Wear behaviour of cast aluminium silicon (Al-Si) alloy in dot 4 brake fluid

Abstract : The frictional sliding behaviour of cast Al-Si alloy was investigated with and without DOT 4 hydraulic brake fluid lubrication/environments. Cast Al-Si specimen was produced from wrought alloy and the specimen surface was metallurgically prepared. The as- cast product was characterized with aid of micro-hardness tester, the chemical composition was analysed by X-ray fluorescence (XRF), while X-ray diffraction (XRD) was used to identify phases present, microstructures and surface examinations were done on a high resolution metallurgical Optical Microscope. The properties of the polished and worn sample surfaces were examined by Scanning electron microscope (SEM) equipped with Energy dispersive X- ray (EDS) facilities. A 6mm diameter alumina ball under varying normal loads (3-10 N) was rubbed against the surface of the cast Al-Si coupon specimen. The dry and wet sliding wear behaviour was assessed based on the CoF-sliding time behaviour. From the results, the average CoF values of 0.9064 for dry and 0.2038 for wet contacts were obtained. Comparatively, 1.03E-06 and 4.21E-07 minimum wear intensities; and 467290 and 132170 wear resistances were obtained for dry and wet contacts respectively. Behaviour of cast Al-Si in DOT4 were compared with its performance in DOT3 regarding the hydraulic brake system application

Mass Producing Food Traditions for West Africans Abroad

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65677/1/aa.2007.109.4.616.pd

Improvement of hydroelectric power generation using pumped storage system

Hydroelectric power is a renewable source of energy. By principle, hydroelectric power generation relies on the law of conservation of energy where kinetic energy that resulted from the movement of the mass of water from the river is translated into electr icity, the quantum of which depends on systemic variables viz: plant efficiency, volumetric water flow through the turbine and the head of the water from the water surface to the turbine. Understanding the dynamics of these variables, and the correlation b etween them are core to proper planning and management of a hydroelectric power station. In this Study, simple mathematical methods that include linear programming and statistical analysis based on simulation techniques were used to evaluate vital parameters based on the data obtained from the Hydrologic units of the Shiroro Power Stations in Nigeria. The overall aim of the study is to idealize power generation at Shiroro dam in and out of raining season so as to ensure optimum generation of electricity all year round in order to achieve energy sufficiency in Nigeria. The result of the study is encouraging as it supports the viability of the pumped storage system for generating hydroelectric power all year round. The coupling of the hydroelectric power with pumped storage system if properly harnessed could be the needed panacea for the erratic power supply in Nigeria. Keywords: hydroelectric power, pumped storage, reservoir inflows, turbine, hydrological variables, simulation technique

Effect of heat treatment on wear behaviour of rolled carbon steel in DOT4 brake fluid

Abstract : The wear of heat-treated rolled carbon steels (HTRCSs) were performed under dry and wet sliding in DOT4 brake fluid is successfully investigated and reported in the study. The HTRCSs samples were obtained by heating to and soaking the as-rolled carbon steel (ARCS) at 950 oC prior to quenching or cooling in different media at different selected temperatures between (20 and 250 oC) and atmospheric conditions. The microstructures and wear track patterns of specimens were evaluated using SEM and high-resolution metallurgical microscope. The sliding wear behaviour and wear track patterns of the specimens impressed under 10N normal loads and reciprocating mode was used to assess the wear damages. The obtained wear properties were compared in air and DOT4 fluid environments using Anton Paar TRB tribometer. The results obtained showed that enhanced wear behaviours were obtained from the oil and water quenched samples as compared with the air and furnace cooled samples. The HTRCSs samples are more tolerable than as-rolled sample (ARCS) under dry sliding. However, beside the influences of the heat treatments, the lubricating effect of DOT4 is more pronounced in the results. The CoF ranges from 0.105 to 0.137 for wet sliding while higher CoF values (0.378-0.934) were obtained in the dry sliding

Characterisation and wear behaviour of rolled carbon steel in Dot 4 brake fluid

Abstract : The wear behaviour of as-rolled carbon steel (ARCS) in DOT4 brake fluid is investigated and reported in this study. Sample was characterised using chemical analysis, hardness, impact and tensile strength tests. Arc-spectrometry and the Energy Dispersive X-Ray (EDS) facilities were used to ascertain the chemical compositions. The microstructures and wear track patterns of samples were evaluated using Scanning Electron Microscopy (SEM) and High-resolution metallurgical microscope. The wear of as-rolled carbon steel (ARCS) samples subjected to reciprocating motion of loads at room temperature and constant wear time were compared in air, DOT4 fluid and water. The frictional behaviour and wear track patterns of the specimens subjected to varied normal loads (3, 5 and 10N) under reciprocating sliding wear were employed to assess the wear damage of samples in the three different environments. The coefficient of friction (CoF) obtained tends to be in the order of µDOT4 brake fluid < µwater < µair comparatively for the three test environments

Sustainable Facilities Management Practices in Selected Universities in Ado-Odo/Ota Local Government Area, Ogun State, Nigeria

&nbsp;Sustainable development is being pursued at a global level and acknowledged across all sectors of the economy including universities. In order to apply sustainable measures, universities need to be vigilant in their management approaches. This study aimed at assessing the extent to which the selected universities in Ado-Oda/Ota Local Government Area of Ogun State have incorporated sustainability principles into their facility management practices. The study adopted a qualitative case study approach where interviews were conducted with experts from Covenant University (CU) and Bells University of Technology (BUT) who were purposefully sampled. The study population was comprised of facility managers from the physical planning and development units of the two universities who were chosen because of their expertise and responsibility. The interview guide contained questions about the types of buildings in the universities, sustainable facilities management (SFM) strategies being used by the universities, factors influencing the adoption of SFM strategies at the universities and challenges to the adoption of SFM practices. Data was analysed using conventional content approach. The study found that the universities have partially implemented SFM practices. The common practice adopted by the universities includes energy management. The universities have also done well in waste management. Legislation and cost savings were the drivers for the adoption of SFM practices. Despite such being the case, there are challenges to the adoption and implementation of SFM. These include resource constraints, design constraints, and lack of knowledge about SFM. Therefore, the study recommends development of a system that monitors and evaluates progress of sustainable facilities management practices in the Universities in Ado-Odo/Ota LGA, Ogun State

Optimizing Hydroelectric Power Generation: The Case of Shiroro Dam

Abstract—Hydroelectric power, one of the most important sources of mass generation of electric power, is a renewable source of energy. The amount of electricity that can be produced by a hydro-electricity generating system depends on systemic variables viz; plant efficiency, volumetric water flow through the turbine and the head of the water from the water surface to the turbine. The availability of the Water in the reservoir is a function of some hydrological variables principal among which are rainfall, reservoir inflows and evaporation. Understanding the dynamics of these variables, and the correlation between them are core to proper planning and management of a hydroelectric power station. In this Study, simple mathematical methods that include linear programming and statistical analysis based on simulation techniques were used to evaluate vital parameters based on the hydrologic data obtained from the Hydrologic Units of the Shiroro Power Stations in Nigeria. The overall aim of the study is to idealize power generation at Shiroro dam in and out of rain season so as to ensure optimum generation of electricity all year round in order to achieve energy sufficiency in Nigeria

A suspected case of digitalis toxicity secondary to therapeutic management of congestive heart failure in a Boerboel dog

A 15 months old male Boerboel, weighing 25kg presented to Veterinary Teaching Hospital, Abeokuta, Nigeria, with complaint of abdominal distention, emaciation and anorexia was diagnosed of congestive heart failure (CHF) of unknown etiology. At presentation, prominent S- wave voltages in lead II, III electrocardiogram, a positive R-wave in lead AVR and a mean electrical axis of -900 suggestive of right ventricular enlargement were evident. A right atrial enlargement was also suspected due to the presence of a tented P-wave on the electrocardiogram. Digoxin was administered at 0.01 mg/kg orally, once daily to increase cardiac contractility and reduce heart rate; Enalapril given at 0.5 mg/kg orally once daily was to blunt the renin angiotensin aldosterone response, Furosemide at 2mg/kg orally, once daily was administered to increase natriuresis and diuresis. After 2 weeks of medication the dogs exhibited signs of digitalis toxicity such as ventricular premature contraction, ventricular tachycardia. This case is a rare occurrence and has not been reported in our veterinary clinics. The management of CHF with standard dose regime of digitalis requires therapeutic drug monitoring as it could result in breed specific toxicity

Adsorptive removal of naphthalene and anthracene from aqueous solution with zinc and copper-terephthalate metal-organic frameworks

This research employed the application of metal organic frameworks (MOFs) of zinc and copper-based materials in the removal of naphthalene and anthracene. Naphthalene and anthracene adsorption were investigated with both zinc-benzene-1,4-dicarboxylic (Zn-BDC) and copper-benzene-1,4-dicarboxylic (Cu-BDC) MOFs. Langmuir, Freundlich and Temkin adsorption isotherms were used to investigate the mechanisms of the data obtained. Zn-BDC and Cu-BDC MOFs were stable at a wide range of temperatures and they both exhibited appreciable desorption and regenerating ability. About 97% and 50% removal were recorded for naphthalene and anthracene, respectively. The great success recorded for naphthalene has been attributed to the tighter fitting between the pores of the MOFs materials and naphthalene, as naphthalene molecules are less sterically hindered as compared to anthracene. Desorption and reusability result showed that both MOFs materials demonstrate high regeneration capacity, and the reuse of the materials proved effective for three batch adsorption process.               KEY WORDS: Naphthalene, Anthracene, Refluxing method, Regenerating ability, Adsorption Bull. Chem. Soc. Ethiop. 2019, 33(2), 229-241.DOI: https://dx.doi.org/10.4314/bcse.v33i2.