67 research outputs found
Adsorptive approach on nepholometric study of paint effluent using Tympanotonos fuscatus extract
Adsorptive study of paint effluent coagulation using T. fuscatus coagulant (TFC) is investigated. Effects of pH, dose, time, and temperature were investigated. Functional group, crystalline, morphology and thermal characteristics of samples were determined. Equilibrium data were analysed by Langmuir, Freundlich, Temkin, Frumkin, and Dubinin-Radushkevich (D-R) isotherms. Kinetic data were fitted to reversible first order, pseudo-first-order, pseudo-second-order, Elovich, intra-particle diffusion and Boyd kinetic models. Process Gibbs free energy (∆G°), enthalpy (∆H°) and the entropy (∆S°) were evaluated. The process was best described by Langmuir isotherm (R2 > 0.99; X2 ˂ 0.6; SSE ˂ 0.7). Pseudo second order best fitted the kinetic data. The process was spontaneous, feasible and endothermic. 97% optimal removal was achieved at pH 5. Tympanotonos fuscatus extract has potential for application as an effective coagulant while showing significant component of adsorptive phenomenon KEY WORDS: Paint effluent, Coagulation/flocculation, Adsorption, Tympanotonos fuscatus Bull. Chem. Soc. Ethiop. 2016, 30(3), 377-390.DOI: http://dx.doi.org/10.4314/bcse.v30i3.
On the relative merits of simple and advanced constitutive models in dynamic analysis of tunnels
A Review of Environmental Implications of Dredging Activities
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
African Communitarianism and Difference
There has been the recurrent suspicion that community, harmony, cohesion, and similar relational goods as understood in the African ethical tradition threaten to occlude difference. Often, it has been Western defenders of liberty who have raised the concern that these characteristically sub-Saharan values fail to account adequately for individuality, although some contemporary African thinkers have expressed the same concern. In this chapter, I provide a certain understanding of the sub-Saharan value of communal relationship and demonstrate that it entails a substantial allowance for difference. I aim to show that African thinkers need not appeal to, say, characteristically Euro-American values of authenticity or autonomy to make sense of why individuals should not be pressured to conform to a group’s norms regarding sex and gender. A key illustration involves homosexuality
The Intersectionality of Educational Inequalities and Child Poverty in Africa::A deconstruction
Ethical and legal implications of whole genome and whole exome sequencing in African populations
BACKGROUND: Rapid advances in high throughput genomic technologies and next generation sequencing are
making medical genomic research more readily accessible and affordable, including the sequencing of patient and
control whole genomes and exomes in order to elucidate genetic factors underlying disease. Over the next five
years, the Human Heredity and Health in Africa (H3Africa) Initiative, funded by the Wellcome Trust (United
Kingdom) and the National Institutes of Health (United States of America), will contribute greatly towards
sequencing of numerous African samples for biomedical research.
DISCUSSION: Funding agencies and journals often require submission of genomic data from research participants to
databases that allow open or controlled data access for all investigators. Access to such genotype-phenotype and
pedigree data, however, needs careful control in order to prevent identification of individuals or families. This is
particularly the case in Africa, where many researchers and their patients are inexperienced in the ethical issues
accompanying whole genome and exome research; and where an historical unidirectional flow of samples and
data out of Africa has created a sense of exploitation and distrust. In the current study, we analysed the
implications of the anticipated surge of next generation sequencing data in Africa and the subsequent data sharing
concepts on the protection of privacy of research subjects. We performed a retrospective analysis of the informed
consent process for the continent and the rest-of-the-world and examined relevant legislation, both current and
proposed. We investigated the following issues: (i) informed consent, including guidelines for performing
culturally-sensitive next generation sequencing research in Africa and availability of suitable informed consent
documents; (ii) data security and subject privacy whilst practicing data sharing; (iii) conveying the implications of
such concepts to research participants in resource limited settings.
SUMMARY: We conclude that, in order to meet the unique requirements of performing next generation
sequencing-related research in African populations, novel approaches to the informed consent process are required.
This will help to avoid infringement of privacy of individual subjects as well as to ensure that informed consent
adheres to acceptable data protection levels with regard to use and transfer of such information
Adsorptive study of coagulation treatment of paint wastewater using novel Brachystegia eurycoma extract
Abstract Adsorptive component of coagulation–flocculation of paint wastewater using Brachystegia eurycoma (seed) coagulant was investigated. The bio-sample was analyzed for functional groups, surface morphology and thermal characteristics. The effects of coagulant dosage, effluent pH and settling time on the process were studied. The coagulation data were analyzed in light of adsorption kinetics, isotherm and thermodynamics. Pseudo-second-order and Langmuir models best described the models, and the values recorded for Gibb’s free energy, entropy and enthalpy values were—28.692 kJ/mol, 0.206 kJ/mol and 34.857 kJ/mol, respectively. At the experimental condition, maximum process efficiency (96.50%) was obtained at coagulant dosage of 5 g/L, pH 8 and coagulation temperature of 35 °C. Having satisfactorily correlated coagulation data to adsorption models, it could be inferred that significant component of the process was predominated by adsorption
Chromotographic and wound healing studies of Jatropha curcas (Euphorbiacea)
The wound healing properties of the methanol extract of the leaves of Jatropha curcas were studied by incision and excision wound models in rats. The wound healing effect was compared to that of the standard antibiotic, Cicatrin R. The histopathological profile, phytochemistry and the acute toxicity were also studied. An attempt was made to resolve the extract into its components using thin layer chromatography (TLC). Result of the incision and excision wound model shows significant (P < 0.05) dose-dependent increase in wound contraction rate, skin breaking strength and decrease in epithelization period showing a healing potential comparable to that of Cicatrin powder at a dose of 200 mg/kg. Histopathological studies showed proliferation of epithelial tissue, angiogenesis and fibrosis due to treatment with Jatropha curcas. The prohealing action was due to increased collagen deposition as well as better alignment and maturation. The leaves of Jatropha curcas were found to contain alkaloids, glycosides, saponins, flavonoids, steroids, proteins, tannins, reducing sugars, fats and oils. The intraperitoneal acute toxicity test (LD50) of the extract in mice showed that it as relatively safe, since at a dose of 5000 mg/kg there was no death. Among chromatographic solvent systems tested, chloroform:ethylacetate (6:4) gave the best resolution of the extract giving the highest number of spots. The present study demonstrates wound healing potential of Jatropha curcasKeywords: wound healing, Jatropha curcas, angiogenesis, epithelization, proliferationJournal of Pharmaceutical and Allied Sciences, Vol. 7 No. 2 (2010
Fixation kinetics of chelated and non-chelated zinc in semi-arid alkaline soils: application to zinc management
This study was designed to examine the fixation pattern and kinetics of zinc
(Zn) in chelated (ethylenediaminetetraacetic acid, EDTA) and non-chelated
mixed micronutrient systems of semi-arid alkaline soils from the Southern High
Plains, USA. Soils were characterized for a suite of chemical and physical
properties and data obtained from extraction experiments fitted to various
kinetic models. About 30 % more plant-available Zn was fixed in the
non-chelated system within the first 14 days with only about 18 %
difference observed between the two systems by day 90, suggesting that the
effectiveness of the chelated compounds tended to decrease over time. The
strengths of the relationships of change in available Zn with respect to
other micronutrients (copper, iron, and manganese) were higher and more
significant in the non-chelated system (average <i>R</i><sup>2</sup> of 0.83), compared to
the chelated (average <i>R</i><sup>2</sup> of 0.42). Fixation of plant-available Zn was
best described by the power-function model (<i>R</i><sup>2</sup> = 0.94, SE  =  0.076) in
the non-chelated system, and was poorly described by all the models examined
in the chelated system. Reaction rate constants and relationships generated
from this study can serve as important tools for micronutrient management and
for future micronutrient modeling studies on these soils and other semi-arid
regions of the world
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