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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.

In this paper, we have studied the vibrations damping capacity for some composite materials that have as matrix a combination of Dammar and epoxy resin. We have used flax, cotton and silk fabrics as reinforcement materials. For comparison, half of the studied materials were made with Sandarac core. We have suggested a mathematical model for studying the vibrations of composite bars with three layers and rectangular section, based on a bar section non-linear strain. Singularizing the obtained model, there are achieved the Timoshenko equations for bars with rectangular section. For the considered bars, we have experimentally determined the damping and loss factors.

The purpose of this paper is to study the performance of composite and structures materials (laminates composites reinforced with carbon fiber and sandwich materials with laminated composite faces and foam core) by theoretical and experimental analysis on damping capacity vibration. Experiments were carried to determine the elastic and damping characteristics of composite materials on a small-scale configuration of a machine tool structure having the purpose of knowing the damping vibration ability of a column position on a Polypad structure.

Two types of sutures made by two different biopolymers were tested in terms of hydrolytic biodegradation in phosphate buffered saline solution, which simulates the physiological conditions, varying the pH of the medium and the immersion time. The determination of the degradation rate was conducted by measuring the weight loss of the sutures. The study revealed that both investigated surgical suture exhibit quite different hydrolytic degradation at various immersion times and pH level, a more intense degradation being recorded in the alkaline environment.

The dimensional stability and structural integrity of composite luting cement are key factors of clinical performance and intraoral durability. The solubility both in water and saliva of a composite luting cement is influenced by the absorption of liquid by that cement. The aim of this study is to evaluate the solubility and water sorption of three different adhesive cements (Variolink, Nexus, Dualcim) in two different environments: artificial saliva (Artisial/Biocodex, France) and distilled water at different timed intervals. Water sorption is dependent on the chemical composition of the material, the time and the immersion medium.Water sorption was different for the three cements tested, at all three time periods, both in distilled water and in artificial saliva. ANOVA test results show that for all three materials used there are statistically significant differences (p < 0.002) between the mean values for the three tested periods, both in terms of solubility and absorption. Between 7 and 14 days the water sorption continued to increase significantly for all materials tested, showing a stabilizing trend in most cases only between 14 to 21 days.

The purpose of this in vitro study was to evaluate and compare the degree of microleakage of the enamel-sealants interface when used four different materials. Analysis of the penetration of sealing materials shows that they adhere different to the enamel and the characteristics of resin composite materials used in clinical practice as sealants, influencing dental material penetration to the surface once the viscosity of the inorganic filler.

Skeleton prosthesis is defined as a complex partial movable restoration, which involves a fixed component (dental bridge cemented on the remaining prepared teeth), and movable component part. Recently, a new high performance polymer, BioHPP, based on polyether-ether-ketone (PEEK) polymer was introduced as dental material for manufacturing the framework of these types of partial dentures.The purpose of this article is to present the results of the clinical trials referring to the benefits of skeleton prostheses wearers’ patients with BioHPP framework. The research has been carried out on 48 patients. The recording of the benefits in the using this polymer for partial dentures, in accordance with seven evaluation criteria, was performed in three dental schools from Romania, during three years, at every three months.The results of survey demonstrate that BioHPP polymer frameworks for skeleton movable restorations present many benefits and advantages, therefore this PEEK type of dental material represent a beneficial new acquisition for the partial edentulous patients.

The aim of this clinical study was to investigate the comparative effectiveness of two dental desensitisers based on 2-hydroxyethyl methacrylate (Gluma desensitizer and Shield activ desensitizer), in decreasing the dentinal painful sensitivity caused by cervical erosions.The clinical trial consisted of 63 patients (323 teeth), with minimum three teeth which presented cervical erosion with dentinal hypersensitivity. The sensitive teeth were treated with Gluma Desensitizer-Heraeus Kulzer (first batch of teeth), Shield activ desensitiser (second batch) and distilled water (third batch of teeth=control group). We effectuated in total three desensitisation sessions, at 5 days difference. The level of cervical dentinal hypersensitivity (CDH) was determined in six sessions, after the patient’s response to air-blast stimuli. We used the Visual Analog Scale (VAS) to assess the CDH. The results proved the effectiveness of used desensitizing agents in treating CDH in the first and the second batch of teeth, in comparison with the control group teeth. We noticed that after the second application of Gluma and Shield products significant differences, in comparison with the baseline, appeared. After 3 month follow-up, we ascertained that both products induced the decreasing of CDH. No significant differences were recorded between the two products. A placebo effect in reduction of CDH was observed in the group of teeth treated with distilled water. Both dentin desensitizing agents have proven effective in reducing CDH.