Search results for: internal forces

Authors: Aynura Valiyeva, Basil John Thomas

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Intra-firm communication is critical for building synergy amongst internal business units of a firm, where employees from various functional departments and ranks incorporate their decision-making, understanding of organizational objectives, as well as common norms and culture for better organizational effectiveness. This study builds on and assesses a framework of the causes and consequences of effective communication in business interactions between customer and supplier firms, and the path for efficient communication within a firm. The proposed study’s structural equation modeling (SEM) analysis based on 352 sample responses collected from firm representatives at different job positions ranging from marketing to logistics operations, reveals that, in the frame of reference of intra-organizational communication, organization characteristics and shared values, top management support and style of leadership, as well as information technology, are all significantly related to communication effectiveness. Furthermore, the frequency and variety of interactions enhance the outcome of communication, that improves a company’s performance. The results reveal that cultural factors are significantly related to communication effectiveness, as well as the shared beliefs and goals. In terms of organizational factors, leadership style, top management support and information technology are significant determinants of effective communication. Among the contextual factors, interaction frequency and diversity are found to be priority factors. This study also tests the relationship between supplier and supplier firm performance in the context of communication effectiveness, and finds that they are closely related, when trust and commitment is built between business partners. When firms do business in other multicultural contexts, language and shared values with destination country must be considered significant elements of communication process.

Keywords: business performance, intra-firm communication, inter-firm communication, structural equation modeling

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Authors: David Whitehouse

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Some of the strengths of online teaching include flexibility, creativity, and comprehensiveness. A challenge can be motivation. How can an instructor repeating the same lessons over and over, day in and day out, year after year, maintain motivation? Enthusiasm? Does motivating the student and creating enthusiasm in class build the same things inside the instructor? The answers lie in the adoption of what I label EUQ—The Empathy and Understanding Quotient. In the online environment, students who are adults have many demands on their time: civilian careers, families (spouse, children, older parents), and sometimes even military service. Empathetic responses on the part of the instructor will lead to open and honest communication on the part of the student, which will lead to understanding on the part of the instructor and a rise in motivation in both parties. Understanding the demands can inform an instructor’s relationship with the student throughout the temporal parameters of classwork. In practicing EUQ, instructors can build motivation in their students and find internal motivation in an enhanced classroom dynamic. The presentation will look at what motivates a student to accomplish more than the minimum required and how that can lead to excellent results for an instructor’s own motivation. Through direct experience of having students give high marks on post-class surveys and via direct messaging, the presentation will focus on how applying EUQ in granting extra time, searching for intent while grading, communicating with students via Quick Notes, responses in Forums, comments in Assignments, and comments in grading areas - - - how applying these things infuses enthusiasm and energy in the instructor which drive creativity in teaching. Three primary ways of communicating with students will be given as examples. The positive response and negative response each for a Forum, an Assignment, and a Message will be explored. If there is time, participants will be invited to craft their own EUQ responses in a role playing exercise involving two common classroom scenarios—late work and plagiarism.

Keywords: education, instruction, motivation, online, teaching

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Authors: Mohamed Faslan

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This research examines the impact of the politicization of the fishing dispute on India-Sri Lanka relations, particularly the influence of internal and party politics. The maritime border is clearly demarcated between India and Sri Lanka. India and Sri Lanka signed bilateral agreements on maritime boundaries in 1974 and 1976 respectively. They signed the United Nations Law of the Sea- III as well. Despite this, fishing disputes persist between the two nations. Tamil Nadu politics is closely linked with Sri Lankan Tamil issues and Tamil Nadu has been playing a significant role in Indo-Lanka relations. This is due to the fact that many Indian trawlers involved in fishing activities in Sri Lankan waters are from Tamil Nadu. The Government of Tamil Nadu is also very concerned about the issue of fishing in Sri Lankan waters. During the ethnic war, Sri Lankan fishermen were restricted on fishing activities in the Northern sea by the Sri Lankan Government and Liberation Tigers of Tamil Elam (LTTE). This created a vacuum in the Northern sea of Sri Lanka, and Indian trawlers filled the vacuum with the support of the LTTE. After the end of the war, Northern fishermen of Sri Lanka recommenced their fishing activities and realized that the Tamil Nadu trawlers had scooped their fishing resources. The Northern fishermen started to protest the invasion of Indian trawlers and pushed the Sri Lankan Government to stop the Indian trawlers. When Sri Lanka arrested Indian fishermen and confiscated their fishing boats, the Tamil Nadu Government used this as an opportunity to accuse Sri Lanka as having a Sinhalese government, to express feelings of hatred towards Sri Lanka due to the ethnic war against Tamils and tried to increase the voting bank by selling Tamil feelings. Thus, this research finds that Tamil Nadu does not associate this fishing dispute with Tamils in Sri Lanka but with the Sinhalese despite the status quo. This research has covered the Northern fishermen and stakeholders of Sri Lanka and could not do any field research in India due to visa restrictions. However, the researcher tries to balance the gap by referring to secondary sources and a few interviews with Indian scholars.

Keywords: Indo Lanka relations, fishing dispute, maritime border, Tamil Nadu & Sri Lankan waters

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Authors: B. Vijay Antony Raj, Umarani Gunasekaran, R. Thiru Kumara Raja Vallaban

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Fibrous autoclaved aerated concrete (FAAC) is concrete containing fibrous material in it which helps to increase its structural integrity when compared to that of convention autoclaved aerated concrete (CAAC). These short discrete fibers are uniformly distributed and randomly oriented, which enhances the bond strength within the aerated concrete matrix. Conventional red-clay bricks create larger impact to the environment due to red soil depletion and it also consumes large amount to time for construction. Whereas, AAC are larger in size, lighter in weight and it is environmentally friendly in nature and hence it is a viable replacement for red-clay bricks. Internal micro cracks and corner cracks are the only disadvantages of conventional autoclaved aerated concrete, to resolve this particular issue it is preferable to make use of fibers in it.These fibers are bonded together within the matrix and they induce the aerated concrete to withstand considerable stresses, especially during the post cracking stage. Hence, FAAC has the capability of enhancing the mechanical properties and energy absorption capacity of CAAC. In this research work, individual fibers like glass, nylon, polyester and polypropylene are used they generally reduce the brittle fracture of AAC.To study the fibre’s surface topography and composition, SEM analysis is performed and then to determine the composition of a specimen as a whole as well as the composition of individual components EDAX mapping is carried out and then an experimental approach was performed to determine the effect of hybrid (multiple) fibres at various dosage (0.5%, 1%, 1.5%) and curing temperature of 180-2000 C is maintained to determine the mechanical properties of autoclaved aerated concrete. As an analytical part, the outcome experimental results is compared with fuzzy logic using MATLAB.

Keywords: fiberous AAC, crack control, energy absorption, mechanical properies, SEM, EDAX, MATLAB

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Authors: Weiliang Wen, Xinyu Guo, Ying Zhang, Jianjun Du, Boxiang Xiao

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Reconstructing and analyzing three-dimensional (3D) models from situ measured data is important for a number of researches and applications in plant science, including plant phenotyping, functional-structural plant modeling (FSPM), plant germplasm resources protection, agricultural technology popularization. It has many scales like cell, tissue, organ, plant and canopy from micro to macroscopic. The techniques currently used for data capture, feature analysis, and 3D reconstruction are quite different of different scales. In this context, morphological data acquisition, 3D analysis and modeling of plants on different scales are introduced systematically. The commonly used data capture equipment for these multiscale is introduced. Then hot issues and difficulties of different scales are described respectively. Some examples are also given, such as Micron-scale phenotyping quantification and 3D microstructure reconstruction of vascular bundles within maize stalks based on micro-CT scanning, 3D reconstruction of leaf surfaces and feature extraction from point cloud acquired by using 3D handheld scanner, plant modeling by combining parameter driven 3D organ templates. Several application examples by using the 3D models and analysis results of plants are also introduced. A 3D maize canopy was constructed, and light distribution was simulated within the canopy, which was used for the designation of ideal plant type. A grape tree model was constructed from 3D digital and point cloud data, which was used for the production of science content of 11th international conference on grapevine breeding and genetics. By using the tissue models of plants, a Google glass was used to look around visually inside the plant to understand the internal structure of plants. With the development of information technology, 3D data acquisition, and data processing techniques will play a greater role in plant science.

Keywords: plant, three dimensional modeling, multi-scale, plant phenotyping, three dimensional data acquisition

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Authors: Ulugbek Azimov, Nearchos Stylianidis, Nobuyuki Kawahara, Eiji Tomita

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A chemical kinetics and computational fluid-dynamics (CFD) analysis was performed to evaluate the combustion of syngas derived from biomass and coke-oven solid feedstock in a micro-pilot ignited supercharged dual-fuel engine under lean conditions. For this analysis, a new reduced syngas chemical kinetics mechanism was constructed and validated by comparing the ignition delay and laminar flame speed data with those obtained from experiments and other detail chemical kinetics mechanisms available in the literature. The reaction sensitivity analysis was conducted for ignition delay at elevated pressures in order to identify important chemical reactions that govern the combustion process. The chemical kinetics of NOx formation was analyzed for H2/CO/CO2/CH4 syngas mixtures by using counter flow burner and premixed laminar flame speed reactor models. The new mechanism showed a very good agreement with experimental measurements and accurately reproduced the effect of pressure, temperature and equivalence ratio on NOx formation. In order to identify the species important for NOx formation, a sensitivity analysis was conducted for pressures 4 bar, 10 bar and 16 bar and preheat temperature 300 K. The results show that the NOx formation is driven mostly by hydrogen based species while other species, such as N2, CO2 and CH4, have also important effects on combustion. Finally, the new mechanism was used in a multidimensional CFD simulation to predict the combustion of syngas in a micro-pilot-ignited supercharged dual-fuel engine and results were compared with experiments. The mechanism showed the closest prediction of the in-cylinder pressure and the rate of heat release (ROHR).

Keywords: syngas, chemical kinetics mechanism, internal combustion engine, NOx formation

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Authors: Luciana P. Mazur, Tatiana A. Pozdniakova, Rui A. R. Boaventura, Vitor J. P. Vilar

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The electroplating industry requires a lot of process water, which generates a large volume of wastewater loaded with heavy metals. Two different wastewaters were collected in a company’s wastewater treatment plant, one after the use of zinc in the metal plating process and the other after the use of chromium. The main characteristics of the Zn(II) and Cr(VI) wastewaters are: pH = 6.7/5.9; chemical oxygen demand = 55/<5 mg/L; sodium, potassium, magnesium and calcium ions concentrations of 326/28, 4/28, 11/7 and 46/37 mg/L, respectively; zinc(II) = 11 mg/L and Cr(VI) = 39 mg/L. Batch studies showed that L. hyperborea can be established as a natural cation exchanger for heavy metals uptake mainly due to the presence of negatively charged functional groups in the surface of the biomass. Beyond that, L. hyperborea can be used as a natural electron donor for hexavalent chromium reduction to trivalent chromium at acidic medium through the oxidation of the biomass, and Cr(III) can be further bound to the negatively charged functional groups. The uptake capacity of Cr(III) by the oxidized biomass after Cr(VI) reduction was higher than by the algae in its original form. This can be attributed to the oxidation of the biomass during Cr(VI) reduction, turning other active sites available for Cr(III) binding. The brown macroalgae Laminaria hyperborea was packed in a fixed-bed column in order to evaluate the feasibility of the system for the continuous treatment of the two galvanization wastewaters. The column, with an internal diameter of 4.8 cm, was packed with 59 g of algae up to a bed height of 27 cm. The operation strategy adopted for the treatment of the two wastewaters consisted in: i) treatment of the Zn(II) wastewater in the first sorption cycle; ii) desorption of pre-loaded Zn(II) using an 1.0 M HCl solution; iii) treatment of the Cr(VI) wastewater, taking advantage of the acidic conditions of the column after the desorption cycle, for the reduction of the Cr(VI) to Cr(III), in the presence of the electrons resulting from the biomass oxidation. This cycle ends when all the oxidizing groups are used.

Keywords: biosorption, brown marine macroalgae, zinc, chromium

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Authors: V. Suganya, V. Balasuriya

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The functioning of Micro and Small Scale (MSS) businesses in the northern part of Sri Lanka was vulnerable due to three decades of internal conflict and the subsequent post-war economic openings has resulted new market prospects for MSS businesses. MSS businesses survive and operate with limited resources and struggle to access finance, raw material, markets, and technology. This study attempts to identify the manner in which entrepreneurial orientation puts into practice by the business operators to overcome these business challenges. Business operators in the traditional food processing sector are taken for this study as this sub-sector of the food industry is developing at a rapid pace. A review of the literature was done to recognize the concepts of entrepreneurial orientation, defining MMS businesses and the manner in which business performance is measured. Direct interview method supported by a structured questionnaire is used to collect data from 80 respondents; based on a fixed interval random sampling technique. This study reveals that more than half of the business operators have opted to commence their business ventures as a result of identifying a market opportunity. 41 per cent of the business operators are highly entrepreneurial oriented in a scale of 1 to 5. Entrepreneurial orientation shows significant relationship and strongly correlated with business performance. Pro-activeness, innovativeness and competitive aggressiveness shows a significant relationship with business performance while risk taking is negative and autonomy is not significantly related to business performance. It is evident that entrepreneurial oriented business practices contribute to better business performance even though 70 per cent prefer the ideas/views of the support agencies than the stakeholders when making business decisions. It is recommended that appropriate training should be introduced to develop entrepreneurial skills focusing to improve business networks so that new business opportunities and innovative business practices are identified.

Keywords: Micro and Small Scale (MMS) businesses, entrepreneurial orientation (EO), food processing, business operators

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Authors: Babak Nemat

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Background and Purpose: Non-alcoholic fatty liver is one of the most common liver disorders, which, as the most important cause of death from liver disease, has unpleasant consequences and complications. The aim of this study was to investigate the effect of an educational intervention based on a health belief model to prevent non-alcoholic fatty liver among women. Materials and Methods: This experimental study was performed among 110 women referring to comprehensive health service centers in Malayer City, west of Iran, in 2023. Using the available sampling method, 110 participants were divided into experimental and control groups. The data collection tool included demographic characteristics and a questionnaire based on the health belief model. In the experimental group, three one-hour training sessions were conducted in the form of pamphlets, lectures, and group discussions. Data were analyzed using SPSS software version 21, by correlation tests, paired t-tests, and independent t-tests. Results: The mean age of participants was 38.07±6.28 years, and most of the participants were middle-aged, married, housewives with academic education, middle-income, and overweight. After the educational intervention, the mean scores of the constructs include perceived sensitivity (p=0.01), perceived severity (p=0.01), perceived benefits (p=0.01), guidance for internal (p=0.01), and external action (p=0.01), and perceived self-efficacy (p=0.01) in the experimental group were significantly higher than the control group. The score of perceived barriers in the experimental group decreased after training. The perceived obstacles score in the test group decreased after the training (15.2 ± 3.9 v.s 11.2 ± 3.3, (p<0.01). Conclusion: The findings of the study showed that the design and implementation of educational programs based on the constructs of the health belief model can be effective in preventing women from developing higher levels of non-alcoholic fatty liver.

Keywords: non-alcoholic fatty liver, health belief model, education, women

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Authors: S. Lemoussu, J. C. Chaudemar, R. A. Vingerhoeds

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The aeronautics sector is currently living an unprecedented growth largely due to innovative projects. In several cases, such innovative developments are being carried out by Small and Medium sized-Enterprises (SMEs). For instance, in Europe, a handful of SMEs are leading projects like airships, large civil drones, or flying cars. These SMEs have all limited resources, must make strategic decisions, take considerable financial risks and in the same time must take into account the constraints of safety, cost, time and performance as any commercial organization in this industry. Moreover, today, no international regulations fully exist for the development and certification of this kind of projects. The absence of such a precise and sufficiently detailed regulatory framework requires a very close contact with regulatory instances. But, SMEs do not always have sufficient resources and internal knowledge to handle this complexity and to discuss these issues. This poses additional challenges for those SMEs that have system integration responsibilities and that must provide all the necessary means of compliance to demonstrate their ability to design, produce, and operate airships with the expected level of safety and reliability. The final objective of our research is thus to provide a methodological framework supporting SMEs in their development taking into account recent innovation and institutional rules of the sector. We aim to provide a contribution to the problematic by developing a specific Model-Based Systems Engineering (MBSE) approach. Airspace regulation, aeronautics standards and international norms on systems engineering are taken on board to be formalized in a set of models. This paper presents the on-going research project combining Systems Engineering and Project Management process modeling and taking into account the metamodeling problematic.

Keywords: aeronautics, certification, process modeling, project management, SME, systems engineering

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Authors: Chetan Gupta, Ramesh Gupta

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Unmanned aerial vehicles, of all sizes, are prime targets of the wing morphing concept as their lightweight structures demand high aerodynamic stability while traversing unsteady atmospheric conditions. In this research study, a hybrid morphing technology is developed to aid the trailing edge of the aircraft wing to alter its camber as a monolithic element rather than functioning as conventional appendages like flaps. Kinematic tailoring, actuation techniques involving shape memory alloys (SMA), piezoelectrics – individually fall short of providing a simplistic solution to the conundrum of morphing aircraft wings. On the other hand, the feature of negligible hysteresis while actuating using compliant mechanisms has shown higher levels of applicability and deliverability in morphing wings of even large aircrafts. This research paper delves into designing a wing section model with a periodic, multi-stable compliant structure requiring lower orders of topological optimization. The design is sub-divided into three smaller domains with external hyperelastic connections to achieve deflections ranging from -15° to +15° at the trailing edge of the wing. To facilitate this functioning, a hybrid actuation system by combining the larger bandwidth feature of piezoelectric macro-fibre composites and relatively higher work densities of shape memory alloy wires are used. Finite element analysis is applied to optimize piezoelectric actuation of the internal compliant structure. A coupled fluid-surface interaction analysis is conducted on the wing section during morphing to study the development of the velocity boundary layer at low Reynold’s numbers of airflow.

Keywords: compliant mechanism, hybrid morphing, piezoelectrics, shape memory alloys

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Authors: David B. Tsuanyo, Didier Aussel, Yao Azoumah, Pierre Neveu

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An innovative concept called “Flexy-Energy”is developing at 2iE. This concept aims to produce electricity at lower cost by smartly mix different available energies sources in accordance to the load profile of the region. With a higher solar irradiation and due to the fact that Diesel generator are massively used in sub-Saharan rural areas, PV/Diesel hybrid systems could be a good application of this concept and a good solution to electrify this region, provided they are reliable, cost effective and economically attractive to investors. Presentation of the developed approach is the aims of this paper. The PV/Diesel hybrid system designed consists to produce electricity and/or heat from a coupling between Diesel gensets and PV panels without batteries storage, while ensuring the substitution of gasoil by bio-fuels available in the area where the system will be installed. The optimal design of this system is based on his technical performances; the Life Cycle Cost (LCC) and Levelized Cost of Energy are developed and use as economic criteria. The Net Present Value (NPV), the internal rate of return (IRR) and the discounted payback (DPB) are also evaluated according to dual electricity pricing (in sunny and unsunny hours). The PV/Diesel hybrid system obtained is compared to the standalone Diesel gensets. The approach carried out in this paper has been applied to Siby village in Mali (Latitude 12 ° 23'N 8 ° 20'W) with 295 kWh as daily demand. This approach provides optimal physical characteristics (size of the components, number of component) and dynamical characteristics in real time (number of Diesel generator on, their load rate, fuel specific consumptions, and PV penetration rate) of the system. The system obtained is slightly cost effective; but could be improved with optimized tariffing strategies.

Keywords: investments criteria, optimization, PV hybrid, sizing, rural electrification

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Authors: Edward Shizha

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Citizenship is not only political, but it is also a socio-cultural expectation that naturalized immigrants desire for. However, the outcomes of citizenship desirability are determined by forces outside the individual’s control based on legislation and laws that are designed at the macro and exosystemic levels by politicians and policy makers. These laws are then applied to determine the status (permanency or temporariness) of citizenship for immigrants and refugees, but the same laws do not apply to non-immigrant citizens who attain it by birth. While theoretically, citizenship has generally been considered an irrevocable legal status and the highest and most secure legal status one can hold in a state, it is not inviolate for immigrants. While Article 8 of the United Nations Convention on the Reduction of Statelessness provides grounds for revocation of citizenship obtained by immigrants and refugees in host countries, nation-states have their own laws tied to the convention that provide grounds for revocation. Ever since the 9/11 attacks in the USA, there has been a rise in conditional citizenship and the state’s withdrawal of citizenship through revocation laws that denaturalize citizens who end up not merely losing their citizenship but also the right to reside in the country of immigration. Because immigrants can be perceived as a security threat, the securitization of citizenship and the legislative changes have been adopted to specifically allow greater discretionary power in stripping people of their citizenship.The paper ‘Do We Really Belong Here?’ Transnationalism and the Temporality of Naturalized Citizenship examines literature on the temporality of naturalized citizenship and questions whether citizenship, for newcomers (immigrants and refugees), is a protected human right or a privilege. The paper argues that citizenship in a host country is a well sought-after status by newcomers. The question is whether their citizenship, if granted, has a permanent or temporary status and whether it is treated in the same way as that of non-immigrant citizens. The paper further argues that, despite citizenship having generally been considered an irrevocable status in most Western countries, in practice, if not in law, for immigrants and refugees, citizenship comes with strings attached because of policies and laws that control naturalized citizenship. These laws can be used to denationalize naturalized citizens through revocations for those stigmatized as ‘undesirables’ who are threatened with deportation. Whereas non-immigrant citizens (those who attain it by birth) have absolute right to their citizenship, this is seldom the case for immigrants.This paper takes a multidisciplinary approach using Urie Bronfenbrenner’s ecological systems theory, the macrosystem and exo-system, to examine and review literature on the temporality of naturalized citizenship and questions whether citizenship is a protected right or a privilege for immigrants. The paper challenges the human rights violation of citizenship revocation and argues for equality of treatment for all citizens despite how they acquired their citizenship. The fragility of naturalized citizenship undermines the basic rights and securities that citizenship status can provide to the person as an inclusive practice in a diverse society.

Keywords: citizenship, citizenship revocation, dual citizenship, human rights, naturalization, naturalized citizenship

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Authors: S. Raja, K. M. Parammasivam, V. Aghilesh

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Fluid-structure interaction is a crucial consideration in the design of many engineering systems such as flight vehicles and bridges. Aircraft lifting surfaces and turbine blades can fail due to oscillations caused by fluid-structure interaction. Hence, it is focussed to study the fluid-structure interaction in the present research. First, the effect of free vibration over the panel is studied. It is well known that the deformation of a panel and flow induced forces affects one another. The selected panel has a span 300mm, chord 300mm and thickness 2 mm. The project is to study, the effect of cross-sectional area and the stiffener location is carried out for the same panel. The stiffener spacing is varied along both the chordwise and span-wise direction. Then for that optimal location the ideal stiffener length is identified. The effect of stiffener cross-section shapes (T, I, Hat, Z) over flutter velocity has been conducted. The flutter velocities of the selected panel with two rectangular stiffeners of cantilever configuration are estimated using MSC NASTRAN software package. As the flow passes over the panel, deformation takes place which further changes the flow structure over it. With increasing velocity, the deformation goes on increasing, but the stiffness of the system tries to dampen the excitation and maintain equilibrium. But beyond a critical velocity, the system damping suddenly becomes ineffective, so it loses its equilibrium. This estimated in NASTRAN using PK method. The first 10 modal frequencies of a simple panel and stiffened panel are estimated numerically and are validated with open literature. A grid independence study is also carried out and the modal frequency values remain the same for element lengths less than 20 mm. The current investigation concludes that the span-wise stiffener placement is more effective than the chord-wise placement. The maximum flutter velocity achieved for chord-wise placement is 204 m/s while for a span-wise arrangement it is augmented to 963 m/s for the stiffeners location of ¼ and ¾ of the chord from the panel edge (50% of chord from either side of the mid-chord line). The flutter velocity is directly proportional to the stiffener cross-sectional area. A significant increment in flutter velocity from 218m/s to 1024m/s is observed for the stiffener lengths varying from 50% to 60% of the span. The maximum flutter velocity above Mach 3 is achieved. It is also observed that for a stiffened panel, the full effect of stiffener can be achieved only when the stiffener end is clamped. Stiffeners with Z cross section incremented the flutter velocity from 142m/s (Panel with no stiffener) to 328 m/s, which is 2.3 times that of simple panel.

Keywords: stiffener placement, stiffener cross-sectional area, stiffener length, stiffener cross sectional area shape

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Authors: David Martínez Rico, Juan Pablo Farid Cuéllar Martínez

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After more than half a century that the first treaty of European cooperation was created, the final result of a difficult and long historical process, which is the current European Union, is facing economical and social challenges. The barriers of policies differences and national sovereignties seem to be being defeated in the last and present decades. However, the last crisis of 2008 brought back problems as xenophobia and nationalism. In this ambit of identity, European Union has made many efforts to reinforce a European identity and leave behind the radical nationalisms which generated World Wars. Nevertheless, these social problems are increasing and becoming more present in the life of many Europeans. Even, in the last Euro Parliamentarian Elections of the present year, 2014, the extreme right parties, in favor of xenophobic and anti European ideals, got more seats and are increasing their presence in Euro Parliament. This essay approaches to this controversial topic of European identity. Taking as start point the nationalist divisions that are causing internal divergences in Europe, the authors of this research study the role and contributions of the Memorials of the fallen soldiers and heroes of World Wars, present in many cities as Amsterdam, Brussels and Paris, to the impossibility to reach an European identity, it means that Europeans feel first part of Europe in place to feel first part of a nation. The objective of this essay is to reaffirm the thesis that establishes that the European Union won´t reach the longed supranational identity with just with the current strategies, because yet there are many cultural elements in its member states societies which exalt the heroes and soldiers of the past wars, increasing nationalism feelings. Besides, in it are promoted some interesting ideas that could change the course in this quest of a European social identity.

Keywords: identity, memorials, European identity, nationalism, proposals

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Authors: Yuanyuan Zhang, Yujuan Zheng, Giuseppina Barutello, Sumako Kameishi, Kungchun Chiu, Katharina Hennig, Martial Balland, Federica Cavallo, Lars Holmgren

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Angiogenesis describes that new blood vessels migrate from pre-existing ones to form 3D lumenized structure and remodeling. During directional migration toward the gradient of pro-angiogenic factors, the endothelial cells, especially the tip cells need filopodia to sense the environment and exert the pulling force. Of particular interest are the integrin proteins, which play an essential role in focal adhesion in the connection between migrating cells and extracellular matrix (ECM). Understanding how these biomechanical complexes orchestrate intrinsic and extrinsic forces is important for our understanding of the underlying mechanisms driving angiogenesis. We have previously identified Angiomotin (Amot), a member of Amot scaffold protein family, as a promoter for endothelial cell migration in vitro and zebrafish models. Hence, we established inducible endothelial-specific Amot knock-out mice to study normal retinal angiogenesis as well as tumor angiogenesis. We found that the migration ratio of the blood vessel network to the edge was significantly decreased in Amotec- retinas at postnatal day 6 (P6). While almost all the Amot defect tip cells lost migration advantages at P7. In consistence with the dramatic morphology defect of tip cells, there was a non-autonomous defect in astrocytes, as well as the disorganized fibronectin expression pattern correspondingly in migration front. Furthermore, the growth of transplanted LLC tumor was inhibited in Amot knockout mice due to fewer vasculature involved. By using MMTV-PyMT transgenic mouse model, there was a significantly longer period before tumors arised when Amot was specifically knocked out in blood vessels. In vitro evidence showed that Amot binded to beta-actin, Integrin beta 1 (ITGB1), Fibronectin, FAK, Vinculin, major focal adhesion molecules, and ITGB1 and stress fibers were distinctly induced by Amot transfection. Via traction force microscopy, the total energy (force indicater) was found significantly decreased in Amot knockdown cells. Taken together, we propose that Amot is a novel partner of the ITGB1/Fibronectin protein complex at focal adhesion and required for exerting force transition between endothelial cell and extracellular matrix.

Keywords: angiogenesis, angiomotin, endothelial cell migration, focal adhesion, integrin beta 1

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Authors: Carlos Teodoro, Oscar Bautista

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In this work, we analyze theoretically the mass transport in a time-periodic electroosmotic flow through a parallel flat plate microchannel under different periodic functions of the applied external electric field. The microchannel connects two reservoirs having different constant concentrations of an electro-neutral solute, and the zeta potential of the microchannel walls are assumed to be uniform. The governing equations that allow determining the mass transport in the microchannel are given by the Poisson-Boltzmann equation, the modified Navier-Stokes equations, where the Debye-Hückel approximation is considered (the zeta potential is less than 25 mV), and the species conservation. These equations are nondimensionalized and four dimensionless parameters appear which control the mass transport phenomenon. In this sense, these parameters are an angular Reynolds, the Schmidt and the Péclet numbers, and an electrokinetic parameter representing the ratio of the half-height of the microchannel to the Debye length. To solve the mathematical model, first, the electric potential is determined from the Poisson-Boltzmann equation, which allows determining the electric force for various periodic functions of the external electric field expressed as Fourier series. In particular, three different excitation wave forms of the external electric field are assumed, a) sawteeth, b) step, and c) a periodic irregular functions. The periodic electric forces are substituted in the modified Navier-Stokes equations, and the hydrodynamic field is derived for each case of the electric force. From the obtained velocity fields, the species conservation equation is solved and the concentration fields are found. Numerical calculations were done by considering several binary systems where two dilute species are transported in the presence of a carrier. It is observed that there are different angular frequencies of the imposed external electric signal where the total mass transport of each species is the same, independently of the molecular diffusion coefficient. These frequencies are called crossover frequencies and are obtained graphically at the intersection when the total mass transport is plotted against the imposed frequency. The crossover frequencies are different depending on the Schmidt number, the electrokinetic parameter, the angular Reynolds number, and on the type of signal of the external electric field. It is demonstrated that the mass transport through the microchannel is strongly dependent on the modulation frequency of the applied particular alternating electric field. Possible extensions of the analysis to more complicated pulsation profiles are also outlined.

Keywords: electroosmotic flow, mass transport, oscillatory flow, species separation

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Authors: A. Nour Eddine, D. Chalet, L. Aixala, P. Chessé, X. Faure, N. Hatat

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Thermal power technology such as the TEG (Thermo-Electric Generator) arouses significant attention worldwide for waste heat recovery. Despite the potential benefits of marine application due to the permanent heat sink from sea water, no significant studies on this application were to be found. In this study, a test rig has been designed and built to test the performance of the TEG on engine operating points. The TEG device is built from commercially available materials for the sake of possible economical application. Two types of commercial TEM (thermo electric module) have been studied separately on the test rig. The engine data were extracted from a commercial Diesel engine since it shares the same principle in terms of engine efficiency and exhaust with the marine Diesel engine. An open circuit water cooling system is used to replicate the sea water cold source. The characterization tests showed that the silicium-germanium alloys TEM proved a remarkable reliability on all engine operating points, with no significant deterioration of performance even under sever variation in the hot source conditions. The performance of the bismuth-telluride alloys was 100% better than the first type of TEM but it showed a deterioration in power generation when the air temperature exceeds 300 °C. The temperature distribution on the heat exchange surfaces revealed no useful combination of these two types of TEM with this tube length, since the surface temperature difference between both ends is no more than 10 °C. This study exposed the perspective of use of TEG technology for marine engine exhaust heat recovery. Although the results suggested non-sufficient power generation from the low cost commercial TEM used, it provides valuable information about TEG device optimization, including the design of heat exchanger and the types of thermo-electric materials.

Keywords: internal combustion engine application, Seebeck, thermo-electricity, waste heat recovery

Procedia PDF Downloads 227

Authors: Petra Hofmann, Dana Koniel, Jussi Luukkanen, Walter Nieminen, Lea Hannola, Ilkka Donoghue

Abstract:

The Covid-19 pandemic forced people to isolate and become physically less connected. The pandemic has not only reshaped people’s behaviours and needs but also accelerated digital transformation (DT). DT of cities has become an imperative with the outlook of converting them into smart cities in the future. Embedding digital infrastructure and smart city initiatives as part of normal design, construction, and operation of cities provides a unique opportunity to improve the connection between people. The Internet of Things (IoT) is an emerging technology and one of the drivers in DT. It has disrupted many industries by introducing different services and business models, and IoT solutions are being applied in multiple fields, including smart cities. As IoT and data are fundamentally linked together, IoT solutions can only create value if the data generated by the IoT devices is analysed properly. Extracting relevant conclusions and actionable insights by using established techniques, data analytics contributes significantly to the growth and success of IoT applications and investments. Companies must grasp DT and be prepared to redesign their offerings and business models to remain competitive in today’s marketplace. As there are many IoT solutions available today, the amount of data is tremendous. The challenge for companies is to understand what solutions to focus on and how to prioritise and which data to differentiate from the competition. This paper explains how IoT and data analytics can impact competitive advantage and how companies should approach IoT and data analytics to translate them into concrete offerings and solutions in the smart city context. The study was carried out as a qualitative, literature-based research. A case study is provided to validate the preservation of company’s competitive advantage through smart city solutions. The results of the research contribution provide insights into the different factors and considerations related to creating competitive advantage through IoT and data analytics deployment in the smart city context. Furthermore, this paper proposes a framework that merges the factors and considerations with examples of offerings and solutions in smart cities. The data collected through IoT devices, and the intelligent use of it, can create competitive advantage to companies operating in smart city business. Companies should take into consideration the five forces of competition that shape industries and pay attention to the technological, organisational, and external contexts which define factors for consideration of competitive advantages in the field of IoT and data analytics. Companies that can utilise these key assets in their businesses will most likely conquer the markets and have a strong foothold in the smart city business.

Keywords: data analytics, smart cities, competitive advantage, internet of things

Procedia PDF Downloads 111

Authors: Abdur Raheem, Ado Yakub

Abstract:

Urban violence in the form of ethnic and religious conflicts have been on the increase in many African cities in the recent years of which most of them are the result of intense and bitter competition for political power, the control of limited economic, social and environmental resources. In Nigeria, the emergence of the Boko Haram insurgency in most parts of the north eastern parts have ignited violence, bloodshed, refuge exodus and internal migration. Not only do the persistent attacks of the sect create widespread insecurity and fear, it has also stifled normal processes of trade and investments most especially real property investment which is acclaimed to accelerate the economic cycle, thus the need to evolve strategies for an improved property market in such areas. This paper, therefore, examines the impact of these social crisis on effective and efficient utilization of real properties as a resource towards the development of the economy, using a descriptive analysis approach where particular emphasis was based on trends in residential housing values; volume of estimated property transactions and real estate investment decisions by affected individuals. Findings indicate that social crisis in the affected areas have been a clog on the wheels of property development and investment as properties worth hundreds of millions have been destroyed thereby having great impact on property values. Based on these findings, recommendations were made to include the need to strategically continue investing in property during such times, the need for Nigerian government to establish an active conflict monitoring and management unit for prompt response, encourage community and neighbourhood policing to ameliorate security challenges in Nigeria.

Keywords: social crisis, property market, economy, resources, north-eastern Nigeria

Procedia PDF Downloads 305

Authors: Krasimira Georgieva, Yordan Denev

Abstract:

Many of thermosetting resins have application only in filled state, reinforced with different mineral fillers. The co-filling of polymers with mineral filler and gases creates a possibility for production of polymer composites materials with low density. This processing leads to forming of new materials – gas-filled plastics (polymer foams). The properties of these materials are determined mainly by the shape and size of internal structural elements (pores). The interactions on the phase boundaries have influence on the materials properties too. In the present work, the gas-filled urea-formaldehyde resins were reinforced by waste phosphogypsum. The waste phosphogypsum (CaSO₄.2H₂O) is a solid by-product in wet phosphoric acid production processes. The values of the interactions polymer-filler were increased by using two modifying agents: polyvinyl acetate for polymer matrix and sodium metasilicate for filler. Technological methods for gas-filling and recipes of urea-formaldehyde based materials with apparent density 20-120 kg/m³ were developed. The heat conductivity of the samples is between 0.024 and 0.029 W/m^oK. Tensile analyses were carried out at 10 and 50% deformation and show values 0.01-0.14 MPa and 0.01-0.09 MPa, respectively. The apparent density of obtained materials is between 20 and 92 kg/m³. The changes in the tensile properties and density of these materials according to sodium metasilicate content were studied too. The mechanism of phosphogypsum adsorption modification was studied using methods of FT-IR spectroscopy. The structure of the gas-filled urea-formaldehyde resins was described by results of electron scanning microscopy at three different magnification ratios – x50, x150 and x 500. The aim of present work is to study the possibility of the usage of phosphogypsum as mineral filler for urea-formaldehyde resins and development of a technology for the production of gas-filled reinforced polymer composite materials. The structure and the properties of obtained composite materials are suitable for thermal and sound insulation applications.

Keywords: urea formaldehyde resins, gas-filled thermostes, phosphogypsum, mechanical properties

Procedia PDF Downloads 92

Authors: Sayyed Benyamin Alavi, Giovanni Cerri, Leila Chennaoui, Ambra Giovannelli, Stefano Mazzoni

Abstract:

Primary energy consumption and emissions of pollutants (including CO2) sustainability call to search methodologies to lower power absorption for unit of a given product. Cool production plants based on vapour compression are widely used for many applications: air conditioning, food conservation, domestic refrigerators and freezers, special industrial processes, etc. In the field of cool production, the amount of Yearly Consumed Primary Energy is enormous, thus, saving some percentage of it, leads to big worldwide impact in the energy consumption and related energy sustainability. Among various techniques to reduce power required by a Vapour Compression Cool Production Plant (VCCPP), the technique based on Power Regeneration by means of Internal Direct Cycle (IDC) will be considered in this paper. Power produced by IDC reduces power need for unit of produced Cool Power by the VCCPP. The paper contains basic concepts that lead to develop IDCs and the proposed options to use the IDC Power. Among various selections for using turbo machines, Best Economically Available Technologies (BEATs) have been explored. Based on vehicle engine turbochargers, they have been taken into consideration for this application. According to BEAT Database and similarity rules, the best turbo machine selection leads to the minimum nominal power required by VCCPP Main Compressor. Results obtained installing the prototype in “ad hoc” designed test bench will be discussed and compared with the expected performance. Forecasts for the upgrading VCCPP, various applications will be given and discussed. 4-6% saving is expected for air conditioning cooling plants and 15-22% is expected for cryogenic plants.

Keywords: Refrigeration Plant, Vapour Pressure Amplifier, Compressor, Expander, Turbine, Turbomachinery Selection, Power Saving

Procedia PDF Downloads 414

Authors: Yue Feng, Chun-jiang Wang, Zhi-long Huang

Abstract:

The study of the sedimentary environment of Mesoproterozoic marine deposits in North China has attracted special attention in recent years. It is not clear that the sedimentary environment and the cause of formation of the sandstone strip and its internal carbonate cements and pyrite in the Mesoproterozoic Chuanlinggou Formation in North China. In this study, drilling core samples in North China were identified by microscopy, and their petrological characteristics such as mineral composition and structure were identified. The geochemical data of carbon and oxygen isotopes, total organic carbon (TOC) contents and total sulfur (TS) contents were obtained by processing and analyzing the samples. The samples are mainly quartz particles with low compositional maturity, combined with low value of TOC, it shows that the sedimentary environment of the sandy clastic is a sandy littoral sedimentary environment with relative strong hydrodynamic force, and then the sandstone strip in black shale are formed by the deposition of gravity flow. Analysis of TS values reflect sandstone bands formed in hypoxic environments. The carbonate cements and the pyrite in the sandstone belt are authigenic. The carbon isotope values of authigenic carbonate cements are negatively biased in comparison with the carbonate isotope of carbonate rocks in the same period, but it is more biased than the carbon isotopic values of anaerobic oxidation of methane (AOM) genetic carbonate rocks. Authigenic pyrite may be mainly due to the formation of HS- by the action of bacterial sulfate reduction (BSR) and Fe²⁺, their causes are in contact. This indicates that authigenic carbonate cements are mainly carbonate precipitates formed but are significantly affected by the effects of AOM. Summary, the sedimentary environment of the sandstone zone in the Chuanlinggou Formation in the North China is a shallow sea facies with iron rich and anoxic.

Keywords: sandstone strip, sedimentary environment, authigenic carbonate cements, authigenic pyrite, The Chuanlinggou group, North China

Procedia PDF Downloads 130

Authors: V. Manjunath, C. V. Chandrashekara

Abstract:

Ecosystem authority calls for the use of lubricants with less effect on the nature in terms of exhaust emission, while engine user demands more mileage per liter of fuel without any compromise on engine durability. From this viewpoint, engine manufacturers require the optimum combination of materials and lubricant additive package to minimize friction and wear in the engine components like piston, crankshaft and valve train etc. The demands are placed for requirements to operate at higher speeds, loads, temperature and for extended replacement intervals of engine oil. Besides, it is necessary to accurately predict the lubricant life or the replacement interval to prevent lubrication and valve-train components failure. Experimental tribology evaluation of new engine oils requires large amount of time and energy. Hence low cost bench test is necessary for industries and original equipment manufacturing companies (OEM) to study the performance of lubricants. The present work outlines the procedure for the design and development of a valve train wear rig (MCR) to simulate the ASTMD-6891 and to develop new engine test for Indian automobile sector to evaluate lubricants for Indian automobile market. In order to improve the lubrication between cam and follower of internal combustion engine, the influence of materials or oils viscosity and additives on the friction and wear characteristics are examined with test rig by increasing the contact load at two different revolution speed. From the experimentation following results are made obvious. Temperature, Torque, speed and wear plots are used to validate the data obtained from the newly developed multi-cam cam rig (MCR) with follower against a cast iron camshaft. Camshaft lobe wear is measured at seven different locations on cam profile. Tribofilm formed using 5W-30 oil is evaluated and correlated with the standard test results.

Keywords: ASTMD-6891, multi-cam rig (MCR), 5W-30, cam-profile

Procedia PDF Downloads 162

Authors: Anjali Uday, Yuting Wang, Andres Alfonso Pena Olare

Abstract:

The Discrete Element Method is a promising approach to modeling microscopic behaviors of granular materials. The quality of the simulations however depends on the model parameters utilized. The present study focuses on calibration and validation of the discrete element parameters for Cuxhaven sand based on the experimental data from triaxial and oedometer tests. A sensitivity analysis was conducted during the sample preparation stage and the shear stage of the triaxial tests. The influence of parameters like rolling resistance, inter-particle friction coefficient, confining pressure and effective modulus were investigated on the void ratio of the sample generated. During the shear stage, the effect of parameters like inter-particle friction coefficient, effective modulus, rolling resistance friction coefficient and normal-to-shear stiffness ratio are examined. The calibration of the parameters is carried out such that the simulations reproduce the macro mechanical characteristics like dilation angle, peak stress, and stiffness. The above-mentioned calibrated parameters are then validated by simulating an oedometer test on the sand. The oedometer test results are in good agreement with experiments, which proves the suitability of the calibrated parameters. In the next step, the calibrated and validated model parameters are applied to forecast the micromechanical behavior including the evolution of contact force chains, buckling of columns of particles, observation of non-coaxiality, and sample inhomogeneity during a simple shear test. The evolution of contact force chains vividly shows the distribution, and alignment of strong contact forces. The changes in coordination number are in good agreement with the volumetric strain exhibited during the simple shear test. The vertical inhomogeneity of void ratios is documented throughout the shearing phase, which shows looser structures in the top and bottom layers. Buckling of columns is not observed due to the small rolling resistance coefficient adopted for simulations. The non-coaxiality of principal stress and strain rate is also well captured. Thus the micromechanical behaviors are well described using the calibrated and validated material parameters.

Keywords: discrete element model, parameter calibration, triaxial test, oedometer test, simple shear test

Procedia PDF Downloads 105

Authors: Ravinder Kaur

Abstract:

Introduction Global cerebrovascular reactivity (CVR) mapping is a promising clinical assessment for stress-testing the brain using physiological challenges, such as CO₂, to elicit changes in perfusion. It enables real-time assessment of cerebrovascular integrity and health. Conventional imaging approaches solely use steady-state parameters, like cerebral blood flow (CBF), to evaluate the integrity of the resting parenchyma and can erroneously show a healthy brain at rest, despite the underlying pathogenesis in the presence of cerebrovascular disease. Conversely, coupling CO₂ inhalation with phase-contrast MRI neuroimaging interrogates the capacity of the vasculature to respond to changes under stress. It shows promise in providing prognostic value as a novel health marker to measure neurovascular function in disease and to detect early brain vasculature dysfunction. Objective This exploratory study was established to:(a) quantify the CBF response to CO₂ in hypocapnia and hypercapnia,(b) evaluate disparities in CVR between internal carotid (ICA) and vertebral artery (VA), and (c) assess sex-specific variation in CVR. Methodology Phase-contrast MRI was employed to measure the cerebrovascular reactivity to CO₂ (±10 mmHg). The respiratory interventions were presented using the prospectively end-tidal targeting RespirActTM Gen3 system. Post-processing and statistical analysis were conducted. Results In 9 young, healthy subjects, the CBF increased from hypocapnia to hypercapnia in all vessels (4.21±0.76 to 7.20±1.83 mL/sec in ICA, 1.36±0.55 to 2.33±1.31 mL/sec in VA, p < 0.05). The CVR was quantitatively higher in ICA than VA (slope of linear regression: 0.23 vs. 0.07 mL/sec/mmHg, p < 0.05). No statistically significant effect was observed in CVR between male and female (0.25 vs 0.20 mL/sec/mmHg in ICA, 0.09 vs 0.11 mL/sec/mmHg in VA, p > 0.05). Conclusions The principal finding in this investigation validated the modulation of CBF by CO₂. Moreover, it has indicated that regional heterogeneity in hemodynamic response exists in the brain. This study provides scope to standardize the quantification of CVR prior to its clinical translation.

Keywords: cerebrovascular disease, neuroimaging, phase contrast MRI, cerebrovascular reactivity, carbon dioxide

Procedia PDF Downloads 131

Authors: Petra Hofmann, Dana Koniel, Jussi Luukkanen, Walter Nieminen, Lea Hannola, Ilkka Donoghue

Abstract:

The Covid-19 pandemic forced people to isolate and become physically less connected. The pandemic hasnot only reshaped people’s behaviours and needs but also accelerated digital transformation (DT). DT of cities has become an imperative with the outlook of converting them into smart cities in the future. Embedding digital infrastructure and smart city initiatives as part of the normal design, construction, and operation of cities provides a unique opportunity to improve connection between people. Internet of Things (IoT) is an emerging technology and one of the drivers in DT. It has disrupted many industries by introducing different services and business models, and IoT solutions are being applied in multiple fields, including smart cities. As IoT and data are fundamentally linked together, IoT solutions can only create value if the data generated by the IoT devices is analysed properly. Extracting relevant conclusions and actionable insights by using established techniques, data analytics contributes significantly to the growth and success of IoT applications and investments. Companies must grasp DT and be prepared to redesign their offerings and business models to remain competitive in today’s marketplace. As there are many IoT solutions available today, the amount of data is tremendous. The challenge for companies is to understand what solutions to focus on and how to prioritise and which data to differentiate from the competition. This paper explains how IoT and data analytics can impact competitive advantage and how companies should approach IoT and data analytics to translate them into concrete offerings and solutions in the smart city context. The study was carried out as a qualitative, literature-based research. A case study is provided to validate the preservation of company’s competitive advantage through smart city solutions. The results of the researchcontribution provide insights into the different factors and considerations related to creating competitive advantage through IoT and data analytics deployment in the smart city context. Furthermore, this paper proposes a framework that merges the factors and considerations with examples of offerings and solutions in smart cities. The data collected through IoT devices, and the intelligent use of it, can create a competitive advantage to companies operating in smart city business. Companies should take into consideration the five forces of competition that shape industries and pay attention to the technological, organisational, and external contexts which define factors for consideration of competitive advantages in the field of IoT and data analytics. Companies that can utilise these key assets in their businesses will most likely conquer the markets and have a strong foothold in the smart city business.

Keywords: internet of things, data analytics, smart cities, competitive advantage

Procedia PDF Downloads 82

Authors: Livhuwani Muthelo

Abstract:

The health and safety of the miners in the South African mining industry are guided by the regulations and standards which are anticipated to promote a healthy work environment and fatalities. It is of utmost importance for the miners to comply with these regulations/standards to protect themselves from potential occupational health and safety risks, accidents, and fatalities. The purpose of this study was to develop and validate strategies to enhance compliance with the Health and safety standards within the mining industries of Limpopo province in South Africa. A mixed-method exploratory sequential research design was adopted. The population consisted of 5350 miners. Purposive sampling was used to select the participants in the qualitative strand and stratified random sampling in the quantitative strand. Semi-structured interviews were conducted among the occupational health nurse practitioners and the health and safety team. Thematic analysis was used to generate an understanding of the interviews. In the quantitative strand, a survey was conducted using a self-administered questionnaire. Data were analysed using SPSS version 26.0. A descriptive statistical test was used in the analysis of data including frequencies, means, and standard deviation. Cronbach's alpha test was used to measure internal consistency. The integrated results revealed that there are diverse experiences related to health and safety standards compliance among the mineworkers. The main findings were challenges related to leadership compliance and also related to the cost of maintaining safety, Miner's behavior-related challenges; the impact of non-compliance on the overall health of the miners was also described, the conflict between production and safety. Health and safety compliance is not just mere compliance with regulations and standards but a culture that warrants the miners and organization to take responsibility for their behavior and actions towards health and safety. Thus taking responsibility for your well-being and other miners.

Keywords: perceptions, compliance, health and safety, legislation, standards, miners

Procedia PDF Downloads 85

Authors: Tatiana A. Pozdniakova, Maria A. P. Cechinel, Luciana P. Mazur, Rui A. R. Boaventura, Vitor J. P. Vilar.

Abstract:

Two brown macroalgae, Laminaria hyperborea and Pelvetia canaliculata, were employed as natural cation exchangers in a fixed-bed column for Zn(II) removal from a galvanization wastewater. The column (4.8 cm internal diameter) was packed with 30-59 g of previously hydrated algae up to a bed height of 17-27 cm. The wastewater or eluent was percolated using a peristaltic pump at a flow rate of 10 mL/min. The effluent used in each experiment presented similar characteristics: pH of 6.7, 55 mg/L of chemical oxygen demand and about 300, 44, 186 and 244 mg/L of sodium, calcium, chloride and sulphate ions, respectively. The main difference was nitrate concentration: 20 mg/L for the effluent used with L. hyperborean and 341 mg/L for the effluent used with P. canaliculata. The inlet zinc concentration also differed slightly: 11.2 mg/L for L. hyperborean and 8.9 mg/L for P. canaliculata experiments. The breakthrough time was approximately 22.5 hours for both macroalgae, corresponding to a service capacity of 43 bed volumes. This indicates that 30 g of biomass is able to treat 13.5 L of the galvanization wastewater. The uptake capacities at the saturation point were similar to that obtained in batch studies (unpublished data) for both algae. After column exhaustion, desorption with 0.1 M HNO3 was performed. Desorption using 9 and 8 bed volumes of eluent achieved an efficiency of 100 and 91%, respectively for L. hyperborean and P. canaliculata. After elution with nitric acid, the column was regenerated using different strategies: i) convert all the binding sites in the sodium form, by passing a solution of 0.5 M NaCl, until achieve a final pH of 6.0; ii) passing only tap water in order to increase the solution pH inside the column until pH 3.0, and in this case the second sorption cycle was performed using protonated algae. In the first approach, in order to remove the excess of salt inside the column, distilled water was passed through the column, leading to the algae structure destruction and the column collapsed. Using the second approach, the algae remained intact during three consecutive sorption/desorption cycles without loss of performance.

Keywords: biosorption, zinc, galvanization wastewater, packed-bed column

Procedia PDF Downloads 302

Authors: Soumaya Mrabet, Imen Akkari, Amira Atig, Elhem Ben Jazia

Abstract:

Introduction: Celiac disease (CD) is a chronic autoimmune inflammatory enteropathy caused by gluten. The clinical presentation is very variable. Malabsorption in the MC is responsible for an alteration of the bone metabolism. Our purpose is to study the osteoarticular manifestations related to this condition. Material and methods: It is a retrospective study of 41 cases of CD diagnosed on clinical, immunological, endoscopic and histological arguments, in the Internal Medicine and Gastroenterology Department of Farhat Hached Hospital between September 2005 and January 2016. Results: Osteoarticular manifestations were found in 9 patients (22%) among 41 patients presenting CD. These were 7 women and 2 men with an average age of 35.7 years (25 to 67 years). These manifestations were revelatory of CD in 3 cases. Abdominal pain and diarrhea were present in 6 cases. Inflammatory polyarthralgia of wrists and knees has been reported in 7 patients. Mechanical mono arthralgia was noted in 2 patients. Biological tests revealed microcytic anemia by iron deficiency in 7 cases, hypocalcemia in 5 cases, Hypophosphatemia in 3 cases and elevated alkaline phosphatases in 3 cases. Upper gastrointestinal endoscopy with duodenal biopsy found villous atrophy in all cases. In immunology, Anti-transglutaminase antibodies were positive in all patients, Anti-endomysium in 7 cases. Measurement of bone mineral density (BMD) by biphotonic X-ray absorptiometer with evaluation of the T-score and the Z-score was performed in Twenty patients (48.8%). It was normal in 7 cases (33%) and showed osteopenia in 5 patients (25%) and osteoporosis in 2 patients (10%). All patients were treated with a Gluten-free diet associated with vitamin D and calcium substitution in 5 cases. The evolution was favorable in all cases with reduction of bone pain and normalization of the phosphocalcic balance. Conclusion: The bone impact of CD is frequent but often asymptomatic. Patients with CD should be evaluated by the measurement of bone mineral density and monitored for calcium and vitamin D deficiencies.

Keywords: bone mineral density, celiac disease, osteoarticular manifestations, vitamin D and calcium

Procedia PDF Downloads 311