scholarly journals Determination of transport properties from flowing fluid temperature logging in unsaturated fractured rocks: Theory and semi-analytical solution

2008 ◽  
Vol 44 (10) ◽  
Author(s):  
Sumit Mukhopadhyay ◽  
Yvonne W. Tsang
Keyword(s):  
Analytical Solution ◽  
Transport Properties ◽  
Fractured Rocks ◽  
Fluid Temperature ◽  
Flowing Fluid

scholarly journals A Simple Method for the Determination of Deposition Coefficient Using the Analytical Solution of Advection-Dispersion-Deposition Equation for Step Input

Water ◽  
2017 ◽  
Vol 9 (6) ◽  
pp. 398
Author(s):  
Nag-Choul Choi ◽  
Jae-Woo Choi ◽  
Kyu-Sang Kwon ◽  
Sang-Gil Lee ◽  
Bong-Ju Kim ◽  
...  
Keyword(s):  
Analytical Solution ◽  
Simple Method ◽  
Step Input ◽  
Advection Dispersion ◽  
Deposition Coefficient

Radiation and Convection Heat Transfer in a Porous Bed

1968 ◽  
Vol 90 (1) ◽  
pp. 51-54 ◽  
Author(s):  
W. A. Beckman
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Collection Efficiency ◽  
Convection Heat Transfer ◽  
Heat Fluxes ◽  
Fluid Temperature ◽  
Radiation Heat ◽  
Radiation Heat Flux ◽  
Flowing Fluid ◽  
Porous Bed

The one-dimensional steady-state temperature distribution within an isotropic porous bed subjected to a collimated and/or diffuse radiation heat flux and a transparent flowing fluid has been determined by numerical methods. The porous bed was assumed to be nonscattering and to have a constant absorption coefficient. Part of the radiation absorbed by the porous bed is reradiated and the remainder is transferred to the fluid by convection. Due to the assumed finite volumetric heat transfer coefficient, the bed and fluid have different temperatures. A bed with an optical depth of six and with a normal incident collimated radiation heat flux was investigated in detail. The radiation incident on the bed at the fluid exit was assumed to originate from a black surface at the fluid exit temperature. The investigation covered the range of incident diffuse and collimated radiation heat fluxes expected in a nonconcentrating solar energy collector. The results are presented in terms of a bed collection efficiency from which the fluid temperature rise can be calculated.

scholarly journals A Novel Method for Designing Fifth-Generation District Heating and Cooling Systems

2021 ◽  
Vol 246 ◽  
pp. 09001
Author(s):  
Marwan Abugabbara ◽  
Jonas Lindhe
Keyword(s):  
Analytical Solution ◽  
District Heating ◽  
Innovative Technology ◽  
Complete Agreement ◽  
Fluid Temperature ◽  
Existing Buildings ◽  
Cooling Systems ◽  
Heating And Cooling ◽  
Fifth Generation ◽  
Novel Method

District heating and cooling systems have been undergoing continuous development and have now reached the fifth-generation. In this innovative technology, connected buildings share local excess energy that otherwise would be wasted, which consequently reduces primary energy demands and carbon emissions. To date, the issue of implementing fifth-generation district systems on existing buildings has received scant attention, and our research addresses this challenging gap by proposing a novel method for designing these systems. We first explain the possible thermal interactions between connected buildings, and then present an analytical solution for the network energy balance, pipe design, and the prediction of fluid temperature under a fixed temperature difference control strategy. The analytical solution was validated against numerical simulations performed on 11 existing buildings located in Lund, Sweden using Modelica models. A diversity index metric between heating and cooling demands was also included in these models to assess the efficiency of the district system in the building cluster. The results from the analytical and numerical solutions were in complete agreement since Modelica is an equation-based modelling language. The developed models pave the way towards future investigations of different temperature control strategies and new business models that arise from the shift to the fifth-generation.

Analytical Determination of Generation-Recombination Rate In Amorphous Silicon

1986 ◽  
Vol 70 ◽  
Author(s):  
Jože Furlan ◽  
Slavko Amon
Keyword(s):  
Analytical Solution ◽  
Amorphous Silicon ◽  
Cross Sections ◽  
Recombination Rate ◽  
Exponential Model ◽  
Localized States ◽  
Analytical Determination ◽  
Capture Cross ◽  
Capture Cross Sections

ABSTRACTA general expression for generation-recombination rate in a-Si based on classical SRH theory including different electron and hole capture cross-sections for donor-like and acceptor-like centers inside the mobility gap is derived. Applying appropriate approximations and two-exponential model for localized states distribution two methods of analytical solution are presented and discussed.

scholarly journals FIELD DETERMINATION OF SOIL HYDRAULIC AND CHEMICAL TRANSPORT PROPERTIES 1

Soil Science ◽  
2002 ◽  
Vol 167 (6) ◽  
pp. 353-368 ◽  
Author(s):  
Salem A. Al-Jabri ◽  
Robert Horton ◽  
Dan B. Jaynes ◽  
Anju Gaur
Keyword(s):  
Transport Properties ◽  
Chemical Transport ◽  
Soil Hydraulic

scholarly journals Ionic Transport Properties of P2O5-SiO2 Glassy Protonic Composites Doped with Polymer and Inorganic Titanium-based Fillers

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3004
Author(s):  
Maciej Siekierski ◽  
Maja Mroczkowska-Szerszeń ◽  
Rafał Letmanowski ◽  
Dariusz Zabost ◽  
Michał Piszcz ◽  
...  
Keyword(s):  
Transport Properties ◽  
Continuous Wave ◽  
Electrochemical Impedance ◽  
Pore Space ◽  
Poly Vinyl Alcohol ◽  
Proton Mobility ◽  
Polymeric Additives ◽  
Wave Technique ◽  
Poly Ethylene

This paper is focused on the determination of the physicochemical properties of a composite inorganic–organic modified membrane. The electrical conductivity of a family of glassy protonic electrolytes defined by the general formula (P2O5)x(SiO2)y, where x/y is 3/7 are studied by Alternating Current electrochemical impedance spectroscopy (AC EIS) method. The reference glass was doped with polymeric additives—poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA), and additionally with a titanium-oxide-based filler. Special attention was paid to determination of the transport properties of the materials thus modified in relation to the charge transfer phenomena occurring within them. The electrical conductivities of the ‘dry’ material ranged from 10−4 to 10−9 S/cm, whereas for ‘wet’ samples the values were ~10−3 S/cm. The additives also modified the pore space of the samples. The pore distribution and specific surface of the modified glassy systems exhibited variation with changes in electrolyte chemical composition. The mechanical properties of the samples were also examined. The Young’s modulus and Poisson’s ratio were determined by the continuous wave technique (CWT). Based on analysis of the dispersion of the dielectric losses, it was found that the composite samples exhibit mixed-type proton mobility with contributions related to both the bulk of the material and the surface of the pore space.

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