Chemical Engineering

Measurements on efflux time are performed for draining a large open spherical tank through an exit pipe, the flow in the exit pipe is assumed to be laminar. Laminar flow is maintained by using different concentrations of glycerin solutions. The experimental values are compared with the mathematical model and found to be in good agreement with the model. The model is also verified for different exit pipe lengths and different volumes of liquid in the tank. Further, the effect of addition of polyacrylamide and polythene oxide polymers on drag reduction for water as well different concentrations of glycerin solutions is contemplated. It is observed that, for the range of concentrations of polymers considered, drag reduction prevails in absence of glycerin solutions only. The optimum concentration with polyacrylamide is found to be 1.25 ppm and in case of polythene oxide, it is 10ppm. However, for the case of polymer solutions of different concentrations prepared using glycerin solutions, instead of drag reduction, drag enhancement takes place. The trend is found to be same for all volumes of liquid as well as for all exit pipe lengths. This suggests that caution has to be exercised when using polymer solutions for drag reduction in gravity driven flow systems.

Heavy metal accumulation in waste water could affect aquatic life, human health and overall ecosystem adversely. Therefore, in recent years much emphasis has been given for the use of industrial waste water as low cost adsorbents for the removal of metallic contaminants from waste water. In this paper, the studies on removal of Cu (II) by adsorption on Limonia Acidissima hull powder as adsorbent have been investigated in a batch type experiments. The agitation time, adsorbent dosage, initial copper concentration, and the effect of solution pH are studied. Adsorption mechanism is found to follow Freundlich isotherm. The adsorption behavior is described by second order kinetics. The maximum percentage removal of copper is found to be 72.76 % for 100 ppm at pH=9 and 30⁰ C.

Biogas, a clean and renewable form of energy could very well substitute (especially in the rural sector) for conventional sources of energy (fossil fuels, oil, etc.) which are causing ecological–environmental problems and at the same time depleting at a faster rate. Despite its numerous advantages, the potential of biogas technology could not be fully harnessed or tapped as certain constraints are also associated with it. Most common among these are: the large hydraulic retention time of 30–50 days, low gas production in winter, etc. Therefore, efforts are needed to remove its various limitations so as to popularize this technology in the rural areas. Researchers have tried different techniques to enhance gas production. This paper reviews the various techniques, which could be used to enhance the gas production rate from solid substrates.

In recent years the natural supply of phenolic substances has been greatly increased due to the release of industrial byproducts into the environment. Phenol is one of the most widely used in the organic compounds in existence and is a basic structural unit for a variety of synthetic organic compounds including agricultural chemicals and pesticides. Among all the toxic compounds, phenol and its substituent phenolic compounds contribute a remarkable adverse impact to the environment. These are major xenobiotics, which are often found in the effluents discharged from the industries such as paper and pulp, textiles, gas and coke, fertilizers, The US Environmental Protection Agency (EPA, 1979) had classified the phenolic compounds as high priority pollutants due to their extensive impact on the deterioration of the water environment. In this review paper, we described about plant phenolic compounds, phenolic effects of human exposures, animal exposures, effect on children, reducing the risk of exposure and medical tests to determine concentration of phenol. Key Words: Phenol, Environment, plant phenolic compounds, Human Exposures, Animal Exposures and medical tests.

In drilling mud formulation, evaluating the mud cuttings carrying capacity provides the means of establishing its wellbore hole cleaning potential. Thus, a synthetic-based mud was formulated from derived ester and evaluated for its mud weight and rheological properties: plastic viscosity and yield point. A two level-three factors (23) full factorial design was performed to evaluate the cuttings carrying index (CCI) of the formulated synthetic-based mud. This offers the privilege of assessing the combined effect of these factors: plastic viscosity, yield point and mud weight on the cuttings carrying capacity of the mud. The factors’ levels (low and high) from the formulated mud properties measurement were 6 and 17cp, 10 and 13lb/100ft2, and 8.63 and 9.50lb/gal for plastic viscosity, yield point and mud weight respectively. Thus, the experimental design results obtained, resulted ingood cuttings carrying capacity (adequate hole cleaning) as the obtained CCI values were above 0.5. Additionally, the results further revealed main effect from the formulated mud’s rheological properties and mud weight on its cuttings carrying capacity. Furthermore, the experimental design result depicted that there was interaction effect between the rheological properties, whilst there was no interaction effect between the rheological properties and the mud weight at the considered factors’ level. Therefore, a potential synthetic-based mud with adequate wellbore hole cleaning capacity could be formulated at the considered mud properties.

Densities (?) and Viscosities (?) of binary mixtures of Benzaldehyde with Pentan-1-ol have been measured as a function of mole fraction at atmospheric pressure and at different temperatures of (303.15, 308.15and 313.15) K. Using the experimental data, excess volumes (VE) and deviations in viscosity (??) have been calculated. McAllister's three body-interaction model were used to correlate the kinematic viscosity of the systems. The excess volume data was fitted by means of the Redlich-Kister equation. It was found that in all cases the experimental data obtained fitted with the values correlated by the corresponding model very well. The molecular interactions existing between the components were also discussed.

Stone Mastic Asphalt (SMA) is a gap graded special mix consists of up to 80% by weight of coarse aggregate and 8 - 12% by weight of filler. The high proportion of coarse aggregate provides an interlocking stone-on-stone skeleton that resists permanent deformation. Since SMA contains large amount of filler, this paper presents an evaluation of the effects of filler type and particle size on the permanent deformation properties of SMA mixtures incorporating granite aggregates, 80/100 penetration grade asphalt, and four different fillers (limestone as control, ceramic waste, coal fly ash, and steel slag). The selected fraction of filler (10% by the total weight of aggregate) was blended in three different proportions 100/0, 50/50, and 0/100 passing the 75 and 20 micron. To determine permanent deformation characteristics of bituminous mixtures by repeated cyclic axial load indirect tensile testing using the Universal Testing Machine (UTM) in accordance with procedures outlined in BS-EN 12697-25:2005. The Repeated Load Axial Test (RLAT) and Resilient Modulus test were carried out on twelve different SMA mixtures using Marshall cylindrical samples to evaluate the effects of filler types and filler particle size on the SMA mixture deformation properties. The results and the analysis of the fundamental parameters of permanent deformation and resilient modulus have indicated the improved stiffness and the potential benefits in terms of high temperature rutting (increased stiffness and elastic response) of laboratory blended and proprietary of SMA mixtures incorporating ceramic waste and steel slag fillers with medium size particles (50/50 proportion) compared to the control mix. The coal fly ash mixtures are the least susceptible to permanent deformation.

The objective of this paper is to analyze the effect of variable suction and radiative heat transfer on unsteady magnetohydrodynamic free convective couette flow of a viscous incompressible electrically conducting fluid in the slip flow regime in presence of variable suction and radiative heat source. The governing equations of the flow field are solved employing perturbation technique and the expressions for the velocity, temperature, skin friction and the rate of heat transfer i.e. the heat flux in terms of Nusselts number Nu are obtained. The effects of the pertinent parameters such as magnetic parameter M, permeability parameter Kp, Grashof number for heat transfer Gr, radiation parameter F, suction parameters ?????; slip flow parameters h1, h2; Prandtl number Pr etc. on the flow field have been studied and the results are presented graphically and discussed quantitatively. The problem has some relevance in geophysical, astrophysical and cosmical studies.

The three-phase frictional pressure drop for gas-liquid-solid mixture secondary ?ow through helical curved pipe in vertical orientation is investigated and reported in this article. Effects of different operating variables on the three phase pressure drop are enunciated and the experimental results were analyzed and Lockhart-Martinelli and Davis model are incorporated to predict the three-phase frictional pressure drop. A correlation for parameter for the model is also proposed to predict frictional pressure drop for gas-liquid-solid mixture flow through helical curved pipe by dimensional analysis.

Nanostructured surfaces are surfaces bearing nano-sized features that have characteristic lengths ranging on a scale of a few to a few hundreds of nanometres. Nanostructuration of surfaces is considered as a promising track in many micro-thermo-fluidic applications, as it is expected to allow noticeable heat transfer enhancement or hydraulic resistance reductionis due to momentum transfer to the solid walls. This paper reviews and summaries the recent experimental and theoretical works on the pool boiling with nanostructure surfaces