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The ionic conductivity, ionic viscosity as intrinsic properties of PMMA - TiO2 nanocomposites were investigated. The PMMA doped with 0.4% TiO2 nanoparticles has been used for 3D printed dentures manufacturing. A structural characterization using micro-computer tomography method was performed on 3D printed dentures, which have been permanently used for 12 months. The obtained results revealed good morphological stability of the materials in vivo, in the oral environment. The reinforced polymer matrix with nanotitania particles showed a dielectric constant and conductivity dependent on frequency, exhibiting improved characteristics when compared to the pure polymer matrix.

This paper presents an experimental study on the potential use of new type of composite as insulation material. The composite material (AACW-UPR) was synthesised through mixture between the Autoclaved Aerated Concrete Waste (AACW) as filler and Unsaturated Polyester Resin (UPR) as matrix. Several samples of the composite material with different UPR concentrations (50 and 70 vol.%) and different AACW particle size (0.2-1 mm, 1.5-2.5 mm, 3-6 mm) were prepared. The thermal behaviour and the water absorption capacity of the AACW-UPR composite materials were studied. Also, the influence of water absorption capacity on thermal resistance and thermal conductivity was studied. During the investigations we noticed the following: good chemical compatibility between the AACW particles and the UPR matrix; a decrease in thermal conductivity for samples with 50 vol.% UPR and inserted particles size between 3-6 mm and an increase in water absorption capacity with the increase in the filler content in the matrix. The increasing water absorption capacity determined a decrease in thermal resistance and a reduction of the composite features as insulating material.

This paper presents and discusses research conducted with the purpose of developing the use of solar energy in the heat treatment of steels. For this, a vertical axis solar furnace called at Plataforma Solar de Almeria was adapted such as to allow control of the heating and cooling processes of samples made from 1.1730 steel. Thus temperature variation in pre-set points of the heated samples could be monitored in correlation with the working parameters: the level of solar radiation and implicitly the energy used the conditions of sample exposed to solar radiation, and the various protections and cooling mediums.The recorded data allowed establishing the types of treatments applied for certain working conditions. The distribution of hardness, as the representative feature resulting from heat treatment, was analysed on all sides of the treated samples. In correlation with the time-temperature-transformation diagram of 1.1730 steel, the measured values confirmed the possibility of using solar energy in all types of heat treatment applied to this steel. In parallel the efficiency of using solar energy was analysed in comparison to the energy obtained by burning methane gas for the heat treatment for the same set of samples. The analysis considered energy consumption, productivity and the impact on the environment. Thanks to various data obtained through developed experiences, which cover a wide range of thermic treatments applied steels 1.1730 model, we can certainly state that this can be a solid base in using solar energy in applications of thermic treatment at a high industrial level.

The interest in aesthetics of dental materials is becoming greater with time and dental ceramics have proven excellent aesthetic properties. The study investigated how does the oral environment and the different surface finishing affect the optical properties and roughness of two types of ceramic, obtained using the heat- pressed method. Results showed that immersion has some influence on the optical and roughness of the two types of ceramics, but the major influence is made by the surface finishing and the type of ceramic. Lithium disilicate ceramic proved to have better optical properties compared to feldspathic ceramic. Roughness values showed that the parameters(Ra and Rz) were influenced by the surface finishing for both type of ceramics.

The purpose of this study was: Structural characterization of two commercial nanocomposite materials (Premise ™/Kerr Corp and Tetric EvoCeram®/ Ivoclar-Vivadent); Evaluation of the marginal adaptation and adhesive interface achieved with two commercial adhesive systems (Optibond SoloPlus ™/Kerr Corp and G-Bond ™/GC). Investigation was done using electronic scanning microscopy (SEM).

Medicinal plants continue to be of real interest to researchers in interdisciplinary fields such as chemistry, pharmacy, medicine. Due to the metabolites in which it abounds, the plant material can successfully represent both a prophylactic and curative treatment. At present, countless studies, both in vitro and in vivo, are conducted to elucidate the pharmacological effects and establish the mechanisms involved. The actual experiment was purposed to evaluate the activity of raw birch bark, apple pomace and olive leaves extracts rich in triterpenes, formulated as PLGA nanoparticles, on normal/healthy different cell lines immortalized and of primary origin, such as keratinocytes, dermal fibroblasts, and gingival fibroblasts.

Given the structural resemblances between glass fiber and asbestos, it is important to understand the mechanisms through which exposure to glass fibers may affect the respiratory system. To study the effect of glass fiber on rat lung through intratracheal exposure, considering the subject’s weight variation, together with haematological parameters, C-reactive protein (CRP), total number of lymphocytes, and IL8 concentration in bronchoalveolar lavage. We performed an intratracheal instillation study on four groups of 8 randomly selected Wistar rats, by administering 3 different doses of glass fiber. The hematocrit value was an indirect indicator of chronic hypoxemia; leukocytes and the C-reactive protein assessed systemic inflammation, and total number of lymphocytes and IL8 concentration in bronchoalveolar lavage fluid determined the lung’s inflammatory response. Weight variation evaluated in all 8 measurements revealed no statistically significant changes (p=0.768). The decrease in mean blood leukocytes was interpreted in relation with the glass fiber dose, with a statistically significant difference between the study groups (p=0.003). Statistically significant differences were found in the CRP values, with dose correlations (p[0.001). The bronchoalveolar lavage fluid showed increased levels of IL-8 (p[0.05), and decrease of lymphocytes (p[0.001) in correlation with the administered glass fiber dose. The inflammatory response following exposure to glass fibers in rats is correlated with administrated glass fiber dose. The alterations described as a result of intratracheal glass fiber instillation could predict the effects which occupational exposure to glass fiber may produce in humans.

Oestrogen hormones play key roles in the human body, are involved in complex mechanisms, both beneficial and unwanted. Because semisynthetic oestrogens are commonly used today in various hormonal therapies, they has inevitably been linked to the appearance of certain carcinogenic processes, which are primarily based on oestrogen-based drugs, either as initiators or promoters. A promising alternative that can help reduce unwanted effects is to capture the active substance in a polymeric matrix that is capable of retaining its biological activity. In this study, activity on the viability of breast cancer cells with expressed oestrogen receptors of a polymeric formulation with ethinylestradiol and polylactic acid was evaluated.

This research focuses on the analysis of acacia wood reinforced PLA/PHA blend composites. Acacia wood was processed into small chip particles, which were mixed with pure PLA, pure PHA and PLA/PHA blend. The wood was treated using acetic acid and sodium bicarbonate. It was then compressed into sheet film. The micrograph shows that the PLA and PHA mixture create an interlocking continuous structure and the addition of wood strengthens interlocking between PLA and PHA. Mixtures of this blend also reduce bubble and crack, and create new properties superior than the earlier properties of existing PHA and PLA.

This work deals with the problem of developing vibration damping polymeric materials which are effective at low temperatures (from minus 40 to 0°C). Due to the fact that the vibration damping efficiency in the composite is mainly determined by the properties of the polymer matrix, it is necessary to study its properties depending on the type and amount of structure-forming parameters. The purpose of the work is to determine the changes in the dynamic properties of the polymer composition based on butyl rubber, EPDM, ethylene-vinyl acetate copolymer (EVA) filled with increasing amount of calcium carbonate. The leading methods of studying this problem were the method of scanning electron microscopy and the method of dynamic mechanical analysis. It has been stated that the selected polymers can be considered as competent candidates for damping materials at low temperatures, and the calcium carbonate filler allows more fully to realize the vibration damping properties of the polymer. The obtained dependences can be used as initial data for analytical predicting of damping properties of polymer composites.