Search results for: impact force
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 13094

Search results for: impact force

12614 Environmental Impact Assessment of Conventional Tyre Manufacturing Process

Authors: G. S. Dangayach, Gaurav Gaurav, Alok Bihari Singh

Abstract:

The popularity of vehicles in both industrialized and developing economies led to a rise in the production of tyres. People have become increasingly concerned about the tyre industry's possible environmental impact in the last two decades. The life cycle assessment (LCA) methodology was used to assess the environmental impacts of industrial tyres throughout their life cycle, which included four stages: manufacture, transportation, consumption, and end-of-life. The majority of prior studies focused on tyre recycling and disposal. Only a few studies have been conducted on the environmental impact of tyre production process. LCA methodology was employed to determine the environmental impact of tyre manufacture process (gate to gate) at an Indian firm. Comparative analysis was also conducted to identify the environmental hotspots in various stages of tire manufacturing. This study is limited to gate-to-gate analysis of manufacturing processes with the functional unit of a single tyre weighing 50 kg. GaBi software was used to do both qualitative and quantitative analysis. Different environmental impact indicators are measured in terms of CO2, SO2, NOx, GWP (global warming potential), AP (acidification potential), EP (eutrophication potential), POCP (photochemical oxidant formation potential), and HTP (toxic human potential). The results demonstrate that the major contributor to environmental pollution is electricity. The Banbury process has a very high negative environmental impact, which causes respiratory problems to workers and operators.

Keywords: life cycle assessment (LCA), environmental impact indicators, tyre manufacturing process, environmental impact assessment

Procedia PDF Downloads 153
12613 Best Practices and Recommendations for CFD Simulation of Hydraulic Spool Valves

Authors: Jérémy Philippe, Lucien Baldas, Batoul Attar, Jean-Charles Mare

Abstract:

The proposed communication deals with the research and development of a rotary direct-drive servo valve for aerospace applications. A key challenge of the project is to downsize the electromagnetic torque motor by reducing the torque required to drive the rotary spool. It is intended to optimize the spool and the sleeve geometries by combining a Computational Fluid Dynamics (CFD) approach with commercial optimization software. The present communication addresses an important phase of the project, which consists firstly of gaining confidence in the simulation results. It is well known that the force needed to pilot a sliding spool valve comes from several physical effects: hydraulic forces, friction and inertia/mass of the moving assembly. Among them, the flow force is usually a major contributor to the steady-state (or Root Mean Square) driving torque. In recent decades, CFD has gradually become a standard simulation tool for studying fluid-structure interactions. However, in the particular case of high-pressure valve design, the authors have experienced that the calculated overall hydraulic force depends on the parameterization and options used to build and run the CFD model. To solve this issue, the authors have selected the standard case of the linear spool valve, which is addressed in detail in numerous scientific references (analytical models, experiments, CFD simulations). The first CFD simulations run by the authors have shown that the evolution of the equivalent discharge coefficient vs. Reynolds number at the metering orifice corresponds well to the values that can be predicted by the classical analytical models. Oppositely, the simulated flow force was found to be quite different from the value calculated analytically. This drove the authors to investigate minutely the influence of the studied domain and the setting of the CFD simulation. It was firstly shown that the flow recirculates in the inlet and outlet channels if their length is not sufficient regarding their hydraulic diameter. The dead volume on the uncontrolled orifice side also plays a significant role. These examples highlight the influence of the geometry of the fluid domain considered. The second action was to investigate the influence of the type of mesh, the turbulence models and near-wall approaches, and the numerical solver and discretization scheme order. Two approaches were used to determine the overall hydraulic force acting on the moving spool. First, the force was deduced from the momentum balance on a control domain delimited by the valve inlet and outlet and the spool walls. Second, the overall hydraulic force was calculated from the integral of pressure and shear forces acting at the boundaries of the fluid domain. This underlined the significant contribution of the viscous forces acting on the spool between the inlet and outlet orifices, which are generally not considered in the literature. This also emphasized the influence of the choices made for the implementation of CFD calculation and results analysis. With the step-by-step process adopted to increase confidence in the CFD simulations, the authors propose a set of best practices and recommendations for the efficient use of CFD to design high-pressure spool valves.

Keywords: computational fluid dynamics, hydraulic forces, servovalve, rotary servovalve

Procedia PDF Downloads 45
12612 Analyzing the Technology Affecting on the Social Integration of Students at University

Authors: Sujit K. Basak, Simon Collin

Abstract:

The aim of this paper is to examine the technology access and use on the affecting social integration of local students at university. This aim is achieved by designing a structural equation modeling (SEM) in terms of integration with peers, integration with faculty, faculty support and on the other hand, examining the socio demographic impact on the technology access and use. The collected data were analyzed using the WarpPLS 5.0 software. This study was survey based and it was conducted at a public university in Canada. The results of the study indicated that technology has a strong impact on integration with faculty, faculty support, but technology does not have an impact on integration with peers. However, the social demographic has also an impact on the technology access and use.

Keywords: faculty, integration, peer, technology access and use

Procedia PDF Downloads 514
12611 Dynamic Analysis and Clutch Adaptive Prefill in Dual Clutch Transmission

Authors: Bin Zhou, Tongli Lu, Jianwu Zhang, Hongtao Hao

Abstract:

Dual clutch transmissions (DCT) offer a high comfort performance in terms of the gearshift. Hydraulic multi-disk clutches are the key components of DCT, its engagement determines the shifting comfort. The prefill of the clutches requests an initial engagement which the clutches just contact against each other but not transmit substantial torque from the engine, this initial clutch engagement point is called the touch point. Open-loop control is typically implemented for the clutch prefill, a lot of uncertainties, such as oil temperature and clutch wear, significantly affects the prefill, probably resulting in an inappropriate touch point. Underfill causes the engine flaring in gearshift while overfill arises clutch tying up, both deteriorating the shifting comfort of DCT. Therefore, it is important to enable an adaptive capacity for the clutch prefills regarding the uncertainties. In this paper, a dynamic model of the hydraulic actuator system is presented, including the variable force solenoid and clutch piston, and validated by a test. Subsequently, the open-loop clutch prefill is simulated based on the proposed model. Two control parameters of the prefill, fast fill time and stable fill pressure is analyzed with regard to the impact on the prefill. The former has great effects on the pressure transients, the latter directly influences the touch point. Finally, an adaptive method is proposed for the clutch prefill during gear shifting, in which clutch fill control parameters are adjusted adaptively and continually. The adaptive strategy is changing the stable fill pressure according to the current clutch slip during a gearshift, improving the next prefill process. The stable fill pressure is increased by means of the clutch slip while underfill and decreased with a constant value for overfill. The entire strategy is designed in the Simulink/Stateflow, and implemented in the transmission control unit with optimization. Road vehicle test results have shown the strategy realized its adaptive capability and proven it improves the shifting comfort.

Keywords: clutch prefill, clutch slip, dual clutch transmission, touch point, variable force solenoid

Procedia PDF Downloads 308
12610 Effects of Matrix Properties on Surfactant Enhanced Oil Recovery in Fractured Reservoirs

Authors: Xiaoqian Cheng, Jon Kleppe, Ole Torsæter

Abstract:

The properties of rocks have effects on efficiency of surfactant. One objective of this study is to analyze the effects of rock properties (permeability, porosity, initial water saturation) on surfactant spontaneous imbibition at laboratory scale. The other objective is to evaluate existing upscaling methods and establish a modified upscaling method. A core is put in a container that is full of surfactant solution. Assume there is no space between the bottom of the core and the container. The core is modelled as a cuboid matrix with a length of 3.5 cm, a width of 3.5 cm, and a height of 5 cm. The initial matrix, brine and oil properties are set as the properties of Ekofisk Field. The simulation results of matrix permeability show that the oil recovery rate has a strong positive linear relationship with matrix permeability. Higher oil recovery is obtained from the matrix with higher permeability. One existing upscaling method is verified by this model. The study on matrix porosity shows that the relationship between oil recovery rate and matrix porosity is a negative power function. However, the relationship between ultimate oil recovery and matrix porosity is a positive power function. The initial water saturation of matrix has negative linear relationships with ultimate oil recovery and enhanced oil recovery. However, the relationship between oil recovery and initial water saturation is more complicated with the imbibition time because of the transition of dominating force from capillary force to gravity force. Modified upscaling methods are established. The work here could be used as a reference for the surfactant application in fractured reservoirs. And the description of the relationships between properties of matrix and the oil recovery rate and ultimate oil recovery helps to improve upscaling methods.

Keywords: initial water saturation, permeability, porosity, surfactant EOR

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12609 A Comparative Study on the Impact of Global Warming of Applying Low Carbon Factor Concrete Products

Authors: Su-Hyun Cho, Chang-U Chae

Abstract:

Environmental impact assessment techniques have been developed as a result of the worldwide efforts to reduce the environmental impact of global warming. By using the quantification method in the construction industry, it is now possible to manage the greenhouse gas is to systematically evaluate the impact on the environment over the entire construction process. In particular, the proportion of greenhouse gas emissions at the production stage of construction material occupied is high, and efforts are needed in particular in the construction field. In this study, intended for concrete products for the construction materials, by using the LCA evaluation method, we compared the results of environmental impact assessment and carbon emissions of developing products that have been applied low-carbon technologies compared to existing products. As a results, by introducing a raw material of industrial waste, showed carbon reduction. Through a comparison of the carbon emission reduction effect of low-carbon technologies, it is intended to provide academic data for the evaluation of greenhouse gases in the construction sector and the development of low-carbon technologies of the future.

Keywords: CO₂ emissions, CO₂ reduction, ready-mixed concrete, environmental impact assessment

Procedia PDF Downloads 479
12608 Investigating the Sloshing Characteristics of a Liquid by Using an Image Processing Method

Authors: Ufuk Tosun, Reza Aghazadeh, Mehmet Bülent Özer

Abstract:

This study puts forward a method to analyze the sloshing characteristics of liquid in a tuned sloshing absorber system by using image processing tools. Tuned sloshing vibration absorbers have recently attracted researchers’ attention as a seismic load damper in constructions due to its practical and logistical convenience. The absorber is liquid which sloshes and applies a force in opposite phase to the motion of structure. Experimentally characterization of the sloshing behavior can be utilized as means of verifying the results of numerical analysis. It can also be used to identify the accuracy of assumptions related to the motion of the liquid. There are extensive theoretical and experimental studies in the literature related to the dynamical and structural behavior of tuned sloshing dampers. In most of these works there are efforts to estimate the sloshing behavior of the liquid such as free surface motion and total force applied by liquid to the wall of container. For these purposes the use of sensors such as load cells and ultrasonic sensors are prevalent in experimental works. Load cells are only capable of measuring the force and requires conducting tests both with and without liquid to obtain pure sloshing force. Ultrasonic level sensors give point-wise measurements and hence they are not applicable to measure the whole free surface motion. Furthermore, in the case of liquid splashing it may give incorrect data. In this work a method for evaluating the sloshing wave height by using camera records and image processing techniques is presented. In this method the motion of the liquid and its container, made of a transparent material, is recorded by a high speed camera which is aligned to the free surface of the liquid. The video captured by the camera is processed frame by frame by using MATLAB Image Processing toolbox. The process starts with cropping the desired region. By recognizing the regions containing liquid and eliminating noise and liquid splashing, the final picture depicting the free surface of liquid is achieved. This picture then is used to obtain the height of the liquid through the length of container. This process is verified by ultrasonic sensors that measured fluid height on the surface of liquid.

Keywords: fluid structure interaction, image processing, sloshing, tuned liquid damper

Procedia PDF Downloads 345
12607 Viability of Slab Sliding System for Single Story Structure

Authors: C. Iihoshi, G. A. MacRae, G. W. Rodgers, J. G. Chase

Abstract:

Slab Sliding System (SSS) with Coulomb friction interface between slab and supporting frame is a passive structural vibration control technology. The system can significantly reduce the slab acceleration and accompanied lateral force of the frame. At the same time it is expected to cause the slab displacement magnification by sliding movement. To obtain the general comprehensive seismic response of a single story structure, inelastic response spectra were computed for a large ensemble of ground motions and a practical range of structural periods and friction coefficient values. It was shown that long period structures have no trade-off relation between force reduction and displacement magnification with respect to elastic response, unlike short period structures. For structures with the majority of mass in the slab, the displacement magnification value can be predicted according to simple inelastic displacement relation for in elastically responding SDOF structures because the system behaves elastically to a SDOF structure.

Keywords: earthquake, isolation, slab, sliding

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12606 Caped Intervention: A Single Country Comparative Study of the Role of Russia in Its Involvement in the Crimean Crisis 2014

Authors: Katrina Angeline Santos, Francis Mark Fernandez, Francheska Esmao

Abstract:

Intervention is defined as a forcible interference by a state or states with power in the affairs of another state using force or the threat of force. On the other hand, a military intervention is an intervention, specifically used to define an intervention which uses force. With these, the authors realized a lack in the concept of intervention wherein it is an invited one.The authors wrote this paper to introduce a concept of intervention wherein the intervening state is offering assistance to the state in crisis which asked for one. The authors decided to make a contextual description of this phenomenon because of the lack of concepts regarding intervention between the idea of a single state performing a ‘heroic’ role of intervening in the crisis of another state. The problem that the authors would like to address is regarding the lack of availability in the concept of intervention wherein the state in crisis is seeking the assistance of another state. The authors utilized a contextual description approach to the study through the descriptive presentation of the series of events, by utilizing the news articles and news reports published, which happened in Ukraine and Crimea. This concept is further demonstrated through the utilization of a conceptual framework which shows the mutual relationship between the states. From the analysis of the behavior of Russia and its role in the Crimean Crisis 2014, the authors are able to coin the term, 'Caped Intervention' to describe an intervention of a state as a response to the invitation of assistance of a state in crisis in order for them to achieve their goals. This concept entails a mutual relationship between an intervening state and a sate in crisis. The concept of Caped Intervention describes the role of Russia as a Caped State or an intervening state observed through its action towards Crimea. This concept will help in the observation of the behavior of actors or states in events such as this. It will further help in analyzing the actors’ role in intervention by making it possible to classify the intervening acts into another concept.

Keywords: assistance, caped intervention, crisis, heroic

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12605 Mathematical Properties of the Resonance of the Inner Waves in Rotating Stratified Three-Dimensional Fluids

Authors: A. Giniatoulline

Abstract:

We consider the internal oscillations of the ocean which are caused by the gravity force and the Coriolis force, for different models with changeable density, heat transfer, and salinity. Traditionally, the mathematical description of the resonance effect is related to the growing amplitude as a result of input vibrations. We offer a different approach: the study of the relation between the spectrum of the internal oscillations and the properties of the limiting amplitude of the solution for the harmonic input vibrations of the external forces. Using the results of the spectral theory of self-adjoint operators in Hilbert functional spaces, we prove that there exists an explicit relation between the localization of the frequency of the external input vibrations with respect to the essential spectrum of proper inner oscillations and the non-uniqueness of the limiting amplitude. The results may find their application in various problems concerning mathematical modeling of turbulent flows in the ocean.

Keywords: computational fluid dynamics, essential spectrum, limiting amplitude, rotating fluid, spectral theory, stratified fluid, the uniqueness of solutions of PDE equations

Procedia PDF Downloads 258
12604 Checking Planetary Clutch on the Romania Tractor Using Mathematical Equations

Authors: Mohammad Vahedi Torshizi

Abstract:

In this investigation, at first, bending stress, contact stress, Safety factor of bending and Safety factor of contact between sun gear and planet gear tooth was determined using mathematical equations. Also, The amount of Sun Revolution in, Speed carrier, power Transmitted of the sun, sun torque, sun peripheral speed, Enter the tangential force gears, was calculated using mathematical equations. According to the obtained results, maximum of bending stress and contact stress occurred in three plantary and low status of four plantary. Also, maximum of Speed carrier, sun peripheral speed, Safety factor of bending and Safety factor of contact obtained in four plantary and maximum of power Transmitted of the sun, Enter the tangential force gears, bending stress and contact stress was in three pantry and factors And other factors were equal in the two planets.

Keywords: bending stress, contact stress, plantary, mathematical equations

Procedia PDF Downloads 289
12603 The Acute Effects of Higher Versus Lower Load Duration and Intensity on Morphological and Mechanical Properties of the Healthy Achilles Tendon: A Randomized Crossover Trial

Authors: Eman Merza, Stephen Pearson, Glen Lichtwark, Peter Malliaras

Abstract:

The Achilles tendon (AT) exhibits volume changes related to fluid flow under acute load which may be linked to changes in stiffness. Fluid flow provides a mechanical signal for cellular activity and may be one mechanism that facilitates tendon adaptation. This study aimed to investigate whether isometric intervention involving a high level of load duration and intensity could maximize the immediate reduction in AT volume and stiffness compared to interventions involving a lower level of load duration and intensity. Sixteen healthy participants (12 males, 4 females; age= 24.4 ± 9.4 years; body mass= 70.9 ± 16.1 kg; height= 1.7 ± 0.1 m) performed three isometric interventions of varying levels of load duration (2 s and 8 s) and intensity (35% and 75% maximal voluntary isometric contraction) over a 3 week period. Freehand 3D ultrasound was used to measure free AT volume (at rest) and length (at 35%, 55%, and 75% of maximum plantarflexion force) pre- and post-interventions. The slope of the force-elongation curve over these force levels represented individual stiffness (N/mm). Large reductions in free AT volume and stiffness resulted in response to long-duration high-intensity loading whilst less reduction was produced with a lower load intensity. In contrast, no change in free AT volume and a small increase in AT stiffness occurred with lower load duration. These findings suggest that the applied load on the AT must be heavy and sustained for a long duration to maximize immediate volume reduction, which might be an acute response that enables optimal long-term tendon adaptation via mechanotransduction pathways.

Keywords: Achilles tendon, volume, stiffness, free tendon, 3d ultrasound

Procedia PDF Downloads 102
12602 National Projects' Impact on the Regional Division

Authors: Mosaad Hamouda, Kamal Khalaf, Zaker Mousa

Abstract:

National projects are considered Egypt's future vision in investing its various resources and the best way to bring about a developmental renaissance that constitutes a quantum leap because of its developmental impact on the planning regions, which it achieves in attracting and localizing investments to achieve urban development, and what this has a noticeable impact on dividing those regions in order to achieve a developmental balance or at least reduce the severity of the disparities between them, by measuring the impact of these projects, which appear in the per capita share of the various developmental variables, and also analyzing global and local experiences so that a balanced division of the country’s regions can be reached, and the research finds a set of planning foundations that are compatible with the settlement of these national projects in the future.

Keywords: national projects, regional development, division of regions, development disparities

Procedia PDF Downloads 126
12601 Development of 35kV SF6 Phase-Control Circuit Breaker Equipped with EFDA

Authors: Duanlei Yuan, Guangchao Yan, Zhanqing Chen, Xian Cheng

Abstract:

This paper mainly focuses on the problem that high voltage circuit breaker’s closing and opening operation at random phase brings harmful electromagnetic transient effects on the power system. To repress the negative transient effects, a 35 kV SF6 phase-control circuit breaker equipped with electromagnetic force driving actuator is designed in this paper. Based on the constructed mathematical and structural models, the static magnetic field distribution and dynamic properties of the under loading actuator are simulated. The prototype of 35 kV SF6 phase-control circuit breaker is developed based on theories analysis and simulation. Tests are carried on to verify the operating reliability of the prototype. The developed circuit breaker can control its operating speed intelligently and switches with phase selection. Results of the tests and simulation prove that the phase-control circuit breaker is feasible for industrial applications.

Keywords: phase-control, circuit breaker, electromagnetic force driving actuator, tests and simulation

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12600 COVID-19 Impact: How the Pandemic Changed the Fashion Industry

Authors: Akshata Patel, Reenu Singh

Abstract:

This paper focuses on current and upcoming fashion trends and global impact on the fashion industry due to the COVID-19 pandemic. The pandemic has had a major impact on the fashion industry worldwide. At the same time, the fashion market also faces challenges in consumer demand. As the supply chain and distribution channels are interconnected, this outbreak has a global impact due to travel restrictions and raw materials shortages. Given that this particular period represents an unprecedented market situation with almost no prior research on how the industry will recover from such a crisis and mold back to its original form, this research aims to propose new possibilities by evaluating the framework of specific segments. Based on the analysis and extensive literature review, the study develops a conceptual model that will illustrate the various connections among the different segments of the fashion industry. The findings provide actionable considerations for fashion industry pupils when implementing appropriate strategies to prevent unfavourable outcomes during times of crisis, such as the COVID-19 outbreak.

Keywords: COVID-19, fashion industry, global impact, new possibilities, pandemic

Procedia PDF Downloads 286
12599 Capturing the Stress States in Video Conferences by Photoplethysmographic Pulse Detection

Authors: Jarek Krajewski, David Daxberger

Abstract:

We propose a stress detection method based on an RGB camera using heart rate detection, also known as Photoplethysmography Imaging (PPGI). This technique focuses on the measurement of the small changes in skin colour caused by blood perfusion. A stationary lab setting with simulated video conferences is chosen using constant light conditions and a sampling rate of 30 fps. The ground truth measurement of heart rate is conducted with a common PPG system. The proposed approach for pulse peak detection is based on a machine learning-based approach, applying brute force feature extraction for the prediction of heart rate pulses. The statistical analysis showed good agreement (correlation r = .79, p<0.05) between the reference heart rate system and the proposed method. Based on these findings, the proposed method could provide a reliable, low-cost, and contactless way of measuring HR parameters in daily-life environments.

Keywords: heart rate, PPGI, machine learning, brute force feature extraction

Procedia PDF Downloads 125
12598 Examining the Impact of Fake News on Mental Health of Residents in Jos Metropolis

Authors: Job Bapyibi Guyson, Bangripa Kefas

Abstract:

The advent of social media has no doubt provided platforms that facilitate the spread of fake news. The devastating impact of this does not only end with the prevalence of rumours and propaganda but also poses potential impact on individuals’ mental well-being. Therefore, this study on examining the impact of fake news on the mental health of residents in Jos metropolis among others interrogates the impact of exposure to fake news on residents' mental health. Anchored on the Cultivation Theory, the study adopted quantitative method and surveyed two the opinions of hundred (200) social media users in Jos metropolis using purposive sampling technique. The findings reveal that a significant majority of respondents perceive fake news as highly prevalent on social media, with associated feelings of anxiety and stress. The majority of the respondents express confidence in identifying fake news, though a notable proportion lacks such confidence. Strategies for managing the mental impact of encountering fake news include ignoring it, fact checking, discussing with others, reporting to platforms, and seeking professional support. Based on these insights, recommendations were proposed to address the challenges posed by fake news. These include promoting media literacy, integrating fact-checking tools, adjusting algorithms and fostering digital well-being features among others.

Keywords: fake news, mental health, social media, impact

Procedia PDF Downloads 57
12597 The Role of Human Capital in Rural Development: A Critical Look at Ethiopian Education Policy

Authors: Blen Telayneh Melese

Abstract:

Rural development, the unending quest of a developing country, cannot be succeeded in deprived of human capital development. Human capital, the economic pillars of a country's development, appeals a policy-based supports while fulfilling what is expected. Ethiopia, one of the rural countries with untouched and forgotten land and human force, owes historical experiences of educational policy intending for mobilization of its citizen for the advancement of the overall economy. Rural Ethiopia as well has been the focus of those educational policies, considering the economic resources entrenched with in. In this literature review paper, Ethiopian educational policy and its contribution to human capital development, as well as its role in generating quality human labor force, is assessed concisely. The author argues that the foundation of rural development such as technology, knowledge, infrastructure, market chain, communication and etc., can only be achieved through enhanced education policy that conciliates the existing reality of rural communities. Ethiopia still needs an education policy that enables it to generate a human capital that is oriented with the rural areas economic opportunities and challenges.

Keywords: Ethiopia, rural development, human capital development, education policy

Procedia PDF Downloads 361
12596 Implications about the Impact of COVID-19 on Business

Authors: Anwar Kashgari

Abstract:

COVID-19 has severe impacts on business all over the world. The great lockdown of many business owners requires a sage deal with this pandemic. This paper seeks to support business leaders with a standpoint about the COVID-19 situation and provides implications for the (Small and Medium Enterprises) SMEs and companies. The paper reflects the author's view about the impact of COVID-19 on business activities. We discussed the impact of COVID-19 upon three aspects, namely, startups, SMEs, and e-commerce. The KSA is an example of the developing countries about which we present the current situation. Finally, recommendations to policy and decision-makers are given.

Keywords: COVID 19, business networking, globalization

Procedia PDF Downloads 216
12595 Artificial Intelligence in Duolingo

Authors: Elana Mahboub, Lamar Bakhurji, Hind Alhindi, Sara Alesayi

Abstract:

Duolingo is a revolutionary language learning platform that offers an interactive and accessible learning experience. Its gamified approach makes language learning engaging and enjoyable, with a diverse range of languages available. The platform's adaptive learning system tailors lessons to individual proficiency levels, ensuring a personalized and efficient learning journey. The incorporation of multimedia elements enhances the learning experience and promotes practical language application. Duolingo's success is attributed to its mobile accessibility, offering basic access to language courses for free, with optional premium features for those seeking additional resources. Research shows positive outcomes for users, and the app's global impact extends beyond individual learning to formal language education initiatives. Duolingo is a transformative force in language education, breaking down barriers and making language learning an attainable goal for millions worldwide.

Keywords: duolingo, artificial intelligence, artificial intelligence in duolingo, benefit of artificial intelligence

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12594 Modelling the Effect of Head and Bucket Splitter Angle on the Power Output of a Pelton Turbine

Authors: J. A. Ujam, J. L. Chukwuneke, C. H. Achebe, G. O. R. Ikwu

Abstract:

This work investigates the effect of head and bucket splitter angle on the power output of a pelton turbine (water turbine), so as to boost the efficiency of Hydro-electric power generation systems. A simulation program was developed using MatLab to depict the force generated by the bucket as the water jet strikes the existing splitter angle (100 to 150) and predicted (10 to 250) splitter angles. Result shows that in addition to the existing splitter angle, six more angles have been investigated for the two operating conditions to give maximum power. The angles are 250, 60 and 190 for high head and low flow with increased pressure while low head and high flow with decreased pressure are 230, 210 and 30 in order of the maximum generating power. The Turbine power output for simulation was more than that of the experiment. This was as a result of their head conditions and the bucket splitter angle.

Keywords: bucket splitter angle, force, head, modelling, pelton turbine, power output, shaft output

Procedia PDF Downloads 356
12593 Driving Forces of Bank Liquidity: Evidence from Selected Ethiopian Private Commercial Banks

Authors: Tadele Tesfay Teame, Tsegaye Abrehame, Hágen István Zsombor

Abstract:

Liquidity is one of the main concerns for banks, and thus achieving the optimum level of liquidity is critical. The main objective of this study is to discover the driving force of selected private commercial banks’ liquidity. In order to achieve the objective explanatory research design and quantitative research approach were used. Data has been collected from a secondary source of the sampled Ethiopian private commercial banks’ financial statements, the National Bank of Ethiopia, and the Minister of Finance, the sample covering the period from 2011 to 2022. Bank-specific and macroeconomic variables were analyzed by using the balanced panel fixed effect regression model. Bank’s liquidity ratio is measured by the total liquid asset to total deposits. The findings of the study revealed that bank size, capital adequacy, loan growth rate, and non-performing loan had a statistically significant impact on private commercial banks’ liquidity, and annual inflation rate and interest rate margin had a statistically significant impact on the liquidity of Ethiopian private commercial banks measured by L1 (bank liquidity). Thus, banks in Ethiopia should not only be concerned about internal structures and policies/procedures, but they must consider both the internal environment and the macroeconomic environment together in developing their strategies to efficiently manage their liquidity position and private commercial banks to maintain their financial proficiency shall have bank liquidity management policy by assimilating both bank-specific and macro-economic variables.

Keywords: liquidity, Ethiopian private commercial banks, liquidity ratio, panel data regression analysis

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12592 Effect of Different Contact Rollers on the Surface Texture during the Belt Grinding Process

Authors: Amine Hamdi, Sidi Mohammed Merghache, Brahim Fernini

Abstract:

During abrasive machining of hard steels by belt grinding, the finished surface texture is influenced by the pressure between the abrasive belt and the workpiece; this pressure is the force applied by the contact roller on the workpiece. Therefore, the contact roller has an important role and has a direct impact on process efficiency. The objective of this article is to study and compare the influence of different contact rollers on the belt ground surface texture. The quality of the surface texture is characterized by eight roughness parameters (Ra, Rz, Rp, Rv, Rsk, Rku, Rsm, and Rdq) and five parameters of the bearing area curve (Rpk, Rk, Rvk, Mr1, and Mr2). The results of the experimental tests indicate a better surface texture obtained by the PA 6 polyamide roller (hardness 60 Shore D) compared to that obtained with other rollers of the same hardness or of different hardness. Simultaneously, optimum medium pressure between the belt and the workpiece allows chip removal without fracturing the abrasive grains. This generates a good surface texture.

Keywords: belt grinding, contact roller, pressure, abrasive belt, surface texture

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12591 Thermal Annealing Effects on Nonradiative Recombination Parameters of GaInAsSb/GaSb by Means of Photothermal Defection Technique

Authors: Souha Bouagila, Soufiene Ilahi, Noureddine Yacoubi

Abstract:

We have used Photothermal deflection spectroscopy PTD to investigate the impact of thermal annealing on electronics properties of GaInAsSb/GaSb.GaInAsSb used as an active layer for Vertical Cavity Surface Emitting laser (VCSEL). We have remarked that surface recombination velocity (SRV) from 7963 m / s (± 6.3%) to 1450 m / s (± 3.6) for as grown to sample annealed for 60 min. Accordingly, Force Microscopy images analyses agree well with the measure of surface recombination velocity. We have found that Root-Mean-Square Roughness (RMS) decreases as respect of annealing time. In addition, we have that the diffusion length and minority carrier mobility have been enhanced according to annealing time. However, due to annealing effects, the interface recombination velocity (IRV) is increased from 1196 m / s (± 5) to 6000 m/s (5%) for GaInAsSb in respect of annealed times.

Keywords: nonradiative lifetime, mobility of minority carrier, diffusion length, Surface and interface recombination velocity

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12590 The Impact of Socio-Economic and Type of Religion on the Behavior of Obedience among Arab-Israeli Teenagers

Authors: Sadhana Ghnayem

Abstract:

This article examines the relationship between several socio-economic and background variables of Arab-Israeli families and their effect on the conflict management style of forcing, where teenage children are expected to obey their parents without questioning. The article explores the inter-generational gap and the desire of Arab-Israeli parents to force their teenage children to obey without questioning. The independent variables include: the sex of the parent, religion (Christian or Muslim), income of the parent, years of education of the parent, and the sex of the teenage child. We use the dependent variable of “Obedience Without Questioning” that is reported twice: by each of the parents as well as by the children. We circulated a questionnaire and collected data from a sample of 180 parents and their adolescent child living in the Galilee area during 2018. In this questionnaire we asked each of the parent and his/her teenage child about whether the latter is expected to follow the instructions of the former without questioning. The outcome of this article indicates, first, that Christian-Arab families are less authoritarian than Muslims families in demanding sheer obedience from their children. Second, female parents indicate more than male parents that their teenage child indeed obeys without questioning. Third, there is a negative correlation between the variable “Income” and “Obedience without Questioning.” Yet, the regression coefficient of this variable is close zero. Fourth, there is a positive correlation between years of education and obedience reported by the children. In other words, more educated parents are more likely to demand obedience from their children.  Finally, after running the regression, the study also found that the impact of the variables of religion as well as the sex of the child on the dependent variable of obedience is also significant at above 95 and 90%, respectively.

Keywords: conflict, religion, conflict management style, obedience

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12589 A Research to Determine the Impact of Mobbing on Organizational Commitment

Authors: A. Bedük, k. Eryeşil, o. Eşmen, m. Onacak

Abstract:

The mobbing is a process that is consisting of negative behaviors such as, systematically and continuously insulting, offending against personal dignity, preventing access to necessary information and disseminating rumors against employee by one or more than one individuals in a work environment through which disturbing the employee physically, psychologically and socially to cause to quit his/her job. This research is aiming to explore the results of mobbing (psychological violence) on employees’ organizational commitment in workplaces. Mobbing takes many forms and is often used to force an employee to leave the work environment. Two different types of scales have been reviewed and revised for use in the research. The Heinz Leymann scale is the first measure, which was developed to define causes and effects, in addition to characteristic behaviors of mobbing. The second scale was developed by Allen and Mayer and indicates levels of organizational commitment. In this research, a questionnaire were applied to 50 employees in a special glass factory in Konya to search mobbing itself and indicate the effects of mobbing to organizational commitments. One of the important findings of this research is that there was no relation between mobbing and general organizational commitment.

Keywords: mobbing, organizational commitment, affective commitment, normative commitment, continuance commitment

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12588 Triplet Shear Tests on Retrofitted Brickwork Masonry Walls

Authors: Berna Istegun, Erkan Celebi

Abstract:

The main objective of this experimental study is to assess the shear strength and the crack behavior of the triplets built of perforated brickwork masonry elements. In order to observe the influence of shear resistance and energy dissipating before and after retrofitting applications by using the reinforcing system, static-cyclic shear tests were employed in the structural mechanics laboratory of Sakarya University. The reinforcing system is composed of hybrid multiaxial seismic fabric consisting of alkali resistant glass and polypropylene fibers. The plaster as bonding material used in the specimen’s retrofitting consists of expanded glass granular. In order to acquire exact measuring data about the failure behavior of the two mortar joints under shear stressing, vertical load-controlled cylinder having force capacity of 50 kN and loading rate of 1.5 mm/min. with an internal inductive displacement transducers is carried out perpendicular to the triplet specimens. In this study, a total of six triplet specimens with textile reinforcement were prepared for these shear bond tests. The three of them were produced as single-sided reinforced triplets with seismic fabric, while the others were strengthened on both sides. In addition, three triplet specimens without retrofitting and plaster were also tested as reference samples. The obtained test results were given in the manner of force-displacement relationships, ductility coefficients and shear strength parameters comparatively. It is concluded that two-side seismic textile applications on masonry elements with relevant plaster have considerably increased the sheer force resistance and the ductility capacity.

Keywords: expanded glass granular, perforated brickwork, retrofitting, seismic fabric, triplet shear tests

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12587 Conditions That Brought Bounce-Back in Southern Europe: An Inter-Temporal and Cross-National Analysis on Female Labour Force Participation with Fuzzy Set Qualitative Comparative Analysis

Authors: A. Onur Kutlu, H. Tolga Bolukbasi

Abstract:

Since the 1990s, governments, international organizations and scholars have drawn increasing attention to the significance of women in the labour force. While advanced industrial countries in North Western Europe and North America have managed to increase female labour force participation (FLFP) in the early post world war two period, emerging economies of the 1970s have only been able to increase FLFP only a decade later. Among these areas, Southern Europe features a wave of remarkable bounce backs in FLFP. However, despite striking similarities between the features in Southern Europe and those in Turkey, Turkey has not been able to pull women into the labour force. Despite a host of institutional similarities, Turkey has failed to reach to the level of her Southern European neighbours. This paper addresses the puzzle why Turkey lag behind in FLFP in comparison to her Southern European neighbours. There are signs showing that FLFP is currently reaching a critical threshold at a time when structural factors may allow a trend. It is not known, however, the constellation of conditions which may bring rising FLFP in Turkey. In order to gain analytical leverage from similar transitions in countries that share similar labour market and welfare state regime characteristics, this paper identifies the conditions in Southern Europe that brought rising FLFP to be able to explore the prospects for Turkey. Second, this paper takes these variables in the fuzzy set Qualitative Comparative Analysis (fsQCA) as conditions which can potentially explain the outcome of rising FLFP in Portugal, Spain, Italy, Greece and Turkey. The purpose here is to identify any causal pathway there may exist that lead to rising FLFP in Southern Europe. In order to do so, this study analyses two time periods in all cases, which represent different periods for different countries. The first period is identified on the basis of low FLFP and the second period on the basis of the transition to significantly higher FLFP. Third, the conditions are treated following the standard procedures in fsQCA, which provide equifinal: two distinct paths to higher levels of FLFP in Southern Europe, each of which may potentially increase FLFP in Turkey. Based on this analysis, this paper proposes that there exist two distinct paths leading to higher levels of FLFP in Southern Europe. Among these paths, salience of left parties emerges as a sufficient condition. In cases where this condition was not present, a second path combining enlarging service sector employment, increased tertiary education among women and increased childcare enrolment rates led to increasing FLFP.

Keywords: female labour force participation, fsQCA, Southern Europe, Turkey

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12586 Flexural Performance of the Sandwich Structures Having Aluminum Foam Core with Different Thicknesses

Authors: Emre Kara, Ahmet Fatih Geylan, Kadir Koç, Şura Karakuzu, Metehan Demir, Halil Aykul

Abstract:

The structures obtained with the use of sandwich technologies combine low weight with high energy absorbing capacity and load carrying capacity. Hence, there is a growing and markedly interest in the use of sandwiches with aluminium foam core because of very good properties such as flexural rigidity and energy absorption capability. The static (bending and penetration) and dynamic (dynamic bending and low velocity impact) tests were already performed on the aluminum foam cored sandwiches with different types of outer skins by some of the authors. In the current investigation, the static three-point bending tests were carried out on the sandwiches with aluminum foam core and glass fiber reinforced polymer (GFRP) skins at different values of support span distances (L= 55, 70, 80, 125 mm) aiming the analyses of their flexural performance. The influence of the core thickness and the GFRP skin type was reported in terms of peak load, energy absorption capacity and energy efficiency. For this purpose, the skins with two different types of fabrics ([0°/90°] cross ply E-Glass Woven and [0°/90°] cross ply S-Glass Woven which have same thickness value of 1.5 mm) and the aluminum foam core with two different thicknesses (h=10 and 15 mm) were bonded with a commercial polyurethane based flexible adhesive in order to combine the composite sandwich panels. The GFRP skins fabricated via Vacuum Assisted Resin Transfer Molding (VARTM) technique used in the study can be easily bonded to the aluminum foam core and it is possible to configure the base materials (skin, adhesive and core), fiber angle orientation and number of layers for a specific application. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, energy efficiency, collapse mechanisms and the effect of the support span length and core thickness. The results of the experimental study showed that the sandwich with the skins made of S-Glass Woven fabrics and with the thicker foam core presented higher mechanical values such as load carrying and energy absorption capacities. The increment of the support span distance generated the decrease of the mechanical values for each type of panels, as expected, because of the inverse proportion between the force and span length. The most common failure types of the sandwiches are debonding of the upper or lower skin and the core shear. The obtained results have particular importance for applications that require lightweight structures with a high capacity of energy dissipation, such as the transport industry (automotive, aerospace, shipbuilding and marine industry), where the problems of collision and crash have increased in the last years.

Keywords: aluminum foam, composite panel, flexure, transport application

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12585 Numerical Investigation on Tsunami Suppression by Submerged Breakwater

Authors: Tasuku Hongo, Hiroya Mamori, Naoya Fukushima, Makoto Yamamoto

Abstract:

A tsunami induced by an earthquake gives a severe disaster in coastal area. As well known, the huge earthquake in Japan 2011 induced a huge tsunami and the tsunami caused serious damage in the Tohoku and Kanto area. Although breakwaters were constructed in the coast to suppress the tsunami, these were collapsed, and it resulted in severe disasters. In order to decrease the tsunami disaster, we propose the submerged breakwaters and investigate its effect on the tsunami behavior by means of numerical simulations. In order to reproduce tsunami and capture its interface, we employed a moving particle method which is one of the Lagragian methods. Different from ordinary breakwaters, the present breakwater is located in the under-sea. An effective installation condition is investigated by the parametric study. The results show that the submerged breakwater can decrease the wave force by the tsunami. Moreover, the combination of two submerged breakwaters can reduce the tsunami safely and effectively. Therefore, the present results give the effective condition of the installation of the under-sea breakwaters and its mechanism.

Keywords: coastal area, tsunami force reduction, MPS method, submerged breakwater

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