61 research outputs found
Effects of fluid flow on corrosion behaviour in pipe bends
Correlation on flow induced corrosion (FIC) for straight pipes and bends have been obtained by researchers via a two-dimensional numerical method and experimental techniques. However, for pipe bends, the correlations require further improvements as the flow in bends are more complicated. The objective of this research is to obtain more accurate correlations for FIC in bends using twodimensional and three-dimensional numerical and experimental techniques. In the numerical and experimental approach, several important parameters such as Reynolds number and selected discrete particle model (DPM) were used to obtain erosion rate for miter and smooth bend models. Validations for the modellings were compared with experimental results and locations of the eroded sections were observed to be in agreement. Then, the erosion rates were extracted and analyzed using shooting method. Finally, the new coefficients for the correlations were obtained. When the new equations were applied to the same two-dimensional models, it was shown that the previous two-dimensional models had over-predicted the mass transfer values. Furthermore, when comparisons were made between smooth and miter bends results under the same flow conditions, it was observed that mass transfer values calculated from miter bend models were much higher than that of smooth bends. Experimental results also showed similar behavior, when the surface morphology was examined under Field Emission Scanning Electron Microscope (FESEM). From numerical and experimental approach conducted, it is concluded that the inner diameter bends were the areas with the highest FIC behaviour for 300 and 450 smooth and mitre bends
Effect of flow pattern at pipe bends on corrosion behaviour of low carbon steek and its challenges
Recent design work regarding seawater flow lines has emphasized the need to identify, develop, and verify critical relationships between corrosion prediction and flow regime mechanisms at pipe bend. In practice this often reduces to an pragmatic interpretation of the effects of corrosion mechanisms at pipe bends. Most importantly the identification of positions or sites, within the internal surface contact areas where the maximum corrosion stimulus may be expected to occur, thereby allowing better understanding, mitigation, monitoring and corrosion control over the life cycle. Some case histories have been reviewed in this context, and the interaction between corrosion mechanisms and flow patterns closely determined, and in some cases correlated. Since the actual relationships are complex, it was determined that a risk based decision making process using selected ‘what’ if corrosion analyses linked to ‘what if’ flow assurance analyses was the best way forward. Using this in methodology, and pertinent field data exchange, it is postulated that significant improvements in corrosion prediction can be made. This paper outlines the approach used and shows how related corrosion modelling software data such as that available from corrosion models Norsok M5006, and Cassandra to parallel computational flow modelling in a targeted manner can generate very noteworthy results, and considerably more viable trends for corrosion control guidance. It is postulated that the normally associated lack of agreement between corrosion modelling and field experience, is more likely due to inadequate consideration of corrosion stimulating flow regime data, rather than limitations of the corrosion modelling. Applications of flow visualization studies as well as computations with the k-ε model of turbulence have identified flow features and regions where metal loss is a maximu
Acceptance and Rejection of Internet for Health Information Among Private Health Professionals in a Nigerian City
Internet is one technology that has permeated every sphere of human endeavour, including communication, science and technology, telecommunication, education and health among others. However, no matter how useful, fantastic, appealing and gratifying a technology is, not everyone accepts it. The study evaluates how medical professionals in private hospitals in Anyigba, Kogi State, Nigeria integrate the use of Internet into their professional practice. Conducted within the framework of Technology Acceptance Model (TAM), the study employed both quantitative and qualitative methods, using questionnaire and interview schedule respectively to identify factors that precipitate both acceptance and rejection of Internet. The study found that 53% of medical professionals in Anyigba prefer Internet sources as against 20% and 17% who prefer journal/books and professional colleagues respectively. The study also found that health professionals use the Internet mainly to get professional updates (Mean =4.02, Stand Deviation = 1.58, Variance = 2.51), communicate with patients (Mean = 3.94, Standard Deviation = 1.55, Variance = 2.41). Others notable uses identified are for drugs/medication (Mean = 3.77, Standard Deviation = 1.39, Variance = 1.94), monitor trends of diseases (Mean = 3.58, Standard Deviation = 1.75, Variance = 3.05) among other uses. Cost, relevance of information to professional practice, skills on how to use the technology and how readily accessible are the sources, are factors that influence acceptance and/or rejection of a possible information source. The study recommends that health professionals should promote capacity building for both younger and older practitioners on how best to employ Internet-based applications for medical practice. Keywords: Health communication, Internet, Technology Acceptance Model, Nigerian City, Private Hospita
Synthesis of fatty acid methyl ester (biodiesel) using environmentally benign catalyst (yam peel)
Homogeneous alkali-catalyzed transesterification is the typical process used in biodiesel production, complicating the downstream separation processes and causing oversupply of glycerol as by-product. In this work the synthesis of biodiesel by solid heterogeneous acid catalysts using sulphuric and phosphoric acids functionalized yam peel as catalysts and fried oil as the source of glyceride was investigated. The solid acid catalysts were prepared by carbonization followed by direct sulfonation and phosphoration via reflux. The FTIR Spectra of the catalyst and the XRD confirmed the incorporation of sulphate and phosphate groups on the carbonized yam peels. The amount of catalyst loading was investigated on the biodiesel yield. Sulphuric acid treated catalyst showed highest yield of 62.6 % at 1.0 g catalyst load, with phosphoric acid treated catalyst having slightly lower at 61.2 % and 1.0 g load. The physicochemical analysis of the used oil showed acid value of 27.50 mg KOH/g, free fatty acid (FFA) value of 13.83, density 0.91 g/mL, saponification value 154.28mgKOH/g. The presence of high free fatty acid in the oil feed indicate that the preferred catalyst to be used is heterogeneous catalyst
Dynamic modelling of microalgae cultivation process in high rate algal wastewater pond
In this work, a comprehensive dynamic mathematical modelling to simulate the production of microalgae in a high rate algal pond (HRAP) is attempted. A synergetic algal–bacterial system comprising various interrelated biological and chemical system processes is presented. The dynamic behaviour of HRAP system is studied by solving mass balance equations of different components which account light intensity and gas–liquid mass transfer. The model predictions are compared with the previously reported studies in the literature. The influence of kinetic and operating parameters, including the supply of CO2, the maximum growth rate, pond depth and dilution rates, on the pond performance are evaluated. The sensitivity analysis of important process parameters is also discussed in this study. The developed model, as a tool, can be used to assess the factors that affect the pond performance criteria, including algal productivity and the dynamics of nutrient requirements
Synthesis and study of the efficacies of Tetraaza macrocyclic ligand for the adsorption of heavy metals from wastewater
Condensation of Ethyl 2-methylacetoacetate and ethylenediamine yield 88.7% of Dimethyl-7,14-Diphenyl-1,4,8,11-Tetraazacyclotetradeca-4,7,11,14-Tetraene with a condense chemical formula as C18H32N4O2, and a molecular weight of 336.47. The complexes were prepared by the adsorption of heavy metals (Fe, Cu, Cd, Co and, Pb) from wastewater samples obtained from Kofar sauri, Lambun Dan Lawal and Youth craft village. The compounds were investigated by solubility, conductivity, melting/decomposition point, Atomic Absorption Spectroscopy, Infrared spectroscopy and Uv-visible spectroscopy. The Ligand 003 shows IR peak of υ(C=N) at 1633cm-1, and a shift was observed to a lower peak as a result of adsorption of the heavy metals by the ligand, which is signifying the formation of the complexes. AAS results indicates high concentration of Cu in each case when compared, the rest of the metals varying at different level of concentration in the compounds. Cu may best fit the center of the ligand cavity having a concentration beyond computing with the rest of the metals.Key words: Schiff base, wastewater, heavy metal
Applying Contingent Valuation Method for Economic Valuation of Awqaf Wealth Management in Welfare Changes of Muslim Households In
Objective- The main objective of this study is to estimate the Willingness to Pay of the Muslim households to contribute cash waqf as a strategy towards wealth management in Sri Lanka. Waqf is holding or confinement which is emphasised in Islam as ibadah as it can distribute the wealth among the Muslim society and would help to develop the Islamic vision of brotherhood.Method- Contingent valuation method is used to estimate the Willingness to Pay of Muslim households to improve socio-economic status of the low income people through waqf wealth management in Sri Lanka. This study is developed based on Random Utility Theory.Result- This paper identifies the appropriate methods to estimate the willingness to pay of Muslim households in Sri Lanka for waqf (awqaf is plural) institutions. Such evaluations are crucial for the Islamic financial system to function effectively in order to achieve the dignified objectives of socio-economic justice through proper distribution of wealth.Conclusion-This paper presents a conceptual model of waqf institutions which would be useful for further empirical research in this area. The findings are not only appropriate and applicable to Sri Lanka but also to other Muslim and non-Muslim countries. This is a unique contribution to the Islamic economic literature. The knowledge obtained from this study hopes to propose cash waqf to manage the wealth in order to improve the socio-economic status of low income people in Sri Lanka.Tujuan - Tujuan utama dari penelitian ini adalah untuk memperkirakan Kemauan Membayar rumah tangga Muslim untuk berkontribusi wakaf tunai sebagai strategi menuju pengelolaan kekayaan di Sri Lanka. Wakaf secara bahasa menahan (harta) yang ditekankan dalam Islam sebagai ibadah karena dapat mendistribusikan kekayaan di antara masyarakat Muslim dan akan membantu untuk mengembangkan visi Islam yaitu persaudaraan.Metode - Metode penilaian Kontingensi digunakan untuk memperkirakan Kesediaan membayar rumah tangga Muslim dalam meningkatkan status sosial - ekonomi masyarakat berpenghasilan rendah melalui pengelolaan kekayaan wakaf di Sri Lanka. Penelitian ini dikembangkan berdasarkan Teori Utilitas Acak.Hasil - Paper ini mengidentifikasi metode yang tepat untuk memperkirakan kemauan membayar rumah tangga Muslim di Sri Lanka untuk wakaf lembaga. Evaluasi tersebut sangat penting untuksistem keuangan Islam yang berfungsi secara efektif dalam rangka mencapai tujuan yang bermartabat keadilan sosial - ekonomi melalui distribusi kekayaan yang tepat.Kesimpulan - Paper ini menyajikan model konseptual lembaga wakaf yang akan berguna untuk penelitian empiris lebih lanjut di daerah ini. Temuan ini tidak hanya tepat dan berlaku untuk Sri Lanka, tetapi juga ke negara-negara Muslim dan non -Muslim lainnya. Ini adalah kontribusi yang unik untuk literatur ekonomi Islam. Pengetahuan yang diperoleh dari studi ini adalah mengharapkan agar wakaf tunai diusulkan untuk mengelola kekayaan dalam rangka meningkatkan status sosial - ekonomi masyarakat berpenghasilan rendah di Sri Lanka
Life cycle optimization for sustainable algal biofuel production using integrated nutrient recycling technology
In this study, a multi-objective optimization of sustainable integration of algal biofuel production using nutrient recycling technology, such as anaerobic digestion and hydrothermal liquefaction, is considered. Gross annual profitability and global warming potential (GWP) are the criteria chosen for the design of the algal biofuel production system. Three scenarios, such as full-scale (baseline), pilot-scale (conservative), and lab-scale (nominal), are chosen based on the expected maturity levels and nutrient demand. The results of the optimization produce Pareto sets of optimal solutions for acknowledging the trade-off between the economic and the environmental criteria of the integrated system. It is found that the anaerobic digestion (AD) technology shows better performance in terms of an environmental perspective, displacing the excessive fertilizer requirements due to its maturity in comparison with the hydrothermal liquefaction (HTL) process. However, HTL is a new, evolving, promising nutrient recycling technology which demonstrates economic preferences compared to the AD process due to its low cost of production
Design and optimizing of geometric for solar updraft tower using computational fluid dynamics (CFD)
There are many experimental and analytical approaches that have been physically proven in the last few decades for the Solar Updraft Tower (SUT) concept to provide energy from solar radiation. Solar chimneys with their potential advantages have gained more attention by fully utilising solar radiation energy to generate air movement by stack pressure. This movement is driving the heated air through the chimney channel and then drawing colder air through the building in a continuous cycle. A parametric study on the geometry of the solar updraft tower is carried out with a different slope angle of collector, different inlet height of collector and different diameter of chimney collector inlet height with fixed solar radiation at 800 W/m2. A validated model is compared with the experimental prototype constructed by the University of Zanjan, Iran. The result shows an incredible improvement in the power generated by a collector with 0 degree and the best entrance gap of collector and chimney diameter at 0.05 m and 0.05 m respectively. The findings and results are discussed and suggested for future works
Synthesis and evaluation of the efficacies of some Schiff bases for the removal of heavy metals from wastewater
The Schiff bases, 2-aminoethyl-1,3-diphenyl-3-((2-(piperazin-1- ylethyl) imino) propylidene)-propylethane-1,2-diamine with 89% yield, and 2,2-ethylideneamino)ethyl)phenol-2,2- hydroxybenzalidene) ethyl)acetimedate salt with 91% yield, represented as L1 and L2 respectively were synthesized and characterized. Their metal ion removal competences for five heavy metals (Cu, Fe, Co, Cd and Pb) was investigated, in three categories of wastewater obtained from Lambun Dan Lawal (LDL), Kofar sauri (K/sauri) and Youth Craft Village (YCV). The Schiff bases were characterized before and after complexation, by spectroscopic techniques such as Infrared spectroscopy, Molar conductance, UV-Visible, Melting and Decomposition temperature and solubility test. The concentration of the heavy metals both in the wastewater and the complexes was determined by Atomic Absorption Spectroscopy (AAS). The Schiff bases shows outstanding character, by adsorbing/removing most of the targeted heavy metals at variable concentration, especially copper which shows the highest concentration. The results suggested that, the two Schiff bases can be used as an alternative chelating agents, for the removal of heavy metals from wastewater.Keywords: Schiff base, Wastewater, Heavy metals, Evaluation, Extractio
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