62 research outputs found

    Effect of Displacement on Pressure Distribution in Cake Expression

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    The principle underlying expression basically involves the separation of a solid from the liquid in which it is suspended by passing the mixture through a porous medium with pore sizes too small to allow the passage of the solid particles at an applied pressure. The analytical method of the finite element method has been used to determine the relationship between pressure distribution and displacement distribution along sludge cake height in a filter press expression process. The finite element formulation basically involves the properties of the sludge in question as distinguished from other solution. The solution domain was idealized as a one-dimensional quadratic shape function for the purpose of this analysis and the displacement function formulation method were employed in solving the pressure distribution. It was discovered that pressure increases with an increase in displacement of the cake at different time of expression. It was also discovered that pressure increases simultaneously with displacement as the time of expression increases. The ranges of displacement in a sludge cake height with increase time of expression increases with a decrease in sludge depth, hence impacting positively of the effective pressure. The displacement increases continuously with increase time of expression

    SLUDGE DEWATERING SUBJECTED TO CONSTANT VACUUM PRESSURE: A MODELLING APPROACH

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    Sludge is often generated from the treatment of wastewater and it is essential to reduce its volume before disposal into the environment through dewatering. This helps to reduce the cost of final sludge disposal. This study was therefore aimed at developing a model for the draining time of sludge through the application of vacuum pressure. A vacuum filtration experiment was performed on sewage sludge collected from the wastewater treatment plant situated at the University of Nigeria, Nsukka. The sludge sample was poured into Buchner funnel apparatus and the volume of the filtrate collected was noted at a certain time interval until the end of the experiment. The specific resistance values were obtained using the newly derived-, modified-, and Carman’s-equation, respectively. A comparative study was carried out on the three values obtained and the results showed that the newly derived equation gave the best result. Overall, the newly derived equation demonstrated conformity with Carman’s equation and can be used for sludge dewatering investigation. This paper covers a relevant subject within the field of waste treatment processes, namely the dewatering of sludge from wastewater treatment system and on a large scale, can aid in producing cost effective mechanism that makes it more possible for developing nations to incorporate adequate and effective sanitation

    Skin Cancers Among Albinos at a University Teaching Hospital in Northwestern Tanzania: A Retrospective Review of 64 Cases.

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    Skin cancers are a major risk associated with albinism and are thought to be a major cause of death in African albinos. The challenges associated with the care of these patients are numerous and need to be addressed. The aim of this study was to outline the pattern and treatment outcome of skin cancers among albinos treated at our centre and to highlight challenges associated with the care of these patients and proffer solutions for improved outcome. This was a retrospective study of all albinos with a histopathological diagnosis of skin cancer seen at Bugando Medical Centre from March 2001 to February 2010. Data collected were analyzed using descriptive statistics. A total of 64 patients were studied. The male to female ratio was 1.5:1. The median age of patients was 30 years. The median duration of illness at presentation was 24 months. The commonest reason for late presentation was financial problem. Head and the neck was the most frequent site afflicted in 46(71.8%) patients. Squamous cell carcinoma was the most common histopathological type in 75% of cases. Surgical operation was the commonest modality of treatment in 60 (93.8%) patients. Radiotherapy was given in 24(37.5%) patients. Twenty-seven (42.2%) of the patients did not complete their treatment due to lack of funds. Local recurrence following surgical treatment was recorded in 6 (30.0%) patients. Only thirty-seven (61.7%) patients were available for follow-up at 6-12 months and the remaining patients were lost to follow-up. Skin cancers are the most common cancers among albinos in our environment. Albinism and exposure to ultraviolet light appears to be the most important risk factor in the development of these cancers. Late presentation and failure to complete treatment due to financial difficulties and lack of radiotherapy services at our centre are major challenges in the care of these patients. Early institution of preventive measures, early presentation and treatment, and follow-up should be encouraged in this population for better outcome

    Apium plants: Beyond simple food and phytopharmacological applications

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    Apium plants belong to the Apiaceae family and are included among plants that have been in use in traditional medicine for thousands of years worldwide, including in the Mediterranean, as well as the tropical and subtropical regions of Asia and Africa. Some highlighted medical benefits include prevention of coronary and vascular diseases. Their phytochemical constituents consist of bergapten, flavonoids, glycosides, furanocoumarins, furocoumarin, limonene, psoralen, xanthotoxin, and selinene. Some of their pharmacological properties include anticancer, antioxidant, antimicrobial, antifungal, nematocidal, anti-rheumatism, antiasthma, anti-bronchitis, hepatoprotective, appetizer, anticonvulsant, antispasmodic, breast milk inducer, anti-jaundice, antihypertensive, anti-dysmenorrhea, prevention of cardiovascular diseases, and spermatogenesis induction. The present review summarizes data on ecology, botany, cultivation, habitat, medicinal use, phytochemical composition, preclinical and clinical pharmacological efficacy of Apium plants and provides future direction on how to take full advantage of Apium plants for the optimal benefit to mankind.N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the strategic project ref. UID/BIM/04293/2013 and “NORTE2020-Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)

    Paving Plant-Food-Derived Bioactives as Effective Therapeutic Agents in Autism Spectrum Disorder

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    Autism spectrum disorder (ASD) is a neurodevelopmental disorder, where social and communication deficits and repetitive behaviors are present. Plant-derived bioactives have shown promising results in the treatment of autism. In this sense, this review is aimed at providing a careful view on the use of plant-derived bioactive molecules for the treatment of autism. Among the plethora of bioactives, curcumin, luteolin, and resveratrol have revealed excellent neuroprotective effects and can be effectively used in the treatment of neuropsychological disorders. However, the number of clinical trials is limited, and none of them have been approved for the treatment of autism or autism-related disorder. Further clinical studies are needed to effectively assess the real potential of such bioactive molecules.N.C.-M. acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017)

    Geographical information system and predictive risk maps of urinary schistosomiasis in Ogun State, Nigeria

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    <p>Abstract</p> <p>Background</p> <p>The control of urinary schistosomiasis in Ogun State, Nigeria remains inert due to lack of reliable data on the geographical distribution of the disease and the population at risk. To help in developing a control programme, delineating areas of risk, geographical information system and remotely sensed environmental images were used to developed predictive risk maps of the probability of occurrence of the disease and quantify the risk for infection in Ogun State, Nigeria.</p> <p>Methods</p> <p>Infection data used were derived from carefully validated morbidity questionnaires among primary school children in 2001–2002, in which school children were asked among other questions if they have experienced "blood in urine" or urinary schistosomiasis. The infection data from 1,092 schools together with remotely sensed environmental data such as rainfall, vegetation, temperature, soil-types, altitude and land cover were analysis using binary logistic regression models to identify environmental features that influence the spatial distribution of the disease. The final regression equations were then used in Arc View 3.2a GIS software to generate predictive risk maps of the distribution of the disease and population at risk in the state.</p> <p>Results</p> <p>Logistic regression analysis shows that the only significant environmental variable in predicting the presence and absence of urinary schistosomiasis in any area of the State was Land Surface Temperature (LST) (B = 0.308, p = 0.013). While LST (B = -0.478, p = 0.035), rainfall (B = -0.006, p = 0.0005), ferric luvisols (B = 0.539, p = 0.274), dystric nitosols (B = 0.133, p = 0.769) and pellic vertisols (B = 1.386, p = 0.008) soils types were the final variables in the model for predicting the probability of an area having an infection prevalence equivalent to or more than 50%. The two predictive risk maps suggest that urinary schistosomiasis is widely distributed and occurring in all the Local Government Areas (LGAs) in State. The high-risk areas (≥ 50% prevalence) however, are confined to scatter foci in the north western part of the State. The model also estimated that 98.99% of schools aged children (5–14 years) are living in areas suitable for urinary schistosomiasis transmission and are at risk of infection.</p> <p>Conclusion</p> <p>The risk maps developed will hopefully be useful to the state health officials, by providing them with detailed distribution of urinary schistosomiasis, help to delineate areas for intervention, assesses population at risk thereby helping in optimizing scarce resources.</p

    African Jointfir (Gnetum africanum) and Editan (Lasianthera africana) leaf alkaloid extracts exert antioxidant and anticholinesterase activities in fruit fly (Drosophila melanogaster)

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    Abstract African Jointfir (Gnetum africanum) and Editan (Lasianthera africana) leaves are two leafy green veggies with several nutritional and medicinal properties. Alzheimer's disease (AD) is a form of neurodegeneration that is believed to cause dementia in affected individuals. The quest for alternative treatments has necessitated the exploitation of plants' secondary metabolites. Plant alkaloids have recently demonstrated relevance in the management of a variety of neurodegenerative disorders; although there is limited information on the neuroprotective properties of alkaloids from various tropical green leafy vegetables with neuroprotective potentials. As a result, this study examined the cholinesterase inhibitory activity and antioxidant potential of alkaloid extracts from the leaves of African Jointfir (G. africanum) and Editan (L. africana). Standard solvent extraction techniques were used to prepare alkaloid extracts. After that, these extracts were characterized using high‐performance liquid chromatography. In vitro acetylcholinesterase inhibition assay for the extracts was also carried out. Subsequently, the alkaloid extracts were included in the diets of these flies (2 and 10 μg/g) for 7 days. Thereafter, treated fly homogenates were assayed for cholinesterase, monoamine oxidase, and antioxidant enzymes (specifically, glutathione‐S‐transferase catalase, and superoxide dismutase) activities, in addition, thiobarbituric acid reactive substance, reactive oxygen species, and total thiol contents. The extracts showed considerable anticholinesterase, antioxidant, and antimonoamine oxidase capabilities, according to the study's findings. Also, HPLC characterization revealed that desulphosinigrin (597,000 ng/100 g) and atropine (44,200 ng/100 g) are the predominating phytochemicals in Editan and African Jointfir respectively. These extracts could serve as potential sources of nutraceuticals with neuroprotective properties which can be used in the treatment/management of Alzheimer's disease

    Modeling and optimization of lucky nut biodiesel production from lucky nut seed by pearl spar catalysed transesterification

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    In 2015, the Worldatlas recorded 50 countries whose source of income is fossil fuel and its derivatives. Surprisingly, these countries solely depend on this source of energy up to 100% (Omar, Qatar, Kuwait and Saudi Arabia) because of technology improvement. It's so sadden that apart from its adverse effect on the economics of the countries, fossil fuels harmful effects on the universe cannot be overlooked. Meanwhile, the use of renewable energy as a replacement for fossil fuel and its derivatives are faced by the high oil price, high cost of investment for alternative energy, and unfathomed electricity prices. This research work evaluates desirability of making use of alternative source of energy sources by making use of biomass oil over the use of fossil fuel and its derivatives for electricity generation.Lucky nut is an agricultural non edible seed that was employed as raw material for biofuel production. The non-edible oil was extracted from the seeds and the oil was further converted to Lucky nut biofuel via a heterogeneous based catalyst produced from calcinated pearl spar. For modelling and optimization, design expert coupled with genetic algorithms were used to generate experimental designs so as to correlate the variable factors considered for production.The extraction of Lucky nut seed revealed the optimum production yield of 50.80% (v/v) and the oil is highly unsaturated. Energy Dispersive X-ray Fluorescence Spectrophotometer analyses and scanning electron microscope (SEM) of the calcined catalyst obtained from pearl spar showed the major component found in the pearl spar was K with relative abundance of 58.48%, which favoured the yield of Lucky nut biodiesel (91.00% (v/v)). Based on predicted values, the optimum validated Lucky nut biodiesel by RSMED and ANNED were 89.68% (v/v) and 92.87% (v/v), respectively. Produced properties of biofuel conformed to the biofuel standard.The study concluded that Lucky nut seed is a good source of oil, and its transformation to alternative fuel via a using calcined catalyst proved its fitness as a replacement for fossil fuel

    Development of an NCAM Tuber-Shaped Vegetable Slicing Machine

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    Generally, most agricultural products are not stable immediately when freshly harvested, while their preservative nature varies accordingly especially, vegetables and fruit crops. The need to process and preserve them in a stable form is very important. In processing of some tuber -shaped vegetable crops such as carrot, plantain, cucumber, eggplant, etc., slicing/chipping is usually done traditionally with the aid of knives and other manual methods which are time consuming, thereby exposing processors to dangers of injury, increases drudgery and overall reduces productivity. In respect of these, an NCAM tuber - shaped vegetable slicer was designed, fabricated and evaluated. The performance parameters used for the evaluation are slicing efficiency, slice thickness and percentage damage. IBM SPSS 2.0 was used to analyse the result obtained from the performance evaluation of the tuber – shaped slicer. It was observed that blade thickness had a significant effect on percentage damage and slice thickness, and no effect on slicing efficiency at p≤0.05. 94.74% and 90.99% efficiency was observed at 1.5 mm and 1 mm blade thickness for plantain and cucumber respectively. Furthermore, the highest mean value for percentage damage for plantain was 44.08% at 1.0mm blade thickness, while the highest mean value of percentage damage for cucumber was 24.88% at blade thickness of 1.0mm. This shows that the tuber – shaped vegetable slicing machine performed efficiently.&nbsp; Therefore, tuber-shaped slicing machine is recommended for use by processor of tuber – shaped crops into other stable form. &nbsp
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