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The paper presents experimental data regarding organic modified silica hybrids having embedded a non-ionic dye – Disperse Red 1, deposited on cotton fabrics. Hybrids were prepared by sol-gel processes using tetraethoxysilane and various trialkoxysilanes as organic network modifying agents, in acid catalysis and in the presence of Disperse Red 1. Control of the interactions between the organic non-ionic dyestuff and its embedding matrices allows tailoring the performance of the resulted coatings. Light and wash fastness and thermo-mechanical properties of the coated fabrics were investigated and correlated to the composition and morphology of the organic-inorganic coating materials. The results show that chemical composition of the impregnating bath have a decisive role in determining shade, intensity, fastness to light or washing of the coloured hybrid coatings as well as thermo-mechanical and hydrophobic properties of the coated textile fabrics. Keywords: silica hybrids, non-ionic dye, cotton fabrics, contact angle, thermal stability

The influence of various additives, like salts, alkohols, surfactants and water-miscible organic solvents, upon the cloud point of a, w - (2-hydroxyethoxy) oligo(propylene oxide) in aqueous solutions was investigated for the first time. The results showed that NaH2PO4, NaCl, NaBr, NaI, 1-butanol, ethylene glycol and dimethylsulfoxide decreased the cloud point, while 1,2-propylene glycol, sodium dodecylsulfate, nonylphenyl ethoxylated with 9 moles of ethylene oxide and dioxane increased it. Addition of N,N-dimethylformamide practically had no influence upon the cloud point on the concentration interval investigated. The LCST of a, w - (2-hydroxyethoxy) oligo(propylene oxide) in aqueous solution was also determined and it was found equal to 19°C. Keywords: a, w-(2-hydroxyethoxy) oligo(propylene oxide), thermosensitive polymers, cloud point, low critical solution temperature (LCST), additives

This paper presents new composite materials used in extension of growth season of vegetable crops, in countries with a mild continental transition climate, for constructions type tunnel. Composite materials are realized from two components, namely textile materials with generated heat potential and polyethylene polymer foils, with a selection possibility of wave lengths in IR domain. For insurance of microclimate conditions, especially of thermal performance, the materials have been tested from electrical and mechanical point of views, following the generated heat flux and its elastic deformations for a known material width. Keywords: tunnel, horticultural crops, composite materials

Alkylation of benzene with bioethanol (95% and 100% concentration) has been done in a laboratory tubular reactor using a new modified zeolitic catalyst. The alkylation experiments have been done at different reaction temperatures , pressures and benzene/bioetanol molar ratio in order to establish their influence on the final composition of the reaction product, selectivity and conversion. The feed and products are analysed by gas chromatography. There was small differences between 100% bioethanol and 95% bioethanol aqueous solution in experimental alkylation results that it possible to use 95% bioethanol solution as alkylating agent. Keywords: alkylation benzene, bioethanol, ethylbenzene, zeolitic catalyst

Rubber is widely used for rolling stock and railway infrastructure parts. Rubber plates are used for rail – sleeper fastening systems and rubber parts are used for primary suspension of the Romanian (and abroad) electrical locomotives, of metro (underground) trains, of tramways; at tramways wheels are made as metal – rubber assembly with the purpose to minimize the unsprung mass. From above examples, it easy to see that rubber parts are used in railway field as elements which are directly involved in safety of circulation. Keywords: tests, locomotive, primary suspensions, rubber-metal

The vulnerability of ordinary Portland cement (OPC) concrete to acidic attack is a worrying subject regarding the future durability of this binder. On the other side of binder’s technology, the new technology of cement called ‘geopolymer’ had been studied widely in all over the world. Indeed, the major advantage of geopolymer compared to Portland cement is chemical resistance. This paper presents a study about the microstructural properties of geopolymer and OPC mortar. Visual inspection of both mortars had been performed. Stereo microscope device and Secondary Electron Microscope (SEM) were used to investigate the microstructural changes of the specimens. It was found that geopolymer mortars were less susceptible to the attack by sulfuric acid solution than the OPC cement mortars. Keywords: geopolymer, sulfuric acid attack, microstructural, SEM

The wide band dielectric spectroscopy analysis of the 1.5% multi walled carbon nanotube (MWNT) contain and 20% polyamide 6 (PA6) nanowebs obtained by three different treatments applied to the MWNTs (chemical, mechanical and mixed) was investigated. A morphological analysis of the samples was carried out using the scanning electron microscopy (SEM) and atomic force microscopy (AFM) principles. The evolution of the dielectric constant (Eps’), imaginary permittivity (Eps”), dissipation factor (Tan d) and the conductivity modulus were analysed, both from an experimental and a theoretical point of view. Keywords: nanowebs, polyamide 6, multi walled carbon nanotubes, wide band dielectric spectroscopy

The effects of tensile and morphological properties of styrene butadiene rubber/virgin chloroprene rubber blends (SBR/CRv) and styrene butadiene rubber/recycled chloroprene rubber blends (SBR/CRr) were investigated. The range size of CRr used in this study was 0.3 – 0.7 mm. Both SBR/CRv blends and SBR/CRr blends were prepared using two roll mill at room temperature with blend ratios 95/5, 85/15, 75/25, 65/35 and 50/50. It can be observed that, cure characteristics of SBR/CRr blends have lower cure time, t90 than SBR/CRv blends.SBR/CRr blends showed higher scorch time, t2 and minimum torque (ML) compared to SBR/CRv blends at all blend ratios compared with the SBR/CRv blends. However, maximum torque (MH) of SBR/CRr blends exhibit the opposite trend compared with the SBR/CRv blends. It can be observed that, the tensile strength and elongation at break of SBR/CRr blends show higher value than SBR/CRv blends particularly up to 15 phr of CRr in the blends. However, SBR/CRr blends shows higher value of tensile modulus (M100) than SBR/CRv blends at all blend ratios. The scanning electron microscopy (SEM) of tensile fracture surface of SBR/CRr blends at 50 blend ratios illustrated a better adhesion and dispersion in comparison with SBR/CRv blends. Keywords: chloroprene rubber, recycled chloroprene rubber, styrene butadiene rubber, tensile properties, SEM

In this paper, data on Melana-type polyacrylonitrile fibers dyeing with Methylene Blue in the presence of maleic acid copolymers with vinyl acetate or styrene are presented. Mathematical models of the studied dyeing processes have been developed and the necessary information on their significant factors are produced by means of experiment planning methods, known as Design of Experiment (DoE) or Experimental design. Optimal correlations between the application conditions and the color differences obtained on Melana fiber type have also been studied. Keywords: polyacrylonitrile fibers, dyeing, maleic acid copolymers, Methylene Blue, methods of planning experiments (DoE), color differences

Starting from the dynamic response of a sandwich beam with damping, (which is in free vibration), it is established a method used to determine the damping factor. We experimentally calculated the stiffness and damping factor per unit mass for beams with middle layer made of polypropylene honeycomb respectively; the external layers were made of epoxy resin reinforced with steel fabric. Keywords: sandwich beam, stiffness, damping factor, steel fabric, polypropylene honeycomb, free vibrations