Calculation of Design Parameters for an Equilibrium LEU Core in the NBSR
Hanson, A.L.; Diamond, D.
2011-09-30
A plan is being developed for the conversion of the NIST research reactor (NBSR) from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. Previously, the design of the LEU fuel had been determined in order to provide the users of the NBSR with the same cycle length as exists for the current HEU fueled reactor. The fuel composition at different points within an equilibrium fuel cycle had also been determined. In the present study, neutronics parameters have been calculated for these times in the fuel cycle for both the existing HEU and the proposed LEU equilibrium cores. The results showed differences between the HEU and LEU cores that would not lead to any significant changes in the safety analysis for the converted core. In general the changes were reasonable except that the figure-of-merit for neutrons that can be used by experimentalists shows there will be a 10% reduction in performance. The calculations included kinetics parameters, reactivity coefficients, reactivity worths of control elements and abnormal configurations, and power distributions.
NASA Technical Reports Server (NTRS)
Merchant, D. H.
1976-01-01
Methods are presented for calculating design limit loads compatible with probabilistic structural design criteria. The approach is based on the concept that the desired limit load, defined as the largest load occurring in a mission, is a random variable having a specific probability distribution which may be determined from extreme-value theory. The design limit load, defined as a particular of this random limit load, is the value conventionally used in structural design. Methods are presented for determining the limit load probability distributions from both time-domain and frequency-domain dynamic load simulations. Numerical demonstrations of the method are also presented.
Cook, J.M.
1995-07-01
Sands and Rees propose an electronic bench measurement of the impulse energy loss of a stored particle bunch to vacuum-chamber components. The components act as the outer conductor of a coaxial line with a thin wire as center conductor. Short pulses are then transmitted through this coaxial system to simulate relativistic particle bunches. Their proposal has since been implemented by several investigators and has become a well-known technique. They derive a first-order approximation to the loss parameter {kappa} for use in these measurements. The purpose of this note is to point out that exact expression for {kappa} is as simple as its first-order approximation and to recommend its use even when {kappa} is small.
NASA Astrophysics Data System (ADS)
Eckley, C. S.; Gustin, M.; Lin, C.-J.; Li, X.; Miller, M. B.
2010-01-01
Dynamic Flux Chambers (DFCs) are commonly applied for the measurement of non-point source mercury (Hg) emissions from a wide range of surfaces. A standard operating protocol and design for DFCs does not exist, and as a result there is a large diversity in methods described in the literature. Because natural and anthropogenic non-point sources are thought to contribute significantly to the atmosphere Hg pool, development of accurate fluxes during field campaigns is essential. The objective of this research was to determine how differences in chamber material, sample port placement, vertical cross sectional area/volume, and flushing flow rate influence the Hg flux from geologic materials. Hg fluxes measured with a Teflon chamber were higher than those obtained using a polycarbonate chamber, with differences related to light transmission and substrate type. Differences in sample port placement (side versus top) did not have an influence on Hg fluxes. When the same flushing flow rate was applied to two chambers of different volumes, higher fluxes were calculated for the chamber with the smaller volume. Conversely, when two chambers with different volumes were maintained at similar turnover times, the larger volume chamber yielded higher Hg fluxes. Overall, the flushing flow rate and associated chamber turnover time had the largest influence on Hg flux relative to the other parameters tested. Results from computational fluid dynamic (CFD) modeling inside a DFC confirm that the smaller diffusion resistance at higher flushing flows contributes to the higher measured flux. These results clearly illustrate that differences in chamber design and operation can significantly influence the resulting calculated Hg flux, and thus impact the comparability of results obtained using DFC designs and/or operating parameters. A protocol for determining a flushing flow rate that results in fluxes less affected by chamber operating conditions and design is proposed. Application of this
Hanson A. L.; Diamond D.
2014-06-30
A plan is being developed for the conversion of the NIST research reactor (NBSR) from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. The LEU fuel may be a monolithic foil (LEUm) of U10Mo (10% molybdenum by weight in an alloy with uranium) or a dispersion of U7Mo in aluminum (LEUd). A previous report provided neutronic calculations for the LEUm fuel and this report presents the neutronics parameters for the LEUd fuel. The neutronics parameters for the LEUd fuel are compared to those previously obtained for the present HEU fuel and the proposed LEUm fuel. The results show no significant differences between the LEUm and the LEUd other than the LEUd fuel requires slightly less uranium than the LEUm fuel due to less molybdenum being present. The calculations include kinetics parameters, reactivity coefficients, reactivity worths of control elements and abnormal configurations, and power distributions under normal operation and with misloaded fuel elements.
1989-03-01
Th usr a toente aninteer a thca sms b esta 1 Fp-ocsing 2. Enter P1 values, lwgt, ldig - > 9 Table I give us proper values. Table 1. PARAMETER TABLE...necessary and identify by block number) In this thesis a control systems analysis package is developed using parameter plane methods. It is an interactive...designer is able to choose values of the parameters which provide a good compromise between cost and dynamic behavior. 20 Distribution Availability of
Geoengineering design parameters workshop
St. John, C.M. and Associates, Grand Junction, CO ); Kim, Kunsoo . Rockwell Hanford Operations)
1985-12-12
A one-day workshop on the subject of the geotechnical design parameters, in situ stress and rock mass strength, for a nuclear waste repository in basalt was held in Rapid City, South Dakota, on June 25, 1989. A panel comprised of five widely recognized experts in the field of rock mechanics, met to discuss the state of stress at the Hanford Site and the strength of a basalt rock mass. This report summarizes the discussions that took place and presents a set of final position statements developed collaboratively by the panel and the workshop moderator. The report concludes with a set of specific recommendations for future actions considered necessary to adequately define the in situ stress and the rock mass strength at the Hanford Site and to document the position of the Basalt Waste Isolation Project in respect to these two critical design parameters.
Design Optimization Programmable Calculators versus Campus Computers.
ERIC Educational Resources Information Center
Savage, Michael
1982-01-01
A hypothetical design optimization problem and technical information on the three design parameters are presented. Although this nested iteration problem can be solved on a computer (flow diagram provided), this article suggests that several hand held calculators can be used to perform the same design iteration. (SK)
Calculation and Updating of Reliability Parameters in Probabilistic Safety Assessment
NASA Astrophysics Data System (ADS)
Zubair, Muhammad; Zhang, Zhijian; Khan, Salah Ud Din
2011-02-01
The internal events of nuclear power plant are complex and include equipment maintenance, equipment damage etc. These events will affect the probability of the current risk level of the system as well as the reliability of the equipment parameter values so such kind of events will serve as an important basis for systematic analysis and calculation. This paper presents a method for reliability parameters calculation and their updating. The method is based on binomial likelihood function and its conjugate beta distribution. For update parameters Bayes' theorem has been selected. To implement proposed method a computer base program is designed which provide help to estimate reliability parameters.
Closure and Sealing Design Calculation
T. Lahnalampi; J. Case
2005-08-26
The purpose of the ''Closure and Sealing Design Calculation'' is to illustrate closure and sealing methods for sealing shafts, ramps, and identify boreholes that require sealing in order to limit the potential of water infiltration. In addition, this calculation will provide a description of the magma that can reduce the consequences of an igneous event intersecting the repository. This calculation will also include a listing of the project requirements related to closure and sealing. The scope of this calculation is to: summarize applicable project requirements and codes relating to backfilling nonemplacement openings, removal of uncommitted materials from the subsurface, installation of drip shields, and erecting monuments; compile an inventory of boreholes that are found in the area of the subsurface repository; describe the magma bulkhead feature and location; and include figures for the proposed shaft and ramp seals. The objective of this calculation is to: categorize the boreholes for sealing by depth and proximity to the subsurface repository; develop drawing figures which show the location and geometry for the magma bulkhead; include the shaft seal figures and a proposed construction sequence; and include the ramp seal figure and a proposed construction sequence. The intent of this closure and sealing calculation is to support the License Application by providing a description of the closure and sealing methods for the Safety Analysis Report. The closure and sealing calculation will also provide input for Post Closure Activities by describing the location of the magma bulkhead. This calculation is limited to describing the final configuration of the sealing and backfill systems for the underground area. The methods and procedures used to place the backfill and remove uncommitted materials (such as concrete) from the repository and detailed design of the magma bulkhead will be the subject of separate analyses or calculations. Post-closure monitoring will not
Calculation of Kinetics Parameters for the NBSR
Hanson A. L.; Diamond D.
2012-03-06
The delayed neutron fraction and prompt neutron lifetime have been calculated at different times in the fuel cycle for the NBSR when fueled with both high-enriched uranium (HEU) and low-enriched uranium (LEU) fuel. The best-estimate values for both the delayed neutron fraction and the prompt neutron lifetime are the result of calculations using MCNP5-1.60 with the most recent ENDFB-VII evaluations. The best-estimate values for the total delayed neutron fraction from fission products are 0.00665 and 0.00661 for the HEU fueled core at startup and end-of-cycle, respectively. For the LEU fuel the best estimate values are 0.00650 and 0.00648 at startup and end-of-cycle, respectively. The present recommendations for the delayed neutron fractions from fission products are smaller than the value reported previously of 0.00726 for the HEU fuel. The best-estimate values for the contribution from photoneutrons will remain as 0.000316, independent of the fuel or time in the cycle.The values of the prompt neutron lifetime as calculated with MCNP5-1.60 are compared to values calculated with two other independent methods and the results are in reasonable agreement with each other. The recommended, conservative values of the neutron lifetime for the HEU fuel are 650 {micro}s and 750 {micro}s for the startup and end-of-cycle conditions, respectively. For LEU fuel the recommended, conservative values are 600 {micro}s and 700 {micro}s for the startup and end-of-cycle conditions, respectively. In all three calculations, the prompt neutron lifetime was determined to be longer for the end-of-cycle equilibrium condition when compared to the startup condition. The results of the three analyses were in agreement that the LEU fuel will exhibit a shorter prompt neutron lifetime when compared to the HEU fuel.
Design Calculations for NIF Convergent Ablator Experiments
NASA Astrophysics Data System (ADS)
Olson, R. E.; Callahan, D. A.; Hicks, D. G.; Landen, O. L.; Langer, S. H.; Meezan, N. B.; Spears, B. K.; Widmann, K.; Kline, J. L.; Wilson, D. C.; Petrasso, R. D.; Leeper, R. J.
2010-11-01
Design calculations for NIF convergent ablator experiments will be described. The convergent ablator experiments measure the implosion trajectory, velocity, and ablation rate of an x-ray driven capsule and are a important component of the U. S. National Ignition Campaign at NIF. The design calculations are post-processed to provide simulations of the key diagnostics -- 1) Dante measurements of hohlraum x-ray flux and spectrum, 2) streaked radiographs of the imploding ablator shell, 3) wedge range filter measurements of D-He3 proton output spectra, and 4) GXD measurements of the imploded core. The simulated diagnostics will be compared to the experimental measurements to provide an assessment of the accuracy of the design code predictions of hohlraum radiation temperature, capsule ablation rate, implosion velocity, shock flash areal density, and x-ray bang time. Post-shot versions of the design calculations are used to enhance the understanding of the experimental measurements and will assist in choosing parameters for subsequent shots and the path towards optimal ignition capsule tuning. *SNL, LLNL, and LANL are operated under US DOE contracts DE-AC04-94AL85000. DE-AC52-07NA27344, and DE-AC04-94AL85000.
[Calculation of parameters in forest evapotranspiration model].
Wang, Anzhi; Pei, Tiefan
2003-12-01
Forest evapotranspiration is an important component not only in water balance, but also in energy balance. It is a great demand for the development of forest hydrology and forest meteorology to simulate the forest evapotranspiration accurately, which is also a theoretical basis for the management and utilization of water resources and forest ecosystem. Taking the broadleaved Korean pine forest on Changbai Mountain as an example, this paper constructed a mechanism model for estimating forest evapotranspiration, based on the aerodynamic principle and energy balance equation. Using the data measured by the Routine Meteorological Measurement System and Open-Path Eddy Covariance Measurement System mounted on the tower in the broadleaved Korean pine forest, the parameters displacement height d, stability functions for momentum phi m, and stability functions for heat phi h were ascertained. The displacement height of the study site was equal to 17.8 m, near to the mean canopy height, and the functions of phi m and phi h changing with gradient Richarson number R i were constructed.
Image Texture Dependence Upon Sensing and Calculation Parameters
NASA Astrophysics Data System (ADS)
Rodionova, N. V.
2013-08-01
This paper analyzes various parameters influence on the textural properties of digital remote sensing images using the statistical method of texture description (grey-level co-occurrence matrix (GLCM)). The parameters may be grouped to external (primary) parameters determined by surface and sensor characteristics (radar frequency, polarization, speckle filtering, spatial and radiometric resolution of the sensor, multispectral (MS) band, etc.), and internal (secondary) parameters determined by the texture calculation algorithm.SAR, MS and panchromatic images are used for illustration.
Structural Design Parameters for Germanium
NASA Technical Reports Server (NTRS)
Salem, Jon; Rogers, Richard; Baker, Eric
2017-01-01
The fracture toughness and slow crack growth parameters of germanium supplied as single crystal beams and coarse grain disks were measured. Although germanium is anisotropic (A* 1.7), it is not as anisotropic as SiC, NiAl, or Cu. Thus the fracture toughness was similar on the 100, 110, and 111 planes, however, measurements associated with randomly oriented grinding cracks were 6 to 30 higher. Crack extension in ring loaded disks occurred on the 111 planes due to both the lower fracture energy and the higher stresses on stiff 111 planes. Germanium exhibits a Weibull scale effect, but does not exhibit significant slow crack growth in distilled water. (n 100), implying that design for quasi static loading can be performed with scaled strength statistics. Practical values for engineering design are a fracture toughness of 0.69 0.02 MPam (megapascals per square root meter) and a Weibull modulus of m 6 2. For well ground and reasonable handled coupons, average fracture strength should be greater than 40 megapascals. Aggregate, polycrystalline elastic constants are Epoly 131 gigapascals, vpoly 0.22.
Calculator program speeds rod pump design
Engineer, R.; Davis, C.L.
1984-02-01
Matching sucker rod pump characteristics to a specific application is greatly simplified with this program, intended for use with an HP-41CV hand-held computer. The user inputs application data and the program calculates all necessary design criteria, including Mill's acceleration factor, peak and minimum polish rod loads and horsepower required. Sample calculations are provided, together with a thorough discussion of special design considerations involved in huff-and-puff applications.
Balloon Thermal Model Design Parameters and Sensitivities
NASA Technical Reports Server (NTRS)
Ferguson, Douglas
2017-01-01
This presentation describes the thought process for determining balloon thermal model design parameters, including environmental parameters taken form NASA's top-of-atmosphere (TOA) database, and shows the sensitivity of an example model's key temperature results to those input parameters.
Design calculations for the ANS (Advanced Neutron Source) cold source
Lillie, R.A.; Alsmiller, R.G. Jr.
1988-01-01
The calculation procedure, based on discrete ordinates transport methods, that is being used to carry out design calculations for the Advanced Neutron Source cold source is described. Calculated results on the gain in cold neutron flux produced by a liquid deuterium cold source are compared with experimental data and with calculated data previously obtained by P. Ageron et al., at the Institute Max von Laue-Paul Langevin in Grenoble, France. Calculated results are also presented that indicated how the flux of cold neutrons vary with cold source parameters. 23 refs., 5 figs., 3 tabs.
Microbial Communities Model Parameter Calculation for TSPA/SR
D. Jolley
2001-07-16
This calculation has several purposes. First the calculation reduces the information contained in ''Committed Materials in Repository Drifts'' (BSC 2001a) to useable parameters required as input to MING V1.O (CRWMS M&O 1998, CSCI 30018 V1.O) for calculation of the effects of potential in-drift microbial communities as part of the microbial communities model. The calculation is intended to replace the parameters found in Attachment II of the current In-Drift Microbial Communities Model revision (CRWMS M&O 2000c) with the exception of Section 11-5.3. Second, this calculation provides the information necessary to supercede the following DTN: M09909SPAMING1.003 and replace it with a new qualified dataset (see Table 6.2-1). The purpose of this calculation is to create the revised qualified parameter input for MING that will allow {Delta}G (Gibbs Free Energy) to be corrected for long-term changes to the temperature of the near-field environment. Calculated herein are the quadratic or second order regression relationships that are used in the energy limiting calculations to potential growth of microbial communities in the in-drift geochemical environment. Third, the calculation performs an impact review of a new DTN: M00012MAJIONIS.000 that is intended to replace the currently cited DTN: GS9809083 12322.008 for water chemistry data used in the current ''In-Drift Microbial Communities Model'' revision (CRWMS M&O 2000c). Finally, the calculation updates the material lifetimes reported on Table 32 in section 6.5.2.3 of the ''In-Drift Microbial Communities'' AMR (CRWMS M&O 2000c) based on the inputs reported in BSC (2001a). Changes include adding new specified materials and updating old materials information that has changed.
Dissipative Particle Dynamics interaction parameters from ab initio calculations
NASA Astrophysics Data System (ADS)
Sepehr, Fatemeh; Paddison, Stephen J.
2016-02-01
Dissipative Particle Dynamics (DPD) is a commonly employed coarse-grained method to model complex systems. Presented here is a pragmatic approach to connect atomic-scale information to the meso-scale interactions defined between the DPD particles or beads. Specifically, electronic structure calculations were utilized for the calculation of the DPD pair-wise interaction parameters. An implicit treatment of the electrostatic interactions for charged beads is introduced. The method is successfully applied to derive the parameters for a hydrated perfluorosulfonic acid ionomer with absorbed vanadium cations.
Calculation of optimal parameters for 19F MRI
NASA Astrophysics Data System (ADS)
Anisimov, N.; Gulaev, M.; Pavlova, O.; Fomina, D.; Glukhova, V.; Batova, S.; Pirogov, Yu
2017-08-01
This paper presents a method for optimizing the parameters of the scanning pulse sequences for MRI in relation to objects with a wide NMR spectrum. In this case, a broadband excitation of the spin system is difficult because of hardware limitations. It is proposed to apply the selective excitation, the optimum parameters of which are calculated by an algorithm that uses information concerning the NMR spectrum. The method is especially useful for 19F MRI of fluorocarbons.
Heat Exchanger Support Bracket Design Calculations
Rucinski, Russ; /Fermilab
1995-01-12
This engineering note documents the design of the heat exchanger support brackets. The heat exchanger is roughly 40 feet long, 22 inches in diameter and weighs 6750 pounds. It will be mounted on two identical support brackets that are anchored to a concrete wall. The design calculations were done for one bracket supporting the full weight of the heat exchanger, rounded up to 6800 pounds. The design follows the American Institute of Steel Construction (AISC) Manual of steel construction, Eighth edition. All calculated stresses and loads on welds were below allowables.
Extended Hansen approach: calculating partial solubility parameters of solid solutes.
Wu, P L; Beerbower, A; Martin, A
1982-11-01
A multiple linear regression method, known as the extended Hansen solubility approach, was used to estimate the partial solubility parameters, delta d, delta p, and delta h for crystalline solutes. The method is useful, since organic compounds may decompose near their melting points, and it is not possible, to determine solubility parameters for these solid compounds by the methods used for liquid solvents. The method gives good partial and total solubility parameters for naphthalene; with related compounds, less satisfactory results were obtained. At least three conditions, pertaining to the regression equation and the solvent systems, must be met in order to obtain reasonable solute solubility parameters. In addition to providing partial solubility parameters, the regression equations afford a calculation of solute solubility in both polar and nonpolar solvents.
Program Calculates Power Demands Of Electronic Designs
NASA Technical Reports Server (NTRS)
Cox, Brian
1995-01-01
CURRENT computer program calculates power requirements of electronic designs. For given design, CURRENT reads in applicable parts-list file and file containing current required for each part. Program also calculates power required for circuit at supply potentials of 5.5, 5.0, and 4.5 volts. Written by use of AWK utility for Sun4-series computers running SunOS 4.x and IBM PC-series and compatible computers running MS-DOS. Sun version of program (NPO-19590). PC version of program (NPO-19111).
Program Calculates Power Demands Of Electronic Designs
NASA Technical Reports Server (NTRS)
Cox, Brian
1995-01-01
CURRENT computer program calculates power requirements of electronic designs. For given design, CURRENT reads in applicable parts-list file and file containing current required for each part. Program also calculates power required for circuit at supply potentials of 5.5, 5.0, and 4.5 volts. Written by use of AWK utility for Sun4-series computers running SunOS 4.x and IBM PC-series and compatible computers running MS-DOS. Sun version of program (NPO-19590). PC version of program (NPO-19111).
Calculator program helps set offshore design criteria
Tran, V.B.
1983-01-10
Describes a new program for the Hewlett-Packard HP 41C (or HP-41C) hand-held programmable calculator which predicts the design criteria for building offshore facilities. Points out that the ''wind and wave'' (WIWA) program can quickly provide the calculations necessary for proper design involving wind forces, wave forces, and stress acting on the hydrostatic pressure case of a submerged system. Presents a flow diagram of the program and the program listing. Explains the equations used as the basis of the program.
On the Relationships Between the Fundamental Parameters of Calculation Accelerograms
Savich, A. I. Burdina, N. A.
2016-05-15
Analysis of published data on the fundamental parameters of actual accelerograms of strong earthquakes having peak ground acceleration A{sub max}, predominant period T{sub pr}, and duration τ{sub 0.5} at 0.5A{sub max} determined that, for earthquakes of intensity greater than 6.5 – 7.0, the relationship between these quantities is sufficiently well described by the parameters B = ATτ and C = AτT{sup −1.338}, the former of which depends little on earthquake intensity I and is almost completely determined by the earthquake magnitude, while the latter, on the contrary, weakly depends on magnitude and is determined principally by the quantity I. Methods are proposed for using the parameters B and C to improve the reliability of determining parameters of accelerograms used to calculate the seismic resistance of hydraulic engineering facilities.
Theoretical calculations of EPR parameters of gas phase hydracrylonitrile radical
NASA Astrophysics Data System (ADS)
Sarikaya, Ebru Karakaş; Dereli, Ömer
2017-02-01
As a result of detailed conformational search of the hydracrylonitrile, four different conformers of molecule have been obtained. For these conformations, eleven possible radicals were modelled by using density functional theory (DFT) computations with respect to molecular structure. Electron Paramagnetic Resonance parameters of these model radicals were calculated and then they were compared with the experimental ones. Geometry optimizations of the molecule and modeled radicals were calculated by B3LYP method using 6-311++G(d,p) basis sets in gas phase.
Parameter-Free Quasiparticle Calculations for YH3
NASA Astrophysics Data System (ADS)
van Gelderen, P.; Bobbert, P. A.; Kelly, P. J.; Brocks, G.
2000-10-01
Electronic structure calculations for YH3 within the local density approximation result in a metallic ground state with the bands at the Fermi energy overlapping by more than 1 eV, whereas a band gap of 2.8 eV is deduced from optical experiments. Here, we report the results of parameter-free GW calculations which predict a fundamental gap of 1 eV. When we take into account electric dipole matrix elements a large optical gap of almost 3 eV is obtained. A combination of photoemission and inverse photoemission spectroscopy could test the prediction of a small fundamental band gap.
Star Tracker/Mapper: System Design Parameters
1974-09-01
AD-A008 554 STAR TRACKER/MAPPER: SYSTEM’DESIGN PARAMETERS F. W. Schenkel Johns Hopkins University Prepared for: Naval Plant Representative Office...APLIJHU TG 1256 4. TITLE (andSubritle) 5. TYPE OF REPORT & PERIOD COVERED Star Tracker/Mapper: System Design Parameters 6. PERFORMING ORG. REPORT...identify by block number) Design parameters Star tracker/mapper Optical sensors Optical trackers Spectral characteristics 20. ABSTRACT (Continue on
HOM study and parameter calculation of the TESLA cavity model
NASA Astrophysics Data System (ADS)
Zeng, Ri-Hua; Schuh, Marcel; Gerigk, Frank; Wegner, Rolf; Pan, Wei-Min; Wang, Guang-Wei; Liu, Rong
2010-01-01
The Superconducting Proton Linac (SPL) is the project for a superconducting, high current H-accelerator at CERN. To find dangerous higher order modes (HOMs) in the SPL superconducting cavities, simulation and analysis for the cavity model using simulation tools are necessary. The existing TESLA 9-cell cavity geometry data have been used for the initial construction of the models in HFSS. Monopole, dipole and quadrupole modes have been obtained by applying different symmetry boundaries on various cavity models. In calculation, scripting language in HFSS was used to create scripts to automatically calculate the parameters of modes in these cavity models (these scripts are also available in other cavities with different cell numbers and geometric structures). The results calculated automatically are then compared with the values given in the TESLA paper. The optimized cavity model with the minimum error will be taken as the base for further simulation of the SPL cavities.
[Program for the calculation of several contractility parameters on a micro-calculator].
Güttler, P
1975-01-15
In order to determine the valency of different parameters of contractility, these shall be compared on certain conditions in the animal experiment. For this is necessary the evaluation of a large number of pressure curves of the left ventricle. When a micro-calculating-machine is present, this can carry out the evaluation, the course of the pressure which is to be evaluated is only to be given into the calculating machine punctually. The paper describes a programme for the hp-micro-calculating-machine 9810 A.
Sample size calculations for prevalent cohort designs.
Liu, Hao; Shen, Yu; Ning, Jing; Qin, Jing
2017-02-01
Cross-sectional prevalent cohort design has drawn considerable interests in the studies of association between risk factors and time-to-event outcome. The sampling scheme in such design gives rise to length-biased data that require specialized analysis strategy but can improve study efficiency. The power and sample size calculation methods are however lacking for studies with prevalent cohort design, and using the formula developed for traditional survival data may overestimate sample size. We derive the sample size formulas that are appropriate for the design of cross-sectional prevalent cohort studies, under the assumptions of exponentially distributed event time and uniform follow-up for cross-sectional prevalent cohort design. We perform numerical and simulation studies to compare the sample size requirements for achieving the same power between prevalent cohort and incident cohort designs. We also use a large prospective prevalent cohort study to demonstrate the procedure. Using rigorous designs and proper analysis tools, the prospective prevalent cohort design can be more efficient than the incident cohort design with the same total sample sizes and study durations.
Calculating small interchain exchange parameters in Copper Pyrazine Dinitrate
NASA Astrophysics Data System (ADS)
Thomas, Iorwerth; Clark, Stewart; Lancaster, Tom
The coordination polymer copper pyrazine dinitrate (Cu(pyz)(NO3)2) is a one-dimensional antiferromagnet that undergoes a magnetic phase transition to a state of long-range three dimensional magnetic order (LRO) below a temperature of 110 mK. The precise nature of the LRO is dependent on the strength of interchain interactions, which are very weak compared to the dominant superexchange interaction along the chain. It is therefore possible that different approaches to ab initio calculations of exchange interaction parameters may be subject to small systematic effects that would lead to erroneous results. In order to investigate whether such a problem arises in this case, we use the GGA+U approach to Density Functional Theory to compare the results obtained by two methods of calculating these parameters: the dimer fragment approach and the periodic method, and relate them to both experiment and previous calculations performed using the hybrid approach. Supported by the Templeton Foundation as part of the Durham Emergence Project.
Design Criteria for Low Profile Flange Calculations
NASA Technical Reports Server (NTRS)
Leimbach, K. R.
1973-01-01
An analytical method and a design procedure to develop flanged separable pipe connectors are discussed. A previously established algorithm is the basis for calculating low profile flanges. The characteristics and advantages of the low profile flange are analyzed. The use of aluminum, titanium, and plastics for flange materials is described. Mathematical models are developed to show the mechanical properties of various flange configurations. A computer program for determining the structural stability of the flanges is described.
Computer program for calculating flow parameters and power requirements for cryogenic wind tunnels
NASA Technical Reports Server (NTRS)
Dress, D. A.
1985-01-01
A computer program has been written that performs the flow parameter calculations for cryogenic wind tunnels which use nitrogen as a test gas. The flow parameters calculated include static pressure, static temperature, compressibility factor, ratio of specific heats, dynamic viscosity, total and static density, velocity, dynamic pressure, mass-flow rate, and Reynolds number. Simplifying assumptions have been made so that the calculations of Reynolds number, as well as the other flow parameters can be made on relatively small desktop digital computers. The program, which also includes various power calculations, has been developed to the point where it has become a very useful tool for the users and possible future designers of fan-driven continuous-flow cryogenic wind tunnels.
WIPP shaft seal system parameters recommended to support compliance calculations
Hurtado, L.D.; Knowles, M.K.; Kelley, V.A.; Jones, T.L.; Ogintz, J.B.; Pfeifle, T.W.
1997-12-01
The US Department of Energy plans to dispose of transuranic waste at the Waste Isolation Pilot Plant (WIPP), which is sited in southeastern New Mexico. The WIPP disposal facility is located approximately 2,150 feet (650 m) below surface in the bedded halite of the Salado Formation. Prior to initiation of disposal activities, the Department of Energy must demonstrate that the WIPP will comply with all regulatory requirements. Applicable regulations require that contaminant releases from the WIPP remain below specified levels for a period of 10,000 years. To demonstrate that the WIPP will comply with these regulations, the Department of Energy has requested that Sandia National Laboratories develop and implement a comprehensive performance assessment of the WIPP repository for the regulatory period. This document presents the conceptual model of the shaft sealing system to be implemented in performance assessment calculations conducted in support of the Compliance Certification Application for the WIPP. The model was developed for use in repository-scale calculations and includes the seal system geometry and materials to be used in grid development as well as all parameters needed to describe the seal materials. These calculations predict the hydrologic behavior of the system. Hence conceptual model development is limited to those processes that could impact the fluid flow through the seal system.
Kujawski, E.; Weisbin, C.R.
1982-01-01
This chapter considers the calculational methodology and associated uncertainties both for the design of large LMFBR's and the analysis of critical assemblies (fast critical experiments) as performed by several groups within the US. Discusses cross-section processing; calculational methodology for the design problem; core physics computations; design-oriented approximations; benchmark analyses; and determination of calculational corrections and associated uncertainties for a critical assembly. Presents a detailed analysis of the sources of calculational uncertainties for the critical assembly ZPR-6/7 to illustrate the quantitative assessment of calculational correction factors and uncertainties. Examines calculational uncertainties that arise from many different sources including intrinsic limitations of computational methods; design-oriented approximations related to reactor modeling; computational capability and code availability; economic limitations; and the skill of the reactor analyst. Emphasizes that the actual design uncertainties in most of the parameters, with the possible exception of burnup, are likely to be less than might be indicated by the results presented in this chapter because reactor designers routinely apply bias factors (usually derived from critical experiments) to their calculated results.
Design parameters for rotary extrusion macerators
Nelson, F.W.; Barrington, G.P.; Straub, R.J.; Bruhn, H.D.
1981-01-01
Design parameters for an extrusion macerator for plant juice protein extraction are discussed. Forces developed can be predicted for various machine configurations, throughputs, speeds, and extrusion pressures from a simple nomogram. 5 refs.
A Multi-Parameter Approach for Calculating Crack Instability
NASA Technical Reports Server (NTRS)
Zanganeh, M.; Forman, R. G.
2014-01-01
An accurate fracture control analysis of spacecraft pressure systems, boosters, rocket hardware and other critical low-cycle fatigue cases where the fracture toughness highly impacts cycles to failure requires accurate knowledge of the material fracture toughness. However, applicability of the measured fracture toughness values using standard specimens and transferability of the values to crack instability analysis of the realistically complex structures is refutable. The commonly used single parameter Linear Elastic Fracture Mechanics (LEFM) approach which relies on the key assumption that the fracture toughness is a material property would result in inaccurate crack instability predictions. In the past years extensive studies have been conducted to improve the single parameter (K-controlled) LEFM by introducing parameters accounting for the geometry or in-plane constraint effects]. Despite the importance of the thickness (out-of-plane constraint) effects in fracture control problems, the literature is mainly limited to some empirical equations for scaling the fracture toughness data] and only few theoretically based developments can be found. In aerospace hardware where the structure might have only one life cycle and weight reduction is crucial, reducing the design margin of safety by decreasing the uncertainty involved in fracture toughness evaluations would result in lighter hardware. In such conditions LEFM would not suffice and an elastic-plastic analysis would be vital. Multi-parameter elastic plastic crack tip field quantifying developments combined with statistical methods] have been shown to have the potential to be used as a powerful tool for tackling such problems. However, these approaches have not been comprehensively scrutinized using experimental tests. Therefore, in this paper a multi-parameter elastic-plastic approach has been used to study the crack instability problem and the transferability issue by considering the effects of geometrical
Electronic structure calculations of ESR parameters of melanin units.
Batagin-Neto, Augusto; Bronze-Uhle, Erika Soares; Graeff, Carlos Frederico de Oliveira
2015-03-21
Melanins represent an important class of natural pigments present in plants and animals that are currently considered to be promising materials for applications in optic and electronic devices. Despite their interesting properties, some of the basic features of melanins are not satisfactorily understood, including the origin of their intrinsic paramagnetism. A number of experiments have been performed to investigate the electron spin resonance (ESR) response of melanin derivatives, but until now, there has been no consensus regarding the real structure of the paramagnetic centers involved. In this work, we have employed electronic structure calculations to evaluate the ESR parameters of distinct melanin monomers and dimers in order to identify the possible structures associated with unpaired spins in this biopolymer. The g-factors and hyperfine constants of the cationic, anionic and radicalar structures were investigated. The results confirm the existence of at least two distinct paramagnetic centers in melanin structure, identifying the chemical species associated with them and their roles in electrical conductivity.
Brachytherapy dosimetry parameters calculated for a 131Cs source.
Rivard, Mark J
2007-02-01
A comprehensive analysis of the IsoRay Medical model CS-1 Rev2 131Cs brachytherapy source was performed. Dose distributions were simulated using Monte Carlo methods (MCNP5) in liquid water, Solid Water, and Virtual Water spherical phantoms. From these results, the in-water brachytherapy dosimetry parameters have been determined, and were compared with those of Murphy et al. [Med. Phys. 31, 1529-1538 (2004)] using measurements and simulations. Our results suggest that calculations obtained using erroneous cross-section libraries should be discarded as recommended by the 2004 AAPM TG-43U1 report. Our Mclambda value of 1.046+/-0.019 cGy h(-1) U(-1) is within 1.3% of that measured by Chen et al. [Med. Phys. 32, 3279-3285 (2005)] using TLDs and the calculated results of Wittman and Fisher [Med. Phys. 34, 49-54 (2007)] using MCNP5. Using the discretized energy approach of Rivard [Appl. Radiat. Isot. 55, 775-782 (2001)] to ascertain the impact of individual 131Cs photons on radial dose function and anisotropy functions, there was virtual equivalence of results for 29.461< or =Egamma< or = 34.419 keV and for a mono-energetic 30.384 keV photon source. Comparisons of radial dose function and 2D anisotropy function data are also included, and an analysis of material composition and cross-section libraries was performed.
Design parameters of toroidal and bobbin magnetics
NASA Technical Reports Server (NTRS)
Mclyman, W. T.
1973-01-01
The adoption by NASA of the metric system for dimensioning to replace the long-used English units imposes a requirement on the U.S. transformer designer to convert from the familiar units to the less familiar metric equivalents. Material is presented to assist in that transition in the field of transformer design and fabrication. The conversion data makes it possible for the designer to obtain a fast and close approximation of significant parameters such as size, weight, and temperature rise. Nomographs are included to provide a close approximation for breadboarding purposes. For greater convenience, derivations of some of the parameters are also presented.
Design Parameters in Multimodal Games for Rehabilitation
Basteris, Angelo; Amirabdollahian, Farshid
2014-01-01
Abstract Objectives: The repetitive and sometimes mundane nature of conventional rehabilitation therapy provides an ideal opportunity for development of interactive and challenging therapeutic games that have the potential to engage and motivate the players. Certain game design parameters that may encourage patients to actively participate by making the games more enjoyable have been identified. In this article, we describe a formative study in which we designed and evaluated some of these parameters with healthy subjects. Materials and Methods: The “operant conditioning” and “scoring” design parameters were incorporated in a remake of a classic labyrinth game, “Marble Maze.” A group of participants (n=37) played the game twice: Once in the control condition without both modalities and then with either one of the parameters or with both. Measures of game duration and number of fails in the game were recorded along with survey questionnaires to measure player perceptions of intrinsic motivation on the game. Results: Longer playtimes, higher levels of interest/enjoyment, and effort to play the game were recorded with the introduction of these parameters. Conclusions: This study provides an understanding on how game design parameters can be used to motivate and encourage people to play longer. With these positive results, future aims are to test the parameters with stroke patients, providing much clearer insight as to what influences these parameters have on patients undergoing therapy. The ultimate goal is to utilize game design in order to maintain longer therapeutic interaction between a patient and his or her therapy medium. PMID:24761328
Optimal design criteria - prediction vs. parameter estimation
NASA Astrophysics Data System (ADS)
Waldl, Helmut
2014-05-01
G-optimality is a popular design criterion for optimal prediction, it tries to minimize the kriging variance over the whole design region. A G-optimal design minimizes the maximum variance of all predicted values. If we use kriging methods for prediction it is self-evident to use the kriging variance as a measure of uncertainty for the estimates. Though the computation of the kriging variance and even more the computation of the empirical kriging variance is computationally very costly and finding the maximum kriging variance in high-dimensional regions can be time demanding such that we cannot really find the G-optimal design with nowadays available computer equipment in practice. We cannot always avoid this problem by using space-filling designs because small designs that minimize the empirical kriging variance are often non-space-filling. D-optimality is the design criterion related to parameter estimation. A D-optimal design maximizes the determinant of the information matrix of the estimates. D-optimality in terms of trend parameter estimation and D-optimality in terms of covariance parameter estimation yield basically different designs. The Pareto frontier of these two competing determinant criteria corresponds with designs that perform well under both criteria. Under certain conditions searching the G-optimal design on the above Pareto frontier yields almost as good results as searching the G-optimal design in the whole design region. In doing so the maximum of the empirical kriging variance has to be computed only a few times though. The method is demonstrated by means of a computer simulation experiment based on data provided by the Belgian institute Management Unit of the North Sea Mathematical Models (MUMM) that describe the evolution of inorganic and organic carbon and nutrients, phytoplankton, bacteria and zooplankton in the Southern Bight of the North Sea.
Two space scatterer formalism calculation of bulk parameters of thunderclouds
NASA Technical Reports Server (NTRS)
Phanord, Dieudonne D.
1994-01-01
In a previous study, we used a modified two-space scatterer formalism of Twersky to establish for a cloud modeled as a statistically homogeneous distribution of spherical water droplets, the dispersion relations that determine its bulk propagation numbers and bulk indexes of refraction in terms of the vector equivalent scattering amplitude and the dyadic scattering amplitude of the single water droplet in isolation. The results were specialized to the forward direction of scattering while demanding that the scatterers preserve the incident polarization. We apply this approach to obtain specific numerical values for the macroscopic parameters of the cloud. We work with a cloud of density rho = 100 cm(exp -3), a wavelength lambda = 0.7774 microns, and with spherical water droplets of common radius alpha = 10 microns. In addition, the scattering medium is divided into three parts, the medium outside the cloud, moist air (the medium inside the cloud but outside the droplets), and the medium inside the spherical water droplets. The results of this report are applicable to a cloud of any geometry since the boundary does not interfere with the calculations. Also, it is important to notice the plane wave nature of the incidence wave in the moist atmosphere.
Laurent, M
1980-01-01
Two programs calculating oxygen transport parameters and hemodynamic values respectively are described. They may be used indifferently with HP 67 or HP 97 Hewlett Packard calculators. (Acta anaesth. belg., 1980, 31, 53-59).
Design parameters for wearable optical imagers
NASA Astrophysics Data System (ADS)
Akin, Ata; Kim, Sanghyun; Pourrezaei, Kambiz; Chance, Britton; Nioka, Shoko
2001-06-01
This paper summarizes the design steps that are followed during the development of the portable optical imager for breast cancer screening. The design steps considered the parameters such as total power consumption versus battery weight and size, speed of data acquisition versus cost and complexity of the design (functionality), graphical display versus operating system choice. We have used a single board computer system that uses Windows CE as the real time operating system. This choice was preferred since our graphical display requirements can only be carried out with the CE environment's GUI kernels.
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.
Aerodynamics as a subway design parameter
NASA Technical Reports Server (NTRS)
Kurtz, D. W.
1976-01-01
A parametric sensitivity study has been performed on the system operational energy requirement in order to guide subway design strategy. Aerodynamics can play a dominant or trivial role, depending upon the system characteristics. Optimization of the aerodynamic parameters may not minimize the total operational energy. Isolation of the station box from the tunnel and reduction of the inertial power requirements pay the largest dividends in terms of the operational energy requirement.
Continuous damage parameter calculation under thermo-mechanical random loading.
Nagode, Marko
2014-01-01
The paper presents a method on how the mean stress effect on fatigue damage can be taken into account under an arbitrary low cycle thermo-mechanical loading. From known stress, elastoplastic strain and temperature histories the cycle amplitudes and cycle mean values are extracted and the damage parameter is computed. In contrast to the existing methods the proposed method enables continuous damage parameter computation without the need of waiting for the cycles to close. The limitations of the standardized damage parameters are thus surpassed. The damage parameters derived initially for closed and isothermal cycles assuming that the elastoplastic stress-strain response follows the Masing and memory rules can now be used to take the mean stress effect into account under an arbitrary low cycle thermo-mechanical loading. The method includes:•stress and elastoplastic strain history transformation into the corresponding amplitude and mean values;•stress and elastoplastic strain amplitude and mean value transformation into the damage parameter amplitude history;•damage parameter amplitude history transformation into the damage parameter history.
Continuous damage parameter calculation under thermo-mechanical random loading
Nagode, Marko
2014-01-01
The paper presents a method on how the mean stress effect on fatigue damage can be taken into account under an arbitrary low cycle thermo-mechanical loading. From known stress, elastoplastic strain and temperature histories the cycle amplitudes and cycle mean values are extracted and the damage parameter is computed. In contrast to the existing methods the proposed method enables continuous damage parameter computation without the need of waiting for the cycles to close. The limitations of the standardized damage parameters are thus surpassed. The damage parameters derived initially for closed and isothermal cycles assuming that the elastoplastic stress–strain response follows the Masing and memory rules can now be used to take the mean stress effect into account under an arbitrary low cycle thermo-mechanical loading. The method includes:•stress and elastoplastic strain history transformation into the corresponding amplitude and mean values;•stress and elastoplastic strain amplitude and mean value transformation into the damage parameter amplitude history;•damage parameter amplitude history transformation into the damage parameter history. PMID:26150939
Design sensitivity analysis using EAL. Part 2: Shape design parameters
NASA Technical Reports Server (NTRS)
Dopker, B.; Choi, Kyung K.
1986-01-01
A numerical implementation of shape design sensitivity analysis of built-up structures is presented, using the versatility and convenience of an existing finite element structural analysis code and its data base management system. This report is a continuation of a previous report on conventional design parameters. The finite element code used in the implementation presented is the Engineering Analysis Language (EAL), which is based on a hybrid analysis method. It has been shown that shape design sensitivity computations can be carried out using the database management system of EAL, without writing a separate program and a separate data base. The material derivative concept of continuum mechanics and an adjoint variable method of design sensitivity analysis are used to derive shape design sensitivity information of structural performances. A domain method of shape design sensitivity analysis and a design component method are used. Displacement and stress functionals are considered as performance criteria.
Seismic design parameters - A user guide
Leyendecker, E.V.; Frankel, A.D.; Rukstales, K.S.
2001-01-01
The 1997 NEHRP Recommended Provisions for Seismic Regulations for New Buildings (1997 NEHRP Provisions) introduced seismic design procedure that is based on the explicit use of spectral response acceleration rather than the traditional peak ground acceleration and/or peak ground velocity or zone factors. The spectral response accelerations are obtained from spectral response acceleration maps accompanying the report. Maps are available for the United States and a number of U.S. territories. Since 1997 additional codes and standards have also adopted seismic design approaches based on the same procedure used in the NEHRP Provisions and the accompanying maps. The design documents using the 1997 NEHRP Provisions procedure may be divided into three categories -(1) Design of New Construction, (2) Design and Evaluation of Existing Construction, and (3) Design of Residential Construction. A CD-ROM has been prepared for use in conjunction with the design documents in each of these three categories. The spectral accelerations obtained using the software on the CD are the same as those that would be obtained by using the maps accompanying the design documents. The software has been prepared to operate on a personal computer using a Windows (Microsoft Corporation) operating environment and a point and click type of interface. The user can obtain the spectral acceleration values that would be obtained by use of the maps accompanying the design documents, include site factors appropriate for the Site Class provided by the user, calculate a response spectrum that includes the site factor, and plot a response spectrum. Sites may be located by providing the latitude-longitude or zip code for all areas covered by the maps. All of the maps used in the various documents are also included on the CDROM
Seismic design parameters - A user guide
Leyendecker, E.V.; Frankel, A.D.; Rukstales, K.S.
2001-01-01
The 1997 NEHRP Recommended Provisions for Seismic Regulations for New Buildings (1997 NEHRP Provisions) introduced seismic design procedure that is based on the explicit use of spectral response acceleration rather than the traditional peak ground acceleration and/or peak ground velocity or zone factors. The spectral response accelerations are obtained from spectral response acceleration maps accompanying the report. Maps are available for the United States and a number of U.S. territories. Since 1997 additional codes and standards have also adopted seismic design approaches based on the same procedure used in the NEHRP Provisions and the accompanying maps. The design documents using the 1997 NEHRP Provisions procedure may be divided into three categories -(1) Design of New Construction, (2) Design and Evaluation of Existing Construction, and (3) Design of Residential Construction. A CD-ROM has been prepared for use in conjunction with the design documents in each of these three categories. The spectral accelerations obtained using the software on the CD are the same as those that would be obtained by using the maps accompanying the design documents. The software has been prepared to operate on a personal computer using a Windows (Microsoft Corporation) operating environment and a point and click type of interface. The user can obtain the spectral acceleration values that would be obtained by use of the maps accompanying the design documents, include site factors appropriate for the Site Class provided by the user, calculate a response spectrum that includes the site factor, and plot a response spectrum. Sites may be located by providing the latitude-longitude or zip code for all areas covered by the maps. All of the maps used in the various documents are also included on the CDROM
Calculation of effective parameters of thermoelectromagnetoelastic layered media
NASA Astrophysics Data System (ADS)
Starkov, A. S.; Kudryavtseva, I. V.; Starkov, K. A.; Korzenkov, K. V.
2017-07-01
A system of layered multiferroic materials is averaged with allowance for thermal properties of layers. Matrix averaging is used to obtain effective parameters of the system. Formulas that make it possible to characterize the effect of magnetoelectroelastic coefficients of layers on thermal parameters are derived. The presence of pyrocoefficients in the system is possible even in the absence of the coefficients for the layers. The heat capacity of the system ceases to be an additive quantity and becomes dependent on permittivity and permeability of the layers owing to the interaction of the fields.
Microcomputer Calculation of Thermodynamic Properties from Molecular Parameters of Gases.
ERIC Educational Resources Information Center
Venugopalan, Mundiyath
1990-01-01
Described in this article is a problem-solving activity which integrates the application of microcomputers with the learning of physical chemistry. Students use the program with spectroscopic data to calculate the thermodynamic properties and compare them with the values from the thermochemical tables. (Author/KR)
Design parameters for rotating cylindrical filtration
NASA Technical Reports Server (NTRS)
Schwille, John A.; Mitra, Deepanjan; Lueptow, Richard M.
2002-01-01
Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions. c2002 Elsevier Science B.V. All rights reserved.
Design parameters for rotating cylindrical filtration
NASA Technical Reports Server (NTRS)
Schwille, John A.; Mitra, Deepanjan; Lueptow, Richard M.
2002-01-01
Rotating cylindrical filtration displays significantly reduced plugging of filter pores and build-up of a cake layer, but the number and range of parameters that can be adjusted complicates the design of these devices. Twelve individual parameters were investigated experimentally by measuring the build-up of particles on the rotating cylindrical filter after a fixed time of operation. The build-up of particles on the filter depends on the rotational speed, the radial filtrate flow, the particle size and the gap width. Other parameters, such as suspension concentration and total flow rate are less important. Of the four mechanisms present in rotating filters to reduce pore plugging and cake build-up, axial shear, rotational shear, centrifugal sedimentation and vortical motion, the evidence suggests rotational shear is the dominant mechanism, although the other mechanisms still play minor roles. The ratio of the shear force acting parallel to the filter surface on a particle to the Stokes drag acting normal to the filter surface on the particle due to the difference between particle motion and filtrate flow can be used as a non-dimensional parameter that predicts the degree of particle build-up on the filter surface for a wide variety of filtration conditions. c2002 Elsevier Science B.V. All rights reserved.
Calculation and optimization of parameters in low-flow pumps
NASA Astrophysics Data System (ADS)
Kraeva, E. M.; Masich, I. S.
2016-04-01
The materials on balance tests of high-speed centrifugal pumps with low flow rate are presented. On the bases of analysis and research synthesis, we demonstrate the rational use of impellers of semi-open and open types providing high values for energy parameters of feed system of low-flow pumps.
Recursive least squares approach to calculate motion parameters for a moving camera
NASA Astrophysics Data System (ADS)
Chang, Samuel H.; Fuller, Joseph; Farsaie, Ali; Elkins, Les
2003-10-01
The increase in quality and the decrease in price of digital camera equipment have led to growing interest in reconstructing 3-dimensional objects from sequences of 2-dimensional images. The accuracy of the models obtained depends on two sets of parameter estimates. The first is the set of lens parameters - focal length, principal point, and distortion parameters. The second is the set of motion parameters that allows the comparison of a moving camera"s desired location to a theoretical location. In this paper, we address the latter problem, i.e. the estimation of the set of 3-D motion parameters from data obtained with a moving camera. We propose a method that uses Recursive Least Squares for camera motion parameter estimation with observation noise. We accomplish this by calculation of hidden information through camera projection and minimization of the estimation error. We then show how a filter based on the motion parameters estimates may be designed to correct for the errors in the camera motion. The validity of the approach is illustrated by the presentation of experimental results obtained using the methods described in the paper.
Power extraction calculation improvement when local parameters are included
NASA Astrophysics Data System (ADS)
Flores-Mateos, L. M.; Hartnett, M.
2016-02-01
The improvement of the tidal resource assessment will be studied by comparing two approaches in a two-dimensional, finite difference, hydrodynamic model DIVAST-ADI; in a channel of non-varying cross-sectional area that connects two large basins. The first strategy, considers a constant trust coefficient; the second one, use the local field parameters around the turbine. These parameters are obtained after applying the open channel theory in the tidal stream and after considering the turbine as a linear momentum actuator disk. The parameters correspond to the upstream and downstream, with respect to the turbine, speeds and depths; also the blockage ratio, the wake velocity and the bypass coefficients and they have already been incorporated in the model. The figure (a) shows the numerical configuration at high tide developed with DIVAST-ADI. The experiment undertakes two open boundary conditions. The first one is a sinusoidal forcing introduced as a water level located at (I, J=1) and the second one, indicate that a zero velocity and a constant water depth were kept (I, J=362); when the turbine is introduced it is placed in the middle of the channel (I=161, J=181). The influence of the turbine in the velocity and elevation around the turbine region is evident; figure (b) and (c) shows that the turbine produces a discontinuity in the depth and velocity profile, when we plot a transect along the channel. Finally, the configuration implemented reproduced with satisfactory accuracy the quasi-steady flow condition, even without presenting shock-capturing capability. Also, the range of the parameters 0.01<α 4<0.55, $0
Machine Learning of Parameters for Accurate Semiempirical Quantum Chemical Calculations
2015-01-01
We investigate possible improvements in the accuracy of semiempirical quantum chemistry (SQC) methods through the use of machine learning (ML) models for the parameters. For a given class of compounds, ML techniques require sufficiently large training sets to develop ML models that can be used for adapting SQC parameters to reflect changes in molecular composition and geometry. The ML-SQC approach allows the automatic tuning of SQC parameters for individual molecules, thereby improving the accuracy without deteriorating transferability to molecules with molecular descriptors very different from those in the training set. The performance of this approach is demonstrated for the semiempirical OM2 method using a set of 6095 constitutional isomers C7H10O2, for which accurate ab initio atomization enthalpies are available. The ML-OM2 results show improved average accuracy and a much reduced error range compared with those of standard OM2 results, with mean absolute errors in atomization enthalpies dropping from 6.3 to 1.7 kcal/mol. They are also found to be superior to the results from specific OM2 reparameterizations (rOM2) for the same set of isomers. The ML-SQC approach thus holds promise for fast and reasonably accurate high-throughput screening of materials and molecules. PMID:26146493
Machine learning of parameters for accurate semiempirical quantum chemical calculations
Dral, Pavlo O.; von Lilienfeld, O. Anatole; Thiel, Walter
2015-04-14
We investigate possible improvements in the accuracy of semiempirical quantum chemistry (SQC) methods through the use of machine learning (ML) models for the parameters. For a given class of compounds, ML techniques require sufficiently large training sets to develop ML models that can be used for adapting SQC parameters to reflect changes in molecular composition and geometry. The ML-SQC approach allows the automatic tuning of SQC parameters for individual molecules, thereby improving the accuracy without deteriorating transferability to molecules with molecular descriptors very different from those in the training set. The performance of this approach is demonstrated for the semiempirical OM2 method using a set of 6095 constitutional isomers C_{7}H_{10}O_{2}, for which accurate ab initio atomization enthalpies are available. The ML-OM2 results show improved average accuracy and a much reduced error range compared with those of standard OM2 results, with mean absolute errors in atomization enthalpies dropping from 6.3 to 1.7 kcal/mol. They are also found to be superior to the results from specific OM2 reparameterizations (rOM2) for the same set of isomers. The ML-SQC approach thus holds promise for fast and reasonably accurate high-throughput screening of materials and molecules.
Machine Learning of Parameters for Accurate Semiempirical Quantum Chemical Calculations
Dral, Pavlo O.; von Lilienfeld, O. Anatole; Thiel, Walter
2015-05-01
We investigate possible improvements in the accuracy of semiempirical quantum chemistry (SQC) methods through the use of machine learning (ML) models for the parameters. For a given class of compounds, ML techniques require sufficiently large training sets to develop ML models that can be used for adapting SQC parameters to reflect changes in molecular composition and geometry. The ML-SQC approach allows the automatic tuning of SQC parameters for individual molecules, thereby improving the accuracy without deteriorating transferability to molecules with molecular descriptors very different from those in the training set. The performance of this approach is demonstrated for the semiempirical OM2 method using a set of 6095 constitutional isomers C7H10O2, for which accurate ab initio atomization enthalpies are available. The ML-OM2 results show improved average accuracy and a much reduced error range compared with those of standard OM2 results, with mean absolute errors in atomization enthalpies dropping from 6.3 to 1.7 kcal/mol. They are also found to be superior to the results from specific OM2 reparameterizations (rOM2) for the same set of isomers. The ML-SQC approach thus holds promise for fast and reasonably accurate high-throughput screening of materials and molecules.
Machine Learning of Parameters for Accurate Semiempirical Quantum Chemical Calculations.
Dral, Pavlo O; von Lilienfeld, O Anatole; Thiel, Walter
2015-05-12
We investigate possible improvements in the accuracy of semiempirical quantum chemistry (SQC) methods through the use of machine learning (ML) models for the parameters. For a given class of compounds, ML techniques require sufficiently large training sets to develop ML models that can be used for adapting SQC parameters to reflect changes in molecular composition and geometry. The ML-SQC approach allows the automatic tuning of SQC parameters for individual molecules, thereby improving the accuracy without deteriorating transferability to molecules with molecular descriptors very different from those in the training set. The performance of this approach is demonstrated for the semiempirical OM2 method using a set of 6095 constitutional isomers C7H10O2, for which accurate ab initio atomization enthalpies are available. The ML-OM2 results show improved average accuracy and a much reduced error range compared with those of standard OM2 results, with mean absolute errors in atomization enthalpies dropping from 6.3 to 1.7 kcal/mol. They are also found to be superior to the results from specific OM2 reparameterizations (rOM2) for the same set of isomers. The ML-SQC approach thus holds promise for fast and reasonably accurate high-throughput screening of materials and molecules.
Machine learning of parameters for accurate semiempirical quantum chemical calculations
Dral, Pavlo O.; von Lilienfeld, O. Anatole; Thiel, Walter
2015-04-14
We investigate possible improvements in the accuracy of semiempirical quantum chemistry (SQC) methods through the use of machine learning (ML) models for the parameters. For a given class of compounds, ML techniques require sufficiently large training sets to develop ML models that can be used for adapting SQC parameters to reflect changes in molecular composition and geometry. The ML-SQC approach allows the automatic tuning of SQC parameters for individual molecules, thereby improving the accuracy without deteriorating transferability to molecules with molecular descriptors very different from those in the training set. The performance of this approach is demonstrated for the semiempiricalmore » OM2 method using a set of 6095 constitutional isomers C7H10O2, for which accurate ab initio atomization enthalpies are available. The ML-OM2 results show improved average accuracy and a much reduced error range compared with those of standard OM2 results, with mean absolute errors in atomization enthalpies dropping from 6.3 to 1.7 kcal/mol. They are also found to be superior to the results from specific OM2 reparameterizations (rOM2) for the same set of isomers. The ML-SQC approach thus holds promise for fast and reasonably accurate high-throughput screening of materials and molecules.« less
Design parameters and source terms: Volume 1, Design parameters: Revision 0
Not Available
1987-10-01
The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites.
Design sensitivity analysis using EAL. Part 1: Conventional design parameters
NASA Technical Reports Server (NTRS)
Dopker, B.; Choi, Kyung K.; Lee, J.
1986-01-01
A numerical implementation of design sensitivity analysis of builtup structures is presented, using the versatility and convenience of an existing finite element structural analysis code and its database management system. The finite element code used in the implemenatation presented is the Engineering Analysis Language (EAL), which is based on a hybrid method of analysis. It was shown that design sensitivity computations can be carried out using the database management system of EAL, without writing a separate program and a separate database. Conventional (sizing) design parameters such as cross-sectional area of beams or thickness of plates and plane elastic solid components are considered. Compliance, displacement, and stress functionals are considered as performance criteria. The method presented is being extended to implement shape design sensitivity analysis using a domain method and a design component method.
Computing tools for accelerator design calculations
Fischler, M.; Nash, T.
1984-01-01
This note is intended as a brief, summary guide for accelerator designers to the new generation of commercial and special processors that allow great increases in computing cost effectiveness. New thinking is required to take best advantage of these computing opportunities, in particular, when moving from analytical approaches to tracking simulations. In this paper, we outline the relevant considerations.
Methods of calculating engineering parameters for gas separations
NASA Technical Reports Server (NTRS)
Lawson, D. D.
1980-01-01
A group additivity method has been generated which makes it possible to estimate, from the structural formulas alone, the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. From these two parameters and appropriate thermodynamic relationships it is then possible to predict the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids. The data are then used to evaluate organic and some inorganic liquids for use in gas separation stages or as heat exchange fluids in prospective thermochemical cycles for hydrogen production.
Calculation of RIXS spectra of cuprates using band structure parameters
NASA Astrophysics Data System (ADS)
Shi, Yifei; Klich, Israel; Benjamin, David; Demler, Eugene
2015-03-01
We explore the quasi particle theory to study the Resonant Inelastic X-ray Scattering(RIXS) by using the band structure parameters. We use both the determinant method(D. Benjamin, I. Klich and E. Demler, Phys. Rev. Lett. 112, 247002(2014)) and the expansion in the core-hole potential. The methods are applied to the (CaxLa1?x)(Ba1 . 75 - xLa0 . 25 + x)Cu3Oy, (x= 0 . 1 and 0 . 4). We find that by using the band structure alone we can obtain quantitative agreement with the experimental data, especially for the position of the peak.
Methods of calculating engineering parameters for gas separations
NASA Technical Reports Server (NTRS)
Lawson, D. D.
1980-01-01
A group additivity method has been generated which makes it possible to estimate, from the structural formulas alone, the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. From these two parameters and appropriate thermodynamic relationships it is then possible to predict the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids. The data are then used to evaluate organic and some inorganic liquids for use in gas separation stages or as heat exchange fluids in prospective thermochemical cycles for hydrogen production.
NASA Astrophysics Data System (ADS)
Finchenko, V. S.; Ivankov, A. A.; Shmatov, S. I.; Mordvinkin, A. S.
2015-12-01
The article presents the initial data for the ExoMars landing module aerothermodynamic calculations, used calculation methods, the calculation results of aerodynamic characteristics of the landing module shape and structural parameters of thermal protection selected during the conceptual design phase. Also, the test results of the destruction of the thermal protection material and comparison of the basic characteristics of the landing module with a front shield in the form of a cone and a spherical segment are presented.
Calculating room acoustic parameters from pseudo-impulsive acoustic sources
NASA Astrophysics Data System (ADS)
San Martin, Maria L.; Vela, Antonio; San Martin, Ricardo; Arana, Miguel A.
2002-11-01
The impulse response function provides complete information to predict the acoustic response of a room to an acoustic input of arbitrary characteristics. At this job study, small explosions of firecrackers are proposed to be used as pseudo-impulsive acoustics sources to determine some acoustic parameters of a room such as reverberation time, definition, and clarity, comparing these results to those obtained with other techniques. A previous characterization of these sources allows us to state that they can be used for this purpose because they are, in practice, omnidirectional, their temporary pattern is highly repetitive and their spectral power is, as well, repetitive and with enough power in octave bands from 125 Hz to 8 kHz. If the linear time-invariant system impulse response h(t) is known, output signal s(t) regarding any arbitrary signal s(t) can be obtained. For our pseudo-impulsive sources, the output signal s(t) has been taken as impulse response h(t). Using the integrated impulse response method suggested by Schroeder, it has been stated that both the mean values and standard deviations for some parameters are practically identical to results obtained with other usual techniques. (To be presented in Spanish.)
Design Calculations For NIF Convergent Ablator Experiments
Olson, R E; Hicks, D G; Meezan, N B; Callahan, D A; Landen, O L; Jones, O S; Langer, S H; Kline, J L; Wilson, D C; Rinderknecht, H; Zylstra, A; Petrasso, R D
2011-10-25
The NIF convergent ablation tuning effort is underway. In the early experiments, we have discovered that the design code simulations over-predict the capsule implosion velocity and shock flash rhor, but under-predict the hohlraum x-ray flux measurements. The apparent inconsistency between the x-ray flux and radiography data implies that there are important unexplained aspects of the hohlraum and/or capsule behavior.
Diffraction performance calculations in lens design.
NASA Astrophysics Data System (ADS)
Malacara, D.
A review of the methods employed to compute the wavefront shape, the point spread function and the optical transfer function in lens evaluation programs is presented. One of the simplest methods to perform numerical calculations of the diffraction performance of optical systems is to divide the aperture in small squares, and then to consider the wavefront in each of these small squares to be flat and perpendicular to the ray direction in that region. This method however, presents some limitations, since the wavefront has to be flat within a fraction of the wavelength in that small square. This might not be the case if the wavefront is either too aberrated, or the defocusing is too large.
Analytic calculation of physiological acid-base parameters in plasma.
Wooten, E W
1999-01-01
Analytic expressions for plasma total titratable base, base excess (DeltaCB), strong-ion difference, change in strong-ion difference (DeltaSID), change in Van Slyke standard bicarbonate (DeltaVSSB), anion gap, and change in anion gap are derived as a function of pH, total buffer ion concentration, and conditional molar equilibrium constants. The behavior of these various parameters under respiratory and metabolic acid-base disturbances for constant and variable buffer ion concentrations is considered. For constant noncarbonate buffer concentrations, DeltaSID = DeltaCB = DeltaVSSB, whereas these equalities no longer hold under changes in noncarbonate buffer concentration. The equivalence is restored if the reference state is changed to include the new buffer concentrations.
Recommended environmental dose calculation methods and Hanford-specific parameters
Schreckhise, R.G.; Rhoads, K.; Napier, B.A.; Ramsdell, J.V. ); Davis, J.S. )
1993-03-01
This document was developed to support the Hanford Environmental Dose overview Panel (HEDOP). The Panel is responsible for reviewing all assessments of potential doses received by humans and other biota resulting from the actual or possible environmental releases of radioactive and other hazardous materials from facilities and/or operations belonging to the US Department of Energy on the Hanford Site in south-central Washington. This document serves as a guide to be used for developing estimates of potential radiation doses, or other measures of risk or health impacts, to people and other biota in the environs on and around the Hanford Site. It provides information to develop technically sound estimates of exposure (i.e., potential or actual) to humans or other biotic receptors that could result from the environmental transport of potentially harmful materials that have been, or could be, released from Hanford operations or facilities. Parameter values and information that are specific to the Hanford environs as well as other supporting material are included in this document.
Design of initial dosage regimen using a programmable calculator.
Ritschel, W A; Eldon, M A
1985-07-01
A programmable calculator procedure for the determination of dosage regimens to achieve desired steady state concentrations is described. The dosage regimen prediction is based on data from the literature on pharmacokinetic parameters of drugs and correction factors specific for the patient's condition, such as renal failure, geriatric patient and congestive heart failure. The program is designed to generate dosage regimens based on desired steady state trough level, desired steady state peak level, desired mean steady state level, or to fluctuate between desired steady state peak and trough levels. The program can be used for I.V. and extravascular route of administration. A detailed program description and user instructions are presented and illustrated by three examples.
Cryogenic masers. [frequency stability and design parameters
NASA Technical Reports Server (NTRS)
Berlinsky, A. J.; Hardy, W. N.
1982-01-01
Various factors affecting the frequency stability of hydrogen masers are described and related to maser design parameters. The long-term frequency stability of a hydrogen maser is limited by the mechanical stability of the cavity, and the magnitudes of the wall relaxation, spin exchange, and recombination rates which affect the Q of the line. Magnetic resonance studies of hydrogen atoms at temperatures below 1 K and in containers coated with liquid helium films demonstrated that cryogenic masers may allow substantial improvements in all of these parameters. In particular the thermal expansion coefficients of most materials are negligible at 1 K. Spin exchange broadening is three orders of magnitude smaller at 1 K than at room temperature, and the recombination and wall relaxation rates are negligible at 0.52 K where the frequency shift due to the 4 He-coated walls of the container has a broad minimum as a function of temperature. Other advantages of the helium-cooled maser result from the high purity, homogeneity, and resilence of helium-film-coated walls and the natural compatibility of the apparatus with helium-cooled amplifiers.
Calculating Balanced Incomplete Block Design for Educational Assessments.
ERIC Educational Resources Information Center
van der Linden, Wim J.; Carlson, James E.
A popular design in large-scale educational assessments is the balanced incomplete block design. The design assumes that the item pool is split into a set of blocks of items that are assigned to assessment booklets. This paper shows how the technique of 0-1 linear programming can be used to calculate a balanced incomplete block design. Several…
The shear instability energy: a new parameter for materials design?
NASA Astrophysics Data System (ADS)
Kanani, M.; Hartmaier, A.; Janisch, R.
2017-10-01
Reliable and predictive relationships between fundamental microstructural material properties and observable macroscopic mechanical behaviour are needed for the successful design of new materials. In this study we establish a link between physical properties that are defined on the atomic level and the deformation mechanisms of slip planes and interfaces that govern the mechanical behaviour of a metallic material. To accomplish this, the shear instability energy Γ is introduced, which can be determined via quantum mechanical ab initio calculations or other atomistic methods. The concept is based on a multilayer generalised stacking fault energy calculation and can be applied to distinguish the different shear deformation mechanisms occurring at TiAl interfaces during finite-temperature molecular dynamics simulations. We use the new parameter Γ to construct a deformation mechanism map for different interfaces occurring in this intermetallic. Furthermore, Γ can be used to convert the results of ab initio density functional theory calculations into those obtained with an embedded atom method type potential for TiAl. We propose to include this new physical parameter into material databases to apply it for the design of materials and microstructures, which so far mainly relies on single-crystal values for the unstable and stable stacking fault energy.
Calculating background levels for ecological risk parameters in toxic harbor sediment
Leadon, C.J.; McDonnell, T.R.; Lear, J.; Barclift, D.
2007-01-01
Establishing background levels for biological parameters is necessary in assessing the ecological risks from harbor sediment contaminated with toxic chemicals. For chemicals in sediment, the term contaminated is defined as having concentrations above background and significant human health or ecological risk levels. For biological parameters, a site could be considered contaminated if levels of the parameter are either more or less than the background level, depending on the specific parameter. Biological parameters can include tissue chemical concentrations in ecological receptors, bioassay responses, bioaccumulation levels, and benthic community metrics. Chemical parameters can include sediment concentrations of a variety of potentially toxic chemicals. Indirectly, contaminated harbor sediment can impact shellfish, fish, birds, and marine mammals, and human populations. This paper summarizes the methods used to define background levels for chemical and biological parameters from a survey of ecological risk investigations of marine harbor sediment at California Navy bases. Background levels for regional biological indices used to quantify ecological risks for benthic communities are also described. Generally, background stations are positioned in relatively clean areas exhibiting the same physical and general chemical characteristics as nearby areas with contaminated harbor sediment. The number of background stations and the number of sample replicates per background station depend on the statistical design of the sediment ecological risk investigation, developed through the data quality objective (DQO) process. Biological data from the background stations can be compared to data from a contaminated site by using minimum or maximum background levels or comparative statistics. In Navy ecological risk assessments (ERA's), calculated background levels and appropriate ecological risk screening criteria are used to identify sampling stations and sites with contaminated
Optimal Linking Design for Response Model Parameters
ERIC Educational Resources Information Center
Barrett, Michelle D.; van der Linden, Wim J.
2017-01-01
Linking functions adjust for differences between identifiability restrictions used in different instances of the estimation of item response model parameters. These adjustments are necessary when results from those instances are to be compared. As linking functions are derived from estimated item response model parameters, parameter estimation…
NASA Technical Reports Server (NTRS)
Hughes, D. L.; Ray, R. J.; Walton, J. T.
1985-01-01
The calculated value of net thrust of an aircraft powered by a General Electric F404-GE-400 afterburning turbofan engine was evaluated for its sensitivity to various input parameters. The effects of a 1.0-percent change in each input parameter on the calculated value of net thrust with two calculation methods are compared. This paper presents the results of these comparisons and also gives the estimated accuracy of the overall net thrust calculation as determined from the influence coefficients and estimated parameter measurement accuracies.
M. Gross
2004-09-01
The purpose of this scientific analysis is to define the sampled values of stochastic (random) input parameters for (1) rockfall calculations in the lithophysal and nonlithophysal zones under vibratory ground motions, and (2) structural response calculations for the drip shield and waste package under vibratory ground motions. This analysis supplies: (1) Sampled values of ground motion time history and synthetic fracture pattern for analysis of rockfall in emplacement drifts in nonlithophysal rock (Section 6.3 of ''Drift Degradation Analysis'', BSC 2004 [DIRS 166107]); (2) Sampled values of ground motion time history and rock mechanical properties category for analysis of rockfall in emplacement drifts in lithophysal rock (Section 6.4 of ''Drift Degradation Analysis'', BSC 2004 [DIRS 166107]); (3) Sampled values of ground motion time history and metal to metal and metal to rock friction coefficient for analysis of waste package and drip shield damage to vibratory motion in ''Structural Calculations of Waste Package Exposed to Vibratory Ground Motion'' (BSC 2004 [DIRS 167083]) and in ''Structural Calculations of Drip Shield Exposed to Vibratory Ground Motion'' (BSC 2003 [DIRS 163425]). The sampled values are indices representing the number of ground motion time histories, number of fracture patterns and rock mass properties categories. These indices are translated into actual values within the respective analysis and model reports or calculations. This report identifies the uncertain parameters and documents the sampled values for these parameters. The sampled values are determined by GoldSim V6.04.007 [DIRS 151202] calculations using appropriate distribution types and parameter ranges. No software development or model development was required for these calculations. The calculation of the sampled values allows parameter uncertainty to be incorporated into the rockfall and structural response calculations that support development of the seismic scenario for the
Monte Carlo calculation of dosimetry parameters for the IR08-103Pd brachytherapy source.
Saidi, Pooneh; Sadeghi, Mahdi; Shirazi, Alireza; Tenreiro, Claudio
2010-06-01
For the treatment of some cancerous tumors using brachytherapy methods and low-energy photon sources, such as 125I and 103Pd, the American Association of Physicists in Medicine Task Group No. 43U1 report recommends that the dosimetric parameters of a new brachytherapy source must be determined in two experimental and Monte Carlo theoretical methods before using each new source clinically. This study presents the results of Monte Carlo calculations of the dosimetric parameters for IR08-103Pd brachytherapy source design. IR08-103Pd seed has been manufactured at the Agricultural, Medical and Industrial Research School. Version 5 of the (MCNP) Monte Carlo radiation transport code was used to calculate the dosimetry parameters around the source. Three geometric models of the seed, based on different locations of beads inside the titanium capsule, were simulated. The seed contains five resin beads of 0.6 mm diameter having 103Pd uniformly absorbed in the bead volume, which were contained within a cylindrical titanium capsule having 0.8 mm outside diameter and 4.8 mm length. The Monte Carlo calculated dose rate constant of the IR08-103Pd seed was found to be 0.695 +/- 0.021 cGyU(-1) h(-1). Also in this study, the geometry function G(r, theta), line and point-source radial dose functions gL(r) and gP(r), and the anisotropy function F(r, theta), have been calculated at distances from 0.25 to 7 cm. The results of these calculations have been compared with measured values for an actual IR08-103Pd seed. There are no statistical significant dosimetric differences among the three seed orientations in this study (i.e., ideal, vertical, and diagonal). However, the observed differences between the calculated and measured values could be explained by the measurement uncertainty and the configuration of the resin beads within the capsule and capsule orientation.
Oh, Suk Yung; Bae, Young Chan
2010-07-15
The method presented in this paper was developed to predict liquid-liquid equilibria in ternary liquid mixtures by using a combination of a thermodynamic model and molecular dynamics simulations. In general, common classical thermodynamic models have many parameters which are determined by fitting a model with experimental data. This proposed method, however, provides a simple procedure for calculating liquid-liquid equilibria utilizing binary interaction parameters and molecular size parameters determined from molecular dynamics simulations. This method was applied to mixtures containing water, hydrocarbons, alcohols, chlorides, ketones, acids, and other organic liquids over various temperature ranges. The predicted results agree well with the experimental data without the use of adjustable parameters.
SAMDIST: A Computer Code for Calculating Statistical Distributions for R-Matrix Resonance Parameters
Leal, L.C.
1995-01-01
The: SAMDIST computer code has been developed to calculate distribution of resonance parameters of the Reich-Moore R-matrix type. The program assumes the parameters are in the format compatible with that of the multilevel R-matrix code SAMMY. SAMDIST calculates the energy-level spacing distribution, the resonance width distribution, and the long-range correlation of the energy levels. Results of these calculations are presented in both graphic and tabular forms.
Design parameters and source terms: Volume 1, Design parameters: Revision 0
Not Available
1987-09-01
The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report to the level of the Site Characterization Plan - Conceptual Design Report, SCP-CDR. The previous unpublished SCC Study identified the data needs for the Environmental Assessment effort for seven possible salt repository sites.
Optimizing the Yb:YAG thin disc laser design parameters
NASA Astrophysics Data System (ADS)
Javadi-Dashcasan, M.; Hajiesmaeilbaigi, F.; Razzaghi, H.; Mahdizadeh, M.; Moghadam, M.
2008-09-01
Based on quasi-three-level system, a numerical model of continuous wave thin disc laser is proposed. The fluorescence concentration quenching (FCQ), refractive index depending concentration effects and temperature distribution in the gain medium have been taken into account in the model. The first and second phenomena are not included in previously models. The model is used to determine optimum design parameters and to calculate the influence of various parameters like temperature, number of pump beam passes, active ions concentration and the crystal thickness on the operational efficiency of the laser. This model shows that for higher doping concentrations (>15%) the optical efficiency is decreased due to fluorescence concentration quenching. Our results are excellently in agreement with experimental results.
Aberration analysis calculations for synchrotron radiation beamline design
McKinney, W.R.; Howells, M.; Padmore, H.A.
1997-09-01
The application of ray deviation calculations based on aberration coefficients for a single optical surface for the design of beamline optical systems is reviewed. A systematic development is presented which allows insight into which aberration may be causing the rays to deviate from perfect focus. A new development allowing analytical calculation of line shape is presented.
Validation of HFCS-I on Calculation of High-Frequency Parameters of Helical Slow-Wave Structures
NASA Astrophysics Data System (ADS)
Zhu, Xiaofang; Yang, Zhonghai; Li, Bin; Li, Jianqing; Xu, Li
2010-02-01
To validate HFCS-I, a newly developed design tool for high frequency circuits of microwave tubes, the high-frequency parameters (including dispersion, interaction impedance and attenuation constant) of a typical helical slow-wave structure (SWS) for millimetre wave travelling-wave tube are calculated by HFCS-I and MAFIA. Both the direct calculation method and the Non-Resonant Perturbation (NRP) technique are adopted to get the interaction impedance. The obtained high-frequency parameters from HFCS-I and MAFIA are compared in detail and the consistency has proved the reliability and validity of HFCS-I.
Calculating the mounting parameters for Taylor Spatial Frame correction using computed tomography.
Kucukkaya, Metin; Karakoyun, Ozgur; Armagan, Raffi; Kuzgun, Unal
2011-07-01
The Taylor Spatial Frame uses a computer program-based six-axis deformity analysis. However, there is often a residual deformity after the initial correction, especially in deformities with a rotational component. This problem can be resolved by recalculating the parameters and inputting all new deformity and mounting parameters. However, this may necessitate repeated x-rays and delay treatment. We believe that error in the mounting parameters is the main reason for most residual deformities. To prevent these problems, we describe a new calculation technique for determining the mounting parameters that uses computed tomography. This technique is especially advantageous for deformities with a rotational component. Using this technique, exact calculation of the mounting parameters is possible and the residual deformity and number of repeated x-rays can be minimized. This new technique is an alternative method to accurately calculating the mounting parameters.
Determination of the optimal mesh parameters for Iguassu centrifuge flow and separation calculations
NASA Astrophysics Data System (ADS)
Romanihin, S. M.; Tronin, I. V.
2016-09-01
We present the method and the results of the determination for optimal computational mesh parameters for axisymmetric modeling of flow and separation in the Iguasu gas centrifuge. The aim of this work was to determine the mesh parameters which provide relatively low computational cost whithout loss of accuracy. We use direct search optimization algorithm to calculate optimal mesh parameters. Obtained parameters were tested by the calculation of the optimal working regime of the Iguasu GC. Separative power calculated using the optimal mesh parameters differs less than 0.5% from the result obtained on the detailed mesh. Presented method can be used to determine optimal mesh parameters of the Iguasu GC with different rotor speeds.
Sensitivity of NTCP parameter values against a change of dose calculation algorithm
Brink, Carsten; Berg, Martin; Nielsen, Morten
2007-09-15
Optimization of radiation treatment planning requires estimations of the normal tissue complication probability (NTCP). A number of models exist that estimate NTCP from a calculated dose distribution. Since different dose calculation algorithms use different approximations the dose distributions predicted for a given treatment will in general depend on the algorithm. The purpose of this work is to test whether the optimal NTCP parameter values change significantly when the dose calculation algorithm is changed. The treatment plans for 17 breast cancer patients have retrospectively been recalculated with a collapsed cone algorithm (CC) to compare the NTCP estimates for radiation pneumonitis with those obtained from the clinically used pencil beam algorithm (PB). For the PB calculations the NTCP parameters were taken from previously published values for three different models. For the CC calculations the parameters were fitted to give the same NTCP as for the PB calculations. This paper demonstrates that significant shifts of the NTCP parameter values are observed for three models, comparable in magnitude to the uncertainties of the published parameter values. Thus, it is important to quote the applied dose calculation algorithm when reporting estimates of NTCP parameters in order to ensure correct use of the models.
Extraction of crystal-field parameters for lanthanide ions from quantum-chemical calculations.
Hu, Liusen; Reid, Michael F; Duan, Chang-Kui; Xia, Shangda; Yin, Min
2011-02-02
A simple method for constructing effective Hamiltonians for the 4f(N) and 4f(N - 1)5d energy levels of lanthanide ions in crystals from quantum-chemical calculations is presented. The method is demonstrated by deriving crystal-field and spin-orbit parameters for Ce(3 + ) ions doped in LiYF(4), Cs(2)NaYCl(6), CaF(2), KY(3)F(10) and YAG host crystals from quantum-chemical calculations based on the DV-Xα method. Good agreement between calculated and fitted values of the crystal-field parameters is obtained. The method can be used to calculate parameters even for low-symmetry sites where there are more parameters than energy levels.
Extraction of crystal-field parameters for lanthanide ions from quantum-chemical calculations
NASA Astrophysics Data System (ADS)
Hu, Liusen; Reid, Michael F.; Duan, Chang-Kui; Xia, Shangda; Yin, Min
2011-02-01
A simple method for constructing effective Hamiltonians for the 4fN and 4fN - 15d energy levels of lanthanide ions in crystals from quantum-chemical calculations is presented. The method is demonstrated by deriving crystal-field and spin-orbit parameters for Ce3 + ions doped in LiYF4, Cs2NaYCl6, CaF2, KY3F10 and YAG host crystals from quantum-chemical calculations based on the DV-Xα method. Good agreement between calculated and fitted values of the crystal-field parameters is obtained. The method can be used to calculate parameters even for low-symmetry sites where there are more parameters than energy levels.
NASA Technical Reports Server (NTRS)
Prokhorenko, V. I.
1981-01-01
Subprograms for transforming coordinates and time, for determining the position of the Moon and Sun, and for calculating the atmosphere and disturbances, which are specified by anomalies of the Earth's gravitational field are described. The subprograms are written in FORTRAN IV and form a major part of the package of applied programs for calculating the navigational parameters of artificial Earth satellites.
Tuning of fault tolerant control design parameters.
DeLima, Pedro G; Yen, Gary G
2008-01-01
This paper presents two major contributions in the field of fault tolerant control. First, it gathers points of concern typical to most fault tolerant control applications and translates the chosen performance metrics into a set of six practical design specifications. Second, it proposes initialization and tuning procedures through which a particular fault tolerant control architecture not only can be set to comply with the required specifications, but also can be tuned online to compensate for a total of twelve properties, such as the noise rejection levels for fault detection and diagnosis signals. The proposed design is realized over a powerful architecture that combines the flexibility of adaptive critic designs with the long term memory and learning capabilities of a supervisor. This paper presents a practical design procedure to facilitate the applications of a fundamentally sound fault tolerant control architecture in real-world problems.
NASA Astrophysics Data System (ADS)
Kripal, Ram; Yadav, Awadhesh Kumar
2015-06-01
Zero field splitting parameters (ZFSPs) D and E of Cr3+ ion doped ammonium oxalate monohydrate (AOM) are calculated with formula using the superposition model. The theoretically calculated ZFSPs for Cr3+ in AOM crystal are compared with the experimental value obtained by electron paramagnetic resonance (EPR). Theoretical ZFSPs are in good agreement with the experimental ones. The energy band positions of optical absorption spectra of Cr3+ in AOM crystal calculated with CFA package are in good match with the experimental values.
NASA Technical Reports Server (NTRS)
Barth, Timothy J.
2016-01-01
This chapter discusses the ongoing development of combined uncertainty and error bound estimates for computational fluid dynamics (CFD) calculations subject to imposed random parameters and random fields. An objective of this work is the construction of computable error bound formulas for output uncertainty statistics that guide CFD practitioners in systematically determining how accurately CFD realizations should be approximated and how accurately uncertainty statistics should be approximated for output quantities of interest. Formal error bounds formulas for moment statistics that properly account for the presence of numerical errors in CFD calculations and numerical quadrature errors in the calculation of moment statistics have been previously presented in [8]. In this past work, hierarchical node-nested dense and sparse tensor product quadratures are used to calculate moment statistics integrals. In the present work, a framework has been developed that exploits the hierarchical structure of these quadratures in order to simplify the calculation of an estimate of the quadrature error needed in error bound formulas. When signed estimates of realization error are available, this signed error may also be used to estimate output quantity of interest probability densities as a means to assess the impact of realization error on these density estimates. Numerical results are presented for CFD problems with uncertainty to demonstrate the capabilities of this framework.
Calculation of crystal-field parameters for rare-earth noble metal alloys
NASA Astrophysics Data System (ADS)
Steinbeck, L.; Richter, M.; Eschrig, H.; Nitzsche, U.
1995-02-01
The crystal-field (CF) parameters for 4f electrons of a series of rare earth impurities in Ag and Au have been evaluated from first-principles density functional calculations of the charge distribution which are based on an optimized LCAO scheme. The localized 4f states are treated as 'open core shell'. By including the self-interaction correction for the 4f states, artificial constraints on the 4f charge density employed in earlier density functional CF calculations are avoided. The calculated parameters are compared with recent neutron scattering data.
Rapid calculation of terrain parameters for radiation modeling from digital elevation data
NASA Technical Reports Server (NTRS)
Dozier, Jeff; Frew, James
1990-01-01
Digital elevation models are now widely used to calculate terrain parameters to determine incoming solar and longwave radiation for use in surface climate models, interpretation of remote-sensing data, and parameters in hydrologic models. Because of the large number of points in an elevation grid, fast algorithms are useful to save computation time. A description is given of rapid methods for calculating slope and azimuth, solar illumination angle, horizons, and view factors for radiation from sky and terrain. Calculation time is reduced by fast algorithms and lookup tables.
Experimental Design and Power Calculation for RNA-seq Experiments.
Wu, Zhijin; Wu, Hao
2016-01-01
Power calculation is a critical component of RNA-seq experimental design. The flexibility of RNA-seq experiment and the wide dynamic range of transcription it measures make it an attractive technology for whole transcriptome analysis. These features, in addition to the high dimensionality of RNA-seq data, bring complexity in experimental design, making an analytical power calculation no longer realistic. In this chapter we review the major factors that influence the statistical power of detecting differential expression, and give examples of power assessment using the R package PROPER.
Valencia, Pedro L; Astudillo-Castro, Carolina; Gajardo, Diego; Flores, Sebastián
2017-04-01
We provide initial rate data from enzymatic reaction experiments and tis processing to estimate the kinetic parameters from the substrate uncompetitive inhibition equation using the median method published by Eisenthal and Cornish-Bowden (Cornish-Bowden and Eisenthal, 1974; Eisenthal and Cornish-Bowden, 1974). The method was denominated the direct linear plot and consists in the calculation of the median from a dataset of kinetic parameters Vmax and Km from the Michaelis-Menten equation. In this opportunity we present the procedure to applicate the direct linear plot to the substrate uncompetitive inhibition equation; a three-parameter equation. The median method is characterized for its robustness and its insensibility to outlier. The calculations are presented in an Excel datasheet and a computational algorithm was developed in the free software Python. The kinetic parameters of the substrate uncompetitive inhibition equation Vmax , Km and Ks were calculated using three experimental points from the dataset formed by 13 experimental points. All the 286 combinations were calculated. The dataset of kinetic parameters resulting from this combinatorial was used to calculate the median which corresponds to the statistic estimator of the real kinetic parameters. A comparative statistical analyses between the median method and the least squares was published in Valencia et al. [3].
NASA Astrophysics Data System (ADS)
Campolina, Daniel de A. M.; Lima, Claubia P. B.; Veloso, Maria Auxiliadora F.
2014-06-01
For all the physical components that comprise a nuclear system there is an uncertainty. Assessing the impact of uncertainties in the simulation of fissionable material systems is essential for a best estimate calculation that has been replacing the conservative model calculations as the computational power increases. The propagation of uncertainty in a simulation using a Monte Carlo code by sampling the input parameters is recent because of the huge computational effort required. In this work a sample space of MCNPX calculations was used to propagate the uncertainty. The sample size was optimized using the Wilks formula for a 95th percentile and a two-sided statistical tolerance interval of 95%. Uncertainties in input parameters of the reactor considered included geometry dimensions and densities. It was showed the capacity of the sampling-based method for burnup when the calculations sample size is optimized and many parameter uncertainties are investigated together, in the same input.
Rafiee, Marjan A; Hadipour, Nasser L; Naderi-manesh, Hossein
2004-03-01
In this paper, ab initio calculated NQR parameters for some quinoline-containing derivatives are presented. The calculations are carried out in a search for the relationships between the charge distribution of these compounds and their ability to interact with haematin. On the basis of NQR parameters, pi-electron density on the nitrogen atom of the quinoline ring plays a dominant role in determining the ability of quinolines to interact with haematin. This point was confirmed with investigation of Fe+3 cation-pi quinoline ring interactions in 2- and 4-aminoquinoline. However, our results do not show any preference for those carbon atoms of the quinoline ring which previous reports have noted. In order to calculate the NQR parameters, the electric field gradient (EFG) should be evaluated at the site of a quadrupolar nucleus in each compound. EFGs are calculated by the Gaussian 98 program using the B3LYP/6-31 G* level of theory.
Mumford, Jeanette A; Nichols, Thomas E
2008-01-01
When planning most scientific studies, one of the first steps is to carry out a power analysis to define a design and sample size that will result in a well-powered study. There are limited resources for calculating power for group fMRI studies due to the complexity of the model. Previous approaches for group fMRI power calculation simplify the study design and/or the variance structure in order to make the calculation possible. These approaches limit the designs that can be studied and may result in inaccurate power calculations. We introduce a flexible power calculation model that makes fewer simplifying assumptions, leading to a more accurate power analysis that can be used on a wide variety of study designs. Our power calculation model can be used to obtain region of interest (ROI) summaries of the mean parameters and variance parameters, which can be use to increase understanding of the data as well as calculate power for a future study. Our example illustrates that minimizing cost to achieve 80% power is not as simple as finding the smallest sample size capable of achieving 80% power, since smaller sample sizes require each subject to be scanned longer.
100 km CEPC parameters and lattice design
NASA Astrophysics Data System (ADS)
Wang, D.; Gao, J.; Yu, C. H.; Zhang, Y.; Wang, Y. W.; Su, F.; Y Zhai, J.; Bai, S.; Geng, H. P.; Bian, T. J.; Wang, N.; Cui, X. H.; Zhang, C.; Qin, Q.
2017-07-01
The 100km double ring configuration with shared superconducting RF system has been defined as baseline by the circular electron positron collider (CEPC) steering committee. Based on this new scheme, we will get higher luminosity for Higgs (+170%) keeping the beam power in preliminary conceptual design report (Pre-CDR) or to reduce the beam power (19 MW) while keeping same luminosity. CEPC will be compatible with W and Z experiment. The luminosity for Z is designed at the level of 1035 cm-2s-1. The requirement for the energy acceptance of Higgs has been reduced to 1.5% by enlarging the ring to 100 km. The optics of arc and final focus system (FFS) with crab sextupoles has been designed, and also some primary dynamic aperture (DA) results were introduced. Work supported by the National Key Programme for S&T Research and Development (Grant NO. 2016YFA0400400) and the National Natural Science Foundation of China (11505198, 11575218, 11605210 and 11605211).
NASA Astrophysics Data System (ADS)
Xiao, Shou-Ne; Wang, Ming-Meng; Hu, Guang-Zhong; Yang, Guang-Wu
2017-09-01
In view of the problem that it's difficult to accurately grasp the influence range and transmission path of the vehicle top design requirements on the underlying design parameters. Applying directed-weighted complex network to product parameter model is an important method that can clarify the relationships between product parameters and establish the top-down design of a product. The relationships of the product parameters of each node are calculated via a simple path searching algorithm, and the main design parameters are extracted by analysis and comparison. A uniform definition of the index formula for out-in degree can be provided based on the analysis of out-in-degree width and depth and control strength of train carriage body parameters. Vehicle gauge, axle load, crosswind and other parameters with higher values of the out-degree index are the most important boundary conditions; the most considerable performance indices are the parameters that have higher values of the out-in-degree index including torsional stiffness, maximum testing speed, service life of the vehicle, and so on; the main design parameters contain train carriage body weight, train weight per extended metre, train height and other parameters with higher values of the in-degree index. The network not only provides theoretical guidance for exploring the relationship of design parameters, but also further enriches the application of forward design method to high-speed trains.
Robust design of configurations and parameters of adaptable products
NASA Astrophysics Data System (ADS)
Zhang, Jian; Chen, Yongliang; Xue, Deyi; Gu, Peihua
2014-03-01
An adaptable product can satisfy different customer requirements by changing its configuration and parameter values during the operation stage. Design of adaptable products aims at reducing the environment impact through replacement of multiple different products with single adaptable ones. Due to the complex architecture, multiple functional requirements, and changes of product configurations and parameter values in operation, impact of uncertainties to the functional performance measures needs to be considered in design of adaptable products. In this paper, a robust design approach is introduced to identify the optimal design configuration and parameters of an adaptable product whose functional performance measures are the least sensitive to uncertainties. An adaptable product in this paper is modeled by both configurations and parameters. At the configuration level, methods to model different product configuration candidates in design and different product configuration states in operation to satisfy design requirements are introduced. At the parameter level, four types of product/operating parameters and relations among these parameters are discussed. A two-level optimization approach is developed to identify the optimal design configuration and its parameter values of the adaptable product. A case study is implemented to illustrate the effectiveness of the newly developed robust adaptable design method.
Large break LOCA calculations for the AP600 design
Fisher, J.E.
1992-08-01
This paper presents the application of RELAP5 to the calculation of a Large Break (200% doubled-ended rupture) Loss-of-Colant-Accident (LBLOCA) at the reactor vessel inlet for the proposed Westinghouse AP600 design. A parametric calculation was also performed to determine effects of loss of a complete Emergency Core Cooling system (ECCS) train. These calculations were performed over the core blowdown, refill, and reflood phases of the LBLOCA and did not address long term cooling. RELAP5 was shown to be adequate for system response calculation over the period of interest. The passive safety systems were predicted to effectively mitigate the consequences of LBLOCAs; the calculations showed less severe thermal responses than for a current generation Pressurized Water Reactor (PWR) plant. The two primary differences between the AP600 design and a current generation plant that affect LBLOCA response are the lower core thermal power, which results in lower temperatures during the blowdown phase, and the long duration accumulator injection, which provides ample core inventory makeup for final quenching.
Large break LOCA calculations for the AP600 design
Fisher, J.E.
1992-01-01
This paper presents the application of RELAP5 to the calculation of a Large Break (200% doubled-ended rupture) Loss-of-Colant-Accident (LBLOCA) at the reactor vessel inlet for the proposed Westinghouse AP600 design. A parametric calculation was also performed to determine effects of loss of a complete Emergency Core Cooling system (ECCS) train. These calculations were performed over the core blowdown, refill, and reflood phases of the LBLOCA and did not address long term cooling. RELAP5 was shown to be adequate for system response calculation over the period of interest. The passive safety systems were predicted to effectively mitigate the consequences of LBLOCAs; the calculations showed less severe thermal responses than for a current generation Pressurized Water Reactor (PWR) plant. The two primary differences between the AP600 design and a current generation plant that affect LBLOCA response are the lower core thermal power, which results in lower temperatures during the blowdown phase, and the long duration accumulator injection, which provides ample core inventory makeup for final quenching.
Calculated crystal-field parameters for rare-earth impurities in noble metals
NASA Astrophysics Data System (ADS)
Steinbeck, Lutz; Richter, Manuel; Eschrig, Helmut; Nitzsche, Ulrike
1994-06-01
From first-principles density-functional calculations of the charge distribution the crystal-field (CF) parameters for 4f states of Er and Dy impurities in Ag and Au have been evaluated. The calculations are based on an optimized linear combination of atomic orbitals scheme, where the local-density approximation (LDA) is used for the conduction-electron states, while the localized rare-earth 4f states are treated as ``open core shell.'' As the 4f localization cannot be properly described within LDA, a self-interaction correction for the 4f states is included. In this way, any artificial constraints on the 4f charge density employed in earlier first-principles CF calculations are avoided. The calculated CF parameters agree well with recent neutron scattering data.
The effect of different calculation methods of flywheel parameters on the Wingate Anaerobic Test.
Coleman, S G; Hale, T
1998-08-01
Researchers compared different methods of calculating kinetic parameters of friction-braked cycle ergometers, and the subsequent effects on calculating power outputs in the Wingate Anaerobic Test (WAnT). Three methods of determining flywheel moment of inertia and frictional torque were investigated, requiring "run-down" tests and segmental geometry. Parameters were used to calculate corrected power outputs from 10 males in a 30-s WAnT against a load related to body mass (0.075 kg.kg-1). Wingate Indices of maximum (5 s) power, work, and fatigue index were also compared. Significant differences were found between uncorrected and corrected power outputs and between correction methods (p < .05). The same finding was evident for all Wingate Indices (p < .05). Results suggest that WAnT must be corrected to give true power outputs and that choosing an appropriate correction calculation is important. Determining flywheel moment of inertia and frictional torque using unloaded run-down tests is recommended.
Multiobjective insensitive design of airplane control systems with uncertain parameters
NASA Technical Reports Server (NTRS)
Schy, A. A.; Giesy, D. P.
1981-01-01
A multiobjective computer-aided design algorithm has been developed which minimizes the sensitivity of the design objectives to uncertainties in system parameters. The more important uncertain parameters are described by a gaussian random vector with known covariance matrix, and a vector sensitivity objective function is defined as the probabilities that the design objectives will violate specified requirements constraints. Control system parameters are found which minimize the sensitivity vector in a Pareto-optimal sense, using constrained minimization algorithms. Example results are shown for lateral stability augmentation system (SAS) design for three Shuttle flight conditions.
Method for calculating the parameters of formation of hydrates from multicomponent gases
NASA Astrophysics Data System (ADS)
Zaporozhets, E. P.; Shostak, N. A.
2016-09-01
A model of hydrate formation in multicomponent gas-liquid water or ice systems including the exo- and endothermic processes has been suggested. Based on this model, a method for calculating the molecular and energy parameters such as the hydration number, amount of moles of hydrate, amount of gas and water in it, its density and molar mass, and the energy and rate of hydrate formation was developed. A comparison of the calculated and experimental values of the parameters revealed that the difference between them varied from 0 to 5.46%.
Tavernier, Elsa; Giraudeau, Bruno
2015-01-01
We aimed to examine the extent to which inaccurate assumptions for nuisance parameters used to calculate sample size can affect the power of a randomized controlled trial (RCT). In a simulation study, we separately considered an RCT with continuous, dichotomous or time-to-event outcomes, with associated nuisance parameters of standard deviation, success rate in the control group and survival rate in the control group at some time point, respectively. For each type of outcome, we calculated a required sample size N for a hypothesized treatment effect, an assumed nuisance parameter and a nominal power of 80%. We then assumed a nuisance parameter associated with a relative error at the design stage. For each type of outcome, we randomly drew 10,000 relative errors of the associated nuisance parameter (from empirical distributions derived from a previously published review). Then, retro-fitting the sample size formula, we derived, for the pre-calculated sample size N, the real power of the RCT, taking into account the relative error for the nuisance parameter. In total, 23%, 0% and 18% of RCTs with continuous, binary and time-to-event outcomes, respectively, were underpowered (i.e., the real power was < 60%, as compared with the 80% nominal power); 41%, 16% and 6%, respectively, were overpowered (i.e., with real power > 90%). Even with proper calculation of sample size, a substantial number of trials are underpowered or overpowered because of imprecise knowledge of nuisance parameters. Such findings raise questions about how sample size for RCTs should be determined.
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.
Tuning Parameters in Heuristics by Using Design of Experiments Methods
NASA Technical Reports Server (NTRS)
Arin, Arif; Rabadi, Ghaith; Unal, Resit
2010-01-01
With the growing complexity of today's large scale problems, it has become more difficult to find optimal solutions by using exact mathematical methods. The need to find near-optimal solutions in an acceptable time frame requires heuristic approaches. In many cases, however, most heuristics have several parameters that need to be "tuned" before they can reach good results. The problem then turns into "finding best parameter setting" for the heuristics to solve the problems efficiently and timely. One-Factor-At-a-Time (OFAT) approach for parameter tuning neglects the interactions between parameters. Design of Experiments (DOE) tools can be instead employed to tune the parameters more effectively. In this paper, we seek the best parameter setting for a Genetic Algorithm (GA) to solve the single machine total weighted tardiness problem in which n jobs must be scheduled on a single machine without preemption, and the objective is to minimize the total weighted tardiness. Benchmark instances for the problem are available in the literature. To fine tune the GA parameters in the most efficient way, we compare multiple DOE models including 2-level (2k ) full factorial design, orthogonal array design, central composite design, D-optimal design and signal-to-noise (SIN) ratios. In each DOE method, a mathematical model is created using regression analysis, and solved to obtain the best parameter setting. After verification runs using the tuned parameter setting, the preliminary results for optimal solutions of multiple instances were found efficiently.
Mission design applications of QUICK. [software for interactive trajectory calculation
NASA Technical Reports Server (NTRS)
Skinner, David L.; Bass, Laura E.; Byrnes, Dennis V.; Cheng, Jeannie T.; Fordyce, Jess E.; Knocke, Philip C.; Lyons, Daniel T.; Pojman, Joan L.; Stetson, Douglas S.; Wolf, Aron A.
1990-01-01
An overview of an interactive software environment for space mission design termed QUICK is presented. This stand-alone program provides a programmable FORTRAN-like calculator interface to a wide range of both built-in and user defined functions. QUICK has evolved into a general-purpose software environment that can be intrinsically and dynamically customized for a wide range of mission design applications. Specific applications are described for some space programs, e.g., the earth-Venus-Mars mission, the Cassini mission to Saturn, the Mars Observer, the Galileo Project, and the Magellan Spacecraft.
Mission design applications of QUICK. [software for interactive trajectory calculation
NASA Technical Reports Server (NTRS)
Skinner, David L.; Bass, Laura E.; Byrnes, Dennis V.; Cheng, Jeannie T.; Fordyce, Jess E.; Knocke, Philip C.; Lyons, Daniel T.; Pojman, Joan L.; Stetson, Douglas S.; Wolf, Aron A.
1990-01-01
An overview of an interactive software environment for space mission design termed QUICK is presented. This stand-alone program provides a programmable FORTRAN-like calculator interface to a wide range of both built-in and user defined functions. QUICK has evolved into a general-purpose software environment that can be intrinsically and dynamically customized for a wide range of mission design applications. Specific applications are described for some space programs, e.g., the earth-Venus-Mars mission, the Cassini mission to Saturn, the Mars Observer, the Galileo Project, and the Magellan Spacecraft.
Aerodynamic optimization by simultaneously updating flow variables and design parameters
NASA Technical Reports Server (NTRS)
Rizk, M. H.
1990-01-01
The application of conventional optimization schemes to aerodynamic design problems leads to inner-outer iterative procedures that are very costly. An alternative approach is presented based on the idea of updating the flow variable iterative solutions and the design parameter iterative solutions simultaneously. Two schemes based on this idea are applied to problems of correcting wind tunnel wall interference and optimizing advanced propeller designs. The first of these schemes is applicable to a limited class of two-design-parameter problems with an equality constraint. It requires the computation of a single flow solution. The second scheme is suitable for application to general aerodynamic problems. It requires the computation of several flow solutions in parallel. In both schemes, the design parameters are updated as the iterative flow solutions evolve. Computations are performed to test the schemes' efficiency, accuracy, and sensitivity to variations in the computational parameters.
Novel parameter-based flexure bearing design method
NASA Astrophysics Data System (ADS)
Amoedo, Simon; Thebaud, Edouard; Gschwendtner, Michael; White, David
2016-06-01
A parameter study was carried out on the design variables of a flexure bearing to be used in a Stirling engine with a fixed axial displacement and a fixed outer diameter. A design method was developed in order to assist identification of the optimum bearing configuration. This was achieved through a parameter study of the bearing carried out with ANSYS®. The parameters varied were the number and the width of the arms, the thickness of the bearing, the eccentricity, the size of the starting and ending holes, and the turn angle of the spiral. Comparison was made between the different designs in terms of axial and radial stiffness, the natural frequency, and the maximum induced stresses. Moreover, the Finite Element Analysis (FEA) was compared to theoretical results for a given design. The results led to a graphical design method which assists the selection of flexure bearing geometrical parameters based on pre-determined geometric and material constraints.
Validity test of design calculations of a PGNAA setup
NASA Astrophysics Data System (ADS)
Naqvi, A. A.; Garwan, M. A.
2004-01-01
A rectangular moderator has been designed for the prompt gamma ray neutron activation analysis (PGNAA) setup at King Fahd University of Petroleum and Minerals (KFUPM) to analyze Portland cement samples. The design of the moderator assembly was obtained using Monte Carlo calculations. The design calculations of the new rectangular moderator of the KFUPM PGNAA setup have been verified experimentally through prompt gamma ray yield measurement as a function of the front moderator thickness. In this study the yield of the 3.54 and 4.94 MeV prompt gamma rays from silicon in a soil sample was measured as a function of thickness of the front moderator of the rectangular moderator. The experimental results were compared with the results of the Monte Carlo simulations. A good agreement has been achieved between the experimental results and the results of the calculations. The experimental results have provided useful information about the PGNAA setup performance, neutron moderation, and gamma ray attenuation in the PGNAA sample.
An equation to calculate the actual methylene middle parameter as a function of temperature.
Mohammad, Mohammad Amin
2015-08-21
Methylene middle parameter [Formula: see text] , the product of the methylene group's cross-sectional area ( [Formula: see text] ) and the root square of its dispersive free energy ( [Formula: see text] ), is the key parameter to calculate the dispersive surface components of solids (γs(d)) using inverse gas chromatography (IGC) at different temperatures. The only method reported to calculate [Formula: see text] as a function of temperature is the Dorris-Gray method. However, the conventional values of [Formula: see text] calculated by the Dorris-Gray method depend heavily on theoretical aspects. This paper establishes a novel equation calculating the actual [Formula: see text] as a function of temperature using the latest and most accurate surface parameters of seven successive n-alkanes. The obtained actual [Formula: see text] values are slightly higher those of the conventional [Formula: see text] . At 20°C, the actual [Formula: see text] generates γs(d) values less than those generated using the conventional [Formula: see text] by ∼3%, and this reduction in calculated γs(d) values increases linearly to become ∼5% at 100°C. Therefore, using the new actual [Formula: see text] seems to mitigate the discrepancy between the γs(d) values measured by IGC and those measured by the contact angle method. Copyright © 2015 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Prilutskii, A. I.; Prilutskii, I. K.; Makoveeva, A. S.; Prilutskii, A. A.
2017-08-01
The article deals with some improper performance reasons of reciprocating compressors which are in year-round operation. The possibilities and recommendations for design optimization of some details and components and compressor operating parameters under existing industry conditions by means of the upgraded volumetric machine calculation program KOMDET-M designed for analyzing processes occurring in volumetric machines are represented. The calculation result agreement with parameters claimed by vendor and actual ones of gas reciprocating compressors which are in operation is shown. The scientific and practical value of the research for any designed, upgradable or operating unit is demonstrated. Necessary calculations have been performed by means of the application calculation program. Some examples of volumetric machine reliability and efficiency improvement are represented.
Calculation of electron-beam induced displacement in thin films by using parameter-reduced formulas
NASA Astrophysics Data System (ADS)
Yan, Qiang; Chen, Di; Wang, Qingyu; Li, Zhongyu; Shao, Lin
2017-03-01
Based on the Mott cross sections of relativistic electron collisions with atoms, we calculate displacement creation by electron beams of arbitrary energies (up to 100 MeV) in thin films of arbitrary atomic numbers (up to Z = 90). In a comparison with Mont Carlo full damage cascade simulations, we find that total number of displacements in a film can be accurately estimated as the product of average displacements created per collision and average collision numbers in the film. To calculate average displacements per electron-atom collision, energy transfer from Mott cross section is combined with NRT model. To calculate collision numbers, mean deflection angles and multi-scattering theory are combined to extract collision number dependence on film thickness. For each key parameter, parameter-reduced formulas are obtained from data fitting. The fitting formulas provide a quick and accurate method to estimate radiation damage caused by electron beams.
Dobos, A. P.
2012-05-01
This paper describes an improved algorithm for calculating the six parameters required by the California Energy Commission (CEC) photovoltaic (PV) Calculator module model. Rebate applications in California require results from the CEC PV model, and thus depend on an up-to-date database of module characteristics. Currently, adding new modules to the database requires calculating operational coefficients using a general purpose equation solver - a cumbersome process for the 300+ modules added on average every month. The combination of empirical regressions and heuristic methods presented herein achieve automated convergence for 99.87% of the 5487 modules in the CEC database and greatly enhance the accuracy and efficiency by which new modules can be characterized and approved for use. The added robustness also permits general purpose use of the CEC/6 parameter module model by modelers and system analysts when standard module specifications are known, even if the module does not exist in a preprocessed database.
Capote, R.; Herman, M.; Capote,R.; Herman,M.; Oblozinsky,P.; Young,P.G.; Goriely,S.; Belgy,T.; Ignatyuk,A.V.; Koning,A.J.; Hilaire,S.; Pljko,V.A.; Avrigeanu,M.; Bersillon,O.; Chadwick,M.B.; Fukahori,T.; Ge, Zhigang; Han,Yinl,; Kailas,S.; Kopecky,J.; Maslov,V.M.; Reffo,G.; Sin,M.; Soukhovitskii,E.Sh.; Talou,P
2009-12-01
We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through http://www-nds.iaea.org/RIPL-3/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and {gamma}-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains
Capote, R. , E-Mail: r.capotenoy@iaea.org; Herman, M.; Oblozinsky, P.; Young, P.G.; Goriely, S.; Belgya, T.; Ignatyuk, A.V.; Koning, A.J.; Hilaire, S.; Plujko, V.A.; Avrigeanu, M.; Bersillon, O.; Chadwick, M.B.; Fukahori, T.; Ge, Zhigang; Han, Yinlu; Kailas, S.; Kopecky, J.; Maslov, V.M.; Reffo, G.
2009-12-15
We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through (http://www-nds.iaea.org/RIPL-3/). This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and {gamma}-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains
NASA Astrophysics Data System (ADS)
Capote, R.; Herman, M.; Obložinský, P.; Young, P. G.; Goriely, S.; Belgya, T.; Ignatyuk, A. V.; Koning, A. J.; Hilaire, S.; Plujko, V. A.; Avrigeanu, M.; Bersillon, O.; Chadwick, M. B.; Fukahori, T.; Ge, Zhigang; Han, Yinlu; Kailas, S.; Kopecky, J.; Maslov, V. M.; Reffo, G.; Sin, M.; Soukhovitskii, E. Sh.; Talou, P.
2009-12-01
We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through http://www-nds.iaea.org/RIPL-3/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and γ-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains
Use Of Programmable Calculators In Lens Design And Analysis
NASA Astrophysics Data System (ADS)
Beckmann, Leo H.
1983-10-01
For several years the hand-held programmable calculator has been known to be an attractive tool for solving some relatively simple problems in optical computation, such as general ray tracing, first order optics and optical system analysis. The range of application can however, be extended far beyond this level and includes the semi-automatic design of unsophisticated optical imaging systems such as the air-spaced doublet and the Cooke triplet, for which examples are presented. In view of the limitations in the number of program steps, it is mandatory to implement such programs with utmost economy of use of these program steps and to utilize the inherent properties of these optical systems in order to obtain convergence in the automatic design. improvement part of the programs. While the most appropriate application may be in supporting the teaching of elementary lens design, these calculator programs can be quite helpful if relatively simple optical systems have to be designed without as access to a large computer facility and associated software.
Programmable Calculators: Their Use In Lens Design And Analysis
NASA Astrophysics Data System (ADS)
Beckmann, Leo H. J. F.
1985-08-01
For several years the hand-held programmable calculator has been known to be an attractive tool for solving some relatively simple problems in optical computation, such as general ray tracing, first-order optics, and optical system analysis. The range of application, however, can be extended far beyond this level and includes the semiautomatic design of unsophisticated optical imaging systems such as the air-spaced doublet and the Cooke triplet, for which examples are presented. In view of the limitations in the number of program steps, it is mandatory to implement such programs with utmost economy of use of these program steps and to utilize the inherent properties of these optical systems in order to obtain convergence in the automatic design improvement part of the programs. While the most appropriate application may be in support-ing the teaching of elementary lens design, these calculator programs can be quite helpful if relatively simple optical systems have to be designed without easy access to a large computer facility and associated software.
NASA Astrophysics Data System (ADS)
Xiu, Wanjing; Liao, Yuan
2014-12-01
Transmission lines are essential components of electric power grids. Diverse power system applications and simulation based studies require transmission line parameters including series resistance, reactance, and shunt susceptance, and accurate parameters are pivotal in ensuring the accuracy of analyses and reliable system operation. Commercial software packages for performing power system studies usually have their own databases that store the power system model including line parameters. When there is a physical system model change, the corresponding component in the database of the software packages will need to be modified. Manually updating line parameters are tedious and error-prone. This paper proposes a solution for streamlining the calculation of line parameters and updating of their values in respective software databases. The algorithms used for calculating the values of line parameters are described. The software developed for implementing the solution is described, and typical results are presented. The proposed solution is developed for a utility and has a potential to be put into use by other utilities.
[Specific parameters for the calculation of dose after aerosol inhalation of transuranium elements].
Ramounet-Le Gall, B; Fritsch, P; Abram, M C; Rateau, G; Grillon, G; Guillet, K; Baude, S; Bérard, P; Ansoborlo, E; Delforge, J
2002-07-01
A review on specific parameter measurements to calculate doses per unit of incorporation according to recommendations of the International Commission of Radiological Protection has been performed for inhaled actinide oxides. Alpha activity distribution of the particles can be obtained by autoradiography analysis using aerosol sampling filters at the work places. This allows us to characterize granulometric parameters of "pure" actinide oxides, but complementary analysis by scanning electron microscopy is needed for complex aerosols. Dissolution parameters with their standard deviation are obtained after rat inhalation exposure, taking into account both mechanical lung clearance and actinide transfer to the blood estimated from bone retention. In vitro experiments suggest that the slow dissolution rate might decrease as a function of time following exposure. Dose calculation software packages have been developed to take into account granulometry and dissolution parameters as well as specific physiological parameters of exposed individuals. In the case of poorly soluble actinide oxides, granulometry and physiology appear as the main parameters controlling dose value, whereas dissolution only alters dose distribution. Validation of these software packages are in progress.
Hybrid functional calculations on the band gap bowing parameters of In x Ga1-x N
NASA Astrophysics Data System (ADS)
Mei, Lin; Yixu, Xu; Jianhua, Zhang; Shunqing, Wu; Zizhong, Zhu
2016-04-01
The electronic band structures and band gap bowing parameters of In x Ga1-x N are studied by the first-principles method based on the density functional theory. Calculations by employing both the Heyd-Scuseria-Ernzerh of hybrid functional (HSE06) and the Perdew-Burke-Ernzerhof (PBE) one are performed. We found that the theoretical band gap bowing parameter is dependent significantly on the calculation method, especially on the exchange-correlation functional employed in the DFT calculations. The band gap of In x Ga1-x N alloy decreases considerably when the In constituent x increases. It is the interactions of s-s and p-p orbitals between anions and cations that play significant roles in formatting the band gaps bowing. In general, the HSE06 hybrid functional could provide a good alternative to the PBE functional in calculating the band gap bowing parameters. Project supported by the National Natural Science Foundation of China (Nos. 11204257, 21233004) and the China Postdoctoral Science Foundation (No. 2012M511447).
Integration based profile likelihood calculation for PDE constrained parameter estimation problems
NASA Astrophysics Data System (ADS)
Boiger, R.; Hasenauer, J.; Hroß, S.; Kaltenbacher, B.
2016-12-01
Partial differential equation (PDE) models are widely used in engineering and natural sciences to describe spatio-temporal processes. The parameters of the considered processes are often unknown and have to be estimated from experimental data. Due to partial observations and measurement noise, these parameter estimates are subject to uncertainty. This uncertainty can be assessed using profile likelihoods, a reliable but computationally intensive approach. In this paper, we present the integration based approach for the profile likelihood calculation developed by (Chen and Jennrich 2002 J. Comput. Graph. Stat. 11 714-32) and adapt it to inverse problems with PDE constraints. While existing methods for profile likelihood calculation in parameter estimation problems with PDE constraints rely on repeated optimization, the proposed approach exploits a dynamical system evolving along the likelihood profile. We derive the dynamical system for the unreduced estimation problem, prove convergence and study the properties of the integration based approach for the PDE case. To evaluate the proposed method, we compare it with state-of-the-art algorithms for a simple reaction-diffusion model for a cellular patterning process. We observe a good accuracy of the method as well as a significant speed up as compared to established methods. Integration based profile calculation facilitates rigorous uncertainty analysis for computationally demanding parameter estimation problems with PDE constraints.
Total energy control system autopilot design with constrained parameter optimization
NASA Technical Reports Server (NTRS)
Ly, Uy-Loi; Voth, Christopher
1990-01-01
A description is given of the application of a multivariable control design method (SANDY) based on constrained parameter optimization to the design of a multiloop aircraft flight control system. Specifically, the design method is applied to the direct synthesis of a multiloop AFCS inner-loop feedback control system based on total energy control system (TECS) principles. The design procedure offers a structured approach for the determination of a set of stabilizing controller design gains that meet design specifications in closed-loop stability, command tracking performance, disturbance rejection, and limits on control activities. The approach can be extended to a broader class of multiloop flight control systems. Direct tradeoffs between many real design goals are rendered systematic by proper formulation of the design objectives and constraints. Satisfactory designs are usually obtained in few iterations. Performance characteristics of the optimized TECS design have been improved, particularly in the areas of closed-loop damping and control activity in the presence of turbulence.
Sequential ensemble-based optimal design for parameter estimation
NASA Astrophysics Data System (ADS)
Man, Jun; Zhang, Jiangjiang; Li, Weixuan; Zeng, Lingzao; Wu, Laosheng
2016-10-01
The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees of freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.
Nurzyńska, Katarzyna; Booth, Jonathan; Roberts, Clive J; McCabe, James; Dryden, Ian; Fischer, Peter M
2015-09-08
The purpose of this study was to develop a predictive model of the amorphous stability of drugs with particular relevance for poorly water-soluble compounds. Twenty-five representative neutral poorly soluble compounds with a diverse range of physicochemical properties and chemical structures were systematically selected from an extensive library of marketed drug products. The physical stability of the amorphous form, measured over a 6 month period by the onset of crystallization of amorphous films prepared by melting and quench-cooling, was assessed using polarized light microscopy. The data were used as a response variable in a statistical model with calculated/predicted or measured molecular, thermodynamic, and kinetic parameters as explanatory variables. Several multiple linear regression models were derived, with varying balance between calculated/predicted and measured parameters. It was shown that inclusion of measured parameters significantly improves the predictive ability of the model. The best model demonstrated a prediction accuracy of 82% and included the following as parameters: melting and glass transition temperatures, enthalpy of fusion, configurational free energy, relaxation time, number of hydrogen bond donors, lipophilicity, and the ratio of carbon to heteroatoms. Good predictions were also obtained with a simpler model, which was comprised of easily acquired quantities: molecular weight and enthalpy of fusion. Statistical models are proposed to predict long-term amorphous drug stability. The models include readily accessible parameters, which are potentially the key factors influencing amorphous stability. The derived models can support faster decision making in drug formulation development.
k.p Parameters with Accuracy Control from Preexistent First-Principles Band Structure Calculations
NASA Astrophysics Data System (ADS)
Sipahi, Guilherme; Bastos, Carlos M. O.; Sabino, Fernando P.; Faria Junior, Paulo E.; de Campos, Tiago; da Silva, Juarez L. F.
The k.p method is a successful approach to obtain band structure, optical and transport properties of semiconductors. It overtakes the ab initio methods in confined systems due to its low computational cost since it is a continuum method that does not require all the atoms' orbital information. From an effective one-electron Hamiltonian, the k.p matrix representation can be calculated using perturbation theory and the parameters identified by symmetry arguments. The parameters determination, however, needs a complementary approach. In this paper, we developed a general method to extract the k.p parameters from preexistent band structures of bulk materials that is not limited by the crystal symmetry or by the model. To demonstrate our approach, we applied it to zinc blende GaAs band structure calculated by hybrid density functional theory within the Heyd-Scuseria-Ernzerhof functional (DFT-HSE), for the usual 8 ×8 k.p Hamiltonian. Our parameters reproduced the DFT-HSE band structure with great accuracy up to 20% of the first Brillouin zone (FBZ). Furthermore, for fitting regions ranging from 7-20% of FBZ, the parameters lie inside the range of values reported by the most reliable studies in the literature. The authors acknowledge financial support from the Brazilian agencies CNPq (Grant #246549/2012-2) and FAPESP (Grants #2011/19333-4, #2012/05618-0 and #2013/23393-8).
Thermodynamics calculation of protein-ligand interactions by QM/MM polarizable charge parameters.
Wang, Jinan; Shao, Qiang; Cossins, Benjamin P; Shi, Jiye; Chen, Kaixian; Zhu, Weiliang
2016-01-01
The calculation of protein-ligand binding free energy (ΔG) is of great importance for virtual screening and drug design. Molecular dynamics (MD) simulation has been an attractive tool to investigate this scientific problem. However, the reliability of such approach is affected by many factors including electrostatic interaction calculation. Here, we present a practical protocol using quantum mechanics/molecular mechanics (QM/MM) calculations to generate polarizable QM protein charge (QMPC). The calculated QMPC of some atoms in binding pockets was obviously different from that calculated by AMBER ff03, which might significantly affect the calculated ΔG. To evaluate the effect, the MD simulations and MM/GBSA calculation with QMPC for 10 protein-ligand complexes, and the simulation results were then compared to those with the AMBER ff03 force field and experimental results. The correlation coefficient between the calculated ΔΔG using MM/GBSA under QMPC and the experimental data is .92, while that with AMBER ff03 force field is .47 for the complexes formed by streptavidin or its mutants and biotin. Moreover, the calculated ΔΔG with QMPC for the complexes formed by ERβ and five ligands is positively related to experimental result with correlation coefficient of .61, while that with AMBER ff03 charge is negatively related to experimental data with correlation coefficient of .42. The detailed analysis shows that the electrostatic polarization introduced by QMPC affects the electrostatic contribution to the binding affinity and thus, leads to better correlation with experimental data. Therefore, this approach should be useful to virtual screening and drug design.
Loss of Information in Estimating Item Parameters in Incomplete Designs
ERIC Educational Resources Information Center
Eggen, Theo J. H. M.; Verelst, Norman D.
2006-01-01
In this paper, the efficiency of conditional maximum likelihood (CML) and marginal maximum likelihood (MML) estimation of the item parameters of the Rasch model in incomplete designs is investigated. The use of the concept of F-information (Eggen, 2000) is generalized to incomplete testing designs. The scaled determinant of the F-information…
Loss of Information in Estimating Item Parameters in Incomplete Designs
ERIC Educational Resources Information Center
Eggen, Theo J. H. M.; Verelst, Norman D.
2006-01-01
In this paper, the efficiency of conditional maximum likelihood (CML) and marginal maximum likelihood (MML) estimation of the item parameters of the Rasch model in incomplete designs is investigated. The use of the concept of F-information (Eggen, 2000) is generalized to incomplete testing designs. The scaled determinant of the F-information…
Calculation and designing of volutes of rotodynamic pumps
NASA Astrophysics Data System (ADS)
Krishtop, I. V.; Kalinichenko, P. M.; Gusak, A. G.
2017-08-01
This work deals with improvements of the calculation and design methods of rotodynamic pump volutes taking into account viscous liquid flow. The research was performed with torque flow pump of “Turo” type. The analytical solution for the problem within the one-dimensional model of viscous liquid allowed to obtain a viscous liquid flow pattern in the volute. The law of velocity variation of viscous liquid flowing through the volute was obtained. There are numerical solutions of the problem concerning of viscous liquid flow in the pump with volute designed for traditional model of non viscous and viscous fluid. The research results are given by means of head-capacity and power input curves. To estimate the results of numerical study the tests were performed on the test stand.
The calculation of some gamma shielding parameters for semiconductor CsPbBr3
NASA Astrophysics Data System (ADS)
Oto, Berna; Gulebaglan, Sinem Erden; Kanberoglu, Gulsah Saydan
2017-02-01
Recently, researchers produced perovskites structures used in optoelectronic devices as substrates, sensors. CsPbBr3 crystal is found in the cubic perovskite structure and its space group is Pm-3m. CsPbBr3 is a developing material for detection of X- and γ-ray radiations and the knowledge of the attenuation parameters of CsPbBr3 crystal is important. In this study, some photon shielding parameters such as mass attenuation coefficient (μρ), effective atomic number (Zeff) and electron density (Nel) have been investigated for CsPbBr3 compound. The theoretical values of μρ have been calculated in the energy range from 1 keV to 100 GeV using WinXCom computer code and these values have been used in order to calculate the values of Zeff and Nel in the same energy range.
Niu, Sheng-Li; Huo, Meng-Jia; Lu, Chun-Mei; Liu, Meng-Qi; Li, Hui
2014-04-01
The catalytic capacity of dolomite in transesterification was investigated and the kinetic parameters were calculated. The activated dolomites as transesterification catalyst were characterized by X-ray diffraction, nitrogen adsorption and desorption and Hammett indicator method, where the original dolomite was analyzed by thermogravimetric and X-ray fluorescence in advance. Its potential catalytic capacity was validated from aspects of the activated temperature and the reused property, where the reliability of the experimental system was also examined. Then, influences of the catalyst added amount, the mole ratio of methanol to oil, the transesterification temperature and the transesterification time on the catalytic capacity were investigated. Finally, kinetic parameters of the transesterification catalyzed by the activated dolomite were calculated.
Design parameters for the damped detuned accelerating structure
Ko, K.; Bane, K.; Gluckstern, R.; Hoag, H.; Kroll, N.; Lin, X.T.; Miller, R.; Ruth, R.; Thompson, K.; Wang, J. ||
1995-06-01
The advanced accelerating cavities for the NLCTA (and anticipated for NLC) will incorporate damping as well as detuning. The damping is provided by a set of four waveguides (which also serve as pumping manifolds) that run parallel to the structure, with strong iris coupling to each cavity cell and terminated at each end by absorbers. The previously reported equivalent circuit analysis has been refined and the dependence upon design parameters explored. The authors find that adequate damping can be provided by a single waveguide mode, leading to designs which are more compact than those initially considered. The design parameters and their rationale will be presented.
Design parameters and source terms: Volume 3, Source terms
Not Available
1987-10-01
The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository in Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites. 11 refs., 9 tabs.
Kwak, Dai Soon; Tao, Quang Bang; Todo, Mitsugu; Jeon, Insu
2012-05-01
Knee joint implants developed by western companies have been imported to Korea and used for Korean patients. However, many clinical problems occur in knee joints of Korean patients after total knee joint replacement owing to the geometric mismatch between the western implants and Korean knee joint structures. To solve these problems, a method to determine the representative dimension parameter values of Korean knee joints is introduced to aid in the design of knee joint implants appropriate for Korean patients. Measurements of the dimension parameters of 88 male Korean knee joint subjects were carried out. The distribution of the subjects versus each measured parameter value was investigated. The measured dimension parameter values of each parameter were grouped by suitable intervals called the "size group," and average values of the size groups were calculated. The knee joint subjects were grouped as the "patient group" based on "size group numbers" of each parameter. From the iterative calculations to decrease the errors between the average dimension parameter values of each "patient group" and the dimension parameter values of the subjects, the average dimension parameter values that give less than the error criterion were determined to be the representative dimension parameter values for designing knee joint implants for Korean patients.
NASA Astrophysics Data System (ADS)
Tokunaga, Yoshitaka; Kubota, Kunihiro
This paper presents estimation techniques of machine parameters for two windings power transformer using design procedure of winding structure. Especially, it is very difficult to obtain machine parameters for transformers in customers' facilities. Using estimation techniques, machine parameters could be calculated from the only nameplate data of these transformers. Subsequently, EMTP-ATP simulation of the inrush current was carried out using machine parameters estimated by design procedure of winding structure and simulation results were reproduced measured waveforms.
Concurrent optimization of airframe and engine design parameters
NASA Technical Reports Server (NTRS)
Lavelle, Thomas M.; Plencner, Robert M.; Seidel, Jonathan A.
1991-01-01
An integrated system for the multidisciplinary analysis and optimization of airframe and propulsion design parameters is being developed. This system is known as IPAS, the Integrated Propulsion/Airframe Analysis System. The traditional method of analysis is one in which the propulsion system analysis is loosely coupled to the overall mission performance analysis. This results in a time consuming iterative process. First, the engine is designed and analyzed. Then, the results from this analysis are used in a mission analysis to determine the overall aircraft performance. The results from the mission analysis are used as a guide as the engine is redesigned and the entire process repeated. In IPAS, the propulsion system, airframe, and mission are closely coupled. The propulsion system analysis code is directly integrated into the mission analysis code. This allows the propulsion design parameters to be optimized along with the airframe and mission design parameters, significantly reducing the time required to obtain an optimized solution.
NASA Astrophysics Data System (ADS)
Pavlov, A. V.; Sitnov, Iu. S.
1985-10-01
Pavlov's (1984) method is used to determine the relative errors (due to errors in measuring the input parameters of the model) in theoretical calculations of the main parameters of the daytime F2-layer under quiet conditions. The parameters calculated are the height of the F2-layer maximum and the electron density.
Parameter-free effective field theory calculation for the solar proton-fusion and hep processes
T.S. Park; L.E. Marcucci; R. Schiavilla; M. Viviani; A. Kievsky; S. Rosati; K. Kubodera; D.P. Min; M. Rho
2002-08-01
Spurred by the recent complete determination of the weak currents in two-nucleon systems up to {Omicron}(Q{sup 3}) in heavy-baryon chiral perturbation theory, we carry out a parameter-free calculation of the threshold S-factors for the solar pp (proton-fusion) and hep processes in an effective field theory that combines the merits of the standard nuclear physics method and systematic chiral expansion. The power of the EFT adopted here is that one can correlate in a unified formalism the weak-current matrix elements of two-, three- and four-nucleon systems. Using the tritium {beta}-decay rate as an input to fix the only unknown parameter in the theory, we can evaluate the threshold S factors with drastically improved precision; the results are S{sub pp}(0) = 3.94 x (1 {+-} 0.004) x 10{sup -25} MeV-b and S{sub hep}(0) = (8.6 {+-} 1.3) x 10{sup -20} keV-b. The dependence of the calculated S-factors on the momentum cutoff parameter {Lambda} has been examined for a physically reasonable range of {Lambda}. This dependence is found to be extremely small for the pp process, and to be within acceptable levels for the hep process, substantiating the consistency of our calculational scheme.
Relativistic Calculation of Scattering Parameters for Superelastic Electron-Atom Collisions
NASA Astrophysics Data System (ADS)
Zeman, V.; McEachran, R. P.; Stauffer, A. D.; Srivastava, R.
1996-05-01
Superelastic electron-atom scattering experiments are often more desirable to perform than inelastic experiments, in part due to the ability to excite specific fine-structure (and hyperfine-structure) states with relative ease. The superelastic scattering parameters measured, however, are often compared with inelastic parameters which have been measured or calculated by other groups, even though the two cases are not exactly the time-reverse of each other (inelastic experiments can't resolve hyperfine-structure states). To do this there must exist a theoretical framework by which the various parameters for the two cases can be compared. In the non-relativistic limit a general framework has been developed for n'p arrow ns transitions in quasi one-electron atoms(I.V. Hertel, M.H. Kelley and J.J. McClelland, Z. Phys. D, 6), 163 (1987). We extend these calculations to the relativistic case where jj-coupling, rather than LS-coupling, is employed. Examples of calculations using the relativistic distorted-wave approximation will be given.
Calculation of pressure broadening parameters for the CO-He system at low temperatures
NASA Technical Reports Server (NTRS)
Green, S.
1985-01-01
Theoretical pressure broadening parameters were computed for the 0-1 and 1-2 rotational transitions of CO in He at very low temperatures and compared with the recent experimental measurements at 4.2 K. The interaction potential was taken from extensive SCF-CI calculations, molecular collision dynamics were described by essentially exact converged close coupling calculations, and pressure broadening cross sections were obtained from the collisional S matrices within the accurate Fano-Ben Reuven framework. Resonances at low collision energies give rise to an increase in the thermally averaged cross sections at low temperatures. Although previous calculations for this system at higher temperatures (77-300 K) were in good accord with experiment, at 4.2 K predicted values are about two times larger than experiment; possible sources of this discrepancy are discussed.
Parsons, Tom
2008-01-01
Paleoearthquake observations often lack enough events at a given site to directly define a probability density function (PDF) for earthquake recurrence. Sites with fewer than 10-15 intervals do not provide enough information to reliably determine the shape of the PDF using standard maximum-likelihood techniques [e.g., Ellsworth et al., 1999]. In this paper I present a method that attempts to fit wide ranges of distribution parameters to short paleoseismic series. From repeated Monte Carlo draws, it becomes possible to quantitatively estimate most likely recurrence PDF parameters, and a ranked distribution of parameters is returned that can be used to assess uncertainties in hazard calculations. In tests on short synthetic earthquake series, the method gives results that cluster around the mean of the input distribution, whereas maximum likelihood methods return the sample means [e.g., NIST/SEMATECH, 2006]. For short series (fewer than 10 intervals), sample means tend to reflect the median of an asymmetric recurrence distribution, possibly leading to an overestimate of the hazard should they be used in probability calculations. Therefore a Monte Carlo approach may be useful for assessing recurrence from limited paleoearthquake records. Further, the degree of functional dependence among parameters like mean recurrence interval and coefficient of variation can be established. The method is described for use with time-independent and time-dependent PDF?s, and results from 19 paleoseismic sequences on strike-slip faults throughout the state of California are given.
Parsons, T.
2008-01-01
Paleoearthquake observations often lack enough events at a given site to directly define a probability density function (PDF) for earthquake recurrence. Sites with fewer than 10-15 intervals do not provide enough information to reliably determine the shape of the PDF using standard maximum-likelihood techniques (e.g., Ellsworth et al., 1999). In this paper I present a method that attempts to fit wide ranges of distribution parameters to short paleoseismic series. From repeated Monte Carlo draws, it becomes possible to quantitatively estimate most likely recurrence PDF parameters, and a ranked distribution of parameters is returned that can be used to assess uncertainties in hazard calculations. In tests on short synthetic earthquake series, the method gives results that cluster around the mean of the input distribution, whereas maximum likelihood methods return the sample means (e.g., NIST/SEMATECH, 2006). For short series (fewer than 10 intervals), sample means tend to reflect the median of an asymmetric recurrence distribution, possibly leading to an overestimate of the hazard should they be used in probability calculations. Therefore a Monte Carlo approach may be useful for assessing recurrence from limited paleoearthquake records. Further, the degree of functional dependence among parameters like mean recurrence interval and coefficient of variation can be established. The method is described for use with time-independent and time-dependent PDFs, and results from 19 paleoseismic sequences on strike-slip faults throughout the state of California are given.
Mali, Gregor
2017-03-01
Ab initio prediction of sensible crystal structures can be regarded as a crucial task in the quickly-developing methodology of NMR crystallography. In this contribution, an evolutionary algorithm was used for the prediction of magnesium (poly)sulfide crystal structures with various compositions. The employed approach successfully identified all three experimentally detected forms of MgS, i.e. the stable rocksalt form and the metastable wurtzite and zincblende forms. Among magnesium polysulfides with a higher content of sulfur, the most probable structure with the lowest formation energy was found to be MgS2, exhibiting a modified rocksalt structure, in which S(2-) anions were replaced by S2(2-) dianions. Magnesium polysulfides with even larger fractions of sulfur were not predicted to be stable. For the lowest-energy structures, (25)Mg quadrupolar coupling constants and chemical shift parameters were calculated using the density functional theory approach. The calculated NMR parameters could be well rationalized by the symmetries of the local magnesium environments, by the coordination of magnesium cations and by the nature of the surrounding anions. In the future, these parameters could serve as a reference for the experimentally determined (25)Mg NMR parameters of magnesium sulfide species.
Ince, M; Yildiz, F; Engin, G Onkal; Engin, S N; Keskinler, B
2008-05-30
A novel circulating jet loop bioreactor adapted for organic matter oxidation has been designed and constructed. In this study, the input was leachate samples collected from Kemerburgaz Odayeri waste landfill site located on the European side of Istanbul. Controlling the jet loop bioreactor to realize high rates of purification depends on maintaining the appropriate loadings and operating conditions. This requires collecting various system data to estimate the dynamics of the system satisfactorily with the aim of keeping certain parameters within the specified range. The differential transform method (DTM) based solution of the state equations reveals the current state of the process so that any deviation in the system parameters can be immediately detected and regulated accordingly. The respirometric method for kinetic parameter calculations for biodegradation has been used for some time. In many studies, the respirometer was designed separately, usually in bench-scale. However, when a separate respirometer is used, the scale effect and parameters that affect the hydrodynamic structure of the system should be taken into consideration. In this study, therefore, the jet loop reactor itself was used as a respirometer. Thus, the kinetic parameters found reflecting the characteristics of microorganisms used for biodegradation would be more realistic. If the main reactor, here the jet loop reactor, would be used as the respirometer, the kinetic parameter changes can easily be monitored in the long run. Using the bioreactor as a respirometer, the most important kinetic parameters, Ks, kd and micromax were found to be 11,000 mg L(-1), 0.019 day(-1), and 0.21 day(-1), respectively. The stoichiometric coefficient, Y, was found to be 0.28 gr gr(-1) for the present system.
Lopes, Antonio Augusto; dos Anjos Miranda, Rogério; Gonçalves, Rilvani Cavalcante; Thomaz, Ana Maria
2009-01-01
BACKGROUND: In patients with congenital heart disease undergoing cardiac catheterization for hemodynamic purposes, parameter estimation by the indirect Fick method using a single predicted value of oxygen consumption has been a matter of criticism. OBJECTIVE: We developed a computer-based routine for rapid estimation of replicate hemodynamic parameters using multiple predicted values of oxygen consumption. MATERIALS AND METHODS: Using Microsoft® Excel facilities, we constructed a matrix containing 5 models (equations) for prediction of oxygen consumption, and all additional formulas needed to obtain replicate estimates of hemodynamic parameters. RESULTS: By entering data from 65 patients with ventricular septal defects, aged 1 month to 8 years, it was possible to obtain multiple predictions for oxygen consumption, with clear between-age groups (P <.001) and between-methods (P <.001) differences. Using these predictions in the individual patient, it was possible to obtain the upper and lower limits of a likely range for any given parameter, which made estimation more realistic. CONCLUSION: The organized matrix allows for rapid obtainment of replicate parameter estimates, without error due to exhaustive calculations. PMID:19641642
Stereolithographic Bone Scaffold Design Parameters: Osteogenic Differentiation and Signal Expression
Kim, Kyobum; Yeatts, Andrew; Dean, David
2010-01-01
Scaffold design parameters including porosity, pore size, interconnectivity, and mechanical properties have a significant influence on osteogenic signal expression and differentiation. This review evaluates the influence of each of these parameters and then discusses the ability of stereolithography (SLA) to be used to tailor scaffold design to optimize these parameters. Scaffold porosity and pore size affect osteogenic cell signaling and ultimately in vivo bone tissue growth. Alternatively, scaffold interconnectivity has a great influence on in vivo bone growth but little work has been done to determine if interconnectivity causes changes in signaling levels. Osteogenic cell signaling could be also influenced by scaffold mechanical properties such as scaffold rigidity and dynamic relationships between the cells and their extracellular matrix. With knowledge of the effects of these parameters on cellular functions, an optimal tissue engineering scaffold can be designed, but a proper technology must exist to produce this design to specification in a repeatable manner. SLA has been shown to be capable of fabricating scaffolds with controlled architecture and micrometer-level resolution. Surgical implantation of these scaffolds is a promising clinical treatment for successful bone regeneration. By applying knowledge of how scaffold parameters influence osteogenic cell signaling to scaffold manufacturing using SLA, tissue engineers may move closer to creating the optimal tissue engineering scaffold. PMID:20504065
Tych, Katarzyna M; Hughes, Megan L; Bourke, James; Taniguchi, Yukinori; Kawakami, Masaru; Brockwell, David J; Dougan, Lorna
2015-01-01
Single-molecule force spectroscopy using an atomic force microscope (AFM) can be used to measure the average unfolding force of proteins in a constant velocity experiment. In combination with Monte Carlo simulations and through the application of the Zhurkov-Bell model, information about the parameters describing the underlying unfolding energy landscape of the protein can be obtained. Using this approach, we have completed protein unfolding experiments on the polyprotein (I27)(5) over a range of pulling velocities. In agreement with previous work, we find that the observed number of protein unfolding events observed in each approach-retract cycle varies between one and five, due to the nature of the interactions between the polyprotein, the AFM tip, and the substrate, and there is an unequal unfolding probability distribution. We have developed a Monte Carlo simulation that incorporates the impact of this unequal unfolding probability distribution on the median unfolding force and the calculation of the protein unfolding energy landscape parameters. These results show that while there is a significant, unequal unfolding probability distribution, the unfolding energy landscape parameters obtained from use of the Zhurkov-Bell model are not greatly affected. This result is important because it demonstrates that the minimum acceptance criteria typically used in force extension experiments are justified and do not skew the calculation of the unfolding energy landscape parameters. We further validate this approach by determining the error in the energy landscape parameters for two extreme cases, and we provide suggestions for methods that can be employed to increase the level of accuracy in single-molecule experiments using polyproteins.
Control design for a class of nonlinear parameter varying systems
NASA Astrophysics Data System (ADS)
Cai, Xiushan; Liu, Yang; Zhang, Wei
2015-07-01
Stabilisation for a class of one-sided Lipschitz nonlinear parameter varying systems is dealt with in this paper. First, the nonlinear parameter varying system is represented as a subsystem of a differential inclusion. Sufficient conditions for exponential stabilisation for the differential inclusion are given by solving linear matrix inequalities. Then a continuous control law is designed to stabilise the differential inclusion. It leads to stabilising the nonlinear parameter varying system. Finally, a simulation example is presented to show the validity and advantages of the proposed method.
Parameters and variables appearing in repository design models
Curtis, R.H.; Wart, R.J.
1983-12-01
This report defines the parameters and variables appearing in repository design models and presents typical values and ranges of values of each. Areas covered by this report include thermal, geomechanical, and coupled stress and flow analyses in rock. Particular emphasis is given to conductivity, radiation, and convection parameters for thermal analysis and elastic constants, failure criteria, creep laws, and joint properties for geomechanical analysis. The data in this report were compiled to help guide the selection of values of parameters and variables to be used in code benchmarking. 102 references, 33 figures, 51 tables.
Kaminski, George A.; Ponomarev, Sergei Y.; Liu, Aibing B.
2009-01-01
We are presenting POSSIM (POlarizable Simulations with Second order Interaction Model) – a software package and a set of parameters designed for molecular simulations. The key feature of POSSIM is that the electrostatic polarization is taken into account using a previously introduced fast formalism. This permits cutting computational cost of using the explicit polarization by about an order of magnitude. In this article, parameters for water, methane, ethane, propane, butane, methanol and NMA are introduced. These molecules are viewed as model systems for protein simulations. We have achieved our goal of ca. 0.5 kcal/mol accuracy for gas-phase dimerization energies and no more than 2% deviations in liquid state heats of vaporization and densities. Moreover, free energies of hydration of the polarizable methane, ethane and methanol have been calculated using the statistical perturbation theory. These calculations are a model for calculating protein pKa shifts and ligand binding affinities. The free energies of hydration were found to be 2.12 kcal/mol, 1.80 kcal/mol and −4.95 kcal/mol for methane, ethane and methanol, respectively. The experimentally determined literature values are 1.91 kcal/mol, 1.83 kcal/mol and −5.11 kcal/mol. The POSSIM average error in these absolute free energies of hydration is only about 0.13 kcal/mol. Using the statistical perturbation theory with polarizable force fields is not widespread, and we believe that this work opens road to further development of the POSSIM force field and its applications for obtaining accurate energies in protein-related computer modeling. PMID:20209038
Calculation of Spectral Parameters for Doped/Codoped MWO4 (M = Ba2+/Ca2+) Phosphors
NASA Astrophysics Data System (ADS)
Ambast, A. K.; Sharma, S. K.
2017-08-01
We report the spectral parameters of Dy3+-doped and Sr2+/K+-codoped MWO4 (M = Ba2+/Ca2+) tungstate phosphors synthesized by solid-state reaction route. The structural and optical properties were investigated by x-ray diffraction (XRD) analysis, photoluminescence (PL) measurements, and ultraviolet-visible-near infrared spectroscopy. The XRD results indicate tetragonal structure of the phosphors in space group I4 1 / a. The PL spectra show blue and yellow emission at 489 nm and 577 nm, respectively, on excitation at wavelength of 350 nm. The diffuse reflectance spectra reveal bandgap values for the phosphors in the range from 4.24 eV to 5.7 eV. Judd-Ofelt theory was used to calculate the oscillator strength from the excitation spectra of the phosphors. The intensity parameters ( Ω 2, Ω 4, and Ω 6) were used to calculate many radiative parameters such as the radiative transition probabilities ( A R), radiative lifetime ( τ R), branching ratio ( β R), stimulated emission cross-section [ σ( λ p)], and quantum efficiency ( η) for certain excited states of Dy3+ ion.
The effect of explosion parameters on seismic source wavelet calculation and its characteristics
NASA Astrophysics Data System (ADS)
Yimin, Wang; Gang, Tian; Luyang, Yu
2017-10-01
This paper focuses on the calculation and analysis of the source wavelet produced by explosions in land seismic exploration, in order to reveal the effect of the explosion parameters on the signal features of seismic records. The calculation process consist of three steps, numerical simulation of explosions in rock and soil, plastic-elastic boundary (PEB) pressure curve fitting and application of the spherical source model. Four groups of explosion parameters are considered, including detonation velocity, charge weight, coupling material and geometry coupling. The study shows that the source wavelets of limestone and sandstone lack of energy in the low frequency range, which can be enlarged by applying a high detonation velocity explosive, a large charge weight and water coupling. The main frequency of source wavelet of loess is relatively low, which can be increased by using a low detonation velocity explosive and a small charge weight. The result is consistent with the field observations and can serve as a guide for selecting the explosion parameters.
Statistical Analyses of Femur Parameters for Designing Anatomical Plates.
Wang, Lin; He, Kunjin; Chen, Zhengming
2016-01-01
Femur parameters are key prerequisites for scientifically designing anatomical plates. Meanwhile, individual differences in femurs present a challenge to design well-fitting anatomical plates. Therefore, to design anatomical plates more scientifically, analyses of femur parameters with statistical methods were performed in this study. The specific steps were as follows. First, taking eight anatomical femur parameters as variables, 100 femur samples were classified into three classes with factor analysis and Q-type cluster analysis. Second, based on the mean parameter values of the three classes of femurs, three sizes of average anatomical plates corresponding to the three classes of femurs were designed. Finally, based on Bayes discriminant analysis, a new femur could be assigned to the proper class. Thereafter, the average anatomical plate suitable for that new femur was selected from the three available sizes of plates. Experimental results showed that the classification of femurs was quite reasonable based on the anatomical aspects of the femurs. For instance, three sizes of condylar buttress plates were designed. Meanwhile, 20 new femurs are judged to which classes the femurs belong. Thereafter, suitable condylar buttress plates were determined and selected.
Statistical Analyses of Femur Parameters for Designing Anatomical Plates
2016-01-01
Femur parameters are key prerequisites for scientifically designing anatomical plates. Meanwhile, individual differences in femurs present a challenge to design well-fitting anatomical plates. Therefore, to design anatomical plates more scientifically, analyses of femur parameters with statistical methods were performed in this study. The specific steps were as follows. First, taking eight anatomical femur parameters as variables, 100 femur samples were classified into three classes with factor analysis and Q-type cluster analysis. Second, based on the mean parameter values of the three classes of femurs, three sizes of average anatomical plates corresponding to the three classes of femurs were designed. Finally, based on Bayes discriminant analysis, a new femur could be assigned to the proper class. Thereafter, the average anatomical plate suitable for that new femur was selected from the three available sizes of plates. Experimental results showed that the classification of femurs was quite reasonable based on the anatomical aspects of the femurs. For instance, three sizes of condylar buttress plates were designed. Meanwhile, 20 new femurs are judged to which classes the femurs belong. Thereafter, suitable condylar buttress plates were determined and selected. PMID:28044087
NASA Astrophysics Data System (ADS)
Singh, R.; Verma, H. K.
2013-12-01
This paper presents a teaching-learning-based optimization (TLBO) algorithm to solve parameter identification problems in the designing of digital infinite impulse response (IIR) filter. TLBO based filter modelling is applied to calculate the parameters of unknown plant in simulations. Unlike other heuristic search algorithms, TLBO algorithm is an algorithm-specific parameter-less algorithm. In this paper big bang-big crunch (BB-BC) optimization and PSO algorithms are also applied to filter design for comparison. Unknown filter parameters are considered as a vector to be optimized by these algorithms. MATLAB programming is used for implementation of proposed algorithms. Experimental results show that the TLBO is more accurate to estimate the filter parameters than the BB-BC optimization algorithm and has faster convergence rate when compared to PSO algorithm. TLBO is used where accuracy is more essential than the convergence speed.
Use of field parameters in wind engineering design
Stathopoulos, T. )
1989-05-01
The paper presents a useful compendium of information related to the uncertainty of parameters used in wind engineering design. This information is required for reliability-based wind standards and codes of practice as well as structural design. It is suggested in the paper that for the estimation of the integral scale of turbulence, the correlation integral approach provides data with higher uncertainty in comparison with that obtained through spectral estimation. There are two types of modeling uncertainties described.
Kuster, E.; Moore, R.; Lust, L.; Kemper, P.
1996-12-31
A Method of Moments (MoM) electromagnetic model of percolating conducting films was applied to calculate the effective parameters of the composite formed by conducting inclusions placed within a dispersive magnetic but nondispersive dielectric matrix. The MoM calculations demonstrate a coupling between the magnetic properties of the matrix and the effective composite permittivity and frequency dispersion of the composite. The coupling of permittivity and permeability is observed near the percolation threshold of the composite and for high conductivity inclusions. The prediction agrees with physical expectations since near percolation the conduction correlation length dominates the effective permittivity of the composite and this correlation length is determined by both the permittivity and permeability of the composite.
Calculation of optimal parameters of an NH{sub 3}-CO{sub 2} lidar
Vasil'ev, B I; Mannoun, Oussama
2005-06-30
The basic parameters (range, signal-to-noise ratio, and sensitivity) of a lidar using NH{sub 3} and CO{sub 2} lasers are calculated. The principle of lidar operation is based on the differential absorption recording. Absorption spectra of all known Freons are considered in the spectral range 9-13.5 {mu}m and optimal wavelengths suitable for sensing them are determined. It is shown that the NH{sub 3}-CO{sub 2} lidar can sense Freons at distances up to 10 km at a signal-to-noise ratio exceeding 10. Sensitivities of the lidar for sensing Freon-11 using various lines of the ammonia laser are calculated. It is shown that remote sensing of Freon-11 at concentrations of the order of 5x10{sup -6}% is possible at distances up to 8.5 km. (laser applications and other topics in quantum electronics)
Wooten, E Wrenn
2003-12-01
A general formalism for calculating parameters describing physiological acid-base balance in single compartments is extended to multicompartment systems and demonstrated for the multicompartment example of human whole blood. Expressions for total titratable base, strong ion difference, change in total titratable base, change in strong ion difference, and change in Van Slyke standard bicarbonate are derived, giving calculated values in agreement with experimental data. The equations for multicompartment systems are found to have the same mathematical interrelationships as those for single compartments, and the relationship of the present formalism to the traditional form of the Van Slyke equation is also demonstrated. The multicompartment model brings the strong ion difference theory to the same quantitative level as the base excess method.
Calculation of the wetting parameter from a cluster model in the framework of nanothermodynamics.
García-Morales, V; Cervera, J; Pellicer, J
2003-06-01
The critical wetting parameter omega(c) determines the strength of interfacial fluctuations in critical wetting transitions. In this Brief Report, we calculate omega(c) from considerations on critical liquid clusters inside a vapor phase. The starting point is a cluster model developed by Hill and Chamberlin in the framework of nanothermodynamics [Proc. Natl. Acad. Sci. USA 95, 12779 (1998)]. Our calculations yield results for omega(c) between 0.52 and 1.00, depending on the degrees of freedom considered. The findings are in agreement with previous experimental results and give an idea of the universal dynamical behavior of the clusters when approaching criticality. We suggest that this behavior is a combination of translation and vortex rotational motion (omega(c)=0.84).
NASA Astrophysics Data System (ADS)
Stener, M.; De Alti, G.; Fronzoni, G.; Decleva, P.
1997-10-01
Absolute photoionization cross-section and asymmetry parameter profiles of Be, Mg and Ca have been calculated at TDLDA and LDA level, employing a very accurate B-spline basis set and the modified Sternheimer approach. The van Leeuwen-Baerends (VLB) exchange correlation potential has been used, since its correct asymptotic behaviour is able to support virtual states and to describe core-excited resonances. The results have been compared with other calculations and experiment when available. The autoionization resonances have been successfully fitted with a suitable Fano profile. The Ca 3p → 3d 'giant-resonance' has been properly described, despite of the dramatic screening effects involved in the process. The success of the TDLDA method for describing the cross-section profiles in the present systems which display a wide range of many-body effects, seems to suggest that further efforts to apply the present method to molecules are justified.
Neoclassical calculations for W7-X OP1.1 parameters
NASA Astrophysics Data System (ADS)
Landreman, Matt; Alonso, A.; Beidler, C. D.; Bozhenkov, S.; Dinklage, A.; Fuchert, G.; Geiger, J.; Hirsch, M.; Krämer-Flecken, A.; Langenberg, A.; Maassberg, H.; Mollén, A.; Pablant, N.; Pasch, E.; Satake, S.; Smith, H. M.; Traverso, P.; Turkin, Y.; Valson, P.; Velasco, J. L.; Windisch, T.; Zhang, D.; W7-X Team
2016-10-01
Neoclassical calculations are carried out for W7-X OP1.1 plasmas with the SFINCS code, using experimental profiles of ne, Te, and Ti. An electron root solution is found in the inner part of the plasma, consistent with measurements. Calculations are performed using a variety of assumptions for the plasma's impurity composition. Impurities modestly reduce the bootstrap current, and if a flat Zeff profile is assumed, the impurity particle flux profile resembles the Er profile due to dominance of the associated thermodynamic force. Variations of quantities on flux surfaces computed with SFINCS are also presented. The incompressible-ExB approximation is found to be quite accurate for W7-X parameters.
Algorithms and physical parameters involved in the calculation of model stellar atmospheres
NASA Astrophysics Data System (ADS)
Merlo, D. C.
This contribution summarizes the Doctoral Thesis presented at Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba for the degree of PhD in Astronomy. We analyze some algorithms and physical parameters involved in the calculation of model stellar atmospheres, such as atomic partition functions, functional relations connecting gaseous and electronic pressure, molecular formation, temperature distribution, chemical compositions, Gaunt factors, atomic cross-sections and scattering sources, as well as computational codes for calculating models. Special attention is paid to the integration of hydrostatic equation. We compare our results with those obtained by other authors, finding reasonable agreement. We make efforts on the implementation of methods that modify the originally adopted temperature distribution in the atmosphere, in order to obtain constant energy flux throughout. We find limitations and we correct numerical instabilities. We integrate the transfer equation solving directly the integral equation involving the source function. As a by-product, we calculate updated atomic partition functions of the light elements. Also, we discuss and enumerate carefully selected formulae for the monochromatic absorption and dispersion of some atomic and molecular species. Finally, we obtain a flexible code to calculate model stellar atmospheres.
Obtaining model parameters for real materials from ab-initio calculations: Heisenberg exchange
NASA Astrophysics Data System (ADS)
Korotin, Dmitry; Mazurenko, Vladimir; Anisimov, Vladimir; Streltsov, Sergey
An approach to compute exchange parameters of the Heisenberg model in plane-wave based methods is presented. This calculation scheme is based on the Green's function method and Wannier function projection technique. It was implemented in the framework of the pseudopotential method and tested on such materials as NiO, FeO, Li2MnO3, and KCuF3. The obtained exchange constants are in a good agreement with both the total energy calculations and experimental estimations for NiO and KCuF3. In the case of FeO our calculations explain the pressure dependence of the Néel temperature. Li2MnO3 turns out to be a Slater insulator with antiferromagnetic nearest neighbor exchange defined by the spin splitting. The proposed approach provides a unique way to analyze magnetic interactions, since it allows one to calculate orbital contributions to the total exchange coupling and study the mechanism of the exchange coupling. The work was supported by a grant from the Russian Scientific Foundation (Project No. 14-22-00004).
Structure simulation with calculated NMR parameters - integrating COSMOS into the CCPN framework.
Schneider, Olaf; Fogh, Rasmus H; Sternberg, Ulrich; Klenin, Konstantin; Kondov, Ivan
2012-01-01
The Collaborative Computing Project for NMR (CCPN) has build a software framework consisting of the CCPN data model (with APIs) for NMR related data, the CcpNmr Analysis program and additional tools like CcpNmr FormatConverter. The open architecture allows for the integration of external software to extend the abilities of the CCPN framework with additional calculation methods. Recently, we have carried out the first steps for integrating our software Computer Simulation of Molecular Structures (COSMOS) into the CCPN framework. The COSMOS-NMR force field unites quantum chemical routines for the calculation of molecular properties with a molecular mechanics force field yielding the relative molecular energies. COSMOS-NMR allows introducing NMR parameters as constraints into molecular mechanics calculations. The resulting infrastructure will be made available for the NMR community. As a first application we have tested the evaluation of calculated protein structures using COSMOS-derived 13C Cα and Cβ chemical shifts. In this paper we give an overview of the methodology and a roadmap for future developments and applications.
Peregudov, A.; Andrianova, O.; Raskach, K.; Tsibulya, A.
2012-07-01
A number of recent studies have been devoted to the estimation of errors of reactor calculation parameters by the GRS (Generation Random Sampled) method. This method is based on direct sampling input data resulting in formation of random sets of input parameters which are used for multiple calculations. Once these calculations are performed, statistical processing of the calculation results is carried out to determine the mean value and the variance of each calculation parameter of interest. In our study this method is used for estimation of errors of calculation parameters (K{sub eff}, power density, dose rate) of a perspective sodium-cooled fast reactor. Neutron transport calculations were performed by the nodal diffusion code TRIGEX and Monte Carlo code MMK. (authors)
NASA Astrophysics Data System (ADS)
Sarikaya, Ebru Karakaş; Dereli, Ömer
2017-02-01
To obtain liquid phase molecular structure, conformational analysis of Orotic acid was performed and six conformers were determined. For these conformations, eight possible radicals were modelled by using Density Functional Theory computations with respect to molecular structure. Electron Paramagnetic Resonance parameters of these model radicals were calculated and then they were compared with the experimental ones. Geometry optimizations of the molecule and modeled radicals were performed using Becke's three-parameter hybrid-exchange functional combined with the Lee-Yang-Parr correlation functional of Density Functional Theory and 6-311++G(d,p) basis sets in p-dioxane solution. Because Orotic acid can be mutagenic in mammalian somatic cells and it is also mutagenic for bacteria and yeast, it has been studied.
Improvement of plant parameters of the ROBO gamma irradiation facility due to design modification
NASA Astrophysics Data System (ADS)
Kovacs, A.; Moussa, A.; Othman, I.; Del Valle Odar, C.; Seminario, A.; Linares, M.; Huamanlazo, P.; Aymar, J.; Chu, R.
1998-06-01
Two industrial scale, "ROBO" type 60Co gamma irradiation facilities have recently been put into operation in Syria and Peru, and the dosimetry commissioning of both plants have been carried out to determine dose distribution within products and to calculate plant parameters such as efficiency, dose uniformity ratio and throughput. There are some design modifications between the two plants in connection with the location of the carriers with respect to the source plaque and also to each other. The effect of these construction modifications on the plant parameters is discussed in the analysis of the dose distribution data measured in the carriers with depth and height among the four irradiation rows on both sides of the source plaque. The plant parameters were also calculated for different product densities using the technical data of the facilities, and the calculated and measured results were compared to each other.
Microscopic calculation of interacting boson model parameters by potential-energy surface mapping
Bentley, I.; Frauendorf, S.
2011-06-15
A coherent state technique is used to generate an interacting boson model (IBM) Hamiltonian energy surface which is adjusted to match a mean-field energy surface. This technique allows the calculation of IBM Hamiltonian parameters, prediction of properties of low-lying collective states, as well as the generation of probability distributions of various shapes in the ground state of transitional nuclei, the last two of which are of astrophysical interest. The results for krypton, molybdenum, palladium, cadmium, gadolinium, dysprosium, and erbium nuclei are compared with experiment.
NASA Astrophysics Data System (ADS)
Buchachenko, A. L.; Shchegoleva, L. N.; Breslavskaya, N. N.
2009-11-01
Magnetic parameters ( g-factors, hyperfine coupling constants a( 25Mg) and a( 31P)) of paramagnetic pyrophosphate and hydrate magnesium complexes, which model those in catalytic site of the ATP synthesizing enzymes, are calculated. Both g-factors and HFС constants a( 31P) of the paramagnetic pyrophosphate magnesium complexes are identical to those of the pyrophosphate radical. It demonstrates that namely terminal PO 3 group of the liganded ADP in the complex Mg 2+(ADP) 3- donates electron to the Mg(HO)n2+ ion in the primary reaction of the ion-radical mechanism of enzymatic ATP synthesis.
Mayaud, Louis; Lejaille, Michèle; Prigent, Hélène; Louis, Bruno; Fauroux, Brigitte; Lofaso, Frédéric
2014-02-01
We have developed a software that automatically calculates respiratory effort indices, including intrinsic end expiratory pressure (PEEPi) and esophageal pressure-time product (PTPeso). The software first identifies respiratory periods. Clean signals are averaged to provide a reference mean cycle from which respiratory parameters are extracted. The onset of the inspiratory effort is detected automatically by looking backward from the onset of inspiratory flow to the first point where the esophageal pressure derivative is equal to zero (inflection point). PEEPi is derived from this point. Twenty-three recordings from 16 patients were analyzed with the algorithm and compared with experts' manual analysis of signals: 15 recordings were performed during spontaneous breathing, 1 during non-invasive mechanical ventilation, and 7 under both conditions. For all values, the coefficients of determinations (r(2)) exceeded 0.94 (p<0.001). The bias (mean difference) between PEEPi calculated by hand and automatically was -0.26±0.52cmH2O during spontaneous breathing and the precisions (standard deviations of the differences) was 0.52cmH2O with limits of agreement of 0.78 and -1.30cmH2O. The mean difference between PTPeso calculated by hand and automatically was -0.38±1.42cmH2Os/cycle with limits of agreement of 2.46 and -3.22cmH2Os/cycle. Our program provides a reliable method for the automatic calculation of PEEPi and respiratory effort indices, which may facilitate the use of these variables in clinical practice. The software is open source and can be improved with the development and validation of new respiratory parameters. Copyright © 2013 Elsevier B.V. All rights reserved.
Design of Fiber Optic Sensors for Measuring Hydrodynamic Parameters
NASA Technical Reports Server (NTRS)
Lyons, Donald R.; Quiett, Carramah; Griffin, DeVon (Technical Monitor)
2001-01-01
The science of optical hydrodynamics involves relating the optical properties to the fluid dynamic properties of a hydrodynamic system. Fiber-optic sensors are being designed for measuring the hydrodynamic parameters of various systems. As a flowing fluid makes an encounter with a flat surface, it forms a boundary layer near this surface. The region between the boundary layer and the flat plate contains information about parameters such as viscosity, compressibility, pressure, density, and velocity. An analytical model has been developed for examining the hydrodynamic parameters near the surface of a fiber-optic sensor. An analysis of the conservation of momentum, the continuity equation and the Navier-Stokes equation for compressible flow were used to develop expressions for the velocity and the density as a function of the distance along the flow and above the surface. When examining the flow near the surface, these expressions are used to estimate the sensitivity required to perform direct optical measurements and to derive the shear force for indirect optical measurements. The derivation of this result permits the incorporation of better design parameters for other fiber-based sensors. Future work includes analyzing the optical parametric designs of fiber-optic sensors, modeling sensors to utilize the parameters for hydrodynamics and applying different mixtures of hydrodynamic flow. Finally, the fabrication of fiber-optic sensors for hydrodynamic flow applications of the type described in this presentation could enhance aerospace, submarine, and medical technology.
Inertial sensor-based stride parameter calculation from gait sequences in geriatric patients.
Rampp, Alexander; Barth, Jens; Schülein, Samuel; Gaßmann, Karl-Günter; Klucken, Jochen; Eskofier, Björn M
2015-04-01
A detailed and quantitative gait analysis can provide evidence of various gait impairments in elderly people. To provide an objective decision-making basis for gait analysis, simple applicable tests analyzing a high number of strides are required. A mobile gait analysis system, which is mounted on shoes, can fulfill these requirements. This paper presents a method for computing clinically relevant temporal and spatial gait parameters. Therefore, an accelerometer and a gyroscope were positioned laterally below each ankle joint. Temporal gait events were detected by searching for characteristic features in the signals. To calculate stride length, the gravity compensated accelerometer signal was double integrated, and sensor drift was modeled using a piece-wise defined linear function. The presented method was validated using GAITRite-based gait parameters from 101 patients (average age 82.1 years). Subjects performed a normal walking test with and without a wheeled walker. The parameters stride length and stride time showed a correlation of 0.93 and 0.95 between both systems. The absolute error of stride length was 6.26 cm on normal walking test. The developed system as well as the GAITRite showed an increased stride length, when using a four-wheeled walker as walking aid. However, the walking aid interfered with the automated analysis of the GAITRite system, but not with the inertial sensor-based approach. In summary, an algorithm for the calculation of clinically relevant gait parameters derived from inertial sensors is applicable in the diagnostic workup and also during long-term monitoring approaches in the elderly population.
Effect of buoyancy and power design parameters on hybrid airship performance
NASA Technical Reports Server (NTRS)
Talbot, P. D.; Gelhausen, P. A.
1983-01-01
The effects of several design parameters on the performance of hybrid airships having rotors and propellers were examined with a simple mathematical model. The parameters included buoyancy ratio, Froude number, ratio of rotor power to total power, and rotor shaft tilt. Performance variations resulting from changes in these parameters were calculated, and are presented and discussed. Performance quantities included best climb rate, equivalent vehicle L/D, and maximum speed. Performance at all speeds between hover and maximum speed was found to be sensitive to power distribution between rotors and propellers, and to rotor shaft tilt.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Basic Parameters for the Calculation of Emission Factors for Lime Production S Table S-1 to Subpart S of Part 98 Protection of Environment... Manufacturing Pt. 98, Subpt. S, Table S-1 Table S-1 to Subpart S of Part 98—Basic Parameters for the Calculation...
Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Basic Parameters for the Calculation of Emission Factors for Lime Production S Table S-1 to Subpart S of Part 98 Protection of Environment... Manufacturing Pt. 98, Subpt. S, Table S-1 Table S-1 to Subpart S of Part 98—Basic Parameters for the Calculation...
Code of Federal Regulations, 2013 CFR
2013-07-01
... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Basic Parameters for the Calculation of Emission Factors for Lime Production S Table S-1 to Subpart S of Part 98 Protection of Environment... Manufacturing Pt. 98, Subpt. S, Table S-1 Table S-1 to Subpart S of Part 98—Basic Parameters for the Calculation...
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Basic Parameters for the Calculation of Emission Factors for Lime Production S Table S-1 to Subpart S of Part 98 Protection of Environment... Manufacturing Pt. 98, Subpt. S, Table S-1 Table S-1 to Subpart S of Part 98—Basic Parameters for the Calculation...
Parameter Scaling and Practical Design of TME Lattice
Jiao, Yi; Cai, Yunhai; Chao, Alex; /SLAC /Beijing, Inst. High Energy Phys. /SLAC
2011-11-08
It is a challenge to produce a practical design of an electron storage ring with a theorectical minimum emittance (TME) lattice of ultra low emittance, e.g. several pico-meters, due to the very strong focusing and extremely large natural chromaticity associated to these lattice designs. To help dealing with this challenge, it is requisite to scale the parameters and look for a best solution. In this paper, the parameter scaling is summarized, and it is argued that, with the lattice configuration with defocusing quadrupole closer to the dipole or just defocusing dipole, one can reach a good balance of the low emittance and relative small natural chromaticity, with phase advance per half cell below {pi}/2. The 10 pm TME lattice for PEP-X is shown at last as demonstration of the design procedure.
Parameter Screening and Optimisation for ILP Using Designed Experiments
NASA Astrophysics Data System (ADS)
Srinivasan, Ashwin; Ramakrishnan, Ganesh
Reports of experiments conducted with an Inductive Logic Programming system rarely describe how specific values of parameters of the system are arrived at when constructing models. Usually, no attempt is made to identify sensitive parameters, and those that are used are often given "factory-supplied" default values, or values obtained from some non-systematic exploratory analysis. The immediate consequence of this is, of course, that it is not clear if better models could have been obtained if some form of parameter selection and optimisation had been performed. Questions follow inevitably on the experiments themselves: specifically, are all algorithms being treated fairly, and is the exploratory phase sufficiently well-defined to allow the experiments to be replicated? In this paper, we investigate the use of parameter selection and optimisation techniques grouped under the study of experimental design. Screening and "response surface" methods determine, in turn, sensitive parameters and good values for these parameters. This combined use of parameter selection and response surface-driven optimisation has a long history of application in industrial engineering, and its role in ILP is investigated using two well-known benchmarks. The results suggest that computational overheads from this preliminary phase are not substantial, and that much can be gained, both on improving system performance and on enabling controlled experimentation, by adopting well-established procedures such as the ones proposed here.
Robust integrated autopilot/autothrottle design using constrained parameter optimization
NASA Technical Reports Server (NTRS)
Ly, Uy-Loi; Voth, Christopher; Sanjay, Swamy
1990-01-01
A multivariable control design method based on constrained parameter optimization was applied to the design of a multiloop aircraft flight control system. Specifically, the design method is applied to the following: (1) direct synthesis of a multivariable 'inner-loop' feedback control system based on total energy control principles; (2) synthesis of speed/altitude-hold designs as 'outer-loop' feedback/feedforward control systems around the above inner loop; and (3) direct synthesis of a combined 'inner-loop' and 'outer-loop' multivariable control system. The design procedure offers a direct and structured approach for the determination of a set of controller gains that meet design specifications in closed-loop stability, command tracking performance, disturbance rejection, and limits on control activities. The presented approach may be applied to a broader class of multiloop flight control systems. Direct tradeoffs between many real design goals are rendered systematic by this method following careful problem formulation of the design objectives and constraints. Performance characteristics of the optimization design were improved over the current autopilot design on the B737-100 Transport Research Vehicle (TSRV) at the landing approach and cruise flight conditions; particularly in the areas of closed-loop damping, command responses, and control activity in the presence of turbulence.
NASA Astrophysics Data System (ADS)
Dementyeva, Svetlana; Ilin, Nikolay; Shatalina, Maria; Mareev, Evgeny
2016-04-01
Now-casting and long-term forecasting of lightning flashes occurrence are urgent problems from different points of view. There are several approaches to predicting lightning activity using indirect non-electrical parameters based on the relationship of lightning flashes with vertical fluxes of solid-phased hydrometeors but for more explicit forecasting of the lightning flashes occurrence electric processes should be considered. In addition, a factor playing a key role for now-casting of lightning activity is the earliness. We have proposed an algorithm, which makes the process of thunderstorms prediction automatic (due to automatic start of the electric parameters calculation) and quick (due to the use of simplified methods). Our forecasting was based on the use of Weather Research and Forecasting (WRF) model, which does not include the electrification processes, but it was supplemented with two modules. The first is an algorithm, which allows us to select thunderstorm events indirectly. It is based on such characteristics of thunderclouds and thunderstorms as radar reflectivity, duration and area and provides us with information about an approximate beginning and duration of the thunderstorm. The second module is a method for electric parameters calculations, which we have proposed before. It was suggested that the non-inductive mechanism of charge generation and separation plays a key role in the thundercloud electrification processes. Also charge densities of solid-phased hydrometeors are assumed to be proportional to their mass in elementary air volume. According to the models by Saunders and Takahashi, particles change the sign of charge while getting into the lower part of thundercloud from the upper and vice versa. Electric neutrality in the vertical air column was supposed in the course of vertical charge separation due to collisions between falling graupels and carried upward ice crystals. Electric potential (and consequently electric field) can be found
Calculating wave-generated bottom orbital velocities from surface-wave parameters
Wiberg, P.L.; Sherwood, C.R.
2008-01-01
Near-bed wave orbital velocities and shear stresses are important parameters in many sediment-transport and hydrodynamic models of the coastal ocean, estuaries, and lakes. Simple methods for estimating bottom orbital velocities from surface-wave statistics such as significant wave height and peak period often are inaccurate except in very shallow water. This paper briefly reviews approaches for estimating wave-generated bottom orbital velocities from near-bed velocity data, surface-wave spectra, and surface-wave parameters; MATLAB code for each approach is provided. Aspects of this problem have been discussed elsewhere. We add to this work by providing a method for using a general form of the parametric surface-wave spectrum to estimate bottom orbital velocity from significant wave height and peak period, investigating effects of spectral shape on bottom orbital velocity, comparing methods for calculating bottom orbital velocity against values determined from near-bed velocity measurements at two sites on the US east and west coasts, and considering the optimal representation of bottom orbital velocity for calculations of near-bed processes. Bottom orbital velocities calculated using near-bed velocity data, measured wave spectra, and parametric spectra for a site on the northern California shelf and one in the mid-Atlantic Bight compare quite well and are relatively insensitive to spectral shape except when bimodal waves are present with maximum energy at the higher-frequency peak. These conditions, which are most likely to occur at times when bottom orbital velocities are small, can be identified with our method as cases where the measured wave statistics are inconsistent with Donelan's modified form of the Joint North Sea Wave Project (JONSWAP) spectrum. We define the 'effective' forcing for wave-driven, near-bed processes as the product of the magnitude of forcing times its probability of occurrence, and conclude that different bottom orbital velocity statistics
Parameter design considerations for an oscillator IR-FEL
NASA Astrophysics Data System (ADS)
Jia, Qi-Ka
2017-01-01
An infrared oscillator FEL user facility will be built at the National Synchrotron Radiation Laboratory at in Hefei, China. In this paper, the parameter design of the oscillator FEL is discussed, and some original relevant approaches and expressions are presented. Analytic formulae are used to estimate the optical field gain and saturation power for the preliminary design. By considering both physical and technical constraints, the relation of the deflection parameter K to the undulator period is analyzed. This helps us to determine the ranges of the magnetic pole gap, the electron energy and the radiation wavelength. The relations and design of the optical resonator parameters are analyzed. Using dimensionless quantities, the interdependences between the radii of curvature of the resonator mirror and the various parameters of the optical resonator are clearly demonstrated. The effect of the parallel-plate waveguide is analyzed for the far-infrared oscillator FEL. The condition of the necessity of using a waveguide and the modified filling factor in the case of the waveguide are given, respectively. Supported by National Nature Science Foundation of China (21327901, 11375199)
NASA Astrophysics Data System (ADS)
Schmidt, L.-P.; Menzel, W.
Mechanical accuracy requirements for waveguide components become more exacting in connection with the use of such components for operation in the millimeter-wave region. Changes in a circuit make it often necessary to construct a new waveguide component. For these reasons, investigations are being conducted with the objective to design millimeter-wave circuits which employ new types of line structures. A number of such structures is considered, taking into account the image guide, the inverted strip image guide, the trapped image guide, the groove guide, the H-guide, the comb guide, the unilateral fin-line, the bilateral fin-line, the antipodal fin-line, the coplanar fin-line, the microstrip line, and the bilateral suspended substrate line. The calculation of the phase coefficients for the waveguides is discussed, giving attention to the use of the equivalent transmission line concept reported by Itoh (1980). The calculation of the line impedance is also considered, and numerical results are presented.
Fellinger, Michael R.; Hector, Louis G.; Trinkle, Dallas R.
2016-10-28
Here, we present an efficient methodology for computing solute-induced changes in lattice parameters and elastic stiffness coefficients Cij of single crystals using density functional theory. We also introduce a solute strain misfit tensor that quantifies how solutes change lattice parameters due to the stress they induce in the host crystal. Solutes modify the elastic stiffness coefficients through volumetric changes and by altering chemical bonds. We compute each of these contributions to the elastic stiffness coefficients separately, and verify that their sum agrees with changes in the elastic stiffness coefficients computed directly using fully optimized supercells containing solutes. Computing the two elastic stiffness contributions separately is more computationally efficient and provides more information on solute effects than the direct calculations. We compute the solute dependence of polycrystalline averaged shear and Young's moduli from the solute dependence of the single-crystal Cij. We then apply this methodology to substitutional Al, B, Cu, Mn, Si solutes and octahedral interstitial C and N solutes in bcc Fe. Comparison with experimental data indicates that our approach accurately predicts solute-induced changes in the lattice parameter and elastic coefficients. The computed data can be used to quantify solute-induced changes in mechanical properties such as strength and ductility, and can be incorporated into mesoscale models to improve their predictive capabilities.
Fellinger, Michael R.; Hector, Louis G.; Trinkle, Dallas R.
2016-10-28
Here, we present an efficient methodology for computing solute-induced changes in lattice parameters and elastic stiffness coefficients Cij of single crystals using density functional theory. We also introduce a solute strain misfit tensor that quantifies how solutes change lattice parameters due to the stress they induce in the host crystal. Solutes modify the elastic stiffness coefficients through volumetric changes and by altering chemical bonds. We compute each of these contributions to the elastic stiffness coefficients separately, and verify that their sum agrees with changes in the elastic stiffness coefficients computed directly using fully optimized supercells containing solutes. Computing the twomore » elastic stiffness contributions separately is more computationally efficient and provides more information on solute effects than the direct calculations. We compute the solute dependence of polycrystalline averaged shear and Young's moduli from the solute dependence of the single-crystal Cij. We then apply this methodology to substitutional Al, B, Cu, Mn, Si solutes and octahedral interstitial C and N solutes in bcc Fe. Comparison with experimental data indicates that our approach accurately predicts solute-induced changes in the lattice parameter and elastic coefficients. The computed data can be used to quantify solute-induced changes in mechanical properties such as strength and ductility, and can be incorporated into mesoscale models to improve their predictive capabilities.« less
Considerations for design parameters for a dedicated medical accelerator
Alonso, J.R.
1980-10-01
There are only a very few critical parameters which determine the size, performance and cost of a heavy ion accelerator. These are the mass of the heaviest ion desired, the maximum range of this heaviest ion in tissue, and the highest intensity desired. Other parameters, such as beam emittance, beam delivery flexibility, reliability and experimental facility configurations are important, but are not primary driving factors in the design effort. The various clinical applications for a heavy ion accelerator are evaluated, detailing the most desirable beams for each application.
Designing of discrete mechatronic vibrating systems with negative value parameters
NASA Astrophysics Data System (ADS)
Buchacz, Andrzej; Gałęziowski, Damian
2016-10-01
In the paper, the known problem of vibration control, authors expanded for designing of mechatronic discrete systems that contains single or multiply piezoelectric elements connected to external electric networks. Main focus has been given for investigations in relation to damping performance and parameters study, in case of potential practical application. By different configurations of considered mechatronic discrete branched structures with two degrees of freedom, key negative parameters have been identified and investigated in case of vibration control effectiveness. Results have been presented in graphical form of amplitudes and dynamical flexibility functions.
NASA Astrophysics Data System (ADS)
Tokunaga, Yoshitaka
This paper presents estimation techniques of machine parameters for power transformer using design procedure of transformer and genetic algorithm with real coding. Especially, it is very difficult to obtain machine parameters for transformers in customers' facilities. Using estimation techniques, machine parameters could be calculated from the only nameplate data of these transformers. Subsequently, EMTP-ATP simulation of the inrush current was carried out using machine parameters estimated by techniques developed in this study and simulation results were reproduced measured waveforms.
Analysis of Design Parameters Effects on Vibration Characteristics of Fluidlastic Isolators
NASA Astrophysics Data System (ADS)
Deng, Jing-hui; Cheng, Qi-you
2017-07-01
The control of vibration in helicopters which consists of reducing vibration levels below the acceptable limit is one of the key problems. The fluidlastic isolators become more and more widely used because the fluids are non-toxic, non-corrosive, nonflammable, and compatible with most elastomers and adhesives. In the field of the fluidlastic isolators design, the selection of design parameters is very important to obtain efficient vibration-suppressed. Aiming at getting the effect of design parameters on the property of fluidlastic isolator, a dynamic equation is set up based on the theory of dynamics. And the dynamic analysis is carried out. The influences of design parameters on the property of fluidlastic isolator are calculated. Dynamic analysis results have shown that fluidlastic isolator can reduce the vibration effectively. Analysis results also showed that the design parameters such as the fluid density, viscosity coefficient, stiffness (K1 and K2) and loss coefficient have obvious influence on the performance of isolator. The efficient vibration-suppressed can be obtained by the design optimization of parameters.
Calculation of PID controller parameters by using a fuzzy neural network.
Lee, Ching-Hung; Teng, Ching-Cheng
2003-07-01
In this paper, we use the fuzzy neural network (FNN) to develop a formula for designing the proportional-integral-derivative (PID) controller. This PID controller satisfies the criteria of minimum integrated absolute error (IAE) and maximum of sensitivity (Ms). The FNN system is used to identify the relationship between plant model and controller parameters based on IAE and Ms. To derive the tuning rule, the dominant pole assignment method is applied to simplify our optimization processes. Therefore, the FNN system is used to automatically tune the PID controller for different system parameters so that neither theoretical methods nor numerical methods need be used. Moreover, the FNN-based formula can modify the controller to meet our specification when the system model changes. A simulation result for applying to the motor position control problem is given to demonstrate the effectiveness of our approach.
NASA Astrophysics Data System (ADS)
Zhang, Hongtao; Yin, FuChang; Shi, Jiangtian
2002-09-01
The model of laser communication system using in vehicle mobile target was built. Optimal design and calculation was analyzed for system performance, such as laser transmission, photoelectric reception and speech information processing and image stabilization. Algorithm of MELP (Mixed Excitation Line Predication) compressed speech scrambling was received in processing voice message, which reached 2.4 kbps digital speech code stream, and realized digitization of laser communication. It was also analyzed carefully about the principle theory of MELP algorithm encoding and decoding as well as algorithm realization used in DSP. Image stabilization and tracking were realized by process signal errors which acquired at quadrant error sensors.
NASA Astrophysics Data System (ADS)
Hsu, Wei-Ting; Loh, Chin-Hsiung; Chao, Shu-Hsien
2015-03-01
Stochastic subspace identification method (SSI) has been proven to be an efficient algorithm for the identification of liner-time-invariant system using multivariate measurements. Generally, the estimated modal parameters through SSI may be afflicted with statistical uncertainty, e.g. undefined measurement noises, non-stationary excitation, finite number of data samples etc. Therefore, the identified results are subjected to variance errors. Accordingly, the concept of the stabilization diagram can help users to identify the correct model, i.e. through removing the spurious modes. Modal parameters are estimated at successive model orders where the physical modes of the system are extracted and separated from the spurious modes. Besides, an uncertainty computation scheme was derived for the calculation of uncertainty bounds for modal parameters at some given model order. The uncertainty bounds of damping ratios are particularly interesting, as the estimation of damping ratios are difficult to obtain. In this paper, an automated stochastic subspace identification algorithm is addressed. First, the identification of modal parameters through covariance-driven stochastic subspace identification from the output-only measurements is used for discussion. A systematic way of investigation on the criteria for the stabilization diagram is presented. Secondly, an automated algorithm of post-processing on stabilization diagram is demonstrated. Finally, the computation of uncertainty bounds for each mode with all model order in the stabilization diagram is utilized to determine system natural frequencies and damping ratios. Demonstration of this study on the system identification of a three-span steel bridge under operation condition is presented. It is shown that the proposed new operation procedure for the automated covariance-driven stochastic subspace identification can enhance the robustness and reliability in structural health monitoring.
NASA Technical Reports Server (NTRS)
Koenig, R. W.; Fishbach, L. H.
1972-01-01
A computer program entitled GENENG employs component performance maps to perform analytical, steady state, engine cycle calculations. Through a scaling procedure, each of the component maps can be used to represent a family of maps (different design values of pressure ratios, efficiency, weight flow, etc.) Either convergent or convergent-divergent nozzles may be used. Included is a complete FORTRAN 4 listing of the program. Sample results and input explanations are shown for one-spool and two-spool turbojets and two-spool separate- and mixed-flow turbofans operating at design and off-design conditions.
NASA Astrophysics Data System (ADS)
Ben Mosbah, Abdallah
In order to improve the qualities of wind tunnel tests, and the tools used to perform aerodynamic tests on aircraft wings in the wind tunnel, new methodologies were developed and tested on rigid and flexible wings models. A flexible wing concept is consists in replacing a portion (lower and/or upper) of the skin with another flexible portion whose shape can be changed using an actuation system installed inside of the wing. The main purpose of this concept is to improve the aerodynamic performance of the aircraft, and especially to reduce the fuel consumption of the airplane. Numerical and experimental analyses were conducted to develop and test the methodologies proposed in this thesis. To control the flow inside the test sections of the Price-Paidoussis wind tunnel of LARCASE, numerical and experimental analyses were performed. Computational fluid dynamics calculations have been made in order to obtain a database used to develop a new hybrid methodology for wind tunnel calibration. This approach allows controlling the flow in the test section of the Price-Paidoussis wind tunnel. For the fast determination of aerodynamic parameters, new hybrid methodologies were proposed. These methodologies were used to control flight parameters by the calculation of the drag, lift and pitching moment coefficients and by the calculation of the pressure distribution around an airfoil. These aerodynamic coefficients were calculated from the known airflow conditions such as angles of attack, the mach and the Reynolds numbers. In order to modify the shape of the wing skin, electric actuators were installed inside the wing to get the desired shape. These deformations provide optimal profiles according to different flight conditions in order to reduce the fuel consumption. A controller based on neural networks was implemented to obtain desired displacement actuators. A metaheuristic algorithm was used in hybridization with neural networks, and support vector machine approaches and their
Consideration of Design Parameters of Ultrasonic Transducer for Fruit
NASA Astrophysics Data System (ADS)
Kim, K. B.; Kim, M. S.; Lee, S. D.; Choi, M. Y.
2005-04-01
This study was conducted to develop the ultrasonic transducers for non-destructive contact measurement of fruits. The design parameters for ultrasonic transducer such as acoustical impedance of fruits, kinds of piezoelectric materials, ultrasonic wave frequency, and transducer diameter were investigated. In order to match the impedance between piezoelectric material and fruit, various materials were evaluated. And to control the bandwidth of ultrasonic wave of the transducer, various backing materials were fabricated and evaluated. Especially, the wear plate of the transducer was designed and fabricated considering curvature of fruit. Finally, the ultrasonic transducer having 100 kHz of central frequency were fabricated and tested.
Robust parameter design for automatically controlled systems and nanostructure synthesis
NASA Astrophysics Data System (ADS)
Dasgupta, Tirthankar
2007-12-01
This research focuses on developing comprehensive frameworks for developing robust parameter design methodology for dynamic systems with automatic control and for synthesis of nanostructures. In many automatically controlled dynamic processes, the optimal feedback control law depends on the parameter design solution and vice versa and therefore an integrated approach is necessary. A parameter design methodology in the presence of feedback control is developed for processes of long duration under the assumption that experimental noise factors are uncorrelated over time. Systems that follow a pure-gain dynamic model are considered and the best proportional-integral and minimum mean squared error control strategies are developed by using robust parameter design. The proposed method is illustrated using a simulated example and a case study in a urea packing plant. This idea is also extended to cases with on-line noise factors. The possibility of integrating feedforward control with a minimum mean squared error feedback control scheme is explored. To meet the needs of large scale synthesis of nanostructures, it is critical to systematically find experimental conditions under which the desired nanostructures are synthesized reproducibly, at large quantity and with controlled morphology. The first part of the research in this area focuses on modeling and optimization of existing experimental data. Through a rigorous statistical analysis of experimental data, models linking the probabilities of obtaining specific morphologies to the process variables are developed. A new iterative algorithm for fitting a Multinomial GLM is proposed and used. The optimum process conditions, which maximize the above probabilities and make the synthesis process less sensitive to variations of process variables around set values, are derived from the fitted models using Monte-Carlo simulations. The second part of the research deals with development of an experimental design methodology, tailor
NASA Astrophysics Data System (ADS)
Yong, Kilyuk; Jo, Sujang; Bang, Hyochoong
This paper presents a modified Rodrigues parameter (MRP)-based nonlinear observer design to estimate bias, scale factor and misalignment of gyroscope measurements. A Lyapunov stability analysis is carried out for the nonlinear observer. Simulation is performed and results are presented illustrating the performance of the proposed nonlinear observer under the condition of persistent excitation maneuver. In addition, a comparison between the nonlinear observer and alignment Kalman filter (AKF) is made to highlight favorable features of the nonlinear observer.
Optimizing Hyperspectral Imagery Anomaly Detection through Robust Parameter Design
2011-10-01
THROUGH ROBUST PARAMETER DESIGN DISSERTATION Presented to the Faculty Graduate School of Engineering and Management Air Force Institute of Technology...Air University Air Education and Training Command in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Francis M. Mindrup...Graduate School of Engineering and Management For my loving wife, daughter and sons iv AFIT/DS/ENS/11-04 Abstract Advances in sensor technology
NASA Technical Reports Server (NTRS)
Young, G.
1982-01-01
A design methodology capable of dealing with nonlinear systems, such as a controlled ecological life support system (CELSS), containing parameter uncertainty is discussed. The methodology was applied to the design of discrete time nonlinear controllers. The nonlinear controllers can be used to control either linear or nonlinear systems. Several controller strategies are presented to illustrate the design procedure.
Morgan, Nicole Y.; Kramer-Marek, Gabriela; Smith, Paul D.; Camphausen, Kevin; Capala, Jacek
2011-01-01
The recent demonstration of nanoscale scintillators has led to interest in the combination of radiation and photodynamic therapy. In this model, scintillating nanoparticles conjugated to photosensitizers and molecular targeting agents would enhance the targeting and improve the efficacy of radiotherapy and extend the application of photodynamic therapy to deeply seated tumors. In this study, we calculated the physical parameters required for these nanoparticle conjugates to deliver cytotoxic levels of singlet oxygen at therapeutic radiation doses, drawing on the published literature from several disparate fields. Although uncertainties remain, it appears that the light yield of the nanoscintillators, the efficiency of energy transfer to the photosensitizers, and the cellular uptake of the nano-particles all need to be fairly well optimized to observe a cytotoxic effect. Even so, the efficacy of the combination therapy will likely be restricted to X-ray energies below 300 keV, which limits the application to brachytherapy. PMID:19267550
[Calculation of spectroscopic parameters of highly doped Er3+ in lithium niobate].
Sun, Dun-lu; Zhang, Qing-li; Wang, Ai-hua; Hang, Yin; Zhang, Lian-han; Qian, Xiao-bo; Zhu, Shi-ning; Yin, Shao-tang
2005-09-01
A highly doped Er3+: LiNbO3 (concentration 6 mol%) crystal was grown successfully by Czochralski method. The crystal is higher than that of the lowly doped Er3+ in LiNbO3 crystal, which is helpful to improve absorption coefficient of the grown the pumping efficiency. The absorption spectra at two unpolarized directions (X and Z) and two polarized directions (E parallel Z, E perpendicular Z) were measured. Using the Judd-Ofelt theory, and according to the measured absorption spectra, the intensity parameters omegalambda of Er3+ were fitted. The results of root-mean square (r. m. s) deviation show that the error of polarized fitting is less than that of unpolarized one. Thus fluorescence transition probabilities (Ajj), radioactive lifetime (tau), fluorescence branching ratio (beta), and integrated emission cross section (sigmap) were calculated and accepted according to the polarized results, and were also discussed and compared with the ones reported in the literature.
Ab initio calculation of the Gilbert damping parameter via the linear response formalism.
Ebert, H; Mankovsky, S; Ködderitzsch, D; Kelly, P J
2011-08-05
A Kubo-Greenwood-like equation for the Gilbert damping parameter α is presented that is based on the linear response formalism. Its implementation using the fully relativistic Korringa-Kohn-Rostoker band structure method in combination with coherent potential approximation alloy theory allows it to be applied to a wide range of situations. This is demonstrated with results obtained for the bcc alloy system Fe(1-x)Co(x) as well as for a series of alloys of Permalloy with 5d transition metals. To account for the thermal displacements of atoms as a scattering mechanism, an alloy-analogy model is introduced. The corresponding calculations for Ni correctly describe the rapid change of α when small amounts of substitutional Cu are introduced.
Laurent, M
1980-01-01
Currently used hemodynamic and oxygen transport formulas are reviewed in order to chose the shortest form compatible with an optimal clinical accuracy. Programming of hand held calculators with these selected equations spares steps available in the program memory. (Acta anaesth. belg., 1980, 31, 45-52).
NASA Astrophysics Data System (ADS)
Avram, C. N.; Gruia, A. S.; Brik, M. G.; Barb, A. M.
2015-12-01
Calculations of the Cr3+ energy levels, spin-Hamiltonian parameters and vibrational spectra for the layered CrCl3 crystals are reported for the first time. The crystal field parameters and the energy level scheme were calculated in the framework of the Exchange Charge Model of crystal field. The spin-Hamiltonian parameters (zero-field splitting parameter D and g-factors) for Cr3+ ion in CrCl3 crystals were obtained using two independent techniques: i) semi-empirical crystal field theory and ii) density functional theory (DFT)-based model. In the first approach, the spin-Hamiltonian parameters were calculated from the perturbation theory method and the complete diagonalization (of energy matrix) method. The infrared (IR) and Raman frequencies were calculated for both experimental and fully optimized geometry of the crystal structure, using CRYSTAL09 software. The obtained results are discussed and compared with the experimental available data.
Lino, Jéssica B R; Rocha, Eduardo P; Ramalho, Teodorico C
2017-06-15
Quantum computing is the field of science that uses quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. The fundamental information unit used in quantum computing is the quantum bit or qubit. It is well-known that quantum computers could theoretically be able to solve problems much more quickly than any classical computers. Currently, the first and still the most successful implementations of quantum information processing (QIP) have been based on nuclear spins in liquids. However, molecules that enable many qubits NMR QIP implementations should meet some conditions: have large chemical shifts and be appropriately dispersed for qubit addressability, appreciable spin-spin coupling between any pair of spins, and a long relaxation time. In this line, benzyldene-2,3-dihydro-1H-[1,3]diphosphole (BDF) derivatives have been theoretically tested for maximizing large chemical shifts, spin-spin coupling, and minimizing the hyperfine coupling constant. Thus, the structures were optimized at the B3LYP/6-311G(d,p) level and showed a significant similarity with the experimental geometrical parameters. The NMR spectroscopic parameters (δ and J) were calculated with six different DFT functionals. The τ-HCTH/6-31G(2d) level is in better agreement with the experimental data of (31)P and (13)C chemical shifts, while PCM-B3LYP/cc-pVDZ level shows a decrease on deviation between calculated and experimental values for P-P and P-C SSCC. The surface response technique was employed to rationalize how the hyperfine constant varies with the chemical shifts and coupling constants values. From our findings, BDF-NO2 was the best candidate for NMR quantum computations (NMR-QC) among the studied series.
Launch Vehicle Propulsion Parameter Design Multiple Selection Criteria
NASA Technical Reports Server (NTRS)
Shelton, Joey Dewayne
2004-01-01
The optimization tool described herein addresses and emphasizes the use of computer tools to model a system and focuses on a concept development approach for a liquid hydrogen/liquid oxygen single-stage-to-orbit system, but more particularly the development of the optimized system using new techniques. This methodology uses new and innovative tools to run Monte Carlo simulations, genetic algorithm solvers, and statistical models in order to optimize a design concept. The concept launch vehicle and propulsion system were modeled and optimized to determine the best design for weight and cost by varying design and technology parameters. Uncertainty levels were applied using Monte Carlo Simulations and the model output was compared to the National Aeronautics and Space Administration Space Shuttle Main Engine. Several key conclusions are summarized here for the model results. First, the Gross Liftoff Weight and Dry Weight were 67% higher for the design case for minimization of Design, Development, Test and Evaluation cost when compared to the weights determined by the minimization of Gross Liftoff Weight case. In turn, the Design, Development, Test and Evaluation cost was 53% higher for optimized Gross Liftoff Weight case when compared to the cost determined by case for minimization of Design, Development, Test and Evaluation cost. Therefore, a 53% increase in Design, Development, Test and Evaluation cost results in a 67% reduction in Gross Liftoff Weight. Secondly, the tool outputs define the sensitivity of propulsion parameters, technology and cost factors and how these parameters differ when cost and weight are optimized separately. A key finding was that for a Space Shuttle Main Engine thrust level the oxidizer/fuel ratio of 6.6 resulted in the lowest Gross Liftoff Weight rather than at 5.2 for the maximum specific impulse, demonstrating the relationships between specific impulse, engine weight, tank volume and tank weight. Lastly, the optimum chamber pressure for
Introduction to boundary-layer theory. [viscous friction loss calculation for turbine blade design
NASA Technical Reports Server (NTRS)
Mcnally, W. D.
1973-01-01
The pressure ratio across a turbine provides a certain amount of ideal energy that is available to the turbine for producing work. The portion of the ideal energy that is not converted to work is considered to be a loss. One of the more important and difficult aspects of turbine design is the prediction of the losses. The primary cause of losses is the boundary layer that develops on the blade and end wall surfaces. Boundary-layer theory is used to calculate the parameters needed to estimate viscous (friction) losses.
Introduction to boundary-layer theory. [viscous friction loss calculation for turbine blade design
NASA Technical Reports Server (NTRS)
Mcnally, W. D.
1973-01-01
The pressure ratio across a turbine provides a certain amount of ideal energy that is available to the turbine for producing work. The portion of the ideal energy that is not converted to work is considered to be a loss. One of the more important and difficult aspects of turbine design is the prediction of the losses. The primary cause of losses is the boundary layer that develops on the blade and end wall surfaces. Boundary-layer theory is used to calculate the parameters needed to estimate viscous (friction) losses.
NASA Astrophysics Data System (ADS)
Zhang, Huan; Bo, Tian-Li; Zheng, Xiaojing
2017-03-01
Dusty phenomena, such as wind-blown sand, dust devils, and dust storms, play key roles in Earth's climate and geological processes. Dust electrification considerably affects the lifting and transport of dust particles. However, the electrical properties of dust storms remain poorly understood. Here, we conducted multi-parameter measurements and theoretical calculations to investigate the electrical properties of dust storms and their application to dust storm prediction. The results show that the vertical electric field (E-field) decreases first, then increases, and finally decreases with the height above the ground, reversing its direction at two heights, ∼ 8- 12 and ∼ 24 m. This suggests that the charge polarity of dust particles changes from negative to positive and back to negative again as the height increases. By carefully analyzing the E-field and dust concentration data, we further found that there is a significant positive linear relationship between the measured E-field intensity and dust concentration at the given ambient conditions. In addition, measurements and calculations demonstrate that a substantial enhancement in the vertical E-field can be observed several hours before the arrival of the external-source dust storms, indicating that the E-field can be used to provide an early warning of external-source dust storms.
Parameter-free calculation of single-particle electronic excitations in YH3
NASA Astrophysics Data System (ADS)
Gelderen, P. Van; Bobbert, P. A.; Kelly, P. J.; Brocks, G.; Tolboom, R.
2002-08-01
In recent optical experiments for YH3, a large band gap of almost 3 eV has been observed. In contrast, calculations within the local density approximation (LDA) result in a semimetallic band structure with a band overlap near the Fermi level of more than 1 eV. This unusually large discrepancy between the LDA results and experiment has led to suggestions that strong local correlation effects, similar to those found in transition metal oxides, are important in YH3. Here we conclude from parameter-free quasi-particle calculations within the GW approximation that YH3 is essentially a conventional semiconductor. We argue that the experimental results can be fully understood in band structure terms without invoking strong local correlations. The unusually large error in the band structure made by LDA is traced to its poor description of the electronic structure of the hydrogen atom. Our GW results predict a fundamental band gap of only 1 eV and an optical gap of 2.6 eV, the difference being due to vanishing matrix elements for optical transitions at lower energies. Our prediction of a small fundamental gap could be experimentally confirmed by a combination of photoemission and inverse photoemission experiments.
Weijo, Ville; Bast, Radovan; Manninen, Pekka; Saue, Trond; Vaara, Juha
2007-02-21
We examine the quantum chemical calculation of parity-violating (PV) electroweak contributions to the spectral parameters of nuclear magnetic resonance (NMR) from a methodological point of view. Nuclear magnetic shielding and indirect spin-spin coupling constants are considered and evaluated for three chiral molecules, H2O2, H2S2, and H2Se2. The effects of the choice of a one-particle basis set and the treatment of electron correlation, as well as the effects of special relativity, are studied. All of them are found to be relevant. The basis-set dependence is very pronounced, especially at the electron correlated ab initio levels of theory. Coupled-cluster and density-functional theory (DFT) results for PV contributions differ significantly from the Hartree-Fock data. DFT overestimates the PV effects, particularly with nonhybrid exchange-correlation functionals. Beginning from third-row elements, special relativity is of importance for the PV NMR properties, shown here by comparing perturbational one-component and various four-component calculations. In contrast to what is found for nuclear magnetic shielding, the choice of the model for nuclear charge distribution--point charge or extended (Gaussian)--has a significant impact on the PV contribution to the spin-spin coupling constants.
MCDHF calculations and study of plasma parameters for Li-like ions
NASA Astrophysics Data System (ADS)
Khatri, Indu; Goyal, Arun; Aggarwal, Sunny; Singh, A. K.; Man Mohan
2016-06-01
Extensive configuration interaction calculations for several Li-like ions (Z=32, 36, 42, 46, 50, 54 and 56) are performed using the code GRASP2K based on the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. Breit interaction and leading quantum electrodynamical (QED) effects are also included by applying active-space techniques to enlarge the configuration set. Results for fine-structure energy levels for 1s22p, 1s23s, 1s23p and 1s23d configurations with relative to ground states 1s22s are presented. The wavelengths, transition rates and oscillator strengths for the 1s22s 2S1/2-1s22p 1/2,3/2,0 2P, 1s22p 1/2,3/2,0,2P - -1s23s 2S1/2, 1s22p calculated results are in good agreement with previous theoretical results and compiled values of the National Institute for Standards and Technology (NIST). We have also provided the line intensity ratios and plasma parameters for optically thin plasma. Our calculated data may be useful for experimentalists in identifying the fine-structure levels, for plasma modeling, astrophysical research applications.
Test verification and design of the bicycle frame parameters
NASA Astrophysics Data System (ADS)
Zhang, Long; Xiang, Zhongxia; Luo, Huan; Tian, Guan
2015-07-01
Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders' worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers' height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes' function, and the new direction on future design of bicycle frame parameters is presented.
Calculation of radiation reaction effect on orbital parameters in Kerr spacetime
NASA Astrophysics Data System (ADS)
Sago, Norichika; Fujita, Ryuichi
2015-07-01
We calculate the secular changes of the orbital parameters of a point particle orbiting a Kerr black hole, due to the gravitational radiation reaction. For this purpose, we use the post-Newtonian (PN) approximation in the first-order black hole perturbation theory, with the expansion with respect to the orbital eccentricity. In this work, the calculation is done up to the fourth post-Newtonian (4PN) order and to the sixth order of the eccentricity, including the effect of the absorption of gravitational waves by the black hole. We confirm that, in the Kerr case, the effect of the absorption appears at the 2.5PN order beyond the leading order in the secular change of the particle's energy and may induce a superradiance, as known previously for circular orbits. In addition, we find that the superradiance may be suppressed when the orbital plane inclines with respect to the equatorial plane of the central black hole. We also investigate the accuracy of the 4PN formulae by comparing to numerical results. If we require that the relative errors in the 4PN formulae are less than 10^{-5}, the parameter region to satisfy the condition will be p≳ 50 for e=0.1, p≳ 80 for e=0.4, and p≳ 120 for e = 0.7 almost irrespective of the inclination angle or the spin of the black hole, where p and e are the semi-latus rectum and the eccentricity of the orbit. The region can further be extended using an exponential resummation method to p≳ 40 for e=0.1, p≳ 60 for e=0.4, and p≳ 100 for e=0.7. Although we still need the higher-order calculations of the PN approximation and the expansion with respect to the orbital eccentricity to apply for data analysis of gravitational waves, the results in this paper would be an important improvement from the previous work at the 2.5PN order, especially for large-p regions.
Linear parameter varying representations for nonlinear control design
NASA Astrophysics Data System (ADS)
Carter, Lance Huntington
Linear parameter varying (LPV) systems are investigated as a framework for gain-scheduled control design and optimal hybrid control. An LPV system is defined as a linear system whose dynamics depend upon an a priori unknown but measurable exogenous parameter. A gain-scheduled autopilot design is presented for a bank-to-turn (BTT) missile. The method is novel in that the gain-scheduled design does not involve linearizations about operating points. Instead, the missile dynamics are brought to LPV form via a state transformation. This idea is applied to the design of a coupled longitudinal/lateral BTT missile autopilot. The pitch and yaw/roll dynamics are separately transformed to LPV form, where the cross axis states are treated as "exogenous" parameters. These are actually endogenous variables, so such a plant is called "quasi-LPV." Once in quasi-LPV form, a family of robust controllers using mu synthesis is designed for both the pitch and yaw/roll channels, using angle-of-attack and roll rate as the scheduling variables. The closed-loop time response is simulated using the original nonlinear model and also using perturbed aerodynamic coefficients. Modeling and control of engine idle speed is investigated using LPV methods. It is shown how generalized discrete nonlinear systems may be transformed into quasi-LPV form. A discrete nonlinear engine model is developed and expressed in quasi-LPV form with engine speed as the scheduling variable. An example control design is presented using linear quadratic methods. Simulations are shown comparing the LPV based controller performance to that using PID control. LPV representations are also shown to provide a setting for hybrid systems. A hybrid system is characterized by control inputs consisting of both analog signals and discrete actions. A solution is derived for the optimal control of hybrid systems with generalized cost functions. This is shown to be computationally intensive, so a suboptimal strategy is proposed that
Design parameters for a FM/FM system
NASA Astrophysics Data System (ADS)
Carden, Frank
Design parameters for a FM/FM telemetry system are determined in terms of the IRIG specifications for proportional bandwidth channels. Three mathematical models used by designers of the above processes are extended and compared. That is, FM multi-tone models are used to establish the relationship between frequency deviations, modulation indices, signal-to-noise and IF bandwidth for the IRIG channels. Since spectral efficiency and signal quality are of major importance, a goal of the design is to have a minimum IF bandwidth, while fixing as large as possible the values of the modulation indices for the subcarriers modulating the carrier in order to achieve as large as needed output signal-to-noise ratio.
Design of Life Extending Controls Using Nonlinear Parameter Optimization
NASA Technical Reports Server (NTRS)
Lorenzo, Carl F.; Holmes, Michael S.; Ray, Asok
1998-01-01
This report presents the conceptual development of a life extending control system where the objective is to achieve high performance and structural durability of the plant. A life extending controller is designed for a reusable rocket engine via damage mitigation in both the fuel and oxidizer turbines while achieving high performance for transient responses of the combustion chamber pressure and the O2/H2 mixture ratio. This design approach makes use of a combination of linear and nonlinear controller synthesis techniques and also allows adaptation of the life extending controller module to augment a conventional performance controller of a rocket engine. The nonlinear aspect of the design is achieved using nonlinear parameter optimization of a prescribed control structure.
Kaufmann, Sascha; Schulze, Maximilian; Horger, Thomas; Oelker, Aenne; Nikolaou, Konstantin; Horger, Marius
2015-09-01
To assess the reproducibility of volume computed tomographic perfusion (VPCT) measurements in normal pancreatic tissue using two different kinetic perfusion calculation models at three different time points. Institutional ethical board approval was obtained for retrospective analysis of pancreas perfusion data sets generated by our prospective study for liver response monitoring to local therapy in patients experiencing unresectable hepatocellular carcinoma, which was approved by the institutional review board. VPCT of the entire pancreas was performed in 41 patients (mean age, 64.8 years) using 26 consecutive volume measurements and intravenous injection of 50 mL of iodinated contrast at a flow rate of 5 mL/s. Blood volume(BV) and blood flow (BF) were calculated using two mathematical methods: maximum slope + Patlak analysis versus deconvolution method. Pancreas perfusion was calculated using two volume of interests. Median interval between the first and the second VPCT was 2 days and between the second and the third VPCT 82 days. Variability was assessed with within-patient coefficients of variation (CVs) and Bland-Altman analyses. Interobserver agreement for all perfusion parameters was calculated using intraclass correlation coefficients (ICCs). BF and BV values varied widely by method of analysis as did within-patient CVs for BF and BV at the second versus the first VPCT by 22.4%/50.4% (method 1) and 24.6%/24.0% (method 2) measured in the pancreatic head and 18.4%/62.6% (method 1) and 23.8%/28.1% (method 2) measured in the pancreatic corpus and at the third versus the first VPCT by 21.7%/61.8% (method 1) and 25.7%/34.5% (method 2) measured also in the pancreatic head and 19.1%/66.1% (method 1) and 22.0%/31.8% (method 2) measured in the pancreatic corpus, respectively. Interobserver agreement measured with ICC shows fair-to-good reproducibility. VPCT performed with the presented examinational protocol is reproducible and can be used for monitoring
NASA Technical Reports Server (NTRS)
Rizk, Magdi H.
1988-01-01
A scheme is developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The scheme updates the design parameter iterative solutions and the flow variable iterative solutions simultaneously. It is applied to an advanced propeller design problem with the Euler equations used as the flow governing equations. The scheme's accuracy, efficiency and sensitivity to the computational parameters are tested.
NASA Technical Reports Server (NTRS)
Rizk, Magdi H.
1988-01-01
A scheme is developed for solving constrained optimization problems in which the objective function and the constraint function are dependent on the solution of the nonlinear flow equations. The scheme updates the design parameter iterative solutions and the flow variable iterative solutions simultaneously. It is applied to an advanced propeller design problem with the Euler equations used as the flow governing equations. The scheme's accuracy, efficiency and sensitivity to the computational parameters are tested.
Lens design based on lens form parameters using Gaussian brackets
NASA Astrophysics Data System (ADS)
Yuan, Xiangyu; Cheng, Xuemin
2014-11-01
The optical power distribution and the symmetry of the lens components are two important attributes that decide the ultimate lens performance and characteristics. Lens form parameters W and S are the key criteria describing the two attributes mentioned above. Lens components with smaller W and S will have a good nature of aberration balance and perform well in providing good image quality. Applying the Gaussian brackets, the two lens form parameters and the Seidel Aberration Coefficients are reconstructed. An initial lens structure can be analytically described by simultaneous equations of Seidel Aberration Coefficients and third-order aberration theory. Adding the constraints of parameters W and S in the solving process, a solution with a proper image quality and aberration distribution is achieved. The optical properties and image quality of the system based on the parameters W and S are also analyzed in this article. In the method, the aberration distribution can be controlled to some extent in the beginning of design, so that we can reduce some workload of optimization later.
Design Parameters Influencing Reliability of CCGA Assembly: A Sensitivity Analysis
NASA Technical Reports Server (NTRS)
Tasooji, Amaneh; Ghaffarian, Reza; Rinaldi, Antonio
2006-01-01
Area Array microelectronic packages with small pitch and large I/O counts are now widely used in microelectronics packaging. The impact of various package design and materials/process parameters on reliability has been studied through extensive literature review. Reliability of Ceramic Column Grid Array (CCGA) package assemblies has been evaluated using JPL thermal cycle test results (-50(deg)/75(deg)C, -55(deg)/100(deg)C, and -55(deg)/125(deg)C), as well as those reported by other investigators. A sensitivity analysis has been performed using the literature da to study the impact of design parameters and global/local stress conditions on assembly reliability. The applicability of various life-prediction models for CCGA design has been investigated by comparing model's predictions with the experimental thermal cycling data. Finite Element Method (FEM) analysis has been conducted to assess the state of the stress/strain in CCGA assembly under different thermal cycling, and to explain the different failure modes and locations observed in JPL test assemblies.
A two-parameter design storm for Mediterranean convective rainfall
NASA Astrophysics Data System (ADS)
García-Bartual, Rafael; Andrés-Doménech, Ignacio
2017-05-01
The following research explores the feasibility of building effective design storms for extreme hydrological regimes, such as the one which characterizes the rainfall regime of the east and south-east of the Iberian Peninsula, without employing intensity-duration-frequency (IDF) curves as a starting point. Nowadays, after decades of functioning hydrological automatic networks, there is an abundance of high-resolution rainfall data with a reasonable statistic representation, which enable the direct research of temporal patterns and inner structures of rainfall events at a given geographic location, with the aim of establishing a statistical synthesis directly based on those observed patterns. The authors propose a temporal design storm defined in analytical terms, through a two-parameter gamma-type function. The two parameters are directly estimated from 73 independent storms identified from rainfall records of high temporal resolution in Valencia (Spain). All the relevant analytical properties derived from that function are developed in order to use this storm in real applications. In particular, in order to assign a probability to the design storm (return period), an auxiliary variable combining maximum intensity and total cumulated rainfall is introduced. As a result, for a given return period, a set of three storms with different duration, depth and peak intensity are defined. The consistency of the results is verified by means of comparison with the classic method of alternating blocks based on an IDF curve, for the above mentioned study case.
Design Model Parameter Analysis for Nitrifying Trickling Filters.
Coats, Erik R
Nitrifying trickling filters (NTFs) represent an effective technology for water resource recovery facilities (WRRFs) to achieve compliance with ammonia-N permits. However, while the potential benefits of NTFs are many, the design methods and associated parameter databases are underdeveloped. Research herein focused on analysis of pilot-scale NTF data to develop enhanced design guidance. rn(max,0) values ranged from 1.19-3.38 gN m(-2)*d(-1), and correlated with influent ammonia-N concentration and loading. The transition concentration from rn(max,0) ranged from 0.9-22.2 mgN/L, and correlated with ammonia-N loading. Zero-order nitrification ranging from 0.24-1.58 gN m(-2)*d(-1) was observed down-gradient of rn(max,0). First-order nitrification was not observed, nor was there a strong exponential correlation for decreasing nitrification rate. To translate results to NTF media different from that utilized, a relationship between the NTF media effectiveness parameter, E, and rn(max,0) was established. Collectively, the data presented enhances the engineer's ability to model and design NTFs.
Design Parameters Influencing Reliability of CCGA Assembly: A Sensitivity Analysis
NASA Technical Reports Server (NTRS)
Tasooji, Amaneh; Ghaffarian, Reza; Rinaldi, Antonio
2006-01-01
Area Array microelectronic packages with small pitch and large I/O counts are now widely used in microelectronics packaging. The impact of various package design and materials/process parameters on reliability has been studied through extensive literature review. Reliability of Ceramic Column Grid Array (CCGA) package assemblies has been evaluated using JPL thermal cycle test results (-50(deg)/75(deg)C, -55(deg)/100(deg)C, and -55(deg)/125(deg)C), as well as those reported by other investigators. A sensitivity analysis has been performed using the literature da to study the impact of design parameters and global/local stress conditions on assembly reliability. The applicability of various life-prediction models for CCGA design has been investigated by comparing model's predictions with the experimental thermal cycling data. Finite Element Method (FEM) analysis has been conducted to assess the state of the stress/strain in CCGA assembly under different thermal cycling, and to explain the different failure modes and locations observed in JPL test assemblies.
Criteria for calculating the efficiency of HEPA filters during and after design basis accidents
Bergman, W.; First, M.W.; Anderson, W.L.; Gilbert, H.; Jacox, J.W.
1994-12-01
We have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data.
NASA Astrophysics Data System (ADS)
Ni, Qionglin; Fan, Tieshuan; Zhang, Xing; Zhang, Cheng; Ren, Qilong; Hu, Chundong
2010-12-01
A predictive calculation is carried out for neutral beam heating of fusion plasmas in EAST by using NUBEAM code under certain plasma conditions. Results calculated are analyzed for different plasma parameters. Relations between major plasma parameters, such as density and temperature, are obtained and key physical processes in the neutral beam heating, including beam power deposition, trapped fraction, heating efficiency, and power loss, are simulated. Other physical processes, such as current-drive, toroidal rotation and neutron emission, are also discussed.
Man, Jun; Zhang, Jiangjiang; Li, Weixuan; Zeng, Lingzao; Wu, Laosheng
2016-10-01
The ensemble Kalman filter (EnKF) has been widely used in parameter estimation for hydrological models. The focus of most previous studies was to develop more efficient analysis (estimation) algorithms. On the other hand, it is intuitively understandable that a well-designed sampling (data-collection) strategy should provide more informative measurements and subsequently improve the parameter estimation. In this work, a Sequential Ensemble-based Optimal Design (SEOD) method, coupled with EnKF, information theory and sequential optimal design, is proposed to improve the performance of parameter estimation. Based on the first-order and second-order statistics, different information metrics including the Shannon entropy difference (SD), degrees of freedom for signal (DFS) and relative entropy (RE) are used to design the optimal sampling strategy, respectively. The effectiveness of the proposed method is illustrated by synthetic one-dimensional and two-dimensional unsaturated flow case studies. It is shown that the designed sampling strategies can provide more accurate parameter estimation and state prediction compared with conventional sampling strategies. Optimal sampling designs based on various information metrics perform similarly in our cases. The effect of ensemble size on the optimal design is also investigated. Overall, larger ensemble size improves the parameter estimation and convergence of optimal sampling strategy. Although the proposed method is applied to unsaturated flow problems in this study, it can be equally applied in any other hydrological problems.
Fast, Ivan; Aksyutina, Yuliya; Tietze-Jaensch, Holger
2013-07-01
Burn up calculations facilitate a determination of the composition and nuclear inventory of spent nuclear fuel, if operational history is known. In case this information is not available, the total nuclear inventory can be determined by means of destructive or, even on industrial scale, nondestructive measurement methods. For non-destructive measurements however only a few easy-to-measure, so-called key nuclides, are determined due to their characteristic gamma lines or neutron emission. From these measured activities the fuel burn up and cooling time are derived to facilitate the numerical inventory determination of spent fuel elements. Most regulatory bodies require an independent assessment of nuclear waste properties and their documentation. Prominent part of this assessment is a consistency check of inventory declaration. The waste packages often contain wastes from different types of spent fuels of different history and information about the secondary reactor parameters may not be available. In this case the so-called characteristic fuel burn up and cooling time are determined. These values are obtained from a correlations involving key-nuclides with a certain bandwidth, thus with upper and lower limits. The bandwidth is strongly dependent on secondary reactor parameter such as initial enrichment, temperature and density of the fuel and moderator, hence the reactor type, fuel element geometry and plant operation history. The purpose of our investigation is to look into the scaling and correlation limitations, to define and verify the range of validity and to scrutinize the dependencies and propagation of uncertainties that affect the waste inventory declarations and their independent verification. This is accomplished by numerical assessment and simulation of waste production using well accepted codes SCALE 6.0 and 6.1 to simulate the cooling time and burn up of a spent fuel element. The simulations are benchmarked against spent fuel from the real reactor
Indoor design condition and the cooling load calculation
Sun, T.Y.
1997-12-01
Cooling load calculation involves two steps. The first is to determine the basic building load. This consists of external loads through the building envelope and internal loads from people, lights, appliances, and other heat sources. The required supply air quantity for each conditioned space generally is determined in the first step. This is because each relates only to the coil leaving and required room dry bulb temperatures (unless reheat is required to control the humidity level in the conditioned space). The second step, after completing the above, is to calculate the system cooling load. This step adapts the selected air distribution system to the building load and involves the introduction of the required outdoor air volume into the air conditioning system for ventilation. Proper psychrometric analysis is required to calculate the entering and leaving wet bulb conditions of the air passing through the cooling coil. These, together with the corresponding dry bulb temperatures, will determine the system cooling load.
Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter
Li, Huidong; Deng, Zhiqun Daniel; Yuan, Yong; Carlson, Thomas J.
2012-01-01
PZT ceramics have been widely used in underwater acoustic transducers. However, literature available discussing the design parameters of a miniaturized PZT-based low-duty-cycle transmitter is very limited. This paper discusses some of the design parameters—the backing material, driving voltage, PZT material type, power consumption and the transducer length of a miniaturized acoustic fish tag using a PZT tube. Four different types of PZT were evaluated with respect to the source level, energy consumption and bandwidth of the transducer. The effect of the tube length on the source level is discussed. The results demonstrate that ultralow-density closed-cell foam is the best backing material for the PZT tube. The Navy Type VI PZTs provide the best source level with relatively low energy consumption and that a low transducer capacitance is preferred for high efficiency. A 35% reduction in the transducer length results in 2 dB decrease in source level. PMID:23012534
Studies of design parameters for interferometric methane sensors
NASA Astrophysics Data System (ADS)
Wykes, John S.; Willett, Martin J.; Croydon, W. F.
1992-08-01
Methane detectors based on the absorption of infrared radiation show some promise as the basis of sensitive and accurate industrial instrumentation. Comb filter methods that utilize the vibration-rotation structure of the methane spectrum in an optically efficient manner have recently aroused particular interest in this context. We describe a mathematical model to simulate the behavior of scanning interferometric comb filters in methane detection systems and discuss the use of the model to investigate optimum design parameters for such systems. The behavior of prototype methane detectors based on scanning Fabry-Perot and Mach Zehnder interferometers is briefly reported. Possible techniques for obtaining further improvements in the design of comb filters for methane detection are suggested.
An integral equation solution for multistage turbomachinery design calculations
NASA Technical Reports Server (NTRS)
Mcfarland, Eric R.
1993-01-01
A method was developed to calculate flows in multistage turbomachinery. The method is an extension of quasi-three-dimensional blade-to-blade solution methods. Governing equations for steady compressible inviscid flow are linearized by introducing approximations. The linearized flow equations are solved using integral equation techniques. The flows through both stationary and rotating blade rows are determined in a single calculation. Multiple bodies can be modelled for each blade row, so that arbitrary blade counts can be analyzed. The method's benefits are its speed and versatility.
Valentine, T.E.; Mihalczo, J.T.
1995-12-31
This paper describes calculations performed to validate the modified version of the MCNP code, the MCNP-DSP, used for: the neutron and photon spectra of the spontaneous fission of californium 252; the representation of the detection processes for scattering detectors; the timing of the detection process; and the calculation of the frequency analysis parameters for the MCNP-DSP code.
Numerical investigation of design and operational parameters on CHI spheromak performance
NASA Astrophysics Data System (ADS)
O'Bryan, J. B.; Romero-Talamas, C. A.; Woodruff, S.
2016-10-01
Nonlinear, extended-MHD computation with the NIMROD code is used to explore magnetic self-organization and performance with respect to externally controllable parameters in spheromaks formed with coaxial helicity injection. The goal of this study is to inform the design and operational parameters of proposed proof-of-principle spheromak experiment. The calculations explore multiple distinct phases of evolution (including adiabatic magnetic compression), which must be explored and optimized separately. Results indicate that modest changes to the design and operation of past experiments, e.g. SSPX [E.B. Hooper et al. PPCF 2012], could have significantly improved the plasma-current injector coupling efficiency and performance, particularly with respect to peak temperature and lifetime. Though we frequently characterize performance relative to SSPX, we are also exploring fundamentally different designs and modes of operation, e.g. flux compression. This work is supported by DAPRA under Grant No. N66001-14-1-4044.
NASA Astrophysics Data System (ADS)
Makarycheva, A. I.; Faerman, V. A.
2017-02-01
The analyses of automation patterns is performed and the programming solution for the automation of data processing of the chromatographic data and their further information storage with a help of a software package, Mathcad and MS Excel spreadsheets, is developed. The offered approach concedes the ability of data processing algorithm modification and does not require any programming experts participation. The approach provides making a measurement of the given time and retention volumes, specific retention volumes, a measurement of differential molar free adsorption energy, and a measurement of partial molar solution enthalpies and isosteric heats of adsorption. The developed solution is focused on the appliance in a small research group and is tested on the series of some new gas chromatography sorbents. More than 20 analytes were submitted to calculation of retention parameters and thermodynamic sorption quantities. The received data are provided in the form accessible to comparative analysis, and they are able to find sorbing agents with the most profitable properties to solve some concrete analytic issues.
Pickrahn, Ines; Müller, Eva; Zahrer, Waltraud; Dunkelmann, Bettina; Cemper-Kiesslich, Jan; Kreindl, Gabriele; Neuhuber, Franz
2016-03-01
With the new 6-dye AmpFISTR(®) Yfiler(®) Plus amplification kit (Thermo Fisher Scientific, Waltham, MA, USA) a set of 25 Y-chromosomal short tandem repeat loci (Y-STRs), including seven rapidly mutating Y-STRs (RM Y-STRs), is now available for forensic DNA typing. In this study we present our validation data for the AmpFISTR(®) Yfiler(®) Plus amplification kit and show the results of Y-chromosomal typing of 425 unrelated male individuals from two Austrian populations (Salzburg and Upper Austria) with the AmpFISTR(®) Yfiler(®) Plus amplification kit. Forensic parameters were calculated and compared for four Y-STR marker sets. We also typed five brother pairs to evaluate the power of discrimination for related individuals. The AmpFISTR(®) Yfiler(®) Plus (Yfiler Plus) kit appeared to be unimpaired by typical inhibitors such as hematin and humic acid or by large amounts of female components. An upgrade of analyzed markers resulted in increased discrimination capacity that is crucial for forensic trace analysis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
McConathy, R.K.
1983-03-01
The study describes the gradients of stomatal size and density in the crown of a mature forest-grown tulip-poplar (Liriodendron tulipifera L.) in eastern Tennessee. These data are used to predict leaf resistance to vapor diffusion in relation to stomatal width and boundary layer resistance. Stomatal density on individual leaves did not vary, but density increased with increasing crown height. Stomatal size decreased with increasing height of leaves within the crown. Stomatal size and density variations interacted to result in a constant number of stomata per leaf at all crown heights. Stomatal diffusive resistance values calculated from stomatal measurements and varying environmental parameters indicated that stomatal resistance controlled transpiration water losses only at small apertures (<0.6 ..mu..m). Boundary layer resistance was controlling at large stomatal apertures (>0.6 ..mu..m) and at low wind speeds (approx.100 cm/s). Under normal forest conditions tulip-poplar stomatal resistance exercised more control over transpiration than did boundary layer resistance.
Effects of Microneedle Design Parameters on Hydraulic Resistance.
Hood, R Lyle; Kosoglu, Mehmet A; Parker, Matthew; Rylander, Christopher G
2011-09-01
Microneedles have been an expanding medical technology in recent years due to their ability to penetrate tissue and deliver therapy with minimal invasiveness and patient discomfort. Variations in design have allowed for enhanced fluid delivery, biopsy collection, and the measurement of electric potentials. Our novel microneedle design attempts to combine many of these functions into a single length of silica tubing capable of both light and fluid delivery terminating in a sharp tip of less than 100 microns in diameter. This manuscript focuses on the fluid flow aspects of the design, characterizing the contributions to hydraulic resistance from the geometric parameters of the microneedles. Experiments consisted of measuring the volumetric flow rate of de-ionized water at set pressures (ranging from 69-621 kPa) through a relevant range of tubing lengths, needle lengths, and needle tip diameters. Data analysis showed that the silica tubing (~150 micron bore diameter) adhered to within ±5% of the theoretical prediction by Poiseuille's Law describing laminar internal pipe flow at Reynolds numbers less than 700. High hydraulic resistance within the microneedles correlated with decreasing tip diameter. The hydraulic resistance offered by the silica tubing preceding the microneedle taper was approximately 1-2 orders of magnitude less per unit length, but remained the dominating resistance in most experiments as the tubing length was >30 mm. These findings will be incorporated into future design permutations to produce a microneedle capable of both efficient fluid transfer and light delivery.
Efficient global optimization of a limited parameter antenna design
NASA Astrophysics Data System (ADS)
O'Donnell, Teresa H.; Southall, Hugh L.; Kaanta, Bryan
2008-04-01
Efficient Global Optimization (EGO) is a competent evolutionary algorithm suited for problems with limited design parameters and expensive cost functions. Many electromagnetics problems, including some antenna designs, fall into this class, as complex electromagnetics simulations can take substantial computational effort. This makes simple evolutionary algorithms such as genetic algorithms or particle swarms very time-consuming for design optimization, as many iterations of large populations are usually required. When physical experiments are necessary to perform tradeoffs or determine effects which may not be simulated, use of these algorithms is simply not practical at all due to the large numbers of measurements required. In this paper we first present a brief introduction to the EGO algorithm. We then present the parasitic superdirective two-element array design problem and results obtained by applying EGO to obtain the optimal element separation and operating frequency to maximize the array directivity. We compare these results to both the optimal solution and results obtained by performing a similar optimization using the Nelder-Mead downhill simplex method. Our results indicate that, unlike the Nelder-Mead algorithm, the EGO algorithm did not become stuck in local minima but rather found the area of the correct global minimum. However, our implementation did not always drill down into the precise minimum and the addition of a local search technique seems to be indicated.
Zhang, Ke; Jiang, Bin; Shi, Peng
2017-02-01
In this paper, a novel adjustable parameter (AP)-based distributed fault estimation observer (DFEO) is proposed for multiagent systems (MASs) with the directed communication topology. First, a relative output estimation error is defined based on the communication topology of MASs. Then a DFEO with AP is constructed with the purpose of improving the accuracy of fault estimation. Based on H ∞ and H 2 with pole placement, multiconstrained design is given to calculate the gain of DFEO. Finally, simulation results are presented to illustrate the feasibility and effectiveness of the proposed DFEO design with AP.
Design and parameter optimization of flip-chip bonder
NASA Astrophysics Data System (ADS)
Shim, Hyoungsub; Kang, Heuiseok; Jeong, Hoon; Cho, Youngjune; Kim, Wansoo; Kang, Shinill
2005-12-01
Bare-chip packaging becomes more popular along with the miniaturization of IT components. In this paper, we have studied flip-chip process, and developed automated bonding system. Among the several bonding method, NCP bonding is chosen and batch-type equipment is manufactured. The dual optics and vision system aligns the chip with the substrate. The bonding head equipped with temperature and force controllers bonds the chip. The system can be easily modified for other bonding methods such as ACF. In bonding process, the bonding force and temperature are known as the most dominant bonding parameters. A parametric study is performed for these two parameters. For the test sample, we used standard flip-chip test kit which consists of FR4 boards and dummy flip-chips. The bonding temperatures are chosen between 25°C to 300°C. The bonding forces are chosen between 5N and 300N. To test the bonding strength, a bonding strength tester was designed and constructed. After the bonding strength test, the samples are examined by microscope to determine the failure mode. The relations between the bonding strength and the bonding parameters are analyzed and compared with bonding models. Finally, the most suitable bonding condition is suggested in terms of temperature and force.
Knitted Strain Sensors: Impact of Design Parameters on Sensing Properties
Atalay, Ozgur; Kennon, William Richard
2014-01-01
This paper presents a study of the sensing properties exhibited by textile-based knitted strain sensors. Knitted sensors were manufactured using flat-bed knitting technology, and electro-mechanical tests were subsequently performed on the specimens using a tensile testing machine to apply strain whilst the sensor was incorporated into a Wheatstone bridge arrangement to allow electrical monitoring. The sensing fabrics were manufactured from silver-plated nylon and elastomeric yarns. The component yarns offered similar diameters, bending characteristics and surface friction, but their production parameters differed in respect of the required yarn input tension, the number of conductive courses in the sensing structure and the elastomeric yarn extension characteristics. Experimental results showed that these manufacturing controls significantly affected the sensing properties of the knitted structures such that the gauge factor values, the working range and the linearity of the sensors varied according to the knitted structure. These results confirm that production parameters play a fundamental role in determining the physical behavior and the sensing properties of knitted sensors. It is thus possible to manipulate the sensing properties of knitted sensors and the sensor response may be engineered by varying the production parameters applied to specific designs. PMID:24608010
Experimental investigation of design parameters on dry powder inhaler performance.
Ngoc, Nguyen Thi Quynh; Chang, Lusi; Jia, Xinli; Lau, Raymond
2013-11-30
The study aims to investigate the impact of various design parameters of a dry powder inhaler on the turbulence intensities generated and the performance of the dry powder inhaler. The flow fields and turbulence intensities in the dry powder inhaler are measured using particle image velocimetry (PIV) techniques. In vitro aerosolization and deposition a blend of budesonide and lactose are measured using an Andersen Cascade Impactor. Design parameters such as inhaler grid hole diameter, grid voidage and chamber length are considered. The experimental results reveal that the hole diameter on the grid has negligible impact on the turbulence intensity generated in the chamber. On the other hand, hole diameters smaller than a critical size can lead to performance degradation due to excessive particle-grid collisions. An increase in grid voidage can improve the inhaler performance but the effect diminishes at high grid voidage. An increase in the chamber length can enhance the turbulence intensity generated but also increases the powder adhesion on the inhaler wall.
Wang, Chunhao; Yin, Fang-Fang; Chang, Zheng
2016-02-01
To develop an efficient method for calculating pharmacokinetic (PK) parameters in brain DCE-MRI permeability studies. A linear least-squares fitting algorithm based on a derivative expression of the two-compartment PK model was proposed to analytically solve for the PK parameters. Noise in the expression was minimized through low-pass filtering. Simulation studies were conducted in which the proposed method was compared with two existing methods in terms of accuracy and efficiency. Five in vivo brain studies were demonstrated for potential clinical application. In the simulation studies using chosen parameter values, the calculated percent difference of K(trans) by the proposed method was <5.0% with a temporal resolution (Δt) < 5 s, and the accuracies of all parameter results were better or comparable to existing methods. When analyzed within certain parameter intensity ranges, the proposed method was more accurate than the existing methods and improved the efficiency by a factor of up to 458 for a Δt = 1 s and up to 38 for a Δt = 5 s. In the in vivo study, the calculated parameters using the proposed method were comparable to those using the existing methods with improved efficiencies. An efficient method was developed for the accurate and efficient calculation of parameters in brain DCE-MRI permeability studies. © 2015 Wiley Periodicals, Inc.
How to calculate sample size for different study designs in medical research?
Charan, Jaykaran; Biswas, Tamoghna
2013-04-01
Calculation of exact sample size is an important part of research design. It is very important to understand that different study design need different method of sample size calculation and one formula cannot be used in all designs. In this short review we tried to educate researcher regarding various method of sample size calculation available for different study designs. In this review sample size calculation for most frequently used study designs are mentioned. For genetic and microbiological studies readers are requested to read other sources.
Cold-Crucible Design Parameters for Next Generation HLW Melters
Gombert, D.; Richardson, J.; Aloy, A.; Day, D.
2002-02-26
The cold-crucible induction melter (CCIM) design eliminates many materials and operating constraints inherent in joule-heated melter (JHM) technology, which is the standard for vitrification of high-activity wastes worldwide. The cold-crucible design is smaller, less expensive, and generates much less waste for ultimate disposal. It should also allow a much more flexible operating envelope, which will be crucial if the heterogeneous wastes at the DOE reprocessing sites are to be vitrified. A joule-heated melter operates by passing current between water-cooled electrodes through a molten pool in a refractory-lined chamber. This design is inherently limited by susceptibility of materials to corrosion and melting. In addition, redox conditions and free metal content have exacerbated materials problems or lead to electrical short-circuiting causing failures in DOE melters. In contrast, the CCIM design is based on inductive coupling of a water-cooled high-frequency electrical coil with the glass, causing eddycurrents that produce heat and mixing. A critical difference is that inductance coupling transfers energy through a nonconductive solid layer of slag coating the metal container inside the coil, whereas the jouleheated design relies on passing current through conductive molten glass in direct contact with the metal electrodes and ceramic refractories. The frozen slag in the CCIM design protects the containment and eliminates the need for refractory, while the corrosive molten glass can be the limiting factor in the JH melter design. The CCIM design also eliminates the need for electrodes that typically limit operating temperature to below 1200 degrees C. While significant marketing claims have been made by French and Russian technology suppliers and developers, little data is available for engineering and economic evaluation of the technology, and no facilities are available in the US to support testing. A currently funded project at the Idaho National Engineering
Analytical calculation of the quantum 1/f coherence parameter for HFETs
NASA Astrophysics Data System (ADS)
Handel, Peter H.; Sherif, Taher S.
2010-03-01
The ratio s of the coherent magnetic energy term and the incoherent mechanical kinetic energy terms of the drift motion in the hamiltonian of a current carrying system is calculated for the special cases of a HFET or FET. This ratio defines the resulting quantum 1/f noise from the coherent and conventional quantum 1/f effects. In this case of FETs and HFETs of much larger width w>>LDS>t, the kinetic energy Ek of average motion with drift velocity vd per unit length in the direction of the drain-source distance LDS in the channel of thickness t, is still given by Nmvd 2/2, but the magnetic energy Em per unit length in the direction of LDS is roughly proportional with the first power of w only, instead of w2, and can be approximated by Em = π[ln(w/2LDS)]LDS[nevS/c]2/w. Here S=wt is the cross section though which current flows this indicates field-decoherence along the large device width w. This yields a coherence ratio of s ≡ Em/Ek ~ πnrotLDSln(w/2LDS), which shows that only an effective width w=weff about equal to LDS should be used in the calculation of s in this special case; larger widths are subject to de-coherence. This favors lower, mainly conventional, quantum 1/f noise in these devices, in spite of the large values of w. It also explains for the first time why the huge widths are possible with impunity, i.e., without causing the much larger coherent quantum 1/f noise to appear. For non-uniform current distribution across t, and for piezoelectric coupling, improved forms are derived for s. Specifically, the coherence parameter, called s' for the piezo case, is given by s' = (gN'h/m*vs)( vs/u)3F(u/vs)t/12w, where F(u/vs) = (2/3)(u/vs) for small drift velocity u, much smaller than the sound velocity vs in the semiconductor. Here N'=nwt.
Jaciw, Andrew P; Lin, Li; Ma, Boya
2016-10-18
Prior research has investigated design parameters for assessing average program impacts on achievement outcomes with cluster randomized trials (CRTs). Less is known about parameters important for assessing differential impacts. This article develops a statistical framework for designing CRTs to assess differences in impact among student subgroups and presents initial estimates of critical parameters. Effect sizes and minimum detectable effect sizes for average and differential impacts are calculated before and after conditioning on effects of covariates using results from several CRTs. Relative sensitivities to detect average and differential impacts are also examined. Student outcomes from six CRTs are analyzed. Achievement in math, science, reading, and writing. The ratio of between-cluster variation in the slope of the moderator divided by total variance-the "moderator gap variance ratio"-is important for designing studies to detect differences in impact between student subgroups. This quantity is the analogue of the intraclass correlation coefficient. Typical values were .02 for gender and .04 for socioeconomic status. For studies considered, in many cases estimates of differential impact were larger than of average impact, and after conditioning on effects of covariates, similar power was achieved for detecting average and differential impacts of the same size. Measuring differential impacts is important for addressing questions of equity, generalizability, and guiding interpretation of subgroup impact findings. Adequate power for doing this is in some cases reachable with CRTs designed to measure average impacts. Continuing collection of parameters for assessing differential impacts is the next step. © The Author(s) 2016.
Sato, H; Sato, S; Wang, Y M; Horikoshi, I
1996-06-01
We developed a package of macro programs (named PK_MOMENT) to automatically calculate non-compartmental pharmacokinetic parameters on Microsoft Excel spreadsheets. These macros include rigorous algorithms to execute moment calculations in a comprehensive manner. An optimum number of terminal data points for infinite-time extrapolation can be calculated with one of these macros so that automatic calculation of infinite moment parameters is possible. The moment calculation with PK_MOMENT provided satisfactory results using the hybrid (mixed linear-logarithmic) trapezoidal method rather than the conventional linear trapezoidal method. The macro-aided pharmacokinetic analyses turned out to be useful in that the macro-containing cells can be easily copied and pasted to analyze other data sets and that powerful tools of Excel can be utilized. The use of our macros will be significantly time-saving for routine pharmacokinetic analyses, considering that pharmacokinetic data are usually stored in a spreadsheet format, typically with Excel.
Dietrich, Johannes W.; Landgrafe-Mende, Gabi; Wiora, Evelin; Chatzitomaris, Apostolos; Klein, Harald H.; Midgley, John E. M.; Hoermann, Rudolf
2016-01-01
Although technical problems of thyroid testing have largely been resolved by modern assay technology, biological variation remains a challenge. This applies to subclinical thyroid disease, non-thyroidal illness syndrome, and those 10% of hypothyroid patients, who report impaired quality of life, despite normal thyrotropin (TSH) concentrations under levothyroxine (L-T4) replacement. Among multiple explanations for this condition, inadequate treatment dosage and monotherapy with L-T4 in subjects with impaired deiodination have received major attention. Translation to clinical practice is difficult, however, since univariate reference ranges for TSH and thyroid hormones fail to deliver robust decision algorithms for therapeutic interventions in patients with more subtle thyroid dysfunctions. Advances in mathematical and simulative modeling of pituitary–thyroid feedback control have improved our understanding of physiological mechanisms governing the homeostatic behavior. From multiple cybernetic models developed since 1956, four examples have also been translated to applications in medical decision-making and clinical trials. Structure parameters representing fundamental properties of the processing structure include the calculated secretory capacity of the thyroid gland (SPINA-GT), sum activity of peripheral deiodinases (SPINA-GD) and Jostel’s TSH index for assessment of thyrotropic pituitary function, supplemented by a recently published algorithm for reconstructing the personal set point of thyroid homeostasis. In addition, a family of integrated models (University of California-Los Angeles platform) provides advanced methods for bioequivalence studies. This perspective article delivers an overview of current clinical research on the basis of mathematical thyroid models. In addition to a summary of large clinical trials, it provides previously unpublished results of validation studies based on simulation and clinical samples. PMID:27375554
Dietrich, Johannes W; Landgrafe-Mende, Gabi; Wiora, Evelin; Chatzitomaris, Apostolos; Klein, Harald H; Midgley, John E M; Hoermann, Rudolf
2016-01-01
Although technical problems of thyroid testing have largely been resolved by modern assay technology, biological variation remains a challenge. This applies to subclinical thyroid disease, non-thyroidal illness syndrome, and those 10% of hypothyroid patients, who report impaired quality of life, despite normal thyrotropin (TSH) concentrations under levothyroxine (L-T4) replacement. Among multiple explanations for this condition, inadequate treatment dosage and monotherapy with L-T4 in subjects with impaired deiodination have received major attention. Translation to clinical practice is difficult, however, since univariate reference ranges for TSH and thyroid hormones fail to deliver robust decision algorithms for therapeutic interventions in patients with more subtle thyroid dysfunctions. Advances in mathematical and simulative modeling of pituitary-thyroid feedback control have improved our understanding of physiological mechanisms governing the homeostatic behavior. From multiple cybernetic models developed since 1956, four examples have also been translated to applications in medical decision-making and clinical trials. Structure parameters representing fundamental properties of the processing structure include the calculated secretory capacity of the thyroid gland (SPINA-GT), sum activity of peripheral deiodinases (SPINA-GD) and Jostel's TSH index for assessment of thyrotropic pituitary function, supplemented by a recently published algorithm for reconstructing the personal set point of thyroid homeostasis. In addition, a family of integrated models (University of California-Los Angeles platform) provides advanced methods for bioequivalence studies. This perspective article delivers an overview of current clinical research on the basis of mathematical thyroid models. In addition to a summary of large clinical trials, it provides previously unpublished results of validation studies based on simulation and clinical samples.
NASA Astrophysics Data System (ADS)
Zurek, Sebastian; Guzik, Przemyslaw; Pawlak, Sebastian; Kosmider, Marcin; Piskorski, Jaroslaw
2012-12-01
We explore the relation between correlation dimension, approximate entropy and sample entropy parameters, which are commonly used in nonlinear systems analysis. Using theoretical considerations we identify the points which are shared by all these complexity algorithms and show explicitly that the above parameters are intimately connected and mutually interdependent. A new geometrical interpretation of sample entropy and correlation dimension is provided and the consequences for the interpretation of sample entropy, its relative consistency and some of the algorithms for parameter selection for this quantity are discussed. To get an exact algorithmic relation between the three parameters we construct a very fast algorithm for simultaneous calculations of the above, which uses the full time series as the source of templates, rather than the usual 10%. This algorithm can be used in medical applications of complexity theory, as it can calculate all three parameters for a realistic recording of 104 points within minutes with the use of an average notebook computer.
NASA Astrophysics Data System (ADS)
Reyer, Dorothea; Philipp, Sonja
2014-05-01
It is desirable to enlarge the profit margin of geothermal projects by reducing the total drilling costs considerably. Substantiated assumptions on uniaxial compressive strengths and failure criteria are important to avoid borehole instabilities and adapt the drilling plan to rock mechanical conditions to minimise non-productive time. Because core material is rare we aim at predicting in situ rock properties from outcrop analogue samples which are easy and cheap to provide. The comparability of properties determined from analogue samples with samples from depths is analysed by performing physical characterisation (P-wave velocities, densities), conventional triaxial tests, and uniaxial compressive strength tests of both quarry and equivalent core samples. "Equivalent" means that the quarry sample is of the same stratigraphic age and of comparable sedimentary facies and composition as the correspondent core sample. We determined the parameters uniaxial compressive strength (UCS) and Young's modulus for 35 rock samples from quarries and 14 equivalent core samples from the North German Basin. A subgroup of these samples was used for triaxial tests. For UCS versus Young's modulus, density and P-wave velocity, linear- and non-linear regression analyses were performed. We repeated regression separately for clastic rock samples or carbonate rock samples only as well as for quarry samples or core samples only. Empirical relations were used to calculate UCS values from existing logs of sampled wellbore. Calculated UCS values were then compared with measured UCS of core samples of the same wellbore. With triaxial tests we determined linearized Mohr-Coulomb failure criteria, expressed in both principal stresses and shear and normal stresses, for quarry samples. Comparison with samples from larger depths shows that it is possible to apply the obtained principal stress failure criteria to clastic and volcanic rocks, but less so for carbonates. Carbonate core samples have higher
Parameter spaces and design optimization of thermoacoustic refrigerators
Wetzel, M.; Herman, C.
1996-12-31
In the last two decades thermoacoustic refrigerators were developed in research laboratories with the goal to understand the basic physics and thermodynamics of thermoacoustic heat pumping. These research efforts led to a good understanding of this new environmentally safe refrigeration technology that employs acoustic power to pump heat. Consequently the next step is to improve and optimize the performance of thermoacoustic refrigerators and seek commercial applications. For this purpose, the need for fast and simple engineering estimates arises. By implementing the simplified linear model of thermoacoustic refrigerators--the short stack boundary layer approximation--such design estimates were derived and presented in this paper in the form of a design algorithm. Calculations obtained with this algorithm predict values for the Coefficient Of Performance (COP) of the order of 5 to 6. These values cannot be achieved at this time because of loss mechanisms in key parts of the thermoacoustic refrigerator, which are not quite understood yet. Nevertheless, these values are encouraging and gaining a better understanding of these loss mechanisms will be a big step towards the commercial market for this new environmentally safe refrigeration technology.
Sensitivity of p-nuclei abundance calculations to statistical model parameters
NASA Astrophysics Data System (ADS)
Roach, Brandon; Simon, Anna
2017-01-01
Many reactions relevant to astrophysics involve nuclei far from stability, and their cross sections must therefore be calculated numerically for input into large-scale stellar nucleosynthesis calculations. Recent work, especially regarding p-process nucleosynthesis, has shown that the observed astrophysical abundances of certain nuclides differ by almost a factor of 10 from those predicted by network calculations using accepted reaction rates. Additionally, significant differences between calculated abundances when using different versions of these rates have been obtained. We therefore present the abundances of p-nuclei calculated using the open-source NucNet Tools code for a 25 solar mass type II supernova model, incorporating reaction cross sections calculated using the statistical-model code TALYS using several α optical potentials and γ-strength functions. This work is supported by the NSF under Grant Numbers PHY-1614442 and PHY-1430152 (JINA-CEE).
Napier, B.A.; Farris, W.T.; Simpson, J.C.
1992-12-01
A series of scoping calculations has been undertaken to evaluate the absolute and relative contribution of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford site. This scoping calculation (Calculation 005) examined the contributions of numerous parameters to the uncertainty distribution of doses calculated for environmental exposures and accumulation in foods. This study builds on the work initiated in the first scoping study of iodine in cow`s milk and the third scoping study, which added additional pathways. Addressed in this calculation were the contributions to thyroid dose of infants from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows` milk from Feeding Regime 1 as described in Calculation 001.
NASA Astrophysics Data System (ADS)
Ahmadinejad, Neda; Tari, Mostafa Talebi
2017-04-01
A density functional theory (DFT) calculations using B3LYP/6-311++G( d,p) method were carried out to investigate the relative stability of the molecules of β-carboline derivatives such as harmaline, harmine, harmalol, harmane and norharmane. Calculated nuclear quadrupole resonance (NQR) parameters were used to determine the 14N nuclear quadrupole coupling constant χ, asymmetry parameter η and EFG tensor ( q zz ). For better understanding of the electronic structure of β-carboline derivatives, natural bond orbital (NBO) analysis, isotropic and anisotropic NMR chemical shieldings were calculated for 14N nuclei using GIAO method for the optimized structures. The NBO analysis shows that pyrrole ring nitrogen (N9) atom has greater tendency than pyridine ring nitrogen (N2) atom to participate in resonance interactions and aromaticity development in the all of these structures. The NMR and NQR parameters were studied in order to find the correlations between electronic structure and the structural stability of the studied molecules.
Traction calculations and design data for two traction fluids
NASA Technical Reports Server (NTRS)
Tevaarwerk, J. L.
1983-01-01
The rheological properties of the fluid under these certain conditions which precludes the use of most of the conventional instruments for steady state measurement were studied. The only suitable type of instrument is a disk machine where most of the conditions are the same of similar to those in traction drives. From the resulting traction tests, certain models are inferred. To the designer of traction drives, the traction behavior of the fluid under the severe conditions is of utmost importance because of the direct influence that it has on the efficiency, size, and life of a given drive.
Technique for Calculating Solution Derivatives With Respect to Geometry Parameters in a CFD Code
NASA Technical Reports Server (NTRS)
Mathur, Sanjay
2011-01-01
A solution has been developed to the challenges of computation of derivatives with respect to geometry, which is not straightforward because these are not typically direct inputs to the computational fluid dynamics (CFD) solver. To overcome these issues, a procedure has been devised that can be used without having access to the mesh generator, while still being applicable to all types of meshes. The basic approach is inspired by the mesh motion algorithms used to deform the interior mesh nodes in a smooth manner when the surface nodes, for example, are in a fluid structure interaction problem. The general idea is to model the mesh edges and nodes as constituting a spring-mass system. Changes to boundary node locations are propagated to interior nodes by allowing them to assume their new equilibrium positions, for instance, one where the forces on each node are in balance. The main advantage of the technique is that it is independent of the volumetric mesh generator, and can be applied to structured, unstructured, single- and multi-block meshes. It essentially reduces the problem down to defining the surface mesh node derivatives with respect to the geometry parameters of interest. For analytical geometries, this is quite straightforward. In the more general case, one would need to be able to interrogate the underlying parametric CAD (computer aided design) model and to evaluate the derivatives either analytically, or by a finite difference technique. Because the technique is based on a partial differential equation (PDE), it is applicable not only to forward mode problems (where derivatives of all the output quantities are computed with respect to a single input), but it could also be extended to the adjoint problem, either by using an analytical adjoint of the PDE or a discrete analog.
Fellinger, Michael R.; Hector, Jr., Louis G.; Trinkle, Dallas R.
2016-11-29
Here, we present computed datasets on changes in the lattice parameter and elastic stiffness coefficients of BCC Fe due to substitutional Al, B, Cu, Mn, and Si solutes, and octahedral interstitial C and N solutes. The data is calculated using the methodology based on density functional theory (DFT). All the DFT calculations were performed using the Vienna Ab initio Simulations Package (VASP). The data is stored in the NIST dSpace repository.
Petillion, Saskia; Swinnen, Ans; Defraene, Gilles; Verhoeven, Karolien; Weltens, Caroline; Van den Heuvel, Frank
2014-07-08
The comparison of the pencil beam dose calculation algorithm with modified Batho heterogeneity correction (PBC-MB) and the analytical anisotropic algorithm (AAA) and the mutual comparison of advanced dose calculation algorithms used in breast radiotherapy have focused on the differences between the physical dose distributions. Studies on the radiobiological impact of the algorithm (both on the tumor control and the moderate breast fibrosis prediction) are lacking. We, therefore, investigated the radiobiological impact of the dose calculation algorithm in whole breast radiotherapy. The clinical dose distributions of 30 breast cancer patients, calculated with PBC-MB, were recalculated with fixed monitor units using more advanced algorithms: AAA and Acuros XB. For the latter, both dose reporting modes were used (i.e., dose-to-medium and dose-to-water). Next, the tumor control probability (TCP) and the normal tissue complication probability (NTCP) of each dose distribution were calculated with the Poisson model and with the relative seriality model, respectively. The endpoint for the NTCP calculation was moderate breast fibrosis five years post treatment. The differences were checked for significance with the paired t-test. The more advanced algorithms predicted a significantly lower TCP and NTCP of moderate breast fibrosis then found during the corresponding clinical follow-up study based on PBC calculations. The differences varied between 1% and 2.1% for the TCP and between 2.9% and 5.5% for the NTCP of moderate breast fibrosis. The significant differences were eliminated by determination of algorithm-specific model parameters using least square fitting. Application of the new parameters on a second group of 30 breast cancer patients proved their appropriateness. In this study, we assessed the impact of the dose calculation algorithms used in whole breast radiotherapy on the parameters of the radiobiological models. The radiobiological impact was eliminated by
NASA Technical Reports Server (NTRS)
Pai, Shantaram S.; Gyekenyesi, John P.
1988-01-01
The calculation of shape and scale parameters of the two-parameter Weibull distribution is described using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. Detailed procedures are given for evaluating 90 percent confidence intervals for maximum likelihood estimates of shape and scale parameters, the unbiased estimates of the shape parameters, and the Weibull mean values and corresponding standard deviations. Furthermore, the necessary steps are described for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull distribution. It also shows how to calculate the Batdorf flaw-density constants by uing the Weibull distribution statistical parameters. The techniques described were verified with several example problems, from the open literature, and were coded. The techniques described were verified with several example problems from the open literature, and were coded in the Structural Ceramics Analysis and Reliability Evaluation (SCARE) design program.
Strategy and calculations for the design of baffles for Wolter Type II telescopes
NASA Technical Reports Server (NTRS)
Mangus, John D.
1988-01-01
Spaceflight, stellar pointing telescopes require baffle systems to define the field of view and protect this observational area from stray and scattered light. In the case of near normal incidence telescope systems, the problem consists in controlling the stray/scattered radiation reaching the image plane when circular plates, the primary and secondary mirrors, are the imaging elements. The case addressed in this paper is quite different in that it involves baffling two conical surfaces, i.e., the primary and secondary mirrors of a Wolter Type II telescope. A strategy is described for systematically moving through the telescope system and establishing criteria for placement of baffles. Calculations are given which determine the size and number of permitted baffles as a function of practical physical parameters. Clear options are given for the design of minimum baffle lengths to meet packaging constraints.
USDA-ARS?s Scientific Manuscript database
Traditionally, a two-parameter partial differential equation has been used to describe the one-dimensional convective-dispersive transport of chemicals in field soils. The parameters in this equation include the dispersion coefficient and a distribution coefficient, the latter accounting for interac...
Numerical Procedures for the Calculations of Inorganic Solubility and Cohesive Parameters
NASA Technical Reports Server (NTRS)
Lawson, D.
1996-01-01
The entire history of chemistry bears witness to the extraorinary importance of the phenomena of solubility. It is necessary to emphasize that the Hildebrand parameter (solubility parameter) is fundamentally a liquid state property. When gases are considered they are treated as hypothetical.
Moustafa, Nagy Emam; Eissa, Elham Ahmed
2007-11-01
The Flory-Huggins interaction parameter (chi1, 2(infinity)) and solubility parameter (delta2) and its hydrogen bonding sensing component (delta(h)) were determined using inverse gas chromatography (IGC). These parameters were successfully used in the probes of chemical changes that occur during the oxidation of naphthenic and paraffinic base oils in a GC column. Changes in chi1, 2(infinity) values reflect the different types of intermolecular interactions (dispersive, polar, hydrogen bonding) of the given lubricating base oil during oxidation. The obtained results showed that delta(h) component of solubility parameter is the most important parameter for probing the oxidative-chemical changes during the oxidation of given lubricating oils.
Parametric design calculations using Green's function to determine unique source
NASA Astrophysics Data System (ADS)
Carter, L. L.; Lan, J. S.
1991-01-01
The energy dependence of the current incident on a macrocell can in principle be determined if the Green's function and the interior flux due to the total current are known. The Green's function is the flux within some portion of the macrocell due to a unit source in each energy group. It was demonstrated that the appropriate solution for the current is obtained for the higher energy groups in a fast reactor example. However, the lower energy groups are very sensitive to the downscattering and the solution even led to negative values for the incident partial current in some energy groups, which is not physical. In this particular example, the preliminary design study was insensitive to the incident current of the lower energy groups. For problems where the lower groups are important, it would seem prudent to abandon the exact solution and use a weighted least squares solution. Such a weighted least squares solution could assign importance for obtaining nearly the exact solution for as many energy groups as possible, while simultaneously making slight adjustments in the higher energy currents to obtain downscatter contributions that will approximately perserve the flux in the lower energy groups.
Kreutzfeldt, C
1980-10-01
A calculation program is proposed suitable for programmable pocket calculators (e.g. HP series) to estimate s20,w f omega2 dt values from density gradient centrifugation data. The program can be applied to linear or exponential density gradients prepared from sucrose or glycerol solutions spun in zonal rotors or swinging bucket rotors. A wide solute concentration range and temperature range is accounted for. Constants for empirical density calculation of glycerol and sucrose solutions concentrated in % (w/v) are estimated. Experimental verification of the program was carried out.
Borodkin, P.G.; Borodkin, G.I.; Khrennikov, N.N.
2011-07-01
The approach of improved uncertainty-accounted conservative evaluation of vodo-vodyanoi energetichesky reactor (VVER) (reactor-) pressure-vessel (RPV) radiation loading parameters has been proposed. This approach is based on the calculational-experimental procedure, which takes into account C/E ratio, depending on over- or underestimation, and uncertainties of measured and calculated results. An application of elaborated approach to the full-scale ex-vessel neutron dosimetry experiments on Russian VVERs combined with neutron-transport calculations has been demonstrated in the paper. (authors)
Design and Study of the Instrument to Assess Students' Attitude toward Graphing Calculator
ERIC Educational Resources Information Center
Reznichenko, Nataliya
2007-01-01
Assumptions: In mathematics learning, one of the considerations in the graphing calculator (GC) use is to understand students' attitude toward calculators. Rationale: This presentation describes design of an assessment instrument of students' attitude toward graphing calculator. Objectives: A pilot study that assessed the effectiveness of the…
Probabilistic seismic hazard characterization and design parameters for the Pantex Plant
Bernreuter, D. L.; Foxall, W.; Savy, J. B.
1998-10-19
The Hazards Mitigation Center at Lawrence Livermore National Laboratory (LLNL) updated the seismic hazard and design parameters at the Pantex Plant. The probabilistic seismic hazard (PSH) estimates were first updated using the latest available data and knowledge from LLNL (1993, 1998), Frankel et al. (1996), and other relevant recent studies from several consulting companies. Special attention was given to account for the local seismicity and for the system of potentially active faults associated with the Amarillo-Wichita uplift. Aleatory (random) uncertainty was estimated from the available data and the epistemic (knowledge) uncertainty was taken from results of similar studies. Special attention was given to soil amplification factors for the site. Horizontal Peak Ground Acceleration (PGA) and 5% damped uniform hazard spectra were calculated for six return periods (100 yr., 500 yr., 1000 yr., 2000 yr., 10,000 yr., and 100,000 yr.). The design parameters were calculated following DOE standards (DOE-STD-1022 to 1024). Response spectra for design or evaluation of Performance Category 1 through 4 structures, systems, and components are presented.
Relativistic Calculating the Spectral Lines Hyperfine Structure Parameters for Heavy Ions
Khetselius, O. Yu.
2008-10-22
The energies and constants of the hyperfine structure, derivatives of the one-electron characteristics on nuclear radius, nuclear electric quadrupole, magnetic dipole moments for some Li-like multicharged ions are calculated.
NASA Technical Reports Server (NTRS)
Seidel, R. C.; Lehtinen, B.
1974-01-01
A technique is described for designing feedback control systems using frequency domain models, a quadratic cost function, and a parameter optimization computer program. FORTRAN listings for the computer program are included. The approach is applied to the design of shock position controllers for a supersonic inlet. Deterministic or random system disturbances, and the presence of random measurement noise are considered. The cost function minimization is formulated in the time domain, but the problem solution is obtained using a frequency domain system description. A scaled and constrained conjugate gradient algorithm is used for the minimization. The approach to a supersonic inlet included the calculations of the optimal proportional-plus integral (PI) and proportional-plus-integral-plus-derivative controllers. A single-loop PI controller was the most desirable of the designs considered.
NASA Technical Reports Server (NTRS)
Lorenz-Meyer, W.
1977-01-01
In connection with the question on the applicability of test results obtained from cryogenic wind tunnels to the large-scale model the similarity parameter is referred to. A simple method is given for calculating the similarity parameter. From the numerical values obtained it can be deduced that nitrogen behaves practically like an ideal gas when it is close to the saturation point and in a pressure range up to 4 bar. The influence of this parameter on the pressure distribution of a supercritical profile confirms this finding.
Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion
Brown N. R.; Brown,N.R.; Baek,J.S; Hanson, A.L.; Cuadra,A.; Cheng,L.Y.; Diamond, D.J.
2013-03-31
It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. . The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). In addition, a summary of the methodology to obtain these results is presented.
Design Parameter Studies of Emission-Based Iron Opacity Measurements
NASA Astrophysics Data System (ADS)
Martin, Madison E.; London, Richard A.; Goluoglu, Sedat; Whitley, Heather D.
2016-10-01
Opacity is a critical parameter in the transport of radiation in systems such as inertial confinement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would benefit from experimental validation of theoretical opacity models. Short pulse lasers can be used to heat targets to higher temperatures and densities than long pulse lasers and pulsed power machines, thus potentially enabling access to x-ray emission spectra at conditions relevant to solar models. The radiation-hydrodynamic code HYDRA is used to investigate the effects of modifying laser energy, laser pulse length, and target dimensions on the plasma conditions, x-ray emission, and inferred opacity of a buried layer iron target. The accuracy of the opacity inference is sensitive to tamper emission and optical depth effects. An example design that reaches temperatures and densities relevant to the radiative zone of the sun while reducing optical depth and tamper emission effects will be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.
Irradiation Experiment Conceptual Design Parameters for NBSR Fuel Conversion
Brown, N. R.; Brown, N. R.; Baek, J. S; Hanson, A. L.; Cuadra, A.; Cheng, L. Y.; Diamond, D. J.
2014-04-30
It has been proposed to convert the National Institute of Standards and Technology (NIST) research reactor, known as the NBSR, from high-enriched uranium (HEU) fuel to low-Enriched uranium (LEU) fuel. The motivation to convert the NBSR to LEU fuel is to reduce the risk of proliferation of special nuclear material. This report is a compilation of relevant information from recent studies related to the proposed conversion using a metal alloy of LEU with 10 w/o molybdenum. The objective is to inform the design of the mini-plate and full-size-Plate irradiation experiments that are being planned. This report provides relevant dimensions of the fuel elements, and the following parameters at steady state: average and maximum fission rate density and fission density, fuel temperature distribution for the plate with maximum local temperature, and two-dimensional heat flux profiles of fuel plates with high power densities. The latter profiles are given for plates in both the inner and outer core zones and for cores with both fresh and depleted shim arms (reactivity control devices). A summary of the methodology to obtain these results is presented. Fuel element tolerance assumptions and hot channel factors used in the safety analysis are also given.
Frequency response and design parameters for differential microbarometers.
Mentink, Johan H; Evers, Läslo G
2011-07-01
The study of infrasound is experiencing a renaissance since it was chosen as a verification technique for the Comprehensive Nuclear-Test-Ban Treaty. Source identification is one of the main topics of research which involves detailed knowledge on the source time function, the atmosphere as medium of propagation, and the measurement system. Applications are also foreseen in using infrasound as passive probe for the upper atmosphere, taking the field beyond its monitoring application. Infrasound can be conveniently measured with differential microbarometers. An accurate description of the instrument response is an essential need to be able to attribute the recorded infrasound to a certain source or atmospheric properties. In this article, a detailed treatment is given of the response of a differential microbarometer to acoustic signals. After an historical introduction, a basic model for the frequency response is derived with its corresponding poles and zeros. The results are explained using electric analogs. In addition, thermal conduction is added to the model in order to capture the transition between adiabatic and isothermal behavior. Also discussed are high-frequency effects and the effect of external temperature variations. Eventually, the design parameters for differential microbarometers are derived. © 2011 Acoustical Society of America
Design Parameters of a Miniaturized Piezoelectric Underwater Acoustic Transmitter
Li, Huidong; Deng, Zhiqun; Yuan, Yong; Carlson, Thomas J.
2012-07-02
The Juvenile Salmon Acoustic Telemetry System (JSATS) project supported by the U.S. Army Corps of Engineers, Portland District, has yielded the smallest acoustic fish tag transmitter commercially available to date. In order to study even smaller fish populations and make the transmitter injectable by needles, the JSATS acoustic micro transmitter needs to be further downsized. As part of the transmitter downsizing effort some of the design parameters of the lead zirconate titanate (PZT) ceramic tube transducer in the transmitter were studied, including the type of PZT, the backing material, the necessary drive voltage, the transmitting bandwidth and the length of the transducer. It was found that, to satisfy the 156-dB source level requirement of JSATS, a square wave with a 10-volt amplitude is required to drive 'soft' PZT transducers. PZT-5H demonstrated the best source level performance. For Navy types I and II, 16 volts or 18 volts were needed. Ethylene-propylene-diene monomer (EPDM) closed-cell foam was found to be the backing material providing the highest source level. The effect of tube length on the source level is also demonstrated in this paper, providing quantitative information for downsizing of small piezoelectric transmitters.
Zhu, Hongchun; Cai, Lijie; Liu, Haiying; Huang, Wei
2016-01-01
Multi-scale image segmentation and the selection of optimal segmentation parameters are the key processes in the object-oriented information extraction of high-resolution remote sensing images. The accuracy of remote sensing special subject information depends on this extraction. On the basis of WorldView-2 high-resolution data, the optimal segmentation parameters methodof object-oriented image segmentation and high-resolution image information extraction, the following processes were conducted in this study. Firstly, the best combination of the bands and weights was determined for the information extraction of high-resolution remote sensing image. An improved weighted mean-variance method was proposed andused to calculatethe optimal segmentation scale. Thereafter, the best shape factor parameter and compact factor parameters were computed with the use of the control variables and the combination of the heterogeneity and homogeneity indexes. Different types of image segmentation parameters were obtained according to the surface features. The high-resolution remote sensing images were multi-scale segmented with the optimal segmentation parameters. Ahierarchical network structure was established by setting the information extraction rules to achieve object-oriented information extraction. This study presents an effective and practical method that can explain expert input judgment by reproducible quantitative measurements. Furthermore the results of this procedure may be incorporated into a classification scheme.
Zhu, Hongchun; Cai, Lijie; Liu, Haiying; Huang, Wei
2016-01-01
Multi-scale image segmentation and the selection of optimal segmentation parameters are the key processes in the object-oriented information extraction of high-resolution remote sensing images. The accuracy of remote sensing special subject information depends on this extraction. On the basis of WorldView-2 high-resolution data, the optimal segmentation parameters methodof object-oriented image segmentation and high-resolution image information extraction, the following processes were conducted in this study. Firstly, the best combination of the bands and weights was determined for the information extraction of high-resolution remote sensing image. An improved weighted mean-variance method was proposed andused to calculatethe optimal segmentation scale. Thereafter, the best shape factor parameter and compact factor parameters were computed with the use of the control variables and the combination of the heterogeneity and homogeneity indexes. Different types of image segmentation parameters were obtained according to the surface features. The high-resolution remote sensing images were multi-scale segmented with the optimal segmentation parameters. Ahierarchical network structure was established by setting the information extraction rules to achieve object-oriented information extraction. This study presents an effective and practical method that can explain expert input judgment by reproducible quantitative measurements. Furthermore the results of this procedure may be incorporated into a classification scheme. PMID:27362762
Jet pumps for thermoacoustic applications: Design guidelines based on a numerical parameter study.
Oosterhuis, Joris P; Bühler, Simon; Wilcox, Douglas; van der Meer, Theo H
2015-10-01
The oscillatory flow through tapered cylindrical tube sections (jet pumps) is characterized by a numerical parameter study. The shape of a jet pump results in asymmetric hydrodynamic end effects which cause a time-averaged pressure drop to occur under oscillatory flow conditions. Hence, jet pumps are used as streaming suppressors in closed-loop thermoacoustic devices. A two-dimensional axisymmetric computational fluid dynamics model is used to calculate the performance of a large number of conical jet pump geometries in terms of time-averaged pressure drop and acoustic power dissipation. The investigated geometrical parameters include the jet pump length, taper angle, waist diameter, and waist curvature. In correspondence with previous work, four flow regimes are observed which characterize the jet pump performance and dimensionless parameters are introduced to scale the performance of the various jet pump geometries. The simulation results are compared to an existing quasi-steady theory and it is shown that this theory is only applicable in a small operation region. Based on the scaling parameters, an optimum operation region is defined and design guidelines are proposed which can be directly used for future jet pump design.
NASA Astrophysics Data System (ADS)
Okuducu, Ş.; Akti, N. N.; Saraç, H.; Bölükdemir, M. H.; Tel, E.
In this study the nuclear energy level density based on nuclear collective excitation mechanism has been identified in terms of the low-lying collective level bands near the neutron binding energy. Nuclear level density parameters of some light deformed medical radionuclides used widely in medical applications have been calculated by using different collective excitation modes of observed nuclear spectra. The calculated parameters have been used successfully in estimation of the neutron-capture cross section basic data for the production of new medical radionuclides. The investigated radionuclides have been considered in the region of mass number 40calculated results have been compared with the compiled values from the literatures for s-wave neutron resonance data.
Calculation of the structural parameters of small cadmium selenide clusters, (CdSe)n, n = 1,2,3
NASA Astrophysics Data System (ADS)
Alselawe, A. I. A.; Gopir, G.; Anas, M. M.
2016-11-01
The structural parameters of small cadmium selenide clusters (CdSe)n, for n=1,2, and 3 were studied. The calculations were performed using the pseudopotential and planewave basis sets, within the density functional theory. These parameters for geometry optimization can be used as elementary information for further investigations. The total energy calculations for the three linear structures of (CdSe)2 showed that these isomers are close in their stability. The rhombus structure (CdSe)2 planar is more stable isomer. The bond distances for the different structures show that the distances decrease with increasing the atoms in the structure. The calculated bond angles were close to other relevant studies.
DFT Calculations on Mössbauer Parameters of Nonheme Iron Nitrosyls
Hopmann, Kathrin H.; Ghosh, Abhik; Noodleman, Louis
2009-01-01
DFT calculations on transition metal nitrosyls often reveal unusual spin density profiles, involving substantial spatial separation of majority and minority spin densities. Against this context, there is a significant lack of studies where DFT calculations have been quantitatively calibrated against experimental spectroscopic properties. Reported herein are DFT calculations of Mössbauer isomer shifts and quadrupole splittings for 21 nonheme iron complexes (26 distinct iron sites) including 9 iron nitrosyls. Low- (S = 1/2) and high-spin (S = 3/2) {FeNO}7 complexes, S = 1/2 {Fe(NO)2}9 species, and polynuclear iron nitrosyls are all represented within the set of compounds examined. The general conclusion with respect to isomer shifts is that DFT (OLYP/STO-TZP) performs comparably well for iron nitrosyls and for iron complexes in general. However, quadrupole splittings are less accurately reproduced for nitrosyl complexes. PMID:19780615
On the Methodology to Calculate the Covariance of Estimated Resonance Parameters
Becker, B.; Kopecky, S.; Schillebeeckx, P.
2015-01-15
Principles to determine resonance parameters and their covariance from experimental data are discussed. Different methods to propagate the covariance of experimental parameters are compared. A full Bayesian statistical analysis reveals that the level to which the initial uncertainty of the experimental parameters propagates, strongly depends on the experimental conditions. For high precision data the initial uncertainties of experimental parameters, like a normalization factor, has almost no impact on the covariance of the parameters in case of thick sample measurements and conventional uncertainty propagation or full Bayesian analysis. The covariances derived from a full Bayesian analysis and least-squares fit are derived under the condition that the model describing the experimental observables is perfect. When the quality of the model can not be verified a more conservative method based on a renormalization of the covariance matrix is recommended to propagate fully the uncertainty of experimental systematic effects. Finally, neutron resonance transmission analysis is proposed as an accurate method to validate evaluated data libraries in the resolved resonance region.
NASA Astrophysics Data System (ADS)
Svinarenko, A. A.; Ignatenko, A. V.; Ternovsky, V. B.; Nikola, V. V.; Seredenko, S. S.; Tkach, T. B.
2014-11-01
The combined relativistic energy approach and relativistic many-body perturbation theory with the zeroth order optimized one-particle approximation are used for calculation of the Li-like ions (Z=11-42,69,70) energies and oscillator strengths of radiative transitions from the ground state to the low-excited and Rydberg states, in particular, 2s1/2 - np1/2,3/2, np1/2,3/2- nd3/2,5/2 (n=2-12). A comparison of the calculated oscillator strengths with available theoretical and experimental data is performed.
NASA Astrophysics Data System (ADS)
Ganyushin, Dmitry; Gilka, Natalie; Taylor, Peter R.; Marian, Christel M.; Neese, Frank
2010-04-01
In this work, the resolution of the identity (RI) approximation is developed for the calculation of the electron-electron spin-spin coupling (SSC) interaction that is a central component of the zero-field splitting (ZFS) term in the effective spin Hamiltonian. The approximated integrals are then used in large-scale multireference configuration interaction treatments of the SSC interaction. The SSC contribution to the ZFS is treated using the Breit-Pauli spin-spin Hamiltonian in conjunction with first-order perturbation theory. Test calculations on a set of diatomic molecules reveal that the error of the RI approximation does not exceed 0.01 cm-1 even if standard auxiliary basis sets are used. This error of less than 1% is considered to be negligible compared to the presently achievable accuracy of the SSC calculations relative to experimental data. The present development allows the correlated ab initio calculation of ZFS parameters of larger systems such as linear polyenes and linear polyacenes. The basis set convergence of the calculated ZFS values was investigated, and the effect of electronic correlation on the calculated ZFS parameters is discussed.
Hulland, Erin N; Blanton, Curtis J; Leidman, Eva Z; Bilukha, Oleg O
2016-01-01
Cluster surveys provide rapid but representative estimates of key nutrition indicators in humanitarian crises. For these surveys, an accurate estimate of the design effect is critical to calculate a sample size that achieves adequate precision with the minimum number of sampling units. This paper describes the variability in design effect for three key nutrition indicators measured in small-scale surveys and models the association of design effect with parameters hypothesized to explain this variability. 380 small-scale surveys from 28 countries conducted between 2006 and 2013 were analyzed. We calculated prevalence and design effect of wasting, underweight, and stunting for each survey as well as standard deviations of the underlying continuous Z-score distribution. Mean cluster size, survey location and year were recorded. To describe design effects, median and interquartile ranges were examined. Generalized linear regression models were run to identify potential predictors of design effect. Median design effect was under 2.00 for all three indicators; for wasting, the median was 1.35, the lowest among the indicators. Multivariable linear regression models suggest significant, positive associations of design effect and mean cluster size for all three indicators, and with prevalence of wasting and underweight, but not stunting. Standard deviation was positively associated with design effect for wasting but negatively associated for stunting. Survey region was significant in all three models. This study supports the current field survey guidance recommending the use of 1.5 as a benchmark for design effect of wasting, but suggests this value may not be large enough for surveys with a primary objective of measuring stunting or underweight. The strong relationship between design effect and region in the models underscores the continued need to consider country- and locality-specific estimates when designing surveys. These models also provide empirical evidence of a
Calculations of the heights, periods, profile parameters, and energy spectra of wind waves
NASA Technical Reports Server (NTRS)
Korneva, L. A.
1975-01-01
Sea wave behavior calculations require the precalculation of wave elements as well as consideration of the spectral functions of ocean wave formation. The spectrum of the random wave process is largely determined by the distribution of energy in the actual wind waves observed on the surface of the sea as expressed in statistical and spectral characteristics of the sea swell.
Calculations of the heights, periods, profile parameters, and energy spectra of wind waves
NASA Technical Reports Server (NTRS)
Korneva, L. A.
1975-01-01
Sea wave behavior calculations require the precalculation of wave elements as well as consideration of the spectral functions of ocean wave formation. The spectrum of the random wave process is largely determined by the distribution of energy in the actual wind waves observed on the surface of the sea as expressed in statistical and spectral characteristics of the sea swell.
NASA Astrophysics Data System (ADS)
Bagaev, S. N.; Dmitriev, A. K.; Lugovoy, A. A.
2008-01-01
A method is proposed to stabilise the frequency of a He—Ne laser with an intracavity nonlinear absorption cell by the calculated frequency of the 7→6 transition of F2(2)P(7)ν3 in methane. The long-term frequency stability and reproducibility are measured for a He—Ne/CH4 laser with a telescopic cavity.
NASA Astrophysics Data System (ADS)
Yadav, Jayprakash; Rafique, S. M.; Kumari, Shanti
2009-10-01
In the present paper some superconducting (SC) state parameters of metals Ga, Cd and In have been studied through Harrison's First Principle [HFP] pseudopotential technique using McMillan's formalism. The impact of choosing two different sets of core energy eigenvalues viz. Herman-Skillman and Clementi (or Experimental) has been studied.
Universal algorithms and programs for calculating the motion parameters in the two-body problem
NASA Technical Reports Server (NTRS)
Bakhshiyan, B. T.; Sukhanov, A. A.
1979-01-01
The algorithms and FORTRAN programs for computing positions and velocities, orbital elements and first and second partial derivatives in the two-body problem are presented. The algorithms are applicable for any value of eccentricity and are convenient for computing various navigation parameters.
Winter, Samantha Lee; Forrest, Sarah Michelle; Wallace, Joanne; Challis, John H
2017-08-08
The purpose of this study was to validate a new geometric solids model, developed to address the lack of female specific models for body segment inertial parameter estimation. A second aim was to determine the effect of reducing the number of geometric solids used to model the limb segments on model accuracy. The 'full' model comprised 56 geometric solids, the 'reduced' 31, and the 'basic' 16. Predicted whole-body inertial parameters were compared with direct measurements (reaction board, scales), and predicted segmental parameters with those estimated from whole-body DXA scans for 28 females. The percentage root mean square error (%RMSE) for whole-body volume was <2.5% for all models, and 1.9% for the full model. The %RMSE for whole-body center of mass location was <3.2% for all models. The %RMSE whole-body mass was <3.3% for the full model. The RMSE for segment masses was <0.5 kg (<0.5%) for all segments; Bland-Altman analysis showed the full and reduced models could adequately model thigh, forearm, foot and hand segments, but the full model was required for the trunk segment. The proposed model was able to accurately predict body segment inertial parameters for females, more geometric solids are required to more accurately model the trunk.
Dosimetric parameters of the new design (103)Pd brachytherapy source based on Monte Carlo study.
Saidi, Pooneh; Sadeghi, Mahdi; Shirazi, Alireza; Tenreiro, Claudio
2012-01-01
In this study version 5 of the MCNP photon transport simulation was used to calculate the dosimetric parameters for new palladium brachytherapy source design following AAPM Task Group No. 43U1 report. The internal source components include four resin beads of 0.6 mm diameters with (103)Pd uniformly absorbed inside and one cylindrical copper marker with 1.5 mm length. The resin beads and marker are then encapsulated within 0.8 mm in diameter and 4.5 mm long cylindrical capsule of titanium. The dose rate constant, Λ, line and point-source radial dose function, g(L)(r) and g(P)(r), and the anisotropy function, F(r,θ) of the IR01-(103)Pd seed have been calculated at distances from 0.25 to 5 cm. All the results are in good agreement with previously published thermoluminescence-dosimeter measured values [3] for the source. The dosimetric parameters calculated in this work showed that in dosimetry point of view, the IR01-(103)Pd seed is suitable for use in brachytherapy of prostate cancer.
Sensitivity analysis of a dry-processed Candu fuel pellet's design parameters
Choi, Hangbok; Ryu, Ho Jin
2007-07-01
Sensitivity analysis was carried out in order to investigate the effect of a fuel pellet's design parameters on the performance of a dry-processed Canada deuterium uranium (CANDU) fuel and to suggest the optimum design modifications. Under a normal operating condition, a dry-processed fuel has a higher internal pressure and plastic strain due to a higher fuel centerline temperature when compared with a standard natural uranium CANDU fuel. Under a condition that the fuel bundle dimensions do not change, sensitivity calculations were performed on a fuel's design parameters such as the axial gap, dish depth, gap clearance and plenum volume. The results showed that the internal pressure and plastic strain of the cladding were most effectively reduced if a fuel's element plenum volume was increased. More specifically, the internal pressure and plastic strain of the dry-processed fuel satisfied the design limits of a standard CANDU fuel when the plenum volume was increased by one half a pellet, 0.5 mm{sup 3}/K. (authors)
SAMPLE SIZE/POWER CALCULATION FOR STRATIFIED CASE-COHORT DESIGN
Hu, Wenrong; Cai, Jianwen; Zeng, Donglin
2014-01-01
The Case-cohort (CC) study design usually has been used for risk factor assessment in epidemiologic studies or disease prevention trials for rare diseases. The sample size/power calculation for the CC design is given in Cai and Zeng [1]. However, the sample size/power calculation for a stratified case-cohort (SCC) design has not been addressed before. This article extends the results of Cai and Zeng [1] to the SCC design. Simulation studies show that the proposed test for the SCC design utilizing small sub-cohort sampling fractions is valid and efficient for situations where the disease rate is low. Furthermore, optimization of sampling in the SCC design is discussed and compared with proportional and balanced sampling techniques. An epidemiological study is provided to illustrate the sample size calculation under the SCC design. PMID:24889145
[Design of high performance DSP-based gradient calculation module for MRI].
Pan, Wenyu; Zhang, Fu; Luo, Hai; Zhou, Heqin
2011-05-01
A gradient calculation module based on high performance DSP was designed to meet the needs of digital MRI spectrometer. According to the requirements of users, this apparatus can achieve rotation transformation, pre-emphasis, shimming and other gradient calculation functions in a single chip of DSP. It then outputs gradient waveform data of channel X, Y, Z and shimming data of channel B0. Experiments show that the design has good versatility and can satisfy the functional, speed and accuracy requirements of MRI gradient calculation. It provides a practical gradient calculation solution for the development of digital spectrometer.
Campos, Luis M; Dang, Hung; Ng, Danny; Yang, Zhe; Martinez, Hernan L; Garcia-Garibay, Miguel A
2002-05-31
A detailed thermochemical analysis of the alpha-cleavage and decarbonylation reactions of acetone and several ketodiesters was carried out with the B3LYP/6-31G* density functional method. The heats of formation of several ground-state ketones and radicals were calculated at 298 K to determine bond dissociation energies (BDE) and radical stabilization energies (RSE) as a function of substituents. Results show that the radical-stabilizing abilities of the ketone substituents play a very important role on the thermodynamics of the alpha-cleavage and decarbonylation steps. An excellent correlation between calculated values and previous experimental observations suggests that photochemical alpha-cleavage and decarbonylation in crystals should be predictable from knowledge of excitation energies and the RSE of the substituent.
Rafiee, Marjan; Javaheri, Masoumeh
2015-09-01
Tyrosinase is a multifunctional copper-containing enzyme. It can catalyze two distinct reactions of melanin synthesis and benzaldehyde derivatives, which are potential tyrosinase inhibitors. To find the relationships between charge distributions of benzaldehyde and their pharmaceutical behavior, the present study aimed at investigating nuclear quadrupole coupling constants of quadrupolare nuclei in the functional benzaldehyde group and calculating some its derivatives. In addition, the differences between the electronic structures of various derivatives of this depigmenting drug were examined. All ab initio calculations were carried out using Gaussian 03. The results predicted benzaldehyde derivatives to be bicentral inhibitors; nevertheless, the oxygen or hydrogen contents of the aldehyde group were not found to be the only active sites. Furthermore with the presence of the aldehyde group, the terminal methoxy group in C4 was found to contribute to tyrosinase inhibitory activities. In addition, an oxygen atom with high charge density in the side chain was found to play an important role in its inhibitory effect.
Schade, F; Arampatzis, A; Brüggemann, G
2000-10-01
The purposes of this study were as follows: (1) To determine the differences between two- and three-dimensionally calculated energy of the athlete in the pole vault. (2) To determine the differences between CM energy and total body energy. (3) To examine the influence of these different approaches of calculating the athlete's energy on energetic parameter values during the pole vault. Kinematic data were gathered during the pole vault final of the track and field world championships in 1997. Two video cameras (50Hz) covered the last step of the approach including the pole plant and 2 cameras covered the pole phase up to bar clearance, respectively. Twenty successful jumps were analysed. The characteristics of the energy development is similar for the different approaches. Initial energy, energy at maximum pole bend and energy at pole release (primary parameters) show significant differences (p<0.05). The findings indicate that rotatory movements and movements relative to the CM have a larger influence on the primary parameters than movements apart from the main plane of movement. For analysing the energy exchange between the athlete and the elastic implement pole only the differences among the secondary parameters (initial energy minus energy at maximum pole bend, final energy minus energy at maximum pole bend) are needed (Arampatzis et al., 1997 Biomechanical Research Project at the Vth World Championships in Athletics, Athens 1997: Preliminary Report. New Studies in Athletics 13, 66-69). For those parameters the relative differences between the calculation approaches range only between 1.47 and 0.04%. This indicates that the influence of the different approaches for calculating the athlete's energy on the analysis of energy exchange is negligible.
Methods and new approaches to the calculation of physiological parameters by videodensitometry
NASA Technical Reports Server (NTRS)
Kedem, D.; Londstrom, D. P.; Rhea, T. C., Jr.; Nelson, J. H.; Price, R. R.; Smith, C. W.; Graham, T. P., Jr.; Brill, A. B.; Kedem, D.
1976-01-01
A complex system featuring a video-camera connected to a video disk, cine (medical motion picture) camera and PDP-9 computer with various input/output facilities has been developed. This system enables the performance of quantitative analysis of various functions recorded in clinical studies. Several studies are described, such as heart chamber volume calculations, left ventricle ejection fraction, blood flow through the lungs and also the possibility of obtaining information about blood flow and constrictions in small cross-section vessels
Methods and new approaches to the calculation of physiological parameters by videodensitometry
NASA Technical Reports Server (NTRS)
Kedem, D.; Londstrom, D. P.; Rhea, T. C., Jr.; Nelson, J. H.; Price, R. R.; Smith, C. W.; Graham, T. P., Jr.; Brill, A. B.; Kedem, D.
1976-01-01
A complex system featuring a video-camera connected to a video disk, cine (medical motion picture) camera and PDP-9 computer with various input/output facilities has been developed. This system enables the performance of quantitative analysis of various functions recorded in clinical studies. Several studies are described, such as heart chamber volume calculations, left ventricle ejection fraction, blood flow through the lungs and also the possibility of obtaining information about blood flow and constrictions in small cross-section vessels
Comparison of ionospheric parameters calculated with UAM and measured at Voeykovo observatory
NASA Astrophysics Data System (ADS)
Rybakov, M. V.; Namgaladze, A. A.; Karpov, M. I.
2016-09-01
The measurements of the critical frequencies of the ionospheric F2 layer based on vertical radiosounding, which was performed with a CADI digital ionosonde at the Voeykovo magnetic-ionospheric observatory in February 2013, have been considered. The observations have been compared with the upper atmosphere numerical model (UAM) data for three days that differ in the amplitude and the character of solar and magnetic activity and correspond to quiet and moderately disturbed states of the ionosphere. The work was performed in order to improve the methods for determining the ionospheric state by vertical sounding ionograms. The time variations in the F2 layer critical frequency, electric field vector zonal component, and thermospheric wind velocity meridional component have been analyzed. Calculations were performed with three UAM variants. The UAM version providing the best agreement with the CADI ionosonde data was the version in which the neutral temperature, neutral composition, and pressure gradients are calculated according to the MSIS empirical model and the horizontal neutral wind velocity is determined by the equation of motion with pressure gradients from MSIS. The calculated values corresponded to the measurements, except those for the evening, because the electron density at the ionospheric F2 layer maximum depends more strongly on electric fields and thermospheric wind velocities during this period. Thus, the indicated UAM version with the above limitations can be used to determine the state of the subauroral ionosphere.
Sadeghi, Mahdi; Raisali, Gholamreza; Hosseini, S Hamed; Shavar, Arzhang
2008-04-01
This article presents a brachytherapy source having 103Pd adsorbed onto a cylindrical silver rod that has been developed by the Agricultural, Medical, and Industrial Research School for permanent implant applications. Dosimetric characteristics (radial dose function, anisotropy function, and anisotropy factor) of this source were experimentally and theoretically determined in terms of the updated AAPM Task group 43 (TG-43U1) recommendations. Monte Carlo simulations were used to calculate the dose rate constant. Measurements were performed using TLD-GR200A circular chip dosimeters using standard methods employing thermoluminescent dosimeters in a Perspex phantom. Precision machined bores in the phantom located the dosimeters and the source in a reproducible fixed geometry, providing for transverse-axis and angular dose profiles over a range of distances from 0.5 to 5 cm. The Monte Carlo N-particle (MCNP) code, version 4C simulation techniques have been used to evaluate the dose-rate distributions around this model 103Pd source in water and Perspex phantoms. The Monte Carlo calculated dose rate constant of the IRA-103Pd source in water was found to be 0.678 cGy h(-1) U(-1) with an approximate uncertainty of +/-0.1%. The anisotropy function, F(r, theta), and the radial dose function, g(r), of the IRA- 103Pd source were also measured in a Perspex phantom and calculated in both Perspex and liquid water phantoms.
NASA Technical Reports Server (NTRS)
Mccluney, W. R.
1974-01-01
The development is considered of procedures for measuring a number of subsurface oceanographic parameters using remotely sensed ocean color data. It is proposed that the first step in this effort should be the development of adequate theoretical models relating the desired oceanographic parameters to the upwelling radiances to be observed. A portion of a contributory theoretical model is shown to be described by a modified single scattering approach based upon a simple treatment of multiple scattering. The resulting quasi-single scattering model can be used to predict the upwelling distribution of spectral radiance emerging from the sea. The shape of the radiance spectrum predicted by this model for clear ocean water shows encouraging agreement with measurments made at the edge of the Sargasso Sea off Cape Hatteras.
Ames, William M; Larsen, Sarah C
2009-05-01
Density functional theory (DFT) calculations of Cu(II) electron paramagnetic resonance (EPR) parameters for the octarepeat unit of the prion protein were conducted. Model complexes were constructed and optimized using the crystal structure of the octarepeat unit of the prion protein. Copper g and A tensors and nitrogen hyperfine and quadrupole coupling constants were calculated using DFT. Solvent effects were incorporated using the conductor-like screening model as well as through the inclusion of explicit water molecules. Calculations using the model with an additional axial water molecule added to the coordination sphere of the Cu(II) metal center give the best qualitative agreement for the copper g and A tensors. The S-band experimental EPR spectra were interpreted in light of the DFT calculations of the directly coordinated nitrogen hyperfine coupling constants which indicate that the three directly coordinated nitrogen atoms in the octarepeat unit are not equivalent. These results demonstrate that DFT calculations of EPR parameters can provide important insight with respect to the structural interpretation of experimental EPR data.
Design of nonlinear discrete-time controllers using a parameter space sampling procedure
NASA Technical Reports Server (NTRS)
Young, G. E.; Auslander, D. M.
1983-01-01
The design of nonlinear discrete-time controllers is investigated where the control algorithm assumes a special form. State-dependent control actions are obtained from tables whose values are the design parameters. A new design methodology capable of dealing with nonlinear systems containing parameter uncertainty is used to obtain the controller design. Various controller strategies are presented and illustrated through an example.
Improved streamflow recession parameter estimation with attention to calculation of - dQ/dt
NASA Astrophysics Data System (ADS)
Roques, Clément; Rupp, David E.; Selker, John S.
2017-10-01
The rate of streamflow recession can be used to assess storage-outflow properties of source aquifers. A common method of analyzing streamflow recession is to plot the time rate of change in streamflow Q as a function of Q in a log-log space. Theory predicts, for diagnostic recession regimes, a power law relationship - dQ/dt = aQb, where recession coefficients a and b are functions of the hydraulic and geometric properties of the aquifer and of boundary and initial conditions. Observational error reduces the accuracy of estimates of a and b with errors in estimating the time derivative of the late-time recession (-dQ/dt) being particularly sensitive to observational error. Here we propose a method to improve estimation of a and b with particular focus on the estimation of -dQ/dt. Compared to previously published methods we find greater robustness in estimates of -dQ/dt and recession parameters and less sensitivity to the methodological parameters employed. Previous methods result in up to 50 to 100% error when estimating the recession parameter b, while the proposed methodology produces errors below 5% in the cases analyzed.
NASA Astrophysics Data System (ADS)
Wahyudi, Eko Januari
2013-09-01
As advancing application of soft computation technique in oil and gas industry, Genetic Algorithm (GA) also shows contribution in geophysical inverse problems in order to achieve better results and efficiency in computational process. In this paper, I would like to show the progress of my work in inverse modeling of time-lapse gravity data uses value encoding with alphabet formulation. The alphabet formulation designed to provide solution of characterization positive density change (+Δρ) and negative density change (-Δρ) respect to reference value (0 gr/cc). The inversion that utilize discrete model parameter, computed with GA as optimization algorithm. The challenge working with GA is take long time computational process, so the step in designing GA in this paper described through evaluation on GA operators performance test. The performances of several combinations of GA operators (selection, crossover, mutation, and replacement) tested with synthetic model in single-layer reservoir. Analysis on sufficient number of samples shows combination of SUS-MPCO-QSA/G-ND as the most promising results. Quantitative solution with more confidence level to characterize sharp boundary of density change zones was conducted with average calculation of sufficient model samples.
Fellinger, Michael R; Hector, Louis G; Trinkle, Dallas R
2017-02-01
We present computed datasets on changes in the lattice parameter and elastic stiffness coefficients of bcc Fe due to substitutional Al, B, Cu, Mn, and Si solutes, and octahedral interstitial C and N solutes. The data is calculated using the methodology based on density functional theory (DFT) presented in Ref. (M.R. Fellinger, L.G. Hector Jr., D.R. Trinkle, 2017) [1]. All the DFT calculations were performed using the Vienna Ab initio Simulations Package (VASP) (G. Kresse, J. Furthmüller, 1996) [2]. The data is stored in the NIST dSpace repository (http://hdl.handle.net/11256/671).
Butcher, B.M.
1997-08-01
A summary of the input parameter values used in final predictions of closure and waste densification in the Waste Isolation Pilot Plant disposal room is presented, along with supporting references. These predictions are referred to as the final porosity surface data and will be used for WIPP performance calculations supporting the Compliance Certification Application to be submitted to the U.S. Environmental Protection Agency. The report includes tables and list all of the input parameter values, references citing their source, and in some cases references to more complete descriptions of considerations leading to the selection of values.
A design method for minimizing sensitivity to plant parameter variations
NASA Technical Reports Server (NTRS)
Hadass, Z.; Powell, J. D.
1974-01-01
A method is described for minimizing the sensitivity of multivariable systems to parameter variations. The variable parameters are considered as random variables and their effect is included in a quadratic performance index. The performance index is a weighted sum of the state and control covariances that stem from both the random system disturbances and the parameter uncertainties. The numerical solution of the problem is described and application of the method to several initially sensitive tracking systems is discussed. The sensitivity factor of reduction was typically 2 or 3 over a system based on random system noise only, and yet resulted in state RMS increases of only about a factor of two.
NASA Technical Reports Server (NTRS)
Johnson, R. C.
1974-01-01
Sets of routines are presented that calculate such real-gas supersonic stream properties as velocity, density, enthalpy, entropy, and isentropic exponent. Two alternative sets of measurements are assumed: (1) stagnation pressure, stagnation temperature, and the pressure on the surface of a static-pressure wedge; or (2) pressure and temperature in a plenum upstream of a supersonic nozzle and the stagnation pressure at the exit of this nozzle. The routines are applicable to any gas whose properties are known. Explicit routines are presented for determining these properties for air, nitrogen, oxygen, normal hydrogen, para-hydrogen, helium, argon, steam, methane, and natural gas.
Relativistic calculations of screening parameters and atomic radii of neutral atoms
NASA Astrophysics Data System (ADS)
Guerra, M.; Amaro, P.; Santos, J. P.; Indelicato, P.
2017-09-01
Calculations of the effective nuclear charge for elements with 1 ≤ Z ≤ 118 have been performed in a Dirac-Fock approach including all relativistic effects as well as contributions from quantum electrodynamics. Maximum charge density for every subshell of every element in the periodic table was also computed in the same framework as well as atomic radii based on the total charge density. Results were compared with the extensively cited works of Clementi et al., obtained in the 1960s with Roothan's self-consistent-field method.
Zhang, Jianying; Chen, Gangling; Gong, Xuedong
2017-06-01
The quantitative structure-property relationship (QSPR) methodology was applied to describe and seek the relationship between the structures and energetic properties (and sensitivity) for some common energy compounds. An extended series of structural and energetic descriptors was obtained with density functional theory (DFT) B3LYP and semi-empirical PM3 approaches. Results indicate that QSPR model constructed using quantum descriptors can be applied to verify the confidence of calculation results compared with experimental data. It can be extended to predict the properties of similar compounds.
NASA Astrophysics Data System (ADS)
Kwanka, K.; Ortinger, W.; Steckel, J.
1994-01-01
First experimental investigations performed on a new test rig are presented. For a staggered labyrinth seal with fourteen cavities the stiffness coefficient and the leakage flow are measured. The experimental results are compared to calculated results which are obtained by a one-volume bulk-flow theory. A perturbation analysis is made for seven terms. It is found out that the friction factors have great impact on the dynamic coefficients. They are obtained by turbulent flow computation by a finite-volume model with the Reynolds equations used as basic equations.
NASA Technical Reports Server (NTRS)
Kwanka, K.; Ortinger, W.; Steckel, J.
1994-01-01
First experimental investigations performed on a new test rig are presented. For a staggered labyrinth seal with fourteen cavities the stiffness coefficient and the leakage flow are measured. The experimental results are compared to calculated results which are obtained by a one-volume bulk-flow theory. A perturbation analysis is made for seven terms. It is found out that the friction factors have great impact on the dynamic coefficients. They are obtained by turbulent flow computation by a finite-volume model with the Reynolds equations used as basic equations.
Calculation of Source and Strucutral Parameters at Regional and Teleseismic Distances
1987-02-28
Williams, L.A.J., 1972. Geology of the Eastern Rift System; Geol. Soc. of Amer. Spec. Paper #136, 67 p. Barker, J.S. & Langston, CA., 1981. Inversion of...Parameters, Regional Wave Propagation, Waveguide Scattering, T-Matrix. Upper Mantle Structure. Australia . India 1». ABSTRACT (Continu* on nttftrt« if...8hort-Period ^ *nd near-regional seismograms from l?t:L^ 5 ~A ) ^ar^uake3 located 1« Australia and India. When the effect of crusta
Two Approaches to the Calculation of Approximate Symmetry of Ostrovsky Equation with Small Parameter
NASA Astrophysics Data System (ADS)
Mahdavi, Abolhassan; Nadjafikhah, Mehdi; Toomanian, Megerdich
2015-12-01
In this paper, two methods of approximate symmetries for partial differential equations with a small parameter are applied to a perturbed nonlinear Ostrovsky equation. To compute the first-order approximate symmetry, we have applied two methods which one of them was proposed by Baikov et al. in which the infinitesimal generator is expanded in a perturbation series; whereas the other method by Fushchich and Shtelen [3] is based on the expansion of the dependent variables in perturbation series. Especially, an optimal system of one dimensional subalgebras is constructed and some invariant solutions corresponding to the resulted symmetries are obtained.
Validity of the semi-classical approach for calculation of the surface excitation parameter.
Da, B; Mao, S F; Ding, Z J
2011-10-05
The problem of surface plasmon excitation by moving charges has been elaborated by several different approaches, mainly based on dielectric response theory within either semi-classical or quantum mechanical frameworks. In this work, a comparison of the surface excitation effect between two different frameworks is made by calculation of the differential inverse inelastic mean free path (DIIMFP) and a Monte Carlo simulation of reflection electron energy loss spectroscopy (REELS) spectra. A semi-classical modeling of the interaction between electrons and a solid surface is based on analyzing the work done by moving electrons; the stopping power and inelastic cross section are derived with the induced potential. On the other hand, a quantum mechanical approach is based on derivation of the complex inhomogeneous self-energy of the electrons. The numerical calculation shows that the semi-classical model presents almost the same values of DIIMFP as by the quantum model except at the glancing condition. The simulation of REELS spectra for Ag and SiO(2) as well as a comparison with experimental spectra also confirms that a good agreement with the spectral shape is found among the two simulation results and the experimental data.
Rafiee, Marjan; Javaheri, Masoumeh
2015-01-01
Tyrosinase is a multifunctional copper-containing enzyme. It can catalyze two distinct reactions of melanin synthesis and benzaldehyde derivatives, which are potential tyrosinase inhibitors. To find the relationships between charge distributions of benzaldehyde and their pharmaceutical behavior, the present study aimed at investigating nuclear quadrupole coupling constants of quadrupolare nuclei in the functional benzaldehyde group and calculating some its derivatives. In addition, the differences between the electronic structures of various derivatives of this depigmenting drug were examined. All ab initio calculations were carried out using Gaussian 03. The results predicted benzaldehyde derivatives to be bicentral inhibitors; nevertheless, the oxygen or hydrogen contents of the aldehyde group were not found to be the only active sites. Furthermore with the presence of the aldehyde group, the terminal methoxy group in C4 was found to contribute to tyrosinase inhibitory activities. In addition, an oxygen atom with high charge density in the side chain was found to play an important role in its inhibitory effect. PMID:27844007
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
NASA Astrophysics Data System (ADS)
Boden, Christopher D. J.; Pattenden, Gerald
1999-03-01
Ab initio calculations at the RHF/6-31G* and MP2/6- 31G*//RHF/6-31G* levels of theory are performed for 2-methyl-4-carboxamido-oxazoles and -thiazoles, including rotational profiles for the ring-carboxamide bond, which showed the expected conjugation and hydrogen bonding effects. On the basis of these data, newly optimised stretch, bend and torsional parameters for the AMBER* force field are derived, along with CHELPG-fitted partial atomic charges.
NASA Astrophysics Data System (ADS)
Akhmed-Ogly, K. V.; Savichev, O. G.; Tokarenko, O. G.; Pasechnik, E. Yu; Reshetko, M. V.; Nalivajko, N. G.; Vlasova, M. V.
2014-08-01
Technique for the domestic wastewater treatment in the small residential areas and oil and gas facilities of the natural and man-made systems including a settling tank for mechanical treatment and a biological pond with peat substrate and bog vegetation for biological treatment has been substantiated. Technique for parameters calculation of the similar natural and man-made systems has been developed. It was proven that effective treatment of wastewater can be performed in Siberia all year round.
Elastic parameters of paramagnetic iron-based alloys from first-principles calculations
NASA Astrophysics Data System (ADS)
Zhang, Hualei; Punkkinen, Marko P. J.; Johansson, Börje; Vitos, Levente
2012-02-01
The elastic properties of paramagnetic (PM) Fe1-xMx (M = Al, Si, V, Cr, Mn, Co, Ni, and Rh; 0 ≤ x ≤ 0.1) solid solutions in the body-centered-cubic (bcc) and face-centered-cubic (fcc) structures are investigated using the exact muffin-tin orbital density functional method in combination with the coherent-potential approximation and disordered local-magnetic-moment model. All impurities considered here enlarge or leave nearly constant the equilibrium volume of PM Fe but at the same time produce both positive and negative changes in the elastic parameters. Some of the alloying elements induce opposite effects on shear elastic parameters C' and C44 of PM bcc and fcc Fe, which is discussed. With a few exceptions, we find that the alloying effects on PM bcc Fe are smaller than on PM fcc Fe. The trends in the tetragonal elastic constant C' show a general correlation with the trends obtained for the bcc-fcc lattice energy difference.
Rivard, Mark J; Davis, Stephen D; DeWerd, Larry A; Rusch, Thomas W; Axelrod, Steve
2006-11-01
A new x-ray source, the model S700 Axxent X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, < 1 mm, use of the one-dimensional (1D) brachytherapy dosimetry formalism is not recommended due to polar anisotropy. Consequently, 1D brachytherapy dosimetry parameters were not sought. Calculated point-source model radial dose functions at gP(5) were 0.20, 0.24, and 0.29 for the 40, 45, and 50 kV voltage settings, respectively. For 1
NASA Astrophysics Data System (ADS)
Ma, Tao; Zhang, Weigang; Zhang, Yang; Tang, Ting
2015-01-01
The current research of complex nonlinear system robust optimization mainly focuses on the features of design parameters, such as probability density functions, boundary conditions, etc. After parameters study, high-dimensional curve or robust control design is used to find an accurate robust solution. However, there may exist complex interaction between parameters and practical engineering system. With the increase of the number of parameters, it is getting hard to determine high-dimensional curves and robust control methods, thus it's difficult to get the robust design solutions. In this paper, a method of global sensitivity analysis based on divided variables in groups is proposed. By making relevant variables in one group and keeping each other independent among sets of variables, global sensitivity analysis is conducted in grouped variables and the importance of parameters is evaluated by calculating the contribution value of each parameter to the total variance of system response. By ranking the importance of input parameters, relatively important parameters are chosen to conduct robust design analysis of the system. By applying this method to the robust optimization design of a real complex nonlinear system-a vehicle occupant restraint system with multi-parameter, good solution is gained and the response variance of the objective function is reduced to 0.01, which indicates that the robustness of the occupant restraint system is improved in a great degree and the method is effective and valuable for the robust design of complex nonlinear system. This research proposes a new method which can be used to obtain solutions for complex nonlinear system robust design.
NASA Technical Reports Server (NTRS)
Szatmary, Steven A.; Gyekenyesi, John P.; Nemeth, Noel N.
1990-01-01
This manual describes the operation and theory of the PC-CARES (Personal Computer-Ceramic Analysis and Reliability Evaluation of Structures) computer program for the IBM PC and compatibles running PC-DOS/MS-DOR OR IBM/MS-OS/2 (version 1.1 or higher) operating systems. The primary purpose of this code is to estimate Weibull material strength parameters, the Batdorf crack density coefficient, and other related statistical quantities. Included in the manual is the description of the calculation of shape and scale parameters of the two-parameter Weibull distribution using the least-squares analysis and maximum likelihood methods for volume- and surface-flaw-induced fracture in ceramics with complete and censored samples. The methods for detecting outliers and for calculating the Kolmogorov-Smirnov and the Anderson-Darling goodness-of-fit statistics and 90 percent confidence bands about the Weibull line, as well as the techniques for calculating the Batdorf flaw-density constants are also described.
40 CFR 80.599 - How do I calculate volume balances for designation purposes?
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 17 2012-07-01 2012-07-01 false How do I calculate volume balances for... § 80.599 How do I calculate volume balances for designation purposes? (a) Quarterly compliance periods... June 30, 2013. July 1, 2013 May 31, 2014. (2) (b) Volume balance for motor vehicle diesel fuel. (1) A...
40 CFR 80.599 - How do I calculate volume balances for designation purposes?
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 16 2011-07-01 2011-07-01 false How do I calculate volume balances for... § 80.599 How do I calculate volume balances for designation purposes? (a) Quarterly compliance periods... June 30, 2013. July 1, 2013 May 31, 2014. (2) (b) Volume balance for motor vehicle diesel fuel. (1) A...
40 CFR 80.599 - How do I calculate volume balances for designation purposes?
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 16 2010-07-01 2010-07-01 false How do I calculate volume balances for... § 80.599 How do I calculate volume balances for designation purposes? (a) Quarterly compliance periods... June 30, 2013. July 1, 2013 May 31, 2014. (2) (b) Volume balance for motor vehicle diesel fuel. (1) A...
40 CFR 80.599 - How do I calculate volume balances for designation purposes?
Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 17 2014-07-01 2014-07-01 false How do I calculate volume balances for... § 80.599 How do I calculate volume balances for designation purposes? (a) Quarterly compliance periods... June 30, 2013. July 1, 2013 May 31, 2014. (2) (b) Volume balance for motor vehicle diesel fuel. (1) A...
40 CFR 80.599 - How do I calculate volume balances for designation purposes?
Code of Federal Regulations, 2013 CFR
2013-07-01
... 40 Protection of Environment 17 2013-07-01 2013-07-01 false How do I calculate volume balances for... § 80.599 How do I calculate volume balances for designation purposes? (a) Quarterly compliance periods... June 30, 2013. July 1, 2013 May 31, 2014. (2) (b) Volume balance for motor vehicle diesel fuel. (1) A...
Parameter-tolerant design of high contrast gratings
NASA Astrophysics Data System (ADS)
Chevallier, Christyves; Fressengeas, Nicolas; Jacquet, Joel; Almuneau, Guilhem; Laaroussi, Youness; Gauthier-Lafaye, Olivier; Cerutti, Laurent; Genty, Frédéric
2015-02-01
This work is devoted to the design of high contrast grating mirrors taking into account the technological constraints and tolerance of fabrication. First, a global optimization algorithm has been combined to a numerical analysis of grating structures (RCWA) to automatically design HCG mirrors. Then, the tolerances of the grating dimensions have been precisely studied to develop a robust optimization algorithm with which high contrast gratings, exhibiting not only a high efficiency but also large tolerance values, could be designed. Finally, several structures integrating previously designed HCGs has been simulated to validate and illustrate the interest of such gratings.
A theoretical study of high-pressure-induced phases of LiAlH4 using calculated NQCC parameters
NASA Astrophysics Data System (ADS)
Rafiee, Marjan A.
2016-12-01
Quadrupolar parameters of nuclei can be used as a tool to understand the electronic structure of compounds. Lithium alanate (LiAlH4) is a potential hydrogen storage material because of its high capacity of 10.5 wt % H2. However, the drawbacks of its dehydrogenation process are the relatively high temperatures and the slow dehydrogenation kinetics; furthermore, its reversibility is rather poor. Understanding the bonding nature of Al and H is essential for improving its dehydrogenation performance. In this work the charge density distribution in LiAlH4 is studied. Thus using calculated nuclear quadrupole coupling constants of hydrogens (2H-NQCCs), the electronic structure of α-LiAlH4 with high pressure forms of LiAlH4, (β- and γ-LiAlH4) were compared. The results show that easier condition for dehydrogenation is expected in β-LiAlH4. Comparison of calculated dehydrogenation enthalpies of LiAlH4 phases verifies this prediction. The electric field gradient (EFG) of quadrupolar nuclei were calculated to obtain NQCC parameters. All calculations performed using Gaussian 03 at B3LYP/6-31G* level of theory.
Strömberg, Eric A; Nyberg, Joakim; Hooker, Andrew C
2016-12-01
With the increasing popularity of optimal design in drug development it is important to understand how the approximations and implementations of the Fisher information matrix (FIM) affect the resulting optimal designs. The aim of this work was to investigate the impact on design performance when using two common approximations to the population model and the full or block-diagonal FIM implementations for optimization of sampling points. Sampling schedules for two example experiments based on population models were optimized using the FO and FOCE approximations and the full and block-diagonal FIM implementations. The number of support points was compared between the designs for each example experiment. The performance of these designs based on simulation/estimations was investigated by computing bias of the parameters as well as through the use of an empirical D-criterion confidence interval. Simulations were performed when the design was computed with the true parameter values as well as with misspecified parameter values. The FOCE approximation and the Full FIM implementation yielded designs with more support points and less clustering of sample points than designs optimized with the FO approximation and the block-diagonal implementation. The D-criterion confidence intervals showed no performance differences between the full and block diagonal FIM optimal designs when assuming true parameter values. However, the FO approximated block-reduced FIM designs had higher bias than the other designs. When assuming parameter misspecification in the design evaluation, the FO Full FIM optimal design was superior to the FO block-diagonal FIM design in both of the examples.
NASA Technical Reports Server (NTRS)
Reddy, C. J.
1998-01-01
An implementation of the Model Based Parameter Estimation (MBPE) technique is presented for obtaining the frequency response of the Radar Cross Section (RCS) of arbitrarily shaped, three-dimensional perfect electric conductor (PEC) bodies. An Electric Field Integral Equation (EFTE) is solved using the Method of Moments (MoM) to compute the RCS. The electric current is expanded in a rational function and the coefficients of the rational function are obtained using the frequency derivatives of the EFIE. Using the rational function, the electric current on the PEC body is obtained over a frequency band. Using the electric current at different frequencies, RCS of the PEC body is obtained over a wide frequency band. Numerical results for a square plate, a cube, and a sphere are presented over a bandwidth. Good agreement between MBPE and the exact solution over the bandwidth is observed.
Sun, Shuh-Ping; Hsu, Ko-Wen; Chen, Jing-Shyr
2008-05-01
Cosmetic doctor utilizes the position, size and shapes of female's breast to judge whether the breast is under steady-state condition after breast implant plastic surgery. Since, doctor evaluates the breast condition with the subjective discrimination (such as vision, sense of touch) without using the objective physical parameters auxiliary. This study uses the 3D optics scanner editing 3D image to obtain full-scale 3D female breasts image. The CAD system converts the breast position, size and shapes, as the length of the curve between UBL (upper breast line) and NBL (nipple base line), the length of the curve between NBL and LBL (lower breast line), breast volume and breasts congruence rate. The stability after the breast implant plastic surgery is one of the important successful indexes of plastic surgery, so with the continuity analysis the breast curve length, volume and congruence rate can let the doctor really grasp the stability of the breast after plastic surgery.
NASA Astrophysics Data System (ADS)
Ringe, Stefan; Oberhofer, Harald; Reuter, Karsten
2017-04-01
Implicit solvation calculations based on a Stern-layer corrected size-modified Poisson-Boltzmann (SMPB) model are an effective approach to capture electrolytic effects in first-principles electronic structure calculations. For a given salt solution, they require a range of ion-specific parameters, which describe the size of the dissolved ions as well as thickness and shape of the Stern layer. Out of this defined parameter space, we show that the Stern layer thickness expressed in terms of the solute's electron density and the resulting ionic cavity volume completely determine ion effects on the stability of neutral solutes. Using the efficient SMPB functionality of the full-potential density-functional theory package FHI-aims, we derive optimized such Stern layer parameters for neutral solutes in various aqueous monovalent electrolytes. The parametrization protocol relies on fitting to reference Setschenow coefficients that describe solvation free energy changes with ionic strength at low to medium concentrations. The availability of such data for NaCl solutions yields a highly predictive SMPB model that allows to recover the measured Setschenow coefficients with an accuracy that is comparable to prevalent quantitative regression models. Correspondingly derived SMPB parameters for other salts suffer from a much scarcer experimental data base but lead to Stern layer properties that follow a physically reasonable trend with ionic hydration numbers.
Optimization of reserve lithium thionyl chloride battery electrochemical design parameters
NASA Astrophysics Data System (ADS)
Doddapaneni, N.; Godshall, N. A.
The performance of Reserve Lithium Thionyl Chloride (RLTC) batteries was optimized by conducting a parametric study of seven electrochemical parameters: electrode compression, carbon thickness, presence of catalyst, temperature, electrode limitation, discharge rate, and electrolyte acidity. Increasing electrode compression (from 0 to 15 percent) improved battery performance significantly (10 percent greater carbon capacity density). Although thinner carbon cathodes yielded less absolute capacity than did thicker cathodes, they did so with considerably higher volume efficiencies. The effect of these parameters, and their synergistic interactions, on electrochemical cell performance is illustrated.
A calculation of steady-state electrocoloration parameters of electrochromic systems
Ushakov, O.A.; Shelepin, I.V.
1986-01-01
Electrochromic systems based on solutions of compounds whichchange their color reversibly when electrochemical reactions take place may find wide applications in the design of laser-light modulators, light filters with variable optical density, and means for visual information display. It is the aim of this work to find the limiting steady-state values of current density and electrically induced optical density for electrochromic systems and to discuss possibilities of eliminating solution convection during current flow in them. During prolonged electrocoloration, the convection of anolyte and catholyte in opposite directions can lead to ''glistering'' or separation of the solution layer.
Design parameters of a solar-driven heat engine
Goektun, S.
1996-01-01
Maximum power and efficiency are treated at the maximum power output of an internally and externally irreversible solar-driven power plant heat engine. It was found that the thermal efficiency depends on the cycle-irreversibility parameter must be less than 1.0 for maximum power output.
Calculation of DSSC parameters based on ZnO nanorod/TiO2 mesoporous photoanode
NASA Astrophysics Data System (ADS)
Safriani, L.; Nurrida, A.; Mulyana, C.; Susilawati, T.; Bahtiar, A.; Aprilia, A.
2017-07-01
Photoanode of dye sensitized solar cell (DSSC) plays an important role as electron transport media to accept photogenerated electron from excited state of dye. There are several physical properties that are required from photoanode of DSSC. It should be highly transparent, have large surface area, has a conduction band lower than LUMO of dye molecule, has high charge carrier mobility and finally has a good stability in redox electrolyte process. In this work, DSSC with structure FTO/ZnO nanorod/TiO2 mesoporous/Ru-dye/gel electrolyte/ Pt/FTO has been fabricated. In order to modified the structures of photoanode, ZnO nanorod was grown on aluminium doped ZnO seed layer by variation concentration of Al (0 wt%, 0.5 wt% and 1.0 wt%). Zinc nitrate hexahydrate and hexamethylenetetramine used as raw materials for ZnO nanorod growth solution and deposited by self-assembly methods on FTO/Al doped ZnO seed layer. It is then followed by deposition of titania (TiO2) paste by screen printing methods. DSSC parameters i.e. ideally factor (n), series resistance (RS ), and shunt resistance (RSH ) was derived from current density-voltage (I-V) curve using the simplify equation of ideal diode model. The influences of ZnO photoanode structures to the solar cell performance will be completely discussed.
Analytical calculation of sensing parameters on carbon nanotube based gas sensors.
Akbari, Elnaz; Buntat, Zolkafle; Ahmad, Mohd Hafizi; Enzevaee, Aria; Yousof, Rubiyah; Iqbal, Syed Muhammad Zafar; Ahmadi, Mohammad Taghi; Sidik, Muhammad Abu Bakar; Karimi, Hediyeh
2014-03-20
Carbon Nanotubes (CNTs) are generally nano-scale tubes comprising a network of carbon atoms in a cylindrical setting that compared with silicon counterparts present outstanding characteristics such as high mechanical strength, high sensing capability and large surface-to-volume ratio. These characteristics, in addition to the fact that CNTs experience changes in their electrical conductance when exposed to different gases, make them appropriate candidates for use in sensing/measuring applications such as gas detection devices. In this research, a model for a Field Effect Transistor (FET)-based structure has been developed as a platform for a gas detection sensor in which the CNT conductance change resulting from the chemical reaction between NH3 and CNT has been employed to model the sensing mechanism with proposed sensing parameters. The research implements the same FET-based structure as in the work of Peng et al. on nanotube-based NH3 gas detection. With respect to this conductance change, the I-V characteristic of the CNT is investigated. Finally, a comparative study shows satisfactory agreement between the proposed model and the experimental data from the mentioned research.
NASA Astrophysics Data System (ADS)
Santos-Martins, Diogo; Fernandes, Pedro Alexandrino; Ramos, Maria João
2016-11-01
In the context of SAMPL5, we submitted blind predictions of the cyclohexane/water distribution coefficient (D) for a series of 53 drug-like molecules. Our method is purely empirical and based on the additive contribution of each solute atom to the free energy of solvation in water and in cyclohexane. The contribution of each atom depends on the atom type and on the exposed surface area. Comparatively to similar methods in the literature, we used a very small set of atomic parameters: only 10 for solvation in water and 1 for solvation in cyclohexane. As a result, the method is protected from overfitting and the error in the blind predictions could be reasonably estimated. Moreover, this approach is fast: it takes only 0.5 s to predict the distribution coefficient for all 53 SAMPL5 compounds, allowing its application in virtual screening campaigns. The performance of our approach (submission 49) is modest but satisfactory in view of its efficiency: the root mean square error (RMSE) was 3.3 log D units for the 53 compounds, while the RMSE of the best performing method (using COSMO-RS) was 2.1 (submission 16). Our method is implemented as a Python script available at https://github.com/diogomart/SAMPL5-DC-surface-empirical.
Analytical Calculation of Sensing Parameters on Carbon Nanotube Based Gas Sensors
Akbari, Elnaz; Buntat, Zolkafle; Ahmad, Mohd Hafizi; Enzevaee, Aria; Yousof, Rubiyah; Iqbal, Syed Muhammad Zafar; Ahmadi, Mohammad Taghi.; Sidik, Muhammad Abu Bakar; Karimi, Hediyeh
2014-01-01
Carbon Nanotubes (CNTs) are generally nano-scale tubes comprising a network of carbon atoms in a cylindrical setting that compared with silicon counterparts present outstanding characteristics such as high mechanical strength, high sensing capability and large surface-to-volume ratio. These characteristics, in addition to the fact that CNTs experience changes in their electrical conductance when exposed to different gases, make them appropriate candidates for use in sensing/measuring applications such as gas detection devices. In this research, a model for a Field Effect Transistor (FET)-based structure has been developed as a platform for a gas detection sensor in which the CNT conductance change resulting from the chemical reaction between NH3 and CNT has been employed to model the sensing mechanism with proposed sensing parameters. The research implements the same FET-based structure as in the work of Peng et al. on nanotube-based NH3 gas detection. With respect to this conductance change, the I–V characteristic of the CNT is investigated. Finally, a comparative study shows satisfactory agreement between the proposed model and the experimental data from the mentioned research. PMID:24658617
Recommended environmental dose calculation methods and Hanford-specific parameters. Revision 2
Schreckhise, R.G.; Rhoads, K.; Napier, B.A.; Ramsdell, J.V.; Davis, J.S.
1993-03-01
This document was developed to support the Hanford Environmental Dose overview Panel (HEDOP). The Panel is responsible for reviewing all assessments of potential doses received by humans and other biota resulting from the actual or possible environmental releases of radioactive and other hazardous materials from facilities and/or operations belonging to the US Department of Energy on the Hanford Site in south-central Washington. This document serves as a guide to be used for developing estimates of potential radiation doses, or other measures of risk or health impacts, to people and other biota in the environs on and around the Hanford Site. It provides information to develop technically sound estimates of exposure (i.e., potential or actual) to humans or other biotic receptors that could result from the environmental transport of potentially harmful materials that have been, or could be, released from Hanford operations or facilities. Parameter values and information that are specific to the Hanford environs as well as other supporting material are included in this document.
Back-calculation of temperature parameters for determination of asphalt layer modulus
NASA Astrophysics Data System (ADS)
Dong, Qinxi; Matsui, Kunihito; Yamamoto, Kazuya; Higashi, Shigeo
2000-05-01
The pavement elastic modulus of each layer was usually assumed not to be dependent on the environmental factors when the backcalculation of asphalt pavement was conducted from the measured surface deflections of FWD. However, it is well known that the elastic modulus of asphalt layer changes with the variation of temperature. Considering the influence of atmospheric temperature and radiant heat, the temperature distribution is nonlinear along the asphalt layer thickness, and has always been changed. Therefore, the distribution of elastic modulus in the asphalt layer has been considered to change as well. In this paper, we assume the elastic modulus distribution of the asphalt layer to vary with its temperature in terms of the exponential form. Based on the finite element method forward analysis, we propose a method to estimate a standard elastic modulus and temperature coefficient at 20 degrees Celsius for the asphalt layer from the backcalculation analysis. The corresponding FEM backcalculation program using Gauss-Newton method was developed to determine the pavement layer moduli and temperature dependent coefficient, in which the singular value decomposition (SVD) was used for the inverse analysis with scaling of unknown parameters. This method results in a smaller condition number that contributes to improvement of numerical stability. Both numerical simulation and measured data from FWD testing are used to demonstrate the potential applications of this method. As a result, the backcalculation procedure is less dependent on the user's initial values, fast in convergence rate and effective in the pavement engineering.
Vajeeston, P; Ravindran, P; Fjellvåg, H
2011-10-06
The electronic structure, lattice dynamics, and mechanical properties of AlH(3) phases have been studied by density functional calculations. The chemical bonding in different polymorphs of AlH(3) are evaluated on the basis of electronic structures, charge density analysis, and atomic charges, as well as bond overlap population analysis and the Born effective charges. The phonon dispersion relations and phonon density of states of all the polymorphs of AlH(3) are calculated by direct force-constant method. Application of pressure induces seqauence of phase transitions in β-AlH(3) which are understood from the phonon dispersive curves of the involved phases. The previously predicted phases (Chem. Mater. 2008, 20, 5997) are found to be dynamically stable. The calculated single crystal elastic constants reveal that all the studied AlH(3) polymorphs are easily compressible. The chemical bonding of these polymorphs have noticeable covalent character (except the hp2 phase) according to the present chemical bonding analyses. For all these polymorphs, the NMR-related parameters, such as isotropic chemical shielding, quadrupolar coupling constant, and quadrupolar asymmetry, are also calculated. All IR- and Raman-active phonon frequencies, as well as the corresponding intensities, are calculated for all the AlH(3) polymorphs and are compared with available experimental results.
Garger, Evgenii K; Meisenberg, Oliver; Odintsov, Oleksiy; Shynkarenko, Viktor; Tschiersch, Jochen
2013-10-15
Nuclear fuel particles of Chernobyl origin are carriers of increased radioactivity (hot particles) and are still present in the atmosphere of the Chernobyl exclusion zone. Workers in the zone may inhale these particles, which makes assessment necessary. The residence time in the lungs and the transfer in the blood of the inhaled radionuclides are crucial for inhalation dose assessment. Therefore, the dissolution of several kinds of nuclear fuel particles from air filters sampled in the Chernobyl exclusion zone was studied. For this purpose filter fragments with hot particles were submersed in simulated lung fluids (SLFs). The activities of the radionuclides (137)Cs, (90)Sr, (239+240)Pu and (241)Am were measured in the SLF and in the residuum of the fragments by radiometric methods after chemical treatment. Soluble fractions as well as dissolution rates of the nuclides were determined. The influence of the genesis of the hot particles, represented by the (137)Cs/(239+240)Pu ratio, on the availability of (137)Cs was demonstrated, whereas the dissolution of (90)Sr, (239+240)Pu and (241)Am proved to be independent of genesis. No difference in the dissolution of (137)Cs and (239+240)Pu was observed for the two applied types of SLF. Increased solubility was found for smaller hot particles. A two-component exponential model was used to describe the dissolution of the nuclides as a function of time. The results were applied for determining individual inhalation dose coefficients for the workers at the Chernobyl construction site. Greater dose coefficients for the respiratory tract and smaller coefficients for the other organs were calculated (compared to ICRP default values). The effective doses were in general lower for the considered radionuclides, for (241)Am even by one order of magnitude.
Influence of Gear Design Parameters on Gearbox Radiated Noise
NASA Technical Reports Server (NTRS)
Oswald, Fred B.; Townsend, Dennis P.; Valco, Mark J.; Spencer, Robert H.; Drago, Raymond J.; Lenski, Joseph W., Jr.
1994-01-01
Spur and helical gears were tested in the NASA gear-noise rig to compare the noise produced by different gear designs. Sound power measurements were performed under controlled conditions for a matrix of operating conditions. Sound power was computed from near-field acoustic intensity scans taken just above the top surface of the gearbox. Test gears included four spur and five helical gear designs. The gears were designed to be as nearly identical as possible except for deliberate differences in tooth geometry and contact ratio. Test results are presented as a function of the gear design and operating conditions in the form of sound power charts and as narrow-band spectra.
Influence of gear design parameters on gearbox radiated noise
NASA Astrophysics Data System (ADS)
Oswald, Fred B.; Townsend, Dennis P.; Valco, Mark J.; Spencer, Robert H.; Drago, Raymond J.; Lenski, Joseph W., Jr.
1994-03-01
Spur and helical gears were tested in the NASA gear-noise rig to compare the noise produced by different gear designs. Sound power measurements were performed under controlled conditions for a matrix of operating conditions. Sound power was computed from near-field acoustic intensity scans taken just above the top surface of the gearbox. Test gears included four spur and five helical gear designs. The gears were designed to be as nearly identical as possible except for deliberate differences in tooth geometry and contact ratio. Test results are presented as a function of the gear design and operating conditions in the form of sound power charts and as narrow-band spectra.
Multivariate Assessment of the Effect of Pump Design and Pump Gap Design Parameters on Blood Trauma.
Graefe, Roland; Henseler, Andreas; Steinseifer, Ulrich
2016-06-01
Pump gaps are the most critical regions in a rotary blood pump when it comes to blood trauma in the form of hemolysis, protein destruction, and platelet activation. This study investigated six pump design parameters affecting the flow in a radial pump gap. A multivariate approach was employed to determine individual and quantitative parameter effects on blood trauma as well as parameter interactions. To consider the effect of shear stress and blood cell residence time, a validated numerical Lagrangian particle tracking approach was used. Based on the results, small-diameter pumps can be as blood compatible, if not more blood compatible, as large-diameter pumps as long as identical circumferential velocities and clearance gaps are maintained. Furthermore, the results indicate that an eccentric rotor position in the casing is not harmful and that a pressure difference generating washout flow and thereby reducing the cell residence time is of significant importance. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
Hilser, V J; Gómez, J; Freire, E
1996-10-01
Two effects are mainly responsible for the observed enthalpy change in protein unfolding: the disruption of internal interactions within the protein molecule (van der Waals, hydrogen bonds, etc.) and the hydration of the groups that are buried in the native state and become exposed to the solvent on unfolding. In the traditional thermodynamic analysis, the effects of hydration have usually been evaluated using the thermodynamic data for the transfer of small model compounds from the gas phase to water. The contribution of internal interactions, on the other hand, are usually estimated by subtracting the hydration effects from the experimental enthalpy of unfolding. The main drawback of this approach is that the enthalpic contributions of hydration, and those due to the disruption of internal interactions, are more than one order of magnitude larger than the experimental enthalpy value. The enthalpy contributions of hydration and disruption of internal interactions have opposite signs and cancel each other almost completely resulting in a final value that is over 10 times smaller than the individual terms. For this reason, the classical approach cannot be used to accurately predict unfolding enthalpies from structure: any error in the estimation of the hydration enthalpy will be amplified by a factor of 10 or more in the estimation of the unfolding enthalpy. Recently, it has been shown that simple parametric equations that relate the enthalpy change with certain structural parameters, especially changes in solvent accessible surface areas have considerable predictive power. In this paper, we provide a physical foundation to that parametrization and in the process we present a system of equations that explicitly includes the enthalpic effects of the packing density between the different atoms within the protein molecule. Using this approach, the error in the prediction of folding/unfolding enthalpies at 60 degrees C, the median temperature for thermal unfolding, is
NEUTRAL INTERSTELLAR HELIUM PARAMETERS BASED ON IBEX-Lo OBSERVATIONS AND TEST PARTICLE CALCULATIONS
Bzowski, M.; Kubiak, M. A.; Sokol, J. M.; Hlond, M.; Moebius, E.; Bochsler, P.; Leonard, T.; Heirtzler, D.; Kucharek, H.; Schwadron, N. A.; Crew, G. B.; Fuselier, S. A.; McComas, D. J.
2012-02-01
Because of its high ionization potential and weak interaction with hydrogen, neutral interstellar helium (NISHe) is almost unaffected at the heliospheric interface with the interstellar medium and freely enters the solar system. This second most abundant species provides some of the best information on the characteristics of the interstellar gas in the local interstellar cloud. The Interstellar Boundary Explorer (IBEX) is the second mission to directly detect NISHe. We present a comparison between recent IBEX NISHe observations and simulations carried out using a well-tested quantitative simulation code. Simulation and observation results compare well for times when measured fluxes are dominated by NISHe (and contributions from other species are small). Differences between simulations and observations indicate a previously undetected secondary population of neutral helium, likely produced by interaction of interstellar helium with plasma in the outer heliosheath. Interstellar neutral parameters are statistically different from previous in situ results obtained mostly from the GAS/Ulysses experiment, but they do agree with the local interstellar flow vector obtained from studies of interstellar absorption: the newly established flow direction is ecliptic longitude 79.{sup 0}2, latitude -5.{sup 0}1, the velocity is {approx}22.8 km s{sup -1}, and the temperature is 6200 K. These new results imply a markedly lower absolute velocity of the gas and thus significantly lower dynamic pressure on the boundaries of the heliosphere and different orientation of the Hydrogen Deflection Plane compared to prior results from Ulysses. A different orientation of this plane also suggests a new geometry of the interstellar magnetic field, and the lower dynamic pressure calls for a compensation by other components of the pressure balance, most likely a higher density of interstellar plasma and strength of interstellar magnetic field.
Poludniowski, Gavin G.; Evans, Philip M.
2013-04-15
Purpose: Monte Carlo methods based on the Boltzmann transport equation (BTE) have previously been used to model light transport in powdered-phosphor scintillator screens. Physically motivated guesses or, alternatively, the complexities of Mie theory have been used by some authors to provide the necessary inputs of transport parameters. The purpose of Part II of this work is to: (i) validate predictions of modulation transform function (MTF) using the BTE and calculated values of transport parameters, against experimental data published for two Gd{sub 2}O{sub 2}S:Tb screens; (ii) investigate the impact of size-distribution and emission spectrum on Mie predictions of transport parameters; (iii) suggest simpler and novel geometrical optics-based models for these parameters and compare to the predictions of Mie theory. A computer code package called phsphr is made available that allows the MTF predictions for the screens modeled to be reproduced and novel screens to be simulated. Methods: The transport parameters of interest are the scattering efficiency (Q{sub sct}), absorption efficiency (Q{sub abs}), and the scatter anisotropy (g). Calculations of these parameters are made using the analytic method of Mie theory, for spherical grains of radii 0.1-5.0 {mu}m. The sensitivity of the transport parameters to emission wavelength is investigated using an emission spectrum representative of that of Gd{sub 2}O{sub 2}S:Tb. The impact of a grain-size distribution in the screen on the parameters is investigated using a Gaussian size-distribution ({sigma}= 1%, 5%, or 10% of mean radius). Two simple and novel alternative models to Mie theory are suggested: a geometrical optics and diffraction model (GODM) and an extension of this (GODM+). Comparisons to measured MTF are made for two commercial screens: Lanex Fast Back and Lanex Fast Front (Eastman Kodak Company, Inc.). Results: The Mie theory predictions of transport parameters were shown to be highly sensitive to both grain size
Poludniowski, Gavin G; Evans, Philip M
2013-04-01
Monte Carlo methods based on the Boltzmann transport equation (BTE) have previously been used to model light transport in powdered-phosphor scintillator screens. Physically motivated guesses or, alternatively, the complexities of Mie theory have been used by some authors to provide the necessary inputs of transport parameters. The purpose of Part II of this work is to: (i) validate predictions of modulation transform function (MTF) using the BTE and calculated values of transport parameters, against experimental data published for two Gd2O2S:Tb screens; (ii) investigate the impact of size-distribution and emission spectrum on Mie predictions of transport parameters; (iii) suggest simpler and novel geometrical optics-based models for these parameters and compare to the predictions of Mie theory. A computer code package called phsphr is made available that allows the MTF predictions for the screens modeled to be reproduced and novel screens to be simulated. The transport parameters of interest are the scattering efficiency (Q sct), absorption efficiency (Q abs), and the scatter anisotropy (g). Calculations of these parameters are made using the analytic method of Mie theory, for spherical grains of radii 0.1-5.0 μm. The sensitivity of the transport parameters to emission wavelength is investigated using an emission spectrum representative of that of Gd2O2S:Tb. The impact of a grain-size distribution in the screen on the parameters is investigated using a Gaussian size-distribution (σ = 1%, 5%, or 10% of mean radius). Two simple and novel alternative models to Mie theory are suggested: a geometrical optics and diffraction model (GODM) and an extension of this (GODM+). Comparisons to measured MTF are made for two commercial screens: Lanex Fast Back and Lanex Fast Front (Eastman Kodak Company, Inc.). The Mie theory predictions of transport parameters were shown to be highly sensitive to both grain size and emission wavelength. For a phosphor screen structure with a
Preliminary safety calculations to improve the design of Molten Salt Fast Reactor
Brovchenko, M.; Heuer, D.; Merle-Lucotte, E.; Allibert, M.; Capellan, N.; Ghetta, V.; Laureau, A.
2012-07-01
Molten salt reactors are liquid fuel reactors so that they are flexible in operation but very different in the safety approach from solid fuel reactors. This study bears on the specific concept named Molten Salt Fast Reactor (MSFR). Since this new nuclear technology is in development, safety is an essential point to be considered all along the R and D studies. This paper presents the first step of the safety approach: the systematic description of the MSFR, limited here to the main systems surrounding the core. This systematic description is the basis on which we will be able to devise accidental scenarios. Thanks to the negative reactivity feedback coefficient, most accidental scenarios lead to reactor shut down. Because of the decay heat generated in the fuel salt, it must be cooled. After the description of the tools developed to calculate the residual heat, the different contributions are discussed in this study. The decay heat of fission products in the MSFR is evaluated to be low (3% of nominal power), mainly due to the reprocessing that transfers the fission products to the gas reprocessing unit. As a result, the contribution of the actinides is significant (0.5% of nominal power). The unprotected loss of heat sink transients are studied in this paper. It appears that slow transients are favorable (> 1 min) to minimize the temperature increase of the fuel salt. This work will be the basis of further safety studies as well as an essential parameter for the design of the draining system. (authors)
Effective Parameters on Seismic Design of Rectangular Underground Structures
Amiri, G. Ghodrati; Maddah, N.; Mohebi, B.
2008-07-08
Underground structures are a significant part of the transportation in the modern society and in the seismic zones should withstand against both seismic and static loadings. Embedded structures should conform to ground deformations during the earthquake but almost exact evaluation of structure to ground distortion is critical. Several two-dimensional finite difference models are used to find effective parameters on racking ratio (structure to ground distortion) including flexibility ratio, various cross sections, embedment depth, and Poisson's ratio of soil. Results show that influence of different cross sections, by themselves is negligible but embedment depth in addition to flexibility ratio and Poisson's ratio is known as a consequential parameter. A comparison with pseudo-static method (simplified frame analysis) is also performed. The results show that for a stiffer structure than soil, racking ratio decreases as the depth of burial decreases; on the other hand, shallow and flexible structures can suffer greater distortion than deeper ones up to 30 percents.
Determination of critical anthropometric parameters for design of respirators
You-Hin Liau
1982-12-01
Anthropometric data were collected from 243 workers in a respirator fit-test programme, and an attempt was made to determine a correlation between these data and the Protection Factor obtained from quantitative fit-testing for half-mask respirators. Data were collected for two direct and five indirect facial measurements from front- and side-view slides of test subjects. For analysis, the data were normalized with relevant respirators dimensions (4 brands and 10 sizes). Results of linear regression analysis indicated that correlation coefficients between Protection Factor and anthropometric data (face length, mouth width, face width, nasal root breadth) were, respectively, 0.04, 0.22, 0.30 and 0.04. These correlation coefficients are for white males without facial hair. The analysis showed the 'critical' parameters to be mouth width and face width; however, a person with certain combinations of anthropometric parameters may provide a better correlation with Protection Factor.
Parameter optimization in AQM controller design to support TCP traffic
NASA Astrophysics Data System (ADS)
Yang, Wei; Yang, Oliver W.
2004-09-01
TCP congestion control mechanism has been widely investigated and deployed on Internet in preventing congestion collapse. We would like to employ modern control theory to specify quantitatively the control performance of the TCP communication system. In this paper, we make use of a commonly used performance index called the Integral of the Square of the Error (ISE), which is a quantitative measure to gauge the performance of a control system. By applying the ISE performance index into the Proportional-plus-Integral controller based on Pole Placement (PI_PP controller) for active queue management (AQM) in IP routers, we can further tune the parameters for the controller to achieve an optimum control minimizing control errors. We have analyzed the dynamic model of the TCP congestion control under this ISE, and used OPNET simulation tool to verify the derived optimized parameters of the controllers.
NASA Astrophysics Data System (ADS)
Moret-Fernández, D.; Latorre, B.
2017-01-01
The water retention curve (θ(h)), which defines the relationship between the volumetric water content (θ) and the matric potential (h), is of paramount importance to characterize the hydraulic behaviour of soils. Because current methods to estimate θ(h) are, in general, tedious and time consuming, alternative procedures to determine θ(h) are needed. Using an upward infiltration curve, the main objective of this work is to present a method to determine the parameters of the van Genuchten (1980) water retention curve (α and n) from the sorptivity (S) and the β parameter defined in the 1D infiltration equation proposed by Haverkamp et al. (1994). The first specific objective is to present an equation, based on the Haverkamp et al. (1994) analysis, which allows describing an upward infiltration process. Secondary, assuming a known saturated hydraulic conductivity, Ks, calculated on a finite soil column by the Darcy's law, a numerical procedure to calculate S and β by the inverse analysis of an exfiltration curve is presented. Finally, the α and n values are numerically calculated from Ks, S and β. To accomplish the first specific objective, cumulative upward infiltration curves simulated with HYDRUS-1D for sand, loam, silt and clay soils were compared to those calculated with the proposed equation, after applying the corresponding β and S calculated from the theoretical Ks, α and n. The same curves were used to: (i) study the influence of the exfiltration time on S and β estimations, (ii) evaluate the limits of the inverse analysis, and (iii) validate the feasibility of the method to estimate α and n. Next, the θ(h) parameters estimated with the numerical method on experimental soils were compared to those obtained with pressure cells. The results showed that the upward infiltration curve could be correctly described by the modified Haverkamp et al. (1994) equation. While S was only affected by early-time exfiltration data, the β parameter had a
Metocean design parameter estimation for fixed platform based on copula functions
NASA Astrophysics Data System (ADS)
Zhai, Jinjin; Yin, Qilin; Dong, Sheng
2017-08-01
Considering the dependent relationship among wave height, wind speed, and current velocity, we construct novel trivariate joint probability distributions via Archimedean copula functions. Total 30-year data of wave height, wind speed, and current velocity in the Bohai Sea are hindcast and sampled for case study. Four kinds of distributions, namely, Gumbel distribution, lognormal distribution, Weibull distribution, and Pearson Type III distribution, are candidate models for marginal distributions of wave height, wind speed, and current velocity. The Pearson Type III distribution is selected as the optimal model. Bivariate and trivariate probability distributions of these environmental conditions are established based on four bivariate and trivariate Archimedean copulas, namely, Clayton, Frank, Gumbel-Hougaard, and Ali-Mikhail-Haq copulas. These joint probability models can maximize marginal information and the dependence among the three variables. The design return values of these three variables can be obtained by three methods: univariate probability, conditional probability, and joint probability. The joint return periods of different load combinations are estimated by the proposed models. Platform responses (including base shear, overturning moment, and deck displacement) are further calculated. For the same return period, the design values of wave height, wind speed, and current velocity obtained by the conditional and joint probability models are much smaller than those by univariate probability. Considering the dependence among variables, the multivariate probability distributions provide close design parameters to actual sea state for ocean platform design.
Rethinking design parameters in the search for optimal dynamic seating.
Pynt, Jennifer
2015-04-01
Dynamic seating design purports to lessen damage incurred during sedentary occupations by increasing sitter movement while modifying muscle activity. Dynamic sitting is currently defined by O'Sullivan et al. ( 2013a) as relating to 'the increased motion in sitting which is facilitated by the use of specific chairs or equipment' (p. 628). Yet the evidence is conflicting that dynamic seating creates variation in the sitter's lumbar posture or muscle activity with the overall consensus being that current dynamic seating design fails to fulfill its goals. Research is needed to determine if a new generation of chairs requiring active sitter involvement fulfills the goals of dynamic seating and aids cardio/metabolic health. This paper summarises the pursuit of knowledge regarding optimal seated spinal posture and seating design. Four new forms of dynamic seating encouraging active sitting are discussed. These are 1) The Core-flex with a split seatpan to facilitate a walking action while seated 2) the Duo balans requiring body action to create rocking 3) the Back App and 4) Locus pedestal stools both using the sitter's legs to drive movement. Unsubstantiated claims made by the designers of these new forms of dynamic seating are outlined. Avenues of research are suggested to validate designer claims and investigate whether these designs fulfill the goals of dynamic seating and assist cardio/metabolic health. Should these claims be efficacious then a new definition of dynamic sitting is suggested; 'Sitting in which the action is provided by the sitter, while the dynamic mechanism of the chair accommodates that action'.
ERIC Educational Resources Information Center
Westine, Carl; Spybrook, Jessaca
2013-01-01
The capacity of the field to conduct power analyses for group randomized trials (GRTs) of educational interventions has improved over the past decade (Authors, 2009). However, a power analysis depends on estimates of design parameters. Hence it is critical to build the empirical base of design parameters for GRTs across a variety of outcomes and…
Parallel calculation of sensitivity derivatives for aircraft design using automatic differentiation
Bischof, C.H.; Knauff, T.L. Jr.; Green, L.L.; Haigler, K.J.
1994-01-01
Realistic multidisciplinary design optimization (MDO) of advanced aircraft using state-of-the-art computers is an extremely challenging problem from both the physical modelling and computer science points of view. In order to produce an efficient aircraft design, many trade-offs must be made among the various physical design variables. Similarly, in order to produce an efficient design scheme, many trade-offs must be made among the various MDO implementation options. In this paper, we examine the effects of vectorization and coarse-grained parallelization on the SD calculation using a representative example taken from a transonic transport design problem.
Data acquisition as a design parameter in the modern AEM
Zaluzec, N.J.
1993-04-01
The components of a modern analytical electron microscope (AEM) are not necessarily optimized. A pessimistic view is presented of an AEM system, particularly on the data acquisition end. The question of how to design the instrument to collect the data efficiently, is considered. Several points for doing this are outlined.
Gas flow parameters in laser cutting of wood- nozzle design
Kali Mukherjee; Tom Grendzwell; Parwaiz A.A. Khan; Charles McMillin
1990-01-01
The Automated Lumber Processing System (ALPS) is an ongoing team research effort to optimize the yield of parts in a furniture rough mill. The process is designed to couple aspects of computer vision, computer optimization of yield, and laser cutting. This research is focused on optimizing laser wood cutting. Laser machining of lumber has the advantage over...
Parameter Space Techniques for Robust Control System Design.
1980-07-01
been further investi- gated by Cruz [2] and Desoer and Wang [3]. In frequency design methods the concept to compensate the loop, such that high gains...of Feedback Systems, McGraw-Hill, New York, 1972. 3. C. A. Desoer and Y. T. Wang, "Foundations of Feedback Theory for Nonlinear Dynamical Systems
Percutaneous multiple electrode connector, design parameters and fabrication (biomedical)
NASA Technical Reports Server (NTRS)
Myers, L. A.
1977-01-01
A percutaneous multielectrode connector was designed which utilizes an ultrapure carbon collar to provide an infection free biocompatible passage through the skin. The device provides reliable electrical continuity, mates and demates readily with the implant, and is fabricated with processes and materials oriented to commercial production.
Development of Design and Economic Parameters for Passive Solar Systems.
1984-09-01
42.50 35.02 29.73 ANNUAL 00 511 883 1394 2062 2888 3878 Soso Pk PARAMETER A .727 .700 .674 .680 .617 . 5684 .561 OFF SOUJTH VTN/DO 81 .008 .008 .008...23.47 16.11 12.21 9.83 8.23 V72/O 73.55 34.02 19.92 13.68 10.37 5.35 6.9e VT3/DD 63.77 29.50 17.21 11.36 8.99 7.24 6.06 ANNULL 0D 251 639 1313 2255
Decoupling interrelated parameters for designing high performance thermoelectric materials.
Xiao, Chong; Li, Zhou; Li, Kun; Huang, Pengcheng; Xie, Yi
2014-04-15
The world's supply of fossil fuels is quickly being exhausted, and the impact of their overuse is contributing to both climate change and global political unrest. In order to help solve these escalating problems, scientists must find a way to either replace combustion engines or reduce their use. Thermoelectric materials have attracted widespread research interest because of their potential applications as clean and renewable energy sources. They are reliable, lightweight, robust, and environmentally friendly and can reversibly convert between heat and electricity. However, after decades of development, the energy conversion efficiency of thermoelectric devices has been hovering around 10%. This is far below the theoretical predictions, mainly due to the interdependence and coupling between electrical and thermal parameters, which are strongly interrelated through the electronic structure of the materials. Therefore, any strategy that balances or decouples these parameters, in addition to optimizing the materials' intrinsic electronic structure, should be critical to the development of thermoelectric technology. In this Account, we discuss our recently developed strategies to decouple thermoelectric parameters for the synergistic optimization of electrical and thermal transport. We first highlight the phase transition, which is accompanied by an abrupt change of electrical transport, such as with a metal-insulator and semiconductor-superionic conductor transition. This should be a universal and effective strategy to optimize the thermoelectric performance, which takes advantage of modulated electronic structure and critical scattering across phase transitions to decouple the power factor and thermal conductivity. We propose that solid-solution homojunction nanoplates with disordered lattices are promising thermoelectric materials to meet the "phonon glass electron crystal" approach. The formation of a solid solution, coupled with homojunctions, allows for
Sadeghi, Mahdi; Taghdiri, Fatemeh; Hamed Hosseini, S.; Tenreiro, Claudio
2010-10-15
Purpose: The formalism recommended by Task Group 60 (TG-60) of the American Association of Physicists in Medicine (AAPM) is applicable for {beta} sources. Radioactive biocompatible and biodegradable {sup 153}Sm glass seed without encapsulation is a {beta}{sup -} emitter radionuclide with a short half-life and delivers a high dose rate to the tumor in the millimeter range. This study presents the results of Monte Carlo calculations of the dosimetric parameters for the {sup 153}Sm brachytherapy source. Methods: Version 5 of the (MCNP) Monte Carlo radiation transport code was used to calculate two-dimensional dose distributions around the source. The dosimetric parameters of AAPM TG-60 recommendations including the reference dose rate, the radial dose function, the anisotropy function, and the one-dimensional anisotropy function were obtained. Results: The dose rate value at the reference point was estimated to be 9.21{+-}0.6 cGy h{sup -1} {mu}Ci{sup -1}. Due to the low energy beta emitted from {sup 153}Sm sources, the dose fall-off profile is sharper than the other beta emitter sources. The calculated dosimetric parameters in this study are compared to several beta and photon emitting seeds. Conclusions: The results show the advantage of the {sup 153}Sm source in comparison with the other sources because of the rapid dose fall-off of beta ray and high dose rate at the short distances of the seed. The results would be helpful in the development of the radioactive implants using {sup 153}Sm seeds for the brachytherapy treatment.
Calculation of structural parameters of a Van Der Waals complex of the CO molecule with a Li+ cation
NASA Astrophysics Data System (ADS)
Bulanin, K. M.; Bulychev, V. P.; Buturlimova, M. V.
2015-12-01
The equilibrium nuclear configuration and the potential energy and dipole moment component surfaces of an isolated Li+-CO complex are calculated quantum-mechanically in the MP4(SDQ)/6-311++G(3df) approximation. The geometrical parameters and the binding energy of the complex are determined. The frequencies and intensities for the fundamental transitions are calculated in the harmonic approximation. The one-, two-, and three-dimensional anharmonic vibrational Schrödinger equations are solved using the variational method. The energies of states of a three-dimensional vibrational system, anharmonic constants, and the frequencies and intensities of fundamental transitions are determined with the anharmonic interactions taken into account. The changes in the frequency and intensity of the C-O stretching vibration upon the formation of the complex are predicted.
Toffoli, Daniele; Simpson, Mary J.; Lucchese, Robert R.
2004-06-01
We have computed cross sections and asymmetry parameters for the outer- and inner-valence photoionization of ethane using the Schwinger variational method with Pade corrections. The calculated total cross section is found to be in rather good agreement with the available electron-impact and photoabsorption measurements. One-electron resonant processes in the (1e{sub g}){sup -1} (3a{sub 1g}){sup -1}, and (2a{sub 1g}){sup -1} ionization channels were examined comparing resonant states predicted from the virtual orbitals of a minimum basis set self-consistent-field (MBS-SCF) calculations with scattering resonances found using a local model potential for the electron-molecule interaction. The analysis of the interaction potential in terms of adiabatic radial components provides a description of the mechanism of the resonant trapping.
NASA Astrophysics Data System (ADS)
Feldman, J. L.; Broughton, J. Q.; Wooten, F.
1991-01-01
Calculations, based on the Stillinger-Weber (SW) interatomic-potential model and the method of long waves, are presented for the elastic properties of amorphous Si (a-Si) and for pressure derivatives of the elastic constants of crystalline Si. Several models of a-Si, relaxed on the basis of the SW potential, are considered, and the external stresses that are associated with these models are evaluated using the Born-Huang relations. The elastic constants appear to obey the isotropy conditions to within a reasonable accuracy and are also consistent with other predictions based on the SW potential at finite temperature obtained by Kluge and Ray. Estimates of the pressure dependence of the elastic constants, Debye temperature, and Grüeisen parameter for a-Si are also provided on the basis of these calculations.
Marsman, A.; Horbatsch, M.
2011-09-15
Previous work [E. Ackad and M. Horbatsch, Phys. Rev. A 78, 062711 (2008)] on supercritical Dirac resonance parameters from extrapolated analytic continuation, obtained with a Fourier grid method, is generalized by numerically solving the coupled Dirac radial equations to a high precision. The equations, which contain the multipole decomposition of the two-center potential, are augmented by a complex absorbing potential and truncated at various orders in the partial wave expansion to demonstrate convergence of the resonance parameters in the limit of vanishing absorber. The convergence of the partial-wave spinor and of the multipole potential expansions is demonstrated in the supercritical regime. The comparison of critical distances with literature values shows that the work provides benchmark results for future two-center calculations without multipole expansion.
Linscheid, A; Sanna, A; Floris, A; Gross, E K U
2015-08-28
We show that the superconducting order parameter and condensation energy density of phonon-mediated superconductors can be calculated in real space from first principles density functional theory for superconductors. This method highlights the connection between the chemical bonding structure and the superconducting condensation and reveals new and interesting properties of superconducting materials. Understanding this connection is essential to describe nanostructured superconducting systems where the usual reciprocal space analysis hides the basic physical mechanism. In a first application we present results for MgB2, CaC6 and hole-doped graphane.
Mandlik, Nandkumar; Patil, B. J.; Bhoraskar, V. N.; Dhole, S. D.; Sahare, P. D.
2014-04-24
Nanorods of CaSO{sub 4}: Dy having diameter 20 nm and length 200 nm have been synthesized by the chemical coprecipitation method. These samples were irradiated with gamma radiation for the dose varying from 0.1 Gy to 50 kGy and their TL characteristics have been studied. TL dose response shows a linear behavior up to 5 kGy and further saturates with increase in the dose. A Computerized Glow Curve Deconvolution (CGCD) program was used for the analysis of TL glow curves. Trapping parameters for various peaks have been calculated by using CGCD program.
NASA Astrophysics Data System (ADS)
Mandlik, Nandkumar; Patil, B. J.; Bhoraskar, V. N.; Sahare, P. D.; Dhole, S. D.
2014-04-01
Nanorods of CaSO4: Dy having diameter 20 nm and length 200 nm have been synthesized by the chemical coprecipitation method. These samples were irradiated with gamma radiation for the dose varying from 0.1 Gy to 50 kGy and their TL characteristics have been studied. TL dose response shows a linear behavior up to 5 kGy and further saturates with increase in the dose. A Computerized Glow Curve Deconvolution (CGCD) program was used for the analysis of TL glow curves. Trapping parameters for various peaks have been calculated by using CGCD program.
NASA Astrophysics Data System (ADS)
Linscheid, A.; Sanna, A.; Floris, A.; Gross, E. K. U.
2015-08-01
We show that the superconducting order parameter and condensation energy density of phonon-mediated superconductors can be calculated in real space from first principles density functional theory for superconductors. This method highlights the connection between the chemical bonding structure and the superconducting condensation and reveals new and interesting properties of superconducting materials. Understanding this connection is essential to describe nanostructured superconducting systems where the usual reciprocal space analysis hides the basic physical mechanism. In a first application we present results for MgB2 , CaC6 and hole-doped graphane.
A Method for Designing CDO Conformed to Investment Parameters
NASA Astrophysics Data System (ADS)
Nakae, Tatsuya; Moritsu, Toshiyuki; Komoda, Norihisa
We propose a method for designing CDO (Collateralized Debt Obligation) that meets investor needs about attributes of CDO. It is demonstrated that adjusting attributes (that are credit capability and issue amount) of CDO to investors' preferences causes a capital loss risk that the agent takes. We formulate a CDO optimization problem by defining an objective function using the above risk and by setting constraints that arise from investor needs and a risk premium that is paid for the agent. Our prototype experiment, in which fictitious underlying obligations and investor needs are given, verifies that CDOs can be designed without opportunity loss and dead stock loss, and that the capital loss is not more than thousandth part of the amount of annual payment under guarantee for small and midium-sized enterprises by a general credit guarantee institution.
Horas, Jorge A; Olguin, Osvaldo R; Rizzotto, Marcos G
2005-04-21
We model the heterogeneous response to radiation of multicellular tumour spheroids assuming position- and volume-dependent radiosensitivity. We propose a method to calculate the overall radiosensitivity parameters to obtain the surviving fraction of tumours. A mathematical model of a spherical tumour with a hypoxic core and a viable rim which is a caricature of a real tumour is constructed. The model is embedded in a two-compartment linear-quadratic (LQ) model, assuming a mixed bivariated Gaussian distribution to attain the radiosensitivity parameters. Ergodicity, i.e., the equivalence between ensemble and volumetric averages is used to obtain the overall radiosensitivities for the two compartments. We obtain expressions for the overall radiosensitivity parameters resulting from the use of both a linear and a nonlinear dependence of the local radiosensitivity with position. The model's results are compared with experimental data of surviving fraction (SF) for multicellular spheroids of different sizes. We make one fit using only the smallest spheroid data and we are able to predict the SF for the larger spheroids. These predictions are acceptable particularly using bounded sensitivities. We conclude with the importance of taking into account the contribution of clonogenic hypoxic cells to radiosensitivity and with the convenience of using bounded local sensitivities to predict overall radiosensitivity parameters.
Forster, A; Hempenstall, J; Tucker, I; Rades, T
2001-09-11
The aim of this study was to determine the miscibility of drug and excipient to predict if glass solutions are likely to form when drug and excipient are melt extruded. Two poorly water-soluble drugs, indomethacin and lacidipine, were selected along with 11 excipients (polymeric and non-polymeric). Estimation of drug/excipient miscibility was performed using a combination of the Hoy and Hoftzyer/Van Krevelen methods for Hansen solubility parameter calculation. Miscibility was experimentally investigated with differential scanning calorimetry (DSC) and hot stage microscopy (HSM). Studies were performed at drug/excipient ratios, 1:4, 1:1 and 4:1. Analysis of the glass transition temperature (T(g)) was performed by quench cooling drug/excipient melts in the DSC. Differences in the drug/excipient solubility parameters of <7.0 MPa(1/2) were predicted to indicate significant miscibility and, therefore, glass solution formation on melt extrusion. In comparison, differences of >10 MPa(1/2) were expected to indicate a lack of miscibility and not form glass solutions when melt extruded. Experimentally, miscibility was shown by changes in drug/excipient melting endotherms and confirmed by HSM investigations. Experimental results were in agreement with solubility parameter predictions. In addition, drug/excipient combinations predicted to be largely immiscible often exhibited more than one T(g) upon reheating in the DSC. Melt extrusion of miscible components resulted in amorphous solid solution formation, whereas extrusion of an "immiscible" component led to amorphous drug dispersed in crystalline excipient. In conclusion, combining calculation of Hansen solubility parameters with thermal analysis of drug/excipient miscibility can be successfully applied to predict formation of glass solutions with melt extrusion.
Controller Design for Linear Stochastic Systems with Uncertain Parameters.
1985-03-01
example may be designed on a numerical basis. Also, the equivalence of this solution to the minimax solution may be analyzed numerically . Finally, in...must be such that Equation (3a) has a unique solution that is sample-path continuous, c) w must be such that the cost function, (5), is well-defined...problem can be reformulated as an optimization problem with equality constraints. 3.3. Problem Redefinition and Solution The system equations , (3
Parameter Study of the LIFE Engine Nuclear Design
Kramer, K J; Meier, W R; Latkowski, J F; Abbott, R P
2009-07-10
LLNL is developing the nuclear fusion based Laser Inertial Fusion Energy (LIFE) power plant concept. The baseline design uses a depleted uranium (DU) fission fuel blanket with a flowing molten salt coolant (flibe) that also breeds the tritium needed to sustain the fusion energy source. Indirect drive targets, similar to those that will be demonstrated on the National Ignition Facility (NIF), are ignited at {approx}13 Hz providing a 500 MW fusion source. The DU is in the form of a uranium oxycarbide kernel in modified TRISO-like fuel particles distributed in a carbon matrix forming 2-cm-diameter pebbles. The thermal power is held at 2000 MW by continuously varying the 6Li enrichment in the coolants. There are many options to be considered in the engine design including target yield, U-to-C ratio in the fuel, fission blanket thickness, etc. Here we report results of design variations and compare them in terms of various figures of merit such as time to reach a desired burnup, full-power years of operation, time and maximum burnup at power ramp down and the overall balance of plant utilization.
1995-09-01
Volume two contains calculations for: embankment design--slope stability analysis; embankment design--excavation stability; embankment design--settlement and cover cracking analysis; radon barrier design--statistical analysis of ra-226 concentrations for North Continent and Union Carbide sites; radon barrier design--RAECOM input data; radon barrier design--design thickness; and cover design--frost penetration depth.
Sample size/power calculation for stratified case-cohort design.
Hu, Wenrong; Cai, Jianwen; Zeng, Donglin
2014-10-15
The case-cohort (CC) study design usually has been used for risk factor assessment in epidemiologic studies or disease prevention trials for rare diseases. The sample size/power calculation for a stratified CC (SCC) design has not been addressed before. This article derives such result based on a stratified test statistic. Simulation studies show that the proposed test for the SCC design utilizing small sub-cohort sampling fractions is valid and efficient for situations where the disease rate is low. Furthermore, optimization of sampling in the SCC design is discussed and compared with proportional and balanced sampling techniques. An epidemiological study is provided to illustrate the sample size calculation under the SCC design. Copyright © 2014 John Wiley & Sons, Ltd.
Telemonitoring of vital parameters with newly designed biomedical clothing.
Weber, J-L; Blanc, D; Dittmar, A; Comet, B; Corroy, C; Noury, N; Baghai, R; Vaysse, S; Blinowska, A
2004-01-01
The paper describes the development of biomedical clothing for ambulatory telemonitoring of human vital parameters. VTAM (Vetement de Tele-Assistance Medicale) presents a T-shirt made from textile with woven wires and incorporating four smooth dry ECG electrodes, a breath rate sensor, a shock/fall detector and two temperature sensors. The garment is equipped for the signal pre-computing and transmission through a miniature GSM/GPRS module kept on a belt together with the power supply. Three VTAM prototypes have been tested on persons in a normal state of health using a medical protocol to assess the biomedical data that include an ECG reading, a pneumogram, temperature and fall detection in mobile situations.
Aakre, Christopher Ansel; Kitson, Jaben E; Li, Man; Herasevich, Vitaly
2017-05-18
The new sepsis definition has increased the need for frequent sequential organ failure assessment (SOFA) score recalculation and the clerical burden of information retrieval makes this score ideal for automated calculation. The aim of this study was to (1) estimate the clerical workload of manual SOFA score calculation through a time-motion analysis and (2) describe a user-centered design process for an electronic medical record (EMR) integrated, automated SOFA score calculator with subsequent usability evaluation study. First, we performed a time-motion analysis by recording time-to-task-completion for the manual calculation of 35 baseline and 35 current SOFA scores by 14 internal medicine residents over a 2-month period. Next, we used an agile development process to create a user interface for a previously developed automated SOFA score calculator. The final user interface usability was evaluated by clinician end users with the Computer Systems Usability Questionnaire. The overall mean (standard deviation, SD) time-to-complete manual SOFA score calculation time was 61.6 s (33). Among the 24% (12/50) usability survey respondents, our user-centered user interface design process resulted in >75% favorability of survey items in the domains of system usability, information quality, and interface quality. Early stakeholder engagement in our agile design process resulted in a user interface for an automated SOFA score calculator that reduced clinician workload and met clinicians' needs at the point of care. Emerging interoperable platforms may facilitate dissemination of similarly useful clinical score calculators and decision support algorithms as "apps." A user-centered design process and usability evaluation should be considered during creation of these tools.
Takeda, T.; Shimazu, Y.; Hibi, K.; Fujimura, K.
2012-07-01
Under the R and D project to improve the modeling accuracy for the design of fast breeder reactors the authors are developing a neutronics calculation method for designing a large commercial type sodium- cooled fast reactor. The calculation method is established by taking into account the special features of the reactor such as the use of annular fuel pellet, inner duct tube in large fuel assemblies, large core. The Verification and Validation, and Uncertainty Qualification (V and V and UQ) of the calculation method is being performed by using measured data from the prototype FBR Monju. The results of this project will be used in the design and analysis of the commercial type demonstration FBR, known as the Japanese Sodium fast Reactor (JSFR). (authors)
Inherent uncertainties in meteorological parameters for wind turbine design
NASA Technical Reports Server (NTRS)
Doran, J. C.
1982-01-01
Major difficulties associated with meteorological measurments such as the inability to duplicate the experimental conditions from one day to the next are discussed. This lack of consistency is compounded by the stochastic nature of many of the meteorological variables of interest. Moreover, simple relationships derived in one location may be significantly altered by topographical or synoptic differences encountered at another. The effect of such factors is a degree of inherent uncertainty if an attempt is made to describe the atmosphere in terms of universal laws. Some of these uncertainties and their causes are examined, examples are presented and some implications for wind turbine design are suggested.
Summary report for ITER Task -- D4: Activation calculations for the stainless steel ITER design
Attaya, H.
1995-02-01
Detailed activation analysis for ITER has been performed as a part of ITER Task D4. The calculations have been performed for the shielding blanket (SS/water) and for the breeding blanket (LiN) options. The activation code RACC-P, which has been modified under IFER Task-D-10 for pulsed operation, has been used in this analysis. The spatial distributions of the radioactive inventory, decay heat, biological hazard potential, and the contact dose were calculated for the two designs for different operation modes and targeted fluences. A one-dimensional toroidal geometrical model has been utilized to determine the neutron fluxes in the two designs. The results are normalized for an inboard and outboard neutron wall loadings of 0.91 and 1.2 MW/M{sup 2}, respectively. The point-wise distributions of the decay gamma sources have been calculated everywhere in the reactor at several times after the shutdown of the two designs and are then used in the transport code ONEDANT to calculate the biological dose everywhere in the reactor. The point-wise distributions of all the responses have also been calculated. These calculations have been performed for neutron fluences of 3.0 MWa/M{sup 2}, which corresponds to the target fluence of ITER, and 0.1 MWa/M{sup 2}, which is anticipated to correspond to the beginning of an extended maintenance period.
Understanding facilities design parameters for a remanufacturing system
NASA Astrophysics Data System (ADS)
Topcu, Aysegul; Cullinane, Thomas
2005-11-01
Remanufacturing is rapidly becoming a very important element in the economies of the world. Products such as washing machines, clothes driers, automobile parts, cell phones and a wide range of consumer durable goods are being reclaimed and sent through processes that restore these products to levels of operating performance that are as good or better than their new product performance. The operations involved in the remanufacturing process add several new dimensions to the work that must be performed. Disassembly is an operation that rarely appears on the operations chart of a typical production facility. The inspection and test functions in remanufacturing most often involve several more tasks than those involved in the first time manufacturing cycle. A close evaluation of most any remanufacturing operation reveals several points in the process in which parts must be cleaned, tested and stored. Although several researchers have focused their work on optimizing the disassembly function and the inspection, test and store functions, very little research has been devoted to studying the impact of the facilities design on the effectiveness of the remanufacturing process. The purpose of this paper will be to delineate the differences between first time manufacturing operations and remanufacturing operations for durable goods and to identify the features of the facilities design that must be considered if the remanufacturing operations are to be effective.
VanOsdol, J.G.; Tucker, D.A.
2006-11-01
Thermodynamic efficiency must be considered in the effective analysis of gas turbine fuel cell power generation system performance. In most numerical simulations of hybrid systems, the use of compressor maps and turbine maps are neglected. It is assumed that the design criterion generated by the system model can be met by the manufacturer of these items. These system models may use partial information from a compressor map, or a turbine map, but they fail to match all the operating conditions of both maps in a hybrid configuration. Also, to simplify the calculations that are performed by the complex hybrid system models, the effects of heat transfer and fluid dynamic drag are often decoupled. When system calculations are done in this way, the resulting calculations for system efficiency may suffer error. Hybrid system designers need a simple method to calculate the system performance directly from the maps of real compressors and real turbines that currently exist, and that would be part of a hybrid system. In this work, a simple procedure is illustrated where a coupled analysis of the various system components is performed and included as part of the system model. This analysis is done using the compressor and turbine maps of the hybrid performance project hardware at the U.S. Department of Energy, National Energy Technology Laboratory (NETL). Model parameters are tuned using experimental conditions and results are obtained. The results show the importance of aerodynamic coupling in system models, and how this coupling affects the system efficiency calculations. This coupling becomes important especially for the variable density flows that are typically found in combustors, heat exchangers and fuel cells.
NASA Astrophysics Data System (ADS)
Zheng, Y.; Hussain, Z.; Shirley, D. A.
1993-04-01
The influence of theoretical atomic scattering phase shifts calculated by different methods in the analysis in the analysis of angle-resolved photoemission extended fine structure (ARPEFS) data for structural determination of the c(2×2)S/Ni(001) surface was examined, with the goal of assessing both the precision and accuracy of derived structural parameters. It was found that the values of the SNi bond length obtained from the ARPEFS data analysis with different calculated atomic scattering phase shifts all fall within a total range of 0.02 Å (± 0.01 Å). This result is also in excellent agreement with the currently accepted values obtained from low-energy electron diffraction (LEED) and surface extended X-ray absorption fine structure (SEXAFS), i.e. 2.19-2.20 rA. We conclude that this ARPEFS-derived structural parameter is relatively insensitive to the choice of theoretical atomic scattering phase shifts, and is both precise and accurate.
Park, Byoung Yoon; Hansen, Francis D.
2004-07-01
The regulatory compliance determination for the Waste Isolation Pilot Plant includes the consideration of room closure. Elements of the geomechanical processes include salt creep, gas generation and mechanical deformation of the waste residing in the rooms. The WIPP was certified as complying with regulatory requirements based in part on the implementation of room closure and material models for the waste. Since the WIPP began receiving waste in 1999, waste packages have been identified that are appreciably more robust than the 55-gallon drums characterized for the initial calculations. The pipe overpack comprises one such waste package. This report develops material model parameters for the pipe overpack containers by using axisymmetrical finite element models. Known material properties and structural dimensions allow well constrained models to be completed for uniaxial, triaxial, and hydrostatic compression of the pipe overpack waste package. These analyses show that the pipe overpack waste package is far more rigid than the originally certified drum. The model parameters developed in this report are used subsequently to evaluate the implications to performance assessment calculations.
NASA Astrophysics Data System (ADS)
Chougale, Yashwant; Nath, Rejish
2016-07-01
We obtain ab initio the Hubbard parameters for Rydberg-dressed atoms in a one-dimensional (1D) sinusoidal optical lattice on the basis of maximally-localized Wannier states. Finite range, soft-core interatomic interactions become the trait of Rydberg admixed atoms, which can be extended over many neighboring lattice sites. In contrast to dipolar gases, where the interactions follow an inverse cubic law, the key feature of Rydberg-dressed interactions is the possibility of making neighboring couplings to the same magnitude as that of the onsite ones. The maximally-localized Wannier functions (MLWFs) are typically calculated via a spread-minimization procedure (Marzari N and Vanderbilt D 1997 Phys. Rev. B 56 12847) and are always found to be real functions apart from a trivial global phase when an isolated set of Bloch bands are considered. For an isolated single Bloch band, the above procedure reduces to a simple quasi-momentum-dependent unitary phase transformation. Here, instead of minimizing the spread, we employ a diagonal phase transformation which eliminates the imaginary part of the Wannier functions. The resulting Wannier states are found to be maximally localized and in exact agreement with those obtained via a spread-minimization procedure. Using these findings, we calculate the Hubbard couplings from the Rydberg admixed interactions, including dominant density-assisted tunneling (DAT) coefficients. Finally, we provide realistic lattice parameters for the state-of-the-art experimental Rydberg-dressed rubidium setup.
Optimum design calculations for detectors based on ZnSe(Те,О) scintillators
NASA Astrophysics Data System (ADS)
Katrunov, K.; Ryzhikov, V.; Gavrilyuk, V.; Naydenov, S.; Lysetska, O.; Litichevskyi, V.
2013-06-01
Light collection in scintillators ZnSe(X), where X is an isovalent dopant, was studied using Monte Carlo calculations. Optimum design was determined for detectors of "scintillator—Si-photodiode" type, which can involve either one scintillation element or scintillation layers of large area made of small-crystalline grains. The calculations were carried out both for determination of the optimum scintillator shape and for design optimization of light guides, on the surface of which the layer of small-crystalline grains is formed.
NASA Astrophysics Data System (ADS)
Nikezic, D.; Yu, K. N.
2006-01-01
A computer program called TRACK_TEST for calculating parameters (lengths of the major and minor axes) and plotting profiles in nuclear track materials resulted from light-ion irradiation and subsequent chemical etching is described. The programming steps are outlined, including calculations of alpha-particle ranges, determination of the distance along the particle trajectory penetrated by the chemical etchant, calculations of track coordinates, determination of the lengths of the major and minor axes and determination of the contour of the track opening. Descriptions of the program are given, including the built-in V functions for the two commonly employed nuclear track materials commercially known as LR 115 (cellulose nitrate) and CR-39 (poly allyl diglycol carbonate) irradiated by alpha particles. Program summaryTitle of the program:TRACK_TEST Catalogue identifier:ADWT Program obtainable from:CPC Program Library, Queen's University of Belfast, N. Ireland Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWT Computer:Pentium PC Operating systems:Windows 95+ Programming language:Fortran 90 Memory required to execute with typical data:256 MB No. of lines in distributed program, including test data, etc.: 2739 No. of bytes in distributed program, including test data, etc.:204 526 Distribution format:tar.gz External subprograms used:The entire code must be linked with the MSFLIB library Nature of problem: Fast heavy charged particles (like alpha particles and other light ions etc.) create latent tracks in some dielectric materials. After chemical etching in aqueous NaOH or KOH solutions, these tracks become visible under an optical microscope. The growth of a track is based on the simultaneous actions of the etchant on undamaged regions (with the bulk etch rate V) and along the particle track (with the track etch rate V). Growth of the track is described satisfactorily by these two parameters ( V and V). Several models have been presented in the past describing
Sensitivity of optimum solutions to problem parameters. [in aircraft design
NASA Technical Reports Server (NTRS)
Sobieszczanski-Sobieski, J.; Riley, K. M.; Barthelemy, J.-F.
1981-01-01
In an aircraft configuration optimization, the information of interest is the sensitivity of optimal block fuel consumption and wing aspect ratio and area, to variations of required range and payload. The objectives of this study are: (1) to show how the equations capable of yielding the sensitivity derivatives (the sensitivity equations) can be obtained for a constrained optimum regardless of the type of optimization algorithm that was used to arrive at the optimum point, (2) to review the solvability of the sensitivity equations and (3) to report on applications on structural optimization. Numerical examples, which demonstrate the sensitivity analysis, include a tubular column and a three-bar truss for which closed form solutions are obtained, a ten-bar truss that requires the use of a finite element analysis, and a thin-walled beam characterized by strongly nonlinear constraints for local buckling. It is concluded that a practically significant extrapolation accuracy may be obtained for a reasonably broad range of parameter changes; and that accuracy does not depend strongly on the degree of convergence of the optimum solution from which the sensitivity derivatives are obtained.
Design parameters for carbon nanobottles to absorb and store methane.
Lee, Richard K F; Hill, James M
2011-08-01
We investigate the internal mechanics for methane storage in a nanobottle, which is assumed to comprise a metallofullerene located inside a carbon nanobottle, which is constructed from a half-fullerene as the base, and two nanotubes which are joined by a nanocone. The interaction potential energy for the metallofullerene is obtained from the 6-12 Lennard-Jones potential and the continuum approximation, which assumes that a discrete atomic structure can be replaced by an average atomic surface density. This potential energy shows that the metallofullerene has two minimum energy positions, which are located close to the neck of the bottle and at the base of the nanobottle, and therefore it may be used as a bottle-stopper to open or to close the nanobottle. At the neck of the bottle, the encapsulated metallofullerene closes the nanobottle, and by applying an external electrical force, the metallofullerene can overcome the energy barrier of the nanotube, and pass from the neck of the nanobottle to the base so that the nanobottle is open. For methane storage, the metallofullerene serves the dual purposes of opening and closing the nanobottle, as well as an attractor for the methane gas. The analytical formulation gives rise to a rapid computational capacity, and enables the direct determination of the optimal dimensions necessary to ensure the correct working function of the nanobottle, and specific ranges for the critical parameters are formulated.
Learning Effects in the Block Design Task: A Stimulus Parameter-Based Approach
ERIC Educational Resources Information Center
Miller, Joseph C.; Ruthig, Joelle C.; Bradley, April R.; Wise, Richard A.; Pedersen, Heather A.; Ellison, Jo M.
2009-01-01
Learning effects were assessed for the block design (BD) task, on the basis of variation in 2 stimulus parameters: perceptual cohesiveness (PC) and set size uncertainty (U). Thirty-one nonclinical undergraduate students (19 female) each completed 3 designs for each of 4 varied sets of the stimulus parameters (high-PC/high-U, high-PC/low-U,…
Optimization of design parameters of low-energy buildings
NASA Astrophysics Data System (ADS)
Vala, Jiří; Jarošová, Petra
2017-07-01
Evaluation of temperature development and related consumption of energy required for heating, air-conditioning, etc. in low-energy buildings requires the proper physical analysis, covering heat conduction, convection and radiation, including beam and diffusive components of solar radiation, on all building parts and interfaces. The system approach and the Fourier multiplicative decomposition together with the finite element technique offers the possibility of inexpensive and robust numerical and computational analysis of corresponding direct problems, as well as of the optimization ones with several design variables, using the Nelder-Mead simplex method. The practical example demonstrates the correlation between such numerical simulations and the time series of measurements of energy consumption on a small family house in Ostrov u Macochy (35 km northern from Brno).
The Design Parameters for the MICE Tracker Solenoid
Green, Michael A.; Chen, C.Y.; Juang, Tiki; Lau, Wing W.; Taylor,Clyde; Virostek, Steve P.; Wahrer, Robert; Wang, S.T.; Witte, Holger; Yang, Stephanie Q.
2006-08-20
The first superconducting magnets to be installed in the muon ionization cooling experiment (MICE) will be the tracker solenoids. The tracker solenoid module is a five coil superconducting solenoid with a 400 mm diameter warm bore that is used to provide a 4 T magnetic field for the experiment tracker module. Three of the coils are used to produce a uniform field (up to 4 T with better than 1 percent uniformity) in a region that is 300 mm in diameter and 1000 mm long. The other two coils are used to match the muon beam into the MICE cooling channel. Two 2.94-meter long superconducting tracker solenoid modules have been ordered for MICE. The tracker solenoid will be cooled using two-coolers that produce 1.5 W each at 4.2 K. The magnet system is described. The decisions that drive the magnet design will be discussed in this report.
Influence of design parameters on occurence of oil whirl
NASA Technical Reports Server (NTRS)
Ogrodnik, P. J.; Goodwin, M. J.; Penny, J. E. T.
1985-01-01
Oil whirl instability is a serious problem in oil lubricated journal bearings. The phenomenon is characterized by a subsynchronous vibration of the journal within the bush and is particularly apparent in turbogenerators, aeroengines and electric motors. A review is presented of previous papers on the subject of oil whirl, and a simple theory is described which was used to aid the design of an oil whirl test rig. Predictions of the onset of oil whirl made by the theory presented were found to agree with those of previous researchers. They showed that increasing the shaft flexibility, or the lubricant viscosity, and decreasing the bearing radial clearance tended to reduce the oil whirl onset speed thus making the system more unstable.
NASA Technical Reports Server (NTRS)
Hyland, D. C.
1983-01-01
A stochastic structural control model is described. In contrast to the customary deterministic model, the stochastic minimum data/maximum entropy model directly incorporates the least possible a priori parameter information. The approach is to adopt this model as the basic design model, thus incorporating the effects of parameter uncertainty at a fundamental level, and design mean-square optimal controls (that is, choose the control law to minimize the average of a quadratic performance index over the parameter ensemble).
Computer calculations of wire-rope tiedown designs for radioactive materials packages
Shappert, L.B.; Ratledge, J.E.; Moore, R.S.; Dorsey, E.A.
1995-12-31
This Regulatory Compliance Guide (RCG) provides guidance on the use and selection of appropriate wire rope type package tiedowns. It provides an effective way to encourage and to ensure uniform implementation of regulatory requirements applicable to tiedowns. It provides general guidelines for securing packages weighing 5,000 pounds or greater that contain radioactive materials onto legal weight trucks (exclusive of packagings having their own trailer with trunnion type tiedown). This RCG includes a computerized Tiedown Stress Calculation Program (TSCP) which calculates the stresses in the wire-rope tiedowns and specifies appropriate sizes of wire rope and associated hardware parameters (such as turnback length, number of cable clips, etc.).
NASA Astrophysics Data System (ADS)
Grofulović, M.; Pinhão, N.; Alves, Ll; Guerra, V.; Loffhagen, D.; Korolov, I.; Vass, M.; Donkó, Z.
2016-09-01
The plasma-based CO2 conversion is a promising route for achieving the reduction of fossil fuel consumption and of CO2 emission. An accurate description of the electron kinetics by solving the electron Boltzmann equation (EBE) is necessary for this application. This work is dedicated to the inter-comparison between various calculation techniques of the EBE (two-term, multi-term and space gradients of the electron density) and the Monte-Carlo reference technique for the analysis of swarm parameters and their comparison with previously available and present experimental data. We adopt the complete set of electron-impact cross sections for CO2, to be published on the IST-LISBON database with LXCat. Results show that despite the fact that the IST-LISBON cross sections were derived to fit measured swarm parameters when used in a two-term expansion Boltzmann code, good agreement with the other solution and simulation techniques is generally obtained for the electron swarm parameters under consideration. Work partially supported by grant OTKA-K-105476 and by Portuguese FCT, under project UID/FIS/50010/2013 and grant PD/BD/105884/2014 (PD-F APPLAuSE).
Use precise calculation models to operate or design refinery gas treating systems
1996-07-01
Amine simulators using rate-based calculation methodology can show refinery operators how to treat more acid gas with existing equipment. These simulators can rate the performance and design of an existing unit by evaluating tray size, downcomer configuration, column diameter, wier height, tray depth and operation with a particular solvent. In addition, these simulators can optimize plant designers` solvent selection and equipment sizing in grassroots applications.
NASA Astrophysics Data System (ADS)
Dioguardi, Fabio; Dellino, Pierfrancesco
2014-05-01
PYFLOW is a computer code designed for quantifying the hazard related to Dilute Pyroclastic Density Currents (DPDC). DPDCs are multiphase flows that form during explosive volcanic eruptions. They are the major source of hazard related to volcanic eruptions, as they exert a significant stress over buildings and transport significant amounts of volcanic ash, which is hot and unbreathable. The program calculates the DPDC's impact parameters (e.g. dynamic pressure and particle volumetric concentration) and is founded on the turbulent boundary layer theory adapted to a multiphase framework. Fluid-dynamic variables are searched with a probabilistic approach, meaning that for each variable the average, maximum and minimum solutions are calculated. From these values, PYFLOW creates probability functions that allow to calculate the parameter at a given percentile. The code is written in Fortran 90 and can be compiled and installed on Windows, Mac OS X, Linux operating systems (OS). A User's manual is provided, explaining the details of the theoretical background, the setup and running procedure and the input data. The model inputs are DPDC deposits data, e.g. particle grainsize, layer thickness, particles shape factor and density. PYFLOW reads input data from a specifically designed input file or from the user's direct typing by command lines. Guidelines for writing input data are also contained in the package. PYFLOW guides the user at each step of execution, asking for additional data and inputs. The program is a tool for DPDC hazard assessment and, as an example, an application to the DPDC deposits of the Agnano-Monte Spina eruption (4.1 ky BP) at Campi Flegrei (Italy) is presented.
Filho, Manoel A. M.; Dutra, José Diogo L.; Rocha, Gerd B.; Simas, Alfredo M.
2016-01-01
The RM1 quantum chemical model for the calculation of complexes of Tm(III), Yb(III) and Lu(III) is advanced. Subsequently, we tested the models by fully optimizing the geometries of 126 complexes. We then compared the optimized structures with known crystallographic ones from the Cambridge Structural Database. Results indicate that, for thulium complexes, the accuracy in terms of the distances between the lanthanide ion and its directly coordinated atoms is about 2%. Corresponding results for ytterbium and lutetium are both 3%, levels of accuracy useful for the design of lanthanide complexes, targeting their countless applications. PMID:27223475
Filho, Manoel A M; Dutra, José Diogo L; Rocha, Gerd B; Simas, Alfredo M; Freire, Ricardo O
2016-01-01
The RM1 quantum chemical model for the calculation of complexes of Tm(III), Yb(III) and Lu(III) is advanced. Subsequently, we tested the models by fully optimizing the geometries of 126 complexes. We then compared the optimized structures with known crystallographic ones from the Cambridge Structural Database. Results indicate that, for thulium complexes, the accuracy in terms of the distances between the lanthanide ion and its directly coordinated atoms is about 2%. Corresponding results for ytterbium and lutetium are both 3%, levels of accuracy useful for the design of lanthanide complexes, targeting their countless applications.
NASA Astrophysics Data System (ADS)
Reimer, Joscha; Piwonski, Jaroslaw; Slawig, Thomas
2016-04-01
The statistical significance of any model-data comparison strongly depends on the quality of the used data and the criterion used to measure the model-to-data misfit. The statistical properties (such as mean values, variances and covariances) of the data should be taken into account by choosing a criterion as, e.g., ordinary, weighted or generalized least squares. Moreover, the criterion can be restricted onto regions or model quantities which are of special interest. This choice influences the quality of the model output (also for not measured quantities) and the results of a parameter estimation or optimization process. We have estimated the parameters of a three-dimensional and time-dependent marine biogeochemical model describing the phosphorus cycle in the ocean. For this purpose, we have developed a statistical model for measurements of phosphate and dissolved organic phosphorus. This statistical model includes variances and correlations varying with time and location of the measurements. We compared the obtained estimations of model output and parameters for different criteria. Another question is if (and which) further measurements would increase the model's quality at all. Using experimental design criteria, the information content of measurements can be quantified. This may refer to the uncertainty in unknown model parameters as well as the uncertainty regarding which model is closer to reality. By (another) optimization, optimal measurement properties such as locations, time instants and quantities to be measured can be identified. We have optimized such properties for additional measurement for the parameter estimation of the marine biogeochemical model. For this purpose, we have quantified the uncertainty in the optimal model parameters and the model output itself regarding the uncertainty in the measurement data using the (Fisher) information matrix. Furthermore, we have calculated the uncertainty reduction by additional measurements depending on time
Mueller-Hoeppe, N.; Engelmann, H.J.; Biurrun, E.
1994-12-31
When designing a final repository for heat generating radioactive waste in rock salt, the temperature increase is of great importance with respect to the stability and long term safety of the repository. A highly efficient temperature calculation computer code is available which is verified and validated.
Shi, Mingren; Renton, Michael
2011-10-01
Computational simulation models can provide a way of understanding and predicting insect population dynamics and evolution of resistance, but the usefulness of such models depends on generating or estimating the values of key parameters. In this paper, we describe four numerical algorithms generating or estimating key parameters for simulating four different processes within such models. First, we describe a novel method to generate an offspring genotype table for one- or two-locus genetic models for simulating evolution of resistance, and how this method can be extended to create offspring genotype tables for models with more than two loci. Second, we describe how we use a generalized inverse matrix to find a least-squares solution to an over-determined linear system for estimation of parameters in probit models of kill rates. This algorithm can also be used for the estimation of parameters of Freundlich adsorption isotherms. Third, we describe a simple algorithm to randomly select initial frequencies of genotypes either without any special constraints or with some pre-selected frequencies. Also we give a simple method to calculate the "stable" Hardy-Weinberg equilibrium proportions that would result from these initial frequencies. Fourth we describe how the problem of estimating the intrinsic rate of natural increase of a population can be converted to a root-finding problem and how the bisection algorithm can then be used to find the rate. We implemented all these algorithms using MATLAB and Python code; the key statements in both codes consist of only a few commands and are given in the appendices. The results of numerical experiments are also provided to demonstrate that our algorithms are valid and efficient.
Hartt, W.H.
1999-07-01
The recently developed slope parameter approach to design of galvanic anode cathodic protection (cp) systems for marine structures constitutes an advancement in this technology compared to current practice, primarily because the former is first principles based and the latter is an empirical algorithm. In this paper, the slope parameter approach is reviewed; and related applications for which it can be utilized, including (1) design of new and retrofit cp systems, (2) evaluation of potential survey data, and (3) cp system design for complex geometries, are mentioned. The design current density is identified as the single remaining parameter for which values must be projected solely by experience or experimentation. In addition, the slope parameter approach is applied to the results of impressed current cp experiments, and it is shown how parameters for this can be interrelated with those of galvanic anode cp. Advantages of this capability are identified and discussed.
Stamateris, B.; Olivera-Fuentes, C.
1996-12-31
A new procedure is proposed for the calculation and correlation of cohesion parameters in cubic equations of state of the Van der Waals type. In this method, the derivative (rather than the function itself) is computed subject to the Maxwell (equal area) and Clapeyron equations. Strong experimental evidence indicates that properly formulated a functions must generate negative values at high temperatures. A theoretical analysis demonstrates the correct, hard-body limiting behavior of the cohesion function at infinite temperatures. From this, the simplest possible form of the cohesion function follows as a two-constant expression that can be considered an extension of a functional form previously proposed by Martin. The proposed function`s performance is comparable to more complex expressions previously presented in the literature, predicting vapor pressures of polar and nonpolar fluids with relative deviations (i) of {+-} 1%. 14 refs., 2 figs., 1 tab.
Waveguide Parameter Design of Graded-Index Plastic Optical Fibers for Bending-Loss Reduction
NASA Astrophysics Data System (ADS)
Makino, Kenji; Ishigure, Takaaki; Koike, Yasuhiro
2006-05-01
The waveguide structure of graded-index plastic optical fibers (GI POFs), such as index profile, numerical aperture (NA), and core diameter, is appropriately designed for eliminating bending losses, even under a severe bending condition. The bending loss of GI POFs under a severe bending condition is drastically reduced when the core diameter is smaller than 200 µm and when the NA is higher than 0.25. The bending loss of GI POFs even under a severe bending condition vanishes with a core diameter of 200 µm and an NA of 0.24. It is experimentally confirmed for the first time that the mode coupling due to the bending induces the bending loss. The mode coupling strength before the fiber is bent affects the bending loss seriously. Moreover, the mode-coupling strength is evaluated by the propagation constant difference Δβ between the adjacent modes. The Δβ value, which is a function of the core diameter and NA, affects the bending loss. Therefore, based on the calculation of the Δβ, we propose a guideline for the appropriate design of waveguide parameters for GI POF, in order to suppress the bending loss.
NASA Technical Reports Server (NTRS)
Deligiannis, F.; Perrone, D.; DiStefano, S.
1996-01-01
Simulation of spacecraft battery operation is implemented. Robust design experiment to obtain optimum battery operational parameters is performed. It is found that short term tests using robust design of experiments can provide guidelines for optimum battery operation. It is decided to use robust design approach to provide guidelines for battery operation on current spacecraft in orbit as batteries age (GRO, UARS, EUVE, TOPEX).
Deligiannis, F.; Perrone, D.; Distefano, S.
1996-02-01
Simulation of spacecraft battery operation is implemented. Robust design experiment to obtain optimum battery operational parameters is performed. It is found that short term tests using robust design of experiments can provide guidelines for optimum battery operation. It is decided to use robust design approach to provide guidelines for battery operation on current spacecraft in orbit as batteries age (GRO, UARS, EUVE, TOPEX).
NASA Technical Reports Server (NTRS)
Deligiannis, F.; Perrone, D.; DiStefano, S.
1996-01-01
Simulation of spacecraft battery operation is implemented. Robust design experiment to obtain optimum battery operational parameters is performed. It is found that short term tests using robust design of experiments can provide guidelines for optimum battery operation. It is decided to use robust design approach to provide guidelines for battery operation on current spacecraft in orbit as batteries age (GRO, UARS, EUVE, TOPEX).
NASA Astrophysics Data System (ADS)
Petersen, Spencer J.; Basu, Soumyadipta; Raeymaekers, Bart; Francoeur, Mathieu
2013-11-01
The possibility of engineering near-field thermal radiative properties is investigated by adjusting design parameters of Mie resonance-based metamaterials. The sensitivities of surface polariton resonance frequencies, in both transverse magnetic and transverse electric polarizations, to parameters such as host medium relative permittivity and particle size and spacing (volume filling fraction) is determined. The sensitivity analysis is performed using a design of experiments method in combination with Mie resonance calculations and Clausius-Mossotti mixing relations. Particle size has the greatest effect on the resonance frequencies, while the volume filling fraction has the least. Based on the results from the sensitivity analysis, three metamaterials are selected for further analysis. The physics of these metamaterials is explored by calculating local density of electromagnetic states and surface polariton dispersion relation. As predicted by the sensitivity analysis, the local density of electromagnetic states and dispersion relation calculations show that Mie resonance-based metamaterials can be tuned to exhibit surface polariton resonance in the near-infrared spectrum. Energy density calculations show that surface polariton resonance in the near-infrared can be activated at temperatures as low as 800 K. Finally, a pathway to implementation of these metamaterials into macroscale engineering applications is proposed. Such metamaterials, with near-infrared surface polariton resonance, will significantly impact the development of nanoscale-gap thermophotovoltaic power generators for recycling waste heat into electricity.
Ye, Lin; Su, Steven W
2015-01-01
Optimum Experimental Design (OED) is an information gathering technique used to estimate parameters, which aims to minimize the variance of parameter estimation and prediction. In this paper, we further investigate an OED for MEMS accelerometer calibration of the 9-parameter auto-calibration model. Based on a linearized 9-parameter accelerometer model, we show the proposed OED is both G-optimal and rotatable, which are the desired properties for the calibration of wearable sensors for which only simple calibration devices are available. The experimental design is carried out with a newly developed wearable health monitoring device and desired experimental results have been achieved.
Effect of Design Changes On Remote Handled Trench Waste Form Release Calculations
Bacon, Diana H.; McGrail, B. Peter
2002-09-20
A set of reactive chemical transport calculations was conducted with the Subsurface Transport Over Reactive Multi-phases (STORM) code to evaluate the long-term performance of a representative low-activity waste glass in a shallow subsurface disposal system located on the Hanford Site. One-dimensional simulations were conducted out to times of 20,000 yr. The simulations predict a lower release rate for the new trench design (0.605 ppm/yr) than for the old trench design (0.726 ppm/yr). Because the glass corrosion rate is significantly higher at the backfill/glass interfaces, having one less interface with the 3-layer design offsets the effect of the slightly higher pH relative to the 4-layer design. The differences between the old and new trench designs were much less significant than differences due to differences in recharge rate.
Kaiser, Reinhard; Woodruff, Bradley A; Bilukha, Oleg; Spiegel, Paul B; Salama, Peter
2006-06-01
A good estimate of the design effect is critical for calculating the most efficient sample size for cluster surveys. We reviewed the design effects for seven nutrition and health outcomes from nine population-based cluster surveys conducted in emergency settings. Most of the design effects for outcomes in children, and one-half of the design effects for crude mortality, were below two. A reassessment of mortality data from Kosovo and Badghis, Afghanistan revealed that, given the same number of clusters, changing sample size had a relatively small impact on the precision of the estimate of mortality. We concluded that, in most surveys, assuming a design effect of 1.5 for acute malnutrition in children and two or less for crude mortality would produce a more efficient sample size. In addition, enhancing the sample size in cluster surveys without increasing the number of clusters may not result in substantial improvements in precision.
Bondarenko, Evgenii A
2011-09-30
Based on the analysis of a well-known system of equations describing the dynamics of a two-isotope laser gyro with an equal-Q resonator under conditions of its fine-tuning to the centre of the emission line and balanced currents in the discharge arms, we have derived the formulas for calculating the parameters of the synchronisation zone for the frequencies of counterpropagating electromagnetic waves generated in the device. The formulas make it possible to calculate the coordinates on the axis of the angular velocity of the left and right boundaries of the synchronisation zone, the coordinate of its centre and half-width. It follows from the analysis that, in the general case of the asymmetric linear coupling between the counterpropagating waves via backscattering, absorption, and transmission of radiation from the mirrors of the gyro, the left and right boundaries of the synchronisation zone are located at different distances with respect to the origin of coordinates, so that the centre of the region is displaced along the axis of the angular velocity. The analysis of the formulas also implies that the shift of the centre of the synchronisation zone and its half-width decrease with increasing medium gain.
NASA Astrophysics Data System (ADS)
Feshin, V. P.; Feshina, E. V.
2012-03-01
The results of ab initio calculations at the RHF/6-31G(d) and MP2/6-31G(d) levels of two stable structures of the 4-(trichlorgermyl)butan-2-one molecule with total optimization of their geometry have been represented. The structure with pentacoordinated Ge atom is energetically more advantageous as compared with that with tetracoordinated one. Using these results, the 35Cl nuclear quadrupole resonance (NQR) frequencies and asymmetry parameters of the electric field gradient (EFG) at the 35Cl nuclei in molecule with pentacoordinated Ge atom have been assessed, the frequencies satisfactorily agreeing with experimental data. Calculations at the RHF/6-31G(d) level have been performed also at various Ge⋯O distances. It has been demonstrated that convergence of the Ge and O coordination centers leads to the increase of positive charge at the Ge coordination center and of negative charge at the O coordination center, at that, electron density from the Ge atom shifts mainly to the axial Cl atom and from the C atom of carbonyl group - to its O atom. The electron density transfer from the O to Ge atom does not occur.
Design of new face-centered cubic high entropy alloys by thermodynamic calculation
NASA Astrophysics Data System (ADS)
Choi, Won-Mi; Jung, Seungmun; Jo, Yong Hee; Lee, Sunghak; Lee, Byeong-Joo
2017-09-01
A new face-centered cubic (fcc) high entropy alloy system with non-equiatomic compositions has been designed by utilizing a CALculation of PHAse Diagram (CALPHAD) - type thermodynamic calculation technique. The new alloy system is based on the representative fcc high entropy alloy, the Cantor alloy which is an equiatomic Co- Cr-Fe-Mn-Ni five-component alloy, but fully or partly replace the cobalt by vanadium and is of non-equiatomic compositions. Alloy compositions expected to have an fcc single-phase structure between 700 °C and melting temperatures are proposed. All the proposed alloys are experimentally confirmed to have the fcc single-phase during materials processes (> 800 °C), through an X-ray diffraction analysis. It is shown that there are more chances to find fcc single-phase high entropy alloys if paying attention to non-equiatomic composition regions and that the CALPHAD thermodynamic calculation can be an efficient tool for it. An alloy design technique based on thermodynamic calculation is demonstrated and the applicability and limitation of the approach as a design tool for high entropy alloys is discussed.
NASA Technical Reports Server (NTRS)
Sandlin, Doral R.; Swanson, Stephen Mark
1990-01-01
The creation of a computer module used to calculate the size of the horizontal control surfaces of a conceptual aircraft design is discussed. The control surface size is determined by first calculating the size needed to rotate the aircraft during takeoff, and, second, by determining if the calculated size is large enough to maintain stability of the aircraft throughout any specified mission. The tail size needed to rotate during takeoff is calculated from a summation of forces about the main landing gear of the aircraft. The stability of the aircraft is determined from a summation of forces about the center of gravity during different phases of the aircraft's flight. Included in the horizontal control surface analysis are: downwash effects on an aft tail, upwash effects on a forward canard, and effects due to flight in close proximity to the ground. Comparisons of production aircraft with numerical models show good accuracy for control surface sizing. A modified canard design verified the accuracy of the module for canard configurations. Added to this stability and control module is a subroutine that determines one of the three design variables, for a stable vectored thrust aircraft. These include forward thrust nozzle position, aft thrust nozzle angle, and forward thrust split.
Murase, Kenya
2004-04-01
It has become increasingly important to quantitatively estimate tissue physiological parameters such as perfusion, capillary permeability, and the volume of extravascular-extracellular space (EES) using T(1)-weighted dynamic contrast-enhanced MRI (DCE-MRI). A linear equation was derived by integrating the differential equation describing the kinetic behavior of contrast agent (CA) in tissue, from which K(1) (rate constant for the transfer of CA from plasma to EES), k(2) (rate constant for the transfer from EES to plasma), and V(p) (plasma volume) can be easily obtained by the linear least-squares (LLSQ) method. The usefulness of this method was investigated by means of computer simulations, in comparison with the nonlinear least-squares (NLSQ) method. The new method calculated the above parameters faster than the NLSQ method by a factor of approximately 6, and estimated them more accurately than the NLSQ method at a signal-to-noise ratio (SNR) of < approximately 10. This method will be useful for generating functional images of K(1), k(2), and V(p) from DCE-MRI data.
Parameter-Level Data Flow Modeling Oriented to Product Design Process
NASA Astrophysics Data System (ADS)
Li, Shen; Shao, Xiao Dong; Zhang, Zhi Hua; Ge, Xiao Bo
2015-12-01
In this paper, a method of data flow modeling for a product design process oriented to data parameter is proposed. The data parameters are defined, which are classified as the basic data parameters and complex data parameters. The mechanism of the mapping relationship between different forms of documents and some basic data parameters, and a data transmission based on parameters, are constructed. Aiming at the characteristics of the iterative design process, the parameters version mechanism including node modification and iteration information is proposed. The data parameters transmission relationships are represented by a parameters network model (PNM) based on a directed graph. Finally, through the table of data parameters mapping onto the workflow node and PNM, the data ports and data links in the data flow model are generated automatically by the program. Validation in the 15-meter-diameter S/Ka frequency band antenna design process of the “Reflector, Back frame and Center part design” data flow model shows that the method can effectively shorten the time of data flow modeling and improve the data transmission efficiency.
NASA Astrophysics Data System (ADS)
Shirasawa, Naoya; Takigawa, Yorinobu; Uesugi, Tokuteru; Higashi, Kenji
2016-01-01
The effect of alloying on the formation enthalpy of TiCu intermetallics was investigated via first-principles calculations to propose a new design method for Ti-Cu-system metallic glasses. The calculation results showed good agreement with the reported experimental results that Ni, Pd, Sn and Zr improve this system's glass-forming ability. According to the calculation results, a Ti-Zr-Cu-Ga system was designed as a potential new bulk Ti-based metallic glass, and a bulk sample with a 2-mm diameter was fabricated.
Review & Peer Review of “Parameters for Properly Designed and Operated Flares” Documents
This page contains two 2012 memoranda on the review of EPA's parameters for properly designed and operated flares. One details the process of peer review, and the other provides background information and specific charge questions to the panel.
NASA Astrophysics Data System (ADS)
Su, M.; Zhang, Y. X.; Zhang, J. Y.; Hou, H. C.
2016-05-01
According to the basic parameters of 211-80 high specific speed mixed-flow pump, based on the quasi-three dimensional flow theory, the hydraulic design of impeller and its matching spaced guide vanes for high specific speed mixed flow pump was completed, in which the iterative calculation of S 1, S 2 stream surfaces was employed to obtain meridional flow fields and the point-by-point integration method was employed to draw blade camber lines. Blades are thickened as well as blade leading edges are smoothed in the conformal mapping surface. Subsequently the internal fields of the whole flow passage of the designed pump were simulated by using RANS equations with RNG k-ε two-equation turbulent model. The results show that, compared with the 211-80 model, the hydraulic efficiency of the designed pump at the optimal flow rate increases 9.1%. The hydraulic efficiency of designed pump in low flow rate condition (78% designed flow rate) increases 6.46%. The hydraulic efficiency in high flow rate areas increases obviously and there is no bad phenomenon of suddenly decrease of hydraulic efficiency in model pump. From the distributions of velocity and pressure fields, it can be seen that the flow in impeller is uniform and the increase of pressure is gentle. There are no obvious impact phenomenon on impeller inlet and obvious wake shedding vortex phenomenon from impeller outlet to guide vanes inlet.
Detailed heat load calculations for the conceptual design of the Advanced Neutron Source reactor
Wemple, C.A.
1993-12-01
A very detailed MCNP model of the Advanced Neutron Source reactor has been developed at Idaho National Engineering Laboratory. All reactor components inside the reflector vessel were included, and al components were highly segmented. Specific heat loads (watts per gram) have been calculated for each segment in the model, and system-integrated total powers are compared with the design value for the total reactor fission power. The calculated results agree very well with the design values. Axial profiles of the heat loads are provided for all components of the reactor. Individual segment statistical uncertainties were limited wherever possible, and the heat loads for all important reflector components have a standard deviation below 5%.
Proposed design of SAMUS (small angle muon spectrometer) toroid and its magnetic field calculation
Yamada, R.
1988-06-09
Presently the D/null/ detector has three big toroidal magnets; one Central Toroid (CF) and two End Wall Toroids (EF). The EF toroids have central openings 72'' x 72''. Originally, this opening was meant for possible future end-plug calorimeters. Instead we are now designing Small Angle Muon Spectrometer (SAMUS) for the opening. The major component will be built at Serpukhov. The design of the toroid magnets and its magnetic field calculations is being done by exchanging information between Serpukhov and Fermilab. 2 refs., 4 figs., 1 tab.
Van Derlinden, E; Bernaerts, K; Van Impe, J F
2010-05-21
Optimal experiment design for parameter estimation (OED/PE) has become a popular tool for efficient and accurate estimation of kinetic model parameters. When the kinetic model under study encloses multiple parameters, different optimization strategies can be constructed. The most straightforward approach is to estimate all parameters simultaneously from one optimal experiment (single OED/PE strategy). However, due to the complexity of the optimization problem or the stringent limitations on the system's dynamics, the experimental information can be limited and parameter estimation convergence problems can arise. As an alternative, we propose to reduce the optimization problem to a series of two-parameter estimation problems, i.e., an optimal experiment is designed for a combination of two parameters while presuming the other parameters known. Two different approaches can be followed: (i) all two-parameter optimal experiments are designed based on identical initial parameter estimates and parameters are estimated simultaneously from all resulting experimental data (global OED/PE strategy), and (ii) optimal experiments are calculated and implemented sequentially whereby the parameter values are updated intermediately (sequential OED/PE strategy). This work exploits OED/PE for the identification of the Cardinal Temperature Model with Inflection (CTMI) (Rosso et al., 1993). This kinetic model describes the effect of temperature on the microbial growth rate and encloses four parameters. The three OED/PE strategies are considered and the impact of the OED/PE design strategy on the accuracy of the CTMI parameter estimation is evaluated. Based on a simulation study, it is observed that the parameter values derived from the sequential approach deviate more from the true parameters than the single and global strategy estimates. The single and global OED/PE strategies are further compared based on experimental data obtained from design implementation in a bioreactor
2008-01-01
Am. Ind. Hyg. Assoc. J. 1992, 53, pp 193-202. 4. Letowski, T.R.; Ricard, G.L.; Grieves, J.E. The Effect of the XM45 Gas Mask and Hood on Directional...Historical mask wear human performance research offers useful, albeit limited, insights on the relationships between design parameters and performance. The...purposes of the current task were to review and revise the existing human performance capabilities and mask design parameters databases and to derive new
Design and Properties Prediction of AMCO3F by First-Principles Calculations.
Tian, Meng; Gao, Yurui; Ouyang, Chuying; Wang, Zhaoxiang; Chen, Liquan
2017-04-19
Computer simulation accelerates the rate of identification and application of new materials. To search for new materials to meet the increasing demands of secondary batteries with higher energy density, the properties of some transition-metal fluorocarbonates ([CO3F](3-)) were simulated in this work as cathode materials for Li- and Na-ion batteries based on first-principles calculations. These materials were designed by substituting the K(+) ions in KCuCO3F with Li(+) or Na(+) ions and the Cu(2+) ions with transition-metal ions such as Fe(2+), Co(2+), Ni(2+), and Mn(2+) ions, respectively. The phase stability, electronic conductivity, ionic diffusion, and electrochemical potential of these materials were calculated by first-principles calculations. After taking comprehensive consideration of the kinetic and thermodynamic properties, LiCoCO3F and LiFeCO3F are believed to be promising novel cathode materials in all of the calculated AMCO3F (A = Li and Na; M = Fe, Mn, Co, and Ni). These results will help the design and discovery of new materials for secondary batteries.
Parameter uncertainties in the design and optimization of cantilever piezoelectric energy harvesters
NASA Astrophysics Data System (ADS)
Franco, V. R.; Varoto, P. S.
2017-09-01
A crucial issue in piezoelectric energy harvesting is the efficiency of the mechanical to electrical conversion process. Several techniques have been investigated in order to obtain a set of optimum design parameters that will lead to the best performance of the harvester in terms of electrical power generation. Once an optimum design is reached it is also important to consider uncertainties in the selected parameters that in turn can lead to loss of performance in the energy conversion process. The main goal of this paper is to perform a comprehensive discussion of the effects of multi-parameter aleatory uncertainties on the performance and design optimization of a given energy harvesting system. For that, a typical energy harvester consisting of a cantilever beam carrying a tip mass and partially covered by piezoelectric layers on top and bottom surfaces is considered. A distributed parameter electromechanical modal of the harvesting system is formulated and validated through experimental tests. First, the SQP (Sequential Quadratic Planning) optimization is employed to obtain an optimum set of parameters that will lead to best performance of the harvester. Second, once the optimum harvester configuration is found random perturbations are introduced in the key parameters and Monte Carlo simulations are performed to investigate how these uncertainties propagate and affect the performance of the device studied. Numerically simulated results indicate that small variations in some design parameters can cause a significant variation in the output electrical power, what strongly suggests that uncertainties must be accounted for in the design of beam energy harvesting systems.
NASA Technical Reports Server (NTRS)
Brendley, K.; Chato, J. C.
1982-01-01
The parameters of the efflux from a helium dewar in space were numerically calculated. The flow was modeled as a one dimensional compressible ideal gas with variable properties. The primary boundary conditions are flow with friction and flow with heat transfer and friction. Two PASCAL programs were developed to calculate the efflux parameters: EFFLUZD and EFFLUXM. EFFLUXD calculates the minimum mass flow for the given shield temperatures and shield heat inputs. It then calculates the pipe lengths, diameter, and fluid parameters which satisfy all boundary conditions. Since the diameter returned by EFFLUXD is only rarely of nominal size, EFFLUXM calculates the mass flow and shield heat exchange for given pipe lengths, diameter, and shield temperatures.
Calculs ab initio de structures electroniques pour un meilleur design de polymeres photovoltaiques
NASA Astrophysics Data System (ADS)
Berube, Nicolas
This thesis focuses on the role of density functional theory in the design of polymers for photovoltaic applications. Theoretical calculations are first studied in the characterization of polymers in the context of collaborations between theory and experiment. The stability and the energy levels of some organic molecules are studied before and after a sulfurization of their carbonyl groups, a process destined to lower the band gaps. The dynamics of the electronic processes and the Raman vibration spectra are also explored in a polycarbazole-based polymer. From then, the usefulness of theoretical calculations in the design of polymers before their syntheses is explored. Density functional theory calculations are studied under the Scharber model in order to predict the efficiency of organic solar cells. Then, a new approach for the design of low band gap polymer based on the aromatic or quinoid structures is established, whose efficiency surpasses the actual donor-acceptor approach. These studies are used in the exploration of the chemical space and several candidate for polymers with interesting electronic properties are presented.
NASA Astrophysics Data System (ADS)
Bertoldi, Dalía S.; Ramos, Susana B.; Guillermet, Armando Fernández
2017-08-01
We present a theoretical analysis of the equation of state (EOS) of metals using a quasi-harmonic Einstein model with a dimensionless cohesive energy versus distance function (F(z)) involving the Wigner-Seitz radius and a material-dependent scaling length, as suggested in classical works by Rose, Ferrante, Smith and collaborators. Using this model, and ;universal; values for the function and its first and second derivatives at the equilibrium distance (z=0), three general interrelations between EOS parameters and the cohesive energy are obtained. The first correlation involves the bulk modulus, and the second, the thermal expansion coefficient. In order to test these results an extensive database is developed, which involves available experimental data, and results of current ab initio density-functional-theory calculations using the VASP code. In particular, the 0 K values for volume, bulk modulus, its pressure derivative, and the cohesive energy of 27 elements belonging to the first (Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn), second (Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd) and third (Hf, Ta, W, Re, Os, Ir, Pt, Au) transition row of the Periodic Table are calculated ab initio and used to test the present results. The third correlation obtained, allows an evaluation of the third derivative of F(z) at z=0 for the current elements. With this new information, a discussion is presented of the possibility of finding a ;universal; F(z) versus z function able to account accurately for the pressure derivative of the bulk modulus of the transition elements.
NASA Astrophysics Data System (ADS)
Neeman, Elias M.; Dréan, Pascal; Huet, T. R.
2016-06-01
The emission of volatile organic compounds, from plants has strong revelance for plant physiology, plant ecology and atmospheric chemistry. Camphene (C10H16) is a bicyclic monoterpene which is emitted in the atmosphere by biogenic sources. The structure of the unique stable conformer was optimized using density functional theory and ab initio calculations. The rotational spectrum of camphene was recorded in a supersonic jet expansion with a Fourier transform microwave spectrometer over the range 2-20 GHz. Signals from the parent species and from the ten 13C isotopomers were observed in natural abundance. The rotational and centrifugal distortion parameters were fitted to a Watson's Hamiltonian in the A-reduction. A magnetic hyperfine structure associated with the pairs of hydrogen nuclei in the methylene groups was observed and modeled.The rotational constants coupled to the equilibrium structure calculations were used to determine the r_0 and the r_m(1) gas-phase geometries of the carbon skeleton. The present work provides the first spectroscopic characterization of camphene in the gas phase and these results are also relevant for ozonolysis kinetics study through Criegee intermediates. R. Baraldi, F. Rapparini, O. Facini, D. Spano and P. Duce, Journal of Mediterranean Ecology, Vol.6, No.1, (2005). A. Bracho-Nunez, N. M. Knothe, S. Welter, M. Staudt, W. R. Costa, M. A. R. Liberato, M. T. F. Piedade, and J. Kesselmeier Biogeosciences, 10, 5855-5873, (2013). Minna Kivimäenpää, Narantsetseg Magsarjav, Rajendra Ghimire, Juha-Matti Markkanen, Juha Heijari, Martti Vuorinen and Jarmo K. Holopainen, Atmospheric Environment, 60, 477-485, (2012). R.C. de M. Oliveira and G. F. Bauerfeldt, J. Phys. Chem. A, 119 2802-2812 (2015)
Hsieh, Po-Fan; Wang, Yu-De; Huang, Chi-Ping; Wu, Hsi-Chin; Yang, Che-Rei; Chen, Guang-Heng; Chang, Chao-Hsiang
2016-07-01
We proposed a mathematical formula to calculate contact surface area between a tumor and renal parenchyma. We examined the applicability of using contact surface area to predict renal function after partial nephrectomy. We performed this retrospective study in patients who underwent partial nephrectomy between January 2012 and December 2014. Based on abdominopelvic computerized tomography or magnetic resonance imaging, we calculated the contact surface area using the formula (2*π*radius*depth) developed by integral calculus. We then evaluated the correlation between contact surface area and perioperative parameters, and compared contact surface area and R.E.N.A.L. (Radius/Exophytic/endophytic/Nearness to collecting system/Anterior/Location) score in predicting a reduction in renal function. Overall 35, 26 and 45 patients underwent partial nephrectomy with open, laparoscopic and robotic approaches, respectively. Mean ± SD contact surface area was 30.7±26.1 cm(2) and median (IQR) R.E.N.A.L. score was 7 (2.25). Spearman correlation analysis showed that contact surface area was significantly associated with estimated blood loss (p=0.04), operative time (p=0.04) and percent change in estimated glomerular filtration rate (p <0.001). On multivariate analysis contact surface area and R.E.N.A.L. score independently affected percent change in estimated glomerular filtration rate (p <0.001 and p=0.03, respectively). On ROC curve analysis contact surface area was a better independent predictor of a greater than 10% change in estimated glomerular filtration rate compared to R.E.N.A.L. score (AUC 0.86 vs 0.69). Using this simple mathematical method, contact surface area was associated with surgical outcomes. Compared to R.E.N.A.L. score, contact surface area was a better predictor of functional change after partial nephrectomy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Algorithms of D-optimal designs for Morgan Mercer Flodin (MMF) models with three parameters
NASA Astrophysics Data System (ADS)
Widiharih, Tatik; Haryatmi, Sri; Gunardi, Wilandari, Yuciana
2016-02-01
Morgan Mercer Flodin (MMF) model is used in many areas including biological growth studies, animal and husbandry, chemistry, finance, pharmacokinetics and pharmacodynamics. Locally D-optimal designs for Morgan Mercer Flodin (MMF) models with three parameters are investigated. We used the Generalized Equivalence Theorem of Kiefer and Wolvowitz to determine D-optimality criteria. Number of roots for standardized variance are determined using Tchebysheff system concept and it is used to decide that the design is minimally supported design. In these models, designs are minimally supported designs with uniform weight on its support, and the upper bound of the design region is a support point.
Design of High Manganese Steels: Calculation of SFE and Ms Temperature
NASA Astrophysics Data System (ADS)
Kumar, Dinesh
High Mn steels have great plasticity when deformed due to twinning, known as TWIP effect (Twinning Induced Plasticity) or due to martensitic transformation, called as TRIP effect (Transformation Induced Plasticity). The stacking fault energy (SFE) controls the deformation mechanism. So calculation of SFE value and Ms temperature is essential for designing of high manganese steels. For twinning to occur, it is usually necessary for the steel stacking fault energy (SFE) to be in the range of 18-35 mJ/m2. If the SFE is <18 mJ/m2, twinning is replaced by martensitic transformation. However, if it is >35 mJ/m2, then the slipping processing will be the only mechanism that contributes to the plastic deformation of steel. For alloys with Mn content between 15% and 25% the SFE is intermediate and then TRIP and TWIP effects coexist. In this work stacking fault energy of some compositions of High manganese steel has been calculated through thermodynamic model and X-ray line profile analysis and these values are verified with the SFE values available in literature. It was found that value of stacking fault energy calculated through thermodynamic model is found to be close with the value calculated through TEM node method and have large difference in values with comparison to X — ray diffraction method. Different empirical equations are used to calculate the Stacking fault energy of high manganese compositions and Martensite start temperature (Ms). Empirical equations are found to be more suitable for SFE calculation for austenitic stainless steels. Ms Temperature calculation from empirical equations is found to be more suitable for austenitic and high manganese steels.
NASA Astrophysics Data System (ADS)
Liu, Gang; Mei, Yang; Zhang, Xin-Xin; Zheng, Wen-Chen
2015-05-01
The high-order perturbation formulas based on a two-mechanism model (where in addition to the contributions from the crystal-field (CF) mechanism in the usually-applied CF theory, those from the generally-neglected charge-transfer (CT) mechanism are also contained) are employed to calculate the spin-Hamiltonian parameters (g factors g//, g⊥ and the hyperfine structure constants A//, A⊥) of the square planar CuCl4 2 - clusters in Cs2ZrCl6 crystal. The needed CF energy levels in the calculations are obtained from the observed optical spectra. The calculated results show reasonable agreement with the experimented values. The negative sign of A// and positive sign of A⊥ are proposed from the calculations. The calculations also suggest that one should take account of the contributions due to both the CF and CT mechanisms for the exact and rational calculations of spin-Hamiltonian parameters of Cu2+-Cl- combination in crystals.
Bergman, W.; First, M.W.; Anderson, W.L.
1995-02-01
We have reviewed the literature on the performance of HEPA filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509[1]. Other HEPA filter designs such as the mini-pleat and separatorless filters are not included in this study. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be damaged and have a residual efficiency of 0%. There are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen. The estimation of the efficiency of the HEPA filters under DBA conditions involves three steps: (1) The filter pressure drop and environmental parameters are determined during and after the DBA, (2) Comparing the filter pressure drop to a set of threshold values above which the filter is damaged. There is a different threshold value for each combination of environmental parameters, and (3) Determining the filter efficiency. If the filter pressure drop is greater than the threshold value, the filter is damaged and is assigned 0% efficiency. If the pressure drop is less, then the filter is not damaged and the efficiency is determined from literature values of the efficiency at the environmental conditions.
Sample size calculations for the design of cluster randomized trials: A summary of methodology.
Gao, Fei; Earnest, Arul; Matchar, David B; Campbell, Michael J; Machin, David
2015-05-01
Cluster randomized trial designs are growing in popularity in, for example, cardiovascular medicine research and other clinical areas and parallel statistical developments concerned with the design and analysis of these trials have been stimulated. Nevertheless, reviews suggest that design issues associated with cluster randomized trials are often poorly appreciated and there remain inadequacies in, for example, describing how the trial size is determined and the associated results are presented. In this paper, our aim is to provide pragmatic guidance for researchers on the methods of calculating sample sizes. We focus attention on designs with the primary purpose of comparing two interventions with respect to continuous, binary, ordered categorical, incidence rate and time-to-event outcome variables. Issues of aggregate and non-aggregate cluster trials, adjustment for variation in cluster size and the effect size are detailed. The problem of establishing the anticipated magnitude of between- and within-cluster variation to enable planning values of the intra-cluster correlation coefficient and the coefficient of variation are also described. Illustrative examples of calculations of trial sizes for each endpoint type are included.
NASA Astrophysics Data System (ADS)
McLellan, Brenda; Nowakowski, Mark; Bokor, Jeffrey; Liang, Cheng-Yen; Hockel, Joshua; Wetzlar, Kyle; Keller, Scott; Sohn, Hyunmin; Carman, Gregory; Young, Anthony; Doran, Andrew; Marcus, Matthew; Klaui, Mathias; Candler, Robert
2015-03-01
We demonstrate the capture and electrically-driven piecewise transport of superparamagnetic microbeads trapped in a magnetostatic potential energy well produced by the magnetic domain walls of Ni microrings on a [Pb(Mg1/3Nb2/3) O3]0.66-[PbTiO3]0.34 (PMN-PT) substrate. Here I present micromagnetic simulations that illustrate the formation of field-initialized domain walls in Ni microrings and calculate the approximate force of attraction experienced by superparamagnetic microbeads near the domain walls. This force is estimated as a function of the ring geometry, bead diameter, and distance from the domain wall, and provides an upper bound for the strain-mediated, electrically-induced domain wall velocity that can be implemented to smoothly transport coupled microbeads within a fluidic environment. These results provide an initial estimate for important technological parameters and set a foundation for the optimization of this microfluidic magnetic control scheme. Supported by E3S and TANMS.
NASA Astrophysics Data System (ADS)
Zeiler, M.; Detraz, S.; Olantera, L.; Pezzullo, G.; Seif El Nasr-Storey, S.; Sigaud, C.; Soos, C.; Troska, J.; Vasey, F.
2016-01-01
Particle detectors for future experiments at the HL-LHC will require new optical data transmitters that can provide high data rates and be resistant against high levels of radiation. Furthermore, new design paths for future optical readout systems for HL-LHC could be opened if there was a possibility to integrate the optical components with their driving electronics and possibly also the silicon particle sensors themselves. All these functionalities could potentially be combined in the silicon photonics technology which currently receives a lot of attention for conventional optical link systems. Silicon photonic test chips were designed in order to assess the suitability of this technology for deployment in high-energy physics experiments. The chips contain custom-designed Mach-Zehnder modulators, pre-designed ``building-block'' modulators, photodiodes and various other passive test structures. The simulation and design flow of the custom designed Mach-Zehnder modulators and some first measurement results of the chips are presented.
Xue, Dingyü; Li, Tingxue
2017-04-27
The parameter optimization method for multivariable systems is extended to the controller design problems for multiple input multiple output (MIMO) square fractional-order plants. The algorithm can be applied to search for the optimal parameters of integer-order controllers for fractional-order plants with or without time delays. Two examples are given to present the controller design procedures for MIMO fractional-order systems. Simulation studies show that the integer-order controllers designed are robust to plant gain variations. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Design parameters for toroidal and bobbin magnetics. [conversion from English to metric units
NASA Technical Reports Server (NTRS)
Mclyman, W. T.
1974-01-01
The adoption by NASA of the metric system for dimensioning to replace long-used English units imposes a requirement on the U.S. transformer designer to convert from the familiar units to the less familiar metric equivalents. Material is presented to assist in that transition in the field of transformer design and fabrication. The conversion data makes it possible for the designer to obtain a fast and close approximation of significant parameters such as size, weight, and temperature rise. Nomographs are included to provide a close approximation for breadboarding purposes. For greater convenience, derivations of some of the parameters are also presented.
Design parameters and source terms: Volume 2, Source terms: Revision 0
Not Available
1987-10-01
The Design Parameters and Source Terms Document was prepared in accordance with DOE request and to provide data for the environmental impact study to be performed in the future for the Deaf Smith County, Texas site for a nuclear waste repository in salt. This document updates a previous unpublished report by Stearns Catalytic Corporation (SCC), entitled ''Design Parameters and Source Terms for a Two-Phase Repository Salt,'' 1985, to the level of the Site Characterization Plan - Conceptual Design Report. The previous unpublished SCC Study identifies the data needs for the Environmental Assessment effort for seven possible Salt Repository sites. 2 tabs.
Munir, A.; Hensel, O.; Scheffler, W.
2010-08-15
Scheffler fixed focus concentrators are successfully used for medium temperature applications in different parts of the world. These concentrators are taken as lateral sections of paraboloids and provide fixed focus away from the path of incident beam radiations throughout the year. The paper presents a complete description about the design principle and construction details of an 8 m{sup 2} surface area Scheffler concentrator. The first part of the paper presents the mathematical calculations to design the reflector parabola curve and reflector elliptical frame with respect to equinox (solar declination = 0) by selecting a specific lateral part of a paraboloid. Crossbar equations and their ellipses, arc lengths and their radii are also calculated to form the required lateral section of the paraboloid. Thereafter, the seasonal parabola equations are calculated for two extreme positions of summer and winter in the northern hemisphere (standing reflectors). The slopes of the parabola equations for equinox (solar declination = 0), summer (solar declination = +23.5) and winter (solar declination = -23.5) for the Scheffler reflector (8 m{sup 2} surface area) are calculated to be 0.17, 0.28, and 0.13 respectively. The y-intercepts of the parabola equations for equinox, summer and winter are calculated as 0, 0.54, and -0.53 respectively. By comparing with the equinox parabola curve, the summer parabola is found to be smaller in size and uses the top part of the parabola curve while the winter parabola is bigger in size and uses the lower part of the parabola curve to give the fixed focus. For this purpose, the reflector assembly is composed of flexible crossbars and a frame to induce the required change of the parabola curves with the changing solar declination. The paper also presents the calculation procedure of seasonal parabola equations for standing reflectors in the southern hemisphere as well as for laying reflectors in the northern and southern hemispheres. Highly
Parallel Calculation of Sensitivity Derivatives for Aircraft Design using Automatic Differentiation
NASA Technical Reports Server (NTRS)
Bischof, c. H.; Green, L. L.; Haigler, K. J.; Knauff, T. L., Jr.
1994-01-01
Sensitivity derivative (SD) calculation via automatic differentiation (AD) typical of that required for the aerodynamic design of a transport-type aircraft is considered. Two ways of computing SD via code generated by the ADIFOR automatic differentiation tool are compared for efficiency and applicability to problems involving large numbers of design variables. A vector implementation on a Cray Y-MP computer is compared with a coarse-grained parallel implementation on an IBM SP1 computer, employing a Fortran M wrapper. The SD are computed for a swept transport wing in turbulent, transonic flow; the number of geometric design variables varies from 1 to 60 with coupling between a wing grid generation program and a state-of-the-art, 3-D computational fluid dynamics program, both augmented for derivative computation via AD. For a small number of design variables, the Cray Y-MP implementation is much faster. As the number of design variables grows, however, the IBM SP1 becomes an attractive alternative in terms of compute speed, job turnaround time, and total memory available for solutions with large numbers of design variables. The coarse-grained parallel implementation also can be moved easily to a network of workstations.
NASA Technical Reports Server (NTRS)
Weiser, P.; Nordmann, R.
1991-01-01
In today's rotordynamic calculations, the input parameters for a finite element analysis (FEA) determine very much the reliability of eigenvalue and eigenmode predictions. While modeling of an elastic structure by means of beam elements etc. is relatively straightforward to perform and the input data for journal bearings are usually known exactly enough, the determination of stiffness and damping for labyrinth seals is still the subject of many investigations. Therefore, the rotordynamic influence of labyrinths is often not included in FEA for rotating machinery because of a lack of computer programs to calculate these parameters. This circumstance can give rise to severe vibration problems especially for high performance turbines or compressors, resulting in remarkable economic losses. The forces generated in labyrinths can be described for small motions around the seal center with a linearized force-motion relationship. Several years ago, we started with the development of computer codes for the determination of rotordynamic seal coefficients. Our different approaches to evaluate the dynamic fluid forces generated by turbulent, compressible seal flow are introduced.
The simulative calculation and optimum design for FOA, the purge gas sweeping system
NASA Astrophysics Data System (ADS)
Wang, Liquan; Jing, Yukun; Feng, Bing; Li, Fuquan; Xiang, Yong; Han, Wei; Wang, Fang
2016-01-01
This paper first studies the structure effect law in order to design a reasonable option in theory for the Final Optics Assembly(FOA)' harmonic converter module, involved in the design of the fluid theory, including the basic equations of fluid motion, the form of fluid motion and fluid movement in the small hole. Optimizing the structure need to be applied to the simulation software, which requires the Fluent simulation principle. Then, combined with theoretical knowledge to design the overall structure of the multiplier module, It will apply the simulation software to optimize structural parameters of the board and use control system to realize it for verifying the law obtained by simulation under various conditions whether consistent with the law in actual work of the sweeping system.
NASA Astrophysics Data System (ADS)
Zeng, Xiaozheng; Wu, Liyong; McGough, Robert J.
2005-04-01
Large spherical ultrasound phased arrays are ideal for simulation studies of thermal therapy devices designed for noninvasive breast cancer treatments. In a spherical array, circular sources packed in a dense hexagonal arrangement facilitate the most efficient use of the available aperture. Circular sources are also preferred for simulations of large phased arrays because pressure fields are computed more rapidly for circular pistons than for any other transducer geometry. The computation time is further reduced for circular transducers with grid sectoring. With this approach, the grid of computed pressures is divided into several regions, and then grid sectoring applies more abscissas in regions where the pressure integral converges slowly and fewer abscissas where the integral converges rapidly. As a result, the peak value of the numerical error is roughly the same in each sector, so the maximum numerical error in the computed field is maintained while the computation time is significantly reduced. The grid sectoring approach is extended to three dimensions (3D) for pressure field calculations with spherical arrays. In 3D calculations, the sectors are represented by cones, and the intersections between the computational grid and these cones define the boundaries required for grid sectoring. When these cone structures are applied to spherical phased arrays, 3D grid sectoring calculations rapidly compute the pressure fields so that the time required for array design and evaluation is substantially reduced.
Multiobjective optimization in structural design with uncertain parameters and stochastic processes
NASA Technical Reports Server (NTRS)
Rao, S. S.
1984-01-01
The application of multiobjective optimization techniques to structural design problems involving uncertain parameters and random processes is studied. The design of a cantilever beam with a tip mass subjected to a stochastic base excitation is considered for illustration. Several of the problem parameters are assumed to be random variables and the structural mass, fatigue damage, and negative of natural frequency of vibration are considered for minimization. The solution of this three-criteria design problem is found by using global criterion, utility function, game theory, goal programming, goal attainment, bounded objective function, and lexicographic methods. It is observed that the game theory approach is superior in finding a better optimum solution, assuming the proper balance of the various objective functions. The procedures used in the present investigation are expected to be useful in the design of general dynamic systems involving uncertain parameters, stochastic process, and multiple objectives.
Development of a parameter optimization technique for the design of automatic control systems
NASA Technical Reports Server (NTRS)
Whitaker, P. H.
1977-01-01
Parameter optimization techniques for the design of linear automatic control systems that are applicable to both continuous and digital systems are described. The model performance index is used as the optimization criterion because of the physical insight that can be attached to it. The design emphasis is to start with the simplest system configuration that experience indicates would be practical. Design parameters are specified, and a digital computer program is used to select that set of parameter values which minimizes the performance index. The resulting design is examined, and complexity, through the use of more complex information processing or more feedback paths, is added only if performance fails to meet operational specifications. System performance specifications are assumed to be such that the desired step function time response of the system can be inferred.
NASA Astrophysics Data System (ADS)
Baelmans, M.; Blommaert, M.; Dekeyser, W.; Van Oevelen, T.
2017-03-01
Plasma edge transport codes play a key role in the design of future divertor concepts. Their long simulation times in combination with a large number of control parameters turn the design into a challenging task. In aerodynamics and structural mechanics, adjoint-based optimization techniques have proven successful to tackle similar design challenges. This paper provides an overview of achievements and remaining challenges with these techniques for complex divertor design. It is shown how these developments pave the way for fast sensitivity analysis and improved design from different perspectives.
Correlation of mid-infrared quantum-cascade laser performance with laser design parameters
NASA Astrophysics Data System (ADS)
Leavitt, R. P.; Bradshaw, J. L.; Lascola, K. M.; Towner, F. J.; Pham, J. T.; Bruno, J. D.; Gmachl, C. F.; Liu, P. Q.
2012-06-01
Several different quantum-cascade (QC) laser designs spanning the wavelength range between ~3.8 and ~4.8 microns were grown, and devices were fabricated and tested. The active regions of these designs consist of strained layers of (In,Ga)As and (In,Al)As. For several of these designs, we varied design parameters including injector doping, sectioncoupling strength, and the number of QC laser periods. Lasers were tested near room temperature under both quasi-cw and low-duty-cycle conditions. Device performance is compared with theoretical expectations, and conclusions are reached on the relative merit of various design modifications.
A design of a DICOM-RT-based tool box for nonrigid 4D dose calculation.
Wong, Victy Y W; Baker, Colin R; Leung, T W; Tung, Stewart Y
2016-03-08
The study was aimed to introduce a design of a DICOM-RT-based tool box to facilitate 4D dose calculation based on deformable voxel-dose registration. The computational structure and the calculation algorithm of the tool box were explicitly discussed in the study. The tool box was written in MATLAB in conjunction with CERR. It consists of five main functions which allow a) importation of DICOM-RT-based 3D dose plan, b) deformable image registration, c) tracking voxel doses along breathing cycle, d) presentation of temporal dose distribution at different time phase, and e) derivation of 4D dose. The efficacy of using the tool box for clinical application had been verified with nine clinical cases on retrospective-study basis. The logistic and the robustness of the tool box were tested with 27 applications and the results were shown successful with no computational errors encountered. In the study, the accumulated dose coverage as a function of planning CT taken at end-inhale, end-exhale, and mean tumor position were assessed. The results indicated that the majority of the cases (67%) achieved maximum target coverage, while the planning CT was taken at the temporal mean tumor position and 56% at the end-exhale position. The comparable results to the literature imply that the studied tool box can be reliable for 4D dose calculation. The authors suggest that, with proper application, 4D dose calculation using deformable registration can provide better dose evaluation for treatment with moving target.
Hatch, K F; Coles, E; Busey, H; Goldman, S C
1976-08-01
We describe an improved method of logit-log curve fitting, by adjusting end-point parameters in radioimmunoassay studies, for use with a small desk-top programmable calculator. Straight logit-log analyses are often deficient because of their high sensitivity to small errors in the end-point parametes B0 and NSB (the actual measured activity in the tubes). The literature suggests techniques for adjusting these end-point parameters, but they require too much computing time and programming space to be used with a desk-top programmable calculator. The extension to the logit-log model presented here is easily handled by the programmable calculator and provides a good estimate of the change required in B0 and NSB to obtain a better fit. The program requires 1.5 min to run on our desk-top programmable calculator, and has resulted in improved data analysis for all of the 11 types of radioimmunoassay studied.
Stiffness Parameter Design of Suspension Element of Under-Chassis-Equipment for A Rail Vehicle
NASA Astrophysics Data System (ADS)
Ma, Menglin; Wang, Chengqiang; Deng, Hai
2017-06-01
According to the frequency configuration requirements of the vibration of railway under-chassis-equipment, the three- dimension stiffness of the suspension elements of under-chassis-equipment is designed based on the static principle and dynamics principle. The design results of the concrete engineering case show that, compared with the design method based on the static principle, the three- dimension stiffness of the suspension elements designed by the dynamic principle design method is more uniform. The frequency and decoupling degree analysis show that the calculation frequency of under-chassis-equipment under the two design methods is basically the same as the predetermined frequency. Compared with the design method based on the static principle, the design method based on the dynamic principle is adopted. The decoupling degree can be kept high, and the coupling vibration of the corresponding vibration mode can be reduced effectively, which can effectively reduce the fatigue damage of the key parts of the hanging element.
New analytical input impedance calculation for fast design of printed narrow slot antenna
NASA Astrophysics Data System (ADS)
Akan, Volkan; Yazgan, Erdem
2011-09-01
In this article, fast and simple closed-form relations are presented to calculate input impedance of filamentary-excited printed narrow slot antenna on electrically thin dielectric substrate near to half wavelength resonance frequency. This antenna is a complementary structure of thin printed dipole antenna. The obtained formulations have been verified numerically by a commercially available full-wave electromagnetic simulator and then a prototype antenna has been produced. Experimental measurements are realised on the antenna and these measurement values of input impedance also have verified analytical relations and numerical simulations. It is shown that analytical, numerical and experimental results are close to each other. Therefore, these relations can be utilised as an initial design step just before making detailed numerical analyses. Besides, the given relations can be easily realised in CAD-oriented platforms for fast calculations.
Villarreal Camacho, José Luis; Mendoza Torres, Evelyn; Cadena, Christian; Prieto, Julieth; Varela Prieto, Lourdes Luz; Villanueva Torregroza, Daniel Antonio
2013-05-01
The quality of multiplex polymerase chain reaction (PCR) assays depends on several factors. Therefore, it is important to establish the optimal conditions to achieve efficient amplification. The objective of this study was to implement a 5 × 4 factorial design combined with image analysis using agarose gels and an efficiency calculation to optimize a multiplex PCR assays for the detection of Salmonella enterica serovar typhimurium. We used 12 ng of Salmonella DNA obtained from pure cultures and applied different annealing temperatures (65°C, 64.5°C, 63.3°C, 61.4°C, or 59°C) and different MgCl2 concentrations (1 mM, 1.5 mM, 2 mM, or 2.5 mM) to amplify regions of the fliC, rfbJ, and fljB genes. The 5 × 4 factorial design was performed using Statgraphics Plus software version 5.1, and the images were analyzed using Image Lab(TM) software. Superior amplification was obtained using an annealing temperature of 65°C and 2 mM MgCl2 . This finding was confirmed by calculating the efficiency of multiplex PCR assays (6.1%) at these conditions. We propose the application of factorial design and image analysis to determine the most suitable conditions for multiplex PCR optimization. © 2013 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Radaev, A. I.; Schurovskaya, M. V.
2015-12-01
The choice of the spatial nodalization for the calculation of the power density and burnup distribution in a research reactor core with fuel assemblies of the IRT-3M and VVR-KN type using the program based on the Monte Carlo code is described. The influence of the spatial nodalization on the results of calculating basic neutronic characteristics and calculation time is investigated.
Radaev, A. I. Schurovskaya, M. V.
2015-12-15
The choice of the spatial nodalization for the calculation of the power density and burnup distribution in a research reactor core with fuel assemblies of the IRT-3M and VVR-KN type using the program based on the Monte Carlo code is described. The influence of the spatial nodalization on the results of calculating basic neutronic characteristics and calculation time is investigated.
Calibration of Discrete Element Heat Transfer Parameters by Central Composite Design
NASA Astrophysics Data System (ADS)
Deng, Zongquan; Cui, Jinsheng; Hou, Xuyan; Jiang, Shengyuan
2017-03-01
The efficiency and precision of parameter calibration in discrete element method (DEM) are not satisfactory, and parameter calibration for granular heat transfer is rarely involved. Accordingly, parameter calibration for granular heat transfer with the DEM is studied. The heat transfer in granular assemblies is simulated with DEM, and the effective thermal conductivity (ETC) of these granular assemblies is measured with the transient method in simulations. The measurement testbed is designed to test the ETC of the granular assemblies under normal pressure and a vacuum based on the steady method. Central composite design (CCD) is used to simulate the impact of the DEM parameters on the ETC of granular assemblies, and the heat transfer parameters are calibrated and compared with experimental data. The results show that, within the scope of the considered parameters, the ETC of the granular assemblies increases with an increasing particle thermal conductivity and decreases with an increasing particle shear modulus and particle diameter. The particle thermal conductivity has the greatest impact on the ETC of granular assemblies followed by the particle shear modulus and then the particle diameter. The calibration results show good agreement with the experimental results. The error is less than 4%, which is within a reasonable range for the scope of the CCD parameters. The proposed research provides high efficiency and high accuracy parameter calibration for granular heat transfer in DEM.
A simple method of calculating Stirling engines for engine design optimization
NASA Technical Reports Server (NTRS)
Martini, W. R.
1978-01-01
A calculation method is presented for a rhombic drive Stirling engine with a tubular heater and cooler and a screen type regenerator. Generally the equations presented describe power generation and consumption and heat losses. It is the simplest type of analysis that takes into account the conflicting requirements inherent in Stirling engine design. The method itemizes the power and heat losses for intelligent engine optimization. The results of engine analysis of the GPU-3 Stirling engine are compared with more complicated engine analysis and with engine measurements.
A simple method of calculating Stirling engines for engine design optimization
NASA Technical Reports Server (NTRS)
Martini, W. R.
1978-01-01
A calculation method is presented for a rhombic drive Stirling engine with a tubular heater and cooler and a screen type regenerator. Generally the equations presented describe power generation and consumption and heat losses. It is the simplest type of analysis that takes into account the conflicting requirements inherent in Stirling engine design. The method itemizes the power and heat losses for intelligent engine optimization. The results of engine analysis of the GPU-3 Stirling engine are compared with more complicated engine analysis and with engine measurements.
Final Report for "Design calculations for high-space-charge beam-to-RF conversion".
David N Smithe
2008-10-17
Accelerator facility upgrades, new accelerator applications, and future design efforts are leading to novel klystron and IOT device concepts, including multiple beam, high-order mode operation, and new geometry configurations of old concepts. At the same time, a new simulation capability, based upon finite-difference “cut-cell” boundaries, has emerged and is transforming the existing modeling and design capability with unparalleled realism, greater flexibility, and improved accuracy. This same new technology can also be brought to bear on a difficult-to-study aspect of the energy recovery linac (ERL), namely the accurate modeling of the exit beam, and design of the beam dump for optimum energy efficiency. We have developed new capability for design calculations and modeling of a broad class of devices which convert bunched beam kinetic energy to RF energy, including RF sources, as for example, klystrons, gyro-klystrons, IOT's, TWT’s, and other devices in which space-charge effects are important. Recent advances in geometry representation now permits very accurate representation of the curved metallic surfaces common to RF sources, resulting in unprecedented simulation accuracy. In the Phase I work, we evaluated and demonstrated the capabilities of the new geometry representation technology as applied to modeling and design of output cavity components of klystron, IOT's, and energy recovery srf cavities. We identified and prioritized which aspects of the design study process to pursue and improve in Phase II. The development and use of the new accurate geometry modeling technology on RF sources for DOE accelerators will help spark a new generational modeling and design capability, free from many of the constraints and inaccuracy associated with the previous generation of “stair-step” geometry modeling tools. This new capability is ultimately expected to impact all fields with high power RF sources, including DOE fusion research, communications, radar and