175 research outputs found
An investigation into the suitability of selected lesser utilised Ghanaian hardwoods for use as outdoor furniture and decking
The potential for using the Ghanaian lesser utilised hardwoods esa (Celtis mildbraedii), denya (Cylicodiscus gabunensis) and dahoma (Piptadeniastrum africana) for garden furniture and decking in the UK is investigated. Specific properties are examined using field and laboratory experiments against reference species; iroko (Milicia excelsa), African mahogany (Khaya ivorensis), teak (Tectona grandis) and European oak (Quercus robur). The effectiveness of decking and teak oil coatings at reducing weathering defects is described.
With weathering colours of all species changed over the six month exposure period though the greatest rate of change is seen in iroko and oak. There is an increase in lightness (L* value) and greying (a* and b* values). Oil treatments delay the rate of colour change but do not prevent it. Oil treatments reduce checking during weathering which is worse in oak, esa and denya. Analysis of samples during outdoor exposure using FTIR show a loss in lignin at the surface, with the absorbance peak at (1505cm)-1 absent following 1 month for untreated samples and two months for oiled samples. Scanning electron microscopy revealed that teak and deck oil formed thin films on the surfaces of wood but do not coat vessel lumens. Following six months exposure a number of defects were apparent, including raised wood fibres, fungal colonisation and cell wall and pit checking. Defects are observed in coated and uncoated wood.
Natural durability using the method described in BS EN 350-1 show denya to be very durable, dahoma moderately durable and esa not durable. Field exposure shows esa is liable to blue stain in service though no decay is detected in lap joints after nine months exposure
Heterogeneous returns and the persistence of agricultural technology adoption
In this paper we explore whether low rates of sustained technology use can be explained by heterogeneity in returns to adoption. To do so we evaluate impacts of the Cocoa Abrabopa Association, which provided a package of fertilizer and other inputs on credit to cocoa farmers in Ghana. High estimated average productive impacts for treated farmers are found to be consistent with negative economic profits for a substantial proportion of the treated population. By constructing an individual specific measure of returns,we demonstrate that low realized returns among adopters are associated with low retention rates, even after conditioning on output levels and successful repayment. The results are consistent with the hypothesis that high average returns mask substantial and persistent heterogeneity, and that farmers experiment in order to learn about their idiosyncratic returns.
Coconut Coir and Beans Straw as Substrates for Mushroom Growth
Coconut coir and beans straw could blend well for mushroom production. This would increase the biomass use and also serve as a way of recycling the agricultural wastes. The project was carried out to evaluate the mycelial growth rate, yield and cost benefit analysis of oyster mushroom (Pleurotus ostreatus) cultivation on sole coconut coir (CC), sole bean straw (BS), and a 2:3 ratio mixture of BS and CC (BS:CC Mix) as substrates. Each substrate type was subjected to 3 different composting periods of a day (no compost), 7days, and 14 days. Randomized complete block design with three replications was used for the experimental design. The best mushroom performance was obtained in the BS:CC Mix substrates, recording highest yields in the range of 43.2 - 47.4 g/kg substrate; the greatest biological efficiencies of 11.0 - 22.9% as well as the highest returns of 200.9 - 229.8%. The results indicated that beans straw could be an effective supplement to coconut coir and other highly lignified substrates for mushroom production. Keywords: coconut coir; beans straw; mycelia; cost benefit analysis; mixed substrate
Comparative Analysis of Efficiency of Fibonacci Random Number Generator Algorithm and Gaussian Random Number Generator Algorithm in a Cryptographic System.
Random Numbers determine the security level of Cryptographic Applications as they are used to generate padding schemes in the encryption and decryption process as well as used to generate cryptographic keys. The more randomness in the numbers a generator generates the more effective the cryptographic algorithm, and the more secured it is to be used for protecting confidential data. Sometimes developers find it difficult to determine which Random Number Generators (RNGs) can provide a much secured Cryptographic System for secured enterprise application implementations. Two of such random number generators include the Fibonacci Random Number Generator and the Gaussian Random Generator. The researchers sought to determine, between these two, the better to be used for improving data security in cryptographic software systems. The researchers employed statistical tests like Frequency test, Chi-Square test, Kolmogorov-Smirnov test on the first 100 random numbers between 0 and 1000 generated using the above generators. The research concluded that Fibonacci Random Number Generator is more efficient than the Gaussian Random Number Generator and therefore recommended the choice of Fibonacci Random Number Generator when choosing between the two for use in a cryptographic system for better data security. Keywords: Cryptographic Algorithms, Random Number Generators, encryption, decryptio
Metal Oxide Polymer Nanocomposites in Water Treatments
Recently, several pollutants such as dyes, pharmaceuticals and phenolic compounds, which can cause toxic effects to human health, have identified in water resources. Water pollution has extensively studied and several conventional techniques, such as chemical treatment, adsorption, biological treatment, and membrane-based separation, have adopted for pollutants removal from wastewater/ water resources. However, these techniques had led to the production of soluble refractory organic compounds and health-threatening bacteria that are hard to be removed. Recently, photocatalysis has considered as one of the most viable technology for water treatment using sunlight to eliminate harmful bacteria and pollutants owing to its cost-effectiveness and high efficiency. Metal oxide and polymers have become promising materials for water treatment owing to their properties, such as surface mobility, large surface area and superb magnetic and optical properties. This book chapter discusses recent design and synthesis of visible light response polymer/metal oxide nanocomposite through several synthetic strategies for water treatment. The results show that the polymer-metal oxide nanocomposite possesses a superior photodegradation activity toward pollutants under simulated visible light. Major challenges in polymer-metal oxide nanocomposite synthesis and future research perspectives for developing alternate synthesis methodologies are also discussed
Assessing the Life Insurance Industry in Ghana
Insurance has a crucial role to play in every economy. In Ghana, there have been a number of disasters resulting in loss of life and property. This paper attempts to assess the life insurance industry in Ghana through a sample of 330 customers of life insurance companies operating in the Kumasi Metropolis. The study revealed that life insurance companies find it difficult to settle claim payment and subject customers to long processing period while some settlement end up in court. 70% of the customers do not received feedback after lodging complains. These insurance companies however collect their premium promptly. Keywords: insurance, effectiveness, satisfaction, claim, premiu
Testing for Randomness in Pseudo Random Number Generators Algorithms in a Cryptographic Application
The most effective cryptographic algorithm has more randomness in the numbers a generator generates, and the more secured it is to be used for protecting confidential data. Sometimes developers find it difficult to determine which Random Number Generators (RNGs) can provide a much secured Cryptographic System for secured enterprise application implementations. This research aims to find an effective Pseudo Random Number Generator algorithm among Fibonacci Random Numbers Generator Algorithms, Gaussian Random Numbers Generator Algorithm, Specific Range Random Numbers Generator Algorithms, and Secure Random numbers Generators, which are the most common Pseudo Random Numbers Generators Algorithms, that can be used to improve the security of Cryptographic software systems. The researchers employed Chi-Square test on the first 100 random numbers between 0 to 1000 generated using the above generators and it concluded that, Fibonacci Random Numbers Generator Algorithms can provide a more secured cryptographic application. Keywords Pseudo Random Number Generators, Randomness, Cryptography, Softwar
Exposing Students to Engineering in Society
Engineering and for that matter engineering training is pivotal in solving problems that confront societies. This paper introduces academia to a course named Engineering in Society run at the College of Engineering of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. The paper also reports on an assessment of the course content, mode of delivery and impacts, and recommends improvements to enhance its learning outcomes. The impact assessment was done through the administration of questionnaires to four hundred and thirty-seven current and immediate past students of the Collegeâs Department of Electrical and Electronic Engineering. The respondents were students in the second, third and fourth years of the BSc Electrical and Electronic Engineering programme as well as its immediate past alumni. The results of the impact assessment show that over 85% of the respondents from the various categories consider the course to be essential for their career development. Between 56.76% and 79.38% of respondents from the various groups are satisfied with the mode of delivery of the course. Not less than 69% of the responds agree to the attainment of at least one of the learning outcomes of the course. The respondents consider the community project component of the course as the most impactful. The study has revealed an increasing trend of students contracting others to do their community projects for them as well as an increasing trend in plagiarism of submitted reports. Among others, the study recommends some revision of the course content and mode of delivery to maximize the impact of the course. Additionally, the university should do away with the submission of reports in printed copy and rather migrate to online submission of reports, with plagiarism checks. The course, with the suggestions made, is recommended for adoption by engineering training institutions
Insecticidal activities and chemical composition of the essential oil from Tarchonanthus camphoratus (L.), leaves against Sitophilus zeamais Motschulsky, and Sitophilus oryzae (L.)
The essential oil of Tarchonanthus camphoratus dry leaves growing in Kwa-Zulu Natal, South Africa was obtained by hydrodistillation and evaluated for its repellent effect, contact and fumigation toxicity against both Sitophilus zeamais and Sarocladium oryzae. Chemical composition of the essential oil was analysed by gas chromatography mass spectrometry (GC/MS). The study revealed that the essential oil of T. camphoratus had no contact and fumigation toxicity against stored insect pests, S. zeamais and S. oryzae. The oil, however, showed good repellent activity of over 50% after 24 h for all the concentrations used on both S. zeamais and S. oryzae. A total of 27 compounds accounting for 73% of the total oil composition were identified of which sesquiterpene hydrocarbons, (59.18%), were the most dominant. These results suggest that the essential oil of T. camphoratus could be considered a potential control agent of stored grain pests as a repellent
Participation in household decision making and justification of wife beating: evidence from the 2018 Mali Demographic and Health Survey
Background: We assessed the association between women's participation in household decision making and justification of wife beating among married women ages 15â49 y in Mali.
Methods: We employed a cross-sectional study design among 7893 women of reproductive age involving a two-stage sampling technique using version 6 of the Mali Demographic and Health Survey (MDHS) data, which was conducted in 2018.
Results: Approximately 37% participated in at least one household decision while 23.4% reported that they would not justify wife beating in any of the stated circumstances. Women who participated in at least one household decision had lower odds (adjusted odds ratio [AOR] 0.834 [confidence interval {CI} 0.744 to 0.935]) of justifying wife beating. With respect to the covariates, we found that women 45â49 y of age had lower odds of justifying wife beating compared with those ages 15â19 y (AOR 0.569 [CI 0.424 to 0.764]). Women with higher education (AOR 0.419 [CI 0.265 to 0.662]) and those whose husbands had secondary education (AOR 0.825 [CI 0.683 to 0.995]) had lower odds of justifying wife beating. Women who lived in urban areas were less likely to justify wife-beating (AOR 0.328 [CI 0.275 to 0.390]) compared with those who lived in rural areas.
Conclusion: This study suggests that participation in household decision making is associated with a significantly lower rate of justifying wife beating in Mali. These results underscore the need for various interventions to empower women to increase women's participation in decision making to reduce justification of domestic violence
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