Search results for: finite elements method
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 22769

Search results for: finite elements method

20729 An Analysis of Anxious/Depressed Behaviors of Chinese Adolescents

Authors: Zhidong Zhang, Zhi-Chao Zhang, Georgiana Duarte

Abstract:

This study explored early adolescents’ anxious and depressed syndromes in Northeast China. Specifically, the study examined anxious and depressed behaviors and the relationship to education environments. The purpose is to examine how the elements of educational environments and the early adolescents’ behaviors as independent variables influence and possibly predict the early adolescents’ anxious/depressed problems. Achenbach System of Empirically Based Assessment (ASEBA), was the instrument, used in collection of data. A stratified sampling method was utilized to collect data from 2532 participants in seven schools. The results indicated that several background variables influenced anxious/depressed problem. Specifically, age, grade, sports activities and hobbies had a relationship with the anxious/depressed variable.

Keywords: anxious/depressed problems, CBCL, empirically-based assessment, internalizing problems

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20728 Numerical Modeling of the Seismic Site Response in the Firenze Metropolitan Area

Authors: Najmeh Ayoqi, Emanuele Marchetti

Abstract:

OpenSWPC was used to model 2D and 3D seismic waveforms produced by various earthquakes in the Firenze metropolitan area. OpenSWPC is an Opens source code for simulation of seismic wave by using the finite difference method (FDM) in Message Passing Interface (MPI) environment. it considered both earthquake sources, with variable magnitude and location, as well as a pulse source in the modeling domain, which is optimal to simulate local seismic amplification effects. Multiple tests were performed to evaluate the dependence of the frequency content of output modeled waveforms on the model grid size and time steps . Moreover the effect of the velocity structure and absorbing boundary condition on waveform features (amplitude, duration and frequency content) where analysed. Eventually model results are compared with real waveform and Horizontal-to-Vertical spectral Ratio (HVSR) , showing that seismic wave modeling can provide important information on seismic assessment in the city.

Keywords: openSWPC, earthquake, firenze, HVSR, seismic wave

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20727 Introduction of the Fluid-Structure Coupling into the Force Analysis Technique

Authors: Océane Grosset, Charles Pézerat, Jean-Hugh Thomas, Frédéric Ablitzer

Abstract:

This paper presents a method to take into account the fluid-structure coupling into an inverse method, the Force Analysis Technique (FAT). The FAT method, also called RIFF method (Filtered Windowed Inverse Resolution), allows to identify the force distribution from local vibration field. In order to only identify the external force applied on a structure, it is necessary to quantify the fluid-structure coupling, especially in naval application, where the fluid is heavy. This method can be decomposed in two parts, the first one consists in identifying the fluid-structure coupling and the second one to introduced it in the FAT method to reconstruct the external force. Results of simulations on a plate coupled with a cavity filled with water are presented.

Keywords: aeroacoustics, fluid-structure coupling, inverse methods, naval, turbulent flow

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20726 Public Interest Law for Gender Equality: An Exploratory Study of the 'Single Woman Reproductive Rights' Movement in China

Authors: Xiaofei Zhu

Abstract:

As a 'weapon of the weak', the Public Interest Law can provide a better perspective for the cause of gender justice. In recent years, the legal practice of single female reproductive rights in China has already possessed the elements of public interest law activities and the possibility of public interest law operation. Through the general operating procedures of public interest law practice, that is, from the choice of subject, the planning of the case, the operation of the strategy and the later development, the paper analyzes the gains and losses of the legal practice of single female reproductive rights in China, and puts forward some ideas on its possible operation path. On this basis, it is believed that the cause of women's rights should be carried out under the broad human rights perspective; it is necessary to realize the particularity of different types of women's rights protection practice; the practice of public interest law needs to accurately grasp the constituent elements of all aspects of the case, and strive to find the opportunities of institutional and social change; the practice of public welfare law of gender justice should be carried out from a long-term perspective.

Keywords: single women’s reproductive rights, public interest law, gender justice, legal strategies, legal change

Procedia PDF Downloads 141
20725 Design and Analysis of Flexible Slider Crank Mechanism

Authors: Thanh-Phong Dao, Shyh-Chour Huang

Abstract:

This study presents the optimal design and formulation of a kinematic model of a flexible slider crank mechanism. The objective of the proposed innovative design is to take extra advantage of the compliant mechanism and maximize the fatigue life by applying the Taguchi method. A formulated kinematic model is developed using a Pseudo-Rigid-Body Model (PRBM). By means of mathematic models, the kinematic behaviors of the flexible slider crank mechanism are captured using MATLAB software. Finite Element Analysis (FEA) is used to show the stress distribution. The results show that the optimal shape of the flexible hinge includes a force of 8.5N, a width of 9mm and a thickness of 1.1mm. Analysis of variance shows that the thickness of the proposed hinge is the most significant parameter, with an F test of 15.5. Finally, a prototype is manufactured to prepare for testing the kinematic and dynamic behaviors.

Keywords: kinematic behavior, fatigue life, pseudo-rigid-body model, flexible slider crank mechanism

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20724 Gamification in Education: A Case Study on the Use of Serious Games

Authors: Maciej Zareba, Pawel Dawid

Abstract:

This article provides a case study exploring the use of serious games in educational settings, indicating their potential to transform conventional teaching methods into interactive and engaging learning experiences. By incorporating game elements such as points, leaderboards and progress indicators, serious games establish clear goals, provide real-time feedback and give a sense of progress. These elements enable students to solve complex problems in simulated environments, fostering critical thinking, creativity and contextual learning. The article provides a case study of the feasibility of using the 4FactryManager serious game in a selected educational context, demonstrating its effectiveness in increasing student motivation, improving academic performance and promoting knowledge consolidation. The study and presentation are based on the results of industrial research and development work conducted as part of the project titled (4FM) 4FACTORY Manager – an innovative simulation game for managing real production processes using a novel gameplay model based on the interaction between the virtual and real worlds, applying the Industry 4.0 concept (Project number: POIR.01.02.00-00-0057/19).

Keywords: gamification, serious games, education, elearning

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20723 Optimization of High Flux Density Design for Permanent Magnet Motor

Authors: Dong-Woo Kang

Abstract:

This paper presents an optimal magnet shape of a spoke-shaped interior permanent magnet synchronous motor by using ferrite magnets. Generally, the permanent magnet motor used the ferrite magnets has lower output power and efficiency than a rare-earth magnet motor, because the ferrite magnet has lower magnetic energy than the rare-earth magnet. Nevertheless, the ferrite magnet motor is used to many industrial products owing to cost effectiveness. In this paper, the authors propose a high power density design of the ferrite permanent magnet synchronous motor. Furthermore, because the motor design has to be taken a manufacturing process into account, the design is simulated by using the finite element method for analyzing the demagnetization, the magnetizing, and the structure stiffness. Especially, the magnet shape and dimensions are decided for satisfying these properties. Finally, the authors design an optimal motor for applying our system. That final design is manufactured and evaluated from experimentations.

Keywords: demagnetization, design optimization, magnetic analysis, permanent magnet motors

Procedia PDF Downloads 381
20722 Structural Performance Evaluation of Segmented Wind Turbine Blade Through Finite Element Simulation

Authors: Chandrashekhar Bhat, Dilifa Jossley Noronha, Faber A. Saldana

Abstract:

Transportation of long turbine blades from one place to another is a difficult process. Hence a feasibility study of modularization of wind turbine blade was taken from structural standpoint through finite element analysis. Initially, a non-segmented blade is modeled and its structural behavior is evaluated to serve as reference. The resonant, static bending and fatigue tests are simulated in accordance with IEC61400-23 standard for comparison purpose. The non-segmented test blade is separated at suitable location based on trade off studies and the segments are joined with an innovative double strap bonded joint configuration. The adhesive joint is modeled by adopting cohesive zone modeling approach in ANSYS. The developed blade model is analyzed for its structural response through simulation. Performances of both the blades are found to be similar, which indicates that, efficient segmentation of the long blade is possible which facilitates easy transportation of the blades and on site reassembling. The location selected for segmentation and adopted joint configuration has resulted in an efficient segmented blade model which proves the methodology adopted for segmentation was quite effective. The developed segmented blade appears to be the viable alternative considering its structural response specifically in fatigue within considered assumptions.

Keywords: modularization, fatigue, cohesive zone modeling, wind turbine blade

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20721 Nonverbal Signs in Television Advertisements: A Semiotics Perspective

Authors: Yemi Mahmud

Abstract:

Semiotics is the study of signs and symbols as significations in a communication process. Television advertisement combines verbal and nonverbal signs to apprise consumers of products’ deliverables. This makes the language of television advertisement an important area of semiotic research. This paper focuses on nonverbal signs in television advertisement in purposively selected advertisements of two Nivea beauty products television advertisements: New Nivea Natural Fairness and Nivea Natural Fairness Lotion in Nigeria to investigate signs in meaning construction. It studies the interpretative realities of the signification of the nonverbal signs in television advertisements in Nigeria; examining signs in relation to the embedded and contextual meanings they are capable of exhuming vis-a-vis, viewers’ social and cultural senses extrapolated to draw inferences. The paper anchors its research on visual rhetorics and concludes that signs, as nonverbal elements in television advertisements, form part of the entire linguistic system of meaning transmission, noting that interpretations do not rely, solely, on the intrinsic properties of signs as signifiers, but on the imbued sociocultural elements that suggest meaning to viewers.

Keywords: Nivea, nonverbal signs, semiotics, signification, signifiers, television advertisement

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20720 Study of Mixed Convection in a Vertical Channel Filled with a Reactive Porous Medium in the Absence of Local Thermal Equilibrium

Authors: Hamid Maidat, Khedidja Bouhadef, Djamel Eddine Ameziani, Azzedine Abdedou

Abstract:

This work consists of a numerical simulation of convective heat transfer in a vertical plane channel filled with a heat generating porous medium, in the absence of local thermal equilibrium. The walls are maintained to a constant temperature and the inlet velocity is uniform. The dynamic range is described by the Darcy-Brinkman model and the thermal field by two energy equations model. A dimensionless formulation is developed for performing a parametric study based on certain dimensionless groups such as, the Biot interstitial number, the thermal conductivity ratio and the volumetric heat generation. The governing equations are solved using the finite volume method, gave rise to a multitude of results concerning in particular the thermal field in the porous channel and the existence or not of the local thermal equilibrium.

Keywords: local thermal non equilibrium model, mixed convection, porous medium, power generation

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20719 Double-Diffusive Natural Convection with Various Partially Heated and Salted Sources Arrangements in an Open Cavity

Authors: Norazam Arbin, Habibis Saleh, Ammar Alsabery, Ishak Hashim

Abstract:

Double-diffusive natural convection in an open top cavity with partial vertical heating and salting sources is investigated numerically. Different temperatures and concentrations are applied at the source location on the right and left walls while the other remains adiabatic except at the open top surface. Various combinations of sources arrangements are imposed at the vertical walls in order to observe the significant impact to the convection. An iterative finite different method is used to solve the dimensionless governing equations. The effects of Marangoni number and sources arrangements on the contours of streamlines, isotherms, and concentrations are visualized as the outcome of the numerical solutions. The average Nusselt and Sherwood number are presented for various sources arrangements. It is clearly observed that the sources arrangements gave major impact on the heat and mass transfer rates. A horizontal-like pattern is found for sources arrangements that near the top-free surface.

Keywords: double-diffusive, Marangoni effect, partial heating, salting

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20718 Attenuation Scale Calibration of an Optical Time Domain Reflectometer

Authors: Osama Terra, Hatem Hussein

Abstract:

Calibration of Optical Time Domain Reflectometer (OTDR) is crucial for the accurate determination of loss budget for long optical fiber links. In this paper, the calibration of the attenuation scale of an OTDR using two different techniques is discussed and implemented. The first technique is the external modulation method (EM). A setup is proposed to calibrate an OTDR over a dynamic range of around 15 dB based on the EM method. Afterwards, the OTDR is calibrated using two standard reference fibers (SRF). Both SRF are calibrated using cut-back technique; one of them is calibrated at our home institute (the National Institute of Standards – NIS) while the other at the National Physical Laboratory (NPL) of the United Kingdom to confirm our results. In addition, the parameters contributing the calibration uncertainty are thoroughly investigated. Although the EM method has several advantages over the SRF method, the uncertainties in the SRF method is found to surpass that of the EM method.

Keywords: optical time domain reflectometer, fiber attenuation measurement, OTDR calibration, external source method

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20717 Generic Hybrid Models for Two-Dimensional Ultrasonic Guided Wave Problems

Authors: Manoj Reghu, Prabhu Rajagopal, C. V. Krishnamurthy, Krishnan Balasubramaniam

Abstract:

A thorough understanding of guided ultrasonic wave behavior in structures is essential for the application of existing Non Destructive Evaluation (NDE) technologies, as well as for the development of new methods. However, the analysis of guided wave phenomena is challenging because of their complex dispersive and multimodal nature. Although numerical solution procedures have proven to be very useful in this regard, the increasing complexity of features and defects to be considered, as well as the desire to improve the accuracy of inspection often imposes a large computational cost. Hybrid models that combine numerical solutions for wave scattering with faster alternative methods for wave propagation have long been considered as a solution to this problem. However usually such models require modification of the base code of the solution procedure. Here we aim to develop Generic Hybrid models that can be directly applied to any two different solution procedures. With this goal in mind, a Numerical Hybrid model and an Analytical-Numerical Hybrid model has been developed. The concept and implementation of these Hybrid models are discussed in this paper.

Keywords: guided ultrasonic waves, Finite Element Method (FEM), Hybrid model

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20716 Pollution of Cadmium in Green Space of Rasht City and Environmental Health

Authors: Seyed Armin Hashemi, Somayeh Rahimzadeh

Abstract:

The urban green space and environment should be considered to be among the most fundamental elements of the sustainability of natural and human life in the new citizenship. The present research is intended to evaluate the impact of irrigation using urban wastewater of Cadmium (Cd) in the soil and leaves of the pine trees of Rasht in the forest territories of Rasht. For this purpose, following the exact specification of the geographical and topographical attributes of under treatment area, 100 sample trees were implemented randomly –systematically in each compound studied. Approaching the end of growth season, five trees were selected randomly in each of the plats and samples of leaves were collected from the parts near to the end of the crown and the part which was adjacent to the light. At the foot of each of the trees selected, a soil profile was dug and samples of soil were extracted from three depths of 0-20, centimeters. The measurements done in the laboratory showed that the density of nutritious elements of the samples of leaf and soil in the compound irrigated with wastewater .The results of the present research suggest that urban can be used as a source of irrigation whereas muck can be employed in forestation and irrigation with precise and particular supervision and control.

Keywords: irrigation, forestation, urban waste water, pine, wastewater

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20715 Effect of Prefabricated Vertical Drain System Properties on Embankment Behavior

Authors: Seyed Abolhasan Naeini, Ali Namaei

Abstract:

This study presents the effect of prefabricated vertical drain system properties on embankment behavior by calculating the settlement, lateral displacement and induced excess pore pressure by numerical method. In order to investigate this behavior, three different prefabricated vertical drains have been simulated under an embankment. The finite element software PLAXIS has been carried out for analyzing the displacements and excess pore pressures. The results showed that the consolidation time and induced excess pore pressure are highly depended to the discharge capacity of the prefabricated vertical drain. The increase in the discharge capacity leads to decrease the consolidation process and the induced excess pore pressure. Moreover, it was seen that the vertical drains spacing does not have any significant effect on the consolidation time. However, the increase in the drains spacing would decrease the system stiffness.

Keywords: vertical drain, prefabricated, consolidation, embankment

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20714 The Appearance of Identity in the Urban Landscape by Enjoying the Natural Factors

Authors: Mehrdad Karimi, Farshad Negintaji

Abstract:

This study has examined the appearance of identity in the urban landscape and its effects on the natural factors. For this purpose, the components of place identity, emotional attachment, place dependence and social bond which totally constitute place attachment, measures it in three domains of cognitive (place identity), affective (emotional attachment) and behavioral (place dependence and social bond). In order to measure the natural factors, three components of the absolute elements, living entities, natural elements have been measured. The study is descriptive and the statistical population has been Yasouj, a city in Iran. To analyze the data the SPSS software has been used. The results in two level of descriptive and inferential statistics have been investigated. In the inferential statistics, Pearson correlation coefficient test has been used to evaluate the research hypotheses. In this study, the variable of identity is in high level and the natural factors are also in high level. These results indicate a positive relationship between place identity and natural factors. Development of environment and reaching the quality level of the personality or identity will develop the individual and society.

Keywords: identity, place identity, landscape, urban landscape, landscaping

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20713 A Finite Element Model to Study the Behaviour of Corroded Reinforced Concrete Beams Repaired with near Surface Mounted Technique

Authors: B. Almassri, F. Almahmoud, R. Francois

Abstract:

Near surface mounted reinforcement (NSM) technique is one of the promising techniques used nowadays to strengthen reinforced concrete (RC) structures. In the NSM technique, the Carbon Fibre Reinforced Polymer (CFRP) rods are placed inside pre-cut grooves and are bonded to the concrete with epoxy adhesive. This paper studies the non-classical mode of failure ‘the separation of concrete cover’ according to experimental and numerical FE modelling results. Experimental results and numerical modelling results of a 3D finite element (FE) model using the commercial software Abaqus and 2D FE model FEMIX were obtained on two beams, one corroded (25 years of corrosion procedure) and one control (A1CL3-R and A1T-R) were each repaired in bending using NSM CFRP rod and were then tested up to failure. The results showed that the NSM technique increased the overall capacity of control and corroded beams despite a non-classical mode of failure with separation of the concrete cover occurring in the corroded beam due to damage induced by corrosion. Another FE model used external steel stirrups around the repaired corroded beam A1CL3-R which failed with the separation of concrete cover, this model showed a change in the mode of failure form a non-classical mode of failure by the separation of concrete cover to the same mode of failure of the repaired control beam by the crushing of compressed concrete.

Keywords: corrosion, repair, Reinforced Concrete, FEM, CFRP, FEMIX

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20712 Buckling Analysis of 2D Frames Using the Modified Newmark Method

Authors: Seyed Amin Vakili, Sahar Sadat Vakili, Seyed Ehsan Vakili, Nader Abdoli Yazdi

Abstract:

The main purpose of this paper is to present the Modified Newmark Method of buckling analysis frame considering the effect of the axial load. The discussion will be restricted to plane frameworks containing a constant cross-section for each element. In addition, it is assumed that the frames are prevented from out-of-plane deflection. In this method, stiffness matrix of the structure is considered to be constant. The most important advantage of such a method is that it obtains both upper and lower critical loads. The advanced of the present method is fast convergence, ability to use computer simulations, and ability to model structures with semi-rigid support conditions using linear and rotational spring.

Keywords: buckling, stability, frame, modified newmark method

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20711 A Robust Software for Advanced Analysis of Space Steel Frames

Authors: Viet-Hung Truong, Seung-Eock Kim

Abstract:

This paper presents a robust software package for practical advanced analysis of space steel framed structures. The pre- and post-processors of the presented software package are coded in the C++ programming language while the solver is written by using the FORTRAN programming language. A user-friendly graphical interface of the presented software is developed to facilitate the modeling process and result interpretation of the problem. The solver employs the stability functions for capturing the second-order effects to minimize modeling and computational time. Both the plastic-hinge and fiber-hinge beam-column elements are available in the presented software. The generalized displacement control method is adopted to solve the nonlinear equilibrium equations.

Keywords: advanced analysis, beam-column, fiber-hinge, plastic hinge, steel frame

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20710 Analysis of Formation Methods of Range Profiles for an X-Band Coastal Surveillance Radar

Authors: Nguyen Van Loi, Le Thanh Son, Tran Trung Kien

Abstract:

The paper deals with the problem of the formation of range profiles (RPs) for an X-band coastal surveillance radar. Two popular methods, the difference operator method, and the window-based method, are reviewed and analyzed via two tests with different datasets. The test results show that although the original window-based method achieves a better performance than the difference operator method, it has three main drawbacks that are the use of 3 or 4 peaks of an RP for creating the windows, the extension of the window size using the power sum of three adjacent cells in the left and the right sides of the windows and the same threshold applied for all types of vessels to finish the formation process of RPs. These drawbacks lead to inaccurate RPs due to the low signal-to-clutter ratio. Therefore, some suggestions are proposed to improve the original window-based method.

Keywords: range profile, difference operator method, window-based method, automatic target recognition

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20709 Application of the Material Point Method as a New Fast Simulation Technique for Textile Composites Forming and Material Handling

Authors: Amir Nazemi, Milad Ramezankhani, Marian Kӧrber, Abbas S. Milani

Abstract:

The excellent strength to weight ratio of woven fabric composites, along with their high formability, is one of the primary design parameters defining their increased use in modern manufacturing processes, including those in aerospace and automotive. However, for emerging automated preform processes under the smart manufacturing paradigm, complex geometries of finished components continue to bring several challenges to the designers to cope with manufacturing defects on site. Wrinklinge. g. is a common defectoccurring during the forming process and handling of semi-finished textile composites. One of the main reasons for this defect is the weak bending stiffness of fibers in unconsolidated state, causing excessive relative motion between them. Further challenges are represented by the automated handling of large-area fiber blanks with specialized gripper systems. For fabric composites forming simulations, the finite element (FE)method is a longstanding tool usedfor prediction and mitigation of manufacturing defects. Such simulations are predominately meant, not only to predict the onset, growth, and shape of wrinkles but also to determine the best processing condition that can yield optimized positioning of the fibers upon forming (or robot handling in the automated processes case). However, the need for use of small-time steps via explicit FE codes, facing numerical instabilities, as well as large computational time, are among notable drawbacks of the current FEtools, hindering their extensive use as fast and yet efficient digital twins in industry. This paper presents a novel woven fabric simulation technique through the application of the material point method (MPM), which enables the use of much larger time steps, facing less numerical instabilities, hence the ability to run significantly faster and efficient simulationsfor fabric materials handling and forming processes. Therefore, this method has the ability to enhance the development of automated fiber handling and preform processes by calculating the physical interactions with the MPM fiber models and rigid tool components. This enables the designers to virtually develop, test, and optimize their processes based on either algorithmicor Machine Learning applications. As a preliminary case study, forming of a hemispherical plain weave is shown, and the results are compared to theFE simulations, as well as experiments.

Keywords: material point method, woven fabric composites, forming, material handling

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20708 Anti-Intellectualism in Populist Discourse and Its Role in Identity Construction: A Comparative Study between the United States of America and France

Authors: Iuliana-Erika Köpeczi

Abstract:

‘Language is no longer regarded as peripheral to our grasp of the world we live in, but as central to it. Words are not mere vocal labels or communicational adjuncts superimposed upon an already given order of things. They are collective products of social interaction, essential instruments through which human beings constitute and articulate their world’, said Roy Harris. If we were to accept the above-mentioned premise, then we surely must accept that discourse, generally, - and political discourse, specifically -, bears a crucial importance to one’s perception of reality. The way in which political rhetoric constructs reality changes the relationship between the voter and his/her view of the world, which, in turn, influences greatly the future trends of political participation. In this context, our inquiry focuses on the role of populist discourses in the post 9/11 political rhetoric, and how this led to the formation, construction and reconstruction of identity within the ‘us’ vs. ‘them’ dichotomy. It is our hypothesis that anti-intellectualistic elements played a significant role in the manner in which identity construction had been carried out on a discursive level. By adopting a comparative approach, we intend to identify the similarities and differences between the use of such anti-intellectualist elements in the United States of America on one hand – within the discourse of Rick Santorum, – and France on the other – with Marine le Pen’s discourse. Our methodological approach uses close textual analysis of primary source material (discourse analysis); historical contextualization of both primary documents and broader socio-political and cultural framework through archival research and secondary sources; as well as interpretation of primary texts through theoretical frameworks (qualitative research). We hope that the output of our endeavor will be useful in better understanding the different correlations that exist between anti-intellectualism and populism and how the interactions between these two elements aids in political identity construction through discourse.

Keywords: anti-intellectualism, discourse theory, France, identity construction, populism, United States of America

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20707 The Influence of the Discharge Point Position on the Pollutant Dispersion

Authors: Sonia Ben Hamza, Sabra Habli, Nejla Mahjoub Said, Hervé Bournot, Georges Le Palec

Abstract:

The distribution characteristics of pollutants released at different vertical inlet positions of an open channel are investigated with a three-dimensional numerical model. Pollutants are injected from time-dependent sources in a turbulent free surface flow. Numerical computations were carried out using ANSYS Fluent which is based on the finite volume approach. The air/water interface was modeled with the volume of the fluid method (VOF). By focusing on investigating the influences of flow on pollutants, it is found that pollutant released from the bottom position of the channel takes more time to disperse in the longitudinal direction of the flow in comparison with the case of pollutant released near the free surface. On the other hand, the pollutant released from the bottom position generates a vertical dispersion with decreased amplitude. These findings may assist in cost-effective scientific countermeasures to be taken for accident or planned pollutant discharged into a river.

Keywords: numerical simulation, pollutant release, turbulent free surface flow, VOF model

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20706 Fragility Analysis of Weir Structure Subjected to Flooding Water Damage

Authors: Oh Hyeon Jeon, WooYoung Jung

Abstract:

In this study, seepage analysis was performed by the level difference between upstream and downstream of weir structure for safety evaluation of weir structure against flooding. Monte Carlo Simulation method was employed by considering the probability distribution of the adjacent ground parameter, i.e., permeability coefficient of weir structure. Moreover, by using a commercially available finite element program (ABAQUS), modeling of the weir structure is carried out. Based on this model, the characteristic of water seepage during flooding was determined at each water level with consideration of the uncertainty of their corresponding permeability coefficient. Subsequently, fragility function could be constructed based on this response from numerical analysis; this fragility function results could be used to determine the weakness of weir structure subjected to flooding disaster. They can also be used as a reference data that can comprehensively predict the probability of failur,e and the degree of damage of a weir structure.

Keywords: weir structure, seepage, flood disaster fragility, probabilistic risk assessment, Monte-Carlo simulation, permeability coefficient

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20705 Maximum Deformation Estimation for Reinforced Concrete Buildings Using Equivalent Linearization Method

Authors: Chien-Kuo Chiu

Abstract:

In the displacement-based seismic design and evaluation, equivalent linearization method is one of the approximation methods to estimate the maximum inelastic displacement response of a system. In this study, the accuracy of two equivalent linearization methods are investigated. The investigation consists of three soil condition in Taiwan (Taipei Basin 1, 2, and 3) and five different heights of building (H_r= 10, 20, 30, 40, and 50 m). The first method is the Taiwan equivalent linearization method (TELM) which was proposed based on Japanese equivalent linear method considering the modification factor, α_T= 0.85. On the basis of Lin and Miranda study, the second method is proposed with some modification considering Taiwan soil conditions. From this study, it is shown that Taiwanese equivalent linearization method gives better estimation compared to the modified Lin and Miranda method (MLM). The error index for the Taiwanese equivalent linearization method are 16%, 13%, and 12% for Taipei Basin 1, 2, and 3, respectively. Furthermore, a ductility demand spectrum of single-degree-of-freedom (SDOF) system is presented in this study as a guide for engineers to estimate the ductility demand of a structure.

Keywords: displacement-based design, ductility demand spectrum, equivalent linearization method, RC buildings, single-degree-of-freedom

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20704 Design of Geochemical Maps of Industrial City Using Gradient Boosting and Geographic Information System

Authors: Ruslan Safarov, Zhanat Shomanova, Yuri Nossenko, Zhandos Mussayev, Ayana Baltabek

Abstract:

Geochemical maps of distribution of polluting elements V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb on the territory of the Pavlodar city (Kazakhstan), which is an industrial hub were designed. The samples of soil were taken from 100 locations. Elemental analysis has been performed using XRF. The obtained data was used for training of the computational model with gradient boosting algorithm. The optimal parameters of model as well as the loss function were selected. The computational model was used for prediction of polluting elements concentration for 1000 evenly distributed points. Based on predicted data geochemical maps were created. Additionally, the total pollution index Zc was calculated for every from 1000 point. The spatial distribution of the Zc index was visualized using GIS (QGIS). It was calculated that the maximum coverage area of the territory of the Pavlodar city belongs to the moderately hazardous category (89.7%). The visualization of the obtained data allowed us to conclude that the main source of contamination goes from the industrial zones where the strategic metallurgical and refining plants are placed.

Keywords: Pavlodar, geochemical map, gradient boosting, CatBoost, QGIS, spatial distribution, heavy metals

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20703 Spatial Characters Adapted to Rainwater Natural Circulation in Residential Landscape

Authors: Yun Zhang

Abstract:

Urban housing in China is typified by residential districts that occupy 25 to 40 percentage of the urban land. In residential districts, squares, roads, and building facades, as well as plants, usually form a four-grade spatial structure: district entrances, central landscapes, housing cluster entrances, green spaces between dwellings. This spatial structure and its elements not only compose the visible residential landscape but also play a major role of carrying rain water. These elements, therefore, imply ecological significance to urban fitness. Based upon theories of landscape ecology, residential landscape can be understood as a pattern typified by minor soft patch of planted area and major hard patch of buildings and squares, as well as hard corridors of roads. Use five landscape districts in Hangzhou as examples; this paper finds that the size, shape and slope direction of soft patch, the bend of roads, and the form of the four-grade spatial structure are influential for adapting to natural rainwater circulation.

Keywords: Hangzhou China, rainwater, residential landscape, spatial character, urban housing

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20702 Prediction of Unsteady Heat Transfer over Square Cylinder in the Presence of Nanofluid by Using ANN

Authors: Ajoy Kumar Das, Prasenjit Dey

Abstract:

Heat transfer due to forced convection of copper water based nanofluid has been predicted by Artificial Neural network (ANN). The present nanofluid is formed by mixing copper nano particles in water and the volume fractions are considered here are 0% to 15% and the Reynolds number are kept constant at 100. The back propagation algorithm is used to train the network. The present ANN is trained by the input and output data which has been obtained from the numerical simulation, performed in finite volume based Computational Fluid Dynamics (CFD) commercial software Ansys Fluent. The numerical simulation based results are compared with the back propagation based ANN results. It is found that the forced convection heat transfer of water based nanofluid can be predicted correctly by ANN. It is also observed that the back propagation ANN can predict the heat transfer characteristics of nanofluid very quickly compared to standard CFD method.

Keywords: forced convection, square cylinder, nanofluid, neural network

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20701 Suggestion of Two-Step Traction Therapy for Safer and More Effective Conservative Treatment for Low Back Pain

Authors: Won Man Park, Dae Kyung Choi, Kyungsoo Kim, Yoon Hyuk Kim

Abstract:

Traction therapy has been used in the treatment of spinal pain for decades. However, a case study reported the occurrence of large disc protrusion during motorized traction therapy. In this study, we hypothesized that additional local decompression with a global axial traction could be helpful for risk reduction of intervertebral disc damage. A validated three dimensional finite element model of the lumbar spine was used. Two-step traction therapy using the axial global traction (the first step) with 1/3 body weight and the additional local decompression (the second step) with 7 mm translation of L4 spinal bone was determined for the traction therapy. During two-step traction therapy, the sacrum was constrained in all translational directions. Reduced lordosis angle by the global axial traction recovered with the additional local decompression. Stress on fibers of the annulus fibrosus by the axial global traction decreased with the local decompression by 17%~96% in the posterior region of intervertebral disc. Stresses on ligaments except anterior longitudinal ligaments in all motion segments decreased till 4.9 mm~5.6 mm translation of L4 spinal bone. The results of this study showed that the additional local decompression is very useful for reducing risk of damage in the intervertebral disc and ligaments caused by the global axial traction force. Moreover, the local decompression could be used to enhance reduction of intradiscal pressure.

Keywords: lumbar spine, traction-therapy, biomechanics, finite element analysis

Procedia PDF Downloads 488
20700 Simulation Study of the Microwave Heating of the Hematite and Coal Mixture

Authors: Prasenjit Singha, Sunil Yadav, Soumya Ranjan Mohantry, Ajay Kumar Shukla

Abstract:

Temperature distribution in the hematite ore mixed with 7.5% coal was predicted by solving a 1-D heat conduction equation using an implicit finite difference approach. In this work, it was considered a square slab of 20 cm x 20 cm, which assumed the coal to be uniformly mixed with hematite ore. It was solved the equations with the use of MATLAB 2018a software. Heat transfer effects in this 1D dimensional slab convective and the radiative boundary conditions are also considered. Temperature distribution obtained inside hematite slab by considering microwave heating time, thermal conductivity, heat capacity, carbon percentage, sample dimensions, and many other factors such as penetration depth, permittivity, and permeability of coal and hematite ore mixtures. The resulting temperature profile can be used as a guiding tool for optimizing the microwave-assisted carbothermal reduction process of hematite slab was extended to other dimensions as well, viz., 1 cm x 1 cm, 5 cm x 5 cm, 10 cm x 10 cm, 20 cm x 20 cm. The model predictions are in good agreement with experimental results.

Keywords: hematite ore, coal, microwave processing, heat transfer, implicit method, temperature distribution

Procedia PDF Downloads 171