A new type of fuzzy n-ary hyperstructures

The aim of this paper is to consider and study a new kind of fuzzy n-ary hyperstructures, such as fuzzy n-ary hypergroups and fuzzy (m,n)-ary hyperrings.     

The characteristics of gold films deposited on ceramic substrate

A large quantity of gold (approximately 10 tonnes yearly) is consumed, all over the world, just to decorate ceramic and glassware. Due to their advanced chemical stability gold films are used for different high technology applications. The technologies for obtaining the best “liquid bright gold” were intensively studied, but the quality of the decor coatings (films) were empirically assessed. We proposed a scientific investigation of the characteristics of gold films, deposited on ceramic substrates, from “liquid bright golds”. The composition of the film has been determined by EDS (Energy Dispersive X-ray Spectrometry). The distribution of the elements was determined at the surface of the film and in cross-section. The surface distribution of the elements was uniform. The diffusion process of the film into substrate and the migration of the substrate elements at the interface region and into the film have been highlighted.     

Properties Enhancement of an Eco-Friendly Electrical Contact Material by Silver Nanoparticles Addition

Silver-tin oxide electrical contact material with 10?wt pct stannic oxide and balance nanosized and micronsized silver was developed successfully. Stannic oxide particles chemically coated by a layer of silver nanospheres are homogeneously dispersed in a silver microcrystalline matrix made by chemical synthesis. The material processed by pressing-sintering-repressing exhibited enhanced properties: density: 97.1 to 97.9?pct relative density, Vickers hardness: 103 to 115, electrical conductivity: 65 to 69?pct IACS, volumetric shrinkage: 28.9 to 30.9?pct, and a very fine and uniform microstructure.     

Antioxidative activity of 3,4-dihydroxyphenylacetic acid and caffeic acid in rat plasma

The purpose of the present paper is to study and compare in vitro the inhibitory effect of 3,4-dihydroxyphenylacetic acid (DOPAC) and caffeic acid (CA) on lipid peroxidation in rat plasma. Rat plasma was oxidized at 37°C by the radical initiators 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) or 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (MeO-AMVN). The consumption of endogenous α-tocopherol (α-TOH) and the accumulation of conjugated diene hydroperoxides were measured by high-performance liquid chromatography and by ultraviolet spectroscopy, respectively. α-TOH was consumed at the same rate in the presence of 20 mM AAPH or 2 mM MeO-AMVN. DOPAC and CA suppressed the α-TOH consumption in a dose-dependent manner. A concentration of 50 μM of both phenolic acids was sufficient to induce a lag phase and to delay the rate of α-TOH consumption. The effect was more pronounced in rat plasma oxidation by AAPH than by MeO-AMVN. CA spared vitamin E more effectively than DOPAC in both oxidations. DOPAC and CA suppressed the formation of conjugated diene hydroperoxides. DOPAC and CA at concentration 50 μM suppressed α-TOH consumption during oxidation of soybean phosphatidylcholine (2.8 mM) multilamellar vesicles containing 15 μM α-TOH, in which the lipophilic initiator 2,2′-azobis (2,4-dimethylvaleronitrile) (6 mM) was incorporated. In conclusion, we demonstrated that DOPAC and CA in micromolar concentrations have antioxidant activity in rat plasma, a medium very close to the conditions in vivo, suggesting that supplementation with the phenolic acids will provide significant antioxidant protection.     

Influence of the hydroquinone ether moieties and Bisphenol A glycerolate diacrylate on the UV stability behavior of new polyurethane materials

A series of the polyurethane materials with different ratios of hydroquinone ether derivatives and bisphenol A glycerolate diacrylate were synthesized using a two-step polymerization procedure. The structures of the obtained polyurethanes were characterized by Fourier transform infrared spectroscopy (FTIR). The influence of the hard segments structure on the thermo-mechanical properties were studied by TGA and stress-strain testing. It was found that with the increase in bisphenol A glycerolate diacrylate content, the new polyurethane materials had improved thermo-mechanical properties, due to the fact that the material develops a crosslinked structure. The durability of the polyurethane films when exposed to ultraviolet radiation was tracked by mechanical behavior and changes in chemical structure. Bisphenol A glycerolate diacrylate-based polyurethane elastomers exhibit improved behavior under UV radiation exposure compared with conventional polyurethanes that are chain-extended with butanediol.     

Influence of microfibrillated cellulose and soft biocomponent on the morphology and thermal properties of thermoplastic polyurethanes

Composite materials from thermoplastic polyurethanes (TPUs) with biodegradable segments and microfibrillated cellulose (MFC) were developed as alternatives to traditional materials used in packaging or biomedical applications. Two TPUs were synthesized by the prepolymer method starting from different soft segments, poly(ε-caprolactone)/poly(butylene adipate) (PUBA) or poly(ε-caprolactone)/poly(ethylene oxide) (PUEO), and isophorone diisocyanate/aliphatic chain extender. Proton nuclear magnetic resonance (¹H NMR) confirmed the structure and Fourier transform infrared spectroscopy (FTIR) along with scanning electron microscopy showed that the soft segments with different hydrophobicity led to a higher phase mixing in PUBA and improved microphase separation in PUEO. MFC was added in the TPUs with different soft segments to increase biocompatibility, strength, and degradation rate. A better thermal stability, a gradual increase of crystallinity and a better dispersion of MFC were noticed in PUEO composites compared to PUBA ones. The crystallinity increased with 78% and 50% in PUBA and PUEO composites with 5 wt% MFC compared to the neat polyurethanes showing the nucleating ability of MFC. In addition, the enhanced storage modulus, with 75% and 25% in PUEO and PUBA composites, highlighted the reinforcing efficiency of MFC. Therefore, the addition of MFC to the already synthesized TPUs allows tailoring the morphology and thermal properties of TPUs for industrial application.     

Physical properties and dielectric behavior of the poly(urethane-urea) based on o-dianisidine and renewable cross-linkers

The novelty of the poly(urethane-urea) series consists in inclusion of o-dianisidine units in the main chain and cross-linking with renewable biomaterials, unused compounds so far in the synthesis of the poly(urethane-urea) (Tween 20, Span 20, Phloroglucinol). The effects of these components on the structure, surface, thermo-mechanical properties and dielectric behavior of the obtained poly(urethane-urea) were investigated by Fourier transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis, static contact angles, broadband dielectric spectroscopy, and mechanical testing. The FTIR spectra showed that the urethane hydrogen bonds decreased with the increase of o-dianisidine content. Such that, at the increase of the o-dianisidine content, decreased the thermo-mechanical properties, and increased strongly the water contact angle from 83 to 108°. By dielectric relaxation spectroscopy was studied the molecular dynamics within the polymeric matrices with identical soft segments but different structure of the hard domains. These poly(urethane-urea) materials exhibit two secondary relaxations (β and γ) and a relaxation process α, corresponding to the segmental movements in the soft phase, which occurs around the temperature of −50°C independent of the measurement frequency. o-Dianisidine prevents the formation of all the urethane hydrogen bonds and so increases the chains mobility and dipoles polarization of polymer matrix, thus increasing the dielectric constants.     

PyACTS: A Python Based Interface to ACTS Tools and Parallel Scientific Applications

Many computational applications rely heavily on numerical linear algebra operations. A good number of these applications are data and computation intensive that need to run in high performance computing environments. The ACTS Collection brings robust and high-end software tools to the hands of application developers. However, this transfer of technology is not always successful due in part to the intricacy of the interfaces associated with the software tools. To alleviate this, here we present PyACTS, a set of Python based interfaces to some of the tools in the ACTS collection. We illustrate some examples of these interfaces and their performance, and evaluate not only their performance but also how user friendly they are compared to the original calls. We also present some examples of scientific applications that use PyACTS.