226 research outputs found

    Factors Affecting Biogas Production during Anaerobic Decomposition of Brewery effluent- wastewater in a Fluidized Bed Digester.

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    This  work determined the dependency of biogas and carbon (iv) oxide production on microbial concentration X (Cfu/l), hydraulic retention time (HRT), ratio of total volatile fatty acid (TVFA) and total alkalinity K, during anaerobic decomposition of brewery effluent wastewater in a fluidized-bed reactor system. The volume of biogas and carbon (iv) oxide produced were monitored as the treatment time progressed. For  brewery waste water volume of 2 litres treated in the bioreactor, the volume of biogas rich in methane, produced in this work was described as s-curve with initial volume of biogas produced as 0.003l  at 4h HRT and maximum volume of 0.0045l at 8 h HRT.Similarly,0.0033l of carbon(iv)oxide was recorded at 2 h HRT and it achieved its maximum of 0.0042l at 8 h HRT. Total microbial count was conducted on the reactor sample water. The maximum concentration of the gases recorded at 8 h HRT corresponded to the favourable operating environment and good system stability ratio  (VFA/Alkalinity)<0.5 achieved. Key words: Anaerobic decomposition, brewery wastewater, fluidized-bed reactor, Biogas, carbon (iv) oxide

    A Review of Environmental Implications of Dredging Activities

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    Dredging is a global anthropogenic excavation activity of removing sediments from water bodies and depositing it elsewhere. It is a mixed blessing as it has both beneficial and adverse impacts. This paper is on a review of environmental implications of dredging. The objective of the paper is to review previous works by researchers on the environmental consequences of dredging. The method used is a review of academic/journal articles, internet materials, conference / workshop papers, textbooks, bulletins and publicly available materials on dredging activities. The results of the study revealed that previous authors whose works were reviewed have a convergent view that apart from the beneficial impacts of dredging (e.g. keeping waterways navigable, flood and storm protection and provision of materials for road construction and building), it has lots of adverse environmental impacts, including environmental pollution, erosion, widespread hydrological changes, reduction in the population of aquatic lives like destruction of fish spawning grounds and benthic organisms and resuspension of particulate matter column that has elevated levels of lead, copper, zinc and nickel in Phytoplankton. Recommendations of the study include: (1) establishment of environmental legislations and regulations for dredging operation; (2) use of green technology in dredging activities to minimize suspension of sediments and contamination/pollution of dredging environments; and (3) creation of awareness among dredging contractors, regulators and marine communities where dredging take place on the economic and ecological values of the marine ecosystems that are usually very sensitive, fragile and productive

    Label-free quantitative comparison of cerebrospinal fluid glycoproteins and endogenous peptides in subjects with Alzheimer's disease, mild cognitive impairment, and healthy individuals

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    PURPOSE: The goal of this study is to investigate putative molecular dynamic changes in cerebrospinal fluids (CSFs) collected from individuals with mild cognitive impairment (MCI) and Alzheimer's disease (AD) as compared to healthy controls. EXPERIMENTAL DESIGN: The CSF samples from 12 subjects comprised of four cognitively normal individuals and eight patients with MCI and AD, respectively. Two aliquots of each CSF samples (total 1 mL) of each participant are used for this study. Endogenous peptide separations are performed using 10 000 molecular weight cut-off filters followed by LC-MS/MS identification and quantitation while lectin-enrichment chromatography is used to enrich glycoproteins in CSF followed by trypsin digestion and subsequent LC-MS/MS for shotgun identification and label-free quantitation. RESULTS: Using an optimized submicrogram peptide separation with molecular weight cut-off filtration and an in house-constructed database, 645 peptides are identified. Glycoproteins are enriched by lectin affinity chromatography, resulting in 795 identified proteins. The discovery and alterations of proSAAS-derived peptides and transthyretin are described and their roles in AD are discussed. CONCLUSIONS AND CLINICAL RELEVANCE: Comprehensive identification of endogenous CSF peptidome is achieved. Fifteen proteins are found to be differentially expressed among the three groups. The dynamic changes of transthyretin are reported for the first time

    Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries

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    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for carbon soot material is very interesting given the fact that its production cost is away cheaper than activated carbon. The cost of activated carbon is about 15/kgwhereasthecosttomanufacturecarbonsootasabyproductfromlargescalemillingofabundantgraphiteisabout15/kg whereas the cost to manufacture carbon soot as a by-product from large-scale milling of abundant graphite is about 1/kg. Additionally, here, we propose a method that is environmentally friendly with strong potential for industrialization. © 2014 Badi et al.; licensee Springer

    Effect of Luffa cylindrica fiber and particulate on the mechanical properties of epoxy

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    This study examines the effect of addition of Luffa cylindrica fiber (LCF) and Luffa cylindrica particulate (LCP) on the properties of epoxy resin. Luffa cylindrica fiber treated with 8% NaOH and of 2, 4, and 6% weight fraction was used to reinforce epoxy resin via hand lay-up method. Hybridization of the fiber and particulate was also done with the particulate having a constant weight fraction of 10% whereas the fibers were varied as in the mono-reinforced Luffa cylindrica fiber composite. The samples were machined for mechanical and microstructural analysis. Result showed that addition of the reinforcement led to an improvement in mechanical properties. However, the hybrid was seen to showcase better properties compared to the fiber-reinforced composite with the hybrid sample of composition 4 wt% LCF and 10 wt% LCP exhibiting the highest tensile and flexural strength of 13.489 MPa and 20.3 MPa, respectively. Microstructural analysis showed excellent homogeneity with few voids and better adhesion between the reinforcement and matrix. These results show that this composite can find application in the interior and exterior parts of automobiles as well as in household wares like flower pots

    Data on physicochemical properties of borehole water and surface water treated using reverse osmosis [RO] and ultra-violet [UV] radiation water treatment techniques

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    This article present data on reverse osmosis (RO) and ultra-violet (UV) Radiation Water Treatment Techniques effects on the physiochemical properties of a treated surface wa- ter (SW) and borehole water (BHW). The water treatment study which was carried out in Omoku community in River State, lies with latitude 5 °13 ¹N and 5 °22 ¹N and longitude 6 °33 ¹E and 6 °42 ¹North West of the Niger Delta region of Nigeria, an area with over Nine hundred oil wells with over thirteen active oil fields and playing host to three multina- tional companies, due to these activities the water is highly contaminated and causing serious health challenges to the water consumer. Therefore, this research work focus on RO and UV water techniques by applying the physicochemical characteristics method and total Coliform count, with the mechanism to check the influence of both techniques on the pH, temperature, Turbidity, conductivity, Total suspended solids Total dissolved solids of the water for three different samples within the Omoku community. The experiment shows that RO treatment technique produces potable water with reduced mineral content in comparison to the UV treatment

    Assessment of performance indices of selected gas turbine power plants in Nigeria

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    In this study, performance assessment of selected gas turbine power plants in Nigeria was evaluated using performance indices. The results of the study showed that for the period under review (2006–2010), the percentage shortfalls from the target energy in the selected power plants range from 26.33% to 86.61% as against the acceptable value of 5–10%. The capacity factor of the selected power plants varies from 16.88% to 73.67% as against the international value of 50–80%. The plant use factor varies from 45.89% to 97.03% and the utilization factor varies from 6.31% to 93.074% as against the international best practice of over 95%. From this result, it can be concluded that the generating units were underutilized. This is due to inadequate routine maintenance and equipment fault development. The analyses of reliability indicators revealed that the mean time between failures varies from 5.42 to 378.44 h, the mean time to repair varies from 18.3 to 153.88 h and the plant availability varies from 12.86% to 91.31% as against the Institute of Electrical and Electronics Engineers recommended standard of 99.9%. Evaluation of operating figures of the selected power plants revealed that starting reliability (SR) and operating reliability vary from 71.95% to 93.9% and 5.33% to 55%, respectively. The SR of the selected power plants is low in value compared with standard value of 99.9%. The statistical analysis carried out on plant availability revealed that at 95% confidence level; there is a significant difference in availability of the selected power plants. This indicates differences in their systems installation, operation and maintenance. The performance indicator developed to evaluate the performance indices for the selected stations can also be applicable to other power stations in Nigeria and elsewhere. Measures to improve the performance indices of the plants have been suggested in this paper

    The recency ratio assessed by story recall is associated with cerebrospinal fluid levels of neurodegeneration biomarkers

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    Recency refers to the information learned at the end of a study list or task. Recency forgetting, as tracked by the ratio between recency recall in immediate and delayed conditions, i.e., the recency ratio (Rr), has been applied to list-learning tasks, demonstrating its efficacy in predicting cognitive decline, conversion to mild cognitive impairment (MCI), and cerebrospinal fluid (CSF) biomarkers of neurodegeneration. However, little is known as to whether Rr can be effectively applied to story recall tasks. To address this question, data were extracted from the database of the Alzheimer's Disease Research Center at the University of Wisconsin – Madison. A total of 212 participants were included in the study. CSF biomarkers were amyloid-beta (Aβ) 40 and 42, phosphorylated (p) and total (t) tau, neurofilament light (NFL), neurogranin (Ng), and α-synuclein (a-syn). Story Recall was measured with the Logical Memory Test (LMT). We carried out Bayesian regression analyses with Rr, and other LMT scores as predictors; and CSF biomarkers (including the Aβ42/40 and p-tau/Aβ42 ratios) as outcomes. Results showed that models including Rr consistently provided best fits with the data, with few exceptions. These findings demonstrate the applicability of Rr to story recall and its sensitivity to CSF biomarkers of neurodegeneration, and encourage its inclusion when evaluating risk of neurodegeneration with story recall

    Exercise has a positive impact on bone mineral density in seropositive human immunodeficiency virus: do health professionals know?

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    Introduction: Despite the concomitant negative effects of human immunodeficiency virus on bone mineral density in HIV-infected persons, studies on knowledge of effect of exercise on this health parameter in HIV population among health professionals seem unavailable. This study therefore examined knowledge on effect of exercise on BMD in HIV-infected persons among health professionals. Material and methods: This cross-sectional survey employed researcher designed, experts - validated questionnaire to enroll 434 respondents. The reliability coefficient “r” of the questionnaire was 0.75 with 92% response rate. Descriptive and inferential statistics were used to summarize and analyze the data respectively. The alpha value was set at 0.05. Results: Age range and mean age in years of the respondents were 21–59 and 35.88 ± 9.09 respectively; age group of 30–39 years predominated (45.3%). Males were in preponderance (52.4%), and most (74.4%) were married; while majority (54.7%) were nurses. Substantial proportion (54.2%) had less than good knowledge on the subject examined in this study. Significant difference (p 0.05). Conclusions: Knowledge on effect of exercise on BMD in HIV infected persons among health professionals was surprisingly below expectation, and therefore should be seen as a cause for concerned exercise scientists and public health experts
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