This article presents the mixing parameters of fly ash geopolymer based on NaOH concentration (6M - 14M), S/L ratio (1.0 - 3.5), Na2SiO3/NaOH ratio (1.0 - 3.0) and ladle furnace slag replacement (10% -40%). Additionally, a comparative study between fly ash geopolymer and fly ash/slag geopolymer with respect to the bulk density, water absorption, apparent porosity and compressive strength were investigated. The general bulk densities of fly ash/slag geopolymer were higher than fly ash geopolymer. The apparent porosity and water absorption of fly ash/slag geopolymers were comparatively lower than fly ash geopolymers. High compressive strength achieved by fly ash/slag geopolymer was contributed by high bulk density and low apparent porosity and water absorption. In other words, fly ash geopolymer obtained lower strength was due to lower bulk density and higher apparent porosity and water absorption.

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Copper based materials are widely used in industrial and marine applications due to good mechanical properties and high corrosion resistant behavior. But the corrosion immunity varies for the variation of environmental factors. Moreover, alloying elements can have role on corrosion behavior, especially if it occurs through inclusion of Sn-Pb solder for repair works and environmental effects due to ageing. The present paper is an attempt to characterize the corrosion immunity level of copper after inclusion of tiny SnPb-solder material and work hardening in pH varied fresh water environments from pH1 to pH13 using gravimetric analysis, conductivity investigation and micrograph observation using optical as well as field emission scanning electronic microscope. The result reveals that solder material inclusion has increased the corrosion rate by about 14% in 30 days immersion in pH varied environments.

Oil from neem and yellow oleander seeds were extracted using Soxhlet extractor with normal hexane as solvent and characterized using standard methods and their Physico chemical properties determined. The results revealed that the oil yields of neem and yellow oleander seeds are 38.80% and 49.69% respectively. Both oil samples contain high free fatty acid values, 8.77% for neem and 7.21% for yellow oleander. The characterization revealed the following results for neem seed oil; saponification value = 185.50 mg KOH/g, acid value = 17.54 mg KOH/g, iodine value = 58 mg I/100g, peroxide value = 7.95 mg/peroxide/kg, viscosity at 40 °C = 37.80 mm/s2, specific gravity = 0.87, and refractive index = 1.469 while saponification value = 196.30 mg KOH/g, acid value = 14.42 mg KOH/g, iodine value = 81 mg I/100g, peroxide value = 4.20 mg/peroxide/kg, viscosity at 40 °C = 31.40 mm/s2, specific gravity = 0.96, and refractive index = 1.467 for yellow oleander seed oil. The results of the experimental analyses carried out in this study indicate that neem and yellow oleander seeds are high-yielding and good sources of oil for commercial biodiesel production. Values obtained for physico chemical properties of the extracted oils fall within the acceptable limits for oils suitable for biodiesel production by international standards. High free fatty values obtained revealed that the oils must undergo acid esterification before transesterification to avoid the formation of soap.

Nanocrystalline Li4Ti5O12 was synthesized using solid state reaction method. The influence of sintering temperature on chemical composition and microstructure was studied. The Li4Ti5O12 powder sintered at 900 ?C exhibited predominant (111) orientation representing cubic spinel structure with particle size of 46 nm. The composition and phase were confirmed from TG and EDX measurements. The displayed bright spots with clear diffracted rings in SAED pattern corresponding to characteristic orientations confirm the cubic spinel LTO phase. The pure LTO electrode exhibited a discharge specific capacitance of 265 F/g at current density of 0.5 A/g with good cycling stability (81%) after 5000 cycles. The significance electrochemical properties are attributed to the phase purity of LTO with low particle size which provides improved conduction paths.

The goal of the research was to find out optimum hydrolysis parameters to convert corn stover to bioethanol using response surface methodology. The pretreatment of corn stover was administered using alkali potassium hydroxide. The results of the pretreated indicated that the important elements of corn stover were cellulose, hemicellulose, and lignin, 35.23, 23.5, and 16.3% respectively. Additionally, cellulose is the main component of cornstover that is sufficient for biofuel production. Experimental layout and statistical evaluation were carried out using the response surface technique. Acid concentration at (1.5-2.5%, w/w), particle dimension (0.15-0.25 mm), temperature (125-145 °C) and time (30-80 min) were used to evaluate the hydrolysis parameters. The result indicates that the optimum hydrolyzed parameters were, acid concentration; 2.334 (w/w %), particle size; 0.153 mm, temperature; 144.976 0C, and time; 77.233 minutes. The optimized independent variables were derived from the quadratic model and selected primarily based on the highest desirability. Under these conditions, the yield of glucose and xylose was 48.69 and 33.091% respectively. After 48 h of fermentation time, 27.1 g of ethyl alcohol concentration was investigated (this is equivalent to 92.07% of theoretical yield of ethyl alcohol at optimized conditions).