205 research outputs found
Effect of using vegetable oils as quenching media for pure commercial aluminium
This paper presents the effects of rate of heat extraction by groundnut, melon, palm kernel, shea butter
and palm oils on the mechanical properties of various samples of pure commercial aluminium heat
treated at 200°C, 250°C, 300°C and 350°C. Muffle furnace equipped with digital thermometer and
thermocouple was used for the heat treatment. Tensile strength and hardness tests were carried out
using Instron Universal Tester and Vickers hardness methods, respectively. Results obtained from the
experiment were presented graphically. The results showed that palm kernel oil cools faster at 200°C and
250°C, while palm oil and shea butter oil quench faster at 300°C and 350°C, respectively. Palm kernel oil
offers the highest elongation at 200°C, while at 350°C shea butter oil gave the best result. The best
among the bio-quenching oils in providing good ductility is shea butter oil at 200°C, while at 300°C and
350°C groundnut oil give the best result. Highest hardness values were obtained from samples quenched
in melon oil between 200°C-300°C. However, these values decreased with increased heating
temperature probably due to density and viscosity variation with temperature rise. Similar observations
were made on most of other samples quenched in other bio-quenching oils used in this experiment. This
study shows that these locally available vegetable oils have promising potentials to serve as a possible
replacement for non-biodegradable mineral oils in many applications
Anticipated Change in the Nigerian Capital Market and Its Implication on Economic Growth
This paper examines the Anticipated Change in the Nigerian Capital Market and its implications on Economic Growth. Data were collected through secondary source and analyzed using multiple regression and descriptive method of statistical analysis. The study reveals that market capitalization, value of stocks and interest rate has significant impact on the GDP. The paper recommends that government should step up investor’s confidence and activities in the capital markets so that it could contribute significantly to economic growth hence, national development. Keywords: Market Capitalization, Economic Growth, Capital Market, Nigerian Stock Exchange, Structural Adjustment Programme, Gross Domestic Produc
Comparative Analysis of Pre and Post-migration Livelihood Outcomes of Households with Absentee Heads in Osun State, Nigeria
Migration is often linked with a deleterious impact on rural area production and development. Although, the change of location for better opportunities also affect the lives and livelihoods of the migrant households’ in the rural communities. The study was a comparative analysis of the pre and post-migration living outcomes of absentee households’ heads in Osun State, Nigeria. A multistage sampling procedure involving the simple random sampling was used to select 120 absentee household heads. Data collected with interview schedule was subjected to descriptive statistics, t-test and correlation analyses. Findings showed that more men (76.7%) migrated, leaving women to become the interim household heads. It was found that migrants have a higher average monthly income level (₦44,400). Prior to migration, most families were in the lower financial well-being category (83.3%), while only 55% remained in that category after migration. This follows the result of the t-test which revealed that a significant difference (t=0.00; p<0.05) exists between the well-being of migrant’s household before and after migration. Thus, it was concluded that unless the rural push factors are removed, rural-urban migration will continue at an increasing rate because benefits and opportunities acquired in the process influence the well-being of the rural households. The study recommends that enabling environment, facilities and opportunities should be created in the rural communities to transform livelihoods and improve the wellbeing of the people via interventions by national and international agencies
Effect of Two Cowpea (Vigna unguiculata) Fodder Cultivars as Supplements on Voluntary Intake; Milk Yield and Manure Production of Bunaji Cows
The feeding value of fodder from two cowpea cultivars to a basal maize stover diet was investigated using fifteen lactating White Fulani (Zebu) cows. The two cultivars were IT-716 and 994-DP. Diet was constituted as 50g DM/kg live weight and each of the cultivars was supplemented at 50% of the daily dry matter requirement of individual animals. The experimental design was a complete randomize. The parameters measured included feed intake, milk yield and composition and manure production. In a separate trial, dry matter degradation of the fodder was assessed. There were no significant differences in dry matter intake of the supplements. However, the dry matter intake of stover in the control diet was higher than those on the supplemented groups. The milk yields ranged from 887 to 1378 ml/day. Milk yield differed among treatments. Supplementation did not affect (P 0.05) fat, protein, total solids and ash contents of the milk across the treatments. Manure productions were not significantly different among the treatments. Similarly, content of N, P and K in manure were comparable among the treatments except for N that was lower (P 0.05) in the control group. The dry matter degradation was influenced by the fodder cultivars. The feeding of dual-purpose forage legumes residues could enhance milk production in lactating Zebu cows. This may be further increased by exploring other ways of improving feed residue utilization in the dry season
EVALUATION OF TWO-STAGE SUBSURFACE FLOW CONSTRUCTED WETLANDS FOR ABATTOIR WASTEWATER MANAGEMENT
Abattoir wastewater is high in organic content, the waste recovery and treatment facility is expensive and this results in indiscriminate dumping into streams without adequate treatment. The effectiveness of using a two-stage subsurface flow constructed wetland to treat abattoir effluent was examined in this study. Diluted abattoir wastewater from Lafenwa Abattoir, Abeokuta, Ogun State, Nigeria was fed into a two-stage Vegetated Subsurface Bed Constructed Wetlands (VSBCW). The VSBCW consisted of 500 mm deep 10-15 mm diameter granite with 150 mm thick overlay of well graded sand planted with locally available Vetiveria nigritana. Grab samples were collected at selected points along Ogun river and measurement of physico-chemical parameters such as: Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD5), Electrical Conductivity (EC), Total Dissolved Solids (TDS) and Total Suspended Solid (TSS) of the influent and effluent from the VSBCW were carried out. Irrigation with water and diluted abattoir wastewater to examine the variation in plant growth rate was also investigated. The results revealed a pollution load reduction as the wastewater moves away from the discharge point but inadequate to meet the FEPA (1991) standard for wastewater discharge into rivers. The VSBCW was observed to reduce the concentration of BOD5, COD, EC, TDS and TSS in the abattoir wastewater by 88.71, 87.28, 45.72, 56.89 and 72.27 % respectively. The growth rate of the V. nigritana reduced by 1.9% when irrigated with abattoir wastewater. The study revealed that locally available V. nigritana in VSBCW is effective in abattoir wastewater treatment and could be use to curtail the pollution caused by discharge of untreated wastewater into rivers.
 
Service planning and delivery outcomes of home adaptations for ageing in the UK
In response to the impact of demographic change on the healthcare system, ‘ageing in place’ was introduced as a national policy to support elderly people living independently in their homes. Housing adaptation is essential for successful independent living and has been given increased political priority. However, adaptation policies and practice vary regionally, reflecting statutory limits, policy choices and local planning. This study investigated the current status of adaptation provision in different regions in the UK and assessed the effectiveness of local service planning and management. A mixed-methods sequential explanatory research strategy was employed. In the first quantitative phase, a questionnaire survey was carried out involving all 378 local authorities in England, Scotland and Wales. This was followed by a second qualitative phase involving individual interviews with five professionals and two clients and a focus group meeting with six key stakeholders. The study found that the current number of adaptations was relatively small compared with potential demands in most local areas, as was funding for adaptations. On the operational side, the adaptation process was fragmented, involving different service groups in many local authorities. There were disconnections between these groups, which often caused inefficiencies and poor effectiveness. Moving forward, local authorities need to have a clear vision of the overall need for adaptations and allocate sufficient resources. Practical guidelines are also needed for better integrated working and performance management
Does the spillage of petroleum products in Anopheles breeding sites have an impact on the pyrethroid resistance?
<p>Abstract</p> <p>Background</p> <p>The emergence of <it>Anopheles </it>populations capable of withstanding lethal doses of insecticides has weakened the efficacy of most insecticide based strategies of vector control and, has highlighted the need for further studies on the mechanisms of insecticide resistance and the various factors selecting resistant populations of mosquitoes. This research targeted the analysis of breeding sites and the oviposition behaviour of susceptible and resistant populations of <it>Anopheles </it>in localities of spilled petroleum products. The aim was to establish the possible contribution of oil spillage in the selection of pyrethroid resistance in malaria vectors.</p> <p>Methods</p> <p><it>Anopheles </it>breeding sites were identified and the insecticide susceptibility of the <it>Anopheles gambiae </it>populations mapped in 15 localities of South Western Nigeria. The presence of oil particles as well as the turbidity, the dissolved oxygen and the pH of each identified breeding site was recorded. Data were cross-analysed to correlate the habitat types and the insecticide susceptibility status of emerging mosquitoes. The second phase of this study was basically a laboratory model to provide more information on the implication of the spillage of petroleum on the selection of pyrethroid resistance in <it>An. gambiae</it>.</p> <p>Results</p> <p>Moderate levels of resistance following exposure to permethrin-impregnated papers were recorded with the majority of <it>An. gambiae </it>samples collected in the South Western Nigeria. Data from this study established a link between the constituency of the breeding sites and the resistance status of the emerging <it>Anopheles</it>.</p> <p>Conclusion</p> <p>This study has revealed the segregational occupation of breeding habitats by pyrethroid resistant and susceptible strains of <it>An. gambiae </it>in south-western Nigeria. Compiled results from field and laboratory research point out clear relationships between oil spillage and pyrethroid resistance in malaria vectors. The identification of this factor of resistance could serve as strong information in the management of insecticide resistance in some West African settings.</p
Epidermal growth factor mediates spermatogonial proliferation in newt testis
The complex processes of spermatogenesis are regulated by various factors. The aim of the current study is to determine the effect of epidermal growth factor (EGF) on spermatogonial proliferation and clarify the mechanism causing the proliferation in newt testis. In the organ culture, EGF stimulated spermatogonial proliferation, but not their differentiation into spermatocytes. cDNA cloning identified 3 members of the EGF receptors, ErbB1, ErbB2, and ErbB4, in the testis. RT-PCR showed that all the receptors cloned were expressed in both Sertoli and germ cells at the spermatogonial stage. In the organ cultures with inhibitors for the EGF receptors, mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K), the EGF-induced spermatogonial proliferation was suppressed. Furthermore, when the organ culture was exposed to EGF, the expressions of stem cell factor (SCF), immunoglobulin-like domain containing neuregulin1 (Ig-NRG1), and ErbB4 mRNA were increased. These results suggested that, since the spermatogonia are sequestered within cysts by the blood-testis barrier consisted of Sertoli cells, EGF possibly mediates spermatogonial proliferation in an endocrine manner through the receptors including ErbB1, ErbB2, and ErbB4 expressed on Sertoli cells via activation of MAPK cascade or/and PI3K cascade by elevating the expressions of SCF, Ig-NRG1, and ErbB4
A phylogenetic classification of the world’s tropical forests
Knowledge about the biogeographic affinities of the world’s tropical forests helps to better understand regional differences in forest structure, diversity, composition and dynamics. Such understanding will enable anticipation of region specific responses to global environmental change. Modern phylogenies, in combination with broad coverage of species inventory data, now allow for global biogeographic analyses that take species evolutionary distance into account. Here we present the first classification of the world’s tropical forests based on their phylogenetic similarity. We identify five principal floristic regions and their floristic relationships: (1) Indo-Pacific, (2) Subtropical, (3) African, (4) American, and (5) Dry forests. Our results do not support the traditional Neo- versus Palaeo-tropical forest division, but instead separate the combined American and African forests from their Indo-Pacific counterparts. We also find indications for the existence of a global dry forest region, with representatives in America, Africa, Madagascar and India. Additionally, a northern hemisphere Subtropical forest region was identified with representatives in Asia and America, providing support for a link between Asian and American northern hemisphere forests
Review of natural fibre-reinforced hybrid composites
Natural fibre-reinforced hybrid composites which contain one or more types of natural reinforcement are gaining increasing research interest. This paper presents a review of natural fibre-reinforced hybrid composites. Both thermoplastic and thermoset composites reinforced by hybrid/synthetic fibres or hybrid/hybrid fibres are reviewed. The properties of natural fibres, the properties and processing of composites are summarised
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