Search results for: Ming Show Wong

Authors: Merouane Salhi, Toufik Zebbiche, Omar Abada

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When the stagnation pressure of perfect gas increases, the specific heat and their ratio do not remain constant anymore and start to vary with this pressure. The gas does not remain perfect. Its state equation change and it becomes a real gas. In this case, the effects of molecular size and inter molecular attraction forces intervene to correct the state equation. The aim of this work is to show and discuss the effect of stagnation pressure on supersonic thermo dynamical, physical and geometrical flow parameters, to find a general case for real gas. With the assumptions that Berthelot’s state equation accounts for molecular size and inter molecular force effects, expressions are developed for analyzing supersonic flow for thermally and calorically imperfect gas lower than the dissociation molecules threshold. The designs parameters for supersonic nozzle like thrust coefficient depend directly on stagnation parameters of the combustion chamber. The application is for air. A computation of error is made in this case to give a limit of perfect gas model compared to real gas model.

Keywords: supersonic flow, real gas model, Berthelot’s state equation, Simpson’s method, condensation function, stagnation pressure

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Authors: Norah Alshayhan

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Dealing with public problems is one of the struggles that may face the leaders in the public sector. Collaborative leadership is one of the most important approaches in dealing with difficult situations that affect both public, private, and nonprofit organizations. Current literature does not show exactly the extent of utilizing collaborative leadership during the post-COVID-19 world in Saudi Arabia. This study is worth exploring in order to examine collaborative leadership in similar environments. This research will utilize both integrative public leadership and transformational leadership theories to guide the researcher in answering the research question. The researcher utilizes content analysis and reviews government documents, plans, and reports to gain more information about collaborative leadership in Saudi Arabia. The researcher analyzes the data in themes and sub-themes to categorize the data in answering the research question. Leader’s behavior and performance in the public sector will be the focus of this study. Findings from this research will benefit leaders in both public, private, and nonprofit sectors in their leadership during a post-disaster time. Findings from this study support collaborative leadership practices and performance in leading future post-crises/disasters.

Keywords: collaborative leadership, post-COVID-19, Saudi Arabia, performance, skills

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Authors: Alice Petzold, Alexandre Hassanin

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The number of giraffe species has been in focus of interest since the exploration of sub-Saharan Africa by European naturalists during the 18th and 19th centuries, as previous taxonomists, like Geoffroy Saint-Hilaire, Richard Owen or William Edward de Winton, recognized two or three species of Giraffa. For the last decades, giraffes were commonly considered as a single species subdivided into nine subspecies. In this study, we have re-examined available nuclear and mitochondrial data. Our genetic admixture analyses of seven introns support three species: G. camelopardalis (i.e., northern giraffes including reticulated giraffes), G. giraffa (southern giraffe) and G. tippelskirchi (Masai giraffe). However, the nuclear alignments show small variation and our phylogenetic analyses provide high support only for the monophyly of G. camelopardalis. Comparisons with the mitochondrial tree revealed a robust conflict for the position and monophyly of G. giraffa and G. tippelskirchi, which is explained firstly by a mitochondrial introgression from Masai giraffe to southeastern giraffe, and secondly, by gene flow mediated by male dispersal between southern populations (subspecies angolensis and giraffa). We conclude that current data gives only moderate support for three giraffe species and point out that additional nuclear data need to be studied to revise giraffe taxonomy.

Keywords: autosomal markers, Giraffidae, mitochondrial introgression, taxonomy

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Authors: Maciej Kozlowski, Agnieszka Piotrowska-Piatek

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Purpose: This article analyses the most important financial participation programmes (FPP) in Poland to show the relationship between the programmes applied and the socio-economic results of enterprises and assesses the impact of participation on these results and the impact of selected factors on the introduction of FPP. Methodology: The research has been based on a questionnaire answered by senior management of listed Polish companies that had at least one out of three major FPPs in operation, namely share ownership, profit-sharing, or a stock option scheme. Findings: The results of the empirical study conducted indicate the existence of some peculiar relationships. The vast majority of schemes in Polish public companies are aimed at the participation of the management personnel; these programmes are narrow-based (only for management) and rather hermetic, with a high concentration of stocks or shares in the hands of the management. Conclusion: FPPs generally have a positive influence on enterprise functioning. However, the effects are more social than economic (no significant economic improvement after programme implementation). The paper contributes to the debate about financial participation and suggests actions to popularize these programmes on a wider scale.

Keywords: financial participation, profit sharing, stock options, worker attitude, worker ownership

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Authors: J. Gochermann

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German energy market is under historical change. Turning-off the nuclear power plants and intensive subsidization of the renewable energies causes a paradigm change from big central energy production and distribution to more local structures, bringing the energy production near to the consumption. The formerly big energy market with only a few big energy plants and grid operating companies is changing into a disperse market with growing numbers of small and medium size companies (SME) generating new value-added products and services. This change in then energy market, in Germany called the “Energiewende”, inverts also the previous innovation system. Big power plants and large grids required also big operating companies. Innovations in the energy market focused mainly on big projects and complex energy technologies. Innovation in the new energy market structure is much more dispersed. Increasing number of SME is now able to develop energy production and storage technologies, smart technologies to control the grids, and numerous new energy related services. Innovation is now regional distributed, which is a remarkable problem for the old big energy companies. The paper will explain the change in the German energy market and the paradigm change as well as the consequences for the innovation structure in the German energy market. It will show examples how SME participate from this change and how innovation systems, as well for the big companies and for SME, can be adapted.

Keywords: changing energy markets, disperse innovation, new value-added products and services, SME

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Authors: Siham G. Farag

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The main objective of this paper is to provide a new methodology for road safety assessment in Oman through the development of suitable accident prediction models. GLM technique with Poisson or NBR using SAS package was carried out to develop these models. The paper utilized the accidents data of 31 un-signalized T-intersections during three years. Five goodness-of-fit measures were used to assess the overall quality of the developed models. Two types of models were developed separately; the flow-based models including only traffic exposure functions, and the full models containing both exposure functions and other significant geometry and traffic variables. The results show that, traffic exposure functions produced much better fit to the accident data. The most effective geometric variables were major-road mean speed, minor-road 85th percentile speed, major-road lane width, distance to the nearest junction, and right-turn curb radius. The developed models can be used for intersection treatment or upgrading and specify the appropriate design parameters of T- intersections. Finally, the models presented in this thesis reflect the intersection conditions in Oman and could represent the typical conditions in several countries in the middle east area, especially gulf countries.

Keywords: accidents prediction models (APMs), generalized linear model (GLM), T-intersections, Oman

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Authors: Hani M. M. Alothaid, Louise Robson, Richmond Muimo

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This study will investigate cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) dependent calcineurin (Cn), known as protein phosphatase 2 B (PP2B) as well, regulation of chloride ion (Cl⁻) secretion and the release of pro-inflammatory molecules in immune cells such as cytokines. THP-1-derived monocytes, primary human monocytes and the bronchial epithelial cell line (16HBE14o-) were used in this study. The 16HBE14o- cells were chosen as positive control. Hence, to further confirm the expression of cystic fibrosis transmembrane conductance regulator (CFTR), calcium binding protein (S100A10), annexin A2 (AnxA2) and calcineurin A subunit (CnA) in all three cell types, cell lysate was probed against corresponding primary antibodies by immunoblotting. Western blot analyses show the expression of CFTR, AnxA2, CnA and S100A10 in THP-1-derived monocytes and primary human monocytes. In conclusion, CFTR, S100A10, CnA and AnxA2 are expressed in THP-1-derived monocytes and primary human monocytes and regulate Cl⁻ secretion. Also, they may play a role in the pro-inflammatory molecules release. The ongoing work will confirm interaction between these proteins in the cell lines.

Keywords: annexin A2, calcineurin, CFTR, chloride, monocytes, pro-inflammatory molecules, S100A10

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Authors: Nesrine Frifita, Mohamed Gharbi, Kevin Mickus

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Physical methods based on gravity, seismic and seismological data were adopted to clarify the relationship between the distribution of seismicity and the crustal deformations under the chott belts and surrounding regions, in southern atlas of Tunisia. Gafsa and its surrounding were described as a moderate seismic zone, and the fault of Gafsa is one of most seismically active faults in Tunisia in general, and in the southern Atlas in particularly. The present work aims to prove a logical relationship between the distribution of seismicity and deformations which strongly related to thickness and density variations within the basement and sedimentary cover along the study area, through several physical methods; gravity, seismic and seismological data were interpreted to calculate physical propriety of the subsurface rocks, the depth and geometry of active faults and causatives bodies. Findings show that depths variation and mixed thin and thick skinned structural style characterizing the chott belts explain the moderate seismicity in the study area.

Keywords: potential fields, seismicity, Southern Atlas, Tunisia

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Authors: Hassan Youssef Mohamed

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In this paper, we show new wave equations, and by using the equations, we concluded that the strong force and the weak force are not fundamental, but they are quantum effects for electromagnetism. This result is different from the current scientific understanding about strong and weak interactions at all. So, we introduce three evidences for our theory. First, we prove the asymptotic freedom phenomenon in the strong force by using our model. Second, we derive the nuclear shell model as an approximation of our model. Third, we prove that the leptons do not participate in the strong interactions, and we prove the short ranges of weak and strong interactions. So, our model is consistent with the current understanding of physics. Finally, we introduce the electron-positron model as the basic ingredients for protons, neutrons, and all matters, so we can study all particles interactions and nuclear interaction as many-body problems of electrons and positrons. Also, we prove the violation of parity conservation in weak interaction as evidence of our theory in the weak interaction. Also, we calculate the average of the binding energy per nucleon.

Keywords: new wave equations, the strong force, the grand unification theory, hydrogen atom, weak force, the nuclear shell model, the asymptotic freedom, electron-positron model, the violation of parity conservation, the binding energy

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Authors: Hafizul Rasdi

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This study was conducted to find out the perceptions of Islamic Education teachers on the implementation of 21st century learning practices in Kuching, Sarawak. This study uses the field method. Eight respondents were selected based on the interviews and focus group discussions conducted among teachers in four primary school in Kuching, Sarawak. This study is focused to find out the perceptions of Islamic Education teachers on the implementation of 21st century learning as well as the importance of 21st century learning in the subject of Islamic Education. Data were collected using library research, semi-structured interview transcripts and focus group discussions. Data analysis methods used was descriptive analysis. The findings of the study have shown that Islamic Education teachers in primary school in Kuching, Sarawak agreed on the implementation of 21st Century Learning Practices in Islamic Education subject. The finding also show that the application of 21st Century Learning Practices in the subject of Islamic Education can help improve students mastery of the subject.

Keywords: perceptions, Islamic education, 21st century learning practices, teachers

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Authors: Hasneet K. Kalsi, Julie K. Kilgariff

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Introduction: Within dentistry, the process for gaining informed consent has become more complex. To consent for treatment, patients must understand all reasonable treatment options and associated risks and benefits. Consenting is therefore deeply embedded in health literacy. Patients attending for dental consultation are often presented with an array of information and choices, yet studies show patients recall less than half of the information provided immediately after. Appropriate and comprehensible patient information leaflets (PILs) may be useful aid memories. In 2016 the World Health Organisation set improving health literacy as a global priority. Soon after, Scotland’s 2017-2025 Making it Easier: A Health Literacy Action Plan followed. This project involved the review of Restorative PILs used within Dundee Dental Hospital to assess the Content and Readability. Method: The current PIL on Root Canal Treatment (RCT) was created in 2011. This predates the Montgomery vs. NHS Lanarkshire case, a ruling which significantly impacted dental consenting processes, as well as General Dental Council’s (GDC’s) Standards for the Dental Team and Faculty of General Dental Practice’s Good Practice Guidance on Clinical Examination and Record-Keeping. Current evidence-based guidance, including that stipulated by the GDC, was reviewed. A 20-point Essential Content Checklist was designed to conform to best practice guidance for valid consenting processes. The RCT leaflet was scored against this to ascertain if the content was satisfactory. Having ensured the content satisfied medicolegal requirements, health literacy considerations were reviewed regarding readability. This was assessed using McLaughlin’s Simple Measure of Gobbledygook (SMOG) formula, which identifies school stages that would have to be achieved to comprehend the PIL. The sensitivity of the results to alternative readability methods were assessed. Results: The PIL was not sufficient for modern consenting processes and reflected a suboptimal level of health literacy. Evaluation of the leaflet revealed key content was missing, including information pertaining to risks and benefits. Only five points out of the 20-point checklist were present. The readability score was 16, equivalent to a level 2 in National Adult Literacy Standards/Scottish Credit and Qualification Framework Level 5; 62% of Scottish adults are able to read to this standard. Discussion: Assessment of the leaflet showed it was no longer fit for purpose. Reasons include a lack of pertinent information, a text-heavy leaflet lacking flow, and content errors. The SMOG score indicates a high level of comprehension is required to understand this PIL, which many patients may not possess. A new PIL, compliant with medicolegal and health literacy guidance, was designed with patient-driven checklists, notes spaces for annotations/ questions and areas for clinicians to highlight important case-specific information. It has been tested using the SMOG formula. Conclusion: PILs can be extremely useful. Studies show that interactive use can enhance their effectiveness. PILs should reflect best practice guidance and be understood by patients. The 2020 leaflet designed and implemented aims to fulfill the needs of a modern healthcare system and its service users. It embraces and embeds Scotland’s Health Literacy Action Plan within the consenting process. A review of further leaflets using this model is ongoing.

Keywords: consent, health literacy, patient information leaflet, restorative dentistry

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Authors: Mahmoud Tarek Mohamed Hammad

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Despite the importance of the role and efforts made by the universities of the Kingdom of Saudi Arabia in reviving and preserving heritage architecture as an important cultural heritage in the Kingdom, The idea revolves around restoration and conservation processes and neglects the architectural heritage values, whose content can be used in sustainable contemporary architectural works. Educational values based on heritage architecture and how to integrate with the contemporary requirements were investigated in this research. For this purpose, by understanding the heritage architectural values as well as educational, academic process, the researcher presented an educational model of questionnaire forms for architecture students and the staff at the Architecture Department at Al-Baha University as a case study that serves the aims of the research. The results of the research show that heritage values especially those interview results are considered as a positive indicator of the importance of these values. The students and the staff need both to gain an understanding of heritage values as well as an understanding of theories of incorporating those values into the design process of contemporary local architecture. The research concludes that a correct understanding of the heritage values, its performance, and its reintegration with modern architecture technology should be focused on architectural education.

Keywords: heritage architecture, academic work, heritage values, sustainable contemporary local architectural

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Authors: Ivan Tolj

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Water produced during electrochemical reaction in Proton Exchange Membrane (PEM) fuel cell can be used for internal humidification of reactant gases; hydrogen and air. On such a way it is possible to eliminate expensive external humidifiers and simplify fuel cell balance-of-plant (BoP). When fuel cell operates at constant temperature (usually between 60 °C and 80 °C) relatively cold and dry ambient air heats up quickly upon entering channels which cause further drop in relative humidity (below 20%). Low relative humidity of reactant gases dries up polymer membrane and decrease its proton conductivity which results in fuel cell performance drop. It is possible to maintain such temperature profile throughout fuel cell cathode channel which will result in close to 100 % RH. In order to achieve this, passive heat exchanger was designed using commercial CFD software (ANSYS Fluent). Such passive heat exchanger (with variable surface area) is suitable for small scale PEM fuel cells. In this study, passive heat exchanger for single PEM fuel cell segment (with 20 x 1 cm active area) was developed. Results show close to 100 % RH of air throughout cathode channel with increased fuel cell performance (mainly improved polarization curve) and improved durability.

Keywords: PEM fuel cell, passive heat exchange, relative humidity, thermal management

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Authors: Karolina Ziembowicz, Andrzej Nowak

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In the current study, we examined the consequences of adding prosodic cues to text communication by allowing users to observe the process of message creation while engaged in dyadic conversations. In the first condition, users interacted through a traditional chat that requires pressing ‘enter’ to make a message visible to an interlocutor. In another, text appeared on the screen simultaneously as the sender was writing it, letter after letter (Synchat condition), so that users could observe the varying rhythm of message production, precise timing of message appearance, typos and their corrections. The results show that the ability to observe the dynamics of message production had a twofold effect on the social interaction process. First, it enhanced the relational aspect of communication – interlocutors synchronized their emotional states during the interaction, their communication included more statements on relationship building, and they evaluated the Synchat medium as more personal and emotionally engaging. Second, it increased the coherence of communication, reflected in greater continuity of the topics raised in Synchat conversations. The results are discussed from the interaction design (IxD) perspective.

Keywords: chat communication, online conversation, prosody, social synchronization, interaction incoherence, relationship building

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Authors: Geetanjali Singh, R. J. Choudhary, Anjana Dogra

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Here we report the effects of anti-site disorder, present in the sample, on the magnetic properties of Sm₂NiMnO₆ (SNMO) thin films. To our best knowledge, there are no studies available on the thin films of SNMO. Thin films were grown using pulsed laser deposition technique on SrTiO₃ (STO) substrate under oxygen pressure of 800 mTorr. X-ray diffraction (XRD) profiles show that the film grown is epitaxial. Field cooled (FC) and zero field cooled (ZFC) magnetization curve increase as we decrease the temperature till ~135K. A broad dip was observed in both the curves below this temperature which is more dominating in ZFC curve. An additional sharp cusplike shape was observed at low temperature (~20 K) which is due to the re-entrant spin-glass like properties present in the sample. Super-exchange interaction between Ni²⁺-O-Mn⁴⁺ is attributed to the FM ordering in these samples. The spin-glass feature is due to anti-site disorder within the homogeneous sample which was stated to be due to the mixed valence states Ni³⁺ and Mn³⁺ present in the sample. Anti-site disorder was found to play very crucial role in different magnetic phases of the sample.

Keywords: double perovskite, pulsed laser deposition, spin-glass, magnetization

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Authors: Sivia Amado Cordeiro, Bruna Rodrigues, Maria Do Ceu Taveira, Catia Marques, Iris Oliveira, Ana Daniela Silva, Cristina Costa-Lobo

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This work intends to analyse the teaching of Psychology in Portugal and, particularly, the teaching of Career Psychology, reflecting about the changes that have occurred to date. Were analysed the educational offerings of 31 Portuguese higher education institutions, 12 public and 19 private, who teach the course of Psychology. The three degrees of study were considered, namely, bachelors, masters and doctoral. The analysis of the data focused on the curricular plans of the different degrees of studies in Psychology made available online by higher education institutions. Through them, we identified the curricular units with themes related to the teaching of Career Psychology. The results show the existence of 89 higher psychology courses in Portugal, distributed throughout the three degrees of studies. Concerning to the teaching of Career Psychology there were registered 49 curricular units with themes dedicated to this area of knowledge. There were identified 16 curricular units in the bachelor’s degree, 31 in master’s degree, and two in doctoral degree. It was observed a reduction in the number of degrees in Psychology in the last nine years in Portugal. We discuss the current situation of Psychology teaching, particularly the teaching of Career Psychology. The aim is to stimulate reflection about future perspectives of Psychology teaching, and specifically, specialized training in Psychology of Career, in Portugal.

Keywords: career psychology, higher education, psychology, Portugal

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Authors: Robin Becker, Maike Eilers, Nane Roetmann, Manfred Helmus

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The shortage of junior staff in the construction industry is a problem that will be further exacerbated in the coming years by the retirement of the baby-boom generations (1955-1969) from employment. In addition, the current working conditions in the field of construction management are not attractive for young professionals. A survey of students revealed a desire for an increase in flexibility and an improved work-life balance in everyday working life. Students of civil engineering and architecture are basically interested in a career in construction management but have reservations due to the image of the profession and the current working conditions. A survey among experts from the construction industry shows that the profession can become more attractive. This report provides recommendations for action in the form of working modules to improve the working conditions of employees. If these are taken into account, graduates can be attracted to the profession of construction management, and existing staff can be retained more effectively. The aim of this report is to show incentives for employers to respond to the wishes and needs of their current and future employees to the extent that can be implemented.

Keywords: modern construction management, construction industry, work modules, shortage of junior staff, sustainable personnel management, making construction management more attractive, working time model

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Authors: Kalai Lamia, Jilani Faouzi

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Measuring and controlling risk is one of the most attractive issues in finance. With the persistence of uncontrolled and erratic stocks movements, volatility is perceived as a barometer of daily fluctuations. An objective measure of this variable seems then needed to control risks and cover those that are considered the most important. Non-linear autoregressive modeling is our first evaluation approach. In particular, we test the presence of “persistence” of conditional variance and the presence of a degree of a leverage effect. In order to resolve for the problem of “asymmetry” in volatility, the retained specifications point to the importance of stocks reactions in response to news. Effects of shocks on volatility highlight also the need to study the “long term” behaviour of conditional variance of stocks returns and articulate the presence of long memory and dependence of time series in the long run. We note that the integrated fractional autoregressive model allows for representing time series that show long-term conditional variance thanks to fractional integration parameters. In order to stop at the dynamics that manage time series, a comparative study of the results of the different models will allow for better understanding volatility structure over the Tunisia stock market, with the aim of accurately predicting fluctuation risks.

Keywords: asymmetry volatility, clustering, stylised facts, leverage effect

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Authors: Mohamed A. G. H. Abdalsadig, Amir Nourian, G. G. Nasr, M. Babaie

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Gas lift is one of the most common forms of artificial lift, particularly for offshore wells because of its relative down hole simplicity, flexibility, reliability, and ability to operate over a large range of rates and occupy very little space at the well head. Presently, petroleum industry is investing in exploration and development fields in offshore locations where oil and gas wells are being drilled thousands of feet below the ocean in high pressure and temperature conditions. Therefore, gas-lifted oil wells are capable of failure through gas lift valves which are considered as the heart of the gas lift system for controlling the amount of the gas inside the tubing string. The gas injection rate through gas lift valve must be controlled to be sufficient to obtain and maintain critical flow, also, gas lift valves must be designed not only to allow gas passage through it and prevent oil passage, but also for gas injection into wells to be started and stopped when needed. In this paper, smart gas lift valve has been used to investigate the effect of the valve port size, depth of injection and vertical lift performance on well productivity; all these aspects have been investigated using PROSPER simulator program coupled with experimental data. The results show that by using smart gas lift valve, the gas injection rate can be controlled which leads to improved flow performance.

Keywords: Effect of gas lift valve port size, effect water cut, vertical flow performance

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Authors: Artiya Sopharak, Tosaphol Ratniyomchai, Thanatchai Kulworawanichpong

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This paper presents an energy-saving study of Mass Rapid Transit (MRT) using an optimal train coasting operation. For the dynamic train movement with four modes of operation, including accelerating mode, constant speed or cruising mode, coasting mode, and braking mode are considered in this study. The acceleration rate, the deceleration rate, and the starting coasting point are taken into account the optimal train speed profile during coasting mode with considering the energy saving and acceptable travel time comparison to the based case with no coasting operation. In this study, the mathematical method as a Quadratic Search Method (QDS) is conducted to carry out the optimization problem. A single train of MRT services between two stations with a distance of 2 km and a maximum speed of 80 km/h is taken to be the case study. Regarding the coasting mode operation, the results show that the longer distance of costing mode, the less energy consumption in cruising mode and the less braking energy. On the other hand, the shorter distance of coasting mode, the more energy consumption in cruising mode and the more braking energy.

Keywords: energy saving, coasting mode, mass rapid transit, quadratic search method

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Authors: Ezekiel Ejiofor Nnadi

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Nigeria construction industry is known for its active construction activities. This has earmarked the industry to be the key to economic growth of the nation. It has largest employer of labour and gives sustenance to other industries like manufacturing industry. While this is a sign of growth and prosperity; the waste generated by the industry has always been a problem and a serious concern. It results in wastage of economic gain and has resultant health effect on the populace apart from injury being sustained on sites. This work provides a platform to learn more about construction waste, its management strategy and how to reduce waste production in Nigeria construction industry. Construction sites, waste management authority and public health institutions in Lagos as the centre of most construction activities in Nigeria were selected, and a set of questionnaire was administered to using the systematic sampling technique. Descriptive statistics and relative importance index (RII) technique were employed for the analysis of the data gathered. The findings of the analysis show that excessive wastes reduce contractors’ profit margin and also that some construction wastes contain hazardous and toxic elements such as lead, asbestos or radioactive materials which required proper handling and effective disposal. The conclusion was drawn that the check on waste on construction sites starts with the designers to the contractors who execute on site.

Keywords: construction cost, construction industry, economic growth, materials wastes

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Authors: Husain A. Murad, Ali A. Dashti, Ali Al-Kandari

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The outbreak of Coronavirus during the Spring semester of 2020 brought new challenges for the teaching of vocational mass communication courses at universities in Kuwait. Using the Media Richness Theory (MRT), this study examines the response of 252 university students on mass communication programs. A questionnaire regarding their perceptions and preferences concerning modes of instruction on vocational courses online, focusing on the four factors of MRT: immediacy of feedback, capacity to include personal focus, conveyance of multiple cues, and variety of language. The outcomes show that immediacy of feedback predicted all criterion variables: suitability of distance learning (DL) for teaching vocational courses, sentiments of students toward DL, perceptions of easiness of evaluation of DL coursework, and the possibility of retaking DL courses. Capacity to include personal focus was another positive predictor of the criterion variables. It predicted students’ sentiments toward DL and the possibility of retaking DL courses. The outcomes are discussed in relation to implications for using DL, as well as constructing an agenda for DL research.

Keywords: distance learning, media richness theory, traditional learning, vocational media courses

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Authors: Amar Boukerrou, Ouerdia Belhadj, Dalila Hammiche, Jean Francois Gerard, Jannick Rumeau

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The main goal of this study is the investigation of alfa fiber content, treated with alkali treatment, on the thermal and mechanical properties of epoxy-amine matrix-based composites. The fibers were treated with 5% of sodium hydroxide solution and varied between 10% to 30% weight fractions. The tensile, flexural, and hardness tests are carried out to investigate the mechanical properties of composites. The results show those composites’ mechanical properties are higher than the neat epoxy-amine. It was noticed that the alkali treatment is more effective in the case of the tensile and flexural modulus than the tensile and flexural strength. The decline of both the tensile and flexural behavior of all composites with the increasing of the filler content was due probably to the random dispersion of the fibers in the epoxy resin The Fourier transform infrared (FTIR) was employed to analyze the chemical structure of epoxy resin before and after curing with amine hardener. FTIR and DSC analysis confirmed that epoxy resin was completely cured with amine hardener at room temperature. SEM analysis has highlighted the microstructure of epoxy matrix and its composites.

Keywords: alfa fiber, epoxy resin, alkali treatment, mechanical properties

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Authors: Mohammad Qasim Mohammadi, Mohammad Arif Rohman

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Although socially sustainable building is becoming increasingly popular worldwide, past studies indicate that when policymakers support sustainable building development, the social dimension is often given insufficient attention or entirely disregarded. There are not many studies that focus on the problems of socially sustainable buildings in Afghanistan. This research investigates the factors that may hinder social sustainability implementation in residential building construction. The study will gather data from construction professionals by purposive sampling and employ Exploratory Factor Analysis (EFA) and Varimax for analysis. The results will undergo rigorous examination and thorough discussion. The expected results in this research will analyze the underlying barrier structure (factors) that hinder social sustainability, and each of these factors will represent a set of observed variables. In addition, the factor loadings show which barriers pose the greatest challenges. The primary goal of this study is to provide valuable insights into the impediment factors of social sustainability within the residential building environment, aiming to inform decision-making in the industry and encourage the adoption of more socially sustainable construction practices.

Keywords: social sustainability, residential building, barriers, drivers, afghanistan, factor analysis

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Authors: Arnab Mondal, Sanjeev Kumar Sharma, Ranjit Kumar Upadhyay

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We study the spatiotemporal dynamics of a neuronal cable. The processes of one- dimensional (1D) and 2D diffusion are considered for a single variable, which is the membrane voltage, i.e., membrane voltage diffusively interacts for spatiotemporal pattern formalism. The recovery and other variables interact through the membrane voltage. A 3D Leech-Heart (LH) model is introduced to investigate the nonlinear responses of an excitable neuronal cable. The deterministic LH model shows different types of firing properties. We explore the parameter space of the uncoupled LH model and based on the bifurcation diagram, considering v_k2_ashift as a bifurcation parameter, we analyze the 1D diffusion dynamics in three regimes: bursting, regular spiking, and a quiescent state. Depending on parameters, it is shown that the diffusive system may generate regular and irregular bursting or spiking behavior. Further, it is explored a 2D diffusion acting on the membrane voltage, where different types of patterns can be observed. The results show that the LH neurons with different firing characteristics depending on the control parameters participate in a collective behavior of an information processing system that depends on the overall network.

Keywords: bifurcation, pattern formation, spatio-temporal dynamics, stability analysis

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Authors: Poh Im. Lim, Hillary Yee Qin. Tan

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Nowadays, going green has become a trend, and being emphasized in the construction industry. In Malaysia, there are several green rating tools available in the industry and among these, GBI and GreenRE are considered as the most common tools adopted for residential buildings. However, being green is not equal to or making something sustainable. Being sustainable is to take economic, environmental and social aspects into consideration. This is particularly essential in the affordable housing sector as the end-users belong to lower-income and places importance on many socio-economic needs beyond the environmental criteria. This paper discusses the arguments in proposing a sustainability framework that is tailor-made for high-rise affordable housing. In-depth interviews and observation mapping methods were used in gathering inputs from the end-users, non-governmental organisations (NGOs) as well as the professionals. ‘Bottom-up’ approach was applied in this research to show the significance of participation from the local community in the decision-making process. The proposed sustainability framework illustrates the discrepancies between user priorities and what the industry is providing. The outcome of this research suggests that integrating sustainability into high-rise affordable housing is achievable and beneficial to the industry, society, and the environment.

Keywords: green building rating tools, high-rise affordable housing, sustainability framework, sustainable development

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Authors: Sayed Hessam Bahmani, Rolsndo P. Orense

Abstract:

From an engineering point of view, pumice particles are problematic because of their crushability and compressibility due to their vesicular nature. Currently, information on the geotechnical characteristics of pumice sands is limited. While extensive empirical and laboratory tests can be implemented to characterize their behavior, these are generally time-consuming and expensive. These drawbacks have motivated attempts to study the effects of particle breakage of pumice sand through the Discrete Element Method (DEM). This method provides insights into the behavior of crushable granular material at both the micro and macro-level. In this paper, the results of single-particle crushing tests conducted in the laboratory are simulated using DEM through the open-source code YADE. This is done to better understand the parameters necessary to represent the pumice microstructure that governs its crushing features, and to examine how the resulting microstructure evolution affects a particle’s properties. The DEM particle model is then used to simulate the behavior of pumice sand during consolidated drained triaxial tests. The results indicate the importance of incorporating particle porosity and unique surface textures in the material characterization and show that interlocking between the crushed particles significantly influences the drained behavior of the pumice specimen.

Keywords: pumice sand, triaxial compression, simulation, particle breakage

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Authors: A. A. Ahmadi, A. R. Pishevar, M. Nili

Abstract:

As the test gas in a gun tunnel is non-isentropically compressed and heated by a light weight piston. Here, first consideration is the optimum piston weight. Although various aspects of the influence of piston weight on gun tunnel performance have been studied, it is not possible to decide from the existing literature what piston weight is required for optimum performance in various conditions. The technique whereby the piston is rapidly brought to rest at the end of the gun tunnel barrel, and the resulted peak pressure is equal in magnitude to the final equilibrium pressure, is called the equilibrium piston technique. The equilibrium piston technique was developed to estimate the equilibrium piston mass; but this technique cannot give an appropriate estimate for the optimum piston weight. In the present work, a gun tunnel with diameter of 3 in. is described and its performance is investigated numerically to obtain the effect of piston and its weight. Numerical results in the present work are in very good agreement with experimental results. Significant influence of the existence of a piston is shown by comparing the gun tunnel results with results of a conventional shock tunnel in the same dimension and same initial condition. In gun tunnel, an increase of around 250% in running time is gained relative to shock tunnel. Also, Numerical results show that equilibrium piston technique is not a good way to estimate suitable piston weight and there will be a lighter piston which can increase running time of the gun tunnel around 60%.

Keywords: gun tunnel, hypersonic flow, piston, shock tunnel

Procedia PDF Downloads 373

Authors: Rajiv Kumar, Amit Sachan, Arindam Mukherjee

Abstract:

Despite the transparency and benefits of e-government, and its potential to serve citizens better, there is low diffusion and adoption of e-government services in India. Limited access to computer and internet, lack of computer and internet skills, low trust in technology, and risk associated in using e-government services are major hindrances in e-government adoption in India. Despite a large number of citizens belonging to the non-adopter category, the government has made some services mandatory to be accessed online where citizens have no other choice. Also despite the digital divide, a large number of citizens prefer online access to government services. In such cases intermediaries like common service centers, internet café and services agents’ roles are significant for accessing e-government services. Hence research is needed to explore this. The study aims to investigate the role of intermediaries in online access to public services by citizens. Qualitative research methodology using semi-structured interview was used. The results show that intermediaries play an important role in bridging the digital divide. The study also highlights on what circumstances citizens are taking help of these intermediaries. The study then highlights its limitations and discusses scope for future study.

Keywords: adoption, digital divide, e-government, India, intermediaries

Procedia PDF Downloads 294

Authors: S. A. Naeini, H. R. Rahmani, M. Hossein Zade

Abstract:

Many classical bearing capacity theories assume that the natural soil's layers are homogenous for determining the bearing capacity of the soil. But, in many practical projects, we encounter multi-layer soils. Geosynthetic as reinforcement materials have been extensively used in the construction of various structures. In this paper, numerical analysis of the Plate Load Test (PLT) using of ABAQUS software in double-layered soils with different thicknesses of sandy and gravelly layers reinforced with geogrid was considered. The PLT is one of the common filed methods to calculate parameters such as soil bearing capacity, the evaluation of the compressibility and the determination of the Subgrade Reaction module. In fact, the influence of the geogrid layers on the bearing capacity of the layered soils is investigated. Finally, the most appropriate mode for the distance and number of reinforcement layers is determined. Results show that using three layers of geogrid with a distance of 0.3 times the width of the loading plate has the highest efficiency in bearing capacity of double-layer (sand and gravel) soils. Also, the significant increase in bearing capacity between unreinforced and reinforced soil with three layers of geogrid is caused by the condition that the upper layer (gravel) thickness is equal to the loading plate width.

Keywords: bearing capacity, reinforcement, geogrid, plate load test, layered soils

Procedia PDF Downloads 174