Development of Hydrogen-Permselective Porous Membranes Using Radiation-Induced Graft Polymerization

Hydrogen-permselective membranes were developed using a radiation-induced grafting method. Styrene (St) and acrylic acid (AAc) monomers were introduced into porous polyvinylidene fluoride (PVDF) membranes to obtain St- and AAc-grafted PVDF membranes with grafting degrees of 82% and 92%, respectively. The porosities of the grafted membranes were controlled in the range 30–40% by hot-press compression at 159 °C and 4 MPa. The hydrogen permeability was found to be of the order of 10−7 mol/m2∙s∙Pa, which was higher than the permeability for water vapor and nitrogen (oxygen model). The St- and AAc-grafted membranes exhibited 9.0 and 34 times higher permeability for H2 than for H2O and N2, respectively.

A CO2-gated anodic aluminum oxide based nanocomposite membrane for de-emulsification

A polymer-grafted through-hole anodic aluminum oxide (AAO) membrane with carbon dioxide (CO2)-responsive controlled permeability for water flux control and emulsion separation was demonstrated.

Study on the Minimum Workings System and Fuel Consumption Influence

Conservative systems are based on less intense soil loosening, carried out by different methods, without turning the furrow and only in the conditions of keeping a certain amount of vegetal residues at the soil surface; for that reasons are therefore considered to be ecological protection strategies. For this study the parcel of 118.78 ha was divided into two plots of 59.39 ha each. On the first plot (P1) the conventional soil works system was used, while on the second plot (P2) was used the system of minimum soil works. The methodology used was to analyze, synthesize and calculation of fuel consumption. Following the application of soil conservation systems, many benefits have been identified: - the time with soil tillage is reduced at 2-4 times;-the fuel consumption per unit area is reduced by 40-50%;- the number of agricultural machinery at the surface unit is reduced;-soil structure is rebuilt and surface and depth compaction is reduced;- the organic matter content from the soil is increased;- soil permeability for water is increased and global soil drainage is improved;

Influence of Aggregate Gradation and Nominal Maximum Aggregate Size on the Performance Properties of OGFC Mixtures

The effect of aggregate gradation and nominal maximum aggregate size (NMAS) on the performance properties of open-graded friction courses (OGFC) mixtures was investigated in this research. Several tests which included porosity, surface texture, indirect tensile strength (ITS), shear strength, and Cantabro abrasion loss were used to compare eight different aggregate gradations having two NMAS (9.5 mm and 12.5 mm) all from one aggregate source. For each NMAS, the gradations varied by adjusting the percent passing the No. 4 (4.75 mm) sieve. The results indicated that aggregate gradation does influence the behavior of OGFC mixtures. An increase in percent passing the No. 4 sieve showed significant decreases in porosity, which were more pronounced for the 12.5 mm NMAS compared with the 9.5 mm NMAS. Conversely, the increase in the percent passing the No. 4 sieve generally resulted in increases in the mixture performance properties as measured by the ITS, Cantabro loss, and shear strength. The results of this study provide laboratory-based evidence that adjusting the OGFC gradation by increasing the allowable percent passing the No. 4 sieve toward the higher end of the current specification range (e.g., near 30% for 12.5 mm NMAS) could potentially have positive effects on mixture durability while also maintaining adequate permeability for water drainage.

Evaluation of protective properties of acrylate varnishes used for conservation of historical metal artefacts

Acrylate varnishes are due to their suitable properties frequently used in restoration and preservation on variety of historical objects and materials. Common practice of their application involves using as an adhesive agents, consolidants and protective coatings. The purpose of protective coatings especially on metal artefacts is to reduce access of pollutants to the surface of the artefact. In this paper, coatings prepared from two acrylate polymers Paraloid B72 and Paraloid B48N are compared in terms of permeability for water and level of protective properties against air pollutants. For this purpose, electrochemical impedance spectroscopy and resistometric method were chosen for analysis of the coatings. Obtained results show lower permeability for water in case of Paraloid B72. However, same coating provided lower protection against air pollutants than Paraloid B48N coating.

Physical model of porous medium with controlled permeability based on PDMS

For filtration studies in a wide range of permeability a model of porous medium was used a porous cross-linked polymer polydimethylsiloxane. Its permeability and porosity is well-controlled in a range of 0.1–30 000 mD. In the work several samples of porous media with various permeability are presented. Obtained minimal relative permeability for water is order of 1 mD in the porous medium model.