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Nigerian Journal of Technological Development

University of Ilorin, Ilorin Kwara State Nigeria, Faculty of Engineering and Technology, Faculty Member

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The Nigerian Journal of Technological Development is a biannual publication of the Faculty of Engineering & Technology, University of Ilorin, Ilorin, Nigeria. It publishes original high-quality articles focusing on all aspects of Engineering and Applied Sciences. Manuscripts are double-blind peer-reviewed and if found suitable, published according to the subject matter as a Research Paper, Review Paper or a Technical Note.

The journal covers research in the following but not limited to:

Agricultural and Biosystems Engineering
Biomedical Engineering
Chemical Engineering
Civil Engineering
Computer Engineering
Electrical and Electronics Engineering
Food and Bioprocessing Engineering
Materials and Metallurgical Engineering
Mechanical Engineering
Water Resources and Environmental Engineering
Petroleum Engineering
Applied Sciences
Geophysics
Geology
Applied Mathematics
Phone: +2348136961923
Address: Faculty of Engineering and Technology, University of Ilorin, Ilorin, Nigeria

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University of Maiduguri

Dr. Osama M Elmardi

Nile Valley University

Mohamad Andi Pranto

JEAN PIERRE TWAJAMAHORO

JNTU , hyderabad

Akindele Folarin ALONGE

University of Uyo

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Papers by Nigerian Journal of Technological Development

Investigation into the Use of Water Based Brake Fluid for Light Loads

Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

Spatial and Seasonal Variations of Heavy Metal Loads in Uyo Urban Drainage Stream under PS and NPS Pollution

GEO-ELECTRICAL EXPLORATION FOR GROUNDWATER WITHIN THE PREMISES OF UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN, KWARA STATE, NIGERIA

Schlumberger Vertical Electrical Soundings for groundwater search within the premises of Universi... more Schlumberger Vertical Electrical Soundings for groundwater search within the premises of University ofllorin Teaching Hospital(UITH) situated along Ilorin-Jebba road in Kwara state, were carried out with a view to establishing the different subsurface geoelectric layers, the aquifer units· and their hydrogeologic properties. Data were collected from 12 VES stations over· an area of about 500m x 650m. From the quantitative interpretation of the data collected, using the usual method of' curve matching with the Orellana-Mooney Master curves and 1-D forward modeling with WinResist 1.0 version software, four Iithologic units were identified. These include: the topsoil, the lateritic layer, the weathered layer/fractured layer and the fresh basement. The weathered and fractured basement constitutes the main aquifer units. The 2-D resistivity structure has elicited 2 lobes oflow resistivity which constitutes the prospective zone for water in the area. The first lobe exists.below stations 3 and 4 at about 5-15 m depth, with resistivity between 80-14 7 ohm-m and over 300m wide, while the other lobe oflow resistivity which also signifies a possible borehole location exists belOw stations 7, 8 and 9 at a depth of about 2-14 m, with resistivity between 141 ~200 ohm-man~ oy.t!.r.SSO.. . m wide. The study concluded· that the area investigated contains two lobes of low resistivity whi~h could be explored for water supply.

Estimating Runoff and Soil Moisture Deficit in Guinea Savannah Region of Nigeria using Water Balance Method

The estimation ofrunoff and soil moisture deficit in Guinea Savannah region using semi arid model... more The estimation ofrunoff and soil moisture deficit in Guinea Savannah region using semi arid model based on soil water balance technique (SAMBA) was carried out. The input to the SAMBA model are daily rainfall, daily evapotranspiration. type and date of planting of crop, and soi l parameters. The estimated runoff was validated with field measurement taken in a 67.23 ha catchment in the study area. The annual rainfall for the year under study (2009) is 1356.2 mm.· the estimated annual evapotranspiration, runoff and recharge are 638mm, I 32.93mm, and 447.8mm respectively. Recharge was experienced 23 days after a significant depth of rainfall was recorded. For the crop growth in the catchment, the soi l was cropped with a pepper and the growth monitored from the planting to the harvesting. T~e crop enjoyed so much moisture throughout the growing period as Total Available Water in the soil is greater than Soil Moisture Deficit (TAW>SMD). The model results show that the larger percentage of the total annual rainfall was lost to evaporation and recharge during the growing season. The low runoff and high recharge are attributed to soil characteristics of the area and moderate terrain of the study area.

GEO-ELECTRICAL EXPLORATION FOR GROUNDWATER WITHIN THE PREMISES OF UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN, KWARA STATE, NIGERIA

Schlumberger Vertical Electrical Soundings for groundwater search within the premises of Universi... more Schlumberger Vertical Electrical Soundings for groundwater search within the premises of University ofllorin Teaching Hospital(UITH) situated along Ilorin-Jebba road in Kwara state, were carried out with a view to establishing the different subsurface geoelectric layers, the aquifer units· and their hydrogeologic properties. Data were collected from 12 VES stations over· an area of about 500m x 650m. From the quantitative interpretation of the data collected, using the usual method of' curve matching with the Orellana-Mooney Master curves and 1-D forward modeling with WinResist 1.0 version software, four Iithologic units were identified. These include: the topsoil, the lateritic layer, the weathered layer/fractured layer and the fresh basement. The weathered and fractured basement constitutes the main aquifer units. The 2-D resistivity structure has elicited 2 lobes oflow resistivity which constitutes the prospective zone for water in the area. The first lobe exists.below stations 3 and 4 at about 5-15 m depth, with resistivity between 80-14 7 ohm-m and over 300m wide, while the other lobe oflow resistivity which also signifies a possible borehole location exists belOw stations 7, 8 and 9 at a depth of about 2-14 m, with resistivity between 141 ~200 ohm-man~ oy.t!.r.SSO. . . m wide. The study concluded· that the area investigated contains two lobes of low resistivity whi~h could be explored for water supply.

Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

Investigation into the Use of Water Based Brake Fluid for Light Loads

Verification of Some Vegetable Oils as Cutting Fluid for Aluminium

Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil) have been used as ... more Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil) have been used as lubricants in the turning operation of aluminum under varying spindle speeds, feed rates and depths of cut and the results compared with kerosene (due to the gummy nature of aluminium metal). The parameters investigated are the chip thickness ratio, surface finish and surface temperature. Their performances when compared with the conventional soluble oil have shown that they can perform the same functions as imported ones in the machining of aluminum. They reduced chip thickness ratio, improved surface finish and exhibited good cooling behaviour at the work piece-tool interface. This performance is due to their high viscosities and the presence of surface active agents such as stearic acid and halogens, such as chlorine which help to reduce surface energy of a liquid and increase its wetting ability or oiliness.

Video Coding Technique using MPEG Compression Standards

Digital video compression technologies have become part of life, in the way visual information is... more Digital video compression technologies have become part of life, in the way visual information is created, communicated and consumed. Some application areas of video compression focused on the problem of optimizing storage space and transmission bandwidth (BW). The two dimensional discrete cosine transform (2-D DCT) is an integral part of video and image compression, which is used in Moving Picture Expert Group (MPEG) encoding standards. Thus, several video compression algorithms had been developed to reduce the data quantity and provide the acceptable quality standard. In the proposed study, the Matlab Simulink Model (MSM) has been used for video coding/compression. The approach is more modern and reduces error resilience image distortion.

A Method for Solving the Voltage and Torque Equations of the Split-Phase Induction Machines

Single phase induction machines have been the subject of many researches in recent times. The vol... more Single phase induction machines have been the subject of many researches in recent times. The voltage and torque equations which describe the dynamic characteristics of these machines have been quoted in many papers, including the papers that present the simulation results of these model equations. The way and manner in which these equations are solved is not common in literature. This paper presents a detailed procedure of how these equations are to be solved with respect to the split-phase induction machine which is one of the different types of the single phase induction machines available in the market. In addition, these equations have been used to simulate the start-up response of the split phase induction motor on no-load. The free acceleration characteristics of the motor voltages, currents and electromagnetic torque have been plotted and discussed. The simulation results presented include the instantaneous torque-speed characteristics of the Split phase Induction machine. A block diagram of the method for the solution of the machine equations has also been presented.

Tertiary – Recent sediments Terti ary volcanics Cretaceous Benin Flank Cal abar Fl ank Jurassic Younger granites Precambri an Basement Major (reference) town 200 km

This research evaluated the Vertical Electrical Sounding (VES) method of groundwater development ... more This research evaluated the Vertical Electrical Sounding (VES) method of groundwater development in the Basement Complex terrain of West Central Nigeria. It was aimed at verifying the reliability of VES in differentiating lithologies, predicting the depth to basement and probably, aquifer in groundwater development. In doing this, the Schlumberger electrode configuration was employed in the surveys while partial curve matching and computer iteration techniques were used to interpret the curves obtained. In all, seventy three VES were carried out and fourteen boreholes constructed. Comparison was made between the predicted depth to basement from VES and the actual depth from the drilling log. A linear relationship between the actual depth and that predicted by VES was established with coefficient of determination of 0.94 confirming the reliability of the VES method. None of the boreholes drilled was abortive.

Comparison of Cashew Nut Shell Liquid (CNS) Resin with Polyester Resin in Composite Development

Natural resins can compete effectively with the synthetic ones in composite development. In this ... more Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin) so obtained was mixed with cobalt amine (accelerator), methyl ethyl ketone peroxide (catalyst) to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic) resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL) resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa) to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements) and fillers are used in the fibre-reinforced plastic composite developments.

Geological and Electrical Resistivity Sounding of Olokonla Area in North-Central Nigeria

Geological mapping and Electrical resistivity sounding were carried out in Olokonla area in Moro ... more Geological mapping and Electrical resistivity sounding were carried out in Olokonla area in Moro Local Government of Kwara State in order to determine the apparent resistivities of the subsurface lithologies and correlate them with the exposed rocks observed during the geological mapping. The studies also delineate the pattern of fractures in the area which form prefential pathways for ground water. Three vertical electrical soundings (VES) were performed radially adopting the Schlumberger electrode configuration, with half-current electrode separation (AB/2) varying from 1m to 100m. Anisotropy polygon was also constructed based on the radial electrical sounding. The geoelectric parameters revealed five subsurface layers which were interpreted as topsoil, lateritic soil, dry sand soil, weathered granite and granite respectively. The geological mapping showed that the area is underlain by crystalline rocks comprising biotite granite, granite-gneiss and migmatite. The anisotropy polygon showed that a major fracture direction along 60 0 (northeast to southwest) and the coefficient of anisotropy is 0.79. Based on the apparent resistivities and the structural disposition, a potential aquifer was inferred at a depth of 45m. The fracture pattern in the area was constrained to northeast to southwest direction. The data obtained would be useful in borehole drilling for water within the study area.

Assessment of Osmotic Pre-Drying Treatment on Drying Rates of Fresh Tomato Fruits

by Nigerian Journal of Technological Development and Sheref A Bankole

The aim of this work is to investigate the influence of osmotic pre-drying treatments on drying r... more The aim of this work is to investigate the influence of osmotic pre-drying treatments on drying rates of tomato (Lycopersiconesculentum) at various drying temperatures. Fresh Roma tomato fruit samples were sliced to a thickness of 5 mm and the seeds were removed. Weight of 300 g was measured for each of the three replicates and immersed in a hypertonic solution of sucrose of different concentrations 40 and 60 o Brix each held for osmotic duration of 1 and 2 hours, drained for 10 min and then dried at 50, 60, and 70 o C in a mechanical dryer. Control samples were also weighed 300 g per replicate and dried at 50, 60, and 70 o C without pre-drying treatment. The initial moisture content of fresh tomato used was 94.5% (wb). Moisture loss of each sample was monitored and recorded hourly until the product has reached the desired final moisture content (≤ 7%).The data collected were subjected to statistical analysis of variance (ANOVA) and Duncan New Multiple range tests (DNMRT) to ascertain the level of significance differences between the individual treatments and their interaction at p ≤ 0.05.The results show that at all the drying temperatures used, the control tomato samples exhibited the fastest drying rate with an average of 35.2 g/hr, samples pre-treated at 40 o Brix has an average drying rate of 26.6 g/hr, while samples pre-treated at 60 o Brix has the slowest drying rate of 25.2 g/hr. It was also revealed that samples subjected to 1 hour osmotic time have faster drying rates than those treated for 2 hours osmotic time.

Interactive Effect of Air-Water Ratio and Temperature on the Air Stripping of Benzene

High cost of pilot scale studies has led engineers to use simulation to study the factors that af... more High cost of pilot scale studies has led engineers to use simulation to study the factors that affect process performance. This study focuses on the interactive effect of air-water ratio and temperature on the removal of volatile organic compounds from polluted water using packed column air stripper taking benzene as a case study. The process governing equations developed based on two-film model of mass transfer were solved using MATLAB and a surface response plot was done. The mass transfer coefficient increased from 0.1237x10-5 to 0.1932x10-5 s-1 as the temperature was raised from 293 to 323 K. Also, the Henry's constant increased from 228.59 to 883.36 K as the temperature was raised from 293 to 323 K. Benzene removal efficiencies of over 99% were obtained for all combinations of temperature and air-water ratio. The result also indicated that air stripping of benzene from wastewater is most dependent on temperature and moderately on air-water ratio.

Effects of Martensite Development on Lattice Strain Evolution during the In-Situ Loading of Austenitic Stainless Steels at Cryogenic Temperature

The quality assessment of the physical (pH, electrical conductivity, density, writeability, erase... more The quality assessment of the physical (pH, electrical conductivity, density, writeability, eraseability), mechanical (compression test and break strength) and elemental composition of the pencil grades HB, 2B and 3B and eraser types of brand names Ben 10, Tiky 20 and the commonest White eraser in Nigerian primary school (Gummes Co. China) was carried out. The diameter of the graphite part increased in the order HB < 3B < 2B. The pH range of the pencil types was 7.0 -7.4. 2B pencil exhibited the best writeability quality followed by 3B pencil. The compression qualities of the three pencil types were not statistically different (P < 0.01). 3B pencil is the strongest of the pencil types studied, while HB has the least break strength. Cr level by atomic absorption spectrophotometry was lowest in 3B pencil (1.541 µg/g) and highest in 2B (3.700 µg/g). Level of Pb was higher in 2B and HB (4.688 µg/g), while Cd was highest in HB (1.633 µg/g). Fast neutron activation technique indicated that Fe and Zn were elevated compared to the levels of Cr, Cd and Pb in the pencils. The pH range of the eraser brands was 6.2 -7.3. The best eraseability quality was in Tiky 20 and the worst in Ben 10 eraser. The eraser brands contain some heavy metals in the order Pb > Cr > Cd. Though, the levels of the trace metals and essential elements detected in the school items are below the recommended limits, regulatory measures should be directed towards maintaining the standards of school items.

Review of Electrical and Gravity Methods of Near-Surface Exploration for Groundwater

The theory and practice of electrical and gravity methods of geophysics for groundwater explorati... more The theory and practice of electrical and gravity methods of geophysics for groundwater exploration was reviewed with illustrations and data examples. With the goal of reducing cases of borehole/water-well failure attributed to the lack of the knowledge of the methods of geophysics for groundwater exploration and development, the paper reviews the basic concepts, field procedures for data acquisition, data processing, and interpretation as applied to the subject matter. Given a case study of groundwater exploration in University of Ilorin Campus, the three important techniques of electrical method of groundwater exploration are explained and illustrated using field data obtained in a previous study. Interpretation of resistivity data shows that an area measuring low resistivity (high conductivity), having thick pile of unconsolidated rock, and underlained by fracture crystalline is a 'bright spot' for citing borehole for groundwater abstraction in a basement complex area. Further to this, gravity method of groundwater exploration was discussed with field data from Wokbedilo community in Ethopia. Bouguer and reduced gravity anomaly results were presented as maps and contours to demonstrate how gravity data can be inverted to map groundwater aquifers and subsurface geological structures during groundwater exploration.

$Figure 3: Electrical resistivity isotropy and anisotropy. The rule of thumb is that the depth probed is, at best, about 40%-50% of the current electrode separation (Zhody ef al., 1974; Haberjam, 1975). The value decreases with complexity of the local geology. Measured resistivity is plotted with half of the current electrode separation. Azimuthal Electrical Probing (AEP) Technique is used to determine the presence, direction and depth of fractures in rocks. AER is used in combination with VES in crystalline rock terrains where fractures basement rocks are expected to be the source of groundwater aquifer. In AEP, resistivity is measured with depth at different angles (azimuth). Results are plotted with half electrode separation along different azimuth. Deviation from the radial structure (Figure 3a) indicates electrical resistivity anisotropy probably caused by the presence of fracture at subsurface. It shows equipotential surface where electrical resistivity in rock does not change with profile orientation - isotropy. Figures 3b and c show where resistivity changes with profile orientation- anisotropy.$

$Figure 7: Geo-electric cross-section distance around 90m in blue arrow, VES2. Cross-section shows the number of geo-electric layers, thickness and depth of each geo-electric layer and their resistivities. Figure 6: Azimuthal Electrical Probing results showing two episodes of fractures around location 90 m.$

$their interpretations, places around 90m and 180m were recommended for borehole drilling. In this study, the selection of an area for groundwater development (e.g., borehole/well siting) is informed by the presence of low resistivity, presence of thick unconsolidated/weathered rocks and fractures. These three elements are the essential indicators of aquifers system in a crystalline rock terrain.$

Determination of Optimum Moisture Content of Palm Nut Cracking for Efficient Production of Whole Kernel

After processing the palm fruit for oil, the nut is usually dried in order to loosen the kernel f... more After processing the palm fruit for oil, the nut is usually dried in order to loosen the kernel from the shell. The drying is necessary to enhance the release of whole kernel when the nut is cracked. A study was carried out to determine the optimum moisture content of nuts for high yield of whole kernels during cracking. Thirteen identical groups of fresh palm nuts with 240 nuts per group were subjected to oven drying at a temperature of 105 o C. Before starting, the initial mass of each nut was noted and at 2 h-intervals, a group was randomly selected and each of the 240 nuts cracked by impact after weighing for the determination of the nut moisture content. The nuts in the last group were cracked after a drying time of 26 h. The percentage of cracked nuts yielding whole kernels after impact cracking was used to determine the optimum moisture content the average value of which was 2.5% wet basis or 2.57% dry basis. At this moisture content the proportion of evaporable water retained in the intact nuts was estimated to be about of 11.2%. At the optimum moisture content, 84.2% of the cracked nuts yielded whole kernels. The optimum moisture content was obtained after a drying time of about 18 h.

$Figure 3: Whole-kernel yield (%) in relation to nut moisture content (% w.b). A further decrease in the nut evaporable water retained in the nuts from 19.69 to 11.22% (corresponding to moisture content decrease from 4.18 to 2.5% wet basis or from 4.36 to 2.57% dry basis) resulted in gradual increase in the fraction of fully cracked nuts yielding whole kernels (KFC %) from 76.25% to a maximum of 84.20% and thereafter KFC decreased to 78.33% as the % evaporable water in nut decreases from 11.22% to 0% (i.e. moisture content decrease from 2.5% to 0% wet basis or from 2.57% to 0% dry basis). When the fraction of evaporable water in the intact nut was 11.22% (i.e. at nut moisture content of 2.5% wet basis or 2.57% dry basis) the KFC was 84.20% as shown in Figure 3.$

Non-Guard Interval based and Genetic Algorithm Assisted Frequency Domain Equalization for DS-UWB Systems

In this work, a genetic algorithm (GA) based frequency domain equalization (FDE-GA) scheme was pr... more In this work, a genetic algorithm (GA) based frequency domain equalization (FDE-GA) scheme was proposed for direct sequence ultra wideband (DS-UWB) wireless communication systems. The proposed FDE-GA scheme does not require a guard interval (GI) and the output of the RAKE receiver is used as the input to our GA. The scheme achieved much higher bandwidth efficiency than conventional FDE methods because of the removal of the inter block interference (IBI) within each block before the GA. The FDE-GA receiver was shown to significantly outperform the RAKE receiver and the RAKE-GA receiver proposed in a previous work, in terms of bit error rate (BER) at a similar complexity. An improvement in the mean square error (MSE) was observed from simulation results presented, as a result of increase in the number of pilot symbols.

Investigation into the Use of Water Based Brake Fluid for Light Loads

Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

Spatial and Seasonal Variations of Heavy Metal Loads in Uyo Urban Drainage Stream under PS and NPS Pollution

GEO-ELECTRICAL EXPLORATION FOR GROUNDWATER WITHIN THE PREMISES OF UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN, KWARA STATE, NIGERIA

Schlumberger Vertical Electrical Soundings for groundwater search within the premises of Universi... more Schlumberger Vertical Electrical Soundings for groundwater search within the premises of University ofllorin Teaching Hospital(UITH) situated along Ilorin-Jebba road in Kwara state, were carried out with a view to establishing the different subsurface geoelectric layers, the aquifer units· and their hydrogeologic properties. Data were collected from 12 VES stations over· an area of about 500m x 650m. From the quantitative interpretation of the data collected, using the usual method of' curve matching with the Orellana-Mooney Master curves and 1-D forward modeling with WinResist 1.0 version software, four Iithologic units were identified. These include: the topsoil, the lateritic layer, the weathered layer/fractured layer and the fresh basement. The weathered and fractured basement constitutes the main aquifer units. The 2-D resistivity structure has elicited 2 lobes oflow resistivity which constitutes the prospective zone for water in the area. The first lobe exists.below stations 3 and 4 at about 5-15 m depth, with resistivity between 80-14 7 ohm-m and over 300m wide, while the other lobe oflow resistivity which also signifies a possible borehole location exists belOw stations 7, 8 and 9 at a depth of about 2-14 m, with resistivity between 141 ~200 ohm-man~ oy.t!.r.SSO.. . m wide. The study concluded· that the area investigated contains two lobes of low resistivity whi~h could be explored for water supply.

Estimating Runoff and Soil Moisture Deficit in Guinea Savannah Region of Nigeria using Water Balance Method

The estimation ofrunoff and soil moisture deficit in Guinea Savannah region using semi arid model... more The estimation ofrunoff and soil moisture deficit in Guinea Savannah region using semi arid model based on soil water balance technique (SAMBA) was carried out. The input to the SAMBA model are daily rainfall, daily evapotranspiration. type and date of planting of crop, and soi l parameters. The estimated runoff was validated with field measurement taken in a 67.23 ha catchment in the study area. The annual rainfall for the year under study (2009) is 1356.2 mm.· the estimated annual evapotranspiration, runoff and recharge are 638mm, I 32.93mm, and 447.8mm respectively. Recharge was experienced 23 days after a significant depth of rainfall was recorded. For the crop growth in the catchment, the soi l was cropped with a pepper and the growth monitored from the planting to the harvesting. T~e crop enjoyed so much moisture throughout the growing period as Total Available Water in the soil is greater than Soil Moisture Deficit (TAW>SMD). The model results show that the larger percentage of the total annual rainfall was lost to evaporation and recharge during the growing season. The low runoff and high recharge are attributed to soil characteristics of the area and moderate terrain of the study area.

GEO-ELECTRICAL EXPLORATION FOR GROUNDWATER WITHIN THE PREMISES OF UNIVERSITY OF ILORIN TEACHING HOSPITAL, ILORIN, KWARA STATE, NIGERIA

Schlumberger Vertical Electrical Soundings for groundwater search within the premises of Universi... more Schlumberger Vertical Electrical Soundings for groundwater search within the premises of University ofllorin Teaching Hospital(UITH) situated along Ilorin-Jebba road in Kwara state, were carried out with a view to establishing the different subsurface geoelectric layers, the aquifer units· and their hydrogeologic properties. Data were collected from 12 VES stations over· an area of about 500m x 650m. From the quantitative interpretation of the data collected, using the usual method of' curve matching with the Orellana-Mooney Master curves and 1-D forward modeling with WinResist 1.0 version software, four Iithologic units were identified. These include: the topsoil, the lateritic layer, the weathered layer/fractured layer and the fresh basement. The weathered and fractured basement constitutes the main aquifer units. The 2-D resistivity structure has elicited 2 lobes oflow resistivity which constitutes the prospective zone for water in the area. The first lobe exists.below stations 3 and 4 at about 5-15 m depth, with resistivity between 80-14 7 ohm-m and over 300m wide, while the other lobe oflow resistivity which also signifies a possible borehole location exists belOw stations 7, 8 and 9 at a depth of about 2-14 m, with resistivity between 141 ~200 ohm-man~ oy.t!.r.SSO. . . m wide. The study concluded· that the area investigated contains two lobes of low resistivity whi~h could be explored for water supply.

Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

Investigation into the Use of Water Based Brake Fluid for Light Loads

Verification of Some Vegetable Oils as Cutting Fluid for Aluminium

Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil) have been used as ... more Vegetable oils (palm oil, groundnut oil, shear butter oil and cotton seed oil) have been used as lubricants in the turning operation of aluminum under varying spindle speeds, feed rates and depths of cut and the results compared with kerosene (due to the gummy nature of aluminium metal). The parameters investigated are the chip thickness ratio, surface finish and surface temperature. Their performances when compared with the conventional soluble oil have shown that they can perform the same functions as imported ones in the machining of aluminum. They reduced chip thickness ratio, improved surface finish and exhibited good cooling behaviour at the work piece-tool interface. This performance is due to their high viscosities and the presence of surface active agents such as stearic acid and halogens, such as chlorine which help to reduce surface energy of a liquid and increase its wetting ability or oiliness.

Video Coding Technique using MPEG Compression Standards

Digital video compression technologies have become part of life, in the way visual information is... more Digital video compression technologies have become part of life, in the way visual information is created, communicated and consumed. Some application areas of video compression focused on the problem of optimizing storage space and transmission bandwidth (BW). The two dimensional discrete cosine transform (2-D DCT) is an integral part of video and image compression, which is used in Moving Picture Expert Group (MPEG) encoding standards. Thus, several video compression algorithms had been developed to reduce the data quantity and provide the acceptable quality standard. In the proposed study, the Matlab Simulink Model (MSM) has been used for video coding/compression. The approach is more modern and reduces error resilience image distortion.

A Method for Solving the Voltage and Torque Equations of the Split-Phase Induction Machines

Single phase induction machines have been the subject of many researches in recent times. The vol... more Single phase induction machines have been the subject of many researches in recent times. The voltage and torque equations which describe the dynamic characteristics of these machines have been quoted in many papers, including the papers that present the simulation results of these model equations. The way and manner in which these equations are solved is not common in literature. This paper presents a detailed procedure of how these equations are to be solved with respect to the split-phase induction machine which is one of the different types of the single phase induction machines available in the market. In addition, these equations have been used to simulate the start-up response of the split phase induction motor on no-load. The free acceleration characteristics of the motor voltages, currents and electromagnetic torque have been plotted and discussed. The simulation results presented include the instantaneous torque-speed characteristics of the Split phase Induction machine. A block diagram of the method for the solution of the machine equations has also been presented.

Tertiary – Recent sediments Terti ary volcanics Cretaceous Benin Flank Cal abar Fl ank Jurassic Younger granites Precambri an Basement Major (reference) town 200 km

This research evaluated the Vertical Electrical Sounding (VES) method of groundwater development ... more This research evaluated the Vertical Electrical Sounding (VES) method of groundwater development in the Basement Complex terrain of West Central Nigeria. It was aimed at verifying the reliability of VES in differentiating lithologies, predicting the depth to basement and probably, aquifer in groundwater development. In doing this, the Schlumberger electrode configuration was employed in the surveys while partial curve matching and computer iteration techniques were used to interpret the curves obtained. In all, seventy three VES were carried out and fourteen boreholes constructed. Comparison was made between the predicted depth to basement from VES and the actual depth from the drilling log. A linear relationship between the actual depth and that predicted by VES was established with coefficient of determination of 0.94 confirming the reliability of the VES method. None of the boreholes drilled was abortive.

Comparison of Cashew Nut Shell Liquid (CNS) Resin with Polyester Resin in Composite Development

Natural resins can compete effectively with the synthetic ones in composite development. In this ... more Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin) so obtained was mixed with cobalt amine (accelerator), methyl ethyl ketone peroxide (catalyst) to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic) resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL) resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa) to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements) and fillers are used in the fibre-reinforced plastic composite developments.

Geological and Electrical Resistivity Sounding of Olokonla Area in North-Central Nigeria

Geological mapping and Electrical resistivity sounding were carried out in Olokonla area in Moro ... more Geological mapping and Electrical resistivity sounding were carried out in Olokonla area in Moro Local Government of Kwara State in order to determine the apparent resistivities of the subsurface lithologies and correlate them with the exposed rocks observed during the geological mapping. The studies also delineate the pattern of fractures in the area which form prefential pathways for ground water. Three vertical electrical soundings (VES) were performed radially adopting the Schlumberger electrode configuration, with half-current electrode separation (AB/2) varying from 1m to 100m. Anisotropy polygon was also constructed based on the radial electrical sounding. The geoelectric parameters revealed five subsurface layers which were interpreted as topsoil, lateritic soil, dry sand soil, weathered granite and granite respectively. The geological mapping showed that the area is underlain by crystalline rocks comprising biotite granite, granite-gneiss and migmatite. The anisotropy polygon showed that a major fracture direction along 60 0 (northeast to southwest) and the coefficient of anisotropy is 0.79. Based on the apparent resistivities and the structural disposition, a potential aquifer was inferred at a depth of 45m. The fracture pattern in the area was constrained to northeast to southwest direction. The data obtained would be useful in borehole drilling for water within the study area.

Assessment of Osmotic Pre-Drying Treatment on Drying Rates of Fresh Tomato Fruits

by Nigerian Journal of Technological Development and Sheref A Bankole

The aim of this work is to investigate the influence of osmotic pre-drying treatments on drying r... more The aim of this work is to investigate the influence of osmotic pre-drying treatments on drying rates of tomato (Lycopersiconesculentum) at various drying temperatures. Fresh Roma tomato fruit samples were sliced to a thickness of 5 mm and the seeds were removed. Weight of 300 g was measured for each of the three replicates and immersed in a hypertonic solution of sucrose of different concentrations 40 and 60 o Brix each held for osmotic duration of 1 and 2 hours, drained for 10 min and then dried at 50, 60, and 70 o C in a mechanical dryer. Control samples were also weighed 300 g per replicate and dried at 50, 60, and 70 o C without pre-drying treatment. The initial moisture content of fresh tomato used was 94.5% (wb). Moisture loss of each sample was monitored and recorded hourly until the product has reached the desired final moisture content (≤ 7%).The data collected were subjected to statistical analysis of variance (ANOVA) and Duncan New Multiple range tests (DNMRT) to ascertain the level of significance differences between the individual treatments and their interaction at p ≤ 0.05.The results show that at all the drying temperatures used, the control tomato samples exhibited the fastest drying rate with an average of 35.2 g/hr, samples pre-treated at 40 o Brix has an average drying rate of 26.6 g/hr, while samples pre-treated at 60 o Brix has the slowest drying rate of 25.2 g/hr. It was also revealed that samples subjected to 1 hour osmotic time have faster drying rates than those treated for 2 hours osmotic time.

Interactive Effect of Air-Water Ratio and Temperature on the Air Stripping of Benzene

High cost of pilot scale studies has led engineers to use simulation to study the factors that af... more High cost of pilot scale studies has led engineers to use simulation to study the factors that affect process performance. This study focuses on the interactive effect of air-water ratio and temperature on the removal of volatile organic compounds from polluted water using packed column air stripper taking benzene as a case study. The process governing equations developed based on two-film model of mass transfer were solved using MATLAB and a surface response plot was done. The mass transfer coefficient increased from 0.1237x10-5 to 0.1932x10-5 s-1 as the temperature was raised from 293 to 323 K. Also, the Henry's constant increased from 228.59 to 883.36 K as the temperature was raised from 293 to 323 K. Benzene removal efficiencies of over 99% were obtained for all combinations of temperature and air-water ratio. The result also indicated that air stripping of benzene from wastewater is most dependent on temperature and moderately on air-water ratio.

Effects of Martensite Development on Lattice Strain Evolution during the In-Situ Loading of Austenitic Stainless Steels at Cryogenic Temperature

The quality assessment of the physical (pH, electrical conductivity, density, writeability, erase... more The quality assessment of the physical (pH, electrical conductivity, density, writeability, eraseability), mechanical (compression test and break strength) and elemental composition of the pencil grades HB, 2B and 3B and eraser types of brand names Ben 10, Tiky 20 and the commonest White eraser in Nigerian primary school (Gummes Co. China) was carried out. The diameter of the graphite part increased in the order HB < 3B < 2B. The pH range of the pencil types was 7.0 -7.4. 2B pencil exhibited the best writeability quality followed by 3B pencil. The compression qualities of the three pencil types were not statistically different (P < 0.01). 3B pencil is the strongest of the pencil types studied, while HB has the least break strength. Cr level by atomic absorption spectrophotometry was lowest in 3B pencil (1.541 µg/g) and highest in 2B (3.700 µg/g). Level of Pb was higher in 2B and HB (4.688 µg/g), while Cd was highest in HB (1.633 µg/g). Fast neutron activation technique indicated that Fe and Zn were elevated compared to the levels of Cr, Cd and Pb in the pencils. The pH range of the eraser brands was 6.2 -7.3. The best eraseability quality was in Tiky 20 and the worst in Ben 10 eraser. The eraser brands contain some heavy metals in the order Pb > Cr > Cd. Though, the levels of the trace metals and essential elements detected in the school items are below the recommended limits, regulatory measures should be directed towards maintaining the standards of school items.

Review of Electrical and Gravity Methods of Near-Surface Exploration for Groundwater

The theory and practice of electrical and gravity methods of geophysics for groundwater explorati... more The theory and practice of electrical and gravity methods of geophysics for groundwater exploration was reviewed with illustrations and data examples. With the goal of reducing cases of borehole/water-well failure attributed to the lack of the knowledge of the methods of geophysics for groundwater exploration and development, the paper reviews the basic concepts, field procedures for data acquisition, data processing, and interpretation as applied to the subject matter. Given a case study of groundwater exploration in University of Ilorin Campus, the three important techniques of electrical method of groundwater exploration are explained and illustrated using field data obtained in a previous study. Interpretation of resistivity data shows that an area measuring low resistivity (high conductivity), having thick pile of unconsolidated rock, and underlained by fracture crystalline is a 'bright spot' for citing borehole for groundwater abstraction in a basement complex area. Further to this, gravity method of groundwater exploration was discussed with field data from Wokbedilo community in Ethopia. Bouguer and reduced gravity anomaly results were presented as maps and contours to demonstrate how gravity data can be inverted to map groundwater aquifers and subsurface geological structures during groundwater exploration.

$Figure 3: Electrical resistivity isotropy and anisotropy. The rule of thumb is that the depth probed is, at best, about 40%-50% of the current electrode separation (Zhody ef al., 1974; Haberjam, 1975). The value decreases with complexity of the local geology. Measured resistivity is plotted with half of the current electrode separation. Azimuthal Electrical Probing (AEP) Technique is used to determine the presence, direction and depth of fractures in rocks. AER is used in combination with VES in crystalline rock terrains where fractures basement rocks are expected to be the source of groundwater aquifer. In AEP, resistivity is measured with depth at different angles (azimuth). Results are plotted with half electrode separation along different azimuth. Deviation from the radial structure (Figure 3a) indicates electrical resistivity anisotropy probably caused by the presence of fracture at subsurface. It shows equipotential surface where electrical resistivity in rock does not change with profile orientation - isotropy. Figures 3b and c show where resistivity changes with profile orientation- anisotropy.$

$Figure 7: Geo-electric cross-section distance around 90m in blue arrow, VES2. Cross-section shows the number of geo-electric layers, thickness and depth of each geo-electric layer and their resistivities. Figure 6: Azimuthal Electrical Probing results showing two episodes of fractures around location 90 m.$

$their interpretations, places around 90m and 180m were recommended for borehole drilling. In this study, the selection of an area for groundwater development (e.g., borehole/well siting) is informed by the presence of low resistivity, presence of thick unconsolidated/weathered rocks and fractures. These three elements are the essential indicators of aquifers system in a crystalline rock terrain.$

Determination of Optimum Moisture Content of Palm Nut Cracking for Efficient Production of Whole Kernel

After processing the palm fruit for oil, the nut is usually dried in order to loosen the kernel f... more After processing the palm fruit for oil, the nut is usually dried in order to loosen the kernel from the shell. The drying is necessary to enhance the release of whole kernel when the nut is cracked. A study was carried out to determine the optimum moisture content of nuts for high yield of whole kernels during cracking. Thirteen identical groups of fresh palm nuts with 240 nuts per group were subjected to oven drying at a temperature of 105 o C. Before starting, the initial mass of each nut was noted and at 2 h-intervals, a group was randomly selected and each of the 240 nuts cracked by impact after weighing for the determination of the nut moisture content. The nuts in the last group were cracked after a drying time of 26 h. The percentage of cracked nuts yielding whole kernels after impact cracking was used to determine the optimum moisture content the average value of which was 2.5% wet basis or 2.57% dry basis. At this moisture content the proportion of evaporable water retained in the intact nuts was estimated to be about of 11.2%. At the optimum moisture content, 84.2% of the cracked nuts yielded whole kernels. The optimum moisture content was obtained after a drying time of about 18 h.

$Figure 3: Whole-kernel yield (%) in relation to nut moisture content (% w.b). A further decrease in the nut evaporable water retained in the nuts from 19.69 to 11.22% (corresponding to moisture content decrease from 4.18 to 2.5% wet basis or from 4.36 to 2.57% dry basis) resulted in gradual increase in the fraction of fully cracked nuts yielding whole kernels (KFC %) from 76.25% to a maximum of 84.20% and thereafter KFC decreased to 78.33% as the % evaporable water in nut decreases from 11.22% to 0% (i.e. moisture content decrease from 2.5% to 0% wet basis or from 2.57% to 0% dry basis). When the fraction of evaporable water in the intact nut was 11.22% (i.e. at nut moisture content of 2.5% wet basis or 2.57% dry basis) the KFC was 84.20% as shown in Figure 3.$

Non-Guard Interval based and Genetic Algorithm Assisted Frequency Domain Equalization for DS-UWB Systems

In this work, a genetic algorithm (GA) based frequency domain equalization (FDE-GA) scheme was pr... more In this work, a genetic algorithm (GA) based frequency domain equalization (FDE-GA) scheme was proposed for direct sequence ultra wideband (DS-UWB) wireless communication systems. The proposed FDE-GA scheme does not require a guard interval (GI) and the output of the RAKE receiver is used as the input to our GA. The scheme achieved much higher bandwidth efficiency than conventional FDE methods because of the removal of the inter block interference (IBI) within each block before the GA. The FDE-GA receiver was shown to significantly outperform the RAKE receiver and the RAKE-GA receiver proposed in a previous work, in terms of bit error rate (BER) at a similar complexity. An improvement in the mean square error (MSE) was observed from simulation results presented, as a result of increase in the number of pilot symbols.