STATISTICAL OPTIMIZATION AND SENSITIVITY ANALYSIS OF RHEOLOGICAL MODELS USING CASSAVA STARCH

Models are sometimes employed to determine some parameters that can be used to distinguish between different types of food samples. Rheological models can be used to predict flow for severe conditions where it is difficult to determine the nature of the fluid flow, consequently it is essential to select the appropriate rheological models. This study aims to propose a rheological model that describes an ideal cassava starch rheological behavior and its influence on state variables such as concentration and temperature in order to validate the rheological models. In this study, five rheological models (namely; Power-law model, Robertson-stiff model, Herschel-Bulkey model, Prandtl-Eyring model and Bigham plastic model) were amended into various statistical model by adding the error variance (e). This study concludes that Herschel-Bulkley model and Robertson-stiff model closely explain the rheological patterns occurring during the production of cassava starch. The sensitivity evaluation of other rheological models demonstrate that the validity of Power-law model, Herschel-Bulkley model and Robertson stiff model is not notably influenced by changes in concentration and temperature of the cassava starch. Nevertheless, the Prandtl-Eyring and Bingham plastic models are noted to have less reliable prediction at lower temperature and higher concentration respectively

Optimization of Oil from Moringa oleifera seed using Soxhlet Extraction method

Extraction of oil from Moringa oleifera seed using Response Surface Methodology (RSM) was investigated. Effects of three factors namely: sample mass, particle size and extraction time on the response, Moringa oleifera a volume extracted, were determined. The Box-Behnken design of RSM was employed which resulted in 15 experimental runs. Extraction was carried out in a 250 ml Soxhlet extractor with Hexane and Ethanol as solvent. The Moringa oleifera seed powder was packed inside a muslin cloth placed in a thimble of the Soxhlet extractor. The extraction was carried out at 60ºC using thermostatic heating mantle. The solvent in the extracted oil was evaporated and the resulting oil further dried to constant weight in the oven. This study demonstrates that Moringa oleifera oil can be extracted from its seed using ethanol and acetone as extraction solvent. The optimum process variables for both solvent (ethanol and acetone) was determined at sample weight of 40 g, particle size of 325 μm and extraction time of 8 hours. It can be deduced that using acetone as solvent produces a higher yield of oil at the same optimum variable conditions compared to when ethanol was used

Investigation into Alternative Energy Sources from Waste Citrus Peel (Orange): Approach to Environmental Protection

An experimental study has been carried out on an alternative source of energy from citrus peel waste. A widely used material, pectin, has been extracted from orange peel (OP) and subsequently converted into ethanol with the use of a bacteria and fungi. Dried peels were split into several particle sizes of 0.075, 0.5, 1.0 and 5 mm. It was noted that OP with 0.75 mm particle size produced pectin of low volume while larger 1.0 mm OP particle size produced a high pectin volume. OP of 802 g was used to produce 1,770 ml of pectin, this illustrate that citrus fruit (specifically orange) contains pectin in a large quantity. A mixture of E.coli (bacteria) with yeast (fungus), and their individual components were used on pectin obtained. However, it was observed that a mixture of pectin, E.coli & S. cerevisiae, and a combination of sample pectin with E.coli produced an encouraging volume of ethanol as against no ethanol produced when a mixture of sample pectin, yeast and pectin sample only. The amount of energy contained in the gross ethanol produced was 1526.6 btu, this can be combined with purified gasoline so as to attain the optimum energy content that can be used to run an indigenous processing plant for citrus fruit in Nigeria

Soybean Oil Biodiesel Production using Renewable Catalyst Synthesized from Guinea Fowl Eggshells.

The need for a sustainable energy has given rise to the search for a renewable source of energy. This research study presents the production of soybean oil biodiesel using synthesized guinea fowl eggshell catalyst (renewable catalyst). The catalyst preparation involves calcination at 850 0C for 3 hours in a muffle furnace. It was characterized using X-Ray Flourescence (XRF) and Scanning Electron Microscopy (SEM). Biodiesel was produced using 3-8 wt % of calcined catalyst within a time range of 1-2 hour, methanol/oil ratio of 0.25-0.5 w/w%. The highest biodiesel yield was 87.6% at optimum conditions of 8 wt%, 1.5 hours and 0.25 w/w% for catalyst amount, reaction time and methanol/oil ratio respectively. The biodiesel produced validates the successful synthesis of the guinea fowl eggshell into CaO. Biodiesel was then characterized to determine the acid value, flash point, cetane number, specific gravity, density, iodine value and kinematic viscosity. The characterization result of the biodiesel synthesized by using the guinea fowl eggshell catalyst produced showed that the biodiesel produced compares favorably with ASTMD standard

Effective Doses and Excess Lifetime Cancer Risks from Absorbed Dose Rates Measured in Facilities of Two Tertiary Institutions in Nigeria

This study was aimed at examining the radiation absorbed dose rate, annual effective doses and excess lifetime cancer risks of halls of residence, Radiotherapy Unit and Radiology Department of UI, UCH and UNIMEDTH respectively. Results of measurements show that the mean absorbed dose rate for male and female hall are 0.33 ± 0.05476 and 0.17 ± 0.05074 µSv h-1 respectively. The mean overall absorbed dose rates calculated for facilities studied are 0.269 ± 0.0992 µSv h-1, 0.121 ± 0.036 µSv h-1 and 0.123 ± 0.00931 µSv h-1 in UI, UCH and UNIMEDTH respectively. The mean annual effective doses recorded in both male and female halls in University of Ibadan ranges between 0.71 mSv y-1 and 2.67 mSv y-1. The mean annual effective doses obtained from the facility of University of Medical Sciences Teaching Hospital, Ondo (UNIMEDTH) ranges between 0.17 and 0.44 mSv y-1. In addition, the mean annual effective doses calculated from the measured absorbed dose rate in Radiotherapy Department of University College Hospital, Ibadan ranges between 0.20 and 1.22 mSv y-1. As regards ELCRs, the mean values  determined in various facilities examined are 6.07 x 10-3 (Male Halls, UI), 3.27 x 10-3 (Female Halls, UI), 0.57 x 10-3 (UNIMEDTH- NE), 0.99 x 10-3 (UNIMEDTH- EX), 0.65 x x 10-3 (Teletherapy, UCH) and 0.57 x 10-3 (Brachytherapy, UCH).The mean ELCRs of both halls examined are higher than the world average of 1.45 x 10-3 and the standard value of 0.29 x 10-3 by at least a factor of 1.97 units

Kinetics study of biologically remediated crude oil polluted soil using a bacteria and fungi

The optimum conditions for the fermentation of a local legume known as African locust bean (Parkia biglobosa) into a vegetable protein based food condiment or spice (Iru) were developed using Levenberg-Marquardt (or Powell) method (using PSI software) with three (3) variables namely; inoculum concentration (bacillus subtilis), temperature and the fermentation duration. P. biglobosa seeds were fermented at various temperature of 40 - ��� ��� �� � � ��� ���� �������� ���� ��� ��� ����������� �� ������� Inoculum. The proximate analysis shows that fermentation increased the percentage protein. Protein had the highest composition with about 51 % after 72 hours at the lowest �� ������ �������� ��� ���������

Extraction of oil from selected plants using Response Surface Methodology [RSM]

This study involves the extraction of oil from three sources: orange peel, guava leaves, and cassia fistula leaves using Soxhlet apparatus. The variables considered in this study were time of extraction and sample weight. Minitab statistical software was used to randomize the runs. The combination of operating parameters that gave the optimum yield for the three sources were identified. The regression equation for each source was reported. The coefficient of determination (R2) value for orange, guava leaves and cassia fistula extract were 99.51%, 99.90%, and 99.77% respectively. This shows that the model is a good prediction tool for extraction of oil from these sources. Based on the R2 values guava leaves (99.90%) gave the highest prediction accuracy followed by Cassia fistula (99.90%), with orange leaves having the lowest R2 value (99.77%) among the three sources considere

Phenomenological Model Development of Percentage Protein Present in Fermented African Locust Beans Seed

The optimum conditions for the fermentation of a local legume known as African locust bean (Parkia biglobosa) into a vegetable protein based food condiment or spice (Iru) were developed using Levenberg-Marquardt (or Powell) method (using PSI software) with three (3) variables namely; inoculum concentration (bacillus subtilis), temperature and the fermentation duration. P. biglobosa seeds were fermented at various temperature of 40 - ��� ��� �� � � ��� ���� �������� ���� ��� ��� ����������� �� ������� Inoculum. The proximate analysis shows that fermentation increased the percentage protein. Protein had the highest composition with about 51 % after 72 hours at the lowest �� ������ �������� ��� ���������