Search results for: corrosive medium

Authors: Jeffrey Chang, Barun Dasgupta

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E-business technologies, whereby business transactions are conducted remotely using the Internet, present unique opportunities and challenges for business. E-business technologies are applicable to a wide range of organizations and small and medium-sized enterprises (SMEs) are no exception. There is an established body of literature about e-business, looking at definitions, concepts, benefits and challenges. In general, however, the research focus has been on larger organizations, not SMEs. In an attempt to redress the balance of research, this paper looks at e-business technologies specifically from a small business perspective. It seeks to identify the possible barriers that SMEs might face when considering adoption of the e-business concept and practice as part of their business process change initiatives and implementation. To facilitate analysis of these barriers a conceptual framework has been developed which outlines the key conceptual and practical challenges of e-business implementation in SMEs. This is developed following a literature survey comprised of three categories: characteristics of SMEs, issues of IS/IT use in SMEs and general e-business adoption and implementation issues. The framework is then empirically assessed against 7 SMEs who have yet to implement e-business or whose e-business efforts have been unsatisfactory. Conclusions from the case studies can be used to verify the framework, and set parameters for further larger scale empirical investigation.

Keywords: business process change, disruptive technologies, electronic business (e-Business), electronic commerce (e-Commerce), ICT adoption, small and medium sized enterprises (SMEs)

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Authors: Chand Pasha, Yasser Turki Alharbi, Krasamira Stancheva

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A simple spectrophotometric method for the determination of folic acid in pharmaceutical dosage samples was developed. The method is based on the diazotization reaction of thiourea with sodium nitrite in acidic medium yields diazonium compounds, which is then coupled with folic acid in basic medium yields yellow coloured azo dyes. Beer’s Lamberts law is observed in the range 0.5 – 16.2 μgmL-1 at a maximum wavelength of 416nm. The molar absorbtivity, sandells sensitivity, linear regression equation and detection limit and quantitation limit were found to be 5.695×104 L mol-1cm-1, 7.752×10-3 g cm-2, y= 0.092x - 0.018, 0.687 g mL-1 and 2.083 g mL-1. This method successfully determined Folate in Pharmaceutical formulations.

Keywords: folic acid determination, spectrophotometry, diazotization, thiourea, pharmaceutical dosage samples

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Authors: Laidi Babouri

Abstract:

The remarkable properties of steel, such as hardness and impact resistance, motivate their use in the automotive manufacturing industry. However, due to the very vulnerable environmental conditions of use, the steel that makes up the car body can corrode. This situation is motivating more and more automobile manufacturers to develop research to develop processes minimizing the rate of degradation of the physicomechanical properties of these materials. The present work falls within this perspective; it presents the results of a research study focused on the use of synthetic wax for the protection of steel, type XES (DC04), against corrosion in aggressive environments. The media used in this study are an acid medium with a pH=5.6, a 3% chloride medium, and a dry medium. Evaluation of the protective power of synthetic wax in different environments was carried out using mass loss techniques (immersion), completed by electrochemical techniques (stationary and transient). The results of the immersion of the steel samples, with a surface area of (1.44 cm²), in the various media, for a period of 30 days, using the immersion technique, showed high protective efficiency of synthetic wax in acidic and saline environments, with a lesser degree in a dry environment. Moreover, the study of the protective power, using electrochemical techniques, confirmed the results obtained in static mode (loss of mass), the protective efficiency of synthetic wax, against the corrosion of steel, in different environments, which reaches a maximum rate of 99.87% in a saline environment.

Keywords: corrosion, steel, industrial wax, environment, mass loss, electrochemical techniques

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Authors: Igho Ekiugbo, Christos Papanagnou

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The energy sector continues to face increased scrutiny due to climate change challenges emanating from the burning of fossil fuels, such as coal, oil, and gas. These climate change challenges have motivated industry practitioners and researchers alike to gain an interest in the way businesses operate. This paper aimed to investigate and assess how small and medium-sized enterprises (SMEs) are reducing the impact of their operations, especially those within their supply chains, by assessing the sustainability practices they have adopted and implemented as well as the benefits and challenges of adopting such practices. Data will be collected from SMEs operating across the downstream oil and gas sector in Nigeria using questionnaire surveys. To analyse the data, confirmatory factor analysis and regression analysis will be performed. This method is deemed more suitable and appropriate for testing predefined measurements of sustainable supply chain practices as contained in the extant literature. Preliminary observations indicate a consensus on the awareness of the sustainability concept amongst the target participants. To the best of our knowledge, this paper is among the first to investigate the sustainability practices of SMEs operating in the Nigerian oil and gas sector and will therefore contribute to the sustainability and circular economic literature.

Keywords: small and medium-sized enterprises, sustainability practices, supply chains, sustainable supply chain management, corporate sustainability, oil and gas, business performance

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Authors: Anwaar O. Ali, Mahmoud Fathy Mubarak, Mahmoud Ibrahim Abdou, Hector Cano Esteban, Amany A. Aboulrous

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Corrosion resistance and lubrication are crucial characteristics required for geothermal drilling fluids. In this study, a ZnO/Fe₂O₃ nanocomposite was fabricated and incorporated into the structure of Cetyltrimethylammonium bromide (CTAB). Several physicochemical techniques were utilized to analyze and describe the synthesized nanomaterials. The surface morphology of the composite was assessed through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX). The corrosion inhibition capabilities of these materials were explored across various corrosive environments. The weight loss and electrochemical methods were utilized to determine the corrosion inhibition activity of the prepared nanomaterials. The results demonstrate a high level of protection achieved by the composite. Additionally, the lubricant coefficient and extreme pressure properties were evaluated.

Keywords: nanofluid, corrosion, geothermal drilling fluids, ZnO/Fe2O3

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Authors: Salman Abdulrasaq

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Small and Medium Enterprises (SMEs) has been considered as indices for economic development in a country economy. The development of entrepreneurship skills is therefore necessary. This study, seeks to examine the impact of Entrepreneurship on the Growth of Small Businesses Kwara State, Nigeria. The data used were primarily obtained from the questionnaire administered to the randomly selected areas in the state. Regression statistical tool was employed with aid of SPSS to test the validity of the hypothesis formulated in the study. The study therefore concludes that; the qualities of entrepreneur have impact the growth of Small Businesses s in the selected areas of the state. In view of this, the study recommends that; entrepreneurship development would serve as a tool for the growth of small business enterprises.

Keywords: entrepreneurship, growth, development, Nigeria

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Authors: A. Tavangari, N. Salehzadeh

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In the crack growth analysis, the Stress Intensity Factor (SIF) is a fundamental prerequisite. In the present study, the mode I stress intensity factor (SIF) of three-dimensional penny-Shaped crack is obtained in an isotropic elastic cylindrical medium with arbitrary dimensions under arbitrary loading at the top of the cylinder, by the semi-analytical method based on the Rayleigh-Ritz method. This method that is based on minimizing the potential energy amount of the whole of the system, gives a very close results to the previous studies. Defining the displacements (elastic fields) by hypothetical functions in a defined coordinate system is the base of this research. So for creating the singularity conditions at the tip of the crack the appropriate terms should be found.

Keywords: penny-shaped crack, stress intensity factor, fracture mechanics, Ritz method

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Authors: Naveed Ejaz, Liaqat Ali, Amer Nusair

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Thermal barrier coatings (TBCs) serve as thermal barriers against the high temperature of the hot regions of the aircraft turbine engines keeping the surface of the turbine blades, vanes and combustion chamber at comparatively lower temperature. The life of these coatings depends on many in-service environmental factors. Among these factors, the behavior of the bond coat as well as the top coat at high temperature aggravated by the corrosive environments having S, V, Na and Cl plays a key role. The incorporation of the 5-15% CaZrO3 in YSZ coatings was studied after hot corrosion in vanadium oxide environment. It was observed that the reactivity of the V gradually switched from Y to Ca making CaV2O4 instead of YVO4; the percentage of CaV2O4 increased with the increase of CaZrO3 in YSZ. It eventually prevented leaching out of the Y from YSZ leaving the YSZ without any harmful phase change. The thermal insulation was found to be improved in case of CaZrO3 incorporated YSZ coatings as compared to only YSZ coating.

Keywords: hot corrosion, thermal barrier coatings, yttria stabilized zirconia, calcium zirconate

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Authors: A. Mourtzikou, D. Sygkridou, T. Georgakopoulos, G. Katsagounos, E. Stathatos

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Over 60% highly transparent quasi-solid-state dye-sensitized solar cells (DSSCs) with dimension of 50x50 cm² were fabricated via inkjet printing process using nanocomposite inks as raw materials and tested under outdoor illumination conditions. The cells were electrically characterized, and their possible application to the shell of greenhouses was also examined. The panel design was in Z-interconnection, where the working electrode was inkjet printed on one conductive glass and the counter electrode on a second glass in a sandwich configuration. Silver current collective fingers were printed on the glasses to make the internal electrical connections. In that case, the adjacent cells were connected in series via silver fingers and finally insulated using a UV curing resin to protect them from the corrosive (I^-/I₃^-) redox couple of the electrolyte.

Keywords: Dye-sensitized solar panels, inkjet printing, quasi-solid state electrolyte, semi-transparency, scale up

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Authors: Salah Hamri, Tewfik Bouchaour, Ulrich Maschke

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The aim of this works is the study of swelling ratio of cross-linked polymer networks poly (2-hydroxyethyl methacrylate) (PHEMA). The system composed of erythrosine and Triethanolamine, in aqueous medium, is used as photo-initiator and 1,6-Hexanediol diacrylate as cross-linker. The analysis of UV-visible and infrared spectra, which were taken at different times during polymerization/cross linking, makes it possible to obtain useful information on the reaction mechanism. The swelling behavior was study by changing the nature of solvent, dye sensitizer (erythrosine, rose Bengal and eosin), and pH of the medium. The exploitation of experimental results using Fick diffusion model is also expected and shows a good correlation between theoretical and experimental results.

Keywords: cross-linker, photo-sensitizer, polymer network, swelling ratio

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Authors: Mohd Azraei Pangah Pa'at, Mohd Ruzlin Mohd Mokhtar, Norhidayu Rameli, Tashia Marie Anthony, Huzainie Shafi Abd Halim

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Partial Discharge (PD) diagnostic mapping testing is one of the main diagnostic testing techniques that are widely used in the field or onsite testing for underground power cable in medium voltage level. The existence of PD activities is an early indication of insulation weakness hence early detection of PD activities can be determined and provides an initial prediction on the condition of the cable. To effectively manage the results of PD Mapping test, it is important to have acceptable criteria to facilitate prioritization of mitigation action. Tenaga Nasional Berhad (TNB) through Distribution Network (DN) division have developed PD severity model name Severity Index (SI) for offline PD mapping test since 2007 based on onsite test experience. However, this severity index recommendation action had never been revised since its establishment. At presence, PD measurements data have been extensively increased, hence the severity level indication and the effectiveness of the recommendation actions can be analyzed and verified again. Based on the new revision, the recommended action to be taken will be able to reflect the actual defect condition. Hence, will be accurately prioritizing preventive action plan and minimizing maintenance expenditure.

Keywords: partial discharge, severity index, diagnostic testing, medium voltage, power cable

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Authors: Murat Oral, Seda Bostancı, Sadık Ata, Kevser Dincer

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When evaluating the aesthetics of cities, an analysis of the urban form development depending on design properties with a variety of factors is performed together with a study of the effects of this appearance on human beings. Different methods are used while making an aesthetical evaluation related to a city. Entropy, in its preliminary meaning, is the mathematical representation of thermodynamic results. Measuring the entropy is related to the distribution of positional figures of a message or information from the probabilities standpoint. In this study, analysis of evaluation the urban skylines by the entropy approach was modelled with Rule-Based Mamdani-Type Fuzzy (RBMTF) modelling technique. Input-output parameters were described by RBMTF if-then rules. Numerical parameters of input and output variables were fuzzificated as linguistic variables: Very Very Low (L1), Very Low (L2), Low (L3), Negative Medium (L4), Medium (L5), Positive Medium (L6), High (L7), Very High (L8) and Very Very High (L9) linguistic classes. The comparison between application data and RBMTF is done by using absolute fraction of variance (R2). The actual values and RBMTF results indicated that RBMTF can be successfully used for the analysis of evaluation the urban skylines by the entropy approach. As a result, RBMTF model has shown satisfying relation with experimental results, which suggests an alternative method to evaluation of the urban skylines by the entropy approach.

Keywords: urban skylines, entropy, rule-based Mamdani type, fuzzy logic

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Authors: Mark Kaahwa, Chang Zhu, Moses Muhumuza

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This study investigates the satisfaction of distance education university students (DEUS) with the use of audio media as a medium of instruction. Studying students’ satisfaction is vital because it shows whether learners are comfortable with a certain instructional strategy or not. Although previous studies have investigated the use of audio media, the satisfaction of students with an instructional strategy that combines radio teaching and podcasts as an independent teaching strategy has not been fully investigated. In this study, all lectures were delivered through the radio and students had no direct contact with their instructors. No modules or any other material in form of text were given to the students. They instead, revised the taught content by listening to podcasts saved on their mobile electronic gadgets. Prior to data collection, DEUS received orientation through workshops on how to use audio media in distance education. To achieve objectives of the study, a survey, naturalistic observations and face-to-face interviews were used to collect data from a sample of 211 undergraduate and graduate students. Findings indicate that there was no statistically significant difference in the levels of satisfaction between male and female students. The results from post hoc analysis show that there is a statistically significant difference in the levels of satisfaction regarding the use of audio media between diploma and graduate students. Diploma students are more satisfied compared to their graduate counterparts. T-test results reveal that there was no statistically significant difference in the general satisfaction with audio media between rural and urban-based students. And ANOVA results indicate that there is no statistically significant difference in the levels of satisfaction with the use of audio media across age groups. Furthermore, results from observations and interviews reveal that DEUS found learning using audio media a pleasurable medium of instruction. This is an indication that audio media can be considered as an instructional strategy on its own merit.

Keywords: audio media, distance education, distance education university students, medium of instruction, satisfaction

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Authors: Ghazanfar Bozai, Kanwal Gul

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In Pakistan, SMEs are the major source of contribution to the economy, but due to lack of proper HR practices (lack of employee engagement), these fast growing business shut down with in few years of startup. The purpose of this study is to conduct a comprehensive literature survy of the major best practices used for employee engagement globally. This paper could be used as employee engagement best practices guide for SME’s in developing countries. This article is focused on identifying the attributes of employee engagement in different countries/ cultures and organizations. It will provide a summary of employee engagement models used globally and how SMEs could pick suitable attributes of employee engagement as per their structural culture. This article will add valuable literature on employee engagement in developing countries for new startups and small, medium business.

Keywords: attributes, employee engagement, human resources practices, small medium enterprises

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Authors: Alok Kumar Kamal, Vinod Kumar

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The trench gate MOSFET has shown itself as the most appropriate power device for low to medium voltage power applications due to its lowest possible ON resistance among all power semiconductor devices. In this research work a double-epilayer PSGT structure using a thin layer of N+ polysilicon as gate material. The total ON-state resistance (RON) of UMOSFET can be reduced by optimizing the epilayer thickness. The optimized structure of Double-Epilayer exhibits a 25.8% reduction in the ON-state resistance at Vgs=5V and improving the switching characteristics by reducing the Reverse transfer capacitance (Cgd) by 7.4%.

Keywords: Miller-capacitance, double-Epilayer;switching characteristics, power trench MOSFET (U-MOSFET), on-state resistance, blocking voltage

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Authors: H. Sakamoto, J. Tochimoto, S. Kurosawa, M. Suzuki, S. Oguri

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Salt stress adversely affects plant growth at various stages of development including seed germination, seedling establishment, vegetative growth and finally reproduction. Because of their immobile nature, plants have evolved mechanisms to sense and respond to salt stress. Seed dormancy is an adaptive trait that enables seed germination to coincide with favorable environmental conditions. We identified a novel locus of Arabidopsis, designated SHG1 (salt hypersensitive germination 1), whose disruption leads to reduced germination rate under moderate salt stress conditions. SHG1 encodes a transmembrane protein with an ankyrin repeat motif that has been implicated in diverse cellular processes such as signal transduction. The SGH1-disrupted Arabidopsis mutant died at the cotyledon stage when sown on salt-containing medium, although wild type plants could form true leaves under the same conditions. On the other hand, this mutant showed similar phenotypes to wild type plants when sown on medium without salt and transferred to salt-containing medium at the vegetative stage. These results suggested that SHG1 played indispensable role in the seed germination and seedling establishment under moderate salt stress conditions. SHG1 may be involved in the release of seed dormancy.

Keywords: germination, ankyrin repeat, arabidopsis, salt tolerance

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Authors: Reza Hosseinpourpia, Stergios Adamopoulos, Carsten Mai

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Medium density fiberboard (MDF) is a common category of wood-based panels that are widely used in the furniture industry. Fine lignocellulosic fibres are combined with a synthetic resin, mostly urea formaldehyde (UF), and joined together under heat and pressure to form panels. Like solid wood, MDF is a hygroscopic material; therefore, its moisture content depends on the surrounding relative humidity and temperature. In addition, UF is a hydrophilic resin and susceptible to hydrolysis under certain conditions of elevated temperatures and humidity, which cause dimensional instability of the panels. The latter directly affect the performance of final products such as furniture, when they are used in situations of high relative humidity. Existing water-repellent formulations, such as paraffin, present limitations related to their non-renewable nature, cost and highest allowed added amount. Therefore, the aim of the present study was to test the suitability of renewable water repellents as alternative chemicals for enhancing the dimensional stability of MDF panels. A small amount of tall oil based formulations were used as water-repellent agents in the manufacturing of laboratory scale MDF. The effects on dimensional stability, internal bond strength and formaldehyde release of MDF were tested. The results indicated a good potential of tall oil as a bio-based substance of water repellent formulations for improving the dimensional stability of MDF.

Keywords: dimensional stability, medium density fiberboard, tall oil, urea formaldehyde

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Authors: Soner Cubuk, Mirgul Kosif, M. Vezir Kahraman, Ece Kok Yetimoglu

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Boron is an essential trace element for the completion of the life circle for organisms. Suitable methods for the determination of boron have been proposed, including acid - base titrimetric, inductively coupled plasma emission spectroscopy flame atomic absorption and spectrophotometric. However, the above methods have some disadvantages such as long analysis times, requirement of corrosive media such as concentrated sulphuric acid and multi-step sample preparation requirements and time-consuming procedures. In this study, a selective and reusable fluorescent sensor for boron based on glycosyloxyethyl methacrylate was prepared by photopolymerization. The response characteristics such as response time, pH, linear range, limit of detection were systematically investigated. The excitation/emission maxima of the membrane were at 378/423 nm, respectively. The approximate response time was measured as 50 sec. In addition, sensor had a very low limit of detection which was 0.3 ppb. The sensor was successfully used for the determination of boron in water samples with satisfactory results.

Keywords: boron, fluorescence, photopolymerization, polymeric sensor

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Authors: Muhammad Aasim, Mehmet Karataş, Fatih Erci, Şeyma Bakırcı, Ecenur Korkmaz, Burak Kahveci

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Water hyssop (Bacopa monnieri L. Wettst.) is an important medicinal aquatic/semi aquatic plant native to India where it is used in traditional medicinal system. The plant contains bioactive compounds mainly Bacosides which are the main ingridient of commercial drug available as memory enhancer tonic. The local name of water hyssop is Brahmi and brahmi based drugs are available against for curing chronic diseases and disorders Alzheimer’s disease, anxiety, asthma, cancer, mental illness, respiratory ailments, and stomach ulcers. The plant is not a cultivated plant and collection of plant from nature make palnt threatened to endangered. On the other hand, low seed viability and availability make it difficult to propagate plant through traditional techniques. In recent years, plant tissue culture techniques have been employed to propagate plant for its conservation and production for continuous availability of secondary metabolites. On the other hand, application of nanoparticles has been reported for increasing biomass, in vitro regeneration and secondary metabolites production. In this study, silver nanoparticles (AgNPs) were applied at the rate of 2, 4, 6, 8 and 10 ppm to Murashihe and Skoog (MS) medium supplemented with 1.0 mg/l Benzylaminopurine (BAP), 3.0% sucrose and 0.7% agar. Leaf explants of water hyssop were cultured on AgNPs containing medium. Shoot induction from leaf explants were relatively slow compared to medium without AgNPs. Multiple shoot induction was recorded after 3-4 weeks of culture comapred to control that occured within 10 days. Regenerated shoots were rooted successfully on MS medium supplemented with 1.0 mg/l IBA and acclimatized in the aquariums for further studies.

Keywords: Water hyssop, Silver nanoparticles, In vitro, Regeneration, Secondary metabolites

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Authors: B. Makoudi, R. Ghanimi, A. Bargaz, M. Mouradi, M. Farissi, A. Kabbaj, J. J. Drevon, C. Ghoulam

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Legume species are able to establish a nitrogen fixing symbiosis with soil rhizobia that allows them, when it operates normally, to ensure their necessary nitrogen nutrition. This biological process needs high phosphorus (P) supply and consequently it is limited under low phosphorus availability. To overcome this constraint, legume-rhizobia symbiosis develops many mechanisms to increase P availability in the rhizosphere and also the efficiency of P fertilizers. The objectives of our research works are to understand the physiological and biochemical mechanisms implemented by legume-rhizobia symbiosis to increase its P use efficiency (PUE) in order to select legume genotypes-rhizobia strains combination more performing for BNF under P deficiency. Our studies were carried out on two grain legume species, common bean (Phaseolus vulgaris) and faba bean (Vicia faba) tested in farmers’ fields and in experimental station fewer than two soil phosphorus levels. Under field conditions, the P deficiency caused a significant decrease of Plant and nodule biomasses in all of the tested varieties with a difference between them. This P limitation increased the contents of available P in the rhizospheric soils that was positively correlated with the increase of phosphatases activities in the nodules and the rhizospheric soil. Some legume genotypes showed a significant increase of their P use efficiency under P deficiency. The P solubilization test showed that some rhizobia strains isolated from Haouz region presented an important capacity to grow on solid and liquid media with tricalcium phosphate as the only P source and their P solubilizing activity was confirmed by the assay of the released P in the liquid medium. Also, this P solubilizing activity was correlated with medium acidification and the excretion of acid phosphatases and phytases in the medium. Thus, we concluded that medium acidification and excretion of phosphatases in the rhizosphere are the prominent reactions for legume-rhizobia symbiosis to improve its P nutrition.

Keywords: legume, phosphorus deficiency, rhizobia, rhizospheric soil

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Authors: Nadia Hammouda, Kamel Belmokre

Abstract:

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in sea water by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness.

Keywords: epoxy paints, carbon steel, electrochemical impedance spectroscopy, corrosion mechanisms, seawater

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Authors: Popoola M. Oyenola

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Concrete plays the important role and a huge percentage of concrete is being utilized in every construction practices. Natural river sand is one of the major ingredients of concrete, is becoming expensive due to excessive cost of accessibility from sources. Also large scale depletion of sources creates environmental problems. Therefore, there is a need of economic alternative materials. Quarry dust is a waste obtained during quarrying process. It has been rampantly used in different construction practices and could be used as an effective fine aggregate instead of river sand. Partial and total replacement of fine aggregate in conventional concrete with quarry dust has been empirically conducted with the view to examining primarily the compressive strength of the resulting composite and possible total utilization of quarry dust as fine aggregate in the production of medium grade concrete. The results of the study showed that its specific gravity, porosity and water absorption showed satisfactory performance. The percentage replacement of natural river sand with quarry dust for a designed strength of 25N/mm2 varied at intervals of 10% up to a maximum value of 100%. A total of 132 cubes of 150 x 150 x 150mm were cast and tested at 7, 14 and 28 days of hydration. Compressive strength increases with curing age in all the mixes. Compressive strength decreases with increase in percentage of quarry dust. Generally the compressive strength of concrete incorporating quarry dust attained strength of 22.47 N/mm2 after 28 days which makes it a suitable aggregate for the production medium grade concrete.

Keywords: quarry dust, concrete, aggregates, compressive strength

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Authors: Valentina Rodas, Luis Almache

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The interaction effects between the existing soil and the substructure of a 5-story building with an underground one were evaluated in such a way that the structural-geotechnical concepts were validated through the method of impedance factors with a program based on the method of the finite elements. The continuous wall-type foundation had a constant thickness and followed inclined and orthogonal directions, while the ground had homogeneous and medium-type characteristics. The soil considered was type C according to the Ecuadorian Construction Standard (NEC) and the corresponding foundation comprised a depth of 4.00 meters and a basement wall thickness of 40 centimeters. This project is part of a mid-rise building in the city of Azogues (Ecuador). The hypotheses raised responded to the objectives in such a way that the model implemented with springs had a variation with respect to the embedded base, obtaining conservative results.

Keywords: interaction, soil, substructure, springs, effects, modeling , embedment

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Authors: Robert Prohaska, Arnaud Konan, Kenneth Kelly, Adam Ragatz, Adam Duran

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In an effort to evaluate the in-use performance of electrified Power Take-off (PTO) usage on bucket utility trucks operating under real-world conditions, data from 20 medium- and heavy-duty vehicles operating in California, USA were collected, compiled, and analyzed by the National Renewable Energy Laboratory's (NREL) Fleet Test and Evaluation team. In this paper, duty-cycle statistical analyses of class 5, medium-duty quick response trucks and class 8, heavy-duty material handler trucks are performed to examine and characterize vehicle dynamics trends and relationships based on collected in-use field data. With more than 100,000 kilometers of driving data collected over 880+ operating days, researchers have developed a robust methodology for identifying PTO operation from in-field vehicle data. Researchers apply this unique methodology to evaluate the performance and utilization of the conventional and electric PTO systems. Researchers also created custom representative drive-cycles for each vehicle configuration and performed modeling and simulation activities to evaluate the potential fuel and emissions savings for hybridization of the tractive driveline on these vehicles. The results of these analyses statistically and objectively define the vehicle dynamic and kinematic requirements for each vehicle configuration as well as show the potential for further system optimization through driveline hybridization. Results are presented in both graphical and tabular formats illustrating a number of key relationships between parameters observed within the data set that relates specifically to medium- and heavy-duty utility vehicles operating under real-world conditions.

Keywords: drive cycle, heavy-duty (HD), hybrid, medium-duty (MD), PTO, utility

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Authors: Ibrahim A. H. Barakat, Ahmed R. Al-Himaidi

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The present study was conducted to determine the role and optimum concentration of fenugreek seed extract during in-vitro maturation on in-vitro maturation and developmental competence of Neaimi sheep oocytes following in-vitro fertilization. The Cumulus Oocyte Complexes (COCs) collected from sheep slaughterhouse ovaries were randomly divided into three groups, and they were matured for 24 hrs. in maturation medium containing fenugreek seed extract (0, 1 and 10 µg ml-1). Oocytes of a control group were matured in a medium containing 1 µg ml-1 estradiol 17β. After maturation, half of oocytes were fixed and stained for evaluation of nuclear maturation. The rest of oocytes were fertilized in vitro with fresh semen, then cultured for 9 days for the assessment of the developmental capacity of the oocytes. The results showed that the mean values of oocytes with expanded cumulus cells percentage were not significantly different among all groups (P < 0.05). But nuclear maturation rate of oocytes matured with 10 µg ml-1 fenugreek seed extract was significantly higher than that of the control group. The maturation rate and development to morula and blastocyst stage for oocytes matured at 10 µg ml-1 fenugreek seed extract was significantly higher than those matured at 1µg ml-1 of fenugreek seed extract and the control group. In conclusion, better maturation and developmental capacity rate to morula and blastocyst stage were obtained by the addition of 10 µg ml-1 fenugreek seed extract to maturation medium than addition of 1 µg ml-1 estradiol-17β (P < 0.05).

Keywords: fenugreek seed extract, in vitro maturation, sheep oocytes, in vitro fertilization, embryo development

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Authors: Nadia Hammouda, K. Belmokre

Abstract:

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in sea water by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness.

Keywords: epoxy paints, carbon steel, electrochemical impedance spectroscopy, corrosion mechanisms, sea water

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Authors: Vaishali Joshi

Abstract:

In the past, companies and buyers operated as if there was infinite availability of natural resources for usage, which has resulted in the loss of our globe's natural ecosystem. People's consciousness of ecological concerns had increased, which showed the way for the evolution of the green revolution with the objective of discontinuing the use of products that are harmful to the ecosystem of the earth. This green revolution has made the consumers head toward those companies which are providing eco-friendly products s/service s through less eco-harmful ways. Studies show that companies started gaining a reputation in the market through their eco-friendly activities in their business. Hence companies should be alert to understand the consumer's environmentally friendly consumption behavior to survive and be in the game of the competition. Green marketing efforts guarantee beneficial exchanges without harmful consequences for current and /or upcoming generations. This hits the green policies of those companies which are claiming environmental concern. This means that these companies not only focus on the impact of their production and products on the ecosystem but also on every small activity in their value chain. One of the most ignored parts of the value chain is the medium through which the marketing of products/services is done. These companies should also take into account to what degree their selection of advertising media affects the ecosystem of the earth. In this study, a hypothetical fashion apparel brand known as "Dolphin" will be studied. In particular, the following objectives are framed: i) to study the brand attitude of the given fashion brand due to its selection of eco-friendly advertising medium ii) to study the advertisement attitude of the given fashion brand due to its selection of eco-friendly advertising medium and iii) to study the purchase intention of the given fashion brand due to its selection of eco-friendly advertising medium. An online experiment will be conducted. Respondents between the ages of 20-and 64 years will be selected randomly from the online consumer panel database. The findings of this study will have a great impact on the companies that are claiming environmental concerns by understanding how the advertising media is affecting the company’s brand image in the long run.

Keywords: eco-friendly advertising media, fashion, attitude, purchase intention

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Authors: F. Ghasim-akbari, A. M. Hadian, A. M. Aminazad

Abstract:

Fluid transmission pipes made of aluminum are widely use in petrochemical industries. For many applications they have to be brazed to each other. The brazed joints, in many cases, are encountered with corrosive medias. This paper reports a part of a work to investigate the corrosion behavior of brazed Al6061 using Al4047 as filler metal with and without the use of flux to discover the effect of different brazing atmospheres. The samples brazed under air, vacuum, argon, and hydrogen atmospheres. The interfacial area of the joints was examined to ensure being free of any defects. The sides of each test piece were covered with insulator and the surface of the joint was encountered to polarization test. The results revealed a significant difference of corrosion resistance. The samples that brazed under argon and hydrogen atmospheres had better corrosion resistance than other samples. Microstructure of the corroded joints revealed that the amount of the filler metal is a critical parameter on corrosion resistance of the joints.

Keywords: brazing, corrosion behavior, Al6061, polarization

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Authors: Raoudha Chaabane, Faouzi Askri, Sassi Ben Nasrallah

Abstract:

A new numerical algorithm is developed to solve coupled convection-radiation heat transfer in a two dimensional enclosure. Radiative heat transfer in participating medium has been carried out using the control volume finite element method (CVFEM). The radiative transfer equations (RTE) are formulated for absorbing, emitting and scattering medium. The density, velocity and temperature fields are calculated using the two double population lattice Boltzmann equation (LBE). In order to test the efficiency of the developed method the Rayleigh Benard convection with and without radiative heat transfer is analyzed. The obtained results are validated against available works in literature and the proposed method is found to be efficient, accurate and numerically stable.

Keywords: participating media, LBM, CVFEM- radiation coupled with convection

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Authors: Iruka C. Anugwo, Winston M. Shakantu

Abstract:

The objective of this study is to uncover the basic business-forces that necessitated the survival and sustainable performance of the medium scale contractors in the South African construction market. This study is essential as it set to contribute towards long-term strategic solutions for combating the incessant failure of start-ups construction organizations within South African. The study used a qualitative research methodology; as the most appropriate approach to elicit and understand, and uncover the phenomena that are basic business-forces for the active contractors in the market. The study also adopted a phenomenological study approach; and in-depth interviews were conducted with 20 medium scale contractors in Port Elizabeth, South Africa, between months of August to October 2015. This allowed for an in-depth understanding of the critical and basic business-forces that influenced their survival and performance beyond the first five years of business operation. Findings of the study showed that for potential contractors (startups), to survival in the competitive business environment such as construction industry, they must possess the basic business-forces. These forces are educational knowledge in construction and business management related disciplines, adequate industrial experiences, competencies and capabilities to delivery excellent services and products as well as embracing the spirit of entrepreneurship. Convincingly, it can be concluded that the strategic approach to minimize the endless failure of startups construction businesses; the potential construction contractors must endeavoring to access and acquire the basic educationally knowledge, training and qualification; need to acquire industrial experiences in collaboration with required competencies, capabilities and entrepreneurship acumen. Without these basic business-forces as been discovered in this study, the majority of the contractors gaining entrance in the market will find it difficult to develop and grow a competitive and sustainable construction organization in South Africa.

Keywords: basic business-forces, medium scale contractors, South Africa, sustainable organisations

Procedia PDF Downloads 259