EVALUATION OF THE TEMPERATURE EFFECT OF A THERMOSYPHON SOLAR WATER HEATER

This study investigated the effect of system temperature on the performance of thermosyphon solar water heater. Solar collector was designed and developed with galvanized steel, wood and copper pipes for the experiment. While the copper pipes serves as the tube through which the cold water flows, the wood was employed for the frame and stand, and the galvanized steel for the collector material. Also employed were two hot and cold water tanks of 60 and 110 litre capacities respectively. The period of experiment were taken to be 3 days each for sunshine, sun-off and moderate sunshine days, with the average data employed for the analysis. The results showed that temperature has a domineering effect on the performance of the thermosyphon system. The maximum outlet temperature obtained for sunshine, moderate sunshine and sun-off days were 94.6, 73.5 and 51oC respectively. Also the system efficiency was found to be 61.04%, demonstrating good performance. However, considering the fact that the experiment was carried out in rainy season (between April and September), it was concluded that if it is repeated during the dry periods (October to March), the efficiency of performance will be more as these period is characterized by low cloud cover, high temperature and high radiation intensities. The outcome of the study was compared with published results and it clearly demonstrates that the designed system can suitably be employed for both domestic and industrial uses

The incidence of Nypa fruticans (Wurmb) and its impact on fisheries production in the Niger Delta mangrove ecosystem

Nypa fruticans occurs in Bayelsa, Rivers, Akwa Ibom and Cross River State, Nigeria; invading an estimated area of 821 Km super(2) mangrove dominated swamps. Human activities such as tree felling, urbanization, oil and gas exploration and exploitation and other activities led to the interference in the normal mangrove by the Nypa palm. Lack of utilization by the local population of the Nypa palm as in into-pacification has increased the population over the years. The effect includes the reduction in primary and secondary productivity, disruption of food chain and erosion of riverbanks. The eradication of the Nypa palm from the Niger delta mangrove ecosystem and replacement with red and white mangroves will restore the ecosystem health and enhance biological diversit

Investigating the Acid Failure of Aluminium Alloy in 2 M Hydrochloric Acid Using Vernonia amygdalina

The acid failure of aluminium alloy in 2 M hydrochloric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Aluminium alloy coupons of dimension 4 cm by 1 cm were immersed in test solutions of free acid and also those containing extract volumes of 2, 3, 4 and 5 cm3 at ambient temperature for 30 minutes. The volumes of hydrogen gas evolved as a result of the rate of reaction were recorded and analyzed. Analysis revealed that maximum inhibitor efficiency which corresponds to the lowest corrosion rate was obtained at optimum inhibitor volumes of 5 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volumes. Adsorption study revealed that Temkin isotherm best described the metal surface interaction with the extract phytochemicals, with 12 minutes becoming the best exposure time for the phytochemicals to adsorb to the metal surface at all volumes. Statistical modelling of the corrosion rate yielded an important relationship suitable for estimating corrosion rate values once volumes of the extract is known. Microstructural studies, showed an indirect relationship between crack growth rates and extract volumes, while consistency of the irregular intermetallic phases increases with increasing extract volumes

Effect of Expression Conditions on the Yield of Dika Nut (Irvingia Gabonesis) Oil under Uniaxial Compression

Efficient expression of Dika nut oil from the kernel is required for its subsequent use in producing comparatively cheap lubricant. Various factors responsible for proper oil expression include particle size, moisture content, heating temperature, heating time, pressing pressure and pressing time. Sundried Dika kernel ground to two particle sizes (fine: ≤ 1.4 mm and coarse: between 1.4 and 2.8 mm) were conditioned to moisture content of 3, 6 and 9 wt%. Considered in the study, are heating temperature ranging from 50 to 150oC in steps of 25 degrees Celsius and heating time of 5 to 25 minutes in steps of 5 minutes. Pressing pressure of 5 to 25 MPa in steps of 5 MPa and pressing time of 2 minutes interval were also considered. The maximum oil yield was then correlated with the processing conditions. Test results showed that coarse particle gave higher oil yield. Maximum oil yield of 72.2% of the available oil was obtained at 6% moisture content, heating temperature of 100oC and heating time of 10 minutes. Regression analyses of the oil yield with heating temperature, heating time, and pressing gave r2 values of 0.9678, 0.999 and 0.9128. The processing conditions therefore has significantly influence the quantity of oil obtained from Dika kerne

Security oriented e-infrastructures supporting neurological research and clinical trials

The neurological and wider clinical domains stand to gain greatly from the vision of the grid in providing seamless yet secure access to distributed, heterogeneous computational resources and data sets. Whilst a wealth of clinical data exists within local, regional and national healthcare boundaries, access to and usage of these data sets demands that fine grained security is supported and subsequently enforced. This paper explores the security challenges of the e-health domain, focusing in particular on authorization. The context of these explorations is the MRC funded VOTES (Virtual Organisations for Trials and Epidemiological Studies) and the JISC funded GLASS (Glasgow early adoption of Shibboleth project) which are developing Grid infrastructures for clinical trials with case studies in the brain trauma domain

Thermodynamics Characterization of Density models for an Effective Solar Water Heater Sizing

The problem faced in Sizing of an effective Solar Water Heater (SWH) by engineers to meet certain design requirement is highly enormous. Using the thermodynamic characterization relation and the knowledge of Solar Water Heater (SWH) density’s model; various design were evaluated. The result shows that density model actually predicts adequately and providing alternative means of estimating these design parameters. Also, the properties of the system, such as entropy and enthalpy (specific heat capacities), which cannot be determined directly from experimental axiom, were evaluated. These evaluations therefore, give room to express the thermodynamics properties of the system and consequently improve the design performance. Further comparisons with experimental results reveal a better outfit. Therefore through the knowledge of thermodynamic relation an efficient Solar Water Heater is operated and empirical data is expanded

Acid Failure of Mild Steel in 2 M Sulphuric Acid in the Presence of Vernonia amygdalina

The degradation of mild steel in 2 M sulphuric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Mild steel coupons of dimension 4 cm by 1.5 cm were immersed in test solutions of uninhibited acid and also those containing extract concentrations of 60,100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the reaction were recorded and examined. The results showed that while extract concentration was increasing, H2 evolution and % I.E increased, with a reduction in corrosion rate. The reduction in corrosion rate was observed to follow in order of increasing extract concentration. Also, phytoconstituent-metal interaction mechanism was best explained by Freundlich isotherm, with the 4 minutes curve becoming the best contact time for the extract phytochemicals to properly adsorb to metal surface across all concentrations used. Furthermore, an expression suitable for estimating corrosion rate values once concentration is known was also obtained. The microstructural studies however, revealed that increasing the extract concentration led to considerable reduction in the dominant coarsening of the oxide of iron phase, while the pearlite and ferrite phases were highly dispersed

Data ontheno-loadperformanceanalysis of atomatopostharveststoragesystem

In thispresentinvestigation,anoriginalanddetailedempirical data onthetransferofheatinatomatopostharveststoragesystem waspresented.No-loadtestswereperformedforaperiodof96h. The heatdistributionatdifferentlocations,namelythetop,middle and bottomofthesystemwasacquired,atatimeintervalof 30 minforthetestperiod.Thehumidityinsidethesystemwas taken intoconsideration.Thus,No-loadtestswithorwithout introduction ofhumiditywerecarriedoutanddatashowingthe effect ofariseinhumiditylevel,ontemperaturedistributionwere acquired.Thetemperaturesattheexternalmechanicalcooling components wereacquiredandcouldbeusedforshowingthe performance analysisofthestoragesyste