Browsing Volume 4, Issue 2, 2016 by Title
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- ItemOpen AccessCorrosion Characteristics of Rebar and Fibre Reinforced Concretes in Selected Environments(University of Lagos Press, Akoka, 2017) Amuda, M.O; Ameh, D; Salako, O.A; Adeyemi, O.OThe corrosion characteristics of rebar and fibres reinforced concretes in selected aggressive environments were investigated. Steel rebar and different fibre materials consisting of steel fibre, coconut fibre, glass fibre, and polymer fibre were used as reinforcements. Corrosion characteristics of these reinforced concretes were evaluated using visual inspection, compressive strength test and accelerated impressed current technique in 3.5wt% NaCl. Analysis of the results indicated that concrete reinforced with polymer and steel fibres after corrosion exposure exhibited lower reduction in compressive strength at 10%, 17%, respectively compared to conventional rebar concrete which had a loss of about 20% across the selected environments; whereas strength loss averaged 44% and 28% in concretes reinforced with coconut and glass fibres, respectively. The findings from this investigation suggested that steel and/or polymer fibres are suitable substitute for rebar in reinforcing concrete.
- ItemOpen AccessDevelopment and Evaluation of a New Instrument to Quantify the Deep Tendon Reflex in the Adult and Elderly(University of Lagos Press, Akoka, 2016)Introduction: Deep tendon reflex (DTR) is routinely used to evaluate the nervous system. Majority of the available devices to measure DTR response are not easily accessible, highly cumbersome, and capital intensive. This study sought to develop and evaluate a less cumbersome, cost effective and easily accessible instrument that can objectively quantify DTR. Materials and Methods: A simple DTR device was fabricated and then evaluated. A total of 74apparently healthy individuals and five hemiplegic patients participated in this cross-sectional analytical study. Hemiplegic participants were to determine the criterion-related validity of the device. Of the apparently healthy participants, 69were assigned into three groups according to their age. Angle of knee excursion (patellar DTR response) was measured using the newly developed DTR device. Jendrassik maneuver was introduced in participants who failed to respond to the initial patellar tendon tapping.Pearson correlation was used to determine relationship between variables at P <0.05. Result: The device demonstrated good face and criterion-related validity coupled with high test-retest and inter-rater reliability with coefficient of 0.74 and 0.86 respectively. There was no significant difference between the patellar tendon response for the right and left lower limbs.(p>0.05).Similarly, sex and age has no significant effect on the patellar tendon reflex response respectively (p>0.05). Conclusion: The newly developed instrument is less expensive and less cumbersome, and was found to be valid. Findings of the study are comparable with previous study that age, sex, and handedness had no significant effects on DTR response. It is therefore recommended for the use of clinicians.
- ItemOpen AccessEffects of reinforcement Particle Sizes on Mechanical Properties of Aluminium/Egg Shell Composites(University of Lagos Press, Akoka, 2016) Agunsoye, J.O; Bello, S.A; Yekinni, A.A; Raheem, I.A; Awe, O.IThe 100 and 150 μm sized CaCO3 particles (sourced from eggshells) from 2-12 wt.% by were used as reinforcements for the fabrication of Al ceramics composites using compo cast technique. The technique involves manual stirring of Al alloy melt-CaCO3 particle mixture prior to pouring process. The morphology of the CaCO3 particles and Al alloy/CaCO3 composites were examined using scanning electron microscope (SEM). The mechanical properties of the fabricated Al alloy / CaCO3 composites were investigated. The result obtained from SEM analysis revealed that the microstructures of Al alloy/100 μm CaCO3 composites are finer than those of their counterparts. This justifies better interaction of 100 μm with Al alloy than 150 μm CaCO3 particles which may be attributable to particle diffusion enhancement due to a decrease in the particle size. Al alloy/100 μm CaCO3 composites displayed higher tensile strain than Al alloy/150 μm CaCO3 composites. Hence the use of 100 μm sized egg shell particles for reinforcement has experimental proven advantages over 150 μm sized CaCO3 particles. Keywords:
- ItemOpen AccessThe Effects of Resin Matrix Composition, Filler Volume and Particle Size on the Mechanical Properties of Dental Resin Composites(University of Lagos Press, Akoka, 2016) Adeleye, O.A; Fakinlede, O.A; Makinde, J.TThe behaviour of dental resin composites (DRC’s) under mechanical loading has been of concern in dentistry as it determines their clinical application. The aim of this study is therefore to check the effect of the resin matrix composition, filler volume and particle size on the mechanical properties of DRC’s. In this experimental in-vitro study, six types of composite resins were used as follows: Two(2) Micro hybrid- Super Cor (SC) and Natural look(NL); Two(2) hybrid- Alpha dent (AD) and Henry Schein (HS) and two(2) Nano hybrid- i-Xcite(IX) and Fusion(FS),each with varying resin matrix composition, filler volume and particle size. Samples were prepared in aluminum molds and light cured using Optilight Max GNATUS light curing unit at constant time intervals of 20 seconds as specified in literature and designed by curing light manufacturers. The specimens were stored in distilled water at 37°C for 48 hours. Subsequently, the specimens were subjected to tensile test and three point loading using the BOSE Electro Force 3200 system at cross head speed of 1.0mm/min and varying speed of 0.5, 2.0 and 5.0mm/min. Henry Schein 20/20 (hybrid;bis-GMA;56%) exhibited flexural strength of 17MPa but tensile strength of 29.7MPa amongst the group. i-Xcite (nanohybrid; bis-GMA,TEGDMA,UDMA;76.5%) showed the flexural strength of 138MPa and relatively low tensile strength of 25.3MPa. All resin types showed increasing flexural strength with increasing strain rate. Tensile and Flexural strength are dependent on the resin matrix composition, the filler particle size and then the filler volume in that order. Keywords:
- ItemOpen AccessEvaluation of Industrial Discharge Point Source Pollution in Ikeja Industrial Estate, Ikeja, Nigeria(University of Lagos Press, Akoka, 2016) Adesuyi, A.A; Nnodu, V.C; Njoku, K.L; Jolaoso, A.OThe rate of water pollution resulting from industrial effluents is on the increase in Nigeria. This study assessed the physico-chemical and heavy metal parameters from waste water and sediment samples from drainage discharge point of brewery, textile, paints, confectionary, and fibre-cement roof industries in Ikeja Industrial Estate, Lagos in dry and wet seasons. The samples were evaluated for their quality and the data obtained were compared with local and international regulatory standards. Among the parameters determined were colour, pH, temperature, electrical conductivity, total dissolved solid, biological oxygen demand (BOD), chemical oxygen demand (COD), chloride, sulphate, and phosphates using standard methods and procedures. The levels of heavy metals in the water and sediment samples were determined using atomic absorption spectrophotometer (AAS). The values of pH, temperature, BOD, COD, and orthophosphate –P in the water samples were higher than the NESREA limit. Results of analysis of variance (ANOVA) revealed that there was no seasonal significance difference in water and sediment samples (p > 0.05) in all the sampling points. The concentrations of Cd, Cu, Pb, Cr, Zn and Ni in water and sediment samples were higher than the NESREA standards in one or two sampling points along the drainage system. This study revealed that some of these industries still discharge untreated or partially treated waste water into the environment through the drainage system. There is need for regular monitoring and compliance enforcement by appropriate Government Regulatory Agencies on regulatory requirements.
- ItemOpen AccessAn Evaluation of the Analgesic Action of Aqueous Leaves Extract of hybanthus enneaspermus linn.F.Muell [Violaceae] in Rodents(University of Lagos Press, Akoka, 2016) Aigbe, F.R; Ameh, D; Salako, O.A; Adeyemi, O.OHybanthus enneaspermus is a tropical and subtropical shrub used to manage conditions involving inflammation and pain. This study was carried out to evaluate the analgesic activity of aqueous leaves extract of H. enneaspermus (ALHE). The analgesic activity of ALHE (50, 100 and 200 mg/kg) was investigated using acetic acid- and acetylcholine-induced mouse writhing tests, formalin-induced pain and tail clip tests in mice. Naloxone, glibenclamide or pilocarpine was administered to some animals 30 minutes before ALHE prior to induction of pain. Possible contribution of central nervous system (CNS) activity of the extract to its analgesic action was also evaluated using open field and hexobarbitone-induced sleep tests. The extract (50-200 mg/kg) significantly inhibited writhing in the acetic acid- and acetylcholine-induced mouse writhing tests. It was most effective at 100 mg/kg, producing 97.6% and 96.5% inhibition in both tests respectively. Naloxone, glibenclamide and pilocarpine significantly (p<0.001) altered this analgesic effect of the extract. The extract also significantly (p<0.001) increased pain threshold in tail clip test and significantly reduced reaction time in both phases of the formalin-induced pain test. The extract significantly reduced locomotive and exploratory activities of mice in the open field test but did not produce any significant effect in the hexobarbitone-induced sleep test in mice. These findings show that the aqueous leaves extract of Hybanthus enneaspermus possesses analgesic activity, which is mediated by mechanisms likened to those of opioid receptor antagonists, muscarinic receptor antagonists, and K+ channels opening. Keywords:
- ItemOpen AccessEvaluation of Work Posture and Prevalence of Musculoskeletal Disorders among Dentists in Lagos State(University of Lagos Press, Akoka, 2016) Okodugha, O.J; Umesi, D.C; Okafor, U.A; Odebiyi, D.ODentists spend their work hours performing extremely precise procedures in a small space (the patients’ mouth), and dental work is typically characterized by postures with different degrees of distortion, prolonged static postures, repetitive movements, inadequate lighting, and vibrations. This study was designed to evaluate work posture and prevalence of work-related musculoskeletal disorders (WMSDs) among dentists in Lagos State, Nigeria. A total of 47 practicing dentists (males = 25, females = 22) from two Teaching Hospitals within Lagos state, Nigeria participated in this cross-sectional study. Participants were required to complete a standard Nordic musculoskeletal questionnaire; thereafter their work posture was evaluated using Rapid Entire Body Assessment (REBA) tool. Chi-Square statistic was used to determine association among prevalence of WMSDs, REBA scores and anthropometrics. Prevalence of WMSDs was 66.0%, with the low-back having the highest prevalence (51.1%). REBA scores indicated that most respondents (46.8%) were at Medium risk exposure to WMSDs. There was a significant association (p=0.025) between REBA scores and years of working experience; however there was no significant association (p=0.064) between REBA scores and the report of WMSDs. Work-related musculoskeletal disorder, particularly low back pain, was a common problem among dentists. Awkward postures and sustained contractions can be contributory factors to these disorders. Therefore, interventions such as education on proper work posture, use of personal protective equipment (PPE) such as wrist support, back belt and vibration attenuation gloves, and work-station ergonomics may be essential to reduce risk factors.
- ItemOpen AccessKnowledge and Perceived Barriers in the Application of Evidence based Medicalradiography in North Eastern Nigeria(University of Lagos Press, Akoka, 2016) Dlama, Z.J; Samuel, S.L; Abubakar, M; Goni, M; Itopa, R; Mohammed, U.SEvidence Based Medical Radiography (EBMR) is the conscientious and explicit use of information based on the combination of clinical expertise and the best available research evidence and resources available. This study is a survey design aimed at evaluating the knowledge and perceived barriers of Radiographers in the application of Evidence Based Medical Radiography. Forty (40) questionnaires were administered among Radiographers practicing in various states in North Eastern Nigeria out of which 32 (80%) were retrieved. The participants were required to fill a 20 item, self-administered and pretested questionnaires comprising of two sections with questions on demographic data, knowledge, and barriers to the application of EBMR among radiographers. The respondents were between 20 and 56 years, majority were between 26-30 years 56.3%, while 6.3% had the least response.87.5% were males while 12.5% were females. The location of respondents were Yobe15.6%, Gombe 21.9%, Bauchi 9.4%, Adamawa 6.3% and Borno 46.9%.Respondents qualifications were 3.12% Diploma, 90.62%Bachelor’s degree while 6.25% had Master’s degree. 87.5% had good knowledge of EBMR and apply it in practice while 46.9% considered lack of ready access to EBMR resources as important barriers to the use of EBMR in clinical practice. The study showed that radiographers practicing in North Eastern Nigeria had good knowledge of evidence based medical radiography.
- ItemOpen AccessLiquid Chromatographic Technique for the Simultaneous Determination of Sulphamethoxazole and Trimethoprim in Pharmaceutical Formulations(University of Lagos Press, Akoka, 2016) Olusegun, A.O; Hamed, N.C; Olajire, M; Oladipo, O.JThis paper describes the development and validation of a simple, specific, precise, and accurate Liquid Chromatographic method for the simultaneous determination of sulphamethoxazole and trimethoprim in pharmaceutical dosage forms. The chromatographic resolution was achieved with 50mM sodium phosphate buffer and acetonitrile (85:15) on a reversed phase column - Octyldecylsilane C18 column (100 x 4.6 mm, i.d., 5μm) - at ambient temperature. The flow rate through the column was 1ml/min and the UV detection was at 260nm using Agilent HPLC 1100LC System. The mean retention times for trimethoprim and sulphamethoxazole were 2.998 and 6.205 minutes respectively. Calibration curves were rectilinear over the ranges 5–80 mg/L (trimethoprim) and 25–400 mg/L (sulphamethoxazole). The RSD was less than 2.61% and percentage recovery was between91.93% - 103.98% with respect to precision and accuracy. The method has been used to analyze brands of cotrimoxazole tablets. The percentage content of sulphamethoxazole and trimethoprim were found to be comparable with BP 2002 requirement. This method, which has a fair run time of 6 minutes, is cost effective for routine analytical work and for quality control and product monitoring. Keywords:
- ItemOpen AccessPhysico-Mechanical and Thermal Properties of Insulating Refractory Bricks Developed from Ikorodu and Osiele Fireclays and Agroforestry Wastes(University of Lagos Press, Akoka, 2016) Obidiegwu, E.O; Esezobor, D.E; Bodude, M.A; Lawal, G.IThis paper studies the physico-mechanical and thermal properties of insulating refractory bricks developed from selected Nigerian fireclays and agroforestry wastes. The as-received clays and agroforestry wastes were air dried, crushed and ground. Refractory bricks were produced with various weight percentage (60 - 95 %) of clay and (5 - 40 %) of agroforestry wastes and fired at temperature ranging from (950 – 1200oC). The bricks were characterized in accordance with ASTM standards to determine their chemical constituents, physical, mechanical and thermal properties. The microstructural examination of the bricks was carried out using Scanning Electron Microscope. The cost benefit analysis was also conducted. The results of the chemical analysis revealed that the major chemical constituent in the clays were silica (>45%) and alumina (>36%). The sawdust is more carbonaceous in nature with Loss on ignition (L.O.I 97.15) than both rice husk (43.30) and coconut shell (93.47). The porosity of the insulating brick increases from 26.51 - 84.6% as the volume of waste increases from 0 - 35%.The larger the pores (26.51 - 84.6%), the lower the strength (10,000 – 2,239.06kN/m2). The high degree of porosity enhanced the thermal insulating property (0.046 W/mK) of the refractory bricks. The cost benefit analysis carried out revealed that the price of the developed bricks (N261-265) are far lower than the cost of imported bricks. The economic savings is approximately 57 % per unit brick.
- ItemOpen AccessTable of Content(2016) Journal of Medicine, Science & Technology