5,219 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Diffusion"  
prev Results: 97 - 120 next
open access

Improved Spatial Resolution in Thick, Fully-Depleted CCDs withEnhanced Red Sensitivity

Description: The point spread function (PSF) is an important measure of spatial resolution in CCDs for point-like objects, since it affects image quality and spectroscopic resolution. We present new data and theoretical developments for lateral charge diffusion in thick, fully-depleted charge-coupled devices (CCDs) developed at Lawrence Berkeley National Laboratory (LBNL). Because they can be over-depleted, the LBNL devices have no field-free region and diffusion is controlled through the application of an … more
Date: March 9, 2006
Creator: Fairfield, Jessamyn A.; Groom, Donald E.; Bailey, Stephen J.; Bebek, Christopher J.; Holland, Stephen E.; Karcher, Armin et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Analysis and Numerical Solution for Multi-Physics Coupling of Neutron Diffusion and Thermomechanics in Spherical Fast Burst Reactors

Description: Coupling neutronics to thermomechanics is important for the analysis of fast burst reactors, because the criticality and safety study of fast burst reactors heavily depends on the thermomechanical behavior of fuel materials. For instance, the shut down mechanism or the transition between super and sub-critical states are driven by the fuel material expansion or contraction. The material expansion or contraction is due to temperature gradient which results from fission power. In this paper, we i… more
Date: May 1, 2009
Creator: Kadioglu, Samet Y.; Knoll, Dana A. & Oliveira, Cassiano de
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Environmental aspects of cooling tower operation: survey of the emission, transport, and deposition of drift from the K-31 and K-33 cooling towers at ORGDP

Description: The results from a program ulo evaluaule the environmental aspeculs of cooling ulower operation at the Oak Ridge Gaseous Diffusion Plan (ORGDP) are presented. The quantities of chemicals being introduced into the atmosphere as well as the deposition of these chemicals on the environs surrounding the cooling towers were measured. Based on the tests performed, the cooling towers, under present operating conditions, are noul causing any adverse effect on the native vegetation surrounding ORGDP. (a… more
Date: February 1, 1974
Creator: Jallouk, P.A.; Kidd, G.J. Jr. & Shapiro, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Diffusional exchange of isotopes in a metal hydride sphere.

Description: This report describes the Spherical Particle Exchange Model (SPEM), which simulates exchange of one hydrogen isotope by another hydrogen isotope in a spherical metal hydride particle. This is one of the fundamental physical processes during isotope exchange in a bed of spherical metal particles and is thus one of the key components in any comprehensive physics-based model of exchange. There are two important physical processes in the model. One is the entropy of mixing between the two isotopes;… more
Date: April 1, 2011
Creator: Wolfer, Wilhelm G.; Hamilton, John C. & James, Scott Carlton
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

THE SELF-DIFFUSION OF NIOBIUM--III. Final Progress Report for July 1, 1958 to January 1, 1959

Description: The self-diffusion coefficient of niobium was measured over the temperature range 1535 to 2120 C, using the radioactive isotope Nb95 as the tracer. The data for the temperature dependence of the self-diffusion coefflcient are best fitted by the equation D = (12.4 cores consistin 0.2) exp STA(-105,000 cores consistin 3OOO)/RT! cm/sup 2//sec. (auth)
Date: March 30, 1959
Creator: Resnick, R.; Castleman, L.S. & Seigle, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Binary Segmentation Approach for Boxing Ribosome Particles in Cryo EM Micrographs

Description: Three-dimensional reconstruction of ribosome particles from electron micrographs requires selection of many single-particle images. Roughly 100,000 particles are required to achieve approximately 10 angstrom resolution. Manual selection of particles, by visual observation of the micrographs on a computer screen, is recognized as a bottleneck in automated single particle reconstruction. This paper describes an efficient approach for automated boxing of ribosome particles in micrographs. Use of a… more
Date: June 24, 2003
Creator: Adiga, Umesh P. S.; Malladi, Ravi; Baxter, William & Glaeser, Robert M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

On Perturbation Components Correspondence between Diffusion and Transport

Description: We have established a correspondence between perturbation components in diffusion and transport theory. In particular we have established the correspondence between the leakage perturbation component of the diffusion theory to that of the group self scattering in transport theory. This has been confirmed by practical applications on sodium void reactivity calculations of fast reactors. Why this is important for current investigations? Recently, there has been a renewed interest in designing fas… more
Date: November 1, 2012
Creator: Palmiotti, G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Atomistic Studies of Cation Transport in Tetragonal ZrO2 During Zirconium Corrosion

Description: Zirconium alloys are the major fuel cladding materials in current reactors. The water-side corrosion is one of the major degradation mechanisms of these alloys. During corrosion the transport of oxidizing species in zirconium dioxide (ZrO2) determines the corrosion kinetics. Previously it has been argued that the outward diffusion of cation ions is important for forming protective oxides. In this work, the migration of Zr defects in tetragonal ZrO2 is studied with temperature accelerated dynami… more
Date: October 1, 2013
Creator: Bai, Xian-Ming; Zhang, Yongfeng & Tonks, Michael R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

TIME-DEPENDENT THERMAL-NEUTRON ENERGY SPECTRA IN A MONOATOMIC HEAVY GAS

Description: The time-dependent thermal neutron energy spectra, for times greater thsn the slowing-down time, were generated in a monoatomic heavy gas using multigroup formalism. These spectra were obtained for infinite as well as finite media of Be and graphite. The behavior of asymptotic energy spectra during the last stage of neutron thermalization and diffusion periods was studied. The thermalization time constant for the establishment of the final Maxwellian velocity distribution of neutrons, in a mono… more
Date: July 11, 1960
Creator: Purohit, S N
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Some influences of regional boundary layer flow on atmospheric transport and dispersion

Description: From American Chemical Society 2nd joint conference on sensing of environmental pollutants; Washington, District of Columbia, USA (10 Dec 1973). The scales on which most atmospheric transport and diffusion work has been carried out have been either on the order of less than a few kilometers or over a few hundred kilometers. Only recently has serious attention been turned to the intermediate scale on the order of a few tens of kilometers. It is on this regional scale in the boundary layer of the… more
Date: January 1, 1973
Creator: Wendell, L. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Dynamics of Electroencephalogram Entropy and Pitfalls of Scaling Detection

Description: This article discusses dynamics of electroencephalogram entropy and pitfalls of scaling detection. Herein the authors study the time evolution of diffusion entropy to elucidate the scaling of EGG time series.
Date: March 10, 2010
Creator: Ignaccolo, Massimiliano; Latka, Miroslaw; Jernajczyk, Wojciech; Grigolini, Paolo & West, Bruce J.
Item Type: Refine your search to only Article
Partner: UNT College of Arts and Sciences
open access

Investigation of the Mass Transfer Properties of Saline Water Systems

Description: From Introduction: "This investigation was undertaken in order to obtain the appropriate property data for both binary and muticomponent salt solutions and to determine the usefulness of the simple Nernst-type equations, compared with more exact flux-driving force equations, for predicting species transport in molecular diffusion processes of importance in desalination research. The following sections present the details of the approaches taken to each of the tasks and the results derived from … more
Date: September 1966
Creator: Richardson, John L.; Getz, Richard J. & Segovia, Gilbert
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nucleation and Growth of Ice Crystals

Description: From Introduction: "The objective of this investigation was to obtain data which will lead to a better understanding of the mechanism of ice formation in saline water. That is, whether the crystal growth is controlled by heat transfer, nucleation of new layers, or diffusion of matter."
Date: January 1965
Creator: Farrar, John & Hamilton, W. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Diffusion of the Impurity Elements in Technical Iron into Solid Iron

Description: The diffusion of carbon in solid iron has been the subject of numerous investigations over since the middle of the 19th century. Little has been published on the diffusion of the other technically important impurities present in iron. The purpose of this investigation is to help shed light on diffusion phenomena in iron. The work was performed in 1919 at the Metallurgical Institute of the Technische Hochschule in Breslin
Date: unknown
Creator: Fry, Adolf
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Diffusion of Iron, Cobalt, and Nickel in Gold, Report No. 5

Description: "The diffusivities of Fe, Co, and Al in otherwise pure Au were determined by a residual activity technique. It was found that the frequency factors and activation energies of the transition elements into Au are normal relative to the values for Au self-diffusion, and suggest that lattice diffusion is operative, in contrast to the corresponding situation for the diffusion of these elements in Al. This difference in behavior is explained in terms of the marked difference in solid solubilities in … more
Date: June 6, 1962
Creator: Duhl, David N.; Hirano, Ken-ichi & Cohen, Morris
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Colloidal Synthesis of Hollow Cobalt Sulfide Nanocrystals

Description: Formation of cobalt sulfide hollow nanocrystals through amechanism similar to the Kirkendall Effect has been investigated indetail. It was found that performing the reaction at>120oC leads tofast formation of a single void ins ide each shell, whereas at roomtemperature multiple voids are formed within each shell, which can beattributed to strongly temperature-dependent diffusivities for vacancies.The void formation process is dominated by outward diffusion of cobaltcations; still, significant i… more
Date: March 16, 2006
Creator: Yin, Yadong; Erdonmez, Can K.; Cabot, Andreu; Hughes, Steven & Alivisatos, A. Paul
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen