Effective porosity

About: Effective porosity is a research topic. Over the lifetime, 1199 publications have been published within this topic receiving 26511 citations.

Effect of the Current Density on Morphology, Porosity, and Tribological Properties of Electrodeposited Nickel on Copper

Abstract: In the steel industry, nickel coating on copper has increased the lifespan of continuous ingot casting molds. The objective of this work is to estimate the porosity of nanocrystalline nickel electrodeposited onto copper. Characteristics of nickel coating such as hardness, wear resistance, porosity, morphology, and adhesion are very important for maximum performance of molds. The effective porosity in nickel coating was determined by using anodic voltammetry. The porosity of electrodeposited nickel onto copper increased from 0.16% up to 6.22% as the current density increased from 1.5 up to 8.0 A dm−2. The morphology of the nickel electrodeposited at lower current densities was more compact. Tribological properties were studied using hardness measurements, and calotest. Results of calotest indicated a wear coefficient of 10−6 for all samples. An extremely low friction coefficient of 0.06-0.08 was obtained for the sample deposited with a current density of 1.5 A dm−2, and a friction coefficient of 0.15-0.21 was measured for the nickel coating electrodeposited at a current density of 5 A dm−2. Effects of the current density of the electrodeposition process on the morphology, porosity, and tribological properties were evaluated.

Results of Detailed Hydrologic Characterization Tests - Fiscal Year 1999

Abstract: This report provides the results of detailed hydrologic characterization tests conducted within newly constructed Hanford Site wells during FY 1999. Detailed characterization tests performed during FY 1999 included: groundwater flow characterization, barometric response evaluation, slug tests, single-well tracer tests, constant-rate pumping tests, and in-well vertical flow tests. Hydraulic property estimates obtained from the detailed hydrologic tests include: transmissivity, hydraulic conductivity, specific yield, effective porosity, in-well lateral flow velocity, aquifer flow velocity, vertical distribution of hydraulic conductivity (within the well-screen section) and in-well vertical flow velocity. In addition, local groundwater flow characteristics (i.e., hydraulic gradient and flow direction) were determined for four sites where detailed well testing was performed.

Hydraulic flow units and permeability prediction in a carbonate reservoir, Southern Iraq from well log data using non-parametric correlation

Abstract: The determination of permeability in heterogeneous and anisotropic reservoirs is a complex problem, because core samples and well test data are usually only available for limited number of wells. This paper presents hydraulic flow units and flow zone indicator for predicting permeability of rock mass from core and well log-data. The concept is applied to some uncored wells/intervals to predict their permeability. Flow zone indicator depends on geological characteristics of the material and various pore geometry of rock mass; hence it is a good parameter for determining hydraulic flow units (HFU). Flow zone indicator is a function of reservoir quality index and void ratio. We are determined flow zone indicator from well log and core data and divided the reservoir into various hydraulic flow units using K-means. Then will be develop a correlation (The Alternating Conditional Expectation (ACE) technique will be used and tested in this study) between hydraulic flow units from the core and the well log data which can be used to estimate permeability in un-cored wells, these correlations enable to estimate reservoir permeability at the "flow unit" scale. Finally, having effective porosity and flow zone indicator, permeability was calculated in each hydraulic flow unit. Results of permeability prediction based on HFU were examined for a number of wells and were compared with the measured permeability value of cores. Then will be evaluate a good correlation between the predicted and measured permeability.

Push-pull tests for estimating effective porosity: expanded analytical solution and in situ application

Abstract: The analytical solution describing the one-dimensional displacement of the center of mass of a tracer during an injection, drift, and extraction test (push-pull test) was expanded to account for displacement during the injection phase. The solution was expanded to improve the in situ estimation of effective porosity. The truncated equation assumed displacement during the injection phase was negligible, which may theoretically lead to an underestimation of the true value of effective porosity. To experimentally compare the expanded and truncated equations, single-well push-pull tests were conducted across six test wells located in a shallow, unconfined aquifer comprised of unconsolidated and heterogeneous silty and clayey fill materials. The push-pull tests were conducted by injection of bromide tracer, followed by a non-pumping period, and subsequent extraction of groundwater. The values of effective porosity from the expanded equation (0.6–5.0%) were substantially greater than from the truncated equation (0.1–1.3%). The expanded and truncated equations were compared to data from previous push-pull studies in the literature and demonstrated that displacement during the injection phase may or may not be negligible, depending on the aquifer properties and the push-pull test parameters. The results presented here also demonstrated the spatial variability of effective porosity within a relatively small study site can be substantial, and the error-propagated uncertainty of effective porosity can be mitigated to a reasonable level (< ± 0.5%). The tests presented here are also the first that the authors are aware of that estimate, in situ, the effective porosity of fine-grained fill material.