Showing papers in "Journal of Emerging Trends in Engineering and Applied Sciences in 2011"

Nutritional Composition of the Leaves and Stems of Ocimum Gratissimum

Abstract: The leaves and stems of Ocimum gratissimum was analysed for its proximate and mineral composition. The proximate composition give the following results:82.60 ± 0.01% and 82.60 ± 0.11% moisture content for leaves and stems; 13.67 ± 0.13% and 13.67 ± 0.02% ash content for leaves and stems; 3.33 ± 0.07% and 1.65 ± 0.02% crude protein content for leaves and stems; 8.50 ± 0.04% and 3.00 ± 0.15% crude lipid content for leaves and stems and 9.52 ± 0.01% and 19.65 ± 0.03% crude fiber content for leaves and stems. Higher carbohydrates content in the leaves (64.98 ± 0.01%) and stems (62.03 ± 0.04%) give a corresponding increase in the energy value (343.08 ± 0.01 kcal/100g) for the leaves and (278.42 ± 0.11 kcal/100g) for the stems respectively. Potassium content was the highest among the mineral elements analysed with 1479.88 ± 0.01 mg//100g for the leaves and 2150.01 ± 0.11 mg//100g for the stems. Higher potassium content in the stems qualify it as a good source of this mineral elements for the hypertensive patient since potassium reduce the risk of been hypertensive. The leaves are good sources of Cu, Fe, Mn and Zn when compared to their respective RDA.

Production, characterization and evaluation of castor oil biodiesel as alternative fuel for diesel engines

Abstract: In this study, the use of castor oil methyl ester as possible alternative fuel for diesel engines was investigated. The oil was extracted in a soxhlet extractor using normal hexane as solvent. To overcome the high kinematic viscosity of the neat oil, a high molar ratio of 6 : 1 was used to produce the methyl ester. The viscosity of the ester was high and further reduced by blending with diesel fuel to reduce it to within the American Society for Testing and Materials (ASTM) D6751-02 limits for biodiesel. The biodiesel was characterized and tested in a single cylinder diesel engine. The results obtained gave properties, torque outputs and specific fuel consumption that are close to those of diesel fuel thus confirming that it can be used as alternative fuel for diesel engines. Chromatography analysis of the methyl ester shows that it contains 90% ricinoleic acid which is a monounsaturated, 18-carbon fatty acid with a high polarity hydroxyl functional group at C12 and ester linkages that makes the fuel unsaturated and with a wide range of industrial applications.

Sorption of lead (II) and copper (II) ions from aqueous solution by acid modified and unmodified Gmelina Arborea (Verbenaceae) leaves

Abstract: Gmelina arborea leaves of tropical origin were modified with citric acid as esterifying agent and was used to selectively removed Pb(II) and Cu(II) ions from aqueous solution by batch adsorption method. The concentrations of the metal ions adsorbed were determined by atomic absorption spectroscopic (AAS) method. The citric acid had a strong significant effect on the removal of metal ions from solution because of an increase in the carboxyl groups introduced into the biosorbent. The amount of metal ions removed from solution was found to depend on the metal ion-substrate contact time, ion concentration and ion type. The results indicated that after 90 minutes contact time, the amount of adsorbed metal ion increased with increase in the initial metal ion concentration up to 20 mg/cm3. This also varied with the cellulosic materials in the order Pb(II)>Cu(II). The acid modified Gmelina arborea leaves adsorbed more metal ions than when unmodified. The equilibrium data fitted well to the Freundlich adsorption isotherm. The Gmelina arborea leaves were better adsorbents of Pb(II)ion than Cu(II) ion.

Thermodynamic assessment of grid-based gas turbine power plants in Nigeria

Abstract: Thermodynamic assessment of grid-based gas turbine power plants in Nigerian energy utility sector is presented based on second law analysis (energy and exergy). The primary objective of this study is to evaluate the performance parameters for the turbine plants and identify components of the turbine system that offer opportunities for thermodynamic improvement. The performance of the plants were estimated by component-wise modeling and a comprehensive break-up of energy and exergy losses for the considered plants were determined using the daily operating data. Performance analyses based on energetic and exergetic criteria such as thermal efficiency, exergy efficiency, exergy destruction rate, efficiency defect and exergetic performance coefficient were performed based on these operating data for all the considered plants. The percentage ratio of the exergy destruction to the total exergy destruction in the plants was found to be maximum in the combustion chamber followed by the turbine, calculated to be between 6.7-7% for compressor, 16.6-18 % for turbine and 74 and 85% for combustion chamber. The combustion chamber and turbine are the two components found from the research to offer opportunity for thermodynamic improvement. However, the results obtained are found to provide comprehensive information for which plant performance improvement and optimization can be obtained.

Assessment of traffic safety and awareness among youth in Al-Ahsa Region, Saudi Arabia

Abstract: Due to the importance role of traffic regulations knowledge and awareness in the reduction of traffic accidents, especially among the youth, this study was initiated to assess the traffic regulations knowledge and awareness of university and high school students in Al-Ahsa region, Saudi Arabia. To meet the objective of this study, a survey was designed and distributed to students at King Faisal University and selected high schools in the region. The total number of participants was 1007 with the majority of participants between 15 to 19 years old. Data had shown that a low percentage complied with traffic regulations and the use of seatbelts. A relatively high number of participants lacked the knowledge of important traffic signs, especially signs designated for yielding to traffic and pedestrians, which could be one of the major reasons for the high rate of accidents in the region in combination to excessive speeding. Furthermore, participants agreed that TV programs would be the best method for promoting traffic awareness. In spite of the high usage of the internet by youth, the internet was considered the least effective method. In conclusion, this study showed that youth in Al-Ahsa region had the knowledge of wrong driving practices, but they lacked it in traffic regulations and signs. Therefore, it is recommends that the traffic regulations and safety awareness start at an early stage and age, through TV programs and school activities. In addition, knowledge of traffic signs should be emphasized with the increase of the enforcement of traffic regulations.

Processing water hyacinth into biomass briquettes for cooking purposes.

Abstract: The processing of agricultural wastes into biomass is a strategy towards the development of alternative energy sources. Water hyacinth is an aquatic plant which could be used as an alternative energy source to wood. This paper presents the processing of water hyacinth into biomass briquettes for cooking purposes. The water hyacinth which was harvested, dried and ground into powder was mixed with starch binder before being compressed into briquettes in a manually operated briquetting machine. The briquettes produced were sundried and comparative cooking tests were carried out by burning the briquette in a mold while cooking some food items. Some quantity of Water was boiled and, Indomie, Rice and Yam were cooked. Comparisons of the cooking time obtained were made with the time obtained when the same quantities of foods were cooked on a conventional kerosene stove. Results obtained shows that water hyacinth can be processed into briquettes and used for cooking purposes.

Inhibition of the corrosion of mild steel in acidic medium by Vernonia amygdalina : adsorption and thermodynamics study

Abstract: The inhibitive, thermodynamics and adsorptive properties of ethanol extract of vernonia amygdalina for the corrosion of mild steel in 0.4M HNO3 solutions have been investigated using weight loss technique. The extract was found to be a good inhibitor for corrosion of mild steel in HNO3. Inhibition efficiencies obtained ranged from 40.57 to 50.74% and from 38.06 to 49.27% at 303 and 323K respectively. The inhibition efficiency of the extract decreased as temperature and time of immersion increased, but increased with increase in concentration of extract. The inhibition capacity of this extract is attributed to the presence of saponnin, tannin, alkaloid, anthraquinone, flavanoid, cardiac glycosides in the extract. The heat of adsorption obtained ranged from -48.84 to -51.06KJ mol-1 indicating that adsorption of the inhibitor on surface of mild steel was exothermic, spontaneous and follows the mechanism of physical adsorption. Langmuir, Temkin, Frumkin and Flory-Huggins adsorption isotherms were found to conform the adsorption characteristics of the inhibitor.

Assessment of thermal performance of residential buildings in Ibadan Land, Nigeria

Abstract: Thermal performance and efficiency of buildings are proportional to details of designs of the building, climate responsive design parameters, the use of site, details of microclimate and nature and magnitude of the fabrics. In this study, a field investigation was been carried out on four buildings with different system designs. Estimates of indoor air hourly values of surfaces temperature and environmental temperature were carried out systematically. From the regression analysis, the result showed the R-squared value as 85.2% indicating that there is a very strong relationship among the independent factors (Building types I-IV) on the dependent factor (ambient temperature). The F-value (index of reliability) is significant at 0.000; this implies that the effect of the building types is significant on the ambient temperature. The result also showed that the effect of the individual building type on the ambient temperature rank in the following increasing order: type I, type IV, type III and type II. Building type II had the greatest effect on the ambient temperature. It therefore recommends that provision of plasters on Adobe walls, ceilings, shading, proper positioning of the buildings and increase in the mass contents of the walls of the buildings can improve the thermal comfort of the rest there mass content building types. The paper recommends that adequate consideration must be given to effective building architecture and appropriate finishes operations on walls in order to achieve internal comfort for the occupants.

Flood frequency analysis of Ikpoba River catchment at Benin City using Log Pearson Type III distribution

Abstract: In this study, a flood frequency analysis (FFA) of Ikpoba River Catchment at Benin City, Edo State Nigeria was undertaken using the Log-Pearson Type III probability distribution, one of the numerous probability distribution functions used to model hydrologic phenomena that are characterized by significant variability not deterministically explained by physical principles. The study was motivated by the need for safe and economic hydrologic design and assessments in the catchment area. The log-Pearson type III probability distribution was used to model the annual peak discharge for the river for the period 1989 to 2000 based on stream flow measurements carried out by Benin Owena River Basin Development Authority. The probability distribution function was applied to return periods (T) of T = 2 yrs, 5yrs, 10yrs, 25yrs, 50yrs, 100yrs and 200 yrs commonly used in for engineering design of hydraulic structures. The estimated discharges obtained are 46.34m3/s, 55.84m3/s, 61m3/s, 66.89m3/s, 70.73m3/s, 74.18m3/s and 77.38m3/s respectively. These values are useful for hydraulic design of structures in the catchment area and for storm water management The model which relates the expected discharge(y) to return period is given by y= 6.546ln(x) + 44.4.

The effect of cane molasses on strength of expansive clay soil

Abstract: This paper examines the mechanism of stabilization of expansive soil with cane molasses. The main objective of the study was to establish whether or not sugar cane molasses can be used as a stabilizing agent for expansive clay soil used for engineering purposes. Other objectives were to carry out analysis of cane molasses; to carry out strength assessment of neat expansive soil and expansive soil mixed with cane molasses as reflected by California bearing ratio (CBR). Cane molasses was selected for this purpose because it contained some elements/compounds which are known to react with clay minerals and change characteristics of the soil. It was established that 8% cane molasses by weight of dry soil was the maximum for effective stabilization of expansive clay soil. On comparison lime stabilized soil specimens gave higher CBR values than cane molasses. The conclusion was that the increase in CBR values for expansive soil mixed with cane molasses above those of neat expansive soil was an indication that cane molasses caused the increase in soil strength and therefore it stabilized expansive clay soil. It was also observed that cane molasses mixed with expansive clay soil could reduce swelling tendencies of the soil.

A review on equal channel angular extrusion as a deformation and grain refinement process

Abstract: Equal channel angular extrusion (ECAE) has been known over some years now as a deformation and grain refinement process for materials when pushed more than a couple of times through a die formed from two channels of equal cross-section, intersecting to form a 'sharp' corner. Since its invention in 1977 by V. M. Segal, it has been an essential tool by engineers and scientists for imparting various properties on the extruded material. It should be noted also that its usage gained more prominence in the early 80's. A lot of publications and articles have come up as reports after the use of ECAE on various materials. Various factors have been known to affect the properties and the microstructures of ECAEed materials. Some of these factors include temperature, die corner angle and type of route. This paper gives a concise summary of what ECAE entails as a deformation and grain refinement process. This was achieved after reviewing various articles in refereed journals published worldwide.

Swarm intelligence based detection of malicious beacon node for secure localization in wireless sensor networks

Abstract: Wireless sensor networks (WSNs), made of collection of small, cheap, low power sensors, have diverse applications in several domains of life. Most of their applications demand for spatial position of sensors. Beacon nodes which already know their location are mostly used to help other sensor nodes to locate their position. However localization of sensors in a hostile environment is a crucial issue. The compromised beacon nodes can severely affect the process of localization. The aim of this research is to propose an algorithm to detect malicious beacon nodes based on swarm of intelligent water drops to provide secure localization in wireless senor networks. The paper also critically reviews existing secure localization schemes.

Tensile and compressive strength characteristics of Raffia Palm fibre-cement composites

Abstract: The tensile and compressive strength of raffia palm fiber-cement composites for low cost roofing tiles was investigated. The composites were prepared at varying sand-to-cement ratios (1-5), water-to-cement ratios (0.4-0.8) and fiber volume fraction (0-4%). The tensile and compressive strengths of the samples were determined and a statistical model based on a three-level full factorial experimental study was developed and the significance of all factors and interactions determined. The results show that increasing any of the three factors reduces tensile and compressive strength, with sand-to-cement ratio being the most significant. Tensile and compressive strength have the same local optimum (maximum) at sand-to-cement ratio of 1, water-to-cement ratio of 0.4 and fiber volume fraction of 0%. Raffia palm fiber at low fibre volume fraction and with proper fibre alignment can be used for the manufacture of low cost wall, ceiling and roofing tiles based on the above specification.

Study of an effective technique for the production of biodiesel from jatropha oil

Abstract: This paper presents biodiesel production from non-edible jatropha oil by transesterification process on a bench scale using sodium hydroxide (NaOH) as catalyst for the methanolysis of the jatropha oil. This study evaluated the effect of the concentration of the basic catalyst on the biodiesel yield. The biodiesel was evaluated for fuel properties and compared with the American Society for Testing and Material (ASTM) specification for biodiesel according to its physical, chemical and mechanical properties such as viscosity, flash point, density, sulphur content. The results show that the properties of the biodiesel produced was found to be within the limit of the ASTM specifications for biodiesel. At a catalyst concentration of 0.8%, reaction temperature of 65%, reaction time of 1 hour and methanol to oil molar ratio 5:1, the amount of biodiesel produced was 95.5%.

Performance evaluation of egunsi melon (Citrullus Colocynthis L.) seeds oil biodiesel

Abstract: Oil was extracted from egunsi melon seeds by solhtex extraction method and transesterified to methyl ester using sodium hydroxide as catalyst and methanol to oil molar ratio of 6:1 to give high biodiesel yield. The egunsi melon oil, methyl ester and a blend of 20% biodiesel and 80% diesel were characterized using the ASTM protocols and the properties measured are within the ASTM D6751 limits for biodiesel. Of particular importance is the flash point which makes it a safe fuel for handling and storage. Chromatographic analysis gave 62.36% linoleic, 12.23% oleic, 12.88% palmitic acids as the major constituents. By blending with 80% diesel fuel, the oleic and linoleic acids reduced by 6.46% and 34.72% respectively which will improve oxidation stability of the fuel since both are unsaturated. The fuel was tested in a single cylinder diesel engine and gave torque and power close to those of diesel fuel but the specific fuel consumption was 8% higher and consistent with the difference in their heating values.

Study of rake face action on cutting using palm-kernel oil as lubricant

Abstract: The work investigates the effect of cutting speed, feed rate, depth of cut, and rake angle on main cutting force during the cylindrical turning of mild steel, brass, and aluminum rod, using high speed steel cutting tool and palm-kernel oil as cutting fluid. The impact of lubrication on the coefficient of friction between the chip and rake face during turning operation, assuming a negligible friction between the flank and cut surface is measured. Experimental results show that aluminum at cutting speed of 4.15m/s and rake angle 9o gave a 33.3% reduction in coefficient of friction while brass and mild steel under the same cutting condition gave7.9 and 13.8% increase in coefficient of friction respectively. Findings at cutting speed of 4.15m/s and depth of cut 1.5mm gave 9.79% reduction, 46.7 and 20.8% increase in coefficient of friction for brass, aluminum and mild steel respectively while cutting speed of 4.15m/s and feed 1.8mm/rev gave a 9.2% reduction, 30.4 and 14.5% increase in coefficient of friction for brass, aluminum and mild steel respectively. Similar trend was observed by varying the cutting conditions on the workparts through different selected values. The effect of palm-kernel oil as a metal cutting lubricant is more pronounced on aluminum than brass and mild steel.

Development and evaluation of a melon shelling and cleaning machine

Abstract: Melon seed is very rich in protein and forms an important ingredient in Nigerian soups (Egusi) and vegetable oil industry. The drudgery involved in the manual shelling of the seeds has discouraged the mass production and commercialization of the crop and this necessitates the development and evaluation of a motorized operated melon shelling machine using impact method. Relevant physical properties of the seeds determined were moisture content, size, angle of repose, weight and the terminal velocity. Tests on the sheller were carried out using the main cultivar of melon (Bara) cultivated in Nigeria. The sheller comprises of the hopper which contains the unshelled melon seeds and is opened directly to the shelling chamber. The shelling chamber comprises of the disc and the rotor. The inner part of the chamber is lined with tiny metal rods to give it a rough surface. Flat metal bars are welded around the concave (rotor) at an angle of 45°. The concave is attached directly to a 2-horsepower electric motor which drives it in an anticlockwise direction to shell the melon seeds. The shelled melon seeds and the cotyledon fall directly into the cleaning chamber where an installed fan blow away the chaff and the cotyledons are collected directly through an opening below the shelling chamber. The sheller was constructed from locally available materials and its operation does not require any special skills. Tests were carried out at speeds of 750, 950, 1200 rpm and moisture contents of 7% and 10% (WB). Analysis of Variance (ANOVA) at P ≤ 0.05 and P ≤ 0.01 was used to determine if the moisture content of melon seeds and the rotation of the shelling unit had any significant effect on the shelling capacity, cleaning capacity and the efficiency of the shelling unit. The results of the analysis showed that increase in the speed of the shelling unit increases the shelling and cleaning capacities of the sheller. However, breakages of the shelled melon seeds also increase with an increase in the speed of the shelling unit. When the moisture content of the melon seeds was increased from 7% - 10% there was drastic reduction in the amount of broken seeds from 95% to 3%. The shelling capacity was reduced from 148kg/h to 145kg/h at a concave speed of 1200 rpm, the cleaning capacity also reduced from 52kg/h to 39kg/h at a concave speed of 750 rpm. It could be concluded that melon seeds should not be shelled at a moisture content less than 10% and that the speed of shelling should be about 950 rpm. The efficiency of the sheller is about 90%. The sheller performed satisfactorily and is suitable for domestic and commercial shelling of melon seeds. This will encourage the industrialization of vegetable oil gotten from melon seed processing in Nigeria.

Subsoil evaluation for pre-foundation study using geophysical and geotechnical approach

Abstract: A research approach that integrated geophysical and geotechnical methods for subsoil evaluation using for prefoundation study was carried out in this research paper. The study involved eighteen Vertical Electrical Sounding (VES) using Schlumberger configuration and geotechnical investigation. Three major geoelectric layers were delineated; the topsoil, weathered layer and basement bedrock. The layer resistivity and thickness ranges are 137 - 1559 ohm-m; 189 - 441 ohm-m and 1253- ∞ ohm-m and 0.3 - 2.3 m and 0.9 - 5.4 m for the three layers respectively. The estimated depths to basement bedrock vary from 0.5 - 5.9 m, for most parts of the property, the overburden thickness are generally less than 2.0 m. There are no indications of the major geologic structure such as faults. The percentage passing 0.075mm ranges from 30 - 32%, the plastic index ranges from 16 - 20% and the linear shrinkage ranges from 7 - 8%. The subsoil on or within which civil structures can be founded in the area are composed of mainly clayey sand and laterite with resistivity values generally greater than 250 ohm-m and all the geotechnical parameters fall within specification for subsoil foundation materials. It can be concluded therefore that the subsoil within the study area are generally competent and buried metallic structures within the area are at extremely low risk of being corroded.

Identification of sources of heavy metals pollution in road deposited sediments using multivariate statistical analysis

Abstract: Heavy metals in road sediments have long term and far reaching environmental and health implications, and identification of the sources is the first step to taking mitigating measures. Assessment of toxic metals in the road sediments of Suleja streets was carried out. 30 samples were collected from seven selected streets. The road sediment samples were digested with a mixture of HNO3 and HClO4 (2:1 v/v), and analyzed for the metals Pb, Cu, Cr, Zn, Cd and Ni using Atomic Absorption Spectrophotometer. Results showed that metal concentrations (mg/kg dry weight) were in the following range: Zn (35.00 - 350.00), Pb (5.33 - 115.56), Cu (2.71 - 171.76), Ni (10.00 - 40.00), Cd (2.50 - 66.00), Cr (6.79 - 34.71). Multivariate statistical analysis revealed that Pb and Cr were related to traffic, metal-work stations in the area led to elevated levels of Cd and Ni, while Cu and Zn were from dual origin of vehicular and industrial emissions.

Phytochemical screening and antimicrobial activity of the methanol and chloroform extracts of Alchornea cordifolia

Abstract: The leaves, stem bark and root of Alchornea cordifolia were separately extracted with cold methanol and chloroform. The extracts were then screened for basic phytocompounds and subjected to antimicrobial assays against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Candidas albican. Disc diffusion method was used to determine the antimicrobial activities of the plant extracts. Phytochemical investigation showed the presence of tannins, saponins, anthraquinones, flavonoids, sterols and cardiac glycosides. Few of the extracts contained anthraquinones and alkaloids; while no phlobatannin was detected in all the extracts. The zone of inhibition ranged between 0.5 and 20mm for the entire microorganisms tested. Generally the more polar methanol extracts of the plant exhibited more antimicrobial activity than the less polar chloroform extracts. This was implied by the zone of inhibition of the tested micro-organisms (16.0 - 20.0mm) which demonstrated that the methanol extracts have broad spectrum activity. The chloroform extracts had no inhibitory activity against C. albican and B. subtilis. The results of this study showed that the methanol extracts of the leaves, stem bark and roots of Alchornea cordifolia posses high levels of anti-effective agents. This gives credence to the trado-medicinal application of the plant as remedy for various infections.

Study of physio-mechanical properties of high density polyethylene (HDPE) - palm kernel nut shell (Elaeis guineasis) composites

Abstract: The major objective of this work is to determine the physio-mechanical properties of the proposed polymer composite which is a combination of two distinct materials: HDPE and palm kernel nut shell particulate. The materials compounding and sample formation was done using Reliable Two Roll Mill Model 5183 and Carvers Hydraulic Hot Press. Two composite systems were fabricated. Tensile strength of the fabricated composites was tested using standard equipment in accordance to the ASTM standard specifications; Advanced Material Testing Machine, Resil Tensile-impactor and Quanta 200 Environmental Electron Scanning Microscope. Percentage water absorption of the composite was also investigated. The results obtained showed that tensile properties changed with the filler content. The tensile strength first increased with increase in filler content. At a higher filler load the tensile strength dropped. Composite hardness and % water absorption increased with increase in filler content. Environmental Scanning Electron Microscope (ESEM) showed good filler-matrix interaction. The results obtained showed matrix-filler compatibility especially for the sodium hydroxide treated filler.

Phytochemical and antinutrients evaluation of Oxyporus Populinus

Abstract: Phytochemical and antinutrients analyses of the mushroom, Oxyporus Populinus fruiting bodies were carried out to ascertain its edibility and inedibility status and possible utilization. The phytochemical screening result showed the presence of sterols and triterpenes in large amounts: alkaloids, tannins, saponins and phlobatannins in moderate amounts; as well as carbohydrate and flavonoids in trace amounts. The antinutrients analysis revealed the presence of tannins (10.14 ± 0.15 mg), soluble oxalate (22.89 ± 0.02 mg), insoluble oxalate (140 ± 0.09 mg/100g), phytate ( 61.60 ± 0.09 mg/100g),insoluble oxalate (79.20 ± 0.09 mg/ 100g) and hydrogen cyanide (13.54 ± 0.03 mg/100g) in minute quantities below the lethal doses. However, Oxyporus populinus may be inedible due to its fibrous nature and possible presence of toxins not determined in this study. There is dearth on available literature on the phytochemical, nutrients and antinutrients composition and values of Oxyporus populinus. This paper is therefore aimed at investigating the phytochemical and antinutrients parameters of Oxyporus populinus with a view of filling the information gap. The relevance of these findings are also discussed.

Major ionic composition of Jizan thermal springs, Saudi Arabia

Abstract: Jizan thermal springs are located in the southwestern part of Saudi Arabia. The springs flow through fractures within the Precambrian-Cambrian Arabian Shield rocks that occupy the eastern boundary of the Red Sea Plate boundary. The springs are characterized with temperatures that vary from 40 to 75 degrees Celsius. The groundwater in the area is subjected to sea water intrusion, mixing and dissolution of salts. Depletion of (Ca+Mg) and enrichment of (Na+K) in thermal waters is the result of an interaction of CO2 with water and rocks. In fact, CO2-rich water facilitates Ca-Na exchange processes in feldspars and clay minerals. The thermal springs, having a lower (Cl+SO4)/HCO3 ratio (0.38 to 0.56), higher (Na+K)/(Ca+Mg) ratio (>4) and Cl>SO4, are chemically distinct from the groundwater. The enrichment of Na-HCO3 in thermal spring samples relative to groundwater could, therefore, be a residual feature caused by CaCO3 precipitation at relatively high temperatures within the thermal circuits in which CO2 tends to rise to the surface.

Technological and non-technological factors responsible for the occurrence of collapse buildings in South-Western Nigeria

Abstract: Building is essentially a space that protected man from the natural environment. It must possess adequate strength and every member of structural system should be able to resist without failure or collapse the applied loads under service conditions. It has been observed that following technological advancement and increase passion for housing, there were reports of incessant collapse of building structure. When building collapses either in part or whole, result not only in wasted efforts or investment but also lost of lives. This paper examined the technological and non-technological factors that are responsible for the occurrence of collapses buildings in the southwestern Nigeria. Many factors have been identified as causes of collapsed building. Technological factors include building design, design error, site production, and use of poor materials faulty design foundation among others. While non-technological factors are lack of site-trade training corruption etc. Conclusion and recommendation were made to assist the government in implementing the existing framework to reduce or total elimination of buildings' collapse.

What are they made up of today? A look at engineering education in developing nations with Nigeria as a case study

Abstract: The huge amounts of demolition debris (DD) in Gaza Strip cause environmental, social and economical problems. The socio-economic development in Gaza Strip is also threatened by the depletion of natural aggregates. Such conditions necessitate the use of demolition debris waste (DDW) as aggregates in new concrete mixes. Concrete cylindrical specimens of 250 kg/cm2 characteristic strength made of DD were tested to determine the creep behavior of that concrete. The main variables were the type and percent of replacement of demolition debris aggregates in its saturated surface dry conditions. The study concluded that concrete with natural sand and RA1 (recycled coarse aggregate from crushed concrete fragments only) provided 32.8% higher creep strain than that of natural aggregate concrete while concrete with recycled fine aggregate and RA1 provided 79% higher strain than that of natural aggregate concrete. In addition, concrete with recycled fine aggregates and RA2 (recycled coarse aggregate from all crushed demolition fragments) provided 118% higher creep strain compared to natural aggregate concrete.

Geoelectric delineation of structurally-controlled leachate plume around Otutubiosun dumpsite, Akure, Southwestern Nigeria

Abstract: A direct current electrical resistivity survey using the Schlumberger Vertical Electrical Sounding (VES) and Dipole-Dipole profiling techniques have been used to map structurally controlled pollution plume around the Otutubiosun dumpsite, Akure, southwestern Nigeria. The geoelectric interpretation and the inverted 2-D resistivity structures revealed three subsurface layers: the topsoil, weathered layer and the fractured/fresh basement rock. The fractured/fresh basement constitutes the basement bedrock. The weathered layer and the fractured/faulted zones constitutes the major aquifer units in the study area. Topsoil resistivity and thickness value ranges from 5 - 107 ohm-m and 0.2 - 2.7 m respectively. The weathered layer resistivity values vary from 4 - 35 ohm-m while its thickness ranges from 1.1 - 12.9 m beneath the dumpsite. The depth to the bedrock varies from 2.2 - 13.1 m. The resistivity values of the fractured/fault zones rages from 2 - 55 ohm-m and the thickness varies from 10 - 30 m. The 2-D resistivity structures show that zones with relatively low resistivity values of (l 35 ohm-m) with a depth range of 1.1 - > 15 m for topsoil, weathered layer and fractured/faulted basement zones are suspected to be due to leachate saturation. Due to the observed relatively shallow water table of 0.5 - 2.0 m around the dumpsites the groundwater around the dumpsites is suspected to have been polluted. This study reveals that subsurface geologic structures within the bedrock (fractures/faults) control the migration of leachate plume around the investigated dumpsite.

Estimation of solar radiation at Ibadan, Nigeria

Abstract: This study presents and evaluates the behaviour of three empirical models based on the difference between maximum and minimum temperatures at Ibadan (7° 22'N, 3° 53'E). This was done by using monthly data on solar radiation and minimum and maximum temperature for a period of 6 years, (2001 - 2006). The corresponding monthly value of extraterrestrial solar radiation (Ra) was calculated for each data. Forecasting performance parameters such as coefficient of determination (r2), root mean square error (RMSE), mean bias error (MBE) and mean absolute percentage error (MPE) are presented as analyzed for the models. The Hargreaves model with linear regression has the highest r2 value of 0.72 and lowest RMSE, MBE, and MPE values of 1.59 MJm-2day-1, 0.82 MJm-2day-1 and -7.36% respectively. The best performance for the present data set was found at Hargreaves model with linear regression, and followed by Hargreaves model with power regression and original Hargreaves model. The present result suggested the Hargreaves model with linear regression reasonably predictable global solar radiation and the expected solar radiation behaviour in the area of study.

Development and evaluation of a biomass stove.

Abstract: Locally fabricated biomass stoves have become household items inigeria. The fabricated stoves are usually made by local artisans who have little or no knowledge of engineering principles and methods. A portable "improved cookstove" (ICS) that incorporates a cylindrical ceramic combustion chamber into a framed cylindrical metal casing for cladding and ease of handling was developed and tested in the Department of Agricultural and Environmental Engineering, University of Agriculture Makurdi. A modified University of California water boiling test (WBT) version 4.12 was used for testing of the stove. The results obtained from tests carried out on the improved cookstove were compared with the traditional 3/stone stove. The result of the cold start test indicates that the ICS used an average of 69g of wood to boil 1 liter of water in about 8 min (5 liters in 38 min) as against 326g of wood to boil the same 1 liter of water in about 25 min(5 liters in 126 min) using the 3/stone stove. This indicates that the ICS is superior to the 3/stone stove in specific fuel consumption in the high power (cold start) phase. The average rate of wood consumption (burning rate) was higher for the 3/ stone stove (10.1g/min) than the ICS (6.7 g/min) indicating better performance of over the 3/stone stove. Analysis showed that the performance of the ICS is statistically significant at t 95 but not at t 99 against the 3/stone stove; (burning less wood per unit time to accomplish the same task). The thermal efficiency of the ICS (67%) was better than the 3/stone stove (16%) and statistics at both t 95 and t 99 showed a significant difference of such superiority of the ICS over the 3/stone stove for thermal efficiency. The firepower of the 3/stone fire stove (3422kW) was higher than the ICS (2192kW) which is in agreement with the burning rate as the 3/stone fire consumed more wood per unit time for the same task. The test results of the high power hot start phase showed that the average rate of wood consumption (burning rate) was higher for the 3/stone stove (10.1g/min) than the ICS (3.9 g/min). The firepower of the 3/stone stove (1270kW) was lower than the ICS (3277kW). The average thermal efficiency for this phase was 66% for the ICS and 16% for the 3/stone fire stove. In most aspects of stove performance the ICS was better than the 3/stone fire stove and thus it is recommended for use.

Estimating an optimal backpropagation algorithm for training an ANN with the EGFR exon 19 nucleotide sequence : an electronic diagnostic basis for non-small cell lung cancer (NSCLC)

Abstract: One of the most common forms of medical malpractices globally is an error in diagnosis. An improper diagnosis occurs when a doctor fails to identify a disease or report a disease when the patient is actually healthy. A disease that is commonly misdiagnosed is lung cancer. This cancer type is a major health problem internationally because it is responsible for 15% of all cancer diagnosis and 29% of all cancer deaths. The two major sub-types of lung cancer are; small cell lung cancer (about 13%) and non-small cell lung cancer (%SCLC- about 87%). The chance of surviving lung cancer depends on its correct diagnosis and/or the stage at the time it is diagnosed. However, recent studies have identified somatic mutations in the epidermal growth factor receptor (EGFR) gene in a subset of non-small cell lung cancer (%SCLC) tumors. These mutations occur in the tyrosine kinase domain of the gene. The most predominant of the mutations in all %SCLC patients examined is deletion mutation in exon 19 and it accounts for approximately 90% of the EGFR-activating mutations. This makes EGFR genomic sequence a good candidate for implementing an electronic diagnostic system for %SCLC. In this study aimed at estimating an optimum backpropagation training algorithm for a genomic based A%% system for %SCLC diagnosis, the nucleotide sequences of EGFR’s exon 19 of a noncancerous cell were used to train an artificial neural network (A%%). Several A%% back propagation training algorithms were tested in MATLAB R2008a to obtain an optimal algorithm for training the network. Of the nine different algorithms tested, we achieved the best performance (i.e. the least mean square error) with the minimum epoch (training iterations) and training time using the Levenberg-Marquardt algorithm.

A review on potential reuse of recovered nonmetallic printed circuit board waste

Abstract: In recent years there has been increasing concern about the growing volume of end of life electronics and the fact that much of it is consigned to landfill without any attempt being made to recycle the nonmetallic materials it contains. The production of electric and electronic equipment (EEE) is growing rapidly in most developed countries such as in China, Cambodia, India, Thailand and also in Malaysia. Waste of electric and electronic equipment (WEEE) is significantly increasing. A large amount of nonmetallic materials in printed circuit board (PCBs) are disposed of by combustion and disposal in landfill as the main method for treating nonmetals in PCBs, but it may cause secondary pollution and resource wasting. This paper presents a review on the reclaimation and reuse of nonmetallic materials recovered from waste PCBs. The recovered nonmetals were used to make models, construction materials and composite boards. The PCB nonmetal products have better mechanical characteristics and durability than traditional materials and fillers. Products derived from PCB waste processing have been brought into industrial production. The study shows that PCB nonmetals can be reused in profitable and environmentally friendly ways.