Buoyancy and thermal radiation effects for the Blasius and Sakiadis flows with a convective surface boundary condition

This study is devoted to investigate the Buoyancy and thermal radiation effects on the laminar boundary layer about a flat-plate in a uniform stream of fluid (Blasius flow), and about a moving plate in a quiescent ambient fluid (Sakiadis flow) both under a convective surface boundary condition. Using a similarity variable, the governing nonlinear partial differential equations have been transformed into a set of coupled nonlinear ordinary differential equations, which are solved numerically by using shooting technique along side with the sixth order of Runge-Kutta integration scheme and the variations of dimensionless surface temperature and fluid-solid interface characteristics for different values of Prandtl number Pr, radiation parameter NR, parameter a and the local Grashof number Grx, which characterizes our convection processes are graphed and tabulated. Quite different and interesting behaviours were encountered for Blasius flow compared with a Sakiadis flow. A comparison with previously published results on special cases of the problem shows excellent agreement

Effective Gravimetric Characterization for Lignocellulosic Biomass: Comparison of NaOH-H2O2 and Ca(OH)2-H2O2 Oxidation Pretreated Sugarcane Bagasse

In this study, alkaline peroxide oxidation pretreatment was evaluated for sugarcane bagasse, a lignocellulosic biomass. By comparing the effects of NaOHH2O2 and Ca(OH)2 on pretreatments at specified reaction time periods (3, 6, 9, and 12 h) and reaction temperatures (60, 70, 80, and 90 h), optimum responses in term of cellulose content, hemicellulose solubilization, and lignin removal were established. Optimum pretreatment conditions of 80 oC reaction temperature, 3 h reaction time, and 30 mL/L of water hydrogen peroxide concentration (1%H2O2) solubilized 69.5%(w/w) hemicellulose for the sodium hydroxide peroxide (SHP) pretreatments, 75.8%(w/w) lignin removal was also achieved with 59.2%(w/w) cellulose retained in the solid fraction. In addition, the responses for the optimum conditions for the calcium hydroxide peroxide (CHP) pretreatments, the cellulose content, hemicellulose solubilization, and lignin removal were 50.3%, 66.6%, and 65.4%(w/w) respectively. Pretreatments showed both NaOHH2O2 and Ca(OH)2-H2O2 to be useful pretreatment agents for the disruption of the polysaccharide complex. The study also revealed that NaOH-H2O2 pretreatment stands as a better choice to Ca(OH)2-H2O2 pretreatment

The production of Wara cheese from locally sourced coagulants and its nutritional evaluation

The use of vegetable extracts as milk coagulants has evolved recently in soft cheese processing. In this study, two types of cheeses were produced from locally sourced raw cow milk using two different coagulants, Calotropis procera leaf and CaCl2. Protein, fat, Zn, Mg, and Fe were the nutrients and minerals that were assayed. The protein (18.4%), Fat (7.93%), Mg (4.13%), Zn (4.01%), Fe (2.59%) of Calotropis procera coagulated cheese was significantly higher than CaCl2 coagulant produced cheese with protein content of (9.13%), Fat (5.53%), Mg (2.34%), Zn (2.59%), Fe (1.13%). The higher ash content in the cheese produced with CaCl2 coagulant makes it susceptible to microbial growth, as a result, reducing its shelf-life. The study suggests that cow milk and Calotropis procera produced cheese appears promising in nutritional contents with further quality improvemen

Enhanced Biodegradation of Hydrocarbon Sludge Using Consortium of Microorganisms

In this work, the effects of consortium of Microorganisms, Pseudomonas purida, Pseudomonas aeuniguma, Pseudomonas florescence, and Bacillus megaterium, in degrading hydrocarbon sludge from refinery wastes, in Niger Delta area of Nigeria, have been studied. Focus is particularly on reduction of BOD, COD, TOC and ROC of the hydrocarbon sludge to comply with standard requirement for disposal. The organisms were maintained in nutrient agar plants and subculture on weekly basis throughout the period of investigation. Lab-assay method was used to carry out the experiment, i.e, Ex-Situ treatment. The sludge was inoculated with the consortium of Microorganisms and samples were taken for analysis at two week interval for a period of eight weeks. Result shows that, for the duration of investigation, there was 71.3% reduction of the initial BOD, 60.0% reduction of the initial COD, 78.4% reduction of the initial TOC and 78.1 % reduction of the initial ROC. It was noted that given enough time the consortium of Microorganisms has the potential to biodegrade the hydrocarbon sludge to an acceptable level of the Environmental Regulatory Body's standard. The sludge however requires more than eight weeks for the toxic level to be reduced to Regulatory Body's standard. It was also observed that the rate of biodegradation of the sludge by the Microorganisms declined with time

Effects of Ohmic Heating,Radiation and Viscous Dissipation on Steady MHD Flow Near a Stagnation Point on an Isothermal Stretching Sheet in the Presence of Heat Generation

Aim of the paper is to examine the influences of radiation, heat generation, Ohmic heating and viscous dissipation on steady flow of a viscous incompressible electrically conducting fluid in the presence of uniform transverse magnetic field and variable free stream near a stagnation point on a stretching non-conducting isolhennal sheet. The governing equations of continuity, momentum, and energy are transformed into ordinary differential equations and solved numerically by shooting method alongside with Runge-Kutta sixth order. The velocity and temperature profiles are extensively discussed numerically and presented with the aid of graphs. Skin-friction coefficient and the Nusselt number at the sheet are derived, discussed and their numerical values for various values of physical parameters are COf11lared with the existing literature in tabular form and there are perfect agreements

Distillery Wastewater Decontamination by the Fenton Advanced Oxidation Method

This study evaluated the effect of Fenton advanced oxidation process on the treatment of an industrial wastewater (distillery). The comparison of the effects of Fe2+ loadings, H2O2 dosages (2%(v/v)and 4%(v/v)), reaction temperature and reaction time, established optimum efficiency in terms of BOD and COD reductions. The best operating conditions for the treatment of the distillery wastewater containing 43.85 mg/L BOD concentration and 274.28 mg/L COD concentration in the raw effluent was 2% H2O2 dosage at constant loadings of Fe2+ (1.5 g), 80 oC pretreatment temperature, and 1 h reaction time. At this optimized condition, the BOD content reduced to about 35 mg/L (about 21% removal) and COD content reduced to about 53 mg/L (about 81% removal). There was a complete removal of the initial colour present in the wastewater after the treatment process. The process proved the ability to effectively reduce the COD content which when high in industrial wastewaters can lead to serious impacts to the environmen

Optimum Hydrolysis Conditions of Cassava Starch for Glucose Production

Acid and enzymatic hydrolysis of cassava starch to glucose (fermentable sugar) were investigated and compared. And the effects of acid concentration, pH, temperature and time on the yield of glucose were studied. Experiments were carried out at a temperature range of (60 – 100)0C between 30 minutes and 4 hours. (0.2 – 1.0)M strength of H2SO4 acid was used and pH values range of 4 – 7 was considered during enzymatic hydrolysis. The study revealed that maximum concentration of glucose was obtained at 1000C using 1.0M H2SO4 acid for 4 hours during acid hydrolysis. At pH of 4, temperature of 600C and 4 hours of operation, highest concentration of glucose was obtained during enzymatic hydrolysis. Enzymatic hydrolysis produced higher yield of glucose when compared to that obtained from acid hydrolysis

A Comparative study on Glucose Production from Sorghum Bicolor and Manihot Esculenta Species in Nigeria

The two-step enzymatic hydrolysis of Manihot esculenta and Sorghum bicolor using ƒ¿-amylase and amyloglucosidase were studied. The starch substrate were gelatinized at 80oC and then liquefied with the amylase enzyme at a temperature of 90oC. The samples are then cooled to 60oC and saccharified with amyloglucosidase. The effects of temperature and pH on saccharification process were considered. Results indicated that the optimum temperature for the conversion of starch to fermentable sugar (glucose) was at 60oC and the amount of glucose produced after 4 hours in sorghum was greater than that obtained when cassava was used. It was therefore concluded that optimum conditions for the production of glucose from both Manihot esculenta and Sorghum bicolor for bioethanol production are obtained at pH of 4 and saccharification temperature of 60oC, with Sorghum bicolor giving higher yield

Degradation Of Oil During Frying And Its Effect On Biodiesel Production

The effects of frying unripe plantain and sweet potato (separately) in soyabean oil on the properties of the oil were investigated. Also, the effect of the degradation of the oil on biodiesel yield obtained from the oil was considered. Physico-chemical properties of soyabean oil (acid value, saponification value, viscosity, density, colour) were measured daily after being used for frying for days. The fatty acid profile of the oil was analysed daily using GC/MS and biodiesel was produced daily from the oil sample. The results of the frying process showed increase in oil Acid values in the two cases; sweet potato (1.10 – 1.16mgKOH/g) and unripe plantain (1.12 – 1.71mgKOH/g). And increase in oil saponification values (146 – 271mgKOH/g for sweet potato and 175 – 340mgKOH/g for unripe plantain). The oil became less dense, less viscous and darker in colour for both batches during repeated frying. Five day Frying process reduced the percentage unsaturated fatty acid contents of oil (for unripe plantain from 81.94% to 36.80% and for sweet potato from 82.46% to 40.10%) and increased the percentage saturated fatty acid composition of the oil (unripe plantain from 12.18% to 34.70% and sweet potato from 12.24% to 27.50%). As frying progress, there was reduction in biodiesel yield, though insignificant difference in yield was observed between the biodiesel obtained from unripe plantain frying process and that obtained from the sweet potato frying proces

Methanolysis of Triglycerides Using Jatropha oil and Koh Catalyst

In this study, Jatropha curcas oil was used as feedstock for biodiesel production by alkali-catalyzed methanolysis. To establish the optimum conditions for biodiesel production, effects of certain factors were investigated, these factors are oil-to-methanol molar ratios (1:4 - 1:8), KOH catalyst concentrations (0.5 - 1.5% w/w oil), reaction temperatures (50 - 70ºC), and reaction times (55 - 90minutes). Biodiesel produced were analyzed to determine its viscosity, flash point and pour point. The experimental work revealed that optimum conditions for Jatropha curcas biodiesel production were oil-to-methanol molar ratio of 1:6, a catalyst concentration of 1.0% w/w oil, a reaction temperature of 60 °C, and a reaction time of 80 minutes. The methyl ester produced under these optimum conditions was 93.75 % w/w