64 research outputs found
Experimental investigation of different characteristics of Biodiesel derived from waste cooking and pure sunflower oil
No full textIn this investigation, waste cooking and pure sunflower oil were selected as feedstock for biodiesel synthesis under microwave irradiation and conventional heating systems. Experiments were conducted in order to evaluate the effects of reaction variables, such as catalysts amount (0.51.5wt %), oil: methanol volumetric ratio (4:1-8:1) and time (1-6 min) in microwave method and time (30-60 min) in conventional method. The best yield of biodiesel (97%) was obtained by the condition of 1 wt% NaOH, 4:1 oil to methanol volumetric ratio, and 4 min using microwave heating system. The important properties of biodiesel were analyzed and found to be within the limits of biodiesel standards. Compared with the conventional heating method the results show that microwave heating can be applied effectively to obtain high yield and reducing the reaction time from 1 h to 4 minutes. The use of microwave will help in providing an energy efficient and economical route for biodiesel production. Results also showed that the biodiesel obtained under optimum conditions from pure sunflower oil (PSO) and waste cooking sunflower oil (WCSO) exhibited no considerable difference but the cost of producing biodiesel from WCSO was lower than PSO. This research demonstrated that biodiesel obtained under optimum condition from PSO and WCSO was of good quality and could be used as a diesel fuel which is considered as renewable energy and environmental recycling process from waste oil after frying
Effect of ITO surface properties on SAM modification: A review toward biosensor application
No full textThe aim of this review is to discuss the effect of physical and chemical properties of Indium tin oxide (ITO) thin film on its self-assembled monolayer (SAM) modification, as well as device performance toward biosensor applications. The emphasis is on surface morphology studies of the thin films in order to provide connecting points between surface properties with the broader field of material science of ITO. The morphology of SAM film deposited on it directly affects by the properties of these prepared ITO film. Thus, it is a topic of interest to study the influence of physiochemical properties of this film on device fabrication and applications as biosensor platform
Den\u27isa sokutei baiosensa to shite no tanbunshimaku shushoku sanka injiumusuzu (ITO) denkyoku no riyo to tokusei hyoka
No full text制度:新 ; 報告番号:甲3454号 ; 学位の種類:博士(工学) ; 授与年月日:2011/10/27 ; 早大学位記番号:新577
Characterization and utilization of monolayer-modified indium tin oxide (ITO) electrode as a potentiometric biosensor =Den'isa sokutei baiosensa to shite no tanbunshimaku shushoku sanka injiumusuzu (ITO) denkyoku no riyo to tokusei hyoka
No full text制度:新 ; 報告番号:甲3454号 ; 学位の種類:博士(工学) ; 授与年月日:2011/10/27 ; 早大学位記番号:新5779tex
Arsenic mitigation measures in Bangladesh
No full textThe scale of arsenic toxicity of the groundwater in Bangladesh is greater than any environmental debacle in the history of human civilization. The main route of arsenic accumulation in the human body is the ingestion of arsenic tainted water. Because of the undetectable nature of arsenic poisoning at the early stage and lack of awareness due to mass illiteracy, poverty and malnutrition, arsenic related ailments may cause death. However, this paper mainly discusses arsenic mitigation measures in Bangladesh. Although a piped surface water supply after treatment is the absolute solution to get rid of this crisis, the weak economic background of Bangladesh does not support supplying such water to every corner of rural areas. Hence research groups have developed their own methods to suit the local environment, using locally available materials and approaches based on the common method of arsenic removal: use of oxidizing agents, followed by flocculation and precipitation. Again, among different alternative water supply options, deep tubewells, which have been used by the communities in Bangladesh during the past few decades, appear to be a more suitable alternate option. Moreover, household-based arsenic filters can be a good choice if proper maintenance can be done.L’accroissement du problème de toxicité causé par l’arsenic au Bangladesh constitue une catastrophe environnementale majeure dans l’histoire de l’humanité. La principale voie d’accumulation de l’arsenic dans le corps humain est l’ingestion d’eau polluée par ce contaminant. La nature indétectable de l’empoisonnement à l’arsenic dans les premières étapes, l’insuffisance d’avertissement attribuable à l’analphabétisme, ainsi qu’à la pauvreté et la malnutrition, font en sorte que l’empoisonnement progressif à l’arsenic peut causer la mort. Le présent article discute toutefois les mesures d’atténuation envisagées au Bangladesh. Ainsi, bien que l’alimentation dans des conduites avec de l’eau de surface traitée représente la solution idéale pour résoudre cette crise, l’état économique précaire du Bangladesh ne permet pas d’alimenter en eau de surface traitée toutes les populations des zones rurales. De là, des groupes de recherche ont développé des méthodes spécifiques à l’environnement local en utilisant des matériaux disponibles sur place et basées sur une méthode établie d’enlèvement de l’arsenic : en utilisant des agents oxydants suivi par la floculation et la précipitation. Parmi les différentes alternatives d’alimentation en eau explorées, la technique de puits profonds, laquelle a été utilisée par les communautés au Bangladesh durant les décennies passées, apparaît être l’option la plus appropriée. De plus, l’emploi d’unités de filtration dans les résidences peut être un bon choix, dans les cas où celles-ci sont entretenues adéquatement
Characterization and Compositional Analysis of Indian Black Aggregate as a Concrete Raw Material
No full textThe study is conducted to find the applicability of Indian black aggregate as a concrete material through a series of physiochemical and surface morphological investigation. The report reveals the effects of different chemical properties on concrete performance which ultimately affect life period of any structure. Mineralogical and Chemical characterization of the aggregate was analysed by UV visible spectroscopy (UV-vis), X-Ray Fluorescence (ED-XRF) and X-Ray Diffraction (XRD). Scanning electron microscopy (SEM) used to know Surface morphology of the aggregate. It was observed that studied aggregate contains high amount of MgO (4.36%) and Fe2O3 (14.84%). However, it is quite stable up to 800 oC with loss of only 1.58% of gross weight. The surface morphology analysis clearly revealed the existence of Calcite, Quartz and Dolomite materials in studied aggregate
Modelling seasonal rainfall forecasts forced with improved predictive ocean surface temperature
No full textSeasonal rainfall forecasts are in high demand for users such as irrigators and water managers in decision making and risk management. Both statistical and dynamical models are widely used to generate probabilistic rainfall forecasts in advance for a season. Statistical prediction systems establish a stationary relationship between the predictor and the predictand variables, for example, sea surface temperature anomaly (SSTA) patterns over the Indian and Pacific Oceans are found to provide probabilistic seasonal rainfall forecast throughout Australia. On the other hand, dynamical models are based on the laws of physics and thus they can capture non-linear interactions of the atmosphere, land and ocean. In the case of seasonal forecasts, these models use a two-tiered process by predicting global Sea Surface Temperatures (SSTs) first; an atmospheric general circulation model (GCM) is subsequently forced by the pre-forecast SST to make a seasonal prediction. Improvement in predicted SST is therefore significant for issuing better concurrent seasonal rainfall forecasts. Consequently the motivation of this research is to improve seasonal SST forecasting on a global scale and accordingly provide concurrent seasonal rainfall prediction by applying statistical techniques and similarly forcing a climate model.
For the purpose of improving seasonal SST forecasting, this thesis presents a multimodel combination approach which considers intermodel dependency between the multiple participating GCMs. The algorithm provides globally gridded SSTA for a season ahead based on the degree of correlation between the forecast errors and the relative size of each model s error variance. This methodology demonstrates an attractive way of improving seasonal SSTA forecasts over the majority of grid cells in the globe compared to the recent multimodel approach wherein the correlations are ignored. The standard practice of multimodel approach by pooling the models over a common time period can, however, cause loss of information if some models have a longer period of data. Hence this thesis also presents another simple approach of combining models which have variable data lengths.
In the second part of this thesis, concurrent seasonal rainfall forecasts are issued from the improved SST, and single model SST predictions separately. The statistical techniques Bayesian Joint Probability (BJP) and Bayesian Model Averaging (BMA) are applied to translate seasonal rainfall forecasts using six predicted SSTA indices over the Indian and Pacific Oceans. The BJP-BMA approach shows encouraging results derived from improved SSTA indices, although no upper atmosphere predictor variable is considered. In addition, the global climate model ACCESS is used to issue concurrent seasonal rainfall prediction on a global scale from the improved forecast SST. The results indicate that there is merit in formulating global seasonal rainfall forecasts from the predictive uncertainty reduced SST, rather than relying on a single model predicted SST
Separation of Acetic Acid from Aqueous Solution using Various Organic Solvents
No full textIn the study a model has been developed to separate the acetic acid from aqueous solution by liquid-liquid extraction and find out the proper solvent for this separation. Various solvents such as n-butanol, iso butanol, amyl alcohol and ethyl acetate are used for separation of acetic acid from water. The binodal curves (mutual solubility curves) for acetic acid distributed between water and an organic solvent were obtained by titrating known mixtures of two components (water and solvents) with the third component acetic acid to the point of first appearance of permanent turbidity. In order to determine the tie-lines, the absorbance of the coexisting phases, obtained by the separation of ternary mixtures within the binodal curve are needed to be determined. The absorbance of each point had been determined by a UV spectrophotometer. Distribution diagrams are obtained by plotting weight percent of acetic acid in solvent phase against the weight percent of acetic acid in water phase. Selectivity diagrams are also obtained by plotting (wt. % of acetic acid) / (percent of acetic acid + percent of water) in solvent phase against the same quantity in the diluent phase. The separation factor is determined numerically from the tie-line data
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