Search results for: anisotropic behavior
3367 An Algorithm for Determining the Arrival Behavior of a Secondary User to a Base Station in Cognitive Radio Networks
Authors: Danilo López, Edwin Rivas, Leyla López
Abstract:
This paper presents the development of an algorithm that predicts the arrival of a secondary user (SU) to a base station (BS) in a cognitive network based on infrastructure, requesting a Best Effort (BE) or Real Time (RT) type of service with a determined bandwidth (BW) implementing neural networks. The algorithm dynamically uses a neural network construction technique using the geometric pyramid topology and trains a Multilayer Perceptron Neural Networks (MLPNN) based on the historical arrival of an SU to estimate future applications. This will allow efficiently managing the information in the BS, since it precedes the arrival of the SUs in the stage of selection of the best channel in CRN. As a result, the software application determines the probability of arrival at a future time point and calculates the performance metrics to measure the effectiveness of the predictions made.Keywords: cognitive radio, base station, best effort, MLPNN, prediction, real time
Procedia PDF Downloads 3313366 A Numerical Investigation of Lamb Wave Damage Diagnosis for Composite Delamination Using Instantaneous Phase
Authors: Haode Huo, Jingjing He, Rui Kang, Xuefei Guan
Abstract:
This paper presents a study of Lamb wave damage diagnosis of composite delamination using instantaneous phase data. Numerical experiments are performed using the finite element method. Different sizes of delamination damages are modeled using finite element package ABAQUS. Lamb wave excitation and responses data are obtained using a pitch-catch configuration. Empirical mode decomposition is employed to extract the intrinsic mode functions (IMF). Hilbert–Huang Transform is applied to each of the resulting IMFs to obtain the instantaneous phase information. The baseline data for healthy plates are also generated using the same procedure. The size of delamination is correlated with the instantaneous phase change for damage diagnosis. It is observed that the unwrapped instantaneous phase of shows a consistent behavior with the increasing delamination size.Keywords: delamination, lamb wave, finite element method, EMD, instantaneous phase
Procedia PDF Downloads 3203365 Corporate Social Responsibility Practices and Financial Performance: The Case of French Unlisted SMEs
Authors: Zineb Abidi, Marc-Arthur Diaye
Abstract:
There exists a large empirical literature concerning the relationship between corporate social responsibility (CSR) and corporate financial performance. This literature, however, applies mainly to large corporations and/or listed firms. To the best of our knowledge, the question of whether meeting CSR requirements impacts the financial performance of small and medium-sized unlisted SMEs has not so far been analyzed. This paper aims to analyze, for the first time, the effect of CSR on the financial performance of SMEs. Using an original database including 5,257 French SMEs, we show that adopting CSR practices has a positive but weak effect on a firm’s financial performance. To develop this further, we analyzed CSR practices interactions assessing the best combination of CSR components that positively influence SME financial performance. Our results show that French SMEs benefit more from their pro-social behavior when they choose a combination of CSR components best adapted to their individual characteristics.Keywords: corporate social responsibility, financial performance, unlisted firms, SMEs
Procedia PDF Downloads 1723364 Household Survey on Food Behaviors and Nutrition Status in Suburb of Thailand
Authors: P. Chonsin, N. Neelapaichit, N. Piaseu
Abstract:
This household survey aimed to describe food behaviors and nutritional status of households in suburb nearby Bangkok, Thailand. Through convenience sampling, sample included 187 food providers from 125 households in three communities. Data were collected by structured interview and nutritional assessment. Results revealed that majority of the sample were female (68.4 %), aged between 18 to 91 years. The households selected raw foods concerning quality as the first priority (46.5%), cooking for their family members as 91.2%, using seasonings as 71.2%. The most favorite tastes were sweet (19.8%), salty (20.3%), and fatty (1.6%). Food related health problems were hypertension (40.1%), diabetes (26.7%), and dyslipidemia (19.3%). Approximately half of the overall samples (55.1%) and the sample with hypertension (84.5%) had excessive body mass index (BMI). Moreover, one-fourth of the sample with hypertension (25.3%) had salty food preference. Results suggest approaches to promote behavioral modification for sodium reduction particularly in food providers of households with hypertension and excessive BMI.Keywords: food behavior, nutrition status, household, suburb
Procedia PDF Downloads 3933363 Premarital Sex, HIV and Use of Condom among Youths in Nigeria
Authors: Okechukwu Odinaka Ajaegbu
Abstract:
In the recent past, discussing about sex among children and youths was frowned at by traditional norms and as such sexual discussions and behavior were approached with great respect. Things are actually falling apart with the increasing number of young people that engage in premarital sex. Due to lack of experience and sex education, many young people are becoming increasingly exposed to the risk of HIV infection. In the light of the above, this study discussed premarital sex, HIV and use of condom among youths in Nigeria. Data for this study came from 2013 Nigeria Demographic and Health Survey and other secondary data. The survey revealed that only 18.5 percent of young women that had sex in the 12 months preceding the survey used condom. Out of 3306 never-married sexually active men and women, 1728 representing 52 percent live in urban areas and 43 percent of them did not use condom during sexual intercourse in the 12 months preceding the survey. This study concludes that for there to be reduction in prevalence of HIV/AIDS among Nigerian youths, there is need for concerted effort to be made towards educating youths on the expedient of the use of condom during sexual intercourse.Keywords: condom, HIV, Nigeria, premarital sex, youths
Procedia PDF Downloads 2443362 A Review on Electrical Behavior of Different Substrates, Electrodes and Membranes in Microbial Fuel Cell
Authors: Bharat Mishra, Sanjay Kumar Awasthi, Raj Kumar Rajak
Abstract:
The devices, which convert the energy in the form of electricity from organic matters, are called microbial fuel cell (MFC). Recently, MFCs have been given a lot of attention due to their mild operating conditions, and various types of biodegradable substrates have been used in the form of fuel. Traditional MFCs were included in anode and cathode chambers, but there are single chamber MFCs. Microorganisms actively catabolize substrate, and bioelectricities are produced. In the field of power generation from non-conventional sources, apart from the benefits of this technique, it is still facing practical constraints such as low potential and power. In this study, most suitable, natural, low cost MFCs components are electrodes (anode and cathode), organic substrates, membranes and its design is selected on the basis of maximum potential (voltage) as an electrical parameter, which indicates a vital role of affecting factor in MFC for sustainable power production.Keywords: substrates, electrodes, membranes, MFCs design, voltage
Procedia PDF Downloads 3063361 Impact of the Xanthan Gum on Rheological Properties of Ceramic Slip
Authors: Souad Hassene Daouadji, Larbi Hammadi, Abdelkrim Hazzab
Abstract:
The slips intended for the manufacture of ceramics must have rheological properties well-defined in order to bring together the qualities required for the casting step (good fluidity for feeding the molds easily settles while generating a regular settling of the dough and for the dehydration phase of the dough in the mold a setting time relatively short is required to have a sufficient refinement which allows demolding both easy and fast). Many additives haveadded in slip of ceramic in order to improve their rheological properties. In this study, we investigated the impact of xanthan gumon rheological properties of ceramic Slip. The modified Cross model is used to fit the stationary flow curves of ceramic slip at different concentration of xanthan added. The thixotropic behavior studied of mixture ceramic slip-xanthan gumat constant temperature is analyzed by using a structural kinetic model (SKM) in order to account for time dependent effect.Keywords: ceramic slip, xanthan gum, modified cross model, thixotropy, viscosity
Procedia PDF Downloads 1913360 Printed Thai Character Recognition Using Particle Swarm Optimization Algorithm
Authors: Phawin Sangsuvan, Chutimet Srinilta
Abstract:
This Paper presents the applications of Particle Swarm Optimization (PSO) Method for Thai optical character recognition (OCR). OCR consists of the pre-processing, character recognition and post-processing. Before enter into recognition process. The Character must be “Prepped” by pre-processing process. The PSO is an optimization method that belongs to the swarm intelligence family based on the imitation of social behavior patterns of animals. Route of each particle is determined by an individual data among neighborhood particles. The interaction of the particles with neighbors is the advantage of Particle Swarm to determine the best solution. So PSO is interested by a lot of researchers in many difficult problems including character recognition. As the previous this research used a Projection Histogram to extract printed digits features and defined the simple Fitness Function for PSO. The results reveal that PSO gives 67.73% for testing dataset. So in the future there can be explored enhancement the better performance of PSO with improve the Fitness Function.Keywords: character recognition, histogram projection, particle swarm optimization, pattern recognition techniques
Procedia PDF Downloads 4773359 Analysis of Contact Width and Contact Stress of Three-Layer Corrugated Metal Gasket
Authors: I. Made Gatot Karohika, Shigeyuki Haruyama, Ken Kaminishi, Oke Oktavianty, Didik Nurhadiyanto
Abstract:
Contact width and contact stress are important parameters related to the leakage behavior of corrugated metal gasket. In this study, contact width and contact stress of three-layer corrugated metal gasket are investigated due to the modulus of elasticity and thickness of surface layer for 2 type gasket (0-MPa and 400-MPa mode). A finite element method was employed to develop simulation solution to analysis the effect of each parameter. The result indicated that lowering the modulus of elasticity ratio of surface layer will result in better contact width but the average contact stresses are smaller. When the modulus of elasticity ratio is held constant with thickness ratio increase, its contact width has an increscent trend otherwise the average contact stress has decreased trend.Keywords: contact width, contact stress, layer, metal gasket, corrugated, simulation
Procedia PDF Downloads 3183358 Deformability of the Rare Earth Metal Modified Metastable-β Alloy Ti-15Mo
Authors: F. Brunke, L. Waalkes, C. Siemers
Abstract:
Due to reduced stiffness, research on second generation titanium alloys for implant applications, like the metastable β-titanium alloy Ti-15Mo, become more and more important in the recent years. The machinability of these alloys is generally poor leading to problems during implant production and comparably large production costs. Therefore, in the present study, Ti 15Mo was alloyed with 0.8 wt.-% of the rare earth metals lanthanum (Ti-15Mo+0.8La) and neodymium (Ti-15Mo+0.8Nd) to improve its machinability. Their microstructure consisted of a titanium matrix and micrometer-size particles of the rare earth metals and two of their oxides. The particles stabilized the micro structure as grain growth was minimized. As especially the ductility might be affected by the precipitates, the behavior of Ti-15Mo+0.8La and Ti-15Mo+0.8Nd was investigated during static and dynamic deformation at elevated temperature to develop a processing route. The resulting mechanical properties (static strength and ductility) were similar in all investigated alloys.Keywords: Ti 15Mo, titanium alloys, rare earth metals, free machining alloy
Procedia PDF Downloads 3423357 Correlation to Predict the Effect of Particle Type on Axial Voidage Profile in Circulating Fluidized Beds
Authors: M. S. Khurram, S. A. Memon, S. Khan
Abstract:
Bed voidage behavior among different flow regimes for Geldart A, B, and D particles (fluid catalytic cracking catalyst (FCC), particle A and glass beads) of diameter range 57-872 μm, apparent density 1470-3092 kg/m3, and bulk density range 890-1773 kg/m3 were investigated in a gas-solid circulating fluidized bed of 0.1 m-i.d. and 2.56 m-height of plexi-glass. Effects of variables (gas velocity, particle properties, and static bed height) were analyzed on bed voidage. The axial voidage profile showed a typical trend along the riser: a dense bed at the lower part followed by a transition in the splash zone and a lean phase in the freeboard. Bed expansion and dense bed voidage increased with an increase of gas velocity as usual. From experimental results, a generalized model relationship based on inverse fluidization number for dense bed voidage from bubbling to fast fluidization regimes was presented.Keywords: axial voidage, circulating fluidized bed, splash zone, static bed
Procedia PDF Downloads 2863356 Diagnosis of Logistics Processes: Bibliometric Review and Analysis
Authors: S. F. Bayona, J. Nunez, D. Paez
Abstract:
The diagnostic processes have been consolidated as fundamental tools in the adequate knowledge of organizations and their processes. The diagnosis is related to the interpretation of the data, findings and the relevant information, to determine problems, causes, or the simple state and behavior of a process, without including a solution to the problems detected. The objective of this work is to identify the necessary stages to diagnose the logistic processes in a metalworking company, from the literary revision of different disciplines. A total of 62 articles were chosen to identify, through bibliometric analysis, the most cited articles, as well as the most frequent authors and journals. The results allowed to identify the two fundamental stages in the diagnostic process: a primary phase (general) based on the logical subjectivity of the knowledge of the person who evaluates, and the secondary phase (specific), related to the interpretation of the results, findings or data. Also, two phases were identified, one related to the definition of the scope of the actions to be developed and the other, as an initial description of what was observed in the process.Keywords: business, diagnostic, management, process
Procedia PDF Downloads 1573355 Study of Bored Pile Retaining Wall Using Physical Modeling
Authors: Amin Eslami, Jafar Bolouri Bazaz
Abstract:
Excavation and retaining walls are of challenging issues in civil engineering. In this study, the behavior of one the important type of supporting systems called Contiguous Bored Pile (CBP) retaining wall is investigated using a physical model. Besides, a comparison is made between two modes of free end piles(soft bed) and fixed end piles (stiff bed). Also a back calculation of effective length (the real free length of pile) is done by measuring lateral deflection of piles in different stages of excavation in both a forementioned cases. Based on observed results, for the fixed end mode, the effective length to free length ratio (Leff/L0) is equal to unity in initial stages of excavation and less than 1 in its final stages in a decreasing manner. While this ratio for free end mode, remains constant during all stages of excavation and is always less than unity.Keywords: contiguous bored pile wall, effective length, fixed end, free end, free length
Procedia PDF Downloads 3993354 Effect of Irradiation on Nano-Indentation Properties and Microstructure of X-750 Ni-Based Superalloy
Authors: Pooyan Changizian, Zhongwen Yao
Abstract:
The purpose of current study is to make an excellent correlation between mechanical properties and microstructures of ion irradiated X-750 Ni-based superalloy. Towards this end, two different irradiation procedures were carried out, including single Ni ion irradiation and pre-helium implantation with subsequent Ni ion irradiation. Nano-indentation technique was employed to evaluate the mechanical properties of irradiated material. The nano-hardness measurements depict highly different results for two irradiation procedures. Single ion irradiated X-750 shows softening behavior; however, pre-helium implanted specimens present significant hardening compared to the un-irradiated material. Cross-section TEM examination demonstrates that softening is attributed to the γ׳-precipitate instability (disordering/dissolution) which overcomes the hardening effect of irradiation-induced defects. In contrast, the presence of cavities or helium bubbles is probably the main cause for irradiation-induced hardening of helium implanted samples.Keywords: Inconel X-750, nanoindentation, helium bubbles, defects
Procedia PDF Downloads 2223353 Typology of Gaming Tourists Based on the Perception of Destination Image
Authors: Mi Ju Choi
Abstract:
This study investigated the perception of gaming tourists toward Macau and developed a typology of gaming tourists. The 1,497 responses from tourists in Macau were collected through convenience sampling method. The dimensions of multi-culture, convenience, economy, gaming, and unsafety, were subsequently extracted as the factors of perception of gaming tourists in Macau. Cluster analysis was performed using the delineated factors (perception of tourists on Macau). Four heterogonous groups were generated, namely, gaming lovers (n = 467, 31.2%), exotic lovers (n = 509, 34.0%), reasonable budget seekers (n = 269, 18.0%), and convenience seekers (n = 252, 16.8%). Further analysis was performed to investigate any difference in gaming behavior and tourist activities. The findings are expected to contribute to the efforts of destination marketing organizations (DMOs) in establishing effective business strategies, provide a profile of gaming tourists in certain market segments, and assist DMOs and casino managers in establishing more effective marketing strategies for target markets.Keywords: destination image, gaming tourists, Macau, segmentation
Procedia PDF Downloads 3013352 Perception of Consumer Behavior on Mobile Banking Offered by the National and Multinational Banks in UAE with Special Reference to Emirates NBD and Citibank
Authors: Aarohi Surya
Abstract:
The number of mobile banking users continues to climb across the world due to its increasing popularity, and UAE is no exception. This type of banking is part of the core strategy of most of the financial institutions that allows its customers to conduct a range of financial transactions through mobile apps to cash in the high demand from the bankers. This study aims at evaluating service quality of online banking in Dubai, one of the swiftly growing cities of Middle East. The paper mainly compares online banking services of Multinational bank and National Bank with special reference to Citibank and Emirates NBD. A structured questionnaire survey is conducted among various target groups. The research has been focused on mainly 4 significant areas of online banking, i.e. Privacy, Responsiveness, Reliability, and Efficiency of customer data. Information was analyzed statistically on SPSS to investigate the service quality of e-banking.Keywords: customer satisfaction, service quality, responsiveness, online banking
Procedia PDF Downloads 2703351 Incorporation of Foundry Sand in Asphalt Pavement
Authors: L. P. Nascimento, M. Soares, N. Valério, A. Ribeiro, J. R. M. Oliveira, J. Araújo, C. Vilarinho, J. Carvalho
Abstract:
With the growing need to save natural resources and value waste that was previously worthless, waste recycling becomes imperative. Thus, with the techno-scientific growth and in the perspective of sustainability, it is observed that waste has the potential to replace significant percentages of materials considered “virgin”. An example is the replacement of crushed aggregates with foundry sand. In this work, a mix design study of two asphalt mixes, a base mix (AC 20) and a surface mix (AC14) was carried out to evaluate the maximum amount of foundry sand residue that could be used. Water sensitivity tests were performed to evaluate the mechanical behavior of these mixtures. For the superficial mixture with foundry sand (AC14FS), the maximum of sand used was 5%, with satisfactory results of sensitivity to water. In the base mixture with sand (AC20FS), the maximum of sand used was 12%, which had less satisfactory results. However, from an environmental point of view, the re-incorporation of this residue in the pavement is beneficial because it prevents it from being deposited in landfills.Keywords: foundry sand, hot mix asphalt, industrial waste, waste valorization, sustainability
Procedia PDF Downloads 1113350 Autism Awareness Among School Students and the Violent Reaction of the Autist Toward Society in Egypt
Authors: Naglaa Baskhroun Thabet Wasef
Abstract:
Specific education services for students with Autism remains in its early developmental stages in Egypt. In spite of many more children with autism are attending schools since The Egyptian government introduced the Education Provision for Students with Disabilities Act in 2010, the services students with autism and their families receive are generally not enough. This pointed study used Attitude and Reaction to Teach Students with Autism Scale to investigate 50 primary school teachers’ attitude and reaction to teach students with autism in the general education classroom. Statistical analysis of the data found that student behavior was the most noticeable factor in building teachers’ wrong attitudes students with autism. The minority of teachers also indicated that their service education did not prepare them to meet the learning needs of children with autism in special, those who are non-vocal. The study is descriptive and provides direction for increasing teacher awareness for inclusivity in Egypt.Keywords: attitude, autism, teachers, sports activates, movement skills, motor skills, autism attitude
Procedia PDF Downloads 643349 Corrosion Behavior of Steels in Molten Salt Reactors
Authors: Jana Rejková, Marie Kudrnová
Abstract:
This paper deals with the research of materials for one of the types of reactors IV. generation - reactor with molten salts. One of the advantages of molten salts applied as a coolant in reactors is the ability to operate at relatively low pressures, as opposed to cooling with water or gases. Compared to liquid metal cooling, which also allows lower operating pressures, salt melts are less prone to chemical reactions. The service life of the construction materials used is limited by the operating temperatures of the reactor and the content of impurities in the salts. For the research of corrosion resistance, an experimental device was designed and assembled, enabling exposure at high temperatures without access to oxygen in a flowing atmosphere of inert gas. Nickel alloys Inconel 601, 617, and 625 were tested in a mixture of chloride salts LiCl – KCl (58,2 - 41,8 wt. %). The experiment showed high resistance of the materials used and based on the results and XPS analysis, other construction materials were proposed for the experiments.Keywords: molten salt, corrosion, nuclear reactor, nickel alloy
Procedia PDF Downloads 1653348 Effect of Realistic Lubricant Properties on Thermal Electrohydrodynamic Lubrication Behavior in Circular Contacts
Authors: Puneet Katyal, Punit Kumar
Abstract:
A great deal of efforts has been done in the field of thermal effects in electrohydrodynamic lubrication (TEHL) during the last five decades. The focus was primarily on the development of an efficient numerical scheme to deal with the computational challenges involved in the solution of TEHL model; however, some important aspects related to the accurate description of lubricant properties such as viscosity, rheology and thermal conductivity in EHL point contact analysis remain largely neglected. A few studies available in this regard are based upon highly complex mathematical models difficult to formulate and execute. Using a simplified thermal EHL model for point contacts, this work sheds some light on the importance of accurate characterization of the lubricant properties and demonstrates that the computed TEHL characteristics are highly sensitive to lubricant properties. It also emphasizes the use of appropriate mathematical models with experimentally determined parameters to account for correct lubricant behaviour.Keywords: TEHL, shear thinning, rheology, conductivity
Procedia PDF Downloads 2003347 Discrete Crack Modeling of Side Face FRP-Strengthened Concrete Beam
Authors: Shahriar Shahbazpanahi, Mohammad Hemen Jannaty, Alaleh Kamgar
Abstract:
Shear strengthening can be carried out in concrete structures by external fibre reinforced polymer (FRP). In the present investigation, a new fracture mechanics model is developed to model side face of strengthened concrete beam by external FRP. Discrete crack is simulated by a spring element with softening behavior ahead of the crack tip to model the cohesive zone in concrete. A truss element is used, parallel to the spring element, to simulate the energy dissipation rate by the FRP. The strain energy release rate is calculated directly by using a virtual crack closure technique and then, the crack propagation criterion is presented. The results are found acceptable when compared to previous experimental results and ABAQUS software data. It is observed that the length of the fracture process zone (FPZ) increases with the application of FRP in side face at the same load in comparison with that of the control beam.Keywords: FPZ, fracture, FRP, shear
Procedia PDF Downloads 5343346 Analysis of High-Velocity Impacts on Concrete
Authors: Conceição, J. F. M., Rebelo H., Corneliu C., Pereira L.
Abstract:
This research analyses the response of two distinct types of concrete blocks, each possessing an approximate unconfined compressive strength of 30MPa, when exposed to high-velocity impacts produced by an Explosively Formed Penetrator (EFP) traveling at an initial velocity of 1200 m/s. Given the scarcity of studies exploring high-velocity impacts on concrete, the primary aim of this research is to scrutinize how concrete behaves under high-speed impacts, ultimately contributing valuable insights to the development of protective structures. To achieve this objective, a comprehensive numerical analysis was carried out in LS-DYNA to delve into the fracture mechanisms inherent in concrete under such extreme conditions. Subsequently, the obtained numerical outcomes were compared and validated through eight experimental field tests. The methodology employed involved a robust combination of numerical simulations and real-world experiments, ensuring a comprehensive understanding of concrete behavior in scenarios involving rapid, high-energy impacts.Keywords: high-velocity, impact, numerical analysis, experimental tests, concrete
Procedia PDF Downloads 863345 The Examination of Withdrawn Behavior in Chinese Adolescents
Authors: Zhidong Zhang, Zhi-Chao Zhang, Georgiana Duarte
Abstract:
This study examined withdrawn syndromes of Chinese school children in northeast China in Northeast China. Specifically, the study examined withdrawn behaviors and the relationship to anxious syndromes and 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 school children’s withdrawn 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 withdrawn problem. Specifically, age, grade, sports activities and hobbies had a relationship with the anxious/depressed variable. Further withdrawn syndromes and anxious problem indicate a significant correlation.Keywords: anxious/depressed problem, ASEBA, CBCL, withdrawn syndromes
Procedia PDF Downloads 2973344 Influence of Percentage and Melting Temperature of Phase Change Material on the Thermal Behavior of a Hollow-Brick
Authors: Zakaria Aketouane, Mustapha Malha, Abdellah Bah, Omar Ansari, Mohamed Asbik
Abstract:
The present paper deals with the thermal performance of a hollow-brick filled with Phase Change Material (PCM). The main objective is to study the effect of percentage and melting temperature of the PCM on the thermal inertia and internal surface temperature of the hollow-brick. A numerical model based on the heat transfer equation and the apparent heat capacity method has been validated using experimental study from the literature. The results show that increasing the percentage of the PCM has a significant effect on time lag and decrement factor that define the thermal inertia; the internal temperature is reduced by 1.36°C to 5.39°C for a percentage from 11% to 71% in comparison to a brick without PCM. In addition, an appropriate melting temperature of 37°C has been deduced for the horizontal wall orientation in Rabat in comparison to 27°C and 47°C.Keywords: appropriate melting temperature, decrement factor, phase change material, thermal inertia, time lag
Procedia PDF Downloads 2353343 Effect of Impact Load on the Bond between Steel and CFRP Laminate
Authors: Alaa Al-Mosawe, Riadh Al-Mahaidi
Abstract:
Carbon fiber reinforced polymers have been wildly used to strengthen steel structural elements. Those structural elements are normally subjected to static, dynamic, fatigue loadings during their life time. CFRP laminate is one of the common methods to strengthen these structures under the subjected loads. A number of researches have been focused on the bond characteristics of CFRP sheets to steel members under static, dynamic and fatigue loadings. There is a lack in understanding the behavior of the CFRP laminates under impact loading. This paper is showing the effect of high load rate on this bond. CFRP laminate CFK 150/2000 was used to strengthen steel joint by using Araldite 420 epoxy. The results showed that applying high load rate has a significant effect on the bond strength while a little influence on the effective bond length.Keywords: adhesively bonded joints, bond strength, CFRP laminate, impact tensile loading
Procedia PDF Downloads 3603342 Behavior of Steel Moment Frames Subjected to Impact Load
Authors: Hyungoo Kang, Minsung Kim, Jinkoo Kim
Abstract:
This study investigates the performance of a 2D and 3D steel moment frame subjected to vehicle collision at a first story column using LS-DYNA. The finite element models of vehicles provided by the National Crash Analysis Center (NCAC) are used for numerical analysis. Nonlinear dynamic time history analysis of the 2D and 3D model structures are carried out based on the arbitrary column removal scenario, and the vertical displacement of the damaged structures are compared with that obtained from collision analysis. The analysis results show that the model structure remains stable when the speed of the vehicle is 40km/h. However, at the speed of 80 and 120km/h both the 2D and 3D structures collapse by progressive collapse. The vertical displacement of the damaged joint obtained from collision analysis is significantly larger than the displacement computed based on the arbitrary column removal scenario.Keywords: vehicle collision, progressive collapse, FEM, LS-DYNA
Procedia PDF Downloads 3423341 A Curricular Approach to Organizational Mentoring Programs: The Integrated Mentoring Curriculum Model
Authors: Christopher Webb
Abstract:
This work presents a new model of mentoring in an organizational environment and has important implications for both practice and research, the model frames the organizational environment as organizational curriculum, which includes the elements that affect learning within the organization. This includes the organizational structure and culture, roles within the organization, and accessibility of knowledge. The program curriculum includes the elements of the mentoring program, including materials, training, and scheduled events for the program participants. The term dyadic curriculum is coined in this work. The dyadic curriculum describes the participation, behavior, and identities of the pairs participating in mentorships. This also includes the identity work of the participants and their views of each other. Much of this curriculum is unprescribed and is unique within each dyad. It describes how participants mediate the elements of organizational and program curricula. These three curricula interact and affect each other in predictable ways. A detailed example of a mentoring program framed in this model is provided.Keywords: curriculum, mentoring, organizational learning and development, social learning
Procedia PDF Downloads 2023340 Mechanical Properties of CNT Reinforced Composite Using Berkovich Nanoindentation Analysis
Authors: Khondaker Sakil Ahmed, Ang Kok Keng, Shah Md Muniruzzaman
Abstract:
Spherical and Berkovich indentation tests are carried out numerically using finite element method for uniformly dispersed Carbon Nanotube (CNT) in the polymer matrix in which perfectly bonded CNT/matrix interface is considered. The Large strain elasto-plastic analysis is performed to investigate the actual scenario of nanoindentation test. This study investigates how the addition of CNT in polymer matrix influences the mechanical properties like hardness, elastic modulus of the nanocomposite. Since the wall thickness to radius ratio (t/r) is significantly small for SWCNT there is a huge possibility of lateral buckling which is a function of the location of indentation tip as well as the mechanical properties of matrix. Separate finite element models are constructed to compare the result with Berkovich indentation. This study also investigates the buckling behavior of different nanotube in a different polymer matrix.Keywords: carbon nanotube, elasto-plastic, finite element model, nano-indentation
Procedia PDF Downloads 3893339 Biaxial Buckling of Single Layer Graphene Sheet Based on Nonlocal Plate Model and Molecular Dynamics Simulation
Authors: R. Pilafkan, M. Kaffash Irzarahimi, S. F. Asbaghian Namin
Abstract:
The biaxial buckling behavior of single-layered graphene sheets (SLGSs) is studied in the present work. To consider the size-effects in the analysis, Eringen’s nonlocal elasticity equations are incorporated into classical plate theory (CLPT). A Generalized Differential Quadrature Method (GDQM) approach is utilized and numerical solutions for the critical buckling loads are obtained. Then, molecular dynamics (MD) simulations are performed for a series of zigzag SLGSs with different side-lengths and with various boundary conditions, the results of which are matched with those obtained by the nonlocal plate model to numerical the appropriate values of nonlocal parameter relevant to each type of boundary conditions.Keywords: biaxial buckling, single-layered graphene sheets, nonlocal elasticity, molecular dynamics simulation, classical plate theory
Procedia PDF Downloads 2783338 The Portrayal of Journalists in K-dramas Leaves an Impression on Viewers
Authors: Susan Grantham, Emily S. Kinsky
Abstract:
As the popularity of K-drama viewership increases, the depiction of journalists’ news gathering and distribution behavior in these series can have an impact on viewers’ perceptions of journalism practices in Korea. Studies have shown that viewers are impacted both by their impressions of actual journalists delivering news, as well as by fictional portrayals of journalists they have seen. As mistrust in the media grows internationally, it is important to understand how journalists are viewed. K-dramas are an increasingly popular export and consumed across the globe. In 2021 Netflix had 74 million subscribers in the US/Canadian market, about 36% of its overall subscriber base, with an in- crease of about 16 million new subscribers during the pandemic. A Statista November 2023 survey found that K-dramas are moderately (27%) or very popular (41%). While Hallyu has grown increasingly in the past decade, between 2019 and 2021, viewership numbers for TV series produced in South Korea went up a staggering 200% in the U.S. Additionally, a 2023 KOCCA report about K-drama viewership in the U.S. found that, within the past year, male viewership became nearly equal to female viewership. This study evaluated how viewers perceive journalists and journalistic practices in South Korea as portrayed in eight K-drama series. Six in-depth interviews and two focus groups were conducted to evaluate viewer perceptions of journalism practices as portrayed in K-dramas. This study builds upon two previous research projects: a content analysis of the same eight K-dramas featuring journalists in a primary role and whose journalistic work is pivotal to the plot, followed by subsequent in-depth interviews with South Korean journalists. The K-dramas in the sample featured both print and broadcast journalists. Using clips from these K-drama series that featured journalistic practices, as well as pressure faced by journalists, participants were be asked a series of questions about their impressions of journalists and journalism in South Korea and how realistic they perceived these portrayals to be. The participants were comprised of viewers who frequently watched K-dramas and occasionally/seldom watched K-dramas. The initial findings show that regardless of how frequently the participants watched K-dramas, they indicated that the presentation of the journalists seemed pretty realistic, and that the journalists behaved ethically. Participants felt their portrayal was relatable to their impression of how journalists behaved in the United States. This was also true in terms of the internal pressure shown in the clips toward journalists that featured behavior by the journalists’ supervisors focused on supporting the media company’s political and business positions. The amount of negative feedback toward the journalists from the general public, as shown in the clips, seemed less realistic to the participants. The idea of ‘fake news’ as a function of the news consumer’s own personal beliefs, versus actual misinformation, resonated with the participants. Additional research is being conducted. Because Korea is an important source of news and information in East Asia, it is important to understand the potential perceptions of consumers and how they view journalistic practices in Korea.Keywords: ethical journalism, K-drama, Korean journalists, viewer perceptions
Procedia PDF Downloads 20