Chipping and grinding production rate calculator
Mathew. Smidt; Dana Mitchell
2014-01-01
The data for individual chipper and grinder production estimates were recorded with all the attributes available. If a study provided more than one production estimate and there was sufficient detail to describe each estimate, we entered multiple production estimates.
Production rate calculations for a secondary beam facility
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.
Calculation of in-target production rates for radioactive isotope beam production at TRIUMF
NASA Astrophysics Data System (ADS)
Garcia, Fatima; Andreoiu, Corina; Kunz, Peter; Laxdal, Aurelia
2016-09-01
Rare Isotope Beam (RIB) facilities around the world, such as TRIUMF, work towards development of new target materials to generate exotic species. Access to these rare radioactive isotopes is key for applications in nuclear medicine, astrophysics and fundamental nuclear science. To better understand production from these and other materials, we have built a computer simulation of the RIB targets used at the TRIUMF Isotope Separation and ACceleration (ISAC) facility, to support new target material development. Built at Simon Fraser University, the simulation runs in the GEANT4 nuclear transport toolkit, and can simulate the production rate of isotopes from a given set of beam and target characteristics. The simulation models the bombardment of a production target by an incident high-energy proton beam and calculates isotope in-target production rates different nuclear reactions. Results from the simulation will be presented, along with an evaluation of various nuclear reaction models and a experimentally determined RIB yields at the ISAC Yield Station.
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
... 19 Customs Duties 3 2010-04-01 2010-04-01 false Calculation of ad valorem subsidy rate and... Countervailable Subsidies § 351.525 Calculation of ad valorem subsidy rate and attribution of subsidy to a product. (a) Calculation of ad valorem subsidy rate. The Secretary will calculate an ad valorem subsidy...
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... Countervailable Subsidies § 351.525 Calculation of ad valorem subsidy rate and attribution of subsidy to a product. (a) Calculation of ad valorem subsidy rate. The Secretary will calculate an ad valorem subsidy...
Calculations of cosmogenic nuclide production rates in the Earth's atmosphere and their inventories
NASA Technical Reports Server (NTRS)
Obrien, K.
1986-01-01
The production rates of cosmogenic isotopes in the Earth's atmosphere and their resulting terrestrial abundances have been calculated, taking into account both geomagnetic and solar-modulatory effects. The local interstellar flux was assumed to be that of Garcia-Munoz, et al. Solar modulation was accounted for using the heliocentric potential model and expressed in terms of the Deep River neutron monitor count rates. The geomagnetic field was presented by vertical cutoffs calculated by Shea and Smart and the non-vertical cutoffs calculated using ANGRI. The local interstellar particle flux was first modulated using the heliocentric potential field. The modulated cosmic-ray fluxes reaching the earth's orbit then interacted with the geomagnetic field as though it were a high-pass filter. The interaction of the cosmic radiation with the Earth's atmosphere was calculated utilizing the Bolztmann transport equation. Spallation cross sections for isotope production were calculated using the formalism of Silberberg and Tsao and other cross sections were taken from standard sources. Inventories were calculated by accounting from the variation in solar modulation and geomagnetic field strength with time. Results for many isotope, including C-14, Be-7 and Be-10 are in generally good agreement with existing data. The C-14 inventory, for instance, amounts to 1.75/sq cm(e)/s, in excellent agreement with direct estimates.
Calculation of Neutron Production Rates and Spectra from Compounds of Actinides and Light Elements
NASA Astrophysics Data System (ADS)
Vlaskin, Gennady; Khomiakov, Yuriy
2017-09-01
The code NEDIS allows the calculation of neutron production rate and continuous energy spectra due to (α,n) reaction on Li, Be, B, C, O, F, Ne, Na Mg, Al, Si, P, S, Cl, Ar, K, and Ca. It accounts for anisotropic angular distribution of neutrons of (α,n) reaction in centre-of- mass system and dimensions of alpha emitting source material particles. Spontaneous fission spectra are calculated with evaluated half-life, spontaneous fission branching, ν- averaged per fission, and Watt spectrum parameters. The results of calculations by NEDIS can be used as input for Monte Carlo simulation for materials that will be used in radiation shielding and for underground neutron experiments
... workout Enter your age to find a target heart rate during exercise. You'll get the most out of your activities by staying within this range of heartbeats/minute. Please enter your age in years Calculate Your target heart rate is beats per minute. How to Check Your ...
The rating reliability calculator
Solomon, David J
2004-01-01
Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program. PMID:15117416
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.
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.
NASA Astrophysics Data System (ADS)
Chen, Jian; Dong, Tiekuang; Ren, Zhongzhou
2017-04-01
A physical model based on the open-source toolkit Geant4 for production rates of cosmogenic nuclei on the lunar surface is proposed and calibrated. The fluxes of proton and neutron beneath the lunar surface are obtained by simulating the physical processes between the cosmic-ray particles and the lunar surface material. By combining the experimental proton cross sections and the a posteriori neutron cross sections, we calculate the production rate depth profiles of long-lived nuclei (10Be, 14C, 26Al, 36Cl, and 53Mn). Through comparing experimental and theoretical data for these nuclei, we find that for all the selected nuclei, experimental and theoretical production rate depth profiles agree well with each other by introducing a single normalization factor. It means that the physical model based on Geant4 can also reproduce the depth profiles of cosmogenic nuclei, and that this model can be used by everyone worldwide. In addition, we predict the production rates of three stable nuclei (21Ne, 22Ne, and 38Ar).
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.
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.
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.
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.
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.
Calculation of molecular excitation rates
NASA Technical Reports Server (NTRS)
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
Comparison of calculations of fragment production
Canavan, G.H.
1998-01-01
This note compares estimates of fragment production rates in debris collisions through calculations performed with consistent debris distribution functions implicit in integrated collision frequencies provided by Attachment A. Differences between estimates of fragment production rates in space debris collisions are shown to be due primarily to different choices of the exponent in the fragment production function and the distinction between catastrophic and all collisions. Sensitivity to the fragment production parameter over the range of values consistent with experimental data is discussed.
Calculating transient rates from surveys
NASA Astrophysics Data System (ADS)
Carbone, D.; van der Horst, A. J.; Wijers, R. A. M. J.; Rowlinson, A.
2017-03-01
We have developed a method to determine the transient surface density and transient rate for any given survey, using Monte Carlo simulations. This method allows us to determine the transient rate as a function of both the flux and the duration of the transients in the whole flux-duration plane rather than one or a few points as currently available methods do. It is applicable to every survey strategy that is monitoring the same part of the sky, regardless the instrument or wavelength of the survey, or the target sources. We have simulated both top-hat and Fast Rise Exponential Decay light curves, highlighting how the shape of the light curve might affect the detectability of transients. Another application for this method is to estimate the number of transients of a given kind that are expected to be detected by a survey, provided that their rate is known.
ACTIVE: a program to calculate and plot reaction rates from ANISN calculated fluxes
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.
Noguchi, Kyotaro; Tanikawa, Toko; Inagaki, Yoshiyuki; Ishizuka, Shigehiro
2017-06-01
Several recent studies have used the net sheet method to estimate fine root production rates in forest ecosystems, wherein net sheets are inserted into the soil and fine roots growing through them are observed. Although this method has advantages in terms of its easy handling and low cost, there are uncertainties in the estimates per unit soil volume or unit stand area, because the net sheet is a two-dimensional material. Therefore, this study aimed to establish calculation procedures for estimating fine root production rates from two-dimensional fine root data on net sheets. This study was conducted in a hinoki cypress (Chamaecyparis obtusa (Sieb. & Zucc.) Endl.) stand in western Japan. We estimated fine root production rates in length and volume from the number (RN) and cross-sectional area (RCSA) densities, respectively, for fine roots crossing the net sheets, which were then converted to dry mass values. For these calculations, we used empirical regression equations or theoretical equations between the RN or RCSA densities on the vertical walls of soil pits and fine root densities in length or volume, respectively, in the soil, wherein the theoretical equations assumed random orientation of the growing fine roots. The estimates of mean fine root (diameter <1 mm) production rates were ∼80-100 g m-2 year-1 using the empirically obtained regression equations, whereas those from the theoretical equations were ∼40-50 g m-2 year-1. The difference in the estimates was attributed to larger slope values of the empirical regression equations than those of the theoretical equations, suggesting that fine root orientation was not random in our study site. In light of these results, we concluded that fine root production rates were successfully estimated from two-dimensional fine root data on the net sheets using these calculation procedures, with the empirical regression equations reflecting fine root orientation in the study site. © The Author 2017. Published by
Tank Z-361 dose rate calculations
Richard, R.F.
1998-09-30
Neutron and gamma ray dose rates were calculated above and around the 6-inch riser of tank Z-361 located at the Plutonium Finishing Plant. Dose rates were also determined off of one side of the tank. The largest dose rate 0.029 mrem/h was a gamma ray dose and occurred 76.2 cm (30 in.) directly above the open riser. All other dose rates were negligible. The ANSI/ANS 1991 flux to dose conversion factor for neutrons and photons were used in this analysis. Dose rates are reported in units of mrem/h with the calculated uncertainty shown within the parentheses.
Historical river flow rates for dose calculations
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.
Dose rate calculations for a reconnaissance vehicle.
Grindrod, L; Mackey, J; Salmon, M; Smith, C; Wall, S
2005-01-01
A Chemical Nuclear Reconnaissance System (CNRS) has been developed by the British Ministry of Defence to make chemical and radiation measurements on contaminated terrain using appropriate sensors and recording equipment installed in a land rover. A research programme is under way to develop and validate a predictive capability to calculate the build-up of contamination on the vehicle, radiation detector performance and dose rates to the occupants of the vehicle. This paper describes the geometric model of the vehicle and the methodology used for calculations of detector response. Calculated dose rates obtained using the MCBEND Monte Carlo radiation transport computer code in adjoint mode are presented. These address the transient response of the detectors as the vehicle passes through a contaminated area. Calculated dose rates were found to agree with the measured data to be within the experimental uncertainties, thus giving confidence in the shielding model of the vehicle and its application to other scenarios.
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.
CALCULATING ACCURATE SHUFFLER COUNT RATES WITH APPLICATIONS
P. M. RINARD
2001-05-01
Shufflers are used to assay uranium and other fissile elements in bulk and waste quantities. They normally require physical calibration standards to achieve the most-accurate results, but such standards are generally rare and expensive, so inappropriate standards are often used out of necessity. This paper reports on a new technique that has been developed to calculate accurate count rates, in effect simulating physical standards with rapid and inexpensive calculations. The technique has been benchmarked on existing oxide and metallic standards, used to study a variety of conditions for which standards do not exist, and applied to inventory items needing verification measurements even though appropriate physical standards do not exist.
Shuffler bias corrections using calculated count rates
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.
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%.
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.
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.
NASA Astrophysics Data System (ADS)
France, J. L.; King, M. D.; Lee-Taylor, J.; Beine, H. J.; Ianniello, A.; Domine, F.; MacArthur, A.
2011-12-01
Depth-integrated production rates of OH radicals and NO2 molecules from snowpacks in Ny-Ålesund, Svalbard, are calculated from fieldwork investigating the light penetration depth (e-folding depth) and nadir reflectivity of snowpacks during the unusually warm spring of 2006. Light penetration depths of 8.1, 11.3, 5.1, and 8.2 cm were measured for fresh, old, marine-influenced, and glacial snowpacks, respectively (wavelength 400 nm). Radiative-transfer calculations of the light penetration depths with reflectivity measurements produced scattering cross sections of 5.3, 9.5, 20, and 25.5 m2 kg-1 and absorption cross sections of 7.7, 1.4, 3.4, and 0.5 cm2 kg-1 for the fresh, old, marine-influenced, and glacial snowpacks, respectively (wavelength 400 nm). Photolysis rate coefficients, J, are presented as a function of snow depth and solar zenith angle for the four snowpacks for the photolysis of H2O2 and NO3-. Depth-integrated production rates of hydroxyl radicals are 1270, 2130, 950, and 1850 nmol m-2 h-1 (solar zenith angle of 60°) for fresh, old, marine-influenced, and glacial snowpacks, respectively. Depth-integrated production rates of NO2 are 32, 56, 11, and 22 nmol m-2 h-1 (solar zenith angle of 60°) for the fresh, old, marine-influenced, and glacial snowpacks, respectively. The uncertainty of repeated light penetration depth measurement was determined to be ˜20%, which propagates into a 20% error in depth-integrated production rates. A very simple steady state hydroxyl radical calculation demonstrates that a pseudo first-order loss rate of OH radicals of ˜102-104 s-1 is required in snowpack. The snowpacks around Ny-Ålesund are thick enough to be considered optically infinite.
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…
49 CFR 1141.1 - Procedures to calculate interest rates.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 8 2010-10-01 2010-10-01 false Procedures to calculate interest rates. 1141.1 Section 1141.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE PROCEDURES TO CALCULATE INTEREST RATES § 1141.1 Procedures to calculate interest rates. ...
49 CFR 1141.1 - Procedures to calculate interest rates.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 8 2011-10-01 2011-10-01 false Procedures to calculate interest rates. 1141.1 Section 1141.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE PROCEDURES TO CALCULATE INTEREST RATES § 1141.1 Procedures to calculate interest rates. ...
49 CFR 1141.1 - Procedures to calculate interest rates.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 8 2012-10-01 2012-10-01 false Procedures to calculate interest rates. 1141.1... TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE PROCEDURES TO CALCULATE INTEREST RATES § 1141.1 Procedures to calculate interest rates. (a) For purposes of complying with a Board decision in a...
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.
Calculating lunar retreat rates using tidal rhythmites
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).
Database crime to crime match rate calculation.
Buckleton, John; Bright, Jo-Anne; Walsh, Simon J
2009-06-01
Guidance exists on how to count matches between samples in a crime sample database but we are unable to locate a definition of how to estimate a match rate. We propose a method that does not proceed from the match counting definition but which has a strong logic.
Shielding calculations for a production target for secondary beams
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.
39 CFR 3010.23 - Calculation of percentage change in rates.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 39 Postal Service 1 2010-07-01 2010-07-01 false Calculation of percentage change in rates. 3010.23 Section 3010.23 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.23 Calculation of percentage change in rates. (a...
39 CFR 3010.26 - Calculation of unused rate adjustment authority.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 39 Postal Service 1 2010-07-01 2010-07-01 false Calculation of unused rate adjustment authority. 3010.26 Section 3010.26 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL REGULATION OF RATES FOR MARKET DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.26 Calculation of unused rate adjustment...
39 CFR 3010.23 - Calculation of percentage change in rates.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 39 Postal Service 1 2013-07-01 2013-07-01 false Calculation of percentage change in rates. 3010.23... DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.23 Calculation of percentage change in rates. (a... general applicability. Thus, seasonal or temporary rates, for example, shall be identified and treated as...
39 CFR 3010.23 - Calculation of percentage change in rates.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 39 Postal Service 1 2011-07-01 2011-07-01 false Calculation of percentage change in rates. 3010.23... DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.23 Calculation of percentage change in rates. (a... general applicability. Thus, seasonal or temporary rates, for example, shall be identified and treated as...
39 CFR 3010.23 - Calculation of percentage change in rates.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 39 Postal Service 1 2012-07-01 2012-07-01 false Calculation of percentage change in rates. 3010.23... DOMINANT PRODUCTS Rules for Applying the Price Cap § 3010.23 Calculation of percentage change in rates. (a... general applicability. Thus, seasonal or temporary rates, for example, shall be identified and treated as...
Problems in Calculating and Comparing Dropout Rates. ERS Research Digest.
ERIC Educational Resources Information Center
Ligon, Glynn; And Others
1990-01-01
This paper dramatizes the complexity and the problems involved in calculating the rates of student dropouts from school. To compare the dropout formulas used by various agencies, states, and local school systems, responses from a national survey are presented and used to calculate a range of dropout rates for the Austin (Texas) public schools. By…
40 CFR 1036.530 - Calculating greenhouse gas emission rates.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Calculating greenhouse gas emission rates. 1036.530 Section 1036.530 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Procedures § 1036.530 Calculating greenhouse gas emission rates. This section describes how to...
40 CFR 1036.530 - Calculating greenhouse gas emission rates.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Calculating greenhouse gas emission rates. 1036.530 Section 1036.530 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Procedures § 1036.530 Calculating greenhouse gas emission rates. This section describes how to...
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 rates. 1036.530 Section 1036.530 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Procedures § 1036.530 Calculating greenhouse gas emission rates. This section describes how to...
Updates to In-Line Calculation of Photolysis Rates
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 ...
Updates to In-Line Calculation of Photolysis Rates
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 ...
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…
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…
Experiences with leak rate calculations methods for LBB application
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.
Correlated uncertainties in Monte Carlo reaction rate calculations
NASA Astrophysics Data System (ADS)
Longland, Richard
2017-07-01
Context. Monte Carlo methods have enabled nuclear reaction rates from uncertain inputs to be presented in a statistically meaningful manner. However, these uncertainties are currently computed assuming no correlations between the physical quantities that enter those calculations. This is not always an appropriate assumption. Astrophysically important reactions are often dominated by resonances, whose properties are normalized to a well-known reference resonance. This insight provides a basis from which to develop a flexible framework for including correlations in Monte Carlo reaction rate calculations. Aims: The aim of this work is to develop and test a method for including correlations in Monte Carlo reaction rate calculations when the input has been normalized to a common reference. Methods: A mathematical framework is developed for including correlations between input parameters in Monte Carlo reaction rate calculations. The magnitude of those correlations is calculated from the uncertainties typically reported in experimental papers, where full correlation information is not available. The method is applied to four illustrative examples: a fictional 3-resonance reaction, 27Al(p, γ)28Si, 23Na(p, α)20Ne, and 23Na(α, p)26Mg. Results: Reaction rates at low temperatures that are dominated by a few isolated resonances are found to minimally impacted by correlation effects. However, reaction rates determined from many overlapping resonances can be significantly affected. Uncertainties in the 23Na(α, p)26Mg reaction, for example, increase by up to a factor of 5. This highlights the need to take correlation effects into account in reaction rate calculations, and provides insight into which cases are expected to be most affected by them. The impact of correlation effects on nucleosynthesis is also investigated.
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.
Efficient calculation of atomic rate coefficients in dense plasmas
NASA Astrophysics Data System (ADS)
Aslanyan, Valentin; Tallents, Greg J.
2017-03-01
Modelling electron statistics in a cold, dense plasma by the Fermi-Dirac distribution leads to complications in the calculations of atomic rate coefficients. The Pauli exclusion principle slows down the rate of collisions as electrons must find unoccupied quantum states and adds a further computational cost. Methods to calculate these coefficients by direct numerical integration with a high degree of parallelism are presented. This degree of optimization allows the effects of degeneracy to be incorporated into a time-dependent collisional-radiative model. Example results from such a model are presented.
Pocket calculator for local fire-danger ratings
Richard J. Barney; William C. Fischer
1967-01-01
In 1964, Stockstad and Barney published tables that provided conversion factors for calculating local fire danger in the Intermountain area according to fuel types, locations, steepness of terrain, aspects, and times of day. These tables were based on the National Fire-Danger Rating System published earlier that year. This system was adopted for operational use in...
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.
Methods for calculating SEU rates for bipolar and NMOS circuits
NASA Astrophysics Data System (ADS)
McNulty, P. J.; Abdel-Kader, W. G.; Bisgrove, J. M.
1985-12-01
Computer codes developed at Clarkson for simulating charge generation by proton-induced nuclear reactions in well-defined silicon microstructures can be used to calculate SEU rates for specific devices when the critical charge and the dimensions of all SEU sensitive junctions on the device are known, provided one can estimate the contribution from externally-generated charge which enters the sensitive junction by drift and diffusion. Calculations for two important bipolar devices, the AMD 2901B bit slice and the Fairchild 93L422 RAM, for which the dimensions of the sensitive volumes were estimated from available heavy-ion test data, have been found to be in agreement with experimental data. Circuit data for the Intel 2164A, an alpha sensitive dRAM, was provided by the manufacturer. Calculations based on crude assumptions regarding which nuclear recoils and which alphas trigger upsets in the 2164A were found to agree with experimental data.
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.
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.
Uncertainties in the calculation of solar-neutrino capture rates
Filippone, B.W.
1981-01-01
A detailed estimate is presented of the possible uncertainty range for the neutrino flux from a standard solar model. Using present estimated errors in the key input parameters, detailed solar models are calculated to give an uncertainty in the theoretical nu/sub e/ capture rate in both the on-going /sup 37/Cl experiment and the proposed experiment using /sup 71/Ga. The uncertainty in capture rate is investigated by considering individual parameter variations about a mean model, by simultaneously varying several key parameters to yield upper and lower limits, and by a Monte Carlo method.
Calculating Sputter Rate Angular Dependence Using Optical Profilometry (Preprint)
2007-07-26
This work attempts to determine angular dependence curves for sputter rates of a material based on a single experimental measurement. An aluminum...angular dependence curve to match the given erosion profile. The calculated profile matched well with the experimental profile; however, neither matched...the optimization routine, the angular dependence curve was input to the COLISEUM plasma modeling code, which generated the same erosion profile as the experimental data.
NAC-1 cask dose rate calculations for LWR spent fuel
CARLSON, A.B.
1999-02-24
A Nuclear Assurance Corporation nuclear fuel transport cask, NAC-1, is being considered as a transport and storage option for spent nuclear fuel located in the B-Cell of the 324 Building. The loaded casks will be shipped to the 200 East Area Interim Storage Area for dry interim storage. Several calculations were performed to assess the photon and neutron dose rates. This report describes the analytical methods, models, and results of this investigation.
Calculating the Annihilation Rate of Weakly Interacting Massive Particles
NASA Astrophysics Data System (ADS)
Baumgart, Matthew; Rothstein, Ira Z.; Vaidya, Varun
2015-05-01
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.
[Calculating the intrinsic growth rate: comparison of definition and model].
Voronov, D A
2005-01-01
It was shown that well known equation r = ln[N(t2)/N(t1)]/(t2 - t1) is the definition of the average value of intrinsic growth rate of population r within any given interval of time t2-t1 and changing arbitrarity its numbers N(t). The common opinion considering the equation as suitable only for exponentially growing population was found to be incorrect. The fundamentally different approach is based on the calculation of r within the framework of demographic model, realized as Euler - Lotka equation or population projection matrices. However this model requires simultaneous realization of several assumptions improbable for natural populations: exponential change in population size, stable age structure and maintaining constant age-dependent birth and death rates. The calculation of r by definition requires the data on the dynamics of population numbers, whereas calculation on the basis of the model requires the demographic tables of birth and death rate, but not the population numbers. With the example of American ginseng it was shown that evalution of r by definition and model approaches could produce opposite results.
7 CFR 760.811 - Rates and yields; calculating payments.
Code of Federal Regulations, 2010 CFR
2010-01-01
... average market price times 42 percent, times the loss of production which exceeds 35 percent of the... percent of the average market price. (c) Separate payment rates and yields for the same crop may be... value based on a distinct and separate end use of the crop. Despite potential differences in yield or...
Divided Saddle Theory: A New Idea for Rate Constant Calculation.
Daru, János; Stirling, András
2014-03-11
We present a theory of rare events and derive an algorithm to obtain rates from postprocessing the numerical data of a free energy calculation and the corresponding committor analysis. The formalism is based on the division of the saddle region of the free energy profile of the rare event into two adjacent segments called saddle domains. The method is built on sampling the dynamics within these regions: auxiliary rate constants are defined for the saddle domains and the absolute forward and backward rates are obtained by proper reweighting. We call our approach divided saddle theory (DST). An important advantage of our approach is that it requires only standard computational techniques which are available in most molecular dynamics codes. We demonstrate the potential of DST numerically on two examples: rearrangement of alanine-dipeptide (CH3CO-Ala-NHCH3) conformers and the intramolecular Cope reaction of the fluxional barbaralane molecule.
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.
User's guide to SERICPAC: A computer program for calculating electric-utility avoided costs rates
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.
Benchmark calculations for FFTF Inner radial shield damage rates
Lu, A.H.; Schwarz, R.A.; Simons, R.L.
1991-12-01
A comparison of the damage rates calculated by Monte Carlo Neutron Photon (MCNP), with values based on a FERRET-adjusted diffusion theory flux, was made for 22 dosimeter locations in the Fast Flux Test Facility (FFTF). The C/E values in the fueled region for characterizer assemblies in core locations 2101, 2402, 3404, 2503, 2603 and in the axial reflector of assembly 2101 are within 10% of unity, indicating agreement within the combined calculated and adjusted uncertainties. The comparison also shows good agreement within 20% of unity in most of the axial zones of radial reflectors in rows 7, 8, and 9, their deviation either within, or slightly outside, the combined one-sigma uncertainty. There are three relatively large C/E deviations, ranging from 30% to 45% of unity, in the lower reflector block of row 9 and the upper shield regions of rows 7 and 8. The possible reasons for the large C/E are explained.
Reference calculations for subthreshold Ξ production
NASA Astrophysics Data System (ADS)
Tomášik, Boris; Kolomeitsev, Evgeni E.
2016-01-01
We present a minimal statistical model designed for the description of rare- hadron multiplicities in nucleus-nucleus collisions at energies below the threshold of the particle production in binary elementary collisions. Differences to more conventional canonical statistical model are explained. The minimal statistical model is applied to the description of multiplicity ratios involving Ξ hyperons, which are measured by the HADES collaboration at GSI-SIS. It is argued that the HADES data cannot be reproduced by the model based on the statistical equilibrium and the strangeness conservation. The data remain underpredicted even when inmedium potentials acting on hadrons are taken into account. This hints to non-equilibrium production of the Ξ hyperons and their continuous freeze-out.
Calculations of bottom quark production at hadron colliders
Kuebel, D.
1991-06-29
This thesis studies Monte Carlo simulations of QCD heavy flavor production processes (p$\\bar{p}$ → Q($\\bar{Q}$)X) at hadron colliders. ISAJET bottom quark cross-sections are compared to the O(α$3\\atop{s}$) 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.
Calculations of bottom quark production at hadron colliders
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.
Calculate bit error rate for digital radio signal transmission
NASA Astrophysics Data System (ADS)
Sandberg, Jorgen
1987-06-01
A method for estimating symbol error rate caused by imperfect transmission channels is proposed. The method relates the symbol error rate to peak-to-peak amplitude and phase ripple, maximum gain slope, and maximum group delay distortion. The performance degradation of QPSK, offset QPSK (OQPSK), M-ary PSK (MSK) signals transmitted over a wideband channel, exhibiting either sinusoidal amplitude or phase ripples are evaluated using the proposed method. The transmission channel model, which is a single filter with transfer characteristics, for modeling the frequency of response of a system is described. Consideration is given to signal detection and system degradation. The calculations reveal that the QPSK modulated carrier degrades less then the OQPSK and MSK carriers for peak-to-peak amplitude ripple values less than 6 dB and peak-to-peak phase ripple values less than 45 deg.
NASA Technical Reports Server (NTRS)
Toon, Owen B.; Mckay, C. P.; Ackerman, T. P.; Santhanam, K.
1989-01-01
The solution of the generalized two-stream approximation for radiative transfer in homogeneous multiple scattering atmospheres is extended to vertically inhomogeneous atmospheres in a manner which is numerically stable and computationally efficient. It is shown that solar energy deposition rates, photolysis rates, and infrared cooling rates all may be calculated with the simple modifications of a single algorithm. The accuracy of the algorithm is generally better than 10 percent, so that other uncertainties, such as in absorption coefficients, may often dominate the error in calculation of the quantities of interest to atmospheric studies.
PFP vertical calciner shield wall dose rate calculations using MCNP
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.
Cubic spline functions and polynomials for calculation of absorption rate.
Popović, J
1998-01-01
A model-independent method for calculation of the absorption rate based on an exact mathematical solution to the deconvolution problem of systems with linear pharmacokinetics and a polyexponential impulse responses has been examined. Theoretical analysis shows how a noninteracting primary input can be precisely evaluated when data on blood levels from a known source such as an i.v. bolus or zero-order infusion are available. This work compares the use of a Lagrange 3rd degree polynomial with that of a cubic spline function (special 3rd degree polynomial) for calculation of the absorption rate. The method is compared to another using simulated data (12 data points) containing various degrees of random noise.The accuracy of the methods is determined by how well the estimates represent the true values. It was found that the accuracy of the two methods was not significantly different, and that it was of the same order of magnitude as the noise level of the data.
PRESTO: online calculation of carbon in harvested wood products
Coeli M. Hoover; Sarah J. Beukema; Donald C.E. Robinson; Katherine M. Kellock; Diana A. Abraham
2014-01-01
Carbon stored in harvested wood products is recognized under international carbon accounting protocols, and some crediting systems may permit the inclusion of harvested wood products when calculating carbon sequestration. For managers and landowners, however, estimating carbon stored in harvested wood products may be difficult. PRESTO (PRoduct EStimation Tool Online)...
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.
Relativistic collision rate calculations for electron-air interactions
Graham, G.; Roussel-Dupre, R.
1993-12-01
The most recent data available on differential cross sections for electron-air interactions are used to calculate the avalanche, momentum transfer, and energy loss rates that enter into the fluid equations. Data for the important elastic, inelastic, and ionizing processes are generally available out to electron energies of 1--10 keV. Prescriptions for extending these cross sections to the relativistic regime are presented. The angular dependence of the cross sections is included where data are available as is the doubly differential cross section for ionizing collisions. The collision rates are computed by taking moments of the Boltzmann collision integrals with the assumption that the electron momentum distribution function is given by the Juettner distribution function which satisfies the relativistic H- theorem and which reduces to the familiar Maxwellian velocity distribution in the nonrelativistic regime. The distribution function is parameterized in terms of the electron density, mean momentum, and thermal energy and the rates are therefore computed on a two dimensional grid as a function of mean kinetic energy and thermal energy.
Relativistic collision rate calculations for electron-air interactions
Graham, G.; Roussel-Dupre, R.
1992-12-16
The most recent data available on differential cross sections for electron-air interactions are used to calculate the avalanche, momentum transfer, and energy loss rates that enter into the fluid equations. Data for the important elastic, inelastic, and ionizing processes are generally available out to electron energies of 1--10 kev. Prescriptions for extending these cross sections to the relativistic regime are presented. The angular dependence of the cross sections is included where data is available as is the doubly differential cross section for ionizing collisions. The collision rates are computed by taking moments of the Boltzmann collision integrals with the assumption that the electron momentum distribution function is given by the Juettner distribution function which satisfies the relativistic H- theorem and which reduces to the familiar Maxwellian velocity distribution in the nonrelativistic regime. The distribution function is parameterized in terms of the electron density, mean momentum, and thermal energy and the rates are therefore computed on a two-dimensional grid as a function of mean kinetic energy and thermal energy.
30 CFR 250.1632 - Production rates.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 30 Mineral Resources 2 2011-07-01 2011-07-01 false Production rates. 250.1632 Section 250.1632 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE... § 250.1632 Production rates. Each sulphur deposit shall be produced at rates that will provide...
Improving convergence rates for low pressure material processing calculations
Moen, C.D.
1996-12-01
An enhanced solution strategy for the SIMPLER algorithm is presented for low pressure heat and mass transport calculations with applications in material processing. The accurate solution of highly diffusive flows requires an inflow boundary condition that preserves chemical species mass fluxes. The flux-preserving inflow boundary condition contains a scaling problem that causes the species equations to converge very slowly when using the standard SIMPLER algorithm. A gradient algorithm, coupled to a line-relaxation method, accelerates the convergence of the linear problem. Reformulation of the pressure-correction boundary conditions ensures that continuity is preserved in each finite volume at each iteration. The boundary condition scaling problem is demonstrated with a simple linear model problem. The enhanced solution strategy is implemented in a baseline computer code that is used to solve the multicomponent Navier-Stokes equations on a generalized, multiple-block grid system. Convergence rate acceleration factors of up to 100 are demonstrated for several material processing example problems.
Precision decay rate calculations in quantum field theory
NASA Astrophysics Data System (ADS)
Andreassen, Anders; Farhi, David; Frost, William; Schwartz, Matthew D.
2017-04-01
Tunneling in quantum field theory is worth understanding properly, not least because it controls the long-term fate of our Universe. There are, however, a number of features of tunneling rate calculations which lack a desirable transparency, such as the necessity of analytic continuation, the appropriateness of using an effective instead of classical potential, and the sensitivity to short-distance physics. This paper attempts to review in pedagogical detail the physical origin of tunneling and its connection to the path integral. Both the traditional potential-deformation method and a recent, more direct, propagator-based method are discussed. Some new insights from using approximate semiclassical solutions are presented. In addition, we explore the sensitivity of the lifetime of our Universe to short-distance physics, such as quantum gravity, emphasizing a number of important subtleties.
A model to calculate the induced dose rate around an 18 MV ELEKTA linear accelerator.
Perrin, Bruce; Walker, Anne; Mackay, Ranald
2003-03-07
The dose rate due to activity induced by (gamma, n) reactions around an ELEKTA Precise accelerator running at 18 MV is reported. A model to calculate the induced dose rate for a variety of working practices has been derived and compared to the measured values. From this model, the dose received by the staff using the machine can be estimated. From measured dose rates at the face of the linear accelerator for a 10 x 10 cm2 jaw setting at 18 MV an activation coefficient per MU was derived for each of the major activation products. The relative dose rates at points around the linac head, for different energy and jaw settings, were measured. Dose rates adjacent to the patient support system and portal imager were also measured. A model to calculate the dose rate at these points was derived, and compared to those measured over a typical working week. The model was then used to estimate the maximum dose to therapists for the current working schedule on this machine. Calculated dose rates at the linac face agreed to within +/- 12% of those measured over a week, with a typical dose rate of 4.5 microSv h(-1) 2 min after the beam has stopped. The estimated maximum annual whole body dose for a treatment therapist, with the machine treating at only 18 MV, for 60000 MUs per week was 2.5 mSv. This compares well with value of 2.9 mSv published for a Clinac 21EX. A model has been derived to calculate the dose from the four dominant activation products of an ELEKTA Precise 18 MV linear accelerator. This model is a useful tool to calculate the induced dose rate around the treatment head. The model can be used to estimate the dose to the staff for typical working patterns.
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.
Radionuclide production calculations: A GUI to determine irradiation conditions
NASA Astrophysics Data System (ADS)
Ferguson, S.; Riauka, T.; Jans, H.; Gagnon, K.
2017-05-01
There is a wide diversity of production methods for radionuclides. With these, intensive calculations are often required to characterize the different radionuclide production strategies and to determine optimal irradiation parameters. These calculations are essential for predicting the yield and radionuclidic purity of the resulting product. In this work, a graphical user interface (GUI) has been built in Matlab® to facilitate these production calculations and compare production methods. The user is able to import cross-sections, define target compositions and outline irradiation conditions for calculating yields. This GUI facilitates the process of varying irradiation parameters and allows the user to determine the yield of radionuclides as a function of energy and time.
Robust Biased Brownian Dynamics for Rate Constant Calculation
Zou, Gang; Skeel, Robert D.
2003-01-01
A reaction probability is required to calculate the rate constant of a diffusion-dominated reaction. Due to the complicated geometry and potentially high dimension of the reaction probability problem, it is usually solved by a Brownian dynamics simulation, also known as a random walk or path integral method, instead of solving the equivalent partial differential equation by a discretization method. Building on earlier work, this article completes the development of a robust importance sampling algorithm for Brownian dynamics—i.e., biased Brownian dynamics with weight control—to overcome the high energy and entropy barriers in biomolecular association reactions. The biased Brownian dynamics steers sampling by a bias force, and the weight control algorithm controls sampling by a target weight. This algorithm is optimal if the bias force and the target weight are constructed from the solution of the reaction probability problem. In reality, an approximate reaction probability has to be used to construct the bias force and the target weight. Thus, the performance of the algorithm depends on the quality of the approximation. Given here is a method to calculate a good approximation, which is based on the selection of a reaction coordinate and the variational formulation of the reaction probability problem. The numerically approximated reaction probability is shown by computer experiments to give a factor-of-two speedup over the use of a purely heuristic approximation. Also, the fully developed method is compared to unbiased Brownian dynamics. The tests for human superoxide dismutase, Escherichia coli superoxide dismutase, and antisweetener antibody NC6.8, show speedups of 17, 35, and 39, respectively. The test for reactions between two model proteins with orientations shows speedups of 2578 for one set of configurations and 3341 for another set of configurations. PMID:14507681
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
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...
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.
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.
Calculation of Reactive-evaporation Rates of Chromia
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.
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
42 CFR 413.312 - Methodology for calculating rates.
Code of Federal Regulations, 2010 CFR
2010-10-01
... SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Prospectively Determined Payment Rates for Low-Volume Skilled Nursing Facilities, for Cost Reporting Periods Beginning...
42 CFR 413.312 - Methodology for calculating rates.
Code of Federal Regulations, 2012 CFR
2012-10-01
... SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Prospectively Determined Payment Rates for Low-Volume Skilled Nursing Facilities, for Cost Reporting Periods...
Calculating coherent pair production with Monte Carlo methods
Bottcher, C.; Strayer, M.R.
1989-01-01
We discuss calculations of the coherent electromagnetic pair production in ultra-relativistic hadron collisions. This type of production, in lowest order, is obtained from three diagrams which contain two virtual photons. We discuss simple Monte Carlo methods for evaluating these classes of diagrams without recourse to involved algebraic reduction schemes. 19 refs., 11 figs.
Ultrasonic energy in liposome production: process modelling and size calculation.
Barba, A A; Bochicchio, S; Lamberti, G; Dalmoro, A
2014-04-21
The use of liposomes in several fields of biotechnology, as well as in pharmaceutical and food sciences is continuously increasing. Liposomes can be used as carriers for drugs and other active molecules. Among other characteristics, one of the main features relevant to their target applications is the liposome size. The size of liposomes, which is determined during the production process, decreases due to the addition of energy. The energy is used to break the lipid bilayer into smaller pieces, then these pieces close themselves in spherical structures. In this work, the mechanisms of rupture of the lipid bilayer and the formation of spheres were modelled, accounting for how the energy, supplied by ultrasonic radiation, is stored within the layers, as the elastic energy due to the curvature and as the tension energy due to the edge, and to account for the kinetics of the bending phenomenon. An algorithm to solve the model equations was designed and the relative calculation code was written. A dedicated preparation protocol, which involves active periods during which the energy is supplied and passive periods during which the energy supply is set to zero, was defined and applied. The model predictions compare well with the experimental results, by using the energy supply rate and the time constant as fitting parameters. Working with liposomes of different sizes as the starting point of the experiments, the key parameter is the ratio between the energy supply rate and the initial surface area.
Code System to Calculate Integral Parameters with Reaction Rates from WIMS Output.
LESZCZYNSKI, FRANCISCO
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.
Krypton Production Cross Sections and Production Rates in Simulation Experiments
NASA Astrophysics Data System (ADS)
Gilabert, E.; Lavielle, B.; Schiekel, Th.; Herpers, U.; Neumann, S.; Michel, R.
1995-09-01
The stacked-foil technique was used to measured proton induced excitation functions from Sr targets (SrF2). The irradiations were performed at the Laboratoire National Saturne in Saclay (F), the Svedberg Laboratory in Uppsala (S) and the Paul Scherrer Institute in Villigen (CH) with primary energies from 45 to 400 MeV. After gamma-spectrometric measurement of short and medium-lived radionuclides and after sufficient cooling, stable and long lived Kr isotopes were measured at Centre Etude Nucleaire in Bordeaux (F). Deduced cross sections were corrected for the production of secondary protons and neutrons by a method developed by Lupke[1]. There are no literature data which can be compared with the cross sections from this work. Theoretical calculations of cross sections were performed using two approaches. The first one was using the hybrid model of preequilibrium reactions with the code AREL[2]. The second was using the Intra-Nuclear-Cascade/Evaporation model in the form of the High Energy Transport Code (HETC)[3]. This study shows that for energies above 200 MeV, the spallation model is better suited to explain the nuclear reactions whereas the preequilibrium model leads to underestimation of the experimental data. For energies above 200 MeV, HETC should be preferred to AREL calculations. In physical models describing galactic cosmic ray (GCR) interactions with matter [4], cross sections of both, proton and neutron-induced reactions, are important parameters. Using the measured cross sections for proton-induced reactions from this work and the experimental Kr depth profiles obtained from Sr targets in the LNS172 simulation experiment [5], we established a set of excitation functions for neutron-induced reactions, which now excellently describes the production rate depth profiles from the simulation experiment. Before measuring experimental cross sections for Kr from Sr, the theoretical depth profiles calculated with pure theoretical excitation functions showed
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... by The Wall Street Journal in effect on the day when the unlawful charge is paid. The interest rate in complaint proceedings shall be updated whenever The Wall Street Journal publishes a change to...
49 CFR 1141.1 - Procedures to calculate interest rates.
Code of Federal Regulations, 2013 CFR
2013-10-01
.... Prime Rate as published by The Wall Street Journal. The rate levels will be determined as follows: (1... by The Wall Street Journal in effect on the day when the unlawful charge is paid. The interest rate in complaint proceedings shall be updated whenever The Wall Street Journal publishes a change to...
Effect of seeding rate on organic production
USDA-ARS?s Scientific Manuscript database
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...
30 CFR 250.1632 - Production rates.
Code of Federal Regulations, 2013 CFR
2013-07-01
... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632 Production rates. Each sulphur deposit shall be produced at rates that will provide economic development and depletion of the deposit in a manner that would maximize the ultimate recovery of sulphur without resulting...
30 CFR 250.1632 - Production rates.
Code of Federal Regulations, 2014 CFR
2014-07-01
... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632 Production rates. Each sulphur deposit shall be produced at rates that will provide economic development and depletion of the deposit in a manner that would maximize the ultimate recovery of sulphur without resulting...
30 CFR 250.1632 - Production rates.
Code of Federal Regulations, 2012 CFR
2012-07-01
... AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Sulphur Operations § 250.1632 Production rates. Each sulphur deposit shall be produced at rates that will provide economic development and depletion of the deposit in a manner that would maximize the ultimate recovery of sulphur without resulting...
Comment on mesic-atom Auger-rate calculation
NASA Astrophysics Data System (ADS)
Altman, A.; Fried, Z.
1983-07-01
Auger rates for a mesic atom consisting of a lithium nucleus and two electrons are presented. It is shown that the results are sensitive to the screening of the initial and final state of the ejected electron by the spectator electron. These results are compared to transition rates one would obtain by following the procedure used by Burbridge and de Borde, which neglect screening of one electron by the others. Our results show a 40% reduction in transition rates.
Calculation of kinetic rate constants from thermodynamic data
NASA Technical Reports Server (NTRS)
Marek, C. John
1995-01-01
A new scheme for relating the absolute value for the kinetic rate constant k to the thermodynamic constant Kp is developed for gases. In this report the forward and reverse rate constants are individually related to the thermodynamic data. The kinetic rate constants computed from thermodynamics compare well with the current kinetic rate constants. This method is self consistent and does not have extensive rules. It is first demonstrated and calibrated by computing the HBr reaction from H2 and Br2. This method then is used on other reactions.
Arbib, Zouhayr; de Godos Crespo, Ignacio; Corona, Enrique Lara; Rogalla, Frank
2017-06-01
Microalgae culture in high rate algae ponds (HRAP) is an environmentally friendly technology for wastewater treatment. However, for the implementation of these systems, a better understanding of the oxygenation potential and the influence of climate conditions is required. In this work, the rates of oxygen production, consumption, and exchange with the atmosphere were calculated under varying conditions of solar irradiance and dilution rate during six months of operation in a real scale unit. This analysis allowed determining the biological response of these dynamic systems. The rates of oxygen consumption measured were considerably higher than the values calculated based on the organic loading rate. The response to light intensity in terms of oxygen production in the bioreactor was described with one of the models proposed for microalgae culture in dense concentrations. This model is based on the availability of light inside the culture and the specific response of microalgae to this parameter. The specific response to solar radiation intensity showed a reasonable stability in spite of the fluctuations due to meteorological conditions. The methodology developed is a useful tool for optimization and prediction of the performance of these systems.
Evaluating ventilation rates based on new heat and moisture production data for swine production
USDA-ARS?s Scientific Manuscript database
Heat and moisture production (HMP) rates of animals are used for calculation of ventilation rate (VR) in animal housing. New swine HMP data revealed considerable differences from previously reported data. This project determined new design VR and evaluated differences from previously recommended VRs...
Production rates of cosmogenic nuclides in stony meteorites
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.
Hicks, H.G.
1981-03-03
The results of computer calculations of the nuclide composition and associated external gamma-ray exposure rates for fallout from the HARRY, SMOKY, and ANNIE events are documented. The fission product distribution is calculated for each event with the appropriate neutron spectrum and the fractions of fissions due to each fissionable material. Also calculated are the total number of microcuries per square meter and the gamma-ray exposure rates (mR/h, 1 meter above ground level) for the 152 fission products and 25 neutron-induced nuclides. The normalized data are presented in 9 Appendices. (DLS)
NASA Astrophysics Data System (ADS)
Kaiser, J.
2011-07-01
Oxygen triple isotope measurements can be used to calculate aquatic gross oxygen production rates. Past studies have emphasised the appropriate definition of the 17O excess and often used an approximation to derive production rates from the 17O excess. Here, I show that the calculation can be phrased more consistently and without any approximations using the relative 17O/16O and 18O/16O isotope ratio differences (delta values) directly. I call this the "dual delta method". The 17O excess is merely a mathematical construct and the derived production rate is independent of its definition, provided all calculations are performed with a consistent definition. I focus on the mixed layer, but also show how time series of triple isotope measurements below the mixed layer can be used to derive gross production. In the calculation of mixed layer productivity, I explicitly include isotopic fractionation during gas invasion and evasion, which requires the oxygen supersaturation s to be measured as well. I also suggest how bubble injection could be considered in the same mathematical framework. I distinguish between concentration steady state and isotopic steady state and show that only the latter needs to be assumed in the calculation. It is even possible to derive an estimate of the net production rate in the mixed layer that is independent of the assumption of concentration steady state. I review measurements of the parameters required for the calculation of gross production rates and show how their systematic uncertainties as well as the use of different published calculation methods can cause large variations in the production rates for the same underlying isotope ratios. In particular, the 17O excess of dissolved O2 in equilibrium with atmospheric O2 and the 17O excess of photosynthetic O2 need to be re-measured. Because of these uncertainties, all calculation parameters should always be fully documented and the measured relative isotope ratio differences as well as the
Consistent calculation of aquatic gross production from oxygen triple isotope measurements
NASA Astrophysics Data System (ADS)
Kaiser, J.
2011-04-01
Oxygen triple isotope measurements can be used to calculate aquatic gross oxygen production rates. Past studies have emphasised the appropriate definition of the 17O excess and often used an approximation to derive production rates from the 17O excess. Here, I show that the calculation can be phrased more consistently and without any approximations using the relative 17O/16O and 18O/16O isotope ratio differences directly. The 17O excess is merely a mathematical construct and the derived production rate is independent of its definition, provided all calculations are performed with a consistent definition. I focus on the mixed layer, but also show how time series of triple oxygen measurements below the mixed layer can be used to derive gross production. In the calculation of mixed layer productivity, I explicitly include isotopic fractionation during gas invasion and evasion, which requires the oxygen supersaturation s to be measured as well. I also suggest how bubble injection could be considered in the same mathematical framework. I distinguish between concentration steady state and isotopic steady state and show that only the latter needs to be assumed in the calculation. It is even possible to derive an estimate of the net production rate in the mixed layer that is independent of the assumption of concentration steady state. I review measurements of the parameters required for the calculation of gross production rates and show how their systematic uncertainties as well as the use of different published calculation methods can cause large variations in the production rates for the same underlying isotope ratios. In particular, the 17O excess of dissolved O2 in equilibrium with atmospheric O2 and the 17O excess of photosynthetic O2 need to be re-measured. Because of these uncertainties, all calculation parameters should always be fully documented and the measured isotope ratio differences as well as the oxygen supersaturation should be permanently archived, so that
Polymer reversal rate calculated via locally scaled diffusion map.
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.
Effect of tidal volume and respiratory rate on the power of breathing calculation.
Natalini, G; Marchesini, M; Tessadrelli, A; Rosano, A; Candiani, A; Bernardini, A
2005-05-01
The power of breathing (PoB) is used to estimate the mechanical workload of the respiratory system. Aim of this study was to investigate the effect of different tidal volume-respiratory rate combinations on the PoB when the elastic load is constant. In order to assure strict control of the experimental conditions, the PoB was calculated on an airway pressure-volume curve in mechanically ventilated patients. Ten patients received three different tidal volume-respiratory rate combinations while minute ventilation was constant. Respiratory mechanics, PoB and its elastic and resistive components were calculated. Alternative methods to estimate the elastic workload were assessed: elastic work of breathing per litre per minute, elastic workload index (the square root of elastic work of breathing multiplied by respiratory rate) and elastic double product of the respiratory system (the elastic pressure multiplied by respiratory rate). Despite constant elastance and minute ventilation, the elastic PoB showed an increment greater than 200% from the lower to the greater tidal volume, accounting for approximately 80% of the whole PoB increment. On the contrary, elastic work of breathing per litre per minute, elastic workload index and elastic double product did not change. Changes in breathing pattern markedly affect the PoB despite constant mechanical load. Other indexes could assess the elastic workload without tidal volume dependence. Power of breathing use should be avoided to compare different mechanical loads or efficiencies of the respiratory muscles when tidal volume is variable.
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
7 CFR 760.811 - Rates and yields; calculating payments.
Code of Federal Regulations, 2013 CFR
2013-01-01
... a loss of quantity on a unit with respect to yield-based crops are determined by multiplying the... percent of the average market price. (c) Separate payment rates and yields for the same crop may be... value based on a distinct and separate end use of the crop. Despite potential differences in yield or...
7 CFR 760.811 - Rates and yields; calculating payments.
Code of Federal Regulations, 2011 CFR
2011-01-01
... a loss of quantity on a unit with respect to yield-based crops are determined by multiplying the... percent of the average market price. (c) Separate payment rates and yields for the same crop may be... value based on a distinct and separate end use of the crop. Despite potential differences in yield or...
7 CFR 760.811 - Rates and yields; calculating payments.
Code of Federal Regulations, 2014 CFR
2014-01-01
... a loss of quantity on a unit with respect to yield-based crops are determined by multiplying the... percent of the average market price. (c) Separate payment rates and yields for the same crop may be... value based on a distinct and separate end use of the crop. Despite potential differences in yield or...
7 CFR 760.811 - Rates and yields; calculating payments.
Code of Federal Regulations, 2012 CFR
2012-01-01
... a loss of quantity on a unit with respect to yield-based crops are determined by multiplying the... percent of the average market price. (c) Separate payment rates and yields for the same crop may be... value based on a distinct and separate end use of the crop. Despite potential differences in yield or...
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…
Rate of nova production in the Galaxy
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.
Sample size calculation for comparing two negative binomial rates.
Zhu, Haiyuan; Lakkis, Hassan
2014-02-10
Negative binomial model has been increasingly used to model the count data in recent clinical trials. It is frequently chosen over Poisson model in cases of overdispersed count data that are commonly seen in clinical trials. One of the challenges of applying negative binomial model in clinical trial design is the sample size estimation. In practice, simulation methods have been frequently used for sample size estimation. In this paper, an explicit formula is developed to calculate sample size based on the negative binomial model. Depending on different approaches to estimate the variance under null hypothesis, three variations of the sample size formula are proposed and discussed. Important characteristics of the formula include its accuracy and its ability to explicitly incorporate dispersion parameter and exposure time. The performance of the formula with each variation is assessed using simulations.
Theoretical study and rate constant calculation of the CH2O+CH3 reaction
NASA Astrophysics Data System (ADS)
Liu, Jing-yao; Li, Ze-sheng; Wu, Jia-yan; Wei, Zhi-gang; Zhang, Gang; Sun, Chia-chung
2003-10-01
The potential energy surface of the CH2O+CH3 reaction is explored at the MP2/6-311++G(d,p), MP4SDQ/6-311G(d,p), and QCISD(T)/6-311+G(3df,2p) (single point) levels of theory. Theoretical calculations suggest that the major product channel (R1) is the hydrogen abstraction leading to the product P1 CHO+CH4 (R1), while the addition process leading to P2H+CH3CHO (R2) appears to be negligibly small. The calculated enthalpies and dissociation activation energies for CH3CH2O and CH3OCH2 radicals involved in the reaction are in line with the experimental values. Dual-level dynamics calculation is carried out for the direct hydrogen abstraction channel. The energy profile of (R1) is refined with the interpolated single-point energies (ISPE) method at the QCISD(T)//MP2 level. The rate constants, which are evaluated by canonical variational transition-state theory (CVT) including small-curvature tunneling (SCT) correction, are in good agreement with the available experimental data. It is shown that tunneling effect plays a significant role in the rate constant calculation; and as a result, the CVT/SCT rate constants exhibit typical non-Arrhenius behavior over a wide temperature range 300-2000 K. The three parameter expression is k=6.35×10-26 T4.4 exp(-2450/T) cm3 molecule-1 s-1.
Influence of sampling rate on the calculated fidelity of an aircraft simulation
NASA Technical Reports Server (NTRS)
Howard, J. C.
1983-01-01
One of the factors that influences the fidelity of an aircraft digital simulation is the sampling rate. As the sampling rate is increased, the calculated response of the discrete representation tends to coincide with the response of the corresponding continuous system. Because of computer limitations, however, the sampling rate cannot be increased indefinitely. Moreover, real-time simulation requirements demand that a finite sampling rate be adopted. In view of these restrictions, a study was undertaken to determine the influence of sampling rate on the response characteristics of a simulated aircraft describing short-period oscillations. Changes in the calculated response characteristics of the simulated aircraft degrade the fidelity of the simulation. In the present context, fidelity degradation is defined as the percentage change in those characteristics that have the greatest influence on pilot opinion: short period frequency omega, short period damping ratio zeta, and the product omega zeta. To determine the influence of the sampling period on these characteristics, the equations describing the response of a DC-8 aircraft to elevator control inputs were used. The results indicate that if the sampling period is too large, the fidelity of the simulation can be degraded.
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.
Dose Rate Calculation of TRU Metal Ingot in Pyroprocessing - 12202
Lee, Yoon Hee; Lee, Kunjai
2012-07-01
Spent fuel management has been a main problem to be solved for continuous utilization of nuclear energy. Spent fuel management policy of Korea is 'Wait and See'. It is focused on Pyro-process and SFR (Sodium-cooled Fast Reactor) for closed-fuel cycle research and development in Korea. For peaceful use of nuclear facilities, the proliferation resistance has to be proved. Proliferation resistance is one of key constraints in the deployment of advanced nuclear energy systems. Non-proliferation and safeguard issues have been strengthening internationally. Barriers to proliferation are that reduces desirability or attractiveness as an explosive and makes it difficult to gain access to the materials, or makes it difficult to misuse facilities and/or technologies for weapons applications. Barriers to proliferation are classified into intrinsic and extrinsic barriers. Intrinsic barrier is inherent quality of reactor materials or the fuel cycle that is built into the reactor design and operation such as material and technical barriers. As one of the intrinsic measures, the radiation from the material is considered significantly. Therefore the radiation of TRU metal ingot from the pyro-process was calculated using ORIGEN and MCNP code. (authors)
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.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-01
... International Trade Administration 19 CFR Part 351 RIN 0625-AA87 Antidumping Proceedings: Calculation of the... regarding the calculation of the weighted average dumping margin and antidumping duty assessment rate in... regarding the calculation of the weighted average dumping margin and antidumping duty assessment rate...
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.
40 CFR 75.83 - Calculation of Hg mass emissions and heat input rate.
Code of Federal Regulations, 2010 CFR
2010-07-01
... heat input rate. 75.83 Section 75.83 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Calculation of Hg mass emissions and heat input rate. The owner or operator shall calculate Hg mass emissions and heat input rate in accordance with the procedures in sections 9.1 through 9.3 of appendix F to...
Statistical Properties of SEE Rate Calculation in the Limits of Large and Small Event Counts
NASA Technical Reports Server (NTRS)
Ladbury, Ray
2007-01-01
This viewgraph presentation reviews the Statistical properties of Single Event Effects (SEE) rate calculations. The goal of SEE rate calculation is to bound the SEE rate, though the question is by how much. The presentation covers: (1) Understanding errors on SEE cross sections, (2) Methodology: Maximum Likelihood and confidence Contours, (3) Tests with Simulated data and (4) Applications.
The effect of direct positron production on relativistic feedback rates
NASA Astrophysics Data System (ADS)
Vodopiyanov, I. B.; Dwyer, J. R.; Lucia, R. J.; Cramer, E. S.; Arabshahi, S.; Rassoul, H.
2013-12-01
Relativistic feedback produces a self-sustaining runaway electron discharge via the production of backward propagating positrons and back-scattered x-rays. To date, only positrons created from pair-production by gamma-rays interacting with the air have been considered. In contrast, direct pair-production involves the creation of electron-positron pairs directly from the interaction of energetic runaway electrons with nuclei, and so it does not require the generation of bremsstrahlung gamma-rays. For high electric fields, where the runaway electron avalanche length scales are short, pair-production involving bremsstrahlung gamma-rays makes a smaller contribution to the total relativistic feedback rates than at lower fields, since both the bremsstrahlung interaction and the pair-production need to occur over a short length. On the other hand, for high fields, because direct positron production only involves one interaction, it may make a significant contribution to relativistic feedback rates in some cases. In this poster, we shall present the direct positron production cross-sections and calculate the effects on the relativistic feedback rates due to this process.
Calculation of the cross section for top quark production
Berger, E.L.; Contopanagos, H.
1996-06-21
The authors summarize calculations of the cross section for top quark production at hadron colliders within the context of perturbative quantum chromodynamics, including resummation of the effects of initial-state soft gluon radiation to all orders in the strong coupling strength. In their approach they resume the universal leading-logarithm contributions, and they restrict the calculation to the region of phase space that is demonstrably perturbative. They compare the approach with other methods. They present predictions of the physical cross section as a function of the top quark mass in proton-antiproton reactions at center-of-mass energies of 1.8 and 2.0 TeV, and they discuss estimated uncertainties.
42 CFR 413.337 - Methodology for calculating the prospective payment rates.
Code of Federal Regulations, 2010 CFR
2010-10-01
...-STAGE RENAL DISEASE SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Prospective Payment for Skilled Nursing Facilities § 413.337 Methodology for calculating the...
Predicting the production rates of cosmogenic nuclides in extraterrestrial matter
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.
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
Using a Calculated Pulse Rate with an Artificial Neural Network to Detect Irregular Interbeats.
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.
Calculations of long-lived isomer production in neutron reactions
Chadwick, M.B.; Young, P.G.
1991-01-01
We have carried out theoretical calculations for the production of the long-lived isomers {sup 93m}Nb({1/2}{sup {minus}}, 16y), {sup 121m}Sn(11/2{minus}, 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 of which pose potential radiation activation problems in nuclear fusion reactors. We consider (n, 2n), (n,n{prime}), and (n, {gamma}) production modes and compare our results both with experimental data (where available) and systematic. 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., 8 figs.
Calculations of long-lived isomer production in neutron reactions
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.
Dynamical coupled channels calculation of pion and omega meson production
Paris, Mark W.
2009-02-15
The dynamical coupled-channels approach developed at the Excited Baryon Analysis Center is extended to include the {omega}N channel to study {pi}- and {omega}-meson production induced by scattering pions and photons from the proton. Six intermediate channels, including {pi}N, {eta}N, {pi}{delta}, {sigma}N, {rho}N, and {omega}N, are employed to describe unpolarized and polarized data. Bare parameters in an effective hadronic Lagrangian are determined in a fit to the data for {pi}N{yields}{pi}N, {gamma}N{yields}{pi}N, {pi}{sup -}p{yields}{omega}n, and {gamma}p{yields}{omega}p reactions at center-of-mass energies from threshold to W<2.0 GeV. The T matrix determined in these fits is used to calculate the photon beam asymmetry for {omega}-meson production and the {omega}N{yields}{omega}N total cross section and {omega}N-scattering lengths. The calculated beam asymmetry is in good agreement with the observed in the range of energies near threshold to W < or approx. 2.0 GeV.
42 CFR 412.624 - Methodology for calculating the Federal prospective payment rates.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 2 2010-10-01 2010-10-01 false Methodology for calculating the Federal prospective... Methodology for calculating the Federal prospective payment rates. (a) Data used. To calculate the prospective..., described in paragraph (a)(3) of this section, under the update methodology described in section...
NASA Technical Reports Server (NTRS)
Hamilton, H. H., II
1982-01-01
An approximate method for calculating heating rates at general three dimensional stagnation points is presented. The application of the method for making stagnation point heating calculations during atmospheric entry is described. Comparisons with results from boundary layer calculations indicate that the method should provide an accurate method for engineering type design and analysis applications.
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.
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.
Calculating utilization rates for rubber tired grapple skidders in the Southern United States
Jason D. Thompson
2001-01-01
Utilization rate is an important factor in calculating machine rates for forest harvesting machines. Machine rates allow an evaluation of harvesting system costs and facilitate comparisons between different systems and machines. There are many factors that affect utilization rate. These include mechanical delays, non-mechanical delays, operational lost time, and...
Carbon footprint of Canadian dairy products: calculations and issues.
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
An environmental impact calculator for greenhouse production systems.
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
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.
Addressing Fission Product Validation in MCNP Burnup Credit Criticality Calculations
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 (k_{eff}) 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 k_{eff} 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 Δk_{eff} (ISG-8, Rev. 3, Recommendation 4).
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.
Maximum entropy production rate in quantum thermodynamics
NASA Astrophysics Data System (ADS)
Beretta, Gian Paolo
2010-06-01
In the framework of the recent quest for well-behaved nonlinear extensions of the traditional Schrödinger-von Neumann unitary dynamics that could provide fundamental explanations of recent experimental evidence of loss of quantum coherence at the microscopic level, a recent paper [Gheorghiu-Svirschevski 2001 Phys. Rev. A 63 054102] reproposes the nonlinear equation of motion proposed by the present author [see Beretta G P 1987 Found. Phys. 17 365 and references therein] for quantum (thermo)dynamics of a single isolated indivisible constituent system, such as a single particle, qubit, qudit, spin or atomic system, or a Bose-Einstein or Fermi-Dirac field. As already proved, such nonlinear dynamics entails a fundamental unifying microscopic proof and extension of Onsager's reciprocity and Callen's fluctuation-dissipation relations to all nonequilibrium states, close and far from thermodynamic equilibrium. In this paper we propose a brief but self-contained review of the main results already proved, including the explicit geometrical construction of the equation of motion from the steepest-entropy-ascent ansatz and its exact mathematical and conceptual equivalence with the maximal-entropy-generation variational-principle formulation presented in Gheorghiu-Svirschevski S 2001 Phys. Rev. A 63 022105. Moreover, we show how it can be extended to the case of a composite system to obtain the general form of the equation of motion, consistent with the demanding requirements of strong separability and of compatibility with general thermodynamics principles. The irreversible term in the equation of motion describes the spontaneous attraction of the state operator in the direction of steepest entropy ascent, thus implementing the maximum entropy production principle in quantum theory. The time rate at which the path of steepest entropy ascent is followed has so far been left unspecified. As a step towards the identification of such rate, here we propose a possible, well
Freely expanding detonation products: Scaling of rate processes
Greiner, N.R.
1988-01-01
Using the Los Alamos reactive hydrodynamics code KIVA, calculations have been made to simulate the free expansion of cylinders of detonation products into a high vacuum. The emphasis of this paper is on the scaling of rate processes with cylinder size and initial conditions as a function of position in the expanding mass. The processes considered include diffusion, unimolecular decomposition, biomolecular radical reactions, and vibrational relaxation. The calculations also give time-dependent velocity fields; schlieren images; and profiles of density, pressure, and temperature. Many features of the calculations can be compared with experimental observations, including time-delayed schlieren and shadowgraph snapshots, time-dependent absorption spectra, and time-of-arrival profiles of molecular species. Some unexpected insights, such as the effect of the equation of state on the shape of the expanding plume and the effect of position on the rate of quenching, are discussed. These calculations are being used to interpret the available experimental data and to design future experiments. 6 refs., 13 figs.
42 CFR 413.337 - Methodology for calculating the prospective payment rates.
Code of Federal Regulations, 2011 CFR
2011-10-01
... excluded from the data base used to compute the Federal payment rates. In addition, allowable costs related to exceptions payments under § 413.30(f) are excluded from the data base used to compute the Federal... prospective payment rates. (a) Data used. (1) To calculate the prospective payment rates, CMS uses—...
42 CFR 413.337 - Methodology for calculating the prospective payment rates.
Code of Federal Regulations, 2013 CFR
2013-10-01
... excluded from the data base used to compute the Federal payment rates. In addition, allowable costs related to exceptions payments under § 413.30(f) are excluded from the data base used to compute the Federal... prospective payment rates. (a) Data used. (1) To calculate the prospective payment rates, CMS uses—...
42 CFR 413.337 - Methodology for calculating the prospective payment rates.
Code of Federal Regulations, 2012 CFR
2012-10-01
... excluded from the data base used to compute the Federal payment rates. In addition, allowable costs related to exceptions payments under § 413.30(f) are excluded from the data base used to compute the Federal... prospective payment rates. (a) Data used. (1) To calculate the prospective payment rates, CMS uses—...
The Multi-Step CADIS method for shutdown dose rate calculations and uncertainty propagation
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.
The Multi-Step CADIS method for shutdown dose rate calculations and uncertainty propagation
Ibrahim, Ahmad M.; Peplow, Douglas E.; Grove, Robert E.; ...
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
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-12
... laboratories to conduct analyses of official meat and poultry samples. The Food, Agriculture, Conservation, and..., except on those occasions when demand exceeds supply for their products. In addition, the costs that... inelastic nature of the demand curve facing consumers. Research has shown that consumers are unlikely...
Relativistic quasiparticle random-phase approximation calculation of total muon capture rates
Marketin, T.; Paar, N.; Niksic, T.; Vretenar, D.
2009-05-15
The relativistic proton-neutron quasiparticle random phase approximation (pn-RQRPA) is applied in the calculation of total muon capture rates on a large set of nuclei from {sup 12}C to {sup 244}Pu, for which experimental values are available. The microscopic theoretical framework is based on the relativistic Hartree-Bogoliubov (RHB) model for the nuclear ground state, and transitions to excited states are calculated using the pn-RQRPA. The calculation is fully consistent, i.e., the same interactions are used both in the RHB equations that determine the quasiparticle basis, and in the matrix equations of the pn-RQRPA. The calculated capture rates are sensitive to the in-medium quenching of the axial-vector coupling constant. By reducing this constant from its free-nucleon value g{sub A}=1.262 by 10% for all multipole transitions, the calculation reproduces the experimental muon capture rates to better than 10% accuracy.
40 CFR 1066.630 - PDP, SSV, and CFV flow rate calculations.
Code of Federal Regulations, 2014 CFR
2014-07-01
...) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Calculations § 1066.630 PDP, SSV, and CFV flow rate... cross-sectional area. R = molar gas constant. p in = static absolute pressure at the venturi inlet. T...
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...
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...
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...
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...
Practical calculator programs. Part 6. Program predicts drilling time, penetration rate
Chenevert, M.E.; Hollo, R.
1981-10-05
Chenevert's program, designed for the TI-59 programmable calculator, can determine the time (hr) needed to drill a new well to a given depth and the expected penetration rate (ft/hr) at that depth. The program bases its calculations on bit records obtained from an offset well. Extrapolation of the results can predict drilling times for deeper wells.
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.
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.
Production Rates of Cosmogenic Nuclides in the Knyahinya L-Chondrite
NASA Technical Reports Server (NTRS)
Kim, K. J.; Reedy, R. C.
2004-01-01
The production rates of spallogenic radionuclides and stable isotopes in the L-chondrite Knyahinya were investigated using the MCNPX code. Numerous cosmogenic nuclides had been measured in many Knyahinya samples. The pre-atmospheric size and sample locations of Knyahinya are well known, thus Knyahinya is a good test case for cosmogenic-nuclide production-rate calculations. Our calculated profiles were compared to the measurements to determine effective proton fluxes.
Calculation of the biological effective dose for piecewise defined dose-rate fits
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.
Re-examining the Dissolution of Spent Fuel: A Comparison of Different Methods for Calculating Rates
Hanson, B D; Stout, R B
2004-04-09
Dissolution rates for spent fuel have typically been reported in terms of a rate normalized to the surface area of the specimen. Recent evidence has shown that neither the geometric surface area nor that measured with BET accurately predicts the effective surface area of spent fuel. Dissolution rates calculated from results obtained by flowthrough tests were reexamined comparing the cumulative releases and surface area normalized rates. While initial surface area is important for comparison of different rates, it appears that normalizing to the surface area introduces unnecessary uncertainty compared to using cumulative or fractional release rates. Discrepancies in past data analyses are mitigated using this alternative method.
Dose Rate Calculations for the 2-MCO/2-DHLW Waste Package
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.
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.
Influences of Response Rate and Distribution on the Calculation of Interobserver Reliability Scores
ERIC Educational Resources Information Center
Rolider, Natalie U.; Iwata, Brian A.; Bullock, Christopher E.
2012-01-01
We examined the effects of several variations in response rate on the calculation of total, interval, exact-agreement, and proportional reliability indices. Trained observers recorded computer-generated data that appeared on a computer screen. In Study 1, target responses occurred at low, moderate, and high rates during separate sessions so that…
20 CFR 10.216 - How is the pay rate for COP calculated?
Code of Federal Regulations, 2012 CFR
2012-04-01
... for COP purposes is determined according to the following formulas: (1) For full or part-time workers... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false How is the pay rate for COP calculated? 10... the preceding 52 weeks). (1) The pay rate excludes overtime pay, but includes other applicable extra...
20 CFR 10.216 - How is the pay rate for COP calculated?
Code of Federal Regulations, 2013 CFR
2013-04-01
... purposes is determined according to the following formulas: (1) For full or part-time workers (permanent or... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true How is the pay rate for COP calculated? 10.216... 52 weeks). (1) The pay rate excludes overtime pay, but includes other applicable extra pay except to...
20 CFR 10.216 - How is the pay rate for COP calculated?
Code of Federal Regulations, 2010 CFR
2010-04-01
... for COP purposes is determined according to the following formulas: (1) For full or part-time workers... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How is the pay rate for COP calculated? 10... the preceding 52 weeks). (1) The pay rate excludes overtime pay, but includes other applicable extra...
20 CFR 10.216 - How is the pay rate for COP calculated?
Code of Federal Regulations, 2014 CFR
2014-04-01
... purposes is determined according to the following formulas: (1) For full or part-time workers (permanent or... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true How is the pay rate for COP calculated? 10.216... 52 weeks). (1) The pay rate excludes overtime pay, but includes other applicable extra pay except to...
20 CFR 10.216 - How is the pay rate for COP calculated?
Code of Federal Regulations, 2011 CFR
2011-04-01
... for COP purposes is determined according to the following formulas: (1) For full or part-time workers... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false How is the pay rate for COP calculated? 10... the preceding 52 weeks). (1) The pay rate excludes overtime pay, but includes other applicable extra...
42 CFR 419.32 - Calculation of prospective payment rates for hospital outpatient services.
Code of Federal Regulations, 2012 CFR
2012-10-01
... hospital outpatient services. 419.32 Section 419.32 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... FOR HOSPITAL OUTPATIENT DEPARTMENT SERVICES Basic Methodology for Determining Prospective Payment Rates for Hospital Outpatient Services § 419.32 Calculation of prospective payment rates for hospital...
42 CFR 419.32 - Calculation of prospective payment rates for hospital outpatient services.
Code of Federal Regulations, 2013 CFR
2013-10-01
... hospital outpatient services. 419.32 Section 419.32 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... FOR HOSPITAL OUTPATIENT DEPARTMENT SERVICES Basic Methodology for Determining Prospective Payment Rates for Hospital Outpatient Services § 419.32 Calculation of prospective payment rates for hospital...
42 CFR 419.32 - Calculation of prospective payment rates for hospital outpatient services.
Code of Federal Regulations, 2014 CFR
2014-10-01
... hospital outpatient services. 419.32 Section 419.32 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... FOR HOSPITAL OUTPATIENT DEPARTMENT SERVICES Basic Methodology for Determining Prospective Payment Rates for Hospital Outpatient Services § 419.32 Calculation of prospective payment rates for hospital...
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.
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.
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.
Correlation between calculated local stability and hydrogen exchange rates in proteins.
Rashin, A A
1987-11-20
The attempt is made to find new correlations between local structural characteristics of proteins and the hydrogen exchange rates of their individual main-chain amides, and to relate such correlations to possible mechanisms of hydrogen exchange. It is found that in bovine pancreatic trypsin inhibitor (BPTI) the surface area buried by a particular residue and its neighbors correlates with the exchange rate of the main-chain amide of that residue. As the area buried by a particular fragment can be associated with the stabilization of the protein structure by this fragment, the correlation suggests a role for the energetics of the local unfolding in the mechanism of hydrogen exchange. Calculations based on the assumption that the exchange mechanism involves local unfolding lead to quantitative agreement between the calculated and experimentally measured exchange rates for 80% of the amides of BPTI that are buried or hydrogen bonded to the main-chain or to internal water molecules. The same degree of correlation is found between the calculated exchange rates and partial exchange data for ribonuclease S, hen lysozyme and cytochrome c. A similarly strong correlation is found between calculated exchange rates and the exchange rates of ribonuclease A determined by neutron diffraction in the crystal. The criteria of correlation are, however, less stringent in this case because of the experimental errors, which are larger than for solution data. It is suggested that the observed correlation be used for predictions of hydrogen exchange rates in proteins.
Homayoon, Zahra; Jambrina, Pablo G; Aoiz, F Javier; Bowman, Joel M
2012-07-14
In a previous paper [P. G. Jambrina et al., J. Chem. Phys. 135, 034310 (2011)] various calculations of the rate coefficient for the Mu + H(2) → MuH + H reaction were presented and compared to experiment. The widely used standard quasiclassical trajectory (QCT) method was shown to overestimate the rate coefficients by several orders of magnitude over the temperature range 200-1000 K. This was attributed to a major failure of that method to describe the correct threshold for the reaction owing to the large difference in zero-point energies (ZPE) of the reactant H(2) and product MuH (∼0.32 eV). In this Communication we show that by performing standard QCT calculations for the reverse reaction and then applying detailed balance, the resulting rate coefficient is in very good agreement with the other computational results that respect the ZPE, (as well as with the experiment) but which are more demanding computationally.
Ab Initio Calculation of Rate Constants for Molecule–Surface Reactions with Chemical Accuracy
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
Cheng, H
1992-04-01
A general method for calculating the mean transit times and distribution rate parameters is described. The calculations require the AUC, AUMC, and derivatives of the plasma concentration profiles of the metabolites and its precursor. The method is applicable to catenary metabolites with any precursor order and does not require separate administration of the metabolite. The approach is applied to published data for the primary and secondary metabolites of ketamine.
Rate calculations for the simultaneous vibrational relaxation and dissociation of nitrogen
NASA Technical Reports Server (NTRS)
Gonzales, David A.; Varghese, Philip L.
1992-01-01
Experimental data on vibrational relaxation and dissociation rates in highly nonequilibrium gases are scarce. Recently there have been several attempts at generating these rates by direct calculation of inelastic collision cross-sections. Some issues that need to be considered if such calculations are to be used as a basis for analysis and design are examined. In particular, the following are examined: (1) collinear vs 3D scattering models, (2) accurate intermolecular potentials, (3) closed channels and acceleration schemes, (4) thermal averaging and thermal rates, and (5) code validation. It has been necessary to confront these issues during the course of N2-N2 and N2-N inelastic cross-section calculations.
Evaluation of fission product worth margins in PWR spent nuclear fuel burnup credit calculations.
Blomquist, R.N.; Finck, P.J.; Jammes, C.; Stenberg, C.G.
1999-02-17
Current criticality safety calculations for the transportation of irradiated LWR fuel make the very conservative assumption that the fuel is fresh. This results in a very substantial overprediction of the actual k{sub eff} of the transportation casks; in certain cases, this decreases the amount of spent fuel which can be loaded in a cask, and increases the cost of transporting the spent fuel to the repository. Accounting for the change of reactivity due to fuel depletion is usually referred to as ''burnup credit.'' The US DOE is currently funding a program aimed at establishing an actinide only burnup credit methodology (in this case, the calculated reactivity takes into account the buildup or depletion of a limited number of actinides). This work is undergoing NRC review. While this methodology is being validated on a significant experimental basis, it implicitly relies on additional margins: in particular, the absorption of neutrons by certain actinides and by all fission products is not taken into account. This provides an important additional margin and helps guarantee that the methodology is conservative provided these neglected absorption are known with reasonable accuracy. This report establishes the accuracy of fission product absorption rate calculations: (1) the analysis of European fission product worth experiments demonstrates that fission product cross-sections available in the US provide very good predictions of fission product worth; (2) this is confirmed by a direct comparison of European and US cross section evaluations; (3) accuracy of Spent Nuclear Fuel (SNF) fission product content predictions is established in a recent ORNL report where several SNF isotopic assays are analyzed; and (4) these data are then combined to establish in a conservative manner the fraction of the predicted total fission product absorption which can be guaranteed based on available experimental data.
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.
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.
Rate constant calculations of H-atom abstraction reactions from ethers by HȮ2 radicals.
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.
Success rates for product development strategies in new drug development.
Dahlin, E; Nelson, G M; Haynes, M; Sargeant, F
2016-04-01
While research has examined the likelihood that drugs progress across phases of clinical trials, no research to date has examined the types of product development strategies that are the most likely to be successful in clinical trials. This research seeks to identify the strategies that are most likely to reach the market-those generated using a novel product development strategy or strategies that combine a company's expertise with both drugs and indications, which we call combined experience strategies. We evaluate the success of product development strategies in the drug development process for a sample of 2562 clinical trials completed by 406 US pharmaceutical companies. To identify product development strategies, we coded each clinical trial according to whether it consisted of an indication or a drug that was new to the firm. Accordingly, a clinical trial that consists of both an indication and a drug that were both new to the firm represents a novel product development strategy; indication experience is a product development strategy that consists of an indication that a firm had tested previously in a clinical trial, but with a drug that was new to the firm; drug experience is a product development strategy that consists of a drug that the firm had prior experience testing in clinical trials, but with an indication that was new to the firm; combined experience consists of both a drug and an indication that the firm had experience testing in clinical trials. Success rates for product development strategies across clinical phases were calculated for the clinical trials in our sample. Combined experience strategies had the highest success rate. More than three and a half percent (0·036) of the trials that combined experience with drugs and indications eventually reached the market. The next most successful strategy is drug experience (0·025) with novel strategies trailing closely (0·024). Indication experience strategies are the least successful (0·008
Krol, Marieke; Brouwer, Werner B F; Severens, Johan L; Kaper, Janneke; Evers, Silvia M A A
2012-12-01
Productivity costs related to paid work are commonly calculated in economic evaluations of health technologies by multiplying the relevant number of work days lost with a wage rate estimate. It has been argued that actual productivity costs may either be lower or higher than current estimates due to compensation mechanisms and/or multiplier effects (related to team dependency and problems with finding good substitutes in cases of absenteeism). Empirical evidence on such mechanisms and their impact on productivity costs is scarce, however. This study aims to increase knowledge on how diminished productivity is compensated within firms. Moreover, it aims to explore how compensation and multiplier effects potentially affect productivity cost estimates. Absenteeism and compensation mechanisms were measured in a randomized trial among Dutch citizens examining the cost-effectiveness of reimbursement for smoking cessation treatment. Multiplier effects were extracted from published literature. Productivity costs were calculated applying the Friction Cost Approach. Regular estimates were subsequently adjusted for (i) compensation during regular working hours, (ii) job dependent multipliers and (iii) both compensation and multiplier effects. A total of 187 respondents included in the trial were useful for inclusion in this study, based on being in paid employment, having experienced absenteeism in the preceding six months and completing the questionnaire on absenteeism and compensation mechanisms. Over half of these respondents stated that their absenteeism was compensated during normal working hours by themselves or colleagues. Only counting productivity costs not compensated in regular working hours reduced the traditional estimate by 57%. Correcting for multiplier effects increased regular estimates by a quarter. Combining both impacts decreased traditional estimates by 29%. To conclude, large amounts of lost production are compensated in normal hours. Productivity costs
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.
Calculating the rate of exothermic energy release for catalytic converter efficiency monitoring
Hepburn, J.S.; Meitzler, A.H.
1995-12-31
This paper reports on the development of a new methodology for OBD-II catalyst efficiency monitoring. Temperature measurements taken from the center of the catalyst substrate or near the exterior surface of the catalyst brick were used in conjunction with macroscopic energy balances to calculate the instantaneous rate of exothermic energy generation within the catalyst. The total calculated rate of exothermic energy release over the FTP test cycle was within 10% of the actual or theoretical value and provided a good indicator of catalyst light-off for a variety of aged catalytic converters. Normalization of the rate of exothermic energy release in the front section of the converter by the mass flow rate of air inducted through the engine was found to provide a simple yet practical means of monitoring the converter under both FTP and varying types of road driving.
Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes
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.
Panthere V2: Multipurpose Simulation Software for 3D Dose Rate Calculations
NASA Astrophysics Data System (ADS)
Penessot, Gaël; Bavoil, Éléonore; Wertz, Laurent; Malouch, Fadhel; Visonneau, Thierry; Dubost, Julien
2017-09-01
PANTHERE is a multipurpose radiation protection software developed by EDF to calculate gamma dose rates in complex 3D environments. PANTHERE takes a key role in the EDF ALARA process, enabling to predict dose rates and to organize and optimize operations in high radiation environments. PANTHERE is also used for nuclear waste characterization, transport of nuclear materials, etc. It is used in most of the EDF engineering units and their design service providers and industrial partners.
Dose rate calculations for the removal of the mixer pump from Tank 101 SY
Schwarz, R.A.
1995-02-17
Plans are currently being made for the removal of the mixer pump in tank 101 SY. Because the pump is contaminated with radioactive waste, it is essential that those involved in the pump removal operation have an indication of the expected dose rates when the pump is removed. Calculations were made to determine the dose rates for removing the pump, inserting the pump into a shipping container and filling the shipping container with either steel or lead shot for shielding.
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.
NASA Astrophysics Data System (ADS)
Truong, Thanh N.; Lu, Da-hong; Lynch, Gillian C.; Liu, Yi-Ping; Melissas, Vasilios S.; Stewart, James J. P.; Steckler, Rozeanne; Garrett, Bruce C.; Isaacson, Alan D.; Gonzalez-Lafont, Angels; Rai, Sachchida N.; Hancock, Gene C.; Joseph, Tomi; Truhlar, Donald G.
1993-04-01
We present a computer program, MORATE (Molecular Orbital RATE calculations), for direct dynamics calculations of unimolecular and bimolecular rate constants of gas-phase chemical reactions involving atoms, diatoms, or polyatomic species. The potential energies, gradients, and higher derivatives of the potential are calculated whenever needed by semiempirical molecular orbital theory without the intermediary of a global or semiglobal fit. The dynamical methods used are conventional or variational transition state theory and multidimensional semiclassical approximations for tunneling and nonclassical reflection. The computer program is conveniently interfaced package consisting of the POLYRATE program, version 4.5.1, for dynamical rate calculations, and the MOPAC program, version 5.03, for semiempirical electronic structure computations. All semiempirical methods available in MOPAC, in particular MINDO/3, MNDO, AM1, and PM3, can be called on to calculate the potential and gradient. Higher derivatives of the potential are obtained by numerical derivatives of the gradient. Variational transition states are found by a one-dimensional search of generalized-transition-state dividing surfaces perpendicular to the minimum-energy path, and tunneling probabilities are evaluated by numerical quadrature.
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,…
Estimating Virus Production Rates in Aquatic Systems
Matteson, Audrey R.; Budinoff, Charles R.; Campbell, Claire E.; Buchan, Alison; Wilhelm, Steven W.
2010-01-01
Viruses are pervasive components of marine and freshwater systems, and are known to be significant agents of microbial mortality. Developing quantitative estimates of this process is critical as we can then develop better models of microbial community structure and function as well as advance our understanding of how viruses work to alter aquatic biogeochemical cycles. The virus reduction technique allows researchers to estimate the rate at which virus particles are released from the endemic microbial community. In brief, the abundance of free (extracellular) viruses is reduced in a sample while the microbial community is maintained at near ambient concentration. The microbial community is then incubated in the absence of free viruses and the rate at which viruses reoccur in the sample (through the lysis of already infected members of the community) can be quantified by epifluorescence microscopy or, in the case of specific viruses, quantitative PCR. These rates can then be used to estimate the rate of microbial mortality due to virus-mediated cell lysis. PMID:20972392
31 CFR 356.21 - How are awards at the high yield or discount rate calculated?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false How are awards at the high yield or discount rate calculated? 356.21 Section 356.21 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT SALE...
45 CFR 261.25 - Do we count Tribal families in calculating the work participation rate?
Code of Federal Regulations, 2010 CFR
2010-10-01
... 45 Public Welfare 2 2010-10-01 2010-10-01 false Do we count Tribal families in calculating the 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...
42 CFR 413.337 - Methodology for calculating the prospective payment rates.
Code of Federal Regulations, 2014 CFR
2014-10-01
... payment rates; (ii) An appropriate wage index to adjust for area wage differences; (iii) The most recent... data that account for the relative resource utilization of different resident types; and (v) Medicare... equivalent to the annual market basket index percentage minus 1 percentage point. (3) Calculation of the...
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.
45 CFR 153.230 - Calculation of reinsurance payments made under the national contribution rate.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 45 Public Welfare 1 2013-10-01 2013-10-01 false Calculation of reinsurance payments made under the national contribution rate. 153.230 Section 153.230 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES... parameters for each benefit year commencing in 2014 and ending in 2016 set forth in the annual HHS notice of...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 45 Public Welfare 1 2013-10-01 2013-10-01 false Calculation of reinsurance payments made under a State additional contribution rate. 153.232 Section 153.232 Public Welfare DEPARTMENT OF HEALTH AND... 2014 and ending in 2016. (c) Eligibility for reinsurance payments under State supplemental reinsurance...
7 CFR 760.705 - Payment rates and calculation of payments.
Code of Federal Regulations, 2013 CFR
2013-01-01
... 7 Agriculture 7 2013-01-01 2013-01-01 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 §...
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 §...
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 §...
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 §...
Computer program for calculating and plotting fire direction and rate of spread.
James E. Eenigenburg
1987-01-01
Presents an analytical procedure that uses a FORTRAN 77 program to estimate fire direction and rate of spread. The program also calculates the variability of these parameters, both for subsections of the fire and for the fires as a whole. An option in the program allows users with a CALCOMP plotter to obtain a map of the fire with spread vectors.
Tohru Mitsunaga; Anthony H. Conner; Charles G. Hill
2002-01-01
The rates (k) of hydroxymethylation of phenol, resorcinol. phloroglucinol, and several methylphenols in diluted 10% dimethylformamide aqueous alkaline solution were calculated based on the consumption of phenols and formaldehyde. The k values of phloroglucinol and resorcinol relative to that of phenol were about 62000 and 1200 times, respectively. The phenols that have...
A simple calculation method for heavy ion induced soft error rate in space environment
NASA Astrophysics Data System (ADS)
Galimov, A. M.; Elushov, I. V.; Zebrev, G. I.
2016-12-01
In this paper based on the new parameterization shape, an alternative heavy ion induced soft errors characterization approach is proposed and validated. The method provides an unambiguous calculation procedure to predict an upset rate in highly-scaled memory in a space environment.
USDA-ARS?s Scientific Manuscript database
Inverse dispersion models are useful tools for estimating emissions from animal feeding operations, waste storage ponds, and manure application fields. Atmospheric stability is an important input parameter to such models. The objective of this study was to compare emission rates calculated with a ba...
Calculation of contraction rates due to shrinkage in light-cured composites.
Alvarez-Gayosso, Carlos; Barceló-Santana, Federico; Guerrero-Ibarra, Jorge; Sáez-Espínola, Gabriel; Canseco-Martínez, Miguel A
2004-03-01
To calculate the contraction rate that results from polymerization shrinkage in photo-cured resins. Fourteen materials were irradiated in a previously developed instrument. This instrument uses measurements of deflection using a 'bonded disk' method. Six measurements were made on each material at 20 +/- 2 degrees C and 70 +/- 10% RH. Means and standard deviations were analyzed. Shrinkage-strain and contraction rate are reported. Total shrinkage-strain for photo-polymerized resins (packable and flowable composites) varies between 1.65 and 4.16%. Both are ormocers. The contraction rate for photo-polymerized resins varies between 55.71 and 167.00 microm/min. Packable resins present a lower contraction rate than flowable resins. The distance-time graph is linear. The slope of this line is the average velocity. This concept was used to calculate the average contraction rate. The monomer percentage affects the contraction rate, because higher contraction rate means higher percentage of monomer. We can infer that contraction rate bears some relation to polymerization shrinkage.
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.
An ETAS model with varying productivity rates
NASA Astrophysics Data System (ADS)
Harte, D. S.
2014-07-01
We present an epidemic type aftershock sequenc (ETAS) model where the offspring rates vary both spatially and temporally. This is achieved by distinguishing between those space-time volumes where the interpoint space and time distances are small, and those where they are considerably larger. We also question the nature of the background component in the ETAS model. Is it simply a temporal boundary correction (t = 0) or does it represent an additional tectonic process not described by the aftershock component? The form of these stochastic models should not be considered to be fixed. As we accumulate larger and better earthquake catalogues, GPS data, strain rates, etc., we have the ability to ask more complex questions about the nature of the process. By fitting modified models consistent with such questions, we should gain a better insight into the earthquake process. Hence, we consider a sequence of incrementally modified ETAS type models rather than `the' ETAS model.
The impact of different sampling rates and calculation time intervals on ROTI values
NASA Astrophysics Data System (ADS)
Jacobsen, Knut Stanley
2014-11-01
The ROTI (Rate of TEC index) is a commonly used measure of ionospheric irregularities level. The algorithm to calculate ROTI is easily implemented, and is the same from paper to paper. However, the sample rate of the GNSS data used, and the time interval over which a value of ROTI is calculated, varies from paper to paper. When comparing ROTI values from different studies, this must be taken into account. This paper aims to show what these differences are, to increase the awareness of this issue. We have investigated the effect of different parameters for the calculation of ROTI values, using one year of data from 8 receivers at latitudes ranging from 59° N to 79° N. We have found that the ROTI values calculated using different parameter choices are strongly positively correlated. However, the ROTI values are quite different. The effect of a lower sample rate is to lower the ROTI value, due to the loss of high-frequency parts of the ROT spectrum, while the effect of a longer calculation time interval is to remove or reduce short-lived peaks due to the inherent smoothing effect. The ratio of ROTI values based on data of different sampling rate is examined in relation to the ROT power spectrum. Of relevance to statistical studies, we find that the median level of ROTI depends strongly on sample rate, strongly on latitude at auroral latitudes, and weakly on time interval. Thus, a baseline "quiet" or "noisy" level for one location or choice or parameters may not be valid for another location or choice of parameters.
Computer program FPIP-REV calculates fission product inventory for U-235 fission
NASA Technical Reports Server (NTRS)
Brown, W. S.; Call, D. W.
1967-01-01
Computer program calculates fission product inventories and source strengths associated with the operation of U-235 fueled nuclear power reactor. It utilizes a fission-product nuclide library of 254 nuclides, and calculates the time dependent behavior of the fission product nuclides formed by fissioning of U-235.
NASA Technical Reports Server (NTRS)
Kiehl, J. T.; Lacis, A. A.; Schwarzkopf, M. D.; Fels, S. B.
1991-01-01
The performance of several parameterized models is described with respect to numerical prediction and climate research at GFDL, NCAR, and GISS. The radiation codes of the models were compared to benchmark calculations and other codes for the intercomparison of radiation codes in climate models (ICRCCM). Cooling rates and fluxes calculated from the models are examined in terms of their application to established general circulation models (GCMs) from the three research institutions. The newest radiation parameterization techniques show the most significant agreement with the benchmark line-by-line (LBL) results. The LBL cooling rates correspond to cooling rate profiles from the models, but the parameterization of the water vapor continuum demonstrates uncertain results. These uncertainties affect the understanding of some lower tropospheric cooling, and therefore more accurate parameterization of the water vapor continuum, as well as the weaker absorption bands of CO2 and O3 is recommended.
CHARADE: A characteristic code for calculating rate-dependent shock-wave response
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.
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.
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.
Direct measurement of neon production rates by (α,n) reactions in minerals
NASA Astrophysics Data System (ADS)
Cox, Stephen E.; Farley, Kenneth A.; Cherniak, Daniele J.
2015-01-01
The production of nucleogenic neon from alpha particle capture by 18O and 19F offers a potential chronometer sensitive to temperatures higher than the more widely used (U-Th)/He chronometer. The accuracy depends on the cross sections and the calculated stopping power for alpha particles in the mineral being studied. Published 18O(α,n)21Ne production rates are in poor agreement and were calculated from contradictory cross sections, and therefore demand experimental verification. Similarly, the stopping powers for alpha particles are calculated from SRIM (Stopping Range of Ions in Matter software) based on a limited experimental dataset. To address these issues we used a particle accelerator to implant alpha particles at precisely known energies into slabs of synthetic quartz (SiO2) and barium tungstate (BaWO4) to measure 21Ne production from capture by 18O. Within experimental uncertainties the observed 21Ne production rates compare favorably to our predictions using published cross sections and stopping powers, indicating that ages calculated using these quantities are accurate at the ∼3% level. In addition, we measured the 22Ne/21Ne ratio and (U-Th)/He and (U-Th)/Ne ages of Durango fluorapatite, which is an important model system for this work because it contains both oxygen and fluorine. Finally, we present 21Ne/4He production rate ratios for a variety of minerals of geochemical interest along with software for calculating neon production rates and (U-Th)/Ne ages.
Development of a New Shielding Model for JB-Line Dose Rate Calculations
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.
The global joule heat production rate and the AE index
NASA Technical Reports Server (NTRS)
Wei, S.; Ahn, B.-H.; Akasofu, S.-I.
1985-01-01
The degree of accuracy with which the AE index may be used as a measure of the joule heat production rate is evaluated for a typical substorm event on March 18, 1978, by estimating the global joule heat production rate as a function of time on the basis of data obtained from the IMS's six meridian chains. It is found that, although the AE index is statistically linearly related to the global joule heat production rate, caution is required when one assumes that details of AE index time variations during individual events are representative of those of the joule heat production rate.
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.
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
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.
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.
Anischenko, Yu. A.; Gegechkori, A. E.; Nadtochy, P. N.; Adeev, G. D.
2010-04-30
The influence of the dynamical model dimensionality in use on the fission rates studied within the stochastic approach to fission dynamics [1]. Time dependence of the fission rate was calculated with the use of multidimensional Langevin equation. Particle evaporation was not taken into account. One-, two- and three-dimensional cases were considered on the basis of the left bracec, h, alpharight brace-parametrization of the nuclear surface shape. Calculations were performed for the large number of compound nuclei with Z{sup 2}/A parameter in the range 20
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.
Approximate method for calculating heating rates on three-dimensional vehicles
NASA Astrophysics Data System (ADS)
Hamilton, H. Harris; Greene, Francis A.; Dejarnette, F. R.
1994-05-01
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.
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.
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.
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.
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.
Dalla Pozza, Robert; Kleinmann, Arne; Bechtold, Susanne; Kozlik-Feldmann, R; Daebritz, S; Netz, Heinrich
2006-06-01
Assessing sympathovagal balance by calculating LF/HF-ratio from power spectral analysis (PSA) of heart rate variability (HRV) may be difficult in adolescents as chaotic breathing leads to methodical bias and metronomic breathing is not easy to perform. Diastolic blood pressure variability (dBPV) is less influenced and may therefore offer more stable values for calculations. The present study was performed on 72 paediatric subjects to investigate possible alternative LF/HF-calculations from PSA of HRV and dBPV. Seventy-two paediatric individuals in three groups: 12 controls, 17 heart- and heart-lung-transplanted children (TX) and 43 adolescents born small for gestational age (SGA). Short-term beat-to-beat HRV and BP-recordings were made supine and during active standing. Ratios calculated: LF/HF from HRV, LF/HF from dBPV, LF-dBPV/HF-HRV and LF-HRV/HF-dBPV. LF/HF from dBPV as well as LF-HRV/HF-dBPV did not correlate with LF/HF-HRV. Correlation of LF/HF from HRV and LF-dBPV/HF-HRV was high especially in TX and in patients with resting heart rate of above 90 beats per minute. In adolescents, the ratio of LF-dBPV/HF-HRV may be an alternative method for calculating sympathicovagal balance being less influenced by breathing patterns. In younger patients with elevated resting heart rate, but also in patients with very low HRV such as TX-patients this method could be a supplemental diagnostic tool whenever autonomic nervous control on the cardiocirculatory system has to be assessed.
Su, Jian; Yu, Wen; Zeng, Zhi; Ma, Hao; Chen, Liqi; Cheng, Jianping
2014-03-01
After the Fukushima nuclear accident, there is a widespread concern over the radioactive contamination of the marine environment. To protect non-human species, a radiation dose rate calculation model for Western Pacific marine species was established. Ten kinds of marine species in the Western Pacific were modelled by Geant4 for Monte Carlo simulation. Organisms were modelled with two ellipsoids: one represented organs and the other represented muscle. The enhanced dose rates by 10 main kinds of nuclides were calculated. According to the reported activities of three main nuclides ((134)Cs, (137)Cs and (131)I) in seawater near Fukushima coastal, the radiation risks of marine species were estimated. The results showed that the marine species near the Fukushima accident drain outlets might be at risk. But organisms that were >15 km away from the drain outlets were relatively safe.
Optimal power flow calculation for power system with UPFC considering load rate equalization
NASA Astrophysics Data System (ADS)
Liu, Jiankun; Chen, Jing; Zhang, Qingsong
2017-06-01
Unified power flow controller (UPFC) device can change system electrical quantity (such as voltage, impedance, phase angle, etc.) rapidly and flexibly under the premise of maintain security, stability and reliability of power system, thus can improve the transmission power and transmission line utilization, so as to enhance the power supply capacity of the power grid. Based on a thorough study of the steady-state model of UPFC, taking load rate equalization as objective function, the optimal power flow model is established with UPFC, and simplified interior point method is used to solve it. Finally, optimal power flow of 24 continuous sections actual data is calculated on a typical day of Nanjing network. The results show that the optimal power flow calculation with UPFC can optimize the load rate equalization on the basis of eliminating line overload, improving the voltage level of local power network.
NASA Astrophysics Data System (ADS)
Voropaeva, Z. I.
2010-01-01
The comparative assessment of methods for the calculation of the gypsum application rates based on the exchangeable sodium (Gedroits, Schollenberger), the estimated sodium (Schoonover), and the soil’s requirement for calcium (the version of the Omsk State Agrarian University) showed that, for the chemical amelioration of solonetzes with different contents of exchangeable sodium in Western Siberia, it is economically and ecologically advisable to calculate the ameliorant application rates from the estimated sodium. It was experimentally shown that the content of displaced magnesium used by Schoonover is a more efficient unified criterion than the value of the calcium adsorption by zonal soils. For improving the method’s accuracy, it was proposed to change the conditions of the soil preparation by regulating the concentration of the displacing solution, the interaction time, and the temperature.
Efficient calculation of degenerate atomic rates by numerical quadrature on GPUs
NASA Astrophysics Data System (ADS)
Aslanyan, V.; Aslanyan, A. G.; Tallents, G. J.
2017-10-01
The rates of atomic processes in cold, dense plasma are governed strongly by effects of quantum degeneracy. The electrons follow Fermi-Dirac statistics and their high density limits the number of quantum states available for occupation after a collision. These factors preclude a direct solution to the usual rate coefficient integrals. We summarize the formulation of this problem and present a simple, but efficient method of evaluating collisional rate coefficients via direct numerical integration. Numerical quadrature has an intrinsically high level of parallelism, ideally suited for graphics processor units. GPUs are particularly suited to this problem because of the large number of integrals which must be carried out simultaneously for a given atomic model. A CUDA code to calculate the rates of significant atomic processes as part of a collisional-radiative model is presented and discussed. This approach may be readily extended to other applications where rapid and repeated evaluation of many integrals is required.
External dose-rate conversion factors for calculation of dose to the public
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.
Ab initio calculations of energy levels, transition rates and lifetimes in Ni xii
NASA Astrophysics Data System (ADS)
Bilal, M.; Beerwerth, R.; Volotka, A. V.; Fritzsche, S.
2017-08-01
We report large-scale multi-configuration Dirac-Hartree-Fock calculations and relativistic configuration interaction calculations for allowed E1 and forbidden transitions (M1, E2, M2) among the fine structure levels of the 3s23p5, 3s3p6 and 3s23p43d configurations for Ni xii. In our systematically enlarged wave functions, we incorporated the effects of relativity, all important electron correlations and rearrangement of the bound electron density within two different computational models. We compare our calculated energies for the fine structure levels with previous calculations and experiments. We validate all the tentative experimental lines recently identified by Del Zanna & Badnell with one exception. We discuss the consistency of our transition rates in comparison to semi-empirical predictions. We present ab initio lifetime values by taking into account all allowed E1 and forbidden transitions (M1, E2, M2) rates among lowest 31 levels. Our results for lifetime values are better than previously reported ab initio and semi-empirical values as compared to available experiments, thus, providing reliable predictions in the prospects of future experiments.
Entrained liquid fraction calculation in adiabatic disperse-annular flows at low rate in film
NASA Astrophysics Data System (ADS)
Yagov, V. V.; Minko, M. V.
2016-04-01
In this work, we continue our study [1] and extend further an approach to low reduced pressures. An approximate model of droplets entrainment from the laminar film surface and an equation for calculating entrainment intensity are proposed. To carry out direct verification of this equation using experimental data is extremely difficult because the integral effect—liquid flow rate in a film at a dynamic equilibrium between entrainment and deposition—is usually measured in the experiments. The balance between flows of droplets entrainment and deposition corresponds to the dynamic equilibrium because of turbulent diffusion. The transcendental equation, which was obtained on the basis of this balance, contains one unknown numerical factor and allows one to calculate the liquid rate. Comparing calculation results with the experimental data for the water-air and water-helium flows at low reduced pressures (less than 0.03) has shown their good agreement at the universal value of a numerical constant, if an additional dimensionless parameter, a fourth root of vaporliquid densities ratio, is introduced. The criterion that determines the boundary of using methods of this work and that of [1] in calculations and that reflects effect of pressure and state of film surface on distribution of the liquid in the annular flow is proposed; the numerical value of this criterion has been determined.
Graduation Rates and Accountability: Regressions versus Production Frontiers
ERIC Educational Resources Information Center
Archibald, Robert B.; Feldman, David H.
2008-01-01
This paper suggests an alternative to the standard practice of measuring the graduation rate performance using regression analysis. The alternative is production frontier analysis. Production frontier analysis is appealing because it compares an institution's graduation rate to the best performance instead of the average performance. The paper…
Graduation Rates and Accountability: Regressions versus Production Frontiers
ERIC Educational Resources Information Center
Archibald, Robert B.; Feldman, David H.
2008-01-01
This paper suggests an alternative to the standard practice of measuring the graduation rate performance using regression analysis. The alternative is production frontier analysis. Production frontier analysis is appealing because it compares an institution's graduation rate to the best performance instead of the average performance. The paper…
Production rates for crews using hand tools on firelines
Lisa Haven; T. Parkin Hunter; Theodore G. Storey
1982-01-01
Reported rates at which hand crews construct firelines can vary widely because of differences in fuels, fire and measurement conditions, and fuel resistance-to-control classification schemes. Real-time fire dispatching and fire simulation planning models, however, require accurate estimates of hand crew productivity. Errors in estimating rate of fireline production...
CASCADE CALCULATION OF EXOTIC HELIUM ATOMS -- s-orbit vs. p-orbit absorption rates
NASA Astrophysics Data System (ADS)
Koike, T.; Akaishi, Y.
2000-09-01
We construct a new model for the Stark-mixing process of exotic helium atoms using the impact-parameter method, and compared it with a phenomenological one used so far (sliding transition model). It turns out that the sliding transition model is justified only for low-n states and largely overestimates the Stark-mixing transition rate at high-n states. As a result of the atomic-cascade calculation, the s-(p-)orbit absorption rates in our new model are considerably smaller (larger) than those in the phenomenological one, although both our new model and old one well reproduce the experimental x-ray yields.
van der Spoel, D; Berendsen, H J
1996-01-01
In this work we give an overview of the methodologies required to compute the rate of proton transfer in hydrogen bonded systems in solution. Using ab initio or density functional methods we determine proton potentials of a truncated system as a function of proton-donor proton-acceptor distance as well as nonbonding parameters. By classical molecular dynamics we evaluate a swarm of proton potentials with the proton fixed in the reactant well. The rate of proton transfer is calculated perturbatively using the Density Matrix Evolution (DME) method, going beyond the Born Oppenheimer approximation. The method is illustrated by two examples: hydrogen malonate and the active center of HIV-1 protease.
Diffusion Rates for Hydrogen on Pd(111) from Molecular Quantum Dynamics Calculations.
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.
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.
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.
Assessments of fluid friction factors for use in leak rate calculations
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.
Schaffner, D W
1994-12-01
The inherent variability or 'variance' of growth rate measurements is critical to the development of accurate predictive models in food microbiology. A large number of measurements are typically needed to estimate variance. To make these measurements requires a significant investment of time and effort. If a single growth rate determination is based on a series of independent measurements, then a statistical bootstrapping technique can be used to simulate multiple growth rate measurements from a single set of experiments. Growth rate variances were calculated for three large datasets (Listeria monocytogenes, Listeria innocua, and Yersinia enterocolitica) from our laboratory using this technique. This analysis revealed that the population of growth rate measurements at any given condition are not normally distributed, but instead follow a distribution that is between normal and Poisson. The relationship between growth rate and temperature was modeled by response surface models using generalized linear regression. It was found that the assumed distribution (i.e. normal, Poisson, gamma or inverse normal) of the growth rates influenced the prediction of each of the models used. This research demonstrates the importance of variance and assumptions about the statistical distribution of growth rates on the results of predictive microbiological models.
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
Regulation of primary productivity rate in the equatorial Pacific
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.
Reidlinger, D P; Willis, J M; Whelan, K
2015-02-01
Accurate assessment of energy expenditure and anthropometry in older people is important for targeted nutritional support. The present study aimed to compare measured and calculated resting metabolic rate (m-RMR and c-RMR) and measured, calculated and estimated weight and height in older people aged ≥70 years. Participants were healthy older people aged ≥70 years. Indirect calorimetry using a ventilated hood calorimeter was performed for 30 min on fasted participants, and was compared with c-RMR, as calculated using six commonly used equations. Measured, calculated and estimated height and weight were compared. Subjects comprised 14 males and 20 females and mean (SD) m-RMR was 5243 (845) kJ day(-1) [1253 (202) kcal day(-1) ]. The Mifflin St-Jeor equation was the most consistently accurate, with the smallest mean difference between m-RMR and c-RMR of 58 (553) kJ day(-1) [14 (132) kcal day(-1) ] and c-RMR was within 10% of m-RMR in the greatest number of participants (n = 24; 70%). The Schofield equation was among the least accurate in this age group. In older males, self-reported height and weight were accurate, whereas, in females or those unable to self-report height, ulna length was the most accurate alternative to measured height. Current equations used to calculate RMR in older people have inaccuracies, although the Mifflin St-Jeor equation was most accurate. Future studies should investigate the validity, reliability, cost and practicality of using fat free mass as an item in novel equations to calculate RMR in this age group. Self-reported height and weight in males, and height calculated from ulna length in females, were the most accurate alternatives to measured values in the present study. © 2014 The British Dietetic Association Ltd.
Calculation of Top Squark Production in Proton-Proton Collisions
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.
Resolving an ostensible inconsistency in calculating the evaporation rate of sessile drops.
Chini, S F; Amirfazli, A
2016-06-04
This paper resolves an ostensible inconsistency in the literature in calculating the evaporation rate for sessile drops in a quiescent environment. The earlier models in the literature have shown that adapting the evaporation flux model for a suspended spherical drop to calculate the evaporation rate of a sessile drop needs a correction factor; the correction factor was shown to be a function of the drop contact angle, i.e. f(θ). However, there seemed to be a problem as none of the earlier models explicitly or implicitly mentioned the evaporation flux variations along the surface of a sessile drop. The more recent evaporation models include this variation using an electrostatic analogy, i.e. the Laplace equation (steady-state continuity) in a domain with a known boundary condition value, or known as the Dirichlet problem for Laplace's equation. The challenge is that the calculated evaporation rates using the earlier models seemed to differ from that of the recent models (note both types of models were validated in the literature by experiments). We have reinvestigated the recent models and found that the mathematical simplifications in solving the Dirichlet problem in toroidal coordinates have created the inconsistency. We also proposed a closed form approximation for f(θ) which is valid in a wide range, i.e. 8°≤θ≤131°. Using the proposed model in this study, theoretically, it was shown that the evaporation rate in the CWA (constant wetted area) mode is faster than the evaporation rate in the CCA (constant contact angle) mode for a sessile drop.
Calculation and manipulation of the chirp rates of high-order harmonics
Murakami, M.; Mauritsson, J.; Schafer, K.J.; Gaarde, M.B.; L'Huillier, A.
2005-01-01
We calculate the linear chirp rates of high-order harmonics in argon, generated by intense, 810 nm laser pulses, and explore the dependence of the chirp rate on harmonic order, driving laser intensity, and pulse duration. By using a time-frequency representation of the harmonic fields we can identify several different linear chirp contributions to the plateau harmonics. Our results, which are based on numerical integration of the time-dependent Schroedinger equation, are in good agreement with the adiabatic predictions of the strong field approximation for the chirp rates. Extending the theoretical analysis in the recent paper by Mauritsson et al. [Phys. Rev. A 70, 021801(R) (2004)], we also manipulate the chirp rates of the harmonics by adding a chirp to the driving pulse. We show that the chirp rate for harmonic q is given by the sum of the intrinsic chirp rate, which is determined by the new duration and peak intensity of the chirped driving pulse, and q times the external chirp rate.
Comparison of measured and calculated dose rates for the Castor HAW 20/28 CG.
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.
Production rate of second KK gauge bosons in UED models at LHC
Matsumoto, Shigeki; Sato, Joe; Yamanaka, Masato; Senami, Masato
2009-04-17
We calculate the production rates of the second KK photons and the second KK Z bosons at the LHC in a framework of universal extra dimension models. In the hadron collider experiment, it can be difficult to distinguish the signal of KK particles in universal extra dimension models from that of unknown heavy particles in TeV scale new models. For the discrimination, the second KK gauge bosons play an important role. Thus we calculate the production rates of the second KK gauge bosons at the LHC including all significant processes, and discuss the feasibility to confirm universal extra dimension models at the LHC.
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.
Logging production rates in young-growth, mixed-conifer stands in north central California
Philip M. McDonald
1972-01-01
To quantify production rates for small trees, this study examined the components of log-making and tractor yarding at the Challenge Experimental Forest, Yuba County, California. Rates were calculated over a range of 12 to 40 inches d.b.h. The rate for incense-cedar was lowest; for ponderosa pine it was intermediate; and for Douglas-fir, white fir, and sugar pine...
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.
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.
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.
NASA Astrophysics Data System (ADS)
Yang, Bing; Liao, Zhen; Qin, Yahang; Wu, Yayun; Liang, Sai; Xiao, Shoune; Yang, Guangwu; Zhu, Tao
2017-05-01
To describe the complicated nonlinear process of the fatigue short crack evolution behavior, especially the change of the crack propagation rate, two different calculation methods are applied. The dominant effective short fatigue crack propagation rates are calculated based on the replica fatigue short crack test with nine smooth funnel-shaped specimens and the observation of the replica films according to the effective short fatigue cracks principle. Due to the fast decay and the nonlinear approximation ability of wavelet analysis, the self-learning ability of neural network, and the macroscopic searching and global optimization of genetic algorithm, the genetic wavelet neural network can reflect the implicit complex nonlinear relationship when considering multi-influencing factors synthetically. The effective short fatigue cracks and the dominant effective short fatigue crack are simulated and compared by the Genetic Wavelet Neural Network. The simulation results show that Genetic Wavelet Neural Network is a rational and available method for studying the evolution behavior of fatigue short crack propagation rate. Meanwhile, a traditional data fitting method for a short crack growth model is also utilized for fitting the test data. It is reasonable and applicable for predicting the growth rate. Finally, the reason for the difference between the prediction effects by these two methods is interpreted.
Suess, Christian J; Hirst, Jonathan D; Besley, Nicholas A
2017-04-01
The development of optical multidimensional spectroscopic techniques has opened up new possibilities for the study of biological processes. Recently, ultrafast two-dimensional ultraviolet spectroscopy experiments have determined the rates of tryptophan → heme electron transfer and excitation energy transfer for the two tryptophan residues in myoglobin (Consani et al., Science, 2013, 339, 1586). Here, we show that accurate prediction of these rates can be achieved using Marcus theory in conjunction with time-dependent density functional theory. Key intermediate residues between the donor and acceptor are identified, and in particular the residues Val68 and Ile75 play a critical role in calculations of the electron coupling matrix elements. Our calculations demonstrate how small changes in structure can have a large effect on the rates, and show that the different rates of electron transfer are dictated by the distance between the heme and tryptophan residues, while for excitation energy transfer the orientation of the tryptophan residues relative to the heme is important. © 2017 The Authors Journal of Computational Chemistry Published by Wiley Periodicals, Inc.
Calculating in situ degradation rates of hydrocarbon compounds in deep waters of the Gulf of Mexico.
Thessen, Anne E; North, Elizabeth W
2017-09-15
Biodegradation is an important process for hydrocarbon weathering that influences its fate and transport, yet little is known about in situ biodegradation rates of specific hydrocarbon compounds in the deep ocean. Using data collected in the Gulf of Mexico below 700m during and after the Deepwater Horizon oil spill, we calculated first-order degradation rate constants for 49 hydrocarbons and inferred degradation rate constants for an additional 5 data-deficient hydrocarbons. Resulting calculated (not inferred) half-lives of the hydrocarbons ranged from 0.4 to 36.5days. The fastest degrading hydrocarbons were toluene (k=-1.716), methylcyclohexane (k=-1.538), benzene (k=-1.333), and C1-naphthalene (k=-1.305). The slowest degrading hydrocarbons were the large straight-chain alkanes, C-26 through C-33 (k=-0.0494 through k=-0.007). Ratios of C-18 to phytane supported the hypothesis that the primary means of degradation in the subsurface was microbial biodegradation. These degradation rate constants can be used to improve models describing the fate and transport of hydrocarbons in the event of an accidental deep ocean oil spill. Copyright © 2017 Elsevier Ltd. All rights reserved.
Improved estimates of environmental copper release rates from antifouling products.
Finnie, Alistair A
2006-01-01
The US Navy Dome method for measuring copper release rates from antifouling paint in-service on ships' hulls can be considered to be the most reliable indicator of environmental release rates. In this paper, the relationship between the apparent copper release rate and the environmental release rate is established for a number of antifouling coating types using data from a variety of available laboratory, field and calculation methods. Apart from a modified Dome method using panels, all laboratory, field and calculation methods significantly overestimate the environmental release rate of copper from antifouling coatings. The difference is greatest for self-polishing copolymer antifoulings (SPCs) and smallest for certain erodible/ablative antifoulings, where the ASTM/ISO standard and the CEPE calculation method are seen to typically overestimate environmental release rates by factors of about 10 and 4, respectively. Where ASTM/ISO or CEPE copper release rate data are used for environmental risk assessment or regulatory purposes, it is proposed that the release rate values should be divided by a correction factor to enable more reliable generic environmental risk assessments to be made. Using a conservative approach based on a realistic worst case and accounting for experimental uncertainty in the data that are currently available, proposed default correction factors for use with all paint types are 5.4 for the ASTM/ISO method and 2.9 for the CEPE calculation method. Further work is required to expand this data-set and refine the correction factors through correlation of laboratory measured and calculated copper release rates with the direct in situ environmental release rate for different antifouling paints under a range of environmental conditions.
Patient-specific dose calculation methods for high-dose-rate iridium-192 brachytherapy
NASA Astrophysics Data System (ADS)
Poon, Emily S.
In high-dose-rate 192Ir brachytherapy, the radiation dose received by the patient is calculated according to the AAPM Task Group 43 (TG-43) formalism. This table-based dose superposition method uses dosimetry parameters derived with the radioactive 192Ir source centered in a water phantom. It neglects the dose perturbations caused by inhomogeneities, such as the patient anatomy, applicators, shielding, and radiographic contrast solution. In this work, we evaluated the dosimetric characteristics of a shielded rectal applicator with an endocavitary balloon injected with contrast solution. The dose distributions around this applicator were calculated by the GEANT4 Monte Carlo (MC) code and measured by ionization chamber and GAFCHROMIC EBT film. A patient-specific dose calculation study was then carried out for 40 rectal treatment plans. The PTRAN_CT MC code was used to calculate the dose based on computed tomography (CT) images. This study involved the development of BrachyGUI, an integrated treatment planning tool that can process DICOM-RT data and create PTRAN_CT input initialization files. BrachyGUI also comes with dose calculation and evaluation capabilities. We proposed a novel scatter correction method to account for the reduction in backscatter radiation near tissue-air interfaces. The first step requires calculating the doses contributed by primary and scattered photons separately, assuming a full scatter environment. The scatter dose in the patient is subsequently adjusted using a factor derived by MC calculations, which depends on the distances between the point of interest, the 192Ir source, and the body contour. The method was validated for multicatheter breast brachytherapy, in which the target and skin doses for 18 patient plans agreed with PTRAN_CT calculations better than 1%. Finally, we developed a CT-based analytical dose calculation method. It corrects for the photon attenuation and scatter based upon the radiological paths determined by ray tracing
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.
Shakib, Farnaz; Hanna, Gabriel
2016-07-12
In this work, we derive a general mixed quantum-classical formula for calculating thermal proton-coupled electron-transfer (PCET) rate constants, starting from the time integral of the quantum flux-flux correlation function. This formula allows for the direct simulation of PCET reaction dynamics via the mixed quantum-classical Liouville approach. Owing to the general nature of the derivation, this formula does not rely on any prior mechanistic assumptions and can be applied across a wide range of electronic and protonic coupling regimes. To test the validity of this formula, we applied it to a reduced model of a condensed-phase PCET reaction. Good agreement with the numerically exact rate constant is obtained, demonstrating the accuracy of our formalism. We believe that this approach constitutes a solid foundation for future investigations of the rates and mechanisms of a wide range of PCET reactions.
Quantum three-body calculation of nonresonant triple-{alpha} reaction rate at low temperatures
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.
Quantum three-body calculation of nonresonant triple-alpha reaction rate at low temperatures
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.
The importance of metabolic rate and the folly of body surface area calculations.
Gibson, S; Numa, A
2003-01-01
Mathematical formulae to calculate body surface area from measurements of height, weight and other parameters date from the late 19th century. Drug doses, fluid therapy, caloric requirements and physiological parameters such as cardiac output, glomerular filtration rate and a variety of respiratory function parameters are all frequently expressed in terms of a body surface area. Body surface area is often used in preference to body mass (weight). However, the original rationale for using body surface area as an estimate for metabolic rate has never been tested and the algorithms used to approximate body surface area have little evidence to support their use in this role. Recent developments in technology using indirect calorimetry allow easy measurement of metabolic rate in the clinical setting. Such measurements should be used for standardisation when weight alone is considered inadequate.
Evaluating range-expansion models for calculating nonnative species' expansion rate
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
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
45 CFR 261.36 - Do welfare reform waivers affect the calculation of a State's participation rates?
Code of Federal Regulations, 2012 CFR
2012-10-01
... of a State's participation rates? 261.36 Section 261.36 Public Welfare Regulations Relating to Public... They Count? § 261.36 Do welfare reform waivers affect the calculation of a State's participation rates? A welfare reform waiver could affect the calculation of a State's participation rate, pursuant...
45 CFR 261.36 - Do welfare reform waivers affect the calculation of a State's participation rates?
Code of Federal Regulations, 2010 CFR
2010-10-01
... of a State's participation rates? 261.36 Section 261.36 Public Welfare Regulations Relating to Public... They Count? § 261.36 Do welfare reform waivers affect the calculation of a State's participation rates? A welfare reform waiver could affect the calculation of a State's participation rate, pursuant...
45 CFR 261.36 - Do welfare reform waivers affect the calculation of a State's participation rates?
Code of Federal Regulations, 2014 CFR
2014-10-01
... a State's participation rates? 261.36 Section 261.36 Public Welfare Regulations Relating to Public... They Count? § 261.36 Do welfare reform waivers affect the calculation of a State's participation rates? A welfare reform waiver could affect the calculation of a State's participation rate, pursuant...
45 CFR 261.36 - Do welfare reform waivers affect the calculation of a State's participation rates?
Code of Federal Regulations, 2013 CFR
2013-10-01
... a State's participation rates? 261.36 Section 261.36 Public Welfare Regulations Relating to Public... They Count? § 261.36 Do welfare reform waivers affect the calculation of a State's participation rates? A welfare reform waiver could affect the calculation of a State's participation rate, pursuant...
45 CFR 261.36 - Do welfare reform waivers affect the calculation of a State's participation rates?
Code of Federal Regulations, 2011 CFR
2011-10-01
... of a State's participation rates? 261.36 Section 261.36 Public Welfare Regulations Relating to Public... They Count? § 261.36 Do welfare reform waivers affect the calculation of a State's participation rates? A welfare reform waiver could affect the calculation of a State's participation rate, pursuant...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-17
... SECURITY U.S. Customs and Border Protection Quarterly IRS Interest Rates Used in Calculating Interest on... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and... interest rate for underpayments will be 3 percent for both corporations and non-corporations. This notice...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-10-23
... SECURITY U.S. Customs and Border Protection Quarterly IRS Interest Rates Used in Calculating Interest on... Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and... interest rate for underpayments will be 3 percent for both corporations and non-corporations. This notice...
NASA Astrophysics Data System (ADS)
Adam, J.; Tater, M.; Truhlík, E.; Epelbaum, E.; Machleidt, R.; Ricci, P.
2012-03-01
The doublet capture rate Λ1 / 2 of the negative muon capture in deuterium is calculated employing the nuclear wave functions generated from accurate nucleon-nucleon (NN) potentials constructed at next-to-next-to-next-to-leading order of heavy-baryon chiral perturbation theory and the weak meson exchange current operator derived within the same formalism. All but one of the low-energy constants that enter the calculation were fixed from pion-nucleon and nucleon-nucleon scattering data. The low-energy constant dˆR (cD), which cannot be determined from the purely two-nucleon data, was extracted recently from the triton β-decay and the binding energies of the three-nucleon systems. The calculated values of Λ1 / 2 show a rather large spread for the used values of the dˆR. Precise measurement of Λ1 / 2 in the future will not only help to constrain the value of dˆR, but also provide a highly nontrivial test of the nuclear chiral EFT framework. Besides, the precise knowledge of the constant dˆR will allow for consistent calculations of other two-nucleon weak processes, such as proton-proton fusion and solar neutrino scattering on deuterons, which are important for astrophysics.
Quantum Tunneling Rates of Gas-Phase Reactions from On-the-Fly Instanton Calculations.
Beyer, Adrian N; Richardson, Jeremy O; Knowles, Peter J; Rommel, Judith; Althorpe, Stuart C
2016-11-03
The instanton method obtains approximate tunneling rates from the minimum-action path (known as the instanton) linking reactants to the products at a given temperature. An efficient way to find the instanton is to search for saddle-points on the ring-polymer potential surface, which is obtained by expressing the quantum Boltzmann operator as a discrete path-integral. Here we report a practical implementation of this ring-polymer form of instanton theory into the Molpro electronic-structure package, which allows the rates to be computed on-the-fly, without the need for a fitted analytic potential-energy surface. As a test case, we compute tunneling rates for the benchmark H + CH4 reaction, showing how the efficiency of the instanton method allows the user systematically to converge the tunneling rate with respect to the level of electronic-structure theory.
A line rate calculation method for arbitrary directional imaging of an Earth observing satellite
NASA Astrophysics Data System (ADS)
Jeon, Moon-Jin; Kim, Eunghyun; Lim, Seong-Bin; Choi, Seok-Weon
2016-10-01
For an earth observing satellite, a line rate is the number of lines which the CCD of push broom type camera scans in a second. It can be easily calculated by ground velocity divided by ground sample distance. Accurate calculation of line rate is necessary to obtain high quality image using TDI CCD. The earth observing satellite has four types of imaging missions which are strip imaging, stereo imaging, multi-point imaging, and arbitrary directional imaging. For the first three types of imaging, ground scanning direction is aligned with satellite velocity direction. Therefore, if the orbit propagation and spacecraft attitude information are available, the ground velocity and ground sample distance could be easily calculated. However, the calculation method might not be applicable to the arbitrary directional imaging. In the arbitrary directional imaging mode, the ground velocity is not fixed value which could be directly derived by orbit information. Furthermore, the ground sample distance might not be easily calculated by simple trigonometry which is possible for the other types of imaging. In this paper, we proposed a line rate calculation method for the arbitrary directional imaging. We applied spherical geometry to derive the equation of ground point which is the intersection between the line of sight vector of the camera and earth surface. The derivative of this equation for time is the ground velocity except the factor of earth rotation. By adding this equation and earth rotation factor, the true ground velocity vector could be derived. For the ground sample distance, we applied the equation of circle and ellipse for yaw angle difference. The equation of circle is used for the yaw angle representation on the plane which is orthogonal to the line of sight vector. The equation of ellipse is used for the yaw angle representation on the ground surface. We applied the proposed method to the KOMPSAT-3A (Korea Multi-Purpose Satellite 3A) mission which is the first
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.
Benchmarking of MCNP for calculating dose rates at an interim storage facility for nuclear waste.
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.
Energy Release Rate Calculations for Interface Edge Cracks Based on a Conservation Integral.
1979-11-01
Smelzer and Curtin [2], is that the 3—integral on a small arc about an interface crack is equal to the energy release rate, as in the homogeneous case. One...2.. (See Rice [4] and Smelzer and Gurtin (2].) Rence , on this small arc, H is the product of the crack length and the rate of decrease of the energy...Solids Structures , 14, 241—250 (1978). 2. R. E. Smelzer and N . E. Gurtin , On the J—integral for bi—material bodies. Tn t . J. Fr act . 13, 382—3S4
Hypotheses of calculation of the water flow rate evaporated in a wet cooling tower
Bourillot, C.
1983-08-01
The method developed by Poppe at the University of Hannover to calculate the thermal performance of a wet cooling tower fill is presented. The formulation of Poppe is then validated using full-scale test data from a wet cooling tower at the power station at Neurath, Federal Republic of Germany. It is shown that the Poppe method predicts the evaporated water flow rate almost perfectly and the condensate content of the warm air with good accuracy over a wide range of ambient conditions. The simplifying assumptions of the Merkel theory are discussed, and the errors linked to these assumptions are systematically described, then illustrated with the test data.
Vadimova, O L; Mukhin, I B; Kuznetsov, I I; Palashov, O V; Perevezentsev, E A; Khazanov, Efim A
2013-03-31
We have calculated the stored energy and gain coefficient in disk gain elements cooled to cryogenic temperatures. The problem has been solved with allowance for intense heat generation, amplified spontaneous emission and parasitic lasing, without averaging over any spatial coordinate. The numerical simulation results agree well with experimental data, in particular at high heat generation rates. Experimental data and theoretical analysis indicate that composite disk gain elements containing an undoped region can store considerably more energy due to suppression of amplified spontaneous emission and parasitic lasing. (extreme light fields and their applications)
Advanced Fuel Cycle Initiative - Projected Linear Heat Generation Rate and Burnup Calculations
Richard G. Ambrosek; Gray S. Chang; Debbie J. Utterbeck
2005-02-01
This report provides documentation of the physics analysis performed to determine the linear heat generation rate (LHGR) and burnup calculations for the Advanced Fuel Cycle Initiative (AFCI) tests, AFC-1D, AFC-1H, and AFC-1G. The AFC-1D and AFC-1H tests consists of low-fertile metallic fuel compositions and the AFC-1G test consists of non-fertile and low-fertile nitride compositions. These tests will be irradiated in the East Flux Trap (EFT) positions E1, E2, and E3, respectively, during Advanced Test Reactor (ATR) Cycle 135B.
A method for automatic identification of reliable heart rates calculated from ECG and PPG waveforms.
Yu, Chenggang; Liu, Zhenqiu; McKenna, Thomas; Reisner, Andrew T; Reifman, Jaques
2006-01-01
The development and application of data-driven decision-support systems for medical triage, diagnostics, and prognostics pose special requirements on physiologic data. In particular, that data are reliable in order to produce meaningful results. The authors describe a method that automatically estimates the reliability of reference heart rates (HRr) derived from electrocardiogram (ECG) waveforms and photoplethysmogram (PPG) waveforms recorded by vital-signs monitors. The reliability is quantitatively expressed through a quality index (QI) for each HRr. The proposed method estimates the reliability of heart rates from vital-signs monitors by (1) assessing the quality of the ECG and PPG waveforms, (2) separately computing heart rates from these waveforms, and (3) concisely combining this information into a QI that considers the physical redundancy of the signal sources and independence of heart rate calculations. The assessment of the waveforms is performed by a Support Vector Machine classifier and the independent computation of heart rate from the waveforms is performed by an adaptive peak identification technique, termed ADAPIT, which is designed to filter out motion-induced noise. The authors evaluated the method against 158 randomly selected data samples of trauma patients collected during helicopter transport, each sample consisting of 7-second ECG and PPG waveform segments and their associated HRr. They compared the results of the algorithm against manual analysis performed by human experts and found that in 92% of the cases, the algorithm either matches or is more conservative than the human's QI qualification. In the remaining 8% of the cases, the algorithm infers a less conservative QI, though in most cases this was because of algorithm/human disagreement over ambiguous waveform quality. If these ambiguous waveforms were relabeled, the misclassification rate would drop from 8% to 3%. This method provides a robust approach for automatically assessing the
Calculation of energy relaxation rates of fast particles by phonons in crystals
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.
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.
Sample size calculation for testing differences between cure rates with the optimal log-rank test.
Wu, Jianrong
2017-01-01
In this article, sample size calculations are developed for use when the main interest is in the differences between the cure rates of two groups. Following the work of Ewell and Ibrahim, the asymptotic distribution of the weighted log-rank test is derived under the local alternative. The optimal log-rank test under the proportional distributions alternative is discussed, and sample size formulas for the optimal and standard log-rank tests are derived. Simulation results show that the proposed formulas provide adequate sample size estimation for trial designs and that the optimal log-rank test is more efficient than the standard log-rank test, particularly when both cure rates and percentages of censoring are small.
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...
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 term...
Black Hole Production Rates at the LHC: Still Large
Rizzo, Thomas G.
2001-11-19
We examine the rates for the production of black holes(BH) at the LHC in light of the exponential suppression of the geometric cross section estimate proposed by Voloshin. We show that these rates will still be quite large over a reasonable range of model parameters. While BH production may not be the dominant process, its unique signature will ensure observability over conventional backgrounds.
Harbers, Jasper V; Huijbregts, Mark A J; Posthuma, Leo; Van de Meent, Dik
2006-03-01
Although many chemicals are in use, the environmental impacts of only a few have been established, usually on per-chemical basis. Uncertainty remains about the overall impact of chemicals. This paper estimates combined toxic pressure on coastal North Sea ecosystems from 343 high-production-volume chemicals used within the catchment of rivers Rhine, Meuse, and Scheldt. Multimedia fate modeling and species sensitivity distribution-based effects estimation are applied. Calculations start from production volumes and emission rates and use physicochemical substance properties and aquatic ecotoxicity data. Parameter uncertainty is addressed by Monte Carlo simulations. Results suggest that the procedure is technically feasible. Combined toxic pressure of all 343 chemicals in coastal North Seawater is 0.025 (2.5% of the species are exposed to concentration levels above EC50 values), with a wide confidence interval of nearly 0-1. This uncertainty appears to be largely due to uncertainties in interspecies variances of aquatic toxicities and, to a lesser extent, to uncertainties in emissions and degradation rates. Due to these uncertainties, the results support gross ranking of chemicals in categories: negligible and possibly relevant contributions only. With 95% confidence, 283 of the 343 chemicals (83%) contribute negligibly (less than 0.1%) to overall toxic pressure, and only 60 (17%) need further consideration.
Lin, Changyu; Djordjevic, Ivan B; Zou, Ding
2015-06-29
We propose a method to estimate the lower bound of achievable information rates (AIRs) of high speed orthogonal frequency-division multiplexing (OFDM) in spatial division multiplexing (SDM) optical long-haul transmission systems. The estimation of AIR is based on the forward recursion of multidimensional super-symbol efficient sliding-window Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. We consider most of the degradations of fiber links including nonlinear effects in few-mode fiber (FMF). This method does not consider the SDM as a simple multiplexer of independent data streams, but provides a super-symbol version for AIR calculation over spatial channels. This super-symbol version of AIR calculation algorithm, in principle, can be used for arbitrary multiple-input-multiple-output (MIMO)-SDM system with channel memory consideration. We illustrate this method by performing Monte Carlo simulations in a complete FMF model. Both channel model and algorithm for calculation of the AIRs are described in details. We also compare the AIRs results for QPSK/16QAM in both single mode fiber (SMF)- and FMF-based optical OFDM transmission.
Yang, Sandy; Yamamoto, Takeshi; Miller, William H.
2005-11-28
The quantum instanton approximation is a type of quantum transition state theory that calculates the chemical reaction rate using the reactive flux correlation function and its low order derivatives at time zero. Here we present several path-integral estimators for the latter quantities, which characterize the initial decay profile of the flux correlation function. As with the internal energy or heat capacity calculation, different estimators yield different variances (and therefore different convergence properties) in a Monte Carlo calculation. Here we obtain a virial(-type) estimator by using a coordinate scaling procedure rather than integration by parts, which allows more computational benefits. We also consider two different methods for treating the flux operator, i.e., local-path and global-path approaches, in which the latter achieves a smaller variance at the cost of using second-order potential derivatives. Numerical tests are performed for a one-dimensional Eckart barrier and a model proton transfer reaction in a polar solvent, which illustrates the reduced variance of the virial estimator over the corresponding thermodynamic estimator.
Stocking rate effects in a tilapia biofloc production system
USDA-ARS?s Scientific Manuscript database
Production efficiency is improved when the culture organism can grow rapidly to the desired target weight. Stocking rate is known to affect fish growth, but little information is available for tilapia grown in a biofloc technology (BFT) production system. The objective of this study was to quantify ...
Direct calculation of ice homogeneous nucleation rate for a molecular model of water
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
Direct calculation of ice homogeneous nucleation rate for a molecular model of water.
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.
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
A simple parameterization of ozone infrared absorption for atmospheric heating rate calculations
NASA Technical Reports Server (NTRS)
Rosenfield, Joan E.
1991-01-01
A simple parameterization of ozone absorption in the 9.6-micron region which is suitable for two- and three-dimensional stratospheric and tropospheric models is presented. The band is divided into two parts, a brand center region and a band wing region, grouping together regions for which the temperature dependence of absorption is similar. Each of the two regions is modeled with a function having the form of the Goody random model, with pressure and temperature dependent band parameters chosen by empirically fitting line-by-line equivalent widths for pressures between 0.25 and 1000 mbar and ozone absorber amounts between 1.0 x 10 to the -7th and 1.0 cm atm. The model has been applied to calculations of atmospheric heating rates using an absorber amount weighted mean pressure and temperature along the inhomogeneous paths necessary for flux computations. In the stratosphere, maximum errors in the heating rates relative to line-by-line calculations are 0.1 K/d, or 5 percent of the peak cooling at the stratopause. In the troposphere the errors are at most 0.005 K/d.
Comparison of measured and calculated dose rates near nuclear medicine patients.
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.
Rotation rate measurement and calculation for calcite crystals in a C-point mode
NASA Astrophysics Data System (ADS)
Herne, Catherine M.; O'Brien, Ann E.
2016-09-01
A polarization singularity mode offers a unique tool for actuating an array of birefringent calcite crystals, and measurement of the rotation rates of these crystals is in turn a way to image modes with varying polarization. In this work, we show the calculated and measured rotation rates of individual calcite crystals in a C-point mode and their dependence on three key factors: polarization, mode intensity profile, and crystal size. The C-point is a polarization singularity mode in which the mode has a circularly polarized center surrounded by elliptically polarized regions, with the orientation of the ellipse varying azimuthally and the degree of ellipticity changing radially. The beam is focused into an optical trapping region, and micron-sized birefringent calcite crystals in solution are positioned at key points in the mode. The crystals experience different torques at each location. The spin angular momentum of the light is proportional to the degree of ellipticity and to the intensity at each point in the mode. Our technique for generating C-point modes results in an intensity profile with a nonlinear radial dependence. Our crystal growth process generates crystals of varying width and thickness; the crystal size and shape affect the drag forces and light torque acting on them. We explain the crystal growth process and estimations of torque, demonstrate the rate and direction of rotation of calcite crystals placed at different points in the laser mode, and discuss the difference between the estimated and measured rotation rates.
Production rates and costs of cable yarding wood residue from clearcut units
Chris B. LeDoux
1984-01-01
Wood residue is a little used source of fiber, chips, and fuel because harvest costs are largely unknown. This study calculates incremental production rates and costs for yarding and loading logging residue in clearcut old-growth Douglas-fir/western hemlock forests. Harvest operations were observed for two timber sales in western Oregon. Three different cable yarding...
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.
NASA Astrophysics Data System (ADS)
Ahamed, A.; Snyder, N. P.; David, G. C.
2014-12-01
The Reservoir Sedimentation Database (ResSed), a catalogue of reservoirs and depositional data that has recently become publically available, allows for rapid calculation of sedimentation rates and rates of capacity loss over short (annual to decadal) timescales. This study is a statistical investigation of factors controlling watershed average erosion rates (E) in eastern United States watersheds. We develop an ArcGIS-based model that delineates watersheds upstream of ResSed dams and calculate drainage areas to determine E for 191 eastern US watersheds. Geomorphic, geologic, regional, climatic, and land use variables are quantified within study watersheds using GIS. Erosion rates exhibit a large amount of scatter, ranging from 0.001 to 1.25 mm/yr. A weak inverse power law relationship between drainage area (A) and E (R2 = 0.09) is evident, similar to other studies (e.g. Milliman and Syvitski, 1992; Koppes and Montgomery, 2009). Linear regressions reveal no relationship between mean watershed slope (S) and E, possibly due to the relatively low relief of the region (mean S for all watersheds is 6°). Analysis of Variance shows that watersheds in formerly glaciated regions exhibit a statistically significant lower mean E (0.06 mm/year) than watersheds in unglaciated regions (0.12 mm/year), but that watersheds with different dam purposes show no significant differences in mean E. Linear regressions reveal no relationships between E and land use parameters like percent agricultural land and percent impervious surfaces (I), but classification and regression trees indicate that watersheds in highly developed regions (I > 34%) exhibit mean E (0.36 mm/year) that is four times higher than watersheds in less developed (I < 34%) regions (0.09 mm/year). Further, interactions between land use variables emerge in formerly glaciated regions, where increased agricultural land results in higher rates of annual capacity loss in reservoirs (R2 = 0.56). Plots of E versus timescale of
Cosmic-ray-produced stable nuclides: various production rates and their implications
Reedy, R.C.
1981-06-15
The rates for a number of reactions producing certain stable nuclides, such as /sup 3/He and /sup 4/He, and fission in the moon are calculated for galactic-cosmic-ray particles and for solar protons. Solar-proton-induced reactions with bromine usually are not an important source of cosmogenic Kr isotopes. The /sup 130/Ba(n,p) reaction cannot account for the undercalculation of /sup 130/Xe production rates. Calculated production rates of /sup 15/N, /sup 13/C, and /sup 2/H agree fairly well with rates inferred from measured excesses of these isotopes in samples with long exposure ages. Cosmic-ray-induced fission of U and Th can produce significant amounts of fission tracks and of /sup 86/Kr, /sup 134/Xe, and /sup 136/Xe, especially in samples with long exposures to cosmic-ray particles.
Voxel modeling of rabbits for use in radiological dose rate calculations.
Caffrey, E A; Johansen, M P; Higley, K A
2016-01-01
Radiation dose to biota is generally calculated using Monte Carlo simulations of whole body ellipsoids with homogeneously distributed radioactivity throughout. More complex anatomical phantoms, termed voxel phantoms, have been developed to test the validity of these simplistic geometric models. In most voxel models created to date, human tissue composition and density values have been used in lieu of biologically accurate values for non-human biota. This has raised questions regarding variable tissue composition and density effects on the fraction of radioactive emission energy absorbed within tissues (e.g. the absorbed fraction - AF), along with implications for age-dependent dose rates as organisms mature. The results of this study on rabbits indicates that the variation in composition between two mammalian tissue types (e.g. human vs rabbit bones) made little difference in self-AF (SAF) values (within 5% over most energy ranges). However, variable tissue density (e.g. bone vs liver) can significantly impact SAF values. An examination of differences across life-stages revealed increasing SAF with testis and ovary size of over an order of magnitude for photons and several factors for electrons, indicating the potential for increasing dose rates to these sensitive organs as animals mature. AFs for electron energies of 0.1, 0.2, 0.4, 0.5, 0.7, 1.0, 1.5, 2.0, and 4.0 MeV and photon energies of 0.01, 0.015, 0.02, 0.03, 0.05, 0.1, 0.2, 0.5, 1.0, 1.5, 2.0, and 4.0 MeV are provided for eleven rabbit tissues. The data presented in this study can be used to calculate accurate organ dose rates for rabbits and other small rodents; to aide in extending dose results among different mammal species; and to validate the use of ellipsoidal models for regulatory purposes.
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...
NASA Technical Reports Server (NTRS)
Gokoglu, S. A.; Chen, B. K.; Rosner, D. E.
1984-01-01
The computer program based on multicomponent chemically frozen boundary layer (CFBL) theory for calculating vapor and/or small particle deposition rates is documented. A specific application to perimter-averaged Na2SO4 deposition rate calculations on a cylindrical collector is demonstrated. The manual includes a typical program input and output for users.
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
Dose Rate Calculations of Spent MTR-HEU Fuel Elements of the IAN-R1 Research Reactor
NASA Astrophysics Data System (ADS)
Sarta Fuentes, Jose Antonio
2005-04-01
With cooperation of the International Atomic Energy Agency (IAEA) and the Department of Energy (DOE) of the United States, several tasks related to the waste disposal of spent MTR fuel enriched nominally to 93% were carried out for the conversion of the IAN-R1 Research Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to remove the spent MTR-HEU fuel of the core and store it safetly, a program was established at the Instituto de Ciencias Nucleares y Energìas Alternativas (INEA). This program included training, acquisition of hardware and sofware, design and construction of a decay pool, transfer of the spent HEU fuel elements into the decay pool and his final transport to Savanah River in United States. In this paper are presented external dose rates which were calculated for a standard spent MTR-HEU fuel element of the IAN-R1 Research Reactor. The calculations take in consideration the activity due to contributions of fission, activation and actinides products for each relevant radionuclide present in a standard spent MTR-HEU fuel. The datas obtained were the base for the respective dosimetric evaluations in the transfering operations of fuel elements into the decay pool and for shielding calculations in designing of the decay pool.
Mapping {sup 15}O Production Rate for Proton Therapy Verification
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.
Mapping (15)O production rate for proton therapy verification.
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
This work was a proof-of-principle study for the evaluation of oxygen-15 ((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. 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 (15)O production and clearance rates, which were compared to live versus dead rates for the rabbit and to Monte Carlo predictions. 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 (15)O production rates agreed with the expected ratio. In the dead rabbit thighs, the dynamic PET concentration histories were accurately described using (15)O decay constant, whereas the live thigh activity decayed faster. Most importantly, the (15)O production rates agreed within 2% (P>.5) between conditions. We developed a new method for quantitative measurement of (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 (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, (15)O clearance rates may be useful in monitoring permeability changes due to therapy. Copyright © 2015 Elsevier Inc. All rights reserved.
Helium release rates and ODH calculations from RHIC magnet cooling line failure
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.
A precise calculation of delayed coincidence selection efficiency and accidental coincidence rate
NASA Astrophysics Data System (ADS)
Yu, Jing-Yi; Wang, Zhe; Chen, Shao-Min
2015-05-01
A precise background evaluation model is proposed to address the complex data structure of the delayed coincidence method, which is widely used in reactor electron-antineutrino oscillation experiments. In this model, effects from the muon veto, uncorrelated random background, and background are all studied analytically, simplifying the estimation of the systematic uncertainties of signal efficiency and accidental background rate. The results of the calculations are validated numerically with a number of simulation studies and also applied and validated in the recent Daya Bay hydrogen-capture based oscillation measurement. Supported by Ministry of Science and Technology of China (2013CB834302), National Natural Science Foundation of China (11235006, 11475093), Tsinghua University Initiative Scientific Research Program (2012Z02161), and Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education.
Healing rate calculation in the diabetic foot ulcer: comparing different methods.
Santamaria, Nick; Ogce, Filiz; Gorelik, Alexandra
2012-01-01
The determination of healing rate in the diabetic foot wound is an important assessment parameter that is part of the overall clinical decision-making process in wound treatment. A number of methods that have been used to calculate healing, ranging from length and width measurement, surface area measure changes expressed as a function of time and linear advancement of the wound edge. The objective of this study was to compare surface area measures to linear advancement of the wound edge in 228 diabetic foot ulcers. Each wound was measured using the two methods and analyzed using linear regression to determine the best modeling of the healing process in these wounds. Results indicated that the total surface area change per day was superior to the linear advancement parameter in this group of wounds and that the area measurement was significantly more likely to predict the healing trajectory in the subgroup of wounds that took more than 28 days to heal. Contrary to expectations, the linear advancement method was correlated to initial wound size in the longer duration wounds suggesting that in these chronic wounds, differing healing phases render the surface area calculation method superior to the linear advancement parameter. © 2012 by the Wound Healing Society.
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.
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).
Oxygen transfer and uptake rates during xanthan gum production.
García-Ochoa; Castro; Santos
2000-11-15
Oxygen uptake rate and oxygen mass transfer rate have been studied during xanthan gum production process in stirred tank bioreactor. Empirical equations for the oxygen mass transfer coefficient have been obtained taking into account several variables such as air flow rate, stirrer speed and apparent viscosity. Oxygen uptake rate evolution in the course fermentation has been measured, obtaining an equation as a function of biomass concentration, including overall growth and non growth-associated oxygen uptake. A metabolic kinetic model has been employed for xanthan gum production description including oxygen mass transfer and uptake rates. The results point out that this model is able to describe adequately not only oxygen dissolved evolution, but also of the production of xanthan and substrate consumption. Also, the influence of several parameters (k(L)a, air flow rate and dissolved oxygen) in the evolution of the key compounds of the system have been studied. The results of the simulation shown that an increasing of dissolved oxygen concentration favor the xanthan gum production.
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. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Xu, Z; Chen, C; Shen, J
1998-05-01
It has much more advantage to use the cylindric ultraviolet air washer than to use the ordinary ultraviolet lamps. There was a calculation method for determining necessary lamps in a rectangled ultraviolet air washer, but it had a limiting condition. This paper developed two calculating methods for determining necessary lamps and its sterile rate in a tube-shaped ultraviolet air washer. The sterile rate can be extracted with any parameter. Necessary lamps can also be extracted with its sterile rate.
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.
Enhanced sophorolipid production by feeding-rate-controlled fed-batch culture.
Kim, Young-Bum; Yun, Hyun Shik; Kim, Eun-Ki
2009-12-01
To develop the easier control method for fed-batch culture of sophorolipid production, we chose rapeseed oil as the most productive oil and compared their productivities in relation to different concentrations of glucose. The optimal concentration of glucose was 30 g/L for sophorolipid production. A fed-batch method was conducted using Candida bombicola ATCC 22214 with rapeseed oil as a secondary substrate. The feeding rate of rapeseed oil was dependent on pH and was calculated by the consumption rate of NaOH and rapeseed oil. The glucose concentration was constantly maintained between 30 and 40 g/L. As a result, we have produced a crude sophorolipid up to 365 g/L for 8 days through a feeding-rate-controlled fed-batch process.
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).
Growth rate calculations of auroral kilometric radiation using the relativistic resonance condition
NASA Technical Reports Server (NTRS)
Omidi, N.; Gurnett, D. A.
1982-01-01
The relativistic cyclotron resonance condition for right-handed extraordinary mode waves defines an ellipse in velocity space. The position of the center and size of the semiminor axis of this ellipse are functions of the plasma frequency, gyrofrequency, wave frequency, and wave normal angle. The effect of varying these parameters on the position and size of the resonance contour is analyzed. The results show that as the wave normal angle decreases, the semiminor axis increases in size and as the plasma frequency to gyrofrequency ratio decreases, the minimum energy for resonating electrons decreases and the maximum wave normal angle allowed by the resonance condition increases. Also, as the wave frequency to gyrofrequency ratio increases, the center of the resonance ellipse moves away from the origin. The relativistic resonance condition and the electron distribution in velocity space obtained by the S3-3 satellite are used to calculate numerically growth rates for the terrestrial auroral kilometric radiation. It is shown that the loss cone region of the electron distribution can give rise to growth rates for the extraordinary mode that are sufficiently large to account for the observed radio emission intensities.
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).
Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations
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
Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations
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
Refinement of the Air Force Systems Command Production Rate Model
1989-09-01
the recommended modified formulations. The relationship between production rate and production ratio has a definite influence on the model’s ability to...1984 7 36 21.954 370.00 1985 8 48 21.017 412.00 A- 3 Table A.2.8 F-15E Cost/Quantity Data Fiscal Year Lot Quntit Recurring Unit Cost LPP 1986 1 60
Cosmogenic Chlorine-36 Global Production Rate Parameter Calibration
NASA Astrophysics Data System (ADS)
Marrero, S.; Borchers, B.; Phillips, F. M.; Aumer, R.; Stone, J.
2010-12-01
As part of the CRONUS-Earth project, geological calibrations of in-situ production rates of cosmogenic nuclides, including chlorine-36, are being conducted as part of a larger project to improve the accuracy of techniques employing cosmogenic nuclides. Previous chlorine-36 production rate calibrations have been particularly difficult, likely due to the multiple production pathways. We are performing a step-wise calibration in order to specifically address the uncertainties and problems in previous studies. The low-energy neutrons will be constrained first using a depth profile analysis and then the spallation rates will be calibrated using surface and depth profile samples from five additional sites. This study will produce production rate parameters for each of the main spallation reactions (K, Ca) as well as the production by low-energy neutrons from Cl. Muons are based on Heisinger, 2002 and are not calibrated in this study. The geological calibration locations include the Peruvian Andes; Lake Bonneville, UT; Isle of Skye, Scotland; Hawaii; Dry Valleys of Antactica; and Copper Canyon, NM.
NASA Astrophysics Data System (ADS)
Horowitz, Arthur J.
2003-12-01
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 (<1 000 000 to >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 <+/-20%) annual suspended sediment fluxes can be obtained from hydrologically based monthly measurements/samples. For 5-year periods or longer, similar results can be obtained from measurements/samples collected once every 2 months. In either case, hydrologically based sampling, as opposed to calendar-based sampling is likely to limit the magnitude of
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).
Wastewater treatment high rate algal ponds for biofuel production.
Park, J B K; Craggs, R J; Shilton, A N
2011-01-01
While research and development of algal biofuels are currently receiving much interest and funding, they are still not commercially viable at today's fossil fuel prices. However, a niche opportunity may exist where algae are grown as a by-product of high rate algal ponds (HRAPs) operated for wastewater treatment. In addition to significantly better economics, algal biofuel production from wastewater treatment HRAPs has a much smaller environmental footprint compared to commercial algal production HRAPs which consume freshwater and fertilisers. In this paper the critical parameters that limit algal cultivation, production and harvest are reviewed and practical options that may enhance the net harvestable algal production from wastewater treatment HRAPs including CO(2) addition, species control, control of grazers and parasites and bioflocculation are discussed.
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.
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.
RADIOLYTIC GAS PRODUCTION RATES OF POLYMERS EXPOSED TO TRITIUM GAS
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.
Rogers, G; Oosthuyse, T
2000-02-01
The standard equation used to calculate mean arterial pressure (MAP) assumes that diastole persists for 2/3 and systole for 1/3 of each cardiac cycle. This ratio is altered when heart rate increases, and therefore we investigated the efficacy of predicting MAP during exercise using non-invasive indirect methods. Eight subjects exercised on a cycle ergometer for 3 minute intervals to elicit heart rates between 100-110, 120-130, 140-150, 160-170, and 180-190 beats/min. In the last minute of each 3 min interval an ECG recording was taken and systolic (SP) and diastolic (DP) blood pressure was measured by manual auscultation. MAP was calculated for each heart rate interval by: MAP=DP+1/3(SP-DP) (method A), and MAP= DP + Fs(SP- DP) (method B), where Fs is the fraction of the cardiac cycle comprising systole, measured from the ECG. Fs increased from 0.35+/-0.049 at rest to 0.47+/-0.039 at a heart rate of 180-190 beats/min. MAP measured by method B was consistently greater than MAP calculated by method A at all heart rates greater than resting heart rate (p<0.01). The error incurred when using the standard MAP equation (method A) to derive MAP during exercise (measured as the percentage difference between method A and B) increased linearly with heart rate (r=0.98). The standard MAP equation should not be applied during exercise, as it does not account for the change in the systolic: diastolic period ratio as heart rate increases.
MEASURED AND CALCULATED HEATING AND DOSE RATES FOR THE HFIR HB4 BEAM TUBE AND COLD SOURCE
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.
NASA Astrophysics Data System (ADS)
Ruslan, Siti Zaharah Mohd; Jaffar, Maheran Mohd
2017-05-01
Islamic banking in Malaysia offers variety of products based on Islamic principles. One of the concepts is a diminishing musyarakah. The concept of diminishing musyarakah helps Muslims to avoid transaction which are based on riba. The diminishing musyarakah can be defined as an agreement between capital provider and entrepreneurs that enable entrepreneurs to buy equity in instalments where profits and losses are shared based on agreed ratio. The objective of this paper is to determine the internal rate of return (IRR) for a diminishing musyarakah model by applying a numerical method. There are several numerical methods in calculating the IRR such as by using an interpolation method and a trial and error method by using Microsoft Office Excel. In this paper we use a bisection method and secant method as an alternative way in calculating the IRR. It was found that the diminishing musyarakah model can be adapted in managing the performance of joint venture investments. Therefore, this paper will encourage more companies to use the concept of joint venture in managing their investments performance.
[Morbidity rate among Georgian sodium cyanide production workers].
Kverenchkhiladze, G
2005-09-01
With the purpose of evaluation of the role of production-professional factors on the health status of sodium cyanide production workers, the working conditions (pollution of the air by chemical substances, microclimate, noise, vibration) were examined and the data on temporary work incapacity during 2000-2004 years were analyzed. Among the production-professional factors the pollution of the air of working surroundings by toxic substances, as well as the high temperature of air, noise and vibration were leading causes. It is shown that the working conditions have certain influence on the morbidity rate among the workers. Morbidity rate in the main group was 1,7 times higher. In the morbidity structure, diseases of respiratory, cardio-vascular, nervous, digestive and musculoskeletal systems were leading.
Drill-in fluid reduces formation damage, increases production rates
Hands, N.; Kowbel, K.; Nouris, R.
1998-07-13
A sodium formate drill-in fluid system reduced formation damage, resulting in better-than-expected production rates for an off-shore Dutch development well. Programmed to optimize production capacity and reservoir drainage from a Rotliegend sandstone gas discovery, the 5-7/8-in. subhorizontal production interval was drilled and completed barefoot with a unique, rheologically engineered sodium formate drill-in fluid system. The new system, consisting of a sodium formate (NaCOOH) brine as the base fluid and properly sized calcium carbonate as the formation-bridging agent, was selected on the basis of its well-documented record in reducing solids impairment and formation damage in similar sandstone structures in Germany. The system was engineered around the low-shear-rate viscosity (LSRV) concept, designed to provide exceptional rheological properties. After describing the drilling program, the paper gives results on the drilling and completion.
A model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides
NASA Astrophysics Data System (ADS)
Reedy, R. C.
1985-02-01
A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions and energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g/cm (2). Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurments of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth.
Model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides
Reedy, R.C.
1984-01-01
A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions of energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g cm/sup -2/. Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurements of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth. 25 references, 8 figures.
39 CFR 3010.23 - Calculation of percentage change in rates.
Code of Federal Regulations, 2014 CFR
2014-07-01
... as the introduction, deletion, or redefinition of rate cells. Whenever possible, adjustments shall be... rate means the rate in effect when the Postal Service files the notice of rate adjustment. (ii... files the notice of rate adjustment. (iii) Exception. When used with respect to a rate cell that...
Buenker, Robert J; Liebermann, Heinz-Peter
2009-09-21
Ab initio multireference single- and double-excitation configuration interaction calculations have been carried out to compute the potential curves and annihilation rates (ARs) of positronic molecular complexes of a series of alkali monoxides. The dissociation limit for the lowest states of these systems consists of the positive alkali ion ground state (M(+)) and the OPs (e(+)O(-)) complex formed by attaching the positron to O(-), even though the ground state of the corresponding neutral molecule always correlates with uncharged fragments (M+O). The positron affinity of the neutral oxide (2)Pi state is greater than that of (2)Sigma(+) in each case, so that the e(+)MO ground state always has (3,1)Pi symmetry, despite the fact that both KO and RbO have (2)Sigma(+) ground states. The bonding in the positronic systems is highly ionic at all internuclear distances and this causes their ARs to decrease gradually as the positive alkali ion approaches the OPs fragment.
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.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 2 2010-10-01 2010-10-01 false Methodology for calculating the per-treatment base... Disease (ESRD) Services and Organ Procurement Costs § 413.220 Methodology for calculating the per.... The methodology for determining the per treatment base rate under the ESRD prospective payment...
THE PRODUCTION RATE OF SN Ia EVENTS IN GLOBULAR CLUSTERS
Washabaugh, Pearce C.; Bregman, Joel N. E-mail: jbregman@umich.edu
2013-01-01
In globular clusters, dynamical evolution produces luminous X-ray emitting binaries at a rate about 200 times greater than in the field. If globular clusters also produce SN Ia at a high rate, it would account for many of the SN Ia production in early-type galaxies and provide insight into their formation. Here we use archival Hubble Space Telescope (HST) images of nearby galaxies that have hosted an SN Ia to examine the rate at which globular clusters produce these events. The location of the SN Ia is registered on an HST image obtained before the event or after the supernova (SN) faded. Of the 36 nearby galaxies examined, 21 had sufficiently good data to search for globular cluster hosts. None of the 21 SNe have a definite globular cluster counterpart, although there are some ambiguous cases. This places an upper limit to the enhancement rate of SN Ia production in globular clusters of about 42 at the 95% confidence level, which is an order of magnitude lower than the enhancement rate for luminous X-ray binaries. Even if all of the ambiguous cases are considered as having a globular cluster counterpart, the upper bound for the enhancement rate is 82 at the 95% confidence level, still a factor of several below that needed to account for half of the SN Ia events. Barring unforeseen selection effects, we conclude that globular clusters are not responsible for producing a significant fraction of the SN Ia events in early-type galaxies.
Measurements of Diel Rates of Bacterial Secondary Production in Aquatic Environments †
Riemann, Bo; Søndergaard, Morten
1984-01-01
Measurements of bacterial secondary production were carried out during 13 diel studies at one coastal marine station and in five lakes differing with respect to nutrient concentration and primary production. Bacterial secondary production was measured in situ every 3 to 5 h by [3H]thymidine incorporation into DNA. In some of the diel studies, these results were compared with results obtained from dark 14CO2 uptake and frequency of dividing cells. Only minor diel changes were observed. The rate of [3H]thymidine incorporation into DNA and the frequency of dividing cells varied from 23 to 194% of the diel mean. The dark CO2 uptake rate varied from 12 to 259% of the diel mean. An analysis of variance demonstrated that no specific time periods during 24 h showed significantly different production rates, supporting the idea that bacterial activities in natural assemblages are controlled by a variety of events. The best correction (r2 = 0.74) was obtained between the [3H]thymidine incorporation and frequency of dividing cells procedures from the lake water samples. The actual production rates calculated by [3H]thymidine incorporation into DNA were appreciably lower than those obtained by the frequency of dividing cells and the dark CO2 uptake techniques. Diel rates of bacterial production are discussed in relation to sampling frequency, statistical errors, and choice of method. PMID:16346505
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.
Light dose versus rate of delivery: implications for macroalgal productivity.
Desmond, Matthew J; Pritchard, Daniel W; Hepburn, Christopher D
2017-04-07
The role of how light is delivered over time is an area of macroalgal photosynthesis that has been overlooked but may play a significant role in controlling rates of productivity and the structure and persistence of communities. Here we present data that quantify the relative influence of total quantum dose and delivery rate on the photosynthetic productivity of five ecologically important Phaeophyceae species from southern New Zealand. Results suggested that greater net oxygen production occurs when light is delivered at a lower photon flux density (PFD) over a longer period compared to a greater PFD over a shorter period, given the same total dose. This was due to greater efficiency (α) at a lower PFD which, for some species, meant a compensatory effect can occur. This resulted in equal or greater productivity even when the total quantum dose of the lower PFD was significantly reduced. It was also shown that light limitation at Huriawa Peninsula, where macroaglae were sourced, may be restricting the acclimation potential of species at greater depths, and that even at shallow depth periods of significant light limitation are likely to occur. This research is of particular interest as the variability of light delivery to coastal reef systems increases as a result of anthropogenic disturbances, and as the value of in situ community primary productivity estimates is recognised.
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.
Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V
2015-09-07
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.
NASA Astrophysics Data System (ADS)
Duchemin, C.; Guertin, A.; Haddad, F.; Michel, N.; Métivier, V.
2015-09-01
HIGHLIGHTS • Production of Sc-44m, Sc-44g 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-44g or the metastable-state Sc-44m 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-44m and Sc-44g are calculated and compared with those for the proton route for three different scenarios: the production of Sc-44g for conventional PET imaging, its production for the new 3 γ imaging technique developed at the SUBATECH laboratory and the production of a Sc-44m/Sc-44g in vivo generator for antibody labelling.
Local Entropy Production Rates in a Polymer Electrolyte Membrane Fuel Cell
NASA Astrophysics Data System (ADS)
Siemer, Marc; Marquardt, Tobias; Valadez Huerta, Gerardo; Kabelac, Stephan
2017-01-01
A modeling study on a polymer electrolyte membrane fuel cell by means of non-equilibrium thermodynamics is presented. The developed model considers a one-dimensional cell in steady-state operation. The temperature, concentration and electric potential profiles are calculated for every domain of the cell. While the gas diffusion and the catalyst layers are calculated with established classical modeling approaches, the transport processes in the membrane are calculated with the phenomenological equations as dictated by the non-equilibrium thermodynamics. This approach is especially instructive for the membrane as the coupled transport mechanisms are dominant. The needed phenomenological coefficients are approximated on the base of conventional transport coefficients. Knowing the fluxes and their intrinsic corresponding forces, the local entropy production rate is calculated. Accordingly, the different loss mechanisms can be detected and quantified, which is important for cell and stack optimization.
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.
NASA Astrophysics Data System (ADS)
Sramek, O.; McDonough, W. F.; Mukhopadhyay, S.; Stevens, L.; Siegel, J.
2013-12-01
While atmospheric concentration of some noble gas nuclides is controlled by their cosmogenic production (e.g., 39Ar), nucleonic production dominates in subsurface environments. Nucleogenic production rates, which involve alpha-induced reactions, depend on Th and U abundances in the source rock. Production rates of 39Ar and 40Ar scale with K abundance in the source. Consequently, observed isotopic ratio of noble gas in crustal fluids and mantle-derived lavas can be compared to calculated predictions in order to constrain heat producing element abundances in the source rock. In particular, 39Ar/40Ar, 39Ar/21Ne, and 40Ar/21Ne inform us about U+Th abundance, K abundance, and K/U ratio. We calculate subsurface production rates for these nuclides for various assumed rock compositions. A discrepancy in existing evaluations of 39Ar production rates is noted. While Mei et al. (2010) predict a production rate of 5 atoms of 39Ar per kg per year for a K=2 %, Th=5 ppm, U=2 ppm (by weight) rock, Yokochi et al. (2012) evaluate 39Ar production rate, in number of atoms / (kg yr), at 24, and Yokochi et al. (2013) results range between 50-80. Efforts are underway to understand these differences. Experimental methods of 39Ar counting have advanced significantly in recent years, a development driven to large extent by the needs of experimental particle physics community in their search for dark matter using argon-based WIMP detectors. Measurement techniques now allow determination of 39Ar/40Ar ratios in crustal rocks and are approaching the detectability of 39Ar/40Ar ratio predicted for a mantle source. We discuss how the noble gas ratio measurements can be harnessed to gain insight into source rock's abundances of heat producing elements including mantle K/U ratio. Mei, D.-M. et al., 2010. Phys. Rev. C 81, 055802, doi:10.1103/PhysRevC.81.055802 Yokochi, R. et al., 2012. Geochim. Cosmochim. Acta 88, 19-26, doi:10.1016/j.gca.2012.04.034 Yokochi, R. et al., 2013. Chem. Geol. 339, 43
Developing ratings for food products: lessons learned from media rating systems.
Kunkel, Dale; McKinley, Christopher
2007-01-01
Children regularly consume low-nutrient, high-calorie food that is not consistent with a healthful diet, contributing to an increasing epidemic of overweight and obesity. Among the multiple causes of this problem is the food industry's emphasis on marketing calorie-dense food products to children. The Institute of Medicine (IOM) has recommended that industry adopt a uniform system of simplified food ratings to convey the nutritional qualities of food in a manner that is understandable and appealing to children and youth. This report analyzes the need for such a system in a food marketing environment that increasingly identifies healthful products for the consumer in inconsistent fashion. It considers evidence regarding current usage of food labeling and draws parallels with media rating systems in discussing the prospects for a uniform food rating system that would accomplish the IOM's objective.
Entropy production rate as a constraint for collisionless fluid closures
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.
Entropy production rate as a constraint for collisionless fluid closures
NASA Astrophysics Data System (ADS)
Fleurence, E.; Sarazin, Y.; Garbet, X.; Dif-Pradalier, G.; Ghendrih, Ph.; Grandgirard, V.; Ottaviani, M.
2006-11-01
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.
Dunn, Jennifer B.; Qin, Zhangcai; Mueller, Steffen; Kwon, Ho-young; Wander, Michelle M.; Wang, Michael
2016-09-01
The $\\underline{C}$arbon $\\underline{C}$alculator for $\\underline{L}$and $\\underline{U}$se Change from $\\underline{B}$iofuels 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.
Zhang, Xiao-jun; Rodriguez, Noe A.; Wang, Lijian; Tuvdendorj, Demidmaa; Wu, Zhanpin; Tan, Alai; Herndon, David N.; Wolfe, Robert R.
2012-01-01
Our goal was to assess the validity of the enrichments of plasma free palmitate and intramuscular (IM) fatty acid metabolites as precursors for calculating the IM triglyceride fractional synthetic rate. We infused U-13C16-palmitate in anesthetized rabbits for 3 h and sampled adductor muscle of legs using both freeze-cut and cut-freeze approaches. We found that IM free palmitate enrichment (0.70 ± 0.07%) was lower (P < 0.0001) than IM palmitoyl-CoA enrichment (2.13 ± 0.17%) in samples taken by the freeze-cut approach. The latter was close (P = 0.33) to IM palmitoyl-carnitine enrichment (2.42 ± 0.16%). The same results were obtained from the muscle samples taken by the cut-freeze approach, except the enrichment of palmitoyl-CoA (2.21 ± 0.08%) was lower (P = 0.02) than that of palmitoyl-carnitine (2.77 ± 0.17%). Plasma free palmitate enrichment was ∼2-fold that of IM palmitoyl-CoA enrichment and palmitoyl-carnitine enrichment (P < 0.001). These findings indicate that plasma free palmitate overestimated IM precursor enrichment owing to in vivo IM lipid breakdown, whereas IM free palmitate enrichment underestimated the precursor enrichment because of lipid breakdown during muscle sampling and processing. IM palmitoyl-carnitine enrichment was an acceptable surrogate of the precursor enrichment because it was less affected by in vitro lipid breakdown after sampling. PMID:21934122
The global-average production rate of Be-10
NASA Astrophysics Data System (ADS)
Monaghan, M. C.; Krishnaswami, S.; Turekian, K. K.
1986-01-01
Precipitation collected in continuously open containers for about a year at seven sites around the United States was analyzed for Be-10, Sr-90, Pb-210, and U-238. Based on these data and long-term precipitation, Sr-90 and Pb-210 delivery patterns, the stratospheric, tropospheric and recycled Be-10 components in the collections were estimated and the global Be-10 production rate was assessed. Single station production rate estimates range from 0.52 x 10 to the 6th to 2.64 x 10 to the 6th atoms/sq cm per year. The mean value is 1.21 x 10 to the 6th atoms/sq cm per year with a standard error of 0.26 x 10 to he 6th atoms/per year
USDA-ARS?s Scientific Manuscript database
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...
MO-D-213-07: RadShield: Semi- Automated Calculation of Air Kerma Rate and Barrier Thickness
DeLorenzo, M; Wu, D; Rutel, I; Yang, K
2015-06-15
Purpose: To develop the first Java-based semi-automated calculation program intended to aid professional radiation shielding design. Air-kerma rate and barrier thickness calculations are performed by implementing NCRP Report 147 formalism into a Graphical User Interface (GUI). The ultimate aim of this newly created software package is to reduce errors and improve radiographic and fluoroscopic room designs over manual approaches. Methods: Floor plans are first imported as images into the RadShield software program. These plans serve as templates for drawing barriers, occupied regions and x-ray tube locations. We have implemented sub-GUIs that allow the specification in regions and equipment for occupancy factors, design goals, number of patients, primary beam directions, source-to-patient distances and workload distributions. Once the user enters the above parameters, the program automatically calculates air-kerma rate at sampled points beyond all barriers. For each sample point, a corresponding minimum barrier thickness is calculated to meet the design goal. RadShield allows control over preshielding, sample point location and material types. Results: A functional GUI package was developed and tested. Examination of sample walls and source distributions yields a maximum percent difference of less than 0.1% between hand-calculated air-kerma rates and RadShield. Conclusion: The initial results demonstrated that RadShield calculates air-kerma rates and required barrier thicknesses with reliable accuracy and can be used to make radiation shielding design more efficient and accurate. This newly developed approach differs from conventional calculation methods in that it finds air-kerma rates and thickness requirements for many points outside the barriers, stores the information and selects the largest value needed to comply with NCRP Report 147 design goals. Floor plans, parameters, designs and reports can be saved and accessed later for modification and recalculation
Measurements of in situ chemical ozone (oxidant) production rates
NASA Astrophysics Data System (ADS)
Huang, Hao; Faloon, Kate; Najera, Juan; Bloss, William
2013-04-01
Tropospheric ozone is a major air pollutant, harmful to human health, agricultural crops and vegetation, the main precursor to the atmospheric oxidants which initiate the degradation of most reactive gases emitted to the atmosphere, and an important greenhouse gas in its own right. The capacity to understand and predict tropospheric ozone levels is a key goal for atmospheric science - but one which is challenging, as ozone is formed in the atmosphere from the complex oxidation of VOCs in the presence of NOx and sunlight, on a timescale such that in situ chemical processes, deposition and transport all affect ozone levels. Known uncertainties in emissions, chemistry, dynamics and deposition affect the accuracy of predictions of current and future ozone levels, and hinder development of optimal air quality policies to mitigate against ozone exposure. Recently new approaches to directly measure the local chemical ozone production rate, bypassing the many uncertainties in emissions and chemical schemes, have been developed (Cazorla & Brune, AMT 2010). Here, we describe the development of an analogous Ozone Production Rate (OPR) approach: Air is sampled into parallel reactors, within which ozone formation either occurs as in the ambient atmosphere, or is suppressed. Comparisons of ozone levels exiting a pair of such reactors determines the net chemical oxidant production rate, after correction for perturbation of the NOx-O3 photochemical steady state, and when operated under conditions such that wall effects are minimised. We report preliminary measurements of local chemical ozone production made during the UK NERC ClearfLo (Clean Air for London) campaign at an urban background location in London in January and July 2012. The OPR system was used to measure the local chemical oxidant formation rate, which is compared with observed trends in O3 and NOx and the prevailing meteorology, and with the predictions of a detailed zero-dimensional atmospheric chemistry model
USDA-ARS?s Scientific Manuscript database
Determination of absolute configuration (AC) is one of the most challenging features in the structure elucidation of chiral natural products, especially those with complex structures. With revolutionary advancements in the area of quantum chemical calculations of chiroptical spectroscopy over the pa...
37 CFR 1.778 - Calculation of patent term extension for an animal drug product.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Calculation of patent term extension for an animal drug product. 1.778 Section 1.778 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment and Extension of Patent Term Extension...
37 CFR 1.779 - Calculation of patent term extension for a veterinary biological product.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Calculation of patent term extension for a veterinary biological product. 1.779 Section 1.779 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Adjustment and Extension of Patent Term...
Eric van Steenis
2013-01-01
This paper illustrates how to use an excel spreadsheet as a decision-making tool to determine optimum sowing factor to minimize seedling production cost. Factors incorporated into the spreadsheet calculations include germination percentage, seeder accuracy, cost per seed, cavities per block, costs of handling, thinning, and transplanting labor, and more. In addition to...
NASA Astrophysics Data System (ADS)
Rüstemoǧlu, Sevinç; Barutçu, Burak; Sibel Menteş, Å..
2010-05-01
The continuous usage of fossil fuels as primary energy source is the reason of the emission of CO and powerless economy of the country affected by the great flactuations in the unit price of energy sources. In recent years, developments in wind energy sector and the supporting new renewable energy policies of the countries allow the new wind farm owners and the firms who expect to be an owner to consider and invest on the renewable sources. In this study, the annual production of the turbines with 1.8 kW and 30 kW which are available for Istanbul Technical University in Energy Institute is calculated by Wasp and WindPro Field Flow Models and the wind characteristics of the area are analysed. The meteorological data used in calculation includes the period between 02.March.2000 and 31.May.2004 and is taken from the meteorological mast ( ) in Istanbul Technical University's campus area. The measurement data is taken from 2 m and 10 m heights with hourly means. The topography, roughness classes and shelter effects are defined in the models to make accurate extrapolation to the turbine sites. As an advantage, the region is nearly 3.5 km close to the Istanbul Bosphorous but as it can be seen from the Wasp and WindPro Model Results, the Bosphorous effect is interrupted by the new buildings and hight forestry. The shelter effect of these high buildings have a great influence on the wind flow and decrease the high wind energy potential which is produced by the Bosphorous effect. This study, which determines wind characteristics and expected annual production, is important for this Project Site and therefore gains importance before the construction of wind energy system. However, when the system is operating, developing the energy management skills, forecasting the wind speed and direction will become important. At this point, three statistical models which are Kalman Fitler, AR Model and Neural Networks models are used to determine the success of each method for correct
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-30
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning July 1, 2010, the interest rates for overpayments will be 3 percent for corporations and 4 percent for non- corporations, and the interest rate for underpayments will be 4 percent. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-13
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning January 1, 2011, the interest rates for overpayments will be 2 percent for corporations and 3 percent for non-corporations, and the interest rate for underpayments will be 3 percent. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-19
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning April 1, 2010, the interest rates for overpayments will be 3 percent for corporations and 4 percent for non-corporations, and the interest rate for underpayments will be 4 percent. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-27
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning October 1, 2010, the interest rates for overpayments will be 3 percent for corporations and 4 percent for non-corporations, and the interest rate for underpayments will be 4 percent. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-05
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning January 1, 2010, the interest rates for overpayments will be 3 percent for corporations and 4 percent for non-corporations, and the interest rate for underpayments will be 4 percent. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
NASA Astrophysics Data System (ADS)
Jones, David R.; Karl, David M.; Laws, Edward A.
1996-10-01
In field work conducted at 26°N, 155°W, in the North Pacific subtropical gyre, phytoplankton growth rates μp estimated from 14C labeling of chlorophyll a (chl a) averaged approximately one doubling per day in the euphotic zone (0-150 m). Microbial (microalgal plus heterotrophic bacterial) growth rates μm calculated from the incorporation of 3H-adenine into DNA were comparable to or exceeded phytoplankton growth rates at most depths in the euphotic zone. Photosynthetic rates averaged 727 mg C m -2 day -1 Phytoplankton carbon biomass, calculated from 14C labeling of chl a, averaged 7.2 mg m -3 in the euphotic zone. Vertical profiles of particulate DNA and ATP suggested that no more than 15% of particulate DNA was associated with actively growing cells. Heterotrophic bacterial carbon biomass was estimated from a two-year average at station ALOHA (22°45'N, 158°W) of flow cytometric counts of unpigmented, bacteria-size particles which bound DAPI on the assumption that 15% of the particles were actively growing cells and that heterotrophic bacterial cells contained 20 fg C cell -1 The heterotrophic bacterial carbon so calculated averaged 1.1 mg m -3 in the euphotic zone. Heterotrophic bacterial production was estimated to be 164 mg C m -2 day -1 or 23% of the calculated photosynthetic rate. Estimated heterotrophic bacterial growth rates averaged 0.97 day -1 in the euphotic zone and reached 4.7 day - at a depth of 20 m. Most heterotrophic bacterial production occurred in the upper 40 m of the euphotic zone, suggesting that direct excretion by phytoplankton, perhaps due to photorespiration or ultraviolet light effects, was a significant source of dissolved organic carbon for the bacteria.
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
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
r-PROCESS LANTHANIDE PRODUCTION AND HEATING RATES IN KILONOVAE
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.
r-process Lanthanide Production and Heating Rates in Kilonovae
NASA Astrophysics Data System (ADS)
Lippuner, Jonas; Roberts, Luke F.
2015-12-01
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 & 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 Ye, initial specific entropies s, and expansion timescales τ. We find that the ejecta is lanthanide-free for Ye ≳ 0.22-0.30, depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Ye 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 Ye, 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 Ye, s, and τ to estimate whether or not the ejecta is lanthanide-rich.
Zymomonas mobilis mutants with an increased rate of alcohol production
Osman, Y.A.; Ingram, L.O.
1987-07-01
Two new derivatives of Zymomonas mobilis CP4 were isolated from enrichment cultures after 18 months of serial transfer. These new strains were selected for the ability to grow and produce ethanol rapidly on transfer into fresh broth containing ethanol and allyl alcohol. Ethanol production by these strains was examined in batch fermentations under three sets of conditions. Both new derivatives were found to be superior to the parent strain CP4 with respect to the speed and completeness of glucose conversion to ethanol. The best of these, strain YO2, produced 9.5% ethanol (by weight; 11.9% by volume) after 17.4 h compared with 31.8 h for the parent strain CP4. The addition of 1 mM magnesium sulfate improved ethanol production in all three strains. Two factors contributed to the decrease in fermentation time required by the mutants: more rapid growth with minimal lag on subculturing and the retention of higher rates of ethanol production as fermentation proceeded. Alcohol dehydrogenase isozymes were altered in both new strains and no longer catalyzed the oxidation of allyl alcohol into the toxic product acrolein. This loss of allyl alcohol-oxidizing capacity is proposed as a primary factor contributing to increased allyl alcohol resistance, although it is likely that other mutations affecting glycolysis also contribute to the improvement in ethanol production.
Estimates of Biogenic Methane Production Rates in Deep Marine Sediments
NASA Astrophysics Data System (ADS)
Colwell, F. S.; Boyd, S.; Delwiche, M. E.; Reed, D. W.
2004-12-01
Much of the methane in natural gas hydrates in marine sediments is made by methanogens. Current models used to predict hydrate distribution and concentration in these sediments require estimates of microbial methane production rates. However, accurate estimates are difficult to achieve because of the bias introduced by sampling and because methanogen activities in these sediments are low and not easily detected. To derive useful methane production rates for marine sediments we have measured the methanogen biomass in samples taken from different depths in Hydrate Ridge (HR) sediments off the coast of Oregon and, separately, the minimal rates of activity for a methanogen in a laboratory reactor. For methanogen biomass, we used a polymerase chain reaction assay in real time to target the methanogen-specific mcr gene. Using this method we found that a majority of the samples collected from boreholes at HR show no evidence of methanogens (detection limit: less than 100 methanogens per g of sediment). Most of the samples with detectable numbers of methanogens were from shallow sediments (less than 10 meters below seafloor [mbsf]) although a few samples with apparently high numbers of methanogens (greater than 10,000 methanogens per g) were from as deep as 230 mbsf and were associated with notable geological features (e.g., the bottom-simulating reflector and an ash-bearing zone with high fluid movement). Laboratory studies with Methanoculleus submarinus (isolated from a hydrate zone at the Nankai Trough) maintained in a biomass recycle reactor showed that when this methanogen is merely surviving, as is likely the case in deep marine sediments, it produces approximately 0.06 fmol methane per cell per day. This is far lower than rates reported for methanogens in other environments. By combining this estimate of specific methanogenic rates and an extrapolation from the numbers of methanogens at selected depths in the sediment column at HR sites we have derived a maximum
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...
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 rate...
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....253 Special rates or rate ranges for leader, supervisory, and production facilitating positions. (a) When special rates or rate ranges are established for nonsupervisory positions, a lead agency...
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.
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.
30 CFR 250.1159 - May the Regional Supervisor limit my well or reservoir production rates?
Code of Federal Regulations, 2010 CFR
2010-07-01
... reservoir production rates? 250.1159 Section 250.1159 Mineral Resources MINERALS MANAGEMENT SERVICE... Gas Production Requirements Production Rates § 250.1159 May the Regional Supervisor limit my well or reservoir production rates? (a) The Regional Supervisor may set a Maximum Production Rate (MPR) for a...
Subterranean production of neutrons, 39Ar and 21Ne: Rates and uncertainties
NASA Astrophysics Data System (ADS)
Šrámek, Ondřej; Stevens, Lauren; McDonough, William F.; Mukhopadhyay, Sujoy; Peterson, R. J.
2017-01-01
Accurate understanding of the subsurface production rate of the radionuclide 39Ar is necessary for argon dating techniques and noble gas geochemistry of the shallow and the deep Earth, and is also of interest to the WIMP dark matter experimental particle physics community. Our new calculations of subsurface production of neutrons, 21Ne , and 39Ar take advantage of the state-of-the-art reliable tools of nuclear physics to obtain reaction cross sections and spectra (TALYS) and to evaluate neutron propagation in rock (MCNP6). We discuss our method and results in relation to previous studies and show the relative importance of various neutron, 21Ne , and 39Ar nucleogenic production channels. Uncertainty in nuclear reaction cross sections, which is the major contributor to overall calculation uncertainty, is estimated from variability in existing experimental and library data. Depending on selected rock composition, on the order of 107-1010 α particles are produced in one kilogram of rock per year (order of 1-103 kg-1 s-1); the number of produced neutrons is lower by ∼ 6 orders of magnitude, 21Ne production rate drops by an additional factor of 15-20, and another one order of magnitude or more is dropped in production of 39Ar. Our calculation yields a nucleogenic 21Ne /4He production ratio of (4.6 ± 0.6) ×10-8 in Continental Crust and (4.2 ± 0.5) ×10-8 in Oceanic Crust and Depleted Mantle. Calculated 39Ar production rates span a great range from 29 ± 9 atoms kg-rock-1 yr-1 in the K-Th-U-enriched Upper Continental Crust to (2.6 ± 0.8) × 10-4 atoms kg-rock-1 yr-1 in Depleted Upper Mantle. Nucleogenic 39Ar production exceeds the cosmogenic production below ∼700 m depth and thus, affects radiometric ages of groundwater. The 39Ar chronometer, which fills in a gap between 3H and 14C , is particularly important given the need to tap deep reservoirs of ancient drinking water.
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.
The production rate of cosmogenic deuterium at the Moon's surface
NASA Astrophysics Data System (ADS)
Füri, Evelyn; Deloule, Etienne; Trappitsch, Reto
2017-09-01
The hydrogen (D/H) isotope ratio is a key tracer for the source of planetary water. However, secondary processes such as solar wind implantation and cosmic ray induced spallation reactions have modified the primordial D/H signature of 'water' in all rocks and soils recovered on the Moon. Here, we re-evaluate the production rate of cosmogenic deuterium (D) at the Moon's surface through ion microprobe analyses of hydrogen isotopes in olivines from eight Apollo 12 and 15 mare basalts. These in situ measurements are complemented by CO2 laser extraction-static mass spectrometry analyses of cosmogenic noble gas nuclides (3He, 21Ne, 38Ar). Cosmic ray exposure (CRE) ages of the mare basalts, derived from their cosmogenic 21Ne content, range from 60 to 422 Ma. These CRE ages are 35% higher, on average, than the published values for the same samples. The amount of D detected in the olivines increases linearly with increasing CRE ages, consistent with a production rate of (2.17 ± 0.11) ×10-12 mol(g rock)-1 Ma-1. This value is more than twice as high as previous estimates for the production of D by galactic cosmic rays, indicating that for water-poor lunar samples, i.e., samples with water concentrations ≤50 ppm, corrected D/H ratios have been severely overestimated.
Voice recognition versus transcriptionist: error rates and productivity in MRI reporting.
Strahan, Rodney H; Schneider-Kolsky, Michal E
2010-10-01
Despite the frequent introduction of voice recognition (VR) into radiology departments, little evidence still exists about its impact on workflow, error rates and costs. We designed a study to compare typographical errors, turnaround times (TAT) from reported to verified and productivity for VR-generated reports versus transcriptionist-generated reports in MRI. Fifty MRI reports generated by VR and 50 finalized MRI reports generated by the transcriptionist, of two radiologists, were sampled retrospectively. Two hundred reports were scrutinised for typographical errors and the average TAT from dictated to final approval. To assess productivity, the average MRI reports per hour for one of the radiologists was calculated using data from extra weekend reporting sessions. Forty-two % and 30% of the finalized VR reports for each of the radiologists investigated contained errors. Only 6% and 8% of the transcriptionist-generated reports contained errors. The average TAT for VR was 0 h, and for the transcriptionist reports TAT was 89 and 38.9 h. Productivity was calculated at 8.6 MRI reports per hour using VR and 13.3 MRI reports using the transcriptionist, representing a 55% increase in productivity. Our results demonstrate that VR is not an effective method of generating reports for MRI. Ideally, we would have the report error rate and productivity of a transcriptionist and the TAT of VR. © 2010 The Authors. Journal of Medical Imaging and Radiation Oncology © 2010 The Royal Australian and New Zealand College of Radiologists.
The cancer Warburg effect may be a testable example of the minimum entropy production rate principle
NASA Astrophysics Data System (ADS)
Marín, Dolores; Sabater, Bartolomé
2017-04-01
Cancer cells consume more glucose by glycolytic fermentation to lactate than by respiration, a characteristic known as the Warburg effect. In contrast with the 36 moles of ATP produced by respiration, fermentation produces two moles of ATP per mole of glucose consumed, which poses a puzzle with regard to the function of the Warburg effect. The production of free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) per mole linearly varies with the fraction (x) of glucose consumed by fermentation that is frequently estimated around 0.9. Hence, calculation shows that, in respect to pure respiration, the predominant fermentative metabolism decreases around 10% the production of entropy per mole of glucose consumed in cancer cells. We hypothesize that increased fermentation could allow cancer cells to accomplish the Prigogine theorem of the trend to minimize the rate of production of entropy. According to the theorem, open cellular systems near the steady state could evolve to minimize the rates of entropy production that may be reached by modified replicating cells producing entropy at a low rate. Remarkably, at CO2 concentrations above 930 ppm, glucose respiration produces less entropy than fermentation, which suggests experimental tests to validate the hypothesis of minimization of the rate of entropy production through the Warburg effect.
Cageao, R P; Ha, Y L; Jiang, Y; Morgan, M F; Yung, Y L; Sander, S P
1997-05-01
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.
Odland, D; Davis, C
1982-08-01
Plain muffins, yellow cake, baked custard, apple pie, tuna casserole, frozen tuna casserole, cheese soufflé, and meat loaf were baked in preheated and non-preheated standard gas, continuous-clean gas, standard electric, and self-cleaning electric ovens. Products generally required 5 min. or less extra baking time when cooked in non-preheated rather than in preheated ovens. The variability in baking times often was less between preheated and non-preheated ovens than among oven types. Calculated energy consumption values showed that usually less energy was required to bake products in non-preheated than in preheated ovens; savings averaged about 10 percent. Few significant differences were found in physical measurements or eating quality either between preheated and non-preheated ovens or among oven types. Overall, for the products tested, findings confirmed that preheating the oven is not essential for good product quality and, therefore, is an unnecessary use of energy.
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).
Mcnp-Based Methodology to Calculate Helium Production in Bwr Shrouds
NASA Astrophysics Data System (ADS)
Sitaraman, S.; Chiang, R.-T.; Oliver, B. M.
2003-06-01
A three-dimensional computational method based on Monte Carlo radiation transport techniques was developed to calculate thermal and fast neutron fields in the downcomer region of a Boiling Water Reactor (BWR). This methodology was validated using measured data obtained from an operating BWR. The helium production was measured in stainless steel at locations near the shroud and compared with values from the Monte Carlo calculations. The methodology produced results that were in agreement with measurements, thereby providing a useful tool for the determination of helium levels in shroud components.
Rabahi, Tahar; Fargier, Patrick; Rifai-Sarraj, Ahmad; Clouzeau, Cyril; Massarelli, Raphael
2012-01-25
Several results in the literature show that motor imagery, language production, mental calculation, and motor execution share the same or closely related brain motor cortical areas. The present study aimed at investigating the possible influence of specific action verb (AV) pronunciation and mental calculus upon motor performance compared with kinesthetic imagery (KI). Participants, novice in mental imagery, performed a vertical jump after a cognitive task (AV, silent AV, mental subtraction, meaningless verb, and KI). The results show that specific lower limbs AV, mental calculation, and KI improved the vertical jump in male, but not in female participants. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.
Associated Higgs-W-boson production at hadron colliders: a fully exclusive QCD calculation at NNLO.
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.
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
Universal scaling of production rates across mammalian lineages
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
Production of carboxylates from high rate activated sludge through fermentation.
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.
Universal scaling of production rates across mammalian lineages.
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.
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.
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.
NASA Astrophysics Data System (ADS)
Jaboulay, Jean-Charles; Brun, Emeric; Hugot, François-Xavier; Huynh, Tan-Dat; Malouch, Fadhel; Mancusi, Davide; Tsilanizara, Aime
2017-09-01
After fission or fusion reactor shutdown the activated structure emits decay photons. For maintenance operations the radiation dose map must be established in the reactor building. Several calculation schemes have been developed to calculate the shutdown dose rate. These schemes are widely developed in fusion application and more precisely for the ITER tokamak. This paper presents the rigorous-two-steps scheme implemented at CEA. It is based on the TRIPOLI-4® Monte Carlo code and the inventory code MENDEL. The ITER shutdown dose rate benchmark has been carried out, results are in a good agreement with the other participant.
Forest turnover rates follow global and regional patterns of productivity
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.
Investigating nutrient profiling and Health Star Ratings on core dairy products in Australia.
Wellard, Lyndal; Hughes, Clare; Watson, Wendy L
2016-10-01
To determine whether the ratings from the Australian front-of-pack labelling scheme, Health Star Rating (HSR), and the ability to carry health claims using the Nutrient Profiling Scoring Criterion (NPSC) for core dairy products promote foods consistent with the Australian Dietary Guidelines. The Australian nutrient profiling model used for assessing eligibility for health claims was compared with the nutrient profiling model underpinning the HSR system to determine their agreement when assessing dairy products. Agreement between the extent to which products met nutrient profiling criteria and scored three stars or over using the HSR calculator was determined using Cohen's kappa tests. The four largest supermarket chains in Sydney, Australia. All available products in the milk, hard cheese, soft cheese and yoghurt categories (n 1363) were surveyed in March-May 2014. Nutrition composition and ingredients lists were recorded for each product. There was 'good' agreement between NPSC and HSR overall (κ=0·78; 95 % CI 0·75, 0·81; P<0·001), for hard cheeses (κ=0·72; 95 % CI 0·65, 0·79; P<0·001) and yoghurt (κ=0·79; 95 % CI 0·73, 0·86; P<0·001). There was 'fair' agreement for milk (κ=0·33; 95 % CI 0·20, 0·45; P<0·001) and 'very good' agreement for soft cheese (κ=0·84; 95 % CI 0·75, 0·92; P<0·001). Generally, products tended to have HSR consistent with other products of a similar type within their categories. For dairy products, the HSR scheme largely aligned with the NPSC used for determining eligibility for health claims. Both systems appeared be consistent with the Australian Dietary Guidelines for dairy products, with lower-fat products rating higher.
NASA Astrophysics Data System (ADS)
Kürten, Andreas; Bianchi, Federico; Almeida, Joao; Kupiainen-Määttä, Oona; Dunne, Eimear M.; Duplissy, Jonathan; Williamson, Christina; Barmet, Peter; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M.; Flagan, Richard C.; Franchin, Alessandro; Gordon, Hamish; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Ickes, Luisa; Jokinen, Tuija; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Onnela, Antti; Ortega, Ismael K.; Petäjä, Tuukka; Praplan, Arnaud P.; Riccobono, Francesco; Rissanen, Matti P.; Rondo, Linda; Schnitzhofer, Ralf; Schobesberger, Siegfried; Smith, James N.; Steiner, Gerhard; Stozhkov, Yuri; Tomé, António; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Wagner, Paul E.; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Ken; Kulmala, Markku; Curtius, Joachim
2016-10-01
Binary nucleation of sulfuric acid and water as well as ternary nucleation involving ammonia are thought to be the dominant processes responsible for new particle formation (NPF) in the cold temperatures of the middle and upper troposphere. Ions are also thought to be important for particle nucleation in these regions. However, global models presently lack experimentally measured NPF rates under controlled laboratory conditions and so at present must rely on theoretical or empirical parameterizations. Here with data obtained in the European Organization for Nuclear Research CLOUD (Cosmics Leaving OUtdoor Droplets) chamber, we present the first experimental survey of NPF rates spanning free tropospheric conditions. The conditions during nucleation cover a temperature range from 208 to 298 K, sulfuric acid concentrations between 5 × 105 and 1 × 109 cm-3, and ammonia mixing ratios from zero added ammonia, i.e., nominally pure binary, to a maximum of 1400 parts per trillion by volume (pptv). We performed nucleation studies under pure neutral conditions with zero ions being present in the chamber and at ionization rates of up to 75 ion pairs cm-3 s-1 to study neutral and ion-induced nucleation. We found that the contribution from ion-induced nucleation is small at temperatures between 208 and 248 K when ammonia is present at several pptv or higher. However, the presence of charges significantly enhances the nucleation rates, especially at 248 K with zero added ammonia, and for higher temperatures independent of NH3 levels. We compare these experimental data with calculated cluster formation rates from the Atmospheric Cluster Dynamics Code with cluster evaporation rates obtained from quantum chemistry.
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.
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.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-28
..., Regulations and Methodology for Calculating Dumping Margins (``Zeroing'') (``US-Zeroing (EC)''), WT/ DS294/R... (``US-Continued Zeroing (EC)''), WT/DS350/R, WR/DS350/ AB/R, adopted Feb. 19, 2009. Proposal for... settlement findings. The WTO Appellate Body in US-Zeroing (EC), US-Zeroing (Japan), US-Stainless...
42 CFR 412.523 - Methodology for calculating the Federal prospective payment rates.
Code of Federal Regulations, 2010 CFR
2010-10-01
... beginning on or after October 1, 2002 through June 30, 2003. (ii) For long-term care hospital prospective... SERVICES Prospective Payment System for Long-Term Care Hospitals § 412.523 Methodology for calculating the... inpatient hospital services furnished by long-term care hospitals, CMS uses— (1) The best Medicare data...
45 CFR 286.85 - How will we calculate the work participation rates?
Code of Federal Regulations, 2011 CFR
2011-10-01
... SERVICES TRIBAL TANF PROVISIONS Tribal TANF Plan Content and Processing § 286.85 How will we calculate the... work activity approved in the TFAP for at least the minimum number of hours approved in the TFAP. (b... ratio: (1) The number of families receiving TANF assistance that include an adult or a minor head-of...
NASA Technical Reports Server (NTRS)
Wilson, S. W.
1978-01-01
Equations and coefficients for calculating the flux of solid particles in the exhaust plumes of the interim upper stage and SSUS solid rocket motors (SRM) are considered. Modifications required to account for the independent motions of the orbiter and the SRM, such as will result during an on-orbit SRM firing are described.
NASA Astrophysics Data System (ADS)
Hu, Wei-Ping; Lynch, Gillian C.; Liu, Yi-Ping; Rossi, Ivan; Stewart, James J. P.; Steckler, Rozeanne; Garrett, Bruce C.; Isaacson, Alan D.; Lu, Da-hong; Melissas, Vasilios S.; Truhlar, Donald G.
1995-08-01
MORATE (Molecular Orbital RATE calculations) is a computer program for direct dynamics calculations of unimolecular and bimolecular rate constants of gas-phase chemical reactions involving atoms, diatoms, or polyatomic species. The dynamical methods used are conventional or variational transition state theory and multidimensional semiclassical approximations for tunneling and nonclassical reflection. Variational transition states are found by a one-dimensional search of generalized-transition-state dividing surfaces perpendicular to the minimum-energy path, and tunneling probabilities are evaluated by multidimensional semiclassical algorithms, including the small-curvature and large-curvature tunneling approximations and the microcanonical optimized multidimensional tunneling approximation. The computer program is a conventiently interfaced package consisting of the POLYRATE program, version 6.5, for dynamical rate constant calculations, and the MOPAC program, version 5.05mn, for semiempirical electronic structure computations. In single-level mode, the potential energies, gradients, and higher derivatives of the potential are computed whenever needed by electronic structure calculations employing semiempirical molecular orbital theory without the intermediary of a global or semiglobal fit. All semiempirical methods available in MOPAC, in particular MINDO/3, MNDO, AM1, and PM3, can be called on to calculate the potential, gradient, or Hessian, as required at various steps of the dynamics calculations, and, in addition, the code has flexible options for electronic structure calculations with neglect of diatomic differential overlap and specific reaction parameters (NDDO-SRP). In dual-level mode, MINDO/3, MNDO, AM1, PM3, or NDDO-SRP is used as a lower level to calculate the reaction path, and interpolated corrections to energies and frequencies are added; these corrections are based on higher-level data read from an external file.
2014 Guide to Calculating School Improvement Ratings for Alternative Schools and ESE Centers
ERIC Educational Resources Information Center
Florida Department of Education, 2014
2014-01-01
The purpose of this technical assistance paper is to provide a description of the procedures used to determine school improvement ratings for alternative schools and ESE centers for the most recently completed school year. School improvement ratings are part of Florida's school accountability system, which originated with the Florida Legislature's…
NASA Astrophysics Data System (ADS)
Vázquez, Héctor; Troisi, Alessandro
2013-11-01
We investigate the process of exciton dissociation in ordered and disordered model donor/acceptor systems and describe a method to calculate exciton dissociation rates. We consider a one-dimensional system with Frenkel states in the donor material and states where charge transfer has taken place between donor and acceptor. We introduce a Green's function approach to calculate the generation rates of charge-transfer states. For disorder in the Frenkel states we find a clear exponential dependence of charge dissociation rates with exciton-interface distance, with a distance decay constant β that increases linearly with the amount of disorder. Disorder in the parameters that describe (final) charge-transfer states has little effect on the rates. Exciton dissociation invariably leads to partially separated charges. In all cases final states are “hot” charge-transfer states, with electron and hole located far from the interface.
Application of Origen2.1 in the decay photon spectrum calculation of spallation products
NASA Astrophysics Data System (ADS)
Hong, Shuang; Yang, Yong-Wei; Xu, Hu-Shan; Meng, Hai-Yan; Zhang, Lu; Liu, Zhao-Qing; Gao, Yu-Cui; Chen, Kang
2016-11-01
Origen2.1 is a widely used computer code for calculating the burnup, decay, and processing of radioactive materials. However, the nuclide library of Origen2.1 is used for existing reactors like pressurized water reactors. To calculate the photon spectrum released by the decay of spallation products, we have made specific libraries for the ADS tungsten spallation target, based on the results given by the FLUKA Monte Carlo code. All the data used to make the Origen2.1 libraries are obtained from Nuclear structure & decay Data (NuDat2.6). The accumulated activity of spallation products and the contribution of nuclides to photon emission are given in this paper. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03030102)
Mowlavi, Ali Asghar; Fornasie, Maria Rosa; de Denaro, Mario
2011-01-01
In this study, the MCNPX code has been used to simulate a proton therapy in thyroid gland, in order to calculate the proton energy deposition in the target region. As well as, we have calculated the photon and neutron production spectra due to proton interactions with the tissue. We have considered all the layers of tissue, from the skin to the thyroid gland, and an incident high energy pencil proton beam. The results of the simulation show that the best proton energy interval, to cover completely the thyroid tissue, is from 42 to 54 MeV, assuming that the thyroid gland has a 14 mm thickness and is located 11.2mm under the skin surface. The most percentage of deposited energy (78%) is related to the 54 MeV proton energy beam. Total photon and neutron production are linear and polynomial second order functions of the proton energy, respectively.
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.
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
Estimating long-term exposure levels in process-type industries using production rates.
Kalliokoski, P
1990-06-01
Exposure to toluene in two publication rotogravure plants was investigated to examine how accurately long-term exposure can be estimated on the basis of production rate. Toluene consumption was used as the measure of production rate. Continuous area monitoring was used to find a correlation between production rate and airborne level of toluene. Workers' exposure levels were first estimated by combining data on toluene concentrations in various monitoring sites with data supplied by the workers on the time spent in these areas. These calculated exposure levels were found to correlate well with the actual exposure levels obtained by breathing zone sampling. There was also a fairly high correlation between the concentration of toluene in front of the press and the consumption of toluene if the process conditions remained stable. It was, however, necessary to investigate this association separately for the situations where the degree of enclosure of the press or number of emission sources were unusual or when the workers stayed in the control rooms, which were separated from the other pressroom areas. A reasonably high correlation between the variables of the main interest, that is, the calculated toluene exposures and the consumption of toluene, was found in one of the plants investigated, whereas this correlation was low in the other plant. Even though this kind of estimation procedure does not always lead to accurate exposure levels, it helps in understanding how those are affected by the process parameters.
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.
NASA Astrophysics Data System (ADS)
Nabi, Jameel-Un
2008-09-01
A few white dwarfs, located in binary systems, may acquire sufficiently high mass-accretion rates resulting in the burning of carbon and oxygen under nondegenerate conditions forming an O+Ne+Mg core. These O+Ne+Mg cores are gravitationally less bound than more massive progenitor stars and can release more energy due to the nuclear burning. They are also amongst the probable candidates for low entropy r-process sites. Recent observations of subluminous Type II-P supernovae (e.g. 2005cs, 2003gd, 1999br and 1997D) were able to rekindle the interest in 8-10 Modot which develop O+Ne+Mg cores. Microscopic calculations of capture rates on 24Mg, which may contribute significantly to the collapse of O+Ne+Mg cores, using the shell model and the proton-neutron quasiparticle random-phase approximation (pn-QRPA) theory, were performed earlier and comparisons made. Simulators, however, may require these capture rates on a fine scale. For the first time, a detailed microscopic calculation of the electron and positron capture rates on 24Mg on an extensive temperature-density scale is presented here. This type of scale is more appropriate for interpolation purposes and of greater utility for simulation codes. The calculations are done using the pn-QRPA theory using a separable interaction. The deformation parameter, believed to be a key parameter in QRPA calculations, is adopted from experimental data to increase the reliability of the QRPA results further. The resulting calculated rates are up to a factor of 14 or more enhanced as compared to shell model rates and may lead to some interesting scenarios for core collapse simulators.
Estrogen elevates the peak overnight production rate of acylated ghrelin.
Paulo, Remberto C; Brundage, Richard; Cosma, Mihaela; Mielke, Kristi L; Bowers, Cyril Y; Veldhuis, Johannes D
2008-11-01
Acylated ghrelin is the putatively bioactive GH secretagogue. Estradiol (E2) stimulates the synthesis rather than inhibits the metabolic clearance of acylated ghrelin. The study took place at an academic medical center. Healthy postmenopausal women participated. Interventions included prospectively randomized, double-blind separate-day iv infusions of saline or five graded doses of ghrelin in estrogen-deficient (n=12) and E2-supplemented (n=8) women. Metabolic clearance rate (MCR), volume of distribution, half-life, and secretion rate of acylated ghrelin were assessed. In pilot iv bolus ghrelin infusions, the median half-lives of acylated and total ghrelin were 21 and 36 min (P<0.01), MCRs 58 and 8.1 liters/kg.d (P<0.01), and volumes of distribution of 1.0 and 0.32 liters/kg (P<0.01), respectively. Transdermal E2 supplementation for 3 wk increased peak nighttime acylated ghrelin concentrations from 99+/-12 to 141+/-34 pg/ml (P=0.039). Exposure to E2 did not alter the linear relationships between 1) plasma acylated ghrelin concentration and ghrelin infusion rate (638+/-12 slope units), 2) MCR of acylated ghrelin and ghrelin infusion rate (10+/-2.5 slope units), and 3) MCR and plasma concentration of acylated ghrelin (0.017+/-0.004 slope units). These data predict peak nighttime production rates of acylated ghrelin of 3.8+/-0.9 (E2) and 1.9+/-0.2 (no E2) ng/kg.min (P=0.039). Acylated ghrelin has a multifold larger distribution volume and MCR than total ghrelin. An estrogenic milieu augments synthesis and/or acylation of ghrelin peptide without altering its MCR.
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
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.
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.
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.
The production rate of cosmogenic 10Be at the Koefels rockslide site, Austria
NASA Astrophysics Data System (ADS)
Ivy-Ochs, Susan; Kerschner, Hanns; Kober, Florian; Salcher, Bernhard; Christl, Marcus; Schluechter, Christian
2017-04-01
The Koefels rockslide, with a volume of 2-3 km3, involved sliding of predominantly orthogneiss (granitic and augen gneiss) from the Schartle ridge on the west side of Ötztal eastward into the mouth of Horlachtal. The dating of compressed wood fragments found in a tunnel built for a later abandoned waterworks project in the 1960s indicated an early Holocene age. In the 1990s we initiated a study to use the Koefels rockslide as a calibration site for cosmogenic 10Be and 26Al production rates. As the Koefels production rates were markedly higher than those from other sites, the Koefels site was not included in the final CRONUS-Earth calibration data set (Borchers et al. 2016). We discuss a re-assessment of the geomorphological interpretation of the 27 boulder and bedrock 10Be exposure dates, nine of which were previously published. In light of recent dating of further buried wood pieces to 9527-9498 yr ago (Nicolussi et al. 2015), we present the 10Be production rate calculated based on the Koefels data. Borchers B. et al. 2016. Geological calibration of spallation production rates in the CRONUS-Earth project. Quaternary Geochronology 31: 188-198. Nicolussi K. et al. 2015. Precise radiocarbon dating of the giant Köfels landslide (Eastern Alps, Austria). Geomorphology 243: 87-91.
Substrate inhibition and control for high rate biogas production
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.
Dose Rate Calculations from Radioactive Vascular Stents: DPK Versus Exact MC Approach
NASA Astrophysics Data System (ADS)
Gorodkov, S.; Möslang, A.; Vladimirov, P.
Vascular stents activated with radioactive isotopes are planned to be used in clinical practice to prevent restenosis in human coronary arteries after balloon angioplasty. Medical stents are cylindrical meshes and their complex geometry is usually treated for energy dose calculation with approximate dose point kernel (DPK) approach. The important point missed in the DPK approach is the absence of the stent material and, hence, the absence of energy absorption inside the stent. We have performed a comparison between DPK and exact Monte Carlo calculations for some simplified stent models. It appears that DPK approximation significantly overestimates pike dose values especially for the case of γ-emitting sources. We suggest DPK kernel normalization, which minimizes the difference at relatively far distances, while significant discrepancies near the stent surface still remain.
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.
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.
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.
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.
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
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NEW CALCULATION OF ANTIPROTON PRODUCTION BY COSMIC RAY PROTONS AND NUCLEI
Kachelriess, Michael; Moskalenko, Igor V.; Ostapchenko, Sergey S.
2015-04-20
A dramatic increase in the accuracy and statistics of space-borne cosmic ray (CR) measurements has yielded several breakthroughs over the last several years. The most puzzling is the rise in the positron fraction above ∼10 GeV over the predictions of the propagation models assuming pure secondary production. The accuracy of the antiproton production cross section is critical for astrophysical applications and searches for new physics since antiprotons in CRs seem to hold the keys to many puzzles including the origin of those excess positrons. However, model calculations of antiproton production in CR interactions with interstellar gas are often employing parameterizations that are out of date or are using outdated physical concepts. This may lead to an incorrect interpretation of antiproton data which could have broad consequences for other areas of astrophysics. In this work, we calculate antiproton production in pp-, pA-, and AA-interactions using EPOS-LHC and QGSJET-II-04, two of the most advanced Monte Carlo (MC) generators tuned to numerous accelerator data including those from the Large Hadron Collider (LHC). We show that the antiproton yields obtained with these MC generators differ by up to an order of magnitude from yields of parameterizations commonly used in astrophysics.
New Calculation of Antiproton Production by Cosmic Ray Protons and Nuclei
NASA Astrophysics Data System (ADS)
Kachelriess, Michael; Moskalenko, Igor V.; Ostapchenko, Sergey S.
2015-04-01
A dramatic increase in the accuracy and statistics of space-borne cosmic ray (CR) measurements has yielded several breakthroughs over the last several years. The most puzzling is the rise in the positron fraction above ∼10 GeV over the predictions of the propagation models assuming pure secondary production. The accuracy of the antiproton production cross section is critical for astrophysical applications and searches for new physics since antiprotons in CRs seem to hold the keys to many puzzles including the origin of those excess positrons. However, model calculations of antiproton production in CR interactions with interstellar gas are often employing parameterizations that are out of date or are using outdated physical concepts. This may lead to an incorrect interpretation of antiproton data which could have broad consequences for other areas of astrophysics. In this work, we calculate antiproton production in pp-, pA-, and AA-interactions using EPOS-LHC and QGSJET-II-04, two of the most advanced Monte Carlo (MC) generators tuned to numerous accelerator data including those from the Large Hadron Collider (LHC). We show that the antiproton yields obtained with these MC generators differ by up to an order of magnitude from yields of parameterizations commonly used in astrophysics.
NASA Astrophysics Data System (ADS)
Jiang, Y.; Shan, X.; Song, X.
2016-12-01
How to estimate strain rate field of active faults is a key question in geophysics science. With the rapid development of geodetic techniques, GPS and InSAR are powerful techniques to monitor crustal deformation, and provide essential dataset for strain rate calculation. However, there are multiple methods of calculating strain rate field, and some of them may lead to entirely different results even with common data. Two experiments are conducted in this study, and all of them are based on simulated data. The aim of the first experiment is to compare three methods of calculating strain rate, I: triangular mesh method, II: neighboring point method in Cartesian coordinate system, whose weight is a function of distance, III: our method-applying method II in spherical coordinate system. The theoretical GPS velocity field and strain rate field are designed with resolution of 0.01, and close to an active fault. Observation velocity field is processed sparsely to 0.1 from theoretical velocity field. Three methods are used to compute strain rate field based on observation velocity field, and the results indicate that (1) result of method I is not smooth due to the mesh network, and several areas with high strain rate are unexpected; (2) results of method II and III are smooth, and their spatial patterns fit the theoretical strain rate field; (3) RMS magnitude related to coordinate system is same as magnitude of theoretical strain rate field. In real case, observation error is inevitable in GPS data, so random error is added in the second experiment. Based on method III, we calculate strain rate field from GPS data with observation error. The result shows that observation error causes a gross distortion. Then we add InSAR with random error to GPS data, and the result shows that based on the combination of GPS and InSAR, RMS magnitude of velocity field and strain rate field is much smaller than that based on GPS only. This experiment suggests that combining GPS and In
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-24
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning July 1, 2013, the interest rates for overpayments will be 2 percent for corporations and 3 percent for non- corporations, and the interest rate for underpayments will be 3 percent for both corporations and non-corporations. This notice is published for the convenience of the importing public and U.S. Customs and Border Protection personnel.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-19
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning October 1, 2011, the interest rates for overpayments will be 2 percent for corporations and 3 percent for non-corporations, and the interest rate for underpayments will be 3 percent for both corporations and non-corporations. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
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2012-03-27
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Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-13
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning July 1, 2011, the interest rates for overpayments will be 3 percent for corporations and 4 percent for non- corporations, and the interest rate for underpayments will be 4 percent for both corporations and non-corporations. This notice is published for the convenience of the importing public and Customs and Border Protection personnel.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-04
...This notice advises the public of the quarterly Internal Revenue Service interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. For the calendar quarter beginning April 1, 2013, the interest rates for overpayments will be 2 percent for corporations and 3 percent for non-corporations, and the interest rate for underpayments will be 3 percent for both corporations and non-corporations. This notice is published for the convenience of the importing public and U.S. Customs and Border Protection personnel.
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.
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.
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.
Tantillo, Dean J
2013-08-01
This Highlight describes applications of quantum chemical calculations to problems in natural products chemistry, including the elucidation of natural product structures (distinguishing between constitutional isomers, distinguishing between diastereomers, and assigning absolute configuration) and determination of reasonable mechanisms for their formation.
Calculation on cosmic-ray muon exposure rate in non-walled concrete buildings.
Fujitaka, K; Abe, S
1984-06-01
Computer simulations on the exposure indoors from cosmic ray muons were practiced in the framework of non-scattering and non-cascade assumptions. The model buildings were two-dimensional, rectangular, and were made of a normal concrete. A stratified structure was assumed in each building, where no mezzanine was considered. Walls were not taken into account yet. The distributions of the exposure rates in 26-story buildings were illustrated in contour maps for various sets of parameters. All of them gave basically archlike patterns. Analyses of the results showed that the exposure rate is affected most largely by the floor board thickness. The ceiling height would be an insignificant factor for short buildings. The min/max ratio of the muon exposure rate in a moderate size building was estimated to be more than 0.7.
Shell-model calculations of beta-decay rates for s- and r-process nucleosyntheses
NASA Astrophysics Data System (ADS)
Takahashi, K.; Mathews, G. J.; Bloom, S. D.
1985-10-01
Examples of large-basis shell-model calculations of Gamow-Teller (BETA)-decay properties of specific interest in the astrophysical s- and r- processes are presented. Numerical results are given for: (1) the GT-matrix elements for the excited state decays of the unstable s-process nucleus Tc-99; and (2) the GT-strength function for the neutron-rich nucleus Cd-130, which lies on the r-process path. The results are discussed in conjunction with the astrophysics problems.
A real-time path rating calculation tool powered by HPC
2016-06-09
If transmission path ratings are determined in real time and optimized control methods can be implemented, congestion problems can be more effectively managed using the existing transmission assets, reducing congestion costs, avoiding capital expenditures for new physical assets, increasing revenues from the existing system, and maintaining reliability. In just one illustrative case, a BPA study has shown that a 1000-MW rating increase for a transmission path generates $15M in annual revenue, even if only 25% of the increased margin can be tapped for just 25% of the year.
A novel path sampling method for the calculation of rate constants
NASA Astrophysics Data System (ADS)
van Erp, Titus S.; Moroni, Daniele; Bolhuis, Peter G.
2003-05-01
We derive a novel efficient scheme to measure the rate constant of transitions between stable states separated by high free energy barriers in a complex environment within the framework of transition path sampling. The method is based on directly and simultaneously measuring the fluxes through many phase space interfaces and increases the efficiency with at least a factor of 2 with respect to existing transition path sampling rate constant algorithms. The new algorithm is illustrated on the isomerization of a diatomic molecule immersed in a simple fluid.
NASA Astrophysics Data System (ADS)
Cocco, M.; Hainzl, S.; Catalli, F.; Enescu, B.; Lombardi, A. M.; Woessner, J.
2010-05-01
We use the Dieterich (1994) physics-based approach to simulate the spatiotemporal evolution of seismicity caused by stress changes applied to an infinite population of nucleating patches modeled through a rate- and state-dependent friction law. According to this model, seismicity rate changes depend on the amplitude of stress perturbation, the physical constitutive properties of faults (represented by the parameter Aσ), the stressing rate, and the background seismicity rate of the study area. In order to apply this model in a predictive manner, we need to understand the impact of physical model parameters and the correlations between them. First, we discuss different definitions of the reference seismicity rate and show their impact on the computed rate of earthquake production for the 1992 Landers earthquake sequence as a case study. Furthermore, we demonstrate that all model parameters are strongly correlated for physical and statistical reasons. We discuss this correlation, emphasizing that the estimations of the background seismicity rate, stressing rate, and Aσ are strongly correlated to reproduce the observed aftershock productivity. Our analytically derived relation demonstrates the impact of these model parameters on the Omori-like aftershock decay: the c value and the productivity of the Omori law, implying a p value smaller than or equal to 1. Finally, we discuss an optimal strategy to constrain model parameters for near-real-time forecasts.
Comparison of GiBUU calculations with MiniBooNE pion production data
Lalakulich, O.; Mosel, U.
2015-05-15
Background: Neutrino-induced pion production can give important informationon the axial coupling to nucleon resonances. Furthermore, pion production represents a major background to quasielastic-like events. one pion production data from the MiniBooNE in charged current neutrino scattering in mineral oil appeared higher than expected within conventional theoretical approaches. Purpose: We aim to investigate which model parameters affect the calculated cross section and how they do this. Method: The Giessen Boltzmann–Uehling–Uhlenbeck (GiBUU) model is used for an investigation of neutrino-nucleus reactions. Results: Presented are integrated and differential cross sections for 1π{sup +} and 1π{sup 0} production before and after final state interactions in comparison with the MiniBooNE data. Conclusions: For the MiniBooNE flux all processes (QE, 1π-background, Δ, higher resonance production, DIS) contribute to the observed final state with one pion of a given charge. The uncertainty in elementary pion production cross sections leads to a corresponding uncertainty in the nuclear cross sections. Final state interactions change the shape of the muon-related observables only slightly, but they significantly change the shape of pion distributions.
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.
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.
Production rates of terrestrial in-situ-produced cosmogenic nuclides
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.
Changes in atmospheric composition inferred from ionospheric production rates
NASA Technical Reports Server (NTRS)
Titheridge, J. E.
1974-01-01
Changes in the total electron content of the ionosphere near sunrise are used to determine the integrated production rate in the ionosphere (Q) from 1965 to 1971 at latitudes of 34S, 20N, and 34N. The observed regular semiannual variation in Q through a range of 1:3:1 is interpreted as an increase in the ratio O/N2 (relative densities) near the equinoxes. It follows that there is a worldwide semiannual variation in atmospheric composition, with the above ratio maximum just after the equinoxes. There is a large seasonal variation in the Northern hemisphere with a maximum in mid-summer. This effect is absent in the Southern hemisphere. At all times except solar maximum in the Northern hemisphere there is a global asymmetry. The ratio O/N2 is about three times as large in the Northern hemisphere. The overall mechanism appears to be N2 absorption.
NASA Astrophysics Data System (ADS)
Mella, Massimo
2006-03-01
Monte Carlo (MC) simulations can be used to compute microcanonical statistical rates of gas phase dissociation reactions. Unfortunately, the MC approach may suffer from a slow convergence and large statistical errors for energies just above the dissociation threshold. In this work, umbrella sampling is proposed as a device to reduce the statistical error of MC rate constants. The method is tested by computing the classical dissociation rate for the reaction [H5O2+]*→H2O+H3O+ over the range of internal energy 38
42 CFR 419.32 - Calculation of prospective payment rates for hospital outpatient services.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 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 Hospital...
Should thermostatted ring polymer molecular dynamics be used to calculate thermal reaction rates?
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.
Klein, Fred W.; Wright, Tom; Nakata, Jennifer
2006-01-01
We examined dozens of aftershock sequences in Hawaii in terms of Gutenberg-Richter and modified Omori law parameters. We studied p, the rate of aftershock decay; Ap, the aftershock productivity, defined as the observed divided by the expected number of aftershocks; and c, the time delay when aftershock rates begin to fall. We found that for earthquakes shallower than 20 km, p values >1.2 are near active magma centers. We associate this high decay rate with higher temperatures and faster stress relaxation near magma reservoirs. Deep earthquakes near Kilauea's inferred magma transport path show a range of p values, suggesting the absence of a large, deep magma reservoir. Aftershock productivity is >4.0 for flank earthquakes known to be triggered by intrusions but is normal (0.25 to 4.0) for isolated main shocks. We infer that continuing, post-main shock stress from the intrusion adds to the main shock's stress step and causes higher Ap. High Ap in other zones suggests less obvious intrusions and pulsing magma pressure near Kilauea's feeding conduit. We calculate stress rates and stress rate changes from pre-main shock and aftershock rates. Stress rate increased after many intrusions but decreased after large M7–8 earthquakes. Stress rates are highest in the seismically active volcano flanks and lowest in areas far from volcanic centers. We found sequences triggered by intrusions tend to have high Ap, high (>0.10 day) c values, a stress rate increase, and sometimes a peak in aftershock rate hours after the main shock. We interpret these values as indicating continuing intrusive stress after the main shock.
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.
Bi, Ran; Liu, Peng
2016-03-31
RNA-Sequencing (RNA-seq) experiments have been popularly applied to transcriptome studies in recent years. Such experiments are still relatively costly. As a result, RNA-seq experiments often employ a small number of replicates. Power analysis and sample size calculation are challenging in the context of differential expression analysis with RNA-seq data. One challenge is that there are no closed-form formulae to calculate power for the popularly applied tests for differential expression analysis. In addition, false discovery rate (FDR), instead of family-wise type I error rate, is controlled for the multiple testing error in RNA-seq data analysis. So far, there are very few proposals on sample size calculation for RNA-seq experiments. In this paper, we propose a procedure for sample size calculation while controlling FDR for RNA-seq experimental design. Our procedure is based on the weighted linear model analysis facilitated by the voom method which has been shown to have competitive performance in terms of power and FDR control for RNA-seq differential expression analysis. We derive a method that approximates the average power across the differentially expressed genes, and then calculate the sample size to achieve a desired average power while controlling FDR. Simulation results demonstrate that the actual power of several popularly applied tests for differential expression is achieved and is close to the desired power for RNA-seq data with sample size calculated based on our method. Our proposed method provides an efficient algorithm to calculate sample size while controlling FDR for RNA-seq experimental design. We also provide an R package ssizeRNA that implements our proposed method and can be downloaded from the Comprehensive R Archive Network ( http://cran.r-project.org ).
Global bioenergy capacity as constrained by observed biospheric productivity rates
NASA Astrophysics Data System (ADS)
Smith, W. K.; Zhao, M.; Running, S. W.
2011-12-01
Virtually all global energy forecasts include an expectation that bioenergy will be a substantial energy source for the future. Multiple current estimates of global bioenergy potential (GBP) range from 500-1,500 EJ yr-1 or 100-300% of 2009 global primary energy consumption (GPEC09), suggesting bioenergy could conceivably replace fossil fuels entirely. However, these estimates are based on extrapolation of plot-level production rates which largely neglect complex global climatic and land-use constraints. We estimated GBP using satellite-derived, observed global primary productivity data from 2000-2006, which integrates global climate data and detects seasonal vegetation dynamics. Land-use constraints were then applied to account for current crop and forestry harvest requirements, human-controlled pasturelands, remote regions, and nature conservation areas. We show GBP is limited to 52-248 EJ yr-1 or 10-49% of GPEC09, a range lower than many current GBP estimates by a factor of four. Even attaining the low-end of this range requires utilization of all harvest residues over 31 million km2 (Mkm2), while the high-end requires additional harvest over 41 Mkm2, an area roughly three times current global cropland extent. Although, exploitation of pasture and remote land could significantly contribute to GBP, the availability of these land areas remains controversial due to critical concerns regarding indirect land-use change and carbon debt. Future energy policy is of unparalleled importance to humanity, and our results are critical in estimating quantitative limitations on the overall potential for global bioenergy production.
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.
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.
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.
Change Rate Control of Photovoltaic Generation Output and Calculation of Necessary Capacitance
NASA Astrophysics Data System (ADS)
Satoh, Hiroyuki; Takayama, Satoshi; Nakamura, Koichi; Kakimoto, Naoto
The photovoltaic (PV) generator changes its power output with the weather. If the PV output changes fast, the power system may require more load-following capability and spinning-reserve. This paper proposes a method of controlling the change rate of the PV output. The PV generator is combined with an electric double layer capacitor (EDLC). The moving average is used to eliminate short period fluctuations of the PV output. The output of the power conversion system (PCS) is determined by the moving average. The output changes within a limited rate. The capacitor voltage is maintained at a constant value to make the capacitor as small as possible. The necessary capacitance is theoretically derived. The effectiveness of this method is verified by the experiment.
NASA Astrophysics Data System (ADS)
Kissinger, G.; Dabrowski, J.; Sinno, T.; Yang, Y.; Kot, D.; Sattler, A.
2017-06-01
Formation energies of vacancy clusters Vn with (1≤n≤11) in crystalline Si and of their complexes VnOm (1≤m≤14) with oxygen were computed by ab initio density functional theory (DFT) within the generalized gradient approximation (GGA) and used to simulate the process of vacancy agglomeration after rapid thermal annealing (RTA) and also the formation of bulk microdefects (BMDs) in Si. Rate equation modeling of vacancy agglomeration after RTA and subsequent annealing below 1000 °C was carried out and the results were compared for binding energies obtained with different cell size. In Czochralski silicon, the interaction between vacancies and interstitial oxygen has to be taken into account. The BMD formation in Czochralski silicon was modeled by a continuum model comprised of a large system of rate equations, which accounts for the free energy of BMDs as a function of BMD size and shape, temperature and point defect concentrations.
Variation in the production rate of biosonar signals in freshwater porpoises.
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.
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.
NASA Astrophysics Data System (ADS)
Wahnström, Göran; Carmeli, Benny; Metiu, Horia
1988-02-01
We propose and test a method for computing flux-flux correlation functions (and thermal rate coefficients) which divides the degrees of freedom in two groups, one treated classically and the other quantum mechanically. The method is tested by applying it to a simple model for which we can also obtain exact results. The approximate method gives good results if the mass associated with the classical degrees of freedom exceeds 16 a.u.
A simple method for calculating growth rates of petroleum hydrocarbon plumes
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.