Search results for: case report

Authors: F. A. Rodríguez-Prada, W Gutierrez, I. D. Mikhailov

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We study the spectral properties of one-electron non-uniform crater-shaped quantum dot whose thickness is increased linearly with different slopes in different radial directions between the central hole and the outer border and which is deposited over thin wetting layer in the presence of the external vertically directed magnetic field. We show that in the adiabatic limit, when the crater thickness is much smaller than its lateral dimension, the one-particle wave functions of the electron confined in such structure in the zero magnetic field case can be found exactly in an analytical form and they can be used subsequently as the base functions in framework of the exact diagonalization method to study the effect of the wetting layer and an external magnetic field applied along of the grown axis on energy levels of one-electron non-uniform quantum dot. It is shown that both the structural non-uniformity and the increase of the thickness of the wetting layer provide a quenching of the Aharonov-Bohm oscillations of the lower energy levels.

Keywords: electronic properties, quantum rings, volcano shaped, wetting layer

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Authors: H. Alheeh, M. Alameri, A. Al Tarabsheh

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There has been a growing interest in CMOS-based sensors technology in cameras as they afford low-power, small-size, and cost-effective imaging systems. This article describes the CMOS image sensor pixel categories and presents the design and the simulation of the 3-Transistor (3T) Active Pixel Sensor (APS) in MATLAB/Simulink tool. The analysis investigates the conversion of the light into an electrical signal for a single pixel sensing circuit, which consists of a photodiode and three NMOS transistors. The paper also proposes three modes for the pixel operation; reset, integration, and readout modes. The simulations of the electrical signals for each of the studied modes of operation show how the output electrical signals are correlated to the input light intensities. The charging/discharging speed for the photodiodes is also investigated. The output voltage for different light intensities, including in dark case, is calculated and showed its inverse proportionality with the light intensity.

Keywords: APS, CMOS image sensor, light intensities photodiode, simulation

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Authors: Ankita Jadon, Sidi Souvi, Nathalie Girault, Denis Petitprez

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Safety requirements for Generation IV nuclear reactor designs, especially the new generation sodium-cooled fast reactors (SFR) require a risk-informed approach to model severe accidents (SA) and their consequences in case of outside release. In SFRs, aerosols are produced during a core disruptive accident when primary system sodium is ejected into the containment and burn in contact with the air; producing sodium aerosols. One of the key aspects of safety evaluation is the in-containment sodium aerosol behavior and their interaction with fission products. The study of the effects of sodium fires is essential for safety evaluation as the fire can both thermally damage the containment vessel and cause an overpressurization risk. Besides, during the fire, airborne fission product first dissolved in the primary sodium can be aerosolized or, as it can be the case for fission products, released under the gaseous form. The objective of this work is to study the interactions between sodium aerosols and fission products (Iodine, toxic and volatile, being the primary concern). Sodium fires resulting from an SA would produce aerosols consisting of sodium peroxides, hydroxides, carbonates, and bicarbonates. In addition to being toxic (in oxide form), this aerosol will then become radioactive. If such aerosols are leaked into the environment, they can pose a danger to the ecosystem. Depending on the chemical affinity of these chemical forms with fission products, the radiological consequences of an SA leading to containment leak tightness loss will also be affected. This work is split into two phases. Firstly, a method to theoretically understand the kinetics and thermodynamics of the heterogeneous reaction between sodium aerosols and fission products: I2 and HI are proposed. Ab-initio, density functional theory (DFT) calculations using Vienna ab-initio simulation package are carried out to develop an understanding of the surfaces of sodium carbonate (Na2CO3) aerosols and hence provide insight on its affinity towards iodine species. A comprehensive study of I2 and HI adsorption, as well as bicarbonate formation on the calculated lowest energy surface of Na2CO3, was performed which provided adsorption energies and description of the optimized configuration of adsorbate on the stable surface. Secondly, the heterogeneous reaction between (I2)g and Na2CO3 aerosols were investigated experimentally. To study this, (I2)g was generated by heating a permeation tube containing solid I2, and, passing it through a reaction chamber containing Na2CO3 aerosol deposit. The concentration of iodine was then measured at the exit of the reaction chamber. Preliminary observations indicate that there is an effective uptake of (I2)g on Na2CO3 surface, as suggested by our theoretical chemistry calculations. This work is the first step in addressing the gaps in knowledge of in-containment and atmospheric source term which are essential aspects of safety evaluation of SFR SA. In particular, this study is aimed to determine and characterize the radiological and chemical source term. These results will then provide useful insights for the developments of new models to be implemented in integrated computer simulation tool to analyze and evaluate SFR safety designs.

Keywords: iodine adsorption, sodium aerosols, sodium cooled reactor, DFT calculations, sodium carbonate

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Authors: Lusungu Ndovi

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Radio propagation from point-to-point is affected by the physical channel in many ways. A signal arriving at a destination travels through a number of different paths which are referred to as multi-paths. Research in this area of wireless communications has progressed well over the years with the research taking different angles of focus. By this is meant that some researchers focus on ways of reducing or eluding Multipath effects whilst others focus on ways of mitigating the effects of Multipath through compensation schemes. Baseband processing is seen as one field of signal processing that is cardinal to the advancement of software-defined radio technology. This has led to wide research into the carrying out certain algorithms at baseband. This paper considers compensating for Multipath for Frequency Modulated signals. The compensation process is carried out at Radio frequency (RF) and at Quadrature baseband (QBB) and the results are compared. Simulations are carried out using MatLab so as to show the benefits of working at lower QBB frequencies than at RF.

Keywords: quadrature baseband, qadio frequency, qultipath compensation, frequency qodulation, signal processing

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Authors: ShiQing Gao, XingYi Zhang, YouHe Zhou

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When a floating tilted cylinder pierces a fluid interface, the fulfilment of constant-contact-angle condition along the cylinder results in shift, stretch and distortion of the contact line, thus leading to a capillary interaction. We perform an investigation of the scaling dependence of tilt angle, contact angle, and cylinder radius on the contact line profile and the corresponding capillary interaction by numerical simulation and experiment. Characterized by three characteristic parameters respectively, the dependences for each deformation mode are systematically analyzed. Both the experiment and simulation reveals an invariant structure that is independent of contact angle and radius to characterize the stretch of the contact line for every tilted case. Based on this observation, we then propose a general capillary force scaling law to incredibly grasp all the simulated results, by simply approximating the contact line profile as tilted ellipse.

Keywords: gas-liquid/liquid-fluid interface, colloidal particle, contact line shape, capillary interaction, surface evolver (SE)

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Authors: Amir E. Amirzadeh, Richard K. Strand

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Moisture-induced problems are a significant concern for building owners, architects, construction managers, and building engineers, as they can have substantial impacts on building enclosures' durability and performance. Computational analyses, such as hygrothermal and thermal analysis, can provide valuable information and demonstrate the expected relative performance of building enclosure systems but are not grounded in absolute certainty. This paper evaluates the hygrothermal performance of common enclosure systems in hospitals in cold climates. The study aims to investigate the impact of exterior wall systems on hospitals, focusing on factors such as durability, construction deficiencies, and energy performance. The study primarily examines the impact of air leakage and vapor retarding layers relative to energy consumption. While these factors have been studied in residential and commercial buildings, there is a lack of information on their impact on hospitals in a holistic context. The study integrates various research studies and professional experience in hospital building design to achieve its objective. The methodology involves surveying and observing exterior wall assemblies, reviewing common exterior wall assemblies and details used in hospital construction, performing simulations and numerical analyses of various variables, validating the model and mechanism using available data from industry and academia, visualizing the outcomes of the analysis, and developing a mechanism to demonstrate the relative performance of exterior wall systems for hospitals under specific conditions. The data sources include case studies from real-world projects and peer-reviewed articles, industry standards, and practices. This research intends to integrate and analyze the in-situ and as-designed performance and durability of building enclosure assemblies with numerical analysis. The study's primary objective is to provide a clear and precise roadmap to better visualize and comprehend the correlation between the durability and performance of common exterior wall systems used in the construction of hospitals and the energy consumption of these buildings under certain static and dynamic conditions. As the construction of new hospitals and renovation of existing ones have grown over the last few years, it is crucial to understand the effect of poor detailing or construction deficiencies on building enclosure systems' performance and durability in healthcare buildings. This study aims to assist stakeholders involved in hospital design, construction, and maintenance in selecting durable and high-performing wall systems. It highlights the importance of early design evaluation, regular quality control during the construction of hospitals, and understanding the potential impacts of improper and inconsistent maintenance and operation practices on occupants, owner, building enclosure systems, and Heating, Ventilation, and Air Conditioning (HVAC) systems, even if they are designed to meet the project requirements.

Keywords: hygrothermal analysis, building enclosure, hospitals, energy efficiency, optimization and visualization, uncertainty and decision making

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Authors: M. A. T. AlSudairi, T. G. K. Vasista

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The concept of social media is becoming the top of the agenda for many business executives and public sector executives today. Decision makers as well as consultants, try to identify ways in which firms and enterprises can make profitable use of social media and network related applications such as Wikipedia, Face book, YouTube, Google+, Twitter. While it is fun and useful to participating in this media and network for achieving the communication effectively and efficiently, semantic and sentiment analysis and interpretation becomes a crucial issue. So, the objective of this paper is to provide literature review on social media, network and related technology related to semantics and sentiment or opinion analysis covering business and governance perspectives. In this regard, a case study on the use and adoption of Social media in Saudi Arabia has been discussed. It is concluded that semantic web technology play a significant role in analyzing the social networks and social media content for extracting the interpretational knowledge towards strategic decision support.

Keywords: CRASP methodology, formative assessment, literature review, semantic web services, social media, social networks

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Authors: Elisa Orofino

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Islamism is a very debated topic in the West but almost exclusively explored in its violent forms. Nevertheless, a number of “vocal radical Islamist” groups exist in the West and legally operate because of their non-violent nature. Vocal radicals continually inspire individuals and lead them towards specific goals and priorities, sometimes even towards violence. This paper uses the long-living group Hizb ut-Tahrir (HT) to explore the elements that make the organization appealing to segments of Muslim community in the West. This paper uses three agency variables - reflexive monitoring, the rationalization of action and the motivations for actions – to analyze HT’s appeal vis-à-vis two other Islamist groups, Ikhwan al-Muslimun and Jamaat-e-Islami (JeI), having similar goals and the same high international profile. This paper concludes that HT’s uniqueness is given by its method, detailed vision of the caliphate, consistency over time and the emphasis placed on the caliphate as the leading force of HT’s unchanged motivation for action.

Keywords: agency, caliphate, Islamist groups, radicalization, vocal radicals

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Authors: Camille Paldi

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As the Islamic finance industry is growing annually at a rate of 10% to 15% per year, it is imperative that a unique, independent legal framework is established in order to effectively adjudicate Islamic finance disputes. Currently, Islamic finance disputes are being adjudicated in inadequate civil and common law courts and arbitration centers where the contracts in dispute are being transformed from Islamic to conventional transactions. Through case analysis combined with an exploration of the efficacy of existing arbitration centers and dispute resolution methods available to Islamic finance, this paper will seek to reveal that the Islamic finance industry currently lacks an adequate dispute resolution mechanism and facility to adjudicate disputes arising from Islamic finance contracts. Hence, now is the time for the Dubai World Islamic Finance Arbitration Center (DWIFAC) and Jurisprudence Office (DWIFACJO) as the Dispute Resolution Center and Mechanism for the Islamic Finance Industry.

Keywords: Islamic finance, dispute resolution, Dubai world Islamic finance arbitration center, jurisprudence office

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Authors: Ashok Kumar, Shiv Brat Singh, Kalyan Kumar Ray

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There is growing awareness to design steels against fatigue damage Ferrite martensite dual-phase steels are known to exhibit favourable mechanical properties like good strength, ductility, toughness, continuous yielding, and high work hardening rate. However, dual-phase steels containing bainite as second phase are potential alternatives for ferrite martensite steels for certain applications where good fatigue property is required. Fatigue properties of dual phase steels are popularly assessed by the nature of variation of crack growth rate (da/dN) with stress intensity factor range (∆K), and the magnitude of fatigue threshold (∆Kth) for long cracks. There exists an increased emphasis to understand not only the long crack fatigue behavior but also short crack growth behavior of ferrite bainite dual phase steels. The major objective of this report is to examine the influence of microstructures on the short and long crack growth behavior of a series of developed dual-phase steels with varying amounts of bainite and. Three low carbon steels containing Nb, Cr and Mo as microalloying elements steels were selected for making ferrite-bainite dual-phase microstructures by suitable heat treatments. The heat treatment consisted of austenitizing the steel at 1100°C for 20 min, cooling at different rates in air prior to soaking these in a salt bath at 500°C for one hour, and finally quenching in water. Tensile tests were carried out on 25 mm gauge length specimens with 5 mm diameter using nominal strain rate 0.6x10⁻³ s⁻¹ at room temperature. Fatigue crack growth studies were made on a recently developed specimen configuration using a rotating bending machine. The crack growth was monitored by interrupting the test and observing the specimens under an optical microscope connected to an Image analyzer. The estimated crack lengths (a) at varying number of cycles (N) in different fatigue experiments were analyzed to obtain log da/dN vs. log °∆K curves for determining ∆Kthsc. The microstructural features of these steels have been characterized and their influence on the near threshold crack growth has been examined. This investigation, in brief, involves (i) the estimation of ∆Kthsc and (ii) the examination of the influence of microstructure on short and long crack fatigue threshold. The maximum fatigue threshold values obtained from short crack growth experiments on various specimens of dual-phase steels containing different amounts of bainite are found to increase with increasing bainite content in all the investigated steels. The variations of fatigue behavior of the selected steel samples have been explained with the consideration of varying amounts of the constituent phases and their interactions with the generated microstructures during cyclic loading. Quantitative estimation of the different types of fatigue crack paths indicates that the propensity of a crack to pass through the interfaces depends on the relative amount of the microstructural constituents. The fatigue crack path is found to be predominantly intra-granular except for the ones containing > 70% bainite in which it is predominantly inter-granular.

Keywords: bainite, dual phase steel, fatigue crack growth rate, long crack fatigue threshold, short crack fatigue threshold

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Authors: Sara Blanc, José V. Benlloch-Dualde, Laura Grindei, Ana C. Torres, Angélica Monteiro

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This paper presents a study that leads a new experience by introducing digital learning applied to a case study focused on primary and secondary school garden-based education. The approach represents an example of interaction among different education and research agents at different countries and levels, such as universities, public and private research, and schools, to get involved in the implementation of education for sustainable development that will make students become more sensible to natural environment, more responsible for their consumption, more aware about waste reduction and recycling, more conscious of the sustainable use of natural resources and, at the same time, more ‘digitally competent’. The experience was designed attending to the European digital education context and OECD directives in transversal skills education. The paper presents the methodology carried out in the study as well as outcomes obtained from experience.

Keywords: school gardens, primary education, secondary education, science technology and innovation in education, digital learning, sustainable development goals, university, knowledge transference

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Authors: Azar Khodabakhshi, Elham Bolandnazar

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Agriculture as the most important food manufacturing sector is not only the energy consumer, but also is known as energy supplier. Using energy is considered as a helpful parameter for analyzing and evaluating the agricultural sustainability. In this study, the pattern of energy consumption of strawberry greenhouses of Jiroft in Kerman province of Iran was surveyed. The total input energy required in the strawberries production was calculated as 113314.71 MJ /ha. Electricity with 38.34% contribution of the total energy was considered as the most energy consumer in strawberry production. In this study, Neuro Fuzzy networks was used for function modeling in the production of strawberries. Results showed that the best model for predicting the strawberries function had a correlation coefficient, root mean square error (RMSE) and mean absolute percentage error (MAPE) equal to 0.9849, 0.0154 kg/ha and 0.11% respectively. Regards to these results, it can be said that Neuro Fuzzy method can be well predicted and modeled the strawberry crop function.

Keywords: crop yield, energy, neuro-fuzzy method, strawberry

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Authors: Avi Shrivastava

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Our world continues to grapple with a lot of social issues. Economic growth and scientific advancements have not completely eradicated poverty, homelessness, discrimination and bias, gender inequality, health issues, mental illness, addiction, and other social issues. So, how do we improve the human condition in a world driven by advanced technology? The answer is simple: we will have to leverage technology to address some of the most important social challenges of the day. AI, or artificial intelligence, has emerged as a critical tool in the battle against issues that deprive marginalized and disadvantaged groups of the right to enjoy benefits that a society offers. Social work professionals can transform their lives by harnessing it. The lack of reliable data is one of the reasons why a lot of social work projects fail. Social work professionals continue to rely on expensive and time-consuming primary data collection methods, such as observation, surveys, questionnaires, and interviews, instead of tapping into AI-based technology to generate useful, real-time data and necessary insights. By leveraging AI’s data-mining ability, we can gain a deeper understanding of how to solve complex social problems and change lives of people. We can do the right work for the right people and at the right time. For example, AI can enable social work professionals to focus their humanitarian efforts on some of the world’s poorest regions, where there is extreme poverty. An interdisciplinary team of Stanford scientists, Marshall Burke, Stefano Ermon, David Lobell, Michael Xie, and Neal Jean, used AI to spot global poverty zones – identifying such zones is a key step in the fight against poverty. The scientists combined daytime and nighttime satellite imagery with machine learning algorithms to predict poverty in Nigeria, Uganda, Tanzania, Rwanda, and Malawi. In an article published by Stanford News, Stanford researchers use dark of night and machine learning, Ermon explained that they provided the machine-learning system, an application of AI, with the high-resolution satellite images and asked it to predict poverty in the African region. “The system essentially learned how to solve the problem by comparing those two sets of images [daytime and nighttime].” This is one example of how AI can be used by social work professionals to reach regions that need their aid the most. It can also help identify sources of inequality and conflict, which could reduce inequalities, according to Nature’s study, titled The role of artificial intelligence in achieving the Sustainable Development Goals, published in 2020. The report also notes that AI can help achieve 79 percent of the United Nation’s (UN) Sustainable Development Goals (SDG). AI is impacting our everyday lives in multiple amazing ways, yet some people do not know much about it. If someone is not familiar with this technology, they may be reluctant to use it to solve social issues. So, before we talk more about the use of AI to accomplish social work objectives, let’s put the spotlight on how AI and social work can complement each other.

Keywords: social work, artificial intelligence, AI based social work, machine learning, technology

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Authors: Joshua Teo, Leo Phan

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Signet cell carcinoma of the appendix is the rarest and the most aggressive subtype of appendiceal malignancy, typically with non-specific presentations. We describe a case of a 62-year-old male with large bowel obstruction and CT demonstrating dilated large bowels from caecum to proximal sigmoid colon with pneumoperitoneum. Intra-operatively, closed-loop obstruction caused by dense adherence of sigmoid colon to caecum was noted, which had resulted in caecal perforation. Histopathology study indicated primary appendiceal malignancy of signet cell morphology with intra-peritoneal spread to the sigmoid colon. Large bowel obstruction from appendiceal malignancy has rarely been reported, and a similar presentation has not been described in the existing literature. When left-sided large bowel obstruction is suspected to be caused by a malignant stricture, it is essential to consider transperitoneal spread of appendiceal malignancy as potential aetiology, particularly in the elderly.

Keywords: appendiceal carcinoma, large bowel obstruction, signet ring cell cancer, caecal perforation

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Authors: Md. Musfiqur Rahman Bhuiya Nidalia Islam, Hossain Mohiuddin, Md. Kawser Bin Zaman

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Dhaka North City Corporation introduced first area-based bus service on 10 August 2016 to run through Gulshan and Banani area to dilute sufferings of the people which started with the ban on movement of the bus in these areas after Holy Artisan terrorist attack. This study explores service quality performance of Dhaka Chaka on the basis of information provided by its riders on a questionnaire survey. Total thirteen service quality indicators have been ranked on a scale of 1-5, and they have been classified under three latent variables based on their correlation using eigenvalue and rotated factor matrix derived through factor analysis process. Mean, and skewness has been calculated for each indicator. It has been found that ticket price and ticketing system have relatively poor average service quality rank than other factors. All other factors have moderately good performance. The study also suggests some recommendation to improve service quality of Dhaka Chaka based on the interrelation between considered parameters.

Keywords: area based bus service, eigen value, factor analysis, correlation

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Authors: Min Zhou, Kaixuan Lin, Yaping Huang

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In this paper, the industrial space of metropolitan area in Wuhan is taken as a sample. First of all, it puts forward that the structure of service economy, circle gradient relocation and high degree of regional collaboration are the rules of industrial spatial development in the modern world cities. Secondly, using the economic statistics and land use vector data (1993, 2004, 2010, and 2013) of Wuhan, it analyzes the present situation of industry development and the characteristics of industrial space layout from three aspects of the industrial economic structure, industrial layout, and industrial regional synergy. Then, based on the industrial development regularity of world cities, it puts forward to construct the industrial spatial level of ‘complex industrial concentration area + modular industry unit’ and the industrial spatial structure of ‘13525’. Finally, it comes up with the optimization tactics of the industrial space’s transformation in the future under the background of new economic era.

Keywords: big city of metropolitan area, industrial space, characteristics, layout, strategy

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Authors: Neda Torabi Farsani, Mohammad Mortazavi, Maryam Masaeli

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Nowadays intangible heritage as a creative product plays an important role in promoting tourism. The intangible heritage is transmitted from past generation to the present and future generation and constantly recreated by communities and groups in response to their environment, nature and history. In recent decade, intangible heritage especially Pahlevāni and Zoorkhāneh rituals as creative cultural product attract many tourists to a destination and they well-known as tourist attractions in Iran. The study was conducted in Isfahan city. This research has two major purposes: 1) to introduce Pahlevāni and Zoorkhāneh ritual as tourist attraction and, 2) to investigate the attitude of domestic tourists towards Pahlevāni and Zoorkhāneh ritual in Isfahan city. On the basis of the results of this study, it can be concluded that the domestic tourists are interested in gaining experience and increasing their knowledge in Pahlevāni and Zoorkhāneh ritual.

Keywords: Isfahan, Pahlevāni and Zoorkhāneh ritual, tourist attitude, Iran

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Authors: Tu Shuyang, Zhang Xu, Zhou Xiang

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The objective of this paper is to investigate the effect of short-term heat exchange decay of ground heat exchanger (GHE) on the ground source heat pump (GSHP) energy efficiency and capacity. A resistance-capacitance (RC) model was developed and adopted to simulate the transient characteristics of the ground thermal condition and heat exchange. The capacity change of the GSHP was linked to the inlet and outlet water temperature by polynomial fitting according to measured parameters given by heat pump manufacturers. Thus, the model, which combined the heat exchange decay with the capacity change, reflected the energy efficiency decay of the whole system. A case of GSHP system was analyzed by the model, and the result showed that there was risk that the GSHP might not meet the load demand because of the efficiency decay in a short-term operation. The conclusion would provide some guidances for GSHP system design to overcome the risk.

Keywords: capacity, energy efficiency, GSHP, heat exchange

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Authors: Ahmadali Shirazytabar, Hamidreza Namazi

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As water resources are rapidly getting diminished, more and more interest is paid to the desalination of saline waters. Desalination has become a reliable and cost effective solution in provision of fresh water particularly in the arid areas of the world such as Middle East countries. However, the dramatic increase of utilizing desalination will cause a series of problems which are significantly related to energy consumption and environment impacts. The use of renewable energy sources to provide energy required by desalination processes is a feasible and simultaneously environmental friendly solution. In this study an attempt has been made to present a review on desalination technologies, desalination integrated with renewable energies, in brief, and practical progresses made during recent years particularly in the field of desalination by wind energy which is the most common form of renewable energies. Moreover, an economic analysis of a wind powered RO desalination system comprising of 10×2.5 MW wind turbines is done, and the results will be compared to those of a cogeneration system comprising of one 25 MW gas turbines, heat recovery steam generators (HRSG) and MED-TVC desalination.

Keywords: wind turbine, desalination, RO, MED, cogeneration, gas turbine, HRSG

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Authors: Gauravi Agarkar, Mahendra Rai

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Endophytic fungi from medicinal plants are important source of numerous pharmacologically important compounds. In the present investigation, the endophytic fungi were isolated from three medicinal plants; Andrographis paniculata, Rauwolfia serpentina and Tridax procumbens. Endophytic Colletotrichum sp. were identified on the basis of cultural and morphological characteristics as well as internal transcribed spacer (ITS) sequence analysis. Antibacterial and antifungal activity of the ethyl acetate and methanol extract of endophytic Colletotrichum sp. was evaluated against seven different human pathogenic bacteria and six Candida sp. The extracts were effective and showed significant activity against all the test pathogens. In case of yeast Candida, the combined effect of extracts and standard antibiotic was enhanced greatly showing synergistic activity. Further, the extracts were assayed for Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal/Fungicidal Concentration (MBC/MFC) where, MIC values were in the range of 100-250 μg/ml. These results suggest that the endophytic Colletotrichum sp. isolated from the medicinal plants are capable of producing promising antimicrobial metabolites.

Keywords: antimicrobial, colletotrichum, endophytic fungi, medicinal plants

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Authors: Washima Tuleun

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Cybercrime is a global concern, and Nigeria is not immune to its effects. This paper investigates the cybercrimes and significant cyber-attacks that have targeted businesses and institutions in Nigeria, examining their various forms and the financial and economic impacts they have on individuals, businesses, and the nation as a whole. As technological advancements rapidly evolve and online services gain widespread adoption, there has been a corresponding rise in cyber-related attacks. These attacks often target personal data, exploit system vulnerabilities, and result in the theft of sensitive information, leading to financial losses, reputational damage, and broader impacts on organizations. The study conducts a thorough review of existing literature, case studies, and statistical data to provide a comprehensive understanding of Nigeria’s cybercrime landscape. Additionally, it assesses the efforts by both the government and the private sector to address these challenges and offers recommendations for more effective strategies to mitigate and reduce their impact.

Keywords: cybersecurity, telecommunications engineering, information technology, threat intelligence, vulnerability management, computing

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Authors: Ashleigh Dawn Moeller

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This is a comparative case study which examines the language attitudes and behaviors of descendants of Volga German immigrants in North America and how these attitudes combined with surrounding social conditions have caused their heritage language to develop differently within each community. Of particular interest for this study are the accounts of second- and third-generation descendants in Oregon, Kansas, and North Dakota regarding their parents’ and grandparents’ attitudes toward their language and how this correlates with the current sentiment as well as visibility of their heritage language and culture. This study discusses the point at which cultural identity could diverge from language identity and what elements play a role in this development, establishing the potential for environments (linguistic landscapes) which uphold their heritage yet have detached from the language itself. Emigrating from Germany in the 1700s, these families settled for over a hundred years along the Volga Region of Imperial Russia. Subsequently, many descendants of these settlers immigrated to the Americas in the 1800-1900s. Identifying neither as German nor Russian, they called themselves Wolgadeutche (Volga Germans). During their time in Russia, the German language was maintained relatively homogenously, yet the use and status of their heritage language diverged considerably upon settlement across the Americas. Data shows that specific conditions, such as community isolation, size, religion, location as well as language policy established prior to and following the Volga German immigration to North America have had a substantial impact on the maintenance of their heritage language—causing complete loss in some areas and peripheral use or even full rebirth in others. These past conditions combined with the family accounts correlate directly with the general attitudes and ideologies of the descendants toward their heritage language. Data also shows that in many locations, despite a strong presence of German within the linguistic landscape, minimal to no German is spoken nor understood; the attitude toward the language is indifferent while a staunch holding to the heritage is maintained and boasted. Data for this study was gathered from historical accounts, archived records and newspapers, and published biographies as well as from formal interviews with second- and third-generation descendants of Volga German immigrants conducted in Oregon and Kansas. Through the interviews, members of the community have shared and provided their family genealogies as well as biographies published by family members. These have helped to trace their relatives back to specific locations, thus allowing for comparisons within the same families residing in distinctly different areas of North America. This study is part of a larger ongoing project which researches the immigration of Volga and Black Sea Germans to North America and diachronically examines the over-arching sociological factors which have directly impacted the maintenance, loss, or rebirth of their heritage language. This project follows specific families who settled in areas of Colorado, Kansas, Nebraska, Illinois, Minnesota, North and South Dakota, Saskatchewan, and Manitoba, and who later had relatives move west to areas of Oregon and Washington State. Interviews for the larger project will continue into the following year.

Keywords: heritage language, immigrant language, language change, language contact, linguistic landscape, Volga Germans, Wolgadeutsche

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Authors: Gumilar Hadiningrat, Stewart Barr, Jo Little

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In Indonesia, the majority of those who manage food waste are women. It is Indonesian culture that women act as household managers. Therefore, women as household managers hold an important role in reducing food waste within households. Meanwhile, in the community, women’s organisations are some of the most active organisations dealing with food waste. Food waste has an increasing profile and is the subject of much global attention and have economic, social and environmental impacts. Reducing food waste will improve future food availability in the context of global population growth and increasing resource scarcity. The aim of this research is to investigate women’s experience and understanding of dealing with food waste in the household and in the community. The research will use an inductive approach using in-depth qualitative methods. In terms of data collection, two methods will be used - questionnaire and interviews. All in all, it could be claimed that women, both within the household and the community in Indonesia, hold an important role in dealing with food waste.

Keywords: community waste management, food waste, gender, household waste, waste management

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Authors: Sherly M. A., Varsha Vijaykumar, Subhankar Karmakar, Terence Chan, Christian Rau

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This study aims at proposing an indicator-based framework for assessing social vulnerability of any coastal megacity to floods. The final set of indicators of social vulnerability are chosen from a set of feasible and available indicators which are prepared using a Geographic Information System (GIS) framework on a smaller scale considering 1-km grid cell to provide an insight into the spatial variability of vulnerability. The optimal weight for each individual indicator is assigned using data envelopment analysis (DEA) as it avoids subjective weights and improves the confidence on the results obtained. In order to de-correlate and reduce the dimension of multivariate data, principal component analysis (PCA) has been applied. The proposed methodology is demonstrated on twenty four wards of Mumbai under the jurisdiction of Municipal Corporation of Greater Mumbai (MCGM). This framework of vulnerability assessment is not limited to the present study area, and may be applied to other urban damage centers.

Keywords: urban floods, vulnerability, data envelopment analysis, principal component analysis

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Authors: Youn-Sung Kim, Mi-Sung Kim, Jae-Kun Lee

Abstract:

This paper deals with the accelerated life cycle test method of the motor for home appliances that demand high reliability. Life Cycle of parts in home appliances also should be 10 years because life cycle of the home appliances such as washing machine, refrigerator, TV is at least 10 years. In case of washing machine, the life cycle test method of motor is advanced for 3000 cycle test (1cycle = 2hours). However, 3000 cycle test incurs loss for the time and cost. Objectives of this study are to reduce the life cycle test time and the number of test samples, which could be realized by using acceleration factor for the test time and reduction factor for the number of sample.

Keywords: accelerated life cycle test, motor reliability test, motor for washing machine, BLDC motor

Procedia PDF Downloads 627

Authors: Mohamed M. Shahin

Abstract:

This study investigated the design of the pile foundation to support heavy structures-especially bridges for highways-in the Sahara, which contains many dunes of medium dense sand in different levels, where the foundation is supposed to be piles. The base resistance of smooth model pile groups in sand under static loading is investigated experimentally in a pile soil test apparatus. Improvement were made to the sand around the piles in order to increase the shaft resistance of the single pile and the pile groups, and also base resistance especially for the central pile in pile groups. The study outlines the behaviour of a single-pile, 4-, 5-, and 9- pile groups arranged in a doubly symmetric [square] layout with different embedment lengths and pile spacing in loose dry sand [normal] and dense dry sand [compacted] around the piles. This study evaluate the variation of the magnitude and the proportion of end bearing capacity of individual piles in different pile groups. Also to investigate the magnitude of the efficiency coefficient in the case of different pile groups.

Keywords: pile group, base resistance, efficiency coefficient, pile spacing, pile-soil interaction

Procedia PDF Downloads 357

Authors: Hyon I. Paek, Sang Rim Kim, Hyon A. Ryu

Abstract:

In functional linear regression, one typical problem is to reduce dimension. Compared with multivariate linear regression, functional linear regression is regarded as an infinite-dimensional case, and the main task is to reduce dimensions of functional response and functional predictors. One common approach is to adapt functional principal component analysis (FPCA) on functional predictors and then use a few leading functional principal components (FPC) to predict the functional model. The leading FPCs estimated by the typical FPCA explain a major variation of the functional predictor, but these leading FPCs may not be mostly correlated with the functional response, so they may not be significant in the prediction for response. In this paper, we propose a supervised functional principal component analysis method for a functional response model with FPCs obtained by considering the correlation of the functional response. Our method would have a better prediction accuracy than the typical FPCA method.

Keywords: supervised, functional principal component analysis, functional response, functional linear regression

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Authors: Fstemeh Rais Esmaili, Ehsan Ranjbar

Abstract:

Pedestrian streets as one type of urban public spaces have an important role in improving the quality of urban life. In Iran, planning and designing of pedestrian streets is in its primary steps. In spite of starting this approach in Iran, and designing several pedestrian streets, there are still not organized studies about quality assessment of pedestrian streets. As a result, the strength and weakness points of the initial experiences have not been utilized. This inattention to quality assessment have caused designing pedestrian streets to be limited to just vehicles traffic control and preliminary actions like paving; so that, special potentials of pedestrian streets for creating social, livable and dynamic public spaces have not been used. This article, as an organized study about quality assessment of pedestrian streets in Iran, tries to reach two main goals: first, introducing a framework for quality assessment of pedestrian streets in Iran, and second, creating a context for improving the quality of pedestrian streets especially for further experiences. The main research methods are description and context analyzing. With respect to comparative analysis of ideas about quality, considering international and local case studies and analyzing existing condition of Saf Pedestrian Street, a particular model for quality assessment has been introduced. In this model, main components and assessment criteria have been presented. On the basis of this model, questionnaire and checklist for assessment have been prepared. The questionnaire and interview have been used to assess qualities which are in direct contact with people and the checklist has been used for analyzing visual qualities by authors through observation. Some results of questionnaire and checklist show that 7 of 11 primary components, diversity, flexibility, cleanness, legibility and imaginably, identity, livability, form and physical setting are rated low and very low in quality degree. Three components, efficiency, comfort and distinctiveness, have medium and low quality degree and one component, access, linkage and permeability has high quality degree. Therefore, based on implemented analyzing process, Saf Pedestrian Street needs to be improved and these quality improvement priorities are determined based on presented criteria. Adaption of final results with existing condition illustrates the shortage of services for satisfying user’s needs, inflexibility and impossibility of using spaces in various times, lack of facilities for different climatic conditions, lack of facilities such as drinking fountain, inappropriate designing of existing urban furniture like garbage cans, and creating pollution and unsuitable view, lack of visual attractions, neglecting disabled persons in designing entrances, shortage of benches and their undesirable designing, lack of vegetation, absence of special characters making it different from other streets, preventing people taking part in the space causing lack of affiliation, lack of appropriate elements for leisure time and lack of exhilaration in the space. On the other hand, these results present high access and permeability, high safety, less sound pollution and more relief, comfortable movement along the way due to suitable pavement and economic efficiency, as the strength points of Saf pedestrian street.

Keywords: pedestrian streets, quality assessment, quality criteria, Saf Pedestrian Street

Procedia PDF Downloads 252

Authors: O. Gsib, U. Peirera, C. Egles, S. A. Bencherif

Abstract:

In skin regenerative medicine, one of the critical issues is to produce a three-dimensional scaffold with optimized porosity for dermal fibroblast infiltration and neovascularization, which exhibits high mechanical properties and displays sufficient wound healing characteristics. In this study, we report on the synthesis and characterization of macroporous sequential interpenetrating polymer networks (IPNs) combining skin wound healing properties of fibrin with the excellent physical properties of polyethylene glycol (PEG). Fibrin fibers serve as a provisional biologically active network to promote cell adhesion and proliferation while PEG provides the mechanical stability to maintain the entire 3D construct. After having modified both PEG and Serum Albumin (used for promoting enzymatic degradability) by adding methacrylate residues (PEGDM and SAM, respectively), Fibrin/PEGDM-SAM sequential IPNs were synthesized as follows: Macroporous sponges were first produced from PEGDM-SAM hydrogels by a freeze-drying technique and then rehydrated by adding the fibrin precursors. Environmental Scanning Electron Microscopy (ESEM) and Confocal Laser Scanning Microscopy (CLSM) were used to characterize their microstructure. Human dermal fibroblasts were cultivated during one week in the constructs and different cell culture parameters (viability, morphology, proliferation) were evaluated. Subcutaneous implantations of the scaffolds were conducted on five-week old male nude mice to investigate their biocompatibility in vivo. We successfully synthesized interconnected and macroporous Fibrin/PEGDM-SAM sequential IPNs. The viability of primary dermal fibroblasts was well maintained (above 90%) after 2 days of culture. Cells were able to adhere, spread and proliferate in the scaffolds suggesting the suitable porosity and intrinsic biologic properties of the constructs. The fibrin network adopted a spider web shape that covered partially the pores allowing easier cell infiltration into the macroporous structure. To further characterize the in vitro cell behavior, cell proliferation (EdU incorporation, MTS assay) is being studied. Preliminary histological analysis of animal studies indicated the persistence of hydrogels even after one-month post implantation and confirmed the absence of inflammation response, good biocompatibility and biointegration of our scaffolds within the surrounding tissues. These results suggest that our Fibrin/PEGDM-SAM IPNs could be considered as potential candidates for dermis regenerative medicine. Histological analysis will be completed to further assess scaffold remodeling including de novo extracellular matrix protein synthesis and early stage angiogenesis analysis. Compression measurements will be conducted to investigate the mechanical properties.

Keywords: fibrin, hydrogels for dermal reconstruction, polyethylene glycol, semi-interpenetrating polymer network

Procedia PDF Downloads 231

Authors: Seok-Hyeon Park, Joon-Hong Park, Mok-Tan-Ahn, Seong-Hun Ha

Abstract:

Clad Pipe is made of a different kind of material, which is different from the internal and external materials, for the corrosive crude oil transportation tube. Most of the clad pipes are produced by hot rolling. However, problems arise due to high product prices and excessive process numbers. Therefore, in this study, the hot drawing process with excellent product cost, process number and productivity is applied. Due to the nature of the drawing process, the shape of the mold greatly influences the formability of the material and the bonding pressure of the two materials because it is a process of drawing the material to the die and reducing the cross-sectional area. Also, in case of hot drawing, if the mold shape is not suitable due to the increased fluidity of the material, it may cause problems such as tearing and stretching. Therefore, in this study, we try to find the shape of the mold which suppresses the occurrence of defects in the hot drawing process and maximizes the bonding pressure between the two materials through the mold shape optimization design by FEM analysis.

Keywords: clad pipe, hot drawing, bonding pressure, mold shape

Procedia PDF Downloads 294