474 research outputs found

    Modification of Thermal Hydraulic Transient Models for the Miniature Neutron Source Reactor

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    A modified Miniature Neutron Source Reactor (MNSR) model dealing with transient thermal hydraulic problem is presented. The model based on lumped parameter method is adopted in this work to numerically solve a system of coupled algebraic and differential equations governing heat transfer in MNSR, using MATLAB solver for variable order method in stiff differential equations and Differential-Algebraic equations, coupled with Maple soft. The simulated results obtained from the model were generally in agreement when compared with reactor operation data recorded from 0 to 270 minutes during experiments. Radiating energy of Fuel and clad and heat transferred at the gap or clearance were taken in to account. Fuel and clad temperatures as well as various temperatures at different sections of the reactor were predicted with the model, in addition to the effect of the installed chiller on the reactor coolant

    Preliminary Survey of Medicinal Plants Used in Treatment of Animal Trypanosomosis in Kaduna State, Nigeria

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    A preliminary survey of medicinal plants used in the treatment of animal trypanosomiasis in Kaduna State, Nigeria, was carried out. Three hundred questionnaires were distributed and interviews were conducted with livestock owners, livestock traders, herb sellers, herdsmen and agricultural extension workers in six local government areas namely, Birnin Gwari, Kachia, Kafanchan, Makarfi, Saminaka and Soba - Zaria. Plants commonly used included Khaya senegalensis 23.3% (70), Terminalia avicennioides 16.3% (49), Ximenia americana 12.7% (38), Anona senegalensis 10.7% (32) and Azadirachta indica 9.3% (28). The parts of the plants used included leaves, fresh bark, and roots prepared by either soaking or boiling in water. The investigation provides a baseline data for future research into these plants

    Effect of ta additions on the microstructure, damping, and shape memory behaviour of prealloyed Cu-Al-Ni shape memory alloys

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    The influence of Ta additions on the microstructure and properties of Cu-Al-Ni shapememory alloys was investigated in this paper. The addition of Ta significantly affects the green and porosity densities; the minimum percentage of porosity was observed with the modified prealloyed Cu-Al-Ni-2.0wt.% Ta. The phase transformation temperatures were shifted towards the highest values after Ta was added. Based on the damping capacity results, the alloy of Cu-Al-Ni-3.0 wt.% Ta has very high internal friction with the maximum equivalent internal friction value twice as high as that of the prealloyed Cu-Al-Ni SMA. Moreover, the prealloyed Cu-Al-Ni SMAs with the addition of 2.0wt.% Ta exhibited the highest shape recovery ratio in the first cycle (i.e., 100% recovery), and when the number of cycles is increased, this ratio tends to decrease. On the other hand, the modified alloys with 1.0 and 3.0 wt.% Ta implied a linear increment in the shape recovery ratio with increasing number of cycles. Polarization tests in NaCl solution showed that the corrosion resistance of Cu-Al-Ni-Ta SMA improved with escalating Ta concentration as shown by lower corrosion current densities, higher corrosion potential, and formation of stable passive film

    PHYTOCHEMICALS AND HYPOGLYCEMIC PROPERTIES OF METHANOL LEAF EXTRACT OF PHYLLANTHUS AMARUS

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    Plants and plant products are continuously being explored in medicine against diabetics. In the present study, phytochemical screening and hypoglycemic properties of methanol leaf extract of Phyllanthus amarus against alloxan-induced diabetic rats were conducted. A total of fifteen (15) albino rats were randomly selected into 5 groups of 3 rats per group. Groups 1-3 rats were treated with   250 and 500 mg/kg methanol extract of Phyllanthus amarus and 5 mg/kg of glibenclamide respectively, while groups 4 and 5 served as diabetic and normal controls respectively. All treatments were administered orally, once daily for fifteen days. Results revealed the presence of alkaloids, terpenoids, saponins, glycosides, flavonoids, total phenols and tannins. A significant (P<0.05) and a progressive increase in blood glucose level were observed in diabetic untreated rats throughout the experimental periods. At the end of the treatment period rat treated with 250 & 500 mg/kg, P. amarus had final glucose level of 117.00±5.43 mg/dl & 106.00±4.56 mg/kg. Rats treated with 2.5mg/kg glibenclamide had final glucose level of 117.33±5.43 while the untreated rat had final glucose level of 562.50±15.45 mg/dl. The extract of phyllanthus amarus at 250 and 500 mg/kg also cause a significant improvement in body weight gain of the rat. It is concluded that phyllanthus amarus contains some useful phytochemicals with potential hypoglycemic reputations. Thus, it may be considered as a natural source of the drug for therapeutic purposes

    Malaria in Sokoto, North Western Nigeria

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    Malaria remains a major cause of mortality among children under the age of five years; it is endemic throughout Nigeria with seasonal variation in different geographic zones of the country. Malaria prevalence studies had been undertaken in many parts of Nigeria but there is probably no dataavailable from the far North Western region. This research study was undertaken to determine the prevalence, monthly distribution of malaria in Sokoto, North Western Nigeria in order to generate baseline information. A total of 1,297 blood samples were collected by simple random sampling, from patients attending the two health centres over the twelve calendar months. Thick and thin blood films were Giemsa stained and observed for the presence of malaria parasites. A total of 354 (27.29%) werepositive for malaria parasites with the highest prevalence rate being recorded in the month of August with 72 (59.5%) positive cases and the month of March having the least infection rate of 9 (9.18%). Theinfection rate according to gender showed that males had the higher infection rate of 192 (n = 635) or 30.24% than the females who had a total 162 infection (n = 662) or 24.47%. The age group 0 - 5 years hadthe highest infection rate of 123 (43.77%) while the age group 36 - 40 years had the least infection rate of 10 (9.8%). The study has revealed the presence of malaria transmission throughout the year in Sokoto, North Western Nigeria and the infection rate can be considered as moderately high

    Phase transformation and microstructure behaviour of Cu-Al-Ni shape memory alloys incorporated with cobalt addition

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    The effect of Co addition on phase transformation temperatures and microstructures of Cu-Al-Ni SMA were investigated via differential scanning calorimetry, field emission scanning electron microscopy corresponding with energy dispersive spectroscopy and x-ray diffraction. The results revealed that the β1’ and γ1’ phases’ morphology and orientation were varied after the addition of Co along with the presence of intermetallic compounds known as γ2. This phase was indicated using the EDS and XRD is related to the intermetallic compound of Al75Co22Ni3. In addition, the phase transformation temperatures tend to increase with the addition of Co and this enhancement is mainly attributed to the variation of phase morphology and the existence of γ2 precipitates

    Analyzing the Environmental Impacts and Potential Health Challenges Resulting From Artisanal Gold Mining in Shango Area of Minna, North-Central, Nigeria

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    The environmental impact and potential health challenges resulting from artisanal mining in Shango area of Minna, North Central Nigeria was put into perspective. The methodology adopted for the research includes field work and laboratory analysis. Results of field observation reveal that mining activity resulted in physical environmental impact such as land degradation, destruction of vegetation, erosion of soils and degrading water quality. Results from the laboratory analyses show that soils are contaminated with elements such as Cu (27.7ppm), Cd (0.6 ppm), Hg (0.62 ppm) and Ag (0.35 ppm) and generally show high status when compared to published standard for upper continental crust. While, Zn (14.8ppm), Ni (7.17ppm), Mn (207ppm), Pb (0.58ppm), As (0.4ppm), Co (0.55ppm), Mo (0.16ppm), and Zr (129.8ppm) are rated low in line with the published standard; other determined elements such as Cr (37.8ppm), Fe (31.1ppm) and Au (0.2ppm) are high. These elements can easily be absorbed by plants and subsequently accumulate in their tissues. When such plants are eventually eaten by man, it may lead to different health problems such as slow growth rate, liver and kidney problem. High concentration of these elements in plant tissues may causes different problems

    Prevalence and Correlates of Common Mental Disorders among Mothers of Young Children in Kilimanjaro Region of Tanzania.

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    Although poor maternal mental health is a major public health problem, with detrimental effects on the individual, her children and society, information on its correlates in low-income countries is sparse. This study investigates the prevalence of common mental disorders (CMD) among at-risk mothers, and explores its associations with sociodemographic factors. This population-based survey of mothers of children aged 0-36 months used the 14-item Shona Symptom Questionnaire (SSQ). Mothers whose response was "yes" to 8 or more items on the scale were defined as "at risk of CMD." Of the 1,922 mothers (15-48 years), 28.8% were at risk of CMD. Risk of CMD was associated with verbal abuse, physical abuse, a partner who did not help with the care of the child, being in a polygamous relationship, a partner with low levels of education, and a partner who smoked cigarettes. Cohabiting appeared to be protective. Taken together, our results indicate the significance of the quality of relations with one's partner in shaping maternal mental health. The high proportion of mothers who are at risk of CMD emphasizes the importance of developing evidence-based mental health programmes as part of the care package aimed at improving maternal well-being in Tanzania and other similar settings

    CALMS: Modelling the long-term health and economic impact of Covid-19 using agent-based simulation

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    Data Availability Statement: All data files are available from https://doi.org/10.17633/rd.brunel.19350518 The software is available on https://gitlab.com/anabrunel/calms.Copyright: © 2022 Mintram et al. We present our agent-based CoronAvirus Lifelong Modelling and Simulation (CALMS) model that aspires to predict the lifelong impacts of Covid-19 on the health and economy of a population. CALMS considers individual characteristics as well as comorbidities in calculating the risk of infection and severe disease. We conduct two sets of experiments aiming at demonstrating the validity and capabilities of CALMS. We run simulations retrospectively and validate the model outputs against hospitalisations, ICU admissions and fatalities in a UK population for the period between March and September 2020. We then run simulations for the lifetime of the cohort applying a variety of targeted intervention strategies and compare their effectiveness against the baseline scenario where no intervention is applied. Four scenarios are simulated with targeted vaccination programmes and periodic lockdowns. Vaccinations are targeted first at individuals based on their age and second at vulnerable individuals based on their health status. Periodic lockdowns, triggered by hospitalisations, are tested with and without vaccination programme in place. Our results demonstrate that periodic lockdowns achieve reductions in hospitalisations, ICU admissions and fatalities of 6-8% compared to the baseline scenario, with an associated intervention cost of £173 million per 1,000 people and targeted vaccination programmes achieve reductions in hospitalisations, ICU admissions and fatalities of 89-90%, compared to the baseline scenario, with an associated intervention cost of £51,924 per 1,000 people. We conclude that periodic lockdowns alone are ineffective at reducing health-related outputs over the long-term and that vaccination programmes which target only the clinically vulnerable are sufficient in providing healthcare protection for the population as a whole.EU Horizon 2020 STAMINA project No. 883441 (https://cordis.europa.eu/project/id/883441)
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