Showing papers in "Nigerian Journal of Technological Research in 2013"
TL;DR: In this article, a generalized discrete cosine transform with three parameters was proposed and its orthogonality was proved for some new cases, and a new type of discrete W transform was proposed.
Abstract: The discrete cosine transform (DCT), introduced by Ahmed, Natarajan and Rao, has been used in many applications of digital signal processing, data compression and information hiding. There are four types of the discrete cosine transform. In simulating the discrete cosine transform, we propose a generalized discrete cosine transform with three parameters, and prove its orthogonality for some new cases. A new type of discrete cosine transform is proposed and its orthogonality is proved. Finally, we propose a generalized discrete W transform with three parameters, and prove its orthogonality for some new cases. Keywords: Discrete Fourier transform, discrete sine transform, discrete cosine transform, discrete W transform Nigerian Journal of Technological Research , vol7(1) 2012
79 citations
TL;DR: In this article, the authors address the complex issue of food security with a particular focus on soil, highlighting the need to protect this high quality land and highlight the functions of soil and a number of threats to the soil and hence its ability to produce food.
Abstract: This paper addresses the complex issue of food security with a particular focus on soil. The increasing population and changing dietary habits (a shift to a more meat based diet) have placed increasing demands on the small proportion of global soils suitable for food production. The need to protect this high quality land is highlighted. The functions of soil are highlighted and a number of threats to the soil and hence its ability to produce food are identified and discussed briefly. Whilst all these threats are important of particular significance is the loss of soil through sealing linked to urbanisation and associated infrastructure developments. A threat impacting on food security strongly in Africa is nutrient mining where insufficient nutrients are returned to the soil after crop production. The impacts of global change on food security and the potential impacts of global markets for food and land are also briefly discussed. Nigerian Journal of Technological Research vol 7 (3) 2012
20 citations
TL;DR: In this article, a multilayer perceptron neural network model was used to predict the compressive strength of concrete made from coarse aggregate component from Nigeria, and the results showed that the neural network predicted better than the regression model.
Abstract: Cases of collapsed buildings and structures are prevalent in Nigeria. In most of these cases the cause of the collapse could be traced to the strength of the construction materials, mainly concrete. Secondly, experimental determination of the strength of concrete materials used in buildings and structures is quite expensive and time consuming. This research seeks to develop a computational model based on artificial neural networks for the determination of the compressive strength of concrete materials made from a prevalent coarse aggregate component from Nigeria. The study involved building a multilayer perceptron neural network model which was trained using experimental data obtained from compressive strength test of concrete made from unwashed gravel. Compressive strength predictions were compared with alternative model based on regression analysis. Results show that for the unwashed gravel based concrete the regression model prediction has a sum of squares error of 9.808 and a mean absolute percentage (relative) error of 1.167, while the neural network model prediction has a sum of squares error of 0.025 and a mean absolute percentage (relative) error of 0.015. Generally, the models predicted well, but the neural network model predicted better than the regression model. This study has ably demonstrated a cheap, simple, very quick and accurate alternative to experimental method of concrete strength determination. It is simpler and quicker than analytical methods based on regression analysis. Keywords: Artificial Neural Network, Concrete, Unwashed gravel, Regression, Modelling Nigerian Journal of Technological Research , 18(2), 2013
13 citations
TL;DR: In this article, the authors present the design and construction of a microcontroller-based solar panel tracking system, which allows more energy to be produced because the solar array is able to remain aligned to the sun.
Abstract: Solar energy is rapidly gaining popularity as an important means of expanding renewable energy resources. As such, it is vital that those in engineering fields understand the technologies associated with this area. This paper presents the design and construction of a microcontroller-based solar panel tracking system. Solar tracking allows more energy to be produced because the solar array is able to remain aligned to the sun. A working system will ultimately be demonstrated to validate the design. Problems and possible improvements will also be presented. Key Words: Solar, Tracking, Microcontroller, photocells, drivers, single axis.
9 citations
TL;DR: A review of recent developments in utilization of organic and organomineral fertilizers in Nigeria can be found in this paper, where the use of two sources has synergistic effect and reduces expenditure on scarce and expensive mineral fertilizers.
Abstract: The work is a review of recent developments in utilization of organic and organomineral fertilizers in Nigeria. Integrated crop nutrition entails combined use of organic and inorganic fertilizers to avoid problems associated with sole use of the two sources. The aim is also to reduce need and cost associated with sole use of either source of plant nutrients. Researches conducted on effectiveness of organomineral fertilizers show the following: Organomineral fertilizers (OMF) gave similar or higher crop yield compared with recommended NPK fertilizer. They also improved nutritional quality and nutrient content and had residual effect than inorganic fertilizer. The OMF also had liming effect. The OMF reduced need for both organic and inorganic fertilizers which had synergistic effect on each other The OMF improved soil physical properties compared with inorganic fertilizers as indicated by reduction in bulk density, temperature and conservation of soil moisture. The OMF improved soil organic matter, nutrient content and increased availability of cations compared with I norganic fertilizer. Organic wastes that were found to be effective in increasing soil nutrients contents, pH, nutrient uptake by crops and were successfully combined with inorganic fertilizers such as NPK, urea at reduced rates include poultry manure, oil palm bunch ash, cocoa pod ash, kola pod ash and sawdust ash. The pacesetter and sunshine organic and organomineral fertilizers developed and manufactured in Nigeria have been found to be effective in improving soil fertility, and yield of arable and tree crops. There are abundant organic wastes that could be used alone or combined with mineral fertilizers. The presence of organic manures in organomineral fertilizers ensures more residual effect, balanced nutrition and improvement in soil physicochemical properties. The use of two sources has synergistic effect and reduces expenditure on scarce and expensive mineral fertilizers. it is a sustainable approach to ensuring high soil productivity and crop yield. Nigerian Journal of Technological Research
7 citations
TL;DR: In this article, the nutritional compositions and antioxidant properties of six typical Urhobo (Nigerian) soups; Amiedi (Elaeis guineensis extract), Palm oil (Oghwo-evwri), Egusi (Citrullus lanatus) and Okro (Abelmoschus esculentus) soup (Emuigari-ishavwo) were investigated.
Abstract: In this study, the nutritional compositions and antioxidant properties of six typical Urhobo (Nigerian) soups; Amiedi (Elaeis guineensis extract), Palm oil (‘Oghwo-evwri’), Egusi (Citrullus lanatus)–Okro (Abelmoschus esculentus) soup (‘Emuigari-ishavwo’), Pepper (Iribo-erhare), Egusi-vegetable (‘Emuigarifo’), and Egusi-Pepper (‘Ovwovwo’) were investigated. The results show that the typical Urhobo soups were rich in protein and contained extremely low concentrations of reducing sugars. The highest concentrations of high density lipoprotein (HDL)-cholesterol (7.35 ± 0.25 mg/ml), low density lipoprotein (LDL)-cholesterol (1.19 ± 0.67 mg/ml), and triglycerides (6.67 ± 0.29 mg/ml) were observed in ‘Ovwovwo’, ‘Amiedi’ and ‘Emuigari ishavwo’, respectively. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay results showed that all the soup samples exhibit high antioxidant properties. Also, the highest radical scavenging effect was observed in Amiedi and Emuigari-ishavwo soups. The high amount of phenolic and flavonoid compounds in the soups is a measure of their antioxidant capacities. The soups are not only nutritious but also health protective. Keywords: Typical Urhobo soups, Nutritional compositions, Phenols, Flavonoids, DPPH radical, Antioxidant activity Nigerian Journal of Technological Research , 8(2), 2013
6 citations
TL;DR: In this article, the bacteriological quality of packaged water at point-of-sale in Minna, North central Nigeria with emphasis on the incidence of pathogenic bacteria in samples tested.
Abstract: The sale and consumption of packaged water is increasing by the day in Nigeria and this increase is attributed to the fact that there is inadequate supply of portable water in urban areas. This study investigated the bacteriological quality of packaged water at point-of-sale in Minna, North central Nigeria with emphasis on the incidence of pathogenic bacteria in samples tested. Twenty samples comprising 5 bottled and 15 sachet water brands purchased randomly all over Minna city were analyzed for presence of bacterial indicators of water quality. Standard microbiological procedures were used to investigate incidence of pathogenic bacteria such as Salmonella shigella and indicator faecal coliforms. Results showed that 60% of the sachet water samples examined were either untreated or produced under unhygienic conditions. However, all the bottled water analyzed tested negative to E coli, total coliform, Salmonella shigella and total bacteria count. Most of the sachet water brands fell below SON, NAFDAC and WHO drinking water standards and are therefore of doubtful quality. Efforts need being intensified in the monitoring of activities in this rapidly expanding industry with a view to raising standards of its purity for consumption. Nigerian Journal of Technological Research , vol 7(1) 2012
5 citations
TL;DR: In this article, the authors investigated the biomass yield of G. lucidum in submerged culture on account of its requirements for sources of carbon, nitrogen and the carbon : nitrogen (C:N) ratio.
Abstract: Biomass yield of G. lucidum in submerged culture was investigated on account of its requirements for sources of carbon, nitrogen and the carbon : nitrogen (C:N) ratio. The study was carried out with the culture medium of potato dextrose broth enriched with the different carbon (glucose, maltose, starch) and nitrogen (aspartic acid, nitrogen nitrate, peptone) sources over a period of 15 days following standard procedures. The highest biomass of 460±89mg was recorded in the broth medium incorporated with maltose which is significantly different (p<0.05) from that of glucose, 310±89mg, and lactose, 250±50mg. There was no growth on starch (0.00±0.000mg) while the control recorded 114±20mg. The highest biomass of 200±39mg among the nitrogen sources was recorded in the medium incorporated with aspartic acid which is also significantly different(p<0.05) from that of peptone, nitrogen nitrate and the control. A carbon : nitrogen (C:N) ratio (i.e. maltose : aspartic acid) source of 2:2 supported the highest biomass when compared to other carbon : nitrogen ratios. It was therefore deduced, that the presence of maltose as a source of carbon and aspartic acid as a source of nitrogen respectively favoured a good growth of G. lucidum when supplied in a definite amount and ratio. The implications and reasons for these results were highlighted and discussed. It was concluded therefore, that various carbon and nitrogen sources and certain carbon : nitrogen (C:N) ratio have effect on the biomass yield of G. lucidum grown in Potato dextrose broth medium. The findings of this study will be an addition to the baseline information for the growth of the mushroom in submerged cultures for its pharmacological and medicinal potentials. Keywords: Nitrogen source, Carbon source, Biomass, Ganoderma lucidum, Broth medium Nigerian Journal of Technological Research , 8(2), 2013
5 citations
TL;DR: In this paper, the effect of exogenously applied salicylic acid (SA, 0.1 mM) on plant growth parameters, compatible solutes (proline, glycinebetaine) accumulation and on proline metabolism, in leaves and roots of Chamomile recutita plants grown in saline and non-saline control was investigated.
Abstract: The effect of exogenously applied salicylic acid (SA, 0.1 mM) on plant growth parameters, compatible solutes (proline, glycinebetaine) accumulation and on proline metabolism, in leaves and roots of Chamomile recutita plants grown in saline and non-saline control was investigated. Exogenously applied SA resulted increased plant growth significantly both in saline and non-saline conditions. The magnitude of increase in free proline accumulation was significantly increased in presence of NaCl but highly significant was found with the addition of SA to NaCl in leaves. Proline was found .5.3 folds increased in leaves and .1.3 folds only in root in presence of both treatments NaCl+SA with age of plant growth over that of non-saline control. Leaves tissue always maintained higher level of free proline contents than the roots. Anabolic enzymes such as pyrroline-5-carboxylate reductase and .-glutamyl kinase activities increased in all three treatments than the non-saline control and the magnitude of increase was found more pronounced in presence of both treatments than the others. In other way catabolic enzyme, proline oxidase activity was inhibited in all treatments. Nevertheless, the reduction in the activity was more in presence of both treatments than the others. Therefore, during the exogenously applied SA to salt stress, proline metabolism was significantly altered and the extent of alteration varied between the SA and salt stress, leading to the maintenance of the turgor by accumulating higher levels of free proline accumulation in C. recutita, supporting its protection from salt stress. Further, with addition of SA to salt of C. recutita was evident from the higher level of glycinebetaine (GB) compared with non-saline control or/others treatments. The enhanced activities of P-5-CR & .-glutamyl kinase, and proline content in response to NaCl and/or SA treatment, whereas their interaction had an additive/cumulative effect. Hence, SA could be used as a potential growth regulator to improve plant salt stress tolerance. It was, therefore, concluded that SA ameliorated the stress generated by salt through the alleviated proline metabolic pathway/system. Keywords - Chamomile recutita; Compatible osmolytes; glycinebetaine; osmotic pressure; proline; salicylic acid; salinity.
4 citations
TL;DR: It was concluded that spurred (sI) birds in zone C performed relatively better in most of the parameters measured and were significantly (P<0.01) heavier than those in zone A and zone B.
Abstract: A study on the frequency and effect of spur gene (sI) on some metric parameters in the Nigerian local chicken was conducted on 750 adult free range indigenous chickens brought to the market for sale in the three administrative zones of Niger state, Nigeria. The parameters measured were body weight (BL), body length (BL), body girth (BG), wing length (WL), shank length (SL) and shank thickness (ST). The result shows that the calculated gene frequencies of 0.87, 0.89 and 0.90 were significantly (P<0.05) higher than the expected Mendelian frequency of 0.75 for dominant alleles. Spurred (sI) birds in zone C were significantly (P<0.01) heavier (2.19kg) than those in zone A (1.58kg) and zone B (1.50kg). Spurred birds from zone C were also significantly (P<0.01) longer (43.8cm), had better body girth (26.1cm), wing length (24.5cm), shank length (11.7cm) and shank thickness (1.23cm) respectively. It was concluded that spurred (sI) birds in zone C performed relatively better in most of the parameters measured. Keywords : Spur, metric parameters, Nigerian local chicken, frequency.
3 citations
TL;DR: The Boyer Moore type algorithms: Smith, Raita and Quick Search, are extended to solve the parameterized string matching problem by using the q-gram and it is found that Smith algorithm perform better than FPBMH algorithm.
Abstract: In the molecular biology, it is said that two biological sequences tend to have similar properties if they have similar 3-D structures. Hence, it is very important to find not only similar sequences in the string sense, but also structurally similar squences from the database. Parameterized string matchin has been used to find structurally similar sequences from the database. In the parameterized string matching problem, a given pattern P is said to match with a sub-string t of the text T, if there exist a bijection from the symbols of P to the symbols of t. Salmela and Tarhio solve the parameterized string matching problem in sub-linear time by applying the concept of q-gram in the Horspool algorithm (FPBMH). In this paper, we extend the Boyer Moore type algorithms: Smith, Raita and Quick Search, to solve the same problem by using the q-gram. We compare the performance of: FPBMH, Smith, Raita, and Quick search algorithms on DNA alphabet and found that Smith algorithm perform better than FPBMH algorithm. Keywords : Algorithm, prev-encoding, parameterized matching, molecular biology, and RGF String.
TL;DR: In this paper, a two-stage simple random sampling technique was employed in collecting data from a total of 425 rural households out of which responses from 411 rural households were used for the study, and the main tools of analysis used for this study were descriptive statistics and the Linearized-Almost Ideal Demand System (LA-AIDS) model.
Abstract: In spite of the importance of food as a basic human need and major source of nutrients needed for human existence, the effect of high inflation rate on agricultural and food prices has been excruciating. This has in turn affected the poverty level of different households. There is however little information about food demand structure required for appropriate public policy and action for eliminating poverty and endemic malnutrition. This study was therefore designed to assess food demand among rural households in Kwara State. Specifically, the study determined rural households’ food demand; examined the factors that influence rural households’ food demand; and estimated rural households’ food demand elasticities A two-stage simple random sampling technique was employed in collecting data from a total of 425 rural households out of which responses from 411 rural households were used for the study. The main tools of analysis used for this study were descriptive statistics and the Linearized-Almost Ideal Demand System (LA-AIDS) model. The study reveals that roots/tubers, cereals and animal products constituted about 20% each of the budget share of the rural households’ food expenditure. The Linearized-Almost Ideal Demand System shows that food prices, real food expenditure, household size, dependency ratio, place of agriculture as a source of income, farm, size, crop output, household highest educational level and rural households’ food security status were the major factors affecting food demand among rural households in Kwara State.. The study further shows that cereals, fats/oils and vegetables with the expenditure elasticities that were positive but less than 1 could be classified as necessity goods while fruits with expenditure elasticity greater than 1 could be classified as luxury good. Contrary to the law of demand, this study shows that the demand for animal products and fats/oil increased with increase in their prices. In view of the importance of education to food demand, this study recommends the need to intensify efforts at making basic education compulsory in the rural areas. The study also reiterated the importance of increased food production through better access to extension service delivery, agricultural production cum processing facilities as well as the inclusion of increased cereals, roots/tubers and livestock production as priority areas in the agricultural reform programme of the Kwara State government. Keywords: Food Demand, Rural Households, Food Classes, Budget Share, Linearized -Almost Ideal Demand System Nigerian Journal of Technological Research
TL;DR: The findings showed that both sole (cacao pod compost only) and complementary applications of these amendments at 5.0 t/ha significantly enhanced both the growth and the yield of soybean.
Abstract: pot experiment was carried out in the greenhouse at Obafemi Awolowo University Ile-Ife, Nigeria, to assess the effects of composted cacao pod (at the rates of 0, 25 and 5 t/ha, respectively) with and without starter N (25 kg/ha as urea) and P (26 kg/ha as SSP) on the growth and seed yield of soybeans planted on an ultisol The experiment, comprising two set-ups, lasted 8 weeks (for the growth assessment) and 12 weeks (for the yield assessment) The residual effects of the treatments in each set-up were also assessed Results from the first set-up showed that starter N and P significantly (p<005) enhanced soybean heights over the control as well as over the 50 t/ha cacao pod containing N and P The treatments, however, had no significant effect on growth parameters such as number of leaves per plant, shoot dry weight and root dry weight In the residual study, the highest residual effect was realized on number of leaves and shoot dry weight when 50 t/ha cacao pod compost was applied, while the least were produced in the control In the second set-up, only the residual effect of 50 t/ha cacao pod compost + starter N and P, was significant on soybean yield parameters (number of pods, and pod and seed weight) The findings from this study showed that both sole (cacao pod compost only) and complementary (cacao-pod compost + starter N and P) applications of these amendments at 50 t/ha significantly enhanced both the growth and the yield of soybean Keywords: cacao-pod compost, ultisol, starter N and P Nigerian Journal of Technological Research
TL;DR: In this paper, a study was initiated to evaluate changes in the plasticity characteristics and related geotechnical properties of lateritic soil treated with low percent bentonite (up to 10% by dry weight of soil).
Abstract: This study was initiated to evaluate changes in the plasticity characteristics and related geotechnical properties of lateritic soil treated with low percent bentonite (up to 10% by dry weight of soil). The evaluation included some index parameters with very wide universal acceptance such as particle size distribution, Atterberg limits, compaction characteristics together with some engineering properties related to the plasticity characteristics namely swelling and shrinkage behaviour as well as hydraulic conductivity. Soil mixtures for the engineering properties tests were compacted with British Standard Light (BSL) compactive effort at predetermined optimum moisture content. From the results, it was observed that bentonite treatment generally caused an increase in plasticity of the soil. While soil mixtures containing 0 – 5% bentonite classifies as inorganic clay soils of intermediate plasticity (CI), mixtures with 7.5 – 10 bentonite are classified as CH soils in accordance with Unified Soil Classification System. Correlation between bentonite content and the measured engineering properties of the resulting soil mixtures revealed an increase in optimum moisture content, free swell as well as desiccation induced shrinkage strain but a reduction in dry unit weight and hydraulic conductivity of specimens with higher bentonite content. Keywords : Bentonite, desiccation shrinkage, hydraulic conductivity, lateritic soil, plasticity characteristics,
TL;DR: In this article, the authors examined the non-parametric analysis of production efficiency of poultry eggs farmers in Delta State Nigeria using structured questionnaires administered to 120 randomly selected poultry farmers in four Local Government Areas of the State.
Abstract: This study examined the non-parametric analysis of production efficiency of poultry eggs farmers in the Delta State Nigeria. Data used for the study were obtained using structured questionnaires administered to 120 randomly selected poultry farmers in four Local Government Areas of the State. Data envelopment analysis and Cobb- Douglas production function were used to analyze the data. Results showed that 30% of the poultry farmers in the study area were operating at frontier and optimum level of production with mean technical efficiency of 1.00. This implies that 70% of the poultry farmers in the study area can still improve on their level of efficiency through better utilization of available resources, given the current state of technology. The results of the Cobb-Douglas analysis of factors affecting the output of poultry farmers showed that stock capacity (number of birds), feed and medication cost positively and significantly affected the output of the poultry egg farmers in the study area. This indicated that a unit increase in these inputs led to increase in the gross output of poultry egg farmers in the study area by 49.12%, 46.99% and 20.74% respectively. The study further showed that most of the poultry farms could reduce total expenditures on the number of birds purchased, feed, labour, medication and capital inputs by 20.43%, 3.20%, 3.53%, 7.10%, and 31.80% respectively without reducing their current level of production. It is recommended that poultry egg farmers in the study area should form cooperative societies so as to enable them have access to productive inputs that will enable them expand. It is further recommended that enhanced research, extension delivery and farm advisory services should be put in place for farmers to learn the best farm practices carried out on the robustly efficient farms. This will go a long way to increase the efficiency level of the poultry farmers in the study area. Keywords: DEA, efficiency and poultry production Nigerian Journal of Technological Research , 8(2), 2013
TL;DR: In this article, a semi-detailed soil survey of the floodplains of lower Oshin River in Kwara State, Nigeria was carried out using rigid-grid survey method.
Abstract: A semi-detailed soil survey of the floodplains of lower Oshin River in Kwara State, Nigeria was carried out using rigid-grid survey method. Three soil units designated as OSH-1, OSH-2 and OSH-3 were identified on the basis of drainage, topography, soil texture and depth. The soil texture ranges from sandy clay loam in OSH-1 to sandy loam in OSH-2 and OSH-3 for the topsoil overlaying clay loam or sandy loam subsoil. The soil pH (H2O) was moderately to slightly acid with values ranged from 5.1-5.7 in OSH-1 and 5.9-6.9 in OSH-2 and OSH-3. The available P in all soil units decreased with soil depth and the values for the topsoil were 22, 40 and 10 mg kg -1 respectively for OSH-1, OSH-2 and OSH-3 and was rated high in OSH-1 and OSH-2, and medium in OSH-3. Also, organic C content for topsoil was 27.5, 35.5 and 28.0 g kg -1 for OSH-1, OSH-2 and OSH-3 and its distribution within the profiles was irregular except in OSH-1 where it decreased regularly with soil depth. The CEC value for the topsoil was between 19.14 and 21.99 cmol(+) kg -1 and all rated high. The soil units were classified as Typic Endoaquepts/ Fluvic Cambisols (Clayic), Aquic Ustifluvents/ Gleyic Fluvisols (Arenic) and Oxyaquic Ustifluvents/ Gleyic Fluvisols (Eutric) using USDA Soil Taxonomy and WRB systems respectively. With exception of drainage problems which can be overcome by provision of adequate drainage infrastructure, the soils of the lower River Oshin floodplain have great potential for rain-fed agriculture. Nigerian Journal of Technological Research
TL;DR: In this paper, the state of physical facilities in Nigerian tertiary institutions in comparison with cost of facilities management in the institutions was examined by determining the availability of physical facility in the institution, assessment of the various facilities managers in an institution, and determining if the cost expended on facilities management, reflects the current state of the physical structures.
Abstract: This paper examined the state of physical facilities in Nigerian tertiary institutions in comparison with cost of facilities management in the institutions. This was achieved by determining the availability of physical facilities in the institution, assessment of the various facilities managers in the institution, and determining if the cost expended on facilities management in the institution, reflects the current state of the physical structures. The data collected were analyzed using mean method and simple regression analysis. The result of the analysis revealed that availability of physical facilities in the institution had a mean value of 2.226, performance of the various facilities managers in the institution had a mean value of 2.760, and the simple regression analysis showed that cost expended on facilities management in the institution, reflects the current state of the physical structures with R 2 value of 87%. The findings show that, the physical facilities in the universities were inadequate, cost of maintenance expended in the institution has a great impact on the state of the structures and performance of various facilities managers in the institution is just above average. Based on the findings, it was recommended that the government should provide adequate funds to the universities in its annual budgetary allocation. Besides, adequate provision of facilities should be provided while students should be well-educated on how to maintain available facilities in Nigerian universities. Keywords: Facility management, Physical facilities, University structures Nigerian Journal of Technological Research
TL;DR: In this paper, the dynamic effect of re-vibration on the compressive strength of concrete using concrete mix aggregate of 1:2:4 from Ordinary Portland cement with water to cement ratio of 0.75 is presented.
Abstract: The dynamic effect of re-vibration on the compressive strength of concrete using concrete mix aggregate of 1:2:4 from Ordinary Portland cement with water to cement ratio of 0.75 is presented. Concrete cubes which were cast with re-vibration time lag intervals of 5minutes successions for 60minutes period of revibration process at 7, 21 and 28 days of curing were crushed for their respective compressive strength. Result shows that at successive time lag intervals there is an appreciable dynamic rise in compressive strength of concrete with such water to cement ratio. The result obtained suggests the use of 5minutes time lag interval of revibration process to depict the dynamic rise of compressive strength of concrete. Keywords : Compressive strength, dynamic, re-vibration, time-lag intervals, water, cement, ratio.
TL;DR: In this article, the authors analyzed a 12-year maintenance data classified under machine time, downtime, idle time, running time, among others, and found that the long run maintenance practice of the organization has caused between 87-94% of the machines/equipment to be in idle state while between 6-13% to be due for retirement.
Abstract: There are several reasons why maintenance managers need to ascertain, from time to time, the reliability profile of their production machines that are subject to constant use. This study furnishes the justifications by analyzing a 12-year maintenance data classified under machine time, downtime, idle time, running time, among others. Markov chain model as well as some reliability models – availability, mean time to failure, mean time between failures, hazard rate (λ) – were used to analyze the bulky data obtained from a soft drink bottling company based in Lagos, Nigeria. Our results suggest that the long run maintenance practice of the organization has caused between 87-94% of the machines/equipment to be in idle state while between 6-13% to be due for retirement. It is our candid opinion that if urgent action is not taken to whittle down the lingering trend the company will get to the brink of collapse. Keywords: Transition matrix, Absorbing state, Catastrophic Failure, Matrix Utilization Factors Nigerian Journal of Technological Research
TL;DR: In this paper, a study was designed to assess teaching and learning styles in practical motor vehicle mechanics work at technical college level in Niger State, where a total of 403 respondents comprising 375 students and 28 teachers were used as population of the study.
Abstract: This study was designed to assess teaching and learning styles in practical motor vehicle mechanics work at technical college level in Niger State. Two research questions were formulated to guide the conduct of the study. A descriptive survey research design was employed for the study. The study was carried out in all the Technical Colleges in Niger State. A total of 403 respondents comprising 375 students and 28 teachers were used as population of the study. A structured questionnaire was developed by the researcher and used for data collection. The instrument was face and content validated by three Lecturers. Mean statistical tool was used to analyze the data for answering research questions. The findings of the study revealed among others that teachers adopt High Teacher Centered (HTC) styles in teaching practical skills; and that students preferred High Learner Centered (HLC) and Intermediate Learner Centered (ILC) styles in acquiring practical skills. Based on the findings it was recommended among others that Niger State Science and Technical Schools Board should organize workshop for its teachers in technical colleges on the effective use of student centered styles of teaching and teachers should always allow the students to participate actively in any activities when teaching practical skills.
TL;DR: In this article, the authors describe ways by which soil biology can be harnessed more efficiently in agriculture through use of soil-specific inoculants, legume-based cropping systems, and incorporation of locally derived materials that would not otherwise be directed to livestock.
Abstract: In developed countries, continuous monocropping, high-disturbance tillage, and ready access to synthetic inputs have allowed farmers and researchers to obtain high crop yields with little regard for soil biology. An unrecognized “opportunity cost” associated with large-scale agriculture is the depletion of soil biological complexity, which may taken many years to restore. The opportunity costs of biologically depleted soils, however, have not been incurred in much of the developing world because synthetic inputs have been much less accessible to the small landholder. Indeed, the developing world can ill afford to overlook the potential benefits of plant-microbe and microbe-microbe interactions which occur in soils when available nutrients are low. How then can farmers and researchers best take advantage of indigenous soil biological interactions which can enhance nutrient availability in agricultural systems? This overview describes ways by which soil biology can be “harnessed” more efficiently in agriculture through use of soil-specific inoculants, legume-based cropping systems, and incorporation of locally derived materials that would not otherwise be directed to livestock. Keywords: soil microorganisms, plant nutrients, rhizobacteria, mycorrhizae, soil disturbance, plant-microbe interactions Nigerian Journal of Technological Research
TL;DR: In this article, the effects of population density on the dynamics of tuberculosis were discussed using deterministic modeling approach and the analysis showed that there exists a globally stable disease-free equilibrium point.
Abstract: In this study, the effects of population density on the dynamics of tuberculosis were discussed using deterministic modeling approach . A mathematical model was formulated that incorporated the size of the area occupied by the population being studied. The results suggested that the observed trend in tuberculosis incidence was partly as a result of explosive population growth due to urbanization and resettlements. In the qualitative analysis of the model, the disease free steady state was analyzed for stability using Rowth Hurwitz theorem. The analysis showed that there exists a globally stable disease-free equilibrium point. The disease-free equilibrium point will be globally asymptotically stable provided the characteristic area per individual is greater than the product of the probability of survival from latent stage into the infectious stage and the number of latent infections produced by a typical infectious individual during the mean infectious period. The results of numerical simulation were remarkably in line with those of the qualitative analysis of the model. Key words : Tuberculosis, Population density, Equilibrium State and Stability Analysis.
TL;DR: This work has proposed model for measuring OO software testing effort by taking different affecting factors into consideration, and it is proposed that the testing effort is the activity which is least bother by researchers.
Abstract: Estimation and measurement is an important field of software engineering. There are several factors available in real word that can be measured directly, but few or no software engineering attributes or tasks are so simple that can measure directly. Due to development of OO paradigm it is also become cumbersome to measure different attributes of software development directly. All attributes and activities are depending on several other attributes or factors. To measure these activities we have to take consideration of different types of metrics. In context of OO software, measuring the testing effort is the activity which is least bother by researchers. In this work we have proposed model for measuring OO software testing effort by taking different affecting factors into consideration. Keywords: OO Software Testing, measurement, metrics, effort Nigerian Journal of Technological Research , vol 7(1) 2012
TL;DR: In this article, a study was conducted in Delta State, a major Niger Delta region of Nigeria, to evaluate some heavy metals concentration in municipal wastes dumpsites that are presently used for intensive horticultural crops production.
Abstract: A study was conducted in Delta State, a major Niger Delta region of Nigeria. The aim was to evaluate some heavy metals concentration in municipal wastes dumpsites that are presently used for intensive horticultural crops production. The heavy metals studied were; Iron (Fe); Lead (Pb); Mercury (Hg); Cromium (Cr); Nickel (Ni); and Cadmium (Cd). A semi- detailed survey at the scale of 1:25,000 was employed in the study, and five permanent dumpsites randomly located in Warri, Ughelli, Sapele, Agbor and Asaba were used. A total number of 30 composite waste samples were collected, processed and digested using Diethylenetriaminepenta-acetic acid (DTPA) extracting solution. The results of the study showed that the values of the heavy metals evaluated ranged from 83.92-- 100.03.mgkg-1 for (Fe); 0.02--0.07 mgkg-1 for (Pb); 1.41--7.71 mgkg-1, for (Cr), 0.08-1.06 mgkg-1 for (Cd), 0.20- 13.19 mgkg-1 for (Ni), and 0.01-- 13.65 mgkg-1 for (Pb), respectively. Apart from lead (Pb), in which the mean concentration value was greater than the FAO-WHO permissible standard of 1.5 mgkg-1 in Warri, Ughelli, Sapele and Agbor dumpsites, the values obtained for other heavy metals were within the maximum tolerable levels. However, there is need to be cautious since crops grown on soils amended with urban wastes can immobilize heavy metals which could find their ways into human being through food chain processes. Hence, the reason for regular monitoring of the quality and concentration of heavy metals in waste dumpsites used for horticultural purposes because of health reasons. Keywords : Evaluation, heavy metals urban waste dumpsites.
TL;DR: The study showed that students are ready for e-learning, and have the right learning attitude as discussed by the authors The study also revealed that about half of the students have laptop as one of the personal technologies for e learning Significant relationship exists between e- learning readiness and prior exposure to e learning by undergraduate students No significant difference exists between Students' lifestyle attitude to learning whether they have any prior e learning experience or not.
Abstract: This study investigated the Nigerian undergraduate students’ readiness for e-learning Two hypotheses were evolved to give direction to this study The study was a pilot study and the University of Lagos was purposively selected It was targeted at undergraduate students of the University of Lagos A simple random sampling method was used in selecting the faculties and in administering the questionnaire Respondents were drawn from the Faculties of Science, Engineering, Education, Law and Business Administration Items in the questionnaire included closed and open-ended questions that sought information on students’ study habits, possession of personal technologies, location where they have internet access on campus, lifestyle attitude towards learning, any e-learning experience and if they ever attended any seminar or workshop on e-learning The use of questionnaire was complemented with observation method to see how the students faired on their use of Information and Communication Technologies (ICT) mainly at the University Library Data collected were subjected to statistical analysis using descriptive statistics and significance was tested using student t-test with alpha set at 005 significant levels The study showed that students are ready for e- learning, and have the right learning attitude The study also revealed that about half of the students have laptop as one of the personal technologies for e learning Significant relationship exists between e- learning readiness and prior exposure to e learning by undergraduate students No significant difference exists between Students’ lifestyle attitude to learning whether they have any prior e- learning experience or not Based on this finding, a case was made for active collaboration locally and internationally to develop and implement e- learning initiatives in Nigerian higher institutions for both regular and distance learning students Keywords: E- learning, readiness assessment, ICT Nigerian Journal of Technological Research
TL;DR: Corroded water pipes and soil samples were analysed for microbiological and physicochemical properties between the months of February and July, 2008 and there were significant differences between the mean total aerobic bacterial counts, anaerobic bacterial counts and fungal counts in the various locations.
Abstract: Micro organisms associated with corrosion of water pipelines in Barkin-Sale, Bosso, Chanchaga, Keteren-Gwari, Maikunkele and Kwangila areas of Minna metropolis in Niger State of Nigeria were isolated. Corroded water pipes and soil samples were analysed for microbiological and physicochemical properties between the months of February and July, 2008. Bacteria isolated were Desulfovibrio desulfuricans, Desulfotomaculum nigrificans, Thiobacillus thiooxidans, Lactobacillus lactis, Clostridium perfringens, Pseudomonas aeruginosa, and Bacillus cereus var mycoides, B. subtilis, B. cereus and Staphylococcus aureus while fungi isolated were Aspergillus niger, A. fumigatus, Penicillium notatum, Candida tropicalis, Mucor mucedo, Torulopsis candida, Geotrichum candidum and Fusarium solani The bacterium most frequently isolated was D. desulfuricans (56.67%) while the fungus with the highest occurrence was A. niger (25.00%). The mean total aerobic bacterial counts ranged from 3.50x103cfu/g to 7.16x104cfu/g, mean total anaerobic bacterial counts ranged from 5.59x104cfu/g to 7.69x106cfu/g and the mean total fungal count ranged from 3.0x103 cfu/g to 5.63x105cfu/g. From the data, there were significant differences (p<0.05) between the mean total aerobic bacterial counts, anaerobic bacterial counts and fungal counts in the various locations. Key Words: Microorganisms, water pipes, corrosion, soil samples, microbiological and physicochemical properties
TL;DR: The home power management system developed under test produced outputs which exhibited good correlation with the input supply and good implementation of the timing algorithm for all programmed outputs.
Abstract: This study aimed at the design and development of a prototype Power Management System for home which will enhance energy user behavior for achieving energy consumption efficiency. It allows the user to transfer management of supply to appliances at home to a real time monitoring, switching and control device with four regulated and one unregulated supply outlets. The PIC16F887 Microcontroller was programmed to provide 24 hour real-time timing power consumption management according to user-supplied timing parameters made available to the programmed Code with the help of the PCF8583 real time clock. The home power management system developed under test produced outputs which exhibited good correlation with the input supply. Whereas the input to the device was 186V, the output for ports 1, 2, 3, 4 and 5 were respectively 187V, 185V, 184V, 185V and 183V which is a satisfactory input-output correlation. The unit also exhibited good implementation of the timing algorithm for all programmed outputs. It switched "ON" and "OFF" at the set times for the regulated ports showing that power was managed as desired in accordance with the inputted timing parameters. The user only has to set the timing parameters once and thereafter the device maintains these settings until such a time as the user decide to change them. Also the user does not have to surrender the decision on when power is switched ON to the device to make by making predictions based on whatever criteria. This ensures that the user retains certain level of control over the device in terms choice of when appliances should be powered. This flexibility in an automation system is one strong point of this device. Keywords: Real-time, Power Consumption Management, Timing algorithm Nigerian Journal of Technological Research , 8(2), 2013
TL;DR: In this paper, the suitability of groundnut shell ash (GSA) mixed with 45% slaked lime was investigated for the 28-day minimum strength of 20N/mm2.
Abstract: The suitability of groundnut shell ash (GSA) mixed with 45% slaked lime was investigated. The aim was to determine the percentage GSA/lime and water-cement ratio that would give the 28 – day minimum strength of 20N/mm2. Groundnut shells were burnt and the ash sieved using 150 micrometer sieve. The ash mixed with 45% slaked lime was used to partially replace ordinary Portland cement (OPC) in various proportions. The design mix used was 1:2:4 and water – cement ratios of 0.45, 0.55 and 0.65 by weight. Nine cubes of side 150mm were cast for each proportion and water – cement ratio. The cubes were cured by complete immersion in water at room temperature. Three cubes were tested for density and strength at each of the ages of 7, 14 and 28 days for each proportion of OPC/GSA – lime. It was concluded that for a mix of 1:2:4, the proportion of GSA/lime up to 20% gave the 28-day minimum strength of 20N/mm2 at water-cement ratio of 0.65 and was recommended for use as structural concrete. Keywords : Groundnut shell ash, Cement, Concrete, Water-cement ratio, Strength Nigerian Journal of Technological Research , vol 7(1) 2012
TL;DR: In this paper, active carbon was used to purify effluents from a Bottling Company using NaCl, KOH, H2SO4 and H3PO4 as activating agents.
Abstract: Activated carbons were prepared from Palm kernel shells. Carbonization temperature was 6000C, at a residence time of 5 min for each process. Chemical activation was done by heating a mixture of carbonized material and the activating agents at a temperature of 70 0 C to form a paste, followed by subsequent cooling and using the active carbon to purify effluents from a Bottling Company. NaCl, KOH, H2SO4 and H3PO4 were used as the activating agents at 1M and 2M and 710 μm particle size. The activated carbon samples produced were found to posses properties within the limits of commercial activated carbons. Bottlimg company effluent was purified and the results showed that carbonized materials activated with 2M H2SO4 had the best adsorption characteristics. These properties include 1.12% moisture content, 2.50 % ash content, 57.00 % yield of activated carbon, 93.65 % fixed carbon, 2.73 % volatile content, 0.97 g/cm3 bulk density and 0.69 cm3 pore volume. Keywords: Active carbon, Palm kernel shell, Effluent, Purification Nigerian Journal of Technological Research
TL;DR: In this paper, the impact of long term application of palm oil waste on physical and chemical properties of a sandy Ultisols (Arenic Kandiustult) in Uga, Nigeria was investigated.
Abstract: The study investigated the impact of long term application of palm oil waste on physical and chemical properties of a sandy Ultisols (Arenic Kandiustult) in Uga, Nigeria. Soil samples were collected from the surface (0-10cm) and (15-25cm) of palm oil polluted site. Another surface sample of (0-10) and (15-25) samples were collected 15 meters away in the palm oil unpolluted (control site). Core samples were collected from both soils. All the samples were analyzed for selected physical and chemical properties. The results showed that both soils were loamy sand but varied in the other physical properties as bulk density and total porosity. The two soils were strongly acidic, but had more carbon, nitrogen and phosphorus in the palm oil polluted soils than in the unpolluted soils. The results indicated that the area affected with the palm oil mill effluent (POME) had more nutrient status but reduced plant growth due to clogging of water and restricted aeration. The statistical package used to analyze this work is descriptive statistics and paired sample T-test. Knowledge of the component and proper disposition of these pollutants should be made known to the people of Uga. Keywords: Keywords: Degradation; Palm oil mill effluent; Environmental hazards Nigerian Journal of Technological Research