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The article focuses on the behavior of the non-conventional treated alloyed steel in magnetic field, during the dry wear tests. It is a review of the experimental tests from last years. The thermo-magnetic treatments have been applied before the application of a thermo-chemical treatment in plasma based on diffusion process. The study was made in order to improve the mechanical properties of the alloyed steel during the friction wear. Thermo-magnetic treatment applied before the plasma nitro-carburizing treatment improves the mechanical properties of the material especially in this case, for a steel that has a considerable content of Chromium (1.02%). The behavior was studied using X-Ray diffractometry of the superficial layers during the dry friction of wear process. The wear tests used an Amsler machine, during three hours of wear tests. After each hour of the wear tests the samples have been analyzed. The diffractometric characteristics of the superficial layers obtained after a complex array of thermo-magnetic and thermo-chemical in plasma treatments, the phases distribution, the content of the superficial layers and the behavior of the steel during the wear through dry friction tests, have been considered as criteria.

The aim of this study was to evaluate and to compare the compression behavior under identical mechanical tests, of three different composite resins, by determining Young’s modulus for compression, ultimate compressive strength and ultimate compressive strain. The studied materials were: Filtek Z250 Universal Restorative, Filtek Z550 and Filtek Bulk Fill Posterior Restorative (3M ESPE, St. Paul, MN, USA). Fifteen cylindrical samples, having 6 mm in height and 5 mm in diameter, were made from each material, using plastic molds. The samples were subjected to quantitative analysis of the compression behavior after mechanical tests. The fractured fragments of the samples were subjected to qualitative surface evaluation by scanning electron microscopy. Results were statistically analyzed using one-way analysis of variance (ANOVA) with Tukey’s post hoc test. Filtek Z250 had the lowest value of Young’s modulus for compression and the results were statistically significant (p < 0.05) when compared to Filtek Bulk Fill Posterior Restorative and Filtek Z550. There were no statistically significant differences between all three materials regarding ultimate compressive strength (p > 0.05). The lowest value for ultimate compressive strain was recorded for Filtek Bulk Fill.

The AISI H21 steel used for dies in copper hot extrusion softened only after several runs. To improve production parameters a new material was necessary for the die, and, as a first choice, Inconel 718 was preferred. Prior to adopting this material for new extrusion dies an experimental program with temperature exposure cycles was performed so as to study microstructure evolution within AISI H21 and Inconel 718. The samples were studied by optic and scanning electron microscopy (SEM) and were also submitted to X-ray diffraction (XRD) and microhardness tests. The results showed carbide coalescence, which led to softening, followed by a re-precipitation in the steel, while, in Inconel 718, the precipitation (in small amounts) of delta (ä) phase was observed.Using these results and combining them with practical experience with steel, we could predict that the Inconel 718 die performance is such that at least a double quantity of copper could be extruded per die.

Due to mechanical resistance characteristics, chemical corrosion and abrasive erosion resistance, the polymers are more widely used in equipments and installations that are exploited in different fluid hydrodynamic conditions. Among these applications there is the protection of surfaces of hydromechanic organs stressed by cavitation, like in hydraulic machines rotors and valves. Consequently, the research aimes the extension of using these and protection of other components surfacess hardly streesed by cavitation. The research in this paper points toward the behavior of modified polymer layer, coated on surfaces of bronze used in casting the propellers of maritim and river ships. The tests were performed in standard piezoceramic crystal vibrating equipment within Cavitation Laboratory of Politehnica University of Timisoara. The damaging intensity of equipment is much greater than any cavitational vortex, created by ship propeller, hydraulic turbine or centrifugal pump. The obtained results, compared to both recorded on uncovered surfaces with polymer layer and recorded on surfaces covered with HVOF composite materials layers, show an increased resistance that implies the increased exploiting duration of those surfaces.

In the present paper, the authors dealt with the synthesis and characterization of a new type of dynamic membrane with polysulfone matrix and ionic polymer electrolyte: polysulfone-sulfonated polyetherether-sulfone (PSf-SPEEK). The PSf-SPEEK composite membranes were formed by ultrafiltration of SPEEK gel on the polysulfone matrix in a CELFA System installation. The thickness of the PSf porous layer for the different membranes can be between 50 and 120 mm. The variation of SPEEK active layer’s thickness is dependent both on the concentration of the SPEEK solution in the feed, and on the velocity of the surface flow. The sulfonated polymer (SPEEK) superficial layer ranges from 35 to 75 nm, being thicker at low flow rates having a slight increasing related to the increase of the SPEEK concentration. Increasing the polymer concentration, from 0.5 to 2.5%, used in the feed solution leads to a doubling of the conductivity and a tripling of the ion exchange capacity. The maximum conductivity of the PSf-SPEEK dynamic composite membranes is 0.234 S/cm and the ion exchange capacity is 1.682 meq/g.

The paper describes the advantages of material deposition using the resistive vaporization method, so that new very thin layer, which is about ìm, could be used on polymer base structure. Due to the new properties involving the friction coefficient on plane surface, where some dynamic forces are acting, we may better control the performances. By analyzing the theoretical aspects of entropy rate production, we may determine the maximum friction providing the stability of wear avoiding the material deterioration during the process.

The increasing proportion of laparoscopic interventions in the surgical centers has, also, determined an increased incidence of specific complications, such as trocar hernia. Nowadays, there is no unanimously agreed concensus regarding the optimal closure technique of the trocar incision, wether it should include the suture of the aponeurosis or not at the 10 mm ports. There is, also, no consensus regarding the proper surgical technique for the trocar hernia repair- alloplastic or tissue repair technique.The purpose of the study is to present our experience on the alloplastic repair of the trocar hernias. It is a retrospective study that analyzes the results obtained by our clinicalteam regarding the alloplastic repair of the trocar hernias, over a five-year period, between January 2011 and December 2015. The recurrence and the occurrence rates of different complications (seroma, neuroma with postoperative pain, parietal infiltration, infections and mesh rejection), depending on the type of mesh used for the surgical repair,are studied.

Natural mixtures based on bioflavonoids, terpenoids, glycosidic compounds, polyphenols, anthocyanins and essential fatty acids are often more effective and non-toxic than many synthetic drugs. Betulin, a terpene compound with many key-roles in alternative medicine, is almost insoluble in water due to its pentacyclic structure. Different drug carriers are developed to improve the drug efficacy and release. This paper described the evolution of some skin parameters (transepidermal water loss, erythema and stratum corneum hydration) after a short and respectively a long exposure to a polyurethane carrier with and without betulin using sodium lauryl sulfate as reference. It was found that these compounds are safe for human use and the hydratant effect of betulin was reconfirmed.

Postoperative eventration is a quite common condition in patients with clinical records of abdominal surgery. The purpose of this study was to investigate the efficacy of use of 2 different types of meshes (Polypropylene mesh and ProGripTM mesh-self-gripping mesh) in the surgical treatment of incisional hernias. In this respect, we conducted a study in which we introduced 128 patients operated for incisional hernias. Patients were divided into 2 lots: group A (102 patients with polypropylene mesh) and group B (26 patients with ProGripTM mesh). From the analysis of the data studied, we noticed that the average duration of surgery and hospitalization for patients with ProGripTM mesh is lower compared to patients with polypropylene mesh. Also, the rate of local postoperative complications was lower when using the ProGripTM mesh (15.38%) than in the case of polypropylene mesh. In conclusion, we can state that the use of the ProGripTM heterologous mesh is beneficial in the surgical treatment of patients with incisional hernias. The major advantage of using this type of mesh is given by a shorter hospitalization period for these patients, as well as by a lower rate of local postoperative complications in these patients.