2,039,978 research outputs found

    Rauvolfia vormitoria Effect on the Degradation of Aluminium Alloy in 2.5 M Hydrochloric Acid Solution

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    The deterioration of aluminium alloy in 2.5 M hydrochloric acid in the presence Rauvolfia vormitoria extract was examined using both gasometric and gravimetric techniques. Aluminium coupons measuring 4 cm by 1 cm were introduced into test solutions of uninhibited acid and also those containing extract quantities of 10, 20, 30 and 40 cm3 at ambient temperature of 250C for a total cumulative period of 117 minutes. The volumes of hydrogen gas evolved and weight loss readings were recorded and analyzed to obtain weight loss and corrosion rate for each coupon at specific time intervals. The results however, showed that while extract quantity was increasing; weight loss measurements increased but inhibitor efficiency decreased. Also, the metal surface-phytoconstituent interaction mechanism was consistent with the Temkin adsorption isotherm and the 3 minutes curve showed the best exposure time for phytochemicals to adsorb to alloy surface. Furthermore, microstructural studies showed an indirect relationship between metallic degradation and extract quantity, while uniformity of the irregular intermetallic phases increased with increasing extract quantity

    Development of Wearable Systems for Ubiquitous Healthcare Service Provisioning

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    This paper reports on the development of a wearable system using wireless biomedical sensors for ubiquitous healthcare service provisioning. The prototype system is developed to address current healthcare challenges such as increasing cost of services, inability to access diverse services, low quality services and increasing population of elderly as experienced globally. The biomedical sensors proactively collect physiological data of remote patients to recommend diagnostic services. The prototype system is designed to monitor oxygen saturation level (SpO2), Heart Rate (HR), activity and location of the elderly. Physiological data collected are uploaded to a Health Server (HS) via GPRS/Internet for analysis.Comment: 6 pages, 3 figures, APCBEE Procedia 7, 2013. arXiv admin note: substantial text overlap with arXiv:1309.154

    Adsorption Behaviour of [(4-Hydroxy-6-methyl-2-oxo-2Hpyran- 3-yl)-(4-methoxy-phenyl)-1methyl]-urea on Stainless Steel in Phosphoric Media

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    The adsorption of [(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-(4-methoxy-phenyl)- methyl]-urea on iron in phosphoric media was studied by using electrochemical technique. The adsorption mechanism was investigated using adsorption isotherms. The experimental data fit localized adsorption models. The values for free energy of adsorption, o DGads , were also calculated at each surface coverage, �, of the studied compound by applying the mathematical model of Bockris – Swinkels adsorption isotherm. The variation of free energy of adsorption o ads DG with surface coverage, �, was interpreted in terms of deviation from ideal condition assumed in Langmuir model. A possible adsorption model of HPU2 molecules on to the metal surface was suggested

    Comparative study of microwave assisted and conventional synthesis of novel 2-quinoxalinone-3- hydrazone derivatives and its spectroscopic properties

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    A series of novel quinoxalin-2(1H)-one-3-hydrazone derivatives, 2a - 8d were synthesized via condensation of 3-hydrazinoquinoxalin-2(1H)-one, 1, with the corresponding ketones under microwave irradiation. The microwave assisted reaction was remarkably successful and gave hydrazones in higher yield at less reaction time compared to conventional heating method. The chemical structures of the compounds prepared were confirmed by analytical and spectral dat

    Acid Failure of Mild Steel in 2 M Sulphuric Acid in the Presence of Vernonia amygdalina

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    The degradation of mild steel in 2 M sulphuric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Mild steel coupons of dimension 4 cm by 1.5 cm were immersed in test solutions of uninhibited acid and also those containing extract concentrations of 60,100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the reaction were recorded and examined. The results showed that while extract concentration was increasing, H2 evolution and % I.E increased, with a reduction in corrosion rate. The reduction in corrosion rate was observed to follow in order of increasing extract concentration. Also, phytoconstituent-metal interaction mechanism was best explained by Freundlich isotherm, with the 4 minutes curve becoming the best contact time for the extract phytochemicals to properly adsorb to metal surface across all concentrations used. Furthermore, an expression suitable for estimating corrosion rate values once concentration is known was also obtained. The microstructural studies however, revealed that increasing the extract concentration led to considerable reduction in the dominant coarsening of the oxide of iron phase, while the pearlite and ferrite phases were highly dispersed

    Environment Induced Failure of Mild Steel in 2 M Sulphuric Acid Using Chromolaena odorata

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    Failure investigation of mild steel sample in 2 M sulphuric acid solution in the presence of Chromolaena odorata extract was conducted using the gasometric method. Mild steel coupons, each measuring 4 cm by 1.5 cm were completely immersed in test solutions of free acid and also those containing extract quantities of 60, 100 and 140 cm3 at a temperature of 333K for 60 minutes. The volumes of hydrogen gas evolved from the experiment were recorded and analyzed. The result showed that maximum inhibitor efficiency which has a relationship with lowest corrosion rate was obtained at the highest inhibitor concentration of 140 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volume. Temkin isotherm best described the metal surface interaction adsorption mechanism. Once concentration of the acid is known, an expression for estimating corrosion rate values in the presence of the extract was obtained. Also, the photomicrograph study showed a direct relationship between the extract quantity and the extent of corrosion. Sample immersed in the 140 cm3 extract quantity showed no trace of the third phase but rather the presence of a finely distributed pearlite phase indicating that increased inhibitor concentration led to a reduction in the deterioration of the metal

    Ophthalmic disorders among students of School for the Deaf

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    Aim: This study aimed at determining the prevalence and pattern of ophthalmic disorders amongstudents of School for the Deaf, Akure, Ondo State, Nigeria.Methodology: This is a cross sectional descriptive study was conducted in October, 2011 aspart of activities marking the Annual Physicians’ week of Nigerian Medical Association (NMA),Ondo State. Ethical clearance was obtained from the Ethical Review Committee of FederalMedical Centre, Owo prior to commencement of this study. The permission of the SchoolAuthority was also obtained before the commencement of this study. The respondents wereselected by simple random sampling technique. All enrolled participants were interviewed withthe aid of the study instrument (questionnaire) by the authors and interpreters (school teachers).Results: The respondents comprised of 91(56.9%) Males and 69 Females (43.1%). Nearly all therespondents;158(98.8%) were deaf and dumb. Most respondents; 116(72.5%) had ocularexamination in the past. Few respondents; 118(73.75%) had ophthalmic disorder. The commonest ophthalmic disorder was refractive error which was found in 16 respondents(38.1%). Myopia was diagnosed in 9 respondents.CONCLUSION: Most of the respondents were deaf and dumb. Few respondents hadophthalmic disorder. The commonest ophthalmic disorder was refractive error. Myopia was themost predominant refractive error. There is need for periodic ocular screening and treatment atthe School for the Deaf.

    Resource and cost management

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    Educational lecture notes contains the fundamentals of a general theory of resource and cost management, classification of costs for decision-making, methods of constructing cost functions of the enterprise, analysis of the relationship between costs, volume and profits, the methods and systems of cost calculation, principles of cost management system. Designed for students directions 073 «Management» and 076 «Entrepreneurship, trade and exchange activity»

    HISTOLOGICAL STUDIES OF BREWERY SPENT GRAINS IN DIETARY PROTEIN FORMULATION IN DONRYU RATS

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    The increasing production of large tonnage of products in brewing industries continually generates lots of solid waste which includes spent grains, surplus yeast, malt sprout and cullet. The disposal of spent grains is often a problem and poses major health and environmental challenges, thereby making it imminently necessary to explore alternatives for its management. This paper focuses on investigating the effects of Brewery Spent Grain formulated diet on haematological, biochemical, histological and growth performance of Donryu rats. The rats were allocated into six dietary treatment groups and fed on a short-term study with diet containing graded levels of spent grains from 0, 3, 6, 9, 12 and 100% weight/weight. The outcome demonstrated that formulated diet had a positive effect on the growth performance of the rats up to levels of 6% inclusions, while the haematological and biochemical evaluation revealed that threshold limit should not exceed 9% of the grain. However, the histological study on the liver indicated a limit of 3% inclusion in feed without serious adverse effect. Thus invariably showing that blend between ranges 1-3% is appropriate for the utilization of the waste in human food without adverse effect on the liver organ. The economic advantage accruing from this waste conversion process not only solves problem of waste disposal but also handle issues of malnutrition in feeding ration
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