Pore Distribution Characteristics Research Articles

Chloride corrosion resistance of underwater repair concrete in terms of the cutting effects of hydrostatic pressure

The paper presents the results of the study of underwater repair concrete under the effect of the salt mist. The research was conducted in accordance with the standard PN-EN 14147. Concrete samples for testing the corrosive elements of that test were taken during the first 7 days of insight in the pressure vessel and were subjected to hydrostatic pressure effects from 0,1 to 0,5 MPa. The beneficial effect of hydrostatic pressure on the corrosion resistance of tested concrete repair was. Was observed samples taken from the surface layers of the tested elements showed slightly higher resistance to chlorides which confirmed the characteristics of pore distribution of concrete in the studies.

Anisotropic Variation Characteristics of Pore Distribution Based on Saturated Clay Microstructure

The pore characteristics of saturated clay sourced from microstructure pictures in Pearl River Delta region of south China is analyzed considering the microstructure in different sample sections. The histogram statistics are compared with each other by pore data in terms of the size, the shape and the arrangement of link status. The repercussions of including the anisotropy ratio law of pore characteristics are focused to study saturated clay. It is found that the analysis considering anisotropy ratio results in consolidation by pore distribution based on saturated clay microstructure. The soil porosity of horizontal section was larger than that of vertical section. Vertical section status induced the directional property, and it would be presented directional probability entropy which is able to calculating the chaos of overall arrangement which is a lower value because of directional property.

Microscopic analysis of saturated soft clay in Pearl River Delta

A series of researches were carried out for the soil samples in the Pearl River Delta under the action of consolidation loads, such as the quantitative analyses of the pore scale, shape and size distributions of micro-structure units, with an environmental scanning electron microscope (ESEM), a mercury intrusion analyzer and a mineral diffractometer. The experimental results show that the consolidation pressures remarkably change the pore sizes and distribution characteristics of the silt, thus changing its compressibility and permeability. This can be proved by the fact that, in the earlier stage with a consolidation pressure of p 200 kPa, the pore sizes are smaller and the compressibility and permeability coefficients are less. Therefore, the empirical formulas of compression coefficient and permeability coefficient vs consolidation load and average pore diameter are deduced.

Humidity control porous ceramics prepared from waste and porous materials

This study investigated the feasibility of generating humidity control porous ceramics by sintering a mixture of volcanic ash, weathered volcanic ash, and waste glass. The sintering conditions, including sintering time, sintering temperature, and various mixed portions of glass amendment, were tested. The final ceramics were analyzed for their pore distribution, pore volume, adsorption and desorption characteristics, and bending strength. The results indicate that the pore size of the volcanic ash ceramics tends to distribute in the range from 70 to 100 nm, whereas that of the weathered volcanic ash ceramics is in the range of 7–9 nm. The humidity controlling conditions of the ceramics take advantage of the inherent porosity of the natural materials. The bending strengths in both cases were all satisfying with the fractural intensity specification of ceramics (> 6 Mpa).

Effect of sandwich configuration of ultrafiltration membranes on protein fractionation

Protein fractionation using ultrafiltration is feasible after extensive process optimization, yet the poor selectivity of membranes is still one of the critical factors limiting the application of membrane systems to protein fractionation. Our present work on protein fractionation uses sandwich ultrafiltration membranes by exploiting the membrane pore size and the pore distribution characteristics of the membranes. The aim is to improve the selectivity of the separation by achieving a pure protein product in the permeate from a binary protein mixture. Two membranes of similar or different MWCO combination (30, 50 and 100 kDa) are stacked together in various sandwich arrangements. The proteins with molecular weight between 10 and 70 kDa (Lysozyme, Myoglobin and BSA) are used as model proteins in single and binary mixtures. The observed transmissions of Lysozyme with sandwich of the same membrane of 30/30, 50/50, and 100/100 kDa are 78, 85 and 97%, respectively; and these values are comparable to the transmission for the respective single membrane, being consistently slightly lower. Similar trends are being found for BSA.

00/03048 Statistical characteristics of pore distribution in activation of gas coal

00/03048 Statistical characteristics of pore distribution in activation of gas coal

Preparation of silica gels in electrostatic field

The investigation is focused on the pore distribution and morphology of the gels prepared under electrostatic fields from hydrochloric acid-catalyzed TEOS (tetraethyl orthosilicate) systems (acetone as solvent). Hydrochloric acid of 1.0 and 0.6 M, and electrostatic field of 3kV/52mm and 3kV/8mm were adopted. The sols were put in electrostatic fields after certain minutes of stirring, and the acquired wet gels were moved away for aging when gelation finished. After aging in sealed containers for a week, they were dried in ambient condition, and additionally some of them were calcinated at 600°C after drying. SEM analyses showed that these xerogels had variant pore distribution or distinct morphological characteristics, which were related to the direction of electric field and could be attributed to the influence of electrostatic field on the redistribution of colloidal particles and water, and that xerogels with gradient pore distribution might be expected if proper parameters were adopted.

Expulsion and primary migration of the oil derived from coal

The characteristics of coal pores and the interaction relationship between hydrocarbons and pores in coal are analysed based on the typical example of oil from coal in Tuha Basin, pointing out that the interaction between hydrocarbon molecules and coal pore surface particles is a major controlling factor of expulsion of oil from coal. Distribution characteristics of coal pores and the ability of hydrocarbon generation are inner factors of the expulsion of the oil from coal; tectonic compressive shear stress is an external force of the expulsion of oil from coal; expulsion of the oil from coal has greater geochromatographic effect than that from mudstone, the low mature stage (or vitrinite reflectance Ro is less than 0.9%) is advantageous to the coal-formed oil expulsion and migration; hydrocarbons in the hydrocarbon network are linked with carrier beds (such as fault), through the pore network and fissure which are connected with each other, which constitutes the main pathway of expulsion and migration.

Effect of additives on the microstructure and mechanical properties of commercial alumina ceramics

The effect of impurities or additives on the microstructure of some commercial alumina ceramic samples have been characterized by scanning electron microscope-energy dispersive x-ray spectrometer and the mechanical properties investigated. Both the hardness and the toughness have been found to increase as the SiO 2 content decreases, and the theoretical density is reached in these materials. Grain size and distribution seem to be important factors in the mechanical properties of alumina ceramics. If the additives are controlled carefully, finer grain size and distribution can be obtained, together with a high relative density in terms of pore distribution characteristics and consequently enhanced mechanical properties.

Investigation on the textural characteristics of supported nickel hydrogenation catalysts

AbstractNickel catalysts supported on a range of carriers such as kieselguhr, silica, γ‐alumina, silica‐alumina and mordenite were investigated in order to gain an understanding of their structural properties. The surface area and pore distribution characteristics of the carriers and unreduced catalysts obtained from nitrogen adsorption isotherms gave strong indications that the formation of the nickel salt submerged the carrier. Metallic nickel produced after reduction at high temperature was perhaps present in the macropores or on the outer surface of the carrier forming a microporous network of fine crystallites. The metal surface area of the catalyst in its reduced state, calculated from hydrogen chemisorption data, was not influenced by the specific surface area of the carrier. Among the different carriers, the nickel‐carrier interaction was mainly found with kieselguhr and silica. Activity of the different catalysts in the hydrogenation of unsaturated fatty acid was found to be directly related to the metal area.