Search results for: medium entropy alloy matrix composite

Authors: Mohammad-Ali Latifi, Harry Bouwman

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Changes in the business environment accelerated dramatically over the last decades as a result of changes in technology, regulation, market, and competitors’ behavior. Firms need to change the way they do business in order to survive or maintain their growth. Innovating business model (BM) can create competitive advantages and enhance firm performance. However, many companies fail to achieve expected outcomes in practice, mostly due to irreversible fundamental changes in key components of the company’s BM. This leads to more ambiguity, uncertainty, and risks associated with business performance. However, the relationship among BM Innovation, moderating factors, and the firm’s overall performance is by and large ignored in the current literature. In this study, we identified twenty moderating factors from our comprehensive literature review. We categorized these factors based on two criteria regarding the extent to which: the moderating factors can be controlled and managed by firms, and they are generic or specific changes to the firms. This leads to four moderation groups. The first group is BM implementation, which includes management support, employees’ commitment, employees’ skills, communication, detailed plan. The second group is called BM practices, which consists of BM tooling, BM experimentation, the scope of change, speed of change, degree of novelty. The third group is Firm characteristics, including firm size, age, and ownership. The last group is called Industry characteristics, which considers the industry sector, competitive intensity, industry life cycle, environmental dynamism, high-tech vs. low-tech industry. Through collecting data from 508 European small and medium-sized enterprises (SMEs) and using the structural equation modeling technique, the developed moderation model was examined. Results revealed that all factors highlighted through these four groups moderate the relation between BMI and firm performance significantly. Particularly, factors related to BM-Implementation and BM-Practices are more manageable and would potentially improve firm overall performance. We believe that this result is more important for researchers and practitioners since the possibility of working on factors in Firm characteristics and Industry characteristics groups are limited, and the firm can hardly control and manage them to improve the performance of BMI efforts.

Keywords: business model innovation, firm performance, implementation, moderation

Procedia PDF Downloads 120

Authors: A. Kalizhanova, T. Shelestova

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Teacher professional development (TPD) in Kazakhstan has followed a fairly standard format for centuries, with teachers learning new information from a lecturer and being tested using multiple-choice questions. In the online world, self-access courses have become increasingly popular. Due to their extensive multimedia content, peer-reviewed assignments, adaptable class times, and instruction from top university faculty from across the world, massive open online courses (MOOCs) have found a home in Kazakhstan's system for lifelong learning. Recent studies indicate the limited use of connectivism-based tools such as discussion forums by Kazakhstani pre-service and in-service English teachers, whose professional interests are limited to obtaining certificates rather than enhancing their teaching abilities and exchanging knowledge with colleagues. This paper highlights the significance of connectivism-based tools and instruments, such as MOOCs, for the continuous professional development of pre- and in-service English teachers, facilitators' roles, and their strategies for enhancing trainees' conceptual knowledge within the MOOCs' curriculum and online learning skills. Reviewing the most pertinent papers on Connectivism Theory, facilitators' function in TPD, and connectivism-based tools, such as MOOCs, a code extraction method was utilized. Three experts, former active participants in a series of projects initiated across Kazakhstan to improve the efficacy of MOOCs, evaluated the excerpts and selected the most appropriate ones to propose the matrix of teacher professional competencies that can be acquired through MOOCs. In this paper, we'll look at some of the strategies employed by course instructors to boost their students' English skills and knowledge of course material, both inside and outside of the MOOC platform. Participants' interactive learning contributed to their language and subject conceptual knowledge and prepared them for peer-reviewed assignments in the MOOCs, and this approach of small group interaction was given to highlight the outcomes of participants' interactive learning. Both formal and informal continuing education institutions can use the findings of this study to support teachers in gaining experience with MOOCs and creating their own online courses.

Keywords: connectivism-based tools, teacher professional development, massive open online courses, facilitators, Kazakhstani context

Procedia PDF Downloads 80

Authors: Hammad T. Janjuhah, Josep Sanjuan, Mohamed K. Salah

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Biological and chemical activities in carbonates are responsible for the complexity of the pore system. Primary porosity is generally of natural origin while secondary porosity is subject to chemical reactivity through diagenetic processes. To understand the integrated part of hydrocarbon exploration, it is necessary to understand the carbonate pore system. However, the current porosity classification scheme is limited to adequately predict the petrophysical properties of different reservoirs having various origins and depositional environments. Rock classification provides a descriptive method for explaining the lithofacies but makes no significant contribution to the application of porosity and permeability (poro-perm) correlation. The Central Luconia carbonate system (Malaysia) represents a good example of pore complexity (in terms of nature and origin) mainly related to diagenetic processes which have altered the original reservoir. For quantitative analysis, 32 high-resolution images of each thin section were taken using transmitted light microscopy. The quantification of grains, matrix, cement, and macroporosity (pore types) was achieved using a petrographic analysis of thin sections and FESEM images. The point counting technique was used to estimate the amount of macroporosity from thin section, which was then subtracted from the total porosity to derive the microporosity. The quantitative observation of thin sections revealed that the mouldic porosity (macroporosity) is the dominant porosity type present, whereas the microporosity seems to correspond to a sum of 40 to 50% of the total porosity. It has been proven that these Miocene carbonates contain a significant amount of microporosity, which significantly complicates the estimation and production of hydrocarbons. Neglecting its impact can increase uncertainty about estimating hydrocarbon reserves. Due to the diversity of geological parameters, the application of existing porosity classifications does not allow a better understanding of the poro-perm relationship. However, the classification can be improved by including the pore types and pore structures where they can be divided into macro- and microporosity. Such studies of microporosity identification/classification represent now a major concern in limestone reservoirs around the world.

Keywords: overview of porosity classification, reservoir characterization, microporosity, carbonate reservoir

Procedia PDF Downloads 154

Authors: Noorizal Huang, Christian Girsang, Mohamad Razi Mansoor

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Shallow gas seepage was first spotted at a central processing platform offshore Malaysia in 2010, acknowledged as Platform T in this paper. Frequent monitoring of the gas seepage was performed through remotely operated vehicle (ROV) baseline survey and a comprehensive geophysical survey was conducted to understand the characteristics of the gas seepage and to ensure that the integrity of the foundation at Platform T was not compromised. The origin of the gas back then was unknown. A soil investigation campaign was performed in 2016 to study the origin of the gas seepage. Two boreholes were drilled; a composite borehole to 150m below seabed for the purpose of soil sampling and in-situ testing and a pilot hole to 155m below the seabed, which was later converted to a fit-for-purpose relief well as an alternate migration path for the gas. During the soil investigation campaign, dissipation tests were performed at several layers which were potentially the source or migration path for the gas. Five (5) soil samples were segregated for headspace test, to identify the gas type which subsequently can be used to identify the origin of the gas. Dissipation tests performed at four depth intervals indicates pore water pressure less than 20 % of the effective vertical stress and appear to continue decreasing if the test had not been stopped. It was concluded that a low to a negligible amount of excess pore pressure exist in clayey silt layers. Results from headspace test show presence of methane corresponding to the clayey silt layers as reported in the boring logs. The gas most likely comes from biogenic sources, feeding on organic matter in situ over a large depth range. It is unlikely that there are large pockets of gas in the soil due to its homogeneous clayey nature and the lack of excess pore pressure in other permeable clayey silt layers encountered. Instead, it is more likely that when pore water at certain depth encounters a more permeable path, such as a borehole, it rises up through this path due to the temperature gradient in the soil. As the water rises the pressure decreases, which could cause gases dissolved in the water to come out of solution and form bubbles. As a result, the gas will have no impact on the integrity of the foundation at Platform T. The fit-for-purpose relief well design as well as adopting headspace testing can be used to address the shallow gas issue at Platform T in a cost effective and efficient manners.

Keywords: dissipation test, headspace test, excess pore pressure, relief well, shallow gas

Procedia PDF Downloads 273

Authors: Sonya Barzgar, J. Patrick, A. Hettiaratchi

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Methane (CH4) is reputed as the second largest contributor to greenhouse effect with a global warming potential (GWP) of 34 related to carbon dioxide (CO2) over the 100-year horizon, so there is a growing interest in reducing the emissions of this gas. Methane biofiltration (MBF) is a cost effective technology for reducing low volume point source emissions of methane. In this technique, microbial oxidation of methane is carried out by methane-oxidizing bacteria (methanotrophs) which use methane as carbon and energy source. MBF uses a granular medium, such as soil or compost, to support the growth of methanotrophic bacteria responsible for converting methane to carbon dioxide (CO₂) and water (H₂O). Even though the biofiltration technique has been shown to be an efficient, practical and viable technology, the design and operational parameters, as well as the relevant microbial processes have not been investigated in depth. In particular, limited research has been done on the effects of sulphur on methane bio-oxidation. Since bacteria require a variety of nutrients for growth, to improve the performance of methane biofiltration, it is important to establish the input quantities of nutrients to be provided to the biofilter to ensure that nutrients are available to sustain the process. The study described in this paper was conducted with the aim of determining the influence of sulphur on methane elimination in a biofilter. In this study, a set of experimental measurements has been carried out to explore how the conversion of elemental sulphur could affect methane oxidation in terms of methanotrophs growth and system pH. Batch experiments with different concentrations of sulphur were performed while keeping the other parameters i.e. moisture content, methane concentration, oxygen level and also compost at their optimum level. The study revealed the tolerable limit of sulphur without any interference to the methane oxidation as well as the particular sulphur concentration leading to the greatest methane elimination capacity. Due to the sulphur oxidation, pH varies in a transient way which affects the microbial growth behavior. All methanotrophs are incapable of growth at pH values below 5.0 and thus apparently are unable to oxidize methane. Herein, the certain pH for the optimal growth of methanotrophic bacteria is obtained. Finally, monitoring methane concentration over time in the presence of sulphur is also presented for laboratory scale biofilters.

Keywords: global warming, methane biofiltration (MBF), methane oxidation, methanotrophs, pH, sulphur

Procedia PDF Downloads 236

Authors: Nur Aimi Syairah Mohd Abdul Alim, Azilah Ajit, A. Z. Sulaiman

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The present study aimed to investigate the effects of ultrasound-assisted extraction (UAE) on the extraction of Vitexin and Iso-Vitexin from Ficus deltoidea plants. In recent years, ultrasound technology has been found to be a potential herbal extraction technique. The passage of ultrasound energy in a liquid medium generates mechanical agitation and other physical effects due to acoustic cavitation. The main goal is to optimised ultrasonic-assisted extraction condition providing the highest extraction yield with the most desirable antioxidant activity and stability. Thus, a series of experiments has been developed to investigate the effect of ultrasound energy on the vegetal material and the implemented parameters by using HPLC-photodiode array detection. The influences of several experimental parameters on the ultrasonic extraction of Ficus deltoidea leaves were investigated: extraction time (1-8 h), solvent-to-water ratio (1:10 to 1:50), temperature (50–100 °C), duty cycle (10–continuous sonication) and intensity. The extracts at the optimized condition were compared with those obtained by conventional boiling extraction, in terms of bioactive constituents yield and chemical composition. The compounds of interest identified in the extracts were Vitexin and Isovitexin, which possess anti-diabetic, anti-oxidant and anti-cancer properties. Results showed that the main variables affecting the extraction process were temperature and time. Though in less extent, solvent-to-water ratio, duty cycle and intensity are also demonstrated to be important parameters. The experimental values under optimal conditions were in good consistent with the predicted values, which suggested that ultrasonic-assisted extraction (UAE) is more efficient process as compared to conventional boiling extraction. It recommended that ultrasound extraction of Ficus deltoidea plants are feasible to replace the traditional time-consuming and low efficiency preparation procedure in the future modernized and commercialized manufacture of this highly valuable herbal medicine.

Keywords: Ficus, ultrasounds, vitexin, isovitexin

Procedia PDF Downloads 416

Authors: Rene Hellmuth, Jorg Frohnmayer

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The requirements of the factory planning and the building concerned have changed in the last years. Factory planning has the task of designing products, plants, processes, organization, areas, and the building of a factory. Regular restructuring gains more importance in order to maintain the competitiveness of a factory. Even today, the methods and process models used in factory planning are predominantly based on the classical planning principles of Schmigalla, Aggteleky and Kettner, which, however, are not specifically designed for reorganization. In addition, they are designed for a largely static environmental situation and a manageable planning complexity as well as for medium to long-term planning cycles with a low variability of the factory. Existing approaches already regard factory planning as a continuous process that makes it possible to react quickly to adaptation requirements. However, digital factory models are not yet used as a source of information for building data. Approaches which consider building information modeling (BIM) or digital factory models in general either do not refer to factory conversions or do not yet go beyond a concept. This deficit can be further substantiated. A method for factory conversion planning using a current digital building model is lacking. A corresponding approach must take into account both the existing approaches to factory planning and the use of digital factory models in practice. A literature review will be conducted first. In it, approaches to classic factory planning and approaches to conversion planning are examined. In addition, it will be investigated which approaches already contain digital factory models. In the second step, an approach is presented how digital factory models based on building information modeling can be used as a basis for augmented reality tablet applications. This application is suitable for construction sites and provides information on the costs and time required for conversion variants. Thus a fast decision making is supported. In summary, the paper provides an overview of existing factory planning approaches and critically examines the use of digital tools. Based on this preliminary work, an approach is presented, which suggests the sensible use of digital factory models for decision support in the case of conversion variants of the factory building. The augmented reality application is designed to summarize the most important information for decision-makers during a reconstruction process.

Keywords: augmented reality, digital factory model, factory planning, restructuring

Procedia PDF Downloads 138

Authors: Teresa Isabel Lozano Pérez, Sandra Soca Lozano

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In Cuba, the childcare is one of the programs prioritized by the Ministry of Public Health and the birth of a child becomes a desired and rewarding event for the family, which is prepared for the reception of a healthy child. When this does not happen and after the first months of the child's birth begin to appear developmental deviations that indicate the presence of a disorder, the event becomes a live event potentially negative and generates disruptions in the family health. A quantitative, descriptive, and cross-sectional research methodology was conducted to describe the impact on family health of diagnosis of autism in a sample of 25 families of children diagnosed with infantile autism at the University Pediatric Hospital Juan Manuel Marquez Havana, Cuba; in the period between January 2014 and May 2015. The sample was non probabilistic and intentional from the inclusion criteria selected. As instruments, we used a survey to identify the structure of the family, life events inventory and an instrument to assess the relative impact, adaptive resources of family and social support perceived (IRFA) to identify the diagnosis of autism as life event. The main results indicated that the majority of families studied were nuclear, small and medium and in the formation stage. All households surveyed identified the diagnosis of autism in a child as an event of great importance and negative significance for the family, taking in most of the families studied a high impact on the four areas of family health and impact enhancer of involvement in family health. All the studied families do not have sufficient adaptive resources to face this situation, sensing that they received social support frequently, mainly in information and emotional areas. We conclude that the diagnosis of autism one of the members of the families studied is valued as a life event highly significant with unfavorably way causing an enhancer impact of involvement in family health especially in the areas ‘health’ and ‘socio-psychological’. Among the social support networks health institutions, partners and friends are highlighted. We recommend developing intervention strategies in families of these children to support them in the process of adapting the diagnosis.

Keywords: family, family health, infantile autism, life event

Procedia PDF Downloads 431

Authors: Hadiatullah, T. S. D. Desak Ketut, A. A. Ayu, A. N. Isna, D. P. Ririn

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Spirogyra sp. is genus of microalgae which has a high carbohydrate content that used as a best medium for bacterial fermentation to produce cellulose. This study objective to determine the effect of pulp banana in the fermented paper production process using Spirogyra sp. and characterizing of the paper product. The method includes the production of bacterial cellulose, assay of the effect fermented paper interpolating with banana pulp using Spirogyra sp., and the assay of paper characteristics include gram-mage paper, water assay absorption, thickness, power assay of tensile resistance, assay of tear resistance, density, and organoleptic assay. Experiments were carried out with completely randomized design with a variation of the concentration of sewage treatment in the fermented paper production interpolating banana pulp using Spirogyra sp. Each parameter data to be analyzed by Anova variance that continued by real difference test with an error rate of 5% using the SPSS. Nata production results indicate that different carbon sources (glucose and sugar) did not show any significant differences from cellulose parameters assay. Significantly different results only indicated for the control treatment. Although not significantly different from the addition of a carbon source, sugar showed higher potency to produce high cellulose. Based on characteristic assay of the fermented paper showed that the paper gram-mage indicated that the control treatment without interpolation of a carbon source and a banana pulp have better result than banana pulp interpolation. Results of control gram-mage is 260 gsm that show optimized by cardboard. While on paper gram-mage produced with the banana pulp interpolation is about 120-200 gsm that show optimized by magazine paper and art paper. Based on the density, weight, water absorption assays, and organoleptic assay of paper showing the highest results in the treatment of pulp banana interpolation with sugar source as carbon is 14.28 g/m2, 0.02 g and 0.041 g/cm2.minutes. The conclusion found that paper with nata material interpolating with sugar and banana pulp has the potential formulation to produce super-quality paper.

Keywords: cellulose, fermentation, grammage, paper, Spirogyra sp.

Procedia PDF Downloads 333

Authors: Vitor Carneiro, Augusto Barata Da Rocha, Barbara Rangel, Jorge Lino Alves

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In the European Union countries, Small and Medium-Sized Enterprises (SME’s) have an important contribution to economic activity and to the Gross Domestic Product (GDP). The implementation of design practices in SME’s is often a difficult task due to resources limitations. Unlike large companies, their product development and innovation processes frequentlylack adequate planning and systematic procedures. Design management interest has grown exponentially in recent years, but as it is a recent topic there is an absence of systematic methodologies to implement design management in SME’s with little or no design experience. This work presents a contribution to improve and optimize the process of design integration and management in SME’s. A review analysis is presented to select relevant articles on the subject, review and classify the main published contributions. Based on the selected articles content it was possible to identify five main themes related to the subject under analysis: Design Function Organization, Design Management Integration, Design Management Capabilities, Managing Design Projects, and Tools and Methods. Design management is discussed from different perspectives depending on the focus on which it is placed, whether in a design or management perspective, leading to different visions and definitions: from a more upstream strand at the intersection of design and the organization's strategic management (strategic design management) to a more downstream strand related to project management and design process (design management operational). The review analysis of the selected articles allowed the identification of a high level of complexity of connections and parameters in the design management during the product development process in the context of SME’s. Within each group of the five main themes, several sub-themes, directly or indirectly related, should be considered.Sub-connections also occur between sub-themes of different themes creating a complex and intricate web of connections. This complexity of connections is often the main obstacle to conduct design management and product development efficiently. This work proposes a formulation of a systematic methodological approach to optimize the integrated project and the management and control of the product development process among SME's. The implementation of this formulation will improve the integration of design management in the product development and innovation process in SME’s.

Keywords: design management, product development, product innovation, SME’s.

Procedia PDF Downloads 222

Authors: Blanco T. F., Fernández-López A.

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Nowadays, education, motivated by the new demands of the 21st century, acquires a dimension that converts the skills that new generations may need into a huge and uncertain set of knowledge too broad to be entirety covered. Within this set, and as tools to reach them, we find Learning and Knowledge Technologies (LKT). Thus, in order to prepare students for an everchanging society in which the technological boom involves everything, it is essential to develop digital competence. Nevertheless LKT seems not to have found their place in the educational system. This work is aimed to go a step further in the research of the most appropriate procedures and resources for technological integration in the classroom. The main objective of this exploratory study is to analyze the didactic suitability (epistemic, cognitive, affective, interactional, mediational and ecological) for teaching and learning processes of mathematics with robotics and 3D printing. The analysis carried out is drawn from a STEAM (Science, Technology, Engineering, Art and Mathematics) project that has the Pilgrimage way to Santiago de Compostela as a common thread. The sample is made up of 25 Primary Education students (10 and 11 years old). A qualitative design research methodology has been followed, the sessions have been distributed according to the type of technology applied. Robotics has been focused towards learning two-dimensional mathematical notions while 3D design and printing have been oriented towards three-dimensional concepts. The data collection instruments used are evaluation rubrics, recordings, field notebooks and participant observation. Indicators of didactic suitability proposed by Godino (2013) have been used for the analysis of the data. In general, the results show a medium-high level of didactic suitability. Above these, a high mediational and cognitive suitability stands out, which led to a better understanding of the positions and relationships of three-dimensional bodies in space and the concept of angle. With regard to the other indicators of the didactic suitability, it should be noted that the interactional suitability would require more attention and the affective suitability a deeper study. In conclusion, the research has revealed great expectations around the combination of teaching-learning processes of mathematics and LKT. Although there is still a long way to go in terms of the provision of means and teacher training.

Keywords: 3D printing, didactic suitability, educational design, robotics

Procedia PDF Downloads 104

Authors: Berta Rodrigues Maia, Mariana Marques, Frederica Carvalho

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Introduction: Personality traits play is related to many forms of psychological distress, such as body dissatisfaction. Aim: To explore the associations between appearance schemas and personality traits. Method: 494 Portuguese university students (80.2% females, and 99.2% single), with a mean age of 20.17 years old (SD = 1.77; range: 18-20), filled in the appearance schemas inventory-revised, the NEO personality inventory (a Portuguese short version), and the composite multidimensional perfectionism scale. Results: An independent-samples t-test was conducted to compare the scores in appearance schemas by sex, with a significant difference being found in self-evaluation salience scores [females (M = 37.99, SD = 7.82); males (M = 35.36, SD = 6.60); t (489) = -3.052, p = .002]. Finally, there was no significant difference in motivational salience scores, by sex [females (M = 27.67, SD = 4.84); males (M = 26.70, SD = 4.99); t (489) = -1.748, p = .081]. Having conducted correlations separately, by sex, self-evaluation salience was positively correlated with concern over mistakes (r = .27), doubts about actions (r = .35), and socially prescribed perfectionism (r = .23). moreover, for females, self-evaluation salience was positively correlated with concern over mistakes (r = .34), personal standards (r = .25), doubts about actions (r = .33), parental expectations (r = .24), parental criticism (r = .24), organization (r = .11), socially prescribed perfectionism (r = .31), self-oriented perfectionism (r = .32), and neuroticism (r = .33). concerning motivational salience, in the total sample (not separately, by sex), this scale/dimension significantly correlated with conscientiousness (r = . 18), personal standards (r = .23), socially prescribed perfectionism (r = . 10), and self-oriented perfectionism (r = .29). All correlations were significant at a level of significance of 0.01 (2-tailed), except for socially prescribed perfectionism. All the other correlations (with neuroticism, extroversion, openness, agreeableness, concern over mistakes, doubts about actions, parental expectations, and parental criticism) were not significant. Conclusions: Females seem to value more their self-appearance than males, and, in females, the salience of appearance in life seems to be associated with maladaptive perfectionism, as well as with adaptive perfectionism. In males, the salience of appearance was only related to adaptive perfectionism. These results seem to show that males are more concerned with their own standards regarding appearance, while for females, other's standards are also relevant. In females, the level of the salience of appearance in life seems to relate to the experience of feelings, such as anxiety and depression (neuroticism). The motivation to improve appearance seemed to be particularly related, in both sexes, to adaptive perfectionism (in a general way concerning more the personal standards). Longitudinal studies are needed to clarify the causality of the results. Acknowledgment: This study was carried out under the strategic project of the Centre for Philosophical and Humanistic Studies (CEFH) UID/FIL/00683/2019, funded by the Fundação para a Ciência e a Tecnologia (FCT).

Keywords: appearance schemas, personality traits, university students, sex

Procedia PDF Downloads 129

Authors: M. Amanipour, J. Towfighi, E. Ganji Babakhani, M. Heidari

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Cylindrical alumina microfiltration membrane (GMITM Corporation, inside diameter=9 mm, outside diameter=13 mm, length= 50 mm) with an average pore size of 0.5 micrometer and porosity of about 0.35 was used as the support for membrane reactor. This support was soaked in boehmite sols, and the mean particle size was adjusted in the range of 50 to 500 nm by carefully controlling hydrolysis time, and calcined at 650 °C for two hours. This process was repeated with different boehmite solutions in order to achieve an intermediate layer with an average pore size of about 50 nm. The resulting substrate was then coated with a thin and dense layer of silica by counter current chemical vapour deposition (CVD) method. A boehmite sol with 10 wt.% of nickel which was prepared by a standard procedure was used to make the catalytic layer. BET, SEM, and XRD analysis were used to characterize this layer. The catalytic membrane reactor was placed in an experimental setup to evaluate the permeation and hydrogen separation performance for a steam reforming reaction. The setup consisted of a tubular module in which the membrane was fixed, and the reforming reaction occurred at the inner side of the membrane. Methane stream, diluted with nitrogen, and deionized water with a steam to carbon (S/C) ratio of 3.0 entered the reactor after the reactor was heated up to 500 °C with a specified rate of 2 °C/ min and the catalytic layer was reduced at presence of hydrogen for 2.5 hours. Nitrogen flow was used as sweep gas through the outer side of the reactor. Any liquid produced was trapped and separated at reactor exit by a cold trap, and the produced gases were analyzed by an on-line gas chromatograph (Agilent 7890A) to measure total CH₄ conversion and H₂ permeation. BET analysis indicated uniform size distribution for catalyst with average pore size of 280 nm and average surface area of 275 m².g^-1. Single-component permeation tests were carried out for hydrogen, methane, and carbon dioxide at temperature range of 500-800 °C, and the results showed almost the same permeance and hydrogen selectivity values for hydrogen as the composite membrane without catalytic layer. Performance of the catalytic membrane was evaluated by applying membranes as a membrane reactor for methane steam reforming reaction at gas hourly space velocity (GHSV) of 10,000 h⁻¹ and 2 bar. CH₄ conversion increased from 50% to 85% with increasing reaction temperature from 600 °C to 750 °C, which is sufficiently above equilibrium curve at reaction conditions, but slightly lower than membrane reactor with packed nickel catalytic bed because of its higher surface area compared to the catalytic layer.

Keywords: catalytic membrane, hydrogen, methane steam reforming, permeance

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Authors: Mahsa Ahmadi, Mehdi Mehdikhani-Nahrkhalaji, Jaleh Varshosaz, Shadi Farsaei

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Gelatin and hyaluronic acid are commonly used in skin tissue engineering scaffolds, but because of their low mechanical properties and high biodegradation rate, adding a synthetic polymer such as polycaprolactone could improve the scaffold properties. Therefore, we developed a gelatin-hyaluronic acid-polycaprolactone scaffold, containing 0.5 % atorvastatin loaded nanostructured lipid carriers (NLCs) for skin tissue engineering. The atorvastatin loaded NLCs solution was prepared by solvent evaporation method and freeze drying process. Synthesized atorvastatin loaded NLCs was added to the gelatin and hyaluronic acid solution, and a membrane was fabricated with solvent evaporation method. Thereafter it was coated by a thin layer of polycaprolactone via spine coating set. The resulting scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. Moreover, mechanical properties, in vitro degradation in 7 days period, and in vitro drug release of scaffolds were also evaluated. SEM images showed the uniform distributed NLCs with an average size of 100 nm in the scaffold structure. Mechanical test indicated that the scaffold had a 70.08 Mpa tensile modulus which was twofold of tensile modulus of normal human skin. A Franz-cell diffusion test was performed to investigate the scaffold drug release in phosphate buffered saline (pH=7.4) medium. Results showed that 72% of atorvastatin was released during 5 days. In vitro degradation test demonstrated that the membrane was degradated approximately 97%. In conclusion, suitable physicochemical and biological properties of membrane indicated that the developed gelatin-hyaluronic acid-polycaprolactone nanocomposite scaffold containing 0.5 % atorvastatin loaded NLCs could be used as a good candidate for skin tissue engineering applications.

Keywords: atorvastatin, gelatin, hyaluronic acid, nano lipid carriers (NLCs), polycaprolactone, skin tissue engineering, solvent casting, solvent evaporation

Procedia PDF Downloads 252

Authors: Asmaa Abazaid, Maram Al-Ostah, Nadeen Abu-Zahra, Ruba Bawab, Refaat Abdel-Razek

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Innovation audit is defined as a tool that can be used to reflect on how the innovation is managed in an organization. The aim of this study is to audit innovation in the second top Engineering Firms in the world, and one of the Small Medium Enterprises (SMEs) companies that are working in United Arab Emirates (UAE). The obtained results are then compared with four international companies from China and Brazil. The Diamond model has been used for auditing innovation in the two companies in UAE to evaluate their innovation management and to identify each company’s strengths and weaknesses from an innovation perspective. The results of the comparison between the two companies (Jacobs and Hyper General Contracting) revealed that Jacobs has support for innovation, its innovation processes are well managed, the company is committed to the development of its employees worldwide and the innovation system is flexible. Jacobs was doing best in all innovation management dimensions: strategy, process, organization, linkages and learning, while Hyper General Contracting did not score as Jacobs in any of the innovation dimensions. Furthermore, the audit results of both companies were compared with international companies to examine how well the two construction companies in UAE manage innovation relative to SABIC (Saudi company), Poly Easy and Arnious (Brazilian companies), Huagong tools and Guizohou Yibai (Chinese companies). The results revealed that Jacobs is doing best in learning and organization dimensions, while PolyEasy and Jacobs are equal in the linkage dimension. Huagong Tools scored the highest score in process dimension among all the compared companies. However, the highest score of strategy dimension was given to PolyEasy. On the other hand, Hyper General Contracting scored the lowest in all of the innovation management dimensions. It needs to improve its management of all the innovation management dimensions with special attention to be given to strategy, process, and linkage as they got scores below 4 out of 7 comparing with other dimensions. Jacobs scored the highest in three innovation management dimensions related to the six companies. However, the strategy dimension is considered low, and special attention is needed in this dimension.

Keywords: Brazil, China, innovation audit, innovation evaluation, innovation management, Saudi Arabia, United Arab Emirates

Procedia PDF Downloads 285

Authors: Sidrah Ahmed

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The river and lakes flows are modeled mathematically by shallow water equations that are depth-averaged Reynolds Averaged Navier-Stokes equations under Boussinesq approximation. The temperature stratification dynamics influence the water quality and mixing characteristics. It is mainly due to the atmospheric conditions including air temperature, wind velocity, and radiative forcing. The experimental observations are commonly taken along vertical scales and are not sufficient to estimate small turbulence effects of temperature variations induced characteristics of shallow flows. Wind shear stress over the water surface influence flow patterns, heat fluxes and thermodynamics of water bodies as well. Hence it is crucial to couple temperature gradients with shallow water model to estimate the atmospheric effects on flow patterns. The Ripa system has been introduced to study ocean currents as a variant of shallow water equations with addition of temperature variations within the flow. Ripa model is a hyperbolic system of partial differential equations because all the eigenvalues of the system’s Jacobian matrix are real and distinct. The time steps of a numerical scheme are estimated with the eigenvalues of the system. The solution to Riemann problem of the Ripa model is composed of shocks, contact and rarefaction waves. Solving Ripa model with Riemann initial data with the central schemes is difficult due to the eigen structure of the system.This works presents the comparison of four different finite difference schemes for the numerical solution of Riemann problem for Ripa model. These schemes include Lax-Friedrichs, Lax-Wendroff, MacCormack scheme and a higher order finite difference scheme with WENO method. The numerical flux functions in both dimensions are approximated according to these methods. The temporal accuracy is achieved by employing TVD Runge Kutta method. The numerical tests are presented to examine the accuracy and robustness of the applied methods. It is revealed that Lax-Freidrichs scheme produces results with oscillations while Lax-Wendroff and higher order difference scheme produce quite better results.

Keywords: finite difference schemes, Riemann problem, shallow water equations, temperature gradients

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Authors: Alexander I. Dovgyallo, Evgeniy A. Zinoviev, Svetlana O. Nekrasova

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The most of works applied for the pulse tube converters contain the workflow description implemented through the use of mathematical models on stationary modes. However, the study of the thermoacoustic systems unsteady behavior in the start, stop, and acoustic load changes modes is in the particular interest. The aim of the present study was to develop a mathematical thermal excitation model of acoustic oscillations in pulse tube engine (PTE) as a small-scale scheme of pulse tube engine operating at atmospheric air. Unlike some previous works this standing wave configuration is a fully closed system. The improvements over previous mathematical models are the following: the model allows specifying any values of porosity for regenerator, takes into account the piston weight and the friction in the cylinder and piston unit, and determines the operating frequency. The numerical method is based on the relation equations between the pressure and volume velocity variables at the ends of each element of PTE which is recorded through the appropriate transformation matrix. A solution demonstrates that the PTE operation frequency is the complex value, and it depends on the piston mass and the dynamic friction due to its movement in the cylinder. On the basis of the determined frequency thermoacoustically induced heat transport and generation of acoustic power equations were solved for channel with temperature gradient on its ends. The results of numerical simulation demonstrate the features of the initialization process of oscillation and show that that generated acoustic power more than power on the steady mode in a factor of 3…4. But doesn`t mean the possibility of its further continuous utilizing due to its existence only in transient mode which lasts only for a 30-40 sec. The experiments were carried out on small-scale PTE. The results shows that the value of acoustic power is in the range of 0.7..1.05 W for the defined frequency range f = 13..18 Hz and pressure amplitudes 11..12 kPa. These experimental data are satisfactorily correlated with the numerical modeling results. The mathematical model can be straightforwardly applied for the thermoacoustic devices with variable temperatures of thermal reservoirs and variable transduction loads which are expected to occur in practical implementations of portable thermoacoustic engines.

Keywords: nonlinear processes, pulse tube engine, thermal excitation, standing wave

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Authors: Hitoshi Minakuchi, Izumi Takei, Shu Wakino, Koichi Hayashi, Hiroshi Itoh

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Objectives: Among type 2 diabetics, patients with CKD(chronic kidney disease), insulin resistance, impaired glyconeogenesis in kidney and reduced degradation of insulin are recognized, and we observed different fluctuational patterns of blood sugar between CKD patients and non-CKD patients. On the other hand, non-dipper type blood pressure change is the risk of organ damage and mortality. We performed cross-sectional study to elucidate the characteristic of the fluctuation of blood glucose and blood pressure at insulin-treated diabetic patients with chronic kidney disease. Methods: From March 2011 to April 2013, at the Ichikawa General Hospital of Tokyo Dental College, we recruited 20 outpatients. All participants are insulin-treated type 2 diabetes with CKD. We collected serum samples, urine samples for several hormone measurements, and performed CGMS(Continuous glucose measurement system), ABPM (ambulatory blood pressure monitoring), brain computed tomography, carotid artery thickness, ankle brachial index, PWV, CVR-R, and analyzed these data statistically. Results: Among all 20 participants, hypoglycemia was decided blood glucose 70mg/dl by CGMS of 9 participants (45.0%). The event of hypoglycemia was recognized lower eGFR (29.8±6.2ml/min：41.3±8.5ml/min, P<0.05), lower HbA1c (6.44±0.57%：7.53±0.49%), higher PWV (1858±97.3cm/s：1665±109.2cm/s), higher serum glucagon (194.2±34.8pg/ml：117.0±37.1pg/ml), higher free cortisol of urine (53.8±12.8μg/day：34.8±7.1μg/day), and higher metanephrin of urine (0.162±0.031mg/day：0.076±0.029mg/day). Non-dipper type blood pressure change in ABPM was detected 8 among 9 participants with hypoglycemia (88.9%), 4 among 11 participants (36.4%) without hypoglycemia. Multiplex logistic-regression analysis revealed that the event of hypoglycemia is the independent factor of non-dipper type blood pressure change. Conclusions: Among insulin-treated type 2 diabetic patients with CKD, the events of hypoglycemia were frequently detected, and can associate with the organ derangements through the medium of non-dipper type blood pressure change.

Keywords: chronic kidney disease, hypoglycemia, non-dipper type blood pressure change, diabetic patients

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Authors: Ahmadi, Iriansyah, Raihana Yahman

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The giant freshwater prawn (Macrobrachium rosenbergii de Man, 1879) is a valuable species for fisheries and aquaculture, especially in Southeast Asia, including Indonesia due to their high market demand and potential for export. The growing demand for prawns is straining the sustainability of the Banjar Regency fishery. To ensure the long-term sustainability and economic viability of the prawn fishing in this region, it is imperative to implement evidence-based management practices. This requires comprehensive data on the Catch per Unit Effort (CPUE), Maximum Sustainable Yield (MSY) and the current rate of prawn resource exploitation. it analyzed five years of prawn catch data (2019-2023) obtained from South Kalimantan Marine and Fisheries Services. Fishing gears (e.g. hook & line and cast net) were first standardized with Fishing Power Index, and then calculated effort and MSY. The intercept (a) and the slope (b) values of regression curve were used to estimate the catch-maximum sustainable yield (CMSY) and optimal fishing effort (Fopt) levels within the framework of the Surplus Production Model. The estimated rates of resource utilization were then compared to the criteria of The National Commission of Marine Fish Stock Assessment. The findings showed that the CPUE value peaked in 2019 at 33.48 kg/trip, while the lowest value observed in 2022 at 5.12 kg/trip. The CMSY value was estimated to be 17,396 kg/year, corresponding to the Fopt level of 1,636 trips/year. The highest utilization rate was 56.90% recorded in 2020, while the lowest rate was observed in 2021 at 46.16%. The annual utilization rates were classified as “medium”, suggesting that increasing fishing effort by 45% could potentially maximize prawn catches at an optimum level. These findings provide a baseline for sustainable fisheries management in the region.

Keywords: giant prawns, CPUE, fishing power index, sustainable potential, utilization rate

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Authors: Zohreh Bayat, Dariush Minai-Tehrani

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Pseudomonas aeruginosa is a Gram-negative, rode shape and aerobic bacterium that has shown to be resistance to many antibiotics. This resistance makes the bacterium very harmful in some diseases. It can also generate diseases in any part of the gastrointestinal tract from oropharynx to rectum. P. aeruginosa has become an important cause of infection, especially in patients with compromised host defense mechanisms. One of the most important reasons that make P. aeruginosa an emerging opportunistic pathogen in patients is its ability to use various compounds as carbon sources. Lipase is an enzyme that catalyzes the hydrolysis of lipids. Most lipases act at a specific position on the glycerol backbone of lipid substrate. Some lipases are expressed and secreted by pathogenic organisms during the infection. Muscarinic antagonist used as an antispasmodic and in urinary incontinence. The drug has little effect on glandular secretion or the cardiovascular system. It does have some local anesthetic properties and is used in gastrointestinal, biliary, and urinary tract spasms. Aim: In this study the inhibitory effect of a muscarinic antagonist on lipase of P. aeruginosa was investigated. Methods: P. aeruginosa was cultured in minimal salt medium with 1% olive oil as carbon source. The cells were harvested and the supernatant, which contained lipase, was used for enzyme assay. Results: Our results showed that the drug can inhibit P. aeruginosa lipase by competitive manner. In the presence of different concentrations of the drug, the Vmax (2 mmol/min/mg protein) of enzyme did not change, while the Km raised by increasing the drug concentration. The Ki (inhibition constant) and IC50 (the half maximal inhibitory concentration) value of drug was estimated to be about 30 uM and 60 uM which determined that the drug binds to enzyme with high affinity. Maximum activity of the enzyme was observed at pH 8 in the absence and presence of muscarinic antagonist, respectively. The maximum activity of lipase was observed at 600C and the enzyme became inactive at 900C. Conclusion: The muscarinic antagonist drug could inhibit lipase of P. aeruginosa and changed the kinetic parameters of the enzyme. The drug binded to enzyme with high affinity and did not chang the optimum pH of the enzyme. Temperature did not affect the binding of drug to musmuscarinic antagonist.

Keywords: Pseudomonas aeruginosa, drug, enzyme, inhibition

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Authors: Neslihan Taskale Karatug, Mustafa Akcelik

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Some literature data show that misL protein play a role on host immune response formed against Salmonella Typhimurium. The aim of the present study is to learn the role of the protein in S. Typhimurium pathogenicity. To describe certain functions of the protein, primarily recombinant misL protein was produced and purified. PCR was performed using a primer set targeted to passenger domain of the misL gene on S. Typhimurium LT2 genome. Amplicon and pet28a vector were enzymatically cleaved with EcoRI and NheI. The digested DNA materials were purified with High Pure PCR Product Purification Kit. The ligation reaction was achieved with the pure products. After preparation of competent Escherichia coli Dh5α, ligation mix was transformed into the cell by electroporation. To confirm the existence of insert gene, recombinant plasmid DNA of Dh5α was isolated with high pure plasmid DNA kit. Proved the correctness of recombinant plasmid was electroporated to BL21. The cell was induced by IPTG. After induction, the presence of recombinant protein was checked by SDS-PAGE. The recombinant misL protein was purified using HisPur Ni-NTA spin colon. The pure protein was shown by SDS-PAGE and western blot immünoassay. The concentration of the protein was measured BCA Protein Assay kit. In the wake of ligation with digested products (2 kb misL and 5.4 kb pet28a) visualised on gel size of the band was about 7.4 kb and was named as pNT01. The pNT01 recombinant plasmid was transformed into Dh5α and colonies were chosen in selective medium. Plasmid DNA isolation from them was carried out. PCR was achieved on the pNT01 to check misL and 2 kb band was observed on the agarose gel. After electroporation of the plasmid and induction of the cell, 68 kDa misL protein was seen. Subsequent to the purification of the protein, only a band was observed on SDS-PAGE. Association of the pure protein with anti-his antibody was verified by the western blot assay. The concentration of the pure misL protein was determined as 345 μg/mL. Production of polyclonal antibody will be achieved by using the obtained pure recombinant misL protein as next step. The role of the protein will come out on the immune system together some assays.

Keywords: cloning, Escherichia coli, recombinant protein purification, Salmonella Typhimurium

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Authors: Apichaya Aneksampant, Xuefei Tu, Masami Fukushima, Mitsuo Yamamoto

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The restoration of seaweed beds recovery has been developed using a fertilization technique for supplying dissolved iron to barren coastal areas. The fertilizer is composed of iron oxides as a source of iron and compost as humic substance (HS) source, which can serve as chelator of iron to stabilize the dissolved species under oxic seawater condition. However, elution mechanisms of iron from iron oxide surfaces have not sufficiently elucidated. In particular, roles of microbial activities in the elution of iron from the fertilizer are not sufficiently understood. In the present study, a fertilizer (iron oxide/compost = 1/1, v/v) was incubated in a water tank at Mashike coast, Hokkaido Japan. Microorganisms in the 6-month fertilizer were isolated and identified as Exiguobacterium oxidotolerans sp. (T-2-2). The identified bacteria were inoculated to perform iron elution test in a postgate B medium, prepared in artificial seawater. Hematite was used as a model iron oxide and anthraquinone-2,7-disolfonate (AQDS) as a model for HSs. The elution test performed in presence and absence of bacteria inoculation. ICP-AES was used to analyze total iron and a colorimetric technique using ferrozine employed for the determination of ferrous ion. During the incubation period, sample contained hematite and T-2-2 in both presence and absence of AQDS continuously showed the iron elution and reached at the highest concentration after 9 days of incubation and then slightly decrease to stabilize within 20 days. Comparison to the sample without T-2-2, trace amount of iron was observed, suggesting that iron elution to seawater can be attributed to bacterial activities. The levels of total organic carbon (TOC) in the culture solution with hematite decreased. This may be to the adsorption of organic compound, AQDS, to hematite surfaces. The decrease in UV-vis absorption of AQDS in the culture solution also support the results of TOC that AQDS was adsorbed to hematite surfaces. AQDS can enhance the iron elution, while the adsorption of organic matter suppresses the iron elution from hematite.

Keywords: anthraquinone-2, 7-disolfonate, barren ground, E.oxidotolerans sp., hematite, humic substances, iron elution

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Authors: A. Rezaei, M. Huisman, W. Van Paepegem

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Atomic interactions in molecular systems are mainly studied by particle mechanics. Nevertheless, researches have also put on considerable effort to simulate them using continuum methods. In early 2000, simple equivalent finite element models have been developed to study the mechanical properties of carbon nanotubes and graphene in composite materials. Afterward, many researchers have employed similar structural simulation approaches to obtain mechanical properties of nanostructured materials, to simplify interface behavior of fiber-reinforced composites, and to simulate defects in carbon nanotubes or graphene sheets, etc. These structural approaches, however, are limited to small deformations due to complicated local rotational coordinates. This article proposes a method for the finite element simulation of molecular mechanics. For ease in addressing the approach, here it is called Structural Finite Element Molecular Modeling (SFEMM). SFEMM method improves the available structural approaches for large deformations, without using any rotational degrees of freedom. Moreover, the method simulates molecular conformation, which is a big advantage over the previous approaches. Technically, this method uses nonlinear multipoint constraints to simulate kinematics of the atomic multibody interactions. Only truss elements are employed, and the bond potentials are implemented through constitutive material models. Because the equilibrium bond- length, bond angles, and bond-torsion potential energies are intrinsic material parameters, the model is independent of initial strains or stresses. In this paper, the SFEMM method has been implemented in ABAQUS finite element software. The constraints and material behaviors are modeled through two Fortran subroutines. The method is verified for the bond-stretch, bond-angle and bond-torsion of carbon atoms. Furthermore, the capability of the method in the conformation simulation of molecular structures is demonstrated via a case study of a graphene sheet. Briefly, SFEMM builds up a framework that offers more flexible features over the conventional molecular finite element models, serving the structural relaxation modeling and large deformations without incorporating local rotational degrees of freedom. Potentially, the method is a big step towards comprehensive molecular modeling with finite element technique, and thereby concurrently coupling an atomistic domain to a solid continuum domain within a single finite element platform.

Keywords: finite element, large deformation, molecular mechanics, structural method

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Authors: Anne Y. Faxer, Ellen Olausson, Jens Hagman, Ana Magazinius, Jenny J. Stier, Tommy Fransson, Oscar Enerback

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While electric vehicles (both battery electric vehicles and plug-in hybrids) have been on the market for around 6 years, they are still far from mainstream and the knowledge of them is still low among the public. This is likely one of the reasons that Sweden, having one of the highest penetrations of electric vehicles in Europe, still has a long way to go in reaching a fossil free vehicle fleet. Car dealerships are an important medium that connects consumers to vehicles, but somehow, their role in introducing electric vehicles has not yet been thoroughly studied. Research from other domains shows that salespeople can affect customer decisions in their choice of products. The aim of this study is to explore the role of car dealerships when it comes to promoting electric vehicles. The long-term goal is to understand how they could be a key in the effort of achieving a mass introduction of electric vehicles in Sweden. By emulating the customer’s experience, this study investigates the interaction between car salespeople and customers, particularly examining whether they present electric vehicles as viable options. Covert participatory observations were conducted for data collection from four different brands at in total twelve car dealers. The observers worked in pairs and played the role of a customer with needs that could be matched by an electric vehicle. The data was summarized in observation protocols and analyzed using thematic coding. The result shows that only one of twelve salespeople offered an electric vehicle as the first option. When environmental factors were brought up by the observers, the salespeople followed up with lower fuel consumption internal combustion engine vehicles rather than suggesting an electric vehicle. All salespeople possessed at least basic knowledge about electric vehicles but their interest of selling them were low in most cases. One of the reasons could be that the price of electric vehicles is usually higher. This could be inferred from the finding that salespeople tend to have a strong focus on price and economy in their dialogues with customers, regardless which type of car they were selling. In conclusion, the study suggests that car salespeople have the potential to help the market to achieve mass introduction of electric vehicles; however, their potential needs to be exploited further. To encourage salespeople to prioritize electric vehicles in the sales process, right incentives need to be in place.

Keywords: car dealerships, covert participatory observation, customer perspective , electric vehicle, market penetration

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Authors: Abdul Murad Zainal Abidin, Azahar Mohd, Nor Idayu Arifin, Siti Nor Azila Khalid, Mohd Julzaha Zahari Mohamad Yusof

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A thermoelectric cooler (TEC) is an electronic component that uses ‘peltier’ effect to create a temperature difference by transferring heat between two electrical junctions of two different types of materials. TEC can also be used for heating by reversing the electric current flow and even power generation. A heat flow meter (HFM) is an equipment for measuring thermal conductivity of building materials. During the test, water is used as heat transfer medium to cool the HFM. The existing re-circulating cooler in the market is very costly, and the alternative is to use piped tap water to extract heat from HFM. However, the tap water temperature is insufficiently low to enable heat transfer to take place. The operating temperature for isothermal plates in the HFM is 40°C with the range of ±0.02°C. When the temperature exceeds the operating range, the HFM stops working, and the test cannot be conducted. The aim of the research is to develop a low-cost but energy-efficient TEC prototype that enables heat transfer without compromising the function of the HFM. The objectives of the research are a) to identify potential of TEC as a cooling device by evaluating its cooling rate and b) to determine the amount of water savings using TEC compared to normal tap water. Four (4) peltier sets were used, with two (2) sets used as pre-cooler. The cooling water is re-circulated from the reservoir into HFM using a water pump. The thermal conductivity readings, the water flow rate, and the power consumption were measured while the HFM was operating. The measured data has shown decrease in average cooling temperature difference (ΔTave) of 2.42°C and average cooling rate of 0.031°C/min. The water savings accrued from using the TEC is projected to be 8,332.8 litres/year with the application of water re-circulation. The results suggest the prototype has achieved required objectives. Further research will include comparing the cooling rate of TEC prototype against conventional tap water and to optimize its design and performance in terms of size and portability. The possible application of the prototype could also be expanded to portable storage for medicine and beverages.

Keywords: energy efficiency, thermoelectric cooling, pre-cooling device, heat flow meter, sustainable technology, thermal conductivity

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Authors: T. Yasmin, M. A. Farrelly, B. C. Rogers

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Urban water governance in developing countries faces numerous challenges arising from uncontrolled urban population expansion, water pollution, greater economic push and more recently, climate change impact while undergoing transitioning towards a sustainable system. Sustainability transition requires developing adaptive capacities of the socio-ecological and socio-technical system to be able to deal with complexity. Adaptive capacities deliver strategies to connect individuals, organizations, agencies and institutions at multiple levels for dealing with such complexity. Understanding the level of adaptive capacities for sustainability transformation thus has gained significant research attention within developed countries, much less so in developing countries. Filling this gap, this article develops a conceptual framework for analysing the level of adaptive capacities (if any) within a developing context. This framework then applied to the chronological development of urban water governance strategies in Bangladesh for almost two centuries. The chronological analysis of governance interventions has revealed that crisis (public health, food and natural hazards) became the opportunities and thus opened the windows for experimentation and learning to occur as a deviation from traditional practices. Self-organization and networks thus created the platform for development or disruptions to occur for creating change. Leadership (internal or external) is important for nurturing and upscaling theses development or disruptions towards guiding policy vision and targets as well as championing ground implementation. In the case of Bangladesh, the leadership from the international and national aid organizations and targets have always lead the development whereas more often social capital tools (trust, power relations, cultural norms) act as disruptions. Historically, this has been evident in the development pathways of urban water governance in Bangladesh. Overall this research has shown some level of adaptive capacities is growing for sustainable urban growth in big cities, nevertheless unclear regarding the growth in medium and small cities context.

Keywords: adaptive capacity, Bangladesh, sustainability transformation, water governance

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Authors: Adel A. Ghobbar, Varun Raman

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The Corrective maintenance of components and systems is a problem plaguing almost every industry in the world today. Train operators’ and the maintenance repair and overhaul subsidiary of the Dutch railway company is also facing this problem. A considerable portion of the maintenance activities carried out by the company are unscheduled. This, in turn, severely stresses and stretches the workforce and resources available. One possible solution is to have a robust preventive maintenance plan. The other possible solution is to plan maintenance based on real-time data obtained from sensor-based ‘Health and Usage Monitoring Systems.’ The former has been investigated in this paper. The preventive maintenance model developed for train operator will subsequently be extended, to tackle the unscheduled maintenance problem also affecting the aerospace industry. The extension of the model to the aerospace sector will be dealt with in the second part of the research, and it would, in turn, validate the soundness of the model developed. Thus, there are distinct areas that will be addressed in this paper, including the mathematical modelling of preventive maintenance and optimization based on cost and system availability. The results of this research will help an organization to choose the right maintenance strategy, allowing it to save considerable sums of money as opposed to overspending under the guise of maintaining high asset availability. The concept of delay time modelling was used to address the practical problem of unscheduled maintenance in this paper. The delay time modelling can be used to help with support planning for a given asset. The model was run using MATLAB, and the results are shown that the ideal inspection intervals computed using the extended from a minimal cost perspective were 29 days, and from a minimum downtime, perspective was 14 days. Risk matrix integration was constructed to represent the risk in terms of the probability of a fault leading to breakdown maintenance and its consequences in terms of maintenance cost. Thus, the choice of an optimal inspection interval of 29 days, resulted in a cost of approximately 50 Euros and the corresponding value of b(T) was 0.011. These values ensure that the risk associated with component X being maintained at an inspection interval of 29 days is more than acceptable. Thus, a switch in maintenance frequency from 90 days to 29 days would be optimal from the point of view of cost, downtime and risk.

Keywords: delay time modelling, unscheduled maintenance, reliability, maintainability, availability

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Authors: Murad Ali, Shoji Arai, Mohamed Khedr, Mukhtar Nasher, Shawki Nasr

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The Wadi Bayhan area of southeastern Yemen is about 60 km NW of Al-Bayda city in the Al-Bayda uplift terrane at the southeast margin of the Arabian-Nubian Shield. Intrusion of alkali gabbro into carbonate rocks apparently produced an 8m to 10 m thick reaction zone at the contact. This had been identified as nepheline pyroxenite. We have observed this to be mineralogically zoned with calc-silicate assemblages (e.g. pyroxene, calcite, spinel, garnet and melilite). The presence of melilite implies a skarn. The sinuous embayed pyroxenite-skarn contact, the presence of skarn minerals in pyroxenite, and textural evidence for growth of calc-silicate skarn by replacement of both carbonate rocks and solid pyroxenite indicate that reaction involved assimilation of carbonate wall rock by magma and loss of Al and Si to the skarn. Textural relationships between minerals provide evidence for a metasomatic development of the skarn at the expense of the pyroxenite. This process, related to the circulation of fluids equilibrated with carbonates, is responsible for those pyroxenite-spinel (± calcite) skarns. The uneven modal distribution of euhedral pyroxenite and enveloping nepheline in pyroxenite, the restricted occurrence of alkali gabbro as dikes in pyroxenite and skarn and the leucocratic matrix of pyroxenite suggest that pyroxenite represents an accumulation of titanaugite cemented by an alkali-rich residual magma and that alkali gabbro represents a part of the residual contaminated magma that was squeezed out of the pyroxene crystal mush. Carbonate assimilation is modeled by reaction of calcite and magmatic plagioclase, which results in resorption of plagioclase, growth of pyroxene enriched in Ca, Fe, Ti, and Al, and solution of nepheline in residual contaminated magma. The composition of nepheline pyroxenite evolved by addition of Ca from dissolved carbonate rocks, loss of Al and Si to skarn, and local segregation of solid pyroxene and alkali gabbro magma. The predominance of pyroxenite among contaminated rocks and their restriction to a large zone along the intrusive contact provide little evidence for the genesis of a significant volume of alkaline magmatic surroundings by carbonate assimilation.

Keywords: Yemen, Wadi Bayhan, skarn, pyroxenite, carbonatite, metasomatic

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Authors: Israel Ropo Orimoloye, Johanes A. Belle, Olusola Adeyemi, Olusola O. Ololade

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With more than 100,000 orbits during the past 20 years, Terra has significantly improved our knowledge of the Earth's climate and its implications on societies and ecosystems of human activity and natural disasters, including drought events. With Terra instrument's performance and the free distribution of its products, this study utilised Terra MOD13Q1 satellite data to assess drought disaster events and its spatiotemporal patterns over the Free State Province of South Africa between 2001 and 2019 for summer, autumn, winter, and spring seasons. The study also used high-resolution downscaled climate change projections under three representative concentration pathways (RCP). Three future periods comprising the short (the 2030s), medium (2040s), and long term (2050s) compared to the current period are analysed to understand the potential magnitude of projected climate change-related drought. The study revealed that the year 2001 and 2016 witnessed extreme drought conditions where the drought index is between 0 and 20% across the entire province during summer, while the year 2003, 2004, 2007, and 2015 observed severe drought conditions across the region with variation from one part to the another. The result shows that from -24.5 to -25.5 latitude, the area witnessed a decrease in precipitation (80 to 120mm) across the time slice and an increase in the latitude -26° to -28° S for summer seasons, which is more prominent in the year 2041 to 2050. This study emphasizes the strong spatio-environmental impacts within the province and highlights the associated factors that characterise high drought stress risk, especially on the environment and ecosystems. This study contributes to a disaster risk framework to identify areas for specific research and adaptation activities on drought disaster risk and for environmental planning in the study area, which is characterised by both rural and urban contexts, to address climate change-related drought impacts.

Keywords: remote sensing, drought disaster, climate scenario, assessment

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Authors: Chijindu D. Mgbemere

Abstract:

Mass killing also known as genocide is the systematic killing of people from national, ethnic, or religious group, or an attempt to do so. The act has been there before 1948, when it was officially recognized for what it is. From then, the world has continued to witness genocide in diverse forms- negating different measures by the United Nations and its agencies to curb it. So far, all the studies and documentations on this subject are biased in favor of radio and the print. This paper therefore extended the interrogation of genocide, drumming its devastating effects, using the film medium; and in doing so devised innovative and pragmatic approach to genocide scholarship. It further centered attention on the factors and impacts of genocide, with a view to determine how effective film can be in such a study. The study is anchored on Bateson’s Framing Theory. Four films- Hotel Rwanda, Half of a Yellow Sun, Attack on Darfur, and sarafina, were analyzed, based on background, factors/causes, impacts, and development of genocide, via Content Analysis. The study discovered that: as other continents strive towards peace, acts of genocide are on the increase in African. Bloodletting stereotypes give Africa negative image in the global society. Difficult political frameworks, the trauma of postcolonial state, aggravated by ethnic and religious intolerance, and limited access to resources are responsible for high cases of genocide in Africa. The media, international communities, and peace agencies often abet other than prevent genocide or mass killings in Africa. High human casualty and displacement, children soldering, looting, hunger, rape, sex-slavery and abuse, mental and psychosomatic stress disorders are some of the impacts of genocide. Genocidaires are either condemned or killed. Grievances can be vented using civil resistance, negotiation, adjudication, arbitration, and mediation. The cinema is an effective means of studying and documenting genocide. Africans must factor the image laundering of their continent into consideration. Punishment of genocidaires without an attempt to de-radicalize them is counterproductive.

Keywords: African film, genocide, framing theory, mass murder

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