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The increasingly wider scale use of various foreign materials in Orthopaedics and Traumatology require long-term study of their interaction with adjacent bone, with soft tissue, and also the integration of these materials into the bone tissue. One of the likely consequences of using implants and metal fasteners is the production of conductance disturbances of bone which are dependent on the type of material used, with major implications for its biology and by default on fracture healing. The purpose of this paper is to highlight the changes in focal bone fracture biopotentials depending on the chemical composition of biomaterials used. The study is experimental, on a group of 23 Wistar rats which were created femur bone defects that were repaired by autotransplantation of the hip bone with different wire set. The potential difference between the graft and the graft bed was measured and was correlated with the chemical composition of biomaterial. The largest potential differences were reported with aluminium wire, copper, and nickelin wire, while V4A wire (alloy of nickel, chromium and titanium) determined the smallest disturbance of these biopotentials. Keywords: biopotentials, aluminium, copper, V4A, bone callus

The canning of fuel elements in nuclear reactors is subjected to stress and strains, which may cause failure if the material does not possess sufficient ductility. Of particular interest is localized strain in the circumferential or transverse ductility. The ring expansion test has been used for the determination of what has been called the transverse ductility of fuel element cladding. However, after some thought, it is realized that the ductility determined in this test does not really represent the determination in a fuel pin. In this paper some results, which serve to illustrate the limits of the test to rank materials, have been discussed.

CaCO3 is the main component of the raw materials powder mixture to obtain Portland cement. In the clinkerization process, with increasing the working temperature, physico-chemical processes take place in the raw materials, the most important being the endothermal process of CaCO3 decomposition. Thermal efficiency of the plant is given by decarbonization degree of raw materials at feeding rotary kiln. It is proposed a mathematical model for correlation decarbonization degree with the main parameters (temperature, time, granulometric characteristics of the raw materials).

Acrylic adhesives show high stability towards atmospheric agents and degradation resistance. On the other hand they have low adhesion for low energy surfaces (non-polar thermoplastics: polyethylene, polypropylene etc.). Pressure sensitive adhesives based on hybrid acrylic polymers could eliminate these drawbacks by combining the performances of classical acrylic adhesive with those of elastomeric adhesives. This work is focused on the study regarding the performances of pressure sensitive adhesives based on hybrid acrylic polymers. Peel strength, shear strength and tensile strength are also determined. Keywords: acrylic adhesives, pressure sensitive adhesives, acrylic saturated rubber, hybrid pressure sensitive adhesives

In this study were investigated the thermal and mechanical behavior of some polyurethane ignites by addition with nonreactive flame-retardants. Some flame-retardants, such as the compounds containing halogen, give toxic and corrosive fumes during combustion. To prevent these problems, non-halogenated flame-retardants, such as phosphorus-containing compounds, are materials of choice. The polyurethane elastomers were prepared using dibenzyldiisocyanate (DBDI) as isocyanate, poly(ethylene-adipate)diol (PEA) as polyol, diethylehe glycol (DEG), hexanediol (HD) or 1,4-butanediol (BD) as chain extenders, and different amounts of tris(1,3-dichloro-propyl-phosphat) (TDP). In some cases, to be improved the flame resistance was used small amounts of antimony trioxide (Sb2O3), which act as a “synergistic effect”. The polyurethane ignites were characterized by thermogravimetric analysis (TGA), elemental analysis and stress-strain measurements which were performed on a TIRAtest 2161 apparatus (Germany), equipped with a 100N cell and an extension rate of 10 mm/min. The hardness measurements were effectuated on disc with an apparatus standardized in grade Shore A (oSh A).

Synthesis of orto- and para-aminobenzoic groups grafted on copolymers is described. The method is applied, extended and optimised for gel-type styrene-divinylbenzene copolymers (S-DVB) with „5` and „7` degree of crosslinking.

Some photosensitive structurally different polyamides were obtained using as starting monomers various dicarboxylic acids and 2’-(cinnamoyloxy)ethyl-3,5-diaminobenzoate. Their synthesis is based on the Yamazaki-Higashi procedure. The characterization of the prepared polyamides was accomplished by spectroscopic and thermal measurements.

Multitude of methods for the synthesis of nanoparticles express interest and importance of this field. In the present study, are addressed the aspects of obtaining nanoparticles by milling, in order to be used at nanostructured coatings in asphalt. Materials used for obtaining nanoparticles were powdery volcanic tuff with 0.4-1.6 mm grain and calcium carbonate. Stearic acid, sodium lauryl ether sulphate, a mixture of fatty acid imidazoline, a block copolymer polyethylene oxide- polipropilenoxid -polyethylene oxide and polyethylene glycol were used as additives. For grinding of inorganic particles was used a laboratory planetary mill Fritsch Pulverisette 6, equipped with a stainless steel grinding bowl. Grinding dry powdered volcanic tuff in the presence of additives influences particle size distribution. Wet milling of powdered volcanic tuff in the presence of ROT favours getting a bimodal distribution and decreasing the average particle size. Keywords: nanoparticles, grinding, additives, particle size distribution

Due to physical properties of the composite materials based on resin – textile fibres cover, in the present different utilisation areas such as: terestrial, aerian and naval transport, civil and industrial engineering, medical tehnique, food industry, sportive articles etc. This paper present ssthe determination of the water’s absorption in composites resin – flax, resin – cotton, resin – hemp.