“Time”-Parallel diffusion-based correlation operators

2018 ◽  
Vol 144 (716) ◽  
pp. 2067-2088 ◽  
Author(s):  
Anthony T. Weaver ◽  
Selime Gürol ◽  
Jean Tshimanga ◽  
Marcin Chrust ◽  
Andrea Piacentini
Keyword(s):  
Parallel Diffusion

scholarly journals Simple quality control technique to identify dissolved oxygen diffusion issues with biochemical oxygen demand bottle incubations

2017 ◽  
Author(s):  
Johnathan Daniel Maxey ◽  
Neil David Hartstein ◽  
Dorathy Penjinus ◽  
Alan Kerroux
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Freshwater Ecosystems ◽  
Control Technique ◽  
Community Respiration ◽  
Parallel Diffusion ◽  
Quality Control Technique

Stratified estuaries are home to expanding aquaculture activities whose ecological footprints can be observed through trends in microbial community respiration in the water column. Bottle incubations are widely used to measure water column community respiration in marine and freshwater ecosystems by measuring the flux of dissolved oxygen occurring in the bottle over a period of time. When in situ dissolved oxygen (DO) concentrations are markedly different than DO concentration of the incubation medium the potential for diffusion of oxygen across the bottle opening is great and may be especially pronounced in strongly stratified systems with relatively low rates of pelagic oxygen consumption. We incubated 60 Biochemical Oxygen Demand (BOD) bottles filled with sterilized water with DO concentrations ranging from 2.51 mg O2 L-1 to 10.03 mg O2 L-1 for 24 hours in a temperature controlled water bath. There was a significant relationship when DO flux was set as a function of initial DO (DO Flux = -0.0017x + 0.0085, r2 = 0.72, p < 2.2 e-16). DO fluxes ranged from -0.012 mg O2 L-1 hour-1 to 0.005 mg O2 L-1 hour-1 for bottles incubated with initial DO ranging from 10.03 mg O2 L-1 to 3.31 mg O2 L-1, respectively. These results suggest that diffusion across the ground glass seal of BOD bottles is possible and that extra precaution through parallel diffusion controls should be considered when measuring pelagic respiration using BOD bottle incubations in systems with relatively low or relatively high in situ DO concentrations.

A SINGULAR PERTURBATION PROBLEM IN FRACTURED MEDIA WITH PARALLEL DIFFUSION

1998 ◽  
Vol 08 (04) ◽  
pp. 645-655 ◽  
Author(s):  
J. DAVID LOGAN ◽  
GLENN LEDDER ◽  
MICHELLE REEB HOMP
Keyword(s):  
Boundary Condition ◽  
Singular Perturbation ◽  
Porous Matrix ◽  
Fractured Media ◽  
Singular Perturbation Problem ◽  
Single Fracture ◽  
Direction Parallel ◽  
Flux Boundary Condition ◽  
Perturbation Problem ◽  
Parallel Diffusion

We study differential equations that model contaminant flow in a semi-infinite, fractured, porous medium consisting of a single fracture channel bounded by a porous matrix. Models in the literature usually do not incorporate diffusion in the porous matrix in the direction parallel to the fracture, and therefore they must omit a no-flux boundary condition at the edge, which, in some problems, may be unphysical. Herein we show that the problem usually treated in the literature is the outer problem for a correctly posed singular perturbation problem which includes diffusion in both directions as well as the no-flux boundary condition.

Dynamics of a Resistive Sheet Pinch

1982 ◽  
Vol 37 (8) ◽  
pp. 840-847 ◽  
Author(s):  
D. Biskamp
Keyword(s):  
Mhd Equations ◽  
Magnetic Islands ◽  
Final State ◽  
Flux Function ◽  
Tearing Modes ◽  
Parallel Diffusion ◽  
Strong Shear ◽  
Resistive Sheet ◽  
Special Distribution ◽  
The Difference

The dynamic evolution and the saturated state of a long sheet pinch subject to growth of resistive tearing modes was investigated by numerical solution of the 2D MHD equations. Both the compressible and the incompressible equations were used, and the difference is found to be negligible. The necessity of considering a resistive equilibrium is stressed. The paper concentrates on a static equilibrium maintained by an external electric field and requiring a special distribution of the resistivity η. In addition the dynamics of the resistivity plays an important part. Assuming η to be time independent, the sheet pinch develops a number of soliton-like magnetic islands, which coalesce. The final state consists of a single soliton, while the generation of further sol-itons is inhibited by a strong shear flow allong the current sheet. When allowance is made for parallel diffusion of the resistivity such that η is essentially a flux function, the final state is quite different. Here the longest wavelength dominates, leading to a single, large island and completely destroying the original sheet pinch

scholarly journals THE PARALLEL DIFFUSION COEFFICIENT AND ADIABATIC FOCUSING OF COSMIC-RAY PARTICLES

2011 ◽  
Vol 745 (1) ◽  
pp. 62 ◽  
Author(s):  
Yuri E. Litvinenko
Keyword(s):  
Diffusion Coefficient ◽  
Cosmic Ray ◽  
Parallel Diffusion

scholarly journals Diffusion Coefficients, Short-Term Cosmic Ray Modulation, and Convected Magnetic Structures

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
John J. Quenby ◽  
Tamitha Mulligan ◽  
J. Bernard Blake ◽  
Diana N. A. Shaul
Keyword(s):  
Diffusion Coefficients ◽  
Particle Interaction ◽  
Flux Rope ◽  
Cosmic Ray ◽  
Magnetic Scattering ◽  
High Data ◽  
Cosmic Ray Modulation ◽  
Parallel Diffusion ◽  
Data Rates ◽  
Ray Diffusion

Three cases of large-amplitude, small spatial-scale interplanetary particle gradients observed by the anticoincidence shield (ACS) aboard the INTEGRAL spacecraft in 2006 are investigated. The high data rates provided by the INTEGRAL ACS allow an unprecedented ability to probe the fine structure of GCR propagation in the inner Heliosphere. For two of the three cases, calculating perpendicular and parallel cosmic ray diffusion coefficients based on both field and particle data results in parallel diffusion appearing to satisfy a convection gradient current balance, provided that the magnetic scattering of the particles can be described by quasi-linear theory. In the third case, perpendicular diffusion seems to dominate. The likelihood of magnetic flux rope topologies within solar ejecta affecting the local modulation is considered, and its importance in understanding the field-particle interaction for the astrophysics of nonthermal particle phenomena is discussed.

Effects of sulfonated surfactants on parallel diffusion of mono azo dye with high aggregation constant into cellulose membranes

2001 ◽  
Vol 83 (8) ◽  
pp. 1781-1785 ◽  
Author(s):  
Masako Maekawa ◽  
Chiyo Kamada ◽  
Kiyomi Miyata
Keyword(s):  
Azo Dye ◽  
Parallel Diffusion ◽  
Cellulose Membranes

Novel 3D GPU based numerical parallel diffusion algorithms in cylindrical coordinates for health care simulation

2015 ◽  
Vol 109 ◽  
pp. 1-19 ◽  
Author(s):  
Beini Jiang ◽  
Weizhong Dai ◽  
Abdul Khaliq ◽  
Michelle Carey ◽  
Xiaobo Zhou ◽  
...  
Keyword(s):  
Health Care ◽  
Cylindrical Coordinates ◽  
Parallel Diffusion

Determination of the optimum resultant effect of factors influencing HETP-valuesThe following of parallel diffusion and mass-transfer processes

Talanta ◽  
1970 ◽  
Vol 17 (12) ◽  
pp. 1175-1182 ◽  
Author(s):  
J. Takács ◽  
L. Mázor ◽  
M. Kucsera-Pápay ◽  
T. Kozma
Keyword(s):  
Mass Transfer ◽  
Transfer Processes ◽  
Factors Influencing ◽  
Parallel Diffusion ◽  
Mass Transfer Processes ◽  
Resultant Effect
Sign in / Sign up

Export Citation Format

Share Document