Search results for: critical speeds

Authors: Y. J. Wang, C. Q. Ru

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A key issue of cohesive zone models is how to determine the cohesive zone model (CZM) parameters based on real material test data. In this paper, uniaxial nominal stress-strain curve (SS curve) is used to determine two key parameters of a cohesive zone model: the maximum traction and the area under the curve of traction-separation law (TSL). To this end, the true SS curve is obtained based on the nominal SS curve, and the relationship between the nominal SS curve and TSL is derived based on an assumption that the stress for cracking should be the same in both CZM and the real material. In particular, the true SS curve after necking is derived from the nominal SS curve by taking the average of the power law extrapolation and the linear extrapolation, and a damage factor is introduced to offset the true stress reduction caused by the voids generated at the necking zone. The maximum traction of the TSL is equal to the maximum true stress calculated based on the damage factor at the end of hardening. In addition, a simple specimen is simulated by Abaqus/Standard to calculate the critical J-integral, and the fracture energy calculated by the critical J-integral represents the stored strain energy in the necking zone calculated by the true SS curve. Finally, the CZM parameters obtained by the present method are compared to those used in a previous related work for a simulation of the drop-weight tear test.

Keywords: dynamic fracture, cohesive zone model, traction-separation law, stress-strain curve, J-integral

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Authors: James Moir

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Recent evidence suggests that academic staff face difficulties in applying new technologies as a means of assessing higher order assessment outcomes such as critical thinking, problem solving and creativity. Although higher education institutional mission statements and course unit outlines purport the value of these higher order skills there is still some question about how well academics are equipped to design curricula and, in particular, assessment strategies accordingly. Despite a rhetoric avowing the benefits of these higher order skills, it has been suggested that academics set assessment tasks up in such a way as to inadvertently lead students on the path towards lower order outcomes. This is a controversial claim, and one that this papers seeks to explore and critique in terms of challenging the conceptual basis of assessing higher order skills through new technologies. It is argued that the use of digital media in higher education is leading to a focus on students’ ability to use and manipulate of these products as an index of their flexibility and adaptability to the demands of the knowledge economy. This focus mirrors market flexibility and encourages programmes and courses of study to be rhetorically packaged as such. Curricular content has become a means to procure more or less elaborate aggregates of attributes. Higher education is now charged with producing graduates who are entrepreneurial and creative in order to drive forward economic sustainability. It is argued that critical independent learning can take place through the democratisation afforded by cultural and knowledge digitization and that assessment needs to acknowledge the changing relations between audience and author, expert and amateur, creator and consumer.

Keywords: higher education, curriculum, new technologies, assessment, higher order skills

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Authors: Sukhdeep Singh Gill, Gurbhinder Singh Brar

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In recent years, friction stir welding (FSW) has attracted the main attention of the concerned researcher especially in case of joining of nonferrous alloys like aluminum and magnesium due to its unmatchable properties with respect to other welding techniques. Friction stir welding is a solid state welding process which is most suitable for the welding of nonferrous alloys, especially aluminum and magnesium alloys. Aluminum and magnesium alloys are widely used for structural applications of all types of automobiles due to their superior mechanical properties with their low density. This paper deals with the critical review of the different properties (like tensile strength, microhardness, impact strength, corrosion resistance, and metallurgical investigation on SEM) obtained by the FSW of aluminum and magnesium alloys. After a critical review of the existing published literature on concerned topics, all the properties of welding joins are compared in the tabulated manner to optimize the selection of materials and FSW parameters according to mechanical and tribological properties. Different tool designs used for the FSW process are also thoroughly studied, and the influence of the design of the tool used in FSW on the different properties has also been incorporated in this paper. It has been observed from the existing published literature that FSW is the most effective and practical technique for joining the non ferrous alloys especially aluminum and magnesium alloys, and among the different FSW tools, left hand threaded tri-flute (LHTTF) tool is best for the welding of non ferrous alloys like aluminum and magnesium alloys which gives the superior mechanical properties to welding joint.

Keywords: aluminum, friction stir welding, magnesium, structural applications, tool design

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Authors: Owus Mathias Ibearugbulem

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The study presents Euler-Bernoulli’s approach for buckling analysis of thick rectangular plates using alternative I refined theory. No earlier study, to the best knowledge of the author, based on the literature available to this research, applied Euler-Bernoulli’s approach in the alternative I refined theory for buckling analysis of thick rectangular plates. In this study, basic kinematics and constitutive relations for thick rectangular plates are employed in the differential equations of equilibrium of stresses in a deformable elemental body to obtain alternative I governing differential equations of thick rectangular plates and the corresponding compatibility equations. Solving these equations resulted in a general deflection function of a thick rectangular plate. Using this function and satisfying the boundary conditions of three plates, their peculiar deflection functions are obtained. Going further, the study determined the non-dimensional critical buckling loads of the six plates. Values of the non-dimensional critical buckling load from the present study are compared with those from a three-dimensional buckling analysis of a thick plate. The highest percentage difference recorded for the plates: all edges simply supported (ssss), all edges clamped (cccc) and adjacent edges clamped with the other edges simply supported (ccss) are 3.31%, 5.57% and 3.38% respectively.

Keywords: Euler-Bernoulli, buckling, alternative I, kinematics, constitutive relation, governing differential equation, compatibility equation, thick plate

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Authors: Ziba Talaeizadeh, Taghi Ebadi

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Hospitals and medical centers generate a wide array of infectious waste on a daily basis, leading to pressing environmental concerns associated with proper disposal. Disposable plastic items and spun-bond clothing, commonly made from polypropylene, pose a significant risk of disease transmission, necessitating specialized waste management strategies. Incorporating these materials into bituminous asphalt production offers a potential solution, as it can modify asphalt mixtures and reduce susceptibility to cracking. This study aims to assess the crack resistance of asphalt mixtures modified with hospital spun-bond waste. Asphalt mixtures were prepared using the Marshall method, with spun-bond waste added in varying proportions (5% to 20%). The Semi-Circular Bending (SCB) test was conducted to evaluate asphalt fracture behavior under Mode I loading at controlled speeds of 5, 20, and 50 millimeters per minute and an average temperature of 25°C. Parameters such as fracture energy (FE) and Crack Resistance Index (CRI) were quantified. The results indicate that the addition of 10% to 15% spun-bond polypropylene polymer enhances the performance of the modified mixture, resulting in an 18% increase in fracture energy and an 11% reduction in cracking stiffness compared to the control sample. Further investigations involving factors like compaction level, bitumen type, and aggregate grading are recommended to address medical waste management and mitigate asphalt pavement cracking issues.

Keywords: asphalt cracking, hospital waste, semi-circular bending test, spun-bond

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Authors: Gina Cynthia Raphita Hasibuan

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The housing sector in Indonesia is in critical condition where majority of low-income citizens live in substandard dwellings, and the number housing backlog is increasing every year. The housing problem becomes more urgent when the term 'sustainability' is considered, and sustainable affordable housing is yet to gain its successful implementation. Global urbanization develops fastest in developing countries like Indonesia where informal settlements are rapidly escalating, hence, making sustainable affordable housing strategies very critical in this context. The problem in developing countries like Indonesia lies on the institutional capacity of newly-established local governments having greater power to determine a development policy but apparently still lacking institutional capability and coordination with the central government and collaborative governance are still not established yet. The concept of upgrading informal settlements are seen changed over time and inconsistent. Despite much research on theme such as sustainable housing concept within Indonesian context, there has been a dearth of research examining the role of collaborative governance, as the current approach still shows fragmented approach between the stakeholders and the lack of community participation as the end user, and thus this research attempts to fill the gap on the aforementioned problems. By using case study with multi-methods conducted in Jakarta, this research has an overall aim to critically assess the role of collaborative governance in addressing sustainable affordable housing in Indonesia and to understand informal settlements and interventions in Indonesia rather than imposing a framework from western perspectives.

Keywords: affordable housing, collaborative governance, sustainability, urban planning

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Authors: Hana A. Jameel Alsaeed, Rayyan Ibrahim Khaleel, Hanaa Hussein Mukhlif

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Background: Contamination in Iraq's hospitals is a localized problem with high rates of disease And deaths that mainly affect poor areas. Thus, this study aims to evaluate hospital infections in the city of Mosul and to identify the etiology. So to assess environmental infection prevention in pediatric wards and newborn critical care units in Mosul city. Methods: The present study is a cross-sectional hospital based in Mosul-Iraq between (10th February to 1st April 2022). Purposive sample of 60 nurses from neonatal intensive care units and pediatric wards in three pediatric teaching hospitals in Mosul city; Data was gathered using a questionnaire created by the researchers after reviewing previous studies. Results: The study showed that the majority of the study infection prevention and control policy isn't available in 46.7% of departments, and 45% of hospital workers in Iraq don't know if there is an Iraqi version of it. 70% of the study group had participated in an infection control training program. Conclusions: In the majority of samples 55% of respondents to the study claimed not to be aware of these rules. 60% of the study's participants had never attended a course on infection prevention and control, according to the study's findings on education and training programs. In the neonatal and critical care unit, nurses' skill levels, years of experience, and actual duties varied by wide statistically significant differences.

Keywords: pediatric, infection control, assessment, mosul city

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Authors: Akachi Odoemene

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Climate change and land grabbing are tightly interconnected in ways that are both diverse and complex. They have impacted each other in significant ways too. Both phenomena are not only a political reality, but have diverse dire implications, especially for food and livelihood security of vulnerable populations in developing economies. The critical nexus and interactions of climate change and land grabbing remain one of the challenges of sustainable development in modern times. The nuanced understanding of the nexus, importance and implications of climate change and land grabbing are the primary focus of this chapter. It begins with conceptual clarifications, particularly arguing that the absence of some important principles of engagement underline and define a land grab. It also analyses and notes a good number of contemporary land deals as 'one-sided', in which wealthy entities connive with local elites to exploit and disposes rural poor populations. The paper not only examines both global and local factors that drive land grabbing and, in some cases, their connections with the incidence of climate change, but also explores their crucial links with such sector as agriculture. It is argued and exhibited in the paper why certain societies are susceptible to the incidence of climate change and land grabbing, while the overall consequences of these phenomena on the affected societies are further interrogated. The paper concludes that the lack of political will by global political leaders to effectively combat and resolve critical issues associated with both climate change and land grabbing remains a daunting challenge. It notes that these phenomena – climate change and land grabbing – if not abated, will certainly become another set of global tragic episodes to be regretted in the future.

Keywords: climate change, land grabbing, global governance, developing economies

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Authors: Samson Olasunkanmi Oluga, Teh Chee Send, Gerard Sagaya Raj Rajo

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It is ironical that the national anthems of many nations that are in the forefront of the global condemnation of violence of all forms have portions or expressions that propagate various forms of linguistic violence which advocate attacking opponents, going to war, shedding blood and sacrificing lives. These diametrically contradict contemporary yearnings for global tranquility and the ideals of the United Nations established for the maintenance of international peace and harmony aimed at making the world a safe haven for all and sundry. The linguistic violence of many national anthems is manipulatively constructed /presented via the instrumentality of the figurative or rhetorical language. This helps to linguistically embellish the violent ideas communicated and makes them sound somehow better or logical to the target audience with the intention of cognitively manipulating them to accept or rationalize such violent ideas. This paper, therefore, presents the outcome of a linguistic exploration/examination of national anthems which reveals elements or cases manipulative figurative linguistic violence in the anthems of twenty-one (21) nations. The paper details a Socio-Cognitive Critical Discourse Analysis of the manipulative figures of comparison, contrast, indirectness, association and sound used to convey the linguistic violence of the identified national anthems. Finally, the paper advocates the need for linguistic overhaul of affected anthems so that the language of anthems which epitomize nations can be pacific and in tandem with contemporary global trends.

Keywords: national anthems, linguistic violence, figurative language, cognitive, manipulation, CDA

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Authors: Ruth Muturi Wanjiku

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HIV/AIDS in Kenya for unborn and young kids. HIV/AIDS is a significant health concern in Kenya, with an estimated 1.5 million people living with the disease. Unfortunately, many of these individuals are unaware of their HIV status, and the disease continues to spread among the population or unborn kids. HIV/AIDS can be transmitted from an infected mother during pregnancy, childbirth, or breastfeeding. However, with early testing and treatment, the risk of mother-to-child transmission can be significantly reduced. Therefore, it is crucial for pregnant women to get tested and receive appropriate medical care. For young kids, HIV/AIDS education is critical to preventing the spread of the disease. It is essential to teach children about the importance of safe sex practices, avoiding risky behaviors such as sharing needles and getting tested regularly. Additionally, children should be taught about the stigma surrounding HIV/AIDS and encouraged to treat individuals living with the disease with compassion and respect. In conclusion, HIV/AIDS is a significant health concern in Kenya that affects individuals of all ages. For unborn kids, early testing and treatment are critical to reducing the risk of mother-to-child transmission. For young kids, education about HIV/AIDS and safe sex practices is essential to preventing the spread of the disease and reducing stigma. It is essential to promote awareness and encourage individuals to get tested and seek medical care if they believe they may be infected with HIV/AIDS.

Keywords: AIDS, HIV, children, pregnant

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Authors: Jinee Gogoi, Som K. Sharma, Kalyan Bhuyan

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The atmospheric layers are coupled to each other with the different dynamical, electrical, radiative and chemical processes. A large scale thermodynamical phenomenon in winter polar regions which affects the middle atmosphere vigorously is Sudden Stratospheric Warming (SSW). Two major SSW events were occurred during 1998-1999; one in December 1998 which is associated with vortex displacement and another in February- March 1999 associated with vortex splitting. Lidar study of these two major events from Mt. Abu (24.36⁰N, 72.45⁰E, ~1670 m amsl) has shown that though SSWs are mostly observed over high and mid latitudes, their effects can also be seen over India. We have studied ionospheric variations (primarily fₒF₂, h’F and hpF₂) over Ahmedabad (23.1⁰N, 72.58⁰E) during these events. Ionospheric disturbances have been found after four-five days of peak temperature. An increase (decrease) in critical frequency (fₒF₂) during morning (afternoon) has been noticed which may be in response to the updrift (down drift). Effects are stronger during displacement event (1998) than during the splitting event (1999). We have also studied some recent events occurred during 2006 (January), 2009 (January) and 2013 (January) using temperature data from Sounding of Atmosphere using Broadband Emission Radiometry (SABER) satellite. Though some modeling work supports the hypothesis that planetary waves are responsible for atmosphere-ionosphere coupling, there is still more significant works to do to understand how exactly the coupling can take place.

Keywords: sudden stratospheric warming (SSW), polar vortex, ionosphere, critical frequency

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Authors: Javier Navarro Garcia, Narciso Vazquez Carretero

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Eurocode 1, part 1-4, wind actions, includes in its article 1.5 the possibility of using numerical calculation methods to obtain information on the loads acting on a building. On the other hand, the analysis using computational fluids dynamics (CFD) in aerospace, aeronautical, and industrial applications is already in widespread use. The application of techniques based on CFD analysis on the building to study its aerodynamic behavior now opens a whole alternative field of possibilities for civil engineering and architecture; optimization of the results with respect to those obtained by applying the regulations, the possibility of obtaining information on pressures, speeds at any point of the model for each moment, the analysis of turbulence and the possibility of modeling any geometry or configuration. The present work compares the results obtained on a building, with respect to its aerodynamic behavior, from a mathematical model based on the analysis by CFD with the results obtained by applying Eurocode1, part1-4, wind actions. It is verified that the results obtained by CFD techniques suppose an optimization of the wind action that acts on the building with respect to the wind action obtained by applying the Eurocode1, part 1-4, wind actions. In order to carry out this verification, a 45m high square base truncated pyramid building has been taken. The mathematical model on CFD, based on finite volumes, has been calculated using the FLUENT commercial computer application using a scale-resolving simulation (SRS) type large eddy simulation (LES) turbulence model for an atmospheric boundary layer wind with turbulent component in the direction of the flow.

Keywords: aerodynamic, CFD, computacional fluids dynamics, computational mechanics

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Authors: Guermache Ahmed Chafik, Khelfellah Ismail, Ait-Ali Takfarines

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The Savonius vertical axis wind turbine is characterized by sufficient starting torque at low wind speeds, simple design and does not require orientation to the wind direction; however, the developed power is lower than other types of wind turbines such as Darrieus. To increase these performances several studies and researches have been developed, such as optimizing blades shape, using passive controls and also minimizing power losses sources like the resisting torque due to friction. This work aims to estimate the performance of a Savonius wind turbine introducing a User Defined Function to the CFD model analyzing resisting torque. This User Defined Function is developed to simulate the action of the wind speed on the rotor; it receives the moment coefficient as an input to compute the rotational velocity that should be imposed on computational domain rotating regions. The rotational velocity depends on the aerodynamic moment applied on the turbine and the resisting torque, which is considered a linear function. Linking the implemented User Defined Function with the CFD solver allows simulating the real functioning of the Savonius turbine exposed to wind. It is noticed that the wind turbine takes a while to reach the stationary regime where the rotational velocity becomes invariable; at that moment, the tip speed ratio, the moment and power coefficients are computed. To validate this approach, the power coefficient versus tip speed ratio curve is compared with the experimental one. The obtained results are in agreement with the available experimental results.

Keywords: resistant torque modeling, Savonius wind turbine, user-defined function, vertical axis wind turbine performances

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Authors: Dragana Gnjatovic

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Assessment is a burning topic in education policy and practice due to measurement-driven neoliberal agendas of quality and standardisation of assessment practice through high stakes standardised testing systems that are now influencing early childhood education. This paper presents a collaborative, arts-informed action research project which places children at the centre of their learning, with assessment as an integral part of play-based learning processes. It aims to challenge traditional approaches to assessment that are often teacher-led and decontextualised from the processes of learning through exploring approaches where children's voices are central, and their creative arts expressions are used to assess learning and development. The theoretical framework draws on Vygotsky's sociocultural theory and Freire's critical pedagogy, which indicate the importance of socially constructed reality where knowledge is the result of collaboration between children and adults. This reality perceives children as competent agents of their own learning processes. An interpretive-constructivist and critical-transformative paradigm underpin collaborative action research in a three to five-year-old setting, where creative methods like storytelling, play, drama, drawing are used to assess children's learning. As data collection and analysis are still in process, this paper will present the methodology and some data vignettes, with the aim of stimulating discussion about innovation in assessment and contribution of the collaborative enquiry in the field of Early Childhood Education and Care.

Keywords: assessment for learning, creative methodologies, collaborative action research, early childhood education and care

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Authors: Dunwen Zuo, Yongfang Deng, Bo Song

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An attempt is made here to measure the forces of three directions, under conditions of different feed speeds, different tilt angles of tool and without or with the pin on the tool, by using octagonal ring dynamometer in the AA2024 aluminum FSJ (Friction Stir Joining) process, and investigate how four main factors influence forces in the FSJ process. It is found that, high feed speed lead to small feed force and small lateral force, but high feed speed leads to large feed force in the stable joining stage of process. As the rotational speed increasing, the time of axial force drop from the maximum to the minimum required increased in the push-up process. In the stable joining stage, the rotational speed has little effect on the feed force; large rotational speed leads to small lateral force and axial force. The maximum axial force increases as the tilt angle of tool increases at the downward movement stage. At the moment of start feeding, as tilt angle of tool increases, the amplitudes of the axial force increasing become large. In the stable joining stage, with the increase of tilt angle of tool, the axial force is increased, the lateral force is decreased, and the feed force almost unchanged. The tool with pin will decrease axial force in the downward movement stage. The feed force and lateral force will increase, but the axial force will reduced in the stable joining stage by using the tool with pin compare to by using the tool without pin.

Keywords: FSJ, force factor, AA2024 aluminum, friction stir joining

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Authors: Ali A. Al-Jazaairry, Tahsin T. Sabbagh

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One of the important concerns within the field of geotechnical engineering is the presence of cavities in soils. This present work is an attempt to understand the behaviour of strip footing subjected to inclined load and constructed on cavitied soil. The failure mechanism of strip footing located above such soils was studied analytically. The capability of analytical model to correctly expect the system behaviour is assessed by carrying out verification analysis on available studies. The study was prepared by finite element software (PLAXIS) in which an elastic-perfectly plastic soil model was used. It was indicated, from the results of the study, that the load carrying capacity of foundation constructed on cavity can be analysed well using such analysis. The research covered many foundation cases, and in each foundation case, there occurs a critical depth under which the presence of cavities has shown minimum impact on the foundation performance. When cavities are found above this critical depth, the load carrying capacity of the foundation differs with many influences, such as the location and size of the cavity and footing depth. Figures involving the load carrying capacity with the affecting factors studied are presented. These figures offer information beneficial for the design of strip footings rested on underground cavities. Moreover, the results might be used to design a shallow foundation constructed on cavitied soil, whereas the obtained failure mechanisms may be employed to improve numerical solutions for this kind of problems.

Keywords: axial load, cavity, inclined load, strip footing

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Authors: Monika Šípová, Daniela Marušáková, Claudia Aparicio

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New sources and ways of producing energy are still seeking, and one of the sustainable ways is Generation IV nuclear reactors. The supercritical water-cooled reactor is one of the six nuclear reactors of Generation IV, and as a consequence of the development of light water, reactors seem to be the most perspective. Thus, materials usually used in light water reactors are also tested under the expected operating conditions of the supercritical water-cooled reactor. Austenitic stainless steel 08Cr18Ni10Ti is widely used in the eastern types of light water nuclear power plants. Therefore, specimens of 08Cr18Ni10Ti were exposed to conditions close to the pseudo-critical point of water and high-temperature supercritical water. The description and evaluation of the corrosion behaviour of austenitic stainless steel have been done based on the results of X-ray diffraction in combination with energy dispersive spectroscopy and electron backscatter diffraction. Thus, significant differences have been found in the structure and composition of oxides formed depending on the temperature of exposure. The high temperature of supercritical water resulted in localised form of corrosion in contrast to the thin oxide layer of 1 µm present on the surface of specimens exposed close to the pseudo-critical point of water. The obtained results are important for further research as the supercritical water can be successfully used as a coolant for small modular reactors, which are currently of interest.

Keywords: localised corrosion, supercritical water, stainless steel, electron backscatter diffraction

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Authors: Miraji H. Mohamed

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The purpose of this study is to critique ‘radicalisation’ and more particularly ‘youth radicalisation’ by exploring its usage in online newspapers. ‘Radicalisation’ and ‘extremism’ have become the most common terms in terrorism studies since the 9/11 attacks. Regardless of the geographic location, when the word terrorism is used the terms ‘radicalisation’ and ‘extremism’ always follow to attempt to explore the journey of the perpetrators towards violence. These terms have come to represent a discourse of dominantly pejorative traits often used to describe spaces, groups, and processes identified as problematic. Even though ambiguously defined they feature widely in government documents, political statements, news articles, academic research, social media platforms, religious gatherings, and public discussions. Notably, ‘radicalisation’ and ‘extremism’ have been closely conflated with the term youth to form ‘youth radicalisation’ to refer to a discourse of ‘youth at risk’. The three terms largely continue to be used unquestioningly and interchangeably hence the reason why they are placed in single quotation marks to deliberately question their conventional usage. Albeit this comes timely in the Kenyan context where there has been a proliferation of academic and expert research on ‘youth radicalisation’ (used as a neutral label) without considering the political, cultural and socio-historical contexts that inform this label. This study seeks to draw these nuances by employing a genealogical approach that historicises and deconstructs ‘youth radicalisation’; and by applying a Discourse-Historical Approach (DHA) of Critical Discourse Analysis to analyse Kenyan online newspaper - The Daily Nation between 2015 and 2018. By applying the concept of representation to analyse written texts, the study reveals that the use of ‘youth radicalisation’ as a discursive strategy disproportionately affects young people especially those from cultural/ethnic/religious minority groups. Also, the ambiguous use of ‘radicalisation’ and ‘youth radicalisation’ by the media reinforces the discourse of ‘youth at risk’ which has become the major framework underpinning Countering Violent Extremism (CVE) interventions. Similarly, the findings indicate that the uncritical use of ‘youth radicalisation’ has been used to serve political interests; and has become an instrument of policing young people, thus contributing to their cultural shaping. From this, it is evident that the media could thwart rather than assist CVE efforts. By exposing the political nature of the three terms through evidence-based research, this study offers recommendations on how critical reflective reporting by the media could help to make CVE more nuanced.

Keywords: discourse, extremism, radicalisation, terrorism, youth

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Authors: Ghanim A. Bekr

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Project success is what must be done for the project to be acceptable to the client, stakeholders and end-users who will be affected by the project. The study of project success and the critical success factors (CSFs) are the means adopted to improve the effectiveness of project. This research is conducted to make an attempt to identify which variables influence the success of project implementation. This study has selected, through an extensive literature review and interviews, (83) factors categorized in (7) groups that the questionnaire respondents were asked to score. The responses from 66 professionals with an average of 15 years of experience in different types of construction projects in Jordan were collected and analyzed using SPSS and most important factors for success for various success criteria are presented depending on the relative importance index to rank the categories. The research revealed the significant groups of factors are: Client related factors, Contractor’s related factors, Project Manager (PM) related factors, and Project management related factors. In addition the top ten sub factors are: Assertion of the client towards short time of the project, availability of skilled labor, Assertion of the client towards high level of the quality, capability of the client in taking risk, previous experience of the PM in similar projects, previous experience of the contractor in similar projects, decision making by the client/ the client’s representative at the right time, assertion of client towards low cost of project, experience in project management in previous projects, and flow of the information among parties. The results would be helpful to construction project professionals in taking proactive measures for successful completion of construction projects in Jordan.

Keywords: construction projects, critical success factors, Jordan, project success

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Authors: Nadir A. Carreon, Christa Sonderer, Aakarsh Rao, Roman Lysecky

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With the advent of complex software and increased connectivity, the security of life-critical medical devices is becoming an increasing concern, particularly with their direct impact on human safety. Security is essential, but it is impossible to develop completely secure and impenetrable systems at design time. Therefore, it is important to assess the potential impact on the security and safety of exploiting a vulnerability in such critical medical systems. The common vulnerability scoring system (CVSS) calculates the severity of exploitable vulnerabilities. However, for medical devices it does not consider the unique challenges of impacts to human health and privacy. Thus, the scoring of a medical device on which human life depends (e.g., pacemakers, insulin pumps) can score very low, while a system on which human life does not depend (e.g., hospital archiving systems) might score very high. In this paper, we propose a medical vulnerability scoring system (MVSS) that extends CVSS to address the health and privacy concerns of medical devices. We propose incorporating two new parameters, namely health impact, and sensitivity impact. Sensitivity refers to the type of information that can be stolen from the device, and health represents the impact on the safety of the patient if the vulnerability is exploited (e.g., potential harm, life-threatening). We evaluate fifteen different known vulnerabilities in medical devices and compare MVSS against two state-of-the-art medical device-oriented vulnerability scoring systems and the foundational CVSS.

Keywords: common vulnerability system, medical devices, medical device security, vulnerabilities

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Authors: Imtiaz Ali, Imam Mansoor

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Investigations as a part of the academic study were undertaken to identify and evaluate the significant risks associated with the construction of K-span buildings in the region of UAE. Primary field data was collected through questionnaires obtaining specific open and close-ended questions from carefully selected construction firms, civil engineers and, construction manager regarding risks associated to K-span building construction. Historical data available for other regions of the same construction technique was available which was compared for identifying various non-critical and critical risk parameters by comparative evaluation techniques to come up with important risks and potential sources for their control and minimization in K-Span buildings that is increasing in the region. The associated risks have been determined with their Relative Importance Index (RII) values of which Risk involved in Change of Design required by Owners carries the highest value (RII=0.79) whereas, Delayed Payment by Owner to Contractor is one of the least (RII=0.42) value. The overall findings suggest that most relative risks as quantified originate or associated with the contractors. It may be concluded that project proponents undertaking K-span projects in planning and budgeting the cost and delays should take into account of risks on high account if changes in design are also required any delays in the material by the supplier would then be a major risk in K-span project delay. Since projects are, less costly, so owners have limited budgets, then they hire small contractors, which are not highly competent contractors. So study suggests that owner should be aware of these types of risks associated with the construction of K-span buildings in order to make it cost effective.

Keywords: k-span buildings, k-span construction, risk management, relative improvement index (RII)

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Authors: Julia Wimmers-Klick

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In the contemporary study of anatomy, medical students utilize a diverse array of resources, including lab handouts, lectures, and, increasingly, digital media such as interactive anatomy apps and digital images. Notably, a significant shift has occurred, with fewer students possessing traditional anatomy atlases or books, reflecting a broader trend towards digital approaches like Virtual Reality, Augmented Reality, and web-based programs. This paper seeks to explore the evolution of anatomy education by contrasting current digital tools with historical resources, such as classical anatomical illustrations and atlases, to assess their relevance and potential benefits in modern medical education. Through a comprehensive literature review, the development of anatomical illustrations is traced from the textual descriptions of Galen to the detailed and artistic representations of Da Vinci, Vesalius, and later anatomists. The examination includes how the printing press facilitated the dissemination of anatomical knowledge, transforming covert dissections into public spectacles and formalized teaching practices. Historical illustrations, often influenced by societal, religious, and aesthetic contexts, not only served educational purposes but also reflected the prevailing medical knowledge and ethical standards of their times. Critical questions are raised about the place of historical illustrations in today's anatomy curriculum. Specifically, their potential to teach critical thinking, highlight the history of medicine, and offer unique insights into past societal conditions are explored. These resources are viewed in their context, including the lack of diversity and the presence of ethical concerns, such as the use of illustrations from unethical sources like Pernkopf’s atlas. In conclusion, while digital tools offer innovative ways to visualize and interact with anatomical structures, historical illustrations provide irreplaceable value in understanding the evolution of medical knowledge and practice. The study advocates for a balanced approach that integrates traditional and modern resources to enrich medical education, promote critical thinking, and provide a comprehensive understanding of anatomy. Future research should investigate the optimal combination of these resources to meet the evolving needs of medical learners and the implications of the digital shift in anatomy education.

Keywords: human anatomy, historical illustrations, historical context, medical education

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Authors: Assel Thami Lahlou, Soufiane Stouti, Ismail Lagrat, Hamid Mounir, Oussama Bouazaoui

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The purpose of this research work is to predict the helicopter from stalling by finding the minimum and maximum values that the pitch angle can take in order to fly in a hover state condition. The stall of a helicopter in hover occurs when the pitch angle is too small to generate the thrust required to support its weight or when the critical angle of attack that gives maximum lift is reached or exceeded. In order to find the minimum pitch angle, a 3D CFD simulation was done in this work using ANSYS FLUENT as the CFD solver. We started with a small value of the pitch angle θ, and we kept increasing its value until we found the thrust coefficient required to fly in a hover state and support the weight of the helicopter. For the CFD analysis, the Multiple Reference Frame (MRF) method with k-ε turbulent model was used to study the 3D flow around the rotor for θmin. On the other hand, a 2D simulation of the airfoil NACA 0012 was executed with a velocity inlet Vin=ΩR/2 to visualize the flow at the location span R/2 of the disk rotor using the Spallart-Allmaras turbulent model. Finding the critical angle of attack at this position will give us the ability to predict the stall in hover flight. The results obtained will be exposed later in the article. This study was so useful in analyzing the limitations of the helicopter’s main rotor and thus, in predicting accidents that can lead to a lot of damage.

Keywords: aerodynamic, CFD, helicopter, stall, blades, main rotor, minimum pitch angle, maximum pitch angle

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Authors: N. G. Margiani, I. G. Kvartskhava, G. A. Mumladze, Z. A. Adamia

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Chemical doping with different elements and compounds at various amounts represents the most suitable approach to improve the superconducting properties of bismuth-based superconductors for technological applications. In this paper, the influence of partial substitution of Sr(BO₂)₂ for SrO on the phase formation kinetics and transport properties of (Bi,Pb)-2223 HTS has been studied for the first time. Samples with nominal composition Bi_1.7Pb_0.3Sr_2-xCa₂Cu₃O_y[Sr(BO₂)₂]_x, x=0, 0.0375, 0.075, 0.15, 0.25, were prepared by the standard solid state processing. The appropriate mixtures were calcined at 845 ^oC for 40 h. The resulting materials were pressed into pellets and annealed at 837 ^oC for 30 h in air. Superconducting properties of undoped (reference) and Sr(BO₂)₂-doped (Bi,Pb)-2223 compounds were investigated through X-ray diffraction (XRD), resistivity (ρ) and transport critical current density (J_c) measurements. The surface morphology changes in the prepared samples were examined by scanning electron microscope (SEM). XRD and J_c studies have shown that the low level Sr(BO₂)₂ doping (x=0.0375-0.075) to the Sr-site promotes the formation of high-T_c phase and leads to the enhancement of current carrying capacity in (Bi,Pb)-2223 HTS. The doped sample with x=0.0375 has the best performance compared to other prepared samples. The estimated volume fraction of (Bi,Pb)-2223 phase increases from ~25 % for reference specimen to ~70 % for x=0.0375. Moreover, strong increase in the self-field J_c value was observed for this dopant amount (J_c=340 A/cm²), compared to an undoped sample (J_c=110 A/cm²). Pronounced enhancement of superconducting properties of (Bi,Pb)-2223 superconductor can be attributed to the acceleration of high-T_c phase formation as well as the improvement of inter-grain connectivity by small amounts of Sr(BO₂)₂ dopant.

Keywords: bismuth-based superconductor, critical current density, phase formation, Sr(BO₂)₂ doping

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Authors: Sidharth Talan, Devendra Kumar Yadav, Yuvraj Singh Rajput, Subhajit Bhattacharjee

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Mining industry is known for its appetite to spend sizeable capital on mine equipment. However, in the current scenario, the mining industry is challenged by daunting factors of non-uniform geological conditions, uneven ore grade, uncontrollable and volatile mineral commodity prices and the ever increasing quest to optimize the capital and operational costs. Thus, the role of equipment reliability and maintenance planning inherits a significant role in augmenting the equipment availability for the operation and in turn boosting the mine productivity. This paper presents the Risk Based Maintenance (RBM) planning conducted on mine loading equipment namely Load Haul Dumpers (LHDs) at Vedanta Resources Ltd subsidiary Hindustan Zinc Limited operated Sindesar Khurd Mines, an underground zinc and lead mine situated in Dariba, Rajasthan, India. The mining equipment at the location is maintained by the Original Equipment Manufacturers (OEMs) namely Sandvik and Atlas Copco, who carry out the maintenance and inspection operations for the equipment. Based on the downtime data extracted for the equipment fleet over the period of 6 months spanning from 1^st January 2017 until 30^th June 2017, it was revealed that significant contribution of three downtime issues related to namely Engine, Hydraulics, and Transmission to be common among all the loading equipment fleet and substantiated by Pareto Analysis. Further scrutiny through Bubble Matrix Analysis of the given factors revealed the major influence of selective factors namely Overheating, No Load Taken (NTL) issues, Gear Changing issues and Hose Puncture and leakage issues. Utilizing the equipment wise analysis of all the downtime factors obtained, spares consumed, and the alarm logs extracted from the machines, technical design changes in the equipment and pre shift critical alarms checklist were proposed for the equipment maintenance. The given analysis is beneficial to allow OEMs or mine management to focus on the critical issues hampering the reliability of mine equipment and design necessary maintenance strategies to mitigate them.

Keywords: bubble matrix analysis, LHDs, OEMs, Pareto chart analysis, spares consumption matrix, critical alarms checklist

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Authors: Mohammad R. Kavian Nezhad, Carlos F. Lange, Brian A. Fleck

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This research presents the validation study of a computational fluid dynamics (CFD) model developed to simulate the scalar dispersion emitted from rooftop sources around the buildings at the University of Alberta North Campus. The ANSYS CFX code was used to perform the numerical simulation of the wind regime and pollutant dispersion by solving the 3D steady Reynolds-averaged Navier-Stokes (RANS) equations on a building-scale high-resolution grid. The validation study was performed in two steps. First, the CFD model performance in 24 cases (eight wind directions and three wind speeds) was evaluated by comparing the predicted flow fields with the available data from the previous measurement campaign designed at the North Campus, using the standard deviation method (SDM), while the estimated results of the numerical model showed maximum average percent errors of approximately 53% and 37% for wind incidents from the North and Northwest, respectively. Good agreement with the measurements was observed for the other six directions, with an average error of less than 30%. In the second step, the reliability of the implemented turbulence model, numerical algorithm, modeling techniques, and the grid generation scheme was further evaluated using the Mock Urban Setting Test (MUST) dispersion dataset. Different statistical measures, including the fractional bias (FB), the geometric mean bias (MG), and the normalized mean square error (NMSE), were used to assess the accuracy of the predicted dispersion field. Our CFD results are in very good agreement with the field measurements.

Keywords: CFD, plume dispersion, complex urban geometry, validation study, wind flow

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Authors: Takeshi Takemoto, Naoya Suzuki, Naohisa Takagaki, Satoru Komori, Masako Terui, George Truscott

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Drag coefficient is an important parameter in order to correctly estimate the air-sea momentum flux. However, The parameterization of the drag coefficient hasn’t been established due to the variation in the field data. Instead, a number of drag coefficient model formulae have been proposed, even though almost all these models haven’t discussed the extreme wind speed range. With regards to such models, it is unclear how the drag coefficient changes in the extreme wind speed range as the wind speed increased. In this study, we investigated the effect of the drag coefficient models concerning the air-sea momentum flux in the extreme wind range on a global scale, comparing two different drag coefficient models. Interestingly, one model didn’t discuss the extreme wind speed range while the other model considered it. We found that the difference of the models in the annual global air-sea momentum flux was small because the occurrence frequency of strong wind was approximately 1% with a wind speed of 20m/s or more. However, we also discovered that the difference of the models was shown in the middle latitude where the annual mean air-sea momentum flux was large and the occurrence frequency of strong wind was high. In addition, the estimated data showed that the difference of the models in the drag coefficient was large in the extreme wind speed range and that the largest difference became 23% with a wind speed of 35m/s or more. These results clearly show that the difference of the two models concerning the drag coefficient has a significant impact on the estimation of a regional air-sea momentum flux in an extreme wind speed range such as that seen in a tropical cyclone environment. Furthermore, we estimated each air-sea momentum flux using several kinds of drag coefficient models. We will also provide data from an observation tower and result from CFD (Computational Fluid Dynamics) concerning the influence of wind flow at and around the place.

Keywords: air-sea interaction, drag coefficient, air-sea momentum flux, CFD (Computational Fluid Dynamics)

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Authors: Sisaye Tamrat Ayalew

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This paper focuses on the educational philosophy of universities in Ethiopia and the debates surrounding it. It highlights the contradictory views on the role of universities, with some perceiving them as practical problem-solving institutions and others emphasizing the production and dissemination of knowledge. The aim of this study is to critically explore the debates around the educational philosophy of universities in Ethiopia. It also seeks to examine how the understanding of this philosophy contributes to the marginalization of youth in the country. This research adopts a phenomenological qualitative research design. It aims to understand the impact of socio-economic and political factors on university education and how youth from disadvantaged backgrounds experience marginalization in the job market. The study reveals that the understanding of educational philosophy varies across different contexts and over time. In the Ethiopian context, the philosophy of universities lacks a disinterested pursuit of knowledge and instrumentalist epistemology. Instead, it oversimplifies the philosophy to the point of devaluing knowledge and treating certificates as commodities, even in the absence of formal training. In conclusion, this research highlights the need for a critical appraisal of the educational philosophy of universities in Ethiopia. It emphasizes the negative impact of an oversimplified and commodified approach to knowledge on the empowerment of youth. By bringing attention to these issues, this study contributes to the broader understanding of the role of universities in society and calls for reforms in the Ethiopian education sector to promote empowerment rather than disempowerment.

Keywords: philosophy of universities, marginalized youth, diploma mill, instrumentalist epistemology, disinterested pursuit

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Authors: Stanley Yap, Chong Wei Ying, Leow Hon Wei

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Purpose: In Malaysia, an effective financial planning is vital to accumulate wealth and financial independence. However, retirees are required to resume working due to insufficient pension fund. This study examines how the financial decision in retirement planning is being made based on the net worth from the household. Design/methodology/approach: This study uses financial data from a married working couple with children to evaluate their composition of financial position. Numerous financial methods are made pertaining to net worth analysis, insurance needs analysis, investment portfolio rebalancing, estate planning, education planning and retirement planning to enhance the financial decision. Findings: Our results show, firstly, financial planning is essential to achieve financial independence; secondly, insurance needs, education and retirement funding are the most significant for household. Thirdly, current resources are critical to maintain family lifestyle after retirement, emergency funds for critical illness, and the long term children education funding. Practical implications: Refer to the findings, sufficient net worth is priority in financial planning. Different suggestions for household include reduction of unnecessary expenses, re-allocate of cash flow, adequate insurance coverage and re-balancing of investment portfolios to accumulate wealth. It is a challenge to obtain financial independence, hence, there is a need to increase the literature on financial planning. Originality/value: To the best of our knowledge, this is the important paper that uses financial information from household to provide solutions to enhance the efficiency of financial planning industry.

Keywords: net worth, financial planning, wealth and financial independence, retirement planning

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Authors: Paraskevi Liosatou

Abstract:

Climate change is considered to be of global concern being amplified by the fact that by its nature, cannot be spatially limited. This fact makes necessary the intergovernmental decision-making procedures. In the intergovernmental level, the institutions such as the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change develop efforts, methods, and practices in order to plan and suggest climate mitigation and adaptation measures. These measures are based on specific scientific findings and methods making clear the strong connection between science and policy. In particular, these scientific recommendations offer a series of practices, methods, and choices mitigating the problem by aiming at the indirect mitigation of the causes and the factors amplifying climate change. Moreover, modern production and economic context do not take into consideration the social, political, environmental and spatial dimensions of the problem. This work studies the decision-making process working in international and European level. In this context, this work considers the policy tools that have been implemented by various intergovernmental organizations. The methodology followed is based mainly on the critical study of standards and process concerning the connections and cooperation between science and policy as well as considering the skeptic debates developed. The finding of this work focuses on the links between science and policy developed by the institutional and scientific mechanisms concerning climate change mitigation. It also analyses the dimensions and the factors of the science-policy framework; in this way, it points out the causes that maintain skepticism in current scientific circles.

Keywords: climate change, climate change mitigation, climate change skepticism, IPCC, skepticism

Procedia PDF Downloads 134