86 research outputs found

    Impact of teacher’s personality on academic performance of biology students in Ogba-Egbema-Ndoni Local Government Area, Rivers State

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    Recent results of Senior Secondary Schools (SSS) Biology shows a decline in achievement, even those who take the exams, scale through with mere passing grades with no distinction. This study is therefore an attempt to investigate learner's achievement in Biology with respect to teacher factors. The characteristics of the biology teacher (BT) under examination are subject mastery, skill set, attitude to work and degree of job satisfaction. The instrument for data collection was a structured questionnaire administered to 312 respondents, consisting of 300 SSS students studying Biology and 12 BTs. The respondents were randomly selected from six (6) schools in Ogba-Egbema-Ndoni Local Government Area (ONELGA), Rivers State. Data was analyzed by descriptive statistics and a mean score of 2.50 was considered significant for the TF under consideration. Results indicate grand mean scores as follows: relationship between BTs’ subject mastery and learners’ performance (3.87>2.25), relationship between BTs' skill set and learners' performance (2.95>2.5); relationship between the biology teachers' attitude to work and learners' performance (2.87>2.5), relationship between BTs' job satisfaction and learners' academic performance (2.53>2.50). The results show that teacher personality factors such as subject mastery, skill set and attitude to work influence the performance of Biology students in Senior Secondary Schools in ONELGA, Rivers State

    PRODUCT DIFFERENTIATION: A TOOL OF COMPETITIVE ADVANTAGE AND OPTIMAL ORGANIZATIONAL PERFORMANCE (A STUDY OF UNILEVER NIGERIA PLC)

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    In recent years the concept of competitive advantage has taken centre stage in discussions of business strategy; that is why, one of the major challenges organizations face today is how to have a competitive advantage. In most cases a stand out product will do the job, since products are perceived as both highly relevant and meaningfully, the ability for any one product to standout in a competitive category will guarantee the success of such organization. While there are numerous ways to differentiate brands, identifying meaningful product-driven differentiators can be especially fruitful in gaining and sustaining a competitive advantage. Differentiation is when a firm or brand outperforms rival brands in the provision of a feature(s) such that it faces reduced sensitivity for other features (Sharp & Dawes, 2001). Even in industrial economics, a discipline where there is more of a tradition of providing formal statements of theoretical concepts, two eminent industrial economists felt obligated to write an article for the Journal of Industrial Economics titled "What is Product Differentiation, Really?" (Caves and Williamson, 1985)

    Investigation of Wear Land and Rate of Locally Made HSS Cutting Tool

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    Production technology and machining are inseparable with cutting operation playing important roles. Investigation of wear land and rate of cutting tool developed locally (C=0.56%) with an HSS cutting tool (C=0.65%) as a control was carried out. Wear rate test was carried out using Rotopol –V and Impact tester. The samples (12) of locally made cutting tools and one (1) sample of a control HSS cutting tool were weighed to get the initial weight and grit was fixed at a point for the sample to revolve at a specific time of 10 mins interval. Approach of macro transfer particles that involved mechanism of abrasion and adhesion which was termed as mechanical wear to handle abrasion adhesion processes was used in developing equation for growth wear at flank. It was observed from the wear test that best minimum wear rate of 1.09 x10-8 and 2.053x10-8 for the tools developed and control were measured. MATLAB was used to simulate the wear land and rate under different conditions. Validated results of both the experimental and modeling showed that cutting speed has effect on wear rate while cutting time has predicted measure on wear land. Both experimental and modeling result showed best performances of tools developed over the control

    Microstructural Characterization and Some Mechanical Behaviour of Low Manganese Austempered Ferritic Ductile Iron

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    This work studied the microstructural characterization and mechanical behavior of low manganese Austempered Ductile Iron (ADI), with a view to improve the properties of iron and to increase the areas of applications. Three sets of ductile iron of specified composition were machined from Y-blocks to tensile and hardness pieces. The samples were preheated at 350 0C for 1hr and austenitised at 900 0C for 1hr in salt bath furnace. The three sets of samples were immediately austempered in the austempering salt bath furnace at uniform austempering temperatures of 300 0C, 350 0C and 400 0C for 90, 120 and 150 minutes; each sample for each temperature window. All sets were prepared for metallographic examination; tensile and hardness tests were carried out. The results showed that maximum hardness, tensile and yield strength were obtained at austempering temperature of 350 0C and at 150 minutes. At 300 0C and 350 0C, it was noticed that the hardness and strength increase with austempering time. The optimum tensile strength was 1300 MPa at 350 0C after austempering for 150 minutes. In conclusion the austempering operation has a significant effect on the mechanical and microstructural properties of ADI

    COMPOSITE MATERIALS FOR ECO-FRIENDLY FIRE RETARDANT BUILDING CEILINGS FOR TROPICAL REGION

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    The emission of noxious elements from building ceiling fire is increasingly becoming a source of concern globally. Hence, there is the need to develop eco-friendly flame-retardant building ceilings from composite materials to forestall the unwanted toxic emissions. This study aims at developing a bio-degradable hybrid aluminium dross ceiling utilizing varying material percentages using the moulding process. Box-Behnken factorial design from Minitab 17 was used to analyze the effect of the variables and runs on the performance properties. The developed ceiling samples were characterized by optical microscope, scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) for structural examination. X-ray Diffraction (XRD) analysis was used for phase quantification. The calorific values and thermal properties were examined by the combustion calorimeter and automated Lee’s Disc apparatus, respectively. The mechanical properties were identified using a universal testing machine (UTM) for compressive test and E550 combustion gas analyzer for emission characterization. The results showed that aluminium dross carbon graphite developed from 0.3Aldr0.25Cmt0.3Si0.05G0.1CS exhibited the highest specific heat capacity (SHC) of about 7771.94 Jkg-1K -1 compared to eggshell and oil bean stalk ceiling composite materials. An increase of 90% was noted against the control. The thermal studies showed that there was an excellent thermal conductivity of all the developed composites in the range of 0.0075 Wm-1K - 1 -0.1458 Wm-1K -1 . 0.3Aldr0.2Cmt0.3Bt0.05G0.15OBS shows outstanding improvement with the lowest value of 0.0075Wm-1K -1 and desirable highest thermal resistivity of 133.9 m2K -1W-1 . Thermal absorptivity revealed 0.3Aldr0.25Cmt0.3Si0.05G0.1CS with value of 0.42 10-8 m2 s -1 as lowest among developed ceilings and 0.3Aldr0.2Cmt0.3Bt0.05G0.15CS has required highest thermal effusivity value of 669.2 Jm-2K -1 s -1/2. Combustion studies revealed that heat flux is not desirable in ceiling application; therefore, the least hazardous heat flux value is 0.3Aldr0.23Cmt0.3Bt0.05G0.12OBS at 12.6 W/m2 . All the developed composite ceilings and binders show non-combustible characteristics. There is an absence of volatile organic compounds (VOC) and noxious constituents from the fabricated 0.3Aldr0.2Cmt0.3Bt0.05G0.15OBS. More importantly, quasi negligible SO2 level and CO2 exist; however, 0.3Aldr0.25Cmt0.3Si0.05G0.1OBS recorded maximum CO and NO levels, an indication of toxic affluence. The low mass losses of all of the composite materials, especially for 0.3Aldr0.2Cmt0.3Si0.05G0.15UES retard significantly due to its activities by the retardant constituent. The highest crushing force of 6.6 kN and crushing strength 3.4 MN/m2 was attained for 0.3Aldr0.2Cmt0.3Bt0.05G0.15OBS developed product due to the compact arrangement of the inter-molecular hybrid formation of the composite formed. The flame retardant nature of all produced composite is evidenced in their elemental composition, as there is an absence of flammable element and presence of stable insulating compounds providing retardance to flame occurrences. These suppressions in the flame inclination of the reinforced materials are noticed within the boundaries of the ceiling crystals from the structural examination. The intermetallic phase from the diffraction intensities shows the presence of a significant second bond interstitial solid-phase across the matrix, especially for 0.6Aldr0.34Cmt0.05G0.01OBS ceiling material. This research will help in enhancing the flame retardant influence of eco-materials in building applications. The result has shown that the existing ceiling materials would be replaced with this flame-retarding ceiling material since it is more stable and fire-resistant

    Development of a Human Powered Pedal Washing MACHINE

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    Human powered pedal washing machine has been designed using materials suitable for its application. An existing bicycle was used as the pedal and other parts of the machine such as the drum, the frame was fabricated using galvanized steel. The material selection was put into consideration, such as corrosion because of the machine’s involvement with water. The human powered pedal washing machine was tested with a used dirty Laboratory coat. The pedaling washing was first done for the first 15 minutes, using water and sunlight detergent soap. There was a partial cleaning of the Laboratory coat, though the coat was very dirty. Another round of washing was done after which the first washing water was drained out through the outlet part of the machine. The second washing was excellent because the Laboratory coat was clean. The human powered pedal washing machine performed well with all the designed parts functioning well. This is an eco-friendly machine, maintenance cost free, energy conservation machine and highly sustainable for underdeveloped nations of the world

    Corrosion resistance of galvanized roofing sheets in acidic and rainwater environments

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    The galvanization of steel sheets for building roofs and construction of additional structures has been a valued solution to the challenges faced by the deterioration of roofing steel sheets in an unfavourable surroundings. This research was conducted on galvanized roofing sheets obtained from the open market in Nigeria. The samples were cut to a small size (5 cm by 4 cm) and immersed in sulfuric acid (H2SO4) and hydrochloric acid (HCl). As the control medium for the experiment, rainwater was used. The experiment was performed over 1200 hours; each sample was removed every 240 hours, thoroughly washed, dried, and weighed again. Based on the reacting media, variations in the weights of the samples were obtained. According to ASTM G1-03 standard practice, Corrosion rates were calculated for preparing, cleaning, and evaluating corrosion test specimens. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) was also carried out. Although some samples resisted corrosion, other samples corroded. It is predicted that the green-coated samples are more resistant to corrosion in rainwater and H2SO4 and thus more stable
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