than those expected. Problems are specifically identified and guidelines are given for selection of sample rates for multiple rate simulations.

  11. Regolith production rates calculated with uranium-series isotopes at Susquehanna/Shale Hills Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Ma, Lin; Chabaux, Francois; Pelt, Eric; Blaes, Estelle; Jin, Lixin; Brantley, Susan

    2010-08-01

    In the Critical Zone where rocks and life interact, bedrock equilibrates to Earth surface conditions, transforming to regolith. The factors that control the rates and mechanisms of formation of regolith, defined here as material that can be augered, are still not fully understood. To quantify regolith formation rates on shale lithology, we measured uranium-series (U-series) isotopes ( 238U, 234U, and 230Th) in three weathering profiles along a planar hillslope at the Susquehanna/Shale Hills Observatory (SSHO) in central Pennsylvania. All regolith samples show significant U-series disequilibrium: ( 234U/ 238U) and ( 230Th/ 238U) activity ratios range from 0.934 to 1.072 and from 0.903 to 1.096, respectively. These values display depth trends that are consistent with fractionation of U-series isotopes during chemical weathering and element transport, i.e., the relative mobility decreases in the order 234U > 238U > 230Th. The activity ratios observed in the regolith samples are explained by i) loss of U-series isotopes during water-rock interactions and ii) re-deposition of U-series isotopes downslope. Loss of U and Th initiates in the meter-thick zone of "bedrock" that cannot be augered but that nonetheless consists of up to 40% clay/silt/sand inferred to have lost K, Mg, Al, and Fe. Apparent equivalent regolith production rates calculated with these isotopes for these profiles decrease exponentially from 45 m/Myr to 17 m/Myr, with increasing regolith thickness from the ridge top to the valley floor. With increasing distance from the ridge top toward the valley, apparent equivalent regolith residence times increase from 7 kyr to 40 kyr. Given that the SSHO experienced peri-glacial climate ˜ 15 kyr ago and has a catchment-wide averaged erosion rate of ˜ 15 m/Myr as inferred from cosmogenic 10Be, we conclude that the hillslope retains regolith formed before the peri-glacial period and is not at geomorphologic steady state. Both chemical weathering reactions of clay

  12. Calculation of molecular excitation rates

    NASA Astrophysics Data System (ADS)

    Flynn, George

    1993-01-01

    State-to-state collisional excitation rates for interstellar molecules observed by radio astronomers continue to be required to interpret observed line intensities in terms of local temperatures and densities. A problem of particular interest is collisional excitation of water which is important for modeling the observed interstellar masers. In earlier work supported by a different NASA Grant, excitation of water in collisions with He atoms was studied; after many years of successively more refined calculations that problem now seems to be well understood, and discrepancies with earlier experimental data for related (pressure broadening) phenomena are believed to reflect experimental errors. Because of interstellar abundances, excitation by H2, the dominant interstellar species, is much more important than excitation by He, although it has been argued that rates for excitation by these are similar. Under the current grant theoretical study of this problem has begun which is greatly complicated by the additional degrees of freedom which must be included both in determining the interaction potential and also in the molecular scattering calculation. We have now computed the interaction forces for nearly a thousand molecular geometries and are close to having an acceptable global fit to these points which is necessary for the molecular dynamics calculations. Also, extensive modifications have been made to the molecular scattering code, MOLSCAT. These included coding the rotational basis sets and coupling matrix elements required for collisions of an asymmetric top with a linear rotor. A new method for numerical solution of the coupled equations has been incorporated. Because of the long-ranged nature of the water-hydrogen interaction it is necessary to integrate the equations to rather large intermolecular separations, and the integration methods previously available in MOLSCAT are not ideal for such cases. However, the method used by Alexander in his HIBRIDON code is

  13. 19 CFR 351.525 - Calculation of ad valorem subsidy rate and attribution of subsidy to a product.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... downstream products produced by a corporation. (6) Corporations with cross-ownership. (i) In general. The... between an input supplier and a downstream producer, and production of the input product is primarily dedicated to production of the downstream product, the Secretary will attribute subsidies received by...

  14. ACTIVE: a program to calculate and plot reaction rates from ANISN calculated fluxes

    SciTech Connect

    Judd, J.L.

    1981-12-01

    The ACTIVE code calculates spatial heating rates, tritium production rates, neutron reaction rates, and energy spectra from particle fluxes calculated by ANISN. ACTIVE has a variety of input options including the capability to plot all calculated spatial distributions. The code was primarily designed for use with fusion first wall/blanket systems, but could be applied to any one-dimensional problem.

  15. A Program for Calculating Radiation Dose Rates.

    1986-01-27

    Version 00 SMART calculates radiation dose rate at the center of the outer cask surface. It can be applied to determine the radiation dose rate on each cask if source conditions, characteristic function, and material conditions in the bottle regions are given. MANYCASK calculates radiation dose rate distribution in a space surrounded by many casks. If the dose rate on each cask surface can be measured, MANYCASK can be applied to predict dose spatial dosemore » rate distribution for any case of cask configuration.« less

  16. Historical river flow rates for dose calculations

    SciTech Connect

    Carlton, W.H.

    1991-06-10

    Annual average river flow rates are required input to the LADTAP Computer Code for calculating offsite doses from liquid releases of radioactive materials to the Savannah River. The source of information on annual river flow rates used in dose calculations varies, depending on whether calculations are for retrospective releases or prospective releases. Examples of these types of releases are: Retrospective - releases from routine operations (annual environmental reports) and short term release incidents that have occurred. Prospective - releases that might be expected in the future from routine or abnormal operation of existing or new facilities (EIS`s, EID`S, SAR`S, etc.). This memorandum provides historical flow rates at the downstream gauging station at Highway 301 for use in retrospective dose calculations and derives flow rate data for the Beaufort-Jasper and Port Wentworth water treatment plants.

  17. Calculations of Polar Ozone Loss Rates

    NASA Technical Reports Server (NTRS)

    Dessler, A. E.; Wu, J.

    1999-01-01

    We calculate vortex-averaged ozone loss rates at 465-K potential temperature during the Aug.-Sept. time period in the southern hemisphere and Feb.-Mar. time period in the northern hemisphere. Ozone loss rates are calculated two ways. First, from the time series of measurements of 03. Second, from measurements of ClO, from which ozone loss is inferred based on our theories of Cl-catalyzed ozone destruction. Both measurement sets are from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) instrument. We find good agreement between vortex-averaged ozone loss rates calculated from these methods. Our analysis provides no support for recent work suggesting that current theories of Cl-catalyzed ozone loss underestimate the observed decrease in polar ozone during the ozone "hole" period.

  18. Cooling rate calculations for silicate glasses.

    NASA Astrophysics Data System (ADS)

    Birnie, D. P., III; Dyar, M. D.

    1986-03-01

    Series solution calculations of cooling rates are applied to a variety of samples with different thermal properties, including an analog of an Apollo 15 green glass and a hypothetical silicate melt. Cooling rates for the well-studied green glass and a generalized silicate melt are tabulated for different sample sizes, equilibration temperatures and quench media. Results suggest that cooling rates are heavily dependent on sample size and quench medium and are less dependent on values of physical properties. Thus cooling histories for glasses from planetary surfaces can be estimated on the basis of size distributions alone. In addition, the variation of cooling rate with sample size and quench medium can be used to control quench rate.

  19. Shuffler bias corrections using calculated count rates

    SciTech Connect

    Rinard, Phillip M.; Hurd, J. R.; Hsue, F.

    2001-04-01

    Los Alamos National Laboratory has two identical shufflers that have been calibrated with a dozen U{sub 3}O{sub 8} certified standards from 10 g {sup 235}U to 3600 g {sup 235}U. The shufflers are used to assay a wide variety of material types for their {sup 235}U contents. When the items differ greatly in chemical composition or shape from the U{sub 3}O{sub 8} standards a bias is introduced because the calibration is not appropriate. Recently a new tool has been created to calculate shuffler count rates accurately, and this has been applied to generate bias correction factors. The tool has also been used to verify the masses and count rates of some uncertified U{sub 3}O{sub 8} standards up to 8.0 kg of {sup 235}U which were used to provisionally extend the calibration beyond the 3.6 kg of {sup 235}U mass when a special need arose. Metallic uranium has significantly different neutronic properties from the U{sub 3}O{sub 8} standards and measured count rates from metals are biased low when the U{sub 3}O{sub 8} calibration is applied. The application of the calculational tool to generate bias corrrections for assorted metals will be described. The accuracy of the calculational tool was verified using highly enriched metal disk standards that could be stacked to form cylinders or put into spread arrays.

  20. Glass dissolution rate measurement and calculation revisited

    NASA Astrophysics Data System (ADS)

    Fournier, Maxime; Ull, Aurélien; Nicoleau, Elodie; Inagaki, Yaohiro; Odorico, Michaël; Frugier, Pierre; Gin, Stéphane

    2016-08-01

    Aqueous dissolution rate measurements of nuclear glasses are a key step in the long-term behavior study of such waste forms. These rates are routinely normalized to the glass surface area in contact with solution, and experiments are very often carried out using crushed materials. Various methods have been implemented to determine the surface area of such glass powders, leading to differing values, with the notion of the reactive surface area of crushed glass remaining vague. In this study, around forty initial dissolution rate measurements were conducted following static and flow rate (SPFT, MCFT) measurement protocols at 90 °C, pH 10. The international reference glass (ISG), in the forms of powders with different particle sizes and polished monoliths, and soda-lime glass beads were examined. Although crushed glass grains clearly cannot be assimilated with spheres, it is when using the samples geometric surface (Sgeo) that the rates measured on powders are closest to those found for monoliths. Overestimation of the reactive surface when using the BET model (SBET) may be due to small physical features at the atomic scale-contributing to BET surface area but not to AFM surface area. Such features are very small compared with the thickness of water ingress in glass (a few hundred nanometers) and should not be considered in rate calculations. With a SBET/Sgeo ratio of 2.5 ± 0.2 for ISG powders, it is shown here that rates measured on powders and normalized to Sgeo should be divided by 1.3 and rates normalized to SBET should be multiplied by 1.9 in order to be compared with rates measured on a monolith. The use of glass beads indicates that the geometric surface gives a good estimation of glass reactive surface if sample geometry can be precisely described. Although data clearly shows the repeatability of measurements, results must be given with a high uncertainty of approximately ±25%.

  1. Biased Brownian dynamics for rate constant calculation.

    PubMed

    Zou, G; Skeel, R D; Subramaniam, S

    2000-08-01

    An enhanced sampling method-biased Brownian dynamics-is developed for the calculation of diffusion-limited biomolecular association reaction rates with high energy or entropy barriers. Biased Brownian dynamics introduces a biasing force in addition to the electrostatic force between the reactants, and it associates a probability weight with each trajectory. A simulation loses weight when movement is along the biasing force and gains weight when movement is against the biasing force. The sampling of trajectories is then biased, but the sampling is unbiased when the trajectory outcomes are multiplied by their weights. With a suitable choice of the biasing force, more reacted trajectories are sampled. As a consequence, the variance of the estimate is reduced. In our test case, biased Brownian dynamics gives a sevenfold improvement in central processing unit (CPU) time with the choice of a simple centripetal biasing force.

  2. Biased Brownian dynamics for rate constant calculation.

    PubMed

    Zou, G; Skeel, R D; Subramaniam, S

    2000-08-01

    An enhanced sampling method-biased Brownian dynamics-is developed for the calculation of diffusion-limited biomolecular association reaction rates with high energy or entropy barriers. Biased Brownian dynamics introduces a biasing force in addition to the electrostatic force between the reactants, and it associates a probability weight with each trajectory. A simulation loses weight when movement is along the biasing force and gains weight when movement is against the biasing force. The sampling of trajectories is then biased, but the sampling is unbiased when the trajectory outcomes are multiplied by their weights. With a suitable choice of the biasing force, more reacted trajectories are sampled. As a consequence, the variance of the estimate is reduced. In our test case, biased Brownian dynamics gives a sevenfold improvement in central processing unit (CPU) time with the choice of a simple centripetal biasing force. PMID:10919998

  3. Technique for atmospheric rate chemistry calculations. [of SST exhaust

    NASA Technical Reports Server (NTRS)

    Matloff, G. L.

    1976-01-01

    The possibility that predictions of atmospheric photochemistry/transport models are sensitive to uncertainties in reaction rates and other inputs stresses the need for rapid numerical integration schemes in rate photochemistry problems. Reducing the computational burden has a major merit in facilitating sensitivity studies to assess the effect of uncertainties on predicted ozone diminutions from NOx (NO + NO2) in the exhaust plume of SST engines. The paper discusses the validity of an algorithmic approach to integration of rate chemistry problems in combustion, developed by Rubel and Baronti for an approximate calculation of the production rate of the i-th chemical species involved. An analysis of two projected SST engines confirms the validity of the proposed algorithm. Because of the relative arithmetical simplicity, it may be easier to treat diffusion rate chemistry calculations using the Rubel and Baronti approximation than would be possible by other approaches.

  4. Pre- and Post-equinox ROSINA production rates calculated using a realistic empirical coma model derived from AMPS-DSMC simulations of comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Hansen, Kenneth; Altwegg, Kathrin; Berthelier, Jean-Jacques; Bieler, Andre; Calmonte, Ursina; Combi, Michael; De Keyser, Johan; Fiethe, Björn; Fougere, Nicolas; Fuselier, Stephen; Gombosi, Tamas; Hässig, Myrtha; Huang, Zhenguang; Le Roy, Lena; Rubin, Martin; Tenishev, Valeriy; Toth, Gabor; Tzou, Chia-Yu

    2016-04-01

    We have previously used results from the AMPS DSMC (Adaptive Mesh Particle Simulator Direct Simulation Monte Carlo) model to create an empirical model of the near comet coma (<400 km) of comet 67P for the pre-equinox orbit of comet 67P/Churyumov-Gerasimenko. In this work we extend the empirical model to the post-equinox, post-perihelion time period. In addition, we extend the coma model to significantly further from the comet (~100,000-1,000,000 km). The empirical model characterizes the neutral coma in a comet centered, sun fixed reference frame as a function of heliocentric distance, radial distance from the comet, local time and declination. Furthermore, we have generalized the model beyond application to 67P by replacing the heliocentric distance parameterizations and mapping them to production rates. Using this method, the model become significantly more general and can be applied to any comet. The model is a significant improvement over simpler empirical models, such as the Haser model. For 67P, the DSMC results are, of course, a more accurate representation of the coma at any given time, but the advantage of a mean state, empirical model is the ease and speed of use. One application of the empirical model is to de-trend the spacecraft motion from the ROSINA COPS and DFMS data (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Comet Pressure Sensor, Double Focusing Mass Spectrometer). The ROSINA instrument measures the neutral coma density at a single point and the measured value is influenced by the location of the spacecraft relative to the comet and the comet-sun line. Using the empirical coma model we can correct for the position of the spacecraft and compute a total production rate based on the single point measurement. In this presentation we will present the coma production rate as a function of heliocentric distance both pre- and post-equinox and perihelion.

  5. Quantum mechanical calculation of Rydberg–Rydberg autoionization rates

    NASA Astrophysics Data System (ADS)

    Kiffner, Martin; Ceresoli, Davide; Li, Wenhui; Jaksch, Dieter

    2016-10-01

    We present quantum mechanical calculations of autoionization rates for two rubidium Rydberg atoms with weakly overlapping electron clouds. We neglect exchange effects and consider tensor products of independent atom states forming an approximate basis of the two-electron state space. We consider large sets of two-atom states with randomly chosen quantum numbers and find that the charge overlap between the two Rydberg electrons allows one to characterise the magnitude of the autoionization rates. If the electron clouds overlap by more than one percent, the autoionization rates increase approximately exponentially with the charge overlap. This finding is independent of the energy of the initial state.

  6. Calculating Graduation Rates: We Can Do Better

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2009-01-01

    The statistic of choice to prove that U.S. schools are failing has changed over time. First, it was test scores that meant they could not keep up with Japan. More recently it has become graduation rate. Often accompanying the graduation rate in the failure litany is the drop-out rate. NCLB puts additional pressure on dropout counts because it…

  7. NPP ATMS Snowfall Rate Product

    NASA Technical Reports Server (NTRS)

    Meng, Huan; Ferraro, Ralph; Kongoli, Cezar; Wang, Nai-Yu; Dong, Jun; Zavodsky, Bradley; Yan, Banghua

    2015-01-01

    Passive microwave measurements at certain high frequencies are sensitive to the scattering effect of snow particles and can be utilized to retrieve snowfall properties. Some of the microwave sensors with snowfall sensitive channels are Advanced Microwave Sounding Unit (AMSU), Microwave Humidity Sounder (MHS) and Advance Technology Microwave Sounder (ATMS). ATMS is the follow-on sensor to AMSU and MHS. Currently, an AMSU and MHS based land snowfall rate (SFR) product is running operationally at NOAA/NESDIS. Based on the AMSU/MHS SFR, an ATMS SFR algorithm has been developed recently. The algorithm performs retrieval in three steps: snowfall detection, retrieval of cloud properties, and estimation of snow particle terminal velocity and snowfall rate. The snowfall detection component utilizes principal component analysis and a logistic regression model. The model employs a combination of temperature and water vapor sounding channels to detect the scattering signal from falling snow and derive the probability of snowfall (Kongoli et al., 2015). In addition, a set of NWP model based filters is also employed to improve the accuracy of snowfall detection. Cloud properties are retrieved using an inversion method with an iteration algorithm and a two-stream radiative transfer model (Yan et al., 2008). A method developed by Heymsfield and Westbrook (2010) is adopted to calculate snow particle terminal velocity. Finally, snowfall rate is computed by numerically solving a complex integral. NCEP CMORPH analysis has shown that integration of ATMS SFR has improved the performance of CMORPH-Snow. The ATMS SFR product is also being assessed at several NWS Weather Forecast Offices for its usefulness in weather forecast.

  8. Simplified methods for calculating photodissociation rates

    NASA Technical Reports Server (NTRS)

    Shimazaki, T.; Ogawa, T.; Farrell, B. C.

    1977-01-01

    Simplified methods for calculating the transmission of solar UV radiation and the dissociation coefficients of various molecules are compared. A significant difference sometimes appears in calculations of the individual band, but the total transmission and the total dissociation coefficients integrated over the entire SR (solar radiation) band region agree well between the methods. The ambiguities in the solar flux data affect the calculated dissociation coefficients more strongly than does the method. A simpler method is developed for the purpose of reducing the computation time and computer memory size necessary for storing coefficients of the equations. The new method can reduce the computation time by a factor of more than 3 and the memory size by a factor of more than 50 compared with the Hudson-Mahle method, and yet the result agrees within 10 percent (in most cases much less) with the original Hudson-Mahle results, except for H2O and CO2. A revised method is necessary for these two molecules, whose absorption cross sections change very rapidly over the SR band spectral range.

  9. Calculating lunar retreat rates using tidal rhythmites

    USGS Publications Warehouse

    Kvale, E.P.; Johnson, H.W.; Sonett, C.P.; Archer, A.W.; Zawistoski, A.N.N.

    1999-01-01

    Tidal rhythmites are small-scale sedimenta??r}- structures that can preserve a hierarchy of astronomically induced tidal periods. They can also preserve a record of periodic nontidal sedimentation. If properly interpreted and understood, tidal rhjthmites can be an important component of paleoastronomy and can be used to extract information on ancient lunar orbital dynamics including changes in Earth-Moon distance through geologic time. Herein we present techniques that can be used to calculate ancient Earth-Moon distances. Each of these techniques, when used on a modern high-tide data set, results in calculated estimates of lunar orbital periods and an EarthMoon distance that fall well within 1 percent of the actual values. Comparisons to results from modern tidal data indicate that ancient tidal rhythmite data as short as 4 months can provide suitable estimates of lunar orbital periods if these tidal records are complete. An understanding of basic tidal theory allows for the evaluation of completeness of the ancient tidal record as derived from an analysis of tidal rhythmites. Utilizing the techniques presented herein, it appears from the rock record that lunar orbital retreat slowed sometime during the midPaleozoic. Copyright ??1999, SEPM (Society for Sedimentary Geology).

  10. 39 CFR 3010.23 - Calculation of percentage change in rates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Calculation of percentage change in rates. 3010.23... change in rates. Link to an amendment published at 79 FR 33833, June 12, 2014. (a) In this section, the... each class of mail and product within the class, the percentage change in rates is calculated in...

  11. 40 CFR 1036.530 - Calculating greenhouse gas emission rates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Calculating greenhouse gas emission... Procedures § 1036.530 Calculating greenhouse gas emission rates. This section describes how to calculate... applicable duty cycle as specified in 40 CFR 1065.650. Do not apply infrequent regeneration...

  12. Updates to In-Line Calculation of Photolysis Rates

    EPA Science Inventory

    How photolysis rates are calculated affects ozone and aerosol concentrations predicted by the CMAQ model and the model?s run-time. The standard configuration of CMAQ uses the inline option that calculates photolysis rates by solving the radiative transfer equation for the needed ...

  13. Shielding calculations for a production target for secondary beams

    SciTech Connect

    Rehm, K.E.; Back, B.B.; Jiang, C.L.

    1995-08-01

    In order to estimate the amount of shielding required for a radioactive beam facility dose rate were performed. The calculations for production targets with different geometries were performed. The calculations were performed with the MSU shielding code assuming a 500-p{mu}A 200-MeV deuteron beam stopped in a thick Al target. The target and the ion-optical elements for beam extraction are located in a 2 m{sup 3} large volume at the center of the production cell. These dose rate calculations show that with a combination of Fe and concrete it is possible to reduce the dose rate expected at the surface of a 7-m-wide cube housing the production target to less than 2 mrem/hr.

  14. Calculates Neutron Production in Canisters of High-level Waste

    1993-01-15

    ALPHN calculates the (alpha,n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the (alpha,n) neutron production of each actinide in neutrons per second and the total for the canister. The (alpha,n) neutron production rates are source terms only; that is, they are production rates within the glass andmore » do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister.« less

  15. Dose Rate Calculations for Rotary Mode Core Sampling Exhauster

    SciTech Connect

    FOUST, D.J.

    2000-10-26

    This document provides the calculated estimated dose rates for three external locations on the Rotary Mode Core Sampling (RMCS) exhauster HEPA filter housing, per the request of Characterization Field Engineering.

  16. Computer Calculation of First-Order Rate Constants

    ERIC Educational Resources Information Center

    Williams, Robert C.; Taylor, James W.

    1970-01-01

    Discusses the computer program used to calculate first-order rate constants. Discussion includes data preparation, weighting options, comparison techniques, infinity point adjustment, least-square fit, Guggenheim calculation, and printed outputs. Exemplifies the utility of the computer program by two experiments: (1) the thermal decomposition of…

  17. Experiences with leak rate calculations methods for LBB application

    SciTech Connect

    Grebner, H.; Kastner, W.; Hoefler, A.; Maussner, G.

    1997-04-01

    In this paper, three leak rate computer programs for the application of leak before break analysis are described and compared. The programs are compared to each other and to results of an HDR Reactor experiment and two real crack cases. The programs analyzed are PIPELEAK, FLORA, and PICEP. Generally, the different leak rate models are in agreement. To obtain reasonable agreement between measured and calculated leak rates, it was necessary to also use data from detailed crack investigations.

  18. Calculation of rates for enzyme and microbial kinetics via a spline technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In biocatalysis research, determination of enzyme kinetics, microbial growth rates, substrate utilization rates, and product accumulation rates sometime require derivatives to be calculated with a method that can be duplicated and yields consistent results. In this paper, several methods that have ...

  19. Benchmark calculations of thermal reaction rates. I - Quantal scattering theory

    NASA Technical Reports Server (NTRS)

    Chatfield, David C.; Truhlar, Donald G.; Schwenke, David W.

    1991-01-01

    The thermal rate coefficient for the prototype reaction H + H2 yields H2 + H with zero total angular momentum is calculated by summing, averaging, and numerically integrating state-to-state reaction probabilities calculated by time-independent quantum-mechanical scattering theory. The results are very carefully converged with respect to all numerical parameters in order to provide high-precision benchmark results for confirming the accuracy of new methods and testing their efficiency.

  20. PX and PXT: New Methods for Calculating Shoreline Change Rates

    NASA Astrophysics Data System (ADS)

    Genz, A. S.; Frazer, L. N.; Fletcher, C. H.; Romine, B. M.; Barbee, M. M.; Lim, S.; Dyer, M.

    2007-12-01

    It is imperative that coastal erosion studies produce valid erosion rates and erosion hazard predictions to aid in the development of public policy and protect coastal resources. Currently, the Single-Transect method is the most common shoreline change model, which calculates a rate at each shore-normal transect without regard to influences of data from adjacent transects along a beach. Improving on Single-Transect, the University of Hawaii Coastal Geology Group has developed the PX (Polynomial in distance X) and PXT (Polynomial in distance X and Time) shoreline change rate calculation methods, which model all the shoreline positions within a beach simultaneously using polynomial techniques. PX is a special case of PXT that models shoreline change rates spatially along a beach. PXT not only models the shoreline change spatially, but it lets the rate change with time (acceleration). This is an important advance, as beaches may not erode or accrete at a constant (linear) rate. A linear sum of basis functions characterizes the shoreline change rate for both PX and PXT. These methods are an improvement on previous methods as they produce more meaningful, i.e., statistically significant rates and erosion hazard predictions. To date, PX and PXT improve the significance in the rate by 25% on Maui. We use an information criterion (gMDL) to (1) identify the number of coefficients of the basis functions that are needed to describe shoreline change in PX and PXT, and (2) compare different methods to determine which method best describes shoreline change. We present an overview of the PX and PXT methods and results from a shoreline change study of the beaches of southeast Oahu, Hawaii, utilizing these rate calculation methods.

  1. Subdaily evapotranspiration rate calculation from streamflow summer diel signal

    NASA Astrophysics Data System (ADS)

    Gribovszki, Z.; Kalicz, P.; Szilágyi, J.

    2009-04-01

    Diel signal of hydrological variables (e.g., shallow groundwater level or streamflow rate) are rarely investigated in the hydrologic literature although these short-term fluctuations may incorporate useful information for the characterization of hydro-ecological systems. Riparian vegetation (especially forest) typically has a great influence on groundwater level and groundwater-sustained baseflow, therefore calculation of the correct evapotranspiration rates is very important for natural protection tasks and water resources management. Recently a new technique was developed by us to calculate daily or even subdaily evapotranspiration rates from groundwater-level measurements, and that method now is modified to estimate evapotranspiration rates from the baseflow diel signal only. The method was successfully tested with hydro-meteorological data from the Hidegvíz Valley experimental catchment in the Sopron Hills at the western border of Hungary. The evapotranspiration rates calculated from the groundwater signal only, are typically (a magnitude) higher than those obtained with an already existing method. With the application of our new technique exploiting the baseflow diel signal of the stream, evapotranspiration rates, very similar to those gained from groundwater level readings and the Penman-Monteith equation, can be obtained. Keywords: baseflow diel signal, evapotranspiration, riparian zone

  2. 42 CFR 413.312 - Methodology for calculating rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... prospectively determined payment rates, CMS uses: (i) The SNF cost data that were used to develop the applicable... recent projections of increases in the costs from the SNF market basket index. (2) In the annual schedule...) Calculation of per diem rate—(1) Routine operating component of rate—(i) Adjusting cost report data. The...

  3. 42 CFR 413.312 - Methodology for calculating rates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... prospectively determined payment rates, CMS uses: (i) The SNF cost data that were used to develop the applicable... recent projections of increases in the costs from the SNF market basket index. (2) In the annual schedule...) Calculation of per diem rate—(1) Routine operating component of rate—(i) Adjusting cost report data. The...

  4. 42 CFR 413.312 - Methodology for calculating rates.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... prospectively determined payment rates, CMS uses: (i) The SNF cost data that were used to develop the applicable... recent projections of increases in the costs from the SNF market basket index. (2) In the annual schedule...) Calculation of per diem rate—(1) Routine operating component of rate—(i) Adjusting cost report data. The...

  5. 42 CFR 413.312 - Methodology for calculating rates.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... prospectively determined payment rates, CMS uses: (i) The SNF cost data that were used to develop the applicable... recent projections of increases in the costs from the SNF market basket index. (2) In the annual schedule...) Calculation of per diem rate—(1) Routine operating component of rate—(i) Adjusting cost report data. The...

  6. 42 CFR 413.312 - Methodology for calculating rates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... prospectively determined payment rates, CMS uses: (i) The SNF cost data that were used to develop the applicable... recent projections of increases in the costs from the SNF market basket index. (2) In the annual schedule...) Calculation of per diem rate—(1) Routine operating component of rate—(i) Adjusting cost report data. The...

  7. Calculations of rates for direct detection of neutralino dark matter

    SciTech Connect

    Griest, K.

    1988-08-08

    The detection rates in cryogenic detectors of neutralinos, the most well motivated supersymmetric dark-matter candidate, are calculated. These rates can differ greatly from the special cases of pure photoinos and pure Higgsinos which are usually considered. In addition, a new term is found in the elastic-scattering cross section proportional to the Z-ino component which is ''spin independent,'' even for these Majorana particles. As a result, substantial detection rates exist for previously disfavored, mostly spinless materials such as germanium and mercury.

  8. Calculations of rates for direct detection of neutralino dark matter

    NASA Technical Reports Server (NTRS)

    Griest, Kim

    1988-01-01

    The detection rates in cryogenic detectors of neutralinos, the most well motivated supersymmetric dark-matter candidate, are calculated. These rates can differ greatly from the special case of pure photinos and pure Higgsinos which are usually considered. In addition, a new term is found in the elastic-scattering cross section proportional to the Z-ino component which is 'spin independent', even for these Majorana particles. As a result, substantial detection rates exist for previously disfavored, mostly spinless materials such as germanium and mercury.

  9. Calculated emission rates for barium releases in space

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.

    1989-01-01

    The optical emissions from barium releases in space are caused by resonance and fluorescent scattering of sunlight. Emission rates for the dominant ion and neutral lines are calculated assuming the release to be optically thin and the barium to be in radiative equilibrium with the solar radiation. The solar spectrum has deep Fraunhofer absorption lines at the primary barium ion resonances. A velocity component toward or away from the sun will Doppler shift the emission lines relative to the absorption lines and the emission rates will increase many-fold over the rest value. The Doppler brightening is important in shaped charge or satellite releases where the barium is injected at high velocities. Emission rates as a function of velocity are calculated for the 4554, 4934, 5854, 6142 and 6497 A ion emission lines and the dominant neutral line at 5535 A. Results are presented for injection parallel to the ambient magnetic field, B, and for injection at an angle to B.

  10. Empirical rate equation model and rate calculations of hydrogen generation for Hanford tank waste

    SciTech Connect

    HU, T.A.

    1999-07-13

    Empirical rate equations are derived to estimate hydrogen generation based on chemical reactions, radiolysis of water and organic compounds, and corrosion processes. A comparison of the generation rates observed in the field with the rates calculated for twenty eight tanks shows agreement with in a factor of two to three.

  11. Cholesteatoma in children, predictors and calculation of recurrence rates.

    PubMed

    Stangerup, S E; Drozdziewicz, D; Tos, M

    1999-10-01

    The aim of the study was to evaluate the long-term recurrence rate after surgery for acquired cholesteatoma in children, to search for predictors of recurrency and to analyse the impact of the applied statistical method on the outcome of the results. During a 15-year period, 114 children underwent first-time surgery for acquired cholesteatoma. The patients were re-evaluated with a median observation time of 5.8 years, range 1-16 years. Recurrence of cholesteatoma developed in 27 ears. The cumulated total recurrence rate was 24% using standard incidence rate calculation, applying Kaplan-Meier survival analysis the recurrence rate was 33%. Recurrent disease occurred significantly more frequent in children < 8 years, with negative preoperative Valsalva, ossicular resorption and with large cholesteatomas. In conclusion, young children with poor Eustachian tube function, large cholesteatoma and erosion of the ossicular chain, are at special risk of recurrence and should be observed several years after surgery. PMID:10577779

  12. Semiclassical Calculation of Reaction Rate Constants for Homolytical Dissociations

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.

    2002-01-01

    There is growing interest in extending organometallic chemical vapor deposition (OMCVD) to III-V materials that exhibit large thermal decomposition at their optimum growth temperature, such as indium nitride. The group III nitrides are candidate materials for light-emitting diodes and semiconductor lasers operating into the blue and ultraviolet regions. To overcome decomposition of the deposited compound, the reaction must be conducted at high pressures, which causes problems of uniformity. Microgravity may provide the venue for maintaining conditions of laminar flow under high pressure. Since the selection of optimized parameters becomes crucial when performing experiments in microgravity, efforts are presently geared to the development of computational OMCVD models that will couple the reactor fluid dynamics with its chemical kinetics. In the present study, we developed a method to calculate reaction rate constants for the homolytic dissociation of III-V compounds for modeling OMCVD. The method is validated by comparing calculations with experimental reaction rate constants.

  13. Calculating the annihilation rate of weakly interacting massive particles.

    PubMed

    Baumgart, Matthew; Rothstein, Ira Z; Vaidya, Varun

    2015-05-29

    We develop a formalism that allows one to systematically calculate the weakly interacting massive particle (WIMP) annihilation rate into gamma rays whose energy far exceeds the weak scale. A factorization theorem is presented which separates the radiative corrections stemming from initial-state potential interactions from loops involving the final state. This separation allows us to go beyond the fixed order calculation, which is polluted by large infrared logarithms. For the case of Majorana WIMPs transforming in the adjoint representation of SU(2), we present the result for the resummed rate at leading double-log accuracy in terms of two initial-state partial-wave matrix elements and one hard matching coefficient. For a given model, one may calculate the cross section by finding the tree level matching coefficient and determining the value of a local four-fermion operator. The effects of resummation can be as large as 100% for a 20 TeV WIMP. However, for lighter WIMP masses relevant for the thermal relic scenario, leading-log resummation modifies the Sudakov factors only at the 10% level. Furthermore, given comparably sized Sommerfeld factors, the total effect of radiative corrections on the semi-inclusive photon annihilation rate is found to be percent level. The generalization of the formalism to other types of WIMPs is discussed.

  14. Divided Saddle Theory: A New Idea for Rate Constant Calculation.

    PubMed

    Daru, János; Stirling, András

    2014-03-11

    We present a theory of rare events and derive an algorithm to obtain rates from postprocessing the numerical data of a free energy calculation and the corresponding committor analysis. The formalism is based on the division of the saddle region of the free energy profile of the rare event into two adjacent segments called saddle domains. The method is built on sampling the dynamics within these regions: auxiliary rate constants are defined for the saddle domains and the absolute forward and backward rates are obtained by proper reweighting. We call our approach divided saddle theory (DST). An important advantage of our approach is that it requires only standard computational techniques which are available in most molecular dynamics codes. We demonstrate the potential of DST numerically on two examples: rearrangement of alanine-dipeptide (CH3CO-Ala-NHCH3) conformers and the intramolecular Cope reaction of the fluxional barbaralane molecule.

  15. Photolysis Rate Coefficient Calculations in Support of SOLVE II

    NASA Technical Reports Server (NTRS)

    Swartz, William H.

    2005-01-01

    A quantitative understanding of photolysis rate coefficients (or "j-values") is essential to determining the photochemical reaction rates that define ozone loss and other crucial processes in the atmosphere. j-Values can be calculated with radiative transfer models, derived from actinic flux observations, or inferred from trace gas measurements. The primary objective of the present effort was the accurate calculation of j-values in the Arctic twilight along NASA DC-8 flight tracks during the second SAGE III Ozone Loss and Validation Experiment (SOLVE II), based in Kiruna, Sweden (68 degrees N, 20 degrees E) during January-February 2003. The JHU/APL radiative transfer model was utilized to produce a large suite of j-values for photolysis processes (over 70 reactions) relevant to the upper troposphere and lower stratosphere. The calculations take into account the actual changes in ozone abundance and apparent albedo of clouds and the Earth surface along the aircraft flight tracks as observed by in situ and remote sensing platforms (e.g., EP-TOMS). A secondary objective was to analyze solar irradiance data from NCAR s Direct beam Irradiance Atmospheric Spectrometer (DIAS) on-board the NASA DC-8 and to start the development of a flexible, multi-species spectral fitting technique for the independent retrieval of O3,O2.02, and aerosol optical properties.

  16. Calculation of relaxation rates from microscopic equations of motion.

    PubMed

    Haydock, R; Nex, C M; Simons, B D

    1999-05-01

    For classical systems with anharmonic forces, Newton's equations for particle trajectories are nonlinear, while Liouville's equation for the evolution of functions of position and momentum is linear and is solved by constructing a basis of functions in which the Liouvillian is a tridiagonal matrix, which is then diagonalized. For systems that are chaotic in the sense that neighboring trajectories diverge exponentially, the initial conditions determine the solution to Liouville's equation for short times; but for long times, the solutions decay exponentially at rates independent of the initial conditions. These are the relaxation rates of irreversible processes, and they arise in these calculations as the imaginary parts of the frequencies where there are singularities in the analytic continuations of solutions to Liouville's equation. These rates are calculated for two examples: the inverted oscillator, which can be solved both analytically and numerically, and a charged particle in a periodic magnetic field, which can only be solved numerically. In these systems, dissipation arises from traveling-wave solutions to Liouville's equation that couple low and high wave-number modes allowing energy to flow from disturbances that are coherent over large scales to disturbances on ever smaller scales finally becoming incoherent over microscopic scales. These results suggest that dissipation in large scale motion of the system is a consequence of chaos in the small scale motion.

  17. User's guide to SERICPAC: A computer program for calculating electric-utility avoided costs rates

    SciTech Connect

    Wirtshafter, R.; Abrash, M.; Koved, M.; Feldman, S.

    1982-05-01

    SERICPAC is a computer program developed to calculate average avoided cost rates for decentralized power producers and cogenerators that sell electricity to electric utilities. SERICPAC works in tandem with SERICOST, a program to calculate avoided costs, and determines the appropriate rates for buying and selling of electricity from electric utilities to qualifying facilities (QF) as stipulated under Section 210 of PURA. SERICPAC contains simulation models for eight technologies including wind, hydro, biogas, and cogeneration. The simulations are converted in a diversified utility production which can be either gross production or net production, which accounts for an internal electricity usage by the QF. The program allows for adjustments to the production to be made for scheduled and forced outages. The final output of the model is a technology-specific average annual rate. The report contains a description of the technologies and the simulations as well as complete user's guide to SERICPAC.

  18. Code System to Calculate Reactor Coolant System Leak Rate.

    1999-10-19

    Version 00 RCSLK9 was developed to analyze the leak tightness of the primary coolant system for any pressurized water reactor (PWR). From given system conditions, water levels in tanks, and certain system design parameters, RCSLK9 calculates the loss of water from the reactor coolant system (RCS) and the increase of water in the leakage collection system during an arbitrary time interval. The program determines the system leak rates and displays or prints a report ofmore » the results. During the initial application to a specific reactor, RCSLK9 creates a file of system parameters and saves it for future use.« less

  19. Calculation of vaporization rates assuming various rate determining steps: Application to the resistojet

    NASA Technical Reports Server (NTRS)

    May, C. E.

    1984-01-01

    The various steps that could control the vaporization rate of a material are discussed. These steps include the actual vaporization, flow rate of matrix gas, chemical reaction, gas diffusion, and solid state diffusion. The applicable equations have been collected from diverse appropriate sources, and their use is explained. Rate equations are derived for conditions where more than one step is rate controlling. Calculations are made for two model materials: rhenium which vaporizes congruently, and tantalum carbide which vaporizes incongruently. The case of vaporization under thermal gradient conditions is also treated. The existence of a thermal gradient in the resistojet means that the vaporization rate of a material may be only one thousandth of that predicted under isothermal conditions. Calculations show that rhenium might have a 100,000 hr lifetime at temperature in a 2500 C resistojet. Tantalum carbide would have a life of only 660 sec under similar conditions.

  20. Thermodynamic and kinetic consistency of calculated binary nucleation rates

    SciTech Connect

    Wilemski, G.; Wyslouzil, B.E.

    1996-04-02

    To establish the accuracy and applicability of analytical expressions for the steady state rate of binary nucleation, we numerically solved the birth-death equations for the vapor-to-liquid transition. These calculations were performed using rate coefficients that are consistent with the principle of detailed balance and a new self-consistent form of the equilibrium distribution function for binary cluster concentrations. We found that the customary saddle point and growth path approximations are almost always valid and can fail only if the nucleating solution phase is significantly nonideal. For example, problems can arise when the vapor composition puts the system on the verge of partial liquid phase miscibility. When this occurs for comparable monomer impingement rates, nucleation still occurs through the saddle point, but the usual quadratic expansion for the cluster free energy is inadequate. When the two impingement rates differ significantly, however, the major particle flux may bypass the saddle point and cross a low ridge on the free energy surface. The dependence of the saddle point location on the gas phase composition is also important in initiating or terminating ridge crossing nucleation.

  1. PFP vertical calciner shield wall dose rate calculations using MCNP

    SciTech Connect

    Wittekind, W.D.

    1997-08-21

    This report yields a neutron shield wall design for a full time occupancy dose rate of 0.25 mrem/h. ORIGEN2 generated gamma ray spectrum and neutron intensity for plutonium. MCNP modeled the calciner glovebox and room for reflection of neutrons off concrete walls and ceiling. Neutron calculations used MCNP in mode n, p to include neutron capture gammas. Photon calculations used MCNP in mode p for gamma rays. Neutron shield with lower 137.16 cm (4.5 feet) of 12.7 cm (5 inch) thick Lucite{reg_sign} and 0.3175 cm (0.125 inch) stainless steel on both sides, and upper 76.2 cm (2.5 feet) of 10.16 cm (4 inch) thick Lucite{reg_sign} and 1.905 cm (0.75 inch) thick glass on each side gave a total weighted dose rate of 0.23 mrem/h, fulfilling the design goal. Lucite{reg_sign} is considered to be equivalent to Plexiglas{reg_sign} since both are methylmethacrylate polymers.

  2. The CAIRN method: automated, reproducible calculation of catchment-averaged denudation rates from cosmogenic nuclide concentrations

    NASA Astrophysics Data System (ADS)

    Marius Mudd, Simon; Harel, Marie-Alice; Hurst, Martin D.; Grieve, Stuart W. D.; Marrero, Shasta M.

    2016-08-01

    We report a new program for calculating catchment-averaged denudation rates from cosmogenic nuclide concentrations. The method (Catchment-Averaged denudatIon Rates from cosmogenic Nuclides: CAIRN) bundles previously reported production scaling and topographic shielding algorithms. In addition, it calculates production and shielding on a pixel-by-pixel basis. We explore the effect of sampling frequency across both azimuth (Δθ) and altitude (Δϕ) angles for topographic shielding and show that in high relief terrain a relatively high sampling frequency is required, with a good balance achieved between accuracy and computational expense at Δθ = 8° and Δϕ = 5°. CAIRN includes both internal and external uncertainty analysis, and is packaged in freely available software in order to facilitate easily reproducible denudation rate estimates. CAIRN calculates denudation rates but also automates catchment averaging of shielding and production, and thus can be used to provide reproducible input parameters for the CRONUS family of online calculators.

  3. Calculations of bottom quark production at hadron colliders

    SciTech Connect

    Kuebel, D.

    1991-06-29

    This thesis studies Monte Carlo simulations of QCD heavy flavor production processes (p{bar p} {yields} Q({anti Q})X) at hadron colliders. ISAJET bottom quark cross-sections are compared to the O({alpha} {sub s}{sup 3}) perturbative calculation of Nason, Dawson, and Ellis. These Monte Carlo cross-sections are computed from data samples which use different parton distribution functions and physics parameters. Distributions are presented in the heavy quark`s transverse momentum and rapidity. Correlations in rapidity and azimuthal angle are computed for the heavy flavor pair. Theory issues which arise are the behavior of the cross-section at low and high values of transverse momentum and the treatment of double counting problems in the flavor excitation samples. An important result is that ISAJET overestimates bottom quark production cross-sections and K factors. These findings are relevant for estimates of rates and backgrounds of heavy floor events.

  4. Calculations of bottom quark production at hadron colliders

    SciTech Connect

    Kuebel, D.

    1991-06-29

    This thesis studies Monte Carlo simulations of QCD heavy flavor production processes (p{bar p} {yields} Q({anti Q})X) at hadron colliders. ISAJET bottom quark cross-sections are compared to the O({alpha} {sub s}{sup 3}) perturbative calculation of Nason, Dawson, and Ellis. These Monte Carlo cross-sections are computed from data samples which use different parton distribution functions and physics parameters. Distributions are presented in the heavy quark's transverse momentum and rapidity. Correlations in rapidity and azimuthal angle are computed for the heavy flavor pair. Theory issues which arise are the behavior of the cross-section at low and high values of transverse momentum and the treatment of double counting problems in the flavor excitation samples. An important result is that ISAJET overestimates bottom quark production cross-sections and K factors. These findings are relevant for estimates of rates and backgrounds of heavy floor events.

  5. 30 CFR 250.1632 - Production rates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Production rates. 250.1632 Section 250.1632 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632 Production rates. Each...

  6. Examination of the semi-automatic calculation technique of vegetation cover rate by digital camera images.

    NASA Astrophysics Data System (ADS)

    Takemine, S.; Rikimaru, A.; Takahashi, K.

    The rice is one of the staple foods in the world High quality rice production requires periodically collecting rice growth data to control the growth of rice The height of plant the number of stem the color of leaf is well known parameters to indicate rice growth Rice growth diagnosis method based on these parameters is used operationally in Japan although collecting these parameters by field survey needs a lot of labor and time Recently a laborsaving method for rice growth diagnosis is proposed which is based on vegetation cover rate of rice Vegetation cover rate of rice is calculated based on discriminating rice plant areas in a digital camera image which is photographed in nadir direction Discrimination of rice plant areas in the image was done by the automatic binarization processing However in the case of vegetation cover rate calculation method depending on the automatic binarization process there is a possibility to decrease vegetation cover rate against growth of rice In this paper a calculation method of vegetation cover rate was proposed which based on the automatic binarization process and referred to the growth hysteresis information For several images obtained by field survey during rice growing season vegetation cover rate was calculated by the conventional automatic binarization processing and the proposed method respectively And vegetation cover rate of both methods was compared with reference value obtained by visual interpretation As a result of comparison the accuracy of discriminating rice plant areas was increased by the proposed

  7. 20 CFR 10.216 - How is the pay rate for COP calculated?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true How is the pay rate for COP calculated? 10.216... AMENDED Continuation of Pay Calculation of Cop § 10.216 How is the pay rate for COP calculated? The employer shall calculate COP using the period of time and the weekly pay rate. (a) The pay rate for...

  8. 20 CFR 10.216 - How is the pay rate for COP calculated?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true How is the pay rate for COP calculated? 10.216... AMENDED Continuation of Pay Calculation of Cop § 10.216 How is the pay rate for COP calculated? The employer shall calculate COP using the period of time and the weekly pay rate. (a) The pay rate for...

  9. Photolysis Rate Coefficient Calculations in Support of SOLVE Campaign

    NASA Technical Reports Server (NTRS)

    Lloyd, Steven A.; Swartz, William H.

    2001-01-01

    The objectives for this SOLVE project were 3-fold. First, we sought to calculate a complete set of photolysis rate coefficients (j-values) for the campaign along the ER-2 and DC-8 flight tracks. En route to this goal, it would be necessary to develop a comprehensive set of input geophysical conditions (e.g., ozone profiles), derived from various climatological, aircraft, and remotely sensed datasets, in order to model the radiative transfer of the atmosphere accurately. These j-values would then need validation by comparison with flux-derived j-value measurements. The second objective was to analyze chemistry along back trajectories using the NASA/Goddard chemistry trajectory model initialized with measurements of trace atmospheric constituents. This modeling effort would provide insight into the completeness of current measurements and the chemistry of Arctic wintertime ozone loss. Finally, we sought to coordinate stellar occultation measurements of ozone (and thus ozone loss) during SOLVE using the Midcourse Space Experiment(MSX)/Ultraviolet and Visible Imagers and Spectrographic Imagers (UVISI) satellite instrument. Such measurements would determine ozone loss during the Arctic polar night and represent the first significant science application of space-based stellar occultation in the Earth's atmosphere.

  10. Photolysis Rate Coefficient Calculations in Support of SOLVE Campaign

    NASA Technical Reports Server (NTRS)

    Lloyd, Steven A.; Swartz, William H.

    2001-01-01

    The objectives for this SOLVE project were 3-fold. First, we sought to calculate a complete set of photolysis rate coefficients (j-values) for the campaign along the ER-2 and DC-8 flight tracks. En route to this goal, it would be necessary to develop a comprehensive set of input geophysical conditions (e.g., ozone profiles), derived from various climatological, aircraft, and remotely sensed datasets, in order to model the radiative transfer of the atmosphere accurately. These j-values would then need validation by comparison with flux-derived j-value measurements. The second objective was to analyze chemistry along back trajectories using the NASA/Goddard chemistry trajectory model initialized with measurements of trace atmospheric constituents. This modeling effort would provide insight into the completeness of current measurements and the chemistry of Arctic wintertime ozone loss. Finally, we sought to coordinate stellar occultation measurements of ozone (and thus ozone loss) during SOLVE using the MSX/UVISI satellite instrument. Such measurements would determine ozone loss during the Arctic polar night and represent the first significant science application of space-based stellar occultation in the Earth's atmosphere.

  11. Calculation of Reactive-evaporation Rates of Chromia

    SciTech Connect

    Holcomb, G.R.

    2008-04-01

    A methodology is developed to calculate Cr-evaporation rates from Cr2O3 with a flat planar geometry. Variables include temperature, total pressure, gas velocity, and gas composition. The methodology was applied to solid-oxide, fuel cell conditions for metallic interconnects and to advanced-steam turbines conditions. The high velocities and pressures of the advanced steam turbine led to evaporation predictions as high as 5.18 9 10-8 kg/m2/s of CrO2(OH)2(g) at 760 °C and 34.5 MPa. This is equivalent to 0.080 mm per year of solid Cr loss. Chromium evaporation is expected to be an important oxidation mechanism with the types of nickel-base alloys proposed for use above 650 °C in advanced-steam boilers and turbines. It is shown that laboratory experiments, with much lower steam velocities and usually much lower total pressure than found in advanced steam turbines, would best reproduce chromium-evaporation behavior with atmospheres that approach either O2 + H2O or air + H2O with 57% H2O.

  12. A method for calculating the productivity of cable communications networks

    NASA Astrophysics Data System (ADS)

    Shulikin, S. N.; Shulikina, M. S.; Maryin, S. S.; Vinogradova, D. V.; Zavgorodnyaya, M. E.

    2016-04-01

    A probabilistic-mathematical instrument was used to develop a method for calculating the productivity of a cable line. The effect of deviation of factors from data of recording devices was determined when identifying random stream characteristics. The developed method was used to perform predictive calculation of the productivity of the modern cable communication line.

  13. Atmospheric chemistry of CF3CF═CH2 and (Z)-CF3CF═CHF: Cl and NO3 rate coefficients, Cl reaction product yields, and thermochemical calculations.

    PubMed

    Papadimitriou, Vassileios C; Lazarou, Yannis G; Talukdar, Ranajit K; Burkholder, James B

    2011-01-20

    Rate coefficients, k, for the gas-phase reactions of Cl atoms and NO(3) radicals with 2,3,3,3-tetrafluoropropene, CF(3)CF═CH(2) (HFO-1234yf), and 1,2,3,3,3-pentafluoropropene, (Z)-CF(3)CF═CHF (HFO-1225ye), are reported. Cl-atom rate coefficients were measured in the fall-off region as a function of temperature (220-380 K) and pressure (50-630 Torr; N(2), O(2), and synthetic air) using a relative rate method. The measured rate coefficients are well represented by the fall-off parameters k(0)(T) = 6.5 × 10(-28) (T/300)(-6.9) cm(6) molecule(-2) s(-1) and k(∞)(T) = 7.7 × 10(-11) (T/300)(-0.65) cm(3) molecule(-1) s(-1) for CF(3)CF═CH(2) and k(0)(T) = 3 × 10(-27) (T/300)(-6.5) cm(6) molecule(-2) s(-1) and k(∞)(T) = 4.15 × 10(-11) (T/300)(-0.5) cm(3) molecule(-1) s(-1) for (Z)-CF(3)C═CHF with F(c) = 0.6. Reaction product yields were measured in the presence of O(2) to be (98 ± 7)% for CF(3)C(O)F and (61 ± 4)% for HC(O)Cl in the CF(3)CF═CH(2) reaction and (108 ± 8)% for CF(3)C(O)F and (112 ± 8)% for HC(O)F in the (Z)-CF(3)CF═CHF reaction, where the quoted uncertainties are 2σ (95% confidence level) and include estimated systematic errors. NO(3) reaction rate coefficients were determined using absolute and relative rate methods. Absolute measurements yielded upper limits for both reactions between 233 and 353 K, while the relative rate measurements yielded k(3)(295 K) = (2.6 ± 0.25) × 10(-17) cm(3) molecule(-1) s(-1) and k(4)(295 K) = (4.2 ± 0.5) × 10(-18) cm(3) molecule(-1) s(-1) for CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF, respectively. The Cl-atom reaction with CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF leads to decreases in their atmospheric lifetimes and global warming potentials and formation of a chlorine-containing product, HC(O)Cl, for CF(3)CF═CH(2). The NO(3) reaction has been shown to have a negligible impact on the atmospheric lifetimes of CF(3)CF═CH(2) and (Z)-CF(3)CF═CHF. The energetics for the reaction of Cl, NO(3), and OH with CF

  14. 20 CFR 10.216 - How is the pay rate for COP calculated?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false How is the pay rate for COP calculated? 10..., AS AMENDED Continuation of Pay Calculation of Cop § 10.216 How is the pay rate for COP calculated? The employer shall calculate COP using the period of time and the weekly pay rate. (a) The pay...

  15. 20 CFR 10.216 - How is the pay rate for COP calculated?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false How is the pay rate for COP calculated? 10..., AS AMENDED Continuation of Pay Calculation of Cop § 10.216 How is the pay rate for COP calculated? The employer shall calculate COP using the period of time and the weekly pay rate. (a) The pay...

  16. 20 CFR 10.216 - How is the pay rate for COP calculated?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How is the pay rate for COP calculated? 10..., AS AMENDED Continuation of Pay Calculation of Cop § 10.216 How is the pay rate for COP calculated? The employer shall calculate COP using the period of time and the weekly pay rate. (a) The pay...

  17. Code System to Calculate Integral Parameters with Reaction Rates from WIMS Output.

    1994-10-25

    Version 00 REACTION calculates different integral parameters related to neutron reactions on reactor lattices, from reaction rates calculated with WIMSD4 code, and comparisons with experimental values.

  18. Effect of seeding rate on organic production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased demand for organic rice (Oryza sativa L.) has incentivized producer conversion from conventional to organically-managed rice production in the U.S. Little is known on the impacts of seeding rate on organic rice production. A completely randomized factorial design with four replications was...

  19. Production rates of cosmogenic nuclides in stony meteorites

    SciTech Connect

    Divadeenam, M.; Gabriel, T.A.; Lazareth, O.W.; Spergel, M.S.; Ward, T.E.

    1989-01-01

    Monte Carlo calculations of /sup 26/Al and /sup 53/Mn production due to spallation induced by cosmogenic protons in model meteorite composition similar to L Chondrite has yielded predictions which are consistent with the observed decay rates in L Chondrite stony meteorites. The calculated /sup 26/Al production rate (54 dpm/kg) in a 1 m diameter meteorite is within 1/2 S.D. of the mean (49 +- 11 dpm/kg) taken from 100 bulk determinations in L Chondrite samples compiled in Nishiizumi (1987). Similarly calculated average value for /sup 53/Mn (223 dpm/kg) is consistent with one S.D. off the mean in the widely scattered /sup 53/Mn data (362 +- 113 dpm/kg) compiled by Nishiizumi (1987). 9 refs.

  20. 49 CFR 1141.1 - Procedures to calculate interest rates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Prime Rate as published by The Wall Street Journal. The rate levels will be determined as follows: (1... Street Journal in effect on the date the statement is filed accounting for all amounts received under the... by The Wall Street Journal in effect on the day when the unlawful charge is paid. The interest...

  1. 7 CFR 760.811 - Rates and yields; calculating payments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... expected production, as determined by FSA, of the unit. (2) Payments made under this part to a participant... expected production value, as determined by FSA, of the unit. (3) As determined by FSA, additional quality... a loss of quantity on a unit with respect to yield-based crops are determined by multiplying...

  2. Relative crater production rates on planets

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1977-01-01

    The relative numbers of impacts on different planets, estimated from the dynamical histories of planetesimals in specified orbits (Wetherill, 1975), are converted by a described procedure to crater production rates. Conversions are dependent on impact velocity and surface gravity. Crater retention ages can then be derived from the ratio of the crater density to the crater production rate. The data indicate that the terrestrial planets have crater production rates within a factor ten of each other. As an example, for the case of Mars, least-squares fits to crater-count data suggest an average age of 0.3 to 3 billion years for two types of channels. The age of Olympus Mons is discussed, and the effect of Tharsis volcanism on channel formation is considered.

  3. 7 CFR 760.811 - Rates and yields; calculating payments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS INDEMNITY PAYMENT PROGRAMS 2005-2007 Crop Disaster Program § 760... determined according to § 760.817. (b) Payment rates for the 2005, 2006, or 2007 year crop losses will be...

  4. Rate of nova production in the Galaxy

    SciTech Connect

    Liller, W.; Mayer, B.

    1987-07-01

    The ongoing PROBLICOM program in the Southern Hemisphere now makes it possible to derive a reliable value for the overall production rate of Galactic novae. The results, 73 + or - 24/y, indicates that the Galaxy outproduces M 31 by a factor of two or three. It is estimated that the rate of supernova ejecta is one and a half orders of magnitude greater than that of novae in the Galaxy. 15 references.

  5. Polymer reversal rate calculated via locally scaled diffusion map.

    PubMed

    Zheng, Wenwei; Rohrdanz, Mary A; Maggioni, Mauro; Clementi, Cecilia

    2011-04-14

    A recent study on the dynamics of polymer reversal inside a nanopore by Huang and Makarov [J. Chem. Phys. 128, 114903 (2008)] demonstrated that the reaction rate cannot be reproduced by projecting the dynamics onto a single empirical reaction coordinate, a result suggesting the dynamics of this system cannot be correctly described by using a single collective coordinate. To further investigate this possibility we have applied our recently developed multiscale framework, locally scaled diffusion map (LSDMap), to obtain collective reaction coordinates for this system. Using a single diffusion coordinate, we obtain a reversal rate via Kramers expression that is in good agreement with the exact rate obtained from the simulations. Our mathematically rigorous approach accounts for the local heterogeneity of molecular configuration space in constructing a diffusion map, from which collective coordinates emerge. We believe this approach can be applied in general to characterize complex macromolecular dynamics by providing an accurate definition of the collective coordinates associated with processes at different time scales.

  6. Calculating the College-to-University Transfer Rate in Ontario

    ERIC Educational Resources Information Center

    Decock, Henry

    2004-01-01

    Measuring transfer is as varied as it is controversial, particularly in an era of increased accountability and in the case of Ontario Colleges, in a time of flux and change. American Community Colleges have been grappling with the definition of a transfer rate, continuing to fail on reaching a consensus. The importance of an acceptable transfer…

  7. 30 CFR 250.1632 - Production rates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Production rates. 250.1632 Section 250.1632 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632...

  8. 30 CFR 250.1632 - Production rates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Production rates. 250.1632 Section 250.1632 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632...

  9. 30 CFR 250.1632 - Production rates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Production rates. 250.1632 Section 250.1632 Mineral Resources BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632...

  10. Modeling of asteroidal dust production rates

    NASA Technical Reports Server (NTRS)

    Durda, Daniel D.; Dermott, Stanley F.; Gustafson, Bo A. S.

    1992-01-01

    The production rate of dust associated with the prominent Hirayama asteroid families and the background asteroidal population are modeled with the intent of using the families as a calibrator of mainbelt dust production. However, the dust production rates of asteroid families may be highly stochastic; there is probably more than an order of magnitude variation in the total area of dust associated with a family. Over 4.5 x 10(exp 9) years of collisional evolution, the volume (mass) of a family is ground down by an order of magnitude, suggesting a similar loss from the entire mainbelt population. Our collisional models show that the number of meteoroids deliverable to Earth also varies stochastically, but only by a factor of 2 to 3.

  11. Photochemical Production Rates in Western Houston

    SciTech Connect

    Berkowitz, Carl M.; Spicer, C. W.; Doskey, Paul V.

    2004-01-01

    In this paper, we evaluate the instantaneous O3 chemical production rates, NOx (= NO + NO2) loss rates and ozone production efficiency within ozone plumes sampled on the west side of Houston, Texas, during the Texas 2000 Air Quality Study. We emphasize days during which rapid increases associated with plume passage were observed in the 15-minute average ozone mixing ratio, O3. The basis for this work will be observations of key nitrogen species and VOCs collected from the top of a sky scraper on the western edge of the city. These observations are used in a 0-dimensional model to quantify the chemical kinetics within parcels of air associated with ozone levels in excess of 100 ppb. We identify the key VOCs affecting ozone production and assess the relative role of anthropogenic versus biogenic VOCs to local ozone production. We also examine how the daily variations in ozone production and ozone production efficiencies are related to differences in VOC/NOx ratios.

  12. Personal computer program and spreadsheet for calculating the coal mine roof rating (CMRR). Information circular/1994

    SciTech Connect

    Riefenberg, J.; Wuest, W.J.

    1994-01-01

    A family of personal computer programs that calculate the Coal Mine Roof Rating (CMRR) have been developed by the U.S. Bureau of Mines. The CMRR, rock mass classification system, was recently developed by Bureau researchers to provide a link between the qualitative geologists' description of coal mine roof and the quantitive mine engineers' needs for mine design, roof support selection, and hazard detection. The program CMRR, is a user-friendly, interactive program into which raw field data are input, and a CMRR is calculated and output along with two graphic displays. The first graphic display is a plan view map with the roof ratings displayed on a color-coded scale, and the second display shows a stratigraphic section of the bolted roof interval and its resultant roof rating. In addition, a Lotus 1-2-3 worksheet, BOM-CMRR.WK3, has been developed for easy storage of field data. The worksheet also includes macros developed for calculation and storage of the CMRR. Production of summary reports for analysis of site-specific information are readily generated using Lotus. These programs help to facilitate the engineer in utilizing the CMRR in ground control studies.

  13. Calculations on decay rates of various proton emissions

    NASA Astrophysics Data System (ADS)

    Qian, Yibin; Ren, Zhongzhou

    2016-03-01

    Proton radioactivity of neutron-deficient nuclei around the dripline has been systematically studied within the deformed density-dependent model. The crucial proton-nucleus potential is constructed via the single-folding integral of the density distribution of daughter nuclei and the effective M3Y nucleon-nucleon interaction or the proton-proton Coulomb interaction. After the decay width is obtained by the modified two-potential approach, the final decay half-lives can be achieved by involving the spectroscopic factors from the relativistic mean-field (RMF) theory combined with the BCS method. Moreover, a simple formula along with only one adjusted parameter is tentatively proposed to evaluate the half-lives of proton emitters, where the introduction of nuclear deformation is somewhat discussed as well. It is found that the calculated results are in satisfactory agreement with the experimental values and consistent with other theoretical studies, indicating that the present approach can be applied to the case of proton emission. Predictions on half-lives are made for possible proton emitters, which may be useful for future experiments.

  14. Towards a Model for Protein Production Rates

    NASA Astrophysics Data System (ADS)

    Dong, J. J.; Schmittmann, B.; Zia, R. K. P.

    2007-07-01

    In the process of translation, ribosomes read the genetic code on an mRNA and assemble the corresponding polypeptide chain. The ribosomes perform discrete directed motion which is well modeled by a totally asymmetric simple exclusion process (TASEP) with open boundaries. Using Monte Carlo simulations and a simple mean-field theory, we discuss the effect of one or two "bottlenecks" (i.e., slow codons) on the production rate of the final protein. Confirming and extending previous work by Chou and Lakatos, we find that the location and spacing of the slow codons can affect the production rate quite dramatically. In particular, we observe a novel "edge" effect, i.e., an interaction of a single slow codon with the system boundary. We focus in detail on ribosome density profiles and provide a simple explanation for the length scale which controls the range of these interactions.

  15. Calculation of dose conversion factors for thoron decay products.

    PubMed

    Ishikawa, Tetsuo; Tokonami, Shinji; Nemeth, Csaba

    2007-12-01

    The dose conversion factors for short-lived thoron decay products were calculated using a dosimetric approach. The calculations were based on a computer program LUDEP, which implements the ICRP 66 respiratory tract model. The dose per equilibrium equivalent concentration for thoron (EETC) was calculated with respect to (1) equivalent dose to each region of the lung tissues (bronchial, bronchiolar and alveolar), (2) weighted equivalent dose to organs other than lung, and (3) effective dose. The calculations indicated that (1) the most exposed region of the lung tissues was the bronchial for the unattached fraction and the bronchiolar for the attached fraction, (2) the effective dose is dominated by the contribution of lung dose, and (3) the effective dose per EETC was about four times larger than the effective dose per equilibrium equivalent concentration for radon (EERC). The calculated dose conversion factors were applied to the comparative dosimetry for some thoron-enhanced areas where the EERC and EETC have been measured. In the case of a spa in Japan, the dose from thoron decay products was larger than the dose from radon decay products.

  16. Calculation of fusion product angular correlation coefficients for fusion plasmas

    SciTech Connect

    Murphy, T.J.

    1987-08-01

    The angular correlation coefficients for fusion products are calculated in the cases of Maxwellian and beam-target plasmas. Measurement of these coefficients as a localized ion temperature or fast-ion diagnostic is discussed. 8 refs., 7 figs., 1 tab.

  17. Methodology for calculation of carbon balances for biofuel crops production

    NASA Astrophysics Data System (ADS)

    Gerlfand, I.; Hamilton, S. K.; Snapp, S. S.; Robertson, G. P.

    2012-04-01

    Understanding the carbon balance implications for different biofuel crop production systems is important for the development of decision making tools and policies. We present here a detailed methodology for assessing carbon balances in agricultural and natural ecosystems. We use 20 years of data from Long-term Ecological Research (LTER) experiments at the Kellogg Biological Station (KBS), combined with models to produce farm level CO2 balances for different management practices. We compared four grain and one forage systems in the U.S. Midwest: corn (Zea mays) - soybean (Glycine max) - wheat (Triticum aestivum) rotations managed with (1) conventional tillage, (2) no till, (3) low chemical input, and (4) biologically-based (organic) practices; and (5) continuous alfalfa (Medicago sativa). In addition we use an abandoned agricultural field (successionnal ecosystem) as reference system. Measurements include fluxes of N2O and CH4, soil organic carbon change, agricultural yields, and agricultural inputs (e.g. fertilization and farm fuel use). In addition to measurements, we model carbon offsets associated with the use of bioenergy from agriculturally produced crops. Our analysis shows the importance of establishing appropriate system boundaries for carbon balance calculations. We explore how different assumptions regarding production methods and emission factors affect overall conclusions on carbon balances of different agricultural systems. Our results show management practices that have major the most important effects on carbon balances. Overall, agricultural management with conventional tillage was found to be a net CO2 source to the atmosphere, while agricultural management under reduced tillage, low input, or organic management sequestered carbon at rates of 93, -23, -51, and -14 g CO2e m-2 yr-1, respectively for conventionally tilled, no-till, low-input, and organically managed ecosystems. Perennial systems (alfalfa and the successionnal fields) showed net carbon

  18. Predicting the production rates of cosmogenic nuclides in extraterrestrial matter

    SciTech Connect

    Reedy, R.C.

    1987-01-01

    The production rates of nuclides made by the galactic and solar cosmic rays are important in the interpretations of measurements made with lunar samples, meteorites, and cosmic spherules. Production rates of cosmogenic nuclides have been predicted by a variety of methods that are reviewed in this paper, ranging from systematic studies of one or a group of meteorites to purely theoretical calculations. Production rates can vary with the chemical composition and the preatmospheric depth of the sample and with the size and shape of the object. While the production systematics for cosmogenic nuclides are fairly well known, our ability to predict their production rates can be improved, with a corresponding increase in the scientific return. Additional detailed studies of cosmogenic nuclides in extraterrestrial objects are needed, especially for fairly small and very large objects. Nuclides made in simulation experiments and cross sections for many major nuclear reactions should be measured. Such studies are especially needed for the long-lived radionuclides that have only recently become readily measurable by accelerator mass spectrometry. 34 refs., 5 figs.

  19. Calculations on the rate of the ion-molecule reaction between NH3(+) and H2

    NASA Technical Reports Server (NTRS)

    Herbst, Eric; Defrees, D. J.; Talbi, D.; Pauzat, F.; Koch, W.

    1991-01-01

    The rate coefficient for the ion-molecule reaction NH3(+) + H2 yields NH4(+) + H has been calculated as a function of temperature with the use of the statistical phase space approach. The potential surface and reaction complex and transition state parameters used in the calculation have been taken from ab initio quantum chemical calculations. The calculated rate coefficient has been found to mimic the unusual temperature dependence measured in the laboratory, in which the rate coefficient decreases with decreasing temperature until 50-100 K and then increases at still lower temperatures. Quantitative agreement between experimental and theoretical rate coefficients is satisfactory given the uncertainties in the ab initio results and in the dynamics calculations. The rate coefficient for the unusual three-body process NH3(+) + H2 + He yields NH4(+) + H + He has also been calculated as a function of temperature and the result found to agree well with a previous laboratory determination.

  20. ATMS Snowfall Rate Product and Its Applications

    NASA Astrophysics Data System (ADS)

    Meng, H.; Kongoli, C.; Dong, J.; Wang, N. Y.; Ferraro, R. R.; Zavodsky, B.; Banghua Yan, B.

    2015-12-01

    A snowfall rate (SFR) algorithm has been developed for the Advanced Technology Microwave Sounder (ATMS) aboard S-NPP and future JPSS satellites. The product is based on the NOAA/NESDIS operational Microwave Humidity Sounder (MHS) SFR but with several key advancements. The algorithm has benefited from continuous development to improve accuracy and snowfall detection efficiency. The enhancements also expand the applicable temperature range for the algorithm and allow significantly more snowfall to be detected than the operational SFR. Another major improvement is the drastically reduced product latency by using Direct Broadcast (DB) data. The new developments have also been implemented in the MHS SFR to ensure product consistency across satellites. Currently, there are five satellites that carry either ATMS or MHS: S-NPP, NOAA-18/-19 and Metop-A/-B. The combined satellites deliver up to ten SFR estimates a day at any location over land in mid-latitudes. The product provides much needed winter precipitation estimates for applications such as weather forecasting and hydrology. Both ATMS and MHS SFR serve as input to a global precipitation analysis product, the NOAA/NCEP CMORPH-Snow. SFR is the sole satellite-based snowfall estimates in the blended product. In addition, ATMS and MHS SFR was assessed at several NWS Weather Forecast Offices (WFOs) and NESDIS/Satellite Analysis Branch (SAB) for its operational values in winter 2015. This is a joint effort among NASA/SPoRT, NOAA/NESDIS, University of Maryland/CICS, and the WFOs. The feedback from the assessment indicated that SFR provides useful information for snowfall forecast. It is especially valuable for areas with poor radar coverage and ground observations. The feedback also identified some limitations of the product such as inadequate detection of shallow snowfall. The algorithm developers will continue to improve product quality as well as developing SFR for new microwave sensors and over ocean in a project

  1. Using a Calculated Pulse Rate with an Artificial Neural Network to Detect Irregular Interbeats.

    PubMed

    Yeh, Bih-Chyun; Lin, Wen-Piao

    2016-03-01

    Heart rate is an important clinical measure that is often used in pathological diagnosis and prognosis. Valid detection of irregular heartbeats is crucial in the clinical practice. We propose an artificial neural network using the calculated pulse rate to detect irregular interbeats. The proposed system measures the calculated pulse rate to determine an "irregular interbeat on" or "irregular interbeat off" event. If an irregular interbeat is detected, the proposed system produces a danger warning, which is helpful for clinicians. If a non-irregular interbeat is detected, the proposed system displays the calculated pulse rate. We include a flow chart of the proposed software. In an experiment, we measure the calculated pulse rates and achieve an error percentage of < 3% in 20 participants with a wide age range. When we use the calculated pulse rates to detect irregular interbeats, we find such irregular interbeats in eight participants. PMID:26643078

  2. 40 CFR 75.83 - Calculation of Hg mass emissions and heat input rate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Calculation of Hg mass emissions and... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Hg Mass Emission Provisions § 75.83 Calculation of Hg mass emissions and heat input rate. The owner or operator shall calculate Hg mass...

  3. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION & LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    SciTech Connect

    HU, T.A.

    2004-10-27

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The hydrogen generation rate was calculated for 177 tanks using the rate equation model. Flammability calculations based on hydrogen, ammonia, and methane were performed for 177 tanks for various scenarios.

  4. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION AND LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    SciTech Connect

    HU TA

    2009-10-26

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The hydrogen generation rate was calculated for 177 tanks using the rate equation model. Flammability calculations based on hydrogen, ammonia, and methane were performed for 177 tanks for various scenarios.

  5. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION & LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    SciTech Connect

    HU, T.A.

    2005-10-27

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The hydrogen generation rate was calculated for 177 tanks using the rate equation model. Flammability calculations based on hydrogen, ammonia, and methane were performed for 177 tanks for various scenarios.

  6. 7 CFR 760.705 - Payment rates and calculation of payments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Payment rates and calculation of payments. 760.705 Section 760.705 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS INDEMNITY PAYMENT PROGRAMS Crop Assistance Program § 760.705 Payment rates and calculation of...

  7. 7 CFR 760.705 - Payment rates and calculation of payments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Payment rates and calculation of payments. 760.705 Section 760.705 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS INDEMNITY PAYMENT PROGRAMS Crop Assistance Program § 760.705 Payment rates and calculation of...

  8. 7 CFR 760.705 - Payment rates and calculation of payments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Payment rates and calculation of payments. 760.705 Section 760.705 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS INDEMNITY PAYMENT PROGRAMS Crop Assistance Program § 760.705 Payment rates and calculation of...

  9. Analysis of the effects of zonal averaging on reaction rate calculations in two-dimensional atmospheric models

    NASA Technical Reports Server (NTRS)

    Kaye, Jack A.

    1987-01-01

    The usual assumption by which chemical reaction rates are calculated in two-dimensional atmospheric models is by using a product of zonal means of rate coefficients and constituent concentrations rather than the rigorous zonal mean of the corresponding products. This assumption has been tested for the reactions O + NO2 yields NO + O2 and NO + O3 yields NO2 + O2 using mapped limb infrared monitor of the stratosphere data from the Nimbus 7 satellite and found to be quite satisfactory for winter 1979 at 60 deg N in the upper stratosphere. Relative differences between the two-dimensional averaged rate and the more rigorous rate, calculated from the full, longitudinally varying temperatures and mixing ratios, were small (usually below 5 percent) and exceeded 15 percent only during times of strong dynamical activity. At those times or locations where stratospheric circulation is primarily zonal, the two averages agreed to within a few percent.

  10. Production rates of neon xenon isotopes by energetic neutrons

    NASA Technical Reports Server (NTRS)

    Leich, D. A.; Borg, R. J.; Lanier, V. B.

    1986-01-01

    As a first step in an experimental program to study the behavior of noble gases produced in situ in minerals, a suite of minerals and pure chemicals were irradiated with 14.5 MeV neutrons at LLNL's Rotating Target Neutron Source (RTNS-II) and production rates for noble gases were determined. While neutron effects in meteorites and lunar samples are dominated by low-energy neutron capture, more energetic cosmic-ray secondary neutrons can provide significant depth-dependent contributions to production of cosmogenic nuclides through endothermic reactions such as (n,2n), (n,np), (n,d) and (n,alpha). Production rates for nuclides produced by cosmic-ray secondary neutrons are therefore useful in interpreting shielding histories from the relative abundances of cosmogenic nuclides. Absolute production cross sections were calculated from isotope dilution analyses of NaCl, Mg, CsCl, and Ba(NO3)2 samples, assuming purity, stoichiometry, and quantitative noble gas retention and extraction. Relative production cross sections determined from neon isotopic ratios in the mineral samples were also considered in evaluating the neon production cross sections. Results are presented.

  11. 39 CFR 3010.26 - Calculation of unused rate adjustment authority.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... unused rate adjustment authority. Link to an amendment published at 79 FR 33834, June 12, 2014. (a... the second notice is filed and interim unused rate adjustment authority will be calculated for the... months before the second notice is filed. (2) Interim unused rate adjustment authority is equal to...

  12. Factors affecting production rates of cosmogenic nuclides in extraterrestrial matter

    NASA Astrophysics Data System (ADS)

    Reedy, R. C.

    2015-10-01

    Good production rates are needed for cosmic-ray-produced nuclides to interpret their measurements. Rates depend on many factors, especially the pre-atmospheric object's size, the location of the sample in that object (such as near surface or deep inside), and the object's bulk composition. The bulk composition affects rates, especially in objects with very low and very high iron contents. Extraterrestrial materials with high iron contents usually have higher rates for making nuclides made by reactions with energetic particles and lower rates for the capture of thermal neutrons. In small objects and near the surface of objects, the cascade of secondary neutrons is being developed as primary particles are being removed. Deep in large objects, that secondary cascade is fully developed and the fluxes of primary particles are low. Recent work shows that even the shape of an object in space has a small but measureable effect. Work has been done and continues to be done on better understanding those and other factors. More good sets of measurements in meteorites with known exposure geometries in space are needed. With the use of modern Monte Carlo codes for the production and transport of particles, the nature of these effects have been and is being studied. Work needs to be done to improve the results of these calculations, especially the cross sections for making spallogenic nuclides.

  13. The Multi-Step CADIS method for shutdown dose rate calculations and uncertainty propagation

    DOE PAGES

    Ibrahim, Ahmad M.; Peplow, Douglas E.; Grove, Robert E.; Peterson, Joshua L.; Johnson, Seth R.

    2015-12-01

    Shutdown dose rate (SDDR) analysis requires (a) a neutron transport calculation to estimate neutron flux fields, (b) an activation calculation to compute radionuclide inventories and associated photon sources, and (c) a photon transport calculation to estimate final SDDR. In some applications, accurate full-scale Monte Carlo (MC) SDDR simulations are needed for very large systems with massive amounts of shielding materials. However, these simulations are impractical because calculation of space- and energy-dependent neutron fluxes throughout the structural materials is needed to estimate distribution of radioisotopes causing the SDDR. Biasing the neutron MC calculation using an importance function is not simple becausemore » it is difficult to explicitly express the response function, which depends on subsequent computational steps. Furthermore, the typical SDDR calculations do not consider how uncertainties in MC neutron calculation impact SDDR uncertainty, even though MC neutron calculation uncertainties usually dominate SDDR uncertainty.« less

  14. The Multi-Step CADIS method for shutdown dose rate calculations and uncertainty propagation

    SciTech Connect

    Ibrahim, Ahmad M.; Peplow, Douglas E.; Grove, Robert E.; Peterson, Joshua L.; Johnson, Seth R.

    2015-12-01

    Shutdown dose rate (SDDR) analysis requires (a) a neutron transport calculation to estimate neutron flux fields, (b) an activation calculation to compute radionuclide inventories and associated photon sources, and (c) a photon transport calculation to estimate final SDDR. In some applications, accurate full-scale Monte Carlo (MC) SDDR simulations are needed for very large systems with massive amounts of shielding materials. However, these simulations are impractical because calculation of space- and energy-dependent neutron fluxes throughout the structural materials is needed to estimate distribution of radioisotopes causing the SDDR. Biasing the neutron MC calculation using an importance function is not simple because it is difficult to explicitly express the response function, which depends on subsequent computational steps. Furthermore, the typical SDDR calculations do not consider how uncertainties in MC neutron calculation impact SDDR uncertainty, even though MC neutron calculation uncertainties usually dominate SDDR uncertainty.

  15. A model of northern pintail productivity and population growth rate

    USGS Publications Warehouse

    Flint, P.L.; Grand, J.B.; Rockwell, R.F.

    1998-01-01

    Our objective was to synthesize individual components of reproductive ecology into a single estimate of productivity and to assess the relative effects of survival and productivity on population dynamics. We used information on nesting ecology, renesting potential, and duckling survival of northern pintails (Anas acuta) collected on the Yukon-Kuskokvim Delta (Y-K Delta), Alaska, 1991-95, to model the number of ducklings produced under a range of nest success and duckling survival probabilities. Using average values of 25% nest success, 11% duckling survival, and 56% renesting probability from our study population, we calculated that all young in our population were produced by 13% of the breeding females, and that early-nesting females produced more young than later-nesting females. Further, we calculated, on average, that each female produced only 0.16 young females/nesting season. We combined these results with estimates of first-year and adult survival to examine the growth rate (??) of the population and the relative contributions of these demographic parameters to that growth rate. Contrary to aerial survey data, the population projection model suggests our study population is declining rapidly (?? = 0.6969). The relative effects on population growth rate were 0.1175 for reproductive success, 0.1175 for first-year survival, and 0.8825 for adult survival. Adult survival had the greatest influence on ?? for our population, and this conclusion was robust over a range of survival and productivity estimates. Given published estimates of annual survival for adult females (61%), our model suggested nest success and duckling survival need to increase to approximately 40% to achieve population stability. We discuss reasons for the apparent discrepancy in population trends between our model and aerial surveys in terms of bias in productivity and survival estimates.

  16. 39 CFR 3010.23 - Calculation of percentage change in rates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... rate cell in the class is multiplied by the planned rate for the respective cell and the resulting products are summed. Then, the same set of rate cell volumes are multiplied by the corresponding current...) The term rate cell as applied in the test for compliance with the annual limitation shall apply...

  17. 39 CFR 3010.23 - Calculation of percentage change in rates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... rate cell in the class is multiplied by the planned rate for the respective cell and the resulting products are summed. Then, the same set of rate cell volumes are multiplied by the corresponding current...) The term rate cell as applied in the test for compliance with the annual limitation shall apply...

  18. Calculations of long-lived isomer production in neutron reactions

    SciTech Connect

    Chadwick, M.B.; Young, P.G.

    1991-01-01

    We present theoretical calculations for the production of the long-lived isomers: {sup 121m}Sn (11/2-, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider mainly (n,2n) production modes, but also (n,n{sup {prime}}) and (n,{gamma}) where necessary, and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have not been experimentally resolved, were reconstructed. 16 refs., 9 figs., 6 tabs.

  19. Cosmogenic Ne-21 Production Rates in H-Chondrites Based on Cl-36 - Ar-36 Ages

    NASA Technical Reports Server (NTRS)

    Leya, I.; Graf, Th.; Nishiizumi, K.; Guenther, D.; Wieler, R.

    2000-01-01

    We measured Ne-21 production rates in 14 H-chondrites in good agreement with model calculations. The production rates are based on Ne-21 concentrations measured on bulk samples or the non-magnetic fraction and Cl-36 - Ar-36 ages determined from the metal phase.

  20. Production rates of cosmogenic nuclei on the lunar surface

    NASA Astrophysics Data System (ADS)

    Dong, Tie-Kuang; Yun, Su-Jun; Ma, Tao; Chang, Jin; Dong, Wu-Dong; Zhang, Xiao-Ping; Li, Guo-Long; Ren, Zhong-Zhou

    2014-07-01

    A physical model for Geant4-based simulation of the galactic cosmic ray (GCR) particles' interaction with the lunar surface matter has been developed to investigate the production rates of cosmogenic nuclei. In this model the GCRs, mainly very high energy protons and α particles, bombard the surface of the Moon and produce many secondary particles, such as protons and neutrons. The energies of protons and neutrons at different depths are recorded and saved as ROOT files, and the analytical expressions for the differential proton and neutron fluxes are obtained through the best-fit procedure using ROOT software. To test the validity of this model, we calculate the production rates of the long-lived nuclei 10Be and 26Al in the Apollo 15 long drill core by combining the above differential fluxes and the newly evaluated spallation reaction cross sections. Our numerical results show that the theoretical production rates agree quite well with the measured data, which means that this model works well. Therefore, it can be expected that this model can be used to investigate the cosmogenic nuclei in future lunar samples returned by the Chinese lunar exploration program and can be extended to study other objects, such as meteorites and the Earth's atmosphere.

  1. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false SSV, CFV, and PDP molar flow rate calculations. 1065.642 Section 1065.642 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.642...

  2. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false SSV, CFV, and PDP molar flow rate calculations. 1065.642 Section 1065.642 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.642...

  3. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false SSV, CFV, and PDP molar flow rate calculations. 1065.642 Section 1065.642 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.642...

  4. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false SSV, CFV, and PDP molar flow rate calculations. 1065.642 Section 1065.642 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.642...

  5. An environmental impact calculator for greenhouse production systems.

    PubMed

    Torrellas, Marta; Antón, Assumpció; Montero, Juan Ignacio

    2013-03-30

    Multiple web-based calculators have come on the market as tools to support sustainable decision making, but few are available to agriculture. Life cycle assessment (LCA) has proved to be an objective, transparent tool for calculating environmental impacts throughout the life cycle of products and services, but can often be too complex for non-specialists. The objective of this study was therefore to develop an environmental support tool to determine the environmental impacts of protected crops. An effort was made to provide an easy-to-use tool in order to reach a wide audience and help horticulture stakeholders choose efficient options to mitigate the environmental impacts of protected crops. Users can estimate the environmental performance of their crops by entering a limited amount of data and following a few easy steps. A questionnaire must be answered with data on the crop, greenhouse dimensions, substrate, waste management, and the consumption of water, energy, fertilisers and pesticides. The calculator was designed as a simplified LCA, based on two scenarios analysed in detail in previous tasks of the EUPHOROS project and used as reference systems in this study. Two spreadsheets were provided based on these reference scenarios: one for a tomato crop in a multi-tunnel greenhouse under Southern European climate conditions and the other for a tomato crop in a Venlo glass greenhouse under Central European climate conditions. The selected functional unit was one tonne of tomatoes. Default data were given for each reference system for users who did not have complete specific data and to provide results for comparison with users' own results. The results were presented for water use as an inventory indicator and for the impact categories abiotic depletion, acidification, eutrophication, global warming, photochemical oxidation and cumulative energy demand. In the multi-tunnel greenhouse, the main contributors based on the default data were the structure, fertilisers

  6. Calculation of the biological effective dose for piecewise defined dose-rate fits

    SciTech Connect

    Hobbs, Robert F.; Sgouros, George

    2009-03-15

    An algorithmic solution to the biological effective dose (BED) calculation from the Lea-Catcheside formula for a piecewise defined function is presented. Data from patients treated for metastatic thyroid cancer were used to illustrate the solution. The Lea-Catcheside formula for the G-factor of the BED is integrated numerically using a large number of small trapezoidal fits to each integral. The algorithmically calculated BED is compatible with an analytic calculation for a similarly valued exponentially fitted dose-rate plot and is the only resolution for piecewise defined dose-rate functions.

  7. Carbon footprint of Canadian dairy products: calculations and issues.

    PubMed

    Vergé, X P C; Maxime, D; Dyer, J A; Desjardins, R L; Arcand, Y; Vanderzaag, A

    2013-09-01

    The Canadian dairy sector is a major industry with about 1 million cows. This industry emits about 20% of the total greenhouse gas (GHG) emissions from the main livestock sectors (beef, dairy, swine, and poultry). In 2006, the Canadian dairy herd produced about 7.7 Mt of raw milk, resulting in about 4.4 Mt of dairy products (notably 64% fluid milk and 12% cheese). An integrated cradle-to-gate model (field to processing plant) has been developed to estimate the carbon footprint (CF) of 11 Canadian dairy products. The on-farm part of the model is the Unified Livestock Industry and Crop Emissions Estimation System (ULICEES). It considers all GHG emissions associated with livestock production but, for this study, it was run for the dairy sector specifically. Off-farm GHG emissions were estimated using the Canadian Food Carbon Footprint calculator, (cafoo)(2)-milk. It considers GHG emissions from the farm gate to the exit gate of the processing plants. The CF of the raw milk has been found lower in western provinces [0.93 kg of CO2 equivalents (CO2e)/L of milk] than in eastern provinces (1.12 kg of CO2e/L of milk) because of differences in climate conditions and dairy herd management. Most of the CF estimates of dairy products ranged between 1 and 3 kg of CO2e/kg of product. Three products were, however, significantly higher: cheese (5.3 kg of CO2e/kg), butter (7.3 kg of CO2e/kg), and milk powder (10.1 kg of CO2e/kg). The CF results depend on the milk volume needed, the co-product allocation process (based on milk solids content), and the amount of energy used to manufacture each product. The GHG emissions per kilogram of protein ranged from 13 to 40 kg of CO2e. Two products had higher values: cream and sour cream, at 83 and 78 kg of CO2e/kg, respectively. Finally, the highest CF value was for butter, at about 730 kg of CO2e/kg. This extremely high value is due to the fact that the intensity indicator per kilogram of product is high and that butter is almost exclusively

  8. Carbon footprint of Canadian dairy products: calculations and issues.

    PubMed

    Vergé, X P C; Maxime, D; Dyer, J A; Desjardins, R L; Arcand, Y; Vanderzaag, A

    2013-09-01

    The Canadian dairy sector is a major industry with about 1 million cows. This industry emits about 20% of the total greenhouse gas (GHG) emissions from the main livestock sectors (beef, dairy, swine, and poultry). In 2006, the Canadian dairy herd produced about 7.7 Mt of raw milk, resulting in about 4.4 Mt of dairy products (notably 64% fluid milk and 12% cheese). An integrated cradle-to-gate model (field to processing plant) has been developed to estimate the carbon footprint (CF) of 11 Canadian dairy products. The on-farm part of the model is the Unified Livestock Industry and Crop Emissions Estimation System (ULICEES). It considers all GHG emissions associated with livestock production but, for this study, it was run for the dairy sector specifically. Off-farm GHG emissions were estimated using the Canadian Food Carbon Footprint calculator, (cafoo)(2)-milk. It considers GHG emissions from the farm gate to the exit gate of the processing plants. The CF of the raw milk has been found lower in western provinces [0.93 kg of CO2 equivalents (CO2e)/L of milk] than in eastern provinces (1.12 kg of CO2e/L of milk) because of differences in climate conditions and dairy herd management. Most of the CF estimates of dairy products ranged between 1 and 3 kg of CO2e/kg of product. Three products were, however, significantly higher: cheese (5.3 kg of CO2e/kg), butter (7.3 kg of CO2e/kg), and milk powder (10.1 kg of CO2e/kg). The CF results depend on the milk volume needed, the co-product allocation process (based on milk solids content), and the amount of energy used to manufacture each product. The GHG emissions per kilogram of protein ranged from 13 to 40 kg of CO2e. Two products had higher values: cream and sour cream, at 83 and 78 kg of CO2e/kg, respectively. Finally, the highest CF value was for butter, at about 730 kg of CO2e/kg. This extremely high value is due to the fact that the intensity indicator per kilogram of product is high and that butter is almost exclusively

  9. Addressing Fission Product Validation in MCNP Burnup Credit Criticality Calculations

    SciTech Connect

    Mueller, Don; Bowen, Douglas G; Marshall, William BJ J

    2015-01-01

    The US Nuclear Regulatory Commission (NRC) Division of Spent Fuel Storage and Transportation issued Interim Staff Guidance (ISG) 8, Revision 3 in September 2012. This ISG provides guidance for NRC staff members’ review of burnup credit (BUC) analyses supporting transport and dry storage of pressurized water reactor spent nuclear fuel (SNF) in casks. The ISG includes guidance for addressing validation of criticality (keff) calculations crediting the presence of a limited set of fission products and minor actinides (FP&MAs). Based on previous work documented in NRC Regulatory Guide (NUREG) Contractor Report (CR)-7109, the ISG recommends that NRC staff members accept the use of either 1.5 or 3% of the FP&MA worth—in addition to bias and bias uncertainty resulting from validation of keff calculations for the major actinides in SNF—to conservatively account for the bias and bias uncertainty associated with the specified unvalidated FP&MAs. The ISG recommends (1) use of 1.5% of the FP&MA worth if a modern version of SCALE and its nuclear data are used and (2) 3% of the FP&MA worth for well qualified, industry standard code systems other than SCALE with the Evaluated Nuclear Data Files, Part B (ENDF/B),-V, ENDF/B-VI, or ENDF/B-VII cross sections libraries. The work presented in this paper provides a basis for extending the use of the 1.5% of the FP&MA worth bias to BUC criticality calculations performed using the Monte Carlo N-Particle (MCNP) code. The extended use of the 1.5% FP&MA worth bias is shown to be acceptable by comparison of FP&MA worths calculated using SCALE and MCNP with ENDF/B-V, -VI, and -VII–based nuclear data. The comparison supports use of the 1.5% FP&MA worth bias when the MCNP code is used for criticality calculations, provided that the cask design is similar to the hypothetical generic BUC-32 cask model and that the credited FP&MA worth is no more than 0.1 Δkeff (ISG-8, Rev. 3, Recommendation 4).

  10. A Method for Calculating Transient Surface Temperatures and Surface Heating Rates for High-Speed Aircraft

    NASA Technical Reports Server (NTRS)

    Quinn, Robert D.; Gong, Leslie

    2000-01-01

    This report describes a method that can calculate transient aerodynamic heating and transient surface temperatures at supersonic and hypersonic speeds. This method can rapidly calculate temperature and heating rate time-histories for complete flight trajectories. Semi-empirical theories are used to calculate laminar and turbulent heat transfer coefficients and a procedure for estimating boundary-layer transition is included. Results from this method are compared with flight data from the X-15 research vehicle, YF-12 airplane, and the Space Shuttle Orbiter. These comparisons show that the calculated values are in good agreement with the measured flight data.

  11. Dose Rate Calculations for the 2-MCO/2-DHLW Waste Package

    SciTech Connect

    G. Radulescu

    2000-10-03

    The objective of this calculation is to determine the dose rates on the external surfaces of the waste package (WP) containing two Hanford defense high-level waste (DHLW) glass canisters and two Hanford multi-canister overpacks (MCO). Each MCO is loaded with the N Reactor spent nuclear fuel (SNF). The information provided by the sketches attached to this calculation is that of the potential design for the WP type considered in this calculation. The scope of this calculation is limited to reporting dose rates averaged over segments of the WP radial and axial surfaces and of surfaces 1 m and 2 m from the WP. The results of this calculation will be used to assess the shielding performance of the 2-MC012-DHLW WP engineering design.

  12. Steady State Flammable Gas Release Rate Calculation and Lower Flammability Level Evaluation for Hanford Tank Waste

    SciTech Connect

    HU, T.A.

    2001-02-23

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. Hydrogen generation rate was calculated for 177 tanks using rate equation model. Ammonia liquid/vapor equilibrium model is incorporated into the methodology for ammonia analysis.

  13. Steady State Flammable Gas Release Rate Calculation and Lower Flammability Level Evaluation for Hanford Tank Waste

    SciTech Connect

    HU, T.A.

    2000-04-27

    This work is to assess the steady-state flammability level at normal and off-normal ventilation conditions in the tank dome space for 177 double-shell and single-shell tanks at Hanford. Hydrogen generation rate was calculated for 177 tanks using rate equation model developed recently.

  14. 76 FR 5518 - Antidumping Proceedings: Calculation of the Weighted Average Dumping Margin and Assessment Rate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-01

    ... certain antidumping duty proceedings (75 FR 81533). That proposed rule and proposed modification indicated... Weighted Average Dumping Margin and Assessment Rate in Certain Antidumping Duty Proceedings AGENCY: Import... regarding the calculation of the weighted average dumping margin and antidumping duty assessment rate...

  15. Incorporation of measured photosynthetic rate in a mathematical model for calculation of non-structural saccharide concentration

    NASA Technical Reports Server (NTRS)

    Lim, J. T.; Raper, C. D. Jr; Gold, H. J.; Wilkerson, G. G.; Raper CD, J. r. (Principal Investigator)

    1989-01-01

    A simple mathematical model for calculating the concentration of mobile carbon skeletons in the shoot of soya bean plants [Glycine max (L.) Merrill cv. Ransom] was built to examine the suitability of measured net photosynthetic rates (PN) for calculation of saccharide flux into the plant. The results suggest that either measurement of instantaneous PN overestimated saccharide influx or respiration rates utilized in the model were underestimated. If neither of these is the case, end-product inhibition of photosynthesis or waste respiration through the alternative pathway should be included in modelling of CH2O influx or efflux; and even if either of these is the case, the model output at a low coefficient of leaf activity indicates that PN still may be controlled by either end-product inhibition or alternative respiration.

  16. Incorporation of measured photosynthetic rate in a mathematical model for calculation of non-structural saccharide concentration.

    PubMed

    Lim, J T; Raper, C D; Gold, H J; Wilkerson, G G

    1989-01-01

    A simple mathematical model for calculating the concentration of mobile carbon skeletons in the shoot of soya bean plants [Glycine max (L.) Merrill cv. Ransom] was built to examine the suitability of measured net photosynthetic rates (PN) for calculation of saccharide flux into the plant. The results suggest that either measurement of instantaneous PN overestimated saccharide influx or respiration rates utilized in the model were underestimated. If neither of these is the case, end-product inhibition of photosynthesis or waste respiration through the alternative pathway should be included in modelling of CH2O influx or efflux; and even if either of these is the case, the model output at a low coefficient of leaf activity indicates that PN still may be controlled by either end-product inhibition or alternative respiration.

  17. Effects of stress rate and calculation method on subcritical crack growth parameters deduced from constant stress-rate flexural testing

    PubMed Central

    Griggs, Jason A.; Alaqeel, Samer M.; Zhang, Yunlong; Miller, Amp W.; Cai, Zhuo

    2011-01-01

    Objectives To more efficiently determine the subcritical crack growth (SCG) parameters of dental ceramics, the effects of stressing rate and choice of statistical regression model on estimates of SCG parameters were assessed. Methods Two dental ceramic materials, a veneering material having a single critical flaw population (S) and a framework material having partially concurrent flaw populations (PC), were analyzed using constant stress-rate testing, or “dynamic fatigue”, with a variety of testing protocols. For each material, 150 rectangular beam specimens were prepared and tested in four-point flexure according to ISO6872 and ASTM1368. A full-factorial study was conducted on the following factors: material, stress rate assumed vs. calculated, number of stress rates, and statistical regression method. Results The proportion of specimens for which the statistical models over-estimated reliability was not significantly different based on regression method for Material S (P = 0.96, power = 94%) and was significantly different based on regression method for Material PC (P < 0.001). The standard method resulted in SCG parameters, n and ln B, of 35.9 and -11.1 MPa2s for Material S and 12.4 and 9.61 MPa2s for Material PC. Significance The method of calculation that uses only the median strength value at each stress rate provided the most robust SCG parameter estimates. Using only two stress rates resulted in fatigue parameters comparable to those estimated using four stress rates having the same range. The stress rate of each specimen can be assumed to be the target stress rate with negligible difference in SCG parameter estimates. PMID:21167586

  18. Tables of Nuclear Cross Sections and Reaction Rates: AN Addendum to the Paper ``ASTROPHYSICAL Reaction Rates from Statistical Model Calculations'' ()

    NASA Astrophysics Data System (ADS)

    Rauscher, Thomas; Thielemann, Friedrich-Karl

    2001-09-01

    In a previous publication (ATOMIC DATAAND NUCLEAR DATA TABLES75, 1 (2000)), we gave seven-parameter analytical fits to theoretical reaction rates derived from nuclear cross sections calculated in the statistical model (Hauser-Feshbach formalism) for targets with 10<=Z<=83 (Ne to Bi) and for a mass range reaching the neutron and proton driplines. Reactions considered were (n,γ), (n,p), (n,α), (p,γ), (p,α), (α,γ), and their inverse reactions. Here, we present the theoretical nuclear cross sections and astrophysical reaction rates from which those rate fits were derived, and we provide these data as on-line electronic files. Corresponding to the fitted rates, two complete data sets are provided, one of which includes a phenomenological treatment of shell quenching for neutron-rich nuclei.

  19. Calculated ionization rates, ion densities, and airglow emission rates due to precipitating electrons in the nightside ionosphere of Mars

    NASA Technical Reports Server (NTRS)

    Haider, S. A.; Kim, J.; Nagy, A. F.; Keller, C. N.; Verigin, M. I.; Gringauz, K. I.; Shutte, N. M.; Szego, K.; Kiraly, P.

    1992-01-01

    The calculations presented in this paper clearly establish that the electron fluxes measured by the HARP instrument, carried on board Phobos 2, could cause significant electron impact ionization and excitation in the nightside atmosphere of Mars, if these electrons actually do precipitate. The calculated peak electron densities were found to be about a factor of 2 larger than the mean observed nightside densities, indicating that if a significant fraction of the measured electrons actually precipitate, they could be the dominant mechanism responsible for maintaining the nightside ionosphere. The calculated zenith column emission rates of the O I 5577-A and 6300-A and CO Cameron band emissions, due to electron impact and dissociative recombination mechanisms, were found to be significant.

  20. Ab Initio Calculation of Rate Constants for Molecule-Surface Reactions with Chemical Accuracy.

    PubMed

    Piccini, GiovanniMaria; Alessio, Maristella; Sauer, Joachim

    2016-04-18

    The ab initio prediction of reaction rate constants for systems with hundreds of atoms with an accuracy that is comparable to experiment is a challenge for computational quantum chemistry. We present a divide-and-conquer strategy that departs from the potential energy surfaces obtained by standard density functional theory with inclusion of dispersion. The energies of the reactant and transition structures are refined by wavefunction-type calculations for the reaction site. Thermal effects and entropies are calculated from vibrational partition functions, and the anharmonic frequencies are calculated separately for each vibrational mode. This method is applied to a key reaction of an industrially relevant catalytic process, the methylation of small alkenes over zeolites. The calculated reaction rate constants (free energies), pre-exponential factors (entropies), and enthalpy barriers show that our computational strategy yields results that agree with experiment within chemical accuracy limits (less than one order of magnitude).

  1. Ab Initio Calculation of Rate Constants for Molecule–Surface Reactions with Chemical Accuracy

    PubMed Central

    Piccini, GiovanniMaria; Alessio, Maristella

    2016-01-01

    Abstract The ab initio prediction of reaction rate constants for systems with hundreds of atoms with an accuracy that is comparable to experiment is a challenge for computational quantum chemistry. We present a divide‐and‐conquer strategy that departs from the potential energy surfaces obtained by standard density functional theory with inclusion of dispersion. The energies of the reactant and transition structures are refined by wavefunction‐type calculations for the reaction site. Thermal effects and entropies are calculated from vibrational partition functions, and the anharmonic frequencies are calculated separately for each vibrational mode. This method is applied to a key reaction of an industrially relevant catalytic process, the methylation of small alkenes over zeolites. The calculated reaction rate constants (free energies), pre‐exponential factors (entropies), and enthalpy barriers show that our computational strategy yields results that agree with experiment within chemical accuracy limits (less than one order of magnitude). PMID:27008460

  2. Relating Productivity Events to Holocene Bivalve Shell Growth Rates

    NASA Astrophysics Data System (ADS)

    Huntley, J. W.; Krause, R. A.; Kowalewski, M.; Romanek, C. S.; Kaufman, D. S.; Simoes, M. G.

    2007-12-01

    The growth rate of a bivalve can be influenced by many environmental factors that can change during the life of the organism. In this contribution we present initial data from a millennium scale chronology to assess the relationship between ontogenetic growth in the bivalve Semele casali and paleoenvironmental conditions preserved in the shell using growth increment analysis, radiocarbon-calibrated amino acid racemization dating techniques, stable isotopes (C and O) and high spatial resolution (125-150 samples per cm of shell profile) trace element (Ba, Mn) analysis (LA-ICPMS). Time-averaged specimens of S. casali were dredged from two sites at 10 meters and 30 meters depth along the inner continental shelf at Ubatuba Bay in the Southeast Brazilian Bight, an area influenced by productivity pulses triggered by coastal runoff events and coastal upwelling. Seventy-five individual valves were dated using amino acid racemization (aspartic acid). Dates were calculated using an expanded version of a previously published relationship (Barbour Wood et al., 2006 Quaternary Research 323- 331) between aspartic acid ratios and AMS radiocarbon dates of twelve S. casali individuals from the same sampling locations. The resulting time series has complete coverage for the past three thousand years at centennial resolution. From this time series, a sub-sample of dated valves was selected for more detailed growth increment, stable isotope and high-resolution trace element (Ba/Ca and Mn/Ca) analyses. Oceanic productivity is expressed differentially in the trace element profiles of S. casali with elevated Ba/Ca and Mn/Ca ratios capturing nutrient input through coastal runoff events while elevated Ba/Ca and depressed Mn/Ca ratios represent input through coastal upwelling. Fluctuations in Ba/Ca and Mn/Ca are not correlated to fluctuations in relative growth throughout the ontogeny of an individual bivalve, nor are they expected to be as periods of increased productivity are transient

  3. Benchmarking of Monte Carlo based shutdown dose rate calculations for applications to JET.

    PubMed

    Petrizzi, L; Batistoni, P; Fischer, U; Loughlin, M; Pereslavtsev, P; Villari, R

    2005-01-01

    The calculation of dose rates after shutdown is an important issue for operating nuclear reactors. A validated computational tool is needed for reliable dose rate calculations. In fusion reactors neutrons induce high levels of radioactivity and presumably high doses. The complex geometries of the devices require the use of sophisticated geometry modelling and computational tools for transport calculations. Simple rule of thumb laws do not always apply well. Two computational procedures have been developed recently and applied to fusion machines. Comparisons between the two methods showed some inherent discrepancies when applied to calculation for the ITER while good agreement was found for a 14 MeV point source neutron benchmark experiment. Further benchmarks were considered necessary to investigate in more detail the reasons for the different results in different cases. In this frame the application to the Joint European Torus JET machine has been considered as a useful benchmark exercise. In a first calculational benchmark with a representative D-T irradiation history of JET the two methods differed by no more than 25%. In another, more realistic benchmark exercise, which is the subject of this paper, the real irradiation history of D-T and D-D campaigns conducted at JET in 1997-98 were used to calculate the shut-down doses at different locations, irradiation and decay times. Experimental dose data recorded at JET for the same conditions offer the possibility to check the prediction capability of the calculations and thus show the applicability (and the constraints) of the procedures and data to the rather complex shutdown dose rate analysis of real fusion devices. Calculation results obtained by the two methods are reported below, comparison with experimental results give discrepancies ranging between 2 and 10. The reasons of that can be ascribed to the high uncertainty on the experimental data and the unsatisfactory JET model used in the calculation. A new

  4. Rate constant calculations of H-atom abstraction reactions from ethers by HȮ2 radicals.

    PubMed

    Mendes, Jorge; Zhou, Chong-Wen; Curran, Henry J

    2014-02-27

    In this work, we detail hydrogen atom abstraction reactions from six ethers by the hydroperoxyl radical, including dimethyl ether, ethyl methyl ether, propyl methyl ether, isopropyl methyl ether, butyl methyl ether, and isobutyl methyl ether, in order to test the effect of the functional group on the rate constant calculations. The Møller-Plesset (MP2) method with the 6-311G(d,p) basis set has been employed in the geometry optimizations and frequency calculations of all of the species involved in the above reaction systems. The connections between each transition state and the corresponding local minima have been determined by intrinsic reaction coordinate calculations. Energies are reported at the CCSD(T)/cc-pVTZ level of theory and include the zero-point energy corrections. As a benchmark in the electronic energy calculations, the CCSD(T)/CBS extrapolation was used for the reactions of dimethyl ether + HȮ2 radicals. A systematic calculation of the high-pressure limit rate constants has been performed using conventional transition-state theory, including asymmetric Eckart tunneling corrections, in the temperature range of 500-2000 K. The one dimensional hindrance potentials obtained at MP2/6-311G(d,p) for the reactants and transition states have been used to describe the low frequency torsional modes. Herein, we report the calculated individual, average, and total rate constants. A branching ratio analysis for every reaction site has also been performed. PMID:24483837

  5. Absolute rate calculations: atom and proton transfers in hydrogen-bonded systems.

    PubMed

    Barroso, Mónica; Arnaut, Luis G; Formosinho, Sebastião J

    2005-02-01

    We calculate energy barriers of atom- and proton-transfer reactions in hydrogen-bonded complexes in the gas phase. Our calculations do not involve adjustable parameters and are based on bond-dissociation energies, ionization potentials, electron affinities, bond lengths, and vibration frequencies of the reactive bonds. The calculated barriers are in agreement with experimental data and high-level ab initio calculations. We relate the height of the barrier with the molecular properties of the reactants and complexes. The structure of complexes with strong hydrogen bonds approaches that of the transition state, and substantially reduces the barrier height. We calculate the hydrogen-abstraction rates in H-bonded systems using the transition-state theory with the semiclassical correction for tunneling, and show that they are in excellent agreement with the experimental data. H-bonding leads to an increase in tunneling corrections at room temperature. PMID:15751360

  6. O₂migration rates in [NiFe] hydrogenases. A joint approach combining free-energy calculations and kinetic modeling.

    PubMed

    Topin, Jérémie; Diharce, Julien; Fiorucci, Sébastien; Antonczak, Serge; Golebiowski, Jérôme

    2014-01-23

    Hydrogenases are promising candidates for the catalytic production of green energy by means of biological ways. The major impediment to such a production is rooted in their inhibition under aerobic conditions. In this work, we model dioxygen migration rates in mutants of a hydrogenase of Desulfovibrio fructusovorans. The approach relies on the calculation of the whole potential of mean force for O2 migration within the wild-type as well as in V74M, V74F, and V74Q mutant channels. The three free-energy barriers along the entire migration pathway are converted into chemical rates through modeling based on Transition State Theory. The use of such a model recovers the trend of O2 migration rates among the series.

  7. Pair production rates in mildly relativistic, magnetized plasmas

    NASA Technical Reports Server (NTRS)

    Burns, M. L.; Harding, A. K.

    1984-01-01

    Electron-positron pairs may be produced by either one or two photons in the presence of a strong magnetic field. In magnetized plasmas with temperatures kT approximately sq mc, both of these processes may be important and could be competitive. The rates of one-photon and two-photon pair production by photons with Maxwellian, thermal bremsstrahlung, thermal synchrotron and power law spectra are calculated as a function of temperature or power law index and field strength. This allows a comparison of the two rates and a determination of the conditions under which each process may be a significant source of pairs in astrophysical plasmas. It is found that for photon densities n(gamma) or = 10 to the 25th power/cu cm and magnetic field strengths B or = 10 to the 12th power G, one-photon pair production dominates at kT approximately sq mc for a Maxwellian, at kT approximately 2 sq mc for a thermal bremsstrahlung spectrum, at all temperatures for a thermal synchrotron spectrum, and for power law spectra with indices s approximately 4.

  8. A rapid and accurate method for calculation of stratospheric photolysis rates with molecular scattering

    NASA Technical Reports Server (NTRS)

    Boughner, Robert E.

    1986-01-01

    A method for calculating the photodissociation rates needed for photochemical modeling of the stratosphere, which includes the effects of molecular scattering, is described. The procedure is based on Sokolov's method of averaging functional correction. The radiation model and approximations used to calculate the radiation field are examined. The approximated diffuse fields and photolysis rates are compared with exact data. It is observed that the approximate solutions differ from the exact result by 10 percent or less at altitudes above 15 km; the photolysis rates differ from the exact rates by less than 5 percent for altitudes above 10 km and all zenith angles, and by less than 1 percent for altitudes above 15 km.

  9. Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes

    SciTech Connect

    Nabi, Jameel-Un; Tawfik, Abdel Nasser

    2013-03-15

    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y{sub e}) of the corematerial. It is suggested that the temporal variation of Y{sub e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly {sup 54-56}Fe, are considered to be key players in controlling Y{sub e} ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y{sub e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on {sup 54-56}Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.

  10. 30 CFR 1206.352 - How do I calculate the royalty due on geothermal resources used for commercial production or...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... electricity multiplied by the royalty rate BLM prescribed for your lease under 43 CFR 3211.17. See § 1206.361...; or (2) The royalty rate that BLM prescribes or calculates under 43 CFR 3211.17. See § 1206.361 for... geothermal resources used for commercial production or generation of electricity? 1206.352 Section...

  11. 30 CFR 206.352 - How do I calculate the royalty due on geothermal resources used for commercial production or...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; or (2) The royalty rate that BLM prescribes or calculates under 43 CFR 3211.17. See § 206.361 for... multiplied by the royalty rate BLM prescribed for your lease under 43 CFR 3211.17. See § 206.361 for... geothermal resources used for commercial production or generation of electricity? 206.352 Section...

  12. 30 CFR 1206.352 - How do I calculate the royalty due on geothermal resources used for commercial production or...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... electricity multiplied by the royalty rate BLM prescribed for your lease under 43 CFR 3211.17. See § 1206.361...; or (2) The royalty rate that BLM prescribes or calculates under 43 CFR 3211.17. See § 1206.361 for... geothermal resources used for commercial production or generation of electricity? 1206.352 Section...

  13. 30 CFR 1206.352 - How do I calculate the royalty due on geothermal resources used for commercial production or...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... electricity multiplied by the royalty rate BLM prescribed for your lease under 43 CFR 3211.17. See § 1206.361...; or (2) The royalty rate that BLM prescribes or calculates under 43 CFR 3211.17. See § 1206.361 for... geothermal resources used for commercial production or generation of electricity? 1206.352 Section...

  14. Results of Propellant Mixing Variable Study Using Precise Pressure-Based Burn Rate Calculations

    NASA Technical Reports Server (NTRS)

    Stefanski, Philip L.

    2014-01-01

    A designed experiment was conducted in which three mix processing variables (pre-curative addition mix temperature, pre-curative addition mixing time, and mixer speed) were varied to estimate their effects on within-mix propellant burn rate variability. The chosen discriminator for the experiment was the 2-inch diameter by 4-inch long (2x4) Center-Perforated (CP) ballistic evaluation motor. Motor nozzle throat diameters were sized to produce a common targeted chamber pressure. Initial data analysis did not show a statistically significant effect. Because propellant burn rate must be directly related to chamber pressure, a method was developed that showed statistically significant effects on chamber pressure (either maximum or average) by adjustments to the process settings. Burn rates were calculated from chamber pressures and these were then normalized to a common pressure for comparative purposes. The pressure-based method of burn rate determination showed significant reduction in error when compared to results obtained from the Brooks' modification of the propellant web-bisector burn rate determination method. Analysis of effects using burn rates calculated by the pressure-based method showed a significant correlation of within-mix burn rate dispersion to mixing duration and the quadratic of mixing duration. The findings were confirmed in a series of mixes that examined the effects of mixing time on burn rate variation, which yielded the same results.

  15. Accuracy of heart strain rate calculation derived from Doppler tissue velocity data

    NASA Astrophysics Data System (ADS)

    Santos, Andres; Ledesma-Carbayo, Maria J.; Malpica, Norberto; Desco, Manuel; Antoranz, Jose C.; Marcos-Alberca, Pedro; Garcia-Fernandez, Miguel A.

    2001-05-01

    Strain Rate (SR) Imaging is a recent imaging technique that provides information about regional myocardial deformation by measuring local compression and expansion rates. SR can be obtained by calculating the local in-plane velocity gradients along the ultrasound beam from Doppler Tissue velocity data. However, SR calculations are very dependent on the image noise and artifacts, and different calculation algorithms may provide inconsistent results. This paper compares techniques to calculate SR. 2D Doppler Tissue Images (DTI) are acquired with an Acuson Sequoia scanner. Noise was measured with the aid of a rotating phantom. Processing is performed on polar coordinates. For each image, after removal of black spot artifacts by a selective median filter, two different SR calculation methods have been implemented. In the first one, SR is computed as the discrete velocity derivative, and noise is reduced with a variable-width gaussian filter. In the second method a smoothing cubic spine is calculated for every scan line according to the noise level and the derivative is obtained from an analytical expression. Both methods have been tested with DTI data from synthetic phantoms and normal volunteers. Results show that noise characteristics, border effects and the adequate scale are critical to obtain meaningful results.

  16. Calculating mercury loading to the tidal Hudson River, New York, using rating curve and surrogate methodologies

    USGS Publications Warehouse

    Wall, G.R.; Ingleston, H.H.; Litten, S.

    2005-01-01

    Total mercury (THg) load in rivers is often calculated from a site-specific "rating-curve" based on the relation between THg concentration and river discharge along with a continuous record of river discharge. However, there is no physical explanation as to why river discharge should consistently predict THg or any other suspended analyte. THg loads calculated by the rating-curve method were compared with those calculated by a "continuous surrogate concentration" (CSC) method in which a relation between THg concentration and suspended-sediment concentration (SSC) is constructed; THg loads then can be calculated from the continuous record of SSC and river discharge. The rating-curve and CSC methods, respectively, indicated annual THg loads of 46.4 and 75.1 kg for the Mohawk River, and 52.9 and 33.1 kg for the upper Hudson River. Differences between the results of the two methods are attributed to the inability of the rating-curve method to adequately characterize atypical high flows such as an ice-dam release, or to account for hysteresis, which typically degrades the strength of the relation between stream discharge and concentration of material in suspension. ?? Springer 2005.

  17. Autoradiography-based, three-dimensional calculation of dose rate for murine, human-tumor xenografts.

    PubMed

    Koral, K F; Kwok, C S; Yang, F E; Brown, R S; Sisson, J C; Wahl, R L

    1993-11-01

    A Fast Fourier Transform method for calculating the three-dimensional dose rate distribution for murine, human-tumor xenografts is outlined. The required input includes evenly-spaced activity slices which span the tumor. Numerical values in these slices are determined by quantitative 125I autoradiography. For the absorbed dose-rate calculation, we assume the activity from both 131I- and 90Y-labeled radiopharmaceuticals would be distributed as is measured with the 125I label. Two example cases are presented: an ovarian-carcinoma xenograft with an IgG 2ak monoclonal antibody and a neuroblastoma xenograft with meta-iodobenzylguanidine (MIBG). Considering all the volume elements in a tumor, we show, by comparison of histograms and also relative standard deviations, that the measured 125I activity and the calculated 131I dose-rate distributions, are similarly non-uniform and that they are more non-uniform than the calculated 90Y dose-rate distribution. However, the maximum-to-minimum ratio, another measure of non-uniformity, decreases by roughly an order of magnitude from one distribution to the next in the order given above. PMID:8298569

  18. 34 CFR 668.202 - Calculating and applying cohort default rates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fiscal year following the fiscal year in which it entered repayment— (i) Rehabilitated under 34 CFR 682... steps that we follow to calculate and apply your cohort default rate for a fiscal year: (1) First, under paragraph (b) of this section, we identify the borrowers in your cohort for the fiscal year. If the...

  19. 34 CFR 668.183 - Calculating and applying cohort default rates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... four steps that we follow to calculate and apply your cohort default rate for a fiscal year: (1) First, under paragraph (b) of this section, we identify the borrowers in your cohort for the fiscal year. If... cohorts for the 2 most recent prior fiscal years. (2) Second, under paragraph (c) of this section,...

  20. 45 CFR 261.25 - Do we count Tribal families in calculating the work participation rate?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... approved Tribal family assistance plan or under a Tribal work program in calculating the State's... work participation rate? 261.25 Section 261.25 Public Welfare Regulations Relating to Public Welfare... OF HEALTH AND HUMAN SERVICES ENSURING THAT RECIPIENTS WORK What Are the Provisions Addressing...

  1. Prospective calculation of identification power for individual genes in analyses controlling the false discovery rate.

    PubMed

    Crager, Michael R

    2012-12-01

    Recent work on prospective power and sample size calculations for analyses of high-dimension gene expression data that control the false discovery rate (FDR) focuses on the average power over all the truly nonnull hypotheses, or equivalently, the expected proportion of nonnull hypotheses rejected. Using another characterization of power, we adapt Efron's ([2007] Ann Stat 35:1351-1377) empirical Bayes approach to post hoc power calculation to develop a method for prospective calculation of the "identification power" for individual genes. This is the probability that a gene with a given true degree of association with clinical outcome or state will be included in a set within which the FDR is controlled at a specified level. An example calculation using proportional hazards regression highlights the effects of large numbers of genes with little or no association on the identification power for individual genes with substantial association.

  2. Effects of surface pressures and streamline metrics on the calculation of laminar heating rates

    NASA Technical Reports Server (NTRS)

    Riley, Christopher J.; Dejarnette, Fred R.; Zoby, Vincent

    1988-01-01

    The effect of streamline geometry and pressure distributions on surface heating rates is examined for slender, spherically blunted cones. The modifications to the approximate aeroheating code include a curve fit of pressures computed by an Euler solution over a range of Mach numbers and cone angles. The streamline geometry is then found using the surface pressures and inviscid surface properties. Previously, streamlines were determined using the inviscid properties at the edge of the boundary layer when accounting for the effects of entropy-layer swallowing. Streamline calculations are now based on inviscid surface conditions rather than boundary-layer edge properties. However, the heating rates are calculated using inviscid properties at the edge of the boundary layer. Resulting heating rates compare favorably with solutions from the viscous-shock-layer equations.

  3. Calculated diffusion coefficients and the growth rate of olivine in a basalt magma

    NASA Technical Reports Server (NTRS)

    Donaldson, C. H.

    1975-01-01

    Concentration gradients in glass adjacent to skeletal olivines in a basalt have been examined by electron probe. The glass is depleted in Mg, Fe, and Cr and enriched in Si, Al, Na, and Ca relative to that far from olivine. Ionic diffusion coefficients for the glass compositions are calculated from temperature, ionic radius and melt viscosity, using the Stokes-Einstein relation. At 1170 C, the diffusion coefficient of Mg(2+) ions in the basalt is 4.5 billionths sq cm per sec. Comparison with measured diffusion coefficients in a mugearite suggests this value may be 16 times too small. The concentration gradient data and the diffusion coefficients are used to calculate instantaneous olivine growth rates. Growth necessarily preceded emplacement such that the composition of the crystals plus the enclosing glass need not be that of a melt. The computed olivine growth rates are compatible with the rate of crystallization deduced for the Skaegaard intrusion.

  4. CHARADE: A characteristic code for calculating rate-dependent shock-wave response

    SciTech Connect

    Johnson, J.N.; Tonks, D.L.

    1991-01-01

    In this report we apply spatially one-dimensional methods and simple shock-tracking techniques to the solution of rate-dependent material response under flat-plate-impact conditions. This method of solution eliminates potential confusion of material dissipation with artificial dissipative effects inherent in finite-difference codes, and thus lends itself to accurate calculation of elastic-plastic deformation, shock-to-detonation transition in solid explosives, and shock-induced structural phase transformation. Equations are presented for rate-dependent thermoelastic-plastic deformation for (100) planar shock-wave propagation in materials of cubic symmetry (or higher). Specific numerical calculations are presented for polycrystalline copper using the mechanical threshold stress model of Follansbee and Kocks with transition to dislocation drag. A listing of the CHARADE (for characteristic rate dependence) code and sample input deck are given. 26 refs., 11 figs.

  5. Aftershock production rate of driven viscoelastic interfaces.

    PubMed

    Jagla, E A

    2014-10-01

    We study analytically and by numerical simulations the statistics of the aftershocks generated after large avalanches in models of interface depinning that include viscoelastic relaxation effects. We find in all the analyzed cases that the decay law of aftershocks with time can be understood by considering the typical roughness of the interface and its evolution due to relaxation. In models where there is a single viscoelastic relaxation time there is an exponential decay of the number of aftershocks with time. In models in which viscoelastic relaxation is wave-vector dependent we typically find a power-law dependence of the decay rate that is compatible with the Omori law. The factors that determine the value of the decay exponent are analyzed.

  6. Rapid calculation of functional maps of glucose metabolic rate and individual model rate parameters from serial 2-FDG images

    SciTech Connect

    Koeppe, R.A.; Holden, J.E.; Hutchins, G.D.

    1985-05-01

    The authors have developed a method for the rapid pixel-by-pixel estimation of glucose metabolic rate from a dynamic sequence of PCT images acquired over 40 minutes following venous bolus injection of 2-deoxy-2-fluoro-D-glucose (2-FDG). The calculations are based on the conventional four parameter model. The dephosphorylation rate (k/sub 4/) cannot be reliably estimated from only 40 minutes of data; however, neglecting dephosphorylation can nonetheless introduce significant biases into the parameter estimation processes. In the authors' method, the rate is constrained to fall within a small range about a presumed value. Computer simulation studies show that this constraint greatly reduces the systematic biases in the other three fitted parameters and in the metabolic rate that arise from the assumption of no dephosphorylation. The parameter estimation scheme used is formally identical to one originally developed for dynamic methods of cerebral blood flow estimation. Estimation of metabolic rate and the individual model rate parameters k/sub 1/, k/sub 2/, and k/sub 3/, can be carried out for each pixel sequence of a 100 x 100 pixel image in less than two minutes on our PDP 11/60 minicomputer with floating point processor. While the maps of k/sub 2/ amd k/sub 3/ are quite noisy, accurate estimates of average values can be attained for regions of a few cm/sup 2/. The maps of metabolic rate offer many advantages in addition to that of direct visualization. These include improved statistical precision and the avoidance of averaging failure in the fitting of heterogeneous regions.

  7. Low temperature rate constants for the N + CN → N2 + C reaction: two-dimensional quantum capture calculations on an accurate potential energy surface.

    PubMed

    Ma, Jianyi; Guo, Hua; Dawes, Richard

    2012-09-21

    The title reaction is thought to be responsible for the production of molecular nitrogen in interstellar clouds. In this work, we report quantum capture calculations on a new two-dimensional potential energy surface determined by interpolating high-level ab initio data. The low-temperature rate constant calculated using a capture model is quite large and has a positive temperature dependence, in agreement with a recent experiment. The origin of the aforementioned behaviors of the rate constant is analyzed.

  8. Effects of heterogeneity in aquifer permeability and biomass on biodegradation rate calculations - Results from numerical simulations

    USGS Publications Warehouse

    Scholl, M.A.

    2000-01-01

    Numerical simulations were used to examine the effects of heterogeneity in hydraulic conductivity (K) and intrinsic biodegradation rate on the accuracy of contaminant plume-scale biodegradation rates obtained from field data. The simulations were based on a steady-state BTEX contaminant plume-scale biodegradation under sulfate-reducing conditions, with the electron acceptor in excess. Biomass was either uniform or correlated with K to model spatially variable intrinsic biodegradation rates. A hydraulic conductivity data set from an alluvial aquifer was used to generate three sets of 10 realizations with different degrees of heterogeneity, and contaminant transport with biodegradation was simulated with BIOMOC. Biodegradation rates were calculated from the steady-state contaminant plumes using decreases in concentration with distance downgradient and a single flow velocity estimate, as is commonly done in site characterization to support the interpretation of natural attenuation. The observed rates were found to underestimate the actual rate specified in the heterogeneous model in all cases. The discrepancy between the observed rate and the 'true' rate depended on the ground water flow velocity estimate, and increased with increasing heterogeneity in the aquifer. For a lognormal K distribution with variance of 0.46, the estimate was no more than a factor of 1.4 slower than the true rate. For aquifer with 20% silt/clay lenses, the rate estimate was as much as nine times slower than the true rate. Homogeneous-permeability, uniform-degradation rate simulations were used to generate predictions of remediation time with the rates estimated from heterogeneous models. The homogeneous models were generally overestimated the extent of remediation or underestimated remediation time, due to delayed degradation of contaminants in the low-K areas. Results suggest that aquifer characterization for natural attenuation at contaminated sites should include assessment of the presence

  9. Numerical calculation of relative dose rates from spherical 106Ru beta sources used in ophthalmic brachytherapy

    NASA Astrophysics Data System (ADS)

    de Paiva, Eduardo

    Concave beta sources of 106Ru/106Rh are used in radiotherapy to treat ophthalmic tumors. However, a problem that arises is the difficult determination of absorbed dose distributions around such sources mainly because of the small range of the electrons and the steep dose gradients. In this sense, numerical methods have been developed to calculate the dose distributions around the beta applicators. In this work a simple code in Fortran language is developed to estimate the dose rates along the central axis of 106Ru/106Rh curved plaques by numerical integration of the beta point source function and results are compared with other calculated data.

  10. Quantum Calculation of Inelastic CO Collisions with H. III. Rate Coefficients for Ro-vibrational Transitions

    NASA Astrophysics Data System (ADS)

    Song, L.; Balakrishnan, N.; Walker, K. M.; Stancil, P. C.; Thi, W. F.; Kamp, I.; van der Avoird, A.; Groenenboom, G. C.

    2015-11-01

    We present calculated rate coefficients for ro-vibrational transitions of CO in collisions with H atoms for a gas temperature range of 10 K ≤ T ≤ 3000 K, based on the recent three-dimensional ab initio H-CO interaction potential of Song et al. Rate coefficients for ro-vibrational v=1,j=0-30\\to v\\prime =0,j\\prime transitions were obtained from scattering cross sections previously computed with the close-coupling (CC) method by Song et al. Combining these with the rate coefficients for vibrational v=1-5\\to v\\prime \\lt v quenching obtained with the infinite-order sudden approximation, we propose a new extrapolation scheme that yields the rate coefficients for ro-vibrational v=2-5,j=0-30\\to v\\prime ,j\\prime de-excitation. Cross sections and rate coefficients for ro-vibrational v=2,j=0-30\\to v\\prime =1,j\\prime transitions calculated with the CC method confirm the effectiveness of this extrapolation scheme. Our calculated and extrapolated rates are very different from those that have been adopted in the modeling of many astrophysical environments. The current work provides the most comprehensive and accurate set of ro-vibrational de-excitation rate coefficients for the astrophysical modeling of the H-CO collision system. The application of the previously available and new data sets in astrophysical slab models shows that the line fluxes typically change by 20%-70% in high temperature environments (800 K) with an H/H2 ratio of 1; larger changes occur for lower temperatures.

  11. Development of a New Shielding Model for JB-Line Dose Rate Calculations

    SciTech Connect

    Buckner, M.R.

    2001-08-09

    This report describes the shielding model development for the JB-Line Upgrade project. The product of this effort is a simple-to-use but accurate method of estimating the personnel dose expected for various operating conditions on the line. The current techniques for shielding calculations use transport codes such as ANISN which, while accurate for geometries which can be accurately approximated as one dimensional slabs, cylinders or spheres, fall short in calculating configurations in which two-or three-dimensional effects (e.g., streaming) play a role in the dose received by workers.

  12. Radiolytic hydrogen production from process vessels in HB line - production rates compared to evolution rates and discussion of LASL reviews

    SciTech Connect

    Bibler, N.E.

    1992-11-12

    Hydrogen production from radiolysis of aqueous solutions can create a safety hazard since hydrogen is flammable. At times this production can be significant, especially in HB line where nitric acid solutions containing high concentrations of Pu-238, an intense alpha emitter, are processed. The hydrogen production rates from these solutions are necessary for safety analyses of these process systems. The methods and conclusions of hydrogen production rate tests are provided in this report.

  13. Regulation of primary productivity rate in the equatorial Pacific

    SciTech Connect

    Barber, R.T. ); Chavez, F.P. )

    1991-12-01

    Analysis of the Chl-specific rate of primary productivity (P{sup B}) as a function of subsurface nutrient concentration at >300 equatorial stations provides an answer to the question: What processes regulate primary productivity rate in the high-nutrient, low-chlorophyll waters of the equatorial Pacific In the western Pacific where there is a gradient in 60-m (NO{sub 3}) from 0 to {approximately}12 {mu}M, the productivity rate is a linear function of nutrient concentration; in the eastern Pacific where the gradient is from 12 to 28 {mu}M, the productivity rate is independent of nutrient concentration and limited to {approximately}36 mg C(mg Chl){sup {minus}1} d{sup {minus}1}, or a mean euphotic zone C-specific growth rate ({mu}) of 0.47 d{sup {minus}1}. However, rates downstream of the Galapagos Islands are not limited; they are 46.4 mg C(mg Chl){sup {minus}1} d{sup {minus}1} and {mu} = 0.57 d{sup {minus}1}, very close to the predicted nutrient-regulated rates in the absence of other limitation. This pattern of rate regulation can be accounted for by a combination of eolian Fe, subsurface nutrients, and sedimentary Fe derived from the Galapagos platform. In the low-nutrient western Pacific the eolian supply of Fe is adequate to allow productivity rate to be set by subsurface nutrient concentration. In the nutrient-rich easter equatorial region eolian Fe is inadequate to support productivity rates proportional to the higher nutrient concentrations, so in this region eolian Fe is rate limiting. Around the Galapagos Islands productivity rates reach levels consistent with nutrient concentrations; sedimentary Fe from the Galapagos platform seems adequate to support increased nutrient-regulated productivity rates in this region.

  14. External dose-rate conversion factors for calculation of dose to the public

    SciTech Connect

    Not Available

    1988-07-01

    This report presents a tabulation of dose-rate conversion factors for external exposure to photons and electrons emitted by radionuclides in the environment. This report was prepared in conjunction with criteria for limiting dose equivalents to members of the public from operations of the US Department of Energy (DOE). The dose-rate conversion factors are provided for use by the DOE and its contractors in performing calculations of external dose equivalents to members of the public. The dose-rate conversion factors for external exposure to photons and electrons presented in this report are based on a methodology developed at Oak Ridge National Laboratory. However, some adjustments of the previously documented methodology have been made in obtaining the dose-rate conversion factors in this report. 42 refs., 1 fig., 4 tabs.

  15. An approximate method for calculating heating rates on three-dimensional vehicles

    NASA Technical Reports Server (NTRS)

    Hamilton, H. H., II; Greene, Francis A.; Dejarnette, Fred R.

    1993-01-01

    An approximate method for calculating heating rates on three-dimensional vehicles at angle of attack is presented. The method is based on the axisymmetric analog for three-dimensional boundary layers and uses a generalized body fitted coordinate system. Edge conditions for the boundary layer solution are obtained from an inviscid flowfield solution, and because of the coordinate system used the method is applicable to any blunt body geometry for which a inviscid flowfield solution can be obtained. It is validated by comparing with experimental heating data and with Navier-Stokes calculations on the Shuttle orbiter at both wind tunnel and flight conditions and with Navier-Stokes calculations on the HL-20 at wind tunnel conditions.

  16. Approximate method for calculating heating rates on three-dimensional vehicles

    NASA Technical Reports Server (NTRS)

    Hamilton, H. Harris; Greene, Francis A.; Dejarnette, F. R.

    1994-01-01

    An approximate method for calculating heating rates on three-dimensional vehicles at angle of attack is presented. The method is based on the axisymmetric analog for three-dimensional boundary layers and uses a generalized body-fitted coordinate system. Edge conditions for the boundary-layer solution are obtained from an inviscid flowfield solution, and because of the coordinate system used, the method is applicable to any blunt body geometry for which an inviscid flowfield solution can be obtained. The method is validated by comparing with experimental heating data and with thin-layer Navier-Stokes calculations on the shuttle orbiter at both wind-tunnel and flight conditions and with thin-layer Navier-Stokes calculations on the HL-20 at wind-tunnel conditions.

  17. Diffusion Rates for Hydrogen on Pd(111) from Molecular Quantum Dynamics Calculations.

    PubMed

    Firmino, Thiago; Marquardt, Roberto; Gatti, Fabien; Dong, Wei

    2014-12-18

    The van Hove formula for the dynamical structure factor (DSF) related to particle scattering at mobile adsorbates is extended to include the relaxation of the adsorbates' vibrational states. The total rate obtained from the DSF is assumed to be the sum of a diffusion and a relaxation rate. A simple kinetic model to support this assumption is presented. To illustrate its potential applicability, the formula is evaluated using wave functions, energies, and lifetimes of vibrational states obtained for H/Pd(111) from first-principle calculations. Results show that quantum effects can be expected to be important even at room temperature.

  18. Assessments of fluid friction factors for use in leak rate calculations

    SciTech Connect

    Chivers, T.C.

    1997-04-01

    Leak before Break procedures require estimates of leakage, and these in turn need fluid friction to be assessed. In this paper available data on flow rates through idealized and real crack geometries are reviewed in terms of a single friction factor k It is shown that for {lambda} < 1 flow rates can be bounded using correlations in terms of surface R{sub a} values. For {lambda} > 1 the database is less precise, but {lambda} {approx} 4 is an upper bound, hence in this region flow calculations can be assessed using 1 < {lambda} < 4.

  19. A method for calculating strain energy release rate based on beam theory

    NASA Technical Reports Server (NTRS)

    Sun, C. T.; Pandey, R. K.

    1993-01-01

    The Timoshenko beam theory was used to model cracked beams and to calculate the total strain energy release rate. The root rotation of the beam segments at the crack tip were estimated based on an approximate 2D elasticity solution. By including the strain energy released due to the root rotations of the beams during crack extension, the strain energy release rate obtained using beam theory agrees very well with the 2D finite element solution. Numerical examples were given for various beam geometries and loading conditions. Comparisons with existing beam models were also given.

  20. Improved method for calculating strain energy release rate based on beam theory

    NASA Technical Reports Server (NTRS)

    Sun, C. T.; Pandey, R. K.

    1994-01-01

    The Timoshenko beam theory was used to model cracked beams and to calculate the total strain-energy release rate. The root rotations of the beam segments at the crack tip were estimated based on an approximate two-dimensional elasticity solution. By including the strain energy released due to the root rotations of the beams during crack extension, the strain-energy release rate obtained using beam theory agrees very well with the two-dimensional finite element solution. Numerical examples were given for various beam geometries and loading conditions. Comparisons with existing beam models were also given.

  1. An improvement in the calculation of the efficiency of oxidative phosphorylation and rate of energy dissipation in mitochondria

    NASA Astrophysics Data System (ADS)

    Ghafuri, Mohazabeh; Golfar, Bahareh; Nosrati, Mohsen; Hoseinkhani, Saman

    2014-12-01

    The process of ATP production is one of the most vital processes in living cells which happens with a high efficiency. Thermodynamic evaluation of this process and the factors involved in oxidative phosphorylation can provide a valuable guide for increasing the energy production efficiency in research and industry. Although energy transduction has been studied qualitatively in several researches, there are only few brief reviews based on mathematical models on this subject. In our previous work, we suggested a mathematical model for ATP production based on non-equilibrium thermodynamic principles. In the present study, based on the new discoveries on the respiratory chain of animal mitochondria, Golfar's model has been used to generate improved results for the efficiency of oxidative phosphorylation and the rate of energy loss. The results calculated from the modified coefficients for the proton pumps of the respiratory chain enzymes are closer to the experimental results and validate the model.

  2. Calculation of Decompression Rates for the Initial Explosive Phase of the 2010 Merapi Eruption

    NASA Astrophysics Data System (ADS)

    Matthews, E.; Genareau, K. D.

    2015-12-01

    The 2010 eruption of Merapi (Java, Indonesia) initiated with an uncharacteristic explosion, followed by rapid lava dome growth and collapse, all of which generated deadly pyroclastic density currents (PDCs). PDC samples from the initial explosion on October 26th were collected from several locations surrounding the edifice. Plagioclase phenocrysts represent the primary component of the dominant ash mode due to the elutriation of the finer ash fraction during PDC transport. Secondary electron images of 45 phenocrysts were taken using the scanning electron microscope (SEM) to examine preserved glass coatings on phenocrysts, which represent the interstitial melt within the magma at the point of fragmentation. Using these images, the bubble number densities (BNDs) were determined, and the decompression rate meter of Toramaru (2006) was used to calculate the decompression rate during the initial explosion of the 2010 Merapi eruption. Calculated decompression rates range from 6.08x10^7 Pa/s to 1.4x10^8 Pa/s. Decompression rates have shown to correlate with eruption column height; therefore Merapi's rates should be similar to those of other Vulcanian explosions, because the eruption column was 8-9 km in height. The decompression rates acquired for Merapi using Toramaru's BND meter are higher than the rates calculated with other methods such as microlite number density and extension cracks in crystals. Sakurajima volcano (Japan) experienced decompression rates from 7.0 × 10^3 to 7.8 × 10^4 Pa/s during the later phase of the fall 2011 Vulcanian explosions. Plinian explosions, such as at the 1991 eruption of Mt. Pinatubo and the 1980 eruption of St. Helens had much higher column heights compared to the initial 2010 Merapi explosion; 35 km, 19 km, and 8-9 km, respectively, but decompression rates in a comparative range (10^8 Pa/s). Higher decompression rates during the 2010 initial explosion at Merapi likely resulted from increased overpressure in the shallow conduit, the

  3. Java and Vector Graphics Tools for Element Production Calculations in Computational Astrophysics

    NASA Astrophysics Data System (ADS)

    Lingerfelt, Eric; McMahon, Erin; Hix, Raph; Guidry, Mike; Smith, Michael

    2002-08-01

    We are developing a set of extendable, cross-platform tools and interfaces using Java and vector technologies such as SVG and SWF to facilitate element production calculations in computational astrophysics. The Java technologies are customizable and portable, and can be utilized as a stand-alone application or distributed across a network. These tools, which can have a broad applications in general scientific visualization, are currently being used to explore and compare various reaction rates, set up and run explosive nucleosynthesis calculations, and visualize these results with compact, high quality vector graphics. The facilities for reading and plotting nuclear reaction rates and their components from a network or library permit the user to include new rates and adjust current ones. Setup and initialization of a nucleosynthesis calculation is through an intuitive graphical interface. Sophisticated visualization and graphical analysis tools offer the ability to view results in an interactive, scalable vector graphics format, which leads to a dramatic reduction in visualization file sizes while maintaining high visual quality and interactive control. The use of these tools for other applications will also be mentioned.

  4. Simple strategies for inclusion of Voigt effects in infrared cooling rate calculations.

    PubMed

    Fels, S B

    1979-08-01

    A line shape with rectangular core and nu(-2) wings is shown to be an excellent alias for the Voigt profile when calculating equivalent widths. It leads to closed analytic forms in the commonly employed random models and gives highly accurate ozone cooling rates. An even simpler device for applications where less accurate results are required involves use of the Lorentz profile with a width which does not vanish at zero pressure. PMID:20212722

  5. Effects of Sample Size on Estimates of Population Growth Rates Calculated with Matrix Models

    PubMed Central

    Fiske, Ian J.; Bruna, Emilio M.; Bolker, Benjamin M.

    2008-01-01

    Background Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (λ) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of λ–Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of λ due to increased sampling variance. We investigated if sampling variability and the distribution of sampling effort among size classes lead to biases in estimates of λ. Methodology/Principal Findings Using data from a long-term field study of plant demography, we simulated the effects of sampling variance by drawing vital rates and calculating λ for increasingly larger populations drawn from a total population of 3842 plants. We then compared these estimates of λ with those based on the entire population and calculated the resulting bias. Finally, we conducted a review of the literature to determine the sample sizes typically used when parameterizing matrix models used to study plant demography. Conclusions/Significance We found significant bias at small sample sizes when survival was low (survival = 0.5), and that sampling with a more-realistic inverse J-shaped population structure exacerbated this bias. However our simulations also demonstrate that these biases rapidly become negligible with increasing sample sizes or as survival increases. For many of the sample sizes used in demographic studies, matrix models are probably robust to the biases resulting from sampling variance of vital rates. However, this conclusion may depend on the structure of populations or the distribution of sampling effort in ways that are unexplored. We suggest more intensive sampling of populations when individual survival is low and greater sampling of stages with high elasticities. PMID:18769483

  6. Comparison of measured and calculated dose rates for the Castor HAW 20/28 CG.

    PubMed

    Ringleb, O; Kühl, H; Scheib, H; Rimpler, A

    2005-01-01

    In January 2003 neutron and gamma dose rate measurements at a CASTOR HAW 20/28 CG were performed by the Bundesamt für Strahlenschutz at Gorleben. First, commercial dose rate measurement devices were used, then spectral measurements with a Bonner sphere system were made to verify the results. Axial and circumferential dose rate profiles were measured near the cask surface and spectral measurements were performed for some locations. A shielding analysis of the cask was performed with the MCNP Monte Carlo Code with ENDF/B-VI cross section libraries. The cask was modelled 'as built', i.e. with its real inventory, dimensions and material densities and with the same configuration and position as in the storage facility. The average C/E-ratios are 1.3 for neutron dose rates and 1.4 for gamma dose rates. Both the measured and calculated dose rates show the same qualitative trends in the axial and circumferential direction. The spectral measurements show a variation in the spectra across the cask surface. This correlates with the variation found in the C/E-ratios. At cask midheight good agreement between the Bonner sphere system and the commercial device (LB 6411) is found with a 7% lower derived H*(10) dose rate from the Bonner sphere system. PMID:16604722

  7. Calculators, Graphs, Gestures and the Production of Meaning

    ERIC Educational Resources Information Center

    Radford, Luis; Demers, Serge; Guzman, Jose; Cerulli, Michele

    2003-01-01

    In this paper we report an analysis of a teaching sequence in which Grade 11 students were asked to produce some graphs corresponding to the relationship between time and distance of a cylinder moving up and down an inclined plane. The students were also asked to carry out the experience using a TI 83+ graphic calculator equipped with a sensor,…

  8. Reduced Equations for Calculating the Combustion Rates of Jet-A and Methane Fuel

    NASA Technical Reports Server (NTRS)

    Molnar, Melissa; Marek, C. John

    2003-01-01

    Simplified kinetic schemes for Jet-A and methane fuels were developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) that is being developed at Glenn. These kinetic schemes presented here result in a correlation that gives the chemical kinetic time as a function of initial overall cell fuel/air ratio, pressure, and temperature. The correlations would then be used with the turbulent mixing times to determine the limiting properties and progress of the reaction. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentration of carbon monoxide as a function of fuel air ratio, pressure, and temperature. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates and the values obtained from the equilibrium correlations were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide, and NOx were obtained for both Jet-A fuel and methane.

  9. Finite Volume Numerical Methods for Aeroheating Rate Calculations from Infrared Thermographic Data

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Berry, Scott A.; Horvath, Thomas J.; Nowak, Robert J.

    2003-01-01

    The use of multi-dimensional finite volume numerical techniques with finite thickness models for calculating aeroheating rates from measured global surface temperatures on hypersonic wind tunnel models was investigated. Both direct and inverse finite volume techniques were investigated and compared with the one-dimensional semi -infinite technique. Global transient surface temperatures were measured using an infrared thermographic technique on a 0.333-scale model of the Hyper-X forebody in the Langley Research Center 20-Inch Mach 6 Air tunnel. In these tests the effectiveness of vortices generated via gas injection for initiating hypersonic transition on the Hyper-X forebody were investigated. An array of streamwise orientated heating striations were generated and visualized downstream of the gas injection sites. In regions without significant spatial temperature gradients, one-dimensional techniques provided accurate aeroheating rates. In regions with sharp temperature gradients due to the striation patterns two-dimensional heat transfer techniques were necessary to obtain accurate heating rates. The use of the one-dimensional technique resulted in differences of 20% in the calculated heating rates because it did not account for lateral heat conduction in the model.

  10. Finite Volume Numerical Methods for Aeroheating Rate Calculations from Infrared Thermographic Data

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Berry, Scott A.; Horvath, Thomas J.; Nowak, Robert J.

    2006-01-01

    The use of multi-dimensional finite volume heat conduction techniques for calculating aeroheating rates from measured global surface temperatures on hypersonic wind tunnel models was investigated. Both direct and inverse finite volume techniques were investigated and compared with the standard one-dimensional semi-infinite technique. Global transient surface temperatures were measured using an infrared thermographic technique on a 0.333-scale model of the Hyper-X forebody in the NASA Langley Research Center 20-Inch Mach 6 Air tunnel. In these tests the effectiveness of vortices generated via gas injection for initiating hypersonic transition on the Hyper-X forebody was investigated. An array of streamwise-orientated heating striations was generated and visualized downstream of the gas injection sites. In regions without significant spatial temperature gradients, one-dimensional techniques provided accurate aeroheating rates. In regions with sharp temperature gradients caused by striation patterns multi-dimensional heat transfer techniques were necessary to obtain more accurate heating rates. The use of the one-dimensional technique resulted in differences of 20% in the calculated heating rates compared to 2-D analysis because it did not account for lateral heat conduction in the model.

  11. Effect of photochemical models on calculated equilibria and cooling rates in the stratosphere

    NASA Technical Reports Server (NTRS)

    Blake, D.; Lindzen, R. S.

    1973-01-01

    The determination of the relaxation time of a temperature perturbation in the stratosphere must take into account the effects of the absorption of solar energy by ozone, while the ozone density itself is dependent on temperature. A photochemical model, consisting of continuity equations for each of 29 constituents with reaction rates and adjustment times, is used to obtain the vertical distribution of ozone. The altitude range from 35 to 60 km in non-Arctic regions is shown to be in approximate joint radiative-photochemical equilibrium. The temperature and ozone distributions are thus well buffered. Modest changes in ozone and temperature were calculated on the basis of this model from large changes in cooling rates and reaction rates, and the results are shown to be more in line with actual observations. The importance of estimating the mixing ratios for NO and H2O is emphasized.

  12. Quantum three-body calculation of nonresonant triple-alpha reaction rate at low temperatures

    SciTech Connect

    Ogata, Kazuyuki; Kan, Masataka; Kamimura, Masayasu

    2010-06-01

    Triple-alpha reaction rate is re-evaluated by directly solving the three-body Schroedinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. An accurate description of the alpha-alpha nonresonant states significantly quenches the Coulomb barrier between the first two alpha-particles and the third alpha-particle. Consequently, the alpha-alpha nonresonant continuum states give a markedly larger contribution at low temperatures than that reported in previous studies. We show that Nomoto's method for three-body nonresonant capture processes, which is adopted in the NACRE compilation and many other studies, is a crude approximation of the accurate quantum three-body model calculation. We find an increase in triple-alpha reaction rate by 26 orders of magnitude around 10{sup 7} K compared with the rate of NACRE.

  13. Quantum three-body calculation of nonresonant triple-{alpha} reaction rate at low temperatures

    SciTech Connect

    Ogata, Kazuyuki; Kan, Masataka; Kamimura, Masayasu

    2010-08-12

    Triple-{alpha} reaction rate is re-evaluated by directly solving the three-body Schroedinger equation. The resonant and nonresonant processes are treated on the same footing using the continuum-discretized coupled-channels method for three-body scattering. An accurate description of the {alpha}-{alpha} nonresonant states significantly quenches the Coulomb barrier between the first two {alpha}-particles and the third {alpha}-particle. Consequently, the{alpha}-{alpha} nonresonant continuum states give a markedly larger contribution at low temperatures than that reported in previous studies. We show that Nomoto's method for three-body nonresonant capture processes, which is adopted in the NACRE compilation and many other studies, is a crude approximation of the accurate quantum three-body model calculation. We find an increase in triple-{alpha} reaction rate by about 20 orders of magnitude around 10{sup 7} K compared with the rate of NACRE.

  14. Calculating inspector probability of detection using performance demonstration program pass rates

    NASA Astrophysics Data System (ADS)

    Cumblidge, Stephen; D'Agostino, Amy

    2016-02-01

    The United States Nuclear Regulatory Commission (NRC) staff has been working since the 1970's to ensure that nondestructive testing performed on nuclear power plants in the United States will provide reasonable assurance of structural integrity of the nuclear power plant components. One tool used by the NRC has been the development and implementation of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section XI Appendix VIII[1] (Appendix VIII) blind testing requirements for ultrasonic procedures, equipment, and personnel. Some concerns have been raised, over the years, by the relatively low pass rates for the Appendix VIII qualification testing. The NRC staff has applied statistical tools and simulations to determine the expected probability of detection (POD) for ultrasonic examinations under ideal conditions based on the pass rates for the Appendix VIII qualification tests for the ultrasonic testing personnel. This work was primarily performed to answer three questions. First, given a test design and pass rate, what is the expected overall POD for inspectors? Second, can we calculate the probability of detection for flaws of different sizes using this information? Finally, if a previously qualified inspector fails a requalification test, does this call their earlier inspections into question? The calculations have shown that one can expect good performance from inspectors who have passed appendix VIII testing in a laboratory-like environment, and the requalification pass rates show that the inspectors have maintained their skills between tests. While these calculations showed that the PODs for the ultrasonic inspections are very good under laboratory conditions, the field inspections are conducted in a very different environment. The NRC staff has initiated a project to systematically analyze the human factors differences between qualification testing and field examinations. This work will be used to evaluate and prioritize

  15. Evaluating range-expansion models for calculating nonnative species' expansion rate.

    PubMed

    Preuss, Sonja; Low, Matthew; Cassel-Lundhagen, Anna; Berggren, Asa

    2014-07-01

    Species range shifts associated with environmental change or biological invasions are increasingly important study areas. However, quantifying range expansion rates may be heavily influenced by methodology and/or sampling bias. We compared expansion rate estimates of Roesel's bush-cricket (Metrioptera roeselii, Hagenbach 1822), a nonnative species currently expanding its range in south-central Sweden, from range statistic models based on distance measures (mean, median, 95(th) gamma quantile, marginal mean, maximum, and conditional maximum) and an area-based method (grid occupancy). We used sampling simulations to determine the sensitivity of the different methods to incomplete sampling across the species' range. For periods when we had comprehensive survey data, range expansion estimates clustered into two groups: (1) those calculated from range margin statistics (gamma, marginal mean, maximum, and conditional maximum: ˜3 km/year), and (2) those calculated from the central tendency (mean and median) and the area-based method of grid occupancy (˜1.5 km/year). Range statistic measures differed greatly in their sensitivity to sampling effort; the proportion of sampling required to achieve an estimate within 10% of the true value ranged from 0.17 to 0.9. Grid occupancy and median were most sensitive to sampling effort, and the maximum and gamma quantile the least. If periods with incomplete sampling were included in the range expansion calculations, this generally lowered the estimates (range 16-72%), with exception of the gamma quantile that was slightly higher (6%). Care should be taken when interpreting rate expansion estimates from data sampled from only a fraction of the full distribution. Methods based on the central tendency will give rates approximately half that of methods based on the range margin. The gamma quantile method appears to be the most robust to incomplete sampling bias and should be considered as the method of choice when sampling the entire

  16. Evaluating range-expansion models for calculating nonnative species' expansion rate

    PubMed Central

    Preuss, Sonja; Low, Matthew; Cassel-Lundhagen, Anna; Berggren, Åsa

    2014-01-01

    Species range shifts associated with environmental change or biological invasions are increasingly important study areas. However, quantifying range expansion rates may be heavily influenced by methodology and/or sampling bias. We compared expansion rate estimates of Roesel's bush-cricket (Metrioptera roeselii, Hagenbach 1822), a nonnative species currently expanding its range in south-central Sweden, from range statistic models based on distance measures (mean, median, 95th gamma quantile, marginal mean, maximum, and conditional maximum) and an area-based method (grid occupancy). We used sampling simulations to determine the sensitivity of the different methods to incomplete sampling across the species' range. For periods when we had comprehensive survey data, range expansion estimates clustered into two groups: (1) those calculated from range margin statistics (gamma, marginal mean, maximum, and conditional maximum: ˜3 km/year), and (2) those calculated from the central tendency (mean and median) and the area-based method of grid occupancy (˜1.5 km/year). Range statistic measures differed greatly in their sensitivity to sampling effort; the proportion of sampling required to achieve an estimate within 10% of the true value ranged from 0.17 to 0.9. Grid occupancy and median were most sensitive to sampling effort, and the maximum and gamma quantile the least. If periods with incomplete sampling were included in the range expansion calculations, this generally lowered the estimates (range 16–72%), with exception of the gamma quantile that was slightly higher (6%). Care should be taken when interpreting rate expansion estimates from data sampled from only a fraction of the full distribution. Methods based on the central tendency will give rates approximately half that of methods based on the range margin. The gamma quantile method appears to be the most robust to incomplete sampling bias and should be considered as the method of choice when sampling the entire

  17. Isotope Production Facility Conceptual Thermal-Hydraulic Design Review and Scoping Calculations

    SciTech Connect

    Pasamehmetoglu, K.O.; Shelton, J.D.

    1998-08-01

    The thermal-hydraulic design of the target for the Isotope Production Facility (IPF) is reviewed. In support of the technical review, scoping calculations are performed. The results of the review and scoping calculations are presented in this report.

  18. New reaction rates for improved primordial D /H calculation and the cosmic evolution of deuterium

    NASA Astrophysics Data System (ADS)

    Coc, Alain; Petitjean, Patrick; Uzan, Jean-Philippe; Vangioni, Elisabeth; Descouvemont, Pierre; Iliadis, Christian; Longland, Richard

    2015-12-01

    Primordial or big bang nucleosynthesis (BBN) is one of the three historically strong evidences for the big bang model. Standard BBN is now a parameter-free theory, since the baryonic density of the Universe has been deduced with an unprecedented precision from observations of the anisotropies of the cosmic microwave background radiation. There is a good agreement between the primordial abundances of 4He, D, 3He, and 7Li deduced from observations and from primordial nucleosynthesis calculations. However, the 7Li calculated abundance is significantly higher than the one deduced from spectroscopic observations and remains an open problem. In addition, recent deuterium observations have drastically reduced the uncertainty on D /H , to reach a value of 1.6%. It needs to be matched by BBN predictions whose precision is now limited by thermonuclear reaction rate uncertainties. This is especially important as many attempts to reconcile Li observations with models lead to an increased D prediction. Here, we reevaluate the d (p ,γ )3He, d (d ,n ) 3H3, and d (d ,p ) 3H reaction rates that govern deuterium destruction, incorporating new experimental data and carefully accounting for systematic uncertainties. Contrary to previous evaluations, we use theoretical ab initio models for the energy dependence of the S factors. As a result, these rates increase at BBN temperatures, leading to a reduced value of D /H =(2.45 ±0.10 )×10-5 (2 σ ), in agreement with observations.

  19. Benchmarking of MCNP for calculating dose rates at an interim storage facility for nuclear waste.

    PubMed

    Heuel-Fabianek, Burkhard; Hille, Ralf

    2005-01-01

    During the operation of research facilities at Research Centre Jülich, Germany, nuclear waste is stored in drums and other vessels in an interim storage building on-site, which has a concrete shielding at the side walls. Owing to the lack of a well-defined source, measured gamma spectra were unfolded to determine the photon flux on the surface of the containers. The dose rate simulation, including the effects of skyshine, using the Monte Carlo transport code MCNP is compared with the measured dosimetric data at some locations in the vicinity of the interim storage building. The MCNP data for direct radiation confirm the data calculated using a point-kernel method. However, a comparison of the modelled dose rates for direct radiation and skyshine with the measured data demonstrate the need for a more precise definition of the source. Both the measured and the modelled dose rates verified the fact that the legal limits (<1 mSv a(-1)) are met in the area outside the perimeter fence of the storage building to which members of the public have access. Using container surface data (gamma spectra) to define the source may be a useful tool for practical calculations and additionally for benchmarking of computer codes if the discussed critical aspects with respect to the source can be addressed adequately. PMID:16381760

  20. Monte-Carlo calculations of particle fluences and neutron effective dose rates in the atmosphere.

    PubMed

    Matthiä, Daniel; Sihver, Lembit; Meier, Matthias

    2008-01-01

    Monitoring of radiation exposure of aircrew is a legal requirement for many airlines in the EU and a challenging task in dosimetry. Monte-Carlo simulations of cosmic particles in the atmosphere can contribute to the understanding of the corresponding radiation field. Calculations of secondary neutron fluences in the atmosphere produced by galactic cosmic rays together with the resulting neutron-effective dose rates are shown in this paper and compared with results from the AIR project. The PLANETOCOSMICS package based on GEANT4 and two models for the local interstellar spectra of galactic cosmic rays have been used for the calculations. Furthermore, secondary muon fluences have been computed and are compared with CAPRICE measurements.

  1. 30 CFR 1206.352 - How do I calculate the royalty due on geothermal resources used for commercial production or...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in your lease; or (2) The royalty rate that BLM prescribes or calculates under 43 CFR 3211.17. See... CFR 3211.17. See § 1206.361 for additional provisions applicable to determining gross proceeds under... geothermal resources used for commercial production or generation of electricity? 1206.352 Section...

  2. Atomic hydrogen production rates for comet P/Halley from observations with Dynamics Explorer I

    NASA Technical Reports Server (NTRS)

    Craven, J. D.; Frank, L. A.

    1987-01-01

    Newly analyzed observations of the Dynamics Explorer I (DE1), launched on August 3, 1981, were used to determine the hydrogen production rate for Comet Halley at heliocentric distances, r, less than about 1.5 AU from measurements of the total Lyman-alpha flux at earth due to the cometary neutral hydrogen distribution. The production rates, determined as a function of r, were found to be consistent with in situ measurements from the Giotto and Vega spacecraft. The calculated rates are also consistent with remote observations using two sounding rockets and with the Pioneer-Venus and IUE spacecraft.

  3. Steady State Flammable Gas Release Rate Calculation & Lower Flammability Level Evaluation for Hanford Tank Waste [SEC 1 & 2

    SciTech Connect

    HU, T.A.

    2002-06-20

    Assess the steady state level at normal & off-normal ventilation conditions. Hydrogen generation rate calculated for 177 tanks using rate equation model. Flammability calc. based on hydrogen, ammonia, & methane proformed for tanks at various scenarios.

  4. Calculation of energy relaxation rates of fast particles by phonons in crystals

    NASA Astrophysics Data System (ADS)

    Prange, Micah; Campbell, Luke; Wu, Dangxin; Kerisit, Sebastien

    2015-03-01

    We present ab initio calculations of the temperature-dependent exchange of energy between a classical charged point-particle and the phonons of a crystalline material. The phonons, which are computed using density functional perturbation theory (DFPT) methods, interact with the moving particle via the Coulomb interaction between the density induced in the material by phonon excitation and the charge of the classical particle. Energy relaxation rates are computed using time-dependent perturbation theory. The method, which is applicable wherever DFPT is, is illustrated with results for several important scintillators whose performance is affected by electron thermalization. We discuss the influence of the form assumed for quasiparticle dispersion on theoretical estimates of electron cooling rates. This research was supported by the National Nuclear Security Administration, Office of DNN R&D, of the DOE. PNNL is operated by Battelle Memorial Institute under Contract DE-AC0576RL01830.

  5. Calculation of energy relaxation rates of fast particles by phonons in crystals

    SciTech Connect

    Prange, Micah P.; Campbell, Luke W.; Wu, Dangxin; Gao, Fei; Kerisit, Sebastien N.

    2015-03-01

    We present ab initio calculations of the temperature-dependent exchange of energy between a classical charged point-particle and the phonons of a crystalline material. The phonons, which are computed using density functional perturbation theory (DFPT) methods, interact with the mov- ing particle via the Coulomb interaction between the density induced in the material by phonon excitation and the charge of the classical particle. Energy relaxation rates are computed using time- dependent perturbation theory. The method, which is applicable wherever DFPT is, is illustrated with results for CsI, an important scintillator whose performance is affected by electron thermal- ization. We discuss the influence of the form assumed for quasiparticle dispersion on theoretical estimates of electron cooling rates.

  6. Maximizing production rates of the Linde Hampson machine

    NASA Astrophysics Data System (ADS)

    Maytal, B.-Z.

    2006-01-01

    In contrast to the ideal case of unlimited size recuperator, any real Linde-Hampson machine of finite size recuperator can be optimized to reach the extreme rates of performance. The group of cryocoolers sharing the same size recuperator is optimized in a closed form by determining the corresponding flow rate which maximizes its rate of cold production. For a similar group of liquefiers an optimal flow rate is derived to maximize the rate of production of liquid cryogen. The group of cryocoolers sharing a constant and given flow rate is optimized by shortening the recuperator for reaching a maximum compactness measured by the cooling power per unit size of the recuperator. The optimum conditions are developed for nitrogen and argon. The relevance of this analysis is discussed in the context of practice of fast cooldown Joule-Thomson cryocooling.

  7. Exergy and Its Efficiency Calculations in Ferrochrome Production

    NASA Astrophysics Data System (ADS)

    Ramakrishna, G.; Kadrolkar, Ameya; Srikakulapu, N. Gurulaxmi

    2015-04-01

    Ferrochrome production is a high energy intensive process consuming around 3000 to 3500 kWh/t of electrical energy. Ferrochrome is produced by smelting of different grades of chromite ore with coke and fluxing agents such as lime, dolomite, and quartz in a submerged arc furnace (SAF). Apart from the production of ferrochrome, co-products that are produced during the process include carbon monoxide rich off-gas and slag. The slag is cooled with high pressure jet water which results in the formation of slag granules. In the present practice, off-gas generated from the SAF is used for ladle preheating, as fuel in sinter plant, while the remaining is unutilized. Approximately 34 to 40 pct of heat from off-gas is utilized, while the remaining 60 to 66 pct of the off-gas can be utilized for generating electricity by gas combustion turbine. The concept of exergy is applied to monitor the existing process and to understand the feasibility of modification. In the present study, comparison of exergy efficiency for existing process and two adapted case studies has been performed, involving utilization of off-gas for sintering and power generation and waste heat utilization from dry slag granulation. It is observed that there was considerable increase in exergy efficiency for waste heat utilization by dry granulation case study when compared with other two case studies.

  8. Calculating lens dose and surface dose rates from 90Sr ophthalmic applicators using Monte Carlo modeling.

    PubMed

    Gleckler, M; Valentine, J D; Silberstein, E B

    1998-01-01

    Using a 90Sr applicator for brachytherapy for the reduction of recurrence rates after pterygium excisions has been an effective therapeutic procedure. Accurate knowledge of the dose being applied to the affected area on the sclera has been lacking, and for decades inaccurate estimates for lens dose have thus been made. Small errors in the assumptions which are required to make these estimates lead to dose rates changing exponentially because of the attenuation of beta particles. Monte Carlo simulations have been used to evaluate the assumptions that are now being used for the calculation of the surface dose rate and the corresponding determination of lens dose. For an ideal 90Sr applicator, results from this study indicate dose rates to the most radiosensitive areas of the lens ranging from 8.8 to 15.5 cGy/s. This range is based on different eye dimensions that ultimately corresponds to a range in distance between the applicator surface and the germinative epithelium of the lens of 2-3 mm. Furthermore, the conventional 200 cGy threshold for whole lens cataractogenesis is questioned for predicting complications from scleral brachytherapy. The dose to the germinative epithelium should be used for studying radiocataractogenesis.

  9. Comparison of measured and calculated dose rates near nuclear medicine patients.

    PubMed

    Yi, Y; Stabin, M G; McKaskle, M H; Shone, M D; Johnson, A B

    2013-08-01

    Widely used release criteria for patients receiving radiopharmaceuticals (NUREG-1556, Vol. 9, Rev.1, Appendix U) are known to be overly conservative. The authors measured external exposure rates near patients treated with I, Tc, and F and compared the measurements to calculated values using point and line source models. The external exposure dose rates for 231, 11, and 52 patients scanned or treated with I, Tc, and F, respectively, were measured at 0.3 m and 1.0 m shortly after radiopharmaceutical administration. Calculated values were always higher than measured values and suggested the application of "self-shielding factors," as suggested by Siegel et al. in 2002. The self-shielding factors of point and line source models for I at 1 m were 0.60 ± 0.16 and 0.73 ± 0.20, respectively. For Tc patients, the self-shielding factors for point and line source models were 0.44 ± 0.19 and 0.55 ± 0.23, and the values were 0.50 ± 0.09 and 0.60 ± 0.12, respectively, for F (all FDG) patients. Treating patients as unshielded point sources of radiation is clearly inappropriate. In reality, they are volume sources, but treatment of their exposures using a line source model with appropriate self-shielding factors produces a more realistic, but still conservative, approach for managing patient release.

  10. Direct calculation of ice homogeneous nucleation rate for a molecular model of water.

    PubMed

    Haji-Akbari, Amir; Debenedetti, Pablo G

    2015-08-25

    Ice formation is ubiquitous in nature, with important consequences in a variety of environments, including biological cells, soil, aircraft, transportation infrastructure, and atmospheric clouds. However, its intrinsic kinetics and microscopic mechanism are difficult to discern with current experiments. Molecular simulations of ice nucleation are also challenging, and direct rate calculations have only been performed for coarse-grained models of water. For molecular models, only indirect estimates have been obtained, e.g., by assuming the validity of classical nucleation theory. We use a path sampling approach to perform, to our knowledge, the first direct rate calculation of homogeneous nucleation of ice in a molecular model of water. We use TIP4P/Ice, the most accurate among existing molecular models for studying ice polymorphs. By using a novel topological approach to distinguish different polymorphs, we are able to identify a freezing mechanism that involves a competition between cubic and hexagonal ice in the early stages of nucleation. In this competition, the cubic polymorph takes over because the addition of new topological structural motifs consistent with cubic ice leads to the formation of more compact crystallites. This is not true for topological hexagonal motifs, which give rise to elongated crystallites that are not able to grow. This leads to transition states that are rich in cubic ice, and not the thermodynamically stable hexagonal polymorph. This mechanism provides a molecular explanation for the earlier experimental and computational observations of the preference for cubic ice in the literature.

  11. Comparison of measured and calculated dose rates near nuclear medicine patients.

    PubMed

    Yi, Y; Stabin, M G; McKaskle, M H; Shone, M D; Johnson, A B

    2013-08-01

    Widely used release criteria for patients receiving radiopharmaceuticals (NUREG-1556, Vol. 9, Rev.1, Appendix U) are known to be overly conservative. The authors measured external exposure rates near patients treated with I, Tc, and F and compared the measurements to calculated values using point and line source models. The external exposure dose rates for 231, 11, and 52 patients scanned or treated with I, Tc, and F, respectively, were measured at 0.3 m and 1.0 m shortly after radiopharmaceutical administration. Calculated values were always higher than measured values and suggested the application of "self-shielding factors," as suggested by Siegel et al. in 2002. The self-shielding factors of point and line source models for I at 1 m were 0.60 ± 0.16 and 0.73 ± 0.20, respectively. For Tc patients, the self-shielding factors for point and line source models were 0.44 ± 0.19 and 0.55 ± 0.23, and the values were 0.50 ± 0.09 and 0.60 ± 0.12, respectively, for F (all FDG) patients. Treating patients as unshielded point sources of radiation is clearly inappropriate. In reality, they are volume sources, but treatment of their exposures using a line source model with appropriate self-shielding factors produces a more realistic, but still conservative, approach for managing patient release. PMID:23799503

  12. Direct calculation of ice homogeneous nucleation rate for a molecular model of water

    PubMed Central

    Haji-Akbari, Amir; Debenedetti, Pablo G.

    2015-01-01

    Ice formation is ubiquitous in nature, with important consequences in a variety of environments, including biological cells, soil, aircraft, transportation infrastructure, and atmospheric clouds. However, its intrinsic kinetics and microscopic mechanism are difficult to discern with current experiments. Molecular simulations of ice nucleation are also challenging, and direct rate calculations have only been performed for coarse-grained models of water. For molecular models, only indirect estimates have been obtained, e.g., by assuming the validity of classical nucleation theory. We use a path sampling approach to perform, to our knowledge, the first direct rate calculation of homogeneous nucleation of ice in a molecular model of water. We use TIP4P/Ice, the most accurate among existing molecular models for studying ice polymorphs. By using a novel topological approach to distinguish different polymorphs, we are able to identify a freezing mechanism that involves a competition between cubic and hexagonal ice in the early stages of nucleation. In this competition, the cubic polymorph takes over because the addition of new topological structural motifs consistent with cubic ice leads to the formation of more compact crystallites. This is not true for topological hexagonal motifs, which give rise to elongated crystallites that are not able to grow. This leads to transition states that are rich in cubic ice, and not the thermodynamically stable hexagonal polymorph. This mechanism provides a molecular explanation for the earlier experimental and computational observations of the preference for cubic ice in the literature. PMID:26240318

  13. Direct calculation of ice homogeneous nucleation rate for a molecular model of water.

    PubMed

    Haji-Akbari, Amir; Debenedetti, Pablo G

    2015-08-25

    Ice formation is ubiquitous in nature, with important consequences in a variety of environments, including biological cells, soil, aircraft, transportation infrastructure, and atmospheric clouds. However, its intrinsic kinetics and microscopic mechanism are difficult to discern with current experiments. Molecular simulations of ice nucleation are also challenging, and direct rate calculations have only been performed for coarse-grained models of water. For molecular models, only indirect estimates have been obtained, e.g., by assuming the validity of classical nucleation theory. We use a path sampling approach to perform, to our knowledge, the first direct rate calculation of homogeneous nucleation of ice in a molecular model of water. We use TIP4P/Ice, the most accurate among existing molecular models for studying ice polymorphs. By using a novel topological approach to distinguish different polymorphs, we are able to identify a freezing mechanism that involves a competition between cubic and hexagonal ice in the early stages of nucleation. In this competition, the cubic polymorph takes over because the addition of new topological structural motifs consistent with cubic ice leads to the formation of more compact crystallites. This is not true for topological hexagonal motifs, which give rise to elongated crystallites that are not able to grow. This leads to transition states that are rich in cubic ice, and not the thermodynamically stable hexagonal polymorph. This mechanism provides a molecular explanation for the earlier experimental and computational observations of the preference for cubic ice in the literature. PMID:26240318

  14. Direct Calculation of the Rate of Homogeneous Ice Nucleation for a Molecular Model of Water

    NASA Astrophysics Data System (ADS)

    Haji-Akbari, Amir; Debenedetti, Pablo

    Ice formation is ubiquitous in nature, with important consequences in many systems and environments. However, its intrinsic kinetics and mechanism are difficult to discern with experiments. Molecular simulations of ice nucleation are also challenging due to sluggish structural relaxation and the large nucleation barriers, and direct calculations of homogeneous nucleation rates have only been achieved for mW, a monoatomic coarse-grained model of water. For the more realistic molecular models, only indirect estimates have been obtained by assuming the validity of classical nucleation theory. Here, we use a coarse-grained variant of a path sampling approach known as forward-flux sampling to perform the first direct calculation of the homogeneous nucleation rate for TIP4P/Ice, which is the most accurate water model for studying ice polymorphs. By using a novel topological order parameter, we are able to identify a freezing mechanism that involves a competition between cubic and hexagonal ice polymorphs. In this competition, cubic ice wins as its growth leads to more compact crystallites

  15. Heart rate calculation from ensemble brain wave using wavelet and Teager-Kaiser energy operator.

    PubMed

    Srinivasan, Jayaraman; Adithya, V

    2015-01-01

    Electroencephalogram (EEG) signal artifacts are caused by various factors, such as, Electro-oculogram (EOG), Electromyogram (EMG), Electrocardiogram (ECG), movement artifact and line interference. The relatively high electrical energy cardiac activity causes EEG artifacts. In EEG signal processing the general approach is to remove the ECG signal. In this paper, we introduce an automated method to extract the ECG signal from EEG using wavelet and Teager-Kaiser energy operator for R-peak enhancement and detection. From the detected R-peaks the heart rate (HR) is calculated for clinical diagnosis. To check the efficiency of our method, we compare the HR calculated from ECG signal recorded in synchronous with EEG. The proposed method yields a mean error of 1.4% for the heart rate and 1.7% for mean R-R interval. The result illustrates that, proposed method can be used for ECG extraction from single channel EEG and used in clinical diagnosis like estimation for stress analysis, fatigue, and sleep stages classification studies as a multi-model system. In addition, this method eliminates the dependence of additional synchronous ECG in extraction of ECG from EEG signal process. PMID:26737640

  16. Heart rate calculation from ensemble brain wave using wavelet and Teager-Kaiser energy operator.

    PubMed

    Srinivasan, Jayaraman; Adithya, V

    2015-01-01

    Electroencephalogram (EEG) signal artifacts are caused by various factors, such as, Electro-oculogram (EOG), Electromyogram (EMG), Electrocardiogram (ECG), movement artifact and line interference. The relatively high electrical energy cardiac activity causes EEG artifacts. In EEG signal processing the general approach is to remove the ECG signal. In this paper, we introduce an automated method to extract the ECG signal from EEG using wavelet and Teager-Kaiser energy operator for R-peak enhancement and detection. From the detected R-peaks the heart rate (HR) is calculated for clinical diagnosis. To check the efficiency of our method, we compare the HR calculated from ECG signal recorded in synchronous with EEG. The proposed method yields a mean error of 1.4% for the heart rate and 1.7% for mean R-R interval. The result illustrates that, proposed method can be used for ECG extraction from single channel EEG and used in clinical diagnosis like estimation for stress analysis, fatigue, and sleep stages classification studies as a multi-model system. In addition, this method eliminates the dependence of additional synchronous ECG in extraction of ECG from EEG signal process.

  17. In vitro O 2 fluxes compared with 14C production and other rate terms during the JGOFS Equatorial Pacific experiment

    NASA Astrophysics Data System (ADS)

    Bender, Michael; Orchardo, Joe; Dickson, Mary-Lynn; Barber, Richard; Lindley, Steven

    1999-04-01

    We report rates of gross and net O 2 production measured in vitro during JGOFS cruises in the equatorial Pacific in spring and fall, 1992. We scale O 2 productivities to net and gross C production. We then compare the calculated rates with 14C production and with new/export production measured by various techniques. 14C productivities in samples incubated for 24 h are about 45% of gross carbon production rates calculated from gross O 2 production. The difference is compatible with expected rates of the Mehler reaction, photorespiration, excretion, and community mitochondrial respiration. 14C production rates are similar to net carbon production rates in the upper half of the euphotic zone. At lower irradiances, where net C production can be zero or less, 14C productivities lie between net community production and gross primary production. Net carbon production rates in vitro are a factor of =4-20 times greater than estimates from drifting sediment trap and tracer transport studies. This difference probably reflects anomalous accumulation of POC in bottles because of the exclusion of grazers.

  18. Metabolic clearance and production rates of human growth hormone.

    PubMed

    Taylor, A L; Finster, J L; Mintz, D H

    1969-12-01

    The metabolic clearance rate (MCR) of human growth hormone (HGH) was determined by the constant infusion to equilibrium technique utilizing HGH-(125)I. 22 control subjects had a MCR of 229 +/-52 ml/min (mean +/-SD). No difference was evident between sexes, or between various age groups. Patients with acromegaly demonstrated normal MCR's. Moreover, acute elevations of plasma growth hormone concentrations in normal subjects did not alter the MCR of HGH. The MCR was relatively constant from day to day and within the day when subjects were evaluated in the supine position. In contrast, the assumption of the upright position was associated with a mean 24% decrease in the MCR. These results were contrasted with the MCR of HGH observed in a small number of patients with altered thyroid function or diabetes mellitus. In six patients with hypothyroidism the MCR (131 +/-36 ml/min) was significantly decreased (P < 0.001); whereas the MCR in eight patients with hyperthyroidism (240 +/-57 ml/min) did not differ from control subjects. The MCR in eight patients with insulin-independent diabetes mellitus (IID) (185 +/-41 ml/min) and in eight patients with insulin-dependent diabetes mellitus (IDD) (136 +/-31 ml/min) were significantly different from control subjects (P = < 0.05 and P = < 0.001, respectively). These data were interpreted to indicate that the plasma HGH-removing mechanism(s) is not saturated at physiologic plasma HGH levels, that plasma HGH levels alone may not permit distinction between variations in pituitary release of the hormone and its rate of clearance from the plasma, and that the estimation of the MCR of HGH may help clarify the mechanism of abnormal plasma HGH responses to various stimuli. Production rates of HGH (PR) in control subjects (347 +/-173 mmug/min) were contrasted with hyperthyroid patients (529 +/-242 mmug/min, P < 0.05), hypothyroid patients (160 +/-69 mmug/min, P < 0.02), IID (245 +/-100 mmug/min, NS), and IDD (363 +/-153 mmug/min, NS

  19. Mapping {sup 15}O Production Rate for Proton Therapy Verification

    SciTech Connect

    Grogg, Kira; Alpert, Nathaniel M.; Zhu, Xuping; Min, Chul Hee; Testa, Mauro; Winey, Brian; Normandin, Marc D.; Shih, Helen A.; Paganetti, Harald; Bortfeld, Thomas; El Fakhri, Georges

    2015-06-01

    Purpose: This work was a proof-of-principle study for the evaluation of oxygen-15 ({sup 15}O) production as an imaging target through the use of positron emission tomography (PET), to improve verification of proton treatment plans and to study the effects of perfusion. Methods and Materials: Dynamic PET measurements of irradiation-produced isotopes were made for a phantom and rabbit thigh muscles. The rabbit muscle was irradiated and imaged under both live and dead conditions. A differential equation was fitted to phantom and in vivo data, yielding estimates of {sup 15}O production and clearance rates, which were compared to live versus dead rates for the rabbit and to Monte Carlo predictions. Results: PET clearance rates agreed with decay constants of the dominant radionuclide species in 3 different phantom materials. In 2 oxygen-rich materials, the ratio of {sup 15}O production rates agreed with the expected ratio. In the dead rabbit thighs, the dynamic PET concentration histories were accurately described using {sup 15}O decay constant, whereas the live thigh activity decayed faster. Most importantly, the {sup 15}O production rates agreed within 2% (P>.5) between conditions. Conclusions: We developed a new method for quantitative measurement of {sup 15}O production and clearance rates in the period immediately following proton therapy. Measurements in the phantom and rabbits were well described in terms of {sup 15}O production and clearance rates, plus a correction for other isotopes. These proof-of-principle results support the feasibility of detailed verification of proton therapy treatment delivery. In addition, {sup 15}O clearance rates may be useful in monitoring permeability changes due to therapy.

  20. GROUND WATER ISSUE - CALCULATION AND USE OF FIRST-ORDER RATE CONSTANTS FOR MONITORED NATURAL ATTENUATION STUDIES

    EPA Science Inventory

    This issue paper explains when and how to apply first-order attenuation rate constant calculations in monitored natural attenuation (MNA) studies. First-order attenuation rate constant calculations can be an important tool for evaluating natural attenuation processes at ground-wa...

  1. Calculation of Top Squark Production in Proton-Proton Collisions

    SciTech Connect

    Linville, Andrea J.; /Washington U., St. Louis /SLAC

    2010-08-25

    Though the Standard Model of particle physics is an elegant theory which has been studied extensively for decades, it leaves many fundamental questions unanswered and is thus widely believed to be incomplete. Possible extensions to the Standard Model (SM) have been postulated and are in the process of being investigated experimentally. The most promising extension is the Minimal Supersymmetric Model (MSSM) which relates every SM particle to a superpartner that differs by 1/2 unit of spin. The lightest supersymmetric quark, or squark, is expected to be the stop, and the search for this particle is an important experimental task. In this analysis, we use parton-model methods to predict the stop production cross section in proton-proton collisions at LHC energies.

  2. Carbon Calculator for Land Use Change from Biofuels Production (CCLUB). Users' Manual and Technical Documentation

    SciTech Connect

    Dunn, Jennifer B.; Qin, Zhangcai; Mueller, Steffen; Kwon, Ho-young; Wander, Michelle M.; Wang, Michael

    2014-09-01

    The Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, Miscanthus, and switchgrass. This document discusses the version of CCLUB released September 30, 2014 which includes corn and three cellulosic feedstocks: corn stover, Miscanthus, and switchgrass.

  3. An evaluation of sediment rating curves for estimating suspended sediment concentrations for subsequent flux calculations

    USGS Publications Warehouse

    Horowitz, A.J.

    2003-01-01

    In the absence of actual suspended sediment concentration (SSC) measurements, hydrologists have used sediment rating (sediment transport) curves to estimate (predict) SSCs for subsequent flux calculations. Various evaluations of the sediment rating-curve method were made using data from long-term, daily sediment-measuring sites within large (>1 000 000 km2), medium ( 1000 km2), and small (<1000 km2) river basins in the USA and Europe relative to the estimation of suspended sediment fluxes. The evaluations address such issues as the accuracy of flux estimations for various levels of temporal resolution as well as the impact of sampling frequency on the magnitude of flux estimation errors. The sediment rating-curve method tends to underpredict high, and overpredict low SSCs. As such, the range of errors associated with concomitant flux estimates for relatively short time-frames (e.g. daily, weekly) are likely to be substantially larger than those associated with longer time-frames (e.g. quarterly, annually) because the over- and underpredictions do not have sufficient time to balance each other. Hence, when error limits must be kept under ??20%, temporal resolution probably should be limited to quarterly or greater. The evaluations indicate that over periods of 20 or more years, errors of <1% can be achieved using a single sediment rating curve based on data spanning the entire period. However, somewhat better estimates for the entire period, and markedly better annual estimates within the period, can be obtained if individual annual sediment rating curves are used instead. Relatively accurate (errors

  4. Mapping 15O production rate for proton therapy verification

    PubMed Central

    Grogg, Kira; Alpert, Nathaniel M.; Zhu, Xuping; Min, Chul Hee; Testa, Mauro; Winey, Brian; Normandin, Marc D.; Shih, Helen A.; Paganetti, Harald; Bortfeld, Thomas; El Fakhri, Georges

    2015-01-01

    Purpose This is a proof-of-principle study for the evaluation of 15O production as an imaging target, through the use of positron emission tomography (PET), to improve verification of proton treatment plans and study the effects of perfusion. Methods and Materials Dynamic PET measurements of irradiation-produced isotopes were taken for a phantom and rabbit thigh muscles. The rabbit muscle was irradiated and imaged in both live and dead conditions. A differential equation was fitted to the phantom and the in vivo data, yielding estimates of the 15O production and clearance rates, which was compared for live versus dead for the rabbit, and to Monte Carlo (MC) predictions. Results PET clearance rates agreed with the decay constants of the dominant radionuclide species in three different phantom materials. In two oxygen-rich materials, the ratio of 15O production rates agreed with the MC prediction. In the dead rabbit thighs, the dynamic PET concentration histories were accurately described using the 15O decay constant, while the live thigh activity decayed faster. Most importantly, the 15O production rates agreed within 2% (p> 0.5) between conditions. Conclusion We developed a new method for quantitative measurement of 15O production and clearance rates in the period immediately following proton therapy. Measurements in the phantom and rabbits were well described in terms of 15O production and clearance rates, plus a correction for other isotopes. These proof-of-principle results support the feasibility of detailed verification of proton therapy treatment delivery. In addition, 15O clearance rates may be useful in monitoring permeability changes due to therapy. PMID:25817530

  5. Improved calculation of total cross section for pair production by relativistic heavy ions

    NASA Technical Reports Server (NTRS)

    Eby, P. B.

    1989-01-01

    A calculation of the total cross section for direct electron-positron pair production by heavy ions is described. It combines the use of the Weizsaecker-Williams method for low-energy transfers and existing calculations for high-energy transfers. Higher-order corrections to the total cross section are calculated based on the Weizsaecher-Williams method and existing results for pair production by photons.

  6. Time-dependent methods for calculating thermal rate coefficients using flux correlation functions

    NASA Astrophysics Data System (ADS)

    Thachuk, Mark; Schatz, George C.

    1992-11-01

    In this paper we study numerical methods for calculating thermal rate coefficients using flux correlation functions, with the goal of determining optimal methods for producing values with a specified accuracy. In all cases we employ grid based methods for solving the time-dependent Schrödinger equation in one mathematical dimension for a simple barrier potential function. The solutions are used to determine the propagator matrix elements needed to evaluate the flux correlation functions. Within this framework, we examine (1) several time-dependent methods for propagating the wave packets, (2) several procedures for evaluating the action of the Hamiltonian on the wave function, (3) the choice of complex time contours for evaluating the rate coefficient expression, (4) alternatives for estimating the initial short-time evolution of the wave packet (which starts as a δ function), (5) quadrature methods for evaluating the spatial and time integrals appearing in the flux correlation function, and (6) special numerical strategies which can dramatically improve the accuracy of the calculation, particularly at low temperatures. We find that several methods yield rate coefficients accurate to 1% or 0.1% using about the same computational effort. These include (a) split-operator time propagators combined with fast-Fourier-transform evaluations of the wave-function derivatives, and (b) the Chebyshev time propagator combined with either an eleventh-order finite-difference or fifth-order spline evaluation of the wave-function derivatives. These finite-difference and spline methods can also be used competitively with the split-operator approach provided that a Crank-Nicholson approximation is utilized in evaluating the action of the kinetic-energy propagator. It was also found that inaccuracies in estimating the initial short-time behavior of the wave function could limit the effectiveness of the more accurate methods. A multigrid approach based on the split

  7. Direct measurement of ozone production rates in Houston in 2009 and comparison with two estimation methods

    NASA Astrophysics Data System (ADS)

    Cazorla, M.; Brune, W. H.; Ren, X.; Lefer, B.

    2011-10-01

    Ozone production rates, P(O3), were measured directly using the Penn State Measurement of Ozone Production Sensor (MOPS) during the Study of Houston Atmospheric Radical Precursors (SHARP 2009). Measured P(O3) peaked in the late morning, with values between 15 ppbv h-1 and 100 ppbv h-1, although values of 40-80 ppbv h-1 were typical for higher ozone days. These measurements were compared against ozone production rates calculated using measurements of hydroperoxyl (HO2), hydroxyl (OH), and nitric oxide (NO) radicals, called "calculated P(O3)". The same comparison was done using modeled radicals obtained from a box model with the RACM2 mechanism, called "modeled P(O3)". Measured and calculated P(O3) had similar peak values but the calculated P(O3) tended to peak earlier in the morning when NO values were higher. Measured and modeled P(O3) had a similar dependence on NO, but the modeled P(O3) was only half the measured P(O3). This difference indicates possible missing radical sources in the box model with the RACM2 mechanism and thus has implications for the ability of air quality models to accurately predict ozone production rates.

  8. The effects of vertical sampling resolution on estimates of plankton biomass and rate calculations in stratified water columns

    NASA Astrophysics Data System (ADS)

    Sutor, Malinda M.; Dagg, Michael J.

    2008-06-01

    The effects of vertical sampling resolution on estimates of plankton biomass and grazing calculations were examined using data collected in two different areas with vertically stratified water columns. Data were collected from one site in the upwelling region off Oregon and from four sites in the Northern Gulf of Mexico, three within the Mississippi River plume and one in adjacent oceanic waters. Plankton were found to be concentrated in discrete layers with sharp vertical gradients at all the stations. Phytoplankton distributions were correlated with gradients in temperature and salinity, but microzooplankton and mesozooplankton distributions were not. Layers of zooplankton were sometimes collocated with layers of phytoplankton, but this was not always the case. Simulated calculations demonstrate that when averages are taken over the water column, or coarser scale vertical sampling resolution is used, biomass and mesozooplankton grazing and filtration rates can be greatly underestimated. This has important implications for understanding the ecological significance of discrete layers of plankton and for assessing rates of grazing and production in stratified water columns.

  9. Calculating the Rate of Senescence From Mortality Data: An Analysis of Data From the ERA-EDTA Registry.

    PubMed

    Koopman, Jacob J E; Rozing, Maarten P; Kramer, Anneke; Abad, José M; Finne, Patrik; Heaf, James G; Hoitsma, Andries J; De Meester, Johan M J; Palsson, Runolfur; Postorino, Maurizio; Ravani, Pietro; Wanner, Christoph; Jager, Kitty J; van Bodegom, David; Westendorp, Rudi G J

    2016-04-01

    The rate of senescence can be inferred from the acceleration by which mortality rates increase over age. Such a senescence rate is generally estimated from parameters of a mathematical model fitted to these mortality rates. However, such models have limitations and underlying assumptions. Notably, they do not fit mortality rates at young and old ages. Therefore, we developed a method to calculate senescence rates from the acceleration of mortality directly without modeling the mortality rates. We applied the different methods to age group-specific mortality data from the European Renal Association-European Dialysis and Transplant Association Registry, including patients with end-stage renal disease on dialysis, who are known to suffer from increased senescence rates (n = 302,455), and patients with a functioning kidney transplant (n = 74,490). From age 20 to 70, senescence rates were comparable when calculated with or without a model. However, when using non-modeled mortality rates, senescence rates were yielded at young and old ages that remained concealed when using modeled mortality rates. At young ages senescence rates were negative, while senescence rates declined at old ages. In conclusion, the rate of senescence can be calculated directly from non-modeled mortality rates, overcoming the disadvantages of an indirect estimation based on modeled mortality rates.

  10. Gate-tunable Kondo resistivity and dephasing rate in graphene studied by numerical renormalization group calculations

    NASA Astrophysics Data System (ADS)

    Lo, Po-Wei; Guo, Guang-Yu; Anders, Frithjof B.

    2014-05-01

    Motivated by the recent observation of the Kondo effect in graphene in transport experiments, we investigate the resistivity and dephasing rate in the Kondo regime due to magnetic impurities in graphene with different chemical potentials (μ). The Kondo effect due to either carbon vacancies or magnetic adatoms in graphene is described by the single-orbital pseudogap asymmetric Anderson impurity model which is solved by the accurate numerical renormalization group method. We find that although the Anderson impurity model considered here is a mixed-valence system, it can be driven into either the Kondo [μ >μc (critical value) >0], mixed-valency (μ ≈μc), or empty-orbital (μ <μc) regime by a gate voltage, giving rise to characteristic features in resistivity and dephasing rate in each regime. Specifically, in the case of μ <μc, the shapes of the resistivity (dephasing rate) curves for different μ are nearly identical. However, as temperature decreases, they start to increase to their maxima at a lower T /TK, but more rapidly [as (TK/T)3/2] than in normal metals [here, T (TK) denotes the (Kondo) temperature]. As T further decreases, after reaching the maximum, the dephasing rate drops more quickly than in normal metals, behaving as (T/TK)3 instead of (T/TK)2. Furthermore, the resistivity has a distinct peak above the saturation value near TK. In the case of μ >μc, in contrast, the resistivity curve has an additional broad shoulder above 10TK and the dephasing rate exhibits an interesting shoulder-peak shape. In the narrow boundary region (μ ≈μc), both the resistivity and dephasing rate curves are similar to the corresponding ones in normal metals. This explains the conventional Kondo-like resistivity from recent experiments on graphene with defects, although the distinct features in the resistivity in the other cases (μ <μc or μ >μc) were not seen in the experiments. The interesting features in the resistivity and dephasing rate are analyzed in

  11. MONTE GENEROSO ROCKFALL FIELD TEST (SWITZERLAND): Comparison between real rockfall volumes measurements and production calculations

    NASA Astrophysics Data System (ADS)

    Matasci, B.; Pedrazzini, A.; Humair, F.; Pedrozzi, G.; Carrea, D.; Loye, A.; Jaboyedoff, M.

    2012-04-01

    The Monte Generoso rockfall testing area is a mountainside located in the canton of Ticino (southern Switzerland) above an important highway that links Italy to Northern Europe. The slope is steep and consists of two high fractured limestone cliffs situated one above the other and divided by a sparse forest. The highway is potentially affected by rockfall hazard leading to the installation of several protective dams. The upper series of dams, collecting the blocks issued from the higher cliff, were emptied in May 2011. This gave the unique opportunity to assess the volumes of blocks produced in a known period of time in the different sections of the upper cliff. The cliff is formed by six catchments zones and the dams are therefore divided in six groups leading to the calculation of six volumes respectively. Based on geological and structural field data, a susceptibility assessment of the six portions of the cliff was performed and the results were compared to the six volume measured before emptying the dams. The aim is to spatially determine the main parameters influencing the rock fall production in the different portions of the cliff and to validate these results according to the material accumulated behind the protective dams. Structural analyses based on high resolution DEM and field investigation was performed to define the orientation and the geometrical characteristics of the discontinuity sets. The bedding plus five joint sets are present in the cliff and display a very small spacing. Multiples wedge structures affect the stability of the cliff and a surface parallel discontinuity set promotes the formation of flake instabilities. Based on a 1m cell-size DEM, the Matterocking method was applied in order to calculate the number of potential failure mechanisms (wedge and planar sliding) for each cell of the DEM. This allowed us to establish a first susceptibility rating for the six portions of the cliff. This rating was then refined by taking into account

  12. Helium release rates and ODH calculations from RHIC magnet cooling line failure

    SciTech Connect

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28

    A catastrophic failure of the magnet cooling lines, similar to the LHC superconducting bus failure incident, could discharge cold helium into the RHIC tunnel and cause an Oxygen Deficiency Hazard (ODH) problem. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the insulating vacuum volumes and discharging via the reliefs into the RHIC tunnel, had been developed. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces are included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Results, including helium discharge rates, helium inventory loss, and the resulting oxygen concentration in the RHIC tunnel area, are reported. Good agreement had been achieved when comparing the simulation results, a RHIC sector depressurization test measurement, and some simple analytical calculations.

  13. Code System to Calculate Radiation Dose Rates Relative to Spent Fuel Shipping Casks.

    1993-05-20

    Version 00 QBF calculates and plots in a short running time, three dimensional radiation dose rate distributions in the form of contour maps on specified planes resulting from cylindrical sources loaded into vehicles or ships. Shielding effects by steel walls and shielding material layers are taken into account in addition to the shadow effect among casks. This code system identifies the critical points on which to focus when designing the radiation shielding structure and wheremore » each of the spent fuel shipping casks should be stored. The code GRAPH reads the output data file of QBF and plots it using the HGX graphics library. QBF unifies the functions of the SMART and MANYCASK codes included in CCC-482.« less

  14. 40 CFR 1066.630 - PDP, SSV, and CFV flow rate calculations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... calculate flow during an emission test. Calculate flow according to 40 CFR 1065.642 instead if you calculate... per revolution, as determined in paragraph (a)(2) of this section. T std = standard temperature =...

  15. STEADY-STATE FLAMMABLE GAS RELEASE RATE CALCULATION AND LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    SciTech Connect

    HU TA

    2007-10-26

    Assess the steady-state flammability level at normal and off-normal ventilation conditions. The methodology of flammability analysis for Hanford tank waste is developed. The hydrogen generation rate model was applied to calculate the gas generation rate for 177 tanks. Flammability concentrations and the time to reach 25% and 100% of the lower flammability limit, and the minimum ventilation rate to keep from 100 of the LFL are calculated for 177 tanks at various scenarios.

  16. Change of Electroweak Nuclear Reaction Rates by CP- and Isospin Symmetry Breaking - A Model Calculation

    NASA Astrophysics Data System (ADS)

    Stumpf, Harald

    2006-09-01

    Based on the assumption that electroweak bosons, leptons and quarks possess a substructure of elementary fermionic constituents, in previous papers the effect of CP-symmetry breaking on the effective dynamics of these particles was calculated. Motivated by the phenomenological procedure in this paper, isospin symmetry breaking will be added and the physical consequences of these calculations will be discussed. The dynamical law of the fermionic constituents is given by a relativistically invariant nonlinear spinor field equation with local interaction, canonical quantization, selfregularization and probability interpretation. The corresponding effective dynamics is derived by algebraic weak mapping theorems. In contrast to the commonly applied modifications of the quark mass matrices, CP-symmetry breaking is introduced into this algebraic formalism by an inequivalent vacuum with respect to the CP-invariant case, represented by a modified spinor field propagator. This leads to an extension of the standard model as effective theory which contains besides the "electric" electroweak bosons additional "magnetic" electroweak bosons and corresponding interactions. If furthermore the isospin invariance of the propagator is broken too, it will be demonstrated in detail that in combination with CP-symmetry breaking this induces a considerable modification of electroweak nuclear reaction rates.

  17. Modeling Atmospheric Emissions and Calculating Mortality Rates Associated with High Volume Hydraulic Fracturing Transportation

    NASA Astrophysics Data System (ADS)

    Mathews, Alyssa

    Emissions from the combustion of fossil fuels are a growing pollution concern throughout the global community, as they have been linked to numerous health issues. The freight transportation sector is a large source of these emissions and is expected to continue growing as globalization persists. Within the US, the expanding development of the natural gas industry is helping to support many industries and leading to increased transportation. The process of High Volume Hydraulic Fracturing (HVHF) is one of the newer advanced extraction techniques that is increasing natural gas and oil reserves dramatically within the US, however the technique is very resource intensive. HVHF requires large volumes of water and sand per well, which is primarily transported by trucks in rural areas. Trucks are also used to transport waste away from HVHF well sites. This study focused on the emissions generated from the transportation of HVHF materials to remote well sites, dispersion, and subsequent health impacts. The Geospatial Intermodal Freight Transport (GIFT) model was used in this analysis within ArcGIS to identify roadways with high volume traffic and emissions. High traffic road segments were used as emissions sources to determine the atmospheric dispersion of particulate matter using AERMOD, an EPA model that calculates geographic dispersion and concentrations of pollutants. Output from AERMOD was overlaid with census data to determine which communities may be impacted by increased emissions from HVHF transport. The anticipated number of mortalities within the impacted communities was calculated, and mortality rates from these additional emissions were computed to be 1 in 10 million people for a simulated truck fleet meeting stricter 2007 emission standards, representing a best case scenario. Mortality rates due to increased truck emissions from average, in-use vehicles, which represent a mixed age truck fleet, are expected to be higher (1 death per 341,000 people annually).

  18. Linear constraint relations in biochemical reaction systems: I. Classification of the calculability and the balanceability of conversion rates.

    PubMed

    van der Heijden, R T; Heijnen, J J; Hellinga, C; Romein, B; Luyben, K C

    1994-01-01

    Measurements provide the basis for process monitoring and control as well as for model development and validation. Systematic approaches to increase the accuracy and credibility of the empirical data set are therefore of great value. In (bio)chemical conversions, linear conservation relations such as the balance equations for charge, enthalpy, and/or chemical elements, can be employed to relate conversion rates. In a pactical situation, some of these rates will be measured (in effect, be calculated directly from primary measurements of, e.g., concentrations and flow rates), as others can or cannot be calculated from the measured ones. When certain measured rates can also be calculated from other measured rates, the set of equations, the accuracy and credibility of the measured rates can indeed be improved by, respectively, balancing and gross error diagnosis. The balanced conversion rates are more accurate, and form a consistent set of data, which is more suitable for further application (e.g., to calculate nonmeasured rates) than the raw measurements. Such an approach has drawn attention in previous studies. The current study deals mainly with the problem of mathematically classifying the conversion rates into balanceable and calculable rates, given the subset of measured rates. The significance of this problem is illustrated with some examples. It is shown that a simple matrix equation can be derived that contains the vector of measured conversion rates and the redundancy matrix R. Matrix R plays a predominant role in the classification problem. In supplementary articles, significance of the redundancy matrix R for an improved gross error diagnosis approach will be shown. In addition, efficient equations have been derived to calculate the balanceable and/or calculable rates. The method is completely based on matrix algebra (principally different from the graph-theoretical approach), and it is easily implemented into a computer program. (c) 1994 John Wiley & Sons

  19. Ensemble Monte Carlo calculation of the hole initiated impact ionization rate in bulk GaAs and silicon using a k-dependent, numerical transition rate formulation

    NASA Technical Reports Server (NTRS)

    Oguzman, Ismail H.; Wang, Yang; Kolnik, Jan; Brennan, Kevin F.

    1995-01-01

    The hole initiated impact ionization rate in bulk silicon and GaAs is calculated using a numerical formulation of the impact ionization transition rate incorporated into an ensemble Monte Carlo simulation. The transition rate is calculated from Fermi's golden rule using a two-body screened Coulomb interaction including a wavevector dependent dielectric function. It is found that the effective threshold for hole initiated ionization is relatively soft in both materials, that the split-off band dominates the ionization process in GaAs. and that no clear dominance by any one band is observed in silicon, though the rate out of the light hole band is greatest.

  20. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION AND LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    SciTech Connect

    MEACHAM JE

    2009-10-26

    This report assesses the steady state flammability level under off normal ventilation conditions in the tank headspace for 28 double-shell tanks (DST) and 149 single shell-tanks (SST) at the Hanford Site. Flammability was calculated using estimated gas release rates, Le Chatelier's rule, and lower flammability limits of fuels in an air mixture. This revision updates the hydrogen generation rate input data for all 177 tanks using waste composition information from the Best Basis Inventory Detail Report (data effective as of August 4,2008). Assuming only barometric breathing, the shortest time to reach 25% of the lower flammability limit is 11 days for DSTs (i.e., tank 241-AZ-10l) and 36 days for SSTs (i.e., tank 241-B-203). Assuming zero ventilation, the shortest time to reach 25% of the lower flammability limit is 10 days for DSTs (i.e., tank 241-AZ-101) and 34 days for SSTs (i.e., tank 241-B-203).

  1. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION AND LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE

    SciTech Connect

    MEACHAM JE

    2008-11-17

    This report assesses the steady state flammability level under off normal ventilation conditions in the tank headspace for 28 double-shell tanks (DST) and 149 single shell-tanks (SST) at the Hanford Site. Flammability was calculated using estimated gas release rates, Le Chatelier's rule, and lower flammability limits of fuels in an air mixture. This revision updates the hydrogen generation rate input data for al1 177 tanks using waste composition information from the Best Basis Inventory Detail Report (data effective as of August 4,2008). Assuming only barometric breathing, the shortest time to reach 25% of the lower flammability limit is 13 days for DSTs (i.e., tank 241-AZ-102) and 36 days for SSTs (i.e., tank 241-B-203). Assuming zero ventilation, the shortest time to reach 25% of the lower flammability limit is 12 days for DSTs (i.e., tank 241-AZ-102) and 34 days for SSTs (i.e., tank 241-B-203).

  2. Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations

    SciTech Connect

    Granero, Domingo; Perez-Calatayud, Jose; Vijande, Javier; Ballester, Facundo; Rivard, Mark J.

    2014-02-15

    Purpose: In skin high-dose-rate (HDR) brachytherapy, sources are located outside, in contact with, or implanted at some depth below the skin surface. Most treatment planning systems use the TG-43 formalism, which is based on single-source dose superposition within an infinite water medium without accounting for the true geometry in which conditions for scattered radiation are altered by the presence of air. The purpose of this study is to evaluate the dosimetric limitations of the TG-43 formalism in HDR skin brachytherapy and the potential clinical impact. Methods: Dose rate distributions of typical configurations used in skin brachytherapy were obtained: a 5 cm × 5 cm superficial mould; a source inside a catheter located at the skin surface with and without backscatter bolus; and a typical interstitial implant consisting of an HDR source in a catheter located at a depth of 0.5 cm. Commercially available HDR{sup 60}Co and {sup 192}Ir sources and a hypothetical {sup 169}Yb source were considered. The Geant4 Monte Carlo radiation transport code was used to estimate dose rate distributions for the configurations considered. These results were then compared to those obtained with the TG-43 dose calculation formalism. In particular, the influence of adding bolus material over the implant was studied. Results: For a 5 cm × 5 cm{sup 192}Ir superficial mould and 0.5 cm prescription depth, dose differences in comparison to the TG-43 method were about −3%. When the source was positioned at the skin surface, dose differences were smaller than −1% for {sup 60}Co and {sup 192}Ir, yet −3% for {sup 169}Yb. For the interstitial implant, dose differences at the skin surface were −7% for {sup 60}Co, −0.6% for {sup 192}Ir, and −2.5% for {sup 169}Yb. Conclusions: This study indicates the following: (i) for the superficial mould, no bolus is needed; (ii) when the source is in contact with the skin surface, no bolus is needed for either {sup 60}Co and {sup 192}Ir. For

  3. A Monte Carlo program to calculate the exposure rate from airborne radioactive gases inside a nuclear reactor containment building.

    PubMed

    Sherbini, S; Tamasanis, D; Sykes, J; Porter, S W

    1986-12-01

    A program was developed to calculate the exposure rate resulting from airborne gases inside a reactor containment building. The calculations were performed at the location of a wall-mounted area radiation monitor. The program uses Monte Carlo techniques and accounts for both the direct and scattered components of the radiation field at the detector. The scattered component was found to contribute about 30% of the total exposure rate at 50 keV and dropped to about 7% at 2000 keV. The results of the calculations were normalized to unit activity per unit volume of air in the containment. This allows the exposure rate readings of the area monitor to be used to estimate the airborne activity in containment in the early phases of an accident. Such estimates, coupled with containment leak rates, provide a method to obtain a release rate for use in offsite dose projection calculations.

  4. Combustion modeling and kinetic rate calculations for a stoichiometric cyclohexane flame. 1. Major reaction pathways.

    PubMed

    Zhang, Hongzhi R; Huynh, Lam K; Kungwan, Nawee; Yang, Zhiwei; Zhang, Shaowen

    2007-05-17

    The Utah Surrogate Mechanism was extended in order to model a stoichiometric premixed cyclohexane flame (P = 30 Torr). Generic rates were assigned to reaction classes of hydrogen abstraction, beta scission, and isomerization, and the resulting mechanism was found to be adequate in describing the combustion chemistry of cyclohexane. Satisfactory results were obtained in comparison with the experimental data of oxygen, major products and important intermediates, which include major soot precursors of C2-C5 unsaturated species. Measured concentrations of immediate products of fuel decomposition were also successfully reproduced. For example, the maximum concentrations of benzene and 1,3-butadiene, two major fuel decomposition products via competing pathways, were predicted within 10% of the measured values. Ring-opening reactions compete with those of cascading dehydrogenation for the decomposition of the conjugate cyclohexyl radical. The major ring-opening pathways produce 1-buten-4-yl radical, molecular ethylene, and 1,3-butadiene. The butadiene species is formed via beta scission after a 1-4 internal hydrogen migration of 1-hexen-6-yl radical. Cascading dehydrogenation also makes an important contribution to the fuel decomposition and provides the exclusive formation pathway of benzene. Benzene formation routes via combination of C2-C4 hydrocarbon fragments were found to be insignificant under current flame conditions, inferred by the later concentration peak of fulvene, in comparison with benzene, because the analogous species series for benzene formation via dehydrogenation was found to be precursors with regard to parent species of fulvene. PMID:17388269

  5. ALPHN: A computer program for calculating ({alpha}, n) neutron production in canisters of high-level waste

    SciTech Connect

    Salmon, R.; Hermann, O.W.

    1992-10-01

    The rate of neutron production from ({alpha}, n) reactions in canisters of immobilized high-level waste containing borosilicate glass or glass-ceramic compositions is significant and must be considered when estimating neutron shielding requirements. The personal computer program ALPHA calculates the ({alpha}, n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the ({alpha}, n) neutron production of each actinide in neutrons per second and the total for the canister. The ({alpha}, n) neutron production rates are source terms only; that is, they are production rates within the glass and do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister. In a typical application, these cases might represent the same canister of vitrified high-level waste at eight different decay times. Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 35 s on an IBM AT personal computer. Results of an example based on an expected canister composition at the Defense Waste Processing Facility are shown.

  6. ALPHN: A computer program for calculating ([alpha], n) neutron production in canisters of high-level waste

    SciTech Connect

    Salmon, R.; Hermann, O.W.

    1992-10-01

    The rate of neutron production from ([alpha], n) reactions in canisters of immobilized high-level waste containing borosilicate glass or glass-ceramic compositions is significant and must be considered when estimating neutron shielding requirements. The personal computer program ALPHA calculates the ([alpha], n) neutron production rate of a canister of vitrified high-level waste. The user supplies the chemical composition of the glass or glass-ceramic and the curies of the alpha-emitting actinides present. The output of the program gives the ([alpha], n) neutron production of each actinide in neutrons per second and the total for the canister. The ([alpha], n) neutron production rates are source terms only; that is, they are production rates within the glass and do not take into account the shielding effect of the glass. For a given glass composition, the user can calculate up to eight cases simultaneously; these cases are based on the same glass composition but contain different quantities of actinides per canister. In a typical application, these cases might represent the same canister of vitrified high-level waste at eight different decay times. Run time for a typical problem containing 20 chemical species, 24 actinides, and 8 decay times was 35 s on an IBM AT personal computer. Results of an example based on an expected canister composition at the Defense Waste Processing Facility are shown.

  7. 37 CFR 1.779 - Calculation of patent term extension for a veterinary biological product.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... extension for a veterinary biological product. 1.779 Section 1.779 Patents, Trademarks, and Copyrights... Calculation of patent term extension for a veterinary biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a veterinary biological product is eligible for extension, the...

  8. 37 CFR 1.779 - Calculation of patent term extension for a veterinary biological product.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... extension for a veterinary biological product. 1.779 Section 1.779 Patents, Trademarks, and Copyrights... Calculation of patent term extension for a veterinary biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a veterinary biological product is eligible for extension, the...

  9. 37 CFR 1.779 - Calculation of patent term extension for a veterinary biological product.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... extension for a veterinary biological product. 1.779 Section 1.779 Patents, Trademarks, and Copyrights... Calculation of patent term extension for a veterinary biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a veterinary biological product is eligible for extension, the...

  10. 37 CFR 1.779 - Calculation of patent term extension for a veterinary biological product.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... extension for a veterinary biological product. 1.779 Section 1.779 Patents, Trademarks, and Copyrights... Calculation of patent term extension for a veterinary biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a veterinary biological product is eligible for extension, the...

  11. 19 CFR 351.407 - Calculation of constructed value and cost of production.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... production. 351.407 Section 351.407 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE... Normal Value § 351.407 Calculation of constructed value and cost of production. (a) Introduction. This... production. (See section 773(f) of the Act.) (b) Determination of value under the major input rule....

  12. 19 CFR 351.407 - Calculation of constructed value and cost of production.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... production. 351.407 Section 351.407 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE... Normal Value § 351.407 Calculation of constructed value and cost of production. (a) Introduction. This... production. (See section 773(f) of the Act.) (b) Determination of value under the major input rule....

  13. Calculated organ doses for Mayak production association central hall using ICRP and MCNP.

    PubMed

    Choe, Dong-Ok; Shelkey, Brenda N; Wilde, Justin L; Walk, Heidi A; Slaughter, David M

    2003-03-01

    As part of an ongoing dose reconstruction project, equivalent organ dose rates from photons and neutrons were estimated using the energy spectra measured in the central hall above the graphite reactor core located in the Russian Mayak Production Association facility. Reconstruction of the work environment was necessary due to the lack of personal dosimeter data for neutrons in the time period prior to 1987. A typical worker scenario for the central hall was developed for the Monte Carlo Neutron Photon-4B (MCNP) code. The resultant equivalent dose rates for neutrons and photons were compared with the equivalent dose rates derived from calculations using the conversion coefficients in the International Commission on Radiological Protection Publications 51 and 74 in order to validate the model scenario for this Russian facility. The MCNP results were in good agreement with the results of the ICRP publications indicating the modeling scenario was consistent with actual work conditions given the spectra provided. The MCNP code will allow for additional orientations to accurately reflect source locations.

  14. Calculated organ doses for Mayak production association central hall using ICRP and MCNP.

    PubMed

    Choe, Dong-Ok; Shelkey, Brenda N; Wilde, Justin L; Walk, Heidi A; Slaughter, David M

    2003-03-01

    As part of an ongoing dose reconstruction project, equivalent organ dose rates from photons and neutrons were estimated using the energy spectra measured in the central hall above the graphite reactor core located in the Russian Mayak Production Association facility. Reconstruction of the work environment was necessary due to the lack of personal dosimeter data for neutrons in the time period prior to 1987. A typical worker scenario for the central hall was developed for the Monte Carlo Neutron Photon-4B (MCNP) code. The resultant equivalent dose rates for neutrons and photons were compared with the equivalent dose rates derived from calculations using the conversion coefficients in the International Commission on Radiological Protection Publications 51 and 74 in order to validate the model scenario for this Russian facility. The MCNP results were in good agreement with the results of the ICRP publications indicating the modeling scenario was consistent with actual work conditions given the spectra provided. The MCNP code will allow for additional orientations to accurately reflect source locations. PMID:12645766

  15. Proceedings of a Workshop on Cosmogenic Nuclide Production Rates

    NASA Technical Reports Server (NTRS)

    Englert, Peter A. J. (Editor); Reedy, Robert C. (Editor); Michel, Rolf (Editor)

    1989-01-01

    Abstracts of reports from the proceedings are presented. The presentations were divided into discussion topics. The following general topic areas were used: (1) measured cosmogenic noble gas and radionuclide production rates in meteorite and planetary surface samples; (2) cross-section measurements and simulation experiments; and (3) interpretation of sample studies and simulation experiments.

  16. RADIOLYTIC GAS PRODUCTION RATES OF POLYMERS EXPOSED TO TRITIUM GAS

    SciTech Connect

    Clark, E.

    2013-08-31

    Data from previous reports on studies of polymers exposed to tritium gas is further analyzed to estimate rates of radiolytic gas production. Also, graphs of gas release during tritium exposure from ultrahigh molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, a trade name is Teflon®), and Vespel® polyimide are re-plotted as moles of gas as a function of time, which is consistent with a later study of tritium effects on various formulations of the elastomer ethylene-propylene-diene monomer (EPDM). These gas production rate estimates may be useful while considering using these polymers in tritium processing systems. These rates are valid at least for the longest exposure times for each material, two years for UHMW-PE, PTFE, and Vespel®, and fourteen months for filled and unfilled EPDM. Note that the production “rate” for Vespel® is a quantity of H{sub 2} produced during a single exposure to tritium, independent of length of time. The larger production rate per unit mass for unfilled EPDM results from the lack of filler- the carbon black in filled EPDM does not produce H{sub 2} or HT. This is one aspect of how inert fillers reduce the effects of ionizing radiation on polymers.

  17. 76 FR 53982 - New Postal Product and Rate Adjustment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ...). In Order No. 700, the Commission approved the functionally equivalent HongKong Post Agreement.\\2\\ The..., TNT Agreement, and the HongKong Post Agreement. The Postal Service requests that the China Post 2011... Operators 1 product. Notice at 2. \\2\\ See Docket No. R2011-4, Order Approving Rate Adjustment for...

  18. Calculation of gamma radiation dose rate and radon concentration due to granites used as building materials in Iran.

    PubMed

    Abbasi, A

    2013-07-01

    Natural radioactivity concentrations in granite building materials that are commonly used in Iran have been surveyed by using a gamma-ray spectrometry system, using a high-purity germanium detector. Health hazards from gamma radiation doses due to granite and radon concentration have been calculated. The dose rate of exposure from granite building materials on humans is obtained as a result of an external exposure from gamma-emitting radionuclides in the granites. Another mode of exposure is from the inhalation of the decay products of (222)Ra and (220)Ra. The average concentrations of (232)Th, (226)Ra and (40)K were in the ranges of 6.5-172.2, 3.8-94.2 and 556.9-1539.2 Bq kg(-1), respectively. The radon exhalation rates have also been studied and values were in the range of 0.32 ± 0.01 to 7.86 ± 1.65 Bq m(-2) h(-1). For two models of standard living rooms (5.0 m × 4.0 m area; 2.8 m), the radon concentration (Ci) and the absorbed dose (D) rates were calculated and the results were found to be 10.64-29.32 Bq m(-3), 3.84-68.02 nGy h(-1) and 0.02-0.33 mSv y(-1) for Model 1, 10.07-15.38 Bq m(-3) and 2.29-39.99 nGy h(-1) for Model 2, respectively. According to our estimations, mechanical ventilation systems (λν = 0.5 h(-1)) in a room all granite samples would produce radon concentration <100 Bq m(-3). PMID:23396882

  19. Calculation of gamma radiation dose rate and radon concentration due to granites used as building materials in Iran.

    PubMed

    Abbasi, A

    2013-07-01

    Natural radioactivity concentrations in granite building materials that are commonly used in Iran have been surveyed by using a gamma-ray spectrometry system, using a high-purity germanium detector. Health hazards from gamma radiation doses due to granite and radon concentration have been calculated. The dose rate of exposure from granite building materials on humans is obtained as a result of an external exposure from gamma-emitting radionuclides in the granites. Another mode of exposure is from the inhalation of the decay products of (222)Ra and (220)Ra. The average concentrations of (232)Th, (226)Ra and (40)K were in the ranges of 6.5-172.2, 3.8-94.2 and 556.9-1539.2 Bq kg(-1), respectively. The radon exhalation rates have also been studied and values were in the range of 0.32 ± 0.01 to 7.86 ± 1.65 Bq m(-2) h(-1). For two models of standard living rooms (5.0 m × 4.0 m area; 2.8 m), the radon concentration (Ci) and the absorbed dose (D) rates were calculated and the results were found to be 10.64-29.32 Bq m(-3), 3.84-68.02 nGy h(-1) and 0.02-0.33 mSv y(-1) for Model 1, 10.07-15.38 Bq m(-3) and 2.29-39.99 nGy h(-1) for Model 2, respectively. According to our estimations, mechanical ventilation systems (λν = 0.5 h(-1)) in a room all granite samples would produce radon concentration <100 Bq m(-3).

  20. Reaction rate and energy-loss rate for photopair production by relativistic nuclei

    NASA Technical Reports Server (NTRS)

    Chodorowski, Michal J.; Zdziarski, Andrzej A.; Sikora, Marek

    1992-01-01

    The process of e(+/-) pair production by relativistic nuclei on ambient photons is considered. The process is important for cosmic-ray nuclei in interstellar and intergalactic space as well as in galactic and extragalactic compact objects. The rate of this process is given by an integral of the cross section over the photon angular and energy distribution. In the case of isotropic photons, the angular integration is performed to provide an expression for the rate at given photon energy in the nucleus rest frame. The total rate then becomes a single integral of that rate over the photon energy distribution. Formulas are also given for the fractional energy loss of a relativistic nucleus colliding with a photon of a given energy in the rest frame. The nucleus energy-loss rate is integrated over the photon angular distribution in the case of isotropic photons, and simple fits are provided.

  1. MEASURED AND CALCULATED HEATING AND DOSE RATES FOR THE HFIR HB4 BEAM TUBE AND COLD SOURCE

    SciTech Connect

    Slater, Charles O; Primm, Trent; Pinkston, Daniel; Cook, David Howard; Selby, Douglas L; Ferguson, Phillip D; Bucholz, James A; Popov, Emilian L

    2009-03-01

    The High Flux Isotope Reactor at the Oak Ridge National Laboratory was upgraded to install a cold source in horizontal beam tube number 4. Calculations were performed and measurements were made to determine heating within the cold source and dose rates within and outside a shield tunnel surrounding the beam tube. This report briefly describes the calculations and presents comparisons of the measured and calculated results. Some calculated dose rates are in fair to good agreement with the measured results while others, particularly those at the shield interfaces, differ greatly from the measured results. Calculated neutron exposure to the Teflon seals in the hydrogen transfer line is about one fourth of the measured value, underpredicting the lifetime by a factor of four. The calculated cold source heating is in good agreement with the measured heating.

  2. 39 CFR 3010.23 - Calculation of percentage change in rates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... in rates = ER09NO07.000 Where, N = number of rate cells in the class i = denotes a rate cell (i = 1...) The term rate cell as applied in the test for compliance with the annual limitation shall apply to... rate cells separate and distinct from the corresponding non-seasonal or permanent rates. (b) For...

  3. Comparison of Rates of Flagellate Bacterivory and Bacterial Production in a Marine Coastal System

    PubMed Central

    Barcina, Isabel; Ayo, Begoña; Unanue, Marian; Egea, Luis; Iriberri, Juan

    1992-01-01

    Protozoan predation on bacteria and bacterioplankton secondary production were simultaneously determined in La Salvaje Beach water during 1990. Protozoan grazing on bacterioplankton was measured from fluorescently labeled bacterium uptake rates; estimates of bacterial secondary production were obtained from [3H]thymidine incorporation rates. Two different conversion factors were used to transform thymidine incorporation rates into bacterial production rates; both of them were specific for La Salvaje Beach and were calculated by using empirical and semitheoretical approaches. The average flagellate predation rate was 14.0 bacteria flagellate-1 h-1; the average population predation rate was 7.35 x 106 bacteria liter-1 h-1. The estimates of bacterial production differed greatly depending on the conversion factor used, and so did the percentages of bacterial production consumed by flagellated protozoa (4.6% when the empirical conversion factor for La Salvaje Beach was used and 113% when the semitheoretical conversion factor specific for this system was used). The ecological implications of each of these values are discussed. PMID:16348819

  4. Custom Vector Graphic Viewers for Analysis of Element Production Calculations in Computational Astrophysics

    NASA Astrophysics Data System (ADS)

    Lingerfelt, E. J.; Guidry, M. W.

    2003-05-01

    We are developing a set of extendable, cross-platform tools and interfaces using Java and vector graphic technologies to facilitate element production calculations in computational astrophysics. The Java technologies are customizable and portable, and can be utilized as stand-alone applications or distributed across a network. These tools, which have broad applications in general scientific visualization, has been used to explore and analyze a large library of nuclear reaction rates and visualize results of explosive nucleosynthesis calculations. In this presentation, we discuss a new capability to export the results of such applications directly into the XML (Extensible Markup Language) format, which may then be displayed through custom vector graphic viewers. The vector graphic technologies employed here, namely the SWF format, offer the ability to view results in an interactive, scalable vector graphics format, which leads to a dramatic (ten-fold) reduction in visualization file sizes while maintaining high visual quality and interactive control. *Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

  5. Automated Production of High Rep Rate Foam Targets

    NASA Astrophysics Data System (ADS)

    Hall, F.; Spindloe, C.; Haddock, D.; Tolley, M.; Nazarov, W.

    2016-04-01

    Manufacturing low density targets in the numbers needed for high rep rate experiments is highly challenging. This report summarises advances from manual production to semiautomated and the improvements that follow both in terms of production time and target uniformity. The production process is described and shown to be improved by the integration of an xyz robot with dispensing capabilities. Results are obtained from manual and semiautomated production runs and compared. The variance in the foam thickness is reduced significantly which should decrease experimental variation due to target parameters and could allow for whole batches to be characterised by the measurement of a few samples. The work applies to both foil backed and free standing foam targets.

  6. Calculation of Heavy Ion Inactivation and Mutation Rates in Radial Dose Model of Track Structure

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Wilson, John W.; Shavers, Mark R.; Katz, Robert

    1997-01-01

    In the track structure model, the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated by using the dose response of the system to gamma rays and the radial dose of the ions and may be equal to unity at small impact parameters. We apply the track structure model to recent data with heavy ion beams irradiating biological samples of E. Coli, B. Subtilis spores, and Chinese hamster (V79) cells. Heavy ions have observed cross sections for inactivation that approach and sometimes exceed the geometric size of the cell nucleus. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT (hypoxanthine guanine phosphoribosyl transferase) mutations in V79 cells, and good agreement is found. Calculations show the high probability for mutation by relativistic ions due to the radial extension of ions track from delta rays. The effects of inactivation on mutation rates make it very unlikely that a single parameter such as LET (linear energy transfer) can be used to specify radiation quality for heavy ion bombardment.

  7. 19 CFR 351.407 - Calculation of constructed value and cost of production.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 3 2012-04-01 2012-04-01 false Calculation of constructed value and cost of production. 351.407 Section 351.407 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND COUNTERVAILING DUTIES Calculation of Export Price, Constructed Export Price, Fair Value, and Normal Value § 351.407...

  8. Production Rate of Cosmogenic 10Be in Magnetite

    NASA Astrophysics Data System (ADS)

    Granger, D. E.; Rogers, H. E.; Riebe, C. S.; Lifton, N. A.

    2013-12-01

    Cosmogenic 10Be is widely used for determining exposure ages, soil production rates, and catchment-wide erosion rates. To date, measurements have been almost exclusively in the mineral quartz (SiO2), which is resistant to weathering and easily cleaned of meteoric 10Be contamination. However, this limits the method to quartz-bearing rocks and requires specialized laboratories due to the need for large quantities of hydrofluoric acid (HF). Here, we present initial results for 10Be production in the mineral magnetite (Fe3O4). Magnetite offers several advantages over quartz; it is (1) present in mafic rocks, (2) easily collected in the field, (3) quickly and easily separated in the lab, and (4) digested without HF. In addition, 10Be can be measured in both detrital quartz and magnetite from the same catchment to yield information about the intensity of chemical weathering (Rogers et al., this conference). The 10Be production rate in magnetite relative to quartz was determined for a granitic boulder from Mt. Evans, Colorado, USA. The boulder was crushed and homogenized to facilitate production rate comparisons among various minerals. We separated magnetite using a combination of hand magnets, froth flotation, and a variety of selective chemical dissolutions in dithionite-citrate-bicarbonate solution, 5% nitric acid (HNO3) and 1% HF/HNO3. Six aliquots of magnetite were analyzed for 10Be and compared to quartz. Three aliquots that were not exposed to 1% HF/HNO3 were contaminated with meteoric 10Be, probably associated with residual mica. Three aliquots that were exposed to 1% HF/HNO3 treatments agreed to within 2% measurement uncertainty. Our preliminary results indicate that the relative production rate by mass of 10Be in magnetite and quartz is 0.462 × 0.012. Our results are similar to theoretically predicted values. Recently updated excitation functions for neutron and proton spallation reactions allow us to partition 10Be production in quartz and magnetite among

  9. Entropy production rate as a constraint for collisionless fluid closures

    SciTech Connect

    Fleurence, E.; Sarazin, Y.; Garbet, X.; Dif-Pradalier, G.; Ghendrih, Ph.; Grandgirard, V.; Ottaviani, M.

    2006-11-30

    A novel method is proposed to construct collisionless fluid closures accounting for some kinetic properties. The first dropped fluid moment is assumed to be a linear function of the lower order ones. Optimizing the agreement between the fluid and kinetic entropy production rates is used to constrain the coefficients of the linear development. This procedure is applied to a reduced version of the interchange instability. The closure, involving the absolute value of the wave vector, is non-local in real space. In this case, the linear instability thresholds are the same, and the linear growth rates exhibit similar characteristics. Such a method is applicable to other models and classes of instabilities.

  10. Calculation of the Rate of M>6.5 Earthquakes for California and Adjacent Portions of Nevada and Mexico

    USGS Publications Warehouse

    Frankel, Arthur; Mueller, Charles

    2008-01-01

    One of the key issues in the development of an earthquake recurrence model for California and adjacent portions of Nevada and Mexico is the comparison of the predicted rates of earthquakes with the observed rates. Therefore, it is important to make an accurate determination of the observed rate of M>6.5 earthquakes in California and the adjacent region. We have developed a procedure to calculate observed earthquake rates from an earthquake catalog, accounting for magnitude uncertainty and magnitude rounding. We present a Bayesian method that corrects for the effect of the magnitude uncertainty in calculating the observed rates. Our recommended determination of the observed rate of M>6.5 in this region is 0.246 ? 0.085 (for two sigma) per year, although this rate is likely to be underestimated because of catalog incompleteness and this uncertainty estimate does not include all sources of uncertainty.

  11. 39 CFR 3010.23 - Calculation of percentage change in rates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) The term rate cell as applied in the test for compliance with the annual limitation shall apply to... rate cells separate and distinct from the corresponding non-seasonal or permanent rates. (b) For each... rate cell in the class is multiplied by the planned rate for the respective cell and the...

  12. Neutron capture production rates of cosmogenic 60Co, 59Ni and 36Cl in stony meteorites

    NASA Technical Reports Server (NTRS)

    Spergel, M. S.; Reedy, R. C.; Lazareth, O. W.; Levy, P. W.

    1986-01-01

    Results for neutron flux calculations in stony meteoroids (of various radii and compositions) and production rates for Cl-36, Ni-59, and Co-60 are reported. The Ni-59/Co-60 ratio is nearly constant with depth in most meteorites: this effect is consistent with the neutron flux and capture cross section properties. The shape of the neutron flux energy spectrum, varies little with depth in a meteorite. The size of the parent meteorite can be determined from one of its fragments, using the Ni-59/Co-60 ratios, if the parent meteorite was less than 75 g/cm(2) in radius. If the parent meteorite was larger, a lower limit on the size of the parent meteorite can be determined from a fragment. In C3 chondrites this is not possible. In stony meteorites with R less than 50 g/cm(2) the calculated Co-60 production rates (mass less than 4 kg), are below 1 atom/min g-Co. The highest Co-60 production rates occur in stony meteorites with radius about 250 g/cm(2) (1.4 m across). In meteorites with radii greater than 400 g/cm(2), the maximum Co-60 production rate occurs at a depth of about 175 g/cm(2) in L-chondrite, 125 g/cm(2) in C3 chrondrite, and 190 g/cm(2) in aubrites.

  13. Ion production rate in a boreal forest based on ion, particle and radiation measurements

    NASA Astrophysics Data System (ADS)

    Laakso, L.; Petäjä, T.; Lehtinen, K. E. J.; Kulmala, M.; Paatero, J.; Hõrrak, U.; Tammet, H.; Joutsensaari, J.

    2004-07-01

    In this study the ion production rates in a boreal forest are studied based on two different methods: 1) cluster ion and particle concentration measurements, 2) external radiation and radon concentration measurements. Both methods produce reasonable estimates for ion production rates. The average ion production rate calculated from aerosol particle size distribution and air ion mobility distribution measurements was 2.6 cm-3s-1 and based on external radiation and radon measurements 4.5 cm-3s-1. The first method based on ion and particle measurements gave lower values for the ion production rates especially during the day. A possible reason for this is that particle measurements started only from 3 nm, so the sink of small ions during the nucleation events was underestimated. Another reason is that the possible fogs, which caused an extra sink of small ions are not taken into account in the calculations. It may also be possible that the hygroscopic growth factors of aerosol particles were underestimated. A fourth possible reason for the discrepancy is the nucleation mechanism itself. If the ions were somehow present in the nucleation process, there could have been an additional ion sink during the nucleation days. On the other hand, not all the radiation energy is converted to ions and the possible effect of alpha recoil is also omitted.

  14. The 21Ne production rate in quartz revisited

    NASA Astrophysics Data System (ADS)

    Niedermann, Samuel

    2000-12-01

    I have revised our earlier production rate determination of 21Ne in terrestrial quartz [S. Niedermann, Th. Graf, J.S. Kim, C.P. Kohl, K. Marti and K. Nishiizumi (1994) Earth Planet. Sci. Lett. 125, 341-355], taking account of improved knowledge about the exposure age of samples used in that work and applying distinct procedures for scaling to sea level and high latitudes. The corrected value of 19.0±3.7 atoms g -1 a -1 is in excellent agreement with expectations based on nuclear properties [J. Masarik and R.C. Reedy (1995) Earth Planet. Sci. Lett. 136, 381-395] and closely corresponds to the present-day production rate. In the case of substantial variations of the geomagnetic field in the past, as proposed by several studies, the revised value can consistently be used with suitable correction methods.

  15. TNG calculations and evaluations of photon production data for some ENDF/B-VI materials

    SciTech Connect

    Fu, C.Y.

    1994-12-31

    Among the new evaluations in the ENDF/B-VI general purpose files, 25 were based on calculations using TNG, a consistent Hauser-Feshbach pre-equilibrium nuclear model code. The photon production cross sections and spectra were calculated simultaneously with the particle emission cross sections and spectra, assuring energy balance for each reaction. The theories used in TNG for these calculations are summarized. Several examples of photon production data, taken from the ENDF/B-VI files, are compared with the available experimental data.

  16. On the accuracy of instantaneous gas exchange rates, energy expenditure, and respiratory quotient calculations obtained in indirect whole room calorimeter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper analyzes the accuracy of metabolic rate calculations performed in the whole room indirect calorimeter using the molar balance equations. The equations are treated from the point of view of cause-effect relationship where the gaseous exchange rates representing the unknown causes need to b...

  17. 76 FR 41283 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-13

    ..., published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  18. 78 FR 1222 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... Decision 85-93, published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on... Overdue Accounts and Refunds on Customs Duties AGENCY: U.S. Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  19. 75 FR 59279 - Quarterly IRS Interest Rates Used In Calculating Interest On Overdue Accounts and Refunds On...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-27

    ... 29, 1985 (50 FR 21832), the interest rate paid on applicable overpayments or underpayments of customs... Overdue Accounts and Refunds On Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  20. 76 FR 20697 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ..., published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  1. 77 FR 59411 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-27

    ..., published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  2. 75 FR 37823 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-30

    ... 29, 1985 (50 FR 21832), the interest rate paid on applicable overpayments or underpayments of customs... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  3. 77 FR 2308 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-17

    ... Decision 85-93, published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on... Overdue Accounts and Refunds on Customs Duties AGENCY: U.S. Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  4. 77 FR 18256 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-27

    ..., published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  5. 78 FR 20349 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-04

    ... Decision 85-93, published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on... Overdue Accounts and Refunds on Customs Duties AGENCY: U.S. Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  6. 76 FR 64964 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-19

    ... Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable overpayments or... Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of Homeland... Service interest rates used to calculate interest on overdue accounts (underpayments) and...

  7. 75 FR 419 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... 29, 1985 (50 FR 21832), the interest rate paid on applicable overpayments or underpayments of customs... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  8. 77 FR 38076 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ..., published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable... Overdue Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  9. 78 FR 37839 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-24

    ..., published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on applicable... Overdue Accounts and Refunds on Customs Duties AGENCY: U.S. Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  10. 78 FR 63238 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... Decision 85-93, published in the Federal Register on May 29, 1985 (50 FR 21832), the interest rate paid on... Overdue Accounts and Refunds on Customs Duties AGENCY: U.S. Customs and Border Protection, Department of... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments)...

  11. 42 CFR 413.220 - Methodology for calculating the per-treatment base rate under the ESRD prospective payment system...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rate under the ESRD prospective payment system effective January 1, 2011. 413.220 Section 413.220... Disease (ESRD) Services and Organ Procurement Costs § 413.220 Methodology for calculating the per-treatment base rate under the ESRD prospective payment system effective January 1, 2011. (a) Data...

  12. 42 CFR 413.220 - Methodology for calculating the per-treatment base rate under the ESRD prospective payment system...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... rate under the ESRD prospective payment system effective January 1, 2011. 413.220 Section 413.220... Disease (ESRD) Services and Organ Procurement Costs § 413.220 Methodology for calculating the per-treatment base rate under the ESRD prospective payment system effective January 1, 2011. (a) Data...

  13. 42 CFR 413.220 - Methodology for calculating the per-treatment base rate under the ESRD prospective payment system...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rate under the ESRD prospective payment system effective January 1, 2011. 413.220 Section 413.220... Disease (ESRD) Services and Organ Procurement Costs § 413.220 Methodology for calculating the per-treatment base rate under the ESRD prospective payment system effective January 1, 2011. (a) Data...

  14. Application of adjusted data in calculating fission-product decay energies and spectra

    NASA Astrophysics Data System (ADS)

    George, D. C.; Labauve, R. J.; England, T. R.

    1982-06-01

    The code ADENA, which approximately calculates fussion-product beta and gamma decay energies and spectra in 19 or fewer energy groups from a mixture of U235 and Pu239 fuels, is described. The calculation uses aggregate, adjusted data derived from a combination of several experiments and summation results based on the ENDF/B-V fission product file. The method used to obtain these adjusted data and the method used by ADENA to calculate fission-product decay energy with an absorption correction are described, and an estimate of the uncertainty of the ADENA results is given. Comparisons of this approximate method are made to experimental measurements, to the ANSI/ANS 5.1-1979 standard, and to other calculational methods. A listing of the complete computer code (ADENA) is contained in an appendix. Included in the listing are data statements containing the adjusted data in the form of parameters to be used in simple analytic functions.

  15. r-PROCESS LANTHANIDE PRODUCTION AND HEATING RATES IN KILONOVAE

    SciTech Connect

    Lippuner, Jonas; Roberts, Luke F.

    2015-12-20

    r-process nucleosynthesis in material ejected during neutron star mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients depend on the composition of the ejecta, which determines the local heating rate from nuclear decays and the opacity. Kasen et al. and Tanaka and Hotokezaka pointed out that lanthanides can drastically increase the opacity in these outflows. We use the new general-purpose nuclear reaction network SkyNet to carry out a parameter study of r-process nucleosynthesis for a range of initial electron fractions Y{sub e}, initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Y{sub e} ≳ 0.22−0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Y{sub e} lead to reduced heating rates, due to individual nuclides dominating the heating. We calculate approximate light curves with a simplified gray radiative transport scheme. The light curves peak at about a day (week) in the lanthanide-free (-rich) cases. The heating rate does not change much as the ejecta becomes lanthanide-free with increasing Y{sub e}, but the light-curve peak becomes about an order of magnitude brighter because it peaks much earlier when the heating rate is larger. We also provide parametric fits for the heating rates between 0.1 and 100 days, and we provide a simple fit in Y{sub e}, s, and τ to estimate whether or not the ejecta is lanthanide-rich.

  16. A simplified method for calculating the atmospheric heating rate by absorption of solar radiation in the stratosphere and mesosphere

    NASA Technical Reports Server (NTRS)

    Shimazaki, T.; Helmle, L. C.

    1979-01-01

    Calculations of the atmospheric heating rate by absorption of solar radiation by O3, H2O, and CO2 are reported. The method needs only seven parameters for each molecule and is particularly useful for heating calculations in three-dimensional global circulation models below 80 km. Applying the formula to the observed distributions of O3, H2O, and CO2 produces reasonable latitudinal and seasonal variations in the heating rate. The calculated heating rate, however, is sensitive to the global distributions of the absorbing gases, and uncertainties in the O3 distribution above approximately 50 km and the H2O distribution below approximately 20 km may seriously affect the global distributions of the heating rate in these regions.

  17. Photochemical free radical production rates in the eastern Caribbean

    NASA Astrophysics Data System (ADS)

    Dister, Brian; Zafiriou, Oliver C.

    1993-02-01

    Potential photochemical production rates of total (NO-scavengeable) free radicals were surveyed underway (> 900 points) in the eastern Caribbean and Orinoco delta in spring and fall 1988. These data document seasonal trends and large-scale (˜ 10-1000 km) variability in the pools of sunlight-generated reactive transients, which probably mediate a major portion of marine photoredox transformations. Radical production potential was detectable in all waters and was reasonably quantifiable at rates above 0.25 nmol L-1 min-1 sun-1. Radical production rates varied from ˜ 0.1-0.5 nmol L-1 min-1 of full-sun illumination in "blue water" to > 60 nmol L-1 min-1 in some estuarine waters in the high-flow season. Qualitatively, spatiotemporal potential rate distributions strikingly resembled that of "chlorophyll" (a riverine-influence tracer of uncertain specificity) in 1979-1981 CZCS images of the region [Müller-Karger et al., 1988] at all scales. Basin-scale occurrence of greatly enhanced rates in fall compared to spring is attributed to terrestrial chromophore inputs, primarily from the Orinoco River, any contributions from Amazon water and nutrient-stimulus effects could not be resolved. A major part of the functionally photoreactive colored organic matter (COM) involved in radical formation clearly mixes without massive loss out into high-salinity waters, although humic acids may flocculate in estuaries. A similar conclusion applies over smaller scales for COM as measured optically [Blough et al., this issue]. Furthermore, optical absorption and radical production rates were positively correlated in the estuarine region in fall. These cruises demonstrated that photochemical techniques are now adequate to treat terrestrial photochemical chromophore inputs as an estuarine mixing problem on a large scale, though the ancillary data base does not currently support such an analysis in this region. Eastern Caribbean waters are not markedly more reactive at comparable salinities

  18. Theoretical calculation of product contents: battery and cathode ray tube examples.

    PubMed

    Thomas, Valerie M

    2003-05-01

    Most product environmental assessments are based on manufacturer-supplied data on the material content of the product. This paper explores the potential for the material content of key components to be estimated with theoretical calculations. Two examples, the amount of cadmium in a nickel-cadmium battery and the amount of lead in a TV or computer CRT monitor, are developed. Both an upper and a lower limit on the amount of cadmium in a nickel-cadmium battery are calculated on the basis of the battery's chemical reaction. The amount of lead shielding needed in a TV or CRT computer monitor is estimated on the basis of the potential difference through which electrons are accelerated and the absorption length of photons in lead. Such calculations can be used as benchmarks in product environmental assessments, providing validation of manufacturer-supplied data and providing insight into the composition and design of products.

  19. Direct measurement of ozone production rates in Houston in 2009 and comparison with two estimation methods

    NASA Astrophysics Data System (ADS)

    Cazorla, M.; Brune, W. H.; Ren, X.; Lefer, B.

    2012-01-01

    Net ozone production rates, P(O3), were measured directly using the Penn State Measurement of Ozone Production Sensor (MOPS) during the Study of Houston Atmospheric Radical Precursors (SHARP, 2009). Measured P(O3) peaked in the late morning, with values between 15 ppbv h-1 and 100 ppbv h-1, although values of 40-80 ppbv h-1 were typical for higher ozone days. These measurements were compared against ozone production rates calculated using measurements of hydroperoxyl (HO2), hydroxyl (OH), and nitric oxide (NO) radicals, called "calculated P(O3)". The same comparison was done using modeled radicals obtained from a box model with the RACM2 mechanism, called "modeled P(O3)". Measured and calculated P(O3) had similar peak values but the calculated P(O3) tended to peak earlier in the morning when NO values were higher. Measured and modeled P(O3) had a similar dependence on NO, but the modeled P(O3) was only half the measured P(O3). The modeled P(O3) is less than the calculated P(O3) because the modeled HO2 is less than the measured HO2. While statistical analyses are not conclusive regarding the comparison between MOPS measurements and the two estimation methods, the calculated P(O3) with measured HO2 produces peak values similar to the measured P(O3) when ozone is high. Although the MOPS is new and more testing is required to verify its observations, the measurements in the SHARP field campaign show the potential of this new technique for contributing to the understanding of ozone-producing chemistry and to the monitoring of ozone's response to future air quality regulatory actions.

  20. Dose equivalent rate constants and barrier transmission data for nuclear medicine facility dose calculations and shielding design.

    PubMed

    Kusano, Maggie; Caldwell, Curtis B

    2014-07-01

    A primary goal of nuclear medicine facility design is to keep public and worker radiation doses As Low As Reasonably Achievable (ALARA). To estimate dose and shielding requirements, one needs to know both the dose equivalent rate constants for soft tissue and barrier transmission factors (TFs) for all radionuclides of interest. Dose equivalent rate constants are most commonly calculated using published air kerma or exposure rate constants, while transmission factors are most commonly calculated using published tenth-value layers (TVLs). Values can be calculated more accurately using the radionuclide's photon emission spectrum and the physical properties of lead, concrete, and/or tissue at these energies. These calculations may be non-trivial due to the polyenergetic nature of the radionuclides used in nuclear medicine. In this paper, the effects of dose equivalent rate constant and transmission factor on nuclear medicine dose and shielding calculations are investigated, and new values based on up-to-date nuclear data and thresholds specific to nuclear medicine are proposed. To facilitate practical use, transmission curves were fitted to the three-parameter Archer equation. Finally, the results of this work were applied to the design of a sample nuclear medicine facility and compared to doses calculated using common methods to investigate the effects of these values on dose estimates and shielding decisions. Dose equivalent rate constants generally agreed well with those derived from the literature with the exception of those from NCRP 124. Depending on the situation, Archer fit TFs could be significantly more accurate than TVL-based TFs. These results were reflected in the sample shielding problem, with unshielded dose estimates agreeing well, with the exception of those based on NCRP 124, and Archer fit TFs providing a more accurate alternative to TVL TFs and a simpler alternative to full spectral-based calculations. The data provided by this paper should assist

  1. Dose equivalent rate constants and barrier transmission data for nuclear medicine facility dose calculations and shielding design.

    PubMed

    Kusano, Maggie; Caldwell, Curtis B

    2014-07-01

    A primary goal of nuclear medicine facility design is to keep public and worker radiation doses As Low As Reasonably Achievable (ALARA). To estimate dose and shielding requirements, one needs to know both the dose equivalent rate constants for soft tissue and barrier transmission factors (TFs) for all radionuclides of interest. Dose equivalent rate constants are most commonly calculated using published air kerma or exposure rate constants, while transmission factors are most commonly calculated using published tenth-value layers (TVLs). Values can be calculated more accurately using the radionuclide's photon emission spectrum and the physical properties of lead, concrete, and/or tissue at these energies. These calculations may be non-trivial due to the polyenergetic nature of the radionuclides used in nuclear medicine. In this paper, the effects of dose equivalent rate constant and transmission factor on nuclear medicine dose and shielding calculations are investigated, and new values based on up-to-date nuclear data and thresholds specific to nuclear medicine are proposed. To facilitate practical use, transmission curves were fitted to the three-parameter Archer equation. Finally, the results of this work were applied to the design of a sample nuclear medicine facility and compared to doses calculated using common methods to investigate the effects of these values on dose estimates and shielding decisions. Dose equivalent rate constants generally agreed well with those derived from the literature with the exception of those from NCRP 124. Depending on the situation, Archer fit TFs could be significantly more accurate than TVL-based TFs. These results were reflected in the sample shielding problem, with unshielded dose estimates agreeing well, with the exception of those based on NCRP 124, and Archer fit TFs providing a more accurate alternative to TVL TFs and a simpler alternative to full spectral-based calculations. The data provided by this paper should assist

  2. Testing the soil production paradigm: Role of catchment-mean erosion rate in colluvial soil production

    NASA Astrophysics Data System (ADS)

    Foster, M.; Whipple, K. X.; Heimsath, A. M.

    2013-12-01

    Colluvial soil thickness is a fundamental characteristic of the critical zone, playing an essential role in hydrology, ecology, the action of biogeochemical cycles, and erosion and transport processes. Colluvial soil thickness reflects a balance between soil production (the conversion of rock to mobile regolith) and erosion. Further, well-established theory predicts that: (1) mean soil thickness decreases with increasing catchment-mean erosion rate and (2) that soil-mantled landscapes give way to rocky ones when catchment-mean erosion rate exceeds the climate- and lithology-controlled maximum soil production rate that occurs on bare-rock surfaces or under a thin soil cover. This critical erosion rate is thus expected to be associated with a sudden and profound change in hydrology, ecology, biogeochemical processes, and erosion/sediment transport processes. Despite the pervasive acceptance of this idea, it has never been systematically tested and even casual observations reveal that it may be flawed. Indeed, a global compilation of available soil production rate constants suggests that erosion rate is the strongest control, implying that well-established theory is fundamentally incorrect. Although the efficiency of soil production is thought to be set by climate and lithology alone, recent work suggests that it increases in concert with catchment-mean erosion rates and associated changes in process dominance and landscape morphology; existing models may exaggerate changes in critical-zone properties in response to tectonic uplift. Three fundamental observations support this claim: (1) observed soil thicknesses vary little across 2 orders of magnitude variation in erosion rate in published soil-production studies; (2) soil cover persists in landscapes eroding at well above the putative soil-production "speed limit"; and (3) published estimates of the rate constant in the exponential soil-production function increases linearly with catchment-mean erosion rate

  3. Revised Production Rates for Na-22 and Mn-54 in Meteorites Using Cross Sections Measured for Neutron-induced Reactions

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.; Kim, K. J.; Reedy, R. C.

    2004-01-01

    The interactions of galactic cosmic rays (GCR) with extraterrestrial bodies produce small amounts of radionuclides and stable isotopes. The production rates of many relatively short-lived radionuclides, including 2.6-year Na-22 and 312-day Mn-54, have been measured in several meteorites collected very soon after they fell. Theoretical models used to calculate production rates for comparison with the measured values rely on input data containing good cross section measurements for all relevant reactions. Most GCR particles are protons, but secondary neutrons make most cosmogenic nuclides. Calculated production rates using only cross sections for proton-induced reactions do not agree well with measurements. One possible explanation is that the contribution to the production rate from reactions initiated by secondary neutrons produced in primary GCR interactions should be included explicitly. This, however, is difficult to do because so few of the relevant cross sections for neutron-induced reactions have been measured.

  4. Bacterial secondary production on vascular plant detritus: relationships to detritus composition and degradation rate.

    PubMed Central

    Moran, M A; Hodson, R E

    1989-01-01

    Bacterial production at the expense of vascular plant detritus was measured for three emergent plant species (Juncus effusus, Panicum hemitomon, and Typha latifolia) degrading in the littoral zone of a thermally impacted lake. Bacterial secondary production, measured as tritiated thymidine incorporation into DNA, ranged from 0.01 to 0.81 microgram of bacterial C mg of detritus-1 day-1. The three plant species differed with respect to the amount of bacterial productivity they supported per milligram of detritus, in accordance with the predicted biodegradability of the plant material based on initial nitrogen content, lignin content, and C/N ratio. Bacterial production also varied throughout the 22 weeks of in situ decomposition and was positively related to the nitrogen content and lignin content of the remaining detritus, as well as to the temperature of the lake water. Over time, production was negatively related to the C/N ratio and cellulose content of the degrading plant material. Bacterial production on degrading plant material was also calculated on the basis of plant surface area and ranged from 0.17 to 1.98 micrograms of bacterial C cm-2 day-1. Surface area-based calculations did not correlate well with either initial plant composition or changing composition of the remaining detritus during decomposition. The rate of bacterial detritus degradation, calculated from measured production of surface-attached bacteria, was much lower than the actual rate of weight loss of plant material. This discrepancy may be attributable to the importance of nonbacterial organisms in the degradation and loss of plant material from litterbags or to the microbially mediated solubilization of particulate material prior to bacterial utilization, or both. PMID:2802603

  5. A comparison of cardiac rate-pressure product and pressure-rate quotient in healthy and medically compromised patients.

    PubMed

    Campbell, R L; Langston, W G

    1995-08-01

    Healthy and medically compromised patients were studied to compare blood pressure and heart rate changes in response to stress of routine dental extractions performed while they were under local anesthesia. Thirty-nine patients divided into American Society of Anesthesiologists (ASA) I and II groups were noninvasively monitored every 5 minutes. Systolic, diastolic, and mean arterial pressures and heart rate were recorded. Rate pressure products (RPP) and pressure rate (PRQ) quotients were calculated and compared in each group. Significant results were measures of RPP greater than 12,000 and PRQ less than one. Of the 24 patients in the ASA I category, 50% demonstrated elevated RPP values, but only two of 24 had coincidental PRQ abnormalities. Of the 15 patients in the ASA II category, 80% demonstrated elevated RPP values, but two of 15 had coincidental PRQ abnormalities. Patients in the ASA II category had a higher incidence of RPP and PRQ abnormalities, as was expected. However, it is not known which of these two measures is a more sensitive indicator of increased risk associated with stimulation of the sympathetic-adrenergic axis during oral surgery performed with patients under local anesthesia. Correlation studies with continuous Holter monitoring for ST-T wave changes on electrocardiography are forthcoming.

  6. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calculations and Data Requirements § 1065.642 SSV... ranges of dilution air dewpoint versus calibration air dewpoint in Table 3 of § 1065.640, you may set...

  7. Forest turnover rates follow global and regional patterns of productivity

    USGS Publications Warehouse

    Stephenson, N.L.; van Mantgem, P.J.

    2005-01-01

    Using a global database, we found that forest turnover rates (the average of tree mortality and recruitment rates) parallel broad-scale patterns of net primary productivity. First, forest turnover was higher in tropical than in temperate forests. Second, as recently demonstrated by others, Amazonian forest turnover was higher on fertile than infertile soils. Third, within temperate latitudes, turnover was highest in angiosperm forests, intermediate in mixed forests, and lowest in gymnosperm forests. Finally, within a single forest physiognomic type, turnover declined sharply with elevation (hence with temperature). These patterns of turnover in populations of trees are broadly similar to the patterns of turnover in populations of plant organs (leaves and roots) found in other studies. Our findings suggest a link between forest mass balance and the population dynamics of trees, and have implications for understanding and predicting the effects of environmental changes on forest structure and terrestrial carbon dynamics. ??2005 Blackwell Publishing Ltd/CNRS.

  8. Linear extension rates and gross carbonate production of Acropora cervicornis at Coral Gardens, Belize.

    NASA Astrophysics Data System (ADS)

    Peeling, E.; Greer, L.; Lescinsky, H.; Humston, R.; Wirth, K. R.; Baums, I. B.; Curran, A.

    2014-12-01

    Branching Acropora coral species have fast growth and carbonate production rates, and thus have functioned as important reef-building species throughout the Pleistocene and Holocene. Recently, net carbonate production (kg CaCO3 m-2 year-1) has been recognized as an important measure of reef health, especially when monitoring endangered species, such as Acropora cervicornis. This study examines carbonate production in a thriving population of A. cervicornis at the Coral Gardens reef in Belize. Photographic surveys were conducted along five transects of A. cervicornis-dominated reefs from 2011-2014. Matching photographs from 2013 and 2014 were scaled to 1 m2 and compared to calculate 84 individual A. cervicornis linear extension rates across the reef. Linear extension rates averaged 12.4 cm/yr and were as high as 17 cm/yr in some areas of the reef. Carbonate production was calculated two ways. The first followed the standard procedure of multiplying percent live coral cover, by the linear extension rate and skeletal density. The second used the number of live coral tips per square meter in place of percent live coral multiplied by the average cross-sectional area of the branches. The standard method yielded a carbonate production rate of 113 kg CaCO3 m-2 year-1 for the reef, and the tip method yielded a rate of 6 kg m-2 year-1. We suggest that the tip method is a more accurate measure of production, because A. cervicornis grows primarily from the live tips, with only limited radial growth and resheeting over dead skeleton. While this method omits the contributions of radial growth and resheeting, and is therefore somewhat of an underestimate, our future work will quantify these aspects of growth in a more complete carbonate budget. Still, our estimate suggests a carbonate production rate per unit area of A. cervicornis that is on par with other Caribbean coral species, rather than two orders of magnitude higher as reported by Perry et al (2013). Although gross coral

  9. Universal scaling of production rates across mammalian lineages.

    PubMed

    Hamilton, Marcus J; Davidson, Ana D; Sibly, Richard M; Brown, James H

    2011-02-22

    Over many millions of years of independent evolution, placental, marsupial and monotreme mammals have diverged conspicuously in physiology, life history and reproductive ecology. The differences in life histories are particularly striking. Compared with placentals, marsupials exhibit shorter pregnancy, smaller size of offspring at birth and longer period of lactation in the pouch. Monotremes also exhibit short pregnancy, but incubate embryos in eggs, followed by a long period of post-hatching lactation. Using a large sample of mammalian species, we show that, remarkably, despite their very different life histories, the scaling of production rates is statistically indistinguishable across mammalian lineages. Apparently all mammals are subject to the same fundamental metabolic constraints on productivity, because they share similar body designs, vascular systems and costs of producing new tissue.

  10. Universal scaling of production rates across mammalian lineages

    PubMed Central

    Hamilton, Marcus J.; Davidson, Ana D.; Sibly, Richard M.; Brown, James H.

    2011-01-01

    Over many millions of years of independent evolution, placental, marsupial and monotreme mammals have diverged conspicuously in physiology, life history and reproductive ecology. The differences in life histories are particularly striking. Compared with placentals, marsupials exhibit shorter pregnancy, smaller size of offspring at birth and longer period of lactation in the pouch. Monotremes also exhibit short pregnancy, but incubate embryos in eggs, followed by a long period of post-hatching lactation. Using a large sample of mammalian species, we show that, remarkably, despite their very different life histories, the scaling of production rates is statistically indistinguishable across mammalian lineages. Apparently all mammals are subject to the same fundamental metabolic constraints on productivity, because they share similar body designs, vascular systems and costs of producing new tissue. PMID:20798111

  11. Production of carboxylates from high rate activated sludge through fermentation.

    PubMed

    Cagnetta, C; Coma, M; Vlaeminck, S E; Rabaey, K

    2016-10-01

    The aim of this work was to study the key parameters affecting fermentation of high rate activated A-sludge to carboxylates, including pH, temperature, inoculum, sludge composition and iron content. The maximum volatile fatty acids production was 141mgCg(-1) VSSfed, at pH 7. Subsequently the potential for carboxylate and methane production for A-sludge from four different plants at pH 7 and 35°C were compared. Initial BOD of the sludge appeared to be key determining carboxylate yield from A-sludge. Whereas methanogenesis could be correlated linearly to the quantity of ferric used for coagulation, fermentation did not show a dependency on iron presence. This difference may enable a strategy whereby A-stage sludge is separated to achieve fermentation, and iron dosing for phosphate removal is only implemented at the B-stage. PMID:27020399

  12. Calculated hydroxyl A2 sigma --> X2 pi (0, 0) band emission rate factors applicable to atmospheric spectroscopy

    NASA Technical Reports Server (NTRS)

    Cageao, R. P.; Ha, Y. L.; Jiang, Y.; Morgan, M. F.; Yung, Y. L.; Sander, S. P.

    1997-01-01

    A calculation of the A2 sigma --> X2 pi (0, 0) band emission rate factors and line center absorption cross sections of OH applicable to its measurement using solar resonant fluorescence in the terrestrial atmosphere is presented in this paper. The most accurate available line parameters have been used. Special consideration has been given to the solar input flux because of its highly structured Fraunhofer spectrum. The calculation for the OH atmospheric emission rate factor in the solar resonant fluorescent case is described in detail with examples and intermediate results. Results of this calculation of OH emission rate factors for individual rotational lines are on average 30% lower than the values obtained in an earlier work.

  13. 5 CFR 532.253 - Special rates or rate ranges for leader, supervisory, and production facilitating positions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Special rates or rate ranges for leader, supervisory, and production facilitating positions. 532.253 Section 532.253 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.253 Special rates or...

  14. 5 CFR 532.253 - Special rates or rate ranges for leader, supervisory, and production facilitating positions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Special rates or rate ranges for leader, supervisory, and production facilitating positions. 532.253 Section 532.253 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.253 Special rates or...

  15. 5 CFR 532.253 - Special rates or rate ranges for leader, supervisory, and production facilitating positions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Special rates or rate ranges for leader, supervisory, and production facilitating positions. 532.253 Section 532.253 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.253 Special rates or...

  16. 5 CFR 532.253 - Special rates or rate ranges for leader, supervisory, and production facilitating positions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Special rates or rate ranges for leader, supervisory, and production facilitating positions. 532.253 Section 532.253 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.253 Special rates or...

  17. 5 CFR 532.253 - Special rates or rate ranges for leader, supervisory, and production facilitating positions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Special rates or rate ranges for leader, supervisory, and production facilitating positions. 532.253 Section 532.253 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PREVAILING RATE SYSTEMS Prevailing Rate Determinations § 532.253 Special rates or...

  18. The Production Rate and Employment of Ph.D. Astronomers

    NASA Astrophysics Data System (ADS)

    Metcalfe, Travis S.

    2007-05-01

    As in many sciences, the production rate of new Ph.D. astronomers is decoupled from the global demand for trained scientists. As noted by Thronson (1991, PASP, 103, 90), overproduction appears to be built into the system, making the mathematical formulation of surplus astronomer production similar to that for industrial pollution models -- an unintended side effect of the process. Following Harris (1994, ASP Conf., 57, 12), I document the production of Ph.D. astronomers from 1990 to 2005 using the online Dissertation Abstracts database. To monitor the changing patterns of employment, I examine the number of postdoctoral, tenure-track, and other jobs advertised in the AAS Job Register during this same period. Although the current situation is clearly unsustainable, it was much worse a decade ago with nearly 7 new Ph.D. astronomers in 1995 for every new tenure-track job. While the number of new permanent positions steadily increased throughout the late 1990's, the number of new Ph.D. recipients gradually declined. After the turn of the century, the production of new astronomers leveled off, but new postdoctoral positions grew dramatically. There has also been recent growth in the number of non-tenure-track lecturer, research, and support positions. This is just one example of a larger cultural shift to temporary employment that is happening throughout society -- it is not unique to astronomy.

  19. The Production Rate and Employment of Ph.D. Astronomers

    NASA Astrophysics Data System (ADS)

    Metcalfe, Travis S.

    2008-02-01

    In an effort to encourage self-regulation of the astronomy job market, I examine the supply of, and demand for, astronomers over time. On the supply side, I document the production rate of Ph.D. astronomers from 1970 to 2006 using the UMI Dissertation Abstracts database, along with data from other independent sources. I compare the long-term trends in Ph.D. production with federal astronomy research funding over the same time period, and I demonstrate that additional funding is correlated with higher subsequent Ph.D. production. On the demand side, I monitor the changing patterns of employment using statistics about the number and types of jobs advertised in the AAS Job Register from 1984 to 2006. Finally, I assess the sustainability of the job market by normalizing this demand by the annual Ph.D. production. The most recent data suggest that there are now annual advertisements for about one postdoctoral job, half a faculty job, and half a research/support position for every new domestic Ph.D. recipient in astronomy and astrophysics. The average new astronomer might expect to hold up to 3 jobs before finding a steady position.

  20. Investigation of the diffusion of atomic fission products in UC by density functional calculations

    NASA Astrophysics Data System (ADS)

    Bévillon, Émile; Ducher, Roland; Barrachin, Marc; Dubourg, Roland

    2013-03-01

    Activation energies of U and C atoms self-diffusion in UC, as well as activation energies of hetero-diffusion of fission products (FPs) are investigated by first-principles calculations. According to a previous study which showed a likely U site occupation was favoured for all the FPs, their diffusion is restricted to the uranium sublattice of UC in the present study. In this framework, long-range displacements are only possible through a concerted mechanism with a surrounding uranium vacancy. Using the apparent formation energies of the uranium vacancy defect calculated in our previous study and the classical approach used in UO2 by Andersson et al., the activation energies of the main fission products in the various stoichiometric domains have been calculated. The results are compared to those obtained with the five frequency model applied to two representative fission products, Xe and Zr. Interestingly, despite strong differences of formalism, both models provided similar activation energies.

  1. Calculation: Values and Consumption Rates of Locally Produced Food and Tap Water for the Receptor of Interest

    SciTech Connect

    J. Bland

    2000-07-31

    This calculation produces standard statistical data on the consumption of locally produced food and tap water. The results of this calculation provide input parameters for the GENII-S (Leigh et al. 1993) computer code to support calculation of Biosphere Dose Conversion Factors (BDCF) for the nominal performance (groundwater contamination) scenario and the volcanic eruption (contamination of soil by volcanic ash deposition) scenario. The requirement and parameters for these data are identified in ''Identification Of The Critical Group (Consumption Of Locally Produced Food And Tap Water)'' (CRWMS M&O 2000a). This calculation is performed in accordance with the ''Development Plan for Calculation: Values and Consumption Rates of Locally Produced Food and Tap Water for the Receptor of Interest'' (CRWMS M&O 2000b).

  2. Mixed quantum classical calculation of proton transfer reaction rates: From deep tunneling to over the barrier regimes

    SciTech Connect

    Xie, Weiwei; Xu, Yang; Zhu, Lili; Shi, Qiang

    2014-05-07

    We present mixed quantum classical calculations of the proton transfer (PT) reaction rates represented by a double well system coupled to a dissipative bath. The rate constants are calculated within the so called nontraditional view of the PT reaction, where the proton motion is quantized and the solvent polarization is used as the reaction coordinate. Quantization of the proton degree of freedom results in a problem of non-adiabatic dynamics. By employing the reactive flux formulation of the rate constant, the initial sampling starts from the transition state defined using the collective reaction coordinate. Dynamics of the collective reaction coordinate is treated classically as over damped diffusive motion, for which the equation of motion can be derived using the path integral, or the mixed quantum classical Liouville equation methods. The calculated mixed quantum classical rate constants agree well with the results from the numerically exact hierarchical equation of motion approach for a broad range of model parameters. Moreover, we are able to obtain contributions from each vibrational state to the total reaction rate, which helps to understand the reaction mechanism from the deep tunneling to over the barrier regimes. The numerical results are also compared with those from existing approximate theories based on calculations of the non-adiabatic transmission coefficients. It is found that the two-surface Landau-Zener formula works well in calculating the transmission coefficients in the deep tunneling regime, where the crossing point between the two lowest vibrational states dominates the total reaction rate. When multiple vibrational levels are involved, including additional crossing points on the free energy surfaces is important to obtain the correct reaction rate using the Landau-Zener formula.

  3. Production of scandium-44 m and scandium-44 g with deuterons on calcium-44: cross section measurements and production yield calculations.

    PubMed

    Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V

    2015-09-01

    HIGHLIGHTS • Production of Sc-44 m, Sc-44 g and contaminants. • Experimental values determined using the stacked-foil technique. • Thick-Target production Yield (TTY) calculations. • Comparison with the TALYS code version 1.6.Among the large number of radionuclides of medical interest, Sc-44 is promising for PET imaging. Either the ground-state Sc-44 g or the metastable-state Sc-44 m can be used for such applications, depending on the molecule used as vector. This study compares the production rates of both Sc-44 states, when protons or deuterons are used as projectiles on an enriched Calcium-44 target. This work presents the first set of data for the deuteron route. The results are compared with the TALYS code. The Thick-Target production Yields of Sc-44 m and Sc-44 g are calculated and compared with those for the proton route for three different scenarios: the production of Sc-44 g for conventional PET imaging, its production for the new 3 γ imaging technique developed at the SUBATECH laboratory and the production of a Sc-44 m/Sc-44 g in vivo generator for antibody labelling.

  4. Production of scandium-44 m and scandium-44 g with deuterons on calcium-44: cross section measurements and production yield calculations.

    PubMed

    Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V

    2015-09-01

    HIGHLIGHTS • Production of Sc-44 m, Sc-44 g and contaminants. • Experimental values determined using the stacked-foil technique. • Thick-Target production Yield (TTY) calculations. • Comparison with the TALYS code version 1.6.Among the large number of radionuclides of medical interest, Sc-44 is promising for PET imaging. Either the ground-state Sc-44 g or the metastable-state Sc-44 m can be used for such applications, depending on the molecule used as vector. This study compares the production rates of both Sc-44 states, when protons or deuterons are used as projectiles on an enriched Calcium-44 target. This work presents the first set of data for the deuteron route. The results are compared with the TALYS code. The Thick-Target production Yields of Sc-44 m and Sc-44 g are calculated and compared with those for the proton route for three different scenarios: the production of Sc-44 g for conventional PET imaging, its production for the new 3 γ imaging technique developed at the SUBATECH laboratory and the production of a Sc-44 m/Sc-44 g in vivo generator for antibody labelling. PMID:26301533

  5. Chlorine-36 Production Rate Calibration by the CRONUS-Earth Project

    NASA Astrophysics Data System (ADS)

    Phillips, F. M.; Marrero, S.; Stone, J. O.; Lifton, N. A.

    2012-12-01

    Among the cosmogenic nuclides commonly used for Quaternary geochronology and geomorphology (36Cl, 10Be, 26Al, 3He, and 14C), the production rate of 36Cl has proved particularly difficult to calibrate because of the multiple nuclear reactions that lead to its production (3 major reactions and 5 minor ones). Achieving a consensus on the production constants for 36Cl has therefore been a major emphasis of the NSF-funded Cosmic Ray Produced Nuclide Systematics on Earth (CRONUS-Earth) Project. The most suitable for 36Cl calibration of the sites sampled by CRONUS-Earth proved to be ignimbrites from Younger Dryas-correlative moraines near the Quelccaya Ice Cap in Peru, basalts from the similar-aged Tabernacle Hill flow in Utah, and granodiorite boulders on a similar-aged moraine at Baboon Lakes in the Sierra Nevada, California. Production rates were estimated by minimizing 36Cl concentration residuals, with production scaled between the sites using the recently developed Lifton-Sato formulation. The scaling parameters employed were cut-off rigidity of 0 GV, solar modulation parameter of 587.4 MV, and air pressure of 1013.25 hPa; production-rate parameters obtained using this scaling approach are not directly comparable to those previously estimated using alternative scaling methods. This approach yielded sea-level high-latitude production rates of 55±2 atoms 36Cl (g Ca)-1 yr-1, 157±5 atoms 36Cl (g K)-1 yr-1, and 704±140 neutrons (g air)-1 yr-1. The results from the minimization did not meet tests for statistical significance and therefore the parameter-rate uncertainties could not be determined directly from the calibration data set. An independent secondary data set consisting of 82 samples from 16 localities and compiled from 7 separate published studies was therefore employed for this purpose. Average deviations of calculated 36Cl ages from independently determined ages increased from about 10% for samples where 36Cl production was nearly all from spallation

  6. Recombination of W19 + ions with electrons: Absolute rate coefficients from a storage-ring experiment and from theoretical calculations

    NASA Astrophysics Data System (ADS)

    Badnell, N. R.; Spruck, K.; Krantz, C.; Novotný, O.; Becker, A.; Bernhardt, D.; Grieser, M.; Hahn, M.; Repnow, R.; Savin, D. W.; Wolf, A.; Müller, A.; Schippers, S.

    2016-05-01

    Experimentally measured and theoretically calculated rate coefficients for the recombination of W19 +([Kr ] 4 d10 4 f9 ) ions with free electrons (forming W18 +) are presented. At low electron-ion collision energies, the merged-beam rate coefficient is dominated by strong, mutually overlapping, recombination resonances as already found previously for the neighboring charge-state ions W18 + and W20 +. In the temperature range where W19 + is expected to form in a collisionally ionized plasma, the experimentally derived recombination rate coefficient deviates by up to a factor of about 20 from the theoretical rate coefficient obtained from the Atomic Data and Analysis Structure database. The present calculations, which employ a Breit-Wigner redistributive partitioning of autoionizing widths for dielectronic recombination via multi-electron resonances, reproduce the experimental findings over the entire temperature range.

  7. Direct Measurement of the Unimolecular Decay Rate of Criegee Intermediates to OH Products

    NASA Astrophysics Data System (ADS)

    Liu, Fang; Fang, Yi; Klippenstein, Stephen; McCoy, Anne; Lester, Marsha

    Ozonolysis of alkenes is an important non-photolytic source of OH radicals in the troposphere. The production of OH radicals proceeds though formation and unimolecular decay of Criegee intermediates such as syn-CH3CHOO and (CH3)2COO. These alkyl-substituted Criegee intermediates can undergo a 1,4-H transfer reaction to form an energized vinyl hydroperoxide species, which breaks apart to OH and vinoxy products. Recently, this laboratory used IR excitation in the C-H stretch overtone region to initiate the unimolecular decay of syn-CH3CHOO and (CH3)2COO Criegee intermediates, leading to OH formation. Here, direct time-domain measurements are performed to observe the rate of appearance of OH products under collision-free conditions utilizing UV laser-induced fluorescence for detection. The experimental rates are in excellent agreement with statistical RRKM calculations using barrier heights predicted from high-level electronic structure calculations. Accurate determination of the rates and barrier heights for unimolecular decay of Criegee intermediates is essential for modeling the kinetics of alkene ozonolysis reactions, a significant OH radical source in atmospheric chemistry, as well as the steady-state concentration of Criegee intermediates in the atmosphere. This research was supported through the National Science Foundation under grant CHE-1362835.

  8. The effect of soil moisture on nitrous oxide production rates in large enclosed ecosystems

    NASA Astrophysics Data System (ADS)

    van Haren, J.; Colodner, D.; Lin, G.; Murthy, R.

    2001-12-01

    On land, nitrous oxide (N2O) is mainly produced in soils by bacterial processes such as nitrification and denitrification. Once in the atmosphere N2O contributes to the greenhouse effect and stratospheric ozone destruction. Nitrification and denitrification are strongly dependent on soil moisture content, amongst other soil parameters. At Biosphere 2 Center we have begun to test the utility of meso-scale closed systems for understanding the relationship between soil properties and trace gas production at larger scales. We investigated the relationship between soil moisture content and soil N2O efflux in two large experimental closed systems (Tropical Rainforest (TR) and Intensive Forestry (IF) Mesocosms) at Biosphere 2 Center. N2O was measured every hour with an automated GC system. The daily N2O production rate was calculated as the rate of increase of N2O during the daytime, when the mesocosm was materially closed. We furthermore measured N2O and nitrate concentrations in the soil, as well as nitrate and N2O production rates in local areas. In the Rainforest Mesocosm, we found a very reproducible relationship between soil moisture content and N2O efflux, including the transient spikes in production rate upon wetting. In the Forestry Mesocosm the relation between soil moisture and N2O efflux was less clearcut.

  9. Ion production rate in a boreal forest based on ion, particle and radiation measurements

    NASA Astrophysics Data System (ADS)

    Laakso, L.; Petäjä, T.; Lehtinen, K. E. J.; Kulmala, M.; Paatero, J.; Hõrrak, U.; Tammet, H.; Joutsensaari, J.

    2004-09-01

    In this study the ion production rates in a boreal forest were studied based on two different methods: 1) cluster ion and particle concentration measurements, 2) external radiation and radon concentration measurements. Both methods produced reasonable estimates for ion production rates. The average ion production rate calculated from aerosol particle size distribution and air ion mobility distribution measurements was 2.6 ion pairs cm-3s-1, and based on external radiation and radon measurements, 4.5 ion pairs cm-3s-1. The first method based on ion and particle measurements gave lower values for the ion production rates especially during the day. A possible reason for this is that particle measurements started only from 3nm, so the sink of small ions during the nucleation events was underestimated. It may also be possible that the hygroscopic growth factors of aerosol particles were underestimated. Another reason for the discrepancy is the nucleation mechanism itself. If the ions are somehow present in the nucleation process, there could have been an additional ion sink during the nucleation days.

  10. Substrate inhibition and control for high rate biogas production

    SciTech Connect

    Shin, H.S.

    1982-01-01

    This research addresses a critical aspect of the technical feasibility of biogas recovery with poultry manure using anaerobic digestion, namely, inhibition and toxicity factors limiting methane generation under high rate conditions. The research was designed to identify the limiting factors and to examine alternative pretreatment and in situ control methods for the anaerobic digestion of poultry manure as an energy producing system. Biogas production was indicated by the daily gas volume produced per unit digester capacity. Enhanced biogas generation from the anaerobic digester systems using poultry manure was studied in laboratory- and pilot-scale digester operations. It was found that ammonia nitrogen concentration above 4000 mg/l was inhibitory to biogas production. Pretreatment of the manure by elutriation was effective for decreasing inhibitory/toxic conditions. Increased gas production resulted without an indication of serious inhibition by increased volatile acids, indicating a limitation of available carbon sources. For poultry manure digestion, the optimum pH range was 7.1 to 7.6. Annual costs for pretreatment/biogas systems for 10,000, 30,000 and 50,000 birds were estimated and compared with annual surplus energy produced. The economic break-even point was achieved in digesters for greater than 30,000 birds. Capital cost of the digester system was estimated to be $18,300 with annual costs around $4000. It is anticipated that the digester system could be economically applied to smaller farms as energy costs increase.

  11. 42 CFR 412.624 - Methodology for calculating the Federal prospective payment rates.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... made under part 413 of this subchapter; (2) An appropriate wage index to adjust for area wage... differences in the area wage levels using an appropriate wage index. The application of the wage index is made... CMS calculates a single overall (combined operating and capital) cost-to-charge ratio and...

  12. Fission Product Decay Heat Calculations for Neutron Fission of 232Th

    NASA Astrophysics Data System (ADS)

    Son, P. N.; Hai, N. X.

    2016-06-01

    Precise information on the decay heat from fission products following times after a fission reaction is necessary for safety designs and operations of nuclear-power reactors, fuel storage, transport flasks, and for spent fuel management and processing. In this study, the timing distributions of fission products' concentrations and their integrated decay heat as function of time following a fast neutron fission reaction of 232Th were exactly calculated by the numerical method with using the DHP code.

  13. Regional Contrasts of the Warming Rate over Land Significantly Depend on the Calculation Methods of Mean Air Temperature

    NASA Astrophysics Data System (ADS)

    Wang, Kaicun; Zhou, Chunlüe

    2016-04-01

    Global analyses of surface mean air temperature (Tm) are key datasets for climate change studies and provide fundamental evidences for global warming. However, the causes of regional contrasts in the warming rate revealed by such datasets, i.e., enhanced warming rates over the northern high latitudes and the "warming hole" over the central U.S., are still under debate. Here we show these regional contrasts depends on the calculation methods of Tm. Existing global analyses calculated Tm from daily minimum and maximum temperatures (T2). We found that T2 has a significant standard deviation error of 0.23 °C/decade in depicting the regional warming rate from 2000 to 2013 but can be reduced by two-thirds using Tm calculated from observations at four specific times (T4), which samples diurnal cycle of land surface air temperature more often. From 1973 to 1997, compared with T4, T2 significantly underestimated the warming rate over the central U.S. and overestimated the warming rate over the northern high latitudes. The ratio of the warming rate over China to that over the U.S. reduces from 2.3 by T2 to 1.4 by T4. This study shows that the studies of regional warming can be substantially improved by T4 instead of T2.

  14. Regional Contrasts of the Warming Rate over Land Significantly Depend on the Calculation Methods of Mean Air Temperature.

    PubMed

    Wang, Kaicun; Zhou, Chunlüe

    2015-01-01

    Global analyses of surface mean air temperature (T(m)) are key datasets for climate change studies and provide fundamental evidences for global warming. However, the causes of regional contrasts in the warming rate revealed by such datasets, i.e., enhanced warming rates over the northern high latitudes and the "warming hole" over the central U.S., are still under debate. Here we show these regional contrasts depend on the calculation methods of T(m). Existing global analyses calculate T(m) from daily minimum and maximum temperatures (T2). We found that T2 has a significant standard deviation error of 0.23 °C/decade in depicting the regional warming rate from 2000 to 2013 but can be reduced by two-thirds using T(m) calculated from observations at four specific times (T4), which samples diurnal cycle of land surface air temperature more often. From 1973 to 1997, compared with T4, T2 significantly underestimated the warming rate over the central U.S. and overestimated the warming rate over the northern high latitudes. The ratio of the warming rate over China to that over the U.S. reduces from 2.3 by T2 to 1.4 by T4. This study shows that the studies of regional warming can be substantially improved by T4 instead of T2. PMID:26198976

  15. Regional Contrasts of the Warming Rate over Land Significantly Depend on the Calculation Methods of Mean Air Temperature.

    PubMed

    Wang, Kaicun; Zhou, Chunlüe

    2015-07-22

    Global analyses of surface mean air temperature (T(m)) are key datasets for climate change studies and provide fundamental evidences for global warming. However, the causes of regional contrasts in the warming rate revealed by such datasets, i.e., enhanced warming rates over the northern high latitudes and the "warming hole" over the central U.S., are still under debate. Here we show these regional contrasts depend on the calculation methods of T(m). Existing global analyses calculate T(m) from daily minimum and maximum temperatures (T2). We found that T2 has a significant standard deviation error of 0.23 °C/decade in depicting the regional warming rate from 2000 to 2013 but can be reduced by two-thirds using T(m) calculated from observations at four specific times (T4), which samples diurnal cycle of land surface air temperature more often. From 1973 to 1997, compared with T4, T2 significantly underestimated the warming rate over the central U.S. and overestimated the warming rate over the northern high latitudes. The ratio of the warming rate over China to that over the U.S. reduces from 2.3 by T2 to 1.4 by T4. This study shows that the studies of regional warming can be substantially improved by T4 instead of T2.

  16. Buyer-vendor coordination for fixed lifetime product with quantity discount under finite production rate

    NASA Astrophysics Data System (ADS)

    Zhang, Qinghong; Luo, Jianwen; Duan, Yongrui

    2016-03-01

    Buyer-vendor coordination has been widely addressed; however, the fixed lifetime of the product is seldom considered. In this paper, we study the coordination of an integrated production-inventory system with quantity discount for a fixed lifetime product under finite production rate and deterministic demand. We first derive the buyer's ordering policy and the vendor's production batch size in decentralised and centralised systems. We then compare the two systems and show the non-coordination of the ordering policies and the production batch sizes. To improve the supply chain efficiency, we propose quantity discount contract and prove that the contract can coordinate the buyer-vendor supply chain. Finally, we present analytically tractable solutions and give a numerical example to illustrate the benefits of the proposed quantity discount strategy.

  17. Calculation of reaction rate constants using approximate evolution of quantum trajectories in imaginary and real time

    NASA Astrophysics Data System (ADS)

    Garashchuk, Sophya

    2010-05-01

    Reaction rate constants can be directly obtained from evolution of the flux operator eigenvectors under the Boltzmann and Hamiltonian operators. This is achieved by evolving the quantum trajectory ensemble, representing a wavefunction, in imaginary time seamlessly switching to the real-time dynamics. Quantum-mechanical effects are incorporated through the quantum potential dependent on the trajectory momenta or on the derivatives of the wavefunction amplitude. For practicality the quantum potential and wavefunction nodes are described using linear basis, which is exact for Gaussian wavefunctions. For the Eckart barrier approximate rate constants show significant improvement over the parabolic barrier rate constants.

  18. 39 CFR 3010.22 - Calculation of annual limitation when notices of rate adjustment are less than 12 months apart.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dividing the sum by 12 (Recent Average). The partial year limitation is then calculated by dividing the Recent Average by the Recent Average from the most recent previous notice of rate adjustment (Previous Recent Average) applicable to each affected class of mail and subtracting 1 from the quotient. The...

  19. Numerical calculation of protein-ligand binding rates through solution of the Smoluchowski equation using smoothed particle hydrodynamics

    SciTech Connect

    Pan, Wenxiao; Daily, Michael; Baker, Nathan A.

    2015-05-07

    Background: The calculation of diffusion-controlled ligand binding rates is important for understanding enzyme mechanisms as well as designing enzyme inhibitors. Methods: We demonstrate the accuracy and effectiveness of a Lagrangian particle-based method, smoothed particle hydrodynamics (SPH), to study diffusion in biomolecular systems by numerically solving the time-dependent Smoluchowski equation for continuum diffusion. Unlike previous studies, a reactive Robin boundary condition (BC), rather than the absolute absorbing (Dirichlet) BC, is considered on the reactive boundaries. This new BC treatment allows for the analysis of enzymes with “imperfect” reaction rates. Results: The numerical method is first verified in simple systems and then applied to the calculation of ligand binding to a mouse acetylcholinesterase (mAChE) monomer. Rates for inhibitor binding to mAChE are calculated at various ionic strengths and compared with experiment and other numerical methods. We find that imposition of the Robin BC improves agreement between calculated and experimental reaction rates. Conclusions: Although this initial application focuses on a single monomer system, our new method provides a framework to explore broader applications of SPH in larger-scale biomolecular complexes by taking advantage of its Lagrangian particle-based nature.

  20. 75 FR 20373 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-19

    ....C. 1505 and Treasury Decision 85-93, published in the Federal Register on May 29, 1985 (50 FR 21832... Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of Homeland... Service interest rates used to calculate interest on overdue accounts (underpayments) and...

  1. 76 FR 2404 - Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ....C. 1505 and Treasury Decision 85-93, published in the Federal Register on May 29, 1985 (50 FR 21832... Accounts and Refunds on Customs Duties AGENCY: Customs and Border Protection, Department of Homeland... Service interest rates used to calculate interest on overdue accounts (underpayments) and...

  2. Multiple-estimate Monte Carlo calculation of the dose rate constant for a cesium-131 interstitial brachytherapy seed

    SciTech Connect

    Wittman, Richard S.; Fisher, Darrell R.

    2007-01-03

    The purpose of this study was to calculate a more accurate dose rate constant for the Cs-131 (model CS-1, IsoRay Medical, Inc., Richland, Washington) interstitial brachytherapy seed. Previous measurements of the dose rate constant for this seed have been reported by others with incongruity. Recent direct measurements by thermoluminescence dosimetry and by gamma-ray spectroscopy were about 15 percent greater than earlier thermoluminescence dosimetry measurements. Therefore, we set about to calculate independent values by a Monte Carlo approach that combined three estimates as a consistency check, and to quantify the computational uncertainty. The calculated dose rate constant for the Cs-131 seed was 1.040 cGy h^{-1} U^{-1} for an ionization chamber model and 1.032 cGy h^{-1} U^{-1} for a circular ring model. A formal value of 2.2% uncertainty was calculated for both values. The range of our multi-estimate values were from 1.032 cGy h^{-1} U^{-1} to 1.061 cGy h^{-1} U^{-1}. We also modeled three I-125 seeds with known dose rate constants to test the accuracy of this study's approach.

  3. Numerical calculation of protein-ligand binding rates through solution of the Smoluchowski equation using smoothed particle hydrodynamics

    DOE PAGES

    Pan, Wenxiao; Daily, Michael; Baker, Nathan A.

    2015-05-07

    Background: The calculation of diffusion-controlled ligand binding rates is important for understanding enzyme mechanisms as well as designing enzyme inhibitors. Methods: We demonstrate the accuracy and effectiveness of a Lagrangian particle-based method, smoothed particle hydrodynamics (SPH), to study diffusion in biomolecular systems by numerically solving the time-dependent Smoluchowski equation for continuum diffusion. Unlike previous studies, a reactive Robin boundary condition (BC), rather than the absolute absorbing (Dirichlet) BC, is considered on the reactive boundaries. This new BC treatment allows for the analysis of enzymes with “imperfect” reaction rates. Results: The numerical method is first verified in simple systems and thenmore » applied to the calculation of ligand binding to a mouse acetylcholinesterase (mAChE) monomer. Rates for inhibitor binding to mAChE are calculated at various ionic strengths and compared with experiment and other numerical methods. We find that imposition of the Robin BC improves agreement between calculated and experimental reaction rates. Conclusions: Although this initial application focuses on a single monomer system, our new method provides a framework to explore broader applications of SPH in larger-scale biomolecular complexes by taking advantage of its Lagrangian particle-based nature.« less

  4. Calculations of rate constants for the three-body recombination of H2 in the presence of H2

    NASA Technical Reports Server (NTRS)

    Schwenke, David W.

    1988-01-01

    A new global potential energy hypersurface for H2 + H2 is constructed and quasiclassical trajectory calculations performed using the resonance complex theory and energy transfer mechanism to estimate the rate of three body recombination over the temperature range 100 to 5000 K. The new potential is a faithful representation of ab initio electron structure calculations, is unchanged under the operation of exchanging H atoms, and reproduces the accurate H3 potential as one H atom is pulled away. Included in the fitting procedure are geometries expected to be important when one H2 is near or above the dissociation limit. The dynamics calculations explicitly include the motion of all four atoms and are performed efficiently using a vectorized variable-stepsize integrator. The predicted rate constants are approximately a factor of two smaller than experimental estimates over a broad temperature range.

  5. Semi-Classical Calculations of Ultracold Collisions with Frequency-Chirped Light: Dependence on Chirp Rate

    NASA Astrophysics Data System (ADS)

    Wright, Matthew

    2014-05-01

    We conduct semi-classical monte-carlo simulations of ultracold collisions utilizing frequency-chirped laser light on the nanosecond timescale. Previous work revealed partial control of light-assisted collisional mechanisms with relatively slow chirp rates (10 GHz/ μs). Collisions induced with positive chirped light enhance the inelastic collisional loss rate of atoms from a magneto-optical trap whereas these trap loss collisions can be blocked when negative chirped light is used. Early quantum and classical simulations show that for negative chirps the laser's frequency continually interacts with the atom-pair during the collision. We investigate how this process depends on the chirp rate and show that by moderately speeding up the chirp (> 50 GHz/ μs), we can significantly enhance the difference in the collisional loss rate induced by the negative and positive chirps, gaining nearly full control of the collision.

  6. Program for PET image alignment: Effects on calculated differences in cerebral metabolic rates for glucose

    SciTech Connect

    Phillips, R.L.; London, E.D.; Links, J.M.; Cascella, N.G. )

    1990-12-01

    A program was developed to align positron emission tomography images from multiple studies on the same subject. The program allowed alignment of two images with a fineness of one-tenth the width of a pixel. The indications and effects of misalignment were assessed in eight subjects from a placebo-controlled double-blind crossover study on the effects of cocaine on regional cerebral metabolic rates for glucose. Visual examination of a difference image provided a sensitive and accurate tool for assessing image alignment. Image alignment within 2.8 mm was essential to reduce variability of measured cerebral metabolic rates for glucose. Misalignment by this amount introduced errors on the order of 20% in the computed metabolic rate for glucose. These errors propagate to the difference between metabolic rates for a subject measured in basal versus perturbed states.

  7. Estimation of HF artificial ionospheric turbulence characteristics using comparison of calculated plasma wave decay rates with the measured decay rates of the stimulated electromagnetic emission

    NASA Astrophysics Data System (ADS)

    Bareev, D. D.; Gavrilenko, V. G.; Grach, S. M.; Sergeev, E. N.

    2016-02-01

    It is shown experimentally that the relaxation time of the stimulated electromagnetic emission (SEE) after the pump wave turn off decreases when frequency of the electromagnetic wave, responsible for the SEE generation (pump wave f0 or diagnostic wave fdw) approaches 4th harmonic of the electron cyclotron frequency fce . Since the SEE relaxation is determined by the damping rate of plasma waves with the same frequency, responsible for the SEE generation, we calculated damping rates of plasma waves with ω ∼ωuh (ω is the plasma wave frequency, ωuh is the upper hybrid frequency) for frequencies close to and distant from the double resonance where ωuh ∼ 4ωce (ωce = 2 πfce). The calculations were performed numerically on the base of linear plasma wave dispersion relation at arbitrary ratio between | Δ | = ω - 4ωce and |k‖ |VTe (VTe is the electron thermal speed and k‖ is the projection of the wave vector onto the magnetic field direction. A comparison of calculation and experimental results has shown that obtained frequency dependence of the SEE decay rate is similar to the damping rate frequency dependence for plasma waves with wave vectors directed at the angles 60-70° to the magnetic field, and gives a strong hint that oblique upper hybrid plasma waves should be responsible for the SEE generation.

  8. Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations

    SciTech Connect

    Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa

    2005-05-24

    The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

  9. Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations

    NASA Astrophysics Data System (ADS)

    Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa

    2005-05-01

    The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

  10. Concentrations, metabolic clearance rates, production rates and plasma binding of cortisol in Antarctic phocid seals.

    PubMed

    Liggins, G C; France, J T; Schneider, R C; Knox, B S; Zapol, W M

    1993-10-01

    We have reported previously that plasma of the Weddell seal, a member of the phocid family, contains a very high concentration of cortisol. The present study was undertaken to determine whether high cortisol levels were common to seals in the Antarctic environment, or to other phocidae, and to determine the mechanism of the hypercortisolaemia. High levels of cortisol (0.82-2.38 mumol/l) were found in 4 phocidae (Weddell, crabeater, leopard and Southern elephant seals), whereas levels in a member of the otariid family (Antarctic fur seal) were similar to human values. Metabolic clearance rates (MCR) and production rates (PR) of cortisol were determined in the field in Weddell (N = 1), crabeater (N = 3) and leopard (N = 3) seals following bolus injections of [3H] cortisol. The MCR and PR did not differ between the three phocids, but whereas the MCR of 410-590 1/day was twice that of human values, the PR of 460-1180 mumol.m-2 x d-1 was up to 40-fold greater. The binding capacity of corticosteroid-binding globulin (CBG) was equal to or greater than the plasma concentrations of cortisol, resulting in relatively low concentrations of free cortisol. We conclude that hypercortisolaemia is maintained in phocid seals mainly by a high production rate--the highest (corrected for surface area) reported in any species. The relatively low cortisol levels in otariid seals studied in the same environment suggest that the high PR in phocidae is unrelated to the harsh climatic conditions, but may be part of their adaptation for diving to extreme depths.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Hot-electron-mediated desorption rates calculated from excited-state potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Olsen, Thomas; Gavnholt, Jeppe; Schiøtz, Jakob

    2009-01-01

    We present a model for desorption induced by (multiple) electronic transitions [DIET (DIMET)] based on potential energy surfaces calculated with the delta self-consistent field extension of density-functional theory. We calculate potential energy surfaces of CO and NO molecules adsorbed on various transition-metal surfaces and show that classical nuclear dynamics does not suffice for propagation in the excited state. We present a simple Hamiltonian describing the system with parameters obtained from the excited-state potential energy surface and show that this model can describe desorption dynamics in both the DIET and DIMET regimes and reproduce the power-law behavior observed experimentally. We observe that the internal stretch degree of freedom in the molecules is crucial for the energy transfer between the hot electrons and the molecule when the coupling to the surface is strong.

  12. Structure-activity correlations for organophosphorus ester anticholinesterases. Part 2: CNDO/2 calculations applied to ester hydrolysis rates

    NASA Technical Reports Server (NTRS)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1984-01-01

    Quantitative structure-activity relationships are presented for the hydrolysis of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. CNDO/2 calculations provide values for molecular parameters that correlate with alkaline hydrolysis rates. For each subset of esters with the same leaving group, X, the CNDO-derived net atomic charge at the central phosphorus atom correlates well with the alkaline hydrolysis rate constants. For the whole set of esters with different leaving groups, equations are derived that relate charge, orbital energy and bond order to the hydrolysis rate constants.

  13. 78 FR 39784 - International Product Change-Priority Mail International Regional Rate Boxes-Non-Published Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... Product Change--Priority Mail International Regional Rate Boxes--Non-Published Rates AGENCY: Postal... with the Postal Regulatory Commission to add Priority Mail International Regional Rate Boxes--Non... the Postal Regulatory Commission: (1) A request to add Priority Mail International Regional Rate...

  14. 50 CFR Table 3 to Part 679 - Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut 3 Table 3 to Part 679 Wildlife and Fisheries FISHERY... Rates for Groundfish Species and Conversion Rates for Pacific Halibut ER28JA02.074 ER10JY02.000...

  15. Production rates of terrestrial in-situ-produced cosmogenic nuclides

    SciTech Connect

    Reedy, R.C.; Tuniz, C.; Fink, D.

    1993-12-31

    Production rates of cosmogenic nuclides made in situ in terrestrial samples and how they are applied to the interpretation of measured radionuclide concentrations were discussed at a one-day Workshop held 2 October 1993 in Sydney, Australia. The status of terrestrial in-situ studies using the long-lived radionuclides {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, and {sup 41}Ca and of various modeling and related studies were presented. The relative uncertainties in the various factors that go into the interpretation of these terrestrial in-situ cosmogenic nuclides were discussed. The magnitudes of the errors for these factors were estimated and none dominated the final uncertainty.

  16. Calculation of strain-energy release rates with higher order and singular finite elements

    NASA Technical Reports Server (NTRS)

    Raju, I. S.

    1987-01-01

    A general finite element procedure for obtaining strain-energy release rates for crack growth in isotropic materials is presented. The procedure is applicable to two-dimensional finite element analyses and uses the virtual crack-closure method. The procedure was applied to nonsingular 4-noded (linear), 8-noded (parabolic), and 12-noded (cubic) elements and to quarter-point and cubic singularity elements. Simple formulas for strain-energy release rates were obtained with this procedure for both nonsingular and singularity elements. The formulas were evaluated by applying them to two mode I and two mixed mode problems. Comparisons with results from the literature for these problems showed that the formulas give accurate strain-energy release rates.

  17. Reaction of limonene with F2: rate coefficient and products.

    PubMed

    Bedjanian, Yuri; Romanias, Manolis N; Morin, Julien

    2014-11-01

    The kinetics of the reaction of limonene (C10H16) with F2 has been studied using a low pressure (P = 1 Torr) and a high pressure turbulent (P = 100 Torr) flow reactor coupled with an electron impact ionization and chemical ionization mass spectrometers, respectively: F2 + Limonene → products (1). The rate constant of the title reaction was determined under pseudo-first-order conditions by monitoring either limonene or F2 decay in excess of F2 or C10H16, respectively. The reaction rate constant, k1 = (1.15 ± 0.25) × 10(-12) exp(160 ± 70)/T) was determined over the temperature range 278-360 K, independent of pressure between 1 (He) and 100 (N2) Torr. F atom and HF were found to be formed in reaction 1 , with the yields of 0.60 ± 0.13 and 0.39 ± 0.09, respectively, independent of temperature in the range 296-355 K.

  18. Recent developments in cosmogenic nuclide production rate scaling

    NASA Astrophysics Data System (ADS)

    Lifton, N. A.

    2013-12-01

    A new cosmogenic nuclide production rate scaling model based on analytical fits to Monte Carlo simulations of atmospheric cosmic ray flux spectra (both of which agree well with measured spectra) enables identification and quantification of the biases in previously published models (Lifton, N., Sato, T., Dunai, T., in review, Earth and Planet. Sci. Lett.). Scaling predictions derived from the new model (termed LSD) suggest two potential sources of bias in the previous models: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. In addition, the particle flux spectra generated by the LSD model allow one to generate nuclide-specific scaling factors that reflect the influences of the flux energy distribution and the relevant excitation functions (probability of nuclide production in a given nuclear reaction as a function of energy). Resulting scaling factors indicate 3He shows the strongest positive deviation from the flux-based scaling, while 14C exhibits a negative deviation. These results are consistent with previous studies showing an increasing 3He/10Be ratio with altitude in the Himalayas, but with a much lower magnitude for the effect. Furthermore, the new model provides a flexible framework for exploring the implications of future advances in model inputs. For example, the effects of recently updated paleomagnetic models (e.g. Korte et al., 2011, Earth and Planet Sci. Lett. 312, 497-505) on scaling predictions will also be presented.

  19. Enhancing microalgal photosynthesis and productivity in wastewater treatment high rate algal ponds for biofuel production.

    PubMed

    Sutherland, Donna L; Howard-Williams, Clive; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J

    2015-05-01

    With microalgal biofuels currently receiving much attention, there has been renewed interest in the combined use of high rate algal ponds (HRAP) for wastewater treatment and biofuel production. This combined use of HRAPs is considered to be an economically feasible option for biofuel production, however, increased microalgal productivity and nutrient removal together with reduced capital costs are needed before it can be commercially viable. Despite HRAPs being an established technology, microalgal photosynthesis and productivity is still limited in these ponds and is well below the theoretical maximum. This paper critically evaluates the parameters that limit microalgal light absorption and photosynthesis in wastewater HRAPs and examines biological, chemical and physical options for improving light absorption and utilisation, with the view of enhancing biomass production and nutrient removal.

  20. The mechanics of granitoid systems and maximum entropy production rates.

    PubMed

    Hobbs, Bruce E; Ord, Alison

    2010-01-13

    A model for the formation of granitoid systems is developed involving melt production spatially below a rising isotherm that defines melt initiation. Production of the melt volumes necessary to form granitoid complexes within 10(4)-10(7) years demands control of the isotherm velocity by melt advection. This velocity is one control on the melt flux generated spatially just above the melt isotherm, which is the control valve for the behaviour of the complete granitoid system. Melt transport occurs in conduits initiated as sheets or tubes comprising melt inclusions arising from Gurson-Tvergaard constitutive behaviour. Such conduits appear as leucosomes parallel to lineations and foliations, and ductile and brittle dykes. The melt flux generated at the melt isotherm controls the position of the melt solidus isotherm and hence the physical height of the Transport/Emplacement Zone. A conduit width-selection process, driven by changes in melt viscosity and constitutive behaviour, operates within the Transport Zone to progressively increase the width of apertures upwards. Melt can also be driven horizontally by gradients in topography; these horizontal fluxes can be similar in magnitude to vertical fluxes. Fluxes induced by deformation can compete with both buoyancy and topographic-driven flow over all length scales and results locally in transient 'ponds' of melt. Pluton emplacement is controlled by the transition in constitutive behaviour of the melt/magma from elastic-viscous at high temperatures to elastic-plastic-viscous approaching the melt solidus enabling finite thickness plutons to develop. The system involves coupled feedback processes that grow at the expense of heat supplied to the system and compete with melt advection. The result is that limits are placed on the size and time scale of the system. Optimal characteristics of the system coincide with a state of maximum entropy production rate.

  1. 42 CFR 419.32 - Calculation of prospective payment rates for hospital outpatient services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... hospital outpatient services. 419.32 Section 419.32 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEM FOR HOSPITAL OUTPATIENT DEPARTMENT SERVICES Basic Methodology for Determining Prospective Payment Rates for...

  2. Should thermostatted ring polymer molecular dynamics be used to calculate thermal reaction rates?

    SciTech Connect

    Hele, Timothy J. H.; Suleimanov, Yury V.

    2015-08-21

    We apply Thermostatted Ring Polymer Molecular Dynamics (TRPMD), a recently proposed approximate quantum dynamics method, to the computation of thermal reaction rates. Its short-time transition-state theory limit is identical to rigorous quantum transition-state theory, and we find that its long-time limit is independent of the location of the dividing surface. TRPMD rate theory is then applied to one-dimensional model systems, the atom-diatom bimolecular reactions H + H{sub 2}, D + MuH, and F + H{sub 2}, and the prototypical polyatomic reaction H + CH{sub 4}. Above the crossover temperature, the TRPMD rate is virtually invariant to the strength of the friction applied to the internal ring-polymer normal modes, and beneath the crossover temperature the TRPMD rate generally decreases with increasing friction, in agreement with the predictions of Kramers theory. We therefore find that TRPMD is approximately equal to, or less accurate than, ring polymer molecular dynamics for symmetric reactions, and for certain asymmetric systems and friction parameters closer to the quantum result, providing a basis for further assessment of the accuracy of this method.

  3. Challenges in Calculating Two-Year College Student Transfer Rates to Four-Year Colleges

    ERIC Educational Resources Information Center

    Sylvia, Christine L.; Song, Chunyan; Waters, Tony

    2010-01-01

    Two-year colleges play an important role in facilitating transfers to four-year institutions. This has resulted in the demand to assess how well the community college systems train students for successful transfer to four-year bachelor-granting institutions. Existing datasets on two-year college transfer rates provides inconsistent and, sometimes,…

  4. 77 FR 8101 - Antidumping Proceedings: Calculation of the Weighted-Average Dumping Margin and Assessment Rate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... Dumping Margin and Assessment Rate in Certain Antidumping Duty Proceedings, 75 FR 81533 (December 28, 2010... Duty Proceedings, 76 FR 5518 (Feb. 1, 2011). In September, 2011, pursuant to section 123(g)(1)(D) of..., 71 FR 77722 (Dec. 27, 2006) (``Final Modification for Investigations''). The Department has...

  5. The production rate of cosmogenic 21-Ne in chondrites deduced from 81-Kr measurements

    NASA Technical Reports Server (NTRS)

    Schultz, L.; Freundel, M.

    1986-01-01

    Cosmogenic Ne-21 is used widely to calculate exposure ages of stone meteorites. In order to do so, the production rate P(21) must be known. This rate, however, is dependent on the chemical composition of the meteorite as well as the mass of, and position within, the meteoroid during its exposure to the cosmic radiation. Even for a mean shielding the production rates determined from measurments of different radionuclides vary by a factor of two. A method that can be used to determine exposure ages of meteorites that avoids shielding and chemical composition corrections is the -81-Kr-Kr-method. However, for chondrites, in many cases, the direct determination of production rates for the Kr isotopes is prevented by the trapped gases and the neutron effects on bromine. Therefore, this method was applied to four eucrite falls and then their 81-Kr-83-Kr-ages were compared to their cosmogenic Ne-21 and Ar-38 concentrations. The eucrites Bouvante-le-Haut, Juvinas, Sioux County, and Stannern were chosen for these measurements because of their similar chemical composition regarding the major elements.

  6. Variation in the production rate of biosonar signals in freshwater porpoises.

    PubMed

    Kimura, Satoko; Akamatsu, Tomonari; Wang, Ding; Li, Songhai; Wang, Kexiong; Yoda, Ken

    2013-05-01

    The biosonar (click train) production rate of ten Yangtze finless porpoises and their behavior were examined using animal-borne data loggers. The sound production rate varied from 0 to 290 click trains per 10-min time interval. Large individual differences were observed, regardless of body size. Taken together, however, sound production did not differ significantly between daytime and nighttime. Over the 172.5 h of analyzed recordings, an average of 99.0% of the click trains were produced within intervals of less than 60 s, indicating that during a 1-min interval, the number of click trains produced by each porpoise was typically greater than one. Most of the porpoises exhibited differences in average swimming speed and depth between day and night. Swimming speed reductions and usage of short-range sonar, which relates to prey-capture attempts, were observed more often during nighttime. However, biosonar appears to be affected not only by porpoise foraging, but also by their sensory environment, i.e., the turbid Yangtze River system. These features will be useful for passive acoustic detection of the porpoises. Calculations of porpoise density or abundance should be conducted carefully because large individual differences in the sound production rate will lead to large estimation error.

  7. Improved Ionospheric Electrodynamic Models and Application to Calculating Joule Heating Rates

    NASA Technical Reports Server (NTRS)

    Weimer, D. R.

    2004-01-01

    Improved techniques have been developed for empirical modeling of the high-latitude electric potentials and magnetic field aligned currents (FAC) as a function of the solar wind parameters. The FAC model is constructed using scalar magnetic Euler potentials, and functions as a twin to the electric potential model. The improved models have more accurate field values as well as more accurate boundary locations. Non-linear saturation effects in the solar wind-magnetosphere coupling are also better reproduced. The models are constructed using a hybrid technique, which has spherical harmonic functions only within a small area at the pole. At lower latitudes the potentials are constructed from multiple Fourier series functions of longitude, at discrete latitudinal steps. It is shown that the two models can be used together in order to calculate the total Poynting flux and Joule heating in the ionosphere. An additional model of the ionospheric conductivity is not required in order to obtain the ionospheric currents and Joule heating, as the conductivity variations as a function of the solar inclination are implicitly contained within the FAC model's data. The models outputs are shown for various input conditions, as well as compared with satellite measurements. The calculations of the total Joule heating are compared with results obtained by the inversion of ground-based magnetometer measurements. Like their predecessors, these empirical models should continue to be a useful research and forecast tools.

  8. Comparisons of Neutron Cross Sections and Isotopic Composition Calculations for Fission-Product Evaluations

    NASA Astrophysics Data System (ADS)

    Kim, Do Heon; Gil, Choong-Sup; Chang, Jonghwa; Lee, Yong-Deok

    2005-05-01

    The neutron absorption cross sections for 18 fission products evaluated within the framework of the KAERI (Korea Atomic Energy Research Institute)-BNL (Brookhaven National Laboratory) international collaboration have been compared with ENDF/B-VI.7. Also, the influence of the new evaluations on the isotopic composition calculations of the fission products has been estimated through the OECD/NEA burnup credit criticality benchmarks (Phase 1B) and the LWR/Pu recycling benchmarks. These calculations were performed by WIMSD-5B with the 69-group libraries prepared from three evaluated nuclear data libraries: ENDF/B-VI.7, ENDF/B-VI.8 including the new evaluations in the resonance region covering the thermal region, and the expected ENDF/B-VII including those in the upper resonance region up to 20 MeV. For Xe-131, the composition calculated with ENDF/B-VI.8 shows a maximum difference of 5.02% compared to ENDF/B-VI.7. However, the isotopic compositions of all the fission products calculated with the expected ENDF/B-VII show no differences when compared to ENDF/B-VI.7 for the thermal reactor benchmark cases.

  9. Comparison of calculated and experimental thermal attachment rate constants for SF6 in the temperature range 200-600 K

    NASA Technical Reports Server (NTRS)

    Orient, O. J.; Chutjian, A.

    1986-01-01

    Electron-attachment cross sections are calcualted for the process e(-) + SF6 yields SF6(-) in the energy range 1-200 meV. An electron scattering approximation is used in which diatomiclike potential energy curves near the equilibrium SF6 ground state are constructed from recent spectroscopic data. Excellent agreement is found over the entire energy range with experimental attachment cross sections at a temperature of 300 K for s-wave (l = 0) scattering. The same calculation, with appropriate adjustment of the thermal populations, is used to calculate attachment rate constants in the range 50-600 K for both s- and p-wave scattering.

  10. Associated Higgs-W-Boson Production at Hadron Colliders: A Fully Exclusive QCD Calculation at NNLO

    SciTech Connect

    Ferrera, Giancarlo; Grazzini, Massimiliano; Tramontano, Francesco

    2011-10-07

    We consider QCD radiative corrections to standard model Higgs-boson production in association with a W boson in hadron collisions. We present a fully exclusive calculation up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. To perform this NNLO computation, we use a recently proposed version of the subtraction formalism. Our calculation includes finite-width effects, the leptonic decay of the W boson with its spin correlations, and the decay of the Higgs boson into a bb pair. We present selected numerical results at the Tevatron and the LHC.

  11. Calculation of laminar heating rates on three-dimensional configurations using the axisymmetric analogue

    NASA Technical Reports Server (NTRS)

    Hamilton, H. H., II

    1980-01-01

    A theoretical method was developed for computing approximate laminar heating rates on three dimensional configurations at angle of attack. The method is based on the axisymmetric analogue which is used to reduce the three dimensional boundary layer equations along surface streamlines to an equivalent axisymmetric form by using the metric coefficient which describes streamline divergence (or convergence). The method was coupled with a three dimensional inviscid flow field program for computing surface streamline paths, metric coefficients, and boundary layer edge conditions.

  12. A simple method for calculating growth rates of petroleum hydrocarbon plumes

    USGS Publications Warehouse

    Bekins, B.A.; Cozzarelli, I.M.; Curtis, G.P.

    2005-01-01

    Consumption of aquifer Fe(III) during biodegradation of ground water contaminants may result in expansion of a contaminant plume, changing the outlook for monitored natural attenuation. Data from two research sites contaminated with petroleum hydrocarbons show that toluene and xylenes degrade under methanogenic conditions, but the benzene and ethylbenzene plumes grow as aquifer Fe(III) supplies are depleted. By considering a one-dimensional reaction front in a constant unidirectional flow field, it is possible to derive a simple expression for the growth rate of a benzene plume. The method balances the mass flux of benzene with the Fe(III) content of the aquifer, assuming that the biodegradation reaction is instantaneous. The resulting expression shows that the benzene front migration is retarded relative to the ground water velocity by a factor that depends on the concentrations of hydrocarbon and bioavailable Fe(III). The method provides good agreement with benzene plumes at a crude oil study site in Minnesota and a gasoline site in South Carolina. Compared to the South Carolina site, the Minnesota site has 25% higher benzene flux but eight times the Fe(III), leading to about one-sixth the expansion rate. Although it was developed for benzene, toluene, ethylbenzene, and xylenes, the growth-rate estimation method may have applications to contaminant plumes from other persistent contaminant sources. Copyright ?? 2005 National Ground Water Association.

  13. Methods of Calculation of Resistance to Polarization (Corrosion Rate) Using ASTM G 59

    SciTech Connect

    Wong, L L; King, K J; Martin, S I; Rebak, R B

    2006-02-05

    The corrosion rate of a metal (alloy) can be measured using: (1) Immersion tests or weight loss such as in ASTM G 1 and G 31 or (2) Electrochemical techniques such as in ASTM G 59. In the polarization resistance (PR) or linear polarization method (G 59), the resistance to polarization (Rp) of a metal is measured in the electrolyte of interest in the vicinity of the corrosion potential (E{sub corr}). This polarization resistance can be mathematically converted into corrosion rates (CR). A plot of E vs. I in the vicinity of E{sub corr} is generated by increasing the potential at a fixed rate of 0.1667 mV/s and measuring the output current. The polarization resistance (Rp) is defined as the slope of a potential (E) (Y axis) vs. Current (I) (X axis) plot in the vicinity of the corrosion potential (E{sub corr}). When the potential is ramped and the current is measured, E is the independent variable and I is the dependent variable. In a proper mathematical plot, E should be represented in the X axis and I in the Y axis. However, in the conventions of the corrosion community, E is always plotted in the Y axis and I in the X axis. Therefore, how this plot of Delta E/Delta I is analyzed is a matter of current debate.

  14. Calculation of Zonal Winds using Accelerometer and Rate Data from Mars Global Surveyor

    NASA Technical Reports Server (NTRS)

    Baird, Darren T.; Tolson, Robert; Bougher, Stephen; Steers, Brian

    2006-01-01

    The Mars Global Surveyor spacecraft was initially placed into a high eccentricity, nearly polar orbit about Mars with a 45-hour period. To accomplish the science objectives of the mission, a 2-hour, circular orbit was required. Using a method known as aerobraking, numerous passes through the upper atmosphere slowed the spacecraft, thereby reducing the orbital period and eccentricity. To successfully perform aerobraking, the spacecraft was designed to be longitudinally, aerodynamically stable in pitch and yaw. Since the orbit is nearly polar, the yaw orientation of the spacecraft was sensitive to disturbances caused by the zonal components of wind (east-to-west or west-to-east) acting on the spacecraft at aerobraking altitudes. Zonal wind velocities were computed by equating the aerodynamic and inertia-related torques acting on the spacecraft. Comparisons of calculated zonal winds with those computed from the Mars Thermospheric Global Circulation Model are discussed.

  15. 50 CFR Table 3 to Part 679 - Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut 3 Table 3 to Part 679 Wildlife and Fisheries FISHERY...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 3 Table 3 to Part 679—Product...

  16. 50 CFR Table 3 to Part 679 - Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Product Recovery Rates for Groundfish Species and Conversion Rates for Pacific Halibut 3 Table 3 to Part 679 Wildlife and Fisheries FISHERY...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 3 Table 3 to Part 679—Product...

  17. Rates of dissolved organic carbon (DOC) production and bacterial activity in the eastern North Atlantic Subtropical Gyre during summer

    NASA Astrophysics Data System (ADS)

    Teira, E.; Pazó, M. J.; Quevedo, M.; Fuentes, M. V.; Niell, F. X.; Fernández, E.

    2003-04-01

    Rates of particulate organic carbon production, dissolved organic carbon production (DOC) and bacterial production were measured at 8 stations located in the eastern North Atlantic Subtropical Gyre during August 1998. Euphotic-depth-integrated particulate organic carbon (POC) production rate was on average 27 mg C m-2 h-1. The corresponding averaged integrated DOC production rate was 5 mg C m-2 h-1, i.e., about 20 % of total primary production. No statistically significant relationship was found between the rates of DOC and POC production, suggesting that other processes besides phytoplankton exudation, such as cell lysis or protist grazing, could substantially contribute to the release of DOC. Euphotic-depth-integrated bacterial biomass and production were, on average, 214 mg C m-2 and 1.4 mg C m-2 h-1, respectively. The lack of correlation between the rates of DOC release and bacterial activity, and a bacterial carbon demand (BCD, calculated by using an estimated bacterial growth efficiency ranging from 11 to 18%) in excess of DOC production suggest the existence of additional organic carbon sources (both allochthonous and/or autochthonous reservoirs), apart from in situ phytoplankton-derived DOC production, for the maintenance of bacterial activity in this region during summer.

  18. STEADY STATE FLAMMABLE GAS RELEASE RATE CALCULATION & LOWER FLAMMABILITY LEVEL EVALUATION FOR HANFORD TANK WASTE [SEC 1 & 2

    SciTech Connect

    HU, T.A.

    2003-09-30

    Flammable gases such as hydrogen, ammonia, and methane are observed in the tank dome space of the Hanford Site high-level waste tanks. This report assesses the steady-state flammability level under normal and off-normal ventilation conditions in the tank dome space for 177 double-shell tanks and single-shell tanks at the Hanford Site. The steady-state flammability level was estimated from the gas concentration of the mixture in the dome space using estimated gas release rates, Le Chatelier's rule and lower flammability limits of fuels in an air mixture. A time-dependent equation of gas concentration, which is a function of the gas release and ventilation rates in the dome space, has been developed for both soluble and insoluble gases. With this dynamic model, the time required to reach the specified flammability level at a given ventilation condition can be calculated. In the evaluation, hydrogen generation rates can be calculated for a given tank waste composition and its physical condition (e.g., waste density, waste volume, temperature, etc.) using the empirical rate equation model provided in Empirical Rate Equation Model and Rate Calculations of Hydrogen Generation for Hanford Tank Waste, HNF-3851. The release rate of other insoluble gases and the mass transport properties of the soluble gas can be derived from the observed steady-state gas concentration under normal ventilation conditions. The off-normal ventilation rate is assumed to be natural barometric breathing only. A large body of data is required to do both the hydrogen generation rate calculation and the flammability level evaluation. For tank waste that does not have sample-based data, a statistical-based value from probability distribution regression was used based on data from tanks belonging to a similar waste group. This report (Revision 3) updates the input data of hydrogen generation rates calculation for 177 tanks using the waste composition information in the Best-Basis Inventory Detail

  19. Radioactivity measurements and dose rate calculations using ERICA tool in the terrestrial environment of Greece.

    PubMed

    Sotiropoulou, Maria; Florou, Heleny; Manolopoulou, Metaxia

    2016-06-01

    In the present study, the radioactivity levels to which terrestrial non-human biota were exposed are examined. Organisms (grass and herbivore mammals) and abiotic components (soil) were collected during the period of 2010 to 2014 from grasslands where sheep and goats were free-range grazing. Natural background radionuclides ((226)Ra, (228)Ra, (228)Th) and artificial radionuclides ((137)Cs, (134)Cs, (131)I) were detected in the collected samples using gamma spectrometry. The actual measured activity concentrations and site-specific data of the studied organisms were imported in ERICA Assessment Tool (version 1.2.0) in order to provide an insight of the radiological dose rates. The highest activity concentrations were detected in samples collected from Lesvos island and the lowest in samples collected from Attiki and Etoloakarnania prefectures. The highest contribution to the total dose rate was clearly derived from the internal exposure and is closely related to the exposure to alpha emitters of natural background ((226)Ra and (228)Th). The Fukushima-derived traces of (137)Cs, (134)Cs, and (131)I, along with the residual (137)Cs, resulted in quite low contribution to the total dose rate. The obtained results may strengthen the adaptation of software tools to a wider range of ecosystems and may be proved useful in further research regarding the possible impact of protracted low level ionizing radiation on non-human biota. This kind of studies may contribute to the effective incorporation of dosimetry tools in the development of integrated environmental and radiological impact assessment policies.

  20. Radioactivity measurements and dose rate calculations using ERICA tool in the terrestrial environment of Greece.

    PubMed

    Sotiropoulou, Maria; Florou, Heleny; Manolopoulou, Metaxia

    2016-06-01

    In the present study, the radioactivity levels to which terrestrial non-human biota were exposed are examined. Organisms (grass and herbivore mammals) and abiotic components (soil) were collected during the period of 2010 to 2014 from grasslands where sheep and goats were free-range grazing. Natural background radionuclides ((226)Ra, (228)Ra, (228)Th) and artificial radionuclides ((137)Cs, (134)Cs, (131)I) were detected in the collected samples using gamma spectrometry. The actual measured activity concentrations and site-specific data of the studied organisms were imported in ERICA Assessment Tool (version 1.2.0) in order to provide an insight of the radiological dose rates. The highest activity concentrations were detected in samples collected from Lesvos island and the lowest in samples collected from Attiki and Etoloakarnania prefectures. The highest contribution to the total dose rate was clearly derived from the internal exposure and is closely related to the exposure to alpha emitters of natural background ((226)Ra and (228)Th). The Fukushima-derived traces of (137)Cs, (134)Cs, and (131)I, along with the residual (137)Cs, resulted in quite low contribution to the total dose rate. The obtained results may strengthen the adaptation of software tools to a wider range of ecosystems and may be proved useful in further research regarding the possible impact of protracted low level ionizing radiation on non-human biota. This kind of studies may contribute to the effective incorporation of dosimetry tools in the development of integrated environmental and radiological impact assessment policies. PMID:26897581

  1. Development of DUST: A computer code that calculates release rates from a LLW disposal unit

    SciTech Connect

    Sullivan, T.M.

    1992-01-01

    Performance assessment of a Low-Level Waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the disposal unit source term). The major physical processes that influence the source term are water flow, container degradation, waste form leaching, and radionuclide transport. A computer code, DUST (Disposal Unit Source Term) has been developed which incorporates these processes in a unified manner. The DUST code improves upon existing codes as it has the capability to model multiple container failure times, multiple waste form release properties, and radionuclide specific transport properties. Verification studies performed on the code are discussed.

  2. Development of DUST: A computer code that calculates release rates from a LLW disposal unit

    SciTech Connect

    Sullivan, T.M.

    1992-04-01

    Performance assessment of a Low-Level Waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the disposal unit source term). The major physical processes that influence the source term are water flow, container degradation, waste form leaching, and radionuclide transport. A computer code, DUST (Disposal Unit Source Term) has been developed which incorporates these processes in a unified manner. The DUST code improves upon existing codes as it has the capability to model multiple container failure times, multiple waste form release properties, and radionuclide specific transport properties. Verification studies performed on the code are discussed.

  3. Predicting Reduction Rates of Energetic Nitroaromatic Compounds Using Calculated One-Electron Reduction Potentials

    SciTech Connect

    Salter-Blanc, Alexandra; Bylaska, Eric J.; Johnston, Hayley; Tratnyek, Paul G.

    2015-02-11

    The evaluation of new energetic nitroaromatic compounds (NACs) for use in green munitions formulations requires models that can predict their environmental fate. The susceptibility of energetic NACs to nitro reduction might be predicted from correlations between rate constants (k) for this reaction and one-electron reduction potentials (E1NAC) / 0.059 V, but the mechanistic implications of such correlations are inconsistent with evidence from other methods. To address this inconsistency, we have reevaluated existing kinetic data using a (non-linear) free-energy relationship (FER) based on the Marcus theory of outer-sphere electron transfer. For most reductants, the results are inconsistent with rate limitation by an initial, outer-sphere electron transfer, suggesting that the strong correlation between k and E1NAC is justified only as an empirical model. This empirical correlation was used to calibrate a new quantitative structure-activity relationship (QSAR) using previously reported values of k for non-energetic NAC reduction by Fe(II) porphyrin and newly reported values of E1NAC determined using density functional theory at the B3LYP/6-311++G(2d,2p) level with the COSMO solvation model. The QSAR was then validated for energetic NACs using newly measured kinetic data for 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), and 2,4-dinitroanisole (DNAN). The data show close agreement with the QSAR, supporting its applicability to energetic NACs.

  4. Predicting Reduction Rates of Energetic Nitroaromatic Compounds Using Calculated One-Electron Reduction Potentials

    DOE PAGES

    Salter-Blanc, Alexandra; Bylaska, Eric J.; Johnston, Hayley; Tratnyek, Paul G.

    2015-02-11

    The evaluation of new energetic nitroaromatic compounds (NACs) for use in green munitions formulations requires models that can predict their environmental fate. The susceptibility of energetic NACs to nitro reduction might be predicted from correlations between rate constants (k) for this reaction and one-electron reduction potentials (E1NAC) / 0.059 V, but the mechanistic implications of such correlations are inconsistent with evidence from other methods. To address this inconsistency, we have reevaluated existing kinetic data using a (non-linear) free-energy relationship (FER) based on the Marcus theory of outer-sphere electron transfer. For most reductants, the results are inconsistent with rate limitation bymore » an initial, outer-sphere electron transfer, suggesting that the strong correlation between k and E1NAC is justified only as an empirical model. This empirical correlation was used to calibrate a new quantitative structure-activity relationship (QSAR) using previously reported values of k for non-energetic NAC reduction by Fe(II) porphyrin and newly reported values of E1NAC determined using density functional theory at the B3LYP/6-311++G(2d,2p) level with the COSMO solvation model. The QSAR was then validated for energetic NACs using newly measured kinetic data for 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), and 2,4-dinitroanisole (DNAN). The data show close agreement with the QSAR, supporting its applicability to energetic NACs.« less

  5. The trend of production rates with heliocentric distance for comet P/Halley

    NASA Technical Reports Server (NTRS)

    Fink, Uwe

    1994-01-01

    Comet P/Halley was observed spectroscopically in the wavelength range 5200-10,400 A during 10 observing runs, roughly a month apart from 1985 August 28 to 1986 June 6. The observations span a heliocentric distance from 0.73 to 2.52 AU. This data set is analyzed to determine the course of the production rate with heliocentric distance for C2, NH2, CN, and the continuum. The effect of changing the Haser scale lengths and their heliocentric distance dependence is examined. The production rate ratios to water change only in a minor way, but the absolute values of the production rates are more severely affected. Fluorescent efficiencies, or g-factors for the CN red system are calculated, and band intensity ratios for NH2 and CN are presented. Using presently available fluorescence efficiencies and Haser scale lengths, mixing ratios for the parents of C2, CN, and NH2 with respect to water are: 0.34 +/- 0.07%, 0.15 +/- 0.04%, and 0.13 +/- 0.05%. It is found that these mixing ratios are essentially constant over the heliocentric distance range of the observations, implying a rather uniform nucleus and uniform outgassing characteristics, although there are indications of smaller scale day-to-day variations. The results provide strong observational confirmation that water evaporation controls the activity of the comet over the distance range studied. Continuum values Af rho are determined, and their ratios to QH2O are found to have a clear dependence with heliocentric distance approximately r(exp -1.0) with a post-perihelion enhancement. No correlation of the production rate ratios with light curve of P/Halley were found, nor was there any correlation of the C2 or CN production with the dust.

  6. Direct calculation of average and marginal costs from the productive structure of an energy system

    SciTech Connect

    Lazzaretto, A.; Macor, A.

    1995-09-01

    Most of the thermoeconomic accounting and optimization methods for energy systems are based upon a definition of the productive purpose for each component. On the basis of this definition, a productive structure of the system can be defined in which the interactions among the components are described by their fuel product. The aim of this work is to calculate marginal and average unit costs of the exergy flows starting from their definitions by a direct inspection of the productive structure. As a main result, it is noticed that the only differences between marginal and average unit cost equations are located in the capital cost terms of input-output cost balance equations of the components. The method is illustrated using a cogenerative stream power plant and a combined gas-steam power plant.

  7. A rate equation approach to gain saturation effects in laser mode calculations

    NASA Technical Reports Server (NTRS)

    Roberts, Lila F.

    1990-01-01

    Space exploration and research require large amounts of power. Solar pumped laser systems have been shown to have the potential for meeting the performance requirements necessary for power transmission in space. The successful design of laser systems for these applications will depend, in part, on having a clear understanding of the development of the dynamical processes in the laser cavity and on the effects that changes in physical and design parameters have on laser performance. In particular, it is necessary to know the amplitude and phase distributions of the laser beam at the output aperture when steady state operation is achieved in order to determine the far-field power distribution. The output from the laser will depend on the active medium, the optical environment of the active material and on the gain distribution in the active region as laser action builds up and reaches steady state. An important component in the design process will be a realistic model of the active laser cavity. A computer model of the laser cavity, based on Huygens' principle was developed. The code calculates the amplitude and phase of an optical wave reflected back and forth between the mirrors of a laser cavity. The original code assumes a gain distribution which does not change with the buildup of oscillations in the cavity. A step in the direction of realism is the inclusion of a saturable gain medium in the cavity. The objective is to incorporate saturation effects into the existing computer model.

  8. Comparison between Measured and Calculated Sediment Transport Rates in North Fork Caspar Creek, California

    NASA Astrophysics Data System (ADS)

    Kim, T. W.; Yarnell, S. M.; Yager, E.; Leidman, S. Z.

    2015-12-01

    Caspar Creek is a gravel-bedded stream located in the Jackson Demonstration State Forest in the coast range of California. The Caspar Creek Experimental Watershed has been actively monitored and studied by the Pacific Southwest Research Station and California Department of Forestry and Fire Protection for over five decades. Although total annual sediment yield has been monitored through time, sediment transport during individual storm events is less certain. At a study site on North Fork Caspar Creek, cross-section averaged sediment flux was collected throughout two storm events in December 2014 and February 2015 to determine if two commonly used sediment transport equations—Meyer-Peter-Müller and Wilcock—approximated observed bedload transport. Cross-section averaged bedload samples were collected approximately every hour during each storm event using a Helley-Smith bedload sampler. Five-minute composite samples were collected at five equally spaced locations along a cross-section and then sieved to half-phi sizes to determine the grain size distribution. The measured sediment flux values varied widely throughout the storm hydrographs and were consistently less than two orders of magnitude in value in comparison to the calculated values. Armored bed conditions, changing hydraulic conditions during each storm and variable sediment supply may have contributed to the observed differences.

  9. Normalized impact factor (NIF): an adjusted method for calculating the citation rate of biomedical journals.

    PubMed

    Owlia, P; Vasei, M; Goliaei, B; Nassiri, I

    2011-04-01

    The interests in journal impact factor (JIF) in scientific communities have grown over the last decades. The JIFs are used to evaluate journals quality and the papers published therein. JIF is a discipline specific measure and the comparison between the JIF dedicated to different disciplines is inadequate, unless a normalization process is performed. In this study, normalized impact factor (NIF) was introduced as a relatively simple method enabling the JIFs to be used when evaluating the quality of journals and research works in different disciplines. The NIF index was established based on the multiplication of JIF by a constant factor. The constants were calculated for all 54 disciplines of biomedical field during 2005, 2006, 2007, 2008 and 2009 years. Also, ranking of 393 journals in different biomedical disciplines according to the NIF and JIF were compared to illustrate how the NIF index can be used for the evaluation of publications in different disciplines. The findings prove that the use of the NIF enhances the equality in assessing the quality of research works produced by researchers who work in different disciplines.

  10. Equations and calculations of product yields and preferred pathways for butanediol and mixed-acid fermentations

    SciTech Connect

    Papoutsakis, E.T.; Meyer, C.L.

    1985-01-01

    Using the available information of fermentation biochemistry, fermentation (stoichiometric) equations are derived for anaerobic saccharolytic fermentations of butanediol and mixed acids. The equations describe the interrelations among the fermentation products, biomass, and consumed substrate (glucose). The validity of the equations is tested using a variety of batch data from the literature. The validity of the equations is expected to extend to steady-state and transient fermentations, as well. Uses, improvements, and extensions of the equations are also discussed in detail. Among others, it is shown that the equations are useful for checking the consistency of experimental data, for calculating maximal yields and selectivities for the fermentation products, and calculating the extent of utilization of the Embden-Meyerhof-Parnas pathway versus the Hexose Monophosphate pathway of glucose utilization. 37 references.

  11. Perturbative QCD calculations of weak-boson production in association with jets at hadron colliders

    NASA Astrophysics Data System (ADS)

    Barger, V.; Han, T.; Ohnemus, J.; Zeppenfeld, D.

    1989-11-01

    We present perturbative QCD calculations of W,Z+n-jet production (n<=3) in pp¯ collisions at √s =0.63 and 1.8 TeV and also extrapolate the production cross sections to supercollider energies. The dependence of the cross sections on experimental cuts and the theoretical ambiguities are discussed in detail. It is shown that W/Z ratios of transverse-momentum distributions are quite insensitive to these uncertainties and can be predicted rather accurately. Neutrino counting and a top-quark search at large pT are addressed as applications. Our results are based on complete tree-level calculations of W,Z+(n+2)-parton amplitudes.

  12. Interpolation constants for calculation of transmittance and rate of dissociation of molecular oxygen in the mesosphere and lower thermosphere

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.; Mahle, S. H.

    1972-01-01

    Values of band oscillator strengths and rotational line widths for the Schumann-Runge band system have been used to derive interpolation constants from which the transmittance and rate of dissociation of molecular oxygen can be calculated. These constants, valid for temperatures between 150 and 300 K and for column densities between 1 x 10 to the 17th power/cm sq and 7 x 10 to the 24th power/cm sq, cover the wavelength range 1750 and 2050A.

  13. Time delays between core power production and external detector response from Monte Carlo calculations

    SciTech Connect

    Valentine, T.E.; Mihalczo, J.T.

    1996-08-01

    One primary concern for design of safety systems for reactors is the time response of external detectors to changes in the core. This paper describes a way to estimate the time delay between the core power production and the external detector response using Monte Carlo calculations and suggests a technique to measure the time delay. The Monte Carlo code KENO-NR was used to determine the time delay between the core power production and the external detector response for a conceptual design of the Advanced Neutron Source (ANS) reactor. The Monte Carlo estimated time delay was determined to be about 10 ms for this conceptual design of the ANS reactor.

  14. Automated calculations for massive fermion production with aı˚T ALC

    NASA Astrophysics Data System (ADS)

    Lorca, A.; Riemann, T.

    2004-10-01

    The package aı˚T ALC has been developed for the automated calculation of radiative corrections to two-fermion production at e+e- colliders. The package uses D IANA, Q GRAF, F ORM, F ORTRAN, FF, L OOPT OOLS, and further unix/linux tools. Numerical results are presented for e+e- → e+e-, μ+μ-, bs¯, tc¯.

  15. Reconciliation of Measured and TRANSP-calculated Neutron Emission Rates in the National Spherical Torus Experiment: Circa 2002-2005

    SciTech Connect

    S.S. Medley; D.S. Darrow; A.L. Roquemore

    2005-06-15

    A change in the response of the neutron detectors on the National Spherical Torus Experiment occurred between the 2002-2003 and 2004 experimental run periods. An analysis of this behavior by investigating the neutron diagnostic operating conditions and comparing measured and TRANSP-calculated neutron rates is presented. Also a revised procedure for cross calibration of the neutron scintillator detectors with the fission chamber detectors was implemented that delivers good agreement amongst the measured neutron rates for all neutron detectors and all run periods. For L-mode discharges, the measured and TRANSP-calculated neutron rates now match closely for all run years. For H-mode discharges over the entire 2002-2004 period, the 2FG scintillator and fission chamber measurements match each other but imply a neutron deficit of 11.5% relative to the TRANSP-calculated neutron. The results of this report impose a modification on all of the previously used calibration factors for the entire neutron detector suite over the 2002-2004 period. A tabular summary of the new calibration factors is provided including certified calibration factors for the 2005 run.

  16. Calculations on the Formation Rates and Mechanisms for CnH Anions in Interstellar and Circumstellar Media

    NASA Astrophysics Data System (ADS)

    Herbst, Eric; Osamura, Yoshihiro

    2008-06-01

    The rate coefficients for the radiative attachment reactions between the radicals CnH (n = 2-8) and electrons have been calculated with the aid of quantum chemistry using a phase-space theory in which strong coupling exists among the ground and any excited anion electronic states with the same spin. The results confirm that the process increases in efficiency with the size of the radical. For n >= 6, the rate coefficients lie at the collisional limit, in agreement with earlier estimates. For n = 4,5, the new results are larger than the old estimates. The calculated rate coefficient for C4H + e- is now much too large to explain the current observed abundance ratio of C4H-/C4H in IRC +10216 and L1527 and its upper limit in TMC-1. It is quite possible that electronic coupling is weak, and that so-called "dipole-bound" and other states must act as doorways to radiative attachment. We have also calculated potential surfaces for dissociative attachment starting with the "carbenes" H2C2m (m = 2-4) and leading to the syntheses of the anions C2mH-.

  17. Numerical calculation of protein-ligand binding rates through solution of the Smoluchowski equation using smooth particle hydrodynamics

    SciTech Connect

    Pan, Wenxiao; Daily, Michael D.; Baker, Nathan A.

    2015-12-01

    We demonstrate the accuracy and effectiveness of a Lagrangian particle-based method, smoothed particle hydrodynamics (SPH), to study diffusion in biomolecular systems by numerically solving the time-dependent Smoluchowski equation for continuum diffusion. The numerical method is first verified in simple systems and then applied to the calculation of ligand binding to an acetylcholinesterase monomer. Unlike previous studies, a reactive Robin boundary condition (BC), rather than the absolute absorbing (Dirichlet) boundary condition, is considered on the reactive boundaries. This new boundary condition treatment allows for the analysis of enzymes with "imperfect" reaction rates. Rates for inhibitor binding to mAChE are calculated at various ionic strengths and compared with experiment and other numerical methods. We find that imposition of the Robin BC improves agreement between calculated and experimental reaction rates. Although this initial application focuses on a single monomer system, our new method provides a framework to explore broader applications of SPH in larger-scale biomolecular complexes by taking advantage of its Lagrangian particle-based nature.

  18. The effect of photochemical models on calculated equilibria and cooling rates in the stratosphere

    NASA Technical Reports Server (NTRS)

    Blake, D.; Lindzen, R. S.

    1973-01-01

    Simplified models were developed for radiative heating and cooling and for ozone photochemistry in the region 22-60 km. The latter permit the inclusion of nitrogen and hydrogen reactions in addition to simple oxygen reactions. The simplicity of the scheme facilitates the use of a wide variety of cooling and reaction rates. It is shown that joint radiative-photochemical equilibrium is appropriate to the mean state of the atmosphere between 35 and 60 km. The relaxation of perturbations from joint radiative-photochemical equilibrium was also investigated. In all cases the coupling between temperature dependent ozone photochemistry and radiation lead to a reduction of the thermal relaxation time from its purely radiative value. The latter, which amounts to about 10 days, is reduced to 2-4 days at heights of 31-35 km. This greatly enhances the dissipation of waves traveling through the stratosphere.

  19. Implementation of a Thermodynamic Solver within a Computer Program for Calculating Fission-Product Release Fractions

    NASA Astrophysics Data System (ADS)

    Barber, Duncan Henry

    During some postulated accidents at nuclear power stations, fuel cooling may be impaired. In such cases, the fuel heats up and the subsequent increased fission-gas release from the fuel to the gap may result in fuel sheath failure. After fuel sheath failure, the barrier between the coolant and the fuel pellets is lost or impaired, gases and vapours from the fuel-to-sheath gap and other open voids in the fuel pellets can be vented. Gases and steam from the coolant can enter the broken fuel sheath and interact with the fuel pellet surfaces and the fission-product inclusion on the fuel surface (including material at the surface of the fuel matrix). The chemistry of this interaction is an important mechanism to model in order to assess fission-product releases from fuel. Starting in 1995, the computer program SOURCE 2.0 was developed by the Canadian nuclear industry to model fission-product release from fuel during such accidents. SOURCE 2.0 has employed an early thermochemical model of irradiated uranium dioxide fuel developed at the Royal Military College of Canada. To overcome the limitations of computers of that time, the implementation of the RMC model employed lookup tables to pre-calculated equilibrium conditions. In the intervening years, the RMC model has been improved, the power of computers has increased significantly, and thermodynamic subroutine libraries have become available. This thesis is the result of extensive work based on these three factors. A prototype computer program (referred to as SC11) has been developed that uses a thermodynamic subroutine library to calculate thermodynamic equilibria using Gibbs energy minimization. The Gibbs energy minimization requires the system temperature (T) and pressure (P), and the inventory of chemical elements (n) in the system. In order to calculate the inventory of chemical elements in the fuel, the list of nuclides and nuclear isomers modelled in SC11 had to be expanded from the list used by SOURCE 2.0. A

  20. Effect of growth rate on plasmid DNA production and metabolic performance of engineered Escherichia coli strains.

    PubMed

    Wunderlich, Martin; Taymaz-Nikerel, Hilal; Gosset, Guillermo; Ramírez, Octavio T; Lara, Alvaro R

    2014-03-01

    Two engineered Escherichia coli strains, designated VH33 and VH34, were compared to their parent strain W3110 in chemostat mode during plasmid DNA (pDNA) production. In strain VH33 the glucose uptake system was modified with the aim of reducing overflow metabolism. The strain VH34 has an additional deletion of the pyruvate kinase A gene (pykA) to increase pDNA formation. pDNA formation rates as well as kinetic and stoichiometric parameters were investigated in dependence of the growth rate within a range from 0.02 to 0.25 h(-1). Differences between strains were found in terms of the biomass yields on nitrogen and oxygen, as well as on the cell maintenance coefficients. The deletion of pykA led to a significantly increased pDNA yield and productivity. At an optimal growth rate of 0.20 h(-1) it was nearly 60% higher than that of W3110 and VH33. Metabolic fluxes calculated by metabolite balance analysis showed differences mainly in reactions catalyzed by pyruvate kinase and glucose 6-phosphate dehydrogenase. The obtained data are useful for the design of cultivation schemes for pDNA production by E. coli. PMID:24012107

  1. Measurement and Analysis of Extracellular Acid Production to Determine Glycolytic Rate.

    PubMed

    Mookerjee, Shona A; Brand, Martin D

    2015-12-12

    Extracellular measurement of oxygen consumption and acid production is a simple and powerful way to monitor rates of respiration and glycolysis(1). Both mitochondrial (respiration) and non-mitochondrial (other redox) reactions consume oxygen, but these reactions can be easily distinguished by chemical inhibition of mitochondrial respiration. However, while mitochondrial oxygen consumption is an unambiguous and direct measurement of respiration rate(2), the same is not true for extracellular acid production and its relationship to glycolytic rate (3-6). Extracellular acid produced by cells is derived from both lactate, produced by anaerobic glycolysis, and CO2, produced in the citric acid cycle during respiration. For glycolysis, the conversion of glucose to lactate(-) + H(+) and the export of products into the assay medium is the source of glycolytic acidification. For respiration, the export of CO2, hydration to H2CO3 and dissociation to HCO3(-) + H(+) is the source of respiratory acidification. The proportions of glycolytic and respiratory acidification depend on the experimental conditions, including cell type and substrate(s) provided, and can range from nearly 100% glycolytic acidification to nearly 100% respiratory acidification (6). Here, we demonstrate the data collection and calculation methods needed to determine respiratory and glycolytic contributions to total extracellular acidification by whole cells in culture using C2C12 myoblast cells as a model.

  2. Model calculations of tropospheric ozone production potential following observed convective events

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Thompson, Anne M.; Dickerson, Russell R.; Luke, Winston T.; Mcnamara, Donna P.

    1990-01-01

    The profiles of CO, NO, O3, water vapor, and temperature, observed in 1985 during and after a series of convective events over rural areas of the south-central United States, were used to model the nonurban ozone production rates and to evaluate the effects of convective clouds on the tropospheric trace-gas chemistry. A comparison of trace-gas profiles measured in and around a large cumulonimbus during its dissipation showed that ozone production in the upper troposphere may be increased fourfold by convection relative to undisturbed air. The convective enhancement of O3 production for the entire tropospheric comlumn was found to be about 50 percent.

  3. In-situ Measurements of Ozone Production Rates and Comparisons to Model-derived Production Rates During the Houston, TX and Denver, CO DISCOVER-AQ Campaigns

    NASA Astrophysics Data System (ADS)

    Baier, B. C.; Brune, W. H.; Miller, D. O.; Lefer, B. L.

    2015-12-01

    Tropospheric ozone (O3) is a secondary pollutant that has harmful effects on human and plant life. The climate and urban emissions in Houston, TX and Denver, CO can be conducive for significant ozone production and thus, high ozone events. Tighter government strategies for ozone mitigation have been proposed, which involve reducing the current EPA eight-hour ozone standard from 75 ppb to 65-70 ppb. These strategies rely on the reduction of ozone precursors in order to decrease the ozone production rate, P(O3). The changes in the ozone concentration at a certain location are dependent upon P(O3), so decreasing P(O3) can decrease ozone levels provided that it has not been transported from other areas. Air quality models test reduction strategies before they are implemented, locate ozone sources, and predict ozone episodes. Traditionally, P(O3) has been calculated by models. However, large uncertainties in model emissions inventories, chemical mechanisms, and meteorology can reduce confidence in this approach. A new instrument, the Measurement of Ozone Production Sensor (MOPS) directly measures P(O3) and can provide an alternate approach to determining P(O3). An updated version of the Penn State MOPS (MOPSv2.0) was deployed to Houston, TX and Denver, CO as a part of NASA's DISCOVER-AQ field campaign in the summers of 2013 and 2014, respectively. We present MOPS directly-measured P(O3) rates from these areas, as well as comparisons to zero-dimensional and three-dimensional modeled P(O3) using the RACM2 and MCMv2.2 mechanisms. These comparisons demonstrate the potential of the MOPS to test and evaluate model-derived P(O3), to advance the understanding of model chemical mechanisms, and to improve predictions of high ozone events.

  4. Time-dependent density-functional-theory calculation of strong-field ionization rates of H2

    NASA Astrophysics Data System (ADS)

    Chu, Xi

    2010-08-01

    We report a numerical study of strong-field ionization rates of the H2 molecule using time-dependent density-functional theory (TDDFT). In the dc field limit, TDDFT results for the rate of tunneling ionization agree with molecular Ammosov-Delone-Kralnov (MO-ADK) predictions, as well as results from a complex scaling method at the full configuration interaction level. Our study demonstrates the effect of photon energy, molecular vibration, and orientation on the ionization. Calculated rates for 800-nm lasers are about four times greater than the values predicted by the slowly varying field approximation for tunneling ionization. The rate for the ground vibrational state is higher than that of the fixed nuclei value at the equilibrium distance. This difference decreases with increasing field intensity. When the field intensity is sufficiently high, the two rates are very similar, and the fixed nuclear distance rate may be used to approximate the ground-vibrational-state rate. TDDFT methods predict an anisotropy slightly larger than the prediction obtained from the MO-ADK method. We also find that the field intensity plays a role in the anisotropy, which the MO-ADK results do not show.

  5. Calculations of Solar Shortwave Heating Rates due to Black Carbon and Ozone Absorption Using in Situ Measurements

    NASA Technical Reports Server (NTRS)

    Gao, R. S.; Hall, S. R.; Swartz, W. H.; Spackman, J. R.; Watts, L. A.; Fahey, D. W.; Aikin, K. C.; Shetter, R. E.; Bui, T. P.

    2008-01-01

    Results for the solar heating rates in ambient air due to absorption by black-carbon (BC) containing particles and ozone are presented as calculated from airborne observations made in the tropical tropopause layer (TTL) in January-February 2006. The method uses airborne in situ observations of BC particles, ozone and actinic flux. Total BC mass is obtained along the flight track by summing the masses of individually detected BC particles in the range 90 to 600-nm volume-equivalent diameter, which includes most of the BC mass. Ozone mixing ratios and upwelling and partial downwelling solar actinic fluxes were measured concurrently with BC mass. Two estimates used for the BC wavelength-dependent absorption cross section yielded similar heating rates. For mean altitudes of 16.5, 17.5, and 18.5 km (0.5 km) in the tropics, average BC heating rates were near 0.0002 K/d. Observed BC coatings on individual particles approximately double derived BC heating rates. Ozone heating rates exceeded BC heating rates by approximately a factor of 100 on average and at least a factor of 4, suggesting that BC heating rates in this region are negligible in comparison.

  6. Controls on urban ozone production rate as indicated by formaldehyde oxidation rate and nitric oxide

    NASA Astrophysics Data System (ADS)

    Chatfield, Robert B.; Ren, Xinrong; Brune, William; Schwab, James; PMTACS Measurement Teams

    2010-12-01

    Several strong statistical relationships quantifying local ozone generation are found which use only easily measured variables: nitrogen oxides (NO x), formaldehyde (HCHO), its photolysis (i.e., UV), and temperature ( T). A parameterized regression developed for rural air was adapted to central Queens, New York City, i.e., considerable fresh emissions. Measurements of the radicals [HO 2] and [OH] were available. These provided explicit reference estimates of the predominant terms for chemical ozone production, Po(O 3) = k[HO 2][NO], of the predominant chemical loss of nitrogen oxides, L(NO 2) = k[OH][NO 2], and also their ratio. (This is termed a production efficiency for O 3.) Chemical modeling supports a robust extension from Po(O 3) to total chemical production, P(O 3). The two regression variables, [NO] and jHCHO⇒rads × [HCHO], which best explain Po(O 3), have low correlation, R ˜ 0.2 (variable, interacting urban plumelets?). In our analysis, R2 for Po(O 3) (and an estimate for its rate-determining [HO 2]) was in the range 0.48-0.81. Signally, the method suggests a quantitative and very local application of descriptions of "VOC limitation" or "NO x limitation" to P(O 3) and L(NO 2), expressed as dimensionless sensitivity variables. Unexpected sources, transport, or chemistry may be highlighted using only HCHO, NO x, and UV radiation. More complex relationships are needed in a focused analysis of intermediate polluted situations, where timescales or individual sources may give trouble. Here, we find that T is informative, and cooperates with j × [HCHO] in defining [HO 2]. Sensitivities for radicals and NO for Po(O 3) are similar ˜0.4, but sensitivities for radicals and NO 2 for L(NO 2) emphasize NO 2. Remaining variability in the statistical estimates of Po(O 3) and L(NO 2) is modulated by incompletely understood, slowly varying gain factors. Understanding of these gain factors promises a better empirical indicator for Po(O 3)/ L(NO 2). Complete 3-d

  7. Intrinsic autotrophic biomass yield and productivity in algae: modeling spectral and mixing-rate dependence.

    PubMed

    Holland, Alexandra D; Wheeler, Dean R

    2011-05-01

    For non-inhibitory irradiances, the rate of algal biomass synthesis was modeled as the product of the algal autotrophic yield Φ(DW) and the flux of photons absorbed by the culture, as described using Beer-Lambert law. As a contrast to earlier attempts, the use of scatter-corrected extinction coefficients enabled the validation of such approach, which bypasses determination of photosynthesis-irradiance (PI) kinetic parameters. The broad misconception that PI curves, or the equivalent use of specific growth rate expressions independent of the biomass concentration, can be extended to adequately model biomass production under light-limitation is addressed. For inhibitory irradiances, a proposed mechanistic model, based on the photosynthetic units (PSU) concept, allows one to estimate a target speed νT across the photic zone in order to limit the flux of photons per cell to levels averting significant reductions in Φ(DW) . These modeled target speeds, on the order of 5-20 m s(-1) for high outdoor irradiances, call for fundamental changes in reactor design to optimize biomass productivity. The presented analysis enables a straightforward bioreactor parameterization, which, in-turn, guides the establishment of conditions ensuring maximum productivity and complete nutrients consumption. Additionally, solar and fluorescent lighting spectra were used to calculate energy to photon-counts conversion factors. PMID:21381201

  8. Intrinsic autotrophic biomass yield and productivity in algae: modeling spectral and mixing-rate dependence.

    PubMed

    Holland, Alexandra D; Wheeler, Dean R

    2011-05-01

    For non-inhibitory irradiances, the rate of algal biomass synthesis was modeled as the product of the algal autotrophic yield Φ(DW) and the flux of photons absorbed by the culture, as described using Beer-Lambert law. As a contrast to earlier attempts, the use of scatter-corrected extinction coefficients enabled the validation of such approach, which bypasses determination of photosynthesis-irradiance (PI) kinetic parameters. The broad misconception that PI curves, or the equivalent use of specific growth rate expressions independent of the biomass concentration, can be extended to adequately model biomass production under light-limitation is addressed. For inhibitory irradiances, a proposed mechanistic model, based on the photosynthetic units (PSU) concept, allows one to estimate a target speed νT across the photic zone in order to limit the flux of photons per cell to levels averting significant reductions in Φ(DW) . These modeled target speeds, on the order of 5-20 m s(-1) for high outdoor irradiances, call for fundamental changes in reactor design to optimize biomass productivity. The presented analysis enables a straightforward bioreactor parameterization, which, in-turn, guides the establishment of conditions ensuring maximum productivity and complete nutrients consumption. Additionally, solar and fluorescent lighting spectra were used to calculate energy to photon-counts conversion factors.

  9. Calculation of relative glomerular filtration rate and correlation with delayed technetium-99m DMSA imaging

    SciTech Connect

    Taylor, A. Jr.; Kipper, M.; Witztum, K.

    1986-01-01

    The relative renal uptake of Tc-99m DMSA was compared with the relative glomerular filtration rate (GFR) in ten patients with serum creatinines ranging from 0.3 to 2.5 mg/dl. Relative GFR was based on the renal uptake of Tc-99m DTPA determined by two methods: 1) integrating the counts from 1 to 3 minutes postinjection and correcting for background. 2) Totalizing the individual renal counts in a single 15-second frame from 2:45 minutes to 3:00 minutes postinjection and correcting for background. The two methods of determining relative DTPA uptake showed excellent correlation, r = 0.98. Relative DMSA uptake determined at 24 hours post-injection using computer-assisted regions of interest showed excellent correlation with the relative GFR determined by either the integral or single-frame method, r = 0.98. The addition of background subtraction for the DMSA images at 24 hours did not improve the correlation.

  10. Production rates of 36Cl in basalts from the calibration site of Fuerteventura, Canary Islands

    NASA Astrophysics Data System (ADS)

    Mai, K.

    2009-09-01

    the individual production mechanisms given in the literature make the estimation of expected total production rates rather difficult. Production rates for individual production mechanisms of 36Cl could not be obtained due to the lack of suitable phenocrysts. The production rates for the total rock are somewhat higher, except for erosion affected flows, but still compare fairly well with data presented elsewhere in the literature. For the samples of 36Cl concentrations higher than expected a number of possible reasons is evaluated which in combination may cause increased 36Cl build-up, such as thin water layers trapped in the uppermost vesicles in the rock, or a weaker earth magnetic field or problems with the Ar ages. The calculation of the production rate of 36Cl from Ca and of the thermal neutron flux had to be based on literature data for the other production paths involved in the total production. These data indicate loss of 36Cl in some of the samples while other samples even show increased 36Cl contents compared to the expected amounts.

  11. Calculating clear-sky radiative heating rates using the Fu-Liou RTM with inputs from observed and reanalyzed profiles

    NASA Astrophysics Data System (ADS)

    Dolinar, E. K.; Dong, X.; Xi, B.

    2015-12-01

    One-dimensional radiative transfer models (RTM) are a common tool used for calculating atmospheric heating rates and radiative fluxes. In the forward sense, RTMs use known (or observed) quantities of the atmospheric state and surface characteristics to determine the appropriate surface and top-of-atmosphere (TOA) radiative fluxes. The NASA CERES science team uses the modified Fu-Liou RTM to calculate atmospheric heating rates and surface and TOA fluxes using the CERES observed TOA shortwave (SW) and longwave (LW) fluxes as constraints to derive global surface and TOA radiation budgets using a reanalyzed atmospheric state (e.g. temperature and various greenhouse gases) from the newly developed MERRA-2. However, closure studies have shown that using the reanalyzed state as input to the RTM introduces some disparity between the RTM calculated fluxes and surface observed ones. The purpose of this study is to generate a database of observed atmospheric state profiles, from satellite and ground-based sources, at several permanent Atmospheric Radiation Measurement (ARM) Program sites, including the Southern Great Plains (SGP), Northern Slope of Alaska (NSA) and Tropical Western Pacific Nauru (TWP-C2), and Eastern North Atlantic (ENA) permanent facilities. Since clouds are a major modulator of radiative transfer within the Earth's atmosphere, we will focus on the clear-sky conditions in this study, which will set up the baseline for our cloudy studies in the future. Clear-sky flux profiles are calculated using the Edition 4 NASA LaRC modified Fu-Liou RTM. The aforementioned atmospheric profiles generated in-house are used as input into the RTM, as well as from reanalyses. The calculated surface and TOA fluxes are compared with ARM surface measured and CERES satellite observed SW and LW fluxes, respectively. Clear-sky cases are identified by the ARM radar-lidar observations, as well as satellite observations, at the select ARM sites.

  12. Improving the accuracy of the calculation of fusion rates and sticking fractions in muon-catalyzed fusion

    SciTech Connect

    Morgan, J.D. III )

    1989-12-15

    Two critical quantities in muon-catalyzed {ital d}-{ital t} fusion are the {ital d}-{ital t} fusion rate {l angle}{psi}{vert bar}{delta}{sup (3)}({bold r}{sub dt}){vert bar}{psi}{r angle} and the {alpha}-{mu} sticking fraction {vert bar}{l angle}{var phi}({bold r})e{sup i}{bold q}{center dot}{bold r}{vert bar}{delta}{sup (3)}({bold r} {sub {ital d}{ital t}}){vert bar}{psi}({bold r}{sub {ital t}},{bold r}){r angle}{vert bar}{sup 2}/{l angle}{psi}{vert bar}{delta}{sup (3)}({bold r}{sub {ital dt}}){vert bar}{psi}{r angle}, where {psi} is a ({ital dt}{mu}){sup +} wave function and {var phi} is a hydrogenic {alpha}-{mu} wave function. It is explained why conventional approaches to calculate these quantities directly are slowly convergent. It is suggested that the use of a basis that explicitly includes terms that appear in the Fock expansion will lead to more rapid convergence. Furthermore, an identity relating {l angle}{psi}{vert bar}{delta}{sup (3)}({bold r}){vert bar}{psi}{r angle} to expectation values of more diffuse operators, which was first derived by Hiller, Sucher, and Feinberg (Phys. Rev. A 18, 2399 (1978)) and then extended by Drake (Nucl. Instrum. Methods Phys. Res. B 31, 7 (1988)) in the context of atomic calculations, is generalized to the calculation of fusion rates and sticking fractions. It is anticipated that these relations will facilitate the accurate calculation of fusion rates and of sticking fractions.

  13. Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.

    PubMed

    Abbady, Adel G E; El-Arabi, A M; Abbady, A

    2006-01-01

    Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites. PMID:16120480

  14. Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.

    PubMed

    Abbady, Adel G E; El-Arabi, A M; Abbady, A

    2006-01-01

    Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites.

  15. Calculation of Passive Sampling Rates from Both Native PCBs and Depuration Compounds in Indoor and Outdoor Environments

    PubMed Central

    Persoon, Carolyn; Hornbuckle, Keri C.

    2009-01-01

    Passive sampling has become a practical way of sampling persistent organic pollutants over large spatial and remote areas; however, its ease in use is also coupled with some uncertainty in calculating air concentrations from accumulated mass. Here we report a comparison study of polyurethane-foam-based passive samplers (PUF-PAS) for quantitatively determining the sampling rates of polychlorinated biphenyls (PCBs) from air. We measured both uptake of native PCBs and loss of depuration compounds and determined the sampling rates (R-values) for multiple samplers harvested at three different time periods. The uptake of native PCBs in the linear phase was similar to the loss of depuration compounds for indoor air and behaved as predicted. A single R- value of 2.6 m3d−1 was calculated from the mean of 12 samplers deployed indoors from three harvest dates with a range of 2.0 to 3.4 m3d−1 for both uptake of native PCBs and loss of depuration compounds. Loss of depuration compounds in outdoor air also followed the predicted linear behavior with a range of calculated R-value of 4.4 – 8.4 m3d−1. Uptake of native PCBs behavior was extremely variable, probably due to changes in ambient air concentrations and resulted in R-values of 1.6–11.5 m3d−1 with greater variation seen in higher chlorinated homolog groups. PMID:19068264

  16. Development and field deployment of an instrument to measure ozone production rates in the troposphere

    NASA Astrophysics Data System (ADS)

    Sklaveniti, S.; Locoge, N.; Dusanter, S.; Leonardis, T.; Lew, M.; Bottorff, B.; Sigler, P. S. R.; Stevens, P. S.; Wood, E. C. D.; Kundu, S.; Gentner, D. R.

    2015-12-01

    Ozone is a greenhouse gas and a primary constituent of urban smog, irritating the respiratory system and damaging the vegetation. The current understanding of ozone chemistry in the troposphere indicates that net ozone production P(O3) occurs when peroxy radicals (HO2+RO2) react with NO producing NO2, whose photolysis leads to O3 formation. P(O3) values can be calculated from peroxy radical concentrations, either from ambient measurements or box model outputs. These two estimation methods often disagree for NOx mixing ratios higher than a few ppb, questioning our ability to measure peroxy radicals under high NOx conditions or indicating that there are still unknowns in our understanding of the radical and ozone production chemistry. Direct measurements of ozone production rates will help to address this issue and improve air quality regulations. We will present the development of an instrument for direct measurements of ozone production rates (OPR). The OPR instrument consists of three parts: (i) two quartz flow tubes sampling ambient air ("Ambient" and "Reference" flow tube), (ii) an O3-to-NO2 conversion unit, and (iii) a Cavity Attenuated Phase Shift (CAPS) monitor to measure NO2. The air in the Ambient flow tube undergoes the same photochemistry as in ambient air, while the Reference flow tube is covered by a UV filter limiting the formation of ozone. Exiting the flow tubes, ozone is converted into NO2 and the sum O3+NO2 (Ox) is measured by the CAPS monitor. The difference in Ox between the two flow tubes divided by the residence time yields the Ox production rate, P(Ox). P(O3) is assumed to be equal to P(Ox) when NO2 is efficiently photolyzed during daytime. We will present preliminary results from the Indiana Radical, Reactivity and Ozone Production Intercomparison (IRRONIC) campaign in Bloomington, Indiana, during July 2015, where ozone production rates were measured by introducing various amounts of NO inside the flow tubes to investigate the ozone

  17. 76 FR 2930 - International Product Change-Global Expedited Package Services-Non- Published Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... Product Change--Global Expedited Package Services-- Non- Published Rates AGENCY: Postal Service\\TM... Commission to add Global Expedited Package Services-- Non-Published Rates 2 to the Competitive Products List... Service to add Global Expedited Package Services--Non-Published Rates, to the Competitive Products...

  18. 30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... my well or reservoir production rates? (a) The Regional Supervisor may set a Maximum Production Rate... 30 Mineral Resources 2 2013-07-01 2013-07-01 false May the Regional Supervisor limit my well or reservoir production rates? 250.1159 Section 250.1159 Mineral Resources BUREAU OF SAFETY AND...

  19. 30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... my well or reservoir production rates? (a) The Regional Supervisor may set a Maximum Production Rate... 30 Mineral Resources 2 2014-07-01 2014-07-01 false May the Regional Supervisor limit my well or reservoir production rates? 250.1159 Section 250.1159 Mineral Resources BUREAU OF SAFETY AND...

  20. 30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... my well or reservoir production rates? (a) The Regional Supervisor may set a Maximum Production Rate... 30 Mineral Resources 2 2012-07-01 2012-07-01 false May the Regional Supervisor limit my well or reservoir production rates? 250.1159 Section 250.1159 Mineral Resources BUREAU OF SAFETY AND...

  1. Determination of optimal lot size and production rate for multi-production channels with limited capacity

    NASA Astrophysics Data System (ADS)

    Huang, Yeu-Shiang; Wang, Ruei-Pei; Ho, Jyh-Wen

    2015-07-01

    Due to the constantly changing business environment, producers often have to deal with customers by adopting different procurement policies. That is, manufacturers confront not only predictable and regular orders, but also unpredictable and irregular orders. In this study, from the perspective of upstream manufacturers, both regular and irregular orders are considered in coping with the situation in which an uncertain demand is faced by the manufacturer, and a capacity confirming mechanism is used to examine such demand. If the demand is less than or equal to the capacity of the ordinary production channel, the general supply channel is utilised to fully account for the manufacturing process, but if the demand is greater than the capacity of the ordinary production channel, the contingency production channel would be activated along with the ordinary channel to satisfy the upcoming high demand. Besides, the reproductive property of the probability distribution is employed to represent the order quantity of the two types of demand. Accordingly, the optimal production rates and lot sizes for both channels are derived to provide managers with insights for further production planning.

  2. Comparison between Theoretical Calculation and Experimental Results of Excitation Functions for Production of Relevant Biomedical Radionuclides

    SciTech Connect

    Menapace, E.; Birattari, C.; Bonardi, M.L.; Groppi, F.; Morzenti, S.; Zona, C.

    2005-05-24

    The radionuclide production for biomedical applications has been brought up in the years, as a special nuclear application, at INFN LASA Laboratory, particularly in co-operation with the JRC-Ispra of EC. Mainly scientific aspects concerning radiation detection and the relevant instruments, the measurements of excitation functions of the involved nuclear reactions, the requested radiochemistry studies and further applications have been investigated. On the side of the nuclear data evaluations, based on nuclear model calculations and critically selected experimental data, the appropriate competence has been developed at ENEA Division for Advanced Physics Technologies. A series of high specific activity accelerator-produced radionuclides in no-carrier-added (NCA) form, for uses in metabolic radiotherapy and for PET radiodiagnostics, are investigated. In this work, last revised measurements and model calculations are reviewed for excitation functions of natZn(d,X)64Cu, 66Ga reactions, referring to irradiation experiments at K=38 variable energy Cyclotron of JRC-Ispra. Concerning the reaction data for producing 186gRe and 211At/211gPo (including significant emission spectra) and 210At, most recent and critically selected experimental results are considered and discussed in comparison with model calculations paying special care to pre-equilibrium effects estimate and to the appropriate overall parameterization. Model calculations are presented for 226Ra(p,2n)225Ac reaction, according to the working program of the ongoing IAEA CRP on the matter.

  3. Plutonium-aerosol emission rates and human pulmonary deposition calculations for Nuclear Site 201, Nevada Test Site

    SciTech Connect

    Shinn, J.H.; Homan, D.N.

    1982-06-21

    This study determined the plutonium-aerosol fluxes from the soil to quantify (1) the extent of potential human exposure by deep-lung retention of alpha-emitting particles; (2) the source term should there be any significant, long-term, transport of plutonium aerosols; and (3) the resuspension factor and rate so that, for the first time at any nuclear site, one may calculate how long it will take for wind erosion to carry away a significant amount of the contaminated soil. High-volume air samplers and cascade impactors were used to characterize the plutonium aerosols. Meteorological flux-profile methods were used to calculate dust and plutonium aerosol emission rates. A floorless wind tunnel (10-m long) was used to examine resuspension under steady-state, high wind speed. The resuspension factor was two orders of magnitude lower than the other comparable sites at NTS and elsewhere, and the average resuspension rate of 5.3 x 10/sup -8//d was also very low, so that the half-time for resuspension by wind erosion was about 36,000 y.

  4. Influence of the superposition approximation on calculated effective dose rates from galactic cosmic rays at aerospace-related altitudes

    NASA Astrophysics Data System (ADS)

    Copeland, Kyle

    2015-07-01

    The superposition approximation was commonly employed in atmospheric nuclear transport modeling until recent years and is incorporated into flight dose calculation codes such as CARI-6 and EPCARD. The useful altitude range for this approximation is investigated using Monte Carlo transport techniques. CARI-7A simulates atmospheric radiation transport of elements H-Fe using a database of precalculated galactic cosmic radiation showers calculated with MCNPX 2.7.0 and is employed here to investigate the influence of the superposition approximation on effective dose rates, relative to full nuclear transport of galactic cosmic ray primary ions. Superposition is found to produce results less than 10% different from nuclear transport at current commercial and business aviation altitudes while underestimating dose rates at higher altitudes. The underestimate sometimes exceeds 20% at approximately 23 km and exceeds 40% at 50 km. Thus, programs employing this approximation should not be used to estimate doses or dose rates for high-altitude portions of the commercial space and near-space manned flights that are expected to begin soon.

  5. An empirically derived basis for calculating the area, rate, and distribution of water-drop impingement on airfoils

    NASA Technical Reports Server (NTRS)

    Bergrun, Norman R

    1952-01-01

    An empirically derived basis for predicting the area, rate, and distribution of water-drop impingement on airfoils of arbitrary section is presented. The concepts involved represent an initial step toward the development of a calculation technique which is generally applicable to the design of thermal ice-prevention equipment for airplane wing and tail surfaces. It is shown that sufficiently accurate estimates, for the purpose of heated-wing design, can be obtained by a few numerical computations once the velocity distribution over the airfoil has been determined. The calculation technique presented is based on results of extensive water-drop trajectory computations for five airfoil cases which consisted of 15-percent-thick airfoils encompassing a moderate lift-coefficient range. The differential equations pertaining to the paths of the drops were solved by a differential analyzer.

  6. 27 CFR 19.246 - Computing the effective tax rate for a product.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Computing the effective... Spirits Taxes Effective Tax Rates § 19.246 Computing the effective tax rate for a product. (a) How to compute effective tax rates. In order to determine the effective tax rate for a distilled spirits...

  7. INTERWELL CONNECTIVITY AND DIAGNOSIS USING CORRELATION OF PRODUCTION AND INJECTION RATE DATA IN HYDROCARBON PRODUCTION

    SciTech Connect

    Jerry L. Jensen; Larry W. Lake; Thang D. Bui; Ali Al-Yousef; Pablo Gentil

    2004-08-01

    This report details much of the progress on inferring interwell communication from well rate fluctuations. The goal of the project was to investigate the feasibility of inferring reservoir properties through weights derived from correlations between injection and production rates. We have focused on and accomplished the following items: (1) We have identified two possible causes for the source of negative weights. These are colinearity between injectors, and nonstationarity of be production data. (2) Colinearity has been addressed through ridge regression. Though there is much to be done here, such regression represents a trade-off between a minimum variance estimator and a biased estimator. (3) We have applied the ridge regression and the original Albertoni procedure to field data from the Magnus field. (4) The entire procedure (with several options) has been codified as a spreadsheet add-in. (5) Finally, we have begun, and report on, an extension of the method to predicting oil rates. Successful completion of these items will constitute the bulk of the final year's report.

  8. Application of Thermodynamic Calculations to the Pyro-refining Process for Production of High Purity Bismuth

    NASA Astrophysics Data System (ADS)

    Mezbahul-Islam, Mohammad; Belanger, Frederic; Chartrand, Patrice; Jung, In-Ho; Coursol, Pascal

    2016-04-01

    The present work has been performed with the aim to optimize the existing process for the production of high purity bismuth (99.999 pct). A thermo-chemical database including most of the probable impurities of bismuth (Bi-X, X = Ag, Au, Al, Ca, Cu, Fe, Mg, Mn, Na, Ni, Pb, S, Sb, Sn, Si, Te, Zn) has been constructed to perform different thermodynamic calculations required for the refining process. Thermodynamic description for eight of the selected binaries, Bi-Ca, Cu, Mn, Ni, Pb, S, Sb, and Sn, has been given in the current paper. Using the current database, different thermodynamic calculations have been performed to explain the steps involved in the bismuth refining process.

  9. Calculation of the production cross sections of high-spin isomeric states in hafnium

    SciTech Connect

    Chadwick, M.B.; Young, P.G. . Nuclear Physics Lab.; Los Alamos National Lab., NM )

    1989-01-01

    The J{sup {pi}} = 16{sup +} isomeric state in {sup 178}Hf(E{sub x} = 2.447 MeV), which has a halflife of 31 years, poses a threat for serious radioactive activation problems in some fusion reactor designs if its production in 14-MeV neutron reactions is significant. The relatively high excitation energy (2.447 MeV) of this state results in it lying in the continuum region, so it is necessary in a calculation to reconstruct the salient nuclear structure around the state, particularly rotational band levels that might be populated and would feed into it. Using preequilibrium and Hauser-Feshbach statistical theories, the cross sections for this and other hafnium isomeric states are calculated and compared with experimental measurements, where available. 13 refs., 6 figs., 3 tabs.

  10. Nuclear data production, calculation and measurement: a global overview of the gamma heating issue

    NASA Astrophysics Data System (ADS)

    Colombier, A.-C.; Amharrak, H.; Fourmentel, D.; Ravaux, S.; Régnier, D.; Gueton, O.; Hudelot, J.-P.; Lemaire, M.

    2013-03-01

    The gamma heating evaluation in different materials found in current and future generations of nuclear reactor (EPRTM, GENIV, MTR-JHR), is becoming an important issue especially for the design of many devices (control rod, heavy reflector, in-core & out-core experiments…). This paper deals with the works started since 2009 in the Reactor Studies Department of CEA Cadarache in ordre to answer to several problematic which have been identified as well for nuclear data production and calculation as for experimental measurement methods. The selected subjects are: Development of a Monte Carlo code (FIFRELIN) to simulate the prompt fission gamma emission which represents the major part of the gamma heating production inside the core Production and qualification of new evaluations of nuclear data especially for radiative capture and inelastic neutron scattering which are the main sources of gamma heating out-core Development and qualification of a recommended method for the total gamma heating calculation using the Monte Carlo simulation code TRIPOLI-4 Development, test and qualification of new devices dedicated to the in-core gamma heating measurement as well in MTR-JHR as in zero power facilities (EOLE-MINERVE) of CEA, Cadarache to increase the experimental measurement accuracy.

  11. An alternative radiometric method for calculating the sedimentation rates: application to an intertidal region (SW of Spain).

    PubMed

    Ligero, R A; Casas-Ruiz, M; Barrera, M; Barbero, L; Meléndez, M J

    2010-09-01

    A new method using the inventory determined for the activity of the radionuclide (137)Cs, coming from global radioactive fallout has been utilised to calculate the sedimentation rates. The method has been applied in a wide intertidal region in the Bay of Cádiz Natural Park (SW Spain). The sedimentation rates estimated by the (137)Cs inventory method ranged from 0.26 cm/year to 1.72 cm/year. The average value of the sedimentation rate obtained is 0.59 cm/year, and this rate has been compared with those resulting from the application of the (210)Pb dating technique. A good agreement between the two procedures has been found. From the study carried out, it has been possible for the first time, to draw a map of sedimentation rates for this zone where numerous physico-chemical, oceanographic and ecological studies converge, since it is situated in a region of great environmental interest. This area, which is representative of common environmental coastal scenarios, is particularly sensitive to perturbations related to climate change, and the results of the study will allow to make short and medium term evaluations of this change.

  12. Carbon Calculator for Land Use Change from Biofuels Production (CCLUB). Users' manual and technical documentation.

    SciTech Connect

    Mueller, S; Dunn, JB; Wang, M

    2012-06-07

    The Carbon Calculator for Land Use Change from Biofuels Production (CCLUB) calculates carbon emissions from land use change (LUC) for four different ethanol production pathways including corn grain ethanol and cellulosic ethanol from corn stover, miscanthus, and switchgrass. This document discusses the version of CCLUB released May 31, 2012 which includes corn, as did the previous CCLUB version, and three cellulosic feedstocks: corn stover, miscanthus, and switchgrass. CCLUB calculations are based upon two data sets: land change areas and above- and below-ground carbon content. Table 1 identifies where these data are stored and used within the CCLUB model, which is built in MS Excel. Land change area data is from Purdue University's Global Trade Analysis Project (GTAP) model, a computable general equilibrium (CGE) economic model. Section 2 describes the GTAP data CCLUB uses and how these data were modified to reflect shrubland transitions. Feedstock- and spatially-explicit below-ground carbon content data for the United States were generated with a surrogate model for CENTURY's soil organic carbon sub-model (Kwon and Hudson 2010) as described in Section 3. CENTURY is a soil organic matter model developed by Parton et al. (1987). The previous CCLUB version used more coarse domestic carbon emission factors. Above-ground non-soil carbon content data for forest ecosystems was sourced from the USDA/NCIAS Carbon Online Estimator (COLE) as explained in Section 4. We discuss emission factors used for calculation of international greenhouse gas (GHG) emissions in Section 5. Temporal issues associated with modeling LUC emissions are the topic of Section 6. Finally, in Section 7 we provide a step-by-step guide to using CCLUB and obtaining results.

  13. Relativistic many-body calculations of excitation energies and transition rates from core-excited states in copperlike ions

    NASA Astrophysics Data System (ADS)

    Safronova, U. I.; Johnson, W. R.; Shlyaptseva, A.; Hamasha, S.

    2003-05-01

    Energies of (3s23p63d94l4l'), (3s23p53d104l4l'), and (3s3p63d104l4l') states for Cu-like ions with Z=30 100 are evaluated to second order in relativistic many-body perturbation theory (RMBPT) starting from a Ni-like Dirac-Fock potential. Second-order Coulomb and Breit-Coulomb interactions are included. Correction for the frequency dependence of the Breit interaction is taken into account in lowest order. The Lamb shift correction to energies is also included in lowest order. Intrinsic particle-particle-hole contributions to energies are found to be 20 30 % of the sum of one- and two-body contributions. Transition rates and line strengths are calculated for the 3l-4l' electric-dipole (E1) transitions in Cu-like ions with nuclear charge Z=30 100. RMBPT including the Breit interaction is used to evaluate retarded E1 matrix elements in length and velocity forms. First-order RMBPT is used to obtain intermediate coupling coefficients, and second-order RMBPT is used to calculate transition matrix elements. A detailed discussion of the various contributions to the dipole- matrix elements and energy levels is given for copperlike tungsten (Z=74). The transition energies used in the calculation of oscillator strengths and transition rates are from second-order RMBPT. Trends of the transition rates as functions of Z are illustrated graphically for selected transitions. Comparisons are made with available experimental data. These atomic data are important in the modeling of M-shell radiation spectra of heavy ions generated in electron-beam ion trap experiments and in M-shell diagnostics of plasmas.

  14. Optimal Spray Application Rates for Ornamental Nursery Liner Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. Experiments were conducted on two and three-year old red maple liners. A traditional hydraulic sprayer with vertical booms was used t...

  15. New techniques for calculating heat and particle source rates due to neutral-beam injection in axisymmetric tokamaks

    SciTech Connect

    Goldston, R.J.; McCune, D.C.; Towner, H.H.; Davis, S.L.; Hawryluk, R.J.; Schmidt, G.L.

    1981-02-01

    A set of numerical techniques are described for calculating heat and particle source rates due to neutral beam injection in axisymmetric tokamaks. While these techniques consume a substantial amount of computer time, they take into account a number of significant, and normally neglected, effects. Examples of these effects are reionization of escaping charge exchanged beam particles, finite fast ion orbit excursions, beam deposition through collisions of beam neutrals with circulating beam ions, and the transport of thermal neutrals in the plasma due to charge changing collisions with beam ions.

  16. World Bank Atlas: Population, Per Capita Product and Growth Rates.

    ERIC Educational Resources Information Center

    World Bank, Washington, DC.

    The ninth edition of the World Bank Atlas shows estimates of population, gross national product, and per capita production of 189 countries and territories for 1972. The data presented in the atlas are the result of the work of the World Bank Group whose major purpose is to provide both financial and technical assistance and to improve the living…

  17. Comparison of calculated and experimentally resolved rate constants for excitation energy transfer in C-phycocyanin. 2. Trimers

    SciTech Connect

    Debreczeny, M.F.; Sauer, K.; Zhou, J.; Bryant, D.A.

    1995-05-18

    Resolution of the absorption spectrum of the {beta}{sub 155} chromophore in C-phycocyanin (PC) trimers is achieved by comparison of the steady state absorption spectra of ({alpha}{sup PC}{beta}{sup PC}){sub 3} and ({alpha}{sup PC}{beta}{sup *}){sub 3}. Comparison of the anisotropy decays of ({alpha}{sup PC}{beta}{sup PC}){sub 3} and ({alpha}{sup PC}{beta}{sup *}){sub 3} also greatly aids in the assignment of the dominant kinetic processes in PC trimers. A comparison is made of calculated Foerster rate constants for energy transfer with those rate constants resolved experimentally in the PC trimers. 35 refs.., 10 figs., 2 tabs.

  18. Comparison of calculated and experimentally resolved rate constants for excitation energy transfer in C-phycocyanin. 1. Monomers

    SciTech Connect

    Debreczeny, M.P.; Sauer, K.; Zhou, J.; Bryant, D.A.

    1995-05-18

    Rate constants for excitation energy transfer in light-harvesting protein, C-phycocyanin (PC), in the monomeric aggregation state, isolated from the cyanobacterium cynechococcus sp. PCC 7002, are calculated, using Foerster theory and compared with the results of time-resolved fluorescence measurements. The assignments of the energy-transfer rate constants in PC monomers are confirmed here by time-resolved fluorescence anisotropy measurements of the PC monomers isolated from both the wild-type and a mutant strain (cpcB/C155S) whose PC is missing the {beta}{sub 155} chromophore. It is concluded that the Foerster model of resonant energy transfer in the weak coupling limit successfully describes the dominant energy-transfer processes in this protein in the monomeric state. 31 refs., 3 figs., 4 tabs.

  19. Review of Uranium Hydriding and Dehydriding Rate Models in GOTH_SNF for Spent Fuel MCO Calculations

    SciTech Connect

    John R. Kirkpatrick; Chris A. Dahl

    2003-09-01

    The present report is one of a series of three. The series provides an independent technical review of certain aspects of the GOTH_SNF code that is used for accident analysis of the multicanister overpack (MCO) that is proposed for permanent storage of spent nuclear fuel in the planned repository at Yucca Mountain, Nevada. The work documented in the present report and its two companions was done under the auspices of the National Spent Nuclear Fuel Program. The other reports in the series are DOE/SNF/REP-087 and DOE/SNF/REP-088. This report analyzes the model for uranium hydriding and dissociation of the hydride that was documented in the SNF report titled MCO Work Book GOTH_SNF Input Data.1 Reference 1 used a single expression from a model by Bloch and Mintz for both the uranium hydriding and dehydriding reactions. This report compares the results of the GOTH_SNF expression for both phenomena with those from the models proposed by J. B. Condon and further developed by Condon and J. R. Kirkpatrick. The expression for the uranium hydriding rate used in GOTH_SNF (from the model of Bloch and Mintz) gives consistently lower values than those from the models of Condon and Kirkpatrick. This is true for all hydrogen pressures and for all temperatures. For a hydrogen pressure of 1 atm, the hydriding rates given by the models of Condon and Kirkpatrick are zero by the time the temperature reaches 400°C. That is, the term representing the dehydriding reaction has become large enough to overwhelm the term representing the hydriding reaction. The same is true for the expression used in GOTH_SNF. For lower hydrogen pressures, the hydriding rates reach zero at even lower temperatures for the Bloch and Mintz model and also for the Condon and Kirkpatrick models. Uranium dehydriding rates can be calculated for temperatures as high as 2,000°C. The dehydriding rates from GOTH_SNF contain an assumption that there is a 0.22 psia hydrogen pressure in the atmosphere surrounding the

  20. A particle-hole calculation for pion production in relativistic heavy-ion collisions

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Deutchman, P. A.; Townsend, L. W.

    1985-01-01

    A differential cross section for pi-meson production in peripheral heavy-ion collisions is formulated within the context of a particle-hole model in the Tamm-Dancoff approximation. This is the first attempt at a fully quantum-mechanical particle-hole calculation for pion production in relativistic heavy-ion collisions. The particular reaction studied is an O-16 projectile colliding with a C-12 target at rest. In the projectile a linear combination of isobar-hole states is formed, with the possibility of a coherent isobar giant resonance. The target can be excited to its giant M1 resonance (J-pi = 1(+), T = 1) at 15.11 MeV, or to its isobar analog neighbors, B-12 at 13.4 MeV and N-12 at 17.5 MeV. The theory is compared to recent experimental results.

  1. The Rate of Expanded Inner Speech During Spontaneous Sentence Productions.

    PubMed

    Netsell, Ronald; Kleinsasser, Steven; Daniel, Todd

    2016-10-01

    The rate of expanded inner speech and speech aloud was compared in 20 typical adults (3 males, 17 females; M age = 24 years, SD = 4). Participants generated and timed spontaneous sentences with both expanded inner speech and speech aloud following the instruction to say "the first thing that comes to mind." The rate of expanded inner speech was slightly, but significantly, faster than the rate of speech aloud. The findings supported the hypothesis that expanded inner speech was faster than speech aloud because of the time required to move the articulators in the latter. Physical measures of speaking rate are needed to validate self-timed measures. Limitations of the study and directions for research are discussed. PMID:27562695

  2. Calculated volatilization rates of fuel oxygenate compounds and other gasoline-related compounds from rivers and streams

    USGS Publications Warehouse

    Pankow, J.F.; Rathbun, R.E.; Zogorski, J.S.

    1996-01-01

    Large amounts of the 'fuel-oxygenate' compound methyl-tert-butyl ether (MTBE) are currently being used in gasoline to reduce carbon monoxide and ozone in urban air and to boost fuel octane. Because MTBE can be transported to surface waters in various ways, established theory was used to calculate half-lives for MTBE volatilizing from flowing surface waters. Similar calculations were made for benzene as a representative of the 'BTEX' group of compounds (benzene, toluene, ethyl benzene, and the xylenes), and for tert-butyl alcohol (TBA). The calculations were made as a function of the mean flow velocity u (m/day), the mean flow depth h (m), the ambient temperature, and the wind speed. In deep, slow-moving flows, MTBE volatilizes at rates which are similar to those for the BTEX compounds. In shallow, fast-moving flows, MTBE volatilizes more slowly than benzene, though in such flows both MTBE and benzene volatilize quickly enough that these differences may often not have much practical significance. TBA was found to be essentially nonvolatile from water.

  3. Long-lived activation products in TRIGA Mark II research reactor concrete shield: calculation and experiment

    NASA Astrophysics Data System (ADS)

    Žagar, Tomaž; Božič, Matjaž; Ravnik, Matjaž

    2004-12-01

    In this paper, a process of long-lived activity determination in research reactor concrete shielding is presented. The described process is a combination of experiment and calculations. Samples of original heavy reactor concrete containing mineral barite were irradiated inside the reactor shielding to measure its long-lived induced radioactivity. The most active long-lived (γ emitting) radioactive nuclides in the concrete were found to be 133Ba, 60Co and 152Eu. Neutron flux, activation rates and concrete activity were calculated for actual shield geometry for different irradiation and cooling times using TORT and ORIGEN codes. Experimental results of flux and activity measurements showed good agreement with the results of calculations. Volume of activated concrete waste after reactor decommissioning was estimated for particular case of Jožef Stefan Institute TRIGA reactor. It was observed that the clearance levels of some important long-lived isotopes typical for barite concrete (e.g. 133Ba, 41Ca) are not included in the IAEA and EU basic safety standards.

  4. An efficient nonclassical quadrature for the calculation of nonresonant nuclear fusion reaction rate coefficients from cross section data

    NASA Astrophysics Data System (ADS)

    Shizgal, Bernie D.

    2016-08-01

    Nonclassical quadratures based on a new set of half-range polynomials, Tn(x) , orthogonal with respect to w(x) =e - x - b /√{ x } for x ∈ [ 0 , ∞) are employed in the efficient calculation of the nuclear fusion reaction rate coefficients from cross section data. The parameter b = B /√{kB T } in the weight function is temperature dependent and B is the Gamow factor. The polynomials Tn(x) satisfy a three term recurrence relation defined by two sets of recurrence coefficients, αn and βn. These recurrence coefficients define in turn the tridiagonal Jacobi matrix whose eigenvalues are the quadrature points and the weights are calculated from the first components of the eigenfunctions. For nonresonant nuclear reactions for which the astrophysical function can be expressed as a lower order polynomial in the relative energy, the convergence of the thermal average of the reactive cross section with this nonclassical quadrature is extremely rapid requiring in many cases 2-4 quadrature points. The results are compared with other libraries of nuclear reaction rate coefficient data reported in the literature.

  5. Relativistic CI+all-order calculations of U III energies, g-factors, transition rates and lifetimes

    NASA Astrophysics Data System (ADS)

    Savukov, Igor; Safronova, Ulyana; Safronova, Marianna

    2016-05-01

    Excitation energies, term designations, g-factors, transition rates and lifetimes of U2+ are determined using a relativistic configuration interaction (CI) + all-order (linearized coupled-cluster, LCC) approach. The all-order energies are compared with CI+many-body-perturbation-theory (MBPT) and available experimental energies. Close agreement has been found with experiment, within hundreds of cm-1. In addition, lifetimes of higher levels have been calculated for comparison with three experimentally measured lifetimes, and close agreement was found within t he experimental error. CI-LCC calculations constitute a benchmark test of the CI+all-order method in complex relativistic systems such as actinides and their ions with many valence electrons. The theory yields many energy levels, g-factors, transition rates, and lifetimes of U2+ that are not available from experiment. The theory can be applied to other multi-valence atoms and ions, which would be of interest to many applications. The work of I. Savukov has been performed under the auspices of the U.S. DOE by LANL under Contract No. DE-AC52-06NA25396.M.S.S. acknowledges support from the Gordon Godfrey Fellowship program, UNSW and U.S. NSF Grant No. PHY-1404156.

  6. Summary of Simplified Two Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydrogen/Oxygen

    NASA Technical Reports Server (NTRS)

    Marek, C. John; Molnar, Melissa

    2005-01-01

    A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (greater than l x 10(exp -20)) moles per cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T(sub 4)). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/Air fuel and for H2/O2. A similar correlation is also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T(sub 4)) as a function of overall fuel/air ratio, pressure and initial temperature (T(sub 3)). High values of the regression coefficient R squared are obtained.

  7. Simplified Two-Time Step Method for Calculating Combustion Rates and Nitrogen Oxide Emissions for Hydrogen/Air and Hydorgen/Oxygen

    NASA Technical Reports Server (NTRS)

    Molnar, Melissa; Marek, C. John

    2005-01-01

    A simplified single rate expression for hydrogen combustion and nitrogen oxide production was developed. Detailed kinetics are predicted for the chemical kinetic times using the complete chemical mechanism over the entire operating space. These times are then correlated to the reactor conditions using an exponential fit. Simple first order reaction expressions are then used to find the conversion in the reactor. The method uses a two-time step kinetic scheme. The first time averaged step is used at the initial times with smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, temperature, and pressure. The second instantaneous step is used at higher water concentrations (> 1 x 10(exp -20) moles/cc) in the mixture which gives the chemical kinetic time as a function of the instantaneous fuel and water mole concentrations, pressure and temperature (T4). The simple correlations are then compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. This time is regressed over the complete initial conditions using the Excel regression routine. Chemical kinetic time equations for H2 and NOx are obtained for H2/air fuel and for the H2/O2. A similar correlation is also developed using data from NASA s Chemical Equilibrium Applications (CEA) code to determine the equilibrium temperature (T4) as a function of overall fuel/air ratio, pressure and initial temperature (T3). High values of the regression coefficient R2 are obtained.

  8. Effects of chemical compositions and ensiling on the biogas productivity and degradation rates of agricultural and food processing by-products.

    PubMed

    Kafle, Gopi Krishna; Kim, Sang Hun

    2013-08-01

    The objective of this study was to investigate the effects of chemical compositions and ensiling on the biogas productivity and degradation rates of agricultural and food processing by-products (AFPBPs) using the biogas potential test. The AFPBPs were classified based on their chemical compositions (i.e., carbohydrate, protein and fat contents). The biogas and methane potentials of AFPBPs were calculated to range from 450 to 777 mL/g volatile solids (VS) and 260-543 mL/g VS, respectively. AFPBPs with high fat and protein contents produced significantly higher amounts of biogas than AFPBPs with high carbohydrate and low fat contents. The degradation rate was faster for AFPBPs with high carbohydrate contents compared to AFPBPs with high protein and fat contents. The lag phase and biogas production duration were lower when using ensiled AFPBPs than when using nonsilage AFPBPs. Among the four different silages tested, two silages significantly improved biogas production compared to the nonsilage AFPBPs.

  9. High rate of methane leakage from natural gas production

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-10-01

    Natural gas production is growing as the United States seeks domestic sources of relatively clean energy. Natural gas combustion produces less carbon dioxide emissions than coal or oil for the amount of energy produced. However, one source of concern is that some natural gas leaks to the atmosphere from the extraction point, releasing methane, a potent greenhouse gas.

  10. 75 FR 47650 - International Product Change-Global Expedited Package Services-Non-Published Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... Product Change--Global Expedited Package Services-- Non-Published Rates AGENCY: Postal Service\\TM\\ ACTION... Commission to add Global Expedited Package Services Contracts--Non-Published Rates to the Competitive... Service to add Global Expedited Package Contracts--Non-Published Rates to the Competitive Products...

  11. 30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Supervisor limit my well or reservoir production rates? (a) The Regional Supervisor may set a Maximum Production Rate (MPR) for a producing well completion, or set a Maximum Efficient Rate (MER) for a reservoir... 30 Mineral Resources 2 2011-07-01 2011-07-01 false May the Regional Supervisor limit my well...

  12. Quantifying melt production and degassing rate at mid-ocean ridges from global mantle convection models with plate motion history

    NASA Astrophysics Data System (ADS)

    Li, Mingming; Black, Benjamin; Zhong, Shijie; Manga, Michael; Rudolph, Maxwell L.; Olson, Peter

    2016-07-01

    The Earth's surface volcanism exerts first-order controls on the composition of the atmosphere and the climate. On Earth, the majority of surface volcanism occurs at mid-ocean ridges. In this study, based on the dependence of melt fraction on temperature, pressure, and composition, we compute melt production and degassing rate at mid-ocean ridges from three-dimensional global mantle convection models with plate motion history as the surface velocity boundary condition. By incorporating melting in global mantle convection models, we connect deep mantle convection to surface volcanism, with deep and shallow mantle processes internally consistent. We compare two methods to compute melt production: a tracer method and an Eulerian method. Our results show that melt production at mid-ocean ridges is mainly controlled by surface plate motion history, and that changes in plate tectonic motion, including plate reorganizations, may lead to significant deviation of melt production from the expected scaling with seafloor production rate. We also find a good correlation between melt production and degassing rate beneath mid-ocean ridges. The calculated global melt production and CO2 degassing rate at mid-ocean ridges varies by as much as a factor of 3 over the past 200 Myr. We show that mid-ocean ridge melt production and degassing rate would be much larger in the Cretaceous, and reached maximum values at ˜150-120 Ma. Our results raise the possibility that warmer climate in the Cretaceous could be due in part to high magmatic productivity and correspondingly high outgassing rates at mid-ocean ridges during that time.

  13. Calculated cancer risks for conventional and "potentially reduced exposure product" cigarettes.

    PubMed

    Pankow, James F; Watanabe, Karen H; Toccalino, Patricia L; Luo, Wentai; Austin, Donald F

    2007-03-01

    Toxicant deliveries (by machine smoking) are compiled and associated cancer risks are calculated for 13 carcinogens from 26 brands of conventional cigarettes categorized as "regular" (R), "light" (Lt), or "ultralight" (ULt), and for a reference cigarette. Eight "potentially reduced exposure product" (PREP) cigarettes are also considered. Because agency-to-agency differences exist in the cancer slope factor (CSF) values adopted for some carcinogens, two CSF sets were used in the calculations: set I [U.S. Environmental Protection Agency (EPA)-accepted values plus California EPA-accepted values as needed to fill data gaps] and set II (vice versa). The potential effects of human smoking patterns on cigarette deliveries are considered. Acetaldehyde, 1,3-butadiene, and acrylonitrile are associated with the largest calculated cancer risks for all 26 brands of conventional cigarettes. The calculated risks are proportional to the smoking dose z (pack-years). Using CSF set I and z = 1 pack-year (7,300 cigarettes), the calculated brand-average incremental lifetime cancer risk ILCR(1)(acetaldehyde) values are R, 6 x 10(-5); Lt, 5 x 10(-5); and ULt, 3 x 10(-5) (cf. typical U.S. EPA risk benchmark of 10(-6)). These values are similar, especially given the tendency of smokers to "compensate" when smoking Lt and ULt cigarettes. ILCR(1)(subSigma-lung) is the brand-average per pack-year subtotal risk for the measured human lung carcinogens. Using CSF set I, the ILCR(1)(subSigma-lung) values for R, Lt, and ULt cigarettes account for

  14. SAW with multiple electrodes achieves high production rates

    SciTech Connect

    Tusek, J.

    1996-08-01

    Increased demands for higher productivity in the production of welded structures dictate the use of new higher-performance welding procedures. Submerged arc welding (SAW) is already one of the highest performing arc welding processes, but with certain improved variants, its performance can be increased. These variants are multiple-head welding, double electrode welding and submerged arc welding with metal powder addition. These three variations of submerged arc welding have been put into practice and are extensively treated in the welding literature. The application of welding with more than three wires in a joint contact tube is rare, however, and rarely mentioned. The purpose of this article is to show the basic characteristics and eventual applications of SAW using multiple electrodes.

  15. Calculation of. beta. -ray absorbed dose rate for /sup 131/I applied to the inflorescence of Tradescantia

    SciTech Connect

    Bingo, K.; Tano, S.; Numakunai, T.; Yoshida, Y.; Yamaguchi, H.

    1981-03-01

    Effects of /sup 131/I applied to the inflorescence on the induction of somatic mutations in Tradescantia stamen hairs were previously investigated, and the doubling dose (activity) was estimated to be 4 nCi. In the present paper, the absorbed dose rate in stamen hairs of Tradescantia for ..beta.. rays from the applied /sup 131/I was calculated. The doubling dose for the /sup 131/I (4 nCi) applied to the inflorescence was estimated to be higher than 0.3 rad (assuming uniform distribution of /sup 131/I on the surface of the buds and assuming that the shape of the buds was a sphere) and lower than 1.0 rad.

  16. Ring-Polymer Molecular Dynamics Rate Coefficient Calculations for Insertion Reactions: X + H2 → HX + H (X = N, O).

    PubMed

    Li, Yongle; Suleimanov, Yury V; Guo, Hua

    2014-02-20

    The thermal rate constants of two prototypical insertion-type reactions, namely, N/O + H2 → NH/OH + H, are investigated with ring polymer molecular dynamics (RPMD) on full-dimensional potential energy surfaces using recently developed RPMDrate code. It is shown that the unique ability of the RPMD approach among the existing theoretical methods to capture the quantum effects, e.g., tunneling and zero-point energy, as well as recrossing dynamics quantum mechanically with ring-polymer trajectories leads to excellent agreement with rigorous quantum dynamics calculations. The present result is encouraging for future applications of the RPMD method and the RPMDrate code to complex-forming chemical reactions involving polyatomic reactants.

  17. Measured and Calculated Neutron Spectra and Dose Equivalent Rates at High Altitudes; Relevance to SST Operations and Space Research

    NASA Technical Reports Server (NTRS)

    Foelsche, T.; Mendell, R. B.; Wilson, J. W.; Adams, R. R.

    1974-01-01

    Results of the NASA Langley-New York University high-altitude radiation study are presented. Measurements of the absorbed dose rate and of secondary fast neutrons (1 to 10 MeV energy) during the years 1965 to 1971 are used to determine the maximum radiation exposure from galactic and solar cosmic rays of supersonic transport (SST) and subsonic jet occupants. The maximum dose equivalent rates that the SST crews might receive turn out to be 13 to 20 percent of the maximum permissible dose rate (MPD) for radiation workers (5 rem/yr). The exposure of passengers encountering an intense giant-energy solar particle event could exceed the MPD for the general population (0.5 rem/yr), but would be within these permissible limits if in such rare cases the transport descends to subsonic altitude; it is in general less than 12 percent of the MPD. By Monte Carlo calculations of the transport and buildup of nucleons in air for incident proton energies E of 0.02 to 10 GeV, the measured neutron spectra were extrapolated to lower and higher energies and for galactic cosmic rays were found to continue with a relatively high intensity to energies greater than 400 MeV, in a wide altitude range. This condition, together with the measured intensity profiles of fast neutrons, revealed that the biologically important fast and energetic neutrons penetrate deep into the atmosphere and contribute approximately 50 percent of the dose equivalant rates at SST and present subsonic jet altitudes.

  18. Effects of track structure and cell inactivation on the calculation of heavy ion mutation rates in mammalian cells

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Wilson, J. W.; Shavers, M. R.; Katz, R.

    1996-01-01

    It has long been suggested that inactivation severely effects the probability of mutation by heavy ions in mammalian cells. Heavy ions have observed cross sections of inactivation that approach and sometimes exceed the geometric size of the cell nucleus in mammalian cells. In the track structure model of Katz the inactivation cross section is found by summing an inactivation probability over all impact parameters from the ion to the sensitive sites within the cell nucleus. The inactivation probability is evaluated using the dose-response of the system to gamma-rays and the radial dose of the ions and may be equal to unity at small impact parameters for some ions. We show how the effects of inactivation may be taken into account in the evaluation of the mutation cross sections from heavy ions in the track structure model through correlation of sites for gene mutation and cell inactivation. The model is fit to available data for HPRT mutations in Chinese hamster cells and good agreement is found. The resulting calculations qualitatively show that mutation cross sections for heavy ions display minima at velocities where inactivation cross sections display maxima. Also, calculations show the high probability of mutation by relativistic heavy ions due to the radial extension of ions track from delta-rays in agreement with the microlesion concept. The effects of inactivation on mutations rates make it very unlikely that a single parameter such as LET or Z*2/beta(2) can be used to specify radiation quality for heavy ion bombardment.

  19. Cross section calculations for subthreshold pion production in peripheral heavy-ion collisions

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Cucinotta, F. A.; Deutchman, P. A.; Townsend, L. W.

    1986-01-01

    Total cross sections angular distributions, and spectral distributions for the exclusive production of charged and neutral subthreshold pions produced in peripheral nucleus-nucleus collisions are calculated by using a particle-hole formalism. The pions result from the formation and decay of an isobar giant resonance state formed in a C-12 nucleus. From considerations of angular momentum conservation and for the sake of providing a unique experimental signature, the other nucleus, chosen for this work to be C-12 also, is assumed to be excited to one of its isovector (1+) giant resonance states. The effects of nucleon recoil by the pion emission are included, and Pauli blocking and pion absorption effects are studied by varying the isobar width. Detailed comparisons with experimental subthreshold pion data for incident energies between 35 and 86 MeV/nucleon are made.

  20. Comparison of optics and electronics for the calculation of matrix-vector products

    NASA Technical Reports Server (NTRS)

    Gary, C. K.

    1992-01-01

    Optical processors are attractive because of their ability to perform massively parallel operations such as matrix vector products. The inherently analog nature of optical calculations requires that optical processors be based on analog computations. While the speed at which such analog operations can be performed as well as the natural parallelism of optical systems are great advantages of optical processors, the analog representation of values severely limits the achievable accuracy. Furthermore, optical processors are limited by the need to convert information to and from the intensity of light. Digitization can be used to increase the accuracy of optical matrix-vector processors, but causes a severe reduction in speed. This paper compares the throughput and power requirements of optical and electronic processors, showing that optical matrix-vector processors can provide a greater number of operations/Watt than conventional electronics.

  1. Effects of culture (China vs. US) and task on perceived hazard: Evidence from product ratings, label ratings, and product to label matching.

    PubMed

    Lesch, Mary F; Rau, Pei-Luen Patrick; Choi, YoonSun

    2016-01-01

    In the current study, 44 Chinese and 40 US college students rated their perceived hazard in response to warning labels and products and attempted to match products with warning labels communicating the same level of hazard. Chinese participants tended to provide lower ratings of hazard in response to labels, but hazard perceived in response to products did not significantly differ as a function of culture. When asked to match a product with a warning label, Chinese participants' hazard perceptions appeared to be better calibrated, than did US participants', across products and labels. The results are interpreted in terms of constructivist theory which suggests that risk perceptions vary depending on the "frame of mind" evoked by the environment/context. Designers of warnings must be sensitive to the fact that product users' cognitive representations develop within a culture and that risk perceptions will vary based on the context in which they are derived. PMID:26360193

  2. Effects of culture (China vs. US) and task on perceived hazard: Evidence from product ratings, label ratings, and product to label matching.

    PubMed

    Lesch, Mary F; Rau, Pei-Luen Patrick; Choi, YoonSun

    2016-01-01

    In the current study, 44 Chinese and 40 US college students rated their perceived hazard in response to warning labels and products and attempted to match products with warning labels communicating the same level of hazard. Chinese participants tended to provide lower ratings of hazard in response to labels, but hazard perceived in response to products did not significantly differ as a function of culture. When asked to match a product with a warning label, Chinese participants' hazard perceptions appeared to be better calibrated, than did US participants', across products and labels. The results are interpreted in terms of constructivist theory which suggests that risk perceptions vary depending on the "frame of mind" evoked by the environment/context. Designers of warnings must be sensitive to the fact that product users' cognitive representations develop within a culture and that risk perceptions will vary based on the context in which they are derived.

  3. Study of erosion rate, erosion products, and arc velocity under transverse magnetic field in vacuum

    NASA Astrophysics Data System (ADS)

    Chang, Rongfeng

    1993-01-01

    The advantages of the cathodic arc-coating method include high energy efficiency, high film deposition rates, and good film-to-substrate adhesion. The principal shortcoming of the arc-coating method is that macroparticles are deposited on the substrate as part of the film. The presence of the macroparticles in the coated film degrades film quality which is particularly severe when the deposition process relies on a reaction to form a compound material as the coating. In this case, the macroparticles contain unreacted metal cores which represent impurities in the coated film. This research attempts to identify methods to eliminate or reduce the formation of macroparticles in the coated film by reaching an understanding of the behavior of macroparticles and the angular distribution of erosion products. A transverse magnetic field has been applied to control the arc motion. This reduces the cathode erosion rate and also the formation of macroparticles. The angular distributions of erosion products, i.e. metal ions and macroparticles, are measured to determine the optimum position for the specimens to be coated, and to better understand the cathode spot characteristics. The arc velocity is also measured to determine the effect of the transverse magnetic field on the cathode erosion rate. The variation of the solid angle which the probe represents with respect to the cathode spot when it moves spirally over the cathode surface has been calculated, and it has been shown that the macroscopic measurements can be used to correlate with the microscopic phenomena of the cathode spot. The cooling of macroparticles during the time of flight from the cathode spot to the substrate has been calculated taking into account evaporation and radiation. In general, the low melting point materials produce large macroparticles and high melting point materials produce small ones. It is easier to reduce the number of macroparticles coated on the substrate for low melting point materials

  4. Study of Erosion Rate, Erosion Products, and Arc Velocity Under Transverse Magnetic Field in Vacuum

    NASA Astrophysics Data System (ADS)

    Chang, Rongfeng

    The advantages of the cathodic arc-coating method include high energy efficiency, high film deposition rates, and good film-to-substrate adhesion. The principal shortcoming of the arc-coating method is that macroparticles are deposited on the substrate as part of the film. The presence of the macroparticles in the coated film degrades film quality which is particularly severe when the deposition process relies on a reaction to form a compound material as the coating. In this case, the macroparticles contain unreacted metal cores which represent impurities in the coated film. This research attempts to identify methods to eliminate or reduce the formation of macroparticles in the coated film by reaching an understanding of the behavior of macroparticles and the angular distribution of erosion products. A transverse magnetic field has been applied to control the arc motion. This reduces the cathode erosion rate and also the formation of macroparticles. The angular distributions of erosion products, i.e. metal ions and macroparticles, are measured to determine the optimum position for the specimens to be coated, and to better understand the cathode spot characteristics. The arc velocity is also measured to determine the effect of the transverse magnetic field on the cathode erosion rate. The variation of the solid angle which the probe represents with respect to the cathode spot when it moves spirally over the cathode surface has been calculated, and it has been shown that the macroscopic measurements can be used to correlate with the microscopic phenomena of the cathode spot. The cooling of macroparticles during the time of flight from the cathode spot to the substrate has been calculated taking into account evaporation and radiation. In general, the low melting point materials produce large macroparticles and high melting point materials produce small ones. It is easier to reduce the number of macroparticles coated on the substrate for low melting point materials

  5. HDRMC, an accelerated Monte Carlo dose calculator for high dose rate brachytherapy with CT-compatible applicators

    SciTech Connect

    Chibani, Omar C-M Ma, Charlie

    2014-05-15

    Purpose: To present a new accelerated Monte Carlo code for CT-based dose calculations in high dose rate (HDR) brachytherapy. The new code (HDRMC) accounts for both tissue and nontissue heterogeneities (applicator and contrast medium). Methods: HDRMC uses a fast ray-tracing technique and detailed physics algorithms to transport photons through a 3D mesh of voxels representing the patient anatomy with applicator and contrast medium included. A precalculated phase space file for the{sup 192}Ir source is used as source term. HDRM is calibrated to calculated absolute dose for real plans. A postprocessing technique is used to include the exact density and composition of nontissue heterogeneities in the 3D phantom. Dwell positions and angular orientations of the source are reconstructed using data from the treatment planning system (TPS). Structure contours are also imported from the TPS to recalculate dose-volume histograms. Results: HDRMC was first benchmarked against the MCNP5 code for a single source in homogenous water and for a loaded gynecologic applicator in water. The accuracy of the voxel-based applicator model used in HDRMC was also verified by comparing 3D dose distributions and dose-volume parameters obtained using 1-mm{sup 3} versus 2-mm{sup 3} phantom resolutions. HDRMC can calculate the 3D dose distribution for a typical HDR cervix case with 2-mm resolution in 5 min on a single CPU. Examples of heterogeneity effects for two clinical cases (cervix and esophagus) were demonstrated using HDRMC. The neglect of tissue heterogeneity for the esophageal case leads to the overestimate of CTV D90, CTV D100, and spinal cord maximum dose by 3.2%, 3.9%, and 3.6%, respectively. Conclusions: A fast Monte Carlo code for CT-based dose calculations which does not require a prebuilt applicator model is developed for those HDR brachytherapy treatments that use CT-compatible applicators. Tissue and nontissue heterogeneities should be taken into account in modern HDR

  6. A parallel code to calculate rate-state seismicity evolution induced by time dependent, heterogeneous Coulomb stress changes

    NASA Astrophysics Data System (ADS)

    Cattania, C.; Khalid, F.

    2016-09-01

    The estimation of space and time-dependent earthquake probabilities, including aftershock sequences, has received increased attention in recent years, and Operational Earthquake Forecasting systems are currently being implemented in various countries. Physics based earthquake forecasting models compute time dependent earthquake rates based on Coulomb stress changes, coupled with seismicity evolution laws derived from rate-state friction. While early implementations of such models typically performed poorly compared to statistical models, recent studies indicate that significant performance improvements can be achieved by considering the spatial heterogeneity of the stress field and secondary sources of stress. However, the major drawback of these methods is a rapid increase in computational costs. Here we present a code to calculate seismicity induced by time dependent stress changes. An important feature of the code is the possibility to include aleatoric uncertainties due to the existence of multiple receiver faults and to the finite grid size, as well as epistemic uncertainties due to the choice of input slip model. To compensate for the growth in computational requirements, we have parallelized the code for shared memory systems (using OpenMP) and distributed memory systems (using MPI). Performance tests indicate that these parallelization strategies lead to a significant speedup for problems with different degrees of complexity, ranging from those which can be solved on standard multicore desktop computers, to those requiring a small cluster, to a large simulation that can be run using up to 1500 cores.

  7. Determination of equilibrium electron temperature and times using an electron swarm model with BOLSIG+ calculated collision frequencies and rate coefficients

    SciTech Connect

    Pusateri, Elise N.; Morris, Heidi E.; Nelson, Eric M.; Ji, Wei

    2015-08-04

    Electromagnetic pulse (EMP) events produce low-energy conduction electrons from Compton electron or photoelectron ionizations with air. It is important to understand how conduction electrons interact with air in order to accurately predict EMP evolution and propagation. An electron swarm model can be used to monitor the time evolution of conduction electrons in an environment characterized by electric field and pressure. Here a swarm model is developed that is based on the coupled ordinary differential equations (ODEs) described by Higgins et al. (1973), hereinafter HLO. The ODEs characterize the swarm electric field, electron temperature, electron number density, and drift velocity. Important swarm parameters, the momentum transfer collision frequency, energy transfer collision frequency, and ionization rate, are calculated and compared to the previously reported fitted functions given in HLO. These swarm parameters are found using BOLSIG+, a two term Boltzmann solver developed by Hagelaar and Pitchford (2005), which utilizes updated cross sections from the LXcat website created by Pancheshnyi et al. (2012). We validate the swarm model by comparing to experimental effective ionization coefficient data in Dutton (1975) and drift velocity data in Ruiz-Vargas et al. (2010). In addition, we report on electron equilibrium temperatures and times for a uniform electric field of 1 StatV/cm for atmospheric heights from 0 to 40 km. We show that the equilibrium temperature and time are sensitive to the modifications in the collision frequencies and ionization rate based on the updated electron interaction cross sections.

  8. Determination of equilibrium electron temperature and times using an electron swarm model with BOLSIG+ calculated collision frequencies and rate coefficients

    NASA Astrophysics Data System (ADS)

    Pusateri, Elise N.; Morris, Heidi E.; Nelson, Eric M.; Ji, Wei

    2015-08-01

    Electromagnetic pulse (EMP) events produce low-energy conduction electrons from Compton electron or photoelectron ionizations with air. It is important to understand how conduction electrons interact with air in order to accurately predict EMP evolution and propagation. An electron swarm model can be used to monitor the time evolution of conduction electrons in an environment characterized by electric field and pressure. Here a swarm model is developed that is based on the coupled ordinary differential equations (ODEs) described by Higgins et al. (1973), hereinafter HLO. The ODEs characterize the swarm electric field, electron temperature, electron number density, and drift velocity. Important swarm parameters, the momentum transfer collision frequency, energy transfer collision frequency, and ionization rate, are calculated and compared to the previously reported fitted functions given in HLO. These swarm parameters are found using BOLSIG+, a two term Boltzmann solver developed by Hagelaar and Pitchford (2005), which utilizes updated cross sections from the LXcat website created by Pancheshnyi et al. (2012). We validate the swarm model by comparing to experimental effective ionization coefficient data in Dutton (1975) and drift velocity data in Ruiz-Vargas et al. (2010). In addition, we report on electron equilibrium temperatures and times for a uniform electric field of 1 StatV/cm for atmospheric heights from 0 to 40 km. It is shown that the equilibrium temperature and time are sensitive to the modifications in the collision frequencies and ionization rate based on the updated electron interaction cross sections.

  9. Determination of equilibrium electron temperature and times using an electron swarm model with BOLSIG+ calculated collision frequencies and rate coefficients

    DOE PAGES

    Pusateri, Elise N.; Morris, Heidi E.; Nelson, Eric M.; Ji, Wei

    2015-08-04

    Electromagnetic pulse (EMP) events produce low-energy conduction electrons from Compton electron or photoelectron ionizations with air. It is important to understand how conduction electrons interact with air in order to accurately predict EMP evolution and propagation. An electron swarm model can be used to monitor the time evolution of conduction electrons in an environment characterized by electric field and pressure. Here a swarm model is developed that is based on the coupled ordinary differential equations (ODEs) described by Higgins et al. (1973), hereinafter HLO. The ODEs characterize the swarm electric field, electron temperature, electron number density, and drift velocity. Importantmore » swarm parameters, the momentum transfer collision frequency, energy transfer collision frequency, and ionization rate, are calculated and compared to the previously reported fitted functions given in HLO. These swarm parameters are found using BOLSIG+, a two term Boltzmann solver developed by Hagelaar and Pitchford (2005), which utilizes updated cross sections from the LXcat website created by Pancheshnyi et al. (2012). We validate the swarm model by comparing to experimental effective ionization coefficient data in Dutton (1975) and drift velocity data in Ruiz-Vargas et al. (2010). In addition, we report on electron equilibrium temperatures and times for a uniform electric field of 1 StatV/cm for atmospheric heights from 0 to 40 km. We show that the equilibrium temperature and time are sensitive to the modifications in the collision frequencies and ionization rate based on the updated electron interaction cross sections.« less

  10. Re-evaluating Primary Biotic Resource Use for Marine Biomass Production: A New Calculation Framework.

    PubMed

    Luong, Anh D; Schaubroeck, Thomas; Dewulf, Jo; De Laender, Frederik

    2015-10-01

    The environmental impacts of biomass harvesting can be quantified through the amount of net primary production required to produce one unit of harvested biomass (SPPR-specific primary production required). This paper presents a new calculation framework that explicitly takes into account full food web complexity and shows that the resulting SPPR for toothed whales in the Icelandic marine ecosystem is 2.8 times higher than the existing approach based on food web simplification. In addition, we show that our new framework can be coupled to food web modeling to examine how uncertainty on ecological data and processes can be accounted for while estimating SPPR. This approach reveals that an increase in the degree of heterotrophy by flagellates from 0% to 100% results in a two-fold increase in SPPR estimates in the Barents Sea. It also shows that the estimated SPPR is between 3.9 (herring) and 5.0 (capelin) times higher than that estimated when adopting food chain theory. SPPR resulting from our new approach is only valid for the given time period for which the food web is modeled and cannot be used to infer changes in SPPR when the food web is altered by changes in human exploitation or environmental changes. PMID:26348118

  11. Giotto IMS measurements of the production rate of hydrogen cyanide in the coma of Comet Halley

    NASA Technical Reports Server (NTRS)

    Ip, W.-H.; Balsiger, H.; Geiss, J.; Goldstein, B. E.; Kettmann, G.

    1990-01-01

    The ion composition measurements in the ionosphere of Comet Halley by the ion mass spectrometer (IMS) experiment on the Giotto spacecraft are used to estimate the relative abundance of HCN. From a comparison of the normalized number density of ions with mass-to-charge (M/q) ratio of 28 AMU/e with steady-state photochemical models, it can be determined that the production rate of HCN directly from the central nucleus is Q(HCN) is less than about 0.0002 Q(H2O) at the time of Giotto encounter. The related photochemical- model calculations also indicate that Q(NH3)/Q(H2O) at the time of Giotto encounter. The related photo-chemical model calculations also indicate that Q(HN3)/Q(H2O) equals about 0.005, in agreement with recent determination from ground-based observations. The estimated value of Q(HCN) is lower than the relative abundance of Q(HCN)/Q(H2O) of about 0.001, as derived from radio observations of the 88.6 GHz emission of the J = 1 - 0 transition of HCN. The difference may be the result of time variations of the coma composition and dynamics, as well as other model-dependent effects.

  12. Determination of electron production rates caused by cosmic ray particles in ionospheres of terrestrial planets

    NASA Astrophysics Data System (ADS)

    Velinov, P. I. Y.; Buchvarova, M. B.; Mateev, L.; Ruder, H.

    Cosmic rays (CR) create the lower parts of planetary ionospheres. The observed CR spectrum can be distributed into the following five intervals: I ( E = 3.10 6 — 10 11 GeV/n), II ( E = 3.10 2 — 3.10 6 GeV/n), III ( E = 30 MeV/n — 3.10 2GeV/n), IV ( E = 1 — 30 MeV/n) and V ( E = 10 KeV/n — 1 MeV/n), where E is the kinetic energy of the particles (Dorman, 1977; Velinov, 2000). Some methods exist for calculating ionization by relativistic particles in CR intervals I, II and III. For the high latitude and polar ionosphere, however, intervals III, IV and V are also significant since they contain solar cosmic ray and anomalous cosmic ray components. Formulas for the electron production rate q (cm -3s -1) at height h in the planetary ionosphere as a result of penetration of energetic particles from intervals III, IV and V are deduced in this paper. For this purpose the law of particle energy transformation by penetration through the ionosphere — atmosphere system is obtained. A model for the calculation of the cosmic ray spectrum on the basis of satellite measurements is created. This computed analytical model gives a practical possibility for investigation of experimental data from measurements of galactic cosmic rays and their anomalous component.

  13. HyPEP-FY 07 Annual Report: A Hydrogen Production Plant Efficiency Calculation Program

    SciTech Connect

    Chang Oh

    2007-09-01

    The Very High Temperature Gas-Cooled Reactor (VHTR) coupled to the High Temperature Steam Electrolysis (HTSE) process is one of two reference integrated systems being investigated by the U.S. Department of Energy and Idaho National Laboratory for the production of hydrogen. In this concept the VHTR outlet temperature of 900 °C provides thermal energy and high efficiency electricity for the electrolysis of steam in the HTSE process. In the second reference system the Sulfur Iodine (SI) process is coupled to the VHTR to produce hydrogen thermochemically. In the HyPEP project we are investigating and characterizing these two reference systems with respect to production, operability, and safety performance criteria. Under production, plant configuration and working fluids are being studied for their effect on efficiency. Under operability, control strategies are being developed with the goal of maintaining equipment within operating limits while meeting changes in demand. Safety studies are to investigate plant response for equipment failures. Specific objectives in FY07 were (1) to develop HyPEP Beta and verification and validation (V&V) plan, (2) to perform steady state system integration, (3) to perform parametric studies with various working fluids and power conversion unit (PCU) configurations, (4) the study of design options such as pressure, temperature, etc. (5) to develop a control strategy and (6) to perform transient analyses for plant upsets, control strategy, etc for hydrogen plant with PCU. This report describes the progress made in FY07 in each of the above areas. (1) The HyPEP code numeric scheme and Graphic User Interface have been tested and refined since the release of the alpha version a year ago. (2) The optimal size and design condition for the intermediate heat exchanger, one of the most important components for integration of the VHTR and HTSE plants, was estimated. (3) Efficiency calculations were performed for a variety of working fluids for

  14. Estimating rates of biologically driven coral reef framework production and erosion: a new census-based carbonate budget methodology and applications to the reefs of Bonaire

    NASA Astrophysics Data System (ADS)

    Perry, C. T.; Edinger, E. N.; Kench, P. S.; Murphy, G. N.; Smithers, S. G.; Steneck, R. S.; Mumby, P. J.

    2012-09-01

    Census-based approaches can provide important measures of the ecological processes controlling reef carbonate production states. Here, we describe a rapid, non-destructive approach to carbonate budget assessments, termed ReefBudget that is census-based and which focuses on quantifying the relative contributions made by different biological carbonate producer/eroder groups to net reef framework carbonate production. The methodology is presently designed only for Caribbean sites, but has potential to be adapted for use in other regions. Rates are calculated using data on organism cover and abundance, combined with annual extension or production rate measures. Set against this are estimates of the rates at which bioeroding species of fish, urchins and internal substrate borers erode reef framework. Resultant data provide a measure of net rates of biologically driven carbonate production (kg CaCO3 m-2 year-1). These data have potential to be integrated into ecological assessments of reef state, to aid monitoring of temporal (same-site) changes in rates of biological carbonate production and to provide insights into the key ecological drivers of reef growth or erosion as a function of environmental change. Individual aspects of the budget methodology can also be used alongside other census approaches if deemed appropriate for specific study aims. Furthermore, the methodology spreadsheets are user-changeable, allowing local or new process/rate data to be integrated into calculations. Application of the methodology is considered at sites around Bonaire. Highest net rates of carbonate production, +9.52 to +2.30 kg CaCO3 m-2 year-1, were calculated at leeward sites, whilst lower rates, +0.98 to -0.98 kg CaCO3 m-2 year-1, were calculated at windward sites. Data are within the ranges calculated in previous budget studies and provide confidence in the production estimates the methodology generates.

  15. Calculation of excitation functions of proton, alpha and deuteron induced reactions for production of medical radioisotopes 122-125I

    NASA Astrophysics Data System (ADS)

    Artun, Ozan; Aytekin, Hüseyin

    2015-02-01

    In this work, the excitation functions for production of medical radioisotopes 122-125I with proton, alpha, and deuteron induced reactions were calculated by two different level density models. For the nuclear model calculations, the Talys 1.6 code were used, which is the latest version of Talys code series. Calculations of excitation functions for production of the 122-125I isotopes were carried out by using the generalized superfluid model (GSM) and Fermi-gas model (FGM). The results have shown that generalized superfluid model is more successful than Fermi-gas model in explaining the experimental results.

  16. Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

    USGS Publications Warehouse

    Siegel, D.I.; Chanton, J.P.; Glaser, P.H.; Chasar, L.S.; Rosenberry, D.O.

    2001-01-01

    Raised bogs and municipal waste landfills harbor large populations of methanogens within their domed deposits of anoxic organic matter. Although the methane emissions from these sites have been estimated by various methods, limited data exist on the activity of the methanogens at depth. We therefore analyzed the stable isotopic signature of the pore waters in two raised bogs from northern Minnesota to identify depth intervals in the peat profile where methanogenic metabolism occurs. Methanogenesis enriched the deuterium (2H) content of the deep peat pore waters by as much as +11% (Vienna Standard Mean Sea Water), which compares to a much greater enrichment factor of +70% in leachate from New York City's Fresh Kills landfill. The bog pore waters were isotopically dated by tritium (3H) to be about 35 years old at 1.5 m depth, whereas the landfill leachate was estimated as ~ 17 years old from Darcy flow calculations. According to an isotopic mass balance the observed deuterium enrichment indicates that about 1.2 g of CH4m-3 d-1 were produced within the deeper peat, compared to about 2.8 g CH4 m-3 d-1 in the landfill. The values for methane production in the bog peat are substantially higher than the flux rates measured at the surface of the bogs or at the landfill, indicating that deeper methane production may be much higher than was previously assumed.

  17. Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

    NASA Astrophysics Data System (ADS)

    Siegel, D. I.; Chanton, J. R.; Glaser, P. H.; Chasar, L. S.; Rosenberry, D. O.

    2001-12-01

    Raised bogs and municipal waste landfills harbor large populations of methanogens within their domed deposits of anoxic organic matter. Although the methane emissions from these sites have been estimated by various methods, limited data exist on the activity of the methanogens at depth. We therefore analyzed the stable isotopic signature of the pore waters in two raised bogs from northern Minnesota to identify depth intervals in the peat profile where methanogenic metabolism occurs. Methanogenesis enriched the deuterium (2H) content of the deep peat pore waters by as much as +11‰ (Vienna Standard Mean Sea Water), which compares to a much greater enrichment factor of +70‰ in leachate from New York City's Fresh Kills landfill. The bog pore waters were isotopically dated by tritium (3H) to be about 35 years old at 1.5 m depth, whereas the landfill leachate was estimated as ˜17 years old from Darcy flow calculations. According to an isotopic mass balance the observed deuterium enrichment indicates that about 1.2 g of CH4 m-3 d-1 were produced within the deeper peat, compared to about 2.8 g CH4 m-3 d-1 in the landfill. The values for methane production in the bog peat are substantially higher than the flux rates measured at the surface of the bogs or at the landfill, indicating that deeper methane production may be much higher than was previously assumed.

  18. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a human drug,...

  19. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a human drug,...

  20. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a human drug,...

  1. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a human drug,...

  2. 37 CFR 1.775 - Calculation of patent term extension for a human drug, antibiotic drug or human biological product.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... extension for a human drug, antibiotic drug or human biological product. 1.775 Section 1.775 Patents... Review § 1.775 Calculation of patent term extension for a human drug, antibiotic drug or human biological product. (a) If a determination is made pursuant to § 1.750 that a patent for a human drug,...

  3. Correlation of gene expression and protein production rate - a system wide study

    PubMed Central

    2011-01-01

    Background Growth rate is a major determinant of intracellular function. However its effects can only be properly dissected with technically demanding chemostat cultivations in which it can be controlled. Recent work on Saccharomyces cerevisiae chemostat cultivations provided the first analysis on genome wide effects of growth rate. In this work we study the filamentous fungus Trichoderma reesei (Hypocrea jecorina) that is an industrial protein production host known for its exceptional protein secretion capability. Interestingly, it exhibits a low growth rate protein production phenotype. Results We have used transcriptomics and proteomics to study the effect of growth rate and cell density on protein production in chemostat cultivations of T. reesei. Use of chemostat allowed control of growth rate and exact estimation of the extracellular specific protein production rate (SPPR). We find that major biosynthetic activities are all negatively correlated with SPPR. We also find that expression of many genes of secreted proteins and secondary metabolism, as well as various lineage specific, mostly unknown genes are positively correlated with SPPR. Finally, we enumerate possible regulators and regulatory mechanisms, arising from the data, for this response. Conclusions Based on these results it appears that in low growth rate protein production energy is very efficiently used primarly for protein production. Also, we propose that flux through early glycolysis or the TCA cycle is a more fundamental determining factor than growth rate for low growth rate protein production and we propose a novel eukaryotic response to this i.e. the lineage specific response (LSR). PMID:22185473

  4. Scaling in situ cosmogenic nuclide production rates using analytical approximations to atmospheric cosmic-ray fluxes

    NASA Astrophysics Data System (ADS)

    Lifton, Nathaniel; Sato, Tatsuhiko; Dunai, Tibor J.

    2014-01-01

    Several models have been proposed for scaling in situ cosmogenic nuclide production rates from the relatively few sites where they have been measured to other sites of interest. Two main types of models are recognized: (1) those based on data from nuclear disintegrations in photographic emulsions combined with various neutron detectors, and (2) those based largely on neutron monitor data. However, stubborn discrepancies between these model types have led to frequent confusion when calculating surface exposure ages from production rates derived from the models. To help resolve these discrepancies and identify the sources of potential biases in each model, we have developed a new scaling model based on analytical approximations to modeled fluxes of the main atmospheric cosmic-ray particles responsible for in situ cosmogenic nuclide production. Both the analytical formulations and the Monte Carlo model fluxes on which they are based agree well with measured atmospheric fluxes of neutrons, protons, and muons, indicating they can serve as a robust estimate of the atmospheric cosmic-ray flux based on first principles. We are also using updated records for quantifying temporal and spatial variability in geomagnetic and solar modulation effects on the fluxes. A key advantage of this new model (herein termed LSD) over previous Monte Carlo models of cosmogenic nuclide production is that it allows for faster estimation of scaling factors based on time-varying geomagnetic and solar inputs. Comparing scaling predictions derived from the LSD model with those of previously published models suggest potential sources of bias in the latter can be largely attributed to two factors: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. Given that the LSD model generates flux spectra for each cosmic-ray particle of interest, it is also relatively straightforward to generate nuclide-specific scaling

  5. EARLINET Single Calculus Chain - technical - Part 2: Calculation of optical products

    NASA Astrophysics Data System (ADS)

    Mattis, Ina; D'Amico, Giuseppe; Baars, Holger; Amodeo, Aldo; Madonna, Fabio; Iarlori, Marco

    2016-07-01

    In this paper we present the automated software tool ELDA (EARLINET Lidar Data Analyzer) for the retrieval of profiles of optical particle properties from lidar signals. This tool is one of the calculus modules of the EARLINET Single Calculus Chain (SCC) which allows for the analysis of the data of many different lidar systems of EARLINET in an automated, unsupervised way. ELDA delivers profiles of particle extinction coefficients from Raman signals as well as profiles of particle backscatter coefficients from combinations of Raman and elastic signals or from elastic signals only. Those analyses start from pre-processed signals which have already been corrected for background, range dependency and hardware specific effects. An expert group reviewed all algorithms and solutions for critical calculus subsystems which are used within EARLINET with respect to their applicability for automated retrievals. Those methods have been implemented in ELDA. Since the software was designed in a modular way, it is possible to add new or alternative methods in future. Most of the implemented algorithms are well known and well documented, but some methods have especially been developed for ELDA, e.g., automated vertical smoothing and temporal averaging or the handling of effective vertical resolution in the case of lidar ratio retrievals, or the merging of near-range and far-range products. The accuracy of the retrieved profiles was tested following the procedure of the EARLINET-ASOS algorithm inter-comparison exercise which is based on the analysis of synthetic signals. Mean deviations, mean relative deviations, and normalized root-mean-square deviations were calculated for all possible products and three height layers. In all cases, the deviations were clearly below the maximum allowed values according to the EARLINET quality requirements.

  6. Oxygen production rates for P/Halley over much of the 1985-1986 apparition

    NASA Technical Reports Server (NTRS)

    Spinrad, Hyron; Mccarthy, Patrick J.; Strauss, Michael A.

    1986-01-01

    Long slit CCD spectrophotometry of comet P/Halley in the visible region was used to measure the production rate of atomic oxygen during the 1985/86 apparition. The observations cover a large range of heliocentric distances, since the technique is applicable to apparently bright and faint comets. The cometary gas production rate for P/Halley increases rapidly with decreasing heliocentric distance toward perihelion and is systematicaly larger at a given heliocentric distance for the postperihelion observations. The average production rate for O1D on the day of the Giotto flyby is 4 times 10 to the 28th power atoms/sec giving an extrapolated total water production rate of 6 times 10 to the 29th power mols/sec. A method for comparing the absolute cometary gas production rates for different comets is discussed.

  7. Calculated Third Order Rate Constants for Interpreting the Mechanisms of Hydrolyses of Chloroformates, Carboxylic Acid Halides, Sulfonyl Chlorides and Phosphorochloridates

    PubMed Central

    Bentley, T. William

    2015-01-01

    Hydrolyses of acid derivatives (e.g., carboxylic acid chlorides and fluorides, fluoro- and chloroformates, sulfonyl chlorides, phosphorochloridates, anhydrides) exhibit pseudo-first order kinetics. Reaction mechanisms vary from those involving a cationic intermediate (SN1) to concerted SN2 processes, and further to third order reactions, in which one solvent molecule acts as the attacking nucleophile and a second molecule acts as a general base catalyst. A unified framework is discussed, in which there are two reaction channels—an SN1-SN2 spectrum and an SN2-SN3 spectrum. Third order rate constants (k3) are calculated for solvolytic reactions in a wide range of compositions of acetone-water mixtures, and are shown to be either approximately constant or correlated with the Grunwald-Winstein Y parameter. These data and kinetic solvent isotope effects, provide the experimental evidence for the SN2-SN3 spectrum (e.g., for chloro- and fluoroformates, chloroacetyl chloride, p-nitrobenzoyl p-toluenesulfonate, sulfonyl chlorides). Deviations from linearity lead to U- or V-shaped plots, which assist in the identification of the point at which the reaction channel changes from SN2-SN3 to SN1-SN2 (e.g., for benzoyl chloride). PMID:26006228

  8. Calculations with Spectroscopic Accuracy: Energies and Transition Rates in the Nitrogen Isoelectronic Sequence from Ar XII to Zn XXIV

    NASA Astrophysics Data System (ADS)

    Wang, K.; Si, R.; Dang, W.; Jönsson, P.; Guo, X. L.; Li, S.; Chen, Z. B.; Zhang, H.; Long, F. Y.; Liu, H. T.; Li, D. F.; Hutton, R.; Chen, C. Y.; Yan, J.

    2016-03-01

    Combined relativistic configuration interaction and many-body perturbation calculations are performed for the 359 fine-structure levels of the 2s2 2p3, 2 s2p4, 2p5, 2s2 2p2 3l, 2 s2p3 3l, 2p4 3l, and 2s2 2p2 4l configurations in N-like ions from Ar xii to Zn xxiv. Complete and consistent data sets of energies, wavelengths, radiative rates, oscillator strengths, and line strengths for all possible electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among the 359 levels are given for each ion. The present work significantly increases the amount of accurate data for ions in the nitrogen-like sequence, and the accuracy of the energy levels is high enough to enable the identification and interpretation of observed spectra involving the n = 3, 4 levels, for which experimental values are largely scarce. Meanwhile, the results should be of great help for modeling and diagnosing astrophysical and fusion plasmas.

  9. Viral abundance, production, decay rates and life strategies (lysogeny versus lysis) in Lake Bourget (France).

    PubMed

    Thomas, Rozenn; Berdjeb, Lyria; Sime-Ngando, Télesphore; Jacquet, Stéphan

    2011-03-01

    We have investigated the ecology of viruses in Lake Bourget (France) from January to August 2008. Data were analysed for viral and bacterial abundance and production, viral decay, frequency of lysogenic cells, the contribution of bacteriophages to prokaryotic mortality and their potential influence on nutrient dynamics. Analyses and experiments were conducted on samples from the epilimnion (2 m) and the hypolimnion (50 m), taken at the reference site of the lake. The abundance of virus-like particles (VLP) varied from 3.4 × 10⁷to 8.2 × 10⁷ VLP ml⁻¹; with the highest numbers and virus-to-bacterium ratio (VBR = 69) recorded in winter. Viral production varied from 3.2 × 10⁴ VLP ml⁻¹  h⁻¹ (July) to 2 × 10⁶ VLP ml⁻¹ h⁻¹ (February and April), and production was lower in the hypolimnion. Viral decay rate reached 0.12-0.15 day⁻¹, and this parameter varied greatly with sampling date and methodology (i.e. KCN versus filtration). Using transmission electron microscopy (TEM) analysis, viral lysis was responsible for 0% (January) to 71% (February) of bacterial mortality, while viral lysis varied between 0% (April) and 53% (January) per day when using a modified dilution approach. Calculated from viral production and burst size, the virus-induced bacterial mortality varied between 0% (January) and 68% (August). A weak relationship was found between the two first methods (TEM versus dilution approach). Interestingly, flow cytometry analysis performed on the dilution experiment samples revealed that the viral impact was mostly on high DNA content bacterial cells whereas grazing, varying between 8.3% (June) and 75.4% (April), was reflected in both HDNA and LDNA cells equally. The lysogenic fraction varied between 0% (spring/summer) and 62% (winter) of total bacterial abundance, and increased slightly with increasing amounts of mitomycin C added. High percentages of lysogenic cells were recorded when bacterial abundance and activity were the lowest

  10. Seasonal Changes in Mycosporine-Like Amino Acid Production Rate with Respect to Natural Phytoplankton Species Composition

    PubMed Central

    Ha, Sun-Yong; Lee, Yeonjung; Kim, Min-Seob; Kumar, K. Suresh; Shin, Kyung-Hoon

    2015-01-01

    After in situ incubation at the site for a year, phytoplanktons in surface water were exposed to natural light in temperate lakes (every month); thereafter, the net production rate of photoprotective compounds (mycosporine-like amino acids, MAAs) was calculated using 13C labeled tracer. This is the first report describing seasonal variation in the net production rate of individual MAAs in temperate lakes using a compound-specific stable isotope method. In the mid-latitude region of the Korean Peninsula, UV radiation (UVR) usually peaks from July to August. In Lake Paldang and Lake Cheongpyeong, diatoms dominated among the phytoplankton throughout the year. The relative abundance of Cyanophyceae (Anabaena spiroides) reached over 80% during July in Lake Cheongpyeong. Changes in phytoplankton abundance indicate that the phytoplankton community structure is influenced by seasonal changes in the net production rate and concentration of MAAs. Notably, particulate organic matter (POM) showed a remarkable change based on the UV intensity occurring during that period; this was because of the fact that cyanobacteria that are highly sensitive to UV irradiance dominated the community. POM cultured in Lake Paldang had the greatest shinorine (SH) production rate during October, i.e., 83.83 ± 10.47 fgC·L−1·h−1. The dominance of diatoms indicated that they had a long-term response to UVR. Evaluation of POM cultured in Lake Cheongpyeong revealed that there was an increase in the net MAA production in July (when UVR reached the maximum); a substantial amount of SH, i.e., 17.62 ± 18.34 fgC·L−1·h−1, was recorded during this period. Our results demonstrate that both the net production rate as well as the concentration of MAAs related to photoinduction depended on the phytoplankton community structure. In addition, seasonal changes in UVR also influenced the quantity and production of MAAs in phytoplanktons (especially Cyanophyceae). PMID:26561820

  11. Influence of nuclear basic data on the calculation of production cross sections of superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Bao, X. J.; Gao, Y.; Li, J. Q.; Zhang, H. F.

    2015-07-01

    The center of the predicted island of stability of superheavy nuclei (SHN) has not yet been observed experimentally. Many theories are being developed to understand the synthesizing mechanism of superheavy nuclei. However, all of them have to use some basic nuclear data. Three data tables, FRDM1995 [P. Möller et al., At. Data Nucl. Data Tables 59, 185 (1995), 10.1006/adnd.1995.1002], KTUY2005 [H. Koura et al., Prog. Theor. Phys. 113, 305 (2005), 10.1143/PTP.113.305], and WS2010 [Ning Wang et al., Phys. Rev. C 82, 044304 (2010), 10.1103/PhysRevC.82.044304], are used to investigate the SHN production. Based on the dinuclear system concept, the evaporation residue cross sections of SHN for Z =112-118 are calculated for the 48Ca -induced hot fusion reactions. It turns out that unlike the predictions made with the KTUY2005 and WS2010 data, the magic numbers Z =114 and N =184 predicted with the FRDM1995 data do not contradict the experimental data obtained so far.

  12. 78 FR 1277 - International Product Change-Global Expedited Package Services-Non-Published Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... Product Change--Global Expedited Package Services-- Non-Published Rates AGENCY: Postal Service TM . ACTION... Commission to add Global Expedited Package Services-- Non-Published Rates 4 (GEPS-NPR 4) to the Competitive... of the United States Postal Service to add Global Expedited Package Services-- Non-Published Rates...

  13. 76 FR 80987 - International Product Change-Global Expedited Package Services-Non-Published Rates

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ... Product Change--Global Expedited Package Services-- Non-Published Rates AGENCY: Postal Service TM . ACTION... Commission to add Global Expedited Package Services-- Non-Published Rates 3 (GEPS--NPR 3) to the Competitive... United States Postal Service to add Global Expedited Package Services--Non- Published Rates 3...

  14. Considerations in Dealing with Low Production Rates of Severely Retarded Workers.

    ERIC Educational Resources Information Center

    Horner, Robert H.; And Others

    Reported are four studies on methods to increase the production rates of severely and profoundly retarded adults in the sheltered workshop setting. It is explained that all four Ss had undergone intensive training on a complex task, were able to perform the task at a reasonably high rate, but did not usually maintain a high rate in the production…

  15. 30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Gas Production Requirements Production Rates § 250.1159 May the Regional Supervisor limit my well or... based on well tests and any limitations imposed by well and surface equipment, sand production... 30 Mineral Resources 2 2010-07-01 2010-07-01 false May the Regional Supervisor limit my well...

  16. A Step Toward Physics-Based Cosmogenic Nuclide Production Rates: Measurements of High-Energy Neutron Cross Sections

    NASA Astrophysics Data System (ADS)

    Caffee, M. W.; Welten, K. C.; Ninomiya, K.; Omoto, T.; Nakagaki, R.; Takahashi, N.; Kasamatsu, Y.; Shima, T.; Sekimoto, S.; Yashima, H.; Shibata, S.; Matsumura, H.; Bajo, K.; Nagao, K.; Satoh, D.; Iwamoto, Y.; Hagiwara, M.; Shinohara, A.; Imamura, M.; Nishiizumi, K.

    2010-12-01

    Cosmic-ray produced nuclides are found in terrestrial and extraterrestrial materials. In extra-terrestrial materials it is in many instances possible to find samples with exposure times much longer than a specifc radionuclide’s half-life so the production rate for a specific geometry can be determined from the saturation activity. For most terrestrial applications this condition is not met, so an exposure age can only be determined if the production rate is independently determined. For terrestrial applications these production rates are ascertained by using geologic calibration sites. These calibrations themselves are not without ambiguity at times. Physics-based production rates are an alternative means by which production rates can be determined. Monte Carlo neutron transport codes are the essential tool in model calculations of cosmogenic nuclide production rates in terrestrial and extraterrestrial materials. However, even when the fundamental physics of neutron transport within planetary materials (atmospheres and surface materials) is modeled properly, the reliability of the results is limited by the lack of measured cross sections. Indeed, at the present time, the lack of the excitation functions for nuclides produced by high-energy neutrons that dominate the production of cosmogenic nuclides, is the largest uncertainty in cosmogenic nuclide production rate models. To improve the accuracy of cosmogenic nuclide production rates we are performing measurements of the high-energy neutron excitation functions [1]. Target materials, representing compounds found in naturally occurring minerals, were exposed to quasi-monoenergetic neutrons at the Research Center for Nuclear Physics (RCNP), Osaka University. The neutrons are produced utilizing the reaction 7Li(p, n). The first two irradiations used 300 MeV and 392 MeV primary proton beams, yielding average neutron energies of 287 MeV and 370 MeV, respectively. After bombardment by neutrons, the short half

  17. 40 CFR Table I-15 to Subpart I of... - Default Emission Factors (1-Uij) for Gas Utilization Rates (Uij) and By-Product Formation Rates...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Default Emission Factors (1-Uij) for Gas Utilization Rates (Uij) and By-Product Formation Rates (Bijk) for MEMS Manufacturing for Use With...) for Gas Utilization Rates (Uij) and By-Product Formation Rates (Bijk) for MEMS Manufacturing for...

  18. Exact solutions for the entropy production rate of several irreversible processes.

    PubMed

    Ross, John; Vlad, Marcel O

    2005-11-24

    We investigate thermal conduction described by Newton's law of cooling and by Fourier's transport equation and chemical reactions based on mass action kinetics where we detail a simple example of a reaction mechanism with one intermediate. In these cases we derive exact expressions for the entropy production rate and its differential. We show that at a stationary state the entropy production rate is an extremum if and only if the stationary state is a state of thermodynamic equilibrium. These results are exact and independent of any expansions of the entropy production rate. In the case of thermal conduction we compare our exact approach with the conventional approach based on the expansion of the entropy production rate near equilibrium. If we expand the entropy production rate in a series and keep terms up to the third order in the deviation variables and then differentiate, we find out that the entropy production rate is not an extremum at a nonequilibrium steady state. If there is a strict proportionality between fluxes and forces, then the entropy production rate is an extremum at the stationary state even if the stationary state is far away from equilibrium.

  19. 42 CFR 484.220 - Calculation of the adjusted national prospective 60-day episode payment rate for case-mix and...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-day episode payment rate for case-mix and area wage levels. 484.220 Section 484.220 Public Health... Calculation of the adjusted national prospective 60-day episode payment rate for case-mix and area wage levels... case-mix using a case-mix index to explain the relative resource utilization of different patients....

  20. Titan-Like Exoplanets: Variations in Geometric Albedo and Effective Transit Height with Haze Production Rate

    NASA Technical Reports Server (NTRS)

    Checlair, Jade; McKay, Christopher P.; Imanaka, Hiroshi

    2016-01-01

    Extensive studies characterizing Titan present an opportunity to study the atmospheric properties of Titan-like exoplanets. Using an existing model of Titan's atmospheric haze, we computed geometric albedo spectra and effective transit height spectra for six values of the haze production rate (zero haze to twice present) over a wide range of wavelengths (0.2-2 microns). In the geometric albedo spectra, the slope in the UV-visible changes from blue to red when varying the haze production rate values from zero to twice the current Titan value. This spectral feature is the most effective way to characterize the haze production rates. Methane absorption bands in the visible-NIR compete with the absorbing haze, being more prominent for smaller haze production rates. The effective transit heights probe a region of the atmosphere where the haze and gas are optically thin and that is thus not effectively probed by the geometric albedo. The effective transit height decreases smoothly with increasing wavelength, from 376 km to 123 km at 0.2 and 2 microns, respectively. When decreasing the haze production rate, the methane absorption bands become more prominent, and the effective transit height decreases with a steeper slope with increasing wavelength. The slope of the geometric albedo in the UV-visible increases smoothly with increasing haze production rate, while the slope of the effective transit height spectra is not sensitive to the haze production rate other than showing a sharp rise when the haze production rate increases from zero. We conclude that geometric albedo spectra provide the most sensitive indicator of the haze production rate and the background Rayleigh gas. Our results suggest that important and complementary information can be obtained from the geometric albedo and motivates improvements in the technology for direct imaging of nearby exoplanets.