The need to provide an alternative to other set time retarders, preventing cold joints in concreting, eliminating the need for constant vibration which might lead to loss of consistency and also offset the effect of high down hole temperature motivated this research. Therefore, the aim of this work is to investigate the effect of sugar on the set time on ordinary Portland cement (OPC) concrete considering the fact that sugar is readily available and at lower cost compared to other known retarders. The effects of sugar at concentrations of 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.07, 0.09. 0.25, 0.30, 0.40, 0.45, 0.50 and 1.0 % by weight of cement on cement paste and its strength at 28 days was investigated. The setting time of the cement was found to increase from 121, 154, 220, 262, 282, 309, 342, 328, 128, 78, 68, 53, 40 minutes when the sugar content was varied from 0 % sugar content to 0.5 % sugar content respectively. Peak time was attained at 0.07% sugar content where a time of 342 minutes delay in set was recorded. Steady decline starts at 0.09 % sugar content and flash setting comes in between 0.25 and 0.5 %. The compressive strength test also showed slight strength gains with peaks at 0.02 % and 0.07 % where its load bearing capacity was determined to be 533 and 470 kN respectively. Thus, sugar can be used as a setting time retarder since its action does not amount to a loss in strength of the tested samples.
The ability of tidal power to reliably contribute energy to electricity networks is directly related to the characteristics of the tidal resource. This research presents an investigation on the tidal energy potential of Calabar, Cross-River State (Latitude 4.9667°N, Longitude 8.3167° E) a coastal region of Nigeria along the Atlantic Ocean. An analysis of the characteristics of the tidal power resource of Calabar in Southern Nigeria has been carried out, based on daily observed tidal height for the period of ten years (2001 – 2010). Patterns of tides availability are presented, with data demonstrating distinct patterns of daily, monthly and yearly variability – tides exhibited a sinusoidal trend over the ten-year period. The average yearly tidal height range of Calabar was 2.65 – 3.02 meters.
Nigerian oil and gas drilling operations are highly depended on the imported bentonite for use as drilling fluid. The importation drains the nation’s foreign reserve despite the fact that the country is equally blessed with huge deposit of this natural resource even though of inferior quality. This research characterized the Warsale montmorillonite clay from Dikwa formation. The clay was beneficiated (wet and dry) using Na2CO3 and the beneficiated drilling muds formulated. Drilling fluids formulated from the beneficiated clay did not possess the minimum rheological properties for use in oil and gas drilling operations. However, an improvement in rheological and filtration properties was observed when beneficiated with Na2CO3 and treated with CMC. The optimum values for plastic viscosity and gel strength were obtained at 6-10%wt Na2CO3 concentrations. The fluid loss of muds from Warsale bentonite was improved by about 50% when treated with Carboxy-Methyl-Cellulose (CMC) and meets the API requirements. The pH and sand content of the muds also fall within the API standards. The rheological and filtration properties of the local clay were found to be inferior to the reference Wyoming bentonite due to low concentrations of smectites and high levels of contaminants in the compositions of the local clays. However, this study shows that given the proper conditioning, beneficiated Warsale clay will give a good promise for drilling purposes at optimum sodium carbonate and additives concentrations.
Cloves ( Syzygium aromaticum L.) are the aromatic dried flower buds of a tree in the family Myrtacae. Clove's essential oil is widely used as aromatherapy and for toothache treatment. Development of extraction technology that could increase oil yield from clove would thus significantly enhance the profitability of the clove's oil and reduce processing costs significantly. In this research work an essential oil was obtained from using Sohxlet and an ultrasonic-assisted extraction methods with n-hexane as extraction solvent. The oil extract was analyzed for its chemical composition using gas chromatography/mass spectrometric (GC-MS). The results of analysis show that the essentialoil yield were found to be 54.70% and 71.55% while the eugenyl acetatein extracts obtained were found to be 5.72% and 9.24% for sohxlet and ultrasonic-assisted extraction methods respectively.
This research investigated the study on the coagulation of bakery waste water using bambara nut husk. It equally studied the effect of process parameters like temperature (30-360C), time (10-50mins), coagulant concentration (400-1000mg/l) and pH (2-8) on the total suspended solid content (TSS) of the bakery waste water. Proximate analysis of the coagulant and characterisation of the bakery wastewater were done. The coagulation study was done using the jar test method based on standard bench scale Nephlometric method for the examination of water and wastewater. It was observed that increase in temperature did not favour the coagulation process. Increase in time from 10 to 50mins decreased the TSS of the wastewater. Increase in coagulant concentration from 400-800mg/l decreased the TSS of the wastewater, but further increase to 1000mg/l increased the TSS. Increase in pH from 2-6 decreased the TSS, but further increase to 8 increased it. Characterisation of the wastewater after the coagulation shows that lead and nitrate were completely removed after the treatment, while chemical oxygen demand and biological oxygen demand were reduced. It was equally observed that dissolved oxygen which was 22.5mg/l before the treatment was increased to 55.1mg/l after the treatment.
A study of seed development and maturation in edible bean (Phaseolus vulgaris L.) was conducted on field-grown plants. The main objective of this present research was to investigate the physico-functional (bulk and true densities of the flour; hydration capacity, hydration coefficient, hydration index, swelling capacity, swelling coefficient, swelling index, moisture uptake, electrical conductivity and pH) properties of bean seeds during maturity, in view of designing necessary processing and handling equipment, and formulation of complementary foods. Physico-functional properties of three bean varieties (iron, honey and butter brown) were evaluated in three maturity stages of 14, 21, and 28 days after peak anthesis (DAPA). Results of the study showed large variability in all the physico-functional properties of the three bean varieties during maturation. There were significant (P ≤0.05) differences among selected seed lots in most of the parameters, and maximum seed functional quality was recorded at 28 DAPA. As maturation increased from 14 DAPA to 28 DAPA for the iron, honey and butter brown bean seeds, the hydration capacity increased from 0.230 to 0.469 (g/seed), 0.108 to 0.253 (g/seed) and 0.101 to 0.244 (g/seed). Hydration coefficient increased from 1.86 to 2.043%, 1.77 to 1.93% and 1.71 to 1.91%. Hydration index increased from 0.029 to 0.027, 0.026 to 0.109 and 0.024 to 0.109. Swelling coefficient increased from 1.4 to 1.74%, 1.91 to 2.65% and 2.167 to 3.125%; while the swelling index increased from 0.013 to 0.025, 0.031 to 0.053 and 0.038 to 0.071. Conclusively, the three bean varieties investigated have great potential as functional agents in the food processing industries. The results of this study are expected to be useful for plant breeders, consumers, and the food processors.
The effect of drying on rheological properties of yam flours was studied. Five varieties of yam flours namely white yam (Dioscrea rotundata), Three leave yam (Dioscorea dumetorum), purple yam (Dioscorea aalata) Water yam (Dioscorea alata), yellow yam (Dioscorea cayenensis) dried under three drying methods(oven, solar and sun drying methods) were used for the study. Results revealed that white yam, purple yam, three leave yam, water yam and yellow yam recorded viscosity ranges of 80 – 275kpa, 125 – 437kpa, 155 – 468kpa,89 – 563kpa and 113 – 471kpa respectively. In the same order, under sun, the yam varieties had viscosity range of 179 –349kpa,156 – 329kpa, 176 -416kpa, 83 – 233kpa, and 85 – 176kpa while under solar drying method white yam had viscosity range of 133 – 263kpa, purple yam, three leave yam, water yam and yellow recorded 184 – 442kpa, 204 -518kpa, 115 – 236kpa, and 95 – 274kpa respectively. The viscosity obtained for the yam varieties under different drying methods shows that their flours could be use as stabilizers or modifiers to enhance product in food industry. The analysis of variance on the effect of drying temperature and drying method on pasting behaviour of yam varieties showed no significant different at 5% level of probability for the drying temperature while there is significant difference in the drying methods of the yam varieties (p > 0.05).Five percent (5%) level of probability is a specified ἀ or p – value at which the significance of a given null hypothesis is adjudged after statistical analysis.
Waste palm oil (WPO) has proved to be a source of feedstock for producing biodiesel using the transesterification method. In this work, WPO collected from restaurants were converted to biodiesel using transesterification method. The effects of temperatures varying from 45 to 65OC, mixing speeds varying from 600 to 1000rpm and time of reaction varying from 45 to 120 minutes with catalyst concentration of 1.6% weight of the WPO sample and methanol to oil ratio of 6:1 were studied to determine waste palm oil biodiesel (WPB100) yield. The experiment was designed using Central Composite Design of Design Expect software (6.0.6 version) and analysed using response surface methodology (RSM) showed optimal biodiesel yield of 94% at the combinations of 59.80C reaction temperature, 103.15minutes time of reaction and 874.91rpm mixing speed. The quadratic model developed with the software indicated R-square value of 0.9690 which implies strong correlation between the experimental and predicted yields. Also, amongst the varied variables, temperature of operation had the highest significant impact on yield whereas the interaction between temperature of reaction and mixing speed had least impact. The cetane number (CN), calorific value (CV), density, kinematic viscosity (KV), and moisture content (M.C) of the biodiesel produced were 57, 40.56MJ/kg, 0.88g/mL, 5.2mm2/sec and 0.03% respectively which are within American Standard for Testing Material (ASTM) for biodiesel. The work concluded that reaction temperature and time of operation are more impactful on biodiesel yield than mixing speed. The quadratic model fitted by Design Expect statistical software successfully predicted the expected yield.
Several models have been proposed for modelling the lifetime data for reliability analysis. The performances of these models have been evaluated by fitting the models with the datasets and then compare the value with the values of the existing models. This study proposed a new model that enhance the modelling of data in reliability studies and the performance of this proposed model was evaluated by comparing it with others related models, these models include Weibull-Burr type X, Exponentiated Generalized-Burr type X and Burr type X model. The Akaike information criterion (AIC) of each model was calculated using the dataset contained about 30 units of observations. Results show that the AIC of the proposed model was found to be 10.00 while the AIC of the other three competitive related models are 192.34, 367.45 and 367.87. The result of the analysis revealed that the proposed model (Generalized Transmuted-Generalized Rayleigh) with smallest AIC had the best performance when compared to the other three competitive related models, hence the model can better be used in reliability analysis as well as in analysing skewed datasets.
Bio-degradable materials have been studied in many literature as a potential replacement for metallic and synthetic materials in view of the emerging environmental concerns. Part of its acclaimed advantage is its tendency to evolve cleaner climate and provide safe haven for future generations. The introduction of bio-fibre in many engineering applications is becoming popular as witnessed in the automotive component parts replacement and other useful area of engineering application. With the increasing integration of bio-fibre in composite formation, it is crystal clear that the availability of natural fibre for various engineering application may be hindered as a result of its declining production. In this paper, attempts were made to access the level of production of bio-fibre taking into consideration its competitive demand in climate mitigation. Part of the discussion in this work analysed the existing literature production volume of bio-fibre and the cellulose, lignin content in fibre as it constitutes mechanical and chemical barriers against pathogens. It is expected that this research work will project the broad impact of bio-fibres and proffer its better utilization options. Key of the conclusions drawn in this work reinforces the need to conserve natural fibres in the face of competitive demands.
The Editor in Chief, Journal of Experimental Research Department of Anatomy, Enugu State University of Science and Technology, College Of Medicine (ESUCOM), GRA Enugu, Nigeria.
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Enugu State University of Science and Technology