Recent Trends in Chemical and Material Sciences Vol. 2

At temperatures of 303K, 308K, and 313K, the Density (\(\rho\)), viscosity (\(\eta\)) and ultrasonic velocity (U) of chlorpheniramine with 1-ethanol solutions were measured. Various physicochemical parameters, such as adiabatic compressibility (\(\beta\)), free length (L_f), free volume (V_f), viscous relaxation time (\(\tau\)) and Gibbs free energy (\(\triangle\)G) can be obtained via systematic measurements.  The objective of the present study is to analyse the intermolecular interaction between the selected liquid system. Further, determine the changes in the interactions with the various temperatures. From the deviations of the excess values,analyse the type of interactions between the amine group present in the chlorpheniramine and the hydroxyl group of the 1-ethanol in the liquid mixtures.The intermolecular interactions are used to calculate and reveal the deviations of such quantities from their ideal values.To validate the calculations, the standard deviations and coefficients of Redlich Kister polynomials of excess quantities are calculated. These findings indicate the existence of intermolecular interactions and their strength with temperatures of 303K>308K>313 K.

The rubber material properties and useful lifetime evaluation are very important in design procedures to ensure the safety and reliability of rubber components. This study examined experimentally the characteristics and useful lifetime prediction of rubber components for an elevator cabin. Material tests and accelerated heat-aging tests were conducted. The rubber material coefficient was obtained by curve fitting of uni-axial tension, pure shear and equi-biaxial tension test data. To assess and predict the useful lifetime of natural rubber component, the changes in mechanical properties were determined under accelerated aging conditions. The rubber was aged at temperatures ranging from 70ºC to 100ºC for between 1 and 60 days. This paper presents a general approach for correlating the accelerated aging results with aging under service conditions using an Arrhenius methodology. Several useful lifetime prediction equations for the rubber component were proposed using the rubber material and component test. The predicted useful lifetime of the rubber component for an elevator cabin agreed fairly well with the experimentally determined values.

Hydroxyapatite (HA) is a naturally occurring important osteo dental mineral in humans. Synthesis of the biomineral of hydroxyapatite in the nano scale as a versatile ceramic having an adhesive property, as a tissue transplant, dental implant is an ongoing research. The research reports have mainly focused on enhancing various properties of hydroxyapatite by making as nanocomposities for multifunctional applications. There is a need for making use of biowastes, (animal or sea wastes) that can be the potential precursors with abundant minerals for the fabrication of HA. The research study focusses on the conversion the seawaste/ seashell (Crassostrea virginica seashell) into hydroxyapatite followed by further modification with neem (Azadirachta indica) extract for enhanced anti-microbial activity. The study provided a road map in two aspects one being, locating the rich natural resources (sea) in the country and another being efficient tapping of such resources as the precursors for the fabrication of biomedicated materials. The highlight of the study is the comparison of the assynthesized material (from the green source) with the sample synthesized from a purely synthetic resource. The comparison in terms of microstructure, morphology, anti-microbial activity provided many cues to synthesis- structure- activity relationship of HA. The effective change in surface morphology and the ratio of Ca to P (Ca/P) of HAp is an important step towards tooth and bone replacement upon modification The benefit of addition of further antioxidant natural extracts to HA depends on the condition of in situ or post preparation of HA. The screening of antimicrobial properties (Streptococcus mutans bacteria and Candida albicans fungi) of the synthesized HAps gave satisfactory results. Ultimately the research study contributes towards the efficient design of multifunctionality to the bio mineral of HA. It will benefit the field of dentistry and orthopedics.

The goal of the current program is to develop geopolymer fly ash building bricks that cure in the atmosphere. Fly ash and an alkaline soda-based chemical activator solution are used to make geopolymer construction bricks in the presence of sodium silicate and water, with a different Na₂O/(Al₂O₃+SiO₂) ratio maintained. Under atmospheric curing, 230 mm x 110 mm x 75 mm fly ash building bricks are formed. After 25 days of atmospheric curing the results shows that the geopolymer fly ash building bricks attain a crushing strength of 10 to 12 Mpa.

The purpose of the work is to develop recommendations for ensuring the quality of paints and varnishes for building products and structures. Information is provided on the application of statistical methods for managing the quality of products when painting building products and structures. It is shown, that the quality of the finish depends on the method of applying the paint, the porosity of the cement substrate. The problem of safety of paint and varnish coating properties during storage and operation is significant and relevant. For coatings based on all types of paints the minimum roughness value of the coating surface and the minimum value of the risk are typical in the case of applying paints to the putty surface, regardless of the method of application. Offered to organizations, firms, engaged in the execution of finishing works, the introduction of the kaizen approach to the renewal of staining technology, based on continuous improvement of activities and providing for the use of statistical methods for managing the quality of products. Information on the effect on the longevity of coatings of the quality of their appearance is given. It is shown, that coatings with a high roughness index are characterized by low durability during exploitation. A model of the cohesive strength of coatings is presented, depending on the surface roughness.

Development of technological processes in chemical and metallurgy industry is a significant increased in research chemical systems with a view their practical application. The article provides results of experiments on research of speed of escalating of vanadium gel on short-circuited probes from various metals, particularly from copper and aluminium it is shown that speed of escalating of gel on probes is influenced with a material of a probe and configuration of probes in a solution. Research of growth of vanadic gel on metal probes from various metals allows to draw a conclusion on the electrochemical nature of this process. Formation of vanadic mesogels can be considered as macroscopically manifestation of processes of self-organizing which spontaneously proceed in a solution.

Researchers at the top crude oil companies are working at various eligible options like biodiesel, hydrogen, alcohols, compressed natural gas (CNG), liquefied petroleum gas (LPG). The main purpose of this article is to obtain differences in engine (Doosan MDT196TI) vibrations which was powered using two different fuel mixtures – liquefied natural gas with diesel pilot and diesel only. LNG and diesel oil differ in combustion temperature, density, and cetane numer; the combustion process of various fuels proceeds differently, so it has an impact on the generated vibroacoustic vibrations (vibrations have a direct impact on the degree of machine degradation). In research, diagnostic system is based on pizoelectric accelerometers and Digital Signal Processing operations (windowing, Fast Fourier Transform). In conclusions were used to analyze the results obtained, indicating how the tested fuels have an effect on vibrations

By employing sulfuric acid as a dopant and APS as an oxidant, polyaniline Emeraldine salt (ES) and its composites with metal oxides V₂O₅, ZnO, and MgO were produced using a chemical oxidation approach by combining various mass percents of metal oxides with monomer in a polymerization mixture. SEM analysis was used to examine the morphological nano form and nano size of these composites.

Treated urban wastewater fish are used in fish farming in some countries around the world. However, it can be dangerous to fish and people consuming it due to toxic chemicals and microbial pollution. In this study, the effects of heavy metals (Ag, Al, As and B) on the nervous system, skeletal and skin tissues of fish, and the accumulation in these tissues of fish fed in a wastewater treatment plant with secondary treatment are explained as an example. Ag, Al, As and B in treated effluent and skeleton, skin, eyes and brain tissues of Carassius gibelio species were investigated seasonally. According to annual averages the size order of Ag and B concentrations were skeleton> skin> eyes>brain and skeleton> skin>brain>eye respectively. Also, skin>brain>eyes>skeleton was for As and Al.   TF (Transfer Factor) values of all metals examined were determined as >1 in the four tissues and the metals caused bioaccumulation because of treated effluent. The size order of TF and BCF (Bio-concentration Factor) values in skin and eye tissue were the same and it was Ag>Al>As>B. It was Ag>Al>As>B in skeleton, Al>As>Ag>B in brain. HQ (Hazard Quotient) of Al in all tissues had carcinogenic risk level.

Thiazines are very useful units in the fields of medicinal and pharmaceutical chemistry and have been reported to exhibit a variety of biological activities. This has directed us to synthesize chloro-substituted thiazines from 2'-hydroxy-3',5'-dichloro-4-4'-chlorophenyl chalcone with thiourea, phenyl thiourea and diphenyl thiourea. In this series, we have synthesized 4-(2'-hydroxy-3',5'-dichlorophenyl)-6- (4'-chlorophenyl)-2-imino-1,3-thiazine and 4-(2'-hydroxy-3',5'-dichlorophenyl)-6-(4'-chlorophenyl)-2-iminophenyl-1,3-thiazine from thiourea and phenyl thiourea respectively and 4-(2'-hydroxy-3',5'-dichlorophenyl)-6-(4'-chlorophenyl)-2-iminophenyl-3-phenyl-1,3- thiazine from diphenyl thiourea. The newly synthesized chloro-substituted 1,3-thiazines were screened for their antibacterial activities against Gram positive pathogens Staphylococcus aureus and Streptococcus sp. and Gram negative pathogens Pseudomonas sp. and Salmonella typhi. All these compounds have been characterized on the basis of their UV, IR and NMR spectral studies.

The aim of present work is to develop a mixed ion-electron conductor for application as electrode material in electrochemical devices. With this perspective in mind an attempt has been made to prepare and characterize PVA:PVK:CH₃COONH₄:EC system. XRD, Optical Microscopy, SEM and IR studies assured the formation of polymer blend and composite electrolyte system during structural investigations. Electrochemical measurements reveal improvement in electrochemical window upon addition of ammonium acetate. Ionic charge transport seems to dominate as reflected from I-t measurements. Ionic conductivity of this system is seen to improve by an order of magnitude at room temperature with optimum conductivity (1.27×10^-3 S/cm) for 0.4 mole ammonium acetate concentration. Temperature dependent bulk conductivity follows a combination of Arrhenius and VTF behavior. Jonscher Power law seems to be obeyed during a.c. conductivity experiments.  

Nanophosphors in the amorphous state were produced for the first time by pulsed electron beam evaporation of micrometer-sized polycrystalline phosphors of the composition Ca₂Y₈(SiO₄)₆O₂: Eu. It was found that the Raman spectrum is modified and the forbidden band width of the samples increases when the particle size lowers from micro- to nanodimensional state. The spectral luminescent characteristics in polycrystalline and amorphous states have been examined. It was established that during the transition to nanoamorphous state the phosphors change their photoluminescence color from red-orange (Eu³⁺) to blue (Eu²⁺).  

In the presented paper, a linear rule between the osmotic coefficients on mole fraction base and each of several concentration expressions is presented, respectively, in the single electrolyte solutions which include various valence, such as uniuni-, biuni-, triuni-, tetrauni-, bibi-, and tribi-valence inorganic acids, alkalies and salts. Based on the rule, a thermodynamic model is developed and successfully applied to these electrolyte solutions to predict and reproduce their conventional osmotic coefficients, and other properties, like the relative molal vapor pressure lowering, the equivalent conductivity, solubility, even the association effects of ions. The examples with satisfied results have been given.

Kenaf fibre is one of the product obtained from the kenaf plant and is abundant in many parts of the world. Research work carried out on the use of kenaf fibre to strengthen cement mortars as a building material showed good results. Cement mortar mixes were proportioned to incorporate fibre volume of between 1-3% and 10-30mm fibre length. Performance of the composite are evaluated with respect to the density, water absorption and compressive strength. From the results obtained, water absorption increased with fibre volume but still fell within the limits set by ASTM C 211-77. There was no significant effect on the density of the kenaf fibre cement mortar. The analysis of variance (ANOVA) at 5% level of significance showed that there is no statistical difference between the means of the compressive strength of plain mortar and those containing 1-3% fibre volume at 10mm fibre length. Regression models fitted on the compressive strength data showed a strong relationship between fibre volume, fibre length, and curing age.

Being the most abundant and least expensive of the noble and precious metals, such as copper (Cu) island on silver (Ag) with excellent electrical and thermal conductivity, copper is used extensively in electrical power transmission, plumbing, cookware, etc. The important properties of silver include its good electrical conductivity and its chemical stability. Bulk Ag is a common material for high-quality reflectors of electromagnetic radiation in the visible regime, superseding cheaper non-noble metals such as aluminum. At three different temperatures 300, 500 and 700 K the diffusion is carried out. The lattice parameter has been calculated for Ag and compared with the experimental values. It is found that by increasing in temperature the rate of diffusion also increases. The diffusion prefactor is 5.24 × 10¹¹ Ų/s. So far the experimental and theoretical work for other islands shows that the effective energy barrier and diffusion coefficient have Arrhenius plot gives the effective energy barrier value of 143.56 meV and diffusion prefactor value of 5.24 × 10¹¹ Ų/s for 10-atom island. The values of diffusion coefficient and effective energy barrier are in the same range as for the other islands regarding the theoretical and experimental work done so far. At 300 K, the fissures and dislocations have been observed near the island. However, these conclusions are in agreement with the recent findings using ab-initio electron structure calculation.