142 research outputs found
Study of the Structural and Mechanical Properties of Recycled High Density Polyethylene/Palm Kernel Shell Ash Bio-Composite
This study examined the structure and mechanical properties of recycled high density polyethylene(RHDPE)/palm kernel shell ash (PKSA) bio-composite. The reinforcement was added to the polymer matrix in concentrations of 5, 10, 15, 20 and 25wt% and particle sizes of 100, 150, 200, 250, 300µm. The composite samples were produced using injection moulding technique and subjected to mechanical and tribological property tests for percentage elongation, ultimate tensile strength, and hardness. The structure of the composite samples was analyzed using an optical metallurgical microscope. Results of the structural analysis revealed that the reinforcement of small particle size (100µm) formed a better interfacial bond with the polymer matrix compared with that of other particles sizes. The structural analysis also revealed uniform distribution of hard and brittle particles of the reinforcement in the polymer matrix. Mechanical test results showed that addition of palm kernel shell ash to the polymer matrix decreased its percentage elongation and impact strength by 24.5% and 22% respectively but significantly increased the tensile strength and hardness by 107.9% and 72% respectively. The ultimate tensile strength, and hardness of the developed composite increased with decrease in reinforcement particle size. Maximum ultimate tensile strength of 131MPa was obtained by the RHDP containing 10wt% PKSA of 100µm particle size while maximum hardness value of 86BHN was obtained at 25wt% palm kernel shell ash of 100µm particle size addition. Palm kernel shell ash reinforced recycled high density polyethylene bio-composite of improved mechanical properties that can be applied in production of engineering components. Keywords: Palm kernel shell ash, RHDPE, Percentage elongation, Ultimate tensile strength, Hardness. DOI: 10.7176/CPER/62-05 Publication date: January 31st 202
Statistical Modelling of Drying Characteristics of Unripe Plantain (Musa Paradisiaca) Slices
This work is designed to carry out the statistical modelling of the drying characteristics of unripe plantain (Musa paradisiaca) slices and to study the effect of drying temperature and slice thickness on drying characteristics. The test samples were dried in a laboratory scale oven dryer at varying temperatures of 700C, 800C and 900C, and different slice thicknesses of 2mm, 3mm and 4mm.The result obtained indicated that drying temperature and slice thickness had significant effect on drying rate and hence moisture profile. The moisture ratio – drying time data obtained were fitted to ten thin layer drying models. The fit quality obtained with each model was evaluated using statistical tests namely; coefficient of determination (R2), root mean square error (RMSE), reduced chi-square (X2), and standard error of estimate (SEE). Although most of the models fitted quite well to the experimental data, Page and Modified Page models showed the highest average R2 and the lowest average RMSE, X2 and SEE values. Page and modified Page models were selected and found suitable to represent the drying characteristics of unripe plantain slices and predict drying times
ESTIMATION OF GLOBAL SOLAR RADIATION AT CALABAR USING TWO MODELS
In this study, the estimation of global solar radiation with Meteorological parameters at Calabar- Nigeria latitude 40N and longitude 80 E were carried out. The daily mean temperature and relative humidity for seventeen years (1991 to 2007) from Nigerian Meteorological Agency, Federal Ministry of Aviation, Oshodi, Lagos were used. The global solar radiation data were collected courtesy of Renewable Energy for Rural Industrialization and Development in Nigeria. Two models (multiple regression and artificial neural network) were used for the estimation. Comparing the graphs of correlation equation 4 and 5, and equation 6 and 7 of the first model, it is obvious that the first order correlation has better estimation power. Looking at the overview of all the Figures (1 -5A), is it is clear that the two models used in this study has estimation capacity, but Figure 5A shows better correlation with the measured values, which indicates that artificial neural network model is a better model for estimation. Therefore has been recommended for global solar radiation estimation at Calabar and its environs with similar weather condition. Alternatively, first order regression should be use for estimation in the absent of artificial neural network. Keywords: artificial neural network, regression, model, global solar radiatio
Change in Lipid Quality of Tilapia Fish (Oreochromis niloticus) After Different Heat Treatments
Tilapia fish (Oreochomis niloticus) has been considered to be popular among the freshwater fishes, economically cheap and more abundant in Nigeria. For this reason, a study was conducted on the effect of traditional processing methods on fatty acid composition of Oreochomis niloticus using electric oven (control), sawdust, melon husk and rice bran as different heat treatments. Fatty acid composition was determined using standard analytical technique. The result showed that palmitic and oleic acids had the highest concentrations among saturated and unsaturated fatty acids in all the processed samples, respectively. It was also revealed that samples of Oreochomis niloticus recorded decrease in total saturated fatty acid (TSFA) with various heat treatments whereas the same heat treatments enhanced the components of total unsaturated fatty acids (TUFA) and total essential fatty acid (TEFA). It was found that levels of ratio of n–6 PUFA to n–3 PUFA and oleic to linoleic which are used as biomedical index are desirable in all the processed samples of Oreochomis niloticus oils. However, heat treatment using sawdust was proven to be of good economic potential. Keywords: Oreochomis niloticus, agricultural wastes, fatty acids
Knowledge-Attitudes-Practices About Malaria Among Communities in Southern Benin
Malaria still remains the main public health problem in Benin. We explored the determinants that influenced malaria treatment as well as protective behaviors, to generate a framework of useful ideas as alternative strategies against malaria. A cross-sectional survey of the knowledge, attitudes and practices (KAP) was conducted at Hozin, Vakon and Agblangandan districts in southern region of Benin. Descriptive statistics were computed and mixed logistic regression helped evaluating the relationship between frequency of each category of severity of malaria and sex group, educational level, treatment, means of self-protection against mosquitoes and identification of the cause of malaria. A significant proportion 750 (81.3%) (p<0.001) of participants stated that malaria was caused by mosquitoes. The respondents who mentioned sun as the cause of malaria, have trivialized more malaria in a proportion of about 59.30% (OR=2.67 [95% CI 1.61-4.44]) followed by those who have reported the cause of body weakness (43.68%) (OR=2.97 [95% CI 1.68-5.28]). Poor knowledge justifies the trivialization of the disease and poor management of malaria control means. National Malaria Control Programs should improve access to education, especially for women and could help improving prevention and control behaviours against malaria in communities
Assessment of animal African trypanosomiasis (AAT) vulnerability in cattle-owning communities of sub-Saharan Africa
Background:
Animal African trypanosomiasis (AAT) is one of the biggest constraints to livestock production and a threat to food security in sub-Saharan Africa. In order to optimise the allocation of resources for AAT control, decision makers need to target geographic areas where control programmes are most likely to be successful and sustainable and select control methods that will maximise the benefits obtained from resources invested.
Methods:
The overall approach to classifying cattle-owning communities in terms of AAT vulnerability was based on the selection of key variables collected through field surveys in five sub-Saharan Africa countries followed by a formal Multiple Correspondence Analysis (MCA) to identify factors explaining the variations between areas. To categorise the communities in terms of AAT vulnerability profiles, Hierarchical Cluster Analysis (HCA) was performed.
Results:
Three clusters of community vulnerability profiles were identified based on farmers’ beliefs with respect to trypanosomiasis control within the five countries studied. Cluster 1 communities, mainly identified in Cameroon, reported constant AAT burden, had large trypanosensitive (average herd size = 57) communal grazing cattle herds. Livestock (cattle and small ruminants) were reportedly the primary source of income in the majority of these cattle-owning households (87.0 %). Cluster 2 communities identified mainly in Burkina Faso and Zambia, with some Ethiopian communities had moderate herd sizes (average = 16) and some trypanotolerant breeds (31.7 %) practicing communal grazing. In these communities there were some concerns regarding the development of trypanocide resistance. Crops were the primary income source while communities in this cluster incurred some financial losses due to diminished draft power. The third cluster contained mainly Ugandan and Ethiopian communities which were mixed farmers with smaller herd sizes (average = 8). The costs spent diagnosing and treating AAT were moderate here.
Conclusions:
Understanding how cattle-owners are affected by AAT and their efforts to manage the disease is critical to the design of suitable locally-adapted control programmes. It is expected that the results could inform priority setting and the development of tailored recommendations for AAT control strategies
IPSE, an abundant egg-secreted protein of the carcinogenic helminth Schistosoma haematobium, promotes proliferation of bladder cancer cells and angiogenesis
Background
Schistosoma haematobium, the helminth causing urogenital schistosomiasis, is a known bladder carcinogen. Despite the causal link between S. haematobium and bladder cancer, the underlying mechanisms are poorly understood. S. haematobium oviposition in the bladder is associated with angiogenesis and urothelial hyperplasia. These changes may be pre-carcinogenic events in the bladder. We hypothesized that the Interleukin-4-inducing principle of Schistosoma mansoni eggs (IPSE), an S. haematobium egg-secreted “infiltrin” protein that enters host cell nuclei to alter cellular activity, is sufficient to induce angiogenesis and urothelial hyperplasia. Methods: Mouse bladders injected with S. haematobium eggs were analyzed via microscopy for angiogenesis and urothelial hyperplasia. Endothelial and urothelial cell lines were incubated with recombinant IPSE protein or an IPSE mutant protein that lacks the native nuclear localization sequence (NLS-) and proliferation measured using CFSE staining and real-time monitoring of cell growth. IPSE’s effects on urothelial cell cycle status was assayed through propidium iodide staining. Endothelial and urothelial cell uptake of fluorophore-labeled IPSE was measured. Findings: Injection of S. haematobium eggs into the bladder triggers angiogenesis, enhances leakiness of bladder blood vessels, and drives urothelial hyperplasia. Wild type IPSE, but not NLS-, increases proliferation of endothelial and urothelial cells and skews urothelial cells towards S phase. Finally, IPSE is internalized by both endothelial and urothelial cells. Interpretation: IPSE drives endothelial and urothelial proliferation, which may depend on internalization of the molecule. The urothelial effects of IPSE depend upon its NLS. Thus, IPSE is a candidate pro-carcinogenic molecule of S. haematobium.
Summary
Schistosoma haematobium acts as a bladder carcinogen through unclear mechanisms. The S. haematobium homolog of IPSE, a secreted schistosome egg immunomodulatory molecule, enhances angiogenesis and urothelial proliferation, hallmarks of pre-carcinogenesis, suggesting IPSE is a key pro-oncogenic molecule of S. haematobium
Persistent orocutaneous and anal fistulae induced by nicorandil: a case report
<p>Abstract</p> <p>Introduction</p> <p>Although nicorandil is prescribed widely, awareness of its potential to cause serious complications to the gastrointestinal tract mucosa is limited. Whilst nicorandil-induced oral and anal ulceration is well documented in the literature, nicorandil-induced fistulation is not. This is the first report in the literature of a single patient demonstrating simultaneous orocutaneous and anal fistulae during nicorandil therapy. Two separate cases of orocutaneous and anal fistulae associated nicorandil usage have previously been documented in specialist journals.</p> <p>Case presentation</p> <p>A 71-year-old Caucasian man presented with a 3-year history of concurrent orocutaneous and anal fistulae. He had been exposed to 30 mg twice-daily nicorandil therapy for 4 years. Both fistulae responded poorly to intensive and prolonged conventional treatment but healed promptly on reduction and eventual withdrawal of nicorandil therapy.</p> <p>Conclusion</p> <p>Management of resistant cases of orocutaneous and anal fistulae in patients on high-dose nicorandil therapy may be impossible without reduction or even withdrawal of nicorandil.</p
A Tale of Two Markets: How Lower-end Borrowers Are Punished for Bank Regulatory Failures in Nigeria
In 2009, the Nigerian banking system witnessed a financial crisis caused by elite borrowers in the financial market. Regulatory response to the Nigerian crisis closely mirrored the international response with increased capital and liquidity thresholds for commercial banks. While the rise of consumer protection on the agenda of prudential supervisors internationally was logical in that consumer debt was the main cause of the global recession, the Nigerian banking reforms of 2009 disproportionately affected access by poorer consumers, who ironically had little to do with the underlying causes of the crisis. As lending criteria become more stringent, poorer consumers of credit products are pushed into informal markets because of liquidity-induced credit rationing. Overall, consumer protection is compromised because stronger consumer protection rules for the formal sector benefits borrowers from formal institutions who constitute the minority of borrowers in all markets. While the passage of regulation establishing credit bureaux and the National Collateral Registry will, in theory, ease access to credit especially by lower-end borrowers, the vast size of the informal market continues to compound the information asymmetry problem, fiscal policies to tackle structural economic issues such as unemployment and illiteracy remain to be initiated, and bank regulators continue to pander to elite customers with policy responses that endorse too big to fail but deems lower-end consumers too irrelevant to save. The essay concluded that addressing the wide disparity in access to credit between the rich and poor through property rights reforms to capture the capital of the informal class, promoting regulation to check loan concentration, and stimulating competition by allowing Telecommunication Companies (TELCOs) and fintech companies to carry on lending activities because of their superior knowledge of lower-end markets will facilitate greater access. The risk of systemic failure deriving from consumer credit in Nigeria is insignificant compared to the consumer vulnerabilities resulting from the exposure of consumers to unregulated products in the informal market
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