Development and performance evaluation of a natural draft mixed-type solar dryer for agricultural products

Reduced moisture content enhances storage properties of agricultural products and reduces post-harvest losses. Effective drying can be achieved using solar dryers in regions with abundant solar radiation. In this study, a natural draft mixed-type solar dryer suitable for rural communities of developing countries was developed. The performance of the solar dryer was also investigated using pepper, okra and tomato. The temperature taken at different points of the drying chamber and the auxiliary collector show that the temperature within the drying chamber is higher than the ambient temperature. The temperature within the drying chamber was also found to depend on the atmospheric conditions. The maximum drying rate was obtained at periods between 1200 and 1400 hrs Nigeria local time during which the temperature within the solar dryer is also maximum. Temperature within the solar dryer reached up to 62°C. The solar collector efficiency was 52.0% while the drying efficiency was 21.9%.Peer reviewe

Causal relationship between material price fluctuation and project’s outturn costs

Purpose: A section of project management literature attributes overruns to estimators’ deceit and delusion. An example of this is Flyvbjerg’s theorisation of strategic misrepresentation and optimism bias. To show that such a notion is not true entirely, the study elicits evidence relating to how costs of projects often fluctuate erratically as prices of construction materials change throughout contract cycle times. The purpose of this paper is to examine the causal relationships between persistent changes in prices of construction materials and project’s outturn costs. Design/methodology/approach: The authors obtained and analysed price data of construction materials published in a Nigerian national daily in the 16 years between 2000 and 2015. Additional data were obtained from a quantity surveying firm to validate the archival data on material prices, and to compare the firm’s robust database of project estimates and the corresponding outturn costs of specific building elements (detailed in the study). The goal of the analysis is to explore spontaneity and causal impact in the relationship between changes in prices of construction materials and project costs. Kolmogorov-Smirnov and Anderson-Darling tests were used to obtain the probability distributions of the causal relationships. Findings: Findings show disproportionate positive correlations between changes in material prices and outturn costs in Nigeria. An important dimension to this, however, is that although fluctuations in material costs often trigger variations to project costs, outturn price only accounts for about one-third of actual cost variability. Recovery of costs, not least profit making, under these conditions is a complex process. Originality/value: This paper concludes that dynamism in cost attributes is neither a deceit nor a delusion; understanding and tolerating them is not a systemic weakness, rather an essential key to project success and stakeholder satisfaction. Findings from the study also bring measured certainties to the transformation of variable costs into fixed price outcomes, an important consideration that will help contract estimators and project managers to understand the likelihood of fluctuation in material costs and how these might trigger variability in project costs

Evaluation of kinetic parameters of traps in thermoluminescence phosphors

A method for evaluating trap depth E, order of kinetics b and frequency factor s from a thermoluminescence (TL) glow peak has been developed. The method is based on using intensities and temperatures at any three points on the glow peak. Unlike similar techniques that provide no expression for frequency factor, the present formulation provides such an expression. The expression does not require knowledge of the temperature at which maximum intensity occurs, a parameter not usually known accurately from experimental glow peak data. For the method, it is found that use of points in the ascending part of the glow peak where the intensities are less than 10% maximum intensity gives parameter values closest to the true ones. Possible reasons for getting less accurate results when points are taken beyond this region are discussed. Values of the activation energy calculated using the present technique were always close to the true value. However, the frequency factor only approaches the true value as the dose given to the sample approaches saturation. When the three data points are selected in the initial-rise region, the equation for evaluating E in the method described in this paper becomes a two-point version of the initial-rise method. The advantage of the present technique over the initial-rise method is that it also gives b and hence s. The method is used to analyse the TL glow curve of a gamma-irradiated sample from Ijero-Ekiti, Nigeria

TOXICOLOGICAL EVALUATION OF FERMENTED LIQUOR AND METHANOLIC EXTRACT OF BENISEEDS IN ALBINO RATS

The toxicological evaluation of fermented beniseed liquor and the methanolic extract were assessed in-vivo using young albino rats. They were fed with a dose of 0.75 ml at 100mg/ml of the extract and 0.75 ml at 100mg/ml of the fermented liquor respectively for three weeks (21 days) after which their vital organs were assessed histopathologically. The result of the histopathological analyses showed that the extract and fermented liquor caused no form of distortion, necrosis, lesions or haemorrhage on the heart, the cardiac muscles‟ striata were more strengthened by the fermented liquor when compared with the control and the one fed with the extract which showed homogenous muscle fibres and slight inflammatory cell infiltrations. The liver had its sinusoids in place and showed no form of necrosis, neither karyolysis nor any thickening nuclear structures. The kidneys had normal interstitial cells without tubular necrosis and intestine showed a well formed intestinal villi without any erosion of the cells while the spleen showed well formed dark green cells. Therefore, both the beniseed methanol extract and fermented liquor had no deleterious effect on vital organs and are fit for consumption

The Effect of Temperature on the Antibacterial and Physicochemical Properties of Fermenting Beniseeds

The effect of temperature on the antibacterial property of fermenting beniseed was assessed on six diarhoeagenic bacteria by keeping the fermenting seeds at 40C and 290C respectively. Both the liquor and the slurry were used in this study. The pH, total titratable acidity, microbial load and the microflora of the samples kept at the two different temperatures was determined daily for 7 days. The results showed that the liquor kept at 290C had its highest antibacterial activities after 24hrs of fermentation while the sample kept at 40C had its highest antibacterial activities after 72hrs of fermentation. The highest inhibitory effect was observed on B. cereus with zone diameter of 42mm by the sample kept at 290C and 36mm the sample kept at 40C. This result, when compared with standard commercial antibiotics showed that the fermenting liquor is more effective against four of the six bacteria used. The microbial load of the fermenting liquor increased from 2.4 x104 cfu/ml to 9.2 x106cfu/ml in the sample kept at 290C and 2.4 x104 cfu/ml to 2.8 x105 cfu/ml in the sample kept at 40C by day 4. Microorganisms found to be associated with the fermentation are Lactobacillus acidophilus, Pediococcus cerevisiae and Leuconostoc mesenteroides. The pH of the fermenting liquor decreased from 5.50 at day 0 to 4.90 by day 4 for the sample kept at 40C while it decreased to 3.80 by day 4 for the sample kept at 290C. The total titratable acidity for the sample kept at 40C was highest by day 1 with a value of 27.00 and lowest by day 6 with a value of 10.00 while the one kept at 290C recorded the highest value of 56.10 by day 1 and lowest value of 15.50 by day 4. Since the fermented liquor significantly inhibited the growth of the test organisms used, it is therefore suggested that in the absence of antibiotics, fermented beniseed liquor can be used to treat diarrhoea within 24hours in rural areas where they may not be quick access to conventional antibiotics and can be used up to seven days when preserved in refrigerator to combat diarrhoea caused by these organisms

Evaluation of beniseed extract and fermented liquor in treatment of diarrhoea in albino rats infected with Salmonella typhi

The efficacy of fermented beniseed liquor and the methanol extract in treating diarrhoea caused by Salmonella typhi in albino rats orogastrically infected with the bacteria was assessed. At the end of the experiment, haematological, biochemical and liver functioning tests were performed on the blood from the animals. The results obtained from this analysis showed that the selected organism have high infectivity dose, caused a significant reducing effect on the weight of the albino rats and negative effect on the hematological and biochemical parameters assessed. Treatment of infected animals with the fermented liquor and methanol extract of beniseeds showed that both caused a significantly quick recovery of the infected animals from diarrhoea within five days of treatment. However, the rate of recovery was faster with the group of infected rats treated with the fermented beniseed liquor than the extract. Also, treatment with methanol extract of beniseeds also caused a significant increase in the cholesterol level of the blood from the animals. The results obtained from these analyses showed that beniseed have therapeutic properties and that the fermented form is more effective and can be used to treat diarrhoea caused by the selected bacteria used in this study in albino rats

BENISEEDS (Sesamum indicum Linn.) PREPARATION TREATMENTS THAT AFFECT PROXIMATE ANALYSIS, PHYTOCHEMICAL, AND MINERAL VALUES

Beniseeds, also called sesame seed can be prepared in different ways to alter its nutritive and medicinal value. Here, beniseeds were prepared by roasting, boiling, and open fermentation. The proximate analysis compositon, mineral content, and phytochemical quantities varied by preparation treatment relative to the untreated fresh seeds. Open fermentation best decreased anti-nutrient and alkaloid quantities while simultaneously increasing the extractable protein content. These results provide a nutritional data base for a local seed stock and quantitatively demonstrate how preparative techniques can be applied to increase the human consumption value of beniseeds as well as its medicinal properties

THE IMMUNOSTIMULATORY POTENTIAL OF FERMENTED BENISEEDS (SESAMUM INDICUM LINN) LIQOUR ON ALBINO RATS

The immune-stimulatory potential of natural liquid fermentation of beniseed liquor was assessed in-vivo using young adult albino rats. They were fed with a specific volume of the liquor at 100mg/ml for a period of three weeks after which their blood was subjected to haematological and biochemical analyses. The haematological assay for the biosafety analyses of the liquor on the albino rats showed that the liquor significantly increased the blood parameters when given a dose of 0.75ml at 100mg/ml daily. The biochemical analyses of the blood of the albino rats used showed that the liquor caused significant increase in the level of bicarbonate, urea, uric acid and calcium. The liver functioning tests for the rats showed that the liquor caused a little increase in the serum total protein and alkaline phosphatase without any significant rise in the cholesterol level. The results obtained from these in-vivo analyses of fermented beniseed liquor has shown that beniseeds possess excellent nutraceutic properties with good immunostimulatory potential and that it can be used as a good antidiarrhoeagenic agent

Periodicity, Stability, and Boundedness of Solutions to Certain Second Order Delay Differential Equations

The behaviour of solutions to certain second order nonlinear delay differential equations with variable deviating arguments is discussed. The main procedure lies in the properties of a complete Lyapunov functional which is used to obtain suitable criteria to guarantee existence of unique solutions that are periodic, uniformly asymptotically stable, and uniformly ultimately bounded. Obtained results are new and also complement related ones that have appeared in the literature. Moreover, examples are given to illustrate the feasibility and correctness of the main results