Volume 4, Issue 1, 2016
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- ItemOpen AccessDeformation Behaviour of Led and Hiled Cured Dental Resin Microhybrid and Nanofilled Composites(University of Lagos Press, Akoka, 2016) Adeleye, O.A; Fakinlede, O.A; Ajiboye, J.S; Adegbulugbe, I.CThe deformation behavior of commercial microhybridresin based composite (20/20 composite) and nanofilled composite (Light Cured Universal Composite) cured with the conventional Light Emitting Diode (LED) and exponential Light Emitting Diode (HiLED) under various loading condition have been investigated. Deformation of restorations such as shrinkage and shearing from curing and mastication have been a major concern for clinicians because of void and crack formations in restored tooth structure which affects the mechanical properties of the resin composites. Samples of microhybridresin based composite (20/20 composite) and nanofilled composite (Light Cured Universal Composite) were molded with copper foil molds with standard dimension 2 x 2.5 x 8mm, photo-cured by both conventional Light Emitting Diode (LED) and exponential Light Emitting Diode (HiLED) and then tested on the Electro Force 3200 for their deformation behavior and mechanical properties. Effects of variation of strain rate and curing time were also investigated. The results showed that, out of the four groups of samples studied, microhybridresin based composite (20/20 composite) cured with exponential Light Emitting Diode (HiLED) exhibited highest tensile strength of 28 MPa. The loading and unloading of the samples exhibited hysteresis responses and path dependence nonlinear behavior. At stress values less than 4 MPa, rate dependent recoverable (viscoelasticity) deformation was observed in all the four groups of samples but at stress values beyond 4 MPa rate dependent irrecoverable (viscoplasticity) deformation was observed. Finally, it was observed that increasing curing time leads to increasing tensile strength for materials cured by both methods.
- ItemOpen AccessSonographers Knowledge on the Prevention and Management of Work Related Musculoskeletal Disorders in North Eastern Nigeria(University of Lagos Press, Akoka, 2016) Dlamazira, J; Njoku, G; Okpala, C; Samuel, S.L; Mohammed, SWork-related musculoskeletal disorders (WMSDs) are common among health workers in all ages across all socio-demographic strata of the society and it has significant impact on Sonographers. They are a group of painful disorders of muscles, tendons, and nerves with impact on all aspects of life through pain and by limiting activities of daily living typically by affecting dexterity and mobility. This study is a cross-sectional survey design aimed at determining the knowledge of sonographers on the prevention and management of WMSDs in North Eastern Nigeria. A total of 52 copies of 18 1tem self-administered, structured and pretested questionnaires were distributed to sonographers. Items include demographic information, section on knowledge of prevention and management of WMSDs. The study showed the same result 26(50%) for those who exercise and those who do not exercise in between examination. 29(55.8%) of the respondents do not use height adjustable couch during scanning, 40(76.9%) use finger grip to hold the transducer while 23(12%) do not use finger grip. Majority 41(78%)of the respondents change scanning position between examinations while 22(11%) do not change scanning position between examinations. 48(25%) of the respondents carry out the same examination always while 51(27%) responded no.32(61%) respondents take short but frequent breaks from scanning while 38(20%) did not take breaks. 39(75%) of sonographers take responsibility to address personal work load while 13(25%) do not address personal work load. Sonographers have good knowledge of the prevention and management of WMSDs, however, general awareness and regular trainings are recommended in order to avoid occurrence.
- ItemOpen AccessDominant Pollen in Honey Samples from Four Beehives in Abeokuta, Southwest, Nigeria(University of Lagos Press, Akoka, 2016) Adekanmbi, H.O; Alebiosu, O.SIn the quest to examine the preferentially foraged pollen by honey bees in Abeokuta, Nigeria, a palynological study was conducted on honey samples from four bee farms; Owudekudu, Olorunda, Agbede and Odeda, all situated within Abeokuta, Ogun State, Nigeria. Honey samples were collected and subjected to acetolysis, followed by slide preparation and microscopy of the treated samples. Twelve pollen types were recovered from the four honey samples and some of these pollen are common to the four honeys. A classification method for expressing pollen frequency class was adopted: Very frequent (Over 45%), Frequent (16-45%), Rare (3-15%) and Sporadic (Less than 3%). The most abundantly recovered pollen grains in the four locations were those of Berlinia grandiflora, Albizia sp., Bombax buonopozense, Asteraceae and Fabaceae. Pollen of Elaeis guineensis, Rutaceae, Amaranthaceae, Combretaceae/Melastomaceae, Senna sp., Poaceae and Convolvulaceae were also recovered. The results of this study indicate that these plants were preferentially foraged by honey bees in the sample locations. This might have been influenced by more suitable nutritional contents of these pollen grains produced by their parent plants, although yet to be investigated. Hence, there is need for an appropriate conservation strategy of these plants from destructive human activities such as indiscriminate felling of trees and forest clearing for agricultural and urban developmental projects. The results from this work have established these plants as preferential to bee forage in Nigeria.
- ItemOpen AccessScreening for Eating Disorders among Undergraduate Students in Two Nigerian Higher Institutions(University of Lagos Press, Akoka, 2016) Aina, O.F; Olagunju, A.T; Akinbode, A.A; Suleiman, T.FBackground: Eating disorders are important psychopathologies with associated physical/ mental health complications and mortality. They are common problems in the Western world; however, with only few studies from the Southern part of Africa, they are believed to be rare in the continent, hence this study. Methods: The study was carried out among selected undergraduates of two higher institutions in Lagos, Nigeria. They were administered with Socio-demographic Questionnaire and Eating Attitudes Test- 26-item version (EAT-26). Results: A total of 1054 students in the two institutions were studied, and were made up of 55.6% males and 44.4% females; with mean age of 21.38±3.66 years. The anthropometric indices of the subjects were mean weight of 63.29±11.14kg, mean height was 1.69±0.09 metres, and mean body mass index (BMI) of 22.17±3.58. On assessment with EAT-26, 152 (15.3%) scored ≥20 that is screened positive for eating disorders (N=995). Higher percentage of females screened positive for eating disorders compared to the males with significant difference of X2=19.47 and p=0.000. Conclusion: About one-sixth of the subjects screened positive for eating disorder, which is quite important for our environment erroneously believed to lack cases of eating disorders. Also as obtained in the Western world, eating disorders are more prevalent among the females. With limitation of screening instrument, it is advocated for diagnostic instruments to be employed in future studies.
- ItemOpen AccessDesign and Optimization of a Water Cooled Antenna for Microwave Ablation using Finite Element Method(University of Lagos Press, Akoka, 2016) Adeneye, S.O; Ibitoye, Z.A; Akpochafor, M.O; Aweda, M.A; Ajekigbe, A.TMicrowave ablation is a technique for treating cancerous tissues with the application of heat. Some tumors are located such that they cannot be successfully treated with conventional external radiation beam techniques. Microwave ablation is currently an alternative option being considered for the treatment of unresectable tumors. In this study, we designed a water cooled microwave antenna for tumor ablation. The water cooled antenna for hepatic microwave ablation was designed using Finite Element Methods (FEMs) (COMSOL MULTIPHYSICSTM version 4.4). Finite element methods were used to study the electromagnetic (EM) field and thermal distributions in liver. The water slot position, water slot length and the antenna slot length, from the tip of the antenna (z = 0 mm) were varied within the ranges (43 ≤ z ≤ 60 mm), (1 ≤ z ≤10.5 mm) and (1 ≤ z ≤ 20 mm) at 1 mm, 0.5 mm and 0.5 mm interval respectively, at a frequency of 2.45 GHz. The design has reflection coefficient of -25.5dB, with 94.0% power dissipation into the tissue. Experimental validation shows that the inclusion of a cooling unit reduces the backward heating and increases the power deposition into liver tissue.
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