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Diffusion equations such as Darcy's equation which is used to measure the permeability coefficient of concrete has a one-dimensional limitation. If the water penetrates into the concrete in a multi-dimensional way. Therefore, there is a need for equations that measure the permeability coefficient of concrete either in a multi-dimensional way or without considering things like one-dimensional, two-dimensional or three-dimensional. Also, acute environmental conditions such as different cycles of ice and ice melting have a negative effect on concrete and especially on the surface of concrete. Therefore, in this article, according to the fractal theory, a new theoretical relationship has been presented that measures the permeability coefficient of concrete without the need for permeability dimensions. Also, the relationship between the surface resistance of concrete and its permeability coefficient in the conditions of ice and ice melting has been investigated by using pull tests from the surface and cylindrical chamber. Cylindrical chamber test is a new test invented by Mahoud Naderi. This test is very simple and has a portable device. The above test has the ability to measure the permeability of concrete in situ. Using this test, it is possible to measure the permeability of water into the concrete without breaking the concrete. To perform the above test, a steel plate must be glued on the concrete surface using epoxy resin glue. The desired adhesive must have the required compressive and shear strength so that no water leaks around it during the test. After that, the cylindrical container should be placed on the steel plate and water should be poured into it. Then, by using the handle on the device, the required pressure is applied to the water so that the water penetrates into the concrete. In the "direct tension" test to determine the surface resistance of concrete, first a metal cylinder with a diameter of 5 cm is attached to the place of the test using epoxy resin glue, then by using the "direct tension" device, the tensile force is applied to the cylinder. It is inserted to separate from the concrete surface. According to the existing relationship, the resistance value obtained by the "direct tension" method is obtained by dividing the tension force applied by the area of the cylinder. The direct tensile test can also be performed in situ. In addition, unlike the previous theories, the new theory has the ability to investigate the effect of processing time on the permeability coefficient. The obtained results show the high accuracy of the presented model for measuring the permeability coefficient of concrete. Also, the acute conditions of ice and ice melting have a negative effect on the permeability coefficient of concrete, and an inverse relationship between the permeability coefficient of concrete and the surface resistance obtained from the pull-out test was observed. With the increase in the number of acute cycles of ice and ice melting, the permeability of concrete also increases, which shows the negative effect of these conditions on concrete. Also, a great agreement between the theoretical and experimental results was observed.

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Research subject: Selectivity and permeability are the major parameters of polymeric membranes in gas separation process. Hence, nowadays in order to improve aforementioned parameters, modification and enhancement issues for such membrane have been highly noticed.
Research approach: In this study, in order to improve the performance of polymeric membranes, the two-component blend membranes containing Pebax^®1657 and PVA were synthesized for CO₂ separation. The effect of different PVA concentrations within the Pebax matrix on structure, morphology and gas separation properties of resultant membranes was investigated. The chemical bonds, crystallinity and cross-sectional morphology studied through, Fourier transform infrared (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), and were utilized.
Main results: The results of the thermal analysis indicated an increase in crystallinity and also glass transition temperature in presence of 5 – 15 wt.% PVA, while the membrane crystallinity decreased by increasing the PVA content up to 20 wt.%. FESEM images demonstrated a uniform cross-section without any cracks and defects for neat Pebax membrane but by adding PVA to Pebax matrix, appeared cracks and cave structures on the cross- section of blend membranes. The CO₂/CH₄ separation performance of membranes was measured using a constant volume set up at 30°C and feed pressure of 2, 6 and 10 bar. The obtained results revealed that the CO₂ permeability in blend membranes improved as the PVA content increased within the membrane. The best obtained CO₂ permeability was 204.64 Barrer which gained by Pebax/PVA (20wt.%) at feed pressure of 10 bar. Moreover, the highest selectivity of CO₂/N₂ for blend membrane with 15 wt.% of PVA was about 100.21 at 10 bar and 30°C.
 

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In this paper two nodes to model isotropic and anisotropic media in Transmission Line Matrix Method (TLM) are presented. By using these two nodes, the permeability and permittivity of an anisotropic media can be modeled simultaneously. Another application of these nodes is in modeling media with permittivity and permeability less than one. In the conventional 2 dimensional TLM, the stubs representing permittivity and or permeability get negative characteristic impedances, which in turn cause instability in the computation. Studying the two suggested nodes, called the stub node and the hybrid node, respectively, shows the hybrid node can best model the simultaneous variations of permeability, permittivity of the isotropic and non isotropic media.

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Abstract
Research subject: Nanocomposites are a new class of materials that have at least one of their major constituents, at least in one dimension, in the range of one to one hundred nanometers. Typically, nanocomposites have different and superior properties in terms of mechanical and physical properties than conventional composites.
Research approach: In this study, polyvinyl acetate was prepared by emulsion polymerization for polymer matrix. Then the diamond nanoparticles were modified with silane agent. Finally, polyvinyl acetate / diamond nanocomposite was prepared and analyzed with 0.5, 1, 1.5 and 2 wt% of modified diamond nanoparticles. To determine the properties and structure of the nanocomposite, FTIR, TGA, RMS, FESEM, oxygen permeation analysis was used in the films produced and contact angle measurements.
Main results: FTIR Analysis revealed that the modification of the diamond nanoparticles with the silane agent was well performed. FESEM images show that homogeneous nanocomposites were created. Oxygen permeability in polyvinyl acetate / diamond nanocomposite film decreases with increasing percentage of modified nanoparticles in nanocomposite. This is a valuable property if this nanocomposite is used as a fruit preservative coating. Contact angle measurement of polyvinyl acetate / diamond nanocomposite showed that by increasing the amount of modified diamond nanoparticles from 0.5 to 2 wt %, the hydrophobicity of nanocomposite film increased. Therefore, by increasing the specific amount of nanoparticles to the polymer matrix, the polymer properties such as heat resistance and tensile strength are increased which increases the efficiency of the polymer.

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Pedological criterion affecting desertification in alluvial fans was investigated, for which the map of units was prepared by crossing maps of land use, geology, slope classes and grid layer created by the extension of ET Geo-Wizards in ArcGIS 10.3. Three indices of salinity, erodibility, and permeability of soil were considered and classified. Weights of criteria and consistency ratio were calculated by the AHP method and ELECTRE I method was used to prioritize the options. After creating the weighted super matrix and calculating the concordance and discordance matrix, the difference between dominance and defeat values were calculated. The results showed that the difference in values obtained from AHP-ELECTRE I technique varied from -15 to 16. The alluvial fans were classified into three classes of I, III, and IV from the viewpoint of pedological criterion affecting desertification by using AHP-ELECTRE I technique. Results showed that 71.99% of the area was in the low desertification potential, while 2.19% and 25.82% were in the high and very high desertification potential, respectively.

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Research subject: Nanomaterials are substances that, because of their size, can easily penetrate small pores and apply their impact. Nanofluids can allow appropriate wettability change in the reservoir rock, therefore, an accurate understanding of the behavioral mechanisms of these nanofluids is important in changing the wettability. This is because if there is no proper understanding of these mechanisms, they may exhibit the opposite behavior and cause damage to the reservoir. In previous research, CuO / TiO2 / PAM nanocomposite was synthesized and mechanistically introduced.
Research approach: In this study, in continuation of the previous study, the behavioral and mechanism study has been investigated in a more accurate and documented manner, and spectral absorption tests, chemical flooding, and relative permeability diagrams confirm the effectiveness of enhanced oil recovery results of this nanocomposite. In carbonate rocks due to the positive surface charge of the rock and the negative charge of the nanocomposite, adsorption of nanomaterials in a double electrode layer state has been suggested as the dominant mechanism of wettability change. In sandstone rocks due to the charge coincidence of rock surface and nanomaterials which are both negative, the mechanism of disjoining pressure was the dominant mechanism of wettability change. To prove the abovementioned behaviors 200 ppm concentration of nanofluid was analyzed by spectroscopy method of adsorption analysis to validate the attraction forces of the nanocomposite with carbonate rocks and repulsion forces with sandstones.
Main results: Dynamic chemical flood tests were performed to confirm the effectiveness of this material in increasing oil production and showed 8.5% and 6.35% increase in oil production for carbonate and sandstone lithologies, respectively. Relative permeability diagrams showed an intersection point in the carbonate system with a 10% increase in water saturation and an intersection point in the sandstone system with a 12% increase in water saturation and the behavioral effect of the material at the studied concentrations.

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  Research subject: Investigation of the effect of temperature on the polymer flooding performance at the pore scale, leads to an understanding of the behavior of the polymer solution in porous media with varying permeability.
Research approach: In this study, the effect of temperature on flooding of polyacrylamide polymer on enhanced oil recovery in two homogeneous micromodels at 25 and 70 °C was investigated. The polymer solution and DW were injected at the injection rate of 1 μl/min up to 1 PV into the micromodel and the amount of produced oil and the movement of the injected fluid in the porous medium were analyzed. In addition, polymer rheology and injected fluid viscosity were measured for better analysis of results. Then the results were compared with flooding of distilled water as the control test.
Main results: Examining the flood results, it was found that on the one hand, the temperature factor helped to increase oil recovery by reducing the viscosity of the oil. On the other hand, it has reduced the role of injected fluid viscosity in oil extraction by reducing the viscosity of the polymer. The results showed that the phenomenon of fingering decreases in the case of polymer injection, and the rate of improvement of oil recovery during polymer and water flooding in both micromodels increases with increasing temperature. Also, the rate of improvement of oil recovery during polymer flooding in the A micromodel increased from about 43% at ambient temperature to more than 51% and in the B micromodel from about 51% to more than 60% at 70 °C. In fact, it can be said that the flow pattern and stability of the polymer solution front and consequently the ultimate oil recovery are significantly affected by the morphology of the pores, the shape and the throats pores.
    

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The objectives of this study were to investigate the potential of faba bean protein isolate (FPI) in preparation of an edible film and to determine the effects of film forming solution pH and plasticizer concentration on film properties. So film samples were prepared in three different pH levels (7, 9 and 12) and plasticizer concentrations (40, 50 & 60% w/w protein isolate). Results showed that increasing of pH improved mechanical properties (tensile strength and elongation) and solubility of films but caused water vapor permeability (WVP) and lightness of films to decrease. Plasticizer concentration did not affect WVP over the studied range. Elongation and solubility of films increased and tensile strength decreased by increasing of plasticizer content of film forming solutions. The lowest WVP and the highest tensile strength was observed at pH 12 and 40% (w/w of FPI ) glycerol concentration.

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  Starch is the most abundant carbohydrate biopolymer that has excellent film-forming properties. But poor resistance to water vapour transport and poor mechanical properties are of its main problems. In this study a series of corn starch films with varying concentrations (0–20 %W/W) of citric acid and carboxymethyl cellulose (CMC) were prepared by casting method at 60˚C. The effects of citric acid on water vapor permeability (WVP), moisture absorption, solubility and mechanical properties were investigated. The WVP decreased from 4.63 to  2.61×10^-7 g/m.h.Pa as the citric acid percentage increased from 0 to 10%W/W. When the citric acid content of the films reached to 20%W/W, WVP increased about 15%. Moisture absorption and mechanical properties exhibited similar trends. In the presence of 10% citric acid, the introduction of CMC improved the moisture resistance of the composites. Using of 20%W/W CMC in the formulation increased ultimate tensile strength (UTS) by more than 59% compared to neat starch film. However, by increasing of the CMC concentration, the strain to break (SB) did not reduce significantly. 

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Edible emulsified films were made from pistachio globulin protein (PGP) (6 g/100ml), stearic fatty acid (SA) (2, 4 and 6% w/w protein), glycerol (1g/1g of protein), and emulsifier by emulsification method in order to improve water vapor permeability (WVP) and reduce water solubility of protein film. WVP of films reduced 38.5 to 42% by fatty acid addition and water solubility decreased slightly, too. Effect of SA on the oxygen permeability (OP) of emulsified films was determined indirectly by oil peroxide value measurements. OP values of the emulsified films were lower than that of PGP film, but the differences were not significant (P>0.05). Tensile strength (TS) and elongation at break (E) of PGP film were 9 Mega Pascal and 104%, respectively. TS and E of emulsified films were diminished 11 to 41% and 35 to 70%, respectively as a result of SA addition. Opacity of emulsified films (unfavorable sensory attribute) increased as function of SA concentration. Glass transition temperature (Tg) of films was measured by differential scanning calorimetry. Tg of PGP film was at 127.19 °C and was not affected considerably by the SA addition.

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Due to disadvantages of synthetic packaging materials such as migration into food, polluting of environment, difficulty of recovery, high costs of raw materials and production, also modifying properties of starch based edible film, in this study different kinds of edible films from starch and tragacanth (Iranian gum) will be formulated and their properties investigated.  In this regard, edible films formulated by mixing potato starch, tragacanth (1-5%), Glycerol plasticizer (10-40%) and sunflower oil (0-20%), then the film mechanical (tensile strength and elongation), optical, solubility and water vapor permeability (WVP) properties measured. The results showed that physical and mechanical properties of potato starch-based edible films were affected by the content of tragacanth, glycerol and sunflower oil. The tragacanth gum increased tensile strength and reduced chroma, while glycerol reduced tensile strength and increased elongation at break. Also, the sunflower oil decreased solubility and water vapor permeability and increased elongation. Finally, amounts of 2% tragacanth, 30% glycerol and 17% sunflower oil were determined as optimum points for production of starch based edible films with optimum properties.  

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   Edible coating are thin layers that are on surface of food materials and they are such as protector. Films and edible coating which are prepared from natural polymers specially protein are under consideration in recently years. Aim of this search, is possibility of production of edible film from chickpea protein isolated and determinate the effect of chickpea protein isolated concentration and plasticizer percent on some properties of edible film. So was considered with using from central composite design of chickpea protein isolated in concentrations 4 -10 g, and glycerol plasticizer in range of 40- 60% of weight of chickpea protein isolated in pH=9.5. In this study was considered physical and qualitative examination like water vapor permeability, film solubility, transparency of edible films. Results showed that percent of plasticizer in experiments had right effect on water vapor permeability; thus increasing of protein concentration was caused increasing of water vapor permeability measure at statistical surface (P<0.01). the increase of plasticizer concentration, is caused solving  of films and increase of protein isolated concentration is caused to decrease of transparency of edible films.  

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Emulsion coatings were formulated and films were developed using tragacanth gum as the basic structural component. Preliminary experiments were carried out to determine the proper concentration of tragacanth gum, lipid and plasticizers in the film. The effects of different concentrations of tragacanth gum (0.65, 1, 1.5, 2, 2.35 g /g distilled water), canola oil (23, 30, 40, 50, 58 g/g tragacanth dry wt basis) and glycerol (33, 40, 50, 60, 67 g/g tragacanth dry wt basis) on water vapor permeability (WVP), mechanical properties and opacity (OP) of the films were evaluated using the response surface methodology. WVP was observed in the range of  (2.05-36) x 10^-11 and increased by tragacanth and glycerol concentration and was decreased by oil concentration. Tensile strength and elongation at break ranged between 0.67-7.15 Mpa and 1.99 – 7.8%; respectively. Increasing the amount of tragacanth gum and decreasing the glycerol and oil concentration increased tensile strength (TS) while elongation at break (EB) increased by increasing both tragacanth and glycerol concentration and decreased by increasing oil concentration. Oil was the most influential factor that affected opacity, which increased with increasing oil concentration. Models developed for WVP, EB, TS and OP had high coefficient of multiple determination (R²) values (0.983, 0.952, 0.824, 0.94) respectively.

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Abstract: The influence of aggregate gradation on the permeability and mechanical properties of porous concrete was investigated. A standard mix and five standard aggregate gradations were selected. Since porous concrete contains no or little fine aggregate, its structure is formed by the interlocking of the coarse aggregates. So the aggregate gradation is a very important characteristic as it influences such properties of porous concrete as strength and permeability. There was statistically significant difference between the results from the strength and water permeability of porous concrete with different aggregate gradations. For example, the difference between minimum and maximum compressive strength was 33%, and a 20% difference was obtained for flexural strength. It was found that the uniformity coefficient has influence on the flexural strength of porous concrete. In order to develop the flexural bending strength prediction model, the two parameters of compressive and uniformity coefficient were explained using linear regression model. The obtained Goodness of fit (R2) for this model was 0.879. The results of the current investigation showed how fine aggregate influenced the compressive and permeability of porous concrete.

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The objective of this study was to investigate the effect of different glycerol concentrations (15, 30, 45, 60 & 75% w/w of methylcellulose) and film thickness (15, 30 & 60µm) on methylcellulose (MC) films water vapor permeability and mechanical properties. Finally, 15µm films containing 45% glycerol (the best conditions) were selected. Results showed the significant effect of glycerol concentration on films water vapor barrier and mechanical properties. Film thickness affected WVP and tensile strength but not elongation at break.  

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In this paper, the normal flow permeability of an ordered fibrous structure, with square cross section is determined analytically. Porous structure is represented by a “unit cell” which is assumed to be repeated throughout the media. The selected unit cell is the space between four cylinders with square cross section. The analytical solution leads to a closed form equation for normal permeability of porous media including the geometrical parameters. Due to lack of experimental and analytical data for fluid flow through square cross section structures, a numerical study is also done and the obtained results are compared with the analytical solution. Moreover, a suitable scale analysis approach is employed to estimate the permeability of the fibrous structure. The presented method can predict the permeability of fibrous media, especially at high porosity. The present solution is successfully compared with the existing model in the literature over a wide range of porosity.

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In this study, a single bubble behavior in dielectric viscous fluid under the uniform magnetic field has been simulated numerically by using a level set method in two-phase bubbly flow. The two-phase bubbly flow considered to be laminar and homogenous. Deformation of the bubble was considered due to buoyancy and magnetic forces induced from the external applied magnetic field. A computer code was developed to solve the problem with flow field, interface of two-phases, and the magnetic field. The Finite Volume method was applied using SIMPLE algorithm to differentiate the governing equations. Using this algorithm enables us to calculate the pressure parameter which was eliminated by previous researchers due to complexity of the two-phase flow. The Finite Difference method was used to solve the magnetic field equation. The results outlined in the present study well agree with the existing experimental data and numerical results. The results show that the magnetic field affects and controls the shape, size, velocity and location of the bubble.

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Chitosan (Cs) was extracted from shrimp shell and its derivative forms including N-alkyl (AlkCs) and nanoparticles (CsNPs) were prepared. First, the properties of nanoparticles were determined by dynamic light scattering (DLS) and the morphology of nanoparticles and N-alkylated by scanning electron microscopy (SEM). Then their antibacterial activity was evaluated by the test of minimum inhibitory (MIC) and lethal (MBC) concentration, diffusion on agar by disk, permeability of cell membrane by measurement of cytoplasmic beta-galactosidase release (ONPG). The type of apoptosis cell death was also examined by DAPI staining and changes in cell surface integrity by atomic force microscopy (AFM). The results showed that the nanoparticles are spherical with an average hydrodynamic diameter of 240 nm. N-alkyl had a rough surface structure compared to native chitosan. At the least of MIC (78 μg/ml) and MBC (100 μg/ml) points were observed for CsNPs (P < 0.05). Nanoparticles and N-alkyl of chitosan showed the highest diameter of growth inhibition zone at 1250 concentration compared to other disks (p <0.05). Outer membrane permeability of derivative forms of chitosan showed significant differences with native chitosan and cells of control. DAPI staining test showed higher cell death of chitosan-derived forms. DAPI staining test showed higher cell death of derivative of chitosan. The images obtained from AFM showed a change in the membrane integrity of the treated cells compared to spherical and clustered of control cells. Thus, the antibacterial properties of native chitosan improved by physical and chemical modification.