399 research outputs found

    Scaling small-scale mechanization in the Ethiopian Highlands

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    An analysis of algebraic pattern of a first order and an extended second order Runge-Kutta Type Method

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    The algebraic pattern of a 6-Stage Block Hybrid Runge –Kutta Type Methods (BHRKTM) for the solution of Ordinary Differential Equations (ODEs) is carefully analyzed. The analysis of the methods expressed in the Butcher Tableau led to the evolvement of two equations that satisfy the Runge – Kutta consistency conditions. The reason behind the uniform order and error constant for the developed first order and extended second order methods is explained using the theory of linear transformation and monomorphism. The pattern was retained during the transformation

    The Influence of Integrated Gravity Circuit on the Efficiency of Gold Extraction at a Carbon-in-Leach Plant

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    In gold ores, the precious metal particles may occur as nuggets (> 0.5 mm) and down to sub-microscopic particles. Coarse particles are generally recovered by gravity concentration before leaching the bulk material with sodium cyanide to enhance leaching efficiency. A mine in West Africa operates a carbon-in-leach (CIL) plant where a gravity circuit has recently been installed. The purpose of this study was to investigate the effect of the gravity-integrated circuit on the overall efficiency of metallurgical operations in the CIL plant. In this investigation, a quantitative research approach was selected to determine the variables in analysing the influence of the integrated gravity circuit on the efficiency of gold extraction. The general plant efficiencies before and after the installation of the Gravity Recoverable Gold (GRG) circuit were investigated, with a focus on the milling circuit, CIL circuit, and reagent consumption in the various circuits. A model was constructed using multiple linear regression analysis, and the relationship between the variables was determined. From the results, the mill's throughput increased from 13.5 million tonnes per year to 13.9 million tonnes per year after the installation of the GRG circuit. In models 1 and 2, all coefficient p-values were less than the 5% significance level chosen for the study. Cost-benefit analysis of reagent use before and after gravity installation showed that the plant consumption of reagents decreased from 43 264 – 36 481 tonnes, 13 144 – 10 141 tonnes, 1 779 – 1 538 tonnes, 3 208 – 1 551 tonnes, 9 274 – 8 045 tonnes for lime, sodium cyanide, activated carbon, hydrochloric acid and caustic soda respectively. Again, the GRG circuit dramatically reduced the gold loadings onto activated carbon with an overall reduction in tailing grade and increased the gold recovery rate and purity by 1% and 2%, respectively. Overall, the mine's annual ore processing capacity increased by 2.34 %. Therefore, installing additional Knelson concentrators (gravity units) can be key to addressing the excess gravity-recoverable gold suspected to exist in the circuit with continuous checks and balances performed

    The Concept of Single Use Piston Break Safety Syringe

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    syringe is a simple piston pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube (the barrel), allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube. The open end of the syringe may be fitted with a hypodermic needle, a nozzle, or tubing to help direct the flow into and out of the barrel. Syringes are often used to administer injections, apply compounds such as glue or lubricant, and measure liquids. The reuse and abuse of syringe has led to cross-infection of diseases; thus, the need of single use safety syringe arises. Single use safety syringe is able to prevent the abuse of syringe. Many inventions have been produced; the most common are through-push retract breakable safety syringe, rotary plunger retractable safety syringe and release-ring breakable safety syringe. A new type of single use safety syringe Piston Break Safety Syringe is discussed in this paper. Common safety syringes available in market consist of three major components as described earlier. Beside its simplicity, the low cost to produce also the main factor why this type is very popular. The new Piston Break Safety Syringe has similar design with this widely used safety syringe; hence, it makes it easier to be adapted by the users due to its similarity, since no extra training to use it is required. The cost should be equivalently low due to the similarity in size, design and number of components

    Does Inhalation of Virgin Coconut Oil Accelerate Reversal of Airway Remodelling in an Allergic Model of Asthma?

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    Many studies have been done to evaluate the effect of various natural products in controlling asthma symptoms. Virgin coconut oil (VCO) is known to contain active compounds that have beneficial effects on human health and diseases.The objective of this study was to evaluate the effect of VCO inhalation on airway remodelling in a rabbit model of allergic asthma.The effects of VCO inhalation on infiltration of airway inflammatory cells, airway structures, goblet cell hyperplasia, and cell proliferation following ovalbumin induction were evaluated. Allergic asthma was induced by a combination of ovalbumin and alum injection and/or followed by ovalbumin inhalation.The effect ofVCOinhalationwas then evaluated via the rescue or the preventive route. Percentage of inflammatory cells infiltration, thickness of epithelium and mucosa regions, and the numbers of goblet and proliferative cells were reduced in the rescue group but not in preventive group. Analysis using a gas chromatography-mass spectrometry found that lauric acid and capric acid were among themost abundant fatty acids present in the sample. Significant improvement was observed in rescue route in alleviating the asthma symptoms, which indicates the VCO was able to relieve asthma-related symptoms more than preventing the onset of asthma

    Biosorption of Mercury by Selected Plants – a Preliminary Study

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    Traditionally, mercury (Hg) is considered among the most toxic elements with several major health issues and serious environmental challenges. With the frequent release of Hg from artisanal and small-scale gold mining (ASGM) operations, aquatic plants or staple crops in environments polluted with mercury may accumulate significant amounts of mercury. Thus, result in mercury entering the food supply chain posing health challenges to humans. In order to ascertain the bio-sorption characteristics of some staple crops for mercury; beans, millet, corn and groundnut were tested. The plants were contacted with 10 mg/L and 50 mg/L solution of mercury concentration for 7 days followed by subsequent metal analysis of residual solution. The results delineate that, metal uptake ranges of 4.6-9.3 mg/l, 3.2-9.6 mg/l, 4.7-9.3 mg/l and 3.0-7.7 mg/l for beans, corn, groundnut and millet respectively for the 10 ppm Hg solution. In addition, 16.2-42.0 mg/l, 18.2-35.7 mg/l, 17.6-34.2 mg/l and 26.0-30.2 mg/l are the Hg metal uptake ranges for the 50 ppm concentration. This shows that the plants have the capacity to uptake mercury metal to certain degree. This also confirms that beans, corn, millet, and groundnut are potential bio-accumulators of mercury in mercury contaminated sites. Notably, the findings from this study affirm the hypothesis that in situations where the mercury is bioavailable, some food items harvested in such polluted areas may eventually enter the food chain

    My_Atmos: Novel Method to Analyse Ultrafine Particles Using an Artificial Intelligence Approach

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    This presentation will discuss the used of an artificial intelligent method namely the ‘stochastic boosted regression trees’ (BRT) approach that uses an algorithm that applied to an air pollution data namely particle number count concentrations ([PNC]), an ultrafine particles data and particulate matter data case study in United Kingdom and Malaysia. The development of the BRT model involves determining the model algorithm settings of the main model input parameters (learning rate, number of trees and interaction depth) that were tested using the R software (version 3.02) by choosing a10-fold cross-validation approach with combination of lr 0.05 and tc 5 of training set for BRT models. It was found, that the coefficient of determination (R2) value for the BRT best iteration models were above 0.60 for [PNC] in urban environment. The fine and course particle number (FPNC and CPNC) were found to be 0.75 and 0.72 respectively for one of coastal dataset while R2 value of 0.78 and 0.85 were obtained for Malaysia data. Further investigated were performed to rank factor influenced. It was found, that Carbon monoxide (30.28 %) gas and followed by temperature (16.81%) and wind direction (16.4%) were found the high factor influenced PM10 in urban environment. The interaction index (H-index) between parameters to concentration of pollutants were also examined graphically and in numerical form (H-Index). It was found that the H-Index between parameters 0.3 to 0.4 indicated that the BRT technique able to explain the science of air pollution. The consistent results to produce the best model from the best iteration, able to rank the best parameters that influence most to the concentration of predictor and able to predict interaction between variables premise BRT as one of the method or tools to analyse air pollution data

    Conservation agriculture/farmers mechanization: Africa RISING science, innovations and technologies with scaling potential from the Ethiopian Highlands

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    United States Agency for International Developmen

    Experimental Study on Effect of Reflector Bed Designs Heated by Direct Solar Radiation for Hot Water Storage System

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    The aim of this research is to investigate the performance of different reflector bed design heated by direct solar radiation for a water storage system that can be used in accordance with the climate of Malaysia country. In general, this research is related to thermal efficient water heating system, specifically to improve the water heating system that exists nowadays. The focus is to improve the thermal efficiency by adding different absorber bed designs. Based on experimental results shown the temperature of the water increases more efficient and faster by using the curve reflector bed

    Corrosion behaviour of Al-Si cast alloy reinforced with titanium diboride (TiB2) and scandium (Sc)

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    The aluminium-silicon (Al-Si) based on Metal Matrix Composites (MMCs) is widely used in lightweight constructions and transport applications requiring a combination of high strength and ductility. A grain refinement plays a crucial role in improving characteristics and properties of Al alloys. In this investigation, titanium diboride (TiB2) and scandium (Sc) inoculants were added to the Al-Si alloys for grain refinement of an alloy. In this investigation, the corrosion resistance rate of Al-Si cast alloy reinforced by TiB2 and Sc were measured by potentiostat (AUTOLAB) instrument. The aim of this research is to investigate the corrosion rate for Al-Si-TiB2-Sc composites that immersed in different concentration of acidic solutions. Besides, the immersion time of acidic solutions also was investigated. All the samples were prepared accordingly for ASTM standard by the composition of 6.0 wt% TiB2 and 0.6wt% Sc. All the samples undergo cold mounting technique for easy handling on corrosion tests. Then the samples were immersed in two different concentrations acidic medium solutions, which were 0.1.and 1.0 M hydrochloric acids (HCl). The corrosion rate also was investigated for immersion samples of 1.0 M HCl for 21 days. From the results obtained, added TiB2 and Sc onto Al-Si alloy gave the better properties in corrosion resistance. Corrosion rates to reduce when the samples were immersed in a lower concentration of acidic medium, 0.1 HCl. However, there are some significant on the result but it still following the corrosion rates trend. Thus, improvements to reinforcement content need to be done in further research to cover the lack of this corrosion rates trend
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