A comparative study of concrete properties using coconut shell and palm kernel shell as coarse aggregates

The high cost of conventional building materials is a major factor affecting housing delivery in Nigeria. This has necessitated research into alternative materials of construction. This paper presents the results of an investigation carried out on the comparative cost analysis and strength characteristics of concrete produced using crushed, granular coconut and palm kernel shells as substitutes for conventional coarse aggregate in gradation of 0%, 25%, 50%, 75% and 100%. Two mix ratios (1:1:2 and 1:2:4) were used. A total of320 cubes ofsize 100�100�100mm were cast, tested and their physical and mechanical properties determined. The results ofthe tests showed that the compressive strength ofthe concrete decreased as the percentage of the shells increased in the two mix ratios. However, concrete obtained from coconut shells exhibited a higher compressive strength than palm kernel shell concrete in the two mix proportions. The results also indicated cost reduction of 30% and 42% for concrete produced from coconut shells and palm kernel shells, respectively. Considering the strength/economy ratio, it was concluded that coconut shells were more suitable than palm kernel shells when used as substitute for conventional aggregates in concrete production. r 2005 Elsevier Ltd. All rights reserved

Studies on termite hill and lime as partial replacement for cement in plastering

This study investigated the compressive strength and water absorption capacity of 50�50�50mm mortar cubes made from mixes containing lime, termite hill and cement and sand.Two mix ratios (1:4 and 1:6) and varying binder replacements of cement with lime or termite hill amounting to 0%, 10%, 20%, 30%, 40% and 50% were used.Test results showed that the compressive strength of the mortar cubes increases with age and decreases with increasing percentage replacement of cement with lime and termite hill.However, for mix ratio 1:6, up to 20% replacement of cement with either lime or termite hill, all the mortar cubes had the same strength; subsequently, the termite hill exhibited a higher compressive strength.For mix ratio 1:4, mortar cubes made from lime/cement and termite hill/cement mixtures had the same strength at 50% replacement.Generally, water absorption is higher in mixtures containing lime (18.10% and 14.20% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level) than those containing termite hill (16.10% and 13.02% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level). Termite hills seem to be promising as a suitable, locally available housing material for plastering. r 2005 Elsevier Ltd.All rights reserved

A Study of Awareness and Electricity Use Behaviour of On-campus Residence Students in Nigeria

The study explored the awareness and reported energy use behaviour among higher education students in Southwestern Nigeria; examined the relationship between the level of awareness of the impact of energy use behaviour of students and also provides strategies that could be used to improve the level of awareness of stakeholders. We adopted a quantitative survey and questionnaire as instruments for gathering relevant data from end users in the study area and relevant data were analysed using descriptive statistics. The findings revealed that end users had low level of awareness of the negative impact of energy use behaviour 201(81.4%) and had not been trained on energy saving measures. However, they were more aware of the positive impact of energy use behaviour 194(79.0%). The analysis also showed a significant relationship between awareness and reported energy use behaviour; awareness level and turning off light when not needed (r = 0.897, p = 0.001), awareness level and shutting down all computers unless in use (r = 0.189, p = 0.044) and awareness level and leaving computer running overnight (r = 0.452, p = 0.003). The study concluded that the level of awareness of energy saving measures of electricity end users was very low and consequently a lot of energy could be wasted in return. To maximize energy saving potentials of the students, there is need for authorities in tertiary institutions to make effort to raise the awareness of everyone involved; including the management of institutions through an energy efficiency awareness programme, as this could help higher education institutions to achieve energy sustainability and reduce waste. The study developed a framework for improving and enhancing students’ awareness on the impact of energy use behaviour

Power System’s Voltage Stability Improvement Using Static Var Compensator

In alternating current systems, voltage fluctuation is a common phenomenon. Most of the voltage fluctuation problems result from the changes in the system’s reactive power resulting from excessive supply or consumption of reactive power by the elements of the system and the variation in the consumers’ loads. In this paper, the effect of Static Var Compensator (SVC) in stabilizing power system’s voltage through effective reactive power compensation was investigated. Power flow equations involving voltage drop with/without SVC were developed. SVC modeling equations were also developed and used to determine its parameters. Based on the SVC parameters, SIMULINK blocks were used to implement the phase controlled Thyristor–Controlled-Reactor Fixed-Capacitor (TCR-FC) SVC. The Nigerian 28-bus power system used for the study was also modeled using SIMULINK/MATLAB. The 28-bus system was first simulated without SVC and then with two SVCs located at different buses to obtain the bus voltages in both cases. From the bus voltages the total voltage drops for the system with and without SVC were estimated and compared. The compared results clearly showed that, the system’s voltage drop was reduced by 33.78% indicating a significant improvement in the system’s voltage stability when SVCs were applied

BASIC ANALYTICAL EXAMINATION OF SELECTED STREAMS AND THEIR WATER QUALITY IN ADO-EKITI (SOUTHWESTERN NIGERIA) AND ITS NEIGHBOURING VILLAGES.

Water samples were collected from ten (10) streams at different locations within Ado-Ekiti and its environ in Ekiti State, South Western Nigeria. The samples were evaluated for their physico-chemical properties. The samples under investigation has pH within the range 7.6 to 8.2; total hardness 8.0 mg/l to 196.0 mg/l; Calcium and Magnesium hardness 1.6 mg/l to 76.0 mg/l and 0.49 mg/l to 19.93 mg/l respectively; total solids 0.2 mg/l to 1.2 mg/l; total suspended and total dissolved solids 0.00 to 0.06 mg/l, 0.14 mg/l to 1.16 mg/l respectively; free carbondioxde 3.74 × 10-3 mg/l to 5.72 × 10-3 mg/l; phenolphthalein acidity 9.0 mg/l to 15.0 mg/l; conductivity 4.0 μScm-1 to 570 μScm-1. The metal analysis results from atomic absorption spectroscopy (AAS) are as follows: Sodium (2.7 mg/l to 60.1 mg/l), Potassium (4.0 mg/l to 52.0 mg/l), Zinc (0.80 mg/l to 1.51 mg/l), Calcium (1.60 mg/l to 76.0 mg/l), Iron and Lead were not detected in the sample considered

Investigative study of seasonal changes in Quality Parameters of Oluwa River Water, Agbabu area of Nigeria

Physico-chemical parameters of River Oluwa water in Agbabu, Nigeria were investigated to determine its quality characteristics and establish seasonal effects on the water. Water from the river was collected at five different points in dry season (March, 2008 and 2009) and rainy season (July, 2008 and 2009). Insitu parameters (pH, EC and Turbidity) were measured using Horiba Water Checker Model U-10 while TDS was by Lovibond CM – 21 Tintometer. Subsequently in the Laboratory, Na+ and K+ were determined using flame photometric methods while Ca2+, Mg2+, HCO3-, SO42-, Cl-, PO42- and NO3- were determined by wet analysis. River Oluwa water was alkaline with average pH of 7.41 and 7.53 in dry and rainy seasons respectively. Electrical conductivity (EC) was high during dry season (av. 630.44 µS/cm), but low in the rainy season (av. 317.58 µS/cm) due to long residence time in dry season allowing more water-rock interaction. Turbidity's average values of 0.14 NTU and 2.29 NTU in dry and rainy seasons respectively suggested moderate pollution with particulate matter. The order of average cations concentrations in the dry and rainy seasons was Ca2+ K+ Na+ Mg2+ while that of the anions was HCO3- Cl- SO42- NO3-. The ions concentrations though lower in rainy season, Ca2+-HCO3- water was dominant in both seasons. Quality evaluation for irrigation revealed that the water was suitable for all irrigation purposes. River Oluwa water was soft, low mineralized, chemically potable, suitable for irrigation but with lower ionic concentrations in rainy season

Factors Affecting Effective use of Safety Wears among Construction Site Operatives: Lessons from Indigenous Firms in South Western Nigeria

Work related hazard is not a new phenomenon but its frequent occurrence on sites remain a major setback towards successful projects delivery. The study assessed factors affecting effective use of safety wears on construction sites. Based on snowball and random sampling technique, 128 copies of questionnaire were administered to participants with years of experience on construction management. The outcome of the study revealed that the top aspect of safety practices currently explored by the indigenous construction firms on sites include: provision of temporary fence, provision of accidents prevention procedure and development and frequently review of Safety Policy for building projects. The result of Independent Samples T-test showed the top three factors preventing effective use of safety wears on construction sites are: inadequate engagement of Safety Managers on sites, lack of proper training on effective use of safety wears and workers failure to adapt with safety practices as it was against their traditional training. This paper concluded that effective use of audio and visual displaying gadgets on site, conducting in-house safety training for the workers and ensure one Safety Manager is employ on every construction sites will go a long way in improving workers safety practices on sites

Biodegradation of Waste Papers: A Sustainable Technology for a Clean Environment

Solid wastes have posed problems of pollution in both developed and developing countries where they are found in large quantities due to domestic and industrial utilization of such materials, the inability to recycle all wastes has provided the nudging to delve into alternative method of waste management. This project aims at analyzing the effect of fungi metabolites (Enzyme); (Rhizopus) in the bioconversion of waste papers (Foolscap, Newspaper and Brown envelop) into fermentable or reducing sugars. Proximate analysis, alkaline pretreatment with sodium hydroxide and process of deinking for the removal of inks for higher susceptibility of the substrate were carried out on paper samples. Hydrolysis using enzyme was carried out for 7 days. Concentration of reducing sugar present in the samples was done using the Dinitrosalicylic acid test method. Effects of Temperature on the waste sample were analyzed at 37, 40 and 45°C

Development of a novel UPLC-MS/MS-based platform to quantify amines, amino acids and methylarginines for applications in human disease phenotyping

Amine quantification is an important strategy in patient stratification and personalised medicine. This is because amines, including amino acids and methylarginines impact on many homeostatic processes. One important pathway regulated by amine levels is nitric oxide synthase (NOS). NOS is regulated by levels of (i) the substrate, arginine, (ii) amino acids which cycle with arginine and (iii) methylarginine inhibitors of NOS. However, biomarker research in this area is hindered by the lack of a unified analytical platform. Thus, the development of a common metabolomics platform, where a wide range of amino acids and methylarginines can be measured constitutes an important unmet need. Here we report a novel high-throughput ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) platform where ≈40 amine analytes, including arginine and methylarginines can be detected and quantified on a molar basis, in a single sample of human plasma. To validate the platform and to generate biomarkers, human plasma from a well-defined cohort of patients before and after coronary artery bypass surgery, who developed systemic inflammatory response syndrome (SIRS), were analysed. Bypass surgery with SIRS significantly altered 26 amine analytes, including arginine and ADMA. Consequently, pathway analysis revealed significant changes in a range of pathways including those associated with NOS

Human and preclinical studies of the host-gut microbiome co-metabolite hippurate as a marker and mediator of metabolic health.

OBJECTIVE: Gut microbial products are involved in regulation of host metabolism. In human and experimental studies, we explored the potential role of hippurate, a hepatic phase 2 conjugation product of microbial benzoate, as a marker and mediator of metabolic health. DESIGN: In 271 middle-aged non-diabetic Danish individuals, who were stratified on habitual dietary intake, we applied 1H-nuclear magnetic resonance (NMR) spectroscopy of urine samples and shotgun-sequencing-based metagenomics of the gut microbiome to explore links between the urine level of hippurate, measures of the gut microbiome, dietary fat and markers of metabolic health. In mechanistic experiments with chronic subcutaneous infusion of hippurate to high-fat-diet-fed obese mice, we tested for causality between hippurate and metabolic phenotypes. RESULTS: In the human study, we showed that urine hippurate positively associates with microbial gene richness and functional modules for microbial benzoate biosynthetic pathways, one of which is less prevalent in the Bacteroides 2 enterotype compared with Ruminococcaceae or Prevotella enterotypes. Through dietary stratification, we identify a subset of study participants consuming a diet rich in saturated fat in which urine hippurate concentration, independently of gene richness, accounts for links with metabolic health. In the high-fat-fed mice experiments, we demonstrate causality through chronic infusion of hippurate (20 nmol/day) resulting in improved glucose tolerance and enhanced insulin secretion. CONCLUSION: Our human and experimental studies show that a high urine hippurate concentration is a general marker of metabolic health, and in the context of obesity induced by high-fat diets, hippurate contributes to metabolic improvements, highlighting its potential as a mediator of metabolic health