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Polymer materials for denture bases, with thermal or light polymerization are relatively fragile, being considered brittle materials from the Fracture Mechanics concepts point of view. This paper presents a comparative study on determination of fracture toughness for 2 types of resins used in complete dentures technology: heat-curing resin (Meliodent), and light-curing resin (Eclipse). The tests were performed on a static loading machine, model Zwick/Roell of 5kN. The results obtained by 2 methods differ no more than 10-15%. Both methods showed that Eclipse has a better resistance to fracture than Meliodent. Keywords: acrylic resins, complete dentures, fracture toughness

The paper presents a study on the waste polypropylene modification with styrene-isoprene block-copolymers in correlation with elastomers molecular weight. The modification of this polyolefin improves the mechanical properties, especially the impact strength. Keywords: styrene-isoprene block-copolymers, waste polypropylene, melt blending

Solid waste disposal is a significant to overhead in a shipyard environment. In many areas of Galati the disposal capacity is being reduced and the cost of disposal is continuing to climb. The study of the behaviour of bitumen mixtures is an old subject in the literature. Many specialists have been trying to replace the sand with recycled materials resulting from blasting ship parts. The main purpose of this study is obtaining a bitumen mixture with a good behaviour to long use. The grit is an abrasive blasting material (ABM), having an angular form, used in ship repair processes prior to the application of coatings. It is produced by the pulverization of molten steel, followed by a series of thermal and mechanical treatments in order to give the product its final characteristics. The shipyard in Galati generates annually thousands of tons of used blast grit and they dispose of it in landfills or directly into the Danube as a usual practice. We intend to find possibilities of disposing the wastes produced by shipyards, our research being focused on achieving the sustainable development requirements of the civil society. Environmentally speaking, recycling spent ABM has the potential to significantly reduce waste generation while saving money. Keywords: mix asphalt, grit, recycling, shipyard

In the present study we evaluated the applicability of laser Doppler line scanning in recording the gingival healing process after a surgical procedure followed by two types of plastic provisional restoration. The laser Doppler imaging is a non-invasive method for analyzing the perfusion map of a certain area and can be used in order to establish the health status of a certain region after surgical treatment. The two types of plastic temporaries had no negative influence on the healing process. Key words: composite materials, laser Doppler imaging, microcirculation, non-invasive diagnosis, real time imaging

A biopsy sample that was taken from neurosurgery then introduced into the solution of formaldehyde was examined with Time Domain optical coherence tomography. The results are inconclusive and so that preserving was accomplished by plastination the tissue sample in which the degree of rigidity of the sample is controlled without destroying the tissue. Keywords: Plastination, Optical Coherence Tomography, nervous system

The present study pursues the influence of polyelectrolytes based on maleic co-polymers with styrene (NaM-S) and vinyl acetate (NaM-VA) under the form of natrium salt, on the colour parameters CIE L*, a*, b* of the Melana-type polyacrylonitrile fibres dyed with Crystal Violet. The colour differences are ascribed to the modifications appeared in the colour components, in terms of concentration, polyelectrolyte character and tinctorial parameters: dyeing duration and temperature. Keywords: maleic anionic polyelectrolytes, Crystal Violet, Melana - type polyacrylonitrile fibres, colour parameters CIE L*a*b*

The kinetic approach on thermal stabilization of LDPE in the presence of 7 chalcone compounds is presented. The application of zero order or first order treatment to the experimental date obtained for stabilized LDPE has revealed that the depletion of antioxidant is a first order process. The comparison of the most efficient member of chalcone series and some commercial phenolic antioxidants has provided the following sequence for the prevention of oxidation: ETANOX – 330 ] D4 ] IRGANOX – 1076 ] CYANOX – 2246 ] TOPANOL – OC ]] purified LDPE

Rheological behaviour of some products based on chemical modified starch, with characteristics proper to retarding additives for concrete designed for cementation of the big depth wells, was investigated. With that end in view, rheological tests of several pastes obtained from products of the hydroxypropylstarch type were carried out. Maintaining, at pastes preparation, the concentration of 10% additive, proved as being the most efficient in use, shearing strain tests were performed at 20°C, 40°C and 60°C versus keeping time of pastes, namely, 24 h and 48 h from preparation time. At the same time, influence of the disodicphosphate and urea additions over rheological pastes was investigated versus the same parameters. Based on the experimental results obtained, the mathematical models describing rheological behaviour of the tested additives, within a large range of external stress and temperature, were elaborated.

This paper presents data concerning the capacity of a bismaleinimide (BMI) to protect elastomers with different structures and unsaturated degree and the copolymers EVA submitted to thermooxidative destruction at 80 - 200ºC. The main structural changes were followed in the IR domain and the kinetic parameters of the processes were determined.

The research investigated the compatibility between the styrene-butadiene rubber mix and wastage materials of finite cromated leather in order to obtain products necessary in various industries or specifically in the leather and shoes industry. The researchers immersed multiple composite samples containing rubber and various proportions of leather-wastage in three solvents: benzene,carbon-tetrachloride and cloroform. The samples where then monitored during their expansion in time and the changes that occurred in the IR spectra. The studies have demonstrated the material compatibility confirmed also by mechano-physical determinations.