617 research outputs found

    Effects of Drying Temperature on The Effective Coefficient of Moisture Diffusivity and Activation Energy in Ibadan-Local Tomato Variety (lycopersicum esculentum)

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    A study of the mechanism of mass transfer phenomena of Ibadan-local variety was carried out. Ibadan-Local tomato varieties pre-treated in a binary (sugar and salt) osmotic solution of concentration (45/15oBrix), solution temperature (30, 40, 50oC), was studied by developing a mathematical model to describe the Water Loss (WL) and Solid Gains (SG). Drying was monitored at three temperatures (40, 45 and 50oC) until   equilibrium weight was achieved using the oven-dry method. Five thin layer drying models (Exponential, Henderson & Pabis, Page, Modified Page and Logarithmic) were compared and fitted into the experimental values of the non-linear moisture ratio; MR. The diffusion coefficient and activation energy were determined using the Arrhenius equation. Drying occurred in the falling rate phase and different models fit at different temperatures. Calculated values of effective moisture diffusivity varied from 1.17-3.51x10-8 to 1.25-3.13x10-8 and activation energy varied from a maximum of 52.61KJ/mol in treated to 46.81 KJ/mol in untreated tomato. At all temperatures, effective coefficient of moisture diffusivity and activation energy values was higher in osmosized tomato Keywords: Osmotic dehydration, Water loss, Solid gain, Effective moisture diffusivity and Activation energy

    Influence of Varietal Difference on Qualities of Osmosized Tomato in the South Western Nigeria

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    Mechanism of mass transfer phenomena of three major varieties available in the South-western Nigeria market are Roma-VF Koledowo and Ibadan-Local variety. Tomato varieties pre-treated in a binary (sugar and salt) osmotic solution of three solution concentration; three temperature; five osmotic time and fruit to solution ratio 1:10 was studied by developing a conceptual model to describe the Water Loss and Solid Gains. Initial moisture content was determined using the AOAC standards. Statistical analyses of the data within and across varieties were carried out. This study therefore investigated the effect of varietal difference on the qualities of osmosized tomato i.e. the highest water loss and least solid gain. Effect of pretreatment varies with variety with a mean water loss range value of 0.2615-0.3031. Water-loss and Solid gain were significant (p?0.05) for all variables considered. Koledowo with the thickest skin had the least owing to its ability to allow moisture migration Keywords: Water loss, Solid gain, Osmotic time, Varietal difference, Pretreatmen

    Comparative Study of Multiple Regression Model with Curvefit Model for The Prediction of Solar Radiation in Mubi Town Adamawa State, Nigeria

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    The sun emits solar radiation, which is critical for researchers working on renewable energy technology that provides ecologically favorable power systems. This research created a new model to forecast DHSR for the Mubi metropolitan area in Adamawa State, Nigeria. Data for this study were obtained from the National Aeronautics and Space Administration (NASA) over a 22-year period (2000 – 2021). When DHSR was employed as an output, the requested values were air temperature (Tai) and relative humidity (Rhi). The MATHLAB curve fitting program was used to create the new DHSR mathematical model. The model was validated using five statistical methods in this study: MSE (mean square error); SSE (sum of square errors); RMSE, Chi-square error (X2), and the absolute fraction of variance (R2) are 0.0005, 0.0064, 0.0231, 0.0011kWh/m2/day, and 0.9998, respectively

    STRATEGIC MODULATION OF THERMAL TO ELECTRICAL ENERGY RATIO PRODUCED FROM PV/T MODULE

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    Several strategies have been developed to enhance the performance of a solar photovoltaicthermal (PV/T) system in buildings. However, these systems are limited by the cost, complex structure and power consumed by the pump. This paper proposes an optimisation method conversion strategy that modulates the ratio of thermal to electrical energy from the photovoltaic (PV) cell, to increase the PV/T system’s performance. The design and modelling of a PV cell was developed in MATLAB/Simulink to validate the heat transfer occurring in the PV cell model, which converts the radiation (solar) into heat and electricity. A linear regression equation curve was used to define the ratio of thermal to electrical energy technique, and the behavioural patterns of various types of power (thermal and electrical) as a function of extrinsic cell resistance (Rse). The simulation results show an effective balance of the thermal and electrical power when adjusting the Rse. The strategy to modulate the ratio of thermal to electrical energy from the PV cell may optimise the PV/T system’s performance. A change of Rse might be an effective method of controlling the amount of thermal and electrical energy from the PV cell to support the PV/T system temporally, based on the energy need. The optimisation technique of the PV/T system using the PV cell is particularly useful for households since they require electricity, heating, and cooling. Applying this technique demonstrates the ability of the PV/T system to balance the energy ( thermal and electrical) produced based on the weather conditions and the user’s energy demands

    A multi-site assessment of knowledge of Ebola virus disease among health workers in south-west Nigeria

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    Objective: Nigeria may have been certified free from Ebola Virus Disease (EVD) by the World Health Organization, but not without its aftermath on many, especially among health workers who came in contact with the infected during the West African outbreak in 2014.This study was conducted among health workers in three tertiary hospitals in South-West Nigeria. It aimed at assessing their knowledge of EVD in a bid to forestall future contagion from patients.Method: 600 consenting participants selected through two-stage sampling method were involved in the study. Primary data was retrieved through self-administered questionnaire.Results: Majority (84.0%) of the participants knew that EVD can be contacted through blood and bodily fluid of an infected person, (78.0%) knew that EVD can be prevented by avoiding contact with an infected person, while (76.0%) identified bleeding from orifices as one of the signs of EVD. However, (6.0%) of the participants did not know how EVD can be prevented.Conclusion: Result showed that participants have average knowledge of EVD and therefore, are not adequately informed of EVD. The study recommended wider dissemination of adequate information on EVD among health workers in tertiary hospitals to forestall future contagion of the infection from patients.Keywords: Knowledge, EVD, Contagion, Outbreak, Prevention, Bleedin

    Feasibility of Large-Scale Combined-Cycle Hydroelectric Power Generation at Shiroro Hydroelectric Power Station, Nigeria

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    This paper focuses on a model for increasing the power generation of a hydroelectric power station using the combined application of hydrokinetic turbines installed at the tailrace of the existing dam. Hydrokinetic turbines will capture additional power from the energy remaining in water currents exiting draft-tube outlets and tailrace of the dam. Two commercially available hydrokinetic turbines of different orientation were used for the analysis to theoretically estimate the increased power generation capability of Shiroro hydropower station using an array of 75, 150, 225 and 300 units. Preliminary results showed that at 50% reliability, combined-cycle hydropower can increase the generation capacity of Shiroro hydropower station by 2.5% and that there is a considerable power generation potentials that can be harnessed to augment existing output from the power station and alleviate the existing power problems in the country

    Les corps étrangers en ORL: expérience de dix ans

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    Les corps étrangers (CE) représentent une pathologie fréquemment rencontrée en pratique ORL d'urgence. Ils peuvent constituer une urgence vitale par leur aspect ou leur siège. Nous présentons le bilan de dix ans sur la prise en charge des CE de la sphère ORL avec une revue de la  littérature. Il s'agit d'une étude rétrospective entre Janvier 2004 et Décembre 2013, incluant tous les cas de CE des voies aéro-digestives supérieures et auriculaires colligés dans le service d'ORL au CHU Mohammed VI de Marrakech au Maroc. Sur les 1317 cas de CE de la sphère ORL colligés durant cette période, 80,48% concernaient les enfants. Le sex-ratio était de 1,5. L'âge moyen était de 12,92 ans. Les CE oesophagiens étaient les plus fréquents (47,53%). Les complications ont été rencontrées dans 11,69% des cas. Les CE dans la sphère ORL restent fréquents en pratique quotidienne surtout chez les enfants. Leur prise en charge nécessite une intervention rapide avec un matériel adapté et des médecins entrainés. La prévention reste la meilleure solution

    Safe meat-handling knowledge, attitudes and practices of private and government meat processing plants? workers: implications for future policy

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    Introduction. Food-borne disease outbreaks remain a major global health challenge and cross-contamination from raw meat due to poor handling is a major cause in developing countries. Adequate knowledge of meat handlers is important in limiting these outbreaks. This study evaluated and compared the safe meat-handling knowledge, attitudes and practices (KAP) of private (PMPP) and government meat processing plants? (GMPP) workers in south-western Nigeria. Methods. This cross sectional study comprised 190 meat handlers (PMPP = 55; GMPP = 135). Data concerning their safe meat-handling knowledge, attitudes and practices as well as their socio-demographic characteristics, such as age, gender and work experience were collected. Results. A significant association was observed between the type of meat processing plants and their knowledge (p = 0.000), attitudes (p = 0.000) and practices (p = 0.000) of safe meat-handling. Meat handlers in the GMPP were respectively, about 17 times (OR = 0.060, 95%CI: 0.018-0.203), 57 times (OR = 0.019, 95% CI: 0.007-0.054) and 111 times (OR = 0.009, 95%CI: 0.001- 0.067) less likely to obtain good knowledge, attitude and practice level of safe meat-handling than those from PMPP. Further, KAP levels were significantly associated with age group, education and work experience (p inf. 0.05). Discussion. Study findings suggest the need for future policy in food industry in developing countries to accommodate increased involvement of private sector for improved food safety and quality delivery. Public health education on safe food handling and hygiene should be on the front burner among food handlers in general

    Effect of Two Cowpea (Vigna unguiculata) Fodder Cultivars as Supplements on Voluntary Intake; Milk Yield and Manure Production of Bunaji Cows

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    The feeding value of fodder from two cowpea cultivars to a basal maize stover diet was investigated using fifteen lactating White Fulani (Zebu) cows. The two cultivars were IT-716 and 994-DP. Diet was constituted as 50g DM/kg live weight and each of the cultivars was supplemented at 50% of the daily dry matter requirement of individual animals. The experimental design was a complete randomize. The parameters measured included feed intake, milk yield and composition and manure production. In a separate trial, dry matter degradation of the fodder was assessed. There were no significant differences in dry matter intake of the supplements. However, the dry matter intake of stover in the control diet was higher than those on the supplemented groups. The milk yields ranged from 887 to 1378 ml/day. Milk yield differed among treatments. Supplementation did not affect (P 0.05) fat, protein, total solids and ash contents of the milk across the treatments. Manure productions were not significantly different among the treatments. Similarly, content of N, P and K in manure were comparable among the treatments except for N that was lower (P 0.05) in the control group. The dry matter degradation was influenced by the fodder cultivars. The feeding of dual-purpose forage legumes residues could enhance milk production in lactating Zebu cows. This may be further increased by exploring other ways of improving feed residue utilization in the dry season

    An integrated low carbon energy solution to cooking fuel, tailored to Niger state’s rural population

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    Niger State (Nigeria) was selected as a case study of renewable, affordable and user friendly clean energy provision in remote areas of developing countries. Niger state has 80% of its 4.5 million population living in rural agrarian areas with low literacy rates, there is a lack of wind thus eliminating wind as widely available potential power source. Based on the assessment of the local large insolation, the type of agricultural, biomass and husbandry resources, this study selected the design of anaerobic digestion units processing mostly animal and human waste, and whose heating and power requirement would be entirely provided by solar photovoltaic/thermal to maintain optimum efficiency of the biogas production. The designs was carried out at the scale of up to 15 household demand (community scale). Volume and therefore the production of biogas maybe increased or decreased in the design considered, and local, low cost resilient material were proposed. The proposed system was costed for a community of 24 people, demonstrating the potential for clean and renewable gas production economically
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