Sulfur composite technology from oil refinery waste

© Research India Publications.Oil and gas waste is a valuable material for chemical industry and new material intensive alternative. The article studies a possibility of obtaining inorganic sulfides from elemental sulfur and an active silica containing material with better mechanical and physical properties and analyses their formation. The usage of an aluminum chloride activator allows activating sulfur and silica components of materials that contributes to obtain unyielding and long-lasting sulfur composites having better performance properties. To understand the chemical processes developing in the system and prove new chemical bond formation, the quantum-chemical research using software products is undertaken. The comparative thermodynamic assessment of insertion and replacement reactions in triple and singlet state of sulfur is carried out. The impact of silicagel premodification with aluminum chloride on reaction with sulfur and calcium sulphide formation is defined. The quantum-chemical calculation results confirm the chemical reaction possibility between sulfur and silicagel modified with aluminum chloride. According to the research results, the schemes of obtaining silica containing materials from opal cristobalite rock of various deposits are suggested. According to the research results, we can offer the manufacture technology of inorganic sulfides and sulfur composites employing an activator-aluminum chloride. A key technology scheme of sulfur composite manufacturing from inorganic sulfides is developed. The acquired data on usage of interaction mechanisms of sulfur with various inorganic compounds can provide background for developing recycling technologies of sulfur obtained in the process of oil refining into sulfides and multipurpose materials

Development of the recommendations on selection of glass-fiber reinforced polyurethanes for vehicle parts

© Research India Publications. Advanced polymer composites have essential features: high specific strength ratio, resistance to aggressive substances (water, fuel, oil, lubricants, weak alkalies and acids), wide operation temperature range (from -60 to +80 °C), sufficient durability (up to 10 years), high aesthetic qualities. The use of polymer composites for vehicle parts significantly reduces the curb weight of a vehicle, improves its dynamic behavior, increases its payload capacity, reduces its fuel consumption and emissions. The research was focused on the parts made of rigid glass-fiber reinforced polyurethane. The samples were made using the system based on polyol component А and isocyanate component B in a ratio of 1,75:1 (A:B). As a filler the glass fiber roving was used in the amount of 25 weight parts per 100 weight parts of the matrix component. The glass-fiber reinforced polyurethane parts were manufactured by spraying. The paper describes the comprehensive research of the glass-fiber reinforced polyurethane properties including the evaluation of thermal resistance, impact resilience, temperature resistance, Shore D hardness, acoustic absorption coefficient with the state-of-the-art test procedures and research equipment. The recommendations were developed to select glass-fiber reinforced polyurethanes for vehicle parts: for parts where the material is under high load during operation (temperature, impact resilience, etc.) it is recommended, whenever possible, to use the materials with larger thickness; for the parts where hardness is subject to special requirements – the materials with smaller thickness; during part production it is necessary to precisely carry out the operations of part manufacturing process to avoid any defects which are stress raisers and reduce the material strength

Teores de minerais em polpas e cascas de frutos de cultivares de bananeira

The objective of this work was to determine the dry matter percentage, the mineral content, and the ability to supply minerals, based on dietary reference intake in the pulp and peel of unripe and ripe fruits of 15 banana cultivars. Four bunches were used per cultivar, and six fruits per sample unit. Fresh pulp and peel samples were collected for sulfuric (0.2 g) and nitric perchloric (0.5 g) digestions. The following were determined: in the sulfuric extract, total N by the Kjeldahl method; and, in the nitro perchloric extract, P, K, Ca, Mg, Cu, Mn, Fe, Zn, and Se. P was determined by colorimetry, and the other nutrients by atomic absorption spectrophotometry. The mineral content in the pulp and peel was expressed based on the average of the two stages. There are differences between banana cultivars regarding the concentration of macro‑ and micronutrients in the pulp and peel, but not between unripe and ripe fruits. The Terrinha cultivar showed the highest percentage of dry matter in the pulp, and the Marmelo and Maçã cultivars in the peel. For N, P, Fe, Zn, and Cu, the peel showed twice the content of the pulp. The content of K and Mn in the peel was approximately four times that of the pulp. The pulp of the Caipira (AAA) cultivar, and the peel of the Prata and Pacovan (AAB) cultivars show the highest mineral contents.O objetivo deste trabalho foi determinar a percentagem de matéria seca, o teor de minerais e a capacidade de fornecimento de minerais, com base na ingestão dietética de referência na polpa e na casca de frutos verdes e maduros de 15 cultivares de bananeira. Utilizaram-se quatro cachos por cultivar e seis frutos por unidade amostral. Foram coletadas amostras frescas da polpa e da casca, para digestões sulfúricas (0,2 g) e nitroperclóricas (0,5 g). Foram determinados: no extrato sulfúrico, o N total pelo método Kjeldahl; e, no extrato nitroperclórico, P, K, Ca, Mg, Cu, Mn, Fe, Zn e Se. O P foi determinado por colorimetria, e os demais nutrientes, por espectrofotometria de absorção atômica. O teor de minerais na polpa e na casca foi expresso com base na média dos dois estádios. Há diferenças entre cultivares de bananeira quanto à concentração de macro e micronutrientes na polpa e na casca, mas não entre frutos verdes e maduros. A cultivar Terrinha apresentou a maior percentagem de matéria seca na polpa, e as cultivares Marmelo e Maçã, na casca. Para N, P, Fe, Zn e Cu, a casca apresentou duas vezes o teor da polpa. O teor de K e Mn na casca foi de aproximadamente quatro vezes o da polpa. A polpa da cultivar Caipira (AAA) e a casca das cultivares Prata e Pacovan (AAB) apresentam os maiores teores de minerais

The influence of temperature differences for the analysis of thin orthotropic cylindrical shell

A problem of elasticity of cylindrical shell made of orthotropic different resistant material is considered in this article. The problem is uncoupled, i.e. it consists of two separate problems: of structural mechanics and of thermodynamics. The article contains research of a shell within the framework of shallow shells theory. The solution is based on the technical hypotheses of Kirch-hof–Love. The relations of Treschev are used in the capacity of physical dependencies. The main relations are used in the form of the elastic solutions method of Ilushin. The process of heat transfer is described by classic equation of heat conductivity. The article introduces a system of solving equations in combined form supplemented by initial conditions and boundary conditions. The object of the problem is a shell that suffers evenly distributed load placed perpendicularly to the inner surface of the shell as well as thermal action in the form of temperature differentiation on the inner and outer surfaces of the shell. The shell is being examined in the particular moment of time when the temperature transfer has subsided. The article contains the solution of the specific problem of thermo-elastic bending of thin circular cylindrical shell made of three-reinforced woven polymer. Some specific results of stress––strain state analysis are shown: deflections of the shell, axial and circular stresses, followed by the comparison of the results with and without consideration of thermal action, as well as analysis of influence of thermal action on the stress–strain state of the shell

Production and investigation of properties of sulfide composite materials based on technogenic sulfur waste with titanium chloride as an activator

The modification with titanium chloride contributes to the increase in active sites of silica-containing compounds and opening of sulfur rings. As an activator, titanium chloride helps to make resistant and durable high-performance sulfur composite materials

Investigation of non-metallic materials for noise shields used in trucks

Low noise level in the cabin is the important feature of a modern truck. Lower noise level is achieved with modern soundproofing and absorbing materials. These materials must be resistant to corrosive media and high temperature, have low specific weight and be easily processable and safe for humans. The protective truck covers made from modern composite materials ensure the high sound absorption

Study of effects of redispersable latex powders on hardening kinetics of cement-sand composites

Redispersable polymer powders act as boosters of the physical and mechanical properties in the cement-sand composite. For the studies the most typical redispersable polymer powders were used - Rhoximat PAV 22 and Rhoximat PAV 23 latex powders, by Rhodia. The analysis of the micrographs showed that the new formations of the cement rock had a pronounced needle-like form, and the cements with the additives were partially covered with the polymer film of the redispersable particles. The resulting polymer bridges and cords in the structure prevented growth of the cracks which were formed due to shrinkage and applied external force. Film-forming latex of redispersable powder can increase fracture energy of the cement-sand composite significantly. In view of this, of great significance is strength of the polymer itself. The higher strength polymer has, the greater force one should apply to fracture modified mixture. The basic components of Rhoximat PAV 22 and Rhoximat PAV 23 are vinyl acetate and vinyl versatate. Vinyl resins in the cement composites are known to develop a lattice which penetrates the structure formed by the cement gel, and, thus, act as an additional binder in the material

The influence of temperature differences for the analysis of thin orthotropic cylindrical shell

A problem of elasticity of cylindrical shell made of orthotropic different resistant material is considered in this article. The problem is uncoupled, i.e. it consists of two separate problems: of structural mechanics and of thermodynamics. The article contains research of a shell within the framework of shallow shells theory. The solution is based on the technical hypotheses of Kirchhoff-Love. The relations of Treschev A.A. are used in the capacity of physical dependencies. The main relations are used in the form of the elastic solutions method of Ilushin A.A. The process of heat transfer is described by classic equation of heat conductivity. The article introduces a system of solving equations in combined form supplemented by initial conditions and boundary conditions

The influence of mineral fillers on mechanical properties of polyvinyl chloride composites

The paper reports the investigation results of tensile stress-strain properties of filled PVC composite during static and low cycle testing. The distinctive features of composite mechanical behavior depending on the content of dispersed mineral fillers which are basically industrial waste are established. It is revealed that small filler additives have a strong influence on the structural behavior that manifest itself as their abnormal change depending on the filler content. The experimental data obtained are explained based on the modern ideas about structural morphological model of base polymer structure. © IDOSI Publications, 2013

Constitutive relations for isotropic materials allowing quasi-linear approximation of the deformation law

© 2019 Published under licence by IOP Publishing Ltd. Variants of deformation potentials for isotropic materials that do not obey the "single curve" hypothesis are considered. The advantage of the potentials formulated in two normalized stress spaces in comparison with other variants of quasi-linear models of the constitutive relations for isotropic materials is demonstrated. It is shown that the claims of some authors on the originality and universality of the deformation potentials proposed by them are not justified, and their variants of relations are reduced to two forms of writing in normalized spaces