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Olabode S.O.,Federal University of Technology Akurre
Journal of African Earth Sciences | Year: 2014

Soft sediment deformation structures were recognized in the Maastrichtian shallow marine wave to tide influenced regressive sediments of Ajali Formation in the western flank of Anambra basin, southern Nigerian. The soft sediment deformation structures were in association with cross bedded sands, clay and silt and show different morphological types. Two main types recognised are plastic deformations represented by different types of recumbent folds and injection structure represented by clastic dykes. Other structures in association with the plastic deformation structures include distorted convolute lamination, subsidence lobes, pillars, cusps and sand balls. These structures are interpreted to have been formed by liquefaction and fluidization mechanisms. The driving forces inferred include gravitational instabilities and hydraulic processes. Facies analysis, detailed morphologic study of the soft sediment deformation structures and previous tectonic history of the basin indicate that the main trigger agent for deformation is earthquake shock. The soft sediment deformation structures recognised in the western part of Anambra basin provide a continuous record of the tectonic processes that acted on the regressive Ajali Formation during the Maastrichtian. © 2013 Elsevier Ltd.

Oyetayo O.V.,Federal University of Technology Akurre
African Journal of Traditional, Complementary and Alternative Medicines | Year: 2011

For centuries, mushrooms have been appreciated as sources of food nutrients and pharmacologically important compounds useful in medicine. Yet not all the medicinal properties of mushrooms have been exploited. The above statement is more pertinent to mushrooms that are indigenous to Nigeria. There are inadequate data on the identity and medicinal properties of these wild mushrooms. Information on the ethnomedicinal uses of some mushrooms such as Pleurotus tuber-regium used for headache, stomach pain fever, cold, constipation; Lentinus squarullosus for mumps, heart diseases; Termitomyces microcarpus for gonorrhea; Calvatia cyathiformis for leucorrhea, barreness; Ganoderma lucidum for treating arthritis, neoplasia; G. resinaceum used for hyperglycemia, liver diseases (hepatoprotector); G. applanatum used as antioxidant and for diabetes had been gathered through survey. The above information is mostly obtained from traditional herbalists who in most cases will not disclose their preparation compositions. A lot of these mushrooms are obtained only in the wild. Scientific documents of the identities and medicinal properties are still scanty. Preliminary studies on some species of Temitomyces, Lenzites and Lentinus species showed that they possess appreciable antimicrobial and antioxidant properties. Moreover, molecular characterization also reveals that they are not 100% homologous with existing sequences under the same name in GenBank. It is therefore pertinent that well structured studies on their ecology, identification and medicinal uses be carried out. This will make the full exploitation of the medicinal potentials of mushrooms indigenous to Nigeria realizable.

Oladele E.-O.,Federal University of Technology Akurre
Food Bioscience | Year: 2015

Gelatinisation temperature in excess moisture was determined on plantain starches and flours and the degree of starch gelatinisation in whole cooked foods was deduced. The gelatinisation temperature of plantain starch was determined using an enzymatic method (with confirmation from scanning electron microscopy). Starch gelatinisation temperature for plantain starch was observed at 75±1°C n=3, while it was 80±1°C, n=3, for starch in the flour. The enzymatic digestion method was then applied for the determination of the in vitro degree of starch digestion in ripe and unripe flours of plantain (in situ) at different treatment temperatures, and an attempt was made to deduce the equivalent treatment temperatures of cooked foods from the flours using three equations. One-way anova statistical analysis was used to determine the equation that gave the best fit, which was subsequently used to estimate values for the degree of starch gelatinisation in some cooked plantain foods. Treatment temperatures extrapolated from the equation of best fit ranged between 73.2±0.3-79.5±0.2°C and 67.8±0.5-80.1±1.3°C for ripe and unripe plantain foods respectively. Processing conditions are therefore important in preserving the nutritional quality of starch in plantain. © 2015 Elsevier Ltd. All rights reserved.

Alaneme K.K.,Federal University of Technology Akurre
International Journal of Mechanical and Materials Engineering | Year: 2012

The influence of thermo-mechanical treatment on the percent porosity and mechanical behaviour of SiC reinforced aluminium alloy (6063) composites was investigated. AA 6063 - SiC p composites having 6 and 9 vol. % of SiC were produced by the use of Borax additive and double stir casting process. The composites were cold rolled to 20, 25 and 35% deformation before solution heat-treating at 550°C for 1hour cooling rapidly in water. Density measurements and percent porosity of the composites were evaluated; also their tensile properties and fracture toughness were assessed. The results indicate that the cold rolling and solution heat-treating processes resulted in remarkable reduction in porosity levels in the composites (≤ 1.9% porosity). A good uniform distribution of the SiC particulates in the AA 6063 was also produced. The tensile properties and fracture toughness of the composites improved significantly with the adoption of the cold rolling and solution heat-treatment process.

The fracture behavior of dual phase medium carbon low alloy steels produced using two different chemical compositions (A - 0.34C, 0.75Mn, 0.12Cr, 0.13Ni steel and B - 0.3C, 0.97Mn, 0.15Cr steel) was investigated using circumferential notched tensile (CNT) specimens. Intercritical treatments were performed on samples with composition A by 1) austenitizing at 860 °C for 1 hour cooling in air, then treating at 770 °C for 30 minutes before oil quenching; 2) austenitizing at 860 °C for 1 hour quenching in oil, then treating at 770 °C for 30 minutes before quenching in oil; and 3) austenitizing at 860 °C for 1 hour, super-cooling to 770 °C and then quenching in oil. Samples of composition B were subjected to intercritical treatment at temperatures of 740, 760, and 780 °C for 30 minutes, followed by quenching rapidly in oil. Tensile testing was then performed on specimens without notches and the CNT specimens. It was observed that the dual phase steel produced from procedure (2) yielded a fine distribution of ferrite and martensite which gave the best combination of tensile properties and fracture toughness for composition A while the dual phase structure produced by treating at 760 °C yielded the best combination of tensile properties and fracture toughness for composition B. The fracture toughness results evaluated from the test were found to be valid (in plain strain condition) and a high correlation between the fracture toughness and notch tensile strength was observed. The fracture toughness values were also found to be in close agreement with data available in literature.

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