82 research outputs found

    Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning Systems for Manned Spacecraft

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    Climatic design information has been published for several locations in the world by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) but there has not been data for Nigerian cities in these publications. Therefore, this study was embarked upon to bridge the gap in knowledge. The study of impact of climate change on the design parameters of Heating, Ventilation and Air Conditioning (HVAC) systems for spacecraft cabin environment is presented with particular focus on Ikeja-Lagos, Nigeria. Firstly, the characteristics climate parameters such as outdoor dry-bulb temperature, coincident wet-bulb temperature, relative humidity, pressures, air composition, among others as it affects manned spacecraft were discussed. The data for climatic parameters for Ikeja-Lagos, Nigeria, for a period of fifteen years (1995-2009) were obtained from Nigerian Meteorological Agency (NIMET), Oshodi-Lagos. Statistical data and Microsoft excel were used for evaluation of variation trends of the climate parameters for departure city. This is very important in determining thermal human comfort in spacecrafts on ascent. Results obtained from this study are hereby presented. The Ikeja-Lagos dry-bulb temperature average results obtained were 33.81°C, 32.98°C, 32.3°C, 22.1°C, 21.19°C, 20.43°C, 23.84°C and 31.65oC.at 0.4%, 1.0%, 2.0%, 97.5%, 99.0%, 99.6%, median of extreme lows and median of extreme highs, respectively. The Ikeja-Lagos relative humidity average results were 116.3, 112.65, 109.14, 99.83 and 49.42 at 0.4%, 1% and 2.0% occurrence as well as at median of extreme highs and median of extreme lows, respectively. Ikeja-Lagos had mean coincident dry bulb temperature of 33.81°C and 32.98°C at 0.4% and 1% percentile respectively. The dry bulb temperature for Ikeja-Lagos was determined to be an average range from 20.43°C to 22.1°C between January to December, in the period of 1995-2009, at 97.5% 99% and 99.6% percentile respectively. These results provide values of design parameters which are useful in the design of HVAC for space crafts with climate change adequately taken into consideration as it applies to Ikeja-Lagos, Nigeri

    Optimised intake stroke analysis for flat and dome head pistons

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    This research exerts are suitable for the automobile industry in understanding the performance characteristics optioned between flat head and dome head pistons in engine design. This study was carried out to analyze the optimization parameters for effective and efficient flow characteristics of air-fuel mixture at the intake port of the combustion chamber of an internal combustion engine. A unique and industrial standard CFD software, STAR-CCM V8, was used to model both geometry for flat head and dome head pistons which was developed with precise dimensions of a 1.8L gasoline engine. A planar 3-D model approach was adopted for simplified static CAD modeling and also to reduce the solver processing time. The piston models were meshed using tetrahedral mesh of base size 0.001m. The boundary and physics conditions were applied to simulate the actual intake stroke process for normal operating conditions and initial conditions. The extracted results were validate and comparisons developed to analyze the various optimization parameters for performance characteristics of the two pistons.Keywords: optimized intake stroke, CFD analysis, flat and dome head pistons, internal combustion engine, CAD modellin

    Impact Of Marketing Strategies And Performance Of Banks And Its Ffects On Nigeria Economy

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    The banking industry has been facing a lot of challenges in recent times in Nigeria. These include competition among them and non banking financial institutions such as insurance Companies. Therefore this research, impact of marketing strategies and performance of banks and its effects on Nigeria economy is aimed tonbsp identify the various types of the marketing mix components employed by thenbsp banks . to examine the effect of the marketing strategies on the performance of the banks. Andnbsp to determine if the marketing strategies employed by the Banks differ significantly from one another. Questionnaire was administered on two population which arenbsp Management andnbsp staff of thenbsp banks and customers of thenbsp banks. 250 questionnaire was administered tonbsp Management andnbsp staff of thenbsp banks,nbsp and also 250 was administered to customers of the bank in Nigeria. Result of the analysis revealed four factors which were distribution network, quality of service, promotion and price with the percentage contribution of each factor being 51.9%, 73.6%, 31.2% and 38.5% respectively. Multiple regression analysis shows that R2 = 0.563 which indicated that the four factor accounted for 56% variability in the performance ofnbsp marketing strategies employed by the banks. The result of the analysis of variance indicated that the mean ratings for thenbsp banks were not significantly different at 0.05level. We thereby conclude that banks should focus its innovative efforts on enlarging the size of the market in which it participates by introducing new products and services, promoting new uses for existing products and seeking out new class of customers

    Antinociceptive and anti-arthritic properties of hydroethanolic leaf extract of Clausena anisata (Willd.) Hook. f. ex Benth (Rutaceae) in Rodents: possible mechanism of actions

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    Summary: The leaves of Clausena anisata (Willd.) Hook. f. ex Benth (Rutaceae) is used in Traditional African medicine for the treatment of various ailments including arthritis. The present study sought to investigate the antinociceptive and anti-arthritic properties of hydroethanolic leaf extract of Clausena anisata (HeCA). HeCA (100, 200 or 400 mg/kg, p.o.) was administered 1 h before intraplantar injection of formalin 1%v/v in saline to evaluate antinociceptive effect. Moreover, its possible mechanism of antinociceptive action was investigated through pretreatment of mice with antagonists of receptors implicated in nociception. Anti¬inflammatory effect of the extract was investigated using the carrageenan-induced paw oedema and complete Freund's adjuvant (CFA)-induced arthritis models in rats. HeCA (400 mg/kg) treatment significantly reduced the duration of paw licking/biting during both in the early (42.12%) and late (75.79%) phases of formalin-induced nociception. However, the antinociceptive effect elicited by HeCA was reverse by pretreatment of mice with naloxone, prazosin, yohimbine, ketanserin, L-arginine, and parachlorophenylalanine (PCPA). HeCA produced dose-dependent and time course decrease in carrageenan-induced paw oedema. Pre- and post-treatment of rats with HeCA ameliorated CFA-induced arthritis evidenced in the significant decrease in arthritic index comparatively similar to the effect of celecoxib. CFA- induced oxidative and nitrosative stress were attenuated by subchronic treatment with HeCA. Findings from this study shows that C. anisata possesses antinociceptive activity through possible interaction with opioidergic, noradrenergic, L-arginine-nitric oxide and serotonergic pathways as well as anti-arthritic property which could be attributed to its ability to prevent the release of inflammatory mediators and oxidative stress.Keywords: Complete Freund's adjuvant; L-arginine-nitric oxide; nociception; antioxidant; rheumatoid arthritis; serotonergic

    Suitability Assessment of Soils around Forestry Research Institute of Nigeria (FRIN), Ibadan for Maize Production: A Parametric Analyses

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    The sustainable use of soil resources requires extensive knowledge about its morphology and other properties. The study was carried out to evaluate the suitability of soils for maize production in Forestry Research Institute of Nigeria’s (FRIN), environment, Ibadan, using the parametric method. Four profile pits were dug, described and the soil samples collected and analyzed for particle size distribution, pH, organic matter, total nitrogen, available phosphorus, exchangeable acidity, exchangeable bases and extractable micro nutrients. The textures of the soils were loamy sand, sandy loam and sandy clay loam which varied in response to changes in slope and drainage position. The soil’s pH ranged from strong to slightly acidity (4.32 – 6.75). Organic matter (17.2 -61.2g kg-1), total exchangeable base and total nitrogen (0.7 – 3.1g kg-1) were high, while the extractable micro nutrients; Fe (37 – 67mg kg-1), Cu (7 – 13mg kg-1), Mn (5 – 142mg kg-1) and Zn (38 -134mg kg-1) were at toxic level. Suitability evaluation of the soil using parametric approach shows that the soils are presently not suitable (NS) for the cultivation of maize, while, the potential of suitability of the soil for maize cultivation was ranked marginally suitable (S3). The soils of the study area were classified as Egbeda association which is not currently suitable for maize production, because of its present status. However, the soils suitability potential can be improved through conservative agronomic practices and also to prevent rapid degradation

    GEOELECTRIC PARAMETERS AND ELEMENTAL COMPOSITIONS OF THE TOP SOIL OF CAMP AREA, ABEOKUTA, SOUTH WESTERN NIGERIA

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    Vertical Electrical Sounding (VES) and elemental composition surveys were carried out at twenty-two (22) sites atª¤? Camp Area, Alabata Road, Abeokuta, Southwestern Nigeria. This was with a view to determining depth to water«¤??bearing zones and extent of soil contamination thereby saving residents not just the pain of recurrent losses incurred for investing in dry wells, but also not to invest in contaminated waters. The study area is underlain by associated rock suites which includes pegmatite and quartz veins. Field data obtained was modeled and interpreted to obtain the geophysical parameters of the area and delineate the groundwater potential zones. Soil samples were also collected at the 22 VES points, at depths of 10 cm and 100 cm; the Global Positioning Satellite (GPS) equipment was used to obtain the geographical position of each sample point. Determination of the elemental composition of soil samples collected at the 10 cm and 100 cm depths was made using Atomic Absorption Spectrophotometer. Two heavy metals (Pb, and Cr), five major elements (K, Ca, N, P and Mg) and five trace elements (Zn, Mn, Cu, Al and Fe) were detected. It was observed that the values, representing the amount of the heavy metals, the major elements, and the trace elements were far less, mostly insignificant, at the 100 cm depth representing about the interface between the first and second layers in majority of the VES stations sampled, than at the 10 cm depth, representing the topsoil of the first layer. The implication of this is that the elements are not strictly domiciled within the area studied but may be due to runoffs as the area slopes down. Moreover, going by the values at the 100 cm depth, the elements may not be capable of percolating into the underground water zones in the area of study, and thus might not have contaminated the underground water. Thus, at the current level, the underground water can be adjudged safe for human consumption.ª¤
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