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

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

NIGERIA’S ENERGY CHALLENGE AND POWER DEVELOPMENT: THE WAY FORWARD

The ever increasing demand and meager supply of energy in Nigeria has been a great challenge to her development. This situation is becoming critical, with increasing population not balanced by an adequate energy development programme. The incessant power generation failure has grossly affected the economy, seriously slowing down development in rural and sub-rural settlements, with present energy policy mainly benefiting urban dwellers. Globally, energy projections stipulate that between 2002 and 2025, global energy needs may rise by over 34%, with that of developing nations doubling this percentage. A robust solution must be found to end the nation’s energy crises. This Viewpoint compares the energy potential of Nigeria with the challenges faced. Nigeria receives a huge amount of solar radiation, has abundant wind energy resources, and large deposits of fossil fuel, as well as enormous hydro-power resources from Niger and Benue Rivers. However, of these about 80% of hydro-power remains untapped, the total 5.5KW-hr/m2/day of solar radiation is not utilized and wind energy resources remain unexploited. The solution lies in creating a mixed supply of energy in which as yet untapped renewable resources are combined with abundant nonrenewable fossil fuel, including the massive quantities of gas wasted from crude oil exploitation

Nigeria's energy policy:Inferences,analysis and legal ethics toward RE development

The study critically assessed the various policy issues of sustainable energy development in Nigeria.The basic focus was to discuss and analyze some of the laws of the federationasit relates to the development of Renewable Energy in Nigeria.It surveyed the nation's energy policy statement and the vision20:2020 of the federal government.The Renewable Energy Master Plan developed by the joint efforts of the Energy Commission of Nigeria and United Nations Development Programs were also appraised.The level of development and the index of renewable energy production as stated by the policy statement,the vision 20:2020 and the Renewable Energy Master Plan were highlighted.The study found some policy challenges which include weak government motivation,lack of economic incentives,multiple taxations, non-existent favorable customs and excise duty act to promote renewable energy technologies.Further to this,some legal reforms which mayaid the promotion of renewable energy development in Nigeria and also make robust the nation's energy policy were proposed.Some of the laws that require amendment topromoterenewableenergyincludethelanduseact,environmentalimpactassessment decree andtheinvestmentlawsofthefederationofNigeri

Constitutive Modeling of Wind Energy Potential of Selected Sites in Nigeria: A Pre-Assessment Model

In this chapter, the authors present the result of a study carried out to develop a pre-assessment model that can be used to carry out a preliminary study on the availability of wind energy resources of a site. 21 years’ (1987 – 2007) monthly average wind speeds for 18 locations in Nigeria were used to create the simple constitutive model. The locations span across the six geopolitical zones of the nation with three stations from each zone. Various statistical procedures were employed in the development of the model. The outcome gave an empirical model, which if employed, will lead to determining the mod- est range of wind energy potential of a site. Further, the results from this model were compared with those from the well-established two-parameter Weibull statistical distribution function and found to be reasonably adequate. Thus with this model, decision on site selection for complete assessment can be made without much rigour

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

Assessment of Wind Power Potential and Wind Electricity Generation Using WECS of Two Sites in South West, Nigeria

The study was used to analyze the wind characteristics of Shaki (08.40’ N; 03.23’ E; Altitude 457.0 m; Air density 1.1723 kg/m3) and Iseyin (07.58’ N; 03.36’ E; Altitude 330.0 m; Air density 1.1869 kg/m3), two local sites in Oyo State, Nigeria. 21 years monthly mean wind speeds at 10 m height obtained from the Nigeria meteorological department were employed together with the Weibull 2-parameter distribution and other statistics to carry out monthly, seasonal and whole years’ analyses of the sites’ wind profiles for electricity generation. It was found that the whole data spread ranged between 0.9 and 9.1 m/s for the two sites while the 21 years’ average ranged between 3.2 and 5.1 m/s and 2.9 and 4.7 m/s for Shaki and Iseyin sites respectively. Three wind energy conversion systems were employed with the results and it was discovered that, the sites have capacity to generate MWh to GWh of electricity at an average cost/kWh of between € (0.025 and 0.049) and that a turbine with technical parameters of cut-in, cut-out and rated wind speeds of 3.0, 25 and 11.6 m/s is appropriate for the sites

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

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

Rauvolfia vormitoria Effect on the Degradation of Aluminium Alloy in 2.5 M Hydrochloric Acid Solution

The deterioration of aluminium alloy in 2.5 M hydrochloric acid in the presence Rauvolfia vormitoria extract was examined using both gasometric and gravimetric techniques. Aluminium coupons measuring 4 cm by 1 cm were introduced into test solutions of uninhibited acid and also those containing extract quantities of 10, 20, 30 and 40 cm3 at ambient temperature of 250C for a total cumulative period of 117 minutes. The volumes of hydrogen gas evolved and weight loss readings were recorded and analyzed to obtain weight loss and corrosion rate for each coupon at specific time intervals. The results however, showed that while extract quantity was increasing; weight loss measurements increased but inhibitor efficiency decreased. Also, the metal surface-phytoconstituent interaction mechanism was consistent with the Temkin adsorption isotherm and the 3 minutes curve showed the best exposure time for phytochemicals to adsorb to alloy surface. Furthermore, microstructural studies showed an indirect relationship between metallic degradation and extract quantity, while uniformity of the irregular intermetallic phases increased with increasing extract quantity