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Nowadays, membrane technologies are becoming more frequently used for separation of wide varying mixtures result from a lot of industries and can compete successfully with traditional schemes. The aim of this paper was to analyse the use of ultrafiltration with polypropylene hollow fibre membrane in the chemical physical systems instead of Granular Activated Carbon (GAC) filtration. A process data collection was performed and integrated with a characterization of the process effluents in terms of treatability and reusability. In order to evaluate properly the wastewater loading, an analysis course was set. The samples have been gathered for two years; instantaneous samples were drawn from the influent and treated wastewater. Based on daily average values, a general average has obtained. The experimental data were statistically analysed and the average values of the investigated parameters. It was found that ultrafiltration is a good process solution before discharge of the effluent.

The paper describes a comparative experimental - numerical analysis to study the vibration behavior of a fiberglass/polyester composite box housing electronic components inside a satellite. A finite element model was developed in order to predict the natural modes and the values of the natural frequencies of the structure. In order to perform the numerical analyses, specimens made of the analyzed composite material were tested to obtain the elastic constants. The numerical values of the natural frequencies were further compared to those measured experimentally using a PULSE modal analysis system. The differences between results were less than 9%, validating thus the proposed numerical model, which can be further used to predict the behavior of the subassembly subjected to other loads occurring during the launching phase and on the orbit, as accelerations and/or thermal cycles. Since the order of magnitude of the first natural frequencies is important in understanding and evaluating the performance of subassemblies mounted inside satellites, such a study is necessary in the design phase of these structures.

In order to analyze the effect induced by encapsulating the drug in liposomes, comparative studies were performed for control hydrogels and complex systems (the same hydrogels containing liposomes). The results showed that the use of liposomes entrapped within chitosan hydrogels allows a strong decrease of burst effect and, moreover, the mechanism of drug release is a complex Fickian diffusion, consisting of drug diffusion through the swollen hydrogel and/or water filled pores, being continuously fed by calcein loaded in liposomes.

Engineers think twice before using plastic bearings in their designs, because they have trusted steel bearings for years or because they think plastic can’t handle demanding applications or environments. Plastic bearings can endure extreme temperatures, heavy loads and high speeds and offer more freedom when it comes to maintenance. Their resistance to dirt, dust and chemicals make plastic bearings a viable steel replacement. Plastic bearings can reduce costs up to 25%, they are highly wear resistant, with a low coefficient of friction and they can replace pricier alternatives in many applications. Plastic bearings also do not typically need lubrication unless steel balls are used in combination with plastic races and are designed to maintain a low coefficient of friction during the life of the bearing. Compared to steel bearings, which can become pitted and have a higher coefficient of friction, plastic bearings last longer. Also, plastic bearings can be used in wash-down applications, salt water and harsh chemicals without decreasing performance. Water can be considered a lubricant for plastic bearings [1].

This paper introduces some results of the researches that the authors conducted in the field of using plastic materials for plating the surfaces of the guideways for heavy duty machine tools. There are mentioned theoretical aspects about the calculation and selection of these guideways and the results of the experimental researches performed on the occasion of the remanufacturing of a rotary table intended for the machining on two axes of large mass and overall size workpieces, specific to heavy industry. It is also shown the technology of assembling and machining the plates made of plastic materials. It is about the translational sliding guideways and about the rotational guideways too. They operate with intermittent, continuous or hydrostatic lubrication. The research results can be also applied in the case of remanufacturing of other heavy duty machine tools such as: standard or vertical lathes, Gantry type milling machines, grinding machines or table type HBM-s and floor type HBM-s etc.

Clinical performance of restorative materials and their adhesive interfaces can be affected by erosion after rehabilitation of erosive lesions. The aim of the present in vitro study was to evaluate the erosive wear resistance and adhesive bond strength of direct restorative materials, using four different testing tools. Four aesthetic dental filling materials were included in the study: a universal nano-filled composite, a light curing posterior filling composite resin, a tooth-coloured polyacid modified composite resin (compomer) and a coloured compomer indicated in restorations of deciduous teeth. Fifteen specimens were prepared according to each of the four tested restorative materials. Following manufacturers’ instructions for the manipulation/mixing of the materials, adhesive systems and unset pastes were placed in cavities of 4mm length, 3mm width and 1mm depth prepared in bovine extracted teeth and cured. After 24 hours of rehydration in distilled water, each group was immersed in erosive solutions chosen for testing: 1% citric acid and 0.02% phosphoric acid. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used in order to analyze the degrees of erosive wear of the materials following exposure to the various erosive solutions. Also, microtensile bond strength (mTBS) was made and the obtained data was analyzed by one-way ANOVA test and two-sample t-test, with a level of significance that was set at p[0.05. Experimental results reveal that the dental filling materials showed different behaviour under the same erosive conditions. These findings suggest that erosive wear resistance of direct dental restoratives could influence their longevity in intraoral acidic conditions.

According to gestational age, two groups were formed: group A (abortion) formed of 19 patients diagnosed with risk of abortion (gestational age < 23 weeks and 6 days) and group B (birth) formed of 32 patients diagnosed with risk of premature birth (gestational age > 24 weeks). We were interested in detecting adverse reactions and complications related to the use of cerclage pessaries and also to determine if this procedure is efficient in preventing premature birth. In addition to the clinical part of this study, we evaluated the mechanism of interaction of the cerclage pessaries with the fluids and the vaginal mucosa by analyzing the structure, design and surface of these devices. Cerclage pessaries are efficient in preventing premature birth. In order to decrease the number and severity of the adverse reaction related to the use of these intra-vaginal devices regular follow-up visits are indicated. Re-sterilization by ethylene oxide procedure of vaginal pessaries is prohibited because it severely modifies the surface of these apparatuses.

Nowadays, scientists are making great efforts towards increasing fuel efficiency and for this, aluminium and its alloys are one of the best available options, sustainable aluminium items being able to lower greenhouse gas emissions and save energy expenses in a wide range of structural applications. Equal-channel angular pressing (ECAP) is the main severe plastic deformation (SPD) technique for obtaining ultra-fine grained (UFG) and nanostructured materials (NM), the advanced grain refinement obtained by SPD substantially enhancing microstructural and physicomechanical characteristics for the processed material, therefore arising the potential for minimizing the weight and dimensions of the items being produced. In our study, a commercial 6063 Al alloy (T1 condition) was pressed at room temperature for several passes, the ECAP processed and as-cast samples being microstructural investigated and mechanically tested. Ultimate tensile strength, yield strength, strength to fracture and maximum elongation to fracture were determined. The obtained fracture surfaces were investigated using scanning electron microscopy. For the severely deformed 6063 Al alloy, multiple correlations between the key processing parameters and the resulting microstructure and mechanical behaviour were determined. It was shown that SPD/ECAP can be used as an advanced tool in fabricating sustainable lightweight aluminium products for low environmental impact applications.

The outcome of the study is reducing the weight of a centrifugal rotor by manufacturing one out of CFRP composite. The paper presents the design study results obtained for the composite centrifugal rotor mold. CAD design of the rotor assembly and the mold were performed and one 1:2.5 scale mold for a single blade was manufactured. Mold material selection study, was performed based on critical requirements related to advanced composite processing and cure conditions. The selected mold material was epoxy Necuron material(s). The 1:1 scale 3D model mold section was designed and obtained in ABS plus using 3D printer.

The purpose of this paper is to prove that the use of synthetic meshes in the treatment of pelvic organ prolapse involves specific complications. Pelvic organ prolapse occurs as a result of the distention or rupture of a weakened, inelastic connective tissue that is a major compound of fascia and ligaments which make up the support and suspension system of pelvic organs. Pelvic organ prolapse has genetic determinism and so patients who suffer from it produce a poor quality collagen or it may happen due to premature aging. The risk for a woman to develop various stages of prolapse is appreciated to be 11% and the risk of relapse is 29.25%. Unlike in case of other surgical treated afflictions, pelvic organ prolapse has a very high risk of relapses that need surgical cure - 17%. The failure rate of the traditional surgical treatment using native tissues is 58% for the anterior pelvic compartment. Given the circumstances strengthening the weakened fascia and ligaments using biological grafts or synthetic ones proved itself necessary. The first augmentation attempts using synthetic meshes were performed by Manhes in 1990. Currently the synthetic meshes are widely used and have good outcomes, but they also have specific complications. For transvaginal interventions reconstruction using meshes is superior to the procedures that use native tissues. Surgical treatment for the pelvic floor defects consisting in synthetic mesh implant shall not be recommended unless the benefits exceed the risks for every case in particular. Based on our experimental results, scanning electron microscopy appears to be a very useful tool for surface analysis and retrieval studies of the surgical mesh used in the treatment of pelvic floor defects. Also, we find that the mesh erosion is the main adverse effect in the surgical treatment of pelvic floor defects and this appears due to the polymeric mesh materials modifications.