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We started this study considering the fact that, in our surgical clinic, the association of umbilical and inguinal hernias in cirrhotic patients was found in 47,6% of cases. Although this joined pathology is quite frequent, the data comparing surgical complications and long-term recurrence when using the two mesh procedures are limited. Keywords: mesh, polipropylen, umbilical, hernia, polyvinylidene, inguinal, cirrhosis

In this paper, some aspects of electrospun nanofiber diameter measurement has been presented. The method was tested by a simulated image with known characteristics and a real web. The results show that this approach is successful in making fast, accurate automated measurements of electrospun fiber diameters. Keywords: transport properties, automated measurement, electrospinning, nanofiber diameter, image analysis

In this article we present our work on the combination of two thermostats, motivated by our research on multiscaling molecular dynamics simulations. Molecular dynamics are used for studying the properties of polymers. Two schemes - global Berendsen and stochastic dynamics - are combined. A leap-frog algorithm was used for the calculation of kthermal. Simulation results on temperature, thermal rate, and diffusion for coarse-grained (MARTINI) water are discussed. Using these thermostats we observe no deviation from the reference temperature and show that the measured thermal relaxation rates agree well with theoretical predictions. Keywords: molecular dynamics, polymers, thermostats

Manufacturing process of rubber parts have to take into consideration a set of parameters of production to accomplish the requirements of the quality standards, especially in the automotive industry. Starting from input data obtained from different rubber parts production process, this paper presents results and conclusion obtained with simulation software and specific application based on numerical methods, compared with measurements obtained in industrial process. Benefits of 3D simulations lead to important product development cycle time reduction, radical manufacturing cost reduction and possibility to optimize cycle times and product quality. Keywords: rubber injection process; Finite Element Analysis; numerical methods

The rubber is widely used at railway infrastructure and rolling stock. Rubber plates are used at rail – sleeper fastening systems, rubber elements are used for primary suspension at electrical locomotives (in Romania and abroad) and metro (subway trains) as elastic elements in buffers, or as insertion plates at streetcar wheels etc. From those examples we can see that rubber elements are used as elements which are directly involved in circulation safety. Keywords: rubber plate, rail pad, K fastening, test, railway polyethylene

The paper presents an experimental validation, through modal analysis, of some models of plates with discontinuities, made of plastic materials. The numerical study was undertaken using the Finite Element Method. The geometrical model was obtained with nondestructive evaluations using computer tomography, allowing thus to find the shape, position and dimensions of defects. The good agreement between the experimental and numerical results led to the validation of the investigated models. Key-words: defect, modal analysis, computer tomography, numerical analysis

Records of pulpal blood flow obtained from human teeth with a laser Doppler flowmeter include a very large component derived from the periodontal tissue and other tissues outside the pulp. This contamination can be reduced by isolating the tooth from the surrounding tissues. The purpose of the present study was to show that polymers and resins make possible an optimal pulp vitality testing when used for fixing the laser probe, as well as for reducing the signals originating from the periodontium. Recordings were taken from 10 healthy, intact frontal upper teeth, in 8 individuals, ages between 20 - 40 years. Signals were recorded with the laser Doppler MoorLab and a straight optical probe, MP3b. Two consecutive determinations of the pulpal blood flow at a 5 minute interval where taken for each tooth using the following methods: 1 – a silicone impression combined with light curing periodontal liquid dam, and 2 – without periodontal isolation system. The data were processed using the statistical analysis software SPSS v16.0.1. The combination of the silicon impression with the Light curing periodontal resin isolation decreased significantly statistic the flux values (68.01% decrease) and was more effective in individualizing the pulpal blood flow than simple silicone impression. The presented technique is a viable method for determining pulp vitality, reproducible, easily applicable and shows a significant reduction in the intake of nonpulpar origin signals. Key words: condensation silicones, light curing periodontal liquid dam, laser Doppler flowmetry, pulp vitality

The formation of the oxygen inhibition layer is examined on some commercial methacrylate resin based composite restorative materials: nano-filled Filtek Ultimate Universal Restorative and Filtek Supreme XT Universal Restorative and for comparison the microfilled Filtek Z250 Universal Restorative. Each material type is analyzed using scanning electron microscopy for microstructure and energy-dispersive X-ray spectroscopy for the chemical composition. Two polymerization lamps were used for various exposure times. It results an excellent chemical stability for Filtek Ultimate, while the percent of oxygen is increasing with the photo-polymerization time for the other two composites. From element mapping, the filler particles were identified and their volume percents and cluster particle size distributions were calculated. No correlation of these parameters with oxygen inhibition layer was found. Keywords: oxygen inhibition layer, chemical composition, dental restorative composites

With increasing of electromagnetic pollution and wide use of commercial and military products, there is an increasing interest in electromagnetic interference (EMI) shielding. For EMI shielding materials, typical metals have been used. Electroless copper plating of polyester fabrics was demonstrated in the present investigation and compared to sample coated by Cu-Ni-P plated after five times washing and rubbing fastness test . In order to evaluate the residual copper after applying rubbing the surface of samples, SEM images and WDX analysis have been used. The evaluation of electrical conductivity after washing and rubbing tests shows high stability in spite of detaching of some part of coating which remarkably confirms the high stability in EMI shielding effectiveness. Keywords: electroless, copper-coating, polyester fabric, washing and rubbing tests, surface resistance