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Physical properties of coconut shell nanoparticles
Get PDFPhysical properties such as apparent density, bulk density, compressibility index and particle sizes of carbonized and uncarbonized coconut shell nanoparticles produced through top down approach have been studied. Percentage composition of the coconut fruit was determined using five different coconut fruit samples. Results revealed that coir occupies the highest percentage; coconut shells account for 15 % while the flesh and liquid occupy 30 % of the whole coconut fruit. The apparent densities of the uncarbonized and carbonized coconut shell nanoparticles obtained at 70 hours of milling are 0.65 g/cm3 and 0.61 g/cm3 respectively. Their respective compressibility indices and average particle sizes are 46.4 % and 69.7 %; 50.01 nm and 14.29 nm. The difference in the particle sizes of the carbonized and uncarbonized coconut shell nanoparticles can be linked with reduction in the moisture content and volatiles of the carbonized coconut shell nanoparticles due to carbonization process. The reduction in the moisture and volatiles results in the enhanced hardness and brittleness of the carbonized coconut shells which facilitate their breakage during the course of milling than that of the uncarbonized coconut shells. 
Optimization Model for Compressive Strength of Sandcrete Blocks Using Cassava Peel Ash (CPA) Blended Cement Mortar as Binder
Get PDFThis research work applies Scheffe’s second degree simplex theory to formulate a regression model for the optimization of the compressive strength of sandcrete blocks using cassava peel ash (CPA) blended Portland cement (OPC) as binder material for different mix ratios as multivariate functions with the proportions of the sandcrete block ingredients serving as variables. The experimental values of the compressive strength were obtained by performing destructive strength tests on the blocks after curing for 28 days, with a binder-aggregate ratio of 1:8 and water binder ratio ranging from 0.45 to 0.60, the OPC being replaced with CPA at 0 – 30% for the respective water-binder ratios. The optimization model from the Scheffe’s mixture method for a (4, 2) factor space was found to be y= f(x) = 1.95x1 (2x1-1) + 1.84x2 (2x2-1) +1.81x3 (2x3-1) +1.79x4 (2x4-1) + 6.08x1x2 + 5.72 x1x3 + 1.89 x1x4 + 7.28 x2x3 + 1.80 x2x4 + 7.16 x3x4. The model was tested using the student t- test at 95% accuracy and found to be accurate. Thus, the model can be used to predict any desired compressive strength value for CPA-OPC blended sandcrete blocks given any water-cement ratio between 0.45 and 6.0 and vice versa
Study on The Effect of Soft Story on Infill RC Frames Under Seismic Effect
Get PDFConstruction practice of reinforced concrete (RC) frames infilled with unreinforced masonry is quite common now-days in urban cities in Nepal and elsewhere. Previous study shows the lateral load transfer mechanism is different than that of bare frames in infill buildings. Because of the unavoidable circumstances like elimination of central columns, elimination of infill wall in basement for parking purpose and reducing the size of frame members etc. may cause the particular story to be soft
Suitability study of soybeans husk ash as a mixing material to OPC: Effect of calcination time-preliminary investigation
Get PDFSoybeans husk was collected from a dump site, dried de-carbonated, separated into six samples and calcined at a temperature of 600 °C, for 1, 2, 3, 4, 5 and 6 hours respectively. Samples were taken for X- ray Florescence (XRF) analysis, Standard Electron Microscopy (SEM) imaging, setting time, standard water of consistency determination and specific gravity test. The result of XRF analysis revealed that the SHA contain less than 70 % SiO2+Al2O3+Fe2O3 stipulated by ASTM C618 for pozzolanas, but has very high CaO content. The SiO2 +Al2O3+Fe2O3 and CaO content though varies slightly with the calcination time of soybean husk. The specific gravity of SHA varies with calcination time of SH and ranges between 2.3 and 2.7 and is less than that of OPC irrespective of the calcination time. Setting times of OPC/SHA pastes at 10 % replacement of OPC with SHA increases with calcination time and is greater than that for OPC paste. The SEM analysis shows that the crystal structure of the SHA changes with calcination temperature. The compressive strength of mortar using OPC/SHA as a binder was determined after 7, 14 and 28 days curing and was found to be less than that for OPC mortars at all ages. However, the percentage reduction in strength decreased with curing age, with SHA calcined at 4 hours having the greater strength (i.e. 87.4 % of OPC strength at 28 days). The percentage gain in strength was more pronounced from 7 to 14 days. In all, SH calcined at 600 °C for 4 hours optimizes the pozzolanic potential of SHA
Effect of incubation temperatures on mycelial growth, conidial features and density of Stemphylium botryosum Walr isolates
Get PDFThe cultural and morphological variability of Stemphylium botryosum Walr was studied with five isolates viz. isolate 1 (Stb-I1), isolate 2 (Stb-I2), isolate 3 (Stb- I3), isolate 4 (Stb-I4) and isolate 5 (Stb-I5) collected from Parsa, Rautahat, Dang, Banke and Chitwan districts of Nepal respectively during 2011-2012 crop season with Completely Randomized Design (CRD) maintaining 3 replications at Plant Pathology Laboratory of Grain Legumes Research Program (GLRP), Rampur, Chitwan. Single spore isolation technique was followed to isolate the pathogen. The pathogen was grow on Potato Dextrose Agar (PDA) and incubated with different temperatures in BOD incubator. The calibrated ocular micrometer was used to measure the length and breadth of the conidia while conidial count with sporulation intensity was attempted with hemocytometer. The mycelium color of the different isolates was varied from white, grey, brown and brownish black in peripheral part while mostly black pigmentation was noticed in lateral part of the culture plate. The shape and texture was regular and velvety for most isolates and in some isolate, roughly irregular shape with cottony texture was found. The higher colony diameter of 7.66 cm and conidial dimension of 29.42×18.12 μm (L/B ratio-1.62) with profuse sporulation intensity (46.67 conidia /0.01 ml) was observed at 25 °C after 15 days of incubation on PDA. However, 2.84 cm diameter, 19.58×9.81 μm (L/B ratio-2.00) with poor conidial density (7.60 conidia /0.01 ml) was noticed at 10 °C. The observation at 10 and 35 °C was at par in case of mycelial growth, conidial features and sporulation intensity. Mostly conidia of all isolates were brown in color at lower incubation temperature but they became dark grey brown at 25 and 30 °C and grey color was noticed when incubated at 35 °C on PDA after 15 days of incubation
Microstructure and corrosion characteristics of cast silicon bronze in ammonia environment
Get PDFRefrigerating systems operating on either the open re-circulation or chilled water circuits are proned to corrosion attacks. Often, the ensued corrosion products foul and inhibit efficient heat transfer within the system causing leaks resulting in catastrophic failures. Thus, the imperative to search for a material that can be an effective substitute for the conventional copper pipe used in most refrigerating systems. In this study, the microstructure and corrosion susceptibility of cast silicon bronze in anhydrous ammonia environment was investigated. The silicon bronze was produced by sand casting with the silicon varied from 1-4 wt. %. An accelerated electrochemical polarisation technique was employed to simulate the corrosion behavior of the cast alloy. The results show relatively low corrosion susceptibility, 0.75 mm/yr of the alloy in anhydrous ammonia. This may be attributed to the silicon dioxide (SiO2) passive film formed on the surface of the alloy. The effectiveness of the SiO2 passive film increases as the wt. % of silicon addition increased. The potential for drastic reduction in maintenance cost and frequency of call-backs of refrigerating units is enhanced by the outcome of this study
Isolation of Phosphate Solubilizing Bacteria and their Use for Plant Growth Promotion in Tomato Seedling and Plant
Get PDFPhosphorous (P) is an essential macronutrient and most soils contain high levels of P. However, its availability to plant is limited by rapid immobilization of phosphorous compounds to insoluble forms and hence plant available forms of P in soils are found in low amounts. Phosphate solubilizing bacteria provide an eco-friendly alternative to convert insoluble phosphates into plant available forms. In the present study, three phosphate solubilizing bacterial isolates (PB-1, PB-4 and VC-01) with visually significant phosphate solubilizing abilities were isolated from tomato rhizosphere soil. In-vitro study in pikovskaya’s agar revealed that isolate PB-1 had the highest phosphate solubilizing ability with a phosphate solubilizing index of 2.08±0.07 followed by isolate VC-01 (1.31±0.09) and PB-4 (1.24±0.08). Isolates were used as bacterial inoculum to assess their ability to promote tomato (Lycopersicon esculentum var. Srijana) seedling and plant growth in in-vitro and greenhouse experiment respectively. Isolate PB-4 showed best growth promotion in seedling assay whereas isolate PB-1 and VC-01 also promoted seedling growth compared to control. In greenhouse experiment however, isolates VC-01 and PB-1 significantly enhanced all parameters (shoot length, root length, shoot and root dry weight) compared to uninoculated control whereas isolate PB-4 had a positive effect on all parameters except root length
A common fixed point theorem for subcompatible mappings in fuzzy metric space
Get PDFThe aim of the present paper is to establish a common fixed point theorem for subcompatible pair of self mappings in a fuzzy metric space which generalizes and improves various well-known comparable results
Development and validation of RP-HPLC method for the determination of Darifenacin Hydrobromide in bulk drug and pharmaceutical dosage form
Get PDFThe main objective of present study is to develop and validate a new, simple, precise and accurate RP-HPLC method for the determination of Darifenacin Hydrobromide (DFH) in bulk and pharmaceutical dosage forms. The separation and quantification of the drug was achieved on a RP C18 column (250×4.6mm, 5μm) using a mobile phase of acetonitrile: buffer (50:50), pH 3.0 ± 0.2 at a flow rate of 1 mL/min with detection of analyte at 287 nm. The separation was achieved with in 4.0 ± 0.3 min. The method showed good linearity in the range of 10-100 μg/mL. The intra and inter day RSD ranged from 0.20-0.58%. The recovery (mean ± SD) of low, medium and high concentrations were 98.50 ± 0.20, 100.27 ± 0.15 and 100.90 ± 0.09 respectively. The limit of detection and limit of quantification were 0.31 and 0.61 μg/mL, respectively. It can be concluded that the present method could be superior over the methods which were reported earlier. 
Soil properties during transition from conventional to organic farming system in Kavre District, Nepal
Get PDF The aim of this study was to investigate the response of soil physical and chemical properties during the transition from conventional to organic farming system. Soil samples were collected from five different farms: “Hasera organic farm” under 10 years of organic farming, “Everything organic nursery” under 5 years of organic farming, “Grameen Krishi” under 3 years of transition from conventional to organic, “Gautamshree farm” under 1 years of transition from conventional to organic and “Kuntabeshi farm” under IPM practice as reference. Soil bulk density, moisture content, texture, NPK, CEC and soil organic matter was evaluated in soil samples collected at 0-15 cm. Soil organic matter (5.45%) was highest in Hasera farm, whereas lowest bulk density (1.02gcm-3) was also in Hasera farm. Lowest soil organic matter content was found in Gautamshree farm. Soils of all farms were under loam texture. Soil macronutrients were highest in Grameen Krishi farm. The overall pH value of all soil samples was slightly acidic to acidic