Predictions of Radionuclide Migration Rates for a Subseabed Repository

1981 ◽  
Vol 6 ◽  
Author(s):  
L. H. Brush
Keyword(s):  
Heat Transfer ◽  
Deep Sea ◽  
Fission Products ◽  
Radionuclide Migration ◽  
Migration Rates ◽  
Field Verification ◽  
Anionic Species ◽  
And Diffusion ◽  
Temperature Interactions ◽  
The U.S

ABSTRACTGeochemical research carried out by the U.S. Subseabed Disposal Program is described. Data from studies of high temperature interactions between sediments and porewater (seawater), and of sorption and diffusion of radionuclides in oxidized, deep-sea sediments are used, along with results from heat transfer studies, to predict migration rates of radionuclides in a subseabed repository.Preliminary results for most radionuclides in oxidized sediments are very encouraging: fission products with moderate values of KD (generally 10 to 10 ml/g), and actinides with high values of KD (generally 103 to 106 ml/g) would not migrate significant distances before decaying to innocous concentrations. 137Cs, 90Sr, and 239Pu are among this group. The results for anionic species are less encouraging, but preliminary work with reduced sediments indicates that Tc can be effectively isolated.Planning for a field verification of these laboratory and modeling studies is also described.

Diaspora in the United States: Chinese and Indians Compared

2010 ◽  
Vol 6 (2) ◽  
pp. 286-310 ◽  
Author(s):  
Emily Skop ◽  
Wei Li
Keyword(s):  
United States ◽  
Racial Discrimination ◽  
20Th Century ◽  
The United States ◽  
Foreign Born ◽  
Migration Rates ◽  
China And India ◽  
History Of ◽  
Migrant Groups ◽  
The U.S

AbstractIn recent years, the migration rates from both China and India to the U.S. have accelerated. Since 2000 more than a third of foreign-born Chinese and 40% of foreign-born Indians have arrived in that country. This paper will document the evolving patterns of immigration from China and India to the U.S. by tracing the history of immigration and racial discrimination, the dramatic transitions that have occurred since the mid-20th century, and the current demographic and socioeconomic profiles of these two migrant groups.

Heat Transfer and Diffusion

2018 ◽  
pp. 39-48
Author(s):  
Joseph W. Freeman ◽  
Debabrata Banerjee
Keyword(s):  
Heat Transfer ◽  
And Diffusion

scholarly journals Rayleigh wave propagation in transversely isotropic magneto-thermoelastic medium with three-phase-lag heat transfer and diffusion

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Iqbal Kaur ◽  
Parveen Lata
Keyword(s):  
Heat Transfer ◽  
Rayleigh Wave ◽  
Homogeneous Medium ◽  
Transversely Isotropic ◽  
Phase Lag ◽  
Attenuation Coefficients ◽  
Three Phase ◽  
Stress Components ◽  
And Diffusion ◽  
Penetration Depths

Abstract The present research deals with the propagation of Rayleigh wave in transversely isotropic magneto-thermoelastic homogeneous medium in the presence of mass diffusion and three-phase-lag heat transfer. The wave characteristics such as phase velocity, attenuation coefficients, specific loss, and penetration depths are computed numerically and depicted graphically. The normal stress, tangential stress components, temperature change, and mass concentration are computed and drawn graphically. The effects of three-phase-lag heat transfer, GN type-III, and LS theory of heat transfer are depicted on the various quantities. Some particular cases are also deduced from the present investigation.

Computational Investigation of Flow Over Geometry Compliant Lattice Structures

2018 ◽  
Author(s):  
James J. Tinsley ◽  
Gregory J. Vernon ◽  
Kelly O. Homan
Keyword(s):  
Heat Transfer ◽  
Additive Manufacturing ◽  
Integral Geometry ◽  
Single Unit ◽  
Unit Cell ◽  
Lattice Structures ◽  
Computational Investigation ◽  
Enhance Heat Transfer ◽  
Arbitrary Flow ◽  
The U.S

With the increasing prevalence of additive manufacturing, geometries that would not have been possible to manufacture just a few years ago are becoming a reality. One example is the ability to create pipes with integral, geometry compliant lattice structures. These compliant lattice structures offer the potential to greatly enhance heat transfer in arbitrary flow passages. This preliminary paper will focus on the development of an isothermal simulation model in OpenFOAM, to model the nature of the flow for a single unit cell, a unit cell screen, and a series of unit cell screens. Honeywell FM&T is a contractor of the U.S. Government under Contract No. DE-NA0002839.

scholarly journals Exploring Spatiotemporal Complexity of a Predator-Prey System with Migration and Diffusion by a Three-Chain Coupled Map Lattice

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Tousheng Huang ◽  
Huayong Zhang ◽  
Xuebing Cong ◽  
Ge Pan ◽  
Xiumin Zhang ◽  
...  
Keyword(s):  
Turing Instability ◽  
Coupled Map Lattice ◽  
Self Organization ◽  
Turing Patterns ◽  
Predator Prey ◽  
Migration Rates ◽  
Self Organized ◽  
Prey System ◽  
And Migration ◽  
And Diffusion

The topic of utilizing coupled map lattice to investigate complex spatiotemporal dynamics has attracted a lot of interest. For exploring the spatiotemporal complexity of a predator-prey system with migration and diffusion, a new three-chain coupled map lattice model is developed in this research. Based on Turing instability analysis, pattern formation conditions for the predator-prey system are derived. Via numerical simulation, rich Turing patterns are found with subtle self-organized structures under diffusion-driven and migration-driven mechanisms. With the variation of migration rates, the predator-prey system exhibits a gradual dynamical transition from diffusion-driven patterns to migration-driven patterns. Moreover, new results, the self-organization of non-Turing patterns, are also revealed. We find that even in the cases where the nonspatial predator-prey system reaches collapse, the migration can still drive pattern self-organization. These non-Turing patterns suggest many new possible ways for the coexistence of predator and prey in space, under the effects of migration and diffusion.

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