Search results for: anisotropic behavior
3427 Investigating the Influence of Solidification Rate on the Microstructural, Mechanical and Physical Properties of Directionally Solidified Al-Mg Based Multicomponent Eutectic Alloys Containing High Mg Alloys
Authors: Fatih Kılıç, Burak Birol, Necmettin Maraşlı
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The directional solidification process is generally used for homogeneous compound production, single crystal growth, and refining (zone refining), etc. processes. The most important two parameters that control eutectic structures are temperature gradient and grain growth rate which are called as solidification parameters The solidification behavior and microstructure characteristics is an interesting topic due to their effects on the properties and performance of the alloys containing eutectic compositions. The solidification behavior of multicomponent and multiphase systems is an important parameter for determining various properties of these materials. The researches have been conducted mostly on the solidification of pure materials or alloys containing two phases. However, there are very few studies on the literature about multiphase reactions and microstructure formation of multicomponent alloys during solidification. Because of this situation, it is important to study the microstructure formation and the thermodynamical, thermophysical and microstructural properties of these alloys. The production process is difficult due to easy oxidation of magnesium and therefore, there is not a comprehensive study concerning alloys containing high Mg (> 30 wt.% Mg). With the increasing amount of Mg inside Al alloys, the specific weight decreases, and the strength shows a slight increase, while due to formation of β-Al8Mg5 phase, ductility lowers. For this reason, production, examination and development of high Mg containing alloys will initiate the production of new advanced engineering materials. The original value of this research can be described as obtaining high Mg containing (> 30% Mg) Al based multicomponent alloys by melting under vacuum; controlled directional solidification with various growth rates at a constant temperature gradient; and establishing relationship between solidification rate and microstructural, mechanical, electrical and thermal properties. Therefore, within the scope of this research, some > 30% Mg containing ternary or quaternary Al alloy compositions were determined, and it was planned to investigate the effects of directional solidification rate on the mechanical, electrical and thermal properties of these alloys. Within the scope of the research, the influence of the growth rate on microstructure parameters, microhardness, tensile strength, electrical conductivity and thermal conductivity of directionally solidified high Mg containing Al-32,2Mg-0,37Si; Al-30Mg-12Zn; Al-32Mg-1,7Ni; Al-32,2Mg-0,37Fe; Al-32Mg-1,7Ni-0,4Si; Al-33,3Mg-0,35Si-0,11Fe (wt.%) alloys with wide range of growth rate (50-2500 µm/s) and fixed temperature gradient, will be investigated. The work can be planned as; (a) directional solidification of Al-Mg based Al-Mg-Si, Al-Mg-Zn, Al-Mg-Ni, Al-Mg-Fe, Al-Mg-Ni-Si, Al-Mg-Si-Fe within wide range of growth rates (50-2500 µm/s) at a constant temperature gradient by Bridgman type solidification system, (b) analysis of microstructure parameters of directionally solidified alloys by using an optical light microscopy and Scanning Electron Microscopy (SEM), (c) measurement of microhardness and tensile strength of directionally solidified alloys, (d) measurement of electrical conductivity by four point probe technique at room temperature (e) measurement of thermal conductivity by linear heat flow method at room temperature.Keywords: directional solidification, electrical conductivity, high Mg containing multicomponent Al alloys, microhardness, microstructure, tensile strength, thermal conductivity
Procedia PDF Downloads 2603426 Times Series Analysis of Depositing in Industrial Design in Brazil between 1996 and 2013
Authors: Jonas Pedro Fabris, Alberth Almeida Amorim Souza, Maria Emilia Camargo, Suzana Leitão Russo
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With the law Nº. 9279, of May 14, 1996, the Brazilian government regulates rights and obligations relating to industrial property considering the economic development of the country as granting patents, trademark registration, registration of industrial designs and other forms of protection copyright. In this study, we show the application of the methodology of Box and Jenkins in the series of deposits of industrial design at the National Institute of Industrial Property for the period from May 1996 to April 2013. First, a graphical analysis of the data was done by observing the behavior of the data and the autocorrelation function. The best model found, based on the analysis of charts and statistical tests suggested by Box and Jenkins methodology, it was possible to determine the model number for the deposit of industrial design, SARIMA (2,1,0)(2,0,0), with an equal to 9.88% MAPE.Keywords: ARIMA models, autocorrelation, Box and Jenkins Models, industrial design, MAPE, time series
Procedia PDF Downloads 5443425 Artificial Neural Networks Based Calibration Approach for Six-Port Receiver
Authors: Nadia Chagtmi, Nejla Rejab, Noureddine Boulejfen
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This paper presents a calibration approach based on artificial neural networks (ANN) to determine the envelop signal (I+jQ) of a six-port based receiver (SPR). The memory effects called also dynamic behavior and the nonlinearity brought by diode based power detector have been taken into consideration by the ANN. Experimental set-up has been performed to validate the efficiency of this method. The efficiency of this approach has been confirmed by the obtained results in terms of waveforms. Moreover, the obtained error vector magnitude (EVM) and the mean absolute error (MAE) have been calculated in order to confirm and to test the ANN’s performance to achieve I/Q recovery using the output voltage detected by the power based detector. The baseband signal has been recovered using ANN with EVMs no higher than 1 % and an MAE no higher than 17, 26 for the SPR excited different type of signals such QAM (quadrature amplitude modulation) and LTE (Long Term Evolution).Keywords: six-port based receiver; calibration, nonlinearity, memory effect, artificial neural network
Procedia PDF Downloads 773424 A Literature Review of Servant Leadership and Criticism of Advanced Research
Authors: So-Jung Kim, Kyoung-Seok Kim, Yeong-Gyeong Choi
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Although there are many theories and discussion of leadership, the necessity of having a new leadership paradigm was emphasized. The existing leadership characteristic of instruction and control revealed its limitations. Market competition becomes fierce and economic recession never ends worldwide. Of the leadership theories, servant leadership was introduced recently and is in line with the environmental changes of the organization. Servant leadership is a combination of two words, 'servant' and 'leader' and can be defined as the role of the leader who focuses on doing voluntary work for others with altruistic ethics, makes members, customers, and local communities a priority, and makes a commitment to satisfying their needs. This leadership received attention as one field of leadership in the late 1990s and secured its legitimacy. This study discusses the existing research trends of leadership, the concept, behavior characteristics, and lower dimensions of servant leadership, compares servant leadership with the existing leadership researches and diagnoses if servant leadership is a useful concept for further leadership researches. Finally, this study criticizes the limitations in the existing researches on servant leadership.Keywords: leadership philosophy, leadership theory, servant leadership, traditional leadership
Procedia PDF Downloads 3633423 Corrosion Inhibition of Copper in 1M HNO3 Solution by Oleic Acid
Authors: S. Nigri, R. Oumeddour, F. Djazi
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The inhibition of the corrosion of copper in 1 M HNO3 solution by oleic acid was investigated by weight loss measurement, potentiodynamic polarization and scanning electron microscope (SEM) studies. The experimental results have showed that this compound revealed a good corrosion inhibition and the inhibition efficiency is increased with the inhibitor concentration to reach 98%. The results obtained revealed that the adsorption of the inhibitor molecule onto metal surface is found to obey Langmuir adsorption isotherm. The temperature effect on the corrosion behavior of copper in 1 M HNO3 without and with inhibitor at different concentration was studied in the temperature range from 303 to 333 K and the kinetic parameters activation such as Ea, ∆Ha and ∆Sa were evaluated. Tafel plot analysis revealed that oleic acid acts as a mixed type inhibitor. SEM analysis substantiated the formation of protective layer over the copper surface.Keywords: oleic acid, weight loss, electrochemical measurement, SEM analysis
Procedia PDF Downloads 3953422 Clustered Regularly Interspaced Short Palindromic Repeats Interference (CRISPRi): An Approach to Inhibit Microbial Biofilm
Authors: Azna Zuberi
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Biofilm is a sessile bacterial accretion in which bacteria adapts different physiological and morphological behavior from planktonic form. It is the root cause of about 80% microbial infections in human. Among them, E. coli biofilms are most prevalent in medical devices associated nosocomial infections. The objective of this study was to inhibit biofilm formation by targeting LuxS gene, involved in quorum sensing using CRISPRi. luxS is a synthase, involved in the synthesis of Autoinducer-2(AI-2), which in turn guides the initial stage of biofilm formation. To implement CRISPRi system, we have synthesized complementary sgRNA to target gene sequence and co-expressed with dCas9. Suppression of luxS was confirmed through qRT-PCR. The effect of luxS gene on biofilm inhibition was studied through crystal violet assay, XTT reduction assay and scanning electron microscopy. We conclude that CRISPRi system could be a potential strategy to inhibit bacterial biofilm through mechanism base approach.Keywords: biofilm, CRISPRi, luxS, microbial
Procedia PDF Downloads 1833421 After-Cooling Analysis of RC Structural Members Exposed to High Temperature by Using Numerical Approach
Authors: Ju-Young Hwang, Hyo-Gyoung Kwak
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This paper introduces a numerical analysis method for reinforced-concrete (RC) structures exposed to fire and compares the result with experimental results. The proposed analysis method for RC structure under the high temperature consists of two procedures. First step is to decide the temperature distribution across the section through the heat transfer analysis by using the time-temperature curve. After determination of the temperature distribution, the nonlinear analysis is followed. By considering material and geometrical nonlinearity with the temperature distribution, nonlinear analysis predicts the behavior of RC structure under the fire by the exposed time. The proposed method is validated by the comparison with the experimental results. Finally, prediction model to describe the status of after-cooling concrete can also be introduced based on the results of additional experiment. The product of this study is expected to be embedded for smart structure monitoring system against fire in u-City.Keywords: RC, high temperature, after-cooling analysis, nonlinear analysis
Procedia PDF Downloads 4143420 Production and Characterization of Implant Material Produced by Using Electroless Ni Plated Al2O3-Co-Cr-Ti Powders
Authors: Ahmet Yonetken, Ayhan Erol
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The microstructure, mechanical properties and corrosion characteristics of Ni plated %10Al2O3-%40Co-%20Cr and %10Ti powders were investigated using specimens produced by tube furnace sintering at 800-1200°C temperature. A uniform nickel layer on Al2O3-Co-Cr and Ti powders was deposited prior to sintering using electroless plating technique. A composite consisting of quintet additions, a metallic phase, Ti,Cr and Co including a ceramic phase, alumina, within a matrix of Ni has been prepared under Ar shroud and then tube furnace sintered. XRD, SEM (Scanning Electron Microscope), corrosion behavior in acidic media were investigated to characterize the properties of the specimens. Experimental results carried out for composition (%10Al2O3-%40Co-%20Cr- %10Ti)20Ni at 1200°C suggest that the best properties as 312.18HV were obtained at 1200°C.Keywords: sintering, intermetallic, Electroless nickel plating, composite
Procedia PDF Downloads 5743419 Modeling of Compaction Curves for CCA-Cement Stabilized Lateritic Soils
Authors: O. Ahmed Apampa, Yinusa, A. Jimoh
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The aim of this study was to develop an appropriate model for predicting the compaction behavior of lateritic soils and corn cob ash (CCA) stabilized lateritic soils. This was done by first adopting an equation earlier developed for fine-grained soils and subsequent adaptation by others and extending it to modified lateritic soil through the introduction of alpha and beta parameters which are polynomial functions of the CCA binder input. The polynomial equations were determined with MATLAB R2011 curve fitting tool, while the alpha and beta parameters were determined by standard linear programming techniques using the Solver function of Microsoft Excel 2010. The model so developed was a good fit with a correlation coefficient R2 value of 0.86. The paper concludes that it is possible to determine the optimum moisture content and the maximum dry density of CCA stabilized soils from the compaction test of the unmodified soil, and recommends that this procedure is extended to other binder stabilized lateritic soils to facilitate quick decision making in roadworks.Keywords: compaction, corn cob ash, lateritic soil, stabilization
Procedia PDF Downloads 5333418 Factors Influencing the Resistance of the Purchase of Organic Food and Market Education Process in Indonesia
Authors: Fety Nurlia Muzayanah, Arif Imam Suroso, Mukhamad Najib
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The market share of organic food in Indonesia just reaches 0.5-2 percents from the entire of agricultural products. The aim of this research is to analyze the relation of gender, work, age and final education toward the buying interest of organic food, to identify the factors influencing the resistance of the purchase of organic food, and to identify the market education process. The analysis result of Structural Equation Modeling (SEM) shows the factors causing the resistance of the purchase of organic food are the negative attitude toward organic food, the lack of affordable in range for organic food product and the lack of awareness toward organic food, while the subjective norms have no significant effect toward the buying interest. The market education process which can be done is the education about the use of the health of organic food, the organic certification and the economic value.Keywords: market education, organic food, consumer behavior, structural equation modeling
Procedia PDF Downloads 6133417 Improvement on a CNC Gantry Machine Structure Design for Higher Machining Speed Capability
Authors: Ahmed A. D. Sarhan, S. R. Besharaty, Javad Akbaria, M. Hamdi
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The capability of CNC gantry milling machines in manufacturing long components has caused the expanded use of such machines. On the other hand, the machines’ gantry rigidity can reduce under severe loads or vibration during operation. Indeed, the quality of machining is dependent on the machine’s dynamic behavior throughout the operating process. For this reason, this type of machines has always been used prudently and are non efficient. Therefore, they can usually be employed for rough machining and may not produce adequate surface finishing. In this paper, a CNC gantry milling machine with the potential to produce good surface finish has been designed and analyzed. The lowest natural frequency of this machine is 202 Hz at all motion amplitudes with a full range of suitable frequency responses. Meanwhile, the maximum deformation under dead loads for the gantry machine is 0.565µm, indicating that this machine tool is capable of producing higher product quality.Keywords: frequency response, finite element, gantry machine, gantry design, static and dynamic analysis
Procedia PDF Downloads 3573416 Tools for Analysis and Optimization of Standalone Green Microgrids
Authors: William Anderson, Kyle Kobold, Oleg Yakimenko
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Green microgrids using mostly renewable energy (RE) for generation, are complex systems with inherent nonlinear dynamics. Among a variety of different optimization tools there are only a few ones that adequately consider this complexity. This paper evaluates applicability of two somewhat similar optimization tools tailored for standalone RE microgrids and also assesses a machine learning tool for performance prediction that can enhance the reliability of any chosen optimization tool. It shows that one of these microgrid optimization tools has certain advantages over another and presents a detailed routine of preparing input data to simulate RE microgrid behavior. The paper also shows how neural-network-based predictive modeling can be used to validate and forecast solar power generation based on weather time series data, which improves the overall quality of standalone RE microgrid analysis.Keywords: microgrid, renewable energy, complex systems, optimization, predictive modeling, neural networks
Procedia PDF Downloads 2823415 Three-Dimensional Numerical Simulation of Drops Suspended in Poiseuille Flow: Effect of Reynolds Number
Authors: A. Nourbakhsh
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A finite difference/front tracking method is used to study the motion of three-dimensional deformable drops suspended in plane Poiseuille flow at non-zero Reynolds numbers. A parallel version of the code was used to study the behavior of suspension on a reasonable grid resolution (grids). The viscosity and density of drops are assumed to be equal to that of the suspending medium. The effect of the Reynolds number is studied in detail. It is found that drops with small deformation behave like rigid particles and migrate to an equilibrium position about half way between the wall and the center line (the Segre-Silberberg effect). However, for highly deformable drops there is a tendency for drops to migrate to the middle of the channel, and the maximum concentration occurs at the center line. The effective viscosity of suspension and the fluctuation energy of the flow across the channel increases with the Reynolds number of the flow.Keywords: suspensions, Poiseuille flow, effective viscosity, Reynolds number
Procedia PDF Downloads 3553414 X-Ray Photoelectron Spectroscopy Characterization of the Surface Layer on Inconel 625 after Exposition in Molten Salt
Authors: Marie Kudrnova, Jana Petru
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This study is part of the international research - Materials for Molten Salt Reactors (MSR) and addresses the part of the project dealing with the corrosion behavior of candidate construction materials. Inconel 625 was characterized by x-ray photoelectron spectroscopy (XPS) before and after high–temperature experiment in molten salt. The experiment was performed in a horizontal tube furnace molten salt reactor, at 450 °C in argon, at atmospheric pressure, for 150 hours. Industrially produced HITEC salt was used (NaNO3, KNO3, NaNO2). The XPS study was carried out using the ESCAProbe P apparatus (Omicron Nanotechnology Ltd.) equipped with a monochromatic Al Kα (1486.6 eV) X-ray source. The surface layer on alloy 625 after exposure contains only Na, C, O, and Ni (as NiOx) and Nb (as NbOx BE 206.8 eV). Ni was detected in the metallic state (Ni0 – Ni 2p BE-852.7 eV, NiOx - Ni 2p BE-854.7 eV) after a short Ar sputtering because the oxide layer on the surface was very thin. Nickel oxides can form a protective layer in the molten salt, but only future long-term exposures can determine the suitability of Inconel 625 for MSR.Keywords: Inconel 625, molten salt, oxide layer, XPS
Procedia PDF Downloads 1413413 Secure Intelligent Information Management by Using a Framework of Virtual Phones-On Cloud Computation
Authors: Mohammad Hadi Khorashadi Zadeh
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Many new applications and internet services have been emerged since the innovation of mobile networks and devices. However, these applications have problems of security, management, and performance in business environments. Cloud systems provide information transfer, management facilities, and security for virtual environments. Therefore, an innovative internet service and a business model are proposed in the present study for creating a secure and consolidated environment for managing the mobile information of organizations based on cloud virtual phones (CVP) infrastructures. Using this method, users can run Android and web applications in the cloud which enhance performance by connecting to other CVP users and increases privacy. It is possible to combine the CVP with distributed protocols and central control which mimics the behavior of human societies. This mix helps in dealing with sensitive data in mobile devices and facilitates data management with less application overhead.Keywords: BYOD, mobile cloud computing, mobile security, information management
Procedia PDF Downloads 3173412 Stigmatisation of People Living with HIV/AIDS as an Obstacle to Prevention of HIV
Authors: Vicent Lwanga
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Background: Despite sensitization workshops that have been going on in rural areas in Kapchorwa District in Uganda to prevent stigmatization of People Living With HIV/AIDS (PLWHA), interview with PLWHA sows that they are still being stigmatized. This behavior of some people within the community possesses a serious danger to the successful prevention and control of HIV in our society. Evidence exists that some people still believe that eating, living together, and even discussing with PLWHA might make them infected, too, despite all persuasions against such attitude. Description: A face to face interview with some selected PLWHA in Kapchorwa, testified that stigmatization against those who have disclosed their status still lingers on. The interviews with the PLWHA reveals that people still believe that they are being bewitched and cursed by God for their sins, and as such, people keep away from them to avoid the wrath of God. Findings: The more the stigmatization against the PLWHA persists, the more difficult it will be to successfully prevent, control, and eradicate HIV in the society. This is because many PLWHA would prefer not to be identified if they are not shown love and care. Conclusion: A more continuous campaign to stop the stigmatization of PLWHA needs to be on-going. This could be done more effectively by Community-Based Organisations (CBOs) with workshops, print media, and seminars.Keywords: aids, community, HIV, stigma
Procedia PDF Downloads 1583411 Theoretical and ML-Driven Identification of a Mispriced Credit Risk
Authors: Yuri Katz, Kun Liu, Arunram Atmacharan
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Due to illiquidity, mispricing on Credit Markets is inevitable. This creates huge challenges to banks and investors as they seek to find new ways of risk valuation and portfolio management in a post-credit crisis world. Here, we analyze the difference in behavior of the spread-to-maturity in investment and high-yield categories of US corporate bonds between 2014 and 2023. Deviation from the theoretical dependency of this measure in the universe under study allows to identify multiple cases of mispriced credit risk. Remarkably, we observe mispriced bonds in both categories of credit ratings. This identification is supported by the application of the state-of-the-art machine learning model in more than 90% of cases. Noticeably, the ML-driven model-based forecasting of a category of bond’s credit ratings demonstrate an excellent out-of-sample accuracy (AUC = 98%). We believe that these results can augment conventional valuations of credit portfolios.Keywords: credit risk, credit ratings, bond pricing, spread-to-maturity, machine learning
Procedia PDF Downloads 803410 The Optimisation of Salt Impregnated Matrices as Potential Thermochemical Storage Materials
Authors: Robert J. Sutton, Jon Elvins, Sean Casey, Eifion Jewell, Justin R. Searle
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Thermochemical storage utilises chemical salts which store and release energy a fully reversible endo/exothermic chemical reaction. Highly porous vermiculite impregnated with CaCl2, LiNO3 and MgSO4 (SIMs – Salt In Matrices) are proposed as potential materials for long-term thermochemical storage. The behavior of these materials during typical hydration and dehydration cycles is investigated. A simple moisture experiment represents the hydration, whilst thermogravimetric analysis (TGA) represents the dehydration. Further experiments to approximate the energy density and to determine the peak output temperatures of the SIMs are conducted. The CaCl2 SIM is deemed the best performing SIM across most experiments, whilst the results of MgSO4 SIM indicate difficulty associated with energy recovery.Keywords: hydrated states, inter-seasonal heat storage, moisture sorption, salt in matrix
Procedia PDF Downloads 5543409 Meeting User’s Information Need: A Study on the Acceptance of Mobile Library Service at UGM Library
Authors: M. Fikriansyah Wicaksono, Rafael Arief Budiman, M. Very Setiawan
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Currently, a wide range of innovative mobile library (M-Library) service is provided for the users in the library. The M-Library service is an innovation that aims to bring the collections of the library to users who currently use their smartphone so often. With M-Library services, it is expected that the users can fulfill their information needs more conveniently and practically. This study aims to find out how users use M-Library services provided by UGM library. This study applied a quantitative approach to investigate how to use the application M-Library. The Technology Acceptance Model (TAM) theory is applied to perform the analysis in terms of perceived usefulness, perceived ease of use, attitude towards behavior, behavioral intention and actual system usage. The results show that overall the users found that the M-Library application is useful to meet their information needs. Such as facilitate user to access e-resources, search UGM library collections, online booking collections, and reminder for returning book.Keywords: m-library, mobile library services, technology acceptance, library of UGM
Procedia PDF Downloads 2293408 Exploration of Competitive Athletes’ Superstition in Taiwan: "Miracle" and "Coincidence"
Authors: Shieh Shiow-fang
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Superstitious thoughts or actions often occur during athletic competitions. Often "superstitious rituals" have a positive impact on the performance of competitive athletes. Athletes affirm the many psychological benefits of religious beliefs mostly in a positive way. Method: By snowball sampling, we recruited 10 experienced competitive athletes as participants. We used in-person and online one-to-one in-depth interview to collect their experiences about sport superstition. The total interview time was 795 minutes. We analyzed the raw data with the grounded theory processes suggested by Strauss and Corbin (1990). Results: The factors affecting athlete performance are ritual beliefs, taboo awareness, learning norms, and spontaneous attribution behaviors. Conclusion: We concluded that sports superstition reflects several psychological implications. The analysis results of this paper can provide another research perspective for the future study of sports superstition behavior.Keywords: superstition, taboo awareness, learning norms, competitive athlete
Procedia PDF Downloads 863407 The Physics of Turbulence Generation in a Fluid: Numerical Investigation Using a 1D Damped-MNLS Equation
Authors: Praveen Kumar, R. Uma, R. P. Sharma
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This study investigates the generation of turbulence in a deep-fluid environment using a damped 1D-modified nonlinear Schrödinger equation model. The well-known damped modified nonlinear Schrödinger equation (d-MNLS) is solved using numerical methods. Artificial damping is added to the MNLS equation, and turbulence generation is investigated through a numerical simulation. The numerical simulation employs a finite difference method for temporal evolution and a pseudo-spectral approach to characterize spatial patterns. The results reveal a recurring periodic pattern in both space and time when the nonlinear Schrödinger equation is considered. Additionally, the study shows that the modified nonlinear Schrödinger equation disrupts the localization of structure and the recurrence of the Fermi-Pasta-Ulam (FPU) phenomenon. The energy spectrum exhibits a power-law behavior, closely following Kolmogorov's spectra steeper than k⁻⁵/³ in the inertial sub-range.Keywords: water waves, modulation instability, hydrodynamics, nonlinear Schrödinger's equation
Procedia PDF Downloads 733406 Investigations on the Fatigue Behavior of Welded Details with Imperfections
Authors: Helen Bartsch, Markus Feldmann
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The dimensioning of steel structures subject to fatigue loads, such as wind turbines, bridges, masts and towers, crane runways and weirs or components in crane construction, is often dominated by fatigue verification. The fatigue details defined by the welded connections, such as butt or cruciform joints, longitudinal welds, welded-on or welded-in stiffeners, etc., are decisive. In Europe, the verification is usually carried out according to EN 1993-1-9 on a nominal stress basis. The basis is the detailed catalog, which specifies the fatigue strength of the various weld and construction details according to fatigue classes. Until now, a relation between fatigue classes and weld imperfection sizes is not included. Quality levels for imperfections in fusion-welded joints in steel, nickel, titanium and their alloys are regulated in EN ISO 5817, which, however, doesn’t contain direct correlations to fatigue resistances. The question arises whether some imperfections might be tolerable to a certain extent since they may be present in the test data used for detail classifications dating back decades ago. Although current standardization requires proof of satisfying limits of imperfection sizes, it would also be possible to tolerate welds with certain irregularities if these can be reliably quantified by non-destructive testing. Fabricators would be prepared to undertake carefully and sustained weld inspection in view of the significant economic consequences of such unfavorable fatigue classes. This paper presents investigations on the fatigue behavior of common welded details containing imperfections. In contrast to the common nominal stress concept, local fatigue concepts were used to consider the true stress increase, i.e., local stresses at the weld toe and root. The actual shape of a weld comprising imperfections, e.g., gaps or undercuts, can be incorporated into the fatigue evaluation, usually on a numerical basis. With the help of the effective notch stress concept, the fatigue resistance of detailed local weld shapes is assessed. Validated numerical models serve to investigate notch factors of fatigue details with different geometries. By utilizing parametrized ABAQUS routines, detailed numerical studies have been performed. Depending on the shape and size of different weld irregularities, fatigue classes can be defined. As well load-carrying welded details, such as the cruciform joint, as non-load carrying welded details, e.g., welded-on or welded-in stiffeners, are regarded. The investigated imperfections include, among others, undercuts, excessive convexity, incorrect weld toe, excessive asymmetry and insufficient or excessive throat thickness. Comparisons of the impact of different imperfections on the different types of fatigue details are made. Moreover, the influence of a combination of crucial weld imperfections on the fatigue resistance is analyzed. With regard to the trend of increasing efficiency in steel construction, the overall aim of the investigations is to include a more economical differentiation of fatigue details with regard to tolerance sizes. In the long term, the harmonization of design standards, execution standards and regulations of weld imperfections is intended.Keywords: effective notch stress, fatigue, fatigue design, weld imperfections
Procedia PDF Downloads 2603405 Examining the Effects of Ticket Bundling Strategies and Team Identification on Purchase of Hedonic and Utilitarian Options
Authors: Young Ik Suh, Tywan G. Martin
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Bundling strategy is a common marketing practice today. In the past decades, both academicians and practitioners have increasingly emphasized the strategic importance of bundling in today’s markets. The reason for increased interest in bundling strategy is that they normally believe that it can significantly increase profits on organization’s sales over time and it is convenient for the customer. However, little efforts has been made on ticket bundling and purchase considerations in hedonic and utilitarian options in sport consumer behavior context. Consumers often face choices between utilitarian and hedonic alternatives in decision making. When consumers purchase certain products, they are only interested in the functional dimensions, which are called utilitarian dimensions. On the other hand, others focus more on hedonic features such as fun, excitement, and pleasure. Thus, the current research examines how utilitarian and hedonic consumption can vary in typical ticket purchasing process. The purpose of this research is to understand the following two research themes: (1) the differential effect of discount framing on ticket bundling: utilitarian and hedonic options and (2) moderating effect of team identification on ticket bundling. In order to test the research hypotheses, an experimental study using a two-way ANOVA, 3 (team identification: low, medium, and high) X 2 (discount frame: ticket bundle sales with utilitarian product, and hedonic product), with mixed factorial design will be conducted to determine whether there is a statistical significance between purchasing intentions of two discount frames of ticket bundle sales within different team identification levels. To compare mean differences among the two different settings, we will create two conditions of ticket bundles: (1) offering a discount on a ticket ($5 off) if they would purchase it along with utilitarian product (e.g., iPhone8 case, t-shirt, cap), and (2) offering a discount on a ticket ($5 off) if they would purchase it along with hedonic product (e.g., pizza, drink, fans featured on big screen). The findings of the current ticket bundling study are expected to have many theoretical and practical contributions and implications by extending the research and literature pertaining to the relationship between team identification and sport consumer behavior. Specifically, this study can provide a reliable and valid framework to understanding the role of team identification as a moderator on behavioral intentions such as purchase intentions. From an academic perspective, the study will be the first known attempt to understand consumer reactions toward different discount frames related to ticket bundling. Even though the game ticket itself is the major commodity of sport event attendance and significantly related to teams’ revenue streams, most recent ticket pricing research has been done in terms of economic or cost-oriented pricing and not from a consumer psychological perspective. For sport practitioners, this study will also provide significant implications. The result will imply that sport marketers may need to develop two different ticketing promotions for loyal fan and non-loyal fans. Since loyal fans concern ticket price than tie-in products when they see ticket bundle sales, advertising campaign should be more focused on discounting ticket price.Keywords: ticket bundling, hedonic, utilitarian, team identification
Procedia PDF Downloads 1663404 The Effect of Opening on Mode Shapes and Frequencies of Composite Shear Wall
Authors: A. Arabzadeh, H. R. Kazemi Nia Korrani
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Composite steel plate shear wall is a lateral loading resistance system, which is used especially in tall buildings. This wall is made of a thin steel plate with reinforced a concrete cover, which is attached to one or both sides of the steel plate. This system is similar to stiffened steel plate shear wall, in which reinforced concrete replaces the steel stiffeners. Composite shear wall have in-plane and out-plane significant strength. Also, they have appropriate ductility. The present numerical investigations were focused on the effects of opening on wall mode shapes. In addition, frequencies of composite shear wall with and without opening are compared. For analyzing composite shear wall, a new program will be developed using of finite element theory and the effects of shape, size and position openings on the behavior of composite shear wall will be studied. Results indicated that the existence of opening decreases wall frequency.Keywords: composite shear wall, opening, finite element method, modal analysis
Procedia PDF Downloads 5403403 Analyzing Corporate Governance Disclosures in Type II Agency Problems in Indonesia
Authors: Martin S. Mulyadi
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This research investigates the corporate governance disclosure behavior of Indonesian corporations with type II agency problems. The primary cause of the 1990s Asian financial crisis has been attributed to poor corporate governance practices in Indonesia. Most importantly, these poor practices were commonly found in family-owned and government-owned corporations. There are a lot of publicly listed family-owned and government-owned corporations in Indonesia. Agency theory refers to these corporations as corporations with type II agency problems. This research employs agency theory to analyzes corporate governance practice and disclosures in such settings and found that government-owned corporations perform better than family-owned corporations.Keywords: corporate governance, corporate disclosures, agency theory, type II agency problems
Procedia PDF Downloads 1413402 The Need for Educational Psychology in Teacher Education for Sustainable Transformation and Security in Nigeria
Authors: Kaltume Kabir Sharrif
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Teacher education is the bedrock of educational growth and development of any nation. With development in education all human problems can be overcome. Educational Psychology, on the other hand, is in a strategic position for any programme in teacher education to be successful hence other aspects of societal issues. In other words, no teacher education can be of any help in ensuring transformation and security without adequate study in Educational Psychology. Without adequate knowledge and skills in Educational Psychology the teacher may not function effectively in the course of discharging his duty. It is in view of this, that the paper discusses some aspects of Educational Psychology that are of paramount importance in teacher education for sustainable transformation and security of Nigeria. Some recommendations were offered on the role educational psychology play in resolving security challenges facing the country. These include enriching educational psychology with topics from forensic psychology that will provide the teacher the skills of fighting crime in the school, Behavioural Science Unit should be established in each school to monitor the behavior of students, among others.Keywords: transformation, security challenges, teacher education, educational psychology
Procedia PDF Downloads 5063401 Barriers and Strategies for Effective Communication between Parents and Children in the Family
Authors: Sadhana Ghnayiem
Abstract:
This article deals with the issue of effective communication between parents and children and its impact on the family in general and on the child in particular. The aim of this article is to provide information to parents, students, anyone interested in family communication between parents and children, and to provide them with tools to deal with barriers to communication in the family unit. The article presented a literature review of the importance of effective communication in the family, the definition of the concept of communication, and was a reference to factors and barriers in communication between parents and children leading to conflict destructive to the extent that barriers to effective communication in the family unit. At the end of the article, strategies were introduced to motivate children to behave appropriately, and to equip parents best to foster the healthy development of their children when they can create an atmosphere of effective communication. From the literature review, it's found that effective communication between parents and children prevents problematic behavior and helps children understand how to communicate effectively with others. Communication between parents and children is the cornerstone of a happy family life and is the basis for positive interactions between parents and children and increases self-esteem in children.Keywords: children, communication, conflict, family
Procedia PDF Downloads 1963400 Scaling Strategy of a New Experimental Rig for Wheel-Rail Contact
Authors: Meysam Naeimi, Zili Li, Rolf Dollevoet
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A new small–scale test rig developed for rolling contact fatigue (RCF) investigations in wheel–rail material. This paper presents the scaling strategy of the rig based on dimensional analysis and mechanical modelling. The new experimental rig is indeed a spinning frame structure with multiple wheel components over a fixed rail-track ring, capable of simulating continuous wheel-rail contact in a laboratory scale. This paper describes the dimensional design of the rig, to derive its overall scaling strategy and to determine the key elements’ specifications. Finite element (FE) modelling is used to simulate the mechanical behavior of the rig with two sample scale factors of 1/5 and 1/7. The results of FE models are compared with the actual railway system to observe the effectiveness of the chosen scales. The mechanical properties of the components and variables of the system are finally determined through the design process.Keywords: new test rig, rolling contact fatigue, rail, small scale
Procedia PDF Downloads 4843399 The Mechanical Behavior of a Cement-Fiber Composite Material
Authors: K. Harrat, M. Hidjeb, M. T’kint
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The aim of the present research work is to characterize a cement palm date fiber composite in order to be used in isolation and in the manufacture of new structural materials. This technique may possibly participate seriously in the preservation of the environment and develop a growing need for plant products. On one hand, It has been shown that the presence of natural fiber in the composite materials manufacture, based on hydraulic binder, has improved the mechanical behaviour of the material. On the Other hand, It has been proven that the durability of composite materials reinforced with untreated fibers was largely affected by the presence of organic matter. In order to extract the organic material, the fibers were treated with boiling water and then coated with different types of products. A considerable improvement in the sensitivity to water of the fibers, as well as in the mechanical strength and in the ductility of the composite material was observed. The fiber being sensitive to water, the study put the emphasis on its dimensional stability.Keywords: cement composite, durability, heat treatment, mechanical behaviour, vegetal fiber
Procedia PDF Downloads 4543398 Intended and Unintended Outcomes of Partnerships at the Local Level in Slovakia
Authors: Daniel Klimovský
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Slovakia belongs to the most fragmented countries if one looks at its local government structure. The Slovak central governments implemented both broad devolution and fiscal decentralization some decades ago. However, neither territorial consolidation nor size categorization of local competences and powers has been implemented yet. Taking this fact into account, it is clear that the local governments are challenged not only by their citizens as customers but also by effectiveness as well as efficiency of delivered services. The paper is focused on behavior of the local governments in Slovakia and their approaches towards other local partners, including other local governments. Analysis of set of interviews shows that inter-municipal cooperation is the most common local partnership in Slovakia, but due to diversity of the local governments, this kind of cooperation leads to both intended and unintended outcomes. While in many cases the local governments are more efficient as well as effective in delivery of local services thanks to inter-municipal cooperation, there are many cases where inter-municipal cooperation fails, and it brings rather questionable or even negative outcomes.Keywords: local governments, local partnerships, inter-municipal cooperation, delivery of local services
Procedia PDF Downloads 262