22,343 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Transport"  
Results: 1 - 24 next
open access

Improvements in release probability by using an overpack. [Obsolete munitions]

Description: An analysis was performed to determine the probability of an unconfined release of hazardous material as a consequence of being involved in a severe transportation accident. Two packaging scenarios were considered: (1) material was palletized and placed in a standard aluminum sided trailer, and (2) the same material was placed in an overpackage. In addition to truck, both rail and air transport were also considered. Several release categories were defined ranging from minor to very large, and t… more
Date: January 1, 1986
Creator: Rhyne, W.R.; Ashwood, T.L. & Shappert, L.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Automated Monte Carlo biasing for photon-generated electrons near surfaces.

Description: This report describes efforts to automate the biasing of coupled electron-photon Monte Carlo particle transport calculations. The approach was based on weight-windows biasing. Weight-window settings were determined using adjoint-flux Monte Carlo calculations. A variety of algorithms were investigated for adaptivity of the Monte Carlo tallies. Tree data structures were used to investigate spatial partitioning. Functional-expansion tallies were used to investigate higher-order spatial representat… more
Date: September 1, 2009
Creator: Franke, Brian Claude; Crawford, Martin James & Kensek, Ronald Patrick
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Transport data libraries for incident proton and neutron energies to 100 MeV

Description: A joint effort between the Applied Nuclear Science and Radiation Transport groups at Los Alamos has begun to develop and implement proton, neutron, and photon transport libraries for incident energies up to 100 MeV. The major steps involved in this effort are: (1) development of evaluated (ENDF/B) data formats appropriate for higher energies; (2) extension of low-energy nuclear physics theoretical models for applicability up to 100 MeV; (3) calculation and evaluation of nuclear data in ENDF/B-V… more
Date: January 1, 1989
Creator: Young, P. G.; Arthur, E. D.; Bozoian, M.; England, T. R.; Hale, G. M.; LaBauve, R. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

On Carrier Facilitated Transport Through Membranes

Description: Facilitated transport is a process, whereby the diffusion of a solute across a membrane is chemically enhanced. In this report an analysis is given of a facilitated transport system involving a volatile species A which reacts with a nonvolatile carrier species B to form the nonvolatile product AB.
Date: June 1980
Creator: Kaper, H. G.; Leaf, G. K. & Matkowsky, Bernard J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Low-temperature charge transport in Ga-acceptor nanowires implanted by focused-ion beams

Description: Ga-acceptor nanowires were embedded in crystalline Si using focused-ion beams. The dc current-voltage characteristics of these wires after annealing are highly nonlinear at low temperatures, and a threshold voltage of less than 50 mV is observed independent of Ga+ dosage and implant beam overlap. These features suggest a Coulomb blockade transport mechanism presumably caused by a network of Ga precipitates in the substrate. This granular scenario is further supported by measurements of gated na… more
Date: July 31, 2007
Creator: Schenkel, Thomas; Robinson, S.J.; Perkins, C.L.; Tucker, J.R.; Schenkel, T.; Wang, X.W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Finite element method for solving neutron transport problems

Description: A finite element method is introduced for solving the neutron transport equations. Our method falls into the category of Petrov-Galerkin solution, since the trial space differs from the test space. The close relationship between this method and the discrete ordinate method is discussed, and the methods are compared for simple test problems.
Date: March 21, 1984
Creator: Ferguson, J.M. & Greenbaum, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

DOE transporation programs - computerized techniques

Description: One of the major thrusts of the transportation programs at the Oak Ridge National Laboratory has been the development of a number of computerized transportation programs and data bases. The U.S. Department of Energy (DOE) is supporting these efforts through the Transportation Technology Center at Sandia National Laboratories and the Tranportation Operations and Traffic Management (TOTM) organization at DOE Headquarters. Initially this project was centered upon research activities. However, sinc… more
Date: January 1, 1983
Creator: Joy, D.S.; Johnson, P.E.; Fore, C.S. & Peterson, B.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Energy Deposition by 45-GeV Photons in H, Be, Al, Cu, and Ta

Description: Electron--photon cascade calculations have been carried out for zero- width beams of 45-GeV photons normally incident on semi-infinite slabs of hydrogen, beryllium, aluminum, copper, and tantalum. The energy deposition is given as a function of both depth and radius in the slabs. (auth)
Date: January 1, 1974
Creator: Alsmiller, R. G., Jr. & Barish, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Angular Distribution of Particles Emerging from a Diffusive Region and its Implications for the Fleck-Canfield Random Walk Algorithm for Implicit Monte Carlo Radiation Transport

Description: We present various approximations for the angular distribution of particles emerging from an optically thick, purely isotropically scattering region into a vacuum. Our motivation is to use such a distribution for the Fleck-Canfield random walk method [1] for implicit Monte Carlo (IMC) [2] radiation transport problems. We demonstrate that the cosine distribution recommended in the original random walk paper [1] is a poor approximation to the angular distribution predicted by transport theory. Th… more
Date: July 3, 2000
Creator: Cooper, M. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Baseline requirements of the proposed action for the Transportation Management Division routing models

Description: The potential impacts associated with the transportation of hazardous materials are important to shippers, carriers, and the general public. This is particularly true for shipments of radioactive material. The shippers are primarily concerned with safety, security, efficiency, and equipment requirements. The carriers are concerned with the potential impact that radioactive shipments may have on their operations--particularly if such materials are involved in an accident. The general public has … more
Date: February 1, 1995
Creator: Johnson, P.E. & Joy, D.S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

US Department of Energy Transportation Programs: computerized techniques

Description: The US Department of Energy is currently sponsoring the development of four specialized transportation programs at Oak Ridge National Laboratory. The programs function as research tools that provide unique computerized techniques for planning the safe shipment of radioactive and hazardous materials. Major achievements include the development of rail and highway routing models, an emergency response assistance program, a data base focusing on legislative requirements, and a resource file identif… more
Date: January 1, 1984
Creator: Joy, D.S.; Johnson, P.E.; Fore, C.S. & Peterson, B.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Public information circular for shipments of irradiated reactor fuel. Revision 5

Description: This circular has been prepared in response to numerous requests for information regarding routes used for the shipment of irradiated reactor (spent) fuel subject to regulation by the Nuclear Regulatory Commission (NRC), and to meet the requirements of Public Law 96-295. The NRC staff must approve such routes prior to their first use in accordance with the regulatory provisions of Section 73.37 of 10 CFR Part 73. The information included reflects NRC staff knowledge as of June 1, 1985. Spent fu… more
Date: June 1, 1985
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Escape and transmission probabilities in cylindrical geometry

Description: An improved technique for the generation of escape and transmission probabilities in cylindrical geometry was applied to the existing resonance cross section processing code ROLAIDS. The algorithm of Hwang and Toppel, (ANL-FRA-TM-118) (with modifications) was employed. The probabilities generated were found to be as accurate as those given by the method previously applied in ROLAIDS, while requiring much less computer core storage and CPU time. (RWR)
Date: January 1, 1980
Creator: Bjerke, M.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Transverse centroid oscillations in solenoidially focused beam transport lattices

Description: Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable"alignment functions" and"bending functions" that efficiently describe the characteristics of the centroid oscillations induced by me… more
Date: August 1, 2008
Creator: Lund, Steven M.; Wootton, Christopher J. & Lee, Edward P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Piecewise linear discretization of Symbolic Implicit Monte Carlo radiation transport in the difference formulation

Description: We describe a Monte Carlo solution for time dependent photon transport, in the difference formulation with the material in local thermodynamic equilibrium (LTE), that is piecewise linear in its treatment of the material state variable. Our method employs a Galerkin solution for the material energy equation while using Symbolic Implicit Monte Carlo (SIMC) to solve the transport equation. In constructing the scheme, one has the freedom to choose between expanding the material temperature, or the … more
Date: November 15, 2005
Creator: Brooks III, E D; Szoke, A & Peterson, J L
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport

Description: Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the differen… more
Date: December 13, 2004
Creator: McKinley, M. S.; Brooks, E. D., III & Daffin, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen